diff options
| -rw-r--r-- | blockjob.c | 45 | ||||
| -rw-r--r-- | include/block/blockjob.h | 19 |
2 files changed, 64 insertions, 0 deletions
diff --git a/blockjob.c b/blockjob.c index 448b9ce113..cd4b573adb 100644 --- a/blockjob.c +++ b/blockjob.c @@ -342,3 +342,48 @@ BlockErrorAction block_job_error_action(BlockJob *job, BlockDriverState *bs, } return action; } + +typedef struct { + BlockJob *job; + QEMUBH *bh; + AioContext *aio_context; + BlockJobDeferToMainLoopFn *fn; + void *opaque; +} BlockJobDeferToMainLoopData; + +static void block_job_defer_to_main_loop_bh(void *opaque) +{ + BlockJobDeferToMainLoopData *data = opaque; + AioContext *aio_context; + + qemu_bh_delete(data->bh); + + /* Prevent race with block_job_defer_to_main_loop() */ + aio_context_acquire(data->aio_context); + + /* Fetch BDS AioContext again, in case it has changed */ + aio_context = bdrv_get_aio_context(data->job->bs); + aio_context_acquire(aio_context); + + data->fn(data->job, data->opaque); + + aio_context_release(aio_context); + + aio_context_release(data->aio_context); + + g_free(data); +} + +void block_job_defer_to_main_loop(BlockJob *job, + BlockJobDeferToMainLoopFn *fn, + void *opaque) +{ + BlockJobDeferToMainLoopData *data = g_malloc(sizeof(*data)); + data->job = job; + data->bh = qemu_bh_new(block_job_defer_to_main_loop_bh, data); + data->aio_context = bdrv_get_aio_context(job->bs); + data->fn = fn; + data->opaque = opaque; + + qemu_bh_schedule(data->bh); +} 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 |