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 = mult_frac(queue_max_hw_sectors(q),
 128                         SECTOR_SIZE,
 129                         dev->dev_attrib.hw_block_size);
 130         dev->dev_attrib.hw_queue_depth = q->nr_requests;
 131
 132         /*
 133          * Enable write same emulation for IBLOCK and use 0xFFFF as
 134          * the smaller WRITE_SAME(10) only has a two-byte block count.
 135          */
 136         max_write_zeroes_sectors = bdev_write_zeroes_sectors(bd);
 137         if (max_write_zeroes_sectors)
 138                 dev->dev_attrib.max_write_same_len = max_write_zeroes_sectors;
 139         else
 140                 dev->dev_attrib.max_write_same_len = 0xFFFF;
 141
 142         if (bdev_nonrot(bd))
 143                 dev->dev_attrib.is_nonrot = 1;
 144
 145         bi = bdev_get_integrity(bd);
 146         if (bi) {
 147                 struct bio_set *bs = &ib_dev->ibd_bio_set;
 148
 149                 if (!strcmp(bi->profile->name, "T10-DIF-TYPE3-IP") ||
 150                     !strcmp(bi->profile->name, "T10-DIF-TYPE1-IP")) {
 151                         pr_err("IBLOCK export of blk_integrity: %s not"
 152                                " supported\n", bi->profile->name);
 153                         ret = -ENOSYS;
 154                         goto out_blkdev_put;
 155                 }
 156
 157                 if (!strcmp(bi->profile->name, "T10-DIF-TYPE3-CRC")) {
 158                         dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE3_PROT;
 159                 } else if (!strcmp(bi->profile->name, "T10-DIF-TYPE1-CRC")) {
 160                         dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE1_PROT;
 161                 }
 162
 163                 if (dev->dev_attrib.pi_prot_type) {
 164                         if (bioset_integrity_create(bs, IBLOCK_BIO_POOL_SIZE) < 0) {
 165                                 pr_err("Unable to allocate bioset for PI\n");
 166                                 ret = -ENOMEM;
 167                                 goto out_blkdev_put;
 168                         }
 169                         pr_debug("IBLOCK setup BIP bs->bio_integrity_pool: %p\n",
 170                                  &bs->bio_integrity_pool);
 171                 }
 172                 dev->dev_attrib.hw_pi_prot_type = dev->dev_attrib.pi_prot_type;
 173         }
 174
 175         return 0;
 176
 177 out_blkdev_put:
 178         blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
 179 out_free_bioset:
 180         bioset_exit(&ib_dev->ibd_bio_set);
 181 out:
 182         return ret;
 183 }
 184
 185 static void iblock_dev_call_rcu(struct rcu_head *p)
 186 {
 187         struct se_device *dev = container_of(p, struct se_device, rcu_head);
 188         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 189
 190         kfree(ib_dev->ibd_plug);
 191         kfree(ib_dev);
 192 }
 193
 194 static void iblock_free_device(struct se_device *dev)
 195 {
 196         call_rcu(&dev->rcu_head, iblock_dev_call_rcu);
 197 }
 198
 199 static void iblock_destroy_device(struct se_device *dev)
 200 {
 201         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 202
 203         if (ib_dev->ibd_bd != NULL)
 204                 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
 205         bioset_exit(&ib_dev->ibd_bio_set);
 206 }
 207
 208 static struct se_dev_plug *iblock_plug_device(struct se_device *se_dev)
 209 {
 210         struct iblock_dev *ib_dev = IBLOCK_DEV(se_dev);
 211         struct iblock_dev_plug *ib_dev_plug;
 212
 213         /*
 214          * Each se_device has a per cpu work this can be run from. We
 215          * shouldn't have multiple threads on the same cpu calling this
 216          * at the same time.
 217          */
 218         ib_dev_plug = &ib_dev->ibd_plug[raw_smp_processor_id()];
 219         if (test_and_set_bit(IBD_PLUGF_PLUGGED, &ib_dev_plug->flags))
 220                 return NULL;
 221
 222         blk_start_plug(&ib_dev_plug->blk_plug);
 223         return &ib_dev_plug->se_plug;
 224 }
 225
 226 static void iblock_unplug_device(struct se_dev_plug *se_plug)
 227 {
 228         struct iblock_dev_plug *ib_dev_plug = container_of(se_plug,
 229                                         struct iblock_dev_plug, se_plug);
 230
 231         blk_finish_plug(&ib_dev_plug->blk_plug);
 232         clear_bit(IBD_PLUGF_PLUGGED, &ib_dev_plug->flags);
 233 }
 234
 235 static sector_t iblock_get_blocks(struct se_device *dev)
 236 {
 237         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 238         u32 block_size = bdev_logical_block_size(ib_dev->ibd_bd);
 239         unsigned long long blocks_long =
 240                 div_u64(bdev_nr_bytes(ib_dev->ibd_bd), block_size) - 1;
 241
 242         if (block_size == dev->dev_attrib.block_size)
 243                 return blocks_long;
 244
 245         switch (block_size) {
 246         case 4096:
 247                 switch (dev->dev_attrib.block_size) {
 248                 case 2048:
 249                         blocks_long <<= 1;
 250                         break;
 251                 case 1024:
 252                         blocks_long <<= 2;
 253                         break;
 254                 case 512:
 255                         blocks_long <<= 3;
 256                         break;
 257                 default:
 258                         break;
 259                 }
 260                 break;
 261         case 2048:
 262                 switch (dev->dev_attrib.block_size) {
 263                 case 4096:
 264                         blocks_long >>= 1;
 265                         break;
 266                 case 1024:
 267                         blocks_long <<= 1;
 268                         break;
 269                 case 512:
 270                         blocks_long <<= 2;
 271                         break;
 272                 default:
 273                         break;
 274                 }
 275                 break;
 276         case 1024:
 277                 switch (dev->dev_attrib.block_size) {
 278                 case 4096:
 279                         blocks_long >>= 2;
 280                         break;
 281                 case 2048:
 282                         blocks_long >>= 1;
 283                         break;
 284                 case 512:
 285                         blocks_long <<= 1;
 286                         break;
 287                 default:
 288                         break;
 289                 }
 290                 break;
 291         case 512:
 292                 switch (dev->dev_attrib.block_size) {
 293                 case 4096:
 294                         blocks_long >>= 3;
 295                         break;
 296                 case 2048:
 297                         blocks_long >>= 2;
 298                         break;
 299                 case 1024:
 300                         blocks_long >>= 1;
 301                         break;
 302                 default:
 303                         break;
 304                 }
 305                 break;
 306         default:
 307                 break;
 308         }
 309
 310         return blocks_long;
 311 }
 312
 313 static void iblock_complete_cmd(struct se_cmd *cmd)
 314 {
 315         struct iblock_req *ibr = cmd->priv;
 316         u8 status;
 317
 318         if (!refcount_dec_and_test(&ibr->pending))
 319                 return;
 320
 321         if (atomic_read(&ibr->ib_bio_err_cnt))
 322                 status = SAM_STAT_CHECK_CONDITION;
 323         else
 324                 status = SAM_STAT_GOOD;
 325
 326         target_complete_cmd(cmd, status);
 327         kfree(ibr);
 328 }
 329
 330 static void iblock_bio_done(struct bio *bio)
 331 {
 332         struct se_cmd *cmd = bio->bi_private;
 333         struct iblock_req *ibr = cmd->priv;
 334
 335         if (bio->bi_status) {
 336                 pr_err("bio error: %p,  err: %d\n", bio, bio->bi_status);
 337                 /*
 338                  * Bump the ib_bio_err_cnt and release bio.
 339                  */
 340                 atomic_inc(&ibr->ib_bio_err_cnt);
 341                 smp_mb__after_atomic();
 342         }
 343
 344         bio_put(bio);
 345
 346         iblock_complete_cmd(cmd);
 347 }
 348
 349 static struct bio *iblock_get_bio(struct se_cmd *cmd, sector_t lba, u32 sg_num,
 350                                   blk_opf_t opf)
 351 {
 352         struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
 353         struct bio *bio;
 354
 355         /*
 356          * Only allocate as many vector entries as the bio code allows us to,
 357          * we'll loop later on until we have handled the whole request.
 358          */
 359         bio = bio_alloc_bioset(ib_dev->ibd_bd, bio_max_segs(sg_num), opf,
 360                                GFP_NOIO, &ib_dev->ibd_bio_set);
 361         if (!bio) {
 362                 pr_err("Unable to allocate memory for bio\n");
 363                 return NULL;
 364         }
 365
 366         bio->bi_private = cmd;
 367         bio->bi_end_io = &iblock_bio_done;
 368         bio->bi_iter.bi_sector = lba;
 369
 370         return bio;
 371 }
 372
 373 static void iblock_submit_bios(struct bio_list *list)
 374 {
 375         struct blk_plug plug;
 376         struct bio *bio;
 377         /*
 378          * The block layer handles nested plugs, so just plug/unplug to handle
 379          * fabric drivers that didn't support batching and multi bio cmds.
 380          */
 381         blk_start_plug(&plug);
 382         while ((bio = bio_list_pop(list)))
 383                 submit_bio(bio);
 384         blk_finish_plug(&plug);
 385 }
 386
 387 static void iblock_end_io_flush(struct bio *bio)
 388 {
 389         struct se_cmd *cmd = bio->bi_private;
 390
 391         if (bio->bi_status)
 392                 pr_err("IBLOCK: cache flush failed: %d\n", bio->bi_status);
 393
 394         if (cmd) {
 395                 if (bio->bi_status)
 396                         target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
 397                 else
 398                         target_complete_cmd(cmd, SAM_STAT_GOOD);
 399         }
 400
 401         bio_put(bio);
 402 }
 403
 404 /*
 405  * Implement SYCHRONIZE CACHE.  Note that we can't handle lba ranges and must
 406  * always flush the whole cache.
 407  */
 408 static sense_reason_t
 409 iblock_execute_sync_cache(struct se_cmd *cmd)
 410 {
 411         struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev);
 412         int immed = (cmd->t_task_cdb[1] & 0x2);
 413         struct bio *bio;
 414
 415         /*
 416          * If the Immediate bit is set, queue up the GOOD response
 417          * for this SYNCHRONIZE_CACHE op.
 418          */
 419         if (immed)
 420                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 421
 422         bio = bio_alloc(ib_dev->ibd_bd, 0, REQ_OP_WRITE | REQ_PREFLUSH,
 423                         GFP_KERNEL);
 424         bio->bi_end_io = iblock_end_io_flush;
 425         if (!immed)
 426                 bio->bi_private = cmd;
 427         submit_bio(bio);
 428         return 0;
 429 }
 430
 431 static sense_reason_t
 432 iblock_execute_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb)
 433 {
 434         struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
 435         struct se_device *dev = cmd->se_dev;
 436         int ret;
 437
 438         ret = blkdev_issue_discard(bdev,
 439                                    target_to_linux_sector(dev, lba),
 440                                    target_to_linux_sector(dev,  nolb),
 441                                    GFP_KERNEL);
 442         if (ret < 0) {
 443                 pr_err("blkdev_issue_discard() failed: %d\n", ret);
 444                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 445         }
 446
 447         return 0;
 448 }
 449
 450 static sense_reason_t
 451 iblock_execute_zero_out(struct block_device *bdev, struct se_cmd *cmd)
 452 {
 453         struct se_device *dev = cmd->se_dev;
 454         struct scatterlist *sg = &cmd->t_data_sg[0];
 455         unsigned char *buf, *not_zero;
 456         int ret;
 457
 458         buf = kmap(sg_page(sg)) + sg->offset;
 459         if (!buf)
 460                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 461         /*
 462          * Fall back to block_execute_write_same() slow-path if
 463          * incoming WRITE_SAME payload does not contain zeros.
 464          */
 465         not_zero = memchr_inv(buf, 0x00, cmd->data_length);
 466         kunmap(sg_page(sg));
 467
 468         if (not_zero)
 469                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 470
 471         ret = blkdev_issue_zeroout(bdev,
 472                                 target_to_linux_sector(dev, cmd->t_task_lba),
 473                                 target_to_linux_sector(dev,
 474                                         sbc_get_write_same_sectors(cmd)),
 475                                 GFP_KERNEL, BLKDEV_ZERO_NOUNMAP);
 476         if (ret)
 477                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 478
 479         target_complete_cmd(cmd, SAM_STAT_GOOD);
 480         return 0;
 481 }
 482
 483 static sense_reason_t
 484 iblock_execute_write_same(struct se_cmd *cmd)
 485 {
 486         struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd;
 487         struct iblock_req *ibr;
 488         struct scatterlist *sg;
 489         struct bio *bio;
 490         struct bio_list list;
 491         struct se_device *dev = cmd->se_dev;
 492         sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba);
 493         sector_t sectors = target_to_linux_sector(dev,
 494                                         sbc_get_write_same_sectors(cmd));
 495
 496         if (cmd->prot_op) {
 497                 pr_err("WRITE_SAME: Protection information with IBLOCK"
 498                        " backends not supported\n");
 499                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 500         }
 501
 502         if (!cmd->t_data_nents)
 503                 return TCM_INVALID_CDB_FIELD;
 504
 505         sg = &cmd->t_data_sg[0];
 506
 507         if (cmd->t_data_nents > 1 ||
 508             sg->length != cmd->se_dev->dev_attrib.block_size) {
 509                 pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u"
 510                         " block_size: %u\n", cmd->t_data_nents, sg->length,
 511                         cmd->se_dev->dev_attrib.block_size);
 512                 return TCM_INVALID_CDB_FIELD;
 513         }
 514
 515         if (bdev_write_zeroes_sectors(bdev)) {
 516                 if (!iblock_execute_zero_out(bdev, cmd))
 517                         return 0;
 518         }
 519
 520         ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
 521         if (!ibr)
 522                 goto fail;
 523         cmd->priv = ibr;
 524
 525         bio = iblock_get_bio(cmd, block_lba, 1, REQ_OP_WRITE);
 526         if (!bio)
 527                 goto fail_free_ibr;
 528
 529         bio_list_init(&list);
 530         bio_list_add(&list, bio);
 531
 532         refcount_set(&ibr->pending, 1);
 533
 534         while (sectors) {
 535                 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
 536                                 != sg->length) {
 537
 538                         bio = iblock_get_bio(cmd, block_lba, 1, REQ_OP_WRITE);
 539                         if (!bio)
 540                                 goto fail_put_bios;
 541
 542                         refcount_inc(&ibr->pending);
 543                         bio_list_add(&list, bio);
 544                 }
 545
 546                 /* Always in 512 byte units for Linux/Block */
 547                 block_lba += sg->length >> SECTOR_SHIFT;
 548                 sectors -= sg->length >> SECTOR_SHIFT;
 549         }
 550
 551         iblock_submit_bios(&list);
 552         return 0;
 553
 554 fail_put_bios:
 555         while ((bio = bio_list_pop(&list)))
 556                 bio_put(bio);
 557 fail_free_ibr:
 558         kfree(ibr);
 559 fail:
 560         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 561 }
 562
 563 enum {
 564         Opt_udev_path, Opt_readonly, Opt_force, Opt_err
 565 };
 566
 567 static match_table_t tokens = {
 568         {Opt_udev_path, "udev_path=%s"},
 569         {Opt_readonly, "readonly=%d"},
 570         {Opt_force, "force=%d"},
 571         {Opt_err, NULL}
 572 };
 573
 574 static ssize_t iblock_set_configfs_dev_params(struct se_device *dev,
 575                 const char *page, ssize_t count)
 576 {
 577         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 578         char *orig, *ptr, *arg_p, *opts;
 579         substring_t args[MAX_OPT_ARGS];
 580         int ret = 0, token;
 581         unsigned long tmp_readonly;
 582
 583         opts = kstrdup(page, GFP_KERNEL);
 584         if (!opts)
 585                 return -ENOMEM;
 586
 587         orig = opts;
 588
 589         while ((ptr = strsep(&opts, ",\n")) != NULL) {
 590                 if (!*ptr)
 591                         continue;
 592
 593                 token = match_token(ptr, tokens, args);
 594                 switch (token) {
 595                 case Opt_udev_path:
 596                         if (ib_dev->ibd_bd) {
 597                                 pr_err("Unable to set udev_path= while"
 598                                         " ib_dev->ibd_bd exists\n");
 599                                 ret = -EEXIST;
 600                                 goto out;
 601                         }
 602                         if (match_strlcpy(ib_dev->ibd_udev_path, &args[0],
 603                                 SE_UDEV_PATH_LEN) == 0) {
 604                                 ret = -EINVAL;
 605                                 break;
 606                         }
 607                         pr_debug("IBLOCK: Referencing UDEV path: %s\n",
 608                                         ib_dev->ibd_udev_path);
 609                         ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH;
 610                         break;
 611                 case Opt_readonly:
 612                         arg_p = match_strdup(&args[0]);
 613                         if (!arg_p) {
 614                                 ret = -ENOMEM;
 615                                 break;
 616                         }
 617                         ret = kstrtoul(arg_p, 0, &tmp_readonly);
 618                         kfree(arg_p);
 619                         if (ret < 0) {
 620                                 pr_err("kstrtoul() failed for"
 621                                                 " readonly=\n");
 622                                 goto out;
 623                         }
 624                         ib_dev->ibd_readonly = tmp_readonly;
 625                         pr_debug("IBLOCK: readonly: %d\n", ib_dev->ibd_readonly);
 626                         break;
 627                 case Opt_force:
 628                         break;
 629                 default:
 630                         break;
 631                 }
 632         }
 633
 634 out:
 635         kfree(orig);
 636         return (!ret) ? count : ret;
 637 }
 638
 639 static ssize_t iblock_show_configfs_dev_params(struct se_device *dev, char *b)
 640 {
 641         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 642         struct block_device *bd = ib_dev->ibd_bd;
 643         ssize_t bl = 0;
 644
 645         if (bd)
 646                 bl += sprintf(b + bl, "iBlock device: %pg", bd);
 647         if (ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)
 648                 bl += sprintf(b + bl, "  UDEV PATH: %s",
 649                                 ib_dev->ibd_udev_path);
 650         bl += sprintf(b + bl, "  readonly: %d\n", ib_dev->ibd_readonly);
 651
 652         bl += sprintf(b + bl, "        ");
 653         if (bd) {
 654                 bl += sprintf(b + bl, "Major: %d Minor: %d  %s\n",
 655                         MAJOR(bd->bd_dev), MINOR(bd->bd_dev),
 656                         "CLAIMED: IBLOCK");
 657         } else {
 658                 bl += sprintf(b + bl, "Major: 0 Minor: 0\n");
 659         }
 660
 661         return bl;
 662 }
 663
 664 static int
 665 iblock_alloc_bip(struct se_cmd *cmd, struct bio *bio,
 666                  struct sg_mapping_iter *miter)
 667 {
 668         struct se_device *dev = cmd->se_dev;
 669         struct blk_integrity *bi;
 670         struct bio_integrity_payload *bip;
 671         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 672         int rc;
 673         size_t resid, len;
 674
 675         bi = bdev_get_integrity(ib_dev->ibd_bd);
 676         if (!bi) {
 677                 pr_err("Unable to locate bio_integrity\n");
 678                 return -ENODEV;
 679         }
 680
 681         bip = bio_integrity_alloc(bio, GFP_NOIO, bio_max_segs(cmd->t_prot_nents));
 682         if (IS_ERR(bip)) {
 683                 pr_err("Unable to allocate bio_integrity_payload\n");
 684                 return PTR_ERR(bip);
 685         }
 686
 687         bip->bip_iter.bi_size = bio_integrity_bytes(bi, bio_sectors(bio));
 688         /* virtual start sector must be in integrity interval units */
 689         bip_set_seed(bip, bio->bi_iter.bi_sector >>
 690                                   (bi->interval_exp - SECTOR_SHIFT));
 691
 692         pr_debug("IBLOCK BIP Size: %u Sector: %llu\n", bip->bip_iter.bi_size,
 693                  (unsigned long long)bip->bip_iter.bi_sector);
 694
 695         resid = bip->bip_iter.bi_size;
 696         while (resid > 0 && sg_miter_next(miter)) {
 697
 698                 len = min_t(size_t, miter->length, resid);
 699                 rc = bio_integrity_add_page(bio, miter->page, len,
 700                                             offset_in_page(miter->addr));
 701                 if (rc != len) {
 702                         pr_err("bio_integrity_add_page() failed; %d\n", rc);
 703                         sg_miter_stop(miter);
 704                         return -ENOMEM;
 705                 }
 706
 707                 pr_debug("Added bio integrity page: %p length: %zu offset: %lu\n",
 708                           miter->page, len, offset_in_page(miter->addr));
 709
 710                 resid -= len;
 711                 if (len < miter->length)
 712                         miter->consumed -= miter->length - len;
 713         }
 714         sg_miter_stop(miter);
 715
 716         return 0;
 717 }
 718
 719 static sense_reason_t
 720 iblock_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 721                   enum dma_data_direction data_direction)
 722 {
 723         struct se_device *dev = cmd->se_dev;
 724         sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba);
 725         struct iblock_req *ibr;
 726         struct bio *bio;
 727         struct bio_list list;
 728         struct scatterlist *sg;
 729         u32 sg_num = sgl_nents;
 730         blk_opf_t opf;
 731         unsigned bio_cnt;
 732         int i, rc;
 733         struct sg_mapping_iter prot_miter;
 734         unsigned int miter_dir;
 735
 736         if (data_direction == DMA_TO_DEVICE) {
 737                 struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 738                 /*
 739                  * Force writethrough using REQ_FUA if a volatile write cache
 740                  * is not enabled, or if initiator set the Force Unit Access bit.
 741                  */
 742                 opf = REQ_OP_WRITE;
 743                 miter_dir = SG_MITER_TO_SG;
 744                 if (bdev_fua(ib_dev->ibd_bd)) {
 745                         if (cmd->se_cmd_flags & SCF_FUA)
 746                                 opf |= REQ_FUA;
 747                         else if (!bdev_write_cache(ib_dev->ibd_bd))
 748                                 opf |= REQ_FUA;
 749                 }
 750         } else {
 751                 opf = REQ_OP_READ;
 752                 miter_dir = SG_MITER_FROM_SG;
 753         }
 754
 755         ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL);
 756         if (!ibr)
 757                 goto fail;
 758         cmd->priv = ibr;
 759
 760         if (!sgl_nents) {
 761                 refcount_set(&ibr->pending, 1);
 762                 iblock_complete_cmd(cmd);
 763                 return 0;
 764         }
 765
 766         bio = iblock_get_bio(cmd, block_lba, sgl_nents, opf);
 767         if (!bio)
 768                 goto fail_free_ibr;
 769
 770         bio_list_init(&list);
 771         bio_list_add(&list, bio);
 772
 773         refcount_set(&ibr->pending, 2);
 774         bio_cnt = 1;
 775
 776         if (cmd->prot_type && dev->dev_attrib.pi_prot_type)
 777                 sg_miter_start(&prot_miter, cmd->t_prot_sg, cmd->t_prot_nents,
 778                                miter_dir);
 779
 780         for_each_sg(sgl, sg, sgl_nents, i) {
 781                 /*
 782                  * XXX: if the length the device accepts is shorter than the
 783                  *      length of the S/G list entry this will cause and
 784                  *      endless loop.  Better hope no driver uses huge pages.
 785                  */
 786                 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
 787                                 != sg->length) {
 788                         if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
 789                                 rc = iblock_alloc_bip(cmd, bio, &prot_miter);
 790                                 if (rc)
 791                                         goto fail_put_bios;
 792                         }
 793
 794                         if (bio_cnt >= IBLOCK_MAX_BIO_PER_TASK) {
 795                                 iblock_submit_bios(&list);
 796                                 bio_cnt = 0;
 797                         }
 798
 799                         bio = iblock_get_bio(cmd, block_lba, sg_num, opf);
 800                         if (!bio)
 801                                 goto fail_put_bios;
 802
 803                         refcount_inc(&ibr->pending);
 804                         bio_list_add(&list, bio);
 805                         bio_cnt++;
 806                 }
 807
 808                 /* Always in 512 byte units for Linux/Block */
 809                 block_lba += sg->length >> SECTOR_SHIFT;
 810                 sg_num--;
 811         }
 812
 813         if (cmd->prot_type && dev->dev_attrib.pi_prot_type) {
 814                 rc = iblock_alloc_bip(cmd, bio, &prot_miter);
 815                 if (rc)
 816                         goto fail_put_bios;
 817         }
 818
 819         iblock_submit_bios(&list);
 820         iblock_complete_cmd(cmd);
 821         return 0;
 822
 823 fail_put_bios:
 824         while ((bio = bio_list_pop(&list)))
 825                 bio_put(bio);
 826 fail_free_ibr:
 827         kfree(ibr);
 828 fail:
 829         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 830 }
 831
 832 static sector_t iblock_get_alignment_offset_lbas(struct se_device *dev)
 833 {
 834         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 835         struct block_device *bd = ib_dev->ibd_bd;
 836         int ret;
 837
 838         ret = bdev_alignment_offset(bd);
 839         if (ret == -1)
 840                 return 0;
 841
 842         /* convert offset-bytes to offset-lbas */
 843         return ret / bdev_logical_block_size(bd);
 844 }
 845
 846 static unsigned int iblock_get_lbppbe(struct se_device *dev)
 847 {
 848         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 849         struct block_device *bd = ib_dev->ibd_bd;
 850         unsigned int logs_per_phys =
 851                 bdev_physical_block_size(bd) / bdev_logical_block_size(bd);
 852
 853         return ilog2(logs_per_phys);
 854 }
 855
 856 static unsigned int iblock_get_io_min(struct se_device *dev)
 857 {
 858         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 859         struct block_device *bd = ib_dev->ibd_bd;
 860
 861         return bdev_io_min(bd);
 862 }
 863
 864 static unsigned int iblock_get_io_opt(struct se_device *dev)
 865 {
 866         struct iblock_dev *ib_dev = IBLOCK_DEV(dev);
 867         struct block_device *bd = ib_dev->ibd_bd;
 868
 869         return bdev_io_opt(bd);
 870 }
 871
 872 static struct sbc_ops iblock_sbc_ops = {
 873         .execute_rw             = iblock_execute_rw,
 874         .execute_sync_cache     = iblock_execute_sync_cache,
 875         .execute_write_same     = iblock_execute_write_same,
 876         .execute_unmap          = iblock_execute_unmap,
 877 };
 878
 879 static sense_reason_t
 880 iblock_parse_cdb(struct se_cmd *cmd)
 881 {
 882         return sbc_parse_cdb(cmd, &iblock_sbc_ops);
 883 }
 884
 885 static bool iblock_get_write_cache(struct se_device *dev)
 886 {
 887         return bdev_write_cache(IBLOCK_DEV(dev)->ibd_bd);
 888 }
 889
 890 static const struct target_backend_ops iblock_ops = {
 891         .name                   = "iblock",
 892         .inquiry_prod           = "IBLOCK",
 893         .inquiry_rev            = IBLOCK_VERSION,
 894         .owner                  = THIS_MODULE,
 895         .attach_hba             = iblock_attach_hba,
 896         .detach_hba             = iblock_detach_hba,
 897         .alloc_device           = iblock_alloc_device,
 898         .configure_device       = iblock_configure_device,
 899         .destroy_device         = iblock_destroy_device,
 900         .free_device            = iblock_free_device,
 901         .configure_unmap        = iblock_configure_unmap,
 902         .plug_device            = iblock_plug_device,
 903         .unplug_device          = iblock_unplug_device,
 904         .parse_cdb              = iblock_parse_cdb,
 905         .set_configfs_dev_params = iblock_set_configfs_dev_params,
 906         .show_configfs_dev_params = iblock_show_configfs_dev_params,
 907         .get_device_type        = sbc_get_device_type,
 908         .get_blocks             = iblock_get_blocks,
 909         .get_alignment_offset_lbas = iblock_get_alignment_offset_lbas,
 910         .get_lbppbe             = iblock_get_lbppbe,
 911         .get_io_min             = iblock_get_io_min,
 912         .get_io_opt             = iblock_get_io_opt,
 913         .get_write_cache        = iblock_get_write_cache,
 914         .tb_dev_attrib_attrs    = sbc_attrib_attrs,
 915 };
 916
 917 static int __init iblock_module_init(void)
 918 {
 919         return transport_backend_register(&iblock_ops);
 920 }
 921
 922 static void __exit iblock_module_exit(void)
 923 {
 924         target_backend_unregister(&iblock_ops);
 925 }
 926
 927 MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin");
 928 MODULE_AUTHOR("nab@Linux-iSCSI.org");
 929 MODULE_LICENSE("GPL");
 930
 931 module_init(iblock_module_init);
 932 module_exit(iblock_module_exit);