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