Commit Graph

173 Commits

Author SHA1 Message Date
Kevin Wolf 89bd030533 block: Really pause block jobs on drain
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>
2018-06-18 15:03:25 +02:00
Kevin Wolf 9f6bb4c004 blockjob: Remove BlockJob.driver
BlockJob.driver is redundant with Job.driver and only used in very few
places any more. Remove it.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-05-23 14:30:51 +02:00
Kevin Wolf 30a5c887bf job: Move progress fields to Job
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>
2018-05-23 14:30:51 +02:00
Kevin Wolf 2e1795b581 job: Add job_transition_to_ready()
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>
2018-05-23 14:30:51 +02:00
Kevin Wolf df956ae201 job: Add job_is_ready()
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>
2018-05-23 14:30:51 +02:00
Kevin Wolf 5f9a6a08e8 job: Add job_dismiss()
This moves block_job_dismiss() to the Job layer.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2018-05-23 14:30:51 +02:00
Kevin Wolf 198c49cc8d job: Add job_yield()
This moves block_job_yield() to the Job layer.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2018-05-23 14:30:51 +02:00
Kevin Wolf 3d70ff53b6 job: Move completion and cancellation to Job
This moves the top-level job completion and cancellation functions from
BlockJob to Job.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-05-23 14:30:51 +02:00
Kevin Wolf 7eaa8fb57d job: Move transactions to Job
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>
2018-05-23 14:30:51 +02:00
Kevin Wolf 62c9e4162a job: Switch transactions to JobTxn
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>
2018-05-23 14:30:50 +02:00
Kevin Wolf 6a74c075ac job: Move job_finish_sync() to Job
block_job_finish_sync() doesn't contain anything block job specific any
more, so it can be moved to Job.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2018-05-23 14:30:50 +02:00
Kevin Wolf 3453d97243 job: Move .complete callback to Job
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>
2018-05-23 14:30:50 +02:00
Kevin Wolf b69f777dd9 job: Add job_drain()
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>
2018-05-23 14:30:50 +02:00
Kevin Wolf 004e95df98 job: Convert block_job_cancel_async() to Job
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>
2018-05-23 14:30:50 +02:00
Kevin Wolf 4ad351819b job: Move single job finalisation to Job
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>
2018-05-23 14:30:50 +02:00
Kevin Wolf 139a9f020d job: Add job_event_*()
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>
2018-05-23 14:30:50 +02:00
Kevin Wolf 5d4f376998 blockjob: Split block_job_event_pending()
block_job_event_pending() doesn't only send a QMP event, but it also
transitions to the PENDING state. Split the function so that we get one
part only sending the event (like other block_job_event_* functions) and
another part that does the state transition.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2018-05-23 14:30:50 +02:00
Kevin Wolf bb02b65c7d job: Move BlockJobCreateFlags to Job
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>
2018-05-23 14:30:50 +02:00
Kevin Wolf dbe5e6c1f7 job: Replace BlockJob.completed with job_is_completed()
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>
2018-05-23 14:30:50 +02:00
Kevin Wolf b15de82867 job: Move pause/resume functions to Job
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>
2018-05-23 14:30:50 +02:00
Kevin Wolf 5d43e86e11 job: Add job_sleep_ns()
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>
2018-05-23 14:30:50 +02:00
Kevin Wolf da01ff7f38 job: Move coroutine and related code to Job
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>
2018-05-23 14:30:50 +02:00
Kevin Wolf 1908a5590c job: Move defer_to_main_loop to Job
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>
2018-05-23 14:30:50 +02:00
Kevin Wolf 08be6fe26f job: Add Job.aio_context
When block jobs need an AioContext, they just take it from their main
block node. Generic jobs don't have a main block node, so we need to
assign them an AioContext explicitly.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
2018-05-23 14:30:49 +02:00
Kevin Wolf daa7f2f946 job: Move cancelled to Job
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>
2018-05-23 14:30:49 +02:00
Kevin Wolf 80fa2c756b job: Add reference counting
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>
2018-05-23 14:30:49 +02:00
Kevin Wolf a50c2ab858 job: Move state transitions to Job
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>
2018-05-23 14:30:49 +02:00
Kevin Wolf e7c1d78bbd job: Maintain a list of all jobs
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>
2018-05-23 14:30:49 +02:00
Kevin Wolf fd61a701f1 job: Add job_delete()
This moves freeing the Job object and its fields from block_job_unref()
to job_delete().

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
2018-05-23 14:30:49 +02:00
Kevin Wolf 252291eaea job: Add JobDriver.job_type
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>
2018-05-23 14:30:49 +02:00
Kevin Wolf 8e4c87000f job: Rename BlockJobType into JobType
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>
2018-05-23 14:30:49 +02:00
Kevin Wolf 33e9e9bd62 job: Create Job, JobDriver and job_create()
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>
2018-05-23 14:30:49 +02:00
Stefan Hajnoczi 4c7e813ce9 blockjob: do not cancel timer in resume
Currently the timer is cancelled and the block job is entered by
block_job_resume().  This behavior causes drain to run extra blockjob
iterations when the job was sleeping due to the ratelimit.

This patch leaves the job asleep when block_job_resume() is called.
Jobs can still be forcibly woken up using block_job_enter(), which is
used to cancel jobs.

After this patch drain no longer runs extra blockjob iterations.  This
is the expected behavior that qemu-iotests 185 used to rely on.  We
temporarily changed the 185 test output to make it pass for the QEMU
2.12 release but now it's time to address this issue.

Cc: QingFeng Hao <haoqf@linux.vnet.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: QingFeng Hao <haoqf@linux.vnet.ibm.com>
Message-id: 20180508135436.30140-3-stefanha@redhat.com
Reviewed-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Jeff Cody <jcody@redhat.com>
2018-05-16 13:37:33 -04:00
Kevin Wolf bd21935b50 blockjob: Add block_job_driver()
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>
2018-05-15 16:11:50 +02:00
Kevin Wolf dee81d5111 blockjob: Introduce block_job_ratelimit_get_delay()
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>
2018-05-15 16:11:50 +02:00
Kevin Wolf 18bb69287e blockjob: Implement block_job_set_speed() centrally
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>
2018-05-15 16:11:50 +02:00
Kevin Wolf 05df8a6a2b blockjob: Wrappers for progress counter access
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>
2018-05-15 16:11:49 +02:00
Kevin Wolf 37aa19b63c blockjob: Fix assertion in block_job_finalize()
Every job gets a non-NULL job->txn on creation, but it doesn't
necessarily keep it until it is decommissioned: Finalising a job removes
it from its transaction. Therefore, calling 'blockdev-job-finalize' a
second time on an already concluded job causes an assertion failure.

Remove job->txn from the assertion in block_job_finalize() to fix this.
block_job_do_finalize() still has the same assertion, but if a job is
already removed from its transaction, block_job_apply_verb() will
already error out before we run into that assertion.

Cc: qemu-stable@nongnu.org
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>
2018-05-15 16:11:49 +02:00
John Snow ab9ba61455 blockjob: expose error string via query
When we've reached the concluded state, we need to expose the error
state if applicable. Add the new field.

This should be sufficient for determining if a job completed
successfully or not after concluding; if we want to discriminate
based on how it failed more mechanically, we can always add an
explicit return code enumeration later.

I didn't bother to make it only show up if we are in the concluded
state; I don't think it's necessary.

Cc: qemu-stable@nongnu.org
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-05-15 16:11:41 +02:00
Stefan Hajnoczi 23d702d898 blockjob: drop block_job_pause/resume_all()
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>
2018-05-10 10:41:12 +01:00
Marc-André Lureau 604343ced7 blockjob: use qapi enum helpers
QAPI generator provide #define helpers for looking up enum string.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 20180327153011.29569-1-marcandre.lureau@redhat.com
Signed-off-by: Jeff Cody <jcody@redhat.com>
2018-04-03 09:56:55 -04:00
Marc-André Lureau a865cebb82 blockjob: leak fix, remove from txn when failing early
This fixes leaks found by ASAN such as:
  GTESTER tests/test-blockjob
=================================================================
==31442==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 24 byte(s) in 1 object(s) allocated from:
    #0 0x7f88483cba38 in __interceptor_calloc (/lib64/libasan.so.4+0xdea38)
    #1 0x7f8845e1bd77 in g_malloc0 ../glib/gmem.c:129
    #2 0x7f8845e1c04b in g_malloc0_n ../glib/gmem.c:360
    #3 0x5584d2732498 in block_job_txn_new /home/elmarco/src/qemu/blockjob.c:172
    #4 0x5584d2739b28 in block_job_create /home/elmarco/src/qemu/blockjob.c:973
    #5 0x5584d270ae31 in mk_job /home/elmarco/src/qemu/tests/test-blockjob.c:34
    #6 0x5584d270b1c1 in do_test_id /home/elmarco/src/qemu/tests/test-blockjob.c:57
    #7 0x5584d270b65c in test_job_ids /home/elmarco/src/qemu/tests/test-blockjob.c:118
    #8 0x7f8845e40b69 in test_case_run ../glib/gtestutils.c:2255
    #9 0x7f8845e40f29 in g_test_run_suite_internal ../glib/gtestutils.c:2339
    #10 0x7f8845e40fd2 in g_test_run_suite_internal ../glib/gtestutils.c:2351
    #11 0x7f8845e411e9 in g_test_run_suite ../glib/gtestutils.c:2426
    #12 0x7f8845e3fe72 in g_test_run ../glib/gtestutils.c:1692
    #13 0x5584d270d6e2 in main /home/elmarco/src/qemu/tests/test-blockjob.c:377
    #14 0x7f8843641f29 in __libc_start_main (/lib64/libc.so.6+0x20f29)

Add an assert to make sure that the job doesn't have associated txn before free().

[Jeff Cody: N.B., used updated patch provided by John Snow]

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Jeff Cody <jcody@redhat.com>
2018-04-03 09:56:55 -04:00
Liang Li b76e4458b1 block/mirror: change the semantic of 'force' of block-job-cancel
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>
2018-03-19 12:01:39 +01:00
John Snow b40dacdc7c blockjobs: Expose manual property
Expose the "manual" property via QAPI for the backup-related jobs.
As of this commit, this allows the management API to request the
"concluded" and "dismiss" semantics for backup jobs.

Signed-off-by: John Snow <jsnow@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-03-19 12:01:24 +01:00
John Snow 11b61fbc0d blockjobs: add block-job-finalize
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>
2018-03-19 12:01:24 +01:00
John Snow 5f241594c4 blockjobs: add PENDING status and event
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>
2018-03-19 12:01:24 +01:00
John Snow e8af5686ff blockjobs: add waiting status
For jobs that are stuck waiting on others in a transaction, it would
be nice to know that they are no longer "running" in that sense, but
instead are waiting on other jobs in the transaction.

Jobs that are "waiting" in this sense cannot be meaningfully altered
any longer as they have left their running loop. The only meaningful
user verb for jobs in this state is "cancel," which will cancel the
whole transaction, too.

Transitions:
Running -> Waiting:   Normal transition.
Ready   -> Waiting:   Normal transition.
Waiting -> Aborting:  Transactional cancellation.
Waiting -> Concluded: Normal transition.

Removed Transitions:
Running -> Concluded: Jobs must go to WAITING first.
Ready   -> Concluded: Jobs must go to WAITING first.

Verbs:
Cancel: Can be applied to WAITING jobs.

             +---------+
             |UNDEFINED|
             +--+------+
                |
             +--v----+
   +---------+CREATED+-----------------+
   |         +--+----+                 |
   |            |                      |
   |         +--v----+     +------+    |
   +---------+RUNNING<----->PAUSED|    |
   |         +--+-+--+     +------+    |
   |            | |                    |
   |            | +------------------+ |
   |            |                    | |
   |         +--v--+       +-------+ | |
   +---------+READY<------->STANDBY| | |
   |         +--+--+       +-------+ | |
   |            |                    | |
   |         +--v----+               | |
   +---------+WAITING<---------------+ |
   |         +--+----+                 |
   |            |                      |
+--v-----+   +--v------+               |
|ABORTING+--->CONCLUDED|               |
+--------+   +--+------+               |
                |                      |
             +--v-+                    |
             |NULL<--------------------+
             +----+

Signed-off-by: John Snow <jsnow@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-03-19 12:01:24 +01:00
John Snow 2da4617a54 blockjobs: add prepare callback
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>
2018-03-19 12:01:24 +01:00
John Snow efe4d4b7b2 blockjobs: add block_job_txn_apply function
Simply apply a function transaction-wide.
A few more uses of this in forthcoming patches.

Signed-off-by: John Snow <jsnow@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-03-19 12:01:24 +01:00
John Snow 43628d9336 blockjobs: add commit, abort, clean helpers
The completed_single function is getting a little mucked up with
checking to see which callbacks exist, so let's factor them out.

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>
2018-03-19 12:01:24 +01:00