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| author | Stefan Hajnoczi <stefanha@redhat.com> | 2014-10-21 12:03:54 +0100 |
|---|---|---|
| committer | Stefan Hajnoczi <stefanha@redhat.com> | 2014-11-03 11:41:49 +0000 |
| commit | dec7d421f85578b0949292336f784f55ac84812d (patch) | |
| tree | 1e3c37516831a97591874685d13f270e8cb7a2d5 /include | |
| parent | 723c5d93c51bdb3adbc238ce90195c0864aa6cd5 (diff) | |
| download | qemu-dec7d421f85578b0949292336f784f55ac84812d.tar.gz | |
blockjob: add block_job_defer_to_main_loop()
Block jobs will run in the BlockDriverState's AioContext, which may not
always be the QEMU main loop.
There are some block layer APIs that are either not thread-safe or risk
lock ordering problems. This includes bdrv_unref(), bdrv_close(), and
anything that calls bdrv_drain_all().
The block_job_defer_to_main_loop() API allows a block job to schedule a
function to run in the main loop with the BlockDriverState AioContext
held.
This function will be used to perform cleanup and backing chain
manipulations in block jobs.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 1413889440-32577-6-git-send-email-stefanha@redhat.com
Diffstat (limited to 'include')
| -rw-r--r-- | include/block/blockjob.h | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/include/block/blockjob.h b/include/block/blockjob.h index 9694f130b0..b6d4ebbe03 100644 --- a/include/block/blockjob.h +++ b/include/block/blockjob.h @@ -315,4 +315,23 @@ void block_job_iostatus_reset(BlockJob *job); BlockErrorAction block_job_error_action(BlockJob *job, BlockDriverState *bs, BlockdevOnError on_err, int is_read, int error); + +typedef void BlockJobDeferToMainLoopFn(BlockJob *job, void *opaque); + +/** + * block_job_defer_to_main_loop: + * @job: The job + * @fn: The function to run in the main loop + * @opaque: The opaque value that is passed to @fn + * + * Execute a given function in the main loop with the BlockDriverState + * AioContext acquired. Block jobs must call bdrv_unref(), bdrv_close(), and + * anything that uses bdrv_drain_all() in the main loop. + * + * The @job AioContext is held while @fn executes. + */ +void block_job_defer_to_main_loop(BlockJob *job, + BlockJobDeferToMainLoopFn *fn, + void *opaque); + #endif |