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[deliverable/linux.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 * (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
49 static inline struct iblock_dev *IBLOCK_DEV(struct se_device *dev)
50 {
51 return container_of(dev, struct iblock_dev, dev);
52 }
53
54
55 static 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
63 static void iblock_detach_hba(struct se_hba *hba)
64 {
65 }
66
67 static 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
82 static 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
109 bd = blkdev_get_by_path(ib_dev->ibd_udev_path, mode, ib_dev);
110 if (IS_ERR(bd)) {
111 ret = PTR_ERR(bd);
112 goto out_free_bioset;
113 }
114 ib_dev->ibd_bd = bd;
115
116 q = bdev_get_queue(bd);
117
118 dev->dev_attrib.hw_block_size = bdev_logical_block_size(bd);
119 dev->dev_attrib.hw_max_sectors = queue_max_hw_sectors(q);
120 dev->dev_attrib.hw_queue_depth = q->nr_requests;
121
122 /*
123 * Check if the underlying struct block_device request_queue supports
124 * the QUEUE_FLAG_DISCARD bit for UNMAP/WRITE_SAME in SCSI + TRIM
125 * in ATA and we need to set TPE=1
126 */
127 if (blk_queue_discard(q)) {
128 dev->dev_attrib.max_unmap_lba_count =
129 q->limits.max_discard_sectors;
130
131 /*
132 * Currently hardcoded to 1 in Linux/SCSI code..
133 */
134 dev->dev_attrib.max_unmap_block_desc_count = 1;
135 dev->dev_attrib.unmap_granularity =
136 q->limits.discard_granularity >> 9;
137 dev->dev_attrib.unmap_granularity_alignment =
138 q->limits.discard_alignment;
139
140 pr_debug("IBLOCK: BLOCK Discard support available,"
141 " disabled by default\n");
142 }
143 /*
144 * Enable write same emulation for IBLOCK and use 0xFFFF as
145 * the smaller WRITE_SAME(10) only has a two-byte block count.
146 */
147 dev->dev_attrib.max_write_same_len = 0xFFFF;
148
149 if (blk_queue_nonrot(q))
150 dev->dev_attrib.is_nonrot = 1;
151
152 bi = bdev_get_integrity(bd);
153 if (bi) {
154 struct bio_set *bs = ib_dev->ibd_bio_set;
155
156 if (!strcmp(bi->name, "T10-DIF-TYPE3-IP") ||
157 !strcmp(bi->name, "T10-DIF-TYPE1-IP")) {
158 pr_err("IBLOCK export of blk_integrity: %s not"
159 " supported\n", bi->name);
160 ret = -ENOSYS;
161 goto out_blkdev_put;
162 }
163
164 if (!strcmp(bi->name, "T10-DIF-TYPE3-CRC")) {
165 dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE3_PROT;
166 } else if (!strcmp(bi->name, "T10-DIF-TYPE1-CRC")) {
167 dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE1_PROT;
168 }
169
170 if (dev->dev_attrib.pi_prot_type) {
171 if (bioset_integrity_create(bs, IBLOCK_BIO_POOL_SIZE) < 0) {
172 pr_err("Unable to allocate bioset for PI\n");
173 ret = -ENOMEM;
174 goto out_blkdev_put;
175 }
176 pr_debug("IBLOCK setup BIP bs->bio_integrity_pool: %p\n",
177 bs->bio_integrity_pool);
178 }
179 dev->dev_attrib.hw_pi_prot_type = dev->dev_attrib.pi_prot_type;
180 }
181
182 return 0;
183
184 out_blkdev_put:
185 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
186 out_free_bioset:
187 bioset_free(ib_dev->ibd_bio_set);
188 ib_dev->ibd_bio_set = NULL;
189 out:
190 return ret;
191 }
192
193 static void iblock_dev_call_rcu(struct rcu_head *p)
194 {
195 struct se_device *dev = container_of(p, struct se_device, rcu_head);
196 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
197
198 kfree(ib_dev);
199 }
200
201 static void iblock_free_device(struct se_device *dev)
202 {
203 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
204
205 if (ib_dev->ibd_bd != NULL)
206 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
207 if (ib_dev->ibd_bio_set != NULL)
208 bioset_free(ib_dev->ibd_bio_set);
209
210 call_rcu(&dev->rcu_head, iblock_dev_call_rcu);
211 }
212
213 static unsigned long long iblock_emulate_read_cap_with_block_size(
214 struct se_device *dev,
215 struct block_device *bd,
216 struct request_queue *q)
217 {
218 unsigned long long blocks_long = (div_u64(i_size_read(bd->bd_inode),
219 bdev_logical_block_size(bd)) - 1);
220 u32 block_size = bdev_logical_block_size(bd);
221
222 if (block_size == dev->dev_attrib.block_size)
223 return blocks_long;
224
225 switch (block_size) {
226 case 4096:
227 switch (dev->dev_attrib.block_size) {
228 case 2048:
229 blocks_long <<= 1;
230 break;
231 case 1024:
232 blocks_long <<= 2;
233 break;
234 case 512:
235 blocks_long <<= 3;
236 default:
237 break;
238 }
239 break;
240 case 2048:
241 switch (dev->dev_attrib.block_size) {
242 case 4096:
243 blocks_long >>= 1;
244 break;
245 case 1024:
246 blocks_long <<= 1;
247 break;
248 case 512:
249 blocks_long <<= 2;
250 break;
251 default:
252 break;
253 }
254 break;
255 case 1024:
256 switch (dev->dev_attrib.block_size) {
257 case 4096:
258 blocks_long >>= 2;
259 break;
260 case 2048:
261 blocks_long >>= 1;
262 break;
263 case 512:
264 blocks_long <<= 1;
265 break;
266 default:
267 break;
268 }
269 break;
270 case 512:
271 switch (dev->dev_attrib.block_size) {
272 case 4096:
273 blocks_long >>= 3;
274 break;
275 case 2048:
276 blocks_long >>= 2;
277 break;
278 case 1024:
279 blocks_long >>= 1;
280 break;
281 default:
282 break;
283 }
284 break;
285 default:
286 break;
287 }
288
289 return blocks_long;
290 }
291
292 static void iblock_complete_cmd(struct se_cmd *cmd)
293 {
294 struct iblock_req *ibr = cmd->priv;
295 u8 status;
296
297 if (!atomic_dec_and_test(&ibr->pending))
298 return;
299
300 if (atomic_read(&ibr->ib_bio_err_cnt))
301 status = SAM_STAT_CHECK_CONDITION;
302 else
303 status = SAM_STAT_GOOD;
304
305 target_complete_cmd(cmd, status);
306 kfree(ibr);
307 }
308
309 static void iblock_bio_done(struct bio *bio)
310 {
311 struct se_cmd *cmd = bio->bi_private;
312 struct iblock_req *ibr = cmd->priv;
313
314 if (bio->bi_error) {
315 pr_err("bio error: %p, err: %d\n", bio, bio->bi_error);
316 /*
317 * Bump the ib_bio_err_cnt and release bio.
318 */
319 atomic_inc(&ibr->ib_bio_err_cnt);
320 smp_mb__after_atomic();
321 }
322
323 bio_put(bio);
324
325 iblock_complete_cmd(cmd);
326 }
327
328 static struct bio *
329 iblock_get_bio(struct se_cmd *cmd, sector_t lba, u32 sg_num)
330 {
331 struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
332 struct bio *bio;
333
334 /*
335 * Only allocate as many vector entries as the bio code allows us to,
336 * we'll loop later on until we have handled the whole request.
337 */
338 if (sg_num > BIO_MAX_PAGES)
339 sg_num = BIO_MAX_PAGES;
340
341 bio = bio_alloc_bioset(GFP_NOIO, sg_num, ib_dev->ibd_bio_set);
342 if (!bio) {
343 pr_err("Unable to allocate memory for bio\n");
344 return NULL;
345 }
346
347 bio->bi_bdev = ib_dev->ibd_bd;
348 bio->bi_private = cmd;
349 bio->bi_end_io = &iblock_bio_done;
350 bio->bi_iter.bi_sector = lba;
351
352 return bio;
353 }
354
355 static void iblock_submit_bios(struct bio_list *list, int rw)
356 {
357 struct blk_plug plug;
358 struct bio *bio;
359
360 blk_start_plug(&plug);
361 while ((bio = bio_list_pop(list)))
362 submit_bio(rw, bio);
363 blk_finish_plug(&plug);
364 }
365
366 static void iblock_end_io_flush(struct bio *bio)
367 {
368 struct se_cmd *cmd = bio->bi_private;
369
370 if (bio->bi_error)
371 pr_err("IBLOCK: cache flush failed: %d\n", bio->bi_error);
372
373 if (cmd) {
374 if (bio->bi_error)
375 target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
376 else
377 target_complete_cmd(cmd, SAM_STAT_GOOD);
378 }
379
380 bio_put(bio);
381 }
382
383 /*
384 * Implement SYCHRONIZE CACHE. Note that we can't handle lba ranges and must
385 * always flush the whole cache.
386 */
387 static sense_reason_t
388 iblock_execute_sync_cache(struct se_cmd *cmd)
389 {
390 struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
391 int immed = (cmd->t_task_cdb[1] & 0x2);
392 struct bio *bio;
393
394 /*
395 * If the Immediate bit is set, queue up the GOOD response
396 * for this SYNCHRONIZE_CACHE op.
397 */
398 if (immed)
399 target_complete_cmd(cmd, SAM_STAT_GOOD);
400
401 bio = bio_alloc(GFP_KERNEL, 0);
402 bio->bi_end_io = iblock_end_io_flush;
403 bio->bi_bdev = ib_dev->ibd_bd;
404 if (!immed)
405 bio->bi_private = cmd;
406 submit_bio(WRITE_FLUSH, bio);
407 return 0;
408 }
409
410 static sense_reason_t
411 iblock_execute_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
412 {
413 struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
414 int ret;
415
416 ret = blkdev_issue_discard(bdev, lba, nolb, GFP_KERNEL, 0);
417 if (ret < 0) {
418 pr_err("blkdev_issue_discard() failed: %d\n", ret);
419 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
420 }
421
422 return 0;
423 }
424
425 static sense_reason_t
426 iblock_execute_write_same(struct se_cmd *cmd)
427 {
428 struct iblock_req *ibr;
429 struct scatterlist *sg;
430 struct bio *bio;
431 struct bio_list list;
432 sector_t block_lba = cmd->t_task_lba;
433 sector_t sectors = sbc_get_write_same_sectors(cmd);
434
435 if (cmd->prot_op) {
436 pr_err("WRITE_SAME: Protection information with IBLOCK"
437 " backends not supported\n");
438 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
439 }
440 sg = &cmd->t_data_sg[0];
441
442 if (cmd->t_data_nents > 1 ||
443 sg->length != cmd->se_dev->dev_attrib.block_size) {
444 pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
445 " block_size: %u\n", cmd->t_data_nents, sg->length,
446 cmd->se_dev->dev_attrib.block_size);
447 return TCM_INVALID_CDB_FIELD;
448 }
449
450 ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
451 if (!ibr)
452 goto fail;
453 cmd->priv = ibr;
454
455 bio = iblock_get_bio(cmd, block_lba, 1);
456 if (!bio)
457 goto fail_free_ibr;
458
459 bio_list_init(&list);
460 bio_list_add(&list, bio);
461
462 atomic_set(&ibr->pending, 1);
463
464 while (sectors) {
465 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
466 != sg->length) {
467
468 bio = iblock_get_bio(cmd, block_lba, 1);
469 if (!bio)
470 goto fail_put_bios;
471
472 atomic_inc(&ibr->pending);
473 bio_list_add(&list, bio);
474 }
475
476 /* Always in 512 byte units for Linux/Block */
477 block_lba += sg->length >> IBLOCK_LBA_SHIFT;
478 sectors -= 1;
479 }
480
481 iblock_submit_bios(&list, WRITE);
482 return 0;
483
484 fail_put_bios:
485 while ((bio = bio_list_pop(&list)))
486 bio_put(bio);
487 fail_free_ibr:
488 kfree(ibr);
489 fail:
490 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
491 }
492
493 enum {
494 Opt_udev_path, Opt_readonly, Opt_force, Opt_err
495 };
496
497 static match_table_t tokens = {
498 {Opt_udev_path, "udev_path=%s"},
499 {Opt_readonly, "readonly=%d"},
500 {Opt_force, "force=%d"},
501 {Opt_err, NULL}
502 };
503
504 static ssize_t iblock_set_configfs_dev_params(struct se_device *dev,
505 const char *page, ssize_t count)
506 {
507 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
508 char *orig, *ptr, *arg_p, *opts;
509 substring_t args[MAX_OPT_ARGS];
510 int ret = 0, token;
511 unsigned long tmp_readonly;
512
513 opts = kstrdup(page, GFP_KERNEL);
514 if (!opts)
515 return -ENOMEM;
516
517 orig = opts;
518
519 while ((ptr = strsep(&opts, ",\n")) != NULL) {
520 if (!*ptr)
521 continue;
522
523 token = match_token(ptr, tokens, args);
524 switch (token) {
525 case Opt_udev_path:
526 if (ib_dev->ibd_bd) {
527 pr_err("Unable to set udev_path= while"
528 " ib_dev->ibd_bd exists\n");
529 ret = -EEXIST;
530 goto out;
531 }
532 if (match_strlcpy(ib_dev->ibd_udev_path, &args[0],
533 SE_UDEV_PATH_LEN) == 0) {
534 ret = -EINVAL;
535 break;
536 }
537 pr_debug("IBLOCK: Referencing UDEV path: %s\n",
538 ib_dev->ibd_udev_path);
539 ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH;
540 break;
541 case Opt_readonly:
542 arg_p = match_strdup(&args[0]);
543 if (!arg_p) {
544 ret = -ENOMEM;
545 break;
546 }
547 ret = kstrtoul(arg_p, 0, &tmp_readonly);
548 kfree(arg_p);
549 if (ret < 0) {
550 pr_err("kstrtoul() failed for"
551 " readonly=\n");
552 goto out;
553 }
554 ib_dev->ibd_readonly = tmp_readonly;
555 pr_debug("IBLOCK: readonly: %d\n", ib_dev->ibd_readonly);
556 break;
557 case Opt_force:
558 break;
559 default:
560 break;
561 }
562 }
563
564 out:
565 kfree(orig);
566 return (!ret) ? count : ret;
567 }
568
569 static ssize_t iblock_show_configfs_dev_params(struct se_device *dev, char *b)
570 {
571 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
572 struct block_device *bd = ib_dev->ibd_bd;
573 char buf[BDEVNAME_SIZE];
574 ssize_t bl = 0;
575
576 if (bd)
577 bl += sprintf(b + bl, "iBlock device: %s",
578 bdevname(bd, buf));
579 if (ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)
580 bl += sprintf(b + bl, " UDEV PATH: %s",
581 ib_dev->ibd_udev_path);
582 bl += sprintf(b + bl, " readonly: %d\n", ib_dev->ibd_readonly);
583
584 bl += sprintf(b + bl, " ");
585 if (bd) {
586 bl += sprintf(b + bl, "Major: %d Minor: %d %s\n",
587 MAJOR(bd->bd_dev), MINOR(bd->bd_dev), (!bd->bd_contains) ?
588 "" : (bd->bd_holder == ib_dev) ?
589 "CLAIMED: IBLOCK" : "CLAIMED: OS");
590 } else {
591 bl += sprintf(b + bl, "Major: 0 Minor: 0\n");
592 }
593
594 return bl;
595 }
596
597 static int
598 iblock_alloc_bip(struct se_cmd *cmd, struct bio *bio)
599 {
600 struct se_device *dev = cmd->se_dev;
601 struct blk_integrity *bi;
602 struct bio_integrity_payload *bip;
603 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
604 struct scatterlist *sg;
605 int i, rc;
606
607 bi = bdev_get_integrity(ib_dev->ibd_bd);
608 if (!bi) {
609 pr_err("Unable to locate bio_integrity\n");
610 return -ENODEV;
611 }
612
613 bip = bio_integrity_alloc(bio, GFP_NOIO, cmd->t_prot_nents);
614 if (!bip) {
615 pr_err("Unable to allocate bio_integrity_payload\n");
616 return -ENOMEM;
617 }
618
619 bip->bip_iter.bi_size = (cmd->data_length / dev->dev_attrib.block_size) *
620 dev->prot_length;
621 bip->bip_iter.bi_sector = bio->bi_iter.bi_sector;
622
623 pr_debug("IBLOCK BIP Size: %u Sector: %llu\n", bip->bip_iter.bi_size,
624 (unsigned long long)bip->bip_iter.bi_sector);
625
626 for_each_sg(cmd->t_prot_sg, sg, cmd->t_prot_nents, i) {
627
628 rc = bio_integrity_add_page(bio, sg_page(sg), sg->length,
629 sg->offset);
630 if (rc != sg->length) {
631 pr_err("bio_integrity_add_page() failed; %d\n", rc);
632 return -ENOMEM;
633 }
634
635 pr_debug("Added bio integrity page: %p length: %d offset; %d\n",
636 sg_page(sg), sg->length, sg->offset);
637 }
638
639 return 0;
640 }
641
642 static sense_reason_t
643 iblock_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
644 enum dma_data_direction data_direction)
645 {
646 struct se_device *dev = cmd->se_dev;
647 struct iblock_req *ibr;
648 struct bio *bio, *bio_start;
649 struct bio_list list;
650 struct scatterlist *sg;
651 u32 sg_num = sgl_nents;
652 sector_t block_lba;
653 unsigned bio_cnt;
654 int rw = 0;
655 int i;
656
657 if (data_direction == DMA_TO_DEVICE) {
658 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
659 struct request_queue *q = bdev_get_queue(ib_dev->ibd_bd);
660 /*
661 * Force writethrough using WRITE_FUA if a volatile write cache
662 * is not enabled, or if initiator set the Force Unit Access bit.
663 */
664 if (q->flush_flags & REQ_FUA) {
665 if (cmd->se_cmd_flags & SCF_FUA)
666 rw = WRITE_FUA;
667 else if (!(q->flush_flags & REQ_FLUSH))
668 rw = WRITE_FUA;
669 else
670 rw = WRITE;
671 } else {
672 rw = WRITE;
673 }
674 } else {
675 rw = READ;
676 }
677
678 /*
679 * Convert the blocksize advertised to the initiator to the 512 byte
680 * units unconditionally used by the Linux block layer.
681 */
682 if (dev->dev_attrib.block_size == 4096)
683 block_lba = (cmd->t_task_lba << 3);
684 else if (dev->dev_attrib.block_size == 2048)
685 block_lba = (cmd->t_task_lba << 2);
686 else if (dev->dev_attrib.block_size == 1024)
687 block_lba = (cmd->t_task_lba << 1);
688 else if (dev->dev_attrib.block_size == 512)
689 block_lba = cmd->t_task_lba;
690 else {
691 pr_err("Unsupported SCSI -> BLOCK LBA conversion:"
692 " %u\n", dev->dev_attrib.block_size);
693 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
694 }
695
696 ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
697 if (!ibr)
698 goto fail;
699 cmd->priv = ibr;
700
701 if (!sgl_nents) {
702 atomic_set(&ibr->pending, 1);
703 iblock_complete_cmd(cmd);
704 return 0;
705 }
706
707 bio = iblock_get_bio(cmd, block_lba, sgl_nents);
708 if (!bio)
709 goto fail_free_ibr;
710
711 bio_start = bio;
712 bio_list_init(&list);
713 bio_list_add(&list, bio);
714
715 atomic_set(&ibr->pending, 2);
716 bio_cnt = 1;
717
718 for_each_sg(sgl, sg, sgl_nents, i) {
719 /*
720 * XXX: if the length the device accepts is shorter than the
721 * length of the S/G list entry this will cause and
722 * endless loop. Better hope no driver uses huge pages.
723 */
724 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
725 != sg->length) {
726 if (bio_cnt >= IBLOCK_MAX_BIO_PER_TASK) {
727 iblock_submit_bios(&list, rw);
728 bio_cnt = 0;
729 }
730
731 bio = iblock_get_bio(cmd, block_lba, sg_num);
732 if (!bio)
733 goto fail_put_bios;
734
735 atomic_inc(&ibr->pending);
736 bio_list_add(&list, bio);
737 bio_cnt++;
738 }
739
740 /* Always in 512 byte units for Linux/Block */
741 block_lba += sg->length >> IBLOCK_LBA_SHIFT;
742 sg_num--;
743 }
744
745 if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
746 int rc = iblock_alloc_bip(cmd, bio_start);
747 if (rc)
748 goto fail_put_bios;
749 }
750
751 iblock_submit_bios(&list, rw);
752 iblock_complete_cmd(cmd);
753 return 0;
754
755 fail_put_bios:
756 while ((bio = bio_list_pop(&list)))
757 bio_put(bio);
758 fail_free_ibr:
759 kfree(ibr);
760 fail:
761 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
762 }
763
764 static sector_t iblock_get_blocks(struct se_device *dev)
765 {
766 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
767 struct block_device *bd = ib_dev->ibd_bd;
768 struct request_queue *q = bdev_get_queue(bd);
769
770 return iblock_emulate_read_cap_with_block_size(dev, bd, q);
771 }
772
773 static sector_t iblock_get_alignment_offset_lbas(struct se_device *dev)
774 {
775 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
776 struct block_device *bd = ib_dev->ibd_bd;
777 int ret;
778
779 ret = bdev_alignment_offset(bd);
780 if (ret == -1)
781 return 0;
782
783 /* convert offset-bytes to offset-lbas */
784 return ret / bdev_logical_block_size(bd);
785 }
786
787 static unsigned int iblock_get_lbppbe(struct se_device *dev)
788 {
789 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
790 struct block_device *bd = ib_dev->ibd_bd;
791 int logs_per_phys = bdev_physical_block_size(bd) / bdev_logical_block_size(bd);
792
793 return ilog2(logs_per_phys);
794 }
795
796 static unsigned int iblock_get_io_min(struct se_device *dev)
797 {
798 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
799 struct block_device *bd = ib_dev->ibd_bd;
800
801 return bdev_io_min(bd);
802 }
803
804 static unsigned int iblock_get_io_opt(struct se_device *dev)
805 {
806 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
807 struct block_device *bd = ib_dev->ibd_bd;
808
809 return bdev_io_opt(bd);
810 }
811
812 static struct sbc_ops iblock_sbc_ops = {
813 .execute_rw = iblock_execute_rw,
814 .execute_sync_cache = iblock_execute_sync_cache,
815 .execute_write_same = iblock_execute_write_same,
816 .execute_unmap = iblock_execute_unmap,
817 };
818
819 static sense_reason_t
820 iblock_parse_cdb(struct se_cmd *cmd)
821 {
822 return sbc_parse_cdb(cmd, &iblock_sbc_ops);
823 }
824
825 static bool iblock_get_write_cache(struct se_device *dev)
826 {
827 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
828 struct block_device *bd = ib_dev->ibd_bd;
829 struct request_queue *q = bdev_get_queue(bd);
830
831 return q->flush_flags & REQ_FLUSH;
832 }
833
834 static const struct target_backend_ops iblock_ops = {
835 .name = "iblock",
836 .inquiry_prod = "IBLOCK",
837 .inquiry_rev = IBLOCK_VERSION,
838 .owner = THIS_MODULE,
839 .attach_hba = iblock_attach_hba,
840 .detach_hba = iblock_detach_hba,
841 .alloc_device = iblock_alloc_device,
842 .configure_device = iblock_configure_device,
843 .free_device = iblock_free_device,
844 .parse_cdb = iblock_parse_cdb,
845 .set_configfs_dev_params = iblock_set_configfs_dev_params,
846 .show_configfs_dev_params = iblock_show_configfs_dev_params,
847 .get_device_type = sbc_get_device_type,
848 .get_blocks = iblock_get_blocks,
849 .get_alignment_offset_lbas = iblock_get_alignment_offset_lbas,
850 .get_lbppbe = iblock_get_lbppbe,
851 .get_io_min = iblock_get_io_min,
852 .get_io_opt = iblock_get_io_opt,
853 .get_write_cache = iblock_get_write_cache,
854 .tb_dev_attrib_attrs = sbc_attrib_attrs,
855 };
856
857 static int __init iblock_module_init(void)
858 {
859 return transport_backend_register(&iblock_ops);
860 }
861
862 static void __exit iblock_module_exit(void)
863 {
864 target_backend_unregister(&iblock_ops);
865 }
866
867 MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin");
868 MODULE_AUTHOR("nab@Linux-iSCSI.org");
869 MODULE_LICENSE("GPL");
870
871 module_init(iblock_module_init);
872 module_exit(iblock_module_exit);
Linux kernel - Deliverables
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