From 96e6586556dfa80112f42895be93c561582d9930 Mon Sep 17 00:00:00 2001 From: Chandra Seetharaman Date: Wed, 21 Oct 2009 09:23:04 -0700 Subject: [PATCH] [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 Signed-off-by: James Bottomley --- drivers/scsi/device_handler/scsi_dh_alua.c | 132 ++++++++++++--------- 1 file changed, 73 insertions(+), 59 deletions(-) diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c b/drivers/scsi/device_handler/scsi_dh_alua.c index e8a8928e58bc..4f0d0138f48b 100644 --- a/drivers/scsi/device_handler/scsi_dh_alua.c +++ b/drivers/scsi/device_handler/scsi_dh_alua.c @@ -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)