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         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
 174 out_blkdev_put:
 175         blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
 176 out_free_bioset:
 177         bioset_exit(&ib_dev->ibd_bio_set);
 178 out:
 179         return ret;
 180 }
 181
 182 static 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
 190 static void iblock_free_device(struct se_device *dev)
 191 {
 192         call_rcu(&dev->rcu_head, iblock_dev_call_rcu);
 193 }
 194
 195 static 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
 204 static 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
 283 static 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
 300 static 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
 319 static struct bio *
 320 iblock_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
 348 static 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
 359 static 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  */
 380 static sense_reason_t
 381 iblock_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
 404 static sense_reason_t
 405 iblock_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
 423 static sense_reason_t
 424 iblock_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
 456 static sense_reason_t
 457 iblock_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
 524 fail_put_bios:
 525         while ((bio = bio_list_pop(&list)))
 526                 bio_put(bio);
 527 fail_free_ibr:
 528         kfree(ibr);
 529 fail:
 530         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 531 }
 532
 533 enum {
 534         Opt_udev_path, Opt_readonly, Opt_force, Opt_err
 535 };
 536
 537 static 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
 544 static 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
 604 out:
 605         kfree(orig);
 606         return (!ret) ? count : ret;
 607 }
 608
 609 static 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
 637 static int
 638 iblock_alloc_bip(struct se_cmd *cmd, struct bio *bio)
 639 {
 640         struct se_device *dev = cmd->se_dev;
 641         struct blk_integrity *bi;
 642         struct bio_integrity_payload *bip;
 643         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 644         struct scatterlist *sg;
 645         int i, rc;
 646
 647         bi = bdev_get_integrity(ib_dev->ibd_bd);
 648         if (!bi) {
 649                 pr_err("Unable to locate bio_integrity\n");
 650                 return -ENODEV;
 651         }
 652
 653         bip = bio_integrity_alloc(bio, GFP_NOIO, cmd->t_prot_nents);
 654         if (IS_ERR(bip)) {
 655                 pr_err("Unable to allocate bio_integrity_payload\n");
 656                 return PTR_ERR(bip);
 657         }
 658
 659         bip->bip_iter.bi_size = (cmd->data_length / dev->dev_attrib.block_size) *
 660                          dev->prot_length;
 661         bip->bip_iter.bi_sector = bio->bi_iter.bi_sector;
 662
 663         pr_debug("IBLOCK BIP Size: %u Sector: %llu\n", bip->bip_iter.bi_size,
 664                  (unsigned long long)bip->bip_iter.bi_sector);
 665
 666         for_each_sg(cmd->t_prot_sg, sg, cmd->t_prot_nents, i) {
 667
 668                 rc = bio_integrity_add_page(bio, sg_page(sg), sg->length,
 669                                             sg->offset);
 670                 if (rc != sg->length) {
 671                         pr_err("bio_integrity_add_page() failed; %d\n", rc);
 672                         return -ENOMEM;
 673                 }
 674
 675                 pr_debug("Added bio integrity page: %p length: %d offset; %d\n",
 676                          sg_page(sg), sg->length, sg->offset);
 677         }
 678
 679         return 0;
 680 }
 681
 682 static sense_reason_t
 683 iblock_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 684                   enum dma_data_direction data_direction)
 685 {
 686         struct se_device *dev = cmd->se_dev;
 687         sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba);
 688         struct iblock_req *ibr;
 689         struct bio *bio, *bio_start;
 690         struct bio_list list;
 691         struct scatterlist *sg;
 692         u32 sg_num = sgl_nents;
 693         unsigned bio_cnt;
 694         int i, op, op_flags = 0;
 695
 696         if (data_direction == DMA_TO_DEVICE) {
 697                 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 698                 struct request_queue *q = bdev_get_queue(ib_dev->ibd_bd);
 699                 /*
 700                  * Force writethrough using REQ_FUA if a volatile write cache
 701                  * is not enabled, or if initiator set the Force Unit Access bit.
 702                  */
 703                 op = REQ_OP_WRITE;
 704                 if (test_bit(QUEUE_FLAG_FUA, &q->queue_flags)) {
 705                         if (cmd->se_cmd_flags & SCF_FUA)
 706                                 op_flags = REQ_FUA;
 707                         else if (!test_bit(QUEUE_FLAG_WC, &q->queue_flags))
 708                                 op_flags = REQ_FUA;
 709                 }
 710         } else {
 711                 op = REQ_OP_READ;
 712         }
 713
 714         ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
 715         if (!ibr)
 716                 goto fail;
 717         cmd->priv = ibr;
 718
 719         if (!sgl_nents) {
 720                 refcount_set(&ibr->pending, 1);
 721                 iblock_complete_cmd(cmd);
 722                 return 0;
 723         }
 724
 725         bio = iblock_get_bio(cmd, block_lba, sgl_nents, op, op_flags);
 726         if (!bio)
 727                 goto fail_free_ibr;
 728
 729         bio_start = bio;
 730         bio_list_init(&list);
 731         bio_list_add(&list, bio);
 732
 733         refcount_set(&ibr->pending, 2);
 734         bio_cnt = 1;
 735
 736         for_each_sg(sgl, sg, sgl_nents, i) {
 737                 /*
 738                  * XXX: if the length the device accepts is shorter than the
 739                  *      length of the S/G list entry this will cause and
 740                  *      endless loop.  Better hope no driver uses huge pages.
 741                  */
 742                 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
 743                                 != sg->length) {
 744                         if (bio_cnt >= IBLOCK_MAX_BIO_PER_TASK) {
 745                                 iblock_submit_bios(&list);
 746                                 bio_cnt = 0;
 747                         }
 748
 749                         bio = iblock_get_bio(cmd, block_lba, sg_num, op,
 750                                              op_flags);
 751                         if (!bio)
 752                                 goto fail_put_bios;
 753
 754                         refcount_inc(&ibr->pending);
 755                         bio_list_add(&list, bio);
 756                         bio_cnt++;
 757                 }
 758
 759                 /* Always in 512 byte units for Linux/Block */
 760                 block_lba += sg->length >> SECTOR_SHIFT;
 761                 sg_num--;
 762         }
 763
 764         if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
 765                 int rc = iblock_alloc_bip(cmd, bio_start);
 766                 if (rc)
 767                         goto fail_put_bios;
 768         }
 769
 770         iblock_submit_bios(&list);
 771         iblock_complete_cmd(cmd);
 772         return 0;
 773
 774 fail_put_bios:
 775         while ((bio = bio_list_pop(&list)))
 776                 bio_put(bio);
 777 fail_free_ibr:
 778         kfree(ibr);
 779 fail:
 780         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 781 }
 782
 783 static sector_t iblock_get_blocks(struct se_device *dev)
 784 {
 785         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 786         struct block_device *bd = ib_dev->ibd_bd;
 787         struct request_queue *q = bdev_get_queue(bd);
 788
 789         return iblock_emulate_read_cap_with_block_size(dev, bd, q);
 790 }
 791
 792 static sector_t iblock_get_alignment_offset_lbas(struct se_device *dev)
 793 {
 794         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 795         struct block_device *bd = ib_dev->ibd_bd;
 796         int ret;
 797
 798         ret = bdev_alignment_offset(bd);
 799         if (ret == -1)
 800                 return 0;
 801
 802         /* convert offset-bytes to offset-lbas */
 803         return ret / bdev_logical_block_size(bd);
 804 }
 805
 806 static unsigned int iblock_get_lbppbe(struct se_device *dev)
 807 {
 808         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 809         struct block_device *bd = ib_dev->ibd_bd;
 810         int logs_per_phys = bdev_physical_block_size(bd) / bdev_logical_block_size(bd);
 811
 812         return ilog2(logs_per_phys);
 813 }
 814
 815 static unsigned int iblock_get_io_min(struct se_device *dev)
 816 {
 817         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 818         struct block_device *bd = ib_dev->ibd_bd;
 819
 820         return bdev_io_min(bd);
 821 }
 822
 823 static unsigned int iblock_get_io_opt(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_opt(bd);
 829 }
 830
 831 static struct sbc_ops iblock_sbc_ops = {
 832         .execute_rw             = iblock_execute_rw,
 833         .execute_sync_cache     = iblock_execute_sync_cache,
 834         .execute_write_same     = iblock_execute_write_same,
 835         .execute_unmap          = iblock_execute_unmap,
 836 };
 837
 838 static sense_reason_t
 839 iblock_parse_cdb(struct se_cmd *cmd)
 840 {
 841         return sbc_parse_cdb(cmd, &iblock_sbc_ops);
 842 }
 843
 844 static bool iblock_get_write_cache(struct se_device *dev)
 845 {
 846         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 847         struct block_device *bd = ib_dev->ibd_bd;
 848         struct request_queue *q = bdev_get_queue(bd);
 849
 850         return test_bit(QUEUE_FLAG_WC, &q->queue_flags);
 851 }
 852
 853 static const struct target_backend_ops iblock_ops = {
 854         .name                   = "iblock",
 855         .inquiry_prod           = "IBLOCK",
 856         .inquiry_rev            = IBLOCK_VERSION,
 857         .owner                  = THIS_MODULE,
 858         .attach_hba             = iblock_attach_hba,
 859         .detach_hba             = iblock_detach_hba,
 860         .alloc_device           = iblock_alloc_device,
 861         .configure_device       = iblock_configure_device,
 862         .destroy_device         = iblock_destroy_device,
 863         .free_device            = iblock_free_device,
 864         .parse_cdb              = iblock_parse_cdb,
 865         .set_configfs_dev_params = iblock_set_configfs_dev_params,
 866         .show_configfs_dev_params = iblock_show_configfs_dev_params,
 867         .get_device_type        = sbc_get_device_type,
 868         .get_blocks             = iblock_get_blocks,
 869         .get_alignment_offset_lbas = iblock_get_alignment_offset_lbas,
 870         .get_lbppbe             = iblock_get_lbppbe,
 871         .get_io_min             = iblock_get_io_min,
 872         .get_io_opt             = iblock_get_io_opt,
 873         .get_write_cache        = iblock_get_write_cache,
 874         .tb_dev_attrib_attrs    = sbc_attrib_attrs,
 875 };
 876
 877 static int __init iblock_module_init(void)
 878 {
 879         return transport_backend_register(&iblock_ops);
 880 }
 881
 882 static void __exit iblock_module_exit(void)
 883 {
 884         target_backend_unregister(&iblock_ops);
 885 }
 886
 887 MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin");
 888 MODULE_AUTHOR("nab@Linux-iSCSI.org");
 889 MODULE_LICENSE("GPL");
 890
 891 module_init(iblock_module_init);
 892 module_exit(iblock_module_exit);