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