For ALUA we should be handling all states, independent of whether
the mode is explicit or implicit. For 'Transitioning' we should retry
for a certain amount of time; after that we're setting the port
to 'Standby' and return SCSI_DH_RETRY to signal upper layers
a retry is in order here.
Signed-off-by: Hannes Reinecke <hare@xxxxxxx>
Acked-by: Mike Snitzer <snitzer@xxxxxxxxxx>
diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c b/drivers/scsi/device_handler/scsi_dh_alua.c
index 1a970a7..6b72932 100644
--- a/drivers/scsi/device_handler/scsi_dh_alua.c
+++ b/drivers/scsi/device_handler/scsi_dh_alua.c
@@ -1,7 +1,7 @@
/*
* Generic SCSI-3 ALUA SCSI Device Handler
*
- * Copyright (C) 2007, 2008 Hannes Reinecke, SUSE Linux Products GmbH.
+ * Copyright (C) 2007-2010 Hannes Reinecke, SUSE Linux Products GmbH.
* All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
@@ -20,17 +20,19 @@
*
*/
#include <linux/slab.h>
+#include <linux/delay.h>
#include <scsi/scsi.h>
#include <scsi/scsi_eh.h>
#include <scsi/scsi_dh.h>
#define ALUA_DH_NAME "alua"
-#define ALUA_DH_VER "1.2"
+#define ALUA_DH_VER "1.3"
#define TPGS_STATE_OPTIMIZED 0x0
#define TPGS_STATE_NONOPTIMIZED 0x1
#define TPGS_STATE_STANDBY 0x2
#define TPGS_STATE_UNAVAILABLE 0x3
+#define TPGS_STATE_LBA_DEPENDENT 0x4
#define TPGS_STATE_OFFLINE 0xe
#define TPGS_STATE_TRANSITIONING 0xf
@@ -39,6 +41,7 @@
#define TPGS_SUPPORT_NONOPTIMIZED 0x02
#define TPGS_SUPPORT_STANDBY 0x04
#define TPGS_SUPPORT_UNAVAILABLE 0x08
+#define TPGS_SUPPORT_LBA_DEPENDENT 0x10
#define TPGS_SUPPORT_OFFLINE 0x40
#define TPGS_SUPPORT_TRANSITION 0x80
@@ -460,6 +463,8 @@ static char print_alua_state(int state)
return 'S';
case TPGS_STATE_UNAVAILABLE:
return 'U';
+ case TPGS_STATE_LBA_DEPENDENT:
+ return 'L';
case TPGS_STATE_OFFLINE:
return 'O';
case TPGS_STATE_TRANSITIONING:
@@ -542,7 +547,9 @@ static int alua_rtpg(struct scsi_device *sdev, struct alua_dh_data *h)
int len, k, off, valid_states = 0;
char *ucp;
unsigned err;
+ unsigned long expiry, interval = 10;
+ expiry = round_jiffies_up(jiffies + ALUA_FAILOVER_TIMEOUT);
retry:
err = submit_rtpg(sdev, h);
@@ -553,7 +560,7 @@ static int alua_rtpg(struct scsi_device *sdev, struct alua_dh_data *h)
return SCSI_DH_IO;
err = alua_check_sense(sdev, &sense_hdr);
- if (err == ADD_TO_MLQUEUE)
+ if (err == ADD_TO_MLQUEUE && time_before(jiffies, expiry))
goto retry;
sdev_printk(KERN_INFO, sdev,
"%s: rtpg sense code %02x/%02x/%02x\n",
@@ -587,38 +594,37 @@ static int alua_rtpg(struct scsi_device *sdev, struct alua_dh_data *h)
}
sdev_printk(KERN_INFO, sdev,
- "%s: port group %02x state %c supports %c%c%c%c%c%c\n",
+ "%s: port group %02x state %c supports %c%c%c%c%c%c%c\n",
ALUA_DH_NAME, h->group_id, print_alua_state(h->state),
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');
- if (h->tpgs & TPGS_MODE_EXPLICIT) {
- switch (h->state) {
- case TPGS_STATE_TRANSITIONING:
+ switch (h->state) {
+ case TPGS_STATE_TRANSITIONING:
+ if (time_before(jiffies, expiry)) {
/* State transition, retry */
+ interval *= 10;
+ msleep(interval);
goto retry;
- break;
- case TPGS_STATE_OFFLINE:
- /* Path is offline, fail */
- err = SCSI_DH_DEV_OFFLINED;
- break;
- default:
- break;
}
- } else {
- /* Only Implicit ALUA support */
- if (h->state == TPGS_STATE_OPTIMIZED ||
- h->state == TPGS_STATE_NONOPTIMIZED ||
- h->state == TPGS_STATE_STANDBY)
- /* Useable path if active */
- err = SCSI_DH_OK;
- else
- /* Path unuseable for unavailable/offline */
- err = SCSI_DH_DEV_OFFLINED;
+ /* Transitioning time exceeded, set port to standby */
+ err = SCSI_DH_RETRY;
+ h->state = TPGS_STATE_STANDBY;
+ break;
+ case TPGS_STATE_OFFLINE:
+ case TPGS_STATE_UNAVAILABLE:
+ /* Path unuseable for unavailable/offline */
+ err = SCSI_DH_DEV_OFFLINED;
+ break;
+ default:
+ /* Useable path if active */
+ err = SCSI_DH_OK;
+ break;
}
return err;
}
@@ -672,7 +678,9 @@ static int alua_activate(struct scsi_device *sdev,
goto out;
}
- if (h->tpgs & TPGS_MODE_EXPLICIT && h->state != TPGS_STATE_OPTIMIZED) {
+ if (h->tpgs & TPGS_MODE_EXPLICIT &&
+ h->state != TPGS_STATE_OPTIMIZED &&
+ h->state != TPGS_STATE_LBA_DEPENDENT) {
h->callback_fn = fn;
h->callback_data = data;
err = submit_stpg(h);
@@ -698,8 +706,11 @@ static int alua_prep_fn(struct scsi_device *sdev, struct request *req)
struct alua_dh_data *h = get_alua_data(sdev);
int ret = BLKPREP_OK;
- if (h->state != TPGS_STATE_OPTIMIZED &&
- h->state != TPGS_STATE_NONOPTIMIZED) {
+ if (h->state == TPGS_STATE_TRANSITIONING)
+ ret = BLKPREP_DEFER;
+ else if (h->state != TPGS_STATE_OPTIMIZED &&
+ h->state != TPGS_STATE_NONOPTIMIZED &&
+ h->state != TPGS_STATE_LBA_DEPENDENT) {
ret = BLKPREP_KILL;
req->cmd_flags |= REQ_QUIET;
}
--
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