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1/*******************************************************************************
2 * Filename: target_core_iblock.c
3 *
4 * This file contains the Storage Engine <-> Linux BlockIO transport
5 * specific functions.
6 *
7 * 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);
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
44#include <target/target_core_base.h>
45#include <target/target_core_backend.h>
46
47#include "target_core_iblock.h"
48
49#define IBLOCK_MAX_BIO_PER_TASK 32 /* max # of bios to submit at a time */
50#define IBLOCK_BIO_POOL_SIZE 128
51
52static struct se_subsystem_api iblock_template;
53
54static void iblock_bio_done(struct bio *, int);
55
56/* iblock_attach_hba(): (Part of se_subsystem_api_t template)
57 *
58 *
59 */
60static int iblock_attach_hba(struct se_hba *hba, u32 host_id)
61{
62 pr_debug("CORE_HBA[%d] - TCM iBlock HBA Driver %s on"
63 " Generic Target Core Stack %s\n", hba->hba_id,
64 IBLOCK_VERSION, TARGET_CORE_MOD_VERSION);
65 return 0;
66}
67
68static void iblock_detach_hba(struct se_hba *hba)
69{
70}
71
72static void *iblock_allocate_virtdevice(struct se_hba *hba, const char *name)
73{
74 struct iblock_dev *ib_dev = NULL;
75
76 ib_dev = kzalloc(sizeof(struct iblock_dev), GFP_KERNEL);
77 if (!ib_dev) {
78 pr_err("Unable to allocate struct iblock_dev\n");
79 return NULL;
80 }
81
82 pr_debug( "IBLOCK: Allocated ib_dev for %s\n", name);
83
84 return ib_dev;
85}
86
87static struct se_device *iblock_create_virtdevice(
88 struct se_hba *hba,
89 struct se_subsystem_dev *se_dev,
90 void *p)
91{
92 struct iblock_dev *ib_dev = p;
93 struct se_device *dev;
94 struct se_dev_limits dev_limits;
95 struct block_device *bd = NULL;
96 struct request_queue *q;
97 struct queue_limits *limits;
98 u32 dev_flags = 0;
99 int ret = -EINVAL;
100
101 if (!ib_dev) {
102 pr_err("Unable to locate struct iblock_dev parameter\n");
103 return ERR_PTR(ret);
104 }
105 memset(&dev_limits, 0, sizeof(struct se_dev_limits));
106
107 ib_dev->ibd_bio_set = bioset_create(IBLOCK_BIO_POOL_SIZE, 0);
108 if (!ib_dev->ibd_bio_set) {
109 pr_err("IBLOCK: Unable to create bioset()\n");
110 return ERR_PTR(-ENOMEM);
111 }
112 pr_debug("IBLOCK: Created bio_set()\n");
113 /*
114 * iblock_check_configfs_dev_params() ensures that ib_dev->ibd_udev_path
115 * must already have been set in order for echo 1 > $HBA/$DEV/enable to run.
116 */
117 pr_debug( "IBLOCK: Claiming struct block_device: %s\n",
118 ib_dev->ibd_udev_path);
119
120 bd = blkdev_get_by_path(ib_dev->ibd_udev_path,
121 FMODE_WRITE|FMODE_READ|FMODE_EXCL, ib_dev);
122 if (IS_ERR(bd)) {
123 ret = PTR_ERR(bd);
124 goto failed;
125 }
126 /*
127 * Setup the local scope queue_limits from struct request_queue->limits
128 * to pass into transport_add_device_to_core_hba() as struct se_dev_limits.
129 */
130 q = bdev_get_queue(bd);
131 limits = &dev_limits.limits;
132 limits->logical_block_size = bdev_logical_block_size(bd);
133 limits->max_hw_sectors = UINT_MAX;
134 limits->max_sectors = UINT_MAX;
135 dev_limits.hw_queue_depth = q->nr_requests;
136 dev_limits.queue_depth = q->nr_requests;
137
138 ib_dev->ibd_bd = bd;
139
140 dev = transport_add_device_to_core_hba(hba,
141 &iblock_template, se_dev, dev_flags, ib_dev,
142 &dev_limits, "IBLOCK", IBLOCK_VERSION);
143 if (!dev)
144 goto failed;
145
146 /*
147 * Check if the underlying struct block_device request_queue supports
148 * the QUEUE_FLAG_DISCARD bit for UNMAP/WRITE_SAME in SCSI + TRIM
149 * in ATA and we need to set TPE=1
150 */
151 if (blk_queue_discard(q)) {
152 dev->se_sub_dev->se_dev_attrib.max_unmap_lba_count =
153 q->limits.max_discard_sectors;
154 /*
155 * Currently hardcoded to 1 in Linux/SCSI code..
156 */
157 dev->se_sub_dev->se_dev_attrib.max_unmap_block_desc_count = 1;
158 dev->se_sub_dev->se_dev_attrib.unmap_granularity =
159 q->limits.discard_granularity >> 9;
160 dev->se_sub_dev->se_dev_attrib.unmap_granularity_alignment =
161 q->limits.discard_alignment;
162
163 pr_debug("IBLOCK: BLOCK Discard support available,"
164 " disabled by default\n");
165 }
166
167 if (blk_queue_nonrot(q))
168 dev->se_sub_dev->se_dev_attrib.is_nonrot = 1;
169
170 return dev;
171
172failed:
173 if (ib_dev->ibd_bio_set) {
174 bioset_free(ib_dev->ibd_bio_set);
175 ib_dev->ibd_bio_set = NULL;
176 }
177 ib_dev->ibd_bd = NULL;
178 return ERR_PTR(ret);
179}
180
181static void iblock_free_device(void *p)
182{
183 struct iblock_dev *ib_dev = p;
184
185 if (ib_dev->ibd_bd != NULL)
186 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
187 if (ib_dev->ibd_bio_set != NULL)
188 bioset_free(ib_dev->ibd_bio_set);
189 kfree(ib_dev);
190}
191
192static unsigned long long iblock_emulate_read_cap_with_block_size(
193 struct se_device *dev,
194 struct block_device *bd,
195 struct request_queue *q)
196{
197 unsigned long long blocks_long = (div_u64(i_size_read(bd->bd_inode),
198 bdev_logical_block_size(bd)) - 1);
199 u32 block_size = bdev_logical_block_size(bd);
200
201 if (block_size == dev->se_sub_dev->se_dev_attrib.block_size)
202 return blocks_long;
203
204 switch (block_size) {
205 case 4096:
206 switch (dev->se_sub_dev->se_dev_attrib.block_size) {
207 case 2048:
208 blocks_long <<= 1;
209 break;
210 case 1024:
211 blocks_long <<= 2;
212 break;
213 case 512:
214 blocks_long <<= 3;
215 default:
216 break;
217 }
218 break;
219 case 2048:
220 switch (dev->se_sub_dev->se_dev_attrib.block_size) {
221 case 4096:
222 blocks_long >>= 1;
223 break;
224 case 1024:
225 blocks_long <<= 1;
226 break;
227 case 512:
228 blocks_long <<= 2;
229 break;
230 default:
231 break;
232 }
233 break;
234 case 1024:
235 switch (dev->se_sub_dev->se_dev_attrib.block_size) {
236 case 4096:
237 blocks_long >>= 2;
238 break;
239 case 2048:
240 blocks_long >>= 1;
241 break;
242 case 512:
243 blocks_long <<= 1;
244 break;
245 default:
246 break;
247 }
248 break;
249 case 512:
250 switch (dev->se_sub_dev->se_dev_attrib.block_size) {
251 case 4096:
252 blocks_long >>= 3;
253 break;
254 case 2048:
255 blocks_long >>= 2;
256 break;
257 case 1024:
258 blocks_long >>= 1;
259 break;
260 default:
261 break;
262 }
263 break;
264 default:
265 break;
266 }
267
268 return blocks_long;
269}
270
271static void iblock_end_io_flush(struct bio *bio, int err)
272{
273 struct se_cmd *cmd = bio->bi_private;
274
275 if (err)
276 pr_err("IBLOCK: cache flush failed: %d\n", err);
277
278 if (cmd) {
279 if (err) {
280 cmd->scsi_sense_reason =
281 TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
282 target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
283 } else {
284 target_complete_cmd(cmd, SAM_STAT_GOOD);
285 }
286 }
287
288 bio_put(bio);
289}
290
291/*
292 * Implement SYCHRONIZE CACHE. Note that we can't handle lba ranges and must
293 * always flush the whole cache.
294 */
295static void iblock_emulate_sync_cache(struct se_cmd *cmd)
296{
297 struct iblock_dev *ib_dev = cmd->se_dev->dev_ptr;
298 int immed = (cmd->t_task_cdb[1] & 0x2);
299 struct bio *bio;
300
301 /*
302 * If the Immediate bit is set, queue up the GOOD response
303 * for this SYNCHRONIZE_CACHE op.
304 */
305 if (immed)
306 target_complete_cmd(cmd, SAM_STAT_GOOD);
307
308 bio = bio_alloc(GFP_KERNEL, 0);
309 bio->bi_end_io = iblock_end_io_flush;
310 bio->bi_bdev = ib_dev->ibd_bd;
311 if (!immed)
312 bio->bi_private = cmd;
313 submit_bio(WRITE_FLUSH, bio);
314}
315
316static int iblock_do_discard(struct se_device *dev, sector_t lba, u32 range)
317{
318 struct iblock_dev *ibd = dev->dev_ptr;
319 struct block_device *bd = ibd->ibd_bd;
320 int barrier = 0;
321
322 return blkdev_issue_discard(bd, lba, range, GFP_KERNEL, barrier);
323}
324
325enum {
326 Opt_udev_path, Opt_force, Opt_err
327};
328
329static match_table_t tokens = {
330 {Opt_udev_path, "udev_path=%s"},
331 {Opt_force, "force=%d"},
332 {Opt_err, NULL}
333};
334
335static ssize_t iblock_set_configfs_dev_params(struct se_hba *hba,
336 struct se_subsystem_dev *se_dev,
337 const char *page, ssize_t count)
338{
339 struct iblock_dev *ib_dev = se_dev->se_dev_su_ptr;
340 char *orig, *ptr, *arg_p, *opts;
341 substring_t args[MAX_OPT_ARGS];
342 int ret = 0, token;
343
344 opts = kstrdup(page, GFP_KERNEL);
345 if (!opts)
346 return -ENOMEM;
347
348 orig = opts;
349
350 while ((ptr = strsep(&opts, ",\n")) != NULL) {
351 if (!*ptr)
352 continue;
353
354 token = match_token(ptr, tokens, args);
355 switch (token) {
356 case Opt_udev_path:
357 if (ib_dev->ibd_bd) {
358 pr_err("Unable to set udev_path= while"
359 " ib_dev->ibd_bd exists\n");
360 ret = -EEXIST;
361 goto out;
362 }
363 arg_p = match_strdup(&args[0]);
364 if (!arg_p) {
365 ret = -ENOMEM;
366 break;
367 }
368 snprintf(ib_dev->ibd_udev_path, SE_UDEV_PATH_LEN,
369 "%s", arg_p);
370 kfree(arg_p);
371 pr_debug("IBLOCK: Referencing UDEV path: %s\n",
372 ib_dev->ibd_udev_path);
373 ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH;
374 break;
375 case Opt_force:
376 break;
377 default:
378 break;
379 }
380 }
381
382out:
383 kfree(orig);
384 return (!ret) ? count : ret;
385}
386
387static ssize_t iblock_check_configfs_dev_params(
388 struct se_hba *hba,
389 struct se_subsystem_dev *se_dev)
390{
391 struct iblock_dev *ibd = se_dev->se_dev_su_ptr;
392
393 if (!(ibd->ibd_flags & IBDF_HAS_UDEV_PATH)) {
394 pr_err("Missing udev_path= parameters for IBLOCK\n");
395 return -EINVAL;
396 }
397
398 return 0;
399}
400
401static ssize_t iblock_show_configfs_dev_params(
402 struct se_hba *hba,
403 struct se_subsystem_dev *se_dev,
404 char *b)
405{
406 struct iblock_dev *ibd = se_dev->se_dev_su_ptr;
407 struct block_device *bd = ibd->ibd_bd;
408 char buf[BDEVNAME_SIZE];
409 ssize_t bl = 0;
410
411 if (bd)
412 bl += sprintf(b + bl, "iBlock device: %s",
413 bdevname(bd, buf));
414 if (ibd->ibd_flags & IBDF_HAS_UDEV_PATH) {
415 bl += sprintf(b + bl, " UDEV PATH: %s\n",
416 ibd->ibd_udev_path);
417 } else
418 bl += sprintf(b + bl, "\n");
419
420 bl += sprintf(b + bl, " ");
421 if (bd) {
422 bl += sprintf(b + bl, "Major: %d Minor: %d %s\n",
423 MAJOR(bd->bd_dev), MINOR(bd->bd_dev), (!bd->bd_contains) ?
424 "" : (bd->bd_holder == ibd) ?
425 "CLAIMED: IBLOCK" : "CLAIMED: OS");
426 } else {
427 bl += sprintf(b + bl, "Major: 0 Minor: 0\n");
428 }
429
430 return bl;
431}
432
433static void iblock_complete_cmd(struct se_cmd *cmd)
434{
435 struct iblock_req *ibr = cmd->priv;
436 u8 status;
437
438 if (!atomic_dec_and_test(&ibr->pending))
439 return;
440
441 if (atomic_read(&ibr->ib_bio_err_cnt))
442 status = SAM_STAT_CHECK_CONDITION;
443 else
444 status = SAM_STAT_GOOD;
445
446 target_complete_cmd(cmd, status);
447 kfree(ibr);
448}
449
450static void iblock_bio_destructor(struct bio *bio)
451{
452 struct se_cmd *cmd = bio->bi_private;
453 struct iblock_dev *ib_dev = cmd->se_dev->dev_ptr;
454
455 bio_free(bio, ib_dev->ibd_bio_set);
456}
457
458static struct bio *
459iblock_get_bio(struct se_cmd *cmd, sector_t lba, u32 sg_num)
460{
461 struct iblock_dev *ib_dev = cmd->se_dev->dev_ptr;
462 struct bio *bio;
463
464 /*
465 * Only allocate as many vector entries as the bio code allows us to,
466 * we'll loop later on until we have handled the whole request.
467 */
468 if (sg_num > BIO_MAX_PAGES)
469 sg_num = BIO_MAX_PAGES;
470
471 bio = bio_alloc_bioset(GFP_NOIO, sg_num, ib_dev->ibd_bio_set);
472 if (!bio) {
473 pr_err("Unable to allocate memory for bio\n");
474 return NULL;
475 }
476
477 bio->bi_bdev = ib_dev->ibd_bd;
478 bio->bi_private = cmd;
479 bio->bi_destructor = iblock_bio_destructor;
480 bio->bi_end_io = &iblock_bio_done;
481 bio->bi_sector = lba;
482 return bio;
483}
484
485static void iblock_submit_bios(struct bio_list *list, int rw)
486{
487 struct blk_plug plug;
488 struct bio *bio;
489
490 blk_start_plug(&plug);
491 while ((bio = bio_list_pop(list)))
492 submit_bio(rw, bio);
493 blk_finish_plug(&plug);
494}
495
496static int iblock_execute_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
497 u32 sgl_nents, enum dma_data_direction data_direction)
498{
499 struct se_device *dev = cmd->se_dev;
500 struct iblock_req *ibr;
501 struct bio *bio;
502 struct bio_list list;
503 struct scatterlist *sg;
504 u32 sg_num = sgl_nents;
505 sector_t block_lba;
506 unsigned bio_cnt;
507 int rw;
508 int i;
509
510 if (data_direction == DMA_TO_DEVICE) {
511 /*
512 * Force data to disk if we pretend to not have a volatile
513 * write cache, or the initiator set the Force Unit Access bit.
514 */
515 if (dev->se_sub_dev->se_dev_attrib.emulate_write_cache == 0 ||
516 (dev->se_sub_dev->se_dev_attrib.emulate_fua_write > 0 &&
517 (cmd->se_cmd_flags & SCF_FUA)))
518 rw = WRITE_FUA;
519 else
520 rw = WRITE;
521 } else {
522 rw = READ;
523 }
524
525 /*
526 * Convert the blocksize advertised to the initiator to the 512 byte
527 * units unconditionally used by the Linux block layer.
528 */
529 if (dev->se_sub_dev->se_dev_attrib.block_size == 4096)
530 block_lba = (cmd->t_task_lba << 3);
531 else if (dev->se_sub_dev->se_dev_attrib.block_size == 2048)
532 block_lba = (cmd->t_task_lba << 2);
533 else if (dev->se_sub_dev->se_dev_attrib.block_size == 1024)
534 block_lba = (cmd->t_task_lba << 1);
535 else if (dev->se_sub_dev->se_dev_attrib.block_size == 512)
536 block_lba = cmd->t_task_lba;
537 else {
538 pr_err("Unsupported SCSI -> BLOCK LBA conversion:"
539 " %u\n", dev->se_sub_dev->se_dev_attrib.block_size);
540 cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
541 return -ENOSYS;
542 }
543
544 ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
545 if (!ibr)
546 goto fail;
547 cmd->priv = ibr;
548
549 bio = iblock_get_bio(cmd, block_lba, sgl_nents);
550 if (!bio)
551 goto fail_free_ibr;
552
553 bio_list_init(&list);
554 bio_list_add(&list, bio);
555
556 atomic_set(&ibr->pending, 2);
557 bio_cnt = 1;
558
559 for_each_sg(sgl, sg, sgl_nents, i) {
560 /*
561 * XXX: if the length the device accepts is shorter than the
562 * length of the S/G list entry this will cause and
563 * endless loop. Better hope no driver uses huge pages.
564 */
565 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
566 != sg->length) {
567 if (bio_cnt >= IBLOCK_MAX_BIO_PER_TASK) {
568 iblock_submit_bios(&list, rw);
569 bio_cnt = 0;
570 }
571
572 bio = iblock_get_bio(cmd, block_lba, sg_num);
573 if (!bio)
574 goto fail_put_bios;
575
576 atomic_inc(&ibr->pending);
577 bio_list_add(&list, bio);
578 bio_cnt++;
579 }
580
581 /* Always in 512 byte units for Linux/Block */
582 block_lba += sg->length >> IBLOCK_LBA_SHIFT;
583 sg_num--;
584 }
585
586 iblock_submit_bios(&list, rw);
587 iblock_complete_cmd(cmd);
588 return 0;
589
590fail_put_bios:
591 while ((bio = bio_list_pop(&list)))
592 bio_put(bio);
593fail_free_ibr:
594 kfree(ibr);
595 cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
596fail:
597 return -ENOMEM;
598}
599
600static u32 iblock_get_device_rev(struct se_device *dev)
601{
602 return SCSI_SPC_2; /* Returns SPC-3 in Initiator Data */
603}
604
605static u32 iblock_get_device_type(struct se_device *dev)
606{
607 return TYPE_DISK;
608}
609
610static sector_t iblock_get_blocks(struct se_device *dev)
611{
612 struct iblock_dev *ibd = dev->dev_ptr;
613 struct block_device *bd = ibd->ibd_bd;
614 struct request_queue *q = bdev_get_queue(bd);
615
616 return iblock_emulate_read_cap_with_block_size(dev, bd, q);
617}
618
619static void iblock_bio_done(struct bio *bio, int err)
620{
621 struct se_cmd *cmd = bio->bi_private;
622 struct iblock_req *ibr = cmd->priv;
623
624 /*
625 * Set -EIO if !BIO_UPTODATE and the passed is still err=0
626 */
627 if (!test_bit(BIO_UPTODATE, &bio->bi_flags) && !err)
628 err = -EIO;
629
630 if (err != 0) {
631 pr_err("test_bit(BIO_UPTODATE) failed for bio: %p,"
632 " err: %d\n", bio, err);
633 /*
634 * Bump the ib_bio_err_cnt and release bio.
635 */
636 atomic_inc(&ibr->ib_bio_err_cnt);
637 smp_mb__after_atomic_inc();
638 }
639
640 bio_put(bio);
641
642 iblock_complete_cmd(cmd);
643}
644
645static struct se_subsystem_api iblock_template = {
646 .name = "iblock",
647 .owner = THIS_MODULE,
648 .transport_type = TRANSPORT_PLUGIN_VHBA_PDEV,
649 .write_cache_emulated = 1,
650 .fua_write_emulated = 1,
651 .attach_hba = iblock_attach_hba,
652 .detach_hba = iblock_detach_hba,
653 .allocate_virtdevice = iblock_allocate_virtdevice,
654 .create_virtdevice = iblock_create_virtdevice,
655 .free_device = iblock_free_device,
656 .execute_cmd = iblock_execute_cmd,
657 .do_discard = iblock_do_discard,
658 .do_sync_cache = iblock_emulate_sync_cache,
659 .check_configfs_dev_params = iblock_check_configfs_dev_params,
660 .set_configfs_dev_params = iblock_set_configfs_dev_params,
661 .show_configfs_dev_params = iblock_show_configfs_dev_params,
662 .get_device_rev = iblock_get_device_rev,
663 .get_device_type = iblock_get_device_type,
664 .get_blocks = iblock_get_blocks,
665};
666
667static int __init iblock_module_init(void)
668{
669 return transport_subsystem_register(&iblock_template);
670}
671
672static void iblock_module_exit(void)
673{
674 transport_subsystem_release(&iblock_template);
675}
676
677MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin");
678MODULE_AUTHOR("nab@Linux-iSCSI.org");
679MODULE_LICENSE("GPL");
680
681module_init(iblock_module_init);
682module_exit(iblock_module_exit);