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2018-04-03blockjob: use qapi enum helpersMarc-André Lureau1-9/+5
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>
2018-04-03blockjob: leak fix, remove from txn when failing earlyMarc-André Lureau1-2/+12
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>
2018-03-19block/mirror: change the semantic of 'force' of block-job-cancelLiang Li1-7/+9
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>
2018-03-19blockjobs: Expose manual propertyJohn Snow1-0/+2
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>
2018-03-19blockjobs: add block-job-finalizeJohn Snow1-16/+44
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>
2018-03-19blockjobs: add PENDING status and eventJohn Snow1-24/+43
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>
2018-03-19blockjobs: add waiting statusJohn Snow1-17/+20
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>
2018-03-19blockjobs: add prepare callbackJohn Snow1-3/+27
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>
2018-03-19blockjobs: add block_job_txn_apply functionJohn Snow1-9/+16
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>
2018-03-19blockjobs: add commit, abort, clean helpersJohn Snow1-9/+26
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>
2018-03-19blockjobs: ensure abort is called for cancelled jobsJohn Snow1-5/+16
Presently, even if a job is canceled post-completion as a result of a failing peer in a transaction, it will still call .commit because nothing has updated or changed its return code. The reason why this does not cause problems currently is because backup's implementation of .commit checks for cancellation itself. I'd like to simplify this contract: (1) Abort is called if the job/transaction fails (2) Commit is called if the job/transaction succeeds To this end: A job's return code, if 0, will be forcibly set as -ECANCELED if that job has already concluded. Remove the now redundant check in the backup job implementation. We need to check for cancellation in both block_job_completed AND block_job_completed_single, because jobs may be cancelled between those two calls; for instance in transactions. This also necessitates an ABORTING -> ABORTING transition to be allowed. The check in block_job_completed could be removed, but there's no point in starting to attempt to succeed a transaction that we know in advance will fail. This does NOT affect mirror jobs that are "canceled" during their synchronous phase. The mirror job itself forcibly sets the canceled property to false prior to ceding control, so such cases will invoke the "commit" callback. 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>
2018-03-19blockjobs: add block_job_dismissJohn Snow1-2/+24
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>
2018-03-19blockjobs: add NULL stateJohn Snow1-18/+32
Add a new state that specifically demarcates when we begin to permanently demolish a job after it has performed all work. This makes the transition explicit in the STM table and highlights conditions under which a job may be demolished. Alongside this state, add a new helper command "block_job_decommission", which transitions to the NULL state and puts down our implicit reference. This separates instances in the code for "block_job_unref" which merely undo a matching "block_job_ref" with instances intended to initiate the full destruction of the object. This decommission action also sets a number of fields to make sure that block internals or external users that are holding a reference to a job to see when it "finishes" are convinced that the job object is "done." This is necessary, for instance, to do a block_job_cancel_sync on a created object which will not make any progress. Now, all jobs must go through block_job_decommission prior to being freed, giving us start-to-finish state machine coverage for jobs. Transitions: Created -> Null: Early failure event before the job is started Concluded -> Null: Standard transition. Verbs: None. This should not ever be visible to the monitor. +---------+ |UNDEFINED| +--+------+ | +--v----+ +---------+CREATED+------------------+ | +--+----+ | | | | | +--v----+ +------+ | +---------+RUNNING<----->PAUSED| | | +--+-+--+ +------+ | | | | | | | +------------------+ | | | | | | +--v--+ +-------+ | | +---------+READY<------->STANDBY| | | | +--+--+ +-------+ | | | | | | +--v-----+ +--v------+ | | |ABORTING+--->CONCLUDED<-------------+ | +--------+ +--+------+ | | | +--v-+ | |NULL<---------------------+ +----+ Signed-off-by: John Snow <jsnow@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-03-19blockjobs: add CONCLUDED stateJohn Snow1-15/+24
add a new state "CONCLUDED" that identifies a job that has ceased all operations. The wording was chosen to avoid any phrasing that might imply success, error, or cancellation. The task has simply ceased all operation and can never again perform any work. ("finished", "done", and "completed" might all imply success.) Transitions: Running -> Concluded: normal completion Ready -> Concluded: normal completion Aborting -> Concluded: error and cancellations Verbs: None as of this commit. (a future commit adds 'dismiss') +---------+ |UNDEFINED| +--+------+ | +--v----+ +---------+CREATED| | +--+----+ | | | +--v----+ +------+ +---------+RUNNING<----->PAUSED| | +--+-+--+ +------+ | | | | | +------------------+ | | | | +--v--+ +-------+ | +---------+READY<------->STANDBY| | | +--+--+ +-------+ | | | | +--v-----+ +--v------+ | |ABORTING+--->CONCLUDED<-------------+ +--------+ +---------+ Signed-off-by: John Snow <jsnow@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-03-19blockjobs: add ABORTING stateJohn Snow1-13/+18
Add a new state ABORTING. This makes transitions from normative states to error states explicit in the STM, and serves as a disambiguation for which states may complete normally when normal end-states (CONCLUDED) are added in future commits. Notably, Paused/Standby jobs do not transition directly to aborting, as they must wake up first and cooperate in their cancellation. Transitions: Created -> Aborting: can be cancelled (by the system) Running -> Aborting: can be cancelled or encounter an error Ready -> Aborting: can be cancelled or encounter an error Verbs: None. The job must finish cleaning itself up and report its final status. +---------+ |UNDEFINED| +--+------+ | +--v----+ +---------+CREATED| | +--+----+ | | | +--v----+ +------+ +---------+RUNNING<----->PAUSED| | +--+----+ +------+ | | | +--v--+ +-------+ +---------+READY<------->STANDBY| | +-----+ +-------+ | +--v-----+ |ABORTING| +--------+ 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>
2018-03-19blockjobs: add block_job_verb permission tableJohn Snow1-9/+62
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>
2018-03-19blockjobs: add state transition tableJohn Snow1-7/+33
The state transition table has mostly been implied. We're about to make it a bit more complex, so let's make the STM explicit instead. Perform state transitions with a function that for now just asserts the transition is appropriate. Transitions: Undefined -> Created: During job initialization. Created -> Running: Once the job is started. Jobs cannot transition from "Created" to "Paused" directly, but will instead synchronously transition to running to paused immediately. Running -> Paused: Normal workflow for pauses. Running -> Ready: Normal workflow for jobs reaching their sync point. (e.g. mirror) Ready -> Standby: Normal workflow for pausing ready jobs. Paused -> Running: Normal resume. Standby -> Ready: Resume of a Standby job. +---------+ |UNDEFINED| +--+------+ | +--v----+ |CREATED| +--+----+ | +--v----+ +------+ |RUNNING<----->PAUSED| +--+----+ +------+ | +--v--+ +-------+ |READY<------->STANDBY| +-----+ +-------+ Notably, there is no state presently defined as of this commit that deals with a job after the "running" or "ready" states, so this table will be adjusted alongside the commits that introduce those states. Signed-off-by: John Snow <jsnow@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-03-19blockjobs: add status enumJohn Snow1-0/+9
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>
2018-03-19blockjobs: model single jobs as transactionsJohn Snow1-9/+16
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>
2018-03-19blockjobs: fix set-speed kickJohn Snow1-1/+1
If speed is '0' it's not actually "less than" the previous speed. Kick the job in this case too. 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>
2018-03-02Include less of the generated modular QAPI headersMarkus Armbruster1-1/+1
In my "build everything" tree, a change to the types in qapi-schema.json triggers a recompile of about 4800 out of 5100 objects. The previous commit split up qmp-commands.h, qmp-event.h, qmp-visit.h, qapi-types.h. Each of these headers still includes all its shards. Reduce compile time by including just the shards we actually need. To illustrate the benefits: adding a type to qapi/migration.json now recompiles some 2300 instead of 4800 objects. The next commit will improve it further. Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20180211093607.27351-24-armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> [eblake: rebase to master] Signed-off-by: Eric Blake <eblake@redhat.com>
2018-02-09Drop superfluous includes of qapi/qmp/qjson.hMarkus Armbruster1-1/+0
Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20180201111846.21846-19-armbru@redhat.com>
2018-02-09Include qmp-commands.h exactly where neededMarkus Armbruster1-1/+0
Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20180201111846.21846-7-armbru@redhat.com> [OSX breakage fixed]
2018-02-09Include qapi/error.h exactly where neededMarkus Armbruster1-0/+1
This cleanup makes the number of objects depending on qapi/error.h drop from 1910 (out of 4743) to 1612 in my "build everything" tree. While there, separate #include from file comment with a blank line, and drop a useless comment on why qemu/osdep.h is included first. Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20180201111846.21846-5-armbru@redhat.com> [Semantic conflict with commit 34e304e975 resolved, OSX breakage fixed]
2017-12-22blockjob: Pause job on draining any job BDSKevin Wolf1-13/+9
Block jobs already paused themselves when their main BlockBackend entered a drained section. This is not good enough: We also want to pause a block job and may not submit new requests if, for example, the mirror target node should be drained. This implements .drained_begin/end callbacks in child_job in order to consider all block nodes related to the job, and removes the BlockBackend callbacks which are unnecessary now because the root of the job main BlockBackend is always referenced with a child_job, too. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-12-18blockjob: kick jobs on set-speedJohn Snow1-1/+29
If users set an unreasonably low speed (like one byte per second), the calculated delay may exceed many hours. While we like to punish users for asking for stupid things, we do also like to allow users to correct their wicked ways. When a user provides a new speed, kick the job to allow it to recalculate its delay. Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-id: 20171213204611.26276-1-jsnow@redhat.com Signed-off-by: Jeff Cody <jcody@redhat.com>
2017-12-04blockjob: Make block_job_pause_all() keep a reference to the jobsAlberto Garcia1-2/+5
Starting from commit 40840e419be31e6a32e6ea24511c74b389d5e0e4 we are pausing all block jobs during bdrv_reopen_multiple() to prevent any of them from finishing and removing nodes from the graph while they are being reopened. It turns out that pausing a block job doesn't necessarily prevent it from finishing: a paused block job can still run its exit function from the main loop and call block_job_completed(). The mirror block job in particular always goes to the main loop while it is paused (by virtue of the bdrv_drained_begin() call in mirror_run()). Destroying a paused block job during bdrv_reopen_multiple() has two consequences: 1) The references to the nodes involved in the job are released, possibly destroying some of them. If those nodes were in the reopen queue this would trigger the problem originally described in commit 40840e419be, crashing QEMU. 2) At the end of bdrv_reopen_multiple(), bdrv_drain_all_end() would not be doing all necessary bdrv_parent_drained_end() calls. I can reproduce problem 1) easily with iotest 030 by increasing STREAM_BUFFER_SIZE from 512KB to 8MB in block/stream.c, or by tweaking the iotest like in this example: https://lists.gnu.org/archive/html/qemu-block/2017-11/msg00934.html This patch keeps an additional reference to all block jobs between block_job_pause_all() and block_job_resume_all(), guaranteeing that they are kept alive. Signed-off-by: Alberto Garcia <berto@igalia.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-11-29blockjob: reimplement block_job_sleep_ns to allow cancellationPaolo Bonzini1-11/+52
This reverts the effects of commit 4afeffc857 ("blockjob: do not allow coroutine double entry or entry-after-completion", 2017-11-21) This fixed the symptom of a bug rather than the root cause. Canceling the wait on a sleeping blockjob coroutine is generally fine, we just need to make it work correctly across AioContexts. To do so, use a QEMUTimer that calls block_job_enter. Use a mutex to ensure that block_job_enter synchronizes correctly with block_job_sleep_ns. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Tested-By: Jeff Cody <jcody@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Jeff Cody <jcody@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-11-29blockjob: introduce block_job_do_yieldPaolo Bonzini1-8/+16
Hide the clearing of job->busy in a single function, and set it in block_job_enter. This lets block_job_do_yield verify that qemu_coroutine_enter is not used while job->busy = false. Signed-off-by: Paolo Bonzini <pbonzini@redhat.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>
2017-11-29blockjob: remove clock argument from block_job_sleep_nsPaolo Bonzini1-2/+3
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>
2017-11-28blockjob: Remove the job from the list earlier in block_job_unref()Alberto Garcia1-1/+1
When destroying a block job in block_job_unref() we should remove it from the job list before calling block_job_remove_all_bdrv(). This is because removing the BDSs can trigger an aio_poll() and wake up other jobs that might attempt to use the block job list. If that happens the job we're currently destroying should not be in that list anymore. Signed-off-by: Alberto Garcia <berto@igalia.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-11-21blockjob: do not allow coroutine double entry or entry-after-completionJeff Cody1-2/+5
When block_job_sleep_ns() is called, the co-routine is scheduled for future execution. If we allow the job to be re-entered prior to the scheduled time, we present a race condition in which a coroutine can be entered recursively, or even entered after the coroutine is deleted. The job->busy flag is used by blockjobs when a coroutine is busy executing. The function 'block_job_enter()' obeys the busy flag, and will not enter a coroutine if set. If we sleep a job, we need to leave the busy flag set, so that subsequent calls to block_job_enter() are prevented. This changes the prior behavior of block_job_cancel() being able to immediately wake up and cancel a job; in practice, this should not be an issue, as the coroutine sleep times are generally very small, and the cancel will occur the next time the coroutine wakes up. This fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1508708 Signed-off-by: Jeff Cody <jcody@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-09-04qapi: Mechanically convert FOO_lookup[...] to FOO_str(...)Markus Armbruster1-3/+3
Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <1503564371-26090-14-git-send-email-armbru@redhat.com> Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
2017-06-26fix: avoid an infinite loop or a dangling pointer problem in img_commitsochin.jiang1-2/+2
img_commit could fall into an infinite loop calling run_block_job() if its blockjob fails on any I/O error, fix this already known problem. Signed-off-by: sochin.jiang <sochin.jiang@huawei.com> Message-id: 1497509253-28941-1-git-send-email-sochin.jiang@huawei.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-05-24blockjob: use deferred_to_main_loop to indicate the coroutine has endedPaolo Bonzini1-2/+8
All block jobs are using block_job_defer_to_main_loop as the final step just before the coroutine terminates. At this point, block_job_enter should do nothing, but currently it restarts the freed coroutine. Now, the job->co states should probably be changed to an enum (e.g. BEFORE_START, STARTED, YIELDED, COMPLETED) subsuming block_job_started, job->deferred_to_main_loop and job->busy. For now, this patch eliminates the problematic reenter by removing the reset of job->deferred_to_main_loop (which served no purpose, as far as I could see) and checking the flag in block_job_enter. Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 20170508141310.8674-12-pbonzini@redhat.com Signed-off-by: Jeff Cody <jcody@redhat.com>
2017-05-24blockjob: reorganize block_job_completed_txn_abortPaolo Bonzini1-13/+22
This splits the part that touches job states from the part that invokes callbacks. It will make the code simpler to understand once job states will be protected by a different mutex than the AioContext lock. Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 20170508141310.8674-11-pbonzini@redhat.com Signed-off-by: Jeff Cody <jcody@redhat.com>
2017-05-24blockjob: group BlockJob transaction functions togetherPaolo Bonzini1-64/+64
Yet another pure code movement patch, preparing for the next change. Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 20170508141310.8674-9-pbonzini@redhat.com Signed-off-by: Jeff Cody <jcody@redhat.com>
2017-05-24blockjob: introduce block_job_cancel_async, check iostatus invariantsPaolo Bonzini1-4/+20
The new functions helps respecting the invariant that the coroutine is entered with false user_resume, zero pause count and no error recorded in the iostatus. Resetting the iostatus is now common to all of block_job_cancel_async, block_job_user_resume and block_job_iostatus_reset, albeit with slight differences: - block_job_cancel_async resets the iostatus, and resumes the job if there was an error, but the coroutine is not restarted immediately. For example the caller may continue with a call to block_job_finish_sync. - block_job_user_resume resets the iostatus. It wants to resume the job unconditionally, even if there was no error. - block_job_iostatus_reset doesn't resume the job at all. Maybe that's a bug but it should be fixed separately. block_job_iostatus_reset does the least common denominator, so add some checking but otherwise leave it as the entry point for resetting the iostatus. Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 20170508141310.8674-8-pbonzini@redhat.com Signed-off-by: Jeff Cody <jcody@redhat.com>
2017-05-24blockjob: move iostatus reset inside block_job_user_resumePaolo Bonzini1-5/+6
Outside blockjob.c, the block_job_iostatus_reset function is used once in the monitor and once in BlockBackend. When we introduce the block job mutex, block_job_iostatus_reset's client is going to be the block layer (for which blockjob.c will take the block job mutex) rather than the monitor (which will take the block job mutex by itself). The monitor's call to block_job_iostatus_reset from the monitor comes just before the sole call to block_job_user_resume, so reset the iostatus directly from block_job_iostatus_reset. This will avoid the need to introduce separate block_job_iostatus_reset and block_job_iostatus_reset_locked APIs. After making this change, move the function together with the others that were moved in the previous patch. 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: 20170508141310.8674-7-pbonzini@redhat.com Signed-off-by: Jeff Cody <jcody@redhat.com>
2017-05-24blockjob: separate monitor and blockjob APIsPaolo Bonzini1-185/+205
We have two different headers for block job operations, blockjob.h and blockjob_int.h. The former contains APIs called by the monitor, the latter contains APIs called by the block job drivers and the block layer itself. Keep the two APIs separate in the blockjob.c file too. This will be useful when transitioning away from the AioContext lock, because there will be locking policies for the two categories, too---the monitor will have to call new block_job_lock/unlock APIs, while blockjob APIs will take care of this for the users. Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 20170508141310.8674-6-pbonzini@redhat.com Signed-off-by: Jeff Cody <jcody@redhat.com>
2017-05-24blockjob: introduce block_job_pause/resume_allPaolo Bonzini1-45/+69
Remove use of block_job_pause/resume from outside blockjob.c, thus making them static. The new functions are used by the block layer, so place them in blockjob_int.h. 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: 20170508141310.8674-5-pbonzini@redhat.com Signed-off-by: Jeff Cody <jcody@redhat.com>
2017-05-24blockjob: introduce block_job_early_failPaolo Bonzini1-19/+28
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>
2017-05-24blockjob: remove iostatus_reset callbackPaolo Bonzini1-3/+0
This is unused since commit 66a0fae ("blockjob: Don't touch BDS iostatus", 2016-05-19). Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Jeff Cody <jcody@redhat.com> Message-id: 20170508141310.8674-3-pbonzini@redhat.com Signed-off-by: Jeff Cody <jcody@redhat.com>
2017-05-24blockjob: remove unnecessary checkPaolo Bonzini1-1/+1
!job is always checked prior to the call, drop it from here. Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Jeff Cody <jcody@redhat.com> Message-id: 20170508141310.8674-2-pbonzini@redhat.com Signed-off-by: Jeff Cody <jcody@redhat.com>
2017-04-11blockjob: Use bdrv_coroutine_enter to start coroutineFam Zheng1-2/+2
Resuming and especially starting of the block job coroutine, could be issued in the main thread. However the coroutine's "home" ctx should be set to the same context as job->blk. Use bdrv_coroutine_enter to ensure that. Signed-off-by: Fam Zheng <famz@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com>
2017-03-22blockjob: add devops to blockjob backendsJohn Snow1-5/+24
This lets us hook into drained_begin and drained_end requests from the backend level, which is particularly useful for making sure that all jobs associated with a particular node (whether the source or the target) receive a drain request. Suggested-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Jeff Cody <jcody@redhat.com> Message-id: 20170316212351.13797-4-jsnow@redhat.com Signed-off-by: Jeff Cody <jcody@redhat.com>
2017-03-22blockjob: add block_job_start_shimJohn Snow1-7/+19
The purpose of this shim is to allow us to pause pre-started jobs. The purpose of *that* is to allow us to buffer a pause request that will be able to take effect before the job ever does any work, allowing us to create jobs during a quiescent state (under which they will be automatically paused), then resuming the jobs after the critical section in any order, either: (1) -block_job_start -block_job_resume (via e.g. drained_end) (2) -block_job_resume (via e.g. drained_end) -block_job_start The problem that requires a startup wrapper is the idea that a job must start in the busy=true state only its first time-- all subsequent entries require busy to be false, and the toggling of this state is otherwise handled during existing pause and yield points. The wrapper simply allows us to mandate that a job can "start," set busy to true, then immediately pause only if necessary. We could avoid requiring a wrapper, but all jobs would need to do it, so it's been factored out here. Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Jeff Cody <jcody@redhat.com> Message-id: 20170316212351.13797-2-jsnow@redhat.com Signed-off-by: Jeff Cody <jcody@redhat.com>
2017-03-22blockjob: avoid recursive AioContext lockingPaolo Bonzini1-2/+6
Streaming or any other block job hangs when performed on a block device that has a non-default iothread. This happens because the AioContext is acquired twice by block_job_defer_to_main_loop_bh and then released only once by BDRV_POLL_WHILE. (Insert rants on recursive mutexes, which unfortunately are a temporary but necessary evil for iothreads at the moment). Luckily, the reason for the double acquisition is simple; the function acquires the AioContext for both the job iothread and the BDS iothread, in case the BDS iothread was changed while the job was running. It is therefore enough to skip the second acquisition when the two AioContexts are one and the same. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Jeff Cody <jcody@redhat.com> Message-id: 1490118490-5597-1-git-send-email-pbonzini@redhat.com Signed-off-by: Jeff Cody <jcody@redhat.com>
2017-02-28blockjob: Factor out block_job_remove_all_bdrv()Kevin Wolf1-7/+13
In some cases, we want to remove op blockers on intermediate nodes before the whole block job transaction has completed (because they block restoring the final graph state during completion). Provide a function for this. The whole block job lifecycle is a bit messed up and it's hard to actually do all things in the right order, but I'll leave simplifying this for another day. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Acked-by: Fam Zheng <famz@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2017-02-28blockjob: Add permissions to block_job_add_bdrv()Kevin Wolf1-6/+30
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>
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