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[mirror_ubuntu-artful-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 unsigned int max_write_zeroes_sectors;
90 int ret = -ENOMEM;
91
92 if (!(ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)) {
93 pr_err("Missing udev_path= parameters for IBLOCK\n");
94 return -EINVAL;
95 }
96
97 ib_dev->ibd_bio_set = bioset_create(IBLOCK_BIO_POOL_SIZE, 0, BIOSET_NEED_BVECS);
98 if (!ib_dev->ibd_bio_set) {
99 pr_err("IBLOCK: Unable to create bioset\n");
100 goto out;
101 }
102
103 pr_debug( "IBLOCK: Claiming struct block_device: %s\n",
104 ib_dev->ibd_udev_path);
105
106 mode = FMODE_READ|FMODE_EXCL;
107 if (!ib_dev->ibd_readonly)
108 mode |= FMODE_WRITE;
109 else
110 dev->dev_flags |= DF_READ_ONLY;
111
112 bd = blkdev_get_by_path(ib_dev->ibd_udev_path, mode, ib_dev);
113 if (IS_ERR(bd)) {
114 ret = PTR_ERR(bd);
115 goto out_free_bioset;
116 }
117 ib_dev->ibd_bd = bd;
118
119 q = bdev_get_queue(bd);
120
121 dev->dev_attrib.hw_block_size = bdev_logical_block_size(bd);
122 dev->dev_attrib.hw_max_sectors = queue_max_hw_sectors(q);
123 dev->dev_attrib.hw_queue_depth = q->nr_requests;
124
125 if (target_configure_unmap_from_queue(&dev->dev_attrib, q))
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 max_write_zeroes_sectors = bdev_write_zeroes_sectors(bd);
134 if (max_write_zeroes_sectors)
135 dev->dev_attrib.max_write_same_len = max_write_zeroes_sectors;
136 else
137 dev->dev_attrib.max_write_same_len = 0xFFFF;
138
139 if (blk_queue_nonrot(q))
140 dev->dev_attrib.is_nonrot = 1;
141
142 bi = bdev_get_integrity(bd);
143 if (bi) {
144 struct bio_set *bs = ib_dev->ibd_bio_set;
145
146 if (!strcmp(bi->profile->name, "T10-DIF-TYPE3-IP") ||
147 !strcmp(bi->profile->name, "T10-DIF-TYPE1-IP")) {
148 pr_err("IBLOCK export of blk_integrity: %s not"
149 " supported\n", bi->profile->name);
150 ret = -ENOSYS;
151 goto out_blkdev_put;
152 }
153
154 if (!strcmp(bi->profile->name, "T10-DIF-TYPE3-CRC")) {
155 dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE3_PROT;
156 } else if (!strcmp(bi->profile->name, "T10-DIF-TYPE1-CRC")) {
157 dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE1_PROT;
158 }
159
160 if (dev->dev_attrib.pi_prot_type) {
161 if (bioset_integrity_create(bs, IBLOCK_BIO_POOL_SIZE) < 0) {
162 pr_err("Unable to allocate bioset for PI\n");
163 ret = -ENOMEM;
164 goto out_blkdev_put;
165 }
166 pr_debug("IBLOCK setup BIP bs->bio_integrity_pool: %p\n",
167 bs->bio_integrity_pool);
168 }
169 dev->dev_attrib.hw_pi_prot_type = dev->dev_attrib.pi_prot_type;
170 }
171
172 return 0;
173
174 out_blkdev_put:
175 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
176 out_free_bioset:
177 bioset_free(ib_dev->ibd_bio_set);
178 ib_dev->ibd_bio_set = NULL;
179 out:
180 return ret;
181 }
182
183 static void iblock_dev_call_rcu(struct rcu_head *p)
184 {
185 struct se_device *dev = container_of(p, struct se_device, rcu_head);
186 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
187
188 kfree(ib_dev);
189 }
190
191 static void iblock_free_device(struct se_device *dev)
192 {
193 call_rcu(&dev->rcu_head, iblock_dev_call_rcu);
194 }
195
196 static void iblock_destroy_device(struct se_device *dev)
197 {
198 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
199
200 if (ib_dev->ibd_bd != NULL)
201 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
202 if (ib_dev->ibd_bio_set != NULL)
203 bioset_free(ib_dev->ibd_bio_set);
204 }
205
206 static unsigned long long iblock_emulate_read_cap_with_block_size(
207 struct se_device *dev,
208 struct block_device *bd,
209 struct request_queue *q)
210 {
211 unsigned long long blocks_long = (div_u64(i_size_read(bd->bd_inode),
212 bdev_logical_block_size(bd)) - 1);
213 u32 block_size = bdev_logical_block_size(bd);
214
215 if (block_size == dev->dev_attrib.block_size)
216 return blocks_long;
217
218 switch (block_size) {
219 case 4096:
220 switch (dev->dev_attrib.block_size) {
221 case 2048:
222 blocks_long <<= 1;
223 break;
224 case 1024:
225 blocks_long <<= 2;
226 break;
227 case 512:
228 blocks_long <<= 3;
229 default:
230 break;
231 }
232 break;
233 case 2048:
234 switch (dev->dev_attrib.block_size) {
235 case 4096:
236 blocks_long >>= 1;
237 break;
238 case 1024:
239 blocks_long <<= 1;
240 break;
241 case 512:
242 blocks_long <<= 2;
243 break;
244 default:
245 break;
246 }
247 break;
248 case 1024:
249 switch (dev->dev_attrib.block_size) {
250 case 4096:
251 blocks_long >>= 2;
252 break;
253 case 2048:
254 blocks_long >>= 1;
255 break;
256 case 512:
257 blocks_long <<= 1;
258 break;
259 default:
260 break;
261 }
262 break;
263 case 512:
264 switch (dev->dev_attrib.block_size) {
265 case 4096:
266 blocks_long >>= 3;
267 break;
268 case 2048:
269 blocks_long >>= 2;
270 break;
271 case 1024:
272 blocks_long >>= 1;
273 break;
274 default:
275 break;
276 }
277 break;
278 default:
279 break;
280 }
281
282 return blocks_long;
283 }
284
285 static void iblock_complete_cmd(struct se_cmd *cmd)
286 {
287 struct iblock_req *ibr = cmd->priv;
288 u8 status;
289
290 if (!refcount_dec_and_test(&ibr->pending))
291 return;
292
293 if (atomic_read(&ibr->ib_bio_err_cnt))
294 status = SAM_STAT_CHECK_CONDITION;
295 else
296 status = SAM_STAT_GOOD;
297
298 target_complete_cmd(cmd, status);
299 kfree(ibr);
300 }
301
302 static void iblock_bio_done(struct bio *bio)
303 {
304 struct se_cmd *cmd = bio->bi_private;
305 struct iblock_req *ibr = cmd->priv;
306
307 if (bio->bi_status) {
308 pr_err("bio error: %p, err: %d\n", bio, bio->bi_status);
309 /*
310 * Bump the ib_bio_err_cnt and release bio.
311 */
312 atomic_inc(&ibr->ib_bio_err_cnt);
313 smp_mb__after_atomic();
314 }
315
316 bio_put(bio);
317
318 iblock_complete_cmd(cmd);
319 }
320
321 static struct bio *
322 iblock_get_bio(struct se_cmd *cmd, sector_t lba, u32 sg_num, int op,
323 int op_flags)
324 {
325 struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
326 struct bio *bio;
327
328 /*
329 * Only allocate as many vector entries as the bio code allows us to,
330 * we'll loop later on until we have handled the whole request.
331 */
332 if (sg_num > BIO_MAX_PAGES)
333 sg_num = BIO_MAX_PAGES;
334
335 bio = bio_alloc_bioset(GFP_NOIO, sg_num, ib_dev->ibd_bio_set);
336 if (!bio) {
337 pr_err("Unable to allocate memory for bio\n");
338 return NULL;
339 }
340
341 bio->bi_bdev = ib_dev->ibd_bd;
342 bio->bi_private = cmd;
343 bio->bi_end_io = &iblock_bio_done;
344 bio->bi_iter.bi_sector = lba;
345 bio_set_op_attrs(bio, op, op_flags);
346
347 return bio;
348 }
349
350 static void iblock_submit_bios(struct bio_list *list)
351 {
352 struct blk_plug plug;
353 struct bio *bio;
354
355 blk_start_plug(&plug);
356 while ((bio = bio_list_pop(list)))
357 submit_bio(bio);
358 blk_finish_plug(&plug);
359 }
360
361 static void iblock_end_io_flush(struct bio *bio)
362 {
363 struct se_cmd *cmd = bio->bi_private;
364
365 if (bio->bi_status)
366 pr_err("IBLOCK: cache flush failed: %d\n", bio->bi_status);
367
368 if (cmd) {
369 if (bio->bi_status)
370 target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
371 else
372 target_complete_cmd(cmd, SAM_STAT_GOOD);
373 }
374
375 bio_put(bio);
376 }
377
378 /*
379 * Implement SYCHRONIZE CACHE. Note that we can't handle lba ranges and must
380 * always flush the whole cache.
381 */
382 static sense_reason_t
383 iblock_execute_sync_cache(struct se_cmd *cmd)
384 {
385 struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
386 int immed = (cmd->t_task_cdb[1] & 0x2);
387 struct bio *bio;
388
389 /*
390 * If the Immediate bit is set, queue up the GOOD response
391 * for this SYNCHRONIZE_CACHE op.
392 */
393 if (immed)
394 target_complete_cmd(cmd, SAM_STAT_GOOD);
395
396 bio = bio_alloc(GFP_KERNEL, 0);
397 bio->bi_end_io = iblock_end_io_flush;
398 bio->bi_bdev = ib_dev->ibd_bd;
399 bio->bi_opf = REQ_OP_WRITE | REQ_PREFLUSH;
400 if (!immed)
401 bio->bi_private = cmd;
402 submit_bio(bio);
403 return 0;
404 }
405
406 static sense_reason_t
407 iblock_execute_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
408 {
409 struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
410 struct se_device *dev = cmd->se_dev;
411 int ret;
412
413 ret = blkdev_issue_discard(bdev,
414 target_to_linux_sector(dev, lba),
415 target_to_linux_sector(dev, nolb),
416 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_zero_out(struct block_device *bdev, struct se_cmd *cmd)
427 {
428 struct se_device *dev = cmd->se_dev;
429 struct scatterlist *sg = &cmd->t_data_sg[0];
430 unsigned char *buf, zero = 0x00, *p = &zero;
431 int rc, ret;
432
433 buf = kmap(sg_page(sg)) + sg->offset;
434 if (!buf)
435 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
436 /*
437 * Fall back to block_execute_write_same() slow-path if
438 * incoming WRITE_SAME payload does not contain zeros.
439 */
440 rc = memcmp(buf, p, cmd->data_length);
441 kunmap(sg_page(sg));
442
443 if (rc)
444 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
445
446 ret = blkdev_issue_zeroout(bdev,
447 target_to_linux_sector(dev, cmd->t_task_lba),
448 target_to_linux_sector(dev,
449 sbc_get_write_same_sectors(cmd)),
450 GFP_KERNEL, false);
451 if (ret)
452 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
453
454 target_complete_cmd(cmd, GOOD);
455 return 0;
456 }
457
458 static sense_reason_t
459 iblock_execute_write_same(struct se_cmd *cmd)
460 {
461 struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
462 struct iblock_req *ibr;
463 struct scatterlist *sg;
464 struct bio *bio;
465 struct bio_list list;
466 struct se_device *dev = cmd->se_dev;
467 sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba);
468 sector_t sectors = target_to_linux_sector(dev,
469 sbc_get_write_same_sectors(cmd));
470
471 if (cmd->prot_op) {
472 pr_err("WRITE_SAME: Protection information with IBLOCK"
473 " backends not supported\n");
474 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
475 }
476 sg = &cmd->t_data_sg[0];
477
478 if (cmd->t_data_nents > 1 ||
479 sg->length != cmd->se_dev->dev_attrib.block_size) {
480 pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
481 " block_size: %u\n", cmd->t_data_nents, sg->length,
482 cmd->se_dev->dev_attrib.block_size);
483 return TCM_INVALID_CDB_FIELD;
484 }
485
486 if (bdev_write_zeroes_sectors(bdev)) {
487 if (!iblock_execute_zero_out(bdev, cmd))
488 return 0;
489 }
490
491 ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
492 if (!ibr)
493 goto fail;
494 cmd->priv = ibr;
495
496 bio = iblock_get_bio(cmd, block_lba, 1, REQ_OP_WRITE, 0);
497 if (!bio)
498 goto fail_free_ibr;
499
500 bio_list_init(&list);
501 bio_list_add(&list, bio);
502
503 refcount_set(&ibr->pending, 1);
504
505 while (sectors) {
506 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
507 != sg->length) {
508
509 bio = iblock_get_bio(cmd, block_lba, 1, REQ_OP_WRITE,
510 0);
511 if (!bio)
512 goto fail_put_bios;
513
514 refcount_inc(&ibr->pending);
515 bio_list_add(&list, bio);
516 }
517
518 /* Always in 512 byte units for Linux/Block */
519 block_lba += sg->length >> IBLOCK_LBA_SHIFT;
520 sectors -= 1;
521 }
522
523 iblock_submit_bios(&list);
524 return 0;
525
526 fail_put_bios:
527 while ((bio = bio_list_pop(&list)))
528 bio_put(bio);
529 fail_free_ibr:
530 kfree(ibr);
531 fail:
532 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
533 }
534
535 enum {
536 Opt_udev_path, Opt_readonly, Opt_force, Opt_err
537 };
538
539 static match_table_t tokens = {
540 {Opt_udev_path, "udev_path=%s"},
541 {Opt_readonly, "readonly=%d"},
542 {Opt_force, "force=%d"},
543 {Opt_err, NULL}
544 };
545
546 static ssize_t iblock_set_configfs_dev_params(struct se_device *dev,
547 const char *page, ssize_t count)
548 {
549 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
550 char *orig, *ptr, *arg_p, *opts;
551 substring_t args[MAX_OPT_ARGS];
552 int ret = 0, token;
553 unsigned long tmp_readonly;
554
555 opts = kstrdup(page, GFP_KERNEL);
556 if (!opts)
557 return -ENOMEM;
558
559 orig = opts;
560
561 while ((ptr = strsep(&opts, ",\n")) != NULL) {
562 if (!*ptr)
563 continue;
564
565 token = match_token(ptr, tokens, args);
566 switch (token) {
567 case Opt_udev_path:
568 if (ib_dev->ibd_bd) {
569 pr_err("Unable to set udev_path= while"
570 " ib_dev->ibd_bd exists\n");
571 ret = -EEXIST;
572 goto out;
573 }
574 if (match_strlcpy(ib_dev->ibd_udev_path, &args[0],
575 SE_UDEV_PATH_LEN) == 0) {
576 ret = -EINVAL;
577 break;
578 }
579 pr_debug("IBLOCK: Referencing UDEV path: %s\n",
580 ib_dev->ibd_udev_path);
581 ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH;
582 break;
583 case Opt_readonly:
584 arg_p = match_strdup(&args[0]);
585 if (!arg_p) {
586 ret = -ENOMEM;
587 break;
588 }
589 ret = kstrtoul(arg_p, 0, &tmp_readonly);
590 kfree(arg_p);
591 if (ret < 0) {
592 pr_err("kstrtoul() failed for"
593 " readonly=\n");
594 goto out;
595 }
596 ib_dev->ibd_readonly = tmp_readonly;
597 pr_debug("IBLOCK: readonly: %d\n", ib_dev->ibd_readonly);
598 break;
599 case Opt_force:
600 break;
601 default:
602 break;
603 }
604 }
605
606 out:
607 kfree(orig);
608 return (!ret) ? count : ret;
609 }
610
611 static ssize_t iblock_show_configfs_dev_params(struct se_device *dev, char *b)
612 {
613 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
614 struct block_device *bd = ib_dev->ibd_bd;
615 char buf[BDEVNAME_SIZE];
616 ssize_t bl = 0;
617
618 if (bd)
619 bl += sprintf(b + bl, "iBlock device: %s",
620 bdevname(bd, buf));
621 if (ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)
622 bl += sprintf(b + bl, " UDEV PATH: %s",
623 ib_dev->ibd_udev_path);
624 bl += sprintf(b + bl, " readonly: %d\n", ib_dev->ibd_readonly);
625
626 bl += sprintf(b + bl, " ");
627 if (bd) {
628 bl += sprintf(b + bl, "Major: %d Minor: %d %s\n",
629 MAJOR(bd->bd_dev), MINOR(bd->bd_dev), (!bd->bd_contains) ?
630 "" : (bd->bd_holder == ib_dev) ?
631 "CLAIMED: IBLOCK" : "CLAIMED: OS");
632 } else {
633 bl += sprintf(b + bl, "Major: 0 Minor: 0\n");
634 }
635
636 return bl;
637 }
638
639 static int
640 iblock_alloc_bip(struct se_cmd *cmd, struct bio *bio)
641 {
642 struct se_device *dev = cmd->se_dev;
643 struct blk_integrity *bi;
644 struct bio_integrity_payload *bip;
645 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
646 struct scatterlist *sg;
647 int i, rc;
648
649 bi = bdev_get_integrity(ib_dev->ibd_bd);
650 if (!bi) {
651 pr_err("Unable to locate bio_integrity\n");
652 return -ENODEV;
653 }
654
655 bip = bio_integrity_alloc(bio, GFP_NOIO, cmd->t_prot_nents);
656 if (IS_ERR(bip)) {
657 pr_err("Unable to allocate bio_integrity_payload\n");
658 return PTR_ERR(bip);
659 }
660
661 bip->bip_iter.bi_size = (cmd->data_length / dev->dev_attrib.block_size) *
662 dev->prot_length;
663 bip->bip_iter.bi_sector = bio->bi_iter.bi_sector;
664
665 pr_debug("IBLOCK BIP Size: %u Sector: %llu\n", bip->bip_iter.bi_size,
666 (unsigned long long)bip->bip_iter.bi_sector);
667
668 for_each_sg(cmd->t_prot_sg, sg, cmd->t_prot_nents, i) {
669
670 rc = bio_integrity_add_page(bio, sg_page(sg), sg->length,
671 sg->offset);
672 if (rc != sg->length) {
673 pr_err("bio_integrity_add_page() failed; %d\n", rc);
674 return -ENOMEM;
675 }
676
677 pr_debug("Added bio integrity page: %p length: %d offset; %d\n",
678 sg_page(sg), sg->length, sg->offset);
679 }
680
681 return 0;
682 }
683
684 static sense_reason_t
685 iblock_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
686 enum dma_data_direction data_direction)
687 {
688 struct se_device *dev = cmd->se_dev;
689 sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba);
690 struct iblock_req *ibr;
691 struct bio *bio, *bio_start;
692 struct bio_list list;
693 struct scatterlist *sg;
694 u32 sg_num = sgl_nents;
695 unsigned bio_cnt;
696 int i, op, op_flags = 0;
697
698 if (data_direction == DMA_TO_DEVICE) {
699 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
700 struct request_queue *q = bdev_get_queue(ib_dev->ibd_bd);
701 /*
702 * Force writethrough using REQ_FUA if a volatile write cache
703 * is not enabled, or if initiator set the Force Unit Access bit.
704 */
705 op = REQ_OP_WRITE;
706 if (test_bit(QUEUE_FLAG_FUA, &q->queue_flags)) {
707 if (cmd->se_cmd_flags & SCF_FUA)
708 op_flags = REQ_FUA;
709 else if (!test_bit(QUEUE_FLAG_WC, &q->queue_flags))
710 op_flags = REQ_FUA;
711 }
712 } else {
713 op = REQ_OP_READ;
714 }
715
716 ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
717 if (!ibr)
718 goto fail;
719 cmd->priv = ibr;
720
721 if (!sgl_nents) {
722 refcount_set(&ibr->pending, 1);
723 iblock_complete_cmd(cmd);
724 return 0;
725 }
726
727 bio = iblock_get_bio(cmd, block_lba, sgl_nents, op, op_flags);
728 if (!bio)
729 goto fail_free_ibr;
730
731 bio_start = bio;
732 bio_list_init(&list);
733 bio_list_add(&list, bio);
734
735 refcount_set(&ibr->pending, 2);
736 bio_cnt = 1;
737
738 for_each_sg(sgl, sg, sgl_nents, i) {
739 /*
740 * XXX: if the length the device accepts is shorter than the
741 * length of the S/G list entry this will cause and
742 * endless loop. Better hope no driver uses huge pages.
743 */
744 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
745 != sg->length) {
746 if (bio_cnt >= IBLOCK_MAX_BIO_PER_TASK) {
747 iblock_submit_bios(&list);
748 bio_cnt = 0;
749 }
750
751 bio = iblock_get_bio(cmd, block_lba, sg_num, op,
752 op_flags);
753 if (!bio)
754 goto fail_put_bios;
755
756 refcount_inc(&ibr->pending);
757 bio_list_add(&list, bio);
758 bio_cnt++;
759 }
760
761 /* Always in 512 byte units for Linux/Block */
762 block_lba += sg->length >> IBLOCK_LBA_SHIFT;
763 sg_num--;
764 }
765
766 if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
767 int rc = iblock_alloc_bip(cmd, bio_start);
768 if (rc)
769 goto fail_put_bios;
770 }
771
772 iblock_submit_bios(&list);
773 iblock_complete_cmd(cmd);
774 return 0;
775
776 fail_put_bios:
777 while ((bio = bio_list_pop(&list)))
778 bio_put(bio);
779 fail_free_ibr:
780 kfree(ibr);
781 fail:
782 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
783 }
784
785 static sector_t iblock_get_blocks(struct se_device *dev)
786 {
787 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
788 struct block_device *bd = ib_dev->ibd_bd;
789 struct request_queue *q = bdev_get_queue(bd);
790
791 return iblock_emulate_read_cap_with_block_size(dev, bd, q);
792 }
793
794 static sector_t iblock_get_alignment_offset_lbas(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 ret;
799
800 ret = bdev_alignment_offset(bd);
801 if (ret == -1)
802 return 0;
803
804 /* convert offset-bytes to offset-lbas */
805 return ret / bdev_logical_block_size(bd);
806 }
807
808 static unsigned int iblock_get_lbppbe(struct se_device *dev)
809 {
810 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
811 struct block_device *bd = ib_dev->ibd_bd;
812 int logs_per_phys = bdev_physical_block_size(bd) / bdev_logical_block_size(bd);
813
814 return ilog2(logs_per_phys);
815 }
816
817 static unsigned int iblock_get_io_min(struct se_device *dev)
818 {
819 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
820 struct block_device *bd = ib_dev->ibd_bd;
821
822 return bdev_io_min(bd);
823 }
824
825 static unsigned int iblock_get_io_opt(struct se_device *dev)
826 {
827 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
828 struct block_device *bd = ib_dev->ibd_bd;
829
830 return bdev_io_opt(bd);
831 }
832
833 static struct sbc_ops iblock_sbc_ops = {
834 .execute_rw = iblock_execute_rw,
835 .execute_sync_cache = iblock_execute_sync_cache,
836 .execute_write_same = iblock_execute_write_same,
837 .execute_unmap = iblock_execute_unmap,
838 };
839
840 static sense_reason_t
841 iblock_parse_cdb(struct se_cmd *cmd)
842 {
843 return sbc_parse_cdb(cmd, &iblock_sbc_ops);
844 }
845
846 static bool iblock_get_write_cache(struct se_device *dev)
847 {
848 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
849 struct block_device *bd = ib_dev->ibd_bd;
850 struct request_queue *q = bdev_get_queue(bd);
851
852 return test_bit(QUEUE_FLAG_WC, &q->queue_flags);
853 }
854
855 static const struct target_backend_ops iblock_ops = {
856 .name = "iblock",
857 .inquiry_prod = "IBLOCK",
858 .inquiry_rev = IBLOCK_VERSION,
859 .owner = THIS_MODULE,
860 .attach_hba = iblock_attach_hba,
861 .detach_hba = iblock_detach_hba,
862 .alloc_device = iblock_alloc_device,
863 .configure_device = iblock_configure_device,
864 .destroy_device = iblock_destroy_device,
865 .free_device = iblock_free_device,
866 .parse_cdb = iblock_parse_cdb,
867 .set_configfs_dev_params = iblock_set_configfs_dev_params,
868 .show_configfs_dev_params = iblock_show_configfs_dev_params,
869 .get_device_type = sbc_get_device_type,
870 .get_blocks = iblock_get_blocks,
871 .get_alignment_offset_lbas = iblock_get_alignment_offset_lbas,
872 .get_lbppbe = iblock_get_lbppbe,
873 .get_io_min = iblock_get_io_min,
874 .get_io_opt = iblock_get_io_opt,
875 .get_write_cache = iblock_get_write_cache,
876 .tb_dev_attrib_attrs = sbc_attrib_attrs,
877 };
878
879 static int __init iblock_module_init(void)
880 {
881 return transport_backend_register(&iblock_ops);
882 }
883
884 static void __exit iblock_module_exit(void)
885 {
886 target_backend_unregister(&iblock_ops);
887 }
888
889 MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin");
890 MODULE_AUTHOR("nab@Linux-iSCSI.org");
891 MODULE_LICENSE("GPL");
892
893 module_init(iblock_module_init);
894 module_exit(iblock_module_exit);
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