Let start from the beginning:
Commit b9e413dd37 (in 2.9)
"block: explicitly acquire aiocontext in aio callbacks that need it"
added pairs of aio_context_acquire/release to mirror_write_complete and
mirror_read_complete, when they were aio callbacks for blk_aio_* calls.
Then, commit 2e1990b26e (in 3.0) "block/mirror: Convert to coroutines"
dropped these blk_aio_* calls, than mirror_write_complete and
mirror_read_complete are not callbacks more, and don't need additional
aiocontext acquiring. Furthermore, mirror_read_complete calls
blk_co_pwritev inside these pair of aio_context_acquire/release, which
leads to the following dead-lock with mirror:
(gdb) info thr
Id Target Id Frame
3 Thread (LWP 145412) "qemu-system-x86" syscall ()
2 Thread (LWP 145416) "qemu-system-x86" __lll_lock_wait ()
* 1 Thread (LWP 145411) "qemu-system-x86" __lll_lock_wait ()
(gdb) bt
#0 __lll_lock_wait ()
#1 _L_lock_812 ()
#2 __GI___pthread_mutex_lock
#3 qemu_mutex_lock_impl (mutex=0x561032dce420 <qemu_global_mutex>,
file=0x5610327d8654 "util/main-loop.c", line=236) at
util/qemu-thread-posix.c:66
#4 qemu_mutex_lock_iothread_impl
#5 os_host_main_loop_wait (timeout=480116000) at util/main-loop.c:236
#6 main_loop_wait (nonblocking=0) at util/main-loop.c:497
#7 main_loop () at vl.c:1892
#8 main
Printing contents of qemu_global_mutex, I see that "__owner = 145416",
so, thr1 is main loop, and now it wants BQL, which is owned by thr2.
(gdb) thr 2
(gdb) bt
#0 __lll_lock_wait ()
#1 _L_lock_870 ()
#2 __GI___pthread_mutex_lock
#3 qemu_mutex_lock_impl (mutex=0x561034d25dc0, ...
#4 aio_context_acquire (ctx=0x561034d25d60)
#5 dma_blk_cb
#6 dma_blk_io
#7 dma_blk_read
#8 ide_dma_cb
#9 bmdma_cmd_writeb
#10 bmdma_write
#11 memory_region_write_accessor
#12 access_with_adjusted_size
#15 flatview_write
#16 address_space_write
#17 address_space_rw
#18 kvm_handle_io
#19 kvm_cpu_exec
#20 qemu_kvm_cpu_thread_fn
#21 qemu_thread_start
#22 start_thread
#23 clone ()
Printing mutex in fr 2, I see "__owner = 145411", so thr2 wants aio
context mutex, which is owned by thr1. Classic dead-lock.
Then, let's check that aio context is hold by mirror coroutine: just
print coroutine stack of first tracked request in mirror job target:
(gdb) [...]
(gdb) qemu coroutine 0x561035dd0860
#0 qemu_coroutine_switch
#1 qemu_coroutine_yield
#2 qemu_co_mutex_lock_slowpath
#3 qemu_co_mutex_lock
#4 qcow2_co_pwritev
#5 bdrv_driver_pwritev
#6 bdrv_aligned_pwritev
#7 bdrv_co_pwritev
#8 blk_co_pwritev
#9 mirror_read_complete () at block/mirror.c:232
#10 mirror_co_read () at block/mirror.c:370
#11 coroutine_trampoline
#12 __start_context
Yes it is mirror_read_complete calling blk_co_pwritev after acquiring
aio context.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
For purposes of minimum code movement, refactor the mirror_exit
callback to use the post-finalization callbacks in a trivial way.
Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 20180906130225.5118-7-jsnow@redhat.com
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
[mreitz: Added comment for the mirror_exit() function]
Signed-off-by: Max Reitz <mreitz@redhat.com>
In cases where we abort the block/mirror job, there's no point in
installing the new backing chain before we finish aborting.
Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 20180906130225.5118-6-jsnow@redhat.com
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Add support for taking and passing forward job creation flags.
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Message-id: 20180906130225.5118-3-jsnow@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
Change the manual deferment to mirror_exit into the implicit
callback to job_exit and the mirror_exit callback.
This does change the order of some bdrv_unref calls and job_completed,
but thanks to the new context in which we call .exit, this is safe to
defer the possible flushing of any nodes to the job_finalize_single
cleanup stage.
Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 20180830015734.19765-6-jsnow@redhat.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Jobs presently use both an Error object in the case of the create job,
and char strings in the case of generic errors elsewhere.
Unify the two paths as just j->err, and remove the extra argument from
job_completed. The integer error code for job_completed is kept for now,
to be removed shortly in a separate patch.
Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 20180830015734.19765-3-jsnow@redhat.com
[mreitz: Dropped a superfluous g_strdup()]
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Presently we codify the entry point for a job as the "start" callback,
but a more apt name would be "run" to clarify the idea that when this
function returns we consider the job to have "finished," except for
any cleanup which occurs in separate callbacks later.
As part of this clarification, change the signature to include an error
object and a return code. The error ptr is not yet used, and the return
code while captured, will be overwritten by actions in the job_completed
function.
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20180830015734.19765-2-jsnow@redhat.com
Reviewed-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
.bdrv_close handler is optional after previous commit, no needs to keep
empty functions more.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
blockdev-mirror with the same node for source and target segfaults
today: A node is in its own backing chain, so mirror_start_job() decides
that this is an active commit. When adding the intermediate nodes with
block_job_add_bdrv(), it starts the iteration through the subchain with
the backing file of source, though, so it never reaches target and
instead runs into NULL at the base.
While we could fix that by starting with source itself, there is no
point in allowing mirroring a node into itself and I wouldn't be
surprised if this caused more problems later.
So just check for this scenario and error out.
Cc: qemu-stable@nongnu.org
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Other I/O functions are already using a BdrvChild pointer in the API, so
make discard do the same. It makes it possible to initiate the same
permission checks before doing I/O, and much easier to share the
helper functions for this, which will be added and used by write,
truncate and copy range paths.
Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This patch allows the user to specify whether to use active or only
background mode for mirror block jobs. Currently, this setting will
remain constant for the duration of the entire block job.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20180613181823.13618-14-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
This patch implements active synchronous mirroring. In active mode, the
passive mechanism will still be in place and is used to copy all
initially dirty clusters off the source disk; but every write request
will write data both to the source and the target disk, so the source
cannot be dirtied faster than data is mirrored to the target. Also,
once the block job has converged (BLOCK_JOB_READY sent), source and
target are guaranteed to stay in sync (unless an error occurs).
Active mode is completely optional and currently disabled at runtime. A
later patch will add a way for users to enable it.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Message-id: 20180613181823.13618-13-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
This will allow us to access the block job data when the mirror block
driver becomes more complex.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Message-id: 20180613181823.13618-11-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
With this, the mirror_top_bs is no longer just a technically required
node in the BDS graph but actually represents the block job operation.
Also, drop MirrorBlockJob.source, as we can reach it through
mirror_top_bs->backing.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20180613181823.13618-6-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
This patch makes the mirror code differentiate between simply waiting
for any operation to complete (mirror_wait_for_free_in_flight_slot())
and specifically waiting for all operations touching a certain range of
the virtual disk to complete (mirror_wait_on_conflicts()).
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Message-id: 20180613181823.13618-5-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
Attach a CoQueue to each in-flight operation so if we need to wait for
any we can use it to wait instead of just blindly yielding and hoping
for some operation to wake us.
A later patch will use this infrastructure to allow requests accessing
the same area of the virtual disk to specifically wait for each other.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Message-id: 20180613181823.13618-4-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
In order to talk to the source BDS (and maybe in the future to the
target BDS as well) directly, we need to convert our existing AIO
requests into coroutine I/O requests.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Message-id: 20180613181823.13618-3-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
When converting mirror's I/O to coroutines, we are going to need a point
where these coroutines are created. mirror_perform() is going to be
that point.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20180613181823.13618-2-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
We already requested that block jobs be paused in .bdrv_drained_begin,
but no guarantee was made that the job was actually inactive at the
point where bdrv_drained_begin() returned.
This introduces a new callback BdrvChildRole.bdrv_drained_poll() and
uses it to make bdrv_drain_poll() consider block jobs using the node to
be drained.
For the test case to work as expected, we have to switch from
block_job_sleep_ns() to qemu_co_sleep_ns() so that the test job is even
considered active and must be waited for when draining the node.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
So far we relied on job->ret and strerror() to produce an error message
for failed jobs. Not surprisingly, this tends to result in completely
useless messages.
This adds a Job.error field that can contain an error string for a
failing job, and a parameter to job_completed() that sets the field. As
a default, if NULL is passed, we continue to use strerror(job->ret).
All existing callers are changed to pass NULL. They can be improved in
separate patches.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
BlockJob has fields .offset and .len, which are actually misnomers today
because they are no longer tied to block device sizes, but just progress
counters. As such they make a lot of sense in generic Jobs.
This patch moves the fields to Job and renames them to .progress_current
and .progress_total to describe their function better.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
The transition to the READY state was still performed in the BlockJob
layer, in the same function that sent the BLOCK_JOB_READY QMP event.
This patch brings the state transition to the Job layer and implements
the QMP event using a notifier called from the Job layer, like we
already do for other events related to state transitions.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
This moves the .complete callback that tells a READY job to complete
from BlockJobDriver to JobDriver. The wrapper function job_complete()
doesn't require anything block job specific any more and can be moved
to Job.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
block_job_drain() contains a blk_drain() call which cannot be moved to
Job, so add a new JobDriver callback JobDriver.drain which has a common
implementation for all BlockJobs. In addition to this we keep the
existing BlockJobDriver.drain callback that is called by the common
drain implementation for all block jobs.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
block_job_cancel_async() did two things that were still block job
specific:
* Setting job->force. This field makes sense on the Job level, so we can
just move it. While at it, rename it to job->force_cancel to make its
purpose more obvious.
* Resetting the I/O status. This can't be moved because generic Jobs
don't have an I/O status. What the function really implements is a
user resume, except without entering the coroutine. Consequently, it
makes sense to call the .user_resume driver callback here which
already resets the I/O status.
The old block_job_cancel_async() has two separate if statements that
check job->iostatus != BLOCK_DEVICE_IO_STATUS_OK and job->user_paused.
However, the former condition always implies the latter (as is
asserted in block_job_iostatus_reset()), so changing the explicit call
of block_job_iostatus_reset() on the former condition with the
.user_resume callback on the latter condition is equivalent and
doesn't need to access any BlockJob specific state.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
This moves the finalisation of a single job from BlockJob to Job.
Some part of this code depends on job transactions, and job transactions
call this code, we introduce some temporary calls from Job functions to
BlockJob ones. This will be fixed once transactions move to Job, too.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
This renames the BlockJobCreateFlags constants, moves a few JOB_INTERNAL
checks to job_create() and the auto_{finalize,dismiss} fields from
BlockJob to Job.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
While we already moved the state related to job pausing to Job, the
functions to do were still BlockJob only. This commit moves them over to
Job.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
There is nothing block layer specific about block_job_sleep_ns(), so
move the function to Job.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
This commit moves some core functions for dealing with the job coroutine
from BlockJob to Job. This includes primarily entering the coroutine
(both for the first and reentering) and yielding explicitly and at pause
points.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Move the defer_to_main_loop functionality from BlockJob to Job.
The code can be simplified because we can use job->aio_context in
job_defer_to_main_loop_bh() now, instead of having to access the
BlockDriverState.
Probably taking the data->aio_context lock in addition was already
unnecessary in the old code because we didn't actually make use of
anything protected by the old AioContext except getting the new
AioContext, in case it changed between scheduling the BH and running it.
But it's certainly unnecessary now that the BDS isn't accessed at all
any more.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
We cannot yet move the whole logic around job cancelling to Job because
it depends on quite a few other things that are still only in BlockJob,
but we can move the cancelled field at least.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
This moves reference counting from BlockJob to Job.
In order to keep calling the BlockJob cleanup code when the job is
deleted via job_unref(), introduce a new JobDriver.free callback. Every
block job must use block_job_free() for this callback, this is asserted
in block_job_create().
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
This moves the job_type field from BlockJobDriver to JobDriver.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
QAPI types aren't externally visible, so we can rename them without
causing problems. Before we add a job type to Job, rename the enum
so it can be used for more than just block jobs.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
This is the first step towards creating an infrastructure for generic
background jobs that aren't tied to a block device. For now, Job only
stores its ID and JobDriver, the rest stays in BlockJob.
The following patches will move over more parts of BlockJob to Job if
they are meaningful outside the context of a block job.
BlockJob.driver is now redundant, but this patch leaves it around to
avoid unnecessary churn. The next patches will get rid of almost all of
its uses anyway so that it can be removed later with much less churn.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Update the rest of the filter drivers to support
BDRV_REQ_WRITE_UNCHANGED. They already forward write request flags to
their children, so we just have to announce support for it.
This patch does not cover the replication driver because that currently
does not support flags at all, and because it just grabs the WRITE
permission for its children when it can, so we should be fine just
submitting the incoming WRITE_UNCHANGED requests as normal writes.
It also does not cover format drivers for similar reasons. They all use
bdrv_format_default_perms() as their .bdrv_child_perm() implementation
so they just always grab the WRITE permission for their file children
whenever possible. In addition, it often would be difficult to
ascertain whether incoming unchanging writes end up as unchanging writes
in their files. So we just leave them as normal potentially changing
writes.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20180421132929.21610-7-mreitz@redhat.com
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
This gets us rid of more direct accesses to BlockJob fields from the
job drivers.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
All block job drivers support .set_speed and all of them duplicate the
same code to implement it. Move that code to blockjob.c and remove the
now useless callback.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Every block job has a RateLimit, and they all do the exact same thing
with it, so it should be common infrastructure. Move the struct field
for a start.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Block job drivers are not expected to mess with the internals of the
BlockJob object, so provide wrapper functions for one of the cases where
they still do it: Updating the progress counter.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Commit b76e4458b1 made the mirror block
job respect block-job-cancel's @force flag: With that flag set, it would
now always really cancel, even post-READY.
Unfortunately, it had a side effect: Without that flag set, it would now
never cancel, not even before READY. Considering that is an
incompatible change and not noted anywhere in the commit or the
description of block-job-cancel's @force parameter, this seems
unintentional and we should revert to the previous behavior, which is to
immediately cancel the job when block-job-cancel is called before source
and target are in sync (i.e. before the READY event).
Cc: qemu-stable@nongnu.org
Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1572856
Reported-by: Yanan Fu <yfu@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20180501220509.14152-2-mreitz@redhat.com
Reviewed-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Jeff Cody <jcody@redhat.com>
Commit b76e4458b1 ("block/mirror: change
the semantic of 'force' of block-job-cancel") accidentally removed the
ratelimit in the mirror job.
Reintroduce the ratelimit but keep the block-job-cancel force=true
behavior that was added in commit
b76e4458b1.
Note that block_job_sleep_ns() returns immediately when the job is
cancelled. Therefore it's safe to unconditionally call
block_job_sleep_ns() - a cancelled job does not sleep.
This commit fixes the non-deterministic qemu-iotests 185 output. The
test relies on the ratelimit to make the job sleep until the 'quit'
command is processed. Previously the job could complete before the
'quit' command was received since there was no ratelimit.
Cc: Liang Li <liliang.opensource@gmail.com>
Cc: Jeff Cody <jcody@redhat.com>
Cc: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20180424123527.19168-1-stefanha@redhat.com
Signed-off-by: Jeff Cody <jcody@redhat.com>
When doing drive mirror to a low speed shared storage, if there was heavy
BLK IO write workload in VM after the 'ready' event, drive mirror block job
can't be canceled immediately, it would keep running until the heavy BLK IO
workload stopped in the VM.
Libvirt depends on the current block-job-cancel semantics, which is that
when used without a flag after the 'ready' event, the command blocks
until data is in sync. However, these semantics are awkward in other
situations, for example, people may use drive mirror for realtime
backups while still wanting to use block live migration. Libvirt cannot
start a block live migration while another drive mirror is in progress,
but the user would rather abandon the backup attempt as broken and
proceed with the live migration than be stuck waiting for the current
drive mirror backup to finish.
The drive-mirror command already includes a 'force' flag, which libvirt
does not use, although it documented the flag as only being useful to
quit a job which is paused. However, since quitting a paused job has
the same effect as abandoning a backup in a non-paused job (namely, the
destination file is not in sync, and the command completes immediately),
we can just improve the documentation to make the force flag obviously
useful.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Jeff Cody <jcody@redhat.com>
Cc: Kevin Wolf <kwolf@redhat.com>
Cc: Max Reitz <mreitz@redhat.com>
Cc: Eric Blake <eblake@redhat.com>
Cc: John Snow <jsnow@redhat.com>
Reported-by: Huaitong Han <huanhuaitong@didichuxing.com>
Signed-off-by: Huaitong Han <huanhuaitong@didichuxing.com>
Signed-off-by: Liang Li <liliangleo@didichuxing.com>
Signed-off-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
model all independent jobs as single job transactions.
It's one less case we have to worry about when we add more states to the
transition machine. This way, we can just treat all job lifetimes exactly
the same. This helps tighten assertions of the STM graph and removes some
conditionals that would have been needed in the coming commits adding a
more explicit job lifetime management API.
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We are gradually moving away from sector-based interfaces, towards
byte-based. Update the generic helpers, and all passthrough clients
(blkdebug, commit, mirror, throttle) accordingly.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
All callers are using QEMU_CLOCK_REALTIME, and it will not be possible to
support more than one clock when block_job_sleep_ns switches to a single
timer stored in the BlockJob struct.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Tested-By: Jeff Cody <jcody@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We are gradually moving away from sector-based interfaces, towards
byte-based. In the common case, allocation is unlikely to ever use
values that are not naturally sector-aligned, but it is possible
that byte-based values will let us be more precise about allocation
at the end of an unaligned file that can do byte-based access.
Changing the name of the function from bdrv_get_block_status_above()
to bdrv_block_status_above() ensures that the compiler enforces that
all callers are updated. Likewise, since it a byte interface allows
an offset mapping that might not be sector aligned, split the mapping
out of the return value and into a pass-by-reference parameter. For
now, the io.c layer still assert()s that all uses are sector-aligned,
but that can be relaxed when a later patch implements byte-based
block status in the drivers.
For the most part this patch is just the addition of scaling at the
callers followed by inverse scaling at bdrv_block_status(), plus
updates for the new split return interface. But some code,
particularly bdrv_block_status(), gets a lot simpler because it no
longer has to mess with sectors. Likewise, mirror code no longer
computes s->granularity >> BDRV_SECTOR_BITS, and can therefore drop
an assertion about alignment because the loop no longer depends on
alignment (never mind that we don't really have a driver that
reports sub-sector alignments, so it's not really possible to test
the effect of sub-sector mirroring). Fix a neighboring assertion to
use is_power_of_2 while there.
For ease of review, bdrv_get_block_status() was tackled separately.
Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
In the process of converting sector-based interfaces to bytes,
I'm finding it easier to represent a byte count as a 64-bit
integer at the block layer (even if we are internally capped
by SIZE_MAX or even INT_MAX for individual transactions, it's
still nicer to not have to worry about truncation/overflow
issues on as many variables). Update the signature of
bdrv_round_to_clusters() to uniformly use int64_t, matching
the signature already chosen for bdrv_is_allocated and the
fact that off_t is also a signed type, then adjust clients
according to the required fallout (even where the result could
now exceed 32 bits, no client is directly assigning the result
into a 32-bit value without breaking things into a loop first).
Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Not all callers care about which BDS owns the mapping for a given
range of the file. This patch merely simplifies the callers by
consolidating the logic in the common call point, while guaranteeing
a non-NULL file to all the driver callbacks, for no semantic change.
The only caller that does not care about pnum is bdrv_is_allocated,
as invoked by vvfat; we can likewise add assertions that the rest
of the stack does not have to worry about a NULL pnum.
Furthermore, this will also set the stage for a future cleanup: when
a caller does not care about which BDS owns an offset, it would be
nice to allow the driver to optimize things to not have to return
BDRV_BLOCK_OFFSET_VALID in the first place. In the case of fragmented
allocation (for example, it's fairly easy to create a qcow2 image
where consecutive guest addresses are not at consecutive host
addresses), the current contract requires bdrv_get_block_status()
to clamp *pnum to the limit where host addresses are no longer
consecutive, but allowing a NULL file means that *pnum could be
set to the full length of known-allocated data.
Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Backing may be zero after failed bdrv_append in mirror_start_job,
which leads to SIGSEGV.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20170929152255.5431-1-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
Backing may be zero after failed bdrv_attach_child in
bdrv_set_backing_hd, which leads to SIGSEGV.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20170928120300.58164-1-vsementsov@virtuozzo.com
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Now that we have adjusted the majority of the calls this function
makes to be byte-based, it is easier to read the code if it makes
passes over the image using bytes rather than sectors.
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>
Some of the callers were already scaling bytes to sectors; others
can be easily converted to pass byte offsets, all in our shift
towards a consistent byte interface everywhere. Making the change
will also make it easier to write the hold-out callers to use byte
rather than sectors for their iterations; it also makes it easier
for a future dirty-bitmap patch to offload scaling over to the
internal hbitmap. Although all callers happen to pass
sector-aligned values, make the internal scaling robust to any
sub-sector requests.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Half the callers were already scaling bytes to sectors; the other
half can eventually be simplified to use byte iteration. Both
callers were already using the result as a bool, so make that
explicit. Making the change also makes it easier for a future
dirty-bitmap patch to offload scaling over to the internal hbitmap.
Remember, asking whether a byte is dirty is effectively asking
whether the entire granularity containing the byte is dirty, since
we only track dirtiness by granularity.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Thanks to recent cleanups, all callers were scaling a return value
of sectors into bytes; do the scaling internally instead.
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>
Thanks to recent cleanups, most callers were scaling a return value
of sectors into bytes (the exception, in qcow2-bitmap, will be
converted to byte-based iteration later). Update the interface to
do the scaling internally instead.
In qcow2-bitmap, the code was specifically checking for an error
return of -1. To avoid a regression, we either have to make sure
we continue to return -1 (rather than a scaled -512) on error, or
we have to fix the caller to treat all negative values as error
rather than just one magic value. It's easy enough to make both
changes at the same time, even though either one in isolation
would work.
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>
All callers to bdrv_dirty_iter_new() passed 0 for their initial
starting point, drop that parameter.
Most callers to bdrv_set_dirty_iter() were scaling a byte offset to
a sector number; the exception qcow2-bitmap will be converted later
to use byte rather than sector iteration. Move the scaling to occur
internally to dirty bitmap code instead, so that callers now pass
in bytes.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
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>
bdrv_co_get_block_status_from_file() and
bdrv_co_get_block_status_from_backing() set *file to bs->file and
bs->backing respectively, so that bdrv_co_get_block_status() can recurse
to them. Future block drivers won't have to duplicate code to implement
this.
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Manos Pitsidianakis <el13635@mail.ntua.gr>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
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>
blk_truncate() itself will pass that value to bdrv_truncate(), and all
callers of blk_truncate() just set the parameter to PREALLOC_MODE_OFF
for now.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20170613202107.10125-4-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
We are gradually moving away from sector-based interfaces, towards
byte-based. In the common case, allocation is unlikely to ever use
values that are not naturally sector-aligned, but it is possible
that byte-based values will let us be more precise about allocation
at the end of an unaligned file that can do byte-based access.
Changing the signature of the function to use int64_t *pnum ensures
that the compiler enforces that all callers are updated. For now,
the io.c layer still assert()s that all callers are sector-aligned,
but that can be relaxed when a later patch implements byte-based
block status. Therefore, for the most part this patch is just the
addition of scaling at the callers followed by inverse scaling at
bdrv_is_allocated(). But some code, particularly stream_run(),
gets a lot simpler because it no longer has to mess with sectors.
Leave comments where we can further simplify by switching to
byte-based iterations, once later patches eliminate the need for
sector-aligned operations.
For ease of review, bdrv_is_allocated() was tackled separately.
Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We are gradually converting to byte-based interfaces, as they are
easier to reason about than sector-based. Change the internal
loop iteration of mirroring to track by bytes instead of sectors
(although we are still guaranteed that we iterate by steps that
are both sector-aligned and multiples of the granularity). Drop
the now-unused mirror_clip_sectors().
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We are gradually converting to byte-based interfaces, as they are
easier to reason about than sector-based. Convert another internal
function, preserving all existing semantics, and adding one more
assertion that things are still sector-aligned (so that conversions
to sectors in mirror_read_complete don't need to round).
Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We are gradually converting to byte-based interfaces, as they are
easier to reason about than sector-based. Convert another internal
function (no semantic change), and add mirror_clip_bytes() as a
counterpart to mirror_clip_sectors(). Some of the conversion is
a bit tricky, requiring temporaries to convert between units; it
will be cleared up in a following patch.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Rather than having a void function that modifies its input
in-place as the output, change the signature to reduce a layer
of indirection and return the result.
Suggested-by: John Snow <jsnow@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We are gradually converting to byte-based interfaces, as they are
easier to reason about than sector-based. Convert another internal
function (no semantic change).
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We are gradually converting to byte-based interfaces, as they are
easier to reason about than sector-based. Continue by converting an
internal structure (no semantic change), and all references to the
buffer size.
Add an assertion that our use of s->granularity >> BDRV_SECTOR_BITS
(necessary for interaction with sector-based dirty bitmaps, until
a later patch converts those to be byte-based) does not suffer from
truncation problems.
[checkpatch has a false positive on use of MIN() in this patch]
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Upcoming patches are going to switch to byte-based interfaces
instead of sector-based. Even worse, trace_backup_do_cow_enter()
had a weird mix of cluster and sector indices.
The trace interface is low enough that there are no stability
guarantees, and therefore nothing wrong with changing our units,
even in cases like trace_backup_do_cow_skip() where we are not
changing the trace output. So make the tracing uniformly use
bytes.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The user interface specifies job rate limits in bytes/second.
It's pointless to have our internal representation track things
in sectors/second, particularly since we want to move away from
sector-based interfaces.
Fix up a doc typo found while verifying that the ratelimit
code handles the scaling difference.
Repetition of expressions like 'n * BDRV_SECTOR_SIZE' will be
cleaned up later when functions are converted to iterate over
images by bytes rather than by sectors.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The lone caller that cares about a return of BDRV_BLOCK_RAW
(namely, io.c:bdrv_co_get_block_status) completely replaces the
return value, so there is no point in passing BDRV_BLOCK_DATA.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Change the 'int count' parameter in *pwrite_zeros, *pdiscard related
functions (and some others) to 'int bytes', as they both refer to bytes.
This helps with code legibility.
Signed-off-by: Manos Pitsidianakis <el13635@mail.ntua.gr>
Message-id: 20170609101808.13506-1-el13635@mail.ntua.gr
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
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>
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Merge remote-tracking branch 'kwolf/tags/for-upstream' into staging
Block layer patches
# gpg: Signature made Mon 29 May 2017 03:34:59 PM BST
# gpg: using RSA key 0x7F09B272C88F2FD6
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>"
# Primary key fingerprint: DC3D EB15 9A9A F95D 3D74 56FE 7F09 B272 C88F 2FD6
* kwolf/tags/for-upstream:
block/file-*: *_parse_filename() and colons
block: Fix backing paths for filenames with colons
block: Tweak error message related to qemu-img amend
qemu-img: Fix leakage of options on error
qemu-img: copy *key-secret opts when opening newly created files
qemu-img: introduce --target-image-opts for 'convert' command
qemu-img: fix --image-opts usage with dd command
qemu-img: add support for --object with 'dd' command
qemu-img: Fix documentation of convert
qcow2: remove extra local_error variable
mirror: Drop permissions on s->target on completion
nvme: Add support for Controller Memory Buffers
iotests: 147: Don't test inet6 if not available
qemu-iotests: Test streaming with missing job ID
stream: fix crash in stream_start() when block_job_create() fails
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
This fixes an assertion failure that was triggered by qemu-iotests 129
on some CI host, while the same test case didn't seem to fail on other
hosts.
Essentially the problem is that the blk_unref(s->target) in
mirror_exit() doesn't necessarily mean that the BlockBackend goes away
immediately. It is possible that the job completion was triggered nested
in mirror_drain(), which looks like this:
BlockBackend *target = s->target;
blk_ref(target);
blk_drain(target);
blk_unref(target);
In this case, the write permissions for s->target are retained until
after blk_drain(), which makes removing mirror_top_bs fail for the
active commit case (can't have a writable backing file in the chain
without the filter driver).
Explicitly dropping the permissions first means that the additional
reference doesn't hurt and the job can complete successfully even if
called from the nested blk_drain().
Cc: qemu-stable@nongnu.org
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Outside blockjob.c, block_job_unref is only used when a block job fails
to start, and block_job_ref is not used at all. The reference counting
thus is pretty well hidden. Introduce a separate function to be used
by block jobs; because block_job_ref and block_job_unref now become
static, move them earlier in blockjob.c.
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Message-id: 20170508141310.8674-4-pbonzini@redhat.com
Signed-off-by: Jeff Cody <jcody@redhat.com>
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>
It should be moved to the same context as source, before inserting to the
graph.
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
If @bs does not have any parents, the only reference to @mirror_top_bs
will be held by the BlockJob object after the bdrv_unref() following
block_job_create(). However, if block_job_create() fails, this reference
will not exist and @mirror_top_bs will have been deleted when we
goto fail.
The issue comes back at all later entries to the fail label: We delete
the BlockJob object before rolling back our changes to the node graph.
This means that we will delete @mirror_top_bs in the process.
All in all, whenever @bs does not have any parents and we go down the
fail path we will dereference @mirror_top_bs after it has been deleted.
Fix this by invoking bdrv_unref() only when block_job_create() was
successful and by bdrv_ref()'ing @mirror_top_bs in the fail path before
deleting the BlockJob object. Finally, bdrv_unref() it at the end of the
fail path after we actually no longer need it.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
block/trace-events lists the parameters for mirror_yield
consistently with other mirror events (cnt just after s, like in
mirror_before_sleep; in_flight last, like in mirror_yield_in_flight).
But the callers were passing parameters in the wrong order, leading
to poor trace messages, including type truncation when there are
more than 4G dirty sectors involved. Broken since its introduction
in commit bd48bde.
While touching this, ensure that all callers use the same type
(uint64_t) for cnt, as a later patch will enable the compiler to do
stricter type-checking.
Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
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>
We want query-block to return the right filename, even if a mirror job
put a bdrv_mirror_top on top of the actual image format driver. Let
bdrv_mirror_top.bdrv_refresh_filename get the filename from its backing
file.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
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>
mirror_top_bs must be removed from the graph again when creating the
dirty bitmap fails.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
mirror_top_bs takes write permissions on its backing file, which can
make it impossible to attach that backing file node to another parent.
However, this is exactly what needs to be done in order to remove
mirror_top_bs from the backing chain. So give up the write permission
first.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
The 'replaces' option of drive-mirror can be used to mirror a Quorum
node to a new image and then let the target image replace one of the
Quorum children. In order for this graph modification to succeed, the
mirror job needs to lift its restrictions on the target node first
before actually replacing the child.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
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>
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>
Management tools need to be able to know about every node in the graph
and need a way to address them. Changing the graph structure was okay
because libvirt doesn't really manage the node level yet, but future
libvirt versions need to deal with both new and old version of qemu.
This new option to blockdev-commit allows the client to set a node-name
for the automatically inserted filter driver, and at the same time
serves as a witness for a future libvirt that this version of qemu does
automatically insert a filter driver.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Management tools need to be able to know about every node in the graph
and need a way to address them. Changing the graph structure was okay
because libvirt doesn't really manage the node level yet, but future
libvirt versions need to deal with both new and old version of qemu.
This new option to blockdev-mirror allows the client to set a node-name
for the automatically inserted filter driver, and at the same time
serves as a witness for a future libvirt that this version of qemu does
automatically insert a filter driver.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
The mirror block job is mainly used for two different scenarios:
Mirroring to an otherwise unused, independent target node, or for active
commit where the target node is part of the backing chain of the source.
Similarly to the commit block job patch, we need to insert a new filter
node to keep the permissions correct during active commit.
Note that one change this implies is that job->blk points to
mirror_top_bs as its root now, and mirror_top_bs (rather than the actual
source node) contains the bs->job pointer. This requires qemu-img commit
to get the job by name now rather than just taking bs->job.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
Acked-by: Max Reitz <mreitz@redhat.com>
Block jobs don't actually do I/O through the the reference they create
with block_job_add_bdrv(), but they might want to use the permisssion
system to express what the block job does to intermediate nodes. This
adds permissions to block_job_add_bdrv() to provide the means to request
permissions.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
This functions creates a BlockBackend internally, so the block jobs need
to tell it what they want to do with the BB.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
