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>
Instead of having a 'bool ready' in BlockJob, add a function that
derives its value from the job status.
At the same time, this fixes the behaviour to match what the QAPI
documentation promises for query-block-job: 'true if the job may be
completed'. When the ready flag was introduced in commit ef6dbf1e46,
the flag never had to be reset to match the description because after
being ready, the jobs would immediately complete and disappear.
Job transactions and manual job finalisation were introduced only later.
With these changes, jobs may stay around even after having completed
(and they are not ready to be completed a second time), however their
patches forgot to reset the ready flag.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
This moves the logic that implements job transactions from BlockJob to
Job.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
This doesn't actually move any transaction code to Job yet, but it
renames the type for transactions from BlockJobTxn to JobTxn and makes
them contain Jobs rather than BlockJobs
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>
Go through the Job layer in order to send QMP events. For the moment,
these functions only call a notifier in the BlockJob layer that sends
the existing commands.
This uses notifiers rather than JobDriver callbacks because internal
users of jobs won't receive QMP events, but might still be interested
in getting notified for the events.
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>
Since we introduced an explicit status to block job, BlockJob.completed
is redundant because it can be derived from the status. Remove the field
from BlockJob and add a function to derive it from the status at the Job
level.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@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 BlockJob.status and the closely related functions
(block_)job_state_transition() and (block_)job_apply_verb to Job. The
two QAPI enums are renamed to JobStatus and JobVerb.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
This moves the job list from BlockJob to Job. Now we can check for
duplicate IDs in 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>
When we call addIOThread, the epollfd created in aio_context_setup,
but not close it in the process of delIOThread, so the epollfd will leak.
Reorder the code in aio_epoll_disable and reuse it.
Signed-off-by: Jie Wang <wangjie88@huawei.com>
Message-Id: <1526517763-11108-1-git-send-email-wangjie88@huawei.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
[Mention change to aio_epoll_disable in commit message. - Fam]
Signed-off-by: Fam Zheng <famz@redhat.com>
Add BDRV_REQ_WRITE_UNCHANGED to the list of flags honored during pwrite
and pwrite_zeroes, and also add a note on when you absolutely need to
support it.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20180502140359.18222-1-mreitz@redhat.com
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
This flag signifies that a write request will not change the visible
disk content. With this flag set, it is sufficient to have the
BLK_PERM_WRITE_UNCHANGED permission instead of BLK_PERM_WRITE.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20180421132929.21610-4-mreitz@redhat.com
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Currently we never actually check whether the WRITE_UNCHANGED
permission has been taken for unchanging writes. But the one check that
is commented out checks both WRITE and WRITE_UNCHANGED; and considering
that WRITE_UNCHANGED is already documented as being weaker than WRITE,
we should probably explicitly document WRITE to include WRITE_UNCHANGED.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20180421132929.21610-3-mreitz@redhat.com
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
The backup block job directly accesses the driver field in BlockJob. Add
a wrapper for getting it.
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 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>
We have too many driver callback interfaces; simplify the mess
somewhat by merging the flags parameter of .bdrv_co_writev_flags()
into .bdrv_co_writev(). Note that as long as a driver doesn't set
.supported_write_flags, the flags argument will be 0 and behavior is
identical. Also note that the public function bdrv_co_writev() still
lacks a flags argument; so the driver signature is thus intentionally
slightly different. But that's not the end of the world, nor the first
time that the driver interface differs slightly from the public
interface.
Ideally, we should be rewriting all of these drivers to use modern
byte-based interfaces. But that's a more invasive patch to write
and audit, compared to the simplification done here.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We are gradually moving away from sector-based interfaces, towards
byte-based. Now that all drivers with aio callbacks are using the
byte-based interfaces, we can remove the sector-based versions.
Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We are gradually moving away from sector-based interfaces, towards
byte-based. Make the change for the last few sector-based callbacks
in the file-win32 driver.
Note that the driver was already using byte-based calls for
performing actual I/O, so this just gets rid of a round trip
of scaling; however, as I don't know if Windows is tolerant of
non-sector AIO operations, I went with the conservative approach
of modifying .bdrv_refresh_limits to override the block layer
defaults back to the pre-patch value of 512.
Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We are gradually moving away from sector-based interfaces, towards
byte-based. Add new sector-based aio callbacks for read and write,
to match the fact that bdrv_aio_pdiscard is already byte-based.
Ideally, drivers should be converted to use coroutine callbacks
rather than aio; but that is not quite as trivial (and if we were
to do that conversion, the null-aio driver would disappear), so for
the short term, converting the signature but keeping things with
aio is easier. However, we CAN declare that a driver that uses
the byte-based aio interfaces now defaults to byte-based
operations, and must explicitly provide a refresh_limits override
to stick with larger alignments (making the alignment issues more
obvious directly in the drivers touched in the next few patches).
Once all drivers are converted, the sector-based aio callbacks will
be removed; in the meantime, a FIXME comment is added due to a
slight inefficiency that will be touched up as part of that later
cleanup.
Simplify some instances of 'bs->drv' into 'drv' while touching this,
since the local variable already exists to reduce typing.
Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Commit 8119334918 ("block: Don't
block_job_pause_all() in bdrv_drain_all()") removed the only callers of
block_job_pause/resume_all().
Pausing and resuming now happens in child_job_drained_begin/end() so
it's no longer necessary to globally pause/resume jobs.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20180424085240.5798-1-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Clarify that:
- for protocols the brdv_file_open function is used instead
of bdrv_open;
- when protocol_name is set, a driver should expect
to be given only a filename and no other options.
Signed-off-by: Fabiano Rosas <farosas@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Introduce latency histogram statics for block devices.
For each accounted operation type, the latency region [0, +inf) is
divided into subregions by several points. Then, calculate
hits for each subregion.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20180309165212.97144-2-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Eric Blake <eblake@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>
Instead of automatically transitioning from PENDING to CONCLUDED, gate
the .prepare() and .commit() phases behind an explicit acknowledgement
provided by the QMP monitor if auto_finalize = false has been requested.
This allows us to perform graph changes in prepare and/or commit so that
graph changes do not occur autonomously without knowledge of the
controlling management layer.
Transactions that have reached the "PENDING" state together can all be
moved to invoke their finalization methods by issuing block_job_finalize
to any one job in the transaction.
Jobs in a transaction with mixed job->auto_finalize settings will all
remain stuck in the "PENDING" state, as if the entire transaction was
specified with auto_finalize = false. Jobs that specified
auto_finalize = true, however, will still not emit the PENDING event.
Signed-off-by: John Snow <jsnow@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
For jobs utilizing the new manual workflow, we intend to prohibit
them from modifying the block graph until the management layer provides
an explicit ACK via block-job-finalize to move the process forward.
To distinguish this runstate from "ready" or "waiting," we add a new
"pending" event and status.
For now, the transition from PENDING to CONCLUDED/ABORTING is automatic,
but a future commit will add the explicit block-job-finalize step.
Transitions:
Waiting -> Pending: Normal transition.
Pending -> Concluded: Normal transition.
Pending -> Aborting: Late transactional failures and cancellations.
Removed Transitions:
Waiting -> Concluded: Jobs must go to PENDING first.
Verbs:
Cancel: Can be applied to a pending job.
+---------+
|UNDEFINED|
+--+------+
|
+--v----+
+---------+CREATED+-----------------+
| +--+----+ |
| | |
| +--+----+ +------+ |
+---------+RUNNING<----->PAUSED| |
| +--+-+--+ +------+ |
| | | |
| | +------------------+ |
| | | |
| +--v--+ +-------+ | |
+---------+READY<------->STANDBY| | |
| +--+--+ +-------+ | |
| | | |
| +--v----+ | |
+---------+WAITING<---------------+ |
| +--+----+ |
| | |
| +--v----+ |
+---------+PENDING| |
| +--+----+ |
| | |
+--v-----+ +--v------+ |
|ABORTING+--->CONCLUDED| |
+--------+ +--+------+ |
| |
+--v-+ |
|NULL<--------------------+
+----+
Signed-off-by: John Snow <jsnow@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Some jobs upon finalization may need to perform some work that can
still fail. If these jobs are part of a transaction, it's important
that these callbacks fail the entire transaction.
We allow for a new callback in addition to commit/abort/clean that
allows us the opportunity to have fairly late-breaking failures
in the transactional process.
The expected flow is:
- All jobs in a transaction converge to the PENDING state,
added in a forthcoming commit.
- Upon being finalized, either automatically or explicitly
by the user, jobs prepare to complete.
- If any job fails preparation, all jobs call .abort.
- Otherwise, they succeed and call .commit.
Signed-off-by: John Snow <jsnow@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
For jobs that have reached their CONCLUDED state, prior to having their
last reference put down (meaning jobs that have completed successfully,
unsuccessfully, or have been canceled), allow the user to dismiss the
job's lingering status report via block-job-dismiss.
This gives management APIs the chance to conclusively determine if a job
failed or succeeded, even if the event broadcast was missed.
Note: block_job_do_dismiss and block_job_decommission happen to do
exactly the same thing, but they're called from different semantic
contexts, so both aliases are kept to improve readability.
Note 2: Don't worry about the 0x04 flag definition for AUTO_DISMISS, she
has a friend coming in a future patch to fill the hole where 0x02 is.
Verbs:
Dismiss: operates on CONCLUDED jobs only.
Signed-off-by: John Snow <jsnow@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Which commands ("verbs") are appropriate for jobs in which state is
also somewhat burdensome to keep track of.
As of this commit, it looks rather useless, but begins to look more
interesting the more states we add to the STM table.
A recurring theme is that no verb will apply to an 'undefined' job.
Further, it's not presently possible to restrict the "pause" or "resume"
verbs any more than they are in this commit because of the asynchronous
nature of how jobs enter the PAUSED state; justifications for some
seemingly erroneous applications are given below.
=====
Verbs
=====
Cancel: Any state except undefined.
Pause: Any state except undefined;
'created': Requests that the job pauses as it starts.
'running': Normal usage. (PAUSED)
'paused': The job may be paused for internal reasons,
but the user may wish to force an indefinite
user-pause, so this is allowed.
'ready': Normal usage. (STANDBY)
'standby': Same logic as above.
Resume: Any state except undefined;
'created': Will lift a user's pause-on-start request.
'running': Will lift a pause request before it takes effect.
'paused': Normal usage.
'ready': Will lift a pause request before it takes effect.
'standby': Normal usage.
Set-speed: Any state except undefined, though ready may not be meaningful.
Complete: Only a 'ready' job may accept a complete request.
=======
Changes
=======
(1)
To facilitate "nice" error checking, all five major block-job verb
interfaces in blockjob.c now support an errp parameter:
- block_job_user_cancel is added as a new interface.
- block_job_user_pause gains an errp paramter
- block_job_user_resume gains an errp parameter
- block_job_set_speed already had an errp parameter.
- block_job_complete already had an errp parameter.
(2)
block-job-pause and block-job-resume will no longer no-op when trying
to pause an already paused job, or trying to resume a job that isn't
paused. These functions will now report that they did not perform the
action requested because it was not possible.
iotests have been adjusted to address this new behavior.
(3)
block-job-complete doesn't worry about checking !block_job_started,
because the permission table guards against this.
(4)
test-bdrv-drain's job implementation needs to announce that it is
'ready' now, in order to be completed.
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We're about to add several new states, and booleans are becoming
unwieldly and difficult to reason about. It would help to have a
more explicit bookkeeping of the state of blockjobs. To this end,
add a new "status" field and add our existing states in a redundant
manner alongside the bools they are replacing:
UNDEFINED: Placeholder, default state. Not currently visible to QMP
unless changes occur in the future to allow creating jobs
without starting them via QMP.
CREATED: replaces !!job->co && paused && !busy
RUNNING: replaces effectively (!paused && busy)
PAUSED: Nearly redundant with info->paused, which shows pause_count.
This reports the actual status of the job, which almost always
matches the paused request status. It differs in that it is
strictly only true when the job has actually gone dormant.
READY: replaces job->ready.
STANDBY: Paused, but job->ready is true.
New state additions in coming commits will not be quite so redundant:
WAITING: Waiting on transaction. This job has finished all the work
it can until the transaction converges, fails, or is canceled.
PENDING: Pending authorization from user. This job has finished all the
work it can until the job or transaction is finalized via
block_job_finalize. This implies the transaction has converged
and left the WAITING phase.
ABORTING: Job has encountered an error condition and is in the process
of aborting.
CONCLUDED: Job has ceased all operations and has a return code available
for query and may be dismissed via block_job_dismiss.
NULL: Job has been dismissed and (should) be destroyed. Should never
be visible to QMP.
Some of these states appear somewhat superfluous, but it helps define the
expected flow of a job; so some of the states wind up being synchronous
empty transitions. Importantly, jobs can be in only one of these states
at any given time, which helps code and external users alike reason about
the current condition of a job unambiguously.
Signed-off-by: John Snow <jsnow@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Kevin Wolf
Jie Wang
Max Reitz
Eric Blake
Stefan Hajnoczi
Fabiano Rosas
Vladimir Sementsov-Ogievskiy
Liang Li
John Snow