drivers/target/target_core_iblock.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*******************************************************************************
   3  * Filename:  target_core_iblock.c
   4  *
   5  * This file contains the Storage Engine  <-> Linux BlockIO transport
   6  * specific functions.
   7  *
   8  * (c) Copyright 2003-2013 Datera, Inc.
   9  *
  10  * Nicholas A. Bellinger <nab@kernel.org>
  11  *
  12  ******************************************************************************/
  13
  14 #include <linux/string.h>
  15 #include <linux/parser.h>
  16 #include <linux/timer.h>
  17 #include <linux/fs.h>
  18 #include <linux/blkdev.h>
  19 #include <linux/blk-integrity.h>
  20 #include <linux/slab.h>
  21 #include <linux/spinlock.h>
  22 #include <linux/bio.h>
  23 #include <linux/file.h>
  24 #include <linux/module.h>
  25 #include <linux/scatterlist.h>
  26 #include <scsi/scsi_proto.h>
  27 #include <asm/unaligned.h>
  28
  29 #include <target/target_core_base.h>
  30 #include <target/target_core_backend.h>
  31
  32 #include "target_core_iblock.h"
  33
  34 #define IBLOCK_MAX_BIO_PER_TASK  32     /* max # of bios to submit at a time */
  35 #define IBLOCK_BIO_POOL_SIZE    128
  36
  37 static inline struct iblock_dev *IBLOCK_DEV(struct se_device *dev)
  38 {
  39         return container_of(dev, struct iblock_dev, dev);
  40 }
  41
  42
  43 static int iblock_attach_hba(struct se_hba *hba, u32 host_id)
  44 {
  45         pr_debug("CORE_HBA[%d] - TCM iBlock HBA Driver %s on"
  46                 " Generic Target Core Stack %s\n", hba->hba_id,
  47                 IBLOCK_VERSION, TARGET_CORE_VERSION);
  48         return 0;
  49 }
  50
  51 static void iblock_detach_hba(struct se_hba *hba)
  52 {
  53 }
  54
  55 static struct se_device *iblock_alloc_device(struct se_hba *hba, const char *name)
  56 {
  57         struct iblock_dev *ib_dev = NULL;
  58
  59         ib_dev = kzalloc(sizeof(struct iblock_dev), GFP_KERNEL);
  60         if (!ib_dev) {
  61                 pr_err("Unable to allocate struct iblock_dev\n");
  62                 return NULL;
  63         }
  64
  65         ib_dev->ibd_plug = kcalloc(nr_cpu_ids, sizeof(*ib_dev->ibd_plug),
  66                                    GFP_KERNEL);
  67         if (!ib_dev->ibd_plug)
  68                 goto free_dev;
  69
  70         pr_debug( "IBLOCK: Allocated ib_dev for %s\n", name);
  71
  72         return &ib_dev->dev;
  73
  74 free_dev:
  75         kfree(ib_dev);
  76         return NULL;
  77 }
  78
  79 static bool iblock_configure_unmap(struct se_device *dev)
  80 {
  81         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
  82
  83         return target_configure_unmap_from_queue(&dev->dev_attrib,
  84                                                  ib_dev->ibd_bd);
  85 }
  86
  87 static int iblock_configure_device(struct se_device *dev)
  88 {
  89         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
  90         struct request_queue *q;
  91         struct block_device *bd = NULL;
  92         struct blk_integrity *bi;
  93         fmode_t mode;
  94         unsigned int max_write_zeroes_sectors;
  95         int ret;
  96
  97         if (!(ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)) {
  98                 pr_err("Missing udev_path= parameters for IBLOCK\n");
  99                 return -EINVAL;
 100         }
 101
 102         ret = bioset_init(&ib_dev->ibd_bio_set, IBLOCK_BIO_POOL_SIZE, 0, BIOSET_NEED_BVECS);
 103         if (ret) {
 104                 pr_err("IBLOCK: Unable to create bioset\n");
 105                 goto out;
 106         }
 107
 108         pr_debug( "IBLOCK: Claiming struct block_device: %s\n",
 109                         ib_dev->ibd_udev_path);
 110
 111         mode = FMODE_READ|FMODE_EXCL;
 112         if (!ib_dev->ibd_readonly)
 113                 mode |= FMODE_WRITE;
 114         else
 115                 dev->dev_flags |= DF_READ_ONLY;
 116
 117         bd = blkdev_get_by_path(ib_dev->ibd_udev_path, mode, ib_dev);
 118         if (IS_ERR(bd)) {
 119                 ret = PTR_ERR(bd);
 120                 goto out_free_bioset;
 121         }
 122         ib_dev->ibd_bd = bd;
 123
 124         q = bdev_get_queue(bd);
 125
 126         dev->dev_attrib.hw_block_size = bdev_logical_block_size(bd);
 127         dev->dev_attrib.hw_max_sectors = queue_max_hw_sectors(q);
 128         dev->dev_attrib.hw_queue_depth = q->nr_requests;
 129
 130         /*
 131          * Enable write same emulation for IBLOCK and use 0xFFFF as
 132          * the smaller WRITE_SAME(10) only has a two-byte block count.
 133          */
 134         max_write_zeroes_sectors = bdev_write_zeroes_sectors(bd);
 135         if (max_write_zeroes_sectors)
 136                 dev->dev_attrib.max_write_same_len = max_write_zeroes_sectors;
 137         else
 138                 dev->dev_attrib.max_write_same_len = 0xFFFF;
 139
 140         if (bdev_nonrot(bd))
 141                 dev->dev_attrib.is_nonrot = 1;
 142
 143         bi = bdev_get_integrity(bd);
 144         if (bi) {
 145                 struct bio_set *bs = &ib_dev->ibd_bio_set;
 146
 147                 if (!strcmp(bi->profile->name, "T10-DIF-TYPE3-IP") ||
 148                     !strcmp(bi->profile->name, "T10-DIF-TYPE1-IP")) {
 149                         pr_err("IBLOCK export of blk_integrity: %s not"
 150                                " supported\n", bi->profile->name);
 151                         ret = -ENOSYS;
 152                         goto out_blkdev_put;
 153                 }
 154
 155                 if (!strcmp(bi->profile->name, "T10-DIF-TYPE3-CRC")) {
 156                         dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE3_PROT;
 157                 } else if (!strcmp(bi->profile->name, "T10-DIF-TYPE1-CRC")) {
 158                         dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE1_PROT;
 159                 }
 160
 161                 if (dev->dev_attrib.pi_prot_type) {
 162                         if (bioset_integrity_create(bs, IBLOCK_BIO_POOL_SIZE) < 0) {
 163                                 pr_err("Unable to allocate bioset for PI\n");
 164                                 ret = -ENOMEM;
 165                                 goto out_blkdev_put;
 166                         }
 167                         pr_debug("IBLOCK setup BIP bs->bio_integrity_pool: %p\n",
 168                                  &bs->bio_integrity_pool);
 169                 }
 170                 dev->dev_attrib.hw_pi_prot_type = dev->dev_attrib.pi_prot_type;
 171         }
 172
 173         return 0;
 174
 175 out_blkdev_put:
 176         blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
 177 out_free_bioset:
 178         bioset_exit(&ib_dev->ibd_bio_set);
 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->ibd_plug);
 189         kfree(ib_dev);
 190 }
 191
 192 static void iblock_free_device(struct se_device *dev)
 193 {
 194         call_rcu(&dev->rcu_head, iblock_dev_call_rcu);
 195 }
 196
 197 static void iblock_destroy_device(struct se_device *dev)
 198 {
 199         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 200
 201         if (ib_dev->ibd_bd != NULL)
 202                 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
 203         bioset_exit(&ib_dev->ibd_bio_set);
 204 }
 205
 206 static struct se_dev_plug *iblock_plug_device(struct se_device *se_dev)
 207 {
 208         struct iblock_dev *ib_dev = IBLOCK_DEV(se_dev);
 209         struct iblock_dev_plug *ib_dev_plug;
 210
 211         /*
 212          * Each se_device has a per cpu work this can be run from. We
 213          * shouldn't have multiple threads on the same cpu calling this
 214          * at the same time.
 215          */
 216         ib_dev_plug = &ib_dev->ibd_plug[raw_smp_processor_id()];
 217         if (test_and_set_bit(IBD_PLUGF_PLUGGED, &ib_dev_plug->flags))
 218                 return NULL;
 219
 220         blk_start_plug(&ib_dev_plug->blk_plug);
 221         return &ib_dev_plug->se_plug;
 222 }
 223
 224 static void iblock_unplug_device(struct se_dev_plug *se_plug)
 225 {
 226         struct iblock_dev_plug *ib_dev_plug = container_of(se_plug,
 227                                         struct iblock_dev_plug, se_plug);
 228
 229         blk_finish_plug(&ib_dev_plug->blk_plug);
 230         clear_bit(IBD_PLUGF_PLUGGED, &ib_dev_plug->flags);
 231 }
 232
 233 static sector_t iblock_get_blocks(struct se_device *dev)
 234 {
 235         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 236         u32 block_size = bdev_logical_block_size(ib_dev->ibd_bd);
 237         unsigned long long blocks_long =
 238                 div_u64(bdev_nr_bytes(ib_dev->ibd_bd), block_size) - 1;
 239
 240         if (block_size == dev->dev_attrib.block_size)
 241                 return blocks_long;
 242
 243         switch (block_size) {
 244         case 4096:
 245                 switch (dev->dev_attrib.block_size) {
 246                 case 2048:
 247                         blocks_long <<= 1;
 248                         break;
 249                 case 1024:
 250                         blocks_long <<= 2;
 251                         break;
 252                 case 512:
 253                         blocks_long <<= 3;
 254                         break;
 255                 default:
 256                         break;
 257                 }
 258                 break;
 259         case 2048:
 260                 switch (dev->dev_attrib.block_size) {
 261                 case 4096:
 262                         blocks_long >>= 1;
 263                         break;
 264                 case 1024:
 265                         blocks_long <<= 1;
 266                         break;
 267                 case 512:
 268                         blocks_long <<= 2;
 269                         break;
 270                 default:
 271                         break;
 272                 }
 273                 break;
 274         case 1024:
 275                 switch (dev->dev_attrib.block_size) {
 276                 case 4096:
 277                         blocks_long >>= 2;
 278                         break;
 279                 case 2048:
 280                         blocks_long >>= 1;
 281                         break;
 282                 case 512:
 283                         blocks_long <<= 1;
 284                         break;
 285                 default:
 286                         break;
 287                 }
 288                 break;
 289         case 512:
 290                 switch (dev->dev_attrib.block_size) {
 291                 case 4096:
 292                         blocks_long >>= 3;
 293                         break;
 294                 case 2048:
 295                         blocks_long >>= 2;
 296                         break;
 297                 case 1024:
 298                         blocks_long >>= 1;
 299                         break;
 300                 default:
 301                         break;
 302                 }
 303                 break;
 304         default:
 305                 break;
 306         }
 307
 308         return blocks_long;
 309 }
 310
 311 static void iblock_complete_cmd(struct se_cmd *cmd)
 312 {
 313         struct iblock_req *ibr = cmd->priv;
 314         u8 status;
 315
 316         if (!refcount_dec_and_test(&ibr->pending))
 317                 return;
 318
 319         if (atomic_read(&ibr->ib_bio_err_cnt))
 320                 status = SAM_STAT_CHECK_CONDITION;
 321         else
 322                 status = SAM_STAT_GOOD;
 323
 324         target_complete_cmd(cmd, status);
 325         kfree(ibr);
 326 }
 327
 328 static void iblock_bio_done(struct bio *bio)
 329 {
 330         struct se_cmd *cmd = bio->bi_private;
 331         struct iblock_req *ibr = cmd->priv;
 332
 333         if (bio->bi_status) {
 334                 pr_err("bio error: %p,  err: %d\n", bio, bio->bi_status);
 335                 /*
 336                  * Bump the ib_bio_err_cnt and release bio.
 337                  */
 338                 atomic_inc(&ibr->ib_bio_err_cnt);
 339                 smp_mb__after_atomic();
 340         }
 341
 342         bio_put(bio);
 343
 344         iblock_complete_cmd(cmd);
 345 }
 346
 347 static struct bio *iblock_get_bio(struct se_cmd *cmd, sector_t lba, u32 sg_num,
 348                                   blk_opf_t opf)
 349 {
 350         struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
 351         struct bio *bio;
 352
 353         /*
 354          * Only allocate as many vector entries as the bio code allows us to,
 355          * we'll loop later on until we have handled the whole request.
 356          */
 357         bio = bio_alloc_bioset(ib_dev->ibd_bd, bio_max_segs(sg_num), opf,
 358                                GFP_NOIO, &ib_dev->ibd_bio_set);
 359         if (!bio) {
 360                 pr_err("Unable to allocate memory for bio\n");
 361                 return NULL;
 362         }
 363
 364         bio->bi_private = cmd;
 365         bio->bi_end_io = &iblock_bio_done;
 366         bio->bi_iter.bi_sector = lba;
 367
 368         return bio;
 369 }
 370
 371 static void iblock_submit_bios(struct bio_list *list)
 372 {
 373         struct blk_plug plug;
 374         struct bio *bio;
 375         /*
 376          * The block layer handles nested plugs, so just plug/unplug to handle
 377          * fabric drivers that didn't support batching and multi bio cmds.
 378          */
 379         blk_start_plug(&plug);
 380         while ((bio = bio_list_pop(list)))
 381                 submit_bio(bio);
 382         blk_finish_plug(&plug);
 383 }
 384
 385 static void iblock_end_io_flush(struct bio *bio)
 386 {
 387         struct se_cmd *cmd = bio->bi_private;
 388
 389         if (bio->bi_status)
 390                 pr_err("IBLOCK: cache flush failed: %d\n", bio->bi_status);
 391
 392         if (cmd) {
 393                 if (bio->bi_status)
 394                         target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
 395                 else
 396                         target_complete_cmd(cmd, SAM_STAT_GOOD);
 397         }
 398
 399         bio_put(bio);
 400 }
 401
 402 /*
 403  * Implement SYCHRONIZE CACHE.  Note that we can't handle lba ranges and must
 404  * always flush the whole cache.
 405  */
 406 static sense_reason_t
 407 iblock_execute_sync_cache(struct se_cmd *cmd)
 408 {
 409         struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
 410         int immed = (cmd->t_task_cdb[1] & 0x2);
 411         struct bio *bio;
 412
 413         /*
 414          * If the Immediate bit is set, queue up the GOOD response
 415          * for this SYNCHRONIZE_CACHE op.
 416          */
 417         if (immed)
 418                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 419
 420         bio = bio_alloc(ib_dev->ibd_bd, 0, REQ_OP_WRITE | REQ_PREFLUSH,
 421                         GFP_KERNEL);
 422         bio->bi_end_io = iblock_end_io_flush;
 423         if (!immed)
 424                 bio->bi_private = cmd;
 425         submit_bio(bio);
 426         return 0;
 427 }
 428
 429 static sense_reason_t
 430 iblock_execute_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
 431 {
 432         struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
 433         struct se_device *dev = cmd->se_dev;
 434         int ret;
 435
 436         ret = blkdev_issue_discard(bdev,
 437                                    target_to_linux_sector(dev, lba),
 438                                    target_to_linux_sector(dev,  nolb),
 439                                    GFP_KERNEL);
 440         if (ret < 0) {
 441                 pr_err("blkdev_issue_discard() failed: %d\n", ret);
 442                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 443         }
 444
 445         return 0;
 446 }
 447
 448 static sense_reason_t
 449 iblock_execute_zero_out(struct block_device *bdev, struct se_cmd *cmd)
 450 {
 451         struct se_device *dev = cmd->se_dev;
 452         struct scatterlist *sg = &cmd->t_data_sg[0];
 453         unsigned char *buf, *not_zero;
 454         int ret;
 455
 456         buf = kmap(sg_page(sg)) + sg->offset;
 457         if (!buf)
 458                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 459         /*
 460          * Fall back to block_execute_write_same() slow-path if
 461          * incoming WRITE_SAME payload does not contain zeros.
 462          */
 463         not_zero = memchr_inv(buf, 0x00, cmd->data_length);
 464         kunmap(sg_page(sg));
 465
 466         if (not_zero)
 467                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 468
 469         ret = blkdev_issue_zeroout(bdev,
 470                                 target_to_linux_sector(dev, cmd->t_task_lba),
 471                                 target_to_linux_sector(dev,
 472                                         sbc_get_write_same_sectors(cmd)),
 473                                 GFP_KERNEL, BLKDEV_ZERO_NOUNMAP);
 474         if (ret)
 475                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 476
 477         target_complete_cmd(cmd, SAM_STAT_GOOD);
 478         return 0;
 479 }
 480
 481 static sense_reason_t
 482 iblock_execute_write_same(struct se_cmd *cmd)
 483 {
 484         struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
 485         struct iblock_req *ibr;
 486         struct scatterlist *sg;
 487         struct bio *bio;
 488         struct bio_list list;
 489         struct se_device *dev = cmd->se_dev;
 490         sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba);
 491         sector_t sectors = target_to_linux_sector(dev,
 492                                         sbc_get_write_same_sectors(cmd));
 493
 494         if (cmd->prot_op) {
 495                 pr_err("WRITE_SAME: Protection information with IBLOCK"
 496                        " backends not supported\n");
 497                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 498         }
 499
 500         if (!cmd->t_data_nents)
 501                 return TCM_INVALID_CDB_FIELD;
 502
 503         sg = &cmd->t_data_sg[0];
 504
 505         if (cmd->t_data_nents > 1 ||
 506             sg->length != cmd->se_dev->dev_attrib.block_size) {
 507                 pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
 508                         " block_size: %u\n", cmd->t_data_nents, sg->length,
 509                         cmd->se_dev->dev_attrib.block_size);
 510                 return TCM_INVALID_CDB_FIELD;
 511         }
 512
 513         if (bdev_write_zeroes_sectors(bdev)) {
 514                 if (!iblock_execute_zero_out(bdev, cmd))
 515                         return 0;
 516         }
 517
 518         ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
 519         if (!ibr)
 520                 goto fail;
 521         cmd->priv = ibr;
 522
 523         bio = iblock_get_bio(cmd, block_lba, 1, REQ_OP_WRITE);
 524         if (!bio)
 525                 goto fail_free_ibr;
 526
 527         bio_list_init(&list);
 528         bio_list_add(&list, bio);
 529
 530         refcount_set(&ibr->pending, 1);
 531
 532         while (sectors) {
 533                 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
 534                                 != sg->length) {
 535
 536                         bio = iblock_get_bio(cmd, block_lba, 1, REQ_OP_WRITE);
 537                         if (!bio)
 538                                 goto fail_put_bios;
 539
 540                         refcount_inc(&ibr->pending);
 541                         bio_list_add(&list, bio);
 542                 }
 543
 544                 /* Always in 512 byte units for Linux/Block */
 545                 block_lba += sg->length >> SECTOR_SHIFT;
 546                 sectors -= sg->length >> SECTOR_SHIFT;
 547         }
 548
 549         iblock_submit_bios(&list);
 550         return 0;
 551
 552 fail_put_bios:
 553         while ((bio = bio_list_pop(&list)))
 554                 bio_put(bio);
 555 fail_free_ibr:
 556         kfree(ibr);
 557 fail:
 558         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 559 }
 560
 561 enum {
 562         Opt_udev_path, Opt_readonly, Opt_force, Opt_err
 563 };
 564
 565 static match_table_t tokens = {
 566         {Opt_udev_path, "udev_path=%s"},
 567         {Opt_readonly, "readonly=%d"},
 568         {Opt_force, "force=%d"},
 569         {Opt_err, NULL}
 570 };
 571
 572 static ssize_t iblock_set_configfs_dev_params(struct se_device *dev,
 573                 const char *page, ssize_t count)
 574 {
 575         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 576         char *orig, *ptr, *arg_p, *opts;
 577         substring_t args[MAX_OPT_ARGS];
 578         int ret = 0, token;
 579         unsigned long tmp_readonly;
 580
 581         opts = kstrdup(page, GFP_KERNEL);
 582         if (!opts)
 583                 return -ENOMEM;
 584
 585         orig = opts;
 586
 587         while ((ptr = strsep(&opts, ",\n")) != NULL) {
 588                 if (!*ptr)
 589                         continue;
 590
 591                 token = match_token(ptr, tokens, args);
 592                 switch (token) {
 593                 case Opt_udev_path:
 594                         if (ib_dev->ibd_bd) {
 595                                 pr_err("Unable to set udev_path= while"
 596                                         " ib_dev->ibd_bd exists\n");
 597                                 ret = -EEXIST;
 598                                 goto out;
 599                         }
 600                         if (match_strlcpy(ib_dev->ibd_udev_path, &args[0],
 601                                 SE_UDEV_PATH_LEN) == 0) {
 602                                 ret = -EINVAL;
 603                                 break;
 604                         }
 605                         pr_debug("IBLOCK: Referencing UDEV path: %s\n",
 606                                         ib_dev->ibd_udev_path);
 607                         ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH;
 608                         break;
 609                 case Opt_readonly:
 610                         arg_p = match_strdup(&args[0]);
 611                         if (!arg_p) {
 612                                 ret = -ENOMEM;
 613                                 break;
 614                         }
 615                         ret = kstrtoul(arg_p, 0, &tmp_readonly);
 616                         kfree(arg_p);
 617                         if (ret < 0) {
 618                                 pr_err("kstrtoul() failed for"
 619                                                 " readonly=\n");
 620                                 goto out;
 621                         }
 622                         ib_dev->ibd_readonly = tmp_readonly;
 623                         pr_debug("IBLOCK: readonly: %d\n", ib_dev->ibd_readonly);
 624                         break;
 625                 case Opt_force:
 626                         break;
 627                 default:
 628                         break;
 629                 }
 630         }
 631
 632 out:
 633         kfree(orig);
 634         return (!ret) ? count : ret;
 635 }
 636
 637 static ssize_t iblock_show_configfs_dev_params(struct se_device *dev, char *b)
 638 {
 639         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 640         struct block_device *bd = ib_dev->ibd_bd;
 641         ssize_t bl = 0;
 642
 643         if (bd)
 644                 bl += sprintf(b + bl, "iBlock device: %pg", bd);
 645         if (ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)
 646                 bl += sprintf(b + bl, "  UDEV PATH: %s",
 647                                 ib_dev->ibd_udev_path);
 648         bl += sprintf(b + bl, "  readonly: %d\n", ib_dev->ibd_readonly);
 649
 650         bl += sprintf(b + bl, "        ");
 651         if (bd) {
 652                 bl += sprintf(b + bl, "Major: %d Minor: %d  %s\n",
 653                         MAJOR(bd->bd_dev), MINOR(bd->bd_dev),
 654                         "CLAIMED: IBLOCK");
 655         } else {
 656                 bl += sprintf(b + bl, "Major: 0 Minor: 0\n");
 657         }
 658
 659         return bl;
 660 }
 661
 662 static int
 663 iblock_alloc_bip(struct se_cmd *cmd, struct bio *bio,
 664                  struct sg_mapping_iter *miter)
 665 {
 666         struct se_device *dev = cmd->se_dev;
 667         struct blk_integrity *bi;
 668         struct bio_integrity_payload *bip;
 669         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 670         int rc;
 671         size_t resid, len;
 672
 673         bi = bdev_get_integrity(ib_dev->ibd_bd);
 674         if (!bi) {
 675                 pr_err("Unable to locate bio_integrity\n");
 676                 return -ENODEV;
 677         }
 678
 679         bip = bio_integrity_alloc(bio, GFP_NOIO, bio_max_segs(cmd->t_prot_nents));
 680         if (IS_ERR(bip)) {
 681                 pr_err("Unable to allocate bio_integrity_payload\n");
 682                 return PTR_ERR(bip);
 683         }
 684
 685         bip->bip_iter.bi_size = bio_integrity_bytes(bi, bio_sectors(bio));
 686         /* virtual start sector must be in integrity interval units */
 687         bip_set_seed(bip, bio->bi_iter.bi_sector >>
 688                                   (bi->interval_exp - SECTOR_SHIFT));
 689
 690         pr_debug("IBLOCK BIP Size: %u Sector: %llu\n", bip->bip_iter.bi_size,
 691                  (unsigned long long)bip->bip_iter.bi_sector);
 692
 693         resid = bip->bip_iter.bi_size;
 694         while (resid > 0 && sg_miter_next(miter)) {
 695
 696                 len = min_t(size_t, miter->length, resid);
 697                 rc = bio_integrity_add_page(bio, miter->page, len,
 698                                             offset_in_page(miter->addr));
 699                 if (rc != len) {
 700                         pr_err("bio_integrity_add_page() failed; %d\n", rc);
 701                         sg_miter_stop(miter);
 702                         return -ENOMEM;
 703                 }
 704
 705                 pr_debug("Added bio integrity page: %p length: %zu offset: %lu\n",
 706                           miter->page, len, offset_in_page(miter->addr));
 707
 708                 resid -= len;
 709                 if (len < miter->length)
 710                         miter->consumed -= miter->length - len;
 711         }
 712         sg_miter_stop(miter);
 713
 714         return 0;
 715 }
 716
 717 static sense_reason_t
 718 iblock_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 719                   enum dma_data_direction data_direction)
 720 {
 721         struct se_device *dev = cmd->se_dev;
 722         sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba);
 723         struct iblock_req *ibr;
 724         struct bio *bio;
 725         struct bio_list list;
 726         struct scatterlist *sg;
 727         u32 sg_num = sgl_nents;
 728         blk_opf_t opf;
 729         unsigned bio_cnt;
 730         int i, rc;
 731         struct sg_mapping_iter prot_miter;
 732         unsigned int miter_dir;
 733
 734         if (data_direction == DMA_TO_DEVICE) {
 735                 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 736                 /*
 737                  * Force writethrough using REQ_FUA if a volatile write cache
 738                  * is not enabled, or if initiator set the Force Unit Access bit.
 739                  */
 740                 opf = REQ_OP_WRITE;
 741                 miter_dir = SG_MITER_TO_SG;
 742                 if (bdev_fua(ib_dev->ibd_bd)) {
 743                         if (cmd->se_cmd_flags & SCF_FUA)
 744                                 opf |= REQ_FUA;
 745                         else if (!bdev_write_cache(ib_dev->ibd_bd))
 746                                 opf |= REQ_FUA;
 747                 }
 748         } else {
 749                 opf = REQ_OP_READ;
 750                 miter_dir = SG_MITER_FROM_SG;
 751         }
 752
 753         ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
 754         if (!ibr)
 755                 goto fail;
 756         cmd->priv = ibr;
 757
 758         if (!sgl_nents) {
 759                 refcount_set(&ibr->pending, 1);
 760                 iblock_complete_cmd(cmd);
 761                 return 0;
 762         }
 763
 764         bio = iblock_get_bio(cmd, block_lba, sgl_nents, opf);
 765         if (!bio)
 766                 goto fail_free_ibr;
 767
 768         bio_list_init(&list);
 769         bio_list_add(&list, bio);
 770
 771         refcount_set(&ibr->pending, 2);
 772         bio_cnt = 1;
 773
 774         if (cmd->prot_type && dev->dev_attrib.pi_prot_type)
 775                 sg_miter_start(&prot_miter, cmd->t_prot_sg, cmd->t_prot_nents,
 776                                miter_dir);
 777
 778         for_each_sg(sgl, sg, sgl_nents, i) {
 779                 /*
 780                  * XXX: if the length the device accepts is shorter than the
 781                  *      length of the S/G list entry this will cause and
 782                  *      endless loop.  Better hope no driver uses huge pages.
 783                  */
 784                 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
 785                                 != sg->length) {
 786                         if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
 787                                 rc = iblock_alloc_bip(cmd, bio, &prot_miter);
 788                                 if (rc)
 789                                         goto fail_put_bios;
 790                         }
 791
 792                         if (bio_cnt >= IBLOCK_MAX_BIO_PER_TASK) {
 793                                 iblock_submit_bios(&list);
 794                                 bio_cnt = 0;
 795                         }
 796
 797                         bio = iblock_get_bio(cmd, block_lba, sg_num, opf);
 798                         if (!bio)
 799                                 goto fail_put_bios;
 800
 801                         refcount_inc(&ibr->pending);
 802                         bio_list_add(&list, bio);
 803                         bio_cnt++;
 804                 }
 805
 806                 /* Always in 512 byte units for Linux/Block */
 807                 block_lba += sg->length >> SECTOR_SHIFT;
 808                 sg_num--;
 809         }
 810
 811         if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
 812                 rc = iblock_alloc_bip(cmd, bio, &prot_miter);
 813                 if (rc)
 814                         goto fail_put_bios;
 815         }
 816
 817         iblock_submit_bios(&list);
 818         iblock_complete_cmd(cmd);
 819         return 0;
 820
 821 fail_put_bios:
 822         while ((bio = bio_list_pop(&list)))
 823                 bio_put(bio);
 824 fail_free_ibr:
 825         kfree(ibr);
 826 fail:
 827         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 828 }
 829
 830 static sector_t iblock_get_alignment_offset_lbas(struct se_device *dev)
 831 {
 832         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 833         struct block_device *bd = ib_dev->ibd_bd;
 834         int ret;
 835
 836         ret = bdev_alignment_offset(bd);
 837         if (ret == -1)
 838                 return 0;
 839
 840         /* convert offset-bytes to offset-lbas */
 841         return ret / bdev_logical_block_size(bd);
 842 }
 843
 844 static unsigned int iblock_get_lbppbe(struct se_device *dev)
 845 {
 846         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 847         struct block_device *bd = ib_dev->ibd_bd;
 848         unsigned int logs_per_phys =
 849                 bdev_physical_block_size(bd) / bdev_logical_block_size(bd);
 850
 851         return ilog2(logs_per_phys);
 852 }
 853
 854 static unsigned int iblock_get_io_min(struct se_device *dev)
 855 {
 856         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 857         struct block_device *bd = ib_dev->ibd_bd;
 858
 859         return bdev_io_min(bd);
 860 }
 861
 862 static unsigned int iblock_get_io_opt(struct se_device *dev)
 863 {
 864         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 865         struct block_device *bd = ib_dev->ibd_bd;
 866
 867         return bdev_io_opt(bd);
 868 }
 869
 870 static struct sbc_ops iblock_sbc_ops = {
 871         .execute_rw             = iblock_execute_rw,
 872         .execute_sync_cache     = iblock_execute_sync_cache,
 873         .execute_write_same     = iblock_execute_write_same,
 874         .execute_unmap          = iblock_execute_unmap,
 875 };
 876
 877 static sense_reason_t
 878 iblock_parse_cdb(struct se_cmd *cmd)
 879 {
 880         return sbc_parse_cdb(cmd, &iblock_sbc_ops);
 881 }
 882
 883 static bool iblock_get_write_cache(struct se_device *dev)
 884 {
 885         return bdev_write_cache(IBLOCK_DEV(dev)->ibd_bd);
 886 }
 887
 888 static const struct target_backend_ops iblock_ops = {
 889         .name                   = "iblock",
 890         .inquiry_prod           = "IBLOCK",
 891         .inquiry_rev            = IBLOCK_VERSION,
 892         .owner                  = THIS_MODULE,
 893         .attach_hba             = iblock_attach_hba,
 894         .detach_hba             = iblock_detach_hba,
 895         .alloc_device           = iblock_alloc_device,
 896         .configure_device       = iblock_configure_device,
 897         .destroy_device         = iblock_destroy_device,
 898         .free_device            = iblock_free_device,
 899         .configure_unmap        = iblock_configure_unmap,
 900         .plug_device            = iblock_plug_device,
 901         .unplug_device          = iblock_unplug_device,
 902         .parse_cdb              = iblock_parse_cdb,
 903         .set_configfs_dev_params = iblock_set_configfs_dev_params,
 904         .show_configfs_dev_params = iblock_show_configfs_dev_params,
 905         .get_device_type        = sbc_get_device_type,
 906         .get_blocks             = iblock_get_blocks,
 907         .get_alignment_offset_lbas = iblock_get_alignment_offset_lbas,
 908         .get_lbppbe             = iblock_get_lbppbe,
 909         .get_io_min             = iblock_get_io_min,
 910         .get_io_opt             = iblock_get_io_opt,
 911         .get_write_cache        = iblock_get_write_cache,
 912         .tb_dev_attrib_attrs    = sbc_attrib_attrs,
 913 };
 914
 915 static int __init iblock_module_init(void)
 916 {
 917         return transport_backend_register(&iblock_ops);
 918 }
 919
 920 static void __exit iblock_module_exit(void)
 921 {
 922         target_backend_unregister(&iblock_ops);
 923 }
 924
 925 MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin");
 926 MODULE_AUTHOR("nab@Linux-iSCSI.org");
 927 MODULE_LICENSE("GPL");
 928
 929 module_init(iblock_module_init);
 930 module_exit(iblock_module_exit);