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Linux 4.19.133
[linux/fpc-iii.git] / drivers / target / target_core_iblock.c
blob5668d02de10b0d933fd9de5a93d57652846ff08c
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 ret = bioset_init(&ib_dev->ibd_bio_set, IBLOCK_BIO_POOL_SIZE, 0, BIOSET_NEED_BVECS);
98 if (ret) {
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_exit(&ib_dev->ibd_bio_set);
178 out:
179 return ret;
180 }
181
182 static void iblock_dev_call_rcu(struct rcu_head *p)
183 {
184 struct se_device *dev = container_of(p, struct se_device, rcu_head);
185 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
186
187 kfree(ib_dev);
188 }
189
190 static void iblock_free_device(struct se_device *dev)
191 {
192 call_rcu(&dev->rcu_head, iblock_dev_call_rcu);
193 }
194
195 static void iblock_destroy_device(struct se_device *dev)
196 {
197 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
198
199 if (ib_dev->ibd_bd != NULL)
200 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
201 bioset_exit(&ib_dev->ibd_bio_set);
202 }
203
204 static unsigned long long iblock_emulate_read_cap_with_block_size(
205 struct se_device *dev,
206 struct block_device *bd,
207 struct request_queue *q)
208 {
209 unsigned long long blocks_long = (div_u64(i_size_read(bd->bd_inode),
210 bdev_logical_block_size(bd)) - 1);
211 u32 block_size = bdev_logical_block_size(bd);
212
213 if (block_size == dev->dev_attrib.block_size)
214 return blocks_long;
215
216 switch (block_size) {
217 case 4096:
218 switch (dev->dev_attrib.block_size) {
219 case 2048:
220 blocks_long <<= 1;
221 break;
222 case 1024:
223 blocks_long <<= 2;
224 break;
225 case 512:
226 blocks_long <<= 3;
227 default:
228 break;
229 }
230 break;
231 case 2048:
232 switch (dev->dev_attrib.block_size) {
233 case 4096:
234 blocks_long >>= 1;
235 break;
236 case 1024:
237 blocks_long <<= 1;
238 break;
239 case 512:
240 blocks_long <<= 2;
241 break;
242 default:
243 break;
244 }
245 break;
246 case 1024:
247 switch (dev->dev_attrib.block_size) {
248 case 4096:
249 blocks_long >>= 2;
250 break;
251 case 2048:
252 blocks_long >>= 1;
253 break;
254 case 512:
255 blocks_long <<= 1;
256 break;
257 default:
258 break;
259 }
260 break;
261 case 512:
262 switch (dev->dev_attrib.block_size) {
263 case 4096:
264 blocks_long >>= 3;
265 break;
266 case 2048:
267 blocks_long >>= 2;
268 break;
269 case 1024:
270 blocks_long >>= 1;
271 break;
272 default:
273 break;
274 }
275 break;
276 default:
277 break;
278 }
279
280 return blocks_long;
281 }
282
283 static void iblock_complete_cmd(struct se_cmd *cmd)
284 {
285 struct iblock_req *ibr = cmd->priv;
286 u8 status;
287
288 if (!refcount_dec_and_test(&ibr->pending))
289 return;
290
291 if (atomic_read(&ibr->ib_bio_err_cnt))
292 status = SAM_STAT_CHECK_CONDITION;
293 else
294 status = SAM_STAT_GOOD;
295
296 target_complete_cmd(cmd, status);
297 kfree(ibr);
298 }
299
300 static void iblock_bio_done(struct bio *bio)
301 {
302 struct se_cmd *cmd = bio->bi_private;
303 struct iblock_req *ibr = cmd->priv;
304
305 if (bio->bi_status) {
306 pr_err("bio error: %p, err: %d\n", bio, bio->bi_status);
307 /*
308 * Bump the ib_bio_err_cnt and release bio.
309 */
310 atomic_inc(&ibr->ib_bio_err_cnt);
311 smp_mb__after_atomic();
312 }
313
314 bio_put(bio);
315
316 iblock_complete_cmd(cmd);
317 }
318
319 static struct bio *
320 iblock_get_bio(struct se_cmd *cmd, sector_t lba, u32 sg_num, int op,
321 int op_flags)
322 {
323 struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
324 struct bio *bio;
325
326 /*
327 * Only allocate as many vector entries as the bio code allows us to,
328 * we'll loop later on until we have handled the whole request.
329 */
330 if (sg_num > BIO_MAX_PAGES)
331 sg_num = BIO_MAX_PAGES;
332
333 bio = bio_alloc_bioset(GFP_NOIO, sg_num, &ib_dev->ibd_bio_set);
334 if (!bio) {
335 pr_err("Unable to allocate memory for bio\n");
336 return NULL;
337 }
338
339 bio_set_dev(bio, ib_dev->ibd_bd);
340 bio->bi_private = cmd;
341 bio->bi_end_io = &iblock_bio_done;
342 bio->bi_iter.bi_sector = lba;
343 bio_set_op_attrs(bio, op, op_flags);
344
345 return bio;
346 }
347
348 static void iblock_submit_bios(struct bio_list *list)
349 {
350 struct blk_plug plug;
351 struct bio *bio;
352
353 blk_start_plug(&plug);
354 while ((bio = bio_list_pop(list)))
355 submit_bio(bio);
356 blk_finish_plug(&plug);
357 }
358
359 static void iblock_end_io_flush(struct bio *bio)
360 {
361 struct se_cmd *cmd = bio->bi_private;
362
363 if (bio->bi_status)
364 pr_err("IBLOCK: cache flush failed: %d\n", bio->bi_status);
365
366 if (cmd) {
367 if (bio->bi_status)
368 target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
369 else
370 target_complete_cmd(cmd, SAM_STAT_GOOD);
371 }
372
373 bio_put(bio);
374 }
375
376 /*
377 * Implement SYCHRONIZE CACHE. Note that we can't handle lba ranges and must
378 * always flush the whole cache.
379 */
380 static sense_reason_t
381 iblock_execute_sync_cache(struct se_cmd *cmd)
382 {
383 struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
384 int immed = (cmd->t_task_cdb[1] & 0x2);
385 struct bio *bio;
386
387 /*
388 * If the Immediate bit is set, queue up the GOOD response
389 * for this SYNCHRONIZE_CACHE op.
390 */
391 if (immed)
392 target_complete_cmd(cmd, SAM_STAT_GOOD);
393
394 bio = bio_alloc(GFP_KERNEL, 0);
395 bio->bi_end_io = iblock_end_io_flush;
396 bio_set_dev(bio, ib_dev->ibd_bd);
397 bio->bi_opf = REQ_OP_WRITE | REQ_PREFLUSH;
398 if (!immed)
399 bio->bi_private = cmd;
400 submit_bio(bio);
401 return 0;
402 }
403
404 static sense_reason_t
405 iblock_execute_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
406 {
407 struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
408 struct se_device *dev = cmd->se_dev;
409 int ret;
410
411 ret = blkdev_issue_discard(bdev,
412 target_to_linux_sector(dev, lba),
413 target_to_linux_sector(dev, nolb),
414 GFP_KERNEL, 0);
415 if (ret < 0) {
416 pr_err("blkdev_issue_discard() failed: %d\n", ret);
417 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
418 }
419
420 return 0;
421 }
422
423 static sense_reason_t
424 iblock_execute_zero_out(struct block_device *bdev, struct se_cmd *cmd)
425 {
426 struct se_device *dev = cmd->se_dev;
427 struct scatterlist *sg = &cmd->t_data_sg[0];
428 unsigned char *buf, *not_zero;
429 int ret;
430
431 buf = kmap(sg_page(sg)) + sg->offset;
432 if (!buf)
433 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
434 /*
435 * Fall back to block_execute_write_same() slow-path if
436 * incoming WRITE_SAME payload does not contain zeros.
437 */
438 not_zero = memchr_inv(buf, 0x00, cmd->data_length);
439 kunmap(sg_page(sg));
440
441 if (not_zero)
442 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
443
444 ret = blkdev_issue_zeroout(bdev,
445 target_to_linux_sector(dev, cmd->t_task_lba),
446 target_to_linux_sector(dev,
447 sbc_get_write_same_sectors(cmd)),
448 GFP_KERNEL, BLKDEV_ZERO_NOUNMAP);
449 if (ret)
450 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
451
452 target_complete_cmd(cmd, GOOD);
453 return 0;
454 }
455
456 static sense_reason_t
457 iblock_execute_write_same(struct se_cmd *cmd)
458 {
459 struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
460 struct iblock_req *ibr;
461 struct scatterlist *sg;
462 struct bio *bio;
463 struct bio_list list;
464 struct se_device *dev = cmd->se_dev;
465 sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba);
466 sector_t sectors = target_to_linux_sector(dev,
467 sbc_get_write_same_sectors(cmd));
468
469 if (cmd->prot_op) {
470 pr_err("WRITE_SAME: Protection information with IBLOCK"
471 " backends not supported\n");
472 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
473 }
474 sg = &cmd->t_data_sg[0];
475
476 if (cmd->t_data_nents > 1 ||
477 sg->length != cmd->se_dev->dev_attrib.block_size) {
478 pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
479 " block_size: %u\n", cmd->t_data_nents, sg->length,
480 cmd->se_dev->dev_attrib.block_size);
481 return TCM_INVALID_CDB_FIELD;
482 }
483
484 if (bdev_write_zeroes_sectors(bdev)) {
485 if (!iblock_execute_zero_out(bdev, cmd))
486 return 0;
487 }
488
489 ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
490 if (!ibr)
491 goto fail;
492 cmd->priv = ibr;
493
494 bio = iblock_get_bio(cmd, block_lba, 1, REQ_OP_WRITE, 0);
495 if (!bio)
496 goto fail_free_ibr;
497
498 bio_list_init(&list);
499 bio_list_add(&list, bio);
500
501 refcount_set(&ibr->pending, 1);
502
503 while (sectors) {
504 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
505 != sg->length) {
506
507 bio = iblock_get_bio(cmd, block_lba, 1, REQ_OP_WRITE,
508 0);
509 if (!bio)
510 goto fail_put_bios;
511
512 refcount_inc(&ibr->pending);
513 bio_list_add(&list, bio);
514 }
515
516 /* Always in 512 byte units for Linux/Block */
517 block_lba += sg->length >> SECTOR_SHIFT;
518 sectors -= sg->length >> SECTOR_SHIFT;
519 }
520
521 iblock_submit_bios(&list);
522 return 0;
523
524 fail_put_bios:
525 while ((bio = bio_list_pop(&list)))
526 bio_put(bio);
527 fail_free_ibr:
528 kfree(ibr);
529 fail:
530 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
531 }
532
533 enum {
534 Opt_udev_path, Opt_readonly, Opt_force, Opt_err
535 };
536
537 static match_table_t tokens = {
538 {Opt_udev_path, "udev_path=%s"},
539 {Opt_readonly, "readonly=%d"},
540 {Opt_force, "force=%d"},
541 {Opt_err, NULL}
542 };
543
544 static ssize_t iblock_set_configfs_dev_params(struct se_device *dev,
545 const char *page, ssize_t count)
546 {
547 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
548 char *orig, *ptr, *arg_p, *opts;
549 substring_t args[MAX_OPT_ARGS];
550 int ret = 0, token;
551 unsigned long tmp_readonly;
552
553 opts = kstrdup(page, GFP_KERNEL);
554 if (!opts)
555 return -ENOMEM;
556
557 orig = opts;
558
559 while ((ptr = strsep(&opts, ",\n")) != NULL) {
560 if (!*ptr)
561 continue;
562
563 token = match_token(ptr, tokens, args);
564 switch (token) {
565 case Opt_udev_path:
566 if (ib_dev->ibd_bd) {
567 pr_err("Unable to set udev_path= while"
568 " ib_dev->ibd_bd exists\n");
569 ret = -EEXIST;
570 goto out;
571 }
572 if (match_strlcpy(ib_dev->ibd_udev_path, &args[0],
573 SE_UDEV_PATH_LEN) == 0) {
574 ret = -EINVAL;
575 break;
576 }
577 pr_debug("IBLOCK: Referencing UDEV path: %s\n",
578 ib_dev->ibd_udev_path);
579 ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH;
580 break;
581 case Opt_readonly:
582 arg_p = match_strdup(&args[0]);
583 if (!arg_p) {
584 ret = -ENOMEM;
585 break;
586 }
587 ret = kstrtoul(arg_p, 0, &tmp_readonly);
588 kfree(arg_p);
589 if (ret < 0) {
590 pr_err("kstrtoul() failed for"
591 " readonly=\n");
592 goto out;
593 }
594 ib_dev->ibd_readonly = tmp_readonly;
595 pr_debug("IBLOCK: readonly: %d\n", ib_dev->ibd_readonly);
596 break;
597 case Opt_force:
598 break;
599 default:
600 break;
601 }
602 }
603
604 out:
605 kfree(orig);
606 return (!ret) ? count : ret;
607 }
608
609 static ssize_t iblock_show_configfs_dev_params(struct se_device *dev, char *b)
610 {
611 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
612 struct block_device *bd = ib_dev->ibd_bd;
613 char buf[BDEVNAME_SIZE];
614 ssize_t bl = 0;
615
616 if (bd)
617 bl += sprintf(b + bl, "iBlock device: %s",
618 bdevname(bd, buf));
619 if (ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)
620 bl += sprintf(b + bl, " UDEV PATH: %s",
621 ib_dev->ibd_udev_path);
622 bl += sprintf(b + bl, " readonly: %d\n", ib_dev->ibd_readonly);
623
624 bl += sprintf(b + bl, " ");
625 if (bd) {
626 bl += sprintf(b + bl, "Major: %d Minor: %d %s\n",
627 MAJOR(bd->bd_dev), MINOR(bd->bd_dev), (!bd->bd_contains) ?
628 "" : (bd->bd_holder == ib_dev) ?
629 "CLAIMED: IBLOCK" : "CLAIMED: OS");
630 } else {
631 bl += sprintf(b + bl, "Major: 0 Minor: 0\n");
632 }
633
634 return bl;
635 }
636
637 static int
638 iblock_alloc_bip(struct se_cmd *cmd, struct bio *bio)
639 {
640 struct se_device *dev = cmd->se_dev;
641 struct blk_integrity *bi;
642 struct bio_integrity_payload *bip;
643 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
644 struct scatterlist *sg;
645 int i, rc;
646
647 bi = bdev_get_integrity(ib_dev->ibd_bd);
648 if (!bi) {
649 pr_err("Unable to locate bio_integrity\n");
650 return -ENODEV;
651 }
652
653 bip = bio_integrity_alloc(bio, GFP_NOIO, cmd->t_prot_nents);
654 if (IS_ERR(bip)) {
655 pr_err("Unable to allocate bio_integrity_payload\n");
656 return PTR_ERR(bip);
657 }
658
659 bip->bip_iter.bi_size = (cmd->data_length / dev->dev_attrib.block_size) *
660 dev->prot_length;
661 bip->bip_iter.bi_sector = bio->bi_iter.bi_sector;
662
663 pr_debug("IBLOCK BIP Size: %u Sector: %llu\n", bip->bip_iter.bi_size,
664 (unsigned long long)bip->bip_iter.bi_sector);
665
666 for_each_sg(cmd->t_prot_sg, sg, cmd->t_prot_nents, i) {
667
668 rc = bio_integrity_add_page(bio, sg_page(sg), sg->length,
669 sg->offset);
670 if (rc != sg->length) {
671 pr_err("bio_integrity_add_page() failed; %d\n", rc);
672 return -ENOMEM;
673 }
674
675 pr_debug("Added bio integrity page: %p length: %d offset; %d\n",
676 sg_page(sg), sg->length, sg->offset);
677 }
678
679 return 0;
680 }
681
682 static sense_reason_t
683 iblock_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
684 enum dma_data_direction data_direction)
685 {
686 struct se_device *dev = cmd->se_dev;
687 sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba);
688 struct iblock_req *ibr;
689 struct bio *bio, *bio_start;
690 struct bio_list list;
691 struct scatterlist *sg;
692 u32 sg_num = sgl_nents;
693 unsigned bio_cnt;
694 int i, op, op_flags = 0;
695
696 if (data_direction == DMA_TO_DEVICE) {
697 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
698 struct request_queue *q = bdev_get_queue(ib_dev->ibd_bd);
699 /*
700 * Force writethrough using REQ_FUA if a volatile write cache
701 * is not enabled, or if initiator set the Force Unit Access bit.
702 */
703 op = REQ_OP_WRITE;
704 if (test_bit(QUEUE_FLAG_FUA, &q->queue_flags)) {
705 if (cmd->se_cmd_flags & SCF_FUA)
706 op_flags = REQ_FUA;
707 else if (!test_bit(QUEUE_FLAG_WC, &q->queue_flags))
708 op_flags = REQ_FUA;
709 }
710 } else {
711 op = REQ_OP_READ;
712 }
713
714 ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
715 if (!ibr)
716 goto fail;
717 cmd->priv = ibr;
718
719 if (!sgl_nents) {
720 refcount_set(&ibr->pending, 1);
721 iblock_complete_cmd(cmd);
722 return 0;
723 }
724
725 bio = iblock_get_bio(cmd, block_lba, sgl_nents, op, op_flags);
726 if (!bio)
727 goto fail_free_ibr;
728
729 bio_start = bio;
730 bio_list_init(&list);
731 bio_list_add(&list, bio);
732
733 refcount_set(&ibr->pending, 2);
734 bio_cnt = 1;
735
736 for_each_sg(sgl, sg, sgl_nents, i) {
737 /*
738 * XXX: if the length the device accepts is shorter than the
739 * length of the S/G list entry this will cause and
740 * endless loop. Better hope no driver uses huge pages.
741 */
742 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
743 != sg->length) {
744 if (bio_cnt >= IBLOCK_MAX_BIO_PER_TASK) {
745 iblock_submit_bios(&list);
746 bio_cnt = 0;
747 }
748
749 bio = iblock_get_bio(cmd, block_lba, sg_num, op,
750 op_flags);
751 if (!bio)
752 goto fail_put_bios;
753
754 refcount_inc(&ibr->pending);
755 bio_list_add(&list, bio);
756 bio_cnt++;
757 }
758
759 /* Always in 512 byte units for Linux/Block */
760 block_lba += sg->length >> SECTOR_SHIFT;
761 sg_num--;
762 }
763
764 if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
765 int rc = iblock_alloc_bip(cmd, bio_start);
766 if (rc)
767 goto fail_put_bios;
768 }
769
770 iblock_submit_bios(&list);
771 iblock_complete_cmd(cmd);
772 return 0;
773
774 fail_put_bios:
775 while ((bio = bio_list_pop(&list)))
776 bio_put(bio);
777 fail_free_ibr:
778 kfree(ibr);
779 fail:
780 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
781 }
782
783 static sector_t iblock_get_blocks(struct se_device *dev)
784 {
785 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
786 struct block_device *bd = ib_dev->ibd_bd;
787 struct request_queue *q = bdev_get_queue(bd);
788
789 return iblock_emulate_read_cap_with_block_size(dev, bd, q);
790 }
791
792 static sector_t iblock_get_alignment_offset_lbas(struct se_device *dev)
793 {
794 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
795 struct block_device *bd = ib_dev->ibd_bd;
796 int ret;
797
798 ret = bdev_alignment_offset(bd);
799 if (ret == -1)
800 return 0;
801
802 /* convert offset-bytes to offset-lbas */
803 return ret / bdev_logical_block_size(bd);
804 }
805
806 static unsigned int iblock_get_lbppbe(struct se_device *dev)
807 {
808 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
809 struct block_device *bd = ib_dev->ibd_bd;
810 int logs_per_phys = bdev_physical_block_size(bd) / bdev_logical_block_size(bd);
811
812 return ilog2(logs_per_phys);
813 }
814
815 static unsigned int iblock_get_io_min(struct se_device *dev)
816 {
817 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
818 struct block_device *bd = ib_dev->ibd_bd;
819
820 return bdev_io_min(bd);
821 }
822
823 static unsigned int iblock_get_io_opt(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_opt(bd);
829 }
830
831 static struct sbc_ops iblock_sbc_ops = {
832 .execute_rw = iblock_execute_rw,
833 .execute_sync_cache = iblock_execute_sync_cache,
834 .execute_write_same = iblock_execute_write_same,
835 .execute_unmap = iblock_execute_unmap,
836 };
837
838 static sense_reason_t
839 iblock_parse_cdb(struct se_cmd *cmd)
840 {
841 return sbc_parse_cdb(cmd, &iblock_sbc_ops);
842 }
843
844 static bool iblock_get_write_cache(struct se_device *dev)
845 {
846 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
847 struct block_device *bd = ib_dev->ibd_bd;
848 struct request_queue *q = bdev_get_queue(bd);
849
850 return test_bit(QUEUE_FLAG_WC, &q->queue_flags);
851 }
852
853 static const struct target_backend_ops iblock_ops = {
854 .name = "iblock",
855 .inquiry_prod = "IBLOCK",
856 .inquiry_rev = IBLOCK_VERSION,
857 .owner = THIS_MODULE,
858 .attach_hba = iblock_attach_hba,
859 .detach_hba = iblock_detach_hba,
860 .alloc_device = iblock_alloc_device,
861 .configure_device = iblock_configure_device,
862 .destroy_device = iblock_destroy_device,
863 .free_device = iblock_free_device,
864 .parse_cdb = iblock_parse_cdb,
865 .set_configfs_dev_params = iblock_set_configfs_dev_params,
866 .show_configfs_dev_params = iblock_show_configfs_dev_params,
867 .get_device_type = sbc_get_device_type,
868 .get_blocks = iblock_get_blocks,
869 .get_alignment_offset_lbas = iblock_get_alignment_offset_lbas,
870 .get_lbppbe = iblock_get_lbppbe,
871 .get_io_min = iblock_get_io_min,
872 .get_io_opt = iblock_get_io_opt,
873 .get_write_cache = iblock_get_write_cache,
874 .tb_dev_attrib_attrs = sbc_attrib_attrs,
875 };
876
877 static int __init iblock_module_init(void)
878 {
879 return transport_backend_register(&iblock_ops);
880 }
881
882 static void __exit iblock_module_exit(void)
883 {
884 target_backend_unregister(&iblock_ops);
885 }
886
887 MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin");
888 MODULE_AUTHOR("nab@Linux-iSCSI.org");
889 MODULE_LICENSE("GPL");
890
891 module_init(iblock_module_init);
892 module_exit(iblock_module_exit);
Linux with added FPC-III support