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  * (c) Copyright 2003-2013 Datera, Inc.
   8  *
   9  * Nicholas A. Bellinger <nab@kernel.org>
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  24  *
  25  ******************************************************************************/
  26
  27 #include <linux/string.h>
  28 #include <linux/parser.h>
  29 #include <linux/timer.h>
  30 #include <linux/fs.h>
  31 #include <linux/blkdev.h>
  32 #include <linux/slab.h>
  33 #include <linux/spinlock.h>
  34 #include <linux/bio.h>
  35 #include <linux/genhd.h>
  36 #include <linux/file.h>
  37 #include <linux/module.h>
  38 #include <scsi/scsi.h>
  39 #include <scsi/scsi_host.h>
  40 #include <asm/unaligned.h>
  41
  42 #include <target/target_core_base.h>
  43 #include <target/target_core_backend.h>
  44
  45 #include "target_core_iblock.h"
  46
  47 #define IBLOCK_MAX_BIO_PER_TASK  32     /* max # of bios to submit at a time */
  48 #define IBLOCK_BIO_POOL_SIZE    128
  49
  50 static inline struct iblock_dev *IBLOCK_DEV(struct se_device *dev)
  51 {
  52         return container_of(dev, struct iblock_dev, dev);
  53 }
  54
  55
  56 static int iblock_attach_hba(struct se_hba *hba, u32 host_id)
  57 {
  58         pr_debug("CORE_HBA[%d] - TCM iBlock HBA Driver %s on"
  59                 " Generic Target Core Stack %s\n", hba->hba_id,
  60                 IBLOCK_VERSION, TARGET_CORE_MOD_VERSION);
  61         return 0;
  62 }
  63
  64 static void iblock_detach_hba(struct se_hba *hba)
  65 {
  66 }
  67
  68 static struct se_device *iblock_alloc_device(struct se_hba *hba, const char *name)
  69 {
  70         struct iblock_dev *ib_dev = NULL;
  71
  72         ib_dev = kzalloc(sizeof(struct iblock_dev), GFP_KERNEL);
  73         if (!ib_dev) {
  74                 pr_err("Unable to allocate struct iblock_dev\n");
  75                 return NULL;
  76         }
  77
  78         pr_debug( "IBLOCK: Allocated ib_dev for %s\n", name);
  79
  80         return &ib_dev->dev;
  81 }
  82
  83 static int iblock_configure_device(struct se_device *dev)
  84 {
  85         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
  86         struct request_queue *q;
  87         struct block_device *bd = NULL;
  88         struct blk_integrity *bi;
  89         fmode_t mode;
  90         int ret = -ENOMEM;
  91
  92         if (!(ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)) {
  93                 pr_err("Missing udev_path= parameters for IBLOCK\n");
  94                 return -EINVAL;
  95         }
  96
  97         ib_dev->ibd_bio_set = bioset_create(IBLOCK_BIO_POOL_SIZE, 0);
  98         if (!ib_dev->ibd_bio_set) {
  99                 pr_err("IBLOCK: Unable to create bioset\n");
 100                 goto out;
 101         }
 102
 103         pr_debug( "IBLOCK: Claiming struct block_device: %s\n",
 104                         ib_dev->ibd_udev_path);
 105
 106         mode = FMODE_READ|FMODE_EXCL;
 107         if (!ib_dev->ibd_readonly)
 108                 mode |= FMODE_WRITE;
 109
 110         bd = blkdev_get_by_path(ib_dev->ibd_udev_path, mode, ib_dev);
 111         if (IS_ERR(bd)) {
 112                 ret = PTR_ERR(bd);
 113                 goto out_free_bioset;
 114         }
 115         ib_dev->ibd_bd = bd;
 116
 117         q = bdev_get_queue(bd);
 118
 119         dev->dev_attrib.hw_block_size = bdev_logical_block_size(bd);
 120         dev->dev_attrib.hw_max_sectors = queue_max_hw_sectors(q);
 121         dev->dev_attrib.hw_queue_depth = q->nr_requests;
 122
 123         /*
 124          * Check if the underlying struct block_device request_queue supports
 125          * the QUEUE_FLAG_DISCARD bit for UNMAP/WRITE_SAME in SCSI + TRIM
 126          * in ATA and we need to set TPE=1
 127          */
 128         if (blk_queue_discard(q)) {
 129                 dev->dev_attrib.max_unmap_lba_count =
 130                                 q->limits.max_discard_sectors;
 131
 132                 /*
 133                  * Currently hardcoded to 1 in Linux/SCSI code..
 134                  */
 135                 dev->dev_attrib.max_unmap_block_desc_count = 1;
 136                 dev->dev_attrib.unmap_granularity =
 137                                 q->limits.discard_granularity >> 9;
 138                 dev->dev_attrib.unmap_granularity_alignment =
 139                                 q->limits.discard_alignment;
 140
 141                 pr_debug("IBLOCK: BLOCK Discard support available,"
 142                                 " disabled by default\n");
 143         }
 144         /*
 145          * Enable write same emulation for IBLOCK and use 0xFFFF as
 146          * the smaller WRITE_SAME(10) only has a two-byte block count.
 147          */
 148         dev->dev_attrib.max_write_same_len = 0xFFFF;
 149
 150         if (blk_queue_nonrot(q))
 151                 dev->dev_attrib.is_nonrot = 1;
 152
 153         bi = bdev_get_integrity(bd);
 154         if (bi) {
 155                 struct bio_set *bs = ib_dev->ibd_bio_set;
 156
 157                 if (!strcmp(bi->name, "T10-DIF-TYPE3-IP") ||
 158                     !strcmp(bi->name, "T10-DIF-TYPE1-IP")) {
 159                         pr_err("IBLOCK export of blk_integrity: %s not"
 160                                " supported\n", bi->name);
 161                         ret = -ENOSYS;
 162                         goto out_blkdev_put;
 163                 }
 164
 165                 if (!strcmp(bi->name, "T10-DIF-TYPE3-CRC")) {
 166                         dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE3_PROT;
 167                 } else if (!strcmp(bi->name, "T10-DIF-TYPE1-CRC")) {
 168                         dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE1_PROT;
 169                 }
 170
 171                 if (dev->dev_attrib.pi_prot_type) {
 172                         if (bioset_integrity_create(bs, IBLOCK_BIO_POOL_SIZE) < 0) {
 173                                 pr_err("Unable to allocate bioset for PI\n");
 174                                 ret = -ENOMEM;
 175                                 goto out_blkdev_put;
 176                         }
 177                         pr_debug("IBLOCK setup BIP bs->bio_integrity_pool: %p\n",
 178                                  bs->bio_integrity_pool);
 179                 }
 180                 dev->dev_attrib.hw_pi_prot_type = dev->dev_attrib.pi_prot_type;
 181         }
 182
 183         return 0;
 184
 185 out_blkdev_put:
 186         blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
 187 out_free_bioset:
 188         bioset_free(ib_dev->ibd_bio_set);
 189         ib_dev->ibd_bio_set = NULL;
 190 out:
 191         return ret;
 192 }
 193
 194 static void iblock_free_device(struct se_device *dev)
 195 {
 196         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 197
 198         if (ib_dev->ibd_bd != NULL)
 199                 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
 200         if (ib_dev->ibd_bio_set != NULL)
 201                 bioset_free(ib_dev->ibd_bio_set);
 202
 203         kfree(ib_dev);
 204 }
 205
 206 static unsigned long long iblock_emulate_read_cap_with_block_size(
 207         struct se_device *dev,
 208         struct block_device *bd,
 209         struct request_queue *q)
 210 {
 211         unsigned long long blocks_long = (div_u64(i_size_read(bd->bd_inode),
 212                                         bdev_logical_block_size(bd)) - 1);
 213         u32 block_size = bdev_logical_block_size(bd);
 214
 215         if (block_size == dev->dev_attrib.block_size)
 216                 return blocks_long;
 217
 218         switch (block_size) {
 219         case 4096:
 220                 switch (dev->dev_attrib.block_size) {
 221                 case 2048:
 222                         blocks_long <<= 1;
 223                         break;
 224                 case 1024:
 225                         blocks_long <<= 2;
 226                         break;
 227                 case 512:
 228                         blocks_long <<= 3;
 229                 default:
 230                         break;
 231                 }
 232                 break;
 233         case 2048:
 234                 switch (dev->dev_attrib.block_size) {
 235                 case 4096:
 236                         blocks_long >>= 1;
 237                         break;
 238                 case 1024:
 239                         blocks_long <<= 1;
 240                         break;
 241                 case 512:
 242                         blocks_long <<= 2;
 243                         break;
 244                 default:
 245                         break;
 246                 }
 247                 break;
 248         case 1024:
 249                 switch (dev->dev_attrib.block_size) {
 250                 case 4096:
 251                         blocks_long >>= 2;
 252                         break;
 253                 case 2048:
 254                         blocks_long >>= 1;
 255                         break;
 256                 case 512:
 257                         blocks_long <<= 1;
 258                         break;
 259                 default:
 260                         break;
 261                 }
 262                 break;
 263         case 512:
 264                 switch (dev->dev_attrib.block_size) {
 265                 case 4096:
 266                         blocks_long >>= 3;
 267                         break;
 268                 case 2048:
 269                         blocks_long >>= 2;
 270                         break;
 271                 case 1024:
 272                         blocks_long >>= 1;
 273                         break;
 274                 default:
 275                         break;
 276                 }
 277                 break;
 278         default:
 279                 break;
 280         }
 281
 282         return blocks_long;
 283 }
 284
 285 static void iblock_complete_cmd(struct se_cmd *cmd)
 286 {
 287         struct iblock_req *ibr = cmd->priv;
 288         u8 status;
 289
 290         if (!atomic_dec_and_test(&ibr->pending))
 291                 return;
 292
 293         if (atomic_read(&ibr->ib_bio_err_cnt))
 294                 status = SAM_STAT_CHECK_CONDITION;
 295         else
 296                 status = SAM_STAT_GOOD;
 297
 298         target_complete_cmd(cmd, status);
 299         kfree(ibr);
 300 }
 301
 302 static void iblock_bio_done(struct bio *bio, int err)
 303 {
 304         struct se_cmd *cmd = bio->bi_private;
 305         struct iblock_req *ibr = cmd->priv;
 306
 307         /*
 308          * Set -EIO if !BIO_UPTODATE and the passed is still err=0
 309          */
 310         if (!test_bit(BIO_UPTODATE, &bio->bi_flags) && !err)
 311                 err = -EIO;
 312
 313         if (err != 0) {
 314                 pr_err("test_bit(BIO_UPTODATE) failed for bio: %p,"
 315                         " err: %d\n", bio, err);
 316                 /*
 317                  * Bump the ib_bio_err_cnt and release bio.
 318                  */
 319                 atomic_inc(&ibr->ib_bio_err_cnt);
 320                 smp_mb__after_atomic();
 321         }
 322
 323         bio_put(bio);
 324
 325         iblock_complete_cmd(cmd);
 326 }
 327
 328 static struct bio *
 329 iblock_get_bio(struct se_cmd *cmd, sector_t lba, u32 sg_num)
 330 {
 331         struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
 332         struct bio *bio;
 333
 334         /*
 335          * Only allocate as many vector entries as the bio code allows us to,
 336          * we'll loop later on until we have handled the whole request.
 337          */
 338         if (sg_num > BIO_MAX_PAGES)
 339                 sg_num = BIO_MAX_PAGES;
 340
 341         bio = bio_alloc_bioset(GFP_NOIO, sg_num, ib_dev->ibd_bio_set);
 342         if (!bio) {
 343                 pr_err("Unable to allocate memory for bio\n");
 344                 return NULL;
 345         }
 346
 347         bio->bi_bdev = ib_dev->ibd_bd;
 348         bio->bi_private = cmd;
 349         bio->bi_end_io = &iblock_bio_done;
 350         bio->bi_iter.bi_sector = lba;
 351
 352         return bio;
 353 }
 354
 355 static void iblock_submit_bios(struct bio_list *list, int rw)
 356 {
 357         struct blk_plug plug;
 358         struct bio *bio;
 359
 360         blk_start_plug(&plug);
 361         while ((bio = bio_list_pop(list)))
 362                 submit_bio(rw, bio);
 363         blk_finish_plug(&plug);
 364 }
 365
 366 static void iblock_end_io_flush(struct bio *bio, int err)
 367 {
 368         struct se_cmd *cmd = bio->bi_private;
 369
 370         if (err)
 371                 pr_err("IBLOCK: cache flush failed: %d\n", err);
 372
 373         if (cmd) {
 374                 if (err)
 375                         target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
 376                 else
 377                         target_complete_cmd(cmd, SAM_STAT_GOOD);
 378         }
 379
 380         bio_put(bio);
 381 }
 382
 383 /*
 384  * Implement SYCHRONIZE CACHE.  Note that we can't handle lba ranges and must
 385  * always flush the whole cache.
 386  */
 387 static sense_reason_t
 388 iblock_execute_sync_cache(struct se_cmd *cmd)
 389 {
 390         struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
 391         int immed = (cmd->t_task_cdb[1] & 0x2);
 392         struct bio *bio;
 393
 394         /*
 395          * If the Immediate bit is set, queue up the GOOD response
 396          * for this SYNCHRONIZE_CACHE op.
 397          */
 398         if (immed)
 399                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 400
 401         bio = bio_alloc(GFP_KERNEL, 0);
 402         bio->bi_end_io = iblock_end_io_flush;
 403         bio->bi_bdev = ib_dev->ibd_bd;
 404         if (!immed)
 405                 bio->bi_private = cmd;
 406         submit_bio(WRITE_FLUSH, bio);
 407         return 0;
 408 }
 409
 410 static sense_reason_t
 411 iblock_do_unmap(struct se_cmd *cmd, void *priv,
 412                 sector_t lba, sector_t nolb)
 413 {
 414         struct block_device *bdev = priv;
 415         int ret;
 416
 417         ret = blkdev_issue_discard(bdev, lba, nolb, GFP_KERNEL, 0);
 418         if (ret < 0) {
 419                 pr_err("blkdev_issue_discard() failed: %d\n", ret);
 420                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 421         }
 422
 423         return 0;
 424 }
 425
 426 static sense_reason_t
 427 iblock_execute_unmap(struct se_cmd *cmd)
 428 {
 429         struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
 430
 431         return sbc_execute_unmap(cmd, iblock_do_unmap, bdev);
 432 }
 433
 434 static sense_reason_t
 435 iblock_execute_write_same_unmap(struct se_cmd *cmd)
 436 {
 437         struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
 438         sector_t lba = cmd->t_task_lba;
 439         sector_t nolb = sbc_get_write_same_sectors(cmd);
 440         sense_reason_t ret;
 441
 442         ret = iblock_do_unmap(cmd, bdev, lba, nolb);
 443         if (ret)
 444                 return ret;
 445
 446         target_complete_cmd(cmd, GOOD);
 447         return 0;
 448 }
 449
 450 static sense_reason_t
 451 iblock_execute_write_same(struct se_cmd *cmd)
 452 {
 453         struct iblock_req *ibr;
 454         struct scatterlist *sg;
 455         struct bio *bio;
 456         struct bio_list list;
 457         sector_t block_lba = cmd->t_task_lba;
 458         sector_t sectors = sbc_get_write_same_sectors(cmd);
 459
 460         if (cmd->prot_op) {
 461                 pr_err("WRITE_SAME: Protection information with IBLOCK"
 462                        " backends not supported\n");
 463                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 464         }
 465         sg = &cmd->t_data_sg[0];
 466
 467         if (cmd->t_data_nents > 1 ||
 468             sg->length != cmd->se_dev->dev_attrib.block_size) {
 469                 pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
 470                         " block_size: %u\n", cmd->t_data_nents, sg->length,
 471                         cmd->se_dev->dev_attrib.block_size);
 472                 return TCM_INVALID_CDB_FIELD;
 473         }
 474
 475         ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
 476         if (!ibr)
 477                 goto fail;
 478         cmd->priv = ibr;
 479
 480         bio = iblock_get_bio(cmd, block_lba, 1);
 481         if (!bio)
 482                 goto fail_free_ibr;
 483
 484         bio_list_init(&list);
 485         bio_list_add(&list, bio);
 486
 487         atomic_set(&ibr->pending, 1);
 488
 489         while (sectors) {
 490                 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
 491                                 != sg->length) {
 492
 493                         bio = iblock_get_bio(cmd, block_lba, 1);
 494                         if (!bio)
 495                                 goto fail_put_bios;
 496
 497                         atomic_inc(&ibr->pending);
 498                         bio_list_add(&list, bio);
 499                 }
 500
 501                 /* Always in 512 byte units for Linux/Block */
 502                 block_lba += sg->length >> IBLOCK_LBA_SHIFT;
 503                 sectors -= 1;
 504         }
 505
 506         iblock_submit_bios(&list, WRITE);
 507         return 0;
 508
 509 fail_put_bios:
 510         while ((bio = bio_list_pop(&list)))
 511                 bio_put(bio);
 512 fail_free_ibr:
 513         kfree(ibr);
 514 fail:
 515         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 516 }
 517
 518 enum {
 519         Opt_udev_path, Opt_readonly, Opt_force, Opt_err
 520 };
 521
 522 static match_table_t tokens = {
 523         {Opt_udev_path, "udev_path=%s"},
 524         {Opt_readonly, "readonly=%d"},
 525         {Opt_force, "force=%d"},
 526         {Opt_err, NULL}
 527 };
 528
 529 static ssize_t iblock_set_configfs_dev_params(struct se_device *dev,
 530                 const char *page, ssize_t count)
 531 {
 532         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 533         char *orig, *ptr, *arg_p, *opts;
 534         substring_t args[MAX_OPT_ARGS];
 535         int ret = 0, token;
 536         unsigned long tmp_readonly;
 537
 538         opts = kstrdup(page, GFP_KERNEL);
 539         if (!opts)
 540                 return -ENOMEM;
 541
 542         orig = opts;
 543
 544         while ((ptr = strsep(&opts, ",\n")) != NULL) {
 545                 if (!*ptr)
 546                         continue;
 547
 548                 token = match_token(ptr, tokens, args);
 549                 switch (token) {
 550                 case Opt_udev_path:
 551                         if (ib_dev->ibd_bd) {
 552                                 pr_err("Unable to set udev_path= while"
 553                                         " ib_dev->ibd_bd exists\n");
 554                                 ret = -EEXIST;
 555                                 goto out;
 556                         }
 557                         if (match_strlcpy(ib_dev->ibd_udev_path, &args[0],
 558                                 SE_UDEV_PATH_LEN) == 0) {
 559                                 ret = -EINVAL;
 560                                 break;
 561                         }
 562                         pr_debug("IBLOCK: Referencing UDEV path: %s\n",
 563                                         ib_dev->ibd_udev_path);
 564                         ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH;
 565                         break;
 566                 case Opt_readonly:
 567                         arg_p = match_strdup(&args[0]);
 568                         if (!arg_p) {
 569                                 ret = -ENOMEM;
 570                                 break;
 571                         }
 572                         ret = kstrtoul(arg_p, 0, &tmp_readonly);
 573                         kfree(arg_p);
 574                         if (ret < 0) {
 575                                 pr_err("kstrtoul() failed for"
 576                                                 " readonly=\n");
 577                                 goto out;
 578                         }
 579                         ib_dev->ibd_readonly = tmp_readonly;
 580                         pr_debug("IBLOCK: readonly: %d\n", ib_dev->ibd_readonly);
 581                         break;
 582                 case Opt_force:
 583                         break;
 584                 default:
 585                         break;
 586                 }
 587         }
 588
 589 out:
 590         kfree(orig);
 591         return (!ret) ? count : ret;
 592 }
 593
 594 static ssize_t iblock_show_configfs_dev_params(struct se_device *dev, char *b)
 595 {
 596         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 597         struct block_device *bd = ib_dev->ibd_bd;
 598         char buf[BDEVNAME_SIZE];
 599         ssize_t bl = 0;
 600
 601         if (bd)
 602                 bl += sprintf(b + bl, "iBlock device: %s",
 603                                 bdevname(bd, buf));
 604         if (ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)
 605                 bl += sprintf(b + bl, "  UDEV PATH: %s",
 606                                 ib_dev->ibd_udev_path);
 607         bl += sprintf(b + bl, "  readonly: %d\n", ib_dev->ibd_readonly);
 608
 609         bl += sprintf(b + bl, "        ");
 610         if (bd) {
 611                 bl += sprintf(b + bl, "Major: %d Minor: %d  %s\n",
 612                         MAJOR(bd->bd_dev), MINOR(bd->bd_dev), (!bd->bd_contains) ?
 613                         "" : (bd->bd_holder == ib_dev) ?
 614                         "CLAIMED: IBLOCK" : "CLAIMED: OS");
 615         } else {
 616                 bl += sprintf(b + bl, "Major: 0 Minor: 0\n");
 617         }
 618
 619         return bl;
 620 }
 621
 622 static int
 623 iblock_alloc_bip(struct se_cmd *cmd, struct bio *bio)
 624 {
 625         struct se_device *dev = cmd->se_dev;
 626         struct blk_integrity *bi;
 627         struct bio_integrity_payload *bip;
 628         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 629         struct scatterlist *sg;
 630         int i, rc;
 631
 632         bi = bdev_get_integrity(ib_dev->ibd_bd);
 633         if (!bi) {
 634                 pr_err("Unable to locate bio_integrity\n");
 635                 return -ENODEV;
 636         }
 637
 638         bip = bio_integrity_alloc(bio, GFP_NOIO, cmd->t_prot_nents);
 639         if (!bip) {
 640                 pr_err("Unable to allocate bio_integrity_payload\n");
 641                 return -ENOMEM;
 642         }
 643
 644         bip->bip_iter.bi_size = (cmd->data_length / dev->dev_attrib.block_size) *
 645                          dev->prot_length;
 646         bip->bip_iter.bi_sector = bio->bi_iter.bi_sector;
 647
 648         pr_debug("IBLOCK BIP Size: %u Sector: %llu\n", bip->bip_iter.bi_size,
 649                  (unsigned long long)bip->bip_iter.bi_sector);
 650
 651         for_each_sg(cmd->t_prot_sg, sg, cmd->t_prot_nents, i) {
 652
 653                 rc = bio_integrity_add_page(bio, sg_page(sg), sg->length,
 654                                             sg->offset);
 655                 if (rc != sg->length) {
 656                         pr_err("bio_integrity_add_page() failed; %d\n", rc);
 657                         return -ENOMEM;
 658                 }
 659
 660                 pr_debug("Added bio integrity page: %p length: %d offset; %d\n",
 661                          sg_page(sg), sg->length, sg->offset);
 662         }
 663
 664         return 0;
 665 }
 666
 667 static sense_reason_t
 668 iblock_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 669                   enum dma_data_direction data_direction)
 670 {
 671         struct se_device *dev = cmd->se_dev;
 672         struct iblock_req *ibr;
 673         struct bio *bio, *bio_start;
 674         struct bio_list list;
 675         struct scatterlist *sg;
 676         u32 sg_num = sgl_nents;
 677         sector_t block_lba;
 678         unsigned bio_cnt;
 679         int rw = 0;
 680         int i;
 681
 682         if (data_direction == DMA_TO_DEVICE) {
 683                 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 684                 struct request_queue *q = bdev_get_queue(ib_dev->ibd_bd);
 685                 /*
 686                  * Force writethrough using WRITE_FUA if a volatile write cache
 687                  * is not enabled, or if initiator set the Force Unit Access bit.
 688                  */
 689                 if (q->flush_flags & REQ_FUA) {
 690                         if (cmd->se_cmd_flags & SCF_FUA)
 691                                 rw = WRITE_FUA;
 692                         else if (!(q->flush_flags & REQ_FLUSH))
 693                                 rw = WRITE_FUA;
 694                         else
 695                                 rw = WRITE;
 696                 } else {
 697                         rw = WRITE;
 698                 }
 699         } else {
 700                 rw = READ;
 701         }
 702
 703         /*
 704          * Convert the blocksize advertised to the initiator to the 512 byte
 705          * units unconditionally used by the Linux block layer.
 706          */
 707         if (dev->dev_attrib.block_size == 4096)
 708                 block_lba = (cmd->t_task_lba << 3);
 709         else if (dev->dev_attrib.block_size == 2048)
 710                 block_lba = (cmd->t_task_lba << 2);
 711         else if (dev->dev_attrib.block_size == 1024)
 712                 block_lba = (cmd->t_task_lba << 1);
 713         else if (dev->dev_attrib.block_size == 512)
 714                 block_lba = cmd->t_task_lba;
 715         else {
 716                 pr_err("Unsupported SCSI -> BLOCK LBA conversion:"
 717                                 " %u\n", dev->dev_attrib.block_size);
 718                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 719         }
 720
 721         ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
 722         if (!ibr)
 723                 goto fail;
 724         cmd->priv = ibr;
 725
 726         if (!sgl_nents) {
 727                 atomic_set(&ibr->pending, 1);
 728                 iblock_complete_cmd(cmd);
 729                 return 0;
 730         }
 731
 732         bio = iblock_get_bio(cmd, block_lba, sgl_nents);
 733         if (!bio)
 734                 goto fail_free_ibr;
 735
 736         bio_start = bio;
 737         bio_list_init(&list);
 738         bio_list_add(&list, bio);
 739
 740         atomic_set(&ibr->pending, 2);
 741         bio_cnt = 1;
 742
 743         for_each_sg(sgl, sg, sgl_nents, i) {
 744                 /*
 745                  * XXX: if the length the device accepts is shorter than the
 746                  *      length of the S/G list entry this will cause and
 747                  *      endless loop.  Better hope no driver uses huge pages.
 748                  */
 749                 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
 750                                 != sg->length) {
 751                         if (bio_cnt >= IBLOCK_MAX_BIO_PER_TASK) {
 752                                 iblock_submit_bios(&list, rw);
 753                                 bio_cnt = 0;
 754                         }
 755
 756                         bio = iblock_get_bio(cmd, block_lba, sg_num);
 757                         if (!bio)
 758                                 goto fail_put_bios;
 759
 760                         atomic_inc(&ibr->pending);
 761                         bio_list_add(&list, bio);
 762                         bio_cnt++;
 763                 }
 764
 765                 /* Always in 512 byte units for Linux/Block */
 766                 block_lba += sg->length >> IBLOCK_LBA_SHIFT;
 767                 sg_num--;
 768         }
 769
 770         if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
 771                 int rc = iblock_alloc_bip(cmd, bio_start);
 772                 if (rc)
 773                         goto fail_put_bios;
 774         }
 775
 776         iblock_submit_bios(&list, rw);
 777         iblock_complete_cmd(cmd);
 778         return 0;
 779
 780 fail_put_bios:
 781         while ((bio = bio_list_pop(&list)))
 782                 bio_put(bio);
 783 fail_free_ibr:
 784         kfree(ibr);
 785 fail:
 786         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 787 }
 788
 789 static sector_t iblock_get_blocks(struct se_device *dev)
 790 {
 791         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 792         struct block_device *bd = ib_dev->ibd_bd;
 793         struct request_queue *q = bdev_get_queue(bd);
 794
 795         return iblock_emulate_read_cap_with_block_size(dev, bd, q);
 796 }
 797
 798 static sector_t iblock_get_alignment_offset_lbas(struct se_device *dev)
 799 {
 800         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 801         struct block_device *bd = ib_dev->ibd_bd;
 802         int ret;
 803
 804         ret = bdev_alignment_offset(bd);
 805         if (ret == -1)
 806                 return 0;
 807
 808         /* convert offset-bytes to offset-lbas */
 809         return ret / bdev_logical_block_size(bd);
 810 }
 811
 812 static unsigned int iblock_get_lbppbe(struct se_device *dev)
 813 {
 814         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 815         struct block_device *bd = ib_dev->ibd_bd;
 816         int logs_per_phys = bdev_physical_block_size(bd) / bdev_logical_block_size(bd);
 817
 818         return ilog2(logs_per_phys);
 819 }
 820
 821 static unsigned int iblock_get_io_min(struct se_device *dev)
 822 {
 823         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 824         struct block_device *bd = ib_dev->ibd_bd;
 825
 826         return bdev_io_min(bd);
 827 }
 828
 829 static unsigned int iblock_get_io_opt(struct se_device *dev)
 830 {
 831         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 832         struct block_device *bd = ib_dev->ibd_bd;
 833
 834         return bdev_io_opt(bd);
 835 }
 836
 837 static struct sbc_ops iblock_sbc_ops = {
 838         .execute_rw             = iblock_execute_rw,
 839         .execute_sync_cache     = iblock_execute_sync_cache,
 840         .execute_write_same     = iblock_execute_write_same,
 841         .execute_write_same_unmap = iblock_execute_write_same_unmap,
 842         .execute_unmap          = iblock_execute_unmap,
 843 };
 844
 845 static sense_reason_t
 846 iblock_parse_cdb(struct se_cmd *cmd)
 847 {
 848         return sbc_parse_cdb(cmd, &iblock_sbc_ops);
 849 }
 850
 851 static bool iblock_get_write_cache(struct se_device *dev)
 852 {
 853         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 854         struct block_device *bd = ib_dev->ibd_bd;
 855         struct request_queue *q = bdev_get_queue(bd);
 856
 857         return q->flush_flags & REQ_FLUSH;
 858 }
 859
 860 static const struct target_backend_ops iblock_ops = {
 861         .name                   = "iblock",
 862         .inquiry_prod           = "IBLOCK",
 863         .inquiry_rev            = IBLOCK_VERSION,
 864         .owner                  = THIS_MODULE,
 865         .attach_hba             = iblock_attach_hba,
 866         .detach_hba             = iblock_detach_hba,
 867         .alloc_device           = iblock_alloc_device,
 868         .configure_device       = iblock_configure_device,
 869         .free_device            = iblock_free_device,
 870         .parse_cdb              = iblock_parse_cdb,
 871         .set_configfs_dev_params = iblock_set_configfs_dev_params,
 872         .show_configfs_dev_params = iblock_show_configfs_dev_params,
 873         .get_device_type        = sbc_get_device_type,
 874         .get_blocks             = iblock_get_blocks,
 875         .get_alignment_offset_lbas = iblock_get_alignment_offset_lbas,
 876         .get_lbppbe             = iblock_get_lbppbe,
 877         .get_io_min             = iblock_get_io_min,
 878         .get_io_opt             = iblock_get_io_opt,
 879         .get_write_cache        = iblock_get_write_cache,
 880         .tb_dev_attrib_attrs    = sbc_attrib_attrs,
 881 };
 882
 883 static int __init iblock_module_init(void)
 884 {
 885         return transport_backend_register(&iblock_ops);
 886 }
 887
 888 static void __exit iblock_module_exit(void)
 889 {
 890         target_backend_unregister(&iblock_ops);
 891 }
 892
 893 MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin");
 894 MODULE_AUTHOR("nab@Linux-iSCSI.org");
 895 MODULE_LICENSE("GPL");
 896
 897 module_init(iblock_module_init);
 898 module_exit(iblock_module_exit);