From: Ming Lei ming.lei@redhat.com
Now ublk_abort_queue() is moved to ublk char device release handler, meantime our request queue is "quiesced" because either ->canceling was set from uring_cmd cancel function or all IOs are inflight and can't be completed by ublk server, things becomes easy much:
- all uring_cmd are done, so we needn't to mark io as UBLK_IO_FLAG_ABORTED for handling completion from uring_cmd
- ublk char device is closed, no one can hold IO request reference any more, so we can simply complete this request or requeue it for ublk_nosrv_should_reissue_outstanding.
Reviewed-by: Uday Shankar ushankar@purestorage.com Signed-off-by: Ming Lei ming.lei@redhat.com Link: https://lore.kernel.org/r/20250416035444.99569-8-ming.lei@redhat.com Signed-off-by: Jens Axboe axboe@kernel.dk --- drivers/block/ublk_drv.c | 82 ++++++++++------------------------------ 1 file changed, 20 insertions(+), 62 deletions(-)
diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c index c3f576a9dbf2..6000147ac2a5 100644 --- a/drivers/block/ublk_drv.c +++ b/drivers/block/ublk_drv.c @@ -115,15 +115,6 @@ struct ublk_uring_cmd_pdu { */ #define UBLK_IO_FLAG_OWNED_BY_SRV 0x02
-/* - * IO command is aborted, so this flag is set in case of - * !UBLK_IO_FLAG_ACTIVE. - * - * After this flag is observed, any pending or new incoming request - * associated with this io command will be failed immediately - */ -#define UBLK_IO_FLAG_ABORTED 0x04 - /* * UBLK_IO_FLAG_NEED_GET_DATA is set because IO command requires * get data buffer address from ublksrv. @@ -1054,12 +1045,6 @@ static inline void __ublk_complete_rq(struct request *req) unsigned int unmapped_bytes; blk_status_t res = BLK_STS_OK;
- /* called from ublk_abort_queue() code path */ - if (io->flags & UBLK_IO_FLAG_ABORTED) { - res = BLK_STS_IOERR; - goto exit; - } - /* failed read IO if nothing is read */ if (!io->res && req_op(req) == REQ_OP_READ) io->res = -EIO; @@ -1109,47 +1094,6 @@ static void ublk_complete_rq(struct kref *ref) __ublk_complete_rq(req); }
-static void ublk_do_fail_rq(struct request *req) -{ - struct ublk_queue *ubq = req->mq_hctx->driver_data; - - if (ublk_nosrv_should_reissue_outstanding(ubq->dev)) - blk_mq_requeue_request(req, false); - else - __ublk_complete_rq(req); -} - -static void ublk_fail_rq_fn(struct kref *ref) -{ - struct ublk_rq_data *data = container_of(ref, struct ublk_rq_data, - ref); - struct request *req = blk_mq_rq_from_pdu(data); - - ublk_do_fail_rq(req); -} - -/* - * Since ublk_rq_task_work_cb always fails requests immediately during - * exiting, __ublk_fail_req() is only called from abort context during - * exiting. So lock is unnecessary. - * - * Also aborting may not be started yet, keep in mind that one failed - * request may be issued by block layer again. - */ -static void __ublk_fail_req(struct ublk_queue *ubq, struct ublk_io *io, - struct request *req) -{ - WARN_ON_ONCE(io->flags & UBLK_IO_FLAG_ACTIVE); - - if (ublk_need_req_ref(ubq)) { - struct ublk_rq_data *data = blk_mq_rq_to_pdu(req); - - kref_put(&data->ref, ublk_fail_rq_fn); - } else { - ublk_do_fail_rq(req); - } -} - static void ubq_complete_io_cmd(struct ublk_io *io, int res, unsigned issue_flags) { @@ -1639,10 +1583,26 @@ static void ublk_commit_completion(struct ublk_device *ub, ublk_put_req_ref(ubq, req); }
+static void __ublk_fail_req(struct ublk_queue *ubq, struct ublk_io *io, + struct request *req) +{ + WARN_ON_ONCE(io->flags & UBLK_IO_FLAG_ACTIVE); + + if (ublk_nosrv_should_reissue_outstanding(ubq->dev)) + blk_mq_requeue_request(req, false); + else { + io->res = -EIO; + __ublk_complete_rq(req); + } +} + /* - * Called from ubq_daemon context via cancel fn, meantime quiesce ublk - * blk-mq queue, so we are called exclusively with blk-mq and ubq_daemon - * context, so everything is serialized. + * Called from ublk char device release handler, when any uring_cmd is + * done, meantime request queue is "quiesced" since all inflight requests + * can't be completed because ublk server is dead. + * + * So no one can hold our request IO reference any more, simply ignore the + * reference, and complete the request immediately */ static void ublk_abort_queue(struct ublk_device *ub, struct ublk_queue *ubq) { @@ -1659,10 +1619,8 @@ static void ublk_abort_queue(struct ublk_device *ub, struct ublk_queue *ubq) * will do it */ rq = blk_mq_tag_to_rq(ub->tag_set.tags[ubq->q_id], i); - if (rq && blk_mq_request_started(rq)) { - io->flags |= UBLK_IO_FLAG_ABORTED; + if (rq && blk_mq_request_started(rq)) __ublk_fail_req(ubq, io, rq); - } } } }