1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Squashfs - a compressed read only filesystem for Linux 4 * 5 * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008 6 * Phillip Lougher <phillip@squashfs.org.uk> 7 * 8 * super.c 9 */ 10 11 /* 12 * This file implements code to read the superblock, read and initialise 13 * in-memory structures at mount time, and all the VFS glue code to register 14 * the filesystem. 15 */ 16 17 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 18 19 #include <linux/blkdev.h> 20 #include <linux/fs.h> 21 #include <linux/fs_context.h> 22 #include <linux/fs_parser.h> 23 #include <linux/vfs.h> 24 #include <linux/slab.h> 25 #include <linux/mutex.h> 26 #include <linux/seq_file.h> 27 #include <linux/pagemap.h> 28 #include <linux/init.h> 29 #include <linux/module.h> 30 #include <linux/magic.h> 31 #include <linux/xattr.h> 32 33 #include "squashfs_fs.h" 34 #include "squashfs_fs_sb.h" 35 #include "squashfs_fs_i.h" 36 #include "squashfs.h" 37 #include "decompressor.h" 38 #include "xattr.h" 39 40 static struct file_system_type squashfs_fs_type; 41 static const struct super_operations squashfs_super_ops; 42 43 enum Opt_errors { 44 Opt_errors_continue, 45 Opt_errors_panic, 46 }; 47 48 enum squashfs_param { 49 Opt_errors, 50 Opt_threads, 51 }; 52 53 struct squashfs_mount_opts { 54 enum Opt_errors errors; 55 const struct squashfs_decompressor_thread_ops *thread_ops; 56 int thread_num; 57 }; 58 59 static const struct constant_table squashfs_param_errors[] = { 60 {"continue", Opt_errors_continue }, 61 {"panic", Opt_errors_panic }, 62 {} 63 }; 64 65 static const struct fs_parameter_spec squashfs_fs_parameters[] = { 66 fsparam_enum("errors", Opt_errors, squashfs_param_errors), 67 fsparam_string("threads", Opt_threads), 68 {} 69 }; 70 71 72 static int squashfs_parse_param_threads_str(const char *str, struct squashfs_mount_opts *opts) 73 { 74 #ifdef CONFIG_SQUASHFS_CHOICE_DECOMP_BY_MOUNT 75 if (strcmp(str, "single") == 0) { 76 opts->thread_ops = &squashfs_decompressor_single; 77 return 0; 78 } 79 if (strcmp(str, "multi") == 0) { 80 opts->thread_ops = &squashfs_decompressor_multi; 81 return 0; 82 } 83 if (strcmp(str, "percpu") == 0) { 84 opts->thread_ops = &squashfs_decompressor_percpu; 85 return 0; 86 } 87 #endif 88 return -EINVAL; 89 } 90 91 static int squashfs_parse_param_threads_num(const char *str, struct squashfs_mount_opts *opts) 92 { 93 #ifdef CONFIG_SQUASHFS_MOUNT_DECOMP_THREADS 94 int ret; 95 unsigned long num; 96 97 ret = kstrtoul(str, 0, &num); 98 if (ret != 0) 99 return -EINVAL; 100 if (num > 1) { 101 opts->thread_ops = &squashfs_decompressor_multi; 102 if (num > opts->thread_ops->max_decompressors()) 103 return -EINVAL; 104 opts->thread_num = (int)num; 105 return 0; 106 } 107 #ifdef CONFIG_SQUASHFS_DECOMP_SINGLE 108 if (num == 1) { 109 opts->thread_ops = &squashfs_decompressor_single; 110 opts->thread_num = 1; 111 return 0; 112 } 113 #endif 114 #endif /* !CONFIG_SQUASHFS_MOUNT_DECOMP_THREADS */ 115 return -EINVAL; 116 } 117 118 static int squashfs_parse_param_threads(const char *str, struct squashfs_mount_opts *opts) 119 { 120 int ret = squashfs_parse_param_threads_str(str, opts); 121 122 if (ret == 0) 123 return ret; 124 return squashfs_parse_param_threads_num(str, opts); 125 } 126 127 static int squashfs_parse_param(struct fs_context *fc, struct fs_parameter *param) 128 { 129 struct squashfs_mount_opts *opts = fc->fs_private; 130 struct fs_parse_result result; 131 int opt; 132 133 opt = fs_parse(fc, squashfs_fs_parameters, param, &result); 134 if (opt < 0) 135 return opt; 136 137 switch (opt) { 138 case Opt_errors: 139 opts->errors = result.uint_32; 140 break; 141 case Opt_threads: 142 if (squashfs_parse_param_threads(param->string, opts) != 0) 143 return -EINVAL; 144 break; 145 default: 146 return -EINVAL; 147 } 148 149 return 0; 150 } 151 152 static const struct squashfs_decompressor *supported_squashfs_filesystem( 153 struct fs_context *fc, 154 short major, short minor, short id) 155 { 156 const struct squashfs_decompressor *decompressor; 157 158 if (major < SQUASHFS_MAJOR) { 159 errorf(fc, "Major/Minor mismatch, older Squashfs %d.%d " 160 "filesystems are unsupported", major, minor); 161 return NULL; 162 } else if (major > SQUASHFS_MAJOR || minor > SQUASHFS_MINOR) { 163 errorf(fc, "Major/Minor mismatch, trying to mount newer " 164 "%d.%d filesystem", major, minor); 165 errorf(fc, "Please update your kernel"); 166 return NULL; 167 } 168 169 decompressor = squashfs_lookup_decompressor(id); 170 if (!decompressor->supported) { 171 errorf(fc, "Filesystem uses \"%s\" compression. This is not supported", 172 decompressor->name); 173 return NULL; 174 } 175 176 return decompressor; 177 } 178 179 180 static int squashfs_fill_super(struct super_block *sb, struct fs_context *fc) 181 { 182 struct squashfs_mount_opts *opts = fc->fs_private; 183 struct squashfs_sb_info *msblk; 184 struct squashfs_super_block *sblk = NULL; 185 struct inode *root; 186 long long root_inode; 187 unsigned short flags; 188 unsigned int fragments; 189 u64 lookup_table_start, xattr_id_table_start, next_table; 190 int err; 191 192 TRACE("Entered squashfs_fill_superblock\n"); 193 194 sb->s_fs_info = kzalloc(sizeof(*msblk), GFP_KERNEL); 195 if (sb->s_fs_info == NULL) { 196 ERROR("Failed to allocate squashfs_sb_info\n"); 197 return -ENOMEM; 198 } 199 msblk = sb->s_fs_info; 200 msblk->thread_ops = opts->thread_ops; 201 202 msblk->panic_on_errors = (opts->errors == Opt_errors_panic); 203 204 msblk->devblksize = sb_min_blocksize(sb, SQUASHFS_DEVBLK_SIZE); 205 if (!msblk->devblksize) { 206 errorf(fc, "squashfs: unable to set blocksize\n"); 207 return -EINVAL; 208 } 209 210 msblk->devblksize_log2 = ffz(~msblk->devblksize); 211 212 mutex_init(&msblk->meta_index_mutex); 213 214 /* 215 * msblk->bytes_used is checked in squashfs_read_table to ensure reads 216 * are not beyond filesystem end. But as we're using 217 * squashfs_read_table here to read the superblock (including the value 218 * of bytes_used) we need to set it to an initial sensible dummy value 219 */ 220 msblk->bytes_used = sizeof(*sblk); 221 sblk = squashfs_read_table(sb, SQUASHFS_START, sizeof(*sblk)); 222 223 if (IS_ERR(sblk)) { 224 errorf(fc, "unable to read squashfs_super_block"); 225 err = PTR_ERR(sblk); 226 sblk = NULL; 227 goto failed_mount; 228 } 229 230 err = -EINVAL; 231 232 /* Check it is a SQUASHFS superblock */ 233 sb->s_magic = le32_to_cpu(sblk->s_magic); 234 if (sb->s_magic != SQUASHFS_MAGIC) { 235 if (!(fc->sb_flags & SB_SILENT)) 236 errorf(fc, "Can't find a SQUASHFS superblock on %pg", 237 sb->s_bdev); 238 goto failed_mount; 239 } 240 241 if (opts->thread_num == 0) { 242 msblk->max_thread_num = msblk->thread_ops->max_decompressors(); 243 } else { 244 msblk->max_thread_num = opts->thread_num; 245 } 246 247 /* Check the MAJOR & MINOR versions and lookup compression type */ 248 msblk->decompressor = supported_squashfs_filesystem( 249 fc, 250 le16_to_cpu(sblk->s_major), 251 le16_to_cpu(sblk->s_minor), 252 le16_to_cpu(sblk->compression)); 253 if (msblk->decompressor == NULL) 254 goto failed_mount; 255 256 /* Check the filesystem does not extend beyond the end of the 257 block device */ 258 msblk->bytes_used = le64_to_cpu(sblk->bytes_used); 259 if (msblk->bytes_used < 0 || 260 msblk->bytes_used > bdev_nr_bytes(sb->s_bdev)) 261 goto failed_mount; 262 263 /* Check block size for sanity */ 264 msblk->block_size = le32_to_cpu(sblk->block_size); 265 if (msblk->block_size > SQUASHFS_FILE_MAX_SIZE) 266 goto insanity; 267 268 /* 269 * Check the system page size is not larger than the filesystem 270 * block size (by default 128K). This is currently not supported. 271 */ 272 if (PAGE_SIZE > msblk->block_size) { 273 errorf(fc, "Page size > filesystem block size (%d). This is " 274 "currently not supported!", msblk->block_size); 275 goto failed_mount; 276 } 277 278 /* Check block log for sanity */ 279 msblk->block_log = le16_to_cpu(sblk->block_log); 280 if (msblk->block_log > SQUASHFS_FILE_MAX_LOG) 281 goto failed_mount; 282 283 /* Check that block_size and block_log match */ 284 if (msblk->block_size != (1 << msblk->block_log)) 285 goto insanity; 286 287 /* Check the root inode for sanity */ 288 root_inode = le64_to_cpu(sblk->root_inode); 289 if (SQUASHFS_INODE_OFFSET(root_inode) > SQUASHFS_METADATA_SIZE) 290 goto insanity; 291 292 msblk->inode_table = le64_to_cpu(sblk->inode_table_start); 293 msblk->directory_table = le64_to_cpu(sblk->directory_table_start); 294 msblk->inodes = le32_to_cpu(sblk->inodes); 295 msblk->fragments = le32_to_cpu(sblk->fragments); 296 msblk->ids = le16_to_cpu(sblk->no_ids); 297 flags = le16_to_cpu(sblk->flags); 298 299 TRACE("Found valid superblock on %pg\n", sb->s_bdev); 300 TRACE("Inodes are %scompressed\n", SQUASHFS_UNCOMPRESSED_INODES(flags) 301 ? "un" : ""); 302 TRACE("Data is %scompressed\n", SQUASHFS_UNCOMPRESSED_DATA(flags) 303 ? "un" : ""); 304 TRACE("Filesystem size %lld bytes\n", msblk->bytes_used); 305 TRACE("Block size %d\n", msblk->block_size); 306 TRACE("Number of inodes %d\n", msblk->inodes); 307 TRACE("Number of fragments %d\n", msblk->fragments); 308 TRACE("Number of ids %d\n", msblk->ids); 309 TRACE("sblk->inode_table_start %llx\n", msblk->inode_table); 310 TRACE("sblk->directory_table_start %llx\n", msblk->directory_table); 311 TRACE("sblk->fragment_table_start %llx\n", 312 (u64) le64_to_cpu(sblk->fragment_table_start)); 313 TRACE("sblk->id_table_start %llx\n", 314 (u64) le64_to_cpu(sblk->id_table_start)); 315 316 sb->s_maxbytes = MAX_LFS_FILESIZE; 317 sb->s_time_min = 0; 318 sb->s_time_max = U32_MAX; 319 sb->s_flags |= SB_RDONLY; 320 sb->s_op = &squashfs_super_ops; 321 322 msblk->block_cache = squashfs_cache_init("metadata", 323 SQUASHFS_CACHED_BLKS, SQUASHFS_METADATA_SIZE); 324 if (IS_ERR(msblk->block_cache)) { 325 err = PTR_ERR(msblk->block_cache); 326 goto failed_mount; 327 } 328 329 /* Allocate read_page block */ 330 msblk->read_page = squashfs_cache_init("data", 331 SQUASHFS_READ_PAGES, msblk->block_size); 332 if (IS_ERR(msblk->read_page)) { 333 errorf(fc, "Failed to allocate read_page block"); 334 err = PTR_ERR(msblk->read_page); 335 goto failed_mount; 336 } 337 338 if (msblk->devblksize == PAGE_SIZE) { 339 struct inode *cache = new_inode(sb); 340 341 if (cache == NULL) { 342 err = -ENOMEM; 343 goto failed_mount; 344 } 345 346 set_nlink(cache, 1); 347 cache->i_size = OFFSET_MAX; 348 mapping_set_gfp_mask(cache->i_mapping, GFP_NOFS); 349 350 msblk->cache_mapping = cache->i_mapping; 351 } 352 353 msblk->stream = squashfs_decompressor_setup(sb, flags); 354 if (IS_ERR(msblk->stream)) { 355 err = PTR_ERR(msblk->stream); 356 msblk->stream = NULL; 357 goto insanity; 358 } 359 360 /* Handle xattrs */ 361 sb->s_xattr = squashfs_xattr_handlers; 362 xattr_id_table_start = le64_to_cpu(sblk->xattr_id_table_start); 363 if (xattr_id_table_start == SQUASHFS_INVALID_BLK) { 364 next_table = msblk->bytes_used; 365 goto allocate_id_index_table; 366 } 367 368 /* Allocate and read xattr id lookup table */ 369 msblk->xattr_id_table = squashfs_read_xattr_id_table(sb, 370 xattr_id_table_start, &msblk->xattr_table, &msblk->xattr_ids); 371 if (IS_ERR(msblk->xattr_id_table)) { 372 errorf(fc, "unable to read xattr id index table"); 373 err = PTR_ERR(msblk->xattr_id_table); 374 msblk->xattr_id_table = NULL; 375 if (err != -ENOTSUPP) 376 goto failed_mount; 377 } 378 next_table = msblk->xattr_table; 379 380 allocate_id_index_table: 381 /* Allocate and read id index table */ 382 msblk->id_table = squashfs_read_id_index_table(sb, 383 le64_to_cpu(sblk->id_table_start), next_table, msblk->ids); 384 if (IS_ERR(msblk->id_table)) { 385 errorf(fc, "unable to read id index table"); 386 err = PTR_ERR(msblk->id_table); 387 msblk->id_table = NULL; 388 goto failed_mount; 389 } 390 next_table = le64_to_cpu(msblk->id_table[0]); 391 392 /* Handle inode lookup table */ 393 lookup_table_start = le64_to_cpu(sblk->lookup_table_start); 394 if (lookup_table_start == SQUASHFS_INVALID_BLK) 395 goto handle_fragments; 396 397 /* Allocate and read inode lookup table */ 398 msblk->inode_lookup_table = squashfs_read_inode_lookup_table(sb, 399 lookup_table_start, next_table, msblk->inodes); 400 if (IS_ERR(msblk->inode_lookup_table)) { 401 errorf(fc, "unable to read inode lookup table"); 402 err = PTR_ERR(msblk->inode_lookup_table); 403 msblk->inode_lookup_table = NULL; 404 goto failed_mount; 405 } 406 next_table = le64_to_cpu(msblk->inode_lookup_table[0]); 407 408 sb->s_export_op = &squashfs_export_ops; 409 410 handle_fragments: 411 fragments = msblk->fragments; 412 if (fragments == 0) 413 goto check_directory_table; 414 415 msblk->fragment_cache = squashfs_cache_init("fragment", 416 min(SQUASHFS_CACHED_FRAGMENTS, fragments), msblk->block_size); 417 if (IS_ERR(msblk->fragment_cache)) { 418 err = PTR_ERR(msblk->fragment_cache); 419 goto failed_mount; 420 } 421 422 /* Allocate and read fragment index table */ 423 msblk->fragment_index = squashfs_read_fragment_index_table(sb, 424 le64_to_cpu(sblk->fragment_table_start), next_table, fragments); 425 if (IS_ERR(msblk->fragment_index)) { 426 errorf(fc, "unable to read fragment index table"); 427 err = PTR_ERR(msblk->fragment_index); 428 msblk->fragment_index = NULL; 429 goto failed_mount; 430 } 431 next_table = le64_to_cpu(msblk->fragment_index[0]); 432 433 check_directory_table: 434 /* Sanity check directory_table */ 435 if (msblk->directory_table > next_table) { 436 err = -EINVAL; 437 goto insanity; 438 } 439 440 /* Sanity check inode_table */ 441 if (msblk->inode_table >= msblk->directory_table) { 442 err = -EINVAL; 443 goto insanity; 444 } 445 446 /* allocate root */ 447 root = new_inode(sb); 448 if (!root) { 449 err = -ENOMEM; 450 goto failed_mount; 451 } 452 453 err = squashfs_read_inode(root, root_inode); 454 if (err) { 455 make_bad_inode(root); 456 iput(root); 457 goto failed_mount; 458 } 459 insert_inode_hash(root); 460 461 sb->s_root = d_make_root(root); 462 if (sb->s_root == NULL) { 463 ERROR("Root inode create failed\n"); 464 err = -ENOMEM; 465 goto failed_mount; 466 } 467 468 TRACE("Leaving squashfs_fill_super\n"); 469 kfree(sblk); 470 return 0; 471 472 insanity: 473 errorf(fc, "squashfs image failed sanity check"); 474 failed_mount: 475 squashfs_cache_delete(msblk->block_cache); 476 squashfs_cache_delete(msblk->fragment_cache); 477 squashfs_cache_delete(msblk->read_page); 478 if (msblk->cache_mapping) 479 iput(msblk->cache_mapping->host); 480 msblk->thread_ops->destroy(msblk); 481 kfree(msblk->inode_lookup_table); 482 kfree(msblk->fragment_index); 483 kfree(msblk->id_table); 484 kfree(msblk->xattr_id_table); 485 kfree(sb->s_fs_info); 486 sb->s_fs_info = NULL; 487 kfree(sblk); 488 return err; 489 } 490 491 static int squashfs_get_tree(struct fs_context *fc) 492 { 493 return get_tree_bdev(fc, squashfs_fill_super); 494 } 495 496 static int squashfs_reconfigure(struct fs_context *fc) 497 { 498 struct super_block *sb = fc->root->d_sb; 499 struct squashfs_sb_info *msblk = sb->s_fs_info; 500 struct squashfs_mount_opts *opts = fc->fs_private; 501 502 sync_filesystem(fc->root->d_sb); 503 fc->sb_flags |= SB_RDONLY; 504 505 msblk->panic_on_errors = (opts->errors == Opt_errors_panic); 506 507 return 0; 508 } 509 510 static void squashfs_free_fs_context(struct fs_context *fc) 511 { 512 kfree(fc->fs_private); 513 } 514 515 static const struct fs_context_operations squashfs_context_ops = { 516 .get_tree = squashfs_get_tree, 517 .free = squashfs_free_fs_context, 518 .parse_param = squashfs_parse_param, 519 .reconfigure = squashfs_reconfigure, 520 }; 521 522 static int squashfs_show_options(struct seq_file *s, struct dentry *root) 523 { 524 struct super_block *sb = root->d_sb; 525 struct squashfs_sb_info *msblk = sb->s_fs_info; 526 527 if (msblk->panic_on_errors) 528 seq_puts(s, ",errors=panic"); 529 else 530 seq_puts(s, ",errors=continue"); 531 532 #ifdef CONFIG_SQUASHFS_CHOICE_DECOMP_BY_MOUNT 533 if (msblk->thread_ops == &squashfs_decompressor_single) { 534 seq_puts(s, ",threads=single"); 535 return 0; 536 } 537 if (msblk->thread_ops == &squashfs_decompressor_percpu) { 538 seq_puts(s, ",threads=percpu"); 539 return 0; 540 } 541 #endif 542 #ifdef CONFIG_SQUASHFS_MOUNT_DECOMP_THREADS 543 seq_printf(s, ",threads=%d", msblk->max_thread_num); 544 #endif 545 return 0; 546 } 547 548 static int squashfs_init_fs_context(struct fs_context *fc) 549 { 550 struct squashfs_mount_opts *opts; 551 552 opts = kzalloc(sizeof(*opts), GFP_KERNEL); 553 if (!opts) 554 return -ENOMEM; 555 556 #ifdef CONFIG_SQUASHFS_DECOMP_SINGLE 557 opts->thread_ops = &squashfs_decompressor_single; 558 #elif defined(CONFIG_SQUASHFS_DECOMP_MULTI) 559 opts->thread_ops = &squashfs_decompressor_multi; 560 #elif defined(CONFIG_SQUASHFS_DECOMP_MULTI_PERCPU) 561 opts->thread_ops = &squashfs_decompressor_percpu; 562 #else 563 #error "fail: unknown squashfs decompression thread mode?" 564 #endif 565 opts->thread_num = 0; 566 fc->fs_private = opts; 567 fc->ops = &squashfs_context_ops; 568 return 0; 569 } 570 571 static int squashfs_statfs(struct dentry *dentry, struct kstatfs *buf) 572 { 573 struct squashfs_sb_info *msblk = dentry->d_sb->s_fs_info; 574 u64 id = huge_encode_dev(dentry->d_sb->s_bdev->bd_dev); 575 576 TRACE("Entered squashfs_statfs\n"); 577 578 buf->f_type = SQUASHFS_MAGIC; 579 buf->f_bsize = msblk->block_size; 580 buf->f_blocks = ((msblk->bytes_used - 1) >> msblk->block_log) + 1; 581 buf->f_bfree = buf->f_bavail = 0; 582 buf->f_files = msblk->inodes; 583 buf->f_ffree = 0; 584 buf->f_namelen = SQUASHFS_NAME_LEN; 585 buf->f_fsid = u64_to_fsid(id); 586 587 return 0; 588 } 589 590 591 static void squashfs_put_super(struct super_block *sb) 592 { 593 if (sb->s_fs_info) { 594 struct squashfs_sb_info *sbi = sb->s_fs_info; 595 squashfs_cache_delete(sbi->block_cache); 596 squashfs_cache_delete(sbi->fragment_cache); 597 squashfs_cache_delete(sbi->read_page); 598 if (sbi->cache_mapping) 599 iput(sbi->cache_mapping->host); 600 sbi->thread_ops->destroy(sbi); 601 kfree(sbi->id_table); 602 kfree(sbi->fragment_index); 603 kfree(sbi->meta_index); 604 kfree(sbi->inode_lookup_table); 605 kfree(sbi->xattr_id_table); 606 kfree(sb->s_fs_info); 607 sb->s_fs_info = NULL; 608 } 609 } 610 611 static struct kmem_cache *squashfs_inode_cachep; 612 613 614 static void init_once(void *foo) 615 { 616 struct squashfs_inode_info *ei = foo; 617 618 inode_init_once(&ei->vfs_inode); 619 } 620 621 622 static int __init init_inodecache(void) 623 { 624 squashfs_inode_cachep = kmem_cache_create("squashfs_inode_cache", 625 sizeof(struct squashfs_inode_info), 0, 626 SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|SLAB_ACCOUNT, 627 init_once); 628 629 return squashfs_inode_cachep ? 0 : -ENOMEM; 630 } 631 632 633 static void destroy_inodecache(void) 634 { 635 /* 636 * Make sure all delayed rcu free inodes are flushed before we 637 * destroy cache. 638 */ 639 rcu_barrier(); 640 kmem_cache_destroy(squashfs_inode_cachep); 641 } 642 643 644 static int __init init_squashfs_fs(void) 645 { 646 int err = init_inodecache(); 647 648 if (err) 649 return err; 650 651 err = register_filesystem(&squashfs_fs_type); 652 if (err) { 653 destroy_inodecache(); 654 return err; 655 } 656 657 pr_info("version 4.0 (2009/01/31) Phillip Lougher\n"); 658 659 return 0; 660 } 661 662 663 static void __exit exit_squashfs_fs(void) 664 { 665 unregister_filesystem(&squashfs_fs_type); 666 destroy_inodecache(); 667 } 668 669 670 static struct inode *squashfs_alloc_inode(struct super_block *sb) 671 { 672 struct squashfs_inode_info *ei = 673 alloc_inode_sb(sb, squashfs_inode_cachep, GFP_KERNEL); 674 675 return ei ? &ei->vfs_inode : NULL; 676 } 677 678 679 static void squashfs_free_inode(struct inode *inode) 680 { 681 kmem_cache_free(squashfs_inode_cachep, squashfs_i(inode)); 682 } 683 684 static struct file_system_type squashfs_fs_type = { 685 .owner = THIS_MODULE, 686 .name = "squashfs", 687 .init_fs_context = squashfs_init_fs_context, 688 .parameters = squashfs_fs_parameters, 689 .kill_sb = kill_block_super, 690 .fs_flags = FS_REQUIRES_DEV | FS_ALLOW_IDMAP, 691 }; 692 MODULE_ALIAS_FS("squashfs"); 693 694 static const struct super_operations squashfs_super_ops = { 695 .alloc_inode = squashfs_alloc_inode, 696 .free_inode = squashfs_free_inode, 697 .statfs = squashfs_statfs, 698 .put_super = squashfs_put_super, 699 .show_options = squashfs_show_options, 700 }; 701 702 module_init(init_squashfs_fs); 703 module_exit(exit_squashfs_fs); 704 MODULE_DESCRIPTION("squashfs 4.0, a compressed read-only filesystem"); 705 MODULE_AUTHOR("Phillip Lougher <phillip@squashfs.org.uk>"); 706 MODULE_LICENSE("GPL"); 707