drivers/target/target_core_iblock.c

   1 /*******************************************************************************
   2  * Filename:  target_core_iblock.c
   3  *
   4  * This file contains the Storage Engine  <-> Linux BlockIO transport
   5  * specific functions.
   6  *
   7  * (c) Copyright 2003-2013 Datera, Inc.
   8  *
   9  * Nicholas A. Bellinger <nab@kernel.org>
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  24  *
  25  ******************************************************************************/
  26
  27 #include <linux/string.h>
  28 #include <linux/parser.h>
  29 #include <linux/timer.h>
  30 #include <linux/fs.h>
  31 #include <linux/blkdev.h>
  32 #include <linux/slab.h>
  33 #include <linux/spinlock.h>
  34 #include <linux/bio.h>
  35 #include <linux/genhd.h>
  36 #include <linux/file.h>
  37 #include <linux/module.h>
  38 #include <scsi/scsi.h>
  39 #include <scsi/scsi_host.h>
  40 #include <asm/unaligned.h>
  41
  42 #include <target/target_core_base.h>
  43 #include <target/target_core_backend.h>
  44
  45 #include "target_core_iblock.h"
  46
  47 #define IBLOCK_MAX_BIO_PER_TASK  32     /* max # of bios to submit at a time */
  48 #define IBLOCK_BIO_POOL_SIZE    128
  49
  50 static inline struct iblock_dev *IBLOCK_DEV(struct se_device *dev)
  51 {
  52         return container_of(dev, struct iblock_dev, dev);
  53 }
  54
  55
  56 static struct se_subsystem_api iblock_template;
  57
  58 /*      iblock_attach_hba(): (Part of se_subsystem_api_t template)
  59  *
  60  *
  61  */
  62 static int iblock_attach_hba(struct se_hba *hba, u32 host_id)
  63 {
  64         pr_debug("CORE_HBA[%d] - TCM iBlock HBA Driver %s on"
  65                 " Generic Target Core Stack %s\n", hba->hba_id,
  66                 IBLOCK_VERSION, TARGET_CORE_MOD_VERSION);
  67         return 0;
  68 }
  69
  70 static void iblock_detach_hba(struct se_hba *hba)
  71 {
  72 }
  73
  74 static struct se_device *iblock_alloc_device(struct se_hba *hba, const char *name)
  75 {
  76         struct iblock_dev *ib_dev = NULL;
  77
  78         ib_dev = kzalloc(sizeof(struct iblock_dev), GFP_KERNEL);
  79         if (!ib_dev) {
  80                 pr_err("Unable to allocate struct iblock_dev\n");
  81                 return NULL;
  82         }
  83
  84         pr_debug( "IBLOCK: Allocated ib_dev for %s\n", name);
  85
  86         return &ib_dev->dev;
  87 }
  88
  89 static int iblock_configure_device(struct se_device *dev)
  90 {
  91         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
  92         struct request_queue *q;
  93         struct block_device *bd = NULL;
  94         struct blk_integrity *bi;
  95         fmode_t mode;
  96         int ret = -ENOMEM;
  97
  98         if (!(ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)) {
  99                 pr_err("Missing udev_path= parameters for IBLOCK\n");
 100                 return -EINVAL;
 101         }
 102
 103         ib_dev->ibd_bio_set = bioset_create(IBLOCK_BIO_POOL_SIZE, 0);
 104         if (!ib_dev->ibd_bio_set) {
 105                 pr_err("IBLOCK: Unable to create bioset\n");
 106                 goto out;
 107         }
 108
 109         pr_debug( "IBLOCK: Claiming struct block_device: %s\n",
 110                         ib_dev->ibd_udev_path);
 111
 112         mode = FMODE_READ|FMODE_EXCL;
 113         if (!ib_dev->ibd_readonly)
 114                 mode |= FMODE_WRITE;
 115
 116         bd = blkdev_get_by_path(ib_dev->ibd_udev_path, mode, ib_dev);
 117         if (IS_ERR(bd)) {
 118                 ret = PTR_ERR(bd);
 119                 goto out_free_bioset;
 120         }
 121         ib_dev->ibd_bd = bd;
 122
 123         q = bdev_get_queue(bd);
 124
 125         dev->dev_attrib.hw_block_size = bdev_logical_block_size(bd);
 126         dev->dev_attrib.hw_max_sectors = UINT_MAX;
 127         dev->dev_attrib.hw_queue_depth = q->nr_requests;
 128
 129         /*
 130          * Check if the underlying struct block_device request_queue supports
 131          * the QUEUE_FLAG_DISCARD bit for UNMAP/WRITE_SAME in SCSI + TRIM
 132          * in ATA and we need to set TPE=1
 133          */
 134         if (blk_queue_discard(q)) {
 135                 dev->dev_attrib.max_unmap_lba_count =
 136                                 q->limits.max_discard_sectors;
 137
 138                 /*
 139                  * Currently hardcoded to 1 in Linux/SCSI code..
 140                  */
 141                 dev->dev_attrib.max_unmap_block_desc_count = 1;
 142                 dev->dev_attrib.unmap_granularity =
 143                                 q->limits.discard_granularity >> 9;
 144                 dev->dev_attrib.unmap_granularity_alignment =
 145                                 q->limits.discard_alignment;
 146
 147                 pr_debug("IBLOCK: BLOCK Discard support available,"
 148                                 " disabled by default\n");
 149         }
 150         /*
 151          * Enable write same emulation for IBLOCK and use 0xFFFF as
 152          * the smaller WRITE_SAME(10) only has a two-byte block count.
 153          */
 154         dev->dev_attrib.max_write_same_len = 0xFFFF;
 155
 156         if (blk_queue_nonrot(q))
 157                 dev->dev_attrib.is_nonrot = 1;
 158
 159         bi = bdev_get_integrity(bd);
 160         if (bi) {
 161                 struct bio_set *bs = ib_dev->ibd_bio_set;
 162
 163                 if (!strcmp(bi->name, "T10-DIF-TYPE3-IP") ||
 164                     !strcmp(bi->name, "T10-DIF-TYPE1-IP")) {
 165                         pr_err("IBLOCK export of blk_integrity: %s not"
 166                                " supported\n", bi->name);
 167                         ret = -ENOSYS;
 168                         goto out_blkdev_put;
 169                 }
 170
 171                 if (!strcmp(bi->name, "T10-DIF-TYPE3-CRC")) {
 172                         dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE3_PROT;
 173                 } else if (!strcmp(bi->name, "T10-DIF-TYPE1-CRC")) {
 174                         dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE1_PROT;
 175                 }
 176
 177                 if (dev->dev_attrib.pi_prot_type) {
 178                         if (bioset_integrity_create(bs, IBLOCK_BIO_POOL_SIZE) < 0) {
 179                                 pr_err("Unable to allocate bioset for PI\n");
 180                                 ret = -ENOMEM;
 181                                 goto out_blkdev_put;
 182                         }
 183                         pr_debug("IBLOCK setup BIP bs->bio_integrity_pool: %p\n",
 184                                  bs->bio_integrity_pool);
 185                 }
 186                 dev->dev_attrib.hw_pi_prot_type = dev->dev_attrib.pi_prot_type;
 187         }
 188
 189         return 0;
 190
 191 out_blkdev_put:
 192         blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
 193 out_free_bioset:
 194         bioset_free(ib_dev->ibd_bio_set);
 195         ib_dev->ibd_bio_set = NULL;
 196 out:
 197         return ret;
 198 }
 199
 200 static void iblock_free_device(struct se_device *dev)
 201 {
 202         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 203
 204         if (ib_dev->ibd_bd != NULL)
 205                 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
 206         if (ib_dev->ibd_bio_set != NULL)
 207                 bioset_free(ib_dev->ibd_bio_set);
 208
 209         kfree(ib_dev);
 210 }
 211
 212 static unsigned long long iblock_emulate_read_cap_with_block_size(
 213         struct se_device *dev,
 214         struct block_device *bd,
 215         struct request_queue *q)
 216 {
 217         unsigned long long blocks_long = (div_u64(i_size_read(bd->bd_inode),
 218                                         bdev_logical_block_size(bd)) - 1);
 219         u32 block_size = bdev_logical_block_size(bd);
 220
 221         if (block_size == dev->dev_attrib.block_size)
 222                 return blocks_long;
 223
 224         switch (block_size) {
 225         case 4096:
 226                 switch (dev->dev_attrib.block_size) {
 227                 case 2048:
 228                         blocks_long <<= 1;
 229                         break;
 230                 case 1024:
 231                         blocks_long <<= 2;
 232                         break;
 233                 case 512:
 234                         blocks_long <<= 3;
 235                 default:
 236                         break;
 237                 }
 238                 break;
 239         case 2048:
 240                 switch (dev->dev_attrib.block_size) {
 241                 case 4096:
 242                         blocks_long >>= 1;
 243                         break;
 244                 case 1024:
 245                         blocks_long <<= 1;
 246                         break;
 247                 case 512:
 248                         blocks_long <<= 2;
 249                         break;
 250                 default:
 251                         break;
 252                 }
 253                 break;
 254         case 1024:
 255                 switch (dev->dev_attrib.block_size) {
 256                 case 4096:
 257                         blocks_long >>= 2;
 258                         break;
 259                 case 2048:
 260                         blocks_long >>= 1;
 261                         break;
 262                 case 512:
 263                         blocks_long <<= 1;
 264                         break;
 265                 default:
 266                         break;
 267                 }
 268                 break;
 269         case 512:
 270                 switch (dev->dev_attrib.block_size) {
 271                 case 4096:
 272                         blocks_long >>= 3;
 273                         break;
 274                 case 2048:
 275                         blocks_long >>= 2;
 276                         break;
 277                 case 1024:
 278                         blocks_long >>= 1;
 279                         break;
 280                 default:
 281                         break;
 282                 }
 283                 break;
 284         default:
 285                 break;
 286         }
 287
 288         return blocks_long;
 289 }
 290
 291 static void iblock_complete_cmd(struct se_cmd *cmd)
 292 {
 293         struct iblock_req *ibr = cmd->priv;
 294         u8 status;
 295
 296         if (!atomic_dec_and_test(&ibr->pending))
 297                 return;
 298
 299         if (atomic_read(&ibr->ib_bio_err_cnt))
 300                 status = SAM_STAT_CHECK_CONDITION;
 301         else
 302                 status = SAM_STAT_GOOD;
 303
 304         target_complete_cmd(cmd, status);
 305         kfree(ibr);
 306 }
 307
 308 static void iblock_bio_done(struct bio *bio, int err)
 309 {
 310         struct se_cmd *cmd = bio->bi_private;
 311         struct iblock_req *ibr = cmd->priv;
 312
 313         /*
 314          * Set -EIO if !BIO_UPTODATE and the passed is still err=0
 315          */
 316         if (!test_bit(BIO_UPTODATE, &bio->bi_flags) && !err)
 317                 err = -EIO;
 318
 319         if (err != 0) {
 320                 pr_err("test_bit(BIO_UPTODATE) failed for bio: %p,"
 321                         " err: %d\n", bio, err);
 322                 /*
 323                  * Bump the ib_bio_err_cnt and release bio.
 324                  */
 325                 atomic_inc(&ibr->ib_bio_err_cnt);
 326                 smp_mb__after_atomic();
 327         }
 328
 329         bio_put(bio);
 330
 331         iblock_complete_cmd(cmd);
 332 }
 333
 334 static struct bio *
 335 iblock_get_bio(struct se_cmd *cmd, sector_t lba, u32 sg_num)
 336 {
 337         struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
 338         struct bio *bio;
 339
 340         /*
 341          * Only allocate as many vector entries as the bio code allows us to,
 342          * we'll loop later on until we have handled the whole request.
 343          */
 344         if (sg_num > BIO_MAX_PAGES)
 345                 sg_num = BIO_MAX_PAGES;
 346
 347         bio = bio_alloc_bioset(GFP_NOIO, sg_num, ib_dev->ibd_bio_set);
 348         if (!bio) {
 349                 pr_err("Unable to allocate memory for bio\n");
 350                 return NULL;
 351         }
 352
 353         bio->bi_bdev = ib_dev->ibd_bd;
 354         bio->bi_private = cmd;
 355         bio->bi_end_io = &iblock_bio_done;
 356         bio->bi_iter.bi_sector = lba;
 357
 358         return bio;
 359 }
 360
 361 static void iblock_submit_bios(struct bio_list *list, int rw)
 362 {
 363         struct blk_plug plug;
 364         struct bio *bio;
 365
 366         blk_start_plug(&plug);
 367         while ((bio = bio_list_pop(list)))
 368                 submit_bio(rw, bio);
 369         blk_finish_plug(&plug);
 370 }
 371
 372 static void iblock_end_io_flush(struct bio *bio, int err)
 373 {
 374         struct se_cmd *cmd = bio->bi_private;
 375
 376         if (err)
 377                 pr_err("IBLOCK: cache flush failed: %d\n", err);
 378
 379         if (cmd) {
 380                 if (err)
 381                         target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
 382                 else
 383                         target_complete_cmd(cmd, SAM_STAT_GOOD);
 384         }
 385
 386         bio_put(bio);
 387 }
 388
 389 /*
 390  * Implement SYCHRONIZE CACHE.  Note that we can't handle lba ranges and must
 391  * always flush the whole cache.
 392  */
 393 static sense_reason_t
 394 iblock_execute_sync_cache(struct se_cmd *cmd)
 395 {
 396         struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
 397         int immed = (cmd->t_task_cdb[1] & 0x2);
 398         struct bio *bio;
 399
 400         /*
 401          * If the Immediate bit is set, queue up the GOOD response
 402          * for this SYNCHRONIZE_CACHE op.
 403          */
 404         if (immed)
 405                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 406
 407         bio = bio_alloc(GFP_KERNEL, 0);
 408         bio->bi_end_io = iblock_end_io_flush;
 409         bio->bi_bdev = ib_dev->ibd_bd;
 410         if (!immed)
 411                 bio->bi_private = cmd;
 412         submit_bio(WRITE_FLUSH, bio);
 413         return 0;
 414 }
 415
 416 static sense_reason_t
 417 iblock_do_unmap(struct se_cmd *cmd, void *priv,
 418                 sector_t lba, sector_t nolb)
 419 {
 420         struct block_device *bdev = priv;
 421         int ret;
 422
 423         ret = blkdev_issue_discard(bdev, lba, nolb, GFP_KERNEL, 0);
 424         if (ret < 0) {
 425                 pr_err("blkdev_issue_discard() failed: %d\n", ret);
 426                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 427         }
 428
 429         return 0;
 430 }
 431
 432 static sense_reason_t
 433 iblock_execute_unmap(struct se_cmd *cmd)
 434 {
 435         struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
 436
 437         return sbc_execute_unmap(cmd, iblock_do_unmap, bdev);
 438 }
 439
 440 static sense_reason_t
 441 iblock_execute_write_same_unmap(struct se_cmd *cmd)
 442 {
 443         struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
 444         sector_t lba = cmd->t_task_lba;
 445         sector_t nolb = sbc_get_write_same_sectors(cmd);
 446         int ret;
 447
 448         ret = iblock_do_unmap(cmd, bdev, lba, nolb);
 449         if (ret)
 450                 return ret;
 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 iblock_req *ibr;
 460         struct scatterlist *sg;
 461         struct bio *bio;
 462         struct bio_list list;
 463         sector_t block_lba = cmd->t_task_lba;
 464         sector_t sectors = sbc_get_write_same_sectors(cmd);
 465
 466         sg = &cmd->t_data_sg[0];
 467
 468         if (cmd->t_data_nents > 1 ||
 469             sg->length != cmd->se_dev->dev_attrib.block_size) {
 470                 pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
 471                         " block_size: %u\n", cmd->t_data_nents, sg->length,
 472                         cmd->se_dev->dev_attrib.block_size);
 473                 return TCM_INVALID_CDB_FIELD;
 474         }
 475
 476         ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
 477         if (!ibr)
 478                 goto fail;
 479         cmd->priv = ibr;
 480
 481         bio = iblock_get_bio(cmd, block_lba, 1);
 482         if (!bio)
 483                 goto fail_free_ibr;
 484
 485         bio_list_init(&list);
 486         bio_list_add(&list, bio);
 487
 488         atomic_set(&ibr->pending, 1);
 489
 490         while (sectors) {
 491                 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
 492                                 != sg->length) {
 493
 494                         bio = iblock_get_bio(cmd, block_lba, 1);
 495                         if (!bio)
 496                                 goto fail_put_bios;
 497
 498                         atomic_inc(&ibr->pending);
 499                         bio_list_add(&list, bio);
 500                 }
 501
 502                 /* Always in 512 byte units for Linux/Block */
 503                 block_lba += sg->length >> IBLOCK_LBA_SHIFT;
 504                 sectors -= 1;
 505         }
 506
 507         iblock_submit_bios(&list, WRITE);
 508         return 0;
 509
 510 fail_put_bios:
 511         while ((bio = bio_list_pop(&list)))
 512                 bio_put(bio);
 513 fail_free_ibr:
 514         kfree(ibr);
 515 fail:
 516         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 517 }
 518
 519 enum {
 520         Opt_udev_path, Opt_readonly, Opt_force, Opt_err
 521 };
 522
 523 static match_table_t tokens = {
 524         {Opt_udev_path, "udev_path=%s"},
 525         {Opt_readonly, "readonly=%d"},
 526         {Opt_force, "force=%d"},
 527         {Opt_err, NULL}
 528 };
 529
 530 static ssize_t iblock_set_configfs_dev_params(struct se_device *dev,
 531                 const char *page, ssize_t count)
 532 {
 533         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 534         char *orig, *ptr, *arg_p, *opts;
 535         substring_t args[MAX_OPT_ARGS];
 536         int ret = 0, token;
 537         unsigned long tmp_readonly;
 538
 539         opts = kstrdup(page, GFP_KERNEL);
 540         if (!opts)
 541                 return -ENOMEM;
 542
 543         orig = opts;
 544
 545         while ((ptr = strsep(&opts, ",\n")) != NULL) {
 546                 if (!*ptr)
 547                         continue;
 548
 549                 token = match_token(ptr, tokens, args);
 550                 switch (token) {
 551                 case Opt_udev_path:
 552                         if (ib_dev->ibd_bd) {
 553                                 pr_err("Unable to set udev_path= while"
 554                                         " ib_dev->ibd_bd exists\n");
 555                                 ret = -EEXIST;
 556                                 goto out;
 557                         }
 558                         if (match_strlcpy(ib_dev->ibd_udev_path, &args[0],
 559                                 SE_UDEV_PATH_LEN) == 0) {
 560                                 ret = -EINVAL;
 561                                 break;
 562                         }
 563                         pr_debug("IBLOCK: Referencing UDEV path: %s\n",
 564                                         ib_dev->ibd_udev_path);
 565                         ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH;
 566                         break;
 567                 case Opt_readonly:
 568                         arg_p = match_strdup(&args[0]);
 569                         if (!arg_p) {
 570                                 ret = -ENOMEM;
 571                                 break;
 572                         }
 573                         ret = kstrtoul(arg_p, 0, &tmp_readonly);
 574                         kfree(arg_p);
 575                         if (ret < 0) {
 576                                 pr_err("kstrtoul() failed for"
 577                                                 " readonly=\n");
 578                                 goto out;
 579                         }
 580                         ib_dev->ibd_readonly = tmp_readonly;
 581                         pr_debug("IBLOCK: readonly: %d\n", ib_dev->ibd_readonly);
 582                         break;
 583                 case Opt_force:
 584                         break;
 585                 default:
 586                         break;
 587                 }
 588         }
 589
 590 out:
 591         kfree(orig);
 592         return (!ret) ? count : ret;
 593 }
 594
 595 static ssize_t iblock_show_configfs_dev_params(struct se_device *dev, char *b)
 596 {
 597         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 598         struct block_device *bd = ib_dev->ibd_bd;
 599         char buf[BDEVNAME_SIZE];
 600         ssize_t bl = 0;
 601
 602         if (bd)
 603                 bl += sprintf(b + bl, "iBlock device: %s",
 604                                 bdevname(bd, buf));
 605         if (ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)
 606                 bl += sprintf(b + bl, "  UDEV PATH: %s",
 607                                 ib_dev->ibd_udev_path);
 608         bl += sprintf(b + bl, "  readonly: %d\n", ib_dev->ibd_readonly);
 609
 610         bl += sprintf(b + bl, "        ");
 611         if (bd) {
 612                 bl += sprintf(b + bl, "Major: %d Minor: %d  %s\n",
 613                         MAJOR(bd->bd_dev), MINOR(bd->bd_dev), (!bd->bd_contains) ?
 614                         "" : (bd->bd_holder == ib_dev) ?
 615                         "CLAIMED: IBLOCK" : "CLAIMED: OS");
 616         } else {
 617                 bl += sprintf(b + bl, "Major: 0 Minor: 0\n");
 618         }
 619
 620         return bl;
 621 }
 622
 623 static int
 624 iblock_alloc_bip(struct se_cmd *cmd, struct bio *bio)
 625 {
 626         struct se_device *dev = cmd->se_dev;
 627         struct blk_integrity *bi;
 628         struct bio_integrity_payload *bip;
 629         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 630         struct scatterlist *sg;
 631         int i, rc;
 632
 633         bi = bdev_get_integrity(ib_dev->ibd_bd);
 634         if (!bi) {
 635                 pr_err("Unable to locate bio_integrity\n");
 636                 return -ENODEV;
 637         }
 638
 639         bip = bio_integrity_alloc(bio, GFP_NOIO, cmd->t_prot_nents);
 640         if (!bip) {
 641                 pr_err("Unable to allocate bio_integrity_payload\n");
 642                 return -ENOMEM;
 643         }
 644
 645         bip->bip_iter.bi_size = (cmd->data_length / dev->dev_attrib.block_size) *
 646                          dev->prot_length;
 647         bip->bip_iter.bi_sector = bio->bi_iter.bi_sector;
 648
 649         pr_debug("IBLOCK BIP Size: %u Sector: %llu\n", bip->bip_iter.bi_size,
 650                  (unsigned long long)bip->bip_iter.bi_sector);
 651
 652         for_each_sg(cmd->t_prot_sg, sg, cmd->t_prot_nents, i) {
 653
 654                 rc = bio_integrity_add_page(bio, sg_page(sg), sg->length,
 655                                             sg->offset);
 656                 if (rc != sg->length) {
 657                         pr_err("bio_integrity_add_page() failed; %d\n", rc);
 658                         return -ENOMEM;
 659                 }
 660
 661                 pr_debug("Added bio integrity page: %p length: %d offset; %d\n",
 662                          sg_page(sg), sg->length, sg->offset);
 663         }
 664
 665         return 0;
 666 }
 667
 668 static sense_reason_t
 669 iblock_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 670                   enum dma_data_direction data_direction)
 671 {
 672         struct se_device *dev = cmd->se_dev;
 673         struct iblock_req *ibr;
 674         struct bio *bio, *bio_start;
 675         struct bio_list list;
 676         struct scatterlist *sg;
 677         u32 sg_num = sgl_nents;
 678         sector_t block_lba;
 679         unsigned bio_cnt;
 680         int rw = 0;
 681         int i;
 682
 683         if (data_direction == DMA_TO_DEVICE) {
 684                 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 685                 struct request_queue *q = bdev_get_queue(ib_dev->ibd_bd);
 686                 /*
 687                  * Force writethrough using WRITE_FUA if a volatile write cache
 688                  * is not enabled, or if initiator set the Force Unit Access bit.
 689                  */
 690                 if (q->flush_flags & REQ_FUA) {
 691                         if (cmd->se_cmd_flags & SCF_FUA)
 692                                 rw = WRITE_FUA;
 693                         else if (!(q->flush_flags & REQ_FLUSH))
 694                                 rw = WRITE_FUA;
 695                         else
 696                                 rw = WRITE;
 697                 } else {
 698                         rw = WRITE;
 699                 }
 700         } else {
 701                 rw = READ;
 702         }
 703
 704         /*
 705          * Convert the blocksize advertised to the initiator to the 512 byte
 706          * units unconditionally used by the Linux block layer.
 707          */
 708         if (dev->dev_attrib.block_size == 4096)
 709                 block_lba = (cmd->t_task_lba << 3);
 710         else if (dev->dev_attrib.block_size == 2048)
 711                 block_lba = (cmd->t_task_lba << 2);
 712         else if (dev->dev_attrib.block_size == 1024)
 713                 block_lba = (cmd->t_task_lba << 1);
 714         else if (dev->dev_attrib.block_size == 512)
 715                 block_lba = cmd->t_task_lba;
 716         else {
 717                 pr_err("Unsupported SCSI -> BLOCK LBA conversion:"
 718                                 " %u\n", dev->dev_attrib.block_size);
 719                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 720         }
 721
 722         ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
 723         if (!ibr)
 724                 goto fail;
 725         cmd->priv = ibr;
 726
 727         if (!sgl_nents) {
 728                 atomic_set(&ibr->pending, 1);
 729                 iblock_complete_cmd(cmd);
 730                 return 0;
 731         }
 732
 733         bio = iblock_get_bio(cmd, block_lba, sgl_nents);
 734         if (!bio)
 735                 goto fail_free_ibr;
 736
 737         bio_start = bio;
 738         bio_list_init(&list);
 739         bio_list_add(&list, bio);
 740
 741         atomic_set(&ibr->pending, 2);
 742         bio_cnt = 1;
 743
 744         for_each_sg(sgl, sg, sgl_nents, i) {
 745                 /*
 746                  * XXX: if the length the device accepts is shorter than the
 747                  *      length of the S/G list entry this will cause and
 748                  *      endless loop.  Better hope no driver uses huge pages.
 749                  */
 750                 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
 751                                 != sg->length) {
 752                         if (bio_cnt >= IBLOCK_MAX_BIO_PER_TASK) {
 753                                 iblock_submit_bios(&list, rw);
 754                                 bio_cnt = 0;
 755                         }
 756
 757                         bio = iblock_get_bio(cmd, block_lba, sg_num);
 758                         if (!bio)
 759                                 goto fail_put_bios;
 760
 761                         atomic_inc(&ibr->pending);
 762                         bio_list_add(&list, bio);
 763                         bio_cnt++;
 764                 }
 765
 766                 /* Always in 512 byte units for Linux/Block */
 767                 block_lba += sg->length >> IBLOCK_LBA_SHIFT;
 768                 sg_num--;
 769         }
 770
 771         if (cmd->prot_type) {
 772                 int rc = iblock_alloc_bip(cmd, bio_start);
 773                 if (rc)
 774                         goto fail_put_bios;
 775         }
 776
 777         iblock_submit_bios(&list, rw);
 778         iblock_complete_cmd(cmd);
 779         return 0;
 780
 781 fail_put_bios:
 782         while ((bio = bio_list_pop(&list)))
 783                 bio_put(bio);
 784 fail_free_ibr:
 785         kfree(ibr);
 786 fail:
 787         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 788 }
 789
 790 static sector_t iblock_get_blocks(struct se_device *dev)
 791 {
 792         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 793         struct block_device *bd = ib_dev->ibd_bd;
 794         struct request_queue *q = bdev_get_queue(bd);
 795
 796         return iblock_emulate_read_cap_with_block_size(dev, bd, q);
 797 }
 798
 799 static sector_t iblock_get_alignment_offset_lbas(struct se_device *dev)
 800 {
 801         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 802         struct block_device *bd = ib_dev->ibd_bd;
 803         int ret;
 804
 805         ret = bdev_alignment_offset(bd);
 806         if (ret == -1)
 807                 return 0;
 808
 809         /* convert offset-bytes to offset-lbas */
 810         return ret / bdev_logical_block_size(bd);
 811 }
 812
 813 static unsigned int iblock_get_lbppbe(struct se_device *dev)
 814 {
 815         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 816         struct block_device *bd = ib_dev->ibd_bd;
 817         int logs_per_phys = bdev_physical_block_size(bd) / bdev_logical_block_size(bd);
 818
 819         return ilog2(logs_per_phys);
 820 }
 821
 822 static unsigned int iblock_get_io_min(struct se_device *dev)
 823 {
 824         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 825         struct block_device *bd = ib_dev->ibd_bd;
 826
 827         return bdev_io_min(bd);
 828 }
 829
 830 static unsigned int iblock_get_io_opt(struct se_device *dev)
 831 {
 832         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 833         struct block_device *bd = ib_dev->ibd_bd;
 834
 835         return bdev_io_opt(bd);
 836 }
 837
 838 static struct sbc_ops iblock_sbc_ops = {
 839         .execute_rw             = iblock_execute_rw,
 840         .execute_sync_cache     = iblock_execute_sync_cache,
 841         .execute_write_same     = iblock_execute_write_same,
 842         .execute_write_same_unmap = iblock_execute_write_same_unmap,
 843         .execute_unmap          = iblock_execute_unmap,
 844 };
 845
 846 static sense_reason_t
 847 iblock_parse_cdb(struct se_cmd *cmd)
 848 {
 849         return sbc_parse_cdb(cmd, &iblock_sbc_ops);
 850 }
 851
 852 static bool iblock_get_write_cache(struct se_device *dev)
 853 {
 854         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 855         struct block_device *bd = ib_dev->ibd_bd;
 856         struct request_queue *q = bdev_get_queue(bd);
 857
 858         return q->flush_flags & REQ_FLUSH;
 859 }
 860
 861 static struct se_subsystem_api iblock_template = {
 862         .name                   = "iblock",
 863         .inquiry_prod           = "IBLOCK",
 864         .inquiry_rev            = IBLOCK_VERSION,
 865         .owner                  = THIS_MODULE,
 866         .transport_type         = TRANSPORT_PLUGIN_VHBA_PDEV,
 867         .attach_hba             = iblock_attach_hba,
 868         .detach_hba             = iblock_detach_hba,
 869         .alloc_device           = iblock_alloc_device,
 870         .configure_device       = iblock_configure_device,
 871         .free_device            = iblock_free_device,
 872         .parse_cdb              = iblock_parse_cdb,
 873         .set_configfs_dev_params = iblock_set_configfs_dev_params,
 874         .show_configfs_dev_params = iblock_show_configfs_dev_params,
 875         .get_device_type        = sbc_get_device_type,
 876         .get_blocks             = iblock_get_blocks,
 877         .get_alignment_offset_lbas = iblock_get_alignment_offset_lbas,
 878         .get_lbppbe             = iblock_get_lbppbe,
 879         .get_io_min             = iblock_get_io_min,
 880         .get_io_opt             = iblock_get_io_opt,
 881         .get_write_cache        = iblock_get_write_cache,
 882 };
 883
 884 static int __init iblock_module_init(void)
 885 {
 886         return transport_subsystem_register(&iblock_template);
 887 }
 888
 889 static void __exit iblock_module_exit(void)
 890 {
 891         transport_subsystem_release(&iblock_template);
 892 }
 893
 894 MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin");
 895 MODULE_AUTHOR("nab@Linux-iSCSI.org");
 896 MODULE_LICENSE("GPL");
 897
 898 module_init(iblock_module_init);
 899 module_exit(iblock_module_exit);