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* job: remove unused functionsEmanuele Giuseppe Esposito2022-10-071-72/+38Star
| | | | | | | | | | | | | | | | | These public functions are not used anywhere, thus can be dropped. Also, since this is the final job API that doesn't use AioContext lock and replaces it with job_lock, adjust all remaining function documentation to clearly specify if the job lock is taken or not. Also document the locking requirements for a few functions where the second version is not removed. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20220926093214.506243-22-eesposit@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* job.c: enable job lock/unlock and remove Aiocontext locksEmanuele Giuseppe Esposito2022-10-071-8/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Change the job_{lock/unlock} and macros to use job_mutex. Now that they are not nop anymore, remove the aiocontext to avoid deadlocks. Therefore: - when possible, remove completely the aiocontext lock/unlock pair - if it is used by some other function too, reduce the locking section as much as possible, leaving the job API outside. - change AIO_WAIT_WHILE in AIO_WAIT_WHILE_UNLOCKED, since we are not using the aiocontext lock anymore The only functions that still need the aiocontext lock are: - the JobDriver callbacks, already documented in job.h - job_cancel_sync() in replication.c is called with aio_context_lock taken, but now job is using AIO_WAIT_WHILE_UNLOCKED so we need to release the lock. Reduce the locking section to only cover the callback invocation and document the functions that take the AioContext lock, to avoid taking it twice. Also remove real_job_{lock/unlock}, as they are replaced by the public functions. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Message-Id: <20220926093214.506243-19-eesposit@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* job.h: categorize JobDriver callbacks that need the AioContext lockEmanuele Giuseppe Esposito2022-10-071-2/+25
| | | | | | | | | | | Some callbacks implementation use bdrv_* APIs that assume the AioContext lock is held. Make sure this invariant is documented. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> Message-Id: <20220926093214.506243-18-eesposit@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* jobs: protect job.aio_context with BQL and job_mutexEmanuele Giuseppe Esposito2022-10-071-3/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | In order to make it thread safe, implement a "fake rwlock", where we allow reads under BQL *or* job_mutex held, but writes only under BQL *and* job_mutex. The only write we have is in child_job_set_aio_ctx, which always happens under drain (so the job is paused). For this reason, introduce job_set_aio_context and make sure that the context is set under BQL, job_mutex and drain. Also make sure all other places where the aiocontext is read are protected. The reads in commit.c and mirror.c are actually safe, because always done under BQL. Note: at this stage, job_{lock/unlock} and job lock guard macros are *nop*. Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Message-Id: <20220926093214.506243-14-eesposit@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* job.c: add job_lock/unlock while keeping job.h intactEmanuele Giuseppe Esposito2022-10-071-7/+131
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With "intact" we mean that all job.h functions implicitly take the lock. Therefore API callers are unmodified. This means that: - many static functions that will be always called with job lock held become _locked, and call _locked functions - all public functions take the lock internally if needed, and call _locked functions - all public functions called internally by other functions in job.c will have a _locked counterpart (sometimes public), to avoid deadlocks (job lock already taken). These functions are not used for now. - some public functions called only from exernal files (not job.c) do not have _locked() counterpart and take the lock inside. Others won't need the lock at all because use fields only set at initialization and never modified. job_{lock/unlock} is independent from real_job_{lock/unlock}. Note: at this stage, job_{lock/unlock} and job lock guard macros are *nop* Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> Message-Id: <20220926093214.506243-6-eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* job.c: API functions not used outside should be staticEmanuele Giuseppe Esposito2022-10-071-18/+0Star
| | | | | | | | | | | | | | job_event_* functions can all be static, as they are not used outside job.c. Same applies for job_txn_add_job(). Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20220926093214.506243-4-eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* job.h: categorize fields in struct JobEmanuele Giuseppe Esposito2022-10-071-25/+36
| | | | | | | | | | | | Categorize the fields in struct Job to understand which ones need to be protected by the job mutex and which don't. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20220926093214.506243-3-eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* job.c: make job_mutex and job_lock/unlock() publicEmanuele Giuseppe Esposito2022-10-071-0/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | job mutex will be used to protect the job struct elements and list, replacing AioContext locks. Right now use a shared lock for all jobs, in order to keep things simple. Once the AioContext lock is gone, we can introduce per-job locks. To simplify the switch from aiocontext to job lock, introduce *nop* lock/unlock functions and macros. We want to always call job_lock/unlock outside the AioContext locks, and not vice-versa, otherwise we might get a deadlock. This is not straightforward to do, and that's why we start with nop functions. Once everything is protected by job_lock/unlock, we can change the nop into an actual mutex and remove the aiocontext lock. Since job_mutex is already being used, add static real_job_{lock/unlock} for the existing usage. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> Message-Id: <20220926093214.506243-2-eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* job: add missing coroutine_fn annotationsPaolo Bonzini2022-10-071-1/+1
| | | | | | | | | | | | Callers of coroutine_fn must be coroutine_fn themselves, or the call must be within "if (qemu_in_coroutine())". Apply coroutine_fn to functions where this holds. Reviewed-by: Alberto Faria <afaria@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20220922084924.201610-22-pbonzini@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* job.h: split function pointers in JobDriverEmanuele Giuseppe Esposito2022-03-041-0/+22
| | | | | | | | The job API will be handled separately in another serie. Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com> Message-Id: <20220303151616.325444-31-eesposit@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* job: Add job_cancel_requested()Hanna Reitz2021-10-071-1/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Most callers of job_is_cancelled() actually want to know whether the job is on its way to immediate termination. For example, we refuse to pause jobs that are cancelled; but this only makes sense for jobs that are really actually cancelled. A mirror job that is cancelled during READY with force=false should absolutely be allowed to pause. This "cancellation" (which is actually a kind of completion) may take an indefinite amount of time, and so should behave like any job during normal operation. For example, with on-target-error=stop, the job should stop on write errors. (In contrast, force-cancelled jobs should not get write errors, as they should just terminate and not do further I/O.) Therefore, redefine job_is_cancelled() to only return true for jobs that are force-cancelled (which as of HEAD^ means any job that interprets the cancellation request as a request for immediate termination), and add job_cancel_requested() as the general variant, which returns true for any jobs which have been requested to be cancelled, whether it be immediately or after an arbitrarily long completion phase. Finally, here is a justification for how different job_is_cancelled() invocations are treated by this patch: - block/mirror.c (mirror_run()): - The first invocation is a while loop that should loop until the job has been cancelled or scheduled for completion. What kind of cancel does not matter, only the fact that the job is supposed to end. - The second invocation wants to know whether the job has been soft-cancelled. Calling job_cancel_requested() is a bit too broad, but if the job were force-cancelled, we should leave the main loop as soon as possible anyway, so this should not matter here. - The last two invocations already check force_cancel, so they should continue to use job_is_cancelled(). - block/backup.c, block/commit.c, block/stream.c, anything in tests/: These jobs know only force-cancel, so there is no difference between job_is_cancelled() and job_cancel_requested(). We can continue using job_is_cancelled(). - job.c: - job_pause_point(), job_yield(), job_sleep_ns(): Only force-cancelled jobs should be prevented from being paused. Continue using job_is_cancelled(). - job_update_rc(), job_finalize_single(), job_finish_sync(): These functions are all called after the job has left its main loop. The mirror job (the only job that can be soft-cancelled) will clear .cancelled before leaving the main loop if it has been soft-cancelled. Therefore, these functions will observe .cancelled to be true only if the job has been force-cancelled. We can continue to use job_is_cancelled(). (Furthermore, conceptually, a soft-cancelled mirror job should not report to have been cancelled. It should report completion (see also the block-job-cancel QAPI documentation). Therefore, it makes sense for these functions not to distinguish between a soft-cancelled mirror job and a job that has completed as normal.) - job_completed_txn_abort(): All jobs other than @job have been force-cancelled. job_is_cancelled() must be true for them. Regarding @job itself: job_completed_txn_abort() is mostly called when the job's return value is not 0. A soft-cancelled mirror has a return value of 0, and so will not end up here then. However, job_cancel() invokes job_completed_txn_abort() if the job has been deferred to the main loop, which is mostly the case for completed jobs (which skip the assertion), but not for sure. To be safe, use job_cancel_requested() in this assertion. - job_complete(): This is function eventually invoked by the user (through qmp_block_job_complete() or qmp_job_complete(), or job_complete_sync(), which comes from qemu-img). The intention here is to prevent a user from invoking job-complete after the job has been cancelled. This should also apply to soft cancelling: After a mirror job has been soft-cancelled, the user should not be able to decide otherwise and have it complete as normal (i.e. pivoting to the target). - job_cancel(): Both functions are equivalent (see comment there), but we want to use job_is_cancelled(), because this shows that we call job_completed_txn_abort() only for force-cancelled jobs. (As explained for job_update_rc(), soft-cancelled jobs should be treated as if they have completed as normal.) Buglink: https://gitlab.com/qemu-project/qemu/-/issues/462 Signed-off-by: Hanna Reitz <hreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20211006151940.214590-9-hreitz@redhat.com> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
* jobs: Give Job.force_cancel more meaningHanna Reitz2021-10-071-1/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We largely have two cancel modes for jobs: First, there is actual cancelling. The job is terminated as soon as possible, without trying to reach a consistent result. Second, we have mirror in the READY state. Technically, the job is not really cancelled, but it just is a different completion mode. The job can still run for an indefinite amount of time while it tries to reach a consistent result. We want to be able to clearly distinguish which cancel mode a job is in (when it has been cancelled). We can use Job.force_cancel for this, but right now it only reflects cancel requests from the user with force=true, but clearly, jobs that do not even distinguish between force=false and force=true are effectively always force-cancelled. So this patch has Job.force_cancel signify whether the job will terminate as soon as possible (force_cancel=true) or whether it will effectively remain running despite being "cancelled" (force_cancel=false). To this end, we let jobs that provide JobDriver.cancel() tell the generic job code whether they will terminate as soon as possible or not, and for jobs that do not provide that method we assume they will. Signed-off-by: Hanna Reitz <hreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-Id: <20211006151940.214590-7-hreitz@redhat.com> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
* job: @force parameter for job_cancel_sync()Hanna Reitz2021-10-071-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Callers should be able to specify whether they want job_cancel_sync() to force-cancel the job or not. In fact, almost all invocations do not care about consistency of the result and just want the job to terminate as soon as possible, so they should pass force=true. The replication block driver is the exception, specifically the active commit job it runs. As for job_cancel_sync_all(), all callers want it to force-cancel all jobs, because that is the point of it: To cancel all remaining jobs as quickly as possible (generally on process termination). So make it invoke job_cancel_sync() with force=true. This changes some iotest outputs, because quitting qemu while a mirror job is active will now lead to it being cancelled instead of completed, which is what we want. (Cancelling a READY mirror job with force=false may take an indefinite amount of time, which we do not want when quitting. If users want consistent results, they must have all jobs be done before they quit qemu.) Buglink: https://gitlab.com/qemu-project/qemu/-/issues/462 Signed-off-by: Hanna Reitz <hreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20211006151940.214590-6-hreitz@redhat.com> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
* mirror: stop cancelling in-flight requests on non-force cancel in READYVladimir Sementsov-Ogievskiy2021-05-141-1/+1
| | | | | | | | | | | | | | | | | | | If mirror is READY than cancel operation is not discarding the whole result of the operation, but instead it's a documented way get a point-in-time snapshot of source disk. So, we should not cancel any requests if mirror is READ and force=false. Let's fix that case. Note, that bug that we have before this commit is not critical, as the only .bdrv_cancel_in_flight implementation is nbd_cancel_in_flight() and it cancels only requests waiting for reconnection, so it should be rare case. Fixes: 521ff8b779b11c394dbdc43f02e158dd99df308a Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20210421075858.40197-1-vsementsov@virtuozzo.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
* job: add .cancel handler for the driverVladimir Sementsov-Ogievskiy2021-02-121-0/+5
| | | | | | | | | | To be used in mirror in the following commit to cancel in-flight io on target to not waste the time. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20210205163720.887197-5-vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Eric Blake <eblake@redhat.com>
* job: refactor progress to separate objectVladimir Sementsov-Ogievskiy2020-03-111-9/+2Star
| | | | | | | | | | | | We need it in separate to pass to the block-copy object in the next commit. Cc: qemu-stable@nongnu.org Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20200311103004.7649-2-vsementsov@virtuozzo.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
* job: drop job_drainVladimir Sementsov-Ogievskiy2019-09-101-13/+0Star
| | | | | | | | | | | | In job_finish_sync job_enter should be enough for a job to make some progress and draining is a wrong tool for it. So use job_enter directly here and drop job_drain with all related staff not used more. Suggested-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Tested-by: John Snow <jsnow@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* Include generated QAPI headers lessMarkus Armbruster2019-08-161-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some of the generated qapi-types-MODULE.h are included all over the place. Changing a QAPI type can trigger massive recompiling. Top scorers recompile more than 1000 out of some 6600 objects (not counting tests and objects that don't depend on qemu/osdep.h): 6300 qapi/qapi-builtin-types.h 5700 qapi/qapi-types-run-state.h 3900 qapi/qapi-types-common.h 3300 qapi/qapi-types-sockets.h 3000 qapi/qapi-types-misc.h 3000 qapi/qapi-types-crypto.h 3000 qapi/qapi-types-job.h 3000 qapi/qapi-types-block-core.h 2800 qapi/qapi-types-block.h 1300 qapi/qapi-types-net.h Clean up headers to include generated QAPI headers only where needed. Impact is negligible except for hw/qdev-properties.h. This header includes qapi/qapi-types-block.h and qapi/qapi-types-misc.h. They are used only in expansions of property definition macros such as DEFINE_PROP_BLOCKDEV_ON_ERROR() and DEFINE_PROP_OFF_AUTO(). Moving their inclusion from hw/qdev-properties.h to the users of these macros avoids pointless recompiles. This is how other property definition macros, such as DEFINE_PROP_NETDEV(), already work. Improves things for some of the top scorers: 3600 qapi/qapi-types-common.h 2800 qapi/qapi-types-sockets.h 900 qapi/qapi-types-misc.h 2200 qapi/qapi-types-crypto.h 2100 qapi/qapi-types-job.h 2100 qapi/qapi-types-block-core.h 270 qapi/qapi-types-block.h Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com> Message-Id: <20190812052359.30071-3-armbru@redhat.com>
* blockjob: Lie better in child_job_drained_poll()Kevin Wolf2018-09-251-0/+3
| | | | | | | | | | | | | | | | | | | | | | | Block jobs claim in .drained_poll() that they are in a quiescent state as soon as job->deferred_to_main_loop is true. This is obviously wrong, they still have a completion BH to run. We only get away with this because commit 91af091f923 added an unconditional aio_poll(false) to the drain functions, but this is bypassing the regular drain mechanisms. However, just removing this and telling that the job is still active doesn't work either: The completion callbacks themselves call drain functions (directly, or indirectly with bdrv_reopen), so they would deadlock then. As a better lie, tell that the job is active as long as the BH is pending, but falsely call it quiescent from the point in the BH when the completion callback is called. At this point, nested drain calls won't deadlock because they ignore the job, and outer drains will wait for the job to really reach a quiescent state because the callback is already running. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
* test-blockjob: Acquire AioContext around job_cancel_sync()Kevin Wolf2018-09-251-0/+6
| | | | | | | | | All callers in QEMU proper hold the AioContext lock when calling job_finish_sync(). test-blockjob should do the same when it calls the function indirectly through job_cancel_sync(). Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com>
* blockjob: Wake up BDS when job becomes idleKevin Wolf2018-09-251-0/+3
| | | | | | | | | | | | | | | | | In the context of draining a BDS, the .drained_poll callback of block jobs is called. If this returns true (i.e. there is still some activity pending), the drain operation may call aio_poll() with blocking=true to wait for completion. As soon as the pending activity is completed and the job finally arrives in a quiescent state (i.e. its coroutine either yields with busy=false or terminates), the block job must notify the aio_poll() loop to wake up, otherwise we get a deadlock if both are running in different threads. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
* jobs: remove .exit callbackJohn Snow2018-09-251-11/+0Star
| | | | | | | | | | | | | | | | | Now that all of the jobs use the component finalization callbacks, there's no use for the heavy-hammer .exit callback anymore. job_exit becomes a glorified type shim so that we can call job_completed from aio_bh_schedule_oneshot. Move these three functions down into job.c to eliminate a forward reference. Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-id: 20180906130225.5118-12-jsnow@redhat.com Reviewed-by: Jeff Cody <jcody@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
* jobs: remove job_defer_to_main_loopJohn Snow2018-08-311-17/+0Star
| | | | | | | | | | | Now that the job infrastructure is handling the job_completed call for all implemented jobs, we can remove the interface that allowed jobs to schedule their own completion. Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-id: 20180830015734.19765-10-jsnow@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
* jobs: remove ret argument to job_completed; privatize itJohn Snow2018-08-311-13/+15
| | | | | | | | | | | | | | | | | Jobs are now expected to return their retcode on the stack, from the .run callback, so we can remove that argument. job_cancel does not need to set -ECANCELED because job_completed will update the return code itself if the job was canceled. While we're here, make job_completed static to job.c and remove it from job.h; move the documentation of return code to the .run() callback and to the job->ret property, accordingly. Signed-off-by: John Snow <jsnow@redhat.com> Message-id: 20180830015734.19765-9-jsnow@redhat.com Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
* jobs: add exit shimJohn Snow2018-08-311-0/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | All jobs do the same thing when they leave their running loop: - Store the return code in a structure - wait to receive this structure in the main thread - signal job completion via job_completed Few jobs do anything beyond exactly this. Consolidate this exit logic for a net reduction in SLOC. More seriously, when we utilize job_defer_to_main_loop_bh to call a function that calls job_completed, job_finalize_single will run in a context where it has recursively taken the aio_context lock, which can cause hangs if it puts down a reference that causes a flush. You can observe this in practice by looking at mirror_exit's careful placement of job_completed and bdrv_unref calls. If we centralize job exiting, we can signal job completion from outside of the aio_context, which should allow for job cleanup code to run with only one lock, which makes cleanup callbacks less tricky to write. Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-id: 20180830015734.19765-4-jsnow@redhat.com Reviewed-by: Jeff Cody <jcody@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
* jobs: canonize Error objectJohn Snow2018-08-311-6/+8
| | | | | | | | | | | | | | | Jobs presently use both an Error object in the case of the create job, and char strings in the case of generic errors elsewhere. Unify the two paths as just j->err, and remove the extra argument from job_completed. The integer error code for job_completed is kept for now, to be removed shortly in a separate patch. Signed-off-by: John Snow <jsnow@redhat.com> Message-id: 20180830015734.19765-3-jsnow@redhat.com [mreitz: Dropped a superfluous g_strdup()] Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
* jobs: change start callback to run callbackJohn Snow2018-08-311-1/+1
| | | | | | | | | | | | | | | | | | Presently we codify the entry point for a job as the "start" callback, but a more apt name would be "run" to clarify the idea that when this function returns we consider the job to have "finished," except for any cleanup which occurs in separate callbacks later. As part of this clarification, change the signature to include an error object and a return code. The error ptr is not yet used, and the return code while captured, will be overwritten by actions in the job_completed function. Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-id: 20180830015734.19765-2-jsnow@redhat.com Reviewed-by: Jeff Cody <jcody@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
* job: Add job_progress_increase_remaining()Max Reitz2018-06-181-0/+15
| | | | | | | Signed-off-by: Max Reitz <mreitz@redhat.com> Message-id: 20180613181823.13618-12-mreitz@redhat.com Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
* job: Add error message for failing jobsKevin Wolf2018-05-301-1/+6
| | | | | | | | | | | | | | | | | So far we relied on job->ret and strerror() to produce an error message for failed jobs. Not surprisingly, this tends to result in completely useless messages. This adds a Job.error field that can contain an error string for a failing job, and a parameter to job_completed() that sets the field. As a default, if NULL is passed, we continue to use strerror(job->ret). All existing callers are changed to pass NULL. They can be improved in separate patches. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Jeff Cody <jcody@redhat.com>
* job: Add query-jobs QMP commandKevin Wolf2018-05-231-0/+3
| | | | | | | | This adds a minimal query-jobs implementation that shouldn't pose many design questions. It can later be extended to expose more information, and especially job-specific information. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* job: Move progress fields to JobKevin Wolf2018-05-231-0/+28
| | | | | | | | | | | | 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>
* job: Add job_transition_to_ready()Kevin Wolf2018-05-231-3/+6
| | | | | | | | | | | | 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>
* job: Add job_is_ready()Kevin Wolf2018-05-231-0/+3
| | | | | | | | | | | | | | | | | | | 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 ef6dbf1e46e, 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>
* job: Add job_dismiss()Kevin Wolf2018-05-231-1/+6
| | | | | | | This moves block_job_dismiss() to the Job layer. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
* job: Add job_yield()Kevin Wolf2018-05-231-2/+7
| | | | | | | This moves block_job_yield() to the Job layer. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
* job: Move completion and cancellation to JobKevin Wolf2018-05-231-11/+57
| | | | | | | This moves the top-level job completion and cancellation functions from BlockJob to Job. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
* job: Move transactions to JobKevin Wolf2018-05-231-9/+62
| | | | | | | | 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>
* job: Switch transactions to JobTxnKevin Wolf2018-05-231-0/+3
| | | | | | | | | 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>
* job: Move job_finish_sync() to JobKevin Wolf2018-05-231-0/+9
| | | | | | | | 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>
* job: Move .complete callback to JobKevin Wolf2018-05-231-0/+8
| | | | | | | | | | 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>
* job: Add job_drain()Kevin Wolf2018-05-231-0/+13
| | | | | | | | | | | 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>
* job: Convert block_job_cancel_async() to JobKevin Wolf2018-05-231-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* job: Move single job finalisation to JobKevin Wolf2018-05-231-1/+52
| | | | | | | | | | | 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>
* job: Add job_event_*()Kevin Wolf2018-05-231-0/+18
| | | | | | | | | | | | | 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>
* job: Move BlockJobCreateFlags to JobKevin Wolf2018-05-231-1/+19
| | | | | | | | | 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>
* job: Replace BlockJob.completed with job_is_completed()Kevin Wolf2018-05-231-0/+3
| | | | | | | | | | | 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>
* job: Move pause/resume functions to JobKevin Wolf2018-05-231-0/+37
| | | | | | | | | | 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>
* job: Add job_sleep_ns()Kevin Wolf2018-05-231-1/+18
| | | | | | | | | 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>
* job: Move coroutine and related code to JobKevin Wolf2018-05-231-0/+76
| | | | | | | | | | 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>
* job: Move defer_to_main_loop to JobKevin Wolf2018-05-231-0/+20
| | | | | | | | | | | | | | | | | | | 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>
generated by cgit v1.2.3-55-g7522 (git 2.39.0) at 2024-12-22 19:05:28 +0100