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nvme: use a work item to submit async event requests
[deliverable/linux.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 /*
125 * Check if the underlying struct block_device request_queue supports
126 * the QUEUE_FLAG_DISCARD bit for UNMAP/WRITE_SAME in SCSI + TRIM
127 * in ATA and we need to set TPE=1
128 */
129 if (blk_queue_discard(q)) {
130 dev->dev_attrib.max_unmap_lba_count =
131 q->limits.max_discard_sectors;
132
133 /*
134 * Currently hardcoded to 1 in Linux/SCSI code..
135 */
136 dev->dev_attrib.max_unmap_block_desc_count = 1;
137 dev->dev_attrib.unmap_granularity =
138 q->limits.discard_granularity >> 9;
139 dev->dev_attrib.unmap_granularity_alignment =
140 q->limits.discard_alignment;
141 dev->dev_attrib.unmap_zeroes_data =
142 q->limits.discard_zeroes_data;
143
144 pr_debug("IBLOCK: BLOCK Discard support available,"
145 " disabled by default\n");
146 }
147 /*
148 * Enable write same emulation for IBLOCK and use 0xFFFF as
149 * the smaller WRITE_SAME(10) only has a two-byte block count.
150 */
151 dev->dev_attrib.max_write_same_len = 0xFFFF;
152
153 if (blk_queue_nonrot(q))
154 dev->dev_attrib.is_nonrot = 1;
155
156 bi = bdev_get_integrity(bd);
157 if (bi) {
158 struct bio_set *bs = ib_dev->ibd_bio_set;
159
160 if (!strcmp(bi->profile->name, "T10-DIF-TYPE3-IP") ||
161 !strcmp(bi->profile->name, "T10-DIF-TYPE1-IP")) {
162 pr_err("IBLOCK export of blk_integrity: %s not"
163 " supported\n", bi->profile->name);
164 ret = -ENOSYS;
165 goto out_blkdev_put;
166 }
167
168 if (!strcmp(bi->profile->name, "T10-DIF-TYPE3-CRC")) {
169 dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE3_PROT;
170 } else if (!strcmp(bi->profile->name, "T10-DIF-TYPE1-CRC")) {
171 dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE1_PROT;
172 }
173
174 if (dev->dev_attrib.pi_prot_type) {
175 if (bioset_integrity_create(bs, IBLOCK_BIO_POOL_SIZE) < 0) {
176 pr_err("Unable to allocate bioset for PI\n");
177 ret = -ENOMEM;
178 goto out_blkdev_put;
179 }
180 pr_debug("IBLOCK setup BIP bs->bio_integrity_pool: %p\n",
181 bs->bio_integrity_pool);
182 }
183 dev->dev_attrib.hw_pi_prot_type = dev->dev_attrib.pi_prot_type;
184 }
185
186 return 0;
187
188 out_blkdev_put:
189 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
190 out_free_bioset:
191 bioset_free(ib_dev->ibd_bio_set);
192 ib_dev->ibd_bio_set = NULL;
193 out:
194 return ret;
195 }
196
197 static void iblock_dev_call_rcu(struct rcu_head *p)
198 {
199 struct se_device *dev = container_of(p, struct se_device, rcu_head);
200 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
201
202 kfree(ib_dev);
203 }
204
205 static void iblock_free_device(struct se_device *dev)
206 {
207 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
208
209 if (ib_dev->ibd_bd != NULL)
210 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
211 if (ib_dev->ibd_bio_set != NULL)
212 bioset_free(ib_dev->ibd_bio_set);
213
214 call_rcu(&dev->rcu_head, iblock_dev_call_rcu);
215 }
216
217 static unsigned long long iblock_emulate_read_cap_with_block_size(
218 struct se_device *dev,
219 struct block_device *bd,
220 struct request_queue *q)
221 {
222 unsigned long long blocks_long = (div_u64(i_size_read(bd->bd_inode),
223 bdev_logical_block_size(bd)) - 1);
224 u32 block_size = bdev_logical_block_size(bd);
225
226 if (block_size == dev->dev_attrib.block_size)
227 return blocks_long;
228
229 switch (block_size) {
230 case 4096:
231 switch (dev->dev_attrib.block_size) {
232 case 2048:
233 blocks_long <<= 1;
234 break;
235 case 1024:
236 blocks_long <<= 2;
237 break;
238 case 512:
239 blocks_long <<= 3;
240 default:
241 break;
242 }
243 break;
244 case 2048:
245 switch (dev->dev_attrib.block_size) {
246 case 4096:
247 blocks_long >>= 1;
248 break;
249 case 1024:
250 blocks_long <<= 1;
251 break;
252 case 512:
253 blocks_long <<= 2;
254 break;
255 default:
256 break;
257 }
258 break;
259 case 1024:
260 switch (dev->dev_attrib.block_size) {
261 case 4096:
262 blocks_long >>= 2;
263 break;
264 case 2048:
265 blocks_long >>= 1;
266 break;
267 case 512:
268 blocks_long <<= 1;
269 break;
270 default:
271 break;
272 }
273 break;
274 case 512:
275 switch (dev->dev_attrib.block_size) {
276 case 4096:
277 blocks_long >>= 3;
278 break;
279 case 2048:
280 blocks_long >>= 2;
281 break;
282 case 1024:
283 blocks_long >>= 1;
284 break;
285 default:
286 break;
287 }
288 break;
289 default:
290 break;
291 }
292
293 return blocks_long;
294 }
295
296 static void iblock_complete_cmd(struct se_cmd *cmd)
297 {
298 struct iblock_req *ibr = cmd->priv;
299 u8 status;
300
301 if (!atomic_dec_and_test(&ibr->pending))
302 return;
303
304 if (atomic_read(&ibr->ib_bio_err_cnt))
305 status = SAM_STAT_CHECK_CONDITION;
306 else
307 status = SAM_STAT_GOOD;
308
309 target_complete_cmd(cmd, status);
310 kfree(ibr);
311 }
312
313 static void iblock_bio_done(struct bio *bio)
314 {
315 struct se_cmd *cmd = bio->bi_private;
316 struct iblock_req *ibr = cmd->priv;
317
318 if (bio->bi_error) {
319 pr_err("bio error: %p, err: %d\n", bio, bio->bi_error);
320 /*
321 * Bump the ib_bio_err_cnt and release bio.
322 */
323 atomic_inc(&ibr->ib_bio_err_cnt);
324 smp_mb__after_atomic();
325 }
326
327 bio_put(bio);
328
329 iblock_complete_cmd(cmd);
330 }
331
332 static struct bio *
333 iblock_get_bio(struct se_cmd *cmd, sector_t lba, u32 sg_num)
334 {
335 struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
336 struct bio *bio;
337
338 /*
339 * Only allocate as many vector entries as the bio code allows us to,
340 * we'll loop later on until we have handled the whole request.
341 */
342 if (sg_num > BIO_MAX_PAGES)
343 sg_num = BIO_MAX_PAGES;
344
345 bio = bio_alloc_bioset(GFP_NOIO, sg_num, ib_dev->ibd_bio_set);
346 if (!bio) {
347 pr_err("Unable to allocate memory for bio\n");
348 return NULL;
349 }
350
351 bio->bi_bdev = ib_dev->ibd_bd;
352 bio->bi_private = cmd;
353 bio->bi_end_io = &iblock_bio_done;
354 bio->bi_iter.bi_sector = lba;
355
356 return bio;
357 }
358
359 static void iblock_submit_bios(struct bio_list *list, int rw)
360 {
361 struct blk_plug plug;
362 struct bio *bio;
363
364 blk_start_plug(&plug);
365 while ((bio = bio_list_pop(list)))
366 submit_bio(rw, bio);
367 blk_finish_plug(&plug);
368 }
369
370 static void iblock_end_io_flush(struct bio *bio)
371 {
372 struct se_cmd *cmd = bio->bi_private;
373
374 if (bio->bi_error)
375 pr_err("IBLOCK: cache flush failed: %d\n", bio->bi_error);
376
377 if (cmd) {
378 if (bio->bi_error)
379 target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
380 else
381 target_complete_cmd(cmd, SAM_STAT_GOOD);
382 }
383
384 bio_put(bio);
385 }
386
387 /*
388 * Implement SYCHRONIZE CACHE. Note that we can't handle lba ranges and must
389 * always flush the whole cache.
390 */
391 static sense_reason_t
392 iblock_execute_sync_cache(struct se_cmd *cmd)
393 {
394 struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
395 int immed = (cmd->t_task_cdb[1] & 0x2);
396 struct bio *bio;
397
398 /*
399 * If the Immediate bit is set, queue up the GOOD response
400 * for this SYNCHRONIZE_CACHE op.
401 */
402 if (immed)
403 target_complete_cmd(cmd, SAM_STAT_GOOD);
404
405 bio = bio_alloc(GFP_KERNEL, 0);
406 bio->bi_end_io = iblock_end_io_flush;
407 bio->bi_bdev = ib_dev->ibd_bd;
408 if (!immed)
409 bio->bi_private = cmd;
410 submit_bio(WRITE_FLUSH, bio);
411 return 0;
412 }
413
414 static sense_reason_t
415 iblock_execute_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
416 {
417 struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
418 int ret;
419
420 ret = blkdev_issue_discard(bdev, lba, nolb, GFP_KERNEL, 0);
421 if (ret < 0) {
422 pr_err("blkdev_issue_discard() failed: %d\n", ret);
423 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
424 }
425
426 return 0;
427 }
428
429 static sense_reason_t
430 iblock_execute_write_same(struct se_cmd *cmd)
431 {
432 struct iblock_req *ibr;
433 struct scatterlist *sg;
434 struct bio *bio;
435 struct bio_list list;
436 sector_t block_lba = cmd->t_task_lba;
437 sector_t sectors = sbc_get_write_same_sectors(cmd);
438
439 if (cmd->prot_op) {
440 pr_err("WRITE_SAME: Protection information with IBLOCK"
441 " backends not supported\n");
442 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
443 }
444 sg = &cmd->t_data_sg[0];
445
446 if (cmd->t_data_nents > 1 ||
447 sg->length != cmd->se_dev->dev_attrib.block_size) {
448 pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
449 " block_size: %u\n", cmd->t_data_nents, sg->length,
450 cmd->se_dev->dev_attrib.block_size);
451 return TCM_INVALID_CDB_FIELD;
452 }
453
454 ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
455 if (!ibr)
456 goto fail;
457 cmd->priv = ibr;
458
459 bio = iblock_get_bio(cmd, block_lba, 1);
460 if (!bio)
461 goto fail_free_ibr;
462
463 bio_list_init(&list);
464 bio_list_add(&list, bio);
465
466 atomic_set(&ibr->pending, 1);
467
468 while (sectors) {
469 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
470 != sg->length) {
471
472 bio = iblock_get_bio(cmd, block_lba, 1);
473 if (!bio)
474 goto fail_put_bios;
475
476 atomic_inc(&ibr->pending);
477 bio_list_add(&list, bio);
478 }
479
480 /* Always in 512 byte units for Linux/Block */
481 block_lba += sg->length >> IBLOCK_LBA_SHIFT;
482 sectors -= 1;
483 }
484
485 iblock_submit_bios(&list, WRITE);
486 return 0;
487
488 fail_put_bios:
489 while ((bio = bio_list_pop(&list)))
490 bio_put(bio);
491 fail_free_ibr:
492 kfree(ibr);
493 fail:
494 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
495 }
496
497 enum {
498 Opt_udev_path, Opt_readonly, Opt_force, Opt_err
499 };
500
501 static match_table_t tokens = {
502 {Opt_udev_path, "udev_path=%s"},
503 {Opt_readonly, "readonly=%d"},
504 {Opt_force, "force=%d"},
505 {Opt_err, NULL}
506 };
507
508 static ssize_t iblock_set_configfs_dev_params(struct se_device *dev,
509 const char *page, ssize_t count)
510 {
511 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
512 char *orig, *ptr, *arg_p, *opts;
513 substring_t args[MAX_OPT_ARGS];
514 int ret = 0, token;
515 unsigned long tmp_readonly;
516
517 opts = kstrdup(page, GFP_KERNEL);
518 if (!opts)
519 return -ENOMEM;
520
521 orig = opts;
522
523 while ((ptr = strsep(&opts, ",\n")) != NULL) {
524 if (!*ptr)
525 continue;
526
527 token = match_token(ptr, tokens, args);
528 switch (token) {
529 case Opt_udev_path:
530 if (ib_dev->ibd_bd) {
531 pr_err("Unable to set udev_path= while"
532 " ib_dev->ibd_bd exists\n");
533 ret = -EEXIST;
534 goto out;
535 }
536 if (match_strlcpy(ib_dev->ibd_udev_path, &args[0],
537 SE_UDEV_PATH_LEN) == 0) {
538 ret = -EINVAL;
539 break;
540 }
541 pr_debug("IBLOCK: Referencing UDEV path: %s\n",
542 ib_dev->ibd_udev_path);
543 ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH;
544 break;
545 case Opt_readonly:
546 arg_p = match_strdup(&args[0]);
547 if (!arg_p) {
548 ret = -ENOMEM;
549 break;
550 }
551 ret = kstrtoul(arg_p, 0, &tmp_readonly);
552 kfree(arg_p);
553 if (ret < 0) {
554 pr_err("kstrtoul() failed for"
555 " readonly=\n");
556 goto out;
557 }
558 ib_dev->ibd_readonly = tmp_readonly;
559 pr_debug("IBLOCK: readonly: %d\n", ib_dev->ibd_readonly);
560 break;
561 case Opt_force:
562 break;
563 default:
564 break;
565 }
566 }
567
568 out:
569 kfree(orig);
570 return (!ret) ? count : ret;
571 }
572
573 static ssize_t iblock_show_configfs_dev_params(struct se_device *dev, char *b)
574 {
575 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
576 struct block_device *bd = ib_dev->ibd_bd;
577 char buf[BDEVNAME_SIZE];
578 ssize_t bl = 0;
579
580 if (bd)
581 bl += sprintf(b + bl, "iBlock device: %s",
582 bdevname(bd, buf));
583 if (ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)
584 bl += sprintf(b + bl, " UDEV PATH: %s",
585 ib_dev->ibd_udev_path);
586 bl += sprintf(b + bl, " readonly: %d\n", ib_dev->ibd_readonly);
587
588 bl += sprintf(b + bl, " ");
589 if (bd) {
590 bl += sprintf(b + bl, "Major: %d Minor: %d %s\n",
591 MAJOR(bd->bd_dev), MINOR(bd->bd_dev), (!bd->bd_contains) ?
592 "" : (bd->bd_holder == ib_dev) ?
593 "CLAIMED: IBLOCK" : "CLAIMED: OS");
594 } else {
595 bl += sprintf(b + bl, "Major: 0 Minor: 0\n");
596 }
597
598 return bl;
599 }
600
601 static int
602 iblock_alloc_bip(struct se_cmd *cmd, struct bio *bio)
603 {
604 struct se_device *dev = cmd->se_dev;
605 struct blk_integrity *bi;
606 struct bio_integrity_payload *bip;
607 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
608 struct scatterlist *sg;
609 int i, rc;
610
611 bi = bdev_get_integrity(ib_dev->ibd_bd);
612 if (!bi) {
613 pr_err("Unable to locate bio_integrity\n");
614 return -ENODEV;
615 }
616
617 bip = bio_integrity_alloc(bio, GFP_NOIO, cmd->t_prot_nents);
618 if (IS_ERR(bip)) {
619 pr_err("Unable to allocate bio_integrity_payload\n");
620 return PTR_ERR(bip);
621 }
622
623 bip->bip_iter.bi_size = (cmd->data_length / dev->dev_attrib.block_size) *
624 dev->prot_length;
625 bip->bip_iter.bi_sector = bio->bi_iter.bi_sector;
626
627 pr_debug("IBLOCK BIP Size: %u Sector: %llu\n", bip->bip_iter.bi_size,
628 (unsigned long long)bip->bip_iter.bi_sector);
629
630 for_each_sg(cmd->t_prot_sg, sg, cmd->t_prot_nents, i) {
631
632 rc = bio_integrity_add_page(bio, sg_page(sg), sg->length,
633 sg->offset);
634 if (rc != sg->length) {
635 pr_err("bio_integrity_add_page() failed; %d\n", rc);
636 return -ENOMEM;
637 }
638
639 pr_debug("Added bio integrity page: %p length: %d offset; %d\n",
640 sg_page(sg), sg->length, sg->offset);
641 }
642
643 return 0;
644 }
645
646 static sense_reason_t
647 iblock_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
648 enum dma_data_direction data_direction)
649 {
650 struct se_device *dev = cmd->se_dev;
651 struct iblock_req *ibr;
652 struct bio *bio, *bio_start;
653 struct bio_list list;
654 struct scatterlist *sg;
655 u32 sg_num = sgl_nents;
656 sector_t block_lba;
657 unsigned bio_cnt;
658 int rw = 0;
659 int i;
660
661 if (data_direction == DMA_TO_DEVICE) {
662 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
663 struct request_queue *q = bdev_get_queue(ib_dev->ibd_bd);
664 /*
665 * Force writethrough using WRITE_FUA if a volatile write cache
666 * is not enabled, or if initiator set the Force Unit Access bit.
667 */
668 if (q->flush_flags & REQ_FUA) {
669 if (cmd->se_cmd_flags & SCF_FUA)
670 rw = WRITE_FUA;
671 else if (!(q->flush_flags & REQ_FLUSH))
672 rw = WRITE_FUA;
673 else
674 rw = WRITE;
675 } else {
676 rw = WRITE;
677 }
678 } else {
679 rw = READ;
680 }
681
682 /*
683 * Convert the blocksize advertised to the initiator to the 512 byte
684 * units unconditionally used by the Linux block layer.
685 */
686 if (dev->dev_attrib.block_size == 4096)
687 block_lba = (cmd->t_task_lba << 3);
688 else if (dev->dev_attrib.block_size == 2048)
689 block_lba = (cmd->t_task_lba << 2);
690 else if (dev->dev_attrib.block_size == 1024)
691 block_lba = (cmd->t_task_lba << 1);
692 else if (dev->dev_attrib.block_size == 512)
693 block_lba = cmd->t_task_lba;
694 else {
695 pr_err("Unsupported SCSI -> BLOCK LBA conversion:"
696 " %u\n", dev->dev_attrib.block_size);
697 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
698 }
699
700 ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
701 if (!ibr)
702 goto fail;
703 cmd->priv = ibr;
704
705 if (!sgl_nents) {
706 atomic_set(&ibr->pending, 1);
707 iblock_complete_cmd(cmd);
708 return 0;
709 }
710
711 bio = iblock_get_bio(cmd, block_lba, sgl_nents);
712 if (!bio)
713 goto fail_free_ibr;
714
715 bio_start = bio;
716 bio_list_init(&list);
717 bio_list_add(&list, bio);
718
719 atomic_set(&ibr->pending, 2);
720 bio_cnt = 1;
721
722 for_each_sg(sgl, sg, sgl_nents, i) {
723 /*
724 * XXX: if the length the device accepts is shorter than the
725 * length of the S/G list entry this will cause and
726 * endless loop. Better hope no driver uses huge pages.
727 */
728 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
729 != sg->length) {
730 if (bio_cnt >= IBLOCK_MAX_BIO_PER_TASK) {
731 iblock_submit_bios(&list, rw);
732 bio_cnt = 0;
733 }
734
735 bio = iblock_get_bio(cmd, block_lba, sg_num);
736 if (!bio)
737 goto fail_put_bios;
738
739 atomic_inc(&ibr->pending);
740 bio_list_add(&list, bio);
741 bio_cnt++;
742 }
743
744 /* Always in 512 byte units for Linux/Block */
745 block_lba += sg->length >> IBLOCK_LBA_SHIFT;
746 sg_num--;
747 }
748
749 if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
750 int rc = iblock_alloc_bip(cmd, bio_start);
751 if (rc)
752 goto fail_put_bios;
753 }
754
755 iblock_submit_bios(&list, rw);
756 iblock_complete_cmd(cmd);
757 return 0;
758
759 fail_put_bios:
760 while ((bio = bio_list_pop(&list)))
761 bio_put(bio);
762 fail_free_ibr:
763 kfree(ibr);
764 fail:
765 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
766 }
767
768 static sector_t iblock_get_blocks(struct se_device *dev)
769 {
770 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
771 struct block_device *bd = ib_dev->ibd_bd;
772 struct request_queue *q = bdev_get_queue(bd);
773
774 return iblock_emulate_read_cap_with_block_size(dev, bd, q);
775 }
776
777 static sector_t iblock_get_alignment_offset_lbas(struct se_device *dev)
778 {
779 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
780 struct block_device *bd = ib_dev->ibd_bd;
781 int ret;
782
783 ret = bdev_alignment_offset(bd);
784 if (ret == -1)
785 return 0;
786
787 /* convert offset-bytes to offset-lbas */
788 return ret / bdev_logical_block_size(bd);
789 }
790
791 static unsigned int iblock_get_lbppbe(struct se_device *dev)
792 {
793 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
794 struct block_device *bd = ib_dev->ibd_bd;
795 int logs_per_phys = bdev_physical_block_size(bd) / bdev_logical_block_size(bd);
796
797 return ilog2(logs_per_phys);
798 }
799
800 static unsigned int iblock_get_io_min(struct se_device *dev)
801 {
802 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
803 struct block_device *bd = ib_dev->ibd_bd;
804
805 return bdev_io_min(bd);
806 }
807
808 static unsigned int iblock_get_io_opt(struct se_device *dev)
809 {
810 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
811 struct block_device *bd = ib_dev->ibd_bd;
812
813 return bdev_io_opt(bd);
814 }
815
816 static struct sbc_ops iblock_sbc_ops = {
817 .execute_rw = iblock_execute_rw,
818 .execute_sync_cache = iblock_execute_sync_cache,
819 .execute_write_same = iblock_execute_write_same,
820 .execute_unmap = iblock_execute_unmap,
821 };
822
823 static sense_reason_t
824 iblock_parse_cdb(struct se_cmd *cmd)
825 {
826 return sbc_parse_cdb(cmd, &iblock_sbc_ops);
827 }
828
829 static bool iblock_get_write_cache(struct se_device *dev)
830 {
831 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
832 struct block_device *bd = ib_dev->ibd_bd;
833 struct request_queue *q = bdev_get_queue(bd);
834
835 return q->flush_flags & REQ_FLUSH;
836 }
837
838 static const struct target_backend_ops iblock_ops = {
839 .name = "iblock",
840 .inquiry_prod = "IBLOCK",
841 .inquiry_rev = IBLOCK_VERSION,
842 .owner = THIS_MODULE,
843 .attach_hba = iblock_attach_hba,
844 .detach_hba = iblock_detach_hba,
845 .alloc_device = iblock_alloc_device,
846 .configure_device = iblock_configure_device,
847 .free_device = iblock_free_device,
848 .parse_cdb = iblock_parse_cdb,
849 .set_configfs_dev_params = iblock_set_configfs_dev_params,
850 .show_configfs_dev_params = iblock_show_configfs_dev_params,
851 .get_device_type = sbc_get_device_type,
852 .get_blocks = iblock_get_blocks,
853 .get_alignment_offset_lbas = iblock_get_alignment_offset_lbas,
854 .get_lbppbe = iblock_get_lbppbe,
855 .get_io_min = iblock_get_io_min,
856 .get_io_opt = iblock_get_io_opt,
857 .get_write_cache = iblock_get_write_cache,
858 .tb_dev_attrib_attrs = sbc_attrib_attrs,
859 };
860
861 static int __init iblock_module_init(void)
862 {
863 return transport_backend_register(&iblock_ops);
864 }
865
866 static void __exit iblock_module_exit(void)
867 {
868 target_backend_unregister(&iblock_ops);
869 }
870
871 MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin");
872 MODULE_AUTHOR("nab@Linux-iSCSI.org");
873 MODULE_LICENSE("GPL");
874
875 module_init(iblock_module_init);
876 module_exit(iblock_module_exit);
Linux kernel - Deliverables
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