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[zen-stable.git] / drivers / target / target_core_iblock.c
blob86639004af9eed7a7acf899d66157a05dd98ffc6
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 #if 0
51 #define DEBUG_IBLOCK(x...) printk(x)
52 #else
53 #define DEBUG_IBLOCK(x...)
54 #endif
55
56 static struct se_subsystem_api iblock_template;
57
58 static void iblock_bio_done(struct bio *, int);
59
60 /* iblock_attach_hba(): (Part of se_subsystem_api_t template)
61 *
62 *
63 */
64 static int iblock_attach_hba(struct se_hba *hba, u32 host_id)
65 {
66 struct iblock_hba *ib_host;
67
68 ib_host = kzalloc(sizeof(struct iblock_hba), GFP_KERNEL);
69 if (!(ib_host)) {
70 printk(KERN_ERR "Unable to allocate memory for"
71 " struct iblock_hba\n");
72 return -ENOMEM;
73 }
74
75 ib_host->iblock_host_id = host_id;
76
77 atomic_set(&hba->left_queue_depth, IBLOCK_HBA_QUEUE_DEPTH);
78 atomic_set(&hba->max_queue_depth, IBLOCK_HBA_QUEUE_DEPTH);
79 hba->hba_ptr = (void *) ib_host;
80
81 printk(KERN_INFO "CORE_HBA[%d] - TCM iBlock HBA Driver %s on"
82 " Generic Target Core Stack %s\n", hba->hba_id,
83 IBLOCK_VERSION, TARGET_CORE_MOD_VERSION);
84
85 printk(KERN_INFO "CORE_HBA[%d] - Attached iBlock HBA: %u to Generic"
86 " Target Core TCQ Depth: %d\n", hba->hba_id,
87 ib_host->iblock_host_id, atomic_read(&hba->max_queue_depth));
88
89 return 0;
90 }
91
92 static void iblock_detach_hba(struct se_hba *hba)
93 {
94 struct iblock_hba *ib_host = hba->hba_ptr;
95
96 printk(KERN_INFO "CORE_HBA[%d] - Detached iBlock HBA: %u from Generic"
97 " Target Core\n", hba->hba_id, ib_host->iblock_host_id);
98
99 kfree(ib_host);
100 hba->hba_ptr = NULL;
101 }
102
103 static void *iblock_allocate_virtdevice(struct se_hba *hba, const char *name)
104 {
105 struct iblock_dev *ib_dev = NULL;
106 struct iblock_hba *ib_host = hba->hba_ptr;
107
108 ib_dev = kzalloc(sizeof(struct iblock_dev), GFP_KERNEL);
109 if (!(ib_dev)) {
110 printk(KERN_ERR "Unable to allocate struct iblock_dev\n");
111 return NULL;
112 }
113 ib_dev->ibd_host = ib_host;
114
115 printk(KERN_INFO "IBLOCK: Allocated ib_dev for %s\n", name);
116
117 return ib_dev;
118 }
119
120 static struct se_device *iblock_create_virtdevice(
121 struct se_hba *hba,
122 struct se_subsystem_dev *se_dev,
123 void *p)
124 {
125 struct iblock_dev *ib_dev = p;
126 struct se_device *dev;
127 struct se_dev_limits dev_limits;
128 struct block_device *bd = NULL;
129 struct request_queue *q;
130 struct queue_limits *limits;
131 u32 dev_flags = 0;
132 int ret = -EINVAL;
133
134 if (!(ib_dev)) {
135 printk(KERN_ERR "Unable to locate struct iblock_dev parameter\n");
136 return ERR_PTR(ret);
137 }
138 memset(&dev_limits, 0, sizeof(struct se_dev_limits));
139 /*
140 * These settings need to be made tunable..
141 */
142 ib_dev->ibd_bio_set = bioset_create(32, 64);
143 if (!(ib_dev->ibd_bio_set)) {
144 printk(KERN_ERR "IBLOCK: Unable to create bioset()\n");
145 return ERR_PTR(-ENOMEM);
146 }
147 printk(KERN_INFO "IBLOCK: Created bio_set()\n");
148 /*
149 * iblock_check_configfs_dev_params() ensures that ib_dev->ibd_udev_path
150 * must already have been set in order for echo 1 > $HBA/$DEV/enable to run.
151 */
152 printk(KERN_INFO "IBLOCK: Claiming struct block_device: %s\n",
153 ib_dev->ibd_udev_path);
154
155 bd = blkdev_get_by_path(ib_dev->ibd_udev_path,
156 FMODE_WRITE|FMODE_READ|FMODE_EXCL, ib_dev);
157 if (IS_ERR(bd)) {
158 ret = PTR_ERR(bd);
159 goto failed;
160 }
161 /*
162 * Setup the local scope queue_limits from struct request_queue->limits
163 * to pass into transport_add_device_to_core_hba() as struct se_dev_limits.
164 */
165 q = bdev_get_queue(bd);
166 limits = &dev_limits.limits;
167 limits->logical_block_size = bdev_logical_block_size(bd);
168 limits->max_hw_sectors = queue_max_hw_sectors(q);
169 limits->max_sectors = queue_max_sectors(q);
170 dev_limits.hw_queue_depth = IBLOCK_MAX_DEVICE_QUEUE_DEPTH;
171 dev_limits.queue_depth = IBLOCK_DEVICE_QUEUE_DEPTH;
172
173 ib_dev->ibd_major = MAJOR(bd->bd_dev);
174 ib_dev->ibd_minor = MINOR(bd->bd_dev);
175 ib_dev->ibd_bd = bd;
176
177 dev = transport_add_device_to_core_hba(hba,
178 &iblock_template, se_dev, dev_flags, (void *)ib_dev,
179 &dev_limits, "IBLOCK", IBLOCK_VERSION);
180 if (!(dev))
181 goto failed;
182
183 ib_dev->ibd_depth = dev->queue_depth;
184
185 /*
186 * Check if the underlying struct block_device request_queue supports
187 * the QUEUE_FLAG_DISCARD bit for UNMAP/WRITE_SAME in SCSI + TRIM
188 * in ATA and we need to set TPE=1
189 */
190 if (blk_queue_discard(q)) {
191 DEV_ATTRIB(dev)->max_unmap_lba_count =
192 q->limits.max_discard_sectors;
193 /*
194 * Currently hardcoded to 1 in Linux/SCSI code..
195 */
196 DEV_ATTRIB(dev)->max_unmap_block_desc_count = 1;
197 DEV_ATTRIB(dev)->unmap_granularity =
198 q->limits.discard_granularity;
199 DEV_ATTRIB(dev)->unmap_granularity_alignment =
200 q->limits.discard_alignment;
201
202 printk(KERN_INFO "IBLOCK: BLOCK Discard support available,"
203 " disabled by default\n");
204 }
205
206 return dev;
207
208 failed:
209 if (ib_dev->ibd_bio_set) {
210 bioset_free(ib_dev->ibd_bio_set);
211 ib_dev->ibd_bio_set = NULL;
212 }
213 ib_dev->ibd_bd = NULL;
214 ib_dev->ibd_major = 0;
215 ib_dev->ibd_minor = 0;
216 return ERR_PTR(ret);
217 }
218
219 static void iblock_free_device(void *p)
220 {
221 struct iblock_dev *ib_dev = p;
222
223 if (ib_dev->ibd_bd != NULL)
224 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
225 if (ib_dev->ibd_bio_set != NULL)
226 bioset_free(ib_dev->ibd_bio_set);
227 kfree(ib_dev);
228 }
229
230 static inline struct iblock_req *IBLOCK_REQ(struct se_task *task)
231 {
232 return container_of(task, struct iblock_req, ib_task);
233 }
234
235 static struct se_task *
236 iblock_alloc_task(struct se_cmd *cmd)
237 {
238 struct iblock_req *ib_req;
239
240 ib_req = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
241 if (!(ib_req)) {
242 printk(KERN_ERR "Unable to allocate memory for struct iblock_req\n");
243 return NULL;
244 }
245
246 ib_req->ib_dev = SE_DEV(cmd)->dev_ptr;
247 atomic_set(&ib_req->ib_bio_cnt, 0);
248 return &ib_req->ib_task;
249 }
250
251 static unsigned long long iblock_emulate_read_cap_with_block_size(
252 struct se_device *dev,
253 struct block_device *bd,
254 struct request_queue *q)
255 {
256 unsigned long long blocks_long = (div_u64(i_size_read(bd->bd_inode),
257 bdev_logical_block_size(bd)) - 1);
258 u32 block_size = bdev_logical_block_size(bd);
259
260 if (block_size == DEV_ATTRIB(dev)->block_size)
261 return blocks_long;
262
263 switch (block_size) {
264 case 4096:
265 switch (DEV_ATTRIB(dev)->block_size) {
266 case 2048:
267 blocks_long <<= 1;
268 break;
269 case 1024:
270 blocks_long <<= 2;
271 break;
272 case 512:
273 blocks_long <<= 3;
274 default:
275 break;
276 }
277 break;
278 case 2048:
279 switch (DEV_ATTRIB(dev)->block_size) {
280 case 4096:
281 blocks_long >>= 1;
282 break;
283 case 1024:
284 blocks_long <<= 1;
285 break;
286 case 512:
287 blocks_long <<= 2;
288 break;
289 default:
290 break;
291 }
292 break;
293 case 1024:
294 switch (DEV_ATTRIB(dev)->block_size) {
295 case 4096:
296 blocks_long >>= 2;
297 break;
298 case 2048:
299 blocks_long >>= 1;
300 break;
301 case 512:
302 blocks_long <<= 1;
303 break;
304 default:
305 break;
306 }
307 break;
308 case 512:
309 switch (DEV_ATTRIB(dev)->block_size) {
310 case 4096:
311 blocks_long >>= 3;
312 break;
313 case 2048:
314 blocks_long >>= 2;
315 break;
316 case 1024:
317 blocks_long >>= 1;
318 break;
319 default:
320 break;
321 }
322 break;
323 default:
324 break;
325 }
326
327 return blocks_long;
328 }
329
330 /*
331 * Emulate SYCHRONIZE_CACHE_*
332 */
333 static void iblock_emulate_sync_cache(struct se_task *task)
334 {
335 struct se_cmd *cmd = TASK_CMD(task);
336 struct iblock_dev *ib_dev = cmd->se_dev->dev_ptr;
337 int immed = (T_TASK(cmd)->t_task_cdb[1] & 0x2);
338 sector_t error_sector;
339 int ret;
340
341 /*
342 * If the Immediate bit is set, queue up the GOOD response
343 * for this SYNCHRONIZE_CACHE op
344 */
345 if (immed)
346 transport_complete_sync_cache(cmd, 1);
347
348 /*
349 * blkdev_issue_flush() does not support a specifying a range, so
350 * we have to flush the entire cache.
351 */
352 ret = blkdev_issue_flush(ib_dev->ibd_bd, GFP_KERNEL, &error_sector);
353 if (ret != 0) {
354 printk(KERN_ERR "IBLOCK: block_issue_flush() failed: %d "
355 " error_sector: %llu\n", ret,
356 (unsigned long long)error_sector);
357 }
358
359 if (!immed)
360 transport_complete_sync_cache(cmd, ret == 0);
361 }
362
363 /*
364 * Tell TCM Core that we are capable of WriteCache emulation for
365 * an underlying struct se_device.
366 */
367 static int iblock_emulated_write_cache(struct se_device *dev)
368 {
369 return 1;
370 }
371
372 static int iblock_emulated_dpo(struct se_device *dev)
373 {
374 return 0;
375 }
376
377 /*
378 * Tell TCM Core that we will be emulating Forced Unit Access (FUA) for WRITEs
379 * for TYPE_DISK.
380 */
381 static int iblock_emulated_fua_write(struct se_device *dev)
382 {
383 return 1;
384 }
385
386 static int iblock_emulated_fua_read(struct se_device *dev)
387 {
388 return 0;
389 }
390
391 static int iblock_do_task(struct se_task *task)
392 {
393 struct se_device *dev = task->task_se_cmd->se_dev;
394 struct iblock_req *req = IBLOCK_REQ(task);
395 struct bio *bio = req->ib_bio, *nbio = NULL;
396 struct blk_plug plug;
397 int rw;
398
399 if (task->task_data_direction == DMA_TO_DEVICE) {
400 /*
401 * Force data to disk if we pretend to not have a volatile
402 * write cache, or the initiator set the Force Unit Access bit.
403 */
404 if (DEV_ATTRIB(dev)->emulate_write_cache == 0 ||
405 (DEV_ATTRIB(dev)->emulate_fua_write > 0 &&
406 T_TASK(task->task_se_cmd)->t_tasks_fua))
407 rw = WRITE_FUA;
408 else
409 rw = WRITE;
410 } else {
411 rw = READ;
412 }
413
414 blk_start_plug(&plug);
415 while (bio) {
416 nbio = bio->bi_next;
417 bio->bi_next = NULL;
418 DEBUG_IBLOCK("Calling submit_bio() task: %p bio: %p"
419 " bio->bi_sector: %llu\n", task, bio, bio->bi_sector);
420
421 submit_bio(rw, bio);
422 bio = nbio;
423 }
424 blk_finish_plug(&plug);
425
426 return PYX_TRANSPORT_SENT_TO_TRANSPORT;
427 }
428
429 static int iblock_do_discard(struct se_device *dev, sector_t lba, u32 range)
430 {
431 struct iblock_dev *ibd = dev->dev_ptr;
432 struct block_device *bd = ibd->ibd_bd;
433 int barrier = 0;
434
435 return blkdev_issue_discard(bd, lba, range, GFP_KERNEL, barrier);
436 }
437
438 static void iblock_free_task(struct se_task *task)
439 {
440 struct iblock_req *req = IBLOCK_REQ(task);
441 struct bio *bio, *hbio = req->ib_bio;
442 /*
443 * We only release the bio(s) here if iblock_bio_done() has not called
444 * bio_put() -> iblock_bio_destructor().
445 */
446 while (hbio != NULL) {
447 bio = hbio;
448 hbio = hbio->bi_next;
449 bio->bi_next = NULL;
450 bio_put(bio);
451 }
452
453 kfree(req);
454 }
455
456 enum {
457 Opt_udev_path, Opt_force, Opt_err
458 };
459
460 static match_table_t tokens = {
461 {Opt_udev_path, "udev_path=%s"},
462 {Opt_force, "force=%d"},
463 {Opt_err, NULL}
464 };
465
466 static ssize_t iblock_set_configfs_dev_params(struct se_hba *hba,
467 struct se_subsystem_dev *se_dev,
468 const char *page, ssize_t count)
469 {
470 struct iblock_dev *ib_dev = se_dev->se_dev_su_ptr;
471 char *orig, *ptr, *arg_p, *opts;
472 substring_t args[MAX_OPT_ARGS];
473 int ret = 0, arg, token;
474
475 opts = kstrdup(page, GFP_KERNEL);
476 if (!opts)
477 return -ENOMEM;
478
479 orig = opts;
480
481 while ((ptr = strsep(&opts, ",")) != NULL) {
482 if (!*ptr)
483 continue;
484
485 token = match_token(ptr, tokens, args);
486 switch (token) {
487 case Opt_udev_path:
488 if (ib_dev->ibd_bd) {
489 printk(KERN_ERR "Unable to set udev_path= while"
490 " ib_dev->ibd_bd exists\n");
491 ret = -EEXIST;
492 goto out;
493 }
494 arg_p = match_strdup(&args[0]);
495 if (!arg_p) {
496 ret = -ENOMEM;
497 break;
498 }
499 snprintf(ib_dev->ibd_udev_path, SE_UDEV_PATH_LEN,
500 "%s", arg_p);
501 kfree(arg_p);
502 printk(KERN_INFO "IBLOCK: Referencing UDEV path: %s\n",
503 ib_dev->ibd_udev_path);
504 ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH;
505 break;
506 case Opt_force:
507 match_int(args, &arg);
508 ib_dev->ibd_force = arg;
509 printk(KERN_INFO "IBLOCK: Set force=%d\n",
510 ib_dev->ibd_force);
511 break;
512 default:
513 break;
514 }
515 }
516
517 out:
518 kfree(orig);
519 return (!ret) ? count : ret;
520 }
521
522 static ssize_t iblock_check_configfs_dev_params(
523 struct se_hba *hba,
524 struct se_subsystem_dev *se_dev)
525 {
526 struct iblock_dev *ibd = se_dev->se_dev_su_ptr;
527
528 if (!(ibd->ibd_flags & IBDF_HAS_UDEV_PATH)) {
529 printk(KERN_ERR "Missing udev_path= parameters for IBLOCK\n");
530 return -1;
531 }
532
533 return 0;
534 }
535
536 static ssize_t iblock_show_configfs_dev_params(
537 struct se_hba *hba,
538 struct se_subsystem_dev *se_dev,
539 char *b)
540 {
541 struct iblock_dev *ibd = se_dev->se_dev_su_ptr;
542 struct block_device *bd = ibd->ibd_bd;
543 char buf[BDEVNAME_SIZE];
544 ssize_t bl = 0;
545
546 if (bd)
547 bl += sprintf(b + bl, "iBlock device: %s",
548 bdevname(bd, buf));
549 if (ibd->ibd_flags & IBDF_HAS_UDEV_PATH) {
550 bl += sprintf(b + bl, " UDEV PATH: %s\n",
551 ibd->ibd_udev_path);
552 } else
553 bl += sprintf(b + bl, "\n");
554
555 bl += sprintf(b + bl, " ");
556 if (bd) {
557 bl += sprintf(b + bl, "Major: %d Minor: %d %s\n",
558 ibd->ibd_major, ibd->ibd_minor, (!bd->bd_contains) ?
559 "" : (bd->bd_holder == (struct iblock_dev *)ibd) ?
560 "CLAIMED: IBLOCK" : "CLAIMED: OS");
561 } else {
562 bl += sprintf(b + bl, "Major: %d Minor: %d\n",
563 ibd->ibd_major, ibd->ibd_minor);
564 }
565
566 return bl;
567 }
568
569 static void iblock_bio_destructor(struct bio *bio)
570 {
571 struct se_task *task = bio->bi_private;
572 struct iblock_dev *ib_dev = task->se_dev->dev_ptr;
573
574 bio_free(bio, ib_dev->ibd_bio_set);
575 }
576
577 static struct bio *iblock_get_bio(
578 struct se_task *task,
579 struct iblock_req *ib_req,
580 struct iblock_dev *ib_dev,
581 int *ret,
582 sector_t lba,
583 u32 sg_num)
584 {
585 struct bio *bio;
586
587 bio = bio_alloc_bioset(GFP_NOIO, sg_num, ib_dev->ibd_bio_set);
588 if (!(bio)) {
589 printk(KERN_ERR "Unable to allocate memory for bio\n");
590 *ret = PYX_TRANSPORT_OUT_OF_MEMORY_RESOURCES;
591 return NULL;
592 }
593
594 DEBUG_IBLOCK("Allocated bio: %p task_sg_num: %u using ibd_bio_set:"
595 " %p\n", bio, task->task_sg_num, ib_dev->ibd_bio_set);
596 DEBUG_IBLOCK("Allocated bio: %p task_size: %u\n", bio, task->task_size);
597
598 bio->bi_bdev = ib_dev->ibd_bd;
599 bio->bi_private = (void *) task;
600 bio->bi_destructor = iblock_bio_destructor;
601 bio->bi_end_io = &iblock_bio_done;
602 bio->bi_sector = lba;
603 atomic_inc(&ib_req->ib_bio_cnt);
604
605 DEBUG_IBLOCK("Set bio->bi_sector: %llu\n", bio->bi_sector);
606 DEBUG_IBLOCK("Set ib_req->ib_bio_cnt: %d\n",
607 atomic_read(&ib_req->ib_bio_cnt));
608 return bio;
609 }
610
611 static int iblock_map_task_SG(struct se_task *task)
612 {
613 struct se_cmd *cmd = task->task_se_cmd;
614 struct se_device *dev = SE_DEV(cmd);
615 struct iblock_dev *ib_dev = task->se_dev->dev_ptr;
616 struct iblock_req *ib_req = IBLOCK_REQ(task);
617 struct bio *bio = NULL, *hbio = NULL, *tbio = NULL;
618 struct scatterlist *sg;
619 int ret = 0;
620 u32 i, sg_num = task->task_sg_num;
621 sector_t block_lba;
622 /*
623 * Do starting conversion up from non 512-byte blocksize with
624 * struct se_task SCSI blocksize into Linux/Block 512 units for BIO.
625 */
626 if (DEV_ATTRIB(dev)->block_size == 4096)
627 block_lba = (task->task_lba << 3);
628 else if (DEV_ATTRIB(dev)->block_size == 2048)
629 block_lba = (task->task_lba << 2);
630 else if (DEV_ATTRIB(dev)->block_size == 1024)
631 block_lba = (task->task_lba << 1);
632 else if (DEV_ATTRIB(dev)->block_size == 512)
633 block_lba = task->task_lba;
634 else {
635 printk(KERN_ERR "Unsupported SCSI -> BLOCK LBA conversion:"
636 " %u\n", DEV_ATTRIB(dev)->block_size);
637 return PYX_TRANSPORT_LU_COMM_FAILURE;
638 }
639
640 bio = iblock_get_bio(task, ib_req, ib_dev, &ret, block_lba, sg_num);
641 if (!(bio))
642 return ret;
643
644 ib_req->ib_bio = bio;
645 hbio = tbio = bio;
646 /*
647 * Use fs/bio.c:bio_add_pages() to setup the bio_vec maplist
648 * from TCM struct se_mem -> task->task_sg -> struct scatterlist memory.
649 */
650 for_each_sg(task->task_sg, sg, task->task_sg_num, i) {
651 DEBUG_IBLOCK("task: %p bio: %p Calling bio_add_page(): page:"
652 " %p len: %u offset: %u\n", task, bio, sg_page(sg),
653 sg->length, sg->offset);
654 again:
655 ret = bio_add_page(bio, sg_page(sg), sg->length, sg->offset);
656 if (ret != sg->length) {
657
658 DEBUG_IBLOCK("*** Set bio->bi_sector: %llu\n",
659 bio->bi_sector);
660 DEBUG_IBLOCK("** task->task_size: %u\n",
661 task->task_size);
662 DEBUG_IBLOCK("*** bio->bi_max_vecs: %u\n",
663 bio->bi_max_vecs);
664 DEBUG_IBLOCK("*** bio->bi_vcnt: %u\n",
665 bio->bi_vcnt);
666
667 bio = iblock_get_bio(task, ib_req, ib_dev, &ret,
668 block_lba, sg_num);
669 if (!(bio))
670 goto fail;
671
672 tbio = tbio->bi_next = bio;
673 DEBUG_IBLOCK("-----------------> Added +1 bio: %p to"
674 " list, Going to again\n", bio);
675 goto again;
676 }
677 /* Always in 512 byte units for Linux/Block */
678 block_lba += sg->length >> IBLOCK_LBA_SHIFT;
679 sg_num--;
680 DEBUG_IBLOCK("task: %p bio-add_page() passed!, decremented"
681 " sg_num to %u\n", task, sg_num);
682 DEBUG_IBLOCK("task: %p bio_add_page() passed!, increased lba"
683 " to %llu\n", task, block_lba);
684 DEBUG_IBLOCK("task: %p bio_add_page() passed!, bio->bi_vcnt:"
685 " %u\n", task, bio->bi_vcnt);
686 }
687
688 return 0;
689 fail:
690 while (hbio) {
691 bio = hbio;
692 hbio = hbio->bi_next;
693 bio->bi_next = NULL;
694 bio_put(bio);
695 }
696 return ret;
697 }
698
699 static unsigned char *iblock_get_cdb(struct se_task *task)
700 {
701 return IBLOCK_REQ(task)->ib_scsi_cdb;
702 }
703
704 static u32 iblock_get_device_rev(struct se_device *dev)
705 {
706 return SCSI_SPC_2; /* Returns SPC-3 in Initiator Data */
707 }
708
709 static u32 iblock_get_device_type(struct se_device *dev)
710 {
711 return TYPE_DISK;
712 }
713
714 static sector_t iblock_get_blocks(struct se_device *dev)
715 {
716 struct iblock_dev *ibd = dev->dev_ptr;
717 struct block_device *bd = ibd->ibd_bd;
718 struct request_queue *q = bdev_get_queue(bd);
719
720 return iblock_emulate_read_cap_with_block_size(dev, bd, q);
721 }
722
723 static void iblock_bio_done(struct bio *bio, int err)
724 {
725 struct se_task *task = bio->bi_private;
726 struct iblock_req *ibr = IBLOCK_REQ(task);
727 /*
728 * Set -EIO if !BIO_UPTODATE and the passed is still err=0
729 */
730 if (!(test_bit(BIO_UPTODATE, &bio->bi_flags)) && !(err))
731 err = -EIO;
732
733 if (err != 0) {
734 printk(KERN_ERR "test_bit(BIO_UPTODATE) failed for bio: %p,"
735 " err: %d\n", bio, err);
736 /*
737 * Bump the ib_bio_err_cnt and release bio.
738 */
739 atomic_inc(&ibr->ib_bio_err_cnt);
740 smp_mb__after_atomic_inc();
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 ibr->ib_bio = NULL;
749 transport_complete_task(task, 0);
750 return;
751 }
752 DEBUG_IBLOCK("done[%p] bio: %p task_lba: %llu bio_lba: %llu err=%d\n",
753 task, bio, task->task_lba, bio->bi_sector, err);
754 /*
755 * bio_put() will call iblock_bio_destructor() to release the bio back
756 * to ibr->ib_bio_set.
757 */
758 bio_put(bio);
759 /*
760 * Wait to complete the task until the last bio as completed.
761 */
762 if (!(atomic_dec_and_test(&ibr->ib_bio_cnt)))
763 return;
764 /*
765 * Return GOOD status for task if zero ib_bio_err_cnt exists.
766 */
767 ibr->ib_bio = NULL;
768 transport_complete_task(task, (!atomic_read(&ibr->ib_bio_err_cnt)));
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 .map_task_SG = iblock_map_task_SG,
776 .attach_hba = iblock_attach_hba,
777 .detach_hba = iblock_detach_hba,
778 .allocate_virtdevice = iblock_allocate_virtdevice,
779 .create_virtdevice = iblock_create_virtdevice,
780 .free_device = iblock_free_device,
781 .dpo_emulated = iblock_emulated_dpo,
782 .fua_write_emulated = iblock_emulated_fua_write,
783 .fua_read_emulated = iblock_emulated_fua_read,
784 .write_cache_emulated = iblock_emulated_write_cache,
785 .alloc_task = iblock_alloc_task,
786 .do_task = iblock_do_task,
787 .do_discard = iblock_do_discard,
788 .do_sync_cache = iblock_emulate_sync_cache,
789 .free_task = iblock_free_task,
790 .check_configfs_dev_params = iblock_check_configfs_dev_params,
791 .set_configfs_dev_params = iblock_set_configfs_dev_params,
792 .show_configfs_dev_params = iblock_show_configfs_dev_params,
793 .get_cdb = iblock_get_cdb,
794 .get_device_rev = iblock_get_device_rev,
795 .get_device_type = iblock_get_device_type,
796 .get_blocks = iblock_get_blocks,
797 };
798
799 static int __init iblock_module_init(void)
800 {
801 return transport_subsystem_register(&iblock_template);
802 }
803
804 static void iblock_module_exit(void)
805 {
806 transport_subsystem_release(&iblock_template);
807 }
808
809 MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin");
810 MODULE_AUTHOR("nab@Linux-iSCSI.org");
811 MODULE_LICENSE("GPL");
812
813 module_init(iblock_module_init);
814 module_exit(iblock_module_exit);