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 ib_dev->ibd_bio_set = bioset_create(IBLOCK_BIO_POOL_SIZE, 0, BIOSET_NEED_BVECS); 98 if (!ib_dev->ibd_bio_set) { 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_free(ib_dev->ibd_bio_set); 178 ib_dev->ibd_bio_set = NULL; 179 out: 180 return ret; 181 } 182 183 static void iblock_dev_call_rcu(struct rcu_head *p) 184 { 185 struct se_device *dev = container_of(p, struct se_device, rcu_head); 186 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 187 188 kfree(ib_dev); 189 } 190 191 static void iblock_free_device(struct se_device *dev) 192 { 193 call_rcu(&dev->rcu_head, iblock_dev_call_rcu); 194 } 195 196 static void iblock_destroy_device(struct se_device *dev) 197 { 198 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 199 200 if (ib_dev->ibd_bd != NULL) 201 blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL); 202 if (ib_dev->ibd_bio_set != NULL) 203 bioset_free(ib_dev->ibd_bio_set); 204 } 205 206 static unsigned long long iblock_emulate_read_cap_with_block_size( 207 struct se_device *dev, 208 struct block_device *bd, 209 struct request_queue *q) 210 { 211 unsigned long long blocks_long = (div_u64(i_size_read(bd->bd_inode), 212 bdev_logical_block_size(bd)) - 1); 213 u32 block_size = bdev_logical_block_size(bd); 214 215 if (block_size == dev->dev_attrib.block_size) 216 return blocks_long; 217 218 switch (block_size) { 219 case 4096: 220 switch (dev->dev_attrib.block_size) { 221 case 2048: 222 blocks_long <<= 1; 223 break; 224 case 1024: 225 blocks_long <<= 2; 226 break; 227 case 512: 228 blocks_long <<= 3; 229 default: 230 break; 231 } 232 break; 233 case 2048: 234 switch (dev->dev_attrib.block_size) { 235 case 4096: 236 blocks_long >>= 1; 237 break; 238 case 1024: 239 blocks_long <<= 1; 240 break; 241 case 512: 242 blocks_long <<= 2; 243 break; 244 default: 245 break; 246 } 247 break; 248 case 1024: 249 switch (dev->dev_attrib.block_size) { 250 case 4096: 251 blocks_long >>= 2; 252 break; 253 case 2048: 254 blocks_long >>= 1; 255 break; 256 case 512: 257 blocks_long <<= 1; 258 break; 259 default: 260 break; 261 } 262 break; 263 case 512: 264 switch (dev->dev_attrib.block_size) { 265 case 4096: 266 blocks_long >>= 3; 267 break; 268 case 2048: 269 blocks_long >>= 2; 270 break; 271 case 1024: 272 blocks_long >>= 1; 273 break; 274 default: 275 break; 276 } 277 break; 278 default: 279 break; 280 } 281 282 return blocks_long; 283 } 284 285 static void iblock_complete_cmd(struct se_cmd *cmd) 286 { 287 struct iblock_req *ibr = cmd->priv; 288 u8 status; 289 290 if (!refcount_dec_and_test(&ibr->pending)) 291 return; 292 293 if (atomic_read(&ibr->ib_bio_err_cnt)) 294 status = SAM_STAT_CHECK_CONDITION; 295 else 296 status = SAM_STAT_GOOD; 297 298 target_complete_cmd(cmd, status); 299 kfree(ibr); 300 } 301 302 static void iblock_bio_done(struct bio *bio) 303 { 304 struct se_cmd *cmd = bio->bi_private; 305 struct iblock_req *ibr = cmd->priv; 306 307 if (bio->bi_status) { 308 pr_err("bio error: %p, err: %d\n", bio, bio->bi_status); 309 /* 310 * Bump the ib_bio_err_cnt and release bio. 311 */ 312 atomic_inc(&ibr->ib_bio_err_cnt); 313 smp_mb__after_atomic(); 314 } 315 316 bio_put(bio); 317 318 iblock_complete_cmd(cmd); 319 } 320 321 static struct bio * 322 iblock_get_bio(struct se_cmd *cmd, sector_t lba, u32 sg_num, int op, 323 int op_flags) 324 { 325 struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev); 326 struct bio *bio; 327 328 /* 329 * Only allocate as many vector entries as the bio code allows us to, 330 * we'll loop later on until we have handled the whole request. 331 */ 332 if (sg_num > BIO_MAX_PAGES) 333 sg_num = BIO_MAX_PAGES; 334 335 bio = bio_alloc_bioset(GFP_NOIO, sg_num, ib_dev->ibd_bio_set); 336 if (!bio) { 337 pr_err("Unable to allocate memory for bio\n"); 338 return NULL; 339 } 340 341 bio_set_dev(bio, ib_dev->ibd_bd); 342 bio->bi_private = cmd; 343 bio->bi_end_io = &iblock_bio_done; 344 bio->bi_iter.bi_sector = lba; 345 bio_set_op_attrs(bio, op, op_flags); 346 347 return bio; 348 } 349 350 static void iblock_submit_bios(struct bio_list *list) 351 { 352 struct blk_plug plug; 353 struct bio *bio; 354 355 blk_start_plug(&plug); 356 while ((bio = bio_list_pop(list))) 357 submit_bio(bio); 358 blk_finish_plug(&plug); 359 } 360 361 static void iblock_end_io_flush(struct bio *bio) 362 { 363 struct se_cmd *cmd = bio->bi_private; 364 365 if (bio->bi_status) 366 pr_err("IBLOCK: cache flush failed: %d\n", bio->bi_status); 367 368 if (cmd) { 369 if (bio->bi_status) 370 target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION); 371 else 372 target_complete_cmd(cmd, SAM_STAT_GOOD); 373 } 374 375 bio_put(bio); 376 } 377 378 /* 379 * Implement SYCHRONIZE CACHE. Note that we can't handle lba ranges and must 380 * always flush the whole cache. 381 */ 382 static sense_reason_t 383 iblock_execute_sync_cache(struct se_cmd *cmd) 384 { 385 struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev); 386 int immed = (cmd->t_task_cdb[1] & 0x2); 387 struct bio *bio; 388 389 /* 390 * If the Immediate bit is set, queue up the GOOD response 391 * for this SYNCHRONIZE_CACHE op. 392 */ 393 if (immed) 394 target_complete_cmd(cmd, SAM_STAT_GOOD); 395 396 bio = bio_alloc(GFP_KERNEL, 0); 397 bio->bi_end_io = iblock_end_io_flush; 398 bio_set_dev(bio, ib_dev->ibd_bd); 399 bio->bi_opf = REQ_OP_WRITE | REQ_PREFLUSH; 400 if (!immed) 401 bio->bi_private = cmd; 402 submit_bio(bio); 403 return 0; 404 } 405 406 static sense_reason_t 407 iblock_execute_unmap(struct se_cmd *cmd, sector_t lba, sector_t nolb) 408 { 409 struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd; 410 struct se_device *dev = cmd->se_dev; 411 int ret; 412 413 ret = blkdev_issue_discard(bdev, 414 target_to_linux_sector(dev, lba), 415 target_to_linux_sector(dev, nolb), 416 GFP_KERNEL, 0); 417 if (ret < 0) { 418 pr_err("blkdev_issue_discard() failed: %d\n", ret); 419 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 420 } 421 422 return 0; 423 } 424 425 static sense_reason_t 426 iblock_execute_zero_out(struct block_device *bdev, struct se_cmd *cmd) 427 { 428 struct se_device *dev = cmd->se_dev; 429 struct scatterlist *sg = &cmd->t_data_sg[0]; 430 unsigned char *buf, zero = 0x00, *p = &zero; 431 int rc, ret; 432 433 buf = kmap(sg_page(sg)) + sg->offset; 434 if (!buf) 435 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 436 /* 437 * Fall back to block_execute_write_same() slow-path if 438 * incoming WRITE_SAME payload does not contain zeros. 439 */ 440 rc = memcmp(buf, p, cmd->data_length); 441 kunmap(sg_page(sg)); 442 443 if (rc) 444 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 445 446 ret = blkdev_issue_zeroout(bdev, 447 target_to_linux_sector(dev, cmd->t_task_lba), 448 target_to_linux_sector(dev, 449 sbc_get_write_same_sectors(cmd)), 450 GFP_KERNEL, false); 451 if (ret) 452 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 453 454 target_complete_cmd(cmd, GOOD); 455 return 0; 456 } 457 458 static sense_reason_t 459 iblock_execute_write_same(struct se_cmd *cmd) 460 { 461 struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd; 462 struct iblock_req *ibr; 463 struct scatterlist *sg; 464 struct bio *bio; 465 struct bio_list list; 466 struct se_device *dev = cmd->se_dev; 467 sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba); 468 sector_t sectors = target_to_linux_sector(dev, 469 sbc_get_write_same_sectors(cmd)); 470 471 if (cmd->prot_op) { 472 pr_err("WRITE_SAME: Protection information with IBLOCK" 473 " backends not supported\n"); 474 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 475 } 476 sg = &cmd->t_data_sg[0]; 477 478 if (cmd->t_data_nents > 1 || 479 sg->length != cmd->se_dev->dev_attrib.block_size) { 480 pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u" 481 " block_size: %u\n", cmd->t_data_nents, sg->length, 482 cmd->se_dev->dev_attrib.block_size); 483 return TCM_INVALID_CDB_FIELD; 484 } 485 486 if (bdev_write_zeroes_sectors(bdev)) { 487 if (!iblock_execute_zero_out(bdev, cmd)) 488 return 0; 489 } 490 491 ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL); 492 if (!ibr) 493 goto fail; 494 cmd->priv = ibr; 495 496 bio = iblock_get_bio(cmd, block_lba, 1, REQ_OP_WRITE, 0); 497 if (!bio) 498 goto fail_free_ibr; 499 500 bio_list_init(&list); 501 bio_list_add(&list, bio); 502 503 refcount_set(&ibr->pending, 1); 504 505 while (sectors) { 506 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset) 507 != sg->length) { 508 509 bio = iblock_get_bio(cmd, block_lba, 1, REQ_OP_WRITE, 510 0); 511 if (!bio) 512 goto fail_put_bios; 513 514 refcount_inc(&ibr->pending); 515 bio_list_add(&list, bio); 516 } 517 518 /* Always in 512 byte units for Linux/Block */ 519 block_lba += sg->length >> IBLOCK_LBA_SHIFT; 520 sectors -= 1; 521 } 522 523 iblock_submit_bios(&list); 524 return 0; 525 526 fail_put_bios: 527 while ((bio = bio_list_pop(&list))) 528 bio_put(bio); 529 fail_free_ibr: 530 kfree(ibr); 531 fail: 532 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 533 } 534 535 enum { 536 Opt_udev_path, Opt_readonly, Opt_force, Opt_err 537 }; 538 539 static match_table_t tokens = { 540 {Opt_udev_path, "udev_path=%s"}, 541 {Opt_readonly, "readonly=%d"}, 542 {Opt_force, "force=%d"}, 543 {Opt_err, NULL} 544 }; 545 546 static ssize_t iblock_set_configfs_dev_params(struct se_device *dev, 547 const char *page, ssize_t count) 548 { 549 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 550 char *orig, *ptr, *arg_p, *opts; 551 substring_t args[MAX_OPT_ARGS]; 552 int ret = 0, token; 553 unsigned long tmp_readonly; 554 555 opts = kstrdup(page, GFP_KERNEL); 556 if (!opts) 557 return -ENOMEM; 558 559 orig = opts; 560 561 while ((ptr = strsep(&opts, ",\n")) != NULL) { 562 if (!*ptr) 563 continue; 564 565 token = match_token(ptr, tokens, args); 566 switch (token) { 567 case Opt_udev_path: 568 if (ib_dev->ibd_bd) { 569 pr_err("Unable to set udev_path= while" 570 " ib_dev->ibd_bd exists\n"); 571 ret = -EEXIST; 572 goto out; 573 } 574 if (match_strlcpy(ib_dev->ibd_udev_path, &args[0], 575 SE_UDEV_PATH_LEN) == 0) { 576 ret = -EINVAL; 577 break; 578 } 579 pr_debug("IBLOCK: Referencing UDEV path: %s\n", 580 ib_dev->ibd_udev_path); 581 ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH; 582 break; 583 case Opt_readonly: 584 arg_p = match_strdup(&args[0]); 585 if (!arg_p) { 586 ret = -ENOMEM; 587 break; 588 } 589 ret = kstrtoul(arg_p, 0, &tmp_readonly); 590 kfree(arg_p); 591 if (ret < 0) { 592 pr_err("kstrtoul() failed for" 593 " readonly=\n"); 594 goto out; 595 } 596 ib_dev->ibd_readonly = tmp_readonly; 597 pr_debug("IBLOCK: readonly: %d\n", ib_dev->ibd_readonly); 598 break; 599 case Opt_force: 600 break; 601 default: 602 break; 603 } 604 } 605 606 out: 607 kfree(orig); 608 return (!ret) ? count : ret; 609 } 610 611 static ssize_t iblock_show_configfs_dev_params(struct se_device *dev, char *b) 612 { 613 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 614 struct block_device *bd = ib_dev->ibd_bd; 615 char buf[BDEVNAME_SIZE]; 616 ssize_t bl = 0; 617 618 if (bd) 619 bl += sprintf(b + bl, "iBlock device: %s", 620 bdevname(bd, buf)); 621 if (ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH) 622 bl += sprintf(b + bl, " UDEV PATH: %s", 623 ib_dev->ibd_udev_path); 624 bl += sprintf(b + bl, " readonly: %d\n", ib_dev->ibd_readonly); 625 626 bl += sprintf(b + bl, " "); 627 if (bd) { 628 bl += sprintf(b + bl, "Major: %d Minor: %d %s\n", 629 MAJOR(bd->bd_dev), MINOR(bd->bd_dev), (!bd->bd_contains) ? 630 "" : (bd->bd_holder == ib_dev) ? 631 "CLAIMED: IBLOCK" : "CLAIMED: OS"); 632 } else { 633 bl += sprintf(b + bl, "Major: 0 Minor: 0\n"); 634 } 635 636 return bl; 637 } 638 639 static int 640 iblock_alloc_bip(struct se_cmd *cmd, struct bio *bio) 641 { 642 struct se_device *dev = cmd->se_dev; 643 struct blk_integrity *bi; 644 struct bio_integrity_payload *bip; 645 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 646 struct scatterlist *sg; 647 int i, rc; 648 649 bi = bdev_get_integrity(ib_dev->ibd_bd); 650 if (!bi) { 651 pr_err("Unable to locate bio_integrity\n"); 652 return -ENODEV; 653 } 654 655 bip = bio_integrity_alloc(bio, GFP_NOIO, cmd->t_prot_nents); 656 if (IS_ERR(bip)) { 657 pr_err("Unable to allocate bio_integrity_payload\n"); 658 return PTR_ERR(bip); 659 } 660 661 bip->bip_iter.bi_size = (cmd->data_length / dev->dev_attrib.block_size) * 662 dev->prot_length; 663 bip->bip_iter.bi_sector = bio->bi_iter.bi_sector; 664 665 pr_debug("IBLOCK BIP Size: %u Sector: %llu\n", bip->bip_iter.bi_size, 666 (unsigned long long)bip->bip_iter.bi_sector); 667 668 for_each_sg(cmd->t_prot_sg, sg, cmd->t_prot_nents, i) { 669 670 rc = bio_integrity_add_page(bio, sg_page(sg), sg->length, 671 sg->offset); 672 if (rc != sg->length) { 673 pr_err("bio_integrity_add_page() failed; %d\n", rc); 674 return -ENOMEM; 675 } 676 677 pr_debug("Added bio integrity page: %p length: %d offset; %d\n", 678 sg_page(sg), sg->length, sg->offset); 679 } 680 681 return 0; 682 } 683 684 static sense_reason_t 685 iblock_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents, 686 enum dma_data_direction data_direction) 687 { 688 struct se_device *dev = cmd->se_dev; 689 sector_t block_lba = target_to_linux_sector(dev, cmd->t_task_lba); 690 struct iblock_req *ibr; 691 struct bio *bio, *bio_start; 692 struct bio_list list; 693 struct scatterlist *sg; 694 u32 sg_num = sgl_nents; 695 unsigned bio_cnt; 696 int i, op, op_flags = 0; 697 698 if (data_direction == DMA_TO_DEVICE) { 699 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 700 struct request_queue *q = bdev_get_queue(ib_dev->ibd_bd); 701 /* 702 * Force writethrough using REQ_FUA if a volatile write cache 703 * is not enabled, or if initiator set the Force Unit Access bit. 704 */ 705 op = REQ_OP_WRITE; 706 if (test_bit(QUEUE_FLAG_FUA, &q->queue_flags)) { 707 if (cmd->se_cmd_flags & SCF_FUA) 708 op_flags = REQ_FUA; 709 else if (!test_bit(QUEUE_FLAG_WC, &q->queue_flags)) 710 op_flags = REQ_FUA; 711 } 712 } else { 713 op = REQ_OP_READ; 714 } 715 716 ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL); 717 if (!ibr) 718 goto fail; 719 cmd->priv = ibr; 720 721 if (!sgl_nents) { 722 refcount_set(&ibr->pending, 1); 723 iblock_complete_cmd(cmd); 724 return 0; 725 } 726 727 bio = iblock_get_bio(cmd, block_lba, sgl_nents, op, op_flags); 728 if (!bio) 729 goto fail_free_ibr; 730 731 bio_start = bio; 732 bio_list_init(&list); 733 bio_list_add(&list, bio); 734 735 refcount_set(&ibr->pending, 2); 736 bio_cnt = 1; 737 738 for_each_sg(sgl, sg, sgl_nents, i) { 739 /* 740 * XXX: if the length the device accepts is shorter than the 741 * length of the S/G list entry this will cause and 742 * endless loop. Better hope no driver uses huge pages. 743 */ 744 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset) 745 != sg->length) { 746 if (bio_cnt >= IBLOCK_MAX_BIO_PER_TASK) { 747 iblock_submit_bios(&list); 748 bio_cnt = 0; 749 } 750 751 bio = iblock_get_bio(cmd, block_lba, sg_num, op, 752 op_flags); 753 if (!bio) 754 goto fail_put_bios; 755 756 refcount_inc(&ibr->pending); 757 bio_list_add(&list, bio); 758 bio_cnt++; 759 } 760 761 /* Always in 512 byte units for Linux/Block */ 762 block_lba += sg->length >> IBLOCK_LBA_SHIFT; 763 sg_num--; 764 } 765 766 if (cmd->prot_type && dev->dev_attrib.pi_prot_type) { 767 int rc = iblock_alloc_bip(cmd, bio_start); 768 if (rc) 769 goto fail_put_bios; 770 } 771 772 iblock_submit_bios(&list); 773 iblock_complete_cmd(cmd); 774 return 0; 775 776 fail_put_bios: 777 while ((bio = bio_list_pop(&list))) 778 bio_put(bio); 779 fail_free_ibr: 780 kfree(ibr); 781 fail: 782 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 783 } 784 785 static sector_t iblock_get_blocks(struct se_device *dev) 786 { 787 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 788 struct block_device *bd = ib_dev->ibd_bd; 789 struct request_queue *q = bdev_get_queue(bd); 790 791 return iblock_emulate_read_cap_with_block_size(dev, bd, q); 792 } 793 794 static sector_t iblock_get_alignment_offset_lbas(struct se_device *dev) 795 { 796 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 797 struct block_device *bd = ib_dev->ibd_bd; 798 int ret; 799 800 ret = bdev_alignment_offset(bd); 801 if (ret == -1) 802 return 0; 803 804 /* convert offset-bytes to offset-lbas */ 805 return ret / bdev_logical_block_size(bd); 806 } 807 808 static unsigned int iblock_get_lbppbe(struct se_device *dev) 809 { 810 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 811 struct block_device *bd = ib_dev->ibd_bd; 812 int logs_per_phys = bdev_physical_block_size(bd) / bdev_logical_block_size(bd); 813 814 return ilog2(logs_per_phys); 815 } 816 817 static unsigned int iblock_get_io_min(struct se_device *dev) 818 { 819 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 820 struct block_device *bd = ib_dev->ibd_bd; 821 822 return bdev_io_min(bd); 823 } 824 825 static unsigned int iblock_get_io_opt(struct se_device *dev) 826 { 827 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 828 struct block_device *bd = ib_dev->ibd_bd; 829 830 return bdev_io_opt(bd); 831 } 832 833 static struct sbc_ops iblock_sbc_ops = { 834 .execute_rw = iblock_execute_rw, 835 .execute_sync_cache = iblock_execute_sync_cache, 836 .execute_write_same = iblock_execute_write_same, 837 .execute_unmap = iblock_execute_unmap, 838 }; 839 840 static sense_reason_t 841 iblock_parse_cdb(struct se_cmd *cmd) 842 { 843 return sbc_parse_cdb(cmd, &iblock_sbc_ops); 844 } 845 846 static bool iblock_get_write_cache(struct se_device *dev) 847 { 848 struct iblock_dev *ib_dev = IBLOCK_DEV(dev); 849 struct block_device *bd = ib_dev->ibd_bd; 850 struct request_queue *q = bdev_get_queue(bd); 851 852 return test_bit(QUEUE_FLAG_WC, &q->queue_flags); 853 } 854 855 static const struct target_backend_ops iblock_ops = { 856 .name = "iblock", 857 .inquiry_prod = "IBLOCK", 858 .inquiry_rev = IBLOCK_VERSION, 859 .owner = THIS_MODULE, 860 .attach_hba = iblock_attach_hba, 861 .detach_hba = iblock_detach_hba, 862 .alloc_device = iblock_alloc_device, 863 .configure_device = iblock_configure_device, 864 .destroy_device = iblock_destroy_device, 865 .free_device = iblock_free_device, 866 .parse_cdb = iblock_parse_cdb, 867 .set_configfs_dev_params = iblock_set_configfs_dev_params, 868 .show_configfs_dev_params = iblock_show_configfs_dev_params, 869 .get_device_type = sbc_get_device_type, 870 .get_blocks = iblock_get_blocks, 871 .get_alignment_offset_lbas = iblock_get_alignment_offset_lbas, 872 .get_lbppbe = iblock_get_lbppbe, 873 .get_io_min = iblock_get_io_min, 874 .get_io_opt = iblock_get_io_opt, 875 .get_write_cache = iblock_get_write_cache, 876 .tb_dev_attrib_attrs = sbc_attrib_attrs, 877 }; 878 879 static int __init iblock_module_init(void) 880 { 881 return transport_backend_register(&iblock_ops); 882 } 883 884 static void __exit iblock_module_exit(void) 885 { 886 target_backend_unregister(&iblock_ops); 887 } 888 889 MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin"); 890 MODULE_AUTHOR("nab@Linux-iSCSI.org"); 891 MODULE_LICENSE("GPL"); 892 893 module_init(iblock_module_init); 894 module_exit(iblock_module_exit); 895