2 * Engenio/LSI RDAC SCSI Device Handler
4 * Copyright (C) 2005 Mike Christie. All rights reserved.
5 * Copyright (C) Chandra Seetharaman, IBM Corp. 2007
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
22 #include <scsi/scsi.h>
23 #include <scsi/scsi_eh.h>
24 #include <scsi/scsi_dh.h>
25 #include <linux/workqueue.h>
26 #include <linux/slab.h>
28 #define RDAC_NAME "rdac"
29 #define RDAC_RETRY_COUNT 5
34 * These struct definitions and the forming of the
35 * mode page were taken from the LSI RDAC 2.4 GPL'd
36 * driver, and then converted to Linux conventions.
38 #define RDAC_QUIESCENCE_TIME 20;
42 #define RDAC_PAGE_CODE_REDUNDANT_CONTROLLER 0x2c
45 * Controller modes definitions
47 #define RDAC_MODE_TRANSFER_SPECIFIED_LUNS 0x02
52 #define RDAC_FORCED_QUIESENCE 0x02
54 #define RDAC_TIMEOUT (60 * HZ)
55 #define RDAC_RETRIES 3
57 struct rdac_mode_6_hdr {
64 struct rdac_mode_10_hdr {
72 struct rdac_mode_common {
73 u8 controller_serial[16];
74 u8 alt_controller_serial[16];
77 u8 quiescence_timeout;
81 struct rdac_pg_legacy {
82 struct rdac_mode_6_hdr hdr;
85 struct rdac_mode_common common;
86 #define MODE6_MAX_LUN 32
87 u8 lun_table[MODE6_MAX_LUN];
93 struct rdac_pg_expanded {
94 struct rdac_mode_10_hdr hdr;
98 struct rdac_mode_common common;
106 u8 page_code; /* 0xC9 */
109 u8 page_id[4]; /* "vace" */
115 #define SUBSYS_ID_LEN 16
116 #define SLOT_ID_LEN 2
117 #define ARRAY_LABEL_LEN 31
121 u8 page_code; /* 0xC4 */
124 u8 page_id[4]; /* "subs" */
125 u8 subsys_id[SUBSYS_ID_LEN];
127 u8 slot_id[SLOT_ID_LEN];
131 struct rdac_controller {
132 u8 subsys_id[SUBSYS_ID_LEN];
133 u8 slot_id[SLOT_ID_LEN];
136 struct list_head node; /* list of all controllers */
138 struct rdac_pg_legacy legacy;
139 struct rdac_pg_expanded expanded;
142 u8 array_name[ARRAY_LABEL_LEN];
145 struct work_struct ms_work;
146 struct scsi_device *ms_sdev;
147 struct list_head ms_head;
152 u8 page_code; /* 0xC8 */
155 u8 page_id[4]; /* "edid" */
159 u8 vol_user_label_len;
160 u8 vol_user_label[60];
161 u8 array_uniq_id_len;
162 u8 array_unique_id[16];
163 u8 array_user_label_len;
164 u8 array_user_label[60];
170 u8 page_code; /* 0xC2 */
173 u8 page_id[4]; /* "swr4" */
177 u8 max_lun_supported;
178 u8 partitions[239]; /* Total allocation length should be 0xFF */
181 struct rdac_dh_data {
182 struct rdac_controller *ctlr;
183 #define UNINITIALIZED_LUN (1 << 8)
185 #define RDAC_STATE_ACTIVE 0
186 #define RDAC_STATE_PASSIVE 1
189 #define RDAC_LUN_UNOWNED 0
190 #define RDAC_LUN_OWNED 1
191 #define RDAC_LUN_AVT 2
193 unsigned char sense[SCSI_SENSE_BUFFERSIZE];
195 struct c2_inquiry c2;
196 struct c4_inquiry c4;
197 struct c8_inquiry c8;
198 struct c9_inquiry c9;
202 static const char *lun_state[] =
209 struct rdac_queue_data {
210 struct list_head entry;
211 struct rdac_dh_data *h;
212 activate_complete callback_fn;
216 static LIST_HEAD(ctlr_list);
217 static DEFINE_SPINLOCK(list_lock);
218 static struct workqueue_struct *kmpath_rdacd;
219 static void send_mode_select(struct work_struct *work);
222 * module parameter to enable rdac debug logging.
223 * 2 bits for each type of logging, only two types defined for now
224 * Can be enhanced if required at later point
226 static int rdac_logging = 1;
227 module_param(rdac_logging, int, S_IRUGO|S_IWUSR);
228 MODULE_PARM_DESC(rdac_logging, "A bit mask of rdac logging levels, "
229 "Default is 1 - failover logging enabled, "
230 "set it to 0xF to enable all the logs");
232 #define RDAC_LOG_FAILOVER 0
233 #define RDAC_LOG_SENSE 2
235 #define RDAC_LOG_BITS 2
237 #define RDAC_LOG_LEVEL(SHIFT) \
238 ((rdac_logging >> (SHIFT)) & ((1 << (RDAC_LOG_BITS)) - 1))
240 #define RDAC_LOG(SHIFT, sdev, f, arg...) \
242 if (unlikely(RDAC_LOG_LEVEL(SHIFT))) \
243 sdev_printk(KERN_INFO, sdev, RDAC_NAME ": " f "\n", ## arg); \
246 static inline struct rdac_dh_data *get_rdac_data(struct scsi_device *sdev)
248 struct scsi_dh_data *scsi_dh_data = sdev->scsi_dh_data;
249 BUG_ON(scsi_dh_data == NULL);
250 return ((struct rdac_dh_data *) scsi_dh_data->buf);
253 static struct request *get_rdac_req(struct scsi_device *sdev,
254 void *buffer, unsigned buflen, int rw)
257 struct request_queue *q = sdev->request_queue;
259 rq = blk_get_request(q, rw, GFP_NOIO);
262 sdev_printk(KERN_INFO, sdev,
263 "get_rdac_req: blk_get_request failed.\n");
267 if (buflen && blk_rq_map_kern(q, rq, buffer, buflen, GFP_NOIO)) {
269 sdev_printk(KERN_INFO, sdev,
270 "get_rdac_req: blk_rq_map_kern failed.\n");
274 rq->cmd_type = REQ_TYPE_BLOCK_PC;
275 rq->cmd_flags |= REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT |
277 rq->retries = RDAC_RETRIES;
278 rq->timeout = RDAC_TIMEOUT;
283 static struct request *rdac_failover_get(struct scsi_device *sdev,
284 struct rdac_dh_data *h)
287 struct rdac_mode_common *common;
290 if (h->ctlr->use_ms10) {
291 struct rdac_pg_expanded *rdac_pg;
293 data_size = sizeof(struct rdac_pg_expanded);
294 rdac_pg = &h->ctlr->mode_select.expanded;
295 memset(rdac_pg, 0, data_size);
296 common = &rdac_pg->common;
297 rdac_pg->page_code = RDAC_PAGE_CODE_REDUNDANT_CONTROLLER + 0x40;
298 rdac_pg->subpage_code = 0x1;
299 rdac_pg->page_len[0] = 0x01;
300 rdac_pg->page_len[1] = 0x28;
302 struct rdac_pg_legacy *rdac_pg;
304 data_size = sizeof(struct rdac_pg_legacy);
305 rdac_pg = &h->ctlr->mode_select.legacy;
306 memset(rdac_pg, 0, data_size);
307 common = &rdac_pg->common;
308 rdac_pg->page_code = RDAC_PAGE_CODE_REDUNDANT_CONTROLLER;
309 rdac_pg->page_len = 0x68;
311 common->rdac_mode[1] = RDAC_MODE_TRANSFER_SPECIFIED_LUNS;
312 common->quiescence_timeout = RDAC_QUIESCENCE_TIME;
313 common->rdac_options = RDAC_FORCED_QUIESENCE;
315 /* get request for block layer packet command */
316 rq = get_rdac_req(sdev, &h->ctlr->mode_select, data_size, WRITE);
320 /* Prepare the command. */
321 if (h->ctlr->use_ms10) {
322 rq->cmd[0] = MODE_SELECT_10;
323 rq->cmd[7] = data_size >> 8;
324 rq->cmd[8] = data_size & 0xff;
326 rq->cmd[0] = MODE_SELECT;
327 rq->cmd[4] = data_size;
329 rq->cmd_len = COMMAND_SIZE(rq->cmd[0]);
331 rq->sense = h->sense;
332 memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE);
338 static void release_controller(struct kref *kref)
340 struct rdac_controller *ctlr;
341 ctlr = container_of(kref, struct rdac_controller, kref);
343 flush_workqueue(kmpath_rdacd);
344 spin_lock(&list_lock);
345 list_del(&ctlr->node);
346 spin_unlock(&list_lock);
350 static struct rdac_controller *get_controller(u8 *subsys_id, u8 *slot_id,
353 struct rdac_controller *ctlr, *tmp;
355 spin_lock(&list_lock);
357 list_for_each_entry(tmp, &ctlr_list, node) {
358 if ((memcmp(tmp->subsys_id, subsys_id, SUBSYS_ID_LEN) == 0) &&
359 (memcmp(tmp->slot_id, slot_id, SLOT_ID_LEN) == 0)) {
360 kref_get(&tmp->kref);
361 spin_unlock(&list_lock);
365 ctlr = kmalloc(sizeof(*ctlr), GFP_ATOMIC);
369 /* initialize fields of controller */
370 memcpy(ctlr->subsys_id, subsys_id, SUBSYS_ID_LEN);
371 memcpy(ctlr->slot_id, slot_id, SLOT_ID_LEN);
372 memcpy(ctlr->array_name, array_name, ARRAY_LABEL_LEN);
374 /* update the controller index */
375 if (slot_id[1] == 0x31)
380 kref_init(&ctlr->kref);
383 ctlr->ms_sdev = NULL;
384 spin_lock_init(&ctlr->ms_lock);
385 INIT_WORK(&ctlr->ms_work, send_mode_select);
386 INIT_LIST_HEAD(&ctlr->ms_head);
387 list_add(&ctlr->node, &ctlr_list);
389 spin_unlock(&list_lock);
393 static int submit_inquiry(struct scsi_device *sdev, int page_code,
394 unsigned int len, struct rdac_dh_data *h)
397 struct request_queue *q = sdev->request_queue;
398 int err = SCSI_DH_RES_TEMP_UNAVAIL;
400 rq = get_rdac_req(sdev, &h->inq, len, READ);
404 /* Prepare the command. */
405 rq->cmd[0] = INQUIRY;
407 rq->cmd[2] = page_code;
409 rq->cmd_len = COMMAND_SIZE(INQUIRY);
411 rq->sense = h->sense;
412 memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE);
415 err = blk_execute_rq(q, NULL, rq, 1);
424 static int get_lun_info(struct scsi_device *sdev, struct rdac_dh_data *h,
428 struct c8_inquiry *inqp;
430 err = submit_inquiry(sdev, 0xC8, sizeof(struct c8_inquiry), h);
431 if (err == SCSI_DH_OK) {
433 if (inqp->page_code != 0xc8)
434 return SCSI_DH_NOSYS;
435 if (inqp->page_id[0] != 'e' || inqp->page_id[1] != 'd' ||
436 inqp->page_id[2] != 'i' || inqp->page_id[3] != 'd')
437 return SCSI_DH_NOSYS;
438 h->lun = inqp->lun[7]; /* Uses only the last byte */
440 for(i=0; i<ARRAY_LABEL_LEN-1; ++i)
441 *(array_name+i) = inqp->array_user_label[(2*i)+1];
443 *(array_name+ARRAY_LABEL_LEN-1) = '\0';
448 static int check_ownership(struct scsi_device *sdev, struct rdac_dh_data *h)
451 struct c9_inquiry *inqp;
453 h->lun_state = RDAC_LUN_UNOWNED;
454 h->state = RDAC_STATE_ACTIVE;
455 err = submit_inquiry(sdev, 0xC9, sizeof(struct c9_inquiry), h);
456 if (err == SCSI_DH_OK) {
458 if ((inqp->avte_cvp >> 7) == 0x1) {
459 /* LUN in AVT mode */
460 sdev_printk(KERN_NOTICE, sdev,
461 "%s: AVT mode detected\n",
463 h->lun_state = RDAC_LUN_AVT;
464 } else if ((inqp->avte_cvp & 0x1) != 0) {
465 /* LUN was owned by the controller */
466 h->lun_state = RDAC_LUN_OWNED;
470 if (h->lun_state == RDAC_LUN_UNOWNED)
471 h->state = RDAC_STATE_PASSIVE;
476 static int initialize_controller(struct scsi_device *sdev,
477 struct rdac_dh_data *h, char *array_name)
480 struct c4_inquiry *inqp;
482 err = submit_inquiry(sdev, 0xC4, sizeof(struct c4_inquiry), h);
483 if (err == SCSI_DH_OK) {
485 h->ctlr = get_controller(inqp->subsys_id, inqp->slot_id,
488 err = SCSI_DH_RES_TEMP_UNAVAIL;
493 static int set_mode_select(struct scsi_device *sdev, struct rdac_dh_data *h)
496 struct c2_inquiry *inqp;
498 err = submit_inquiry(sdev, 0xC2, sizeof(struct c2_inquiry), h);
499 if (err == SCSI_DH_OK) {
502 * If more than MODE6_MAX_LUN luns are supported, use
505 if (inqp->max_lun_supported >= MODE6_MAX_LUN)
506 h->ctlr->use_ms10 = 1;
508 h->ctlr->use_ms10 = 0;
513 static int mode_select_handle_sense(struct scsi_device *sdev,
514 unsigned char *sensebuf)
516 struct scsi_sense_hdr sense_hdr;
517 int err = SCSI_DH_IO, ret;
518 struct rdac_dh_data *h = get_rdac_data(sdev);
520 ret = scsi_normalize_sense(sensebuf, SCSI_SENSE_BUFFERSIZE, &sense_hdr);
524 switch (sense_hdr.sense_key) {
526 case ABORTED_COMMAND:
531 if (sense_hdr.asc == 0x04 && sense_hdr.ascq == 0x01)
532 /* LUN Not Ready and is in the Process of Becoming
537 case ILLEGAL_REQUEST:
538 if (sense_hdr.asc == 0x91 && sense_hdr.ascq == 0x36)
540 * Command Lock contention
548 RDAC_LOG(RDAC_LOG_FAILOVER, sdev, "array %s, ctlr %d, "
549 "MODE_SELECT returned with sense %02x/%02x/%02x",
550 (char *) h->ctlr->array_name, h->ctlr->index,
551 sense_hdr.sense_key, sense_hdr.asc, sense_hdr.ascq);
557 static void send_mode_select(struct work_struct *work)
559 struct rdac_controller *ctlr =
560 container_of(work, struct rdac_controller, ms_work);
562 struct scsi_device *sdev = ctlr->ms_sdev;
563 struct rdac_dh_data *h = get_rdac_data(sdev);
564 struct request_queue *q = sdev->request_queue;
565 int err, retry_cnt = RDAC_RETRY_COUNT;
566 struct rdac_queue_data *tmp, *qdata;
570 spin_lock(&ctlr->ms_lock);
571 list_splice_init(&ctlr->ms_head, &list);
573 ctlr->ms_sdev = NULL;
574 spin_unlock(&ctlr->ms_lock);
577 lun_table = ctlr->mode_select.expanded.lun_table;
579 lun_table = ctlr->mode_select.legacy.lun_table;
582 err = SCSI_DH_RES_TEMP_UNAVAIL;
583 rq = rdac_failover_get(sdev, h);
587 list_for_each_entry(qdata, &list, entry) {
588 lun_table[qdata->h->lun] = 0x81;
591 RDAC_LOG(RDAC_LOG_FAILOVER, sdev, "array %s, ctlr %d, "
592 "%s MODE_SELECT command",
593 (char *) h->ctlr->array_name, h->ctlr->index,
594 (retry_cnt == RDAC_RETRY_COUNT) ? "queueing" : "retrying");
596 err = blk_execute_rq(q, NULL, rq, 1);
598 if (err != SCSI_DH_OK) {
599 err = mode_select_handle_sense(sdev, h->sense);
600 if (err == SCSI_DH_RETRY && retry_cnt--)
603 if (err == SCSI_DH_OK) {
604 h->state = RDAC_STATE_ACTIVE;
605 RDAC_LOG(RDAC_LOG_FAILOVER, sdev, "array %s, ctlr %d, "
606 "MODE_SELECT completed",
607 (char *) h->ctlr->array_name, h->ctlr->index);
611 list_for_each_entry_safe(qdata, tmp, &list, entry) {
612 list_del(&qdata->entry);
613 if (err == SCSI_DH_OK)
614 qdata->h->state = RDAC_STATE_ACTIVE;
615 if (qdata->callback_fn)
616 qdata->callback_fn(qdata->callback_data, err);
622 static int queue_mode_select(struct scsi_device *sdev,
623 activate_complete fn, void *data)
625 struct rdac_queue_data *qdata;
626 struct rdac_controller *ctlr;
628 qdata = kzalloc(sizeof(*qdata), GFP_KERNEL);
630 return SCSI_DH_RETRY;
632 qdata->h = get_rdac_data(sdev);
633 qdata->callback_fn = fn;
634 qdata->callback_data = data;
636 ctlr = qdata->h->ctlr;
637 spin_lock(&ctlr->ms_lock);
638 list_add_tail(&qdata->entry, &ctlr->ms_head);
639 if (!ctlr->ms_queued) {
641 ctlr->ms_sdev = sdev;
642 queue_work(kmpath_rdacd, &ctlr->ms_work);
644 spin_unlock(&ctlr->ms_lock);
648 static int rdac_activate(struct scsi_device *sdev,
649 activate_complete fn, void *data)
651 struct rdac_dh_data *h = get_rdac_data(sdev);
652 int err = SCSI_DH_OK;
654 err = check_ownership(sdev, h);
655 if (err != SCSI_DH_OK)
658 if (h->lun_state == RDAC_LUN_UNOWNED) {
659 err = queue_mode_select(sdev, fn, data);
660 if (err == SCSI_DH_OK)
669 static int rdac_prep_fn(struct scsi_device *sdev, struct request *req)
671 struct rdac_dh_data *h = get_rdac_data(sdev);
672 int ret = BLKPREP_OK;
674 if (h->state != RDAC_STATE_ACTIVE) {
676 req->cmd_flags |= REQ_QUIET;
682 static int rdac_check_sense(struct scsi_device *sdev,
683 struct scsi_sense_hdr *sense_hdr)
685 struct rdac_dh_data *h = get_rdac_data(sdev);
687 RDAC_LOG(RDAC_LOG_SENSE, sdev, "array %s, ctlr %d, "
688 "I/O returned with sense %02x/%02x/%02x",
689 (char *) h->ctlr->array_name, h->ctlr->index,
690 sense_hdr->sense_key, sense_hdr->asc, sense_hdr->ascq);
692 switch (sense_hdr->sense_key) {
694 if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x01)
695 /* LUN Not Ready - Logical Unit Not Ready and is in
696 * the process of becoming ready
699 return ADD_TO_MLQUEUE;
700 if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x81)
701 /* LUN Not Ready - Storage firmware incompatible
702 * Manual code synchonisation required.
704 * Nothing we can do here. Try to bypass the path.
707 if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0xA1)
708 /* LUN Not Ready - Quiescense in progress
710 * Just retry and wait.
712 return ADD_TO_MLQUEUE;
713 if (sense_hdr->asc == 0xA1 && sense_hdr->ascq == 0x02)
714 /* LUN Not Ready - Quiescense in progress
715 * or has been achieved
718 return ADD_TO_MLQUEUE;
720 case ILLEGAL_REQUEST:
721 if (sense_hdr->asc == 0x94 && sense_hdr->ascq == 0x01) {
722 /* Invalid Request - Current Logical Unit Ownership.
723 * Controller is not the current owner of the LUN,
724 * Fail the path, so that the other path be used.
726 h->state = RDAC_STATE_PASSIVE;
731 if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00)
733 * Power On, Reset, or Bus Device Reset, just retry.
735 return ADD_TO_MLQUEUE;
736 if (sense_hdr->asc == 0x8b && sense_hdr->ascq == 0x02)
738 * Quiescence in progress , just retry.
740 return ADD_TO_MLQUEUE;
743 /* success just means we do not care what scsi-ml does */
744 return SCSI_RETURN_NOT_HANDLED;
747 static const struct scsi_dh_devlist rdac_dev_list[] = {
761 {"STK", "OPENstorage D280"},
763 {"SUN", "LCSM100_I"},
764 {"SUN", "LCSM100_S"},
765 {"SUN", "LCSM100_E"},
766 {"SUN", "LCSM100_F"},
771 {"LSI", "INF-01-00"},
772 {"ENGENIO", "INF-01-00"},
773 {"STK", "FLEXLINE 380"},
774 {"SUN", "CSM100_R_FC"},
778 static int rdac_bus_attach(struct scsi_device *sdev);
779 static void rdac_bus_detach(struct scsi_device *sdev);
781 static struct scsi_device_handler rdac_dh = {
783 .module = THIS_MODULE,
784 .devlist = rdac_dev_list,
785 .prep_fn = rdac_prep_fn,
786 .check_sense = rdac_check_sense,
787 .attach = rdac_bus_attach,
788 .detach = rdac_bus_detach,
789 .activate = rdac_activate,
792 static int rdac_bus_attach(struct scsi_device *sdev)
794 struct scsi_dh_data *scsi_dh_data;
795 struct rdac_dh_data *h;
798 char array_name[ARRAY_LABEL_LEN];
800 scsi_dh_data = kzalloc(sizeof(struct scsi_device_handler *)
801 + sizeof(*h) , GFP_KERNEL);
803 sdev_printk(KERN_ERR, sdev, "%s: Attach failed\n",
808 scsi_dh_data->scsi_dh = &rdac_dh;
809 h = (struct rdac_dh_data *) scsi_dh_data->buf;
810 h->lun = UNINITIALIZED_LUN;
811 h->state = RDAC_STATE_ACTIVE;
813 err = get_lun_info(sdev, h, array_name);
814 if (err != SCSI_DH_OK)
817 err = initialize_controller(sdev, h, array_name);
818 if (err != SCSI_DH_OK)
821 err = check_ownership(sdev, h);
822 if (err != SCSI_DH_OK)
825 err = set_mode_select(sdev, h);
826 if (err != SCSI_DH_OK)
829 if (!try_module_get(THIS_MODULE))
832 spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
833 sdev->scsi_dh_data = scsi_dh_data;
834 spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
836 sdev_printk(KERN_NOTICE, sdev,
838 RDAC_NAME, h->lun, lun_state[(int)h->lun_state]);
843 kref_put(&h->ctlr->kref, release_controller);
847 sdev_printk(KERN_ERR, sdev, "%s: not attached\n",
852 static void rdac_bus_detach( struct scsi_device *sdev )
854 struct scsi_dh_data *scsi_dh_data;
855 struct rdac_dh_data *h;
858 spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
859 scsi_dh_data = sdev->scsi_dh_data;
860 sdev->scsi_dh_data = NULL;
861 spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
863 h = (struct rdac_dh_data *) scsi_dh_data->buf;
865 kref_put(&h->ctlr->kref, release_controller);
867 module_put(THIS_MODULE);
868 sdev_printk(KERN_NOTICE, sdev, "%s: Detached\n", RDAC_NAME);
873 static int __init rdac_init(void)
877 r = scsi_register_device_handler(&rdac_dh);
879 printk(KERN_ERR "Failed to register scsi device handler.");
884 * Create workqueue to handle mode selects for rdac
886 kmpath_rdacd = create_singlethread_workqueue("kmpath_rdacd");
888 scsi_unregister_device_handler(&rdac_dh);
889 printk(KERN_ERR "kmpath_rdacd creation failed.\n");
895 static void __exit rdac_exit(void)
897 destroy_workqueue(kmpath_rdacd);
898 scsi_unregister_device_handler(&rdac_dh);
901 module_init(rdac_init);
902 module_exit(rdac_exit);
904 MODULE_DESCRIPTION("Multipath LSI/Engenio RDAC driver");
905 MODULE_AUTHOR("Mike Christie, Chandra Seetharaman");
906 MODULE_LICENSE("GPL");