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ext4: reduce contention on s_orphan_lock
[linux/fpc-iii.git] / drivers / target / target_core_iblock.c
blob9e0232cca92e03356c768e3dada2a27f53427452
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.h>
39 #include <scsi/scsi_host.h>
40 #include <asm/unaligned.h>
41
42 #include <target/target_core_base.h>
43 #include <target/target_core_backend.h>
44
45 #include "target_core_iblock.h"
46
47 #define IBLOCK_MAX_BIO_PER_TASK 32 /* max # of bios to submit at a time */
48 #define IBLOCK_BIO_POOL_SIZE 128
49
50 static inline struct iblock_dev *IBLOCK_DEV(struct se_device *dev)
51 {
52 return container_of(dev, struct iblock_dev, dev);
53 }
54
55
56 static struct se_subsystem_api iblock_template;
57
58 /* iblock_attach_hba(): (Part of se_subsystem_api_t template)
59 *
60 *
61 */
62 static int iblock_attach_hba(struct se_hba *hba, u32 host_id)
63 {
64 pr_debug("CORE_HBA[%d] - TCM iBlock HBA Driver %s on"
65 " Generic Target Core Stack %s\n", hba->hba_id,
66 IBLOCK_VERSION, TARGET_CORE_MOD_VERSION);
67 return 0;
68 }
69
70 static void iblock_detach_hba(struct se_hba *hba)
71 {
72 }
73
74 static struct se_device *iblock_alloc_device(struct se_hba *hba, const char *name)
75 {
76 struct iblock_dev *ib_dev = NULL;
77
78 ib_dev = kzalloc(sizeof(struct iblock_dev), GFP_KERNEL);
79 if (!ib_dev) {
80 pr_err("Unable to allocate struct iblock_dev\n");
81 return NULL;
82 }
83
84 pr_debug( "IBLOCK: Allocated ib_dev for %s\n", name);
85
86 return &ib_dev->dev;
87 }
88
89 static int iblock_configure_device(struct se_device *dev)
90 {
91 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
92 struct request_queue *q;
93 struct block_device *bd = NULL;
94 struct blk_integrity *bi;
95 fmode_t mode;
96 int ret = -ENOMEM;
97
98 if (!(ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)) {
99 pr_err("Missing udev_path= parameters for IBLOCK\n");
100 return -EINVAL;
101 }
102
103 ib_dev->ibd_bio_set = bioset_create(IBLOCK_BIO_POOL_SIZE, 0);
104 if (!ib_dev->ibd_bio_set) {
105 pr_err("IBLOCK: Unable to create bioset\n");
106 goto out;
107 }
108
109 pr_debug( "IBLOCK: Claiming struct block_device: %s\n",
110 ib_dev->ibd_udev_path);
111
112 mode = FMODE_READ|FMODE_EXCL;
113 if (!ib_dev->ibd_readonly)
114 mode |= FMODE_WRITE;
115
116 bd = blkdev_get_by_path(ib_dev->ibd_udev_path, mode, ib_dev);
117 if (IS_ERR(bd)) {
118 ret = PTR_ERR(bd);
119 goto out_free_bioset;
120 }
121 ib_dev->ibd_bd = bd;
122
123 q = bdev_get_queue(bd);
124
125 dev->dev_attrib.hw_block_size = bdev_logical_block_size(bd);
126 dev->dev_attrib.hw_max_sectors = UINT_MAX;
127 dev->dev_attrib.hw_queue_depth = q->nr_requests;
128
129 /*
130 * Check if the underlying struct block_device request_queue supports
131 * the QUEUE_FLAG_DISCARD bit for UNMAP/WRITE_SAME in SCSI + TRIM
132 * in ATA and we need to set TPE=1
133 */
134 if (blk_queue_discard(q)) {
135 dev->dev_attrib.max_unmap_lba_count =
136 q->limits.max_discard_sectors;
137
138 /*
139 * Currently hardcoded to 1 in Linux/SCSI code..
140 */
141 dev->dev_attrib.max_unmap_block_desc_count = 1;
142 dev->dev_attrib.unmap_granularity =
143 q->limits.discard_granularity >> 9;
144 dev->dev_attrib.unmap_granularity_alignment =
145 q->limits.discard_alignment;
146
147 pr_debug("IBLOCK: BLOCK Discard support available,"
148 " disabled by default\n");
149 }
150 /*
151 * Enable write same emulation for IBLOCK and use 0xFFFF as
152 * the smaller WRITE_SAME(10) only has a two-byte block count.
153 */
154 dev->dev_attrib.max_write_same_len = 0xFFFF;
155
156 if (blk_queue_nonrot(q))
157 dev->dev_attrib.is_nonrot = 1;
158
159 bi = bdev_get_integrity(bd);
160 if (bi) {
161 struct bio_set *bs = ib_dev->ibd_bio_set;
162
163 if (!strcmp(bi->name, "T10-DIF-TYPE3-IP") ||
164 !strcmp(bi->name, "T10-DIF-TYPE1-IP")) {
165 pr_err("IBLOCK export of blk_integrity: %s not"
166 " supported\n", bi->name);
167 ret = -ENOSYS;
168 goto out_blkdev_put;
169 }
170
171 if (!strcmp(bi->name, "T10-DIF-TYPE3-CRC")) {
172 dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE3_PROT;
173 } else if (!strcmp(bi->name, "T10-DIF-TYPE1-CRC")) {
174 dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE1_PROT;
175 }
176
177 if (dev->dev_attrib.pi_prot_type) {
178 if (bioset_integrity_create(bs, IBLOCK_BIO_POOL_SIZE) < 0) {
179 pr_err("Unable to allocate bioset for PI\n");
180 ret = -ENOMEM;
181 goto out_blkdev_put;
182 }
183 pr_debug("IBLOCK setup BIP bs->bio_integrity_pool: %p\n",
184 bs->bio_integrity_pool);
185 }
186 dev->dev_attrib.hw_pi_prot_type = dev->dev_attrib.pi_prot_type;
187 }
188
189 return 0;
190
191 out_blkdev_put:
192 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
193 out_free_bioset:
194 bioset_free(ib_dev->ibd_bio_set);
195 ib_dev->ibd_bio_set = NULL;
196 out:
197 return ret;
198 }
199
200 static void iblock_free_device(struct se_device *dev)
201 {
202 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
203
204 if (ib_dev->ibd_bd != NULL)
205 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
206 if (ib_dev->ibd_bio_set != NULL)
207 bioset_free(ib_dev->ibd_bio_set);
208
209 kfree(ib_dev);
210 }
211
212 static unsigned long long iblock_emulate_read_cap_with_block_size(
213 struct se_device *dev,
214 struct block_device *bd,
215 struct request_queue *q)
216 {
217 unsigned long long blocks_long = (div_u64(i_size_read(bd->bd_inode),
218 bdev_logical_block_size(bd)) - 1);
219 u32 block_size = bdev_logical_block_size(bd);
220
221 if (block_size == dev->dev_attrib.block_size)
222 return blocks_long;
223
224 switch (block_size) {
225 case 4096:
226 switch (dev->dev_attrib.block_size) {
227 case 2048:
228 blocks_long <<= 1;
229 break;
230 case 1024:
231 blocks_long <<= 2;
232 break;
233 case 512:
234 blocks_long <<= 3;
235 default:
236 break;
237 }
238 break;
239 case 2048:
240 switch (dev->dev_attrib.block_size) {
241 case 4096:
242 blocks_long >>= 1;
243 break;
244 case 1024:
245 blocks_long <<= 1;
246 break;
247 case 512:
248 blocks_long <<= 2;
249 break;
250 default:
251 break;
252 }
253 break;
254 case 1024:
255 switch (dev->dev_attrib.block_size) {
256 case 4096:
257 blocks_long >>= 2;
258 break;
259 case 2048:
260 blocks_long >>= 1;
261 break;
262 case 512:
263 blocks_long <<= 1;
264 break;
265 default:
266 break;
267 }
268 break;
269 case 512:
270 switch (dev->dev_attrib.block_size) {
271 case 4096:
272 blocks_long >>= 3;
273 break;
274 case 2048:
275 blocks_long >>= 2;
276 break;
277 case 1024:
278 blocks_long >>= 1;
279 break;
280 default:
281 break;
282 }
283 break;
284 default:
285 break;
286 }
287
288 return blocks_long;
289 }
290
291 static void iblock_complete_cmd(struct se_cmd *cmd)
292 {
293 struct iblock_req *ibr = cmd->priv;
294 u8 status;
295
296 if (!atomic_dec_and_test(&ibr->pending))
297 return;
298
299 if (atomic_read(&ibr->ib_bio_err_cnt))
300 status = SAM_STAT_CHECK_CONDITION;
301 else
302 status = SAM_STAT_GOOD;
303
304 target_complete_cmd(cmd, status);
305 kfree(ibr);
306 }
307
308 static void iblock_bio_done(struct bio *bio, int err)
309 {
310 struct se_cmd *cmd = bio->bi_private;
311 struct iblock_req *ibr = cmd->priv;
312
313 /*
314 * Set -EIO if !BIO_UPTODATE and the passed is still err=0
315 */
316 if (!test_bit(BIO_UPTODATE, &bio->bi_flags) && !err)
317 err = -EIO;
318
319 if (err != 0) {
320 pr_err("test_bit(BIO_UPTODATE) failed for bio: %p,"
321 " err: %d\n", bio, err);
322 /*
323 * Bump the ib_bio_err_cnt and release bio.
324 */
325 atomic_inc(&ibr->ib_bio_err_cnt);
326 smp_mb__after_atomic_inc();
327 }
328
329 bio_put(bio);
330
331 iblock_complete_cmd(cmd);
332 }
333
334 static struct bio *
335 iblock_get_bio(struct se_cmd *cmd, sector_t lba, u32 sg_num)
336 {
337 struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
338 struct bio *bio;
339
340 /*
341 * Only allocate as many vector entries as the bio code allows us to,
342 * we'll loop later on until we have handled the whole request.
343 */
344 if (sg_num > BIO_MAX_PAGES)
345 sg_num = BIO_MAX_PAGES;
346
347 bio = bio_alloc_bioset(GFP_NOIO, sg_num, ib_dev->ibd_bio_set);
348 if (!bio) {
349 pr_err("Unable to allocate memory for bio\n");
350 return NULL;
351 }
352
353 bio->bi_bdev = ib_dev->ibd_bd;
354 bio->bi_private = cmd;
355 bio->bi_end_io = &iblock_bio_done;
356 bio->bi_iter.bi_sector = lba;
357
358 return bio;
359 }
360
361 static void iblock_submit_bios(struct bio_list *list, int rw)
362 {
363 struct blk_plug plug;
364 struct bio *bio;
365
366 blk_start_plug(&plug);
367 while ((bio = bio_list_pop(list)))
368 submit_bio(rw, bio);
369 blk_finish_plug(&plug);
370 }
371
372 static void iblock_end_io_flush(struct bio *bio, int err)
373 {
374 struct se_cmd *cmd = bio->bi_private;
375
376 if (err)
377 pr_err("IBLOCK: cache flush failed: %d\n", err);
378
379 if (cmd) {
380 if (err)
381 target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
382 else
383 target_complete_cmd(cmd, SAM_STAT_GOOD);
384 }
385
386 bio_put(bio);
387 }
388
389 /*
390 * Implement SYCHRONIZE CACHE. Note that we can't handle lba ranges and must
391 * always flush the whole cache.
392 */
393 static sense_reason_t
394 iblock_execute_sync_cache(struct se_cmd *cmd)
395 {
396 struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
397 int immed = (cmd->t_task_cdb[1] & 0x2);
398 struct bio *bio;
399
400 /*
401 * If the Immediate bit is set, queue up the GOOD response
402 * for this SYNCHRONIZE_CACHE op.
403 */
404 if (immed)
405 target_complete_cmd(cmd, SAM_STAT_GOOD);
406
407 bio = bio_alloc(GFP_KERNEL, 0);
408 bio->bi_end_io = iblock_end_io_flush;
409 bio->bi_bdev = ib_dev->ibd_bd;
410 if (!immed)
411 bio->bi_private = cmd;
412 submit_bio(WRITE_FLUSH, bio);
413 return 0;
414 }
415
416 static sense_reason_t
417 iblock_do_unmap(struct se_cmd *cmd, void *priv,
418 sector_t lba, sector_t nolb)
419 {
420 struct block_device *bdev = priv;
421 int ret;
422
423 ret = blkdev_issue_discard(bdev, lba, nolb, GFP_KERNEL, 0);
424 if (ret < 0) {
425 pr_err("blkdev_issue_discard() failed: %d\n", ret);
426 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
427 }
428
429 return 0;
430 }
431
432 static sense_reason_t
433 iblock_execute_unmap(struct se_cmd *cmd)
434 {
435 struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
436
437 return sbc_execute_unmap(cmd, iblock_do_unmap, bdev);
438 }
439
440 static sense_reason_t
441 iblock_execute_write_same_unmap(struct se_cmd *cmd)
442 {
443 struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
444 sector_t lba = cmd->t_task_lba;
445 sector_t nolb = sbc_get_write_same_sectors(cmd);
446 int ret;
447
448 ret = iblock_do_unmap(cmd, bdev, lba, nolb);
449 if (ret)
450 return ret;
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 iblock_req *ibr;
460 struct scatterlist *sg;
461 struct bio *bio;
462 struct bio_list list;
463 sector_t block_lba = cmd->t_task_lba;
464 sector_t sectors = sbc_get_write_same_sectors(cmd);
465
466 sg = &cmd->t_data_sg[0];
467
468 if (cmd->t_data_nents > 1 ||
469 sg->length != cmd->se_dev->dev_attrib.block_size) {
470 pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
471 " block_size: %u\n", cmd->t_data_nents, sg->length,
472 cmd->se_dev->dev_attrib.block_size);
473 return TCM_INVALID_CDB_FIELD;
474 }
475
476 ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
477 if (!ibr)
478 goto fail;
479 cmd->priv = ibr;
480
481 bio = iblock_get_bio(cmd, block_lba, 1);
482 if (!bio)
483 goto fail_free_ibr;
484
485 bio_list_init(&list);
486 bio_list_add(&list, bio);
487
488 atomic_set(&ibr->pending, 1);
489
490 while (sectors) {
491 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
492 != sg->length) {
493
494 bio = iblock_get_bio(cmd, block_lba, 1);
495 if (!bio)
496 goto fail_put_bios;
497
498 atomic_inc(&ibr->pending);
499 bio_list_add(&list, bio);
500 }
501
502 /* Always in 512 byte units for Linux/Block */
503 block_lba += sg->length >> IBLOCK_LBA_SHIFT;
504 sectors -= 1;
505 }
506
507 iblock_submit_bios(&list, WRITE);
508 return 0;
509
510 fail_put_bios:
511 while ((bio = bio_list_pop(&list)))
512 bio_put(bio);
513 fail_free_ibr:
514 kfree(ibr);
515 fail:
516 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
517 }
518
519 enum {
520 Opt_udev_path, Opt_readonly, Opt_force, Opt_err
521 };
522
523 static match_table_t tokens = {
524 {Opt_udev_path, "udev_path=%s"},
525 {Opt_readonly, "readonly=%d"},
526 {Opt_force, "force=%d"},
527 {Opt_err, NULL}
528 };
529
530 static ssize_t iblock_set_configfs_dev_params(struct se_device *dev,
531 const char *page, ssize_t count)
532 {
533 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
534 char *orig, *ptr, *arg_p, *opts;
535 substring_t args[MAX_OPT_ARGS];
536 int ret = 0, token;
537 unsigned long tmp_readonly;
538
539 opts = kstrdup(page, GFP_KERNEL);
540 if (!opts)
541 return -ENOMEM;
542
543 orig = opts;
544
545 while ((ptr = strsep(&opts, ",\n")) != NULL) {
546 if (!*ptr)
547 continue;
548
549 token = match_token(ptr, tokens, args);
550 switch (token) {
551 case Opt_udev_path:
552 if (ib_dev->ibd_bd) {
553 pr_err("Unable to set udev_path= while"
554 " ib_dev->ibd_bd exists\n");
555 ret = -EEXIST;
556 goto out;
557 }
558 if (match_strlcpy(ib_dev->ibd_udev_path, &args[0],
559 SE_UDEV_PATH_LEN) == 0) {
560 ret = -EINVAL;
561 break;
562 }
563 pr_debug("IBLOCK: Referencing UDEV path: %s\n",
564 ib_dev->ibd_udev_path);
565 ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH;
566 break;
567 case Opt_readonly:
568 arg_p = match_strdup(&args[0]);
569 if (!arg_p) {
570 ret = -ENOMEM;
571 break;
572 }
573 ret = kstrtoul(arg_p, 0, &tmp_readonly);
574 kfree(arg_p);
575 if (ret < 0) {
576 pr_err("kstrtoul() failed for"
577 " readonly=\n");
578 goto out;
579 }
580 ib_dev->ibd_readonly = tmp_readonly;
581 pr_debug("IBLOCK: readonly: %d\n", ib_dev->ibd_readonly);
582 break;
583 case Opt_force:
584 break;
585 default:
586 break;
587 }
588 }
589
590 out:
591 kfree(orig);
592 return (!ret) ? count : ret;
593 }
594
595 static ssize_t iblock_show_configfs_dev_params(struct se_device *dev, char *b)
596 {
597 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
598 struct block_device *bd = ib_dev->ibd_bd;
599 char buf[BDEVNAME_SIZE];
600 ssize_t bl = 0;
601
602 if (bd)
603 bl += sprintf(b + bl, "iBlock device: %s",
604 bdevname(bd, buf));
605 if (ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)
606 bl += sprintf(b + bl, " UDEV PATH: %s",
607 ib_dev->ibd_udev_path);
608 bl += sprintf(b + bl, " readonly: %d\n", ib_dev->ibd_readonly);
609
610 bl += sprintf(b + bl, " ");
611 if (bd) {
612 bl += sprintf(b + bl, "Major: %d Minor: %d %s\n",
613 MAJOR(bd->bd_dev), MINOR(bd->bd_dev), (!bd->bd_contains) ?
614 "" : (bd->bd_holder == ib_dev) ?
615 "CLAIMED: IBLOCK" : "CLAIMED: OS");
616 } else {
617 bl += sprintf(b + bl, "Major: 0 Minor: 0\n");
618 }
619
620 return bl;
621 }
622
623 static int
624 iblock_alloc_bip(struct se_cmd *cmd, struct bio *bio)
625 {
626 struct se_device *dev = cmd->se_dev;
627 struct blk_integrity *bi;
628 struct bio_integrity_payload *bip;
629 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
630 struct scatterlist *sg;
631 int i, rc;
632
633 bi = bdev_get_integrity(ib_dev->ibd_bd);
634 if (!bi) {
635 pr_err("Unable to locate bio_integrity\n");
636 return -ENODEV;
637 }
638
639 bip = bio_integrity_alloc(bio, GFP_NOIO, cmd->t_prot_nents);
640 if (!bip) {
641 pr_err("Unable to allocate bio_integrity_payload\n");
642 return -ENOMEM;
643 }
644
645 bip->bip_iter.bi_size = (cmd->data_length / dev->dev_attrib.block_size) *
646 dev->prot_length;
647 bip->bip_iter.bi_sector = bio->bi_iter.bi_sector;
648
649 pr_debug("IBLOCK BIP Size: %u Sector: %llu\n", bip->bip_iter.bi_size,
650 (unsigned long long)bip->bip_iter.bi_sector);
651
652 for_each_sg(cmd->t_prot_sg, sg, cmd->t_prot_nents, i) {
653
654 rc = bio_integrity_add_page(bio, sg_page(sg), sg->length,
655 sg->offset);
656 if (rc != sg->length) {
657 pr_err("bio_integrity_add_page() failed; %d\n", rc);
658 return -ENOMEM;
659 }
660
661 pr_debug("Added bio integrity page: %p length: %d offset; %d\n",
662 sg_page(sg), sg->length, sg->offset);
663 }
664
665 return 0;
666 }
667
668 static sense_reason_t
669 iblock_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
670 enum dma_data_direction data_direction)
671 {
672 struct se_device *dev = cmd->se_dev;
673 struct iblock_req *ibr;
674 struct bio *bio, *bio_start;
675 struct bio_list list;
676 struct scatterlist *sg;
677 u32 sg_num = sgl_nents;
678 sector_t block_lba;
679 unsigned bio_cnt;
680 int rw = 0;
681 int i;
682
683 if (data_direction == DMA_TO_DEVICE) {
684 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
685 struct request_queue *q = bdev_get_queue(ib_dev->ibd_bd);
686 /*
687 * Force writethrough using WRITE_FUA if a volatile write cache
688 * is not enabled, or if initiator set the Force Unit Access bit.
689 */
690 if (q->flush_flags & REQ_FUA) {
691 if (cmd->se_cmd_flags & SCF_FUA)
692 rw = WRITE_FUA;
693 else if (!(q->flush_flags & REQ_FLUSH))
694 rw = WRITE_FUA;
695 else
696 rw = WRITE;
697 } else {
698 rw = WRITE;
699 }
700 } else {
701 rw = READ;
702 }
703
704 /*
705 * Convert the blocksize advertised to the initiator to the 512 byte
706 * units unconditionally used by the Linux block layer.
707 */
708 if (dev->dev_attrib.block_size == 4096)
709 block_lba = (cmd->t_task_lba << 3);
710 else if (dev->dev_attrib.block_size == 2048)
711 block_lba = (cmd->t_task_lba << 2);
712 else if (dev->dev_attrib.block_size == 1024)
713 block_lba = (cmd->t_task_lba << 1);
714 else if (dev->dev_attrib.block_size == 512)
715 block_lba = cmd->t_task_lba;
716 else {
717 pr_err("Unsupported SCSI -> BLOCK LBA conversion:"
718 " %u\n", dev->dev_attrib.block_size);
719 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
720 }
721
722 ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
723 if (!ibr)
724 goto fail;
725 cmd->priv = ibr;
726
727 if (!sgl_nents) {
728 atomic_set(&ibr->pending, 1);
729 iblock_complete_cmd(cmd);
730 return 0;
731 }
732
733 bio = iblock_get_bio(cmd, block_lba, sgl_nents);
734 if (!bio)
735 goto fail_free_ibr;
736
737 bio_start = bio;
738 bio_list_init(&list);
739 bio_list_add(&list, bio);
740
741 atomic_set(&ibr->pending, 2);
742 bio_cnt = 1;
743
744 for_each_sg(sgl, sg, sgl_nents, i) {
745 /*
746 * XXX: if the length the device accepts is shorter than the
747 * length of the S/G list entry this will cause and
748 * endless loop. Better hope no driver uses huge pages.
749 */
750 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
751 != sg->length) {
752 if (bio_cnt >= IBLOCK_MAX_BIO_PER_TASK) {
753 iblock_submit_bios(&list, rw);
754 bio_cnt = 0;
755 }
756
757 bio = iblock_get_bio(cmd, block_lba, sg_num);
758 if (!bio)
759 goto fail_put_bios;
760
761 atomic_inc(&ibr->pending);
762 bio_list_add(&list, bio);
763 bio_cnt++;
764 }
765
766 /* Always in 512 byte units for Linux/Block */
767 block_lba += sg->length >> IBLOCK_LBA_SHIFT;
768 sg_num--;
769 }
770
771 if (cmd->prot_type) {
772 int rc = iblock_alloc_bip(cmd, bio_start);
773 if (rc)
774 goto fail_put_bios;
775 }
776
777 iblock_submit_bios(&list, rw);
778 iblock_complete_cmd(cmd);
779 return 0;
780
781 fail_put_bios:
782 while ((bio = bio_list_pop(&list)))
783 bio_put(bio);
784 fail_free_ibr:
785 kfree(ibr);
786 fail:
787 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
788 }
789
790 static sector_t iblock_get_blocks(struct se_device *dev)
791 {
792 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
793 struct block_device *bd = ib_dev->ibd_bd;
794 struct request_queue *q = bdev_get_queue(bd);
795
796 return iblock_emulate_read_cap_with_block_size(dev, bd, q);
797 }
798
799 static sector_t iblock_get_alignment_offset_lbas(struct se_device *dev)
800 {
801 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
802 struct block_device *bd = ib_dev->ibd_bd;
803 int ret;
804
805 ret = bdev_alignment_offset(bd);
806 if (ret == -1)
807 return 0;
808
809 /* convert offset-bytes to offset-lbas */
810 return ret / bdev_logical_block_size(bd);
811 }
812
813 static unsigned int iblock_get_lbppbe(struct se_device *dev)
814 {
815 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
816 struct block_device *bd = ib_dev->ibd_bd;
817 int logs_per_phys = bdev_physical_block_size(bd) / bdev_logical_block_size(bd);
818
819 return ilog2(logs_per_phys);
820 }
821
822 static unsigned int iblock_get_io_min(struct se_device *dev)
823 {
824 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
825 struct block_device *bd = ib_dev->ibd_bd;
826
827 return bdev_io_min(bd);
828 }
829
830 static unsigned int iblock_get_io_opt(struct se_device *dev)
831 {
832 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
833 struct block_device *bd = ib_dev->ibd_bd;
834
835 return bdev_io_opt(bd);
836 }
837
838 static struct sbc_ops iblock_sbc_ops = {
839 .execute_rw = iblock_execute_rw,
840 .execute_sync_cache = iblock_execute_sync_cache,
841 .execute_write_same = iblock_execute_write_same,
842 .execute_write_same_unmap = iblock_execute_write_same_unmap,
843 .execute_unmap = iblock_execute_unmap,
844 };
845
846 static sense_reason_t
847 iblock_parse_cdb(struct se_cmd *cmd)
848 {
849 return sbc_parse_cdb(cmd, &iblock_sbc_ops);
850 }
851
852 static bool iblock_get_write_cache(struct se_device *dev)
853 {
854 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
855 struct block_device *bd = ib_dev->ibd_bd;
856 struct request_queue *q = bdev_get_queue(bd);
857
858 return q->flush_flags & REQ_FLUSH;
859 }
860
861 static struct se_subsystem_api iblock_template = {
862 .name = "iblock",
863 .inquiry_prod = "IBLOCK",
864 .inquiry_rev = IBLOCK_VERSION,
865 .owner = THIS_MODULE,
866 .transport_type = TRANSPORT_PLUGIN_VHBA_PDEV,
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 .free_device = iblock_free_device,
872 .parse_cdb = iblock_parse_cdb,
873 .set_configfs_dev_params = iblock_set_configfs_dev_params,
874 .show_configfs_dev_params = iblock_show_configfs_dev_params,
875 .get_device_type = sbc_get_device_type,
876 .get_blocks = iblock_get_blocks,
877 .get_alignment_offset_lbas = iblock_get_alignment_offset_lbas,
878 .get_lbppbe = iblock_get_lbppbe,
879 .get_io_min = iblock_get_io_min,
880 .get_io_opt = iblock_get_io_opt,
881 .get_write_cache = iblock_get_write_cache,
882 };
883
884 static int __init iblock_module_init(void)
885 {
886 return transport_subsystem_register(&iblock_template);
887 }
888
889 static void __exit iblock_module_exit(void)
890 {
891 transport_subsystem_release(&iblock_template);
892 }
893
894 MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin");
895 MODULE_AUTHOR("nab@Linux-iSCSI.org");
896 MODULE_LICENSE("GPL");
897
898 module_init(iblock_module_init);
899 module_exit(iblock_module_exit);
Linux with added FPC-III support