1 /******************************************************************************* 2 * Filename: target_core_iblock.c 3 * 4 * This file contains the Storage Engine <-> Linux BlockIO transport 5 * specific functions. 6 * 7 * (c) Copyright 2003-2012 RisingTide Systems LLC. 8 * 9 * Nicholas A. Bellinger <nab@kernel.org> 10 * 11 * This program is free software; you can redistribute it and/or modify 12 * it under the terms of the GNU General Public License as published by 13 * the Free Software Foundation; either version 2 of the License, or 14 * (at your option) any later version. 15 * 16 * This program is distributed in the hope that it will be useful, 17 * but WITHOUT ANY WARRANTY; without even the implied warranty of 18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 19 * GNU General Public License for more details. 20 * 21 * You should have received a copy of the GNU General Public License 22 * along with this program; if not, write to the Free Software 23 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 24 * 25 ******************************************************************************/ 26 27 #include <linux/string.h> 28 #include <linux/parser.h> 29 #include <linux/timer.h> 30 #include <linux/fs.h> 31 #include <linux/blkdev.h> 32 #include <linux/slab.h> 33 #include <linux/spinlock.h> 34 #include <linux/bio.h> 35 #include <linux/genhd.h> 36 #include <linux/file.h> 37 #include <linux/module.h> 38 #include <scsi/scsi.h> 39 #include <scsi/scsi_host.h> 40 #include <asm/unaligned.h> 41 42 #include <target/target_core_base.h> 43 #include <target/target_core_backend.h> 44 45 #include "target_core_iblock.h" 46 47 #define IBLOCK_MAX_BIO_PER_TASK 32 /* max # of bios to submit at a time */ 48 #define IBLOCK_BIO_POOL_SIZE 128 49 50 static inline struct iblock_dev *IBLOCK_DEV(struct se_device *dev) 51 { 52 return container_of(dev, struct iblock_dev, dev); 53 } 54 55 56 static struct se_subsystem_api iblock_template; 57 58 /* iblock_attach_hba(): (Part of se_subsystem_api_t template) 59 * 60 * 61 */ 62 static int iblock_attach_hba(struct se_hba *hba, u32 host_id) 63 { 64 pr_debug("CORE_HBA[%d] - TCM iBlock HBA Driver %s on" 65 " Generic Target Core Stack %s\n", hba->hba_id, 66 IBLOCK_VERSION, TARGET_CORE_MOD_VERSION); 67 return 0; 68 } 69 70 static void iblock_detach_hba(struct se_hba *hba) 71 { 72 } 73 74 static struct se_device *iblock_alloc_device(struct se_hba *hba, const char *name) 75 { 76 struct iblock_dev *ib_dev = NULL; 77 78 ib_dev = kzalloc(sizeof(struct iblock_dev), GFP_KERNEL); 79 if (!ib_dev) { 80 pr_err("Unable to allocate struct iblock_dev\n"); 81 return NULL; 82 } 83 84 pr_debug( "IBLOCK: Allocated ib_dev for %s\n", name); 85 86 return &ib_dev->dev; 87 } 88 89 static int iblock_configure_device(struct se_device *dev) 90 { 91 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 92 struct request_queue *q; 93 struct block_device *bd = NULL; 94 fmode_t mode; 95 int ret = -ENOMEM; 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 ib_dev->ibd_bio_set = bioset_create(IBLOCK_BIO_POOL_SIZE, 0); 103 if (!ib_dev->ibd_bio_set) { 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; 114 115 bd = blkdev_get_by_path(ib_dev->ibd_udev_path, mode, ib_dev); 116 if (IS_ERR(bd)) { 117 ret = PTR_ERR(bd); 118 goto out_free_bioset; 119 } 120 ib_dev->ibd_bd = bd; 121 122 q = bdev_get_queue(bd); 123 124 dev->dev_attrib.hw_block_size = bdev_logical_block_size(bd); 125 dev->dev_attrib.hw_max_sectors = UINT_MAX; 126 dev->dev_attrib.hw_queue_depth = q->nr_requests; 127 128 /* 129 * Check if the underlying struct block_device request_queue supports 130 * the QUEUE_FLAG_DISCARD bit for UNMAP/WRITE_SAME in SCSI + TRIM 131 * in ATA and we need to set TPE=1 132 */ 133 if (blk_queue_discard(q)) { 134 dev->dev_attrib.max_unmap_lba_count = 135 q->limits.max_discard_sectors; 136 137 /* 138 * Currently hardcoded to 1 in Linux/SCSI code.. 139 */ 140 dev->dev_attrib.max_unmap_block_desc_count = 1; 141 dev->dev_attrib.unmap_granularity = 142 q->limits.discard_granularity >> 9; 143 dev->dev_attrib.unmap_granularity_alignment = 144 q->limits.discard_alignment; 145 146 pr_debug("IBLOCK: BLOCK Discard support available," 147 " disabled by default\n"); 148 } 149 /* 150 * Enable write same emulation for IBLOCK and use 0xFFFF as 151 * the smaller WRITE_SAME(10) only has a two-byte block count. 152 */ 153 dev->dev_attrib.max_write_same_len = 0xFFFF; 154 155 if (blk_queue_nonrot(q)) 156 dev->dev_attrib.is_nonrot = 1; 157 158 return 0; 159 160 out_free_bioset: 161 bioset_free(ib_dev->ibd_bio_set); 162 ib_dev->ibd_bio_set = NULL; 163 out: 164 return ret; 165 } 166 167 static void iblock_free_device(struct se_device *dev) 168 { 169 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 170 171 if (ib_dev->ibd_bd != NULL) 172 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL); 173 if (ib_dev->ibd_bio_set != NULL) 174 bioset_free(ib_dev->ibd_bio_set); 175 kfree(ib_dev); 176 } 177 178 static unsigned long long iblock_emulate_read_cap_with_block_size( 179 struct se_device *dev, 180 struct block_device *bd, 181 struct request_queue *q) 182 { 183 unsigned long long blocks_long = (div_u64(i_size_read(bd->bd_inode), 184 bdev_logical_block_size(bd)) - 1); 185 u32 block_size = bdev_logical_block_size(bd); 186 187 if (block_size == dev->dev_attrib.block_size) 188 return blocks_long; 189 190 switch (block_size) { 191 case 4096: 192 switch (dev->dev_attrib.block_size) { 193 case 2048: 194 blocks_long <<= 1; 195 break; 196 case 1024: 197 blocks_long <<= 2; 198 break; 199 case 512: 200 blocks_long <<= 3; 201 default: 202 break; 203 } 204 break; 205 case 2048: 206 switch (dev->dev_attrib.block_size) { 207 case 4096: 208 blocks_long >>= 1; 209 break; 210 case 1024: 211 blocks_long <<= 1; 212 break; 213 case 512: 214 blocks_long <<= 2; 215 break; 216 default: 217 break; 218 } 219 break; 220 case 1024: 221 switch (dev->dev_attrib.block_size) { 222 case 4096: 223 blocks_long >>= 2; 224 break; 225 case 2048: 226 blocks_long >>= 1; 227 break; 228 case 512: 229 blocks_long <<= 1; 230 break; 231 default: 232 break; 233 } 234 break; 235 case 512: 236 switch (dev->dev_attrib.block_size) { 237 case 4096: 238 blocks_long >>= 3; 239 break; 240 case 2048: 241 blocks_long >>= 2; 242 break; 243 case 1024: 244 blocks_long >>= 1; 245 break; 246 default: 247 break; 248 } 249 break; 250 default: 251 break; 252 } 253 254 return blocks_long; 255 } 256 257 static void iblock_complete_cmd(struct se_cmd *cmd) 258 { 259 struct iblock_req *ibr = cmd->priv; 260 u8 status; 261 262 if (!atomic_dec_and_test(&ibr->pending)) 263 return; 264 265 if (atomic_read(&ibr->ib_bio_err_cnt)) 266 status = SAM_STAT_CHECK_CONDITION; 267 else 268 status = SAM_STAT_GOOD; 269 270 target_complete_cmd(cmd, status); 271 kfree(ibr); 272 } 273 274 static void iblock_bio_done(struct bio *bio, int err) 275 { 276 struct se_cmd *cmd = bio->bi_private; 277 struct iblock_req *ibr = cmd->priv; 278 279 /* 280 * Set -EIO if !BIO_UPTODATE and the passed is still err=0 281 */ 282 if (!test_bit(BIO_UPTODATE, &bio->bi_flags) && !err) 283 err = -EIO; 284 285 if (err != 0) { 286 pr_err("test_bit(BIO_UPTODATE) failed for bio: %p," 287 " err: %d\n", bio, err); 288 /* 289 * Bump the ib_bio_err_cnt and release bio. 290 */ 291 atomic_inc(&ibr->ib_bio_err_cnt); 292 smp_mb__after_atomic_inc(); 293 } 294 295 bio_put(bio); 296 297 iblock_complete_cmd(cmd); 298 } 299 300 static struct bio * 301 iblock_get_bio(struct se_cmd *cmd, sector_t lba, u32 sg_num) 302 { 303 struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev); 304 struct bio *bio; 305 306 /* 307 * Only allocate as many vector entries as the bio code allows us to, 308 * we'll loop later on until we have handled the whole request. 309 */ 310 if (sg_num > BIO_MAX_PAGES) 311 sg_num = BIO_MAX_PAGES; 312 313 bio = bio_alloc_bioset(GFP_NOIO, sg_num, ib_dev->ibd_bio_set); 314 if (!bio) { 315 pr_err("Unable to allocate memory for bio\n"); 316 return NULL; 317 } 318 319 bio->bi_bdev = ib_dev->ibd_bd; 320 bio->bi_private = cmd; 321 bio->bi_end_io = &iblock_bio_done; 322 bio->bi_sector = lba; 323 324 return bio; 325 } 326 327 static void iblock_submit_bios(struct bio_list *list, int rw) 328 { 329 struct blk_plug plug; 330 struct bio *bio; 331 332 blk_start_plug(&plug); 333 while ((bio = bio_list_pop(list))) 334 submit_bio(rw, bio); 335 blk_finish_plug(&plug); 336 } 337 338 static void iblock_end_io_flush(struct bio *bio, int err) 339 { 340 struct se_cmd *cmd = bio->bi_private; 341 342 if (err) 343 pr_err("IBLOCK: cache flush failed: %d\n", err); 344 345 if (cmd) { 346 if (err) 347 target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION); 348 else 349 target_complete_cmd(cmd, SAM_STAT_GOOD); 350 } 351 352 bio_put(bio); 353 } 354 355 /* 356 * Implement SYCHRONIZE CACHE. Note that we can't handle lba ranges and must 357 * always flush the whole cache. 358 */ 359 static sense_reason_t 360 iblock_execute_sync_cache(struct se_cmd *cmd) 361 { 362 struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev); 363 int immed = (cmd->t_task_cdb[1] & 0x2); 364 struct bio *bio; 365 366 /* 367 * If the Immediate bit is set, queue up the GOOD response 368 * for this SYNCHRONIZE_CACHE op. 369 */ 370 if (immed) 371 target_complete_cmd(cmd, SAM_STAT_GOOD); 372 373 bio = bio_alloc(GFP_KERNEL, 0); 374 bio->bi_end_io = iblock_end_io_flush; 375 bio->bi_bdev = ib_dev->ibd_bd; 376 if (!immed) 377 bio->bi_private = cmd; 378 submit_bio(WRITE_FLUSH, bio); 379 return 0; 380 } 381 382 static sense_reason_t 383 iblock_execute_unmap(struct se_cmd *cmd) 384 { 385 struct se_device *dev = cmd->se_dev; 386 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 387 unsigned char *buf, *ptr = NULL; 388 sector_t lba; 389 int size; 390 u32 range; 391 sense_reason_t ret = 0; 392 int dl, bd_dl, err; 393 394 /* We never set ANC_SUP */ 395 if (cmd->t_task_cdb[1]) 396 return TCM_INVALID_CDB_FIELD; 397 398 if (cmd->data_length == 0) { 399 target_complete_cmd(cmd, SAM_STAT_GOOD); 400 return 0; 401 } 402 403 if (cmd->data_length < 8) { 404 pr_warn("UNMAP parameter list length %u too small\n", 405 cmd->data_length); 406 return TCM_PARAMETER_LIST_LENGTH_ERROR; 407 } 408 409 buf = transport_kmap_data_sg(cmd); 410 if (!buf) 411 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 412 413 dl = get_unaligned_be16(&buf[0]); 414 bd_dl = get_unaligned_be16(&buf[2]); 415 416 size = cmd->data_length - 8; 417 if (bd_dl > size) 418 pr_warn("UNMAP parameter list length %u too small, ignoring bd_dl %u\n", 419 cmd->data_length, bd_dl); 420 else 421 size = bd_dl; 422 423 if (size / 16 > dev->dev_attrib.max_unmap_block_desc_count) { 424 ret = TCM_INVALID_PARAMETER_LIST; 425 goto err; 426 } 427 428 /* First UNMAP block descriptor starts at 8 byte offset */ 429 ptr = &buf[8]; 430 pr_debug("UNMAP: Sub: %s Using dl: %u bd_dl: %u size: %u" 431 " ptr: %p\n", dev->transport->name, dl, bd_dl, size, ptr); 432 433 while (size >= 16) { 434 lba = get_unaligned_be64(&ptr[0]); 435 range = get_unaligned_be32(&ptr[8]); 436 pr_debug("UNMAP: Using lba: %llu and range: %u\n", 437 (unsigned long long)lba, range); 438 439 if (range > dev->dev_attrib.max_unmap_lba_count) { 440 ret = TCM_INVALID_PARAMETER_LIST; 441 goto err; 442 } 443 444 if (lba + range > dev->transport->get_blocks(dev) + 1) { 445 ret = TCM_ADDRESS_OUT_OF_RANGE; 446 goto err; 447 } 448 449 err = blkdev_issue_discard(ib_dev->ibd_bd, lba, range, 450 GFP_KERNEL, 0); 451 if (err < 0) { 452 pr_err("blkdev_issue_discard() failed: %d\n", 453 err); 454 ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 455 goto err; 456 } 457 458 ptr += 16; 459 size -= 16; 460 } 461 462 err: 463 transport_kunmap_data_sg(cmd); 464 if (!ret) 465 target_complete_cmd(cmd, GOOD); 466 return ret; 467 } 468 469 static sense_reason_t 470 iblock_execute_write_same_unmap(struct se_cmd *cmd) 471 { 472 struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev); 473 int rc; 474 475 rc = blkdev_issue_discard(ib_dev->ibd_bd, cmd->t_task_lba, 476 sbc_get_write_same_sectors(cmd), GFP_KERNEL, 0); 477 if (rc < 0) { 478 pr_warn("blkdev_issue_discard() failed: %d\n", rc); 479 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 480 } 481 482 target_complete_cmd(cmd, GOOD); 483 return 0; 484 } 485 486 static sense_reason_t 487 iblock_execute_write_same(struct se_cmd *cmd) 488 { 489 struct iblock_req *ibr; 490 struct scatterlist *sg; 491 struct bio *bio; 492 struct bio_list list; 493 sector_t block_lba = cmd->t_task_lba; 494 sector_t sectors = sbc_get_write_same_sectors(cmd); 495 496 sg = &cmd->t_data_sg[0]; 497 498 if (cmd->t_data_nents > 1 || 499 sg->length != cmd->se_dev->dev_attrib.block_size) { 500 pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u" 501 " block_size: %u\n", cmd->t_data_nents, sg->length, 502 cmd->se_dev->dev_attrib.block_size); 503 return TCM_INVALID_CDB_FIELD; 504 } 505 506 ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL); 507 if (!ibr) 508 goto fail; 509 cmd->priv = ibr; 510 511 bio = iblock_get_bio(cmd, block_lba, 1); 512 if (!bio) 513 goto fail_free_ibr; 514 515 bio_list_init(&list); 516 bio_list_add(&list, bio); 517 518 atomic_set(&ibr->pending, 1); 519 520 while (sectors) { 521 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset) 522 != sg->length) { 523 524 bio = iblock_get_bio(cmd, block_lba, 1); 525 if (!bio) 526 goto fail_put_bios; 527 528 atomic_inc(&ibr->pending); 529 bio_list_add(&list, bio); 530 } 531 532 /* Always in 512 byte units for Linux/Block */ 533 block_lba += sg->length >> IBLOCK_LBA_SHIFT; 534 sectors -= 1; 535 } 536 537 iblock_submit_bios(&list, WRITE); 538 return 0; 539 540 fail_put_bios: 541 while ((bio = bio_list_pop(&list))) 542 bio_put(bio); 543 fail_free_ibr: 544 kfree(ibr); 545 fail: 546 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 547 } 548 549 enum { 550 Opt_udev_path, Opt_readonly, Opt_force, Opt_err 551 }; 552 553 static match_table_t tokens = { 554 {Opt_udev_path, "udev_path=%s"}, 555 {Opt_readonly, "readonly=%d"}, 556 {Opt_force, "force=%d"}, 557 {Opt_err, NULL} 558 }; 559 560 static ssize_t iblock_set_configfs_dev_params(struct se_device *dev, 561 const char *page, ssize_t count) 562 { 563 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 564 char *orig, *ptr, *arg_p, *opts; 565 substring_t args[MAX_OPT_ARGS]; 566 int ret = 0, token; 567 unsigned long tmp_readonly; 568 569 opts = kstrdup(page, GFP_KERNEL); 570 if (!opts) 571 return -ENOMEM; 572 573 orig = opts; 574 575 while ((ptr = strsep(&opts, ",\n")) != NULL) { 576 if (!*ptr) 577 continue; 578 579 token = match_token(ptr, tokens, args); 580 switch (token) { 581 case Opt_udev_path: 582 if (ib_dev->ibd_bd) { 583 pr_err("Unable to set udev_path= while" 584 " ib_dev->ibd_bd exists\n"); 585 ret = -EEXIST; 586 goto out; 587 } 588 if (match_strlcpy(ib_dev->ibd_udev_path, &args[0], 589 SE_UDEV_PATH_LEN) == 0) { 590 ret = -EINVAL; 591 break; 592 } 593 pr_debug("IBLOCK: Referencing UDEV path: %s\n", 594 ib_dev->ibd_udev_path); 595 ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH; 596 break; 597 case Opt_readonly: 598 arg_p = match_strdup(&args[0]); 599 if (!arg_p) { 600 ret = -ENOMEM; 601 break; 602 } 603 ret = strict_strtoul(arg_p, 0, &tmp_readonly); 604 kfree(arg_p); 605 if (ret < 0) { 606 pr_err("strict_strtoul() failed for" 607 " readonly=\n"); 608 goto out; 609 } 610 ib_dev->ibd_readonly = tmp_readonly; 611 pr_debug("IBLOCK: readonly: %d\n", ib_dev->ibd_readonly); 612 break; 613 case Opt_force: 614 break; 615 default: 616 break; 617 } 618 } 619 620 out: 621 kfree(orig); 622 return (!ret) ? count : ret; 623 } 624 625 static ssize_t iblock_show_configfs_dev_params(struct se_device *dev, char *b) 626 { 627 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 628 struct block_device *bd = ib_dev->ibd_bd; 629 char buf[BDEVNAME_SIZE]; 630 ssize_t bl = 0; 631 632 if (bd) 633 bl += sprintf(b + bl, "iBlock device: %s", 634 bdevname(bd, buf)); 635 if (ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH) 636 bl += sprintf(b + bl, " UDEV PATH: %s", 637 ib_dev->ibd_udev_path); 638 bl += sprintf(b + bl, " readonly: %d\n", ib_dev->ibd_readonly); 639 640 bl += sprintf(b + bl, " "); 641 if (bd) { 642 bl += sprintf(b + bl, "Major: %d Minor: %d %s\n", 643 MAJOR(bd->bd_dev), MINOR(bd->bd_dev), (!bd->bd_contains) ? 644 "" : (bd->bd_holder == ib_dev) ? 645 "CLAIMED: IBLOCK" : "CLAIMED: OS"); 646 } else { 647 bl += sprintf(b + bl, "Major: 0 Minor: 0\n"); 648 } 649 650 return bl; 651 } 652 653 static sense_reason_t 654 iblock_execute_rw(struct se_cmd *cmd) 655 { 656 struct scatterlist *sgl = cmd->t_data_sg; 657 u32 sgl_nents = cmd->t_data_nents; 658 enum dma_data_direction data_direction = cmd->data_direction; 659 struct se_device *dev = cmd->se_dev; 660 struct iblock_req *ibr; 661 struct bio *bio; 662 struct bio_list list; 663 struct scatterlist *sg; 664 u32 sg_num = sgl_nents; 665 sector_t block_lba; 666 unsigned bio_cnt; 667 int rw = 0; 668 int i; 669 670 if (data_direction == DMA_TO_DEVICE) { 671 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 672 struct request_queue *q = bdev_get_queue(ib_dev->ibd_bd); 673 /* 674 * Force writethrough using WRITE_FUA if a volatile write cache 675 * is not enabled, or if initiator set the Force Unit Access bit. 676 */ 677 if (q->flush_flags & REQ_FUA) { 678 if (cmd->se_cmd_flags & SCF_FUA) 679 rw = WRITE_FUA; 680 else if (!(q->flush_flags & REQ_FLUSH)) 681 rw = WRITE_FUA; 682 } else { 683 rw = WRITE; 684 } 685 } else { 686 rw = READ; 687 } 688 689 /* 690 * Convert the blocksize advertised to the initiator to the 512 byte 691 * units unconditionally used by the Linux block layer. 692 */ 693 if (dev->dev_attrib.block_size == 4096) 694 block_lba = (cmd->t_task_lba << 3); 695 else if (dev->dev_attrib.block_size == 2048) 696 block_lba = (cmd->t_task_lba << 2); 697 else if (dev->dev_attrib.block_size == 1024) 698 block_lba = (cmd->t_task_lba << 1); 699 else if (dev->dev_attrib.block_size == 512) 700 block_lba = cmd->t_task_lba; 701 else { 702 pr_err("Unsupported SCSI -> BLOCK LBA conversion:" 703 " %u\n", dev->dev_attrib.block_size); 704 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 705 } 706 707 ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL); 708 if (!ibr) 709 goto fail; 710 cmd->priv = ibr; 711 712 if (!sgl_nents) { 713 atomic_set(&ibr->pending, 1); 714 iblock_complete_cmd(cmd); 715 return 0; 716 } 717 718 bio = iblock_get_bio(cmd, block_lba, sgl_nents); 719 if (!bio) 720 goto fail_free_ibr; 721 722 bio_list_init(&list); 723 bio_list_add(&list, bio); 724 725 atomic_set(&ibr->pending, 2); 726 bio_cnt = 1; 727 728 for_each_sg(sgl, sg, sgl_nents, i) { 729 /* 730 * XXX: if the length the device accepts is shorter than the 731 * length of the S/G list entry this will cause and 732 * endless loop. Better hope no driver uses huge pages. 733 */ 734 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset) 735 != sg->length) { 736 if (bio_cnt >= IBLOCK_MAX_BIO_PER_TASK) { 737 iblock_submit_bios(&list, rw); 738 bio_cnt = 0; 739 } 740 741 bio = iblock_get_bio(cmd, block_lba, sg_num); 742 if (!bio) 743 goto fail_put_bios; 744 745 atomic_inc(&ibr->pending); 746 bio_list_add(&list, bio); 747 bio_cnt++; 748 } 749 750 /* Always in 512 byte units for Linux/Block */ 751 block_lba += sg->length >> IBLOCK_LBA_SHIFT; 752 sg_num--; 753 } 754 755 iblock_submit_bios(&list, rw); 756 iblock_complete_cmd(cmd); 757 return 0; 758 759 fail_put_bios: 760 while ((bio = bio_list_pop(&list))) 761 bio_put(bio); 762 fail_free_ibr: 763 kfree(ibr); 764 fail: 765 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 766 } 767 768 static sector_t iblock_get_blocks(struct se_device *dev) 769 { 770 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 771 struct block_device *bd = ib_dev->ibd_bd; 772 struct request_queue *q = bdev_get_queue(bd); 773 774 return iblock_emulate_read_cap_with_block_size(dev, bd, q); 775 } 776 777 static struct sbc_ops iblock_sbc_ops = { 778 .execute_rw = iblock_execute_rw, 779 .execute_sync_cache = iblock_execute_sync_cache, 780 .execute_write_same = iblock_execute_write_same, 781 .execute_write_same_unmap = iblock_execute_write_same_unmap, 782 .execute_unmap = iblock_execute_unmap, 783 }; 784 785 static sense_reason_t 786 iblock_parse_cdb(struct se_cmd *cmd) 787 { 788 return sbc_parse_cdb(cmd, &iblock_sbc_ops); 789 } 790 791 bool iblock_get_write_cache(struct se_device *dev) 792 { 793 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 794 struct block_device *bd = ib_dev->ibd_bd; 795 struct request_queue *q = bdev_get_queue(bd); 796 797 return q->flush_flags & REQ_FLUSH; 798 } 799 800 static struct se_subsystem_api iblock_template = { 801 .name = "iblock", 802 .inquiry_prod = "IBLOCK", 803 .inquiry_rev = IBLOCK_VERSION, 804 .owner = THIS_MODULE, 805 .transport_type = TRANSPORT_PLUGIN_VHBA_PDEV, 806 .attach_hba = iblock_attach_hba, 807 .detach_hba = iblock_detach_hba, 808 .alloc_device = iblock_alloc_device, 809 .configure_device = iblock_configure_device, 810 .free_device = iblock_free_device, 811 .parse_cdb = iblock_parse_cdb, 812 .set_configfs_dev_params = iblock_set_configfs_dev_params, 813 .show_configfs_dev_params = iblock_show_configfs_dev_params, 814 .get_device_type = sbc_get_device_type, 815 .get_blocks = iblock_get_blocks, 816 .get_write_cache = iblock_get_write_cache, 817 }; 818 819 static int __init iblock_module_init(void) 820 { 821 return transport_subsystem_register(&iblock_template); 822 } 823 824 static void __exit iblock_module_exit(void) 825 { 826 transport_subsystem_release(&iblock_template); 827 } 828 829 MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin"); 830 MODULE_AUTHOR("nab@Linux-iSCSI.org"); 831 MODULE_LICENSE("GPL"); 832 833 module_init(iblock_module_init); 834 module_exit(iblock_module_exit); 835