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        ret = bioset_init(&ib_dev->ibd_bio_set, IBLOCK_BIO_POOL_SIZE, 0, BIOSET_NEED_BVECS);
  98        if (ret) {
  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_exit(&ib_dev->ibd_bio_set);
 178out:
 179        return ret;
 180}
 181
 182static void iblock_dev_call_rcu(struct rcu_head *p)
 183{
 184        struct se_device *dev = container_of(p, struct se_device, rcu_head);
 185        struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 186
 187        kfree(ib_dev);
 188}
 189
 190static void iblock_free_device(struct se_device *dev)
 191{
 192        call_rcu(&dev->rcu_head, iblock_dev_call_rcu);
 193}
 194
 195static void iblock_destroy_device(struct se_device *dev)
 196{
 197        struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 198
 199        if (ib_dev->ibd_bd != NULL)
 200                blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
 201        bioset_exit(&ib_dev->ibd_bio_set);
 202}
 203
 204static unsigned long long iblock_emulate_read_cap_with_block_size(
 205        struct se_device *dev,
 206        struct block_device *bd,
 207        struct request_queue *q)
 208{
 209        unsigned long long blocks_long = (div_u64(i_size_read(bd->bd_inode),
 210                                        bdev_logical_block_size(bd)) - 1);
 211        u32 block_size = bdev_logical_block_size(bd);
 212
 213        if (block_size == dev->dev_attrib.block_size)
 214                return blocks_long;
 215
 216        switch (block_size) {
 217        case 4096:
 218                switch (dev->dev_attrib.block_size) {
 219                case 2048:
 220                        blocks_long <<= 1;
 221                        break;
 222                case 1024:
 223                        blocks_long <<= 2;
 224                        break;
 225                case 512:
 226                        blocks_long <<= 3;
 227                default:
 228                        break;
 229                }
 230                break;
 231        case 2048:
 232                switch (dev->dev_attrib.block_size) {
 233                case 4096:
 234                        blocks_long >>= 1;
 235                        break;
 236                case 1024:
 237                        blocks_long <<= 1;
 238                        break;
 239                case 512:
 240                        blocks_long <<= 2;
 241                        break;
 242                default:
 243                        break;
 244                }
 245                break;
 246        case 1024:
 247                switch (dev->dev_attrib.block_size) {
 248                case 4096:
 249                        blocks_long >>= 2;
 250                        break;
 251                case 2048:
 252                        blocks_long >>= 1;
 253                        break;
 254                case 512:
 255                        blocks_long <<= 1;
 256                        break;
 257                default:
 258                        break;
 259                }
 260                break;
 261        case 512:
 262                switch (dev->dev_attrib.block_size) {
 263                case 4096:
 264                        blocks_long >>= 3;
 265                        break;
 266                case 2048:
 267                        blocks_long >>= 2;
 268                        break;
 269                case 1024:
 270                        blocks_long >>= 1;
 271                        break;
 272                default:
 273                        break;
 274                }
 275                break;
 276        default:
 277                break;
 278        }
 279
 280        return blocks_long;
 281}
 282
 283static void iblock_complete_cmd(struct se_cmd *cmd)
 284{
 285        struct iblock_req *ibr = cmd->priv;
 286        u8 status;
 287
 288        if (!refcount_dec_and_test(&ibr->pending))
 289                return;
 290
 291        if (atomic_read(&ibr->ib_bio_err_cnt))
 292                status = SAM_STAT_CHECK_CONDITION;
 293        else
 294                status = SAM_STAT_GOOD;
 295
 296        target_complete_cmd(cmd, status);
 297        kfree(ibr);
 298}
 299
 300static void iblock_bio_done(struct bio *bio)
 301{
 302        struct se_cmd *cmd = bio->bi_private;
 303        struct iblock_req *ibr = cmd->priv;
 304
 305        if (bio->bi_status) {
 306                pr_err("bio error: %p,  err: %d\n", bio, bio->bi_status);
 307                /*
 308                 * Bump the ib_bio_err_cnt and release bio.
 309                 */
 310                atomic_inc(&ibr->ib_bio_err_cnt);
 311                smp_mb__after_atomic();
 312        }
 313
 314        bio_put(bio);
 315
 316        iblock_complete_cmd(cmd);
 317}
 318
 319static struct bio *
 320iblock_get_bio(struct se_cmd *cmd, sector_t lba, u32 sg_num, int op,
 321               int op_flags)
 322{
 323        struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
 324        struct bio *bio;
 325
 326        /*
 327         * Only allocate as many vector entries as the bio code allows us to,
 328         * we'll loop later on until we have handled the whole request.
 329         */
 330        if (sg_num > BIO_MAX_PAGES)
 331                sg_num = BIO_MAX_PAGES;
 332
 333        bio = bio_alloc_bioset(GFP_NOIO, sg_num, &ib_dev->ibd_bio_set);
 334        if (!bio) {
 335                pr_err("Unable to allocate memory for bio\n");
 336                return NULL;
 337        }
 338
 339        bio_set_dev(bio, ib_dev->ibd_bd);
 340        bio->bi_private = cmd;
 341        bio->bi_end_io = &iblock_bio_done;
 342        bio->bi_iter.bi_sector = lba;
 343        bio_set_op_attrs(bio, op, op_flags);
 344
 345        return bio;
 346}
 347
 348static void iblock_submit_bios(struct bio_list *list)
 349{
 350        struct blk_plug plug;
 351        struct bio *bio;
 352
 353        blk_start_plug(&plug);
 354        while ((bio = bio_list_pop(list)))
 355                submit_bio(bio);
 356        blk_finish_plug(&plug);
 357}
 358
 359static void iblock_end_io_flush(struct bio *bio)
 360{
 361        struct se_cmd *cmd = bio->bi_private;
 362
 363        if (bio->bi_status)
 364                pr_err("IBLOCK: cache flush failed: %d\n", bio->bi_status);
 365
 366        if (cmd) {
 367                if (bio->bi_status)
 368                        target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
 369                else
 370                        target_complete_cmd(cmd, SAM_STAT_GOOD);
 371        }
 372
 373        bio_put(bio);
 374}
 375
 376/*
 377 * Implement SYCHRONIZE CACHE.  Note that we can't handle lba ranges and must
 378 * always flush the whole cache.
 379 */
 380static sense_reason_t
 381iblock_execute_sync_cache(struct se_cmd *cmd)
 382{
 383        struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
 384        int immed = (cmd->t_task_cdb[1] & 0x2);
 385        struct bio *bio;
 386
 387        /*
 388         * If the Immediate bit is set, queue up the GOOD response
 389         * for this SYNCHRONIZE_CACHE op.
 390         */
 391        if (immed)
 392                target_complete_cmd(cmd, SAM_STAT_GOOD);
 393
 394        bio = bio_alloc(GFP_KERNEL, 0);
 395        bio->bi_end_io = iblock_end_io_flush;
 396        bio_set_dev(bio, ib_dev->ibd_bd);
 397        bio->bi_opf = REQ_OP_WRITE | REQ_PREFLUSH;
 398        if (!immed)
 399                bio->bi_private = cmd;
 400        submit_bio(bio);
 401        return 0;
 402}
 403
 404static sense_reason_t
 405iblock_execute_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
 406{
 407        struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
 408        struct se_device *dev = cmd->se_dev;
 409        int ret;
 410
 411        ret = blkdev_issue_discard(bdev,
 412                                   target_to_linux_sector(dev, lba),
 413                                   target_to_linux_sector(dev,  nolb),
 414                                   GFP_KERNEL, 0);
 415        if (ret < 0) {
 416                pr_err("blkdev_issue_discard() failed: %d\n", ret);
 417                return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 418        }
 419
 420        return 0;
 421}
 422
 423static sense_reason_t
 424iblock_execute_zero_out(struct block_device *bdev, struct se_cmd *cmd)
 425{
 426        struct se_device *dev = cmd->se_dev;
 427        struct scatterlist *sg = &cmd->t_data_sg[0];
 428        unsigned char *buf, *not_zero;
 429        int ret;
 430
 431        buf = kmap(sg_page(sg)) + sg->offset;
 432        if (!buf)
 433                return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 434        /*
 435         * Fall back to block_execute_write_same() slow-path if
 436         * incoming WRITE_SAME payload does not contain zeros.
 437         */
 438        not_zero = memchr_inv(buf, 0x00, cmd->data_length);
 439        kunmap(sg_page(sg));
 440
 441        if (not_zero)
 442                return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 443
 444        ret = blkdev_issue_zeroout(bdev,
 445                                target_to_linux_sector(dev, cmd->t_task_lba),
 446                                target_to_linux_sector(dev,
 447                                        sbc_get_write_same_sectors(cmd)),
 448                                GFP_KERNEL, BLKDEV_ZERO_NOUNMAP);
 449        if (ret)
 450                return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 451
 452        target_complete_cmd(cmd, GOOD);
 453        return 0;
 454}
 455
 456static sense_reason_t
 457iblock_execute_write_same(struct se_cmd *cmd)
 458{
 459        struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
 460        struct iblock_req *ibr;
 461        struct scatterlist *sg;
 462        struct bio *bio;
 463        struct bio_list list;
 464        struct se_device *dev = cmd->se_dev;
 465        sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba);
 466        sector_t sectors = target_to_linux_sector(dev,
 467                                        sbc_get_write_same_sectors(cmd));
 468
 469        if (cmd->prot_op) {
 470                pr_err("WRITE_SAME: Protection information with IBLOCK"
 471                       " backends not supported\n");
 472                return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 473        }
 474        sg = &cmd->t_data_sg[0];
 475
 476        if (cmd->t_data_nents > 1 ||
 477            sg->length != cmd->se_dev->dev_attrib.block_size) {
 478                pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
 479                        " block_size: %u\n", cmd->t_data_nents, sg->length,
 480                        cmd->se_dev->dev_attrib.block_size);
 481                return TCM_INVALID_CDB_FIELD;
 482        }
 483
 484        if (bdev_write_zeroes_sectors(bdev)) {
 485                if (!iblock_execute_zero_out(bdev, cmd))
 486                        return 0;
 487        }
 488
 489        ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
 490        if (!ibr)
 491                goto fail;
 492        cmd->priv = ibr;
 493
 494        bio = iblock_get_bio(cmd, block_lba, 1, REQ_OP_WRITE, 0);
 495        if (!bio)
 496                goto fail_free_ibr;
 497
 498        bio_list_init(&list);
 499        bio_list_add(&list, bio);
 500
 501        refcount_set(&ibr->pending, 1);
 502
 503        while (sectors) {
 504                while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
 505                                != sg->length) {
 506
 507                        bio = iblock_get_bio(cmd, block_lba, 1, REQ_OP_WRITE,
 508                                             0);
 509                        if (!bio)
 510                                goto fail_put_bios;
 511
 512                        refcount_inc(&ibr->pending);
 513                        bio_list_add(&list, bio);
 514                }
 515
 516                /* Always in 512 byte units for Linux/Block */
 517                block_lba += sg->length >> SECTOR_SHIFT;
 518                sectors -= sg->length >> SECTOR_SHIFT;
 519        }
 520
 521        iblock_submit_bios(&list);
 522        return 0;
 523
 524fail_put_bios:
 525        while ((bio = bio_list_pop(&list)))
 526                bio_put(bio);
 527fail_free_ibr:
 528        kfree(ibr);
 529fail:
 530        return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 531}
 532
 533enum {
 534        Opt_udev_path, Opt_readonly, Opt_force, Opt_err
 535};
 536
 537static match_table_t tokens = {
 538        {Opt_udev_path, "udev_path=%s"},
 539        {Opt_readonly, "readonly=%d"},
 540        {Opt_force, "force=%d"},
 541        {Opt_err, NULL}
 542};
 543
 544static ssize_t iblock_set_configfs_dev_params(struct se_device *dev,
 545                const char *page, ssize_t count)
 546{
 547        struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 548        char *orig, *ptr, *arg_p, *opts;
 549        substring_t args[MAX_OPT_ARGS];
 550        int ret = 0, token;
 551        unsigned long tmp_readonly;
 552
 553        opts = kstrdup(page, GFP_KERNEL);
 554        if (!opts)
 555                return -ENOMEM;
 556
 557        orig = opts;
 558
 559        while ((ptr = strsep(&opts, ",\n")) != NULL) {
 560                if (!*ptr)
 561                        continue;
 562
 563                token = match_token(ptr, tokens, args);
 564                switch (token) {
 565                case Opt_udev_path:
 566                        if (ib_dev->ibd_bd) {
 567                                pr_err("Unable to set udev_path= while"
 568                                        " ib_dev->ibd_bd exists\n");
 569                                ret = -EEXIST;
 570                                goto out;
 571                        }
 572                        if (match_strlcpy(ib_dev->ibd_udev_path, &args[0],
 573                                SE_UDEV_PATH_LEN) == 0) {
 574                                ret = -EINVAL;
 575                                break;
 576                        }
 577                        pr_debug("IBLOCK: Referencing UDEV path: %s\n",
 578                                        ib_dev->ibd_udev_path);
 579                        ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH;
 580                        break;
 581                case Opt_readonly:
 582                        arg_p = match_strdup(&args[0]);
 583                        if (!arg_p) {
 584                                ret = -ENOMEM;
 585                                break;
 586                        }
 587                        ret = kstrtoul(arg_p, 0, &tmp_readonly);
 588                        kfree(arg_p);
 589                        if (ret < 0) {
 590                                pr_err("kstrtoul() failed for"
 591                                                " readonly=\n");
 592                                goto out;
 593                        }
 594                        ib_dev->ibd_readonly = tmp_readonly;
 595                        pr_debug("IBLOCK: readonly: %d\n", ib_dev->ibd_readonly);
 596                        break;
 597                case Opt_force:
 598                        break;
 599                default:
 600                        break;
 601                }
 602        }
 603
 604out:
 605        kfree(orig);
 606        return (!ret) ? count : ret;
 607}
 608
 609static ssize_t iblock_show_configfs_dev_params(struct se_device *dev, char *b)
 610{
 611        struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 612        struct block_device *bd = ib_dev->ibd_bd;
 613        char buf[BDEVNAME_SIZE];
 614        ssize_t bl = 0;
 615
 616        if (bd)
 617                bl += sprintf(b + bl, "iBlock device: %s",
 618                                bdevname(bd, buf));
 619        if (ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)
 620                bl += sprintf(b + bl, "  UDEV PATH: %s",
 621                                ib_dev->ibd_udev_path);
 622        bl += sprintf(b + bl, "  readonly: %d\n", ib_dev->ibd_readonly);
 623
 624        bl += sprintf(b + bl, "        ");
 625        if (bd) {
 626                bl += sprintf(b + bl, "Major: %d Minor: %d  %s\n",
 627                        MAJOR(bd->bd_dev), MINOR(bd->bd_dev), (!bd->bd_contains) ?
 628                        "" : (bd->bd_holder == ib_dev) ?
 629                        "CLAIMED: IBLOCK" : "CLAIMED: OS");
 630        } else {
 631                bl += sprintf(b + bl, "Major: 0 Minor: 0\n");
 632        }
 633
 634        return bl;
 635}
 636
 637static int
 638iblock_alloc_bip(struct se_cmd *cmd, struct bio *bio,
 639                 struct sg_mapping_iter *miter)
 640{
 641        struct se_device *dev = cmd->se_dev;
 642        struct blk_integrity *bi;
 643        struct bio_integrity_payload *bip;
 644        struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 645        int rc;
 646        size_t resid, len;
 647
 648        bi = bdev_get_integrity(ib_dev->ibd_bd);
 649        if (!bi) {
 650                pr_err("Unable to locate bio_integrity\n");
 651                return -ENODEV;
 652        }
 653
 654        bip = bio_integrity_alloc(bio, GFP_NOIO,
 655                        min_t(unsigned int, cmd->t_prot_nents, BIO_MAX_PAGES));
 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 = bio_integrity_bytes(bi, bio_sectors(bio));
 662        /* virtual start sector must be in integrity interval units */
 663        bip_set_seed(bip, bio->bi_iter.bi_sector >>
 664                                  (bi->interval_exp - SECTOR_SHIFT));
 665
 666        pr_debug("IBLOCK BIP Size: %u Sector: %llu\n", bip->bip_iter.bi_size,
 667                 (unsigned long long)bip->bip_iter.bi_sector);
 668
 669        resid = bip->bip_iter.bi_size;
 670        while (resid > 0 && sg_miter_next(miter)) {
 671
 672                len = min_t(size_t, miter->length, resid);
 673                rc = bio_integrity_add_page(bio, miter->page, len,
 674                                            offset_in_page(miter->addr));
 675                if (rc != len) {
 676                        pr_err("bio_integrity_add_page() failed; %d\n", rc);
 677                        sg_miter_stop(miter);
 678                        return -ENOMEM;
 679                }
 680
 681                pr_debug("Added bio integrity page: %p length: %zu offset: %lu\n",
 682                          miter->page, len, offset_in_page(miter->addr));
 683
 684                resid -= len;
 685                if (len < miter->length)
 686                        miter->consumed -= miter->length - len;
 687        }
 688        sg_miter_stop(miter);
 689
 690        return 0;
 691}
 692
 693static sense_reason_t
 694iblock_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 695                  enum dma_data_direction data_direction)
 696{
 697        struct se_device *dev = cmd->se_dev;
 698        sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba);
 699        struct iblock_req *ibr;
 700        struct bio *bio;
 701        struct bio_list list;
 702        struct scatterlist *sg;
 703        u32 sg_num = sgl_nents;
 704        unsigned bio_cnt;
 705        int i, rc, op, op_flags = 0;
 706        struct sg_mapping_iter prot_miter;
 707
 708        if (data_direction == DMA_TO_DEVICE) {
 709                struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 710                struct request_queue *q = bdev_get_queue(ib_dev->ibd_bd);
 711                /*
 712                 * Force writethrough using REQ_FUA if a volatile write cache
 713                 * is not enabled, or if initiator set the Force Unit Access bit.
 714                 */
 715                op = REQ_OP_WRITE;
 716                if (test_bit(QUEUE_FLAG_FUA, &q->queue_flags)) {
 717                        if (cmd->se_cmd_flags & SCF_FUA)
 718                                op_flags = REQ_FUA;
 719                        else if (!test_bit(QUEUE_FLAG_WC, &q->queue_flags))
 720                                op_flags = REQ_FUA;
 721                }
 722        } else {
 723                op = REQ_OP_READ;
 724        }
 725
 726        ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
 727        if (!ibr)
 728                goto fail;
 729        cmd->priv = ibr;
 730
 731        if (!sgl_nents) {
 732                refcount_set(&ibr->pending, 1);
 733                iblock_complete_cmd(cmd);
 734                return 0;
 735        }
 736
 737        bio = iblock_get_bio(cmd, block_lba, sgl_nents, op, op_flags);
 738        if (!bio)
 739                goto fail_free_ibr;
 740
 741        bio_list_init(&list);
 742        bio_list_add(&list, bio);
 743
 744        refcount_set(&ibr->pending, 2);
 745        bio_cnt = 1;
 746
 747        if (cmd->prot_type && dev->dev_attrib.pi_prot_type)
 748                sg_miter_start(&prot_miter, cmd->t_prot_sg, cmd->t_prot_nents,
 749                               op == REQ_OP_READ ? SG_MITER_FROM_SG :
 750                                                   SG_MITER_TO_SG);
 751
 752        for_each_sg(sgl, sg, sgl_nents, i) {
 753                /*
 754                 * XXX: if the length the device accepts is shorter than the
 755                 *      length of the S/G list entry this will cause and
 756                 *      endless loop.  Better hope no driver uses huge pages.
 757                 */
 758                while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
 759                                != sg->length) {
 760                        if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
 761                                rc = iblock_alloc_bip(cmd, bio, &prot_miter);
 762                                if (rc)
 763                                        goto fail_put_bios;
 764                        }
 765
 766                        if (bio_cnt >= IBLOCK_MAX_BIO_PER_TASK) {
 767                                iblock_submit_bios(&list);
 768                                bio_cnt = 0;
 769                        }
 770
 771                        bio = iblock_get_bio(cmd, block_lba, sg_num, op,
 772                                             op_flags);
 773                        if (!bio)
 774                                goto fail_put_bios;
 775
 776                        refcount_inc(&ibr->pending);
 777                        bio_list_add(&list, bio);
 778                        bio_cnt++;
 779                }
 780
 781                /* Always in 512 byte units for Linux/Block */
 782                block_lba += sg->length >> SECTOR_SHIFT;
 783                sg_num--;
 784        }
 785
 786        if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
 787                rc = iblock_alloc_bip(cmd, bio, &prot_miter);
 788                if (rc)
 789                        goto fail_put_bios;
 790        }
 791
 792        iblock_submit_bios(&list);
 793        iblock_complete_cmd(cmd);
 794        return 0;
 795
 796fail_put_bios:
 797        while ((bio = bio_list_pop(&list)))
 798                bio_put(bio);
 799fail_free_ibr:
 800        kfree(ibr);
 801fail:
 802        return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 803}
 804
 805static sector_t iblock_get_blocks(struct se_device *dev)
 806{
 807        struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 808        struct block_device *bd = ib_dev->ibd_bd;
 809        struct request_queue *q = bdev_get_queue(bd);
 810
 811        return iblock_emulate_read_cap_with_block_size(dev, bd, q);
 812}
 813
 814static sector_t iblock_get_alignment_offset_lbas(struct se_device *dev)
 815{
 816        struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 817        struct block_device *bd = ib_dev->ibd_bd;
 818        int ret;
 819
 820        ret = bdev_alignment_offset(bd);
 821        if (ret == -1)
 822                return 0;
 823
 824        /* convert offset-bytes to offset-lbas */
 825        return ret / bdev_logical_block_size(bd);
 826}
 827
 828static unsigned int iblock_get_lbppbe(struct se_device *dev)
 829{
 830        struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 831        struct block_device *bd = ib_dev->ibd_bd;
 832        int logs_per_phys = bdev_physical_block_size(bd) / bdev_logical_block_size(bd);
 833
 834        return ilog2(logs_per_phys);
 835}
 836
 837static unsigned int iblock_get_io_min(struct se_device *dev)
 838{
 839        struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 840        struct block_device *bd = ib_dev->ibd_bd;
 841
 842        return bdev_io_min(bd);
 843}
 844
 845static unsigned int iblock_get_io_opt(struct se_device *dev)
 846{
 847        struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 848        struct block_device *bd = ib_dev->ibd_bd;
 849
 850        return bdev_io_opt(bd);
 851}
 852
 853static struct sbc_ops iblock_sbc_ops = {
 854        .execute_rw             = iblock_execute_rw,
 855        .execute_sync_cache     = iblock_execute_sync_cache,
 856        .execute_write_same     = iblock_execute_write_same,
 857        .execute_unmap          = iblock_execute_unmap,
 858};
 859
 860static sense_reason_t
 861iblock_parse_cdb(struct se_cmd *cmd)
 862{
 863        return sbc_parse_cdb(cmd, &iblock_sbc_ops);
 864}
 865
 866static bool iblock_get_write_cache(struct se_device *dev)
 867{
 868        struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 869        struct block_device *bd = ib_dev->ibd_bd;
 870        struct request_queue *q = bdev_get_queue(bd);
 871
 872        return test_bit(QUEUE_FLAG_WC, &q->queue_flags);
 873}
 874
 875static const struct target_backend_ops iblock_ops = {
 876        .name                   = "iblock",
 877        .inquiry_prod           = "IBLOCK",
 878        .inquiry_rev            = IBLOCK_VERSION,
 879        .owner                  = THIS_MODULE,
 880        .attach_hba             = iblock_attach_hba,
 881        .detach_hba             = iblock_detach_hba,
 882        .alloc_device           = iblock_alloc_device,
 883        .configure_device       = iblock_configure_device,
 884        .destroy_device         = iblock_destroy_device,
 885        .free_device            = iblock_free_device,
 886        .parse_cdb              = iblock_parse_cdb,
 887        .set_configfs_dev_params = iblock_set_configfs_dev_params,
 888        .show_configfs_dev_params = iblock_show_configfs_dev_params,
 889        .get_device_type        = sbc_get_device_type,
 890        .get_blocks             = iblock_get_blocks,
 891        .get_alignment_offset_lbas = iblock_get_alignment_offset_lbas,
 892        .get_lbppbe             = iblock_get_lbppbe,
 893        .get_io_min             = iblock_get_io_min,
 894        .get_io_opt             = iblock_get_io_opt,
 895        .get_write_cache        = iblock_get_write_cache,
 896        .tb_dev_attrib_attrs    = sbc_attrib_attrs,
 897};
 898
 899static int __init iblock_module_init(void)
 900{
 901        return transport_backend_register(&iblock_ops);
 902}
 903
 904static void __exit iblock_module_exit(void)
 905{
 906        target_backend_unregister(&iblock_ops);
 907}
 908
 909MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin");
 910MODULE_AUTHOR("nab@Linux-iSCSI.org");
 911MODULE_LICENSE("GPL");
 912
 913module_init(iblock_module_init);
 914module_exit(iblock_module_exit);
 915