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Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh...
[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/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
133 if (!(ib_dev)) {
134 printk(KERN_ERR "Unable to locate struct iblock_dev parameter\n");
135 return 0;
136 }
137 memset(&dev_limits, 0, sizeof(struct se_dev_limits));
138 /*
139 * These settings need to be made tunable..
140 */
141 ib_dev->ibd_bio_set = bioset_create(32, 64);
142 if (!(ib_dev->ibd_bio_set)) {
143 printk(KERN_ERR "IBLOCK: Unable to create bioset()\n");
144 return 0;
145 }
146 printk(KERN_INFO "IBLOCK: Created bio_set()\n");
147 /*
148 * iblock_check_configfs_dev_params() ensures that ib_dev->ibd_udev_path
149 * must already have been set in order for echo 1 > $HBA/$DEV/enable to run.
150 */
151 printk(KERN_INFO "IBLOCK: Claiming struct block_device: %s\n",
152 ib_dev->ibd_udev_path);
153
154 bd = blkdev_get_by_path(ib_dev->ibd_udev_path,
155 FMODE_WRITE|FMODE_READ|FMODE_EXCL, ib_dev);
156 if (IS_ERR(bd))
157 goto failed;
158 /*
159 * Setup the local scope queue_limits from struct request_queue->limits
160 * to pass into transport_add_device_to_core_hba() as struct se_dev_limits.
161 */
162 q = bdev_get_queue(bd);
163 limits = &dev_limits.limits;
164 limits->logical_block_size = bdev_logical_block_size(bd);
165 limits->max_hw_sectors = queue_max_hw_sectors(q);
166 limits->max_sectors = queue_max_sectors(q);
167 dev_limits.hw_queue_depth = IBLOCK_MAX_DEVICE_QUEUE_DEPTH;
168 dev_limits.queue_depth = IBLOCK_DEVICE_QUEUE_DEPTH;
169
170 ib_dev->ibd_major = MAJOR(bd->bd_dev);
171 ib_dev->ibd_minor = MINOR(bd->bd_dev);
172 ib_dev->ibd_bd = bd;
173
174 dev = transport_add_device_to_core_hba(hba,
175 &iblock_template, se_dev, dev_flags, (void *)ib_dev,
176 &dev_limits, "IBLOCK", IBLOCK_VERSION);
177 if (!(dev))
178 goto failed;
179
180 ib_dev->ibd_depth = dev->queue_depth;
181
182 /*
183 * Check if the underlying struct block_device request_queue supports
184 * the QUEUE_FLAG_DISCARD bit for UNMAP/WRITE_SAME in SCSI + TRIM
185 * in ATA and we need to set TPE=1
186 */
187 if (blk_queue_discard(bdev_get_queue(bd))) {
188 struct request_queue *q = bdev_get_queue(bd);
189
190 DEV_ATTRIB(dev)->max_unmap_lba_count =
191 q->limits.max_discard_sectors;
192 /*
193 * Currently hardcoded to 1 in Linux/SCSI code..
194 */
195 DEV_ATTRIB(dev)->max_unmap_block_desc_count = 1;
196 DEV_ATTRIB(dev)->unmap_granularity =
197 q->limits.discard_granularity;
198 DEV_ATTRIB(dev)->unmap_granularity_alignment =
199 q->limits.discard_alignment;
200
201 printk(KERN_INFO "IBLOCK: BLOCK Discard support available,"
202 " disabled by default\n");
203 }
204
205 return dev;
206
207 failed:
208 if (ib_dev->ibd_bio_set) {
209 bioset_free(ib_dev->ibd_bio_set);
210 ib_dev->ibd_bio_set = NULL;
211 }
212 ib_dev->ibd_bd = NULL;
213 ib_dev->ibd_major = 0;
214 ib_dev->ibd_minor = 0;
215 return NULL;
216 }
217
218 static void iblock_free_device(void *p)
219 {
220 struct iblock_dev *ib_dev = p;
221
222 if (ib_dev->ibd_bd != NULL)
223 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
224 if (ib_dev->ibd_bio_set != NULL)
225 bioset_free(ib_dev->ibd_bio_set);
226 kfree(ib_dev);
227 }
228
229 static inline struct iblock_req *IBLOCK_REQ(struct se_task *task)
230 {
231 return container_of(task, struct iblock_req, ib_task);
232 }
233
234 static struct se_task *
235 iblock_alloc_task(struct se_cmd *cmd)
236 {
237 struct iblock_req *ib_req;
238
239 ib_req = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
240 if (!(ib_req)) {
241 printk(KERN_ERR "Unable to allocate memory for struct iblock_req\n");
242 return NULL;
243 }
244
245 ib_req->ib_dev = SE_DEV(cmd)->dev_ptr;
246 atomic_set(&ib_req->ib_bio_cnt, 0);
247 return &ib_req->ib_task;
248 }
249
250 static unsigned long long iblock_emulate_read_cap_with_block_size(
251 struct se_device *dev,
252 struct block_device *bd,
253 struct request_queue *q)
254 {
255 unsigned long long blocks_long = (div_u64(i_size_read(bd->bd_inode),
256 bdev_logical_block_size(bd)) - 1);
257 u32 block_size = bdev_logical_block_size(bd);
258
259 if (block_size == DEV_ATTRIB(dev)->block_size)
260 return blocks_long;
261
262 switch (block_size) {
263 case 4096:
264 switch (DEV_ATTRIB(dev)->block_size) {
265 case 2048:
266 blocks_long <<= 1;
267 break;
268 case 1024:
269 blocks_long <<= 2;
270 break;
271 case 512:
272 blocks_long <<= 3;
273 default:
274 break;
275 }
276 break;
277 case 2048:
278 switch (DEV_ATTRIB(dev)->block_size) {
279 case 4096:
280 blocks_long >>= 1;
281 break;
282 case 1024:
283 blocks_long <<= 1;
284 break;
285 case 512:
286 blocks_long <<= 2;
287 break;
288 default:
289 break;
290 }
291 break;
292 case 1024:
293 switch (DEV_ATTRIB(dev)->block_size) {
294 case 4096:
295 blocks_long >>= 2;
296 break;
297 case 2048:
298 blocks_long >>= 1;
299 break;
300 case 512:
301 blocks_long <<= 1;
302 break;
303 default:
304 break;
305 }
306 break;
307 case 512:
308 switch (DEV_ATTRIB(dev)->block_size) {
309 case 4096:
310 blocks_long >>= 3;
311 break;
312 case 2048:
313 blocks_long >>= 2;
314 break;
315 case 1024:
316 blocks_long >>= 1;
317 break;
318 default:
319 break;
320 }
321 break;
322 default:
323 break;
324 }
325
326 return blocks_long;
327 }
328
329 /*
330 * Emulate SYCHRONIZE_CACHE_*
331 */
332 static void iblock_emulate_sync_cache(struct se_task *task)
333 {
334 struct se_cmd *cmd = TASK_CMD(task);
335 struct iblock_dev *ib_dev = cmd->se_dev->dev_ptr;
336 int immed = (T_TASK(cmd)->t_task_cdb[1] & 0x2);
337 sector_t error_sector;
338 int ret;
339
340 /*
341 * If the Immediate bit is set, queue up the GOOD response
342 * for this SYNCHRONIZE_CACHE op
343 */
344 if (immed)
345 transport_complete_sync_cache(cmd, 1);
346
347 /*
348 * blkdev_issue_flush() does not support a specifying a range, so
349 * we have to flush the entire cache.
350 */
351 ret = blkdev_issue_flush(ib_dev->ibd_bd, GFP_KERNEL, &error_sector);
352 if (ret != 0) {
353 printk(KERN_ERR "IBLOCK: block_issue_flush() failed: %d "
354 " error_sector: %llu\n", ret,
355 (unsigned long long)error_sector);
356 }
357
358 if (!immed)
359 transport_complete_sync_cache(cmd, ret == 0);
360 }
361
362 /*
363 * Tell TCM Core that we are capable of WriteCache emulation for
364 * an underlying struct se_device.
365 */
366 static int iblock_emulated_write_cache(struct se_device *dev)
367 {
368 return 1;
369 }
370
371 static int iblock_emulated_dpo(struct se_device *dev)
372 {
373 return 0;
374 }
375
376 /*
377 * Tell TCM Core that we will be emulating Forced Unit Access (FUA) for WRITEs
378 * for TYPE_DISK.
379 */
380 static int iblock_emulated_fua_write(struct se_device *dev)
381 {
382 return 1;
383 }
384
385 static int iblock_emulated_fua_read(struct se_device *dev)
386 {
387 return 0;
388 }
389
390 static int iblock_do_task(struct se_task *task)
391 {
392 struct se_device *dev = task->task_se_cmd->se_dev;
393 struct iblock_req *req = IBLOCK_REQ(task);
394 struct iblock_dev *ibd = (struct iblock_dev *)req->ib_dev;
395 struct request_queue *q = bdev_get_queue(ibd->ibd_bd);
396 struct bio *bio = req->ib_bio, *nbio = NULL;
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 while (bio) {
415 nbio = bio->bi_next;
416 bio->bi_next = NULL;
417 DEBUG_IBLOCK("Calling submit_bio() task: %p bio: %p"
418 " bio->bi_sector: %llu\n", task, bio, bio->bi_sector);
419
420 submit_bio(rw, bio);
421 bio = nbio;
422 }
423
424 if (q->unplug_fn)
425 q->unplug_fn(q);
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, *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
495 ret = snprintf(ib_dev->ibd_udev_path, SE_UDEV_PATH_LEN,
496 "%s", match_strdup(&args[0]));
497 printk(KERN_INFO "IBLOCK: Referencing UDEV path: %s\n",
498 ib_dev->ibd_udev_path);
499 ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH;
500 break;
501 case Opt_force:
502 match_int(args, &arg);
503 ib_dev->ibd_force = arg;
504 printk(KERN_INFO "IBLOCK: Set force=%d\n",
505 ib_dev->ibd_force);
506 break;
507 default:
508 break;
509 }
510 }
511
512 out:
513 kfree(orig);
514 return (!ret) ? count : ret;
515 }
516
517 static ssize_t iblock_check_configfs_dev_params(
518 struct se_hba *hba,
519 struct se_subsystem_dev *se_dev)
520 {
521 struct iblock_dev *ibd = se_dev->se_dev_su_ptr;
522
523 if (!(ibd->ibd_flags & IBDF_HAS_UDEV_PATH)) {
524 printk(KERN_ERR "Missing udev_path= parameters for IBLOCK\n");
525 return -1;
526 }
527
528 return 0;
529 }
530
531 static ssize_t iblock_show_configfs_dev_params(
532 struct se_hba *hba,
533 struct se_subsystem_dev *se_dev,
534 char *b)
535 {
536 struct iblock_dev *ibd = se_dev->se_dev_su_ptr;
537 struct block_device *bd = ibd->ibd_bd;
538 char buf[BDEVNAME_SIZE];
539 ssize_t bl = 0;
540
541 if (bd)
542 bl += sprintf(b + bl, "iBlock device: %s",
543 bdevname(bd, buf));
544 if (ibd->ibd_flags & IBDF_HAS_UDEV_PATH) {
545 bl += sprintf(b + bl, " UDEV PATH: %s\n",
546 ibd->ibd_udev_path);
547 } else
548 bl += sprintf(b + bl, "\n");
549
550 bl += sprintf(b + bl, " ");
551 if (bd) {
552 bl += sprintf(b + bl, "Major: %d Minor: %d %s\n",
553 ibd->ibd_major, ibd->ibd_minor, (!bd->bd_contains) ?
554 "" : (bd->bd_holder == (struct iblock_dev *)ibd) ?
555 "CLAIMED: IBLOCK" : "CLAIMED: OS");
556 } else {
557 bl += sprintf(b + bl, "Major: %d Minor: %d\n",
558 ibd->ibd_major, ibd->ibd_minor);
559 }
560
561 return bl;
562 }
563
564 static void iblock_bio_destructor(struct bio *bio)
565 {
566 struct se_task *task = bio->bi_private;
567 struct iblock_dev *ib_dev = task->se_dev->dev_ptr;
568
569 bio_free(bio, ib_dev->ibd_bio_set);
570 }
571
572 static struct bio *iblock_get_bio(
573 struct se_task *task,
574 struct iblock_req *ib_req,
575 struct iblock_dev *ib_dev,
576 int *ret,
577 sector_t lba,
578 u32 sg_num)
579 {
580 struct bio *bio;
581
582 bio = bio_alloc_bioset(GFP_NOIO, sg_num, ib_dev->ibd_bio_set);
583 if (!(bio)) {
584 printk(KERN_ERR "Unable to allocate memory for bio\n");
585 *ret = PYX_TRANSPORT_OUT_OF_MEMORY_RESOURCES;
586 return NULL;
587 }
588
589 DEBUG_IBLOCK("Allocated bio: %p task_sg_num: %u using ibd_bio_set:"
590 " %p\n", bio, task->task_sg_num, ib_dev->ibd_bio_set);
591 DEBUG_IBLOCK("Allocated bio: %p task_size: %u\n", bio, task->task_size);
592
593 bio->bi_bdev = ib_dev->ibd_bd;
594 bio->bi_private = (void *) task;
595 bio->bi_destructor = iblock_bio_destructor;
596 bio->bi_end_io = &iblock_bio_done;
597 bio->bi_sector = lba;
598 atomic_inc(&ib_req->ib_bio_cnt);
599
600 DEBUG_IBLOCK("Set bio->bi_sector: %llu\n", bio->bi_sector);
601 DEBUG_IBLOCK("Set ib_req->ib_bio_cnt: %d\n",
602 atomic_read(&ib_req->ib_bio_cnt));
603 return bio;
604 }
605
606 static int iblock_map_task_SG(struct se_task *task)
607 {
608 struct se_cmd *cmd = task->task_se_cmd;
609 struct se_device *dev = SE_DEV(cmd);
610 struct iblock_dev *ib_dev = task->se_dev->dev_ptr;
611 struct iblock_req *ib_req = IBLOCK_REQ(task);
612 struct bio *bio = NULL, *hbio = NULL, *tbio = NULL;
613 struct scatterlist *sg;
614 int ret = 0;
615 u32 i, sg_num = task->task_sg_num;
616 sector_t block_lba;
617 /*
618 * Do starting conversion up from non 512-byte blocksize with
619 * struct se_task SCSI blocksize into Linux/Block 512 units for BIO.
620 */
621 if (DEV_ATTRIB(dev)->block_size == 4096)
622 block_lba = (task->task_lba << 3);
623 else if (DEV_ATTRIB(dev)->block_size == 2048)
624 block_lba = (task->task_lba << 2);
625 else if (DEV_ATTRIB(dev)->block_size == 1024)
626 block_lba = (task->task_lba << 1);
627 else if (DEV_ATTRIB(dev)->block_size == 512)
628 block_lba = task->task_lba;
629 else {
630 printk(KERN_ERR "Unsupported SCSI -> BLOCK LBA conversion:"
631 " %u\n", DEV_ATTRIB(dev)->block_size);
632 return PYX_TRANSPORT_LU_COMM_FAILURE;
633 }
634
635 bio = iblock_get_bio(task, ib_req, ib_dev, &ret, block_lba, sg_num);
636 if (!(bio))
637 return ret;
638
639 ib_req->ib_bio = bio;
640 hbio = tbio = bio;
641 /*
642 * Use fs/bio.c:bio_add_pages() to setup the bio_vec maplist
643 * from TCM struct se_mem -> task->task_sg -> struct scatterlist memory.
644 */
645 for_each_sg(task->task_sg, sg, task->task_sg_num, i) {
646 DEBUG_IBLOCK("task: %p bio: %p Calling bio_add_page(): page:"
647 " %p len: %u offset: %u\n", task, bio, sg_page(sg),
648 sg->length, sg->offset);
649 again:
650 ret = bio_add_page(bio, sg_page(sg), sg->length, sg->offset);
651 if (ret != sg->length) {
652
653 DEBUG_IBLOCK("*** Set bio->bi_sector: %llu\n",
654 bio->bi_sector);
655 DEBUG_IBLOCK("** task->task_size: %u\n",
656 task->task_size);
657 DEBUG_IBLOCK("*** bio->bi_max_vecs: %u\n",
658 bio->bi_max_vecs);
659 DEBUG_IBLOCK("*** bio->bi_vcnt: %u\n",
660 bio->bi_vcnt);
661
662 bio = iblock_get_bio(task, ib_req, ib_dev, &ret,
663 block_lba, sg_num);
664 if (!(bio))
665 goto fail;
666
667 tbio = tbio->bi_next = bio;
668 DEBUG_IBLOCK("-----------------> Added +1 bio: %p to"
669 " list, Going to again\n", bio);
670 goto again;
671 }
672 /* Always in 512 byte units for Linux/Block */
673 block_lba += sg->length >> IBLOCK_LBA_SHIFT;
674 sg_num--;
675 DEBUG_IBLOCK("task: %p bio-add_page() passed!, decremented"
676 " sg_num to %u\n", task, sg_num);
677 DEBUG_IBLOCK("task: %p bio_add_page() passed!, increased lba"
678 " to %llu\n", task, block_lba);
679 DEBUG_IBLOCK("task: %p bio_add_page() passed!, bio->bi_vcnt:"
680 " %u\n", task, bio->bi_vcnt);
681 }
682
683 return 0;
684 fail:
685 while (hbio) {
686 bio = hbio;
687 hbio = hbio->bi_next;
688 bio->bi_next = NULL;
689 bio_put(bio);
690 }
691 return ret;
692 }
693
694 static unsigned char *iblock_get_cdb(struct se_task *task)
695 {
696 return IBLOCK_REQ(task)->ib_scsi_cdb;
697 }
698
699 static u32 iblock_get_device_rev(struct se_device *dev)
700 {
701 return SCSI_SPC_2; /* Returns SPC-3 in Initiator Data */
702 }
703
704 static u32 iblock_get_device_type(struct se_device *dev)
705 {
706 return TYPE_DISK;
707 }
708
709 static sector_t iblock_get_blocks(struct se_device *dev)
710 {
711 struct iblock_dev *ibd = dev->dev_ptr;
712 struct block_device *bd = ibd->ibd_bd;
713 struct request_queue *q = bdev_get_queue(bd);
714
715 return iblock_emulate_read_cap_with_block_size(dev, bd, q);
716 }
717
718 static void iblock_bio_done(struct bio *bio, int err)
719 {
720 struct se_task *task = bio->bi_private;
721 struct iblock_req *ibr = IBLOCK_REQ(task);
722 /*
723 * Set -EIO if !BIO_UPTODATE and the passed is still err=0
724 */
725 if (!(test_bit(BIO_UPTODATE, &bio->bi_flags)) && !(err))
726 err = -EIO;
727
728 if (err != 0) {
729 printk(KERN_ERR "test_bit(BIO_UPTODATE) failed for bio: %p,"
730 " err: %d\n", bio, err);
731 /*
732 * Bump the ib_bio_err_cnt and release bio.
733 */
734 atomic_inc(&ibr->ib_bio_err_cnt);
735 smp_mb__after_atomic_inc();
736 bio_put(bio);
737 /*
738 * Wait to complete the task until the last bio as completed.
739 */
740 if (!(atomic_dec_and_test(&ibr->ib_bio_cnt)))
741 return;
742
743 ibr->ib_bio = NULL;
744 transport_complete_task(task, 0);
745 return;
746 }
747 DEBUG_IBLOCK("done[%p] bio: %p task_lba: %llu bio_lba: %llu err=%d\n",
748 task, bio, task->task_lba, bio->bi_sector, err);
749 /*
750 * bio_put() will call iblock_bio_destructor() to release the bio back
751 * to ibr->ib_bio_set.
752 */
753 bio_put(bio);
754 /*
755 * Wait to complete the task until the last bio as completed.
756 */
757 if (!(atomic_dec_and_test(&ibr->ib_bio_cnt)))
758 return;
759 /*
760 * Return GOOD status for task if zero ib_bio_err_cnt exists.
761 */
762 ibr->ib_bio = NULL;
763 transport_complete_task(task, (!atomic_read(&ibr->ib_bio_err_cnt)));
764 }
765
766 static struct se_subsystem_api iblock_template = {
767 .name = "iblock",
768 .owner = THIS_MODULE,
769 .transport_type = TRANSPORT_PLUGIN_VHBA_PDEV,
770 .map_task_SG = iblock_map_task_SG,
771 .attach_hba = iblock_attach_hba,
772 .detach_hba = iblock_detach_hba,
773 .allocate_virtdevice = iblock_allocate_virtdevice,
774 .create_virtdevice = iblock_create_virtdevice,
775 .free_device = iblock_free_device,
776 .dpo_emulated = iblock_emulated_dpo,
777 .fua_write_emulated = iblock_emulated_fua_write,
778 .fua_read_emulated = iblock_emulated_fua_read,
779 .write_cache_emulated = iblock_emulated_write_cache,
780 .alloc_task = iblock_alloc_task,
781 .do_task = iblock_do_task,
782 .do_discard = iblock_do_discard,
783 .do_sync_cache = iblock_emulate_sync_cache,
784 .free_task = iblock_free_task,
785 .check_configfs_dev_params = iblock_check_configfs_dev_params,
786 .set_configfs_dev_params = iblock_set_configfs_dev_params,
787 .show_configfs_dev_params = iblock_show_configfs_dev_params,
788 .get_cdb = iblock_get_cdb,
789 .get_device_rev = iblock_get_device_rev,
790 .get_device_type = iblock_get_device_type,
791 .get_blocks = iblock_get_blocks,
792 };
793
794 static int __init iblock_module_init(void)
795 {
796 return transport_subsystem_register(&iblock_template);
797 }
798
799 static void iblock_module_exit(void)
800 {
801 transport_subsystem_release(&iblock_template);
802 }
803
804 MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin");
805 MODULE_AUTHOR("nab@Linux-iSCSI.org");
806 MODULE_LICENSE("GPL");
807
808 module_init(iblock_module_init);
809 module_exit(iblock_module_exit);
Linux kernel - Deliverables
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