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 pr_debug("IBLOCK: BLOCK Discard support available," 126 " disabled by default\n"); 127 128 /* 129 * Enable write same emulation for IBLOCK and use 0xFFFF as 130 * the smaller WRITE_SAME(10) only has a two-byte block count. 131 */ 132 dev->dev_attrib.max_write_same_len = 0xFFFF; 133 134 if (blk_queue_nonrot(q)) 135 dev->dev_attrib.is_nonrot = 1; 136 137 bi = bdev_get_integrity(bd); 138 if (bi) { 139 struct bio_set *bs = ib_dev->ibd_bio_set; 140 141 if (!strcmp(bi->profile->name, "T10-DIF-TYPE3-IP") || 142 !strcmp(bi->profile->name, "T10-DIF-TYPE1-IP")) { 143 pr_err("IBLOCK export of blk_integrity: %s not" 144 " supported\n", bi->profile->name); 145 ret = -ENOSYS; 146 goto out_blkdev_put; 147 } 148 149 if (!strcmp(bi->profile->name, "T10-DIF-TYPE3-CRC")) { 150 dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE3_PROT; 151 } else if (!strcmp(bi->profile->name, "T10-DIF-TYPE1-CRC")) { 152 dev->dev_attrib.pi_prot_type = TARGET_DIF_TYPE1_PROT; 153 } 154 155 if (dev->dev_attrib.pi_prot_type) { 156 if (bioset_integrity_create(bs, IBLOCK_BIO_POOL_SIZE) < 0) { 157 pr_err("Unable to allocate bioset for PI\n"); 158 ret = -ENOMEM; 159 goto out_blkdev_put; 160 } 161 pr_debug("IBLOCK setup BIP bs->bio_integrity_pool: %p\n", 162 bs->bio_integrity_pool); 163 } 164 dev->dev_attrib.hw_pi_prot_type = dev->dev_attrib.pi_prot_type; 165 } 166 167 return 0; 168 169 out_blkdev_put: 170 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL); 171 out_free_bioset: 172 bioset_free(ib_dev->ibd_bio_set); 173 ib_dev->ibd_bio_set = NULL; 174 out: 175 return ret; 176 } 177 178 static void iblock_dev_call_rcu(struct rcu_head *p) 179 { 180 struct se_device *dev = container_of(p, struct se_device, rcu_head); 181 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 182 183 kfree(ib_dev); 184 } 185 186 static void iblock_free_device(struct se_device *dev) 187 { 188 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 189 190 if (ib_dev->ibd_bd != NULL) 191 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL); 192 if (ib_dev->ibd_bio_set != NULL) 193 bioset_free(ib_dev->ibd_bio_set); 194 195 call_rcu(&dev->rcu_head, iblock_dev_call_rcu); 196 } 197 198 static unsigned long long iblock_emulate_read_cap_with_block_size( 199 struct se_device *dev, 200 struct block_device *bd, 201 struct request_queue *q) 202 { 203 unsigned long long blocks_long = (div_u64(i_size_read(bd->bd_inode), 204 bdev_logical_block_size(bd)) - 1); 205 u32 block_size = bdev_logical_block_size(bd); 206 207 if (block_size == dev->dev_attrib.block_size) 208 return blocks_long; 209 210 switch (block_size) { 211 case 4096: 212 switch (dev->dev_attrib.block_size) { 213 case 2048: 214 blocks_long <<= 1; 215 break; 216 case 1024: 217 blocks_long <<= 2; 218 break; 219 case 512: 220 blocks_long <<= 3; 221 default: 222 break; 223 } 224 break; 225 case 2048: 226 switch (dev->dev_attrib.block_size) { 227 case 4096: 228 blocks_long >>= 1; 229 break; 230 case 1024: 231 blocks_long <<= 1; 232 break; 233 case 512: 234 blocks_long <<= 2; 235 break; 236 default: 237 break; 238 } 239 break; 240 case 1024: 241 switch (dev->dev_attrib.block_size) { 242 case 4096: 243 blocks_long >>= 2; 244 break; 245 case 2048: 246 blocks_long >>= 1; 247 break; 248 case 512: 249 blocks_long <<= 1; 250 break; 251 default: 252 break; 253 } 254 break; 255 case 512: 256 switch (dev->dev_attrib.block_size) { 257 case 4096: 258 blocks_long >>= 3; 259 break; 260 case 2048: 261 blocks_long >>= 2; 262 break; 263 case 1024: 264 blocks_long >>= 1; 265 break; 266 default: 267 break; 268 } 269 break; 270 default: 271 break; 272 } 273 274 return blocks_long; 275 } 276 277 static void iblock_complete_cmd(struct se_cmd *cmd) 278 { 279 struct iblock_req *ibr = cmd->priv; 280 u8 status; 281 282 if (!atomic_dec_and_test(&ibr->pending)) 283 return; 284 285 if (atomic_read(&ibr->ib_bio_err_cnt)) 286 status = SAM_STAT_CHECK_CONDITION; 287 else 288 status = SAM_STAT_GOOD; 289 290 target_complete_cmd(cmd, status); 291 kfree(ibr); 292 } 293 294 static void iblock_bio_done(struct bio *bio) 295 { 296 struct se_cmd *cmd = bio->bi_private; 297 struct iblock_req *ibr = cmd->priv; 298 299 if (bio->bi_error) { 300 pr_err("bio error: %p, err: %d\n", bio, bio->bi_error); 301 /* 302 * Bump the ib_bio_err_cnt and release bio. 303 */ 304 atomic_inc(&ibr->ib_bio_err_cnt); 305 smp_mb__after_atomic(); 306 } 307 308 bio_put(bio); 309 310 iblock_complete_cmd(cmd); 311 } 312 313 static struct bio * 314 iblock_get_bio(struct se_cmd *cmd, sector_t lba, u32 sg_num, int op, 315 int op_flags) 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 bio_set_op_attrs(bio, op, op_flags); 338 339 return bio; 340 } 341 342 static void iblock_submit_bios(struct bio_list *list) 343 { 344 struct blk_plug plug; 345 struct bio *bio; 346 347 blk_start_plug(&plug); 348 while ((bio = bio_list_pop(list))) 349 submit_bio(bio); 350 blk_finish_plug(&plug); 351 } 352 353 static void iblock_end_io_flush(struct bio *bio) 354 { 355 struct se_cmd *cmd = bio->bi_private; 356 357 if (bio->bi_error) 358 pr_err("IBLOCK: cache flush failed: %d\n", bio->bi_error); 359 360 if (cmd) { 361 if (bio->bi_error) 362 target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION); 363 else 364 target_complete_cmd(cmd, SAM_STAT_GOOD); 365 } 366 367 bio_put(bio); 368 } 369 370 /* 371 * Implement SYCHRONIZE CACHE. Note that we can't handle lba ranges and must 372 * always flush the whole cache. 373 */ 374 static sense_reason_t 375 iblock_execute_sync_cache(struct se_cmd *cmd) 376 { 377 struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev); 378 int immed = (cmd->t_task_cdb[1] & 0x2); 379 struct bio *bio; 380 381 /* 382 * If the Immediate bit is set, queue up the GOOD response 383 * for this SYNCHRONIZE_CACHE op. 384 */ 385 if (immed) 386 target_complete_cmd(cmd, SAM_STAT_GOOD); 387 388 bio = bio_alloc(GFP_KERNEL, 0); 389 bio->bi_end_io = iblock_end_io_flush; 390 bio->bi_bdev = ib_dev->ibd_bd; 391 bio->bi_opf = REQ_OP_WRITE | REQ_PREFLUSH; 392 if (!immed) 393 bio->bi_private = cmd; 394 submit_bio(bio); 395 return 0; 396 } 397 398 static sense_reason_t 399 iblock_execute_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb) 400 { 401 struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd; 402 struct se_device *dev = cmd->se_dev; 403 int ret; 404 405 ret = blkdev_issue_discard(bdev, 406 target_to_linux_sector(dev, lba), 407 target_to_linux_sector(dev, nolb), 408 GFP_KERNEL, 0); 409 if (ret < 0) { 410 pr_err("blkdev_issue_discard() failed: %d\n", ret); 411 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 412 } 413 414 return 0; 415 } 416 417 static sense_reason_t 418 iblock_execute_write_same_direct(struct block_device *bdev, struct se_cmd *cmd) 419 { 420 struct se_device *dev = cmd->se_dev; 421 struct scatterlist *sg = &cmd->t_data_sg[0]; 422 struct page *page = NULL; 423 int ret; 424 425 if (sg->offset) { 426 page = alloc_page(GFP_KERNEL); 427 if (!page) 428 return TCM_OUT_OF_RESOURCES; 429 sg_copy_to_buffer(sg, cmd->t_data_nents, page_address(page), 430 dev->dev_attrib.block_size); 431 } 432 433 ret = blkdev_issue_write_same(bdev, 434 target_to_linux_sector(dev, cmd->t_task_lba), 435 target_to_linux_sector(dev, 436 sbc_get_write_same_sectors(cmd)), 437 GFP_KERNEL, page ? page : sg_page(sg)); 438 if (page) 439 __free_page(page); 440 if (ret) 441 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 442 443 target_complete_cmd(cmd, GOOD); 444 return 0; 445 } 446 447 static sense_reason_t 448 iblock_execute_write_same(struct se_cmd *cmd) 449 { 450 struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd; 451 struct iblock_req *ibr; 452 struct scatterlist *sg; 453 struct bio *bio; 454 struct bio_list list; 455 struct se_device *dev = cmd->se_dev; 456 sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba); 457 sector_t sectors = target_to_linux_sector(dev, 458 sbc_get_write_same_sectors(cmd)); 459 460 if (cmd->prot_op) { 461 pr_err("WRITE_SAME: Protection information with IBLOCK" 462 " backends not supported\n"); 463 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 464 } 465 sg = &cmd->t_data_sg[0]; 466 467 if (cmd->t_data_nents > 1 || 468 sg->length != cmd->se_dev->dev_attrib.block_size) { 469 pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u" 470 " block_size: %u\n", cmd->t_data_nents, sg->length, 471 cmd->se_dev->dev_attrib.block_size); 472 return TCM_INVALID_CDB_FIELD; 473 } 474 475 if (bdev_write_same(bdev)) 476 return iblock_execute_write_same_direct(bdev, cmd); 477 478 ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL); 479 if (!ibr) 480 goto fail; 481 cmd->priv = ibr; 482 483 bio = iblock_get_bio(cmd, block_lba, 1, REQ_OP_WRITE, 0); 484 if (!bio) 485 goto fail_free_ibr; 486 487 bio_list_init(&list); 488 bio_list_add(&list, bio); 489 490 atomic_set(&ibr->pending, 1); 491 492 while (sectors) { 493 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset) 494 != sg->length) { 495 496 bio = iblock_get_bio(cmd, block_lba, 1, REQ_OP_WRITE, 497 0); 498 if (!bio) 499 goto fail_put_bios; 500 501 atomic_inc(&ibr->pending); 502 bio_list_add(&list, bio); 503 } 504 505 /* Always in 512 byte units for Linux/Block */ 506 block_lba += sg->length >> IBLOCK_LBA_SHIFT; 507 sectors -= 1; 508 } 509 510 iblock_submit_bios(&list); 511 return 0; 512 513 fail_put_bios: 514 while ((bio = bio_list_pop(&list))) 515 bio_put(bio); 516 fail_free_ibr: 517 kfree(ibr); 518 fail: 519 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 520 } 521 522 enum { 523 Opt_udev_path, Opt_readonly, Opt_force, Opt_err 524 }; 525 526 static match_table_t tokens = { 527 {Opt_udev_path, "udev_path=%s"}, 528 {Opt_readonly, "readonly=%d"}, 529 {Opt_force, "force=%d"}, 530 {Opt_err, NULL} 531 }; 532 533 static ssize_t iblock_set_configfs_dev_params(struct se_device *dev, 534 const char *page, ssize_t count) 535 { 536 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 537 char *orig, *ptr, *arg_p, *opts; 538 substring_t args[MAX_OPT_ARGS]; 539 int ret = 0, token; 540 unsigned long tmp_readonly; 541 542 opts = kstrdup(page, GFP_KERNEL); 543 if (!opts) 544 return -ENOMEM; 545 546 orig = opts; 547 548 while ((ptr = strsep(&opts, ",\n")) != NULL) { 549 if (!*ptr) 550 continue; 551 552 token = match_token(ptr, tokens, args); 553 switch (token) { 554 case Opt_udev_path: 555 if (ib_dev->ibd_bd) { 556 pr_err("Unable to set udev_path= while" 557 " ib_dev->ibd_bd exists\n"); 558 ret = -EEXIST; 559 goto out; 560 } 561 if (match_strlcpy(ib_dev->ibd_udev_path, &args[0], 562 SE_UDEV_PATH_LEN) == 0) { 563 ret = -EINVAL; 564 break; 565 } 566 pr_debug("IBLOCK: Referencing UDEV path: %s\n", 567 ib_dev->ibd_udev_path); 568 ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH; 569 break; 570 case Opt_readonly: 571 arg_p = match_strdup(&args[0]); 572 if (!arg_p) { 573 ret = -ENOMEM; 574 break; 575 } 576 ret = kstrtoul(arg_p, 0, &tmp_readonly); 577 kfree(arg_p); 578 if (ret < 0) { 579 pr_err("kstrtoul() failed for" 580 " readonly=\n"); 581 goto out; 582 } 583 ib_dev->ibd_readonly = tmp_readonly; 584 pr_debug("IBLOCK: readonly: %d\n", ib_dev->ibd_readonly); 585 break; 586 case Opt_force: 587 break; 588 default: 589 break; 590 } 591 } 592 593 out: 594 kfree(orig); 595 return (!ret) ? count : ret; 596 } 597 598 static ssize_t iblock_show_configfs_dev_params(struct se_device *dev, char *b) 599 { 600 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 601 struct block_device *bd = ib_dev->ibd_bd; 602 char buf[BDEVNAME_SIZE]; 603 ssize_t bl = 0; 604 605 if (bd) 606 bl += sprintf(b + bl, "iBlock device: %s", 607 bdevname(bd, buf)); 608 if (ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH) 609 bl += sprintf(b + bl, " UDEV PATH: %s", 610 ib_dev->ibd_udev_path); 611 bl += sprintf(b + bl, " readonly: %d\n", ib_dev->ibd_readonly); 612 613 bl += sprintf(b + bl, " "); 614 if (bd) { 615 bl += sprintf(b + bl, "Major: %d Minor: %d %s\n", 616 MAJOR(bd->bd_dev), MINOR(bd->bd_dev), (!bd->bd_contains) ? 617 "" : (bd->bd_holder == ib_dev) ? 618 "CLAIMED: IBLOCK" : "CLAIMED: OS"); 619 } else { 620 bl += sprintf(b + bl, "Major: 0 Minor: 0\n"); 621 } 622 623 return bl; 624 } 625 626 static int 627 iblock_alloc_bip(struct se_cmd *cmd, struct bio *bio) 628 { 629 struct se_device *dev = cmd->se_dev; 630 struct blk_integrity *bi; 631 struct bio_integrity_payload *bip; 632 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 633 struct scatterlist *sg; 634 int i, rc; 635 636 bi = bdev_get_integrity(ib_dev->ibd_bd); 637 if (!bi) { 638 pr_err("Unable to locate bio_integrity\n"); 639 return -ENODEV; 640 } 641 642 bip = bio_integrity_alloc(bio, GFP_NOIO, cmd->t_prot_nents); 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 = (cmd->data_length / dev->dev_attrib.block_size) * 649 dev->prot_length; 650 bip->bip_iter.bi_sector = bio->bi_iter.bi_sector; 651 652 pr_debug("IBLOCK BIP Size: %u Sector: %llu\n", bip->bip_iter.bi_size, 653 (unsigned long long)bip->bip_iter.bi_sector); 654 655 for_each_sg(cmd->t_prot_sg, sg, cmd->t_prot_nents, i) { 656 657 rc = bio_integrity_add_page(bio, sg_page(sg), sg->length, 658 sg->offset); 659 if (rc != sg->length) { 660 pr_err("bio_integrity_add_page() failed; %d\n", rc); 661 return -ENOMEM; 662 } 663 664 pr_debug("Added bio integrity page: %p length: %d offset; %d\n", 665 sg_page(sg), sg->length, sg->offset); 666 } 667 668 return 0; 669 } 670 671 static sense_reason_t 672 iblock_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents, 673 enum dma_data_direction data_direction) 674 { 675 struct se_device *dev = cmd->se_dev; 676 sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba); 677 struct iblock_req *ibr; 678 struct bio *bio, *bio_start; 679 struct bio_list list; 680 struct scatterlist *sg; 681 u32 sg_num = sgl_nents; 682 unsigned bio_cnt; 683 int i, op, op_flags = 0; 684 685 if (data_direction == DMA_TO_DEVICE) { 686 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 687 struct request_queue *q = bdev_get_queue(ib_dev->ibd_bd); 688 /* 689 * Force writethrough using REQ_FUA if a volatile write cache 690 * is not enabled, or if initiator set the Force Unit Access bit. 691 */ 692 op = REQ_OP_WRITE; 693 if (test_bit(QUEUE_FLAG_FUA, &q->queue_flags)) { 694 if (cmd->se_cmd_flags & SCF_FUA) 695 op_flags = REQ_FUA; 696 else if (!test_bit(QUEUE_FLAG_WC, &q->queue_flags)) 697 op_flags = REQ_FUA; 698 } 699 } else { 700 op = REQ_OP_READ; 701 } 702 703 ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL); 704 if (!ibr) 705 goto fail; 706 cmd->priv = ibr; 707 708 if (!sgl_nents) { 709 atomic_set(&ibr->pending, 1); 710 iblock_complete_cmd(cmd); 711 return 0; 712 } 713 714 bio = iblock_get_bio(cmd, block_lba, sgl_nents, op, op_flags); 715 if (!bio) 716 goto fail_free_ibr; 717 718 bio_start = bio; 719 bio_list_init(&list); 720 bio_list_add(&list, bio); 721 722 atomic_set(&ibr->pending, 2); 723 bio_cnt = 1; 724 725 for_each_sg(sgl, sg, sgl_nents, i) { 726 /* 727 * XXX: if the length the device accepts is shorter than the 728 * length of the S/G list entry this will cause and 729 * endless loop. Better hope no driver uses huge pages. 730 */ 731 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset) 732 != sg->length) { 733 if (bio_cnt >= IBLOCK_MAX_BIO_PER_TASK) { 734 iblock_submit_bios(&list); 735 bio_cnt = 0; 736 } 737 738 bio = iblock_get_bio(cmd, block_lba, sg_num, op, 739 op_flags); 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); 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