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 (IS_ERR(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         if (ib_dev->ibd_bd != NULL)
 224                 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
 225         if (ib_dev->ibd_bio_set != NULL)
 226                 bioset_free(ib_dev->ibd_bio_set);
 227         kfree(ib_dev);
 228 }
 229
 230 static inline struct iblock_req *IBLOCK_REQ(struct se_task *task)
 231 {
 232         return container_of(task, struct iblock_req, ib_task);
 233 }
 234
 235 static struct se_task *
 236 iblock_alloc_task(struct se_cmd *cmd)
 237 {
 238         struct iblock_req *ib_req;
 239
 240         ib_req = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
 241         if (!(ib_req)) {
 242                 printk(KERN_ERR "Unable to allocate memory for struct iblock_req\n");
 243                 return NULL;
 244         }
 245
 246         ib_req->ib_dev = SE_DEV(cmd)->dev_ptr;
 247         atomic_set(&ib_req->ib_bio_cnt, 0);
 248         return &ib_req->ib_task;
 249 }
 250
 251 static unsigned long long iblock_emulate_read_cap_with_block_size(
 252         struct se_device *dev,
 253         struct block_device *bd,
 254         struct request_queue *q)
 255 {
 256         unsigned long long blocks_long = (div_u64(i_size_read(bd->bd_inode),
 257                                         bdev_logical_block_size(bd)) - 1);
 258         u32 block_size = bdev_logical_block_size(bd);
 259
 260         if (block_size == DEV_ATTRIB(dev)->block_size)
 261                 return blocks_long;
 262
 263         switch (block_size) {
 264         case 4096:
 265                 switch (DEV_ATTRIB(dev)->block_size) {
 266                 case 2048:
 267                         blocks_long <<= 1;
 268                         break;
 269                 case 1024:
 270                         blocks_long <<= 2;
 271                         break;
 272                 case 512:
 273                         blocks_long <<= 3;
 274                 default:
 275                         break;
 276                 }
 277                 break;
 278         case 2048:
 279                 switch (DEV_ATTRIB(dev)->block_size) {
 280                 case 4096:
 281                         blocks_long >>= 1;
 282                         break;
 283                 case 1024:
 284                         blocks_long <<= 1;
 285                         break;
 286                 case 512:
 287                         blocks_long <<= 2;
 288                         break;
 289                 default:
 290                         break;
 291                 }
 292                 break;
 293         case 1024:
 294                 switch (DEV_ATTRIB(dev)->block_size) {
 295                 case 4096:
 296                         blocks_long >>= 2;
 297                         break;
 298                 case 2048:
 299                         blocks_long >>= 1;
 300                         break;
 301                 case 512:
 302                         blocks_long <<= 1;
 303                         break;
 304                 default:
 305                         break;
 306                 }
 307                 break;
 308         case 512:
 309                 switch (DEV_ATTRIB(dev)->block_size) {
 310                 case 4096:
 311                         blocks_long >>= 3;
 312                         break;
 313                 case 2048:
 314                         blocks_long >>= 2;
 315                         break;
 316                 case 1024:
 317                         blocks_long >>= 1;
 318                         break;
 319                 default:
 320                         break;
 321                 }
 322                 break;
 323         default:
 324                 break;
 325         }
 326
 327         return blocks_long;
 328 }
 329
 330 /*
 331  * Emulate SYCHRONIZE_CACHE_*
 332  */
 333 static void iblock_emulate_sync_cache(struct se_task *task)
 334 {
 335         struct se_cmd *cmd = TASK_CMD(task);
 336         struct iblock_dev *ib_dev = cmd->se_dev->dev_ptr;
 337         int immed = (T_TASK(cmd)->t_task_cdb[1] & 0x2);
 338         sector_t error_sector;
 339         int ret;
 340
 341         /*
 342          * If the Immediate bit is set, queue up the GOOD response
 343          * for this SYNCHRONIZE_CACHE op
 344          */
 345         if (immed)
 346                 transport_complete_sync_cache(cmd, 1);
 347
 348         /*
 349          * blkdev_issue_flush() does not support a specifying a range, so
 350          * we have to flush the entire cache.
 351          */
 352         ret = blkdev_issue_flush(ib_dev->ibd_bd, GFP_KERNEL, &error_sector);
 353         if (ret != 0) {
 354                 printk(KERN_ERR "IBLOCK: block_issue_flush() failed: %d "
 355                         " error_sector: %llu\n", ret,
 356                         (unsigned long long)error_sector);
 357         }
 358
 359         if (!immed)
 360                 transport_complete_sync_cache(cmd, ret == 0);
 361 }
 362
 363 /*
 364  * Tell TCM Core that we are capable of WriteCache emulation for
 365  * an underlying struct se_device.
 366  */
 367 static int iblock_emulated_write_cache(struct se_device *dev)
 368 {
 369         return 1;
 370 }
 371
 372 static int iblock_emulated_dpo(struct se_device *dev)
 373 {
 374         return 0;
 375 }
 376
 377 /*
 378  * Tell TCM Core that we will be emulating Forced Unit Access (FUA) for WRITEs
 379  * for TYPE_DISK.
 380  */
 381 static int iblock_emulated_fua_write(struct se_device *dev)
 382 {
 383         return 1;
 384 }
 385
 386 static int iblock_emulated_fua_read(struct se_device *dev)
 387 {
 388         return 0;
 389 }
 390
 391 static int iblock_do_task(struct se_task *task)
 392 {
 393         struct se_device *dev = task->task_se_cmd->se_dev;
 394         struct iblock_req *req = IBLOCK_REQ(task);
 395         struct iblock_dev *ibd = (struct iblock_dev *)req->ib_dev;
 396         struct request_queue *q = bdev_get_queue(ibd->ibd_bd);
 397         struct bio *bio = req->ib_bio, *nbio = NULL;
 398         int rw;
 399
 400         if (task->task_data_direction == DMA_TO_DEVICE) {
 401                 /*
 402                  * Force data to disk if we pretend to not have a volatile
 403                  * write cache, or the initiator set the Force Unit Access bit.
 404                  */
 405                 if (DEV_ATTRIB(dev)->emulate_write_cache == 0 ||
 406                     (DEV_ATTRIB(dev)->emulate_fua_write > 0 &&
 407                      T_TASK(task->task_se_cmd)->t_tasks_fua))
 408                         rw = WRITE_FUA;
 409                 else
 410                         rw = WRITE;
 411         } else {
 412                 rw = READ;
 413         }
 414
 415         while (bio) {
 416                 nbio = bio->bi_next;
 417                 bio->bi_next = NULL;
 418                 DEBUG_IBLOCK("Calling submit_bio() task: %p bio: %p"
 419                         " bio->bi_sector: %llu\n", task, bio, bio->bi_sector);
 420
 421                 submit_bio(rw, bio);
 422                 bio = nbio;
 423         }
 424
 425         if (q->unplug_fn)
 426                 q->unplug_fn(q);
 427         return PYX_TRANSPORT_SENT_TO_TRANSPORT;
 428 }
 429
 430 static int iblock_do_discard(struct se_device *dev, sector_t lba, u32 range)
 431 {
 432         struct iblock_dev *ibd = dev->dev_ptr;
 433         struct block_device *bd = ibd->ibd_bd;
 434         int barrier = 0;
 435
 436         return blkdev_issue_discard(bd, lba, range, GFP_KERNEL, barrier);
 437 }
 438
 439 static void iblock_free_task(struct se_task *task)
 440 {
 441         struct iblock_req *req = IBLOCK_REQ(task);
 442         struct bio *bio, *hbio = req->ib_bio;
 443         /*
 444          * We only release the bio(s) here if iblock_bio_done() has not called
 445          * bio_put() -> iblock_bio_destructor().
 446          */
 447         while (hbio != NULL) {
 448                 bio = hbio;
 449                 hbio = hbio->bi_next;
 450                 bio->bi_next = NULL;
 451                 bio_put(bio);
 452         }
 453
 454         kfree(req);
 455 }
 456
 457 enum {
 458         Opt_udev_path, Opt_force, Opt_err
 459 };
 460
 461 static match_table_t tokens = {
 462         {Opt_udev_path, "udev_path=%s"},
 463         {Opt_force, "force=%d"},
 464         {Opt_err, NULL}
 465 };
 466
 467 static ssize_t iblock_set_configfs_dev_params(struct se_hba *hba,
 468                                                struct se_subsystem_dev *se_dev,
 469                                                const char *page, ssize_t count)
 470 {
 471         struct iblock_dev *ib_dev = se_dev->se_dev_su_ptr;
 472         char *orig, *ptr, *opts;
 473         substring_t args[MAX_OPT_ARGS];
 474         int ret = 0, arg, token;
 475
 476         opts = kstrdup(page, GFP_KERNEL);
 477         if (!opts)
 478                 return -ENOMEM;
 479
 480         orig = opts;
 481
 482         while ((ptr = strsep(&opts, ",")) != NULL) {
 483                 if (!*ptr)
 484                         continue;
 485
 486                 token = match_token(ptr, tokens, args);
 487                 switch (token) {
 488                 case Opt_udev_path:
 489                         if (ib_dev->ibd_bd) {
 490                                 printk(KERN_ERR "Unable to set udev_path= while"
 491                                         " ib_dev->ibd_bd exists\n");
 492                                 ret = -EEXIST;
 493                                 goto out;
 494                         }
 495
 496                         ret = snprintf(ib_dev->ibd_udev_path, SE_UDEV_PATH_LEN,
 497                                 "%s", match_strdup(&args[0]));
 498                         printk(KERN_INFO "IBLOCK: Referencing UDEV path: %s\n",
 499                                         ib_dev->ibd_udev_path);
 500                         ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH;
 501                         break;
 502                 case Opt_force:
 503                         match_int(args, &arg);
 504                         ib_dev->ibd_force = arg;
 505                         printk(KERN_INFO "IBLOCK: Set force=%d\n",
 506                                 ib_dev->ibd_force);
 507                         break;
 508                 default:
 509                         break;
 510                 }
 511         }
 512
 513 out:
 514         kfree(orig);
 515         return (!ret) ? count : ret;
 516 }
 517
 518 static ssize_t iblock_check_configfs_dev_params(
 519         struct se_hba *hba,
 520         struct se_subsystem_dev *se_dev)
 521 {
 522         struct iblock_dev *ibd = se_dev->se_dev_su_ptr;
 523
 524         if (!(ibd->ibd_flags & IBDF_HAS_UDEV_PATH)) {
 525                 printk(KERN_ERR "Missing udev_path= parameters for IBLOCK\n");
 526                 return -1;
 527         }
 528
 529         return 0;
 530 }
 531
 532 static ssize_t iblock_show_configfs_dev_params(
 533         struct se_hba *hba,
 534         struct se_subsystem_dev *se_dev,
 535         char *b)
 536 {
 537         struct iblock_dev *ibd = se_dev->se_dev_su_ptr;
 538         struct block_device *bd = ibd->ibd_bd;
 539         char buf[BDEVNAME_SIZE];
 540         ssize_t bl = 0;
 541
 542         if (bd)
 543                 bl += sprintf(b + bl, "iBlock device: %s",
 544                                 bdevname(bd, buf));
 545         if (ibd->ibd_flags & IBDF_HAS_UDEV_PATH) {
 546                 bl += sprintf(b + bl, "  UDEV PATH: %s\n",
 547                                 ibd->ibd_udev_path);
 548         } else
 549                 bl += sprintf(b + bl, "\n");
 550
 551         bl += sprintf(b + bl, "        ");
 552         if (bd) {
 553                 bl += sprintf(b + bl, "Major: %d Minor: %d  %s\n",
 554                         ibd->ibd_major, ibd->ibd_minor, (!bd->bd_contains) ?
 555                         "" : (bd->bd_holder == (struct iblock_dev *)ibd) ?
 556                         "CLAIMED: IBLOCK" : "CLAIMED: OS");
 557         } else {
 558                 bl += sprintf(b + bl, "Major: %d Minor: %d\n",
 559                         ibd->ibd_major, ibd->ibd_minor);
 560         }
 561
 562         return bl;
 563 }
 564
 565 static void iblock_bio_destructor(struct bio *bio)
 566 {
 567         struct se_task *task = bio->bi_private;
 568         struct iblock_dev *ib_dev = task->se_dev->dev_ptr;
 569
 570         bio_free(bio, ib_dev->ibd_bio_set);
 571 }
 572
 573 static struct bio *iblock_get_bio(
 574         struct se_task *task,
 575         struct iblock_req *ib_req,
 576         struct iblock_dev *ib_dev,
 577         int *ret,
 578         sector_t lba,
 579         u32 sg_num)
 580 {
 581         struct bio *bio;
 582
 583         bio = bio_alloc_bioset(GFP_NOIO, sg_num, ib_dev->ibd_bio_set);
 584         if (!(bio)) {
 585                 printk(KERN_ERR "Unable to allocate memory for bio\n");
 586                 *ret = PYX_TRANSPORT_OUT_OF_MEMORY_RESOURCES;
 587                 return NULL;
 588         }
 589
 590         DEBUG_IBLOCK("Allocated bio: %p task_sg_num: %u using ibd_bio_set:"
 591                 " %p\n", bio, task->task_sg_num, ib_dev->ibd_bio_set);
 592         DEBUG_IBLOCK("Allocated bio: %p task_size: %u\n", bio, task->task_size);
 593
 594         bio->bi_bdev = ib_dev->ibd_bd;
 595         bio->bi_private = (void *) task;
 596         bio->bi_destructor = iblock_bio_destructor;
 597         bio->bi_end_io = &iblock_bio_done;
 598         bio->bi_sector = lba;
 599         atomic_inc(&ib_req->ib_bio_cnt);
 600
 601         DEBUG_IBLOCK("Set bio->bi_sector: %llu\n", bio->bi_sector);
 602         DEBUG_IBLOCK("Set ib_req->ib_bio_cnt: %d\n",
 603                         atomic_read(&ib_req->ib_bio_cnt));
 604         return bio;
 605 }
 606
 607 static int iblock_map_task_SG(struct se_task *task)
 608 {
 609         struct se_cmd *cmd = task->task_se_cmd;
 610         struct se_device *dev = SE_DEV(cmd);
 611         struct iblock_dev *ib_dev = task->se_dev->dev_ptr;
 612         struct iblock_req *ib_req = IBLOCK_REQ(task);
 613         struct bio *bio = NULL, *hbio = NULL, *tbio = NULL;
 614         struct scatterlist *sg;
 615         int ret = 0;
 616         u32 i, sg_num = task->task_sg_num;
 617         sector_t block_lba;
 618         /*
 619          * Do starting conversion up from non 512-byte blocksize with
 620          * struct se_task SCSI blocksize into Linux/Block 512 units for BIO.
 621          */
 622         if (DEV_ATTRIB(dev)->block_size == 4096)
 623                 block_lba = (task->task_lba << 3);
 624         else if (DEV_ATTRIB(dev)->block_size == 2048)
 625                 block_lba = (task->task_lba << 2);
 626         else if (DEV_ATTRIB(dev)->block_size == 1024)
 627                 block_lba = (task->task_lba << 1);
 628         else if (DEV_ATTRIB(dev)->block_size == 512)
 629                 block_lba = task->task_lba;
 630         else {
 631                 printk(KERN_ERR "Unsupported SCSI -> BLOCK LBA conversion:"
 632                                 " %u\n", DEV_ATTRIB(dev)->block_size);
 633                 return PYX_TRANSPORT_LU_COMM_FAILURE;
 634         }
 635
 636         bio = iblock_get_bio(task, ib_req, ib_dev, &ret, block_lba, sg_num);
 637         if (!(bio))
 638                 return ret;
 639
 640         ib_req->ib_bio = bio;
 641         hbio = tbio = bio;
 642         /*
 643          * Use fs/bio.c:bio_add_pages() to setup the bio_vec maplist
 644          * from TCM struct se_mem -> task->task_sg -> struct scatterlist memory.
 645          */
 646         for_each_sg(task->task_sg, sg, task->task_sg_num, i) {
 647                 DEBUG_IBLOCK("task: %p bio: %p Calling bio_add_page(): page:"
 648                         " %p len: %u offset: %u\n", task, bio, sg_page(sg),
 649                                 sg->length, sg->offset);
 650 again:
 651                 ret = bio_add_page(bio, sg_page(sg), sg->length, sg->offset);
 652                 if (ret != sg->length) {
 653
 654                         DEBUG_IBLOCK("*** Set bio->bi_sector: %llu\n",
 655                                         bio->bi_sector);
 656                         DEBUG_IBLOCK("** task->task_size: %u\n",
 657                                         task->task_size);
 658                         DEBUG_IBLOCK("*** bio->bi_max_vecs: %u\n",
 659                                         bio->bi_max_vecs);
 660                         DEBUG_IBLOCK("*** bio->bi_vcnt: %u\n",
 661                                         bio->bi_vcnt);
 662
 663                         bio = iblock_get_bio(task, ib_req, ib_dev, &ret,
 664                                                 block_lba, sg_num);
 665                         if (!(bio))
 666                                 goto fail;
 667
 668                         tbio = tbio->bi_next = bio;
 669                         DEBUG_IBLOCK("-----------------> Added +1 bio: %p to"
 670                                 " list, Going to again\n", bio);
 671                         goto again;
 672                 }
 673                 /* Always in 512 byte units for Linux/Block */
 674                 block_lba += sg->length >> IBLOCK_LBA_SHIFT;
 675                 sg_num--;
 676                 DEBUG_IBLOCK("task: %p bio-add_page() passed!, decremented"
 677                         " sg_num to %u\n", task, sg_num);
 678                 DEBUG_IBLOCK("task: %p bio_add_page() passed!, increased lba"
 679                                 " to %llu\n", task, block_lba);
 680                 DEBUG_IBLOCK("task: %p bio_add_page() passed!, bio->bi_vcnt:"
 681                                 " %u\n", task, bio->bi_vcnt);
 682         }
 683
 684         return 0;
 685 fail:
 686         while (hbio) {
 687                 bio = hbio;
 688                 hbio = hbio->bi_next;
 689                 bio->bi_next = NULL;
 690                 bio_put(bio);
 691         }
 692         return ret;
 693 }
 694
 695 static unsigned char *iblock_get_cdb(struct se_task *task)
 696 {
 697         return IBLOCK_REQ(task)->ib_scsi_cdb;
 698 }
 699
 700 static u32 iblock_get_device_rev(struct se_device *dev)
 701 {
 702         return SCSI_SPC_2; /* Returns SPC-3 in Initiator Data */
 703 }
 704
 705 static u32 iblock_get_device_type(struct se_device *dev)
 706 {
 707         return TYPE_DISK;
 708 }
 709
 710 static sector_t iblock_get_blocks(struct se_device *dev)
 711 {
 712         struct iblock_dev *ibd = dev->dev_ptr;
 713         struct block_device *bd = ibd->ibd_bd;
 714         struct request_queue *q = bdev_get_queue(bd);
 715
 716         return iblock_emulate_read_cap_with_block_size(dev, bd, q);
 717 }
 718
 719 static void iblock_bio_done(struct bio *bio, int err)
 720 {
 721         struct se_task *task = bio->bi_private;
 722         struct iblock_req *ibr = IBLOCK_REQ(task);
 723         /*
 724          * Set -EIO if !BIO_UPTODATE and the passed is still err=0
 725          */
 726         if (!(test_bit(BIO_UPTODATE, &bio->bi_flags)) && !(err))
 727                 err = -EIO;
 728
 729         if (err != 0) {
 730                 printk(KERN_ERR "test_bit(BIO_UPTODATE) failed for bio: %p,"
 731                         " err: %d\n", bio, err);
 732                 /*
 733                  * Bump the ib_bio_err_cnt and release bio.
 734                  */
 735                 atomic_inc(&ibr->ib_bio_err_cnt);
 736                 smp_mb__after_atomic_inc();
 737                 bio_put(bio);
 738                 /*
 739                  * Wait to complete the task until the last bio as completed.
 740                  */
 741                 if (!(atomic_dec_and_test(&ibr->ib_bio_cnt)))
 742                         return;
 743
 744                 ibr->ib_bio = NULL;
 745                 transport_complete_task(task, 0);
 746                 return;
 747         }
 748         DEBUG_IBLOCK("done[%p] bio: %p task_lba: %llu bio_lba: %llu err=%d\n",
 749                 task, bio, task->task_lba, bio->bi_sector, err);
 750         /*
 751          * bio_put() will call iblock_bio_destructor() to release the bio back
 752          * to ibr->ib_bio_set.
 753          */
 754         bio_put(bio);
 755         /*
 756          * Wait to complete the task until the last bio as completed.
 757          */
 758         if (!(atomic_dec_and_test(&ibr->ib_bio_cnt)))
 759                 return;
 760         /*
 761          * Return GOOD status for task if zero ib_bio_err_cnt exists.
 762          */
 763         ibr->ib_bio = NULL;
 764         transport_complete_task(task, (!atomic_read(&ibr->ib_bio_err_cnt)));
 765 }
 766
 767 static struct se_subsystem_api iblock_template = {
 768         .name                   = "iblock",
 769         .owner                  = THIS_MODULE,
 770         .transport_type         = TRANSPORT_PLUGIN_VHBA_PDEV,
 771         .map_task_SG            = iblock_map_task_SG,
 772         .attach_hba             = iblock_attach_hba,
 773         .detach_hba             = iblock_detach_hba,
 774         .allocate_virtdevice    = iblock_allocate_virtdevice,
 775         .create_virtdevice      = iblock_create_virtdevice,
 776         .free_device            = iblock_free_device,
 777         .dpo_emulated           = iblock_emulated_dpo,
 778         .fua_write_emulated     = iblock_emulated_fua_write,
 779         .fua_read_emulated      = iblock_emulated_fua_read,
 780         .write_cache_emulated   = iblock_emulated_write_cache,
 781         .alloc_task             = iblock_alloc_task,
 782         .do_task                = iblock_do_task,
 783         .do_discard             = iblock_do_discard,
 784         .do_sync_cache          = iblock_emulate_sync_cache,
 785         .free_task              = iblock_free_task,
 786         .check_configfs_dev_params = iblock_check_configfs_dev_params,
 787         .set_configfs_dev_params = iblock_set_configfs_dev_params,
 788         .show_configfs_dev_params = iblock_show_configfs_dev_params,
 789         .get_cdb                = iblock_get_cdb,
 790         .get_device_rev         = iblock_get_device_rev,
 791         .get_device_type        = iblock_get_device_type,
 792         .get_blocks             = iblock_get_blocks,
 793 };
 794
 795 static int __init iblock_module_init(void)
 796 {
 797         return transport_subsystem_register(&iblock_template);
 798 }
 799
 800 static void iblock_module_exit(void)
 801 {
 802         transport_subsystem_release(&iblock_template);
 803 }
 804
 805 MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin");
 806 MODULE_AUTHOR("nab@Linux-iSCSI.org");
 807 MODULE_LICENSE("GPL");
 808
 809 module_init(iblock_module_init);
 810 module_exit(iblock_module_exit);