summaryrefslogtreecommitdiffstats
path: root/drivers/target/target_core_iblock.c
blob: 8572eae62da7a20399216db03ea04fe9fa1dde3e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
/*******************************************************************************
 * Filename:  target_core_iblock.c
 *
 * This file contains the Storage Engine  <-> Linux BlockIO transport
 * specific functions.
 *
 * Copyright (c) 2003, 2004, 2005 PyX Technologies, Inc.
 * Copyright (c) 2005, 2006, 2007 SBE, Inc.
 * Copyright (c) 2007-2010 Rising Tide Systems
 * Copyright (c) 2008-2010 Linux-iSCSI.org
 *
 * Nicholas A. Bellinger <nab@kernel.org>
 *
 * 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 <linux/string.h>
#include <linux/parser.h>
#include <linux/timer.h>
#include <linux/fs.h>
#include <linux/blkdev.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/bio.h>
#include <linux/genhd.h>
#include <linux/file.h>
#include <linux/module.h>
#include <scsi/scsi.h>
#include <scsi/scsi_host.h>

#include <target/target_core_base.h>
#include <target/target_core_backend.h>

#include "target_core_iblock.h"

static struct se_subsystem_api iblock_template;

static void iblock_bio_done(struct bio *, int);

/*	iblock_attach_hba(): (Part of se_subsystem_api_t template)
 *
 *
 */
static int iblock_attach_hba(struct se_hba *hba, u32 host_id)
{
	struct iblock_hba *ib_host;

	ib_host = kzalloc(sizeof(struct iblock_hba), GFP_KERNEL);
	if (!ib_host) {
		pr_err("Unable to allocate memory for"
				" struct iblock_hba\n");
		return -ENOMEM;
	}

	ib_host->iblock_host_id = host_id;

	hba->hba_ptr = ib_host;

	pr_debug("CORE_HBA[%d] - TCM iBlock HBA Driver %s on"
		" Generic Target Core Stack %s\n", hba->hba_id,
		IBLOCK_VERSION, TARGET_CORE_MOD_VERSION);

	pr_debug("CORE_HBA[%d] - Attached iBlock HBA: %u to Generic\n",
		hba->hba_id, ib_host->iblock_host_id);

	return 0;
}

static void iblock_detach_hba(struct se_hba *hba)
{
	struct iblock_hba *ib_host = hba->hba_ptr;

	pr_debug("CORE_HBA[%d] - Detached iBlock HBA: %u from Generic"
		" Target Core\n", hba->hba_id, ib_host->iblock_host_id);

	kfree(ib_host);
	hba->hba_ptr = NULL;
}

static void *iblock_allocate_virtdevice(struct se_hba *hba, const char *name)
{
	struct iblock_dev *ib_dev = NULL;
	struct iblock_hba *ib_host = hba->hba_ptr;

	ib_dev = kzalloc(sizeof(struct iblock_dev), GFP_KERNEL);
	if (!ib_dev) {
		pr_err("Unable to allocate struct iblock_dev\n");
		return NULL;
	}
	ib_dev->ibd_host = ib_host;

	pr_debug( "IBLOCK: Allocated ib_dev for %s\n", name);

	return ib_dev;
}

static struct se_device *iblock_create_virtdevice(
	struct se_hba *hba,
	struct se_subsystem_dev *se_dev,
	void *p)
{
	struct iblock_dev *ib_dev = p;
	struct se_device *dev;
	struct se_dev_limits dev_limits;
	struct block_device *bd = NULL;
	struct request_queue *q;
	struct queue_limits *limits;
	u32 dev_flags = 0;
	int ret = -EINVAL;

	if (!ib_dev) {
		pr_err("Unable to locate struct iblock_dev parameter\n");
		return ERR_PTR(ret);
	}
	memset(&dev_limits, 0, sizeof(struct se_dev_limits));
	/*
	 * These settings need to be made tunable..
	 */
	ib_dev->ibd_bio_set = bioset_create(32, 0);
	if (!ib_dev->ibd_bio_set) {
		pr_err("IBLOCK: Unable to create bioset()\n");
		return ERR_PTR(-ENOMEM);
	}
	pr_debug("IBLOCK: Created bio_set()\n");
	/*
	 * iblock_check_configfs_dev_params() ensures that ib_dev->ibd_udev_path
	 * must already have been set in order for echo 1 > $HBA/$DEV/enable to run.
	 */
	pr_debug( "IBLOCK: Claiming struct block_device: %s\n",
			ib_dev->ibd_udev_path);

	bd = blkdev_get_by_path(ib_dev->ibd_udev_path,
				FMODE_WRITE|FMODE_READ|FMODE_EXCL, ib_dev);
	if (IS_ERR(bd)) {
		ret = PTR_ERR(bd);
		goto failed;
	}
	/*
	 * Setup the local scope queue_limits from struct request_queue->limits
	 * to pass into transport_add_device_to_core_hba() as struct se_dev_limits.
	 */
	q = bdev_get_queue(bd);
	limits = &dev_limits.limits;
	limits->logical_block_size = bdev_logical_block_size(bd);
	limits->max_hw_sectors = queue_max_hw_sectors(q);
	limits->max_sectors = queue_max_sectors(q);
	dev_limits.hw_queue_depth = q->nr_requests;
	dev_limits.queue_depth = q->nr_requests;

	ib_dev->ibd_bd = bd;

	dev = transport_add_device_to_core_hba(hba,
			&iblock_template, se_dev, dev_flags, ib_dev,
			&dev_limits, "IBLOCK", IBLOCK_VERSION);
	if (!dev)
		goto failed;

	/*
	 * Check if the underlying struct block_device request_queue supports
	 * the QUEUE_FLAG_DISCARD bit for UNMAP/WRITE_SAME in SCSI + TRIM
	 * in ATA and we need to set TPE=1
	 */
	if (blk_queue_discard(q)) {
		dev->se_sub_dev->se_dev_attrib.max_unmap_lba_count =
				q->limits.max_discard_sectors;
		/*
		 * Currently hardcoded to 1 in Linux/SCSI code..
		 */
		dev->se_sub_dev->se_dev_attrib.max_unmap_block_desc_count = 1;
		dev->se_sub_dev->se_dev_attrib.unmap_granularity =
				q->limits.discard_granularity >> 9;
		dev->se_sub_dev->se_dev_attrib.unmap_granularity_alignment =
				q->limits.discard_alignment;

		pr_debug("IBLOCK: BLOCK Discard support available,"
				" disabled by default\n");
	}

	if (blk_queue_nonrot(q))
		dev->se_sub_dev->se_dev_attrib.is_nonrot = 1;

	return dev;

failed:
	if (ib_dev->ibd_bio_set) {
		bioset_free(ib_dev->ibd_bio_set);
		ib_dev->ibd_bio_set = NULL;
	}
	ib_dev->ibd_bd = NULL;
	return ERR_PTR(ret);
}

static void iblock_free_device(void *p)
{
	struct iblock_dev *ib_dev = p;

	if (ib_dev->ibd_bd != NULL)
		blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
	if (ib_dev->ibd_bio_set != NULL)
		bioset_free(ib_dev->ibd_bio_set);
	kfree(ib_dev);
}

static inline struct iblock_req *IBLOCK_REQ(struct se_task *task)
{
	return container_of(task, struct iblock_req, ib_task);
}

static struct se_task *
iblock_alloc_task(unsigned char *cdb)
{
	struct iblock_req *ib_req;

	ib_req = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
	if (!ib_req) {
		pr_err("Unable to allocate memory for struct iblock_req\n");
		return NULL;
	}

	atomic_set(&ib_req->ib_bio_cnt, 0);
	return &ib_req->ib_task;
}

static unsigned long long iblock_emulate_read_cap_with_block_size(
	struct se_device *dev,
	struct block_device *bd,
	struct request_queue *q)
{
	unsigned long long blocks_long = (div_u64(i_size_read(bd->bd_inode),
					bdev_logical_block_size(bd)) - 1);
	u32 block_size = bdev_logical_block_size(bd);

	if (block_size == dev->se_sub_dev->se_dev_attrib.block_size)
		return blocks_long;

	switch (block_size) {
	case 4096:
		switch (dev->se_sub_dev->se_dev_attrib.block_size) {
		case 2048:
			blocks_long <<= 1;
			break;
		case 1024:
			blocks_long <<= 2;
			break;
		case 512:
			blocks_long <<= 3;
		default:
			break;
		}
		break;
	case 2048:
		switch (dev->se_sub_dev->se_dev_attrib.block_size) {
		case 4096:
			blocks_long >>= 1;
			break;
		case 1024:
			blocks_long <<= 1;
			break;
		case 512:
			blocks_long <<= 2;
			break;
		default:
			break;
		}
		break;
	case 1024:
		switch (dev->se_sub_dev->se_dev_attrib.block_size) {
		case 4096:
			blocks_long >>= 2;
			break;
		case 2048:
			blocks_long >>= 1;
			break;
		case 512:
			blocks_long <<= 1;
			break;
		default:
			break;
		}
		break;
	case 512:
		switch (dev->se_sub_dev->se_dev_attrib.block_size) {
		case 4096:
			blocks_long >>= 3;
			break;
		case 2048:
			blocks_long >>= 2;
			break;
		case 1024:
			blocks_long >>= 1;
			break;
		default:
			break;
		}
		break;
	default:
		break;
	}

	return blocks_long;
}

static void iblock_end_io_flush(struct bio *bio, int err)
{
	struct se_cmd *cmd = bio->bi_private;

	if (err)
		pr_err("IBLOCK: cache flush failed: %d\n", err);

	if (cmd)
		transport_complete_sync_cache(cmd, err == 0);
	bio_put(bio);
}

/*
 * Implement SYCHRONIZE CACHE.  Note that we can't handle lba ranges and must
 * always flush the whole cache.
 */
static void iblock_emulate_sync_cache(struct se_task *task)
{
	struct se_cmd *cmd = task->task_se_cmd;
	struct iblock_dev *ib_dev = cmd->se_dev->dev_ptr;
	int immed = (cmd->t_task_cdb[1] & 0x2);
	struct bio *bio;

	/*
	 * If the Immediate bit is set, queue up the GOOD response
	 * for this SYNCHRONIZE_CACHE op.
	 */
	if (immed)
		transport_complete_sync_cache(cmd, 1);

	bio = bio_alloc(GFP_KERNEL, 0);
	bio->bi_end_io = iblock_end_io_flush;
	bio->bi_bdev = ib_dev->ibd_bd;
	if (!immed)
		bio->bi_private = cmd;
	submit_bio(WRITE_FLUSH, bio);
}

static int iblock_do_discard(struct se_device *dev, sector_t lba, u32 range)
{
	struct iblock_dev *ibd = dev->dev_ptr;
	struct block_device *bd = ibd->ibd_bd;
	int barrier = 0;

	return blkdev_issue_discard(bd, lba, range, GFP_KERNEL, barrier);
}

static void iblock_free_task(struct se_task *task)
{
	kfree(IBLOCK_REQ(task));
}

enum {
	Opt_udev_path, Opt_force, Opt_err
};

static match_table_t tokens = {
	{Opt_udev_path, "udev_path=%s"},
	{Opt_force, "force=%d"},
	{Opt_err, NULL}
};

static ssize_t iblock_set_configfs_dev_params(struct se_hba *hba,
					       struct se_subsystem_dev *se_dev,
					       const char *page, ssize_t count)
{
	struct iblock_dev *ib_dev = se_dev->se_dev_su_ptr;
	char *orig, *ptr, *arg_p, *opts;
	substring_t args[MAX_OPT_ARGS];
	int ret = 0, token;

	opts = kstrdup(page, GFP_KERNEL);
	if (!opts)
		return -ENOMEM;

	orig = opts;

	while ((ptr = strsep(&opts, ",\n")) != NULL) {
		if (!*ptr)
			continue;

		token = match_token(ptr, tokens, args);
		switch (token) {
		case Opt_udev_path:
			if (ib_dev->ibd_bd) {
				pr_err("Unable to set udev_path= while"
					" ib_dev->ibd_bd exists\n");
				ret = -EEXIST;
				goto out;
			}
			arg_p = match_strdup(&args[0]);
			if (!arg_p) {
				ret = -ENOMEM;
				break;
			}
			snprintf(ib_dev->ibd_udev_path, SE_UDEV_PATH_LEN,
					"%s", arg_p);
			kfree(arg_p);
			pr_debug("IBLOCK: Referencing UDEV path: %s\n",
					ib_dev->ibd_udev_path);
			ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH;
			break;
		case Opt_force:
			break;
		default:
			break;
		}
	}

out:
	kfree(orig);
	return (!ret) ? count : ret;
}

static ssize_t iblock_check_configfs_dev_params(
	struct se_hba *hba,
	struct se_subsystem_dev *se_dev)
{
	struct iblock_dev *ibd = se_dev->se_dev_su_ptr;

	if (!(ibd->ibd_flags & IBDF_HAS_UDEV_PATH)) {
		pr_err("Missing udev_path= parameters for IBLOCK\n");
		return -EINVAL;
	}

	return 0;
}

static ssize_t iblock_show_configfs_dev_params(
	struct se_hba *hba,
	struct se_subsystem_dev *se_dev,
	char *b)
{
	struct iblock_dev *ibd = se_dev->se_dev_su_ptr;
	struct block_device *bd = ibd->ibd_bd;
	char buf[BDEVNAME_SIZE];
	ssize_t bl = 0;

	if (bd)
		bl += sprintf(b + bl, "iBlock device: %s",
				bdevname(bd, buf));
	if (ibd->ibd_flags & IBDF_HAS_UDEV_PATH) {
		bl += sprintf(b + bl, "  UDEV PATH: %s\n",
				ibd->ibd_udev_path);
	} else
		bl += sprintf(b + bl, "\n");

	bl += sprintf(b + bl, "        ");
	if (bd) {
		bl += sprintf(b + bl, "Major: %d Minor: %d  %s\n",
			MAJOR(bd->bd_dev), MINOR(bd->bd_dev), (!bd->bd_contains) ?
			"" : (bd->bd_holder == ibd) ?
			"CLAIMED: IBLOCK" : "CLAIMED: OS");
	} else {
		bl += sprintf(b + bl, "Major: 0 Minor: 0\n");
	}

	return bl;
}

static void iblock_bio_destructor(struct bio *bio)
{
	struct se_task *task = bio->bi_private;
	struct iblock_dev *ib_dev = task->task_se_cmd->se_dev->dev_ptr;

	bio_free(bio, ib_dev->ibd_bio_set);
}

static struct bio *
iblock_get_bio(struct se_task *task, sector_t lba, u32 sg_num)
{
	struct iblock_dev *ib_dev = task->task_se_cmd->se_dev->dev_ptr;
	struct iblock_req *ib_req = IBLOCK_REQ(task);
	struct bio *bio;

	/*
	 * Only allocate as many vector entries as the bio code allows us to,
	 * we'll loop later on until we have handled the whole request.
	 */
	if (sg_num > BIO_MAX_PAGES)
		sg_num = BIO_MAX_PAGES;

	bio = bio_alloc_bioset(GFP_NOIO, sg_num, ib_dev->ibd_bio_set);
	if (!bio) {
		pr_err("Unable to allocate memory for bio\n");
		return NULL;
	}

	pr_debug("Allocated bio: %p task_sg_nents: %u using ibd_bio_set:"
		" %p\n", bio, task->task_sg_nents, ib_dev->ibd_bio_set);
	pr_debug("Allocated bio: %p task_size: %u\n", bio, task->task_size);

	bio->bi_bdev = ib_dev->ibd_bd;
	bio->bi_private = task;
	bio->bi_destructor = iblock_bio_destructor;
	bio->bi_end_io = &iblock_bio_done;
	bio->bi_sector = lba;
	atomic_inc(&ib_req->ib_bio_cnt);

	pr_debug("Set bio->bi_sector: %llu\n", (unsigned long long)bio->bi_sector);
	pr_debug("Set ib_req->ib_bio_cnt: %d\n",
			atomic_read(&ib_req->ib_bio_cnt));
	return bio;
}

static int iblock_do_task(struct se_task *task)
{
	struct se_cmd *cmd = task->task_se_cmd;
	struct se_device *dev = cmd->se_dev;
	struct bio *bio;
	struct bio_list list;
	struct scatterlist *sg;
	u32 i, sg_num = task->task_sg_nents;
	sector_t block_lba;
	struct blk_plug plug;
	int rw;

	if (task->task_data_direction == DMA_TO_DEVICE) {
		/*
		 * Force data to disk if we pretend to not have a volatile
		 * write cache, or the initiator set the Force Unit Access bit.
		 */
		if (dev->se_sub_dev->se_dev_attrib.emulate_write_cache == 0 ||
		    (dev->se_sub_dev->se_dev_attrib.emulate_fua_write > 0 &&
		     (cmd->se_cmd_flags & SCF_FUA)))
			rw = WRITE_FUA;
		else
			rw = WRITE;
	} else {
		rw = READ;
	}

	/*
	 * Do starting conversion up from non 512-byte blocksize with
	 * struct se_task SCSI blocksize into Linux/Block 512 units for BIO.
	 */
	if (dev->se_sub_dev->se_dev_attrib.block_size == 4096)
		block_lba = (task->task_lba << 3);
	else if (dev->se_sub_dev->se_dev_attrib.block_size == 2048)
		block_lba = (task->task_lba << 2);
	else if (dev->se_sub_dev->se_dev_attrib.block_size == 1024)
		block_lba = (task->task_lba << 1);
	else if (dev->se_sub_dev->se_dev_attrib.block_size == 512)
		block_lba = task->task_lba;
	else {
		pr_err("Unsupported SCSI -> BLOCK LBA conversion:"
				" %u\n", dev->se_sub_dev->se_dev_attrib.block_size);
		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
		return -ENOSYS;
	}

	bio = iblock_get_bio(task, block_lba, sg_num);
	if (!bio) {
		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
		return -ENOMEM;
	}

	bio_list_init(&list);
	bio_list_add(&list, bio);

	for_each_sg(task->task_sg, sg, task->task_sg_nents, i) {
		/*
		 * XXX: if the length the device accepts is shorter than the
		 *	length of the S/G list entry this will cause and
		 *	endless loop.  Better hope no driver uses huge pages.
		 */
		while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
				!= sg->length) {
			bio = iblock_get_bio(task, block_lba, sg_num);
			if (!bio)
				goto fail;
			bio_list_add(&list, bio);
		}

		/* Always in 512 byte units for Linux/Block */
		block_lba += sg->length >> IBLOCK_LBA_SHIFT;
		sg_num--;
	}

	blk_start_plug(&plug);
	while ((bio = bio_list_pop(&list)))
		submit_bio(rw, bio);
	blk_finish_plug(&plug);

	return 0;

fail:
	while ((bio = bio_list_pop(&list)))
		bio_put(bio);
	cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
	return -ENOMEM;
}

static u32 iblock_get_device_rev(struct se_device *dev)
{
	return SCSI_SPC_2; /* Returns SPC-3 in Initiator Data */
}

static u32 iblock_get_device_type(struct se_device *dev)
{
	return TYPE_DISK;
}

static sector_t iblock_get_blocks(struct se_device *dev)
{
	struct iblock_dev *ibd = dev->dev_ptr;
	struct block_device *bd = ibd->ibd_bd;
	struct request_queue *q = bdev_get_queue(bd);

	return iblock_emulate_read_cap_with_block_size(dev, bd, q);
}

static void iblock_bio_done(struct bio *bio, int err)
{
	struct se_task *task = bio->bi_private;
	struct iblock_req *ibr = IBLOCK_REQ(task);

	/*
	 * Set -EIO if !BIO_UPTODATE and the passed is still err=0
	 */
	if (!test_bit(BIO_UPTODATE, &bio->bi_flags) && !err)
		err = -EIO;

	if (err != 0) {
		pr_err("test_bit(BIO_UPTODATE) failed for bio: %p,"
			" err: %d\n", bio, err);
		/*
		 * Bump the ib_bio_err_cnt and release bio.
		 */
		atomic_inc(&ibr->ib_bio_err_cnt);
		smp_mb__after_atomic_inc();
	}

	bio_put(bio);

	if (!atomic_dec_and_test(&ibr->ib_bio_cnt))
		return;

	pr_debug("done[%p] bio: %p task_lba: %llu bio_lba: %llu err=%d\n",
		 task, bio, task->task_lba,
		 (unsigned long long)bio->bi_sector, err);

	transport_complete_task(task, !atomic_read(&ibr->ib_bio_err_cnt));
}

static struct se_subsystem_api iblock_template = {
	.name			= "iblock",
	.owner			= THIS_MODULE,
	.transport_type		= TRANSPORT_PLUGIN_VHBA_PDEV,
	.write_cache_emulated	= 1,
	.fua_write_emulated	= 1,
	.attach_hba		= iblock_attach_hba,
	.detach_hba		= iblock_detach_hba,
	.allocate_virtdevice	= iblock_allocate_virtdevice,
	.create_virtdevice	= iblock_create_virtdevice,
	.free_device		= iblock_free_device,
	.alloc_task		= iblock_alloc_task,
	.do_task		= iblock_do_task,
	.do_discard		= iblock_do_discard,
	.do_sync_cache		= iblock_emulate_sync_cache,
	.free_task		= iblock_free_task,
	.check_configfs_dev_params = iblock_check_configfs_dev_params,
	.set_configfs_dev_params = iblock_set_configfs_dev_params,
	.show_configfs_dev_params = iblock_show_configfs_dev_params,
	.get_device_rev		= iblock_get_device_rev,
	.get_device_type	= iblock_get_device_type,
	.get_blocks		= iblock_get_blocks,
};

static int __init iblock_module_init(void)
{
	return transport_subsystem_register(&iblock_template);
}

static void iblock_module_exit(void)
{
	transport_subsystem_release(&iblock_template);
}

MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin");
MODULE_AUTHOR("nab@Linux-iSCSI.org");
MODULE_LICENSE("GPL");

module_init(iblock_module_init);
module_exit(iblock_module_exit);