target: remove the t_tasks_fua se_cmd field
[linux-2.6.git] / drivers / target / target_core_iblock.c
1 /*******************************************************************************
2  * Filename:  target_core_iblock.c
3  *
4  * This file contains the Storage Engine  <-> Linux BlockIO transport
5  * specific functions.
6  *
7  * Copyright (c) 2003, 2004, 2005 PyX Technologies, Inc.
8  * Copyright (c) 2005, 2006, 2007 SBE, Inc.
9  * Copyright (c) 2007-2010 Rising Tide Systems
10  * Copyright (c) 2008-2010 Linux-iSCSI.org
11  *
12  * Nicholas A. Bellinger <nab@kernel.org>
13  *
14  * This program is free software; you can redistribute it and/or modify
15  * it under the terms of the GNU General Public License as published by
16  * the Free Software Foundation; either version 2 of the License, or
17  * (at your option) any later version.
18  *
19  * This program is distributed in the hope that it will be useful,
20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
22  * GNU General Public License for more details.
23  *
24  * You should have received a copy of the GNU General Public License
25  * along with this program; if not, write to the Free Software
26  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
27  *
28  ******************************************************************************/
29
30 #include <linux/string.h>
31 #include <linux/parser.h>
32 #include <linux/timer.h>
33 #include <linux/fs.h>
34 #include <linux/blkdev.h>
35 #include <linux/slab.h>
36 #include <linux/spinlock.h>
37 #include <linux/bio.h>
38 #include <linux/genhd.h>
39 #include <linux/file.h>
40 #include <linux/module.h>
41 #include <scsi/scsi.h>
42 #include <scsi/scsi_host.h>
43
44 #include <target/target_core_base.h>
45 #include <target/target_core_device.h>
46 #include <target/target_core_transport.h>
47
48 #include "target_core_iblock.h"
49
50 static struct se_subsystem_api iblock_template;
51
52 static void iblock_bio_done(struct bio *, int);
53
54 /*      iblock_attach_hba(): (Part of se_subsystem_api_t template)
55  *
56  *
57  */
58 static int iblock_attach_hba(struct se_hba *hba, u32 host_id)
59 {
60         struct iblock_hba *ib_host;
61
62         ib_host = kzalloc(sizeof(struct iblock_hba), GFP_KERNEL);
63         if (!ib_host) {
64                 pr_err("Unable to allocate memory for"
65                                 " struct iblock_hba\n");
66                 return -ENOMEM;
67         }
68
69         ib_host->iblock_host_id = host_id;
70
71         hba->hba_ptr = ib_host;
72
73         pr_debug("CORE_HBA[%d] - TCM iBlock HBA Driver %s on"
74                 " Generic Target Core Stack %s\n", hba->hba_id,
75                 IBLOCK_VERSION, TARGET_CORE_MOD_VERSION);
76
77         pr_debug("CORE_HBA[%d] - Attached iBlock HBA: %u to Generic\n",
78                 hba->hba_id, ib_host->iblock_host_id);
79
80         return 0;
81 }
82
83 static void iblock_detach_hba(struct se_hba *hba)
84 {
85         struct iblock_hba *ib_host = hba->hba_ptr;
86
87         pr_debug("CORE_HBA[%d] - Detached iBlock HBA: %u from Generic"
88                 " Target Core\n", hba->hba_id, ib_host->iblock_host_id);
89
90         kfree(ib_host);
91         hba->hba_ptr = NULL;
92 }
93
94 static void *iblock_allocate_virtdevice(struct se_hba *hba, const char *name)
95 {
96         struct iblock_dev *ib_dev = NULL;
97         struct iblock_hba *ib_host = hba->hba_ptr;
98
99         ib_dev = kzalloc(sizeof(struct iblock_dev), GFP_KERNEL);
100         if (!ib_dev) {
101                 pr_err("Unable to allocate struct iblock_dev\n");
102                 return NULL;
103         }
104         ib_dev->ibd_host = ib_host;
105
106         pr_debug( "IBLOCK: Allocated ib_dev for %s\n", name);
107
108         return ib_dev;
109 }
110
111 static struct se_device *iblock_create_virtdevice(
112         struct se_hba *hba,
113         struct se_subsystem_dev *se_dev,
114         void *p)
115 {
116         struct iblock_dev *ib_dev = p;
117         struct se_device *dev;
118         struct se_dev_limits dev_limits;
119         struct block_device *bd = NULL;
120         struct request_queue *q;
121         struct queue_limits *limits;
122         u32 dev_flags = 0;
123         int ret = -EINVAL;
124
125         if (!ib_dev) {
126                 pr_err("Unable to locate struct iblock_dev parameter\n");
127                 return ERR_PTR(ret);
128         }
129         memset(&dev_limits, 0, sizeof(struct se_dev_limits));
130         /*
131          * These settings need to be made tunable..
132          */
133         ib_dev->ibd_bio_set = bioset_create(32, 64);
134         if (!ib_dev->ibd_bio_set) {
135                 pr_err("IBLOCK: Unable to create bioset()\n");
136                 return ERR_PTR(-ENOMEM);
137         }
138         pr_debug("IBLOCK: Created bio_set()\n");
139         /*
140          * iblock_check_configfs_dev_params() ensures that ib_dev->ibd_udev_path
141          * must already have been set in order for echo 1 > $HBA/$DEV/enable to run.
142          */
143         pr_debug( "IBLOCK: Claiming struct block_device: %s\n",
144                         ib_dev->ibd_udev_path);
145
146         bd = blkdev_get_by_path(ib_dev->ibd_udev_path,
147                                 FMODE_WRITE|FMODE_READ|FMODE_EXCL, ib_dev);
148         if (IS_ERR(bd)) {
149                 ret = PTR_ERR(bd);
150                 goto failed;
151         }
152         /*
153          * Setup the local scope queue_limits from struct request_queue->limits
154          * to pass into transport_add_device_to_core_hba() as struct se_dev_limits.
155          */
156         q = bdev_get_queue(bd);
157         limits = &dev_limits.limits;
158         limits->logical_block_size = bdev_logical_block_size(bd);
159         limits->max_hw_sectors = queue_max_hw_sectors(q);
160         limits->max_sectors = queue_max_sectors(q);
161         dev_limits.hw_queue_depth = q->nr_requests;
162         dev_limits.queue_depth = q->nr_requests;
163
164         ib_dev->ibd_bd = bd;
165
166         dev = transport_add_device_to_core_hba(hba,
167                         &iblock_template, se_dev, dev_flags, ib_dev,
168                         &dev_limits, "IBLOCK", IBLOCK_VERSION);
169         if (!dev)
170                 goto failed;
171
172         /*
173          * Check if the underlying struct block_device request_queue supports
174          * the QUEUE_FLAG_DISCARD bit for UNMAP/WRITE_SAME in SCSI + TRIM
175          * in ATA and we need to set TPE=1
176          */
177         if (blk_queue_discard(q)) {
178                 dev->se_sub_dev->se_dev_attrib.max_unmap_lba_count =
179                                 q->limits.max_discard_sectors;
180                 /*
181                  * Currently hardcoded to 1 in Linux/SCSI code..
182                  */
183                 dev->se_sub_dev->se_dev_attrib.max_unmap_block_desc_count = 1;
184                 dev->se_sub_dev->se_dev_attrib.unmap_granularity =
185                                 q->limits.discard_granularity;
186                 dev->se_sub_dev->se_dev_attrib.unmap_granularity_alignment =
187                                 q->limits.discard_alignment;
188
189                 pr_debug("IBLOCK: BLOCK Discard support available,"
190                                 " disabled by default\n");
191         }
192
193         if (blk_queue_nonrot(q))
194                 dev->se_sub_dev->se_dev_attrib.is_nonrot = 1;
195
196         return dev;
197
198 failed:
199         if (ib_dev->ibd_bio_set) {
200                 bioset_free(ib_dev->ibd_bio_set);
201                 ib_dev->ibd_bio_set = NULL;
202         }
203         ib_dev->ibd_bd = NULL;
204         return ERR_PTR(ret);
205 }
206
207 static void iblock_free_device(void *p)
208 {
209         struct iblock_dev *ib_dev = p;
210
211         if (ib_dev->ibd_bd != NULL)
212                 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
213         if (ib_dev->ibd_bio_set != NULL)
214                 bioset_free(ib_dev->ibd_bio_set);
215         kfree(ib_dev);
216 }
217
218 static inline struct iblock_req *IBLOCK_REQ(struct se_task *task)
219 {
220         return container_of(task, struct iblock_req, ib_task);
221 }
222
223 static struct se_task *
224 iblock_alloc_task(unsigned char *cdb)
225 {
226         struct iblock_req *ib_req;
227
228         ib_req = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
229         if (!ib_req) {
230                 pr_err("Unable to allocate memory for struct iblock_req\n");
231                 return NULL;
232         }
233
234         atomic_set(&ib_req->ib_bio_cnt, 0);
235         return &ib_req->ib_task;
236 }
237
238 static unsigned long long iblock_emulate_read_cap_with_block_size(
239         struct se_device *dev,
240         struct block_device *bd,
241         struct request_queue *q)
242 {
243         unsigned long long blocks_long = (div_u64(i_size_read(bd->bd_inode),
244                                         bdev_logical_block_size(bd)) - 1);
245         u32 block_size = bdev_logical_block_size(bd);
246
247         if (block_size == dev->se_sub_dev->se_dev_attrib.block_size)
248                 return blocks_long;
249
250         switch (block_size) {
251         case 4096:
252                 switch (dev->se_sub_dev->se_dev_attrib.block_size) {
253                 case 2048:
254                         blocks_long <<= 1;
255                         break;
256                 case 1024:
257                         blocks_long <<= 2;
258                         break;
259                 case 512:
260                         blocks_long <<= 3;
261                 default:
262                         break;
263                 }
264                 break;
265         case 2048:
266                 switch (dev->se_sub_dev->se_dev_attrib.block_size) {
267                 case 4096:
268                         blocks_long >>= 1;
269                         break;
270                 case 1024:
271                         blocks_long <<= 1;
272                         break;
273                 case 512:
274                         blocks_long <<= 2;
275                         break;
276                 default:
277                         break;
278                 }
279                 break;
280         case 1024:
281                 switch (dev->se_sub_dev->se_dev_attrib.block_size) {
282                 case 4096:
283                         blocks_long >>= 2;
284                         break;
285                 case 2048:
286                         blocks_long >>= 1;
287                         break;
288                 case 512:
289                         blocks_long <<= 1;
290                         break;
291                 default:
292                         break;
293                 }
294                 break;
295         case 512:
296                 switch (dev->se_sub_dev->se_dev_attrib.block_size) {
297                 case 4096:
298                         blocks_long >>= 3;
299                         break;
300                 case 2048:
301                         blocks_long >>= 2;
302                         break;
303                 case 1024:
304                         blocks_long >>= 1;
305                         break;
306                 default:
307                         break;
308                 }
309                 break;
310         default:
311                 break;
312         }
313
314         return blocks_long;
315 }
316
317 static void iblock_end_io_flush(struct bio *bio, int err)
318 {
319         struct se_cmd *cmd = bio->bi_private;
320
321         if (err)
322                 pr_err("IBLOCK: cache flush failed: %d\n", err);
323
324         if (cmd)
325                 transport_complete_sync_cache(cmd, err == 0);
326         bio_put(bio);
327 }
328
329 /*
330  * Implement SYCHRONIZE CACHE.  Note that we can't handle lba ranges and must
331  * always flush the whole cache.
332  */
333 static void iblock_emulate_sync_cache(struct se_task *task)
334 {
335         struct se_cmd *cmd = task->task_se_cmd;
336         struct iblock_dev *ib_dev = cmd->se_dev->dev_ptr;
337         int immed = (cmd->t_task_cdb[1] & 0x2);
338         struct bio *bio;
339
340         /*
341          * If the Immediate bit is set, queue up the GOOD response
342          * for this SYNCHRONIZE_CACHE op.
343          */
344         if (immed)
345                 transport_complete_sync_cache(cmd, 1);
346
347         bio = bio_alloc(GFP_KERNEL, 0);
348         bio->bi_end_io = iblock_end_io_flush;
349         bio->bi_bdev = ib_dev->ibd_bd;
350         if (!immed)
351                 bio->bi_private = cmd;
352         submit_bio(WRITE_FLUSH, bio);
353 }
354
355 static int iblock_do_discard(struct se_device *dev, sector_t lba, u32 range)
356 {
357         struct iblock_dev *ibd = dev->dev_ptr;
358         struct block_device *bd = ibd->ibd_bd;
359         int barrier = 0;
360
361         return blkdev_issue_discard(bd, lba, range, GFP_KERNEL, barrier);
362 }
363
364 static void iblock_free_task(struct se_task *task)
365 {
366         kfree(IBLOCK_REQ(task));
367 }
368
369 enum {
370         Opt_udev_path, Opt_force, Opt_err
371 };
372
373 static match_table_t tokens = {
374         {Opt_udev_path, "udev_path=%s"},
375         {Opt_force, "force=%d"},
376         {Opt_err, NULL}
377 };
378
379 static ssize_t iblock_set_configfs_dev_params(struct se_hba *hba,
380                                                struct se_subsystem_dev *se_dev,
381                                                const char *page, ssize_t count)
382 {
383         struct iblock_dev *ib_dev = se_dev->se_dev_su_ptr;
384         char *orig, *ptr, *arg_p, *opts;
385         substring_t args[MAX_OPT_ARGS];
386         int ret = 0, token;
387
388         opts = kstrdup(page, GFP_KERNEL);
389         if (!opts)
390                 return -ENOMEM;
391
392         orig = opts;
393
394         while ((ptr = strsep(&opts, ",")) != NULL) {
395                 if (!*ptr)
396                         continue;
397
398                 token = match_token(ptr, tokens, args);
399                 switch (token) {
400                 case Opt_udev_path:
401                         if (ib_dev->ibd_bd) {
402                                 pr_err("Unable to set udev_path= while"
403                                         " ib_dev->ibd_bd exists\n");
404                                 ret = -EEXIST;
405                                 goto out;
406                         }
407                         arg_p = match_strdup(&args[0]);
408                         if (!arg_p) {
409                                 ret = -ENOMEM;
410                                 break;
411                         }
412                         snprintf(ib_dev->ibd_udev_path, SE_UDEV_PATH_LEN,
413                                         "%s", arg_p);
414                         kfree(arg_p);
415                         pr_debug("IBLOCK: Referencing UDEV path: %s\n",
416                                         ib_dev->ibd_udev_path);
417                         ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH;
418                         break;
419                 case Opt_force:
420                         break;
421                 default:
422                         break;
423                 }
424         }
425
426 out:
427         kfree(orig);
428         return (!ret) ? count : ret;
429 }
430
431 static ssize_t iblock_check_configfs_dev_params(
432         struct se_hba *hba,
433         struct se_subsystem_dev *se_dev)
434 {
435         struct iblock_dev *ibd = se_dev->se_dev_su_ptr;
436
437         if (!(ibd->ibd_flags & IBDF_HAS_UDEV_PATH)) {
438                 pr_err("Missing udev_path= parameters for IBLOCK\n");
439                 return -EINVAL;
440         }
441
442         return 0;
443 }
444
445 static ssize_t iblock_show_configfs_dev_params(
446         struct se_hba *hba,
447         struct se_subsystem_dev *se_dev,
448         char *b)
449 {
450         struct iblock_dev *ibd = se_dev->se_dev_su_ptr;
451         struct block_device *bd = ibd->ibd_bd;
452         char buf[BDEVNAME_SIZE];
453         ssize_t bl = 0;
454
455         if (bd)
456                 bl += sprintf(b + bl, "iBlock device: %s",
457                                 bdevname(bd, buf));
458         if (ibd->ibd_flags & IBDF_HAS_UDEV_PATH) {
459                 bl += sprintf(b + bl, "  UDEV PATH: %s\n",
460                                 ibd->ibd_udev_path);
461         } else
462                 bl += sprintf(b + bl, "\n");
463
464         bl += sprintf(b + bl, "        ");
465         if (bd) {
466                 bl += sprintf(b + bl, "Major: %d Minor: %d  %s\n",
467                         MAJOR(bd->bd_dev), MINOR(bd->bd_dev), (!bd->bd_contains) ?
468                         "" : (bd->bd_holder == (struct iblock_dev *)ibd) ?
469                         "CLAIMED: IBLOCK" : "CLAIMED: OS");
470         } else {
471                 bl += sprintf(b + bl, "Major: 0 Minor: 0\n");
472         }
473
474         return bl;
475 }
476
477 static void iblock_bio_destructor(struct bio *bio)
478 {
479         struct se_task *task = bio->bi_private;
480         struct iblock_dev *ib_dev = task->task_se_cmd->se_dev->dev_ptr;
481
482         bio_free(bio, ib_dev->ibd_bio_set);
483 }
484
485 static struct bio *
486 iblock_get_bio(struct se_task *task, sector_t lba, u32 sg_num)
487 {
488         struct iblock_dev *ib_dev = task->task_se_cmd->se_dev->dev_ptr;
489         struct iblock_req *ib_req = IBLOCK_REQ(task);
490         struct bio *bio;
491
492         bio = bio_alloc_bioset(GFP_NOIO, sg_num, ib_dev->ibd_bio_set);
493         if (!bio) {
494                 pr_err("Unable to allocate memory for bio\n");
495                 return NULL;
496         }
497
498         pr_debug("Allocated bio: %p task_sg_nents: %u using ibd_bio_set:"
499                 " %p\n", bio, task->task_sg_nents, ib_dev->ibd_bio_set);
500         pr_debug("Allocated bio: %p task_size: %u\n", bio, task->task_size);
501
502         bio->bi_bdev = ib_dev->ibd_bd;
503         bio->bi_private = task;
504         bio->bi_destructor = iblock_bio_destructor;
505         bio->bi_end_io = &iblock_bio_done;
506         bio->bi_sector = lba;
507         atomic_inc(&ib_req->ib_bio_cnt);
508
509         pr_debug("Set bio->bi_sector: %llu\n", (unsigned long long)bio->bi_sector);
510         pr_debug("Set ib_req->ib_bio_cnt: %d\n",
511                         atomic_read(&ib_req->ib_bio_cnt));
512         return bio;
513 }
514
515 static int iblock_do_task(struct se_task *task)
516 {
517         struct se_cmd *cmd = task->task_se_cmd;
518         struct se_device *dev = cmd->se_dev;
519         struct bio *bio;
520         struct bio_list list;
521         struct scatterlist *sg;
522         u32 i, sg_num = task->task_sg_nents;
523         sector_t block_lba;
524         struct blk_plug plug;
525         int rw;
526
527         if (task->task_data_direction == DMA_TO_DEVICE) {
528                 /*
529                  * Force data to disk if we pretend to not have a volatile
530                  * write cache, or the initiator set the Force Unit Access bit.
531                  */
532                 if (dev->se_sub_dev->se_dev_attrib.emulate_write_cache == 0 ||
533                     (dev->se_sub_dev->se_dev_attrib.emulate_fua_write > 0 &&
534                      (cmd->se_cmd_flags & SCF_FUA)))
535                         rw = WRITE_FUA;
536                 else
537                         rw = WRITE;
538         } else {
539                 rw = READ;
540         }
541
542         /*
543          * Do starting conversion up from non 512-byte blocksize with
544          * struct se_task SCSI blocksize into Linux/Block 512 units for BIO.
545          */
546         if (dev->se_sub_dev->se_dev_attrib.block_size == 4096)
547                 block_lba = (task->task_lba << 3);
548         else if (dev->se_sub_dev->se_dev_attrib.block_size == 2048)
549                 block_lba = (task->task_lba << 2);
550         else if (dev->se_sub_dev->se_dev_attrib.block_size == 1024)
551                 block_lba = (task->task_lba << 1);
552         else if (dev->se_sub_dev->se_dev_attrib.block_size == 512)
553                 block_lba = task->task_lba;
554         else {
555                 pr_err("Unsupported SCSI -> BLOCK LBA conversion:"
556                                 " %u\n", dev->se_sub_dev->se_dev_attrib.block_size);
557                 cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
558                 return -ENOSYS;
559         }
560
561         bio = iblock_get_bio(task, block_lba, sg_num);
562         if (!bio) {
563                 cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
564                 return -ENOMEM;
565         }
566
567         bio_list_init(&list);
568         bio_list_add(&list, bio);
569
570         for_each_sg(task->task_sg, sg, task->task_sg_nents, i) {
571                 /*
572                  * XXX: if the length the device accepts is shorter than the
573                  *      length of the S/G list entry this will cause and
574                  *      endless loop.  Better hope no driver uses huge pages.
575                  */
576                 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
577                                 != sg->length) {
578                         bio = iblock_get_bio(task, block_lba, sg_num);
579                         if (!bio)
580                                 goto fail;
581                         bio_list_add(&list, bio);
582                 }
583
584                 /* Always in 512 byte units for Linux/Block */
585                 block_lba += sg->length >> IBLOCK_LBA_SHIFT;
586                 sg_num--;
587         }
588
589         blk_start_plug(&plug);
590         while ((bio = bio_list_pop(&list)))
591                 submit_bio(rw, bio);
592         blk_finish_plug(&plug);
593
594         return 0;
595
596 fail:
597         while ((bio = bio_list_pop(&list)))
598                 bio_put(bio);
599         cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
600         return -ENOMEM;
601 }
602
603 static u32 iblock_get_device_rev(struct se_device *dev)
604 {
605         return SCSI_SPC_2; /* Returns SPC-3 in Initiator Data */
606 }
607
608 static u32 iblock_get_device_type(struct se_device *dev)
609 {
610         return TYPE_DISK;
611 }
612
613 static sector_t iblock_get_blocks(struct se_device *dev)
614 {
615         struct iblock_dev *ibd = dev->dev_ptr;
616         struct block_device *bd = ibd->ibd_bd;
617         struct request_queue *q = bdev_get_queue(bd);
618
619         return iblock_emulate_read_cap_with_block_size(dev, bd, q);
620 }
621
622 static void iblock_bio_done(struct bio *bio, int err)
623 {
624         struct se_task *task = bio->bi_private;
625         struct iblock_req *ibr = IBLOCK_REQ(task);
626
627         /*
628          * Set -EIO if !BIO_UPTODATE and the passed is still err=0
629          */
630         if (!test_bit(BIO_UPTODATE, &bio->bi_flags) && !err)
631                 err = -EIO;
632
633         if (err != 0) {
634                 pr_err("test_bit(BIO_UPTODATE) failed for bio: %p,"
635                         " err: %d\n", bio, err);
636                 /*
637                  * Bump the ib_bio_err_cnt and release bio.
638                  */
639                 atomic_inc(&ibr->ib_bio_err_cnt);
640                 smp_mb__after_atomic_inc();
641         }
642
643         bio_put(bio);
644
645         if (!atomic_dec_and_test(&ibr->ib_bio_cnt))
646                 return;
647
648         pr_debug("done[%p] bio: %p task_lba: %llu bio_lba: %llu err=%d\n",
649                  task, bio, task->task_lba,
650                  (unsigned long long)bio->bi_sector, err);
651
652         transport_complete_task(task, !atomic_read(&ibr->ib_bio_err_cnt));
653 }
654
655 static struct se_subsystem_api iblock_template = {
656         .name                   = "iblock",
657         .owner                  = THIS_MODULE,
658         .transport_type         = TRANSPORT_PLUGIN_VHBA_PDEV,
659         .write_cache_emulated   = 1,
660         .fua_write_emulated     = 1,
661         .attach_hba             = iblock_attach_hba,
662         .detach_hba             = iblock_detach_hba,
663         .allocate_virtdevice    = iblock_allocate_virtdevice,
664         .create_virtdevice      = iblock_create_virtdevice,
665         .free_device            = iblock_free_device,
666         .alloc_task             = iblock_alloc_task,
667         .do_task                = iblock_do_task,
668         .do_discard             = iblock_do_discard,
669         .do_sync_cache          = iblock_emulate_sync_cache,
670         .free_task              = iblock_free_task,
671         .check_configfs_dev_params = iblock_check_configfs_dev_params,
672         .set_configfs_dev_params = iblock_set_configfs_dev_params,
673         .show_configfs_dev_params = iblock_show_configfs_dev_params,
674         .get_device_rev         = iblock_get_device_rev,
675         .get_device_type        = iblock_get_device_type,
676         .get_blocks             = iblock_get_blocks,
677 };
678
679 static int __init iblock_module_init(void)
680 {
681         return transport_subsystem_register(&iblock_template);
682 }
683
684 static void iblock_module_exit(void)
685 {
686         transport_subsystem_release(&iblock_template);
687 }
688
689 MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin");
690 MODULE_AUTHOR("nab@Linux-iSCSI.org");
691 MODULE_LICENSE("GPL");
692
693 module_init(iblock_module_init);
694 module_exit(iblock_module_exit);