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 | 135 | /* Struct copy intentional */ |
86184320 JL |
136 | inode_set_mtime_to_ts(inode, |
137 | inode_set_atime_to_ts(inode, inode_set_ctime_to_ts(inode, zerotime))); | |
77b8a75f AV |
138 | /* inode->i_nlink is left 1 - arguably wrong for directories, |
139 | but it's the best we can do without reading the directory | |
140 | contents. 1 yields the right result in GNU find, even | |
141 | without -noleaf option. */ | |
a97c9bf3 | 142 | |
6f772fe6 SS |
143 | unlock_new_inode(inode); |
144 | ||
1da177e4 LT |
145 | return inode; |
146 | } | |
147 | ||
148 | /* | |
149 | * We have our own block cache: don't fill up the buffer cache | |
150 | * with the rom-image, because the way the filesystem is set | |
151 | * up the accesses should be fairly regular and cached in the | |
152 | * page cache and dentry tree anyway.. | |
153 | * | |
154 | * This also acts as a way to guarantee contiguous areas of up to | |
ea1754a0 | 155 | * BLKS_PER_BUF*PAGE_SIZE, so that the caller doesn't need to |
1da177e4 LT |
156 | * worry about end-of-buffer issues even when decompressing a full |
157 | * page cache. | |
99c18ce5 NP |
158 | * |
159 | * Note: This is all optimized away at compile time when | |
160 | * CONFIG_CRAMFS_BLOCKDEV=n. | |
1da177e4 LT |
161 | */ |
162 | #define READ_BUFFERS (2) | |
163 | /* NEXT_BUFFER(): Loop over [0..(READ_BUFFERS-1)]. */ | |
164 | #define NEXT_BUFFER(_ix) ((_ix) ^ 1) | |
165 | ||
166 | /* | |
167 | * BLKS_PER_BUF_SHIFT should be at least 2 to allow for "compressed" | |
168 | * data that takes up more space than the original and with unlucky | |
169 | * alignment. | |
170 | */ | |
171 | #define BLKS_PER_BUF_SHIFT (2) | |
172 | #define BLKS_PER_BUF (1 << BLKS_PER_BUF_SHIFT) | |
09cbfeaf | 173 | #define BUFFER_SIZE (BLKS_PER_BUF*PAGE_SIZE) |
1da177e4 LT |
174 | |
175 | static unsigned char read_buffers[READ_BUFFERS][BUFFER_SIZE]; | |
176 | static unsigned buffer_blocknr[READ_BUFFERS]; | |
31d92e55 | 177 | static struct super_block *buffer_dev[READ_BUFFERS]; |
1da177e4 LT |
178 | static int next_buffer; |
179 | ||
180 | /* | |
99c18ce5 | 181 | * Populate our block cache and return a pointer to it. |
1da177e4 | 182 | */ |
99c18ce5 NP |
183 | static void *cramfs_blkdev_read(struct super_block *sb, unsigned int offset, |
184 | unsigned int len) | |
1da177e4 LT |
185 | { |
186 | struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping; | |
3e351026 | 187 | struct file_ra_state ra = {}; |
1da177e4 | 188 | struct page *pages[BLKS_PER_BUF]; |
6bbfb077 | 189 | unsigned i, blocknr, buffer; |
1da177e4 LT |
190 | unsigned long devsize; |
191 | char *data; | |
192 | ||
193 | if (!len) | |
194 | return NULL; | |
09cbfeaf KS |
195 | blocknr = offset >> PAGE_SHIFT; |
196 | offset &= PAGE_SIZE - 1; | |
1da177e4 LT |
197 | |
198 | /* Check if an existing buffer already has the data.. */ | |
199 | for (i = 0; i < READ_BUFFERS; i++) { | |
200 | unsigned int blk_offset; | |
201 | ||
202 | if (buffer_dev[i] != sb) | |
203 | continue; | |
204 | if (blocknr < buffer_blocknr[i]) | |
205 | continue; | |
09cbfeaf | 206 | blk_offset = (blocknr - buffer_blocknr[i]) << PAGE_SHIFT; |
1da177e4 | 207 | blk_offset += offset; |
672ca9dd NP |
208 | if (blk_offset > BUFFER_SIZE || |
209 | blk_offset + len > BUFFER_SIZE) | |
1da177e4 LT |
210 | continue; |
211 | return read_buffers[i] + blk_offset; | |
212 | } | |
213 | ||
5816e91e | 214 | devsize = bdev_nr_bytes(sb->s_bdev) >> PAGE_SHIFT; |
1da177e4 LT |
215 | |
216 | /* Ok, read in BLKS_PER_BUF pages completely first. */ | |
cf948cbc MWO |
217 | file_ra_state_init(&ra, mapping); |
218 | page_cache_sync_readahead(mapping, &ra, NULL, blocknr, BLKS_PER_BUF); | |
219 | ||
1da177e4 LT |
220 | for (i = 0; i < BLKS_PER_BUF; i++) { |
221 | struct page *page = NULL; | |
222 | ||
223 | if (blocknr + i < devsize) { | |
67f9fd91 | 224 | page = read_mapping_page(mapping, blocknr + i, NULL); |
1da177e4 LT |
225 | /* synchronous error? */ |
226 | if (IS_ERR(page)) | |
227 | page = NULL; | |
228 | } | |
229 | pages[i] = page; | |
230 | } | |
231 | ||
1da177e4 LT |
232 | buffer = next_buffer; |
233 | next_buffer = NEXT_BUFFER(buffer); | |
234 | buffer_blocknr[buffer] = blocknr; | |
235 | buffer_dev[buffer] = sb; | |
236 | ||
237 | data = read_buffers[buffer]; | |
238 | for (i = 0; i < BLKS_PER_BUF; i++) { | |
239 | struct page *page = pages[i]; | |
31d92e55 | 240 | |
1da177e4 | 241 | if (page) { |
f27c942e | 242 | memcpy_from_page(data, page, 0, PAGE_SIZE); |
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; | |
1c71222e | 411 | vm_flags_set(vma, VM_MIXEDMAP); |
eddcd976 | 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 | { | |
fc4f4be9 | 440 | return is_nommu_shared_mapping(vma->vm_flags) ? 0 : -ENOSYS; |
eddcd976 NP |
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, | |
2cb1e089 | 477 | .splice_read = filemap_splice_read, |
eddcd976 NP |
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 | |
aca740ce JK |
489 | generic_shutdown_super(sb); |
490 | ||
08a8f308 | 491 | if (IS_ENABLED(CONFIG_CRAMFS_MTD) && sb->s_mtd) { |
99c18ce5 NP |
492 | if (sbi && sbi->mtd_point_size) |
493 | mtd_unpoint(sb->s_mtd, 0, sbi->mtd_point_size); | |
aca740ce JK |
494 | put_mtd_device(sb->s_mtd); |
495 | sb->s_mtd = NULL; | |
99c18ce5 | 496 | } else if (IS_ENABLED(CONFIG_CRAMFS_BLOCKDEV) && sb->s_bdev) { |
aca740ce | 497 | sync_blockdev(sb->s_bdev); |
2ea6f689 | 498 | blkdev_put(sb->s_bdev, sb); |
99c18ce5 | 499 | } |
2309fb8e | 500 | kfree(sbi); |
1da177e4 LT |
501 | } |
502 | ||
74f78fc5 | 503 | static int cramfs_reconfigure(struct fs_context *fc) |
1da177e4 | 504 | { |
74f78fc5 DH |
505 | sync_filesystem(fc->root->d_sb); |
506 | fc->sb_flags |= SB_RDONLY; | |
1da177e4 LT |
507 | return 0; |
508 | } | |
509 | ||
74f78fc5 DH |
510 | static int cramfs_read_super(struct super_block *sb, struct fs_context *fc, |
511 | struct cramfs_super *super) | |
1da177e4 | 512 | { |
99c18ce5 | 513 | struct cramfs_sb_info *sbi = CRAMFS_SB(sb); |
1da177e4 | 514 | unsigned long root_offset; |
74f78fc5 | 515 | bool silent = fc->sb_flags & SB_SILENT; |
1da177e4 | 516 | |
99c18ce5 NP |
517 | /* We don't know the real size yet */ |
518 | sbi->size = PAGE_SIZE; | |
1da177e4 LT |
519 | |
520 | /* Read the first block and get the superblock from it */ | |
99c18ce5 NP |
521 | mutex_lock(&read_mutex); |
522 | memcpy(super, cramfs_read(sb, 0, sizeof(*super)), sizeof(*super)); | |
353ab6e9 | 523 | mutex_unlock(&read_mutex); |
1da177e4 LT |
524 | |
525 | /* Do sanity checks on the superblock */ | |
99c18ce5 | 526 | if (super->magic != CRAMFS_MAGIC) { |
0cc785ec | 527 | /* check for wrong endianness */ |
99c18ce5 | 528 | if (super->magic == CRAMFS_MAGIC_WEND) { |
ac8d35c5 | 529 | if (!silent) |
e1ee7d85 | 530 | errorfc(fc, "wrong endianness"); |
2309fb8e | 531 | return -EINVAL; |
ac8d35c5 AD |
532 | } |
533 | ||
1da177e4 | 534 | /* check at 512 byte offset */ |
353ab6e9 | 535 | mutex_lock(&read_mutex); |
99c18ce5 NP |
536 | memcpy(super, |
537 | cramfs_read(sb, 512, sizeof(*super)), | |
538 | sizeof(*super)); | |
353ab6e9 | 539 | mutex_unlock(&read_mutex); |
99c18ce5 NP |
540 | if (super->magic != CRAMFS_MAGIC) { |
541 | if (super->magic == CRAMFS_MAGIC_WEND && !silent) | |
e1ee7d85 | 542 | errorfc(fc, "wrong endianness"); |
ac8d35c5 | 543 | else if (!silent) |
e1ee7d85 | 544 | errorfc(fc, "wrong magic"); |
2309fb8e | 545 | return -EINVAL; |
1da177e4 LT |
546 | } |
547 | } | |
548 | ||
549 | /* get feature flags first */ | |
99c18ce5 | 550 | if (super->flags & ~CRAMFS_SUPPORTED_FLAGS) { |
e1ee7d85 | 551 | errorfc(fc, "unsupported filesystem features"); |
2309fb8e | 552 | return -EINVAL; |
1da177e4 LT |
553 | } |
554 | ||
555 | /* Check that the root inode is in a sane state */ | |
99c18ce5 | 556 | if (!S_ISDIR(super->root.mode)) { |
e1ee7d85 | 557 | errorfc(fc, "root is not a directory"); |
2309fb8e | 558 | return -EINVAL; |
1da177e4 | 559 | } |
6f772fe6 | 560 | /* correct strange, hard-coded permissions of mkcramfs */ |
99c18ce5 | 561 | super->root.mode |= 0555; |
6f772fe6 | 562 | |
99c18ce5 NP |
563 | root_offset = super->root.offset << 2; |
564 | if (super->flags & CRAMFS_FLAG_FSID_VERSION_2) { | |
565 | sbi->size = super->size; | |
566 | sbi->blocks = super->fsid.blocks; | |
567 | sbi->files = super->fsid.files; | |
1da177e4 | 568 | } else { |
31d92e55 FF |
569 | sbi->size = 1<<28; |
570 | sbi->blocks = 0; | |
571 | sbi->files = 0; | |
1da177e4 | 572 | } |
99c18ce5 NP |
573 | sbi->magic = super->magic; |
574 | sbi->flags = super->flags; | |
1da177e4 | 575 | if (root_offset == 0) |
e1ee7d85 | 576 | infofc(fc, "empty filesystem"); |
99c18ce5 | 577 | else if (!(super->flags & CRAMFS_FLAG_SHIFTED_ROOT_OFFSET) && |
1da177e4 LT |
578 | ((root_offset != sizeof(struct cramfs_super)) && |
579 | (root_offset != 512 + sizeof(struct cramfs_super)))) | |
580 | { | |
e1ee7d85 | 581 | errorfc(fc, "bad root offset %lu", root_offset); |
2309fb8e | 582 | return -EINVAL; |
1da177e4 LT |
583 | } |
584 | ||
99c18ce5 NP |
585 | return 0; |
586 | } | |
587 | ||
588 | static int cramfs_finalize_super(struct super_block *sb, | |
589 | struct cramfs_inode *cramfs_root) | |
590 | { | |
591 | struct inode *root; | |
592 | ||
1da177e4 | 593 | /* Set it all up.. */ |
1751e8a6 | 594 | sb->s_flags |= SB_RDONLY; |
22b13969 DD |
595 | sb->s_time_min = 0; |
596 | sb->s_time_max = 0; | |
1da177e4 | 597 | sb->s_op = &cramfs_ops; |
99c18ce5 | 598 | root = get_cramfs_inode(sb, cramfs_root, 0); |
0577d1ba | 599 | if (IS_ERR(root)) |
2309fb8e | 600 | return PTR_ERR(root); |
48fde701 AV |
601 | sb->s_root = d_make_root(root); |
602 | if (!sb->s_root) | |
2309fb8e | 603 | return -ENOMEM; |
1da177e4 | 604 | return 0; |
1da177e4 LT |
605 | } |
606 | ||
74f78fc5 | 607 | static int cramfs_blkdev_fill_super(struct super_block *sb, struct fs_context *fc) |
99c18ce5 NP |
608 | { |
609 | struct cramfs_sb_info *sbi; | |
610 | struct cramfs_super super; | |
611 | int i, err; | |
612 | ||
613 | sbi = kzalloc(sizeof(struct cramfs_sb_info), GFP_KERNEL); | |
614 | if (!sbi) | |
615 | return -ENOMEM; | |
616 | sb->s_fs_info = sbi; | |
617 | ||
618 | /* Invalidate the read buffers on mount: think disk change.. */ | |
619 | for (i = 0; i < READ_BUFFERS; i++) | |
620 | buffer_blocknr[i] = -1; | |
621 | ||
74f78fc5 | 622 | err = cramfs_read_super(sb, fc, &super); |
99c18ce5 NP |
623 | if (err) |
624 | return err; | |
625 | return cramfs_finalize_super(sb, &super.root); | |
626 | } | |
627 | ||
74f78fc5 | 628 | static int cramfs_mtd_fill_super(struct super_block *sb, struct fs_context *fc) |
99c18ce5 NP |
629 | { |
630 | struct cramfs_sb_info *sbi; | |
631 | struct cramfs_super super; | |
632 | int err; | |
633 | ||
634 | sbi = kzalloc(sizeof(struct cramfs_sb_info), GFP_KERNEL); | |
635 | if (!sbi) | |
636 | return -ENOMEM; | |
637 | sb->s_fs_info = sbi; | |
638 | ||
639 | /* Map only one page for now. Will remap it when fs size is known. */ | |
640 | err = mtd_point(sb->s_mtd, 0, PAGE_SIZE, &sbi->mtd_point_size, | |
641 | &sbi->linear_virt_addr, &sbi->linear_phys_addr); | |
642 | if (err || sbi->mtd_point_size != PAGE_SIZE) { | |
643 | pr_err("unable to get direct memory access to mtd:%s\n", | |
644 | sb->s_mtd->name); | |
645 | return err ? : -ENODATA; | |
646 | } | |
647 | ||
648 | pr_info("checking physical address %pap for linear cramfs image\n", | |
649 | &sbi->linear_phys_addr); | |
74f78fc5 | 650 | err = cramfs_read_super(sb, fc, &super); |
99c18ce5 NP |
651 | if (err) |
652 | return err; | |
653 | ||
654 | /* Remap the whole filesystem now */ | |
655 | pr_info("linear cramfs image on mtd:%s appears to be %lu KB in size\n", | |
656 | sb->s_mtd->name, sbi->size/1024); | |
657 | mtd_unpoint(sb->s_mtd, 0, PAGE_SIZE); | |
658 | err = mtd_point(sb->s_mtd, 0, sbi->size, &sbi->mtd_point_size, | |
659 | &sbi->linear_virt_addr, &sbi->linear_phys_addr); | |
660 | if (err || sbi->mtd_point_size != sbi->size) { | |
661 | pr_err("unable to get direct memory access to mtd:%s\n", | |
662 | sb->s_mtd->name); | |
663 | return err ? : -ENODATA; | |
664 | } | |
665 | ||
666 | return cramfs_finalize_super(sb, &super.root); | |
667 | } | |
668 | ||
726c3342 | 669 | static int cramfs_statfs(struct dentry *dentry, struct kstatfs *buf) |
1da177e4 | 670 | { |
726c3342 | 671 | struct super_block *sb = dentry->d_sb; |
99c18ce5 NP |
672 | u64 id = 0; |
673 | ||
674 | if (sb->s_bdev) | |
675 | id = huge_encode_dev(sb->s_bdev->bd_dev); | |
676 | else if (sb->s_dev) | |
677 | id = huge_encode_dev(sb->s_dev); | |
726c3342 | 678 | |
1da177e4 | 679 | buf->f_type = CRAMFS_MAGIC; |
09cbfeaf | 680 | buf->f_bsize = PAGE_SIZE; |
1da177e4 LT |
681 | buf->f_blocks = CRAMFS_SB(sb)->blocks; |
682 | buf->f_bfree = 0; | |
683 | buf->f_bavail = 0; | |
684 | buf->f_files = CRAMFS_SB(sb)->files; | |
685 | buf->f_ffree = 0; | |
6d1349c7 | 686 | buf->f_fsid = u64_to_fsid(id); |
1da177e4 LT |
687 | buf->f_namelen = CRAMFS_MAXPATHLEN; |
688 | return 0; | |
689 | } | |
690 | ||
691 | /* | |
692 | * Read a cramfs directory entry. | |
693 | */ | |
6f7f231e | 694 | static int cramfs_readdir(struct file *file, struct dir_context *ctx) |
1da177e4 | 695 | { |
6f7f231e | 696 | struct inode *inode = file_inode(file); |
1da177e4 LT |
697 | struct super_block *sb = inode->i_sb; |
698 | char *buf; | |
699 | unsigned int offset; | |
1da177e4 LT |
700 | |
701 | /* Offset within the thing. */ | |
6f7f231e | 702 | if (ctx->pos >= inode->i_size) |
1da177e4 | 703 | return 0; |
6f7f231e | 704 | offset = ctx->pos; |
1da177e4 LT |
705 | /* Directory entries are always 4-byte aligned */ |
706 | if (offset & 3) | |
707 | return -EINVAL; | |
708 | ||
4176ed59 | 709 | buf = kmalloc(CRAMFS_MAXPATHLEN, GFP_KERNEL); |
1da177e4 LT |
710 | if (!buf) |
711 | return -ENOMEM; | |
712 | ||
1da177e4 LT |
713 | while (offset < inode->i_size) { |
714 | struct cramfs_inode *de; | |
715 | unsigned long nextoffset; | |
716 | char *name; | |
717 | ino_t ino; | |
175a4eb7 | 718 | umode_t mode; |
6f7f231e | 719 | int namelen; |
1da177e4 | 720 | |
353ab6e9 | 721 | mutex_lock(&read_mutex); |
4176ed59 | 722 | de = cramfs_read(sb, OFFSET(inode) + offset, sizeof(*de)+CRAMFS_MAXPATHLEN); |
1da177e4 LT |
723 | name = (char *)(de+1); |
724 | ||
725 | /* | |
726 | * Namelengths on disk are shifted by two | |
727 | * and the name padded out to 4-byte boundaries | |
728 | * with zeroes. | |
729 | */ | |
730 | namelen = de->namelen << 2; | |
731 | memcpy(buf, name, namelen); | |
6f772fe6 | 732 | ino = cramino(de, OFFSET(inode) + offset); |
1da177e4 | 733 | mode = de->mode; |
353ab6e9 | 734 | mutex_unlock(&read_mutex); |
1da177e4 LT |
735 | nextoffset = offset + sizeof(*de) + namelen; |
736 | for (;;) { | |
737 | if (!namelen) { | |
738 | kfree(buf); | |
739 | return -EIO; | |
740 | } | |
741 | if (buf[namelen-1]) | |
742 | break; | |
743 | namelen--; | |
744 | } | |
6f7f231e | 745 | if (!dir_emit(ctx, buf, namelen, ino, mode >> 12)) |
1da177e4 LT |
746 | break; |
747 | ||
6f7f231e | 748 | ctx->pos = offset = nextoffset; |
1da177e4 LT |
749 | } |
750 | kfree(buf); | |
751 | return 0; | |
752 | } | |
753 | ||
754 | /* | |
755 | * Lookup and fill in the inode data.. | |
756 | */ | |
31d92e55 | 757 | static struct dentry *cramfs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) |
1da177e4 LT |
758 | { |
759 | unsigned int offset = 0; | |
0577d1ba | 760 | struct inode *inode = NULL; |
1da177e4 LT |
761 | int sorted; |
762 | ||
353ab6e9 | 763 | mutex_lock(&read_mutex); |
1da177e4 LT |
764 | sorted = CRAMFS_SB(dir->i_sb)->flags & CRAMFS_FLAG_SORTED_DIRS; |
765 | while (offset < dir->i_size) { | |
766 | struct cramfs_inode *de; | |
767 | char *name; | |
768 | int namelen, retval; | |
6f772fe6 | 769 | int dir_off = OFFSET(dir) + offset; |
1da177e4 | 770 | |
6f772fe6 | 771 | de = cramfs_read(dir->i_sb, dir_off, sizeof(*de)+CRAMFS_MAXPATHLEN); |
1da177e4 LT |
772 | name = (char *)(de+1); |
773 | ||
774 | /* Try to take advantage of sorted directories */ | |
775 | if (sorted && (dentry->d_name.name[0] < name[0])) | |
776 | break; | |
777 | ||
778 | namelen = de->namelen << 2; | |
779 | offset += sizeof(*de) + namelen; | |
780 | ||
781 | /* Quick check that the name is roughly the right length */ | |
782 | if (((dentry->d_name.len + 3) & ~3) != namelen) | |
783 | continue; | |
784 | ||
785 | for (;;) { | |
786 | if (!namelen) { | |
0577d1ba AV |
787 | inode = ERR_PTR(-EIO); |
788 | goto out; | |
1da177e4 LT |
789 | } |
790 | if (name[namelen-1]) | |
791 | break; | |
792 | namelen--; | |
793 | } | |
794 | if (namelen != dentry->d_name.len) | |
795 | continue; | |
796 | retval = memcmp(dentry->d_name.name, name, namelen); | |
797 | if (retval > 0) | |
798 | continue; | |
799 | if (!retval) { | |
0577d1ba AV |
800 | inode = get_cramfs_inode(dir->i_sb, de, dir_off); |
801 | break; | |
1da177e4 LT |
802 | } |
803 | /* else (retval < 0) */ | |
804 | if (sorted) | |
805 | break; | |
806 | } | |
0577d1ba | 807 | out: |
353ab6e9 | 808 | mutex_unlock(&read_mutex); |
d023b3a1 | 809 | return d_splice_alias(inode, dentry); |
1da177e4 LT |
810 | } |
811 | ||
5aab331a | 812 | static int cramfs_read_folio(struct file *file, struct folio *folio) |
1da177e4 | 813 | { |
5aab331a | 814 | struct page *page = &folio->page; |
1da177e4 | 815 | struct inode *inode = page->mapping->host; |
98310e58 DV |
816 | u32 maxblock; |
817 | int bytes_filled; | |
1da177e4 LT |
818 | void *pgdata; |
819 | ||
09cbfeaf | 820 | maxblock = (inode->i_size + PAGE_SIZE - 1) >> PAGE_SHIFT; |
1da177e4 | 821 | bytes_filled = 0; |
f27c942e | 822 | pgdata = kmap_local_page(page); |
98310e58 | 823 | |
1da177e4 LT |
824 | if (page->index < maxblock) { |
825 | struct super_block *sb = inode->i_sb; | |
fd4f6f2a NP |
826 | u32 blkptr_offset = OFFSET(inode) + page->index * 4; |
827 | u32 block_ptr, block_start, block_len; | |
828 | bool uncompressed, direct; | |
1da177e4 | 829 | |
353ab6e9 | 830 | mutex_lock(&read_mutex); |
fd4f6f2a NP |
831 | block_ptr = *(u32 *) cramfs_read(sb, blkptr_offset, 4); |
832 | uncompressed = (block_ptr & CRAMFS_BLK_FLAG_UNCOMPRESSED); | |
833 | direct = (block_ptr & CRAMFS_BLK_FLAG_DIRECT_PTR); | |
834 | block_ptr &= ~CRAMFS_BLK_FLAGS; | |
835 | ||
836 | if (direct) { | |
837 | /* | |
838 | * The block pointer is an absolute start pointer, | |
839 | * shifted by 2 bits. The size is included in the | |
840 | * first 2 bytes of the data block when compressed, | |
841 | * or PAGE_SIZE otherwise. | |
842 | */ | |
843 | block_start = block_ptr << CRAMFS_BLK_DIRECT_PTR_SHIFT; | |
844 | if (uncompressed) { | |
845 | block_len = PAGE_SIZE; | |
846 | /* if last block: cap to file length */ | |
847 | if (page->index == maxblock - 1) | |
848 | block_len = | |
849 | offset_in_page(inode->i_size); | |
850 | } else { | |
851 | block_len = *(u16 *) | |
852 | cramfs_read(sb, block_start, 2); | |
853 | block_start += 2; | |
854 | } | |
855 | } else { | |
856 | /* | |
857 | * The block pointer indicates one past the end of | |
858 | * the current block (start of next block). If this | |
859 | * is the first block then it starts where the block | |
860 | * pointer table ends, otherwise its start comes | |
861 | * from the previous block's pointer. | |
862 | */ | |
863 | block_start = OFFSET(inode) + maxblock * 4; | |
864 | if (page->index) | |
865 | block_start = *(u32 *) | |
866 | cramfs_read(sb, blkptr_offset - 4, 4); | |
867 | /* Beware... previous ptr might be a direct ptr */ | |
868 | if (unlikely(block_start & CRAMFS_BLK_FLAG_DIRECT_PTR)) { | |
869 | /* See comments on earlier code. */ | |
870 | u32 prev_start = block_start; | |
56ce68bc NP |
871 | block_start = prev_start & ~CRAMFS_BLK_FLAGS; |
872 | block_start <<= CRAMFS_BLK_DIRECT_PTR_SHIFT; | |
fd4f6f2a NP |
873 | if (prev_start & CRAMFS_BLK_FLAG_UNCOMPRESSED) { |
874 | block_start += PAGE_SIZE; | |
875 | } else { | |
876 | block_len = *(u16 *) | |
877 | cramfs_read(sb, block_start, 2); | |
878 | block_start += 2 + block_len; | |
879 | } | |
880 | } | |
881 | block_start &= ~CRAMFS_BLK_FLAGS; | |
882 | block_len = block_ptr - block_start; | |
883 | } | |
98310e58 | 884 | |
fd4f6f2a | 885 | if (block_len == 0) |
1da177e4 | 886 | ; /* hole */ |
fd4f6f2a NP |
887 | else if (unlikely(block_len > 2*PAGE_SIZE || |
888 | (uncompressed && block_len > PAGE_SIZE))) { | |
889 | mutex_unlock(&read_mutex); | |
890 | pr_err("bad data blocksize %u\n", block_len); | |
98310e58 | 891 | goto err; |
fd4f6f2a NP |
892 | } else if (uncompressed) { |
893 | memcpy(pgdata, | |
894 | cramfs_read(sb, block_start, block_len), | |
895 | block_len); | |
896 | bytes_filled = block_len; | |
98310e58 | 897 | } else { |
1da177e4 | 898 | bytes_filled = cramfs_uncompress_block(pgdata, |
09cbfeaf | 899 | PAGE_SIZE, |
fd4f6f2a NP |
900 | cramfs_read(sb, block_start, block_len), |
901 | block_len); | |
1da177e4 | 902 | } |
fd4f6f2a NP |
903 | mutex_unlock(&read_mutex); |
904 | if (unlikely(bytes_filled < 0)) | |
905 | goto err; | |
98310e58 DV |
906 | } |
907 | ||
09cbfeaf | 908 | memset(pgdata + bytes_filled, 0, PAGE_SIZE - bytes_filled); |
1da177e4 | 909 | flush_dcache_page(page); |
f27c942e | 910 | kunmap_local(pgdata); |
1da177e4 LT |
911 | SetPageUptodate(page); |
912 | unlock_page(page); | |
913 | return 0; | |
98310e58 DV |
914 | |
915 | err: | |
f27c942e | 916 | kunmap_local(pgdata); |
98310e58 DV |
917 | ClearPageUptodate(page); |
918 | SetPageError(page); | |
919 | unlock_page(page); | |
920 | return 0; | |
1da177e4 LT |
921 | } |
922 | ||
f5e54d6e | 923 | static const struct address_space_operations cramfs_aops = { |
5aab331a | 924 | .read_folio = cramfs_read_folio |
1da177e4 LT |
925 | }; |
926 | ||
927 | /* | |
928 | * Our operations: | |
929 | */ | |
930 | ||
931 | /* | |
932 | * A directory can only readdir | |
933 | */ | |
4b6f5d20 | 934 | static const struct file_operations cramfs_directory_operations = { |
1da177e4 LT |
935 | .llseek = generic_file_llseek, |
936 | .read = generic_read_dir, | |
c51da20c | 937 | .iterate_shared = cramfs_readdir, |
1da177e4 LT |
938 | }; |
939 | ||
754661f1 | 940 | static const struct inode_operations cramfs_dir_inode_operations = { |
1da177e4 LT |
941 | .lookup = cramfs_lookup, |
942 | }; | |
943 | ||
ee9b6d61 | 944 | static const struct super_operations cramfs_ops = { |
1da177e4 LT |
945 | .statfs = cramfs_statfs, |
946 | }; | |
947 | ||
74f78fc5 | 948 | static int cramfs_get_tree(struct fs_context *fc) |
1da177e4 | 949 | { |
74f78fc5 | 950 | int ret = -ENOPROTOOPT; |
99c18ce5 NP |
951 | |
952 | if (IS_ENABLED(CONFIG_CRAMFS_MTD)) { | |
74f78fc5 | 953 | ret = get_tree_mtd(fc, cramfs_mtd_fill_super); |
3e5aeec0 MB |
954 | if (!ret) |
955 | return 0; | |
99c18ce5 | 956 | } |
74f78fc5 DH |
957 | if (IS_ENABLED(CONFIG_CRAMFS_BLOCKDEV)) |
958 | ret = get_tree_bdev(fc, cramfs_blkdev_fill_super); | |
99c18ce5 | 959 | return ret; |
1da177e4 LT |
960 | } |
961 | ||
74f78fc5 DH |
962 | static const struct fs_context_operations cramfs_context_ops = { |
963 | .get_tree = cramfs_get_tree, | |
964 | .reconfigure = cramfs_reconfigure, | |
965 | }; | |
966 | ||
967 | /* | |
968 | * Set up the filesystem mount context. | |
969 | */ | |
970 | static int cramfs_init_fs_context(struct fs_context *fc) | |
971 | { | |
972 | fc->ops = &cramfs_context_ops; | |
973 | return 0; | |
974 | } | |
975 | ||
1da177e4 LT |
976 | static struct file_system_type cramfs_fs_type = { |
977 | .owner = THIS_MODULE, | |
978 | .name = "cramfs", | |
74f78fc5 | 979 | .init_fs_context = cramfs_init_fs_context, |
2309fb8e | 980 | .kill_sb = cramfs_kill_sb, |
1da177e4 LT |
981 | .fs_flags = FS_REQUIRES_DEV, |
982 | }; | |
7f78e035 | 983 | MODULE_ALIAS_FS("cramfs"); |
1da177e4 LT |
984 | |
985 | static int __init init_cramfs_fs(void) | |
986 | { | |
50d44ed0 AD |
987 | int rv; |
988 | ||
989 | rv = cramfs_uncompress_init(); | |
990 | if (rv < 0) | |
991 | return rv; | |
992 | rv = register_filesystem(&cramfs_fs_type); | |
993 | if (rv < 0) | |
994 | cramfs_uncompress_exit(); | |
995 | return rv; | |
1da177e4 LT |
996 | } |
997 | ||
998 | static void __exit exit_cramfs_fs(void) | |
999 | { | |
1000 | cramfs_uncompress_exit(); | |
1001 | unregister_filesystem(&cramfs_fs_type); | |
1002 | } | |
1003 | ||
1004 | module_init(init_cramfs_fs) | |
1005 | module_exit(exit_cramfs_fs) | |
1006 | MODULE_LICENSE("GPL"); |