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Commit 96e65865 authored by Chandra Seetharaman's avatar Chandra Seetharaman Committed by James Bottomley
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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: default avatarChandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@suse.de>
parent 4e2ef86c

drivers/scsi/device_handler/scsi_dh_alua.c

+73 −59
Original line number Diff line number Diff line
@@ -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 @@ static unsigned submit_rtpg(struct scsi_device *sdev, struct alua_dh_data *h) 
	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)