Like for query-block, the client needs to identify which BlockBackend
the returned data is for. Anonymous BlockBackends are identified by the
device model they are attached to. Add a 'qdev' field that contains the
qdev ID or QOM path of the attached device model.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
This was accidentally omitted. Thanks to Eric Blake for spotting this.
Signed-off-by: Ari Sundholm <ari@tuxera.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This is a way to ensure that the log superblock is periodically
updated. Before, this was only done on flush requests, which may
not be enough if the VM exits abnormally, omitting the final flush.
The default interval is 4096 write requests.
Signed-off-by: Ari Sundholm <ari@tuxera.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Suggested by Kevin Wolf. May be useful when testing multiple batches
of writes or doing long-term testing involving restarts of the VM.
Signed-off-by: Ari Sundholm <ari@tuxera.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Implements a block device write logging system, similar to Linux kernel
device mapper dm-log-writes. The write operations that are performed
on a block device are logged to a file or another block device. The
write log format is identical to the dm-log-writes format. Currently,
log markers are not supported.
This functionality can be used for crash consistency and fs consistency
testing. By implementing it in qemu, tests utilizing write logs can be
be used to test non-Linux drivers and older kernels.
The driver accepts an optional parameter to set the sector size used
for logging. This makes the driver require all requests to be aligned
to this sector size and also makes offsets and sizes of writes in the
log metadata to be expressed in terms of this value (the log format has
a granularity of one sector for offsets and sizes). This allows
accurate logging of writes to guest block devices that have unusual
sector sizes.
The implementation is based on the blkverify and blkdebug block
drivers.
Signed-off-by: Aapo Vienamo <aapo@tuxera.com>
Signed-off-by: Ari Sundholm <ari@tuxera.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
In order to test that the NBD server is properly advertising
dirty bitmaps, we need a bare minimum client that can request
and read the context. Since feature freeze for 3.0 is imminent,
this is the smallest workable patch, which replaces the qemu
block status report with the results of the NBD server's dirty
bitmap (making it very easy to use 'qemu-img map --output=json'
to learn where the dirty portions are). Note that the NBD
protocol defines a dirty section with the same bit but opposite
sense that normal "base:allocation" uses to report an allocated
section; so in qemu-img map output, "data":true corresponds to
clean, "data":false corresponds to dirty.
A more complete solution that allows dirty bitmaps to be queried
at the same time as normal block status will be required before
this addition can lose the x- prefix. Until then, the fact that
this replaces normal status with dirty status means actions
like 'qemu-img convert' will likely misbehave due to treating
dirty regions of the file as if they are unallocated.
The next patch adds an iotest to exercise this new code.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180702191458.28741-2-eblake@redhat.com>
Flat unions may now have uncovered branches, so it is possible to get rid
of empty types defined for that purpose only.
Signed-off-by: Anton Nefedov <anton.nefedov@virtuozzo.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1529311206-76847-3-git-send-email-anton.nefedov@virtuozzo.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
This patch allows the user to specify whether to use active or only
background mode for mirror block jobs. Currently, this setting will
remain constant for the duration of the entire block job.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-id: 20180613181823.13618-14-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
This patch implements active synchronous mirroring. In active mode, the
passive mechanism will still be in place and is used to copy all
initially dirty clusters off the source disk; but every write request
will write data both to the source and the target disk, so the source
cannot be dirtied faster than data is mirrored to the target. Also,
once the block job has converged (BLOCK_JOB_READY sent), source and
target are guaranteed to stay in sync (unless an error occurs).
Active mode is completely optional and currently disabled at runtime. A
later patch will add a way for users to enable it.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Message-id: 20180613181823.13618-13-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
Legacy -drive supports "password-secret" parameter that isn't
available with -blockdev / blockdev-add. That's because we backed out
our first try to provide it there due to interface design doubts, in
commit 577d8c9a81, v2.9.0.
This is the second try. It brings back the parameter, except it's
named "key-secret" now.
Let's review our reasons for backing out the first try, as stated in
the commit message:
* BlockdevOptionsRbd member @password-secret isn't actually a
password, it's a key generated by Ceph.
Addressed by the rename.
* We're not sure where member @password-secret belongs (see the
previous commit).
See previous commit.
* How @password-secret interacts with settings from a configuration
file specified with @conf is undocumented.
Not actually true, the documentation for @conf says "Values in the
configuration file will be overridden by options specified via QAPI",
and we've tested this.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Parameter auth-client-required lets you configure authentication
methods. We tried to provide that in v2.9.0, but backed out due to
interface design doubts (commit 464444fcc1).
This commit is similar to what we backed out, but simpler: we use a
list of enumeration values instead of a list of objects with a member
of enumeration type.
Let's review our reasons for backing out the first try, as stated in
the commit message:
* The implementation uses deprecated rados_conf_set() key
"auth_supported". No biggie.
Fixed: we use "auth-client-required".
* The implementation makes -drive silently ignore invalid parameters
"auth" and "auth-supported.*.X" where X isn't "auth". Fixable (in
fact I'm going to fix similar bugs around parameter server), so
again no biggie.
That fix is commit 2836284db6. This commit doesn't bring the bugs
back.
* BlockdevOptionsRbd member @password-secret applies only to
authentication method cephx. Should it be a variant member of
RbdAuthMethod?
We've had time to ponder, and we decided to stick to the way Ceph
configuration works: the key configured separately, and silently
ignored if the authentication method doesn't use it.
* BlockdevOptionsRbd member @user could apply to both methods cephx
and none, but I'm not sure it's actually used with none. If it
isn't, should it be a variant member of RbdAuthMethod?
Likewise.
* The client offers a *set* of authentication methods, not a list.
Should the methods be optional members of BlockdevOptionsRbd instead
of members of list @auth-supported? The latter begs the question
what multiple entries for the same method mean. Trivial question
now that RbdAuthMethod contains nothing but @type, but less so when
RbdAuthMethod acquires other members, such the ones discussed above.
Again, we decided to stick to the way Ceph configuration works, except
we make auth-client-required a list of enumeration values instead of a
string containing keywords separated by delimiters.
* How BlockdevOptionsRbd member @auth-supported interacts with
settings from a configuration file specified with @conf is
undocumented. I suspect it's untested, too.
Not actually true, the documentation for @conf says "Values in the
configuration file will be overridden by options specified via QAPI",
and we've tested this.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This is needed, for example, to create a new bitmap and merge several
disabled bitmaps into a new one. Without this flag we will have to
put block-dirty-bitmap-add and block-dirty-bitmap-disable into one
transaction.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Message-id: 20180606182449.1607-6-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Message-id: 20180606182449.1607-5-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
Expose the ability to turn bitmaps "on" or "off". This is experimental
and principally for the sake of the Libvirt Checkpoints API, and it may
or may not be committed for 3.0.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Message-id: 20180606182449.1607-3-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
We're ready to declare the blockdev-create job stable. This renames the
corresponding QMP command from x-blockdev-create to blockdev-create.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
This changes the x-blockdev-create QMP command so that it doesn't block
the monitor and the main loop any more, but starts a background job that
performs the image creation.
The basic job as implemented here is all that is necessary to make image
creation asynchronous and to provide a QMP interface that can be marked
stable, but it still lacks a few features that jobs usually provide: The
job will ignore pause commands and it doesn't publish more than very
basic progress yet (total-progress is 1 and current-progress advances
from 0 to 1 when the driver callbacks returns). These features can be
added later without breaking compatibility.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
We're going to make the next release be 3.0, not 2.13; change
the annotations in our json appropriately.
Changes produced with
sed -i -e 's/2\.13/3.0/g' qapi/*.json
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-id: 20180522104000.9044-2-peter.maydell@linaro.org
This adds a separate schema file for all job-related definitions that
aren't tied to the block layer.
For a start, move the enums JobType, JobStatus and JobVerb.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
This moves BlockJob.status and the closely related functions
(block_)job_state_transition() and (block_)job_apply_verb to Job. The
two QAPI enums are renamed to JobStatus and JobVerb.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
QAPI types aren't externally visible, so we can rename them without
causing problems. Before we add a job type to Job, rename the enum
so it can be used for more than just block jobs.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Clarify that len is just an estimation of the end value of offset, and
that offset increases monotonically while len can change arbitrarily.
While touching the documentation of offset, move it directly after len
to match the order of the declaration below.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Commit 0ec4dfb8d changed block-job_pause/resume so that they return an
error if they don't do anything because the job is already
paused/running. It forgot to update the documentation, so do that now.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
This adds a simple copy-on-read filter driver. It relies on the already
existing COR functionality in the central block layer code, which may be
moved here once we no longer need it there.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20180421132929.21610-2-mreitz@redhat.com
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
When we've reached the concluded state, we need to expose the error
state if applicable. Add the new field.
This should be sufficient for determining if a job completed
successfully or not after concluding; if we want to discriminate
based on how it failed more mechanically, we can always add an
explicit return code enumeration later.
I didn't bother to make it only show up if we are in the concluded
state; I don't think it's necessary.
Cc: qemu-stable@nongnu.org
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
mincore(2) checks whether pages are resident. Use it to verify that
page cache has been dropped.
You can trigger a verification failure by mmapping the image file from
another process that loads a byte from a page, forcing it to become
resident. bdrv_co_invalidate_cache() will fail while that process is
alive.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Message-id: 20180427162312.18583-3-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
What static=on really does is what we call metadata preallocation for
other block drivers. While we can still change the QMP interface, make
it more consistent by using 'preallocation' for VDI, too.
This doesn't implement any new functionality, so the only supported
preallocation modes are 'off' and 'metadata' for now.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Set (and clear) histograms through new command
block-latency-histogram-set and show new statistics in
query-blockstats results.
For now, the command is marked experimental with prefix 'x-',
to gain experience with the interface without being stuck
with design decisions.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20180309165212.97144-3-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
[eblake: fix typos, mention x- prefix in commit message]
Signed-off-by: Eric Blake <eblake@redhat.com>
We have a clear replacement, so let's deprecate it.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-Id: <20180224154033.29559-8-mreitz@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
When doing drive mirror to a low speed shared storage, if there was heavy
BLK IO write workload in VM after the 'ready' event, drive mirror block job
can't be canceled immediately, it would keep running until the heavy BLK IO
workload stopped in the VM.
Libvirt depends on the current block-job-cancel semantics, which is that
when used without a flag after the 'ready' event, the command blocks
until data is in sync. However, these semantics are awkward in other
situations, for example, people may use drive mirror for realtime
backups while still wanting to use block live migration. Libvirt cannot
start a block live migration while another drive mirror is in progress,
but the user would rather abandon the backup attempt as broken and
proceed with the live migration than be stuck waiting for the current
drive mirror backup to finish.
The drive-mirror command already includes a 'force' flag, which libvirt
does not use, although it documented the flag as only being useful to
quit a job which is paused. However, since quitting a paused job has
the same effect as abandoning a backup in a non-paused job (namely, the
destination file is not in sync, and the command completes immediately),
we can just improve the documentation to make the force flag obviously
useful.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Jeff Cody <jcody@redhat.com>
Cc: Kevin Wolf <kwolf@redhat.com>
Cc: Max Reitz <mreitz@redhat.com>
Cc: Eric Blake <eblake@redhat.com>
Cc: John Snow <jsnow@redhat.com>
Reported-by: Huaitong Han <huanhuaitong@didichuxing.com>
Signed-off-by: Huaitong Han <huanhuaitong@didichuxing.com>
Signed-off-by: Liang Li <liliangleo@didichuxing.com>
Signed-off-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This adds the .bdrv_co_create driver callback to vpc, which
enables image creation over QMP.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
This adds the .bdrv_co_create driver callback to vhdx, which
enables image creation over QMP.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
This adds the .bdrv_co_create driver callback to qed, which
enables image creation over QMP.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
This adds the .bdrv_co_create driver callback to qcow, which
enables image creation over QMP.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
This adds the .bdrv_co_create driver callback to parallels, which
enables image creation over QMP.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
In preparation of QAPI-fying VDI image creation, we have to create a
BlockdevCreateOptionsVdi type which is received by a (future)
vdi_co_create().
vdi_co_create_opts() now converts the QemuOpts object into such a
BlockdevCreateOptionsVdi object. The protocol-layer file is still
created in vdi_co_do_create() (and BlockdevCreateOptionsVdi.file is set
to an empty string), but that will be addressed by a follow-up patch.
Note that cluster-size is not part of the QAPI schema because it is not
supported by default.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This adds the .bdrv_co_create driver callback to luks, which enables
image creation over QMP.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Expose the "manual" property via QAPI for the backup-related jobs.
As of this commit, this allows the management API to request the
"concluded" and "dismiss" semantics for backup jobs.
Signed-off-by: John Snow <jsnow@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Instead of automatically transitioning from PENDING to CONCLUDED, gate
the .prepare() and .commit() phases behind an explicit acknowledgement
provided by the QMP monitor if auto_finalize = false has been requested.
This allows us to perform graph changes in prepare and/or commit so that
graph changes do not occur autonomously without knowledge of the
controlling management layer.
Transactions that have reached the "PENDING" state together can all be
moved to invoke their finalization methods by issuing block_job_finalize
to any one job in the transaction.
Jobs in a transaction with mixed job->auto_finalize settings will all
remain stuck in the "PENDING" state, as if the entire transaction was
specified with auto_finalize = false. Jobs that specified
auto_finalize = true, however, will still not emit the PENDING event.
Signed-off-by: John Snow <jsnow@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
For jobs utilizing the new manual workflow, we intend to prohibit
them from modifying the block graph until the management layer provides
an explicit ACK via block-job-finalize to move the process forward.
To distinguish this runstate from "ready" or "waiting," we add a new
"pending" event and status.
For now, the transition from PENDING to CONCLUDED/ABORTING is automatic,
but a future commit will add the explicit block-job-finalize step.
Transitions:
Waiting -> Pending: Normal transition.
Pending -> Concluded: Normal transition.
Pending -> Aborting: Late transactional failures and cancellations.
Removed Transitions:
Waiting -> Concluded: Jobs must go to PENDING first.
Verbs:
Cancel: Can be applied to a pending job.
+---------+
|UNDEFINED|
+--+------+
|
+--v----+
+---------+CREATED+-----------------+
| +--+----+ |
| | |
| +--+----+ +------+ |
+---------+RUNNING<----->PAUSED| |
| +--+-+--+ +------+ |
| | | |
| | +------------------+ |
| | | |
| +--v--+ +-------+ | |
+---------+READY<------->STANDBY| | |
| +--+--+ +-------+ | |
| | | |
| +--v----+ | |
+---------+WAITING<---------------+ |
| +--+----+ |
| | |
| +--v----+ |
+---------+PENDING| |
| +--+----+ |
| | |
+--v-----+ +--v------+ |
|ABORTING+--->CONCLUDED| |
+--------+ +--+------+ |
| |
+--v-+ |
|NULL<--------------------+
+----+
Signed-off-by: John Snow <jsnow@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
For jobs that are stuck waiting on others in a transaction, it would
be nice to know that they are no longer "running" in that sense, but
instead are waiting on other jobs in the transaction.
Jobs that are "waiting" in this sense cannot be meaningfully altered
any longer as they have left their running loop. The only meaningful
user verb for jobs in this state is "cancel," which will cancel the
whole transaction, too.
Transitions:
Running -> Waiting: Normal transition.
Ready -> Waiting: Normal transition.
Waiting -> Aborting: Transactional cancellation.
Waiting -> Concluded: Normal transition.
Removed Transitions:
Running -> Concluded: Jobs must go to WAITING first.
Ready -> Concluded: Jobs must go to WAITING first.
Verbs:
Cancel: Can be applied to WAITING jobs.
+---------+
|UNDEFINED|
+--+------+
|
+--v----+
+---------+CREATED+-----------------+
| +--+----+ |
| | |
| +--v----+ +------+ |
+---------+RUNNING<----->PAUSED| |
| +--+-+--+ +------+ |
| | | |
| | +------------------+ |
| | | |
| +--v--+ +-------+ | |
+---------+READY<------->STANDBY| | |
| +--+--+ +-------+ | |
| | | |
| +--v----+ | |
+---------+WAITING<---------------+ |
| +--+----+ |
| | |
+--v-----+ +--v------+ |
|ABORTING+--->CONCLUDED| |
+--------+ +--+------+ |
| |
+--v-+ |
|NULL<--------------------+
+----+
Signed-off-by: John Snow <jsnow@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
For jobs that have reached their CONCLUDED state, prior to having their
last reference put down (meaning jobs that have completed successfully,
unsuccessfully, or have been canceled), allow the user to dismiss the
job's lingering status report via block-job-dismiss.
This gives management APIs the chance to conclusively determine if a job
failed or succeeded, even if the event broadcast was missed.
Note: block_job_do_dismiss and block_job_decommission happen to do
exactly the same thing, but they're called from different semantic
contexts, so both aliases are kept to improve readability.
Note 2: Don't worry about the 0x04 flag definition for AUTO_DISMISS, she
has a friend coming in a future patch to fill the hole where 0x02 is.
Verbs:
Dismiss: operates on CONCLUDED jobs only.
Signed-off-by: John Snow <jsnow@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Add a new state that specifically demarcates when we begin to permanently
demolish a job after it has performed all work. This makes the transition
explicit in the STM table and highlights conditions under which a job may
be demolished.
Alongside this state, add a new helper command "block_job_decommission",
which transitions to the NULL state and puts down our implicit reference.
This separates instances in the code for "block_job_unref" which merely
undo a matching "block_job_ref" with instances intended to initiate the
full destruction of the object.
This decommission action also sets a number of fields to make sure that
block internals or external users that are holding a reference to a job
to see when it "finishes" are convinced that the job object is "done."
This is necessary, for instance, to do a block_job_cancel_sync on a
created object which will not make any progress.
Now, all jobs must go through block_job_decommission prior to being
freed, giving us start-to-finish state machine coverage for jobs.
Transitions:
Created -> Null: Early failure event before the job is started
Concluded -> Null: Standard transition.
Verbs:
None. This should not ever be visible to the monitor.
+---------+
|UNDEFINED|
+--+------+
|
+--v----+
+---------+CREATED+------------------+
| +--+----+ |
| | |
| +--v----+ +------+ |
+---------+RUNNING<----->PAUSED| |
| +--+-+--+ +------+ |
| | | |
| | +------------------+ |
| | | |
| +--v--+ +-------+ | |
+---------+READY<------->STANDBY| | |
| +--+--+ +-------+ | |
| | | |
+--v-----+ +--v------+ | |
|ABORTING+--->CONCLUDED<-------------+ |
+--------+ +--+------+ |
| |
+--v-+ |
|NULL<---------------------+
+----+
Signed-off-by: John Snow <jsnow@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
add a new state "CONCLUDED" that identifies a job that has ceased all
operations. The wording was chosen to avoid any phrasing that might
imply success, error, or cancellation. The task has simply ceased all
operation and can never again perform any work.
("finished", "done", and "completed" might all imply success.)
Transitions:
Running -> Concluded: normal completion
Ready -> Concluded: normal completion
Aborting -> Concluded: error and cancellations
Verbs:
None as of this commit. (a future commit adds 'dismiss')
+---------+
|UNDEFINED|
+--+------+
|
+--v----+
+---------+CREATED|
| +--+----+
| |
| +--v----+ +------+
+---------+RUNNING<----->PAUSED|
| +--+-+--+ +------+
| | |
| | +------------------+
| | |
| +--v--+ +-------+ |
+---------+READY<------->STANDBY| |
| +--+--+ +-------+ |
| | |
+--v-----+ +--v------+ |
|ABORTING+--->CONCLUDED<-------------+
+--------+ +---------+
Signed-off-by: John Snow <jsnow@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Add a new state ABORTING.
This makes transitions from normative states to error states explicit
in the STM, and serves as a disambiguation for which states may complete
normally when normal end-states (CONCLUDED) are added in future commits.
Notably, Paused/Standby jobs do not transition directly to aborting,
as they must wake up first and cooperate in their cancellation.
Transitions:
Created -> Aborting: can be cancelled (by the system)
Running -> Aborting: can be cancelled or encounter an error
Ready -> Aborting: can be cancelled or encounter an error
Verbs:
None. The job must finish cleaning itself up and report its final status.
+---------+
|UNDEFINED|
+--+------+
|
+--v----+
+---------+CREATED|
| +--+----+
| |
| +--v----+ +------+
+---------+RUNNING<----->PAUSED|
| +--+----+ +------+
| |
| +--v--+ +-------+
+---------+READY<------->STANDBY|
| +-----+ +-------+
|
+--v-----+
|ABORTING|
+--------+
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Which commands ("verbs") are appropriate for jobs in which state is
also somewhat burdensome to keep track of.
As of this commit, it looks rather useless, but begins to look more
interesting the more states we add to the STM table.
A recurring theme is that no verb will apply to an 'undefined' job.
Further, it's not presently possible to restrict the "pause" or "resume"
verbs any more than they are in this commit because of the asynchronous
nature of how jobs enter the PAUSED state; justifications for some
seemingly erroneous applications are given below.
=====
Verbs
=====
Cancel: Any state except undefined.
Pause: Any state except undefined;
'created': Requests that the job pauses as it starts.
'running': Normal usage. (PAUSED)
'paused': The job may be paused for internal reasons,
but the user may wish to force an indefinite
user-pause, so this is allowed.
'ready': Normal usage. (STANDBY)
'standby': Same logic as above.
Resume: Any state except undefined;
'created': Will lift a user's pause-on-start request.
'running': Will lift a pause request before it takes effect.
'paused': Normal usage.
'ready': Will lift a pause request before it takes effect.
'standby': Normal usage.
Set-speed: Any state except undefined, though ready may not be meaningful.
Complete: Only a 'ready' job may accept a complete request.
=======
Changes
=======
(1)
To facilitate "nice" error checking, all five major block-job verb
interfaces in blockjob.c now support an errp parameter:
- block_job_user_cancel is added as a new interface.
- block_job_user_pause gains an errp paramter
- block_job_user_resume gains an errp parameter
- block_job_set_speed already had an errp parameter.
- block_job_complete already had an errp parameter.
(2)
block-job-pause and block-job-resume will no longer no-op when trying
to pause an already paused job, or trying to resume a job that isn't
paused. These functions will now report that they did not perform the
action requested because it was not possible.
iotests have been adjusted to address this new behavior.
(3)
block-job-complete doesn't worry about checking !block_job_started,
because the permission table guards against this.
(4)
test-bdrv-drain's job implementation needs to announce that it is
'ready' now, in order to be completed.
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We're about to add several new states, and booleans are becoming
unwieldly and difficult to reason about. It would help to have a
more explicit bookkeeping of the state of blockjobs. To this end,
add a new "status" field and add our existing states in a redundant
manner alongside the bools they are replacing:
UNDEFINED: Placeholder, default state. Not currently visible to QMP
unless changes occur in the future to allow creating jobs
without starting them via QMP.
CREATED: replaces !!job->co && paused && !busy
RUNNING: replaces effectively (!paused && busy)
PAUSED: Nearly redundant with info->paused, which shows pause_count.
This reports the actual status of the job, which almost always
matches the paused request status. It differs in that it is
strictly only true when the job has actually gone dormant.
READY: replaces job->ready.
STANDBY: Paused, but job->ready is true.
New state additions in coming commits will not be quite so redundant:
WAITING: Waiting on transaction. This job has finished all the work
it can until the transaction converges, fails, or is canceled.
PENDING: Pending authorization from user. This job has finished all the
work it can until the job or transaction is finalized via
block_job_finalize. This implies the transaction has converged
and left the WAITING phase.
ABORTING: Job has encountered an error condition and is in the process
of aborting.
CONCLUDED: Job has ceased all operations and has a return code available
for query and may be dismissed via block_job_dismiss.
NULL: Job has been dismissed and (should) be destroyed. Should never
be visible to QMP.
Some of these states appear somewhat superfluous, but it helps define the
expected flow of a job; so some of the states wind up being synchronous
empty transitions. Importantly, jobs can be in only one of these states
at any given time, which helps code and external users alike reason about
the current condition of a job unambiguously.
Signed-off-by: John Snow <jsnow@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Add special state, when qmp operations on the bitmap are disabled.
It is needed during bitmap migration. "Frozen" state is not
appropriate here, because it looks like bitmap is unchanged.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 20180207155837.92351-5-vsementsov@virtuozzo.com
Signed-off-by: John Snow <jsnow@redhat.com>
