When we receive a unit attention code of 'ALUA state changed'
we should recheck the state, as it might be due to an implicit
ALUA state transition.
At the same time a workqueue item might already be queued, which
should be started immediately to avoid any delays.
Signed-off-by: Hannes Reinecke <h...@suse.de>
---
drivers/scsi/device_handler/scsi_dh_alua.c | 48 +++++++++++++++---------------
1 file changed, 24 insertions(+), 24 deletions(-)
diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c
b/drivers/scsi/device_handler/scsi_dh_alua.c
index 85fd597..8717fd3 100644
--- a/drivers/scsi/device_handler/scsi_dh_alua.c
+++ b/drivers/scsi/device_handler/scsi_dh_alua.c
@@ -118,7 +118,7 @@ static char print_alua_state(int);
static void alua_rtpg_work(struct work_struct *work);
static void alua_stpg_work(struct work_struct *work);
static void alua_qdata_work(struct work_struct *work);
-static void alua_check(struct scsi_device *sdev);
+static void alua_check(struct scsi_device *sdev, bool force);
static void release_port_group(struct kref *kref)
{
@@ -423,7 +423,7 @@ static char print_alua_state(int state)
}
static int alua_check_sense(struct scsi_device *sdev,
- struct scsi_sense_hdr *sense_hdr)
+ struct scsi_sense_hdr *sense_hdr)
{
switch (sense_hdr->sense_key) {
case NOT_READY:
@@ -432,36 +432,34 @@ static int alua_check_sense(struct scsi_device *sdev,
* LUN Not Accessible - ALUA state transition
* Kickoff worker to update internal state.
*/
- alua_check(sdev);
- return ADD_TO_MLQUEUE;
+ alua_check(sdev, false);
+ return NEEDS_RETRY;
}
break;
case UNIT_ATTENTION:
- if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00)
- /*
- * Power On, Reset, or Bus Device Reset, just retry.
- */
- return ADD_TO_MLQUEUE;
- if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x04)
- /*
- * Device internal reset
- */
- return ADD_TO_MLQUEUE;
- if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x01)
+ if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00) {
/*
- * Mode Parameter Changed
+ * Power On, Reset, or Bus Device Reset.
+ * Might have obscured a state transition,
+ * so schedule a recheck.
*/
+ alua_check(sdev, true);
return ADD_TO_MLQUEUE;
- if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x06)
+ }
+ if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x06) {
/*
* ALUA state changed
*/
+ alua_check(sdev, true);
return ADD_TO_MLQUEUE;
- if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x07)
+ }
+ if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x07) {
/*
* Implicit ALUA state transition failed
*/
+ alua_check(sdev, true);
return ADD_TO_MLQUEUE;
+ }
break;
}
@@ -811,7 +809,7 @@ static void alua_qdata_work(struct work_struct *work)
static void alua_rtpg_queue(struct alua_port_group *pg,
struct scsi_device *sdev,
- struct alua_queue_data *qdata)
+ struct alua_queue_data *qdata, bool force)
{
int start_queue = 0;
unsigned long flags;
@@ -832,7 +830,9 @@ static void alua_rtpg_queue(struct alua_port_group *pg,
pg->rtpg_sdev = sdev;
scsi_device_get(sdev);
start_queue = 1;
- }
+ } else if (!(pg->flags & ALUA_PG_RUN_RTPG) && force)
+ start_queue = 1;
+
spin_unlock_irqrestore(&pg->rtpg_lock, flags);
if (start_queue)
@@ -873,7 +873,7 @@ static int alua_initialize(struct scsi_device *sdev, struct
alua_dh_data *h)
mutex_unlock(&h->init_mutex);
if (pg) {
pg->expiry = 0;
- alua_rtpg_queue(pg, sdev, NULL);
+ alua_rtpg_queue(pg, sdev, NULL, true);
kref_put(&pg->kref, release_port_group);
}
return error;
@@ -982,7 +982,7 @@ static int alua_activate(struct scsi_device *sdev,
pg->flags |= ALUA_OPTIMIZE_STPG;
spin_unlock_irqrestore(&pg->rtpg_lock, flags);
}
- alua_rtpg_queue(pg, sdev, qdata);
+ alua_rtpg_queue(pg, sdev, qdata, true);
kref_put(&pg->kref, release_port_group);
out:
if (fn)
@@ -996,7 +996,7 @@ out:
*
* Check the device status
*/
-static void alua_check(struct scsi_device *sdev)
+static void alua_check(struct scsi_device *sdev, bool force)
{
struct alua_dh_data *h = sdev->handler_data;
struct alua_port_group *pg;
@@ -1009,7 +1009,7 @@ static void alua_check(struct scsi_device *sdev)
}
kref_get(&pg->kref);
rcu_read_unlock();
- alua_rtpg_queue(pg, sdev, NULL);
+ alua_rtpg_queue(pg, sdev, NULL, force);
kref_put(&pg->kref, release_port_group);
rcu_read_unlock();
}
--
1.8.5.6
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