It's better to use accessor function instead of bs->read_only directly.
In some places use bdrv_is_writable() instead of
checking both BDRV_O_RDWR set and BDRV_O_INACTIVE not set.
In bdrv_open_common() it's a bit strange to add one more variable, but
we are going to drop bs->read_only in the next patch, so new ro local
variable substitutes it here.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210527154056.70294-2-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We have too much comments for this feature. It seems better just don't
do it. Most of real users (tests don't count) have to create additional
reference.
Drop also comment in external_snapshot_prepare:
- bdrv_append doesn't "remove" old bs in common sense, it sounds
strange
- the fact that bdrv_append can fail is obvious from the context
- the fact that we must rollback all changes in transaction abort is
known (it's the direct role of abort)
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-5-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
When checking for allocation across a chain, it's already easy to
count the depth within the chain at which the allocation is found.
Instead of throwing that information away, return it to the caller.
Existing callers only cared about allocated/non-allocated, but having
a depth available will be used by NBD in the next patch.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20201027050556.269064-9-eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
[eblake: rebase to master]
Signed-off-by: Eric Blake <eblake@redhat.com>
With bdrv_filter_bs(), we can easily handle this default filter behavior
in bdrv_co_block_status().
blkdebug wants to have an additional assertion, so it keeps its own
implementation, except bdrv_co_block_status_from_file() needs to be
inlined there.
Suggested-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
This includes some permission limiting (for example, we only need to
take the RESIZE permission if the base is smaller than the top).
Signed-off-by: Max Reitz <mreitz@redhat.com>
This structure nearly only contains parent callbacks for child state
changes. It cannot really reflect a child's role, because different
roles may overlap (as we will see when real roles are introduced), and
because parents can have custom callbacks even when the child fulfills a
standard role.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-Id: <20200513110544.176672-4-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
bdrv_commit() already has a BlockBackend pointing to the BDS that we
want to empty, it just has the wrong permissions.
qemu-img commit has no BlockBackend pointing to the old backing file
yet, but introducing one is simple.
After this commit, bdrv_make_empty() is the only remaining caller of
BlockDriver.bdrv_make_empty().
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200429141126.85159-5-mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[kwolf: Fixed up reference output for 098]
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
block_job_error_action() needs to know if reading from the top node or
writing to the base node failed so that it can set the right 'operation'
in the BLOCK_JOB_ERROR QMP event.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200214200812.28180-6-kwolf@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
commit_populate() is a very short function and only called in a single
place. Its return value doesn't tell us whether an error happened while
reading or writing, which would be necessary for sending the right data
in the BLOCK_JOB_ERROR QMP event.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200214200812.28180-5-kwolf@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The block_job_error_action() error call in the commit job gives the
on_err and is_read arguments in the wrong order. Fix this.
(Of course, hard-coded is_read = false is wrong, too, but that's a
separate problem for a separate patch.)
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200214200812.28180-4-kwolf@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We have two drivers (iscsi and file-posix) that (in some cases) return
success from their .bdrv_co_truncate() implementation if the block
device is larger than the requested offset, but cannot be shrunk. Some
callers do not want that behavior, so this patch adds a new parameter
that they can use to turn off that behavior.
This patch just adds the parameter and lets the block/io.c and
block/block-backend.c functions pass it around. All other callers
always pass false and none of the implementations evaluate it, so that
this patch does not change existing behavior. Future patches take care
of that.
Suggested-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190918095144.955-5-mreitz@redhat.com
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
In job_finish_sync job_enter should be enough for a job to make some
progress and draining is a wrong tool for it. So use job_enter directly
here and drop job_drain with all related staff not used more.
Suggested-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Tested-by: John Snow <jsnow@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This fixes devices like IDE that can still start new requests from I/O
handlers in the CPU thread while the block backend is drained.
The basic assumption is that in a drain section, no new requests should
be allowed through a BlockBackend (blk_drained_begin/end don't exist,
we get drain sections only on the node level). However, there are two
special cases where requests should not be queued:
1. Block jobs: We already make sure that block jobs are paused in a
drain section, so they won't start new requests. However, if the
drain_begin is called on the job's BlockBackend first, it can happen
that we deadlock because the job stays busy until it reaches a pause
point - which it can't if its requests aren't processed any more.
The proper solution here would be to make all requests through the
job's filter node instead of using a BlockBackend. For now, just
disabling request queuing on the job BlockBackend is simpler.
2. In test cases where making requests through bdrv_* would be
cumbersome because we'd need a BdrvChild. As we already got the
functionality to disable request queuing from 1., use it in tests,
too, for convenience.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
The commit and the mirror block job must be able to drop their filter
node at any point. However, this will not be possible if any of the
BdrvChild links to them is frozen. Therefore, we need to prevent them
from ever becoming frozen.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20190703172813.6868-2-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
This patch is used in the 'block/stream: introduce a bottom node'
that is following. Instead of the base node, the caller may pass
the node that has the base as its backing image to the function
bdrv_is_allocated_above() with a new parameter include_base = true
and get rid of the dependency on the base that may change during
commit/stream parallel jobs. Now, if the specified base is not
found in the backing image chain, the QEMU will abort.
Suggested-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 1559152576-281803-2-git-send-email-andrey.shinkevich@virtuozzo.com
[mreitz: Squashed in the following as a rebase on conflicting patches:]
Message-id: e3cf99ae-62e9-8b6e-5a06-d3c8b9363b85@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
commit_top_bs never requests or unshares any permissions. There is no
reason to make this so explicit here.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The mirror and commit block jobs use bdrv_set_aio_context() to move
their filter node into the right AioContext before hooking it up in the
graph. Similarly, bdrv_open_backing_file() explicitly moves the backing
file node into the right AioContext first.
This isn't necessary any more, they get automatically moved into the
right context now when attaching them.
However, in the case of bdrv_open_backing_file() with a node reference,
it's actually not only unnecessary, but even wrong: The unchecked
bdrv_set_aio_context() changes the AioContext of the child node even if
other parents require it to retain the old context. So this is not only
a simplification, but a bug fix, too.
Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1684342
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This adds a new parameter to blk_new() which requires its callers to
declare from which AioContext this BlockBackend is going to be used (or
the locks of which AioContext need to be taken anyway).
The given context is only stored and kept up to date when changing
AioContexts. Actually applying the stored AioContext to the root node
is saved for another commit.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Vladimir Sementsov-OgievskiyandKevin Wolf
Max ReitzandKevin Wolf
Andrey ShinkevichandMax Reitz
Alberto GarciaandMax Reitz