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
IBLOCK_DEV(struct se_device * dev)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
iblock_attach_hba(struct se_hba * hba,u32 host_id)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
iblock_detach_hba(struct se_hba * hba)63 static void iblock_detach_hba(struct se_hba *hba)
64 {
65 }
66
iblock_alloc_device(struct se_hba * hba,const char * name)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
iblock_configure_device(struct se_device * dev)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 if (target_configure_unmap_from_queue(&dev->dev_attrib, q))
125 pr_debug("IBLOCK: BLOCK Discard support available,"
126 " disabled by default\n");
127
128 /*
129 * Enable write same emulation for IBLOCK and use 0xFFFF as
130 * the smaller WRITE_SAME(10) only has a two-byte block count.
131 */
132 dev->dev_attrib.max_write_same_len = 0xFFFF;
133
134 if (blk_queue_nonrot(q))
135 dev->dev_attrib.is_nonrot = 1;
136
137 bi = bdev_get_integrity(bd);
138 if (bi) {
139 struct bio_set *bs = ib_dev->ibd_bio_set;
140
141 if (!strcmp(bi->profile->name, "T10-DIF-TYPE3-IP") ||
142 !strcmp(bi->profile->name, "T10-DIF-TYPE1-IP")) {
143 pr_err("IBLOCK export of blk_integrity: %s not"
144 " supported\n", bi->profile->name);
145 ret = -ENOSYS;
146 goto out_blkdev_put;
147 }
148
149 if (!strcmp(bi->profile->name, "T10-DIF-TYPE3-CRC")) {
150 dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE3_PROT;
151 } else if (!strcmp(bi->profile->name, "T10-DIF-TYPE1-CRC")) {
152 dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE1_PROT;
153 }
154
155 if (dev->dev_attrib.pi_prot_type) {
156 if (bioset_integrity_create(bs, IBLOCK_BIO_POOL_SIZE) < 0) {
157 pr_err("Unable to allocate bioset for PI\n");
158 ret = -ENOMEM;
159 goto out_blkdev_put;
160 }
161 pr_debug("IBLOCK setup BIP bs->bio_integrity_pool: %p\n",
162 bs->bio_integrity_pool);
163 }
164 dev->dev_attrib.hw_pi_prot_type = dev->dev_attrib.pi_prot_type;
165 }
166
167 return 0;
168
169 out_blkdev_put:
170 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
171 out_free_bioset:
172 bioset_free(ib_dev->ibd_bio_set);
173 ib_dev->ibd_bio_set = NULL;
174 out:
175 return ret;
176 }
177
iblock_dev_call_rcu(struct rcu_head * p)178 static void iblock_dev_call_rcu(struct rcu_head *p)
179 {
180 struct se_device *dev = container_of(p, struct se_device, rcu_head);
181 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
182
183 kfree(ib_dev);
184 }
185
iblock_free_device(struct se_device * dev)186 static void iblock_free_device(struct se_device *dev)
187 {
188 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
189
190 if (ib_dev->ibd_bd != NULL)
191 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
192 if (ib_dev->ibd_bio_set != NULL)
193 bioset_free(ib_dev->ibd_bio_set);
194
195 call_rcu(&dev->rcu_head, iblock_dev_call_rcu);
196 }
197
iblock_emulate_read_cap_with_block_size(struct se_device * dev,struct block_device * bd,struct request_queue * q)198 static unsigned long long iblock_emulate_read_cap_with_block_size(
199 struct se_device *dev,
200 struct block_device *bd,
201 struct request_queue *q)
202 {
203 unsigned long long blocks_long = (div_u64(i_size_read(bd->bd_inode),
204 bdev_logical_block_size(bd)) - 1);
205 u32 block_size = bdev_logical_block_size(bd);
206
207 if (block_size == dev->dev_attrib.block_size)
208 return blocks_long;
209
210 switch (block_size) {
211 case 4096:
212 switch (dev->dev_attrib.block_size) {
213 case 2048:
214 blocks_long <<= 1;
215 break;
216 case 1024:
217 blocks_long <<= 2;
218 break;
219 case 512:
220 blocks_long <<= 3;
221 default:
222 break;
223 }
224 break;
225 case 2048:
226 switch (dev->dev_attrib.block_size) {
227 case 4096:
228 blocks_long >>= 1;
229 break;
230 case 1024:
231 blocks_long <<= 1;
232 break;
233 case 512:
234 blocks_long <<= 2;
235 break;
236 default:
237 break;
238 }
239 break;
240 case 1024:
241 switch (dev->dev_attrib.block_size) {
242 case 4096:
243 blocks_long >>= 2;
244 break;
245 case 2048:
246 blocks_long >>= 1;
247 break;
248 case 512:
249 blocks_long <<= 1;
250 break;
251 default:
252 break;
253 }
254 break;
255 case 512:
256 switch (dev->dev_attrib.block_size) {
257 case 4096:
258 blocks_long >>= 3;
259 break;
260 case 2048:
261 blocks_long >>= 2;
262 break;
263 case 1024:
264 blocks_long >>= 1;
265 break;
266 default:
267 break;
268 }
269 break;
270 default:
271 break;
272 }
273
274 return blocks_long;
275 }
276
iblock_complete_cmd(struct se_cmd * cmd)277 static void iblock_complete_cmd(struct se_cmd *cmd)
278 {
279 struct iblock_req *ibr = cmd->priv;
280 u8 status;
281
282 if (!atomic_dec_and_test(&ibr->pending))
283 return;
284
285 if (atomic_read(&ibr->ib_bio_err_cnt))
286 status = SAM_STAT_CHECK_CONDITION;
287 else
288 status = SAM_STAT_GOOD;
289
290 target_complete_cmd(cmd, status);
291 kfree(ibr);
292 }
293
iblock_bio_done(struct bio * bio)294 static void iblock_bio_done(struct bio *bio)
295 {
296 struct se_cmd *cmd = bio->bi_private;
297 struct iblock_req *ibr = cmd->priv;
298
299 if (bio->bi_error) {
300 pr_err("bio error: %p, err: %d\n", bio, bio->bi_error);
301 /*
302 * Bump the ib_bio_err_cnt and release bio.
303 */
304 atomic_inc(&ibr->ib_bio_err_cnt);
305 smp_mb__after_atomic();
306 }
307
308 bio_put(bio);
309
310 iblock_complete_cmd(cmd);
311 }
312
313 static struct bio *
iblock_get_bio(struct se_cmd * cmd,sector_t lba,u32 sg_num)314 iblock_get_bio(struct se_cmd *cmd, sector_t lba, u32 sg_num)
315 {
316 struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
317 struct bio *bio;
318
319 /*
320 * Only allocate as many vector entries as the bio code allows us to,
321 * we'll loop later on until we have handled the whole request.
322 */
323 if (sg_num > BIO_MAX_PAGES)
324 sg_num = BIO_MAX_PAGES;
325
326 bio = bio_alloc_bioset(GFP_NOIO, sg_num, ib_dev->ibd_bio_set);
327 if (!bio) {
328 pr_err("Unable to allocate memory for bio\n");
329 return NULL;
330 }
331
332 bio->bi_bdev = ib_dev->ibd_bd;
333 bio->bi_private = cmd;
334 bio->bi_end_io = &iblock_bio_done;
335 bio->bi_iter.bi_sector = lba;
336
337 return bio;
338 }
339
iblock_submit_bios(struct bio_list * list,int rw)340 static void iblock_submit_bios(struct bio_list *list, int rw)
341 {
342 struct blk_plug plug;
343 struct bio *bio;
344
345 blk_start_plug(&plug);
346 while ((bio = bio_list_pop(list)))
347 submit_bio(rw, bio);
348 blk_finish_plug(&plug);
349 }
350
iblock_end_io_flush(struct bio * bio)351 static void iblock_end_io_flush(struct bio *bio)
352 {
353 struct se_cmd *cmd = bio->bi_private;
354
355 if (bio->bi_error)
356 pr_err("IBLOCK: cache flush failed: %d\n", bio->bi_error);
357
358 if (cmd) {
359 if (bio->bi_error)
360 target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
361 else
362 target_complete_cmd(cmd, SAM_STAT_GOOD);
363 }
364
365 bio_put(bio);
366 }
367
368 /*
369 * Implement SYCHRONIZE CACHE. Note that we can't handle lba ranges and must
370 * always flush the whole cache.
371 */
372 static sense_reason_t
iblock_execute_sync_cache(struct se_cmd * cmd)373 iblock_execute_sync_cache(struct se_cmd *cmd)
374 {
375 struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
376 int immed = (cmd->t_task_cdb[1] & 0x2);
377 struct bio *bio;
378
379 /*
380 * If the Immediate bit is set, queue up the GOOD response
381 * for this SYNCHRONIZE_CACHE op.
382 */
383 if (immed)
384 target_complete_cmd(cmd, SAM_STAT_GOOD);
385
386 bio = bio_alloc(GFP_KERNEL, 0);
387 bio->bi_end_io = iblock_end_io_flush;
388 bio->bi_bdev = ib_dev->ibd_bd;
389 if (!immed)
390 bio->bi_private = cmd;
391 submit_bio(WRITE_FLUSH, bio);
392 return 0;
393 }
394
395 static sense_reason_t
iblock_execute_unmap(struct se_cmd * cmd,sector_t lba,sector_t nolb)396 iblock_execute_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
397 {
398 struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
399 struct se_device *dev = cmd->se_dev;
400 int ret;
401
402 ret = blkdev_issue_discard(bdev,
403 target_to_linux_sector(dev, lba),
404 target_to_linux_sector(dev, nolb),
405 GFP_KERNEL, 0);
406 if (ret < 0) {
407 pr_err("blkdev_issue_discard() failed: %d\n", ret);
408 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
409 }
410
411 return 0;
412 }
413
414 static sense_reason_t
iblock_execute_write_same(struct se_cmd * cmd)415 iblock_execute_write_same(struct se_cmd *cmd)
416 {
417 struct iblock_req *ibr;
418 struct scatterlist *sg;
419 struct bio *bio;
420 struct bio_list list;
421 struct se_device *dev = cmd->se_dev;
422 sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba);
423 sector_t sectors = target_to_linux_sector(dev,
424 sbc_get_write_same_sectors(cmd));
425
426 if (cmd->prot_op) {
427 pr_err("WRITE_SAME: Protection information with IBLOCK"
428 " backends not supported\n");
429 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
430 }
431 sg = &cmd->t_data_sg[0];
432
433 if (cmd->t_data_nents > 1 ||
434 sg->length != cmd->se_dev->dev_attrib.block_size) {
435 pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
436 " block_size: %u\n", cmd->t_data_nents, sg->length,
437 cmd->se_dev->dev_attrib.block_size);
438 return TCM_INVALID_CDB_FIELD;
439 }
440
441 ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
442 if (!ibr)
443 goto fail;
444 cmd->priv = ibr;
445
446 bio = iblock_get_bio(cmd, block_lba, 1);
447 if (!bio)
448 goto fail_free_ibr;
449
450 bio_list_init(&list);
451 bio_list_add(&list, bio);
452
453 atomic_set(&ibr->pending, 1);
454
455 while (sectors) {
456 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
457 != sg->length) {
458
459 bio = iblock_get_bio(cmd, block_lba, 1);
460 if (!bio)
461 goto fail_put_bios;
462
463 atomic_inc(&ibr->pending);
464 bio_list_add(&list, bio);
465 }
466
467 /* Always in 512 byte units for Linux/Block */
468 block_lba += sg->length >> IBLOCK_LBA_SHIFT;
469 sectors -= 1;
470 }
471
472 iblock_submit_bios(&list, WRITE);
473 return 0;
474
475 fail_put_bios:
476 while ((bio = bio_list_pop(&list)))
477 bio_put(bio);
478 fail_free_ibr:
479 kfree(ibr);
480 fail:
481 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
482 }
483
484 enum {
485 Opt_udev_path, Opt_readonly, Opt_force, Opt_err
486 };
487
488 static match_table_t tokens = {
489 {Opt_udev_path, "udev_path=%s"},
490 {Opt_readonly, "readonly=%d"},
491 {Opt_force, "force=%d"},
492 {Opt_err, NULL}
493 };
494
iblock_set_configfs_dev_params(struct se_device * dev,const char * page,ssize_t count)495 static ssize_t iblock_set_configfs_dev_params(struct se_device *dev,
496 const char *page, ssize_t count)
497 {
498 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
499 char *orig, *ptr, *arg_p, *opts;
500 substring_t args[MAX_OPT_ARGS];
501 int ret = 0, token;
502 unsigned long tmp_readonly;
503
504 opts = kstrdup(page, GFP_KERNEL);
505 if (!opts)
506 return -ENOMEM;
507
508 orig = opts;
509
510 while ((ptr = strsep(&opts, ",\n")) != NULL) {
511 if (!*ptr)
512 continue;
513
514 token = match_token(ptr, tokens, args);
515 switch (token) {
516 case Opt_udev_path:
517 if (ib_dev->ibd_bd) {
518 pr_err("Unable to set udev_path= while"
519 " ib_dev->ibd_bd exists\n");
520 ret = -EEXIST;
521 goto out;
522 }
523 if (match_strlcpy(ib_dev->ibd_udev_path, &args[0],
524 SE_UDEV_PATH_LEN) == 0) {
525 ret = -EINVAL;
526 break;
527 }
528 pr_debug("IBLOCK: Referencing UDEV path: %s\n",
529 ib_dev->ibd_udev_path);
530 ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH;
531 break;
532 case Opt_readonly:
533 arg_p = match_strdup(&args[0]);
534 if (!arg_p) {
535 ret = -ENOMEM;
536 break;
537 }
538 ret = kstrtoul(arg_p, 0, &tmp_readonly);
539 kfree(arg_p);
540 if (ret < 0) {
541 pr_err("kstrtoul() failed for"
542 " readonly=\n");
543 goto out;
544 }
545 ib_dev->ibd_readonly = tmp_readonly;
546 pr_debug("IBLOCK: readonly: %d\n", ib_dev->ibd_readonly);
547 break;
548 case Opt_force:
549 break;
550 default:
551 break;
552 }
553 }
554
555 out:
556 kfree(orig);
557 return (!ret) ? count : ret;
558 }
559
iblock_show_configfs_dev_params(struct se_device * dev,char * b)560 static ssize_t iblock_show_configfs_dev_params(struct se_device *dev, char *b)
561 {
562 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
563 struct block_device *bd = ib_dev->ibd_bd;
564 char buf[BDEVNAME_SIZE];
565 ssize_t bl = 0;
566
567 if (bd)
568 bl += sprintf(b + bl, "iBlock device: %s",
569 bdevname(bd, buf));
570 if (ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)
571 bl += sprintf(b + bl, " UDEV PATH: %s",
572 ib_dev->ibd_udev_path);
573 bl += sprintf(b + bl, " readonly: %d\n", ib_dev->ibd_readonly);
574
575 bl += sprintf(b + bl, " ");
576 if (bd) {
577 bl += sprintf(b + bl, "Major: %d Minor: %d %s\n",
578 MAJOR(bd->bd_dev), MINOR(bd->bd_dev), (!bd->bd_contains) ?
579 "" : (bd->bd_holder == ib_dev) ?
580 "CLAIMED: IBLOCK" : "CLAIMED: OS");
581 } else {
582 bl += sprintf(b + bl, "Major: 0 Minor: 0\n");
583 }
584
585 return bl;
586 }
587
588 static int
iblock_alloc_bip(struct se_cmd * cmd,struct bio * bio)589 iblock_alloc_bip(struct se_cmd *cmd, struct bio *bio)
590 {
591 struct se_device *dev = cmd->se_dev;
592 struct blk_integrity *bi;
593 struct bio_integrity_payload *bip;
594 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
595 struct scatterlist *sg;
596 int i, rc;
597
598 bi = bdev_get_integrity(ib_dev->ibd_bd);
599 if (!bi) {
600 pr_err("Unable to locate bio_integrity\n");
601 return -ENODEV;
602 }
603
604 bip = bio_integrity_alloc(bio, GFP_NOIO, cmd->t_prot_nents);
605 if (!bip) {
606 pr_err("Unable to allocate bio_integrity_payload\n");
607 return -ENOMEM;
608 }
609
610 bip->bip_iter.bi_size = (cmd->data_length / dev->dev_attrib.block_size) *
611 dev->prot_length;
612 bip->bip_iter.bi_sector = bio->bi_iter.bi_sector;
613
614 pr_debug("IBLOCK BIP Size: %u Sector: %llu\n", bip->bip_iter.bi_size,
615 (unsigned long long)bip->bip_iter.bi_sector);
616
617 for_each_sg(cmd->t_prot_sg, sg, cmd->t_prot_nents, i) {
618
619 rc = bio_integrity_add_page(bio, sg_page(sg), sg->length,
620 sg->offset);
621 if (rc != sg->length) {
622 pr_err("bio_integrity_add_page() failed; %d\n", rc);
623 return -ENOMEM;
624 }
625
626 pr_debug("Added bio integrity page: %p length: %d offset; %d\n",
627 sg_page(sg), sg->length, sg->offset);
628 }
629
630 return 0;
631 }
632
633 static sense_reason_t
iblock_execute_rw(struct se_cmd * cmd,struct scatterlist * sgl,u32 sgl_nents,enum dma_data_direction data_direction)634 iblock_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
635 enum dma_data_direction data_direction)
636 {
637 struct se_device *dev = cmd->se_dev;
638 sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba);
639 struct iblock_req *ibr;
640 struct bio *bio, *bio_start;
641 struct bio_list list;
642 struct scatterlist *sg;
643 u32 sg_num = sgl_nents;
644 unsigned bio_cnt;
645 int rw = 0;
646 int i;
647
648 if (data_direction == DMA_TO_DEVICE) {
649 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
650 struct request_queue *q = bdev_get_queue(ib_dev->ibd_bd);
651 /*
652 * Force writethrough using WRITE_FUA if a volatile write cache
653 * is not enabled, or if initiator set the Force Unit Access bit.
654 */
655 if (q->flush_flags & REQ_FUA) {
656 if (cmd->se_cmd_flags & SCF_FUA)
657 rw = WRITE_FUA;
658 else if (!(q->flush_flags & REQ_FLUSH))
659 rw = WRITE_FUA;
660 else
661 rw = WRITE;
662 } else {
663 rw = WRITE;
664 }
665 } else {
666 rw = READ;
667 }
668
669 ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
670 if (!ibr)
671 goto fail;
672 cmd->priv = ibr;
673
674 if (!sgl_nents) {
675 atomic_set(&ibr->pending, 1);
676 iblock_complete_cmd(cmd);
677 return 0;
678 }
679
680 bio = iblock_get_bio(cmd, block_lba, sgl_nents);
681 if (!bio)
682 goto fail_free_ibr;
683
684 bio_start = bio;
685 bio_list_init(&list);
686 bio_list_add(&list, bio);
687
688 atomic_set(&ibr->pending, 2);
689 bio_cnt = 1;
690
691 for_each_sg(sgl, sg, sgl_nents, i) {
692 /*
693 * XXX: if the length the device accepts is shorter than the
694 * length of the S/G list entry this will cause and
695 * endless loop. Better hope no driver uses huge pages.
696 */
697 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
698 != sg->length) {
699 if (bio_cnt >= IBLOCK_MAX_BIO_PER_TASK) {
700 iblock_submit_bios(&list, rw);
701 bio_cnt = 0;
702 }
703
704 bio = iblock_get_bio(cmd, block_lba, sg_num);
705 if (!bio)
706 goto fail_put_bios;
707
708 atomic_inc(&ibr->pending);
709 bio_list_add(&list, bio);
710 bio_cnt++;
711 }
712
713 /* Always in 512 byte units for Linux/Block */
714 block_lba += sg->length >> IBLOCK_LBA_SHIFT;
715 sg_num--;
716 }
717
718 if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
719 int rc = iblock_alloc_bip(cmd, bio_start);
720 if (rc)
721 goto fail_put_bios;
722 }
723
724 iblock_submit_bios(&list, rw);
725 iblock_complete_cmd(cmd);
726 return 0;
727
728 fail_put_bios:
729 while ((bio = bio_list_pop(&list)))
730 bio_put(bio);
731 fail_free_ibr:
732 kfree(ibr);
733 fail:
734 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
735 }
736
iblock_get_blocks(struct se_device * dev)737 static sector_t iblock_get_blocks(struct se_device *dev)
738 {
739 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
740 struct block_device *bd = ib_dev->ibd_bd;
741 struct request_queue *q = bdev_get_queue(bd);
742
743 return iblock_emulate_read_cap_with_block_size(dev, bd, q);
744 }
745
iblock_get_alignment_offset_lbas(struct se_device * dev)746 static sector_t iblock_get_alignment_offset_lbas(struct se_device *dev)
747 {
748 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
749 struct block_device *bd = ib_dev->ibd_bd;
750 int ret;
751
752 ret = bdev_alignment_offset(bd);
753 if (ret == -1)
754 return 0;
755
756 /* convert offset-bytes to offset-lbas */
757 return ret / bdev_logical_block_size(bd);
758 }
759
iblock_get_lbppbe(struct se_device * dev)760 static unsigned int iblock_get_lbppbe(struct se_device *dev)
761 {
762 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
763 struct block_device *bd = ib_dev->ibd_bd;
764 int logs_per_phys = bdev_physical_block_size(bd) / bdev_logical_block_size(bd);
765
766 return ilog2(logs_per_phys);
767 }
768
iblock_get_io_min(struct se_device * dev)769 static unsigned int iblock_get_io_min(struct se_device *dev)
770 {
771 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
772 struct block_device *bd = ib_dev->ibd_bd;
773
774 return bdev_io_min(bd);
775 }
776
iblock_get_io_opt(struct se_device * dev)777 static unsigned int iblock_get_io_opt(struct se_device *dev)
778 {
779 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
780 struct block_device *bd = ib_dev->ibd_bd;
781
782 return bdev_io_opt(bd);
783 }
784
785 static struct sbc_ops iblock_sbc_ops = {
786 .execute_rw = iblock_execute_rw,
787 .execute_sync_cache = iblock_execute_sync_cache,
788 .execute_write_same = iblock_execute_write_same,
789 .execute_unmap = iblock_execute_unmap,
790 };
791
792 static sense_reason_t
iblock_parse_cdb(struct se_cmd * cmd)793 iblock_parse_cdb(struct se_cmd *cmd)
794 {
795 return sbc_parse_cdb(cmd, &iblock_sbc_ops);
796 }
797
iblock_get_write_cache(struct se_device * dev)798 static bool iblock_get_write_cache(struct se_device *dev)
799 {
800 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
801 struct block_device *bd = ib_dev->ibd_bd;
802 struct request_queue *q = bdev_get_queue(bd);
803
804 return q->flush_flags & REQ_FLUSH;
805 }
806
807 static const struct target_backend_ops iblock_ops = {
808 .name = "iblock",
809 .inquiry_prod = "IBLOCK",
810 .inquiry_rev = IBLOCK_VERSION,
811 .owner = THIS_MODULE,
812 .attach_hba = iblock_attach_hba,
813 .detach_hba = iblock_detach_hba,
814 .alloc_device = iblock_alloc_device,
815 .configure_device = iblock_configure_device,
816 .free_device = iblock_free_device,
817 .parse_cdb = iblock_parse_cdb,
818 .set_configfs_dev_params = iblock_set_configfs_dev_params,
819 .show_configfs_dev_params = iblock_show_configfs_dev_params,
820 .get_device_type = sbc_get_device_type,
821 .get_blocks = iblock_get_blocks,
822 .get_alignment_offset_lbas = iblock_get_alignment_offset_lbas,
823 .get_lbppbe = iblock_get_lbppbe,
824 .get_io_min = iblock_get_io_min,
825 .get_io_opt = iblock_get_io_opt,
826 .get_write_cache = iblock_get_write_cache,
827 .tb_dev_attrib_attrs = sbc_attrib_attrs,
828 };
829
iblock_module_init(void)830 static int __init iblock_module_init(void)
831 {
832 return transport_backend_register(&iblock_ops);
833 }
834
iblock_module_exit(void)835 static void __exit iblock_module_exit(void)
836 {
837 target_backend_unregister(&iblock_ops);
838 }
839
840 MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin");
841 MODULE_AUTHOR("nab@Linux-iSCSI.org");
842 MODULE_LICENSE("GPL");
843
844 module_init(iblock_module_init);
845 module_exit(iblock_module_exit);
846