Starting from commit 40840e419b 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 40840e419b, 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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
!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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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
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
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
