[PATCH AUTOSEL 5.17 01/23] scsi: scsi_dh_alua: Properly handle the ALUA transitioning state

[PATCH AUTOSEL 5.17 01/23] scsi: scsi_dh_alua: Properly handle the ALUA transitioning state

[Sasha Levin]

From: Brian Bunker <brian@purestorage.com>

[ 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@mail.gmail.com
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Krishna Kant <krishna.kant@purestorage.com>
Acked-by: Seamus Connor <sconnor@purestorage.com>
Signed-off-by: Brian Bunker <brian@purestorage.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/scsi/device_handler/scsi_dh_alua.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

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;
-- 
2.35.1

[PATCH AUTOSEL 5.17 02/23] scsi: qla2xxx: Fix missed DMA unmap for aborted commands

[Sasha Levin]

From: Gleb Chesnokov <Chesnokov.G@raidix.com>

[ Upstream commit 26f9ce53817a8fd84b69a73473a7de852a24c897 ]

Aborting commands that have already been sent to the firmware can
cause BUG in qlt_free_cmd(): BUG_ON(cmd->sg_mapped)

For instance:

 - Command passes rdx_to_xfer state, maps sgl, sends to the firmware

 - Reset occurs, qla2xxx performs ISP error recovery, aborts the command

 - Target stack calls qlt_abort_cmd() and then qlt_free_cmd()

 - BUG_ON(cmd->sg_mapped) in qlt_free_cmd() occurs because sgl was not
   unmapped

Thus, unmap sgl in qlt_abort_cmd() for commands with the aborted flag set.

Link: https://lore.kernel.org/r/AS8PR10MB4952D545F84B6B1DFD39EC1E9DEE9@AS8PR10MB4952.EURPRD10.PROD.OUTLOOK.COM
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Gleb Chesnokov <Chesnokov.G@raidix.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/scsi/qla2xxx/qla_target.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/scsi/qla2xxx/qla_target.c b/drivers/scsi/qla2xxx/qla_target.c
index b109716d44fb..7ab3c9e4d478 100644
--- a/drivers/scsi/qla2xxx/qla_target.c
+++ b/drivers/scsi/qla2xxx/qla_target.c
@@ -3837,6 +3837,9 @@ int qlt_abort_cmd(struct qla_tgt_cmd *cmd)
 
 	spin_lock_irqsave(&cmd->cmd_lock, flags);
 	if (cmd->aborted) {
+		if (cmd->sg_mapped)
+			qlt_unmap_sg(vha, cmd);
+
 		spin_unlock_irqrestore(&cmd->cmd_lock, flags);
 		/*
 		 * It's normal to see 2 calls in this path:
-- 
2.35.1