| 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.h> |
| 39 | #include <scsi/scsi_host.h> |
| 40 | #include <asm/unaligned.h> |
| 41 | |
| 42 | #include <target/target_core_base.h> |
| 43 | #include <target/target_core_backend.h> |
| 44 | |
| 45 | #include "target_core_iblock.h" |
| 46 | |
| 47 | #define IBLOCK_MAX_BIO_PER_TASK 32 /* max # of bios to submit at a time */ |
| 48 | #define IBLOCK_BIO_POOL_SIZE 128 |
| 49 | |
| 50 | static inline struct iblock_dev *IBLOCK_DEV(struct se_device *dev) |
| 51 | { |
| 52 | return container_of(dev, struct iblock_dev, dev); |
| 53 | } |
| 54 | |
| 55 | |
| 56 | static struct se_subsystem_api iblock_template; |
| 57 | |
| 58 | /* iblock_attach_hba(): (Part of se_subsystem_api_t template) |
| 59 | * |
| 60 | * |
| 61 | */ |
| 62 | static int iblock_attach_hba(struct se_hba *hba, u32 host_id) |
| 63 | { |
| 64 | pr_debug("CORE_HBA[%d] - TCM iBlock HBA Driver %s on" |
| 65 | " Generic Target Core Stack %s\n", hba->hba_id, |
| 66 | IBLOCK_VERSION, TARGET_CORE_MOD_VERSION); |
| 67 | return 0; |
| 68 | } |
| 69 | |
| 70 | static void iblock_detach_hba(struct se_hba *hba) |
| 71 | { |
| 72 | } |
| 73 | |
| 74 | static struct se_device *iblock_alloc_device(struct se_hba *hba, const char *name) |
| 75 | { |
| 76 | struct iblock_dev *ib_dev = NULL; |
| 77 | |
| 78 | ib_dev = kzalloc(sizeof(struct iblock_dev), GFP_KERNEL); |
| 79 | if (!ib_dev) { |
| 80 | pr_err("Unable to allocate struct iblock_dev\n"); |
| 81 | return NULL; |
| 82 | } |
| 83 | |
| 84 | pr_debug( "IBLOCK: Allocated ib_dev for %s\n", name); |
| 85 | |
| 86 | return &ib_dev->dev; |
| 87 | } |
| 88 | |
| 89 | static int iblock_configure_device(struct se_device *dev) |
| 90 | { |
| 91 | struct iblock_dev *ib_dev = IBLOCK_DEV(dev); |
| 92 | struct request_queue *q; |
| 93 | struct block_device *bd = NULL; |
| 94 | fmode_t mode; |
| 95 | int ret = -ENOMEM; |
| 96 | |
| 97 | if (!(ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH)) { |
| 98 | pr_err("Missing udev_path= parameters for IBLOCK\n"); |
| 99 | return -EINVAL; |
| 100 | } |
| 101 | |
| 102 | ib_dev->ibd_bio_set = bioset_create(IBLOCK_BIO_POOL_SIZE, 0); |
| 103 | if (!ib_dev->ibd_bio_set) { |
| 104 | pr_err("IBLOCK: Unable to create bioset\n"); |
| 105 | goto out; |
| 106 | } |
| 107 | |
| 108 | pr_debug( "IBLOCK: Claiming struct block_device: %s\n", |
| 109 | ib_dev->ibd_udev_path); |
| 110 | |
| 111 | mode = FMODE_READ|FMODE_EXCL; |
| 112 | if (!ib_dev->ibd_readonly) |
| 113 | mode |= FMODE_WRITE; |
| 114 | |
| 115 | bd = blkdev_get_by_path(ib_dev->ibd_udev_path, mode, ib_dev); |
| 116 | if (IS_ERR(bd)) { |
| 117 | ret = PTR_ERR(bd); |
| 118 | goto out_free_bioset; |
| 119 | } |
| 120 | ib_dev->ibd_bd = bd; |
| 121 | |
| 122 | q = bdev_get_queue(bd); |
| 123 | |
| 124 | dev->dev_attrib.hw_block_size = bdev_logical_block_size(bd); |
| 125 | dev->dev_attrib.hw_max_sectors = UINT_MAX; |
| 126 | dev->dev_attrib.hw_queue_depth = q->nr_requests; |
| 127 | |
| 128 | /* |
| 129 | * Check if the underlying struct block_device request_queue supports |
| 130 | * the QUEUE_FLAG_DISCARD bit for UNMAP/WRITE_SAME in SCSI + TRIM |
| 131 | * in ATA and we need to set TPE=1 |
| 132 | */ |
| 133 | if (blk_queue_discard(q)) { |
| 134 | dev->dev_attrib.max_unmap_lba_count = |
| 135 | q->limits.max_discard_sectors; |
| 136 | |
| 137 | /* |
| 138 | * Currently hardcoded to 1 in Linux/SCSI code.. |
| 139 | */ |
| 140 | dev->dev_attrib.max_unmap_block_desc_count = 1; |
| 141 | dev->dev_attrib.unmap_granularity = |
| 142 | q->limits.discard_granularity >> 9; |
| 143 | dev->dev_attrib.unmap_granularity_alignment = |
| 144 | q->limits.discard_alignment; |
| 145 | |
| 146 | pr_debug("IBLOCK: BLOCK Discard support available," |
| 147 | " disabled by default\n"); |
| 148 | } |
| 149 | /* |
| 150 | * Enable write same emulation for IBLOCK and use 0xFFFF as |
| 151 | * the smaller WRITE_SAME(10) only has a two-byte block count. |
| 152 | */ |
| 153 | dev->dev_attrib.max_write_same_len = 0xFFFF; |
| 154 | |
| 155 | if (blk_queue_nonrot(q)) |
| 156 | dev->dev_attrib.is_nonrot = 1; |
| 157 | |
| 158 | return 0; |
| 159 | |
| 160 | out_free_bioset: |
| 161 | bioset_free(ib_dev->ibd_bio_set); |
| 162 | ib_dev->ibd_bio_set = NULL; |
| 163 | out: |
| 164 | return ret; |
| 165 | } |
| 166 | |
| 167 | static void iblock_free_device(struct se_device *dev) |
| 168 | { |
| 169 | struct iblock_dev *ib_dev = IBLOCK_DEV(dev); |
| 170 | |
| 171 | if (ib_dev->ibd_bd != NULL) |
| 172 | blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL); |
| 173 | if (ib_dev->ibd_bio_set != NULL) |
| 174 | bioset_free(ib_dev->ibd_bio_set); |
| 175 | kfree(ib_dev); |
| 176 | } |
| 177 | |
| 178 | static unsigned long long iblock_emulate_read_cap_with_block_size( |
| 179 | struct se_device *dev, |
| 180 | struct block_device *bd, |
| 181 | struct request_queue *q) |
| 182 | { |
| 183 | unsigned long long blocks_long = (div_u64(i_size_read(bd->bd_inode), |
| 184 | bdev_logical_block_size(bd)) - 1); |
| 185 | u32 block_size = bdev_logical_block_size(bd); |
| 186 | |
| 187 | if (block_size == dev->dev_attrib.block_size) |
| 188 | return blocks_long; |
| 189 | |
| 190 | switch (block_size) { |
| 191 | case 4096: |
| 192 | switch (dev->dev_attrib.block_size) { |
| 193 | case 2048: |
| 194 | blocks_long <<= 1; |
| 195 | break; |
| 196 | case 1024: |
| 197 | blocks_long <<= 2; |
| 198 | break; |
| 199 | case 512: |
| 200 | blocks_long <<= 3; |
| 201 | default: |
| 202 | break; |
| 203 | } |
| 204 | break; |
| 205 | case 2048: |
| 206 | switch (dev->dev_attrib.block_size) { |
| 207 | case 4096: |
| 208 | blocks_long >>= 1; |
| 209 | break; |
| 210 | case 1024: |
| 211 | blocks_long <<= 1; |
| 212 | break; |
| 213 | case 512: |
| 214 | blocks_long <<= 2; |
| 215 | break; |
| 216 | default: |
| 217 | break; |
| 218 | } |
| 219 | break; |
| 220 | case 1024: |
| 221 | switch (dev->dev_attrib.block_size) { |
| 222 | case 4096: |
| 223 | blocks_long >>= 2; |
| 224 | break; |
| 225 | case 2048: |
| 226 | blocks_long >>= 1; |
| 227 | break; |
| 228 | case 512: |
| 229 | blocks_long <<= 1; |
| 230 | break; |
| 231 | default: |
| 232 | break; |
| 233 | } |
| 234 | break; |
| 235 | case 512: |
| 236 | switch (dev->dev_attrib.block_size) { |
| 237 | case 4096: |
| 238 | blocks_long >>= 3; |
| 239 | break; |
| 240 | case 2048: |
| 241 | blocks_long >>= 2; |
| 242 | break; |
| 243 | case 1024: |
| 244 | blocks_long >>= 1; |
| 245 | break; |
| 246 | default: |
| 247 | break; |
| 248 | } |
| 249 | break; |
| 250 | default: |
| 251 | break; |
| 252 | } |
| 253 | |
| 254 | return blocks_long; |
| 255 | } |
| 256 | |
| 257 | static void iblock_complete_cmd(struct se_cmd *cmd) |
| 258 | { |
| 259 | struct iblock_req *ibr = cmd->priv; |
| 260 | u8 status; |
| 261 | |
| 262 | if (!atomic_dec_and_test(&ibr->pending)) |
| 263 | return; |
| 264 | |
| 265 | if (atomic_read(&ibr->ib_bio_err_cnt)) |
| 266 | status = SAM_STAT_CHECK_CONDITION; |
| 267 | else |
| 268 | status = SAM_STAT_GOOD; |
| 269 | |
| 270 | target_complete_cmd(cmd, status); |
| 271 | kfree(ibr); |
| 272 | } |
| 273 | |
| 274 | static void iblock_bio_done(struct bio *bio, int err) |
| 275 | { |
| 276 | struct se_cmd *cmd = bio->bi_private; |
| 277 | struct iblock_req *ibr = cmd->priv; |
| 278 | |
| 279 | /* |
| 280 | * Set -EIO if !BIO_UPTODATE and the passed is still err=0 |
| 281 | */ |
| 282 | if (!test_bit(BIO_UPTODATE, &bio->bi_flags) && !err) |
| 283 | err = -EIO; |
| 284 | |
| 285 | if (err != 0) { |
| 286 | pr_err("test_bit(BIO_UPTODATE) failed for bio: %p," |
| 287 | " err: %d\n", bio, err); |
| 288 | /* |
| 289 | * Bump the ib_bio_err_cnt and release bio. |
| 290 | */ |
| 291 | atomic_inc(&ibr->ib_bio_err_cnt); |
| 292 | smp_mb__after_atomic_inc(); |
| 293 | } |
| 294 | |
| 295 | bio_put(bio); |
| 296 | |
| 297 | iblock_complete_cmd(cmd); |
| 298 | } |
| 299 | |
| 300 | static struct bio * |
| 301 | iblock_get_bio(struct se_cmd *cmd, sector_t lba, u32 sg_num) |
| 302 | { |
| 303 | struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev); |
| 304 | struct bio *bio; |
| 305 | |
| 306 | /* |
| 307 | * Only allocate as many vector entries as the bio code allows us to, |
| 308 | * we'll loop later on until we have handled the whole request. |
| 309 | */ |
| 310 | if (sg_num > BIO_MAX_PAGES) |
| 311 | sg_num = BIO_MAX_PAGES; |
| 312 | |
| 313 | bio = bio_alloc_bioset(GFP_NOIO, sg_num, ib_dev->ibd_bio_set); |
| 314 | if (!bio) { |
| 315 | pr_err("Unable to allocate memory for bio\n"); |
| 316 | return NULL; |
| 317 | } |
| 318 | |
| 319 | bio->bi_bdev = ib_dev->ibd_bd; |
| 320 | bio->bi_private = cmd; |
| 321 | bio->bi_end_io = &iblock_bio_done; |
| 322 | bio->bi_iter.bi_sector = lba; |
| 323 | |
| 324 | return bio; |
| 325 | } |
| 326 | |
| 327 | static void iblock_submit_bios(struct bio_list *list, int rw) |
| 328 | { |
| 329 | struct blk_plug plug; |
| 330 | struct bio *bio; |
| 331 | |
| 332 | blk_start_plug(&plug); |
| 333 | while ((bio = bio_list_pop(list))) |
| 334 | submit_bio(rw, bio); |
| 335 | blk_finish_plug(&plug); |
| 336 | } |
| 337 | |
| 338 | static void iblock_end_io_flush(struct bio *bio, int err) |
| 339 | { |
| 340 | struct se_cmd *cmd = bio->bi_private; |
| 341 | |
| 342 | if (err) |
| 343 | pr_err("IBLOCK: cache flush failed: %d\n", err); |
| 344 | |
| 345 | if (cmd) { |
| 346 | if (err) |
| 347 | target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION); |
| 348 | else |
| 349 | target_complete_cmd(cmd, SAM_STAT_GOOD); |
| 350 | } |
| 351 | |
| 352 | bio_put(bio); |
| 353 | } |
| 354 | |
| 355 | /* |
| 356 | * Implement SYCHRONIZE CACHE. Note that we can't handle lba ranges and must |
| 357 | * always flush the whole cache. |
| 358 | */ |
| 359 | static sense_reason_t |
| 360 | iblock_execute_sync_cache(struct se_cmd *cmd) |
| 361 | { |
| 362 | struct iblock_dev *ib_dev = IBLOCK_DEV(cmd->se_dev); |
| 363 | int immed = (cmd->t_task_cdb[1] & 0x2); |
| 364 | struct bio *bio; |
| 365 | |
| 366 | /* |
| 367 | * If the Immediate bit is set, queue up the GOOD response |
| 368 | * for this SYNCHRONIZE_CACHE op. |
| 369 | */ |
| 370 | if (immed) |
| 371 | target_complete_cmd(cmd, SAM_STAT_GOOD); |
| 372 | |
| 373 | bio = bio_alloc(GFP_KERNEL, 0); |
| 374 | bio->bi_end_io = iblock_end_io_flush; |
| 375 | bio->bi_bdev = ib_dev->ibd_bd; |
| 376 | if (!immed) |
| 377 | bio->bi_private = cmd; |
| 378 | submit_bio(WRITE_FLUSH, bio); |
| 379 | return 0; |
| 380 | } |
| 381 | |
| 382 | static sense_reason_t |
| 383 | iblock_do_unmap(struct se_cmd *cmd, void *priv, |
| 384 | sector_t lba, sector_t nolb) |
| 385 | { |
| 386 | struct block_device *bdev = priv; |
| 387 | int ret; |
| 388 | |
| 389 | ret = blkdev_issue_discard(bdev, lba, nolb, GFP_KERNEL, 0); |
| 390 | if (ret < 0) { |
| 391 | pr_err("blkdev_issue_discard() failed: %d\n", ret); |
| 392 | return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; |
| 393 | } |
| 394 | |
| 395 | return 0; |
| 396 | } |
| 397 | |
| 398 | static sense_reason_t |
| 399 | iblock_execute_unmap(struct se_cmd *cmd) |
| 400 | { |
| 401 | struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd; |
| 402 | |
| 403 | return sbc_execute_unmap(cmd, iblock_do_unmap, bdev); |
| 404 | } |
| 405 | |
| 406 | static sense_reason_t |
| 407 | iblock_execute_write_same_unmap(struct se_cmd *cmd) |
| 408 | { |
| 409 | struct block_device *bdev = IBLOCK_DEV(cmd->se_dev)->ibd_bd; |
| 410 | sector_t lba = cmd->t_task_lba; |
| 411 | sector_t nolb = sbc_get_write_same_sectors(cmd); |
| 412 | int ret; |
| 413 | |
| 414 | ret = iblock_do_unmap(cmd, bdev, lba, nolb); |
| 415 | if (ret) |
| 416 | return ret; |
| 417 | |
| 418 | target_complete_cmd(cmd, GOOD); |
| 419 | return 0; |
| 420 | } |
| 421 | |
| 422 | static sense_reason_t |
| 423 | iblock_execute_write_same(struct se_cmd *cmd) |
| 424 | { |
| 425 | struct iblock_req *ibr; |
| 426 | struct scatterlist *sg; |
| 427 | struct bio *bio; |
| 428 | struct bio_list list; |
| 429 | sector_t block_lba = cmd->t_task_lba; |
| 430 | sector_t sectors = sbc_get_write_same_sectors(cmd); |
| 431 | |
| 432 | sg = &cmd->t_data_sg[0]; |
| 433 | |
| 434 | if (cmd->t_data_nents > 1 || |
| 435 | sg->length != cmd->se_dev->dev_attrib.block_size) { |
| 436 | pr_err("WRITE_SAME: Illegal SGL t_data_nents: %u length: %u" |
| 437 | " block_size: %u\n", cmd->t_data_nents, sg->length, |
| 438 | cmd->se_dev->dev_attrib.block_size); |
| 439 | return TCM_INVALID_CDB_FIELD; |
| 440 | } |
| 441 | |
| 442 | ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL); |
| 443 | if (!ibr) |
| 444 | goto fail; |
| 445 | cmd->priv = ibr; |
| 446 | |
| 447 | bio = iblock_get_bio(cmd, block_lba, 1); |
| 448 | if (!bio) |
| 449 | goto fail_free_ibr; |
| 450 | |
| 451 | bio_list_init(&list); |
| 452 | bio_list_add(&list, bio); |
| 453 | |
| 454 | atomic_set(&ibr->pending, 1); |
| 455 | |
| 456 | while (sectors) { |
| 457 | while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset) |
| 458 | != sg->length) { |
| 459 | |
| 460 | bio = iblock_get_bio(cmd, block_lba, 1); |
| 461 | if (!bio) |
| 462 | goto fail_put_bios; |
| 463 | |
| 464 | atomic_inc(&ibr->pending); |
| 465 | bio_list_add(&list, bio); |
| 466 | } |
| 467 | |
| 468 | /* Always in 512 byte units for Linux/Block */ |
| 469 | block_lba += sg->length >> IBLOCK_LBA_SHIFT; |
| 470 | sectors -= 1; |
| 471 | } |
| 472 | |
| 473 | iblock_submit_bios(&list, WRITE); |
| 474 | return 0; |
| 475 | |
| 476 | fail_put_bios: |
| 477 | while ((bio = bio_list_pop(&list))) |
| 478 | bio_put(bio); |
| 479 | fail_free_ibr: |
| 480 | kfree(ibr); |
| 481 | fail: |
| 482 | return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; |
| 483 | } |
| 484 | |
| 485 | enum { |
| 486 | Opt_udev_path, Opt_readonly, Opt_force, Opt_err |
| 487 | }; |
| 488 | |
| 489 | static match_table_t tokens = { |
| 490 | {Opt_udev_path, "udev_path=%s"}, |
| 491 | {Opt_readonly, "readonly=%d"}, |
| 492 | {Opt_force, "force=%d"}, |
| 493 | {Opt_err, NULL} |
| 494 | }; |
| 495 | |
| 496 | static ssize_t iblock_set_configfs_dev_params(struct se_device *dev, |
| 497 | const char *page, ssize_t count) |
| 498 | { |
| 499 | struct iblock_dev *ib_dev = IBLOCK_DEV(dev); |
| 500 | char *orig, *ptr, *arg_p, *opts; |
| 501 | substring_t args[MAX_OPT_ARGS]; |
| 502 | int ret = 0, token; |
| 503 | unsigned long tmp_readonly; |
| 504 | |
| 505 | opts = kstrdup(page, GFP_KERNEL); |
| 506 | if (!opts) |
| 507 | return -ENOMEM; |
| 508 | |
| 509 | orig = opts; |
| 510 | |
| 511 | while ((ptr = strsep(&opts, ",\n")) != NULL) { |
| 512 | if (!*ptr) |
| 513 | continue; |
| 514 | |
| 515 | token = match_token(ptr, tokens, args); |
| 516 | switch (token) { |
| 517 | case Opt_udev_path: |
| 518 | if (ib_dev->ibd_bd) { |
| 519 | pr_err("Unable to set udev_path= while" |
| 520 | " ib_dev->ibd_bd exists\n"); |
| 521 | ret = -EEXIST; |
| 522 | goto out; |
| 523 | } |
| 524 | if (match_strlcpy(ib_dev->ibd_udev_path, &args[0], |
| 525 | SE_UDEV_PATH_LEN) == 0) { |
| 526 | ret = -EINVAL; |
| 527 | break; |
| 528 | } |
| 529 | pr_debug("IBLOCK: Referencing UDEV path: %s\n", |
| 530 | ib_dev->ibd_udev_path); |
| 531 | ib_dev->ibd_flags |= IBDF_HAS_UDEV_PATH; |
| 532 | break; |
| 533 | case Opt_readonly: |
| 534 | arg_p = match_strdup(&args[0]); |
| 535 | if (!arg_p) { |
| 536 | ret = -ENOMEM; |
| 537 | break; |
| 538 | } |
| 539 | ret = kstrtoul(arg_p, 0, &tmp_readonly); |
| 540 | kfree(arg_p); |
| 541 | if (ret < 0) { |
| 542 | pr_err("kstrtoul() failed for" |
| 543 | " readonly=\n"); |
| 544 | goto out; |
| 545 | } |
| 546 | ib_dev->ibd_readonly = tmp_readonly; |
| 547 | pr_debug("IBLOCK: readonly: %d\n", ib_dev->ibd_readonly); |
| 548 | break; |
| 549 | case Opt_force: |
| 550 | break; |
| 551 | default: |
| 552 | break; |
| 553 | } |
| 554 | } |
| 555 | |
| 556 | out: |
| 557 | kfree(orig); |
| 558 | return (!ret) ? count : ret; |
| 559 | } |
| 560 | |
| 561 | static ssize_t iblock_show_configfs_dev_params(struct se_device *dev, char *b) |
| 562 | { |
| 563 | struct iblock_dev *ib_dev = IBLOCK_DEV(dev); |
| 564 | struct block_device *bd = ib_dev->ibd_bd; |
| 565 | char buf[BDEVNAME_SIZE]; |
| 566 | ssize_t bl = 0; |
| 567 | |
| 568 | if (bd) |
| 569 | bl += sprintf(b + bl, "iBlock device: %s", |
| 570 | bdevname(bd, buf)); |
| 571 | if (ib_dev->ibd_flags & IBDF_HAS_UDEV_PATH) |
| 572 | bl += sprintf(b + bl, " UDEV PATH: %s", |
| 573 | ib_dev->ibd_udev_path); |
| 574 | bl += sprintf(b + bl, " readonly: %d\n", ib_dev->ibd_readonly); |
| 575 | |
| 576 | bl += sprintf(b + bl, " "); |
| 577 | if (bd) { |
| 578 | bl += sprintf(b + bl, "Major: %d Minor: %d %s\n", |
| 579 | MAJOR(bd->bd_dev), MINOR(bd->bd_dev), (!bd->bd_contains) ? |
| 580 | "" : (bd->bd_holder == ib_dev) ? |
| 581 | "CLAIMED: IBLOCK" : "CLAIMED: OS"); |
| 582 | } else { |
| 583 | bl += sprintf(b + bl, "Major: 0 Minor: 0\n"); |
| 584 | } |
| 585 | |
| 586 | return bl; |
| 587 | } |
| 588 | |
| 589 | static sense_reason_t |
| 590 | iblock_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents, |
| 591 | enum dma_data_direction data_direction) |
| 592 | { |
| 593 | struct se_device *dev = cmd->se_dev; |
| 594 | struct iblock_req *ibr; |
| 595 | struct bio *bio; |
| 596 | struct bio_list list; |
| 597 | struct scatterlist *sg; |
| 598 | u32 sg_num = sgl_nents; |
| 599 | sector_t block_lba; |
| 600 | unsigned bio_cnt; |
| 601 | int rw = 0; |
| 602 | int i; |
| 603 | |
| 604 | if (data_direction == DMA_TO_DEVICE) { |
| 605 | struct iblock_dev *ib_dev = IBLOCK_DEV(dev); |
| 606 | struct request_queue *q = bdev_get_queue(ib_dev->ibd_bd); |
| 607 | /* |
| 608 | * Force writethrough using WRITE_FUA if a volatile write cache |
| 609 | * is not enabled, or if initiator set the Force Unit Access bit. |
| 610 | */ |
| 611 | if (q->flush_flags & REQ_FUA) { |
| 612 | if (cmd->se_cmd_flags & SCF_FUA) |
| 613 | rw = WRITE_FUA; |
| 614 | else if (!(q->flush_flags & REQ_FLUSH)) |
| 615 | rw = WRITE_FUA; |
| 616 | else |
| 617 | rw = WRITE; |
| 618 | } else { |
| 619 | rw = WRITE; |
| 620 | } |
| 621 | } else { |
| 622 | rw = READ; |
| 623 | } |
| 624 | |
| 625 | /* |
| 626 | * Convert the blocksize advertised to the initiator to the 512 byte |
| 627 | * units unconditionally used by the Linux block layer. |
| 628 | */ |
| 629 | if (dev->dev_attrib.block_size == 4096) |
| 630 | block_lba = (cmd->t_task_lba << 3); |
| 631 | else if (dev->dev_attrib.block_size == 2048) |
| 632 | block_lba = (cmd->t_task_lba << 2); |
| 633 | else if (dev->dev_attrib.block_size == 1024) |
| 634 | block_lba = (cmd->t_task_lba << 1); |
| 635 | else if (dev->dev_attrib.block_size == 512) |
| 636 | block_lba = cmd->t_task_lba; |
| 637 | else { |
| 638 | pr_err("Unsupported SCSI -> BLOCK LBA conversion:" |
| 639 | " %u\n", dev->dev_attrib.block_size); |
| 640 | return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; |
| 641 | } |
| 642 | |
| 643 | ibr = kzalloc(sizeof(struct iblock_req), GFP_KERNEL); |
| 644 | if (!ibr) |
| 645 | goto fail; |
| 646 | cmd->priv = ibr; |
| 647 | |
| 648 | if (!sgl_nents) { |
| 649 | atomic_set(&ibr->pending, 1); |
| 650 | iblock_complete_cmd(cmd); |
| 651 | return 0; |
| 652 | } |
| 653 | |
| 654 | bio = iblock_get_bio(cmd, block_lba, sgl_nents); |
| 655 | if (!bio) |
| 656 | goto fail_free_ibr; |
| 657 | |
| 658 | bio_list_init(&list); |
| 659 | bio_list_add(&list, bio); |
| 660 | |
| 661 | atomic_set(&ibr->pending, 2); |
| 662 | bio_cnt = 1; |
| 663 | |
| 664 | for_each_sg(sgl, sg, sgl_nents, i) { |
| 665 | /* |
| 666 | * XXX: if the length the device accepts is shorter than the |
| 667 | * length of the S/G list entry this will cause and |
| 668 | * endless loop. Better hope no driver uses huge pages. |
| 669 | */ |
| 670 | while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset) |
| 671 | != sg->length) { |
| 672 | if (bio_cnt >= IBLOCK_MAX_BIO_PER_TASK) { |
| 673 | iblock_submit_bios(&list, rw); |
| 674 | bio_cnt = 0; |
| 675 | } |
| 676 | |
| 677 | bio = iblock_get_bio(cmd, block_lba, sg_num); |
| 678 | if (!bio) |
| 679 | goto fail_put_bios; |
| 680 | |
| 681 | atomic_inc(&ibr->pending); |
| 682 | bio_list_add(&list, bio); |
| 683 | bio_cnt++; |
| 684 | } |
| 685 | |
| 686 | /* Always in 512 byte units for Linux/Block */ |
| 687 | block_lba += sg->length >> IBLOCK_LBA_SHIFT; |
| 688 | sg_num--; |
| 689 | } |
| 690 | |
| 691 | iblock_submit_bios(&list, rw); |
| 692 | iblock_complete_cmd(cmd); |
| 693 | return 0; |
| 694 | |
| 695 | fail_put_bios: |
| 696 | while ((bio = bio_list_pop(&list))) |
| 697 | bio_put(bio); |
| 698 | fail_free_ibr: |
| 699 | kfree(ibr); |
| 700 | fail: |
| 701 | return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; |
| 702 | } |
| 703 | |
| 704 | static sector_t iblock_get_blocks(struct se_device *dev) |
| 705 | { |
| 706 | struct iblock_dev *ib_dev = IBLOCK_DEV(dev); |
| 707 | struct block_device *bd = ib_dev->ibd_bd; |
| 708 | struct request_queue *q = bdev_get_queue(bd); |
| 709 | |
| 710 | return iblock_emulate_read_cap_with_block_size(dev, bd, q); |
| 711 | } |
| 712 | |
| 713 | static sector_t iblock_get_alignment_offset_lbas(struct se_device *dev) |
| 714 | { |
| 715 | struct iblock_dev *ib_dev = IBLOCK_DEV(dev); |
| 716 | struct block_device *bd = ib_dev->ibd_bd; |
| 717 | int ret; |
| 718 | |
| 719 | ret = bdev_alignment_offset(bd); |
| 720 | if (ret == -1) |
| 721 | return 0; |
| 722 | |
| 723 | /* convert offset-bytes to offset-lbas */ |
| 724 | return ret / bdev_logical_block_size(bd); |
| 725 | } |
| 726 | |
| 727 | static unsigned int iblock_get_lbppbe(struct se_device *dev) |
| 728 | { |
| 729 | struct iblock_dev *ib_dev = IBLOCK_DEV(dev); |
| 730 | struct block_device *bd = ib_dev->ibd_bd; |
| 731 | int logs_per_phys = bdev_physical_block_size(bd) / bdev_logical_block_size(bd); |
| 732 | |
| 733 | return ilog2(logs_per_phys); |
| 734 | } |
| 735 | |
| 736 | static unsigned int iblock_get_io_min(struct se_device *dev) |
| 737 | { |
| 738 | struct iblock_dev *ib_dev = IBLOCK_DEV(dev); |
| 739 | struct block_device *bd = ib_dev->ibd_bd; |
| 740 | |
| 741 | return bdev_io_min(bd); |
| 742 | } |
| 743 | |
| 744 | static unsigned int iblock_get_io_opt(struct se_device *dev) |
| 745 | { |
| 746 | struct iblock_dev *ib_dev = IBLOCK_DEV(dev); |
| 747 | struct block_device *bd = ib_dev->ibd_bd; |
| 748 | |
| 749 | return bdev_io_opt(bd); |
| 750 | } |
| 751 | |
| 752 | static struct sbc_ops iblock_sbc_ops = { |
| 753 | .execute_rw = iblock_execute_rw, |
| 754 | .execute_sync_cache = iblock_execute_sync_cache, |
| 755 | .execute_write_same = iblock_execute_write_same, |
| 756 | .execute_write_same_unmap = iblock_execute_write_same_unmap, |
| 757 | .execute_unmap = iblock_execute_unmap, |
| 758 | }; |
| 759 | |
| 760 | static sense_reason_t |
| 761 | iblock_parse_cdb(struct se_cmd *cmd) |
| 762 | { |
| 763 | return sbc_parse_cdb(cmd, &iblock_sbc_ops); |
| 764 | } |
| 765 | |
| 766 | bool iblock_get_write_cache(struct se_device *dev) |
| 767 | { |
| 768 | struct iblock_dev *ib_dev = IBLOCK_DEV(dev); |
| 769 | struct block_device *bd = ib_dev->ibd_bd; |
| 770 | struct request_queue *q = bdev_get_queue(bd); |
| 771 | |
| 772 | return q->flush_flags & REQ_FLUSH; |
| 773 | } |
| 774 | |
| 775 | static struct se_subsystem_api iblock_template = { |
| 776 | .name = "iblock", |
| 777 | .inquiry_prod = "IBLOCK", |
| 778 | .inquiry_rev = IBLOCK_VERSION, |
| 779 | .owner = THIS_MODULE, |
| 780 | .transport_type = TRANSPORT_PLUGIN_VHBA_PDEV, |
| 781 | .attach_hba = iblock_attach_hba, |
| 782 | .detach_hba = iblock_detach_hba, |
| 783 | .alloc_device = iblock_alloc_device, |
| 784 | .configure_device = iblock_configure_device, |
| 785 | .free_device = iblock_free_device, |
| 786 | .parse_cdb = iblock_parse_cdb, |
| 787 | .set_configfs_dev_params = iblock_set_configfs_dev_params, |
| 788 | .show_configfs_dev_params = iblock_show_configfs_dev_params, |
| 789 | .get_device_type = sbc_get_device_type, |
| 790 | .get_blocks = iblock_get_blocks, |
| 791 | .get_alignment_offset_lbas = iblock_get_alignment_offset_lbas, |
| 792 | .get_lbppbe = iblock_get_lbppbe, |
| 793 | .get_io_min = iblock_get_io_min, |
| 794 | .get_io_opt = iblock_get_io_opt, |
| 795 | .get_write_cache = iblock_get_write_cache, |
| 796 | }; |
| 797 | |
| 798 | static int __init iblock_module_init(void) |
| 799 | { |
| 800 | return transport_subsystem_register(&iblock_template); |
| 801 | } |
| 802 | |
| 803 | static void __exit iblock_module_exit(void) |
| 804 | { |
| 805 | transport_subsystem_release(&iblock_template); |
| 806 | } |
| 807 | |
| 808 | MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin"); |
| 809 | MODULE_AUTHOR("nab@Linux-iSCSI.org"); |
| 810 | MODULE_LICENSE("GPL"); |
| 811 | |
| 812 | module_init(iblock_module_init); |
| 813 | module_exit(iblock_module_exit); |