In the context of backup fleecing, discarding the source will not work
when the fleecing image has a larger granularity than the one used for
block-copy operations (can happen if the backup target has smaller
cluster size), because cbw_co_pdiscard_snapshot() will align down the
discard requests and thus effectively ignore then.
To make @discard-source work in such a scenario, allow specifying the
minimum cluster size used for block-copy operations and thus in
particular also the granularity for discard requests to the source.
Suggested-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Acked-by: Markus Armbruster <armbru@redhat.com> (QAPI schema)
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
Message-Id: <20240711120915.310243-3-f.ebner@proxmox.com>
[vsementsov: switch version to 9.2 in QAPI doc]
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Add a parameter that enables discard-after-copy. That is mostly useful
in "push backup with fleecing" scheme, when source is snapshot-access
format driver node, based on copy-before-write filter snapshot-access
API:
[guest] [snapshot-access] ~~ blockdev-backup ~~> [backup target]
| |
| root | file
v v
[copy-before-write]
| |
| file | target
v v
[active disk] [temp.img]
In this case discard-after-copy does two things:
- discard data in temp.img to save disk space
- avoid further copy-before-write operation in discarded area
Note that we have to declare WRITE permission on source in
copy-before-write filter, for discard to work. Still we can't take it
unconditionally, as it will break normal backup from RO source. So, we
have to add a parameter and pass it thorough bdrv_open flags.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Reviewed-by: Fiona Ebner <f.ebner@proxmox.com>
Tested-by: Fiona Ebner <f.ebner@proxmox.com>
Acked-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20240313152822.626493-5-vsementsov@yandex-team.ru>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Stop acquiring/releasing the AioContext lock in
bdrv_graph_wrlock()/bdrv_graph_unlock() since the lock no longer has any
effect.
The distinction between bdrv_graph_wrunlock() and
bdrv_graph_wrunlock_ctx() becomes meaningless and they can be collapsed
into one function.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20231205182011.1976568-6-stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
bdrv_graph_wrunlock() calls aio_poll(), which may run callbacks that
have a nested event loop. Nested event loops can depend on other
iothreads making progress, so in order to allow them to make progress it
must not hold the AioContext lock of another thread while calling
aio_poll().
This introduces a @bs parameter to bdrv_graph_wrunlock() whose
AioContext is temporarily dropped (which matches bdrv_graph_wrlock()),
and a bdrv_graph_wrunlock_ctx() that can be used if the BlockDriverState
doesn't necessarily exist any more when unlocking.
This also requires a change to bdrv_schedule_unref(), which was relying
on the incorrectly taken lock. It needs to take the lock itself now.
While this is a separate bug, it can't be fixed a separate patch because
otherwise the intermediate state would either deadlock or try to release
a lock that we don't even hold.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20231115172012.112727-3-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
[kwolf: Fixed up bdrv_schedule_unref()]
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Instead of taking the writer lock internally, require callers to already
hold it when calling block_job_add_bdrv(). These callers will typically
already hold the graph lock once the locking work is completed, which
means that they can't call functions that take it internally.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20231027155333.420094-6-kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_get_parent_name() need to hold a reader lock for the graph
because it accesses the parents list of a node.
For some places, we know that they will hold the lock, but we don't have
the GRAPH_RDLOCK annotations yet. In this case, add assume_graph_lock()
with a FIXME comment. These places will be removed once everything is
properly annotated.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230929145157.45443-13-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_co_block_status() need to hold a reader lock for the graph.
For some places, we know that they will hold the lock, but we don't have
the GRAPH_RDLOCK annotations yet. In this case, add assume_graph_lock()
with a FIXME comment. These places will be removed once everything is
properly annotated.
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230203152202.49054-5-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20230207075115.1525-2-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Konstantin Kostiuk <kkostiuk@redhat.com>
We have two inclusion loops:
block/block.h
-> block/block-global-state.h
-> block/block-common.h
-> block/blockjob.h
-> block/block.h
block/block.h
-> block/block-io.h
-> block/block-common.h
-> block/blockjob.h
-> block/block.h
I believe these go back to Emanuele's reorganization of the block API,
merged a few months ago in commit d7e2fe4aac.
Fortunately, breaking them is merely a matter of deleting unnecessary
includes from headers, and adding them back in places where they are
now missing.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20221221133551.3967339-2-armbru@redhat.com>
The .set_speed callback is not called from coroutine.
Signed-off-by: Alberto Faria <afaria@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20221013123711.620631-2-pbonzini@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We have too much logic to simply check that bitmaps are of the same
size. Let's just define that hbitmap_merge() and
bdrv_dirty_bitmap_merge_internal() require their argument bitmaps be of
same size, this simplifies things.
Let's look through the callers:
For backup_init_bcs_bitmap() we already assert that merge can't fail.
In bdrv_reclaim_dirty_bitmap_locked() we gracefully handle the error
that can't happen: successor always has same size as its parent, drop
this logic.
In bdrv_merge_dirty_bitmap() we already has assertion and separate
check. Make the check explicit and improve error message.
Signed-off-by: Vladimir Sementsov-Ogievskiy <v.sementsov-og@mail.ru>
Reviewed-by: Nikita Lapshin <nikita.lapshin@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20220517111206.23585-4-v.sementsov-og@mail.ru>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Message-Id: <20220303151616.325444-13-eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We largely have two cancel modes for jobs:
First, there is actual cancelling. The job is terminated as soon as
possible, without trying to reach a consistent result.
Second, we have mirror in the READY state. Technically, the job is not
really cancelled, but it just is a different completion mode. The job
can still run for an indefinite amount of time while it tries to reach a
consistent result.
We want to be able to clearly distinguish which cancel mode a job is in
(when it has been cancelled). We can use Job.force_cancel for this, but
right now it only reflects cancel requests from the user with
force=true, but clearly, jobs that do not even distinguish between
force=false and force=true are effectively always force-cancelled.
So this patch has Job.force_cancel signify whether the job will
terminate as soon as possible (force_cancel=true) or whether it will
effectively remain running despite being "cancelled"
(force_cancel=false).
To this end, we let jobs that provide JobDriver.cancel() tell the
generic job code whether they will terminate as soon as possible or not,
and for jobs that do not provide that method we assume they will.
Signed-off-by: Hanna Reitz <hreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20211006151940.214590-7-hreitz@redhat.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
QAPI generates `struct BackupPerf` where `max-workers` value is stored
in an `int64_t` variable.
But block_copy_async(), and the underlying code, uses an `int` parameter.
At the end that variable is used to initialize `max_busy_tasks` in
block/aio_task.c causing the following assertion failure if a value
greater than INT_MAX(2147483647) is used:
../block/aio_task.c:63: aio_task_pool_wait_one: Assertion `pool->busy_tasks > 0' failed.
Let's check that `max-workers` doesn't exceed INT_MAX and print an
error in that case.
Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=2009310
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20211005161157.282396-2-sgarzare@redhat.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
We are going to publish copy-before-write filter to be used in separate
of backup. Future step would support bitmap for the filter. But let's
start from full set bitmap.
We have to modify backup, as bitmap is first initialized by
copy-before-write filter, and then backup modifies it.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20210824083856.17408-20-vsementsov@virtuozzo.com>
Signed-off-by: Hanna Reitz <hreitz@redhat.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Message-Id: <20210824083856.17408-18-vsementsov@virtuozzo.com>
Signed-off-by: Hanna Reitz <hreitz@redhat.com>
The main consumer of cluster-size is block-copy. Let's calculate it
here instead of passing through backup-top.
We are going to publish copy-before-write filter soon, so it will be
created through options. But we don't want for now to make explicit
option for cluster-size, let's continue to calculate it automatically.
So, now is the time to get rid of cluster_size argument for
bdrv_cbw_append().
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20210824083856.17408-10-vsementsov@virtuozzo.com>
[hreitz: Add qemu/error-report.h include to block/block-copy.c]
Signed-off-by: Hanna Reitz <hreitz@redhat.com>
We are going to publish copy-before-write filter, so it would be
initialized through options. Still we don't want to publish compress
and copy-range options, as
1. Modern way to enable compression is to use compress filter.
2. For copy-range it's unclean how to make proper interface:
- it's has experimental prefix for backup job anyway
- the whole BackupPerf structure doesn't make sense for the filter
So, let's just add copy-range possibility to the filter later if
needed.
Still, we are going to continue support for compression and
experimental copy-range in backup job. So, set these options after
filter creation.
Note, that we can drop "compress" argument of bdrv_cbw_append() now, as
well as "perf". The only reason not doing so is that now, when I
prepare this patch the big series around it is already reviewed and I
want to avoid extra rebase conflicts to simplify review of the
following version.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Message-Id: <20210824083856.17408-9-vsementsov@virtuozzo.com>
Signed-off-by: Hanna Reitz <hreitz@redhat.com>
We want to simplify initialization interface of copy-before-write
filter as we are going to make it public. So, let's detect fleecing
scheme exactly in block-copy code, to not pass this information through
extra levels.
Why not just set BDRV_REQ_SERIALISING unconditionally: because we are
going to implement new more efficient fleecing scheme which will not
rely on backing feature.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Message-Id: <20210824083856.17408-7-vsementsov@virtuozzo.com>
Signed-off-by: Hanna Reitz <hreitz@redhat.com>
We are going to convert backup_top to full featured public filter,
which can be used in separate of backup job. Start from renaming from
"how it used" to "what it does".
While updating comments in 283 iotest, drop and rephrase also things
about ".active", as this field is now dropped, and filter doesn't have
"inactive" mode.
Note that this change may be considered as incompatible interface
change, as backup-top filter format name was visible through
query-block and query-named-block-nodes.
Still, consider the following reasoning:
1. backup-top was never documented, so if someone depends on format
name (for driver that can't be used other than it is automatically
inserted on backup job start), it's a kind of "undocumented feature
use". So I think we are free to change it.
2. There is a hope, that there is no such users: it's a lot more native
to give a good node-name to backup-top filter if need to operate
with it somehow, and don't touch format name.
3. Another "incompatible" change in further commit would be moving
copy-before-write filter from using backing child to file child. And
this is even more reasonable than renaming: for now all public
filters are file-child based.
So, it's a risky change, but risk seems small and good interface worth
it.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20210824083856.17408-6-vsementsov@virtuozzo.com>
Signed-off-by: Hanna Reitz <hreitz@redhat.com>
If mirror is READY than cancel operation is not discarding the whole
result of the operation, but instead it's a documented way get a
point-in-time snapshot of source disk.
So, we should not cancel any requests if mirror is READ and
force=false. Let's fix that case.
Note, that bug that we have before this commit is not critical, as the
only .bdrv_cancel_in_flight implementation is nbd_cancel_in_flight()
and it cancels only requests waiting for reconnection, so it should be
rare case.
Fixes: 521ff8b779
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210421075858.40197-1-vsementsov@virtuozzo.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
The block job holds a reference to the backup-top node (because it is
passed as the main job BDS to block_job_create()). Therefore,
bdrv_backup_top_drop() cannot delete the backup-top node (replacing it
by its child does not affect the job parent, because that has
.stay_at_node set). That is a problem, because all of its I/O functions
assume the BlockCopyState (s->bcs) to be valid and that it has a
filtered child; but after bdrv_backup_top_drop(), neither of those
things are true.
It does not make sense to add new parents to backup-top after
backup_clean(), so we should detach it from the job before
bdrv_backup_top_drop(). Because there is no function to do that for a
single node, just detach all of the job's nodes -- the job does not do
anything past backup_clean() anyway.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20210219153348.41861-2-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Cancel in-flight io on target to not waste the time.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210205163720.887197-10-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
This brings async request handling and block-status driven chunk sizes
to backup out of the box, which improves backup performance.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20210116214705.822267-18-vsementsov@virtuozzo.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20210116214705.822267-17-vsementsov@virtuozzo.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Add new parameters to configure future backup features. The patch
doesn't introduce aio backup requests (so we actually have only one
worker) neither requests larger than one cluster. Still, formally we
satisfy these maximums anyway, so add the parameters now, to facilitate
further patch which will really change backup job behavior.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20210116214705.822267-11-vsementsov@virtuozzo.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
We are going to directly use one async block-copy operation for backup
job, so we need rate limiter.
We want to maintain current backup behavior: only background copying is
limited and copy-before-write operations only participate in limit
calculation. Therefore we need one rate limiter for block-copy state
and boolean flag for block-copy call state for actual limitation.
Note, that we can't just calculate each chunk in limiter after
successful copying: it will not save us from starting a lot of async
sub-requests which will exceed limit too much. Instead let's use the
following scheme on sub-request creation:
1. If at the moment limit is not exceeded, create the request and
account it immediately.
2. If at the moment limit is already exceeded, drop create sub-request
and handle limit instead (by sleep).
With this approach we'll never exceed the limit more than by one
sub-request (which pretty much matches current backup behavior).
Note also, that if there is in-flight block-copy async call,
block_copy_kick() should be used after set-speed to apply new setup
faster. For that block_copy_kick() published in this patch.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20210116214705.822267-7-vsementsov@virtuozzo.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Experiments show, that copy_range is not always making things faster.
So, to make experimentation simpler, let's add a parameter. Some more
perf parameters will be added soon, so here is a new struct.
For now, add new backup qmp parameter with x- prefix for the following
reasons:
- We are going to add more performance parameters, some will be
related to the whole block-copy process, some only to background
copying in backup (ignored for copy-before-write operations).
- On the other hand, we are going to use block-copy interface in other
block jobs, which will need performance options as well.. And it
should be the same structure or at least somehow related.
So, there are too much unclean things about how the interface and now
we need the new options mostly for testing. Let's keep them
experimental for a while.
In do_backup_common() new x-perf parameter handled in a way to
make further options addition simpler.
We add use-copy-range with default=true, and we'll change the default
in further patch, after moving backup to use block-copy.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20210116214705.822267-2-vsementsov@virtuozzo.com>
[mreitz: s/5\.2/6.0/]
Signed-off-by: Max Reitz <mreitz@redhat.com>
Since the introduction of a backup filter node in commit 00e30f05d, the
backup block job crashes when the target image is smaller than the
source image because it will try to write after the end of the target
node without having BLK_PERM_RESIZE. (Previously, the BlockBackend layer
would have caught this and errored out gracefully.)
We can fix this and even do better than the old behaviour: Check that
source and target have the same image size at the start of the block job
and unshare BLK_PERM_RESIZE. (This permission was already unshared
before the same commit 00e30f05d, but the BlockBackend that was used to
make the restriction was removed without a replacement.) This will
immediately error out when starting the job instead of only when writing
to a block that doesn't exist in the target.
Longer target than source would technically work because we would never
write to blocks that don't exist, but semantically these are invalid,
too, because a backup is supposed to create a copy, not just an image
that starts with a copy.
Fixes: 00e30f05de
Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1778593
Cc: qemu-stable@nongnu.org
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200430142755.315494-4-kwolf@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
bdrv_get_device_name() will be an empty string with modern management
tools that don't use -drive. Use bdrv_get_device_or_node_name() instead
so that the node name is used if the BlockBackend is anonymous.
While at it, start with upper case to make the message consistent with
the rest of the function.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-Id: <20200430142755.315494-3-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
All code-paths leading to backup_clean (via job_clean) have the job's
context already acquired. The job's context is guaranteed to be the same
as the one used by backup_top via backup_job_create.
Since the previous logic effectively acquired the lock twice, this
broke cleanup of backups for disks using IO threads, since the BDRV_POLL_WHILE
in bdrv_backup_top_drop -> bdrv_do_drained_begin would only release the lock
once, thus deadlocking with the IO thread.
This is a partial revert of 0abf258171.
Signed-off-by: Stefan Reiter <s.reiter@proxmox.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200407115651.69472-4-s.reiter@proxmox.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Hide structure definitions and add explicit API instead, to keep an
eye on the scope of the shared fields.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200311103004.7649-10-vsementsov@virtuozzo.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Assume we have two regions, A and B, and region B is in-flight now,
region A is not yet touched, but it is unallocated and should be
skipped.
Correspondingly, as progress we have
total = A + B
current = 0
If we reset unallocated region A and call progress_reset_callback,
it will calculate 0 bytes dirty in the bitmap and call
job_progress_set_remaining, which will set
total = current + 0 = 0 + 0 = 0
So, B bytes are actually removed from total accounting. When job
finishes we'll have
total = 0
current = B
, which doesn't sound good.
This is because we didn't considered in-flight bytes, actually when
calculating remaining, we should have set (in_flight + dirty_bytes)
as remaining, not only dirty_bytes.
To fix it, let's refactor progress calculation, moving it to block-copy
itself instead of fixing callback. And, of course, track in_flight
bytes count.
We still have to keep one callback, to maintain backup job bytes_read
calculation, but it will go on soon, when we turn the whole backup
process into one block_copy call.
Cc: qemu-stable@nongnu.org
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Message-Id: <20200311103004.7649-3-vsementsov@virtuozzo.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
All paths that lead to bdrv_backup_top_drop(), except for the call
from backup_clean(), imply that the BDS AioContext has already been
acquired, so doing it there too can potentially lead to QEMU hanging
on AIO_WAIT_WHILE().
An easy way to trigger this situation is by issuing a two actions
transaction, with a proper and a bogus blockdev-backup, so the second
one will trigger a rollback. This will trigger a hang with an stack
trace like this one:
#0 0x00007fb680c75016 in __GI_ppoll (fds=0x55e74580f7c0, nfds=1, timeout=<optimized out>,
timeout@entry=0x0, sigmask=sigmask@entry=0x0) at ../sysdeps/unix/sysv/linux/ppoll.c:39
#1 0x000055e743386e09 in ppoll (__ss=0x0, __timeout=0x0, __nfds=<optimized out>, __fds=<optimized out>)
at /usr/include/bits/poll2.h:77
#2 0x000055e743386e09 in qemu_poll_ns
(fds=<optimized out>, nfds=<optimized out>, timeout=<optimized out>) at util/qemu-timer.c:336
#3 0x000055e743388dc4 in aio_poll (ctx=0x55e7458925d0, blocking=blocking@entry=true)
at util/aio-posix.c:669
#4 0x000055e743305dea in bdrv_flush (bs=bs@entry=0x55e74593c0d0) at block/io.c:2878
#5 0x000055e7432be58e in bdrv_close (bs=0x55e74593c0d0) at block.c:4017
#6 0x000055e7432be58e in bdrv_delete (bs=<optimized out>) at block.c:4262
#7 0x000055e7432be58e in bdrv_unref (bs=bs@entry=0x55e74593c0d0) at block.c:5644
#8 0x000055e743316b9b in bdrv_backup_top_drop (bs=bs@entry=0x55e74593c0d0) at block/backup-top.c:273
#9 0x000055e74331461f in backup_job_create
(job_id=0x0, bs=bs@entry=0x55e7458d5820, target=target@entry=0x55e74589f640, speed=0, sync_mode=MIRROR_SYNC_MODE_FULL, sync_bitmap=sync_bitmap@entry=0x0, bitmap_mode=BITMAP_SYNC_MODE_ON_SUCCESS, compress=false, filter_node_name=0x0, on_source_error=BLOCKDEV_ON_ERROR_REPORT, on_target_error=BLOCKDEV_ON_ERROR_REPORT, creation_flags=0, cb=0x0, opaque=0x0, txn=0x0, errp=0x7ffddfd1efb0) at block/backup.c:478
#10 0x000055e74315bc52 in do_backup_common
(backup=backup@entry=0x55e746c066d0, bs=bs@entry=0x55e7458d5820, target_bs=target_bs@entry=0x55e74589f640, aio_context=aio_context@entry=0x55e7458a91e0, txn=txn@entry=0x0, errp=errp@entry=0x7ffddfd1efb0)
at blockdev.c:3580
#11 0x000055e74315c37c in do_blockdev_backup
(backup=backup@entry=0x55e746c066d0, txn=0x0, errp=errp@entry=0x7ffddfd1efb0)
at /usr/src/debug/qemu-kvm-4.2.0-2.module+el8.2.0+5135+ed3b2489.x86_64/./qapi/qapi-types-block-core.h:1492
#12 0x000055e74315c449 in blockdev_backup_prepare (common=0x55e746a8de90, errp=0x7ffddfd1f018)
at blockdev.c:1885
#13 0x000055e743160152 in qmp_transaction
(dev_list=<optimized out>, has_props=<optimized out>, props=0x55e7467fe2c0, errp=errp@entry=0x7ffddfd1f088) at blockdev.c:2340
#14 0x000055e743287ff5 in qmp_marshal_transaction
(args=<optimized out>, ret=<optimized out>, errp=0x7ffddfd1f0f8)
at qapi/qapi-commands-transaction.c:44
#15 0x000055e74333de6c in do_qmp_dispatch
(errp=0x7ffddfd1f0f0, allow_oob=<optimized out>, request=<optimized out>, cmds=0x55e743c28d60 <qmp_commands>) at qapi/qmp-dispatch.c:132
#16 0x000055e74333de6c in qmp_dispatch
(cmds=0x55e743c28d60 <qmp_commands>, request=<optimized out>, allow_oob=<optimized out>)
at qapi/qmp-dispatch.c:175
#17 0x000055e74325c061 in monitor_qmp_dispatch (mon=0x55e745908030, req=<optimized out>)
at monitor/qmp.c:145
#18 0x000055e74325c6fa in monitor_qmp_bh_dispatcher (data=<optimized out>) at monitor/qmp.c:234
#19 0x000055e743385866 in aio_bh_call (bh=0x55e745807ae0) at util/async.c:117
#20 0x000055e743385866 in aio_bh_poll (ctx=ctx@entry=0x55e7458067a0) at util/async.c:117
#21 0x000055e743388c54 in aio_dispatch (ctx=0x55e7458067a0) at util/aio-posix.c:459
#22 0x000055e743385742 in aio_ctx_dispatch
(source=<optimized out>, callback=<optimized out>, user_data=<optimized out>) at util/async.c:260
#23 0x00007fb68543e67d in g_main_dispatch (context=0x55e745893a40) at gmain.c:3176
#24 0x00007fb68543e67d in g_main_context_dispatch (context=context@entry=0x55e745893a40) at gmain.c:3829
#25 0x000055e743387d08 in glib_pollfds_poll () at util/main-loop.c:219
#26 0x000055e743387d08 in os_host_main_loop_wait (timeout=<optimized out>) at util/main-loop.c:242
#27 0x000055e743387d08 in main_loop_wait (nonblocking=<optimized out>) at util/main-loop.c:518
#28 0x000055e74316a3c1 in main_loop () at vl.c:1828
#29 0x000055e743016a72 in main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>)
at vl.c:4504
Fix this by not acquiring the AioContext there, and ensuring all paths
leading to it have it already acquired (backup_clean()).
RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=1782111
Signed-off-by: Sergio Lopez <slp@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
After commit 00e30f05de, there is no more "goto error" points
after job creation, so after "error:" @job is always NULL and we don't
need roll-back job creation.
Reported-by: Coverity (CID 1406402)
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Acked-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Add bs field to BdrvDirtyBitmap structure. Drop BlockDriverState
parameter from bitmap APIs where possible.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 20190916141911.5255-3-vsementsov@virtuozzo.com
[Rebased on top of block-copy. --js]
Signed-off-by: John Snow <jsnow@redhat.com>
Drop write notifiers and use filter node instead.
= Changes =
1. Add filter-node-name argument for backup qmp api. We have to do it
in this commit, as 257 needs to be fixed.
2. There are no more write notifiers here, so is_write_notifier
parameter is dropped from block-copy paths.
3. To sync with in-flight requests at job finish we now have drained
removing of the filter, we don't need rw-lock.
4. Block-copy is now using BdrvChildren instead of BlockBackends
5. As backup-top owns these children, we also move block-copy state
into backup-top's ownership.
= Iotest changes =
56: op-blocker doesn't shoot now, as we set it on source, but then
check on filter, when trying to start second backup.
To keep the test we instead can catch another collision: both jobs will
get 'drive0' job-id, as job-id parameter is unspecified. To prevent
interleaving with file-posix locks (as they are dependent on config)
let's use another target for second backup.
Also, it's obvious now that we'd like to drop this op-blocker at all
and add a test-case for two backups from one node (to different
destinations) actually works. But not in these series.
141: Output changed: prepatch, "Node is in use" comes from bdrv_has_blk
check inside qmp_blockdev_del. But we've dropped block-copy blk
objects, so no more blk objects on source bs (job blk is on backup-top
filter bs). New message is from op-blocker, which is the next check in
qmp_blockdev_add.
257: The test wants to emulate guest write during backup. They should
go to filter node, not to original source node, of course. Therefore we
need to specify filter node name and use it.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20191001131409.14202-6-vsementsov@virtuozzo.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Split block_copy_set_callbacks out of block_copy_state_new. It's needed
for further commit: block-copy will use BdrvChildren of backup-top
filter, so it will be created from backup-top filter creation function.
But callbacks will still belong to backup job and will be set in
separate.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20191001131409.14202-4-vsementsov@virtuozzo.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
This is logic-less refactoring, which simplifies further patch, as
we'll need write_flags for backup-top filter creation and backup-top
should be created before block job creation.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20191001131409.14202-3-vsementsov@virtuozzo.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Move synchronization mechanism to block-copy, to be able to use one
block-copy instance from backup job and backup-top filter in parallel.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20191001131409.14202-2-vsementsov@virtuozzo.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Split block_copy to separate file, to be cleanly shared with backup-top
filter driver in further commits.
It's a clean movement, the only change is drop "static" from interface
functions.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190920142056.12778-8-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
We need to fix comment style around block-copy functions before further
moving them to separate file to satisfy checkpatch. But do more: fix
all comments style. Also, seems like doubled first asterisk is not
forbidden, but drop it too for consistency.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190920142056.12778-7-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
Split copying code part from backup to "block-copy", including separate
state structure and function renaming. This is needed to share it with
backup-top filter driver in further commits.
Notes:
1. As BlockCopyState keeps own BlockBackend objects, remaining
job->common.blk users only use it to get bs by blk_bs() call, so clear
job->commen.blk permissions set in block_job_create and add
job->source_bs to be used instead of blk_bs(job->common.blk), to keep
it more clear which bs we use when introduce backup-top filter in
further commit.
2. Rename s/initializing_bitmap/skip_unallocated/ to sound a bit better
as interface to BlockCopyState
3. Split is not very clean: there left some duplicated fields, backup
code uses some BlockCopyState fields directly, let's postpone it for
further improvements and keep this comment simpler for review.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20190920142056.12778-6-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190920142056.12778-5-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
Split copying logic which will be shared with backup-top filter.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190920142056.12778-4-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
We shouldn't try to copy bytes beyond EOF. Fix it.
Fixes: 9ded4a0114
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: 20190920142056.12778-3-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
Of course, QEMU_ALIGN_UP is a typo, it should be QEMU_ALIGN_DOWN, as we
are trying to find aligned size which satisfy both source and target.
Also, don't ignore too small max_transfer. In this case seems safer to
disable copy_range.
Fixes: 9ded4a0114
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20190920142056.12778-2-vsementsov@virtuozzo.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>
