drivers/target/target_core_iblock.c

   1 /*******************************************************************************
   2  * Filename:  target_core_iblock.c
   3  *
   4  * This file contains the Storage Engine  <-> Linux BlockIO transport
   5  * specific functions.
   6  *
   7  * Copyright (c) 2003, 2004, 2005 PyX Technologies, Inc.
   8  * Copyright (c) 2005, 2006, 2007 SBE, Inc.
   9  * Copyright (c) 2007-2010 Rising Tide Systems
  10  * Copyright (c) 2008-2010 Linux-iSCSI.org
  11  *
  12  * Nicholas A. Bellinger <nab@kernel.org>
  13  *
  14  * This program is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU General Public License as published by
  16  * the Free Software Foundation; either version 2 of the License, or
  17  * (at your option) any later version.
  18  *
  19  * This program is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  * GNU General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU General Public License
  25  * along with this program; if not, write to the Free Software
  26  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  27  *
  28  ******************************************************************************/
  29
  30 #include <linux/version.h>
  31 #include <linux/string.h>
  32 #include <linux/parser.h>
  33 #include <linux/timer.h>
  34 #include <linux/fs.h>
  35 #include <linux/blkdev.h>
  36 #include <linux/slab.h>
  37 #include <linux/spinlock.h>
  38 #include <linux/bio.h>
  39 #include <linux/genhd.h>
  40 #include <linux/file.h>
  41 #include <scsi/scsi.h>
  42 #include <scsi/scsi_host.h>
  43
  44 #include <target/target_core_base.h>
  45 #include <target/target_core_device.h>
  46 #include <target/target_core_transport.h>
  47
  48 #include "target_core_iblock.h"
  49
  50 #if 0
  51 #define DEBUG_IBLOCK(x...) printk(x)
  52 #else
  53 #define DEBUG_IBLOCK(x...)
  54 #endif
  55
  56 static struct se_subsystem_api iblock_template;
  57
  58 static void iblock_bio_done(struct bio *, int);
  59
  60 /*      iblock_attach_hba(): (Part of se_subsystem_api_t template)
  61  *
  62  *
  63  */
  64 static int iblock_attach_hba(struct se_hba *hba, u32 host_id)
  65 {
  66         struct iblock_hba *ib_host;
  67
  68         ib_host = kzalloc(sizeof(struct iblock_hba), GFP_KERNEL);
  69         if (!(ib_host)) {
  70                 printk(KERN_ERR "Unable to allocate memory for"
  71                                 " struct iblock_hba\n");
  72                 return -ENOMEM;
  73         }
  74
  75         ib_host->iblock_host_id = host_id;
  76
  77         atomic_set(&hba->left_queue_depth, IBLOCK_HBA_QUEUE_DEPTH);
  78         atomic_set(&hba->max_queue_depth, IBLOCK_HBA_QUEUE_DEPTH);
  79         hba->hba_ptr = (void *) ib_host;
  80
  81         printk(KERN_INFO "CORE_HBA[%d] - TCM iBlock HBA Driver %s on"
  82                 " Generic Target Core Stack %s\n", hba->hba_id,
  83                 IBLOCK_VERSION, TARGET_CORE_MOD_VERSION);
  84
  85         printk(KERN_INFO "CORE_HBA[%d] - Attached iBlock HBA: %u to Generic"
  86                 " Target Core TCQ Depth: %d\n", hba->hba_id,
  87                 ib_host->iblock_host_id, atomic_read(&hba->max_queue_depth));
  88
  89         return 0;
  90 }
  91
  92 static void iblock_detach_hba(struct se_hba *hba)
  93 {
  94         struct iblock_hba *ib_host = hba->hba_ptr;
  95
  96         printk(KERN_INFO "CORE_HBA[%d] - Detached iBlock HBA: %u from Generic"
  97                 " Target Core\n", hba->hba_id, ib_host->iblock_host_id);
  98
  99         kfree(ib_host);
 100         hba->hba_ptr = NULL;
 101 }
 102
 103 static void *iblock_allocate_virtdevice(struct se_hba *hba, const char *name)
 104 {
 105         struct iblock_dev *ib_dev = NULL;
 106         struct iblock_hba *ib_host = hba->hba_ptr;
 107
 108         ib_dev = kzalloc(sizeof(struct iblock_dev), GFP_KERNEL);
 109         if (!(ib_dev)) {
 110                 printk(KERN_ERR "Unable to allocate struct iblock_dev\n");
 111                 return NULL;
 112         }
 113         ib_dev->ibd_host = ib_host;
 114
 115         printk(KERN_INFO  "IBLOCK: Allocated ib_dev for %s\n", name);
 116
 117         return ib_dev;
 118 }
 119
 120 static struct se_device *iblock_create_virtdevice(
 121         struct se_hba *hba,
 122         struct se_subsystem_dev *se_dev,
 123         void *p)
 124 {
 125         struct iblock_dev *ib_dev = p;
 126         struct se_device *dev;
 127         struct se_dev_limits dev_limits;
 128         struct block_device *bd = NULL;
 129         struct request_queue *q;
 130         struct queue_limits *limits;
 131         u32 dev_flags = 0;
 132
 133         if (!(ib_dev)) {
 134                 printk(KERN_ERR "Unable to locate struct iblock_dev parameter\n");
 135                 return 0;
 136         }
 137         memset(&dev_limits, 0, sizeof(struct se_dev_limits));
 138         /*
 139          * These settings need to be made tunable..
 140          */
 141         ib_dev->ibd_bio_set = bioset_create(32, 64);
 142         if (!(ib_dev->ibd_bio_set)) {
 143                 printk(KERN_ERR "IBLOCK: Unable to create bioset()\n");
 144                 return 0;
 145         }
 146         printk(KERN_INFO "IBLOCK: Created bio_set()\n");
 147         /*
 148          * iblock_check_configfs_dev_params() ensures that ib_dev->ibd_udev_path
 149          * must already have been set in order for echo 1 > $HBA/$DEV/enable to run.
 150          */
 151         printk(KERN_INFO  "IBLOCK: Claiming struct block_device: %s\n",
 152                         ib_dev->ibd_udev_path);
 153
 154         bd = blkdev_get_by_path(ib_dev->ibd_udev_path,
 155                                 FMODE_WRITE|FMODE_READ|FMODE_EXCL, ib_dev);
 156         if (IS_ERR(bd))
 157                 goto failed;
 158         /*
 159          * Setup the local scope queue_limits from struct request_queue->limits
 160          * to pass into transport_add_device_to_core_hba() as struct se_dev_limits.
 161          */
 162         q = bdev_get_queue(bd);
 163         limits = &dev_limits.limits;
 164         limits->logical_block_size = bdev_logical_block_size(bd);
 165         limits->max_hw_sectors = queue_max_hw_sectors(q);
 166         limits->max_sectors = queue_max_sectors(q);
 167         dev_limits.hw_queue_depth = IBLOCK_MAX_DEVICE_QUEUE_DEPTH;
 168         dev_limits.queue_depth = IBLOCK_DEVICE_QUEUE_DEPTH;
 169
 170         ib_dev->ibd_major = MAJOR(bd->bd_dev);
 171         ib_dev->ibd_minor = MINOR(bd->bd_dev);
 172         ib_dev->ibd_bd = bd;
 173
 174         dev = transport_add_device_to_core_hba(hba,
 175                         &iblock_template, se_dev, dev_flags, (void *)ib_dev,
 176                         &dev_limits, "IBLOCK", IBLOCK_VERSION);
 177         if (!(dev))
 178                 goto failed;
 179
 180         ib_dev->ibd_depth = dev->queue_depth;
 181
 182         /*
 183          * Check if the underlying struct block_device request_queue supports
 184          * the QUEUE_FLAG_DISCARD bit for UNMAP/WRITE_SAME in SCSI + TRIM
 185          * in ATA and we need to set TPE=1
 186          */
 187         if (blk_queue_discard(bdev_get_queue(bd))) {
 188                 struct request_queue *q = bdev_get_queue(bd);
 189
 190                 DEV_ATTRIB(dev)->max_unmap_lba_count =
 191                                 q->limits.max_discard_sectors;
 192                 /*
 193                  * Currently hardcoded to 1 in Linux/SCSI code..
 194                  */
 195                 DEV_ATTRIB(dev)->max_unmap_block_desc_count = 1;
 196                 DEV_ATTRIB(dev)->unmap_granularity =
 197                                 q->limits.discard_granularity;
 198                 DEV_ATTRIB(dev)->unmap_granularity_alignment =
 199                                 q->limits.discard_alignment;
 200
 201                 printk(KERN_INFO "IBLOCK: BLOCK Discard support available,"
 202                                 " disabled by default\n");
 203         }
 204
 205         return dev;
 206
 207 failed:
 208         if (ib_dev->ibd_bio_set) {
 209                 bioset_free(ib_dev->ibd_bio_set);
 210                 ib_dev->ibd_bio_set = NULL;
 211         }
 212         ib_dev->ibd_bd = NULL;
 213         ib_dev->ibd_major = 0;
 214         ib_dev->ibd_minor = 0;
 215         return NULL;
 216 }
 217
 218 static void iblock_free_device(void *p)
 219 {
 220         struct iblock_dev *ib_dev = p;
 221
 222         if (ib_dev->ibd_bd != NULL)
 223                 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
 224         if (ib_dev->ibd_bio_set != NULL)
 225                 bioset_free(ib_dev->ibd_bio_set);
 226         kfree(ib_dev);
 227 }
 228
 229 static inline struct iblock_req *IBLOCK_REQ(struct se_task *task)
 230 {
 231         return container_of(task, struct iblock_req, ib_task);
 232 }
 233
 234 static struct se_task *
 235 iblock_alloc_task(struct se_cmd *cmd)
 236 {
 237         struct iblock_req *ib_req;
 238
 239         ib_req = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
 240         if (!(ib_req)) {
 241                 printk(KERN_ERR "Unable to allocate memory for struct iblock_req\n");
 242                 return NULL;
 243         }
 244
 245         ib_req->ib_dev = SE_DEV(cmd)->dev_ptr;
 246         atomic_set(&ib_req->ib_bio_cnt, 0);
 247         return &ib_req->ib_task;
 248 }
 249
 250 static unsigned long long iblock_emulate_read_cap_with_block_size(
 251         struct se_device *dev,
 252         struct block_device *bd,
 253         struct request_queue *q)
 254 {
 255         unsigned long long blocks_long = (div_u64(i_size_read(bd->bd_inode),
 256                                         bdev_logical_block_size(bd)) - 1);
 257         u32 block_size = bdev_logical_block_size(bd);
 258
 259         if (block_size == DEV_ATTRIB(dev)->block_size)
 260                 return blocks_long;
 261
 262         switch (block_size) {
 263         case 4096:
 264                 switch (DEV_ATTRIB(dev)->block_size) {
 265                 case 2048:
 266                         blocks_long <<= 1;
 267                         break;
 268                 case 1024:
 269                         blocks_long <<= 2;
 270                         break;
 271                 case 512:
 272                         blocks_long <<= 3;
 273                 default:
 274                         break;
 275                 }
 276                 break;
 277         case 2048:
 278                 switch (DEV_ATTRIB(dev)->block_size) {
 279                 case 4096:
 280                         blocks_long >>= 1;
 281                         break;
 282                 case 1024:
 283                         blocks_long <<= 1;
 284                         break;
 285                 case 512:
 286                         blocks_long <<= 2;
 287                         break;
 288                 default:
 289                         break;
 290                 }
 291                 break;
 292         case 1024:
 293                 switch (DEV_ATTRIB(dev)->block_size) {
 294                 case 4096:
 295                         blocks_long >>= 2;
 296                         break;
 297                 case 2048:
 298                         blocks_long >>= 1;
 299                         break;
 300                 case 512:
 301                         blocks_long <<= 1;
 302                         break;
 303                 default:
 304                         break;
 305                 }
 306                 break;
 307         case 512:
 308                 switch (DEV_ATTRIB(dev)->block_size) {
 309                 case 4096:
 310                         blocks_long >>= 3;
 311                         break;
 312                 case 2048:
 313                         blocks_long >>= 2;
 314                         break;
 315                 case 1024:
 316                         blocks_long >>= 1;
 317                         break;
 318                 default:
 319                         break;
 320                 }
 321                 break;
 322         default:
 323                 break;
 324         }
 325
 326         return blocks_long;
 327 }
 328
 329 /*
 330  * Emulate SYCHRONIZE_CACHE_*
 331  */
 332 static void iblock_emulate_sync_cache(struct se_task *task)
 333 {
 334         struct se_cmd *cmd = TASK_CMD(task);
 335         struct iblock_dev *ib_dev = cmd->se_dev->dev_ptr;
 336         int immed = (T_TASK(cmd)->t_task_cdb[1] & 0x2);
 337         sector_t error_sector;
 338         int ret;
 339
 340         /*
 341          * If the Immediate bit is set, queue up the GOOD response
 342          * for this SYNCHRONIZE_CACHE op
 343          */
 344         if (immed)
 345                 transport_complete_sync_cache(cmd, 1);
 346
 347         /*
 348          * blkdev_issue_flush() does not support a specifying a range, so
 349          * we have to flush the entire cache.
 350          */
 351         ret = blkdev_issue_flush(ib_dev->ibd_bd, GFP_KERNEL, &error_sector);
 352         if (ret != 0) {
 353                 printk(KERN_ERR "IBLOCK: block_issue_flush() failed: %d "
 354                         " error_sector: %llu\n", ret,
 355                         (unsigned long long)error_sector);
 356         }
 357
 358         if (!immed)
 359                 transport_complete_sync_cache(cmd, ret == 0);
 360 }
 361
 362 /*
 363  * Tell TCM Core that we are capable of WriteCache emulation for
 364  * an underlying struct se_device.
 365  */
 366 static int iblock_emulated_write_cache(struct se_device *dev)
 367 {
 368         return 1;
 369 }
 370
 371 static int iblock_emulated_dpo(struct se_device *dev)
 372 {
 373         return 0;
 374 }
 375
 376 /*
 377  * Tell TCM Core that we will be emulating Forced Unit Access (FUA) for WRITEs
 378  * for TYPE_DISK.
 379  */
 380 static int iblock_emulated_fua_write(struct se_device *dev)
 381 {
 382         return 1;
 383 }
 384
 385 static int iblock_emulated_fua_read(struct se_device *dev)
 386 {
 387         return 0;
 388 }
 389
 390 static int iblock_do_task(struct se_task *task)
 391 {
 392         struct se_device *dev = task->task_se_cmd->se_dev;
 393         struct iblock_req *req = IBLOCK_REQ(task);
 394         struct iblock_dev *ibd = (struct iblock_dev *)req->ib_dev;
 395         struct request_queue *q = bdev_get_queue(ibd->ibd_bd);
 396         struct bio *bio = req->ib_bio, *nbio = NULL;
 397         int rw;
 398
 399         if (task->task_data_direction == DMA_TO_DEVICE) {
 400                 /*
 401                  * Force data to disk if we pretend to not have a volatile
 402                  * write cache, or the initiator set the Force Unit Access bit.
 403                  */
 404                 if (DEV_ATTRIB(dev)->emulate_write_cache == 0 ||
 405                     (DEV_ATTRIB(dev)->emulate_fua_write > 0 &&
 406                      T_TASK(task->task_se_cmd)->t_tasks_fua))
 407                         rw = WRITE_FUA;
 408                 else
 409                         rw = WRITE;
 410         } else {
 411                 rw = READ;
 412         }
 413
 414         while (bio) {
 415                 nbio = bio->bi_next;
 416                 bio->bi_next = NULL;
 417                 DEBUG_IBLOCK("Calling submit_bio() task: %p bio: %p"
 418                         " bio->bi_sector: %llu\n", task, bio, bio->bi_sector);
 419
 420                 submit_bio(rw, bio);
 421                 bio = nbio;
 422         }
 423
 424         if (q->unplug_fn)
 425                 q->unplug_fn(q);
 426         return PYX_TRANSPORT_SENT_TO_TRANSPORT;
 427 }
 428
 429 static int iblock_do_discard(struct se_device *dev, sector_t lba, u32 range)
 430 {
 431         struct iblock_dev *ibd = dev->dev_ptr;
 432         struct block_device *bd = ibd->ibd_bd;
 433         int barrier = 0;
 434
 435         return blkdev_issue_discard(bd, lba, range, GFP_KERNEL, barrier);
 436 }
 437
 438 static void iblock_free_task(struct se_task *task)
 439 {
 440         struct iblock_req *req = IBLOCK_REQ(task);
 441         struct bio *bio, *hbio = req->ib_bio;
 442         /*
 443          * We only release the bio(s) here if iblock_bio_done() has not called
 444          * bio_put() -> iblock_bio_destructor().
 445          */
 446         while (hbio != NULL) {
 447                 bio = hbio;
 448                 hbio = hbio->bi_next;
 449                 bio->bi_next = NULL;
 450                 bio_put(bio);
 451         }
 452
 453         kfree(req);
 454 }
 455
 456 enum {
 457         Opt_udev_path, Opt_force, Opt_err
 458 };
 459
 460 static match_table_t tokens = {
 461         {Opt_udev_path, "udev_path=%s"},
 462         {Opt_force, "force=%d"},
 463         {Opt_err, NULL}
 464 };
 465
 466 static ssize_t iblock_set_configfs_dev_params(struct se_hba *hba,
 467                                                struct se_subsystem_dev *se_dev,
 468                                                const char *page, ssize_t count)
 469 {
 470         struct iblock_dev *ib_dev = se_dev->se_dev_su_ptr;
 471         char *orig, *ptr, *opts;
 472         substring_t args[MAX_OPT_ARGS];
 473         int ret = 0, arg, token;
 474
 475         opts = kstrdup(page, GFP_KERNEL);
 476         if (!opts)
 477                 return -ENOMEM;
 478
 479         orig = opts;
 480
 481         while ((ptr = strsep(&opts, ",")) != NULL) {
 482                 if (!*ptr)
 483                         continue;
 484
 485                 token = match_token(ptr, tokens, args);
 486                 switch (token) {
 487                 case Opt_udev_path:
 488                         if (ib_dev->ibd_bd) {
 489                                 printk(KERN_ERR "Unable to set udev_path= while"
 490                                         " ib_dev->ibd_bd exists\n");
 491                                 ret = -EEXIST;
 492                                 goto out;
 493                         }
 494
 495                         ret = snprintf(ib_dev->ibd_udev_path, SE_UDEV_PATH_LEN,
 496                                 "%s", match_strdup(&args[0]));
 497                         printk(KERN_INFO "IBLOCK: Referencing UDEV path: %s\n",
 498                                         ib_dev->ibd_udev_path);
 499                         ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH;
 500                         break;
 501                 case Opt_force:
 502                         match_int(args, &arg);
 503                         ib_dev->ibd_force = arg;
 504                         printk(KERN_INFO "IBLOCK: Set force=%d\n",
 505                                 ib_dev->ibd_force);
 506                         break;
 507                 default:
 508                         break;
 509                 }
 510         }
 511
 512 out:
 513         kfree(orig);
 514         return (!ret) ? count : ret;
 515 }
 516
 517 static ssize_t iblock_check_configfs_dev_params(
 518         struct se_hba *hba,
 519         struct se_subsystem_dev *se_dev)
 520 {
 521         struct iblock_dev *ibd = se_dev->se_dev_su_ptr;
 522
 523         if (!(ibd->ibd_flags & IBDF_HAS_UDEV_PATH)) {
 524                 printk(KERN_ERR "Missing udev_path= parameters for IBLOCK\n");
 525                 return -1;
 526         }
 527
 528         return 0;
 529 }
 530
 531 static ssize_t iblock_show_configfs_dev_params(
 532         struct se_hba *hba,
 533         struct se_subsystem_dev *se_dev,
 534         char *b)
 535 {
 536         struct iblock_dev *ibd = se_dev->se_dev_su_ptr;
 537         struct block_device *bd = ibd->ibd_bd;
 538         char buf[BDEVNAME_SIZE];
 539         ssize_t bl = 0;
 540
 541         if (bd)
 542                 bl += sprintf(b + bl, "iBlock device: %s",
 543                                 bdevname(bd, buf));
 544         if (ibd->ibd_flags & IBDF_HAS_UDEV_PATH) {
 545                 bl += sprintf(b + bl, "  UDEV PATH: %s\n",
 546                                 ibd->ibd_udev_path);
 547         } else
 548                 bl += sprintf(b + bl, "\n");
 549
 550         bl += sprintf(b + bl, "        ");
 551         if (bd) {
 552                 bl += sprintf(b + bl, "Major: %d Minor: %d  %s\n",
 553                         ibd->ibd_major, ibd->ibd_minor, (!bd->bd_contains) ?
 554                         "" : (bd->bd_holder == (struct iblock_dev *)ibd) ?
 555                         "CLAIMED: IBLOCK" : "CLAIMED: OS");
 556         } else {
 557                 bl += sprintf(b + bl, "Major: %d Minor: %d\n",
 558                         ibd->ibd_major, ibd->ibd_minor);
 559         }
 560
 561         return bl;
 562 }
 563
 564 static void iblock_bio_destructor(struct bio *bio)
 565 {
 566         struct se_task *task = bio->bi_private;
 567         struct iblock_dev *ib_dev = task->se_dev->dev_ptr;
 568
 569         bio_free(bio, ib_dev->ibd_bio_set);
 570 }
 571
 572 static struct bio *iblock_get_bio(
 573         struct se_task *task,
 574         struct iblock_req *ib_req,
 575         struct iblock_dev *ib_dev,
 576         int *ret,
 577         sector_t lba,
 578         u32 sg_num)
 579 {
 580         struct bio *bio;
 581
 582         bio = bio_alloc_bioset(GFP_NOIO, sg_num, ib_dev->ibd_bio_set);
 583         if (!(bio)) {
 584                 printk(KERN_ERR "Unable to allocate memory for bio\n");
 585                 *ret = PYX_TRANSPORT_OUT_OF_MEMORY_RESOURCES;
 586                 return NULL;
 587         }
 588
 589         DEBUG_IBLOCK("Allocated bio: %p task_sg_num: %u using ibd_bio_set:"
 590                 " %p\n", bio, task->task_sg_num, ib_dev->ibd_bio_set);
 591         DEBUG_IBLOCK("Allocated bio: %p task_size: %u\n", bio, task->task_size);
 592
 593         bio->bi_bdev = ib_dev->ibd_bd;
 594         bio->bi_private = (void *) task;
 595         bio->bi_destructor = iblock_bio_destructor;
 596         bio->bi_end_io = &iblock_bio_done;
 597         bio->bi_sector = lba;
 598         atomic_inc(&ib_req->ib_bio_cnt);
 599
 600         DEBUG_IBLOCK("Set bio->bi_sector: %llu\n", bio->bi_sector);
 601         DEBUG_IBLOCK("Set ib_req->ib_bio_cnt: %d\n",
 602                         atomic_read(&ib_req->ib_bio_cnt));
 603         return bio;
 604 }
 605
 606 static int iblock_map_task_SG(struct se_task *task)
 607 {
 608         struct se_cmd *cmd = task->task_se_cmd;
 609         struct se_device *dev = SE_DEV(cmd);
 610         struct iblock_dev *ib_dev = task->se_dev->dev_ptr;
 611         struct iblock_req *ib_req = IBLOCK_REQ(task);
 612         struct bio *bio = NULL, *hbio = NULL, *tbio = NULL;
 613         struct scatterlist *sg;
 614         int ret = 0;
 615         u32 i, sg_num = task->task_sg_num;
 616         sector_t block_lba;
 617         /*
 618          * Do starting conversion up from non 512-byte blocksize with
 619          * struct se_task SCSI blocksize into Linux/Block 512 units for BIO.
 620          */
 621         if (DEV_ATTRIB(dev)->block_size == 4096)
 622                 block_lba = (task->task_lba << 3);
 623         else if (DEV_ATTRIB(dev)->block_size == 2048)
 624                 block_lba = (task->task_lba << 2);
 625         else if (DEV_ATTRIB(dev)->block_size == 1024)
 626                 block_lba = (task->task_lba << 1);
 627         else if (DEV_ATTRIB(dev)->block_size == 512)
 628                 block_lba = task->task_lba;
 629         else {
 630                 printk(KERN_ERR "Unsupported SCSI -> BLOCK LBA conversion:"
 631                                 " %u\n", DEV_ATTRIB(dev)->block_size);
 632                 return PYX_TRANSPORT_LU_COMM_FAILURE;
 633         }
 634
 635         bio = iblock_get_bio(task, ib_req, ib_dev, &ret, block_lba, sg_num);
 636         if (!(bio))
 637                 return ret;
 638
 639         ib_req->ib_bio = bio;
 640         hbio = tbio = bio;
 641         /*
 642          * Use fs/bio.c:bio_add_pages() to setup the bio_vec maplist
 643          * from TCM struct se_mem -> task->task_sg -> struct scatterlist memory.
 644          */
 645         for_each_sg(task->task_sg, sg, task->task_sg_num, i) {
 646                 DEBUG_IBLOCK("task: %p bio: %p Calling bio_add_page(): page:"
 647                         " %p len: %u offset: %u\n", task, bio, sg_page(sg),
 648                                 sg->length, sg->offset);
 649 again:
 650                 ret = bio_add_page(bio, sg_page(sg), sg->length, sg->offset);
 651                 if (ret != sg->length) {
 652
 653                         DEBUG_IBLOCK("*** Set bio->bi_sector: %llu\n",
 654                                         bio->bi_sector);
 655                         DEBUG_IBLOCK("** task->task_size: %u\n",
 656                                         task->task_size);
 657                         DEBUG_IBLOCK("*** bio->bi_max_vecs: %u\n",
 658                                         bio->bi_max_vecs);
 659                         DEBUG_IBLOCK("*** bio->bi_vcnt: %u\n",
 660                                         bio->bi_vcnt);
 661
 662                         bio = iblock_get_bio(task, ib_req, ib_dev, &ret,
 663                                                 block_lba, sg_num);
 664                         if (!(bio))
 665                                 goto fail;
 666
 667                         tbio = tbio->bi_next = bio;
 668                         DEBUG_IBLOCK("-----------------> Added +1 bio: %p to"
 669                                 " list, Going to again\n", bio);
 670                         goto again;
 671                 }
 672                 /* Always in 512 byte units for Linux/Block */
 673                 block_lba += sg->length >> IBLOCK_LBA_SHIFT;
 674                 sg_num--;
 675                 DEBUG_IBLOCK("task: %p bio-add_page() passed!, decremented"
 676                         " sg_num to %u\n", task, sg_num);
 677                 DEBUG_IBLOCK("task: %p bio_add_page() passed!, increased lba"
 678                                 " to %llu\n", task, block_lba);
 679                 DEBUG_IBLOCK("task: %p bio_add_page() passed!, bio->bi_vcnt:"
 680                                 " %u\n", task, bio->bi_vcnt);
 681         }
 682
 683         return 0;
 684 fail:
 685         while (hbio) {
 686                 bio = hbio;
 687                 hbio = hbio->bi_next;
 688                 bio->bi_next = NULL;
 689                 bio_put(bio);
 690         }
 691         return ret;
 692 }
 693
 694 static unsigned char *iblock_get_cdb(struct se_task *task)
 695 {
 696         return IBLOCK_REQ(task)->ib_scsi_cdb;
 697 }
 698
 699 static u32 iblock_get_device_rev(struct se_device *dev)
 700 {
 701         return SCSI_SPC_2; /* Returns SPC-3 in Initiator Data */
 702 }
 703
 704 static u32 iblock_get_device_type(struct se_device *dev)
 705 {
 706         return TYPE_DISK;
 707 }
 708
 709 static sector_t iblock_get_blocks(struct se_device *dev)
 710 {
 711         struct iblock_dev *ibd = dev->dev_ptr;
 712         struct block_device *bd = ibd->ibd_bd;
 713         struct request_queue *q = bdev_get_queue(bd);
 714
 715         return iblock_emulate_read_cap_with_block_size(dev, bd, q);
 716 }
 717
 718 static void iblock_bio_done(struct bio *bio, int err)
 719 {
 720         struct se_task *task = bio->bi_private;
 721         struct iblock_req *ibr = IBLOCK_REQ(task);
 722         /*
 723          * Set -EIO if !BIO_UPTODATE and the passed is still err=0
 724          */
 725         if (!(test_bit(BIO_UPTODATE, &bio->bi_flags)) && !(err))
 726                 err = -EIO;
 727
 728         if (err != 0) {
 729                 printk(KERN_ERR "test_bit(BIO_UPTODATE) failed for bio: %p,"
 730                         " err: %d\n", bio, err);
 731                 /*
 732                  * Bump the ib_bio_err_cnt and release bio.
 733                  */
 734                 atomic_inc(&ibr->ib_bio_err_cnt);
 735                 smp_mb__after_atomic_inc();
 736                 bio_put(bio);
 737                 /*
 738                  * Wait to complete the task until the last bio as completed.
 739                  */
 740                 if (!(atomic_dec_and_test(&ibr->ib_bio_cnt)))
 741                         return;
 742
 743                 ibr->ib_bio = NULL;
 744                 transport_complete_task(task, 0);
 745                 return;
 746         }
 747         DEBUG_IBLOCK("done[%p] bio: %p task_lba: %llu bio_lba: %llu err=%d\n",
 748                 task, bio, task->task_lba, bio->bi_sector, err);
 749         /*
 750          * bio_put() will call iblock_bio_destructor() to release the bio back
 751          * to ibr->ib_bio_set.
 752          */
 753         bio_put(bio);
 754         /*
 755          * Wait to complete the task until the last bio as completed.
 756          */
 757         if (!(atomic_dec_and_test(&ibr->ib_bio_cnt)))
 758                 return;
 759         /*
 760          * Return GOOD status for task if zero ib_bio_err_cnt exists.
 761          */
 762         ibr->ib_bio = NULL;
 763         transport_complete_task(task, (!atomic_read(&ibr->ib_bio_err_cnt)));
 764 }
 765
 766 static struct se_subsystem_api iblock_template = {
 767         .name                   = "iblock",
 768         .owner                  = THIS_MODULE,
 769         .transport_type         = TRANSPORT_PLUGIN_VHBA_PDEV,
 770         .map_task_SG            = iblock_map_task_SG,
 771         .attach_hba             = iblock_attach_hba,
 772         .detach_hba             = iblock_detach_hba,
 773         .allocate_virtdevice    = iblock_allocate_virtdevice,
 774         .create_virtdevice      = iblock_create_virtdevice,
 775         .free_device            = iblock_free_device,
 776         .dpo_emulated           = iblock_emulated_dpo,
 777         .fua_write_emulated     = iblock_emulated_fua_write,
 778         .fua_read_emulated      = iblock_emulated_fua_read,
 779         .write_cache_emulated   = iblock_emulated_write_cache,
 780         .alloc_task             = iblock_alloc_task,
 781         .do_task                = iblock_do_task,
 782         .do_discard             = iblock_do_discard,
 783         .do_sync_cache          = iblock_emulate_sync_cache,
 784         .free_task              = iblock_free_task,
 785         .check_configfs_dev_params = iblock_check_configfs_dev_params,
 786         .set_configfs_dev_params = iblock_set_configfs_dev_params,
 787         .show_configfs_dev_params = iblock_show_configfs_dev_params,
 788         .get_cdb                = iblock_get_cdb,
 789         .get_device_rev         = iblock_get_device_rev,
 790         .get_device_type        = iblock_get_device_type,
 791         .get_blocks             = iblock_get_blocks,
 792 };
 793
 794 static int __init iblock_module_init(void)
 795 {
 796         return transport_subsystem_register(&iblock_template);
 797 }
 798
 799 static void iblock_module_exit(void)
 800 {
 801         transport_subsystem_release(&iblock_template);
 802 }
 803
 804 MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin");
 805 MODULE_AUTHOR("nab@Linux-iSCSI.org");
 806 MODULE_LICENSE("GPL");
 807
 808 module_init(iblock_module_init);
 809 module_exit(iblock_module_exit);