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clk: return probe defer when DT clock not yet ready
[linux-2.6/btrfs-unstable.git] / drivers / target / target_core_iblock.c
blob554d4f75a75a6263ac7fb731804f787af64731ac
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.h>
39 #include <scsi/scsi_host.h>
40 #include <asm/unaligned.h>
41
42 #include <target/target_core_base.h>
43 #include <target/target_core_backend.h>
44
45 #include "target_core_iblock.h"
46
47 #define IBLOCK_MAX_BIO_PER_TASK 32 /* max # of bios to submit at a time */
48 #define IBLOCK_BIO_POOL_SIZE 128
49
50 static inline struct iblock_dev *IBLOCK_DEV(struct se_device *dev)
51 {
52 return container_of(dev, struct iblock_dev, dev);
53 }
54
55
56 static struct se_subsystem_api iblock_template;
57
58 /* iblock_attach_hba(): (Part of se_subsystem_api_t template)
59 *
60 *
61 */
62 static int iblock_attach_hba(struct se_hba *hba, u32 host_id)
63 {
64 pr_debug("CORE_HBA[%d] - TCM iBlock HBA Driver %s on"
65 " Generic Target Core Stack %s\n", hba->hba_id,
66 IBLOCK_VERSION, TARGET_CORE_MOD_VERSION);
67 return 0;
68 }
69
70 static void iblock_detach_hba(struct se_hba *hba)
71 {
72 }
73
74 static struct se_device *iblock_alloc_device(struct se_hba *hba, const char *name)
75 {
76 struct iblock_dev *ib_dev = NULL;
77
78 ib_dev = kzalloc(sizeof(struct iblock_dev), GFP_KERNEL);
79 if (!ib_dev) {
80 pr_err("Unable to allocate struct iblock_dev\n");
81 return NULL;
82 }
83
84 pr_debug( "IBLOCK: Allocated ib_dev for %s\n", name);
85
86 return &ib_dev->dev;
87 }
88
89 static int iblock_configure_device(struct se_device *dev)
90 {
91 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
92 struct request_queue *q;
93 struct block_device *bd = NULL;
94 struct blk_integrity *bi;
95 fmode_t mode;
96 int ret = -ENOMEM;
97
98 if (!(ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)) {
99 pr_err("Missing udev_path= parameters for IBLOCK\n");
100 return -EINVAL;
101 }
102
103 ib_dev->ibd_bio_set = bioset_create(IBLOCK_BIO_POOL_SIZE, 0);
104 if (!ib_dev->ibd_bio_set) {
105 pr_err("IBLOCK: Unable to create bioset\n");
106 goto out;
107 }
108
109 pr_debug( "IBLOCK: Claiming struct block_device: %s\n",
110 ib_dev->ibd_udev_path);
111
112 mode = FMODE_READ|FMODE_EXCL;
113 if (!ib_dev->ibd_readonly)
114 mode |= FMODE_WRITE;
115
116 bd = blkdev_get_by_path(ib_dev->ibd_udev_path, mode, ib_dev);
117 if (IS_ERR(bd)) {
118 ret = PTR_ERR(bd);
119 goto out_free_bioset;
120 }
121 ib_dev->ibd_bd = bd;
122
123 q = bdev_get_queue(bd);
124
125 dev->dev_attrib.hw_block_size = bdev_logical_block_size(bd);
126 dev->dev_attrib.hw_max_sectors = UINT_MAX;
127 dev->dev_attrib.hw_queue_depth = q->nr_requests;
128
129 /*
130 * Check if the underlying struct block_device request_queue supports
131 * the QUEUE_FLAG_DISCARD bit for UNMAP/WRITE_SAME in SCSI + TRIM
132 * in ATA and we need to set TPE=1
133 */
134 if (blk_queue_discard(q)) {
135 dev->dev_attrib.max_unmap_lba_count =
136 q->limits.max_discard_sectors;
137
138 /*
139 * Currently hardcoded to 1 in Linux/SCSI code..
140 */
141 dev->dev_attrib.max_unmap_block_desc_count = 1;
142 dev->dev_attrib.unmap_granularity =
143 q->limits.discard_granularity >> 9;
144 dev->dev_attrib.unmap_granularity_alignment =
145 q->limits.discard_alignment;
146
147 pr_debug("IBLOCK: BLOCK Discard support available,"
148 " disabled by default\n");
149 }
150 /*
151 * Enable write same emulation for IBLOCK and use 0xFFFF as
152 * the smaller WRITE_SAME(10) only has a two-byte block count.
153 */
154 dev->dev_attrib.max_write_same_len = 0xFFFF;
155
156 if (blk_queue_nonrot(q))
157 dev->dev_attrib.is_nonrot = 1;
158
159 bi = bdev_get_integrity(bd);
160 if (bi) {
161 struct bio_set *bs = ib_dev->ibd_bio_set;
162
163 if (!strcmp(bi->name, "T10-DIF-TYPE3-IP") ||
164 !strcmp(bi->name, "T10-DIF-TYPE1-IP")) {
165 pr_err("IBLOCK export of blk_integrity: %s not"
166 " supported\n", bi->name);
167 ret = -ENOSYS;
168 goto out_blkdev_put;
169 }
170
171 if (!strcmp(bi->name, "T10-DIF-TYPE3-CRC")) {
172 dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE3_PROT;
173 } else if (!strcmp(bi->name, "T10-DIF-TYPE1-CRC")) {
174 dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE1_PROT;
175 }
176
177 if (dev->dev_attrib.pi_prot_type) {
178 if (bioset_integrity_create(bs, IBLOCK_BIO_POOL_SIZE) < 0) {
179 pr_err("Unable to allocate bioset for PI\n");
180 ret = -ENOMEM;
181 goto out_blkdev_put;
182 }
183 pr_debug("IBLOCK setup BIP bs->bio_integrity_pool: %p\n",
184 bs->bio_integrity_pool);
185 }
186 dev->dev_attrib.hw_pi_prot_type = dev->dev_attrib.pi_prot_type;
187 }
188
189 return 0;
190
191 out_blkdev_put:
192 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
193 out_free_bioset:
194 bioset_free(ib_dev->ibd_bio_set);
195 ib_dev->ibd_bio_set = NULL;
196 out:
197 return ret;
198 }
199
200 static void iblock_free_device(struct se_device *dev)
201 {
202 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
203
204 if (ib_dev->ibd_bd != NULL)
205 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
206 if (ib_dev->ibd_bio_set != NULL) {
207 bioset_integrity_free(ib_dev->ibd_bio_set);
208 bioset_free(ib_dev->ibd_bio_set);
209 }
210 kfree(ib_dev);
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, int err)
310 {
311 struct se_cmd *cmd = bio->bi_private;
312 struct iblock_req *ibr = cmd->priv;
313
314 /*
315 * Set -EIO if !BIO_UPTODATE and the passed is still err=0
316 */
317 if (!test_bit(BIO_UPTODATE, &bio->bi_flags) && !err)
318 err = -EIO;
319
320 if (err != 0) {
321 pr_err("test_bit(BIO_UPTODATE) failed for bio: %p,"
322 " err: %d\n", bio, err);
323 /*
324 * Bump the ib_bio_err_cnt and release bio.
325 */
326 atomic_inc(&ibr->ib_bio_err_cnt);
327 smp_mb__after_atomic_inc();
328 }
329
330 bio_put(bio);
331
332 iblock_complete_cmd(cmd);
333 }
334
335 static struct bio *
336 iblock_get_bio(struct se_cmd *cmd, sector_t lba, u32 sg_num)
337 {
338 struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
339 struct bio *bio;
340
341 /*
342 * Only allocate as many vector entries as the bio code allows us to,
343 * we'll loop later on until we have handled the whole request.
344 */
345 if (sg_num > BIO_MAX_PAGES)
346 sg_num = BIO_MAX_PAGES;
347
348 bio = bio_alloc_bioset(GFP_NOIO, sg_num, ib_dev->ibd_bio_set);
349 if (!bio) {
350 pr_err("Unable to allocate memory for bio\n");
351 return NULL;
352 }
353
354 bio->bi_bdev = ib_dev->ibd_bd;
355 bio->bi_private = cmd;
356 bio->bi_end_io = &iblock_bio_done;
357 bio->bi_iter.bi_sector = lba;
358
359 return bio;
360 }
361
362 static void iblock_submit_bios(struct bio_list *list, int rw)
363 {
364 struct blk_plug plug;
365 struct bio *bio;
366
367 blk_start_plug(&plug);
368 while ((bio = bio_list_pop(list)))
369 submit_bio(rw, bio);
370 blk_finish_plug(&plug);
371 }
372
373 static void iblock_end_io_flush(struct bio *bio, int err)
374 {
375 struct se_cmd *cmd = bio->bi_private;
376
377 if (err)
378 pr_err("IBLOCK: cache flush failed: %d\n", err);
379
380 if (cmd) {
381 if (err)
382 target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
383 else
384 target_complete_cmd(cmd, SAM_STAT_GOOD);
385 }
386
387 bio_put(bio);
388 }
389
390 /*
391 * Implement SYCHRONIZE CACHE. Note that we can't handle lba ranges and must
392 * always flush the whole cache.
393 */
394 static sense_reason_t
395 iblock_execute_sync_cache(struct se_cmd *cmd)
396 {
397 struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
398 int immed = (cmd->t_task_cdb[1] & 0x2);
399 struct bio *bio;
400
401 /*
402 * If the Immediate bit is set, queue up the GOOD response
403 * for this SYNCHRONIZE_CACHE op.
404 */
405 if (immed)
406 target_complete_cmd(cmd, SAM_STAT_GOOD);
407
408 bio = bio_alloc(GFP_KERNEL, 0);
409 bio->bi_end_io = iblock_end_io_flush;
410 bio->bi_bdev = ib_dev->ibd_bd;
411 if (!immed)
412 bio->bi_private = cmd;
413 submit_bio(WRITE_FLUSH, bio);
414 return 0;
415 }
416
417 static sense_reason_t
418 iblock_do_unmap(struct se_cmd *cmd, void *priv,
419 sector_t lba, sector_t nolb)
420 {
421 struct block_device *bdev = priv;
422 int ret;
423
424 ret = blkdev_issue_discard(bdev, lba, nolb, GFP_KERNEL, 0);
425 if (ret < 0) {
426 pr_err("blkdev_issue_discard() failed: %d\n", ret);
427 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
428 }
429
430 return 0;
431 }
432
433 static sense_reason_t
434 iblock_execute_unmap(struct se_cmd *cmd)
435 {
436 struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
437
438 return sbc_execute_unmap(cmd, iblock_do_unmap, bdev);
439 }
440
441 static sense_reason_t
442 iblock_execute_write_same_unmap(struct se_cmd *cmd)
443 {
444 struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
445 sector_t lba = cmd->t_task_lba;
446 sector_t nolb = sbc_get_write_same_sectors(cmd);
447 int ret;
448
449 ret = iblock_do_unmap(cmd, bdev, lba, nolb);
450 if (ret)
451 return ret;
452
453 target_complete_cmd(cmd, GOOD);
454 return 0;
455 }
456
457 static sense_reason_t
458 iblock_execute_write_same(struct se_cmd *cmd)
459 {
460 struct iblock_req *ibr;
461 struct scatterlist *sg;
462 struct bio *bio;
463 struct bio_list list;
464 sector_t block_lba = cmd->t_task_lba;
465 sector_t sectors = sbc_get_write_same_sectors(cmd);
466
467 sg = &cmd->t_data_sg[0];
468
469 if (cmd->t_data_nents > 1 ||
470 sg->length != cmd->se_dev->dev_attrib.block_size) {
471 pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
472 " block_size: %u\n", cmd->t_data_nents, sg->length,
473 cmd->se_dev->dev_attrib.block_size);
474 return TCM_INVALID_CDB_FIELD;
475 }
476
477 ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
478 if (!ibr)
479 goto fail;
480 cmd->priv = ibr;
481
482 bio = iblock_get_bio(cmd, block_lba, 1);
483 if (!bio)
484 goto fail_free_ibr;
485
486 bio_list_init(&list);
487 bio_list_add(&list, bio);
488
489 atomic_set(&ibr->pending, 1);
490
491 while (sectors) {
492 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
493 != sg->length) {
494
495 bio = iblock_get_bio(cmd, block_lba, 1);
496 if (!bio)
497 goto fail_put_bios;
498
499 atomic_inc(&ibr->pending);
500 bio_list_add(&list, bio);
501 }
502
503 /* Always in 512 byte units for Linux/Block */
504 block_lba += sg->length >> IBLOCK_LBA_SHIFT;
505 sectors -= 1;
506 }
507
508 iblock_submit_bios(&list, WRITE);
509 return 0;
510
511 fail_put_bios:
512 while ((bio = bio_list_pop(&list)))
513 bio_put(bio);
514 fail_free_ibr:
515 kfree(ibr);
516 fail:
517 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
518 }
519
520 enum {
521 Opt_udev_path, Opt_readonly, Opt_force, Opt_err
522 };
523
524 static match_table_t tokens = {
525 {Opt_udev_path, "udev_path=%s"},
526 {Opt_readonly, "readonly=%d"},
527 {Opt_force, "force=%d"},
528 {Opt_err, NULL}
529 };
530
531 static ssize_t iblock_set_configfs_dev_params(struct se_device *dev,
532 const char *page, ssize_t count)
533 {
534 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
535 char *orig, *ptr, *arg_p, *opts;
536 substring_t args[MAX_OPT_ARGS];
537 int ret = 0, token;
538 unsigned long tmp_readonly;
539
540 opts = kstrdup(page, GFP_KERNEL);
541 if (!opts)
542 return -ENOMEM;
543
544 orig = opts;
545
546 while ((ptr = strsep(&opts, ",\n")) != NULL) {
547 if (!*ptr)
548 continue;
549
550 token = match_token(ptr, tokens, args);
551 switch (token) {
552 case Opt_udev_path:
553 if (ib_dev->ibd_bd) {
554 pr_err("Unable to set udev_path= while"
555 " ib_dev->ibd_bd exists\n");
556 ret = -EEXIST;
557 goto out;
558 }
559 if (match_strlcpy(ib_dev->ibd_udev_path, &args[0],
560 SE_UDEV_PATH_LEN) == 0) {
561 ret = -EINVAL;
562 break;
563 }
564 pr_debug("IBLOCK: Referencing UDEV path: %s\n",
565 ib_dev->ibd_udev_path);
566 ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH;
567 break;
568 case Opt_readonly:
569 arg_p = match_strdup(&args[0]);
570 if (!arg_p) {
571 ret = -ENOMEM;
572 break;
573 }
574 ret = kstrtoul(arg_p, 0, &tmp_readonly);
575 kfree(arg_p);
576 if (ret < 0) {
577 pr_err("kstrtoul() failed for"
578 " readonly=\n");
579 goto out;
580 }
581 ib_dev->ibd_readonly = tmp_readonly;
582 pr_debug("IBLOCK: readonly: %d\n", ib_dev->ibd_readonly);
583 break;
584 case Opt_force:
585 break;
586 default:
587 break;
588 }
589 }
590
591 out:
592 kfree(orig);
593 return (!ret) ? count : ret;
594 }
595
596 static ssize_t iblock_show_configfs_dev_params(struct se_device *dev, char *b)
597 {
598 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
599 struct block_device *bd = ib_dev->ibd_bd;
600 char buf[BDEVNAME_SIZE];
601 ssize_t bl = 0;
602
603 if (bd)
604 bl += sprintf(b + bl, "iBlock device: %s",
605 bdevname(bd, buf));
606 if (ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)
607 bl += sprintf(b + bl, " UDEV PATH: %s",
608 ib_dev->ibd_udev_path);
609 bl += sprintf(b + bl, " readonly: %d\n", ib_dev->ibd_readonly);
610
611 bl += sprintf(b + bl, " ");
612 if (bd) {
613 bl += sprintf(b + bl, "Major: %d Minor: %d %s\n",
614 MAJOR(bd->bd_dev), MINOR(bd->bd_dev), (!bd->bd_contains) ?
615 "" : (bd->bd_holder == ib_dev) ?
616 "CLAIMED: IBLOCK" : "CLAIMED: OS");
617 } else {
618 bl += sprintf(b + bl, "Major: 0 Minor: 0\n");
619 }
620
621 return bl;
622 }
623
624 static int
625 iblock_alloc_bip(struct se_cmd *cmd, struct bio *bio)
626 {
627 struct se_device *dev = cmd->se_dev;
628 struct blk_integrity *bi;
629 struct bio_integrity_payload *bip;
630 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
631 struct scatterlist *sg;
632 int i, rc;
633
634 bi = bdev_get_integrity(ib_dev->ibd_bd);
635 if (!bi) {
636 pr_err("Unable to locate bio_integrity\n");
637 return -ENODEV;
638 }
639
640 bip = bio_integrity_alloc(bio, GFP_NOIO, cmd->t_prot_nents);
641 if (!bip) {
642 pr_err("Unable to allocate bio_integrity_payload\n");
643 return -ENOMEM;
644 }
645
646 bip->bip_iter.bi_size = (cmd->data_length / dev->dev_attrib.block_size) *
647 dev->prot_length;
648 bip->bip_iter.bi_sector = bio->bi_iter.bi_sector;
649
650 pr_debug("IBLOCK BIP Size: %u Sector: %llu\n", bip->bip_iter.bi_size,
651 (unsigned long long)bip->bip_iter.bi_sector);
652
653 for_each_sg(cmd->t_prot_sg, sg, cmd->t_prot_nents, i) {
654
655 rc = bio_integrity_add_page(bio, sg_page(sg), sg->length,
656 sg->offset);
657 if (rc != sg->length) {
658 pr_err("bio_integrity_add_page() failed; %d\n", rc);
659 return -ENOMEM;
660 }
661
662 pr_debug("Added bio integrity page: %p length: %d offset; %d\n",
663 sg_page(sg), sg->length, sg->offset);
664 }
665
666 return 0;
667 }
668
669 static sense_reason_t
670 iblock_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
671 enum dma_data_direction data_direction)
672 {
673 struct se_device *dev = cmd->se_dev;
674 struct iblock_req *ibr;
675 struct bio *bio, *bio_start;
676 struct bio_list list;
677 struct scatterlist *sg;
678 u32 sg_num = sgl_nents;
679 sector_t block_lba;
680 unsigned bio_cnt;
681 int rw = 0;
682 int i;
683
684 if (data_direction == DMA_TO_DEVICE) {
685 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
686 struct request_queue *q = bdev_get_queue(ib_dev->ibd_bd);
687 /*
688 * Force writethrough using WRITE_FUA if a volatile write cache
689 * is not enabled, or if initiator set the Force Unit Access bit.
690 */
691 if (q->flush_flags & REQ_FUA) {
692 if (cmd->se_cmd_flags & SCF_FUA)
693 rw = WRITE_FUA;
694 else if (!(q->flush_flags & REQ_FLUSH))
695 rw = WRITE_FUA;
696 else
697 rw = WRITE;
698 } else {
699 rw = WRITE;
700 }
701 } else {
702 rw = READ;
703 }
704
705 /*
706 * Convert the blocksize advertised to the initiator to the 512 byte
707 * units unconditionally used by the Linux block layer.
708 */
709 if (dev->dev_attrib.block_size == 4096)
710 block_lba = (cmd->t_task_lba << 3);
711 else if (dev->dev_attrib.block_size == 2048)
712 block_lba = (cmd->t_task_lba << 2);
713 else if (dev->dev_attrib.block_size == 1024)
714 block_lba = (cmd->t_task_lba << 1);
715 else if (dev->dev_attrib.block_size == 512)
716 block_lba = cmd->t_task_lba;
717 else {
718 pr_err("Unsupported SCSI -> BLOCK LBA conversion:"
719 " %u\n", dev->dev_attrib.block_size);
720 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
721 }
722
723 ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
724 if (!ibr)
725 goto fail;
726 cmd->priv = ibr;
727
728 if (!sgl_nents) {
729 atomic_set(&ibr->pending, 1);
730 iblock_complete_cmd(cmd);
731 return 0;
732 }
733
734 bio = iblock_get_bio(cmd, block_lba, sgl_nents);
735 if (!bio)
736 goto fail_free_ibr;
737
738 bio_start = bio;
739 bio_list_init(&list);
740 bio_list_add(&list, bio);
741
742 atomic_set(&ibr->pending, 2);
743 bio_cnt = 1;
744
745 for_each_sg(sgl, sg, sgl_nents, i) {
746 /*
747 * XXX: if the length the device accepts is shorter than the
748 * length of the S/G list entry this will cause and
749 * endless loop. Better hope no driver uses huge pages.
750 */
751 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
752 != sg->length) {
753 if (bio_cnt >= IBLOCK_MAX_BIO_PER_TASK) {
754 iblock_submit_bios(&list, rw);
755 bio_cnt = 0;
756 }
757
758 bio = iblock_get_bio(cmd, block_lba, sg_num);
759 if (!bio)
760 goto fail_put_bios;
761
762 atomic_inc(&ibr->pending);
763 bio_list_add(&list, bio);
764 bio_cnt++;
765 }
766
767 /* Always in 512 byte units for Linux/Block */
768 block_lba += sg->length >> IBLOCK_LBA_SHIFT;
769 sg_num--;
770 }
771
772 if (cmd->prot_type) {
773 int rc = iblock_alloc_bip(cmd, bio_start);
774 if (rc)
775 goto fail_put_bios;
776 }
777
778 iblock_submit_bios(&list, rw);
779 iblock_complete_cmd(cmd);
780 return 0;
781
782 fail_put_bios:
783 while ((bio = bio_list_pop(&list)))
784 bio_put(bio);
785 fail_free_ibr:
786 kfree(ibr);
787 fail:
788 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
789 }
790
791 static sector_t iblock_get_blocks(struct se_device *dev)
792 {
793 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
794 struct block_device *bd = ib_dev->ibd_bd;
795 struct request_queue *q = bdev_get_queue(bd);
796
797 return iblock_emulate_read_cap_with_block_size(dev, bd, q);
798 }
799
800 static sector_t iblock_get_alignment_offset_lbas(struct se_device *dev)
801 {
802 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
803 struct block_device *bd = ib_dev->ibd_bd;
804 int ret;
805
806 ret = bdev_alignment_offset(bd);
807 if (ret == -1)
808 return 0;
809
810 /* convert offset-bytes to offset-lbas */
811 return ret / bdev_logical_block_size(bd);
812 }
813
814 static unsigned int iblock_get_lbppbe(struct se_device *dev)
815 {
816 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
817 struct block_device *bd = ib_dev->ibd_bd;
818 int logs_per_phys = bdev_physical_block_size(bd) / bdev_logical_block_size(bd);
819
820 return ilog2(logs_per_phys);
821 }
822
823 static unsigned int iblock_get_io_min(struct se_device *dev)
824 {
825 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
826 struct block_device *bd = ib_dev->ibd_bd;
827
828 return bdev_io_min(bd);
829 }
830
831 static unsigned int iblock_get_io_opt(struct se_device *dev)
832 {
833 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
834 struct block_device *bd = ib_dev->ibd_bd;
835
836 return bdev_io_opt(bd);
837 }
838
839 static struct sbc_ops iblock_sbc_ops = {
840 .execute_rw = iblock_execute_rw,
841 .execute_sync_cache = iblock_execute_sync_cache,
842 .execute_write_same = iblock_execute_write_same,
843 .execute_write_same_unmap = iblock_execute_write_same_unmap,
844 .execute_unmap = iblock_execute_unmap,
845 };
846
847 static sense_reason_t
848 iblock_parse_cdb(struct se_cmd *cmd)
849 {
850 return sbc_parse_cdb(cmd, &iblock_sbc_ops);
851 }
852
853 static bool iblock_get_write_cache(struct se_device *dev)
854 {
855 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
856 struct block_device *bd = ib_dev->ibd_bd;
857 struct request_queue *q = bdev_get_queue(bd);
858
859 return q->flush_flags & REQ_FLUSH;
860 }
861
862 static struct se_subsystem_api iblock_template = {
863 .name = "iblock",
864 .inquiry_prod = "IBLOCK",
865 .inquiry_rev = IBLOCK_VERSION,
866 .owner = THIS_MODULE,
867 .transport_type = TRANSPORT_PLUGIN_VHBA_PDEV,
868 .attach_hba = iblock_attach_hba,
869 .detach_hba = iblock_detach_hba,
870 .alloc_device = iblock_alloc_device,
871 .configure_device = iblock_configure_device,
872 .free_device = iblock_free_device,
873 .parse_cdb = iblock_parse_cdb,
874 .set_configfs_dev_params = iblock_set_configfs_dev_params,
875 .show_configfs_dev_params = iblock_show_configfs_dev_params,
876 .get_device_type = sbc_get_device_type,
877 .get_blocks = iblock_get_blocks,
878 .get_alignment_offset_lbas = iblock_get_alignment_offset_lbas,
879 .get_lbppbe = iblock_get_lbppbe,
880 .get_io_min = iblock_get_io_min,
881 .get_io_opt = iblock_get_io_opt,
882 .get_write_cache = iblock_get_write_cache,
883 };
884
885 static int __init iblock_module_init(void)
886 {
887 return transport_subsystem_register(&iblock_template);
888 }
889
890 static void __exit iblock_module_exit(void)
891 {
892 transport_subsystem_release(&iblock_template);
893 }
894
895 MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin");
896 MODULE_AUTHOR("nab@Linux-iSCSI.org");
897 MODULE_LICENSE("GPL");
898
899 module_init(iblock_module_init);
900 module_exit(iblock_module_exit);
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