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[SCSI] scsi_dh: Make alua hardware handler's activate() async 

Make the activate function asynchronous by using blk_execute_rq_nowait()

Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
This commit is contained in:
Chandra Seetharaman 2009-10-21 09:23:04 -07:00 committed by James Bottomley
parent 4e2ef86cd5
commit 96e6586556
1 changed files with 73 additions and 59 deletions
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132
drivers/scsi/device_handler/scsi_dh_alua.c
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@ -60,11 +60,17 @@ struct alua_dh_data {
int bufflen;
unsigned char sense[SCSI_SENSE_BUFFERSIZE];
int senselen;
struct scsi_device *sdev;
activate_complete callback_fn;
void *callback_data;
};
#define ALUA_POLICY_SWITCH_CURRENT 0
#define ALUA_POLICY_SWITCH_ALL 1
static char print_alua_state(int);
static int alua_check_sense(struct scsi_device *, struct scsi_sense_hdr *);
static inline struct alua_dh_data *get_alua_data(struct scsi_device *sdev)
{
struct scsi_dh_data *scsi_dh_data = sdev->scsi_dh_data;
@ -230,19 +236,72 @@ done:
return err;
}
/*
* 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_IO;
if (error || host_byte(req->errors) != DID_OK ||
msg_byte(req->errors) != COMMAND_COMPLETE)
goto done;
if (err == SCSI_DH_IO && h->senselen > 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;
}
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:
blk_put_request(req);
if (h->callback_fn) {
h->callback_fn(h->callback_data, err);
h->callback_fn = h->callback_data = NULL;
}
return;
}
/*
* submit_stpg - Issue a SET TARGET GROUP STATES command
* @sdev: sdev the command should be sent to
*
* Currently we're only setting the current target port group state
* to 'active/optimized' and let the array firmware figure out
* the states of the remaining groups.
*/
static unsigned submit_stpg(struct scsi_device *sdev, struct alua_dh_data *h)
static unsigned submit_stpg(struct alua_dh_data *h)
{
struct request *rq;
int err = SCSI_DH_RES_TEMP_UNAVAIL;
int stpg_len = 8;
struct scsi_device *sdev = h->sdev;
/* Prepare the data buffer */
memset(h->buff, 0, stpg_len);
@ -252,7 +311,7 @@ static unsigned submit_stpg(struct scsi_device *sdev, struct alua_dh_data *h)
rq = get_alua_req(sdev, h->buff, stpg_len, WRITE);
if (!rq)
goto done;
return SCSI_DH_RES_TEMP_UNAVAIL;
/* Prepare the command. */
rq->cmd[0] = MAINTENANCE_OUT;
@ -266,17 +325,9 @@ static unsigned submit_stpg(struct scsi_device *sdev, struct alua_dh_data *h)
rq->sense = h->sense;
memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE);
rq->sense_len = h->senselen = 0;
rq->end_io_data = h;
err = blk_execute_rq(rq->q, NULL, rq, 1);
if (err == -EIO) {
sdev_printk(KERN_INFO, sdev,
"%s: stpg failed with %x\n",
ALUA_DH_NAME, rq->errors);
h->senselen = rq->sense_len;
err = SCSI_DH_IO;
}
blk_put_request(rq);
done:
blk_execute_rq_nowait(rq->q, NULL, rq, 1, stpg_endio);
return err;
}
@ -476,50 +527,6 @@ static int alua_check_sense(struct scsi_device *sdev,
return SCSI_RETURN_NOT_HANDLED;
}
/*
* 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 int alua_stpg(struct scsi_device *sdev, int state,
struct alua_dh_data *h)
{
struct scsi_sense_hdr sense_hdr;
unsigned err;
int retry = ALUA_FAILOVER_RETRIES;
retry:
err = submit_stpg(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 (retry > 0 && err == ADD_TO_MLQUEUE) {
retry--;
goto retry;
}
sdev_printk(KERN_INFO, 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;
}
if (err == SCSI_DH_OK) {
h->state = state;
sdev_printk(KERN_INFO, sdev,
"%s: port group %02x switched to state %c\n",
ALUA_DH_NAME, h->group_id,
print_alua_state(h->state) );
}
return err;
}
/*
* alua_rtpg - Evaluate REPORT TARGET GROUP STATES
* @sdev: the device to be evaluated.
@ -664,8 +671,14 @@ static int alua_activate(struct scsi_device *sdev,
goto out;
}
if (h->tpgs & TPGS_MODE_EXPLICIT && h->state != TPGS_STATE_OPTIMIZED)
err = alua_stpg(sdev, TPGS_STATE_OPTIMIZED, h);
if (h->tpgs & TPGS_MODE_EXPLICIT && h->state != TPGS_STATE_OPTIMIZED) {
h->callback_fn = fn;
h->callback_data = data;
err = submit_stpg(h);
if (err == SCSI_DH_OK)
return 0;
h->callback_fn = h->callback_data = NULL;
}
out:
if (fn)
@ -748,6 +761,7 @@ static int alua_bus_attach(struct scsi_device *sdev)
h->rel_port = -1;
h->buff = h->inq;
h->bufflen = ALUA_INQUIRY_SIZE;
h->sdev = sdev;
err = alua_initialize(sdev, h);
if (err != SCSI_DH_OK)