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                 default:
 215                         break;
 216                 }
 217                 break;
 218         case 2048:
 219                 switch (dev->dev_attrib.block_size) {
 220                 case 4096:
 221                         blocks_long >>= 1;
 222                         break;
 223                 case 1024:
 224                         blocks_long <<= 1;
 225                         break;
 226                 case 512:
 227                         blocks_long <<= 2;
 228                         break;
 229                 default:
 230                         break;
 231                 }
 232                 break;
 233         case 1024:
 234                 switch (dev->dev_attrib.block_size) {
 235                 case 4096:
 236                         blocks_long >>= 2;
 237                         break;
 238                 case 2048:
 239                         blocks_long >>= 1;
 240                         break;
 241                 case 512:
 242                         blocks_long <<= 1;
 243                         break;
 244                 default:
 245                         break;
 246                 }
 247                 break;
 248         case 512:
 249                 switch (dev->dev_attrib.block_size) {
 250                 case 4096:
 251                         blocks_long >>= 3;
 252                         break;
 253                 case 2048:
 254                         blocks_long >>= 2;
 255                         break;
 256                 case 1024:
 257                         blocks_long >>= 1;
 258                         break;
 259                 default:
 260                         break;
 261                 }
 262                 break;
 263         default:
 264                 break;
 265         }
 266
 267         return blocks_long;
 268 }
 269
 270 static void iblock_complete_cmd(struct se_cmd *cmd)
 271 {
 272         struct iblock_req *ibr = cmd->priv;
 273         u8 status;
 274
 275         if (!refcount_dec_and_test(&ibr->pending))
 276                 return;
 277
 278         if (atomic_read(&ibr->ib_bio_err_cnt))
 279                 status = SAM_STAT_CHECK_CONDITION;
 280         else
 281                 status = SAM_STAT_GOOD;
 282
 283         target_complete_cmd(cmd, status);
 284         kfree(ibr);
 285 }
 286
 287 static void iblock_bio_done(struct bio *bio)
 288 {
 289         struct se_cmd *cmd = bio->bi_private;
 290         struct iblock_req *ibr = cmd->priv;
 291
 292         if (bio->bi_status) {
 293                 pr_err("bio error: %p,  err: %d\n", bio, bio->bi_status);
 294                 /*
 295                  * Bump the ib_bio_err_cnt and release bio.
 296                  */
 297                 atomic_inc(&ibr->ib_bio_err_cnt);
 298                 smp_mb__after_atomic();
 299         }
 300
 301         bio_put(bio);
 302
 303         iblock_complete_cmd(cmd);
 304 }
 305
 306 static struct bio *
 307 iblock_get_bio(struct se_cmd *cmd, sector_t lba, u32 sg_num, int op,
 308                int op_flags)
 309 {
 310         struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
 311         struct bio *bio;
 312
 313         /*
 314          * Only allocate as many vector entries as the bio code allows us to,
 315          * we'll loop later on until we have handled the whole request.
 316          */
 317         if (sg_num > BIO_MAX_PAGES)
 318                 sg_num = BIO_MAX_PAGES;
 319
 320         bio = bio_alloc_bioset(GFP_NOIO, sg_num, &ib_dev->ibd_bio_set);
 321         if (!bio) {
 322                 pr_err("Unable to allocate memory for bio\n");
 323                 return NULL;
 324         }
 325
 326         bio_set_dev(bio, ib_dev->ibd_bd);
 327         bio->bi_private = cmd;
 328         bio->bi_end_io = &iblock_bio_done;
 329         bio->bi_iter.bi_sector = lba;
 330         bio_set_op_attrs(bio, op, op_flags);
 331
 332         return bio;
 333 }
 334
 335 static void iblock_submit_bios(struct bio_list *list)
 336 {
 337         struct blk_plug plug;
 338         struct bio *bio;
 339
 340         blk_start_plug(&plug);
 341         while ((bio = bio_list_pop(list)))
 342                 submit_bio(bio);
 343         blk_finish_plug(&plug);
 344 }
 345
 346 static void iblock_end_io_flush(struct bio *bio)
 347 {
 348         struct se_cmd *cmd = bio->bi_private;
 349
 350         if (bio->bi_status)
 351                 pr_err("IBLOCK: cache flush failed: %d\n", bio->bi_status);
 352
 353         if (cmd) {
 354                 if (bio->bi_status)
 355                         target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
 356                 else
 357                         target_complete_cmd(cmd, SAM_STAT_GOOD);
 358         }
 359
 360         bio_put(bio);
 361 }
 362
 363 /*
 364  * Implement SYCHRONIZE CACHE.  Note that we can't handle lba ranges and must
 365  * always flush the whole cache.
 366  */
 367 static sense_reason_t
 368 iblock_execute_sync_cache(struct se_cmd *cmd)
 369 {
 370         struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
 371         int immed = (cmd->t_task_cdb[1] & 0x2);
 372         struct bio *bio;
 373
 374         /*
 375          * If the Immediate bit is set, queue up the GOOD response
 376          * for this SYNCHRONIZE_CACHE op.
 377          */
 378         if (immed)
 379                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 380
 381         bio = bio_alloc(GFP_KERNEL, 0);
 382         bio->bi_end_io = iblock_end_io_flush;
 383         bio_set_dev(bio, ib_dev->ibd_bd);
 384         bio->bi_opf = REQ_OP_WRITE | REQ_PREFLUSH;
 385         if (!immed)
 386                 bio->bi_private = cmd;
 387         submit_bio(bio);
 388         return 0;
 389 }
 390
 391 static sense_reason_t
 392 iblock_execute_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
 393 {
 394         struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
 395         struct se_device *dev = cmd->se_dev;
 396         int ret;
 397
 398         ret = blkdev_issue_discard(bdev,
 399                                    target_to_linux_sector(dev, lba),
 400                                    target_to_linux_sector(dev,  nolb),
 401                                    GFP_KERNEL, 0);
 402         if (ret < 0) {
 403                 pr_err("blkdev_issue_discard() failed: %d\n", ret);
 404                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 405         }
 406
 407         return 0;
 408 }
 409
 410 static sense_reason_t
 411 iblock_execute_zero_out(struct block_device *bdev, struct se_cmd *cmd)
 412 {
 413         struct se_device *dev = cmd->se_dev;
 414         struct scatterlist *sg = &cmd->t_data_sg[0];
 415         unsigned char *buf, *not_zero;
 416         int ret;
 417
 418         buf = kmap(sg_page(sg)) + sg->offset;
 419         if (!buf)
 420                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 421         /*
 422          * Fall back to block_execute_write_same() slow-path if
 423          * incoming WRITE_SAME payload does not contain zeros.
 424          */
 425         not_zero = memchr_inv(buf, 0x00, cmd->data_length);
 426         kunmap(sg_page(sg));
 427
 428         if (not_zero)
 429                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 430
 431         ret = blkdev_issue_zeroout(bdev,
 432                                 target_to_linux_sector(dev, cmd->t_task_lba),
 433                                 target_to_linux_sector(dev,
 434                                         sbc_get_write_same_sectors(cmd)),
 435                                 GFP_KERNEL, BLKDEV_ZERO_NOUNMAP);
 436         if (ret)
 437                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 438
 439         target_complete_cmd(cmd, GOOD);
 440         return 0;
 441 }
 442
 443 static sense_reason_t
 444 iblock_execute_write_same(struct se_cmd *cmd)
 445 {
 446         struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
 447         struct iblock_req *ibr;
 448         struct scatterlist *sg;
 449         struct bio *bio;
 450         struct bio_list list;
 451         struct se_device *dev = cmd->se_dev;
 452         sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba);
 453         sector_t sectors = target_to_linux_sector(dev,
 454                                         sbc_get_write_same_sectors(cmd));
 455
 456         if (cmd->prot_op) {
 457                 pr_err("WRITE_SAME: Protection information with IBLOCK"
 458                        " backends not supported\n");
 459                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 460         }
 461         sg = &cmd->t_data_sg[0];
 462
 463         if (cmd->t_data_nents > 1 ||
 464             sg->length != cmd->se_dev->dev_attrib.block_size) {
 465                 pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
 466                         " block_size: %u\n", cmd->t_data_nents, sg->length,
 467                         cmd->se_dev->dev_attrib.block_size);
 468                 return TCM_INVALID_CDB_FIELD;
 469         }
 470
 471         if (bdev_write_zeroes_sectors(bdev)) {
 472                 if (!iblock_execute_zero_out(bdev, cmd))
 473                         return 0;
 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, REQ_OP_WRITE, 0);
 482         if (!bio)
 483                 goto fail_free_ibr;
 484
 485         bio_list_init(&list);
 486         bio_list_add(&list, bio);
 487
 488         refcount_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, REQ_OP_WRITE,
 495                                              0);
 496                         if (!bio)
 497                                 goto fail_put_bios;
 498
 499                         refcount_inc(&ibr->pending);
 500                         bio_list_add(&list, bio);
 501                 }
 502
 503                 /* Always in 512 byte units for Linux/Block */
 504                 block_lba += sg->length >> SECTOR_SHIFT;
 505                 sectors -= sg->length >> SECTOR_SHIFT;
 506         }
 507
 508         iblock_submit_bios(&list);
 509         return 0;
 510
 511 fail_put_bios:
 512         while ((bio = bio_list_pop(&list)))
 513                 bio_put(bio);
 514 fail_free_ibr:
 515         kfree(ibr);
 516 fail:
 517         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 518 }
 519
 520 enum {
 521         Opt_udev_path, Opt_readonly, Opt_force, Opt_err
 522 };
 523
 524 static match_table_t tokens = {
 525         {Opt_udev_path, "udev_path=%s"},
 526         {Opt_readonly, "readonly=%d"},
 527         {Opt_force, "force=%d"},
 528         {Opt_err, NULL}
 529 };
 530
 531 static ssize_t iblock_set_configfs_dev_params(struct se_device *dev,
 532                 const char *page, ssize_t count)
 533 {
 534         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 535         char *orig, *ptr, *arg_p, *opts;
 536         substring_t args[MAX_OPT_ARGS];
 537         int ret = 0, token;
 538         unsigned long tmp_readonly;
 539
 540         opts = kstrdup(page, GFP_KERNEL);
 541         if (!opts)
 542                 return -ENOMEM;
 543
 544         orig = opts;
 545
 546         while ((ptr = strsep(&opts, ",\n")) != NULL) {
 547                 if (!*ptr)
 548                         continue;
 549
 550                 token = match_token(ptr, tokens, args);
 551                 switch (token) {
 552                 case Opt_udev_path:
 553                         if (ib_dev->ibd_bd) {
 554                                 pr_err("Unable to set udev_path= while"
 555                                         " ib_dev->ibd_bd exists\n");
 556                                 ret = -EEXIST;
 557                                 goto out;
 558                         }
 559                         if (match_strlcpy(ib_dev->ibd_udev_path, &args[0],
 560                                 SE_UDEV_PATH_LEN) == 0) {
 561                                 ret = -EINVAL;
 562                                 break;
 563                         }
 564                         pr_debug("IBLOCK: Referencing UDEV path: %s\n",
 565                                         ib_dev->ibd_udev_path);
 566                         ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH;
 567                         break;
 568                 case Opt_readonly:
 569                         arg_p = match_strdup(&args[0]);
 570                         if (!arg_p) {
 571                                 ret = -ENOMEM;
 572                                 break;
 573                         }
 574                         ret = kstrtoul(arg_p, 0, &tmp_readonly);
 575                         kfree(arg_p);
 576                         if (ret < 0) {
 577                                 pr_err("kstrtoul() failed for"
 578                                                 " readonly=\n");
 579                                 goto out;
 580                         }
 581                         ib_dev->ibd_readonly = tmp_readonly;
 582                         pr_debug("IBLOCK: readonly: %d\n", ib_dev->ibd_readonly);
 583                         break;
 584                 case Opt_force:
 585                         break;
 586                 default:
 587                         break;
 588                 }
 589         }
 590
 591 out:
 592         kfree(orig);
 593         return (!ret) ? count : ret;
 594 }
 595
 596 static ssize_t iblock_show_configfs_dev_params(struct se_device *dev, char *b)
 597 {
 598         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 599         struct block_device *bd = ib_dev->ibd_bd;
 600         char buf[BDEVNAME_SIZE];
 601         ssize_t bl = 0;
 602
 603         if (bd)
 604                 bl += sprintf(b + bl, "iBlock device: %s",
 605                                 bdevname(bd, buf));
 606         if (ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)
 607                 bl += sprintf(b + bl, "  UDEV PATH: %s",
 608                                 ib_dev->ibd_udev_path);
 609         bl += sprintf(b + bl, "  readonly: %d\n", ib_dev->ibd_readonly);
 610
 611         bl += sprintf(b + bl, "        ");
 612         if (bd) {
 613                 bl += sprintf(b + bl, "Major: %d Minor: %d  %s\n",
 614                         MAJOR(bd->bd_dev), MINOR(bd->bd_dev),
 615                         "CLAIMED: IBLOCK");
 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                  struct sg_mapping_iter *miter)
 626 {
 627         struct se_device *dev = cmd->se_dev;
 628         struct blk_integrity *bi;
 629         struct bio_integrity_payload *bip;
 630         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 631         int rc;
 632         size_t resid, len;
 633
 634         bi = bdev_get_integrity(ib_dev->ibd_bd);
 635         if (!bi) {
 636                 pr_err("Unable to locate bio_integrity\n");
 637                 return -ENODEV;
 638         }
 639
 640         bip = bio_integrity_alloc(bio, GFP_NOIO,
 641                         min_t(unsigned int, cmd->t_prot_nents, BIO_MAX_PAGES));
 642         if (IS_ERR(bip)) {
 643                 pr_err("Unable to allocate bio_integrity_payload\n");
 644                 return PTR_ERR(bip);
 645         }
 646
 647         bip->bip_iter.bi_size = bio_integrity_bytes(bi, bio_sectors(bio));
 648         /* virtual start sector must be in integrity interval units */
 649         bip_set_seed(bip, bio->bi_iter.bi_sector >>
 650                                   (bi->interval_exp - SECTOR_SHIFT));
 651
 652         pr_debug("IBLOCK BIP Size: %u Sector: %llu\n", bip->bip_iter.bi_size,
 653                  (unsigned long long)bip->bip_iter.bi_sector);
 654
 655         resid = bip->bip_iter.bi_size;
 656         while (resid > 0 && sg_miter_next(miter)) {
 657
 658                 len = min_t(size_t, miter->length, resid);
 659                 rc = bio_integrity_add_page(bio, miter->page, len,
 660                                             offset_in_page(miter->addr));
 661                 if (rc != len) {
 662                         pr_err("bio_integrity_add_page() failed; %d\n", rc);
 663                         sg_miter_stop(miter);
 664                         return -ENOMEM;
 665                 }
 666
 667                 pr_debug("Added bio integrity page: %p length: %zu offset: %lu\n",
 668                           miter->page, len, offset_in_page(miter->addr));
 669
 670                 resid -= len;
 671                 if (len < miter->length)
 672                         miter->consumed -= miter->length - len;
 673         }
 674         sg_miter_stop(miter);
 675
 676         return 0;
 677 }
 678
 679 static sense_reason_t
 680 iblock_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 681                   enum dma_data_direction data_direction)
 682 {
 683         struct se_device *dev = cmd->se_dev;
 684         sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba);
 685         struct iblock_req *ibr;
 686         struct bio *bio;
 687         struct bio_list list;
 688         struct scatterlist *sg;
 689         u32 sg_num = sgl_nents;
 690         unsigned bio_cnt;
 691         int i, rc, op, op_flags = 0;
 692         struct sg_mapping_iter prot_miter;
 693
 694         if (data_direction == DMA_TO_DEVICE) {
 695                 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 696                 struct request_queue *q = bdev_get_queue(ib_dev->ibd_bd);
 697                 /*
 698                  * Force writethrough using REQ_FUA if a volatile write cache
 699                  * is not enabled, or if initiator set the Force Unit Access bit.
 700                  */
 701                 op = REQ_OP_WRITE;
 702                 if (test_bit(QUEUE_FLAG_FUA, &q->queue_flags)) {
 703                         if (cmd->se_cmd_flags & SCF_FUA)
 704                                 op_flags = REQ_FUA;
 705                         else if (!test_bit(QUEUE_FLAG_WC, &q->queue_flags))
 706                                 op_flags = REQ_FUA;
 707                 }
 708         } else {
 709                 op = REQ_OP_READ;
 710         }
 711
 712         ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
 713         if (!ibr)
 714                 goto fail;
 715         cmd->priv = ibr;
 716
 717         if (!sgl_nents) {
 718                 refcount_set(&ibr->pending, 1);
 719                 iblock_complete_cmd(cmd);
 720                 return 0;
 721         }
 722
 723         bio = iblock_get_bio(cmd, block_lba, sgl_nents, op, op_flags);
 724         if (!bio)
 725                 goto fail_free_ibr;
 726
 727         bio_list_init(&list);
 728         bio_list_add(&list, bio);
 729
 730         refcount_set(&ibr->pending, 2);
 731         bio_cnt = 1;
 732
 733         if (cmd->prot_type && dev->dev_attrib.pi_prot_type)
 734                 sg_miter_start(&prot_miter, cmd->t_prot_sg, cmd->t_prot_nents,
 735                                op == REQ_OP_READ ? SG_MITER_FROM_SG :
 736                                                    SG_MITER_TO_SG);
 737
 738         for_each_sg(sgl, sg, sgl_nents, i) {
 739                 /*
 740                  * XXX: if the length the device accepts is shorter than the
 741                  *      length of the S/G list entry this will cause and
 742                  *      endless loop.  Better hope no driver uses huge pages.
 743                  */
 744                 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
 745                                 != sg->length) {
 746                         if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
 747                                 rc = iblock_alloc_bip(cmd, bio, &prot_miter);
 748                                 if (rc)
 749                                         goto fail_put_bios;
 750                         }
 751
 752                         if (bio_cnt >= IBLOCK_MAX_BIO_PER_TASK) {
 753                                 iblock_submit_bios(&list);
 754                                 bio_cnt = 0;
 755                         }
 756
 757                         bio = iblock_get_bio(cmd, block_lba, sg_num, op,
 758                                              op_flags);
 759                         if (!bio)
 760                                 goto fail_put_bios;
 761
 762                         refcount_inc(&ibr->pending);
 763                         bio_list_add(&list, bio);
 764                         bio_cnt++;
 765                 }
 766
 767                 /* Always in 512 byte units for Linux/Block */
 768                 block_lba += sg->length >> SECTOR_SHIFT;
 769                 sg_num--;
 770         }
 771
 772         if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
 773                 rc = iblock_alloc_bip(cmd, bio, &prot_miter);
 774                 if (rc)
 775                         goto fail_put_bios;
 776         }
 777
 778         iblock_submit_bios(&list);
 779         iblock_complete_cmd(cmd);
 780         return 0;
 781
 782 fail_put_bios:
 783         while ((bio = bio_list_pop(&list)))
 784                 bio_put(bio);
 785 fail_free_ibr:
 786         kfree(ibr);
 787 fail:
 788         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 789 }
 790
 791 static sector_t iblock_get_blocks(struct se_device *dev)
 792 {
 793         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 794         struct block_device *bd = ib_dev->ibd_bd;
 795         struct request_queue *q = bdev_get_queue(bd);
 796
 797         return iblock_emulate_read_cap_with_block_size(dev, bd, q);
 798 }
 799
 800 static sector_t iblock_get_alignment_offset_lbas(struct se_device *dev)
 801 {
 802         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 803         struct block_device *bd = ib_dev->ibd_bd;
 804         int ret;
 805
 806         ret = bdev_alignment_offset(bd);
 807         if (ret == -1)
 808                 return 0;
 809
 810         /* convert offset-bytes to offset-lbas */
 811         return ret / bdev_logical_block_size(bd);
 812 }
 813
 814 static unsigned int iblock_get_lbppbe(struct se_device *dev)
 815 {
 816         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 817         struct block_device *bd = ib_dev->ibd_bd;
 818         int logs_per_phys = bdev_physical_block_size(bd) / bdev_logical_block_size(bd);
 819
 820         return ilog2(logs_per_phys);
 821 }
 822
 823 static unsigned int iblock_get_io_min(struct se_device *dev)
 824 {
 825         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 826         struct block_device *bd = ib_dev->ibd_bd;
 827
 828         return bdev_io_min(bd);
 829 }
 830
 831 static unsigned int iblock_get_io_opt(struct se_device *dev)
 832 {
 833         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 834         struct block_device *bd = ib_dev->ibd_bd;
 835
 836         return bdev_io_opt(bd);
 837 }
 838
 839 static struct sbc_ops iblock_sbc_ops = {
 840         .execute_rw             = iblock_execute_rw,
 841         .execute_sync_cache     = iblock_execute_sync_cache,
 842         .execute_write_same     = iblock_execute_write_same,
 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 test_bit(QUEUE_FLAG_WC, &q->queue_flags);
 859 }
 860
 861 static const struct target_backend_ops iblock_ops = {
 862         .name                   = "iblock",
 863         .inquiry_prod           = "IBLOCK",
 864         .inquiry_rev            = IBLOCK_VERSION,
 865         .owner                  = THIS_MODULE,
 866         .attach_hba             = iblock_attach_hba,
 867         .detach_hba             = iblock_detach_hba,
 868         .alloc_device           = iblock_alloc_device,
 869         .configure_device       = iblock_configure_device,
 870         .destroy_device         = iblock_destroy_device,
 871         .free_device            = iblock_free_device,
 872         .parse_cdb              = iblock_parse_cdb,
 873         .set_configfs_dev_params = iblock_set_configfs_dev_params,
 874         .show_configfs_dev_params = iblock_show_configfs_dev_params,
 875         .get_device_type        = sbc_get_device_type,
 876         .get_blocks             = iblock_get_blocks,
 877         .get_alignment_offset_lbas = iblock_get_alignment_offset_lbas,
 878         .get_lbppbe             = iblock_get_lbppbe,
 879         .get_io_min             = iblock_get_io_min,
 880         .get_io_opt             = iblock_get_io_opt,
 881         .get_write_cache        = iblock_get_write_cache,
 882         .tb_dev_attrib_attrs    = sbc_attrib_attrs,
 883 };
 884
 885 static int __init iblock_module_init(void)
 886 {
 887         return transport_backend_register(&iblock_ops);
 888 }
 889
 890 static void __exit iblock_module_exit(void)
 891 {
 892         target_backend_unregister(&iblock_ops);
 893 }
 894
 895 MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin");
 896 MODULE_AUTHOR("nab@Linux-iSCSI.org");
 897 MODULE_LICENSE("GPL");
 898
 899 module_init(iblock_module_init);
 900 module_exit(iblock_module_exit);