/*
* alua_stpg - Evaluate SET TARGET GROUP STATES
* @sdev: the device to be evaluated
* @state: the new target group state
*
* Send a SET TARGET GROUP STATES command to the device.
* We only have to test here if we should resubmit the command;
* any other error is assumed as a failure.
*/
static void stpg_endio(struct request *req, int error)
{
struct alua_dh_data *h = req->end_io_data;
struct scsi_sense_hdr sense_hdr;
unsigned err = SCSI_DH_OK;
if (host_byte(req->errors) != DID_OK ||
msg_byte(req->errors) != COMMAND_COMPLETE) {
err = SCSI_DH_IO;
goto done;
}
if (req->sense_len > 0) {
err = scsi_normalize_sense(h->sense, SCSI_SENSE_BUFFERSIZE,
&sense_hdr);
if (!err) {
err = SCSI_DH_IO;
goto done;
}
err = alua_check_sense(h->sdev, &sense_hdr);
if (err == ADD_TO_MLQUEUE) {
err = SCSI_DH_RETRY;
goto done;
}
sdev_printk(KERN_INFO, h->sdev,
"%s: stpg sense code: %02x/%02x/%02x\n",
ALUA_DH_NAME, sense_hdr.sense_key,
sense_hdr.asc, sense_hdr.ascq);
err = SCSI_DH_IO;
} else if (error)
err = SCSI_DH_IO;
if (err == SCSI_DH_OK) {
h->state = TPGS_STATE_OPTIMIZED;
sdev_printk(KERN_INFO, h->sdev,
"%s: port group %02x switched to state %c\n",
ALUA_DH_NAME, h->group_id,
print_alua_state(h->state));
}
done:
req->end_io_data = NULL;
__blk_put_request(req->q, req);
if (h->callback_fn) {
h->callback_fn(h->callback_data, err);
h->callback_fn = h->callback_data = NULL;
}
return;
}
/*
* stpg_endio - Evaluate SET TARGET GROUP STATES
* @sdev: the device to be evaluated
* @state: the new target group state
*
* Evaluate a SET TARGET GROUP STATES command response.
*/
static void stpg_endio(struct request *req, int error)
{
struct alua_dh_data *h = req->end_io_data;
struct scsi_sense_hdr sense_hdr;
unsigned err = SCSI_DH_OK;
if (host_byte(req->errors) != DID_OK ||
msg_byte(req->errors) != COMMAND_COMPLETE) {
err = SCSI_DH_IO;
goto done;
}
if (scsi_normalize_sense(h->sense, SCSI_SENSE_BUFFERSIZE,
&sense_hdr)) {
if (sense_hdr.sense_key == NOT_READY &&
sense_hdr.asc == 0x04 && sense_hdr.ascq == 0x0a) {
/* ALUA state transition already in progress */
err = SCSI_DH_OK;
goto done;
}
if (sense_hdr.sense_key == UNIT_ATTENTION) {
err = SCSI_DH_RETRY;
goto done;
}
sdev_printk(KERN_INFO, h->sdev, "%s: stpg failed\n",
ALUA_DH_NAME);
scsi_print_sense_hdr(h->sdev, ALUA_DH_NAME, &sense_hdr);
err = SCSI_DH_IO;
} else if (error)
err = SCSI_DH_IO;
if (err == SCSI_DH_OK) {
h->state = TPGS_STATE_OPTIMIZED;
sdev_printk(KERN_INFO, h->sdev,
"%s: port group %02x switched to state %c\n",
ALUA_DH_NAME, h->group_id,
print_alua_state(h->state));
}
done:
req->end_io_data = NULL;
__blk_put_request(req->q, req);
if (h->callback_fn) {
h->callback_fn(h->callback_data, err);
h->callback_fn = h->callback_data = NULL;
}
return;
}
for (k = tpg_desc_tbl_off, ucp = h->buff + tpg_desc_tbl_off;
k < len;
k += off, ucp += off) {
if (h->group_id == get_unaligned_be16(&ucp[2])) {
h->state = ucp[0] & 0x0f;
h->pref = ucp[0] >> 7;
valid_states = ucp[1];
}
off = 8 + (ucp[7] * 4);
}
sdev_printk(KERN_INFO, sdev,
"%s: port group %02x state %c %s supports %c%c%c%c%c%c%c\n",
ALUA_DH_NAME, h->group_id, print_alua_state(h->state),
h->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');
switch (h->state) {
case TPGS_STATE_TRANSITIONING:
if (wait_for_transition) {
if (time_before(jiffies, expiry)) {
/* State transition, retry */
interval += 2000;
/*
* alua_rtpg - Evaluate REPORT TARGET GROUP STATES
* @sdev: the device to be evaluated.
*
* Evaluate the Target Port Group State.
* Returns SCSI_DH_DEV_OFFLINED if the path is
* found to be unuseable.
*/
static int alua_rtpg(struct scsi_device *sdev, struct alua_dh_data *h)
{
struct scsi_sense_hdr sense_hdr;
int len, k, off, valid_states = 0;
unsigned char *ucp;
unsigned err;
unsigned long expiry, interval = 10;
expiry = round_jiffies_up(jiffies + ALUA_FAILOVER_TIMEOUT);
retry:
err = submit_rtpg(sdev, h);
if (err == SCSI_DH_IO && h->senselen > 0) {
err = scsi_normalize_sense(h->sense, SCSI_SENSE_BUFFERSIZE,
&sense_hdr);
if (!err)
return SCSI_DH_IO;
err = alua_check_sense(sdev, &sense_hdr);
if (err == ADD_TO_MLQUEUE && time_before(jiffies, expiry))
goto retry;
sdev_printk(KERN_INFO, sdev,
"%s: rtpg sense code %02x/%02x/%02x\n",
ALUA_DH_NAME, sense_hdr.sense_key,
sense_hdr.asc, sense_hdr.ascq);
err = SCSI_DH_IO;
}
if (err != SCSI_DH_OK)
return err;
len = (h->buff[0] << 24) + (h->buff[1] << 16) +
(h->buff[2] << 8) + h->buff[3] + 4;
if (len > h->bufflen) {
/* Resubmit with the correct length */
if (realloc_buffer(h, len)) {
sdev_printk(KERN_WARNING, sdev,
"%s: kmalloc buffer failed\n",__func__);
/* Temporary failure, bypass */
return SCSI_DH_DEV_TEMP_BUSY;
}
goto retry;
}
for (k = 4, ucp = h->buff + 4; k < len; k += off, ucp += off) {
if (h->group_id == (ucp[2] << 8) + ucp[3]) {
h->state = ucp[0] & 0x0f;
valid_states = ucp[1];
}
off = 8 + (ucp[7] * 4);
}
sdev_printk(KERN_INFO, sdev,
"%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');
switch (h->state) {
case TPGS_STATE_TRANSITIONING:
if (time_before(jiffies, expiry)) {
/* State transition, retry */
interval *= 10;
msleep(interval);
goto retry;
}
/* 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;
}
/*
* alua_rtpg - Evaluate REPORT TARGET GROUP STATES
* @sdev: the device to be evaluated.
*
* Evaluate the Target Port Group State.
* Returns SCSI_DH_DEV_OFFLINED if the path is
* found to be unuseable.
*/
static int alua_rtpg(struct scsi_device *sdev, struct alua_dh_data *h)
{
struct scsi_sense_hdr sense_hdr;
int len, k, off, valid_states = 0;
char *ucp;
unsigned err;
retry:
err = submit_rtpg(sdev, h);
if (err == SCSI_DH_IO && h->senselen > 0) {
err = scsi_normalize_sense(h->sense, SCSI_SENSE_BUFFERSIZE,
&sense_hdr);
if (!err)
return SCSI_DH_IO;
err = alua_check_sense(sdev, &sense_hdr);
if (err == ADD_TO_MLQUEUE)
goto retry;
sdev_printk(KERN_INFO, sdev,
"%s: rtpg sense code %02x/%02x/%02x\n",
ALUA_DH_NAME, sense_hdr.sense_key,
sense_hdr.asc, sense_hdr.ascq);
err = SCSI_DH_IO;
}
if (err != SCSI_DH_OK)
return err;
len = (h->buff[0] << 24) + (h->buff[1] << 16) +
(h->buff[2] << 8) + h->buff[3] + 4;
if (len > h->bufflen) {
/* Resubmit with the correct length */
if (realloc_buffer(h, len)) {
sdev_printk(KERN_WARNING, sdev,
"%s: kmalloc buffer failed\n",__func__);
/* Temporary failure, bypass */
return SCSI_DH_DEV_TEMP_BUSY;
}
goto retry;
}
for (k = 4, ucp = h->buff + 4; k < len; k += off, ucp += off) {
if (h->group_id == (ucp[2] << 8) + ucp[3]) {
h->state = ucp[0] & 0x0f;
valid_states = ucp[1];
}
off = 8 + (ucp[7] * 4);
}
sdev_printk(KERN_INFO, sdev,
"%s: port group %02x state %c supports %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_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:
/* State transition, retry */
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;
}
return err;
}
