1 /*******************************************************************************
2 * Filename: target_core_iblock.c
4 * This file contains the Storage Engine <-> Linux BlockIO transport
7 * (c) Copyright 2003-2013 Datera, Inc.
9 * Nicholas A. Bellinger <nab@kernel.org>
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2 of the License, or
14 * (at your option) any later version.
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
25 ******************************************************************************/
27 #include <linux/string.h>
28 #include <linux/parser.h>
29 #include <linux/timer.h>
31 #include <linux/blkdev.h>
32 #include <linux/slab.h>
33 #include <linux/spinlock.h>
34 #include <linux/bio.h>
35 #include <linux/genhd.h>
36 #include <linux/file.h>
37 #include <linux/module.h>
38 #include <scsi/scsi_proto.h>
39 #include <asm/unaligned.h>
41 #include <target/target_core_base.h>
42 #include <target/target_core_backend.h>
44 #include "target_core_iblock.h"
46 #define IBLOCK_MAX_BIO_PER_TASK 32 /* max # of bios to submit at a time */
47 #define IBLOCK_BIO_POOL_SIZE 128
49 static inline struct iblock_dev *IBLOCK_DEV(struct se_device *dev)
51 return container_of(dev, struct iblock_dev, dev);
55 static int iblock_attach_hba(struct se_hba *hba, u32 host_id)
57 pr_debug("CORE_HBA[%d] - TCM iBlock HBA Driver %s on"
58 " Generic Target Core Stack %s\n", hba->hba_id,
59 IBLOCK_VERSION, TARGET_CORE_VERSION);
63 static void iblock_detach_hba(struct se_hba *hba)
67 static struct se_device *iblock_alloc_device(struct se_hba *hba, const char *name)
69 struct iblock_dev *ib_dev = NULL;
71 ib_dev = kzalloc(sizeof(struct iblock_dev), GFP_KERNEL);
73 pr_err("Unable to allocate struct iblock_dev\n");
77 pr_debug( "IBLOCK: Allocated ib_dev for %s\n", name);
82 static int iblock_configure_device(struct se_device *dev)
84 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
85 struct request_queue *q;
86 struct block_device *bd = NULL;
87 struct blk_integrity *bi;
89 unsigned int max_write_zeroes_sectors;
92 if (!(ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)) {
93 pr_err("Missing udev_path= parameters for IBLOCK\n");
97 ib_dev->ibd_bio_set = bioset_create(IBLOCK_BIO_POOL_SIZE, 0, BIOSET_NEED_BVECS);
98 if (!ib_dev->ibd_bio_set) {
99 pr_err("IBLOCK: Unable to create bioset\n");
103 pr_debug( "IBLOCK: Claiming struct block_device: %s\n",
104 ib_dev->ibd_udev_path);
106 mode = FMODE_READ|FMODE_EXCL;
107 if (!ib_dev->ibd_readonly)
110 dev->dev_flags |= DF_READ_ONLY;
112 bd = blkdev_get_by_path(ib_dev->ibd_udev_path, mode, ib_dev);
115 goto out_free_bioset;
119 q = bdev_get_queue(bd);
121 dev->dev_attrib.hw_block_size = bdev_logical_block_size(bd);
122 dev->dev_attrib.hw_max_sectors = queue_max_hw_sectors(q);
123 dev->dev_attrib.hw_queue_depth = q->nr_requests;
125 if (target_configure_unmap_from_queue(&dev->dev_attrib, q))
126 pr_debug("IBLOCK: BLOCK Discard support available,"
127 " disabled by default\n");
130 * Enable write same emulation for IBLOCK and use 0xFFFF as
131 * the smaller WRITE_SAME(10) only has a two-byte block count.
133 max_write_zeroes_sectors = bdev_write_zeroes_sectors(bd);
134 if (max_write_zeroes_sectors)
135 dev->dev_attrib.max_write_same_len = max_write_zeroes_sectors;
137 dev->dev_attrib.max_write_same_len = 0xFFFF;
139 if (blk_queue_nonrot(q))
140 dev->dev_attrib.is_nonrot = 1;
142 bi = bdev_get_integrity(bd);
144 struct bio_set *bs = ib_dev->ibd_bio_set;
146 if (!strcmp(bi->profile->name, "T10-DIF-TYPE3-IP") ||
147 !strcmp(bi->profile->name, "T10-DIF-TYPE1-IP")) {
148 pr_err("IBLOCK export of blk_integrity: %s not"
149 " supported\n", bi->profile->name);
154 if (!strcmp(bi->profile->name, "T10-DIF-TYPE3-CRC")) {
155 dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE3_PROT;
156 } else if (!strcmp(bi->profile->name, "T10-DIF-TYPE1-CRC")) {
157 dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE1_PROT;
160 if (dev->dev_attrib.pi_prot_type) {
161 if (bioset_integrity_create(bs, IBLOCK_BIO_POOL_SIZE) < 0) {
162 pr_err("Unable to allocate bioset for PI\n");
166 pr_debug("IBLOCK setup BIP bs->bio_integrity_pool: %p\n",
167 bs->bio_integrity_pool);
169 dev->dev_attrib.hw_pi_prot_type = dev->dev_attrib.pi_prot_type;
175 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
177 bioset_free(ib_dev->ibd_bio_set);
178 ib_dev->ibd_bio_set = NULL;
183 static void iblock_dev_call_rcu(struct rcu_head *p)
185 struct se_device *dev = container_of(p, struct se_device, rcu_head);
186 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
191 static void iblock_free_device(struct se_device *dev)
193 call_rcu(&dev->rcu_head, iblock_dev_call_rcu);
196 static void iblock_destroy_device(struct se_device *dev)
198 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
200 if (ib_dev->ibd_bd != NULL)
201 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
202 if (ib_dev->ibd_bio_set != NULL)
203 bioset_free(ib_dev->ibd_bio_set);
206 static unsigned long long iblock_emulate_read_cap_with_block_size(
207 struct se_device *dev,
208 struct block_device *bd,
209 struct request_queue *q)
211 unsigned long long blocks_long = (div_u64(i_size_read(bd->bd_inode),
212 bdev_logical_block_size(bd)) - 1);
213 u32 block_size = bdev_logical_block_size(bd);
215 if (block_size == dev->dev_attrib.block_size)
218 switch (block_size) {
220 switch (dev->dev_attrib.block_size) {
234 switch (dev->dev_attrib.block_size) {
249 switch (dev->dev_attrib.block_size) {
264 switch (dev->dev_attrib.block_size) {
285 static void iblock_complete_cmd(struct se_cmd *cmd)
287 struct iblock_req *ibr = cmd->priv;
290 if (!refcount_dec_and_test(&ibr->pending))
293 if (atomic_read(&ibr->ib_bio_err_cnt))
294 status = SAM_STAT_CHECK_CONDITION;
296 status = SAM_STAT_GOOD;
298 target_complete_cmd(cmd, status);
302 static void iblock_bio_done(struct bio *bio)
304 struct se_cmd *cmd = bio->bi_private;
305 struct iblock_req *ibr = cmd->priv;
307 if (bio->bi_status) {
308 pr_err("bio error: %p, err: %d\n", bio, bio->bi_status);
310 * Bump the ib_bio_err_cnt and release bio.
312 atomic_inc(&ibr->ib_bio_err_cnt);
313 smp_mb__after_atomic();
318 iblock_complete_cmd(cmd);
322 iblock_get_bio(struct se_cmd *cmd, sector_t lba, u32 sg_num, int op,
325 struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
329 * Only allocate as many vector entries as the bio code allows us to,
330 * we'll loop later on until we have handled the whole request.
332 if (sg_num > BIO_MAX_PAGES)
333 sg_num = BIO_MAX_PAGES;
335 bio = bio_alloc_bioset(GFP_NOIO, sg_num, ib_dev->ibd_bio_set);
337 pr_err("Unable to allocate memory for bio\n");
341 bio_set_dev(bio, ib_dev->ibd_bd);
342 bio->bi_private = cmd;
343 bio->bi_end_io = &iblock_bio_done;
344 bio->bi_iter.bi_sector = lba;
345 bio_set_op_attrs(bio, op, op_flags);
350 static void iblock_submit_bios(struct bio_list *list)
352 struct blk_plug plug;
355 blk_start_plug(&plug);
356 while ((bio = bio_list_pop(list)))
358 blk_finish_plug(&plug);
361 static void iblock_end_io_flush(struct bio *bio)
363 struct se_cmd *cmd = bio->bi_private;
366 pr_err("IBLOCK: cache flush failed: %d\n", bio->bi_status);
370 target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
372 target_complete_cmd(cmd, SAM_STAT_GOOD);
379 * Implement SYCHRONIZE CACHE. Note that we can't handle lba ranges and must
380 * always flush the whole cache.
382 static sense_reason_t
383 iblock_execute_sync_cache(struct se_cmd *cmd)
385 struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
386 int immed = (cmd->t_task_cdb[1] & 0x2);
390 * If the Immediate bit is set, queue up the GOOD response
391 * for this SYNCHRONIZE_CACHE op.
394 target_complete_cmd(cmd, SAM_STAT_GOOD);
396 bio = bio_alloc(GFP_KERNEL, 0);
397 bio->bi_end_io = iblock_end_io_flush;
398 bio_set_dev(bio, ib_dev->ibd_bd);
399 bio->bi_opf = REQ_OP_WRITE | REQ_PREFLUSH;
401 bio->bi_private = cmd;
406 static sense_reason_t
407 iblock_execute_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
409 struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
410 struct se_device *dev = cmd->se_dev;
413 ret = blkdev_issue_discard(bdev,
414 target_to_linux_sector(dev, lba),
415 target_to_linux_sector(dev, nolb),
418 pr_err("blkdev_issue_discard() failed: %d\n", ret);
419 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
425 static sense_reason_t
426 iblock_execute_zero_out(struct block_device *bdev, struct se_cmd *cmd)
428 struct se_device *dev = cmd->se_dev;
429 struct scatterlist *sg = &cmd->t_data_sg[0];
430 unsigned char *buf, zero = 0x00, *p = &zero;
433 buf = kmap(sg_page(sg)) + sg->offset;
435 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
437 * Fall back to block_execute_write_same() slow-path if
438 * incoming WRITE_SAME payload does not contain zeros.
440 rc = memcmp(buf, p, cmd->data_length);
444 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
446 ret = blkdev_issue_zeroout(bdev,
447 target_to_linux_sector(dev, cmd->t_task_lba),
448 target_to_linux_sector(dev,
449 sbc_get_write_same_sectors(cmd)),
452 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
454 target_complete_cmd(cmd, GOOD);
458 static sense_reason_t
459 iblock_execute_write_same(struct se_cmd *cmd)
461 struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
462 struct iblock_req *ibr;
463 struct scatterlist *sg;
465 struct bio_list list;
466 struct se_device *dev = cmd->se_dev;
467 sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba);
468 sector_t sectors = target_to_linux_sector(dev,
469 sbc_get_write_same_sectors(cmd));
472 pr_err("WRITE_SAME: Protection information with IBLOCK"
473 " backends not supported\n");
474 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
476 sg = &cmd->t_data_sg[0];
478 if (cmd->t_data_nents > 1 ||
479 sg->length != cmd->se_dev->dev_attrib.block_size) {
480 pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
481 " block_size: %u\n", cmd->t_data_nents, sg->length,
482 cmd->se_dev->dev_attrib.block_size);
483 return TCM_INVALID_CDB_FIELD;
486 if (bdev_write_zeroes_sectors(bdev)) {
487 if (!iblock_execute_zero_out(bdev, cmd))
491 ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
496 bio = iblock_get_bio(cmd, block_lba, 1, REQ_OP_WRITE, 0);
500 bio_list_init(&list);
501 bio_list_add(&list, bio);
503 refcount_set(&ibr->pending, 1);
506 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
509 bio = iblock_get_bio(cmd, block_lba, 1, REQ_OP_WRITE,
514 refcount_inc(&ibr->pending);
515 bio_list_add(&list, bio);
518 /* Always in 512 byte units for Linux/Block */
519 block_lba += sg->length >> IBLOCK_LBA_SHIFT;
523 iblock_submit_bios(&list);
527 while ((bio = bio_list_pop(&list)))
532 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
536 Opt_udev_path, Opt_readonly, Opt_force, Opt_err
539 static match_table_t tokens = {
540 {Opt_udev_path, "udev_path=%s"},
541 {Opt_readonly, "readonly=%d"},
542 {Opt_force, "force=%d"},
546 static ssize_t iblock_set_configfs_dev_params(struct se_device *dev,
547 const char *page, ssize_t count)
549 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
550 char *orig, *ptr, *arg_p, *opts;
551 substring_t args[MAX_OPT_ARGS];
553 unsigned long tmp_readonly;
555 opts = kstrdup(page, GFP_KERNEL);
561 while ((ptr = strsep(&opts, ",\n")) != NULL) {
565 token = match_token(ptr, tokens, args);
568 if (ib_dev->ibd_bd) {
569 pr_err("Unable to set udev_path= while"
570 " ib_dev->ibd_bd exists\n");
574 if (match_strlcpy(ib_dev->ibd_udev_path, &args[0],
575 SE_UDEV_PATH_LEN) == 0) {
579 pr_debug("IBLOCK: Referencing UDEV path: %s\n",
580 ib_dev->ibd_udev_path);
581 ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH;
584 arg_p = match_strdup(&args[0]);
589 ret = kstrtoul(arg_p, 0, &tmp_readonly);
592 pr_err("kstrtoul() failed for"
596 ib_dev->ibd_readonly = tmp_readonly;
597 pr_debug("IBLOCK: readonly: %d\n", ib_dev->ibd_readonly);
608 return (!ret) ? count : ret;
611 static ssize_t iblock_show_configfs_dev_params(struct se_device *dev, char *b)
613 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
614 struct block_device *bd = ib_dev->ibd_bd;
615 char buf[BDEVNAME_SIZE];
619 bl += sprintf(b + bl, "iBlock device: %s",
621 if (ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)
622 bl += sprintf(b + bl, " UDEV PATH: %s",
623 ib_dev->ibd_udev_path);
624 bl += sprintf(b + bl, " readonly: %d\n", ib_dev->ibd_readonly);
626 bl += sprintf(b + bl, " ");
628 bl += sprintf(b + bl, "Major: %d Minor: %d %s\n",
629 MAJOR(bd->bd_dev), MINOR(bd->bd_dev), (!bd->bd_contains) ?
630 "" : (bd->bd_holder == ib_dev) ?
631 "CLAIMED: IBLOCK" : "CLAIMED: OS");
633 bl += sprintf(b + bl, "Major: 0 Minor: 0\n");
640 iblock_alloc_bip(struct se_cmd *cmd, struct bio *bio)
642 struct se_device *dev = cmd->se_dev;
643 struct blk_integrity *bi;
644 struct bio_integrity_payload *bip;
645 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
646 struct scatterlist *sg;
649 bi = bdev_get_integrity(ib_dev->ibd_bd);
651 pr_err("Unable to locate bio_integrity\n");
655 bip = bio_integrity_alloc(bio, GFP_NOIO, cmd->t_prot_nents);
657 pr_err("Unable to allocate bio_integrity_payload\n");
661 bip->bip_iter.bi_size = (cmd->data_length / dev->dev_attrib.block_size) *
663 bip->bip_iter.bi_sector = bio->bi_iter.bi_sector;
665 pr_debug("IBLOCK BIP Size: %u Sector: %llu\n", bip->bip_iter.bi_size,
666 (unsigned long long)bip->bip_iter.bi_sector);
668 for_each_sg(cmd->t_prot_sg, sg, cmd->t_prot_nents, i) {
670 rc = bio_integrity_add_page(bio, sg_page(sg), sg->length,
672 if (rc != sg->length) {
673 pr_err("bio_integrity_add_page() failed; %d\n", rc);
677 pr_debug("Added bio integrity page: %p length: %d offset; %d\n",
678 sg_page(sg), sg->length, sg->offset);
684 static sense_reason_t
685 iblock_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
686 enum dma_data_direction data_direction)
688 struct se_device *dev = cmd->se_dev;
689 sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba);
690 struct iblock_req *ibr;
691 struct bio *bio, *bio_start;
692 struct bio_list list;
693 struct scatterlist *sg;
694 u32 sg_num = sgl_nents;
696 int i, op, op_flags = 0;
698 if (data_direction == DMA_TO_DEVICE) {
699 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
700 struct request_queue *q = bdev_get_queue(ib_dev->ibd_bd);
702 * Force writethrough using REQ_FUA if a volatile write cache
703 * is not enabled, or if initiator set the Force Unit Access bit.
706 if (test_bit(QUEUE_FLAG_FUA, &q->queue_flags)) {
707 if (cmd->se_cmd_flags & SCF_FUA)
709 else if (!test_bit(QUEUE_FLAG_WC, &q->queue_flags))
716 ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
722 refcount_set(&ibr->pending, 1);
723 iblock_complete_cmd(cmd);
727 bio = iblock_get_bio(cmd, block_lba, sgl_nents, op, op_flags);
732 bio_list_init(&list);
733 bio_list_add(&list, bio);
735 refcount_set(&ibr->pending, 2);
738 for_each_sg(sgl, sg, sgl_nents, i) {
740 * XXX: if the length the device accepts is shorter than the
741 * length of the S/G list entry this will cause and
742 * endless loop. Better hope no driver uses huge pages.
744 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
746 if (bio_cnt >= IBLOCK_MAX_BIO_PER_TASK) {
747 iblock_submit_bios(&list);
751 bio = iblock_get_bio(cmd, block_lba, sg_num, op,
756 refcount_inc(&ibr->pending);
757 bio_list_add(&list, bio);
761 /* Always in 512 byte units for Linux/Block */
762 block_lba += sg->length >> IBLOCK_LBA_SHIFT;
766 if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
767 int rc = iblock_alloc_bip(cmd, bio_start);
772 iblock_submit_bios(&list);
773 iblock_complete_cmd(cmd);
777 while ((bio = bio_list_pop(&list)))
782 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
785 static sector_t iblock_get_blocks(struct se_device *dev)
787 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
788 struct block_device *bd = ib_dev->ibd_bd;
789 struct request_queue *q = bdev_get_queue(bd);
791 return iblock_emulate_read_cap_with_block_size(dev, bd, q);
794 static sector_t iblock_get_alignment_offset_lbas(struct se_device *dev)
796 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
797 struct block_device *bd = ib_dev->ibd_bd;
800 ret = bdev_alignment_offset(bd);
804 /* convert offset-bytes to offset-lbas */
805 return ret / bdev_logical_block_size(bd);
808 static unsigned int iblock_get_lbppbe(struct se_device *dev)
810 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
811 struct block_device *bd = ib_dev->ibd_bd;
812 int logs_per_phys = bdev_physical_block_size(bd) / bdev_logical_block_size(bd);
814 return ilog2(logs_per_phys);
817 static unsigned int iblock_get_io_min(struct se_device *dev)
819 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
820 struct block_device *bd = ib_dev->ibd_bd;
822 return bdev_io_min(bd);
825 static unsigned int iblock_get_io_opt(struct se_device *dev)
827 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
828 struct block_device *bd = ib_dev->ibd_bd;
830 return bdev_io_opt(bd);
833 static struct sbc_ops iblock_sbc_ops = {
834 .execute_rw = iblock_execute_rw,
835 .execute_sync_cache = iblock_execute_sync_cache,
836 .execute_write_same = iblock_execute_write_same,
837 .execute_unmap = iblock_execute_unmap,
840 static sense_reason_t
841 iblock_parse_cdb(struct se_cmd *cmd)
843 return sbc_parse_cdb(cmd, &iblock_sbc_ops);
846 static bool iblock_get_write_cache(struct se_device *dev)
848 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
849 struct block_device *bd = ib_dev->ibd_bd;
850 struct request_queue *q = bdev_get_queue(bd);
852 return test_bit(QUEUE_FLAG_WC, &q->queue_flags);
855 static const struct target_backend_ops iblock_ops = {
857 .inquiry_prod = "IBLOCK",
858 .inquiry_rev = IBLOCK_VERSION,
859 .owner = THIS_MODULE,
860 .attach_hba = iblock_attach_hba,
861 .detach_hba = iblock_detach_hba,
862 .alloc_device = iblock_alloc_device,
863 .configure_device = iblock_configure_device,
864 .destroy_device = iblock_destroy_device,
865 .free_device = iblock_free_device,
866 .parse_cdb = iblock_parse_cdb,
867 .set_configfs_dev_params = iblock_set_configfs_dev_params,
868 .show_configfs_dev_params = iblock_show_configfs_dev_params,
869 .get_device_type = sbc_get_device_type,
870 .get_blocks = iblock_get_blocks,
871 .get_alignment_offset_lbas = iblock_get_alignment_offset_lbas,
872 .get_lbppbe = iblock_get_lbppbe,
873 .get_io_min = iblock_get_io_min,
874 .get_io_opt = iblock_get_io_opt,
875 .get_write_cache = iblock_get_write_cache,
876 .tb_dev_attrib_attrs = sbc_attrib_attrs,
879 static int __init iblock_module_init(void)
881 return transport_backend_register(&iblock_ops);
884 static void __exit iblock_module_exit(void)
886 target_backend_unregister(&iblock_ops);
889 MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin");
890 MODULE_AUTHOR("nab@Linux-iSCSI.org");
891 MODULE_LICENSE("GPL");
893 module_init(iblock_module_init);
894 module_exit(iblock_module_exit);