diff options
| -rw-r--r-- | block.c | 2 | ||||
| -rw-r--r-- | block/block-backend.c | 60 |
2 files changed, 54 insertions, 8 deletions
@@ -4713,7 +4713,7 @@ out: AioContext *bdrv_get_aio_context(BlockDriverState *bs) { - return bs->aio_context; + return bs ? bs->aio_context : qemu_get_aio_context(); } AioWait *bdrv_get_aio_wait(BlockDriverState *bs) diff --git a/block/block-backend.c b/block/block-backend.c index 0266ac990b..a775a3dd2f 100644 --- a/block/block-backend.c +++ b/block/block-backend.c @@ -73,6 +73,14 @@ struct BlockBackend { int quiesce_counter; VMChangeStateEntry *vmsh; bool force_allow_inactivate; + + /* Number of in-flight aio requests. BlockDriverState also counts + * in-flight requests but aio requests can exist even when blk->root is + * NULL, so we cannot rely on its counter for that case. + * Accessed with atomic ops. + */ + unsigned int in_flight; + AioWait wait; }; typedef struct BlockBackendAIOCB { @@ -1225,11 +1233,22 @@ int blk_make_zero(BlockBackend *blk, BdrvRequestFlags flags) return bdrv_make_zero(blk->root, flags); } +static void blk_inc_in_flight(BlockBackend *blk) +{ + atomic_inc(&blk->in_flight); +} + +static void blk_dec_in_flight(BlockBackend *blk) +{ + atomic_dec(&blk->in_flight); + aio_wait_kick(&blk->wait); +} + static void error_callback_bh(void *opaque) { struct BlockBackendAIOCB *acb = opaque; - bdrv_dec_in_flight(acb->common.bs); + blk_dec_in_flight(acb->blk); acb->common.cb(acb->common.opaque, acb->ret); qemu_aio_unref(acb); } @@ -1240,7 +1259,7 @@ BlockAIOCB *blk_abort_aio_request(BlockBackend *blk, { struct BlockBackendAIOCB *acb; - bdrv_inc_in_flight(blk_bs(blk)); + blk_inc_in_flight(blk); acb = blk_aio_get(&block_backend_aiocb_info, blk, cb, opaque); acb->blk = blk; acb->ret = ret; @@ -1263,7 +1282,7 @@ static const AIOCBInfo blk_aio_em_aiocb_info = { static void blk_aio_complete(BlkAioEmAIOCB *acb) { if (acb->has_returned) { - bdrv_dec_in_flight(acb->common.bs); + blk_dec_in_flight(acb->rwco.blk); acb->common.cb(acb->common.opaque, acb->rwco.ret); qemu_aio_unref(acb); } @@ -1284,7 +1303,7 @@ static BlockAIOCB *blk_aio_prwv(BlockBackend *blk, int64_t offset, int bytes, BlkAioEmAIOCB *acb; Coroutine *co; - bdrv_inc_in_flight(blk_bs(blk)); + blk_inc_in_flight(blk); acb = blk_aio_get(&blk_aio_em_aiocb_info, blk, cb, opaque); acb->rwco = (BlkRwCo) { .blk = blk, @@ -1521,14 +1540,41 @@ int blk_flush(BlockBackend *blk) void blk_drain(BlockBackend *blk) { - if (blk_bs(blk)) { - bdrv_drain(blk_bs(blk)); + BlockDriverState *bs = blk_bs(blk); + + if (bs) { + bdrv_drained_begin(bs); + } + + /* We may have -ENOMEDIUM completions in flight */ + AIO_WAIT_WHILE(&blk->wait, + blk_get_aio_context(blk), + atomic_mb_read(&blk->in_flight) > 0); + + if (bs) { + bdrv_drained_end(bs); } } void blk_drain_all(void) { - bdrv_drain_all(); + BlockBackend *blk = NULL; + + bdrv_drain_all_begin(); + + while ((blk = blk_all_next(blk)) != NULL) { + AioContext *ctx = blk_get_aio_context(blk); + + aio_context_acquire(ctx); + + /* We may have -ENOMEDIUM completions in flight */ + AIO_WAIT_WHILE(&blk->wait, ctx, + atomic_mb_read(&blk->in_flight) > 0); + + aio_context_release(ctx); + } + + bdrv_drain_all_end(); } void blk_set_on_error(BlockBackend *blk, BlockdevOnError on_read_error, |