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iscsi-target: Add MaxXmitDataSegmentLength connection recovery check
[linux-2.6/btrfs-unstable.git] / drivers / target / target_core_iblock.c
blob29408d46a6d9227130fab6aeb180b49ca05baf16
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/string.h>
31 #include <linux/parser.h>
32 #include <linux/timer.h>
33 #include <linux/fs.h>
34 #include <linux/blkdev.h>
35 #include <linux/slab.h>
36 #include <linux/spinlock.h>
37 #include <linux/bio.h>
38 #include <linux/genhd.h>
39 #include <linux/file.h>
40 #include <linux/module.h>
41 #include <scsi/scsi.h>
42 #include <scsi/scsi_host.h>
43 #include <asm/unaligned.h>
44
45 #include <target/target_core_base.h>
46 #include <target/target_core_backend.h>
47
48 #include "target_core_iblock.h"
49
50 #define IBLOCK_MAX_BIO_PER_TASK 32 /* max # of bios to submit at a time */
51 #define IBLOCK_BIO_POOL_SIZE 128
52
53 static struct se_subsystem_api iblock_template;
54
55 static void iblock_bio_done(struct bio *, int);
56
57 /* iblock_attach_hba(): (Part of se_subsystem_api_t template)
58 *
59 *
60 */
61 static int iblock_attach_hba(struct se_hba *hba, u32 host_id)
62 {
63 pr_debug("CORE_HBA[%d] - TCM iBlock HBA Driver %s on"
64 " Generic Target Core Stack %s\n", hba->hba_id,
65 IBLOCK_VERSION, TARGET_CORE_MOD_VERSION);
66 return 0;
67 }
68
69 static void iblock_detach_hba(struct se_hba *hba)
70 {
71 }
72
73 static void *iblock_allocate_virtdevice(struct se_hba *hba, const char *name)
74 {
75 struct iblock_dev *ib_dev = NULL;
76
77 ib_dev = kzalloc(sizeof(struct iblock_dev), GFP_KERNEL);
78 if (!ib_dev) {
79 pr_err("Unable to allocate struct iblock_dev\n");
80 return NULL;
81 }
82
83 pr_debug( "IBLOCK: Allocated ib_dev for %s\n", name);
84
85 return ib_dev;
86 }
87
88 static struct se_device *iblock_create_virtdevice(
89 struct se_hba *hba,
90 struct se_subsystem_dev *se_dev,
91 void *p)
92 {
93 struct iblock_dev *ib_dev = p;
94 struct se_device *dev;
95 struct se_dev_limits dev_limits;
96 struct block_device *bd = NULL;
97 struct request_queue *q;
98 struct queue_limits *limits;
99 u32 dev_flags = 0;
100 fmode_t mode;
101 int ret = -EINVAL;
102
103 if (!ib_dev) {
104 pr_err("Unable to locate struct iblock_dev parameter\n");
105 return ERR_PTR(ret);
106 }
107 memset(&dev_limits, 0, sizeof(struct se_dev_limits));
108
109 ib_dev->ibd_bio_set = bioset_create(IBLOCK_BIO_POOL_SIZE, 0);
110 if (!ib_dev->ibd_bio_set) {
111 pr_err("IBLOCK: Unable to create bioset()\n");
112 return ERR_PTR(-ENOMEM);
113 }
114 pr_debug("IBLOCK: Created bio_set()\n");
115 /*
116 * iblock_check_configfs_dev_params() ensures that ib_dev->ibd_udev_path
117 * must already have been set in order for echo 1 > $HBA/$DEV/enable to run.
118 */
119 pr_debug( "IBLOCK: Claiming struct block_device: %s\n",
120 ib_dev->ibd_udev_path);
121
122 mode = FMODE_READ|FMODE_EXCL;
123 if (!ib_dev->ibd_readonly)
124 mode |= FMODE_WRITE;
125
126 bd = blkdev_get_by_path(ib_dev->ibd_udev_path, mode, ib_dev);
127 if (IS_ERR(bd)) {
128 ret = PTR_ERR(bd);
129 goto failed;
130 }
131 /*
132 * Setup the local scope queue_limits from struct request_queue->limits
133 * to pass into transport_add_device_to_core_hba() as struct se_dev_limits.
134 */
135 q = bdev_get_queue(bd);
136 limits = &dev_limits.limits;
137 limits->logical_block_size = bdev_logical_block_size(bd);
138 limits->max_hw_sectors = UINT_MAX;
139 limits->max_sectors = UINT_MAX;
140 dev_limits.hw_queue_depth = q->nr_requests;
141 dev_limits.queue_depth = q->nr_requests;
142
143 ib_dev->ibd_bd = bd;
144
145 dev = transport_add_device_to_core_hba(hba,
146 &iblock_template, se_dev, dev_flags, ib_dev,
147 &dev_limits, "IBLOCK", IBLOCK_VERSION);
148 if (!dev)
149 goto failed;
150
151 /*
152 * Check if the underlying struct block_device request_queue supports
153 * the QUEUE_FLAG_DISCARD bit for UNMAP/WRITE_SAME in SCSI + TRIM
154 * in ATA and we need to set TPE=1
155 */
156 if (blk_queue_discard(q)) {
157 dev->se_sub_dev->se_dev_attrib.max_unmap_lba_count =
158 q->limits.max_discard_sectors;
159 /*
160 * Currently hardcoded to 1 in Linux/SCSI code..
161 */
162 dev->se_sub_dev->se_dev_attrib.max_unmap_block_desc_count = 1;
163 dev->se_sub_dev->se_dev_attrib.unmap_granularity =
164 q->limits.discard_granularity >> 9;
165 dev->se_sub_dev->se_dev_attrib.unmap_granularity_alignment =
166 q->limits.discard_alignment;
167
168 pr_debug("IBLOCK: BLOCK Discard support available,"
169 " disabled by default\n");
170 }
171
172 if (blk_queue_nonrot(q))
173 dev->se_sub_dev->se_dev_attrib.is_nonrot = 1;
174
175 return dev;
176
177 failed:
178 if (ib_dev->ibd_bio_set) {
179 bioset_free(ib_dev->ibd_bio_set);
180 ib_dev->ibd_bio_set = NULL;
181 }
182 ib_dev->ibd_bd = NULL;
183 return ERR_PTR(ret);
184 }
185
186 static void iblock_free_device(void *p)
187 {
188 struct iblock_dev *ib_dev = p;
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 kfree(ib_dev);
195 }
196
197 static unsigned long long iblock_emulate_read_cap_with_block_size(
198 struct se_device *dev,
199 struct block_device *bd,
200 struct request_queue *q)
201 {
202 unsigned long long blocks_long = (div_u64(i_size_read(bd->bd_inode),
203 bdev_logical_block_size(bd)) - 1);
204 u32 block_size = bdev_logical_block_size(bd);
205
206 if (block_size == dev->se_sub_dev->se_dev_attrib.block_size)
207 return blocks_long;
208
209 switch (block_size) {
210 case 4096:
211 switch (dev->se_sub_dev->se_dev_attrib.block_size) {
212 case 2048:
213 blocks_long <<= 1;
214 break;
215 case 1024:
216 blocks_long <<= 2;
217 break;
218 case 512:
219 blocks_long <<= 3;
220 default:
221 break;
222 }
223 break;
224 case 2048:
225 switch (dev->se_sub_dev->se_dev_attrib.block_size) {
226 case 4096:
227 blocks_long >>= 1;
228 break;
229 case 1024:
230 blocks_long <<= 1;
231 break;
232 case 512:
233 blocks_long <<= 2;
234 break;
235 default:
236 break;
237 }
238 break;
239 case 1024:
240 switch (dev->se_sub_dev->se_dev_attrib.block_size) {
241 case 4096:
242 blocks_long >>= 2;
243 break;
244 case 2048:
245 blocks_long >>= 1;
246 break;
247 case 512:
248 blocks_long <<= 1;
249 break;
250 default:
251 break;
252 }
253 break;
254 case 512:
255 switch (dev->se_sub_dev->se_dev_attrib.block_size) {
256 case 4096:
257 blocks_long >>= 3;
258 break;
259 case 2048:
260 blocks_long >>= 2;
261 break;
262 case 1024:
263 blocks_long >>= 1;
264 break;
265 default:
266 break;
267 }
268 break;
269 default:
270 break;
271 }
272
273 return blocks_long;
274 }
275
276 static void iblock_end_io_flush(struct bio *bio, int err)
277 {
278 struct se_cmd *cmd = bio->bi_private;
279
280 if (err)
281 pr_err("IBLOCK: cache flush failed: %d\n", err);
282
283 if (cmd) {
284 if (err) {
285 cmd->scsi_sense_reason =
286 TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
287 target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
288 } else {
289 target_complete_cmd(cmd, SAM_STAT_GOOD);
290 }
291 }
292
293 bio_put(bio);
294 }
295
296 /*
297 * Implement SYCHRONIZE CACHE. Note that we can't handle lba ranges and must
298 * always flush the whole cache.
299 */
300 static int iblock_execute_sync_cache(struct se_cmd *cmd)
301 {
302 struct iblock_dev *ib_dev = cmd->se_dev->dev_ptr;
303 int immed = (cmd->t_task_cdb[1] & 0x2);
304 struct bio *bio;
305
306 /*
307 * If the Immediate bit is set, queue up the GOOD response
308 * for this SYNCHRONIZE_CACHE op.
309 */
310 if (immed)
311 target_complete_cmd(cmd, SAM_STAT_GOOD);
312
313 bio = bio_alloc(GFP_KERNEL, 0);
314 bio->bi_end_io = iblock_end_io_flush;
315 bio->bi_bdev = ib_dev->ibd_bd;
316 if (!immed)
317 bio->bi_private = cmd;
318 submit_bio(WRITE_FLUSH, bio);
319 return 0;
320 }
321
322 static int iblock_execute_unmap(struct se_cmd *cmd)
323 {
324 struct se_device *dev = cmd->se_dev;
325 struct iblock_dev *ibd = dev->dev_ptr;
326 unsigned char *buf, *ptr = NULL;
327 sector_t lba;
328 int size;
329 u32 range;
330 int ret = 0;
331 int dl, bd_dl;
332
333 if (cmd->data_length < 8) {
334 pr_warn("UNMAP parameter list length %u too small\n",
335 cmd->data_length);
336 cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
337 return -EINVAL;
338 }
339
340 buf = transport_kmap_data_sg(cmd);
341
342 dl = get_unaligned_be16(&buf[0]);
343 bd_dl = get_unaligned_be16(&buf[2]);
344
345 size = cmd->data_length - 8;
346 if (bd_dl > size)
347 pr_warn("UNMAP parameter list length %u too small, ignoring bd_dl %u\n",
348 cmd->data_length, bd_dl);
349 else
350 size = bd_dl;
351
352 if (size / 16 > dev->se_sub_dev->se_dev_attrib.max_unmap_block_desc_count) {
353 cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
354 ret = -EINVAL;
355 goto err;
356 }
357
358 /* First UNMAP block descriptor starts at 8 byte offset */
359 ptr = &buf[8];
360 pr_debug("UNMAP: Sub: %s Using dl: %u bd_dl: %u size: %u"
361 " ptr: %p\n", dev->transport->name, dl, bd_dl, size, ptr);
362
363 while (size >= 16) {
364 lba = get_unaligned_be64(&ptr[0]);
365 range = get_unaligned_be32(&ptr[8]);
366 pr_debug("UNMAP: Using lba: %llu and range: %u\n",
367 (unsigned long long)lba, range);
368
369 if (range > dev->se_sub_dev->se_dev_attrib.max_unmap_lba_count) {
370 cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
371 ret = -EINVAL;
372 goto err;
373 }
374
375 if (lba + range > dev->transport->get_blocks(dev) + 1) {
376 cmd->scsi_sense_reason = TCM_ADDRESS_OUT_OF_RANGE;
377 ret = -EINVAL;
378 goto err;
379 }
380
381 ret = blkdev_issue_discard(ibd->ibd_bd, lba, range,
382 GFP_KERNEL, 0);
383 if (ret < 0) {
384 pr_err("blkdev_issue_discard() failed: %d\n",
385 ret);
386 goto err;
387 }
388
389 ptr += 16;
390 size -= 16;
391 }
392
393 err:
394 transport_kunmap_data_sg(cmd);
395 if (!ret)
396 target_complete_cmd(cmd, GOOD);
397 return ret;
398 }
399
400 static int iblock_execute_write_same(struct se_cmd *cmd)
401 {
402 struct iblock_dev *ibd = cmd->se_dev->dev_ptr;
403 int ret;
404
405 ret = blkdev_issue_discard(ibd->ibd_bd, cmd->t_task_lba,
406 spc_get_write_same_sectors(cmd), GFP_KERNEL,
407 0);
408 if (ret < 0) {
409 pr_debug("blkdev_issue_discard() failed for WRITE_SAME\n");
410 return ret;
411 }
412
413 target_complete_cmd(cmd, GOOD);
414 return 0;
415 }
416
417 enum {
418 Opt_udev_path, Opt_readonly, Opt_force, Opt_err
419 };
420
421 static match_table_t tokens = {
422 {Opt_udev_path, "udev_path=%s"},
423 {Opt_readonly, "readonly=%d"},
424 {Opt_force, "force=%d"},
425 {Opt_err, NULL}
426 };
427
428 static ssize_t iblock_set_configfs_dev_params(struct se_hba *hba,
429 struct se_subsystem_dev *se_dev,
430 const char *page, ssize_t count)
431 {
432 struct iblock_dev *ib_dev = se_dev->se_dev_su_ptr;
433 char *orig, *ptr, *arg_p, *opts;
434 substring_t args[MAX_OPT_ARGS];
435 int ret = 0, token;
436 unsigned long tmp_readonly;
437
438 opts = kstrdup(page, GFP_KERNEL);
439 if (!opts)
440 return -ENOMEM;
441
442 orig = opts;
443
444 while ((ptr = strsep(&opts, ",\n")) != NULL) {
445 if (!*ptr)
446 continue;
447
448 token = match_token(ptr, tokens, args);
449 switch (token) {
450 case Opt_udev_path:
451 if (ib_dev->ibd_bd) {
452 pr_err("Unable to set udev_path= while"
453 " ib_dev->ibd_bd exists\n");
454 ret = -EEXIST;
455 goto out;
456 }
457 if (match_strlcpy(ib_dev->ibd_udev_path, &args[0],
458 SE_UDEV_PATH_LEN) == 0) {
459 ret = -EINVAL;
460 break;
461 }
462 pr_debug("IBLOCK: Referencing UDEV path: %s\n",
463 ib_dev->ibd_udev_path);
464 ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH;
465 break;
466 case Opt_readonly:
467 arg_p = match_strdup(&args[0]);
468 if (!arg_p) {
469 ret = -ENOMEM;
470 break;
471 }
472 ret = strict_strtoul(arg_p, 0, &tmp_readonly);
473 kfree(arg_p);
474 if (ret < 0) {
475 pr_err("strict_strtoul() failed for"
476 " readonly=\n");
477 goto out;
478 }
479 ib_dev->ibd_readonly = tmp_readonly;
480 pr_debug("IBLOCK: readonly: %d\n", ib_dev->ibd_readonly);
481 break;
482 case Opt_force:
483 break;
484 default:
485 break;
486 }
487 }
488
489 out:
490 kfree(orig);
491 return (!ret) ? count : ret;
492 }
493
494 static ssize_t iblock_check_configfs_dev_params(
495 struct se_hba *hba,
496 struct se_subsystem_dev *se_dev)
497 {
498 struct iblock_dev *ibd = se_dev->se_dev_su_ptr;
499
500 if (!(ibd->ibd_flags & IBDF_HAS_UDEV_PATH)) {
501 pr_err("Missing udev_path= parameters for IBLOCK\n");
502 return -EINVAL;
503 }
504
505 return 0;
506 }
507
508 static ssize_t iblock_show_configfs_dev_params(
509 struct se_hba *hba,
510 struct se_subsystem_dev *se_dev,
511 char *b)
512 {
513 struct iblock_dev *ibd = se_dev->se_dev_su_ptr;
514 struct block_device *bd = ibd->ibd_bd;
515 char buf[BDEVNAME_SIZE];
516 ssize_t bl = 0;
517
518 if (bd)
519 bl += sprintf(b + bl, "iBlock device: %s",
520 bdevname(bd, buf));
521 if (ibd->ibd_flags & IBDF_HAS_UDEV_PATH)
522 bl += sprintf(b + bl, " UDEV PATH: %s",
523 ibd->ibd_udev_path);
524 bl += sprintf(b + bl, " readonly: %d\n", ibd->ibd_readonly);
525
526 bl += sprintf(b + bl, " ");
527 if (bd) {
528 bl += sprintf(b + bl, "Major: %d Minor: %d %s\n",
529 MAJOR(bd->bd_dev), MINOR(bd->bd_dev), (!bd->bd_contains) ?
530 "" : (bd->bd_holder == ibd) ?
531 "CLAIMED: IBLOCK" : "CLAIMED: OS");
532 } else {
533 bl += sprintf(b + bl, "Major: 0 Minor: 0\n");
534 }
535
536 return bl;
537 }
538
539 static void iblock_complete_cmd(struct se_cmd *cmd)
540 {
541 struct iblock_req *ibr = cmd->priv;
542 u8 status;
543
544 if (!atomic_dec_and_test(&ibr->pending))
545 return;
546
547 if (atomic_read(&ibr->ib_bio_err_cnt))
548 status = SAM_STAT_CHECK_CONDITION;
549 else
550 status = SAM_STAT_GOOD;
551
552 target_complete_cmd(cmd, status);
553 kfree(ibr);
554 }
555
556 static void iblock_bio_destructor(struct bio *bio)
557 {
558 struct se_cmd *cmd = bio->bi_private;
559 struct iblock_dev *ib_dev = cmd->se_dev->dev_ptr;
560
561 bio_free(bio, ib_dev->ibd_bio_set);
562 }
563
564 static struct bio *
565 iblock_get_bio(struct se_cmd *cmd, sector_t lba, u32 sg_num)
566 {
567 struct iblock_dev *ib_dev = cmd->se_dev->dev_ptr;
568 struct bio *bio;
569
570 /*
571 * Only allocate as many vector entries as the bio code allows us to,
572 * we'll loop later on until we have handled the whole request.
573 */
574 if (sg_num > BIO_MAX_PAGES)
575 sg_num = BIO_MAX_PAGES;
576
577 bio = bio_alloc_bioset(GFP_NOIO, sg_num, ib_dev->ibd_bio_set);
578 if (!bio) {
579 pr_err("Unable to allocate memory for bio\n");
580 return NULL;
581 }
582
583 bio->bi_bdev = ib_dev->ibd_bd;
584 bio->bi_private = cmd;
585 bio->bi_destructor = iblock_bio_destructor;
586 bio->bi_end_io = &iblock_bio_done;
587 bio->bi_sector = lba;
588 return bio;
589 }
590
591 static void iblock_submit_bios(struct bio_list *list, int rw)
592 {
593 struct blk_plug plug;
594 struct bio *bio;
595
596 blk_start_plug(&plug);
597 while ((bio = bio_list_pop(list)))
598 submit_bio(rw, bio);
599 blk_finish_plug(&plug);
600 }
601
602 static int iblock_execute_rw(struct se_cmd *cmd)
603 {
604 struct scatterlist *sgl = cmd->t_data_sg;
605 u32 sgl_nents = cmd->t_data_nents;
606 enum dma_data_direction data_direction = cmd->data_direction;
607 struct se_device *dev = cmd->se_dev;
608 struct iblock_req *ibr;
609 struct bio *bio;
610 struct bio_list list;
611 struct scatterlist *sg;
612 u32 sg_num = sgl_nents;
613 sector_t block_lba;
614 unsigned bio_cnt;
615 int rw;
616 int i;
617
618 if (data_direction == DMA_TO_DEVICE) {
619 /*
620 * Force data to disk if we pretend to not have a volatile
621 * write cache, or the initiator set the Force Unit Access bit.
622 */
623 if (dev->se_sub_dev->se_dev_attrib.emulate_write_cache == 0 ||
624 (dev->se_sub_dev->se_dev_attrib.emulate_fua_write > 0 &&
625 (cmd->se_cmd_flags & SCF_FUA)))
626 rw = WRITE_FUA;
627 else
628 rw = WRITE;
629 } else {
630 rw = READ;
631 }
632
633 /*
634 * Convert the blocksize advertised to the initiator to the 512 byte
635 * units unconditionally used by the Linux block layer.
636 */
637 if (dev->se_sub_dev->se_dev_attrib.block_size == 4096)
638 block_lba = (cmd->t_task_lba << 3);
639 else if (dev->se_sub_dev->se_dev_attrib.block_size == 2048)
640 block_lba = (cmd->t_task_lba << 2);
641 else if (dev->se_sub_dev->se_dev_attrib.block_size == 1024)
642 block_lba = (cmd->t_task_lba << 1);
643 else if (dev->se_sub_dev->se_dev_attrib.block_size == 512)
644 block_lba = cmd->t_task_lba;
645 else {
646 pr_err("Unsupported SCSI -> BLOCK LBA conversion:"
647 " %u\n", dev->se_sub_dev->se_dev_attrib.block_size);
648 cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
649 return -ENOSYS;
650 }
651
652 ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
653 if (!ibr)
654 goto fail;
655 cmd->priv = ibr;
656
657 if (!sgl_nents) {
658 atomic_set(&ibr->pending, 1);
659 iblock_complete_cmd(cmd);
660 return 0;
661 }
662
663 bio = iblock_get_bio(cmd, block_lba, sgl_nents);
664 if (!bio)
665 goto fail_free_ibr;
666
667 bio_list_init(&list);
668 bio_list_add(&list, bio);
669
670 atomic_set(&ibr->pending, 2);
671 bio_cnt = 1;
672
673 for_each_sg(sgl, sg, sgl_nents, i) {
674 /*
675 * XXX: if the length the device accepts is shorter than the
676 * length of the S/G list entry this will cause and
677 * endless loop. Better hope no driver uses huge pages.
678 */
679 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
680 != sg->length) {
681 if (bio_cnt >= IBLOCK_MAX_BIO_PER_TASK) {
682 iblock_submit_bios(&list, rw);
683 bio_cnt = 0;
684 }
685
686 bio = iblock_get_bio(cmd, block_lba, sg_num);
687 if (!bio)
688 goto fail_put_bios;
689
690 atomic_inc(&ibr->pending);
691 bio_list_add(&list, bio);
692 bio_cnt++;
693 }
694
695 /* Always in 512 byte units for Linux/Block */
696 block_lba += sg->length >> IBLOCK_LBA_SHIFT;
697 sg_num--;
698 }
699
700 iblock_submit_bios(&list, rw);
701 iblock_complete_cmd(cmd);
702 return 0;
703
704 fail_put_bios:
705 while ((bio = bio_list_pop(&list)))
706 bio_put(bio);
707 fail_free_ibr:
708 kfree(ibr);
709 cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
710 fail:
711 return -ENOMEM;
712 }
713
714 static u32 iblock_get_device_rev(struct se_device *dev)
715 {
716 return SCSI_SPC_2; /* Returns SPC-3 in Initiator Data */
717 }
718
719 static u32 iblock_get_device_type(struct se_device *dev)
720 {
721 return TYPE_DISK;
722 }
723
724 static sector_t iblock_get_blocks(struct se_device *dev)
725 {
726 struct iblock_dev *ibd = dev->dev_ptr;
727 struct block_device *bd = ibd->ibd_bd;
728 struct request_queue *q = bdev_get_queue(bd);
729
730 return iblock_emulate_read_cap_with_block_size(dev, bd, q);
731 }
732
733 static void iblock_bio_done(struct bio *bio, int err)
734 {
735 struct se_cmd *cmd = bio->bi_private;
736 struct iblock_req *ibr = cmd->priv;
737
738 /*
739 * Set -EIO if !BIO_UPTODATE and the passed is still err=0
740 */
741 if (!test_bit(BIO_UPTODATE, &bio->bi_flags) && !err)
742 err = -EIO;
743
744 if (err != 0) {
745 pr_err("test_bit(BIO_UPTODATE) failed for bio: %p,"
746 " err: %d\n", bio, err);
747 /*
748 * Bump the ib_bio_err_cnt and release bio.
749 */
750 atomic_inc(&ibr->ib_bio_err_cnt);
751 smp_mb__after_atomic_inc();
752 }
753
754 bio_put(bio);
755
756 iblock_complete_cmd(cmd);
757 }
758
759 static struct spc_ops iblock_spc_ops = {
760 .execute_rw = iblock_execute_rw,
761 .execute_sync_cache = iblock_execute_sync_cache,
762 .execute_write_same = iblock_execute_write_same,
763 .execute_unmap = iblock_execute_unmap,
764 };
765
766 static int iblock_parse_cdb(struct se_cmd *cmd)
767 {
768 return sbc_parse_cdb(cmd, &iblock_spc_ops);
769 }
770
771 static struct se_subsystem_api iblock_template = {
772 .name = "iblock",
773 .owner = THIS_MODULE,
774 .transport_type = TRANSPORT_PLUGIN_VHBA_PDEV,
775 .attach_hba = iblock_attach_hba,
776 .detach_hba = iblock_detach_hba,
777 .allocate_virtdevice = iblock_allocate_virtdevice,
778 .create_virtdevice = iblock_create_virtdevice,
779 .free_device = iblock_free_device,
780 .parse_cdb = iblock_parse_cdb,
781 .check_configfs_dev_params = iblock_check_configfs_dev_params,
782 .set_configfs_dev_params = iblock_set_configfs_dev_params,
783 .show_configfs_dev_params = iblock_show_configfs_dev_params,
784 .get_device_rev = iblock_get_device_rev,
785 .get_device_type = iblock_get_device_type,
786 .get_blocks = iblock_get_blocks,
787 };
788
789 static int __init iblock_module_init(void)
790 {
791 return transport_subsystem_register(&iblock_template);
792 }
793
794 static void iblock_module_exit(void)
795 {
796 transport_subsystem_release(&iblock_template);
797 }
798
799 MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin");
800 MODULE_AUTHOR("nab@Linux-iSCSI.org");
801 MODULE_LICENSE("GPL");
802
803 module_init(iblock_module_init);
804 module_exit(iblock_module_exit);
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