diff options
| -rw-r--r-- | blockjob.c | 38 | ||||
| -rw-r--r-- | include/block/blockjob.h | 35 |
2 files changed, 65 insertions, 8 deletions
diff --git a/blockjob.c b/blockjob.c index 21cc3ee332..874b573bd5 100644 --- a/blockjob.c +++ b/blockjob.c @@ -257,6 +257,32 @@ static bool block_job_should_pause(BlockJob *job) return job->pause_count > 0; } +void coroutine_fn block_job_pause_point(BlockJob *job) +{ + if (!block_job_should_pause(job)) { + return; + } + if (block_job_is_cancelled(job)) { + return; + } + + if (job->driver->pause) { + job->driver->pause(job); + } + + if (block_job_should_pause(job) && !block_job_is_cancelled(job)) { + job->paused = true; + job->busy = false; + qemu_coroutine_yield(); /* wait for block_job_resume() */ + job->busy = true; + job->paused = false; + } + + if (job->driver->resume) { + job->driver->resume(job); + } +} + void block_job_resume(BlockJob *job) { assert(job->pause_count > 0); @@ -364,11 +390,9 @@ void block_job_sleep_ns(BlockJob *job, QEMUClockType type, int64_t ns) if (!block_job_should_pause(job)) { co_aio_sleep_ns(blk_get_aio_context(job->blk), type, ns); } - /* The job can be paused while sleeping, so check this again */ - if (block_job_should_pause(job)) { - qemu_coroutine_yield(); - } job->busy = true; + + block_job_pause_point(job); } void block_job_yield(BlockJob *job) @@ -381,8 +405,12 @@ void block_job_yield(BlockJob *job) } job->busy = false; - qemu_coroutine_yield(); + if (!block_job_should_pause(job)) { + qemu_coroutine_yield(); + } job->busy = true; + + block_job_pause_point(job); } BlockJobInfo *block_job_query(BlockJob *job) diff --git a/include/block/blockjob.h b/include/block/blockjob.h index 8fcecf9a79..7739f37c3a 100644 --- a/include/block/blockjob.h +++ b/include/block/blockjob.h @@ -70,6 +70,20 @@ typedef struct BlockJobDriver { * never both. */ void (*abort)(BlockJob *job); + + /** + * If the callback is not NULL, it will be invoked when the job transitions + * into the paused state. Paused jobs must not perform any asynchronous + * I/O or event loop activity. This callback is used to quiesce jobs. + */ + void coroutine_fn (*pause)(BlockJob *job); + + /** + * If the callback is not NULL, it will be invoked when the job transitions + * out of the paused state. Any asynchronous I/O or event loop activity + * should be restarted from this callback. + */ + void coroutine_fn (*resume)(BlockJob *job); } BlockJobDriver; /** @@ -119,13 +133,19 @@ struct BlockJob { bool user_paused; /** - * Set to false by the job while it is in a quiescent state, where - * no I/O is pending and the job has yielded on any condition - * that is not detected by #aio_poll, such as a timer. + * Set to false by the job while the coroutine has yielded and may be + * re-entered by block_job_enter(). There may still be I/O or event loop + * activity pending. */ bool busy; /** + * Set to true by the job while it is in a quiescent state, where + * no I/O or event loop activity is pending. + */ + bool paused; + + /** * Set to true when the job is ready to be completed. */ bool ready; @@ -299,6 +319,15 @@ bool block_job_is_cancelled(BlockJob *job); BlockJobInfo *block_job_query(BlockJob *job); /** + * block_job_pause_point: + * @job: The job that is ready to pause. + * + * Pause now if block_job_pause() has been called. Block jobs that perform + * lots of I/O must call this between requests so that the job can be paused. + */ +void coroutine_fn block_job_pause_point(BlockJob *job); + +/** * block_job_pause: * @job: The job to be paused. * |