6.12-stable review patch. If anyone has any objections, please let me know.
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From: Uday Shankar ushankar@purestorage.com
[ Upstream commit 3b939b8f715e014adcc48f7827fe9417252f0833 ]
ublk currently supports the following behaviors on ublk server exit:
A: outstanding I/Os get errors, subsequently issued I/Os get errors B: outstanding I/Os get errors, subsequently issued I/Os queue C: outstanding I/Os get reissued, subsequently issued I/Os queue
and the following behaviors for recovery of preexisting block devices by a future incarnation of the ublk server:
1: ublk devices stopped on ublk server exit (no recovery possible) 2: ublk devices are recoverable using start/end_recovery commands
The userspace interface allows selection of combinations of these behaviors using flags specified at device creation time, namely:
default behavior: A + 1 UBLK_F_USER_RECOVERY: B + 2 UBLK_F_USER_RECOVERY|UBLK_F_USER_RECOVERY_REISSUE: C + 2
We can't easily change the userspace interface to allow independent selection of one of {A, B, C} and one of {1, 2}, but we can refactor the internal helpers which test for the flags. Replace the existing helpers with the following set:
ublk_nosrv_should_reissue_outstanding: tests for behavior C ublk_nosrv_[dev_]should_queue_io: tests for behavior B ublk_nosrv_should_stop_dev: tests for behavior 1
Signed-off-by: Uday Shankar ushankar@purestorage.com Reviewed-by: Ming Lei ming.lei@redhat.com Link: https://lore.kernel.org/r/20241007182419.3263186-3-ushankar@purestorage.com Signed-off-by: Jens Axboe axboe@kernel.dk Stable-dep-of: 6ee6bd5d4fce ("ublk: fix handling recovery & reissue in ublk_abort_queue()") Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/block/ublk_drv.c | 62 +++++++++++++++++++++++++++------------- 1 file changed, 42 insertions(+), 20 deletions(-)
diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c index 79b7bd8bfd458..dd328d40c7de5 100644 --- a/drivers/block/ublk_drv.c +++ b/drivers/block/ublk_drv.c @@ -681,22 +681,44 @@ static int ublk_max_cmd_buf_size(void) return __ublk_queue_cmd_buf_size(UBLK_MAX_QUEUE_DEPTH); }
-static inline bool ublk_queue_can_use_recovery_reissue( - struct ublk_queue *ubq) +/* + * Should I/O outstanding to the ublk server when it exits be reissued? + * If not, outstanding I/O will get errors. + */ +static inline bool ublk_nosrv_should_reissue_outstanding(struct ublk_device *ub) { - return (ubq->flags & UBLK_F_USER_RECOVERY) && - (ubq->flags & UBLK_F_USER_RECOVERY_REISSUE); + return (ub->dev_info.flags & UBLK_F_USER_RECOVERY) && + (ub->dev_info.flags & UBLK_F_USER_RECOVERY_REISSUE); }
-static inline bool ublk_queue_can_use_recovery( - struct ublk_queue *ubq) +/* + * Should I/O issued while there is no ublk server queue? If not, I/O + * issued while there is no ublk server will get errors. + */ +static inline bool ublk_nosrv_dev_should_queue_io(struct ublk_device *ub) +{ + return ub->dev_info.flags & UBLK_F_USER_RECOVERY; +} + +/* + * Same as ublk_nosrv_dev_should_queue_io, but uses a queue-local copy + * of the device flags for smaller cache footprint - better for fast + * paths. + */ +static inline bool ublk_nosrv_should_queue_io(struct ublk_queue *ubq) { return ubq->flags & UBLK_F_USER_RECOVERY; }
-static inline bool ublk_can_use_recovery(struct ublk_device *ub) +/* + * Should ublk devices be stopped (i.e. no recovery possible) when the + * ublk server exits? If not, devices can be used again by a future + * incarnation of a ublk server via the start_recovery/end_recovery + * commands. + */ +static inline bool ublk_nosrv_should_stop_dev(struct ublk_device *ub) { - return ub->dev_info.flags & UBLK_F_USER_RECOVERY; + return !(ub->dev_info.flags & UBLK_F_USER_RECOVERY); }
static void ublk_free_disk(struct gendisk *disk) @@ -1072,7 +1094,7 @@ static void __ublk_fail_req(struct ublk_queue *ubq, struct ublk_io *io, { WARN_ON_ONCE(io->flags & UBLK_IO_FLAG_ACTIVE);
- if (ublk_queue_can_use_recovery_reissue(ubq)) + if (ublk_nosrv_should_reissue_outstanding(ubq->dev)) blk_mq_requeue_request(req, false); else ublk_put_req_ref(ubq, req); @@ -1100,7 +1122,7 @@ static inline void __ublk_abort_rq(struct ublk_queue *ubq, struct request *rq) { /* We cannot process this rq so just requeue it. */ - if (ublk_queue_can_use_recovery(ubq)) + if (ublk_nosrv_dev_should_queue_io(ubq->dev)) blk_mq_requeue_request(rq, false); else blk_mq_end_request(rq, BLK_STS_IOERR); @@ -1245,10 +1267,10 @@ static enum blk_eh_timer_return ublk_timeout(struct request *rq) struct ublk_device *ub = ubq->dev;
if (ublk_abort_requests(ub, ubq)) { - if (ublk_can_use_recovery(ub)) - schedule_work(&ub->quiesce_work); - else + if (ublk_nosrv_should_stop_dev(ub)) schedule_work(&ub->stop_work); + else + schedule_work(&ub->quiesce_work); } return BLK_EH_DONE; } @@ -1277,7 +1299,7 @@ static blk_status_t ublk_queue_rq(struct blk_mq_hw_ctx *hctx, * Note: force_abort is guaranteed to be seen because it is set * before request queue is unqiuesced. */ - if (ublk_queue_can_use_recovery(ubq) && unlikely(ubq->force_abort)) + if (ublk_nosrv_should_queue_io(ubq) && unlikely(ubq->force_abort)) return BLK_STS_IOERR;
if (unlikely(ubq->canceling)) { @@ -1517,10 +1539,10 @@ static void ublk_uring_cmd_cancel_fn(struct io_uring_cmd *cmd, ublk_cancel_cmd(ubq, io, issue_flags);
if (need_schedule) { - if (ublk_can_use_recovery(ub)) - schedule_work(&ub->quiesce_work); - else + if (ublk_nosrv_should_stop_dev(ub)) schedule_work(&ub->stop_work); + else + schedule_work(&ub->quiesce_work); } }
@@ -1640,7 +1662,7 @@ static void ublk_stop_dev(struct ublk_device *ub) mutex_lock(&ub->mutex); if (ub->dev_info.state == UBLK_S_DEV_DEAD) goto unlock; - if (ublk_can_use_recovery(ub)) { + if (ublk_nosrv_dev_should_queue_io(ub)) { if (ub->dev_info.state == UBLK_S_DEV_LIVE) __ublk_quiesce_dev(ub); ublk_unquiesce_dev(ub); @@ -2738,7 +2760,7 @@ static int ublk_ctrl_start_recovery(struct ublk_device *ub, int i;
mutex_lock(&ub->mutex); - if (!ublk_can_use_recovery(ub)) + if (ublk_nosrv_should_stop_dev(ub)) goto out_unlock; if (!ub->nr_queues_ready) goto out_unlock; @@ -2791,7 +2813,7 @@ static int ublk_ctrl_end_recovery(struct ublk_device *ub, __func__, ub->dev_info.nr_hw_queues, header->dev_id);
mutex_lock(&ub->mutex); - if (!ublk_can_use_recovery(ub)) + if (ublk_nosrv_should_stop_dev(ub)) goto out_unlock;
if (ub->dev_info.state != UBLK_S_DEV_QUIESCED) {