Loading...
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*******************************************************************************
3 * Filename: target_core_iblock.c
4 *
5 * This file contains the Storage Engine <-> Linux BlockIO transport
6 * specific functions.
7 *
8 * (c) Copyright 2003-2013 Datera, Inc.
9 *
10 * Nicholas A. Bellinger <nab@kernel.org>
11 *
12 ******************************************************************************/
13
14#include <linux/string.h>
15#include <linux/parser.h>
16#include <linux/timer.h>
17#include <linux/fs.h>
18#include <linux/blkdev.h>
19#include <linux/slab.h>
20#include <linux/spinlock.h>
21#include <linux/bio.h>
22#include <linux/genhd.h>
23#include <linux/file.h>
24#include <linux/module.h>
25#include <scsi/scsi_proto.h>
26#include <asm/unaligned.h>
27
28#include <target/target_core_base.h>
29#include <target/target_core_backend.h>
30
31#include "target_core_iblock.h"
32
33#define IBLOCK_MAX_BIO_PER_TASK 32 /* max # of bios to submit at a time */
34#define IBLOCK_BIO_POOL_SIZE 128
35
36static inline struct iblock_dev *IBLOCK_DEV(struct se_device *dev)
37{
38 return container_of(dev, struct iblock_dev, dev);
39}
40
41
42static int iblock_attach_hba(struct se_hba *hba, u32 host_id)
43{
44 pr_debug("CORE_HBA[%d] - TCM iBlock HBA Driver %s on"
45 " Generic Target Core Stack %s\n", hba->hba_id,
46 IBLOCK_VERSION, TARGET_CORE_VERSION);
47 return 0;
48}
49
50static void iblock_detach_hba(struct se_hba *hba)
51{
52}
53
54static struct se_device *iblock_alloc_device(struct se_hba *hba, const char *name)
55{
56 struct iblock_dev *ib_dev = NULL;
57
58 ib_dev = kzalloc(sizeof(struct iblock_dev), GFP_KERNEL);
59 if (!ib_dev) {
60 pr_err("Unable to allocate struct iblock_dev\n");
61 return NULL;
62 }
63
64 pr_debug( "IBLOCK: Allocated ib_dev for %s\n", name);
65
66 return &ib_dev->dev;
67}
68
69static int iblock_configure_device(struct se_device *dev)
70{
71 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
72 struct request_queue *q;
73 struct block_device *bd = NULL;
74 struct blk_integrity *bi;
75 fmode_t mode;
76 unsigned int max_write_zeroes_sectors;
77 int ret = -ENOMEM;
78
79 if (!(ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)) {
80 pr_err("Missing udev_path= parameters for IBLOCK\n");
81 return -EINVAL;
82 }
83
84 ret = bioset_init(&ib_dev->ibd_bio_set, IBLOCK_BIO_POOL_SIZE, 0, BIOSET_NEED_BVECS);
85 if (ret) {
86 pr_err("IBLOCK: Unable to create bioset\n");
87 goto out;
88 }
89
90 pr_debug( "IBLOCK: Claiming struct block_device: %s\n",
91 ib_dev->ibd_udev_path);
92
93 mode = FMODE_READ|FMODE_EXCL;
94 if (!ib_dev->ibd_readonly)
95 mode |= FMODE_WRITE;
96 else
97 dev->dev_flags |= DF_READ_ONLY;
98
99 bd = blkdev_get_by_path(ib_dev->ibd_udev_path, mode, ib_dev);
100 if (IS_ERR(bd)) {
101 ret = PTR_ERR(bd);
102 goto out_free_bioset;
103 }
104 ib_dev->ibd_bd = bd;
105
106 q = bdev_get_queue(bd);
107
108 dev->dev_attrib.hw_block_size = bdev_logical_block_size(bd);
109 dev->dev_attrib.hw_max_sectors = queue_max_hw_sectors(q);
110 dev->dev_attrib.hw_queue_depth = q->nr_requests;
111
112 if (target_configure_unmap_from_queue(&dev->dev_attrib, q))
113 pr_debug("IBLOCK: BLOCK Discard support available,"
114 " disabled by default\n");
115
116 /*
117 * Enable write same emulation for IBLOCK and use 0xFFFF as
118 * the smaller WRITE_SAME(10) only has a two-byte block count.
119 */
120 max_write_zeroes_sectors = bdev_write_zeroes_sectors(bd);
121 if (max_write_zeroes_sectors)
122 dev->dev_attrib.max_write_same_len = max_write_zeroes_sectors;
123 else
124 dev->dev_attrib.max_write_same_len = 0xFFFF;
125
126 if (blk_queue_nonrot(q))
127 dev->dev_attrib.is_nonrot = 1;
128
129 bi = bdev_get_integrity(bd);
130 if (bi) {
131 struct bio_set *bs = &ib_dev->ibd_bio_set;
132
133 if (!strcmp(bi->profile->name, "T10-DIF-TYPE3-IP") ||
134 !strcmp(bi->profile->name, "T10-DIF-TYPE1-IP")) {
135 pr_err("IBLOCK export of blk_integrity: %s not"
136 " supported\n", bi->profile->name);
137 ret = -ENOSYS;
138 goto out_blkdev_put;
139 }
140
141 if (!strcmp(bi->profile->name, "T10-DIF-TYPE3-CRC")) {
142 dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE3_PROT;
143 } else if (!strcmp(bi->profile->name, "T10-DIF-TYPE1-CRC")) {
144 dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE1_PROT;
145 }
146
147 if (dev->dev_attrib.pi_prot_type) {
148 if (bioset_integrity_create(bs, IBLOCK_BIO_POOL_SIZE) < 0) {
149 pr_err("Unable to allocate bioset for PI\n");
150 ret = -ENOMEM;
151 goto out_blkdev_put;
152 }
153 pr_debug("IBLOCK setup BIP bs->bio_integrity_pool: %p\n",
154 &bs->bio_integrity_pool);
155 }
156 dev->dev_attrib.hw_pi_prot_type = dev->dev_attrib.pi_prot_type;
157 }
158
159 return 0;
160
161out_blkdev_put:
162 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
163out_free_bioset:
164 bioset_exit(&ib_dev->ibd_bio_set);
165out:
166 return ret;
167}
168
169static void iblock_dev_call_rcu(struct rcu_head *p)
170{
171 struct se_device *dev = container_of(p, struct se_device, rcu_head);
172 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
173
174 kfree(ib_dev);
175}
176
177static void iblock_free_device(struct se_device *dev)
178{
179 call_rcu(&dev->rcu_head, iblock_dev_call_rcu);
180}
181
182static void iblock_destroy_device(struct se_device *dev)
183{
184 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
185
186 if (ib_dev->ibd_bd != NULL)
187 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
188 bioset_exit(&ib_dev->ibd_bio_set);
189}
190
191static unsigned long long iblock_emulate_read_cap_with_block_size(
192 struct se_device *dev,
193 struct block_device *bd,
194 struct request_queue *q)
195{
196 unsigned long long blocks_long = (div_u64(i_size_read(bd->bd_inode),
197 bdev_logical_block_size(bd)) - 1);
198 u32 block_size = bdev_logical_block_size(bd);
199
200 if (block_size == dev->dev_attrib.block_size)
201 return blocks_long;
202
203 switch (block_size) {
204 case 4096:
205 switch (dev->dev_attrib.block_size) {
206 case 2048:
207 blocks_long <<= 1;
208 break;
209 case 1024:
210 blocks_long <<= 2;
211 break;
212 case 512:
213 blocks_long <<= 3;
214 default:
215 break;
216 }
217 break;
218 case 2048:
219 switch (dev->dev_attrib.block_size) {
220 case 4096:
221 blocks_long >>= 1;
222 break;
223 case 1024:
224 blocks_long <<= 1;
225 break;
226 case 512:
227 blocks_long <<= 2;
228 break;
229 default:
230 break;
231 }
232 break;
233 case 1024:
234 switch (dev->dev_attrib.block_size) {
235 case 4096:
236 blocks_long >>= 2;
237 break;
238 case 2048:
239 blocks_long >>= 1;
240 break;
241 case 512:
242 blocks_long <<= 1;
243 break;
244 default:
245 break;
246 }
247 break;
248 case 512:
249 switch (dev->dev_attrib.block_size) {
250 case 4096:
251 blocks_long >>= 3;
252 break;
253 case 2048:
254 blocks_long >>= 2;
255 break;
256 case 1024:
257 blocks_long >>= 1;
258 break;
259 default:
260 break;
261 }
262 break;
263 default:
264 break;
265 }
266
267 return blocks_long;
268}
269
270static void iblock_complete_cmd(struct se_cmd *cmd)
271{
272 struct iblock_req *ibr = cmd->priv;
273 u8 status;
274
275 if (!refcount_dec_and_test(&ibr->pending))
276 return;
277
278 if (atomic_read(&ibr->ib_bio_err_cnt))
279 status = SAM_STAT_CHECK_CONDITION;
280 else
281 status = SAM_STAT_GOOD;
282
283 target_complete_cmd(cmd, status);
284 kfree(ibr);
285}
286
287static void iblock_bio_done(struct bio *bio)
288{
289 struct se_cmd *cmd = bio->bi_private;
290 struct iblock_req *ibr = cmd->priv;
291
292 if (bio->bi_status) {
293 pr_err("bio error: %p, err: %d\n", bio, bio->bi_status);
294 /*
295 * Bump the ib_bio_err_cnt and release bio.
296 */
297 atomic_inc(&ibr->ib_bio_err_cnt);
298 smp_mb__after_atomic();
299 }
300
301 bio_put(bio);
302
303 iblock_complete_cmd(cmd);
304}
305
306static struct bio *
307iblock_get_bio(struct se_cmd *cmd, sector_t lba, u32 sg_num, int op,
308 int op_flags)
309{
310 struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
311 struct bio *bio;
312
313 /*
314 * Only allocate as many vector entries as the bio code allows us to,
315 * we'll loop later on until we have handled the whole request.
316 */
317 if (sg_num > BIO_MAX_PAGES)
318 sg_num = BIO_MAX_PAGES;
319
320 bio = bio_alloc_bioset(GFP_NOIO, sg_num, &ib_dev->ibd_bio_set);
321 if (!bio) {
322 pr_err("Unable to allocate memory for bio\n");
323 return NULL;
324 }
325
326 bio_set_dev(bio, ib_dev->ibd_bd);
327 bio->bi_private = cmd;
328 bio->bi_end_io = &iblock_bio_done;
329 bio->bi_iter.bi_sector = lba;
330 bio_set_op_attrs(bio, op, op_flags);
331
332 return bio;
333}
334
335static void iblock_submit_bios(struct bio_list *list)
336{
337 struct blk_plug plug;
338 struct bio *bio;
339
340 blk_start_plug(&plug);
341 while ((bio = bio_list_pop(list)))
342 submit_bio(bio);
343 blk_finish_plug(&plug);
344}
345
346static void iblock_end_io_flush(struct bio *bio)
347{
348 struct se_cmd *cmd = bio->bi_private;
349
350 if (bio->bi_status)
351 pr_err("IBLOCK: cache flush failed: %d\n", bio->bi_status);
352
353 if (cmd) {
354 if (bio->bi_status)
355 target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
356 else
357 target_complete_cmd(cmd, SAM_STAT_GOOD);
358 }
359
360 bio_put(bio);
361}
362
363/*
364 * Implement SYCHRONIZE CACHE. Note that we can't handle lba ranges and must
365 * always flush the whole cache.
366 */
367static sense_reason_t
368iblock_execute_sync_cache(struct se_cmd *cmd)
369{
370 struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
371 int immed = (cmd->t_task_cdb[1] & 0x2);
372 struct bio *bio;
373
374 /*
375 * If the Immediate bit is set, queue up the GOOD response
376 * for this SYNCHRONIZE_CACHE op.
377 */
378 if (immed)
379 target_complete_cmd(cmd, SAM_STAT_GOOD);
380
381 bio = bio_alloc(GFP_KERNEL, 0);
382 bio->bi_end_io = iblock_end_io_flush;
383 bio_set_dev(bio, ib_dev->ibd_bd);
384 bio->bi_opf = REQ_OP_WRITE | REQ_PREFLUSH;
385 if (!immed)
386 bio->bi_private = cmd;
387 submit_bio(bio);
388 return 0;
389}
390
391static sense_reason_t
392iblock_execute_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
393{
394 struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
395 struct se_device *dev = cmd->se_dev;
396 int ret;
397
398 ret = blkdev_issue_discard(bdev,
399 target_to_linux_sector(dev, lba),
400 target_to_linux_sector(dev, nolb),
401 GFP_KERNEL, 0);
402 if (ret < 0) {
403 pr_err("blkdev_issue_discard() failed: %d\n", ret);
404 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
405 }
406
407 return 0;
408}
409
410static sense_reason_t
411iblock_execute_zero_out(struct block_device *bdev, struct se_cmd *cmd)
412{
413 struct se_device *dev = cmd->se_dev;
414 struct scatterlist *sg = &cmd->t_data_sg[0];
415 unsigned char *buf, *not_zero;
416 int ret;
417
418 buf = kmap(sg_page(sg)) + sg->offset;
419 if (!buf)
420 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
421 /*
422 * Fall back to block_execute_write_same() slow-path if
423 * incoming WRITE_SAME payload does not contain zeros.
424 */
425 not_zero = memchr_inv(buf, 0x00, cmd->data_length);
426 kunmap(sg_page(sg));
427
428 if (not_zero)
429 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
430
431 ret = blkdev_issue_zeroout(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, BLKDEV_ZERO_NOUNMAP);
436 if (ret)
437 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
438
439 target_complete_cmd(cmd, GOOD);
440 return 0;
441}
442
443static sense_reason_t
444iblock_execute_write_same(struct se_cmd *cmd)
445{
446 struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
447 struct iblock_req *ibr;
448 struct scatterlist *sg;
449 struct bio *bio;
450 struct bio_list list;
451 struct se_device *dev = cmd->se_dev;
452 sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba);
453 sector_t sectors = target_to_linux_sector(dev,
454 sbc_get_write_same_sectors(cmd));
455
456 if (cmd->prot_op) {
457 pr_err("WRITE_SAME: Protection information with IBLOCK"
458 " backends not supported\n");
459 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
460 }
461 sg = &cmd->t_data_sg[0];
462
463 if (cmd->t_data_nents > 1 ||
464 sg->length != cmd->se_dev->dev_attrib.block_size) {
465 pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
466 " block_size: %u\n", cmd->t_data_nents, sg->length,
467 cmd->se_dev->dev_attrib.block_size);
468 return TCM_INVALID_CDB_FIELD;
469 }
470
471 if (bdev_write_zeroes_sectors(bdev)) {
472 if (!iblock_execute_zero_out(bdev, cmd))
473 return 0;
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, REQ_OP_WRITE, 0);
482 if (!bio)
483 goto fail_free_ibr;
484
485 bio_list_init(&list);
486 bio_list_add(&list, bio);
487
488 refcount_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, REQ_OP_WRITE,
495 0);
496 if (!bio)
497 goto fail_put_bios;
498
499 refcount_inc(&ibr->pending);
500 bio_list_add(&list, bio);
501 }
502
503 /* Always in 512 byte units for Linux/Block */
504 block_lba += sg->length >> SECTOR_SHIFT;
505 sectors -= sg->length >> SECTOR_SHIFT;
506 }
507
508 iblock_submit_bios(&list);
509 return 0;
510
511fail_put_bios:
512 while ((bio = bio_list_pop(&list)))
513 bio_put(bio);
514fail_free_ibr:
515 kfree(ibr);
516fail:
517 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
518}
519
520enum {
521 Opt_udev_path, Opt_readonly, Opt_force, Opt_err
522};
523
524static match_table_t tokens = {
525 {Opt_udev_path, "udev_path=%s"},
526 {Opt_readonly, "readonly=%d"},
527 {Opt_force, "force=%d"},
528 {Opt_err, NULL}
529};
530
531static ssize_t iblock_set_configfs_dev_params(struct se_device *dev,
532 const char *page, ssize_t count)
533{
534 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
535 char *orig, *ptr, *arg_p, *opts;
536 substring_t args[MAX_OPT_ARGS];
537 int ret = 0, token;
538 unsigned long tmp_readonly;
539
540 opts = kstrdup(page, GFP_KERNEL);
541 if (!opts)
542 return -ENOMEM;
543
544 orig = opts;
545
546 while ((ptr = strsep(&opts, ",\n")) != NULL) {
547 if (!*ptr)
548 continue;
549
550 token = match_token(ptr, tokens, args);
551 switch (token) {
552 case Opt_udev_path:
553 if (ib_dev->ibd_bd) {
554 pr_err("Unable to set udev_path= while"
555 " ib_dev->ibd_bd exists\n");
556 ret = -EEXIST;
557 goto out;
558 }
559 if (match_strlcpy(ib_dev->ibd_udev_path, &args[0],
560 SE_UDEV_PATH_LEN) == 0) {
561 ret = -EINVAL;
562 break;
563 }
564 pr_debug("IBLOCK: Referencing UDEV path: %s\n",
565 ib_dev->ibd_udev_path);
566 ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH;
567 break;
568 case Opt_readonly:
569 arg_p = match_strdup(&args[0]);
570 if (!arg_p) {
571 ret = -ENOMEM;
572 break;
573 }
574 ret = kstrtoul(arg_p, 0, &tmp_readonly);
575 kfree(arg_p);
576 if (ret < 0) {
577 pr_err("kstrtoul() failed for"
578 " readonly=\n");
579 goto out;
580 }
581 ib_dev->ibd_readonly = tmp_readonly;
582 pr_debug("IBLOCK: readonly: %d\n", ib_dev->ibd_readonly);
583 break;
584 case Opt_force:
585 break;
586 default:
587 break;
588 }
589 }
590
591out:
592 kfree(orig);
593 return (!ret) ? count : ret;
594}
595
596static ssize_t iblock_show_configfs_dev_params(struct se_device *dev, char *b)
597{
598 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
599 struct block_device *bd = ib_dev->ibd_bd;
600 char buf[BDEVNAME_SIZE];
601 ssize_t bl = 0;
602
603 if (bd)
604 bl += sprintf(b + bl, "iBlock device: %s",
605 bdevname(bd, buf));
606 if (ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)
607 bl += sprintf(b + bl, " UDEV PATH: %s",
608 ib_dev->ibd_udev_path);
609 bl += sprintf(b + bl, " readonly: %d\n", ib_dev->ibd_readonly);
610
611 bl += sprintf(b + bl, " ");
612 if (bd) {
613 bl += sprintf(b + bl, "Major: %d Minor: %d %s\n",
614 MAJOR(bd->bd_dev), MINOR(bd->bd_dev), (!bd->bd_contains) ?
615 "" : (bd->bd_holder == ib_dev) ?
616 "CLAIMED: IBLOCK" : "CLAIMED: OS");
617 } else {
618 bl += sprintf(b + bl, "Major: 0 Minor: 0\n");
619 }
620
621 return bl;
622}
623
624static int
625iblock_alloc_bip(struct se_cmd *cmd, struct bio *bio,
626 struct sg_mapping_iter *miter)
627{
628 struct se_device *dev = cmd->se_dev;
629 struct blk_integrity *bi;
630 struct bio_integrity_payload *bip;
631 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
632 int rc;
633 size_t resid, len;
634
635 bi = bdev_get_integrity(ib_dev->ibd_bd);
636 if (!bi) {
637 pr_err("Unable to locate bio_integrity\n");
638 return -ENODEV;
639 }
640
641 bip = bio_integrity_alloc(bio, GFP_NOIO,
642 min_t(unsigned int, cmd->t_prot_nents, BIO_MAX_PAGES));
643 if (IS_ERR(bip)) {
644 pr_err("Unable to allocate bio_integrity_payload\n");
645 return PTR_ERR(bip);
646 }
647
648 bip->bip_iter.bi_size = bio_integrity_bytes(bi, bio_sectors(bio));
649 /* virtual start sector must be in integrity interval units */
650 bip_set_seed(bip, bio->bi_iter.bi_sector >>
651 (bi->interval_exp - SECTOR_SHIFT));
652
653 pr_debug("IBLOCK BIP Size: %u Sector: %llu\n", bip->bip_iter.bi_size,
654 (unsigned long long)bip->bip_iter.bi_sector);
655
656 resid = bip->bip_iter.bi_size;
657 while (resid > 0 && sg_miter_next(miter)) {
658
659 len = min_t(size_t, miter->length, resid);
660 rc = bio_integrity_add_page(bio, miter->page, len,
661 offset_in_page(miter->addr));
662 if (rc != len) {
663 pr_err("bio_integrity_add_page() failed; %d\n", rc);
664 sg_miter_stop(miter);
665 return -ENOMEM;
666 }
667
668 pr_debug("Added bio integrity page: %p length: %zu offset: %lu\n",
669 miter->page, len, offset_in_page(miter->addr));
670
671 resid -= len;
672 if (len < miter->length)
673 miter->consumed -= miter->length - len;
674 }
675 sg_miter_stop(miter);
676
677 return 0;
678}
679
680static sense_reason_t
681iblock_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
682 enum dma_data_direction data_direction)
683{
684 struct se_device *dev = cmd->se_dev;
685 sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba);
686 struct iblock_req *ibr;
687 struct bio *bio;
688 struct bio_list list;
689 struct scatterlist *sg;
690 u32 sg_num = sgl_nents;
691 unsigned bio_cnt;
692 int i, rc, op, op_flags = 0;
693 struct sg_mapping_iter prot_miter;
694
695 if (data_direction == DMA_TO_DEVICE) {
696 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
697 struct request_queue *q = bdev_get_queue(ib_dev->ibd_bd);
698 /*
699 * Force writethrough using REQ_FUA if a volatile write cache
700 * is not enabled, or if initiator set the Force Unit Access bit.
701 */
702 op = REQ_OP_WRITE;
703 if (test_bit(QUEUE_FLAG_FUA, &q->queue_flags)) {
704 if (cmd->se_cmd_flags & SCF_FUA)
705 op_flags = REQ_FUA;
706 else if (!test_bit(QUEUE_FLAG_WC, &q->queue_flags))
707 op_flags = REQ_FUA;
708 }
709 } else {
710 op = REQ_OP_READ;
711 }
712
713 ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
714 if (!ibr)
715 goto fail;
716 cmd->priv = ibr;
717
718 if (!sgl_nents) {
719 refcount_set(&ibr->pending, 1);
720 iblock_complete_cmd(cmd);
721 return 0;
722 }
723
724 bio = iblock_get_bio(cmd, block_lba, sgl_nents, op, op_flags);
725 if (!bio)
726 goto fail_free_ibr;
727
728 bio_list_init(&list);
729 bio_list_add(&list, bio);
730
731 refcount_set(&ibr->pending, 2);
732 bio_cnt = 1;
733
734 if (cmd->prot_type && dev->dev_attrib.pi_prot_type)
735 sg_miter_start(&prot_miter, cmd->t_prot_sg, cmd->t_prot_nents,
736 op == REQ_OP_READ ? SG_MITER_FROM_SG :
737 SG_MITER_TO_SG);
738
739 for_each_sg(sgl, sg, sgl_nents, i) {
740 /*
741 * XXX: if the length the device accepts is shorter than the
742 * length of the S/G list entry this will cause and
743 * endless loop. Better hope no driver uses huge pages.
744 */
745 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
746 != sg->length) {
747 if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
748 rc = iblock_alloc_bip(cmd, bio, &prot_miter);
749 if (rc)
750 goto fail_put_bios;
751 }
752
753 if (bio_cnt >= IBLOCK_MAX_BIO_PER_TASK) {
754 iblock_submit_bios(&list);
755 bio_cnt = 0;
756 }
757
758 bio = iblock_get_bio(cmd, block_lba, sg_num, op,
759 op_flags);
760 if (!bio)
761 goto fail_put_bios;
762
763 refcount_inc(&ibr->pending);
764 bio_list_add(&list, bio);
765 bio_cnt++;
766 }
767
768 /* Always in 512 byte units for Linux/Block */
769 block_lba += sg->length >> SECTOR_SHIFT;
770 sg_num--;
771 }
772
773 if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
774 rc = iblock_alloc_bip(cmd, bio, &prot_miter);
775 if (rc)
776 goto fail_put_bios;
777 }
778
779 iblock_submit_bios(&list);
780 iblock_complete_cmd(cmd);
781 return 0;
782
783fail_put_bios:
784 while ((bio = bio_list_pop(&list)))
785 bio_put(bio);
786fail_free_ibr:
787 kfree(ibr);
788fail:
789 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
790}
791
792static sector_t iblock_get_blocks(struct se_device *dev)
793{
794 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
795 struct block_device *bd = ib_dev->ibd_bd;
796 struct request_queue *q = bdev_get_queue(bd);
797
798 return iblock_emulate_read_cap_with_block_size(dev, bd, q);
799}
800
801static sector_t iblock_get_alignment_offset_lbas(struct se_device *dev)
802{
803 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
804 struct block_device *bd = ib_dev->ibd_bd;
805 int ret;
806
807 ret = bdev_alignment_offset(bd);
808 if (ret == -1)
809 return 0;
810
811 /* convert offset-bytes to offset-lbas */
812 return ret / bdev_logical_block_size(bd);
813}
814
815static unsigned int iblock_get_lbppbe(struct se_device *dev)
816{
817 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
818 struct block_device *bd = ib_dev->ibd_bd;
819 int logs_per_phys = bdev_physical_block_size(bd) / bdev_logical_block_size(bd);
820
821 return ilog2(logs_per_phys);
822}
823
824static unsigned int iblock_get_io_min(struct se_device *dev)
825{
826 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
827 struct block_device *bd = ib_dev->ibd_bd;
828
829 return bdev_io_min(bd);
830}
831
832static unsigned int iblock_get_io_opt(struct se_device *dev)
833{
834 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
835 struct block_device *bd = ib_dev->ibd_bd;
836
837 return bdev_io_opt(bd);
838}
839
840static struct sbc_ops iblock_sbc_ops = {
841 .execute_rw = iblock_execute_rw,
842 .execute_sync_cache = iblock_execute_sync_cache,
843 .execute_write_same = iblock_execute_write_same,
844 .execute_unmap = iblock_execute_unmap,
845};
846
847static sense_reason_t
848iblock_parse_cdb(struct se_cmd *cmd)
849{
850 return sbc_parse_cdb(cmd, &iblock_sbc_ops);
851}
852
853static bool iblock_get_write_cache(struct se_device *dev)
854{
855 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
856 struct block_device *bd = ib_dev->ibd_bd;
857 struct request_queue *q = bdev_get_queue(bd);
858
859 return test_bit(QUEUE_FLAG_WC, &q->queue_flags);
860}
861
862static const struct target_backend_ops iblock_ops = {
863 .name = "iblock",
864 .inquiry_prod = "IBLOCK",
865 .inquiry_rev = IBLOCK_VERSION,
866 .owner = THIS_MODULE,
867 .attach_hba = iblock_attach_hba,
868 .detach_hba = iblock_detach_hba,
869 .alloc_device = iblock_alloc_device,
870 .configure_device = iblock_configure_device,
871 .destroy_device = iblock_destroy_device,
872 .free_device = iblock_free_device,
873 .parse_cdb = iblock_parse_cdb,
874 .set_configfs_dev_params = iblock_set_configfs_dev_params,
875 .show_configfs_dev_params = iblock_show_configfs_dev_params,
876 .get_device_type = sbc_get_device_type,
877 .get_blocks = iblock_get_blocks,
878 .get_alignment_offset_lbas = iblock_get_alignment_offset_lbas,
879 .get_lbppbe = iblock_get_lbppbe,
880 .get_io_min = iblock_get_io_min,
881 .get_io_opt = iblock_get_io_opt,
882 .get_write_cache = iblock_get_write_cache,
883 .tb_dev_attrib_attrs = sbc_attrib_attrs,
884};
885
886static int __init iblock_module_init(void)
887{
888 return transport_backend_register(&iblock_ops);
889}
890
891static void __exit iblock_module_exit(void)
892{
893 target_backend_unregister(&iblock_ops);
894}
895
896MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin");
897MODULE_AUTHOR("nab@Linux-iSCSI.org");
898MODULE_LICENSE("GPL");
899
900module_init(iblock_module_init);
901module_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 * Copyright (c) 2003, 2004, 2005 PyX Technologies, Inc.
8 * Copyright (c) 2005, 2006, 2007 SBE, Inc.
9 * Copyright (c) 2007-2010 Rising Tide Systems
10 * Copyright (c) 2008-2010 Linux-iSCSI.org
11 *
12 * Nicholas A. Bellinger <nab@kernel.org>
13 *
14 * This program is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2 of the License, or
17 * (at your option) any later version.
18 *
19 * This program is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU General Public License for more details.
23 *
24 * You should have received a copy of the GNU General Public License
25 * along with this program; if not, write to the Free Software
26 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
27 *
28 ******************************************************************************/
29
30#include <linux/version.h>
31#include <linux/string.h>
32#include <linux/parser.h>
33#include <linux/timer.h>
34#include <linux/fs.h>
35#include <linux/blkdev.h>
36#include <linux/slab.h>
37#include <linux/spinlock.h>
38#include <linux/bio.h>
39#include <linux/genhd.h>
40#include <linux/file.h>
41#include <scsi/scsi.h>
42#include <scsi/scsi_host.h>
43
44#include <target/target_core_base.h>
45#include <target/target_core_device.h>
46#include <target/target_core_transport.h>
47
48#include "target_core_iblock.h"
49
50static struct se_subsystem_api iblock_template;
51
52static void iblock_bio_done(struct bio *, int);
53
54/* iblock_attach_hba(): (Part of se_subsystem_api_t template)
55 *
56 *
57 */
58static int iblock_attach_hba(struct se_hba *hba, u32 host_id)
59{
60 struct iblock_hba *ib_host;
61
62 ib_host = kzalloc(sizeof(struct iblock_hba), GFP_KERNEL);
63 if (!ib_host) {
64 pr_err("Unable to allocate memory for"
65 " struct iblock_hba\n");
66 return -ENOMEM;
67 }
68
69 ib_host->iblock_host_id = host_id;
70
71 hba->hba_ptr = ib_host;
72
73 pr_debug("CORE_HBA[%d] - TCM iBlock HBA Driver %s on"
74 " Generic Target Core Stack %s\n", hba->hba_id,
75 IBLOCK_VERSION, TARGET_CORE_MOD_VERSION);
76
77 pr_debug("CORE_HBA[%d] - Attached iBlock HBA: %u to Generic\n",
78 hba->hba_id, ib_host->iblock_host_id);
79
80 return 0;
81}
82
83static void iblock_detach_hba(struct se_hba *hba)
84{
85 struct iblock_hba *ib_host = hba->hba_ptr;
86
87 pr_debug("CORE_HBA[%d] - Detached iBlock HBA: %u from Generic"
88 " Target Core\n", hba->hba_id, ib_host->iblock_host_id);
89
90 kfree(ib_host);
91 hba->hba_ptr = NULL;
92}
93
94static void *iblock_allocate_virtdevice(struct se_hba *hba, const char *name)
95{
96 struct iblock_dev *ib_dev = NULL;
97 struct iblock_hba *ib_host = hba->hba_ptr;
98
99 ib_dev = kzalloc(sizeof(struct iblock_dev), GFP_KERNEL);
100 if (!ib_dev) {
101 pr_err("Unable to allocate struct iblock_dev\n");
102 return NULL;
103 }
104 ib_dev->ibd_host = ib_host;
105
106 pr_debug( "IBLOCK: Allocated ib_dev for %s\n", name);
107
108 return ib_dev;
109}
110
111static struct se_device *iblock_create_virtdevice(
112 struct se_hba *hba,
113 struct se_subsystem_dev *se_dev,
114 void *p)
115{
116 struct iblock_dev *ib_dev = p;
117 struct se_device *dev;
118 struct se_dev_limits dev_limits;
119 struct block_device *bd = NULL;
120 struct request_queue *q;
121 struct queue_limits *limits;
122 u32 dev_flags = 0;
123 int ret = -EINVAL;
124
125 if (!ib_dev) {
126 pr_err("Unable to locate struct iblock_dev parameter\n");
127 return ERR_PTR(ret);
128 }
129 memset(&dev_limits, 0, sizeof(struct se_dev_limits));
130 /*
131 * These settings need to be made tunable..
132 */
133 ib_dev->ibd_bio_set = bioset_create(32, 64);
134 if (!ib_dev->ibd_bio_set) {
135 pr_err("IBLOCK: Unable to create bioset()\n");
136 return ERR_PTR(-ENOMEM);
137 }
138 pr_debug("IBLOCK: Created bio_set()\n");
139 /*
140 * iblock_check_configfs_dev_params() ensures that ib_dev->ibd_udev_path
141 * must already have been set in order for echo 1 > $HBA/$DEV/enable to run.
142 */
143 pr_debug( "IBLOCK: Claiming struct block_device: %s\n",
144 ib_dev->ibd_udev_path);
145
146 bd = blkdev_get_by_path(ib_dev->ibd_udev_path,
147 FMODE_WRITE|FMODE_READ|FMODE_EXCL, ib_dev);
148 if (IS_ERR(bd)) {
149 ret = PTR_ERR(bd);
150 goto failed;
151 }
152 /*
153 * Setup the local scope queue_limits from struct request_queue->limits
154 * to pass into transport_add_device_to_core_hba() as struct se_dev_limits.
155 */
156 q = bdev_get_queue(bd);
157 limits = &dev_limits.limits;
158 limits->logical_block_size = bdev_logical_block_size(bd);
159 limits->max_hw_sectors = queue_max_hw_sectors(q);
160 limits->max_sectors = queue_max_sectors(q);
161 dev_limits.hw_queue_depth = q->nr_requests;
162 dev_limits.queue_depth = q->nr_requests;
163
164 ib_dev->ibd_bd = bd;
165
166 dev = transport_add_device_to_core_hba(hba,
167 &iblock_template, se_dev, dev_flags, ib_dev,
168 &dev_limits, "IBLOCK", IBLOCK_VERSION);
169 if (!dev)
170 goto failed;
171
172 /*
173 * Check if the underlying struct block_device request_queue supports
174 * the QUEUE_FLAG_DISCARD bit for UNMAP/WRITE_SAME in SCSI + TRIM
175 * in ATA and we need to set TPE=1
176 */
177 if (blk_queue_discard(q)) {
178 dev->se_sub_dev->se_dev_attrib.max_unmap_lba_count =
179 q->limits.max_discard_sectors;
180 /*
181 * Currently hardcoded to 1 in Linux/SCSI code..
182 */
183 dev->se_sub_dev->se_dev_attrib.max_unmap_block_desc_count = 1;
184 dev->se_sub_dev->se_dev_attrib.unmap_granularity =
185 q->limits.discard_granularity;
186 dev->se_sub_dev->se_dev_attrib.unmap_granularity_alignment =
187 q->limits.discard_alignment;
188
189 pr_debug("IBLOCK: BLOCK Discard support available,"
190 " disabled by default\n");
191 }
192
193 if (blk_queue_nonrot(q))
194 dev->se_sub_dev->se_dev_attrib.is_nonrot = 1;
195
196 return dev;
197
198failed:
199 if (ib_dev->ibd_bio_set) {
200 bioset_free(ib_dev->ibd_bio_set);
201 ib_dev->ibd_bio_set = NULL;
202 }
203 ib_dev->ibd_bd = NULL;
204 return ERR_PTR(ret);
205}
206
207static void iblock_free_device(void *p)
208{
209 struct iblock_dev *ib_dev = p;
210
211 if (ib_dev->ibd_bd != NULL)
212 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
213 if (ib_dev->ibd_bio_set != NULL)
214 bioset_free(ib_dev->ibd_bio_set);
215 kfree(ib_dev);
216}
217
218static inline struct iblock_req *IBLOCK_REQ(struct se_task *task)
219{
220 return container_of(task, struct iblock_req, ib_task);
221}
222
223static struct se_task *
224iblock_alloc_task(unsigned char *cdb)
225{
226 struct iblock_req *ib_req;
227
228 ib_req = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
229 if (!ib_req) {
230 pr_err("Unable to allocate memory for struct iblock_req\n");
231 return NULL;
232 }
233
234 atomic_set(&ib_req->ib_bio_cnt, 0);
235 return &ib_req->ib_task;
236}
237
238static unsigned long long iblock_emulate_read_cap_with_block_size(
239 struct se_device *dev,
240 struct block_device *bd,
241 struct request_queue *q)
242{
243 unsigned long long blocks_long = (div_u64(i_size_read(bd->bd_inode),
244 bdev_logical_block_size(bd)) - 1);
245 u32 block_size = bdev_logical_block_size(bd);
246
247 if (block_size == dev->se_sub_dev->se_dev_attrib.block_size)
248 return blocks_long;
249
250 switch (block_size) {
251 case 4096:
252 switch (dev->se_sub_dev->se_dev_attrib.block_size) {
253 case 2048:
254 blocks_long <<= 1;
255 break;
256 case 1024:
257 blocks_long <<= 2;
258 break;
259 case 512:
260 blocks_long <<= 3;
261 default:
262 break;
263 }
264 break;
265 case 2048:
266 switch (dev->se_sub_dev->se_dev_attrib.block_size) {
267 case 4096:
268 blocks_long >>= 1;
269 break;
270 case 1024:
271 blocks_long <<= 1;
272 break;
273 case 512:
274 blocks_long <<= 2;
275 break;
276 default:
277 break;
278 }
279 break;
280 case 1024:
281 switch (dev->se_sub_dev->se_dev_attrib.block_size) {
282 case 4096:
283 blocks_long >>= 2;
284 break;
285 case 2048:
286 blocks_long >>= 1;
287 break;
288 case 512:
289 blocks_long <<= 1;
290 break;
291 default:
292 break;
293 }
294 break;
295 case 512:
296 switch (dev->se_sub_dev->se_dev_attrib.block_size) {
297 case 4096:
298 blocks_long >>= 3;
299 break;
300 case 2048:
301 blocks_long >>= 2;
302 break;
303 case 1024:
304 blocks_long >>= 1;
305 break;
306 default:
307 break;
308 }
309 break;
310 default:
311 break;
312 }
313
314 return blocks_long;
315}
316
317/*
318 * Emulate SYCHRONIZE_CACHE_*
319 */
320static void iblock_emulate_sync_cache(struct se_task *task)
321{
322 struct se_cmd *cmd = task->task_se_cmd;
323 struct iblock_dev *ib_dev = cmd->se_dev->dev_ptr;
324 int immed = (cmd->t_task_cdb[1] & 0x2);
325 sector_t error_sector;
326 int ret;
327
328 /*
329 * If the Immediate bit is set, queue up the GOOD response
330 * for this SYNCHRONIZE_CACHE op
331 */
332 if (immed)
333 transport_complete_sync_cache(cmd, 1);
334
335 /*
336 * blkdev_issue_flush() does not support a specifying a range, so
337 * we have to flush the entire cache.
338 */
339 ret = blkdev_issue_flush(ib_dev->ibd_bd, GFP_KERNEL, &error_sector);
340 if (ret != 0) {
341 pr_err("IBLOCK: block_issue_flush() failed: %d "
342 " error_sector: %llu\n", ret,
343 (unsigned long long)error_sector);
344 }
345
346 if (!immed)
347 transport_complete_sync_cache(cmd, ret == 0);
348}
349
350/*
351 * Tell TCM Core that we are capable of WriteCache emulation for
352 * an underlying struct se_device.
353 */
354static int iblock_emulated_write_cache(struct se_device *dev)
355{
356 return 1;
357}
358
359static int iblock_emulated_dpo(struct se_device *dev)
360{
361 return 0;
362}
363
364/*
365 * Tell TCM Core that we will be emulating Forced Unit Access (FUA) for WRITEs
366 * for TYPE_DISK.
367 */
368static int iblock_emulated_fua_write(struct se_device *dev)
369{
370 return 1;
371}
372
373static int iblock_emulated_fua_read(struct se_device *dev)
374{
375 return 0;
376}
377
378static int iblock_do_task(struct se_task *task)
379{
380 struct se_device *dev = task->task_se_cmd->se_dev;
381 struct iblock_req *req = IBLOCK_REQ(task);
382 struct bio *bio = req->ib_bio, *nbio = NULL;
383 struct blk_plug plug;
384 int rw;
385
386 if (task->task_data_direction == DMA_TO_DEVICE) {
387 /*
388 * Force data to disk if we pretend to not have a volatile
389 * write cache, or the initiator set the Force Unit Access bit.
390 */
391 if (dev->se_sub_dev->se_dev_attrib.emulate_write_cache == 0 ||
392 (dev->se_sub_dev->se_dev_attrib.emulate_fua_write > 0 &&
393 task->task_se_cmd->t_tasks_fua))
394 rw = WRITE_FUA;
395 else
396 rw = WRITE;
397 } else {
398 rw = READ;
399 }
400
401 blk_start_plug(&plug);
402 while (bio) {
403 nbio = bio->bi_next;
404 bio->bi_next = NULL;
405 pr_debug("Calling submit_bio() task: %p bio: %p"
406 " bio->bi_sector: %llu\n", task, bio,
407 (unsigned long long)bio->bi_sector);
408
409 submit_bio(rw, bio);
410 bio = nbio;
411 }
412 blk_finish_plug(&plug);
413
414 return PYX_TRANSPORT_SENT_TO_TRANSPORT;
415}
416
417static int iblock_do_discard(struct se_device *dev, sector_t lba, u32 range)
418{
419 struct iblock_dev *ibd = dev->dev_ptr;
420 struct block_device *bd = ibd->ibd_bd;
421 int barrier = 0;
422
423 return blkdev_issue_discard(bd, lba, range, GFP_KERNEL, barrier);
424}
425
426static void iblock_free_task(struct se_task *task)
427{
428 struct iblock_req *req = IBLOCK_REQ(task);
429 struct bio *bio, *hbio = req->ib_bio;
430 /*
431 * We only release the bio(s) here if iblock_bio_done() has not called
432 * bio_put() -> iblock_bio_destructor().
433 */
434 while (hbio != NULL) {
435 bio = hbio;
436 hbio = hbio->bi_next;
437 bio->bi_next = NULL;
438 bio_put(bio);
439 }
440
441 kfree(req);
442}
443
444enum {
445 Opt_udev_path, Opt_force, Opt_err
446};
447
448static match_table_t tokens = {
449 {Opt_udev_path, "udev_path=%s"},
450 {Opt_force, "force=%d"},
451 {Opt_err, NULL}
452};
453
454static ssize_t iblock_set_configfs_dev_params(struct se_hba *hba,
455 struct se_subsystem_dev *se_dev,
456 const char *page, ssize_t count)
457{
458 struct iblock_dev *ib_dev = se_dev->se_dev_su_ptr;
459 char *orig, *ptr, *arg_p, *opts;
460 substring_t args[MAX_OPT_ARGS];
461 int ret = 0, token;
462
463 opts = kstrdup(page, GFP_KERNEL);
464 if (!opts)
465 return -ENOMEM;
466
467 orig = opts;
468
469 while ((ptr = strsep(&opts, ",")) != NULL) {
470 if (!*ptr)
471 continue;
472
473 token = match_token(ptr, tokens, args);
474 switch (token) {
475 case Opt_udev_path:
476 if (ib_dev->ibd_bd) {
477 pr_err("Unable to set udev_path= while"
478 " ib_dev->ibd_bd exists\n");
479 ret = -EEXIST;
480 goto out;
481 }
482 arg_p = match_strdup(&args[0]);
483 if (!arg_p) {
484 ret = -ENOMEM;
485 break;
486 }
487 snprintf(ib_dev->ibd_udev_path, SE_UDEV_PATH_LEN,
488 "%s", arg_p);
489 kfree(arg_p);
490 pr_debug("IBLOCK: Referencing UDEV path: %s\n",
491 ib_dev->ibd_udev_path);
492 ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH;
493 break;
494 case Opt_force:
495 break;
496 default:
497 break;
498 }
499 }
500
501out:
502 kfree(orig);
503 return (!ret) ? count : ret;
504}
505
506static ssize_t iblock_check_configfs_dev_params(
507 struct se_hba *hba,
508 struct se_subsystem_dev *se_dev)
509{
510 struct iblock_dev *ibd = se_dev->se_dev_su_ptr;
511
512 if (!(ibd->ibd_flags & IBDF_HAS_UDEV_PATH)) {
513 pr_err("Missing udev_path= parameters for IBLOCK\n");
514 return -EINVAL;
515 }
516
517 return 0;
518}
519
520static ssize_t iblock_show_configfs_dev_params(
521 struct se_hba *hba,
522 struct se_subsystem_dev *se_dev,
523 char *b)
524{
525 struct iblock_dev *ibd = se_dev->se_dev_su_ptr;
526 struct block_device *bd = ibd->ibd_bd;
527 char buf[BDEVNAME_SIZE];
528 ssize_t bl = 0;
529
530 if (bd)
531 bl += sprintf(b + bl, "iBlock device: %s",
532 bdevname(bd, buf));
533 if (ibd->ibd_flags & IBDF_HAS_UDEV_PATH) {
534 bl += sprintf(b + bl, " UDEV PATH: %s\n",
535 ibd->ibd_udev_path);
536 } else
537 bl += sprintf(b + bl, "\n");
538
539 bl += sprintf(b + bl, " ");
540 if (bd) {
541 bl += sprintf(b + bl, "Major: %d Minor: %d %s\n",
542 MAJOR(bd->bd_dev), MINOR(bd->bd_dev), (!bd->bd_contains) ?
543 "" : (bd->bd_holder == (struct iblock_dev *)ibd) ?
544 "CLAIMED: IBLOCK" : "CLAIMED: OS");
545 } else {
546 bl += sprintf(b + bl, "Major: 0 Minor: 0\n");
547 }
548
549 return bl;
550}
551
552static void iblock_bio_destructor(struct bio *bio)
553{
554 struct se_task *task = bio->bi_private;
555 struct iblock_dev *ib_dev = task->se_dev->dev_ptr;
556
557 bio_free(bio, ib_dev->ibd_bio_set);
558}
559
560static struct bio *iblock_get_bio(
561 struct se_task *task,
562 struct iblock_req *ib_req,
563 struct iblock_dev *ib_dev,
564 int *ret,
565 sector_t lba,
566 u32 sg_num)
567{
568 struct bio *bio;
569
570 bio = bio_alloc_bioset(GFP_NOIO, sg_num, ib_dev->ibd_bio_set);
571 if (!bio) {
572 pr_err("Unable to allocate memory for bio\n");
573 *ret = PYX_TRANSPORT_OUT_OF_MEMORY_RESOURCES;
574 return NULL;
575 }
576
577 pr_debug("Allocated bio: %p task_sg_nents: %u using ibd_bio_set:"
578 " %p\n", bio, task->task_sg_nents, ib_dev->ibd_bio_set);
579 pr_debug("Allocated bio: %p task_size: %u\n", bio, task->task_size);
580
581 bio->bi_bdev = ib_dev->ibd_bd;
582 bio->bi_private = task;
583 bio->bi_destructor = iblock_bio_destructor;
584 bio->bi_end_io = &iblock_bio_done;
585 bio->bi_sector = lba;
586 atomic_inc(&ib_req->ib_bio_cnt);
587
588 pr_debug("Set bio->bi_sector: %llu\n", (unsigned long long)bio->bi_sector);
589 pr_debug("Set ib_req->ib_bio_cnt: %d\n",
590 atomic_read(&ib_req->ib_bio_cnt));
591 return bio;
592}
593
594static int iblock_map_data_SG(struct se_task *task)
595{
596 struct se_cmd *cmd = task->task_se_cmd;
597 struct se_device *dev = cmd->se_dev;
598 struct iblock_dev *ib_dev = task->se_dev->dev_ptr;
599 struct iblock_req *ib_req = IBLOCK_REQ(task);
600 struct bio *bio = NULL, *hbio = NULL, *tbio = NULL;
601 struct scatterlist *sg;
602 int ret = 0;
603 u32 i, sg_num = task->task_sg_nents;
604 sector_t block_lba;
605 /*
606 * Do starting conversion up from non 512-byte blocksize with
607 * struct se_task SCSI blocksize into Linux/Block 512 units for BIO.
608 */
609 if (dev->se_sub_dev->se_dev_attrib.block_size == 4096)
610 block_lba = (task->task_lba << 3);
611 else if (dev->se_sub_dev->se_dev_attrib.block_size == 2048)
612 block_lba = (task->task_lba << 2);
613 else if (dev->se_sub_dev->se_dev_attrib.block_size == 1024)
614 block_lba = (task->task_lba << 1);
615 else if (dev->se_sub_dev->se_dev_attrib.block_size == 512)
616 block_lba = task->task_lba;
617 else {
618 pr_err("Unsupported SCSI -> BLOCK LBA conversion:"
619 " %u\n", dev->se_sub_dev->se_dev_attrib.block_size);
620 return PYX_TRANSPORT_LU_COMM_FAILURE;
621 }
622
623 bio = iblock_get_bio(task, ib_req, ib_dev, &ret, block_lba, sg_num);
624 if (!bio)
625 return ret;
626
627 ib_req->ib_bio = bio;
628 hbio = tbio = bio;
629 /*
630 * Use fs/bio.c:bio_add_pages() to setup the bio_vec maplist
631 * from task->task_sg -> struct scatterlist memory.
632 */
633 for_each_sg(task->task_sg, sg, task->task_sg_nents, i) {
634 pr_debug("task: %p bio: %p Calling bio_add_page(): page:"
635 " %p len: %u offset: %u\n", task, bio, sg_page(sg),
636 sg->length, sg->offset);
637again:
638 ret = bio_add_page(bio, sg_page(sg), sg->length, sg->offset);
639 if (ret != sg->length) {
640
641 pr_debug("*** Set bio->bi_sector: %llu\n",
642 (unsigned long long)bio->bi_sector);
643 pr_debug("** task->task_size: %u\n",
644 task->task_size);
645 pr_debug("*** bio->bi_max_vecs: %u\n",
646 bio->bi_max_vecs);
647 pr_debug("*** bio->bi_vcnt: %u\n",
648 bio->bi_vcnt);
649
650 bio = iblock_get_bio(task, ib_req, ib_dev, &ret,
651 block_lba, sg_num);
652 if (!bio)
653 goto fail;
654
655 tbio = tbio->bi_next = bio;
656 pr_debug("-----------------> Added +1 bio: %p to"
657 " list, Going to again\n", bio);
658 goto again;
659 }
660 /* Always in 512 byte units for Linux/Block */
661 block_lba += sg->length >> IBLOCK_LBA_SHIFT;
662 sg_num--;
663 pr_debug("task: %p bio-add_page() passed!, decremented"
664 " sg_num to %u\n", task, sg_num);
665 pr_debug("task: %p bio_add_page() passed!, increased lba"
666 " to %llu\n", task, (unsigned long long)block_lba);
667 pr_debug("task: %p bio_add_page() passed!, bio->bi_vcnt:"
668 " %u\n", task, bio->bi_vcnt);
669 }
670
671 return 0;
672fail:
673 while (hbio) {
674 bio = hbio;
675 hbio = hbio->bi_next;
676 bio->bi_next = NULL;
677 bio_put(bio);
678 }
679 return ret;
680}
681
682static unsigned char *iblock_get_cdb(struct se_task *task)
683{
684 return IBLOCK_REQ(task)->ib_scsi_cdb;
685}
686
687static u32 iblock_get_device_rev(struct se_device *dev)
688{
689 return SCSI_SPC_2; /* Returns SPC-3 in Initiator Data */
690}
691
692static u32 iblock_get_device_type(struct se_device *dev)
693{
694 return TYPE_DISK;
695}
696
697static sector_t iblock_get_blocks(struct se_device *dev)
698{
699 struct iblock_dev *ibd = dev->dev_ptr;
700 struct block_device *bd = ibd->ibd_bd;
701 struct request_queue *q = bdev_get_queue(bd);
702
703 return iblock_emulate_read_cap_with_block_size(dev, bd, q);
704}
705
706static void iblock_bio_done(struct bio *bio, int err)
707{
708 struct se_task *task = bio->bi_private;
709 struct iblock_req *ibr = IBLOCK_REQ(task);
710 /*
711 * Set -EIO if !BIO_UPTODATE and the passed is still err=0
712 */
713 if (!test_bit(BIO_UPTODATE, &bio->bi_flags) && !err)
714 err = -EIO;
715
716 if (err != 0) {
717 pr_err("test_bit(BIO_UPTODATE) failed for bio: %p,"
718 " err: %d\n", bio, err);
719 /*
720 * Bump the ib_bio_err_cnt and release bio.
721 */
722 atomic_inc(&ibr->ib_bio_err_cnt);
723 smp_mb__after_atomic_inc();
724 bio_put(bio);
725 /*
726 * Wait to complete the task until the last bio as completed.
727 */
728 if (!atomic_dec_and_test(&ibr->ib_bio_cnt))
729 return;
730
731 ibr->ib_bio = NULL;
732 transport_complete_task(task, 0);
733 return;
734 }
735 pr_debug("done[%p] bio: %p task_lba: %llu bio_lba: %llu err=%d\n",
736 task, bio, task->task_lba, (unsigned long long)bio->bi_sector, err);
737 /*
738 * bio_put() will call iblock_bio_destructor() to release the bio back
739 * to ibr->ib_bio_set.
740 */
741 bio_put(bio);
742 /*
743 * Wait to complete the task until the last bio as completed.
744 */
745 if (!atomic_dec_and_test(&ibr->ib_bio_cnt))
746 return;
747 /*
748 * Return GOOD status for task if zero ib_bio_err_cnt exists.
749 */
750 ibr->ib_bio = NULL;
751 transport_complete_task(task, (!atomic_read(&ibr->ib_bio_err_cnt)));
752}
753
754static struct se_subsystem_api iblock_template = {
755 .name = "iblock",
756 .owner = THIS_MODULE,
757 .transport_type = TRANSPORT_PLUGIN_VHBA_PDEV,
758 .map_data_SG = iblock_map_data_SG,
759 .attach_hba = iblock_attach_hba,
760 .detach_hba = iblock_detach_hba,
761 .allocate_virtdevice = iblock_allocate_virtdevice,
762 .create_virtdevice = iblock_create_virtdevice,
763 .free_device = iblock_free_device,
764 .dpo_emulated = iblock_emulated_dpo,
765 .fua_write_emulated = iblock_emulated_fua_write,
766 .fua_read_emulated = iblock_emulated_fua_read,
767 .write_cache_emulated = iblock_emulated_write_cache,
768 .alloc_task = iblock_alloc_task,
769 .do_task = iblock_do_task,
770 .do_discard = iblock_do_discard,
771 .do_sync_cache = iblock_emulate_sync_cache,
772 .free_task = iblock_free_task,
773 .check_configfs_dev_params = iblock_check_configfs_dev_params,
774 .set_configfs_dev_params = iblock_set_configfs_dev_params,
775 .show_configfs_dev_params = iblock_show_configfs_dev_params,
776 .get_cdb = iblock_get_cdb,
777 .get_device_rev = iblock_get_device_rev,
778 .get_device_type = iblock_get_device_type,
779 .get_blocks = iblock_get_blocks,
780};
781
782static int __init iblock_module_init(void)
783{
784 return transport_subsystem_register(&iblock_template);
785}
786
787static void iblock_module_exit(void)
788{
789 transport_subsystem_release(&iblock_template);
790}
791
792MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin");
793MODULE_AUTHOR("nab@Linux-iSCSI.org");
794MODULE_LICENSE("GPL");
795
796module_init(iblock_module_init);
797module_exit(iblock_module_exit);