| 1 | /* |
| 2 | * Compressed rom filesystem for Linux. |
| 3 | * |
| 4 | * Copyright (C) 1999 Linus Torvalds. |
| 5 | * |
| 6 | * This file is released under the GPL. |
| 7 | */ |
| 8 | |
| 9 | /* |
| 10 | * These are the VFS interfaces to the compressed rom filesystem. |
| 11 | * The actual compression is based on zlib, see the other files. |
| 12 | */ |
| 13 | |
| 14 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| 15 | |
| 16 | #include <linux/module.h> |
| 17 | #include <linux/fs.h> |
| 18 | #include <linux/pagemap.h> |
| 19 | #include <linux/init.h> |
| 20 | #include <linux/string.h> |
| 21 | #include <linux/blkdev.h> |
| 22 | #include <linux/slab.h> |
| 23 | #include <linux/vfs.h> |
| 24 | #include <linux/mutex.h> |
| 25 | #include <uapi/linux/cramfs_fs.h> |
| 26 | #include <linux/uaccess.h> |
| 27 | |
| 28 | #include "internal.h" |
| 29 | |
| 30 | /* |
| 31 | * cramfs super-block data in memory |
| 32 | */ |
| 33 | struct cramfs_sb_info { |
| 34 | unsigned long magic; |
| 35 | unsigned long size; |
| 36 | unsigned long blocks; |
| 37 | unsigned long files; |
| 38 | unsigned long flags; |
| 39 | }; |
| 40 | |
| 41 | static inline struct cramfs_sb_info *CRAMFS_SB(struct super_block *sb) |
| 42 | { |
| 43 | return sb->s_fs_info; |
| 44 | } |
| 45 | |
| 46 | static const struct super_operations cramfs_ops; |
| 47 | static const struct inode_operations cramfs_dir_inode_operations; |
| 48 | static const struct file_operations cramfs_directory_operations; |
| 49 | static const struct address_space_operations cramfs_aops; |
| 50 | |
| 51 | static DEFINE_MUTEX(read_mutex); |
| 52 | |
| 53 | |
| 54 | /* These macros may change in future, to provide better st_ino semantics. */ |
| 55 | #define OFFSET(x) ((x)->i_ino) |
| 56 | |
| 57 | static unsigned long cramino(const struct cramfs_inode *cino, unsigned int offset) |
| 58 | { |
| 59 | if (!cino->offset) |
| 60 | return offset + 1; |
| 61 | if (!cino->size) |
| 62 | return offset + 1; |
| 63 | |
| 64 | /* |
| 65 | * The file mode test fixes buggy mkcramfs implementations where |
| 66 | * cramfs_inode->offset is set to a non zero value for entries |
| 67 | * which did not contain data, like devices node and fifos. |
| 68 | */ |
| 69 | switch (cino->mode & S_IFMT) { |
| 70 | case S_IFREG: |
| 71 | case S_IFDIR: |
| 72 | case S_IFLNK: |
| 73 | return cino->offset << 2; |
| 74 | default: |
| 75 | break; |
| 76 | } |
| 77 | return offset + 1; |
| 78 | } |
| 79 | |
| 80 | static struct inode *get_cramfs_inode(struct super_block *sb, |
| 81 | const struct cramfs_inode *cramfs_inode, unsigned int offset) |
| 82 | { |
| 83 | struct inode *inode; |
| 84 | static struct timespec zerotime; |
| 85 | |
| 86 | inode = iget_locked(sb, cramino(cramfs_inode, offset)); |
| 87 | if (!inode) |
| 88 | return ERR_PTR(-ENOMEM); |
| 89 | if (!(inode->i_state & I_NEW)) |
| 90 | return inode; |
| 91 | |
| 92 | switch (cramfs_inode->mode & S_IFMT) { |
| 93 | case S_IFREG: |
| 94 | inode->i_fop = &generic_ro_fops; |
| 95 | inode->i_data.a_ops = &cramfs_aops; |
| 96 | break; |
| 97 | case S_IFDIR: |
| 98 | inode->i_op = &cramfs_dir_inode_operations; |
| 99 | inode->i_fop = &cramfs_directory_operations; |
| 100 | break; |
| 101 | case S_IFLNK: |
| 102 | inode->i_op = &page_symlink_inode_operations; |
| 103 | inode_nohighmem(inode); |
| 104 | inode->i_data.a_ops = &cramfs_aops; |
| 105 | break; |
| 106 | default: |
| 107 | init_special_inode(inode, cramfs_inode->mode, |
| 108 | old_decode_dev(cramfs_inode->size)); |
| 109 | } |
| 110 | |
| 111 | inode->i_mode = cramfs_inode->mode; |
| 112 | i_uid_write(inode, cramfs_inode->uid); |
| 113 | i_gid_write(inode, cramfs_inode->gid); |
| 114 | |
| 115 | /* if the lower 2 bits are zero, the inode contains data */ |
| 116 | if (!(inode->i_ino & 3)) { |
| 117 | inode->i_size = cramfs_inode->size; |
| 118 | inode->i_blocks = (cramfs_inode->size - 1) / 512 + 1; |
| 119 | } |
| 120 | |
| 121 | /* Struct copy intentional */ |
| 122 | inode->i_mtime = inode->i_atime = inode->i_ctime = zerotime; |
| 123 | /* inode->i_nlink is left 1 - arguably wrong for directories, |
| 124 | but it's the best we can do without reading the directory |
| 125 | contents. 1 yields the right result in GNU find, even |
| 126 | without -noleaf option. */ |
| 127 | |
| 128 | unlock_new_inode(inode); |
| 129 | |
| 130 | return inode; |
| 131 | } |
| 132 | |
| 133 | /* |
| 134 | * We have our own block cache: don't fill up the buffer cache |
| 135 | * with the rom-image, because the way the filesystem is set |
| 136 | * up the accesses should be fairly regular and cached in the |
| 137 | * page cache and dentry tree anyway.. |
| 138 | * |
| 139 | * This also acts as a way to guarantee contiguous areas of up to |
| 140 | * BLKS_PER_BUF*PAGE_SIZE, so that the caller doesn't need to |
| 141 | * worry about end-of-buffer issues even when decompressing a full |
| 142 | * page cache. |
| 143 | */ |
| 144 | #define READ_BUFFERS (2) |
| 145 | /* NEXT_BUFFER(): Loop over [0..(READ_BUFFERS-1)]. */ |
| 146 | #define NEXT_BUFFER(_ix) ((_ix) ^ 1) |
| 147 | |
| 148 | /* |
| 149 | * BLKS_PER_BUF_SHIFT should be at least 2 to allow for "compressed" |
| 150 | * data that takes up more space than the original and with unlucky |
| 151 | * alignment. |
| 152 | */ |
| 153 | #define BLKS_PER_BUF_SHIFT (2) |
| 154 | #define BLKS_PER_BUF (1 << BLKS_PER_BUF_SHIFT) |
| 155 | #define BUFFER_SIZE (BLKS_PER_BUF*PAGE_SIZE) |
| 156 | |
| 157 | static unsigned char read_buffers[READ_BUFFERS][BUFFER_SIZE]; |
| 158 | static unsigned buffer_blocknr[READ_BUFFERS]; |
| 159 | static struct super_block *buffer_dev[READ_BUFFERS]; |
| 160 | static int next_buffer; |
| 161 | |
| 162 | /* |
| 163 | * Returns a pointer to a buffer containing at least LEN bytes of |
| 164 | * filesystem starting at byte offset OFFSET into the filesystem. |
| 165 | */ |
| 166 | static void *cramfs_read(struct super_block *sb, unsigned int offset, unsigned int len) |
| 167 | { |
| 168 | struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping; |
| 169 | struct page *pages[BLKS_PER_BUF]; |
| 170 | unsigned i, blocknr, buffer; |
| 171 | unsigned long devsize; |
| 172 | char *data; |
| 173 | |
| 174 | if (!len) |
| 175 | return NULL; |
| 176 | blocknr = offset >> PAGE_SHIFT; |
| 177 | offset &= PAGE_SIZE - 1; |
| 178 | |
| 179 | /* Check if an existing buffer already has the data.. */ |
| 180 | for (i = 0; i < READ_BUFFERS; i++) { |
| 181 | unsigned int blk_offset; |
| 182 | |
| 183 | if (buffer_dev[i] != sb) |
| 184 | continue; |
| 185 | if (blocknr < buffer_blocknr[i]) |
| 186 | continue; |
| 187 | blk_offset = (blocknr - buffer_blocknr[i]) << PAGE_SHIFT; |
| 188 | blk_offset += offset; |
| 189 | if (blk_offset + len > BUFFER_SIZE) |
| 190 | continue; |
| 191 | return read_buffers[i] + blk_offset; |
| 192 | } |
| 193 | |
| 194 | devsize = mapping->host->i_size >> PAGE_SHIFT; |
| 195 | |
| 196 | /* Ok, read in BLKS_PER_BUF pages completely first. */ |
| 197 | for (i = 0; i < BLKS_PER_BUF; i++) { |
| 198 | struct page *page = NULL; |
| 199 | |
| 200 | if (blocknr + i < devsize) { |
| 201 | page = read_mapping_page(mapping, blocknr + i, NULL); |
| 202 | /* synchronous error? */ |
| 203 | if (IS_ERR(page)) |
| 204 | page = NULL; |
| 205 | } |
| 206 | pages[i] = page; |
| 207 | } |
| 208 | |
| 209 | for (i = 0; i < BLKS_PER_BUF; i++) { |
| 210 | struct page *page = pages[i]; |
| 211 | |
| 212 | if (page) { |
| 213 | wait_on_page_locked(page); |
| 214 | if (!PageUptodate(page)) { |
| 215 | /* asynchronous error */ |
| 216 | put_page(page); |
| 217 | pages[i] = NULL; |
| 218 | } |
| 219 | } |
| 220 | } |
| 221 | |
| 222 | buffer = next_buffer; |
| 223 | next_buffer = NEXT_BUFFER(buffer); |
| 224 | buffer_blocknr[buffer] = blocknr; |
| 225 | buffer_dev[buffer] = sb; |
| 226 | |
| 227 | data = read_buffers[buffer]; |
| 228 | for (i = 0; i < BLKS_PER_BUF; i++) { |
| 229 | struct page *page = pages[i]; |
| 230 | |
| 231 | if (page) { |
| 232 | memcpy(data, kmap(page), PAGE_SIZE); |
| 233 | kunmap(page); |
| 234 | put_page(page); |
| 235 | } else |
| 236 | memset(data, 0, PAGE_SIZE); |
| 237 | data += PAGE_SIZE; |
| 238 | } |
| 239 | return read_buffers[buffer] + offset; |
| 240 | } |
| 241 | |
| 242 | static void cramfs_kill_sb(struct super_block *sb) |
| 243 | { |
| 244 | struct cramfs_sb_info *sbi = CRAMFS_SB(sb); |
| 245 | |
| 246 | kill_block_super(sb); |
| 247 | kfree(sbi); |
| 248 | } |
| 249 | |
| 250 | static int cramfs_remount(struct super_block *sb, int *flags, char *data) |
| 251 | { |
| 252 | sync_filesystem(sb); |
| 253 | *flags |= MS_RDONLY; |
| 254 | return 0; |
| 255 | } |
| 256 | |
| 257 | static int cramfs_fill_super(struct super_block *sb, void *data, int silent) |
| 258 | { |
| 259 | int i; |
| 260 | struct cramfs_super super; |
| 261 | unsigned long root_offset; |
| 262 | struct cramfs_sb_info *sbi; |
| 263 | struct inode *root; |
| 264 | |
| 265 | sb->s_flags |= MS_RDONLY; |
| 266 | |
| 267 | sbi = kzalloc(sizeof(struct cramfs_sb_info), GFP_KERNEL); |
| 268 | if (!sbi) |
| 269 | return -ENOMEM; |
| 270 | sb->s_fs_info = sbi; |
| 271 | |
| 272 | /* Invalidate the read buffers on mount: think disk change.. */ |
| 273 | mutex_lock(&read_mutex); |
| 274 | for (i = 0; i < READ_BUFFERS; i++) |
| 275 | buffer_blocknr[i] = -1; |
| 276 | |
| 277 | /* Read the first block and get the superblock from it */ |
| 278 | memcpy(&super, cramfs_read(sb, 0, sizeof(super)), sizeof(super)); |
| 279 | mutex_unlock(&read_mutex); |
| 280 | |
| 281 | /* Do sanity checks on the superblock */ |
| 282 | if (super.magic != CRAMFS_MAGIC) { |
| 283 | /* check for wrong endianness */ |
| 284 | if (super.magic == CRAMFS_MAGIC_WEND) { |
| 285 | if (!silent) |
| 286 | pr_err("wrong endianness\n"); |
| 287 | return -EINVAL; |
| 288 | } |
| 289 | |
| 290 | /* check at 512 byte offset */ |
| 291 | mutex_lock(&read_mutex); |
| 292 | memcpy(&super, cramfs_read(sb, 512, sizeof(super)), sizeof(super)); |
| 293 | mutex_unlock(&read_mutex); |
| 294 | if (super.magic != CRAMFS_MAGIC) { |
| 295 | if (super.magic == CRAMFS_MAGIC_WEND && !silent) |
| 296 | pr_err("wrong endianness\n"); |
| 297 | else if (!silent) |
| 298 | pr_err("wrong magic\n"); |
| 299 | return -EINVAL; |
| 300 | } |
| 301 | } |
| 302 | |
| 303 | /* get feature flags first */ |
| 304 | if (super.flags & ~CRAMFS_SUPPORTED_FLAGS) { |
| 305 | pr_err("unsupported filesystem features\n"); |
| 306 | return -EINVAL; |
| 307 | } |
| 308 | |
| 309 | /* Check that the root inode is in a sane state */ |
| 310 | if (!S_ISDIR(super.root.mode)) { |
| 311 | pr_err("root is not a directory\n"); |
| 312 | return -EINVAL; |
| 313 | } |
| 314 | /* correct strange, hard-coded permissions of mkcramfs */ |
| 315 | super.root.mode |= (S_IRUSR | S_IXUSR | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH); |
| 316 | |
| 317 | root_offset = super.root.offset << 2; |
| 318 | if (super.flags & CRAMFS_FLAG_FSID_VERSION_2) { |
| 319 | sbi->size = super.size; |
| 320 | sbi->blocks = super.fsid.blocks; |
| 321 | sbi->files = super.fsid.files; |
| 322 | } else { |
| 323 | sbi->size = 1<<28; |
| 324 | sbi->blocks = 0; |
| 325 | sbi->files = 0; |
| 326 | } |
| 327 | sbi->magic = super.magic; |
| 328 | sbi->flags = super.flags; |
| 329 | if (root_offset == 0) |
| 330 | pr_info("empty filesystem"); |
| 331 | else if (!(super.flags & CRAMFS_FLAG_SHIFTED_ROOT_OFFSET) && |
| 332 | ((root_offset != sizeof(struct cramfs_super)) && |
| 333 | (root_offset != 512 + sizeof(struct cramfs_super)))) |
| 334 | { |
| 335 | pr_err("bad root offset %lu\n", root_offset); |
| 336 | return -EINVAL; |
| 337 | } |
| 338 | |
| 339 | /* Set it all up.. */ |
| 340 | sb->s_op = &cramfs_ops; |
| 341 | root = get_cramfs_inode(sb, &super.root, 0); |
| 342 | if (IS_ERR(root)) |
| 343 | return PTR_ERR(root); |
| 344 | sb->s_root = d_make_root(root); |
| 345 | if (!sb->s_root) |
| 346 | return -ENOMEM; |
| 347 | return 0; |
| 348 | } |
| 349 | |
| 350 | static int cramfs_statfs(struct dentry *dentry, struct kstatfs *buf) |
| 351 | { |
| 352 | struct super_block *sb = dentry->d_sb; |
| 353 | u64 id = huge_encode_dev(sb->s_bdev->bd_dev); |
| 354 | |
| 355 | buf->f_type = CRAMFS_MAGIC; |
| 356 | buf->f_bsize = PAGE_SIZE; |
| 357 | buf->f_blocks = CRAMFS_SB(sb)->blocks; |
| 358 | buf->f_bfree = 0; |
| 359 | buf->f_bavail = 0; |
| 360 | buf->f_files = CRAMFS_SB(sb)->files; |
| 361 | buf->f_ffree = 0; |
| 362 | buf->f_fsid.val[0] = (u32)id; |
| 363 | buf->f_fsid.val[1] = (u32)(id >> 32); |
| 364 | buf->f_namelen = CRAMFS_MAXPATHLEN; |
| 365 | return 0; |
| 366 | } |
| 367 | |
| 368 | /* |
| 369 | * Read a cramfs directory entry. |
| 370 | */ |
| 371 | static int cramfs_readdir(struct file *file, struct dir_context *ctx) |
| 372 | { |
| 373 | struct inode *inode = file_inode(file); |
| 374 | struct super_block *sb = inode->i_sb; |
| 375 | char *buf; |
| 376 | unsigned int offset; |
| 377 | |
| 378 | /* Offset within the thing. */ |
| 379 | if (ctx->pos >= inode->i_size) |
| 380 | return 0; |
| 381 | offset = ctx->pos; |
| 382 | /* Directory entries are always 4-byte aligned */ |
| 383 | if (offset & 3) |
| 384 | return -EINVAL; |
| 385 | |
| 386 | buf = kmalloc(CRAMFS_MAXPATHLEN, GFP_KERNEL); |
| 387 | if (!buf) |
| 388 | return -ENOMEM; |
| 389 | |
| 390 | while (offset < inode->i_size) { |
| 391 | struct cramfs_inode *de; |
| 392 | unsigned long nextoffset; |
| 393 | char *name; |
| 394 | ino_t ino; |
| 395 | umode_t mode; |
| 396 | int namelen; |
| 397 | |
| 398 | mutex_lock(&read_mutex); |
| 399 | de = cramfs_read(sb, OFFSET(inode) + offset, sizeof(*de)+CRAMFS_MAXPATHLEN); |
| 400 | name = (char *)(de+1); |
| 401 | |
| 402 | /* |
| 403 | * Namelengths on disk are shifted by two |
| 404 | * and the name padded out to 4-byte boundaries |
| 405 | * with zeroes. |
| 406 | */ |
| 407 | namelen = de->namelen << 2; |
| 408 | memcpy(buf, name, namelen); |
| 409 | ino = cramino(de, OFFSET(inode) + offset); |
| 410 | mode = de->mode; |
| 411 | mutex_unlock(&read_mutex); |
| 412 | nextoffset = offset + sizeof(*de) + namelen; |
| 413 | for (;;) { |
| 414 | if (!namelen) { |
| 415 | kfree(buf); |
| 416 | return -EIO; |
| 417 | } |
| 418 | if (buf[namelen-1]) |
| 419 | break; |
| 420 | namelen--; |
| 421 | } |
| 422 | if (!dir_emit(ctx, buf, namelen, ino, mode >> 12)) |
| 423 | break; |
| 424 | |
| 425 | ctx->pos = offset = nextoffset; |
| 426 | } |
| 427 | kfree(buf); |
| 428 | return 0; |
| 429 | } |
| 430 | |
| 431 | /* |
| 432 | * Lookup and fill in the inode data.. |
| 433 | */ |
| 434 | static struct dentry *cramfs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) |
| 435 | { |
| 436 | unsigned int offset = 0; |
| 437 | struct inode *inode = NULL; |
| 438 | int sorted; |
| 439 | |
| 440 | mutex_lock(&read_mutex); |
| 441 | sorted = CRAMFS_SB(dir->i_sb)->flags & CRAMFS_FLAG_SORTED_DIRS; |
| 442 | while (offset < dir->i_size) { |
| 443 | struct cramfs_inode *de; |
| 444 | char *name; |
| 445 | int namelen, retval; |
| 446 | int dir_off = OFFSET(dir) + offset; |
| 447 | |
| 448 | de = cramfs_read(dir->i_sb, dir_off, sizeof(*de)+CRAMFS_MAXPATHLEN); |
| 449 | name = (char *)(de+1); |
| 450 | |
| 451 | /* Try to take advantage of sorted directories */ |
| 452 | if (sorted && (dentry->d_name.name[0] < name[0])) |
| 453 | break; |
| 454 | |
| 455 | namelen = de->namelen << 2; |
| 456 | offset += sizeof(*de) + namelen; |
| 457 | |
| 458 | /* Quick check that the name is roughly the right length */ |
| 459 | if (((dentry->d_name.len + 3) & ~3) != namelen) |
| 460 | continue; |
| 461 | |
| 462 | for (;;) { |
| 463 | if (!namelen) { |
| 464 | inode = ERR_PTR(-EIO); |
| 465 | goto out; |
| 466 | } |
| 467 | if (name[namelen-1]) |
| 468 | break; |
| 469 | namelen--; |
| 470 | } |
| 471 | if (namelen != dentry->d_name.len) |
| 472 | continue; |
| 473 | retval = memcmp(dentry->d_name.name, name, namelen); |
| 474 | if (retval > 0) |
| 475 | continue; |
| 476 | if (!retval) { |
| 477 | inode = get_cramfs_inode(dir->i_sb, de, dir_off); |
| 478 | break; |
| 479 | } |
| 480 | /* else (retval < 0) */ |
| 481 | if (sorted) |
| 482 | break; |
| 483 | } |
| 484 | out: |
| 485 | mutex_unlock(&read_mutex); |
| 486 | if (IS_ERR(inode)) |
| 487 | return ERR_CAST(inode); |
| 488 | d_add(dentry, inode); |
| 489 | return NULL; |
| 490 | } |
| 491 | |
| 492 | static int cramfs_readpage(struct file *file, struct page *page) |
| 493 | { |
| 494 | struct inode *inode = page->mapping->host; |
| 495 | u32 maxblock; |
| 496 | int bytes_filled; |
| 497 | void *pgdata; |
| 498 | |
| 499 | maxblock = (inode->i_size + PAGE_SIZE - 1) >> PAGE_SHIFT; |
| 500 | bytes_filled = 0; |
| 501 | pgdata = kmap(page); |
| 502 | |
| 503 | if (page->index < maxblock) { |
| 504 | struct super_block *sb = inode->i_sb; |
| 505 | u32 blkptr_offset = OFFSET(inode) + page->index*4; |
| 506 | u32 start_offset, compr_len; |
| 507 | |
| 508 | start_offset = OFFSET(inode) + maxblock*4; |
| 509 | mutex_lock(&read_mutex); |
| 510 | if (page->index) |
| 511 | start_offset = *(u32 *) cramfs_read(sb, blkptr_offset-4, |
| 512 | 4); |
| 513 | compr_len = (*(u32 *) cramfs_read(sb, blkptr_offset, 4) - |
| 514 | start_offset); |
| 515 | mutex_unlock(&read_mutex); |
| 516 | |
| 517 | if (compr_len == 0) |
| 518 | ; /* hole */ |
| 519 | else if (unlikely(compr_len > (PAGE_SIZE << 1))) { |
| 520 | pr_err("bad compressed blocksize %u\n", |
| 521 | compr_len); |
| 522 | goto err; |
| 523 | } else { |
| 524 | mutex_lock(&read_mutex); |
| 525 | bytes_filled = cramfs_uncompress_block(pgdata, |
| 526 | PAGE_SIZE, |
| 527 | cramfs_read(sb, start_offset, compr_len), |
| 528 | compr_len); |
| 529 | mutex_unlock(&read_mutex); |
| 530 | if (unlikely(bytes_filled < 0)) |
| 531 | goto err; |
| 532 | } |
| 533 | } |
| 534 | |
| 535 | memset(pgdata + bytes_filled, 0, PAGE_SIZE - bytes_filled); |
| 536 | flush_dcache_page(page); |
| 537 | kunmap(page); |
| 538 | SetPageUptodate(page); |
| 539 | unlock_page(page); |
| 540 | return 0; |
| 541 | |
| 542 | err: |
| 543 | kunmap(page); |
| 544 | ClearPageUptodate(page); |
| 545 | SetPageError(page); |
| 546 | unlock_page(page); |
| 547 | return 0; |
| 548 | } |
| 549 | |
| 550 | static const struct address_space_operations cramfs_aops = { |
| 551 | .readpage = cramfs_readpage |
| 552 | }; |
| 553 | |
| 554 | /* |
| 555 | * Our operations: |
| 556 | */ |
| 557 | |
| 558 | /* |
| 559 | * A directory can only readdir |
| 560 | */ |
| 561 | static const struct file_operations cramfs_directory_operations = { |
| 562 | .llseek = generic_file_llseek, |
| 563 | .read = generic_read_dir, |
| 564 | .iterate_shared = cramfs_readdir, |
| 565 | }; |
| 566 | |
| 567 | static const struct inode_operations cramfs_dir_inode_operations = { |
| 568 | .lookup = cramfs_lookup, |
| 569 | }; |
| 570 | |
| 571 | static const struct super_operations cramfs_ops = { |
| 572 | .remount_fs = cramfs_remount, |
| 573 | .statfs = cramfs_statfs, |
| 574 | }; |
| 575 | |
| 576 | static struct dentry *cramfs_mount(struct file_system_type *fs_type, |
| 577 | int flags, const char *dev_name, void *data) |
| 578 | { |
| 579 | return mount_bdev(fs_type, flags, dev_name, data, cramfs_fill_super); |
| 580 | } |
| 581 | |
| 582 | static struct file_system_type cramfs_fs_type = { |
| 583 | .owner = THIS_MODULE, |
| 584 | .name = "cramfs", |
| 585 | .mount = cramfs_mount, |
| 586 | .kill_sb = cramfs_kill_sb, |
| 587 | .fs_flags = FS_REQUIRES_DEV, |
| 588 | }; |
| 589 | MODULE_ALIAS_FS("cramfs"); |
| 590 | |
| 591 | static int __init init_cramfs_fs(void) |
| 592 | { |
| 593 | int rv; |
| 594 | |
| 595 | rv = cramfs_uncompress_init(); |
| 596 | if (rv < 0) |
| 597 | return rv; |
| 598 | rv = register_filesystem(&cramfs_fs_type); |
| 599 | if (rv < 0) |
| 600 | cramfs_uncompress_exit(); |
| 601 | return rv; |
| 602 | } |
| 603 | |
| 604 | static void __exit exit_cramfs_fs(void) |
| 605 | { |
| 606 | cramfs_uncompress_exit(); |
| 607 | unregister_filesystem(&cramfs_fs_type); |
| 608 | } |
| 609 | |
| 610 | module_init(init_cramfs_fs) |
| 611 | module_exit(exit_cramfs_fs) |
| 612 | MODULE_LICENSE("GPL"); |