linux/drivers/target/target_core_iblock.c
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   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
  36static inline struct iblock_dev *IBLOCK_DEV(struct se_device *dev)
  37{
  38        return container_of(dev, struct iblock_dev, dev);
  39}
  40
  41
  42static 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
  50static void iblock_detach_hba(struct se_hba *hba)
  51{
  52}
  53
  54static 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
  69static 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
 161out_blkdev_put:
 162        blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
 163out_free_bioset:
 164        bioset_exit(&ib_dev->ibd_bio_set);
 165out:
 166        return ret;
 167}
 168
 169static 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
 177static void iblock_free_device(struct se_device *dev)
 178{
 179        call_rcu(&dev->rcu_head, iblock_dev_call_rcu);
 180}
 181
 182static 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
 191static 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
 270static 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
 287static 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
 306static struct bio *
 307iblock_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
 335static 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
 346static 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 */
 367static sense_reason_t
 368iblock_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
 391static sense_reason_t
 392iblock_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
 410static sense_reason_t
 411iblock_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, false);
 436        if (ret)
 437                return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 438
 439        target_complete_cmd(cmd, GOOD);
 440        return 0;
 441}
 442
 443static sense_reason_t
 444iblock_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
 511fail_put_bios:
 512        while ((bio = bio_list_pop(&list)))
 513                bio_put(bio);
 514fail_free_ibr:
 515        kfree(ibr);
 516fail:
 517        return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 518}
 519
 520enum {
 521        Opt_udev_path, Opt_readonly, Opt_force, Opt_err
 522};
 523
 524static 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
 531static 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
 591out:
 592        kfree(orig);
 593        return (!ret) ? count : ret;
 594}
 595
 596static 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), (!bd->bd_contains) ?
 615                        "" : (bd->bd_holder == ib_dev) ?
 616                        "CLAIMED: IBLOCK" : "CLAIMED: OS");
 617        } else {
 618                bl += sprintf(b + bl, "Major: 0 Minor: 0\n");
 619        }
 620
 621        return bl;
 622}
 623
 624static int
 625iblock_alloc_bip(struct se_cmd *cmd, struct bio *bio,
 626                 struct sg_mapping_iter *miter)
 627{
 628        struct se_device *dev = cmd->se_dev;
 629        struct blk_integrity *bi;
 630        struct bio_integrity_payload *bip;
 631        struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 632        int rc;
 633        size_t resid, len;
 634
 635        bi = bdev_get_integrity(ib_dev->ibd_bd);
 636        if (!bi) {
 637                pr_err("Unable to locate bio_integrity\n");
 638                return -ENODEV;
 639        }
 640
 641        bip = bio_integrity_alloc(bio, GFP_NOIO,
 642                        min_t(unsigned int, cmd->t_prot_nents, BIO_MAX_PAGES));
 643        if (IS_ERR(bip)) {
 644                pr_err("Unable to allocate bio_integrity_payload\n");
 645                return PTR_ERR(bip);
 646        }
 647
 648        bip->bip_iter.bi_size = bio_integrity_bytes(bi, bio_sectors(bio));
 649        /* virtual start sector must be in integrity interval units */
 650        bip_set_seed(bip, bio->bi_iter.bi_sector >>
 651                                  (bi->interval_exp - SECTOR_SHIFT));
 652
 653        pr_debug("IBLOCK BIP Size: %u Sector: %llu\n", bip->bip_iter.bi_size,
 654                 (unsigned long long)bip->bip_iter.bi_sector);
 655
 656        resid = bip->bip_iter.bi_size;
 657        while (resid > 0 && sg_miter_next(miter)) {
 658
 659                len = min_t(size_t, miter->length, resid);
 660                rc = bio_integrity_add_page(bio, miter->page, len,
 661                                            offset_in_page(miter->addr));
 662                if (rc != len) {
 663                        pr_err("bio_integrity_add_page() failed; %d\n", rc);
 664                        sg_miter_stop(miter);
 665                        return -ENOMEM;
 666                }
 667
 668                pr_debug("Added bio integrity page: %p length: %zu offset: %lu\n",
 669                          miter->page, len, offset_in_page(miter->addr));
 670
 671                resid -= len;
 672                if (len < miter->length)
 673                        miter->consumed -= miter->length - len;
 674        }
 675        sg_miter_stop(miter);
 676
 677        return 0;
 678}
 679
 680static sense_reason_t
 681iblock_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 682                  enum dma_data_direction data_direction)
 683{
 684        struct se_device *dev = cmd->se_dev;
 685        sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba);
 686        struct iblock_req *ibr;
 687        struct bio *bio;
 688        struct bio_list list;
 689        struct scatterlist *sg;
 690        u32 sg_num = sgl_nents;
 691        unsigned bio_cnt;
 692        int i, rc, op, op_flags = 0;
 693        struct sg_mapping_iter prot_miter;
 694
 695        if (data_direction == DMA_TO_DEVICE) {
 696                struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 697                struct request_queue *q = bdev_get_queue(ib_dev->ibd_bd);
 698                /*
 699                 * Force writethrough using REQ_FUA if a volatile write cache
 700                 * is not enabled, or if initiator set the Force Unit Access bit.
 701                 */
 702                op = REQ_OP_WRITE;
 703                if (test_bit(QUEUE_FLAG_FUA, &q->queue_flags)) {
 704                        if (cmd->se_cmd_flags & SCF_FUA)
 705                                op_flags = REQ_FUA;
 706                        else if (!test_bit(QUEUE_FLAG_WC, &q->queue_flags))
 707                                op_flags = REQ_FUA;
 708                }
 709        } else {
 710                op = REQ_OP_READ;
 711        }
 712
 713        ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
 714        if (!ibr)
 715                goto fail;
 716        cmd->priv = ibr;
 717
 718        if (!sgl_nents) {
 719                refcount_set(&ibr->pending, 1);
 720                iblock_complete_cmd(cmd);
 721                return 0;
 722        }
 723
 724        bio = iblock_get_bio(cmd, block_lba, sgl_nents, op, op_flags);
 725        if (!bio)
 726                goto fail_free_ibr;
 727
 728        bio_list_init(&list);
 729        bio_list_add(&list, bio);
 730
 731        refcount_set(&ibr->pending, 2);
 732        bio_cnt = 1;
 733
 734        if (cmd->prot_type && dev->dev_attrib.pi_prot_type)
 735                sg_miter_start(&prot_miter, cmd->t_prot_sg, cmd->t_prot_nents,
 736                               op == REQ_OP_READ ? SG_MITER_FROM_SG :
 737                                                   SG_MITER_TO_SG);
 738
 739        for_each_sg(sgl, sg, sgl_nents, i) {
 740                /*
 741                 * XXX: if the length the device accepts is shorter than the
 742                 *      length of the S/G list entry this will cause and
 743                 *      endless loop.  Better hope no driver uses huge pages.
 744                 */
 745                while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
 746                                != sg->length) {
 747                        if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
 748                                rc = iblock_alloc_bip(cmd, bio, &prot_miter);
 749                                if (rc)
 750                                        goto fail_put_bios;
 751                        }
 752
 753                        if (bio_cnt >= IBLOCK_MAX_BIO_PER_TASK) {
 754                                iblock_submit_bios(&list);
 755                                bio_cnt = 0;
 756                        }
 757
 758                        bio = iblock_get_bio(cmd, block_lba, sg_num, op,
 759                                             op_flags);
 760                        if (!bio)
 761                                goto fail_put_bios;
 762
 763                        refcount_inc(&ibr->pending);
 764                        bio_list_add(&list, bio);
 765                        bio_cnt++;
 766                }
 767
 768                /* Always in 512 byte units for Linux/Block */
 769                block_lba += sg->length >> SECTOR_SHIFT;
 770                sg_num--;
 771        }
 772
 773        if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
 774                rc = iblock_alloc_bip(cmd, bio, &prot_miter);
 775                if (rc)
 776                        goto fail_put_bios;
 777        }
 778
 779        iblock_submit_bios(&list);
 780        iblock_complete_cmd(cmd);
 781        return 0;
 782
 783fail_put_bios:
 784        while ((bio = bio_list_pop(&list)))
 785                bio_put(bio);
 786fail_free_ibr:
 787        kfree(ibr);
 788fail:
 789        return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 790}
 791
 792static sector_t iblock_get_blocks(struct se_device *dev)
 793{
 794        struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 795        struct block_device *bd = ib_dev->ibd_bd;
 796        struct request_queue *q = bdev_get_queue(bd);
 797
 798        return iblock_emulate_read_cap_with_block_size(dev, bd, q);
 799}
 800
 801static sector_t iblock_get_alignment_offset_lbas(struct se_device *dev)
 802{
 803        struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 804        struct block_device *bd = ib_dev->ibd_bd;
 805        int ret;
 806
 807        ret = bdev_alignment_offset(bd);
 808        if (ret == -1)
 809                return 0;
 810
 811        /* convert offset-bytes to offset-lbas */
 812        return ret / bdev_logical_block_size(bd);
 813}
 814
 815static unsigned int iblock_get_lbppbe(struct se_device *dev)
 816{
 817        struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 818        struct block_device *bd = ib_dev->ibd_bd;
 819        int logs_per_phys = bdev_physical_block_size(bd) / bdev_logical_block_size(bd);
 820
 821        return ilog2(logs_per_phys);
 822}
 823
 824static unsigned int iblock_get_io_min(struct se_device *dev)
 825{
 826        struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 827        struct block_device *bd = ib_dev->ibd_bd;
 828
 829        return bdev_io_min(bd);
 830}
 831
 832static unsigned int iblock_get_io_opt(struct se_device *dev)
 833{
 834        struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 835        struct block_device *bd = ib_dev->ibd_bd;
 836
 837        return bdev_io_opt(bd);
 838}
 839
 840static struct sbc_ops iblock_sbc_ops = {
 841        .execute_rw             = iblock_execute_rw,
 842        .execute_sync_cache     = iblock_execute_sync_cache,
 843        .execute_write_same     = iblock_execute_write_same,
 844        .execute_unmap          = iblock_execute_unmap,
 845};
 846
 847static sense_reason_t
 848iblock_parse_cdb(struct se_cmd *cmd)
 849{
 850        return sbc_parse_cdb(cmd, &iblock_sbc_ops);
 851}
 852
 853static bool iblock_get_write_cache(struct se_device *dev)
 854{
 855        struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 856        struct block_device *bd = ib_dev->ibd_bd;
 857        struct request_queue *q = bdev_get_queue(bd);
 858
 859        return test_bit(QUEUE_FLAG_WC, &q->queue_flags);
 860}
 861
 862static const struct target_backend_ops iblock_ops = {
 863        .name                   = "iblock",
 864        .inquiry_prod           = "IBLOCK",
 865        .inquiry_rev            = IBLOCK_VERSION,
 866        .owner                  = THIS_MODULE,
 867        .attach_hba             = iblock_attach_hba,
 868        .detach_hba             = iblock_detach_hba,
 869        .alloc_device           = iblock_alloc_device,
 870        .configure_device       = iblock_configure_device,
 871        .destroy_device         = iblock_destroy_device,
 872        .free_device            = iblock_free_device,
 873        .parse_cdb              = iblock_parse_cdb,
 874        .set_configfs_dev_params = iblock_set_configfs_dev_params,
 875        .show_configfs_dev_params = iblock_show_configfs_dev_params,
 876        .get_device_type        = sbc_get_device_type,
 877        .get_blocks             = iblock_get_blocks,
 878        .get_alignment_offset_lbas = iblock_get_alignment_offset_lbas,
 879        .get_lbppbe             = iblock_get_lbppbe,
 880        .get_io_min             = iblock_get_io_min,
 881        .get_io_opt             = iblock_get_io_opt,
 882        .get_write_cache        = iblock_get_write_cache,
 883        .tb_dev_attrib_attrs    = sbc_attrib_attrs,
 884};
 885
 886static int __init iblock_module_init(void)
 887{
 888        return transport_backend_register(&iblock_ops);
 889}
 890
 891static void __exit iblock_module_exit(void)
 892{
 893        target_backend_unregister(&iblock_ops);
 894}
 895
 896MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin");
 897MODULE_AUTHOR("nab@Linux-iSCSI.org");
 898MODULE_LICENSE("GPL");
 899
 900module_init(iblock_module_init);
 901module_exit(iblock_module_exit);
 902