drivers/target/target_core_iblock.c

   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.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 #include <target/target_core_backend_configfs.h>
  45
  46 #include "target_core_iblock.h"
  47
  48 #define IBLOCK_MAX_BIO_PER_TASK  32     /* max # of bios to submit at a time */
  49 #define IBLOCK_BIO_POOL_SIZE    128
  50
  51 static inline struct iblock_dev *IBLOCK_DEV(struct se_device *dev)
  52 {
  53         return container_of(dev, struct iblock_dev, dev);
  54 }
  55
  56
  57 static struct se_subsystem_api iblock_template;
  58
  59 /*      iblock_attach_hba(): (Part of se_subsystem_api_t template)
  60  *
  61  *
  62  */
  63 static int iblock_attach_hba(struct se_hba *hba, u32 host_id)
  64 {
  65         pr_debug("CORE_HBA[%d] - TCM iBlock HBA Driver %s on"
  66                 " Generic Target Core Stack %s\n", hba->hba_id,
  67                 IBLOCK_VERSION, TARGET_CORE_MOD_VERSION);
  68         return 0;
  69 }
  70
  71 static void iblock_detach_hba(struct se_hba *hba)
  72 {
  73 }
  74
  75 static struct se_device *iblock_alloc_device(struct se_hba *hba, const char *name)
  76 {
  77         struct iblock_dev *ib_dev = NULL;
  78
  79         ib_dev = kzalloc(sizeof(struct iblock_dev), GFP_KERNEL);
  80         if (!ib_dev) {
  81                 pr_err("Unable to allocate struct iblock_dev\n");
  82                 return NULL;
  83         }
  84
  85         pr_debug( "IBLOCK: Allocated ib_dev for %s\n", name);
  86
  87         return &ib_dev->dev;
  88 }
  89
  90 static int iblock_configure_device(struct se_device *dev)
  91 {
  92         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
  93         struct request_queue *q;
  94         struct block_device *bd = NULL;
  95         struct blk_integrity *bi;
  96         fmode_t mode;
  97         int ret = -ENOMEM;
  98
  99         if (!(ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)) {
 100                 pr_err("Missing udev_path= parameters for IBLOCK\n");
 101                 return -EINVAL;
 102         }
 103
 104         ib_dev->ibd_bio_set = bioset_create(IBLOCK_BIO_POOL_SIZE, 0);
 105         if (!ib_dev->ibd_bio_set) {
 106                 pr_err("IBLOCK: Unable to create bioset\n");
 107                 goto out;
 108         }
 109
 110         pr_debug( "IBLOCK: Claiming struct block_device: %s\n",
 111                         ib_dev->ibd_udev_path);
 112
 113         mode = FMODE_READ|FMODE_EXCL;
 114         if (!ib_dev->ibd_readonly)
 115                 mode |= FMODE_WRITE;
 116
 117         bd = blkdev_get_by_path(ib_dev->ibd_udev_path, mode, ib_dev);
 118         if (IS_ERR(bd)) {
 119                 ret = PTR_ERR(bd);
 120                 goto out_free_bioset;
 121         }
 122         ib_dev->ibd_bd = bd;
 123
 124         q = bdev_get_queue(bd);
 125
 126         dev->dev_attrib.hw_block_size = bdev_logical_block_size(bd);
 127         dev->dev_attrib.hw_max_sectors = queue_max_hw_sectors(q);
 128         dev->dev_attrib.hw_queue_depth = q->nr_requests;
 129
 130         /*
 131          * Check if the underlying struct block_device request_queue supports
 132          * the QUEUE_FLAG_DISCARD bit for UNMAP/WRITE_SAME in SCSI + TRIM
 133          * in ATA and we need to set TPE=1
 134          */
 135         if (blk_queue_discard(q)) {
 136                 dev->dev_attrib.max_unmap_lba_count =
 137                                 q->limits.max_discard_sectors;
 138
 139                 /*
 140                  * Currently hardcoded to 1 in Linux/SCSI code..
 141                  */
 142                 dev->dev_attrib.max_unmap_block_desc_count = 1;
 143                 dev->dev_attrib.unmap_granularity =
 144                                 q->limits.discard_granularity >> 9;
 145                 dev->dev_attrib.unmap_granularity_alignment =
 146                                 q->limits.discard_alignment;
 147
 148                 pr_debug("IBLOCK: BLOCK Discard support available,"
 149                                 " disabled by default\n");
 150         }
 151         /*
 152          * Enable write same emulation for IBLOCK and use 0xFFFF as
 153          * the smaller WRITE_SAME(10) only has a two-byte block count.
 154          */
 155         dev->dev_attrib.max_write_same_len = 0xFFFF;
 156
 157         if (blk_queue_nonrot(q))
 158                 dev->dev_attrib.is_nonrot = 1;
 159
 160         bi = bdev_get_integrity(bd);
 161         if (bi) {
 162                 struct bio_set *bs = ib_dev->ibd_bio_set;
 163
 164                 if (!strcmp(bi->name, "T10-DIF-TYPE3-IP") ||
 165                     !strcmp(bi->name, "T10-DIF-TYPE1-IP")) {
 166                         pr_err("IBLOCK export of blk_integrity: %s not"
 167                                " supported\n", bi->name);
 168                         ret = -ENOSYS;
 169                         goto out_blkdev_put;
 170                 }
 171
 172                 if (!strcmp(bi->name, "T10-DIF-TYPE3-CRC")) {
 173                         dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE3_PROT;
 174                 } else if (!strcmp(bi->name, "T10-DIF-TYPE1-CRC")) {
 175                         dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE1_PROT;
 176                 }
 177
 178                 if (dev->dev_attrib.pi_prot_type) {
 179                         if (bioset_integrity_create(bs, IBLOCK_BIO_POOL_SIZE) < 0) {
 180                                 pr_err("Unable to allocate bioset for PI\n");
 181                                 ret = -ENOMEM;
 182                                 goto out_blkdev_put;
 183                         }
 184                         pr_debug("IBLOCK setup BIP bs->bio_integrity_pool: %p\n",
 185                                  bs->bio_integrity_pool);
 186                 }
 187                 dev->dev_attrib.hw_pi_prot_type = dev->dev_attrib.pi_prot_type;
 188         }
 189
 190         return 0;
 191
 192 out_blkdev_put:
 193         blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
 194 out_free_bioset:
 195         bioset_free(ib_dev->ibd_bio_set);
 196         ib_dev->ibd_bio_set = NULL;
 197 out:
 198         return ret;
 199 }
 200
 201 static void iblock_free_device(struct se_device *dev)
 202 {
 203         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 204
 205         if (ib_dev->ibd_bd != NULL)
 206                 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
 207         if (ib_dev->ibd_bio_set != NULL)
 208                 bioset_free(ib_dev->ibd_bio_set);
 209
 210         kfree(ib_dev);
 211 }
 212
 213 static unsigned long long iblock_emulate_read_cap_with_block_size(
 214         struct se_device *dev,
 215         struct block_device *bd,
 216         struct request_queue *q)
 217 {
 218         unsigned long long blocks_long = (div_u64(i_size_read(bd->bd_inode),
 219                                         bdev_logical_block_size(bd)) - 1);
 220         u32 block_size = bdev_logical_block_size(bd);
 221
 222         if (block_size == dev->dev_attrib.block_size)
 223                 return blocks_long;
 224
 225         switch (block_size) {
 226         case 4096:
 227                 switch (dev->dev_attrib.block_size) {
 228                 case 2048:
 229                         blocks_long <<= 1;
 230                         break;
 231                 case 1024:
 232                         blocks_long <<= 2;
 233                         break;
 234                 case 512:
 235                         blocks_long <<= 3;
 236                 default:
 237                         break;
 238                 }
 239                 break;
 240         case 2048:
 241                 switch (dev->dev_attrib.block_size) {
 242                 case 4096:
 243                         blocks_long >>= 1;
 244                         break;
 245                 case 1024:
 246                         blocks_long <<= 1;
 247                         break;
 248                 case 512:
 249                         blocks_long <<= 2;
 250                         break;
 251                 default:
 252                         break;
 253                 }
 254                 break;
 255         case 1024:
 256                 switch (dev->dev_attrib.block_size) {
 257                 case 4096:
 258                         blocks_long >>= 2;
 259                         break;
 260                 case 2048:
 261                         blocks_long >>= 1;
 262                         break;
 263                 case 512:
 264                         blocks_long <<= 1;
 265                         break;
 266                 default:
 267                         break;
 268                 }
 269                 break;
 270         case 512:
 271                 switch (dev->dev_attrib.block_size) {
 272                 case 4096:
 273                         blocks_long >>= 3;
 274                         break;
 275                 case 2048:
 276                         blocks_long >>= 2;
 277                         break;
 278                 case 1024:
 279                         blocks_long >>= 1;
 280                         break;
 281                 default:
 282                         break;
 283                 }
 284                 break;
 285         default:
 286                 break;
 287         }
 288
 289         return blocks_long;
 290 }
 291
 292 static void iblock_complete_cmd(struct se_cmd *cmd)
 293 {
 294         struct iblock_req *ibr = cmd->priv;
 295         u8 status;
 296
 297         if (!atomic_dec_and_test(&ibr->pending))
 298                 return;
 299
 300         if (atomic_read(&ibr->ib_bio_err_cnt))
 301                 status = SAM_STAT_CHECK_CONDITION;
 302         else
 303                 status = SAM_STAT_GOOD;
 304
 305         target_complete_cmd(cmd, status);
 306         kfree(ibr);
 307 }
 308
 309 static void iblock_bio_done(struct bio *bio, int err)
 310 {
 311         struct se_cmd *cmd = bio->bi_private;
 312         struct iblock_req *ibr = cmd->priv;
 313
 314         /*
 315          * Set -EIO if !BIO_UPTODATE and the passed is still err=0
 316          */
 317         if (!test_bit(BIO_UPTODATE, &bio->bi_flags) && !err)
 318                 err = -EIO;
 319
 320         if (err != 0) {
 321                 pr_err("test_bit(BIO_UPTODATE) failed for bio: %p,"
 322                         " err: %d\n", bio, err);
 323                 /*
 324                  * Bump the ib_bio_err_cnt and release bio.
 325                  */
 326                 atomic_inc(&ibr->ib_bio_err_cnt);
 327                 smp_mb__after_atomic();
 328         }
 329
 330         bio_put(bio);
 331
 332         iblock_complete_cmd(cmd);
 333 }
 334
 335 static struct bio *
 336 iblock_get_bio(struct se_cmd *cmd, sector_t lba, u32 sg_num)
 337 {
 338         struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
 339         struct bio *bio;
 340
 341         /*
 342          * Only allocate as many vector entries as the bio code allows us to,
 343          * we'll loop later on until we have handled the whole request.
 344          */
 345         if (sg_num > BIO_MAX_PAGES)
 346                 sg_num = BIO_MAX_PAGES;
 347
 348         bio = bio_alloc_bioset(GFP_NOIO, sg_num, ib_dev->ibd_bio_set);
 349         if (!bio) {
 350                 pr_err("Unable to allocate memory for bio\n");
 351                 return NULL;
 352         }
 353
 354         bio->bi_bdev = ib_dev->ibd_bd;
 355         bio->bi_private = cmd;
 356         bio->bi_end_io = &iblock_bio_done;
 357         bio->bi_iter.bi_sector = lba;
 358
 359         return bio;
 360 }
 361
 362 static void iblock_submit_bios(struct bio_list *list, int rw)
 363 {
 364         struct blk_plug plug;
 365         struct bio *bio;
 366
 367         blk_start_plug(&plug);
 368         while ((bio = bio_list_pop(list)))
 369                 submit_bio(rw, bio);
 370         blk_finish_plug(&plug);
 371 }
 372
 373 static void iblock_end_io_flush(struct bio *bio, int err)
 374 {
 375         struct se_cmd *cmd = bio->bi_private;
 376
 377         if (err)
 378                 pr_err("IBLOCK: cache flush failed: %d\n", err);
 379
 380         if (cmd) {
 381                 if (err)
 382                         target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
 383                 else
 384                         target_complete_cmd(cmd, SAM_STAT_GOOD);
 385         }
 386
 387         bio_put(bio);
 388 }
 389
 390 /*
 391  * Implement SYCHRONIZE CACHE.  Note that we can't handle lba ranges and must
 392  * always flush the whole cache.
 393  */
 394 static sense_reason_t
 395 iblock_execute_sync_cache(struct se_cmd *cmd)
 396 {
 397         struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
 398         int immed = (cmd->t_task_cdb[1] & 0x2);
 399         struct bio *bio;
 400
 401         /*
 402          * If the Immediate bit is set, queue up the GOOD response
 403          * for this SYNCHRONIZE_CACHE op.
 404          */
 405         if (immed)
 406                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 407
 408         bio = bio_alloc(GFP_KERNEL, 0);
 409         bio->bi_end_io = iblock_end_io_flush;
 410         bio->bi_bdev = ib_dev->ibd_bd;
 411         if (!immed)
 412                 bio->bi_private = cmd;
 413         submit_bio(WRITE_FLUSH, bio);
 414         return 0;
 415 }
 416
 417 static sense_reason_t
 418 iblock_do_unmap(struct se_cmd *cmd, void *priv,
 419                 sector_t lba, sector_t nolb)
 420 {
 421         struct block_device *bdev = priv;
 422         int ret;
 423
 424         ret = blkdev_issue_discard(bdev, lba, nolb, GFP_KERNEL, 0);
 425         if (ret < 0) {
 426                 pr_err("blkdev_issue_discard() failed: %d\n", ret);
 427                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 428         }
 429
 430         return 0;
 431 }
 432
 433 static sense_reason_t
 434 iblock_execute_unmap(struct se_cmd *cmd)
 435 {
 436         struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
 437
 438         return sbc_execute_unmap(cmd, iblock_do_unmap, bdev);
 439 }
 440
 441 static sense_reason_t
 442 iblock_execute_write_same_unmap(struct se_cmd *cmd)
 443 {
 444         struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
 445         sector_t lba = cmd->t_task_lba;
 446         sector_t nolb = sbc_get_write_same_sectors(cmd);
 447         int ret;
 448
 449         ret = iblock_do_unmap(cmd, bdev, lba, nolb);
 450         if (ret)
 451                 return ret;
 452
 453         target_complete_cmd(cmd, GOOD);
 454         return 0;
 455 }
 456
 457 static sense_reason_t
 458 iblock_execute_write_same(struct se_cmd *cmd)
 459 {
 460         struct iblock_req *ibr;
 461         struct scatterlist *sg;
 462         struct bio *bio;
 463         struct bio_list list;
 464         sector_t block_lba = cmd->t_task_lba;
 465         sector_t sectors = sbc_get_write_same_sectors(cmd);
 466
 467         sg = &cmd->t_data_sg[0];
 468
 469         if (cmd->t_data_nents > 1 ||
 470             sg->length != cmd->se_dev->dev_attrib.block_size) {
 471                 pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
 472                         " block_size: %u\n", cmd->t_data_nents, sg->length,
 473                         cmd->se_dev->dev_attrib.block_size);
 474                 return TCM_INVALID_CDB_FIELD;
 475         }
 476
 477         ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
 478         if (!ibr)
 479                 goto fail;
 480         cmd->priv = ibr;
 481
 482         bio = iblock_get_bio(cmd, block_lba, 1);
 483         if (!bio)
 484                 goto fail_free_ibr;
 485
 486         bio_list_init(&list);
 487         bio_list_add(&list, bio);
 488
 489         atomic_set(&ibr->pending, 1);
 490
 491         while (sectors) {
 492                 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
 493                                 != sg->length) {
 494
 495                         bio = iblock_get_bio(cmd, block_lba, 1);
 496                         if (!bio)
 497                                 goto fail_put_bios;
 498
 499                         atomic_inc(&ibr->pending);
 500                         bio_list_add(&list, bio);
 501                 }
 502
 503                 /* Always in 512 byte units for Linux/Block */
 504                 block_lba += sg->length >> IBLOCK_LBA_SHIFT;
 505                 sectors -= 1;
 506         }
 507
 508         iblock_submit_bios(&list, WRITE);
 509         return 0;
 510
 511 fail_put_bios:
 512         while ((bio = bio_list_pop(&list)))
 513                 bio_put(bio);
 514 fail_free_ibr:
 515         kfree(ibr);
 516 fail:
 517         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 518 }
 519
 520 enum {
 521         Opt_udev_path, Opt_readonly, Opt_force, Opt_err
 522 };
 523
 524 static match_table_t tokens = {
 525         {Opt_udev_path, "udev_path=%s"},
 526         {Opt_readonly, "readonly=%d"},
 527         {Opt_force, "force=%d"},
 528         {Opt_err, NULL}
 529 };
 530
 531 static ssize_t iblock_set_configfs_dev_params(struct se_device *dev,
 532                 const char *page, ssize_t count)
 533 {
 534         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 535         char *orig, *ptr, *arg_p, *opts;
 536         substring_t args[MAX_OPT_ARGS];
 537         int ret = 0, token;
 538         unsigned long tmp_readonly;
 539
 540         opts = kstrdup(page, GFP_KERNEL);
 541         if (!opts)
 542                 return -ENOMEM;
 543
 544         orig = opts;
 545
 546         while ((ptr = strsep(&opts, ",\n")) != NULL) {
 547                 if (!*ptr)
 548                         continue;
 549
 550                 token = match_token(ptr, tokens, args);
 551                 switch (token) {
 552                 case Opt_udev_path:
 553                         if (ib_dev->ibd_bd) {
 554                                 pr_err("Unable to set udev_path= while"
 555                                         " ib_dev->ibd_bd exists\n");
 556                                 ret = -EEXIST;
 557                                 goto out;
 558                         }
 559                         if (match_strlcpy(ib_dev->ibd_udev_path, &args[0],
 560                                 SE_UDEV_PATH_LEN) == 0) {
 561                                 ret = -EINVAL;
 562                                 break;
 563                         }
 564                         pr_debug("IBLOCK: Referencing UDEV path: %s\n",
 565                                         ib_dev->ibd_udev_path);
 566                         ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH;
 567                         break;
 568                 case Opt_readonly:
 569                         arg_p = match_strdup(&args[0]);
 570                         if (!arg_p) {
 571                                 ret = -ENOMEM;
 572                                 break;
 573                         }
 574                         ret = kstrtoul(arg_p, 0, &tmp_readonly);
 575                         kfree(arg_p);
 576                         if (ret < 0) {
 577                                 pr_err("kstrtoul() failed for"
 578                                                 " readonly=\n");
 579                                 goto out;
 580                         }
 581                         ib_dev->ibd_readonly = tmp_readonly;
 582                         pr_debug("IBLOCK: readonly: %d\n", ib_dev->ibd_readonly);
 583                         break;
 584                 case Opt_force:
 585                         break;
 586                 default:
 587                         break;
 588                 }
 589         }
 590
 591 out:
 592         kfree(orig);
 593         return (!ret) ? count : ret;
 594 }
 595
 596 static ssize_t iblock_show_configfs_dev_params(struct se_device *dev, char *b)
 597 {
 598         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 599         struct block_device *bd = ib_dev->ibd_bd;
 600         char buf[BDEVNAME_SIZE];
 601         ssize_t bl = 0;
 602
 603         if (bd)
 604                 bl += sprintf(b + bl, "iBlock device: %s",
 605                                 bdevname(bd, buf));
 606         if (ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)
 607                 bl += sprintf(b + bl, "  UDEV PATH: %s",
 608                                 ib_dev->ibd_udev_path);
 609         bl += sprintf(b + bl, "  readonly: %d\n", ib_dev->ibd_readonly);
 610
 611         bl += sprintf(b + bl, "        ");
 612         if (bd) {
 613                 bl += sprintf(b + bl, "Major: %d Minor: %d  %s\n",
 614                         MAJOR(bd->bd_dev), MINOR(bd->bd_dev), (!bd->bd_contains) ?
 615                         "" : (bd->bd_holder == ib_dev) ?
 616                         "CLAIMED: IBLOCK" : "CLAIMED: OS");
 617         } else {
 618                 bl += sprintf(b + bl, "Major: 0 Minor: 0\n");
 619         }
 620
 621         return bl;
 622 }
 623
 624 static int
 625 iblock_alloc_bip(struct se_cmd *cmd, struct bio *bio)
 626 {
 627         struct se_device *dev = cmd->se_dev;
 628         struct blk_integrity *bi;
 629         struct bio_integrity_payload *bip;
 630         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 631         struct scatterlist *sg;
 632         int i, rc;
 633
 634         bi = bdev_get_integrity(ib_dev->ibd_bd);
 635         if (!bi) {
 636                 pr_err("Unable to locate bio_integrity\n");
 637                 return -ENODEV;
 638         }
 639
 640         bip = bio_integrity_alloc(bio, GFP_NOIO, cmd->t_prot_nents);
 641         if (!bip) {
 642                 pr_err("Unable to allocate bio_integrity_payload\n");
 643                 return -ENOMEM;
 644         }
 645
 646         bip->bip_iter.bi_size = (cmd->data_length / dev->dev_attrib.block_size) *
 647                          dev->prot_length;
 648         bip->bip_iter.bi_sector = bio->bi_iter.bi_sector;
 649
 650         pr_debug("IBLOCK BIP Size: %u Sector: %llu\n", bip->bip_iter.bi_size,
 651                  (unsigned long long)bip->bip_iter.bi_sector);
 652
 653         for_each_sg(cmd->t_prot_sg, sg, cmd->t_prot_nents, i) {
 654
 655                 rc = bio_integrity_add_page(bio, sg_page(sg), sg->length,
 656                                             sg->offset);
 657                 if (rc != sg->length) {
 658                         pr_err("bio_integrity_add_page() failed; %d\n", rc);
 659                         return -ENOMEM;
 660                 }
 661
 662                 pr_debug("Added bio integrity page: %p length: %d offset; %d\n",
 663                          sg_page(sg), sg->length, sg->offset);
 664         }
 665
 666         return 0;
 667 }
 668
 669 static sense_reason_t
 670 iblock_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 671                   enum dma_data_direction data_direction)
 672 {
 673         struct se_device *dev = cmd->se_dev;
 674         struct iblock_req *ibr;
 675         struct bio *bio, *bio_start;
 676         struct bio_list list;
 677         struct scatterlist *sg;
 678         u32 sg_num = sgl_nents;
 679         sector_t block_lba;
 680         unsigned bio_cnt;
 681         int rw = 0;
 682         int i;
 683
 684         if (data_direction == DMA_TO_DEVICE) {
 685                 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 686                 struct request_queue *q = bdev_get_queue(ib_dev->ibd_bd);
 687                 /*
 688                  * Force writethrough using WRITE_FUA if a volatile write cache
 689                  * is not enabled, or if initiator set the Force Unit Access bit.
 690                  */
 691                 if (q->flush_flags & REQ_FUA) {
 692                         if (cmd->se_cmd_flags & SCF_FUA)
 693                                 rw = WRITE_FUA;
 694                         else if (!(q->flush_flags & REQ_FLUSH))
 695                                 rw = WRITE_FUA;
 696                         else
 697                                 rw = WRITE;
 698                 } else {
 699                         rw = WRITE;
 700                 }
 701         } else {
 702                 rw = READ;
 703         }
 704
 705         /*
 706          * Convert the blocksize advertised to the initiator to the 512 byte
 707          * units unconditionally used by the Linux block layer.
 708          */
 709         if (dev->dev_attrib.block_size == 4096)
 710                 block_lba = (cmd->t_task_lba << 3);
 711         else if (dev->dev_attrib.block_size == 2048)
 712                 block_lba = (cmd->t_task_lba << 2);
 713         else if (dev->dev_attrib.block_size == 1024)
 714                 block_lba = (cmd->t_task_lba << 1);
 715         else if (dev->dev_attrib.block_size == 512)
 716                 block_lba = cmd->t_task_lba;
 717         else {
 718                 pr_err("Unsupported SCSI -> BLOCK LBA conversion:"
 719                                 " %u\n", dev->dev_attrib.block_size);
 720                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 721         }
 722
 723         ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
 724         if (!ibr)
 725                 goto fail;
 726         cmd->priv = ibr;
 727
 728         if (!sgl_nents) {
 729                 atomic_set(&ibr->pending, 1);
 730                 iblock_complete_cmd(cmd);
 731                 return 0;
 732         }
 733
 734         bio = iblock_get_bio(cmd, block_lba, sgl_nents);
 735         if (!bio)
 736                 goto fail_free_ibr;
 737
 738         bio_start = bio;
 739         bio_list_init(&list);
 740         bio_list_add(&list, bio);
 741
 742         atomic_set(&ibr->pending, 2);
 743         bio_cnt = 1;
 744
 745         for_each_sg(sgl, sg, sgl_nents, i) {
 746                 /*
 747                  * XXX: if the length the device accepts is shorter than the
 748                  *      length of the S/G list entry this will cause and
 749                  *      endless loop.  Better hope no driver uses huge pages.
 750                  */
 751                 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
 752                                 != sg->length) {
 753                         if (bio_cnt >= IBLOCK_MAX_BIO_PER_TASK) {
 754                                 iblock_submit_bios(&list, rw);
 755                                 bio_cnt = 0;
 756                         }
 757
 758                         bio = iblock_get_bio(cmd, block_lba, sg_num);
 759                         if (!bio)
 760                                 goto fail_put_bios;
 761
 762                         atomic_inc(&ibr->pending);
 763                         bio_list_add(&list, bio);
 764                         bio_cnt++;
 765                 }
 766
 767                 /* Always in 512 byte units for Linux/Block */
 768                 block_lba += sg->length >> IBLOCK_LBA_SHIFT;
 769                 sg_num--;
 770         }
 771
 772         if (cmd->prot_type) {
 773                 int rc = iblock_alloc_bip(cmd, bio_start);
 774                 if (rc)
 775                         goto fail_put_bios;
 776         }
 777
 778         iblock_submit_bios(&list, rw);
 779         iblock_complete_cmd(cmd);
 780         return 0;
 781
 782 fail_put_bios:
 783         while ((bio = bio_list_pop(&list)))
 784                 bio_put(bio);
 785 fail_free_ibr:
 786         kfree(ibr);
 787 fail:
 788         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 789 }
 790
 791 static sector_t iblock_get_blocks(struct se_device *dev)
 792 {
 793         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 794         struct block_device *bd = ib_dev->ibd_bd;
 795         struct request_queue *q = bdev_get_queue(bd);
 796
 797         return iblock_emulate_read_cap_with_block_size(dev, bd, q);
 798 }
 799
 800 static sector_t iblock_get_alignment_offset_lbas(struct se_device *dev)
 801 {
 802         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 803         struct block_device *bd = ib_dev->ibd_bd;
 804         int ret;
 805
 806         ret = bdev_alignment_offset(bd);
 807         if (ret == -1)
 808                 return 0;
 809
 810         /* convert offset-bytes to offset-lbas */
 811         return ret / bdev_logical_block_size(bd);
 812 }
 813
 814 static unsigned int iblock_get_lbppbe(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 logs_per_phys = bdev_physical_block_size(bd) / bdev_logical_block_size(bd);
 819
 820         return ilog2(logs_per_phys);
 821 }
 822
 823 static unsigned int iblock_get_io_min(struct se_device *dev)
 824 {
 825         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 826         struct block_device *bd = ib_dev->ibd_bd;
 827
 828         return bdev_io_min(bd);
 829 }
 830
 831 static unsigned int iblock_get_io_opt(struct se_device *dev)
 832 {
 833         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 834         struct block_device *bd = ib_dev->ibd_bd;
 835
 836         return bdev_io_opt(bd);
 837 }
 838
 839 static struct sbc_ops iblock_sbc_ops = {
 840         .execute_rw             = iblock_execute_rw,
 841         .execute_sync_cache     = iblock_execute_sync_cache,
 842         .execute_write_same     = iblock_execute_write_same,
 843         .execute_write_same_unmap = iblock_execute_write_same_unmap,
 844         .execute_unmap          = iblock_execute_unmap,
 845 };
 846
 847 static sense_reason_t
 848 iblock_parse_cdb(struct se_cmd *cmd)
 849 {
 850         return sbc_parse_cdb(cmd, &iblock_sbc_ops);
 851 }
 852
 853 static bool iblock_get_write_cache(struct se_device *dev)
 854 {
 855         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 856         struct block_device *bd = ib_dev->ibd_bd;
 857         struct request_queue *q = bdev_get_queue(bd);
 858
 859         return q->flush_flags & REQ_FLUSH;
 860 }
 861
 862 DEF_TB_DEFAULT_ATTRIBS(iblock);
 863
 864 static struct configfs_attribute *iblock_backend_dev_attrs[] = {
 865         &iblock_dev_attrib_emulate_model_alias.attr,
 866         &iblock_dev_attrib_emulate_dpo.attr,
 867         &iblock_dev_attrib_emulate_fua_write.attr,
 868         &iblock_dev_attrib_emulate_fua_read.attr,
 869         &iblock_dev_attrib_emulate_write_cache.attr,
 870         &iblock_dev_attrib_emulate_ua_intlck_ctrl.attr,
 871         &iblock_dev_attrib_emulate_tas.attr,
 872         &iblock_dev_attrib_emulate_tpu.attr,
 873         &iblock_dev_attrib_emulate_tpws.attr,
 874         &iblock_dev_attrib_emulate_caw.attr,
 875         &iblock_dev_attrib_emulate_3pc.attr,
 876         &iblock_dev_attrib_pi_prot_type.attr,
 877         &iblock_dev_attrib_hw_pi_prot_type.attr,
 878         &iblock_dev_attrib_pi_prot_format.attr,
 879         &iblock_dev_attrib_enforce_pr_isids.attr,
 880         &iblock_dev_attrib_is_nonrot.attr,
 881         &iblock_dev_attrib_emulate_rest_reord.attr,
 882         &iblock_dev_attrib_force_pr_aptpl.attr,
 883         &iblock_dev_attrib_hw_block_size.attr,
 884         &iblock_dev_attrib_block_size.attr,
 885         &iblock_dev_attrib_hw_max_sectors.attr,
 886         &iblock_dev_attrib_optimal_sectors.attr,
 887         &iblock_dev_attrib_hw_queue_depth.attr,
 888         &iblock_dev_attrib_queue_depth.attr,
 889         &iblock_dev_attrib_max_unmap_lba_count.attr,
 890         &iblock_dev_attrib_max_unmap_block_desc_count.attr,
 891         &iblock_dev_attrib_unmap_granularity.attr,
 892         &iblock_dev_attrib_unmap_granularity_alignment.attr,
 893         &iblock_dev_attrib_max_write_same_len.attr,
 894         NULL,
 895 };
 896
 897 static struct se_subsystem_api iblock_template = {
 898         .name                   = "iblock",
 899         .inquiry_prod           = "IBLOCK",
 900         .inquiry_rev            = IBLOCK_VERSION,
 901         .owner                  = THIS_MODULE,
 902         .transport_type         = TRANSPORT_PLUGIN_VHBA_PDEV,
 903         .attach_hba             = iblock_attach_hba,
 904         .detach_hba             = iblock_detach_hba,
 905         .alloc_device           = iblock_alloc_device,
 906         .configure_device       = iblock_configure_device,
 907         .free_device            = iblock_free_device,
 908         .parse_cdb              = iblock_parse_cdb,
 909         .set_configfs_dev_params = iblock_set_configfs_dev_params,
 910         .show_configfs_dev_params = iblock_show_configfs_dev_params,
 911         .get_device_type        = sbc_get_device_type,
 912         .get_blocks             = iblock_get_blocks,
 913         .get_alignment_offset_lbas = iblock_get_alignment_offset_lbas,
 914         .get_lbppbe             = iblock_get_lbppbe,
 915         .get_io_min             = iblock_get_io_min,
 916         .get_io_opt             = iblock_get_io_opt,
 917         .get_write_cache        = iblock_get_write_cache,
 918 };
 919
 920 static int __init iblock_module_init(void)
 921 {
 922         struct target_backend_cits *tbc = &iblock_template.tb_cits;
 923
 924         target_core_setup_sub_cits(&iblock_template);
 925         tbc->tb_dev_attrib_cit.ct_attrs = iblock_backend_dev_attrs;
 926
 927         return transport_subsystem_register(&iblock_template);
 928 }
 929
 930 static void __exit iblock_module_exit(void)
 931 {
 932         transport_subsystem_release(&iblock_template);
 933 }
 934
 935 MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin");
 936 MODULE_AUTHOR("nab@Linux-iSCSI.org");
 937 MODULE_LICENSE("GPL");
 938
 939 module_init(iblock_module_init);
 940 module_exit(iblock_module_exit);