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, int op, 316 int op_flags) 317 { 318 struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev); 319 struct bio *bio; 320 321 /* 322 * Only allocate as many vector entries as the bio code allows us to, 323 * we'll loop later on until we have handled the whole request. 324 */ 325 if (sg_num > BIO_MAX_PAGES) 326 sg_num = BIO_MAX_PAGES; 327 328 bio = bio_alloc_bioset(GFP_NOIO, sg_num, ib_dev->ibd_bio_set); 329 if (!bio) { 330 pr_err("Unable to allocate memory for bio\n"); 331 return NULL; 332 } 333 334 bio->bi_bdev = ib_dev->ibd_bd; 335 bio->bi_private = cmd; 336 bio->bi_end_io = &iblock_bio_done; 337 bio->bi_iter.bi_sector = lba; 338 bio_set_op_attrs(bio, op, op_flags); 339 340 return bio; 341 } 342 343 static void iblock_submit_bios(struct bio_list *list) 344 { 345 struct blk_plug plug; 346 struct bio *bio; 347 348 blk_start_plug(&plug); 349 while ((bio = bio_list_pop(list))) 350 submit_bio(bio); 351 blk_finish_plug(&plug); 352 } 353 354 static void iblock_end_io_flush(struct bio *bio) 355 { 356 struct se_cmd *cmd = bio->bi_private; 357 358 if (bio->bi_error) 359 pr_err("IBLOCK: cache flush failed: %d\n", bio->bi_error); 360 361 if (cmd) { 362 if (bio->bi_error) 363 target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION); 364 else 365 target_complete_cmd(cmd, SAM_STAT_GOOD); 366 } 367 368 bio_put(bio); 369 } 370 371 /* 372 * Implement SYCHRONIZE CACHE. Note that we can't handle lba ranges and must 373 * always flush the whole cache. 374 */ 375 static sense_reason_t 376 iblock_execute_sync_cache(struct se_cmd *cmd) 377 { 378 struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev); 379 int immed = (cmd->t_task_cdb[1] & 0x2); 380 struct bio *bio; 381 382 /* 383 * If the Immediate bit is set, queue up the GOOD response 384 * for this SYNCHRONIZE_CACHE op. 385 */ 386 if (immed) 387 target_complete_cmd(cmd, SAM_STAT_GOOD); 388 389 bio = bio_alloc(GFP_KERNEL, 0); 390 bio->bi_end_io = iblock_end_io_flush; 391 bio->bi_bdev = ib_dev->ibd_bd; 392 bio->bi_rw = WRITE_FLUSH; 393 if (!immed) 394 bio->bi_private = cmd; 395 submit_bio(bio); 396 return 0; 397 } 398 399 static sense_reason_t 400 iblock_execute_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb) 401 { 402 struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd; 403 struct se_device *dev = cmd->se_dev; 404 int ret; 405 406 ret = blkdev_issue_discard(bdev, 407 target_to_linux_sector(dev, lba), 408 target_to_linux_sector(dev, nolb), 409 GFP_KERNEL, 0); 410 if (ret < 0) { 411 pr_err("blkdev_issue_discard() failed: %d\n", ret); 412 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 413 } 414 415 return 0; 416 } 417 418 static sense_reason_t 419 iblock_execute_write_same_direct(struct block_device *bdev, struct se_cmd *cmd) 420 { 421 struct se_device *dev = cmd->se_dev; 422 struct scatterlist *sg = &cmd->t_data_sg[0]; 423 struct page *page = NULL; 424 int ret; 425 426 if (sg->offset) { 427 page = alloc_page(GFP_KERNEL); 428 if (!page) 429 return TCM_OUT_OF_RESOURCES; 430 sg_copy_to_buffer(sg, cmd->t_data_nents, page_address(page), 431 dev->dev_attrib.block_size); 432 } 433 434 ret = blkdev_issue_write_same(bdev, 435 target_to_linux_sector(dev, cmd->t_task_lba), 436 target_to_linux_sector(dev, 437 sbc_get_write_same_sectors(cmd)), 438 GFP_KERNEL, page ? page : sg_page(sg)); 439 if (page) 440 __free_page(page); 441 if (ret) 442 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 443 444 target_complete_cmd(cmd, GOOD); 445 return 0; 446 } 447 448 static sense_reason_t 449 iblock_execute_write_same(struct se_cmd *cmd) 450 { 451 struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd; 452 struct iblock_req *ibr; 453 struct scatterlist *sg; 454 struct bio *bio; 455 struct bio_list list; 456 struct se_device *dev = cmd->se_dev; 457 sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba); 458 sector_t sectors = target_to_linux_sector(dev, 459 sbc_get_write_same_sectors(cmd)); 460 461 if (cmd->prot_op) { 462 pr_err("WRITE_SAME: Protection information with IBLOCK" 463 " backends not supported\n"); 464 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 465 } 466 sg = &cmd->t_data_sg[0]; 467 468 if (cmd->t_data_nents > 1 || 469 sg->length != cmd->se_dev->dev_attrib.block_size) { 470 pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u" 471 " block_size: %u\n", cmd->t_data_nents, sg->length, 472 cmd->se_dev->dev_attrib.block_size); 473 return TCM_INVALID_CDB_FIELD; 474 } 475 476 if (bdev_write_same(bdev)) 477 return iblock_execute_write_same_direct(bdev, cmd); 478 479 ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL); 480 if (!ibr) 481 goto fail; 482 cmd->priv = ibr; 483 484 bio = iblock_get_bio(cmd, block_lba, 1, REQ_OP_WRITE, 0); 485 if (!bio) 486 goto fail_free_ibr; 487 488 bio_list_init(&list); 489 bio_list_add(&list, bio); 490 491 atomic_set(&ibr->pending, 1); 492 493 while (sectors) { 494 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset) 495 != sg->length) { 496 497 bio = iblock_get_bio(cmd, block_lba, 1, REQ_OP_WRITE, 498 0); 499 if (!bio) 500 goto fail_put_bios; 501 502 atomic_inc(&ibr->pending); 503 bio_list_add(&list, bio); 504 } 505 506 /* Always in 512 byte units for Linux/Block */ 507 block_lba += sg->length >> IBLOCK_LBA_SHIFT; 508 sectors -= 1; 509 } 510 511 iblock_submit_bios(&list); 512 return 0; 513 514 fail_put_bios: 515 while ((bio = bio_list_pop(&list))) 516 bio_put(bio); 517 fail_free_ibr: 518 kfree(ibr); 519 fail: 520 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 521 } 522 523 enum { 524 Opt_udev_path, Opt_readonly, Opt_force, Opt_err 525 }; 526 527 static match_table_t tokens = { 528 {Opt_udev_path, "udev_path=%s"}, 529 {Opt_readonly, "readonly=%d"}, 530 {Opt_force, "force=%d"}, 531 {Opt_err, NULL} 532 }; 533 534 static ssize_t iblock_set_configfs_dev_params(struct se_device *dev, 535 const char *page, ssize_t count) 536 { 537 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 538 char *orig, *ptr, *arg_p, *opts; 539 substring_t args[MAX_OPT_ARGS]; 540 int ret = 0, token; 541 unsigned long tmp_readonly; 542 543 opts = kstrdup(page, GFP_KERNEL); 544 if (!opts) 545 return -ENOMEM; 546 547 orig = opts; 548 549 while ((ptr = strsep(&opts, ",\n")) != NULL) { 550 if (!*ptr) 551 continue; 552 553 token = match_token(ptr, tokens, args); 554 switch (token) { 555 case Opt_udev_path: 556 if (ib_dev->ibd_bd) { 557 pr_err("Unable to set udev_path= while" 558 " ib_dev->ibd_bd exists\n"); 559 ret = -EEXIST; 560 goto out; 561 } 562 if (match_strlcpy(ib_dev->ibd_udev_path, &args[0], 563 SE_UDEV_PATH_LEN) == 0) { 564 ret = -EINVAL; 565 break; 566 } 567 pr_debug("IBLOCK: Referencing UDEV path: %s\n", 568 ib_dev->ibd_udev_path); 569 ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH; 570 break; 571 case Opt_readonly: 572 arg_p = match_strdup(&args[0]); 573 if (!arg_p) { 574 ret = -ENOMEM; 575 break; 576 } 577 ret = kstrtoul(arg_p, 0, &tmp_readonly); 578 kfree(arg_p); 579 if (ret < 0) { 580 pr_err("kstrtoul() failed for" 581 " readonly=\n"); 582 goto out; 583 } 584 ib_dev->ibd_readonly = tmp_readonly; 585 pr_debug("IBLOCK: readonly: %d\n", ib_dev->ibd_readonly); 586 break; 587 case Opt_force: 588 break; 589 default: 590 break; 591 } 592 } 593 594 out: 595 kfree(orig); 596 return (!ret) ? count : ret; 597 } 598 599 static ssize_t iblock_show_configfs_dev_params(struct se_device *dev, char *b) 600 { 601 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 602 struct block_device *bd = ib_dev->ibd_bd; 603 char buf[BDEVNAME_SIZE]; 604 ssize_t bl = 0; 605 606 if (bd) 607 bl += sprintf(b + bl, "iBlock device: %s", 608 bdevname(bd, buf)); 609 if (ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH) 610 bl += sprintf(b + bl, " UDEV PATH: %s", 611 ib_dev->ibd_udev_path); 612 bl += sprintf(b + bl, " readonly: %d\n", ib_dev->ibd_readonly); 613 614 bl += sprintf(b + bl, " "); 615 if (bd) { 616 bl += sprintf(b + bl, "Major: %d Minor: %d %s\n", 617 MAJOR(bd->bd_dev), MINOR(bd->bd_dev), (!bd->bd_contains) ? 618 "" : (bd->bd_holder == ib_dev) ? 619 "CLAIMED: IBLOCK" : "CLAIMED: OS"); 620 } else { 621 bl += sprintf(b + bl, "Major: 0 Minor: 0\n"); 622 } 623 624 return bl; 625 } 626 627 static int 628 iblock_alloc_bip(struct se_cmd *cmd, struct bio *bio) 629 { 630 struct se_device *dev = cmd->se_dev; 631 struct blk_integrity *bi; 632 struct bio_integrity_payload *bip; 633 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 634 struct scatterlist *sg; 635 int i, rc; 636 637 bi = bdev_get_integrity(ib_dev->ibd_bd); 638 if (!bi) { 639 pr_err("Unable to locate bio_integrity\n"); 640 return -ENODEV; 641 } 642 643 bip = bio_integrity_alloc(bio, GFP_NOIO, cmd->t_prot_nents); 644 if (IS_ERR(bip)) { 645 pr_err("Unable to allocate bio_integrity_payload\n"); 646 return PTR_ERR(bip); 647 } 648 649 bip->bip_iter.bi_size = (cmd->data_length / dev->dev_attrib.block_size) * 650 dev->prot_length; 651 bip->bip_iter.bi_sector = bio->bi_iter.bi_sector; 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 for_each_sg(cmd->t_prot_sg, sg, cmd->t_prot_nents, i) { 657 658 rc = bio_integrity_add_page(bio, sg_page(sg), sg->length, 659 sg->offset); 660 if (rc != sg->length) { 661 pr_err("bio_integrity_add_page() failed; %d\n", rc); 662 return -ENOMEM; 663 } 664 665 pr_debug("Added bio integrity page: %p length: %d offset; %d\n", 666 sg_page(sg), sg->length, sg->offset); 667 } 668 669 return 0; 670 } 671 672 static sense_reason_t 673 iblock_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents, 674 enum dma_data_direction data_direction) 675 { 676 struct se_device *dev = cmd->se_dev; 677 sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba); 678 struct iblock_req *ibr; 679 struct bio *bio, *bio_start; 680 struct bio_list list; 681 struct scatterlist *sg; 682 u32 sg_num = sgl_nents; 683 unsigned bio_cnt; 684 int i, op, op_flags = 0; 685 686 if (data_direction == DMA_TO_DEVICE) { 687 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 688 struct request_queue *q = bdev_get_queue(ib_dev->ibd_bd); 689 /* 690 * Force writethrough using WRITE_FUA if a volatile write cache 691 * is not enabled, or if initiator set the Force Unit Access bit. 692 */ 693 op = REQ_OP_WRITE; 694 if (test_bit(QUEUE_FLAG_FUA, &q->queue_flags)) { 695 if (cmd->se_cmd_flags & SCF_FUA) 696 op_flags = WRITE_FUA; 697 else if (!test_bit(QUEUE_FLAG_WC, &q->queue_flags)) 698 op_flags = WRITE_FUA; 699 } 700 } else { 701 op = REQ_OP_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, op, op_flags); 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); 736 bio_cnt = 0; 737 } 738 739 bio = iblock_get_bio(cmd, block_lba, sg_num, op, 740 op_flags); 741 if (!bio) 742 goto fail_put_bios; 743 744 atomic_inc(&ibr->pending); 745 bio_list_add(&list, bio); 746 bio_cnt++; 747 } 748 749 /* Always in 512 byte units for Linux/Block */ 750 block_lba += sg->length >> IBLOCK_LBA_SHIFT; 751 sg_num--; 752 } 753 754 if (cmd->prot_type && dev->dev_attrib.pi_prot_type) { 755 int rc = iblock_alloc_bip(cmd, bio_start); 756 if (rc) 757 goto fail_put_bios; 758 } 759 760 iblock_submit_bios(&list); 761 iblock_complete_cmd(cmd); 762 return 0; 763 764 fail_put_bios: 765 while ((bio = bio_list_pop(&list))) 766 bio_put(bio); 767 fail_free_ibr: 768 kfree(ibr); 769 fail: 770 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 771 } 772 773 static sector_t iblock_get_blocks(struct se_device *dev) 774 { 775 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 776 struct block_device *bd = ib_dev->ibd_bd; 777 struct request_queue *q = bdev_get_queue(bd); 778 779 return iblock_emulate_read_cap_with_block_size(dev, bd, q); 780 } 781 782 static sector_t iblock_get_alignment_offset_lbas(struct se_device *dev) 783 { 784 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 785 struct block_device *bd = ib_dev->ibd_bd; 786 int ret; 787 788 ret = bdev_alignment_offset(bd); 789 if (ret == -1) 790 return 0; 791 792 /* convert offset-bytes to offset-lbas */ 793 return ret / bdev_logical_block_size(bd); 794 } 795 796 static unsigned int iblock_get_lbppbe(struct se_device *dev) 797 { 798 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 799 struct block_device *bd = ib_dev->ibd_bd; 800 int logs_per_phys = bdev_physical_block_size(bd) / bdev_logical_block_size(bd); 801 802 return ilog2(logs_per_phys); 803 } 804 805 static unsigned int iblock_get_io_min(struct se_device *dev) 806 { 807 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 808 struct block_device *bd = ib_dev->ibd_bd; 809 810 return bdev_io_min(bd); 811 } 812 813 static unsigned int iblock_get_io_opt(struct se_device *dev) 814 { 815 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 816 struct block_device *bd = ib_dev->ibd_bd; 817 818 return bdev_io_opt(bd); 819 } 820 821 static struct sbc_ops iblock_sbc_ops = { 822 .execute_rw = iblock_execute_rw, 823 .execute_sync_cache = iblock_execute_sync_cache, 824 .execute_write_same = iblock_execute_write_same, 825 .execute_unmap = iblock_execute_unmap, 826 }; 827 828 static sense_reason_t 829 iblock_parse_cdb(struct se_cmd *cmd) 830 { 831 return sbc_parse_cdb(cmd, &iblock_sbc_ops); 832 } 833 834 static bool iblock_get_write_cache(struct se_device *dev) 835 { 836 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 837 struct block_device *bd = ib_dev->ibd_bd; 838 struct request_queue *q = bdev_get_queue(bd); 839 840 return test_bit(QUEUE_FLAG_WC, &q->queue_flags); 841 } 842 843 static const struct target_backend_ops iblock_ops = { 844 .name = "iblock", 845 .inquiry_prod = "IBLOCK", 846 .inquiry_rev = IBLOCK_VERSION, 847 .owner = THIS_MODULE, 848 .attach_hba = iblock_attach_hba, 849 .detach_hba = iblock_detach_hba, 850 .alloc_device = iblock_alloc_device, 851 .configure_device = iblock_configure_device, 852 .free_device = iblock_free_device, 853 .parse_cdb = iblock_parse_cdb, 854 .set_configfs_dev_params = iblock_set_configfs_dev_params, 855 .show_configfs_dev_params = iblock_show_configfs_dev_params, 856 .get_device_type = sbc_get_device_type, 857 .get_blocks = iblock_get_blocks, 858 .get_alignment_offset_lbas = iblock_get_alignment_offset_lbas, 859 .get_lbppbe = iblock_get_lbppbe, 860 .get_io_min = iblock_get_io_min, 861 .get_io_opt = iblock_get_io_opt, 862 .get_write_cache = iblock_get_write_cache, 863 .tb_dev_attrib_attrs = sbc_attrib_attrs, 864 }; 865 866 static int __init iblock_module_init(void) 867 { 868 return transport_backend_register(&iblock_ops); 869 } 870 871 static void __exit iblock_module_exit(void) 872 { 873 target_backend_unregister(&iblock_ops); 874 } 875 876 MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin"); 877 MODULE_AUTHOR("nab@Linux-iSCSI.org"); 878 MODULE_LICENSE("GPL"); 879 880 module_init(iblock_module_init); 881 module_exit(iblock_module_exit); 882