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[deliverable/linux.git] / drivers / target / target_core_iblock.c
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 <scsi/scsi.h>
41 #include <scsi/scsi_host.h>
42
43 #include <target/target_core_base.h>
44 #include <target/target_core_device.h>
45 #include <target/target_core_transport.h>
46
47 #include "target_core_iblock.h"
48
49 static struct se_subsystem_api iblock_template;
50
51 static void iblock_bio_done(struct bio *, int);
52
53 /* iblock_attach_hba(): (Part of se_subsystem_api_t template)
54 *
55 *
56 */
57 static int iblock_attach_hba(struct se_hba *hba, u32 host_id)
58 {
59 struct iblock_hba *ib_host;
60
61 ib_host = kzalloc(sizeof(struct iblock_hba), GFP_KERNEL);
62 if (!ib_host) {
63 pr_err("Unable to allocate memory for"
64 " struct iblock_hba\n");
65 return -ENOMEM;
66 }
67
68 ib_host->iblock_host_id = host_id;
69
70 hba->hba_ptr = ib_host;
71
72 pr_debug("CORE_HBA[%d] - TCM iBlock HBA Driver %s on"
73 " Generic Target Core Stack %s\n", hba->hba_id,
74 IBLOCK_VERSION, TARGET_CORE_MOD_VERSION);
75
76 pr_debug("CORE_HBA[%d] - Attached iBlock HBA: %u to Generic\n",
77 hba->hba_id, ib_host->iblock_host_id);
78
79 return 0;
80 }
81
82 static void iblock_detach_hba(struct se_hba *hba)
83 {
84 struct iblock_hba *ib_host = hba->hba_ptr;
85
86 pr_debug("CORE_HBA[%d] - Detached iBlock HBA: %u from Generic"
87 " Target Core\n", hba->hba_id, ib_host->iblock_host_id);
88
89 kfree(ib_host);
90 hba->hba_ptr = NULL;
91 }
92
93 static void *iblock_allocate_virtdevice(struct se_hba *hba, const char *name)
94 {
95 struct iblock_dev *ib_dev = NULL;
96 struct iblock_hba *ib_host = hba->hba_ptr;
97
98 ib_dev = kzalloc(sizeof(struct iblock_dev), GFP_KERNEL);
99 if (!ib_dev) {
100 pr_err("Unable to allocate struct iblock_dev\n");
101 return NULL;
102 }
103 ib_dev->ibd_host = ib_host;
104
105 pr_debug( "IBLOCK: Allocated ib_dev for %s\n", name);
106
107 return ib_dev;
108 }
109
110 static struct se_device *iblock_create_virtdevice(
111 struct se_hba *hba,
112 struct se_subsystem_dev *se_dev,
113 void *p)
114 {
115 struct iblock_dev *ib_dev = p;
116 struct se_device *dev;
117 struct se_dev_limits dev_limits;
118 struct block_device *bd = NULL;
119 struct request_queue *q;
120 struct queue_limits *limits;
121 u32 dev_flags = 0;
122 int ret = -EINVAL;
123
124 if (!ib_dev) {
125 pr_err("Unable to locate struct iblock_dev parameter\n");
126 return ERR_PTR(ret);
127 }
128 memset(&dev_limits, 0, sizeof(struct se_dev_limits));
129 /*
130 * These settings need to be made tunable..
131 */
132 ib_dev->ibd_bio_set = bioset_create(32, 64);
133 if (!ib_dev->ibd_bio_set) {
134 pr_err("IBLOCK: Unable to create bioset()\n");
135 return ERR_PTR(-ENOMEM);
136 }
137 pr_debug("IBLOCK: Created bio_set()\n");
138 /*
139 * iblock_check_configfs_dev_params() ensures that ib_dev->ibd_udev_path
140 * must already have been set in order for echo 1 > $HBA/$DEV/enable to run.
141 */
142 pr_debug( "IBLOCK: Claiming struct block_device: %s\n",
143 ib_dev->ibd_udev_path);
144
145 bd = blkdev_get_by_path(ib_dev->ibd_udev_path,
146 FMODE_WRITE|FMODE_READ|FMODE_EXCL, ib_dev);
147 if (IS_ERR(bd)) {
148 ret = PTR_ERR(bd);
149 goto failed;
150 }
151 /*
152 * Setup the local scope queue_limits from struct request_queue->limits
153 * to pass into transport_add_device_to_core_hba() as struct se_dev_limits.
154 */
155 q = bdev_get_queue(bd);
156 limits = &dev_limits.limits;
157 limits->logical_block_size = bdev_logical_block_size(bd);
158 limits->max_hw_sectors = queue_max_hw_sectors(q);
159 limits->max_sectors = queue_max_sectors(q);
160 dev_limits.hw_queue_depth = q->nr_requests;
161 dev_limits.queue_depth = q->nr_requests;
162
163 ib_dev->ibd_bd = bd;
164
165 dev = transport_add_device_to_core_hba(hba,
166 &iblock_template, se_dev, dev_flags, ib_dev,
167 &dev_limits, "IBLOCK", IBLOCK_VERSION);
168 if (!dev)
169 goto failed;
170
171 /*
172 * Check if the underlying struct block_device request_queue supports
173 * the QUEUE_FLAG_DISCARD bit for UNMAP/WRITE_SAME in SCSI + TRIM
174 * in ATA and we need to set TPE=1
175 */
176 if (blk_queue_discard(q)) {
177 dev->se_sub_dev->se_dev_attrib.max_unmap_lba_count =
178 q->limits.max_discard_sectors;
179 /*
180 * Currently hardcoded to 1 in Linux/SCSI code..
181 */
182 dev->se_sub_dev->se_dev_attrib.max_unmap_block_desc_count = 1;
183 dev->se_sub_dev->se_dev_attrib.unmap_granularity =
184 q->limits.discard_granularity;
185 dev->se_sub_dev->se_dev_attrib.unmap_granularity_alignment =
186 q->limits.discard_alignment;
187
188 pr_debug("IBLOCK: BLOCK Discard support available,"
189 " disabled by default\n");
190 }
191
192 if (blk_queue_nonrot(q))
193 dev->se_sub_dev->se_dev_attrib.is_nonrot = 1;
194
195 return dev;
196
197 failed:
198 if (ib_dev->ibd_bio_set) {
199 bioset_free(ib_dev->ibd_bio_set);
200 ib_dev->ibd_bio_set = NULL;
201 }
202 ib_dev->ibd_bd = NULL;
203 return ERR_PTR(ret);
204 }
205
206 static void iblock_free_device(void *p)
207 {
208 struct iblock_dev *ib_dev = p;
209
210 if (ib_dev->ibd_bd != NULL)
211 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
212 if (ib_dev->ibd_bio_set != NULL)
213 bioset_free(ib_dev->ibd_bio_set);
214 kfree(ib_dev);
215 }
216
217 static inline struct iblock_req *IBLOCK_REQ(struct se_task *task)
218 {
219 return container_of(task, struct iblock_req, ib_task);
220 }
221
222 static struct se_task *
223 iblock_alloc_task(unsigned char *cdb)
224 {
225 struct iblock_req *ib_req;
226
227 ib_req = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
228 if (!ib_req) {
229 pr_err("Unable to allocate memory for struct iblock_req\n");
230 return NULL;
231 }
232
233 atomic_set(&ib_req->ib_bio_cnt, 0);
234 return &ib_req->ib_task;
235 }
236
237 static unsigned long long iblock_emulate_read_cap_with_block_size(
238 struct se_device *dev,
239 struct block_device *bd,
240 struct request_queue *q)
241 {
242 unsigned long long blocks_long = (div_u64(i_size_read(bd->bd_inode),
243 bdev_logical_block_size(bd)) - 1);
244 u32 block_size = bdev_logical_block_size(bd);
245
246 if (block_size == dev->se_sub_dev->se_dev_attrib.block_size)
247 return blocks_long;
248
249 switch (block_size) {
250 case 4096:
251 switch (dev->se_sub_dev->se_dev_attrib.block_size) {
252 case 2048:
253 blocks_long <<= 1;
254 break;
255 case 1024:
256 blocks_long <<= 2;
257 break;
258 case 512:
259 blocks_long <<= 3;
260 default:
261 break;
262 }
263 break;
264 case 2048:
265 switch (dev->se_sub_dev->se_dev_attrib.block_size) {
266 case 4096:
267 blocks_long >>= 1;
268 break;
269 case 1024:
270 blocks_long <<= 1;
271 break;
272 case 512:
273 blocks_long <<= 2;
274 break;
275 default:
276 break;
277 }
278 break;
279 case 1024:
280 switch (dev->se_sub_dev->se_dev_attrib.block_size) {
281 case 4096:
282 blocks_long >>= 2;
283 break;
284 case 2048:
285 blocks_long >>= 1;
286 break;
287 case 512:
288 blocks_long <<= 1;
289 break;
290 default:
291 break;
292 }
293 break;
294 case 512:
295 switch (dev->se_sub_dev->se_dev_attrib.block_size) {
296 case 4096:
297 blocks_long >>= 3;
298 break;
299 case 2048:
300 blocks_long >>= 2;
301 break;
302 case 1024:
303 blocks_long >>= 1;
304 break;
305 default:
306 break;
307 }
308 break;
309 default:
310 break;
311 }
312
313 return blocks_long;
314 }
315
316 /*
317 * Emulate SYCHRONIZE_CACHE_*
318 */
319 static void iblock_emulate_sync_cache(struct se_task *task)
320 {
321 struct se_cmd *cmd = task->task_se_cmd;
322 struct iblock_dev *ib_dev = cmd->se_dev->dev_ptr;
323 int immed = (cmd->t_task_cdb[1] & 0x2);
324 sector_t error_sector;
325 int ret;
326
327 /*
328 * If the Immediate bit is set, queue up the GOOD response
329 * for this SYNCHRONIZE_CACHE op
330 */
331 if (immed)
332 transport_complete_sync_cache(cmd, 1);
333
334 /*
335 * blkdev_issue_flush() does not support a specifying a range, so
336 * we have to flush the entire cache.
337 */
338 ret = blkdev_issue_flush(ib_dev->ibd_bd, GFP_KERNEL, &error_sector);
339 if (ret != 0) {
340 pr_err("IBLOCK: block_issue_flush() failed: %d "
341 " error_sector: %llu\n", ret,
342 (unsigned long long)error_sector);
343 }
344
345 if (!immed)
346 transport_complete_sync_cache(cmd, ret == 0);
347 }
348
349 /*
350 * Tell TCM Core that we are capable of WriteCache emulation for
351 * an underlying struct se_device.
352 */
353 static int iblock_emulated_write_cache(struct se_device *dev)
354 {
355 return 1;
356 }
357
358 static int iblock_emulated_dpo(struct se_device *dev)
359 {
360 return 0;
361 }
362
363 /*
364 * Tell TCM Core that we will be emulating Forced Unit Access (FUA) for WRITEs
365 * for TYPE_DISK.
366 */
367 static int iblock_emulated_fua_write(struct se_device *dev)
368 {
369 return 1;
370 }
371
372 static int iblock_emulated_fua_read(struct se_device *dev)
373 {
374 return 0;
375 }
376
377 static int iblock_do_task(struct se_task *task)
378 {
379 struct se_device *dev = task->task_se_cmd->se_dev;
380 struct iblock_req *req = IBLOCK_REQ(task);
381 struct bio *bio = req->ib_bio, *nbio = NULL;
382 struct blk_plug plug;
383 int rw;
384
385 if (task->task_data_direction == DMA_TO_DEVICE) {
386 /*
387 * Force data to disk if we pretend to not have a volatile
388 * write cache, or the initiator set the Force Unit Access bit.
389 */
390 if (dev->se_sub_dev->se_dev_attrib.emulate_write_cache == 0 ||
391 (dev->se_sub_dev->se_dev_attrib.emulate_fua_write > 0 &&
392 task->task_se_cmd->t_tasks_fua))
393 rw = WRITE_FUA;
394 else
395 rw = WRITE;
396 } else {
397 rw = READ;
398 }
399
400 blk_start_plug(&plug);
401 while (bio) {
402 nbio = bio->bi_next;
403 bio->bi_next = NULL;
404 pr_debug("Calling submit_bio() task: %p bio: %p"
405 " bio->bi_sector: %llu\n", task, bio,
406 (unsigned long long)bio->bi_sector);
407
408 submit_bio(rw, bio);
409 bio = nbio;
410 }
411 blk_finish_plug(&plug);
412
413 return PYX_TRANSPORT_SENT_TO_TRANSPORT;
414 }
415
416 static int iblock_do_discard(struct se_device *dev, sector_t lba, u32 range)
417 {
418 struct iblock_dev *ibd = dev->dev_ptr;
419 struct block_device *bd = ibd->ibd_bd;
420 int barrier = 0;
421
422 return blkdev_issue_discard(bd, lba, range, GFP_KERNEL, barrier);
423 }
424
425 static void iblock_free_task(struct se_task *task)
426 {
427 struct iblock_req *req = IBLOCK_REQ(task);
428 struct bio *bio, *hbio = req->ib_bio;
429 /*
430 * We only release the bio(s) here if iblock_bio_done() has not called
431 * bio_put() -> iblock_bio_destructor().
432 */
433 while (hbio != NULL) {
434 bio = hbio;
435 hbio = hbio->bi_next;
436 bio->bi_next = NULL;
437 bio_put(bio);
438 }
439
440 kfree(req);
441 }
442
443 enum {
444 Opt_udev_path, Opt_force, Opt_err
445 };
446
447 static match_table_t tokens = {
448 {Opt_udev_path, "udev_path=%s"},
449 {Opt_force, "force=%d"},
450 {Opt_err, NULL}
451 };
452
453 static ssize_t iblock_set_configfs_dev_params(struct se_hba *hba,
454 struct se_subsystem_dev *se_dev,
455 const char *page, ssize_t count)
456 {
457 struct iblock_dev *ib_dev = se_dev->se_dev_su_ptr;
458 char *orig, *ptr, *arg_p, *opts;
459 substring_t args[MAX_OPT_ARGS];
460 int ret = 0, token;
461
462 opts = kstrdup(page, GFP_KERNEL);
463 if (!opts)
464 return -ENOMEM;
465
466 orig = opts;
467
468 while ((ptr = strsep(&opts, ",")) != NULL) {
469 if (!*ptr)
470 continue;
471
472 token = match_token(ptr, tokens, args);
473 switch (token) {
474 case Opt_udev_path:
475 if (ib_dev->ibd_bd) {
476 pr_err("Unable to set udev_path= while"
477 " ib_dev->ibd_bd exists\n");
478 ret = -EEXIST;
479 goto out;
480 }
481 arg_p = match_strdup(&args[0]);
482 if (!arg_p) {
483 ret = -ENOMEM;
484 break;
485 }
486 snprintf(ib_dev->ibd_udev_path, SE_UDEV_PATH_LEN,
487 "%s", arg_p);
488 kfree(arg_p);
489 pr_debug("IBLOCK: Referencing UDEV path: %s\n",
490 ib_dev->ibd_udev_path);
491 ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH;
492 break;
493 case Opt_force:
494 break;
495 default:
496 break;
497 }
498 }
499
500 out:
501 kfree(orig);
502 return (!ret) ? count : ret;
503 }
504
505 static ssize_t iblock_check_configfs_dev_params(
506 struct se_hba *hba,
507 struct se_subsystem_dev *se_dev)
508 {
509 struct iblock_dev *ibd = se_dev->se_dev_su_ptr;
510
511 if (!(ibd->ibd_flags & IBDF_HAS_UDEV_PATH)) {
512 pr_err("Missing udev_path= parameters for IBLOCK\n");
513 return -EINVAL;
514 }
515
516 return 0;
517 }
518
519 static ssize_t iblock_show_configfs_dev_params(
520 struct se_hba *hba,
521 struct se_subsystem_dev *se_dev,
522 char *b)
523 {
524 struct iblock_dev *ibd = se_dev->se_dev_su_ptr;
525 struct block_device *bd = ibd->ibd_bd;
526 char buf[BDEVNAME_SIZE];
527 ssize_t bl = 0;
528
529 if (bd)
530 bl += sprintf(b + bl, "iBlock device: %s",
531 bdevname(bd, buf));
532 if (ibd->ibd_flags & IBDF_HAS_UDEV_PATH) {
533 bl += sprintf(b + bl, " UDEV PATH: %s\n",
534 ibd->ibd_udev_path);
535 } else
536 bl += sprintf(b + bl, "\n");
537
538 bl += sprintf(b + bl, " ");
539 if (bd) {
540 bl += sprintf(b + bl, "Major: %d Minor: %d %s\n",
541 MAJOR(bd->bd_dev), MINOR(bd->bd_dev), (!bd->bd_contains) ?
542 "" : (bd->bd_holder == (struct iblock_dev *)ibd) ?
543 "CLAIMED: IBLOCK" : "CLAIMED: OS");
544 } else {
545 bl += sprintf(b + bl, "Major: 0 Minor: 0\n");
546 }
547
548 return bl;
549 }
550
551 static void iblock_bio_destructor(struct bio *bio)
552 {
553 struct se_task *task = bio->bi_private;
554 struct iblock_dev *ib_dev = task->se_dev->dev_ptr;
555
556 bio_free(bio, ib_dev->ibd_bio_set);
557 }
558
559 static struct bio *iblock_get_bio(
560 struct se_task *task,
561 struct iblock_req *ib_req,
562 struct iblock_dev *ib_dev,
563 int *ret,
564 sector_t lba,
565 u32 sg_num)
566 {
567 struct bio *bio;
568
569 bio = bio_alloc_bioset(GFP_NOIO, sg_num, ib_dev->ibd_bio_set);
570 if (!bio) {
571 pr_err("Unable to allocate memory for bio\n");
572 *ret = PYX_TRANSPORT_OUT_OF_MEMORY_RESOURCES;
573 return NULL;
574 }
575
576 pr_debug("Allocated bio: %p task_sg_nents: %u using ibd_bio_set:"
577 " %p\n", bio, task->task_sg_nents, ib_dev->ibd_bio_set);
578 pr_debug("Allocated bio: %p task_size: %u\n", bio, task->task_size);
579
580 bio->bi_bdev = ib_dev->ibd_bd;
581 bio->bi_private = task;
582 bio->bi_destructor = iblock_bio_destructor;
583 bio->bi_end_io = &iblock_bio_done;
584 bio->bi_sector = lba;
585 atomic_inc(&ib_req->ib_bio_cnt);
586
587 pr_debug("Set bio->bi_sector: %llu\n", (unsigned long long)bio->bi_sector);
588 pr_debug("Set ib_req->ib_bio_cnt: %d\n",
589 atomic_read(&ib_req->ib_bio_cnt));
590 return bio;
591 }
592
593 static int iblock_map_data_SG(struct se_task *task)
594 {
595 struct se_cmd *cmd = task->task_se_cmd;
596 struct se_device *dev = cmd->se_dev;
597 struct iblock_dev *ib_dev = task->se_dev->dev_ptr;
598 struct iblock_req *ib_req = IBLOCK_REQ(task);
599 struct bio *bio = NULL, *hbio = NULL, *tbio = NULL;
600 struct scatterlist *sg;
601 int ret = 0;
602 u32 i, sg_num = task->task_sg_nents;
603 sector_t block_lba;
604 /*
605 * Do starting conversion up from non 512-byte blocksize with
606 * struct se_task SCSI blocksize into Linux/Block 512 units for BIO.
607 */
608 if (dev->se_sub_dev->se_dev_attrib.block_size == 4096)
609 block_lba = (task->task_lba << 3);
610 else if (dev->se_sub_dev->se_dev_attrib.block_size == 2048)
611 block_lba = (task->task_lba << 2);
612 else if (dev->se_sub_dev->se_dev_attrib.block_size == 1024)
613 block_lba = (task->task_lba << 1);
614 else if (dev->se_sub_dev->se_dev_attrib.block_size == 512)
615 block_lba = task->task_lba;
616 else {
617 pr_err("Unsupported SCSI -> BLOCK LBA conversion:"
618 " %u\n", dev->se_sub_dev->se_dev_attrib.block_size);
619 return PYX_TRANSPORT_LU_COMM_FAILURE;
620 }
621
622 bio = iblock_get_bio(task, ib_req, ib_dev, &ret, block_lba, sg_num);
623 if (!bio)
624 return ret;
625
626 ib_req->ib_bio = bio;
627 hbio = tbio = bio;
628 /*
629 * Use fs/bio.c:bio_add_pages() to setup the bio_vec maplist
630 * from task->task_sg -> struct scatterlist memory.
631 */
632 for_each_sg(task->task_sg, sg, task->task_sg_nents, i) {
633 pr_debug("task: %p bio: %p Calling bio_add_page(): page:"
634 " %p len: %u offset: %u\n", task, bio, sg_page(sg),
635 sg->length, sg->offset);
636 again:
637 ret = bio_add_page(bio, sg_page(sg), sg->length, sg->offset);
638 if (ret != sg->length) {
639
640 pr_debug("*** Set bio->bi_sector: %llu\n",
641 (unsigned long long)bio->bi_sector);
642 pr_debug("** task->task_size: %u\n",
643 task->task_size);
644 pr_debug("*** bio->bi_max_vecs: %u\n",
645 bio->bi_max_vecs);
646 pr_debug("*** bio->bi_vcnt: %u\n",
647 bio->bi_vcnt);
648
649 bio = iblock_get_bio(task, ib_req, ib_dev, &ret,
650 block_lba, sg_num);
651 if (!bio)
652 goto fail;
653
654 tbio = tbio->bi_next = bio;
655 pr_debug("-----------------> Added +1 bio: %p to"
656 " list, Going to again\n", bio);
657 goto again;
658 }
659 /* Always in 512 byte units for Linux/Block */
660 block_lba += sg->length >> IBLOCK_LBA_SHIFT;
661 sg_num--;
662 pr_debug("task: %p bio-add_page() passed!, decremented"
663 " sg_num to %u\n", task, sg_num);
664 pr_debug("task: %p bio_add_page() passed!, increased lba"
665 " to %llu\n", task, (unsigned long long)block_lba);
666 pr_debug("task: %p bio_add_page() passed!, bio->bi_vcnt:"
667 " %u\n", task, bio->bi_vcnt);
668 }
669
670 return 0;
671 fail:
672 while (hbio) {
673 bio = hbio;
674 hbio = hbio->bi_next;
675 bio->bi_next = NULL;
676 bio_put(bio);
677 }
678 return ret;
679 }
680
681 static unsigned char *iblock_get_cdb(struct se_task *task)
682 {
683 return IBLOCK_REQ(task)->ib_scsi_cdb;
684 }
685
686 static u32 iblock_get_device_rev(struct se_device *dev)
687 {
688 return SCSI_SPC_2; /* Returns SPC-3 in Initiator Data */
689 }
690
691 static u32 iblock_get_device_type(struct se_device *dev)
692 {
693 return TYPE_DISK;
694 }
695
696 static sector_t iblock_get_blocks(struct se_device *dev)
697 {
698 struct iblock_dev *ibd = dev->dev_ptr;
699 struct block_device *bd = ibd->ibd_bd;
700 struct request_queue *q = bdev_get_queue(bd);
701
702 return iblock_emulate_read_cap_with_block_size(dev, bd, q);
703 }
704
705 static void iblock_bio_done(struct bio *bio, int err)
706 {
707 struct se_task *task = bio->bi_private;
708 struct iblock_req *ibr = IBLOCK_REQ(task);
709 /*
710 * Set -EIO if !BIO_UPTODATE and the passed is still err=0
711 */
712 if (!test_bit(BIO_UPTODATE, &bio->bi_flags) && !err)
713 err = -EIO;
714
715 if (err != 0) {
716 pr_err("test_bit(BIO_UPTODATE) failed for bio: %p,"
717 " err: %d\n", bio, err);
718 /*
719 * Bump the ib_bio_err_cnt and release bio.
720 */
721 atomic_inc(&ibr->ib_bio_err_cnt);
722 smp_mb__after_atomic_inc();
723 bio_put(bio);
724 /*
725 * Wait to complete the task until the last bio as completed.
726 */
727 if (!atomic_dec_and_test(&ibr->ib_bio_cnt))
728 return;
729
730 ibr->ib_bio = NULL;
731 transport_complete_task(task, 0);
732 return;
733 }
734 pr_debug("done[%p] bio: %p task_lba: %llu bio_lba: %llu err=%d\n",
735 task, bio, task->task_lba, (unsigned long long)bio->bi_sector, err);
736 /*
737 * bio_put() will call iblock_bio_destructor() to release the bio back
738 * to ibr->ib_bio_set.
739 */
740 bio_put(bio);
741 /*
742 * Wait to complete the task until the last bio as completed.
743 */
744 if (!atomic_dec_and_test(&ibr->ib_bio_cnt))
745 return;
746 /*
747 * Return GOOD status for task if zero ib_bio_err_cnt exists.
748 */
749 ibr->ib_bio = NULL;
750 transport_complete_task(task, (!atomic_read(&ibr->ib_bio_err_cnt)));
751 }
752
753 static struct se_subsystem_api iblock_template = {
754 .name = "iblock",
755 .owner = THIS_MODULE,
756 .transport_type = TRANSPORT_PLUGIN_VHBA_PDEV,
757 .map_data_SG = iblock_map_data_SG,
758 .attach_hba = iblock_attach_hba,
759 .detach_hba = iblock_detach_hba,
760 .allocate_virtdevice = iblock_allocate_virtdevice,
761 .create_virtdevice = iblock_create_virtdevice,
762 .free_device = iblock_free_device,
763 .dpo_emulated = iblock_emulated_dpo,
764 .fua_write_emulated = iblock_emulated_fua_write,
765 .fua_read_emulated = iblock_emulated_fua_read,
766 .write_cache_emulated = iblock_emulated_write_cache,
767 .alloc_task = iblock_alloc_task,
768 .do_task = iblock_do_task,
769 .do_discard = iblock_do_discard,
770 .do_sync_cache = iblock_emulate_sync_cache,
771 .free_task = iblock_free_task,
772 .check_configfs_dev_params = iblock_check_configfs_dev_params,
773 .set_configfs_dev_params = iblock_set_configfs_dev_params,
774 .show_configfs_dev_params = iblock_show_configfs_dev_params,
775 .get_cdb = iblock_get_cdb,
776 .get_device_rev = iblock_get_device_rev,
777 .get_device_type = iblock_get_device_type,
778 .get_blocks = iblock_get_blocks,
779 };
780
781 static int __init iblock_module_init(void)
782 {
783 return transport_subsystem_register(&iblock_template);
784 }
785
786 static void iblock_module_exit(void)
787 {
788 transport_subsystem_release(&iblock_template);
789 }
790
791 MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin");
792 MODULE_AUTHOR("nab@Linux-iSCSI.org");
793 MODULE_LICENSE("GPL");
794
795 module_init(iblock_module_init);
796 module_exit(iblock_module_exit);
Linux kernel - Deliverables
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