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/slab.h> 20 #include <linux/spinlock.h> 21 #include <linux/bio.h> 22 #include <linux/genhd.h> 23 #include <linux/file.h> 24 #include <linux/module.h> 25 #include <scsi/scsi_proto.h> 26 #include <asm/unaligned.h> 27 28 #include <target/target_core_base.h> 29 #include <target/target_core_backend.h> 30 31 #include "target_core_iblock.h" 32 33 #define IBLOCK_MAX_BIO_PER_TASK 32 /* max # of bios to submit at a time */ 34 #define IBLOCK_BIO_POOL_SIZE 128 35 36 static inline struct iblock_dev *IBLOCK_DEV(struct se_device *dev) 37 { 38 return container_of(dev, struct iblock_dev, dev); 39 } 40 41 42 static int iblock_attach_hba(struct se_hba *hba, u32 host_id) 43 { 44 pr_debug("CORE_HBA[%d] - TCM iBlock HBA Driver %s on" 45 " Generic Target Core Stack %s\n", hba->hba_id, 46 IBLOCK_VERSION, TARGET_CORE_VERSION); 47 return 0; 48 } 49 50 static void iblock_detach_hba(struct se_hba *hba) 51 { 52 } 53 54 static struct se_device *iblock_alloc_device(struct se_hba *hba, const char *name) 55 { 56 struct iblock_dev *ib_dev = NULL; 57 58 ib_dev = kzalloc(sizeof(struct iblock_dev), GFP_KERNEL); 59 if (!ib_dev) { 60 pr_err("Unable to allocate struct iblock_dev\n"); 61 return NULL; 62 } 63 64 pr_debug( "IBLOCK: Allocated ib_dev for %s\n", name); 65 66 return &ib_dev->dev; 67 } 68 69 static int iblock_configure_device(struct se_device *dev) 70 { 71 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 72 struct request_queue *q; 73 struct block_device *bd = NULL; 74 struct blk_integrity *bi; 75 fmode_t mode; 76 unsigned int max_write_zeroes_sectors; 77 int ret = -ENOMEM; 78 79 if (!(ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)) { 80 pr_err("Missing udev_path= parameters for IBLOCK\n"); 81 return -EINVAL; 82 } 83 84 ret = bioset_init(&ib_dev->ibd_bio_set, IBLOCK_BIO_POOL_SIZE, 0, BIOSET_NEED_BVECS); 85 if (ret) { 86 pr_err("IBLOCK: Unable to create bioset\n"); 87 goto out; 88 } 89 90 pr_debug( "IBLOCK: Claiming struct block_device: %s\n", 91 ib_dev->ibd_udev_path); 92 93 mode = FMODE_READ|FMODE_EXCL; 94 if (!ib_dev->ibd_readonly) 95 mode |= FMODE_WRITE; 96 else 97 dev->dev_flags |= DF_READ_ONLY; 98 99 bd = blkdev_get_by_path(ib_dev->ibd_udev_path, mode, ib_dev); 100 if (IS_ERR(bd)) { 101 ret = PTR_ERR(bd); 102 goto out_free_bioset; 103 } 104 ib_dev->ibd_bd = bd; 105 106 q = bdev_get_queue(bd); 107 108 dev->dev_attrib.hw_block_size = bdev_logical_block_size(bd); 109 dev->dev_attrib.hw_max_sectors = queue_max_hw_sectors(q); 110 dev->dev_attrib.hw_queue_depth = q->nr_requests; 111 112 if (target_configure_unmap_from_queue(&dev->dev_attrib, q)) 113 pr_debug("IBLOCK: BLOCK Discard support available," 114 " disabled by default\n"); 115 116 /* 117 * Enable write same emulation for IBLOCK and use 0xFFFF as 118 * the smaller WRITE_SAME(10) only has a two-byte block count. 119 */ 120 max_write_zeroes_sectors = bdev_write_zeroes_sectors(bd); 121 if (max_write_zeroes_sectors) 122 dev->dev_attrib.max_write_same_len = max_write_zeroes_sectors; 123 else 124 dev->dev_attrib.max_write_same_len = 0xFFFF; 125 126 if (blk_queue_nonrot(q)) 127 dev->dev_attrib.is_nonrot = 1; 128 129 bi = bdev_get_integrity(bd); 130 if (bi) { 131 struct bio_set *bs = &ib_dev->ibd_bio_set; 132 133 if (!strcmp(bi->profile->name, "T10-DIF-TYPE3-IP") || 134 !strcmp(bi->profile->name, "T10-DIF-TYPE1-IP")) { 135 pr_err("IBLOCK export of blk_integrity: %s not" 136 " supported\n", bi->profile->name); 137 ret = -ENOSYS; 138 goto out_blkdev_put; 139 } 140 141 if (!strcmp(bi->profile->name, "T10-DIF-TYPE3-CRC")) { 142 dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE3_PROT; 143 } else if (!strcmp(bi->profile->name, "T10-DIF-TYPE1-CRC")) { 144 dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE1_PROT; 145 } 146 147 if (dev->dev_attrib.pi_prot_type) { 148 if (bioset_integrity_create(bs, IBLOCK_BIO_POOL_SIZE) < 0) { 149 pr_err("Unable to allocate bioset for PI\n"); 150 ret = -ENOMEM; 151 goto out_blkdev_put; 152 } 153 pr_debug("IBLOCK setup BIP bs->bio_integrity_pool: %p\n", 154 &bs->bio_integrity_pool); 155 } 156 dev->dev_attrib.hw_pi_prot_type = dev->dev_attrib.pi_prot_type; 157 } 158 159 return 0; 160 161 out_blkdev_put: 162 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL); 163 out_free_bioset: 164 bioset_exit(&ib_dev->ibd_bio_set); 165 out: 166 return ret; 167 } 168 169 static void iblock_dev_call_rcu(struct rcu_head *p) 170 { 171 struct se_device *dev = container_of(p, struct se_device, rcu_head); 172 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 173 174 kfree(ib_dev); 175 } 176 177 static void iblock_free_device(struct se_device *dev) 178 { 179 call_rcu(&dev->rcu_head, iblock_dev_call_rcu); 180 } 181 182 static void iblock_destroy_device(struct se_device *dev) 183 { 184 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 185 186 if (ib_dev->ibd_bd != NULL) 187 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL); 188 bioset_exit(&ib_dev->ibd_bio_set); 189 } 190 191 static unsigned long long iblock_emulate_read_cap_with_block_size( 192 struct se_device *dev, 193 struct block_device *bd, 194 struct request_queue *q) 195 { 196 unsigned long long blocks_long = (div_u64(i_size_read(bd->bd_inode), 197 bdev_logical_block_size(bd)) - 1); 198 u32 block_size = bdev_logical_block_size(bd); 199 200 if (block_size == dev->dev_attrib.block_size) 201 return blocks_long; 202 203 switch (block_size) { 204 case 4096: 205 switch (dev->dev_attrib.block_size) { 206 case 2048: 207 blocks_long <<= 1; 208 break; 209 case 1024: 210 blocks_long <<= 2; 211 break; 212 case 512: 213 blocks_long <<= 3; 214 break; 215 default: 216 break; 217 } 218 break; 219 case 2048: 220 switch (dev->dev_attrib.block_size) { 221 case 4096: 222 blocks_long >>= 1; 223 break; 224 case 1024: 225 blocks_long <<= 1; 226 break; 227 case 512: 228 blocks_long <<= 2; 229 break; 230 default: 231 break; 232 } 233 break; 234 case 1024: 235 switch (dev->dev_attrib.block_size) { 236 case 4096: 237 blocks_long >>= 2; 238 break; 239 case 2048: 240 blocks_long >>= 1; 241 break; 242 case 512: 243 blocks_long <<= 1; 244 break; 245 default: 246 break; 247 } 248 break; 249 case 512: 250 switch (dev->dev_attrib.block_size) { 251 case 4096: 252 blocks_long >>= 3; 253 break; 254 case 2048: 255 blocks_long >>= 2; 256 break; 257 case 1024: 258 blocks_long >>= 1; 259 break; 260 default: 261 break; 262 } 263 break; 264 default: 265 break; 266 } 267 268 return blocks_long; 269 } 270 271 static void iblock_complete_cmd(struct se_cmd *cmd) 272 { 273 struct iblock_req *ibr = cmd->priv; 274 u8 status; 275 276 if (!refcount_dec_and_test(&ibr->pending)) 277 return; 278 279 if (atomic_read(&ibr->ib_bio_err_cnt)) 280 status = SAM_STAT_CHECK_CONDITION; 281 else 282 status = SAM_STAT_GOOD; 283 284 target_complete_cmd(cmd, status); 285 kfree(ibr); 286 } 287 288 static void iblock_bio_done(struct bio *bio) 289 { 290 struct se_cmd *cmd = bio->bi_private; 291 struct iblock_req *ibr = cmd->priv; 292 293 if (bio->bi_status) { 294 pr_err("bio error: %p, err: %d\n", bio, bio->bi_status); 295 /* 296 * Bump the ib_bio_err_cnt and release bio. 297 */ 298 atomic_inc(&ibr->ib_bio_err_cnt); 299 smp_mb__after_atomic(); 300 } 301 302 bio_put(bio); 303 304 iblock_complete_cmd(cmd); 305 } 306 307 static struct bio * 308 iblock_get_bio(struct se_cmd *cmd, sector_t lba, u32 sg_num, int op, 309 int op_flags) 310 { 311 struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev); 312 struct bio *bio; 313 314 /* 315 * Only allocate as many vector entries as the bio code allows us to, 316 * we'll loop later on until we have handled the whole request. 317 */ 318 if (sg_num > BIO_MAX_PAGES) 319 sg_num = BIO_MAX_PAGES; 320 321 bio = bio_alloc_bioset(GFP_NOIO, sg_num, &ib_dev->ibd_bio_set); 322 if (!bio) { 323 pr_err("Unable to allocate memory for bio\n"); 324 return NULL; 325 } 326 327 bio_set_dev(bio, ib_dev->ibd_bd); 328 bio->bi_private = cmd; 329 bio->bi_end_io = &iblock_bio_done; 330 bio->bi_iter.bi_sector = lba; 331 bio_set_op_attrs(bio, op, op_flags); 332 333 return bio; 334 } 335 336 static void iblock_submit_bios(struct bio_list *list) 337 { 338 struct blk_plug plug; 339 struct bio *bio; 340 341 blk_start_plug(&plug); 342 while ((bio = bio_list_pop(list))) 343 submit_bio(bio); 344 blk_finish_plug(&plug); 345 } 346 347 static void iblock_end_io_flush(struct bio *bio) 348 { 349 struct se_cmd *cmd = bio->bi_private; 350 351 if (bio->bi_status) 352 pr_err("IBLOCK: cache flush failed: %d\n", bio->bi_status); 353 354 if (cmd) { 355 if (bio->bi_status) 356 target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION); 357 else 358 target_complete_cmd(cmd, SAM_STAT_GOOD); 359 } 360 361 bio_put(bio); 362 } 363 364 /* 365 * Implement SYCHRONIZE CACHE. Note that we can't handle lba ranges and must 366 * always flush the whole cache. 367 */ 368 static sense_reason_t 369 iblock_execute_sync_cache(struct se_cmd *cmd) 370 { 371 struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev); 372 int immed = (cmd->t_task_cdb[1] & 0x2); 373 struct bio *bio; 374 375 /* 376 * If the Immediate bit is set, queue up the GOOD response 377 * for this SYNCHRONIZE_CACHE op. 378 */ 379 if (immed) 380 target_complete_cmd(cmd, SAM_STAT_GOOD); 381 382 bio = bio_alloc(GFP_KERNEL, 0); 383 bio->bi_end_io = iblock_end_io_flush; 384 bio_set_dev(bio, ib_dev->ibd_bd); 385 bio->bi_opf = REQ_OP_WRITE | REQ_PREFLUSH; 386 if (!immed) 387 bio->bi_private = cmd; 388 submit_bio(bio); 389 return 0; 390 } 391 392 static sense_reason_t 393 iblock_execute_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb) 394 { 395 struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd; 396 struct se_device *dev = cmd->se_dev; 397 int ret; 398 399 ret = blkdev_issue_discard(bdev, 400 target_to_linux_sector(dev, lba), 401 target_to_linux_sector(dev, nolb), 402 GFP_KERNEL, 0); 403 if (ret < 0) { 404 pr_err("blkdev_issue_discard() failed: %d\n", ret); 405 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 406 } 407 408 return 0; 409 } 410 411 static sense_reason_t 412 iblock_execute_zero_out(struct block_device *bdev, struct se_cmd *cmd) 413 { 414 struct se_device *dev = cmd->se_dev; 415 struct scatterlist *sg = &cmd->t_data_sg[0]; 416 unsigned char *buf, *not_zero; 417 int ret; 418 419 buf = kmap(sg_page(sg)) + sg->offset; 420 if (!buf) 421 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 422 /* 423 * Fall back to block_execute_write_same() slow-path if 424 * incoming WRITE_SAME payload does not contain zeros. 425 */ 426 not_zero = memchr_inv(buf, 0x00, cmd->data_length); 427 kunmap(sg_page(sg)); 428 429 if (not_zero) 430 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 431 432 ret = blkdev_issue_zeroout(bdev, 433 target_to_linux_sector(dev, cmd->t_task_lba), 434 target_to_linux_sector(dev, 435 sbc_get_write_same_sectors(cmd)), 436 GFP_KERNEL, BLKDEV_ZERO_NOUNMAP); 437 if (ret) 438 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 439 440 target_complete_cmd(cmd, GOOD); 441 return 0; 442 } 443 444 static sense_reason_t 445 iblock_execute_write_same(struct se_cmd *cmd) 446 { 447 struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd; 448 struct iblock_req *ibr; 449 struct scatterlist *sg; 450 struct bio *bio; 451 struct bio_list list; 452 struct se_device *dev = cmd->se_dev; 453 sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba); 454 sector_t sectors = target_to_linux_sector(dev, 455 sbc_get_write_same_sectors(cmd)); 456 457 if (cmd->prot_op) { 458 pr_err("WRITE_SAME: Protection information with IBLOCK" 459 " backends not supported\n"); 460 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 461 } 462 sg = &cmd->t_data_sg[0]; 463 464 if (cmd->t_data_nents > 1 || 465 sg->length != cmd->se_dev->dev_attrib.block_size) { 466 pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u" 467 " block_size: %u\n", cmd->t_data_nents, sg->length, 468 cmd->se_dev->dev_attrib.block_size); 469 return TCM_INVALID_CDB_FIELD; 470 } 471 472 if (bdev_write_zeroes_sectors(bdev)) { 473 if (!iblock_execute_zero_out(bdev, cmd)) 474 return 0; 475 } 476 477 ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL); 478 if (!ibr) 479 goto fail; 480 cmd->priv = ibr; 481 482 bio = iblock_get_bio(cmd, block_lba, 1, REQ_OP_WRITE, 0); 483 if (!bio) 484 goto fail_free_ibr; 485 486 bio_list_init(&list); 487 bio_list_add(&list, bio); 488 489 refcount_set(&ibr->pending, 1); 490 491 while (sectors) { 492 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset) 493 != sg->length) { 494 495 bio = iblock_get_bio(cmd, block_lba, 1, REQ_OP_WRITE, 496 0); 497 if (!bio) 498 goto fail_put_bios; 499 500 refcount_inc(&ibr->pending); 501 bio_list_add(&list, bio); 502 } 503 504 /* Always in 512 byte units for Linux/Block */ 505 block_lba += sg->length >> SECTOR_SHIFT; 506 sectors -= sg->length >> SECTOR_SHIFT; 507 } 508 509 iblock_submit_bios(&list); 510 return 0; 511 512 fail_put_bios: 513 while ((bio = bio_list_pop(&list))) 514 bio_put(bio); 515 fail_free_ibr: 516 kfree(ibr); 517 fail: 518 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 519 } 520 521 enum { 522 Opt_udev_path, Opt_readonly, Opt_force, Opt_err 523 }; 524 525 static match_table_t tokens = { 526 {Opt_udev_path, "udev_path=%s"}, 527 {Opt_readonly, "readonly=%d"}, 528 {Opt_force, "force=%d"}, 529 {Opt_err, NULL} 530 }; 531 532 static ssize_t iblock_set_configfs_dev_params(struct se_device *dev, 533 const char *page, ssize_t count) 534 { 535 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 536 char *orig, *ptr, *arg_p, *opts; 537 substring_t args[MAX_OPT_ARGS]; 538 int ret = 0, token; 539 unsigned long tmp_readonly; 540 541 opts = kstrdup(page, GFP_KERNEL); 542 if (!opts) 543 return -ENOMEM; 544 545 orig = opts; 546 547 while ((ptr = strsep(&opts, ",\n")) != NULL) { 548 if (!*ptr) 549 continue; 550 551 token = match_token(ptr, tokens, args); 552 switch (token) { 553 case Opt_udev_path: 554 if (ib_dev->ibd_bd) { 555 pr_err("Unable to set udev_path= while" 556 " ib_dev->ibd_bd exists\n"); 557 ret = -EEXIST; 558 goto out; 559 } 560 if (match_strlcpy(ib_dev->ibd_udev_path, &args[0], 561 SE_UDEV_PATH_LEN) == 0) { 562 ret = -EINVAL; 563 break; 564 } 565 pr_debug("IBLOCK: Referencing UDEV path: %s\n", 566 ib_dev->ibd_udev_path); 567 ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH; 568 break; 569 case Opt_readonly: 570 arg_p = match_strdup(&args[0]); 571 if (!arg_p) { 572 ret = -ENOMEM; 573 break; 574 } 575 ret = kstrtoul(arg_p, 0, &tmp_readonly); 576 kfree(arg_p); 577 if (ret < 0) { 578 pr_err("kstrtoul() failed for" 579 " readonly=\n"); 580 goto out; 581 } 582 ib_dev->ibd_readonly = tmp_readonly; 583 pr_debug("IBLOCK: readonly: %d\n", ib_dev->ibd_readonly); 584 break; 585 case Opt_force: 586 break; 587 default: 588 break; 589 } 590 } 591 592 out: 593 kfree(orig); 594 return (!ret) ? count : ret; 595 } 596 597 static ssize_t iblock_show_configfs_dev_params(struct se_device *dev, char *b) 598 { 599 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 600 struct block_device *bd = ib_dev->ibd_bd; 601 char buf[BDEVNAME_SIZE]; 602 ssize_t bl = 0; 603 604 if (bd) 605 bl += sprintf(b + bl, "iBlock device: %s", 606 bdevname(bd, buf)); 607 if (ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH) 608 bl += sprintf(b + bl, " UDEV PATH: %s", 609 ib_dev->ibd_udev_path); 610 bl += sprintf(b + bl, " readonly: %d\n", ib_dev->ibd_readonly); 611 612 bl += sprintf(b + bl, " "); 613 if (bd) { 614 bl += sprintf(b + bl, "Major: %d Minor: %d %s\n", 615 MAJOR(bd->bd_dev), MINOR(bd->bd_dev), 616 "CLAIMED: IBLOCK"); 617 } else { 618 bl += sprintf(b + bl, "Major: 0 Minor: 0\n"); 619 } 620 621 return bl; 622 } 623 624 static int 625 iblock_alloc_bip(struct se_cmd *cmd, struct bio *bio, 626 struct sg_mapping_iter *miter) 627 { 628 struct se_device *dev = cmd->se_dev; 629 struct blk_integrity *bi; 630 struct bio_integrity_payload *bip; 631 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 632 int rc; 633 size_t resid, len; 634 635 bi = bdev_get_integrity(ib_dev->ibd_bd); 636 if (!bi) { 637 pr_err("Unable to locate bio_integrity\n"); 638 return -ENODEV; 639 } 640 641 bip = bio_integrity_alloc(bio, GFP_NOIO, 642 min_t(unsigned int, cmd->t_prot_nents, BIO_MAX_PAGES)); 643 if (IS_ERR(bip)) { 644 pr_err("Unable to allocate bio_integrity_payload\n"); 645 return PTR_ERR(bip); 646 } 647 648 bip->bip_iter.bi_size = bio_integrity_bytes(bi, bio_sectors(bio)); 649 /* virtual start sector must be in integrity interval units */ 650 bip_set_seed(bip, bio->bi_iter.bi_sector >> 651 (bi->interval_exp - SECTOR_SHIFT)); 652 653 pr_debug("IBLOCK BIP Size: %u Sector: %llu\n", bip->bip_iter.bi_size, 654 (unsigned long long)bip->bip_iter.bi_sector); 655 656 resid = bip->bip_iter.bi_size; 657 while (resid > 0 && sg_miter_next(miter)) { 658 659 len = min_t(size_t, miter->length, resid); 660 rc = bio_integrity_add_page(bio, miter->page, len, 661 offset_in_page(miter->addr)); 662 if (rc != len) { 663 pr_err("bio_integrity_add_page() failed; %d\n", rc); 664 sg_miter_stop(miter); 665 return -ENOMEM; 666 } 667 668 pr_debug("Added bio integrity page: %p length: %zu offset: %lu\n", 669 miter->page, len, offset_in_page(miter->addr)); 670 671 resid -= len; 672 if (len < miter->length) 673 miter->consumed -= miter->length - len; 674 } 675 sg_miter_stop(miter); 676 677 return 0; 678 } 679 680 static sense_reason_t 681 iblock_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents, 682 enum dma_data_direction data_direction) 683 { 684 struct se_device *dev = cmd->se_dev; 685 sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba); 686 struct iblock_req *ibr; 687 struct bio *bio; 688 struct bio_list list; 689 struct scatterlist *sg; 690 u32 sg_num = sgl_nents; 691 unsigned bio_cnt; 692 int i, rc, op, op_flags = 0; 693 struct sg_mapping_iter prot_miter; 694 695 if (data_direction == DMA_TO_DEVICE) { 696 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 697 struct request_queue *q = bdev_get_queue(ib_dev->ibd_bd); 698 /* 699 * Force writethrough using REQ_FUA if a volatile write cache 700 * is not enabled, or if initiator set the Force Unit Access bit. 701 */ 702 op = REQ_OP_WRITE; 703 if (test_bit(QUEUE_FLAG_FUA, &q->queue_flags)) { 704 if (cmd->se_cmd_flags & SCF_FUA) 705 op_flags = REQ_FUA; 706 else if (!test_bit(QUEUE_FLAG_WC, &q->queue_flags)) 707 op_flags = REQ_FUA; 708 } 709 } else { 710 op = REQ_OP_READ; 711 } 712 713 ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL); 714 if (!ibr) 715 goto fail; 716 cmd->priv = ibr; 717 718 if (!sgl_nents) { 719 refcount_set(&ibr->pending, 1); 720 iblock_complete_cmd(cmd); 721 return 0; 722 } 723 724 bio = iblock_get_bio(cmd, block_lba, sgl_nents, op, op_flags); 725 if (!bio) 726 goto fail_free_ibr; 727 728 bio_list_init(&list); 729 bio_list_add(&list, bio); 730 731 refcount_set(&ibr->pending, 2); 732 bio_cnt = 1; 733 734 if (cmd->prot_type && dev->dev_attrib.pi_prot_type) 735 sg_miter_start(&prot_miter, cmd->t_prot_sg, cmd->t_prot_nents, 736 op == REQ_OP_READ ? SG_MITER_FROM_SG : 737 SG_MITER_TO_SG); 738 739 for_each_sg(sgl, sg, sgl_nents, i) { 740 /* 741 * XXX: if the length the device accepts is shorter than the 742 * length of the S/G list entry this will cause and 743 * endless loop. Better hope no driver uses huge pages. 744 */ 745 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset) 746 != sg->length) { 747 if (cmd->prot_type && dev->dev_attrib.pi_prot_type) { 748 rc = iblock_alloc_bip(cmd, bio, &prot_miter); 749 if (rc) 750 goto fail_put_bios; 751 } 752 753 if (bio_cnt >= IBLOCK_MAX_BIO_PER_TASK) { 754 iblock_submit_bios(&list); 755 bio_cnt = 0; 756 } 757 758 bio = iblock_get_bio(cmd, block_lba, sg_num, op, 759 op_flags); 760 if (!bio) 761 goto fail_put_bios; 762 763 refcount_inc(&ibr->pending); 764 bio_list_add(&list, bio); 765 bio_cnt++; 766 } 767 768 /* Always in 512 byte units for Linux/Block */ 769 block_lba += sg->length >> SECTOR_SHIFT; 770 sg_num--; 771 } 772 773 if (cmd->prot_type && dev->dev_attrib.pi_prot_type) { 774 rc = iblock_alloc_bip(cmd, bio, &prot_miter); 775 if (rc) 776 goto fail_put_bios; 777 } 778 779 iblock_submit_bios(&list); 780 iblock_complete_cmd(cmd); 781 return 0; 782 783 fail_put_bios: 784 while ((bio = bio_list_pop(&list))) 785 bio_put(bio); 786 fail_free_ibr: 787 kfree(ibr); 788 fail: 789 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 790 } 791 792 static sector_t iblock_get_blocks(struct se_device *dev) 793 { 794 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 795 struct block_device *bd = ib_dev->ibd_bd; 796 struct request_queue *q = bdev_get_queue(bd); 797 798 return iblock_emulate_read_cap_with_block_size(dev, bd, q); 799 } 800 801 static sector_t iblock_get_alignment_offset_lbas(struct se_device *dev) 802 { 803 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 804 struct block_device *bd = ib_dev->ibd_bd; 805 int ret; 806 807 ret = bdev_alignment_offset(bd); 808 if (ret == -1) 809 return 0; 810 811 /* convert offset-bytes to offset-lbas */ 812 return ret / bdev_logical_block_size(bd); 813 } 814 815 static unsigned int iblock_get_lbppbe(struct se_device *dev) 816 { 817 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 818 struct block_device *bd = ib_dev->ibd_bd; 819 int logs_per_phys = bdev_physical_block_size(bd) / bdev_logical_block_size(bd); 820 821 return ilog2(logs_per_phys); 822 } 823 824 static unsigned int iblock_get_io_min(struct se_device *dev) 825 { 826 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 827 struct block_device *bd = ib_dev->ibd_bd; 828 829 return bdev_io_min(bd); 830 } 831 832 static unsigned int iblock_get_io_opt(struct se_device *dev) 833 { 834 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 835 struct block_device *bd = ib_dev->ibd_bd; 836 837 return bdev_io_opt(bd); 838 } 839 840 static struct sbc_ops iblock_sbc_ops = { 841 .execute_rw = iblock_execute_rw, 842 .execute_sync_cache = iblock_execute_sync_cache, 843 .execute_write_same = iblock_execute_write_same, 844 .execute_unmap = iblock_execute_unmap, 845 }; 846 847 static sense_reason_t 848 iblock_parse_cdb(struct se_cmd *cmd) 849 { 850 return sbc_parse_cdb(cmd, &iblock_sbc_ops); 851 } 852 853 static bool iblock_get_write_cache(struct se_device *dev) 854 { 855 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 856 struct block_device *bd = ib_dev->ibd_bd; 857 struct request_queue *q = bdev_get_queue(bd); 858 859 return test_bit(QUEUE_FLAG_WC, &q->queue_flags); 860 } 861 862 static const struct target_backend_ops iblock_ops = { 863 .name = "iblock", 864 .inquiry_prod = "IBLOCK", 865 .inquiry_rev = IBLOCK_VERSION, 866 .owner = THIS_MODULE, 867 .attach_hba = iblock_attach_hba, 868 .detach_hba = iblock_detach_hba, 869 .alloc_device = iblock_alloc_device, 870 .configure_device = iblock_configure_device, 871 .destroy_device = iblock_destroy_device, 872 .free_device = iblock_free_device, 873 .parse_cdb = iblock_parse_cdb, 874 .set_configfs_dev_params = iblock_set_configfs_dev_params, 875 .show_configfs_dev_params = iblock_show_configfs_dev_params, 876 .get_device_type = sbc_get_device_type, 877 .get_blocks = iblock_get_blocks, 878 .get_alignment_offset_lbas = iblock_get_alignment_offset_lbas, 879 .get_lbppbe = iblock_get_lbppbe, 880 .get_io_min = iblock_get_io_min, 881 .get_io_opt = iblock_get_io_opt, 882 .get_write_cache = iblock_get_write_cache, 883 .tb_dev_attrib_attrs = sbc_attrib_attrs, 884 }; 885 886 static int __init iblock_module_init(void) 887 { 888 return transport_backend_register(&iblock_ops); 889 } 890 891 static void __exit iblock_module_exit(void) 892 { 893 target_backend_unregister(&iblock_ops); 894 } 895 896 MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin"); 897 MODULE_AUTHOR("nab@Linux-iSCSI.org"); 898 MODULE_LICENSE("GPL"); 899 900 module_init(iblock_module_init); 901 module_exit(iblock_module_exit); 902