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 #include <target/target_core_backend_configfs.h>
  45
  46 #include "target_core_iblock.h"
  47
  48 #define IBLOCK_MAX_BIO_PER_TASK  32     /* max # of bios to submit at a time */
  49 #define IBLOCK_BIO_POOL_SIZE    128
  50
  51 static inline struct iblock_dev *IBLOCK_DEV(struct se_device *dev)
  52 {
  53         return container_of(dev, struct iblock_dev, dev);
  54 }
  55
  56
  57 static int iblock_attach_hba(struct se_hba *hba, u32 host_id)
  58 {
  59         pr_debug("CORE_HBA[%d] - TCM iBlock HBA Driver %s on"
  60                 " Generic Target Core Stack %s\n", hba->hba_id,
  61                 IBLOCK_VERSION, TARGET_CORE_MOD_VERSION);
  62         return 0;
  63 }
  64
  65 static void iblock_detach_hba(struct se_hba *hba)
  66 {
  67 }
  68
  69 static struct se_device *iblock_alloc_device(struct se_hba *hba, const char *name)
  70 {
  71         struct iblock_dev *ib_dev = NULL;
  72
  73         ib_dev = kzalloc(sizeof(struct iblock_dev), GFP_KERNEL);
  74         if (!ib_dev) {
  75                 pr_err("Unable to allocate struct iblock_dev\n");
  76                 return NULL;
  77         }
  78
  79         pr_debug( "IBLOCK: Allocated ib_dev for %s\n", name);
  80
  81         return &ib_dev->dev;
  82 }
  83
  84 static int iblock_configure_device(struct se_device *dev)
  85 {
  86         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
  87         struct request_queue *q;
  88         struct block_device *bd = NULL;
  89         struct blk_integrity *bi;
  90         fmode_t mode;
  91         int ret = -ENOMEM;
  92
  93         if (!(ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)) {
  94                 pr_err("Missing udev_path= parameters for IBLOCK\n");
  95                 return -EINVAL;
  96         }
  97
  98         ib_dev->ibd_bio_set = bioset_create(IBLOCK_BIO_POOL_SIZE, 0);
  99         if (!ib_dev->ibd_bio_set) {
 100                 pr_err("IBLOCK: Unable to create bioset\n");
 101                 goto out;
 102         }
 103
 104         pr_debug( "IBLOCK: Claiming struct block_device: %s\n",
 105                         ib_dev->ibd_udev_path);
 106
 107         mode = FMODE_READ|FMODE_EXCL;
 108         if (!ib_dev->ibd_readonly)
 109                 mode |= FMODE_WRITE;
 110
 111         bd = blkdev_get_by_path(ib_dev->ibd_udev_path, mode, ib_dev);
 112         if (IS_ERR(bd)) {
 113                 ret = PTR_ERR(bd);
 114                 goto out_free_bioset;
 115         }
 116         ib_dev->ibd_bd = bd;
 117
 118         q = bdev_get_queue(bd);
 119
 120         dev->dev_attrib.hw_block_size = bdev_logical_block_size(bd);
 121         dev->dev_attrib.hw_max_sectors = queue_max_hw_sectors(q);
 122         dev->dev_attrib.hw_queue_depth = q->nr_requests;
 123
 124         /*
 125          * Check if the underlying struct block_device request_queue supports
 126          * the QUEUE_FLAG_DISCARD bit for UNMAP/WRITE_SAME in SCSI + TRIM
 127          * in ATA and we need to set TPE=1
 128          */
 129         if (blk_queue_discard(q)) {
 130                 dev->dev_attrib.max_unmap_lba_count =
 131                                 q->limits.max_discard_sectors;
 132
 133                 /*
 134                  * Currently hardcoded to 1 in Linux/SCSI code..
 135                  */
 136                 dev->dev_attrib.max_unmap_block_desc_count = 1;
 137                 dev->dev_attrib.unmap_granularity =
 138                                 q->limits.discard_granularity >> 9;
 139                 dev->dev_attrib.unmap_granularity_alignment =
 140                                 q->limits.discard_alignment;
 141
 142                 pr_debug("IBLOCK: BLOCK Discard support available,"
 143                                 " disabled by default\n");
 144         }
 145         /*
 146          * Enable write same emulation for IBLOCK and use 0xFFFF as
 147          * the smaller WRITE_SAME(10) only has a two-byte block count.
 148          */
 149         dev->dev_attrib.max_write_same_len = 0xFFFF;
 150
 151         if (blk_queue_nonrot(q))
 152                 dev->dev_attrib.is_nonrot = 1;
 153
 154         bi = bdev_get_integrity(bd);
 155         if (bi) {
 156                 struct bio_set *bs = ib_dev->ibd_bio_set;
 157
 158                 if (!strcmp(bi->name, "T10-DIF-TYPE3-IP") ||
 159                     !strcmp(bi->name, "T10-DIF-TYPE1-IP")) {
 160                         pr_err("IBLOCK export of blk_integrity: %s not"
 161                                " supported\n", bi->name);
 162                         ret = -ENOSYS;
 163                         goto out_blkdev_put;
 164                 }
 165
 166                 if (!strcmp(bi->name, "T10-DIF-TYPE3-CRC")) {
 167                         dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE3_PROT;
 168                 } else if (!strcmp(bi->name, "T10-DIF-TYPE1-CRC")) {
 169                         dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE1_PROT;
 170                 }
 171
 172                 if (dev->dev_attrib.pi_prot_type) {
 173                         if (bioset_integrity_create(bs, IBLOCK_BIO_POOL_SIZE) < 0) {
 174                                 pr_err("Unable to allocate bioset for PI\n");
 175                                 ret = -ENOMEM;
 176                                 goto out_blkdev_put;
 177                         }
 178                         pr_debug("IBLOCK setup BIP bs->bio_integrity_pool: %p\n",
 179                                  bs->bio_integrity_pool);
 180                 }
 181                 dev->dev_attrib.hw_pi_prot_type = dev->dev_attrib.pi_prot_type;
 182         }
 183
 184         return 0;
 185
 186 out_blkdev_put:
 187         blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
 188 out_free_bioset:
 189         bioset_free(ib_dev->ibd_bio_set);
 190         ib_dev->ibd_bio_set = NULL;
 191 out:
 192         return ret;
 193 }
 194
 195 static void iblock_free_device(struct se_device *dev)
 196 {
 197         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 198
 199         if (ib_dev->ibd_bd != NULL)
 200                 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
 201         if (ib_dev->ibd_bio_set != NULL)
 202                 bioset_free(ib_dev->ibd_bio_set);
 203
 204         kfree(ib_dev);
 205 }
 206
 207 static unsigned long long iblock_emulate_read_cap_with_block_size(
 208         struct se_device *dev,
 209         struct block_device *bd,
 210         struct request_queue *q)
 211 {
 212         unsigned long long blocks_long = (div_u64(i_size_read(bd->bd_inode),
 213                                         bdev_logical_block_size(bd)) - 1);
 214         u32 block_size = bdev_logical_block_size(bd);
 215
 216         if (block_size == dev->dev_attrib.block_size)
 217                 return blocks_long;
 218
 219         switch (block_size) {
 220         case 4096:
 221                 switch (dev->dev_attrib.block_size) {
 222                 case 2048:
 223                         blocks_long <<= 1;
 224                         break;
 225                 case 1024:
 226                         blocks_long <<= 2;
 227                         break;
 228                 case 512:
 229                         blocks_long <<= 3;
 230                 default:
 231                         break;
 232                 }
 233                 break;
 234         case 2048:
 235                 switch (dev->dev_attrib.block_size) {
 236                 case 4096:
 237                         blocks_long >>= 1;
 238                         break;
 239                 case 1024:
 240                         blocks_long <<= 1;
 241                         break;
 242                 case 512:
 243                         blocks_long <<= 2;
 244                         break;
 245                 default:
 246                         break;
 247                 }
 248                 break;
 249         case 1024:
 250                 switch (dev->dev_attrib.block_size) {
 251                 case 4096:
 252                         blocks_long >>= 2;
 253                         break;
 254                 case 2048:
 255                         blocks_long >>= 1;
 256                         break;
 257                 case 512:
 258                         blocks_long <<= 1;
 259                         break;
 260                 default:
 261                         break;
 262                 }
 263                 break;
 264         case 512:
 265                 switch (dev->dev_attrib.block_size) {
 266                 case 4096:
 267                         blocks_long >>= 3;
 268                         break;
 269                 case 2048:
 270                         blocks_long >>= 2;
 271                         break;
 272                 case 1024:
 273                         blocks_long >>= 1;
 274                         break;
 275                 default:
 276                         break;
 277                 }
 278                 break;
 279         default:
 280                 break;
 281         }
 282
 283         return blocks_long;
 284 }
 285
 286 static void iblock_complete_cmd(struct se_cmd *cmd)
 287 {
 288         struct iblock_req *ibr = cmd->priv;
 289         u8 status;
 290
 291         if (!atomic_dec_and_test(&ibr->pending))
 292                 return;
 293
 294         if (atomic_read(&ibr->ib_bio_err_cnt))
 295                 status = SAM_STAT_CHECK_CONDITION;
 296         else
 297                 status = SAM_STAT_GOOD;
 298
 299         target_complete_cmd(cmd, status);
 300         kfree(ibr);
 301 }
 302
 303 static void iblock_bio_done(struct bio *bio, int err)
 304 {
 305         struct se_cmd *cmd = bio->bi_private;
 306         struct iblock_req *ibr = cmd->priv;
 307
 308         /*
 309          * Set -EIO if !BIO_UPTODATE and the passed is still err=0
 310          */
 311         if (!test_bit(BIO_UPTODATE, &bio->bi_flags) && !err)
 312                 err = -EIO;
 313
 314         if (err != 0) {
 315                 pr_err("test_bit(BIO_UPTODATE) failed for bio: %p,"
 316                         " err: %d\n", bio, err);
 317                 /*
 318                  * Bump the ib_bio_err_cnt and release bio.
 319                  */
 320                 atomic_inc(&ibr->ib_bio_err_cnt);
 321                 smp_mb__after_atomic();
 322         }
 323
 324         bio_put(bio);
 325
 326         iblock_complete_cmd(cmd);
 327 }
 328
 329 static struct bio *
 330 iblock_get_bio(struct se_cmd *cmd, sector_t lba, u32 sg_num)
 331 {
 332         struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
 333         struct bio *bio;
 334
 335         /*
 336          * Only allocate as many vector entries as the bio code allows us to,
 337          * we'll loop later on until we have handled the whole request.
 338          */
 339         if (sg_num > BIO_MAX_PAGES)
 340                 sg_num = BIO_MAX_PAGES;
 341
 342         bio = bio_alloc_bioset(GFP_NOIO, sg_num, ib_dev->ibd_bio_set);
 343         if (!bio) {
 344                 pr_err("Unable to allocate memory for bio\n");
 345                 return NULL;
 346         }
 347
 348         bio->bi_bdev = ib_dev->ibd_bd;
 349         bio->bi_private = cmd;
 350         bio->bi_end_io = &iblock_bio_done;
 351         bio->bi_iter.bi_sector = lba;
 352
 353         return bio;
 354 }
 355
 356 static void iblock_submit_bios(struct bio_list *list, int rw)
 357 {
 358         struct blk_plug plug;
 359         struct bio *bio;
 360
 361         blk_start_plug(&plug);
 362         while ((bio = bio_list_pop(list)))
 363                 submit_bio(rw, bio);
 364         blk_finish_plug(&plug);
 365 }
 366
 367 static void iblock_end_io_flush(struct bio *bio, int err)
 368 {
 369         struct se_cmd *cmd = bio->bi_private;
 370
 371         if (err)
 372                 pr_err("IBLOCK: cache flush failed: %d\n", err);
 373
 374         if (cmd) {
 375                 if (err)
 376                         target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
 377                 else
 378                         target_complete_cmd(cmd, SAM_STAT_GOOD);
 379         }
 380
 381         bio_put(bio);
 382 }
 383
 384 /*
 385  * Implement SYCHRONIZE CACHE.  Note that we can't handle lba ranges and must
 386  * always flush the whole cache.
 387  */
 388 static sense_reason_t
 389 iblock_execute_sync_cache(struct se_cmd *cmd)
 390 {
 391         struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
 392         int immed = (cmd->t_task_cdb[1] & 0x2);
 393         struct bio *bio;
 394
 395         /*
 396          * If the Immediate bit is set, queue up the GOOD response
 397          * for this SYNCHRONIZE_CACHE op.
 398          */
 399         if (immed)
 400                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 401
 402         bio = bio_alloc(GFP_KERNEL, 0);
 403         bio->bi_end_io = iblock_end_io_flush;
 404         bio->bi_bdev = ib_dev->ibd_bd;
 405         if (!immed)
 406                 bio->bi_private = cmd;
 407         submit_bio(WRITE_FLUSH, bio);
 408         return 0;
 409 }
 410
 411 static sense_reason_t
 412 iblock_do_unmap(struct se_cmd *cmd, void *priv,
 413                 sector_t lba, sector_t nolb)
 414 {
 415         struct block_device *bdev = priv;
 416         int ret;
 417
 418         ret = blkdev_issue_discard(bdev, lba, nolb, GFP_KERNEL, 0);
 419         if (ret < 0) {
 420                 pr_err("blkdev_issue_discard() failed: %d\n", ret);
 421                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 422         }
 423
 424         return 0;
 425 }
 426
 427 static sense_reason_t
 428 iblock_execute_unmap(struct se_cmd *cmd)
 429 {
 430         struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
 431
 432         return sbc_execute_unmap(cmd, iblock_do_unmap, bdev);
 433 }
 434
 435 static sense_reason_t
 436 iblock_execute_write_same_unmap(struct se_cmd *cmd)
 437 {
 438         struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
 439         sector_t lba = cmd->t_task_lba;
 440         sector_t nolb = sbc_get_write_same_sectors(cmd);
 441         sense_reason_t ret;
 442
 443         ret = iblock_do_unmap(cmd, bdev, lba, nolb);
 444         if (ret)
 445                 return ret;
 446
 447         target_complete_cmd(cmd, GOOD);
 448         return 0;
 449 }
 450
 451 static sense_reason_t
 452 iblock_execute_write_same(struct se_cmd *cmd)
 453 {
 454         struct iblock_req *ibr;
 455         struct scatterlist *sg;
 456         struct bio *bio;
 457         struct bio_list list;
 458         sector_t block_lba = cmd->t_task_lba;
 459         sector_t sectors = sbc_get_write_same_sectors(cmd);
 460
 461         if (cmd->prot_op) {
 462                 pr_err("WRITE_SAME: Protection information with IBLOCK"
 463                        " backends not supported\n");
 464                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 465         }
 466         sg = &cmd->t_data_sg[0];
 467
 468         if (cmd->t_data_nents > 1 ||
 469             sg->length != cmd->se_dev->dev_attrib.block_size) {
 470                 pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
 471                         " block_size: %u\n", cmd->t_data_nents, sg->length,
 472                         cmd->se_dev->dev_attrib.block_size);
 473                 return TCM_INVALID_CDB_FIELD;
 474         }
 475
 476         ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
 477         if (!ibr)
 478                 goto fail;
 479         cmd->priv = ibr;
 480
 481         bio = iblock_get_bio(cmd, block_lba, 1);
 482         if (!bio)
 483                 goto fail_free_ibr;
 484
 485         bio_list_init(&list);
 486         bio_list_add(&list, bio);
 487
 488         atomic_set(&ibr->pending, 1);
 489
 490         while (sectors) {
 491                 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
 492                                 != sg->length) {
 493
 494                         bio = iblock_get_bio(cmd, block_lba, 1);
 495                         if (!bio)
 496                                 goto fail_put_bios;
 497
 498                         atomic_inc(&ibr->pending);
 499                         bio_list_add(&list, bio);
 500                 }
 501
 502                 /* Always in 512 byte units for Linux/Block */
 503                 block_lba += sg->length >> IBLOCK_LBA_SHIFT;
 504                 sectors -= 1;
 505         }
 506
 507         iblock_submit_bios(&list, WRITE);
 508         return 0;
 509
 510 fail_put_bios:
 511         while ((bio = bio_list_pop(&list)))
 512                 bio_put(bio);
 513 fail_free_ibr:
 514         kfree(ibr);
 515 fail:
 516         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 517 }
 518
 519 enum {
 520         Opt_udev_path, Opt_readonly, Opt_force, Opt_err
 521 };
 522
 523 static match_table_t tokens = {
 524         {Opt_udev_path, "udev_path=%s"},
 525         {Opt_readonly, "readonly=%d"},
 526         {Opt_force, "force=%d"},
 527         {Opt_err, NULL}
 528 };
 529
 530 static ssize_t iblock_set_configfs_dev_params(struct se_device *dev,
 531                 const char *page, ssize_t count)
 532 {
 533         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 534         char *orig, *ptr, *arg_p, *opts;
 535         substring_t args[MAX_OPT_ARGS];
 536         int ret = 0, token;
 537         unsigned long tmp_readonly;
 538
 539         opts = kstrdup(page, GFP_KERNEL);
 540         if (!opts)
 541                 return -ENOMEM;
 542
 543         orig = opts;
 544
 545         while ((ptr = strsep(&opts, ",\n")) != NULL) {
 546                 if (!*ptr)
 547                         continue;
 548
 549                 token = match_token(ptr, tokens, args);
 550                 switch (token) {
 551                 case Opt_udev_path:
 552                         if (ib_dev->ibd_bd) {
 553                                 pr_err("Unable to set udev_path= while"
 554                                         " ib_dev->ibd_bd exists\n");
 555                                 ret = -EEXIST;
 556                                 goto out;
 557                         }
 558                         if (match_strlcpy(ib_dev->ibd_udev_path, &args[0],
 559                                 SE_UDEV_PATH_LEN) == 0) {
 560                                 ret = -EINVAL;
 561                                 break;
 562                         }
 563                         pr_debug("IBLOCK: Referencing UDEV path: %s\n",
 564                                         ib_dev->ibd_udev_path);
 565                         ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH;
 566                         break;
 567                 case Opt_readonly:
 568                         arg_p = match_strdup(&args[0]);
 569                         if (!arg_p) {
 570                                 ret = -ENOMEM;
 571                                 break;
 572                         }
 573                         ret = kstrtoul(arg_p, 0, &tmp_readonly);
 574                         kfree(arg_p);
 575                         if (ret < 0) {
 576                                 pr_err("kstrtoul() failed for"
 577                                                 " readonly=\n");
 578                                 goto out;
 579                         }
 580                         ib_dev->ibd_readonly = tmp_readonly;
 581                         pr_debug("IBLOCK: readonly: %d\n", ib_dev->ibd_readonly);
 582                         break;
 583                 case Opt_force:
 584                         break;
 585                 default:
 586                         break;
 587                 }
 588         }
 589
 590 out:
 591         kfree(orig);
 592         return (!ret) ? count : ret;
 593 }
 594
 595 static ssize_t iblock_show_configfs_dev_params(struct se_device *dev, char *b)
 596 {
 597         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 598         struct block_device *bd = ib_dev->ibd_bd;
 599         char buf[BDEVNAME_SIZE];
 600         ssize_t bl = 0;
 601
 602         if (bd)
 603                 bl += sprintf(b + bl, "iBlock device: %s",
 604                                 bdevname(bd, buf));
 605         if (ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)
 606                 bl += sprintf(b + bl, "  UDEV PATH: %s",
 607                                 ib_dev->ibd_udev_path);
 608         bl += sprintf(b + bl, "  readonly: %d\n", ib_dev->ibd_readonly);
 609
 610         bl += sprintf(b + bl, "        ");
 611         if (bd) {
 612                 bl += sprintf(b + bl, "Major: %d Minor: %d  %s\n",
 613                         MAJOR(bd->bd_dev), MINOR(bd->bd_dev), (!bd->bd_contains) ?
 614                         "" : (bd->bd_holder == ib_dev) ?
 615                         "CLAIMED: IBLOCK" : "CLAIMED: OS");
 616         } else {
 617                 bl += sprintf(b + bl, "Major: 0 Minor: 0\n");
 618         }
 619
 620         return bl;
 621 }
 622
 623 static int
 624 iblock_alloc_bip(struct se_cmd *cmd, struct bio *bio)
 625 {
 626         struct se_device *dev = cmd->se_dev;
 627         struct blk_integrity *bi;
 628         struct bio_integrity_payload *bip;
 629         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 630         struct scatterlist *sg;
 631         int i, rc;
 632
 633         bi = bdev_get_integrity(ib_dev->ibd_bd);
 634         if (!bi) {
 635                 pr_err("Unable to locate bio_integrity\n");
 636                 return -ENODEV;
 637         }
 638
 639         bip = bio_integrity_alloc(bio, GFP_NOIO, cmd->t_prot_nents);
 640         if (!bip) {
 641                 pr_err("Unable to allocate bio_integrity_payload\n");
 642                 return -ENOMEM;
 643         }
 644
 645         bip->bip_iter.bi_size = (cmd->data_length / dev->dev_attrib.block_size) *
 646                          dev->prot_length;
 647         bip->bip_iter.bi_sector = bio->bi_iter.bi_sector;
 648
 649         pr_debug("IBLOCK BIP Size: %u Sector: %llu\n", bip->bip_iter.bi_size,
 650                  (unsigned long long)bip->bip_iter.bi_sector);
 651
 652         for_each_sg(cmd->t_prot_sg, sg, cmd->t_prot_nents, i) {
 653
 654                 rc = bio_integrity_add_page(bio, sg_page(sg), sg->length,
 655                                             sg->offset);
 656                 if (rc != sg->length) {
 657                         pr_err("bio_integrity_add_page() failed; %d\n", rc);
 658                         return -ENOMEM;
 659                 }
 660
 661                 pr_debug("Added bio integrity page: %p length: %d offset; %d\n",
 662                          sg_page(sg), sg->length, sg->offset);
 663         }
 664
 665         return 0;
 666 }
 667
 668 static sense_reason_t
 669 iblock_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 670                   enum dma_data_direction data_direction)
 671 {
 672         struct se_device *dev = cmd->se_dev;
 673         struct iblock_req *ibr;
 674         struct bio *bio, *bio_start;
 675         struct bio_list list;
 676         struct scatterlist *sg;
 677         u32 sg_num = sgl_nents;
 678         sector_t block_lba;
 679         unsigned bio_cnt;
 680         int rw = 0;
 681         int i;
 682
 683         if (data_direction == DMA_TO_DEVICE) {
 684                 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 685                 struct request_queue *q = bdev_get_queue(ib_dev->ibd_bd);
 686                 /*
 687                  * Force writethrough using WRITE_FUA if a volatile write cache
 688                  * is not enabled, or if initiator set the Force Unit Access bit.
 689                  */
 690                 if (q->flush_flags & REQ_FUA) {
 691                         if (cmd->se_cmd_flags & SCF_FUA)
 692                                 rw = WRITE_FUA;
 693                         else if (!(q->flush_flags & REQ_FLUSH))
 694                                 rw = WRITE_FUA;
 695                         else
 696                                 rw = WRITE;
 697                 } else {
 698                         rw = WRITE;
 699                 }
 700         } else {
 701                 rw = READ;
 702         }
 703
 704         /*
 705          * Convert the blocksize advertised to the initiator to the 512 byte
 706          * units unconditionally used by the Linux block layer.
 707          */
 708         if (dev->dev_attrib.block_size == 4096)
 709                 block_lba = (cmd->t_task_lba << 3);
 710         else if (dev->dev_attrib.block_size == 2048)
 711                 block_lba = (cmd->t_task_lba << 2);
 712         else if (dev->dev_attrib.block_size == 1024)
 713                 block_lba = (cmd->t_task_lba << 1);
 714         else if (dev->dev_attrib.block_size == 512)
 715                 block_lba = cmd->t_task_lba;
 716         else {
 717                 pr_err("Unsupported SCSI -> BLOCK LBA conversion:"
 718                                 " %u\n", dev->dev_attrib.block_size);
 719                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 720         }
 721
 722         ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
 723         if (!ibr)
 724                 goto fail;
 725         cmd->priv = ibr;
 726
 727         if (!sgl_nents) {
 728                 atomic_set(&ibr->pending, 1);
 729                 iblock_complete_cmd(cmd);
 730                 return 0;
 731         }
 732
 733         bio = iblock_get_bio(cmd, block_lba, sgl_nents);
 734         if (!bio)
 735                 goto fail_free_ibr;
 736
 737         bio_start = bio;
 738         bio_list_init(&list);
 739         bio_list_add(&list, bio);
 740
 741         atomic_set(&ibr->pending, 2);
 742         bio_cnt = 1;
 743
 744         for_each_sg(sgl, sg, sgl_nents, i) {
 745                 /*
 746                  * XXX: if the length the device accepts is shorter than the
 747                  *      length of the S/G list entry this will cause and
 748                  *      endless loop.  Better hope no driver uses huge pages.
 749                  */
 750                 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
 751                                 != sg->length) {
 752                         if (bio_cnt >= IBLOCK_MAX_BIO_PER_TASK) {
 753                                 iblock_submit_bios(&list, rw);
 754                                 bio_cnt = 0;
 755                         }
 756
 757                         bio = iblock_get_bio(cmd, block_lba, sg_num);
 758                         if (!bio)
 759                                 goto fail_put_bios;
 760
 761                         atomic_inc(&ibr->pending);
 762                         bio_list_add(&list, bio);
 763                         bio_cnt++;
 764                 }
 765
 766                 /* Always in 512 byte units for Linux/Block */
 767                 block_lba += sg->length >> IBLOCK_LBA_SHIFT;
 768                 sg_num--;
 769         }
 770
 771         if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
 772                 int rc = iblock_alloc_bip(cmd, bio_start);
 773                 if (rc)
 774                         goto fail_put_bios;
 775         }
 776
 777         iblock_submit_bios(&list, rw);
 778         iblock_complete_cmd(cmd);
 779         return 0;
 780
 781 fail_put_bios:
 782         while ((bio = bio_list_pop(&list)))
 783                 bio_put(bio);
 784 fail_free_ibr:
 785         kfree(ibr);
 786 fail:
 787         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 788 }
 789
 790 static sector_t iblock_get_blocks(struct se_device *dev)
 791 {
 792         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 793         struct block_device *bd = ib_dev->ibd_bd;
 794         struct request_queue *q = bdev_get_queue(bd);
 795
 796         return iblock_emulate_read_cap_with_block_size(dev, bd, q);
 797 }
 798
 799 static sector_t iblock_get_alignment_offset_lbas(struct se_device *dev)
 800 {
 801         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 802         struct block_device *bd = ib_dev->ibd_bd;
 803         int ret;
 804
 805         ret = bdev_alignment_offset(bd);
 806         if (ret == -1)
 807                 return 0;
 808
 809         /* convert offset-bytes to offset-lbas */
 810         return ret / bdev_logical_block_size(bd);
 811 }
 812
 813 static unsigned int iblock_get_lbppbe(struct se_device *dev)
 814 {
 815         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 816         struct block_device *bd = ib_dev->ibd_bd;
 817         int logs_per_phys = bdev_physical_block_size(bd) / bdev_logical_block_size(bd);
 818
 819         return ilog2(logs_per_phys);
 820 }
 821
 822 static unsigned int iblock_get_io_min(struct se_device *dev)
 823 {
 824         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 825         struct block_device *bd = ib_dev->ibd_bd;
 826
 827         return bdev_io_min(bd);
 828 }
 829
 830 static unsigned int iblock_get_io_opt(struct se_device *dev)
 831 {
 832         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 833         struct block_device *bd = ib_dev->ibd_bd;
 834
 835         return bdev_io_opt(bd);
 836 }
 837
 838 static struct sbc_ops iblock_sbc_ops = {
 839         .execute_rw             = iblock_execute_rw,
 840         .execute_sync_cache     = iblock_execute_sync_cache,
 841         .execute_write_same     = iblock_execute_write_same,
 842         .execute_write_same_unmap = iblock_execute_write_same_unmap,
 843         .execute_unmap          = iblock_execute_unmap,
 844 };
 845
 846 static sense_reason_t
 847 iblock_parse_cdb(struct se_cmd *cmd)
 848 {
 849         return sbc_parse_cdb(cmd, &iblock_sbc_ops);
 850 }
 851
 852 static bool iblock_get_write_cache(struct se_device *dev)
 853 {
 854         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 855         struct block_device *bd = ib_dev->ibd_bd;
 856         struct request_queue *q = bdev_get_queue(bd);
 857
 858         return q->flush_flags & REQ_FLUSH;
 859 }
 860
 861 DEF_TB_DEFAULT_ATTRIBS(iblock);
 862
 863 static struct configfs_attribute *iblock_backend_dev_attrs[] = {
 864         &iblock_dev_attrib_emulate_model_alias.attr,
 865         &iblock_dev_attrib_emulate_dpo.attr,
 866         &iblock_dev_attrib_emulate_fua_write.attr,
 867         &iblock_dev_attrib_emulate_fua_read.attr,
 868         &iblock_dev_attrib_emulate_write_cache.attr,
 869         &iblock_dev_attrib_emulate_ua_intlck_ctrl.attr,
 870         &iblock_dev_attrib_emulate_tas.attr,
 871         &iblock_dev_attrib_emulate_tpu.attr,
 872         &iblock_dev_attrib_emulate_tpws.attr,
 873         &iblock_dev_attrib_emulate_caw.attr,
 874         &iblock_dev_attrib_emulate_3pc.attr,
 875         &iblock_dev_attrib_pi_prot_type.attr,
 876         &iblock_dev_attrib_hw_pi_prot_type.attr,
 877         &iblock_dev_attrib_pi_prot_format.attr,
 878         &iblock_dev_attrib_enforce_pr_isids.attr,
 879         &iblock_dev_attrib_is_nonrot.attr,
 880         &iblock_dev_attrib_emulate_rest_reord.attr,
 881         &iblock_dev_attrib_force_pr_aptpl.attr,
 882         &iblock_dev_attrib_hw_block_size.attr,
 883         &iblock_dev_attrib_block_size.attr,
 884         &iblock_dev_attrib_hw_max_sectors.attr,
 885         &iblock_dev_attrib_optimal_sectors.attr,
 886         &iblock_dev_attrib_hw_queue_depth.attr,
 887         &iblock_dev_attrib_queue_depth.attr,
 888         &iblock_dev_attrib_max_unmap_lba_count.attr,
 889         &iblock_dev_attrib_max_unmap_block_desc_count.attr,
 890         &iblock_dev_attrib_unmap_granularity.attr,
 891         &iblock_dev_attrib_unmap_granularity_alignment.attr,
 892         &iblock_dev_attrib_max_write_same_len.attr,
 893         NULL,
 894 };
 895
 896 static const struct target_backend_ops iblock_ops = {
 897         .name                   = "iblock",
 898         .inquiry_prod           = "IBLOCK",
 899         .inquiry_rev            = IBLOCK_VERSION,
 900         .owner                  = THIS_MODULE,
 901         .attach_hba             = iblock_attach_hba,
 902         .detach_hba             = iblock_detach_hba,
 903         .alloc_device           = iblock_alloc_device,
 904         .configure_device       = iblock_configure_device,
 905         .free_device            = iblock_free_device,
 906         .parse_cdb              = iblock_parse_cdb,
 907         .set_configfs_dev_params = iblock_set_configfs_dev_params,
 908         .show_configfs_dev_params = iblock_show_configfs_dev_params,
 909         .get_device_type        = sbc_get_device_type,
 910         .get_blocks             = iblock_get_blocks,
 911         .get_alignment_offset_lbas = iblock_get_alignment_offset_lbas,
 912         .get_lbppbe             = iblock_get_lbppbe,
 913         .get_io_min             = iblock_get_io_min,
 914         .get_io_opt             = iblock_get_io_opt,
 915         .get_write_cache        = iblock_get_write_cache,
 916         .tb_dev_attrib_attrs    = iblock_backend_dev_attrs,
 917 };
 918
 919 static int __init iblock_module_init(void)
 920 {
 921         return transport_backend_register(&iblock_ops);
 922 }
 923
 924 static void __exit iblock_module_exit(void)
 925 {
 926         target_backend_unregister(&iblock_ops);
 927 }
 928
 929 MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin");
 930 MODULE_AUTHOR("nab@Linux-iSCSI.org");
 931 MODULE_LICENSE("GPL");
 932
 933 module_init(iblock_module_init);
 934 module_exit(iblock_module_exit);