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2019-07-15block/stream: Swap backing file change orderMax Reitz
bdrv_change_backing_file() can result in yields. Therefore, @base may no longer be the the backing_bs() of s->bottom afterwards. Just swap the order of the two calls to fix this. Signed-off-by: Max Reitz <mreitz@redhat.com> Message-id: 20190703172813.6868-4-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-07-15block/stream: Fix error pathMax Reitz
As of commit c624b015bf14fe01f1e6452a36e63b3ea1ae4998, the stream job only freezes the chain until the overlay of the base node. The error path must consider this. Fixes: c624b015bf14fe01f1e6452a36e63b3ea1ae4998 Signed-off-by: Max Reitz <mreitz@redhat.com> Message-id: 20190703172813.6868-3-mreitz@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-07-02block/stream: introduce a bottom nodeAndrey Shinkevich
The bottom node is the intermediate block device that has the base as its backing image. It is used instead of the base node while a block stream job is running to avoid dependency on the base that may change due to the parallel jobs. The change may take place due to a filter node as well that is inserted between the base and the intermediate bottom node. It occurs when the base node is the top one for another commit or stream job. After the introduction of the bottom node, don't freeze its backing child, that's the base, anymore. Suggested-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Message-id: 1559152576-281803-4-git-send-email-andrey.shinkevich@virtuozzo.com Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-07-02block/stream: refactor stream_run: drop gotoAndrey Shinkevich
The goto is unnecessary in the stream_run() since the common exit code was removed in the commit eb23654dbe43b549ea2a9ebff9d8e: "jobs: utilize job_exit shim". Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-id: 1559152576-281803-3-git-send-email-andrey.shinkevich@virtuozzo.com Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-07-02block: include base when checking image chain for block allocationAndrey Shinkevich
This patch is used in the 'block/stream: introduce a bottom node' that is following. Instead of the base node, the caller may pass the node that has the base as its backing image to the function bdrv_is_allocated_above() with a new parameter include_base = true and get rid of the dependency on the base that may change during commit/stream parallel jobs. Now, if the specified base is not found in the backing image chain, the QEMU will abort. Suggested-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Alberto Garcia <berto@igalia.com> Message-id: 1559152576-281803-2-git-send-email-andrey.shinkevich@virtuozzo.com [mreitz: Squashed in the following as a rebase on conflicting patches:] Message-id: e3cf99ae-62e9-8b6e-5a06-d3c8b9363b85@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2019-04-30block/stream: use buffer-based ioVladimir Sementsov-Ogievskiy
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-04-02block: freeze the backing chain earlier in stream_start()Alberto Garcia
Commit 6585493369819a48d34a86d57ec6b97cb5cd9bc0 added code to freeze the backing chain from 'top' to 'base' for the duration of the block-stream job. The problem is that the freezing happens too late in stream_start(): during the bdrv_reopen_set_read_only() call earlier in that function another job can jump in and remove the base image. If that happens we have an invalid chain and QEMU crashes. This patch puts the bdrv_freeze_backing_chain() call at the beginning of the function. Signed-off-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-03-12block: Freeze the backing chain for the duration of the stream jobAlberto Garcia
Signed-off-by: Alberto Garcia <berto@igalia.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2019-02-22block/stream: use QEMU_IOVEC_INIT_BUFVladimir Sementsov-Ogievskiy
Use new QEMU_IOVEC_INIT_BUF() instead of qemu_iovec_init_external( ... , 1), which simplifies the code. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-id: 20190218140926.333779-7-vsementsov@virtuozzo.com Message-Id: <20190218140926.333779-7-vsementsov@virtuozzo.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2018-12-14block: Use bdrv_reopen_set_read_only() in stream_start/complete()Alberto Garcia
This patch replaces the bdrv_reopen() calls that set and remove the BDRV_O_RDWR flag with the new bdrv_reopen_set_read_only() function. Signed-off-by: Alberto Garcia <berto@igalia.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-09-25block/stream: refactor stream to use job callbacksJohn Snow
Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-id: 20180906130225.5118-8-jsnow@redhat.com Reviewed-by: Jeff Cody <jcody@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-09-25block/stream: add block job creation flagsJohn Snow
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: 20180906130225.5118-4-jsnow@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-08-31jobs: utilize job_exit shimJohn Snow
Utilize the job_exit shim by not calling job_defer_to_main_loop, and where applicable, converting the deferred callback into the job_exit callback. This converts backup, stream, create, and the unit tests all at once. Most of these jobs do not see any changes to the order in which they clean up their resources, except the test-blockjob-txn test, which now puts down its bs before job_completed is called. This is safe for the same reason the reordering in the mirror job is safe, because job_completed no longer runs under two locks, making the unref safe even if it causes a flush. Signed-off-by: John Snow <jsnow@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-id: 20180830015734.19765-7-jsnow@redhat.com Signed-off-by: Max Reitz <mreitz@redhat.com>
2018-08-31jobs: canonize Error objectJohn Snow
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>
2018-08-31jobs: change start callback to run callbackJohn Snow
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>
2018-05-30job: Add error message for failing jobsKevin Wolf
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>
2018-05-23job: Move progress fields to JobKevin Wolf
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>
2018-05-23job: Move completion and cancellation to JobKevin Wolf
This moves the top-level job completion and cancellation functions from BlockJob to Job. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-05-23job: Add job_drain()Kevin Wolf
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>
2018-05-23job: Move BlockJobCreateFlags to JobKevin Wolf
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>
2018-05-23job: Move pause/resume functions to JobKevin Wolf
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>
2018-05-23job: Add job_sleep_ns()Kevin Wolf
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>
2018-05-23job: Move coroutine and related code to JobKevin Wolf
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>
2018-05-23job: Move defer_to_main_loop to JobKevin Wolf
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>
2018-05-23job: Move cancelled to JobKevin Wolf
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>
2018-05-23job: Add reference countingKevin Wolf
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>
2018-05-23job: Add JobDriver.job_typeKevin Wolf
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>
2018-05-23job: Rename BlockJobType into JobTypeKevin Wolf
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>
2018-05-23job: Create Job, JobDriver and job_create()Kevin Wolf
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>
2018-05-15blockjob: Introduce block_job_ratelimit_get_delay()Kevin Wolf
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>
2018-05-15blockjob: Implement block_job_set_speed() centrallyKevin Wolf
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>
2018-05-15blockjob: Move RateLimit to BlockJobKevin Wolf
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>
2018-05-15blockjob: Wrappers for progress counter accessKevin Wolf
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>
2018-04-10commit/stream: Reset delay_nsKevin Wolf
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>
2018-03-19blockjobs: model single jobs as transactionsJohn Snow
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>
2017-11-29blockjob: remove clock argument from block_job_sleep_nsPaolo Bonzini
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>
2017-07-10block: Make bdrv_is_allocated_above() byte-basedEric Blake
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>
2017-07-10block: Make bdrv_is_allocated() byte-basedEric Blake
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>
2017-07-10stream: Switch stream_run() to byte-basedEric Blake
We are gradually converting to byte-based interfaces, as they are easier to reason about than sector-based. Change the internal loop iteration of streaming 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>
2017-07-10stream: Drop reached_end for stream_complete()Eric Blake
stream_complete() skips the work of rewriting the backing file if the job was cancelled, if data->reached_end is false, or if there was an error detected (non-zero data->ret) during the streaming. But note that in stream_run(), data->reached_end is only set if the loop ran to completion, and data->ret is only 0 in two cases: either the loop ran to completion (possibly by cancellation, but stream_complete checks for that), or we took an early goto out because there is no bs->backing. Thus, we can preserve the same semantics without the use of reached_end, by merely checking for bs->backing (and logically, if there was no backing file, streaming is a no-op, so there is no backing file to rewrite). Suggested-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Eric Blake <eblake@redhat.com> Reviewed-by: John Snow <jsnow@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-07-10stream: Switch stream_populate() to byte-basedEric Blake
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>
2017-07-10trace: Show blockjob actions via bytes, not sectorsEric Blake
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>
2017-07-10blockjob: Track job ratelimits via bytes, not sectorsEric Blake
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>
2017-05-26stream: fix crash in stream_start() when block_job_create() failsAlberto Garcia
The code that tries to reopen a BlockDriverState in stream_start() when the creation of a new block job fails crashes because it attempts to dereference a pointer that is known to be NULL. This is a regression introduced in a170a91fd3eab6155da39e740381867e, likely because the code was copied from stream_complete(). Cc: qemu-stable@nongnu.org Reported-by: Kashyap Chamarthy <kchamart@redhat.com> Signed-off-by: Alberto Garcia <berto@igalia.com> Tested-by: Kashyap Chamarthy <kchamart@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-02-28block: Add Error parameter to bdrv_set_backing_hd()Kevin Wolf
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>
2017-02-28stream: Use real permissions in streaming block jobKevin Wolf
The correct permissions are relatively obvious here (and explained in code comments). For intermediate streaming, we need to reopen the top node read-write before creating the job now because the permissions system catches attempts to get the BLK_PERM_WRITE_UNCHANGED permission on a read-only node. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Acked-by: Fam Zheng <famz@redhat.com>
2017-02-28blockjob: Add permissions to block_job_add_bdrv()Kevin Wolf
Block jobs don't actually do I/O through the the reference they create with block_job_add_bdrv(), but they might want to use the permisssion system to express what the block job does to intermediate nodes. This adds permissions to block_job_add_bdrv() to provide the means to request permissions. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Acked-by: Fam Zheng <famz@redhat.com>
2017-02-28blockjob: Add permissions to block_job_create()Kevin Wolf
This functions creates a BlockBackend internally, so the block jobs need to tell it what they want to do with the BB. Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Acked-by: Fam Zheng <famz@redhat.com>
2016-11-14blockjob: add block_job_startJohn Snow
Instead of automatically starting jobs at creation time via backup_start et al, we'd like to return a job object pointer that can be started manually at later point in time. For now, add the block_job_start mechanism and start the jobs automatically as we have been doing, with conversions job-by-job coming in later patches. Of note: cancellation of unstarted jobs will perform all the normal cleanup as if the job had started, particularly abort and clean. The only difference is that we will not emit any events, because the job never actually started. Signed-off-by: John Snow <jsnow@redhat.com> Message-id: 1478587839-9834-5-git-send-email-jsnow@redhat.com Signed-off-by: Jeff Cody <jcody@redhat.com>
2016-11-14blockjob: add .start fieldJohn Snow
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>