diff options
Diffstat (limited to 'blockjob.c')
-rw-r--r-- | blockjob.c | 189 |
1 files changed, 158 insertions, 31 deletions
diff --git a/blockjob.c b/blockjob.c index c02fe598b8..80adb9d52a 100644 --- a/blockjob.c +++ b/blockjob.c @@ -37,6 +37,19 @@ #include "qemu/timer.h" #include "qapi-event.h" +/* Transactional group of block jobs */ +struct BlockJobTxn { + + /* Is this txn being cancelled? */ + bool aborting; + + /* List of jobs */ + QLIST_HEAD(, BlockJob) jobs; + + /* Reference count */ + int refcnt; +}; + void *block_job_create(const BlockJobDriver *driver, BlockDriverState *bs, int64_t speed, BlockCompletionFunc *cb, void *opaque, Error **errp) @@ -60,6 +73,7 @@ void *block_job_create(const BlockJobDriver *driver, BlockDriverState *bs, job->cb = cb; job->opaque = opaque; job->busy = true; + job->refcnt = 1; bs->job = job; /* Only set speed when necessary to avoid NotSupported error */ @@ -68,7 +82,7 @@ void *block_job_create(const BlockJobDriver *driver, BlockDriverState *bs, block_job_set_speed(job, speed, &local_err); if (local_err) { - block_job_release(bs); + block_job_unref(job); error_propagate(errp, local_err); return NULL; } @@ -76,15 +90,101 @@ void *block_job_create(const BlockJobDriver *driver, BlockDriverState *bs, return job; } -void block_job_release(BlockDriverState *bs) +void block_job_ref(BlockJob *job) { - BlockJob *job = bs->job; + ++job->refcnt; +} - bs->job = NULL; - bdrv_op_unblock_all(bs, job->blocker); - error_free(job->blocker); - g_free(job->id); - g_free(job); +void block_job_unref(BlockJob *job) +{ + if (--job->refcnt == 0) { + job->bs->job = NULL; + bdrv_op_unblock_all(job->bs, job->blocker); + bdrv_unref(job->bs); + error_free(job->blocker); + g_free(job->id); + g_free(job); + } +} + +static void block_job_completed_single(BlockJob *job) +{ + if (!job->ret) { + if (job->driver->commit) { + job->driver->commit(job); + } + } else { + if (job->driver->abort) { + job->driver->abort(job); + } + } + job->cb(job->opaque, job->ret); + if (job->txn) { + block_job_txn_unref(job->txn); + } + block_job_unref(job); +} + +static void block_job_completed_txn_abort(BlockJob *job) +{ + AioContext *ctx; + BlockJobTxn *txn = job->txn; + BlockJob *other_job, *next; + + if (txn->aborting) { + /* + * We are cancelled by another job, which will handle everything. + */ + return; + } + txn->aborting = true; + /* We are the first failed job. Cancel other jobs. */ + QLIST_FOREACH(other_job, &txn->jobs, txn_list) { + ctx = bdrv_get_aio_context(other_job->bs); + aio_context_acquire(ctx); + } + QLIST_FOREACH(other_job, &txn->jobs, txn_list) { + if (other_job == job || other_job->completed) { + /* Other jobs are "effectively" cancelled by us, set the status for + * them; this job, however, may or may not be cancelled, depending + * on the caller, so leave it. */ + if (other_job != job) { + other_job->cancelled = true; + } + continue; + } + block_job_cancel_sync(other_job); + assert(other_job->completed); + } + QLIST_FOREACH_SAFE(other_job, &txn->jobs, txn_list, next) { + ctx = bdrv_get_aio_context(other_job->bs); + block_job_completed_single(other_job); + aio_context_release(ctx); + } +} + +static void block_job_completed_txn_success(BlockJob *job) +{ + AioContext *ctx; + BlockJobTxn *txn = job->txn; + BlockJob *other_job, *next; + /* + * Successful completion, see if there are other running jobs in this + * txn. + */ + QLIST_FOREACH(other_job, &txn->jobs, txn_list) { + if (!other_job->completed) { + return; + } + } + /* We are the last completed job, commit the transaction. */ + QLIST_FOREACH_SAFE(other_job, &txn->jobs, txn_list, next) { + ctx = bdrv_get_aio_context(other_job->bs); + aio_context_acquire(ctx); + assert(other_job->ret == 0); + block_job_completed_single(other_job); + aio_context_release(ctx); + } } void block_job_completed(BlockJob *job, int ret) @@ -92,8 +192,16 @@ void block_job_completed(BlockJob *job, int ret) BlockDriverState *bs = job->bs; assert(bs->job == job); - job->cb(job->opaque, ret); - block_job_release(bs); + assert(!job->completed); + job->completed = true; + job->ret = ret; + if (!job->txn) { + block_job_completed_single(job); + } else if (ret < 0 || block_job_is_cancelled(job)) { + block_job_completed_txn_abort(job); + } else { + block_job_completed_txn_success(job); + } } void block_job_set_speed(BlockJob *job, int64_t speed, Error **errp) @@ -178,43 +286,29 @@ struct BlockFinishData { int ret; }; -static void block_job_finish_cb(void *opaque, int ret) -{ - struct BlockFinishData *data = opaque; - - data->cancelled = block_job_is_cancelled(data->job); - data->ret = ret; - data->cb(data->opaque, ret); -} - static int block_job_finish_sync(BlockJob *job, void (*finish)(BlockJob *, Error **errp), Error **errp) { - struct BlockFinishData data; BlockDriverState *bs = job->bs; Error *local_err = NULL; + int ret; assert(bs->job == job); - /* Set up our own callback to store the result and chain to - * the original callback. - */ - data.job = job; - data.cb = job->cb; - data.opaque = job->opaque; - data.ret = -EINPROGRESS; - job->cb = block_job_finish_cb; - job->opaque = &data; + block_job_ref(job); finish(job, &local_err); if (local_err) { error_propagate(errp, local_err); + block_job_unref(job); return -EBUSY; } - while (data.ret == -EINPROGRESS) { + while (!job->completed) { aio_poll(bdrv_get_aio_context(bs), true); } - return (data.cancelled && data.ret == 0) ? -ECANCELED : data.ret; + ret = (job->cancelled && job->ret == 0) ? -ECANCELED : job->ret; + block_job_unref(job); + return ret; } /* A wrapper around block_job_cancel() taking an Error ** parameter so it may be @@ -406,3 +500,36 @@ void block_job_defer_to_main_loop(BlockJob *job, qemu_bh_schedule(data->bh); } + +BlockJobTxn *block_job_txn_new(void) +{ + BlockJobTxn *txn = g_new0(BlockJobTxn, 1); + QLIST_INIT(&txn->jobs); + txn->refcnt = 1; + return txn; +} + +static void block_job_txn_ref(BlockJobTxn *txn) +{ + txn->refcnt++; +} + +void block_job_txn_unref(BlockJobTxn *txn) +{ + if (txn && --txn->refcnt == 0) { + g_free(txn); + } +} + +void block_job_txn_add_job(BlockJobTxn *txn, BlockJob *job) +{ + if (!txn) { + return; + } + + assert(!job->txn); + job->txn = txn; + + QLIST_INSERT_HEAD(&txn->jobs, job, txn_list); + block_job_txn_ref(txn); +} |