This is a note to let you know that I've just added the patch titled
scsi: scsi_dh_alua: Properly handle the ALUA transitioning state
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
scsi-scsi_dh_alua-properly-handle-the-alua-transitio.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 0589297f3b0c5d6bedd218b8cdb5ffb54b4893ca
Author: Brian Bunker <brian@xxxxxxxxxxxxxxx>
Date: Mon May 2 08:09:17 2022 -0700
scsi: scsi_dh_alua: Properly handle the ALUA transitioning state
[ Upstream commit 6056a92ceb2a7705d61df7ec5370548e96aee258 ]
The handling of the ALUA transitioning state is currently broken. When a
target goes into this state, it is expected that the target is allowed to
stay in this state for the implicit transition timeout without a path
failure. The handler has this logic, but it gets skipped currently.
When the target transitions, there is in-flight I/O from the initiator. The
first of these responses from the target will be a unit attention letting
the initiator know that the ALUA state has changed. The remaining
in-flight I/Os, before the initiator finds out that the portal state has
changed, will return not ready, ALUA state is transitioning. The portal
state will change to SCSI_ACCESS_STATE_TRANSITIONING. This will lead to all
new I/O immediately failing the path unexpectedly. The path failure happens
in less than a second instead of the expected successes until the
transition timer is exceeded.
Allow I/Os to continue while the path is in the ALUA transitioning
state. The handler already takes care of a target that stays in the
transitioning state for too long by changing the state to ALUA state
standby once the transition timeout is exceeded at which point the path
will fail.
Link: https://lore.kernel.org/r/CAHZQxy+4sTPz9+pY3=7VJH+CLUJsDct81KtnR2be8ycN5mhqTg@xxxxxxxxxxxxxx
Reviewed-by: Hannes Reinecke <hare@xxxxxxx>
Acked-by: Krishna Kant <krishna.kant@xxxxxxxxxxxxxxx>
Acked-by: Seamus Connor <sconnor@xxxxxxxxxxxxxxx>
Signed-off-by: Brian Bunker <brian@xxxxxxxxxxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c b/drivers/scsi/device_handler/scsi_dh_alua.c
index 37d06f993b76..1d9be771f3ee 100644
--- a/drivers/scsi/device_handler/scsi_dh_alua.c
+++ b/drivers/scsi/device_handler/scsi_dh_alua.c
@@ -1172,9 +1172,8 @@ static blk_status_t alua_prep_fn(struct scsi_device *sdev, struct request *req)
case SCSI_ACCESS_STATE_OPTIMAL:
case SCSI_ACCESS_STATE_ACTIVE:
case SCSI_ACCESS_STATE_LBA:
- return BLK_STS_OK;
case SCSI_ACCESS_STATE_TRANSITIONING:
- return BLK_STS_AGAIN;
+ return BLK_STS_OK;
default:
req->rq_flags |= RQF_QUIET;
return BLK_STS_IOERR;
