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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
49static inline struct iblock_dev *IBLOCK_DEV(struct se_device *dev)
50{
51 return container_of(dev, struct iblock_dev, dev);
52}
53
54
55static 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
63static void iblock_detach_hba(struct se_hba *hba)
64{
65}
66
67static 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
82static 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
169out_blkdev_put:
170 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
171out_free_bioset:
172 bioset_free(ib_dev->ibd_bio_set);
173 ib_dev->ibd_bio_set = NULL;
174out:
175 return ret;
176}
177
178static 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
186static 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
198static 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
277static 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
294static 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
313static struct bio *
314iblock_get_bio(struct se_cmd *cmd, sector_t lba, u32 sg_num, int op,
315 int op_flags)
316{
317 struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
318 struct bio *bio;
319
320 /*
321 * Only allocate as many vector entries as the bio code allows us to,
322 * we'll loop later on until we have handled the whole request.
323 */
324 if (sg_num > BIO_MAX_PAGES)
325 sg_num = BIO_MAX_PAGES;
326
327 bio = bio_alloc_bioset(GFP_NOIO, sg_num, ib_dev->ibd_bio_set);
328 if (!bio) {
329 pr_err("Unable to allocate memory for bio\n");
330 return NULL;
331 }
332
333 bio->bi_bdev = ib_dev->ibd_bd;
334 bio->bi_private = cmd;
335 bio->bi_end_io = &iblock_bio_done;
336 bio->bi_iter.bi_sector = lba;
337 bio_set_op_attrs(bio, op, op_flags);
338
339 return bio;
340}
341
342static void iblock_submit_bios(struct bio_list *list)
343{
344 struct blk_plug plug;
345 struct bio *bio;
346
347 blk_start_plug(&plug);
348 while ((bio = bio_list_pop(list)))
349 submit_bio(bio);
350 blk_finish_plug(&plug);
351}
352
353static void iblock_end_io_flush(struct bio *bio)
354{
355 struct se_cmd *cmd = bio->bi_private;
356
357 if (bio->bi_error)
358 pr_err("IBLOCK: cache flush failed: %d\n", bio->bi_error);
359
360 if (cmd) {
361 if (bio->bi_error)
362 target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
363 else
364 target_complete_cmd(cmd, SAM_STAT_GOOD);
365 }
366
367 bio_put(bio);
368}
369
370/*
371 * Implement SYCHRONIZE CACHE. Note that we can't handle lba ranges and must
372 * always flush the whole cache.
373 */
374static sense_reason_t
375iblock_execute_sync_cache(struct se_cmd *cmd)
376{
377 struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
378 int immed = (cmd->t_task_cdb[1] & 0x2);
379 struct bio *bio;
380
381 /*
382 * If the Immediate bit is set, queue up the GOOD response
383 * for this SYNCHRONIZE_CACHE op.
384 */
385 if (immed)
386 target_complete_cmd(cmd, SAM_STAT_GOOD);
387
388 bio = bio_alloc(GFP_KERNEL, 0);
389 bio->bi_end_io = iblock_end_io_flush;
390 bio->bi_bdev = ib_dev->ibd_bd;
391 bio->bi_opf = REQ_OP_WRITE | REQ_PREFLUSH;
392 if (!immed)
393 bio->bi_private = cmd;
394 submit_bio(bio);
395 return 0;
396}
397
398static sense_reason_t
399iblock_execute_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
400{
401 struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
402 struct se_device *dev = cmd->se_dev;
403 int ret;
404
405 ret = blkdev_issue_discard(bdev,
406 target_to_linux_sector(dev, lba),
407 target_to_linux_sector(dev, nolb),
408 GFP_KERNEL, 0);
409 if (ret < 0) {
410 pr_err("blkdev_issue_discard() failed: %d\n", ret);
411 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
412 }
413
414 return 0;
415}
416
417static sense_reason_t
418iblock_execute_write_same_direct(struct block_device *bdev, struct se_cmd *cmd)
419{
420 struct se_device *dev = cmd->se_dev;
421 struct scatterlist *sg = &cmd->t_data_sg[0];
422 struct page *page = NULL;
423 int ret;
424
425 if (sg->offset) {
426 page = alloc_page(GFP_KERNEL);
427 if (!page)
428 return TCM_OUT_OF_RESOURCES;
429 sg_copy_to_buffer(sg, cmd->t_data_nents, page_address(page),
430 dev->dev_attrib.block_size);
431 }
432
433 ret = blkdev_issue_write_same(bdev,
434 target_to_linux_sector(dev, cmd->t_task_lba),
435 target_to_linux_sector(dev,
436 sbc_get_write_same_sectors(cmd)),
437 GFP_KERNEL, page ? page : sg_page(sg));
438 if (page)
439 __free_page(page);
440 if (ret)
441 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
442
443 target_complete_cmd(cmd, GOOD);
444 return 0;
445}
446
447static sense_reason_t
448iblock_execute_write_same(struct se_cmd *cmd)
449{
450 struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
451 struct iblock_req *ibr;
452 struct scatterlist *sg;
453 struct bio *bio;
454 struct bio_list list;
455 struct se_device *dev = cmd->se_dev;
456 sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba);
457 sector_t sectors = target_to_linux_sector(dev,
458 sbc_get_write_same_sectors(cmd));
459
460 if (cmd->prot_op) {
461 pr_err("WRITE_SAME: Protection information with IBLOCK"
462 " backends not supported\n");
463 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
464 }
465 sg = &cmd->t_data_sg[0];
466
467 if (cmd->t_data_nents > 1 ||
468 sg->length != cmd->se_dev->dev_attrib.block_size) {
469 pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
470 " block_size: %u\n", cmd->t_data_nents, sg->length,
471 cmd->se_dev->dev_attrib.block_size);
472 return TCM_INVALID_CDB_FIELD;
473 }
474
475 if (bdev_write_same(bdev))
476 return iblock_execute_write_same_direct(bdev, cmd);
477
478 ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
479 if (!ibr)
480 goto fail;
481 cmd->priv = ibr;
482
483 bio = iblock_get_bio(cmd, block_lba, 1, REQ_OP_WRITE, 0);
484 if (!bio)
485 goto fail_free_ibr;
486
487 bio_list_init(&list);
488 bio_list_add(&list, bio);
489
490 atomic_set(&ibr->pending, 1);
491
492 while (sectors) {
493 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
494 != sg->length) {
495
496 bio = iblock_get_bio(cmd, block_lba, 1, REQ_OP_WRITE,
497 0);
498 if (!bio)
499 goto fail_put_bios;
500
501 atomic_inc(&ibr->pending);
502 bio_list_add(&list, bio);
503 }
504
505 /* Always in 512 byte units for Linux/Block */
506 block_lba += sg->length >> IBLOCK_LBA_SHIFT;
507 sectors -= 1;
508 }
509
510 iblock_submit_bios(&list);
511 return 0;
512
513fail_put_bios:
514 while ((bio = bio_list_pop(&list)))
515 bio_put(bio);
516fail_free_ibr:
517 kfree(ibr);
518fail:
519 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
520}
521
522enum {
523 Opt_udev_path, Opt_readonly, Opt_force, Opt_err
524};
525
526static match_table_t tokens = {
527 {Opt_udev_path, "udev_path=%s"},
528 {Opt_readonly, "readonly=%d"},
529 {Opt_force, "force=%d"},
530 {Opt_err, NULL}
531};
532
533static ssize_t iblock_set_configfs_dev_params(struct se_device *dev,
534 const char *page, ssize_t count)
535{
536 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
537 char *orig, *ptr, *arg_p, *opts;
538 substring_t args[MAX_OPT_ARGS];
539 int ret = 0, token;
540 unsigned long tmp_readonly;
541
542 opts = kstrdup(page, GFP_KERNEL);
543 if (!opts)
544 return -ENOMEM;
545
546 orig = opts;
547
548 while ((ptr = strsep(&opts, ",\n")) != NULL) {
549 if (!*ptr)
550 continue;
551
552 token = match_token(ptr, tokens, args);
553 switch (token) {
554 case Opt_udev_path:
555 if (ib_dev->ibd_bd) {
556 pr_err("Unable to set udev_path= while"
557 " ib_dev->ibd_bd exists\n");
558 ret = -EEXIST;
559 goto out;
560 }
561 if (match_strlcpy(ib_dev->ibd_udev_path, &args[0],
562 SE_UDEV_PATH_LEN) == 0) {
563 ret = -EINVAL;
564 break;
565 }
566 pr_debug("IBLOCK: Referencing UDEV path: %s\n",
567 ib_dev->ibd_udev_path);
568 ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH;
569 break;
570 case Opt_readonly:
571 arg_p = match_strdup(&args[0]);
572 if (!arg_p) {
573 ret = -ENOMEM;
574 break;
575 }
576 ret = kstrtoul(arg_p, 0, &tmp_readonly);
577 kfree(arg_p);
578 if (ret < 0) {
579 pr_err("kstrtoul() failed for"
580 " readonly=\n");
581 goto out;
582 }
583 ib_dev->ibd_readonly = tmp_readonly;
584 pr_debug("IBLOCK: readonly: %d\n", ib_dev->ibd_readonly);
585 break;
586 case Opt_force:
587 break;
588 default:
589 break;
590 }
591 }
592
593out:
594 kfree(orig);
595 return (!ret) ? count : ret;
596}
597
598static ssize_t iblock_show_configfs_dev_params(struct se_device *dev, char *b)
599{
600 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
601 struct block_device *bd = ib_dev->ibd_bd;
602 char buf[BDEVNAME_SIZE];
603 ssize_t bl = 0;
604
605 if (bd)
606 bl += sprintf(b + bl, "iBlock device: %s",
607 bdevname(bd, buf));
608 if (ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)
609 bl += sprintf(b + bl, " UDEV PATH: %s",
610 ib_dev->ibd_udev_path);
611 bl += sprintf(b + bl, " readonly: %d\n", ib_dev->ibd_readonly);
612
613 bl += sprintf(b + bl, " ");
614 if (bd) {
615 bl += sprintf(b + bl, "Major: %d Minor: %d %s\n",
616 MAJOR(bd->bd_dev), MINOR(bd->bd_dev), (!bd->bd_contains) ?
617 "" : (bd->bd_holder == ib_dev) ?
618 "CLAIMED: IBLOCK" : "CLAIMED: OS");
619 } else {
620 bl += sprintf(b + bl, "Major: 0 Minor: 0\n");
621 }
622
623 return bl;
624}
625
626static int
627iblock_alloc_bip(struct se_cmd *cmd, struct bio *bio)
628{
629 struct se_device *dev = cmd->se_dev;
630 struct blk_integrity *bi;
631 struct bio_integrity_payload *bip;
632 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
633 struct scatterlist *sg;
634 int i, rc;
635
636 bi = bdev_get_integrity(ib_dev->ibd_bd);
637 if (!bi) {
638 pr_err("Unable to locate bio_integrity\n");
639 return -ENODEV;
640 }
641
642 bip = bio_integrity_alloc(bio, GFP_NOIO, cmd->t_prot_nents);
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 = (cmd->data_length / dev->dev_attrib.block_size) *
649 dev->prot_length;
650 bip->bip_iter.bi_sector = bio->bi_iter.bi_sector;
651
652 pr_debug("IBLOCK BIP Size: %u Sector: %llu\n", bip->bip_iter.bi_size,
653 (unsigned long long)bip->bip_iter.bi_sector);
654
655 for_each_sg(cmd->t_prot_sg, sg, cmd->t_prot_nents, i) {
656
657 rc = bio_integrity_add_page(bio, sg_page(sg), sg->length,
658 sg->offset);
659 if (rc != sg->length) {
660 pr_err("bio_integrity_add_page() failed; %d\n", rc);
661 return -ENOMEM;
662 }
663
664 pr_debug("Added bio integrity page: %p length: %d offset; %d\n",
665 sg_page(sg), sg->length, sg->offset);
666 }
667
668 return 0;
669}
670
671static sense_reason_t
672iblock_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
673 enum dma_data_direction data_direction)
674{
675 struct se_device *dev = cmd->se_dev;
676 sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba);
677 struct iblock_req *ibr;
678 struct bio *bio, *bio_start;
679 struct bio_list list;
680 struct scatterlist *sg;
681 u32 sg_num = sgl_nents;
682 unsigned bio_cnt;
683 int i, op, op_flags = 0;
684
685 if (data_direction == DMA_TO_DEVICE) {
686 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
687 struct request_queue *q = bdev_get_queue(ib_dev->ibd_bd);
688 /*
689 * Force writethrough using REQ_FUA if a volatile write cache
690 * is not enabled, or if initiator set the Force Unit Access bit.
691 */
692 op = REQ_OP_WRITE;
693 if (test_bit(QUEUE_FLAG_FUA, &q->queue_flags)) {
694 if (cmd->se_cmd_flags & SCF_FUA)
695 op_flags = REQ_FUA;
696 else if (!test_bit(QUEUE_FLAG_WC, &q->queue_flags))
697 op_flags = REQ_FUA;
698 }
699 } else {
700 op = REQ_OP_READ;
701 }
702
703 ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
704 if (!ibr)
705 goto fail;
706 cmd->priv = ibr;
707
708 if (!sgl_nents) {
709 atomic_set(&ibr->pending, 1);
710 iblock_complete_cmd(cmd);
711 return 0;
712 }
713
714 bio = iblock_get_bio(cmd, block_lba, sgl_nents, op, op_flags);
715 if (!bio)
716 goto fail_free_ibr;
717
718 bio_start = bio;
719 bio_list_init(&list);
720 bio_list_add(&list, bio);
721
722 atomic_set(&ibr->pending, 2);
723 bio_cnt = 1;
724
725 for_each_sg(sgl, sg, sgl_nents, i) {
726 /*
727 * XXX: if the length the device accepts is shorter than the
728 * length of the S/G list entry this will cause and
729 * endless loop. Better hope no driver uses huge pages.
730 */
731 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
732 != sg->length) {
733 if (bio_cnt >= IBLOCK_MAX_BIO_PER_TASK) {
734 iblock_submit_bios(&list);
735 bio_cnt = 0;
736 }
737
738 bio = iblock_get_bio(cmd, block_lba, sg_num, op,
739 op_flags);
740 if (!bio)
741 goto fail_put_bios;
742
743 atomic_inc(&ibr->pending);
744 bio_list_add(&list, bio);
745 bio_cnt++;
746 }
747
748 /* Always in 512 byte units for Linux/Block */
749 block_lba += sg->length >> IBLOCK_LBA_SHIFT;
750 sg_num--;
751 }
752
753 if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
754 int rc = iblock_alloc_bip(cmd, bio_start);
755 if (rc)
756 goto fail_put_bios;
757 }
758
759 iblock_submit_bios(&list);
760 iblock_complete_cmd(cmd);
761 return 0;
762
763fail_put_bios:
764 while ((bio = bio_list_pop(&list)))
765 bio_put(bio);
766fail_free_ibr:
767 kfree(ibr);
768fail:
769 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
770}
771
772static sector_t iblock_get_blocks(struct se_device *dev)
773{
774 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
775 struct block_device *bd = ib_dev->ibd_bd;
776 struct request_queue *q = bdev_get_queue(bd);
777
778 return iblock_emulate_read_cap_with_block_size(dev, bd, q);
779}
780
781static sector_t iblock_get_alignment_offset_lbas(struct se_device *dev)
782{
783 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
784 struct block_device *bd = ib_dev->ibd_bd;
785 int ret;
786
787 ret = bdev_alignment_offset(bd);
788 if (ret == -1)
789 return 0;
790
791 /* convert offset-bytes to offset-lbas */
792 return ret / bdev_logical_block_size(bd);
793}
794
795static unsigned int iblock_get_lbppbe(struct se_device *dev)
796{
797 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
798 struct block_device *bd = ib_dev->ibd_bd;
799 int logs_per_phys = bdev_physical_block_size(bd) / bdev_logical_block_size(bd);
800
801 return ilog2(logs_per_phys);
802}
803
804static unsigned int iblock_get_io_min(struct se_device *dev)
805{
806 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
807 struct block_device *bd = ib_dev->ibd_bd;
808
809 return bdev_io_min(bd);
810}
811
812static unsigned int iblock_get_io_opt(struct se_device *dev)
813{
814 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
815 struct block_device *bd = ib_dev->ibd_bd;
816
817 return bdev_io_opt(bd);
818}
819
820static struct sbc_ops iblock_sbc_ops = {
821 .execute_rw = iblock_execute_rw,
822 .execute_sync_cache = iblock_execute_sync_cache,
823 .execute_write_same = iblock_execute_write_same,
824 .execute_unmap = iblock_execute_unmap,
825};
826
827static sense_reason_t
828iblock_parse_cdb(struct se_cmd *cmd)
829{
830 return sbc_parse_cdb(cmd, &iblock_sbc_ops);
831}
832
833static bool iblock_get_write_cache(struct se_device *dev)
834{
835 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
836 struct block_device *bd = ib_dev->ibd_bd;
837 struct request_queue *q = bdev_get_queue(bd);
838
839 return test_bit(QUEUE_FLAG_WC, &q->queue_flags);
840}
841
842static const struct target_backend_ops iblock_ops = {
843 .name = "iblock",
844 .inquiry_prod = "IBLOCK",
845 .inquiry_rev = IBLOCK_VERSION,
846 .owner = THIS_MODULE,
847 .attach_hba = iblock_attach_hba,
848 .detach_hba = iblock_detach_hba,
849 .alloc_device = iblock_alloc_device,
850 .configure_device = iblock_configure_device,
851 .free_device = iblock_free_device,
852 .parse_cdb = iblock_parse_cdb,
853 .set_configfs_dev_params = iblock_set_configfs_dev_params,
854 .show_configfs_dev_params = iblock_show_configfs_dev_params,
855 .get_device_type = sbc_get_device_type,
856 .get_blocks = iblock_get_blocks,
857 .get_alignment_offset_lbas = iblock_get_alignment_offset_lbas,
858 .get_lbppbe = iblock_get_lbppbe,
859 .get_io_min = iblock_get_io_min,
860 .get_io_opt = iblock_get_io_opt,
861 .get_write_cache = iblock_get_write_cache,
862 .tb_dev_attrib_attrs = sbc_attrib_attrs,
863};
864
865static int __init iblock_module_init(void)
866{
867 return transport_backend_register(&iblock_ops);
868}
869
870static void __exit iblock_module_exit(void)
871{
872 target_backend_unregister(&iblock_ops);
873}
874
875MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin");
876MODULE_AUTHOR("nab@Linux-iSCSI.org");
877MODULE_LICENSE("GPL");
878
879module_init(iblock_module_init);
880module_exit(iblock_module_exit);
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
49static inline struct iblock_dev *IBLOCK_DEV(struct se_device *dev)
50{
51 return container_of(dev, struct iblock_dev, dev);
52}
53
54
55static 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
63static void iblock_detach_hba(struct se_hba *hba)
64{
65}
66
67static 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
82static 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 dev->dev_attrib.hw_block_size))
126 pr_debug("IBLOCK: BLOCK Discard support available,"
127 " disabled by default\n");
128
129 /*
130 * Enable write same emulation for IBLOCK and use 0xFFFF as
131 * the smaller WRITE_SAME(10) only has a two-byte block count.
132 */
133 dev->dev_attrib.max_write_same_len = 0xFFFF;
134
135 if (blk_queue_nonrot(q))
136 dev->dev_attrib.is_nonrot = 1;
137
138 bi = bdev_get_integrity(bd);
139 if (bi) {
140 struct bio_set *bs = ib_dev->ibd_bio_set;
141
142 if (!strcmp(bi->profile->name, "T10-DIF-TYPE3-IP") ||
143 !strcmp(bi->profile->name, "T10-DIF-TYPE1-IP")) {
144 pr_err("IBLOCK export of blk_integrity: %s not"
145 " supported\n", bi->profile->name);
146 ret = -ENOSYS;
147 goto out_blkdev_put;
148 }
149
150 if (!strcmp(bi->profile->name, "T10-DIF-TYPE3-CRC")) {
151 dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE3_PROT;
152 } else if (!strcmp(bi->profile->name, "T10-DIF-TYPE1-CRC")) {
153 dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE1_PROT;
154 }
155
156 if (dev->dev_attrib.pi_prot_type) {
157 if (bioset_integrity_create(bs, IBLOCK_BIO_POOL_SIZE) < 0) {
158 pr_err("Unable to allocate bioset for PI\n");
159 ret = -ENOMEM;
160 goto out_blkdev_put;
161 }
162 pr_debug("IBLOCK setup BIP bs->bio_integrity_pool: %p\n",
163 bs->bio_integrity_pool);
164 }
165 dev->dev_attrib.hw_pi_prot_type = dev->dev_attrib.pi_prot_type;
166 }
167
168 return 0;
169
170out_blkdev_put:
171 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
172out_free_bioset:
173 bioset_free(ib_dev->ibd_bio_set);
174 ib_dev->ibd_bio_set = NULL;
175out:
176 return ret;
177}
178
179static void iblock_dev_call_rcu(struct rcu_head *p)
180{
181 struct se_device *dev = container_of(p, struct se_device, rcu_head);
182 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
183
184 kfree(ib_dev);
185}
186
187static void iblock_free_device(struct se_device *dev)
188{
189 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
190
191 if (ib_dev->ibd_bd != NULL)
192 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
193 if (ib_dev->ibd_bio_set != NULL)
194 bioset_free(ib_dev->ibd_bio_set);
195
196 call_rcu(&dev->rcu_head, iblock_dev_call_rcu);
197}
198
199static unsigned long long iblock_emulate_read_cap_with_block_size(
200 struct se_device *dev,
201 struct block_device *bd,
202 struct request_queue *q)
203{
204 unsigned long long blocks_long = (div_u64(i_size_read(bd->bd_inode),
205 bdev_logical_block_size(bd)) - 1);
206 u32 block_size = bdev_logical_block_size(bd);
207
208 if (block_size == dev->dev_attrib.block_size)
209 return blocks_long;
210
211 switch (block_size) {
212 case 4096:
213 switch (dev->dev_attrib.block_size) {
214 case 2048:
215 blocks_long <<= 1;
216 break;
217 case 1024:
218 blocks_long <<= 2;
219 break;
220 case 512:
221 blocks_long <<= 3;
222 default:
223 break;
224 }
225 break;
226 case 2048:
227 switch (dev->dev_attrib.block_size) {
228 case 4096:
229 blocks_long >>= 1;
230 break;
231 case 1024:
232 blocks_long <<= 1;
233 break;
234 case 512:
235 blocks_long <<= 2;
236 break;
237 default:
238 break;
239 }
240 break;
241 case 1024:
242 switch (dev->dev_attrib.block_size) {
243 case 4096:
244 blocks_long >>= 2;
245 break;
246 case 2048:
247 blocks_long >>= 1;
248 break;
249 case 512:
250 blocks_long <<= 1;
251 break;
252 default:
253 break;
254 }
255 break;
256 case 512:
257 switch (dev->dev_attrib.block_size) {
258 case 4096:
259 blocks_long >>= 3;
260 break;
261 case 2048:
262 blocks_long >>= 2;
263 break;
264 case 1024:
265 blocks_long >>= 1;
266 break;
267 default:
268 break;
269 }
270 break;
271 default:
272 break;
273 }
274
275 return blocks_long;
276}
277
278static void iblock_complete_cmd(struct se_cmd *cmd)
279{
280 struct iblock_req *ibr = cmd->priv;
281 u8 status;
282
283 if (!atomic_dec_and_test(&ibr->pending))
284 return;
285
286 if (atomic_read(&ibr->ib_bio_err_cnt))
287 status = SAM_STAT_CHECK_CONDITION;
288 else
289 status = SAM_STAT_GOOD;
290
291 target_complete_cmd(cmd, status);
292 kfree(ibr);
293}
294
295static void iblock_bio_done(struct bio *bio)
296{
297 struct se_cmd *cmd = bio->bi_private;
298 struct iblock_req *ibr = cmd->priv;
299
300 if (bio->bi_error) {
301 pr_err("bio error: %p, err: %d\n", bio, bio->bi_error);
302 /*
303 * Bump the ib_bio_err_cnt and release bio.
304 */
305 atomic_inc(&ibr->ib_bio_err_cnt);
306 smp_mb__after_atomic();
307 }
308
309 bio_put(bio);
310
311 iblock_complete_cmd(cmd);
312}
313
314static struct bio *
315iblock_get_bio(struct se_cmd *cmd, sector_t lba, u32 sg_num)
316{
317 struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
318 struct bio *bio;
319
320 /*
321 * Only allocate as many vector entries as the bio code allows us to,
322 * we'll loop later on until we have handled the whole request.
323 */
324 if (sg_num > BIO_MAX_PAGES)
325 sg_num = BIO_MAX_PAGES;
326
327 bio = bio_alloc_bioset(GFP_NOIO, sg_num, ib_dev->ibd_bio_set);
328 if (!bio) {
329 pr_err("Unable to allocate memory for bio\n");
330 return NULL;
331 }
332
333 bio->bi_bdev = ib_dev->ibd_bd;
334 bio->bi_private = cmd;
335 bio->bi_end_io = &iblock_bio_done;
336 bio->bi_iter.bi_sector = lba;
337
338 return bio;
339}
340
341static void iblock_submit_bios(struct bio_list *list, int rw)
342{
343 struct blk_plug plug;
344 struct bio *bio;
345
346 blk_start_plug(&plug);
347 while ((bio = bio_list_pop(list)))
348 submit_bio(rw, bio);
349 blk_finish_plug(&plug);
350}
351
352static void iblock_end_io_flush(struct bio *bio)
353{
354 struct se_cmd *cmd = bio->bi_private;
355
356 if (bio->bi_error)
357 pr_err("IBLOCK: cache flush failed: %d\n", bio->bi_error);
358
359 if (cmd) {
360 if (bio->bi_error)
361 target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
362 else
363 target_complete_cmd(cmd, SAM_STAT_GOOD);
364 }
365
366 bio_put(bio);
367}
368
369/*
370 * Implement SYCHRONIZE CACHE. Note that we can't handle lba ranges and must
371 * always flush the whole cache.
372 */
373static sense_reason_t
374iblock_execute_sync_cache(struct se_cmd *cmd)
375{
376 struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
377 int immed = (cmd->t_task_cdb[1] & 0x2);
378 struct bio *bio;
379
380 /*
381 * If the Immediate bit is set, queue up the GOOD response
382 * for this SYNCHRONIZE_CACHE op.
383 */
384 if (immed)
385 target_complete_cmd(cmd, SAM_STAT_GOOD);
386
387 bio = bio_alloc(GFP_KERNEL, 0);
388 bio->bi_end_io = iblock_end_io_flush;
389 bio->bi_bdev = ib_dev->ibd_bd;
390 if (!immed)
391 bio->bi_private = cmd;
392 submit_bio(WRITE_FLUSH, bio);
393 return 0;
394}
395
396static sense_reason_t
397iblock_execute_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
398{
399 struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
400 struct se_device *dev = cmd->se_dev;
401 int ret;
402
403 ret = blkdev_issue_discard(bdev,
404 target_to_linux_sector(dev, lba),
405 target_to_linux_sector(dev, nolb),
406 GFP_KERNEL, 0);
407 if (ret < 0) {
408 pr_err("blkdev_issue_discard() failed: %d\n", ret);
409 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
410 }
411
412 return 0;
413}
414
415static sense_reason_t
416iblock_execute_write_same_direct(struct block_device *bdev, struct se_cmd *cmd)
417{
418 struct se_device *dev = cmd->se_dev;
419 struct scatterlist *sg = &cmd->t_data_sg[0];
420 struct page *page = NULL;
421 int ret;
422
423 if (sg->offset) {
424 page = alloc_page(GFP_KERNEL);
425 if (!page)
426 return TCM_OUT_OF_RESOURCES;
427 sg_copy_to_buffer(sg, cmd->t_data_nents, page_address(page),
428 dev->dev_attrib.block_size);
429 }
430
431 ret = blkdev_issue_write_same(bdev,
432 target_to_linux_sector(dev, cmd->t_task_lba),
433 target_to_linux_sector(dev,
434 sbc_get_write_same_sectors(cmd)),
435 GFP_KERNEL, page ? page : sg_page(sg));
436 if (page)
437 __free_page(page);
438 if (ret)
439 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
440
441 target_complete_cmd(cmd, GOOD);
442 return 0;
443}
444
445static sense_reason_t
446iblock_execute_write_same(struct se_cmd *cmd)
447{
448 struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
449 struct iblock_req *ibr;
450 struct scatterlist *sg;
451 struct bio *bio;
452 struct bio_list list;
453 struct se_device *dev = cmd->se_dev;
454 sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba);
455 sector_t sectors = target_to_linux_sector(dev,
456 sbc_get_write_same_sectors(cmd));
457
458 if (cmd->prot_op) {
459 pr_err("WRITE_SAME: Protection information with IBLOCK"
460 " backends not supported\n");
461 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
462 }
463 sg = &cmd->t_data_sg[0];
464
465 if (cmd->t_data_nents > 1 ||
466 sg->length != cmd->se_dev->dev_attrib.block_size) {
467 pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
468 " block_size: %u\n", cmd->t_data_nents, sg->length,
469 cmd->se_dev->dev_attrib.block_size);
470 return TCM_INVALID_CDB_FIELD;
471 }
472
473 if (bdev_write_same(bdev))
474 return iblock_execute_write_same_direct(bdev, cmd);
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
510fail_put_bios:
511 while ((bio = bio_list_pop(&list)))
512 bio_put(bio);
513fail_free_ibr:
514 kfree(ibr);
515fail:
516 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
517}
518
519enum {
520 Opt_udev_path, Opt_readonly, Opt_force, Opt_err
521};
522
523static 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
530static 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
590out:
591 kfree(orig);
592 return (!ret) ? count : ret;
593}
594
595static 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
623static int
624iblock_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 (IS_ERR(bip)) {
641 pr_err("Unable to allocate bio_integrity_payload\n");
642 return PTR_ERR(bip);
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
668static sense_reason_t
669iblock_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 sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba);
674 struct iblock_req *ibr;
675 struct bio *bio, *bio_start;
676 struct bio_list list;
677 struct scatterlist *sg;
678 u32 sg_num = sgl_nents;
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 ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
705 if (!ibr)
706 goto fail;
707 cmd->priv = ibr;
708
709 if (!sgl_nents) {
710 atomic_set(&ibr->pending, 1);
711 iblock_complete_cmd(cmd);
712 return 0;
713 }
714
715 bio = iblock_get_bio(cmd, block_lba, sgl_nents);
716 if (!bio)
717 goto fail_free_ibr;
718
719 bio_start = bio;
720 bio_list_init(&list);
721 bio_list_add(&list, bio);
722
723 atomic_set(&ibr->pending, 2);
724 bio_cnt = 1;
725
726 for_each_sg(sgl, sg, sgl_nents, i) {
727 /*
728 * XXX: if the length the device accepts is shorter than the
729 * length of the S/G list entry this will cause and
730 * endless loop. Better hope no driver uses huge pages.
731 */
732 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
733 != sg->length) {
734 if (bio_cnt >= IBLOCK_MAX_BIO_PER_TASK) {
735 iblock_submit_bios(&list, rw);
736 bio_cnt = 0;
737 }
738
739 bio = iblock_get_bio(cmd, block_lba, sg_num);
740 if (!bio)
741 goto fail_put_bios;
742
743 atomic_inc(&ibr->pending);
744 bio_list_add(&list, bio);
745 bio_cnt++;
746 }
747
748 /* Always in 512 byte units for Linux/Block */
749 block_lba += sg->length >> IBLOCK_LBA_SHIFT;
750 sg_num--;
751 }
752
753 if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
754 int rc = iblock_alloc_bip(cmd, bio_start);
755 if (rc)
756 goto fail_put_bios;
757 }
758
759 iblock_submit_bios(&list, rw);
760 iblock_complete_cmd(cmd);
761 return 0;
762
763fail_put_bios:
764 while ((bio = bio_list_pop(&list)))
765 bio_put(bio);
766fail_free_ibr:
767 kfree(ibr);
768fail:
769 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
770}
771
772static sector_t iblock_get_blocks(struct se_device *dev)
773{
774 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
775 struct block_device *bd = ib_dev->ibd_bd;
776 struct request_queue *q = bdev_get_queue(bd);
777
778 return iblock_emulate_read_cap_with_block_size(dev, bd, q);
779}
780
781static sector_t iblock_get_alignment_offset_lbas(struct se_device *dev)
782{
783 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
784 struct block_device *bd = ib_dev->ibd_bd;
785 int ret;
786
787 ret = bdev_alignment_offset(bd);
788 if (ret == -1)
789 return 0;
790
791 /* convert offset-bytes to offset-lbas */
792 return ret / bdev_logical_block_size(bd);
793}
794
795static unsigned int iblock_get_lbppbe(struct se_device *dev)
796{
797 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
798 struct block_device *bd = ib_dev->ibd_bd;
799 int logs_per_phys = bdev_physical_block_size(bd) / bdev_logical_block_size(bd);
800
801 return ilog2(logs_per_phys);
802}
803
804static unsigned int iblock_get_io_min(struct se_device *dev)
805{
806 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
807 struct block_device *bd = ib_dev->ibd_bd;
808
809 return bdev_io_min(bd);
810}
811
812static unsigned int iblock_get_io_opt(struct se_device *dev)
813{
814 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
815 struct block_device *bd = ib_dev->ibd_bd;
816
817 return bdev_io_opt(bd);
818}
819
820static struct sbc_ops iblock_sbc_ops = {
821 .execute_rw = iblock_execute_rw,
822 .execute_sync_cache = iblock_execute_sync_cache,
823 .execute_write_same = iblock_execute_write_same,
824 .execute_unmap = iblock_execute_unmap,
825};
826
827static sense_reason_t
828iblock_parse_cdb(struct se_cmd *cmd)
829{
830 return sbc_parse_cdb(cmd, &iblock_sbc_ops);
831}
832
833static bool iblock_get_write_cache(struct se_device *dev)
834{
835 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
836 struct block_device *bd = ib_dev->ibd_bd;
837 struct request_queue *q = bdev_get_queue(bd);
838
839 return q->flush_flags & REQ_FLUSH;
840}
841
842static const struct target_backend_ops iblock_ops = {
843 .name = "iblock",
844 .inquiry_prod = "IBLOCK",
845 .inquiry_rev = IBLOCK_VERSION,
846 .owner = THIS_MODULE,
847 .attach_hba = iblock_attach_hba,
848 .detach_hba = iblock_detach_hba,
849 .alloc_device = iblock_alloc_device,
850 .configure_device = iblock_configure_device,
851 .free_device = iblock_free_device,
852 .parse_cdb = iblock_parse_cdb,
853 .set_configfs_dev_params = iblock_set_configfs_dev_params,
854 .show_configfs_dev_params = iblock_show_configfs_dev_params,
855 .get_device_type = sbc_get_device_type,
856 .get_blocks = iblock_get_blocks,
857 .get_alignment_offset_lbas = iblock_get_alignment_offset_lbas,
858 .get_lbppbe = iblock_get_lbppbe,
859 .get_io_min = iblock_get_io_min,
860 .get_io_opt = iblock_get_io_opt,
861 .get_write_cache = iblock_get_write_cache,
862 .tb_dev_attrib_attrs = sbc_attrib_attrs,
863};
864
865static int __init iblock_module_init(void)
866{
867 return transport_backend_register(&iblock_ops);
868}
869
870static void __exit iblock_module_exit(void)
871{
872 target_backend_unregister(&iblock_ops);
873}
874
875MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin");
876MODULE_AUTHOR("nab@Linux-iSCSI.org");
877MODULE_LICENSE("GPL");
878
879module_init(iblock_module_init);
880module_exit(iblock_module_exit);