target: Fix transport_cmd_finish_abort queue removal bug
[linux-2.6.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 static struct se_subsystem_api iblock_template;
51
52 static void iblock_bio_done(struct bio *, int);
53
54 /*      iblock_attach_hba(): (Part of se_subsystem_api_t template)
55  *
56  *
57  */
58 static int iblock_attach_hba(struct se_hba *hba, u32 host_id)
59 {
60         struct iblock_hba *ib_host;
61
62         ib_host = kzalloc(sizeof(struct iblock_hba), GFP_KERNEL);
63         if (!ib_host) {
64                 pr_err("Unable to allocate memory for"
65                                 " struct iblock_hba\n");
66                 return -ENOMEM;
67         }
68
69         ib_host->iblock_host_id = host_id;
70
71         hba->hba_ptr = ib_host;
72
73         pr_debug("CORE_HBA[%d] - TCM iBlock HBA Driver %s on"
74                 " Generic Target Core Stack %s\n", hba->hba_id,
75                 IBLOCK_VERSION, TARGET_CORE_MOD_VERSION);
76
77         pr_debug("CORE_HBA[%d] - Attached iBlock HBA: %u to Generic\n",
78                 hba->hba_id, ib_host->iblock_host_id);
79
80         return 0;
81 }
82
83 static void iblock_detach_hba(struct se_hba *hba)
84 {
85         struct iblock_hba *ib_host = hba->hba_ptr;
86
87         pr_debug("CORE_HBA[%d] - Detached iBlock HBA: %u from Generic"
88                 " Target Core\n", hba->hba_id, ib_host->iblock_host_id);
89
90         kfree(ib_host);
91         hba->hba_ptr = NULL;
92 }
93
94 static void *iblock_allocate_virtdevice(struct se_hba *hba, const char *name)
95 {
96         struct iblock_dev *ib_dev = NULL;
97         struct iblock_hba *ib_host = hba->hba_ptr;
98
99         ib_dev = kzalloc(sizeof(struct iblock_dev), GFP_KERNEL);
100         if (!ib_dev) {
101                 pr_err("Unable to allocate struct iblock_dev\n");
102                 return NULL;
103         }
104         ib_dev->ibd_host = ib_host;
105
106         pr_debug( "IBLOCK: Allocated ib_dev for %s\n", name);
107
108         return ib_dev;
109 }
110
111 static struct se_device *iblock_create_virtdevice(
112         struct se_hba *hba,
113         struct se_subsystem_dev *se_dev,
114         void *p)
115 {
116         struct iblock_dev *ib_dev = p;
117         struct se_device *dev;
118         struct se_dev_limits dev_limits;
119         struct block_device *bd = NULL;
120         struct request_queue *q;
121         struct queue_limits *limits;
122         u32 dev_flags = 0;
123         int ret = -EINVAL;
124
125         if (!ib_dev) {
126                 pr_err("Unable to locate struct iblock_dev parameter\n");
127                 return ERR_PTR(ret);
128         }
129         memset(&dev_limits, 0, sizeof(struct se_dev_limits));
130         /*
131          * These settings need to be made tunable..
132          */
133         ib_dev->ibd_bio_set = bioset_create(32, 64);
134         if (!ib_dev->ibd_bio_set) {
135                 pr_err("IBLOCK: Unable to create bioset()\n");
136                 return ERR_PTR(-ENOMEM);
137         }
138         pr_debug("IBLOCK: Created bio_set()\n");
139         /*
140          * iblock_check_configfs_dev_params() ensures that ib_dev->ibd_udev_path
141          * must already have been set in order for echo 1 > $HBA/$DEV/enable to run.
142          */
143         pr_debug( "IBLOCK: Claiming struct block_device: %s\n",
144                         ib_dev->ibd_udev_path);
145
146         bd = blkdev_get_by_path(ib_dev->ibd_udev_path,
147                                 FMODE_WRITE|FMODE_READ|FMODE_EXCL, ib_dev);
148         if (IS_ERR(bd)) {
149                 ret = PTR_ERR(bd);
150                 goto failed;
151         }
152         /*
153          * Setup the local scope queue_limits from struct request_queue->limits
154          * to pass into transport_add_device_to_core_hba() as struct se_dev_limits.
155          */
156         q = bdev_get_queue(bd);
157         limits = &dev_limits.limits;
158         limits->logical_block_size = bdev_logical_block_size(bd);
159         limits->max_hw_sectors = queue_max_hw_sectors(q);
160         limits->max_sectors = queue_max_sectors(q);
161         dev_limits.hw_queue_depth = q->nr_requests;
162         dev_limits.queue_depth = q->nr_requests;
163
164         ib_dev->ibd_bd = bd;
165
166         dev = transport_add_device_to_core_hba(hba,
167                         &iblock_template, se_dev, dev_flags, ib_dev,
168                         &dev_limits, "IBLOCK", IBLOCK_VERSION);
169         if (!dev)
170                 goto failed;
171
172         /*
173          * Check if the underlying struct block_device request_queue supports
174          * the QUEUE_FLAG_DISCARD bit for UNMAP/WRITE_SAME in SCSI + TRIM
175          * in ATA and we need to set TPE=1
176          */
177         if (blk_queue_discard(q)) {
178                 dev->se_sub_dev->se_dev_attrib.max_unmap_lba_count =
179                                 q->limits.max_discard_sectors;
180                 /*
181                  * Currently hardcoded to 1 in Linux/SCSI code..
182                  */
183                 dev->se_sub_dev->se_dev_attrib.max_unmap_block_desc_count = 1;
184                 dev->se_sub_dev->se_dev_attrib.unmap_granularity =
185                                 q->limits.discard_granularity;
186                 dev->se_sub_dev->se_dev_attrib.unmap_granularity_alignment =
187                                 q->limits.discard_alignment;
188
189                 pr_debug("IBLOCK: BLOCK Discard support available,"
190                                 " disabled by default\n");
191         }
192
193         if (blk_queue_nonrot(q))
194                 dev->se_sub_dev->se_dev_attrib.is_nonrot = 1;
195
196         return dev;
197
198 failed:
199         if (ib_dev->ibd_bio_set) {
200                 bioset_free(ib_dev->ibd_bio_set);
201                 ib_dev->ibd_bio_set = NULL;
202         }
203         ib_dev->ibd_bd = NULL;
204         return ERR_PTR(ret);
205 }
206
207 static void iblock_free_device(void *p)
208 {
209         struct iblock_dev *ib_dev = p;
210
211         if (ib_dev->ibd_bd != NULL)
212                 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
213         if (ib_dev->ibd_bio_set != NULL)
214                 bioset_free(ib_dev->ibd_bio_set);
215         kfree(ib_dev);
216 }
217
218 static inline struct iblock_req *IBLOCK_REQ(struct se_task *task)
219 {
220         return container_of(task, struct iblock_req, ib_task);
221 }
222
223 static struct se_task *
224 iblock_alloc_task(unsigned char *cdb)
225 {
226         struct iblock_req *ib_req;
227
228         ib_req = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
229         if (!ib_req) {
230                 pr_err("Unable to allocate memory for struct iblock_req\n");
231                 return NULL;
232         }
233
234         atomic_set(&ib_req->ib_bio_cnt, 0);
235         return &ib_req->ib_task;
236 }
237
238 static unsigned long long iblock_emulate_read_cap_with_block_size(
239         struct se_device *dev,
240         struct block_device *bd,
241         struct request_queue *q)
242 {
243         unsigned long long blocks_long = (div_u64(i_size_read(bd->bd_inode),
244                                         bdev_logical_block_size(bd)) - 1);
245         u32 block_size = bdev_logical_block_size(bd);
246
247         if (block_size == dev->se_sub_dev->se_dev_attrib.block_size)
248                 return blocks_long;
249
250         switch (block_size) {
251         case 4096:
252                 switch (dev->se_sub_dev->se_dev_attrib.block_size) {
253                 case 2048:
254                         blocks_long <<= 1;
255                         break;
256                 case 1024:
257                         blocks_long <<= 2;
258                         break;
259                 case 512:
260                         blocks_long <<= 3;
261                 default:
262                         break;
263                 }
264                 break;
265         case 2048:
266                 switch (dev->se_sub_dev->se_dev_attrib.block_size) {
267                 case 4096:
268                         blocks_long >>= 1;
269                         break;
270                 case 1024:
271                         blocks_long <<= 1;
272                         break;
273                 case 512:
274                         blocks_long <<= 2;
275                         break;
276                 default:
277                         break;
278                 }
279                 break;
280         case 1024:
281                 switch (dev->se_sub_dev->se_dev_attrib.block_size) {
282                 case 4096:
283                         blocks_long >>= 2;
284                         break;
285                 case 2048:
286                         blocks_long >>= 1;
287                         break;
288                 case 512:
289                         blocks_long <<= 1;
290                         break;
291                 default:
292                         break;
293                 }
294                 break;
295         case 512:
296                 switch (dev->se_sub_dev->se_dev_attrib.block_size) {
297                 case 4096:
298                         blocks_long >>= 3;
299                         break;
300                 case 2048:
301                         blocks_long >>= 2;
302                         break;
303                 case 1024:
304                         blocks_long >>= 1;
305                         break;
306                 default:
307                         break;
308                 }
309                 break;
310         default:
311                 break;
312         }
313
314         return blocks_long;
315 }
316
317 /*
318  * Emulate SYCHRONIZE_CACHE_*
319  */
320 static void iblock_emulate_sync_cache(struct se_task *task)
321 {
322         struct se_cmd *cmd = task->task_se_cmd;
323         struct iblock_dev *ib_dev = cmd->se_dev->dev_ptr;
324         int immed = (cmd->t_task_cdb[1] & 0x2);
325         sector_t error_sector;
326         int ret;
327
328         /*
329          * If the Immediate bit is set, queue up the GOOD response
330          * for this SYNCHRONIZE_CACHE op
331          */
332         if (immed)
333                 transport_complete_sync_cache(cmd, 1);
334
335         /*
336          * blkdev_issue_flush() does not support a specifying a range, so
337          * we have to flush the entire cache.
338          */
339         ret = blkdev_issue_flush(ib_dev->ibd_bd, GFP_KERNEL, &error_sector);
340         if (ret != 0) {
341                 pr_err("IBLOCK: block_issue_flush() failed: %d "
342                         " error_sector: %llu\n", ret,
343                         (unsigned long long)error_sector);
344         }
345
346         if (!immed)
347                 transport_complete_sync_cache(cmd, ret == 0);
348 }
349
350 /*
351  * Tell TCM Core that we are capable of WriteCache emulation for
352  * an underlying struct se_device.
353  */
354 static int iblock_emulated_write_cache(struct se_device *dev)
355 {
356         return 1;
357 }
358
359 static int iblock_emulated_dpo(struct se_device *dev)
360 {
361         return 0;
362 }
363
364 /*
365  * Tell TCM Core that we will be emulating Forced Unit Access (FUA) for WRITEs
366  * for TYPE_DISK.
367  */
368 static int iblock_emulated_fua_write(struct se_device *dev)
369 {
370         return 1;
371 }
372
373 static int iblock_emulated_fua_read(struct se_device *dev)
374 {
375         return 0;
376 }
377
378 static int iblock_do_task(struct se_task *task)
379 {
380         struct se_device *dev = task->task_se_cmd->se_dev;
381         struct iblock_req *req = IBLOCK_REQ(task);
382         struct bio *bio = req->ib_bio, *nbio = NULL;
383         struct blk_plug plug;
384         int rw;
385
386         if (task->task_data_direction == DMA_TO_DEVICE) {
387                 /*
388                  * Force data to disk if we pretend to not have a volatile
389                  * write cache, or the initiator set the Force Unit Access bit.
390                  */
391                 if (dev->se_sub_dev->se_dev_attrib.emulate_write_cache == 0 ||
392                     (dev->se_sub_dev->se_dev_attrib.emulate_fua_write > 0 &&
393                      task->task_se_cmd->t_tasks_fua))
394                         rw = WRITE_FUA;
395                 else
396                         rw = WRITE;
397         } else {
398                 rw = READ;
399         }
400
401         blk_start_plug(&plug);
402         while (bio) {
403                 nbio = bio->bi_next;
404                 bio->bi_next = NULL;
405                 pr_debug("Calling submit_bio() task: %p bio: %p"
406                         " bio->bi_sector: %llu\n", task, bio,
407                          (unsigned long long)bio->bi_sector);
408
409                 submit_bio(rw, bio);
410                 bio = nbio;
411         }
412         blk_finish_plug(&plug);
413
414         return PYX_TRANSPORT_SENT_TO_TRANSPORT;
415 }
416
417 static int iblock_do_discard(struct se_device *dev, sector_t lba, u32 range)
418 {
419         struct iblock_dev *ibd = dev->dev_ptr;
420         struct block_device *bd = ibd->ibd_bd;
421         int barrier = 0;
422
423         return blkdev_issue_discard(bd, lba, range, GFP_KERNEL, barrier);
424 }
425
426 static void iblock_free_task(struct se_task *task)
427 {
428         struct iblock_req *req = IBLOCK_REQ(task);
429         struct bio *bio, *hbio = req->ib_bio;
430         /*
431          * We only release the bio(s) here if iblock_bio_done() has not called
432          * bio_put() -> iblock_bio_destructor().
433          */
434         while (hbio != NULL) {
435                 bio = hbio;
436                 hbio = hbio->bi_next;
437                 bio->bi_next = NULL;
438                 bio_put(bio);
439         }
440
441         kfree(req);
442 }
443
444 enum {
445         Opt_udev_path, Opt_force, Opt_err
446 };
447
448 static match_table_t tokens = {
449         {Opt_udev_path, "udev_path=%s"},
450         {Opt_force, "force=%d"},
451         {Opt_err, NULL}
452 };
453
454 static ssize_t iblock_set_configfs_dev_params(struct se_hba *hba,
455                                                struct se_subsystem_dev *se_dev,
456                                                const char *page, ssize_t count)
457 {
458         struct iblock_dev *ib_dev = se_dev->se_dev_su_ptr;
459         char *orig, *ptr, *arg_p, *opts;
460         substring_t args[MAX_OPT_ARGS];
461         int ret = 0, token;
462
463         opts = kstrdup(page, GFP_KERNEL);
464         if (!opts)
465                 return -ENOMEM;
466
467         orig = opts;
468
469         while ((ptr = strsep(&opts, ",")) != NULL) {
470                 if (!*ptr)
471                         continue;
472
473                 token = match_token(ptr, tokens, args);
474                 switch (token) {
475                 case Opt_udev_path:
476                         if (ib_dev->ibd_bd) {
477                                 pr_err("Unable to set udev_path= while"
478                                         " ib_dev->ibd_bd exists\n");
479                                 ret = -EEXIST;
480                                 goto out;
481                         }
482                         arg_p = match_strdup(&args[0]);
483                         if (!arg_p) {
484                                 ret = -ENOMEM;
485                                 break;
486                         }
487                         snprintf(ib_dev->ibd_udev_path, SE_UDEV_PATH_LEN,
488                                         "%s", arg_p);
489                         kfree(arg_p);
490                         pr_debug("IBLOCK: Referencing UDEV path: %s\n",
491                                         ib_dev->ibd_udev_path);
492                         ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH;
493                         break;
494                 case Opt_force:
495                         break;
496                 default:
497                         break;
498                 }
499         }
500
501 out:
502         kfree(orig);
503         return (!ret) ? count : ret;
504 }
505
506 static ssize_t iblock_check_configfs_dev_params(
507         struct se_hba *hba,
508         struct se_subsystem_dev *se_dev)
509 {
510         struct iblock_dev *ibd = se_dev->se_dev_su_ptr;
511
512         if (!(ibd->ibd_flags & IBDF_HAS_UDEV_PATH)) {
513                 pr_err("Missing udev_path= parameters for IBLOCK\n");
514                 return -EINVAL;
515         }
516
517         return 0;
518 }
519
520 static ssize_t iblock_show_configfs_dev_params(
521         struct se_hba *hba,
522         struct se_subsystem_dev *se_dev,
523         char *b)
524 {
525         struct iblock_dev *ibd = se_dev->se_dev_su_ptr;
526         struct block_device *bd = ibd->ibd_bd;
527         char buf[BDEVNAME_SIZE];
528         ssize_t bl = 0;
529
530         if (bd)
531                 bl += sprintf(b + bl, "iBlock device: %s",
532                                 bdevname(bd, buf));
533         if (ibd->ibd_flags & IBDF_HAS_UDEV_PATH) {
534                 bl += sprintf(b + bl, "  UDEV PATH: %s\n",
535                                 ibd->ibd_udev_path);
536         } else
537                 bl += sprintf(b + bl, "\n");
538
539         bl += sprintf(b + bl, "        ");
540         if (bd) {
541                 bl += sprintf(b + bl, "Major: %d Minor: %d  %s\n",
542                         MAJOR(bd->bd_dev), MINOR(bd->bd_dev), (!bd->bd_contains) ?
543                         "" : (bd->bd_holder == (struct iblock_dev *)ibd) ?
544                         "CLAIMED: IBLOCK" : "CLAIMED: OS");
545         } else {
546                 bl += sprintf(b + bl, "Major: 0 Minor: 0\n");
547         }
548
549         return bl;
550 }
551
552 static void iblock_bio_destructor(struct bio *bio)
553 {
554         struct se_task *task = bio->bi_private;
555         struct iblock_dev *ib_dev = task->se_dev->dev_ptr;
556
557         bio_free(bio, ib_dev->ibd_bio_set);
558 }
559
560 static struct bio *iblock_get_bio(
561         struct se_task *task,
562         struct iblock_req *ib_req,
563         struct iblock_dev *ib_dev,
564         int *ret,
565         sector_t lba,
566         u32 sg_num)
567 {
568         struct bio *bio;
569
570         bio = bio_alloc_bioset(GFP_NOIO, sg_num, ib_dev->ibd_bio_set);
571         if (!bio) {
572                 pr_err("Unable to allocate memory for bio\n");
573                 *ret = PYX_TRANSPORT_OUT_OF_MEMORY_RESOURCES;
574                 return NULL;
575         }
576
577         pr_debug("Allocated bio: %p task_sg_nents: %u using ibd_bio_set:"
578                 " %p\n", bio, task->task_sg_nents, ib_dev->ibd_bio_set);
579         pr_debug("Allocated bio: %p task_size: %u\n", bio, task->task_size);
580
581         bio->bi_bdev = ib_dev->ibd_bd;
582         bio->bi_private = task;
583         bio->bi_destructor = iblock_bio_destructor;
584         bio->bi_end_io = &iblock_bio_done;
585         bio->bi_sector = lba;
586         atomic_inc(&ib_req->ib_bio_cnt);
587
588         pr_debug("Set bio->bi_sector: %llu\n", (unsigned long long)bio->bi_sector);
589         pr_debug("Set ib_req->ib_bio_cnt: %d\n",
590                         atomic_read(&ib_req->ib_bio_cnt));
591         return bio;
592 }
593
594 static int iblock_map_data_SG(struct se_task *task)
595 {
596         struct se_cmd *cmd = task->task_se_cmd;
597         struct se_device *dev = cmd->se_dev;
598         struct iblock_dev *ib_dev = task->se_dev->dev_ptr;
599         struct iblock_req *ib_req = IBLOCK_REQ(task);
600         struct bio *bio = NULL, *hbio = NULL, *tbio = NULL;
601         struct scatterlist *sg;
602         int ret = 0;
603         u32 i, sg_num = task->task_sg_nents;
604         sector_t block_lba;
605         /*
606          * Do starting conversion up from non 512-byte blocksize with
607          * struct se_task SCSI blocksize into Linux/Block 512 units for BIO.
608          */
609         if (dev->se_sub_dev->se_dev_attrib.block_size == 4096)
610                 block_lba = (task->task_lba << 3);
611         else if (dev->se_sub_dev->se_dev_attrib.block_size == 2048)
612                 block_lba = (task->task_lba << 2);
613         else if (dev->se_sub_dev->se_dev_attrib.block_size == 1024)
614                 block_lba = (task->task_lba << 1);
615         else if (dev->se_sub_dev->se_dev_attrib.block_size == 512)
616                 block_lba = task->task_lba;
617         else {
618                 pr_err("Unsupported SCSI -> BLOCK LBA conversion:"
619                                 " %u\n", dev->se_sub_dev->se_dev_attrib.block_size);
620                 return PYX_TRANSPORT_LU_COMM_FAILURE;
621         }
622
623         bio = iblock_get_bio(task, ib_req, ib_dev, &ret, block_lba, sg_num);
624         if (!bio)
625                 return ret;
626
627         ib_req->ib_bio = bio;
628         hbio = tbio = bio;
629         /*
630          * Use fs/bio.c:bio_add_pages() to setup the bio_vec maplist
631          * from task->task_sg -> struct scatterlist memory.
632          */
633         for_each_sg(task->task_sg, sg, task->task_sg_nents, i) {
634                 pr_debug("task: %p bio: %p Calling bio_add_page(): page:"
635                         " %p len: %u offset: %u\n", task, bio, sg_page(sg),
636                                 sg->length, sg->offset);
637 again:
638                 ret = bio_add_page(bio, sg_page(sg), sg->length, sg->offset);
639                 if (ret != sg->length) {
640
641                         pr_debug("*** Set bio->bi_sector: %llu\n",
642                                  (unsigned long long)bio->bi_sector);
643                         pr_debug("** task->task_size: %u\n",
644                                         task->task_size);
645                         pr_debug("*** bio->bi_max_vecs: %u\n",
646                                         bio->bi_max_vecs);
647                         pr_debug("*** bio->bi_vcnt: %u\n",
648                                         bio->bi_vcnt);
649
650                         bio = iblock_get_bio(task, ib_req, ib_dev, &ret,
651                                                 block_lba, sg_num);
652                         if (!bio)
653                                 goto fail;
654
655                         tbio = tbio->bi_next = bio;
656                         pr_debug("-----------------> Added +1 bio: %p to"
657                                 " list, Going to again\n", bio);
658                         goto again;
659                 }
660                 /* Always in 512 byte units for Linux/Block */
661                 block_lba += sg->length >> IBLOCK_LBA_SHIFT;
662                 sg_num--;
663                 pr_debug("task: %p bio-add_page() passed!, decremented"
664                         " sg_num to %u\n", task, sg_num);
665                 pr_debug("task: %p bio_add_page() passed!, increased lba"
666                          " to %llu\n", task, (unsigned long long)block_lba);
667                 pr_debug("task: %p bio_add_page() passed!, bio->bi_vcnt:"
668                                 " %u\n", task, bio->bi_vcnt);
669         }
670
671         return 0;
672 fail:
673         while (hbio) {
674                 bio = hbio;
675                 hbio = hbio->bi_next;
676                 bio->bi_next = NULL;
677                 bio_put(bio);
678         }
679         return ret;
680 }
681
682 static unsigned char *iblock_get_cdb(struct se_task *task)
683 {
684         return IBLOCK_REQ(task)->ib_scsi_cdb;
685 }
686
687 static u32 iblock_get_device_rev(struct se_device *dev)
688 {
689         return SCSI_SPC_2; /* Returns SPC-3 in Initiator Data */
690 }
691
692 static u32 iblock_get_device_type(struct se_device *dev)
693 {
694         return TYPE_DISK;
695 }
696
697 static sector_t iblock_get_blocks(struct se_device *dev)
698 {
699         struct iblock_dev *ibd = dev->dev_ptr;
700         struct block_device *bd = ibd->ibd_bd;
701         struct request_queue *q = bdev_get_queue(bd);
702
703         return iblock_emulate_read_cap_with_block_size(dev, bd, q);
704 }
705
706 static void iblock_bio_done(struct bio *bio, int err)
707 {
708         struct se_task *task = bio->bi_private;
709         struct iblock_req *ibr = IBLOCK_REQ(task);
710         /*
711          * Set -EIO if !BIO_UPTODATE and the passed is still err=0
712          */
713         if (!test_bit(BIO_UPTODATE, &bio->bi_flags) && !err)
714                 err = -EIO;
715
716         if (err != 0) {
717                 pr_err("test_bit(BIO_UPTODATE) failed for bio: %p,"
718                         " err: %d\n", bio, err);
719                 /*
720                  * Bump the ib_bio_err_cnt and release bio.
721                  */
722                 atomic_inc(&ibr->ib_bio_err_cnt);
723                 smp_mb__after_atomic_inc();
724                 bio_put(bio);
725                 /*
726                  * Wait to complete the task until the last bio as completed.
727                  */
728                 if (!atomic_dec_and_test(&ibr->ib_bio_cnt))
729                         return;
730
731                 ibr->ib_bio = NULL;
732                 transport_complete_task(task, 0);
733                 return;
734         }
735         pr_debug("done[%p] bio: %p task_lba: %llu bio_lba: %llu err=%d\n",
736                  task, bio, task->task_lba, (unsigned long long)bio->bi_sector, err);
737         /*
738          * bio_put() will call iblock_bio_destructor() to release the bio back
739          * to ibr->ib_bio_set.
740          */
741         bio_put(bio);
742         /*
743          * Wait to complete the task until the last bio as completed.
744          */
745         if (!atomic_dec_and_test(&ibr->ib_bio_cnt))
746                 return;
747         /*
748          * Return GOOD status for task if zero ib_bio_err_cnt exists.
749          */
750         ibr->ib_bio = NULL;
751         transport_complete_task(task, (!atomic_read(&ibr->ib_bio_err_cnt)));
752 }
753
754 static struct se_subsystem_api iblock_template = {
755         .name                   = "iblock",
756         .owner                  = THIS_MODULE,
757         .transport_type         = TRANSPORT_PLUGIN_VHBA_PDEV,
758         .map_data_SG            = iblock_map_data_SG,
759         .attach_hba             = iblock_attach_hba,
760         .detach_hba             = iblock_detach_hba,
761         .allocate_virtdevice    = iblock_allocate_virtdevice,
762         .create_virtdevice      = iblock_create_virtdevice,
763         .free_device            = iblock_free_device,
764         .dpo_emulated           = iblock_emulated_dpo,
765         .fua_write_emulated     = iblock_emulated_fua_write,
766         .fua_read_emulated      = iblock_emulated_fua_read,
767         .write_cache_emulated   = iblock_emulated_write_cache,
768         .alloc_task             = iblock_alloc_task,
769         .do_task                = iblock_do_task,
770         .do_discard             = iblock_do_discard,
771         .do_sync_cache          = iblock_emulate_sync_cache,
772         .free_task              = iblock_free_task,
773         .check_configfs_dev_params = iblock_check_configfs_dev_params,
774         .set_configfs_dev_params = iblock_set_configfs_dev_params,
775         .show_configfs_dev_params = iblock_show_configfs_dev_params,
776         .get_cdb                = iblock_get_cdb,
777         .get_device_rev         = iblock_get_device_rev,
778         .get_device_type        = iblock_get_device_type,
779         .get_blocks             = iblock_get_blocks,
780 };
781
782 static int __init iblock_module_init(void)
783 {
784         return transport_subsystem_register(&iblock_template);
785 }
786
787 static void iblock_module_exit(void)
788 {
789         transport_subsystem_release(&iblock_template);
790 }
791
792 MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin");
793 MODULE_AUTHOR("nab@Linux-iSCSI.org");
794 MODULE_LICENSE("GPL");
795
796 module_init(iblock_module_init);
797 module_exit(iblock_module_exit);