drivers/target/target_core_iblock.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*******************************************************************************
   3  * Filename:  target_core_iblock.c
   4  *
   5  * This file contains the Storage Engine  <-> Linux BlockIO transport
   6  * specific functions.
   7  *
   8  * (c) Copyright 2003-2013 Datera, Inc.
   9  *
  10  * Nicholas A. Bellinger <nab@kernel.org>
  11  *
  12  ******************************************************************************/
  13
  14 #include <linux/string.h>
  15 #include <linux/parser.h>
  16 #include <linux/timer.h>
  17 #include <linux/fs.h>
  18 #include <linux/blkdev.h>
  19 #include <linux/slab.h>
  20 #include <linux/spinlock.h>
  21 #include <linux/bio.h>
  22 #include <linux/genhd.h>
  23 #include <linux/file.h>
  24 #include <linux/module.h>
  25 #include <scsi/scsi_proto.h>
  26 #include <asm/unaligned.h>
  27
  28 #include <target/target_core_base.h>
  29 #include <target/target_core_backend.h>
  30
  31 #include "target_core_iblock.h"
  32
  33 #define IBLOCK_MAX_BIO_PER_TASK  32     /* max # of bios to submit at a time */
  34 #define IBLOCK_BIO_POOL_SIZE    128
  35
  36 static inline struct iblock_dev *IBLOCK_DEV(struct se_device *dev)
  37 {
  38         return container_of(dev, struct iblock_dev, dev);
  39 }
  40
  41
  42 static int iblock_attach_hba(struct se_hba *hba, u32 host_id)
  43 {
  44         pr_debug("CORE_HBA[%d] - TCM iBlock HBA Driver %s on"
  45                 " Generic Target Core Stack %s\n", hba->hba_id,
  46                 IBLOCK_VERSION, TARGET_CORE_VERSION);
  47         return 0;
  48 }
  49
  50 static void iblock_detach_hba(struct se_hba *hba)
  51 {
  52 }
  53
  54 static struct se_device *iblock_alloc_device(struct se_hba *hba, const char *name)
  55 {
  56         struct iblock_dev *ib_dev = NULL;
  57
  58         ib_dev = kzalloc(sizeof(struct iblock_dev), GFP_KERNEL);
  59         if (!ib_dev) {
  60                 pr_err("Unable to allocate struct iblock_dev\n");
  61                 return NULL;
  62         }
  63
  64         pr_debug( "IBLOCK: Allocated ib_dev for %s\n", name);
  65
  66         return &ib_dev->dev;
  67 }
  68
  69 static int iblock_configure_device(struct se_device *dev)
  70 {
  71         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
  72         struct request_queue *q;
  73         struct block_device *bd = NULL;
  74         struct blk_integrity *bi;
  75         fmode_t mode;
  76         unsigned int max_write_zeroes_sectors;
  77         int ret = -ENOMEM;
  78
  79         if (!(ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)) {
  80                 pr_err("Missing udev_path= parameters for IBLOCK\n");
  81                 return -EINVAL;
  82         }
  83
  84         ret = bioset_init(&ib_dev->ibd_bio_set, IBLOCK_BIO_POOL_SIZE, 0, BIOSET_NEED_BVECS);
  85         if (ret) {
  86                 pr_err("IBLOCK: Unable to create bioset\n");
  87                 goto out;
  88         }
  89
  90         pr_debug( "IBLOCK: Claiming struct block_device: %s\n",
  91                         ib_dev->ibd_udev_path);
  92
  93         mode = FMODE_READ|FMODE_EXCL;
  94         if (!ib_dev->ibd_readonly)
  95                 mode |= FMODE_WRITE;
  96         else
  97                 dev->dev_flags |= DF_READ_ONLY;
  98
  99         bd = blkdev_get_by_path(ib_dev->ibd_udev_path, mode, ib_dev);
 100         if (IS_ERR(bd)) {
 101                 ret = PTR_ERR(bd);
 102                 goto out_free_bioset;
 103         }
 104         ib_dev->ibd_bd = bd;
 105
 106         q = bdev_get_queue(bd);
 107
 108         dev->dev_attrib.hw_block_size = bdev_logical_block_size(bd);
 109         dev->dev_attrib.hw_max_sectors = queue_max_hw_sectors(q);
 110         dev->dev_attrib.hw_queue_depth = q->nr_requests;
 111
 112         if (target_configure_unmap_from_queue(&dev->dev_attrib, q))
 113                 pr_debug("IBLOCK: BLOCK Discard support available,"
 114                          " disabled by default\n");
 115
 116         /*
 117          * Enable write same emulation for IBLOCK and use 0xFFFF as
 118          * the smaller WRITE_SAME(10) only has a two-byte block count.
 119          */
 120         max_write_zeroes_sectors = bdev_write_zeroes_sectors(bd);
 121         if (max_write_zeroes_sectors)
 122                 dev->dev_attrib.max_write_same_len = max_write_zeroes_sectors;
 123         else
 124                 dev->dev_attrib.max_write_same_len = 0xFFFF;
 125
 126         if (blk_queue_nonrot(q))
 127                 dev->dev_attrib.is_nonrot = 1;
 128
 129         bi = bdev_get_integrity(bd);
 130         if (bi) {
 131                 struct bio_set *bs = &ib_dev->ibd_bio_set;
 132
 133                 if (!strcmp(bi->profile->name, "T10-DIF-TYPE3-IP") ||
 134                     !strcmp(bi->profile->name, "T10-DIF-TYPE1-IP")) {
 135                         pr_err("IBLOCK export of blk_integrity: %s not"
 136                                " supported\n", bi->profile->name);
 137                         ret = -ENOSYS;
 138                         goto out_blkdev_put;
 139                 }
 140
 141                 if (!strcmp(bi->profile->name, "T10-DIF-TYPE3-CRC")) {
 142                         dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE3_PROT;
 143                 } else if (!strcmp(bi->profile->name, "T10-DIF-TYPE1-CRC")) {
 144                         dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE1_PROT;
 145                 }
 146
 147                 if (dev->dev_attrib.pi_prot_type) {
 148                         if (bioset_integrity_create(bs, IBLOCK_BIO_POOL_SIZE) < 0) {
 149                                 pr_err("Unable to allocate bioset for PI\n");
 150                                 ret = -ENOMEM;
 151                                 goto out_blkdev_put;
 152                         }
 153                         pr_debug("IBLOCK setup BIP bs->bio_integrity_pool: %p\n",
 154                                  &bs->bio_integrity_pool);
 155                 }
 156                 dev->dev_attrib.hw_pi_prot_type = dev->dev_attrib.pi_prot_type;
 157         }
 158
 159         return 0;
 160
 161 out_blkdev_put:
 162         blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
 163 out_free_bioset:
 164         bioset_exit(&ib_dev->ibd_bio_set);
 165 out:
 166         return ret;
 167 }
 168
 169 static void iblock_dev_call_rcu(struct rcu_head *p)
 170 {
 171         struct se_device *dev = container_of(p, struct se_device, rcu_head);
 172         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 173
 174         kfree(ib_dev);
 175 }
 176
 177 static void iblock_free_device(struct se_device *dev)
 178 {
 179         call_rcu(&dev->rcu_head, iblock_dev_call_rcu);
 180 }
 181
 182 static void iblock_destroy_device(struct se_device *dev)
 183 {
 184         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 185
 186         if (ib_dev->ibd_bd != NULL)
 187                 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
 188         bioset_exit(&ib_dev->ibd_bio_set);
 189 }
 190
 191 static unsigned long long iblock_emulate_read_cap_with_block_size(
 192         struct se_device *dev,
 193         struct block_device *bd,
 194         struct request_queue *q)
 195 {
 196         unsigned long long blocks_long = (div_u64(i_size_read(bd->bd_inode),
 197                                         bdev_logical_block_size(bd)) - 1);
 198         u32 block_size = bdev_logical_block_size(bd);
 199
 200         if (block_size == dev->dev_attrib.block_size)
 201                 return blocks_long;
 202
 203         switch (block_size) {
 204         case 4096:
 205                 switch (dev->dev_attrib.block_size) {
 206                 case 2048:
 207                         blocks_long <<= 1;
 208                         break;
 209                 case 1024:
 210                         blocks_long <<= 2;
 211                         break;
 212                 case 512:
 213                         blocks_long <<= 3;
 214                         break;
 215                 default:
 216                         break;
 217                 }
 218                 break;
 219         case 2048:
 220                 switch (dev->dev_attrib.block_size) {
 221                 case 4096:
 222                         blocks_long >>= 1;
 223                         break;
 224                 case 1024:
 225                         blocks_long <<= 1;
 226                         break;
 227                 case 512:
 228                         blocks_long <<= 2;
 229                         break;
 230                 default:
 231                         break;
 232                 }
 233                 break;
 234         case 1024:
 235                 switch (dev->dev_attrib.block_size) {
 236                 case 4096:
 237                         blocks_long >>= 2;
 238                         break;
 239                 case 2048:
 240                         blocks_long >>= 1;
 241                         break;
 242                 case 512:
 243                         blocks_long <<= 1;
 244                         break;
 245                 default:
 246                         break;
 247                 }
 248                 break;
 249         case 512:
 250                 switch (dev->dev_attrib.block_size) {
 251                 case 4096:
 252                         blocks_long >>= 3;
 253                         break;
 254                 case 2048:
 255                         blocks_long >>= 2;
 256                         break;
 257                 case 1024:
 258                         blocks_long >>= 1;
 259                         break;
 260                 default:
 261                         break;
 262                 }
 263                 break;
 264         default:
 265                 break;
 266         }
 267
 268         return blocks_long;
 269 }
 270
 271 static void iblock_complete_cmd(struct se_cmd *cmd)
 272 {
 273         struct iblock_req *ibr = cmd->priv;
 274         u8 status;
 275
 276         if (!refcount_dec_and_test(&ibr->pending))
 277                 return;
 278
 279         if (atomic_read(&ibr->ib_bio_err_cnt))
 280                 status = SAM_STAT_CHECK_CONDITION;
 281         else
 282                 status = SAM_STAT_GOOD;
 283
 284         target_complete_cmd(cmd, status);
 285         kfree(ibr);
 286 }
 287
 288 static void iblock_bio_done(struct bio *bio)
 289 {
 290         struct se_cmd *cmd = bio->bi_private;
 291         struct iblock_req *ibr = cmd->priv;
 292
 293         if (bio->bi_status) {
 294                 pr_err("bio error: %p,  err: %d\n", bio, bio->bi_status);
 295                 /*
 296                  * Bump the ib_bio_err_cnt and release bio.
 297                  */
 298                 atomic_inc(&ibr->ib_bio_err_cnt);
 299                 smp_mb__after_atomic();
 300         }
 301
 302         bio_put(bio);
 303
 304         iblock_complete_cmd(cmd);
 305 }
 306
 307 static struct bio *
 308 iblock_get_bio(struct se_cmd *cmd, sector_t lba, u32 sg_num, int op,
 309                int op_flags)
 310 {
 311         struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
 312         struct bio *bio;
 313
 314         /*
 315          * Only allocate as many vector entries as the bio code allows us to,
 316          * we'll loop later on until we have handled the whole request.
 317          */
 318         bio = bio_alloc_bioset(GFP_NOIO, bio_max_segs(sg_num),
 319                                 &ib_dev->ibd_bio_set);
 320         if (!bio) {
 321                 pr_err("Unable to allocate memory for bio\n");
 322                 return NULL;
 323         }
 324
 325         bio_set_dev(bio, ib_dev->ibd_bd);
 326         bio->bi_private = cmd;
 327         bio->bi_end_io = &iblock_bio_done;
 328         bio->bi_iter.bi_sector = lba;
 329         bio_set_op_attrs(bio, op, op_flags);
 330
 331         return bio;
 332 }
 333
 334 static void iblock_submit_bios(struct bio_list *list)
 335 {
 336         struct blk_plug plug;
 337         struct bio *bio;
 338
 339         blk_start_plug(&plug);
 340         while ((bio = bio_list_pop(list)))
 341                 submit_bio(bio);
 342         blk_finish_plug(&plug);
 343 }
 344
 345 static void iblock_end_io_flush(struct bio *bio)
 346 {
 347         struct se_cmd *cmd = bio->bi_private;
 348
 349         if (bio->bi_status)
 350                 pr_err("IBLOCK: cache flush failed: %d\n", bio->bi_status);
 351
 352         if (cmd) {
 353                 if (bio->bi_status)
 354                         target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
 355                 else
 356                         target_complete_cmd(cmd, SAM_STAT_GOOD);
 357         }
 358
 359         bio_put(bio);
 360 }
 361
 362 /*
 363  * Implement SYCHRONIZE CACHE.  Note that we can't handle lba ranges and must
 364  * always flush the whole cache.
 365  */
 366 static sense_reason_t
 367 iblock_execute_sync_cache(struct se_cmd *cmd)
 368 {
 369         struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
 370         int immed = (cmd->t_task_cdb[1] & 0x2);
 371         struct bio *bio;
 372
 373         /*
 374          * If the Immediate bit is set, queue up the GOOD response
 375          * for this SYNCHRONIZE_CACHE op.
 376          */
 377         if (immed)
 378                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 379
 380         bio = bio_alloc(GFP_KERNEL, 0);
 381         bio->bi_end_io = iblock_end_io_flush;
 382         bio_set_dev(bio, ib_dev->ibd_bd);
 383         bio->bi_opf = REQ_OP_WRITE | REQ_PREFLUSH;
 384         if (!immed)
 385                 bio->bi_private = cmd;
 386         submit_bio(bio);
 387         return 0;
 388 }
 389
 390 static sense_reason_t
 391 iblock_execute_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
 392 {
 393         struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
 394         struct se_device *dev = cmd->se_dev;
 395         int ret;
 396
 397         ret = blkdev_issue_discard(bdev,
 398                                    target_to_linux_sector(dev, lba),
 399                                    target_to_linux_sector(dev,  nolb),
 400                                    GFP_KERNEL, 0);
 401         if (ret < 0) {
 402                 pr_err("blkdev_issue_discard() failed: %d\n", ret);
 403                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 404         }
 405
 406         return 0;
 407 }
 408
 409 static sense_reason_t
 410 iblock_execute_zero_out(struct block_device *bdev, struct se_cmd *cmd)
 411 {
 412         struct se_device *dev = cmd->se_dev;
 413         struct scatterlist *sg = &cmd->t_data_sg[0];
 414         unsigned char *buf, *not_zero;
 415         int ret;
 416
 417         buf = kmap(sg_page(sg)) + sg->offset;
 418         if (!buf)
 419                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 420         /*
 421          * Fall back to block_execute_write_same() slow-path if
 422          * incoming WRITE_SAME payload does not contain zeros.
 423          */
 424         not_zero = memchr_inv(buf, 0x00, cmd->data_length);
 425         kunmap(sg_page(sg));
 426
 427         if (not_zero)
 428                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 429
 430         ret = blkdev_issue_zeroout(bdev,
 431                                 target_to_linux_sector(dev, cmd->t_task_lba),
 432                                 target_to_linux_sector(dev,
 433                                         sbc_get_write_same_sectors(cmd)),
 434                                 GFP_KERNEL, BLKDEV_ZERO_NOUNMAP);
 435         if (ret)
 436                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 437
 438         target_complete_cmd(cmd, GOOD);
 439         return 0;
 440 }
 441
 442 static sense_reason_t
 443 iblock_execute_write_same(struct se_cmd *cmd)
 444 {
 445         struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
 446         struct iblock_req *ibr;
 447         struct scatterlist *sg;
 448         struct bio *bio;
 449         struct bio_list list;
 450         struct se_device *dev = cmd->se_dev;
 451         sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba);
 452         sector_t sectors = target_to_linux_sector(dev,
 453                                         sbc_get_write_same_sectors(cmd));
 454
 455         if (cmd->prot_op) {
 456                 pr_err("WRITE_SAME: Protection information with IBLOCK"
 457                        " backends not supported\n");
 458                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 459         }
 460         sg = &cmd->t_data_sg[0];
 461
 462         if (cmd->t_data_nents > 1 ||
 463             sg->length != cmd->se_dev->dev_attrib.block_size) {
 464                 pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
 465                         " block_size: %u\n", cmd->t_data_nents, sg->length,
 466                         cmd->se_dev->dev_attrib.block_size);
 467                 return TCM_INVALID_CDB_FIELD;
 468         }
 469
 470         if (bdev_write_zeroes_sectors(bdev)) {
 471                 if (!iblock_execute_zero_out(bdev, cmd))
 472                         return 0;
 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, REQ_OP_WRITE, 0);
 481         if (!bio)
 482                 goto fail_free_ibr;
 483
 484         bio_list_init(&list);
 485         bio_list_add(&list, bio);
 486
 487         refcount_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, REQ_OP_WRITE,
 494                                              0);
 495                         if (!bio)
 496                                 goto fail_put_bios;
 497
 498                         refcount_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 >> SECTOR_SHIFT;
 504                 sectors -= sg->length >> SECTOR_SHIFT;
 505         }
 506
 507         iblock_submit_bios(&list);
 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),
 614                         "CLAIMED: IBLOCK");
 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                  struct sg_mapping_iter *miter)
 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         int rc;
 631         size_t resid, len;
 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, bio_max_segs(cmd->t_prot_nents));
 640         if (IS_ERR(bip)) {
 641                 pr_err("Unable to allocate bio_integrity_payload\n");
 642                 return PTR_ERR(bip);
 643         }
 644
 645         bip->bip_iter.bi_size = bio_integrity_bytes(bi, bio_sectors(bio));
 646         /* virtual start sector must be in integrity interval units */
 647         bip_set_seed(bip, bio->bi_iter.bi_sector >>
 648                                   (bi->interval_exp - SECTOR_SHIFT));
 649
 650         pr_debug("IBLOCK BIP Size: %u Sector: %llu\n", bip->bip_iter.bi_size,
 651                  (unsigned long long)bip->bip_iter.bi_sector);
 652
 653         resid = bip->bip_iter.bi_size;
 654         while (resid > 0 && sg_miter_next(miter)) {
 655
 656                 len = min_t(size_t, miter->length, resid);
 657                 rc = bio_integrity_add_page(bio, miter->page, len,
 658                                             offset_in_page(miter->addr));
 659                 if (rc != len) {
 660                         pr_err("bio_integrity_add_page() failed; %d\n", rc);
 661                         sg_miter_stop(miter);
 662                         return -ENOMEM;
 663                 }
 664
 665                 pr_debug("Added bio integrity page: %p length: %zu offset: %lu\n",
 666                           miter->page, len, offset_in_page(miter->addr));
 667
 668                 resid -= len;
 669                 if (len < miter->length)
 670                         miter->consumed -= miter->length - len;
 671         }
 672         sg_miter_stop(miter);
 673
 674         return 0;
 675 }
 676
 677 static sense_reason_t
 678 iblock_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 679                   enum dma_data_direction data_direction)
 680 {
 681         struct se_device *dev = cmd->se_dev;
 682         sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba);
 683         struct iblock_req *ibr;
 684         struct bio *bio;
 685         struct bio_list list;
 686         struct scatterlist *sg;
 687         u32 sg_num = sgl_nents;
 688         unsigned bio_cnt;
 689         int i, rc, op, op_flags = 0;
 690         struct sg_mapping_iter prot_miter;
 691
 692         if (data_direction == DMA_TO_DEVICE) {
 693                 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 694                 struct request_queue *q = bdev_get_queue(ib_dev->ibd_bd);
 695                 /*
 696                  * Force writethrough using REQ_FUA if a volatile write cache
 697                  * is not enabled, or if initiator set the Force Unit Access bit.
 698                  */
 699                 op = REQ_OP_WRITE;
 700                 if (test_bit(QUEUE_FLAG_FUA, &q->queue_flags)) {
 701                         if (cmd->se_cmd_flags & SCF_FUA)
 702                                 op_flags = REQ_FUA;
 703                         else if (!test_bit(QUEUE_FLAG_WC, &q->queue_flags))
 704                                 op_flags = REQ_FUA;
 705                 }
 706         } else {
 707                 op = REQ_OP_READ;
 708         }
 709
 710         ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
 711         if (!ibr)
 712                 goto fail;
 713         cmd->priv = ibr;
 714
 715         if (!sgl_nents) {
 716                 refcount_set(&ibr->pending, 1);
 717                 iblock_complete_cmd(cmd);
 718                 return 0;
 719         }
 720
 721         bio = iblock_get_bio(cmd, block_lba, sgl_nents, op, op_flags);
 722         if (!bio)
 723                 goto fail_free_ibr;
 724
 725         bio_list_init(&list);
 726         bio_list_add(&list, bio);
 727
 728         refcount_set(&ibr->pending, 2);
 729         bio_cnt = 1;
 730
 731         if (cmd->prot_type && dev->dev_attrib.pi_prot_type)
 732                 sg_miter_start(&prot_miter, cmd->t_prot_sg, cmd->t_prot_nents,
 733                                op == REQ_OP_READ ? SG_MITER_FROM_SG :
 734                                                    SG_MITER_TO_SG);
 735
 736         for_each_sg(sgl, sg, sgl_nents, i) {
 737                 /*
 738                  * XXX: if the length the device accepts is shorter than the
 739                  *      length of the S/G list entry this will cause and
 740                  *      endless loop.  Better hope no driver uses huge pages.
 741                  */
 742                 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
 743                                 != sg->length) {
 744                         if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
 745                                 rc = iblock_alloc_bip(cmd, bio, &prot_miter);
 746                                 if (rc)
 747                                         goto fail_put_bios;
 748                         }
 749
 750                         if (bio_cnt >= IBLOCK_MAX_BIO_PER_TASK) {
 751                                 iblock_submit_bios(&list);
 752                                 bio_cnt = 0;
 753                         }
 754
 755                         bio = iblock_get_bio(cmd, block_lba, sg_num, op,
 756                                              op_flags);
 757                         if (!bio)
 758                                 goto fail_put_bios;
 759
 760                         refcount_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 >> SECTOR_SHIFT;
 767                 sg_num--;
 768         }
 769
 770         if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
 771                 rc = iblock_alloc_bip(cmd, bio, &prot_miter);
 772                 if (rc)
 773                         goto fail_put_bios;
 774         }
 775
 776         iblock_submit_bios(&list);
 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_unmap          = iblock_execute_unmap,
 842 };
 843
 844 static sense_reason_t
 845 iblock_parse_cdb(struct se_cmd *cmd)
 846 {
 847         return sbc_parse_cdb(cmd, &iblock_sbc_ops);
 848 }
 849
 850 static bool iblock_get_write_cache(struct se_device *dev)
 851 {
 852         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 853         struct block_device *bd = ib_dev->ibd_bd;
 854         struct request_queue *q = bdev_get_queue(bd);
 855
 856         return test_bit(QUEUE_FLAG_WC, &q->queue_flags);
 857 }
 858
 859 static const struct target_backend_ops iblock_ops = {
 860         .name                   = "iblock",
 861         .inquiry_prod           = "IBLOCK",
 862         .inquiry_rev            = IBLOCK_VERSION,
 863         .owner                  = THIS_MODULE,
 864         .attach_hba             = iblock_attach_hba,
 865         .detach_hba             = iblock_detach_hba,
 866         .alloc_device           = iblock_alloc_device,
 867         .configure_device       = iblock_configure_device,
 868         .destroy_device         = iblock_destroy_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);