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