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target: Fix max_unmap_lba_count calc overflow
[people/arne_f/kernel.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 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 pr_debug("IBLOCK: BLOCK Discard support available,"
126 " disabled by default\n");
127
128 /*
129 * Enable write same emulation for IBLOCK and use 0xFFFF as
130 * the smaller WRITE_SAME(10) only has a two-byte block count.
131 */
132 dev->dev_attrib.max_write_same_len = 0xFFFF;
133
134 if (blk_queue_nonrot(q))
135 dev->dev_attrib.is_nonrot = 1;
136
137 bi = bdev_get_integrity(bd);
138 if (bi) {
139 struct bio_set *bs = ib_dev->ibd_bio_set;
140
141 if (!strcmp(bi->profile->name, "T10-DIF-TYPE3-IP") ||
142 !strcmp(bi->profile->name, "T10-DIF-TYPE1-IP")) {
143 pr_err("IBLOCK export of blk_integrity: %s not"
144 " supported\n", bi->profile->name);
145 ret = -ENOSYS;
146 goto out_blkdev_put;
147 }
148
149 if (!strcmp(bi->profile->name, "T10-DIF-TYPE3-CRC")) {
150 dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE3_PROT;
151 } else if (!strcmp(bi->profile->name, "T10-DIF-TYPE1-CRC")) {
152 dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE1_PROT;
153 }
154
155 if (dev->dev_attrib.pi_prot_type) {
156 if (bioset_integrity_create(bs, IBLOCK_BIO_POOL_SIZE) < 0) {
157 pr_err("Unable to allocate bioset for PI\n");
158 ret = -ENOMEM;
159 goto out_blkdev_put;
160 }
161 pr_debug("IBLOCK setup BIP bs->bio_integrity_pool: %p\n",
162 bs->bio_integrity_pool);
163 }
164 dev->dev_attrib.hw_pi_prot_type = dev->dev_attrib.pi_prot_type;
165 }
166
167 return 0;
168
169 out_blkdev_put:
170 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
171 out_free_bioset:
172 bioset_free(ib_dev->ibd_bio_set);
173 ib_dev->ibd_bio_set = NULL;
174 out:
175 return ret;
176 }
177
178 static void iblock_dev_call_rcu(struct rcu_head *p)
179 {
180 struct se_device *dev = container_of(p, struct se_device, rcu_head);
181 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
182
183 kfree(ib_dev);
184 }
185
186 static void iblock_free_device(struct se_device *dev)
187 {
188 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
189
190 if (ib_dev->ibd_bd != NULL)
191 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
192 if (ib_dev->ibd_bio_set != NULL)
193 bioset_free(ib_dev->ibd_bio_set);
194
195 call_rcu(&dev->rcu_head, iblock_dev_call_rcu);
196 }
197
198 static unsigned long long iblock_emulate_read_cap_with_block_size(
199 struct se_device *dev,
200 struct block_device *bd,
201 struct request_queue *q)
202 {
203 unsigned long long blocks_long = (div_u64(i_size_read(bd->bd_inode),
204 bdev_logical_block_size(bd)) - 1);
205 u32 block_size = bdev_logical_block_size(bd);
206
207 if (block_size == dev->dev_attrib.block_size)
208 return blocks_long;
209
210 switch (block_size) {
211 case 4096:
212 switch (dev->dev_attrib.block_size) {
213 case 2048:
214 blocks_long <<= 1;
215 break;
216 case 1024:
217 blocks_long <<= 2;
218 break;
219 case 512:
220 blocks_long <<= 3;
221 default:
222 break;
223 }
224 break;
225 case 2048:
226 switch (dev->dev_attrib.block_size) {
227 case 4096:
228 blocks_long >>= 1;
229 break;
230 case 1024:
231 blocks_long <<= 1;
232 break;
233 case 512:
234 blocks_long <<= 2;
235 break;
236 default:
237 break;
238 }
239 break;
240 case 1024:
241 switch (dev->dev_attrib.block_size) {
242 case 4096:
243 blocks_long >>= 2;
244 break;
245 case 2048:
246 blocks_long >>= 1;
247 break;
248 case 512:
249 blocks_long <<= 1;
250 break;
251 default:
252 break;
253 }
254 break;
255 case 512:
256 switch (dev->dev_attrib.block_size) {
257 case 4096:
258 blocks_long >>= 3;
259 break;
260 case 2048:
261 blocks_long >>= 2;
262 break;
263 case 1024:
264 blocks_long >>= 1;
265 break;
266 default:
267 break;
268 }
269 break;
270 default:
271 break;
272 }
273
274 return blocks_long;
275 }
276
277 static void iblock_complete_cmd(struct se_cmd *cmd)
278 {
279 struct iblock_req *ibr = cmd->priv;
280 u8 status;
281
282 if (!atomic_dec_and_test(&ibr->pending))
283 return;
284
285 if (atomic_read(&ibr->ib_bio_err_cnt))
286 status = SAM_STAT_CHECK_CONDITION;
287 else
288 status = SAM_STAT_GOOD;
289
290 target_complete_cmd(cmd, status);
291 kfree(ibr);
292 }
293
294 static void iblock_bio_done(struct bio *bio)
295 {
296 struct se_cmd *cmd = bio->bi_private;
297 struct iblock_req *ibr = cmd->priv;
298
299 if (bio->bi_error) {
300 pr_err("bio error: %p, err: %d\n", bio, bio->bi_error);
301 /*
302 * Bump the ib_bio_err_cnt and release bio.
303 */
304 atomic_inc(&ibr->ib_bio_err_cnt);
305 smp_mb__after_atomic();
306 }
307
308 bio_put(bio);
309
310 iblock_complete_cmd(cmd);
311 }
312
313 static struct bio *
314 iblock_get_bio(struct se_cmd *cmd, sector_t lba, u32 sg_num)
315 {
316 struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
317 struct bio *bio;
318
319 /*
320 * Only allocate as many vector entries as the bio code allows us to,
321 * we'll loop later on until we have handled the whole request.
322 */
323 if (sg_num > BIO_MAX_PAGES)
324 sg_num = BIO_MAX_PAGES;
325
326 bio = bio_alloc_bioset(GFP_NOIO, sg_num, ib_dev->ibd_bio_set);
327 if (!bio) {
328 pr_err("Unable to allocate memory for bio\n");
329 return NULL;
330 }
331
332 bio->bi_bdev = ib_dev->ibd_bd;
333 bio->bi_private = cmd;
334 bio->bi_end_io = &iblock_bio_done;
335 bio->bi_iter.bi_sector = lba;
336
337 return bio;
338 }
339
340 static void iblock_submit_bios(struct bio_list *list, int rw)
341 {
342 struct blk_plug plug;
343 struct bio *bio;
344
345 blk_start_plug(&plug);
346 while ((bio = bio_list_pop(list)))
347 submit_bio(rw, bio);
348 blk_finish_plug(&plug);
349 }
350
351 static void iblock_end_io_flush(struct bio *bio)
352 {
353 struct se_cmd *cmd = bio->bi_private;
354
355 if (bio->bi_error)
356 pr_err("IBLOCK: cache flush failed: %d\n", bio->bi_error);
357
358 if (cmd) {
359 if (bio->bi_error)
360 target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
361 else
362 target_complete_cmd(cmd, SAM_STAT_GOOD);
363 }
364
365 bio_put(bio);
366 }
367
368 /*
369 * Implement SYCHRONIZE CACHE. Note that we can't handle lba ranges and must
370 * always flush the whole cache.
371 */
372 static sense_reason_t
373 iblock_execute_sync_cache(struct se_cmd *cmd)
374 {
375 struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
376 int immed = (cmd->t_task_cdb[1] & 0x2);
377 struct bio *bio;
378
379 /*
380 * If the Immediate bit is set, queue up the GOOD response
381 * for this SYNCHRONIZE_CACHE op.
382 */
383 if (immed)
384 target_complete_cmd(cmd, SAM_STAT_GOOD);
385
386 bio = bio_alloc(GFP_KERNEL, 0);
387 bio->bi_end_io = iblock_end_io_flush;
388 bio->bi_bdev = ib_dev->ibd_bd;
389 if (!immed)
390 bio->bi_private = cmd;
391 submit_bio(WRITE_FLUSH, bio);
392 return 0;
393 }
394
395 static sense_reason_t
396 iblock_execute_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
397 {
398 struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
399 struct se_device *dev = cmd->se_dev;
400 int ret;
401
402 ret = blkdev_issue_discard(bdev,
403 target_to_linux_sector(dev, lba),
404 target_to_linux_sector(dev, nolb),
405 GFP_KERNEL, 0);
406 if (ret < 0) {
407 pr_err("blkdev_issue_discard() failed: %d\n", ret);
408 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
409 }
410
411 return 0;
412 }
413
414 static sense_reason_t
415 iblock_execute_write_same_direct(struct block_device *bdev, struct se_cmd *cmd)
416 {
417 struct se_device *dev = cmd->se_dev;
418 struct scatterlist *sg = &cmd->t_data_sg[0];
419 struct page *page = NULL;
420 int ret;
421
422 if (sg->offset) {
423 page = alloc_page(GFP_KERNEL);
424 if (!page)
425 return TCM_OUT_OF_RESOURCES;
426 sg_copy_to_buffer(sg, cmd->t_data_nents, page_address(page),
427 dev->dev_attrib.block_size);
428 }
429
430 ret = blkdev_issue_write_same(bdev,
431 target_to_linux_sector(dev, cmd->t_task_lba),
432 target_to_linux_sector(dev,
433 sbc_get_write_same_sectors(cmd)),
434 GFP_KERNEL, page ? page : sg_page(sg));
435 if (page)
436 __free_page(page);
437 if (ret)
438 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
439
440 target_complete_cmd(cmd, GOOD);
441 return 0;
442 }
443
444 static sense_reason_t
445 iblock_execute_write_same(struct se_cmd *cmd)
446 {
447 struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
448 struct iblock_req *ibr;
449 struct scatterlist *sg;
450 struct bio *bio;
451 struct bio_list list;
452 struct se_device *dev = cmd->se_dev;
453 sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba);
454 sector_t sectors = target_to_linux_sector(dev,
455 sbc_get_write_same_sectors(cmd));
456
457 if (cmd->prot_op) {
458 pr_err("WRITE_SAME: Protection information with IBLOCK"
459 " backends not supported\n");
460 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
461 }
462 sg = &cmd->t_data_sg[0];
463
464 if (cmd->t_data_nents > 1 ||
465 sg->length != cmd->se_dev->dev_attrib.block_size) {
466 pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
467 " block_size: %u\n", cmd->t_data_nents, sg->length,
468 cmd->se_dev->dev_attrib.block_size);
469 return TCM_INVALID_CDB_FIELD;
470 }
471
472 if (bdev_write_same(bdev))
473 return iblock_execute_write_same_direct(bdev, cmd);
474
475 ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
476 if (!ibr)
477 goto fail;
478 cmd->priv = ibr;
479
480 bio = iblock_get_bio(cmd, block_lba, 1);
481 if (!bio)
482 goto fail_free_ibr;
483
484 bio_list_init(&list);
485 bio_list_add(&list, bio);
486
487 atomic_set(&ibr->pending, 1);
488
489 while (sectors) {
490 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
491 != sg->length) {
492
493 bio = iblock_get_bio(cmd, block_lba, 1);
494 if (!bio)
495 goto fail_put_bios;
496
497 atomic_inc(&ibr->pending);
498 bio_list_add(&list, bio);
499 }
500
501 /* Always in 512 byte units for Linux/Block */
502 block_lba += sg->length >> IBLOCK_LBA_SHIFT;
503 sectors -= 1;
504 }
505
506 iblock_submit_bios(&list, WRITE);
507 return 0;
508
509 fail_put_bios:
510 while ((bio = bio_list_pop(&list)))
511 bio_put(bio);
512 fail_free_ibr:
513 kfree(ibr);
514 fail:
515 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
516 }
517
518 enum {
519 Opt_udev_path, Opt_readonly, Opt_force, Opt_err
520 };
521
522 static match_table_t tokens = {
523 {Opt_udev_path, "udev_path=%s"},
524 {Opt_readonly, "readonly=%d"},
525 {Opt_force, "force=%d"},
526 {Opt_err, NULL}
527 };
528
529 static ssize_t iblock_set_configfs_dev_params(struct se_device *dev,
530 const char *page, ssize_t count)
531 {
532 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
533 char *orig, *ptr, *arg_p, *opts;
534 substring_t args[MAX_OPT_ARGS];
535 int ret = 0, token;
536 unsigned long tmp_readonly;
537
538 opts = kstrdup(page, GFP_KERNEL);
539 if (!opts)
540 return -ENOMEM;
541
542 orig = opts;
543
544 while ((ptr = strsep(&opts, ",\n")) != NULL) {
545 if (!*ptr)
546 continue;
547
548 token = match_token(ptr, tokens, args);
549 switch (token) {
550 case Opt_udev_path:
551 if (ib_dev->ibd_bd) {
552 pr_err("Unable to set udev_path= while"
553 " ib_dev->ibd_bd exists\n");
554 ret = -EEXIST;
555 goto out;
556 }
557 if (match_strlcpy(ib_dev->ibd_udev_path, &args[0],
558 SE_UDEV_PATH_LEN) == 0) {
559 ret = -EINVAL;
560 break;
561 }
562 pr_debug("IBLOCK: Referencing UDEV path: %s\n",
563 ib_dev->ibd_udev_path);
564 ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH;
565 break;
566 case Opt_readonly:
567 arg_p = match_strdup(&args[0]);
568 if (!arg_p) {
569 ret = -ENOMEM;
570 break;
571 }
572 ret = kstrtoul(arg_p, 0, &tmp_readonly);
573 kfree(arg_p);
574 if (ret < 0) {
575 pr_err("kstrtoul() failed for"
576 " readonly=\n");
577 goto out;
578 }
579 ib_dev->ibd_readonly = tmp_readonly;
580 pr_debug("IBLOCK: readonly: %d\n", ib_dev->ibd_readonly);
581 break;
582 case Opt_force:
583 break;
584 default:
585 break;
586 }
587 }
588
589 out:
590 kfree(orig);
591 return (!ret) ? count : ret;
592 }
593
594 static ssize_t iblock_show_configfs_dev_params(struct se_device *dev, char *b)
595 {
596 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
597 struct block_device *bd = ib_dev->ibd_bd;
598 char buf[BDEVNAME_SIZE];
599 ssize_t bl = 0;
600
601 if (bd)
602 bl += sprintf(b + bl, "iBlock device: %s",
603 bdevname(bd, buf));
604 if (ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)
605 bl += sprintf(b + bl, " UDEV PATH: %s",
606 ib_dev->ibd_udev_path);
607 bl += sprintf(b + bl, " readonly: %d\n", ib_dev->ibd_readonly);
608
609 bl += sprintf(b + bl, " ");
610 if (bd) {
611 bl += sprintf(b + bl, "Major: %d Minor: %d %s\n",
612 MAJOR(bd->bd_dev), MINOR(bd->bd_dev), (!bd->bd_contains) ?
613 "" : (bd->bd_holder == ib_dev) ?
614 "CLAIMED: IBLOCK" : "CLAIMED: OS");
615 } else {
616 bl += sprintf(b + bl, "Major: 0 Minor: 0\n");
617 }
618
619 return bl;
620 }
621
622 static int
623 iblock_alloc_bip(struct se_cmd *cmd, struct bio *bio)
624 {
625 struct se_device *dev = cmd->se_dev;
626 struct blk_integrity *bi;
627 struct bio_integrity_payload *bip;
628 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
629 struct scatterlist *sg;
630 int i, rc;
631
632 bi = bdev_get_integrity(ib_dev->ibd_bd);
633 if (!bi) {
634 pr_err("Unable to locate bio_integrity\n");
635 return -ENODEV;
636 }
637
638 bip = bio_integrity_alloc(bio, GFP_NOIO, cmd->t_prot_nents);
639 if (IS_ERR(bip)) {
640 pr_err("Unable to allocate bio_integrity_payload\n");
641 return PTR_ERR(bip);
642 }
643
644 bip->bip_iter.bi_size = (cmd->data_length / dev->dev_attrib.block_size) *
645 dev->prot_length;
646 bip->bip_iter.bi_sector = bio->bi_iter.bi_sector;
647
648 pr_debug("IBLOCK BIP Size: %u Sector: %llu\n", bip->bip_iter.bi_size,
649 (unsigned long long)bip->bip_iter.bi_sector);
650
651 for_each_sg(cmd->t_prot_sg, sg, cmd->t_prot_nents, i) {
652
653 rc = bio_integrity_add_page(bio, sg_page(sg), sg->length,
654 sg->offset);
655 if (rc != sg->length) {
656 pr_err("bio_integrity_add_page() failed; %d\n", rc);
657 return -ENOMEM;
658 }
659
660 pr_debug("Added bio integrity page: %p length: %d offset; %d\n",
661 sg_page(sg), sg->length, sg->offset);
662 }
663
664 return 0;
665 }
666
667 static sense_reason_t
668 iblock_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
669 enum dma_data_direction data_direction)
670 {
671 struct se_device *dev = cmd->se_dev;
672 sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba);
673 struct iblock_req *ibr;
674 struct bio *bio, *bio_start;
675 struct bio_list list;
676 struct scatterlist *sg;
677 u32 sg_num = sgl_nents;
678 unsigned bio_cnt;
679 int rw = 0;
680 int i;
681
682 if (data_direction == DMA_TO_DEVICE) {
683 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
684 struct request_queue *q = bdev_get_queue(ib_dev->ibd_bd);
685 /*
686 * Force writethrough using WRITE_FUA if a volatile write cache
687 * is not enabled, or if initiator set the Force Unit Access bit.
688 */
689 if (test_bit(QUEUE_FLAG_FUA, &q->queue_flags)) {
690 if (cmd->se_cmd_flags & SCF_FUA)
691 rw = WRITE_FUA;
692 else if (!test_bit(QUEUE_FLAG_WC, &q->queue_flags))
693 rw = WRITE_FUA;
694 else
695 rw = WRITE;
696 } else {
697 rw = WRITE;
698 }
699 } else {
700 rw = READ;
701 }
702
703 ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
704 if (!ibr)
705 goto fail;
706 cmd->priv = ibr;
707
708 if (!sgl_nents) {
709 atomic_set(&ibr->pending, 1);
710 iblock_complete_cmd(cmd);
711 return 0;
712 }
713
714 bio = iblock_get_bio(cmd, block_lba, sgl_nents);
715 if (!bio)
716 goto fail_free_ibr;
717
718 bio_start = bio;
719 bio_list_init(&list);
720 bio_list_add(&list, bio);
721
722 atomic_set(&ibr->pending, 2);
723 bio_cnt = 1;
724
725 for_each_sg(sgl, sg, sgl_nents, i) {
726 /*
727 * XXX: if the length the device accepts is shorter than the
728 * length of the S/G list entry this will cause and
729 * endless loop. Better hope no driver uses huge pages.
730 */
731 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
732 != sg->length) {
733 if (bio_cnt >= IBLOCK_MAX_BIO_PER_TASK) {
734 iblock_submit_bios(&list, rw);
735 bio_cnt = 0;
736 }
737
738 bio = iblock_get_bio(cmd, block_lba, sg_num);
739 if (!bio)
740 goto fail_put_bios;
741
742 atomic_inc(&ibr->pending);
743 bio_list_add(&list, bio);
744 bio_cnt++;
745 }
746
747 /* Always in 512 byte units for Linux/Block */
748 block_lba += sg->length >> IBLOCK_LBA_SHIFT;
749 sg_num--;
750 }
751
752 if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
753 int rc = iblock_alloc_bip(cmd, bio_start);
754 if (rc)
755 goto fail_put_bios;
756 }
757
758 iblock_submit_bios(&list, rw);
759 iblock_complete_cmd(cmd);
760 return 0;
761
762 fail_put_bios:
763 while ((bio = bio_list_pop(&list)))
764 bio_put(bio);
765 fail_free_ibr:
766 kfree(ibr);
767 fail:
768 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
769 }
770
771 static sector_t iblock_get_blocks(struct se_device *dev)
772 {
773 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
774 struct block_device *bd = ib_dev->ibd_bd;
775 struct request_queue *q = bdev_get_queue(bd);
776
777 return iblock_emulate_read_cap_with_block_size(dev, bd, q);
778 }
779
780 static sector_t iblock_get_alignment_offset_lbas(struct se_device *dev)
781 {
782 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
783 struct block_device *bd = ib_dev->ibd_bd;
784 int ret;
785
786 ret = bdev_alignment_offset(bd);
787 if (ret == -1)
788 return 0;
789
790 /* convert offset-bytes to offset-lbas */
791 return ret / bdev_logical_block_size(bd);
792 }
793
794 static unsigned int iblock_get_lbppbe(struct se_device *dev)
795 {
796 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
797 struct block_device *bd = ib_dev->ibd_bd;
798 int logs_per_phys = bdev_physical_block_size(bd) / bdev_logical_block_size(bd);
799
800 return ilog2(logs_per_phys);
801 }
802
803 static unsigned int iblock_get_io_min(struct se_device *dev)
804 {
805 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
806 struct block_device *bd = ib_dev->ibd_bd;
807
808 return bdev_io_min(bd);
809 }
810
811 static unsigned int iblock_get_io_opt(struct se_device *dev)
812 {
813 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
814 struct block_device *bd = ib_dev->ibd_bd;
815
816 return bdev_io_opt(bd);
817 }
818
819 static struct sbc_ops iblock_sbc_ops = {
820 .execute_rw = iblock_execute_rw,
821 .execute_sync_cache = iblock_execute_sync_cache,
822 .execute_write_same = iblock_execute_write_same,
823 .execute_unmap = iblock_execute_unmap,
824 };
825
826 static sense_reason_t
827 iblock_parse_cdb(struct se_cmd *cmd)
828 {
829 return sbc_parse_cdb(cmd, &iblock_sbc_ops);
830 }
831
832 static bool iblock_get_write_cache(struct se_device *dev)
833 {
834 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
835 struct block_device *bd = ib_dev->ibd_bd;
836 struct request_queue *q = bdev_get_queue(bd);
837
838 return test_bit(QUEUE_FLAG_WC, &q->queue_flags);
839 }
840
841 static const struct target_backend_ops iblock_ops = {
842 .name = "iblock",
843 .inquiry_prod = "IBLOCK",
844 .inquiry_rev = IBLOCK_VERSION,
845 .owner = THIS_MODULE,
846 .attach_hba = iblock_attach_hba,
847 .detach_hba = iblock_detach_hba,
848 .alloc_device = iblock_alloc_device,
849 .configure_device = iblock_configure_device,
850 .free_device = iblock_free_device,
851 .parse_cdb = iblock_parse_cdb,
852 .set_configfs_dev_params = iblock_set_configfs_dev_params,
853 .show_configfs_dev_params = iblock_show_configfs_dev_params,
854 .get_device_type = sbc_get_device_type,
855 .get_blocks = iblock_get_blocks,
856 .get_alignment_offset_lbas = iblock_get_alignment_offset_lbas,
857 .get_lbppbe = iblock_get_lbppbe,
858 .get_io_min = iblock_get_io_min,
859 .get_io_opt = iblock_get_io_opt,
860 .get_write_cache = iblock_get_write_cache,
861 .tb_dev_attrib_attrs = sbc_attrib_attrs,
862 };
863
864 static int __init iblock_module_init(void)
865 {
866 return transport_backend_register(&iblock_ops);
867 }
868
869 static void __exit iblock_module_exit(void)
870 {
871 target_backend_unregister(&iblock_ops);
872 }
873
874 MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin");
875 MODULE_AUTHOR("nab@Linux-iSCSI.org");
876 MODULE_LICENSE("GPL");
877
878 module_init(iblock_module_init);
879 module_exit(iblock_module_exit);
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