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LiteX: driver for MMCM
[linux/fpc-iii.git] / drivers / target / target_core_iblock.c
blob8ed93fd205c7e83c3bc7eba3bf8ce9ef85890112
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*******************************************************************************
3 * Filename: target_core_iblock.c
4 *
5 * This file contains the Storage Engine <-> Linux BlockIO transport
6 * specific functions.
7 *
8 * (c) Copyright 2003-2013 Datera, Inc.
9 *
10 * Nicholas A. Bellinger <nab@kernel.org>
11 *
12 ******************************************************************************/
13
14 #include <linux/string.h>
15 #include <linux/parser.h>
16 #include <linux/timer.h>
17 #include <linux/fs.h>
18 #include <linux/blkdev.h>
19 #include <linux/slab.h>
20 #include <linux/spinlock.h>
21 #include <linux/bio.h>
22 #include <linux/genhd.h>
23 #include <linux/file.h>
24 #include <linux/module.h>
25 #include <scsi/scsi_proto.h>
26 #include <asm/unaligned.h>
27
28 #include <target/target_core_base.h>
29 #include <target/target_core_backend.h>
30
31 #include "target_core_iblock.h"
32
33 #define IBLOCK_MAX_BIO_PER_TASK 32 /* max # of bios to submit at a time */
34 #define IBLOCK_BIO_POOL_SIZE 128
35
36 static inline struct iblock_dev *IBLOCK_DEV(struct se_device *dev)
37 {
38 return container_of(dev, struct iblock_dev, dev);
39 }
40
41
42 static int iblock_attach_hba(struct se_hba *hba, u32 host_id)
43 {
44 pr_debug("CORE_HBA[%d] - TCM iBlock HBA Driver %s on"
45 " Generic Target Core Stack %s\n", hba->hba_id,
46 IBLOCK_VERSION, TARGET_CORE_VERSION);
47 return 0;
48 }
49
50 static void iblock_detach_hba(struct se_hba *hba)
51 {
52 }
53
54 static struct se_device *iblock_alloc_device(struct se_hba *hba, const char *name)
55 {
56 struct iblock_dev *ib_dev = NULL;
57
58 ib_dev = kzalloc(sizeof(struct iblock_dev), GFP_KERNEL);
59 if (!ib_dev) {
60 pr_err("Unable to allocate struct iblock_dev\n");
61 return NULL;
62 }
63
64 pr_debug( "IBLOCK: Allocated ib_dev for %s\n", name);
65
66 return &ib_dev->dev;
67 }
68
69 static int iblock_configure_device(struct se_device *dev)
70 {
71 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
72 struct request_queue *q;
73 struct block_device *bd = NULL;
74 struct blk_integrity *bi;
75 fmode_t mode;
76 unsigned int max_write_zeroes_sectors;
77 int ret = -ENOMEM;
78
79 if (!(ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)) {
80 pr_err("Missing udev_path= parameters for IBLOCK\n");
81 return -EINVAL;
82 }
83
84 ret = bioset_init(&ib_dev->ibd_bio_set, IBLOCK_BIO_POOL_SIZE, 0, BIOSET_NEED_BVECS);
85 if (ret) {
86 pr_err("IBLOCK: Unable to create bioset\n");
87 goto out;
88 }
89
90 pr_debug( "IBLOCK: Claiming struct block_device: %s\n",
91 ib_dev->ibd_udev_path);
92
93 mode = FMODE_READ|FMODE_EXCL;
94 if (!ib_dev->ibd_readonly)
95 mode |= FMODE_WRITE;
96 else
97 dev->dev_flags |= DF_READ_ONLY;
98
99 bd = blkdev_get_by_path(ib_dev->ibd_udev_path, mode, ib_dev);
100 if (IS_ERR(bd)) {
101 ret = PTR_ERR(bd);
102 goto out_free_bioset;
103 }
104 ib_dev->ibd_bd = bd;
105
106 q = bdev_get_queue(bd);
107
108 dev->dev_attrib.hw_block_size = bdev_logical_block_size(bd);
109 dev->dev_attrib.hw_max_sectors = queue_max_hw_sectors(q);
110 dev->dev_attrib.hw_queue_depth = q->nr_requests;
111
112 if (target_configure_unmap_from_queue(&dev->dev_attrib, q))
113 pr_debug("IBLOCK: BLOCK Discard support available,"
114 " disabled by default\n");
115
116 /*
117 * Enable write same emulation for IBLOCK and use 0xFFFF as
118 * the smaller WRITE_SAME(10) only has a two-byte block count.
119 */
120 max_write_zeroes_sectors = bdev_write_zeroes_sectors(bd);
121 if (max_write_zeroes_sectors)
122 dev->dev_attrib.max_write_same_len = max_write_zeroes_sectors;
123 else
124 dev->dev_attrib.max_write_same_len = 0xFFFF;
125
126 if (blk_queue_nonrot(q))
127 dev->dev_attrib.is_nonrot = 1;
128
129 bi = bdev_get_integrity(bd);
130 if (bi) {
131 struct bio_set *bs = &ib_dev->ibd_bio_set;
132
133 if (!strcmp(bi->profile->name, "T10-DIF-TYPE3-IP") ||
134 !strcmp(bi->profile->name, "T10-DIF-TYPE1-IP")) {
135 pr_err("IBLOCK export of blk_integrity: %s not"
136 " supported\n", bi->profile->name);
137 ret = -ENOSYS;
138 goto out_blkdev_put;
139 }
140
141 if (!strcmp(bi->profile->name, "T10-DIF-TYPE3-CRC")) {
142 dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE3_PROT;
143 } else if (!strcmp(bi->profile->name, "T10-DIF-TYPE1-CRC")) {
144 dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE1_PROT;
145 }
146
147 if (dev->dev_attrib.pi_prot_type) {
148 if (bioset_integrity_create(bs, IBLOCK_BIO_POOL_SIZE) < 0) {
149 pr_err("Unable to allocate bioset for PI\n");
150 ret = -ENOMEM;
151 goto out_blkdev_put;
152 }
153 pr_debug("IBLOCK setup BIP bs->bio_integrity_pool: %p\n",
154 &bs->bio_integrity_pool);
155 }
156 dev->dev_attrib.hw_pi_prot_type = dev->dev_attrib.pi_prot_type;
157 }
158
159 return 0;
160
161 out_blkdev_put:
162 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
163 out_free_bioset:
164 bioset_exit(&ib_dev->ibd_bio_set);
165 out:
166 return ret;
167 }
168
169 static void iblock_dev_call_rcu(struct rcu_head *p)
170 {
171 struct se_device *dev = container_of(p, struct se_device, rcu_head);
172 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
173
174 kfree(ib_dev);
175 }
176
177 static void iblock_free_device(struct se_device *dev)
178 {
179 call_rcu(&dev->rcu_head, iblock_dev_call_rcu);
180 }
181
182 static void iblock_destroy_device(struct se_device *dev)
183 {
184 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
185
186 if (ib_dev->ibd_bd != NULL)
187 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
188 bioset_exit(&ib_dev->ibd_bio_set);
189 }
190
191 static unsigned long long iblock_emulate_read_cap_with_block_size(
192 struct se_device *dev,
193 struct block_device *bd,
194 struct request_queue *q)
195 {
196 unsigned long long blocks_long = (div_u64(i_size_read(bd->bd_inode),
197 bdev_logical_block_size(bd)) - 1);
198 u32 block_size = bdev_logical_block_size(bd);
199
200 if (block_size == dev->dev_attrib.block_size)
201 return blocks_long;
202
203 switch (block_size) {
204 case 4096:
205 switch (dev->dev_attrib.block_size) {
206 case 2048:
207 blocks_long <<= 1;
208 break;
209 case 1024:
210 blocks_long <<= 2;
211 break;
212 case 512:
213 blocks_long <<= 3;
214 break;
215 default:
216 break;
217 }
218 break;
219 case 2048:
220 switch (dev->dev_attrib.block_size) {
221 case 4096:
222 blocks_long >>= 1;
223 break;
224 case 1024:
225 blocks_long <<= 1;
226 break;
227 case 512:
228 blocks_long <<= 2;
229 break;
230 default:
231 break;
232 }
233 break;
234 case 1024:
235 switch (dev->dev_attrib.block_size) {
236 case 4096:
237 blocks_long >>= 2;
238 break;
239 case 2048:
240 blocks_long >>= 1;
241 break;
242 case 512:
243 blocks_long <<= 1;
244 break;
245 default:
246 break;
247 }
248 break;
249 case 512:
250 switch (dev->dev_attrib.block_size) {
251 case 4096:
252 blocks_long >>= 3;
253 break;
254 case 2048:
255 blocks_long >>= 2;
256 break;
257 case 1024:
258 blocks_long >>= 1;
259 break;
260 default:
261 break;
262 }
263 break;
264 default:
265 break;
266 }
267
268 return blocks_long;
269 }
270
271 static void iblock_complete_cmd(struct se_cmd *cmd)
272 {
273 struct iblock_req *ibr = cmd->priv;
274 u8 status;
275
276 if (!refcount_dec_and_test(&ibr->pending))
277 return;
278
279 if (atomic_read(&ibr->ib_bio_err_cnt))
280 status = SAM_STAT_CHECK_CONDITION;
281 else
282 status = SAM_STAT_GOOD;
283
284 target_complete_cmd(cmd, status);
285 kfree(ibr);
286 }
287
288 static void iblock_bio_done(struct bio *bio)
289 {
290 struct se_cmd *cmd = bio->bi_private;
291 struct iblock_req *ibr = cmd->priv;
292
293 if (bio->bi_status) {
294 pr_err("bio error: %p, err: %d\n", bio, bio->bi_status);
295 /*
296 * Bump the ib_bio_err_cnt and release bio.
297 */
298 atomic_inc(&ibr->ib_bio_err_cnt);
299 smp_mb__after_atomic();
300 }
301
302 bio_put(bio);
303
304 iblock_complete_cmd(cmd);
305 }
306
307 static struct bio *
308 iblock_get_bio(struct se_cmd *cmd, sector_t lba, u32 sg_num, int op,
309 int op_flags)
310 {
311 struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
312 struct bio *bio;
313
314 /*
315 * Only allocate as many vector entries as the bio code allows us to,
316 * we'll loop later on until we have handled the whole request.
317 */
318 if (sg_num > BIO_MAX_PAGES)
319 sg_num = BIO_MAX_PAGES;
320
321 bio = bio_alloc_bioset(GFP_NOIO, sg_num, &ib_dev->ibd_bio_set);
322 if (!bio) {
323 pr_err("Unable to allocate memory for bio\n");
324 return NULL;
325 }
326
327 bio_set_dev(bio, ib_dev->ibd_bd);
328 bio->bi_private = cmd;
329 bio->bi_end_io = &iblock_bio_done;
330 bio->bi_iter.bi_sector = lba;
331 bio_set_op_attrs(bio, op, op_flags);
332
333 return bio;
334 }
335
336 static void iblock_submit_bios(struct bio_list *list)
337 {
338 struct blk_plug plug;
339 struct bio *bio;
340
341 blk_start_plug(&plug);
342 while ((bio = bio_list_pop(list)))
343 submit_bio(bio);
344 blk_finish_plug(&plug);
345 }
346
347 static void iblock_end_io_flush(struct bio *bio)
348 {
349 struct se_cmd *cmd = bio->bi_private;
350
351 if (bio->bi_status)
352 pr_err("IBLOCK: cache flush failed: %d\n", bio->bi_status);
353
354 if (cmd) {
355 if (bio->bi_status)
356 target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
357 else
358 target_complete_cmd(cmd, SAM_STAT_GOOD);
359 }
360
361 bio_put(bio);
362 }
363
364 /*
365 * Implement SYCHRONIZE CACHE. Note that we can't handle lba ranges and must
366 * always flush the whole cache.
367 */
368 static sense_reason_t
369 iblock_execute_sync_cache(struct se_cmd *cmd)
370 {
371 struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
372 int immed = (cmd->t_task_cdb[1] & 0x2);
373 struct bio *bio;
374
375 /*
376 * If the Immediate bit is set, queue up the GOOD response
377 * for this SYNCHRONIZE_CACHE op.
378 */
379 if (immed)
380 target_complete_cmd(cmd, SAM_STAT_GOOD);
381
382 bio = bio_alloc(GFP_KERNEL, 0);
383 bio->bi_end_io = iblock_end_io_flush;
384 bio_set_dev(bio, ib_dev->ibd_bd);
385 bio->bi_opf = REQ_OP_WRITE | REQ_PREFLUSH;
386 if (!immed)
387 bio->bi_private = cmd;
388 submit_bio(bio);
389 return 0;
390 }
391
392 static sense_reason_t
393 iblock_execute_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
394 {
395 struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
396 struct se_device *dev = cmd->se_dev;
397 int ret;
398
399 ret = blkdev_issue_discard(bdev,
400 target_to_linux_sector(dev, lba),
401 target_to_linux_sector(dev, nolb),
402 GFP_KERNEL, 0);
403 if (ret < 0) {
404 pr_err("blkdev_issue_discard() failed: %d\n", ret);
405 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
406 }
407
408 return 0;
409 }
410
411 static sense_reason_t
412 iblock_execute_zero_out(struct block_device *bdev, struct se_cmd *cmd)
413 {
414 struct se_device *dev = cmd->se_dev;
415 struct scatterlist *sg = &cmd->t_data_sg[0];
416 unsigned char *buf, *not_zero;
417 int ret;
418
419 buf = kmap(sg_page(sg)) + sg->offset;
420 if (!buf)
421 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
422 /*
423 * Fall back to block_execute_write_same() slow-path if
424 * incoming WRITE_SAME payload does not contain zeros.
425 */
426 not_zero = memchr_inv(buf, 0x00, cmd->data_length);
427 kunmap(sg_page(sg));
428
429 if (not_zero)
430 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
431
432 ret = blkdev_issue_zeroout(bdev,
433 target_to_linux_sector(dev, cmd->t_task_lba),
434 target_to_linux_sector(dev,
435 sbc_get_write_same_sectors(cmd)),
436 GFP_KERNEL, BLKDEV_ZERO_NOUNMAP);
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_zeroes_sectors(bdev)) {
473 if (!iblock_execute_zero_out(bdev, cmd))
474 return 0;
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, REQ_OP_WRITE, 0);
483 if (!bio)
484 goto fail_free_ibr;
485
486 bio_list_init(&list);
487 bio_list_add(&list, bio);
488
489 refcount_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, REQ_OP_WRITE,
496 0);
497 if (!bio)
498 goto fail_put_bios;
499
500 refcount_inc(&ibr->pending);
501 bio_list_add(&list, bio);
502 }
503
504 /* Always in 512 byte units for Linux/Block */
505 block_lba += sg->length >> SECTOR_SHIFT;
506 sectors -= sg->length >> SECTOR_SHIFT;
507 }
508
509 iblock_submit_bios(&list);
510 return 0;
511
512 fail_put_bios:
513 while ((bio = bio_list_pop(&list)))
514 bio_put(bio);
515 fail_free_ibr:
516 kfree(ibr);
517 fail:
518 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
519 }
520
521 enum {
522 Opt_udev_path, Opt_readonly, Opt_force, Opt_err
523 };
524
525 static match_table_t tokens = {
526 {Opt_udev_path, "udev_path=%s"},
527 {Opt_readonly, "readonly=%d"},
528 {Opt_force, "force=%d"},
529 {Opt_err, NULL}
530 };
531
532 static ssize_t iblock_set_configfs_dev_params(struct se_device *dev,
533 const char *page, ssize_t count)
534 {
535 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
536 char *orig, *ptr, *arg_p, *opts;
537 substring_t args[MAX_OPT_ARGS];
538 int ret = 0, token;
539 unsigned long tmp_readonly;
540
541 opts = kstrdup(page, GFP_KERNEL);
542 if (!opts)
543 return -ENOMEM;
544
545 orig = opts;
546
547 while ((ptr = strsep(&opts, ",\n")) != NULL) {
548 if (!*ptr)
549 continue;
550
551 token = match_token(ptr, tokens, args);
552 switch (token) {
553 case Opt_udev_path:
554 if (ib_dev->ibd_bd) {
555 pr_err("Unable to set udev_path= while"
556 " ib_dev->ibd_bd exists\n");
557 ret = -EEXIST;
558 goto out;
559 }
560 if (match_strlcpy(ib_dev->ibd_udev_path, &args[0],
561 SE_UDEV_PATH_LEN) == 0) {
562 ret = -EINVAL;
563 break;
564 }
565 pr_debug("IBLOCK: Referencing UDEV path: %s\n",
566 ib_dev->ibd_udev_path);
567 ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH;
568 break;
569 case Opt_readonly:
570 arg_p = match_strdup(&args[0]);
571 if (!arg_p) {
572 ret = -ENOMEM;
573 break;
574 }
575 ret = kstrtoul(arg_p, 0, &tmp_readonly);
576 kfree(arg_p);
577 if (ret < 0) {
578 pr_err("kstrtoul() failed for"
579 " readonly=\n");
580 goto out;
581 }
582 ib_dev->ibd_readonly = tmp_readonly;
583 pr_debug("IBLOCK: readonly: %d\n", ib_dev->ibd_readonly);
584 break;
585 case Opt_force:
586 break;
587 default:
588 break;
589 }
590 }
591
592 out:
593 kfree(orig);
594 return (!ret) ? count : ret;
595 }
596
597 static ssize_t iblock_show_configfs_dev_params(struct se_device *dev, char *b)
598 {
599 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
600 struct block_device *bd = ib_dev->ibd_bd;
601 char buf[BDEVNAME_SIZE];
602 ssize_t bl = 0;
603
604 if (bd)
605 bl += sprintf(b + bl, "iBlock device: %s",
606 bdevname(bd, buf));
607 if (ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)
608 bl += sprintf(b + bl, " UDEV PATH: %s",
609 ib_dev->ibd_udev_path);
610 bl += sprintf(b + bl, " readonly: %d\n", ib_dev->ibd_readonly);
611
612 bl += sprintf(b + bl, " ");
613 if (bd) {
614 bl += sprintf(b + bl, "Major: %d Minor: %d %s\n",
615 MAJOR(bd->bd_dev), MINOR(bd->bd_dev),
616 "CLAIMED: IBLOCK");
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 struct sg_mapping_iter *miter)
627 {
628 struct se_device *dev = cmd->se_dev;
629 struct blk_integrity *bi;
630 struct bio_integrity_payload *bip;
631 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
632 int rc;
633 size_t resid, len;
634
635 bi = bdev_get_integrity(ib_dev->ibd_bd);
636 if (!bi) {
637 pr_err("Unable to locate bio_integrity\n");
638 return -ENODEV;
639 }
640
641 bip = bio_integrity_alloc(bio, GFP_NOIO,
642 min_t(unsigned int, cmd->t_prot_nents, BIO_MAX_PAGES));
643 if (IS_ERR(bip)) {
644 pr_err("Unable to allocate bio_integrity_payload\n");
645 return PTR_ERR(bip);
646 }
647
648 bip->bip_iter.bi_size = bio_integrity_bytes(bi, bio_sectors(bio));
649 /* virtual start sector must be in integrity interval units */
650 bip_set_seed(bip, bio->bi_iter.bi_sector >>
651 (bi->interval_exp - SECTOR_SHIFT));
652
653 pr_debug("IBLOCK BIP Size: %u Sector: %llu\n", bip->bip_iter.bi_size,
654 (unsigned long long)bip->bip_iter.bi_sector);
655
656 resid = bip->bip_iter.bi_size;
657 while (resid > 0 && sg_miter_next(miter)) {
658
659 len = min_t(size_t, miter->length, resid);
660 rc = bio_integrity_add_page(bio, miter->page, len,
661 offset_in_page(miter->addr));
662 if (rc != len) {
663 pr_err("bio_integrity_add_page() failed; %d\n", rc);
664 sg_miter_stop(miter);
665 return -ENOMEM;
666 }
667
668 pr_debug("Added bio integrity page: %p length: %zu offset: %lu\n",
669 miter->page, len, offset_in_page(miter->addr));
670
671 resid -= len;
672 if (len < miter->length)
673 miter->consumed -= miter->length - len;
674 }
675 sg_miter_stop(miter);
676
677 return 0;
678 }
679
680 static sense_reason_t
681 iblock_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
682 enum dma_data_direction data_direction)
683 {
684 struct se_device *dev = cmd->se_dev;
685 sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba);
686 struct iblock_req *ibr;
687 struct bio *bio;
688 struct bio_list list;
689 struct scatterlist *sg;
690 u32 sg_num = sgl_nents;
691 unsigned bio_cnt;
692 int i, rc, op, op_flags = 0;
693 struct sg_mapping_iter prot_miter;
694
695 if (data_direction == DMA_TO_DEVICE) {
696 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
697 struct request_queue *q = bdev_get_queue(ib_dev->ibd_bd);
698 /*
699 * Force writethrough using REQ_FUA if a volatile write cache
700 * is not enabled, or if initiator set the Force Unit Access bit.
701 */
702 op = REQ_OP_WRITE;
703 if (test_bit(QUEUE_FLAG_FUA, &q->queue_flags)) {
704 if (cmd->se_cmd_flags & SCF_FUA)
705 op_flags = REQ_FUA;
706 else if (!test_bit(QUEUE_FLAG_WC, &q->queue_flags))
707 op_flags = REQ_FUA;
708 }
709 } else {
710 op = REQ_OP_READ;
711 }
712
713 ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
714 if (!ibr)
715 goto fail;
716 cmd->priv = ibr;
717
718 if (!sgl_nents) {
719 refcount_set(&ibr->pending, 1);
720 iblock_complete_cmd(cmd);
721 return 0;
722 }
723
724 bio = iblock_get_bio(cmd, block_lba, sgl_nents, op, op_flags);
725 if (!bio)
726 goto fail_free_ibr;
727
728 bio_list_init(&list);
729 bio_list_add(&list, bio);
730
731 refcount_set(&ibr->pending, 2);
732 bio_cnt = 1;
733
734 if (cmd->prot_type && dev->dev_attrib.pi_prot_type)
735 sg_miter_start(&prot_miter, cmd->t_prot_sg, cmd->t_prot_nents,
736 op == REQ_OP_READ ? SG_MITER_FROM_SG :
737 SG_MITER_TO_SG);
738
739 for_each_sg(sgl, sg, sgl_nents, i) {
740 /*
741 * XXX: if the length the device accepts is shorter than the
742 * length of the S/G list entry this will cause and
743 * endless loop. Better hope no driver uses huge pages.
744 */
745 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
746 != sg->length) {
747 if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
748 rc = iblock_alloc_bip(cmd, bio, &prot_miter);
749 if (rc)
750 goto fail_put_bios;
751 }
752
753 if (bio_cnt >= IBLOCK_MAX_BIO_PER_TASK) {
754 iblock_submit_bios(&list);
755 bio_cnt = 0;
756 }
757
758 bio = iblock_get_bio(cmd, block_lba, sg_num, op,
759 op_flags);
760 if (!bio)
761 goto fail_put_bios;
762
763 refcount_inc(&ibr->pending);
764 bio_list_add(&list, bio);
765 bio_cnt++;
766 }
767
768 /* Always in 512 byte units for Linux/Block */
769 block_lba += sg->length >> SECTOR_SHIFT;
770 sg_num--;
771 }
772
773 if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
774 rc = iblock_alloc_bip(cmd, bio, &prot_miter);
775 if (rc)
776 goto fail_put_bios;
777 }
778
779 iblock_submit_bios(&list);
780 iblock_complete_cmd(cmd);
781 return 0;
782
783 fail_put_bios:
784 while ((bio = bio_list_pop(&list)))
785 bio_put(bio);
786 fail_free_ibr:
787 kfree(ibr);
788 fail:
789 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
790 }
791
792 static sector_t iblock_get_blocks(struct se_device *dev)
793 {
794 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
795 struct block_device *bd = ib_dev->ibd_bd;
796 struct request_queue *q = bdev_get_queue(bd);
797
798 return iblock_emulate_read_cap_with_block_size(dev, bd, q);
799 }
800
801 static sector_t iblock_get_alignment_offset_lbas(struct se_device *dev)
802 {
803 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
804 struct block_device *bd = ib_dev->ibd_bd;
805 int ret;
806
807 ret = bdev_alignment_offset(bd);
808 if (ret == -1)
809 return 0;
810
811 /* convert offset-bytes to offset-lbas */
812 return ret / bdev_logical_block_size(bd);
813 }
814
815 static unsigned int iblock_get_lbppbe(struct se_device *dev)
816 {
817 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
818 struct block_device *bd = ib_dev->ibd_bd;
819 int logs_per_phys = bdev_physical_block_size(bd) / bdev_logical_block_size(bd);
820
821 return ilog2(logs_per_phys);
822 }
823
824 static unsigned int iblock_get_io_min(struct se_device *dev)
825 {
826 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
827 struct block_device *bd = ib_dev->ibd_bd;
828
829 return bdev_io_min(bd);
830 }
831
832 static unsigned int iblock_get_io_opt(struct se_device *dev)
833 {
834 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
835 struct block_device *bd = ib_dev->ibd_bd;
836
837 return bdev_io_opt(bd);
838 }
839
840 static struct sbc_ops iblock_sbc_ops = {
841 .execute_rw = iblock_execute_rw,
842 .execute_sync_cache = iblock_execute_sync_cache,
843 .execute_write_same = iblock_execute_write_same,
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 test_bit(QUEUE_FLAG_WC, &q->queue_flags);
860 }
861
862 static const struct target_backend_ops iblock_ops = {
863 .name = "iblock",
864 .inquiry_prod = "IBLOCK",
865 .inquiry_rev = IBLOCK_VERSION,
866 .owner = THIS_MODULE,
867 .attach_hba = iblock_attach_hba,
868 .detach_hba = iblock_detach_hba,
869 .alloc_device = iblock_alloc_device,
870 .configure_device = iblock_configure_device,
871 .destroy_device = iblock_destroy_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 .tb_dev_attrib_attrs = sbc_attrib_attrs,
884 };
885
886 static int __init iblock_module_init(void)
887 {
888 return transport_backend_register(&iblock_ops);
889 }
890
891 static void __exit iblock_module_exit(void)
892 {
893 target_backend_unregister(&iblock_ops);
894 }
895
896 MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin");
897 MODULE_AUTHOR("nab@Linux-iSCSI.org");
898 MODULE_LICENSE("GPL");
899
900 module_init(iblock_module_init);
901 module_exit(iblock_module_exit);
Linux with added FPC-III support