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/blk-integrity.h>
  20 #include <linux/slab.h>
  21 #include <linux/spinlock.h>
  22 #include <linux/bio.h>
  23 #include <linux/genhd.h>
  24 #include <linux/file.h>
  25 #include <linux/module.h>
  26 #include <linux/scatterlist.h>
  27 #include <scsi/scsi_proto.h>
  28 #include <asm/unaligned.h>
  29
  30 #include <target/target_core_base.h>
  31 #include <target/target_core_backend.h>
  32
  33 #include "target_core_iblock.h"
  34
  35 #define IBLOCK_MAX_BIO_PER_TASK  32     /* max # of bios to submit at a time */
  36 #define IBLOCK_BIO_POOL_SIZE    128
  37
  38 static inline struct iblock_dev *IBLOCK_DEV(struct se_device *dev)
  39 {
  40         return container_of(dev, struct iblock_dev, dev);
  41 }
  42
  43
  44 static int iblock_attach_hba(struct se_hba *hba, u32 host_id)
  45 {
  46         pr_debug("CORE_HBA[%d] - TCM iBlock HBA Driver %s on"
  47                 " Generic Target Core Stack %s\n", hba->hba_id,
  48                 IBLOCK_VERSION, TARGET_CORE_VERSION);
  49         return 0;
  50 }
  51
  52 static void iblock_detach_hba(struct se_hba *hba)
  53 {
  54 }
  55
  56 static struct se_device *iblock_alloc_device(struct se_hba *hba, const char *name)
  57 {
  58         struct iblock_dev *ib_dev = NULL;
  59
  60         ib_dev = kzalloc(sizeof(struct iblock_dev), GFP_KERNEL);
  61         if (!ib_dev) {
  62                 pr_err("Unable to allocate struct iblock_dev\n");
  63                 return NULL;
  64         }
  65
  66         ib_dev->ibd_plug = kcalloc(nr_cpu_ids, sizeof(*ib_dev->ibd_plug),
  67                                    GFP_KERNEL);
  68         if (!ib_dev->ibd_plug)
  69                 goto free_dev;
  70
  71         pr_debug( "IBLOCK: Allocated ib_dev for %s\n", name);
  72
  73         return &ib_dev->dev;
  74
  75 free_dev:
  76         kfree(ib_dev);
  77         return NULL;
  78 }
  79
  80 static int iblock_configure_device(struct se_device *dev)
  81 {
  82         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
  83         struct request_queue *q;
  84         struct block_device *bd = NULL;
  85         struct blk_integrity *bi;
  86         fmode_t mode;
  87         unsigned int max_write_zeroes_sectors;
  88         int ret;
  89
  90         if (!(ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)) {
  91                 pr_err("Missing udev_path= parameters for IBLOCK\n");
  92                 return -EINVAL;
  93         }
  94
  95         ret = bioset_init(&ib_dev->ibd_bio_set, IBLOCK_BIO_POOL_SIZE, 0, BIOSET_NEED_BVECS);
  96         if (ret) {
  97                 pr_err("IBLOCK: Unable to create bioset\n");
  98                 goto out;
  99         }
 100
 101         pr_debug( "IBLOCK: Claiming struct block_device: %s\n",
 102                         ib_dev->ibd_udev_path);
 103
 104         mode = FMODE_READ|FMODE_EXCL;
 105         if (!ib_dev->ibd_readonly)
 106                 mode |= FMODE_WRITE;
 107         else
 108                 dev->dev_flags |= DF_READ_ONLY;
 109
 110         bd = blkdev_get_by_path(ib_dev->ibd_udev_path, mode, ib_dev);
 111         if (IS_ERR(bd)) {
 112                 ret = PTR_ERR(bd);
 113                 goto out_free_bioset;
 114         }
 115         ib_dev->ibd_bd = bd;
 116
 117         q = bdev_get_queue(bd);
 118
 119         dev->dev_attrib.hw_block_size = bdev_logical_block_size(bd);
 120         dev->dev_attrib.hw_max_sectors = queue_max_hw_sectors(q);
 121         dev->dev_attrib.hw_queue_depth = q->nr_requests;
 122
 123         if (target_configure_unmap_from_queue(&dev->dev_attrib, q))
 124                 pr_debug("IBLOCK: BLOCK Discard support available,"
 125                          " disabled by default\n");
 126
 127         /*
 128          * Enable write same emulation for IBLOCK and use 0xFFFF as
 129          * the smaller WRITE_SAME(10) only has a two-byte block count.
 130          */
 131         max_write_zeroes_sectors = bdev_write_zeroes_sectors(bd);
 132         if (max_write_zeroes_sectors)
 133                 dev->dev_attrib.max_write_same_len = max_write_zeroes_sectors;
 134         else
 135                 dev->dev_attrib.max_write_same_len = 0xFFFF;
 136
 137         if (blk_queue_nonrot(q))
 138                 dev->dev_attrib.is_nonrot = 1;
 139
 140         bi = bdev_get_integrity(bd);
 141         if (bi) {
 142                 struct bio_set *bs = &ib_dev->ibd_bio_set;
 143
 144                 if (!strcmp(bi->profile->name, "T10-DIF-TYPE3-IP") ||
 145                     !strcmp(bi->profile->name, "T10-DIF-TYPE1-IP")) {
 146                         pr_err("IBLOCK export of blk_integrity: %s not"
 147                                " supported\n", bi->profile->name);
 148                         ret = -ENOSYS;
 149                         goto out_blkdev_put;
 150                 }
 151
 152                 if (!strcmp(bi->profile->name, "T10-DIF-TYPE3-CRC")) {
 153                         dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE3_PROT;
 154                 } else if (!strcmp(bi->profile->name, "T10-DIF-TYPE1-CRC")) {
 155                         dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE1_PROT;
 156                 }
 157
 158                 if (dev->dev_attrib.pi_prot_type) {
 159                         if (bioset_integrity_create(bs, IBLOCK_BIO_POOL_SIZE) < 0) {
 160                                 pr_err("Unable to allocate bioset for PI\n");
 161                                 ret = -ENOMEM;
 162                                 goto out_blkdev_put;
 163                         }
 164                         pr_debug("IBLOCK setup BIP bs->bio_integrity_pool: %p\n",
 165                                  &bs->bio_integrity_pool);
 166                 }
 167                 dev->dev_attrib.hw_pi_prot_type = dev->dev_attrib.pi_prot_type;
 168         }
 169
 170         return 0;
 171
 172 out_blkdev_put:
 173         blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
 174 out_free_bioset:
 175         bioset_exit(&ib_dev->ibd_bio_set);
 176 out:
 177         return ret;
 178 }
 179
 180 static void iblock_dev_call_rcu(struct rcu_head *p)
 181 {
 182         struct se_device *dev = container_of(p, struct se_device, rcu_head);
 183         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 184
 185         kfree(ib_dev->ibd_plug);
 186         kfree(ib_dev);
 187 }
 188
 189 static void iblock_free_device(struct se_device *dev)
 190 {
 191         call_rcu(&dev->rcu_head, iblock_dev_call_rcu);
 192 }
 193
 194 static void iblock_destroy_device(struct se_device *dev)
 195 {
 196         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 197
 198         if (ib_dev->ibd_bd != NULL)
 199                 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
 200         bioset_exit(&ib_dev->ibd_bio_set);
 201 }
 202
 203 static struct se_dev_plug *iblock_plug_device(struct se_device *se_dev)
 204 {
 205         struct iblock_dev *ib_dev = IBLOCK_DEV(se_dev);
 206         struct iblock_dev_plug *ib_dev_plug;
 207
 208         /*
 209          * Each se_device has a per cpu work this can be run from. We
 210          * shouldn't have multiple threads on the same cpu calling this
 211          * at the same time.
 212          */
 213         ib_dev_plug = &ib_dev->ibd_plug[raw_smp_processor_id()];
 214         if (test_and_set_bit(IBD_PLUGF_PLUGGED, &ib_dev_plug->flags))
 215                 return NULL;
 216
 217         blk_start_plug(&ib_dev_plug->blk_plug);
 218         return &ib_dev_plug->se_plug;
 219 }
 220
 221 static void iblock_unplug_device(struct se_dev_plug *se_plug)
 222 {
 223         struct iblock_dev_plug *ib_dev_plug = container_of(se_plug,
 224                                         struct iblock_dev_plug, se_plug);
 225
 226         blk_finish_plug(&ib_dev_plug->blk_plug);
 227         clear_bit(IBD_PLUGF_PLUGGED, &ib_dev_plug->flags);
 228 }
 229
 230 static unsigned long long iblock_emulate_read_cap_with_block_size(
 231         struct se_device *dev,
 232         struct block_device *bd,
 233         struct request_queue *q)
 234 {
 235         u32 block_size = bdev_logical_block_size(bd);
 236         unsigned long long blocks_long =
 237                 div_u64(bdev_nr_bytes(bd), block_size) - 1;
 238
 239         if (block_size == dev->dev_attrib.block_size)
 240                 return blocks_long;
 241
 242         switch (block_size) {
 243         case 4096:
 244                 switch (dev->dev_attrib.block_size) {
 245                 case 2048:
 246                         blocks_long <<= 1;
 247                         break;
 248                 case 1024:
 249                         blocks_long <<= 2;
 250                         break;
 251                 case 512:
 252                         blocks_long <<= 3;
 253                         break;
 254                 default:
 255                         break;
 256                 }
 257                 break;
 258         case 2048:
 259                 switch (dev->dev_attrib.block_size) {
 260                 case 4096:
 261                         blocks_long >>= 1;
 262                         break;
 263                 case 1024:
 264                         blocks_long <<= 1;
 265                         break;
 266                 case 512:
 267                         blocks_long <<= 2;
 268                         break;
 269                 default:
 270                         break;
 271                 }
 272                 break;
 273         case 1024:
 274                 switch (dev->dev_attrib.block_size) {
 275                 case 4096:
 276                         blocks_long >>= 2;
 277                         break;
 278                 case 2048:
 279                         blocks_long >>= 1;
 280                         break;
 281                 case 512:
 282                         blocks_long <<= 1;
 283                         break;
 284                 default:
 285                         break;
 286                 }
 287                 break;
 288         case 512:
 289                 switch (dev->dev_attrib.block_size) {
 290                 case 4096:
 291                         blocks_long >>= 3;
 292                         break;
 293                 case 2048:
 294                         blocks_long >>= 2;
 295                         break;
 296                 case 1024:
 297                         blocks_long >>= 1;
 298                         break;
 299                 default:
 300                         break;
 301                 }
 302                 break;
 303         default:
 304                 break;
 305         }
 306
 307         return blocks_long;
 308 }
 309
 310 static void iblock_complete_cmd(struct se_cmd *cmd)
 311 {
 312         struct iblock_req *ibr = cmd->priv;
 313         u8 status;
 314
 315         if (!refcount_dec_and_test(&ibr->pending))
 316                 return;
 317
 318         if (atomic_read(&ibr->ib_bio_err_cnt))
 319                 status = SAM_STAT_CHECK_CONDITION;
 320         else
 321                 status = SAM_STAT_GOOD;
 322
 323         target_complete_cmd(cmd, status);
 324         kfree(ibr);
 325 }
 326
 327 static void iblock_bio_done(struct bio *bio)
 328 {
 329         struct se_cmd *cmd = bio->bi_private;
 330         struct iblock_req *ibr = cmd->priv;
 331
 332         if (bio->bi_status) {
 333                 pr_err("bio error: %p,  err: %d\n", bio, bio->bi_status);
 334                 /*
 335                  * Bump the ib_bio_err_cnt and release bio.
 336                  */
 337                 atomic_inc(&ibr->ib_bio_err_cnt);
 338                 smp_mb__after_atomic();
 339         }
 340
 341         bio_put(bio);
 342
 343         iblock_complete_cmd(cmd);
 344 }
 345
 346 static struct bio *iblock_get_bio(struct se_cmd *cmd, sector_t lba, u32 sg_num,
 347                                   unsigned int opf)
 348 {
 349         struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
 350         struct bio *bio;
 351
 352         /*
 353          * Only allocate as many vector entries as the bio code allows us to,
 354          * we'll loop later on until we have handled the whole request.
 355          */
 356         bio = bio_alloc_bioset(GFP_NOIO, bio_max_segs(sg_num),
 357                                 &ib_dev->ibd_bio_set);
 358         if (!bio) {
 359                 pr_err("Unable to allocate memory for bio\n");
 360                 return NULL;
 361         }
 362
 363         bio_set_dev(bio, ib_dev->ibd_bd);
 364         bio->bi_private = cmd;
 365         bio->bi_end_io = &iblock_bio_done;
 366         bio->bi_iter.bi_sector = lba;
 367         bio->bi_opf = opf;
 368
 369         return bio;
 370 }
 371
 372 static void iblock_submit_bios(struct bio_list *list)
 373 {
 374         struct blk_plug plug;
 375         struct bio *bio;
 376         /*
 377          * The block layer handles nested plugs, so just plug/unplug to handle
 378          * fabric drivers that didn't support batching and multi bio cmds.
 379          */
 380         blk_start_plug(&plug);
 381         while ((bio = bio_list_pop(list)))
 382                 submit_bio(bio);
 383         blk_finish_plug(&plug);
 384 }
 385
 386 static void iblock_end_io_flush(struct bio *bio)
 387 {
 388         struct se_cmd *cmd = bio->bi_private;
 389
 390         if (bio->bi_status)
 391                 pr_err("IBLOCK: cache flush failed: %d\n", bio->bi_status);
 392
 393         if (cmd) {
 394                 if (bio->bi_status)
 395                         target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
 396                 else
 397                         target_complete_cmd(cmd, SAM_STAT_GOOD);
 398         }
 399
 400         bio_put(bio);
 401 }
 402
 403 /*
 404  * Implement SYCHRONIZE CACHE.  Note that we can't handle lba ranges and must
 405  * always flush the whole cache.
 406  */
 407 static sense_reason_t
 408 iblock_execute_sync_cache(struct se_cmd *cmd)
 409 {
 410         struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
 411         int immed = (cmd->t_task_cdb[1] & 0x2);
 412         struct bio *bio;
 413
 414         /*
 415          * If the Immediate bit is set, queue up the GOOD response
 416          * for this SYNCHRONIZE_CACHE op.
 417          */
 418         if (immed)
 419                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 420
 421         bio = bio_alloc(GFP_KERNEL, 0);
 422         bio->bi_end_io = iblock_end_io_flush;
 423         bio_set_dev(bio, ib_dev->ibd_bd);
 424         bio->bi_opf = REQ_OP_WRITE | REQ_PREFLUSH;
 425         if (!immed)
 426                 bio->bi_private = cmd;
 427         submit_bio(bio);
 428         return 0;
 429 }
 430
 431 static sense_reason_t
 432 iblock_execute_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
 433 {
 434         struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
 435         struct se_device *dev = cmd->se_dev;
 436         int ret;
 437
 438         ret = blkdev_issue_discard(bdev,
 439                                    target_to_linux_sector(dev, lba),
 440                                    target_to_linux_sector(dev,  nolb),
 441                                    GFP_KERNEL, 0);
 442         if (ret < 0) {
 443                 pr_err("blkdev_issue_discard() failed: %d\n", ret);
 444                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 445         }
 446
 447         return 0;
 448 }
 449
 450 static sense_reason_t
 451 iblock_execute_zero_out(struct block_device *bdev, struct se_cmd *cmd)
 452 {
 453         struct se_device *dev = cmd->se_dev;
 454         struct scatterlist *sg = &cmd->t_data_sg[0];
 455         unsigned char *buf, *not_zero;
 456         int ret;
 457
 458         buf = kmap(sg_page(sg)) + sg->offset;
 459         if (!buf)
 460                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 461         /*
 462          * Fall back to block_execute_write_same() slow-path if
 463          * incoming WRITE_SAME payload does not contain zeros.
 464          */
 465         not_zero = memchr_inv(buf, 0x00, cmd->data_length);
 466         kunmap(sg_page(sg));
 467
 468         if (not_zero)
 469                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 470
 471         ret = blkdev_issue_zeroout(bdev,
 472                                 target_to_linux_sector(dev, cmd->t_task_lba),
 473                                 target_to_linux_sector(dev,
 474                                         sbc_get_write_same_sectors(cmd)),
 475                                 GFP_KERNEL, BLKDEV_ZERO_NOUNMAP);
 476         if (ret)
 477                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 478
 479         target_complete_cmd(cmd, SAM_STAT_GOOD);
 480         return 0;
 481 }
 482
 483 static sense_reason_t
 484 iblock_execute_write_same(struct se_cmd *cmd)
 485 {
 486         struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
 487         struct iblock_req *ibr;
 488         struct scatterlist *sg;
 489         struct bio *bio;
 490         struct bio_list list;
 491         struct se_device *dev = cmd->se_dev;
 492         sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba);
 493         sector_t sectors = target_to_linux_sector(dev,
 494                                         sbc_get_write_same_sectors(cmd));
 495
 496         if (cmd->prot_op) {
 497                 pr_err("WRITE_SAME: Protection information with IBLOCK"
 498                        " backends not supported\n");
 499                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 500         }
 501         sg = &cmd->t_data_sg[0];
 502
 503         if (cmd->t_data_nents > 1 ||
 504             sg->length != cmd->se_dev->dev_attrib.block_size) {
 505                 pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
 506                         " block_size: %u\n", cmd->t_data_nents, sg->length,
 507                         cmd->se_dev->dev_attrib.block_size);
 508                 return TCM_INVALID_CDB_FIELD;
 509         }
 510
 511         if (bdev_write_zeroes_sectors(bdev)) {
 512                 if (!iblock_execute_zero_out(bdev, cmd))
 513                         return 0;
 514         }
 515
 516         ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
 517         if (!ibr)
 518                 goto fail;
 519         cmd->priv = ibr;
 520
 521         bio = iblock_get_bio(cmd, block_lba, 1, REQ_OP_WRITE);
 522         if (!bio)
 523                 goto fail_free_ibr;
 524
 525         bio_list_init(&list);
 526         bio_list_add(&list, bio);
 527
 528         refcount_set(&ibr->pending, 1);
 529
 530         while (sectors) {
 531                 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
 532                                 != sg->length) {
 533
 534                         bio = iblock_get_bio(cmd, block_lba, 1, REQ_OP_WRITE);
 535                         if (!bio)
 536                                 goto fail_put_bios;
 537
 538                         refcount_inc(&ibr->pending);
 539                         bio_list_add(&list, bio);
 540                 }
 541
 542                 /* Always in 512 byte units for Linux/Block */
 543                 block_lba += sg->length >> SECTOR_SHIFT;
 544                 sectors -= sg->length >> SECTOR_SHIFT;
 545         }
 546
 547         iblock_submit_bios(&list);
 548         return 0;
 549
 550 fail_put_bios:
 551         while ((bio = bio_list_pop(&list)))
 552                 bio_put(bio);
 553 fail_free_ibr:
 554         kfree(ibr);
 555 fail:
 556         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 557 }
 558
 559 enum {
 560         Opt_udev_path, Opt_readonly, Opt_force, Opt_err
 561 };
 562
 563 static match_table_t tokens = {
 564         {Opt_udev_path, "udev_path=%s"},
 565         {Opt_readonly, "readonly=%d"},
 566         {Opt_force, "force=%d"},
 567         {Opt_err, NULL}
 568 };
 569
 570 static ssize_t iblock_set_configfs_dev_params(struct se_device *dev,
 571                 const char *page, ssize_t count)
 572 {
 573         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 574         char *orig, *ptr, *arg_p, *opts;
 575         substring_t args[MAX_OPT_ARGS];
 576         int ret = 0, token;
 577         unsigned long tmp_readonly;
 578
 579         opts = kstrdup(page, GFP_KERNEL);
 580         if (!opts)
 581                 return -ENOMEM;
 582
 583         orig = opts;
 584
 585         while ((ptr = strsep(&opts, ",\n")) != NULL) {
 586                 if (!*ptr)
 587                         continue;
 588
 589                 token = match_token(ptr, tokens, args);
 590                 switch (token) {
 591                 case Opt_udev_path:
 592                         if (ib_dev->ibd_bd) {
 593                                 pr_err("Unable to set udev_path= while"
 594                                         " ib_dev->ibd_bd exists\n");
 595                                 ret = -EEXIST;
 596                                 goto out;
 597                         }
 598                         if (match_strlcpy(ib_dev->ibd_udev_path, &args[0],
 599                                 SE_UDEV_PATH_LEN) == 0) {
 600                                 ret = -EINVAL;
 601                                 break;
 602                         }
 603                         pr_debug("IBLOCK: Referencing UDEV path: %s\n",
 604                                         ib_dev->ibd_udev_path);
 605                         ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH;
 606                         break;
 607                 case Opt_readonly:
 608                         arg_p = match_strdup(&args[0]);
 609                         if (!arg_p) {
 610                                 ret = -ENOMEM;
 611                                 break;
 612                         }
 613                         ret = kstrtoul(arg_p, 0, &tmp_readonly);
 614                         kfree(arg_p);
 615                         if (ret < 0) {
 616                                 pr_err("kstrtoul() failed for"
 617                                                 " readonly=\n");
 618                                 goto out;
 619                         }
 620                         ib_dev->ibd_readonly = tmp_readonly;
 621                         pr_debug("IBLOCK: readonly: %d\n", ib_dev->ibd_readonly);
 622                         break;
 623                 case Opt_force:
 624                         break;
 625                 default:
 626                         break;
 627                 }
 628         }
 629
 630 out:
 631         kfree(orig);
 632         return (!ret) ? count : ret;
 633 }
 634
 635 static ssize_t iblock_show_configfs_dev_params(struct se_device *dev, char *b)
 636 {
 637         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 638         struct block_device *bd = ib_dev->ibd_bd;
 639         ssize_t bl = 0;
 640
 641         if (bd)
 642                 bl += sprintf(b + bl, "iBlock device: %pg", bd);
 643         if (ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)
 644                 bl += sprintf(b + bl, "  UDEV PATH: %s",
 645                                 ib_dev->ibd_udev_path);
 646         bl += sprintf(b + bl, "  readonly: %d\n", ib_dev->ibd_readonly);
 647
 648         bl += sprintf(b + bl, "        ");
 649         if (bd) {
 650                 bl += sprintf(b + bl, "Major: %d Minor: %d  %s\n",
 651                         MAJOR(bd->bd_dev), MINOR(bd->bd_dev),
 652                         "CLAIMED: IBLOCK");
 653         } else {
 654                 bl += sprintf(b + bl, "Major: 0 Minor: 0\n");
 655         }
 656
 657         return bl;
 658 }
 659
 660 static int
 661 iblock_alloc_bip(struct se_cmd *cmd, struct bio *bio,
 662                  struct sg_mapping_iter *miter)
 663 {
 664         struct se_device *dev = cmd->se_dev;
 665         struct blk_integrity *bi;
 666         struct bio_integrity_payload *bip;
 667         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 668         int rc;
 669         size_t resid, len;
 670
 671         bi = bdev_get_integrity(ib_dev->ibd_bd);
 672         if (!bi) {
 673                 pr_err("Unable to locate bio_integrity\n");
 674                 return -ENODEV;
 675         }
 676
 677         bip = bio_integrity_alloc(bio, GFP_NOIO, bio_max_segs(cmd->t_prot_nents));
 678         if (IS_ERR(bip)) {
 679                 pr_err("Unable to allocate bio_integrity_payload\n");
 680                 return PTR_ERR(bip);
 681         }
 682
 683         bip->bip_iter.bi_size = bio_integrity_bytes(bi, bio_sectors(bio));
 684         /* virtual start sector must be in integrity interval units */
 685         bip_set_seed(bip, bio->bi_iter.bi_sector >>
 686                                   (bi->interval_exp - SECTOR_SHIFT));
 687
 688         pr_debug("IBLOCK BIP Size: %u Sector: %llu\n", bip->bip_iter.bi_size,
 689                  (unsigned long long)bip->bip_iter.bi_sector);
 690
 691         resid = bip->bip_iter.bi_size;
 692         while (resid > 0 && sg_miter_next(miter)) {
 693
 694                 len = min_t(size_t, miter->length, resid);
 695                 rc = bio_integrity_add_page(bio, miter->page, len,
 696                                             offset_in_page(miter->addr));
 697                 if (rc != len) {
 698                         pr_err("bio_integrity_add_page() failed; %d\n", rc);
 699                         sg_miter_stop(miter);
 700                         return -ENOMEM;
 701                 }
 702
 703                 pr_debug("Added bio integrity page: %p length: %zu offset: %lu\n",
 704                           miter->page, len, offset_in_page(miter->addr));
 705
 706                 resid -= len;
 707                 if (len < miter->length)
 708                         miter->consumed -= miter->length - len;
 709         }
 710         sg_miter_stop(miter);
 711
 712         return 0;
 713 }
 714
 715 static sense_reason_t
 716 iblock_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 717                   enum dma_data_direction data_direction)
 718 {
 719         struct se_device *dev = cmd->se_dev;
 720         sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba);
 721         struct iblock_req *ibr;
 722         struct bio *bio;
 723         struct bio_list list;
 724         struct scatterlist *sg;
 725         u32 sg_num = sgl_nents;
 726         unsigned int opf;
 727         unsigned bio_cnt;
 728         int i, rc;
 729         struct sg_mapping_iter prot_miter;
 730         unsigned int miter_dir;
 731
 732         if (data_direction == DMA_TO_DEVICE) {
 733                 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 734                 struct request_queue *q = bdev_get_queue(ib_dev->ibd_bd);
 735                 /*
 736                  * Force writethrough using REQ_FUA if a volatile write cache
 737                  * is not enabled, or if initiator set the Force Unit Access bit.
 738                  */
 739                 opf = REQ_OP_WRITE;
 740                 miter_dir = SG_MITER_TO_SG;
 741                 if (test_bit(QUEUE_FLAG_FUA, &q->queue_flags)) {
 742                         if (cmd->se_cmd_flags & SCF_FUA)
 743                                 opf |= REQ_FUA;
 744                         else if (!test_bit(QUEUE_FLAG_WC, &q->queue_flags))
 745                                 opf |= REQ_FUA;
 746                 }
 747         } else {
 748                 opf = REQ_OP_READ;
 749                 miter_dir = SG_MITER_FROM_SG;
 750         }
 751
 752         ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
 753         if (!ibr)
 754                 goto fail;
 755         cmd->priv = ibr;
 756
 757         if (!sgl_nents) {
 758                 refcount_set(&ibr->pending, 1);
 759                 iblock_complete_cmd(cmd);
 760                 return 0;
 761         }
 762
 763         bio = iblock_get_bio(cmd, block_lba, sgl_nents, opf);
 764         if (!bio)
 765                 goto fail_free_ibr;
 766
 767         bio_list_init(&list);
 768         bio_list_add(&list, bio);
 769
 770         refcount_set(&ibr->pending, 2);
 771         bio_cnt = 1;
 772
 773         if (cmd->prot_type && dev->dev_attrib.pi_prot_type)
 774                 sg_miter_start(&prot_miter, cmd->t_prot_sg, cmd->t_prot_nents,
 775                                miter_dir);
 776
 777         for_each_sg(sgl, sg, sgl_nents, i) {
 778                 /*
 779                  * XXX: if the length the device accepts is shorter than the
 780                  *      length of the S/G list entry this will cause and
 781                  *      endless loop.  Better hope no driver uses huge pages.
 782                  */
 783                 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
 784                                 != sg->length) {
 785                         if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
 786                                 rc = iblock_alloc_bip(cmd, bio, &prot_miter);
 787                                 if (rc)
 788                                         goto fail_put_bios;
 789                         }
 790
 791                         if (bio_cnt >= IBLOCK_MAX_BIO_PER_TASK) {
 792                                 iblock_submit_bios(&list);
 793                                 bio_cnt = 0;
 794                         }
 795
 796                         bio = iblock_get_bio(cmd, block_lba, sg_num, opf);
 797                         if (!bio)
 798                                 goto fail_put_bios;
 799
 800                         refcount_inc(&ibr->pending);
 801                         bio_list_add(&list, bio);
 802                         bio_cnt++;
 803                 }
 804
 805                 /* Always in 512 byte units for Linux/Block */
 806                 block_lba += sg->length >> SECTOR_SHIFT;
 807                 sg_num--;
 808         }
 809
 810         if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
 811                 rc = iblock_alloc_bip(cmd, bio, &prot_miter);
 812                 if (rc)
 813                         goto fail_put_bios;
 814         }
 815
 816         iblock_submit_bios(&list);
 817         iblock_complete_cmd(cmd);
 818         return 0;
 819
 820 fail_put_bios:
 821         while ((bio = bio_list_pop(&list)))
 822                 bio_put(bio);
 823 fail_free_ibr:
 824         kfree(ibr);
 825 fail:
 826         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 827 }
 828
 829 static sector_t iblock_get_blocks(struct se_device *dev)
 830 {
 831         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 832         struct block_device *bd = ib_dev->ibd_bd;
 833         struct request_queue *q = bdev_get_queue(bd);
 834
 835         return iblock_emulate_read_cap_with_block_size(dev, bd, q);
 836 }
 837
 838 static sector_t iblock_get_alignment_offset_lbas(struct se_device *dev)
 839 {
 840         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 841         struct block_device *bd = ib_dev->ibd_bd;
 842         int ret;
 843
 844         ret = bdev_alignment_offset(bd);
 845         if (ret == -1)
 846                 return 0;
 847
 848         /* convert offset-bytes to offset-lbas */
 849         return ret / bdev_logical_block_size(bd);
 850 }
 851
 852 static unsigned int iblock_get_lbppbe(struct se_device *dev)
 853 {
 854         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 855         struct block_device *bd = ib_dev->ibd_bd;
 856         unsigned int logs_per_phys =
 857                 bdev_physical_block_size(bd) / bdev_logical_block_size(bd);
 858
 859         return ilog2(logs_per_phys);
 860 }
 861
 862 static unsigned int iblock_get_io_min(struct se_device *dev)
 863 {
 864         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 865         struct block_device *bd = ib_dev->ibd_bd;
 866
 867         return bdev_io_min(bd);
 868 }
 869
 870 static unsigned int iblock_get_io_opt(struct se_device *dev)
 871 {
 872         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 873         struct block_device *bd = ib_dev->ibd_bd;
 874
 875         return bdev_io_opt(bd);
 876 }
 877
 878 static struct sbc_ops iblock_sbc_ops = {
 879         .execute_rw             = iblock_execute_rw,
 880         .execute_sync_cache     = iblock_execute_sync_cache,
 881         .execute_write_same     = iblock_execute_write_same,
 882         .execute_unmap          = iblock_execute_unmap,
 883 };
 884
 885 static sense_reason_t
 886 iblock_parse_cdb(struct se_cmd *cmd)
 887 {
 888         return sbc_parse_cdb(cmd, &iblock_sbc_ops);
 889 }
 890
 891 static bool iblock_get_write_cache(struct se_device *dev)
 892 {
 893         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 894         struct block_device *bd = ib_dev->ibd_bd;
 895         struct request_queue *q = bdev_get_queue(bd);
 896
 897         return test_bit(QUEUE_FLAG_WC, &q->queue_flags);
 898 }
 899
 900 static const struct target_backend_ops iblock_ops = {
 901         .name                   = "iblock",
 902         .inquiry_prod           = "IBLOCK",
 903         .inquiry_rev            = IBLOCK_VERSION,
 904         .owner                  = THIS_MODULE,
 905         .attach_hba             = iblock_attach_hba,
 906         .detach_hba             = iblock_detach_hba,
 907         .alloc_device           = iblock_alloc_device,
 908         .configure_device       = iblock_configure_device,
 909         .destroy_device         = iblock_destroy_device,
 910         .free_device            = iblock_free_device,
 911         .plug_device            = iblock_plug_device,
 912         .unplug_device          = iblock_unplug_device,
 913         .parse_cdb              = iblock_parse_cdb,
 914         .set_configfs_dev_params = iblock_set_configfs_dev_params,
 915         .show_configfs_dev_params = iblock_show_configfs_dev_params,
 916         .get_device_type        = sbc_get_device_type,
 917         .get_blocks             = iblock_get_blocks,
 918         .get_alignment_offset_lbas = iblock_get_alignment_offset_lbas,
 919         .get_lbppbe             = iblock_get_lbppbe,
 920         .get_io_min             = iblock_get_io_min,
 921         .get_io_opt             = iblock_get_io_opt,
 922         .get_write_cache        = iblock_get_write_cache,
 923         .tb_dev_attrib_attrs    = sbc_attrib_attrs,
 924 };
 925
 926 static int __init iblock_module_init(void)
 927 {
 928         return transport_backend_register(&iblock_ops);
 929 }
 930
 931 static void __exit iblock_module_exit(void)
 932 {
 933         target_backend_unregister(&iblock_ops);
 934 }
 935
 936 MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin");
 937 MODULE_AUTHOR("nab@Linux-iSCSI.org");
 938 MODULE_LICENSE("GPL");
 939
 940 module_init(iblock_module_init);
 941 module_exit(iblock_module_exit);