linux/drivers/target/target_core_iblock.c
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   1/*******************************************************************************
   2 * Filename:  target_core_iblock.c
   3 *
   4 * This file contains the Storage Engine  <-> Linux BlockIO transport
   5 * specific functions.
   6 *
   7 * (c) Copyright 2003-2012 RisingTide Systems LLC.
   8 *
   9 * Nicholas A. Bellinger <nab@kernel.org>
  10 *
  11 * This program is free software; you can redistribute it and/or modify
  12 * it under the terms of the GNU General Public License as published by
  13 * the Free Software Foundation; either version 2 of the License, or
  14 * (at your option) any later version.
  15 *
  16 * This program is distributed in the hope that it will be useful,
  17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 * GNU General Public License for more details.
  20 *
  21 * You should have received a copy of the GNU General Public License
  22 * along with this program; if not, write to the Free Software
  23 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  24 *
  25 ******************************************************************************/
  26
  27#include <linux/string.h>
  28#include <linux/parser.h>
  29#include <linux/timer.h>
  30#include <linux/fs.h>
  31#include <linux/blkdev.h>
  32#include <linux/slab.h>
  33#include <linux/spinlock.h>
  34#include <linux/bio.h>
  35#include <linux/genhd.h>
  36#include <linux/file.h>
  37#include <linux/module.h>
  38#include <scsi/scsi.h>
  39#include <scsi/scsi_host.h>
  40#include <asm/unaligned.h>
  41
  42#include <target/target_core_base.h>
  43#include <target/target_core_backend.h>
  44
  45#include "target_core_iblock.h"
  46
  47#define IBLOCK_MAX_BIO_PER_TASK  32     /* max # of bios to submit at a time */
  48#define IBLOCK_BIO_POOL_SIZE    128
  49
  50static inline struct iblock_dev *IBLOCK_DEV(struct se_device *dev)
  51{
  52        return container_of(dev, struct iblock_dev, dev);
  53}
  54
  55
  56static struct se_subsystem_api iblock_template;
  57
  58/*      iblock_attach_hba(): (Part of se_subsystem_api_t template)
  59 *
  60 *
  61 */
  62static int iblock_attach_hba(struct se_hba *hba, u32 host_id)
  63{
  64        pr_debug("CORE_HBA[%d] - TCM iBlock HBA Driver %s on"
  65                " Generic Target Core Stack %s\n", hba->hba_id,
  66                IBLOCK_VERSION, TARGET_CORE_MOD_VERSION);
  67        return 0;
  68}
  69
  70static void iblock_detach_hba(struct se_hba *hba)
  71{
  72}
  73
  74static struct se_device *iblock_alloc_device(struct se_hba *hba, const char *name)
  75{
  76        struct iblock_dev *ib_dev = NULL;
  77
  78        ib_dev = kzalloc(sizeof(struct iblock_dev), GFP_KERNEL);
  79        if (!ib_dev) {
  80                pr_err("Unable to allocate struct iblock_dev\n");
  81                return NULL;
  82        }
  83
  84        pr_debug( "IBLOCK: Allocated ib_dev for %s\n", name);
  85
  86        return &ib_dev->dev;
  87}
  88
  89static int iblock_configure_device(struct se_device *dev)
  90{
  91        struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
  92        struct request_queue *q;
  93        struct block_device *bd = NULL;
  94        fmode_t mode;
  95        int ret = -ENOMEM;
  96
  97        if (!(ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)) {
  98                pr_err("Missing udev_path= parameters for IBLOCK\n");
  99                return -EINVAL;
 100        }
 101
 102        ib_dev->ibd_bio_set = bioset_create(IBLOCK_BIO_POOL_SIZE, 0);
 103        if (!ib_dev->ibd_bio_set) {
 104                pr_err("IBLOCK: Unable to create bioset\n");
 105                goto out;
 106        }
 107
 108        pr_debug( "IBLOCK: Claiming struct block_device: %s\n",
 109                        ib_dev->ibd_udev_path);
 110
 111        mode = FMODE_READ|FMODE_EXCL;
 112        if (!ib_dev->ibd_readonly)
 113                mode |= FMODE_WRITE;
 114
 115        bd = blkdev_get_by_path(ib_dev->ibd_udev_path, mode, ib_dev);
 116        if (IS_ERR(bd)) {
 117                ret = PTR_ERR(bd);
 118                goto out_free_bioset;
 119        }
 120        ib_dev->ibd_bd = bd;
 121
 122        q = bdev_get_queue(bd);
 123
 124        dev->dev_attrib.hw_block_size = bdev_logical_block_size(bd);
 125        dev->dev_attrib.hw_max_sectors = UINT_MAX;
 126        dev->dev_attrib.hw_queue_depth = q->nr_requests;
 127
 128        /*
 129         * Check if the underlying struct block_device request_queue supports
 130         * the QUEUE_FLAG_DISCARD bit for UNMAP/WRITE_SAME in SCSI + TRIM
 131         * in ATA and we need to set TPE=1
 132         */
 133        if (blk_queue_discard(q)) {
 134                dev->dev_attrib.max_unmap_lba_count =
 135                                q->limits.max_discard_sectors;
 136
 137                /*
 138                 * Currently hardcoded to 1 in Linux/SCSI code..
 139                 */
 140                dev->dev_attrib.max_unmap_block_desc_count = 1;
 141                dev->dev_attrib.unmap_granularity =
 142                                q->limits.discard_granularity >> 9;
 143                dev->dev_attrib.unmap_granularity_alignment =
 144                                q->limits.discard_alignment;
 145
 146                pr_debug("IBLOCK: BLOCK Discard support available,"
 147                                " disabled by default\n");
 148        }
 149        /*
 150         * Enable write same emulation for IBLOCK and use 0xFFFF as
 151         * the smaller WRITE_SAME(10) only has a two-byte block count.
 152         */
 153        dev->dev_attrib.max_write_same_len = 0xFFFF;
 154
 155        if (blk_queue_nonrot(q))
 156                dev->dev_attrib.is_nonrot = 1;
 157        return 0;
 158
 159out_free_bioset:
 160        bioset_free(ib_dev->ibd_bio_set);
 161        ib_dev->ibd_bio_set = NULL;
 162out:
 163        return ret;
 164}
 165
 166static void iblock_free_device(struct se_device *dev)
 167{
 168        struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 169
 170        if (ib_dev->ibd_bd != NULL)
 171                blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
 172        if (ib_dev->ibd_bio_set != NULL)
 173                bioset_free(ib_dev->ibd_bio_set);
 174        kfree(ib_dev);
 175}
 176
 177static unsigned long long iblock_emulate_read_cap_with_block_size(
 178        struct se_device *dev,
 179        struct block_device *bd,
 180        struct request_queue *q)
 181{
 182        unsigned long long blocks_long = (div_u64(i_size_read(bd->bd_inode),
 183                                        bdev_logical_block_size(bd)) - 1);
 184        u32 block_size = bdev_logical_block_size(bd);
 185
 186        if (block_size == dev->dev_attrib.block_size)
 187                return blocks_long;
 188
 189        switch (block_size) {
 190        case 4096:
 191                switch (dev->dev_attrib.block_size) {
 192                case 2048:
 193                        blocks_long <<= 1;
 194                        break;
 195                case 1024:
 196                        blocks_long <<= 2;
 197                        break;
 198                case 512:
 199                        blocks_long <<= 3;
 200                default:
 201                        break;
 202                }
 203                break;
 204        case 2048:
 205                switch (dev->dev_attrib.block_size) {
 206                case 4096:
 207                        blocks_long >>= 1;
 208                        break;
 209                case 1024:
 210                        blocks_long <<= 1;
 211                        break;
 212                case 512:
 213                        blocks_long <<= 2;
 214                        break;
 215                default:
 216                        break;
 217                }
 218                break;
 219        case 1024:
 220                switch (dev->dev_attrib.block_size) {
 221                case 4096:
 222                        blocks_long >>= 2;
 223                        break;
 224                case 2048:
 225                        blocks_long >>= 1;
 226                        break;
 227                case 512:
 228                        blocks_long <<= 1;
 229                        break;
 230                default:
 231                        break;
 232                }
 233                break;
 234        case 512:
 235                switch (dev->dev_attrib.block_size) {
 236                case 4096:
 237                        blocks_long >>= 3;
 238                        break;
 239                case 2048:
 240                        blocks_long >>= 2;
 241                        break;
 242                case 1024:
 243                        blocks_long >>= 1;
 244                        break;
 245                default:
 246                        break;
 247                }
 248                break;
 249        default:
 250                break;
 251        }
 252
 253        return blocks_long;
 254}
 255
 256static void iblock_complete_cmd(struct se_cmd *cmd)
 257{
 258        struct iblock_req *ibr = cmd->priv;
 259        u8 status;
 260
 261        if (!atomic_dec_and_test(&ibr->pending))
 262                return;
 263
 264        if (atomic_read(&ibr->ib_bio_err_cnt))
 265                status = SAM_STAT_CHECK_CONDITION;
 266        else
 267                status = SAM_STAT_GOOD;
 268
 269        target_complete_cmd(cmd, status);
 270        kfree(ibr);
 271}
 272
 273static void iblock_bio_done(struct bio *bio, int err)
 274{
 275        struct se_cmd *cmd = bio->bi_private;
 276        struct iblock_req *ibr = cmd->priv;
 277
 278        /*
 279         * Set -EIO if !BIO_UPTODATE and the passed is still err=0
 280         */
 281        if (!test_bit(BIO_UPTODATE, &bio->bi_flags) && !err)
 282                err = -EIO;
 283
 284        if (err != 0) {
 285                pr_err("test_bit(BIO_UPTODATE) failed for bio: %p,"
 286                        " err: %d\n", bio, err);
 287                /*
 288                 * Bump the ib_bio_err_cnt and release bio.
 289                 */
 290                atomic_inc(&ibr->ib_bio_err_cnt);
 291                smp_mb__after_atomic_inc();
 292        }
 293
 294        bio_put(bio);
 295
 296        iblock_complete_cmd(cmd);
 297}
 298
 299static struct bio *
 300iblock_get_bio(struct se_cmd *cmd, sector_t lba, u32 sg_num)
 301{
 302        struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
 303        struct bio *bio;
 304
 305        /*
 306         * Only allocate as many vector entries as the bio code allows us to,
 307         * we'll loop later on until we have handled the whole request.
 308         */
 309        if (sg_num > BIO_MAX_PAGES)
 310                sg_num = BIO_MAX_PAGES;
 311
 312        bio = bio_alloc_bioset(GFP_NOIO, sg_num, ib_dev->ibd_bio_set);
 313        if (!bio) {
 314                pr_err("Unable to allocate memory for bio\n");
 315                return NULL;
 316        }
 317
 318        bio->bi_bdev = ib_dev->ibd_bd;
 319        bio->bi_private = cmd;
 320        bio->bi_end_io = &iblock_bio_done;
 321        bio->bi_sector = lba;
 322
 323        return bio;
 324}
 325
 326static void iblock_submit_bios(struct bio_list *list, int rw)
 327{
 328        struct blk_plug plug;
 329        struct bio *bio;
 330
 331        blk_start_plug(&plug);
 332        while ((bio = bio_list_pop(list)))
 333                submit_bio(rw, bio);
 334        blk_finish_plug(&plug);
 335}
 336
 337static void iblock_end_io_flush(struct bio *bio, int err)
 338{
 339        struct se_cmd *cmd = bio->bi_private;
 340
 341        if (err)
 342                pr_err("IBLOCK: cache flush failed: %d\n", err);
 343
 344        if (cmd) {
 345                if (err)
 346                        target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
 347                else
 348                        target_complete_cmd(cmd, SAM_STAT_GOOD);
 349        }
 350
 351        bio_put(bio);
 352}
 353
 354/*
 355 * Implement SYCHRONIZE CACHE.  Note that we can't handle lba ranges and must
 356 * always flush the whole cache.
 357 */
 358static sense_reason_t
 359iblock_execute_sync_cache(struct se_cmd *cmd)
 360{
 361        struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
 362        int immed = (cmd->t_task_cdb[1] & 0x2);
 363        struct bio *bio;
 364
 365        /*
 366         * If the Immediate bit is set, queue up the GOOD response
 367         * for this SYNCHRONIZE_CACHE op.
 368         */
 369        if (immed)
 370                target_complete_cmd(cmd, SAM_STAT_GOOD);
 371
 372        bio = bio_alloc(GFP_KERNEL, 0);
 373        bio->bi_end_io = iblock_end_io_flush;
 374        bio->bi_bdev = ib_dev->ibd_bd;
 375        if (!immed)
 376                bio->bi_private = cmd;
 377        submit_bio(WRITE_FLUSH, bio);
 378        return 0;
 379}
 380
 381static sense_reason_t
 382iblock_execute_unmap(struct se_cmd *cmd)
 383{
 384        struct se_device *dev = cmd->se_dev;
 385        struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 386        unsigned char *buf, *ptr = NULL;
 387        sector_t lba;
 388        int size;
 389        u32 range;
 390        sense_reason_t ret = 0;
 391        int dl, bd_dl, err;
 392
 393        if (cmd->data_length < 8) {
 394                pr_warn("UNMAP parameter list length %u too small\n",
 395                        cmd->data_length);
 396                return TCM_INVALID_PARAMETER_LIST;
 397        }
 398
 399        buf = transport_kmap_data_sg(cmd);
 400        if (!buf)
 401                return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 402
 403        dl = get_unaligned_be16(&buf[0]);
 404        bd_dl = get_unaligned_be16(&buf[2]);
 405
 406        size = cmd->data_length - 8;
 407        if (bd_dl > size)
 408                pr_warn("UNMAP parameter list length %u too small, ignoring bd_dl %u\n",
 409                        cmd->data_length, bd_dl);
 410        else
 411                size = bd_dl;
 412
 413        if (size / 16 > dev->dev_attrib.max_unmap_block_desc_count) {
 414                ret = TCM_INVALID_PARAMETER_LIST;
 415                goto err;
 416        }
 417
 418        /* First UNMAP block descriptor starts at 8 byte offset */
 419        ptr = &buf[8];
 420        pr_debug("UNMAP: Sub: %s Using dl: %u bd_dl: %u size: %u"
 421                " ptr: %p\n", dev->transport->name, dl, bd_dl, size, ptr);
 422
 423        while (size >= 16) {
 424                lba = get_unaligned_be64(&ptr[0]);
 425                range = get_unaligned_be32(&ptr[8]);
 426                pr_debug("UNMAP: Using lba: %llu and range: %u\n",
 427                                 (unsigned long long)lba, range);
 428
 429                if (range > dev->dev_attrib.max_unmap_lba_count) {
 430                        ret = TCM_INVALID_PARAMETER_LIST;
 431                        goto err;
 432                }
 433
 434                if (lba + range > dev->transport->get_blocks(dev) + 1) {
 435                        ret = TCM_ADDRESS_OUT_OF_RANGE;
 436                        goto err;
 437                }
 438
 439                err = blkdev_issue_discard(ib_dev->ibd_bd, lba, range,
 440                                           GFP_KERNEL, 0);
 441                if (err < 0) {
 442                        pr_err("blkdev_issue_discard() failed: %d\n",
 443                                        err);
 444                        ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 445                        goto err;
 446                }
 447
 448                ptr += 16;
 449                size -= 16;
 450        }
 451
 452err:
 453        transport_kunmap_data_sg(cmd);
 454        if (!ret)
 455                target_complete_cmd(cmd, GOOD);
 456        return ret;
 457}
 458
 459static sense_reason_t
 460iblock_execute_write_same_unmap(struct se_cmd *cmd)
 461{
 462        struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
 463        int rc;
 464
 465        rc = blkdev_issue_discard(ib_dev->ibd_bd, cmd->t_task_lba,
 466                        spc_get_write_same_sectors(cmd), GFP_KERNEL, 0);
 467        if (rc < 0) {
 468                pr_warn("blkdev_issue_discard() failed: %d\n", rc);
 469                return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 470        }
 471
 472        target_complete_cmd(cmd, GOOD);
 473        return 0;
 474}
 475
 476static sense_reason_t
 477iblock_execute_write_same(struct se_cmd *cmd)
 478{
 479        struct iblock_req *ibr;
 480        struct scatterlist *sg;
 481        struct bio *bio;
 482        struct bio_list list;
 483        sector_t block_lba = cmd->t_task_lba;
 484        sector_t sectors = spc_get_write_same_sectors(cmd);
 485
 486        sg = &cmd->t_data_sg[0];
 487
 488        if (cmd->t_data_nents > 1 ||
 489            sg->length != cmd->se_dev->dev_attrib.block_size) {
 490                pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
 491                        " block_size: %u\n", cmd->t_data_nents, sg->length,
 492                        cmd->se_dev->dev_attrib.block_size);
 493                return TCM_INVALID_CDB_FIELD;
 494        }
 495
 496        ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
 497        if (!ibr)
 498                goto fail;
 499        cmd->priv = ibr;
 500
 501        bio = iblock_get_bio(cmd, block_lba, 1);
 502        if (!bio)
 503                goto fail_free_ibr;
 504
 505        bio_list_init(&list);
 506        bio_list_add(&list, bio);
 507
 508        atomic_set(&ibr->pending, 1);
 509
 510        while (sectors) {
 511                while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
 512                                != sg->length) {
 513
 514                        bio = iblock_get_bio(cmd, block_lba, 1);
 515                        if (!bio)
 516                                goto fail_put_bios;
 517
 518                        atomic_inc(&ibr->pending);
 519                        bio_list_add(&list, bio);
 520                }
 521
 522                /* Always in 512 byte units for Linux/Block */
 523                block_lba += sg->length >> IBLOCK_LBA_SHIFT;
 524                sectors -= 1;
 525        }
 526
 527        iblock_submit_bios(&list, WRITE);
 528        return 0;
 529
 530fail_put_bios:
 531        while ((bio = bio_list_pop(&list)))
 532                bio_put(bio);
 533fail_free_ibr:
 534        kfree(ibr);
 535fail:
 536        return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 537}
 538
 539enum {
 540        Opt_udev_path, Opt_readonly, Opt_force, Opt_err
 541};
 542
 543static match_table_t tokens = {
 544        {Opt_udev_path, "udev_path=%s"},
 545        {Opt_readonly, "readonly=%d"},
 546        {Opt_force, "force=%d"},
 547        {Opt_err, NULL}
 548};
 549
 550static ssize_t iblock_set_configfs_dev_params(struct se_device *dev,
 551                const char *page, ssize_t count)
 552{
 553        struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 554        char *orig, *ptr, *arg_p, *opts;
 555        substring_t args[MAX_OPT_ARGS];
 556        int ret = 0, token;
 557        unsigned long tmp_readonly;
 558
 559        opts = kstrdup(page, GFP_KERNEL);
 560        if (!opts)
 561                return -ENOMEM;
 562
 563        orig = opts;
 564
 565        while ((ptr = strsep(&opts, ",\n")) != NULL) {
 566                if (!*ptr)
 567                        continue;
 568
 569                token = match_token(ptr, tokens, args);
 570                switch (token) {
 571                case Opt_udev_path:
 572                        if (ib_dev->ibd_bd) {
 573                                pr_err("Unable to set udev_path= while"
 574                                        " ib_dev->ibd_bd exists\n");
 575                                ret = -EEXIST;
 576                                goto out;
 577                        }
 578                        if (match_strlcpy(ib_dev->ibd_udev_path, &args[0],
 579                                SE_UDEV_PATH_LEN) == 0) {
 580                                ret = -EINVAL;
 581                                break;
 582                        }
 583                        pr_debug("IBLOCK: Referencing UDEV path: %s\n",
 584                                        ib_dev->ibd_udev_path);
 585                        ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH;
 586                        break;
 587                case Opt_readonly:
 588                        arg_p = match_strdup(&args[0]);
 589                        if (!arg_p) {
 590                                ret = -ENOMEM;
 591                                break;
 592                        }
 593                        ret = strict_strtoul(arg_p, 0, &tmp_readonly);
 594                        kfree(arg_p);
 595                        if (ret < 0) {
 596                                pr_err("strict_strtoul() failed for"
 597                                                " readonly=\n");
 598                                goto out;
 599                        }
 600                        ib_dev->ibd_readonly = tmp_readonly;
 601                        pr_debug("IBLOCK: readonly: %d\n", ib_dev->ibd_readonly);
 602                        break;
 603                case Opt_force:
 604                        break;
 605                default:
 606                        break;
 607                }
 608        }
 609
 610out:
 611        kfree(orig);
 612        return (!ret) ? count : ret;
 613}
 614
 615static ssize_t iblock_show_configfs_dev_params(struct se_device *dev, char *b)
 616{
 617        struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 618        struct block_device *bd = ib_dev->ibd_bd;
 619        char buf[BDEVNAME_SIZE];
 620        ssize_t bl = 0;
 621
 622        if (bd)
 623                bl += sprintf(b + bl, "iBlock device: %s",
 624                                bdevname(bd, buf));
 625        if (ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)
 626                bl += sprintf(b + bl, "  UDEV PATH: %s",
 627                                ib_dev->ibd_udev_path);
 628        bl += sprintf(b + bl, "  readonly: %d\n", ib_dev->ibd_readonly);
 629
 630        bl += sprintf(b + bl, "        ");
 631        if (bd) {
 632                bl += sprintf(b + bl, "Major: %d Minor: %d  %s\n",
 633                        MAJOR(bd->bd_dev), MINOR(bd->bd_dev), (!bd->bd_contains) ?
 634                        "" : (bd->bd_holder == ib_dev) ?
 635                        "CLAIMED: IBLOCK" : "CLAIMED: OS");
 636        } else {
 637                bl += sprintf(b + bl, "Major: 0 Minor: 0\n");
 638        }
 639
 640        return bl;
 641}
 642
 643static sense_reason_t
 644iblock_execute_rw(struct se_cmd *cmd)
 645{
 646        struct scatterlist *sgl = cmd->t_data_sg;
 647        u32 sgl_nents = cmd->t_data_nents;
 648        enum dma_data_direction data_direction = cmd->data_direction;
 649        struct se_device *dev = cmd->se_dev;
 650        struct iblock_req *ibr;
 651        struct bio *bio;
 652        struct bio_list list;
 653        struct scatterlist *sg;
 654        u32 sg_num = sgl_nents;
 655        sector_t block_lba;
 656        unsigned bio_cnt;
 657        int rw;
 658        int i;
 659
 660        if (data_direction == DMA_TO_DEVICE) {
 661                /*
 662                 * Force data to disk if we pretend to not have a volatile
 663                 * write cache, or the initiator set the Force Unit Access bit.
 664                 */
 665                if (dev->dev_attrib.emulate_write_cache == 0 ||
 666                    (dev->dev_attrib.emulate_fua_write > 0 &&
 667                     (cmd->se_cmd_flags & SCF_FUA)))
 668                        rw = WRITE_FUA;
 669                else
 670                        rw = WRITE;
 671        } else {
 672                rw = READ;
 673        }
 674
 675        /*
 676         * Convert the blocksize advertised to the initiator to the 512 byte
 677         * units unconditionally used by the Linux block layer.
 678         */
 679        if (dev->dev_attrib.block_size == 4096)
 680                block_lba = (cmd->t_task_lba << 3);
 681        else if (dev->dev_attrib.block_size == 2048)
 682                block_lba = (cmd->t_task_lba << 2);
 683        else if (dev->dev_attrib.block_size == 1024)
 684                block_lba = (cmd->t_task_lba << 1);
 685        else if (dev->dev_attrib.block_size == 512)
 686                block_lba = cmd->t_task_lba;
 687        else {
 688                pr_err("Unsupported SCSI -> BLOCK LBA conversion:"
 689                                " %u\n", dev->dev_attrib.block_size);
 690                return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 691        }
 692
 693        ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
 694        if (!ibr)
 695                goto fail;
 696        cmd->priv = ibr;
 697
 698        if (!sgl_nents) {
 699                atomic_set(&ibr->pending, 1);
 700                iblock_complete_cmd(cmd);
 701                return 0;
 702        }
 703
 704        bio = iblock_get_bio(cmd, block_lba, sgl_nents);
 705        if (!bio)
 706                goto fail_free_ibr;
 707
 708        bio_list_init(&list);
 709        bio_list_add(&list, bio);
 710
 711        atomic_set(&ibr->pending, 2);
 712        bio_cnt = 1;
 713
 714        for_each_sg(sgl, sg, sgl_nents, i) {
 715                /*
 716                 * XXX: if the length the device accepts is shorter than the
 717                 *      length of the S/G list entry this will cause and
 718                 *      endless loop.  Better hope no driver uses huge pages.
 719                 */
 720                while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
 721                                != sg->length) {
 722                        if (bio_cnt >= IBLOCK_MAX_BIO_PER_TASK) {
 723                                iblock_submit_bios(&list, rw);
 724                                bio_cnt = 0;
 725                        }
 726
 727                        bio = iblock_get_bio(cmd, block_lba, sg_num);
 728                        if (!bio)
 729                                goto fail_put_bios;
 730
 731                        atomic_inc(&ibr->pending);
 732                        bio_list_add(&list, bio);
 733                        bio_cnt++;
 734                }
 735
 736                /* Always in 512 byte units for Linux/Block */
 737                block_lba += sg->length >> IBLOCK_LBA_SHIFT;
 738                sg_num--;
 739        }
 740
 741        iblock_submit_bios(&list, rw);
 742        iblock_complete_cmd(cmd);
 743        return 0;
 744
 745fail_put_bios:
 746        while ((bio = bio_list_pop(&list)))
 747                bio_put(bio);
 748fail_free_ibr:
 749        kfree(ibr);
 750fail:
 751        return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 752}
 753
 754static sector_t iblock_get_blocks(struct se_device *dev)
 755{
 756        struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 757        struct block_device *bd = ib_dev->ibd_bd;
 758        struct request_queue *q = bdev_get_queue(bd);
 759
 760        return iblock_emulate_read_cap_with_block_size(dev, bd, q);
 761}
 762
 763static struct sbc_ops iblock_sbc_ops = {
 764        .execute_rw             = iblock_execute_rw,
 765        .execute_sync_cache     = iblock_execute_sync_cache,
 766        .execute_write_same     = iblock_execute_write_same,
 767        .execute_write_same_unmap = iblock_execute_write_same_unmap,
 768        .execute_unmap          = iblock_execute_unmap,
 769};
 770
 771static sense_reason_t
 772iblock_parse_cdb(struct se_cmd *cmd)
 773{
 774        return sbc_parse_cdb(cmd, &iblock_sbc_ops);
 775}
 776
 777static struct se_subsystem_api iblock_template = {
 778        .name                   = "iblock",
 779        .inquiry_prod           = "IBLOCK",
 780        .inquiry_rev            = IBLOCK_VERSION,
 781        .owner                  = THIS_MODULE,
 782        .transport_type         = TRANSPORT_PLUGIN_VHBA_PDEV,
 783        .attach_hba             = iblock_attach_hba,
 784        .detach_hba             = iblock_detach_hba,
 785        .alloc_device           = iblock_alloc_device,
 786        .configure_device       = iblock_configure_device,
 787        .free_device            = iblock_free_device,
 788        .parse_cdb              = iblock_parse_cdb,
 789        .set_configfs_dev_params = iblock_set_configfs_dev_params,
 790        .show_configfs_dev_params = iblock_show_configfs_dev_params,
 791        .get_device_type        = sbc_get_device_type,
 792        .get_blocks             = iblock_get_blocks,
 793};
 794
 795static int __init iblock_module_init(void)
 796{
 797        return transport_subsystem_register(&iblock_template);
 798}
 799
 800static void iblock_module_exit(void)
 801{
 802        transport_subsystem_release(&iblock_template);
 803}
 804
 805MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin");
 806MODULE_AUTHOR("nab@Linux-iSCSI.org");
 807MODULE_LICENSE("GPL");
 808
 809module_init(iblock_module_init);
 810module_exit(iblock_module_exit);
 811
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