Commit Graph

1322 Commits

Author SHA1 Message Date
Vladimir Sementsov-Ogievskiy
6e9b225f73 block: introduce aio task pool
Common interface for aio task loops. To be used for improving
performance of synchronous io loops in qcow2, block-stream,
copy-on-read, and may be other places.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190916175324.18478-3-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-10-10 10:56:17 +02:00
Eric Blake
61bc846d8c nbd: Grab aio context lock in more places
When iothreads are in use, the failure to grab the aio context results
in an assertion failure when trying to unlock things during blk_unref,
when trying to unlock a mutex that was not locked.  In short, all
calls to nbd_export_put need to done while within the correct aio
context.  But since nbd_export_put can recursively reach itself via
nbd_export_close, and recursively grabbing the context would deadlock,
we can't do the context grab directly in those functions, but must do
so in their callers.

Hoist the use of the correct aio_context from nbd_export_new() to its
caller qmp_nbd_server_add().  Then tweak qmp_nbd_server_remove(),
nbd_eject_notifier(), and nbd_esport_close_all() to grab the right
context, so that all callers during qemu now own the context before
nbd_export_put() can call blk_unref().

Remaining uses in qemu-nbd don't matter (since that use case does not
support iothreads).

Suggested-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20190917023917.32226-1-eblake@redhat.com>
Reviewed-by: Sergio Lopez <slp@redhat.com>
2019-09-24 07:30:19 -05:00
Nir Soffer
8972571509 block: Remove unused masks
Replace confusing usage:

    ~BDRV_SECTOR_MASK

With more clear:

    (BDRV_SECTOR_SIZE - 1)

Remove BDRV_SECTOR_MASK and the unused BDRV_BLOCK_OFFSET_MASK which was
it's last user.

Signed-off-by: Nir Soffer <nsoffer@redhat.com>
Message-id: 20190827185913.27427-3-nsoffer@redhat.com
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-09-16 14:48:30 +02:00
Vladimir Sementsov-Ogievskiy
bb0c940993 job: drop job_drain
In job_finish_sync job_enter should be enough for a job to make some
progress and draining is a wrong tool for it. So use job_enter directly
here and drop job_drain with all related staff not used more.

Suggested-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Tested-by: John Snow <jsnow@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-09-10 08:58:43 +02:00
Eric Blake
0a4795455c nbd: Prepare for NBD_CMD_FLAG_FAST_ZERO
Commit fe0480d6 and friends added BDRV_REQ_NO_FALLBACK as a way to
avoid wasting time on a preliminary write-zero request that will later
be rewritten by actual data, if it is known that the write-zero
request will use a slow fallback; but in doing so, could not optimize
for NBD.  The NBD specification is now considering an extension that
will allow passing on those semantics; this patch updates the new
protocol bits and 'qemu-nbd --list' output to recognize the bit, as
well as the new errno value possible when using the new flag; while
upcoming patches will improve the client to use the feature when
present, and the server to advertise support for it.

The NBD spec recommends (but not requires) that ENOTSUP be avoided for
all but failures of a fast zero (the only time it is mandatory to
avoid an ENOTSUP failure is when fast zero is supported but not
requested during write zeroes; the questionable use is for ENOTSUP to
other actions like a normal write request).  However, clients that get
an unexpected ENOTSUP will either already be treating it the same as
EINVAL, or may appreciate the extra bit of information.  We were
equally loose for returning EOVERFLOW in more situations than
recommended by the spec, so if it turns out to be a problem in
practice, a later patch can tighten handling for both error codes.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20190823143726.27062-3-eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
[eblake: tweak commit message, also handle EOPNOTSUPP]
2019-09-05 16:03:13 -05:00
Eric Blake
dbb38caac5 nbd: Improve per-export flag handling in server
When creating a read-only image, we are still advertising support for
TRIM and WRITE_ZEROES to the client, even though the client should not
be issuing those commands.  But seeing this requires looking across
multiple functions:

All callers to nbd_export_new() passed a single flag based solely on
whether the export allows writes.  Later, we then pass a constant set
of flags to nbd_negotiate_options() (namely, the set of flags which we
always support, at least for writable images), which is then further
dynamically modified with NBD_FLAG_SEND_DF based on client requests
for structured options.  Finally, when processing NBD_OPT_EXPORT_NAME
or NBD_OPT_EXPORT_GO we bitwise-or the original caller's flag with the
runtime set of flags we've built up over several functions.

Let's refactor things to instead compute a baseline of flags as soon
as possible which gets shared between multiple clients, in
nbd_export_new(), and changing the signature for the callers to pass
in a simpler bool rather than having to figure out flags.  We can then
get rid of the 'myflags' parameter to various functions, and instead
refer to client for everything we need (we still have to perform a
bitwise-OR for NBD_FLAG_SEND_DF during NBD_OPT_EXPORT_NAME and
NBD_OPT_EXPORT_GO, but it's easier to see what is being computed).
This lets us quit advertising senseless flags for read-only images, as
well as making the next patch for exposing FAST_ZERO support easier to
write.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20190823143726.27062-2-eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
[eblake: improve commit message, update iotest 223]
2019-09-05 16:02:54 -05:00
Eric Blake
61cc872456 nbd: Advertise multi-conn for shared read-only connections
The NBD specification defines NBD_FLAG_CAN_MULTI_CONN, which can be
advertised when the server promises cache consistency between
simultaneous clients (basically, rules that determine what FUA and
flush from one client are able to guarantee for reads from another
client).  When we don't permit simultaneous clients (such as qemu-nbd
without -e), the bit makes no sense; and for writable images, we
probably have a lot more work before we can declare that actions from
one client are cache-consistent with actions from another.  But for
read-only images, where flush isn't changing any data, we might as
well advertise multi-conn support.  What's more, advertisement of the
bit makes it easier for clients to determine if 'qemu-nbd -e' was in
use, where a second connection will succeed rather than hang until the
first client goes away.

This patch affects qemu as server in advertising the bit.  We may want
to consider patches to qemu as client to attempt parallel connections
for higher throughput by spreading the load over those connections
when a server advertises multi-conn, but for now sticking to one
connection per nbd:// BDS is okay.

See also: https://bugzilla.redhat.com/1708300
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20190815185024.7010-1-eblake@redhat.com>
[eblake: tweak blockdev-nbd.c to not request shared when writable,
fix iotest 233]
Reviewed-by: John Snow <jsnow@redhat.com>
2019-09-05 15:51:55 -05:00
Vladimir Sementsov-Ogievskiy
1acc3466a2 block/io: introduce bdrv_co_p{read, write}v_part
Introduce extended variants of bdrv_co_preadv and bdrv_co_pwritev
with qiov_offset parameter.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20190604161514.262241-10-vsementsov@virtuozzo.com
Message-Id: <20190604161514.262241-10-vsementsov@virtuozzo.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-08-27 14:58:42 +01:00
Vladimir Sementsov-Ogievskiy
ac850bf099 block: define .*_part io handlers in BlockDriver
Add handlers supporting qiov_offset parameter:
    bdrv_co_preadv_part
    bdrv_co_pwritev_part
    bdrv_co_pwritev_compressed_part
This is used to reduce need of defining local_qiovs and hd_qiovs in all
corners of block layer code. The following patches will increase usage
of this new API part by part.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20190604161514.262241-5-vsementsov@virtuozzo.com
Message-Id: <20190604161514.262241-5-vsementsov@virtuozzo.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-08-27 14:58:42 +01:00
Max Reitz
ceaca56fee block: Add bdrv_has_zero_init_truncate()
No .bdrv_has_zero_init() implementation returns 1 if growing the file
would add non-zero areas (at least with PREALLOC_MODE_OFF), so using it
in lieu of this new function was always safe.

But on the other hand, it is possible that growing an image that is not
zero-initialized would still add a zero-initialized area, like when
using nonpreallocating truncation on a preallocated image.  For callers
that care only about truncation, not about creation with potential
preallocation, this new function is useful.

Alternatively, we could have added a PreallocMode parameter to
bdrv_has_zero_init().  But the only user would have been qemu-img
convert, which does not have a plain PreallocMode value right now -- it
would have to parse the creation option to obtain it.  Therefore, the
simpler solution is to let bdrv_has_zero_init() inquire the
preallocation status and add the new bdrv_has_zero_init_truncate() that
presupposes PREALLOC_MODE_OFF.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190724171239.8764-4-mreitz@redhat.com
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-08-19 17:13:26 +02:00
Max Reitz
cdf3bc934a mirror: Fix bdrv_has_zero_init() use
bdrv_has_zero_init() only has meaning for newly created images or image
areas.  If the mirror job itself did not create the image, it cannot
rely on bdrv_has_zero_init()'s result to carry any meaning.

This is the case for drive-mirror with mode=existing and always for
blockdev-mirror.

Note that we only have to zero-initialize the target with sync=full,
because other modes actually do not promise that the target will contain
the same data as the source after the job -- sync=top only promises to
copy anything allocated in the top layer, and sync=none will only copy
new I/O.  (Which is how mirror has always handled it.)

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190724171239.8764-3-mreitz@redhat.com
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-08-19 17:13:26 +02:00
John Snow
c4e4b0fa59 qapi: implement block-dirty-bitmap-remove transaction action
It is used to do transactional movement of the bitmap (which is
possible in conjunction with merge command). Transactional bitmap
movement is needed in scenarios with external snapshot, when we don't
want to leave copy of the bitmap in the base image.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190708220502.12977-3-jsnow@redhat.com
[Edited "since" version to 4.2 --js]
Signed-off-by: John Snow <jsnow@redhat.com>
2019-08-16 16:28:03 -04:00
John Snow
28636b8211 block/dirty-bitmap: add bdrv_dirty_bitmap_get
Add a public interface for get. While we're at it,
rename "bdrv_get_dirty_bitmap_locked" to "bdrv_dirty_bitmap_get_locked".

(There are more functions to rename to the bdrv_dirty_bitmap_VERB form,
but they will wait until the conclusion of this series.)

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190709232550.10724-11-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2019-08-16 16:28:02 -04:00
John Snow
b7661ca5d8 block/dirty-bitmap: add bdrv_dirty_bitmap_merge_internal
I'm surprised it didn't come up sooner, but sometimes we have a +busy
bitmap as a source. This is dangerous from the QMP API, but if we are
the owner that marked the bitmap busy, it's safe to merge it using it as
a read only source.

It is not safe in the general case to allow users to read from in-use
bitmaps, so create an internal variant that foregoes the safety
checking.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190709232550.10724-10-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2019-08-16 16:28:02 -04:00
John Snow
c8b5650178 block/backup: Add mirror sync mode 'bitmap'
We don't need or want a new sync mode for simple differences in
semantics.  Create a new mode simply named "BITMAP" that is designed to
make use of the new Bitmap Sync Mode field.

Because the only bitmap sync mode is 'on-success', this adds no new
functionality to the backup job (yet). The old incremental backup mode
is maintained as a syntactic sugar for sync=bitmap, mode=on-success.

Add all of the plumbing necessary to support this new instruction.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190709232550.10724-6-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2019-08-16 16:28:02 -04:00
Peter Maydell
c6a2225a5a nbd patches for 2019-08-15
- Addition of InetSocketAddress keep-alive
 - Addition of BDRV_REQ_PREFETCH for more efficient copy-on-read
 - Initial refactoring in preparation of NBD reconnect
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Merge remote-tracking branch 'remotes/ericb/tags/pull-nbd-2019-08-15' into staging

nbd patches for 2019-08-15

- Addition of InetSocketAddress keep-alive
- Addition of BDRV_REQ_PREFETCH for more efficient copy-on-read
- Initial refactoring in preparation of NBD reconnect

# gpg: Signature made Thu 15 Aug 2019 19:28:41 BST
# gpg:                using RSA key A7A16B4A2527436A
# gpg: Good signature from "Eric Blake <eblake@redhat.com>" [full]
# gpg:                 aka "Eric Blake (Free Software Programmer) <ebb9@byu.net>" [full]
# gpg:                 aka "[jpeg image of size 6874]" [full]
# Primary key fingerprint: 71C2 CC22 B1C4 6029 27D2  F3AA A7A1 6B4A 2527 436A

* remotes/ericb/tags/pull-nbd-2019-08-15:
  block/nbd: refactor nbd connection parameters
  block/nbd: add cmdline and qapi parameter reconnect-delay
  block/nbd: move from quit to state
  block/nbd: use non-blocking io channel for nbd negotiation
  block/nbd: split connection_co start out of nbd_client_connect
  nbd: improve CMD_CACHE: use BDRV_REQ_PREFETCH
  block/stream: use BDRV_REQ_PREFETCH
  block: implement BDRV_REQ_PREFETCH
  qapi: Add InetSocketAddress member keep-alive

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-08-16 15:53:37 +01:00
Markus Armbruster
db72581598 Include qemu/main-loop.h less
In my "build everything" tree, changing qemu/main-loop.h triggers a
recompile of some 5600 out of 6600 objects (not counting tests and
objects that don't depend on qemu/osdep.h).  It includes block/aio.h,
which in turn includes qemu/event_notifier.h, qemu/notify.h,
qemu/processor.h, qemu/qsp.h, qemu/queue.h, qemu/thread-posix.h,
qemu/thread.h, qemu/timer.h, and a few more.

Include qemu/main-loop.h only where it's needed.  Touching it now
recompiles only some 1700 objects.  For block/aio.h and
qemu/event_notifier.h, these numbers drop from 5600 to 2800.  For the
others, they shrink only slightly.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190812052359.30071-21-armbru@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
2019-08-16 13:31:52 +02:00
Markus Armbruster
2ae16a6aa4 Include generated QAPI headers less
Some of the generated qapi-types-MODULE.h are included all over the
place.  Changing a QAPI type can trigger massive recompiling.  Top
scorers recompile more than 1000 out of some 6600 objects (not
counting tests and objects that don't depend on qemu/osdep.h):

    6300 qapi/qapi-builtin-types.h
    5700 qapi/qapi-types-run-state.h
    3900 qapi/qapi-types-common.h
    3300 qapi/qapi-types-sockets.h
    3000 qapi/qapi-types-misc.h
    3000 qapi/qapi-types-crypto.h
    3000 qapi/qapi-types-job.h
    3000 qapi/qapi-types-block-core.h
    2800 qapi/qapi-types-block.h
    1300 qapi/qapi-types-net.h

Clean up headers to include generated QAPI headers only where needed.
Impact is negligible except for hw/qdev-properties.h.

This header includes qapi/qapi-types-block.h and
qapi/qapi-types-misc.h.  They are used only in expansions of property
definition macros such as DEFINE_PROP_BLOCKDEV_ON_ERROR() and
DEFINE_PROP_OFF_AUTO().  Moving their inclusion from
hw/qdev-properties.h to the users of these macros avoids pointless
recompiles.  This is how other property definition macros, such as
DEFINE_PROP_NETDEV(), already work.

Improves things for some of the top scorers:

    3600 qapi/qapi-types-common.h
    2800 qapi/qapi-types-sockets.h
     900 qapi/qapi-types-misc.h
    2200 qapi/qapi-types-crypto.h
    2100 qapi/qapi-types-job.h
    2100 qapi/qapi-types-block-core.h
     270 qapi/qapi-types-block.h

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20190812052359.30071-3-armbru@redhat.com>
2019-08-16 13:31:51 +02:00
Markus Armbruster
ec150c7e09 include: Make headers more self-contained
Back in 2016, we discussed[1] rules for headers, and these were
generally liked:

1. Have a carefully curated header that's included everywhere first.  We
   got that already thanks to Peter: osdep.h.

2. Headers should normally include everything they need beyond osdep.h.
   If exceptions are needed for some reason, they must be documented in
   the header.  If all that's needed from a header is typedefs, put
   those into qemu/typedefs.h instead of including the header.

3. Cyclic inclusion is forbidden.

This patch gets include/ closer to obeying 2.

It's actually extracted from my "[RFC] Baby steps towards saner
headers" series[2], which demonstrates a possible path towards
checking 2 automatically.  It passes the RFC test there.

[1] Message-ID: <87h9g8j57d.fsf@blackfin.pond.sub.org>
    https://lists.nongnu.org/archive/html/qemu-devel/2016-03/msg03345.html
[2] Message-Id: <20190711122827.18970-1-armbru@redhat.com>
    https://lists.nongnu.org/archive/html/qemu-devel/2019-07/msg02715.html

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20190812052359.30071-2-armbru@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
2019-08-16 13:31:51 +02:00
Vladimir Sementsov-Ogievskiy
a8e2bb6a76 block/nbd: use non-blocking io channel for nbd negotiation
No reason to use blocking channel for negotiation and we'll benefit in
further reconnect feature, as qio_channel reads and writes will do
qemu_coroutine_yield while waiting for io completion.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20190618114328.55249-3-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2019-08-15 13:22:14 -05:00
Vladimir Sementsov-Ogievskiy
3299e5ecf7 block: implement BDRV_REQ_PREFETCH
Do effective copy-on-read request when we don't need data actually. It
will be used for block-stream and NBD_CMD_CACHE.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20190725100550.33801-2-vsementsov@virtuozzo.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
[eblake: comment grammar fix]
Signed-off-by: Eric Blake <eblake@redhat.com>
2019-08-15 13:22:13 -05:00
Max Reitz
43eaaaef0e block: Only the main loop can change AioContexts
bdrv_set_aio_context_ignore() can only work in the main loop:
bdrv_drained_begin() only works in the main loop and the node's (old)
AioContext; and bdrv_drained_end() really only works in the main loop
and the node's (new) AioContext (contrary to its current comment, which
is just wrong).

Consequentially, bdrv_set_aio_context_ignore() must be called from the
main loop.  Luckily, assuming that we can make block graph changes only
from the main loop as well, all its callers do that already.

Note that changing a node's context in a sense is an operation that
changes the block graph, so it actually makes sense to require this
function to be called from the main loop.

Also, fix bdrv_drained_end()'s description.  You can only use it from
the main loop or the node's AioContext, and in the latter case, the
whole subtree must be in the same context.

Fixes: e037c09c78
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190722133054.21781-3-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-07-22 18:41:43 +02:00
Max Reitz
e037c09c78 block: Do not poll in bdrv_do_drained_end()
We should never poll anywhere in bdrv_do_drained_end() (including its
recursive callees like bdrv_drain_invoke()), because it does not cope
well with graph changes.  In fact, it has been written based on the
postulation that no graph changes will happen in it.

Instead, the callers that want to poll must poll, i.e. all currently
globally available wrappers: bdrv_drained_end(),
bdrv_subtree_drained_end(), bdrv_unapply_subtree_drain(), and
bdrv_drain_all_end().  Graph changes there do not matter.

They can poll simply by passing a pointer to a drained_end_counter and
wait until it reaches 0.

This patch also adds a non-polling global wrapper for
bdrv_do_drained_end() that takes a drained_end_counter pointer.  We need
such a variant because now no function called anywhere from
bdrv_do_drained_end() must poll.  This includes
BdrvChildRole.drained_end(), which already must not poll according to
its interface documentation, but bdrv_child_cb_drained_end() just
violates that by invoking bdrv_drained_end() (which does poll).
Therefore, BdrvChildRole.drained_end() must take a *drained_end_counter
parameter, which bdrv_child_cb_drained_end() can pass on to the new
bdrv_drained_end_no_poll() function.

Note that we now have a pattern of all drained_end-related functions
either polling or receiving a *drained_end_counter to let the caller
poll based on that.

A problem with a single poll loop is that when the drained section in
bdrv_set_aio_context_ignore() ends, some nodes in the subgraph may be in
the old contexts, while others are in the new context already.  To let
the collective poll in bdrv_drained_end() work correctly, we must not
hold a lock to the old context, so that the old context can make
progress in case it is different from the current context.

(In the process, remove the comment saying that the current context is
always the old context, because it is wrong.)

In all other places, all nodes in a subtree must be in the same context,
so we can just poll that.  The exception of course is
bdrv_drain_all_end(), but that always runs in the main context, so we
can just poll NULL (like bdrv_drain_all_begin() does).

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-07-19 13:19:16 +02:00
Max Reitz
f4c8a43be0 block: Make bdrv_parent_drained_[^_]*() static
These functions are not used outside of block/io.c, there is no reason
why they should be globally available.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-07-19 13:19:16 +02:00
Max Reitz
804db8ea00 block: Introduce BdrvChild.parent_quiesce_counter
Commit 5cb2737e92 laid out why
bdrv_do_drained_end() must decrement the quiesce_counter after
bdrv_drain_invoke().  It did not give a very good reason why it has to
happen after bdrv_parent_drained_end(), instead only claiming symmetry
to bdrv_do_drained_begin().

It turns out that delaying it for so long is wrong.

Situation: We have an active commit job (i.e. a mirror job) from top to
base for the following graph:

                  filter
                    |
                  [file]
                    |
                    v
top --[backing]--> base

Now the VM is closed, which results in the job being cancelled and a
bdrv_drain_all() happening pretty much simultaneously.

Beginning the drain means the job is paused once whenever one of its
nodes is quiesced.  This is reversed when the drain ends.

With how the code currently is, after base's drain ends (which means
that it will have unpaused the job once), its quiesce_counter remains at
1 while it goes to undrain its parents (bdrv_parent_drained_end()).  For
some reason or another, undraining filter causes the job to be kicked
and enter mirror_exit_common(), where it proceeds to invoke
block_job_remove_all_bdrv().

Now base will be detached from the job.  Because its quiesce_counter is
still 1, it will unpause the job once more.  So in total, undraining
base will unpause the job twice.  Eventually, this will lead to the
job's pause_count going negative -- well, it would, were there not an
assertion against this, which crashes qemu.

The general problem is that if in bdrv_parent_drained_end() we undrain
parent A, and then undrain parent B, which then leads to A detaching the
child, bdrv_replace_child_noperm() will undrain A as if we had not done
so yet; that is, one time too many.

It follows that we cannot decrement the quiesce_counter after invoking
bdrv_parent_drained_end().

Unfortunately, decrementing it before bdrv_parent_drained_end() would be
wrong, too.  Imagine the above situation in reverse: Undraining A leads
to B detaching the child.  If we had already decremented the
quiesce_counter by that point, bdrv_replace_child_noperm() would undrain
B one time too little; because it expects bdrv_parent_drained_end() to
issue this undrain.  But bdrv_parent_drained_end() won't do that,
because B is no longer a parent.

Therefore, we have to do something else.  This patch opts for
introducing a second quiesce_counter that counts how many times a
child's parent has been quiesced (though c->role->drained_*).  With
that, bdrv_replace_child_noperm() just has to undrain the parent exactly
that many times when removing a child, and it will always be right.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-07-19 13:19:16 +02:00
Max Reitz
e5182c1c57 block: Add BDS.never_freeze
The commit and the mirror block job must be able to drop their filter
node at any point.  However, this will not be possible if any of the
BdrvChild links to them is frozen.  Therefore, we need to prevent them
from ever becoming frozen.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20190703172813.6868-2-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-07-15 15:48:40 +02:00
Andrey Shinkevich
170d3bd341 block: include base when checking image chain for block allocation
This patch is used in the 'block/stream: introduce a bottom node'
that is following. Instead of the base node, the caller may pass
the node that has the base as its backing image to the function
bdrv_is_allocated_above() with a new parameter include_base = true
and get rid of the dependency on the base that may change during
commit/stream parallel jobs. Now, if the specified base is not
found in the backing image chain, the QEMU will abort.

Suggested-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 1559152576-281803-2-git-send-email-andrey.shinkevich@virtuozzo.com
[mreitz: Squashed in the following as a rebase on conflicting patches:]
Message-id: e3cf99ae-62e9-8b6e-5a06-d3c8b9363b85@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-07-02 03:53:04 +02:00
Max Reitz
c1087f1206 block: Add bdrv_child_refresh_perms()
If a block node uses bdrv_child_try_set_perm() to change the permission
it takes on its child, the result may be very short-lived.  If anything
makes the block layer recalculate the permissions internally, it will
invoke the node driver's .bdrv_child_perm() implementation.  The
permission/shared permissions masks that returns will then override the
values previously passed to bdrv_child_try_set_perm().

If drivers want a child edge to have specific values for the
permissions/shared permissions mask, it must return them in
.bdrv_child_perm().  Consequentially, there is no need for them to pass
the same values to bdrv_child_try_set_perm() then: It is better to have
a function that invokes .bdrv_child_perm() and calls
bdrv_child_try_set_perm() with the result.  This patch adds such a
function under the name of bdrv_child_refresh_perms().

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-06-18 16:41:10 +02:00
Vladimir Sementsov-Ogievskiy
b23c580c94 block: drop bs->job
Drop remaining users of bs->job:
1. assertions actually duplicated by assert(!bs->refcnt)
2. trace-point seems not enough reason to change stream_start to return
   BlockJob pointer
3. Restricting creation of two jobs based on same bs is bad idea, as
   3.1 Some jobs creates filters to be their main node, so, this check
   don't actually prevent creating second job on same real node (which
   will create another filter node) (but I hope it is restricted by
   other mechanisms)
   3.2 Even without bs->job we have two systems of permissions:
   op-blockers and BLK_PERM
   3.3 We may want to run several jobs on one node one day

And finally, drop bs->job pointer itself. Hurrah!

Suggested-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-06-18 16:41:10 +02:00
Vladimir Sementsov-Ogievskiy
8164102ffe blockdev: blockdev_mark_auto_del: drop usage of bs->job
We are going to remove bs->job pointer. Drop it's usage in
blockdev_mark_auto_del: instead of looking at bs->job let's check all
jobs for references to bs.

Suggested-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-06-18 16:41:10 +02:00
Vladimir Sementsov-Ogievskiy
cc19f1773d block/replication: drop usage of bs->job
We are going to remove bs->job pointer. Drop it's usage in replication
code. Additionally we have to return job pointer from some mirror APIs.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-06-18 16:41:09 +02:00
Markus Armbruster
a8d2532645 Include qemu-common.h exactly where needed
No header includes qemu-common.h after this commit, as prescribed by
qemu-common.h's file comment.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190523143508.25387-5-armbru@redhat.com>
[Rebased with conflicts resolved automatically, except for
include/hw/arm/xlnx-zynqmp.h hw/arm/nrf51_soc.c hw/arm/msf2-soc.c
block/qcow2-refcount.c block/qcow2-cluster.c block/qcow2-cache.c
target/arm/cpu.h target/lm32/cpu.h target/m68k/cpu.h target/mips/cpu.h
target/moxie/cpu.h target/nios2/cpu.h target/openrisc/cpu.h
target/riscv/cpu.h target/tilegx/cpu.h target/tricore/cpu.h
target/unicore32/cpu.h target/xtensa/cpu.h; bsd-user/main.c and
net/tap-bsd.c fixed up]
2019-06-12 13:20:20 +02:00
Vladimir Sementsov-Ogievskiy
d93e572688 block/io: bdrv_pdiscard: support int64_t bytes parameter
This fixes at least one overflow in qcow2_process_discards, which
passes 64bit region length to bdrv_pdiscard where bytes (or sectors in
the past) parameter is int since its introduction in 0b919fae.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-06-04 16:55:58 +02:00
Kevin Wolf
42a65f02f9 block: Remove bdrv_set_aio_context()
All callers of bdrv_set_aio_context() are eliminated now, they have
moved to bdrv_try_set_aio_context() and related safe functions. Remove
bdrv_set_aio_context().

With this, we can now know that the .set_aio_ctx callback must be
present in bdrv_set_aio_context_ignore() because
bdrv_can_set_aio_context() would have returned false previously, so
instead of checking the condition, we can assert it.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-06-04 16:55:58 +02:00
Kevin Wolf
132ada80c4 block: Adjust AioContexts when attaching nodes
So far, we only made sure that updating the AioContext of a node
affected the whole subtree. However, if a node is newly attached to a
new parent, we also need to make sure that both the subtree of the node
and the parent are in the same AioContext. This tries to move the new
child node to the parent AioContext and returns an error if this isn't
possible.

BlockBackends now actually apply their AioContext to their root node.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-06-04 15:22:22 +02:00
Kenneth Heitke
3036a626e9 nvme: add Get/Set Feature Timestamp support
Signed-off-by: Kenneth Heitke <kenneth.heitke@intel.com>
Reviewed-by: Klaus Birkelund Jensen <klaus.jensen@cnexlabs.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-06-04 15:22:09 +02:00
Julia Suvorova
2b02fd81de block/linux-aio: Drop unused BlockAIOCB submission method
Callback-based laio_submit() and laio_cancel() were left after
rewriting Linux AIO backend to coroutines in hope that they would be
used in other code that could bypass coroutines. They can be safely
removed because they have not been used since that time.

Signed-off-by: Julia Suvorova <jusual@mail.ru>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-06-04 15:20:41 +02:00
Vladimir Sementsov-Ogievskiy
69f47505ee block: avoid recursive block_status call if possible
drv_co_block_status digs bs->file for additional, more accurate search
for hole inside region, reported as DATA by bs since 5daa74a6eb.

This accuracy is not free: assume we have qcow2 disk. Actually, qcow2
knows, where are holes and where is data. But every block_status
request calls lseek additionally. Assume a big disk, full of
data, in any iterative copying block job (or img convert) we'll call
lseek(HOLE) on every iteration, and each of these lseeks will have to
iterate through all metadata up to the end of file. It's obviously
ineffective behavior. And for many scenarios we don't need this lseek
at all.

However, lseek is needed when we have metadata-preallocated image.

So, let's detect metadata-preallocation case and don't dig qcow2's
protocol file in other cases.

The idea is to compare allocation size in POV of filesystem with
allocations size in POV of Qcow2 (by refcounts). If allocation in fs is
significantly lower, consider it as metadata-preallocation case.

102 iotest changed, as our detector can't detect shrinked file as
metadata-preallocation, which don't seem to be wrong, as with metadata
preallocation we always have valid file length.

Two other iotests have a slight change in their QMP output sequence:
Active 'block-commit' returns earlier because the job coroutine yields
earlier on a blocking operation. This operation is loading the refcount
blocks in qcow2_detect_metadata_preallocation().

Suggested-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-06-04 15:20:41 +02:00
Kevin Wolf
53a7d04185 block: Propagate AioContext change to parents
All block nodes and users in any connected component of the block graph
must be in the same AioContext, so changing the AioContext of one node
must not only change all of its children, but all of its parents (and
in turn their children etc.) as well.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-05-20 17:08:56 +02:00
Kevin Wolf
a3a683c33d block: Make bdrv_attach/detach_aio_context() static
Since commit b97511c7bc, there is no reason for block drivers any more
to call these functions (see the function comment in block_int.h). They
are now just internal helper functions for bdrv_set_aio_context()
and can be made static.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-05-20 17:08:56 +02:00
Kevin Wolf
5d2318499f block: Add bdrv_try_set_aio_context()
Eventually, we want to make sure that all parents and all children of a
node are in the same AioContext as the node itself. This means that
changing the AioContext may fail because one of the other involved
parties (e.g. a guest device that was configured with an iothread)
cannot allow switching to a different AioContext.

Introduce a set of functions that allow to first check whether all
involved nodes can switch to a new context and only then do the actual
switch. The check recursively covers children and parents.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-05-20 17:08:56 +02:00
Peter Maydell
01807c8b0e Miscellaneous patches for 2019-05-13
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Merge remote-tracking branch 'remotes/armbru/tags/pull-misc-2019-05-13' into staging

Miscellaneous patches for 2019-05-13

# gpg: Signature made Mon 13 May 2019 08:04:02 BST
# gpg:                using RSA key 3870B400EB918653
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>" [full]
# gpg:                 aka "Markus Armbruster <armbru@pond.sub.org>" [full]
# Primary key fingerprint: 354B C8B3 D7EB 2A6B 6867  4E5F 3870 B400 EB91 8653

* remotes/armbru/tags/pull-misc-2019-05-13:
  Clean up decorations and whitespace around header guards
  Normalize header guard symbol definition.
  Clean up ill-advised or unusual header guards
  Clean up header guards that don't match their file name
  target/xtensa: Clean up core-isa.h header guards
  linux-user/nios2 linux-user/riscv: Clean up header guards
  authz: Normalize #include "authz/trace.h" to "trace.h"
  Use #include "..." for our own headers, <...> for others
  Clean up includes

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-05-13 13:55:13 +01:00
Markus Armbruster
6834c3f410 Clean up decorations and whitespace around header guards
Cleaned up with scripts/clean-header-guards.pl.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190315145123.28030-9-armbru@redhat.com>
2019-05-13 08:58:55 +02:00
Alberto Garcia
2e11d7562a block: Remove bdrv_read() and bdrv_write()
No one is using these functions anymore, all callers have switched to
the byte-based bdrv_pread() and bdrv_pwrite()

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-05-10 16:45:40 +02:00
Max Reitz
c4e2aff81b qemu-nbd: Look up flag names in array
The existing code to convert flag bits into strings looks a bit strange
now, and if we ever add more flags, it will look even stranger.  Prevent
that from happening by making it look up the flag names in an array.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20190405191635.25740-1-mreitz@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2019-05-07 09:43:42 -05:00
Vladimir Sementsov-Ogievskiy
371420e217 block: introduce byte-based io helpers
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-04-30 15:29:00 +02:00
Markus Armbruster
e1ce7d747b block/qapi: Clean up how we print to monitor or stdout
bdrv_snapshot_dump(), bdrv_image_info_specific_dump(),
bdrv_image_info_dump() and their helpers take an fprintf()-like
callback and a FILE * to pass to it.

hmp.c passes monitor_printf() cast to fprintf_function and the current
monitor cast to FILE *.

qemu-img.c and qemu-io-cmds.c pass fprintf and stdout.

The type-punning is technically undefined behaviour, but works in
practice.  Clean up: drop the callback, and call qemu_printf()
instead.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20190417191805.28198-8-armbru@redhat.com>
2019-04-18 22:18:59 +02:00
Markus Armbruster
ac7ff4cf5f qsp: Simplify how qsp_report() prints
qsp_report() takes an fprintf()-like callback and a FILE * to pass to
it.

Its only caller hmp_sync_profile() passes monitor_fprintf() and the
current monitor cast to FILE *.  monitor_fprintf() casts it right
back, and is otherwise identical to monitor_printf().  The
type-punning is ugly.

Drop the callback, and call qemu_printf() instead.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20190417191805.28198-7-armbru@redhat.com>
2019-04-18 22:18:59 +02:00
Kevin Wolf
738301e117 file-posix: Support BDRV_REQ_NO_FALLBACK for zero writes
We know that the kernel implements a slow fallback code path for
BLKZEROOUT, so if BDRV_REQ_NO_FALLBACK is given, we shouldn't call it.
The other operations we call in the context of .bdrv_co_pwrite_zeroes
should usually be quick, so no modification should be needed for them.
If we ever notice that there are additional problematic cases, we can
still make these conditional as well.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Eric Blake <eblake@redhat.com>
2019-03-26 11:37:51 +01:00
Kevin Wolf
fe0480d629 block: Add BDRV_REQ_NO_FALLBACK
For qemu-img convert, we want an operation that zeroes out the whole
image if this can be done efficiently, but that returns an error
otherwise so we don't write explicit zeroes and immediately overwrite
them with the real data, potentially doubling the amount of data to be
written.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Eric Blake <eblake@redhat.com>
2019-03-26 11:37:51 +01:00
Peter Maydell
523a2a42c3 Pull request
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Merge remote-tracking branch 'remotes/jnsnow/tags/bitmaps-pull-request' into staging

Pull request

# gpg: Signature made Tue 12 Mar 2019 20:23:08 GMT
# gpg:                using RSA key F9B7ABDBBCACDF95BE76CBD07DEF8106AAFC390E
# gpg: Good signature from "John Snow (John Huston) <jsnow@redhat.com>" [full]
# Primary key fingerprint: FAEB 9711 A12C F475 812F  18F2 88A9 064D 1835 61EB
#      Subkey fingerprint: F9B7 ABDB BCAC DF95 BE76  CBD0 7DEF 8106 AAFC 390E

* remotes/jnsnow/tags/bitmaps-pull-request: (22 commits)
  tests/qemu-iotests: add bitmap resize test 246
  block/qcow2-bitmap: Allow resizes with persistent bitmaps
  block/qcow2-bitmap: Don't check size for IN_USE bitmap
  docs/interop/qcow2: Improve bitmap flag in_use specification
  bitmaps: Fix typo in function name
  block/dirty-bitmaps: implement inconsistent bit
  block/dirty-bitmaps: disallow busy bitmaps as merge source
  block/dirty-bitmaps: prohibit removing readonly bitmaps
  block/dirty-bitmaps: prohibit readonly bitmaps for backups
  block/dirty-bitmaps: add block_dirty_bitmap_check function
  block/dirty-bitmap: add inconsistent status
  block/dirty-bitmaps: add inconsistent bit
  iotests: add busy/recording bit test to 124
  blockdev: remove unused paio parameter documentation
  block/dirty-bitmaps: move comment block
  block/dirty-bitmaps: unify qmp_locked and user_locked calls
  block/dirty-bitmap: explicitly lock bitmaps with successors
  nbd: change error checking order for bitmaps
  block/dirty-bitmap: change semantics of enabled predicate
  block/dirty-bitmap: remove set/reset assertions against enabled bit
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

# Conflicts:
#	tests/qemu-iotests/group
2019-03-13 17:30:34 +00:00
Alberto Garcia
5019aece2a block: Remove the AioContext parameter from bdrv_reopen_multiple()
This parameter has been unused since 1a63a90750

Signed-off-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-03-12 20:30:14 +01:00
Alberto Garcia
8a2ce0bc1e block: Add a 'mutable_opts' field to BlockDriver
If we reopen a BlockDriverState and there is an option that is present
in bs->options but missing from the new set of options then we have to
return an error unless the driver is able to reset it to its default
value.

This patch adds a new 'mutable_opts' field to BlockDriver. This is
a list of runtime options that can be modified during reopen. If an
option in this list is unspecified on reopen then it must be reset (or
return an error).

Signed-off-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-03-12 20:30:14 +01:00
Alberto Garcia
cb828c31de block: Allow changing the backing file on reopen
This patch allows the user to change the backing file of an image that
is being reopened. Here's what it does:

 - In bdrv_reopen_prepare(): check that the value of 'backing' points
   to an existing node or is null. If it points to an existing node it
   also needs to make sure that replacing the backing file will not
   create a cycle in the node graph (i.e. you cannot reach the parent
   from the new backing file).

 - In bdrv_reopen_commit(): perform the actual node replacement by
   calling bdrv_set_backing_hd().

There may be temporary implicit nodes between a BDS and its backing
file (e.g. a commit filter node). In these cases bdrv_reopen_prepare()
looks for the real (non-implicit) backing file and requires that the
'backing' option points to it. Replacing or detaching a backing file
is forbidden if there are implicit nodes in the middle.

Although x-blockdev-reopen is meant to be used like blockdev-add,
there's an important thing that must be taken into account: the only
way to set a new backing file is by using a reference to an existing
node (previously added with e.g. blockdev-add).  If 'backing' contains
a dictionary with a new set of options ({"driver": "qcow2", "file": {
... }}) then it is interpreted that the _existing_ backing file must
be reopened with those options.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-03-12 20:30:14 +01:00
Alberto Garcia
8546632e61 block: Handle child references in bdrv_reopen_queue()
Children in QMP are specified with BlockdevRef / BlockdevRefOrNull,
which can contain a set of child options, a child reference, or
NULL. In optional attributes like "backing" it can also be missing.

Only the first case (set of child options) is being handled properly
by bdrv_reopen_queue(). This patch deals with all the others.

Here's how these cases should be handled when bdrv_reopen_queue() is
deciding what to do with each child of a BlockDriverState:

   1) Set of child options: if the child was implicitly created (i.e
      inherits_from points to the parent) then the options are removed
      from the parent's options QDict and are passed to the child with
      a recursive bdrv_reopen_queue() call. This case was already
      working fine.

   2) Child reference: there's two possibilites here.

      2a) Reference to the current child: if the child was implicitly
          created then it is put in the reopen queue, keeping its
          current set of options (since this was a child reference
          there was no way to specify a different set of options).
          If the child is not implicit then it keeps its current set
          of options but it is not reopened (and therefore does not
          inherit any new option from the parent).

      2b) Reference to a different BDS: the current child is not put
          in the reopen queue at all. Passing a reference to a
          different BDS can be used to replace a child, although at
          the moment no driver implements this, so it results in an
          error. In any case, the current child is not going to be
          reopened (and might in fact disappear if it's replaced)

   3) NULL: This is similar to (2b). Although no driver allows this
      yet it can be used to detach the current child so it should not
      be put in the reopen queue.

   4) Missing option: at the moment "backing" is the only case where
      this can happen. With "blockdev-add", leaving "backing" out
      means that the default backing file is opened. We don't want to
      open a new image during reopen, so we require that "backing" is
      always present. We'll relax this requirement a bit in the next
      patch. If keep_old_opts is true and "backing" is missing then
      this behaves like 2a (the current child is reopened).

Signed-off-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-03-12 20:30:14 +01:00
Alberto Garcia
077e8e2018 block: Add 'keep_old_opts' parameter to bdrv_reopen_queue()
The bdrv_reopen_queue() function is used to create a queue with
the BDSs that are going to be reopened and their new options. Once
the queue is ready bdrv_reopen_multiple() is called to perform the
operation.

The original options from each one of the BDSs are kept, with the new
options passed to bdrv_reopen_queue() applied on top of them.

For "x-blockdev-reopen" we want a function that behaves much like
"blockdev-add". We want to ignore the previous set of options so that
only the ones actually specified by the user are applied, with the
rest having their default values.

One of the things that we need is a way to tell bdrv_reopen_queue()
whether we want to keep the old set of options or not, and that's what
this patch does. All current callers are setting this new parameter to
true and x-blockdev-reopen will set it to false.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-03-12 20:30:14 +01:00
Alberto Garcia
2cad1ebe70 block: Allow freezing BdrvChild links
Our permission system is useful to define what operations are allowed
on a certain block node and includes things like BLK_PERM_WRITE or
BLK_PERM_RESIZE among others.

One of the permissions is BLK_PERM_GRAPH_MOD which allows "changing
the node that this BdrvChild points to". The exact meaning of this has
never been very clear, but it can be understood as "change any of the
links connected to the node". This can be used to prevent changing a
backing link, but it's too coarse.

This patch adds a new 'frozen' attribute to BdrvChild, which forbids
detaching the link from the node it points to, and new API to freeze
and unfreeze a backing chain.

After this change a few functions can fail, so they need additional
checks.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-03-12 20:30:14 +01:00
Eric Blake
796a3798ab bitmaps: Fix typo in function name
Commit a88b179f introduced the ability to set and query bitmap
persistence, but with an atypical spelling.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-id: 20190308205845.25734-1-eblake@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2019-03-12 12:05:49 -04:00
John Snow
3ae96d6684 block/dirty-bitmaps: add block_dirty_bitmap_check function
Instead of checking against busy, inconsistent, or read only directly,
use a check function with permissions bits that let us streamline the
checks without reproducing them in many places.

Included in this patch are permissions changes that simply add the
inconsistent check to existing permissions call spots, without
addressing existing bugs.

In general, this means that busy+readonly checks become BDRV_BITMAP_DEFAULT,
which checks against all three conditions. busy-only checks become
BDRV_BITMAP_ALLOW_RO.

Notably, remove allows inconsistent bitmaps, so it doesn't follow the pattern.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20190301191545.8728-4-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2019-03-12 12:05:49 -04:00
John Snow
b0f455599d block/dirty-bitmaps: add inconsistent bit
Add an inconsistent bit to dirty-bitmaps that allows us to report a bitmap as
persistent but potentially inconsistent, i.e. if we find bitmaps on a qcow2
that have been marked as "in use".

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20190301191545.8728-2-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2019-03-12 12:05:49 -04:00
John Snow
27a1b301a4 block/dirty-bitmaps: unify qmp_locked and user_locked calls
These mean the same thing now. Unify them and rename the merged call
bdrv_dirty_bitmap_busy to indicate semantically what we are describing,
as well as help disambiguate from the various _locked and _unlocked
versions of bitmap helpers that refer to mutex locks.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20190223000614.13894-8-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2019-03-12 12:05:48 -04:00
John Snow
50a47257f8 block/dirty-bitmaps: rename frozen predicate helper
"Frozen" was a good description a long time ago, but it isn't adequate now.
Rename the frozen predicate to has_successor to make the semantics of the
predicate more clear to outside callers.

In the process, remove some calls to frozen() that no longer semantically
make sense. For bdrv_enable_dirty_bitmap_locked and
bdrv_disable_dirty_bitmap_locked, it doesn't make sense to prohibit QEMU
internals from performing this action when we only wished to prohibit QMP
users from issuing these commands. All of the QMP API commands for bitmap
manipulation already check against user_locked() to prohibit these actions.

Several other assertions really want to check that the bitmap isn't in-use
by another operation -- use the bitmap_user_locked function for this instead,
which presently also checks for has_successor. This leaves some redundant
checks of has_successor through different helpers that are addressed in
forthcoming patches.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20190223000614.13894-3-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2019-03-12 12:05:48 -04:00
Peter Maydell
e2a18635a4 nbd patches for 2019-03-08
- support TLS client authorization in NBD servers
 - iotest 223 race fix
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Merge remote-tracking branch 'remotes/ericb/tags/pull-nbd-2019-03-08' into staging

nbd patches for 2019-03-08

- support TLS client authorization in NBD servers
- iotest 223 race fix

# gpg: Signature made Fri 08 Mar 2019 17:37:59 GMT
# gpg:                using RSA key A7A16B4A2527436A
# gpg: Good signature from "Eric Blake <eblake@redhat.com>" [full]
# gpg:                 aka "Eric Blake (Free Software Programmer) <ebb9@byu.net>" [full]
# gpg:                 aka "[jpeg image of size 6874]" [full]
# Primary key fingerprint: 71C2 CC22 B1C4 6029 27D2  F3AA A7A1 6B4A 2527 436A

* remotes/ericb/tags/pull-nbd-2019-03-08:
  iotests: Wait for qemu to end in 223
  nbd: fix outdated qapi docs syntax for tls-creds
  nbd: allow authorization with nbd-server-start QMP command
  qemu-nbd: add support for authorization of TLS clients

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-03-09 20:55:44 +00:00
Kevin Wolf
6c3944dc62 qcow2: Implement data-file-raw create option
Provide an option to force QEMU to always keep the external data file
consistent as a standalone read-only raw image.

At the moment, this means making sure that write_zeroes requests are
forwarded to the data file instead of just updating the metadata, and
checking that no backing file is used.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-03-08 12:26:46 +01:00
Kevin Wolf
dcc98687f8 qcow2: Creating images with external data file
This adds a .bdrv_create option to use an external data file.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-03-08 12:26:46 +01:00
Andrey Shinkevich
9ac404c523 block: iterate_format with account of whitelisting
bdrv_iterate_format (which is currently only used for printing out the
formats supported by the block layer) doesn't take format whitelisting
into account.

This creates a problem for tests: they enumerate supported formats to
decide which tests to enable, but then discover that QEMU doesn't let
them actually use some of those formats.

To avoid that, exclude formats that are not whitelisted from
enumeration, if whitelisting is in use.  Since we have separate
whitelists for r/w and r/o, take this a parameter to
bdrv_iterate_format, and print two lists of supported formats (r/w and
r/o) in main qemu.

Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-03-08 12:26:45 +01:00
Daniel P. Berrange
000194556b nbd: allow authorization with nbd-server-start QMP command
As with the previous patch to qemu-nbd, the nbd-server-start QMP command
also needs to be able to specify authorization when enabling TLS encryption.

First the client must create a QAuthZ object instance using the
'object-add' command:

   {
     'execute': 'object-add',
     'arguments': {
       'qom-type': 'authz-list',
       'id': 'authz0',
       'parameters': {
         'policy': 'deny',
         'rules': [
           {
             'match': '*CN=fred',
             'policy': 'allow'
           }
         ]
       }
     }
   }

They can then reference this in the new 'tls-authz' parameter when
executing the 'nbd-server-start' command:

   {
     'execute': 'nbd-server-start',
     'arguments': {
       'addr': {
           'type': 'inet',
           'host': '127.0.0.1',
           'port': '9000'
       },
       'tls-creds': 'tls0',
       'tls-authz': 'authz0'
     }
   }

Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-Id: <20190227162035.18543-3-berrange@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2019-03-06 11:05:27 -06:00
Daniel P. Berrange
b25e12daff qemu-nbd: add support for authorization of TLS clients
Currently any client which can complete the TLS handshake is able to use
the NBD server. The server admin can turn on the 'verify-peer' option
for the x509 creds to require the client to provide a x509 certificate.
This means the client will have to acquire a certificate from the CA
before they are permitted to use the NBD server. This is still a fairly
low bar to cross.

This adds a '--tls-authz OBJECT-ID' option to the qemu-nbd command which
takes the ID of a previously added 'QAuthZ' object instance. This will
be used to validate the client's x509 distinguished name. Clients
failing the authorization check will not be permitted to use the NBD
server.

For example to setup authorization that only allows connection from a client
whose x509 certificate distinguished name is

   CN=laptop.example.com,O=Example Org,L=London,ST=London,C=GB

escape the commas in the name and use:

  qemu-nbd --object tls-creds-x509,id=tls0,dir=/home/berrange/qemutls,\
                    endpoint=server,verify-peer=yes \
           --object 'authz-simple,id=auth0,identity=CN=laptop.example.com,,\
                     O=Example Org,,L=London,,ST=London,,C=GB' \
           --tls-creds tls0 \
           --tls-authz authz0 \
	   ....other qemu-nbd args...

NB: a real shell command line would not have leading whitespace after
the line continuation, it is just included here for clarity.

Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-Id: <20190227162035.18543-2-berrange@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[eblake: split long line in --help text, tweak 233 to show that whitespace
after ,, in identity= portion is actually okay]
Signed-off-by: Eric Blake <eblake@redhat.com>
2019-03-06 11:05:27 -06:00
Max Reitz
998b3a1e5a block: Purify .bdrv_refresh_filename()
Currently, BlockDriver.bdrv_refresh_filename() is supposed to both
refresh the filename (BDS.exact_filename) and set BDS.full_open_options.
Now that we have generic code in the central bdrv_refresh_filename() for
creating BDS.full_open_options, we can drop the latter part from all
BlockDriver.bdrv_refresh_filename() implementations.

This also means that we can drop all of the existing default code for
this from the global bdrv_refresh_filename() itself.

Furthermore, we now have to call BlockDriver.bdrv_refresh_filename()
after having set BDS.full_open_options, because the block driver's
implementation should now be allowed to depend on BDS.full_open_options
being set correctly.

Finally, with this patch we can drop the @options parameter from
BlockDriver.bdrv_refresh_filename(); also, add a comment on this
function's purpose in block/block_int.h while touching its interface.

This completely obsoletes blklogwrite's implementation of
.bdrv_refresh_filename().

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190201192935.18394-25-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-25 15:11:27 +01:00
Max Reitz
abc521a9aa block: Add BlockDriver.bdrv_gather_child_options
Some follow-up patches will rework the way bs->full_open_options is
refreshed in bdrv_refresh_filename(). The new implementation will remove
the need for the block drivers' bdrv_refresh_filename() implementations
to set bs->full_open_options; instead, it will be generic and use static
information from each block driver.

However, by implementing bdrv_gather_child_options(), block drivers will
still be able to override the way the full_open_options of their
children are incorporated into their own.

We need to implement this function for VMDK because we have to prevent
the generic implementation from gathering the options of all children:
It is not possible to specify options for the extents through the
runtime options.

For quorum, the child names that would be used by the generic
implementation and the ones that we actually (currently) want to use
differ. See quorum_gather_child_options() for more information.

Note that both of these are cases which are not ideal: In case of VMDK
it would probably be nice to be able to specify options for all extents.
In case of quorum, the current runtime option structure is simply broken
and needs to be fixed (but that is left for another patch).

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20190201192935.18394-23-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-25 15:11:27 +01:00
Max Reitz
2654267cc1 block: Add strong_runtime_opts to BlockDriver
This new field can be set by block drivers to list the runtime options
they accept that may influence the contents of the respective BDS. As of
a follow-up patch, this list will be used by the common
bdrv_refresh_filename() implementation to decide which options to put
into BDS.full_open_options (and consequently whether a JSON filename has
to be created), thus freeing the drivers of having to implement that
logic themselves.

Additionally, this patch adds the field to all of the block drivers that
need it and sets it accordingly.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20190201192935.18394-22-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-25 15:11:27 +01:00
Max Reitz
1e89d0f9be block: Add bdrv_dirname()
This function may be implemented by block drivers to derive a directory
name from a BDS. Concatenating this g_free()-able string with a relative
filename must result in a valid (not necessarily existing) filename, so
this is a function that should generally be not implemented by format
drivers, because this is protocol-specific.

If a BDS's driver does not implement this function, bdrv_dirname() will
fall through to the BDS's file if it exists. If it does not, the
exact_filename field will be used to generate a directory name.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20190201192935.18394-15-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-25 15:11:26 +01:00
Max Reitz
6b6833c1b4 block: bdrv_get_full_backing_filename's ret. val.
Make bdrv_get_full_backing_filename() return an allocated string instead
of placing the result in a caller-provided buffer.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20190201192935.18394-12-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-25 15:11:26 +01:00
Max Reitz
645ae7d88e block: bdrv_get_full_backing_filename_from_...'s ret. val.
Make bdrv_get_full_backing_filename_from_filename() return an allocated
string instead of placing the result in a caller-provided buffer.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190201192935.18394-11-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-25 15:11:26 +01:00
Max Reitz
009b03aaa2 block: Make path_combine() return the path
Besides being safe for arbitrary path lengths, after some follow-up
patches all callers will want a freshly allocated buffer anyway.

In the meantime, path_combine_deprecated() is added which has the same
interface as path_combine() had before this patch. All callers to that
function will be converted in follow-up patches.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-id: 20190201192935.18394-10-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-25 15:11:26 +01:00
Max Reitz
998c201923 block: Add BDS.auto_backing_file
If the backing file is overridden, this most probably does change the
guest-visible data of a BDS.  Therefore, we will need to consider this
in bdrv_refresh_filename().

To see whether it has been overridden, we might want to compare
bs->backing_file and bs->backing->bs->filename.  However,
bs->backing_file is changed by bdrv_set_backing_hd() (which is just used
to change the backing child at runtime, without modifying the image
header), so bs->backing_file most of the time simply contains a copy of
bs->backing->bs->filename anyway, so it is useless for such a
comparison.

This patch adds an auto_backing_file BDS field which contains the
backing file path as indicated by the image header, which is not changed
by bdrv_set_backing_hd().

Because of bdrv_refresh_filename() magic, however, a BDS's filename may
differ from what has been specified during bdrv_open().  Then, the
comparison between bs->auto_backing_file and bs->backing->bs->filename
may fail even though bs->backing was opened from bs->auto_backing_file.
To mitigate this, we can copy the real BDS's filename (after the whole
bdrv_open() and bdrv_refresh_filename() process) into
bs->auto_backing_file, if we know the former has been opened based on
the latter.  This is only possible if no options modifying the backing
file's behavior have been specified, though.  To simplify things, this
patch only copies the filename from the backing file if no options have
been specified for it at all.

Furthermore, there are cases where an overlay is created by qemu which
already contains a BDS's filename (e.g. in blockdev-snapshot-sync).  We
do not need to worry about updating the overlay's bs->auto_backing_file
there, because we actually wrote a post-bdrv_refresh_filename() filename
into the image header.

So all in all, there will be false negatives where (as of a future
patch) bdrv_refresh_filename() will assume that the backing file differs
from what was specified in the image header, even though it really does
not.  However, these cases should be limited to where (1) the user
actually did override something in the backing chain (e.g. by specifying
options for the backing file), or (2) the user executed a QMP command to
change some node's backing file (e.g. change-backing-file or
block-commit with @backing-file given) where the given filename does not
happen to coincide with qemu's idea of the backing BDS's filename.

Then again, (1) really is limited to -drive.  With -blockdev or
blockdev-add, you have to adhere to the schema, so a user cannot give
partial "unimportant" options (e.g. by just setting backing.node-name
and leaving the rest to the image header).  Therefore, trying to fix
this would mean trying to fix something for -drive only.

To improve on (2), we would need a full infrastructure to "canonicalize"
an arbitrary filename (+ options), so it can be compared against
another.  That seems a bit over the top, considering that filenames
nowadays are there mostly for the user's entertainment.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20190201192935.18394-5-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-25 15:11:25 +01:00
Max Reitz
f30c66ba6e block: Use bdrv_refresh_filename() to pull
Before this patch, bdrv_refresh_filename() is used in a pushing manner:
Whenever the BDS graph is modified, the parents of the modified edges
are supposed to be updated (recursively upwards).  However, that is
nonviable, considering that we want child changes not to concern
parents.

Also, in the long run we want a pull model anyway: Here, we would have a
bdrv_filename() function which returns a BDS's filename, freshly
constructed.

This patch is an intermediate step.  It adds bdrv_refresh_filename()
calls before every place a BDS.filename value is used.  The only
exceptions are protocol drivers that use their own filename, which
clearly would not profit from refreshing that filename before.

Also, bdrv_get_encrypted_filename() is removed along the way (as a user
of BDS.filename), since it is completely unused.

In turn, all of the calls to bdrv_refresh_filename() before this patch
are removed, because we no longer have to call this function on graph
changes.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190201192935.18394-2-mreitz@redhat.com
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-02-25 15:11:25 +01:00
Vladimir Sementsov-Ogievskiy
f962e96150 block: fix bdrv_check_perm for non-tree subgraph
bdrv_check_perm in it's recursion checks each node in context of new
permissions for one parent, because of nature of DFS. It works well,
while children subgraph of top-most updated node is a tree, i.e. it
doesn't have any kind of loops. But if we have a loop (not oriented,
of course), i.e. we have two different ways from top-node to some
child-node, then bdrv_check_perm will do wrong thing:

  top
  | \
  |  |
  v  v
  A  B
  |  |
  v  v
  node

It will once check new permissions of node in context of new A
permissions and old B permissions and once visa-versa. It's a wrong way
and may lead to corruption of permission system. We may start with
no-permissions and all-shared for both A->node and B->node relations
and finish up with non shared write permission for both ways.

The following commit will add a test, which shows this bug.

To fix this situation, let's really set BdrvChild permissions during
bdrv_check_perm procedure. And we are happy here, as check-perm is
already written in transaction manner, so we just need to restore
backed-up permissions in _abort.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-02-25 15:03:19 +01:00
Kevin Wolf
d3bd5b9089 nbd: Use low-level QIOChannel API in nbd_read_eof()
Instead of using the convenience wrapper qio_channel_read_all_eof(), use
the lower level QIOChannel API. This means duplicating some code, but
we'll need this because this coroutine yield is special: We want it to
be interruptible so that nbd_client_attach_aio_context() can correctly
reenter the coroutine.

This moves the bdrv_dec/inc_in_flight() pair into nbd_read_eof(), so
that connection_co will always sit in this exact qio_channel_yield()
call when bdrv_drain() returns.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2019-02-25 15:03:19 +01:00
Kevin Wolf
a7b78fc944 nbd: Move nbd_read_eof() to nbd/client.c
The only caller of nbd_read_eof() is nbd_receive_reply(), so it doesn't
have to live in the header file, but can move next to its caller.

Also add the missing coroutine_fn to the function and its caller.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2019-02-25 15:03:19 +01:00
Daniel Henrique Barboza
8c04093c8c block/snapshot: remove bdrv_snapshot_delete_by_id_or_name
After the previous patch, the only instance of this function left
is inside qemu-img.c.

qemu-img is using it inside the 'img_snapshot' function to delete
snapshots in the SNAPSHOT_DELETE case, based on a "snapshot_name"
string that refers to the tag, not ID, of the QEMUSnapshotInfo struct.
This can be verified by checking the SNAPSHOT_CREATE case that
comes shortly before SNAPSHOT_DELETE. In that case, the same
"snapshot_name" variable is being strcpy to the 'name' field
of the QEMUSnapshotInfo struct sn:

pstrcpy(sn.name, sizeof(sn.name), snapshot_name);

Based on that, it is unlikely that "snapshot_name" might contain
an "id" in SNAPSHOT_DELETE.

This patch changes SNAPSHOT_DELETE to use snapshot_find() and
snapshot_delete() instead of bdrv_snapshot_delete_by_id_or_name.
After that, there is no instances left of bdrv_snapshot_delete_by_id_or_name
in the code, so it is safe to remove it entirely.

Suggested-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-02-25 15:03:18 +01:00
Andrey Shinkevich
1bf6e9ca92 bdrv_query_image_info Error parameter added
Inform a user in case qcow2_get_specific_info fails to obtain
QCOW2 image specific information. This patch is preliminary to
the one "qcow2: Add list of bitmaps to ImageInfoSpecificQCow2".

Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <1549638368-530182-2-git-send-email-andrey.shinkevich@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2019-02-11 14:35:43 -06:00
Vladimir Sementsov-Ogievskiy
e6798f06a6 nbd: generalize usage of nbd_read
We generally do very similar things around nbd_read: error_prepend
specifying what we have tried to read, and be_to_cpu conversion of
integers.

So, it seems reasonable to move common things to helper functions,
which:
1. simplify code a bit
2. generalize nbd_read error descriptions, all starting with
   "Failed to read"
3. make it more difficult to forget to convert things from BE

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20190128165830.165170-1-vsementsov@virtuozzo.com>
[eblake: rename macro to DEF_NBD_READ_N and formatting tweaks;
checkpatch has false positive complaint]
Signed-off-by: Eric Blake <eblake@redhat.com>
2019-02-04 15:11:27 -06:00
Vladimir Sementsov-Ogievskiy
5d3b4e9946 qapi: add x-debug-query-block-graph
Add a new command, returning block nodes (and their users) graph.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20181221170909.25584-2-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-01-31 00:38:19 +01:00
Stefan Hajnoczi
bc19a0a6e4 throttle-groups: fix restart coroutine iothread race
The following QMP command leads to a crash when iothreads are used:

  { 'execute': 'device_del', 'arguments': {'id': 'data'} }

The backtrace involves the queue restart coroutine where
tgm->throttle_state is a NULL pointer because
throttle_group_unregister_tgm() has already been called:

  (gdb) bt full
  #0  0x00005585a7a3b378 in qemu_mutex_lock_impl (mutex=0xffffffffffffffd0, file=0x5585a7bb3d54 "block/throttle-groups.c", line=412) at util/qemu-thread-posix.c:64
        err = <optimized out>
        __PRETTY_FUNCTION__ = "qemu_mutex_lock_impl"
        __func__ = "qemu_mutex_lock_impl"
  #1  0x00005585a79be074 in throttle_group_restart_queue_entry (opaque=0x5585a9de4eb0) at block/throttle-groups.c:412
        _f = <optimized out>
        data = 0x5585a9de4eb0
        tgm = 0x5585a9079440
        ts = 0x0
        tg = 0xffffffffffffff98
        is_write = false
        empty_queue = 255

This coroutine should not execute in the iothread after the throttle
group member has been unregistered!

The root cause is that the device_del code path schedules the restart
coroutine in the iothread while holding the AioContext lock.  Therefore
the iothread cannot execute the coroutine until after device_del
releases the lock - by this time it's too late.

This patch adds a reference count to ThrottleGroupMember so we can
synchronously wait for restart coroutines to complete.  Once they are
done it is safe to unregister the ThrottleGroupMember.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20190114133257.30299-2-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-01-24 10:02:28 +00:00
Eric Blake
0b576b6bfb nbd/client: Add meta contexts to nbd_receive_export_list()
We want to be able to detect whether a given qemu NBD server is
exposing the right export(s) and dirty bitmaps, at least for
regression testing.  We could use 'nbd-client -l' from the upstream
NBD project to list exports, but it's annoying to rely on
out-of-tree binaries; furthermore, nbd-client doesn't necessarily
know about all of the qemu NBD extensions.  Thus, we plan on adding
a new mode to qemu-nbd that merely sniffs all possible information
from the server during handshake phase, then disconnects and dumps
the information.

This patch continues the work of the previous patch, by adding the
ability to track the list of available meta contexts into
NBDExportInfo.  It benefits from the recent refactoring patches
with a new nbd_list_meta_contexts() that reuses much of the same
framework as setting a meta context.

Note: a malicious server could exhaust memory of a client by feeding
an unending loop of contexts; perhaps we could place a limit on how
many we are willing to receive. But this is no different from our
earlier analysis on a server sending an unending list of exports,
and the death of a client due to memory exhaustion when the client
was going to exit soon anyways is not really a denial of service
attack.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Richard W.M. Jones <rjones@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20190117193658.16413-19-eblake@redhat.com>
2019-01-21 15:49:52 -06:00
Eric Blake
d21a2d3451 nbd/client: Add nbd_receive_export_list()
We want to be able to detect whether a given qemu NBD server is
exposing the right export(s) and dirty bitmaps, at least for
regression testing.  We could use 'nbd-client -l' from the upstream
NBD project to list exports, but it's annoying to rely on
out-of-tree binaries; furthermore, nbd-client doesn't necessarily
know about all of the qemu NBD extensions.  Thus, we plan on adding
a new mode to qemu-nbd that merely sniffs all possible information
from the server during handshake phase, then disconnects and dumps
the information.

This patch adds the low-level client code for grabbing the list
of exports.  It benefits from the recent refactoring patches, in
order to share as much code as possible when it comes to doing
validation of server replies.  The resulting information is stored
in an array of NBDExportInfo which has been expanded to any
description string, along with a convenience function for freeing
the list.

Note: a malicious server could exhaust memory of a client by feeding
an unending loop of exports; perhaps we should place a limit on how
many we are willing to receive. But note that a server could
reasonably be serving an export for every file in a large directory,
where an arbitrary limit in the client means we can't list anything
from such a server; the same happens if we just run until the client
fails to malloc() and thus dies by an abort(), where the limit is
no longer arbitrary but determined by available memory.  Since the
client is already planning on being short-lived, it's hard to call
this a denial of service attack that would starve off other uses,
so it does not appear to be a security issue.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Richard W.M. Jones <rjones@redhat.com>
Message-Id: <20190117193658.16413-18-eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2019-01-21 15:49:52 -06:00
Eric Blake
2df94eb52b nbd/client: Change signature of nbd_negotiate_simple_meta_context()
Pass 'info' instead of three separate parameters related to info,
when requesting the server to set the meta context.  Update the
NBDExportInfo struct to rename the received id field to match the
fact that we are currently overloading the field to match whatever
context the user supplied through the x-dirty-bitmap hack, as well
as adding a TODO comment to remind future patches about a desire
to request two contexts at once.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Richard W.M. Jones <rjones@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20190117193658.16413-11-eblake@redhat.com>
2019-01-21 15:49:52 -06:00
Eric Blake
6dc1667d68 nbd/client: Move export name into NBDExportInfo
Refactor the 'name' parameter of nbd_receive_negotiate() from
being a separate parameter into being part of the in-out 'info'.
This also spills over to a simplification of nbd_opt_go().

The main driver for this refactoring is that an upcoming patch
would like to add support to qemu-nbd to list information about
all exports available on a server, where the name(s) will be
provided by the server instead of the client.  But another benefit
is that we can now allow the client to explicitly specify the
empty export name "" even when connecting to an oldstyle server
(even if qemu is no longer such a server after commit 7f7dfe2a).

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Richard W.M. Jones <rjones@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20190117193658.16413-10-eblake@redhat.com>
2019-01-21 15:49:52 -06:00
Eric Blake
9d26dfcbab nbd/server: Favor [u]int64_t over off_t
Although our compile-time environment is set up so that we always
support long files with 64-bit off_t, we have no guarantee whether
off_t is the same type as int64_t.  This requires casts when
printing values, and prevents us from directly using qemu_strtoi64()
(which will be done in the next patch). Let's just flip to uint64_t
where possible, and stick to int64_t for detecting failure of
blk_getlength(); we also keep the assertions added in the previous
patch that the resulting values fit in 63 bits.  The overflow check
in nbd_co_receive_request() was already sane (request->from is
validated to fit in 63 bits, and request->len is 32 bits, so the
addition can't overflow 64 bits), but rewrite it in a form easier
to recognize as a typical overflow check.

Rename the variable 'description' to keep line lengths reasonable.

Suggested-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20190117193658.16413-7-eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2019-01-21 15:49:51 -06:00
Vladimir Sementsov-Ogievskiy
166cd55125 Revert "block/dirty-bitmap: Add bdrv_dirty_iter_next_area"
This reverts commit 72d10a9421.

The function is unused now.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
2019-01-15 18:26:50 -05:00
Vladimir Sementsov-Ogievskiy
a78a1a48cd dirty-bitmap: add bdrv_dirty_bitmap_next_dirty_area
The function alters bdrv_dirty_iter_next_area(), which is wrong and
less efficient (see further commit
"block/mirror: fix and improve do_sync_target_write" for description).

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2019-01-15 18:26:50 -05:00
Vladimir Sementsov-Ogievskiy
76d570dc49 dirty-bitmap: improve bdrv_dirty_bitmap_next_zero
Add bytes parameter to the function, to limit searched range.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2019-01-15 18:26:49 -05:00
Eric Blake
678ba275c7 nbd: Merge nbd_export_bitmap into nbd_export_new
We only have one caller that wants to export a bitmap name,
which it does right after creation of the export. But there is
still a brief window of time where an NBD client could see the
export but not the dirty bitmap, which a robust client would
have to interpret as meaning the entire image should be treated
as dirty.  Better is to eliminate the window entirely, by
inlining nbd_export_bitmap() into nbd_export_new(), and refusing
to create the bitmap in the first place if the requested bitmap
can't be located.

We also no longer need logic for setting a different bitmap
name compared to the bitmap being exported.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20190111194720.15671-8-eblake@redhat.com>
2019-01-14 10:09:46 -06:00
Eric Blake
3fa4c76590 nbd: Merge nbd_export_set_name into nbd_export_new
The existing NBD code had a weird split where nbd_export_new()
created an export but did not add it to the list of exported
names until a later nbd_export_set_name() came along and grabbed
a second reference on the object; later, the first call to
nbd_export_close() drops the second reference while removing
the export from the list.  This is in part because the QAPI
NbdServerRemoveNode enum documents the possibility of adding a
mode where we could do a soft disconnect: preventing new clients,
but waiting for existing clients to gracefully quit, based on
the mode used when calling nbd_export_close().

But in spite of all that, note that we never change the name of
an NBD export while it is exposed, which means it is easier to
just inline the process of setting the name as part of creating
the export.

Inline the contents of nbd_export_set_name() and
nbd_export_set_description() into the two points in an export
lifecycle where they matter, then adjust both callers to pass
the name up front.  Note that for creation, all callers pass a
non-NULL name, (passing NULL at creation was for old style
servers, but we removed support for that in commit 7f7dfe2a),
so we can add an assert and do things unconditionally; but for
cleanup, because of the dual nature of nbd_export_close(), we
still have to be careful to avoid use-after-free.  Along the
way, add a comment reminding ourselves of the potential of
adding a middle mode disconnect.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20190111194720.15671-5-eblake@redhat.com>
2019-01-14 10:09:46 -06:00
Vladimir Sementsov-Ogievskiy
757a0d05ea nbd: publish _lookup functions
These functions are used for formatting pretty trace points. We are
going to add some in block/nbd-client, so, let's publish all these
functions at once. Note, that nbd_reply_type_lookup is already
published, and constants, "named" by these functions live in
include/block/nbd.h too.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20181102151152.288399-3-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2019-01-04 17:34:58 -06:00
Alberto Garcia
2e891722c5 block: Remove flags parameter from bdrv_reopen_queue()
Now that all callers are passing all flag changes as QDict options,
the flags parameter is no longer necessary, so we can get rid of it.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-12-14 11:55:02 +01:00
Alberto Garcia
295cf237c2 block: Drop bdrv_reopen()
No one is using this function anymore, so we can safely remove it.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-12-14 11:55:02 +01:00
Alberto Garcia
6e1000a863 block: Add bdrv_reopen_set_read_only()
Most callers of bdrv_reopen() only use it to switch a BlockDriverState
between read-only and read-write, so this patch adds a new function
that does just that.

We also want to get rid of the flags parameter in the bdrv_reopen()
API, so this function sets the "read-only" option and passes the
original flags (which will then be updated in bdrv_reopen_prepare()).

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-12-14 11:55:01 +01:00
Vladimir Sementsov-Ogievskiy
3a75187fd8 block/backup: drop unused synchronization interface
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-12-14 11:52:40 +01:00
Kevin Wolf
eaa2410f1e block: Require auto-read-only for existing fallbacks
Some block drivers have traditionally changed their node to read-only
mode without asking the user. This behaviour has been marked deprecated
since 2.11, expecting users to provide an explicit read-only=on option.

Now that we have auto-read-only=on, enable these drivers to make use of
the option.

This is the only use of bdrv_set_read_only(), so we can make it a bit
more specific and turn it into a bdrv_apply_auto_read_only() that is
more convenient for drivers to use.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2018-11-05 15:09:55 +01:00
Kevin Wolf
e35bdc123a block: Add auto-read-only option
If a management application builds the block graph node by node, the
protocol layer doesn't inherit its read-only option from the format
layer any more, so it must be set explicitly.

Backing files should work on read-only storage, but at the same time, a
block job like commit should be able to reopen them read-write if they
are on read-write storage. However, without option inheritance, reopen
only changes the read-only option for the root node (typically the
format layer), but not the protocol layer, so reopening fails (the
format layer wants to get write permissions, but the protocol layer is
still read-only).

A simple workaround for the problem in the management tool would be to
open the protocol layer always read-write and to make only the format
layer read-only for backing files. However, sometimes the file is
actually stored on read-only storage and we don't know whether the image
can be opened read-write (for example, for NBD it depends on the server
we're trying to connect to). This adds an option that makes QEMU try to
open the image read-write, but allows it to degrade to a read-only mode
without returning an error.

The documentation for this option is consciously phrased in a way that
allows QEMU to switch to a better model eventually: Instead of trying
when the image is first opened, making the read-only flag dynamic and
changing it automatically whenever the first BLK_PERM_WRITE user is
attached or the last one is detached would be much more useful
behaviour.

Unfortunately, this more useful behaviour is also a lot harder to
implement, and libvirt needs a solution now before it can switch to
-blockdev, so let's start with this easier approach for now.

Instead of adding a new auto-read-only option, turning the existing
read-only into an enum (with a bool alternate for compatibility) was
considered, but it complicated the implementation to the point that it
didn't seem to be worth it.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2018-11-05 15:09:55 +01:00
Vladimir Sementsov-Ogievskiy
9c98f145df dirty-bitmaps: clean-up bitmaps loading and migration logic
This patch aims to bring the following behavior:

1. We don't load bitmaps, when started in inactive mode. It's the case
of incoming migration. In this case we wait for bitmaps migration
through migration channel (if 'dirty-bitmaps' capability is enabled) or
for invalidation (to load bitmaps from the image).

2. We don't remove persistent bitmaps on inactivation. Instead, we only
remove bitmaps after storing. This is the only way to restore bitmaps,
if we decided to resume source after [failed] migration with
'dirty-bitmaps' capability enabled (which means, that bitmaps were not
stored).

3. We load bitmaps on open and any invalidation, it's ok for all cases:
  - normal open
  - migration target invalidation with dirty-bitmaps capability
    (bitmaps are migrating through migration channel, the are not
     stored, so they should have IN_USE flag set and will be skipped
     when loading. However, it would fail if bitmaps are read-only[1])
  - migration target invalidation without dirty-bitmaps capability
    (normal load of the bitmaps, if migrated with shared storage)
  - source invalidation with dirty-bitmaps capability
    (skip because IN_USE)
  - source invalidation without dirty-bitmaps capability
    (bitmaps were dropped, reload them)

[1]: to accurately handle this, migration of read-only bitmaps is
     explicitly forbidden in this patch.

New mechanism for not storing bitmaps when migrate with dirty-bitmaps
capability is introduced: migration filed in BdrvDirtyBitmap.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: John Snow <jsnow@redhat.com>
2018-10-29 16:23:17 -04:00
John Snow
993edc0ce0 block/dirty-bitmaps: add user_locked status checker
Instead of both frozen and qmp_locked checks, wrap it into one check.
frozen implies the bitmap is split in two (for backup), and shouldn't
be modified. qmp_locked implies it's being used by another operation,
like being exported over NBD. In both cases it means we shouldn't allow
the user to modify it in any meaningful way.

Replace any usages where we check both frozen and qmp_locked with the
new check.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20181002230218.13949-2-jsnow@redhat.com
[w/edits Suggested-By: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>]
Signed-off-by: John Snow <jsnow@redhat.com>
2018-10-29 16:23:16 -04:00
Vladimir Sementsov-Ogievskiy
fa000f2f9f dirty-bitmap: make it possible to restore bitmap after merge
Add backup parameter to bdrv_merge_dirty_bitmap() to be used then with
bdrv_restore_dirty_bitmap() if it needed to restore the bitmap after
merge operation.

This is needed to implement bitmap merge transaction action in further
commit.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
2018-10-29 16:23:15 -04:00
Vladimir Sementsov-Ogievskiy
56bd662497 dirty-bitmap: rename bdrv_undo_clear_dirty_bitmap
Use more generic names to reuse the function for bitmap merge in the
following commit.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
2018-10-29 16:23:14 -04:00
Artem Pisarenko
89a603a0c8 qemu-timer: introduce timer attributes
Attributes are simple flags, associated with individual timers for their
whole lifetime.  They intended to be used to mark individual timers for
special handling when they fire.

New/init functions family in timer interface updated and refactored (new
'attribute' argument added, timer_list replaced with timer_list_group+type
combinations, comments improved to avoid info duplication).  Also existing
aio interface extended with attribute-enabled variants of functions,
which create/initialize timers.

Signed-off-by: Artem Pisarenko <artem.k.pisarenko@gmail.com>
Message-Id: <f47b81dbce734e9806f9516eba8ca588e6321c2f.1539764043.git.artem.k.pisarenko@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-10-19 13:44:03 +02:00
Denis V. Lunev
df91328ada nbd: fix NBD_FLAG_SEND_CACHE value
Commit bc37b06a5 added NBD_CMD_CACHE support, but used the wrong value
for NBD_FLAG_SEND_CACHE flag for negotiation. That commit picked bit 8,
which had already been assigned by the NBD specification to mean
NBD_FLAG_CAN_MULTI_CONN, and which was already implemented in the
Linux kernel as a part of stable userspace-kernel API since 4.10:

"bit 8, NBD_FLAG_CAN_MULTI_CONN: Indicates that the server operates
entirely without cache, or that the cache it uses is shared among all
connections to the given device. In particular, if this flag is
present, then the effects of NBD_CMD_FLUSH and NBD_CMD_FLAG_FUA
MUST be visible across all connections when the server sends its reply
to that command to the client. In the absense of this flag, clients
SHOULD NOT multiplex their commands over more than one connection to
the export.
...
bit 10, NBD_FLAG_SEND_CACHE: documents that the server understands
NBD_CMD_CACHE; however, note that server implementations exist
which support the command without advertising this bit, and
conversely that this bit does not guarantee that the command will
succeed or have an impact."

Consequences:
- a client trying to use NBD_CMD_CACHE per the NBD spec will not
see the feature as available from a qemu 3.0 server (not fatal,
clients already have to be prepared for caching to not exist)
- a client accidentally coded to the qemu 3.0 bit value instead
of following the spec may interpret NBD_CMD_CACHE as being available
when it is not (probably not fatal, the spec says the server should
gracefully fail unknown commands, and that clients of NBD_CMD_CACHE
should be prepared for failure even when the feature is advertised);
such clients are unlikely (perhaps only in unreleased Virtuozzo code),
and will disappear over time
- a client prepared to use multiple connections based on
NBD_FLAG_CAN_MULTI_CONN may cause data corruption when it assumes
that caching is consistent when in reality qemu 3.0 did not have
a consistent cache. Partially mitigated by using read-only
connections (where nothing needs to be flushed, so caching is
indeed consistent) or when using qemu-nbd with the default -e 1
(at most one client at a time); visible only when using -e 2 or
more for a writable export.

Thus the commit fixes negotiation flag in QEMU according to the
specification.

Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
CC: Valery Vdovin <valery.vdovin@acronis.com>
CC: Eric Blake <eblake@redhat.com>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: qemu-stable@nongnu.org
Message-Id: <20181004100313.4253-1-den@openvz.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
[eblake: enhance commit message, add defines for unimplemented flags]
Signed-off-by: Eric Blake <eblake@redhat.com>
2018-10-04 09:08:56 -05:00
Vladimir Sementsov-Ogievskiy
7f7dfe2a53 nbd/server: drop old-style negotiation
After the previous commit, nbd_client_new's first parameter is always
NULL. Let's drop it with all corresponding old-style negotiation code
path which is unreachable now.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20181003170228.95973-3-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[eblake: re-wrap short line]
Signed-off-by: Eric Blake <eblake@redhat.com>
2018-10-03 15:52:32 -05:00
Alberto Garcia
543770bd2e block: Allow changing 'detect-zeroes' on reopen
'detect-zeroes' is one of the basic BlockdevOptions available for all
drivers, but it's not handled by bdrv_reopen_prepare(), so any attempt
to change it results in an error:

   (qemu) qemu-io virtio0 "reopen -o detect-zeroes=on"
   Cannot change the option 'detect-zeroes'

Since there's no reason why we shouldn't allow changing it and the
implementation is simple let's just do it.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-10-01 12:51:12 +02:00
Kevin Wolf
cfe29d8294 block: Use a single global AioWait
When draining a block node, we recurse to its parent and for subtree
drains also to its children. A single AIO_WAIT_WHILE() is then used to
wait for bdrv_drain_poll() to become true, which depends on all of the
nodes we recursed to. However, if the respective child or parent becomes
quiescent and calls bdrv_wakeup(), only the AioWait of the child/parent
is checked, while AIO_WAIT_WHILE() depends on the AioWait of the
original node.

Fix this by using a single AioWait for all callers of AIO_WAIT_WHILE().

This may mean that the draining thread gets a few more unnecessary
wakeups because an unrelated operation got completed, but we already
wake it up when something _could_ have changed rather than only if it
has certainly changed.

Apart from that, drain is a slow path anyway. In theory it would be
possible to use wakeups more selectively and still correctly, but the
gains are likely not worth the additional complexity. In fact, this
patch is a nice simplification for some places in the code.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2018-09-25 15:50:15 +02:00
Kevin Wolf
486574483a aio-wait: Increase num_waiters even in home thread
Even if AIO_WAIT_WHILE() is called in the home context of the
AioContext, we still want to allow the condition to change depending on
other threads as long as they kick the AioWait. Specfically block jobs
can be running in an I/O thread and should then be able to kick a drain
in the main loop context.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
2018-09-25 15:50:15 +02:00
Kevin Wolf
34dc97b9a0 blockjob: Wake up BDS when job becomes idle
In the context of draining a BDS, the .drained_poll callback of block
jobs is called. If this returns true (i.e. there is still some activity
pending), the drain operation may call aio_poll() with blocking=true to
wait for completion.

As soon as the pending activity is completed and the job finally arrives
in a quiescent state (i.e. its coroutine either yields with busy=false
or terminates), the block job must notify the aio_poll() loop to wake
up, otherwise we get a deadlock if both are running in different
threads.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2018-09-25 15:50:15 +02:00
John Snow
cf6320df58 block/stream: add block job creation flags
Add support for taking and passing forward job creation flags.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Message-id: 20180906130225.5118-4-jsnow@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-09-25 15:31:15 +02:00
John Snow
a1999b3348 block/mirror: add block job creation flags
Add support for taking and passing forward job creation flags.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Message-id: 20180906130225.5118-3-jsnow@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-09-25 15:31:15 +02:00
John Snow
5360782d08 block/commit: add block job creation flags
Add support for taking and passing forward job creation flags.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Message-id: 20180906130225.5118-2-jsnow@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-09-25 15:31:15 +02:00
Kevin Wolf
52ebcb2682 block: Fix documentation for BDRV_REQ_MAY_UNMAP
BDRV_REQ_MAY_UNMAP in a write_zeroes request does not only allow the
driver to unmap the blocks, but it actively requests that the blocks be
unmapped afterwards if at all possible.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-07-30 15:35:37 +02:00
Fam Zheng
22931a1533 block: Use uint64_t for BdrvTrackedRequest byte fields
This matches the types used for bytes in the rest parts of block layer.
In the case of bdrv_co_truncate, new_bytes can be the image size which
probably doesn't fit in a 32 bit int.

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-07-10 16:01:52 +02:00
Fam Zheng
0b9fd3f467 block: Use BdrvChild to discard
Other I/O functions are already using a BdrvChild pointer in the API, so
make discard do the same. It makes it possible to initiate the same
permission checks before doing I/O, and much easier to share the
helper functions for this, which will be added and used by write,
truncate and copy range paths.

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-07-10 16:01:52 +02:00
Vladimir Sementsov-Ogievskiy
09d2f94846 block: add BDRV_REQ_SERIALISING flag
Serialized writes should be used in copy-on-write of backup(sync=none)
for image fleecing scheme.

We need to change an assert in bdrv_aligned_pwritev, added in
28de2dcd88. The assert may fail now, because call to
wait_serialising_requests here may become first call to it for this
request with serializing flag set. It occurs if the request is aligned
(otherwise, we should already set serializing flag before calling
bdrv_aligned_pwritev and correspondingly waited for all intersecting
requests). However, for aligned requests, we should not care about
outdating of previously read data, as there no such data. Therefore,
let's just update an assert to not care about aligned requests.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-07-10 13:10:25 +02:00
Vladimir Sementsov-Ogievskiy
67b51fb998 block: split flags in copy_range
Pass read flags and write flags separately. This is needed to handle
coming BDRV_REQ_NO_SERIALISING clearly in following patches.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-07-10 13:04:25 +02:00
Vladimir Sementsov-Ogievskiy
999658a05e block/io: fix copy_range
Here two things are fixed:

1. Architecture

On each recursion step, we go to the child of src or dst, only for one
of them. So, it's wrong to create tracked requests for both on each
step. It leads to tracked requests duplication.

2. Wait for serializing requests on write path independently of
   BDRV_REQ_NO_SERIALISING

Before commit 9ded4a0114 "backup: Use copy offloading",
BDRV_REQ_NO_SERIALISING was used for only one case: read in
copy-on-write operation during backup. Also, the flag was handled only
on read path (in bdrv_co_preadv and bdrv_aligned_preadv).

After 9ded4a0114, flag is used for not waiting serializing operations
on backup target (in same case of copy-on-write operation). This
behavior change is unsubstantiated and potentially dangerous, let's
drop it and add additional asserts and documentation.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-07-10 13:04:22 +02:00
Kevin Wolf
4be6a6d118 block: Poll after drain on attaching a node
Commit dcf94a23b1 ('block: Don't poll in parent drain callbacks')
removed polling in bdrv_child_cb_drained_begin() on the grounds that the
original bdrv_drain() already will poll and BdrvChildRole.drained_begin
calls must not cause graph changes (and therefore must not call
aio_poll() or the recursion through the graph will break.

This reasoning is correct for calls through bdrv_do_drained_begin().
However, BdrvChildRole.drained_begin is also called when a node that is
already in a drained section (i.e. bdrv_do_drained_begin() has already
returned and therefore can't poll any more) is attached to a new parent.
In this case, we must explicitly poll to have all requests completed
before the drained new child can be attached to the parent.

In bdrv_replace_child_noperm(), we know that we're not inside the
recursion of bdrv_do_drained_begin() because graph changes are not
allowed there, and bdrv_replace_child_noperm() is a graph change. The
call of BdrvChildRole.drained_begin() must therefore be followed by a
BDRV_POLL_WHILE() that waits for the completion of requests.

Reported-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-07-10 10:36:15 +02:00
Peter Maydell
1daf14ec9e Block layer patches:
- qcow2: Use worker threads for compression to improve performance of
   'qemu-img convert -W' and compressed backup jobs
 - blklogwrites: New filter driver to log write requests to an image in
   the dm-log-writes format
 - file-posix: Fix image locking during image creation
 - crypto: Fix memory leak in error path
 - Error out instead of silently truncating node names
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Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into staging

Block layer patches:

- qcow2: Use worker threads for compression to improve performance of
  'qemu-img convert -W' and compressed backup jobs
- blklogwrites: New filter driver to log write requests to an image in
  the dm-log-writes format
- file-posix: Fix image locking during image creation
- crypto: Fix memory leak in error path
- Error out instead of silently truncating node names

# gpg: Signature made Thu 05 Jul 2018 11:24:33 BST
# gpg:                using RSA key 7F09B272C88F2FD6
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>"
# Primary key fingerprint: DC3D EB15 9A9A F95D 3D74  56FE 7F09 B272 C88F 2FD6

* remotes/kevin/tags/for-upstream:
  file-posix: Unlock FD after creation
  file-posix: Fix creation locking
  block/blklogwrites: Add an option for the update interval of the log superblock
  block/blklogwrites: Add an option for appending to an old log
  block/blklogwrites: Change log_sector_size from int64_t to uint64_t
  block/crypto: Fix memory leak in create error path
  block: Don't silently truncate node names
  block: Add blklogwrites
  block: Move two block permission constants to the relevant enum
  qcow2: add compress threads
  qcow2: refactor data compression
  qemu-img: allow compressed not-in-order writes

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2018-07-05 15:53:04 +01:00
Ari Sundholm
7ae9f3f61b block: Move two block permission constants to the relevant enum
This allows using the two constants outside of block.c, which will
happen in a subsequent patch.

Signed-off-by: Ari Sundholm <ari@tuxera.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-07-05 10:29:19 +02:00
Vladimir Sementsov-Ogievskiy
92bcea40d3 block/dirty-bitmap: add bdrv_enable_dirty_bitmap_locked
Add _locked version of bdrv_enable_dirty_bitmap, to fix dirty bitmap
migration in the following patch.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20180625165745.25259-2-vsementsov@virtuozzo.com
Signed-off-by: John Snow <jsnow@redhat.com>
2018-07-04 02:12:49 -04:00
Peter Maydell
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Merge remote-tracking branch 'remotes/cody/tags/block-pull-request' into staging

# gpg: Signature made Tue 03 Jul 2018 04:42:11 BST
# gpg:                using RSA key BDBE7B27C0DE3057
# gpg: Good signature from "Jeffrey Cody <jcody@redhat.com>"
# gpg:                 aka "Jeffrey Cody <jeff@codyprime.org>"
# gpg:                 aka "Jeffrey Cody <codyprime@gmail.com>"
# Primary key fingerprint: 9957 4B4D 3474 90E7 9D98  D624 BDBE 7B27 C0DE 3057

* remotes/cody/tags/block-pull-request:
  backup: Use copy offloading
  block: Honour BDRV_REQ_NO_SERIALISING in copy range
  block: Fix parameter checking in bdrv_co_copy_range_internal

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2018-07-03 11:49:51 +01:00
Fam Zheng
dee12de893 block: Honour BDRV_REQ_NO_SERIALISING in copy range
This semantics is needed by drive-backup so implement it before using
this API there.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
Message-id: 20180703023758.14422-3-famz@redhat.com
Signed-off-by: Jeff Cody <jcody@redhat.com>
2018-07-02 23:23:45 -04:00
Eric Blake
216ee3657e nbd/client: Add x-dirty-bitmap to query bitmap from server
In order to test that the NBD server is properly advertising
dirty bitmaps, we need a bare minimum client that can request
and read the context.  Since feature freeze for 3.0 is imminent,
this is the smallest workable patch, which replaces the qemu
block status report with the results of the NBD server's dirty
bitmap (making it very easy to use 'qemu-img map --output=json'
to learn where the dirty portions are).  Note that the NBD
protocol defines a dirty section with the same bit but opposite
sense that normal "base:allocation" uses to report an allocated
section; so in qemu-img map output, "data":true corresponds to
clean, "data":false corresponds to dirty.

A more complete solution that allows dirty bitmaps to be queried
at the same time as normal block status will be required before
this addition can lose the x- prefix.  Until then, the fact that
this replaces normal status with dirty status means actions
like 'qemu-img convert' will likely misbehave due to treating
dirty regions of the file as if they are unallocated.

The next patch adds an iotest to exercise this new code.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180702191458.28741-2-eblake@redhat.com>
2018-07-02 15:27:38 -05:00
Eric Blake
583c99d393 block: Remove unused sector-based vectored I/O
We are gradually moving away from sector-based interfaces, towards
byte-based.  Now that all callers of vectored I/O have been converted
to use our preferred byte-based bdrv_co_p{read,write}v(), we can
delete the unused bdrv_co_{read,write}v().

Furthermore, this gets rid of the signature difference between the
public bdrv_co_writev() and the callback .bdrv_co_writev (the
latter still exists, because some drivers still need more work
before they are fully byte-based).

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-06-29 14:20:56 +02:00
Kevin Wolf
93f4e2ff4b file-posix: Make .bdrv_co_truncate asynchronous
This moves the code to resize an image file to the thread pool to avoid
blocking.

Creating large images with preallocation with blockdev-create is now
actually a background job instead of blocking the monitor (and most
other things) until the preallocation has completed.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2018-06-29 14:20:56 +02:00
Kevin Wolf
1bc5f09f2e block: Use tracked request for truncate
When growing an image, block drivers (especially protocol drivers) may
initialise the newly added area. I/O requests to the same area need to
wait for this initialisation to be completed so that data writes don't
get overwritten and reads don't read uninitialised data.

To avoid overhead in the fast I/O path by adding new locking in the
protocol drivers and to restrict the impact to requests that actually
touch the new area, reuse the existing tracked request infrastructure in
block/io.c and mark all discard requests as serialising.

With this change, it is safe for protocol drivers to make
.bdrv_co_truncate actually asynchronous.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2018-06-29 14:20:56 +02:00
Kevin Wolf
3d9f2d2af6 block: Move bdrv_truncate() implementation to io.c
This moves the bdrv_truncate() implementation from block.c to block/io.c
so it can have access to the tracked requests infrastructure.

This involves making refresh_total_sectors() public (in block_int.h).

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2018-06-29 14:20:56 +02:00
Kevin Wolf
061ca8a368 block: Convert .bdrv_truncate callback to coroutine_fn
bdrv_truncate() is an operation that can block (even for a quite long
time, depending on the PreallocMode) in I/O paths that shouldn't block.
Convert it to a coroutine_fn so that we have the infrastructure for
drivers to make their .bdrv_co_truncate implementation asynchronous.

This change could potentially introduce new race conditions because
bdrv_truncate() isn't necessarily executed atomically any more. Whether
this is a problem needs to be evaluated for each block driver that
supports truncate:

* file-posix/win32, gluster, iscsi, nfs, rbd, ssh, sheepdog: The
  protocol drivers are trivially safe because they don't actually yield
  yet, so there is no change in behaviour.

* copy-on-read, crypto, raw-format: Essentially just filter drivers that
  pass the request to a child node, no problem.

* qcow2: The implementation modifies metadata, so it needs to hold
  s->lock to be safe with concurrent I/O requests. In order to avoid
  double locking, this requires pulling the locking out into
  preallocate_co() and using qcow2_write_caches() instead of
  bdrv_flush().

* qed: Does a single header update, this is fine without locking.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2018-06-29 14:20:56 +02:00
Nishanth Aravamudan
ed6e216171 linux-aio: properly bubble up errors from initialization
laio_init() can fail for a couple of reasons, which will lead to a NULL
pointer dereference in laio_attach_aio_context().

To solve this, add a aio_setup_linux_aio() function which is called
early in raw_open_common. If this fails, propagate the error up. The
signature of aio_get_linux_aio() was not modified, because it seems
preferable to return the actual errno from the possible failing
initialization calls.

Additionally, when the AioContext changes, we need to associate a
LinuxAioState with the new AioContext. Use the bdrv_attach_aio_context
callback and call the new aio_setup_linux_aio(), which will allocate a
new AioContext if needed, and return errors on failures. If it fails for
any reason, fallback to threaded AIO with an error message, as the
device is already in-use by the guest.

Add an assert that aio_get_linux_aio() cannot return NULL.

Signed-off-by: Nishanth Aravamudan <naravamudan@digitalocean.com>
Message-id: 20180622193700.6523-1-naravamudan@digitalocean.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2018-06-27 13:06:34 +01:00
Vladimir Sementsov-Ogievskiy
bc37b06a5c nbd/server: introduce NBD_CMD_CACHE
Handle nbd CACHE command. Just do read, without sending read data back.
Cache mechanism should be done by exported node driver chain.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20180413143156.11409-1-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[eblake: fix two missing case labels in switch statements]
Signed-off-by: Eric Blake <eblake@redhat.com>
2018-06-21 09:41:39 -05:00
Vladimir Sementsov-Ogievskiy
3d068aff16 nbd/server: implement dirty bitmap export
Handle a new NBD meta namespace: "qemu", and corresponding queries:
"qemu:dirty-bitmap:<export bitmap name>".

With the new metadata context negotiated, BLOCK_STATUS query will reply
with dirty-bitmap data, converted to extents. The new public function
nbd_export_bitmap selects which bitmap to export. For now, only one bitmap
may be exported.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20180609151758.17343-5-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[eblake: wording tweaks, minor cleanups, additional tracing]
Signed-off-by: Eric Blake <eblake@redhat.com>
2018-06-21 09:23:58 -05:00
Max Reitz
481debaa32 block/mirror: Add copy mode QAPI interface
This patch allows the user to specify whether to use active or only
background mode for mirror block jobs.  Currently, this setting will
remain constant for the duration of the entire block job.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20180613181823.13618-14-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-06-18 17:05:16 +02:00
Max Reitz
72d10a9421 block/dirty-bitmap: Add bdrv_dirty_iter_next_area
This new function allows to look for a consecutively dirty area in a
dirty bitmap.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 20180613181823.13618-10-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-06-18 17:04:57 +02:00
Kevin Wolf
0f12264e7a block: Allow graph changes in bdrv_drain_all_begin/end sections
bdrv_drain_all_*() used bdrv_next() to iterate over all root nodes and
did a subtree drain for each of them. This works fine as long as the
graph is static, but sadly, reality looks different.

If the graph changes so that root nodes are added or removed, we would
have to compensate for this. bdrv_next() returns each root node only
once even if it's the root node for multiple BlockBackends or for a
monitor-owned block driver tree, which would only complicate things.

The much easier and more obviously correct way is to fundamentally
change the way the functions work: Iterate over all BlockDriverStates,
no matter who owns them, and drain them individually. Compensation is
only necessary when a new BDS is created inside a drain_all section.
Removal of a BDS doesn't require any action because it's gone afterwards
anyway.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-06-18 15:03:25 +02:00
Kevin Wolf
6cd5c9d7b2 block: ignore_bds_parents parameter for drain functions
In the future, bdrv_drained_all_begin/end() will drain all invidiual
nodes separately rather than whole subtrees. This means that we don't
want to propagate the drain to all parents any more: If the parent is a
BDS, it will already be drained separately. Recursing to all parents is
unnecessary work and would make it an O(n²) operation.

Prepare the drain function for the changed drain_all by adding an
ignore_bds_parents parameter to the internal implementation that
prevents the propagation of the drain to BDS parents. We still (have to)
propagate it to non-BDS parents like BlockBackends or Jobs because those
are not drained separately.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-06-18 15:03:25 +02:00
Kevin Wolf
4d22bbf4ef block: Allow AIO_WAIT_WHILE with NULL ctx
bdrv_drain_all() wants to have a single polling loop for draining the
in-flight requests of all nodes. This means that the AIO_WAIT_WHILE()
condition relies on activity in multiple AioContexts, which is polled
from the mainloop context. We must therefore call AIO_WAIT_WHILE() from
the mainloop thread and use the AioWait notification mechanism.

Just randomly picking the AioContext of any non-mainloop thread would
work, but instead of bothering to find such a context in the caller, we
can just as well accept NULL for ctx.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-06-18 15:03:25 +02:00
Kevin Wolf
dcf94a23b1 block: Don't poll in parent drain callbacks
bdrv_do_drained_begin() is only safe if we have a single
BDRV_POLL_WHILE() after quiescing all affected nodes. We cannot allow
that parent callbacks introduce a nested polling loop that could cause
graph changes while we're traversing the graph.

Split off bdrv_do_drained_begin_quiesce(), which only quiesces a single
node without waiting for its requests to complete. These requests will
be waited for in the BDRV_POLL_WHILE() call down the call chain.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-06-18 15:03:25 +02:00
Kevin Wolf
fe4f0614ef block: Drain recursively with a single BDRV_POLL_WHILE()
Anything can happen inside BDRV_POLL_WHILE(), including graph
changes that may interfere with its callers (e.g. child list iteration
in recursive callers of bdrv_do_drained_begin).

Switch to a single BDRV_POLL_WHILE() call for the whole subtree at the
end of bdrv_do_drained_begin() to avoid such effects. The recursion
happens now inside the loop condition. As the graph can only change
between bdrv_drain_poll() calls, but not inside of it, doing the
recursion here is safe.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-06-18 15:03:25 +02:00
Kevin Wolf
89bd030533 block: Really pause block jobs on drain
We already requested that block jobs be paused in .bdrv_drained_begin,
but no guarantee was made that the job was actually inactive at the
point where bdrv_drained_begin() returned.

This introduces a new callback BdrvChildRole.bdrv_drained_poll() and
uses it to make bdrv_drain_poll() consider block jobs using the node to
be drained.

For the test case to work as expected, we have to switch from
block_job_sleep_ns() to qemu_co_sleep_ns() so that the test job is even
considered active and must be waited for when draining the node.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-06-18 15:03:25 +02:00
Kevin Wolf
1cc8e54ada block: Avoid unnecessary aio_poll() in AIO_WAIT_WHILE()
Commit 91af091f92 added an additional aio_poll() to BDRV_POLL_WHILE()
in order to make sure that all pending BHs are executed on drain. This
was the wrong place to make the fix, as it is useless overhead for all
other users of the macro and unnecessarily complicates the mechanism.

This patch effectively reverts said commit (the context has changed a
bit and the code has moved to AIO_WAIT_WHILE()) and instead polls in the
loop condition for drain.

The effect is probably hard to measure in any real-world use case
because actual I/O will dominate, but if I run only the initialisation
part of 'qemu-img convert' where it calls bdrv_block_status() for the
whole image to find out how much data there is copy, this phase actually
needs only roughly half the time after this patch.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2018-06-18 15:03:25 +02:00
Markus Armbruster
af91062ee1 block: Factor out qobject_input_visitor_new_flat_confused()
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-06-15 14:49:44 +02:00
Markus Armbruster
e5af0da1dc block: Fix -blockdev for certain non-string scalars
Configuration flows through the block subsystem in a rather peculiar
way.  Configuration made with -drive enters it as QemuOpts.
Configuration made with -blockdev / blockdev-add enters it as QAPI
type BlockdevOptions.  The block subsystem uses QDict, QemuOpts and
QAPI types internally.  The precise flow is next to impossible to
explain (I tried for this commit message, but gave up after wasting
several hours).  What I can explain is a flaw in the BlockDriver
interface that leads to this bug:

    $ qemu-system-x86_64 -blockdev node-name=n1,driver=nfs,server.type=inet,server.host=localhost,path=/foo/bar,user=1234
    qemu-system-x86_64: -blockdev node-name=n1,driver=nfs,server.type=inet,server.host=localhost,path=/foo/bar,user=1234: Internal error: parameter user invalid

QMP blockdev-add is broken the same way.

Here's what happens.  The block layer passes configuration represented
as flat QDict (with dotted keys) to BlockDriver methods
.bdrv_file_open().  The QDict's members are typed according to the
QAPI schema.

nfs_file_open() converts it to QAPI type BlockdevOptionsNfs, with
qdict_crumple() and a qobject input visitor.

This visitor comes in two flavors.  The plain flavor requires scalars
to be typed according to the QAPI schema.  That's the case here.  The
keyval flavor requires string scalars.  That's not the case here.
nfs_file_open() uses the latter, and promptly falls apart for members
@user, @group, @tcp-syn-count, @readahead-size, @page-cache-size,
@debug.

Switching to the plain flavor would fix -blockdev, but break -drive,
because there the scalars arrive in nfs_file_open() as strings.

The proper fix would be to replace the QDict by QAPI type
BlockdevOptions in the BlockDriver interface.  Sadly, that's beyond my
reach right now.

Next best would be to fix the block layer to always pass correctly
typed QDicts to the BlockDriver methods.  Also beyond my reach.

What I can do is throw another hack onto the pile: have
nfs_file_open() convert all members to string, so use of the keyval
flavor actually works, by replacing qdict_crumple() by new function
qdict_crumple_for_keyval_qiv().

The pattern "pass result of qdict_crumple() to
qobject_input_visitor_new_keyval()" occurs several times more:

* qemu_rbd_open()

  Same issue as nfs_file_open(), but since BlockdevOptionsRbd has only
  string members, its only a latent bug.  Fix it anyway.

* parallels_co_create_opts(), qcow_co_create_opts(),
  qcow2_co_create_opts(), bdrv_qed_co_create_opts(),
  sd_co_create_opts(), vhdx_co_create_opts(), vpc_co_create_opts()

  These work, because they create the QDict with
  qemu_opts_to_qdict_filtered(), which creates only string scalars.
  The function sports a TODO comment asking for better typing; that's
  going to be fun.  Use qdict_crumple_for_keyval_qiv() to be safe.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-06-15 14:49:44 +02:00
Max Reitz
609f45ea95 block: Add block-specific QDict header
There are numerous QDict functions that have been introduced for and are
used only by the block layer.  Move their declarations into an own
header file to reflect that.

While qdict_extract_subqdict() is in fact used outside of the block
layer (in util/qemu-config.c), it is still a function related very
closely to how the block layer works with nested QDicts, namely by
sometimes flattening them.  Therefore, its declaration is put into this
header as well and util/qemu-config.c includes it with a comment stating
exactly which function it needs.

Suggested-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20180509165530.29561-7-mreitz@redhat.com>
[Copyright note tweaked, superfluous includes dropped]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-06-15 14:49:44 +02:00
Vladimir Sementsov-Ogievskiy
b598e531f1 qapi: add x-block-dirty-bitmap-merge
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Message-id: 20180606182449.1607-5-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2018-06-11 14:53:32 -04:00
Paolo Bonzini
ab41fc4853 block: remove bdrv_dirty_bitmap_make_anon
All this function is doing will be repeated by
bdrv_do_release_matching_dirty_bitmap_locked, except
resetting bm->persistent.  But even that does not matter
because the bitmap will be freed.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20180323164254.26487-1-pbonzini@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
2018-06-11 14:53:31 -04:00
Max Reitz
cc02214097 block: Make bdrv_is_writable() public
This is a useful function for the whole block layer, so make it public.
At the same time, users outside of block.c probably do not need to make
use of the reopen functionality, so rename the current function to
bdrv_is_writable_after_reopen() create a new bdrv_is_writable() function
that just passes NULL to it for the reopen queue.

Cc: qemu-stable@nongnu.org
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20180606193702.7113-2-mreitz@redhat.com
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-06-11 16:18:45 +02:00
Max Reitz
d1402b5026 block: Add Error parameter to bdrv_amend_options
Looking at the qcow2 code that is riddled with error_report() calls,
this is really how it should have been from the start.

Along the way, turn the target_version/current_version comparisons at
the beginning of qcow2_downgrade() into assertions (the caller has to
make sure these conditions are met), and rephrase the error message on
using compat=1.1 to get refcount widths other than 16 bits.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20180509210023.20283-3-mreitz@redhat.com
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-06-11 16:18:45 +02:00
Fam Zheng
1efad060d7 file-posix: Implement bdrv_co_copy_range
With copy_file_range(2), we can implement the bdrv_co_copy_range
semantics.

Signed-off-by: Fam Zheng <famz@redhat.com>
Message-id: 20180601092648.24614-6-famz@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2018-06-01 14:41:48 +01:00
Fam Zheng
fcc6767836 block: Introduce API for copy offloading
Introduce the bdrv_co_copy_range() API for copy offloading.  Block
drivers implementing this API support efficient copy operations that
avoid reading each block from the source device and writing it to the
destination devices.  Examples of copy offload primitives are SCSI
EXTENDED COPY and Linux copy_file_range(2).

Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20180601092648.24614-2-famz@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2018-06-01 14:41:47 +01:00
Kevin Wolf
9f6bb4c004 blockjob: Remove BlockJob.driver
BlockJob.driver is redundant with Job.driver and only used in very few
places any more. Remove it.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-05-23 14:30:51 +02:00
Kevin Wolf
30a5c887bf job: Move progress fields to Job
BlockJob has fields .offset and .len, which are actually misnomers today
because they are no longer tied to block device sizes, but just progress
counters. As such they make a lot of sense in generic Jobs.

This patch moves the fields to Job and renames them to .progress_current
and .progress_total to describe their function better.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2018-05-23 14:30:51 +02:00
Kevin Wolf
2e1795b581 job: Add job_transition_to_ready()
The transition to the READY state was still performed in the BlockJob
layer, in the same function that sent the BLOCK_JOB_READY QMP event.

This patch brings the state transition to the Job layer and implements
the QMP event using a notifier called from the Job layer, like we
already do for other events related to state transitions.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2018-05-23 14:30:51 +02:00
Kevin Wolf
df956ae201 job: Add job_is_ready()
Instead of having a 'bool ready' in BlockJob, add a function that
derives its value from the job status.

At the same time, this fixes the behaviour to match what the QAPI
documentation promises for query-block-job: 'true if the job may be
completed'. When the ready flag was introduced in commit ef6dbf1e46,
the flag never had to be reset to match the description because after
being ready, the jobs would immediately complete and disappear.

Job transactions and manual job finalisation were introduced only later.
With these changes, jobs may stay around even after having completed
(and they are not ready to be completed a second time), however their
patches forgot to reset the ready flag.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2018-05-23 14:30:51 +02:00
Kevin Wolf
5f9a6a08e8 job: Add job_dismiss()
This moves block_job_dismiss() to the Job layer.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2018-05-23 14:30:51 +02:00
Kevin Wolf
198c49cc8d job: Add job_yield()
This moves block_job_yield() to the Job layer.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2018-05-23 14:30:51 +02:00
Kevin Wolf
3d70ff53b6 job: Move completion and cancellation to Job
This moves the top-level job completion and cancellation functions from
BlockJob to Job.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-05-23 14:30:51 +02:00
Kevin Wolf
7eaa8fb57d job: Move transactions to Job
This moves the logic that implements job transactions from BlockJob to
Job.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2018-05-23 14:30:51 +02:00
Kevin Wolf
62c9e4162a job: Switch transactions to JobTxn
This doesn't actually move any transaction code to Job yet, but it
renames the type for transactions from BlockJobTxn to JobTxn and makes
them contain Jobs rather than BlockJobs

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2018-05-23 14:30:50 +02:00
Kevin Wolf
3453d97243 job: Move .complete callback to Job
This moves the .complete callback that tells a READY job to complete
from BlockJobDriver to JobDriver. The wrapper function job_complete()
doesn't require anything block job specific any more and can be moved
to Job.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2018-05-23 14:30:50 +02:00
Kevin Wolf
b69f777dd9 job: Add job_drain()
block_job_drain() contains a blk_drain() call which cannot be moved to
Job, so add a new JobDriver callback JobDriver.drain which has a common
implementation for all BlockJobs. In addition to this we keep the
existing BlockJobDriver.drain callback that is called by the common
drain implementation for all block jobs.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2018-05-23 14:30:50 +02:00
Kevin Wolf
004e95df98 job: Convert block_job_cancel_async() to Job
block_job_cancel_async() did two things that were still block job
specific:

* Setting job->force. This field makes sense on the Job level, so we can
  just move it. While at it, rename it to job->force_cancel to make its
  purpose more obvious.

* Resetting the I/O status. This can't be moved because generic Jobs
  don't have an I/O status. What the function really implements is a
  user resume, except without entering the coroutine. Consequently, it
  makes sense to call the .user_resume driver callback here which
  already resets the I/O status.

  The old block_job_cancel_async() has two separate if statements that
  check job->iostatus != BLOCK_DEVICE_IO_STATUS_OK and job->user_paused.
  However, the former condition always implies the latter (as is
  asserted in block_job_iostatus_reset()), so changing the explicit call
  of block_job_iostatus_reset() on the former condition with the
  .user_resume callback on the latter condition is equivalent and
  doesn't need to access any BlockJob specific state.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2018-05-23 14:30:50 +02:00
Kevin Wolf
4ad351819b job: Move single job finalisation to Job
This moves the finalisation of a single job from BlockJob to Job.

Some part of this code depends on job transactions, and job transactions
call this code, we introduce some temporary calls from Job functions to
BlockJob ones. This will be fixed once transactions move to Job, too.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2018-05-23 14:30:50 +02:00
Kevin Wolf
139a9f020d job: Add job_event_*()
Go through the Job layer in order to send QMP events. For the moment,
these functions only call a notifier in the BlockJob layer that sends
the existing commands.

This uses notifiers rather than JobDriver callbacks because internal
users of jobs won't receive QMP events, but might still be interested
in getting notified for the events.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2018-05-23 14:30:50 +02:00
Kevin Wolf
bb02b65c7d job: Move BlockJobCreateFlags to Job
This renames the BlockJobCreateFlags constants, moves a few JOB_INTERNAL
checks to job_create() and the auto_{finalize,dismiss} fields from
BlockJob to Job.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2018-05-23 14:30:50 +02:00
Kevin Wolf
dbe5e6c1f7 job: Replace BlockJob.completed with job_is_completed()
Since we introduced an explicit status to block job, BlockJob.completed
is redundant because it can be derived from the status. Remove the field
from BlockJob and add a function to derive it from the status at the Job
level.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
2018-05-23 14:30:50 +02:00
Kevin Wolf
b15de82867 job: Move pause/resume functions to Job
While we already moved the state related to job pausing to Job, the
functions to do were still BlockJob only. This commit moves them over to
Job.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
2018-05-23 14:30:50 +02:00
Kevin Wolf
5d43e86e11 job: Add job_sleep_ns()
There is nothing block layer specific about block_job_sleep_ns(), so
move the function to Job.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2018-05-23 14:30:50 +02:00
Kevin Wolf
da01ff7f38 job: Move coroutine and related code to Job
This commit moves some core functions for dealing with the job coroutine
from BlockJob to Job. This includes primarily entering the coroutine
(both for the first and reentering) and yielding explicitly and at pause
points.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
2018-05-23 14:30:50 +02:00
Kevin Wolf
1908a5590c job: Move defer_to_main_loop to Job
Move the defer_to_main_loop functionality from BlockJob to Job.

The code can be simplified because we can use job->aio_context in
job_defer_to_main_loop_bh() now, instead of having to access the
BlockDriverState.

Probably taking the data->aio_context lock in addition was already
unnecessary in the old code because we didn't actually make use of
anything protected by the old AioContext except getting the new
AioContext, in case it changed between scheduling the BH and running it.
But it's certainly unnecessary now that the BDS isn't accessed at all
any more.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
2018-05-23 14:30:50 +02:00
Kevin Wolf
daa7f2f946 job: Move cancelled to Job
We cannot yet move the whole logic around job cancelling to Job because
it depends on quite a few other things that are still only in BlockJob,
but we can move the cancelled field at least.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
2018-05-23 14:30:49 +02:00
Kevin Wolf
80fa2c756b job: Add reference counting
This moves reference counting from BlockJob to Job.

In order to keep calling the BlockJob cleanup code when the job is
deleted via job_unref(), introduce a new JobDriver.free callback. Every
block job must use block_job_free() for this callback, this is asserted
in block_job_create().

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
2018-05-23 14:30:49 +02:00
Kevin Wolf
a50c2ab858 job: Move state transitions to Job
This moves BlockJob.status and the closely related functions
(block_)job_state_transition() and (block_)job_apply_verb to Job. The
two QAPI enums are renamed to JobStatus and JobVerb.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2018-05-23 14:30:49 +02:00
Kevin Wolf
e7c1d78bbd job: Maintain a list of all jobs
This moves the job list from BlockJob to Job. Now we can check for
duplicate IDs in job_create().

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
2018-05-23 14:30:49 +02:00
Kevin Wolf
252291eaea job: Add JobDriver.job_type
This moves the job_type field from BlockJobDriver to JobDriver.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
2018-05-23 14:30:49 +02:00
Kevin Wolf
8e4c87000f job: Rename BlockJobType into JobType
QAPI types aren't externally visible, so we can rename them without
causing problems. Before we add a job type to Job, rename the enum
so it can be used for more than just block jobs.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
2018-05-23 14:30:49 +02:00
Kevin Wolf
33e9e9bd62 job: Create Job, JobDriver and job_create()
This is the first step towards creating an infrastructure for generic
background jobs that aren't tied to a block device. For now, Job only
stores its ID and JobDriver, the rest stays in BlockJob.

The following patches will move over more parts of BlockJob to Job if
they are meaningful outside the context of a block job.

BlockJob.driver is now redundant, but this patch leaves it around to
avoid unnecessary churn. The next patches will get rid of almost all of
its uses anyway so that it can be removed later with much less churn.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
2018-05-23 14:30:49 +02:00
Jie Wang
cd0a6d2b2c iothread: fix epollfd leak in the process of delIOThread
When we call addIOThread, the epollfd created in aio_context_setup,
but not close it in the process of delIOThread, so the epollfd will leak.

Reorder the code in aio_epoll_disable and reuse it.

Signed-off-by: Jie Wang <wangjie88@huawei.com>
Message-Id: <1526517763-11108-1-git-send-email-wangjie88@huawei.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
[Mention change to aio_epoll_disable in commit message. - Fam]
Signed-off-by: Fam Zheng <famz@redhat.com>
2018-05-18 17:09:54 +08:00
Max Reitz
c1e3489dfa block: Document BDRV_REQ_WRITE_UNCHANGED support
Add BDRV_REQ_WRITE_UNCHANGED to the list of flags honored during pwrite
and pwrite_zeroes, and also add a note on when you absolutely need to
support it.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20180502140359.18222-1-mreitz@redhat.com
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-05-15 16:15:21 +02:00
Max Reitz
c6035964f8 block: Add BDRV_REQ_WRITE_UNCHANGED flag
This flag signifies that a write request will not change the visible
disk content.  With this flag set, it is sufficient to have the
BLK_PERM_WRITE_UNCHANGED permission instead of BLK_PERM_WRITE.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20180421132929.21610-4-mreitz@redhat.com
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-05-15 16:15:21 +02:00
Max Reitz
24b7c538fe block: BLK_PERM_WRITE includes ..._UNCHANGED
Currently we never actually check whether the WRITE_UNCHANGED
permission has been taken for unchanging writes.  But the one check that
is commented out checks both WRITE and WRITE_UNCHANGED; and considering
that WRITE_UNCHANGED is already documented as being weaker than WRITE,
we should probably explicitly document WRITE to include WRITE_UNCHANGED.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20180421132929.21610-3-mreitz@redhat.com
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-05-15 16:15:21 +02:00
Kevin Wolf
bd21935b50 blockjob: Add block_job_driver()
The backup block job directly accesses the driver field in BlockJob. Add
a wrapper for getting it.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
2018-05-15 16:11:50 +02:00
Kevin Wolf
dee81d5111 blockjob: Introduce block_job_ratelimit_get_delay()
This gets us rid of more direct accesses to BlockJob fields from the
job drivers.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
2018-05-15 16:11:50 +02:00
Kevin Wolf
18bb69287e blockjob: Implement block_job_set_speed() centrally
All block job drivers support .set_speed and all of them duplicate the
same code to implement it. Move that code to blockjob.c and remove the
now useless callback.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
2018-05-15 16:11:50 +02:00
Kevin Wolf
f05fee508f blockjob: Move RateLimit to BlockJob
Every block job has a RateLimit, and they all do the exact same thing
with it, so it should be common infrastructure. Move the struct field
for a start.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
2018-05-15 16:11:50 +02:00
Kevin Wolf
05df8a6a2b blockjob: Wrappers for progress counter access
Block job drivers are not expected to mess with the internals of the
BlockJob object, so provide wrapper functions for one of the cases where
they still do it: Updating the progress counter.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
2018-05-15 16:11:49 +02:00
Eric Blake
e18a58b4e3 block: Merge .bdrv_co_writev{,_flags} in drivers
We have too many driver callback interfaces; simplify the mess
somewhat by merging the flags parameter of .bdrv_co_writev_flags()
into .bdrv_co_writev().  Note that as long as a driver doesn't set
.supported_write_flags, the flags argument will be 0 and behavior is
identical.  Also note that the public function bdrv_co_writev() still
lacks a flags argument; so the driver signature is thus intentionally
slightly different.  But that's not the end of the world, nor the first
time that the driver interface differs slightly from the public
interface.

Ideally, we should be rewriting all of these drivers to use modern
byte-based interfaces.  But that's a more invasive patch to write
and audit, compared to the simplification done here.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-05-15 16:11:41 +02:00
Eric Blake
edfab6a08b block: Drop last of the sector-based aio callbacks
We are gradually moving away from sector-based interfaces, towards
byte-based.  Now that all drivers with aio callbacks are using the
byte-based interfaces, we can remove the sector-based versions.

Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-05-15 16:11:41 +02:00
Eric Blake
de7056a3f9 file-win32: Switch to byte-based callbacks
We are gradually moving away from sector-based interfaces, towards
byte-based.  Make the change for the last few sector-based callbacks
in the file-win32 driver.

Note that the driver was already using byte-based calls for
performing actual I/O, so this just gets rid of a round trip
of scaling; however, as I don't know if Windows is tolerant of
non-sector AIO operations, I went with the conservative approach
of modifying .bdrv_refresh_limits to override the block layer
defaults back to the pre-patch value of 512.

Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-05-15 16:11:41 +02:00
Eric Blake
e31f6864a6 block: Support byte-based aio callbacks
We are gradually moving away from sector-based interfaces, towards
byte-based.  Add new sector-based aio callbacks for read and write,
to match the fact that bdrv_aio_pdiscard is already byte-based.

Ideally, drivers should be converted to use coroutine callbacks
rather than aio; but that is not quite as trivial (and if we were
to do that conversion, the null-aio driver would disappear), so for
the short term, converting the signature but keeping things with
aio is easier.  However, we CAN declare that a driver that uses
the byte-based aio interfaces now defaults to byte-based
operations, and must explicitly provide a refresh_limits override
to stick with larger alignments (making the alignment issues more
obvious directly in the drivers touched in the next few patches).

Once all drivers are converted, the sector-based aio callbacks will
be removed; in the meantime, a FIXME comment is added due to a
slight inefficiency that will be touched up as part of that later
cleanup.

Simplify some instances of 'bs->drv' into 'drv' while touching this,
since the local variable already exists to reduce typing.

Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-05-15 16:11:41 +02:00
Stefan Hajnoczi
23d702d898 blockjob: drop block_job_pause/resume_all()
Commit 8119334918 ("block: Don't
block_job_pause_all() in bdrv_drain_all()") removed the only callers of
block_job_pause/resume_all().

Pausing and resuming now happens in child_job_drained_begin/end() so
it's no longer necessary to globally pause/resume jobs.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20180424085240.5798-1-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2018-05-10 10:41:12 +01:00
Fabiano Rosas
1e486cf30a include/block/block_int: Document protocol related functions
Clarify that:

- for protocols the brdv_file_open function is used instead
of bdrv_open;

- when protocol_name is set, a driver should expect
to be given only a filename and no other options.

Signed-off-by: Fabiano Rosas <farosas@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-03-26 12:16:00 +02:00
Vladimir Sementsov-Ogievskiy
b741ae7417 block/accounting: introduce latency histogram
Introduce latency histogram statics for block devices.
For each accounted operation type, the latency region [0, +inf) is
divided into subregions by several points. Then, calculate
hits for each subregion.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20180309165212.97144-2-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2018-03-19 14:58:37 -05:00
Liang Li
b76e4458b1 block/mirror: change the semantic of 'force' of block-job-cancel
When doing drive mirror to a low speed shared storage, if there was heavy
BLK IO write workload in VM after the 'ready' event, drive mirror block job
can't be canceled immediately, it would keep running until the heavy BLK IO
workload stopped in the VM.

Libvirt depends on the current block-job-cancel semantics, which is that
when used without a flag after the 'ready' event, the command blocks
until data is in sync.  However, these semantics are awkward in other
situations, for example, people may use drive mirror for realtime
backups while still wanting to use block live migration.  Libvirt cannot
start a block live migration while another drive mirror is in progress,
but the user would rather abandon the backup attempt as broken and
proceed with the live migration than be stuck waiting for the current
drive mirror backup to finish.

The drive-mirror command already includes a 'force' flag, which libvirt
does not use, although it documented the flag as only being useful to
quit a job which is paused.  However, since quitting a paused job has
the same effect as abandoning a backup in a non-paused job (namely, the
destination file is not in sync, and the command completes immediately),
we can just improve the documentation to make the force flag obviously
useful.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Jeff Cody <jcody@redhat.com>
Cc: Kevin Wolf <kwolf@redhat.com>
Cc: Max Reitz <mreitz@redhat.com>
Cc: Eric Blake <eblake@redhat.com>
Cc: John Snow <jsnow@redhat.com>
Reported-by: Huaitong Han <huanhuaitong@didichuxing.com>
Signed-off-by: Huaitong Han <huanhuaitong@didichuxing.com>
Signed-off-by: Liang Li <liliangleo@didichuxing.com>
Signed-off-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-03-19 12:01:39 +01:00
John Snow
11b61fbc0d blockjobs: add block-job-finalize
Instead of automatically transitioning from PENDING to CONCLUDED, gate
the .prepare() and .commit() phases behind an explicit acknowledgement
provided by the QMP monitor if auto_finalize = false has been requested.

This allows us to perform graph changes in prepare and/or commit so that
graph changes do not occur autonomously without knowledge of the
controlling management layer.

Transactions that have reached the "PENDING" state together can all be
moved to invoke their finalization methods by issuing block_job_finalize
to any one job in the transaction.

Jobs in a transaction with mixed job->auto_finalize settings will all
remain stuck in the "PENDING" state, as if the entire transaction was
specified with auto_finalize = false. Jobs that specified
auto_finalize = true, however, will still not emit the PENDING event.

Signed-off-by: John Snow <jsnow@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-03-19 12:01:24 +01:00
John Snow
5f241594c4 blockjobs: add PENDING status and event
For jobs utilizing the new manual workflow, we intend to prohibit
them from modifying the block graph until the management layer provides
an explicit ACK via block-job-finalize to move the process forward.

To distinguish this runstate from "ready" or "waiting," we add a new
"pending" event and status.

For now, the transition from PENDING to CONCLUDED/ABORTING is automatic,
but a future commit will add the explicit block-job-finalize step.

Transitions:
Waiting -> Pending:   Normal transition.
Pending -> Concluded: Normal transition.
Pending -> Aborting:  Late transactional failures and cancellations.

Removed Transitions:
Waiting -> Concluded: Jobs must go to PENDING first.

Verbs:
Cancel: Can be applied to a pending job.

             +---------+
             |UNDEFINED|
             +--+------+
                |
             +--v----+
   +---------+CREATED+-----------------+
   |         +--+----+                 |
   |            |                      |
   |         +--+----+     +------+    |
   +---------+RUNNING<----->PAUSED|    |
   |         +--+-+--+     +------+    |
   |            | |                    |
   |            | +------------------+ |
   |            |                    | |
   |         +--v--+       +-------+ | |
   +---------+READY<------->STANDBY| | |
   |         +--+--+       +-------+ | |
   |            |                    | |
   |         +--v----+               | |
   +---------+WAITING<---------------+ |
   |         +--+----+                 |
   |            |                      |
   |         +--v----+                 |
   +---------+PENDING|                 |
   |         +--+----+                 |
   |            |                      |
+--v-----+   +--v------+               |
|ABORTING+--->CONCLUDED|               |
+--------+   +--+------+               |
                |                      |
             +--v-+                    |
             |NULL<--------------------+
             +----+

Signed-off-by: John Snow <jsnow@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-03-19 12:01:24 +01:00
John Snow
2da4617a54 blockjobs: add prepare callback
Some jobs upon finalization may need to perform some work that can
still fail. If these jobs are part of a transaction, it's important
that these callbacks fail the entire transaction.

We allow for a new callback in addition to commit/abort/clean that
allows us the opportunity to have fairly late-breaking failures
in the transactional process.

The expected flow is:

- All jobs in a transaction converge to the PENDING state,
  added in a forthcoming commit.
- Upon being finalized, either automatically or explicitly
  by the user, jobs prepare to complete.
- If any job fails preparation, all jobs call .abort.
- Otherwise, they succeed and call .commit.

Signed-off-by: John Snow <jsnow@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-03-19 12:01:24 +01:00
John Snow
75f710599f blockjobs: add block_job_dismiss
For jobs that have reached their CONCLUDED state, prior to having their
last reference put down (meaning jobs that have completed successfully,
unsuccessfully, or have been canceled), allow the user to dismiss the
job's lingering status report via block-job-dismiss.

This gives management APIs the chance to conclusively determine if a job
failed or succeeded, even if the event broadcast was missed.

Note: block_job_do_dismiss and block_job_decommission happen to do
exactly the same thing, but they're called from different semantic
contexts, so both aliases are kept to improve readability.

Note 2: Don't worry about the 0x04 flag definition for AUTO_DISMISS, she
has a friend coming in a future patch to fill the hole where 0x02 is.

Verbs:
Dismiss: operates on CONCLUDED jobs only.
Signed-off-by: John Snow <jsnow@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-03-19 12:01:24 +01:00
John Snow
0ec4dfb8d6 blockjobs: add block_job_verb permission table
Which commands ("verbs") are appropriate for jobs in which state is
also somewhat burdensome to keep track of.

As of this commit, it looks rather useless, but begins to look more
interesting the more states we add to the STM table.

A recurring theme is that no verb will apply to an 'undefined' job.

Further, it's not presently possible to restrict the "pause" or "resume"
verbs any more than they are in this commit because of the asynchronous
nature of how jobs enter the PAUSED state; justifications for some
seemingly erroneous applications are given below.

=====
Verbs
=====

Cancel:    Any state except undefined.
Pause:     Any state except undefined;
           'created': Requests that the job pauses as it starts.
           'running': Normal usage. (PAUSED)
           'paused':  The job may be paused for internal reasons,
                      but the user may wish to force an indefinite
                      user-pause, so this is allowed.
           'ready':   Normal usage. (STANDBY)
           'standby': Same logic as above.
Resume:    Any state except undefined;
           'created': Will lift a user's pause-on-start request.
           'running': Will lift a pause request before it takes effect.
           'paused':  Normal usage.
           'ready':   Will lift a pause request before it takes effect.
           'standby': Normal usage.
Set-speed: Any state except undefined, though ready may not be meaningful.
Complete:  Only a 'ready' job may accept a complete request.

=======
Changes
=======

(1)

To facilitate "nice" error checking, all five major block-job verb
interfaces in blockjob.c now support an errp parameter:

- block_job_user_cancel is added as a new interface.
- block_job_user_pause gains an errp paramter
- block_job_user_resume gains an errp parameter
- block_job_set_speed already had an errp parameter.
- block_job_complete already had an errp parameter.

(2)

block-job-pause and block-job-resume will no longer no-op when trying
to pause an already paused job, or trying to resume a job that isn't
paused. These functions will now report that they did not perform the
action requested because it was not possible.

iotests have been adjusted to address this new behavior.

(3)

block-job-complete doesn't worry about checking !block_job_started,
because the permission table guards against this.

(4)

test-bdrv-drain's job implementation needs to announce that it is
'ready' now, in order to be completed.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-03-19 12:01:24 +01:00
John Snow
58b295ba52 blockjobs: add status enum
We're about to add several new states, and booleans are becoming
unwieldly and difficult to reason about. It would help to have a
more explicit bookkeeping of the state of blockjobs. To this end,
add a new "status" field and add our existing states in a redundant
manner alongside the bools they are replacing:

UNDEFINED: Placeholder, default state. Not currently visible to QMP
           unless changes occur in the future to allow creating jobs
           without starting them via QMP.
CREATED:   replaces !!job->co && paused && !busy
RUNNING:   replaces effectively (!paused && busy)
PAUSED:    Nearly redundant with info->paused, which shows pause_count.
           This reports the actual status of the job, which almost always
           matches the paused request status. It differs in that it is
           strictly only true when the job has actually gone dormant.
READY:     replaces job->ready.
STANDBY:   Paused, but job->ready is true.

New state additions in coming commits will not be quite so redundant:

WAITING:   Waiting on transaction. This job has finished all the work
           it can until the transaction converges, fails, or is canceled.
PENDING:   Pending authorization from user. This job has finished all the
           work it can until the job or transaction is finalized via
           block_job_finalize. This implies the transaction has converged
           and left the WAITING phase.
ABORTING:  Job has encountered an error condition and is in the process
           of aborting.
CONCLUDED: Job has ceased all operations and has a return code available
           for query and may be dismissed via block_job_dismiss.
NULL:      Job has been dismissed and (should) be destroyed. Should never
           be visible to QMP.

Some of these states appear somewhat superfluous, but it helps define the
expected flow of a job; so some of the states wind up being synchronous
empty transitions. Importantly, jobs can be in only one of these states
at any given time, which helps code and external users alike reason about
the current condition of a job unambiguously.

Signed-off-by: John Snow <jsnow@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-03-19 12:01:24 +01:00
John Snow
62bfdf0ca1 Blockjobs: documentation touchup
Trivial; Document what the job creation flags do,
and some general tidying.

Signed-off-by: John Snow <jsnow@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-03-19 12:01:24 +01:00
John Snow
75859b9420 blockjobs: model single jobs as transactions
model all independent jobs as single job transactions.

It's one less case we have to worry about when we add more states to the
transition machine. This way, we can just treat all job lifetimes exactly
the same. This helps tighten assertions of the STM graph and removes some
conditionals that would have been needed in the coming commits adding a
more explicit job lifetime management API.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-03-19 12:01:24 +01:00
Peter Maydell
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Merge remote-tracking branch 'remotes/jnsnow/tags/bitmaps-pull-request' into staging

# gpg: Signature made Tue 13 Mar 2018 21:11:43 GMT
# gpg:                using RSA key 7DEF8106AAFC390E
# gpg: Good signature from "John Snow (John Huston) <jsnow@redhat.com>"
# Primary key fingerprint: FAEB 9711 A12C F475 812F  18F2 88A9 064D 1835 61EB
#      Subkey fingerprint: F9B7 ABDB BCAC DF95 BE76  CBD0 7DEF 8106 AAFC 390E

* remotes/jnsnow/tags/bitmaps-pull-request:
  iotests: add dirty bitmap postcopy test
  iotests: add dirty bitmap migration test
  migration: add postcopy migration of dirty bitmaps
  migration: allow qmp command migrate-start-postcopy for any postcopy
  migration: add is_active_iterate handler
  migration/qemu-file: add qemu_put_counted_string()
  migration: include migrate_dirty_bitmaps in migrate_postcopy
  qapi: add dirty-bitmaps migration capability
  migration: introduce postcopy-only pending
  dirty-bitmap: add locked state
  block/dirty-bitmap: add _locked version of bdrv_reclaim_dirty_bitmap
  block/dirty-bitmap: fix locking in bdrv_reclaim_dirty_bitmap
  block/dirty-bitmap: add bdrv_dirty_bitmap_enable_successor()

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2018-03-16 14:15:18 +00:00
Vladimir Sementsov-Ogievskiy
4f43e9535b dirty-bitmap: add locked state
Add special state, when qmp operations on the bitmap are disabled.
It is needed during bitmap migration. "Frozen" state is not
appropriate here, because it looks like bitmap is unchanged.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 20180207155837.92351-5-vsementsov@virtuozzo.com
Signed-off-by: John Snow <jsnow@redhat.com>
2018-03-13 17:05:00 -04:00
Vladimir Sementsov-Ogievskiy
044ee8e143 block/dirty-bitmap: add _locked version of bdrv_reclaim_dirty_bitmap
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 20180207155837.92351-4-vsementsov@virtuozzo.com
Signed-off-by: John Snow <jsnow@redhat.com>
2018-03-13 17:04:54 -04:00
Vladimir Sementsov-Ogievskiy
78a33ab587 nbd: BLOCK_STATUS for standard get_block_status function: client part
Minimal realization: only one extent in server answer is supported.
Flag NBD_CMD_FLAG_REQ_ONE is used to force this behavior.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20180312152126.286890-6-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[eblake: grammar tweaks, fix min_block check and 32-bit cap, use -1
instead of errno on failure in nbd_negotiate_simple_meta_context,
ensure that block status makes progress on success]
Signed-off-by: Eric Blake <eblake@redhat.com>
2018-03-13 15:43:48 -05:00
Vladimir Sementsov-Ogievskiy
e73a265e9f block/dirty-bitmap: add bdrv_dirty_bitmap_enable_successor()
Enabling bitmap successor is necessary to enable successors of bitmaps
being migrated before target vm start.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Message-id: 20180207155837.92351-2-vsementsov@virtuozzo.com
Signed-off-by: John Snow <jsnow@redhat.com>
2018-03-13 15:33:59 -04:00
Peter Maydell
834eddf22e -----BEGIN PGP SIGNATURE-----
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Merge remote-tracking branch 'remotes/stefanha/tags/block-pull-request' into staging

# gpg: Signature made Mon 12 Mar 2018 16:01:16 GMT
# gpg:                using RSA key 9CA4ABB381AB73C8
# gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>"
# gpg:                 aka "Stefan Hajnoczi <stefanha@gmail.com>"
# Primary key fingerprint: 8695 A8BF D3F9 7CDA AC35  775A 9CA4 ABB3 81AB 73C8

* remotes/stefanha/tags/block-pull-request:
  block: make BDRV_POLL_WHILE() re-entrancy safe

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2018-03-13 10:49:02 +00:00
Stefan Hajnoczi
7376eda7c2 block: make BDRV_POLL_WHILE() re-entrancy safe
Nested BDRV_POLL_WHILE() calls can occur.  Currently
assert(!wait_->wakeup) fails in AIO_WAIT_WHILE() when this happens.

This patch converts the bool wait_->need_kick flag to an unsigned
wait_->num_waiters counter.

Nesting works correctly because outer AIO_WAIT_WHILE() callers evaluate
the condition again after the inner caller completes (invoking the inner
caller counts as aio_poll() progress).

Reported-by: "fuweiwei (C)" <fuweiwei2@huawei.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20180307124619.6218-1-stefanha@redhat.com
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2018-03-12 11:07:37 +00:00
Peter Maydell
12c06d6f96 Block layer patches
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Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into staging

Block layer patches

# gpg: Signature made Fri 09 Mar 2018 15:09:20 GMT
# gpg:                using RSA key 7F09B272C88F2FD6
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>"
# Primary key fingerprint: DC3D EB15 9A9A F95D 3D74  56FE 7F09 B272 C88F 2FD6

* remotes/kevin/tags/for-upstream: (56 commits)
  qemu-iotests: fix 203 migration completion race
  iotests: Tweak 030 in order to trigger a race condition with parallel jobs
  iotests: Skip test for ENOMEM error
  iotests: Mark all tests executable
  iotests: Test creating overlay when guest running
  qemu-iotests: Test ssh image creation over QMP
  qemu-iotests: Test qcow2 over file image creation with QMP
  block: Fail bdrv_truncate() with negative size
  file-posix: Fix no-op bdrv_truncate() with falloc preallocation
  ssh: Support .bdrv_co_create
  ssh: Pass BlockdevOptionsSsh to connect_to_ssh()
  ssh: QAPIfy host-key-check option
  ssh: Use QAPI BlockdevOptionsSsh object
  sheepdog: Support .bdrv_co_create
  sheepdog: QAPIfy "redundancy" create option
  nfs: Support .bdrv_co_create
  nfs: Use QAPI options in nfs_client_open()
  rbd: Use qemu_rbd_connect() in qemu_rbd_do_create()
  rbd: Assign s->snap/image_name in qemu_rbd_open()
  rbd: Support .bdrv_co_create
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2018-03-12 10:08:09 +00:00
Kevin Wolf
b0292b851b block: x-blockdev-create QMP command
This adds a synchronous x-blockdev-create QMP command that can create
qcow2 images on a given node name.

We don't want to block while creating an image, so this is not the final
interface in all aspects, but BlockdevCreateOptionsQcow2 and
.bdrv_co_create() are what they actually might look like in the end. In
any case, this should be good enough to test whether we interpret
BlockdevCreateOptions as we should.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2018-03-09 15:17:47 +01:00
Kevin Wolf
e8eb863778 block: Make bdrv_is_whitelisted() public
We'll use a separate source file for image creation, and we need to
check there whether the requested driver is whitelisted.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2018-03-09 15:17:47 +01:00
Kevin Wolf
e1d74bc6c6 qcow2: Use BlockdevRef in qcow2_co_create()
Instead of passing a separate BlockDriverState* into qcow2_co_create(),
make use of the BlockdevRef that is included in BlockdevCreateOptions.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2018-03-09 15:17:47 +01:00
Paolo Bonzini
2fd6163884 block: convert bdrv_check callback to coroutine_fn
Suggested-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1516279431-30424-8-git-send-email-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-03-09 15:17:47 +01:00
Paolo Bonzini
2b148f392b block: convert bdrv_invalidate_cache callback to coroutine_fn
QED's bdrv_invalidate_cache implementation would like to reuse functions
that acquire/release the metadata locks.  Call it from coroutine context
to simplify the logic.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1516279431-30424-6-git-send-email-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-03-09 15:17:47 +01:00
Stefan Hajnoczi
b89d92f3cf block: add aio_wait_bh_oneshot()
Sometimes it's necessary for the main loop thread to run a BH in an
IOThread and wait for its completion.  This primitive is useful during
startup/shutdown to synchronize and avoid race conditions.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 20180307144205.20619-2-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2018-03-08 17:38:51 +00:00
Peter Maydell
58e2e17dba Block layer patches
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Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into staging

Block layer patches

# gpg: Signature made Mon 05 Mar 2018 17:45:51 GMT
# gpg:                using RSA key 7F09B272C88F2FD6
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>"
# Primary key fingerprint: DC3D EB15 9A9A F95D 3D74  56FE 7F09 B272 C88F 2FD6

* remotes/kevin/tags/for-upstream: (38 commits)
  block: Fix NULL dereference on empty drive error
  qcow2: Replace align_offset() with ROUND_UP()
  block/ssh: Add basic .bdrv_truncate()
  block/ssh: Make ssh_grow_file() blocking
  block/ssh: Pull ssh_grow_file() from ssh_create()
  qemu-img: Make resize error message more general
  qcow2: make qcow2_co_create2() a coroutine_fn
  block: rename .bdrv_create() to .bdrv_co_create_opts()
  Revert "IDE: Do not flush empty CDROM drives"
  block: test blk_aio_flush() with blk->root == NULL
  block: add BlockBackend->in_flight counter
  block: extract AIO_WAIT_WHILE() from BlockDriverState
  aio: rename aio_context_in_iothread() to in_aio_context_home_thread()
  docs: document how to use the l2-cache-entry-size parameter
  specs/qcow2: Fix documentation of the compressed cluster descriptor
  iotest 033: add misaligned write-zeroes test via truncate
  block: fix write with zero flag set and iovector provided
  block: Drop unused .bdrv_co_get_block_status()
  vvfat: Switch to .bdrv_co_block_status()
  vpc: Switch to .bdrv_co_block_status()
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

# Conflicts:
#	include/block/block.h
2018-03-06 11:20:44 +00:00
Markus Armbruster
9af2398977 Include less of the generated modular QAPI headers
In my "build everything" tree, a change to the types in
qapi-schema.json triggers a recompile of about 4800 out of 5100
objects.

The previous commit split up qmp-commands.h, qmp-event.h, qmp-visit.h,
qapi-types.h.  Each of these headers still includes all its shards.
Reduce compile time by including just the shards we actually need.

To illustrate the benefits: adding a type to qapi/migration.json now
recompiles some 2300 instead of 4800 objects.  The next commit will
improve it further.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20180211093607.27351-24-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
[eblake: rebase to master]
Signed-off-by: Eric Blake <eblake@redhat.com>
2018-03-02 13:45:50 -06:00
Stefan Hajnoczi
efc75e2a4c block: rename .bdrv_create() to .bdrv_co_create_opts()
BlockDriver->bdrv_create() has been called from coroutine context since
commit 5b7e1542cf ("block: make
bdrv_create adopt coroutine").

Make this explicit by renaming to .bdrv_co_create_opts() and add the
coroutine_fn annotation.  This makes it obvious to block driver authors
that they may yield, use CoMutex, or other coroutine_fn APIs.
bdrv_co_create is reserved for the QAPI-based version that Kevin is
working on.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20170705102231.20711-2-stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-03-02 18:39:07 +01:00
Stefan Hajnoczi
7719f3c968 block: extract AIO_WAIT_WHILE() from BlockDriverState
BlockDriverState has the BDRV_POLL_WHILE() macro to wait on event loop
activity while a condition evaluates to true.  This is used to implement
synchronous operations where it acts as a condvar between the IOThread
running the operation and the main loop waiting for the operation.  It
can also be called from the thread that owns the AioContext and in that
case it's just a nested event loop.

BlockBackend needs this behavior but doesn't always have a
BlockDriverState it can use.  This patch extracts BDRV_POLL_WHILE() into
the AioWait abstraction, which can be used with AioContext and isn't
tied to BlockDriverState anymore.

This feature could be built directly into AioContext but then all users
would kick the event loop even if they signal different conditions.
Imagine an AioContext with many BlockDriverStates, each time a request
completes any waiter would wake up and re-check their condition.  It's
nicer to keep a separate AioWait object for each condition instead.

Please see "block/aio-wait.h" for details on the API.

The name AIO_WAIT_WHILE() avoids the confusion between AIO_POLL_WHILE()
and AioContext polling.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-03-02 18:39:07 +01:00
Stefan Hajnoczi
d2b63ba8dd aio: rename aio_context_in_iothread() to in_aio_context_home_thread()
The name aio_context_in_iothread() is misleading because it also returns
true when called on the main AioContext from the main loop thread, which
is not an IOThread.

This patch renames it to in_aio_context_home_thread() and expands the
doc comment to make the semantics clearer.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-03-02 18:39:07 +01:00
Eric Blake
636cb51258 block: Drop unused .bdrv_co_get_block_status()
We are gradually moving away from sector-based interfaces, towards
byte-based.  Now that all drivers have been updated to provide the
byte-based .bdrv_co_block_status(), we can delete the sector-based
interface.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-03-02 18:39:07 +01:00
Eric Blake
3e4d0e72b7 block: Switch passthrough drivers to .bdrv_co_block_status()
We are gradually moving away from sector-based interfaces, towards
byte-based.  Update the generic helpers, and all passthrough clients
(blkdebug, commit, mirror, throttle) accordingly.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-03-02 18:39:07 +01:00
Eric Blake
86a3d5c688 block: Add .bdrv_co_block_status() callback
We are gradually moving away from sector-based interfaces, towards
byte-based. Now that the block layer exposes byte-based allocation,
it's time to tackle the drivers.  Add a new callback that operates
on as small as byte boundaries. Subsequent patches will then update
individual drivers, then finally remove .bdrv_co_get_block_status().

The new code also passes through the 'want_zero' hint, which will
allow subsequent patches to further optimize callers that only care
about how much of the image is allocated (want_zero is false),
rather than full details about runs of zeroes and which offsets the
allocation actually maps to (want_zero is true).  As part of this
effort, fix another part of the documentation: the claim in commit
4c41cb4 that BDRV_BLOCK_ALLOCATED is short for 'DATA || ZERO' is a
lie at the block layer (see commit e88ae2264), even though it is
how the bit is computed from the driver layer.  After all, there
are intentionally cases where we return ZERO but not ALLOCATED at
the block layer, when we know that a read sees zero because the
backing file is too short.  Note that the driver interface is thus
slightly different than the public interface with regards to which
bits will be set, and what guarantees are provided on input.

We also add an assertion that any driver using the new callback will
make progress (the only time pnum will be 0 is if the block layer
already handled an out-of-bounds request, or if there is an error);
the old driver interface did not provide this guarantee, which
could lead to some inf-loops in drastic corner-case failures.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-03-02 18:39:07 +01:00
Vladimir Sementsov-Ogievskiy
25c146789f nbd: BLOCK_STATUS constants
Expose the new constants and structs that will be used by both
server and client implementations of NBD_CMD_BLOCK_STATUS (the
command is currently experimental at
https://github.com/NetworkBlockDevice/nbd/blob/extension-blockstatus/doc/proto.md
but will hopefully be stabilized soon).

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <1518702707-7077-4-git-send-email-vsementsov@virtuozzo.com>
[eblake: split from larger patch on server implementation]
Signed-off-by: Eric Blake <eblake@redhat.com>
2018-03-01 14:05:24 -06:00
Vladimir Sementsov-Ogievskiy
6bc8695725 nbd: change indenting in nbd.h
Prepared indenting for the following patch.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <1518702707-7077-3-git-send-email-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2018-03-01 14:04:45 -06:00
Vladimir Sementsov-Ogievskiy
3e99da5e76 block: maintain persistent disabled bitmaps
To maintain load/store disabled bitmap there is new approach:

 - deprecate @autoload flag of block-dirty-bitmap-add, make it ignored
 - store enabled bitmaps as "auto" to qcow2
 - store disabled bitmaps without "auto" flag to qcow2
 - on qcow2 open load "auto" bitmaps as enabled and others
   as disabled (except in_use bitmaps)

Also, adjust iotests 165 and 176 appropriately.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20180202160752.143796-1-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-02-13 16:59:58 +01:00
Eric Blake
e24d813b29 block: Simplify bdrv_can_write_zeroes_with_unmap()
We don't need the can_write_zeroes_with_unmap field in
BlockDriverInfo, because it is redundant information with
supported_zero_flags & BDRV_REQ_MAY_UNMAP.  Note that
BlockDriverInfo and supported_zero_flags are both per-device
settings, rather than global state about the driver as a
whole, which means one or both of these bits of information
can already be conditional.  Let's audit how they were set:

crypto: always setting can_write_ to false is pointless (the
struct starts life zero-initialized), no use of supported_

nbd: just recently fixed to set can_write_ if supported_
includes MAY_UNMAP (thus this commit effectively reverts
bca80059e and solves the problem mentioned there in a more
global way)

file-posix, iscsi, qcow2: can_write_ is conditional, while
supported_ was unconditional; but passing MAY_UNMAP would
fail with ENOTSUP if the condition wasn't met

qed: can_write_ is unconditional, but pwrite_zeroes lacks
support for MAY_UNMAP and supported_ is not set. Perhaps
support can be added later (since it would be similar to
qcow2), but for now claiming false is no real loss

all other drivers: can_write_ is not set, and supported_ is
either unset or a passthrough

Simplify the code by moving the conditional into
supported_zero_flags for all drivers, then dropping the
now-unused BDI field.  For callers that relied on
bdrv_can_write_zeroes_with_unmap(), we return the same
per-device settings for drivers that had conditions (no
observable change in behavior there); and can now return
true (instead of false) for drivers that support passthrough
(for example, the commit driver) which gives those drivers
the same fix as nbd just got in bca80059e.  For callers that
relied on supported_zero_flags, we now have a few more places
that can avoid a wasted call to pwrite_zeroes() that will
just fail with ENOTSUP.

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180126193439.20219-1-eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2018-02-09 12:32:44 -06:00
Markus Armbruster
922a01a013 Move include qemu/option.h from qemu-common.h to actual users
qemu-common.h includes qemu/option.h, but most places that include the
former don't actually need the latter.  Drop the include, and add it
to the places that actually need it.

While there, drop superfluous includes of both headers, and
separate #include from file comment with a blank line.

This cleanup makes the number of objects depending on qemu/option.h
drop from 4545 (out of 4743) to 284 in my "build everything" tree.

Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20180201111846.21846-20-armbru@redhat.com>
[Semantic conflict with commit bdd6a90a9e in block/nvme.c resolved]
2018-02-09 13:52:16 +01:00
Markus Armbruster
452fcdbc49 Include qapi/qmp/qdict.h exactly where needed
This cleanup makes the number of objects depending on qapi/qmp/qdict.h
drop from 4550 (out of 4743) to 368 in my "build everything" tree.
For qapi/qmp/qobject.h, the number drops from 4552 to 390.

While there, separate #include from file comment with a blank line.

Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20180201111846.21846-13-armbru@redhat.com>
2018-02-09 13:52:15 +01:00
Markus Armbruster
5ee9d2fe9e Include qapi/qmp/qobject.h exactly where needed
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20180201111846.21846-11-armbru@redhat.com>
2018-02-09 13:52:15 +01:00
Markus Armbruster
522ece32d2 Drop superfluous includes of qapi-types.h and test-qapi-types.h
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20180201111846.21846-4-armbru@redhat.com>
2018-02-09 05:05:11 +01:00
Fam Zheng
a3d9a352d4 block: Move NVMe constants to a separate header
Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20180116060901.17413-8-famz@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
2018-02-08 09:22:03 +08:00
Fam Zheng
23d0ba9319 block: Introduce buf register API
Allow block driver to map and unmap a buffer for later I/O, as a performance
hint.

Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20180116060901.17413-5-famz@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
2018-02-08 09:22:03 +08:00
Vladimir Sementsov-Ogievskiy
a3b0dc7582 qapi: add nbd-server-remove
Add command for removing an export. It is needed for cases when we
don't want to keep the export after the operation on it was completed.
The other example is a temporary node, created with blockdev-add.
If we want to delete it we should firstly remove any corresponding
NBD export.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20180119135719.24745-3-vsementsov@virtuozzo.com>
[eblake: drop dead nb_clients code]
Signed-off-by: Eric Blake <eblake@redhat.com>
2018-01-26 09:37:20 -06:00
Vladimir Sementsov-Ogievskiy
420a4e9559 nbd: rename nbd_option and nbd_opt_reply
Rename nbd_option and nbd_opt_reply to NBDOption and NBDOptionReply
to correspond to Qemu coding style and other structures here.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20171122101958.17065-5-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2018-01-10 12:11:23 -06:00
Kevin Wolf
d736f119da block: Allow graph changes in subtree drained section
We need to remember how many of the drain sections in which a node is
were recursive (i.e. subtree drain rather than node drain), so that they
can be correctly applied when children are added or removed during the
drained section.

With this change, it is safe to modify the graph even inside a
bdrv_subtree_drained_begin/end() section.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-12-22 15:05:32 +01:00
Kevin Wolf
b016558590 block: Add bdrv_subtree_drained_begin/end()
bdrv_drained_begin() waits for the completion of requests in the whole
subtree, but it only actually keeps its immediate bs parameter quiesced
until bdrv_drained_end().

Add a version that keeps the whole subtree drained. As of this commit,
graph changes cannot be allowed during a subtree drained section, but
this will be fixed soon.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-12-22 15:05:32 +01:00
Kevin Wolf
0152bf400f block: Don't notify parents in drain call chain
This is in preparation for subtree drains, i.e. drained sections that
affect not only a single node, but recursively all child nodes, too.

Calling the parent callbacks for drain is pointless when we just came
from that parent node recursively and leads to multiple increases of
bs->quiesce_counter in a single drain call. Don't do it.

In order for this to work correctly, the parent callback must be called
for every bdrv_drain_begin/end() call, not only for the outermost one:

If we have a node N with two parents A and B, recursive draining of A
should cause the quiesce_counter of B to increase because its child N is
drained independently of B. If now B is recursively drained, too, A must
increase its quiesce_counter because N is drained independently of A
only now, even if N is going from quiesce_counter 1 to 2.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-12-22 15:05:32 +01:00
Fam Zheng
8e77e0bceb block: Remove unused bdrv_requests_pending
Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-12-22 15:05:31 +01:00
Vladimir Sementsov-Ogievskiy
56207df55e hbitmap: add next_zero function
The function searches for next zero bit.
Also add interface for BdrvDirtyBitmap and unit test.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 20171012135313.227864-2-vsementsov@virtuozzo.com
Signed-off-by: Jeff Cody <jcody@redhat.com>
2017-12-18 10:54:13 -05:00
Paolo Bonzini
fc24908e7d blockjob: reimplement block_job_sleep_ns to allow cancellation
This reverts the effects of commit 4afeffc857 ("blockjob: do not allow
coroutine double entry or entry-after-completion", 2017-11-21)

This fixed the symptom of a bug rather than the root cause. Canceling the
wait on a sleeping blockjob coroutine is generally fine, we just need to
make it work correctly across AioContexts.  To do so, use a QEMUTimer
that calls block_job_enter.  Use a mutex to ensure that block_job_enter
synchronizes correctly with block_job_sleep_ns.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Tested-By: Jeff Cody <jcody@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-11-29 15:26:21 +01:00
Paolo Bonzini
5bf1d5a73a blockjob: remove clock argument from block_job_sleep_ns
All callers are using QEMU_CLOCK_REALTIME, and it will not be possible to
support more than one clock when block_job_sleep_ns switches to a single
timer stored in the BlockJob struct.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Tested-By: Jeff Cody <jcody@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-11-29 15:11:02 +01:00
Peter Maydell
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Merge remote-tracking branch 'remotes/cody/tags/block-pull-request' into staging

# gpg: Signature made Tue 21 Nov 2017 17:01:33 GMT
# gpg:                using RSA key 0xBDBE7B27C0DE3057
# gpg: Good signature from "Jeffrey Cody <jcody@redhat.com>"
# gpg:                 aka "Jeffrey Cody <jeff@codyprime.org>"
# gpg:                 aka "Jeffrey Cody <codyprime@gmail.com>"
# Primary key fingerprint: 9957 4B4D 3474 90E7 9D98  D624 BDBE 7B27 C0DE 3057

* remotes/cody/tags/block-pull-request:
  qemu-iotest: add test for blockjob coroutine race condition
  qemu-iotests: add option in common.qemu for mismatch only
  coroutine: abort if we try to schedule or enter a pending coroutine
  blockjob: do not allow coroutine double entry or entry-after-completion

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2017-11-21 17:05:49 +00:00
Jeff Cody
4afeffc857 blockjob: do not allow coroutine double entry or entry-after-completion
When block_job_sleep_ns() is called, the co-routine is scheduled for
future execution.  If we allow the job to be re-entered prior to the
scheduled time, we present a race condition in which a coroutine can be
entered recursively, or even entered after the coroutine is deleted.

The job->busy flag is used by blockjobs when a coroutine is busy
executing. The function 'block_job_enter()' obeys the busy flag,
and will not enter a coroutine if set.  If we sleep a job, we need to
leave the busy flag set, so that subsequent calls to block_job_enter()
are prevented.

This changes the prior behavior of block_job_cancel() being able to
immediately wake up and cancel a job; in practice, this should not be an
issue, as the coroutine sleep times are generally very small, and the
cancel will occur the next time the coroutine wakes up.

This fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1508708

Signed-off-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-11-21 11:51:18 -05:00
Kevin Wolf
2b624fe079 block: Add errp to bdrv_all_goto_snapshot()
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
2017-11-21 14:48:22 +01:00
Kevin Wolf
0b62bcbc61 block: Add errp to bdrv_snapshot_goto()
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
2017-11-21 14:48:22 +01:00
Max Reitz
5e003f17ec block: Make bdrv_next() keep strong references
On one hand, it is a good idea for bdrv_next() to return a strong
reference because ideally nearly every pointer should be refcounted.
This fixes intermittent failure of iotest 194.

On the other, it is absolutely necessary for bdrv_next() itself to keep
a strong reference to both the BB (in its first phase) and the BDS (at
least in the second phase) because when called the next time, it will
dereference those objects to get a link to the next one.  Therefore, it
needs these objects to stay around until then.  Just storing the pointer
to the next in the iterator is not really viable because that pointer
might become invalid as well.

Both arguments taken together means we should probably just invoke
bdrv_ref() and blk_ref() in bdrv_next().  This means we have to assert
that bdrv_next() is always called from the main loop, but that was
probably necessary already before this patch and judging from the
callers, it also looks to actually be the case.

Keeping these strong references means however that callers need to give
them up if they decide to abort the iteration early.  They can do so
through the new bdrv_next_cleanup() function.

Suggested-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20171110172545.32609-1-mreitz@redhat.com
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-11-17 18:21:31 +01:00
Eric Blake
efdc0c103d nbd: Fix struct name for structured reads
A closer read of the NBD spec shows that a structured reply chunk
for a hole is not quite identical to the prefix of a data chunk,
because the hole has to also send a 32-bit size field.  Although
we do not yet send holes, we should fix the misleading information
in our header and make it easier for a future patch to support
sparse reads.  Messed up in commit bae245d1.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20171108215703.9295-5-eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2017-11-09 10:17:12 -06:00
Vladimir Sementsov-Ogievskiy
f140e30003 nbd: Minimal structured read for client
Minimal implementation: for structured error only error_report error
message.

Note that test 83 is now more verbose, because the implementation
prints more warnings about unexpected communication errors; perhaps
future patches should tone things down by using trace messages
instead of traces, but the common case of successful communication
is no noisier than before.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20171027104037.8319-13-eblake@redhat.com>
2017-10-30 21:48:41 +01:00
Eric Blake
56dc682bf5 nbd: Move nbd_read() to common header
An upcoming change to block/nbd-client.c will want to read the
tail of a structured reply chunk directly from the wire.  Move
this function to make it easier.

Based on a patch from Vladimir Sementsov-Ogievskiy.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20171027104037.8319-12-eblake@redhat.com>
2017-10-30 21:48:36 +01:00
Vladimir Sementsov-Ogievskiy
d2febedb45 nbd/client: prepare nbd_receive_reply for structured reply
In following patch nbd_receive_reply will be used both for simple
and structured reply header receiving.
NBDReply is altered into union of simple reply header and structured
reply chunk header, simple error translation moved to block/nbd-client
to be consistent with further structured reply error translation.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20171027104037.8319-11-eblake@redhat.com>
2017-10-30 21:48:32 +01:00
Eric Blake
bae245d19a nbd: Expose constants and structs for structured read
Upcoming patches will implement the NBD structured reply
extension [1] for both client and server roles.  Declare the
constants, structs, and lookup routines that will be valuable
whether the server or client code is backported in isolation.

This includes moving one constant from an internal header to
the public header, as part of the structured read processing
will be done in block/nbd-client.c rather than nbd/client.c.

[1]https://github.com/NetworkBlockDevice/nbd/blob/extension-structured-reply/doc/proto.md

Based on patches from Vladimir Sementsov-Ogievskiy.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20171027104037.8319-4-eblake@redhat.com>
2017-10-30 21:07:21 +01:00
Eric Blake
dd68944049 nbd: Move nbd_errno_to_system_errno() to public header
This is needed in preparation for structured reply handling,
as we will be performing the translation from NBD error to
system errno value higher in the stack at block/nbd-client.c.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20171027104037.8319-3-eblake@redhat.com>
2017-10-30 21:07:21 +01:00
Eric Blake
efa6e2ed64 block: Align block status requests
Any device that has request_alignment greater than 512 should be
unable to report status at a finer granularity; it may also be
simpler for such devices to be guaranteed that the block layer
has rounded things out to the granularity boundary (the way the
block layer already rounds all other I/O out).  Besides, getting
the code correct for super-sector alignment also benefits us
for the fact that our public interface now has byte granularity,
even though none of our drivers have byte-level callbacks.

Add an assertion in blkdebug that proves that the block layer
never requests status of unaligned sections, similar to what it
does on other requests (while still keeping the generic helper
in place for when future patches add a throttle driver).  Note
that iotest 177 already covers this (it would fail if you use
just the blkdebug.c hunk without the io.c changes).  Meanwhile,
we can drop assertions in callers that no longer have to pass
in sector-aligned addresses.

There is a mid-function scope added for 'count' and 'longret',
for a couple of reasons: first, an upcoming patch will add an
'if' statement that checks whether a driver has an old- or
new-style callback, and can conveniently use the same scope for
less indentation churn at that time.  Second, since we are
trying to get rid of sector-based computations, wrapping things
in a scope makes it easier to group and see what will be
deleted in a final cleanup patch once all drivers have been
converted to the new-style callback.

Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-10-26 14:45:57 +02:00
Eric Blake
3182664220 block: Convert bdrv_get_block_status_above() to bytes
We are gradually moving away from sector-based interfaces, towards
byte-based.  In the common case, allocation is unlikely to ever use
values that are not naturally sector-aligned, but it is possible
that byte-based values will let us be more precise about allocation
at the end of an unaligned file that can do byte-based access.

Changing the name of the function from bdrv_get_block_status_above()
to bdrv_block_status_above() ensures that the compiler enforces that
all callers are updated.  Likewise, since it a byte interface allows
an offset mapping that might not be sector aligned, split the mapping
out of the return value and into a pass-by-reference parameter.  For
now, the io.c layer still assert()s that all uses are sector-aligned,
but that can be relaxed when a later patch implements byte-based
block status in the drivers.

For the most part this patch is just the addition of scaling at the
callers followed by inverse scaling at bdrv_block_status(), plus
updates for the new split return interface.  But some code,
particularly bdrv_block_status(), gets a lot simpler because it no
longer has to mess with sectors.  Likewise, mirror code no longer
computes s->granularity >> BDRV_SECTOR_BITS, and can therefore drop
an assertion about alignment because the loop no longer depends on
alignment (never mind that we don't really have a driver that
reports sub-sector alignments, so it's not really possible to test
the effect of sub-sector mirroring).  Fix a neighboring assertion to
use is_power_of_2 while there.

For ease of review, bdrv_get_block_status() was tackled separately.

Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-10-26 14:45:57 +02:00
Eric Blake
237d78f8fc block: Convert bdrv_get_block_status() to bytes
We are gradually moving away from sector-based interfaces, towards
byte-based.  In the common case, allocation is unlikely to ever use
values that are not naturally sector-aligned, but it is possible
that byte-based values will let us be more precise about allocation
at the end of an unaligned file that can do byte-based access.

Changing the name of the function from bdrv_get_block_status() to
bdrv_block_status() ensures that the compiler enforces that all
callers are updated.  For now, the io.c layer still assert()s that
all callers are sector-aligned, but that can be relaxed when a later
patch implements byte-based block status in the drivers.

There was an inherent limitation in returning the offset via the
return value: we only have room for BDRV_BLOCK_OFFSET_MASK bits, which
means an offset can only be mapped for sector-aligned queries (or,
if we declare that non-aligned input is at the same relative position
modulo 512 of the answer), so the new interface also changes things to
return the offset via output through a parameter by reference rather
than mashed into the return value.  We'll have some glue code that
munges between the two styles until we finish converting all uses.

For the most part this patch is just the addition of scaling at the
callers followed by inverse scaling at bdrv_block_status(), coupled
with the tweak in calling convention.  But some code, particularly
bdrv_is_allocated(), gets a lot simpler because it no longer has to
mess with sectors.

For ease of review, bdrv_get_block_status_above() will be tackled
separately.

Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-10-26 14:45:57 +02:00
Eric Blake
7cfd527525 block: Make bdrv_round_to_clusters() signature more useful
In the process of converting sector-based interfaces to bytes,
I'm finding it easier to represent a byte count as a 64-bit
integer at the block layer (even if we are internally capped
by SIZE_MAX or even INT_MAX for individual transactions, it's
still nicer to not have to worry about truncation/overflow
issues on as many variables).  Update the signature of
bdrv_round_to_clusters() to uniformly use int64_t, matching
the signature already chosen for bdrv_is_allocated and the
fact that off_t is also a signed type, then adjust clients
according to the required fallout (even where the result could
now exceed 32 bits, no client is directly assigning the result
into a 32-bit value without breaking things into a loop first).

Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-10-26 14:45:57 +02:00
Eric Blake
298a1665a2 block: Allow NULL file for bdrv_get_block_status()
Not all callers care about which BDS owns the mapping for a given
range of the file.  This patch merely simplifies the callers by
consolidating the logic in the common call point, while guaranteeing
a non-NULL file to all the driver callbacks, for no semantic change.
The only caller that does not care about pnum is bdrv_is_allocated,
as invoked by vvfat; we can likewise add assertions that the rest
of the stack does not have to worry about a NULL pnum.

Furthermore, this will also set the stage for a future cleanup: when
a caller does not care about which BDS owns an offset, it would be
nice to allow the driver to optimize things to not have to return
BDRV_BLOCK_OFFSET_VALID in the first place.  In the case of fragmented
allocation (for example, it's fairly easy to create a qcow2 image
where consecutive guest addresses are not at consecutive host
addresses), the current contract requires bdrv_get_block_status()
to clamp *pnum to the limit where host addresses are no longer
consecutive, but allowing a NULL file means that *pnum could be
set to the full length of known-allocated data.

Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-10-26 14:45:57 +02:00
Peter Maydell
79b2a13aa8 nbd patches for 2017-10-14
- Marc-André Lureau - NBD: use g_new() family of functions
 - Vladimir Sementsov-Ogievskiy - first half of 00/13 nbd minimal structured read
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 Comment: Public key at http://people.redhat.com/eblake/eblake.gpg
 
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Merge remote-tracking branch 'remotes/ericb/tags/pull-nbd-2017-10-14' into staging

nbd patches for 2017-10-14

- Marc-André Lureau - NBD: use g_new() family of functions
- Vladimir Sementsov-Ogievskiy - first half of 00/13 nbd minimal structured read

# gpg: Signature made Sun 15 Oct 2017 01:38:47 BST
# gpg:                using RSA key 0xA7A16B4A2527436A
# gpg: Good signature from "Eric Blake <eblake@redhat.com>"
# gpg:                 aka "Eric Blake (Free Software Programmer) <ebb9@byu.net>"
# gpg:                 aka "[jpeg image of size 6874]"
# Primary key fingerprint: 71C2 CC22 B1C4 6029 27D2  F3AA A7A1 6B4A 2527 436A

* remotes/ericb/tags/pull-nbd-2017-10-14:
  nbd: header constants indenting
  nbd/server: simplify reply transmission
  nbd/server: refactor nbd_co_send_simple_reply parameters
  nbd/server: do not use NBDReply structure
  nbd/server: structurize simple reply header sending
  nbd: rename some simple-request related objects to be _simple_
  block/nbd-client: refactor nbd_co_receive_reply
  block/nbd-client: assert qiov len once in nbd_co_request
  NBD: use g_new() family of functions

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2017-10-16 15:54:42 +01:00
Vladimir Sementsov-Ogievskiy
92652b1243 nbd: header constants indenting
Prepare indenting for the following commit.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20171012095319.136610-9-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2017-10-13 09:27:38 -05:00
Manos Pitsidianakis
f8ea8dacf0 block: rename bdrv_co_drain to bdrv_co_drain_begin
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Manos Pitsidianakis <el13635@mail.ntua.gr>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-10-13 12:38:41 +01:00
Manos Pitsidianakis
481cad48e5 block: add bdrv_co_drain_end callback
BlockDriverState has a bdrv_co_drain() callback but no equivalent for
the end of the drain. The throttle driver (block/throttle.c) needs a way
to mark the end of the drain in order to toggle io_limits_disabled
correctly, thus bdrv_co_drain_end is needed.

Signed-off-by: Manos Pitsidianakis <el13635@mail.ntua.gr>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-10-13 12:38:41 +01:00
Vladimir Sementsov-Ogievskiy
caad53845a nbd/server: structurize simple reply header sending
Use packed structure instead of pointer arithmetics.

Also, merge two redundant traces into one.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20171012095319.136610-5-vsementsov@virtuozzo.com>
[eblake: tweak and mention impact on traces, fix errp usage]
Signed-off-by: Eric Blake <eblake@redhat.com>
2017-10-12 16:53:15 -05:00
Kevin Wolf
bde70715b6 commit: Remove overlay_bs
We don't need to make any assumptions about the graph layout above the
top node of the commit operation any more. Remove the use of
bdrv_find_overlay() and related variables from the commit job code.

bdrv_drop_intermediate() doesn't use the 'active' parameter any more, so
we can just drop it.

The overlay node was previously added to the block job to get a
BLK_PERM_GRAPH_MOD. We really need to respect those permissions in
bdrv_drop_intermediate() now, but as long as we haven't figured out yet
how BLK_PERM_GRAPH_MOD is actually supposed to work, just leave a TODO
comment there.

With this change, it is now possible to perform another block job on an
overlay node without conflicts. qemu-iotests 030 is changed accordingly.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2017-10-06 16:28:58 +02:00
Kevin Wolf
6858eba09e block: Introduce BdrvChildRole.update_filename
There is no good reason for bdrv_drop_intermediate() to know the active
layer above the subchain it is operating on - even more so, because
the assumption that there is a single active layer above it is not
generally true.

In order to prepare removal of the active parameter, use a BdrvChildRole
callback to update the backing file string in the overlay image instead
of directly calling bdrv_change_backing_file().

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2017-10-06 16:28:58 +02:00
Eric Blake
0fdf1a4f68 dirty-bitmap: Switch bdrv_set_dirty() to bytes
Both callers already had bytes available, but were scaling to
sectors.  Move the scaling to internal code.  In the case of
bdrv_aligned_pwritev(), we are now passing the exact offset
rather than a rounded sector-aligned value, but that's okay
as long as dirty bitmap widens start/bytes to granularity
boundaries.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-10-06 16:28:58 +02:00
Eric Blake
e0d7f73e63 dirty-bitmap: Change bdrv_[re]set_dirty_bitmap() to use bytes
Some of the callers were already scaling bytes to sectors; others
can be easily converted to pass byte offsets, all in our shift
towards a consistent byte interface everywhere.  Making the change
will also make it easier to write the hold-out callers to use byte
rather than sectors for their iterations; it also makes it easier
for a future dirty-bitmap patch to offload scaling over to the
internal hbitmap.  Although all callers happen to pass
sector-aligned values, make the internal scaling robust to any
sub-sector requests.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-10-06 16:28:58 +02:00
Eric Blake
3b5d4df0c6 dirty-bitmap: Change bdrv_get_dirty_locked() to take bytes
Half the callers were already scaling bytes to sectors; the other
half can eventually be simplified to use byte iteration.  Both
callers were already using the result as a bool, so make that
explicit.  Making the change also makes it easier for a future
dirty-bitmap patch to offload scaling over to the internal hbitmap.

Remember, asking whether a byte is dirty is effectively asking
whether the entire granularity containing the byte is dirty, since
we only track dirtiness by granularity.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-10-06 16:28:58 +02:00
Eric Blake
715a74d819 dirty-bitmap: Set iterator start by offset, not sector
All callers to bdrv_dirty_iter_new() passed 0 for their initial
starting point, drop that parameter.

Most callers to bdrv_set_dirty_iter() were scaling a byte offset to
a sector number; the exception qcow2-bitmap will be converted later
to use byte rather than sector iteration.  Move the scaling to occur
internally to dirty bitmap code instead, so that callers now pass
in bytes.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-10-06 16:28:58 +02:00
Eric Blake
86f6ae67e1 dirty-bitmap: Change bdrv_dirty_bitmap_*serialize*() to take bytes
Right now, the dirty-bitmap code exposes the fact that we use
a scale of sector granularity in the underlying hbitmap to anything
that wants to serialize a dirty bitmap.  It's nicer to uniformly
expose bytes as our dirty-bitmap interface, matching the previous
change to bitmap size.  The only caller to serialization is currently
qcow2-cluster.c, which becomes a bit more verbose because it is still
tracking sectors for other reasons, but a later patch will fix that
to more uniformly use byte offsets everywhere.  Likewise, within
dirty-bitmap, we have to add more assertions that we are not
truncating incorrectly, which can go away once the internal hbitmap
is byte-based rather than sector-based.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-10-06 16:28:58 +02:00
Eric Blake
1b6cc579de dirty-bitmap: Avoid size query failure during truncate
We've previously fixed several places where we failed to account
for possible errors from bdrv_nb_sectors().  Fix another one by
making bdrv_dirty_bitmap_truncate() take the new size from the
caller instead of querying itself; then adjust the sole caller
bdrv_truncate() to pass the size just determined by a successful
resize, or to reuse the size given to the original truncate
operation when refresh_total_sectors() was not able to confirm the
actual size (the two sizes can potentially differ according to
rounding constraints), thus avoiding sizing the bitmaps to -1.
This also fixes a bug where not all failure paths in
bdrv_truncate() would set errp.

Note that bdrv_truncate() is still a bit awkward.  We may want
to revisit it later and clean up things to better guarantee that
a resize attempt either fails cleanly up front, or cannot fail
after guest-visible changes have been made (if temporary changes
are made, then they need to be cleanly rolled back).  But that
is a task for another day; for now, the goal is the bare minimum
fix to ensure that just bdrv_dirty_bitmap_truncate() cannot fail.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-10-06 16:28:58 +02:00
Eric Blake
dfe55c3577 dirty-bitmap: Drop unused functions
We had several functions that no one is currently using, and which
use sector-based interfaces.  I'm trying to convert towards byte-based
interfaces, so it's easier to just drop the unused functions:

bdrv_dirty_bitmap_get_meta
bdrv_dirty_bitmap_get_meta_locked
bdrv_dirty_bitmap_reset_meta
bdrv_dirty_bitmap_meta_granularity

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-10-06 16:28:58 +02:00
Kevin Wolf
3045025991 block: Fix permissions after bdrv_reopen()
If we switch between read-only and read-write, the permissions that
image format drivers need on bs->file change, too. Make sure to update
the permissions during bdrv_reopen().

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2017-09-26 14:46:23 +02:00
Kevin Wolf
148eb13c84 block: Base permissions on rw state after reopen
When new permissions are calculated during bdrv_reopen(), they need to
be based on the state of the graph as it will be after the reopen has
completed, not on the current state of the involved nodes.

This patch makes bdrv_is_writable() optionally accept a BlockReopenQueue
from which the new flags are taken. This is then used for determining
the new bs->file permissions of format drivers as soon as we add the
code to actually pass a non-NULL reopen queue to the .bdrv_child_perm
callbacks.

While moving bdrv_is_writable(), make it static. It isn't used outside
block.c.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2017-09-26 14:46:23 +02:00
Kevin Wolf
e0995dc3da block: Add reopen_queue to bdrv_child_perm()
In the context of bdrv_reopen(), we'll have to look at the state of the
graph as it will be after the reopen. This interface addition is in
preparation for the change.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2017-09-26 14:46:23 +02:00
Paolo Bonzini
08e2c9f19c scsi: move block/scsi.h to include/scsi/constants.h
Complete the transition by renaming this header, which was
shared by block/iscsi.c and the SCSI emulation code.

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-09-19 14:09:31 +02:00
Paolo Bonzini
e5b5728cd3 scsi: move non-emulation specific code to scsi/
util/scsi.c includes some SCSI code that is shared by block/iscsi.c and
hw/scsi, but the introduction of the persistent reservation helper
will add many more instances of this.  There is also include/block/scsi.h,
which actually is not part of the core block layer.

The persistent reservation manager will also need a home.  A scsi/
directory provides one for both the aforementioned shared code and
the PR manager code.

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-09-19 14:09:11 +02:00
Peter Maydell
75be9a52b1 nbd patches for 2017-09-06
- Daniel P. Berrange: [0/2] Fix / skip recent iotests with LUKS driver
 - Eric Blake: [0/3] nbd: Use common read/write-all qio functions
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Merge remote-tracking branch 'remotes/ericb/tags/pull-nbd-2017-09-06' into staging

nbd patches for 2017-09-06

- Daniel P. Berrange: [0/2] Fix / skip recent iotests with LUKS driver
- Eric Blake: [0/3] nbd: Use common read/write-all qio functions

# gpg: Signature made Wed 06 Sep 2017 16:17:55 BST
# gpg:                using RSA key 0xA7A16B4A2527436A
# gpg: Good signature from "Eric Blake <eblake@redhat.com>"
# gpg:                 aka "Eric Blake (Free Software Programmer) <ebb9@byu.net>"
# gpg:                 aka "[jpeg image of size 6874]"
# Primary key fingerprint: 71C2 CC22 B1C4 6029 27D2  F3AA A7A1 6B4A 2527 436A

* remotes/ericb/tags/pull-nbd-2017-09-06:
  nbd: Use new qio_channel_*_all() functions
  io: Add new qio_channel_read{, v}_all_eof functions
  io: Yield rather than wait when already in coroutine
  iotests: blacklist 194 with the luks driver
  iotests: rewrite 192 to use _launch_qemu to fix LUKS support

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2017-09-07 17:53:59 +01:00
Eric Blake
030fa7f6f9 nbd: Use new qio_channel_*_all() functions
Rather than open-coding our own read/write-all functions, we
can make use of the recently-added qio code.  It slightly
changes the error message in one of the iotests.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20170905191114.5959-4-eblake@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
2017-09-06 10:11:54 -05:00
Manos Pitsidianakis
d8e7d87ec4 block: add throttle block filter driver
block/throttle.c uses existing I/O throttle infrastructure inside a
block filter driver. I/O operations are intercepted in the filter's
read/write coroutines, and referred to block/throttle-groups.c

The driver can be used with the syntax
-drive driver=throttle,file.filename=foo.qcow2,throttle-group=bar

which registers the throttle filter node with the ThrottleGroup 'bar'. The
given group must be created beforehand with object-add or -object.

Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Manos Pitsidianakis <el13635@mail.ntua.gr>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-09-06 10:12:02 +02:00
Manos Pitsidianakis
432d889e55 block: convert ThrottleGroup to object with QOM
ThrottleGroup is converted to an object. This will allow the future
throttle block filter drive easy creation and configuration of throttle
groups in QMP and cli.

A new QAPI struct, ThrottleLimits, is introduced to provide a shared
struct for all throttle configuration needs in QMP.

ThrottleGroups can be created via CLI as
    -object throttle-group,id=foo,x-iops-total=100,x-..
where x-* are individual limit properties. Since we can't add non-scalar
properties in -object this interface must be used instead. However,
setting these properties must be disabled after initialization because
certain combinations of limits are forbidden and thus configuration
changes should be done in one transaction. The individual properties
will go away when support for non-scalar values in CLI is implemented
and thus are marked as experimental.

ThrottleGroup also has a `limits` property that uses the ThrottleLimits
struct.  It can be used to create ThrottleGroups or set the
configuration in existing groups as follows:

{ "execute": "object-add",
  "arguments": {
    "qom-type": "throttle-group",
    "id": "foo",
    "props" : {
      "limits": {
          "iops-total": 100
      }
    }
  }
}
{ "execute" : "qom-set",
    "arguments" : {
        "path" : "foo",
        "property" : "limits",
        "value" : {
            "iops-total" : 99
        }
    }
}

This also means a group's configuration can be fetched with qom-get.

Signed-off-by: Manos Pitsidianakis <el13635@mail.ntua.gr>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-09-05 18:12:21 +02:00
Manos Pitsidianakis
c61791fc23 block: add aio_context field in ThrottleGroupMember
timer_cb() needs to know about the current Aio context of the throttle
request that is woken up. In order to make ThrottleGroupMember backend
agnostic, this information is stored in an aio_context field instead of
accessing it from BlockBackend.

Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Manos Pitsidianakis <el13635@mail.ntua.gr>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-09-05 16:47:52 +02:00
Manos Pitsidianakis
022cdc9f40 block: move ThrottleGroup membership to ThrottleGroupMember
This commit eliminates the 1:1 relationship between BlockBackend and
throttle group state.  Users will be able to create multiple throttle
nodes, each with its own throttle group state, in the future.  The
throttle group state cannot be per-BlockBackend anymore, it must be
per-throttle node. This is done by gathering ThrottleGroup membership
details from BlockBackendPublic into ThrottleGroupMember and refactoring
existing code to use the structure.

Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Manos Pitsidianakis <el13635@mail.ntua.gr>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-09-05 16:47:51 +02:00
Daniel P. Berrange
b461151ff3 block: document semantics of bdrv_co_preadv|pwritev
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 20170831105456.9558-1-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-09-05 11:07:02 +01:00
Daniel P. Berrange
64182a6b8b block: document semantics of bdrv_co_preadv|pwritev
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-09-05 11:40:34 +02:00
Manos Pitsidianakis
f7cc69b326 block: add default implementations for bdrv_co_get_block_status()
bdrv_co_get_block_status_from_file() and
bdrv_co_get_block_status_from_backing() set *file to bs->file and
bs->backing respectively, so that bdrv_co_get_block_status() can recurse
to them. Future block drivers won't have to duplicate code to implement
this.

Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Manos Pitsidianakis <el13635@mail.ntua.gr>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-09-04 18:31:13 +02:00
Manos Pitsidianakis
f024aee867 block: remove unused bdrv_media_changed
This function is not used anywhere, so remove it.

Markus Armbruster adds:
The i82078 floppy device model used to call bdrv_media_changed() to
implement its media change bit when backed by a host floppy.  This
went away in 21fcf36 "fdc: simplify media change handling".
Probably broke host floppy media change.  Host floppy pass-through
was dropped in commit f709623.  bdrv_media_changed() has never been
used for anything else.  Remove it.
(Source is Message-ID: <87y3ruaypm.fsf@dusky.pond.sub.org>)

Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Manos Pitsidianakis <el13635@mail.ntua.gr>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-09-04 18:31:13 +02:00
Manos Pitsidianakis
5a612c009e block: pass bdrv_* methods to bs->file by default in block filters
The following functions fail if bs->drv is a filter and does not
implement them:

bdrv_probe_blocksizes
bdrv_probe_geometry
bdrv_truncate
bdrv_has_zero_init
bdrv_get_info

Instead, the call should be passed to bs->file if it exists, to allow
filter drivers to support those methods without implementing them. This
commit makes `drv->is_filter = true` imply that these callbacks will be
forwarded to bs->file by default, so disabling support for these
functions must be done explicitly.

Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Manos Pitsidianakis <el13635@mail.ntua.gr>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-09-04 18:31:13 +02:00
Vladimir Sementsov-Ogievskiy
490dc5ed9b nbd/client: fix nbd_send_request to return int
Fix nbd_send_request to return int, as it returns a return value
of nbd_write (which is int), and the only user of nbd_send_request's
return value (nbd_co_send_request) consider it as int too.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20170804151440.320927-5-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2017-08-30 13:00:38 -05:00
Vladimir Sementsov-Ogievskiy
ba8456442b nbd/client: refactor nbd_receive_reply
Refactor nbd_receive_reply to return 1 on success, 0 on eof, when no
data was read and <0 for other cases, because returned size of read
data is not actually used.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20170804151440.320927-4-vsementsov@virtuozzo.com>
[eblake: tweak function comments]
Signed-off-by: Eric Blake <eblake@redhat.com>
2017-08-30 13:00:38 -05:00
Kevin Wolf
54a32bfec1 block: Allow reopen rw without BDRV_O_ALLOW_RDWR
BDRV_O_ALLOW_RDWR is a flag that tells whether qemu can internally
reopen a node read-write temporarily because the user requested
read-write for the top-level image, but qemu decided that read-only is
enough for this node (a backing file).

bdrv_reopen() is different, it is also used for cases where the user
changed their mind and wants to update the options. There is no reason
to forbid making a node read-write in that case.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
2017-08-08 15:19:16 +02:00
Paolo Bonzini
82346685b8 block: drop bdrv_set_key from BlockDriver
This is not used anymore since c01c214b69 ("block: remove all encryption
handling APIs", 2017-07-11).

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-08-08 14:37:00 +02:00
Kevin Wolf
d3c8c67469 block: Skip implicit nodes in query-block/blockstats
Commits 0db832f and 6cdbceb introduced the automatic insertion of filter
nodes above the top layer of mirror and commit block jobs. The
assumption made there was that since libvirt doesn't do node-level
management of the block layer yet, it shouldn't be affected by added
nodes.

This is true as far as commands issued by libvirt are concerned. It only
uses BlockBackend names to address nodes, so any operations it performs
still operate on the root of the tree as intended.

However, the assumption breaks down when you consider query commands,
which return data for the wrong node now. These commands also return
information on some child nodes (bs->file and/or bs->backing), which
libvirt does make use of, and which refer to the wrong nodes, too.

One of the consequences is that oVirt gets wrong information about the
image size and stops the VM in response as long as a mirror or commit
job is running:

https://bugzilla.redhat.com/show_bug.cgi?id=1470634

This patch fixes the problem by hiding the implicit nodes created
automatically by the mirror and commit block jobs in the output of
query-block and BlockBackend-based query-blockstats as long as the user
doesn't indicate that they are aware of those nodes by providing a node
name for them in the QMP command to start the block job.

The node-based commands query-named-block-nodes and query-blockstats
with query-nodes=true still show all nodes, including implicit ones.
This ensures that users that are capable of node-level management can
still access the full information; users that only know BlockBackends
won't use these commands.

Cc: qemu-stable@nongnu.org
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Tested-by: Eric Blake <eblake@redhat.com>
2017-07-24 15:06:04 +02:00
Paolo Bonzini
61124f03ab block: invoke .bdrv_drain callback in coroutine context and from AioContext
This will let the callback take a CoMutex in the next patch.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20170629132749.997-8-pbonzini@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
2017-07-17 11:28:15 +08:00
Eric Blake
081dd1fe36 nbd: Implement NBD_INFO_BLOCK_SIZE on client
The upstream NBD Protocol has defined a new extension to allow
the server to advertise block sizes to the client, as well as
a way for the client to inform the server whether it intends to
obey block sizes.

When using the block layer as the client, we will obey block
sizes; but when used as 'qemu-nbd -c' to hand off to the
kernel nbd module as the client, we are still waiting for the
kernel to implement a way for us to learn if it will honor
block sizes (perhaps by an addition to sysfs, rather than an
ioctl), as well as any way to tell the kernel what additional
block sizes to obey (NBD_SET_BLKSIZE appears to be accurate
for the minimum size, but preferred and maximum sizes would
probably be new ioctl()s), so until then, we need to make our
request for block sizes conditional.

When using ioctl(NBD_SET_BLKSIZE) to hand off to the kernel,
use the minimum block size as the sector size if it is larger
than 512, which also has the nice effect of cooperating with
(non-qemu) servers that don't do read-modify-write when
exposing a block device with 4k sectors; it might also allow
us to visit a file larger than 2T on a 32-bit kernel.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20170707203049.534-10-eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-07-14 12:04:42 +02:00
Eric Blake
3736cc5be3 nbd: Expose and debug more NBD constants
The NBD protocol has several constants defined in various extensions
that we are about to implement.  Expose them to the code, along with
an easy way to map various constants to strings during diagnostic
messages.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20170707203049.534-4-eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-07-14 12:04:41 +02:00
Eric Blake
004a89fce9 nbd: Create struct for tracking export info
The NBD Protocol is introducing some additional information
about exports, such as minimum request size and alignment, as
well as an advertised maximum request size.  It will be easier
to feed this information back to the block layer if we gather
all the information into a struct, rather than adding yet more
pointer parameters during negotiation.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20170707203049.534-2-eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-07-14 12:04:41 +02:00
Max Reitz
7ea37c3066 block: Add PreallocMode to bdrv_truncate()
For block drivers that just pass a truncate request to the underlying
protocol, we can now pass the preallocation mode instead of aborting if
it is not PREALLOC_MODE_OFF.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20170613202107.10125-3-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:45:01 +02:00
Max Reitz
8243ccb743 block: Add PreallocMode to BD.bdrv_truncate()
Add a PreallocMode parameter to the bdrv_truncate() function implemented
by each block driver. Currently, we always pass PREALLOC_MODE_OFF and no
driver accepts anything else.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20170613202107.10125-2-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:45:01 +02:00
Stefan Hajnoczi
90880ff107 block: add bdrv_measure() API
bdrv_measure() provides a conservative maximum for the size of a new
image.  This information is handy if storage needs to be allocated (e.g.
a SAN or an LVM volume) ahead of time.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20170705125738.8777-2-stefanha@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:45:00 +02:00
Vladimir Sementsov-Ogievskiy
615b5dcf2d block: release persistent bitmaps on inactivate
We should release them here to reload on invalidate cache.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20170628120530.31251-31-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:44:59 +02:00
Vladimir Sementsov-Ogievskiy
56f364e6d7 block/dirty-bitmap: add bdrv_remove_persistent_dirty_bitmap
Interface for removing persistent bitmap from its storage.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 20170628120530.31251-28-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:44:59 +02:00
Vladimir Sementsov-Ogievskiy
a3b52535e8 qmp: add x-debug-block-dirty-bitmap-sha256
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20170628120530.31251-26-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:44:59 +02:00
Vladimir Sementsov-Ogievskiy
67b792f5ed block: add bdrv_can_store_new_dirty_bitmap
This will be needed to check some restrictions before making bitmap
persistent in qmp-block-dirty-bitmap-add (this functionality will be
added by future patch)

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 20170628120530.31251-22-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:44:59 +02:00
Vladimir Sementsov-Ogievskiy
3dd10a06d1 block/dirty-bitmap: add bdrv_dirty_bitmap_next()
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 20170628120530.31251-19-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:44:58 +02:00
Vladimir Sementsov-Ogievskiy
a88b179fdb block: introduce persistent dirty bitmaps
New field BdrvDirtyBitmap.persistent means, that bitmap should be saved
by format driver in .bdrv_close and .bdrv_inactivate. No format driver
supports it for now.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20170628120530.31251-18-vsementsov@virtuozzo.com
[mreitz: Fixed indentation]
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:44:58 +02:00
Vladimir Sementsov-Ogievskiy
a0319aacd4 block/dirty-bitmap: add autoload field to BdrvDirtyBitmap
Mirror AUTO flag from Qcow2 bitmap in BdrvDirtyBitmap. This will be
needed in future, to save this flag back to Qcow2 for persistent
bitmaps.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20170628120530.31251-16-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:44:58 +02:00
Vladimir Sementsov-Ogievskiy
cb9ff6c25a block: new bdrv_reopen_bitmaps_rw interface
Add format driver handler, which should mark loaded read-only
bitmaps as 'IN_USE' in the image and unset read_only field in
corresponding BdrvDirtyBitmap's.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20170628120530.31251-14-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:44:58 +02:00
Vladimir Sementsov-Ogievskiy
d6883bc968 block/dirty-bitmap: add readonly field to BdrvDirtyBitmap
It will be needed in following commits for persistent bitmaps.
If bitmap is loaded from read-only storage (and we can't mark it
"in use" in this storage) corresponding BdrvDirtyBitmap should be
read-only.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20170628120530.31251-11-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:44:58 +02:00
Vladimir Sementsov-Ogievskiy
6bdc8b719a block/dirty-bitmap: add deserialize_ones func
Add bdrv_dirty_bitmap_deserialize_ones() function, which is needed for
qcow2 bitmap loading, to handle unallocated bitmap parts, marked as
all-ones.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 20170628120530.31251-7-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:44:57 +02:00
Vladimir Sementsov-Ogievskiy
ba06ff1a5c block: fix bdrv_dirty_bitmap_granularity signature
Make getter signature const-correct. This allows other functions with
const dirty bitmap parameter use bdrv_dirty_bitmap_granularity().

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-id: 20170628120530.31251-6-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:44:57 +02:00
Daniel P. Berrange
c01c214b69 block: remove all encryption handling APIs
Now that all encryption keys must be provided upfront via
the QCryptoSecret API and associated block driver properties
there is no need for any explicit encryption handling APIs
in the block layer. Encryption can be handled transparently
within the block driver. We only retain an API for querying
whether an image is encrypted or not, since that is a
potentially useful piece of metadata to report to the user.

Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 20170623162419.26068-18-berrange@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:44:56 +02:00
Daniel P. Berrange
0cb8d47ba9 block: deprecate "encryption=on" in favor of "encrypt.format=aes"
Historically the qcow & qcow2 image formats supported a property
"encryption=on" to enable their built-in AES encryption. We'll
soon be supporting LUKS for qcow2, so need a more general purpose
way to enable encryption, with a choice of formats.

This introduces an "encrypt.format" option, which will later be
joined by a number of other "encrypt.XXX" options. The use of
a "encrypt." prefix instead of "encrypt-" is done to facilitate
mapping to a nested QAPI schema at later date.

e.g. the preferred syntax is now

  qemu-img create -f qcow2 -o encrypt.format=aes demo.qcow2

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 20170623162419.26068-8-berrange@redhat.com
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:44:55 +02:00
Eric Blake
51b0a48888 block: Make bdrv_is_allocated_above() byte-based
We are gradually moving away from sector-based interfaces, towards
byte-based.  In the common case, allocation is unlikely to ever use
values that are not naturally sector-aligned, but it is possible
that byte-based values will let us be more precise about allocation
at the end of an unaligned file that can do byte-based access.

Changing the signature of the function to use int64_t *pnum ensures
that the compiler enforces that all callers are updated.  For now,
the io.c layer still assert()s that all callers are sector-aligned,
but that can be relaxed when a later patch implements byte-based
block status.  Therefore, for the most part this patch is just the
addition of scaling at the callers followed by inverse scaling at
bdrv_is_allocated().  But some code, particularly stream_run(),
gets a lot simpler because it no longer has to mess with sectors.
Leave comments where we can further simplify by switching to
byte-based iterations, once later patches eliminate the need for
sector-aligned operations.

For ease of review, bdrv_is_allocated() was tackled separately.

Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-07-10 13:18:07 +02:00
Eric Blake
d6a644bbfe block: Make bdrv_is_allocated() byte-based
We are gradually moving away from sector-based interfaces, towards
byte-based.  In the common case, allocation is unlikely to ever use
values that are not naturally sector-aligned, but it is possible
that byte-based values will let us be more precise about allocation
at the end of an unaligned file that can do byte-based access.

Changing the signature of the function to use int64_t *pnum ensures
that the compiler enforces that all callers are updated.  For now,
the io.c layer still assert()s that all callers are sector-aligned
on input and that *pnum is sector-aligned on return to the caller,
but that can be relaxed when a later patch implements byte-based
block status.  Therefore, this code adds usages like
DIV_ROUND_UP(,BDRV_SECTOR_SIZE) to callers that still want aligned
values, where the call might reasonbly give non-aligned results
in the future; on the other hand, no rounding is needed for callers
that should just continue to work with byte alignment.

For the most part this patch is just the addition of scaling at the
callers followed by inverse scaling at bdrv_is_allocated().  But
some code, particularly bdrv_commit(), gets a lot simpler because it
no longer has to mess with sectors; also, it is now possible to pass
NULL if the caller does not care how much of the image is allocated
beyond the initial offset.  Leave comments where we can further
simplify once a later patch eliminates the need for sector-aligned
requests through bdrv_is_allocated().

For ease of review, bdrv_is_allocated_above() will be tackled
separately.

Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-07-10 13:18:07 +02:00
Eric Blake
f6ac207893 backup: Switch block_backup.h to byte-based
We are gradually converting to byte-based interfaces, as they are
easier to reason about than sector-based.  Continue by converting
the public interface to backup jobs (no semantic change), including
a change to CowRequest to track by bytes instead of cluster indices.

Note that this does not change the difference between the public
interface (starting point, and size of the subsequent range) and
the internal interface (starting and end points).

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Xie Changlong <xiechanglong@cmss.chinamobile.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-07-10 13:18:06 +02:00
Eric Blake
e8a81e9cad block: Drop unused bdrv_round_sectors_to_clusters()
Now that the last user [mirror_iteration()] has converted to using
bytes, we no longer need a function to round sectors to clusters.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-07-10 13:18:06 +02:00
Eric Blake
d5254033da block: Simplify use of BDRV_BLOCK_RAW
The lone caller that cares about a return of BDRV_BLOCK_RAW
(namely, io.c:bdrv_co_get_block_status) completely replaces the
return value, so there is no point in passing BDRV_BLOCK_DATA.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-07-10 13:18:05 +02:00
Eric Blake
fb0d8654ff block: Add BDRV_BLOCK_EOF to bdrv_get_block_status()
Just as the block layer already sets BDRV_BLOCK_ALLOCATED as a
shortcut for subsequent operations, there are also some optimizations
that are made easier if we can quickly tell that *pnum will advance
us to the end of a file, via a new BDRV_BLOCK_EOF which gets set
by the block layer.

This just plumbs up the new bit; subsequent patches will make use
of it.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20170505021500.19315-2-eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
2017-06-30 21:48:06 +08:00
sochin.jiang
4172a00373 fix: avoid an infinite loop or a dangling pointer problem in img_commit
img_commit could fall into an infinite loop calling run_block_job() if
its blockjob fails on any I/O error, fix this already known problem.

Signed-off-by: sochin.jiang <sochin.jiang@huawei.com>
Message-id: 1497509253-28941-1-git-send-email-sochin.jiang@huawei.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-06-26 14:54:46 +02:00
Manos Pitsidianakis
f5a5ca7969 block: change variable names in BlockDriverState
Change the 'int count' parameter in *pwrite_zeros, *pdiscard related
functions (and some others) to 'int bytes', as they both refer to bytes.
This helps with code legibility.

Signed-off-by: Manos Pitsidianakis <el13635@mail.ntua.gr>
Message-id: 20170609101808.13506-1-el13635@mail.ntua.gr
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-06-26 14:54:46 +02:00
Kevin Wolf
c5f1ad429c block: Remove bdrv_aio_readv/writev/flush()
These functions are unused now.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-06-26 14:51:15 +02:00
Peter Maydell
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Merge remote-tracking branch 'remotes/famz/tags/docker-and-block-pull-request' into staging

# gpg: Signature made Fri 16 Jun 2017 01:18:46 BST
# gpg:                using RSA key 0xCA35624C6A9171C6
# gpg: Good signature from "Fam Zheng <famz@redhat.com>"
# gpg: WARNING: This key is not certified with sufficiently trusted signatures!
# gpg:          It is not certain that the signature belongs to the owner.
# Primary key fingerprint: 5003 7CB7 9706 0F76 F021  AD56 CA35 624C 6A91 71C6

* remotes/famz/tags/docker-and-block-pull-request: (23 commits)
  block: make accounting thread-safe
  block: split BlockAcctStats creation and setup
  block: introduce block_account_one_io
  block: protect modification of dirty bitmaps with a mutex
  migration/block: reset dirty bitmap before reading
  block: introduce dirty_bitmap_mutex
  block: protect tracked_requests and flush_queue with reqs_lock
  block: access write_gen with atomics
  block: use Stat64 for wr_highest_offset
  util: add stats64 module
  throttle-groups: protect throttled requests with a CoMutex
  throttle-groups: do not use qemu_co_enter_next
  throttle-groups: only start one coroutine from drained_begin
  block: access io_plugged with atomic ops
  block: access wakeup with atomic ops
  block: access serialising_in_flight with atomic ops
  block: access io_limits_disabled with atomic ops
  block: access quiesce_counter with atomic ops
  block: access copy_on_read with atomic ops
  docker: Add flex and bison to centos6 image
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2017-06-20 16:01:15 +01:00
Paolo Bonzini
5b50bf77ce block: make accounting thread-safe
I'm not trying too hard yet.  Later, with multiqueue support,
this may cause mutex contention or cacheline bouncing.

Cc: Alberto Garcia <berto@igalia.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20170605123908.18777-20-pbonzini@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
2017-06-16 07:55:00 +08:00
Paolo Bonzini
9caa6f3dbe block: split BlockAcctStats creation and setup
block_acct_destroy is called unconditionally in blk_delete, but there is
no BlockAcctStats function that is called unconditionally in blk_new.
Split block_acct_init in two, so that it will be possible to create a
QemuMutex in block_acct_init and destroy it in block_acct_cleanup.

Cc: Alberto Garcia <berto@igalia.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20170605123908.18777-19-pbonzini@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
2017-06-16 07:55:00 +08:00
Paolo Bonzini
b64bd51efa block: protect modification of dirty bitmaps with a mutex
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20170605123908.18777-17-pbonzini@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
2017-06-16 07:55:00 +08:00
Paolo Bonzini
2119882c7e block: introduce dirty_bitmap_mutex
It protects only the list of dirty bitmaps; in the next patch we will
also protect their content.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20170605123908.18777-15-pbonzini@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
2017-06-16 07:55:00 +08:00
Paolo Bonzini
3783fa3dd3 block: protect tracked_requests and flush_queue with reqs_lock
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20170605123908.18777-14-pbonzini@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
2017-06-16 07:55:00 +08:00
Paolo Bonzini
47fec59941 block: access write_gen with atomics
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20170605123908.18777-13-pbonzini@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
2017-06-16 07:55:00 +08:00
Paolo Bonzini
f7946da274 block: use Stat64 for wr_highest_offset
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20170605123908.18777-12-pbonzini@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
2017-06-16 07:55:00 +08:00
Paolo Bonzini
850d54a2a9 block: access io_plugged with atomic ops
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20170605123908.18777-7-pbonzini@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
2017-06-16 07:55:00 +08:00
Paolo Bonzini
e2a6ae7fe5 block: access wakeup with atomic ops
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20170605123908.18777-6-pbonzini@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
2017-06-16 07:55:00 +08:00
Paolo Bonzini
20fc71b25c block: access serialising_in_flight with atomic ops
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20170605123908.18777-5-pbonzini@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
2017-06-16 07:55:00 +08:00
Paolo Bonzini
414c2ec358 block: access quiesce_counter with atomic ops
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20170605123908.18777-3-pbonzini@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
2017-06-16 07:55:00 +08:00
Paolo Bonzini
d3faa13e5f block: access copy_on_read with atomic ops
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20170605123908.18777-2-pbonzini@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
2017-06-16 07:55:00 +08:00
Vladimir Sementsov-Ogievskiy
d1fdf257d5 nbd: rename read_sync and friends
Rename
  nbd_wr_syncv -> nbd_rwv
  read_sync -> nbd_read
  read_sync_eof -> nbd_read_eof
  write_sync -> nbd_write
  drop_sync -> nbd_drop

1. nbd_ prefix
   read_sync and write_sync are already shared, so it is good to have a
   namespace prefix. drop_sync will be shared, and read_sync_eof is
   related to read_sync, so let's rename them all.

2. _sync suffix
   _sync is related to the fact that nbd_wr_syncv doesn't return if a
   write to socket returns EAGAIN. The first implementation of
   nbd_wr_syncv (was wr_sync in 7a5ca8648b) just loops while getting
   EAGAIN, the current implementation yields in this case.
   Why we want to get rid of it:
   - it is normal for r/w functions to be synchronous, so having an
     additional suffix for it looks redundant (contrariwise, we have
     _aio suffix for async functions)
   - _sync suffix in block layer is used when function does flush (so
     using it for other thing is confusing a bit)
   - keep function names short after adding nbd_ prefix

3. for nbd_wr_syncv let's use more common notation 'rw'

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20170602150150.258222-2-vsementsov@virtuozzo.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-06-15 11:04:06 +02:00
Eric Blake
0c9390d978 nbd: Fix regression on resiliency to port scan
Back in qemu 2.5, qemu-nbd was immune to port probes (a transient
server would not quit, regardless of how many probe connections
came and went, until a connection actually negotiated).  But we
broke that in commit ee7d7aa when removing the return value to
nbd_client_new(), although that patch also introduced a bug causing
an assertion failure on a client that fails negotiation.  We then
made it worse during refactoring in commit 1a6245a (a segfault
before we could even assert); the (masked) assertion was cleaned
up in d3780c2 (still in 2.6), and just recently we finally fixed
the segfault ("nbd: Fully intialize client in case of failed
negotiation").  But that still means that ever since we added
TLS support to qemu-nbd, we have been vulnerable to an ill-timed
port-scan being able to cause a denial of service by taking down
qemu-nbd before a real client has a chance to connect.

Since negotiation is now handled asynchronously via coroutines,
we no longer have a synchronous point of return by re-adding a
return value to nbd_client_new().  So this patch instead wires
things up to pass the negotiation status through the close_fn
callback function.

Simple test across two terminals:
$ qemu-nbd -f raw -p 30001 file
$ nmap 127.0.0.1 -p 30001 && \
  qemu-io -c 'r 0 512' -f raw nbd://localhost:30001

Note that this patch does not change what constitutes successful
negotiation (thus, a client must enter transmission phase before
that client can be considered as a reason to terminate the server
when the connection ends).  Perhaps we may want to tweak things
in a later patch to also treat a client that uses NBD_OPT_ABORT
as being a 'successful' negotiation (the client correctly talked
the NBD protocol, and informed us it was not going to use our
export after all), but that's a discussion for another day.

Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1451614

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20170608222617.20376-1-eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-06-15 11:04:05 +02:00
Vladimir Sementsov-Ogievskiy
be41c100c0 nbd/client.c: use errp instead of LOG
Move to modern errp scheme from just LOGging errors.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20170526110913.89098-1-vsementsov@virtuozzo.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-06-06 20:18:36 +02:00
Vladimir Sementsov-Ogievskiy
f260956536 nbd: add errp parameter to nbd_wr_syncv()
Will be used in following patch to provide actual error message in
some cases.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20170516094533.6160-4-vsementsov@virtuozzo.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-06-06 20:18:36 +02:00
Juan Quintela
5e22479ae2 migration: Create include for migration snapshots
Start removing migration code from sysemu/sysemu.h.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2017-06-01 18:49:23 +02:00
Stefan Hajnoczi
0748b3526e Block layer patches
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Merge remote-tracking branch 'kwolf/tags/for-upstream' into staging

Block layer patches

# gpg: Signature made Mon 29 May 2017 03:34:59 PM BST
# gpg:                using RSA key 0x7F09B272C88F2FD6
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>"
# Primary key fingerprint: DC3D EB15 9A9A F95D 3D74  56FE 7F09 B272 C88F 2FD6

* kwolf/tags/for-upstream:
  block/file-*: *_parse_filename() and colons
  block: Fix backing paths for filenames with colons
  block: Tweak error message related to qemu-img amend
  qemu-img: Fix leakage of options on error
  qemu-img: copy *key-secret opts when opening newly created files
  qemu-img: introduce --target-image-opts for 'convert' command
  qemu-img: fix --image-opts usage with dd command
  qemu-img: add support for --object with 'dd' command
  qemu-img: Fix documentation of convert
  qcow2: remove extra local_error variable
  mirror: Drop permissions on s->target on completion
  nvme: Add support for Controller Memory Buffers
  iotests: 147: Don't test inet6 if not available
  qemu-iotests: Test streaming with missing job ID
  stream: fix crash in stream_start() when block_job_create() fails

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-05-30 14:15:15 +01:00
Max Reitz
03c320d803 block/file-*: *_parse_filename() and colons
The file drivers' *_parse_filename() implementations just strip the
optional protocol prefix off the filename. However, for e.g.
"file:foo:bar", this would lead to "foo:bar" being stored as the BDS's
filename which looks like it should be managed using the "foo" protocol.
This is especially troublesome if you then try to resolve a backing
filename based on "foo:bar".

This issue can only occur if the stripped part is a relative filename
("file:/foo:bar" will be shortened to "/foo:bar" and having a slash
before the first colon means that "/foo" is not recognized as a protocol
part). Therefore, we can easily fix it by prepending "./" to such
filenames.

Before this patch:
$ ./qemu-img create -f qcow2 backing.qcow2 64M
Formatting 'backing.qcow2', fmt=qcow2 size=67108864 encryption=off
    cluster_size=65536 lazy_refcounts=off refcount_bits=16
$ ./qemu-img create -f qcow2 -b backing.qcow2 file🔝image.qcow2
Formatting 'file🔝image.qcow2', fmt=qcow2 size=67108864
    backing_file=backing.qcow2 encryption=off cluster_size=65536
    lazy_refcounts=off refcount_bits=16
$ ./qemu-io file🔝image.qcow2
can't open device file🔝image.qcow2: Could not open backing file:
    Unknown protocol 'top'

After this patch:
$ ./qemu-io file🔝image.qcow2
[no error]

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20170522195217.12991-3-mreitz@redhat.com
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-05-29 15:39:54 +02:00
Paolo Bonzini
eb05e011e2 blockjob: use deferred_to_main_loop to indicate the coroutine has ended
All block jobs are using block_job_defer_to_main_loop as the final
step just before the coroutine terminates.  At this point,
block_job_enter should do nothing, but currently it restarts
the freed coroutine.

Now, the job->co states should probably be changed to an enum
(e.g. BEFORE_START, STARTED, YIELDED, COMPLETED) subsuming
block_job_started, job->deferred_to_main_loop and job->busy.
For now, this patch eliminates the problematic reenter by
removing the reset of job->deferred_to_main_loop (which served
no purpose, as far as I could see) and checking the flag in
block_job_enter.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 20170508141310.8674-12-pbonzini@redhat.com
Signed-off-by: Jeff Cody <jcody@redhat.com>
2017-05-24 16:38:51 -04:00
Paolo Bonzini
f321dcb57f blockjob: introduce block_job_pause/resume_all
Remove use of block_job_pause/resume from outside blockjob.c, thus
making them static.  The new functions are used by the block layer,
so place them in blockjob_int.h.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Message-id: 20170508141310.8674-5-pbonzini@redhat.com
Signed-off-by: Jeff Cody <jcody@redhat.com>
2017-05-24 16:38:51 -04:00
Paolo Bonzini
05b0d8e3b8 blockjob: introduce block_job_early_fail
Outside blockjob.c, block_job_unref is only used when a block job fails
to start, and block_job_ref is not used at all.  The reference counting
thus is pretty well hidden.  Introduce a separate function to be used
by block jobs; because block_job_ref and block_job_unref now become
static, move them earlier in blockjob.c.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Message-id: 20170508141310.8674-4-pbonzini@redhat.com
Signed-off-by: Jeff Cody <jcody@redhat.com>
2017-05-24 16:38:51 -04:00
Paolo Bonzini
9f086abbe4 blockjob: remove iostatus_reset callback
This is unused since commit 66a0fae ("blockjob: Don't touch BDS iostatus",
2016-05-19).

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Message-id: 20170508141310.8674-3-pbonzini@redhat.com
Signed-off-by: Jeff Cody <jcody@redhat.com>
2017-05-24 16:38:51 -04:00
Stefan Hajnoczi
b54933eed5 -----BEGIN PGP SIGNATURE-----
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Merge tag 'block-pull-request' into staging

# gpg: Signature made Fri 12 May 2017 10:37:12 AM EDT
# gpg:                using RSA key 0x9CA4ABB381AB73C8
# gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>"
# gpg:                 aka "Stefan Hajnoczi <stefanha@gmail.com>"
# Primary key fingerprint: 8695 A8BF D3F9 7CDA AC35  775A 9CA4 ABB3 81AB 73C8

* tag 'block-pull-request':
  aio: add missing aio_notify() to aio_enable_external()
  block: Simplify BDRV_BLOCK_RAW recursion
  coroutine: remove GThread implementation

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-05-12 10:39:23 -04:00
Stefan Hajnoczi
321d1dba8b aio: add missing aio_notify() to aio_enable_external()
The main loop uses aio_disable_external()/aio_enable_external() to
temporarily disable processing of external AioContext clients like
device emulation.

This allows monitor commands to quiesce I/O and prevent the guest from
submitting new requests while a monitor command is in progress.

The aio_enable_external() API is currently broken when an IOThread is in
aio_poll() waiting for fd activity when the main loop re-enables
external clients.  Incrementing ctx->external_disable_cnt does not wake
the IOThread from ppoll(2) so fd processing remains suspended and leads
to unresponsive emulated devices.

This patch adds an aio_notify() call to aio_enable_external() so the
IOThread is kicked out of ppoll(2) and will re-arm the file descriptors.

The bug can be reproduced as follows:

  $ qemu -M accel=kvm -m 1024 \
         -object iothread,id=iothread0 \
         -device virtio-scsi-pci,iothread=iothread0,id=virtio-scsi-pci0 \
         -drive if=none,id=drive0,aio=native,cache=none,format=raw,file=test.img \
         -device scsi-hd,id=scsi-hd0,drive=drive0 \
         -qmp tcp::5555,server,nowait

  $ scripts/qmp/qmp-shell localhost:5555
  (qemu) blockdev-snapshot-sync device=drive0 snapshot-file=sn1.qcow2
         mode=absolute-paths format=qcow2

After blockdev-snapshot-sync completes the SCSI disk will be
unresponsive.  This leads to request timeouts inside the guest.

Reported-by: Qianqian Zhu <qizhu@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20170508180705.20609-1-stefanha@redhat.com
Suggested-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-05-12 10:36:46 -04:00
Eric Blake
4c41cb4955 block: Update comments on BDRV_BLOCK_* meanings
We had some conflicting documentation: a nice 8-way table that
described all possible combinations of DATA, ZERO, and
OFFSET_VALID, contrasted with text that implied that OFFSET_VALID
always meant raw data could be read directly.  Furthermore, the
text refers a lot to bs->file, even though the interface was
updated back in 67a0fd2a to let the driver pass back a specific
BDS (not necessarily bs->file).  As the 8-way table is the
intended semantics, simplify the rest of the text to get rid of
the confusion.

ALLOCATED is always set by the block layer for convenience (drivers
do not have to worry about it).  RAW is used only internally, but
by more than the raw driver.  Document these additional items on
the driver callback.

Suggested-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20170507000552.20847-4-eblake@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-05-11 14:28:06 +02:00
Kevin Wolf
9c5e6594f1 block: Fix write/resize permissions for inactive images
Format drivers for inactive nodes don't need write/resize permissions on
their bs->file and can share write/resize with another VM (in fact, this
is the whole point of keeping images inactive). Represent this fact in
the op blocker system, so that image locking does the right thing
without special-casing inactive images.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2017-05-11 12:08:24 +02:00
Kevin Wolf
cfa1a5723f block: Drop permissions when migration completes
With image locking, permissions affect other qemu processes as well. We
want to be sure that the destination can run, so let's drop permissions
on the source when migration completes.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2017-05-11 12:08:24 +02:00
Kevin Wolf
4417ab7adf block: New BdrvChildRole.activate() for blk_resume_after_migration()
Instead of manually calling blk_resume_after_migration() in migration
code after doing bdrv_invalidate_cache_all(), integrate the BlockBackend
activation with cache invalidation into a single function. This is
achieved with a new callback in BdrvChildRole that is called by
bdrv_invalidate_cache_all().

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2017-05-11 12:08:24 +02:00
Fam Zheng
5a9347c673 block: Add, parse and store "force-share" option
Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-05-11 11:02:38 +02:00
Fam Zheng
5176196c32 block: Make bdrv_perm_names public
It can be used outside of block.c for making user friendly messages.

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-05-11 11:02:38 +02:00
Markus Armbruster
bd269ebc82 sockets: Limit SocketAddressLegacy to external interfaces
SocketAddressLegacy is a simple union, and simple unions are awkward:
they have their variant members wrapped in a "data" object on the
wire, and require additional indirections in C.  SocketAddress is the
equivalent flat union.  Convert all users of SocketAddressLegacy to
SocketAddress, except for existing external interfaces.

See also commit fce5d53..9445673 and 85a82e8..c5f1ae3.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1493192202-3184-7-git-send-email-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[Minor editing accident fixed, commit message and a comment tweaked]

Signed-off-by: Markus Armbruster <armbru@redhat.com>
2017-05-09 09:14:40 +02:00
Klim Kireev
d4a7f45ec9 block: fix obvious coding style mistakes in block_int.h
Signed-off-by: Klim Kireev <proffk@virtuozzo.mipt.ru>
Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Kevin Wolf <kwolf@redhat.com>
CC: Max Reitz <mreitz@redhat.com>
Message-id: 1491405505-31620-2-git-send-email-den@openvz.org
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-04-28 16:02:03 +02:00
Max Reitz
4bff28b81a block: Add errp to BD.bdrv_truncate()
Add an Error parameter to the block drivers' bdrv_truncate() interface.
If a block driver does not set this in case of an error, the generic
bdrv_truncate() implementation will do so.

Where it is obvious, this patch also makes some block drivers set this
value.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20170328205129.15138-4-mreitz@redhat.com
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-04-28 16:02:03 +02:00
Max Reitz
ed3d2ec98a block: Add errp to b{lk,drv}_truncate()
For one thing, this allows us to drop the error message generation from
qemu-img.c and blockdev.c and instead have it unified in
bdrv_truncate().

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20170328205129.15138-3-mreitz@redhat.com
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-04-28 16:02:02 +02:00
Jeff Cody
45803a0396 block: introduce bdrv_can_set_read_only()
Introduce check function for setting read_only flags.  Will return < 0 on
error, with appropriate Error value set.  Does not alter any flags.

Signed-off-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: e2bba34ac3bc76a0c42adc390413f358ae0566e8.1491597120.git.jcody@redhat.com
2017-04-24 15:09:33 -04:00
Jeff Cody
e2b8247a32 block: do not set BDS read_only if copy_on_read enabled
A few block drivers will set the BDS read_only flag from their
.bdrv_open() function.  This means the bs->read_only flag could
be set after we enable copy_on_read, as the BDRV_O_COPY_ON_READ
flag check occurs prior to the call to bdrv->bdrv_open().

This adds an error return to bdrv_set_read_only(), and an error will be
return if we try to set the BDS to read_only while copy_on_read is
enabled.

This patch also changes the behavior of vvfat.  Before, vvfat could
override the drive 'readonly' flag with its own, internal 'rw' flag.

For instance, this -drive parameter would result in a writable image:

"-drive format=vvfat,dir=/tmp/vvfat,rw,if=virtio,readonly=on"

This is not correct.  Now, attempting to use the above -drive parameter
will result in an error (i.e., 'rw' is incompatible with 'readonly=on').

Signed-off-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 0c5b4c1cc2c651471b131f21376dfd5ea24d2196.1491597120.git.jcody@redhat.com
2017-04-24 15:09:33 -04:00
Jeff Cody
fe5241bfe3 block: add bdrv_set_read_only() helper function
We have a helper wrapper for checking for the BDS read_only flag,
add a helper wrapper to set the read_only flag as well.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 9b18972d05f5fa2ac16c014f0af98d680553048d.1491597120.git.jcody@redhat.com
2017-04-24 15:09:33 -04:00
Fam Zheng
78bbd910bb block: Make errp the last parameter of commit_active_start
Signed-off-by: Fam Zheng <famz@redhat.com>
Message-Id: <20170421122710.15373-9-famz@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2017-04-24 09:13:44 +02:00
Fam Zheng
9217283dc8 block: Make errp the last parameter of bdrv_img_create
Signed-off-by: Fam Zheng <famz@redhat.com>
Message-Id: <20170421122710.15373-6-famz@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2017-04-24 09:12:59 +02:00
Fam Zheng
91af091f92 block: Drain BH in bdrv_drained_begin
During block job completion, nothing is preventing
block_job_defer_to_main_loop_bh from being called in a nested
aio_poll(), which is a trouble, such as in this code path:

    qmp_block_commit
      commit_active_start
        bdrv_reopen
          bdrv_reopen_multiple
            bdrv_reopen_prepare
              bdrv_flush
                aio_poll
                  aio_bh_poll
                    aio_bh_call
                      block_job_defer_to_main_loop_bh
                        stream_complete
                          bdrv_reopen

block_job_defer_to_main_loop_bh is the last step of the stream job,
which should have been "paused" by the bdrv_drained_begin/end in
bdrv_reopen_multiple, but it is not done because it's in the form of a
main loop BH.

Similar to why block jobs should be paused between drained_begin and
drained_end, BHs they schedule must be excluded as well.  To achieve
this, this patch forces draining the BH in BDRV_POLL_WHILE.

As a side effect this fixes a hang in block_job_detach_aio_context
during system_reset when a block job is ready:

    #0  0x0000555555aa79f3 in bdrv_drain_recurse
    #1  0x0000555555aa825d in bdrv_drained_begin
    #2  0x0000555555aa8449 in bdrv_drain
    #3  0x0000555555a9c356 in blk_drain
    #4  0x0000555555aa3cfd in mirror_drain
    #5  0x0000555555a66e11 in block_job_detach_aio_context
    #6  0x0000555555a62f4d in bdrv_detach_aio_context
    #7  0x0000555555a63116 in bdrv_set_aio_context
    #8  0x0000555555a9d326 in blk_set_aio_context
    #9  0x00005555557e38da in virtio_blk_data_plane_stop
    #10 0x00005555559f9d5f in virtio_bus_stop_ioeventfd
    #11 0x00005555559fa49b in virtio_bus_stop_ioeventfd
    #12 0x00005555559f6a18 in virtio_pci_stop_ioeventfd
    #13 0x00005555559f6a18 in virtio_pci_reset
    #14 0x00005555559139a9 in qdev_reset_one
    #15 0x0000555555916738 in qbus_walk_children
    #16 0x0000555555913318 in qdev_walk_children
    #17 0x0000555555916738 in qbus_walk_children
    #18 0x00005555559168ca in qemu_devices_reset
    #19 0x000055555581fcbb in pc_machine_reset
    #20 0x00005555558a4d96 in qemu_system_reset
    #21 0x000055555577157a in main_loop_should_exit
    #22 0x000055555577157a in main_loop
    #23 0x000055555577157a in main

The rationale is that the loop in block_job_detach_aio_context cannot
make any progress in pausing/completing the job, because bs->in_flight
is 0, so bdrv_drain doesn't process the block_job_defer_to_main_loop
BH. With this patch, it does.

Reported-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
Message-Id: <20170418143044.12187-3-famz@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Tested-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
2017-04-18 22:56:28 +08:00
Fam Zheng
052a75721f block: Introduce bdrv_coroutine_enter
Signed-off-by: Fam Zheng <famz@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
2017-04-11 20:07:15 +08:00
Fam Zheng
8865852e00 async: Introduce aio_co_enter
They start the coroutine on the specified context.

Signed-off-by: Fam Zheng <famz@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
2017-04-11 20:07:15 +08:00
Fam Zheng
14e9559f46 block: Make bdrv_parent_drained_begin/end public
Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
2017-04-11 20:07:15 +08:00
Kevin Wolf
d35ff5e6b3 block: Ignore guest dev permissions during incoming migration
Usually guest devices don't like other writers to the same image, so
they use blk_set_perm() to prevent this from happening. In the migration
phase before the VM is actually running, though, they don't have a
problem with writes to the image. On the other hand, storage migration
needs to be able to write to the image in this phase, so the restrictive
blk_set_perm() call of qdev devices breaks it.

This patch flags all BlockBackends with a qdev device as
blk->disable_perm during incoming migration, which means that the
requested permissions are stored in the BlockBackend, but not actually
applied to its root node yet.

Once migration has finished and the VM should be resumed, the
permissions are applied. If they cannot be applied (e.g. because the NBD
server used for block migration hasn't been shut down), resuming the VM
fails.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Tested-by: Kashyap Chamarthy <kchamart@redhat.com>
2017-04-07 14:44:05 +02:00
Fam Zheng
c1cef67251 block: Always call bdrv_child_check_perm first
bdrv_child_set_perm alone is not very usable because the caller must
call bdrv_child_check_perm first. This is already encapsulated
conveniently in bdrv_child_try_set_perm, so remove the other prototypes
from the header and fix the one wrong caller, block/mirror.c.

Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-03-17 12:54:06 +01:00
Kevin Wolf
5fe31c25cc block: Fix error handling in bdrv_replace_in_backing_chain()
When adding an Error parameter, bdrv_replace_in_backing_chain() would
become nothing more than a wrapper around change_parent_backing_link().
So make the latter public, renamed as bdrv_replace_node(), and remove
bdrv_replace_in_backing_chain().

Most of the callers just remove a node from the graph that they just
inserted, so they can use &error_abort, but completion of a mirror job
with 'replaces' set can actually fail.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2017-03-07 14:53:28 +01:00
Kevin Wolf
46181129ea block: Ignore multiple children in bdrv_check_update_perm()
change_parent_backing_link() will need to update multiple BdrvChild
objects at once. Checking permissions reference by reference doesn't
work because permissions need to be consistent only with all parents
moved to the new child.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2017-03-07 14:53:28 +01:00
Kevin Wolf
b2c2832c61 block: Add Error parameter to bdrv_append()
Aborting on error in bdrv_append() isn't correct. This patch fixes it
and lets the callers handle failures.

Test case 085 needs a reference output update. This is caused by the
reversed order of bdrv_set_backing_hd() and change_parent_backing_link()
in bdrv_append(): When the backing file of the new node is set, the
parent nodes are still pointing to the old top, so the backing blocker
is now initialised with the node name rather than the BlockBackend name.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2017-02-28 20:47:51 +01:00
Kevin Wolf
12fa4af61f block: Add Error parameter to bdrv_set_backing_hd()
Not all callers of bdrv_set_backing_hd() know for sure that attaching
the backing file will be allowed by the permission system. Return the
error from the function rather than aborting.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2017-02-28 20:47:51 +01:00
Kevin Wolf
0db832f42e commit: Add filter-node-name to block-commit
Management tools need to be able to know about every node in the graph
and need a way to address them. Changing the graph structure was okay
because libvirt doesn't really manage the node level yet, but future
libvirt versions need to deal with both new and old version of qemu.

This new option to blockdev-commit allows the client to set a node-name
for the automatically inserted filter driver, and at the same time
serves as a witness for a future libvirt that this version of qemu does
automatically insert a filter driver.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2017-02-28 20:47:50 +01:00
Kevin Wolf
6cdbceb12c mirror: Add filter-node-name to blockdev-mirror
Management tools need to be able to know about every node in the graph
and need a way to address them. Changing the graph structure was okay
because libvirt doesn't really manage the node level yet, but future
libvirt versions need to deal with both new and old version of qemu.

This new option to blockdev-mirror allows the client to set a node-name
for the automatically inserted filter driver, and at the same time
serves as a witness for a future libvirt that this version of qemu does
automatically insert a filter driver.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
2017-02-28 20:47:50 +01:00
Kevin Wolf
bbc02b90bc blockjob: Factor out block_job_remove_all_bdrv()
In some cases, we want to remove op blockers on intermediate nodes
before the whole block job transaction has completed (because they block
restoring the final graph state during completion). Provide a function
for this.

The whole block job lifecycle is a bit messed up and it's hard to
actually do all things in the right order, but I'll leave simplifying
this for another day.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2017-02-28 20:40:37 +01:00
Kevin Wolf
db95dbba3b block: BdrvChildRole.attach/detach() callbacks
Backing files are somewhat special compared to other kinds of children
because they are attached and detached using bdrv_set_backing_hd()
rather than the normal set of functions, which does a few more things
like setting backing blockers, toggling the BDRV_O_NO_BACKING flag,
setting parent_bs->backing_file, etc.

These special features are a reason why change_parent_backing_link()
can't handle backing files yet. With abstracting the additional features
into .attach/.detach callbacks, we get a step closer to a function that
can actually deal with this.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
2017-02-28 20:40:37 +01:00
Kevin Wolf
76d554e20b blockjob: Add permissions to block_job_add_bdrv()
Block jobs don't actually do I/O through the the reference they create
with block_job_add_bdrv(), but they might want to use the permisssion
system to express what the block job does to intermediate nodes. This
adds permissions to block_job_add_bdrv() to provide the means to request
permissions.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
2017-02-28 20:40:37 +01:00
Kevin Wolf
26de9438c1 block: Add BdrvChildRole.stay_at_node
When the parents' child links are updated in bdrv_append() or
bdrv_replace_in_backing_chain(), this should affect all child links of
BlockBackends or other nodes, but not on child links held for other
purposes (like for setting permissions). This patch allows to control
the behaviour per BdrvChildRole.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
2017-02-28 20:40:37 +01:00
Kevin Wolf
b541155587 block: Add BdrvChildRole.get_parent_desc()
For meaningful error messages in the permission system, we need to get
some human-readable description of the parent of a BdrvChild.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
2017-02-28 20:40:37 +01:00
Kevin Wolf
c6cc12bfa7 blockjob: Add permissions to block_job_create()
This functions creates a BlockBackend internally, so the block jobs need
to tell it what they want to do with the BB.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
2017-02-28 20:40:37 +01:00
Kevin Wolf
39829a01ae block: Allow error return in BlockDevOps.change_media_cb()
Some devices allow a media change between read-only and read-write
media. They need to adapt the permissions in their .change_media_cb()
implementation, which can fail. So add an Error parameter to the
function.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
2017-02-28 20:40:36 +01:00
Kevin Wolf
55880601d8 block: Add BDRV_O_RESIZE for blk_new_open()
blk_new_open() is a convenience function that processes flags rather
than QDict options as a simple way to just open an image file.

In order to keep it convenient in the future, it must automatically
request the necessary permissions. This can easily be inferred from the
flags for read and write, but we need another flag that tells us whether
to get the resize permission.

We can't just always request it because that means that no block jobs
can run on the resulting BlockBackend (which is something that e.g.
qemu-img commit wants to do), but we also can't request it never because
most of the .bdrv_create() implementations call blk_truncate().

The solution is to introduce another flag that is passed by all users
that want to resize the image.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2017-02-28 20:40:36 +01:00
Kevin Wolf
91ef38257a vvfat: Implement .bdrv_child_perm()
vvfat is the last remaining driver that can have children, but doesn't
implement .bdrv_child_perm() yet. The default handlers aren't suitable
here, so let's implement a very simple driver-specific one that protects
the internal child from being used by other users as good as our
permissions permit.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
2017-02-28 20:40:36 +01:00
Kevin Wolf
6b1a044afb block: Default .bdrv_child_perm() for format drivers
Almost all format drivers have the same characteristics as far as
permissions are concerned: They have one or more children for storing
their own data and, more importantly, metadata (can be written to and
grow even without external write requests, must be protected against
other writers and present consistent data) and optionally a backing file
(this is just data, so like for a filter, it only depends on what the
parent nodes need).

This provides a default implementation that can be shared by most of
our format drivers.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2017-02-28 20:40:36 +01:00
Kevin Wolf
6a1b9ee152 block: Default .bdrv_child_perm() for filter drivers
Most filters need permissions related to read and write for their
children, but only if the node has a parent that wants to use the same
operation on the filter. The same is true for resize.

This adds a default implementation that simply forwards all necessary
permissions to all children of the node and leaves the other permissions
unchanged.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2017-02-28 20:40:36 +01:00
Kevin Wolf
33a610c398 block: Involve block drivers in permission granting
In many cases, the required permissions of one node on its children
depend on what its parents require from it. For example, the raw format
or most filter drivers only need to request consistent reads if that's
something that one of their parents wants.

In order to achieve this, this patch introduces two new BlockDriver
callbacks. The first one lets drivers first check (recursively) whether
the requested permissions can be set; the second one actually sets the
new permission bitmask.

Also add helper functions that drivers can use in their implementation
of the callbacks to update their permissions on a specific child.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2017-02-28 20:40:36 +01:00
Kevin Wolf
d5e6f437c5 block: Let callers request permissions when attaching a child node
When attaching a node as a child to a new parent, the required and
shared permissions for this parent are checked against all other parents
of the node now, and an error is returned if there is a conflict.

This allows error returns to a function that previously always
succeeded, and the same is true for quite a few callers and their
callers. Converting all of them within the same patch would be too much,
so for now everyone tells that they don't need any permissions and allow
everyone else to do anything. This way we can use &error_abort initially
and convert caller by caller to pass actual permission requirements and
implement error handling.

All these places are marked with FIXME comments and it will be the job
of the next patches to clean them up again.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
2017-02-28 20:40:36 +01:00
Kevin Wolf
8b2ff5291f block: Add Error argument to bdrv_attach_child()
It will have to return an error soon, so prepare the callers for it.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
2017-02-28 20:40:35 +01:00
Kevin Wolf
7006c9a761 block: Add op blocker permission constants
This patch defines the permission categories that will be used by the
new op blocker system.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
2017-02-28 20:40:35 +01:00
Kevin Wolf
680c7f9606 block: Add bdrv_new_open_driver()
This function allows to create more or less normal BlockDriverStates
even for BlockDrivers that aren't globally registered (e.g. helper
filters for block jobs).

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2017-02-24 16:09:23 +01:00
Kevin Wolf
52cdbc5869 block: Pass BdrvChild to bdrv_truncate()
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2017-02-24 16:09:23 +01:00
Paolo Bonzini
91bcea4899 block: document fields protected by AioContext lock
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 20170213135235.12274-19-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-02-21 11:39:40 +00:00
Paolo Bonzini
a153bf52b3 aio-posix: partially inline aio_dispatch into aio_poll
This patch prepares for the removal of unnecessary lockcnt inc/dec pairs.
Extract the dispatching loop for file descriptor handlers into a new
function aio_dispatch_handlers, and then inline aio_dispatch into
aio_poll.

aio_dispatch can now become void.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 20170213135235.12274-17-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-02-21 11:39:39 +00:00