From: Mike Christie This patch from Chandra Seetharaman and updated to upstream by me, supports LSI/Engenio devices in RDAC mode. Like dm-emc it requires userspace support. In your multipath.conf file you must have: path_checker rdac hardware_handler "1 rdac" And you also then must have a updated multipath tools release which has rdac support. Signed-off-by: Chandra Seetharaman Signed-off-by: Mike Christie Signed-off-by: Alasdair G Kergon --- drivers/md/Kconfig | 6 drivers/md/Makefile | 2 drivers/md/dm-mpath-rdac.c | 715 +++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 723 insertions(+) Index: linux/drivers/md/Kconfig =================================================================== --- linux.orig/drivers/md/Kconfig 2007-07-11 21:37:50.000000000 +0100 +++ linux/drivers/md/Kconfig 2007-07-11 21:37:54.000000000 +0100 @@ -262,6 +262,12 @@ config DM_MULTIPATH_EMC ---help--- Multipath support for EMC CX/AX series hardware. +config DM_MULTIPATH_RDAC + tristate "LSI/Engenio RDAC multipath support (EXPERIMENTAL)" + depends on DM_MULTIPATH && BLK_DEV_DM && EXPERIMENTAL + ---help--- + Multipath support for LSI/Engenio RDAC. + config DM_DELAY tristate "I/O delaying target (EXPERIMENTAL)" depends on BLK_DEV_DM && EXPERIMENTAL Index: linux/drivers/md/Makefile =================================================================== --- linux.orig/drivers/md/Makefile 2007-07-11 21:37:50.000000000 +0100 +++ linux/drivers/md/Makefile 2007-07-11 21:37:54.000000000 +0100 @@ -7,6 +7,7 @@ dm-mod-objs := dm.o dm-table.o dm-target dm-multipath-objs := dm-hw-handler.o dm-path-selector.o dm-mpath.o dm-snapshot-objs := dm-snap.o dm-exception-store.o dm-mirror-objs := dm-log.o dm-raid1.o +dm-rdac-objs := dm-mpath-rdac.o md-mod-objs := md.o bitmap.o raid456-objs := raid5.o raid6algos.o raid6recov.o raid6tables.o \ raid6int1.o raid6int2.o raid6int4.o \ @@ -34,6 +35,7 @@ obj-$(CONFIG_DM_CRYPT) += dm-crypt.o obj-$(CONFIG_DM_DELAY) += dm-delay.o obj-$(CONFIG_DM_MULTIPATH) += dm-multipath.o dm-round-robin.o obj-$(CONFIG_DM_MULTIPATH_EMC) += dm-emc.o +obj-$(CONFIG_DM_MULTIPATH_RDAC) += dm-rdac.o obj-$(CONFIG_DM_SNAPSHOT) += dm-snapshot.o obj-$(CONFIG_DM_MIRROR) += dm-mirror.o obj-$(CONFIG_DM_ZERO) += dm-zero.o Index: linux/drivers/md/dm-mpath-rdac.c =================================================================== --- /dev/null 1970-01-01 00:00:00.000000000 +0000 +++ linux/drivers/md/dm-mpath-rdac.c 2007-07-11 21:37:54.000000000 +0100 @@ -0,0 +1,715 @@ +/* + * Engenio/LSI RDAC DM HW handler + * + * Copyright (C) 2005 Mike Christie. All rights reserved. + * Copyright (C) Chandra Seetharaman, IBM Corp. 2007 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + * + */ +#include +#include +#include + +#define DM_MSG_PREFIX "multipath rdac" + +#include "dm.h" +#include "dm-hw-handler.h" + +#define RDAC_DM_HWH_NAME "rdac" +#define RDAC_DM_HWH_VER "0.4" + +/* + * LSI mode page stuff + * + * These struct definitions and the forming of the + * mode page were taken from the LSI RDAC 2.4 GPL'd + * driver, and then converted to Linux conventions. + */ +#define RDAC_QUIESCENCE_TIME 20; +/* + * Page Codes + */ +#define RDAC_PAGE_CODE_REDUNDANT_CONTROLLER 0x2c + +/* + * Controller modes definitions + */ +#define RDAC_MODE_TRANSFER_ALL_LUNS 0x01 +#define RDAC_MODE_TRANSFER_SPECIFIED_LUNS 0x02 + +/* + * RDAC Options field + */ +#define RDAC_FORCED_QUIESENCE 0x02 + +/* + * default value TODO - make configurable + */ +#define RDAC_FAILOVER_TIMEOUT (60 * HZ) + +struct rdac_mode_6_hdr { + u8 data_len; + u8 medium_type; + u8 device_params; + u8 block_desc_len; +}; + +struct rdac_mode_10_hdr { + u16 data_len; + u8 medium_type; + u8 device_params; + u16 reserved; + u16 block_desc_len; +}; + +struct rdac_mode_common { + u8 controller_serial[16]; + u8 alt_controller_serial[16]; + u8 rdac_mode[2]; + u8 alt_rdac_mode[2]; + u8 quiescence_timeout; + u8 rdac_options; +}; + +struct rdac_pg_legacy { + struct rdac_mode_6_hdr hdr; + u8 page_code; + u8 page_len; + struct rdac_mode_common common; +#define MODE6_MAX_LUN 32 + u8 lun_table[MODE6_MAX_LUN]; + u8 reserved2[32]; + u8 reserved3; + u8 reserved4; +}; + +struct rdac_pg_expanded { + struct rdac_mode_10_hdr hdr; + u8 page_code; + u8 subpage_code; + u8 page_len[2]; + struct rdac_mode_common common; + u8 lun_table[256]; + u8 reserved3; + u8 reserved4; +}; + +struct c9_inquiry { + u8 peripheral_info; + u8 page_code; /* 0xC9 */ + u8 reserved1; + u8 page_len; + u8 page_id[4]; /* "vace" */ + u8 avte_cvp; + u8 path_prio; + u8 reserved2[38]; +}; + +#define SUBSYS_ID_LEN 16 +#define SLOT_ID_LEN 2 + +struct c4_inquiry { + u8 peripheral_info; + u8 page_code; /* 0xC4 */ + u8 reserved1; + u8 page_len; + u8 page_id[4]; /* "subs" */ + u8 subsys_id[SUBSYS_ID_LEN]; + u8 revision[4]; + u8 slot_id[SLOT_ID_LEN]; + u8 reserved[2]; +}; + +struct rdac_controller { + u8 subsys_id[SUBSYS_ID_LEN]; + u8 slot_id[SLOT_ID_LEN]; + int use_10_ms; + struct kref kref; + struct list_head node; /* list of all controllers */ + spinlock_t lock; + int submitted; + struct list_head cmd_list; /* list of commands to be submitted */ + union { + struct rdac_pg_legacy legacy; + struct rdac_pg_expanded exp; + } mode_select; +}; +struct c8_inquiry { + u8 peripheral_info; + u8 page_code; /* 0xC8 */ + u8 reserved1; + u8 page_len; + u8 page_id[4]; /* "edid" */ + u8 reserved2[3]; + u8 vol_uniq_id_len; + u8 vol_uniq_id[16]; + u8 vol_user_label_len; + u8 vol_user_label[60]; + u8 array_uniq_id_len; + u8 array_unique_id[16]; + u8 array_user_label_len; + u8 array_user_label[60]; + u8 lun[8]; +}; + +struct c2_inquiry { + u8 peripheral_info; + u8 page_code; /* 0xC2 */ + u8 reserved1; + u8 page_len; + u8 page_id[4]; /* "swr4" */ + u8 sw_version[3]; + u8 sw_date[3]; + u8 features_enabled; + u8 max_lun_supported; + u8 partitions[239]; /* Total allocation length should be 0xFF */ +}; + +struct rdac_handler { + struct list_head entry; /* list waiting to submit MODE SELECT */ + unsigned timeout; + struct rdac_controller *ctlr; +#define UNINITIALIZED_LUN (1 << 8) + unsigned lun; + unsigned char sense[SCSI_SENSE_BUFFERSIZE]; + struct dm_path *path; + struct work_struct work; +#define SEND_C2_INQUIRY 1 +#define SEND_C4_INQUIRY 2 +#define SEND_C8_INQUIRY 3 +#define SEND_C9_INQUIRY 4 +#define SEND_MODE_SELECT 5 + int cmd_to_send; + union { + struct c2_inquiry c2; + struct c4_inquiry c4; + struct c8_inquiry c8; + struct c9_inquiry c9; + } inq; +}; + +static LIST_HEAD(ctlr_list); +static spinlock_t list_lock = SPIN_LOCK_UNLOCKED; +static struct workqueue_struct *rdac_wkqd; + +static void submit_inquiry(struct rdac_handler *, int, unsigned int, + rq_end_io_fn *); +static void c9_inquiry_endio(struct request *, int); +#define submit_c9_inquiry(h) \ + submit_inquiry(h, 0xC9, sizeof(struct c9_inquiry), c9_inquiry_endio) +#define submit_c4_inquiry(h) \ + submit_inquiry(h, 0xC4, sizeof(struct c4_inquiry), c4_inquiry_endio) +#define submit_c8_inquiry(h) \ + submit_inquiry(h, 0xC8, sizeof(struct c8_inquiry), c8_inquiry_endio) +#define submit_c2_inquiry(h) \ + submit_inquiry(h, 0xC2, sizeof(struct c2_inquiry), c2_inquiry_endio) + +static inline int had_failures(struct request *req, int error) +{ + return (error || host_byte(req->errors) != DID_OK || + msg_byte(req->errors) != COMMAND_COMPLETE); +} + +static void rdac_resubmit_all(struct rdac_handler *h) +{ + struct rdac_controller *ctlr = h->ctlr; + struct rdac_handler *tmp, *h1; + + spin_lock(&ctlr->lock); + list_for_each_entry_safe(h1, tmp, &ctlr->cmd_list, entry) { + h1->cmd_to_send = SEND_C9_INQUIRY; + queue_work(rdac_wkqd, &h1->work); + list_del(&h1->entry); + } + ctlr->submitted = 0; + spin_unlock(&ctlr->lock); +} + +static void mode_select_endio(struct request *req, int error) +{ + struct rdac_handler *h = req->end_io_data; + struct scsi_sense_hdr sense_hdr; + int sense = 0, fail = 0; + + if (had_failures(req, error)) { + fail = 1; + goto failed; + } + + if (status_byte(req->errors) == CHECK_CONDITION) { + scsi_normalize_sense(req->sense, SCSI_SENSE_BUFFERSIZE, + &sense_hdr); + sense = (sense_hdr.sense_key << 16) | (sense_hdr.asc << 8) | + sense_hdr.ascq; + /* If it is retryable failure, submit the c9 inquiry again */ + if (sense == 0x59136 || sense == 0x68b02 || sense == 0xb8b02 || + sense == 0x62900) { + /* 0x59136 - Command lock contention + * 0x[6b]8b02 - Quiesense in progress or achieved + * 0x62900 - Power On, Reset, or Bus Device Reset + */ + h->cmd_to_send = SEND_C9_INQUIRY; + queue_work(rdac_wkqd, &h->work); + goto done; + } + if (sense) + DMINFO("MODE_SELECT failed on %s with sense 0x%x", + h->path->dev->name, sense); + } +failed: + if (fail || sense) + dm_pg_init_complete(h->path, MP_FAIL_PATH); + else + dm_pg_init_complete(h->path, 0); + +done: + rdac_resubmit_all(h); + __blk_put_request(req->q, req); +} + +static struct request *get_rdac_req(struct rdac_handler *h, + void *buffer, unsigned buflen, int rw) +{ + struct request *rq; + struct request_queue *q = bdev_get_queue(h->path->dev->bdev); + + rq = blk_get_request(q, rw, GFP_ATOMIC); + + if (!rq) { + DMINFO("get_rdac_req: blk_get_request failed"); + return NULL; + } + + if (buflen && blk_rq_map_kern(q, rq, buffer, buflen, GFP_ATOMIC)) { + blk_put_request(rq); + DMINFO("get_rdac_req: blk_rq_map_kern failed"); + return NULL; + } + + memset(&rq->cmd, 0, BLK_MAX_CDB); + rq->sense = h->sense; + memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE); + rq->sense_len = 0; + + rq->end_io_data = h; + rq->timeout = h->timeout; + rq->cmd_type = REQ_TYPE_BLOCK_PC; + rq->cmd_flags = REQ_FAILFAST | REQ_NOMERGE; + return rq; +} + +static struct request *rdac_failover_get(struct rdac_handler *h) +{ + struct request *rq; + struct rdac_mode_common *common; + unsigned data_size; + + if (h->ctlr->use_10_ms) { + struct rdac_pg_expanded *rdac_pg; + + data_size = sizeof(struct rdac_pg_expanded); + rdac_pg = (struct rdac_pg_expanded *)&h->ctlr->mode_select; + memset(rdac_pg, 0, data_size); + common = &rdac_pg->common; + rdac_pg->page_code = RDAC_PAGE_CODE_REDUNDANT_CONTROLLER + 0x40; + rdac_pg->subpage_code = 0x1; + rdac_pg->page_len[0] = 0x01; + rdac_pg->page_len[1] = 0x28; + rdac_pg->lun_table[h->lun] = 0x81; + } else { + struct rdac_pg_legacy *rdac_pg; + + data_size = sizeof(struct rdac_pg_legacy); + rdac_pg = (struct rdac_pg_legacy *)&h->ctlr->mode_select; + memset(rdac_pg, 0, data_size); + common = &rdac_pg->common; + rdac_pg->page_code = RDAC_PAGE_CODE_REDUNDANT_CONTROLLER; + rdac_pg->page_len = 0x68; + rdac_pg->lun_table[h->lun] = 0x81; + } + common->rdac_mode[1] = RDAC_MODE_TRANSFER_SPECIFIED_LUNS; + common->quiescence_timeout = RDAC_QUIESCENCE_TIME; + common->rdac_options = RDAC_FORCED_QUIESENCE; + + /* get request for block layer packet command */ + rq = get_rdac_req(h, &h->ctlr->mode_select, data_size, WRITE); + if (!rq) { + DMERR("rdac_failover_get: no rq"); + return NULL; + } + + /* Prepare the command. */ + if (h->ctlr->use_10_ms) { + rq->cmd[0] = MODE_SELECT_10; + rq->cmd[7] = data_size >> 8; + rq->cmd[8] = data_size & 0xff; + } else { + rq->cmd[0] = MODE_SELECT; + rq->cmd[4] = data_size; + } + rq->cmd_len = COMMAND_SIZE(rq->cmd[0]); + + return rq; +} + +/* Acquires h->ctlr->lock */ +static void submit_mode_select(struct rdac_handler *h) +{ + struct request *rq; + struct request_queue *q = bdev_get_queue(h->path->dev->bdev); + + spin_lock(&h->ctlr->lock); + if (h->ctlr->submitted) { + list_add(&h->entry, &h->ctlr->cmd_list); + goto drop_lock; + } + + if (!q) { + DMINFO("submit_mode_select: no queue"); + goto fail_path; + } + + rq = rdac_failover_get(h); + if (!rq) { + DMERR("submit_mode_select: no rq"); + goto fail_path; + } + + DMINFO("queueing MODE_SELECT command on %s", h->path->dev->name); + + blk_execute_rq_nowait(q, NULL, rq, 1, mode_select_endio); + h->ctlr->submitted = 1; + goto drop_lock; +fail_path: + dm_pg_init_complete(h->path, MP_FAIL_PATH); +drop_lock: + spin_unlock(&h->ctlr->lock); +} + +static void release_ctlr(struct kref *kref) +{ + struct rdac_controller *ctlr; + ctlr = container_of(kref, struct rdac_controller, kref); + + spin_lock(&list_lock); + list_del(&ctlr->node); + spin_unlock(&list_lock); + kfree(ctlr); +} + +static struct rdac_controller *get_controller(u8 *subsys_id, u8 *slot_id) +{ + struct rdac_controller *ctlr, *tmp; + + spin_lock(&list_lock); + + list_for_each_entry(tmp, &ctlr_list, node) { + if ((memcmp(tmp->subsys_id, subsys_id, SUBSYS_ID_LEN) == 0) && + (memcmp(tmp->slot_id, slot_id, SLOT_ID_LEN) == 0)) { + kref_get(&tmp->kref); + spin_unlock(&list_lock); + return tmp; + } + } + ctlr = kmalloc(sizeof(*ctlr), GFP_ATOMIC); + if (!ctlr) + goto done; + + /* initialize fields of controller */ + memcpy(ctlr->subsys_id, subsys_id, SUBSYS_ID_LEN); + memcpy(ctlr->slot_id, slot_id, SLOT_ID_LEN); + kref_init(&ctlr->kref); + spin_lock_init(&ctlr->lock); + ctlr->submitted = 0; + ctlr->use_10_ms = -1; + INIT_LIST_HEAD(&ctlr->cmd_list); + list_add(&ctlr->node, &ctlr_list); +done: + spin_unlock(&list_lock); + return ctlr; +} + +static void c4_inquiry_endio(struct request *req, int error) +{ + struct rdac_handler *h = req->end_io_data; + struct c4_inquiry *sp; + + if (had_failures(req, error)) { + dm_pg_init_complete(h->path, MP_FAIL_PATH); + goto done; + } + + sp = (struct c4_inquiry *)&h->inq; + + h->ctlr = get_controller(sp->subsys_id, sp->slot_id); + + if (h->ctlr) { + h->cmd_to_send = SEND_C9_INQUIRY; + queue_work(rdac_wkqd, &h->work); + } else + dm_pg_init_complete(h->path, MP_FAIL_PATH); +done: + __blk_put_request(req->q, req); +} + +static void c2_inquiry_endio(struct request *req, int error) +{ + struct rdac_handler *h = req->end_io_data; + struct c2_inquiry *sp; + + if (had_failures(req, error)) { + dm_pg_init_complete(h->path, MP_FAIL_PATH); + goto done; + } + + sp = (struct c2_inquiry *)&h->inq; + + /* If more than MODE6_MAX_LUN luns are supported, use mode select 10 */ + if (sp->max_lun_supported >= MODE6_MAX_LUN) + h->ctlr->use_10_ms = 1; + else + h->ctlr->use_10_ms = 0; + + h->cmd_to_send = SEND_MODE_SELECT; + queue_work(rdac_wkqd, &h->work); +done: + __blk_put_request(req->q, req); +} + +static void c9_inquiry_endio(struct request *req, int error) +{ + struct rdac_handler *h = req->end_io_data; + struct c9_inquiry *sp; + + if (had_failures(req, error)) { + dm_pg_init_complete(h->path, MP_FAIL_PATH); + goto done; + } + + /* We need to look at the sense keys here to take clear action. + * For now simple logic: If the host is in AVT mode or if controller + * owns the lun, return dm_pg_init_complete(), otherwise submit + * MODE SELECT. + */ + sp = (struct c9_inquiry *)&h->inq; + + /* If in AVT mode, return success */ + if ((sp->avte_cvp >> 7) == 0x1) { + dm_pg_init_complete(h->path, 0); + goto done; + } + + /* If the controller on this path owns the LUN, return success */ + if (sp->avte_cvp & 0x1) { + dm_pg_init_complete(h->path, 0); + goto done; + } + + if (h->ctlr) { + if (h->ctlr->use_10_ms == -1) + h->cmd_to_send = SEND_C2_INQUIRY; + else + h->cmd_to_send = SEND_MODE_SELECT; + } else + h->cmd_to_send = SEND_C4_INQUIRY; + queue_work(rdac_wkqd, &h->work); +done: + __blk_put_request(req->q, req); +} + +static void c8_inquiry_endio(struct request *req, int error) +{ + struct rdac_handler *h = req->end_io_data; + struct c8_inquiry *sp; + + if (had_failures(req, error)) { + dm_pg_init_complete(h->path, MP_FAIL_PATH); + goto done; + } + + /* We need to look at the sense keys here to take clear action. + * For now simple logic: Get the lun from the inquiry page. + */ + sp = (struct c8_inquiry *)&h->inq; + h->lun = sp->lun[7]; /* currently it uses only one byte */ + h->cmd_to_send = SEND_C9_INQUIRY; + queue_work(rdac_wkqd, &h->work); +done: + __blk_put_request(req->q, req); +} + +static void submit_inquiry(struct rdac_handler *h, int page_code, + unsigned int len, rq_end_io_fn endio) +{ + struct request *rq; + struct request_queue *q = bdev_get_queue(h->path->dev->bdev); + + if (!q) + goto fail_path; + + rq = get_rdac_req(h, &h->inq, len, READ); + if (!rq) + goto fail_path; + + /* Prepare the command. */ + rq->cmd[0] = INQUIRY; + rq->cmd[1] = 1; + rq->cmd[2] = page_code; + rq->cmd[4] = len; + rq->cmd_len = COMMAND_SIZE(INQUIRY); + blk_execute_rq_nowait(q, NULL, rq, 1, endio); + return; + +fail_path: + dm_pg_init_complete(h->path, MP_FAIL_PATH); +} + +static void service_wkq(struct work_struct *work) +{ + struct rdac_handler *h = container_of(work, struct rdac_handler, work); + + switch (h->cmd_to_send) { + case SEND_C2_INQUIRY: + submit_c2_inquiry(h); + break; + case SEND_C4_INQUIRY: + submit_c4_inquiry(h); + break; + case SEND_C8_INQUIRY: + submit_c8_inquiry(h); + break; + case SEND_C9_INQUIRY: + submit_c9_inquiry(h); + break; + case SEND_MODE_SELECT: + submit_mode_select(h); + break; + default: + BUG(); + } +} +/* + * only support subpage2c until we confirm that this is just a matter of + * of updating firmware or not, and RDAC (basic AVT works already) for now + * but we can add these in in when we get time and testers + */ +static int rdac_create(struct hw_handler *hwh, unsigned argc, char **argv) +{ + struct rdac_handler *h; + unsigned timeout; + + if (argc == 0) { + /* No arguments: use defaults */ + timeout = RDAC_FAILOVER_TIMEOUT; + } else if (argc != 1) { + DMWARN("incorrect number of arguments"); + return -EINVAL; + } else { + if (sscanf(argv[1], "%u", &timeout) != 1) { + DMWARN("invalid timeout value"); + return -EINVAL; + } + } + + h = kzalloc(sizeof(*h), GFP_KERNEL); + if (!h) + return -ENOMEM; + + hwh->context = h; + h->timeout = timeout; + h->lun = UNINITIALIZED_LUN; + INIT_WORK(&h->work, service_wkq); + DMWARN("using RDAC command with timeout %u", h->timeout); + + return 0; +} + +static void rdac_destroy(struct hw_handler *hwh) +{ + struct rdac_handler *h = (struct rdac_handler *) hwh->context; + + if (h->ctlr) + kref_put(&h->ctlr->kref, release_ctlr); + kfree(h); + hwh->context = NULL; +} + +static unsigned rdac_error(struct hw_handler *hwh, struct bio *bio) +{ + /* Try default handler */ + return dm_scsi_err_handler(hwh, bio); +} + +static void rdac_pg_init(struct hw_handler *hwh, unsigned bypassed, + struct dm_path *path) +{ + struct rdac_handler *h = hwh->context; + + h->path = path; + switch (h->lun) { + case UNINITIALIZED_LUN: + submit_c8_inquiry(h); + break; + default: + submit_c9_inquiry(h); + } +} + +static struct hw_handler_type rdac_handler = { + .name = RDAC_DM_HWH_NAME, + .module = THIS_MODULE, + .create = rdac_create, + .destroy = rdac_destroy, + .pg_init = rdac_pg_init, + .error = rdac_error, +}; + +static int __init rdac_init(void) +{ + int r = dm_register_hw_handler(&rdac_handler); + + if (r < 0) { + DMERR("%s: register failed %d", RDAC_DM_HWH_NAME, r); + return r; + } + + rdac_wkqd = create_singlethread_workqueue("rdac_wkqd"); + if (!rdac_wkqd) { + DMERR("Failed to create workqueue rdac_wkqd."); + dm_unregister_hw_handler(&rdac_handler); + return -ENOMEM; + } + + DMINFO("%s: version %s loaded", RDAC_DM_HWH_NAME, RDAC_DM_HWH_VER); + return 0; +} + +static void __exit rdac_exit(void) +{ + int r = dm_unregister_hw_handler(&rdac_handler); + + destroy_workqueue(rdac_wkqd); + if (r < 0) + DMERR("%s: unregister failed %d", RDAC_DM_HWH_NAME, r); +} + +module_init(rdac_init); +module_exit(rdac_exit); + +MODULE_DESCRIPTION("DM Multipath LSI/Engenio RDAC support"); +MODULE_AUTHOR("Mike Christie, Chandra Seetharaman"); +MODULE_LICENSE("GPL"); +MODULE_VERSION(RDAC_DM_HWH_VER);