Make the activate function asynchronous by using blk_execute_rq_nowait()
Signed-off-by: Chandra Seetharaman <sekharan@xxxxxxxxxx>
---
drivers/scsi/device_handler/scsi_dh_alua.c | 132 ++++++++++++++++-------------
1 file changed, 73 insertions(+), 59 deletions(-)
Index: linux-2.6.32-rc5/drivers/scsi/device_handler/scsi_dh_alua.c
===================================================================
--- linux-2.6.32-rc5.orig/drivers/scsi/device_handler/scsi_dh_alua.c 2009-10-20 18:26:14.000000000 -0700
+++ linux-2.6.32-rc5/drivers/scsi/device_handler/scsi_dh_alua.c 2009-10-20 18:27:12.000000000 -0700
@@ -60,11 +60,17 @@
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;
@@ -231,18 +237,71 @@
}
/*
+ * 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 @@
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 @@
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;
}
@@ -477,50 +528,6 @@
}
/*
- * 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 @@
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 @@
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)
--
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