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 2003-2013 Datera, Inc.
   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_proto.h>
  39#include <asm/unaligned.h>
  40
  41#include <target/target_core_base.h>
  42#include <target/target_core_backend.h>
  43
  44#include "target_core_iblock.h"
  45
  46#define IBLOCK_MAX_BIO_PER_TASK  32     /* max # of bios to submit at a time */
  47#define IBLOCK_BIO_POOL_SIZE    128
  48
  49static inline struct iblock_dev *IBLOCK_DEV(struct se_device *dev)
  50{
  51        return container_of(dev, struct iblock_dev, dev);
  52}
  53
  54
  55static int iblock_attach_hba(struct se_hba *hba, u32 host_id)
  56{
  57        pr_debug("CORE_HBA[%d] - TCM iBlock HBA Driver %s on"
  58                " Generic Target Core Stack %s\n", hba->hba_id,
  59                IBLOCK_VERSION, TARGET_CORE_VERSION);
  60        return 0;
  61}
  62
  63static void iblock_detach_hba(struct se_hba *hba)
  64{
  65}
  66
  67static struct se_device *iblock_alloc_device(struct se_hba *hba, const char *name)
  68{
  69        struct iblock_dev *ib_dev = NULL;
  70
  71        ib_dev = kzalloc(sizeof(struct iblock_dev), GFP_KERNEL);
  72        if (!ib_dev) {
  73                pr_err("Unable to allocate struct iblock_dev\n");
  74                return NULL;
  75        }
  76
  77        pr_debug( "IBLOCK: Allocated ib_dev for %s\n", name);
  78
  79        return &ib_dev->dev;
  80}
  81
  82static int iblock_configure_device(struct se_device *dev)
  83{
  84        struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
  85        struct request_queue *q;
  86        struct block_device *bd = NULL;
  87        struct blk_integrity *bi;
  88        fmode_t mode;
  89        unsigned int max_write_zeroes_sectors;
  90        int ret = -ENOMEM;
  91
  92        if (!(ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)) {
  93                pr_err("Missing udev_path= parameters for IBLOCK\n");
  94                return -EINVAL;
  95        }
  96
  97        ib_dev->ibd_bio_set = bioset_create(IBLOCK_BIO_POOL_SIZE, 0, BIOSET_NEED_BVECS);
  98        if (!ib_dev->ibd_bio_set) {
  99                pr_err("IBLOCK: Unable to create bioset\n");
 100                goto out;
 101        }
 102
 103        pr_debug( "IBLOCK: Claiming struct block_device: %s\n",
 104                        ib_dev->ibd_udev_path);
 105
 106        mode = FMODE_READ|FMODE_EXCL;
 107        if (!ib_dev->ibd_readonly)
 108                mode |= FMODE_WRITE;
 109        else
 110                dev->dev_flags |= DF_READ_ONLY;
 111
 112        bd = blkdev_get_by_path(ib_dev->ibd_udev_path, mode, ib_dev);
 113        if (IS_ERR(bd)) {
 114                ret = PTR_ERR(bd);
 115                goto out_free_bioset;
 116        }
 117        ib_dev->ibd_bd = bd;
 118
 119        q = bdev_get_queue(bd);
 120
 121        dev->dev_attrib.hw_block_size = bdev_logical_block_size(bd);
 122        dev->dev_attrib.hw_max_sectors = queue_max_hw_sectors(q);
 123        dev->dev_attrib.hw_queue_depth = q->nr_requests;
 124
 125        if (target_configure_unmap_from_queue(&dev->dev_attrib, q))
 126                pr_debug("IBLOCK: BLOCK Discard support available,"
 127                         " disabled by default\n");
 128
 129        /*
 130         * Enable write same emulation for IBLOCK and use 0xFFFF as
 131         * the smaller WRITE_SAME(10) only has a two-byte block count.
 132         */
 133        max_write_zeroes_sectors = bdev_write_zeroes_sectors(bd);
 134        if (max_write_zeroes_sectors)
 135                dev->dev_attrib.max_write_same_len = max_write_zeroes_sectors;
 136        else
 137                dev->dev_attrib.max_write_same_len = 0xFFFF;
 138
 139        if (blk_queue_nonrot(q))
 140                dev->dev_attrib.is_nonrot = 1;
 141
 142        bi = bdev_get_integrity(bd);
 143        if (bi) {
 144                struct bio_set *bs = ib_dev->ibd_bio_set;
 145
 146                if (!strcmp(bi->profile->name, "T10-DIF-TYPE3-IP") ||
 147                    !strcmp(bi->profile->name, "T10-DIF-TYPE1-IP")) {
 148                        pr_err("IBLOCK export of blk_integrity: %s not"
 149                               " supported\n", bi->profile->name);
 150                        ret = -ENOSYS;
 151                        goto out_blkdev_put;
 152                }
 153
 154                if (!strcmp(bi->profile->name, "T10-DIF-TYPE3-CRC")) {
 155                        dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE3_PROT;
 156                } else if (!strcmp(bi->profile->name, "T10-DIF-TYPE1-CRC")) {
 157                        dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE1_PROT;
 158                }
 159
 160                if (dev->dev_attrib.pi_prot_type) {
 161                        if (bioset_integrity_create(bs, IBLOCK_BIO_POOL_SIZE) < 0) {
 162                                pr_err("Unable to allocate bioset for PI\n");
 163                                ret = -ENOMEM;
 164                                goto out_blkdev_put;
 165                        }
 166                        pr_debug("IBLOCK setup BIP bs->bio_integrity_pool: %p\n",
 167                                 bs->bio_integrity_pool);
 168                }
 169                dev->dev_attrib.hw_pi_prot_type = dev->dev_attrib.pi_prot_type;
 170        }
 171
 172        return 0;
 173
 174out_blkdev_put:
 175        blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
 176out_free_bioset:
 177        bioset_free(ib_dev->ibd_bio_set);
 178        ib_dev->ibd_bio_set = NULL;
 179out:
 180        return ret;
 181}
 182
 183static void iblock_dev_call_rcu(struct rcu_head *p)
 184{
 185        struct se_device *dev = container_of(p, struct se_device, rcu_head);
 186        struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 187
 188        kfree(ib_dev);
 189}
 190
 191static void iblock_free_device(struct se_device *dev)
 192{
 193        call_rcu(&dev->rcu_head, iblock_dev_call_rcu);
 194}
 195
 196static void iblock_destroy_device(struct se_device *dev)
 197{
 198        struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 199
 200        if (ib_dev->ibd_bd != NULL)
 201                blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
 202        if (ib_dev->ibd_bio_set != NULL)
 203                bioset_free(ib_dev->ibd_bio_set);
 204}
 205
 206static unsigned long long iblock_emulate_read_cap_with_block_size(
 207        struct se_device *dev,
 208        struct block_device *bd,
 209        struct request_queue *q)
 210{
 211        unsigned long long blocks_long = (div_u64(i_size_read(bd->bd_inode),
 212                                        bdev_logical_block_size(bd)) - 1);
 213        u32 block_size = bdev_logical_block_size(bd);
 214
 215        if (block_size == dev->dev_attrib.block_size)
 216                return blocks_long;
 217
 218        switch (block_size) {
 219        case 4096:
 220                switch (dev->dev_attrib.block_size) {
 221                case 2048:
 222                        blocks_long <<= 1;
 223                        break;
 224                case 1024:
 225                        blocks_long <<= 2;
 226                        break;
 227                case 512:
 228                        blocks_long <<= 3;
 229                default:
 230                        break;
 231                }
 232                break;
 233        case 2048:
 234                switch (dev->dev_attrib.block_size) {
 235                case 4096:
 236                        blocks_long >>= 1;
 237                        break;
 238                case 1024:
 239                        blocks_long <<= 1;
 240                        break;
 241                case 512:
 242                        blocks_long <<= 2;
 243                        break;
 244                default:
 245                        break;
 246                }
 247                break;
 248        case 1024:
 249                switch (dev->dev_attrib.block_size) {
 250                case 4096:
 251                        blocks_long >>= 2;
 252                        break;
 253                case 2048:
 254                        blocks_long >>= 1;
 255                        break;
 256                case 512:
 257                        blocks_long <<= 1;
 258                        break;
 259                default:
 260                        break;
 261                }
 262                break;
 263        case 512:
 264                switch (dev->dev_attrib.block_size) {
 265                case 4096:
 266                        blocks_long >>= 3;
 267                        break;
 268                case 2048:
 269                        blocks_long >>= 2;
 270                        break;
 271                case 1024:
 272                        blocks_long >>= 1;
 273                        break;
 274                default:
 275                        break;
 276                }
 277                break;
 278        default:
 279                break;
 280        }
 281
 282        return blocks_long;
 283}
 284
 285static void iblock_complete_cmd(struct se_cmd *cmd)
 286{
 287        struct iblock_req *ibr = cmd->priv;
 288        u8 status;
 289
 290        if (!refcount_dec_and_test(&ibr->pending))
 291                return;
 292
 293        if (atomic_read(&ibr->ib_bio_err_cnt))
 294                status = SAM_STAT_CHECK_CONDITION;
 295        else
 296                status = SAM_STAT_GOOD;
 297
 298        target_complete_cmd(cmd, status);
 299        kfree(ibr);
 300}
 301
 302static void iblock_bio_done(struct bio *bio)
 303{
 304        struct se_cmd *cmd = bio->bi_private;
 305        struct iblock_req *ibr = cmd->priv;
 306
 307        if (bio->bi_status) {
 308                pr_err("bio error: %p,  err: %d\n", bio, bio->bi_status);
 309                /*
 310                 * Bump the ib_bio_err_cnt and release bio.
 311                 */
 312                atomic_inc(&ibr->ib_bio_err_cnt);
 313                smp_mb__after_atomic();
 314        }
 315
 316        bio_put(bio);
 317
 318        iblock_complete_cmd(cmd);
 319}
 320
 321static struct bio *
 322iblock_get_bio(struct se_cmd *cmd, sector_t lba, u32 sg_num, int op,
 323               int op_flags)
 324{
 325        struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
 326        struct bio *bio;
 327
 328        /*
 329         * Only allocate as many vector entries as the bio code allows us to,
 330         * we'll loop later on until we have handled the whole request.
 331         */
 332        if (sg_num > BIO_MAX_PAGES)
 333                sg_num = BIO_MAX_PAGES;
 334
 335        bio = bio_alloc_bioset(GFP_NOIO, sg_num, ib_dev->ibd_bio_set);
 336        if (!bio) {
 337                pr_err("Unable to allocate memory for bio\n");
 338                return NULL;
 339        }
 340
 341        bio_set_dev(bio, ib_dev->ibd_bd);
 342        bio->bi_private = cmd;
 343        bio->bi_end_io = &iblock_bio_done;
 344        bio->bi_iter.bi_sector = lba;
 345        bio_set_op_attrs(bio, op, op_flags);
 346
 347        return bio;
 348}
 349
 350static void iblock_submit_bios(struct bio_list *list)
 351{
 352        struct blk_plug plug;
 353        struct bio *bio;
 354
 355        blk_start_plug(&plug);
 356        while ((bio = bio_list_pop(list)))
 357                submit_bio(bio);
 358        blk_finish_plug(&plug);
 359}
 360
 361static void iblock_end_io_flush(struct bio *bio)
 362{
 363        struct se_cmd *cmd = bio->bi_private;
 364
 365        if (bio->bi_status)
 366                pr_err("IBLOCK: cache flush failed: %d\n", bio->bi_status);
 367
 368        if (cmd) {
 369                if (bio->bi_status)
 370                        target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
 371                else
 372                        target_complete_cmd(cmd, SAM_STAT_GOOD);
 373        }
 374
 375        bio_put(bio);
 376}
 377
 378/*
 379 * Implement SYCHRONIZE CACHE.  Note that we can't handle lba ranges and must
 380 * always flush the whole cache.
 381 */
 382static sense_reason_t
 383iblock_execute_sync_cache(struct se_cmd *cmd)
 384{
 385        struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
 386        int immed = (cmd->t_task_cdb[1] & 0x2);
 387        struct bio *bio;
 388
 389        /*
 390         * If the Immediate bit is set, queue up the GOOD response
 391         * for this SYNCHRONIZE_CACHE op.
 392         */
 393        if (immed)
 394                target_complete_cmd(cmd, SAM_STAT_GOOD);
 395
 396        bio = bio_alloc(GFP_KERNEL, 0);
 397        bio->bi_end_io = iblock_end_io_flush;
 398        bio_set_dev(bio, ib_dev->ibd_bd);
 399        bio->bi_opf = REQ_OP_WRITE | REQ_PREFLUSH;
 400        if (!immed)
 401                bio->bi_private = cmd;
 402        submit_bio(bio);
 403        return 0;
 404}
 405
 406static sense_reason_t
 407iblock_execute_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
 408{
 409        struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
 410        struct se_device *dev = cmd->se_dev;
 411        int ret;
 412
 413        ret = blkdev_issue_discard(bdev,
 414                                   target_to_linux_sector(dev, lba),
 415                                   target_to_linux_sector(dev,  nolb),
 416                                   GFP_KERNEL, 0);
 417        if (ret < 0) {
 418                pr_err("blkdev_issue_discard() failed: %d\n", ret);
 419                return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 420        }
 421
 422        return 0;
 423}
 424
 425static sense_reason_t
 426iblock_execute_zero_out(struct block_device *bdev, struct se_cmd *cmd)
 427{
 428        struct se_device *dev = cmd->se_dev;
 429        struct scatterlist *sg = &cmd->t_data_sg[0];
 430        unsigned char *buf, zero = 0x00, *p = &zero;
 431        int rc, ret;
 432
 433        buf = kmap(sg_page(sg)) + sg->offset;
 434        if (!buf)
 435                return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 436        /*
 437         * Fall back to block_execute_write_same() slow-path if
 438         * incoming WRITE_SAME payload does not contain zeros.
 439         */
 440        rc = memcmp(buf, p, cmd->data_length);
 441        kunmap(sg_page(sg));
 442
 443        if (rc)
 444                return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 445
 446        ret = blkdev_issue_zeroout(bdev,
 447                                target_to_linux_sector(dev, cmd->t_task_lba),
 448                                target_to_linux_sector(dev,
 449                                        sbc_get_write_same_sectors(cmd)),
 450                                GFP_KERNEL, false);
 451        if (ret)
 452                return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 453
 454        target_complete_cmd(cmd, GOOD);
 455        return 0;
 456}
 457
 458static sense_reason_t
 459iblock_execute_write_same(struct se_cmd *cmd)
 460{
 461        struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
 462        struct iblock_req *ibr;
 463        struct scatterlist *sg;
 464        struct bio *bio;
 465        struct bio_list list;
 466        struct se_device *dev = cmd->se_dev;
 467        sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba);
 468        sector_t sectors = target_to_linux_sector(dev,
 469                                        sbc_get_write_same_sectors(cmd));
 470
 471        if (cmd->prot_op) {
 472                pr_err("WRITE_SAME: Protection information with IBLOCK"
 473                       " backends not supported\n");
 474                return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 475        }
 476        sg = &cmd->t_data_sg[0];
 477
 478        if (cmd->t_data_nents > 1 ||
 479            sg->length != cmd->se_dev->dev_attrib.block_size) {
 480                pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
 481                        " block_size: %u\n", cmd->t_data_nents, sg->length,
 482                        cmd->se_dev->dev_attrib.block_size);
 483                return TCM_INVALID_CDB_FIELD;
 484        }
 485
 486        if (bdev_write_zeroes_sectors(bdev)) {
 487                if (!iblock_execute_zero_out(bdev, cmd))
 488                        return 0;
 489        }
 490
 491        ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
 492        if (!ibr)
 493                goto fail;
 494        cmd->priv = ibr;
 495
 496        bio = iblock_get_bio(cmd, block_lba, 1, REQ_OP_WRITE, 0);
 497        if (!bio)
 498                goto fail_free_ibr;
 499
 500        bio_list_init(&list);
 501        bio_list_add(&list, bio);
 502
 503        refcount_set(&ibr->pending, 1);
 504
 505        while (sectors) {
 506                while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
 507                                != sg->length) {
 508
 509                        bio = iblock_get_bio(cmd, block_lba, 1, REQ_OP_WRITE,
 510                                             0);
 511                        if (!bio)
 512                                goto fail_put_bios;
 513
 514                        refcount_inc(&ibr->pending);
 515                        bio_list_add(&list, bio);
 516                }
 517
 518                /* Always in 512 byte units for Linux/Block */
 519                block_lba += sg->length >> IBLOCK_LBA_SHIFT;
 520                sectors -= 1;
 521        }
 522
 523        iblock_submit_bios(&list);
 524        return 0;
 525
 526fail_put_bios:
 527        while ((bio = bio_list_pop(&list)))
 528                bio_put(bio);
 529fail_free_ibr:
 530        kfree(ibr);
 531fail:
 532        return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 533}
 534
 535enum {
 536        Opt_udev_path, Opt_readonly, Opt_force, Opt_err
 537};
 538
 539static match_table_t tokens = {
 540        {Opt_udev_path, "udev_path=%s"},
 541        {Opt_readonly, "readonly=%d"},
 542        {Opt_force, "force=%d"},
 543        {Opt_err, NULL}
 544};
 545
 546static ssize_t iblock_set_configfs_dev_params(struct se_device *dev,
 547                const char *page, ssize_t count)
 548{
 549        struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 550        char *orig, *ptr, *arg_p, *opts;
 551        substring_t args[MAX_OPT_ARGS];
 552        int ret = 0, token;
 553        unsigned long tmp_readonly;
 554
 555        opts = kstrdup(page, GFP_KERNEL);
 556        if (!opts)
 557                return -ENOMEM;
 558
 559        orig = opts;
 560
 561        while ((ptr = strsep(&opts, ",\n")) != NULL) {
 562                if (!*ptr)
 563                        continue;
 564
 565                token = match_token(ptr, tokens, args);
 566                switch (token) {
 567                case Opt_udev_path:
 568                        if (ib_dev->ibd_bd) {
 569                                pr_err("Unable to set udev_path= while"
 570                                        " ib_dev->ibd_bd exists\n");
 571                                ret = -EEXIST;
 572                                goto out;
 573                        }
 574                        if (match_strlcpy(ib_dev->ibd_udev_path, &args[0],
 575                                SE_UDEV_PATH_LEN) == 0) {
 576                                ret = -EINVAL;
 577                                break;
 578                        }
 579                        pr_debug("IBLOCK: Referencing UDEV path: %s\n",
 580                                        ib_dev->ibd_udev_path);
 581                        ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH;
 582                        break;
 583                case Opt_readonly:
 584                        arg_p = match_strdup(&args[0]);
 585                        if (!arg_p) {
 586                                ret = -ENOMEM;
 587                                break;
 588                        }
 589                        ret = kstrtoul(arg_p, 0, &tmp_readonly);
 590                        kfree(arg_p);
 591                        if (ret < 0) {
 592                                pr_err("kstrtoul() failed for"
 593                                                " readonly=\n");
 594                                goto out;
 595                        }
 596                        ib_dev->ibd_readonly = tmp_readonly;
 597                        pr_debug("IBLOCK: readonly: %d\n", ib_dev->ibd_readonly);
 598                        break;
 599                case Opt_force:
 600                        break;
 601                default:
 602                        break;
 603                }
 604        }
 605
 606out:
 607        kfree(orig);
 608        return (!ret) ? count : ret;
 609}
 610
 611static ssize_t iblock_show_configfs_dev_params(struct se_device *dev, char *b)
 612{
 613        struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 614        struct block_device *bd = ib_dev->ibd_bd;
 615        char buf[BDEVNAME_SIZE];
 616        ssize_t bl = 0;
 617
 618        if (bd)
 619                bl += sprintf(b + bl, "iBlock device: %s",
 620                                bdevname(bd, buf));
 621        if (ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)
 622                bl += sprintf(b + bl, "  UDEV PATH: %s",
 623                                ib_dev->ibd_udev_path);
 624        bl += sprintf(b + bl, "  readonly: %d\n", ib_dev->ibd_readonly);
 625
 626        bl += sprintf(b + bl, "        ");
 627        if (bd) {
 628                bl += sprintf(b + bl, "Major: %d Minor: %d  %s\n",
 629                        MAJOR(bd->bd_dev), MINOR(bd->bd_dev), (!bd->bd_contains) ?
 630                        "" : (bd->bd_holder == ib_dev) ?
 631                        "CLAIMED: IBLOCK" : "CLAIMED: OS");
 632        } else {
 633                bl += sprintf(b + bl, "Major: 0 Minor: 0\n");
 634        }
 635
 636        return bl;
 637}
 638
 639static int
 640iblock_alloc_bip(struct se_cmd *cmd, struct bio *bio)
 641{
 642        struct se_device *dev = cmd->se_dev;
 643        struct blk_integrity *bi;
 644        struct bio_integrity_payload *bip;
 645        struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 646        struct scatterlist *sg;
 647        int i, rc;
 648
 649        bi = bdev_get_integrity(ib_dev->ibd_bd);
 650        if (!bi) {
 651                pr_err("Unable to locate bio_integrity\n");
 652                return -ENODEV;
 653        }
 654
 655        bip = bio_integrity_alloc(bio, GFP_NOIO, cmd->t_prot_nents);
 656        if (IS_ERR(bip)) {
 657                pr_err("Unable to allocate bio_integrity_payload\n");
 658                return PTR_ERR(bip);
 659        }
 660
 661        bip->bip_iter.bi_size = (cmd->data_length / dev->dev_attrib.block_size) *
 662                         dev->prot_length;
 663        bip->bip_iter.bi_sector = bio->bi_iter.bi_sector;
 664
 665        pr_debug("IBLOCK BIP Size: %u Sector: %llu\n", bip->bip_iter.bi_size,
 666                 (unsigned long long)bip->bip_iter.bi_sector);
 667
 668        for_each_sg(cmd->t_prot_sg, sg, cmd->t_prot_nents, i) {
 669
 670                rc = bio_integrity_add_page(bio, sg_page(sg), sg->length,
 671                                            sg->offset);
 672                if (rc != sg->length) {
 673                        pr_err("bio_integrity_add_page() failed; %d\n", rc);
 674                        return -ENOMEM;
 675                }
 676
 677                pr_debug("Added bio integrity page: %p length: %d offset; %d\n",
 678                         sg_page(sg), sg->length, sg->offset);
 679        }
 680
 681        return 0;
 682}
 683
 684static sense_reason_t
 685iblock_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 686                  enum dma_data_direction data_direction)
 687{
 688        struct se_device *dev = cmd->se_dev;
 689        sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba);
 690        struct iblock_req *ibr;
 691        struct bio *bio, *bio_start;
 692        struct bio_list list;
 693        struct scatterlist *sg;
 694        u32 sg_num = sgl_nents;
 695        unsigned bio_cnt;
 696        int i, op, op_flags = 0;
 697
 698        if (data_direction == DMA_TO_DEVICE) {
 699                struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 700                struct request_queue *q = bdev_get_queue(ib_dev->ibd_bd);
 701                /*
 702                 * Force writethrough using REQ_FUA if a volatile write cache
 703                 * is not enabled, or if initiator set the Force Unit Access bit.
 704                 */
 705                op = REQ_OP_WRITE;
 706                if (test_bit(QUEUE_FLAG_FUA, &q->queue_flags)) {
 707                        if (cmd->se_cmd_flags & SCF_FUA)
 708                                op_flags = REQ_FUA;
 709                        else if (!test_bit(QUEUE_FLAG_WC, &q->queue_flags))
 710                                op_flags = REQ_FUA;
 711                }
 712        } else {
 713                op = REQ_OP_READ;
 714        }
 715
 716        ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
 717        if (!ibr)
 718                goto fail;
 719        cmd->priv = ibr;
 720
 721        if (!sgl_nents) {
 722                refcount_set(&ibr->pending, 1);
 723                iblock_complete_cmd(cmd);
 724                return 0;
 725        }
 726
 727        bio = iblock_get_bio(cmd, block_lba, sgl_nents, op, op_flags);
 728        if (!bio)
 729                goto fail_free_ibr;
 730
 731        bio_start = bio;
 732        bio_list_init(&list);
 733        bio_list_add(&list, bio);
 734
 735        refcount_set(&ibr->pending, 2);
 736        bio_cnt = 1;
 737
 738        for_each_sg(sgl, sg, sgl_nents, i) {
 739                /*
 740                 * XXX: if the length the device accepts is shorter than the
 741                 *      length of the S/G list entry this will cause and
 742                 *      endless loop.  Better hope no driver uses huge pages.
 743                 */
 744                while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
 745                                != sg->length) {
 746                        if (bio_cnt >= IBLOCK_MAX_BIO_PER_TASK) {
 747                                iblock_submit_bios(&list);
 748                                bio_cnt = 0;
 749                        }
 750
 751                        bio = iblock_get_bio(cmd, block_lba, sg_num, op,
 752                                             op_flags);
 753                        if (!bio)
 754                                goto fail_put_bios;
 755
 756                        refcount_inc(&ibr->pending);
 757                        bio_list_add(&list, bio);
 758                        bio_cnt++;
 759                }
 760
 761                /* Always in 512 byte units for Linux/Block */
 762                block_lba += sg->length >> IBLOCK_LBA_SHIFT;
 763                sg_num--;
 764        }
 765
 766        if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
 767                int rc = iblock_alloc_bip(cmd, bio_start);
 768                if (rc)
 769                        goto fail_put_bios;
 770        }
 771
 772        iblock_submit_bios(&list);
 773        iblock_complete_cmd(cmd);
 774        return 0;
 775
 776fail_put_bios:
 777        while ((bio = bio_list_pop(&list)))
 778                bio_put(bio);
 779fail_free_ibr:
 780        kfree(ibr);
 781fail:
 782        return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 783}
 784
 785static sector_t iblock_get_blocks(struct se_device *dev)
 786{
 787        struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 788        struct block_device *bd = ib_dev->ibd_bd;
 789        struct request_queue *q = bdev_get_queue(bd);
 790
 791        return iblock_emulate_read_cap_with_block_size(dev, bd, q);
 792}
 793
 794static sector_t iblock_get_alignment_offset_lbas(struct se_device *dev)
 795{
 796        struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 797        struct block_device *bd = ib_dev->ibd_bd;
 798        int ret;
 799
 800        ret = bdev_alignment_offset(bd);
 801        if (ret == -1)
 802                return 0;
 803
 804        /* convert offset-bytes to offset-lbas */
 805        return ret / bdev_logical_block_size(bd);
 806}
 807
 808static unsigned int iblock_get_lbppbe(struct se_device *dev)
 809{
 810        struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 811        struct block_device *bd = ib_dev->ibd_bd;
 812        int logs_per_phys = bdev_physical_block_size(bd) / bdev_logical_block_size(bd);
 813
 814        return ilog2(logs_per_phys);
 815}
 816
 817static unsigned int iblock_get_io_min(struct se_device *dev)
 818{
 819        struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 820        struct block_device *bd = ib_dev->ibd_bd;
 821
 822        return bdev_io_min(bd);
 823}
 824
 825static unsigned int iblock_get_io_opt(struct se_device *dev)
 826{
 827        struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 828        struct block_device *bd = ib_dev->ibd_bd;
 829
 830        return bdev_io_opt(bd);
 831}
 832
 833static struct sbc_ops iblock_sbc_ops = {
 834        .execute_rw             = iblock_execute_rw,
 835        .execute_sync_cache     = iblock_execute_sync_cache,
 836        .execute_write_same     = iblock_execute_write_same,
 837        .execute_unmap          = iblock_execute_unmap,
 838};
 839
 840static sense_reason_t
 841iblock_parse_cdb(struct se_cmd *cmd)
 842{
 843        return sbc_parse_cdb(cmd, &iblock_sbc_ops);
 844}
 845
 846static bool iblock_get_write_cache(struct se_device *dev)
 847{
 848        struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 849        struct block_device *bd = ib_dev->ibd_bd;
 850        struct request_queue *q = bdev_get_queue(bd);
 851
 852        return test_bit(QUEUE_FLAG_WC, &q->queue_flags);
 853}
 854
 855static const struct target_backend_ops iblock_ops = {
 856        .name                   = "iblock",
 857        .inquiry_prod           = "IBLOCK",
 858        .inquiry_rev            = IBLOCK_VERSION,
 859        .owner                  = THIS_MODULE,
 860        .attach_hba             = iblock_attach_hba,
 861        .detach_hba             = iblock_detach_hba,
 862        .alloc_device           = iblock_alloc_device,
 863        .configure_device       = iblock_configure_device,
 864        .destroy_device         = iblock_destroy_device,
 865        .free_device            = iblock_free_device,
 866        .parse_cdb              = iblock_parse_cdb,
 867        .set_configfs_dev_params = iblock_set_configfs_dev_params,
 868        .show_configfs_dev_params = iblock_show_configfs_dev_params,
 869        .get_device_type        = sbc_get_device_type,
 870        .get_blocks             = iblock_get_blocks,
 871        .get_alignment_offset_lbas = iblock_get_alignment_offset_lbas,
 872        .get_lbppbe             = iblock_get_lbppbe,
 873        .get_io_min             = iblock_get_io_min,
 874        .get_io_opt             = iblock_get_io_opt,
 875        .get_write_cache        = iblock_get_write_cache,
 876        .tb_dev_attrib_attrs    = sbc_attrib_attrs,
 877};
 878
 879static int __init iblock_module_init(void)
 880{
 881        return transport_backend_register(&iblock_ops);
 882}
 883
 884static void __exit iblock_module_exit(void)
 885{
 886        target_backend_unregister(&iblock_ops);
 887}
 888
 889MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin");
 890MODULE_AUTHOR("nab@Linux-iSCSI.org");
 891MODULE_LICENSE("GPL");
 892
 893module_init(iblock_module_init);
 894module_exit(iblock_module_exit);
 895