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