diff options
| -rw-r--r-- | block/io.c | 11 | ||||
| -rw-r--r-- | include/block/aio-wait.h | 22 |
2 files changed, 18 insertions, 15 deletions
diff --git a/block/io.c b/block/io.c index 983307cf03..bc7a2d78b8 100644 --- a/block/io.c +++ b/block/io.c @@ -182,13 +182,22 @@ static void bdrv_drain_invoke(BlockDriverState *bs, bool begin) BDRV_POLL_WHILE(bs, !data.done); } +/* Returns true if BDRV_POLL_WHILE() should go into a blocking aio_poll() */ +static bool bdrv_drain_poll(BlockDriverState *bs) +{ + /* Execute pending BHs first and check everything else only after the BHs + * have executed. */ + while (aio_poll(bs->aio_context, false)); + return atomic_read(&bs->in_flight); +} + static bool bdrv_drain_recurse(BlockDriverState *bs) { BdrvChild *child, *tmp; bool waited; /* Wait for drained requests to finish */ - waited = BDRV_POLL_WHILE(bs, atomic_read(&bs->in_flight) > 0); + waited = BDRV_POLL_WHILE(bs, bdrv_drain_poll(bs)); QLIST_FOREACH_SAFE(child, &bs->children, next, tmp) { BlockDriverState *bs = child->bs; diff --git a/include/block/aio-wait.h b/include/block/aio-wait.h index 8c90a2e66e..783d3678dd 100644 --- a/include/block/aio-wait.h +++ b/include/block/aio-wait.h @@ -73,29 +73,23 @@ typedef struct { */ #define AIO_WAIT_WHILE(wait, ctx, cond) ({ \ bool waited_ = false; \ - bool busy_ = true; \ AioWait *wait_ = (wait); \ AioContext *ctx_ = (ctx); \ if (in_aio_context_home_thread(ctx_)) { \ - while ((cond) || busy_) { \ - busy_ = aio_poll(ctx_, (cond)); \ - waited_ |= !!(cond) | busy_; \ + while ((cond)) { \ + aio_poll(ctx_, true); \ + waited_ = true; \ } \ } else { \ assert(qemu_get_current_aio_context() == \ qemu_get_aio_context()); \ /* Increment wait_->num_waiters before evaluating cond. */ \ atomic_inc(&wait_->num_waiters); \ - while (busy_) { \ - if ((cond)) { \ - waited_ = busy_ = true; \ - aio_context_release(ctx_); \ - aio_poll(qemu_get_aio_context(), true); \ - aio_context_acquire(ctx_); \ - } else { \ - busy_ = aio_poll(ctx_, false); \ - waited_ |= busy_; \ - } \ + while ((cond)) { \ + aio_context_release(ctx_); \ + aio_poll(qemu_get_aio_context(), true); \ + aio_context_acquire(ctx_); \ + waited_ = true; \ } \ atomic_dec(&wait_->num_waiters); \ } \ |