Commit | Line | Data |
---|---|---|
1da177e4 LT |
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 | ||
4f21e1ea FF |
14 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
15 | ||
1da177e4 LT |
16 | #include <linux/module.h> |
17 | #include <linux/fs.h> | |
eddcd976 | 18 | #include <linux/file.h> |
1da177e4 | 19 | #include <linux/pagemap.h> |
eddcd976 NP |
20 | #include <linux/pfn_t.h> |
21 | #include <linux/ramfs.h> | |
1da177e4 LT |
22 | #include <linux/init.h> |
23 | #include <linux/string.h> | |
24 | #include <linux/blkdev.h> | |
99c18ce5 NP |
25 | #include <linux/mtd/mtd.h> |
26 | #include <linux/mtd/super.h> | |
74f78fc5 | 27 | #include <linux/fs_context.h> |
1da177e4 | 28 | #include <linux/slab.h> |
1da177e4 | 29 | #include <linux/vfs.h> |
353ab6e9 | 30 | #include <linux/mutex.h> |
f7f4f4dd | 31 | #include <uapi/linux/cramfs_fs.h> |
1508f3eb | 32 | #include <linux/uaccess.h> |
1da177e4 | 33 | |
f7f4f4dd AV |
34 | #include "internal.h" |
35 | ||
36 | /* | |
37 | * cramfs super-block data in memory | |
38 | */ | |
39 | struct cramfs_sb_info { | |
40 | unsigned long magic; | |
41 | unsigned long size; | |
42 | unsigned long blocks; | |
43 | unsigned long files; | |
44 | unsigned long flags; | |
99c18ce5 NP |
45 | void *linear_virt_addr; |
46 | resource_size_t linear_phys_addr; | |
47 | size_t mtd_point_size; | |
f7f4f4dd AV |
48 | }; |
49 | ||
50 | static inline struct cramfs_sb_info *CRAMFS_SB(struct super_block *sb) | |
51 | { | |
52 | return sb->s_fs_info; | |
53 | } | |
54 | ||
ee9b6d61 | 55 | static const struct super_operations cramfs_ops; |
754661f1 | 56 | static const struct inode_operations cramfs_dir_inode_operations; |
4b6f5d20 | 57 | static const struct file_operations cramfs_directory_operations; |
eddcd976 | 58 | static const struct file_operations cramfs_physmem_fops; |
f5e54d6e | 59 | static const struct address_space_operations cramfs_aops; |
1da177e4 | 60 | |
353ab6e9 | 61 | static DEFINE_MUTEX(read_mutex); |
1da177e4 LT |
62 | |
63 | ||
6f772fe6 | 64 | /* These macros may change in future, to provide better st_ino semantics. */ |
1da177e4 LT |
65 | #define OFFSET(x) ((x)->i_ino) |
66 | ||
0577d1ba | 67 | static unsigned long cramino(const struct cramfs_inode *cino, unsigned int offset) |
a97c9bf3 | 68 | { |
6f772fe6 SS |
69 | if (!cino->offset) |
70 | return offset + 1; | |
71 | if (!cino->size) | |
72 | return offset + 1; | |
73 | ||
74 | /* | |
75 | * The file mode test fixes buggy mkcramfs implementations where | |
76 | * cramfs_inode->offset is set to a non zero value for entries | |
77 | * which did not contain data, like devices node and fifos. | |
78 | */ | |
79 | switch (cino->mode & S_IFMT) { | |
80 | case S_IFREG: | |
81 | case S_IFDIR: | |
82 | case S_IFLNK: | |
83 | return cino->offset << 2; | |
84 | default: | |
85 | break; | |
86 | } | |
87 | return offset + 1; | |
88 | } | |
89 | ||
90 | static struct inode *get_cramfs_inode(struct super_block *sb, | |
0577d1ba | 91 | const struct cramfs_inode *cramfs_inode, unsigned int offset) |
6f772fe6 SS |
92 | { |
93 | struct inode *inode; | |
95582b00 | 94 | static struct timespec64 zerotime; |
6f772fe6 SS |
95 | |
96 | inode = iget_locked(sb, cramino(cramfs_inode, offset)); | |
97 | if (!inode) | |
98 | return ERR_PTR(-ENOMEM); | |
99 | if (!(inode->i_state & I_NEW)) | |
100 | return inode; | |
101 | ||
102 | switch (cramfs_inode->mode & S_IFMT) { | |
103 | case S_IFREG: | |
104 | inode->i_fop = &generic_ro_fops; | |
105 | inode->i_data.a_ops = &cramfs_aops; | |
eddcd976 NP |
106 | if (IS_ENABLED(CONFIG_CRAMFS_MTD) && |
107 | CRAMFS_SB(sb)->flags & CRAMFS_FLAG_EXT_BLOCK_POINTERS && | |
108 | CRAMFS_SB(sb)->linear_phys_addr) | |
109 | inode->i_fop = &cramfs_physmem_fops; | |
6f772fe6 SS |
110 | break; |
111 | case S_IFDIR: | |
112 | inode->i_op = &cramfs_dir_inode_operations; | |
113 | inode->i_fop = &cramfs_directory_operations; | |
114 | break; | |
115 | case S_IFLNK: | |
116 | inode->i_op = &page_symlink_inode_operations; | |
21fc61c7 | 117 | inode_nohighmem(inode); |
6f772fe6 SS |
118 | inode->i_data.a_ops = &cramfs_aops; |
119 | break; | |
120 | default: | |
121 | init_special_inode(inode, cramfs_inode->mode, | |
122 | old_decode_dev(cramfs_inode->size)); | |
123 | } | |
124 | ||
77b8a75f | 125 | inode->i_mode = cramfs_inode->mode; |
a7d9cfe9 EB |
126 | i_uid_write(inode, cramfs_inode->uid); |
127 | i_gid_write(inode, cramfs_inode->gid); | |
6f772fe6 SS |
128 | |
129 | /* if the lower 2 bits are zero, the inode contains data */ | |
130 | if (!(inode->i_ino & 3)) { | |
131 | inode->i_size = cramfs_inode->size; | |
132 | inode->i_blocks = (cramfs_inode->size - 1) / 512 + 1; | |
133 | } | |
134 | ||
77b8a75f AV |
135 | /* Struct copy intentional */ |
136 | inode->i_mtime = inode->i_atime = inode->i_ctime = zerotime; | |
137 | /* inode->i_nlink is left 1 - arguably wrong for directories, | |
138 | but it's the best we can do without reading the directory | |
139 | contents. 1 yields the right result in GNU find, even | |
140 | without -noleaf option. */ | |
a97c9bf3 | 141 | |
6f772fe6 SS |
142 | unlock_new_inode(inode); |
143 | ||
1da177e4 LT |
144 | return inode; |
145 | } | |
146 | ||
147 | /* | |
148 | * We have our own block cache: don't fill up the buffer cache | |
149 | * with the rom-image, because the way the filesystem is set | |
150 | * up the accesses should be fairly regular and cached in the | |
151 | * page cache and dentry tree anyway.. | |
152 | * | |
153 | * This also acts as a way to guarantee contiguous areas of up to | |
ea1754a0 | 154 | * BLKS_PER_BUF*PAGE_SIZE, so that the caller doesn't need to |
1da177e4 LT |
155 | * worry about end-of-buffer issues even when decompressing a full |
156 | * page cache. | |
99c18ce5 NP |
157 | * |
158 | * Note: This is all optimized away at compile time when | |
159 | * CONFIG_CRAMFS_BLOCKDEV=n. | |
1da177e4 LT |
160 | */ |
161 | #define READ_BUFFERS (2) | |
162 | /* NEXT_BUFFER(): Loop over [0..(READ_BUFFERS-1)]. */ | |
163 | #define NEXT_BUFFER(_ix) ((_ix) ^ 1) | |
164 | ||
165 | /* | |
166 | * BLKS_PER_BUF_SHIFT should be at least 2 to allow for "compressed" | |
167 | * data that takes up more space than the original and with unlucky | |
168 | * alignment. | |
169 | */ | |
170 | #define BLKS_PER_BUF_SHIFT (2) | |
171 | #define BLKS_PER_BUF (1 << BLKS_PER_BUF_SHIFT) | |
09cbfeaf | 172 | #define BUFFER_SIZE (BLKS_PER_BUF*PAGE_SIZE) |
1da177e4 LT |
173 | |
174 | static unsigned char read_buffers[READ_BUFFERS][BUFFER_SIZE]; | |
175 | static unsigned buffer_blocknr[READ_BUFFERS]; | |
31d92e55 | 176 | static struct super_block *buffer_dev[READ_BUFFERS]; |
1da177e4 LT |
177 | static int next_buffer; |
178 | ||
179 | /* | |
99c18ce5 | 180 | * Populate our block cache and return a pointer to it. |
1da177e4 | 181 | */ |
99c18ce5 NP |
182 | static void *cramfs_blkdev_read(struct super_block *sb, unsigned int offset, |
183 | unsigned int len) | |
1da177e4 LT |
184 | { |
185 | struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping; | |
3e351026 | 186 | struct file_ra_state ra = {}; |
1da177e4 | 187 | struct page *pages[BLKS_PER_BUF]; |
6bbfb077 | 188 | unsigned i, blocknr, buffer; |
1da177e4 LT |
189 | unsigned long devsize; |
190 | char *data; | |
191 | ||
192 | if (!len) | |
193 | return NULL; | |
09cbfeaf KS |
194 | blocknr = offset >> PAGE_SHIFT; |
195 | offset &= PAGE_SIZE - 1; | |
1da177e4 LT |
196 | |
197 | /* Check if an existing buffer already has the data.. */ | |
198 | for (i = 0; i < READ_BUFFERS; i++) { | |
199 | unsigned int blk_offset; | |
200 | ||
201 | if (buffer_dev[i] != sb) | |
202 | continue; | |
203 | if (blocknr < buffer_blocknr[i]) | |
204 | continue; | |
09cbfeaf | 205 | blk_offset = (blocknr - buffer_blocknr[i]) << PAGE_SHIFT; |
1da177e4 | 206 | blk_offset += offset; |
672ca9dd NP |
207 | if (blk_offset > BUFFER_SIZE || |
208 | blk_offset + len > BUFFER_SIZE) | |
1da177e4 LT |
209 | continue; |
210 | return read_buffers[i] + blk_offset; | |
211 | } | |
212 | ||
5816e91e | 213 | devsize = bdev_nr_bytes(sb->s_bdev) >> PAGE_SHIFT; |
1da177e4 LT |
214 | |
215 | /* Ok, read in BLKS_PER_BUF pages completely first. */ | |
cf948cbc MWO |
216 | file_ra_state_init(&ra, mapping); |
217 | page_cache_sync_readahead(mapping, &ra, NULL, blocknr, BLKS_PER_BUF); | |
218 | ||
1da177e4 LT |
219 | for (i = 0; i < BLKS_PER_BUF; i++) { |
220 | struct page *page = NULL; | |
221 | ||
222 | if (blocknr + i < devsize) { | |
67f9fd91 | 223 | page = read_mapping_page(mapping, blocknr + i, NULL); |
1da177e4 LT |
224 | /* synchronous error? */ |
225 | if (IS_ERR(page)) | |
226 | page = NULL; | |
227 | } | |
228 | pages[i] = page; | |
229 | } | |
230 | ||
1da177e4 LT |
231 | buffer = next_buffer; |
232 | next_buffer = NEXT_BUFFER(buffer); | |
233 | buffer_blocknr[buffer] = blocknr; | |
234 | buffer_dev[buffer] = sb; | |
235 | ||
236 | data = read_buffers[buffer]; | |
237 | for (i = 0; i < BLKS_PER_BUF; i++) { | |
238 | struct page *page = pages[i]; | |
31d92e55 | 239 | |
1da177e4 | 240 | if (page) { |
f27c942e | 241 | memcpy_from_page(data, page, 0, PAGE_SIZE); |
09cbfeaf | 242 | put_page(page); |
1da177e4 | 243 | } else |
09cbfeaf KS |
244 | memset(data, 0, PAGE_SIZE); |
245 | data += PAGE_SIZE; | |
1da177e4 LT |
246 | } |
247 | return read_buffers[buffer] + offset; | |
248 | } | |
249 | ||
99c18ce5 NP |
250 | /* |
251 | * Return a pointer to the linearly addressed cramfs image in memory. | |
252 | */ | |
253 | static void *cramfs_direct_read(struct super_block *sb, unsigned int offset, | |
254 | unsigned int len) | |
255 | { | |
256 | struct cramfs_sb_info *sbi = CRAMFS_SB(sb); | |
257 | ||
258 | if (!len) | |
259 | return NULL; | |
260 | if (len > sbi->size || offset > sbi->size - len) | |
261 | return page_address(ZERO_PAGE(0)); | |
262 | return sbi->linear_virt_addr + offset; | |
263 | } | |
264 | ||
265 | /* | |
266 | * Returns a pointer to a buffer containing at least LEN bytes of | |
267 | * filesystem starting at byte offset OFFSET into the filesystem. | |
268 | */ | |
269 | static void *cramfs_read(struct super_block *sb, unsigned int offset, | |
270 | unsigned int len) | |
271 | { | |
272 | struct cramfs_sb_info *sbi = CRAMFS_SB(sb); | |
273 | ||
274 | if (IS_ENABLED(CONFIG_CRAMFS_MTD) && sbi->linear_virt_addr) | |
275 | return cramfs_direct_read(sb, offset, len); | |
276 | else if (IS_ENABLED(CONFIG_CRAMFS_BLOCKDEV)) | |
277 | return cramfs_blkdev_read(sb, offset, len); | |
278 | else | |
279 | return NULL; | |
280 | } | |
281 | ||
eddcd976 NP |
282 | /* |
283 | * For a mapping to be possible, we need a range of uncompressed and | |
284 | * contiguous blocks. Return the offset for the first block and number of | |
285 | * valid blocks for which that is true, or zero otherwise. | |
286 | */ | |
287 | static u32 cramfs_get_block_range(struct inode *inode, u32 pgoff, u32 *pages) | |
288 | { | |
289 | struct cramfs_sb_info *sbi = CRAMFS_SB(inode->i_sb); | |
290 | int i; | |
291 | u32 *blockptrs, first_block_addr; | |
292 | ||
293 | /* | |
294 | * We can dereference memory directly here as this code may be | |
295 | * reached only when there is a direct filesystem image mapping | |
296 | * available in memory. | |
297 | */ | |
298 | blockptrs = (u32 *)(sbi->linear_virt_addr + OFFSET(inode) + pgoff * 4); | |
299 | first_block_addr = blockptrs[0] & ~CRAMFS_BLK_FLAGS; | |
300 | i = 0; | |
301 | do { | |
302 | u32 block_off = i * (PAGE_SIZE >> CRAMFS_BLK_DIRECT_PTR_SHIFT); | |
303 | u32 expect = (first_block_addr + block_off) | | |
304 | CRAMFS_BLK_FLAG_DIRECT_PTR | | |
305 | CRAMFS_BLK_FLAG_UNCOMPRESSED; | |
306 | if (blockptrs[i] != expect) { | |
307 | pr_debug("range: block %d/%d got %#x expects %#x\n", | |
308 | pgoff+i, pgoff + *pages - 1, | |
309 | blockptrs[i], expect); | |
310 | if (i == 0) | |
311 | return 0; | |
312 | break; | |
313 | } | |
314 | } while (++i < *pages); | |
315 | ||
316 | *pages = i; | |
317 | return first_block_addr << CRAMFS_BLK_DIRECT_PTR_SHIFT; | |
318 | } | |
319 | ||
320 | #ifdef CONFIG_MMU | |
321 | ||
322 | /* | |
323 | * Return true if the last page of a file in the filesystem image contains | |
324 | * some other data that doesn't belong to that file. It is assumed that the | |
325 | * last block is CRAMFS_BLK_FLAG_DIRECT_PTR | CRAMFS_BLK_FLAG_UNCOMPRESSED | |
326 | * (verified by cramfs_get_block_range() and directly accessible in memory. | |
327 | */ | |
328 | static bool cramfs_last_page_is_shared(struct inode *inode) | |
329 | { | |
330 | struct cramfs_sb_info *sbi = CRAMFS_SB(inode->i_sb); | |
331 | u32 partial, last_page, blockaddr, *blockptrs; | |
332 | char *tail_data; | |
333 | ||
334 | partial = offset_in_page(inode->i_size); | |
335 | if (!partial) | |
336 | return false; | |
337 | last_page = inode->i_size >> PAGE_SHIFT; | |
338 | blockptrs = (u32 *)(sbi->linear_virt_addr + OFFSET(inode)); | |
339 | blockaddr = blockptrs[last_page] & ~CRAMFS_BLK_FLAGS; | |
340 | blockaddr <<= CRAMFS_BLK_DIRECT_PTR_SHIFT; | |
341 | tail_data = sbi->linear_virt_addr + blockaddr + partial; | |
342 | return memchr_inv(tail_data, 0, PAGE_SIZE - partial) ? true : false; | |
343 | } | |
344 | ||
345 | static int cramfs_physmem_mmap(struct file *file, struct vm_area_struct *vma) | |
346 | { | |
347 | struct inode *inode = file_inode(file); | |
348 | struct cramfs_sb_info *sbi = CRAMFS_SB(inode->i_sb); | |
349 | unsigned int pages, max_pages, offset; | |
350 | unsigned long address, pgoff = vma->vm_pgoff; | |
351 | char *bailout_reason; | |
352 | int ret; | |
353 | ||
354 | ret = generic_file_readonly_mmap(file, vma); | |
355 | if (ret) | |
356 | return ret; | |
357 | ||
358 | /* | |
359 | * Now try to pre-populate ptes for this vma with a direct | |
360 | * mapping avoiding memory allocation when possible. | |
361 | */ | |
362 | ||
363 | /* Could COW work here? */ | |
364 | bailout_reason = "vma is writable"; | |
365 | if (vma->vm_flags & VM_WRITE) | |
366 | goto bailout; | |
367 | ||
368 | max_pages = (inode->i_size + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
369 | bailout_reason = "beyond file limit"; | |
370 | if (pgoff >= max_pages) | |
371 | goto bailout; | |
372 | pages = min(vma_pages(vma), max_pages - pgoff); | |
373 | ||
374 | offset = cramfs_get_block_range(inode, pgoff, &pages); | |
375 | bailout_reason = "unsuitable block layout"; | |
376 | if (!offset) | |
377 | goto bailout; | |
378 | address = sbi->linear_phys_addr + offset; | |
379 | bailout_reason = "data is not page aligned"; | |
380 | if (!PAGE_ALIGNED(address)) | |
381 | goto bailout; | |
382 | ||
383 | /* Don't map the last page if it contains some other data */ | |
384 | if (pgoff + pages == max_pages && cramfs_last_page_is_shared(inode)) { | |
aa7d5c7e | 385 | pr_debug("mmap: %pD: last page is shared\n", file); |
eddcd976 NP |
386 | pages--; |
387 | } | |
388 | ||
389 | if (!pages) { | |
390 | bailout_reason = "no suitable block remaining"; | |
391 | goto bailout; | |
392 | } | |
393 | ||
394 | if (pages == vma_pages(vma)) { | |
395 | /* | |
396 | * The entire vma is mappable. remap_pfn_range() will | |
397 | * make it distinguishable from a non-direct mapping | |
398 | * in /proc/<pid>/maps by substituting the file offset | |
399 | * with the actual physical address. | |
400 | */ | |
401 | ret = remap_pfn_range(vma, vma->vm_start, address >> PAGE_SHIFT, | |
402 | pages * PAGE_SIZE, vma->vm_page_prot); | |
403 | } else { | |
404 | /* | |
405 | * Let's create a mixed map if we can't map it all. | |
406 | * The normal paging machinery will take care of the | |
5aab331a | 407 | * unpopulated ptes via cramfs_read_folio(). |
eddcd976 NP |
408 | */ |
409 | int i; | |
1c71222e | 410 | vm_flags_set(vma, VM_MIXEDMAP); |
eddcd976 | 411 | for (i = 0; i < pages && !ret; i++) { |
7f2764cf | 412 | vm_fault_t vmf; |
eddcd976 NP |
413 | unsigned long off = i * PAGE_SIZE; |
414 | pfn_t pfn = phys_to_pfn_t(address + off, PFN_DEV); | |
7f2764cf NP |
415 | vmf = vmf_insert_mixed(vma, vma->vm_start + off, pfn); |
416 | if (vmf & VM_FAULT_ERROR) | |
417 | ret = vm_fault_to_errno(vmf, 0); | |
eddcd976 NP |
418 | } |
419 | } | |
420 | ||
421 | if (!ret) | |
aa7d5c7e AV |
422 | pr_debug("mapped %pD[%lu] at 0x%08lx (%u/%lu pages) " |
423 | "to vma 0x%08lx, page_prot 0x%llx\n", file, | |
424 | pgoff, address, pages, vma_pages(vma), vma->vm_start, | |
eddcd976 NP |
425 | (unsigned long long)pgprot_val(vma->vm_page_prot)); |
426 | return ret; | |
427 | ||
428 | bailout: | |
aa7d5c7e AV |
429 | pr_debug("%pD[%lu]: direct mmap impossible: %s\n", |
430 | file, pgoff, bailout_reason); | |
eddcd976 NP |
431 | /* Didn't manage any direct map, but normal paging is still possible */ |
432 | return 0; | |
433 | } | |
434 | ||
435 | #else /* CONFIG_MMU */ | |
436 | ||
437 | static int cramfs_physmem_mmap(struct file *file, struct vm_area_struct *vma) | |
438 | { | |
fc4f4be9 | 439 | return is_nommu_shared_mapping(vma->vm_flags) ? 0 : -ENOSYS; |
eddcd976 NP |
440 | } |
441 | ||
442 | static unsigned long cramfs_physmem_get_unmapped_area(struct file *file, | |
443 | unsigned long addr, unsigned long len, | |
444 | unsigned long pgoff, unsigned long flags) | |
445 | { | |
446 | struct inode *inode = file_inode(file); | |
447 | struct super_block *sb = inode->i_sb; | |
448 | struct cramfs_sb_info *sbi = CRAMFS_SB(sb); | |
449 | unsigned int pages, block_pages, max_pages, offset; | |
450 | ||
451 | pages = (len + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
452 | max_pages = (inode->i_size + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
453 | if (pgoff >= max_pages || pages > max_pages - pgoff) | |
454 | return -EINVAL; | |
455 | block_pages = pages; | |
456 | offset = cramfs_get_block_range(inode, pgoff, &block_pages); | |
457 | if (!offset || block_pages != pages) | |
458 | return -ENOSYS; | |
459 | addr = sbi->linear_phys_addr + offset; | |
aa7d5c7e AV |
460 | pr_debug("get_unmapped for %pD ofs %#lx siz %lu at 0x%08lx\n", |
461 | file, pgoff*PAGE_SIZE, len, addr); | |
eddcd976 NP |
462 | return addr; |
463 | } | |
464 | ||
465 | static unsigned int cramfs_physmem_mmap_capabilities(struct file *file) | |
466 | { | |
467 | return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | | |
468 | NOMMU_MAP_READ | NOMMU_MAP_EXEC; | |
469 | } | |
470 | ||
471 | #endif /* CONFIG_MMU */ | |
472 | ||
473 | static const struct file_operations cramfs_physmem_fops = { | |
474 | .llseek = generic_file_llseek, | |
475 | .read_iter = generic_file_read_iter, | |
476 | .splice_read = generic_file_splice_read, | |
477 | .mmap = cramfs_physmem_mmap, | |
478 | #ifndef CONFIG_MMU | |
479 | .get_unmapped_area = cramfs_physmem_get_unmapped_area, | |
480 | .mmap_capabilities = cramfs_physmem_mmap_capabilities, | |
481 | #endif | |
482 | }; | |
483 | ||
2309fb8e | 484 | static void cramfs_kill_sb(struct super_block *sb) |
1da177e4 | 485 | { |
f7f4f4dd | 486 | struct cramfs_sb_info *sbi = CRAMFS_SB(sb); |
31d92e55 | 487 | |
08a8f308 | 488 | if (IS_ENABLED(CONFIG_CRAMFS_MTD) && sb->s_mtd) { |
99c18ce5 NP |
489 | if (sbi && sbi->mtd_point_size) |
490 | mtd_unpoint(sb->s_mtd, 0, sbi->mtd_point_size); | |
491 | kill_mtd_super(sb); | |
492 | } else if (IS_ENABLED(CONFIG_CRAMFS_BLOCKDEV) && sb->s_bdev) { | |
493 | kill_block_super(sb); | |
494 | } | |
2309fb8e | 495 | kfree(sbi); |
1da177e4 LT |
496 | } |
497 | ||
74f78fc5 | 498 | static int cramfs_reconfigure(struct fs_context *fc) |
1da177e4 | 499 | { |
74f78fc5 DH |
500 | sync_filesystem(fc->root->d_sb); |
501 | fc->sb_flags |= SB_RDONLY; | |
1da177e4 LT |
502 | return 0; |
503 | } | |
504 | ||
74f78fc5 DH |
505 | static int cramfs_read_super(struct super_block *sb, struct fs_context *fc, |
506 | struct cramfs_super *super) | |
1da177e4 | 507 | { |
99c18ce5 | 508 | struct cramfs_sb_info *sbi = CRAMFS_SB(sb); |
1da177e4 | 509 | unsigned long root_offset; |
74f78fc5 | 510 | bool silent = fc->sb_flags & SB_SILENT; |
1da177e4 | 511 | |
99c18ce5 NP |
512 | /* We don't know the real size yet */ |
513 | sbi->size = PAGE_SIZE; | |
1da177e4 LT |
514 | |
515 | /* Read the first block and get the superblock from it */ | |
99c18ce5 NP |
516 | mutex_lock(&read_mutex); |
517 | memcpy(super, cramfs_read(sb, 0, sizeof(*super)), sizeof(*super)); | |
353ab6e9 | 518 | mutex_unlock(&read_mutex); |
1da177e4 LT |
519 | |
520 | /* Do sanity checks on the superblock */ | |
99c18ce5 | 521 | if (super->magic != CRAMFS_MAGIC) { |
0cc785ec | 522 | /* check for wrong endianness */ |
99c18ce5 | 523 | if (super->magic == CRAMFS_MAGIC_WEND) { |
ac8d35c5 | 524 | if (!silent) |
e1ee7d85 | 525 | errorfc(fc, "wrong endianness"); |
2309fb8e | 526 | return -EINVAL; |
ac8d35c5 AD |
527 | } |
528 | ||
1da177e4 | 529 | /* check at 512 byte offset */ |
353ab6e9 | 530 | mutex_lock(&read_mutex); |
99c18ce5 NP |
531 | memcpy(super, |
532 | cramfs_read(sb, 512, sizeof(*super)), | |
533 | sizeof(*super)); | |
353ab6e9 | 534 | mutex_unlock(&read_mutex); |
99c18ce5 NP |
535 | if (super->magic != CRAMFS_MAGIC) { |
536 | if (super->magic == CRAMFS_MAGIC_WEND && !silent) | |
e1ee7d85 | 537 | errorfc(fc, "wrong endianness"); |
ac8d35c5 | 538 | else if (!silent) |
e1ee7d85 | 539 | errorfc(fc, "wrong magic"); |
2309fb8e | 540 | return -EINVAL; |
1da177e4 LT |
541 | } |
542 | } | |
543 | ||
544 | /* get feature flags first */ | |
99c18ce5 | 545 | if (super->flags & ~CRAMFS_SUPPORTED_FLAGS) { |
e1ee7d85 | 546 | errorfc(fc, "unsupported filesystem features"); |
2309fb8e | 547 | return -EINVAL; |
1da177e4 LT |
548 | } |
549 | ||
550 | /* Check that the root inode is in a sane state */ | |
99c18ce5 | 551 | if (!S_ISDIR(super->root.mode)) { |
e1ee7d85 | 552 | errorfc(fc, "root is not a directory"); |
2309fb8e | 553 | return -EINVAL; |
1da177e4 | 554 | } |
6f772fe6 | 555 | /* correct strange, hard-coded permissions of mkcramfs */ |
99c18ce5 | 556 | super->root.mode |= 0555; |
6f772fe6 | 557 | |
99c18ce5 NP |
558 | root_offset = super->root.offset << 2; |
559 | if (super->flags & CRAMFS_FLAG_FSID_VERSION_2) { | |
560 | sbi->size = super->size; | |
561 | sbi->blocks = super->fsid.blocks; | |
562 | sbi->files = super->fsid.files; | |
1da177e4 | 563 | } else { |
31d92e55 FF |
564 | sbi->size = 1<<28; |
565 | sbi->blocks = 0; | |
566 | sbi->files = 0; | |
1da177e4 | 567 | } |
99c18ce5 NP |
568 | sbi->magic = super->magic; |
569 | sbi->flags = super->flags; | |
1da177e4 | 570 | if (root_offset == 0) |
e1ee7d85 | 571 | infofc(fc, "empty filesystem"); |
99c18ce5 | 572 | else if (!(super->flags & CRAMFS_FLAG_SHIFTED_ROOT_OFFSET) && |
1da177e4 LT |
573 | ((root_offset != sizeof(struct cramfs_super)) && |
574 | (root_offset != 512 + sizeof(struct cramfs_super)))) | |
575 | { | |
e1ee7d85 | 576 | errorfc(fc, "bad root offset %lu", root_offset); |
2309fb8e | 577 | return -EINVAL; |
1da177e4 LT |
578 | } |
579 | ||
99c18ce5 NP |
580 | return 0; |
581 | } | |
582 | ||
583 | static int cramfs_finalize_super(struct super_block *sb, | |
584 | struct cramfs_inode *cramfs_root) | |
585 | { | |
586 | struct inode *root; | |
587 | ||
1da177e4 | 588 | /* Set it all up.. */ |
1751e8a6 | 589 | sb->s_flags |= SB_RDONLY; |
22b13969 DD |
590 | sb->s_time_min = 0; |
591 | sb->s_time_max = 0; | |
1da177e4 | 592 | sb->s_op = &cramfs_ops; |
99c18ce5 | 593 | root = get_cramfs_inode(sb, cramfs_root, 0); |
0577d1ba | 594 | if (IS_ERR(root)) |
2309fb8e | 595 | return PTR_ERR(root); |
48fde701 AV |
596 | sb->s_root = d_make_root(root); |
597 | if (!sb->s_root) | |
2309fb8e | 598 | return -ENOMEM; |
1da177e4 | 599 | return 0; |
1da177e4 LT |
600 | } |
601 | ||
74f78fc5 | 602 | static int cramfs_blkdev_fill_super(struct super_block *sb, struct fs_context *fc) |
99c18ce5 NP |
603 | { |
604 | struct cramfs_sb_info *sbi; | |
605 | struct cramfs_super super; | |
606 | int i, err; | |
607 | ||
608 | sbi = kzalloc(sizeof(struct cramfs_sb_info), GFP_KERNEL); | |
609 | if (!sbi) | |
610 | return -ENOMEM; | |
611 | sb->s_fs_info = sbi; | |
612 | ||
613 | /* Invalidate the read buffers on mount: think disk change.. */ | |
614 | for (i = 0; i < READ_BUFFERS; i++) | |
615 | buffer_blocknr[i] = -1; | |
616 | ||
74f78fc5 | 617 | err = cramfs_read_super(sb, fc, &super); |
99c18ce5 NP |
618 | if (err) |
619 | return err; | |
620 | return cramfs_finalize_super(sb, &super.root); | |
621 | } | |
622 | ||
74f78fc5 | 623 | static int cramfs_mtd_fill_super(struct super_block *sb, struct fs_context *fc) |
99c18ce5 NP |
624 | { |
625 | struct cramfs_sb_info *sbi; | |
626 | struct cramfs_super super; | |
627 | int err; | |
628 | ||
629 | sbi = kzalloc(sizeof(struct cramfs_sb_info), GFP_KERNEL); | |
630 | if (!sbi) | |
631 | return -ENOMEM; | |
632 | sb->s_fs_info = sbi; | |
633 | ||
634 | /* Map only one page for now. Will remap it when fs size is known. */ | |
635 | err = mtd_point(sb->s_mtd, 0, PAGE_SIZE, &sbi->mtd_point_size, | |
636 | &sbi->linear_virt_addr, &sbi->linear_phys_addr); | |
637 | if (err || sbi->mtd_point_size != PAGE_SIZE) { | |
638 | pr_err("unable to get direct memory access to mtd:%s\n", | |
639 | sb->s_mtd->name); | |
640 | return err ? : -ENODATA; | |
641 | } | |
642 | ||
643 | pr_info("checking physical address %pap for linear cramfs image\n", | |
644 | &sbi->linear_phys_addr); | |
74f78fc5 | 645 | err = cramfs_read_super(sb, fc, &super); |
99c18ce5 NP |
646 | if (err) |
647 | return err; | |
648 | ||
649 | /* Remap the whole filesystem now */ | |
650 | pr_info("linear cramfs image on mtd:%s appears to be %lu KB in size\n", | |
651 | sb->s_mtd->name, sbi->size/1024); | |
652 | mtd_unpoint(sb->s_mtd, 0, PAGE_SIZE); | |
653 | err = mtd_point(sb->s_mtd, 0, sbi->size, &sbi->mtd_point_size, | |
654 | &sbi->linear_virt_addr, &sbi->linear_phys_addr); | |
655 | if (err || sbi->mtd_point_size != sbi->size) { | |
656 | pr_err("unable to get direct memory access to mtd:%s\n", | |
657 | sb->s_mtd->name); | |
658 | return err ? : -ENODATA; | |
659 | } | |
660 | ||
661 | return cramfs_finalize_super(sb, &super.root); | |
662 | } | |
663 | ||
726c3342 | 664 | static int cramfs_statfs(struct dentry *dentry, struct kstatfs *buf) |
1da177e4 | 665 | { |
726c3342 | 666 | struct super_block *sb = dentry->d_sb; |
99c18ce5 NP |
667 | u64 id = 0; |
668 | ||
669 | if (sb->s_bdev) | |
670 | id = huge_encode_dev(sb->s_bdev->bd_dev); | |
671 | else if (sb->s_dev) | |
672 | id = huge_encode_dev(sb->s_dev); | |
726c3342 | 673 | |
1da177e4 | 674 | buf->f_type = CRAMFS_MAGIC; |
09cbfeaf | 675 | buf->f_bsize = PAGE_SIZE; |
1da177e4 LT |
676 | buf->f_blocks = CRAMFS_SB(sb)->blocks; |
677 | buf->f_bfree = 0; | |
678 | buf->f_bavail = 0; | |
679 | buf->f_files = CRAMFS_SB(sb)->files; | |
680 | buf->f_ffree = 0; | |
6d1349c7 | 681 | buf->f_fsid = u64_to_fsid(id); |
1da177e4 LT |
682 | buf->f_namelen = CRAMFS_MAXPATHLEN; |
683 | return 0; | |
684 | } | |
685 | ||
686 | /* | |
687 | * Read a cramfs directory entry. | |
688 | */ | |
6f7f231e | 689 | static int cramfs_readdir(struct file *file, struct dir_context *ctx) |
1da177e4 | 690 | { |
6f7f231e | 691 | struct inode *inode = file_inode(file); |
1da177e4 LT |
692 | struct super_block *sb = inode->i_sb; |
693 | char *buf; | |
694 | unsigned int offset; | |
1da177e4 LT |
695 | |
696 | /* Offset within the thing. */ | |
6f7f231e | 697 | if (ctx->pos >= inode->i_size) |
1da177e4 | 698 | return 0; |
6f7f231e | 699 | offset = ctx->pos; |
1da177e4 LT |
700 | /* Directory entries are always 4-byte aligned */ |
701 | if (offset & 3) | |
702 | return -EINVAL; | |
703 | ||
4176ed59 | 704 | buf = kmalloc(CRAMFS_MAXPATHLEN, GFP_KERNEL); |
1da177e4 LT |
705 | if (!buf) |
706 | return -ENOMEM; | |
707 | ||
1da177e4 LT |
708 | while (offset < inode->i_size) { |
709 | struct cramfs_inode *de; | |
710 | unsigned long nextoffset; | |
711 | char *name; | |
712 | ino_t ino; | |
175a4eb7 | 713 | umode_t mode; |
6f7f231e | 714 | int namelen; |
1da177e4 | 715 | |
353ab6e9 | 716 | mutex_lock(&read_mutex); |
4176ed59 | 717 | de = cramfs_read(sb, OFFSET(inode) + offset, sizeof(*de)+CRAMFS_MAXPATHLEN); |
1da177e4 LT |
718 | name = (char *)(de+1); |
719 | ||
720 | /* | |
721 | * Namelengths on disk are shifted by two | |
722 | * and the name padded out to 4-byte boundaries | |
723 | * with zeroes. | |
724 | */ | |
725 | namelen = de->namelen << 2; | |
726 | memcpy(buf, name, namelen); | |
6f772fe6 | 727 | ino = cramino(de, OFFSET(inode) + offset); |
1da177e4 | 728 | mode = de->mode; |
353ab6e9 | 729 | mutex_unlock(&read_mutex); |
1da177e4 LT |
730 | nextoffset = offset + sizeof(*de) + namelen; |
731 | for (;;) { | |
732 | if (!namelen) { | |
733 | kfree(buf); | |
734 | return -EIO; | |
735 | } | |
736 | if (buf[namelen-1]) | |
737 | break; | |
738 | namelen--; | |
739 | } | |
6f7f231e | 740 | if (!dir_emit(ctx, buf, namelen, ino, mode >> 12)) |
1da177e4 LT |
741 | break; |
742 | ||
6f7f231e | 743 | ctx->pos = offset = nextoffset; |
1da177e4 LT |
744 | } |
745 | kfree(buf); | |
746 | return 0; | |
747 | } | |
748 | ||
749 | /* | |
750 | * Lookup and fill in the inode data.. | |
751 | */ | |
31d92e55 | 752 | static struct dentry *cramfs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) |
1da177e4 LT |
753 | { |
754 | unsigned int offset = 0; | |
0577d1ba | 755 | struct inode *inode = NULL; |
1da177e4 LT |
756 | int sorted; |
757 | ||
353ab6e9 | 758 | mutex_lock(&read_mutex); |
1da177e4 LT |
759 | sorted = CRAMFS_SB(dir->i_sb)->flags & CRAMFS_FLAG_SORTED_DIRS; |
760 | while (offset < dir->i_size) { | |
761 | struct cramfs_inode *de; | |
762 | char *name; | |
763 | int namelen, retval; | |
6f772fe6 | 764 | int dir_off = OFFSET(dir) + offset; |
1da177e4 | 765 | |
6f772fe6 | 766 | de = cramfs_read(dir->i_sb, dir_off, sizeof(*de)+CRAMFS_MAXPATHLEN); |
1da177e4 LT |
767 | name = (char *)(de+1); |
768 | ||
769 | /* Try to take advantage of sorted directories */ | |
770 | if (sorted && (dentry->d_name.name[0] < name[0])) | |
771 | break; | |
772 | ||
773 | namelen = de->namelen << 2; | |
774 | offset += sizeof(*de) + namelen; | |
775 | ||
776 | /* Quick check that the name is roughly the right length */ | |
777 | if (((dentry->d_name.len + 3) & ~3) != namelen) | |
778 | continue; | |
779 | ||
780 | for (;;) { | |
781 | if (!namelen) { | |
0577d1ba AV |
782 | inode = ERR_PTR(-EIO); |
783 | goto out; | |
1da177e4 LT |
784 | } |
785 | if (name[namelen-1]) | |
786 | break; | |
787 | namelen--; | |
788 | } | |
789 | if (namelen != dentry->d_name.len) | |
790 | continue; | |
791 | retval = memcmp(dentry->d_name.name, name, namelen); | |
792 | if (retval > 0) | |
793 | continue; | |
794 | if (!retval) { | |
0577d1ba AV |
795 | inode = get_cramfs_inode(dir->i_sb, de, dir_off); |
796 | break; | |
1da177e4 LT |
797 | } |
798 | /* else (retval < 0) */ | |
799 | if (sorted) | |
800 | break; | |
801 | } | |
0577d1ba | 802 | out: |
353ab6e9 | 803 | mutex_unlock(&read_mutex); |
d023b3a1 | 804 | return d_splice_alias(inode, dentry); |
1da177e4 LT |
805 | } |
806 | ||
5aab331a | 807 | static int cramfs_read_folio(struct file *file, struct folio *folio) |
1da177e4 | 808 | { |
5aab331a | 809 | struct page *page = &folio->page; |
1da177e4 | 810 | struct inode *inode = page->mapping->host; |
98310e58 DV |
811 | u32 maxblock; |
812 | int bytes_filled; | |
1da177e4 LT |
813 | void *pgdata; |
814 | ||
09cbfeaf | 815 | maxblock = (inode->i_size + PAGE_SIZE - 1) >> PAGE_SHIFT; |
1da177e4 | 816 | bytes_filled = 0; |
f27c942e | 817 | pgdata = kmap_local_page(page); |
98310e58 | 818 | |
1da177e4 LT |
819 | if (page->index < maxblock) { |
820 | struct super_block *sb = inode->i_sb; | |
fd4f6f2a NP |
821 | u32 blkptr_offset = OFFSET(inode) + page->index * 4; |
822 | u32 block_ptr, block_start, block_len; | |
823 | bool uncompressed, direct; | |
1da177e4 | 824 | |
353ab6e9 | 825 | mutex_lock(&read_mutex); |
fd4f6f2a NP |
826 | block_ptr = *(u32 *) cramfs_read(sb, blkptr_offset, 4); |
827 | uncompressed = (block_ptr & CRAMFS_BLK_FLAG_UNCOMPRESSED); | |
828 | direct = (block_ptr & CRAMFS_BLK_FLAG_DIRECT_PTR); | |
829 | block_ptr &= ~CRAMFS_BLK_FLAGS; | |
830 | ||
831 | if (direct) { | |
832 | /* | |
833 | * The block pointer is an absolute start pointer, | |
834 | * shifted by 2 bits. The size is included in the | |
835 | * first 2 bytes of the data block when compressed, | |
836 | * or PAGE_SIZE otherwise. | |
837 | */ | |
838 | block_start = block_ptr << CRAMFS_BLK_DIRECT_PTR_SHIFT; | |
839 | if (uncompressed) { | |
840 | block_len = PAGE_SIZE; | |
841 | /* if last block: cap to file length */ | |
842 | if (page->index == maxblock - 1) | |
843 | block_len = | |
844 | offset_in_page(inode->i_size); | |
845 | } else { | |
846 | block_len = *(u16 *) | |
847 | cramfs_read(sb, block_start, 2); | |
848 | block_start += 2; | |
849 | } | |
850 | } else { | |
851 | /* | |
852 | * The block pointer indicates one past the end of | |
853 | * the current block (start of next block). If this | |
854 | * is the first block then it starts where the block | |
855 | * pointer table ends, otherwise its start comes | |
856 | * from the previous block's pointer. | |
857 | */ | |
858 | block_start = OFFSET(inode) + maxblock * 4; | |
859 | if (page->index) | |
860 | block_start = *(u32 *) | |
861 | cramfs_read(sb, blkptr_offset - 4, 4); | |
862 | /* Beware... previous ptr might be a direct ptr */ | |
863 | if (unlikely(block_start & CRAMFS_BLK_FLAG_DIRECT_PTR)) { | |
864 | /* See comments on earlier code. */ | |
865 | u32 prev_start = block_start; | |
56ce68bc NP |
866 | block_start = prev_start & ~CRAMFS_BLK_FLAGS; |
867 | block_start <<= CRAMFS_BLK_DIRECT_PTR_SHIFT; | |
fd4f6f2a NP |
868 | if (prev_start & CRAMFS_BLK_FLAG_UNCOMPRESSED) { |
869 | block_start += PAGE_SIZE; | |
870 | } else { | |
871 | block_len = *(u16 *) | |
872 | cramfs_read(sb, block_start, 2); | |
873 | block_start += 2 + block_len; | |
874 | } | |
875 | } | |
876 | block_start &= ~CRAMFS_BLK_FLAGS; | |
877 | block_len = block_ptr - block_start; | |
878 | } | |
98310e58 | 879 | |
fd4f6f2a | 880 | if (block_len == 0) |
1da177e4 | 881 | ; /* hole */ |
fd4f6f2a NP |
882 | else if (unlikely(block_len > 2*PAGE_SIZE || |
883 | (uncompressed && block_len > PAGE_SIZE))) { | |
884 | mutex_unlock(&read_mutex); | |
885 | pr_err("bad data blocksize %u\n", block_len); | |
98310e58 | 886 | goto err; |
fd4f6f2a NP |
887 | } else if (uncompressed) { |
888 | memcpy(pgdata, | |
889 | cramfs_read(sb, block_start, block_len), | |
890 | block_len); | |
891 | bytes_filled = block_len; | |
98310e58 | 892 | } else { |
1da177e4 | 893 | bytes_filled = cramfs_uncompress_block(pgdata, |
09cbfeaf | 894 | PAGE_SIZE, |
fd4f6f2a NP |
895 | cramfs_read(sb, block_start, block_len), |
896 | block_len); | |
1da177e4 | 897 | } |
fd4f6f2a NP |
898 | mutex_unlock(&read_mutex); |
899 | if (unlikely(bytes_filled < 0)) | |
900 | goto err; | |
98310e58 DV |
901 | } |
902 | ||
09cbfeaf | 903 | memset(pgdata + bytes_filled, 0, PAGE_SIZE - bytes_filled); |
1da177e4 | 904 | flush_dcache_page(page); |
f27c942e | 905 | kunmap_local(pgdata); |
1da177e4 LT |
906 | SetPageUptodate(page); |
907 | unlock_page(page); | |
908 | return 0; | |
98310e58 DV |
909 | |
910 | err: | |
f27c942e | 911 | kunmap_local(pgdata); |
98310e58 DV |
912 | ClearPageUptodate(page); |
913 | SetPageError(page); | |
914 | unlock_page(page); | |
915 | return 0; | |
1da177e4 LT |
916 | } |
917 | ||
f5e54d6e | 918 | static const struct address_space_operations cramfs_aops = { |
5aab331a | 919 | .read_folio = cramfs_read_folio |
1da177e4 LT |
920 | }; |
921 | ||
922 | /* | |
923 | * Our operations: | |
924 | */ | |
925 | ||
926 | /* | |
927 | * A directory can only readdir | |
928 | */ | |
4b6f5d20 | 929 | static const struct file_operations cramfs_directory_operations = { |
1da177e4 LT |
930 | .llseek = generic_file_llseek, |
931 | .read = generic_read_dir, | |
c51da20c | 932 | .iterate_shared = cramfs_readdir, |
1da177e4 LT |
933 | }; |
934 | ||
754661f1 | 935 | static const struct inode_operations cramfs_dir_inode_operations = { |
1da177e4 LT |
936 | .lookup = cramfs_lookup, |
937 | }; | |
938 | ||
ee9b6d61 | 939 | static const struct super_operations cramfs_ops = { |
1da177e4 LT |
940 | .statfs = cramfs_statfs, |
941 | }; | |
942 | ||
74f78fc5 | 943 | static int cramfs_get_tree(struct fs_context *fc) |
1da177e4 | 944 | { |
74f78fc5 | 945 | int ret = -ENOPROTOOPT; |
99c18ce5 NP |
946 | |
947 | if (IS_ENABLED(CONFIG_CRAMFS_MTD)) { | |
74f78fc5 | 948 | ret = get_tree_mtd(fc, cramfs_mtd_fill_super); |
3e5aeec0 MB |
949 | if (!ret) |
950 | return 0; | |
99c18ce5 | 951 | } |
74f78fc5 DH |
952 | if (IS_ENABLED(CONFIG_CRAMFS_BLOCKDEV)) |
953 | ret = get_tree_bdev(fc, cramfs_blkdev_fill_super); | |
99c18ce5 | 954 | return ret; |
1da177e4 LT |
955 | } |
956 | ||
74f78fc5 DH |
957 | static const struct fs_context_operations cramfs_context_ops = { |
958 | .get_tree = cramfs_get_tree, | |
959 | .reconfigure = cramfs_reconfigure, | |
960 | }; | |
961 | ||
962 | /* | |
963 | * Set up the filesystem mount context. | |
964 | */ | |
965 | static int cramfs_init_fs_context(struct fs_context *fc) | |
966 | { | |
967 | fc->ops = &cramfs_context_ops; | |
968 | return 0; | |
969 | } | |
970 | ||
1da177e4 LT |
971 | static struct file_system_type cramfs_fs_type = { |
972 | .owner = THIS_MODULE, | |
973 | .name = "cramfs", | |
74f78fc5 | 974 | .init_fs_context = cramfs_init_fs_context, |
2309fb8e | 975 | .kill_sb = cramfs_kill_sb, |
1da177e4 LT |
976 | .fs_flags = FS_REQUIRES_DEV, |
977 | }; | |
7f78e035 | 978 | MODULE_ALIAS_FS("cramfs"); |
1da177e4 LT |
979 | |
980 | static int __init init_cramfs_fs(void) | |
981 | { | |
50d44ed0 AD |
982 | int rv; |
983 | ||
984 | rv = cramfs_uncompress_init(); | |
985 | if (rv < 0) | |
986 | return rv; | |
987 | rv = register_filesystem(&cramfs_fs_type); | |
988 | if (rv < 0) | |
989 | cramfs_uncompress_exit(); | |
990 | return rv; | |
1da177e4 LT |
991 | } |
992 | ||
993 | static void __exit exit_cramfs_fs(void) | |
994 | { | |
995 | cramfs_uncompress_exit(); | |
996 | unregister_filesystem(&cramfs_fs_type); | |
997 | } | |
998 | ||
999 | module_init(init_cramfs_fs) | |
1000 | module_exit(exit_cramfs_fs) | |
1001 | MODULE_LICENSE("GPL"); |