aboutsummaryrefslogtreecommitdiff
path: root/blockjob.c
AgeCommit message (Collapse)Author
2017-11-21blockjob: do not allow coroutine double entry or entry-after-completionJeff Cody
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 Armbruster
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.jiang
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 Bonzini
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 Bonzini
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 Bonzini
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 Bonzini
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 Bonzini
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 Bonzini
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 Bonzini
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 Bonzini
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 Bonzini
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 Bonzini
!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 Zheng
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 Snow
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 Snow
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 Bonzini
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 Wolf
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 Wolf
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>
2017-02-28blockjob: Add permissions to block_job_create()Kevin Wolf
This functions creates a BlockBackend internally, so the block jobs need to tell it what they want to do with the BB. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Acked-by: Fam Zheng <famz@redhat.com>
2017-02-28block: Add error parameter to blk_insert_bs()Kevin Wolf
Now that blk_insert_bs() requests the BlockBackend permissions for the node it attaches to, it can fail. Instead of aborting, pass the errors to the callers. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Acked-by: Fam Zheng <famz@redhat.com>
2017-02-28block: Add permissions to blk_new()Kevin Wolf
We want every user to be specific about the permissions it needs, so we'll pass the initial permissions as parameters to blk_new(). A user only needs to call blk_set_perm() if it wants to change the permissions after the fact. The permissions are stored in the BlockBackend and applied whenever a BlockDriverState should be attached in blk_insert_bs(). This does not include actually choosing the right set of permissions everywhere yet. Instead, the usual FIXME comment is added to each place and will be addressed in individual patches. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Acked-by: Fam Zheng <famz@redhat.com>
2017-01-31trace: switch to modular code generation for sub-directoriesDaniel P. Berrange
Introduce rules in the top level Makefile that are able to generate trace.[ch] files in every subdirectory which has a trace-events file. The top level directory is handled specially, so instead of creating trace.h, it creates trace-root.h. This allows sub-directories to include the top level trace-root.h file, without ambiguity wrt to the trace.g file in the current sub-dir. Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Daniel P. Berrange <berrange@redhat.com> Message-id: 20170125161417.31949-7-berrange@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-11-14blockjob: add block_job_startJohn Snow
Instead of automatically starting jobs at creation time via backup_start et al, we'd like to return a job object pointer that can be started manually at later point in time. For now, add the block_job_start mechanism and start the jobs automatically as we have been doing, with conversions job-by-job coming in later patches. Of note: cancellation of unstarted jobs will perform all the normal cleanup as if the job had started, particularly abort and clean. The only difference is that we will not emit any events, because the job never actually started. Signed-off-by: John Snow <jsnow@redhat.com> Message-id: 1478587839-9834-5-git-send-email-jsnow@redhat.com Signed-off-by: Jeff Cody <jcody@redhat.com>
2016-11-14blockjob: add .clean propertyJohn Snow
Cleaning up after we have deferred to the main thread but before the transaction has converged can be dangerous and result in deadlocks if the job cleanup invokes any BH polling loops. A job may attempt to begin cleaning up, but may induce another job to enter its cleanup routine. The second job, part of our same transaction, will block waiting for the first job to finish, so neither job may now make progress. To rectify this, allow jobs to register a cleanup operation that will always run regardless of if the job was in a transaction or not, and if the transaction job group completed successfully or not. Move sensitive cleanup to this callback instead which is guaranteed to be run only after the transaction has converged, which removes sensitive timing constraints from said cleanup. Furthermore, in future patches these cleanup operations will be performed regardless of whether or not we actually started the job. Therefore, cleanup callbacks should essentially confine themselves to undoing create operations, e.g. setup actions taken in what is now backup_start. Reported-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Message-id: 1478587839-9834-3-git-send-email-jsnow@redhat.com Signed-off-by: Jeff Cody <jcody@redhat.com>
2016-11-14blockjob: fix dead pointer in txn listVladimir Sementsov-Ogievskiy
Though it is not intended to be reached through normal circumstances, if we do not gracefully deconstruct the transaction QLIST, we may wind up with stale pointers in the list. The rest of this series attempts to address the underlying issues, but this should fix list inconsistencies. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Tested-by: John Snow <jsnow@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: John Snow <jsnow@redhat.com> Message-id: 1478587839-9834-2-git-send-email-jsnow@redhat.com [Rewrote commit message. --js] 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: John Snow <jsnow@redhat.com> Signed-off-by: Jeff Cody <jcody@redhat.com>
2016-11-01blockjobs: split interface into public/private, Part 1John Snow
To make it a little more obvious which functions are intended to be public interface and which are intended to be for use only by jobs themselves, split the interface into "public" and "private" files. Convert blockjobs (e.g. block/backup) to using the private interface. Leave blockdev and others on the public interface. There are remaining uses of private state by qemu-img, and several cases in blockdev.c and block/io.c where we grab job->blk for the purposes of acquiring an AIOContext. These will be corrected in future patches. Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Jeff Cody <jcody@redhat.com> Message-id: 1477584421-1399-7-git-send-email-jsnow@redhat.com Signed-off-by: Jeff Cody <jcody@redhat.com>
2016-11-01Blockjobs: Internalize user_pause logicJohn Snow
BlockJobs will begin hiding their state in preparation for some refactorings anyway, so let's internalize the user_pause mechanism instead of leaving it to callers to correctly manage. Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Jeff Cody <jcody@redhat.com> Message-id: 1477584421-1399-6-git-send-email-jsnow@redhat.com Signed-off-by: Jeff Cody <jcody@redhat.com>
2016-11-01blockjob: centralize QMP event emissionsJohn Snow
There's no reason to leave this to blockdev; we can do it in blockjobs directly and get rid of an extra callback for most users. All non-internal events, even those created outside of QMP, will consistently emit events. Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Jeff Cody <jcody@redhat.com> Message-id: 1477584421-1399-5-git-send-email-jsnow@redhat.com Signed-off-by: Jeff Cody <jcody@redhat.com>
2016-11-01blockjobs: Allow creating internal jobsJohn Snow
Add the ability to create jobs without an ID. Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Jeff Cody <jcody@redhat.com> Message-id: 1477584421-1399-3-git-send-email-jsnow@redhat.com Signed-off-by: Jeff Cody <jcody@redhat.com>
2016-11-01blockjobs: hide internal jobs from management APIJohn Snow
If jobs are not created directly by the user, do not allow them to be seen by the user/management utility. At the moment, 'internal' jobs are those that do not have an ID. As of this patch it is impossible to create such jobs. Signed-off-by: John Snow <jsnow@redhat.com> Message-id: 1477584421-1399-2-git-send-email-jsnow@redhat.com Signed-off-by: Jeff Cody <jcody@redhat.com>
2016-10-31block: Add block_job_add_bdrv()Alberto Garcia
When a block job is created on a certain BlockDriverState, operations are blocked there while the job exists. However, some block jobs may involve additional BDSs, which must be blocked separately when the job is created and unblocked manually afterwards. This patch adds block_job_add_bdrv(), that simplifies this process by keeping a list of BDSs that are involved in the specified block job. Signed-off-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-10-28blockjob: introduce .drain callback for jobsPaolo Bonzini
This is required to decouple block jobs from running in an AioContext. With multiqueue block devices, a BlockDriverState does not really belong to a single AioContext. The solution is to first wait until all I/O operations are complete; then loop in the main thread for the block job to complete entirely. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Message-Id: <1477565348-5458-3-git-send-email-pbonzini@redhat.com> Signed-off-by: Fam Zheng <famz@redhat.com>
2016-10-07block: use aio_bh_schedule_oneshotPaolo Bonzini
This simplifies bottom half handlers by removing calls to qemu_bh_delete and thus removing the need to stash the bottom half pointer in the opaque datum. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-09-05block jobs: Improve error message for missing job IDKevin Wolf
If a block job is started with a node name rather than a device name and no explicit job ID is passed, it was reported that '' isn't a well-formed ID. Which is correct, but we can make the message a little bit nicer. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Jeff Cody <jcody@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-13block/qdev: Allow configuring rerror/werror with qdev propertiesKevin Wolf
The rerror/werror policies are implemented in the devices, so that's where they should be configured. In comparison to the old options in -drive, the qdev properties are only added to those devices that actually support them. If the option isn't given (or "auto" is specified), the setting of the BlockBackend is used for compatibility with the old options. For block jobs, "auto" is the same as "enospc". Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com>
2016-07-13coroutine: move entry argument to qemu_coroutine_createPaolo Bonzini
In practice the entry argument is always known at creation time, and it is confusing that sometimes qemu_coroutine_enter is used with a non-NULL argument to re-enter a coroutine (this happens in block/sheepdog.c and tests/test-coroutine.c). So pass the opaque value at creation time, for consistency with e.g. aio_bh_new. Mostly done with the following semantic patch: @ entry1 @ expression entry, arg, co; @@ - co = qemu_coroutine_create(entry); + co = qemu_coroutine_create(entry, arg); ... - qemu_coroutine_enter(co, arg); + qemu_coroutine_enter(co); @ entry2 @ expression entry, arg; identifier co; @@ - Coroutine *co = qemu_coroutine_create(entry); + Coroutine *co = qemu_coroutine_create(entry, arg); ... - qemu_coroutine_enter(co, arg); + qemu_coroutine_enter(co); @ entry3 @ expression entry, arg; @@ - qemu_coroutine_enter(qemu_coroutine_create(entry), arg); + qemu_coroutine_enter(qemu_coroutine_create(entry, arg)); @ reentry @ expression co; @@ - qemu_coroutine_enter(co, NULL); + qemu_coroutine_enter(co); except for the aforementioned few places where the semantic patch stumbled (as expected) and for test_co_queue, which would otherwise produce an uninitialized variable warning. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-07-13qemu-img: Set the ID of the block job in img_commit()Alberto Garcia
img_commit() creates a block job without an ID. This is no longer allowed now that we require it to be unique and well-formed. We were solving this by having a fallback in block_job_create(), but now that we extended the API of commit_active_start() we can finally set an explicit ID and revert that change. Signed-off-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-07-13blockjob: Add 'job_id' parameter to block_job_create()Alberto Garcia
When a new job is created, the job ID is taken from the device name of the BDS. This patch adds a new 'job_id' parameter to let the caller provide one instead. This patch also verifies that the ID is always unique and well-formed. This causes problems in a couple of places where no ID is being set, because the BDS does not have a device name. In the case of test_block_job_start() (from test-blockjob-txn.c) we can simply use this new 'job_id' parameter to set the missing ID. In the case of img_commit() (from qemu-img.c) we still don't have the API to make commit_active_start() set the job ID, so we solve it by setting a default value. We'll get rid of this as soon as we extend the API. Signed-off-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-07-13blockjob: Add block_job_get()Alberto Garcia
Currently the way to look for a specific block job is to iterate the list manually using block_job_next(). Since we want to be able to identify a job primarily by its ID it makes sense to have a function that does just that. Signed-off-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-07-13blockjob: Update description of the 'id' fieldAlberto Garcia
The 'id' field of the BlockJob structure will be able to hold any ID, not only a device name. This patch updates the description of that field and the error messages where it is being used. Soon we'll add the ability to set an arbitrary ID when creating a block job. Signed-off-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-06-28blockjob: assert(cb) when create jobChanglong Xie
Callback for block job should always exist Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Suggested-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Changlong Xie <xiecl.fnst@cn.fujitsu.com> Reviewed-by: Fam Zheng <famz@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Jeff Cody <jcody@redhat.com> Message-id: 1466672241-22485-2-git-send-email-xiecl.fnst@cn.fujitsu.com Signed-off-by: Jeff Cody <jcody@redhat.com>
2016-06-20blockjob: add AioContext attached callbackStefan Hajnoczi
Block jobs that use additional BDSes or event loop resources need a callback to get their affairs in order when the AioContext is switched. Simple block jobs don't need an attach callback, they automatically work thanks to the generic attach/detach notifiers that this patch adds. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Message-id: 1466096189-6477-7-git-send-email-stefanha@redhat.com
2016-06-20blockjob: add block_job_get_aio_context()Stefan Hajnoczi
Add a helper function to document why block jobs sometimes run in the QEMU main loop and to avoid code duplication in a following patch. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Message-id: 1466096189-6477-5-git-send-email-stefanha@redhat.com
2016-06-20blockjob: add pause pointsStefan Hajnoczi
Block jobs are coroutines that usually perform I/O but sometimes also sleep or yield. Currently only sleeping or yielded block jobs can be paused. This means jobs that do not sleep or yield (using block_job_yield()) are unaffected by block_job_pause(). Add block_job_pause_point() so that block jobs can mark quiescent points that are suitable for pausing. This solves the problem that it can take a block job a long time to pause if it is performing a long series of I/O operations. Transitioning to paused state involves a .pause()/.resume() callback. These callbacks are used to ensure that I/O and event loop activity has ceased while the job is at a pause point. Note that this patch introduces a stricter pause state than previously. The job->busy flag was incorrectly documented as a quiescent state without I/O pending. This is violated by any job that has I/O pending across sleep or block_job_yield(), like the mirror block job. [Add missing block_job_should_pause() check to avoid deadlock after job->driver->pause() in block_job_pause_point(). --Stefan] Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Message-id: 1466096189-6477-4-git-send-email-stefanha@redhat.com
2016-06-20blockjob: rename block_job_is_paused()Stefan Hajnoczi
The block_job_is_paused() function name is not great because callers only use it to determine whether pausing has been requested. Rename it to highlight those semantics and remove it from the public header file as there are no external callers. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Message-id: 1466096189-6477-3-git-send-email-stefanha@redhat.com
2016-06-20blockjob: move iostatus reset out of block_job_enter()Stefan Hajnoczi
The QMP block-job-resume command and cancellation may want to reset the job's iostatus. The next patches add a user who does not want to reset iostatus so move it up to block_job_enter() callers. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 1466096189-6477-2-git-send-email-stefanha@redhat.com
2016-06-16block: Prevent sleeping jobs from resuming if they have been pausedAlberto Garcia
If we pause a block job and drain its BlockDriverState we want that the job remains inactive until we call block_job_resume() again. However if we pause the job while it is sleeping then it will resume when the sleep timer fires. This patch prevents that from happening by checking if the job has been paused after it comes back from sleeping. Signed-off-by: Alberto Garcia <berto@igalia.com> Suggested-by: Kevin Wolf <kwolf@redhat.com> Message-id: 3d9011151512326b890d22bdab3530244ef349d7.1464346103.git.berto@igalia.com Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-05-25blockjob: Remove BlockJob.bsKevin Wolf
There is a single remaining user in qemu-img, and another one in a test case, both of which can be trivially converted to using BlockJob.blk instead. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2016-05-25block: Convert block job core to BlockBackendKevin Wolf
This adds a new BlockBackend field to the BlockJob struct, which coexists with the BlockDriverState while converting the individual jobs. When creating a block job, a new BlockBackend is created on top of the given BlockDriverState, and it is destroyed when the BlockJob ends. The reference to the BDS is now held by the BlockBackend instead of calling bdrv_ref/unref manually. We have to be careful when we use bdrv_replace_in_backing_chain() in block jobs because this changes the BDS that job->blk points to. At the moment block jobs are too tightly coupled with their BDS, so that moving a job to another BDS isn't easily possible; therefore, we need to just manually undo this change afterwards. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Max Reitz <mreitz@redhat.com>