1/*******************************************************************************
2 * Filename:  target_core_iblock.c
3 *
4 * This file contains the Storage Engine  <-> Linux BlockIO transport
5 * specific functions.
6 *
7 * (c) Copyright 2003-2013 Datera, Inc.
8 *
9 * Nicholas A. Bellinger <nab@kernel.org>
10 *
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.
15 *
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.
20 *
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.
24 *
25 ******************************************************************************/
26
27#include <linux/string.h>
28#include <linux/parser.h>
29#include <linux/timer.h>
30#include <linux/fs.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>
40
41#include <target/target_core_base.h>
42#include <target/target_core_backend.h>
43
44#include "target_core_iblock.h"
45
46#define IBLOCK_MAX_BIO_PER_TASK	 32	/* max # of bios to submit at a time */
47#define IBLOCK_BIO_POOL_SIZE	128
48
49static inline struct iblock_dev *IBLOCK_DEV(struct se_device *dev)
50{
51	return container_of(dev, struct iblock_dev, dev);
52}
53
54
55static int iblock_attach_hba(struct se_hba *hba, u32 host_id)
56{
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);
60	return 0;
61}
62
63static void iblock_detach_hba(struct se_hba *hba)
64{
65}
66
67static struct se_device *iblock_alloc_device(struct se_hba *hba, const char *name)
68{
69	struct iblock_dev *ib_dev = NULL;
70
71	ib_dev = kzalloc(sizeof(struct iblock_dev), GFP_KERNEL);
72	if (!ib_dev) {
73		pr_err("Unable to allocate struct iblock_dev\n");
74		return NULL;
75	}
76
77	pr_debug( "IBLOCK: Allocated ib_dev for %s\n", name);
78
79	return &ib_dev->dev;
80}
81
82static int iblock_configure_device(struct se_device *dev)
83{
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;
88	fmode_t mode;
89	int ret = -ENOMEM;
90
91	if (!(ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)) {
92		pr_err("Missing udev_path= parameters for IBLOCK\n");
93		return -EINVAL;
94	}
95
96	ib_dev->ibd_bio_set = bioset_create(IBLOCK_BIO_POOL_SIZE, 0);
97	if (!ib_dev->ibd_bio_set) {
98		pr_err("IBLOCK: Unable to create bioset\n");
99		goto out;
100	}
101
102	pr_debug( "IBLOCK: Claiming struct block_device: %s\n",
103			ib_dev->ibd_udev_path);
104
105	mode = FMODE_READ|FMODE_EXCL;
106	if (!ib_dev->ibd_readonly)
107		mode |= FMODE_WRITE;
108	else
109		dev->dev_flags |= DF_READ_ONLY;
110
111	bd = blkdev_get_by_path(ib_dev->ibd_udev_path, mode, ib_dev);
112	if (IS_ERR(bd)) {
113		ret = PTR_ERR(bd);
114		goto out_free_bioset;
115	}
116	ib_dev->ibd_bd = bd;
117
118	q = bdev_get_queue(bd);
119
120	dev->dev_attrib.hw_block_size = bdev_logical_block_size(bd);
121	dev->dev_attrib.hw_max_sectors = queue_max_hw_sectors(q);
122	dev->dev_attrib.hw_queue_depth = q->nr_requests;
123
124	if (target_configure_unmap_from_queue(&dev->dev_attrib, q,
125					      dev->dev_attrib.hw_block_size))
126		pr_debug("IBLOCK: BLOCK Discard support available,"
127			 " disabled by default\n");
128
129	/*
130	 * Enable write same emulation for IBLOCK and use 0xFFFF as
131	 * the smaller WRITE_SAME(10) only has a two-byte block count.
132	 */
133	dev->dev_attrib.max_write_same_len = 0xFFFF;
134
135	if (blk_queue_nonrot(q))
136		dev->dev_attrib.is_nonrot = 1;
137
138	bi = bdev_get_integrity(bd);
139	if (bi) {
140		struct bio_set *bs = ib_dev->ibd_bio_set;
141
142		if (!strcmp(bi->profile->name, "T10-DIF-TYPE3-IP") ||
143		    !strcmp(bi->profile->name, "T10-DIF-TYPE1-IP")) {
144			pr_err("IBLOCK export of blk_integrity: %s not"
145			       " supported\n", bi->profile->name);
146			ret = -ENOSYS;
147			goto out_blkdev_put;
148		}
149
150		if (!strcmp(bi->profile->name, "T10-DIF-TYPE3-CRC")) {
151			dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE3_PROT;
152		} else if (!strcmp(bi->profile->name, "T10-DIF-TYPE1-CRC")) {
153			dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE1_PROT;
154		}
155
156		if (dev->dev_attrib.pi_prot_type) {
157			if (bioset_integrity_create(bs, IBLOCK_BIO_POOL_SIZE) < 0) {
158				pr_err("Unable to allocate bioset for PI\n");
159				ret = -ENOMEM;
160				goto out_blkdev_put;
161			}
162			pr_debug("IBLOCK setup BIP bs->bio_integrity_pool: %p\n",
163				 bs->bio_integrity_pool);
164		}
165		dev->dev_attrib.hw_pi_prot_type = dev->dev_attrib.pi_prot_type;
166	}
167
168	return 0;
169
170out_blkdev_put:
171	blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
172out_free_bioset:
173	bioset_free(ib_dev->ibd_bio_set);
174	ib_dev->ibd_bio_set = NULL;
175out:
176	return ret;
177}
178
179static void iblock_dev_call_rcu(struct rcu_head *p)
180{
181	struct se_device *dev = container_of(p, struct se_device, rcu_head);
182	struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
183
184	kfree(ib_dev);
185}
186
187static void iblock_free_device(struct se_device *dev)
188{
189	struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
190
191	if (ib_dev->ibd_bd != NULL)
192		blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
193	if (ib_dev->ibd_bio_set != NULL)
194		bioset_free(ib_dev->ibd_bio_set);
195
196	call_rcu(&dev->rcu_head, iblock_dev_call_rcu);
197}
198
199static unsigned long long iblock_emulate_read_cap_with_block_size(
200	struct se_device *dev,
201	struct block_device *bd,
202	struct request_queue *q)
203{
204	unsigned long long blocks_long = (div_u64(i_size_read(bd->bd_inode),
205					bdev_logical_block_size(bd)) - 1);
206	u32 block_size = bdev_logical_block_size(bd);
207
208	if (block_size == dev->dev_attrib.block_size)
209		return blocks_long;
210
211	switch (block_size) {
212	case 4096:
213		switch (dev->dev_attrib.block_size) {
214		case 2048:
215			blocks_long <<= 1;
216			break;
217		case 1024:
218			blocks_long <<= 2;
219			break;
220		case 512:
221			blocks_long <<= 3;
222		default:
223			break;
224		}
225		break;
226	case 2048:
227		switch (dev->dev_attrib.block_size) {
228		case 4096:
229			blocks_long >>= 1;
230			break;
231		case 1024:
232			blocks_long <<= 1;
233			break;
234		case 512:
235			blocks_long <<= 2;
236			break;
237		default:
238			break;
239		}
240		break;
241	case 1024:
242		switch (dev->dev_attrib.block_size) {
243		case 4096:
244			blocks_long >>= 2;
245			break;
246		case 2048:
247			blocks_long >>= 1;
248			break;
249		case 512:
250			blocks_long <<= 1;
251			break;
252		default:
253			break;
254		}
255		break;
256	case 512:
257		switch (dev->dev_attrib.block_size) {
258		case 4096:
259			blocks_long >>= 3;
260			break;
261		case 2048:
262			blocks_long >>= 2;
263			break;
264		case 1024:
265			blocks_long >>= 1;
266			break;
267		default:
268			break;
269		}
270		break;
271	default:
272		break;
273	}
274
275	return blocks_long;
276}
277
278static void iblock_complete_cmd(struct se_cmd *cmd)
279{
280	struct iblock_req *ibr = cmd->priv;
281	u8 status;
282
283	if (!atomic_dec_and_test(&ibr->pending))
284		return;
285
286	if (atomic_read(&ibr->ib_bio_err_cnt))
287		status = SAM_STAT_CHECK_CONDITION;
288	else
289		status = SAM_STAT_GOOD;
290
291	target_complete_cmd(cmd, status);
292	kfree(ibr);
293}
294
295static void iblock_bio_done(struct bio *bio)
296{
297	struct se_cmd *cmd = bio->bi_private;
298	struct iblock_req *ibr = cmd->priv;
299
300	if (bio->bi_error) {
301		pr_err("bio error: %p,  err: %d\n", bio, bio->bi_error);
302		/*
303		 * Bump the ib_bio_err_cnt and release bio.
304		 */
305		atomic_inc(&ibr->ib_bio_err_cnt);
306		smp_mb__after_atomic();
307	}
308
309	bio_put(bio);
310
311	iblock_complete_cmd(cmd);
312}
313
314static struct bio *
315iblock_get_bio(struct se_cmd *cmd, sector_t lba, u32 sg_num)
316{
317	struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
318	struct bio *bio;
319
320	/*
321	 * Only allocate as many vector entries as the bio code allows us to,
322	 * we'll loop later on until we have handled the whole request.
323	 */
324	if (sg_num > BIO_MAX_PAGES)
325		sg_num = BIO_MAX_PAGES;
326
327	bio = bio_alloc_bioset(GFP_NOIO, sg_num, ib_dev->ibd_bio_set);
328	if (!bio) {
329		pr_err("Unable to allocate memory for bio\n");
330		return NULL;
331	}
332
333	bio->bi_bdev = ib_dev->ibd_bd;
334	bio->bi_private = cmd;
335	bio->bi_end_io = &iblock_bio_done;
336	bio->bi_iter.bi_sector = lba;
337
338	return bio;
339}
340
341static void iblock_submit_bios(struct bio_list *list, int rw)
342{
343	struct blk_plug plug;
344	struct bio *bio;
345
346	blk_start_plug(&plug);
347	while ((bio = bio_list_pop(list)))
348		submit_bio(rw, bio);
349	blk_finish_plug(&plug);
350}
351
352static void iblock_end_io_flush(struct bio *bio)
353{
354	struct se_cmd *cmd = bio->bi_private;
355
356	if (bio->bi_error)
357		pr_err("IBLOCK: cache flush failed: %d\n", bio->bi_error);
358
359	if (cmd) {
360		if (bio->bi_error)
361			target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
362		else
363			target_complete_cmd(cmd, SAM_STAT_GOOD);
364	}
365
366	bio_put(bio);
367}
368
369/*
370 * Implement SYCHRONIZE CACHE.  Note that we can't handle lba ranges and must
371 * always flush the whole cache.
372 */
373static sense_reason_t
374iblock_execute_sync_cache(struct se_cmd *cmd)
375{
376	struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
377	int immed = (cmd->t_task_cdb[1] & 0x2);
378	struct bio *bio;
379
380	/*
381	 * If the Immediate bit is set, queue up the GOOD response
382	 * for this SYNCHRONIZE_CACHE op.
383	 */
384	if (immed)
385		target_complete_cmd(cmd, SAM_STAT_GOOD);
386
387	bio = bio_alloc(GFP_KERNEL, 0);
388	bio->bi_end_io = iblock_end_io_flush;
389	bio->bi_bdev = ib_dev->ibd_bd;
390	if (!immed)
391		bio->bi_private = cmd;
392	submit_bio(WRITE_FLUSH, bio);
393	return 0;
394}
395
396static sense_reason_t
397iblock_execute_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
398{
399	struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
400	struct se_device *dev = cmd->se_dev;
401	int ret;
402
403	ret = blkdev_issue_discard(bdev,
404				   target_to_linux_sector(dev, lba),
405				   target_to_linux_sector(dev,  nolb),
406				   GFP_KERNEL, 0);
407	if (ret < 0) {
408		pr_err("blkdev_issue_discard() failed: %d\n", ret);
409		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
410	}
411
412	return 0;
413}
414
415static sense_reason_t
416iblock_execute_write_same(struct se_cmd *cmd)
417{
418	struct iblock_req *ibr;
419	struct scatterlist *sg;
420	struct bio *bio;
421	struct bio_list list;
422	struct se_device *dev = cmd->se_dev;
423	sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba);
424	sector_t sectors = target_to_linux_sector(dev,
425					sbc_get_write_same_sectors(cmd));
426
427	if (cmd->prot_op) {
428		pr_err("WRITE_SAME: Protection information with IBLOCK"
429		       " backends not supported\n");
430		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
431	}
432	sg = &cmd->t_data_sg[0];
433
434	if (cmd->t_data_nents > 1 ||
435	    sg->length != cmd->se_dev->dev_attrib.block_size) {
436		pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
437			" block_size: %u\n", cmd->t_data_nents, sg->length,
438			cmd->se_dev->dev_attrib.block_size);
439		return TCM_INVALID_CDB_FIELD;
440	}
441
442	ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
443	if (!ibr)
444		goto fail;
445	cmd->priv = ibr;
446
447	bio = iblock_get_bio(cmd, block_lba, 1);
448	if (!bio)
449		goto fail_free_ibr;
450
451	bio_list_init(&list);
452	bio_list_add(&list, bio);
453
454	atomic_set(&ibr->pending, 1);
455
456	while (sectors) {
457		while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
458				!= sg->length) {
459
460			bio = iblock_get_bio(cmd, block_lba, 1);
461			if (!bio)
462				goto fail_put_bios;
463
464			atomic_inc(&ibr->pending);
465			bio_list_add(&list, bio);
466		}
467
468		/* Always in 512 byte units for Linux/Block */
469		block_lba += sg->length >> IBLOCK_LBA_SHIFT;
470		sectors -= 1;
471	}
472
473	iblock_submit_bios(&list, WRITE);
474	return 0;
475
476fail_put_bios:
477	while ((bio = bio_list_pop(&list)))
478		bio_put(bio);
479fail_free_ibr:
480	kfree(ibr);
481fail:
482	return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
483}
484
485enum {
486	Opt_udev_path, Opt_readonly, Opt_force, Opt_err
487};
488
489static match_table_t tokens = {
490	{Opt_udev_path, "udev_path=%s"},
491	{Opt_readonly, "readonly=%d"},
492	{Opt_force, "force=%d"},
493	{Opt_err, NULL}
494};
495
496static ssize_t iblock_set_configfs_dev_params(struct se_device *dev,
497		const char *page, ssize_t count)
498{
499	struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
500	char *orig, *ptr, *arg_p, *opts;
501	substring_t args[MAX_OPT_ARGS];
502	int ret = 0, token;
503	unsigned long tmp_readonly;
504
505	opts = kstrdup(page, GFP_KERNEL);
506	if (!opts)
507		return -ENOMEM;
508
509	orig = opts;
510
511	while ((ptr = strsep(&opts, ",\n")) != NULL) {
512		if (!*ptr)
513			continue;
514
515		token = match_token(ptr, tokens, args);
516		switch (token) {
517		case Opt_udev_path:
518			if (ib_dev->ibd_bd) {
519				pr_err("Unable to set udev_path= while"
520					" ib_dev->ibd_bd exists\n");
521				ret = -EEXIST;
522				goto out;
523			}
524			if (match_strlcpy(ib_dev->ibd_udev_path, &args[0],
525				SE_UDEV_PATH_LEN) == 0) {
526				ret = -EINVAL;
527				break;
528			}
529			pr_debug("IBLOCK: Referencing UDEV path: %s\n",
530					ib_dev->ibd_udev_path);
531			ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH;
532			break;
533		case Opt_readonly:
534			arg_p = match_strdup(&args[0]);
535			if (!arg_p) {
536				ret = -ENOMEM;
537				break;
538			}
539			ret = kstrtoul(arg_p, 0, &tmp_readonly);
540			kfree(arg_p);
541			if (ret < 0) {
542				pr_err("kstrtoul() failed for"
543						" readonly=\n");
544				goto out;
545			}
546			ib_dev->ibd_readonly = tmp_readonly;
547			pr_debug("IBLOCK: readonly: %d\n", ib_dev->ibd_readonly);
548			break;
549		case Opt_force:
550			break;
551		default:
552			break;
553		}
554	}
555
556out:
557	kfree(orig);
558	return (!ret) ? count : ret;
559}
560
561static ssize_t iblock_show_configfs_dev_params(struct se_device *dev, char *b)
562{
563	struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
564	struct block_device *bd = ib_dev->ibd_bd;
565	char buf[BDEVNAME_SIZE];
566	ssize_t bl = 0;
567
568	if (bd)
569		bl += sprintf(b + bl, "iBlock device: %s",
570				bdevname(bd, buf));
571	if (ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)
572		bl += sprintf(b + bl, "  UDEV PATH: %s",
573				ib_dev->ibd_udev_path);
574	bl += sprintf(b + bl, "  readonly: %d\n", ib_dev->ibd_readonly);
575
576	bl += sprintf(b + bl, "        ");
577	if (bd) {
578		bl += sprintf(b + bl, "Major: %d Minor: %d  %s\n",
579			MAJOR(bd->bd_dev), MINOR(bd->bd_dev), (!bd->bd_contains) ?
580			"" : (bd->bd_holder == ib_dev) ?
581			"CLAIMED: IBLOCK" : "CLAIMED: OS");
582	} else {
583		bl += sprintf(b + bl, "Major: 0 Minor: 0\n");
584	}
585
586	return bl;
587}
588
589static int
590iblock_alloc_bip(struct se_cmd *cmd, struct bio *bio)
591{
592	struct se_device *dev = cmd->se_dev;
593	struct blk_integrity *bi;
594	struct bio_integrity_payload *bip;
595	struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
596	struct scatterlist *sg;
597	int i, rc;
598
599	bi = bdev_get_integrity(ib_dev->ibd_bd);
600	if (!bi) {
601		pr_err("Unable to locate bio_integrity\n");
602		return -ENODEV;
603	}
604
605	bip = bio_integrity_alloc(bio, GFP_NOIO, cmd->t_prot_nents);
606	if (!bip) {
607		pr_err("Unable to allocate bio_integrity_payload\n");
608		return -ENOMEM;
609	}
610
611	bip->bip_iter.bi_size = (cmd->data_length / dev->dev_attrib.block_size) *
612			 dev->prot_length;
613	bip->bip_iter.bi_sector = bio->bi_iter.bi_sector;
614
615	pr_debug("IBLOCK BIP Size: %u Sector: %llu\n", bip->bip_iter.bi_size,
616		 (unsigned long long)bip->bip_iter.bi_sector);
617
618	for_each_sg(cmd->t_prot_sg, sg, cmd->t_prot_nents, i) {
619
620		rc = bio_integrity_add_page(bio, sg_page(sg), sg->length,
621					    sg->offset);
622		if (rc != sg->length) {
623			pr_err("bio_integrity_add_page() failed; %d\n", rc);
624			return -ENOMEM;
625		}
626
627		pr_debug("Added bio integrity page: %p length: %d offset; %d\n",
628			 sg_page(sg), sg->length, sg->offset);
629	}
630
631	return 0;
632}
633
634static sense_reason_t
635iblock_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
636		  enum dma_data_direction data_direction)
637{
638	struct se_device *dev = cmd->se_dev;
639	sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba);
640	struct iblock_req *ibr;
641	struct bio *bio, *bio_start;
642	struct bio_list list;
643	struct scatterlist *sg;
644	u32 sg_num = sgl_nents;
645	unsigned bio_cnt;
646	int rw = 0;
647	int i;
648
649	if (data_direction == DMA_TO_DEVICE) {
650		struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
651		struct request_queue *q = bdev_get_queue(ib_dev->ibd_bd);
652		/*
653		 * Force writethrough using WRITE_FUA if a volatile write cache
654		 * is not enabled, or if initiator set the Force Unit Access bit.
655		 */
656		if (q->flush_flags & REQ_FUA) {
657			if (cmd->se_cmd_flags & SCF_FUA)
658				rw = WRITE_FUA;
659			else if (!(q->flush_flags & REQ_FLUSH))
660				rw = WRITE_FUA;
661			else
662				rw = WRITE;
663		} else {
664			rw = WRITE;
665		}
666	} else {
667		rw = READ;
668	}
669
670	ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
671	if (!ibr)
672		goto fail;
673	cmd->priv = ibr;
674
675	if (!sgl_nents) {
676		atomic_set(&ibr->pending, 1);
677		iblock_complete_cmd(cmd);
678		return 0;
679	}
680
681	bio = iblock_get_bio(cmd, block_lba, sgl_nents);
682	if (!bio)
683		goto fail_free_ibr;
684
685	bio_start = bio;
686	bio_list_init(&list);
687	bio_list_add(&list, bio);
688
689	atomic_set(&ibr->pending, 2);
690	bio_cnt = 1;
691
692	for_each_sg(sgl, sg, sgl_nents, i) {
693		/*
694		 * XXX: if the length the device accepts is shorter than the
695		 *	length of the S/G list entry this will cause and
696		 *	endless loop.  Better hope no driver uses huge pages.
697		 */
698		while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
699				!= sg->length) {
700			if (bio_cnt >= IBLOCK_MAX_BIO_PER_TASK) {
701				iblock_submit_bios(&list, rw);
702				bio_cnt = 0;
703			}
704
705			bio = iblock_get_bio(cmd, block_lba, sg_num);
706			if (!bio)
707				goto fail_put_bios;
708
709			atomic_inc(&ibr->pending);
710			bio_list_add(&list, bio);
711			bio_cnt++;
712		}
713
714		/* Always in 512 byte units for Linux/Block */
715		block_lba += sg->length >> IBLOCK_LBA_SHIFT;
716		sg_num--;
717	}
718
719	if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
720		int rc = iblock_alloc_bip(cmd, bio_start);
721		if (rc)
722			goto fail_put_bios;
723	}
724
725	iblock_submit_bios(&list, rw);
726	iblock_complete_cmd(cmd);
727	return 0;
728
729fail_put_bios:
730	while ((bio = bio_list_pop(&list)))
731		bio_put(bio);
732fail_free_ibr:
733	kfree(ibr);
734fail:
735	return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
736}
737
738static sector_t iblock_get_blocks(struct se_device *dev)
739{
740	struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
741	struct block_device *bd = ib_dev->ibd_bd;
742	struct request_queue *q = bdev_get_queue(bd);
743
744	return iblock_emulate_read_cap_with_block_size(dev, bd, q);
745}
746
747static sector_t iblock_get_alignment_offset_lbas(struct se_device *dev)
748{
749	struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
750	struct block_device *bd = ib_dev->ibd_bd;
751	int ret;
752
753	ret = bdev_alignment_offset(bd);
754	if (ret == -1)
755		return 0;
756
757	/* convert offset-bytes to offset-lbas */
758	return ret / bdev_logical_block_size(bd);
759}
760
761static unsigned int iblock_get_lbppbe(struct se_device *dev)
762{
763	struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
764	struct block_device *bd = ib_dev->ibd_bd;
765	int logs_per_phys = bdev_physical_block_size(bd) / bdev_logical_block_size(bd);
766
767	return ilog2(logs_per_phys);
768}
769
770static unsigned int iblock_get_io_min(struct se_device *dev)
771{
772	struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
773	struct block_device *bd = ib_dev->ibd_bd;
774
775	return bdev_io_min(bd);
776}
777
778static unsigned int iblock_get_io_opt(struct se_device *dev)
779{
780	struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
781	struct block_device *bd = ib_dev->ibd_bd;
782
783	return bdev_io_opt(bd);
784}
785
786static struct sbc_ops iblock_sbc_ops = {
787	.execute_rw		= iblock_execute_rw,
788	.execute_sync_cache	= iblock_execute_sync_cache,
789	.execute_write_same	= iblock_execute_write_same,
790	.execute_unmap		= iblock_execute_unmap,
791};
792
793static sense_reason_t
794iblock_parse_cdb(struct se_cmd *cmd)
795{
796	return sbc_parse_cdb(cmd, &iblock_sbc_ops);
797}
798
799static bool iblock_get_write_cache(struct se_device *dev)
800{
801	struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
802	struct block_device *bd = ib_dev->ibd_bd;
803	struct request_queue *q = bdev_get_queue(bd);
804
805	return q->flush_flags & REQ_FLUSH;
806}
807
808static const struct target_backend_ops iblock_ops = {
809	.name			= "iblock",
810	.inquiry_prod		= "IBLOCK",
811	.inquiry_rev		= IBLOCK_VERSION,
812	.owner			= THIS_MODULE,
813	.attach_hba		= iblock_attach_hba,
814	.detach_hba		= iblock_detach_hba,
815	.alloc_device		= iblock_alloc_device,
816	.configure_device	= iblock_configure_device,
817	.free_device		= iblock_free_device,
818	.parse_cdb		= iblock_parse_cdb,
819	.set_configfs_dev_params = iblock_set_configfs_dev_params,
820	.show_configfs_dev_params = iblock_show_configfs_dev_params,
821	.get_device_type	= sbc_get_device_type,
822	.get_blocks		= iblock_get_blocks,
823	.get_alignment_offset_lbas = iblock_get_alignment_offset_lbas,
824	.get_lbppbe		= iblock_get_lbppbe,
825	.get_io_min		= iblock_get_io_min,
826	.get_io_opt		= iblock_get_io_opt,
827	.get_write_cache	= iblock_get_write_cache,
828	.tb_dev_attrib_attrs	= sbc_attrib_attrs,
829};
830
831static int __init iblock_module_init(void)
832{
833	return transport_backend_register(&iblock_ops);
834}
835
836static void __exit iblock_module_exit(void)
837{
838	target_backend_unregister(&iblock_ops);
839}
840
841MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin");
842MODULE_AUTHOR("nab@Linux-iSCSI.org");
843MODULE_LICENSE("GPL");
844
845module_init(iblock_module_init);
846module_exit(iblock_module_exit);
847