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; | |
cf948cbc | 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) { |
09cbfeaf | 241 | memcpy(data, kmap(page), PAGE_SIZE); |
1da177e4 | 242 | kunmap(page); |
09cbfeaf | 243 | put_page(page); |
1da177e4 | 244 | } else |
09cbfeaf KS |
245 | memset(data, 0, PAGE_SIZE); |
246 | data += PAGE_SIZE; | |
1da177e4 LT |
247 | } |
248 | return read_buffers[buffer] + offset; | |
249 | } | |
250 | ||
99c18ce5 NP |
251 | /* |
252 | * Return a pointer to the linearly addressed cramfs image in memory. | |
253 | */ | |
254 | static void *cramfs_direct_read(struct super_block *sb, unsigned int offset, | |
255 | unsigned int len) | |
256 | { | |
257 | struct cramfs_sb_info *sbi = CRAMFS_SB(sb); | |
258 | ||
259 | if (!len) | |
260 | return NULL; | |
261 | if (len > sbi->size || offset > sbi->size - len) | |
262 | return page_address(ZERO_PAGE(0)); | |
263 | return sbi->linear_virt_addr + offset; | |
264 | } | |
265 | ||
266 | /* | |
267 | * Returns a pointer to a buffer containing at least LEN bytes of | |
268 | * filesystem starting at byte offset OFFSET into the filesystem. | |
269 | */ | |
270 | static void *cramfs_read(struct super_block *sb, unsigned int offset, | |
271 | unsigned int len) | |
272 | { | |
273 | struct cramfs_sb_info *sbi = CRAMFS_SB(sb); | |
274 | ||
275 | if (IS_ENABLED(CONFIG_CRAMFS_MTD) && sbi->linear_virt_addr) | |
276 | return cramfs_direct_read(sb, offset, len); | |
277 | else if (IS_ENABLED(CONFIG_CRAMFS_BLOCKDEV)) | |
278 | return cramfs_blkdev_read(sb, offset, len); | |
279 | else | |
280 | return NULL; | |
281 | } | |
282 | ||
eddcd976 NP |
283 | /* |
284 | * For a mapping to be possible, we need a range of uncompressed and | |
285 | * contiguous blocks. Return the offset for the first block and number of | |
286 | * valid blocks for which that is true, or zero otherwise. | |
287 | */ | |
288 | static u32 cramfs_get_block_range(struct inode *inode, u32 pgoff, u32 *pages) | |
289 | { | |
290 | struct cramfs_sb_info *sbi = CRAMFS_SB(inode->i_sb); | |
291 | int i; | |
292 | u32 *blockptrs, first_block_addr; | |
293 | ||
294 | /* | |
295 | * We can dereference memory directly here as this code may be | |
296 | * reached only when there is a direct filesystem image mapping | |
297 | * available in memory. | |
298 | */ | |
299 | blockptrs = (u32 *)(sbi->linear_virt_addr + OFFSET(inode) + pgoff * 4); | |
300 | first_block_addr = blockptrs[0] & ~CRAMFS_BLK_FLAGS; | |
301 | i = 0; | |
302 | do { | |
303 | u32 block_off = i * (PAGE_SIZE >> CRAMFS_BLK_DIRECT_PTR_SHIFT); | |
304 | u32 expect = (first_block_addr + block_off) | | |
305 | CRAMFS_BLK_FLAG_DIRECT_PTR | | |
306 | CRAMFS_BLK_FLAG_UNCOMPRESSED; | |
307 | if (blockptrs[i] != expect) { | |
308 | pr_debug("range: block %d/%d got %#x expects %#x\n", | |
309 | pgoff+i, pgoff + *pages - 1, | |
310 | blockptrs[i], expect); | |
311 | if (i == 0) | |
312 | return 0; | |
313 | break; | |
314 | } | |
315 | } while (++i < *pages); | |
316 | ||
317 | *pages = i; | |
318 | return first_block_addr << CRAMFS_BLK_DIRECT_PTR_SHIFT; | |
319 | } | |
320 | ||
321 | #ifdef CONFIG_MMU | |
322 | ||
323 | /* | |
324 | * Return true if the last page of a file in the filesystem image contains | |
325 | * some other data that doesn't belong to that file. It is assumed that the | |
326 | * last block is CRAMFS_BLK_FLAG_DIRECT_PTR | CRAMFS_BLK_FLAG_UNCOMPRESSED | |
327 | * (verified by cramfs_get_block_range() and directly accessible in memory. | |
328 | */ | |
329 | static bool cramfs_last_page_is_shared(struct inode *inode) | |
330 | { | |
331 | struct cramfs_sb_info *sbi = CRAMFS_SB(inode->i_sb); | |
332 | u32 partial, last_page, blockaddr, *blockptrs; | |
333 | char *tail_data; | |
334 | ||
335 | partial = offset_in_page(inode->i_size); | |
336 | if (!partial) | |
337 | return false; | |
338 | last_page = inode->i_size >> PAGE_SHIFT; | |
339 | blockptrs = (u32 *)(sbi->linear_virt_addr + OFFSET(inode)); | |
340 | blockaddr = blockptrs[last_page] & ~CRAMFS_BLK_FLAGS; | |
341 | blockaddr <<= CRAMFS_BLK_DIRECT_PTR_SHIFT; | |
342 | tail_data = sbi->linear_virt_addr + blockaddr + partial; | |
343 | return memchr_inv(tail_data, 0, PAGE_SIZE - partial) ? true : false; | |
344 | } | |
345 | ||
346 | static int cramfs_physmem_mmap(struct file *file, struct vm_area_struct *vma) | |
347 | { | |
348 | struct inode *inode = file_inode(file); | |
349 | struct cramfs_sb_info *sbi = CRAMFS_SB(inode->i_sb); | |
350 | unsigned int pages, max_pages, offset; | |
351 | unsigned long address, pgoff = vma->vm_pgoff; | |
352 | char *bailout_reason; | |
353 | int ret; | |
354 | ||
355 | ret = generic_file_readonly_mmap(file, vma); | |
356 | if (ret) | |
357 | return ret; | |
358 | ||
359 | /* | |
360 | * Now try to pre-populate ptes for this vma with a direct | |
361 | * mapping avoiding memory allocation when possible. | |
362 | */ | |
363 | ||
364 | /* Could COW work here? */ | |
365 | bailout_reason = "vma is writable"; | |
366 | if (vma->vm_flags & VM_WRITE) | |
367 | goto bailout; | |
368 | ||
369 | max_pages = (inode->i_size + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
370 | bailout_reason = "beyond file limit"; | |
371 | if (pgoff >= max_pages) | |
372 | goto bailout; | |
373 | pages = min(vma_pages(vma), max_pages - pgoff); | |
374 | ||
375 | offset = cramfs_get_block_range(inode, pgoff, &pages); | |
376 | bailout_reason = "unsuitable block layout"; | |
377 | if (!offset) | |
378 | goto bailout; | |
379 | address = sbi->linear_phys_addr + offset; | |
380 | bailout_reason = "data is not page aligned"; | |
381 | if (!PAGE_ALIGNED(address)) | |
382 | goto bailout; | |
383 | ||
384 | /* Don't map the last page if it contains some other data */ | |
385 | if (pgoff + pages == max_pages && cramfs_last_page_is_shared(inode)) { | |
aa7d5c7e | 386 | pr_debug("mmap: %pD: last page is shared\n", file); |
eddcd976 NP |
387 | pages--; |
388 | } | |
389 | ||
390 | if (!pages) { | |
391 | bailout_reason = "no suitable block remaining"; | |
392 | goto bailout; | |
393 | } | |
394 | ||
395 | if (pages == vma_pages(vma)) { | |
396 | /* | |
397 | * The entire vma is mappable. remap_pfn_range() will | |
398 | * make it distinguishable from a non-direct mapping | |
399 | * in /proc/<pid>/maps by substituting the file offset | |
400 | * with the actual physical address. | |
401 | */ | |
402 | ret = remap_pfn_range(vma, vma->vm_start, address >> PAGE_SHIFT, | |
403 | pages * PAGE_SIZE, vma->vm_page_prot); | |
404 | } else { | |
405 | /* | |
406 | * Let's create a mixed map if we can't map it all. | |
407 | * The normal paging machinery will take care of the | |
5aab331a | 408 | * unpopulated ptes via cramfs_read_folio(). |
eddcd976 NP |
409 | */ |
410 | int i; | |
411 | vma->vm_flags |= VM_MIXEDMAP; | |
412 | for (i = 0; i < pages && !ret; i++) { | |
7f2764cf | 413 | vm_fault_t vmf; |
eddcd976 NP |
414 | unsigned long off = i * PAGE_SIZE; |
415 | pfn_t pfn = phys_to_pfn_t(address + off, PFN_DEV); | |
7f2764cf NP |
416 | vmf = vmf_insert_mixed(vma, vma->vm_start + off, pfn); |
417 | if (vmf & VM_FAULT_ERROR) | |
418 | ret = vm_fault_to_errno(vmf, 0); | |
eddcd976 NP |
419 | } |
420 | } | |
421 | ||
422 | if (!ret) | |
aa7d5c7e AV |
423 | pr_debug("mapped %pD[%lu] at 0x%08lx (%u/%lu pages) " |
424 | "to vma 0x%08lx, page_prot 0x%llx\n", file, | |
425 | pgoff, address, pages, vma_pages(vma), vma->vm_start, | |
eddcd976 NP |
426 | (unsigned long long)pgprot_val(vma->vm_page_prot)); |
427 | return ret; | |
428 | ||
429 | bailout: | |
aa7d5c7e AV |
430 | pr_debug("%pD[%lu]: direct mmap impossible: %s\n", |
431 | file, pgoff, bailout_reason); | |
eddcd976 NP |
432 | /* Didn't manage any direct map, but normal paging is still possible */ |
433 | return 0; | |
434 | } | |
435 | ||
436 | #else /* CONFIG_MMU */ | |
437 | ||
438 | static int cramfs_physmem_mmap(struct file *file, struct vm_area_struct *vma) | |
439 | { | |
440 | return vma->vm_flags & (VM_SHARED | VM_MAYSHARE) ? 0 : -ENOSYS; | |
441 | } | |
442 | ||
443 | static unsigned long cramfs_physmem_get_unmapped_area(struct file *file, | |
444 | unsigned long addr, unsigned long len, | |
445 | unsigned long pgoff, unsigned long flags) | |
446 | { | |
447 | struct inode *inode = file_inode(file); | |
448 | struct super_block *sb = inode->i_sb; | |
449 | struct cramfs_sb_info *sbi = CRAMFS_SB(sb); | |
450 | unsigned int pages, block_pages, max_pages, offset; | |
451 | ||
452 | pages = (len + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
453 | max_pages = (inode->i_size + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
454 | if (pgoff >= max_pages || pages > max_pages - pgoff) | |
455 | return -EINVAL; | |
456 | block_pages = pages; | |
457 | offset = cramfs_get_block_range(inode, pgoff, &block_pages); | |
458 | if (!offset || block_pages != pages) | |
459 | return -ENOSYS; | |
460 | addr = sbi->linear_phys_addr + offset; | |
aa7d5c7e AV |
461 | pr_debug("get_unmapped for %pD ofs %#lx siz %lu at 0x%08lx\n", |
462 | file, pgoff*PAGE_SIZE, len, addr); | |
eddcd976 NP |
463 | return addr; |
464 | } | |
465 | ||
466 | static unsigned int cramfs_physmem_mmap_capabilities(struct file *file) | |
467 | { | |
468 | return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | | |
469 | NOMMU_MAP_READ | NOMMU_MAP_EXEC; | |
470 | } | |
471 | ||
472 | #endif /* CONFIG_MMU */ | |
473 | ||
474 | static const struct file_operations cramfs_physmem_fops = { | |
475 | .llseek = generic_file_llseek, | |
476 | .read_iter = generic_file_read_iter, | |
477 | .splice_read = generic_file_splice_read, | |
478 | .mmap = cramfs_physmem_mmap, | |
479 | #ifndef CONFIG_MMU | |
480 | .get_unmapped_area = cramfs_physmem_get_unmapped_area, | |
481 | .mmap_capabilities = cramfs_physmem_mmap_capabilities, | |
482 | #endif | |
483 | }; | |
484 | ||
2309fb8e | 485 | static void cramfs_kill_sb(struct super_block *sb) |
1da177e4 | 486 | { |
f7f4f4dd | 487 | struct cramfs_sb_info *sbi = CRAMFS_SB(sb); |
31d92e55 | 488 | |
08a8f308 | 489 | if (IS_ENABLED(CONFIG_CRAMFS_MTD) && sb->s_mtd) { |
99c18ce5 NP |
490 | if (sbi && sbi->mtd_point_size) |
491 | mtd_unpoint(sb->s_mtd, 0, sbi->mtd_point_size); | |
492 | kill_mtd_super(sb); | |
493 | } else if (IS_ENABLED(CONFIG_CRAMFS_BLOCKDEV) && sb->s_bdev) { | |
494 | kill_block_super(sb); | |
495 | } | |
2309fb8e | 496 | kfree(sbi); |
1da177e4 LT |
497 | } |
498 | ||
74f78fc5 | 499 | static int cramfs_reconfigure(struct fs_context *fc) |
1da177e4 | 500 | { |
74f78fc5 DH |
501 | sync_filesystem(fc->root->d_sb); |
502 | fc->sb_flags |= SB_RDONLY; | |
1da177e4 LT |
503 | return 0; |
504 | } | |
505 | ||
74f78fc5 DH |
506 | static int cramfs_read_super(struct super_block *sb, struct fs_context *fc, |
507 | struct cramfs_super *super) | |
1da177e4 | 508 | { |
99c18ce5 | 509 | struct cramfs_sb_info *sbi = CRAMFS_SB(sb); |
1da177e4 | 510 | unsigned long root_offset; |
74f78fc5 | 511 | bool silent = fc->sb_flags & SB_SILENT; |
1da177e4 | 512 | |
99c18ce5 NP |
513 | /* We don't know the real size yet */ |
514 | sbi->size = PAGE_SIZE; | |
1da177e4 LT |
515 | |
516 | /* Read the first block and get the superblock from it */ | |
99c18ce5 NP |
517 | mutex_lock(&read_mutex); |
518 | memcpy(super, cramfs_read(sb, 0, sizeof(*super)), sizeof(*super)); | |
353ab6e9 | 519 | mutex_unlock(&read_mutex); |
1da177e4 LT |
520 | |
521 | /* Do sanity checks on the superblock */ | |
99c18ce5 | 522 | if (super->magic != CRAMFS_MAGIC) { |
0cc785ec | 523 | /* check for wrong endianness */ |
99c18ce5 | 524 | if (super->magic == CRAMFS_MAGIC_WEND) { |
ac8d35c5 | 525 | if (!silent) |
e1ee7d85 | 526 | errorfc(fc, "wrong endianness"); |
2309fb8e | 527 | return -EINVAL; |
ac8d35c5 AD |
528 | } |
529 | ||
1da177e4 | 530 | /* check at 512 byte offset */ |
353ab6e9 | 531 | mutex_lock(&read_mutex); |
99c18ce5 NP |
532 | memcpy(super, |
533 | cramfs_read(sb, 512, sizeof(*super)), | |
534 | sizeof(*super)); | |
353ab6e9 | 535 | mutex_unlock(&read_mutex); |
99c18ce5 NP |
536 | if (super->magic != CRAMFS_MAGIC) { |
537 | if (super->magic == CRAMFS_MAGIC_WEND && !silent) | |
e1ee7d85 | 538 | errorfc(fc, "wrong endianness"); |
ac8d35c5 | 539 | else if (!silent) |
e1ee7d85 | 540 | errorfc(fc, "wrong magic"); |
2309fb8e | 541 | return -EINVAL; |
1da177e4 LT |
542 | } |
543 | } | |
544 | ||
545 | /* get feature flags first */ | |
99c18ce5 | 546 | if (super->flags & ~CRAMFS_SUPPORTED_FLAGS) { |
e1ee7d85 | 547 | errorfc(fc, "unsupported filesystem features"); |
2309fb8e | 548 | return -EINVAL; |
1da177e4 LT |
549 | } |
550 | ||
551 | /* Check that the root inode is in a sane state */ | |
99c18ce5 | 552 | if (!S_ISDIR(super->root.mode)) { |
e1ee7d85 | 553 | errorfc(fc, "root is not a directory"); |
2309fb8e | 554 | return -EINVAL; |
1da177e4 | 555 | } |
6f772fe6 | 556 | /* correct strange, hard-coded permissions of mkcramfs */ |
99c18ce5 | 557 | super->root.mode |= 0555; |
6f772fe6 | 558 | |
99c18ce5 NP |
559 | root_offset = super->root.offset << 2; |
560 | if (super->flags & CRAMFS_FLAG_FSID_VERSION_2) { | |
561 | sbi->size = super->size; | |
562 | sbi->blocks = super->fsid.blocks; | |
563 | sbi->files = super->fsid.files; | |
1da177e4 | 564 | } else { |
31d92e55 FF |
565 | sbi->size = 1<<28; |
566 | sbi->blocks = 0; | |
567 | sbi->files = 0; | |
1da177e4 | 568 | } |
99c18ce5 NP |
569 | sbi->magic = super->magic; |
570 | sbi->flags = super->flags; | |
1da177e4 | 571 | if (root_offset == 0) |
e1ee7d85 | 572 | infofc(fc, "empty filesystem"); |
99c18ce5 | 573 | else if (!(super->flags & CRAMFS_FLAG_SHIFTED_ROOT_OFFSET) && |
1da177e4 LT |
574 | ((root_offset != sizeof(struct cramfs_super)) && |
575 | (root_offset != 512 + sizeof(struct cramfs_super)))) | |
576 | { | |
e1ee7d85 | 577 | errorfc(fc, "bad root offset %lu", root_offset); |
2309fb8e | 578 | return -EINVAL; |
1da177e4 LT |
579 | } |
580 | ||
99c18ce5 NP |
581 | return 0; |
582 | } | |
583 | ||
584 | static int cramfs_finalize_super(struct super_block *sb, | |
585 | struct cramfs_inode *cramfs_root) | |
586 | { | |
587 | struct inode *root; | |
588 | ||
1da177e4 | 589 | /* Set it all up.. */ |
1751e8a6 | 590 | sb->s_flags |= SB_RDONLY; |
22b13969 DD |
591 | sb->s_time_min = 0; |
592 | sb->s_time_max = 0; | |
1da177e4 | 593 | sb->s_op = &cramfs_ops; |
99c18ce5 | 594 | root = get_cramfs_inode(sb, cramfs_root, 0); |
0577d1ba | 595 | if (IS_ERR(root)) |
2309fb8e | 596 | return PTR_ERR(root); |
48fde701 AV |
597 | sb->s_root = d_make_root(root); |
598 | if (!sb->s_root) | |
2309fb8e | 599 | return -ENOMEM; |
1da177e4 | 600 | return 0; |
1da177e4 LT |
601 | } |
602 | ||
74f78fc5 | 603 | static int cramfs_blkdev_fill_super(struct super_block *sb, struct fs_context *fc) |
99c18ce5 NP |
604 | { |
605 | struct cramfs_sb_info *sbi; | |
606 | struct cramfs_super super; | |
607 | int i, err; | |
608 | ||
609 | sbi = kzalloc(sizeof(struct cramfs_sb_info), GFP_KERNEL); | |
610 | if (!sbi) | |
611 | return -ENOMEM; | |
612 | sb->s_fs_info = sbi; | |
613 | ||
614 | /* Invalidate the read buffers on mount: think disk change.. */ | |
615 | for (i = 0; i < READ_BUFFERS; i++) | |
616 | buffer_blocknr[i] = -1; | |
617 | ||
74f78fc5 | 618 | err = cramfs_read_super(sb, fc, &super); |
99c18ce5 NP |
619 | if (err) |
620 | return err; | |
621 | return cramfs_finalize_super(sb, &super.root); | |
622 | } | |
623 | ||
74f78fc5 | 624 | static int cramfs_mtd_fill_super(struct super_block *sb, struct fs_context *fc) |
99c18ce5 NP |
625 | { |
626 | struct cramfs_sb_info *sbi; | |
627 | struct cramfs_super super; | |
628 | int err; | |
629 | ||
630 | sbi = kzalloc(sizeof(struct cramfs_sb_info), GFP_KERNEL); | |
631 | if (!sbi) | |
632 | return -ENOMEM; | |
633 | sb->s_fs_info = sbi; | |
634 | ||
635 | /* Map only one page for now. Will remap it when fs size is known. */ | |
636 | err = mtd_point(sb->s_mtd, 0, PAGE_SIZE, &sbi->mtd_point_size, | |
637 | &sbi->linear_virt_addr, &sbi->linear_phys_addr); | |
638 | if (err || sbi->mtd_point_size != PAGE_SIZE) { | |
639 | pr_err("unable to get direct memory access to mtd:%s\n", | |
640 | sb->s_mtd->name); | |
641 | return err ? : -ENODATA; | |
642 | } | |
643 | ||
644 | pr_info("checking physical address %pap for linear cramfs image\n", | |
645 | &sbi->linear_phys_addr); | |
74f78fc5 | 646 | err = cramfs_read_super(sb, fc, &super); |
99c18ce5 NP |
647 | if (err) |
648 | return err; | |
649 | ||
650 | /* Remap the whole filesystem now */ | |
651 | pr_info("linear cramfs image on mtd:%s appears to be %lu KB in size\n", | |
652 | sb->s_mtd->name, sbi->size/1024); | |
653 | mtd_unpoint(sb->s_mtd, 0, PAGE_SIZE); | |
654 | err = mtd_point(sb->s_mtd, 0, sbi->size, &sbi->mtd_point_size, | |
655 | &sbi->linear_virt_addr, &sbi->linear_phys_addr); | |
656 | if (err || sbi->mtd_point_size != sbi->size) { | |
657 | pr_err("unable to get direct memory access to mtd:%s\n", | |
658 | sb->s_mtd->name); | |
659 | return err ? : -ENODATA; | |
660 | } | |
661 | ||
662 | return cramfs_finalize_super(sb, &super.root); | |
663 | } | |
664 | ||
726c3342 | 665 | static int cramfs_statfs(struct dentry *dentry, struct kstatfs *buf) |
1da177e4 | 666 | { |
726c3342 | 667 | struct super_block *sb = dentry->d_sb; |
99c18ce5 NP |
668 | u64 id = 0; |
669 | ||
670 | if (sb->s_bdev) | |
671 | id = huge_encode_dev(sb->s_bdev->bd_dev); | |
672 | else if (sb->s_dev) | |
673 | id = huge_encode_dev(sb->s_dev); | |
726c3342 | 674 | |
1da177e4 | 675 | buf->f_type = CRAMFS_MAGIC; |
09cbfeaf | 676 | buf->f_bsize = PAGE_SIZE; |
1da177e4 LT |
677 | buf->f_blocks = CRAMFS_SB(sb)->blocks; |
678 | buf->f_bfree = 0; | |
679 | buf->f_bavail = 0; | |
680 | buf->f_files = CRAMFS_SB(sb)->files; | |
681 | buf->f_ffree = 0; | |
6d1349c7 | 682 | buf->f_fsid = u64_to_fsid(id); |
1da177e4 LT |
683 | buf->f_namelen = CRAMFS_MAXPATHLEN; |
684 | return 0; | |
685 | } | |
686 | ||
687 | /* | |
688 | * Read a cramfs directory entry. | |
689 | */ | |
6f7f231e | 690 | static int cramfs_readdir(struct file *file, struct dir_context *ctx) |
1da177e4 | 691 | { |
6f7f231e | 692 | struct inode *inode = file_inode(file); |
1da177e4 LT |
693 | struct super_block *sb = inode->i_sb; |
694 | char *buf; | |
695 | unsigned int offset; | |
1da177e4 LT |
696 | |
697 | /* Offset within the thing. */ | |
6f7f231e | 698 | if (ctx->pos >= inode->i_size) |
1da177e4 | 699 | return 0; |
6f7f231e | 700 | offset = ctx->pos; |
1da177e4 LT |
701 | /* Directory entries are always 4-byte aligned */ |
702 | if (offset & 3) | |
703 | return -EINVAL; | |
704 | ||
4176ed59 | 705 | buf = kmalloc(CRAMFS_MAXPATHLEN, GFP_KERNEL); |
1da177e4 LT |
706 | if (!buf) |
707 | return -ENOMEM; | |
708 | ||
1da177e4 LT |
709 | while (offset < inode->i_size) { |
710 | struct cramfs_inode *de; | |
711 | unsigned long nextoffset; | |
712 | char *name; | |
713 | ino_t ino; | |
175a4eb7 | 714 | umode_t mode; |
6f7f231e | 715 | int namelen; |
1da177e4 | 716 | |
353ab6e9 | 717 | mutex_lock(&read_mutex); |
4176ed59 | 718 | de = cramfs_read(sb, OFFSET(inode) + offset, sizeof(*de)+CRAMFS_MAXPATHLEN); |
1da177e4 LT |
719 | name = (char *)(de+1); |
720 | ||
721 | /* | |
722 | * Namelengths on disk are shifted by two | |
723 | * and the name padded out to 4-byte boundaries | |
724 | * with zeroes. | |
725 | */ | |
726 | namelen = de->namelen << 2; | |
727 | memcpy(buf, name, namelen); | |
6f772fe6 | 728 | ino = cramino(de, OFFSET(inode) + offset); |
1da177e4 | 729 | mode = de->mode; |
353ab6e9 | 730 | mutex_unlock(&read_mutex); |
1da177e4 LT |
731 | nextoffset = offset + sizeof(*de) + namelen; |
732 | for (;;) { | |
733 | if (!namelen) { | |
734 | kfree(buf); | |
735 | return -EIO; | |
736 | } | |
737 | if (buf[namelen-1]) | |
738 | break; | |
739 | namelen--; | |
740 | } | |
6f7f231e | 741 | if (!dir_emit(ctx, buf, namelen, ino, mode >> 12)) |
1da177e4 LT |
742 | break; |
743 | ||
6f7f231e | 744 | ctx->pos = offset = nextoffset; |
1da177e4 LT |
745 | } |
746 | kfree(buf); | |
747 | return 0; | |
748 | } | |
749 | ||
750 | /* | |
751 | * Lookup and fill in the inode data.. | |
752 | */ | |
31d92e55 | 753 | static struct dentry *cramfs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) |
1da177e4 LT |
754 | { |
755 | unsigned int offset = 0; | |
0577d1ba | 756 | struct inode *inode = NULL; |
1da177e4 LT |
757 | int sorted; |
758 | ||
353ab6e9 | 759 | mutex_lock(&read_mutex); |
1da177e4 LT |
760 | sorted = CRAMFS_SB(dir->i_sb)->flags & CRAMFS_FLAG_SORTED_DIRS; |
761 | while (offset < dir->i_size) { | |
762 | struct cramfs_inode *de; | |
763 | char *name; | |
764 | int namelen, retval; | |
6f772fe6 | 765 | int dir_off = OFFSET(dir) + offset; |
1da177e4 | 766 | |
6f772fe6 | 767 | de = cramfs_read(dir->i_sb, dir_off, sizeof(*de)+CRAMFS_MAXPATHLEN); |
1da177e4 LT |
768 | name = (char *)(de+1); |
769 | ||
770 | /* Try to take advantage of sorted directories */ | |
771 | if (sorted && (dentry->d_name.name[0] < name[0])) | |
772 | break; | |
773 | ||
774 | namelen = de->namelen << 2; | |
775 | offset += sizeof(*de) + namelen; | |
776 | ||
777 | /* Quick check that the name is roughly the right length */ | |
778 | if (((dentry->d_name.len + 3) & ~3) != namelen) | |
779 | continue; | |
780 | ||
781 | for (;;) { | |
782 | if (!namelen) { | |
0577d1ba AV |
783 | inode = ERR_PTR(-EIO); |
784 | goto out; | |
1da177e4 LT |
785 | } |
786 | if (name[namelen-1]) | |
787 | break; | |
788 | namelen--; | |
789 | } | |
790 | if (namelen != dentry->d_name.len) | |
791 | continue; | |
792 | retval = memcmp(dentry->d_name.name, name, namelen); | |
793 | if (retval > 0) | |
794 | continue; | |
795 | if (!retval) { | |
0577d1ba AV |
796 | inode = get_cramfs_inode(dir->i_sb, de, dir_off); |
797 | break; | |
1da177e4 LT |
798 | } |
799 | /* else (retval < 0) */ | |
800 | if (sorted) | |
801 | break; | |
802 | } | |
0577d1ba | 803 | out: |
353ab6e9 | 804 | mutex_unlock(&read_mutex); |
d023b3a1 | 805 | return d_splice_alias(inode, dentry); |
1da177e4 LT |
806 | } |
807 | ||
5aab331a | 808 | static int cramfs_read_folio(struct file *file, struct folio *folio) |
1da177e4 | 809 | { |
5aab331a | 810 | struct page *page = &folio->page; |
1da177e4 | 811 | struct inode *inode = page->mapping->host; |
98310e58 DV |
812 | u32 maxblock; |
813 | int bytes_filled; | |
1da177e4 LT |
814 | void *pgdata; |
815 | ||
09cbfeaf | 816 | maxblock = (inode->i_size + PAGE_SIZE - 1) >> PAGE_SHIFT; |
1da177e4 | 817 | bytes_filled = 0; |
98310e58 DV |
818 | pgdata = kmap(page); |
819 | ||
1da177e4 LT |
820 | if (page->index < maxblock) { |
821 | struct super_block *sb = inode->i_sb; | |
fd4f6f2a NP |
822 | u32 blkptr_offset = OFFSET(inode) + page->index * 4; |
823 | u32 block_ptr, block_start, block_len; | |
824 | bool uncompressed, direct; | |
1da177e4 | 825 | |
353ab6e9 | 826 | mutex_lock(&read_mutex); |
fd4f6f2a NP |
827 | block_ptr = *(u32 *) cramfs_read(sb, blkptr_offset, 4); |
828 | uncompressed = (block_ptr & CRAMFS_BLK_FLAG_UNCOMPRESSED); | |
829 | direct = (block_ptr & CRAMFS_BLK_FLAG_DIRECT_PTR); | |
830 | block_ptr &= ~CRAMFS_BLK_FLAGS; | |
831 | ||
832 | if (direct) { | |
833 | /* | |
834 | * The block pointer is an absolute start pointer, | |
835 | * shifted by 2 bits. The size is included in the | |
836 | * first 2 bytes of the data block when compressed, | |
837 | * or PAGE_SIZE otherwise. | |
838 | */ | |
839 | block_start = block_ptr << CRAMFS_BLK_DIRECT_PTR_SHIFT; | |
840 | if (uncompressed) { | |
841 | block_len = PAGE_SIZE; | |
842 | /* if last block: cap to file length */ | |
843 | if (page->index == maxblock - 1) | |
844 | block_len = | |
845 | offset_in_page(inode->i_size); | |
846 | } else { | |
847 | block_len = *(u16 *) | |
848 | cramfs_read(sb, block_start, 2); | |
849 | block_start += 2; | |
850 | } | |
851 | } else { | |
852 | /* | |
853 | * The block pointer indicates one past the end of | |
854 | * the current block (start of next block). If this | |
855 | * is the first block then it starts where the block | |
856 | * pointer table ends, otherwise its start comes | |
857 | * from the previous block's pointer. | |
858 | */ | |
859 | block_start = OFFSET(inode) + maxblock * 4; | |
860 | if (page->index) | |
861 | block_start = *(u32 *) | |
862 | cramfs_read(sb, blkptr_offset - 4, 4); | |
863 | /* Beware... previous ptr might be a direct ptr */ | |
864 | if (unlikely(block_start & CRAMFS_BLK_FLAG_DIRECT_PTR)) { | |
865 | /* See comments on earlier code. */ | |
866 | u32 prev_start = block_start; | |
56ce68bc NP |
867 | block_start = prev_start & ~CRAMFS_BLK_FLAGS; |
868 | block_start <<= CRAMFS_BLK_DIRECT_PTR_SHIFT; | |
fd4f6f2a NP |
869 | if (prev_start & CRAMFS_BLK_FLAG_UNCOMPRESSED) { |
870 | block_start += PAGE_SIZE; | |
871 | } else { | |
872 | block_len = *(u16 *) | |
873 | cramfs_read(sb, block_start, 2); | |
874 | block_start += 2 + block_len; | |
875 | } | |
876 | } | |
877 | block_start &= ~CRAMFS_BLK_FLAGS; | |
878 | block_len = block_ptr - block_start; | |
879 | } | |
98310e58 | 880 | |
fd4f6f2a | 881 | if (block_len == 0) |
1da177e4 | 882 | ; /* hole */ |
fd4f6f2a NP |
883 | else if (unlikely(block_len > 2*PAGE_SIZE || |
884 | (uncompressed && block_len > PAGE_SIZE))) { | |
885 | mutex_unlock(&read_mutex); | |
886 | pr_err("bad data blocksize %u\n", block_len); | |
98310e58 | 887 | goto err; |
fd4f6f2a NP |
888 | } else if (uncompressed) { |
889 | memcpy(pgdata, | |
890 | cramfs_read(sb, block_start, block_len), | |
891 | block_len); | |
892 | bytes_filled = block_len; | |
98310e58 | 893 | } else { |
1da177e4 | 894 | bytes_filled = cramfs_uncompress_block(pgdata, |
09cbfeaf | 895 | PAGE_SIZE, |
fd4f6f2a NP |
896 | cramfs_read(sb, block_start, block_len), |
897 | block_len); | |
1da177e4 | 898 | } |
fd4f6f2a NP |
899 | mutex_unlock(&read_mutex); |
900 | if (unlikely(bytes_filled < 0)) | |
901 | goto err; | |
98310e58 DV |
902 | } |
903 | ||
09cbfeaf | 904 | memset(pgdata + bytes_filled, 0, PAGE_SIZE - bytes_filled); |
1da177e4 | 905 | flush_dcache_page(page); |
98310e58 | 906 | kunmap(page); |
1da177e4 LT |
907 | SetPageUptodate(page); |
908 | unlock_page(page); | |
909 | return 0; | |
98310e58 DV |
910 | |
911 | err: | |
912 | kunmap(page); | |
913 | ClearPageUptodate(page); | |
914 | SetPageError(page); | |
915 | unlock_page(page); | |
916 | return 0; | |
1da177e4 LT |
917 | } |
918 | ||
f5e54d6e | 919 | static const struct address_space_operations cramfs_aops = { |
5aab331a | 920 | .read_folio = cramfs_read_folio |
1da177e4 LT |
921 | }; |
922 | ||
923 | /* | |
924 | * Our operations: | |
925 | */ | |
926 | ||
927 | /* | |
928 | * A directory can only readdir | |
929 | */ | |
4b6f5d20 | 930 | static const struct file_operations cramfs_directory_operations = { |
1da177e4 LT |
931 | .llseek = generic_file_llseek, |
932 | .read = generic_read_dir, | |
c51da20c | 933 | .iterate_shared = cramfs_readdir, |
1da177e4 LT |
934 | }; |
935 | ||
754661f1 | 936 | static const struct inode_operations cramfs_dir_inode_operations = { |
1da177e4 LT |
937 | .lookup = cramfs_lookup, |
938 | }; | |
939 | ||
ee9b6d61 | 940 | static const struct super_operations cramfs_ops = { |
1da177e4 LT |
941 | .statfs = cramfs_statfs, |
942 | }; | |
943 | ||
74f78fc5 | 944 | static int cramfs_get_tree(struct fs_context *fc) |
1da177e4 | 945 | { |
74f78fc5 | 946 | int ret = -ENOPROTOOPT; |
99c18ce5 NP |
947 | |
948 | if (IS_ENABLED(CONFIG_CRAMFS_MTD)) { | |
74f78fc5 | 949 | ret = get_tree_mtd(fc, cramfs_mtd_fill_super); |
3e5aeec0 MB |
950 | if (!ret) |
951 | return 0; | |
99c18ce5 | 952 | } |
74f78fc5 DH |
953 | if (IS_ENABLED(CONFIG_CRAMFS_BLOCKDEV)) |
954 | ret = get_tree_bdev(fc, cramfs_blkdev_fill_super); | |
99c18ce5 | 955 | return ret; |
1da177e4 LT |
956 | } |
957 | ||
74f78fc5 DH |
958 | static const struct fs_context_operations cramfs_context_ops = { |
959 | .get_tree = cramfs_get_tree, | |
960 | .reconfigure = cramfs_reconfigure, | |
961 | }; | |
962 | ||
963 | /* | |
964 | * Set up the filesystem mount context. | |
965 | */ | |
966 | static int cramfs_init_fs_context(struct fs_context *fc) | |
967 | { | |
968 | fc->ops = &cramfs_context_ops; | |
969 | return 0; | |
970 | } | |
971 | ||
1da177e4 LT |
972 | static struct file_system_type cramfs_fs_type = { |
973 | .owner = THIS_MODULE, | |
974 | .name = "cramfs", | |
74f78fc5 | 975 | .init_fs_context = cramfs_init_fs_context, |
2309fb8e | 976 | .kill_sb = cramfs_kill_sb, |
1da177e4 LT |
977 | .fs_flags = FS_REQUIRES_DEV, |
978 | }; | |
7f78e035 | 979 | MODULE_ALIAS_FS("cramfs"); |
1da177e4 LT |
980 | |
981 | static int __init init_cramfs_fs(void) | |
982 | { | |
50d44ed0 AD |
983 | int rv; |
984 | ||
985 | rv = cramfs_uncompress_init(); | |
986 | if (rv < 0) | |
987 | return rv; | |
988 | rv = register_filesystem(&cramfs_fs_type); | |
989 | if (rv < 0) | |
990 | cramfs_uncompress_exit(); | |
991 | return rv; | |
1da177e4 LT |
992 | } |
993 | ||
994 | static void __exit exit_cramfs_fs(void) | |
995 | { | |
996 | cramfs_uncompress_exit(); | |
997 | unregister_filesystem(&cramfs_fs_type); | |
998 | } | |
999 | ||
1000 | module_init(init_cramfs_fs) | |
1001 | module_exit(exit_cramfs_fs) | |
1002 | MODULE_LICENSE("GPL"); |