This patch changes block_job_pause to increase the pause counter and
block_job_resume to decrease it.
The counter will allow calling block_job_pause/block_job_resume
unconditionally on a job when we need to suspend the IO temporarily.
From now on, each block_job_resume must be paired with a block_job_pause
to keep the counter balanced.
The user pause from QMP or HMP will only trigger block_job_pause once
until it's resumed, this is achieved by adding a user_paused flag in
BlockJob.
One occurrence of block_job_resume in mirror_complete is replaced with
block_job_enter which does what is necessary.
In block_job_cancel, the cancel flag is good enough to instruct
coroutines to quit loop, so use block_job_enter to replace the unpaired
block_job_resume.
Upon block job IO error, user is notified about the entering to the
pause state, so this pause belongs to user pause, set the flag
accordingly and expect a matching QMP resume.
[Extended doc comments as suggested by Paolo Bonzini
<pbonzini@redhat.com>.
--Stefan]
Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 1428069921-2957-2-git-send-email-famz@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Now that blockjobs use AioContext they are safe for use with dataplane.
Unblock them!
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 1413889440-32577-12-git-send-email-stefanha@redhat.com
Block jobs will run in the BlockDriverState's AioContext, which may not
always be the QEMU main loop.
There are some block layer APIs that are either not thread-safe or risk
lock ordering problems. This includes bdrv_unref(), bdrv_close(), and
anything that calls bdrv_drain_all().
The block_job_defer_to_main_loop() API allows a block job to schedule a
function to run in the main loop with the BlockDriverState AioContext
held.
This function will be used to perform cleanup and backing chain
manipulations in block jobs.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 1413889440-32577-6-git-send-email-stefanha@redhat.com
When a block job signals readiness, this is currently reported only
through QMP. If qemu wants to use block jobs for internal tasks, there
needs to be another way to correctly detect when a block job may be
completed.
For this reason, introduce a bool "ready" which is set when the block
job may be completed.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-id: 1414159063-25977-6-git-send-email-mreitz@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Implement block_job_complete_sync() by doing the exact same thing as
block_job_cancel_sync() does, only with calling block_job_complete()
instead of block_job_cancel().
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 1414159063-25977-5-git-send-email-mreitz@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
I'll use it with block backends shortly, and the name is going to fit
badly there. It's a block layer thing anyway, not just a block driver
thing.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
device_name[] can become non-empty only in bdrv_new_root() and
bdrv_move_feature_fields(). The latter is used only to undo damage
done by bdrv_swap(). The former is called only by blk_new_with_bs().
Therefore, when a BlockDriverState's device_name[] is non-empty, then
it's been created with a BlockBackend, and vice versa. Furthermore,
blk_new_with_bs() keeps the two names equal.
Therefore, device_name[] is redundant. Eliminate it.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
block_job_sleep_ns is the only user. Since we are moving towards
AioContext aware code, it's better to use the explicit version and drop
the old one.
Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Benoît Canet <benoit.canet@nodalink.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Commit 5a2d2cb screwed up the the value of members device and action,
breaking tests/qemu-iotests/041.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Tested-By: Benoit Canet <benoit@irqsave.net>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Commit bcada37 dropped the (up to now undocumented) members type, len,
offset, speed, breaking tests/qemu-iotests/040 and 041.
Restore and document them. This fixes 040, and partially fixes 041.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Tested-By: Benoit Canet <benoit@irqsave.net>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This will unset busy flag and put coroutine to sleep, can be used to
wait for QMP complete/cancel.
Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Since BLOCK_JOB_COMPLETED, BLOCK_JOB_CANCELLED, BLOCK_JOB_READY are
related, convert them in one patch. The block_job_event_* functions
are used to keep encapsulation of BlockJob structure.
Signed-off-by: Wenchao Xia <wenchaoqemu@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
In order to let event defines use existing types later, instead of
redefine new ones, some old type defines for spice and vnc are changed,
and BlockErrorAction is moved from block.h to qapi schema. Note that
BlockErrorAction is not merged with BlockdevOnError.
At this point, VncInfo is not made a child of VncBasicInfo, because
VncBasicInfo has mandatory fields where VncInfo makes them optional.
Signed-off-by: Wenchao Xia <wenchaoqemu@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
It makes no sense to check for "any" blocker on bs, we are here only
because of the mechanical conversion from in_use to op_blockers. Remove
it now, and let the callers check specific operation types. Backup and
mirror already have it, add checker to stream and commit.
Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
This drops BlockDriverState.in_use with op_blockers:
- Call bdrv_op_block_all in place of bdrv_set_in_use(bs, 1).
- Call bdrv_op_unblock_all in place of bdrv_set_in_use(bs, 0).
- Check bdrv_op_is_blocked() in place of bdrv_in_use(bs).
The specific types are used, e.g. in place of starting block backup,
bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_BACKUP, ...).
There is one exception in block_job_create, where
bdrv_op_blocker_is_empty() is used, because we don't know the operation
type here. This doesn't matter because in a few commits away we will drop
the check and move it to callers that _do_ know the type.
- Check bdrv_op_blocker_is_empty() in place of assert(!bs->in_use).
Note: there is only bdrv_op_block_all and bdrv_op_unblock_all callers at
this moment. So although the checks are specific to op types, this
changes can still be seen as identical logic with previously with
in_use. The difference is error message are improved because of blocker
error info.
Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
The former is only used twice, the latter is used over 30 times, and
has a nicer error message.
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Cole Robinson <crobinso@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
error_is_set(&var) is the same as var != NULL, but it takes
whole-program analysis to figure that out. Unnecessarily hard for
optimizers, static checkers, and human readers. Dumb it down to
obvious.
Gets rid of several dozen Coverity false positives.
Note that the obvious form is already used in many places.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Switch the string to enum type BlockJobType in BlockJobDriver.
Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We will use BlockJobType as the enum type name of block jobs in QAPI,
rename current BlockJobType to BlockJobDriver, which will eventually
become a set of operations, similar to block drivers.
Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Block jobs used drive_get_ref(drive_get_by_blockdev(bs)) to avoid BDS
being deleted. Now we have BDS reference count, and block jobs don't
care about dinfo, so replace them to get cleaner code. It is also the
safe way when BDS has no drive info.
Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Convert block_job_sleep_ns and co_sleep_ns to use the new timer
API.
Signed-off-by: Alex Bligh <alex@alex.org.uk>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Even for jobs that need to be manually completed, management may want
to take care itself of the completion, not requiring the user to issue
a command to terminate the job. In this case we want to avoid that
they poll us continuously, waiting for completion to become available.
Thus, add a new event that signals the phase switch and the availability
of the block-job-complete command.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
While streaming can be dropped as soon as it progressed through the whole
image, mirroring needs to be completed manually for two reasons: 1) so that
management knows exactly when the VM switches to the target; 2) because
for other use cases such as replication, we may leave the operation running
for the whole life of the virtual machine.
Add a new block job command that manually completes background operations.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The following behaviors are possible:
'report': The behavior is the same as in 1.1. An I/O error,
respectively during a read or a write, will complete the job immediately
with an error code.
'ignore': An I/O error, respectively during a read or a write, will be
ignored. For streaming, the job will complete with an error and the
backing file will be left in place. For mirroring, the sector will be
marked again as dirty and re-examined later.
'stop': The job will be paused and the job iostatus will be set to
failed or nospace, while the VM will keep running. This can only be
specified if the block device has rerror=stop and werror=stop or enospc.
'enospc': Behaves as 'stop' for ENOSPC errors, 'report' for others.
In all cases, even for 'report', the I/O error is reported as a QMP
event BLOCK_JOB_ERROR, with the same arguments as BLOCK_IO_ERROR.
It is possible that while stopping the VM a BLOCK_IO_ERROR event will be
reported and will clobber the event from BLOCK_JOB_ERROR, or vice versa.
This is not really avoidable since stopping the VM completes all pending
I/O requests. In fact, it is already possible now that a series of
BLOCK_IO_ERROR events are reported with rerror=stop, because vm_stop
calls bdrv_drain_all and this can generate further errors.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Job pausing reuses the existing support for cancellable sleeps. A pause
happens at the next sleeping point and lasts until the coroutine is
re-entered explicitly. Cancellation was already doing a forced resume,
so implement it explicitly in terms of resume.
Paused jobs cannot be canceled without first resuming them. This ensures
that I/O errors are never missed by management.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Because pausing a job is asynchronous, we need to know whether it has
completed. This is described by the "busy" field of BlockJob; copy it
to BlockJobInfo.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Extract it out of the implementation of info block-jobs.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
