Commit Graph

157 Commits

Author SHA1 Message Date
John Snow
22dffcbec6 block/commit: refactor commit to use job callbacks
Use the component callbacks; prepare, abort, and clean.

NB: prepare is only called when the job has not yet failed;
and abort can be called after prepare.

complete -> prepare -> abort -> clean
complete -> abort -> clean

During refactor, a potential problem with bdrv_drop_intermediate
was identified, the patched behavior is no worse than the pre-patch
behavior, so leave a FIXME for now to be fixed in a future patch.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20180906130225.5118-5-jsnow@redhat.com
Reviewed-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-09-25 15:31:15 +02:00
John Snow
5360782d08 block/commit: add block job creation flags
Add support for taking and passing forward job creation flags.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Message-id: 20180906130225.5118-2-jsnow@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-09-25 15:31:15 +02:00
John Snow
f369b48dc4 block/commit: utilize job_exit shim
Change the manual deferment to commit_complete into the implicit
callback to job_exit, renaming commit_complete to commit_exit.

This conversion does change the timing of when job_completed is
called to after the bdrv_replace_node and bdrv_unref calls, which
could have implications for bjob->blk which will now be put down
after this cleanup.

Kevin highlights that we did not take any permissions for that backend
at job creation time, so it is safe to reorder these operations.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20180830015734.19765-5-jsnow@redhat.com
Reviewed-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-08-31 16:28:33 +02:00
John Snow
3d1f8b07a4 jobs: canonize Error object
Jobs presently use both an Error object in the case of the create job,
and char strings in the case of generic errors elsewhere.

Unify the two paths as just j->err, and remove the extra argument from
job_completed. The integer error code for job_completed is kept for now,
to be removed shortly in a separate patch.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 20180830015734.19765-3-jsnow@redhat.com
[mreitz: Dropped a superfluous g_strdup()]
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-08-31 16:28:33 +02:00
John Snow
f67432a201 jobs: change start callback to run callback
Presently we codify the entry point for a job as the "start" callback,
but a more apt name would be "run" to clarify the idea that when this
function returns we consider the job to have "finished," except for
any cleanup which occurs in separate callbacks later.

As part of this clarification, change the signature to include an error
object and a return code. The error ptr is not yet used, and the return
code while captured, will be overwritten by actions in the job_completed
function.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20180830015734.19765-2-jsnow@redhat.com
Reviewed-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-08-31 16:28:33 +02:00
Vladimir Sementsov-Ogievskiy
f66b1f0e27 block: drop empty .bdrv_close handlers
.bdrv_close handler is optional after previous commit, no needs to keep
empty functions more.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-08-15 12:50:39 +02:00
Kevin Wolf
1266c9b9f5 job: Add error message for failing jobs
So far we relied on job->ret and strerror() to produce an error message
for failed jobs. Not surprisingly, this tends to result in completely
useless messages.

This adds a Job.error field that can contain an error string for a
failing job, and a parameter to job_completed() that sets the field. As
a default, if NULL is passed, we continue to use strerror(job->ret).

All existing callers are changed to pass NULL. They can be improved in
separate patches.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
2018-05-30 13:31:01 +02:00
Kevin Wolf
30a5c887bf job: Move progress fields to Job
BlockJob has fields .offset and .len, which are actually misnomers today
because they are no longer tied to block device sizes, but just progress
counters. As such they make a lot of sense in generic Jobs.

This patch moves the fields to Job and renames them to .progress_current
and .progress_total to describe their function better.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2018-05-23 14:30:51 +02:00
Kevin Wolf
3d70ff53b6 job: Move completion and cancellation to Job
This moves the top-level job completion and cancellation functions from
BlockJob to Job.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-05-23 14:30:51 +02:00
Kevin Wolf
6a74c075ac job: Move job_finish_sync() to Job
block_job_finish_sync() doesn't contain anything block job specific any
more, so it can be moved to Job.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2018-05-23 14:30:50 +02:00
Kevin Wolf
b69f777dd9 job: Add job_drain()
block_job_drain() contains a blk_drain() call which cannot be moved to
Job, so add a new JobDriver callback JobDriver.drain which has a common
implementation for all BlockJobs. In addition to this we keep the
existing BlockJobDriver.drain callback that is called by the common
drain implementation for all block jobs.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2018-05-23 14:30:50 +02:00
Kevin Wolf
4ad351819b job: Move single job finalisation to Job
This moves the finalisation of a single job from BlockJob to Job.

Some part of this code depends on job transactions, and job transactions
call this code, we introduce some temporary calls from Job functions to
BlockJob ones. This will be fixed once transactions move to Job, too.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2018-05-23 14:30:50 +02:00
Kevin Wolf
bb02b65c7d job: Move BlockJobCreateFlags to Job
This renames the BlockJobCreateFlags constants, moves a few JOB_INTERNAL
checks to job_create() and the auto_{finalize,dismiss} fields from
BlockJob to Job.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2018-05-23 14:30:50 +02:00
Kevin Wolf
b15de82867 job: Move pause/resume functions to Job
While we already moved the state related to job pausing to Job, the
functions to do were still BlockJob only. This commit moves them over to
Job.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
2018-05-23 14:30:50 +02:00
Kevin Wolf
5d43e86e11 job: Add job_sleep_ns()
There is nothing block layer specific about block_job_sleep_ns(), so
move the function to Job.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2018-05-23 14:30:50 +02:00
Kevin Wolf
da01ff7f38 job: Move coroutine and related code to Job
This commit moves some core functions for dealing with the job coroutine
from BlockJob to Job. This includes primarily entering the coroutine
(both for the first and reentering) and yielding explicitly and at pause
points.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
2018-05-23 14:30:50 +02:00
Kevin Wolf
1908a5590c job: Move defer_to_main_loop to Job
Move the defer_to_main_loop functionality from BlockJob to Job.

The code can be simplified because we can use job->aio_context in
job_defer_to_main_loop_bh() now, instead of having to access the
BlockDriverState.

Probably taking the data->aio_context lock in addition was already
unnecessary in the old code because we didn't actually make use of
anything protected by the old AioContext except getting the new
AioContext, in case it changed between scheduling the BH and running it.
But it's certainly unnecessary now that the BDS isn't accessed at all
any more.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
2018-05-23 14:30:50 +02:00
Kevin Wolf
daa7f2f946 job: Move cancelled to Job
We cannot yet move the whole logic around job cancelling to Job because
it depends on quite a few other things that are still only in BlockJob,
but we can move the cancelled field at least.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
2018-05-23 14:30:49 +02:00
Kevin Wolf
80fa2c756b job: Add reference counting
This moves reference counting from BlockJob to Job.

In order to keep calling the BlockJob cleanup code when the job is
deleted via job_unref(), introduce a new JobDriver.free callback. Every
block job must use block_job_free() for this callback, this is asserted
in block_job_create().

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
2018-05-23 14:30:49 +02:00
Kevin Wolf
252291eaea job: Add JobDriver.job_type
This moves the job_type field from BlockJobDriver to JobDriver.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
2018-05-23 14:30:49 +02:00
Kevin Wolf
8e4c87000f job: Rename BlockJobType into JobType
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>
2018-05-23 14:30:49 +02:00
Kevin Wolf
33e9e9bd62 job: Create Job, JobDriver and job_create()
This is the first step towards creating an infrastructure for generic
background jobs that aren't tied to a block device. For now, Job only
stores its ID and JobDriver, the rest stays in BlockJob.

The following patches will move over more parts of BlockJob to Job if
they are meaningful outside the context of a block job.

BlockJob.driver is now redundant, but this patch leaves it around to
avoid unnecessary churn. The next patches will get rid of almost all of
its uses anyway so that it can be removed later with much less churn.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
2018-05-23 14:30:49 +02:00
Kevin Wolf
dee81d5111 blockjob: Introduce block_job_ratelimit_get_delay()
This gets us rid of more direct accesses to BlockJob fields from the
job drivers.

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>
2018-05-15 16:11:50 +02:00
Kevin Wolf
18bb69287e blockjob: Implement block_job_set_speed() centrally
All block job drivers support .set_speed and all of them duplicate the
same code to implement it. Move that code to blockjob.c and remove the
now useless callback.

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>
2018-05-15 16:11:50 +02:00
Kevin Wolf
f05fee508f blockjob: Move RateLimit to BlockJob
Every block job has a RateLimit, and they all do the exact same thing
with it, so it should be common infrastructure. Move the struct field
for a start.

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>
2018-05-15 16:11:50 +02:00
Kevin Wolf
05df8a6a2b blockjob: Wrappers for progress counter access
Block job drivers are not expected to mess with the internals of the
BlockJob object, so provide wrapper functions for one of the cases where
they still do it: Updating the progress counter.

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>
2018-05-15 16:11:49 +02:00
Kevin Wolf
2fe4bba19b commit/stream: Reset delay_ns
Streaming and the commit block job only want to apply throttling when
they actually copied data instead of skipping it, so they made the
calculation of delay_ns conditional. However, delay_ns isn't reset when
skipping some sectors, so instead of not waiting, the old delay is
applied again.

Properly reset delay_ns where needed.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2018-04-10 16:33:47 +02:00
John Snow
75859b9420 blockjobs: model single jobs as transactions
model all independent jobs as single job transactions.

It's one less case we have to worry about when we add more states to the
transition machine. This way, we can just treat all job lifetimes exactly
the same. This helps tighten assertions of the STM graph and removes some
conditionals that would have been needed in the coming commits adding a
more explicit job lifetime management API.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-03-19 12:01:24 +01:00
Eric Blake
3e4d0e72b7 block: Switch passthrough drivers to .bdrv_co_block_status()
We are gradually moving away from sector-based interfaces, towards
byte-based.  Update the generic helpers, and all passthrough clients
(blkdebug, commit, mirror, throttle) accordingly.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-03-02 18:39:07 +01:00
Kevin Wolf
44487eb973 commit: Simplify reopen of base
Since commit bde70715, base is the only node that is reopened in
commit_start(). This means that the code, which still involves an
explicit BlockReopenQueue, can now be simplified by using bdrv_reopen().

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
2017-12-22 15:05:32 +01:00
Paolo Bonzini
5bf1d5a73a blockjob: remove clock argument from block_job_sleep_ns
All callers are using QEMU_CLOCK_REALTIME, and it will not be possible to
support more than one clock when block_job_sleep_ns switches to a single
timer stored in the BlockJob struct.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Tested-By: Jeff Cody <jcody@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-11-29 15:11:02 +01:00
Kevin Wolf
bde70715b6 commit: Remove overlay_bs
We don't need to make any assumptions about the graph layout above the
top node of the commit operation any more. Remove the use of
bdrv_find_overlay() and related variables from the commit job code.

bdrv_drop_intermediate() doesn't use the 'active' parameter any more, so
we can just drop it.

The overlay node was previously added to the block job to get a
BLK_PERM_GRAPH_MOD. We really need to respect those permissions in
bdrv_drop_intermediate() now, but as long as we haven't figured out yet
how BLK_PERM_GRAPH_MOD is actually supposed to work, just leave a TODO
comment there.

With this change, it is now possible to perform another block job on an
overlay node without conflicts. qemu-iotests 030 is changed accordingly.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2017-10-06 16:28:58 +02:00
Kevin Wolf
61f09cea01 commit: Support multiple roots above top node
This changes the commit block job to support operation in a graph where
there is more than a single active layer that references the top node.

This involves inserting the commit filter node not only on the path
between the given active node and the top node, but between the top node
and all of its parents.

On completion, bdrv_drop_intermediate() must consider all parents for
updating the backing file link. These parents may be backing files
themselves and as such read-only; reopen them temporarily if necessary.
Previously this was achieved by the bdrv_reopen() calls in the commit
block job that made overlay_bs read-write for the whole duration of the
block job, even though write access is only needed on completion.

Now that we consider all parents, overlay_bs is meaningless. It is left
in place in this commit, but we'll remove it soon.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-10-06 16:28:58 +02:00
Kevin Wolf
e0995dc3da block: Add reopen_queue to bdrv_child_perm()
In the context of bdrv_reopen(), we'll have to look at the state of the
graph as it will be after the reopen. This interface addition is in
preparation for the change.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2017-09-26 14:46:23 +02:00
Manos Pitsidianakis
f7cc69b326 block: add default implementations for bdrv_co_get_block_status()
bdrv_co_get_block_status_from_file() and
bdrv_co_get_block_status_from_backing() set *file to bs->file and
bs->backing respectively, so that bdrv_co_get_block_status() can recurse
to them. Future block drivers won't have to duplicate code to implement
this.

Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Manos Pitsidianakis <el13635@mail.ntua.gr>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-09-04 18:31:13 +02:00
Kevin Wolf
d3c8c67469 block: Skip implicit nodes in query-block/blockstats
Commits 0db832f and 6cdbceb introduced the automatic insertion of filter
nodes above the top layer of mirror and commit block jobs. The
assumption made there was that since libvirt doesn't do node-level
management of the block layer yet, it shouldn't be affected by added
nodes.

This is true as far as commands issued by libvirt are concerned. It only
uses BlockBackend names to address nodes, so any operations it performs
still operate on the root of the tree as intended.

However, the assumption breaks down when you consider query commands,
which return data for the wrong node now. These commands also return
information on some child nodes (bs->file and/or bs->backing), which
libvirt does make use of, and which refer to the wrong nodes, too.

One of the consequences is that oVirt gets wrong information about the
image size and stops the VM in response as long as a mirror or commit
job is running:

https://bugzilla.redhat.com/show_bug.cgi?id=1470634

This patch fixes the problem by hiding the implicit nodes created
automatically by the mirror and commit block jobs in the output of
query-block and BlockBackend-based query-blockstats as long as the user
doesn't indicate that they are aware of those nodes by providing a node
name for them in the QMP command to start the block job.

The node-based commands query-named-block-nodes and query-blockstats
with query-nodes=true still show all nodes, including implicit ones.
This ensures that users that are capable of node-level management can
still access the full information; users that only know BlockBackends
won't use these commands.

Cc: qemu-stable@nongnu.org
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Tested-by: Eric Blake <eblake@redhat.com>
2017-07-24 15:06:04 +02:00
Kevin Wolf
b1e1fa0c3a commit: Add NULL check for overlay_bs
I can't see how overlay_bs could become NULL with the current code, but
other code in this function already checks it and we can make Coverity
happy with this check, so let's add it.

Cc: qemu-stable@nongnu.org
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-07-18 15:14:35 +02:00
Max Reitz
3a691c50f1 block: Add PreallocMode to blk_truncate()
blk_truncate() itself will pass that value to bdrv_truncate(), and all
callers of blk_truncate() just set the parameter to PREALLOC_MODE_OFF
for now.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20170613202107.10125-4-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-07-11 17:45:01 +02:00
Eric Blake
51b0a48888 block: Make bdrv_is_allocated_above() byte-based
We are gradually moving away from sector-based interfaces, towards
byte-based.  In the common case, allocation is unlikely to ever use
values that are not naturally sector-aligned, but it is possible
that byte-based values will let us be more precise about allocation
at the end of an unaligned file that can do byte-based access.

Changing the signature of the function to use int64_t *pnum ensures
that the compiler enforces that all callers are updated.  For now,
the io.c layer still assert()s that all callers are sector-aligned,
but that can be relaxed when a later patch implements byte-based
block status.  Therefore, for the most part this patch is just the
addition of scaling at the callers followed by inverse scaling at
bdrv_is_allocated().  But some code, particularly stream_run(),
gets a lot simpler because it no longer has to mess with sectors.
Leave comments where we can further simplify by switching to
byte-based iterations, once later patches eliminate the need for
sector-aligned operations.

For ease of review, bdrv_is_allocated() was tackled separately.

Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-07-10 13:18:07 +02:00
Eric Blake
d6a644bbfe block: Make bdrv_is_allocated() byte-based
We are gradually moving away from sector-based interfaces, towards
byte-based.  In the common case, allocation is unlikely to ever use
values that are not naturally sector-aligned, but it is possible
that byte-based values will let us be more precise about allocation
at the end of an unaligned file that can do byte-based access.

Changing the signature of the function to use int64_t *pnum ensures
that the compiler enforces that all callers are updated.  For now,
the io.c layer still assert()s that all callers are sector-aligned
on input and that *pnum is sector-aligned on return to the caller,
but that can be relaxed when a later patch implements byte-based
block status.  Therefore, this code adds usages like
DIV_ROUND_UP(,BDRV_SECTOR_SIZE) to callers that still want aligned
values, where the call might reasonbly give non-aligned results
in the future; on the other hand, no rounding is needed for callers
that should just continue to work with byte alignment.

For the most part this patch is just the addition of scaling at the
callers followed by inverse scaling at bdrv_is_allocated().  But
some code, particularly bdrv_commit(), gets a lot simpler because it
no longer has to mess with sectors; also, it is now possible to pass
NULL if the caller does not care how much of the image is allocated
beyond the initial offset.  Leave comments where we can further
simplify once a later patch eliminates the need for sector-aligned
requests through bdrv_is_allocated().

For ease of review, bdrv_is_allocated_above() will be tackled
separately.

Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-07-10 13:18:07 +02:00
Eric Blake
317a6676a2 commit: Switch commit_run() to byte-based
We are gradually converting to byte-based interfaces, as they are
easier to reason about than sector-based.  Change the internal
loop iteration of committing to track by bytes instead of sectors
(although we are still guaranteed that we iterate by steps that
are sector-aligned).

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-07-10 13:18:06 +02:00
Eric Blake
d8a9858408 commit: Switch commit_populate() to byte-based
We are gradually converting to byte-based interfaces, as they are
easier to reason about than sector-based.  Start by converting an
internal function (no semantic change).

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-07-10 13:18:06 +02:00
Eric Blake
5cb1a49e01 trace: Show blockjob actions via bytes, not sectors
Upcoming patches are going to switch to byte-based interfaces
instead of sector-based.  Even worse, trace_backup_do_cow_enter()
had a weird mix of cluster and sector indices.

The trace interface is low enough that there are no stability
guarantees, and therefore nothing wrong with changing our units,
even in cases like trace_backup_do_cow_skip() where we are not
changing the trace output.  So make the tracing uniformly use
bytes.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-07-10 13:18:06 +02:00
Eric Blake
f3e4ce4af3 blockjob: Track job ratelimits via bytes, not sectors
The user interface specifies job rate limits in bytes/second.
It's pointless to have our internal representation track things
in sectors/second, particularly since we want to move away from
sector-based interfaces.

Fix up a doc typo found while verifying that the ratelimit
code handles the scaling difference.

Repetition of expressions like 'n * BDRV_SECTOR_SIZE' will be
cleaned up later when functions are converted to iterate over
images by bytes rather than by sectors.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-07-10 13:18:06 +02:00
Eric Blake
d5254033da block: Simplify use of BDRV_BLOCK_RAW
The lone caller that cares about a return of BDRV_BLOCK_RAW
(namely, io.c:bdrv_co_get_block_status) completely replaces the
return value, so there is no point in passing BDRV_BLOCK_DATA.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-07-10 13:18:05 +02:00
Kevin Wolf
4f78a16fee commit: Fix completion with extra reference
commit_complete() can't assume that after its block_job_completed() the
job is actually immediately freed; someone else may still be holding
references. In this case, the op blockers on the intermediate nodes make
the graph reconfiguration in the completion code fail.

Call block_job_remove_all_bdrv() manually so that we know for sure that
any blockers on intermediate nodes are given up.

Cc: qemu-stable@nongnu.org
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2017-06-26 14:51:12 +02:00
Kevin Wolf
19ebd13ed4 commit: Fix use after free in completion
The final bdrv_set_backing_hd() could be working on already freed nodes
because the commit job drops its references (through BlockBackends) to
both overlay_bs and top already a bit earlier.

One way to trigger the bug is hot unplugging a disk for which
blockdev_mark_auto_del() cancels the block job.

Fix this by taking BDS-level references while we're still using the
nodes.

Cc: qemu-stable@nongnu.org
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
2017-06-09 13:46:13 +02:00
Paolo Bonzini
05b0d8e3b8 blockjob: introduce block_job_early_fail
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>
2017-05-24 16:38:51 -04:00
Max Reitz
ed3d2ec98a block: Add errp to b{lk,drv}_truncate()
For one thing, this allows us to drop the error message generation from
qemu-img.c and blockdev.c and instead have it unified in
bdrv_truncate().

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20170328205129.15138-3-mreitz@redhat.com
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-04-28 16:02:02 +02:00
Kevin Wolf
0d0676a104 commit: Set commit_top_bs->total_sectors
Like in the mirror filter driver, we also need to set the image size for
the commit filter driver. This is less likely to be a problem in
practice than for the mirror because we're not at the active layer here,
but attaching new parents to a node in the middle of the chain is
possible, so the size needs to be correct anyway.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
2017-04-07 14:44:05 +02:00
Kevin Wolf
02be4aeb93 commit: Set commit_top_bs->aio_context
The filter driver that is inserted by the commit job needs to use the
same AioContext as its parent and child nodes.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
2017-04-07 14:44:05 +02:00
Kevin Wolf
dcbf37ce41 commit: Implement .bdrv_refresh_filename
We want query-block to return the right filename, even if a commit job
put a bdrv_commit_top on top of the actual image format driver. Let
bdrv_commit_top.bdrv_refresh_filename get the filename from its backing
file.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2017-03-13 12:49:33 +01:00
Kevin Wolf
9196565866 commit: Implement bdrv_commit_top.bdrv_co_get_block_status
In some cases, bdrv_co_get_block_status() is called recursively for the
whole backing chain. The automatically inserted bdrv_commit_top filter
driver must not stop the recursion, so implement a callback that simply
forwards the request to bs->backing.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2017-03-13 12:49:33 +01:00
Fam Zheng
b69f00dde4 commit: Don't use error_abort in commit_start
bdrv_set_backing_hd failure needn't be abort. Since we already have
error parameter, use it.

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-03-07 14:53:29 +01:00
Kevin Wolf
b247767aac commit: Fix error handling
Apparently some kind of mismerge happened in commit 8dfba279, which
broke the error handling without any real reason by removing the
assignment of the return value to ret in a blk_insert_bs() call.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
2017-03-07 14:53:28 +01:00
Kevin Wolf
12fa4af61f block: Add Error parameter to bdrv_set_backing_hd()
Not all callers of bdrv_set_backing_hd() know for sure that attaching
the backing file will be allowed by the permission system. Return the
error from the function rather than aborting.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2017-02-28 20:47:51 +01:00
Kevin Wolf
0db832f42e commit: Add filter-node-name to block-commit
Management tools need to be able to know about every node in the graph
and need a way to address them. Changing the graph structure was okay
because libvirt doesn't really manage the node level yet, but future
libvirt versions need to deal with both new and old version of qemu.

This new option to blockdev-commit allows the client to set a node-name
for the automatically inserted filter driver, and at the same time
serves as a witness for a future libvirt that this version of qemu does
automatically insert a filter driver.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2017-02-28 20:47:50 +01:00
Kevin Wolf
d3f0675922 commit: Use real permissions for HMP 'commit'
This is a little simpler than the commit block job because it's
synchronous and only commits into the immediate backing file, but
otherwise doing more or less the same.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
2017-02-28 20:40:37 +01:00
Kevin Wolf
8dfba27977 commit: Use real permissions in commit block job
This is probably one of the most interesting conversions to the new
op blocker system because a commit block job intentionally leaves some
intermediate block nodes in the backing chain that aren't valid on their
own any more; only the whole chain together results in a valid view.

In order to provide the 'consistent read' permission to the parents of
the 'top' node of the commit job, a new filter block driver is inserted
above 'top' which doesn't require 'consistent read' on its backing
chain. Subsequently, the commit job can block 'consistent read' on all
intermediate nodes without causing a conflict.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2017-02-28 20:40:37 +01:00
Kevin Wolf
76d554e20b blockjob: Add permissions to block_job_add_bdrv()
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>
2017-02-28 20:40:37 +01:00
Kevin Wolf
c6cc12bfa7 blockjob: Add permissions to block_job_create()
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>
2017-02-28 20:40:37 +01:00
Kevin Wolf
d7086422b1 block: Add error parameter to blk_insert_bs()
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>
2017-02-28 20:40:36 +01:00
Kevin Wolf
6d0eb64d5c block: Add permissions to blk_new()
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>
2017-02-28 20:40:36 +01:00
John Snow
5ccac6f186 blockjob: add block_job_start
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>
2016-11-14 22:47:34 -05:00
John Snow
a7815a764c blockjob: add .start field
Add an explicit start field to specify the entrypoint. We already have
ownership of the coroutine itself AND managing the lifetime of the
coroutine, let's take control of creation of the coroutine, too.

This will allow us to delay creation of the actual coroutine until we
know we'll actually start a BlockJob in block_job_start. This avoids
the sticky question of how to "un-create" a Coroutine that hasn't been
started yet.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-id: 1478587839-9834-4-git-send-email-jsnow@redhat.com
Signed-off-by: Jeff Cody <jcody@redhat.com>
2016-11-14 22:47:34 -05:00
John Snow
c87621ea68 blockjobs: split interface into public/private, Part 1
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>
2016-11-01 08:04:56 -04:00
John Snow
8254b6d953 blockjob: centralize QMP event emissions
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>
2016-11-01 07:55:57 -04:00
John Snow
f81e0b4532 blockjobs: Allow creating internal jobs
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>
2016-11-01 07:55:57 -04:00
Alberto Garcia
3e4c5122cb block: Block all nodes involved in the block-commit operation
After a successful block-commit operation all nodes between top and
base are removed from the backing chain, and top's overlay needs to
be updated to point to base. Because of that we should prevent other
block jobs from messing with them.

This patch blocks all operations in these nodes in commit_start().

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-10-31 16:52:38 +01:00
Paolo Bonzini
720150f318 block: prepare bdrv_reopen_multiple to release AioContext
After the next patch bdrv_drain_all will have to be called without holding any
AioContext.  Prepare to do this by adding an AioContext argument to
bdrv_reopen_multiple.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1477565348-5458-15-git-send-email-pbonzini@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
2016-10-28 21:50:18 +08:00
Alberto Garcia
0fe282bb4b commit: Add 'base' to the reopen queue before 'overlay_bs'
Now that we're checking for duplicates in the reopen queue, there's no
need to force a specific order in which the queue is constructed so we
can revert 3db2bd5508.

Since both ways of constructing the queue are now valid, this patch
doesn't have any effect on the behavior of QEMU and is not strictly
necessary. However it can help us check that the fix for the reopen
queue is robust: if it stops working properly at some point, iotest
040 will break.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-09-23 13:36:10 +02:00
Alberto Garcia
4d6f8cbba7 commit: get the overlay node before manipulating the backing chain
The 'block-commit' command has a 'top' parameter to specify the
topmost node from which the data is going to be copied.

   [E] <- [D] <- [C] <- [B] <- [A]

In this case if [C] is the top node then this is the result:

   [E] <- [B] <- [A]

[B] must be modified so its backing image string points to [E] instead
of [C]. commit_start() takes care of reopening [B] in read-write
mode, and commit_complete() puts it back in read-only mode once the
operation has finished.

In order to find [B] (the overlay node) we look for the node that has
[C] (the top node) as its backing image. However in commit_complete()
we're doing it after [C] has been removed from the chain, so [B] is
never found and remains in read-write mode.

This patch gets the overlay node before the backing chain is
manipulated.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-id: 1471836963-28548-1-git-send-email-berto@igalia.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-09-20 22:12:57 +02:00
Sascha Silbe
f14a39ccb9 Improve block job rate limiting for small bandwidth values
ratelimit_calculate_delay() previously reset the accounting every time
slice, no matter how much data had been processed before. This had (at
least) two consequences:

1. The minimum speed is rather large, e.g. 5 MiB/s for commit and stream.

   Not sure if there are real-world use cases where this would be a
   problem. Mirroring and backup over a slow link (e.g. DSL) would
   come to mind, though.

2. Tests for block job operations (e.g. cancel) were rather racy

   All block jobs currently use a time slice of 100ms. That's a
   reasonable value to get smooth output during regular
   operation. However this also meant that the state of block jobs
   changed every 100ms, no matter how low the configured limit was. On
   busy hosts, qemu often transferred additional chunks until the test
   case had a chance to cancel the job.

Fix the block job rate limit code to delay for more than one time
slice to address the above issues. To make it easier to handle
oversized chunks we switch the semantics from returning a delay
_before_ the current request to a delay _after_ the current
request. If necessary, this delay consists of multiple time slice
units.

Since the mirror job sends multiple chunks in one go even if the rate
limit was exceeded in between, we need to keep track of the start of
the current time slice so we can correctly re-compute the delay for
the updated amount of data.

The minimum bandwidth now is 1 data unit per time slice. The block
jobs are currently passing the amount of data transferred in sectors
and using 100ms time slices, so this translates to 5120
bytes/second. With chunk sizes usually being O(512KiB), tests have
plenty of time (O(100s)) to operate on block jobs. The chance of a
race condition now is fairly remote, except possibly on insanely
loaded systems.

Signed-off-by: Sascha Silbe <silbe@linux.vnet.ibm.com>
Message-id: 1467127721-9564-2-git-send-email-silbe@linux.vnet.ibm.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-07-13 13:41:38 +02:00
Kevin Wolf
1e8fb7f1ee commit: Fix use of error handling policy
Commit implemented the 'enospc' policy as 'ignore' if the error was not
ENOSPC. The QAPI documentation promises that it's treated as 'stop'.
Using the common block job error handling function fixes this and also
adds the missing QMP event.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2016-07-13 13:32:27 +02:00
Paolo Bonzini
0b8b8753e4 coroutine: move entry argument to qemu_coroutine_create
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>
2016-07-13 13:26:02 +02:00
Alberto Garcia
fd62c609ed commit: Add 'job-id' parameter to 'block-commit'
This patch adds a new optional 'job-id' parameter to 'block-commit',
allowing the user to specify the ID of the block job to be created.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-07-13 13:26:02 +02:00
Alberto Garcia
7f0317cfc8 blockjob: Add 'job_id' parameter to block_job_create()
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>
2016-07-13 13:26:02 +02:00
Kevin Wolf
f8e2bd538d block: Use BlockBackend for I/O in bdrv_commit()
Just like block jobs, the HMP commit command should use its own
BlockBackend for doing I/O on BlockDriverStates.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-05 16:46:27 +02:00
Kevin Wolf
83fd6dd3e7 block: Move bdrv_commit() to block/commit.c
No code changes, just moved from one file to another.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
2016-07-05 16:46:27 +02:00
Alberto Garcia
834fe28ddf block: Create the commit block job before reopening any image
If the base or overlay images need to be reopened in read-write mode
but the block_job_create() call fails then no one will put those
images back in read-only mode.

We can solve this problem easily by calling block_job_create() first.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Message-id: aa495045770a6f1a7cc5d408397a17c75097fdd8.1464346103.git.berto@igalia.com
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2016-06-16 15:20:37 +02:00
Kevin Wolf
4653456a5f commit: Use BlockBackend for I/O
This changes the commit block job to use the job's BlockBackend for
performing its I/O. job->bs isn't used by the commit code any more
afterwards.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2016-05-25 19:04:21 +02:00
Kevin Wolf
66a0fae438 blockjob: Don't touch BDS iostatus
Block jobs don't actually make use of the iostatus for their BDSes, but
they manage a separate block job iostatus. Still, they require that it
is enabled for the source BDS and they enable it automatically for the
target and set the error handling mode - which ends up never being used
by the job.

This patch removes all of the BDS iostatus handling from the block job,
which removes another few bs->blk accesses.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2016-05-19 16:45:31 +02:00
Markus Armbruster
da34e65cb4 include/qemu/osdep.h: Don't include qapi/error.h
Commit 57cb38b included qapi/error.h into qemu/osdep.h to get the
Error typedef.  Since then, we've moved to include qemu/osdep.h
everywhere.  Its file comment explains: "To avoid getting into
possible circular include dependencies, this file should not include
any other QEMU headers, with the exceptions of config-host.h,
compiler.h, os-posix.h and os-win32.h, all of which are doing a
similar job to this file and are under similar constraints."
qapi/error.h doesn't do a similar job, and it doesn't adhere to
similar constraints: it includes qapi-types.h.  That's in excess of
100KiB of crap most .c files don't actually need.

Add the typedef to qemu/typedefs.h, and include that instead of
qapi/error.h.  Include qapi/error.h in .c files that need it and don't
get it now.  Include qapi-types.h in qom/object.h for uint16List.

Update scripts/clean-includes accordingly.  Update it further to match
reality: replace config.h by config-target.h, add sysemu/os-posix.h,
sysemu/os-win32.h.  Update the list of includes in the qemu/osdep.h
comment quoted above similarly.

This reduces the number of objects depending on qapi/error.h from "all
of them" to less than a third.  Unfortunately, the number depending on
qapi-types.h shrinks only a little.  More work is needed for that one.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
[Fix compilation without the spice devel packages. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-22 22:20:15 +01:00
Peter Maydell
80c71a241a block: Clean up includes
Clean up includes so that osdep.h is included first and headers
which it implies are not included manually.

This commit was created with scripts/clean-includes.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2016-01-20 13:36:23 +01:00
Alberto Garcia
3db2bd5508 commit: reopen overlay_bs before base
'block-commit' needs write access to two different nodes of the chain:

- 'base', because that's where the data is written to.
- the overlay of 'top', because it needs to update the backing file
  string to point to 'base' after the operation.

Both images have to be opened in read-write mode, and commit_start()
takes care of reopening them if necessary.

With the current implementation, however, when overlay_bs is reopened
in read-write mode it has the side effect of making 'base' read-only
again, eventually making 'block-commit' fail.

This needs to be fixed in bdrv_reopen(), but until we get to that it
can be worked around simply by swapping the order of base and
overlay_bs in the reopen queue.

In order to reproduce this bug, overlay_bs needs to be initially in
read-only mode. That is: the 'top' parameter of 'block-commit' cannot
be the active layer nor its immediate backing chain.

Cc: qemu-stable@nongnu.org
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-11-11 16:25:47 +01:00
Max Reitz
373340b26c block: Move I/O status and error actions into BB
These options are only relevant for the user of a whole BDS tree (like a
guest device or a block job) and should thus be moved into the
BlockBackend.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2015-10-23 18:18:23 +02:00
Kevin Wolf
4d2cb09251 block: Allow specifying driver-specific options to reopen
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
2015-09-14 16:51:36 +02:00
Markus Armbruster
cc7a8ea740 Include qapi/qmp/qerror.h exactly where needed
In particular, don't include it into headers.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com>
2015-06-22 18:20:41 +02:00
Markus Armbruster
c6bd8c706a qerror: Clean up QERR_ macros to expand into a single string
These macros expand into error class enumeration constant, comma,
string.  Unclean.  Has been that way since commit 13f59ae.

The error class is always ERROR_CLASS_GENERIC_ERROR since the previous
commit.

Clean up as follows:

* Prepend every use of a QERR_ macro by ERROR_CLASS_GENERIC_ERROR, and
  delete it from the QERR_ macro.  No change after preprocessing.

* Rewrite error_set(ERROR_CLASS_GENERIC_ERROR, ...) into
  error_setg(...).  Again, no change after preprocessing.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com>
2015-06-22 18:20:40 +02:00
Stefan Hajnoczi
9e85cd5ce0 block: let commit blockjob run in BDS AioContext
The commit block job must run in the BlockDriverState AioContext so that
it works with dataplane.

Acquire the AioContext in blockdev.c so starting the block job is safe.
One detail here is that the bdrv_drain_all() must be moved inside the
aio_context_acquire() region so requests cannot sneak in between the
drain and acquire.

The completion code in block/commit.c must perform backing chain
manipulation and bdrv_reopen() from the main loop.  Use
block_job_defer_to_main_loop() to achieve that.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 1413889440-32577-11-git-send-email-stefanha@redhat.com
2014-11-03 11:41:49 +00:00
Markus Armbruster
097310b53e block: Rename BlockDriverCompletionFunc to BlockCompletionFunc
I'll use it with block backends shortly, and the name is going to fit
badly there.  It's a block layer thing anyway, not just a block driver
thing.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2014-10-20 13:41:27 +02:00
Jeff Cody
54e2690090 block: extend block-commit to accept a string for the backing file
On some image chains, QEMU may not always be able to resolve the
filenames properly, when updating the backing file of an image
after a block commit.

For instance, certain relative pathnames may fail, or drives may
have been specified originally by file descriptor (e.g. /dev/fd/???),
or a relative protocol pathname may have been used.

In these instances, QEMU may lack the information to be able to make
the correct choice, but the user or management layer most likely does
have that knowledge.

With this extension to the block-commit api, the user is able to change
the backing file of the overlay image as part of the block-commit
operation.

This allows the change to be 'safe', in the sense that if the attempt
to write the overlay image metadata fails, then the block-commit
operation returns failure, without disrupting the guest.

If the commit top is the active layer, then specifying the backing
file string will be treated as an error (there is no overlay image
to modify in that case).

If a backing file string is not specified in the command, the backing
file string to use is determined in the same manner as it was
previously.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-07-01 10:47:01 +02:00
Cole Robinson
f231b88db1 qerror.h: Remove QERR defines that are only used once
Just hardcode them in the callers

Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Cole Robinson <crobinso@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-04-25 09:19:59 -04:00
Fam Zheng
18da7f94cd commit: Remove unused check
We support top == active for commit now, remove the check and add an
assertion here.

Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-12-20 16:26:16 +01:00
Fam Zheng
79e14bf778 qapi: make use of new BlockJobType
Switch the string to enum type BlockJobType in BlockJobDriver.

Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-10-11 10:52:54 +02:00
Fam Zheng
3fc4b10af0 blockjob: rename BlockJobType to BlockJobDriver
We will use BlockJobType as the enum type name of block jobs in QAPI,
rename current BlockJobType to BlockJobDriver, which will eventually
become a set of operations, similar to block drivers.

Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-10-11 10:52:54 +02:00
Paolo Bonzini
4f5786376e block: remove bdrv_is_allocated_above/bdrv_co_is_allocated_above distinction
Now that bdrv_is_allocated detects coroutine context, the two can
use the same code.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-09-06 15:25:09 +02:00
Alex Bligh
7483d1e547 aio / timers: convert block_job_sleep_ns and co_sleep_ns to new API
Convert block_job_sleep_ns and co_sleep_ns to use the new timer
API.

Signed-off-by: Alex Bligh <alex@alex.org.uk>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-08-22 19:14:24 +02:00
Kevin Wolf
f59fee8d50 block: Make BlockJobTypes const
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2013-06-28 09:20:27 +02:00
Jeff Cody
6d759117d3 block: fix null-pointer bug on error case in block commit
This is a bug that was caught by a coverity run by Markus.  In
the error case when we errored out to exit_restore_open early in the
function, 'overlay_bs' was still NULL at that point, although it is
used to look up flags and perform a bdrv_reopen().

Move the overlay_bs lookup to where it is needed, and check for NULL
before restoring the flags.  Also get rid of the unneeded parameter
initialization.

Reported-By: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-01-17 10:51:11 +01:00