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target_core_iblock.c
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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 <[email protected]>
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 #include <asm/unaligned.h>
44 
45 #include <target/target_core_base.h>
46 #include <target/target_core_backend.h>
47 
48 #include "target_core_iblock.h"
49 
50 #define IBLOCK_MAX_BIO_PER_TASK 32 /* max # of bios to submit at a time */
51 #define IBLOCK_BIO_POOL_SIZE 128
52 
53 static struct se_subsystem_api iblock_template;
54 
55 static void iblock_bio_done(struct bio *, int);
56 
57 /* iblock_attach_hba(): (Part of se_subsystem_api_t template)
58  *
59  *
60  */
61 static int iblock_attach_hba(struct se_hba *hba, u32 host_id)
62 {
63  pr_debug("CORE_HBA[%d] - TCM iBlock HBA Driver %s on"
64  " Generic Target Core Stack %s\n", hba->hba_id,
65  IBLOCK_VERSION, TARGET_CORE_MOD_VERSION);
66  return 0;
67 }
68 
69 static void iblock_detach_hba(struct se_hba *hba)
70 {
71 }
72 
73 static void *iblock_allocate_virtdevice(struct se_hba *hba, const char *name)
74 {
75  struct iblock_dev *ib_dev = NULL;
76 
77  ib_dev = kzalloc(sizeof(struct iblock_dev), GFP_KERNEL);
78  if (!ib_dev) {
79  pr_err("Unable to allocate struct iblock_dev\n");
80  return NULL;
81  }
82 
83  pr_debug( "IBLOCK: Allocated ib_dev for %s\n", name);
84 
85  return ib_dev;
86 }
87 
88 static struct se_device *iblock_create_virtdevice(
89  struct se_hba *hba,
90  struct se_subsystem_dev *se_dev,
91  void *p)
92 {
93  struct iblock_dev *ib_dev = p;
94  struct se_device *dev;
95  struct se_dev_limits dev_limits;
96  struct block_device *bd = NULL;
97  struct request_queue *q;
98  struct queue_limits *limits;
99  u32 dev_flags = 0;
100  fmode_t mode;
101  int ret = -EINVAL;
102 
103  if (!ib_dev) {
104  pr_err("Unable to locate struct iblock_dev parameter\n");
105  return ERR_PTR(ret);
106  }
107  memset(&dev_limits, 0, sizeof(struct se_dev_limits));
108 
109  ib_dev->ibd_bio_set = bioset_create(IBLOCK_BIO_POOL_SIZE, 0);
110  if (!ib_dev->ibd_bio_set) {
111  pr_err("IBLOCK: Unable to create bioset()\n");
112  return ERR_PTR(-ENOMEM);
113  }
114  pr_debug("IBLOCK: Created bio_set()\n");
115  /*
116  * iblock_check_configfs_dev_params() ensures that ib_dev->ibd_udev_path
117  * must already have been set in order for echo 1 > $HBA/$DEV/enable to run.
118  */
119  pr_debug( "IBLOCK: Claiming struct block_device: %s\n",
120  ib_dev->ibd_udev_path);
121 
122  mode = FMODE_READ|FMODE_EXCL;
123  if (!ib_dev->ibd_readonly)
124  mode |= FMODE_WRITE;
125 
126  bd = blkdev_get_by_path(ib_dev->ibd_udev_path, mode, ib_dev);
127  if (IS_ERR(bd)) {
128  ret = PTR_ERR(bd);
129  goto failed;
130  }
131  /*
132  * Setup the local scope queue_limits from struct request_queue->limits
133  * to pass into transport_add_device_to_core_hba() as struct se_dev_limits.
134  */
135  q = bdev_get_queue(bd);
136  limits = &dev_limits.limits;
137  limits->logical_block_size = bdev_logical_block_size(bd);
138  limits->max_hw_sectors = UINT_MAX;
139  limits->max_sectors = UINT_MAX;
140  dev_limits.hw_queue_depth = q->nr_requests;
141  dev_limits.queue_depth = q->nr_requests;
142 
143  ib_dev->ibd_bd = bd;
144 
145  dev = transport_add_device_to_core_hba(hba,
146  &iblock_template, se_dev, dev_flags, ib_dev,
147  &dev_limits, "IBLOCK", IBLOCK_VERSION);
148  if (!dev)
149  goto failed;
150 
151  /*
152  * Check if the underlying struct block_device request_queue supports
153  * the QUEUE_FLAG_DISCARD bit for UNMAP/WRITE_SAME in SCSI + TRIM
154  * in ATA and we need to set TPE=1
155  */
156  if (blk_queue_discard(q)) {
157  dev->se_sub_dev->se_dev_attrib.max_unmap_lba_count =
158  q->limits.max_discard_sectors;
159  /*
160  * Currently hardcoded to 1 in Linux/SCSI code..
161  */
162  dev->se_sub_dev->se_dev_attrib.max_unmap_block_desc_count = 1;
163  dev->se_sub_dev->se_dev_attrib.unmap_granularity =
164  q->limits.discard_granularity >> 9;
165  dev->se_sub_dev->se_dev_attrib.unmap_granularity_alignment =
166  q->limits.discard_alignment;
167 
168  pr_debug("IBLOCK: BLOCK Discard support available,"
169  " disabled by default\n");
170  }
171 
172  if (blk_queue_nonrot(q))
173  dev->se_sub_dev->se_dev_attrib.is_nonrot = 1;
174 
175  return dev;
176 
177 failed:
178  if (ib_dev->ibd_bio_set) {
179  bioset_free(ib_dev->ibd_bio_set);
180  ib_dev->ibd_bio_set = NULL;
181  }
182  ib_dev->ibd_bd = NULL;
183  return ERR_PTR(ret);
184 }
185 
186 static void iblock_free_device(void *p)
187 {
188  struct iblock_dev *ib_dev = p;
189 
190  if (ib_dev->ibd_bd != NULL)
191  blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
192  if (ib_dev->ibd_bio_set != NULL)
193  bioset_free(ib_dev->ibd_bio_set);
194  kfree(ib_dev);
195 }
196 
197 static unsigned long long iblock_emulate_read_cap_with_block_size(
198  struct se_device *dev,
199  struct block_device *bd,
200  struct request_queue *q)
201 {
202  unsigned long long blocks_long = (div_u64(i_size_read(bd->bd_inode),
203  bdev_logical_block_size(bd)) - 1);
204  u32 block_size = bdev_logical_block_size(bd);
205 
206  if (block_size == dev->se_sub_dev->se_dev_attrib.block_size)
207  return blocks_long;
208 
209  switch (block_size) {
210  case 4096:
211  switch (dev->se_sub_dev->se_dev_attrib.block_size) {
212  case 2048:
213  blocks_long <<= 1;
214  break;
215  case 1024:
216  blocks_long <<= 2;
217  break;
218  case 512:
219  blocks_long <<= 3;
220  default:
221  break;
222  }
223  break;
224  case 2048:
225  switch (dev->se_sub_dev->se_dev_attrib.block_size) {
226  case 4096:
227  blocks_long >>= 1;
228  break;
229  case 1024:
230  blocks_long <<= 1;
231  break;
232  case 512:
233  blocks_long <<= 2;
234  break;
235  default:
236  break;
237  }
238  break;
239  case 1024:
240  switch (dev->se_sub_dev->se_dev_attrib.block_size) {
241  case 4096:
242  blocks_long >>= 2;
243  break;
244  case 2048:
245  blocks_long >>= 1;
246  break;
247  case 512:
248  blocks_long <<= 1;
249  break;
250  default:
251  break;
252  }
253  break;
254  case 512:
255  switch (dev->se_sub_dev->se_dev_attrib.block_size) {
256  case 4096:
257  blocks_long >>= 3;
258  break;
259  case 2048:
260  blocks_long >>= 2;
261  break;
262  case 1024:
263  blocks_long >>= 1;
264  break;
265  default:
266  break;
267  }
268  break;
269  default:
270  break;
271  }
272 
273  return blocks_long;
274 }
275 
276 static void iblock_end_io_flush(struct bio *bio, int err)
277 {
278  struct se_cmd *cmd = bio->bi_private;
279 
280  if (err)
281  pr_err("IBLOCK: cache flush failed: %d\n", err);
282 
283  if (cmd) {
284  if (err) {
285  cmd->scsi_sense_reason =
286  TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
287  target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
288  } else {
289  target_complete_cmd(cmd, SAM_STAT_GOOD);
290  }
291  }
292 
293  bio_put(bio);
294 }
295 
296 /*
297  * Implement SYCHRONIZE CACHE. Note that we can't handle lba ranges and must
298  * always flush the whole cache.
299  */
300 static int iblock_execute_sync_cache(struct se_cmd *cmd)
301 {
302  struct iblock_dev *ib_dev = cmd->se_dev->dev_ptr;
303  int immed = (cmd->t_task_cdb[1] & 0x2);
304  struct bio *bio;
305 
306  /*
307  * If the Immediate bit is set, queue up the GOOD response
308  * for this SYNCHRONIZE_CACHE op.
309  */
310  if (immed)
311  target_complete_cmd(cmd, SAM_STAT_GOOD);
312 
313  bio = bio_alloc(GFP_KERNEL, 0);
314  bio->bi_end_io = iblock_end_io_flush;
315  bio->bi_bdev = ib_dev->ibd_bd;
316  if (!immed)
317  bio->bi_private = cmd;
318  submit_bio(WRITE_FLUSH, bio);
319  return 0;
320 }
321 
322 static int iblock_execute_unmap(struct se_cmd *cmd)
323 {
324  struct se_device *dev = cmd->se_dev;
325  struct iblock_dev *ibd = dev->dev_ptr;
326  unsigned char *buf, *ptr = NULL;
327  sector_t lba;
328  int size;
329  u32 range;
330  int ret = 0;
331  int dl, bd_dl;
332 
333  if (cmd->data_length < 8) {
334  pr_warn("UNMAP parameter list length %u too small\n",
335  cmd->data_length);
336  cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
337  return -EINVAL;
338  }
339 
340  buf = transport_kmap_data_sg(cmd);
341 
342  dl = get_unaligned_be16(&buf[0]);
343  bd_dl = get_unaligned_be16(&buf[2]);
344 
345  size = cmd->data_length - 8;
346  if (bd_dl > size)
347  pr_warn("UNMAP parameter list length %u too small, ignoring bd_dl %u\n",
348  cmd->data_length, bd_dl);
349  else
350  size = bd_dl;
351 
352  if (size / 16 > dev->se_sub_dev->se_dev_attrib.max_unmap_block_desc_count) {
353  cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
354  ret = -EINVAL;
355  goto err;
356  }
357 
358  /* First UNMAP block descriptor starts at 8 byte offset */
359  ptr = &buf[8];
360  pr_debug("UNMAP: Sub: %s Using dl: %u bd_dl: %u size: %u"
361  " ptr: %p\n", dev->transport->name, dl, bd_dl, size, ptr);
362 
363  while (size >= 16) {
364  lba = get_unaligned_be64(&ptr[0]);
365  range = get_unaligned_be32(&ptr[8]);
366  pr_debug("UNMAP: Using lba: %llu and range: %u\n",
367  (unsigned long long)lba, range);
368 
369  if (range > dev->se_sub_dev->se_dev_attrib.max_unmap_lba_count) {
370  cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
371  ret = -EINVAL;
372  goto err;
373  }
374 
375  if (lba + range > dev->transport->get_blocks(dev) + 1) {
376  cmd->scsi_sense_reason = TCM_ADDRESS_OUT_OF_RANGE;
377  ret = -EINVAL;
378  goto err;
379  }
380 
381  ret = blkdev_issue_discard(ibd->ibd_bd, lba, range,
382  GFP_KERNEL, 0);
383  if (ret < 0) {
384  pr_err("blkdev_issue_discard() failed: %d\n",
385  ret);
386  goto err;
387  }
388 
389  ptr += 16;
390  size -= 16;
391  }
392 
393 err:
394  transport_kunmap_data_sg(cmd);
395  if (!ret)
396  target_complete_cmd(cmd, GOOD);
397  return ret;
398 }
399 
400 static int iblock_execute_write_same(struct se_cmd *cmd)
401 {
402  struct iblock_dev *ibd = cmd->se_dev->dev_ptr;
403  int ret;
404 
405  ret = blkdev_issue_discard(ibd->ibd_bd, cmd->t_task_lba,
406  spc_get_write_same_sectors(cmd), GFP_KERNEL,
407  0);
408  if (ret < 0) {
409  pr_debug("blkdev_issue_discard() failed for WRITE_SAME\n");
410  return ret;
411  }
412 
413  target_complete_cmd(cmd, GOOD);
414  return 0;
415 }
416 
417 enum {
418  Opt_udev_path, Opt_readonly, Opt_force, Opt_err
419 };
420 
421 static match_table_t tokens = {
422  {Opt_udev_path, "udev_path=%s"},
423  {Opt_readonly, "readonly=%d"},
424  {Opt_force, "force=%d"},
425  {Opt_err, NULL}
426 };
427 
428 static ssize_t iblock_set_configfs_dev_params(struct se_hba *hba,
429  struct se_subsystem_dev *se_dev,
430  const char *page, ssize_t count)
431 {
432  struct iblock_dev *ib_dev = se_dev->se_dev_su_ptr;
433  char *orig, *ptr, *arg_p, *opts;
434  substring_t args[MAX_OPT_ARGS];
435  int ret = 0, token;
436  unsigned long tmp_readonly;
437 
438  opts = kstrdup(page, GFP_KERNEL);
439  if (!opts)
440  return -ENOMEM;
441 
442  orig = opts;
443 
444  while ((ptr = strsep(&opts, ",\n")) != NULL) {
445  if (!*ptr)
446  continue;
447 
448  token = match_token(ptr, tokens, args);
449  switch (token) {
450  case Opt_udev_path:
451  if (ib_dev->ibd_bd) {
452  pr_err("Unable to set udev_path= while"
453  " ib_dev->ibd_bd exists\n");
454  ret = -EEXIST;
455  goto out;
456  }
457  if (match_strlcpy(ib_dev->ibd_udev_path, &args[0],
458  SE_UDEV_PATH_LEN) == 0) {
459  ret = -EINVAL;
460  break;
461  }
462  pr_debug("IBLOCK: Referencing UDEV path: %s\n",
463  ib_dev->ibd_udev_path);
464  ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH;
465  break;
466  case Opt_readonly:
467  arg_p = match_strdup(&args[0]);
468  if (!arg_p) {
469  ret = -ENOMEM;
470  break;
471  }
472  ret = strict_strtoul(arg_p, 0, &tmp_readonly);
473  kfree(arg_p);
474  if (ret < 0) {
475  pr_err("strict_strtoul() failed for"
476  " readonly=\n");
477  goto out;
478  }
479  ib_dev->ibd_readonly = tmp_readonly;
480  pr_debug("IBLOCK: readonly: %d\n", ib_dev->ibd_readonly);
481  break;
482  case Opt_force:
483  break;
484  default:
485  break;
486  }
487  }
488 
489 out:
490  kfree(orig);
491  return (!ret) ? count : ret;
492 }
493 
494 static ssize_t iblock_check_configfs_dev_params(
495  struct se_hba *hba,
496  struct se_subsystem_dev *se_dev)
497 {
498  struct iblock_dev *ibd = se_dev->se_dev_su_ptr;
499 
500  if (!(ibd->ibd_flags & IBDF_HAS_UDEV_PATH)) {
501  pr_err("Missing udev_path= parameters for IBLOCK\n");
502  return -EINVAL;
503  }
504 
505  return 0;
506 }
507 
508 static ssize_t iblock_show_configfs_dev_params(
509  struct se_hba *hba,
510  struct se_subsystem_dev *se_dev,
511  char *b)
512 {
513  struct iblock_dev *ibd = se_dev->se_dev_su_ptr;
514  struct block_device *bd = ibd->ibd_bd;
515  char buf[BDEVNAME_SIZE];
516  ssize_t bl = 0;
517 
518  if (bd)
519  bl += sprintf(b + bl, "iBlock device: %s",
520  bdevname(bd, buf));
521  if (ibd->ibd_flags & IBDF_HAS_UDEV_PATH)
522  bl += sprintf(b + bl, " UDEV PATH: %s",
523  ibd->ibd_udev_path);
524  bl += sprintf(b + bl, " readonly: %d\n", ibd->ibd_readonly);
525 
526  bl += sprintf(b + bl, " ");
527  if (bd) {
528  bl += sprintf(b + bl, "Major: %d Minor: %d %s\n",
529  MAJOR(bd->bd_dev), MINOR(bd->bd_dev), (!bd->bd_contains) ?
530  "" : (bd->bd_holder == ibd) ?
531  "CLAIMED: IBLOCK" : "CLAIMED: OS");
532  } else {
533  bl += sprintf(b + bl, "Major: 0 Minor: 0\n");
534  }
535 
536  return bl;
537 }
538 
539 static void iblock_complete_cmd(struct se_cmd *cmd)
540 {
541  struct iblock_req *ibr = cmd->priv;
542  u8 status;
543 
544  if (!atomic_dec_and_test(&ibr->pending))
545  return;
546 
547  if (atomic_read(&ibr->ib_bio_err_cnt))
548  status = SAM_STAT_CHECK_CONDITION;
549  else
550  status = SAM_STAT_GOOD;
551 
552  target_complete_cmd(cmd, status);
553  kfree(ibr);
554 }
555 
556 static struct bio *
557 iblock_get_bio(struct se_cmd *cmd, sector_t lba, u32 sg_num)
558 {
559  struct iblock_dev *ib_dev = cmd->se_dev->dev_ptr;
560  struct bio *bio;
561 
562  /*
563  * Only allocate as many vector entries as the bio code allows us to,
564  * we'll loop later on until we have handled the whole request.
565  */
566  if (sg_num > BIO_MAX_PAGES)
567  sg_num = BIO_MAX_PAGES;
568 
569  bio = bio_alloc_bioset(GFP_NOIO, sg_num, ib_dev->ibd_bio_set);
570  if (!bio) {
571  pr_err("Unable to allocate memory for bio\n");
572  return NULL;
573  }
574 
575  bio->bi_bdev = ib_dev->ibd_bd;
576  bio->bi_private = cmd;
577  bio->bi_end_io = &iblock_bio_done;
578  bio->bi_sector = lba;
579  return bio;
580 }
581 
582 static void iblock_submit_bios(struct bio_list *list, int rw)
583 {
584  struct blk_plug plug;
585  struct bio *bio;
586 
587  blk_start_plug(&plug);
588  while ((bio = bio_list_pop(list)))
589  submit_bio(rw, bio);
590  blk_finish_plug(&plug);
591 }
592 
593 static int iblock_execute_rw(struct se_cmd *cmd)
594 {
595  struct scatterlist *sgl = cmd->t_data_sg;
596  u32 sgl_nents = cmd->t_data_nents;
597  enum dma_data_direction data_direction = cmd->data_direction;
598  struct se_device *dev = cmd->se_dev;
599  struct iblock_req *ibr;
600  struct bio *bio;
601  struct bio_list list;
602  struct scatterlist *sg;
603  u32 sg_num = sgl_nents;
604  sector_t block_lba;
605  unsigned bio_cnt;
606  int rw;
607  int i;
608 
609  if (data_direction == DMA_TO_DEVICE) {
610  /*
611  * Force data to disk if we pretend to not have a volatile
612  * write cache, or the initiator set the Force Unit Access bit.
613  */
614  if (dev->se_sub_dev->se_dev_attrib.emulate_write_cache == 0 ||
615  (dev->se_sub_dev->se_dev_attrib.emulate_fua_write > 0 &&
616  (cmd->se_cmd_flags & SCF_FUA)))
617  rw = WRITE_FUA;
618  else
619  rw = WRITE;
620  } else {
621  rw = READ;
622  }
623 
624  /*
625  * Convert the blocksize advertised to the initiator to the 512 byte
626  * units unconditionally used by the Linux block layer.
627  */
628  if (dev->se_sub_dev->se_dev_attrib.block_size == 4096)
629  block_lba = (cmd->t_task_lba << 3);
630  else if (dev->se_sub_dev->se_dev_attrib.block_size == 2048)
631  block_lba = (cmd->t_task_lba << 2);
632  else if (dev->se_sub_dev->se_dev_attrib.block_size == 1024)
633  block_lba = (cmd->t_task_lba << 1);
634  else if (dev->se_sub_dev->se_dev_attrib.block_size == 512)
635  block_lba = cmd->t_task_lba;
636  else {
637  pr_err("Unsupported SCSI -> BLOCK LBA conversion:"
638  " %u\n", dev->se_sub_dev->se_dev_attrib.block_size);
639  cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
640  return -ENOSYS;
641  }
642 
643  ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
644  if (!ibr)
645  goto fail;
646  cmd->priv = ibr;
647 
648  if (!sgl_nents) {
649  atomic_set(&ibr->pending, 1);
650  iblock_complete_cmd(cmd);
651  return 0;
652  }
653 
654  bio = iblock_get_bio(cmd, block_lba, sgl_nents);
655  if (!bio)
656  goto fail_free_ibr;
657 
658  bio_list_init(&list);
659  bio_list_add(&list, bio);
660 
661  atomic_set(&ibr->pending, 2);
662  bio_cnt = 1;
663 
664  for_each_sg(sgl, sg, sgl_nents, i) {
665  /*
666  * XXX: if the length the device accepts is shorter than the
667  * length of the S/G list entry this will cause and
668  * endless loop. Better hope no driver uses huge pages.
669  */
670  while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
671  != sg->length) {
672  if (bio_cnt >= IBLOCK_MAX_BIO_PER_TASK) {
673  iblock_submit_bios(&list, rw);
674  bio_cnt = 0;
675  }
676 
677  bio = iblock_get_bio(cmd, block_lba, sg_num);
678  if (!bio)
679  goto fail_put_bios;
680 
681  atomic_inc(&ibr->pending);
682  bio_list_add(&list, bio);
683  bio_cnt++;
684  }
685 
686  /* Always in 512 byte units for Linux/Block */
687  block_lba += sg->length >> IBLOCK_LBA_SHIFT;
688  sg_num--;
689  }
690 
691  iblock_submit_bios(&list, rw);
692  iblock_complete_cmd(cmd);
693  return 0;
694 
695 fail_put_bios:
696  while ((bio = bio_list_pop(&list)))
697  bio_put(bio);
698 fail_free_ibr:
699  kfree(ibr);
700  cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
701 fail:
702  return -ENOMEM;
703 }
704 
705 static u32 iblock_get_device_rev(struct se_device *dev)
706 {
707  return SCSI_SPC_2; /* Returns SPC-3 in Initiator Data */
708 }
709 
710 static u32 iblock_get_device_type(struct se_device *dev)
711 {
712  return TYPE_DISK;
713 }
714 
715 static sector_t iblock_get_blocks(struct se_device *dev)
716 {
717  struct iblock_dev *ibd = dev->dev_ptr;
718  struct block_device *bd = ibd->ibd_bd;
719  struct request_queue *q = bdev_get_queue(bd);
720 
721  return iblock_emulate_read_cap_with_block_size(dev, bd, q);
722 }
723 
724 static void iblock_bio_done(struct bio *bio, int err)
725 {
726  struct se_cmd *cmd = bio->bi_private;
727  struct iblock_req *ibr = cmd->priv;
728 
729  /*
730  * Set -EIO if !BIO_UPTODATE and the passed is still err=0
731  */
732  if (!test_bit(BIO_UPTODATE, &bio->bi_flags) && !err)
733  err = -EIO;
734 
735  if (err != 0) {
736  pr_err("test_bit(BIO_UPTODATE) failed for bio: %p,"
737  " err: %d\n", bio, err);
738  /*
739  * Bump the ib_bio_err_cnt and release bio.
740  */
741  atomic_inc(&ibr->ib_bio_err_cnt);
742  smp_mb__after_atomic_inc();
743  }
744 
745  bio_put(bio);
746 
747  iblock_complete_cmd(cmd);
748 }
749 
750 static struct spc_ops iblock_spc_ops = {
751  .execute_rw = iblock_execute_rw,
752  .execute_sync_cache = iblock_execute_sync_cache,
753  .execute_write_same = iblock_execute_write_same,
754  .execute_unmap = iblock_execute_unmap,
755 };
756 
757 static int iblock_parse_cdb(struct se_cmd *cmd)
758 {
759  return sbc_parse_cdb(cmd, &iblock_spc_ops);
760 }
761 
762 static struct se_subsystem_api iblock_template = {
763  .name = "iblock",
764  .owner = THIS_MODULE,
765  .transport_type = TRANSPORT_PLUGIN_VHBA_PDEV,
766  .attach_hba = iblock_attach_hba,
767  .detach_hba = iblock_detach_hba,
768  .allocate_virtdevice = iblock_allocate_virtdevice,
769  .create_virtdevice = iblock_create_virtdevice,
770  .free_device = iblock_free_device,
771  .parse_cdb = iblock_parse_cdb,
772  .check_configfs_dev_params = iblock_check_configfs_dev_params,
773  .set_configfs_dev_params = iblock_set_configfs_dev_params,
774  .show_configfs_dev_params = iblock_show_configfs_dev_params,
775  .get_device_rev = iblock_get_device_rev,
776  .get_device_type = iblock_get_device_type,
777  .get_blocks = iblock_get_blocks,
778 };
779 
780 static int __init iblock_module_init(void)
781 {
782  return transport_subsystem_register(&iblock_template);
783 }
784 
785 static void iblock_module_exit(void)
786 {
787  transport_subsystem_release(&iblock_template);
788 }
789 
790 MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin");
791 MODULE_AUTHOR("[email protected]");
792 MODULE_LICENSE("GPL");
793 
794 module_init(iblock_module_init);
795 module_exit(iblock_module_exit);
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