scsi_dh_alua: update all port states
When we read in the target port group state we should be
updating all affected port groups, otherwise we risk
running out of sync.
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c b/drivers/scsi/device_handler/scsi_dh_alua.c
index ef5d6c3..98d87d9 100644
--- a/drivers/scsi/device_handler/scsi_dh_alua.c
+++ b/drivers/scsi/device_handler/scsi_dh_alua.c
@@ -476,11 +476,13 @@
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;
- unsigned char *ucp, *buff;
+ unsigned char *desc, *buff;
unsigned err, retval;
unsigned int tpg_desc_tbl_off;
unsigned char orig_transition_tmo;
+ unsigned long flags;
if (!pg->expiry) {
unsigned long transition_tmo = ALUA_FAILOVER_TIMEOUT * HZ;
@@ -582,18 +584,32 @@
else
tpg_desc_tbl_off = 4;
- for (k = tpg_desc_tbl_off, ucp = buff + tpg_desc_tbl_off;
+ for (k = tpg_desc_tbl_off, desc = buff + tpg_desc_tbl_off;
k < len;
- k += off, ucp += off) {
+ k += off, desc += off) {
+ u16 group_id = get_unaligned_be16(&desc[2]);
- if (pg->group_id == get_unaligned_be16(&ucp[2])) {
- pg->state = ucp[0] & 0x0f;
- pg->pref = ucp[0] >> 7;
- valid_states = ucp[1];
+ spin_lock_irqsave(&port_group_lock, flags);
+ tmp_pg = alua_find_get_pg(pg->device_id_str, pg->device_id_len,
+ group_id);
+ spin_unlock_irqrestore(&port_group_lock, flags);
+ if (tmp_pg) {
+ if (spin_trylock_irqsave(&tmp_pg->lock, flags)) {
+ if ((tmp_pg == pg) ||
+ !(tmp_pg->flags & ALUA_PG_RUNNING)) {
+ tmp_pg->state = desc[0] & 0x0f;
+ tmp_pg->pref = desc[0] >> 7;
+ }
+ if (tmp_pg == pg)
+ valid_states = desc[1];
+ spin_unlock_irqrestore(&tmp_pg->lock, flags);
+ }
+ kref_put(&tmp_pg->kref, release_port_group);
}
- off = 8 + (ucp[7] * 4);
+ off = 8 + (desc[7] * 4);
}
+ spin_lock_irqsave(&pg->lock, flags);
sdev_printk(KERN_INFO, sdev,
"%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),
@@ -630,6 +646,7 @@
pg->expiry = 0;
break;
}
+ spin_unlock_irqrestore(&pg->lock, flags);
kfree(buff);
return err;
}