Commit Graph

733 Commits

Author SHA1 Message Date
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
65a0e3e842 -----BEGIN PGP SIGNATURE-----
Version: GnuPG v2
 
 iQEtBAABCAAXBQJZQyPmEBxmYW16QHJlZGhhdC5jb20ACgkQyjViTGqRccaWrgf/
 SCAHpi4gzWbr7AN03jP16Qy/kqNik6F7LTNSqrRbvBPb3TNchDd4z44SAghK5m/r
 +IlYQc20sBZ60tRHIHAUSF2WNcea2pj1v3ZVgjrI7hiJ3DXPiqqt/dAR/W/BLIDO
 tAHAVF6Pnrjm9DC4d2zATLDHvcHMzWOsnePh7XcOm44REbwUr3GDg6bf2+j+5yfS
 9ewmXfh8z4w1IvSn+f5B+IeCvGvJNA1D55dqcGo8Ivlg9PnElziXFaXO2s7UiLIM
 mF3eTSIbJQNNN+E+0lpRpnqQiq+Txxggu61Q4f8bOTBhEOPa3etj1ydnXMVbvX25
 6SUuBfGh51tyOIZOJz3GtA==
 =9b+J
 -----END PGP SIGNATURE-----

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
-----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2.0.22 (GNU/Linux)
 
 iQIcBAABAgAGBQJZLDGTAAoJEH8JsnLIjy/WjY0P/jtXF+SQKs9H695Uy+U+EUr5
 9w+lYTfjHXTUx9F5AKT4OAMww/uWSG5ywG8FZD8AJZyt1B8piDrSA7sW5YYgWCV4
 XD1HMzN6pasVGrchzgfBSW/K9BgUlvBEjqFrLCNVii0osa68J7vX3uJsLyRA+yPo
 ijFseJaB/b0KnAPG9JqHXc4DVQgU2IhZH3ZsgE6Utb+KUrm8/veiORhWQboBbfCW
 eyTF+YWee/rI+up4nKn9+Le57EUXWr3Y50BBxFZw1/4wQbv0WEhOIbl/Z4ggxNRR
 VoyXGMqOIZFlGQ7bGxDawuEwGKfcOFFEHj3rhPrs7RPnod/6X8Vxm0rAr2GNZoOW
 9tLMQKe4HLo3kVwX65AhzWd/WMukAd0MC/0oaULOjiAEdlWjflyEhx9H9uYefl5x
 kn77ZqQqIEL4aCYRBLJn9oJV3CIZbSd6cuKC9UPuXAwD8XDWTXUzT/aDMJUnfij7
 vhS1qks1Wyk37wIjTuuERwrr0K6y8e3De30NeU6LqQuzXvJ1MYSp49BA1FCgHfmT
 x5RWbTSjLdjZiIo7biE2dSwdOtsxsnuxX19utqfGqOmegNU7LykRtu6mFh9kJhNe
 5ladt1Mu//puZLQ/q4RH/J0pwkuS/OVrS3LBobcggPGHhUIiHhdNUI73bb7BK0+9
 ME5DGLm4/c/REB3Lidr9
 =kkU0
 -----END PGP SIGNATURE-----

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-----
iQEcBAABAgAGBQJZFciYAAoJEJykq7OBq3PINCgH/1IXhfLR6AtPKAa0b2oABWEW
 lD90HiHIxeqYIDiVnppD6CEnIZ6VBmImSyRr6V9Fk7OTkCucVRLOXFZF63d7ETDo
 PBF8+FJ8YgdClJ80f3HkmPu6vzvnRzcs5mUBrrKhZPAy2adxNmIpfir/78p+Aomd
 HxCYl3jF6aVUtFEtzTwAmDjXU2NUNPQABAAKiGT5jwSUcksxogg7LSIM/ZlFzNhc
 ZMI9h6doRP0v3kLyh429qVEgXpCh7VaD9Swv6H3/sSHJdCBP5MILrTADrK+45tmL
 nIxHruOyt63Jgd8acGDdvYz1oHjPXb2Cn/87SiONsqwoyFJmkqbVXvOg4gqPuJ8=
 =yXgr
 -----END PGP SIGNATURE-----

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