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