Commit Graph

1285 Commits

Author SHA1 Message Date
Markus Armbruster
e688df6bc4 Include qapi/error.h exactly where needed
This cleanup makes the number of objects depending on qapi/error.h
drop from 1910 (out of 4743) to 1612 in my "build everything" tree.

While there, separate #include from file comment with a blank line,
and drop a useless comment on why qemu/osdep.h is included first.

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: <20180201111846.21846-5-armbru@redhat.com>
[Semantic conflict with commit 34e304e975 resolved, OSX breakage fixed]
2018-02-09 13:50:17 +01:00
Kevin Wolf
1a63a90750 block: Keep nodes drained between reopen_queue/multiple
The bdrv_reopen*() implementation doesn't like it if the graph is
changed between queuing nodes for reopen and actually reopening them
(one of the reasons is that queuing can be recursive).

So instead of draining the device only in bdrv_reopen_multiple(),
require that callers already drained all affected nodes, and assert this
in bdrv_reopen_queue().

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
2017-12-22 15:05:32 +01:00
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
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
cc954f01e3 block: Open backing image in force share mode for size probe
Management tools create overlays of running guests with qemu-img:

  $ qemu-img create -b /image/in/use.qcow2 -f qcow2 /overlay/image.qcow2

but this doesn't work anymore due to image locking:

    qemu-img: /overlay/image.qcow2: Failed to get shared "write" lock
    Is another process using the image?
    Could not open backing image to determine size.
Use the force share option to allow this use case again.

Cc: qemu-stable@nongnu.org
Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-12-22 15:03:41 +01:00
Kevin Wolf
5fbfabd313 block: Formats don't need CONSISTENT_READ with NO_IO
Commit 1f4ad7d fixed 'qemu-img info' for raw images that are currently
in use as a mirror target. It is not enough for image formats, though,
as these still unconditionally request BLK_PERM_CONSISTENT_READ.

As this permission is geared towards whether the guest-visible data is
consistent, and has no impact on whether the metadata is sane, and
'qemu-img info' does not read guest-visible data (except for the raw
format), it makes sense to not require BLK_PERM_CONSISTENT_READ if there
is not going to be any guest I/O performed, regardless of image format.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-12-22 15:03:41 +01:00
Paolo Bonzini
bd6458e410 block: avoid recursive AioContext acquire in bdrv_inactivate_all()
BDRV_POLL_WHILE() does not support recursive AioContext locking.  It
only releases the AioContext lock once regardless of how many times the
caller has acquired it.  This results in a hang since the IOThread does
not make progress while the AioContext is still locked.

The following steps trigger the hang:

  $ qemu-system-x86_64 -M accel=kvm -m 1G -cpu host \
                       -object iothread,id=iothread0 \
                       -device virtio-scsi-pci,iothread=iothread0 \
                       -drive if=none,id=drive0,file=test.img,format=raw \
                       -device scsi-hd,drive=drive0 \
                       -drive if=none,id=drive1,file=test.img,format=raw \
                       -device scsi-hd,drive=drive1
  $ qemu-system-x86_64 ...same options... \
                       -incoming tcp::1234
  (qemu) migrate tcp:127.0.0.1:1234
  ...hang...

Tested-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20171207201320.19284-2-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-12-19 10:25:09 +00:00
Alberto Garcia
50a3efb0f0 block: Close a BlockDriverState completely even when bs->drv is NULL
bdrv_close() skips much of its logic when bs->drv is NULL. This is
fine when we're closing a BlockDriverState that has just been created
(because e.g the initialization process failed), but it's not enough
in other cases.

For example, when a valid qcow2 image is found to be corrupted then
QEMU marks it as such in the file header and then sets bs->drv to
NULL in order to make the BlockDriverState unusable. When that BDS is
later closed then many of its data structures are not freed (leaking
their memory) and none of its children are detached. This results in
bdrv_close_all() failing to close all BDSs and making this assertion
fail when QEMU is being shut down:

   bdrv_close_all: Assertion `QTAILQ_EMPTY(&all_bdrv_states)' failed.

This patch makes bdrv_close() do the full uninitialization process
in all cases. This fixes the problem with corrupted images and still
works fine with freshly created BDSs.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-id: 20171106145345.12038-1-berto@igalia.com
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-11-21 14:54:02 +01:00
Kevin Wolf
dacaa16238 block: Don't use BLK_PERM_CONSISTENT_READ for format probing
For format probing, we don't really care whether all of the image
content is consistent. The only thing we're looking at is the image
header, and specifically the magic numbers that are expected to never
change, no matter how inconsistent the guest visible disk content is.

Therefore, don't request BLK_PERM_CONSISTENT_READ. This allows to use
format probing, e.g. in the context of 'qemu-img info', even while the
guest visible data in the image is inconsistent during a running block
job.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@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
Max Reitz
d470ad42ac block: Guard against NULL bs->drv
We currently do not guard everywhere against a NULL bs->drv where we
should be doing so.  Most of the places fixed here just do not care
about that case at all.

Some care implicitly, e.g. through a prior function call to
bdrv_getlength() which would always fail for an ejected BDS.  Add an
assert there to make it more obvious.

Other places seem to care, but do so insufficiently: Freeing clusters in
a qcow2 image is an error-free operation, but it may leave the image in
an unusable state anyway.  Giving qcow2_free_clusters() an error code is
not really viable, it is much easier to note that bs->drv may be NULL
even after a successful driver call.  This concerns bdrv_co_flush(), and
the way the check is added to bdrv_co_pdiscard() (in every iteration
instead of only once).

Finally, some places employ at least an assert(bs->drv); somewhere, that
may be reasonable (such as in the reopen code), but in
bdrv_has_zero_init(), it is definitely not.  Returning 0 there in case
of an ejected BDS saves us much headache instead.

Reported-by: R. Nageswara Sastry <nasastry@in.ibm.com>
Buglink: https://bugs.launchpad.net/qemu/+bug/1728660
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20171110203111.7666-4-mreitz@redhat.com
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-11-17 18:21:31 +01:00
Max Reitz
54fd1b0d26 block: qobject_is_equal() in bdrv_reopen_prepare()
Currently, bdrv_reopen_prepare() assumes that all BDS options are
strings. However, this is not the case if the BDS has been created
through the json: pseudo-protocol or blockdev-add.

Note that the user-invokable reopen command is an HMP command, so you
can only specify strings there. Therefore, specifying a non-string
option with the "same" value as it was when originally created will now
return an error because the values are supposedly similar (and there is
no way for the user to circumvent this but to just not specify the
option again -- however, this is still strictly better than just
crashing).

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20171114180128.17076-5-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-11-17 18:21:30 +01:00
Kevin Wolf
dafe096057 block: Fix permissions in image activation
Inactive images generally request less permissions for their image files
than they would if they were active (in particular, write permissions).
Activating the image involves extending the permissions, therefore.

drv->bdrv_invalidate_cache() can already require write access to the
image file, so we have to update the permissions earlier than that.
The current code does it only later, so we have to move up this part.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2017-11-17 18:06:12 +01:00
Kevin Wolf
398e6ad014 block: Deprecate bdrv_set_read_only() and users
bdrv_set_read_only() is used by some block drivers to override the
read-only option given by the user. This is not how read-only images
generally work in QEMU: Instead of second guessing what the user really
meant (which currently includes making an image read-only even if the
user didn't only use the default, but explicitly said read-only=off), we
should error out if we can't provide what the user requested.

This adds deprecation warnings to all callers of bdrv_set_read_only() so
that the behaviour can be corrected after the usual deprecation period.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-11-17 13:35:59 +01:00
Kevin Wolf
6473069416 block: Fix error path in bdrv_backing_update_filename()
error_setg_errno() takes a positive errno code. Spotted by Coverity
(CID 1381628).

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-11-17 13:35:59 +01:00
Peter Krempa
6bff597bf6 block: don't add 'driver' to options when referring to backing via node name
When referring to a backing file of an image via node name
bdrv_open_backing_file would add the 'driver' option to the option list
filling it with the backing format driver. This breaks construction of
the backing chain via -blockdev, as bdrv_open_inherit reports an error
if both 'reference' and 'options' are provided.

$ qemu-img create -f raw /tmp/backing.raw 64M
$ qemu-img create -f qcow2 -F raw -b /tmp/backing.raw /tmp/test.qcow2
$ qemu-system-x86_64 \
  -blockdev driver=file,filename=/tmp/backing.raw,node-name=backing \
  -blockdev driver=qcow2,file.driver=file,file.filename=/tmp/test.qcow2,node-name=root,backing=backing
qemu-system-x86_64: -blockdev driver=qcow2,file.driver=file,file.filename=/tmp/test.qcow2,node-name=root,backing=backing: Could not open backing file: Cannot reference an existing block device with additional options or a new filename

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-10-26 14:45:57 +02:00
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
61f09cea01 commit: Support multiple roots above top node
This changes the commit block job to support operation in a graph where
there is more than a single active layer that references the top node.

This involves inserting the commit filter node not only on the path
between the given active node and the top node, but between the top node
and all of its parents.

On completion, bdrv_drop_intermediate() must consider all parents for
updating the backing file link. These parents may be backing files
themselves and as such read-only; reopen them temporarily if necessary.
Previously this was achieved by the bdrv_reopen() calls in the commit
block job that made overlay_bs read-write for the whole duration of the
block job, even though write access is only needed on completion.

Now that we consider all parents, overlay_bs is meaningless. It is left
in place in this commit, but we'll remove it soon.

Signed-off-by: Kevin Wolf <kwolf@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
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
a8b42a1c09 block: Make bdrv_img_create() size selection easier to read
All callers of bdrv_img_create() pass in a size, or -1 to read the
size from the backing file.  We then set that size as the QemuOpt
default, which means we will reuse that default rather than the
final parameter to qemu_opt_get_size() several lines later.  But
it is rather confusing to read subsequent checks of 'size == -1'
when it looks (without seeing the full context) like size defaults
to 0; it also doesn't help that a size of 0 is valid (for some
formats).

Rework the logic to make things more legible.

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
1857c97b76 block: reopen: Queue children after their parents
We will calculate the required new permissions in the prepare stage of a
reopen. Required permissions of children can be influenced by the
changes made to their parents, but parents are independent from their
children. This means that permissions need to be calculated top-down. In
order to achieve this, queue parents before their children rather than
queuing the children first.

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
3121fb45b0 block: Add reopen queue to bdrv_check_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
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
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
Marc-André Lureau
f7abe0ecd4 qapi: Change data type of the FOO_lookup generated for enum FOO
Currently, a FOO_lookup is an array of strings terminated by a NULL
sentinel.

A future patch will generate enums with "holes".  NULL-termination
will cease to work then.

To prepare for that, store the length in the FOO_lookup by wrapping it
in a struct and adding a member for the length.

The sentinel will be dropped next.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20170822132255.23945-13-marcandre.lureau@redhat.com>
[Basically redone]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1503564371-26090-16-git-send-email-armbru@redhat.com>
[Rebased]
2017-09-04 13:09:13 +02:00
Markus Armbruster
5b5f825d44 qapi: Generate FOO_str() macro for QAPI enum FOO
The next commit will put it to use.  May look pointless now, but we're
going to change the FOO_lookup's type, and then it'll help.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1503564371-26090-13-git-send-email-armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
2017-09-04 13:09:13 +02:00
Markus Armbruster
06c60b6c46 qapi: Drop superfluous qapi_enum_parse() parameter max
The lookup tables have a sentinel, no need to make callers pass their
size.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1503564371-26090-3-git-send-email-armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[Rebased, commit message corrected]
2017-09-04 13:09:13 +02:00
Stefan Hajnoczi
7d5b526110 block: Update open_flags after ->inactivate() callback
In the ->inactivate() callbacks, permissions are updated, which
typically involves a recursive check of the whole graph. Setting
BDRV_O_INACTIVE right before doing that creates a state that
bdrv_is_writable() returns false, which causes permission update
failure.

Reorder them so the flag is updated after calling the function. Note
that this doesn't break the assert in bdrv_child_cb_inactivate() because
for any specific BDS, we still update its flags first before calling
->inactivate() on it one level deeper in the recursion.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
Message-Id: <20170823134242.12080-5-famz@redhat.com>
Tested-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2017-08-23 10:21:55 -05:00
Kevin Wolf
fd4520212b block: Set BDRV_O_ALLOW_RDWR during rw reopen
Reopening an image should be consistent with opening it, so we should
set BDRV_O_ALLOW_RDWR for any image that is reopened read-write like in
bdrv_open_inherit().

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
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
Kevin Wolf
8aecf1d1bd block: Fix order in bdrv_replace_child()
Commit 8ee03995 refactored the code incorrectly and broke the release of
permissions on the old BDS. Instead of changing the permissions to the
new required values after removing the old BDS from the list of
children, it only re-obtains the permissions it already had.

Change the order of operations so that the old BDS is removed again
before calculating the new required permissions.

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
Manos Pitsidianakis
180ca19ae0 block: fix leaks in bdrv_open_driver()
bdrv_open_driver() is called in two places, bdrv_new_open_driver() and
bdrv_open_common(). In the latter, failure cleanup in is in its caller,
bdrv_open_inherit(), which unrefs the bs->file of the failed driver open
if it exists.

Let's move the bs->file cleanup to bdrv_open_driver() to take care of
all callers and do not set bs->drv to NULL unless the driver's open
function failed. When bs is destroyed by removing its last reference, it
calls bdrv_close() which checks bs->drv to perform the needed cleanups
and also call the driver's close function. Since it cleans up options
and opaque we must take care not leave dangling pointers.

The error paths in bdrv_open_driver() are now two:
If open fails, drv->bdrv_close() should not be called. Unref the child
if it exists, free what we allocated and set bs->drv to NULL. Return the
error and let callers free their stuff.

If open succeeds but we fail after, return the error and let callers
unref and delete their bs, while cleaning up their allocations.

Signed-off-by: Manos Pitsidianakis <el13635@mail.ntua.gr>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-08-01 18:09:33 +02:00
Manos Pitsidianakis
998cbd6a44 block: fix dangling bs->explicit_options in block.c
In some error paths it is possible to QDECREF a freed dangling
explicit_options, resulting in a heap overflow crash.  For example
bdrv_open_inherit()'s fail unrefs it, then calls bdrv_unref which calls
bdrv_close which also unrefs it.

Signed-off-by: Manos Pitsidianakis <el13635@mail.ntua.gr>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-08-01 18:09:33 +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
John Snow
6e6e55f5c2 qemu-img: Check for backing image if specified during create
Or, rather, force the open of a backing image if one was specified
for creation. Using a similar -unsafe option as rebase, allow qemu-img
to ignore the backing file validation if possible.

It may not always be possible, as in the existing case when a filesize
for the new image was not specified.

This is accomplished by shifting around the conditionals in
bdrv_img_create, such that a backing file is always opened unless we
provide BDRV_O_NO_BACKING. qemu-img is adjusted to pass this new flag
when -u is provided to create.

Sorry for the heinous looking diffstat, but it's mostly whitespace.

Inspired by: https://bugzilla.redhat.com/show_bug.cgi?id=1213786

Signed-off-by: John Snow <jsnow@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-07-18 15:27:37 +02:00
Peter Maydell
a309b290aa Error reporting patches for 2017-07-13
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Merge remote-tracking branch 'remotes/armbru/tags/pull-error-2017-07-13' into staging

Error reporting patches for 2017-07-13

# gpg: Signature made Thu 13 Jul 2017 12:55:45 BST
# gpg:                using RSA key 0x3870B400EB918653
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>"
# gpg:                 aka "Markus Armbruster <armbru@pond.sub.org>"
# Primary key fingerprint: 354B C8B3 D7EB 2A6B 6867  4E5F 3870 B400 EB91 8653

* remotes/armbru/tags/pull-error-2017-07-13:
  Convert error_report*_err() to warn_report*_err()
  error: Implement the warn and free Error functions
  char-socket: Report TCP socket waiting as information
  Convert error_report() to warn_report()
  error: Functions to report warnings and informational messages
  util/qemu-error: Rename error_print_loc() to be more generic
  websock: Don't try to set *errp directly
  block: Don't try to set *errp directly
  xilinx: Fix latent error handling bug

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2017-07-14 09:36:40 +01:00
Eduardo Habkost
57ef3f1278 block: Don't try to set *errp directly
Assigning directly to *errp is not valid, as errp may be NULL,
&error_fatal, or &error_abort.  Use error_propagate() instead.

With this, there's no need to check if errp is NULL anymore, as
error_propagate() and error_prepend() are able to handle that.

Cc: Kevin Wolf <kwolf@redhat.com>
Cc: Max Reitz <mreitz@redhat.com>
Cc: qemu-block@nongnu.org
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <20170608133906.12737-3-ehabkost@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2017-07-13 13:45:53 +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
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
cca43ae1e1 block: bdrv_close: release bitmaps after drv->bdrv_close
Release bitmaps after 'if (bs->drv) { ... }' block. This will allow
format driver to save persistent bitmaps, which will appear in following
commits.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20170628120530.31251-17-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
50bf65bab6 block: refactor bdrv_reopen_commit
Add bs local variable to simplify code.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 20170628120530.31251-13-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:44:58 +02:00
sochin.jiang
5ce6bfe255 mirror: Fix inconsistent backing AioContext for after mirroring
mirror_complete opens the backing chain, which should have the same
AioContext as the top when using iothreads. Make the code guarantee
this, which fixes a failed assertion in bdrv_attach_child.

Signed-off-by: sochin.jiang <sochin.jiang@huawei.com>
Message-id: 1498475064-39816-1-git-send-email-sochin.jiang@huawei.com
[mreitz: Reworded commit message]
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
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
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
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
Max Reitz
0d54a6fed3 block: Fix backing paths for filenames with colons
path_combine() naturally tries to preserve a protocol prefix. However,
it recognizes such a prefix by scanning for the first colon; which is
different from what path_has_protocol() does: There only is a protocol
prefix if there is a colon before the first slash.

A protocol prefix that is not recognized by path_has_protocol() is none,
and should thus not be taken as one.

Case in point, before this patch:
$ ./qemu-img create -f qcow2 -b backing.qcow2 ./top:image.qcow2
qemu-img: ./top:image.qcow2: Could not open './top:backing.qcow2':
    No such file or directory

Afterwards:
$ ./qemu-img create -f qcow2 -b backing.qcow2 ./top:image.qcow2
qemu-img: ./top:image.qcow2: Could not open './backing.qcow2':
    No such file or directory

Reported-by: yangyang <yangyang@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20170522195217.12991-2-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-05-29 15:39:54 +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
38701b6aef block: Inactivate parents before children
The proper order for inactivating block nodes is that first the parents
get inactivated and then the children. If we do things in this order, we
can assert that we didn't accidentally leave a parent activated when one
of its child nodes is inactive.

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
ffd1a5a25c block: Respect "force-share" in perm propagating
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
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
Eric Blake
ff6ed7141d block: Simplify bdrv_append_temp_snapshot() logic
Noticed while checking Coccinelle results. Naming a label 'out:'
when it is only used on error paths is weird.  Also, we had some
dead stores to 'ret'.  Meanwhile we know that snapshot_options
is NULL on success and that QDECREF(NULL) is safe.  So merge the
two exit paths into one by careful control over bs_snapshot.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20170427215821.19397-8-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2017-05-09 09:14:39 +02:00
Eric Blake
46f5ac205a qobject: Use simpler QDict/QList scalar insertion macros
We now have macros in place to make it less verbose to add a scalar
to QDict and QList, so use them.

Patch created mechanically via:
  spatch --sp-file scripts/coccinelle/qobject.cocci \
    --macro-file scripts/cocci-macro-file.h --dir . --in-place
then touched up manually to fix a couple of '?:' back to original
spacing, as well as avoiding a long line in monitor.c.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20170427215821.19397-7-eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2017-05-09 09:13:51 +02:00
Eric Blake
de6e7951fe qobject: Drop useless QObject casts
We have macros in place to make it less verbose to add a subtype
of QObject to both QDict and QList. While we have made cleanups
like this in the past (see commit fcfcd8ffc, for example), having
it be automated by Coccinelle makes it easier to maintain.

Patch created mechanically via:
  spatch --sp-file scripts/coccinelle/qobject.cocci \
    --macro-file scripts/cocci-macro-file.h --dir . --in-place
then I verified that no manual touchups were required.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20170427215821.19397-5-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2017-05-08 20:32:14 +02:00
Denis V. Lunev
504c205a0d block: assert no image modification under BDRV_O_INACTIVE
As long as BDRV_O_INACTIVE is set, the image file is only opened so we
have a file descriptor for it. We're definitely not supposed to modify
the image, it's still owned by the migration source.

This commit is an addition to 09e0c771 but the assert() is added to
bdrv_truncate().

Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Kevin Wolf <kwolf@redhat.com>
CC: Max Reitz <mreitz@redhat.com>
Message-id: 1491405505-31620-3-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
f59adb3256 block: Add .bdrv_truncate() error messages
Add missing error messages for the block driver implementations of
.bdrv_truncate(); drop the generic one from block.c's bdrv_truncate().

Since one of these changes touches a mis-indented block in
block/file-posix.c, this patch fixes that coding style issue along the
way.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20170328205129.15138-5-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
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
Max Reitz
4a0082401a block: An empty filename counts as no filename
Reproducer:
    $ ./qemu-img info ''
    qemu-img: ./block.c:1008: bdrv_open_driver: Assertion
        `!drv->bdrv_needs_filename || bs->filename[0]' failed.
    [1]    26105 abort (core dumped)  ./qemu-img info ''

This patch fixes this to be:
    $ ./qemu-img info ''
    qemu-img: Could not open '': The 'file' block driver requires a file
    name

Cc: qemu-stable <qemu-stable@nongnu.org>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-04-27 15:39:49 +02:00
Max Reitz
362b3786eb Revert "block/io: Comment out permission assertions"
This reverts commit e3e0003a8f.

This commit was necessary for the 2.9 release because we were unable to
fix the underlying issue(s) in time. However, we will be for 2.10.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-04-27 15:39:49 +02:00
Jeff Cody
3d8ce171cb block: use bdrv_can_set_read_only() during reopen
Signed-off-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 00aed7ffdd7be4b9ed9ce1007d50028a72b34ebe.1491597120.git.jcody@redhat.com
2017-04-24 15:09:33 -04:00
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
93ed524e3d block: code movement
Move bdrv_is_read_only() up with its friends.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Jeff Cody <jcody@redhat.com>
Message-id: 73b2399459760c32506f9407efb9dddb3a2789de.1491597120.git.jcody@redhat.com
2017-04-24 15:09:33 -04:00
Jeff Cody
d6fcdf06d9 block: honor BDRV_O_ALLOW_RDWR when clearing bs->read_only
The BDRV_O_ALLOW_RDWR flag allows / prohibits the changing of
the BDS 'read_only' state, but there are a few places where it
is ignored.  In the bdrv_set_read_only() helper, make sure to
honor the flag.

Signed-off-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: be2e5fb2d285cbece2b6d06bed54a6f56520d251.1491597120.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
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
Max Reitz
e3e0003a8f block/io: Comment out permission assertions
In case of block migration, there may be writes to BlockBackends that do
not have the write permission taken. Before this issue is fixed (which
is not going to happen in 2.9), we therefore cannot assert that this is
the case.

Suggested-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Tested-by: Kevin Wolf <kwolf@redhat.com>
Message-id: 20170411145050.31290-1-mreitz@redhat.com
Tested-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2017-04-11 16:09:31 +01:00
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
aabf591007 block: Quiesce old aio context during bdrv_set_aio_context
The fact that the bs->aio_context is changing can confuse the dataplane
iothread, because of the now fine granularity aio context lock.
bdrv_drain should rather be a bdrv_drained_begin/end pair, but since
bs->aio_context is changing, we can just use aio_disable_external and
bdrv_parent_drained_begin.

Reported-by: Ed Swierk <eswierk@skyportsystems.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
2017-04-11 20:07:15 +08:00
Fam Zheng
bb2614e991 block: Assert attached child node has right aio context
Suggested-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-04-07 14:44:06 +02:00
Markus Armbruster
129c7d1c53 block: Document -drive problematic code and bugs
-blockdev and blockdev_add convert their arguments via QObject to
BlockdevOptions for qmp_blockdev_add(), which converts them back to
QObject, then to a flattened QDict.  The QDict's members are typed
according to the QAPI schema.

-drive converts its argument via QemuOpts to a (flat) QDict.  This
QDict's members are all QString.

Thus, the QType of a flat QDict member depends on whether it comes
from -drive or -blockdev/blockdev_add, except when the QAPI type maps
to QString, which is the case for 'str' and enumeration types.

The block layer core extracts generic configuration from the flat
QDict, and the block driver extracts driver-specific configuration.

Both commonly do so by converting (parts of) the flat QDict to
QemuOpts, which turns all values into strings.  Not exactly elegant,
but correct.

However, A few places access the flat QDict directly:

* Most of them access members that are always QString.  Correct.

* bdrv_open_inherit() accesses a boolean, carefully.  Correct.

* nfs_config() uses a QObject input visitor.  Correct only because the
  visited type contains nothing but QStrings.

* nbd_config() and ssh_config() use a QObject input visitor, and the
  visited types contain non-QStrings: InetSocketAddress members
  @numeric, @to, @ipv4, @ipv6.  -drive works as long as you don't try
  to use them (they're all optional).  @to is ignored anyway.

  Reproducer:
  -drive driver=ssh,server.host=h,server.port=22,server.ipv4,path=p
  -drive driver=nbd,server.type=inet,server.data.host=h,server.data.port=22,server.data.ipv4
  both fail with "Invalid parameter type for 'data.ipv4', expected: boolean"

Add suitable comments to all these places.  Mark the buggy ones FIXME.

"Fortunately", -drive's driver-specific options are entirely
undocumented.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-id: 1490895797-29094-5-git-send-email-armbru@redhat.com
[mreitz: Fixed two typos]
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-04-03 17:11:39 +02:00
Paolo Bonzini
c2b6428d38 block: quiesce AioContext when detaching from it
While it is true that bdrv_set_aio_context only works on a single
BlockDriverState subtree (see commit message for 53ec73e, "block: Use
bdrv_drain to replace uncessary bdrv_drain_all", 2015-07-07), it works
at the AioContext level rather than the BlockDriverState level.

Therefore, it is also necessary to trigger pending bottom halves too,
even if no requests are pending.

For NBD this ensures that the aio_co_schedule of a previous call to
nbd_attach_aio_context is completed before detaching from the old
AioContext; it fixes qemu-iotest 094.  Another similar bug happens
when the VM is stopped and the virtio-blk dataplane irqfd is torn down.
In this case it's possible that guest I/O gets stuck if notify_guest_bh
was scheduled but doesn't run.

Calling aio_poll from another AioContext is safe if non-blocking; races
such as the one mentioned in the commit message for c9d1a56 ("block:
only call aio_poll on the current thread's AioContext", 2016-10-28)
are a concern for blocking calls.

I considered other options, including:

- moving the bs->wakeup mechanism to AioContext, and letting the caller
check.  This might work for virtio which has a clear place to wakeup
(notify_place_bh) and check the condition (virtio_blk_data_plane_stop).
For aio_co_schedule I couldn't find a clear place to check the condition.

- adding a dummy oneshot bottom half and waiting for it to trigger.
This has the complication that bottom half list is LIFO for historical
reasons.  There were performance issues caused by bottom half ordering
in the past, so I decided against it for 2.9.

Fixes: 9972354856
Reported-by: Max Reitz <mreitz@redhat.com>
Reported-by: Halil Pasic <pasic@linux.vnet.ibm.com>
Tested-by: Halil Pasic <pasic@linux.vnet.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 20170314111157.14464-2-pbonzini@redhat.com
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-03-17 12:58:42 +01:00
Fam Zheng
8cd1a3e470 block: Propagate error in bdrv_open_backing_file
Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-03-17 12:54:06 +01:00
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
9e7e940c3d block: Refresh filename after changing backing file
In bdrv_open_inherit(), the filename is refreshed after opening the
backing file, but we neglected to do the same when the backing file
changes later.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2017-03-13 12:49:33 +01:00
Kevin Wolf
466787fbca block: Remove check_new_perm from bdrv_replace_child()
All callers pass false now, so the parameter can go away again.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2017-03-13 12:49:33 +01:00
Peter Maydell
b64842dee4 Block layer fixes for 2.9.0-rc0
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Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into staging

Block layer fixes for 2.9.0-rc0

# gpg: Signature made Tue 07 Mar 2017 14:59:18 GMT
# 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

* remotes/kevin/tags/for-upstream: (27 commits)
  commit: Don't use error_abort in commit_start
  block: Don't use error_abort in blk_new_open
  sheepdog: Support blockdev-add
  qapi-schema: Rename SocketAddressFlat's variant tcp to inet
  qapi-schema: Rename GlusterServer to SocketAddressFlat
  gluster: Plug memory leaks in qemu_gluster_parse_json()
  gluster: Don't duplicate qapi-util.c's qapi_enum_parse()
  gluster: Drop assumptions on SocketTransport names
  sheepdog: Implement bdrv_parse_filename()
  sheepdog: Use SocketAddress and socket_connect()
  sheepdog: Report errors in pseudo-filename more usefully
  sheepdog: Don't truncate long VDI name in _open(), _create()
  sheepdog: Fix snapshot ID parsing in _open(), _create, _goto()
  sheepdog: Mark sd_snapshot_delete() lossage FIXME
  sheepdog: Fix error handling sd_create()
  sheepdog: Fix error handling in sd_snapshot_delete()
  sheepdog: Defuse time bomb in sd_open() error handling
  block: Fix error handling in bdrv_replace_in_backing_chain()
  block: Handle permission errors in change_parent_backing_link()
  block: Ignore multiple children in bdrv_check_update_perm()
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2017-03-08 09:47:52 +00:00
Markus Armbruster
5577fff738 block: More detailed syntax error reporting for JSON filenames
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <1488317230-26248-14-git-send-email-armbru@redhat.com>
2017-03-07 16:07:47 +01:00
Markus Armbruster
57348c2f18 qobject: Propagate parse errors through qobject_from_json()
The next few commits will put the errors to use where appropriate.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1488317230-26248-13-git-send-email-armbru@redhat.com>
2017-03-07 16:07:47 +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
234ac1a902 block: Handle permission errors in change_parent_backing_link()
Instead of just trying to change parents by parent over to reference @to
instead of @from, and abort()ing whenever the permissions don't allow
this, do proper permission checking beforehand and pass any error to the
callers.

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
8ee039951d block: Factor out bdrv_replace_child_noperm()
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
d0ac038025 block: Factor out should_update_child()
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
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
c8f6d58edb block: Assertions for resize permission
This adds an assertion that ensures that the necessary resize permission
has been granted before bdrv_truncate() is called.

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
3e44c8e08a block: Allow backing file links in change_parent_backing_link()
Now that the backing file child role implements .attach/.detach
callbacks, nothing prevents us from modifying the graph even if that
involves changing backing file links.

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
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
dd65a52e4a block: Fix pending requests check in bdrv_append()
bdrv_append() cares about isolation of the node that it modifies, but
not about activity in some subtree below it. Instead of using the
recursive bdrv_requests_pending(), directly check bs->in_flight, which
considers only the node in question.

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
d083319fe0 block: Include details on permission errors in message
Instead of just telling that there was some conflict, we can be specific
and tell which permissions were in conflict and which way the conflict
is.

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
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
d7086422b1 block: Add error parameter to blk_insert_bs()
Now that blk_insert_bs() requests the BlockBackend permissions for the
node it attaches to, it can fail. Instead of aborting, pass the errors
to the callers.

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
6d0eb64d5c block: Add permissions to blk_new()
We want every user to be specific about the permissions it needs, so
we'll pass the initial permissions as parameters to blk_new(). A user
only needs to call blk_set_perm() if it wants to change the permissions
after the fact.

The permissions are stored in the BlockBackend and applied whenever a
BlockDriverState should be attached in blk_insert_bs().

This does not include actually choosing the right set of permissions
everywhere yet. Instead, the usual FIXME comment is added to each place
and will be addressed in individual patches.

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
f68c598be6 block: Request real permissions in bdrv_attach_child()
Now that all block drivers with children tell us what permissions they
need from each of their children, bdrv_attach_child() can use this
information and make the right requirements while trying to attach new
children.

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
78e421c9fb block: Require .bdrv_child_perm() with child nodes
All block drivers that can have child nodes implement .bdrv_child_perm()
now. Make this officially a requirement by asserting that only drivers
without children can omit .bdrv_child_perm().

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
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
Peter Maydell
6b4e463ff3 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 24 Feb 2017 18:08:26 GMT
# 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

* remotes/kevin/tags/for-upstream:
  tests: Use opened block node for block job tests
  vvfat: Use opened node as backing file
  block: Add bdrv_new_open_driver()
  block: Factor out bdrv_open_driver()
  block: Use BlockBackend for image probing
  block: Factor out bdrv_open_child_bs()
  block: Attach bs->file only during .bdrv_open()
  block: Pass BdrvChild to bdrv_truncate()
  mirror: Resize active commit base in mirror_run()
  qcow2: Use BB for resizing in qcow2_amend_options()
  blockdev: Use BlockBackend to resize in qmp_block_resize()
  iotests: Fix another race in 030
  qemu-img: Improve documentation for PREALLOC_MODE_FALLOC
  qemu-img: Truncate before full preallocation
  qemu-img: Add tests for raw image preallocation
  qemu-img: Do not truncate before preallocation
  qemu-iotests: redirect nbd server stdout to /dev/null
  qemu-iotests: add ability to exclude certain protocols from tests
  qemu-iotests: Test 137 only supports 'file' protocol

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2017-02-26 12:26:37 +00:00
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
01a5650179 block: Factor out bdrv_open_driver()
This is a function that doesn't do any option parsing, but just does
some basic BlockDriverState setup and calls the .bdrv_open() function of
the block driver.

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
5696c6e350 block: Use BlockBackend for image probing
This fixes the use of a parent-less BdrvChild in bdrv_open_inherit() by
converting it into a BlockBackend. Which is exactly what it should be,
image probing is an external, standalone user of a node. The requests
can't be considered to originate from the format driver node because
that one isn't even opened yet.

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
2d6b86af14 block: Factor out bdrv_open_child_bs()
This is the part of bdrv_open_child() that opens a BDS with option
inheritance, but doesn't attach it as a child to the parent yet.

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
4e4bf5c42c block: Attach bs->file only during .bdrv_open()
The way that attaching bs->file worked was a bit unusual in that it was
the only child that would be attached to a node which is not opened yet.
Because of this, the block layer couldn't know yet which permissions the
driver would eventually need.

This patch moves the point where bs->file is attached to the beginning
of the individual .bdrv_open() implementations, so drivers already know
what they are going to do with the child. This is also more consistent
with how driver-specific children work.

For a moment, bdrv_open() gets its own BdrvChild to perform image
probing, but instead of directly assigning this BdrvChild to the BDS, it
becomes a temporary one and the node name is passed as an option to the
drivers, so that they can simply use bdrv_open_child() to create another
reference for their own use.

This duplicated child for (the not opened yet) bs is not the final
state, a follow-up patch will change the image probing code to use a
BlockBackend, which is completely independent of bs.

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
Markus Armbruster
ca6b6e1e68 Don't check qobject_type() before qobject_to_qdict()
qobject_to_qdict(obj) returns NULL when obj isn't a QDict.  Check
that instead of qobject_type(obj) == QTYPE_QDICT.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1487363905-9480-8-git-send-email-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2017-02-22 19:52:01 +01:00
Vladimir Sementsov-Ogievskiy
16e977d506 block: bdrv_invalidate_cache: invalidate children first
Current implementation invalidates firstly parent bds and then its
children. This leads to the following bug:

after incoming migration, in bdrv_invalidate_cache_all:
1. invalidate parent bds - reopen it with BDRV_O_INACTIVE cleared
2. child is not yet invalidated
3. parent check that its BDRV_O_INACTIVE is cleared
4. parent writes to child
5. assert in bdrv_co_pwritev, as BDRV_O_INACTIVE is set for child

This patch fixes it by just changing invalidate sequence: invalidate
children first.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20170131112308.54189-1-vsementsov@virtuozzo.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-02-12 00:47:42 +01:00
Jeff Cody
418661e032 block: check full backing filename when searching protocol filenames
In bdrv_find_backing_image(), if we are searching an image for a backing
file that contains a protocol, we currently only compare unmodified
paths.

However, some management software will change the backing filename to be
a relative filename in a path.  QEMU is able to handle this fine,
because internally it will use path_combine to put together the full
protocol URI.

However, this can lead to an inability to match an image during a QAPI
command that needs to use bdrv_find_backing_image() to find the image,
when it is searched by the full URI.

When searching for a protocol filename, if the straight comparison
fails, this patch will also compare against the full backing filename to
see if that is a match.

Signed-off-by: Jeff Cody <jcody@redhat.com>
Message-id: c2d025adca8a2b665189e6f4cf080f44126d0b6b.1485392617.git.jcody@redhat.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-02-12 00:47:42 +01:00
Daniel P. Berrange
0ab8ed18a6 trace: switch to modular code generation for sub-directories
Introduce rules in the top level Makefile that are able to generate
trace.[ch] files in every subdirectory which has a trace-events file.

The top level directory is handled specially, so instead of creating
trace.h, it creates trace-root.h. This allows sub-directories to
include the top level trace-root.h file, without ambiguity wrt to
the trace.g file in the current sub-dir.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 20170125161417.31949-7-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-01-31 17:11:18 +00:00
Paolo Bonzini
7ad2757fef block: remove dead check
options must be non-NULL here, because a NULL value is replaced with
qdict_new earlier in the function.  Reported by Coverity.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2017-01-24 23:26:53 +03:00
Max Reitz
eb0df69f50 block: Emit modules in bdrv_iterate_format()
Some block drivers may not be loaded yet, but qemu supports them
nonetheless. bdrv_iterate_format() should report them, too.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20161012204907.25941-3-mreitz@redhat.com
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-11-11 15:56:22 +01:00
Max Reitz
ceff5bd79c block: Fix bdrv_iterate_format() sorting
bdrv_iterate_format() did not actually sort the formats by name but by
"pointer interpreted as string". That is probably not what we intended
to do, so fix it (by changing qsort_strcmp() so it matches the example
from qsort()'s manual page).

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20161012204907.25941-2-mreitz@redhat.com
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-11-11 15:56:22 +01:00
Alberto Garcia
61b49e48b3 block: Support streaming to an intermediate layer
This makes sure that the image we are streaming into is open in
read-write mode during the operation.

Operation blockers are also set in all intermediate nodes, since they
will be removed from the chain afterwards.

Finally, this also unblocks the stream operation in backing files.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-10-31 16:52:38 +01:00
Alberto Garcia
40840e419b block: Pause all jobs during bdrv_reopen_multiple()
When a BlockDriverState is about to be reopened it can trigger certain
operations that need to write to disk. During this process a different
block job can be woken up. If that block job completes and also needs
to call bdrv_reopen() it can happen that it needs to do it on the same
BlockDriverState that is still in the process of being reopened.

This can have fatal consequences, like in this example:

  1) Block job A starts and sleeps after a while.
  2) Block job B starts and tries to reopen node1 (a qcow2 file).
  3) Reopening node1 means flushing and replacing its qcow2 cache.
  4) While the qcow2 cache is being flushed, job A wakes up.
  5) Job A completes and reopens node1, replacing its cache.
  6) Job B resumes, but the cache that was being flushed no longer
     exists.

This patch splits the bdrv_drain_all() call to keep all block jobs
paused during bdrv_reopen_multiple(), so that step 4 can never happen
and the operation is safe.

Note that this scenario can only happen if both bdrv_reopen() calls
are made by block jobs on the same backing chain. Otherwise there's no
chance that the same BlockDriverState appears in both reopen queues.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-10-31 16:52:38 +01:00
Paolo Bonzini
c9d1a56174 block: only call aio_poll on the current thread's AioContext
aio_poll is not thread safe; for example bdrv_drain can hang if
the last in-flight I/O operation is completed in the I/O thread after
the main thread has checked bs->in_flight.

The bug remains latent as long as all of it is called within
aio_context_acquire/aio_context_release, but this will change soon.

To fix this, if bdrv_drain is called from outside the I/O thread,
signal the main AioContext through a dummy bottom half.  The event
loop then only runs in the I/O thread.

Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1477565348-5458-18-git-send-email-pbonzini@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
2016-10-28 21:50:18 +08:00
Paolo Bonzini
720150f318 block: prepare bdrv_reopen_multiple to release AioContext
After the next patch bdrv_drain_all will have to be called without holding any
AioContext.  Prepare to do this by adding an AioContext argument to
bdrv_reopen_multiple.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1477565348-5458-15-git-send-email-pbonzini@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
2016-10-28 21:50:18 +08:00
Kevin Wolf
2d76e724cf block: Add qdev ID to DEVICE_TRAY_MOVED
The event currently only contains the BlockBackend name. However, with
anonymous BlockBackends, this is always the empty string. Add the qdev
ID (or if none was given, the QOM path) so that the user can still see
which device caused the event.

Event generation has to be moved from bdrv_eject() to the BlockBackend
because the BDS doesn't know the attached device, but that's easy
because blk_eject() is the only user of it.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2016-10-07 13:34:22 +02:00
Kevin Wolf
c5f3014b82 block: Add bdrv_runtime_opts to query-command-line-options
Recently we moved a few options from QemuOptsLists in blockdev.c to
bdrv_runtime_opts in block.c in order to make them accissble using
blockdev-add. However, this has the side effect that these options are
missing from query-command-line-options now, and libvirt consequently
disables the corresponding feature.

This problem was reported as a regression for the 'discard' option,
introduced in commit 818584a4. However, it is more general than that.

Fix it by adding bdrv_runtime_opts to the list of QemuOptsLists that are
returned in query-command-line-options. For the future, libvirt is
advised to use QMP schema introspection for block device options.

Reported-by: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Tested-by: Michal Privoznik <mprivozn@redhat.com>
Tested-by: Gerd Hoffmann <kraxel@redhat.com>
2016-10-07 13:34:07 +02:00
Kevin Wolf
818584a43a block: Move 'discard' option to bdrv_open_common()
This enables its use for nested child nodes. The compatibility
between the 'discard' and 'detect-zeroes' setting is checked in
bdrv_open_common() now as the former setting isn't available before
calling bdrv_open() any more.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2016-09-29 14:13:39 +02:00
Kevin Wolf
692e01a27c block: Parse 'detect-zeroes' in bdrv_open_common()
Amongst others, this means that you can now use the 'detect-zeroes'
option for non-top-level nodes in blockdev-add, like the QAPI schema
promises.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2016-09-29 14:13:39 +02:00
Alberto Garcia
5b7ba05fe7 block: Don't queue the same BDS twice in bdrv_reopen_queue_child()
bdrv_reopen_queue_child() assumes that a BlockDriverState is never
added twice to BlockReopenQueue.

That's however not the case: commit_start() adds 'base' (and its
children) to a new reopen queue, and then 'overlay_bs' (and its
children, which include 'base') to the same queue. The effect of this
is that the first set of options is ignored and overriden by the
second.

We fixed this by swapping the order in which both BDSs were added to
the queue in 3db2bd5508. This patch
checks if a BDS is already in the reopen queue and keeps its options.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-09-23 13:36:10 +02:00
Alberto Garcia
f87a0e29a9 block: Add "read-only" to the options QDict
This adds the "read-only" option to the QDict. One important effect of
this change is that when a child inherits options from its parent, the
existing "read-only" mode can be preserved if it was explicitly set
previously.

This addresses scenarios like this:

   [E] <- [D] <- [C] <- [B] <- [A]

In this case, if we reopen [D] with read-only=off, and later reopen
[B], then [D] will not inherit read-only=on from its parent during the
bdrv_reopen_queue_child() stage.

The BDRV_O_RDWR flag is not removed yet, but its keep in sync with the
value of the "read-only" option.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-09-23 13:36:10 +02:00
Alberto Garcia
9b7e869167 block: Update bs->open_flags earlier in bdrv_open_common()
We're only doing this immediately before opening the image, but
bs->open_flags is used earlier in the function. At the moment this is
not causing problems because none of the checked flags are modified by
update_flags_from_options(), but this will change when we introduce
the "read-only" option.

This patch calls update_flags_from_options() at the beginning of the
function, immediately after creating the QemuOpts.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-09-23 13:36:10 +02:00
Alberto Garcia
14499ea541 block: Set BDRV_O_ALLOW_RDWR and snapshot_options before storing the flags
If an image is opened with snapshot=on, its flags are modified by
bdrv_backing_options() and then bs->open_flags is updated accordingly.
This last step is unnecessary if we calculate the new flags before
setting bs->open_flags.

Soon we'll introduce the "read-only" option, and then we'll need to
be able to modify its value in the QDict when snapshot=on. This is
more cumbersome if bs->options is already set. This patch simplifies
that. Other than that, there are no semantic changes. Although it
might seem that bs->options can have a different value now because
it is stored after calling bdrv_backing_options(), this call doesn't
actually modify them in this scenario.

The code that sets BDRV_O_ALLOW_RDWR is also moved for the same
reason.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-09-23 13:36:10 +02:00
Alberto Garcia
38b5e4c3dc block: Remove bdrv_is_snapshot
This is unnecessary and has been unused since 5433c24f0f.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-09-23 13:36:10 +02:00
Marc Mari
88d88798b7 blockdev: Add dynamic module loading for block drivers
Extend the current module interface to allow for block drivers to be
loaded dynamically on request. The only block drivers that can be
converted into modules are the drivers that don't perform any init
operation except for registering themselves.

In addition, only the protocol drivers are being modularized, as they
are the only ones which see significant performance benefits. The format
drivers do not generally link to external libraries, so modularizing
them is of no benefit from a performance perspective.

All the necessary module information is located in a new structure found
in module_block.h

This spoils the purpose of 5505e8b76f (block/dmg: make it modular).

Before this patch, if module build is enabled, block-dmg.so is linked to
libbz2, whereas the main binary is not. In downstream, theoretically, it
means only the qemu-block-extra package depends on libbz2, while the
main QEMU package needn't to. With this patch, we (temporarily) change
the case so that the main QEMU depends on libbz2 again.

Signed-off-by: Marc Marí <markmb@redhat.com>
Signed-off-by: Colin Lord <clord@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 1471008424-16465-4-git-send-email-clord@redhat.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
[mreitz: Do a signed comparison against the length of
 block_driver_modules[], so it will not cause a compile error when
 empty]
Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-09-20 22:12:03 +02:00
Wen Congyang
e9d6456e95 block: unblock backup operations in backing file
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Changlong Xie <xiecl.fnst@cn.fujitsu.com>
Signed-off-by: Wang WeiWei <wangww.fnst@cn.fujitsu.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Kashyap Chamarthy <kchamart@redhat.com>
Message-id: 1469602913-20979-2-git-send-email-xiecl.fnst@cn.fujitsu.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-09-13 11:00:56 +01:00
Kevin Wolf
cd7fca952c nbd-server: Use a separate BlockBackend
The builtin NBD server uses its own BlockBackend now instead of reusing
the monitor/guest device one.

This means that it has its own writethrough setting now. The builtin
NBD server always uses writeback caching now regardless of whether the
guest device has WCE enabled. qemu-nbd respects the cache mode given on
the command line.

We still need to keep a reference to the monitor BB because we put an
eject notifier on it, but we don't use it for any I/O.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2016-09-05 19:06:47 +02:00
Denis V. Lunev
2f0342efdb block: remove extra condition in bdrv_can_write_zeroes_with_unmap
All .bdrv_co_write_zeroes callbacks nowadays work perfectly even
with backing store attached. If future new callbacks would be unable to do
that - they have a chance to block this in bdrv_get_info().

Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Message-id: 1468503209-19498-6-git-send-email-den@openvz.org
CC: Stefan Hajnoczi <stefanha@redhat.com>
CC: Kevin Wolf <kwolf@redhat.com>
CC: Max Reitz <mreitz@redhat.com>
CC: Jeff Cody <jcody@redhat.com>
Signed-off-by: Jeff Cody <jcody@redhat.com>
2016-07-19 16:54:46 -04:00
Evgeny Yakovlev
3ff2f67a7c block: ignore flush requests when storage is clean
Some guests (win2008 server for example) do a lot of unnecessary
flushing when underlying media has not changed. This adds additional
overhead on host when calling fsync/fdatasync.

This change introduces a write generation scheme in BlockDriverState.
Current write generation is checked against last flushed generation to
avoid unnessesary flushes.

The problem with excessive flushing was found by a performance test
which does parallel directory tree creation (from 2 processes).
Results improved from 0.424 loops/sec to 0.432 loops/sec.
Each loop creates 10^3 directories with 10 files in each.

This affected some blkdebug testcases that were expecting error logs from
failure-injected flushes which are now skipped entirely
(tests 026 071 089).

This also affects the performance of block jobs and thus BLOCK_JOB_READY
events for driver-mirror and active block-commit commands now arrives
faster, before QMP send successfully returns to caller (tests 141 144).

Signed-off-by: Evgeny Yakovlev <eyakovlev@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 1468870792-7411-5-git-send-email-den@openvz.org
CC: Kevin Wolf <kwolf@redhat.com>
CC: Max Reitz <mreitz@redhat.com>
CC: Stefan Hajnoczi <stefanha@redhat.com>
CC: Fam Zheng <famz@redhat.com>
CC: John Snow <jsnow@redhat.com>
Signed-off-by: John Snow <jsnow@redhat.com>
2016-07-18 18:19:01 -04:00
Paolo Bonzini
0b8b8753e4 coroutine: move entry argument to qemu_coroutine_create
In practice the entry argument is always known at creation time, and
it is confusing that sometimes qemu_coroutine_enter is used with a
non-NULL argument to re-enter a coroutine (this happens in
block/sheepdog.c and tests/test-coroutine.c).  So pass the opaque value
at creation time, for consistency with e.g. aio_bh_new.

Mostly done with the following semantic patch:

@ entry1 @
expression entry, arg, co;
@@
- co = qemu_coroutine_create(entry);
+ co = qemu_coroutine_create(entry, arg);
  ...
- qemu_coroutine_enter(co, arg);
+ qemu_coroutine_enter(co);

@ entry2 @
expression entry, arg;
identifier co;
@@
- Coroutine *co = qemu_coroutine_create(entry);
+ Coroutine *co = qemu_coroutine_create(entry, arg);
  ...
- qemu_coroutine_enter(co, arg);
+ qemu_coroutine_enter(co);

@ entry3 @
expression entry, arg;
@@
- qemu_coroutine_enter(qemu_coroutine_create(entry), arg);
+ qemu_coroutine_enter(qemu_coroutine_create(entry, arg));

@ reentry @
expression co;
@@
- qemu_coroutine_enter(co, NULL);
+ qemu_coroutine_enter(co);

except for the aforementioned few places where the semantic patch
stumbled (as expected) and for test_co_queue, which would otherwise
produce an uninitialized variable warning.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-07-13 13:26:02 +02:00
Kevin Wolf
cf2ab8fc34 block: Convert bdrv_pread(v) to BdrvChild
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-05 16:46:27 +02:00
Kevin Wolf
83fd6dd3e7 block: Move bdrv_commit() to block/commit.c
No code changes, just moved from one file to another.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-05 16:46:27 +02:00
Eric Blake
5411541270 block: Use bool as appropriate for BDS members
Using int for values that are only used as booleans is confusing.
While at it, rearrange a couple of members so that all the bools
are contiguous.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-07-05 16:46:26 +02:00
Eric Blake
a5b8dd2ce8 block: Move request_alignment into BlockLimit
It makes more sense to have ALL block size limit constraints
in the same struct.  Improve the documentation while at it.

Simplify a couple of conditionals, now that we have audited and
documented that request_alignment is always non-zero.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-07-05 16:46:26 +02:00
Eric Blake
79ba8c986a block: Set default request_alignment during bdrv_refresh_limits()
We want to eventually stick request_alignment alongside other
BlockLimits, but first, we must ensure it is populated at the
same time as all other limits, rather than being a special case
that is set only when a block is first opened.

Now that all drivers have been updated to supply an override
of request_alignment during their .bdrv_refresh_limits(), as
needed, the block layer itself can defer setting the default
alignment until part of the overall bdrv_refresh_limits().

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-07-05 16:46:25 +02:00
Peter Maydell
7fa124b273 Error reporting patches for 2016-06-20
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Merge remote-tracking branch 'remotes/armbru/tags/pull-error-2016-06-20' into staging

Error reporting patches for 2016-06-20

# gpg: Signature made Mon 20 Jun 2016 15:56:15 BST
# gpg:                using RSA key 0x3870B400EB918653
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>"
# gpg:                 aka "Markus Armbruster <armbru@pond.sub.org>"
# Primary key fingerprint: 354B C8B3 D7EB 2A6B 6867  4E5F 3870 B400 EB91 8653

* remotes/armbru/tags/pull-error-2016-06-20:
  log: Fix qemu_set_log_filename() error handling
  log: Fix qemu_set_dfilter_ranges() error reporting
  log: Plug memory leak on multiple -dfilter
  coccinelle: Remove unnecessary variables for function return value
  error: Remove unnecessary local_err variables
  error: Remove NULL checks on error_propagate() calls
  vl: Error messages need to go to stderr, fix some

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2016-06-20 16:19:18 +01:00
Eduardo Habkost
621ff94d50 error: Remove NULL checks on error_propagate() calls
error_propagate() already ignores local_err==NULL, so there's no
need to check it before calling.

Coccinelle patch used to perform the changes added to
scripts/coccinelle/error_propagate_null.cocci.

Reviewed-by: Eric Blake <eblake@redhat.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <1465855078-19435-2-git-send-email-ehabkost@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2016-06-20 16:38:13 +02:00
Stefan Hajnoczi
e8a095dadb block: use safe iteration over AioContext notifiers
It's possible that an AioContext notifier user was close to finishing
when .detach_aio_context() or .attached_aio_context() is called.  In
that case they may call bdrv_remove_aio_context_notifier() during the
callback.

Use safe iteration to avoid crashing when the notifier list is modified
during iteration.  We must not only handle the case where the current
aio notifier is removed during a callback but also the one where any
other aio notifier is removed.

The next patch adds an AioContext notifier for block jobs and they
really could be terminating just as .detach_aio_context() is invoked.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Message-id: 1466096189-6477-6-git-send-email-stefanha@redhat.com
2016-06-20 14:25:41 +01:00
Max Reitz
274fccee2b block/mirror: Fix target backing BDS
Currently, we are trying to move the backing BDS from the source to the
target in bdrv_replace_in_backing_chain() which is called from
mirror_exit(). However, mirror_complete() already tries to open the
target's backing chain with a call to bdrv_open_backing_file().

First, we should only set the target's backing BDS once. Second, the
mirroring block job has a better idea of what to set it to than the
generic code in bdrv_replace_in_backing_chain() (in fact, the latter's
conditions on when to move the backing BDS from source to target are not
really correct).

Therefore, remove that code from bdrv_replace_in_backing_chain() and
leave it to mirror_complete().

Depending on what kind of mirroring is performed, we furthermore want to
use different strategies to open the target's backing chain:

- If blockdev-mirror is used, we can assume the user made sure that the
  target already has the correct backing chain. In particular, we should
  not try to open a backing file if the target does not have any yet.

- If drive-mirror with mode=absolute-paths is used, we can and should
  reuse the already existing chain of nodes that the source BDS is in.
  In case of sync=full, no backing BDS is required; with sync=top, we
  just link the source's backing BDS to the target, and with sync=none,
  we use the source BDS as the target's backing BDS.
  We should not try to open these backing files anew because this would
  lead to two BDSs existing per physical file in the backing chain, and
  we would like to avoid such concurrent access.

- If drive-mirror with mode=existing is used, we have to use the
  information provided in the physical image file which means opening
  the target's backing chain completely anew, just as it has been done
  already.
  If the target's backing chain shares images with the source, this may
  lead to multiple BDSs per physical image file. But since we cannot
  reliably ascertain this case, there is nothing we can do about it.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20160610185750.30956-3-mreitz@redhat.com
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-06-16 15:20:37 +02:00
Max Reitz
9bd910e2cb block: Allow replacement of a BDS by its overlay
change_parent_backing_link() asserts that the BDS to be replaced is not
used as a backing file. However, we may want to replace a BDS by its
overlay in which case that very link should not be redirected.

For instance, when doing a sync=none drive-mirror operation, we may have
the following BDS/BB forest before block job completion:

  target

  base <- source <- BlockBackend

During job completion, we want to establish the source BDS as the
target's backing node:

          target
            |
            v
  base <- source <- BlockBackend

This makes the target a valid replacement for the source:

          target <- BlockBackend
            |
            v
  base <- source

Without this modification to change_parent_backing_link() we have to
inject the target into the graph before the source is its backing node,
thus temporarily creating a wrong graph:

  target <- BlockBackend

  base <- source

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20160610185750.30956-2-mreitz@redhat.com
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-06-16 15:20:37 +02:00
Kevin Wolf
418690447a block: Fix snapshot=on with aio=native
snapshot=on creates a temporary overlay that is always opened with
cache=unsafe (the cache mode specified by the user is only for the
actual image file and its children). This means that we must not inherit
the BDRV_O_NATIVE_AIO flag for the temporary overlay because trying to
use Linux AIO with cache=unsafe results in an error.

Reproducer without this patch:

$ x86_64-softmmu/qemu-system-x86_64 -drive file=/tmp/test.qcow2,cache=none,aio=native,snapshot=on
qemu-system-x86_64: -drive file=/tmp/test.qcow2,cache=none,aio=native,snapshot=on: aio=native was
specified, but it requires cache.direct=on, which was not specified.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-06-16 15:19:56 +02:00
Kevin Wolf
c9d20029f4 block: Remove bs->zero_beyond_eof
It is always true for open images now.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-06-16 15:19:56 +02:00
Kevin Wolf
23b0d9fb1d block: Don't enforce 512 byte minimum alignment
If block drivers say that they can do an alignment < 512 bytes, let's
just suppose they mean it. raw-posix used to be an offender with respect
to this, but it can actually deal with byte-aligned requests now.

The default is still 512 bytes for any drivers that only implement
sector-based interfaces, but it is 1 now for drivers that implement
.bdrv_co_preadv.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-06-16 15:19:55 +02:00
Peter Lieven
107d433cbb block: assert that bs->request_alignment is a power of 2
at least bdrv_co_preadv/pwritev expect this.

Signed-off-by: Peter Lieven <pl@kamp.de>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-06-08 10:21:09 +02:00
Kevin Wolf
a1a2af0756 block: Cancel jobs first in bdrv_close_all()
So far, bdrv_close_all() first removed all root BlockDriverStates of
BlockBackends and monitor owned BDSes, and then assumed that the
remaining BDSes must be related to jobs and cancelled these jobs.

This order doesn't work that well any more when block jobs use
BlockBackends internally because then they will lose their BDS before
being cancelled.

This patch changes bdrv_close_all() to first cancel all jobs and then
remove all root BDSes from the remaining BBs.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2016-05-25 19:04:21 +02:00
Kevin Wolf
20018e12cf block: Propagate .drained_begin/end callbacks
When draining intermediate nodes (i.e. nodes that aren't the root node
for at least one of their parents; with node references, the user can
always configure the graph to create this situation), we need to
propagate the .drained_begin/end callbacks all the way up to the root
for the drain to be effective.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
2016-05-25 19:04:11 +02:00
Kevin Wolf
36fe13317b block: Fix reconfiguring graph with drained nodes
When changing the BlockDriverState that a BdrvChild points to while the
node is currently drained, we must call the .drained_end() parent
callback. Conversely, when this means attaching a new node that is
already drained, we need to call .drained_begin().

bdrv_root_attach_child() takes now an opaque parameter, which is needed
because the callbacks must also be called if we're attaching a new child
to the BlockBackend when the root node is already drained, and they need
a way to identify the BlockBackend. Previously, child->opaque was set
too late and the callbacks would still see it as NULL.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
2016-05-25 19:04:10 +02:00
Kevin Wolf
e9740bc6d4 block: Introduce bdrv_replace_child()
This adds a common function that is called when attaching a new child to
a parent, removing a child from a parent and when reconfiguring the
graph so that an existing child points to a different node now.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
2016-05-25 19:04:10 +02:00
Max Reitz
6b574e09b3 block: Drop bdrv_parent_cb_...() from bdrv_close()
bdrv_close() now asserts that the BDS's refcount is 0, therefore it
cannot have any parents and the bdrv_parent_cb_change_media() call is a
no-op.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-05-25 19:04:10 +02:00
Max Reitz
30f55fb81f block: Assert !bs->refcnt in bdrv_close()
The only caller of bdrv_close() left is bdrv_delete(). We may as well
assert that, in a way (there are some things in bdrv_close() that make
more sense under that assumption, such as the call to
bdrv_release_all_dirty_bitmaps() which in turn assumes that no frozen
bitmaps are attached to the BDS).

In addition, being called only in bdrv_delete() means that we can drop
bdrv_close()'s forward declaration at the top of block.c.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-05-25 19:04:10 +02:00
Max Reitz
5b3639371c block: Make bdrv_open() return a BDS
There are no callers to bdrv_open() or bdrv_open_inherit() left that
pass a pointer to a non-NULL BDS pointer as the first argument of these
functions, so we can finally drop that parameter and just make them
return the new BDS.

Generally, the following pattern is applied:

    bs = NULL;
    ret = bdrv_open(&bs, ..., &local_err);
    if (ret < 0) {
        error_propagate(errp, local_err);
        ...
    }

by

    bs = bdrv_open(..., errp);
    if (!bs) {
        ret = -EINVAL;
        ...
    }

Of course, there are only a few instances where the pattern is really
pure.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-05-25 19:04:10 +02:00
Max Reitz
9bddf75979 block: Drop bdrv_new_root()
It is unused now, so we may just as well drop it.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-05-25 19:04:10 +02:00
Max Reitz
668361898e block: Let bdrv_open_inherit() return the snapshot
If bdrv_open_inherit() creates a snapshot BDS and *pbs is NULL, that
snapshot BDS should be returned instead of the BDS under it.

This has worked so far because (nearly) all users of BDRV_O_SNAPSHOT use
blk_new_open() to create the BDS tree. bdrv_append() (which is called by
bdrv_append_temp_snapshot()) redirects pointers from parents (i.e. the
BB in this case) to the newly appended child (i.e. the overlay),
therefore, while bdrv_open_inherit() did not return the root BDS, the BB
still pointed to it.

The only instance where BDRV_O_SNAPSHOT is used but blk_new_open() is
not is in blockdev_init() if no BDS tree is created, and instead
blk_new() is used and the flags are stored in the BB root state.
However, qmp_blockdev_change_medium() filters the BDRV_O_SNAPSHOT flag
before invoking bdrv_open(), so it will not have any effect.

In any case, it would be nicer if bdrv_open_inherit() could just always
return the root of the BDS tree that has been created.

To this end, bdrv_append_temp_snapshot() now returns the snapshot BDS
instead of just appending it on top of the snapshotted BDS. Also, it
calls bdrv_ref() before bdrv_append() (which bdrv_open_inherit() has to
undo if not returning the overlay).

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-05-25 19:04:10 +02:00
Max Reitz
506f8709ce block: Drop useless bdrv_new() call
bdrv_append_temp_snapshot() uses bdrv_new() to create an empty BDS
before invoking bdrv_open() on that BDS. This is probably a relict from
when it used to do some modifications on that empty BDS, but now that is
unnecessary, so we can just set bs_snapshot to NULL and let bdrv_open()
do the rest.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-05-25 19:04:10 +02:00
Kevin Wolf
88be7b4be4 block: Fix bdrv_next() memory leak
The bdrv_next() users all leaked the BdrvNextIterator after completing
the iteration. Simply changing bdrv_next() to free the iterator before
returning NULL at the end of list doesn't work because some callers exit
the loop before looking at all BDSes.

This patch moves the BdrvNextIterator from the heap to the stack of
the caller and switches to a bdrv_first()/bdrv_next() interface for
initialising the iterator.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
2016-05-25 19:04:10 +02:00
Max Reitz
b97511c7bc block: Propagate AioContext change to all children
Instead of propagating any change of a BDS's AioContext only to its file
and backing children and letting driver-specific code do the rest, just
propagate it to all and drop the thus superfluous implementations of
bdrv_{at,de}tach_aio_context() in Quorum, blkverify and VMDK.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-05-19 16:45:31 +02:00
Kevin Wolf
1f0c461b82 block: Remove BlockDriverState.blk
This patch removes the remaining users of bs->blk, which will allow us
to have multiple BBs on top of a single BDS. In the meantime, all checks
that are currently in place to prevent the user from creating such
setups can be switched to bdrv_has_blk() instead of accessing BDS.blk.

Future patches can allow them and e.g. enable users to mirror to a block
device that already has a BlockBackend on it.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2016-05-19 16:45:31 +02:00
Kevin Wolf
7c8eece45b block: Avoid bs->blk in bdrv_next()
We need to introduce a separate BdrvNextIterator struct that can keep
more state than just the current BDS in order to avoid using the bs->blk
pointer.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2016-05-19 16:45:31 +02:00
Kevin Wolf
4c265bf9f4 block: User BdrvChild callback for device name
In order to get rid of bs->blk for bdrv_get_device_name() and
bdrv_get_device_or_node_name(), ask all parents for their name and
simply pick the first one.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2016-05-19 16:45:31 +02:00
Kevin Wolf
5c8cab4808 block: Use BdrvChild callbacks for change_media/resize
We want to get rid of BlockDriverState.blk in order to allow multiple
BlockBackends per BDS. Converting the device callbacks in block.c (which
assume a single BlockBackend) to per-child callbacks gets us rid of the
first few instances.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2016-05-19 16:45:31 +02:00
Kevin Wolf
b26ded9a7d Revert "block: Forbid I/O throttling on nodes with multiple parents for 2.6"
This reverts commit 76b223200e.

Now that I/O throttling is fully done on the BlockBackend level, there
is no reason any more to block I/O throttling for nodes with multiple
parents as the parents don't influence each other any more.

Conflicts:
	block.c

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-05-19 16:45:31 +02:00
Kevin Wolf
08e83aabe4 block: Remove bdrv_move_feature_fields()
bdrv_move_feature_fields() and swap_feature_fields() are empty now, they
can be removed.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-05-19 16:45:31 +02:00
Kevin Wolf
7ca7f0f6db block: Decouple throttling from BlockDriverState
This moves the throttling related part of the BDS life cycle management
to BlockBackend. The throttling group reference is now kept even when no
medium is inserted.

With this commit, throttling isn't disabled and then re-enabled any more
during graph reconfiguration. This fixes the temporary breakage of I/O
throttling when used with live snapshots or block jobs that manipulate
the graph.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-05-19 16:45:30 +02:00
Kevin Wolf
97148076e8 block: Move I/O throttling configuration functions to BlockBackend
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-05-19 16:45:30 +02:00
Kevin Wolf
27ccdd5259 block: Move throttling fields from BDS to BB
This patch changes where the throttling state is stored (used to be the
BlockDriverState, now it is the BlockBackend), but it doesn't actually
make it a BB level feature yet. For example, throttling is still
disabled when the BDS is detached from the BB.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-05-19 16:45:30 +02:00
Kevin Wolf
a5614993d7 block: Make sure throttled BDSes always have a BB
It was already true in principle that a throttled BDS always has a BB
attached, except that the order of operations while attaching or
detaching a BDS to/from a BB wasn't careful enough.

This commit breaks graph manipulations while I/O throttling is enabled.
It would have been possible to keep things working with some temporary
hacks, but quite cumbersome, so it's not worth the hassle. We'll fix
things again in a minute.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-05-19 16:45:29 +02:00
Wen Congyang
98292c61bc quorum: implement bdrv_add_child() and bdrv_del_child()
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Changlong Xie <xiecl.fnst@cn.fujitsu.com>
Message-id: 1462865799-19402-3-git-send-email-xiecl.fnst@cn.fujitsu.com
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-05-12 15:33:23 +02:00
Wen Congyang
e06018ad28 Add new block driver interface to add/delete a BDS's child
In some cases, we want to take a quorum child offline, and take
another child online.

Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Changlong Xie <xiecl.fnst@cn.fujitsu.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 1462865799-19402-2-git-send-email-xiecl.fnst@cn.fujitsu.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-05-12 15:33:23 +02:00
Fam Zheng
aad0b7a0bf block: Inactivate all children
Currently we only inactivate the top BDS. Actually bdrv_inactivate
should be the opposite of bdrv_invalidate_cache.

Recurse into the whole subtree instead.

Because a node may have multiple parents, and because once
BDRV_O_INACTIVE is set for a node, further writes are not allowed, we
cannot interleave flag settings and .bdrv_inactivate calls (that may
submit write to other nodes in a graph) within a single pass. Therefore
two passes are used here.

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-05-12 15:22:09 +02:00
Fam Zheng
0d1c5c9160 block: Invalidate all children
Currently we only recurse to bs->file, which will miss the children in quorum
and VMDK.

Recurse into the whole subtree to avoid that.

Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-05-12 15:22:09 +02:00
Kevin Wolf
e3ddef25e9 block: Remove BlockDriver.bdrv_read/write
There are no block drivers left that implement the old .bdrv_read/write
interface, so it can be removed now. This gets us rid of the
corresponding emulation functions, too.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
2016-05-12 15:22:08 +02:00
Paolo Bonzini
ce0f141259 block: introduce bdrv_no_throttling_begin/end
Extract the handling of throttling from bdrv_flush_io_queue.  These
new functions will soon become BdrvChildRole callbacks, as they can
be generalized to "beginning of drain" and "end of drain".

Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-05-12 15:22:07 +02:00
Kevin Wolf
76b223200e block: Forbid I/O throttling on nodes with multiple parents for 2.6
As the patches to move I/O throttling to BlockBackend didn't make it in
time for the 2.6 release, but the release adds new ways of configuring
VMs whose behaviour would change once the move is done, we need to
outlaw such configurations temporarily.

The problem exists whenever a BDS has more users than just its BB, for
example it is used as a backing file for another node. (This wasn't
possible in 2.5 yet as we introduced node references to specify a
backing file only recently.) In these cases, the throttling would
apply to these other users now, but after moving throttling to the
BlockBackend the other users wouldn't be throttled any more.

This patch prevents making new references to a throttled node as well as
using monitor commands to throttle a node with multiple parents.

Compared to 2.5 this changes behaviour in some corner cases where
references were allowed before, like bs->file or Quorum children. It
seems reasonable to assume that users didn't use I/O throttling on such
low level nodes. With the upcoming move of throttling into BlockBackend,
such configurations won't be possible anyway.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2016-04-05 09:22:28 +02:00
Kevin Wolf
09cf9db1bc block: Remove bdrv_(set_)enable_write_cache()
The only remaining users were block jobs (mirror and backup) which
unconditionally enabled WCE on the BlockBackend of the target image. As
these block jobs don't go through BlockBackend for their I/O requests,
they aren't affected by this setting anyway but always get a writeback
mode, so that call can be removed.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2016-03-30 12:16:03 +02:00
Kevin Wolf
61de4c6808 block: Remove BDRV_O_CACHE_WB
The previous patches have successively made blk->enable_write_cache the
true source for the information whether a writethrough mode must be
implemented. The corresponding BDRV_O_CACHE_WB is only useless baggage
we're carrying around, so now's the time to remove it.

At the same time, we remove the 'cache.writeback' option parsing on the
BDS level as the only effect was setting the BDRV_O_CACHE_WB flag.

This change requires test cases that explicitly enabled the option to
drop it. Other than that and the change of the error message when
writethrough is enabled on the BDS level (from "Can't set writethrough
mode" to "doesn't support the option"), there should be no change in
behaviour.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2016-03-30 12:16:03 +02:00
Kevin Wolf
53e8ae0100 block: Remove bdrv_parse_cache_flags()
All users are converted to bdrv_parse_cache_mode() now.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2016-03-30 12:16:03 +02:00
Kevin Wolf
19dbecdcee qemu-io: Use bdrv_parse_cache_mode() in reopen_f()
We must forbid changing the WCE flag in bdrv_reopen() in the same patch,
as otherwise the behaviour would change so that the flag takes
precedence over the explicitly specified option.

The correct value of the WCE flag depends on the BlockBackend user (e.g.
guest device) and isn't a decision that the QMP client makes, so this
change is what we want.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2016-03-30 12:16:03 +02:00
Kevin Wolf
c83f9fba2a block/qapi: Use blk_enable_write_cache()
Now that WCE is handled on the BlockBackend level, the flag is
meaningless for BDSes. As the schema requires us to fill the field,
we return an enabled write cache for them.

Note that this means that querying the BlockBackend name may return
writethrough as the cache information, whereas querying the node-name of
the root of that same BlockBackend will return writeback.

This may appear odd at first, but it actually makes sense because it
correctly repesents the layer that implements the WCE handling. This
becomes more apparent when you consider nodes that are the root node of
multiple BlockBackends, where each BB can have its own WCE setting.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2016-03-30 12:16:02 +02:00
Kevin Wolf
bfd18d1e0b block: Move enable_write_cache to BB level
Whether a write cache is used or not is a decision that concerns the
user (e.g. the guest device) rather than the backend. It was already
logically part of the BB level as bdrv_move_feature_fields() always kept
it on top of the BDS tree; with this patch, the core of it (the actual
flag and the additional flushes) is also implemented there.

Direct callers of bdrv_open() must pass BDRV_O_CACHE_WB now if bs
doesn't have a BlockBackend attached.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2016-03-30 12:16:02 +02:00
Kevin Wolf
baf5602ed9 block: Add bdrv_parse_cache_mode()
It's like bdrv_parse_cache_flags(), except that writethrough mode isn't
included in the flags, but returned as a separate bool.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2016-03-30 12:16:00 +02:00