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);