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Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux...
[linux-btrfs-devel.git] / drivers / target / target_core_iblock.c
blob7e12341054426404ddd010d793450ca5ac0d7265
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
50 static struct se_subsystem_api iblock_template;
51
52 static void iblock_bio_done(struct bio *, int);
53
54 /* iblock_attach_hba(): (Part of se_subsystem_api_t template)
55 *
56 *
57 */
58 static 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
83 static 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
94 static 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
111 static 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
198 failed:
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
207 static 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
218 static inline struct iblock_req *IBLOCK_REQ(struct se_task *task)
219 {
220 return container_of(task, struct iblock_req, ib_task);
221 }
222
223 static struct se_task *
224 iblock_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
238 static 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 */
320 static 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 */
354 static int iblock_emulated_write_cache(struct se_device *dev)
355 {
356 return 1;
357 }
358
359 static 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 */
368 static int iblock_emulated_fua_write(struct se_device *dev)
369 {
370 return 1;
371 }
372
373 static int iblock_emulated_fua_read(struct se_device *dev)
374 {
375 return 0;
376 }
377
378 static 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
417 static 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
426 static 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
444 enum {
445 Opt_udev_path, Opt_force, Opt_err
446 };
447
448 static match_table_t tokens = {
449 {Opt_udev_path, "udev_path=%s"},
450 {Opt_force, "force=%d"},
451 {Opt_err, NULL}
452 };
453
454 static 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
501 out:
502 kfree(orig);
503 return (!ret) ? count : ret;
504 }
505
506 static 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
520 static 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
552 static 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
560 static 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
594 static 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);
637 again:
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;
672 fail:
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
682 static unsigned char *iblock_get_cdb(struct se_task *task)
683 {
684 return IBLOCK_REQ(task)->ib_scsi_cdb;
685 }
686
687 static u32 iblock_get_device_rev(struct se_device *dev)
688 {
689 return SCSI_SPC_2; /* Returns SPC-3 in Initiator Data */
690 }
691
692 static u32 iblock_get_device_type(struct se_device *dev)
693 {
694 return TYPE_DISK;
695 }
696
697 static 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
706 static 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
754 static 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
782 static int __init iblock_module_init(void)
783 {
784 return transport_subsystem_register(&iblock_template);
785 }
786
787 static void iblock_module_exit(void)
788 {
789 transport_subsystem_release(&iblock_template);
790 }
791
792 MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin");
793 MODULE_AUTHOR("nab@Linux-iSCSI.org");
794 MODULE_LICENSE("GPL");
795
796 module_init(iblock_module_init);
797 module_exit(iblock_module_exit);
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