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 int iblock_configure_device(struct se_device *dev) 80 { 81 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 82 struct request_queue *q; 83 struct block_device *bd = NULL; 84 struct blk_integrity *bi; 85 fmode_t mode; 86 unsigned int max_write_zeroes_sectors; 87 int ret; 88 89 if (!(ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)) { 90 pr_err("Missing udev_path= parameters for IBLOCK\n"); 91 return -EINVAL; 92 } 93 94 ret = bioset_init(&ib_dev->ibd_bio_set, IBLOCK_BIO_POOL_SIZE, 0, BIOSET_NEED_BVECS); 95 if (ret) { 96 pr_err("IBLOCK: Unable to create bioset\n"); 97 goto out; 98 } 99 100 pr_debug( "IBLOCK: Claiming struct block_device: %s\n", 101 ib_dev->ibd_udev_path); 102 103 mode = FMODE_READ|FMODE_EXCL; 104 if (!ib_dev->ibd_readonly) 105 mode |= FMODE_WRITE; 106 else 107 dev->dev_flags |= DF_READ_ONLY; 108 109 bd = blkdev_get_by_path(ib_dev->ibd_udev_path, mode, ib_dev); 110 if (IS_ERR(bd)) { 111 ret = PTR_ERR(bd); 112 goto out_free_bioset; 113 } 114 ib_dev->ibd_bd = bd; 115 116 q = bdev_get_queue(bd); 117 118 dev->dev_attrib.hw_block_size = bdev_logical_block_size(bd); 119 dev->dev_attrib.hw_max_sectors = queue_max_hw_sectors(q); 120 dev->dev_attrib.hw_queue_depth = q->nr_requests; 121 122 if (target_configure_unmap_from_queue(&dev->dev_attrib, bd)) 123 pr_debug("IBLOCK: BLOCK Discard support available," 124 " disabled by default\n"); 125 126 /* 127 * Enable write same emulation for IBLOCK and use 0xFFFF as 128 * the smaller WRITE_SAME(10) only has a two-byte block count. 129 */ 130 max_write_zeroes_sectors = bdev_write_zeroes_sectors(bd); 131 if (max_write_zeroes_sectors) 132 dev->dev_attrib.max_write_same_len = max_write_zeroes_sectors; 133 else 134 dev->dev_attrib.max_write_same_len = 0xFFFF; 135 136 if (bdev_nonrot(bd)) 137 dev->dev_attrib.is_nonrot = 1; 138 139 bi = bdev_get_integrity(bd); 140 if (bi) { 141 struct bio_set *bs = &ib_dev->ibd_bio_set; 142 143 if (!strcmp(bi->profile->name, "T10-DIF-TYPE3-IP") || 144 !strcmp(bi->profile->name, "T10-DIF-TYPE1-IP")) { 145 pr_err("IBLOCK export of blk_integrity: %s not" 146 " supported\n", bi->profile->name); 147 ret = -ENOSYS; 148 goto out_blkdev_put; 149 } 150 151 if (!strcmp(bi->profile->name, "T10-DIF-TYPE3-CRC")) { 152 dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE3_PROT; 153 } else if (!strcmp(bi->profile->name, "T10-DIF-TYPE1-CRC")) { 154 dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE1_PROT; 155 } 156 157 if (dev->dev_attrib.pi_prot_type) { 158 if (bioset_integrity_create(bs, IBLOCK_BIO_POOL_SIZE) < 0) { 159 pr_err("Unable to allocate bioset for PI\n"); 160 ret = -ENOMEM; 161 goto out_blkdev_put; 162 } 163 pr_debug("IBLOCK setup BIP bs->bio_integrity_pool: %p\n", 164 &bs->bio_integrity_pool); 165 } 166 dev->dev_attrib.hw_pi_prot_type = dev->dev_attrib.pi_prot_type; 167 } 168 169 return 0; 170 171 out_blkdev_put: 172 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL); 173 out_free_bioset: 174 bioset_exit(&ib_dev->ibd_bio_set); 175 out: 176 return ret; 177 } 178 179 static void iblock_dev_call_rcu(struct rcu_head *p) 180 { 181 struct se_device *dev = container_of(p, struct se_device, rcu_head); 182 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 183 184 kfree(ib_dev->ibd_plug); 185 kfree(ib_dev); 186 } 187 188 static void iblock_free_device(struct se_device *dev) 189 { 190 call_rcu(&dev->rcu_head, iblock_dev_call_rcu); 191 } 192 193 static void iblock_destroy_device(struct se_device *dev) 194 { 195 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 196 197 if (ib_dev->ibd_bd != NULL) 198 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL); 199 bioset_exit(&ib_dev->ibd_bio_set); 200 } 201 202 static struct se_dev_plug *iblock_plug_device(struct se_device *se_dev) 203 { 204 struct iblock_dev *ib_dev = IBLOCK_DEV(se_dev); 205 struct iblock_dev_plug *ib_dev_plug; 206 207 /* 208 * Each se_device has a per cpu work this can be run from. We 209 * shouldn't have multiple threads on the same cpu calling this 210 * at the same time. 211 */ 212 ib_dev_plug = &ib_dev->ibd_plug[raw_smp_processor_id()]; 213 if (test_and_set_bit(IBD_PLUGF_PLUGGED, &ib_dev_plug->flags)) 214 return NULL; 215 216 blk_start_plug(&ib_dev_plug->blk_plug); 217 return &ib_dev_plug->se_plug; 218 } 219 220 static void iblock_unplug_device(struct se_dev_plug *se_plug) 221 { 222 struct iblock_dev_plug *ib_dev_plug = container_of(se_plug, 223 struct iblock_dev_plug, se_plug); 224 225 blk_finish_plug(&ib_dev_plug->blk_plug); 226 clear_bit(IBD_PLUGF_PLUGGED, &ib_dev_plug->flags); 227 } 228 229 static unsigned long long iblock_emulate_read_cap_with_block_size( 230 struct se_device *dev, 231 struct block_device *bd, 232 struct request_queue *q) 233 { 234 u32 block_size = bdev_logical_block_size(bd); 235 unsigned long long blocks_long = 236 div_u64(bdev_nr_bytes(bd), block_size) - 1; 237 238 if (block_size == dev->dev_attrib.block_size) 239 return blocks_long; 240 241 switch (block_size) { 242 case 4096: 243 switch (dev->dev_attrib.block_size) { 244 case 2048: 245 blocks_long <<= 1; 246 break; 247 case 1024: 248 blocks_long <<= 2; 249 break; 250 case 512: 251 blocks_long <<= 3; 252 break; 253 default: 254 break; 255 } 256 break; 257 case 2048: 258 switch (dev->dev_attrib.block_size) { 259 case 4096: 260 blocks_long >>= 1; 261 break; 262 case 1024: 263 blocks_long <<= 1; 264 break; 265 case 512: 266 blocks_long <<= 2; 267 break; 268 default: 269 break; 270 } 271 break; 272 case 1024: 273 switch (dev->dev_attrib.block_size) { 274 case 4096: 275 blocks_long >>= 2; 276 break; 277 case 2048: 278 blocks_long >>= 1; 279 break; 280 case 512: 281 blocks_long <<= 1; 282 break; 283 default: 284 break; 285 } 286 break; 287 case 512: 288 switch (dev->dev_attrib.block_size) { 289 case 4096: 290 blocks_long >>= 3; 291 break; 292 case 2048: 293 blocks_long >>= 2; 294 break; 295 case 1024: 296 blocks_long >>= 1; 297 break; 298 default: 299 break; 300 } 301 break; 302 default: 303 break; 304 } 305 306 return blocks_long; 307 } 308 309 static void iblock_complete_cmd(struct se_cmd *cmd) 310 { 311 struct iblock_req *ibr = cmd->priv; 312 u8 status; 313 314 if (!refcount_dec_and_test(&ibr->pending)) 315 return; 316 317 if (atomic_read(&ibr->ib_bio_err_cnt)) 318 status = SAM_STAT_CHECK_CONDITION; 319 else 320 status = SAM_STAT_GOOD; 321 322 target_complete_cmd(cmd, status); 323 kfree(ibr); 324 } 325 326 static void iblock_bio_done(struct bio *bio) 327 { 328 struct se_cmd *cmd = bio->bi_private; 329 struct iblock_req *ibr = cmd->priv; 330 331 if (bio->bi_status) { 332 pr_err("bio error: %p, err: %d\n", bio, bio->bi_status); 333 /* 334 * Bump the ib_bio_err_cnt and release bio. 335 */ 336 atomic_inc(&ibr->ib_bio_err_cnt); 337 smp_mb__after_atomic(); 338 } 339 340 bio_put(bio); 341 342 iblock_complete_cmd(cmd); 343 } 344 345 static struct bio *iblock_get_bio(struct se_cmd *cmd, sector_t lba, u32 sg_num, 346 unsigned int opf) 347 { 348 struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev); 349 struct bio *bio; 350 351 /* 352 * Only allocate as many vector entries as the bio code allows us to, 353 * we'll loop later on until we have handled the whole request. 354 */ 355 bio = bio_alloc_bioset(ib_dev->ibd_bd, bio_max_segs(sg_num), opf, 356 GFP_NOIO, &ib_dev->ibd_bio_set); 357 if (!bio) { 358 pr_err("Unable to allocate memory for bio\n"); 359 return NULL; 360 } 361 362 bio->bi_private = cmd; 363 bio->bi_end_io = &iblock_bio_done; 364 bio->bi_iter.bi_sector = lba; 365 366 return bio; 367 } 368 369 static void iblock_submit_bios(struct bio_list *list) 370 { 371 struct blk_plug plug; 372 struct bio *bio; 373 /* 374 * The block layer handles nested plugs, so just plug/unplug to handle 375 * fabric drivers that didn't support batching and multi bio cmds. 376 */ 377 blk_start_plug(&plug); 378 while ((bio = bio_list_pop(list))) 379 submit_bio(bio); 380 blk_finish_plug(&plug); 381 } 382 383 static void iblock_end_io_flush(struct bio *bio) 384 { 385 struct se_cmd *cmd = bio->bi_private; 386 387 if (bio->bi_status) 388 pr_err("IBLOCK: cache flush failed: %d\n", bio->bi_status); 389 390 if (cmd) { 391 if (bio->bi_status) 392 target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION); 393 else 394 target_complete_cmd(cmd, SAM_STAT_GOOD); 395 } 396 397 bio_put(bio); 398 } 399 400 /* 401 * Implement SYCHRONIZE CACHE. Note that we can't handle lba ranges and must 402 * always flush the whole cache. 403 */ 404 static sense_reason_t 405 iblock_execute_sync_cache(struct se_cmd *cmd) 406 { 407 struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev); 408 int immed = (cmd->t_task_cdb[1] & 0x2); 409 struct bio *bio; 410 411 /* 412 * If the Immediate bit is set, queue up the GOOD response 413 * for this SYNCHRONIZE_CACHE op. 414 */ 415 if (immed) 416 target_complete_cmd(cmd, SAM_STAT_GOOD); 417 418 bio = bio_alloc(ib_dev->ibd_bd, 0, REQ_OP_WRITE | REQ_PREFLUSH, 419 GFP_KERNEL); 420 bio->bi_end_io = iblock_end_io_flush; 421 if (!immed) 422 bio->bi_private = cmd; 423 submit_bio(bio); 424 return 0; 425 } 426 427 static sense_reason_t 428 iblock_execute_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb) 429 { 430 struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd; 431 struct se_device *dev = cmd->se_dev; 432 int ret; 433 434 ret = blkdev_issue_discard(bdev, 435 target_to_linux_sector(dev, lba), 436 target_to_linux_sector(dev, nolb), 437 GFP_KERNEL); 438 if (ret < 0) { 439 pr_err("blkdev_issue_discard() failed: %d\n", ret); 440 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 441 } 442 443 return 0; 444 } 445 446 static sense_reason_t 447 iblock_execute_zero_out(struct block_device *bdev, struct se_cmd *cmd) 448 { 449 struct se_device *dev = cmd->se_dev; 450 struct scatterlist *sg = &cmd->t_data_sg[0]; 451 unsigned char *buf, *not_zero; 452 int ret; 453 454 buf = kmap(sg_page(sg)) + sg->offset; 455 if (!buf) 456 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 457 /* 458 * Fall back to block_execute_write_same() slow-path if 459 * incoming WRITE_SAME payload does not contain zeros. 460 */ 461 not_zero = memchr_inv(buf, 0x00, cmd->data_length); 462 kunmap(sg_page(sg)); 463 464 if (not_zero) 465 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 466 467 ret = blkdev_issue_zeroout(bdev, 468 target_to_linux_sector(dev, cmd->t_task_lba), 469 target_to_linux_sector(dev, 470 sbc_get_write_same_sectors(cmd)), 471 GFP_KERNEL, BLKDEV_ZERO_NOUNMAP); 472 if (ret) 473 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 474 475 target_complete_cmd(cmd, SAM_STAT_GOOD); 476 return 0; 477 } 478 479 static sense_reason_t 480 iblock_execute_write_same(struct se_cmd *cmd) 481 { 482 struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd; 483 struct iblock_req *ibr; 484 struct scatterlist *sg; 485 struct bio *bio; 486 struct bio_list list; 487 struct se_device *dev = cmd->se_dev; 488 sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba); 489 sector_t sectors = target_to_linux_sector(dev, 490 sbc_get_write_same_sectors(cmd)); 491 492 if (cmd->prot_op) { 493 pr_err("WRITE_SAME: Protection information with IBLOCK" 494 " backends not supported\n"); 495 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 496 } 497 sg = &cmd->t_data_sg[0]; 498 499 if (cmd->t_data_nents > 1 || 500 sg->length != cmd->se_dev->dev_attrib.block_size) { 501 pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u" 502 " block_size: %u\n", cmd->t_data_nents, sg->length, 503 cmd->se_dev->dev_attrib.block_size); 504 return TCM_INVALID_CDB_FIELD; 505 } 506 507 if (bdev_write_zeroes_sectors(bdev)) { 508 if (!iblock_execute_zero_out(bdev, cmd)) 509 return 0; 510 } 511 512 ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL); 513 if (!ibr) 514 goto fail; 515 cmd->priv = ibr; 516 517 bio = iblock_get_bio(cmd, block_lba, 1, REQ_OP_WRITE); 518 if (!bio) 519 goto fail_free_ibr; 520 521 bio_list_init(&list); 522 bio_list_add(&list, bio); 523 524 refcount_set(&ibr->pending, 1); 525 526 while (sectors) { 527 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset) 528 != sg->length) { 529 530 bio = iblock_get_bio(cmd, block_lba, 1, REQ_OP_WRITE); 531 if (!bio) 532 goto fail_put_bios; 533 534 refcount_inc(&ibr->pending); 535 bio_list_add(&list, bio); 536 } 537 538 /* Always in 512 byte units for Linux/Block */ 539 block_lba += sg->length >> SECTOR_SHIFT; 540 sectors -= sg->length >> SECTOR_SHIFT; 541 } 542 543 iblock_submit_bios(&list); 544 return 0; 545 546 fail_put_bios: 547 while ((bio = bio_list_pop(&list))) 548 bio_put(bio); 549 fail_free_ibr: 550 kfree(ibr); 551 fail: 552 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 553 } 554 555 enum { 556 Opt_udev_path, Opt_readonly, Opt_force, Opt_err 557 }; 558 559 static match_table_t tokens = { 560 {Opt_udev_path, "udev_path=%s"}, 561 {Opt_readonly, "readonly=%d"}, 562 {Opt_force, "force=%d"}, 563 {Opt_err, NULL} 564 }; 565 566 static ssize_t iblock_set_configfs_dev_params(struct se_device *dev, 567 const char *page, ssize_t count) 568 { 569 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 570 char *orig, *ptr, *arg_p, *opts; 571 substring_t args[MAX_OPT_ARGS]; 572 int ret = 0, token; 573 unsigned long tmp_readonly; 574 575 opts = kstrdup(page, GFP_KERNEL); 576 if (!opts) 577 return -ENOMEM; 578 579 orig = opts; 580 581 while ((ptr = strsep(&opts, ",\n")) != NULL) { 582 if (!*ptr) 583 continue; 584 585 token = match_token(ptr, tokens, args); 586 switch (token) { 587 case Opt_udev_path: 588 if (ib_dev->ibd_bd) { 589 pr_err("Unable to set udev_path= while" 590 " ib_dev->ibd_bd exists\n"); 591 ret = -EEXIST; 592 goto out; 593 } 594 if (match_strlcpy(ib_dev->ibd_udev_path, &args[0], 595 SE_UDEV_PATH_LEN) == 0) { 596 ret = -EINVAL; 597 break; 598 } 599 pr_debug("IBLOCK: Referencing UDEV path: %s\n", 600 ib_dev->ibd_udev_path); 601 ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH; 602 break; 603 case Opt_readonly: 604 arg_p = match_strdup(&args[0]); 605 if (!arg_p) { 606 ret = -ENOMEM; 607 break; 608 } 609 ret = kstrtoul(arg_p, 0, &tmp_readonly); 610 kfree(arg_p); 611 if (ret < 0) { 612 pr_err("kstrtoul() failed for" 613 " readonly=\n"); 614 goto out; 615 } 616 ib_dev->ibd_readonly = tmp_readonly; 617 pr_debug("IBLOCK: readonly: %d\n", ib_dev->ibd_readonly); 618 break; 619 case Opt_force: 620 break; 621 default: 622 break; 623 } 624 } 625 626 out: 627 kfree(orig); 628 return (!ret) ? count : ret; 629 } 630 631 static ssize_t iblock_show_configfs_dev_params(struct se_device *dev, char *b) 632 { 633 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 634 struct block_device *bd = ib_dev->ibd_bd; 635 ssize_t bl = 0; 636 637 if (bd) 638 bl += sprintf(b + bl, "iBlock device: %pg", bd); 639 if (ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH) 640 bl += sprintf(b + bl, " UDEV PATH: %s", 641 ib_dev->ibd_udev_path); 642 bl += sprintf(b + bl, " readonly: %d\n", ib_dev->ibd_readonly); 643 644 bl += sprintf(b + bl, " "); 645 if (bd) { 646 bl += sprintf(b + bl, "Major: %d Minor: %d %s\n", 647 MAJOR(bd->bd_dev), MINOR(bd->bd_dev), 648 "CLAIMED: IBLOCK"); 649 } else { 650 bl += sprintf(b + bl, "Major: 0 Minor: 0\n"); 651 } 652 653 return bl; 654 } 655 656 static int 657 iblock_alloc_bip(struct se_cmd *cmd, struct bio *bio, 658 struct sg_mapping_iter *miter) 659 { 660 struct se_device *dev = cmd->se_dev; 661 struct blk_integrity *bi; 662 struct bio_integrity_payload *bip; 663 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 664 int rc; 665 size_t resid, len; 666 667 bi = bdev_get_integrity(ib_dev->ibd_bd); 668 if (!bi) { 669 pr_err("Unable to locate bio_integrity\n"); 670 return -ENODEV; 671 } 672 673 bip = bio_integrity_alloc(bio, GFP_NOIO, bio_max_segs(cmd->t_prot_nents)); 674 if (IS_ERR(bip)) { 675 pr_err("Unable to allocate bio_integrity_payload\n"); 676 return PTR_ERR(bip); 677 } 678 679 bip->bip_iter.bi_size = bio_integrity_bytes(bi, bio_sectors(bio)); 680 /* virtual start sector must be in integrity interval units */ 681 bip_set_seed(bip, bio->bi_iter.bi_sector >> 682 (bi->interval_exp - SECTOR_SHIFT)); 683 684 pr_debug("IBLOCK BIP Size: %u Sector: %llu\n", bip->bip_iter.bi_size, 685 (unsigned long long)bip->bip_iter.bi_sector); 686 687 resid = bip->bip_iter.bi_size; 688 while (resid > 0 && sg_miter_next(miter)) { 689 690 len = min_t(size_t, miter->length, resid); 691 rc = bio_integrity_add_page(bio, miter->page, len, 692 offset_in_page(miter->addr)); 693 if (rc != len) { 694 pr_err("bio_integrity_add_page() failed; %d\n", rc); 695 sg_miter_stop(miter); 696 return -ENOMEM; 697 } 698 699 pr_debug("Added bio integrity page: %p length: %zu offset: %lu\n", 700 miter->page, len, offset_in_page(miter->addr)); 701 702 resid -= len; 703 if (len < miter->length) 704 miter->consumed -= miter->length - len; 705 } 706 sg_miter_stop(miter); 707 708 return 0; 709 } 710 711 static sense_reason_t 712 iblock_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents, 713 enum dma_data_direction data_direction) 714 { 715 struct se_device *dev = cmd->se_dev; 716 sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba); 717 struct iblock_req *ibr; 718 struct bio *bio; 719 struct bio_list list; 720 struct scatterlist *sg; 721 u32 sg_num = sgl_nents; 722 unsigned int opf; 723 unsigned bio_cnt; 724 int i, rc; 725 struct sg_mapping_iter prot_miter; 726 unsigned int miter_dir; 727 728 if (data_direction == DMA_TO_DEVICE) { 729 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 730 /* 731 * Force writethrough using REQ_FUA if a volatile write cache 732 * is not enabled, or if initiator set the Force Unit Access bit. 733 */ 734 opf = REQ_OP_WRITE; 735 miter_dir = SG_MITER_TO_SG; 736 if (bdev_fua(ib_dev->ibd_bd)) { 737 if (cmd->se_cmd_flags & SCF_FUA) 738 opf |= REQ_FUA; 739 else if (!bdev_write_cache(ib_dev->ibd_bd)) 740 opf |= REQ_FUA; 741 } 742 } else { 743 opf = REQ_OP_READ; 744 miter_dir = SG_MITER_FROM_SG; 745 } 746 747 ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL); 748 if (!ibr) 749 goto fail; 750 cmd->priv = ibr; 751 752 if (!sgl_nents) { 753 refcount_set(&ibr->pending, 1); 754 iblock_complete_cmd(cmd); 755 return 0; 756 } 757 758 bio = iblock_get_bio(cmd, block_lba, sgl_nents, opf); 759 if (!bio) 760 goto fail_free_ibr; 761 762 bio_list_init(&list); 763 bio_list_add(&list, bio); 764 765 refcount_set(&ibr->pending, 2); 766 bio_cnt = 1; 767 768 if (cmd->prot_type && dev->dev_attrib.pi_prot_type) 769 sg_miter_start(&prot_miter, cmd->t_prot_sg, cmd->t_prot_nents, 770 miter_dir); 771 772 for_each_sg(sgl, sg, sgl_nents, i) { 773 /* 774 * XXX: if the length the device accepts is shorter than the 775 * length of the S/G list entry this will cause and 776 * endless loop. Better hope no driver uses huge pages. 777 */ 778 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset) 779 != sg->length) { 780 if (cmd->prot_type && dev->dev_attrib.pi_prot_type) { 781 rc = iblock_alloc_bip(cmd, bio, &prot_miter); 782 if (rc) 783 goto fail_put_bios; 784 } 785 786 if (bio_cnt >= IBLOCK_MAX_BIO_PER_TASK) { 787 iblock_submit_bios(&list); 788 bio_cnt = 0; 789 } 790 791 bio = iblock_get_bio(cmd, block_lba, sg_num, opf); 792 if (!bio) 793 goto fail_put_bios; 794 795 refcount_inc(&ibr->pending); 796 bio_list_add(&list, bio); 797 bio_cnt++; 798 } 799 800 /* Always in 512 byte units for Linux/Block */ 801 block_lba += sg->length >> SECTOR_SHIFT; 802 sg_num--; 803 } 804 805 if (cmd->prot_type && dev->dev_attrib.pi_prot_type) { 806 rc = iblock_alloc_bip(cmd, bio, &prot_miter); 807 if (rc) 808 goto fail_put_bios; 809 } 810 811 iblock_submit_bios(&list); 812 iblock_complete_cmd(cmd); 813 return 0; 814 815 fail_put_bios: 816 while ((bio = bio_list_pop(&list))) 817 bio_put(bio); 818 fail_free_ibr: 819 kfree(ibr); 820 fail: 821 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 822 } 823 824 static sector_t iblock_get_blocks(struct se_device *dev) 825 { 826 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 827 struct block_device *bd = ib_dev->ibd_bd; 828 struct request_queue *q = bdev_get_queue(bd); 829 830 return iblock_emulate_read_cap_with_block_size(dev, bd, q); 831 } 832 833 static sector_t iblock_get_alignment_offset_lbas(struct se_device *dev) 834 { 835 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 836 struct block_device *bd = ib_dev->ibd_bd; 837 int ret; 838 839 ret = bdev_alignment_offset(bd); 840 if (ret == -1) 841 return 0; 842 843 /* convert offset-bytes to offset-lbas */ 844 return ret / bdev_logical_block_size(bd); 845 } 846 847 static unsigned int iblock_get_lbppbe(struct se_device *dev) 848 { 849 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 850 struct block_device *bd = ib_dev->ibd_bd; 851 unsigned int logs_per_phys = 852 bdev_physical_block_size(bd) / bdev_logical_block_size(bd); 853 854 return ilog2(logs_per_phys); 855 } 856 857 static unsigned int iblock_get_io_min(struct se_device *dev) 858 { 859 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 860 struct block_device *bd = ib_dev->ibd_bd; 861 862 return bdev_io_min(bd); 863 } 864 865 static unsigned int iblock_get_io_opt(struct se_device *dev) 866 { 867 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 868 struct block_device *bd = ib_dev->ibd_bd; 869 870 return bdev_io_opt(bd); 871 } 872 873 static struct sbc_ops iblock_sbc_ops = { 874 .execute_rw = iblock_execute_rw, 875 .execute_sync_cache = iblock_execute_sync_cache, 876 .execute_write_same = iblock_execute_write_same, 877 .execute_unmap = iblock_execute_unmap, 878 }; 879 880 static sense_reason_t 881 iblock_parse_cdb(struct se_cmd *cmd) 882 { 883 return sbc_parse_cdb(cmd, &iblock_sbc_ops); 884 } 885 886 static bool iblock_get_write_cache(struct se_device *dev) 887 { 888 return bdev_write_cache(IBLOCK_DEV(dev)->ibd_bd); 889 } 890 891 static const struct target_backend_ops iblock_ops = { 892 .name = "iblock", 893 .inquiry_prod = "IBLOCK", 894 .inquiry_rev = IBLOCK_VERSION, 895 .owner = THIS_MODULE, 896 .attach_hba = iblock_attach_hba, 897 .detach_hba = iblock_detach_hba, 898 .alloc_device = iblock_alloc_device, 899 .configure_device = iblock_configure_device, 900 .destroy_device = iblock_destroy_device, 901 .free_device = iblock_free_device, 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); 933