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/file.h>
  24 #include <linux/module.h>
  25 #include <linux/scatterlist.h>
  26 #include <scsi/scsi_proto.h>
  27 #include <asm/unaligned.h>
  28
  29 #include <target/target_core_base.h>
  30 #include <target/target_core_backend.h>
  31
  32 #include "target_core_iblock.h"
  33
  34 #define IBLOCK_MAX_BIO_PER_TASK  32     /* max # of bios to submit at a time */
  35 #define IBLOCK_BIO_POOL_SIZE    128
  36
  37 static inline struct iblock_dev *IBLOCK_DEV(struct se_device *dev)
  38 {
  39         return container_of(dev, struct iblock_dev, dev);
  40 }
  41
  42
  43 static int iblock_attach_hba(struct se_hba *hba, u32 host_id)
  44 {
  45         pr_debug("CORE_HBA[%d] - TCM iBlock HBA Driver %s on"
  46                 " Generic Target Core Stack %s\n", hba->hba_id,
  47                 IBLOCK_VERSION, TARGET_CORE_VERSION);
  48         return 0;
  49 }
  50
  51 static void iblock_detach_hba(struct se_hba *hba)
  52 {
  53 }
  54
  55 static struct se_device *iblock_alloc_device(struct se_hba *hba, const char *name)
  56 {
  57         struct iblock_dev *ib_dev = NULL;
  58
  59         ib_dev = kzalloc(sizeof(struct iblock_dev), GFP_KERNEL);
  60         if (!ib_dev) {
  61                 pr_err("Unable to allocate struct iblock_dev\n");
  62                 return NULL;
  63         }
  64
  65         ib_dev->ibd_plug = kcalloc(nr_cpu_ids, sizeof(*ib_dev->ibd_plug),
  66                                    GFP_KERNEL);
  67         if (!ib_dev->ibd_plug)
  68                 goto free_dev;
  69
  70         pr_debug( "IBLOCK: Allocated ib_dev for %s\n", name);
  71
  72         return &ib_dev->dev;
  73
  74 free_dev:
  75         kfree(ib_dev);
  76         return NULL;
  77 }
  78
  79 static int iblock_configure_device(struct se_device *dev)
  80 {
  81         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
  82         struct request_queue *q;
  83         struct block_device *bd = NULL;
  84         struct blk_integrity *bi;
  85         fmode_t mode;
  86         unsigned int max_write_zeroes_sectors;
  87         int ret;
  88
  89         if (!(ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)) {
  90                 pr_err("Missing udev_path= parameters for IBLOCK\n");
  91                 return -EINVAL;
  92         }
  93
  94         ret = bioset_init(&ib_dev->ibd_bio_set, IBLOCK_BIO_POOL_SIZE, 0, BIOSET_NEED_BVECS);
  95         if (ret) {
  96                 pr_err("IBLOCK: Unable to create bioset\n");
  97                 goto out;
  98         }
  99
 100         pr_debug( "IBLOCK: Claiming struct block_device: %s\n",
 101                         ib_dev->ibd_udev_path);
 102
 103         mode = FMODE_READ|FMODE_EXCL;
 104         if (!ib_dev->ibd_readonly)
 105                 mode |= FMODE_WRITE;
 106         else
 107                 dev->dev_flags |= DF_READ_ONLY;
 108
 109         bd = blkdev_get_by_path(ib_dev->ibd_udev_path, mode, ib_dev);
 110         if (IS_ERR(bd)) {
 111                 ret = PTR_ERR(bd);
 112                 goto out_free_bioset;
 113         }
 114         ib_dev->ibd_bd = bd;
 115
 116         q = bdev_get_queue(bd);
 117
 118         dev->dev_attrib.hw_block_size = bdev_logical_block_size(bd);
 119         dev->dev_attrib.hw_max_sectors = queue_max_hw_sectors(q);
 120         dev->dev_attrib.hw_queue_depth = q->nr_requests;
 121
 122         if (target_configure_unmap_from_queue(&dev->dev_attrib, bd))
 123                 pr_debug("IBLOCK: BLOCK Discard support available,"
 124                          " disabled by default\n");
 125
 126         /*
 127          * Enable write same emulation for IBLOCK and use 0xFFFF as
 128          * the smaller WRITE_SAME(10) only has a two-byte block count.
 129          */
 130         max_write_zeroes_sectors = bdev_write_zeroes_sectors(bd);
 131         if (max_write_zeroes_sectors)
 132                 dev->dev_attrib.max_write_same_len = max_write_zeroes_sectors;
 133         else
 134                 dev->dev_attrib.max_write_same_len = 0xFFFF;
 135
 136         if (bdev_nonrot(bd))
 137                 dev->dev_attrib.is_nonrot = 1;
 138
 139         bi = bdev_get_integrity(bd);
 140         if (bi) {
 141                 struct bio_set *bs = &ib_dev->ibd_bio_set;
 142
 143                 if (!strcmp(bi->profile->name, "T10-DIF-TYPE3-IP") ||
 144                     !strcmp(bi->profile->name, "T10-DIF-TYPE1-IP")) {
 145                         pr_err("IBLOCK export of blk_integrity: %s not"
 146                                " supported\n", bi->profile->name);
 147                         ret = -ENOSYS;
 148                         goto out_blkdev_put;
 149                 }
 150
 151                 if (!strcmp(bi->profile->name, "T10-DIF-TYPE3-CRC")) {
 152                         dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE3_PROT;
 153                 } else if (!strcmp(bi->profile->name, "T10-DIF-TYPE1-CRC")) {
 154                         dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE1_PROT;
 155                 }
 156
 157                 if (dev->dev_attrib.pi_prot_type) {
 158                         if (bioset_integrity_create(bs, IBLOCK_BIO_POOL_SIZE) < 0) {
 159                                 pr_err("Unable to allocate bioset for PI\n");
 160                                 ret = -ENOMEM;
 161                                 goto out_blkdev_put;
 162                         }
 163                         pr_debug("IBLOCK setup BIP bs->bio_integrity_pool: %p\n",
 164                                  &bs->bio_integrity_pool);
 165                 }
 166                 dev->dev_attrib.hw_pi_prot_type = dev->dev_attrib.pi_prot_type;
 167         }
 168
 169         return 0;
 170
 171 out_blkdev_put:
 172         blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
 173 out_free_bioset:
 174         bioset_exit(&ib_dev->ibd_bio_set);
 175 out:
 176         return ret;
 177 }
 178
 179 static void iblock_dev_call_rcu(struct rcu_head *p)
 180 {
 181         struct se_device *dev = container_of(p, struct se_device, rcu_head);
 182         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 183
 184         kfree(ib_dev->ibd_plug);
 185         kfree(ib_dev);
 186 }
 187
 188 static void iblock_free_device(struct se_device *dev)
 189 {
 190         call_rcu(&dev->rcu_head, iblock_dev_call_rcu);
 191 }
 192
 193 static void iblock_destroy_device(struct se_device *dev)
 194 {
 195         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 196
 197         if (ib_dev->ibd_bd != NULL)
 198                 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
 199         bioset_exit(&ib_dev->ibd_bio_set);
 200 }
 201
 202 static struct se_dev_plug *iblock_plug_device(struct se_device *se_dev)
 203 {
 204         struct iblock_dev *ib_dev = IBLOCK_DEV(se_dev);
 205         struct iblock_dev_plug *ib_dev_plug;
 206
 207         /*
 208          * Each se_device has a per cpu work this can be run from. We
 209          * shouldn't have multiple threads on the same cpu calling this
 210          * at the same time.
 211          */
 212         ib_dev_plug = &ib_dev->ibd_plug[raw_smp_processor_id()];
 213         if (test_and_set_bit(IBD_PLUGF_PLUGGED, &ib_dev_plug->flags))
 214                 return NULL;
 215
 216         blk_start_plug(&ib_dev_plug->blk_plug);
 217         return &ib_dev_plug->se_plug;
 218 }
 219
 220 static void iblock_unplug_device(struct se_dev_plug *se_plug)
 221 {
 222         struct iblock_dev_plug *ib_dev_plug = container_of(se_plug,
 223                                         struct iblock_dev_plug, se_plug);
 224
 225         blk_finish_plug(&ib_dev_plug->blk_plug);
 226         clear_bit(IBD_PLUGF_PLUGGED, &ib_dev_plug->flags);
 227 }
 228
 229 static unsigned long long iblock_emulate_read_cap_with_block_size(
 230         struct se_device *dev,
 231         struct block_device *bd,
 232         struct request_queue *q)
 233 {
 234         u32 block_size = bdev_logical_block_size(bd);
 235         unsigned long long blocks_long =
 236                 div_u64(bdev_nr_bytes(bd), block_size) - 1;
 237
 238         if (block_size == dev->dev_attrib.block_size)
 239                 return blocks_long;
 240
 241         switch (block_size) {
 242         case 4096:
 243                 switch (dev->dev_attrib.block_size) {
 244                 case 2048:
 245                         blocks_long <<= 1;
 246                         break;
 247                 case 1024:
 248                         blocks_long <<= 2;
 249                         break;
 250                 case 512:
 251                         blocks_long <<= 3;
 252                         break;
 253                 default:
 254                         break;
 255                 }
 256                 break;
 257         case 2048:
 258                 switch (dev->dev_attrib.block_size) {
 259                 case 4096:
 260                         blocks_long >>= 1;
 261                         break;
 262                 case 1024:
 263                         blocks_long <<= 1;
 264                         break;
 265                 case 512:
 266                         blocks_long <<= 2;
 267                         break;
 268                 default:
 269                         break;
 270                 }
 271                 break;
 272         case 1024:
 273                 switch (dev->dev_attrib.block_size) {
 274                 case 4096:
 275                         blocks_long >>= 2;
 276                         break;
 277                 case 2048:
 278                         blocks_long >>= 1;
 279                         break;
 280                 case 512:
 281                         blocks_long <<= 1;
 282                         break;
 283                 default:
 284                         break;
 285                 }
 286                 break;
 287         case 512:
 288                 switch (dev->dev_attrib.block_size) {
 289                 case 4096:
 290                         blocks_long >>= 3;
 291                         break;
 292                 case 2048:
 293                         blocks_long >>= 2;
 294                         break;
 295                 case 1024:
 296                         blocks_long >>= 1;
 297                         break;
 298                 default:
 299                         break;
 300                 }
 301                 break;
 302         default:
 303                 break;
 304         }
 305
 306         return blocks_long;
 307 }
 308
 309 static void iblock_complete_cmd(struct se_cmd *cmd)
 310 {
 311         struct iblock_req *ibr = cmd->priv;
 312         u8 status;
 313
 314         if (!refcount_dec_and_test(&ibr->pending))
 315                 return;
 316
 317         if (atomic_read(&ibr->ib_bio_err_cnt))
 318                 status = SAM_STAT_CHECK_CONDITION;
 319         else
 320                 status = SAM_STAT_GOOD;
 321
 322         target_complete_cmd(cmd, status);
 323         kfree(ibr);
 324 }
 325
 326 static void iblock_bio_done(struct bio *bio)
 327 {
 328         struct se_cmd *cmd = bio->bi_private;
 329         struct iblock_req *ibr = cmd->priv;
 330
 331         if (bio->bi_status) {
 332                 pr_err("bio error: %p,  err: %d\n", bio, bio->bi_status);
 333                 /*
 334                  * Bump the ib_bio_err_cnt and release bio.
 335                  */
 336                 atomic_inc(&ibr->ib_bio_err_cnt);
 337                 smp_mb__after_atomic();
 338         }
 339
 340         bio_put(bio);
 341
 342         iblock_complete_cmd(cmd);
 343 }
 344
 345 static struct bio *iblock_get_bio(struct se_cmd *cmd, sector_t lba, u32 sg_num,
 346                                   unsigned int opf)
 347 {
 348         struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
 349         struct bio *bio;
 350
 351         /*
 352          * Only allocate as many vector entries as the bio code allows us to,
 353          * we'll loop later on until we have handled the whole request.
 354          */
 355         bio = bio_alloc_bioset(ib_dev->ibd_bd, bio_max_segs(sg_num), opf,
 356                                GFP_NOIO, &ib_dev->ibd_bio_set);
 357         if (!bio) {
 358                 pr_err("Unable to allocate memory for bio\n");
 359                 return NULL;
 360         }
 361
 362         bio->bi_private = cmd;
 363         bio->bi_end_io = &iblock_bio_done;
 364         bio->bi_iter.bi_sector = lba;
 365
 366         return bio;
 367 }
 368
 369 static void iblock_submit_bios(struct bio_list *list)
 370 {
 371         struct blk_plug plug;
 372         struct bio *bio;
 373         /*
 374          * The block layer handles nested plugs, so just plug/unplug to handle
 375          * fabric drivers that didn't support batching and multi bio cmds.
 376          */
 377         blk_start_plug(&plug);
 378         while ((bio = bio_list_pop(list)))
 379                 submit_bio(bio);
 380         blk_finish_plug(&plug);
 381 }
 382
 383 static void iblock_end_io_flush(struct bio *bio)
 384 {
 385         struct se_cmd *cmd = bio->bi_private;
 386
 387         if (bio->bi_status)
 388                 pr_err("IBLOCK: cache flush failed: %d\n", bio->bi_status);
 389
 390         if (cmd) {
 391                 if (bio->bi_status)
 392                         target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
 393                 else
 394                         target_complete_cmd(cmd, SAM_STAT_GOOD);
 395         }
 396
 397         bio_put(bio);
 398 }
 399
 400 /*
 401  * Implement SYCHRONIZE CACHE.  Note that we can't handle lba ranges and must
 402  * always flush the whole cache.
 403  */
 404 static sense_reason_t
 405 iblock_execute_sync_cache(struct se_cmd *cmd)
 406 {
 407         struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
 408         int immed = (cmd->t_task_cdb[1] & 0x2);
 409         struct bio *bio;
 410
 411         /*
 412          * If the Immediate bit is set, queue up the GOOD response
 413          * for this SYNCHRONIZE_CACHE op.
 414          */
 415         if (immed)
 416                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 417
 418         bio = bio_alloc(ib_dev->ibd_bd, 0, REQ_OP_WRITE | REQ_PREFLUSH,
 419                         GFP_KERNEL);
 420         bio->bi_end_io = iblock_end_io_flush;
 421         if (!immed)
 422                 bio->bi_private = cmd;
 423         submit_bio(bio);
 424         return 0;
 425 }
 426
 427 static sense_reason_t
 428 iblock_execute_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
 429 {
 430         struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
 431         struct se_device *dev = cmd->se_dev;
 432         int ret;
 433
 434         ret = blkdev_issue_discard(bdev,
 435                                    target_to_linux_sector(dev, lba),
 436                                    target_to_linux_sector(dev,  nolb),
 437                                    GFP_KERNEL);
 438         if (ret < 0) {
 439                 pr_err("blkdev_issue_discard() failed: %d\n", ret);
 440                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 441         }
 442
 443         return 0;
 444 }
 445
 446 static sense_reason_t
 447 iblock_execute_zero_out(struct block_device *bdev, struct se_cmd *cmd)
 448 {
 449         struct se_device *dev = cmd->se_dev;
 450         struct scatterlist *sg = &cmd->t_data_sg[0];
 451         unsigned char *buf, *not_zero;
 452         int ret;
 453
 454         buf = kmap(sg_page(sg)) + sg->offset;
 455         if (!buf)
 456                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 457         /*
 458          * Fall back to block_execute_write_same() slow-path if
 459          * incoming WRITE_SAME payload does not contain zeros.
 460          */
 461         not_zero = memchr_inv(buf, 0x00, cmd->data_length);
 462         kunmap(sg_page(sg));
 463
 464         if (not_zero)
 465                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 466
 467         ret = blkdev_issue_zeroout(bdev,
 468                                 target_to_linux_sector(dev, cmd->t_task_lba),
 469                                 target_to_linux_sector(dev,
 470                                         sbc_get_write_same_sectors(cmd)),
 471                                 GFP_KERNEL, BLKDEV_ZERO_NOUNMAP);
 472         if (ret)
 473                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 474
 475         target_complete_cmd(cmd, SAM_STAT_GOOD);
 476         return 0;
 477 }
 478
 479 static sense_reason_t
 480 iblock_execute_write_same(struct se_cmd *cmd)
 481 {
 482         struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
 483         struct iblock_req *ibr;
 484         struct scatterlist *sg;
 485         struct bio *bio;
 486         struct bio_list list;
 487         struct se_device *dev = cmd->se_dev;
 488         sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba);
 489         sector_t sectors = target_to_linux_sector(dev,
 490                                         sbc_get_write_same_sectors(cmd));
 491
 492         if (cmd->prot_op) {
 493                 pr_err("WRITE_SAME: Protection information with IBLOCK"
 494                        " backends not supported\n");
 495                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 496         }
 497
 498         if (!cmd->t_data_nents)
 499                 return TCM_INVALID_CDB_FIELD;
 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                 /*
 735                  * Force writethrough using REQ_FUA if a volatile write cache
 736                  * is not enabled, or if initiator set the Force Unit Access bit.
 737                  */
 738                 opf = REQ_OP_WRITE;
 739                 miter_dir = SG_MITER_TO_SG;
 740                 if (bdev_fua(ib_dev->ibd_bd)) {
 741                         if (cmd->se_cmd_flags & SCF_FUA)
 742                                 opf |= REQ_FUA;
 743                         else if (!bdev_write_cache(ib_dev->ibd_bd))
 744                                 opf |= REQ_FUA;
 745                 }
 746         } else {
 747                 opf = REQ_OP_READ;
 748                 miter_dir = SG_MITER_FROM_SG;
 749         }
 750
 751         ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
 752         if (!ibr)
 753                 goto fail;
 754         cmd->priv = ibr;
 755
 756         if (!sgl_nents) {
 757                 refcount_set(&ibr->pending, 1);
 758                 iblock_complete_cmd(cmd);
 759                 return 0;
 760         }
 761
 762         bio = iblock_get_bio(cmd, block_lba, sgl_nents, opf);
 763         if (!bio)
 764                 goto fail_free_ibr;
 765
 766         bio_list_init(&list);
 767         bio_list_add(&list, bio);
 768
 769         refcount_set(&ibr->pending, 2);
 770         bio_cnt = 1;
 771
 772         if (cmd->prot_type && dev->dev_attrib.pi_prot_type)
 773                 sg_miter_start(&prot_miter, cmd->t_prot_sg, cmd->t_prot_nents,
 774                                miter_dir);
 775
 776         for_each_sg(sgl, sg, sgl_nents, i) {
 777                 /*
 778                  * XXX: if the length the device accepts is shorter than the
 779                  *      length of the S/G list entry this will cause and
 780                  *      endless loop.  Better hope no driver uses huge pages.
 781                  */
 782                 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
 783                                 != sg->length) {
 784                         if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
 785                                 rc = iblock_alloc_bip(cmd, bio, &prot_miter);
 786                                 if (rc)
 787                                         goto fail_put_bios;
 788                         }
 789
 790                         if (bio_cnt >= IBLOCK_MAX_BIO_PER_TASK) {
 791                                 iblock_submit_bios(&list);
 792                                 bio_cnt = 0;
 793                         }
 794
 795                         bio = iblock_get_bio(cmd, block_lba, sg_num, opf);
 796                         if (!bio)
 797                                 goto fail_put_bios;
 798
 799                         refcount_inc(&ibr->pending);
 800                         bio_list_add(&list, bio);
 801                         bio_cnt++;
 802                 }
 803
 804                 /* Always in 512 byte units for Linux/Block */
 805                 block_lba += sg->length >> SECTOR_SHIFT;
 806                 sg_num--;
 807         }
 808
 809         if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
 810                 rc = iblock_alloc_bip(cmd, bio, &prot_miter);
 811                 if (rc)
 812                         goto fail_put_bios;
 813         }
 814
 815         iblock_submit_bios(&list);
 816         iblock_complete_cmd(cmd);
 817         return 0;
 818
 819 fail_put_bios:
 820         while ((bio = bio_list_pop(&list)))
 821                 bio_put(bio);
 822 fail_free_ibr:
 823         kfree(ibr);
 824 fail:
 825         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 826 }
 827
 828 static sector_t iblock_get_blocks(struct se_device *dev)
 829 {
 830         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 831         struct block_device *bd = ib_dev->ibd_bd;
 832         struct request_queue *q = bdev_get_queue(bd);
 833
 834         return iblock_emulate_read_cap_with_block_size(dev, bd, q);
 835 }
 836
 837 static sector_t iblock_get_alignment_offset_lbas(struct se_device *dev)
 838 {
 839         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 840         struct block_device *bd = ib_dev->ibd_bd;
 841         int ret;
 842
 843         ret = bdev_alignment_offset(bd);
 844         if (ret == -1)
 845                 return 0;
 846
 847         /* convert offset-bytes to offset-lbas */
 848         return ret / bdev_logical_block_size(bd);
 849 }
 850
 851 static unsigned int iblock_get_lbppbe(struct se_device *dev)
 852 {
 853         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 854         struct block_device *bd = ib_dev->ibd_bd;
 855         unsigned int logs_per_phys =
 856                 bdev_physical_block_size(bd) / bdev_logical_block_size(bd);
 857
 858         return ilog2(logs_per_phys);
 859 }
 860
 861 static unsigned int iblock_get_io_min(struct se_device *dev)
 862 {
 863         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 864         struct block_device *bd = ib_dev->ibd_bd;
 865
 866         return bdev_io_min(bd);
 867 }
 868
 869 static unsigned int iblock_get_io_opt(struct se_device *dev)
 870 {
 871         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 872         struct block_device *bd = ib_dev->ibd_bd;
 873
 874         return bdev_io_opt(bd);
 875 }
 876
 877 static struct sbc_ops iblock_sbc_ops = {
 878         .execute_rw             = iblock_execute_rw,
 879         .execute_sync_cache     = iblock_execute_sync_cache,
 880         .execute_write_same     = iblock_execute_write_same,
 881         .execute_unmap          = iblock_execute_unmap,
 882 };
 883
 884 static sense_reason_t
 885 iblock_parse_cdb(struct se_cmd *cmd)
 886 {
 887         return sbc_parse_cdb(cmd, &iblock_sbc_ops);
 888 }
 889
 890 static bool iblock_get_write_cache(struct se_device *dev)
 891 {
 892         return bdev_write_cache(IBLOCK_DEV(dev)->ibd_bd);
 893 }
 894
 895 static const struct target_backend_ops iblock_ops = {
 896         .name                   = "iblock",
 897         .inquiry_prod           = "IBLOCK",
 898         .inquiry_rev            = IBLOCK_VERSION,
 899         .owner                  = THIS_MODULE,
 900         .attach_hba             = iblock_attach_hba,
 901         .detach_hba             = iblock_detach_hba,
 902         .alloc_device           = iblock_alloc_device,
 903         .configure_device       = iblock_configure_device,
 904         .destroy_device         = iblock_destroy_device,
 905         .free_device            = iblock_free_device,
 906         .plug_device            = iblock_plug_device,
 907         .unplug_device          = iblock_unplug_device,
 908         .parse_cdb              = iblock_parse_cdb,
 909         .set_configfs_dev_params = iblock_set_configfs_dev_params,
 910         .show_configfs_dev_params = iblock_show_configfs_dev_params,
 911         .get_device_type        = sbc_get_device_type,
 912         .get_blocks             = iblock_get_blocks,
 913         .get_alignment_offset_lbas = iblock_get_alignment_offset_lbas,
 914         .get_lbppbe             = iblock_get_lbppbe,
 915         .get_io_min             = iblock_get_io_min,
 916         .get_io_opt             = iblock_get_io_opt,
 917         .get_write_cache        = iblock_get_write_cache,
 918         .tb_dev_attrib_attrs    = sbc_attrib_attrs,
 919 };
 920
 921 static int __init iblock_module_init(void)
 922 {
 923         return transport_backend_register(&iblock_ops);
 924 }
 925
 926 static void __exit iblock_module_exit(void)
 927 {
 928         target_backend_unregister(&iblock_ops);
 929 }
 930
 931 MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin");
 932 MODULE_AUTHOR("nab@Linux-iSCSI.org");
 933 MODULE_LICENSE("GPL");
 934
 935 module_init(iblock_module_init);
 936 module_exit(iblock_module_exit);