| Message ID | 20250414112554.3025113-9-ming.lei@redhat.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | ublk: simplify & improve IO canceling | expand |
On Mon, Apr 14, 2025 at 07:25:49PM +0800, Ming Lei wrote: > 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. > > Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Uday Shankar <ushankar@purestorage.com> > --- > 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 f827c2ef00a9..37a0cb8011c1 100644 > --- a/drivers/block/ublk_drv.c > +++ b/drivers/block/ublk_drv.c > @@ -122,15 +122,6 @@ 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. > @@ -1083,12 +1074,6 @@ 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; > @@ -1138,47 +1123,6 @@ 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) > { > @@ -1670,10 +1614,26 @@ 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) > { > @@ -1690,10 +1650,8 @@ 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); > - } > } > } > } > -- > 2.47.0 >
diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c index f827c2ef00a9..37a0cb8011c1 100644 --- a/drivers/block/ublk_drv.c +++ b/drivers/block/ublk_drv.c @@ -122,15 +122,6 @@ 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. @@ -1083,12 +1074,6 @@ 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; @@ -1138,47 +1123,6 @@ 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) { @@ -1670,10 +1614,26 @@ 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) { @@ -1690,10 +1650,8 @@ 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); - } } } }
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. Signed-off-by: Ming Lei <ming.lei@redhat.com> --- drivers/block/ublk_drv.c | 82 ++++++++++------------------------------ 1 file changed, 20 insertions(+), 62 deletions(-)