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 2003-2013 Datera, Inc. 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_proto.h> 39 #include <asm/unaligned.h> 40 41 #include <target/target_core_base.h> 42 #include <target/target_core_backend.h> 43 44 #include "target_core_iblock.h" 45 46 #define IBLOCK_MAX_BIO_PER_TASK 32 /* max # of bios to submit at a time */ 47 #define IBLOCK_BIO_POOL_SIZE 128 48 49 static inline struct iblock_dev *IBLOCK_DEV(struct se_device *dev) 50 { 51 return container_of(dev, struct iblock_dev, dev); 52 } 53 54 55 static int iblock_attach_hba(struct se_hba *hba, u32 host_id) 56 { 57 pr_debug("CORE_HBA[%d] - TCM iBlock HBA Driver %s on" 58 " Generic Target Core Stack %s\n", hba->hba_id, 59 IBLOCK_VERSION, TARGET_CORE_VERSION); 60 return 0; 61 } 62 63 static void iblock_detach_hba(struct se_hba *hba) 64 { 65 } 66 67 static struct se_device *iblock_alloc_device(struct se_hba *hba, const char *name) 68 { 69 struct iblock_dev *ib_dev = NULL; 70 71 ib_dev = kzalloc(sizeof(struct iblock_dev), GFP_KERNEL); 72 if (!ib_dev) { 73 pr_err("Unable to allocate struct iblock_dev\n"); 74 return NULL; 75 } 76 77 pr_debug( "IBLOCK: Allocated ib_dev for %s\n", name); 78 79 return &ib_dev->dev; 80 } 81 82 static int iblock_configure_device(struct se_device *dev) 83 { 84 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 85 struct request_queue *q; 86 struct block_device *bd = NULL; 87 struct blk_integrity *bi; 88 fmode_t mode; 89 int ret = -ENOMEM; 90 91 if (!(ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)) { 92 pr_err("Missing udev_path= parameters for IBLOCK\n"); 93 return -EINVAL; 94 } 95 96 ib_dev->ibd_bio_set = bioset_create(IBLOCK_BIO_POOL_SIZE, 0); 97 if (!ib_dev->ibd_bio_set) { 98 pr_err("IBLOCK: Unable to create bioset\n"); 99 goto out; 100 } 101 102 pr_debug( "IBLOCK: Claiming struct block_device: %s\n", 103 ib_dev->ibd_udev_path); 104 105 mode = FMODE_READ|FMODE_EXCL; 106 if (!ib_dev->ibd_readonly) 107 mode |= FMODE_WRITE; 108 else 109 dev->dev_flags |= DF_READ_ONLY; 110 111 bd = blkdev_get_by_path(ib_dev->ibd_udev_path, mode, ib_dev); 112 if (IS_ERR(bd)) { 113 ret = PTR_ERR(bd); 114 goto out_free_bioset; 115 } 116 ib_dev->ibd_bd = bd; 117 118 q = bdev_get_queue(bd); 119 120 dev->dev_attrib.hw_block_size = bdev_logical_block_size(bd); 121 dev->dev_attrib.hw_max_sectors = queue_max_hw_sectors(q); 122 dev->dev_attrib.hw_queue_depth = q->nr_requests; 123 124 if (target_configure_unmap_from_queue(&dev->dev_attrib, q, 125 dev->dev_attrib.hw_block_size)) 126 pr_debug("IBLOCK: BLOCK Discard support available," 127 " disabled by default\n"); 128 129 /* 130 * Enable write same emulation for IBLOCK and use 0xFFFF as 131 * the smaller WRITE_SAME(10) only has a two-byte block count. 132 */ 133 dev->dev_attrib.max_write_same_len = 0xFFFF; 134 135 if (blk_queue_nonrot(q)) 136 dev->dev_attrib.is_nonrot = 1; 137 138 bi = bdev_get_integrity(bd); 139 if (bi) { 140 struct bio_set *bs = ib_dev->ibd_bio_set; 141 142 if (!strcmp(bi->profile->name, "T10-DIF-TYPE3-IP") || 143 !strcmp(bi->profile->name, "T10-DIF-TYPE1-IP")) { 144 pr_err("IBLOCK export of blk_integrity: %s not" 145 " supported\n", bi->profile->name); 146 ret = -ENOSYS; 147 goto out_blkdev_put; 148 } 149 150 if (!strcmp(bi->profile->name, "T10-DIF-TYPE3-CRC")) { 151 dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE3_PROT; 152 } else if (!strcmp(bi->profile->name, "T10-DIF-TYPE1-CRC")) { 153 dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE1_PROT; 154 } 155 156 if (dev->dev_attrib.pi_prot_type) { 157 if (bioset_integrity_create(bs, IBLOCK_BIO_POOL_SIZE) < 0) { 158 pr_err("Unable to allocate bioset for PI\n"); 159 ret = -ENOMEM; 160 goto out_blkdev_put; 161 } 162 pr_debug("IBLOCK setup BIP bs->bio_integrity_pool: %p\n", 163 bs->bio_integrity_pool); 164 } 165 dev->dev_attrib.hw_pi_prot_type = dev->dev_attrib.pi_prot_type; 166 } 167 168 return 0; 169 170 out_blkdev_put: 171 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL); 172 out_free_bioset: 173 bioset_free(ib_dev->ibd_bio_set); 174 ib_dev->ibd_bio_set = NULL; 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); 185 } 186 187 static void iblock_free_device(struct se_device *dev) 188 { 189 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 190 191 if (ib_dev->ibd_bd != NULL) 192 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL); 193 if (ib_dev->ibd_bio_set != NULL) 194 bioset_free(ib_dev->ibd_bio_set); 195 196 call_rcu(&dev->rcu_head, iblock_dev_call_rcu); 197 } 198 199 static unsigned long long iblock_emulate_read_cap_with_block_size( 200 struct se_device *dev, 201 struct block_device *bd, 202 struct request_queue *q) 203 { 204 unsigned long long blocks_long = (div_u64(i_size_read(bd->bd_inode), 205 bdev_logical_block_size(bd)) - 1); 206 u32 block_size = bdev_logical_block_size(bd); 207 208 if (block_size == dev->dev_attrib.block_size) 209 return blocks_long; 210 211 switch (block_size) { 212 case 4096: 213 switch (dev->dev_attrib.block_size) { 214 case 2048: 215 blocks_long <<= 1; 216 break; 217 case 1024: 218 blocks_long <<= 2; 219 break; 220 case 512: 221 blocks_long <<= 3; 222 default: 223 break; 224 } 225 break; 226 case 2048: 227 switch (dev->dev_attrib.block_size) { 228 case 4096: 229 blocks_long >>= 1; 230 break; 231 case 1024: 232 blocks_long <<= 1; 233 break; 234 case 512: 235 blocks_long <<= 2; 236 break; 237 default: 238 break; 239 } 240 break; 241 case 1024: 242 switch (dev->dev_attrib.block_size) { 243 case 4096: 244 blocks_long >>= 2; 245 break; 246 case 2048: 247 blocks_long >>= 1; 248 break; 249 case 512: 250 blocks_long <<= 1; 251 break; 252 default: 253 break; 254 } 255 break; 256 case 512: 257 switch (dev->dev_attrib.block_size) { 258 case 4096: 259 blocks_long >>= 3; 260 break; 261 case 2048: 262 blocks_long >>= 2; 263 break; 264 case 1024: 265 blocks_long >>= 1; 266 break; 267 default: 268 break; 269 } 270 break; 271 default: 272 break; 273 } 274 275 return blocks_long; 276 } 277 278 static void iblock_complete_cmd(struct se_cmd *cmd) 279 { 280 struct iblock_req *ibr = cmd->priv; 281 u8 status; 282 283 if (!atomic_dec_and_test(&ibr->pending)) 284 return; 285 286 if (atomic_read(&ibr->ib_bio_err_cnt)) 287 status = SAM_STAT_CHECK_CONDITION; 288 else 289 status = SAM_STAT_GOOD; 290 291 target_complete_cmd(cmd, status); 292 kfree(ibr); 293 } 294 295 static void iblock_bio_done(struct bio *bio) 296 { 297 struct se_cmd *cmd = bio->bi_private; 298 struct iblock_req *ibr = cmd->priv; 299 300 if (bio->bi_error) { 301 pr_err("bio error: %p, err: %d\n", bio, bio->bi_error); 302 /* 303 * Bump the ib_bio_err_cnt and release bio. 304 */ 305 atomic_inc(&ibr->ib_bio_err_cnt); 306 smp_mb__after_atomic(); 307 } 308 309 bio_put(bio); 310 311 iblock_complete_cmd(cmd); 312 } 313 314 static struct bio * 315 iblock_get_bio(struct se_cmd *cmd, sector_t lba, u32 sg_num) 316 { 317 struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev); 318 struct bio *bio; 319 320 /* 321 * Only allocate as many vector entries as the bio code allows us to, 322 * we'll loop later on until we have handled the whole request. 323 */ 324 if (sg_num > BIO_MAX_PAGES) 325 sg_num = BIO_MAX_PAGES; 326 327 bio = bio_alloc_bioset(GFP_NOIO, sg_num, ib_dev->ibd_bio_set); 328 if (!bio) { 329 pr_err("Unable to allocate memory for bio\n"); 330 return NULL; 331 } 332 333 bio->bi_bdev = ib_dev->ibd_bd; 334 bio->bi_private = cmd; 335 bio->bi_end_io = &iblock_bio_done; 336 bio->bi_iter.bi_sector = lba; 337 338 return bio; 339 } 340 341 static void iblock_submit_bios(struct bio_list *list, int rw) 342 { 343 struct blk_plug plug; 344 struct bio *bio; 345 346 blk_start_plug(&plug); 347 while ((bio = bio_list_pop(list))) 348 submit_bio(rw, bio); 349 blk_finish_plug(&plug); 350 } 351 352 static void iblock_end_io_flush(struct bio *bio) 353 { 354 struct se_cmd *cmd = bio->bi_private; 355 356 if (bio->bi_error) 357 pr_err("IBLOCK: cache flush failed: %d\n", bio->bi_error); 358 359 if (cmd) { 360 if (bio->bi_error) 361 target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION); 362 else 363 target_complete_cmd(cmd, SAM_STAT_GOOD); 364 } 365 366 bio_put(bio); 367 } 368 369 /* 370 * Implement SYCHRONIZE CACHE. Note that we can't handle lba ranges and must 371 * always flush the whole cache. 372 */ 373 static sense_reason_t 374 iblock_execute_sync_cache(struct se_cmd *cmd) 375 { 376 struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev); 377 int immed = (cmd->t_task_cdb[1] & 0x2); 378 struct bio *bio; 379 380 /* 381 * If the Immediate bit is set, queue up the GOOD response 382 * for this SYNCHRONIZE_CACHE op. 383 */ 384 if (immed) 385 target_complete_cmd(cmd, SAM_STAT_GOOD); 386 387 bio = bio_alloc(GFP_KERNEL, 0); 388 bio->bi_end_io = iblock_end_io_flush; 389 bio->bi_bdev = ib_dev->ibd_bd; 390 if (!immed) 391 bio->bi_private = cmd; 392 submit_bio(WRITE_FLUSH, bio); 393 return 0; 394 } 395 396 static sense_reason_t 397 iblock_execute_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb) 398 { 399 struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd; 400 struct se_device *dev = cmd->se_dev; 401 int ret; 402 403 ret = blkdev_issue_discard(bdev, 404 target_to_linux_sector(dev, lba), 405 target_to_linux_sector(dev, nolb), 406 GFP_KERNEL, 0); 407 if (ret < 0) { 408 pr_err("blkdev_issue_discard() failed: %d\n", ret); 409 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 410 } 411 412 return 0; 413 } 414 415 static sense_reason_t 416 iblock_execute_write_same_direct(struct block_device *bdev, struct se_cmd *cmd) 417 { 418 struct se_device *dev = cmd->se_dev; 419 struct scatterlist *sg = &cmd->t_data_sg[0]; 420 struct page *page = NULL; 421 int ret; 422 423 if (sg->offset) { 424 page = alloc_page(GFP_KERNEL); 425 if (!page) 426 return TCM_OUT_OF_RESOURCES; 427 sg_copy_to_buffer(sg, cmd->t_data_nents, page_address(page), 428 dev->dev_attrib.block_size); 429 } 430 431 ret = blkdev_issue_write_same(bdev, 432 target_to_linux_sector(dev, cmd->t_task_lba), 433 target_to_linux_sector(dev, 434 sbc_get_write_same_sectors(cmd)), 435 GFP_KERNEL, page ? page : sg_page(sg)); 436 if (page) 437 __free_page(page); 438 if (ret) 439 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 440 441 target_complete_cmd(cmd, GOOD); 442 return 0; 443 } 444 445 static sense_reason_t 446 iblock_execute_write_same(struct se_cmd *cmd) 447 { 448 struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd; 449 struct iblock_req *ibr; 450 struct scatterlist *sg; 451 struct bio *bio; 452 struct bio_list list; 453 struct se_device *dev = cmd->se_dev; 454 sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba); 455 sector_t sectors = target_to_linux_sector(dev, 456 sbc_get_write_same_sectors(cmd)); 457 458 if (cmd->prot_op) { 459 pr_err("WRITE_SAME: Protection information with IBLOCK" 460 " backends not supported\n"); 461 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 462 } 463 sg = &cmd->t_data_sg[0]; 464 465 if (cmd->t_data_nents > 1 || 466 sg->length != cmd->se_dev->dev_attrib.block_size) { 467 pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u" 468 " block_size: %u\n", cmd->t_data_nents, sg->length, 469 cmd->se_dev->dev_attrib.block_size); 470 return TCM_INVALID_CDB_FIELD; 471 } 472 473 if (bdev_write_same(bdev)) 474 return iblock_execute_write_same_direct(bdev, cmd); 475 476 ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL); 477 if (!ibr) 478 goto fail; 479 cmd->priv = ibr; 480 481 bio = iblock_get_bio(cmd, block_lba, 1); 482 if (!bio) 483 goto fail_free_ibr; 484 485 bio_list_init(&list); 486 bio_list_add(&list, bio); 487 488 atomic_set(&ibr->pending, 1); 489 490 while (sectors) { 491 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset) 492 != sg->length) { 493 494 bio = iblock_get_bio(cmd, block_lba, 1); 495 if (!bio) 496 goto fail_put_bios; 497 498 atomic_inc(&ibr->pending); 499 bio_list_add(&list, bio); 500 } 501 502 /* Always in 512 byte units for Linux/Block */ 503 block_lba += sg->length >> IBLOCK_LBA_SHIFT; 504 sectors -= 1; 505 } 506 507 iblock_submit_bios(&list, WRITE); 508 return 0; 509 510 fail_put_bios: 511 while ((bio = bio_list_pop(&list))) 512 bio_put(bio); 513 fail_free_ibr: 514 kfree(ibr); 515 fail: 516 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 517 } 518 519 enum { 520 Opt_udev_path, Opt_readonly, Opt_force, Opt_err 521 }; 522 523 static match_table_t tokens = { 524 {Opt_udev_path, "udev_path=%s"}, 525 {Opt_readonly, "readonly=%d"}, 526 {Opt_force, "force=%d"}, 527 {Opt_err, NULL} 528 }; 529 530 static ssize_t iblock_set_configfs_dev_params(struct se_device *dev, 531 const char *page, ssize_t count) 532 { 533 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 534 char *orig, *ptr, *arg_p, *opts; 535 substring_t args[MAX_OPT_ARGS]; 536 int ret = 0, token; 537 unsigned long tmp_readonly; 538 539 opts = kstrdup(page, GFP_KERNEL); 540 if (!opts) 541 return -ENOMEM; 542 543 orig = opts; 544 545 while ((ptr = strsep(&opts, ",\n")) != NULL) { 546 if (!*ptr) 547 continue; 548 549 token = match_token(ptr, tokens, args); 550 switch (token) { 551 case Opt_udev_path: 552 if (ib_dev->ibd_bd) { 553 pr_err("Unable to set udev_path= while" 554 " ib_dev->ibd_bd exists\n"); 555 ret = -EEXIST; 556 goto out; 557 } 558 if (match_strlcpy(ib_dev->ibd_udev_path, &args[0], 559 SE_UDEV_PATH_LEN) == 0) { 560 ret = -EINVAL; 561 break; 562 } 563 pr_debug("IBLOCK: Referencing UDEV path: %s\n", 564 ib_dev->ibd_udev_path); 565 ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH; 566 break; 567 case Opt_readonly: 568 arg_p = match_strdup(&args[0]); 569 if (!arg_p) { 570 ret = -ENOMEM; 571 break; 572 } 573 ret = kstrtoul(arg_p, 0, &tmp_readonly); 574 kfree(arg_p); 575 if (ret < 0) { 576 pr_err("kstrtoul() failed for" 577 " readonly=\n"); 578 goto out; 579 } 580 ib_dev->ibd_readonly = tmp_readonly; 581 pr_debug("IBLOCK: readonly: %d\n", ib_dev->ibd_readonly); 582 break; 583 case Opt_force: 584 break; 585 default: 586 break; 587 } 588 } 589 590 out: 591 kfree(orig); 592 return (!ret) ? count : ret; 593 } 594 595 static ssize_t iblock_show_configfs_dev_params(struct se_device *dev, char *b) 596 { 597 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 598 struct block_device *bd = ib_dev->ibd_bd; 599 char buf[BDEVNAME_SIZE]; 600 ssize_t bl = 0; 601 602 if (bd) 603 bl += sprintf(b + bl, "iBlock device: %s", 604 bdevname(bd, buf)); 605 if (ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH) 606 bl += sprintf(b + bl, " UDEV PATH: %s", 607 ib_dev->ibd_udev_path); 608 bl += sprintf(b + bl, " readonly: %d\n", ib_dev->ibd_readonly); 609 610 bl += sprintf(b + bl, " "); 611 if (bd) { 612 bl += sprintf(b + bl, "Major: %d Minor: %d %s\n", 613 MAJOR(bd->bd_dev), MINOR(bd->bd_dev), (!bd->bd_contains) ? 614 "" : (bd->bd_holder == ib_dev) ? 615 "CLAIMED: IBLOCK" : "CLAIMED: OS"); 616 } else { 617 bl += sprintf(b + bl, "Major: 0 Minor: 0\n"); 618 } 619 620 return bl; 621 } 622 623 static int 624 iblock_alloc_bip(struct se_cmd *cmd, struct bio *bio) 625 { 626 struct se_device *dev = cmd->se_dev; 627 struct blk_integrity *bi; 628 struct bio_integrity_payload *bip; 629 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 630 struct scatterlist *sg; 631 int i, rc; 632 633 bi = bdev_get_integrity(ib_dev->ibd_bd); 634 if (!bi) { 635 pr_err("Unable to locate bio_integrity\n"); 636 return -ENODEV; 637 } 638 639 bip = bio_integrity_alloc(bio, GFP_NOIO, cmd->t_prot_nents); 640 if (IS_ERR(bip)) { 641 pr_err("Unable to allocate bio_integrity_payload\n"); 642 return PTR_ERR(bip); 643 } 644 645 bip->bip_iter.bi_size = (cmd->data_length / dev->dev_attrib.block_size) * 646 dev->prot_length; 647 bip->bip_iter.bi_sector = bio->bi_iter.bi_sector; 648 649 pr_debug("IBLOCK BIP Size: %u Sector: %llu\n", bip->bip_iter.bi_size, 650 (unsigned long long)bip->bip_iter.bi_sector); 651 652 for_each_sg(cmd->t_prot_sg, sg, cmd->t_prot_nents, i) { 653 654 rc = bio_integrity_add_page(bio, sg_page(sg), sg->length, 655 sg->offset); 656 if (rc != sg->length) { 657 pr_err("bio_integrity_add_page() failed; %d\n", rc); 658 return -ENOMEM; 659 } 660 661 pr_debug("Added bio integrity page: %p length: %d offset; %d\n", 662 sg_page(sg), sg->length, sg->offset); 663 } 664 665 return 0; 666 } 667 668 static sense_reason_t 669 iblock_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents, 670 enum dma_data_direction data_direction) 671 { 672 struct se_device *dev = cmd->se_dev; 673 sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba); 674 struct iblock_req *ibr; 675 struct bio *bio, *bio_start; 676 struct bio_list list; 677 struct scatterlist *sg; 678 u32 sg_num = sgl_nents; 679 unsigned bio_cnt; 680 int rw = 0; 681 int i; 682 683 if (data_direction == DMA_TO_DEVICE) { 684 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 685 struct request_queue *q = bdev_get_queue(ib_dev->ibd_bd); 686 /* 687 * Force writethrough using WRITE_FUA if a volatile write cache 688 * is not enabled, or if initiator set the Force Unit Access bit. 689 */ 690 if (test_bit(QUEUE_FLAG_FUA, &q->queue_flags)) { 691 if (cmd->se_cmd_flags & SCF_FUA) 692 rw = WRITE_FUA; 693 else if (!test_bit(QUEUE_FLAG_WC, &q->queue_flags)) 694 rw = WRITE_FUA; 695 else 696 rw = WRITE; 697 } else { 698 rw = WRITE; 699 } 700 } else { 701 rw = READ; 702 } 703 704 ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL); 705 if (!ibr) 706 goto fail; 707 cmd->priv = ibr; 708 709 if (!sgl_nents) { 710 atomic_set(&ibr->pending, 1); 711 iblock_complete_cmd(cmd); 712 return 0; 713 } 714 715 bio = iblock_get_bio(cmd, block_lba, sgl_nents); 716 if (!bio) 717 goto fail_free_ibr; 718 719 bio_start = bio; 720 bio_list_init(&list); 721 bio_list_add(&list, bio); 722 723 atomic_set(&ibr->pending, 2); 724 bio_cnt = 1; 725 726 for_each_sg(sgl, sg, sgl_nents, i) { 727 /* 728 * XXX: if the length the device accepts is shorter than the 729 * length of the S/G list entry this will cause and 730 * endless loop. Better hope no driver uses huge pages. 731 */ 732 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset) 733 != sg->length) { 734 if (bio_cnt >= IBLOCK_MAX_BIO_PER_TASK) { 735 iblock_submit_bios(&list, rw); 736 bio_cnt = 0; 737 } 738 739 bio = iblock_get_bio(cmd, block_lba, sg_num); 740 if (!bio) 741 goto fail_put_bios; 742 743 atomic_inc(&ibr->pending); 744 bio_list_add(&list, bio); 745 bio_cnt++; 746 } 747 748 /* Always in 512 byte units for Linux/Block */ 749 block_lba += sg->length >> IBLOCK_LBA_SHIFT; 750 sg_num--; 751 } 752 753 if (cmd->prot_type && dev->dev_attrib.pi_prot_type) { 754 int rc = iblock_alloc_bip(cmd, bio_start); 755 if (rc) 756 goto fail_put_bios; 757 } 758 759 iblock_submit_bios(&list, rw); 760 iblock_complete_cmd(cmd); 761 return 0; 762 763 fail_put_bios: 764 while ((bio = bio_list_pop(&list))) 765 bio_put(bio); 766 fail_free_ibr: 767 kfree(ibr); 768 fail: 769 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 770 } 771 772 static sector_t iblock_get_blocks(struct se_device *dev) 773 { 774 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 775 struct block_device *bd = ib_dev->ibd_bd; 776 struct request_queue *q = bdev_get_queue(bd); 777 778 return iblock_emulate_read_cap_with_block_size(dev, bd, q); 779 } 780 781 static sector_t iblock_get_alignment_offset_lbas(struct se_device *dev) 782 { 783 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 784 struct block_device *bd = ib_dev->ibd_bd; 785 int ret; 786 787 ret = bdev_alignment_offset(bd); 788 if (ret == -1) 789 return 0; 790 791 /* convert offset-bytes to offset-lbas */ 792 return ret / bdev_logical_block_size(bd); 793 } 794 795 static unsigned int iblock_get_lbppbe(struct se_device *dev) 796 { 797 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 798 struct block_device *bd = ib_dev->ibd_bd; 799 int logs_per_phys = bdev_physical_block_size(bd) / bdev_logical_block_size(bd); 800 801 return ilog2(logs_per_phys); 802 } 803 804 static unsigned int iblock_get_io_min(struct se_device *dev) 805 { 806 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 807 struct block_device *bd = ib_dev->ibd_bd; 808 809 return bdev_io_min(bd); 810 } 811 812 static unsigned int iblock_get_io_opt(struct se_device *dev) 813 { 814 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 815 struct block_device *bd = ib_dev->ibd_bd; 816 817 return bdev_io_opt(bd); 818 } 819 820 static struct sbc_ops iblock_sbc_ops = { 821 .execute_rw = iblock_execute_rw, 822 .execute_sync_cache = iblock_execute_sync_cache, 823 .execute_write_same = iblock_execute_write_same, 824 .execute_unmap = iblock_execute_unmap, 825 }; 826 827 static sense_reason_t 828 iblock_parse_cdb(struct se_cmd *cmd) 829 { 830 return sbc_parse_cdb(cmd, &iblock_sbc_ops); 831 } 832 833 static bool iblock_get_write_cache(struct se_device *dev) 834 { 835 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 836 struct block_device *bd = ib_dev->ibd_bd; 837 struct request_queue *q = bdev_get_queue(bd); 838 839 return test_bit(QUEUE_FLAG_WC, &q->queue_flags); 840 } 841 842 static const struct target_backend_ops iblock_ops = { 843 .name = "iblock", 844 .inquiry_prod = "IBLOCK", 845 .inquiry_rev = IBLOCK_VERSION, 846 .owner = THIS_MODULE, 847 .attach_hba = iblock_attach_hba, 848 .detach_hba = iblock_detach_hba, 849 .alloc_device = iblock_alloc_device, 850 .configure_device = iblock_configure_device, 851 .free_device = iblock_free_device, 852 .parse_cdb = iblock_parse_cdb, 853 .set_configfs_dev_params = iblock_set_configfs_dev_params, 854 .show_configfs_dev_params = iblock_show_configfs_dev_params, 855 .get_device_type = sbc_get_device_type, 856 .get_blocks = iblock_get_blocks, 857 .get_alignment_offset_lbas = iblock_get_alignment_offset_lbas, 858 .get_lbppbe = iblock_get_lbppbe, 859 .get_io_min = iblock_get_io_min, 860 .get_io_opt = iblock_get_io_opt, 861 .get_write_cache = iblock_get_write_cache, 862 .tb_dev_attrib_attrs = sbc_attrib_attrs, 863 }; 864 865 static int __init iblock_module_init(void) 866 { 867 return transport_backend_register(&iblock_ops); 868 } 869 870 static void __exit iblock_module_exit(void) 871 { 872 target_backend_unregister(&iblock_ops); 873 } 874 875 MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin"); 876 MODULE_AUTHOR("nab@Linux-iSCSI.org"); 877 MODULE_LICENSE("GPL"); 878 879 module_init(iblock_module_init); 880 module_exit(iblock_module_exit); 881