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         ib_dev->ibd_bio_set = bioset_create(IBLOCK_BIO_POOL_SIZE, 0, BIOSET_NEED_BVECS);
  98         if (!ib_dev->ibd_bio_set) {
  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_free(ib_dev->ibd_bio_set);
 178         ib_dev->ibd_bio_set = NULL;
 179 out:
 180         return ret;
 181 }
 182
 183 static void iblock_dev_call_rcu(struct rcu_head *p)
 184 {
 185         struct se_device *dev = container_of(p, struct se_device, rcu_head);
 186         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 187
 188         kfree(ib_dev);
 189 }
 190
 191 static void iblock_free_device(struct se_device *dev)
 192 {
 193         call_rcu(&dev->rcu_head, iblock_dev_call_rcu);
 194 }
 195
 196 static void iblock_destroy_device(struct se_device *dev)
 197 {
 198         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 199
 200         if (ib_dev->ibd_bd != NULL)
 201                 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
 202         if (ib_dev->ibd_bio_set != NULL)
 203                 bioset_free(ib_dev->ibd_bio_set);
 204 }
 205
 206 static unsigned long long iblock_emulate_read_cap_with_block_size(
 207         struct se_device *dev,
 208         struct block_device *bd,
 209         struct request_queue *q)
 210 {
 211         unsigned long long blocks_long = (div_u64(i_size_read(bd->bd_inode),
 212                                         bdev_logical_block_size(bd)) - 1);
 213         u32 block_size = bdev_logical_block_size(bd);
 214
 215         if (block_size == dev->dev_attrib.block_size)
 216                 return blocks_long;
 217
 218         switch (block_size) {
 219         case 4096:
 220                 switch (dev->dev_attrib.block_size) {
 221                 case 2048:
 222                         blocks_long <<= 1;
 223                         break;
 224                 case 1024:
 225                         blocks_long <<= 2;
 226                         break;
 227                 case 512:
 228                         blocks_long <<= 3;
 229                 default:
 230                         break;
 231                 }
 232                 break;
 233         case 2048:
 234                 switch (dev->dev_attrib.block_size) {
 235                 case 4096:
 236                         blocks_long >>= 1;
 237                         break;
 238                 case 1024:
 239                         blocks_long <<= 1;
 240                         break;
 241                 case 512:
 242                         blocks_long <<= 2;
 243                         break;
 244                 default:
 245                         break;
 246                 }
 247                 break;
 248         case 1024:
 249                 switch (dev->dev_attrib.block_size) {
 250                 case 4096:
 251                         blocks_long >>= 2;
 252                         break;
 253                 case 2048:
 254                         blocks_long >>= 1;
 255                         break;
 256                 case 512:
 257                         blocks_long <<= 1;
 258                         break;
 259                 default:
 260                         break;
 261                 }
 262                 break;
 263         case 512:
 264                 switch (dev->dev_attrib.block_size) {
 265                 case 4096:
 266                         blocks_long >>= 3;
 267                         break;
 268                 case 2048:
 269                         blocks_long >>= 2;
 270                         break;
 271                 case 1024:
 272                         blocks_long >>= 1;
 273                         break;
 274                 default:
 275                         break;
 276                 }
 277                 break;
 278         default:
 279                 break;
 280         }
 281
 282         return blocks_long;
 283 }
 284
 285 static void iblock_complete_cmd(struct se_cmd *cmd)
 286 {
 287         struct iblock_req *ibr = cmd->priv;
 288         u8 status;
 289
 290         if (!refcount_dec_and_test(&ibr->pending))
 291                 return;
 292
 293         if (atomic_read(&ibr->ib_bio_err_cnt))
 294                 status = SAM_STAT_CHECK_CONDITION;
 295         else
 296                 status = SAM_STAT_GOOD;
 297
 298         target_complete_cmd(cmd, status);
 299         kfree(ibr);
 300 }
 301
 302 static void iblock_bio_done(struct bio *bio)
 303 {
 304         struct se_cmd *cmd = bio->bi_private;
 305         struct iblock_req *ibr = cmd->priv;
 306
 307         if (bio->bi_status) {
 308                 pr_err("bio error: %p,  err: %d\n", bio, bio->bi_status);
 309                 /*
 310                  * Bump the ib_bio_err_cnt and release bio.
 311                  */
 312                 atomic_inc(&ibr->ib_bio_err_cnt);
 313                 smp_mb__after_atomic();
 314         }
 315
 316         bio_put(bio);
 317
 318         iblock_complete_cmd(cmd);
 319 }
 320
 321 static struct bio *
 322 iblock_get_bio(struct se_cmd *cmd, sector_t lba, u32 sg_num, int op,
 323                int op_flags)
 324 {
 325         struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
 326         struct bio *bio;
 327
 328         /*
 329          * Only allocate as many vector entries as the bio code allows us to,
 330          * we'll loop later on until we have handled the whole request.
 331          */
 332         if (sg_num > BIO_MAX_PAGES)
 333                 sg_num = BIO_MAX_PAGES;
 334
 335         bio = bio_alloc_bioset(GFP_NOIO, sg_num, ib_dev->ibd_bio_set);
 336         if (!bio) {
 337                 pr_err("Unable to allocate memory for bio\n");
 338                 return NULL;
 339         }
 340
 341         bio->bi_bdev = ib_dev->ibd_bd;
 342         bio->bi_private = cmd;
 343         bio->bi_end_io = &iblock_bio_done;
 344         bio->bi_iter.bi_sector = lba;
 345         bio_set_op_attrs(bio, op, op_flags);
 346
 347         return bio;
 348 }
 349
 350 static void iblock_submit_bios(struct bio_list *list)
 351 {
 352         struct blk_plug plug;
 353         struct bio *bio;
 354
 355         blk_start_plug(&plug);
 356         while ((bio = bio_list_pop(list)))
 357                 submit_bio(bio);
 358         blk_finish_plug(&plug);
 359 }
 360
 361 static void iblock_end_io_flush(struct bio *bio)
 362 {
 363         struct se_cmd *cmd = bio->bi_private;
 364
 365         if (bio->bi_status)
 366                 pr_err("IBLOCK: cache flush failed: %d\n", bio->bi_status);
 367
 368         if (cmd) {
 369                 if (bio->bi_status)
 370                         target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
 371                 else
 372                         target_complete_cmd(cmd, SAM_STAT_GOOD);
 373         }
 374
 375         bio_put(bio);
 376 }
 377
 378 /*
 379  * Implement SYCHRONIZE CACHE.  Note that we can't handle lba ranges and must
 380  * always flush the whole cache.
 381  */
 382 static sense_reason_t
 383 iblock_execute_sync_cache(struct se_cmd *cmd)
 384 {
 385         struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
 386         int immed = (cmd->t_task_cdb[1] & 0x2);
 387         struct bio *bio;
 388
 389         /*
 390          * If the Immediate bit is set, queue up the GOOD response
 391          * for this SYNCHRONIZE_CACHE op.
 392          */
 393         if (immed)
 394                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 395
 396         bio = bio_alloc(GFP_KERNEL, 0);
 397         bio->bi_end_io = iblock_end_io_flush;
 398         bio->bi_bdev = ib_dev->ibd_bd;
 399         bio->bi_opf = REQ_OP_WRITE | REQ_PREFLUSH;
 400         if (!immed)
 401                 bio->bi_private = cmd;
 402         submit_bio(bio);
 403         return 0;
 404 }
 405
 406 static sense_reason_t
 407 iblock_execute_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
 408 {
 409         struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
 410         struct se_device *dev = cmd->se_dev;
 411         int ret;
 412
 413         ret = blkdev_issue_discard(bdev,
 414                                    target_to_linux_sector(dev, lba),
 415                                    target_to_linux_sector(dev,  nolb),
 416                                    GFP_KERNEL, 0);
 417         if (ret < 0) {
 418                 pr_err("blkdev_issue_discard() failed: %d\n", ret);
 419                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 420         }
 421
 422         return 0;
 423 }
 424
 425 static sense_reason_t
 426 iblock_execute_zero_out(struct block_device *bdev, struct se_cmd *cmd)
 427 {
 428         struct se_device *dev = cmd->se_dev;
 429         struct scatterlist *sg = &cmd->t_data_sg[0];
 430         unsigned char *buf, zero = 0x00, *p = &zero;
 431         int rc, ret;
 432
 433         buf = kmap(sg_page(sg)) + sg->offset;
 434         if (!buf)
 435                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 436         /*
 437          * Fall back to block_execute_write_same() slow-path if
 438          * incoming WRITE_SAME payload does not contain zeros.
 439          */
 440         rc = memcmp(buf, p, cmd->data_length);
 441         kunmap(sg_page(sg));
 442
 443         if (rc)
 444                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 445
 446         ret = blkdev_issue_zeroout(bdev,
 447                                 target_to_linux_sector(dev, cmd->t_task_lba),
 448                                 target_to_linux_sector(dev,
 449                                         sbc_get_write_same_sectors(cmd)),
 450                                 GFP_KERNEL, false);
 451         if (ret)
 452                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 453
 454         target_complete_cmd(cmd, GOOD);
 455         return 0;
 456 }
 457
 458 static sense_reason_t
 459 iblock_execute_write_same(struct se_cmd *cmd)
 460 {
 461         struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
 462         struct iblock_req *ibr;
 463         struct scatterlist *sg;
 464         struct bio *bio;
 465         struct bio_list list;
 466         struct se_device *dev = cmd->se_dev;
 467         sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba);
 468         sector_t sectors = target_to_linux_sector(dev,
 469                                         sbc_get_write_same_sectors(cmd));
 470
 471         if (cmd->prot_op) {
 472                 pr_err("WRITE_SAME: Protection information with IBLOCK"
 473                        " backends not supported\n");
 474                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 475         }
 476         sg = &cmd->t_data_sg[0];
 477
 478         if (cmd->t_data_nents > 1 ||
 479             sg->length != cmd->se_dev->dev_attrib.block_size) {
 480                 pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
 481                         " block_size: %u\n", cmd->t_data_nents, sg->length,
 482                         cmd->se_dev->dev_attrib.block_size);
 483                 return TCM_INVALID_CDB_FIELD;
 484         }
 485
 486         if (bdev_write_zeroes_sectors(bdev)) {
 487                 if (!iblock_execute_zero_out(bdev, cmd))
 488                         return 0;
 489         }
 490
 491         ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
 492         if (!ibr)
 493                 goto fail;
 494         cmd->priv = ibr;
 495
 496         bio = iblock_get_bio(cmd, block_lba, 1, REQ_OP_WRITE, 0);
 497         if (!bio)
 498                 goto fail_free_ibr;
 499
 500         bio_list_init(&list);
 501         bio_list_add(&list, bio);
 502
 503         refcount_set(&ibr->pending, 1);
 504
 505         while (sectors) {
 506                 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
 507                                 != sg->length) {
 508
 509                         bio = iblock_get_bio(cmd, block_lba, 1, REQ_OP_WRITE,
 510                                              0);
 511                         if (!bio)
 512                                 goto fail_put_bios;
 513
 514                         refcount_inc(&ibr->pending);
 515                         bio_list_add(&list, bio);
 516                 }
 517
 518                 /* Always in 512 byte units for Linux/Block */
 519                 block_lba += sg->length >> IBLOCK_LBA_SHIFT;
 520                 sectors -= 1;
 521         }
 522
 523         iblock_submit_bios(&list);
 524         return 0;
 525
 526 fail_put_bios:
 527         while ((bio = bio_list_pop(&list)))
 528                 bio_put(bio);
 529 fail_free_ibr:
 530         kfree(ibr);
 531 fail:
 532         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 533 }
 534
 535 enum {
 536         Opt_udev_path, Opt_readonly, Opt_force, Opt_err
 537 };
 538
 539 static match_table_t tokens = {
 540         {Opt_udev_path, "udev_path=%s"},
 541         {Opt_readonly, "readonly=%d"},
 542         {Opt_force, "force=%d"},
 543         {Opt_err, NULL}
 544 };
 545
 546 static ssize_t iblock_set_configfs_dev_params(struct se_device *dev,
 547                 const char *page, ssize_t count)
 548 {
 549         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 550         char *orig, *ptr, *arg_p, *opts;
 551         substring_t args[MAX_OPT_ARGS];
 552         int ret = 0, token;
 553         unsigned long tmp_readonly;
 554
 555         opts = kstrdup(page, GFP_KERNEL);
 556         if (!opts)
 557                 return -ENOMEM;
 558
 559         orig = opts;
 560
 561         while ((ptr = strsep(&opts, ",\n")) != NULL) {
 562                 if (!*ptr)
 563                         continue;
 564
 565                 token = match_token(ptr, tokens, args);
 566                 switch (token) {
 567                 case Opt_udev_path:
 568                         if (ib_dev->ibd_bd) {
 569                                 pr_err("Unable to set udev_path= while"
 570                                         " ib_dev->ibd_bd exists\n");
 571                                 ret = -EEXIST;
 572                                 goto out;
 573                         }
 574                         if (match_strlcpy(ib_dev->ibd_udev_path, &args[0],
 575                                 SE_UDEV_PATH_LEN) == 0) {
 576                                 ret = -EINVAL;
 577                                 break;
 578                         }
 579                         pr_debug("IBLOCK: Referencing UDEV path: %s\n",
 580                                         ib_dev->ibd_udev_path);
 581                         ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH;
 582                         break;
 583                 case Opt_readonly:
 584                         arg_p = match_strdup(&args[0]);
 585                         if (!arg_p) {
 586                                 ret = -ENOMEM;
 587                                 break;
 588                         }
 589                         ret = kstrtoul(arg_p, 0, &tmp_readonly);
 590                         kfree(arg_p);
 591                         if (ret < 0) {
 592                                 pr_err("kstrtoul() failed for"
 593                                                 " readonly=\n");
 594                                 goto out;
 595                         }
 596                         ib_dev->ibd_readonly = tmp_readonly;
 597                         pr_debug("IBLOCK: readonly: %d\n", ib_dev->ibd_readonly);
 598                         break;
 599                 case Opt_force:
 600                         break;
 601                 default:
 602                         break;
 603                 }
 604         }
 605
 606 out:
 607         kfree(orig);
 608         return (!ret) ? count : ret;
 609 }
 610
 611 static ssize_t iblock_show_configfs_dev_params(struct se_device *dev, char *b)
 612 {
 613         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 614         struct block_device *bd = ib_dev->ibd_bd;
 615         char buf[BDEVNAME_SIZE];
 616         ssize_t bl = 0;
 617
 618         if (bd)
 619                 bl += sprintf(b + bl, "iBlock device: %s",
 620                                 bdevname(bd, buf));
 621         if (ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)
 622                 bl += sprintf(b + bl, "  UDEV PATH: %s",
 623                                 ib_dev->ibd_udev_path);
 624         bl += sprintf(b + bl, "  readonly: %d\n", ib_dev->ibd_readonly);
 625
 626         bl += sprintf(b + bl, "        ");
 627         if (bd) {
 628                 bl += sprintf(b + bl, "Major: %d Minor: %d  %s\n",
 629                         MAJOR(bd->bd_dev), MINOR(bd->bd_dev), (!bd->bd_contains) ?
 630                         "" : (bd->bd_holder == ib_dev) ?
 631                         "CLAIMED: IBLOCK" : "CLAIMED: OS");
 632         } else {
 633                 bl += sprintf(b + bl, "Major: 0 Minor: 0\n");
 634         }
 635
 636         return bl;
 637 }
 638
 639 static int
 640 iblock_alloc_bip(struct se_cmd *cmd, struct bio *bio)
 641 {
 642         struct se_device *dev = cmd->se_dev;
 643         struct blk_integrity *bi;
 644         struct bio_integrity_payload *bip;
 645         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 646         struct scatterlist *sg;
 647         int i, rc;
 648
 649         bi = bdev_get_integrity(ib_dev->ibd_bd);
 650         if (!bi) {
 651                 pr_err("Unable to locate bio_integrity\n");
 652                 return -ENODEV;
 653         }
 654
 655         bip = bio_integrity_alloc(bio, GFP_NOIO, cmd->t_prot_nents);
 656         if (IS_ERR(bip)) {
 657                 pr_err("Unable to allocate bio_integrity_payload\n");
 658                 return PTR_ERR(bip);
 659         }
 660
 661         bip->bip_iter.bi_size = (cmd->data_length / dev->dev_attrib.block_size) *
 662                          dev->prot_length;
 663         bip->bip_iter.bi_sector = bio->bi_iter.bi_sector;
 664
 665         pr_debug("IBLOCK BIP Size: %u Sector: %llu\n", bip->bip_iter.bi_size,
 666                  (unsigned long long)bip->bip_iter.bi_sector);
 667
 668         for_each_sg(cmd->t_prot_sg, sg, cmd->t_prot_nents, i) {
 669
 670                 rc = bio_integrity_add_page(bio, sg_page(sg), sg->length,
 671                                             sg->offset);
 672                 if (rc != sg->length) {
 673                         pr_err("bio_integrity_add_page() failed; %d\n", rc);
 674                         return -ENOMEM;
 675                 }
 676
 677                 pr_debug("Added bio integrity page: %p length: %d offset; %d\n",
 678                          sg_page(sg), sg->length, sg->offset);
 679         }
 680
 681         return 0;
 682 }
 683
 684 static sense_reason_t
 685 iblock_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 686                   enum dma_data_direction data_direction)
 687 {
 688         struct se_device *dev = cmd->se_dev;
 689         sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba);
 690         struct iblock_req *ibr;
 691         struct bio *bio, *bio_start;
 692         struct bio_list list;
 693         struct scatterlist *sg;
 694         u32 sg_num = sgl_nents;
 695         unsigned bio_cnt;
 696         int i, op, op_flags = 0;
 697
 698         if (data_direction == DMA_TO_DEVICE) {
 699                 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 700                 struct request_queue *q = bdev_get_queue(ib_dev->ibd_bd);
 701                 /*
 702                  * Force writethrough using REQ_FUA if a volatile write cache
 703                  * is not enabled, or if initiator set the Force Unit Access bit.
 704                  */
 705                 op = REQ_OP_WRITE;
 706                 if (test_bit(QUEUE_FLAG_FUA, &q->queue_flags)) {
 707                         if (cmd->se_cmd_flags & SCF_FUA)
 708                                 op_flags = REQ_FUA;
 709                         else if (!test_bit(QUEUE_FLAG_WC, &q->queue_flags))
 710                                 op_flags = REQ_FUA;
 711                 }
 712         } else {
 713                 op = REQ_OP_READ;
 714         }
 715
 716         ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
 717         if (!ibr)
 718                 goto fail;
 719         cmd->priv = ibr;
 720
 721         if (!sgl_nents) {
 722                 refcount_set(&ibr->pending, 1);
 723                 iblock_complete_cmd(cmd);
 724                 return 0;
 725         }
 726
 727         bio = iblock_get_bio(cmd, block_lba, sgl_nents, op, op_flags);
 728         if (!bio)
 729                 goto fail_free_ibr;
 730
 731         bio_start = bio;
 732         bio_list_init(&list);
 733         bio_list_add(&list, bio);
 734
 735         refcount_set(&ibr->pending, 2);
 736         bio_cnt = 1;
 737
 738         for_each_sg(sgl, sg, sgl_nents, i) {
 739                 /*
 740                  * XXX: if the length the device accepts is shorter than the
 741                  *      length of the S/G list entry this will cause and
 742                  *      endless loop.  Better hope no driver uses huge pages.
 743                  */
 744                 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
 745                                 != sg->length) {
 746                         if (bio_cnt >= IBLOCK_MAX_BIO_PER_TASK) {
 747                                 iblock_submit_bios(&list);
 748                                 bio_cnt = 0;
 749                         }
 750
 751                         bio = iblock_get_bio(cmd, block_lba, sg_num, op,
 752                                              op_flags);
 753                         if (!bio)
 754                                 goto fail_put_bios;
 755
 756                         refcount_inc(&ibr->pending);
 757                         bio_list_add(&list, bio);
 758                         bio_cnt++;
 759                 }
 760
 761                 /* Always in 512 byte units for Linux/Block */
 762                 block_lba += sg->length >> IBLOCK_LBA_SHIFT;
 763                 sg_num--;
 764         }
 765
 766         if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
 767                 int rc = iblock_alloc_bip(cmd, bio_start);
 768                 if (rc)
 769                         goto fail_put_bios;
 770         }
 771
 772         iblock_submit_bios(&list);
 773         iblock_complete_cmd(cmd);
 774         return 0;
 775
 776 fail_put_bios:
 777         while ((bio = bio_list_pop(&list)))
 778                 bio_put(bio);
 779 fail_free_ibr:
 780         kfree(ibr);
 781 fail:
 782         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 783 }
 784
 785 static sector_t iblock_get_blocks(struct se_device *dev)
 786 {
 787         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 788         struct block_device *bd = ib_dev->ibd_bd;
 789         struct request_queue *q = bdev_get_queue(bd);
 790
 791         return iblock_emulate_read_cap_with_block_size(dev, bd, q);
 792 }
 793
 794 static sector_t iblock_get_alignment_offset_lbas(struct se_device *dev)
 795 {
 796         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 797         struct block_device *bd = ib_dev->ibd_bd;
 798         int ret;
 799
 800         ret = bdev_alignment_offset(bd);
 801         if (ret == -1)
 802                 return 0;
 803
 804         /* convert offset-bytes to offset-lbas */
 805         return ret / bdev_logical_block_size(bd);
 806 }
 807
 808 static unsigned int iblock_get_lbppbe(struct se_device *dev)
 809 {
 810         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 811         struct block_device *bd = ib_dev->ibd_bd;
 812         int logs_per_phys = bdev_physical_block_size(bd) / bdev_logical_block_size(bd);
 813
 814         return ilog2(logs_per_phys);
 815 }
 816
 817 static unsigned int iblock_get_io_min(struct se_device *dev)
 818 {
 819         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 820         struct block_device *bd = ib_dev->ibd_bd;
 821
 822         return bdev_io_min(bd);
 823 }
 824
 825 static unsigned int iblock_get_io_opt(struct se_device *dev)
 826 {
 827         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 828         struct block_device *bd = ib_dev->ibd_bd;
 829
 830         return bdev_io_opt(bd);
 831 }
 832
 833 static struct sbc_ops iblock_sbc_ops = {
 834         .execute_rw             = iblock_execute_rw,
 835         .execute_sync_cache     = iblock_execute_sync_cache,
 836         .execute_write_same     = iblock_execute_write_same,
 837         .execute_unmap          = iblock_execute_unmap,
 838 };
 839
 840 static sense_reason_t
 841 iblock_parse_cdb(struct se_cmd *cmd)
 842 {
 843         return sbc_parse_cdb(cmd, &iblock_sbc_ops);
 844 }
 845
 846 static bool iblock_get_write_cache(struct se_device *dev)
 847 {
 848         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 849         struct block_device *bd = ib_dev->ibd_bd;
 850         struct request_queue *q = bdev_get_queue(bd);
 851
 852         return test_bit(QUEUE_FLAG_WC, &q->queue_flags);
 853 }
 854
 855 static const struct target_backend_ops iblock_ops = {
 856         .name                   = "iblock",
 857         .inquiry_prod           = "IBLOCK",
 858         .inquiry_rev            = IBLOCK_VERSION,
 859         .owner                  = THIS_MODULE,
 860         .attach_hba             = iblock_attach_hba,
 861         .detach_hba             = iblock_detach_hba,
 862         .alloc_device           = iblock_alloc_device,
 863         .configure_device       = iblock_configure_device,
 864         .destroy_device         = iblock_destroy_device,
 865         .free_device            = iblock_free_device,
 866         .parse_cdb              = iblock_parse_cdb,
 867         .set_configfs_dev_params = iblock_set_configfs_dev_params,
 868         .show_configfs_dev_params = iblock_show_configfs_dev_params,
 869         .get_device_type        = sbc_get_device_type,
 870         .get_blocks             = iblock_get_blocks,
 871         .get_alignment_offset_lbas = iblock_get_alignment_offset_lbas,
 872         .get_lbppbe             = iblock_get_lbppbe,
 873         .get_io_min             = iblock_get_io_min,
 874         .get_io_opt             = iblock_get_io_opt,
 875         .get_write_cache        = iblock_get_write_cache,
 876         .tb_dev_attrib_attrs    = sbc_attrib_attrs,
 877 };
 878
 879 static int __init iblock_module_init(void)
 880 {
 881         return transport_backend_register(&iblock_ops);
 882 }
 883
 884 static void __exit iblock_module_exit(void)
 885 {
 886         target_backend_unregister(&iblock_ops);
 887 }
 888
 889 MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin");
 890 MODULE_AUTHOR("nab@Linux-iSCSI.org");
 891 MODULE_LICENSE("GPL");
 892
 893 module_init(iblock_module_init);
 894 module_exit(iblock_module_exit);