From: Hannes Reinecke <hare@xxxxxxxx>
For hardware only supporting active/optimized there's no point in
ever re-issuing RTPG as the only new state we can possibly read is
active/optimized.
This avoid spurious errors during path failover on such arrays.
Signed-off-by: Hannes Reinecke <hare@xxxxxxxx>
---
drivers/scsi/device_handler/scsi_dh_alua.c | 35 ++++++++++++++++++++++--------
1 file changed, 26 insertions(+), 9 deletions(-)
diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c b/drivers/scsi/device_handler/scsi_dh_alua.c
index fd22dc6..b09c12b 100644
--- a/drivers/scsi/device_handler/scsi_dh_alua.c
+++ b/drivers/scsi/device_handler/scsi_dh_alua.c
@@ -40,6 +40,7 @@
#define TPGS_SUPPORT_LBA_DEPENDENT 0x10
#define TPGS_SUPPORT_OFFLINE 0x40
#define TPGS_SUPPORT_TRANSITION 0x80
+#define TPGS_SUPPORT_ALL 0xdf
#define RTPG_FMT_MASK 0x70
#define RTPG_FMT_EXT_HDR 0x10
@@ -81,6 +82,7 @@ struct alua_port_group {
int tpgs;
int state;
int pref;
+ int valid_states;
unsigned flags; /* used for optimizing STPG */
unsigned char transition_tmo;
unsigned long expiry;
@@ -243,6 +245,7 @@ static struct alua_port_group *alua_alloc_pg(struct scsi_device *sdev,
pg->group_id = group_id;
pg->tpgs = tpgs;
pg->state = SCSI_ACCESS_STATE_OPTIMAL;
+ pg->valid_states = TPGS_SUPPORT_ALL;
if (optimize_stpg)
pg->flags |= ALUA_OPTIMIZE_STPG;
kref_init(&pg->kref);
@@ -516,7 +519,7 @@ static int alua_rtpg(struct scsi_device *sdev, struct alua_port_group *pg)
{
struct scsi_sense_hdr sense_hdr;
struct alua_port_group *tmp_pg;
- int len, k, off, valid_states = 0, bufflen = ALUA_RTPG_SIZE;
+ int len, k, off, bufflen = ALUA_RTPG_SIZE;
unsigned char *desc, *buff;
unsigned err, retval;
unsigned int tpg_desc_tbl_off;
@@ -541,6 +544,20 @@ static int alua_rtpg(struct scsi_device *sdev, struct alua_port_group *pg)
retval = submit_rtpg(sdev, buff, bufflen, &sense_hdr, pg->flags);
if (retval) {
+ /*
+ * If the target only supports active/optimized there's
+ * not much we can do; it's not that we can switch paths
+ * or somesuch.
+ * So ignore any errors to avoid spurious failures during
+ * path failover.
+ */
+ if ((pg->valid_states & ~TPGS_SUPPORT_OPTIMIZED) == 0) {
+ sdev_printk(KERN_INFO, sdev,
+ "%s: ignoring rtpg result %d\n",
+ ALUA_DH_NAME, retval);
+ kfree(buff);
+ return SCSI_DH_OK;
+ }
if (!scsi_sense_valid(&sense_hdr)) {
sdev_printk(KERN_INFO, sdev,
"%s: rtpg failed, result %d\n",
@@ -652,7 +669,7 @@ static int alua_rtpg(struct scsi_device *sdev, struct alua_port_group *pg)
rcu_read_unlock();
}
if (tmp_pg == pg)
- valid_states = desc[1];
+ tmp_pg->valid_states = desc[1];
spin_unlock_irqrestore(&tmp_pg->lock, flags);
}
kref_put(&tmp_pg->kref, release_port_group);
@@ -665,13 +682,13 @@ static int alua_rtpg(struct scsi_device *sdev, struct alua_port_group *pg)
"%s: port group %02x state %c %s supports %c%c%c%c%c%c%c\n",
ALUA_DH_NAME, pg->group_id, print_alua_state(pg->state),
pg->pref ? "preferred" : "non-preferred",
- valid_states&TPGS_SUPPORT_TRANSITION?'T':'t',
- valid_states&TPGS_SUPPORT_OFFLINE?'O':'o',
- valid_states&TPGS_SUPPORT_LBA_DEPENDENT?'L':'l',
- valid_states&TPGS_SUPPORT_UNAVAILABLE?'U':'u',
- valid_states&TPGS_SUPPORT_STANDBY?'S':'s',
- valid_states&TPGS_SUPPORT_NONOPTIMIZED?'N':'n',
- valid_states&TPGS_SUPPORT_OPTIMIZED?'A':'a');
+ pg->valid_states&TPGS_SUPPORT_TRANSITION?'T':'t',
+ pg->valid_states&TPGS_SUPPORT_OFFLINE?'O':'o',
+ pg->valid_states&TPGS_SUPPORT_LBA_DEPENDENT?'L':'l',
+ pg->valid_states&TPGS_SUPPORT_UNAVAILABLE?'U':'u',
+ pg->valid_states&TPGS_SUPPORT_STANDBY?'S':'s',
+ pg->valid_states&TPGS_SUPPORT_NONOPTIMIZED?'N':'n',
+ pg->valid_states&TPGS_SUPPORT_OPTIMIZED?'A':'a');
switch (pg->state) {
case SCSI_ACCESS_STATE_TRANSITIONING:
--
1.8.5.6
