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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/fs/fat/inode.c | |
3 | * | |
4 | * Written 1992,1993 by Werner Almesberger | |
5 | * VFAT extensions by Gordon Chaffee, merged with msdos fs by Henrik Storner | |
6 | * Rewritten for the constant inumbers support by Al Viro | |
7 | * | |
8 | * Fixes: | |
9 | * | |
10 | * Max Cohan: Fixed invalid FSINFO offset when info_sector is 0 | |
11 | */ | |
12 | ||
13 | #include <linux/module.h> | |
14 | #include <linux/init.h> | |
15 | #include <linux/time.h> | |
16 | #include <linux/slab.h> | |
17 | #include <linux/smp_lock.h> | |
18 | #include <linux/seq_file.h> | |
19 | #include <linux/msdos_fs.h> | |
20 | #include <linux/pagemap.h> | |
21 | #include <linux/buffer_head.h> | |
22 | #include <linux/mount.h> | |
23 | #include <linux/vfs.h> | |
24 | #include <linux/parser.h> | |
25 | #include <asm/unaligned.h> | |
26 | ||
27 | #ifndef CONFIG_FAT_DEFAULT_IOCHARSET | |
28 | /* if user don't select VFAT, this is undefined. */ | |
29 | #define CONFIG_FAT_DEFAULT_IOCHARSET "" | |
30 | #endif | |
31 | ||
32 | static int fat_default_codepage = CONFIG_FAT_DEFAULT_CODEPAGE; | |
33 | static char fat_default_iocharset[] = CONFIG_FAT_DEFAULT_IOCHARSET; | |
34 | ||
35 | ||
36 | static int fat_add_cluster(struct inode *inode) | |
37 | { | |
38 | int err, cluster; | |
39 | ||
40 | err = fat_alloc_clusters(inode, &cluster, 1); | |
41 | if (err) | |
42 | return err; | |
43 | /* FIXME: this cluster should be added after data of this | |
44 | * cluster is writed */ | |
45 | err = fat_chain_add(inode, cluster, 1); | |
46 | if (err) | |
47 | fat_free_clusters(inode, cluster); | |
48 | return err; | |
49 | } | |
50 | ||
51 | static int fat_get_block(struct inode *inode, sector_t iblock, | |
52 | struct buffer_head *bh_result, int create) | |
53 | { | |
54 | struct super_block *sb = inode->i_sb; | |
55 | sector_t phys; | |
56 | int err; | |
57 | ||
58 | err = fat_bmap(inode, iblock, &phys); | |
59 | if (err) | |
60 | return err; | |
61 | if (phys) { | |
62 | map_bh(bh_result, sb, phys); | |
63 | return 0; | |
64 | } | |
65 | if (!create) | |
66 | return 0; | |
67 | if (iblock != MSDOS_I(inode)->mmu_private >> sb->s_blocksize_bits) { | |
68 | fat_fs_panic(sb, "corrupted file size (i_pos %lld, %lld)", | |
69 | MSDOS_I(inode)->i_pos, MSDOS_I(inode)->mmu_private); | |
70 | return -EIO; | |
71 | } | |
72 | if (!((unsigned long)iblock & (MSDOS_SB(sb)->sec_per_clus - 1))) { | |
73 | err = fat_add_cluster(inode); | |
74 | if (err) | |
75 | return err; | |
76 | } | |
77 | MSDOS_I(inode)->mmu_private += sb->s_blocksize; | |
78 | err = fat_bmap(inode, iblock, &phys); | |
79 | if (err) | |
80 | return err; | |
81 | if (!phys) | |
82 | BUG(); | |
83 | set_buffer_new(bh_result); | |
84 | map_bh(bh_result, sb, phys); | |
85 | return 0; | |
86 | } | |
87 | ||
88 | static int fat_writepage(struct page *page, struct writeback_control *wbc) | |
89 | { | |
90 | return block_write_full_page(page, fat_get_block, wbc); | |
91 | } | |
92 | ||
93 | static int fat_readpage(struct file *file, struct page *page) | |
94 | { | |
95 | return block_read_full_page(page, fat_get_block); | |
96 | } | |
97 | ||
98 | static int fat_prepare_write(struct file *file, struct page *page, | |
99 | unsigned from, unsigned to) | |
100 | { | |
101 | return cont_prepare_write(page, from, to, fat_get_block, | |
102 | &MSDOS_I(page->mapping->host)->mmu_private); | |
103 | } | |
104 | ||
105 | static sector_t _fat_bmap(struct address_space *mapping, sector_t block) | |
106 | { | |
107 | return generic_block_bmap(mapping, block, fat_get_block); | |
108 | } | |
109 | ||
110 | static struct address_space_operations fat_aops = { | |
111 | .readpage = fat_readpage, | |
112 | .writepage = fat_writepage, | |
113 | .sync_page = block_sync_page, | |
114 | .prepare_write = fat_prepare_write, | |
115 | .commit_write = generic_commit_write, | |
116 | .bmap = _fat_bmap | |
117 | }; | |
118 | ||
119 | /* | |
120 | * New FAT inode stuff. We do the following: | |
121 | * a) i_ino is constant and has nothing with on-disk location. | |
122 | * b) FAT manages its own cache of directory entries. | |
123 | * c) *This* cache is indexed by on-disk location. | |
124 | * d) inode has an associated directory entry, all right, but | |
125 | * it may be unhashed. | |
126 | * e) currently entries are stored within struct inode. That should | |
127 | * change. | |
128 | * f) we deal with races in the following way: | |
129 | * 1. readdir() and lookup() do FAT-dir-cache lookup. | |
130 | * 2. rename() unhashes the F-d-c entry and rehashes it in | |
131 | * a new place. | |
132 | * 3. unlink() and rmdir() unhash F-d-c entry. | |
133 | * 4. fat_write_inode() checks whether the thing is unhashed. | |
134 | * If it is we silently return. If it isn't we do bread(), | |
135 | * check if the location is still valid and retry if it | |
136 | * isn't. Otherwise we do changes. | |
137 | * 5. Spinlock is used to protect hash/unhash/location check/lookup | |
138 | * 6. fat_clear_inode() unhashes the F-d-c entry. | |
139 | * 7. lookup() and readdir() do igrab() if they find a F-d-c entry | |
140 | * and consider negative result as cache miss. | |
141 | */ | |
142 | ||
143 | static void fat_hash_init(struct super_block *sb) | |
144 | { | |
145 | struct msdos_sb_info *sbi = MSDOS_SB(sb); | |
146 | int i; | |
147 | ||
148 | spin_lock_init(&sbi->inode_hash_lock); | |
149 | for (i = 0; i < FAT_HASH_SIZE; i++) | |
150 | INIT_HLIST_HEAD(&sbi->inode_hashtable[i]); | |
151 | } | |
152 | ||
153 | static inline unsigned long fat_hash(struct super_block *sb, loff_t i_pos) | |
154 | { | |
155 | unsigned long tmp = (unsigned long)i_pos | (unsigned long) sb; | |
156 | tmp = tmp + (tmp >> FAT_HASH_BITS) + (tmp >> FAT_HASH_BITS * 2); | |
157 | return tmp & FAT_HASH_MASK; | |
158 | } | |
159 | ||
160 | void fat_attach(struct inode *inode, loff_t i_pos) | |
161 | { | |
162 | struct super_block *sb = inode->i_sb; | |
163 | struct msdos_sb_info *sbi = MSDOS_SB(sb); | |
164 | ||
165 | spin_lock(&sbi->inode_hash_lock); | |
166 | MSDOS_I(inode)->i_pos = i_pos; | |
167 | hlist_add_head(&MSDOS_I(inode)->i_fat_hash, | |
168 | sbi->inode_hashtable + fat_hash(sb, i_pos)); | |
169 | spin_unlock(&sbi->inode_hash_lock); | |
170 | } | |
171 | ||
172 | EXPORT_SYMBOL(fat_attach); | |
173 | ||
174 | void fat_detach(struct inode *inode) | |
175 | { | |
176 | struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); | |
177 | spin_lock(&sbi->inode_hash_lock); | |
178 | MSDOS_I(inode)->i_pos = 0; | |
179 | hlist_del_init(&MSDOS_I(inode)->i_fat_hash); | |
180 | spin_unlock(&sbi->inode_hash_lock); | |
181 | } | |
182 | ||
183 | EXPORT_SYMBOL(fat_detach); | |
184 | ||
185 | struct inode *fat_iget(struct super_block *sb, loff_t i_pos) | |
186 | { | |
187 | struct msdos_sb_info *sbi = MSDOS_SB(sb); | |
188 | struct hlist_head *head = sbi->inode_hashtable + fat_hash(sb, i_pos); | |
189 | struct hlist_node *_p; | |
190 | struct msdos_inode_info *i; | |
191 | struct inode *inode = NULL; | |
192 | ||
193 | spin_lock(&sbi->inode_hash_lock); | |
194 | hlist_for_each_entry(i, _p, head, i_fat_hash) { | |
195 | BUG_ON(i->vfs_inode.i_sb != sb); | |
196 | if (i->i_pos != i_pos) | |
197 | continue; | |
198 | inode = igrab(&i->vfs_inode); | |
199 | if (inode) | |
200 | break; | |
201 | } | |
202 | spin_unlock(&sbi->inode_hash_lock); | |
203 | return inode; | |
204 | } | |
205 | ||
206 | static int is_exec(unsigned char *extension) | |
207 | { | |
208 | unsigned char *exe_extensions = "EXECOMBAT", *walk; | |
209 | ||
210 | for (walk = exe_extensions; *walk; walk += 3) | |
211 | if (!strncmp(extension, walk, 3)) | |
212 | return 1; | |
213 | return 0; | |
214 | } | |
215 | ||
216 | static int fat_calc_dir_size(struct inode *inode) | |
217 | { | |
218 | struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); | |
219 | int ret, fclus, dclus; | |
220 | ||
221 | inode->i_size = 0; | |
222 | if (MSDOS_I(inode)->i_start == 0) | |
223 | return 0; | |
224 | ||
225 | ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus); | |
226 | if (ret < 0) | |
227 | return ret; | |
228 | inode->i_size = (fclus + 1) << sbi->cluster_bits; | |
229 | ||
230 | return 0; | |
231 | } | |
232 | ||
233 | /* doesn't deal with root inode */ | |
234 | static int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de) | |
235 | { | |
236 | struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); | |
237 | int error; | |
238 | ||
239 | MSDOS_I(inode)->i_pos = 0; | |
240 | inode->i_uid = sbi->options.fs_uid; | |
241 | inode->i_gid = sbi->options.fs_gid; | |
242 | inode->i_version++; | |
243 | inode->i_generation = get_seconds(); | |
244 | ||
245 | if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) { | |
246 | inode->i_generation &= ~1; | |
247 | inode->i_mode = MSDOS_MKMODE(de->attr, | |
248 | S_IRWXUGO & ~sbi->options.fs_dmask) | S_IFDIR; | |
249 | inode->i_op = sbi->dir_ops; | |
250 | inode->i_fop = &fat_dir_operations; | |
251 | ||
252 | MSDOS_I(inode)->i_start = le16_to_cpu(de->start); | |
253 | if (sbi->fat_bits == 32) | |
254 | MSDOS_I(inode)->i_start |= (le16_to_cpu(de->starthi) << 16); | |
255 | ||
256 | MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start; | |
257 | error = fat_calc_dir_size(inode); | |
258 | if (error < 0) | |
259 | return error; | |
260 | MSDOS_I(inode)->mmu_private = inode->i_size; | |
261 | ||
262 | inode->i_nlink = fat_subdirs(inode); | |
263 | } else { /* not a directory */ | |
264 | inode->i_generation |= 1; | |
265 | inode->i_mode = MSDOS_MKMODE(de->attr, | |
266 | ((sbi->options.showexec && | |
267 | !is_exec(de->ext)) | |
268 | ? S_IRUGO|S_IWUGO : S_IRWXUGO) | |
269 | & ~sbi->options.fs_fmask) | S_IFREG; | |
270 | MSDOS_I(inode)->i_start = le16_to_cpu(de->start); | |
271 | if (sbi->fat_bits == 32) | |
272 | MSDOS_I(inode)->i_start |= (le16_to_cpu(de->starthi) << 16); | |
273 | ||
274 | MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start; | |
275 | inode->i_size = le32_to_cpu(de->size); | |
276 | inode->i_op = &fat_file_inode_operations; | |
277 | inode->i_fop = &fat_file_operations; | |
278 | inode->i_mapping->a_ops = &fat_aops; | |
279 | MSDOS_I(inode)->mmu_private = inode->i_size; | |
280 | } | |
281 | if (de->attr & ATTR_SYS) { | |
282 | if (sbi->options.sys_immutable) | |
283 | inode->i_flags |= S_IMMUTABLE; | |
284 | } | |
285 | MSDOS_I(inode)->i_attrs = de->attr & ATTR_UNUSED; | |
286 | /* this is as close to the truth as we can get ... */ | |
287 | inode->i_blksize = sbi->cluster_size; | |
288 | inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1)) | |
289 | & ~((loff_t)sbi->cluster_size - 1)) >> 9; | |
290 | inode->i_mtime.tv_sec = inode->i_atime.tv_sec = | |
291 | date_dos2unix(le16_to_cpu(de->time), le16_to_cpu(de->date)); | |
292 | inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = 0; | |
293 | if (sbi->options.isvfat) { | |
294 | int secs = de->ctime_cs / 100; | |
295 | int csecs = de->ctime_cs % 100; | |
296 | inode->i_ctime.tv_sec = | |
297 | date_dos2unix(le16_to_cpu(de->ctime), | |
298 | le16_to_cpu(de->cdate)) + secs; | |
299 | inode->i_ctime.tv_nsec = csecs * 10000000; | |
300 | } else | |
301 | inode->i_ctime = inode->i_mtime; | |
302 | ||
303 | return 0; | |
304 | } | |
305 | ||
306 | struct inode *fat_build_inode(struct super_block *sb, | |
307 | struct msdos_dir_entry *de, loff_t i_pos) | |
308 | { | |
309 | struct inode *inode; | |
310 | int err; | |
311 | ||
312 | inode = fat_iget(sb, i_pos); | |
313 | if (inode) | |
314 | goto out; | |
315 | inode = new_inode(sb); | |
316 | if (!inode) { | |
317 | inode = ERR_PTR(-ENOMEM); | |
318 | goto out; | |
319 | } | |
320 | inode->i_ino = iunique(sb, MSDOS_ROOT_INO); | |
321 | inode->i_version = 1; | |
322 | err = fat_fill_inode(inode, de); | |
323 | if (err) { | |
324 | iput(inode); | |
325 | inode = ERR_PTR(err); | |
326 | goto out; | |
327 | } | |
328 | fat_attach(inode, i_pos); | |
329 | insert_inode_hash(inode); | |
330 | out: | |
331 | return inode; | |
332 | } | |
333 | ||
334 | EXPORT_SYMBOL(fat_build_inode); | |
335 | ||
336 | static void fat_delete_inode(struct inode *inode) | |
337 | { | |
338 | if (!is_bad_inode(inode)) { | |
339 | inode->i_size = 0; | |
340 | fat_truncate(inode); | |
341 | } | |
342 | clear_inode(inode); | |
343 | } | |
344 | ||
345 | static void fat_clear_inode(struct inode *inode) | |
346 | { | |
347 | struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); | |
348 | ||
349 | if (is_bad_inode(inode)) | |
350 | return; | |
351 | lock_kernel(); | |
352 | spin_lock(&sbi->inode_hash_lock); | |
353 | fat_cache_inval_inode(inode); | |
354 | hlist_del_init(&MSDOS_I(inode)->i_fat_hash); | |
355 | spin_unlock(&sbi->inode_hash_lock); | |
356 | unlock_kernel(); | |
357 | } | |
358 | ||
359 | static void fat_put_super(struct super_block *sb) | |
360 | { | |
361 | struct msdos_sb_info *sbi = MSDOS_SB(sb); | |
362 | ||
363 | if (!(sb->s_flags & MS_RDONLY)) | |
364 | fat_clusters_flush(sb); | |
365 | ||
366 | if (sbi->nls_disk) { | |
367 | unload_nls(sbi->nls_disk); | |
368 | sbi->nls_disk = NULL; | |
369 | sbi->options.codepage = fat_default_codepage; | |
370 | } | |
371 | if (sbi->nls_io) { | |
372 | unload_nls(sbi->nls_io); | |
373 | sbi->nls_io = NULL; | |
374 | } | |
375 | if (sbi->options.iocharset != fat_default_iocharset) { | |
376 | kfree(sbi->options.iocharset); | |
377 | sbi->options.iocharset = fat_default_iocharset; | |
378 | } | |
379 | ||
380 | sb->s_fs_info = NULL; | |
381 | kfree(sbi); | |
382 | } | |
383 | ||
384 | static kmem_cache_t *fat_inode_cachep; | |
385 | ||
386 | static struct inode *fat_alloc_inode(struct super_block *sb) | |
387 | { | |
388 | struct msdos_inode_info *ei; | |
389 | ei = kmem_cache_alloc(fat_inode_cachep, SLAB_KERNEL); | |
390 | if (!ei) | |
391 | return NULL; | |
392 | return &ei->vfs_inode; | |
393 | } | |
394 | ||
395 | static void fat_destroy_inode(struct inode *inode) | |
396 | { | |
397 | kmem_cache_free(fat_inode_cachep, MSDOS_I(inode)); | |
398 | } | |
399 | ||
400 | static void init_once(void * foo, kmem_cache_t * cachep, unsigned long flags) | |
401 | { | |
402 | struct msdos_inode_info *ei = (struct msdos_inode_info *)foo; | |
403 | ||
404 | if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) == | |
405 | SLAB_CTOR_CONSTRUCTOR) { | |
406 | spin_lock_init(&ei->cache_lru_lock); | |
407 | ei->nr_caches = 0; | |
408 | ei->cache_valid_id = FAT_CACHE_VALID + 1; | |
409 | INIT_LIST_HEAD(&ei->cache_lru); | |
410 | INIT_HLIST_NODE(&ei->i_fat_hash); | |
411 | inode_init_once(&ei->vfs_inode); | |
412 | } | |
413 | } | |
414 | ||
415 | static int __init fat_init_inodecache(void) | |
416 | { | |
417 | fat_inode_cachep = kmem_cache_create("fat_inode_cache", | |
418 | sizeof(struct msdos_inode_info), | |
419 | 0, SLAB_RECLAIM_ACCOUNT, | |
420 | init_once, NULL); | |
421 | if (fat_inode_cachep == NULL) | |
422 | return -ENOMEM; | |
423 | return 0; | |
424 | } | |
425 | ||
426 | static void __exit fat_destroy_inodecache(void) | |
427 | { | |
428 | if (kmem_cache_destroy(fat_inode_cachep)) | |
429 | printk(KERN_INFO "fat_inode_cache: not all structures were freed\n"); | |
430 | } | |
431 | ||
432 | static int fat_remount(struct super_block *sb, int *flags, char *data) | |
433 | { | |
434 | struct msdos_sb_info *sbi = MSDOS_SB(sb); | |
435 | *flags |= MS_NODIRATIME | (sbi->options.isvfat ? 0 : MS_NOATIME); | |
436 | return 0; | |
437 | } | |
438 | ||
439 | static int fat_statfs(struct super_block *sb, struct kstatfs *buf) | |
440 | { | |
441 | struct msdos_sb_info *sbi = MSDOS_SB(sb); | |
442 | ||
443 | /* If the count of free cluster is still unknown, counts it here. */ | |
444 | if (sbi->free_clusters == -1) { | |
445 | int err = fat_count_free_clusters(sb); | |
446 | if (err) | |
447 | return err; | |
448 | } | |
449 | ||
450 | buf->f_type = sb->s_magic; | |
451 | buf->f_bsize = sbi->cluster_size; | |
452 | buf->f_blocks = sbi->max_cluster - FAT_START_ENT; | |
453 | buf->f_bfree = sbi->free_clusters; | |
454 | buf->f_bavail = sbi->free_clusters; | |
455 | buf->f_namelen = sbi->options.isvfat ? 260 : 12; | |
456 | ||
457 | return 0; | |
458 | } | |
459 | ||
460 | static int fat_write_inode(struct inode *inode, int wait) | |
461 | { | |
462 | struct super_block *sb = inode->i_sb; | |
463 | struct msdos_sb_info *sbi = MSDOS_SB(sb); | |
464 | struct buffer_head *bh; | |
465 | struct msdos_dir_entry *raw_entry; | |
466 | loff_t i_pos; | |
467 | int err = 0; | |
468 | ||
469 | retry: | |
470 | i_pos = MSDOS_I(inode)->i_pos; | |
471 | if (inode->i_ino == MSDOS_ROOT_INO || !i_pos) | |
472 | return 0; | |
473 | ||
474 | lock_kernel(); | |
475 | bh = sb_bread(sb, i_pos >> sbi->dir_per_block_bits); | |
476 | if (!bh) { | |
477 | printk(KERN_ERR "FAT: unable to read inode block " | |
478 | "for updating (i_pos %lld)\n", i_pos); | |
479 | err = -EIO; | |
480 | goto out; | |
481 | } | |
482 | spin_lock(&sbi->inode_hash_lock); | |
483 | if (i_pos != MSDOS_I(inode)->i_pos) { | |
484 | spin_unlock(&sbi->inode_hash_lock); | |
485 | brelse(bh); | |
486 | unlock_kernel(); | |
487 | goto retry; | |
488 | } | |
489 | ||
490 | raw_entry = &((struct msdos_dir_entry *) (bh->b_data)) | |
491 | [i_pos & (sbi->dir_per_block - 1)]; | |
492 | if (S_ISDIR(inode->i_mode)) | |
493 | raw_entry->size = 0; | |
494 | else | |
495 | raw_entry->size = cpu_to_le32(inode->i_size); | |
496 | raw_entry->attr = fat_attr(inode); | |
497 | raw_entry->start = cpu_to_le16(MSDOS_I(inode)->i_logstart); | |
498 | raw_entry->starthi = cpu_to_le16(MSDOS_I(inode)->i_logstart >> 16); | |
499 | fat_date_unix2dos(inode->i_mtime.tv_sec, &raw_entry->time, &raw_entry->date); | |
500 | if (sbi->options.isvfat) { | |
501 | fat_date_unix2dos(inode->i_ctime.tv_sec,&raw_entry->ctime,&raw_entry->cdate); | |
502 | raw_entry->ctime_cs = (inode->i_ctime.tv_sec & 1) * 100 + | |
503 | inode->i_ctime.tv_nsec / 10000000; | |
504 | } | |
505 | spin_unlock(&sbi->inode_hash_lock); | |
506 | mark_buffer_dirty(bh); | |
507 | if (wait) | |
508 | err = sync_dirty_buffer(bh); | |
509 | brelse(bh); | |
510 | out: | |
511 | unlock_kernel(); | |
512 | return err; | |
513 | } | |
514 | ||
515 | int fat_sync_inode(struct inode *inode) | |
516 | { | |
517 | return fat_write_inode(inode, 1); | |
518 | } | |
519 | ||
520 | EXPORT_SYMBOL(fat_sync_inode); | |
521 | ||
522 | static int fat_show_options(struct seq_file *m, struct vfsmount *mnt); | |
523 | static struct super_operations fat_sops = { | |
524 | .alloc_inode = fat_alloc_inode, | |
525 | .destroy_inode = fat_destroy_inode, | |
526 | .write_inode = fat_write_inode, | |
527 | .delete_inode = fat_delete_inode, | |
528 | .put_super = fat_put_super, | |
529 | .statfs = fat_statfs, | |
530 | .clear_inode = fat_clear_inode, | |
531 | .remount_fs = fat_remount, | |
532 | ||
533 | .read_inode = make_bad_inode, | |
534 | ||
535 | .show_options = fat_show_options, | |
536 | }; | |
537 | ||
538 | /* | |
539 | * a FAT file handle with fhtype 3 is | |
540 | * 0/ i_ino - for fast, reliable lookup if still in the cache | |
541 | * 1/ i_generation - to see if i_ino is still valid | |
542 | * bit 0 == 0 iff directory | |
543 | * 2/ i_pos(8-39) - if ino has changed, but still in cache | |
544 | * 3/ i_pos(4-7)|i_logstart - to semi-verify inode found at i_pos | |
545 | * 4/ i_pos(0-3)|parent->i_logstart - maybe used to hunt for the file on disc | |
546 | * | |
547 | * Hack for NFSv2: Maximum FAT entry number is 28bits and maximum | |
548 | * i_pos is 40bits (blocknr(32) + dir offset(8)), so two 4bits | |
549 | * of i_logstart is used to store the directory entry offset. | |
550 | */ | |
551 | ||
552 | static struct dentry * | |
553 | fat_decode_fh(struct super_block *sb, __u32 *fh, int len, int fhtype, | |
554 | int (*acceptable)(void *context, struct dentry *de), | |
555 | void *context) | |
556 | { | |
557 | if (fhtype != 3) | |
558 | return ERR_PTR(-ESTALE); | |
559 | if (len < 5) | |
560 | return ERR_PTR(-ESTALE); | |
561 | ||
562 | return sb->s_export_op->find_exported_dentry(sb, fh, NULL, acceptable, context); | |
563 | } | |
564 | ||
565 | static struct dentry *fat_get_dentry(struct super_block *sb, void *inump) | |
566 | { | |
567 | struct inode *inode = NULL; | |
568 | struct dentry *result; | |
569 | __u32 *fh = inump; | |
570 | ||
571 | inode = iget(sb, fh[0]); | |
572 | if (!inode || is_bad_inode(inode) || inode->i_generation != fh[1]) { | |
573 | if (inode) | |
574 | iput(inode); | |
575 | inode = NULL; | |
576 | } | |
577 | if (!inode) { | |
578 | loff_t i_pos; | |
579 | int i_logstart = fh[3] & 0x0fffffff; | |
580 | ||
581 | i_pos = (loff_t)fh[2] << 8; | |
582 | i_pos |= ((fh[3] >> 24) & 0xf0) | (fh[4] >> 28); | |
583 | ||
584 | /* try 2 - see if i_pos is in F-d-c | |
585 | * require i_logstart to be the same | |
586 | * Will fail if you truncate and then re-write | |
587 | */ | |
588 | ||
589 | inode = fat_iget(sb, i_pos); | |
590 | if (inode && MSDOS_I(inode)->i_logstart != i_logstart) { | |
591 | iput(inode); | |
592 | inode = NULL; | |
593 | } | |
594 | } | |
595 | if (!inode) { | |
596 | /* For now, do nothing | |
597 | * What we could do is: | |
598 | * follow the file starting at fh[4], and record | |
599 | * the ".." entry, and the name of the fh[2] entry. | |
600 | * The follow the ".." file finding the next step up. | |
601 | * This way we build a path to the root of | |
602 | * the tree. If this works, we lookup the path and so | |
603 | * get this inode into the cache. | |
604 | * Finally try the fat_iget lookup again | |
605 | * If that fails, then weare totally out of luck | |
606 | * But all that is for another day | |
607 | */ | |
608 | } | |
609 | if (!inode) | |
610 | return ERR_PTR(-ESTALE); | |
611 | ||
612 | ||
613 | /* now to find a dentry. | |
614 | * If possible, get a well-connected one | |
615 | */ | |
616 | result = d_alloc_anon(inode); | |
617 | if (result == NULL) { | |
618 | iput(inode); | |
619 | return ERR_PTR(-ENOMEM); | |
620 | } | |
621 | result->d_op = sb->s_root->d_op; | |
622 | return result; | |
623 | } | |
624 | ||
625 | static int | |
626 | fat_encode_fh(struct dentry *de, __u32 *fh, int *lenp, int connectable) | |
627 | { | |
628 | int len = *lenp; | |
629 | struct inode *inode = de->d_inode; | |
630 | u32 ipos_h, ipos_m, ipos_l; | |
631 | ||
632 | if (len < 5) | |
633 | return 255; /* no room */ | |
634 | ||
635 | ipos_h = MSDOS_I(inode)->i_pos >> 8; | |
636 | ipos_m = (MSDOS_I(inode)->i_pos & 0xf0) << 24; | |
637 | ipos_l = (MSDOS_I(inode)->i_pos & 0x0f) << 28; | |
638 | *lenp = 5; | |
639 | fh[0] = inode->i_ino; | |
640 | fh[1] = inode->i_generation; | |
641 | fh[2] = ipos_h; | |
642 | fh[3] = ipos_m | MSDOS_I(inode)->i_logstart; | |
643 | spin_lock(&de->d_lock); | |
644 | fh[4] = ipos_l | MSDOS_I(de->d_parent->d_inode)->i_logstart; | |
645 | spin_unlock(&de->d_lock); | |
646 | return 3; | |
647 | } | |
648 | ||
649 | static struct dentry *fat_get_parent(struct dentry *child) | |
650 | { | |
651 | struct buffer_head *bh; | |
652 | struct msdos_dir_entry *de; | |
653 | loff_t i_pos; | |
654 | struct dentry *parent; | |
655 | struct inode *inode; | |
656 | int err; | |
657 | ||
658 | lock_kernel(); | |
659 | ||
660 | err = fat_get_dotdot_entry(child->d_inode, &bh, &de, &i_pos); | |
661 | if (err) { | |
662 | parent = ERR_PTR(err); | |
663 | goto out; | |
664 | } | |
665 | inode = fat_build_inode(child->d_sb, de, i_pos); | |
666 | brelse(bh); | |
667 | if (IS_ERR(inode)) { | |
668 | parent = ERR_PTR(PTR_ERR(inode)); | |
669 | goto out; | |
670 | } | |
671 | parent = d_alloc_anon(inode); | |
672 | if (!parent) { | |
673 | iput(inode); | |
674 | parent = ERR_PTR(-ENOMEM); | |
675 | } | |
676 | out: | |
677 | unlock_kernel(); | |
678 | ||
679 | return parent; | |
680 | } | |
681 | ||
682 | static struct export_operations fat_export_ops = { | |
683 | .decode_fh = fat_decode_fh, | |
684 | .encode_fh = fat_encode_fh, | |
685 | .get_dentry = fat_get_dentry, | |
686 | .get_parent = fat_get_parent, | |
687 | }; | |
688 | ||
689 | static int fat_show_options(struct seq_file *m, struct vfsmount *mnt) | |
690 | { | |
691 | struct msdos_sb_info *sbi = MSDOS_SB(mnt->mnt_sb); | |
692 | struct fat_mount_options *opts = &sbi->options; | |
693 | int isvfat = opts->isvfat; | |
694 | ||
695 | if (opts->fs_uid != 0) | |
696 | seq_printf(m, ",uid=%u", opts->fs_uid); | |
697 | if (opts->fs_gid != 0) | |
698 | seq_printf(m, ",gid=%u", opts->fs_gid); | |
699 | seq_printf(m, ",fmask=%04o", opts->fs_fmask); | |
700 | seq_printf(m, ",dmask=%04o", opts->fs_dmask); | |
701 | if (sbi->nls_disk) | |
702 | seq_printf(m, ",codepage=%s", sbi->nls_disk->charset); | |
703 | if (isvfat) { | |
704 | if (sbi->nls_io) | |
705 | seq_printf(m, ",iocharset=%s", sbi->nls_io->charset); | |
706 | ||
707 | switch (opts->shortname) { | |
708 | case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95: | |
709 | seq_puts(m, ",shortname=win95"); | |
710 | break; | |
711 | case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT: | |
712 | seq_puts(m, ",shortname=winnt"); | |
713 | break; | |
714 | case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95: | |
715 | seq_puts(m, ",shortname=mixed"); | |
716 | break; | |
717 | case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95: | |
718 | /* seq_puts(m, ",shortname=lower"); */ | |
719 | break; | |
720 | default: | |
721 | seq_puts(m, ",shortname=unknown"); | |
722 | break; | |
723 | } | |
724 | } | |
725 | if (opts->name_check != 'n') | |
726 | seq_printf(m, ",check=%c", opts->name_check); | |
727 | if (opts->quiet) | |
728 | seq_puts(m, ",quiet"); | |
729 | if (opts->showexec) | |
730 | seq_puts(m, ",showexec"); | |
731 | if (opts->sys_immutable) | |
732 | seq_puts(m, ",sys_immutable"); | |
733 | if (!isvfat) { | |
734 | if (opts->dotsOK) | |
735 | seq_puts(m, ",dotsOK=yes"); | |
736 | if (opts->nocase) | |
737 | seq_puts(m, ",nocase"); | |
738 | } else { | |
739 | if (opts->utf8) | |
740 | seq_puts(m, ",utf8"); | |
741 | if (opts->unicode_xlate) | |
742 | seq_puts(m, ",uni_xlate"); | |
743 | if (!opts->numtail) | |
744 | seq_puts(m, ",nonumtail"); | |
745 | } | |
746 | ||
747 | return 0; | |
748 | } | |
749 | ||
750 | enum { | |
751 | Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid, | |
752 | Opt_umask, Opt_dmask, Opt_fmask, Opt_codepage, Opt_nocase, | |
753 | Opt_quiet, Opt_showexec, Opt_debug, Opt_immutable, | |
754 | Opt_dots, Opt_nodots, | |
755 | Opt_charset, Opt_shortname_lower, Opt_shortname_win95, | |
756 | Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes, | |
757 | Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes, | |
758 | Opt_obsolate, Opt_err, | |
759 | }; | |
760 | ||
761 | static match_table_t fat_tokens = { | |
762 | {Opt_check_r, "check=relaxed"}, | |
763 | {Opt_check_s, "check=strict"}, | |
764 | {Opt_check_n, "check=normal"}, | |
765 | {Opt_check_r, "check=r"}, | |
766 | {Opt_check_s, "check=s"}, | |
767 | {Opt_check_n, "check=n"}, | |
768 | {Opt_uid, "uid=%u"}, | |
769 | {Opt_gid, "gid=%u"}, | |
770 | {Opt_umask, "umask=%o"}, | |
771 | {Opt_dmask, "dmask=%o"}, | |
772 | {Opt_fmask, "fmask=%o"}, | |
773 | {Opt_codepage, "codepage=%u"}, | |
774 | {Opt_nocase, "nocase"}, | |
775 | {Opt_quiet, "quiet"}, | |
776 | {Opt_showexec, "showexec"}, | |
777 | {Opt_debug, "debug"}, | |
778 | {Opt_immutable, "sys_immutable"}, | |
779 | {Opt_obsolate, "conv=binary"}, | |
780 | {Opt_obsolate, "conv=text"}, | |
781 | {Opt_obsolate, "conv=auto"}, | |
782 | {Opt_obsolate, "conv=b"}, | |
783 | {Opt_obsolate, "conv=t"}, | |
784 | {Opt_obsolate, "conv=a"}, | |
785 | {Opt_obsolate, "fat=%u"}, | |
786 | {Opt_obsolate, "blocksize=%u"}, | |
787 | {Opt_obsolate, "cvf_format=%20s"}, | |
788 | {Opt_obsolate, "cvf_options=%100s"}, | |
789 | {Opt_obsolate, "posix"}, | |
790 | {Opt_err, NULL} | |
791 | }; | |
792 | static match_table_t msdos_tokens = { | |
793 | {Opt_nodots, "nodots"}, | |
794 | {Opt_nodots, "dotsOK=no"}, | |
795 | {Opt_dots, "dots"}, | |
796 | {Opt_dots, "dotsOK=yes"}, | |
797 | {Opt_err, NULL} | |
798 | }; | |
799 | static match_table_t vfat_tokens = { | |
800 | {Opt_charset, "iocharset=%s"}, | |
801 | {Opt_shortname_lower, "shortname=lower"}, | |
802 | {Opt_shortname_win95, "shortname=win95"}, | |
803 | {Opt_shortname_winnt, "shortname=winnt"}, | |
804 | {Opt_shortname_mixed, "shortname=mixed"}, | |
805 | {Opt_utf8_no, "utf8=0"}, /* 0 or no or false */ | |
806 | {Opt_utf8_no, "utf8=no"}, | |
807 | {Opt_utf8_no, "utf8=false"}, | |
808 | {Opt_utf8_yes, "utf8=1"}, /* empty or 1 or yes or true */ | |
809 | {Opt_utf8_yes, "utf8=yes"}, | |
810 | {Opt_utf8_yes, "utf8=true"}, | |
811 | {Opt_utf8_yes, "utf8"}, | |
812 | {Opt_uni_xl_no, "uni_xlate=0"}, /* 0 or no or false */ | |
813 | {Opt_uni_xl_no, "uni_xlate=no"}, | |
814 | {Opt_uni_xl_no, "uni_xlate=false"}, | |
815 | {Opt_uni_xl_yes, "uni_xlate=1"}, /* empty or 1 or yes or true */ | |
816 | {Opt_uni_xl_yes, "uni_xlate=yes"}, | |
817 | {Opt_uni_xl_yes, "uni_xlate=true"}, | |
818 | {Opt_uni_xl_yes, "uni_xlate"}, | |
819 | {Opt_nonumtail_no, "nonumtail=0"}, /* 0 or no or false */ | |
820 | {Opt_nonumtail_no, "nonumtail=no"}, | |
821 | {Opt_nonumtail_no, "nonumtail=false"}, | |
822 | {Opt_nonumtail_yes, "nonumtail=1"}, /* empty or 1 or yes or true */ | |
823 | {Opt_nonumtail_yes, "nonumtail=yes"}, | |
824 | {Opt_nonumtail_yes, "nonumtail=true"}, | |
825 | {Opt_nonumtail_yes, "nonumtail"}, | |
826 | {Opt_err, NULL} | |
827 | }; | |
828 | ||
829 | static int parse_options(char *options, int is_vfat, int *debug, | |
830 | struct fat_mount_options *opts) | |
831 | { | |
832 | char *p; | |
833 | substring_t args[MAX_OPT_ARGS]; | |
834 | int option; | |
835 | char *iocharset; | |
836 | ||
837 | opts->isvfat = is_vfat; | |
838 | ||
839 | opts->fs_uid = current->uid; | |
840 | opts->fs_gid = current->gid; | |
841 | opts->fs_fmask = opts->fs_dmask = current->fs->umask; | |
842 | opts->codepage = fat_default_codepage; | |
843 | opts->iocharset = fat_default_iocharset; | |
844 | if (is_vfat) | |
845 | opts->shortname = VFAT_SFN_DISPLAY_LOWER|VFAT_SFN_CREATE_WIN95; | |
846 | else | |
847 | opts->shortname = 0; | |
848 | opts->name_check = 'n'; | |
849 | opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0; | |
850 | opts->utf8 = opts->unicode_xlate = 0; | |
851 | opts->numtail = 1; | |
852 | opts->nocase = 0; | |
853 | *debug = 0; | |
854 | ||
855 | if (!options) | |
856 | return 0; | |
857 | ||
858 | while ((p = strsep(&options, ",")) != NULL) { | |
859 | int token; | |
860 | if (!*p) | |
861 | continue; | |
862 | ||
863 | token = match_token(p, fat_tokens, args); | |
864 | if (token == Opt_err) { | |
865 | if (is_vfat) | |
866 | token = match_token(p, vfat_tokens, args); | |
867 | else | |
868 | token = match_token(p, msdos_tokens, args); | |
869 | } | |
870 | switch (token) { | |
871 | case Opt_check_s: | |
872 | opts->name_check = 's'; | |
873 | break; | |
874 | case Opt_check_r: | |
875 | opts->name_check = 'r'; | |
876 | break; | |
877 | case Opt_check_n: | |
878 | opts->name_check = 'n'; | |
879 | break; | |
880 | case Opt_nocase: | |
881 | if (!is_vfat) | |
882 | opts->nocase = 1; | |
883 | else { | |
884 | /* for backward compatibility */ | |
885 | opts->shortname = VFAT_SFN_DISPLAY_WIN95 | |
886 | | VFAT_SFN_CREATE_WIN95; | |
887 | } | |
888 | break; | |
889 | case Opt_quiet: | |
890 | opts->quiet = 1; | |
891 | break; | |
892 | case Opt_showexec: | |
893 | opts->showexec = 1; | |
894 | break; | |
895 | case Opt_debug: | |
896 | *debug = 1; | |
897 | break; | |
898 | case Opt_immutable: | |
899 | opts->sys_immutable = 1; | |
900 | break; | |
901 | case Opt_uid: | |
902 | if (match_int(&args[0], &option)) | |
903 | return 0; | |
904 | opts->fs_uid = option; | |
905 | break; | |
906 | case Opt_gid: | |
907 | if (match_int(&args[0], &option)) | |
908 | return 0; | |
909 | opts->fs_gid = option; | |
910 | break; | |
911 | case Opt_umask: | |
912 | if (match_octal(&args[0], &option)) | |
913 | return 0; | |
914 | opts->fs_fmask = opts->fs_dmask = option; | |
915 | break; | |
916 | case Opt_dmask: | |
917 | if (match_octal(&args[0], &option)) | |
918 | return 0; | |
919 | opts->fs_dmask = option; | |
920 | break; | |
921 | case Opt_fmask: | |
922 | if (match_octal(&args[0], &option)) | |
923 | return 0; | |
924 | opts->fs_fmask = option; | |
925 | break; | |
926 | case Opt_codepage: | |
927 | if (match_int(&args[0], &option)) | |
928 | return 0; | |
929 | opts->codepage = option; | |
930 | break; | |
931 | ||
932 | /* msdos specific */ | |
933 | case Opt_dots: | |
934 | opts->dotsOK = 1; | |
935 | break; | |
936 | case Opt_nodots: | |
937 | opts->dotsOK = 0; | |
938 | break; | |
939 | ||
940 | /* vfat specific */ | |
941 | case Opt_charset: | |
942 | if (opts->iocharset != fat_default_iocharset) | |
943 | kfree(opts->iocharset); | |
944 | iocharset = match_strdup(&args[0]); | |
945 | if (!iocharset) | |
946 | return -ENOMEM; | |
947 | opts->iocharset = iocharset; | |
948 | break; | |
949 | case Opt_shortname_lower: | |
950 | opts->shortname = VFAT_SFN_DISPLAY_LOWER | |
951 | | VFAT_SFN_CREATE_WIN95; | |
952 | break; | |
953 | case Opt_shortname_win95: | |
954 | opts->shortname = VFAT_SFN_DISPLAY_WIN95 | |
955 | | VFAT_SFN_CREATE_WIN95; | |
956 | break; | |
957 | case Opt_shortname_winnt: | |
958 | opts->shortname = VFAT_SFN_DISPLAY_WINNT | |
959 | | VFAT_SFN_CREATE_WINNT; | |
960 | break; | |
961 | case Opt_shortname_mixed: | |
962 | opts->shortname = VFAT_SFN_DISPLAY_WINNT | |
963 | | VFAT_SFN_CREATE_WIN95; | |
964 | break; | |
965 | case Opt_utf8_no: /* 0 or no or false */ | |
966 | opts->utf8 = 0; | |
967 | break; | |
968 | case Opt_utf8_yes: /* empty or 1 or yes or true */ | |
969 | opts->utf8 = 1; | |
970 | break; | |
971 | case Opt_uni_xl_no: /* 0 or no or false */ | |
972 | opts->unicode_xlate = 0; | |
973 | break; | |
974 | case Opt_uni_xl_yes: /* empty or 1 or yes or true */ | |
975 | opts->unicode_xlate = 1; | |
976 | break; | |
977 | case Opt_nonumtail_no: /* 0 or no or false */ | |
978 | opts->numtail = 1; /* negated option */ | |
979 | break; | |
980 | case Opt_nonumtail_yes: /* empty or 1 or yes or true */ | |
981 | opts->numtail = 0; /* negated option */ | |
982 | break; | |
983 | ||
984 | /* obsolete mount options */ | |
985 | case Opt_obsolate: | |
986 | printk(KERN_INFO "FAT: \"%s\" option is obsolete, " | |
987 | "not supported now\n", p); | |
988 | break; | |
989 | /* unknown option */ | |
990 | default: | |
991 | printk(KERN_ERR "FAT: Unrecognized mount option \"%s\" " | |
992 | "or missing value\n", p); | |
993 | return -EINVAL; | |
994 | } | |
995 | } | |
996 | /* UTF8 doesn't provide FAT semantics */ | |
997 | if (!strcmp(opts->iocharset, "utf8")) { | |
998 | printk(KERN_ERR "FAT: utf8 is not a recommended IO charset" | |
999 | " for FAT filesystems, filesystem will be case sensitive!\n"); | |
1000 | } | |
1001 | ||
1002 | if (opts->unicode_xlate) | |
1003 | opts->utf8 = 0; | |
1004 | ||
1005 | return 0; | |
1006 | } | |
1007 | ||
1008 | static int fat_read_root(struct inode *inode) | |
1009 | { | |
1010 | struct super_block *sb = inode->i_sb; | |
1011 | struct msdos_sb_info *sbi = MSDOS_SB(sb); | |
1012 | int error; | |
1013 | ||
1014 | MSDOS_I(inode)->i_pos = 0; | |
1015 | inode->i_uid = sbi->options.fs_uid; | |
1016 | inode->i_gid = sbi->options.fs_gid; | |
1017 | inode->i_version++; | |
1018 | inode->i_generation = 0; | |
1019 | inode->i_mode = (S_IRWXUGO & ~sbi->options.fs_dmask) | S_IFDIR; | |
1020 | inode->i_op = sbi->dir_ops; | |
1021 | inode->i_fop = &fat_dir_operations; | |
1022 | if (sbi->fat_bits == 32) { | |
1023 | MSDOS_I(inode)->i_start = sbi->root_cluster; | |
1024 | error = fat_calc_dir_size(inode); | |
1025 | if (error < 0) | |
1026 | return error; | |
1027 | } else { | |
1028 | MSDOS_I(inode)->i_start = 0; | |
1029 | inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry); | |
1030 | } | |
1031 | inode->i_blksize = sbi->cluster_size; | |
1032 | inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1)) | |
1033 | & ~((loff_t)sbi->cluster_size - 1)) >> 9; | |
1034 | MSDOS_I(inode)->i_logstart = 0; | |
1035 | MSDOS_I(inode)->mmu_private = inode->i_size; | |
1036 | ||
1037 | MSDOS_I(inode)->i_attrs = ATTR_NONE; | |
1038 | inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0; | |
1039 | inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0; | |
1040 | inode->i_nlink = fat_subdirs(inode)+2; | |
1041 | ||
1042 | return 0; | |
1043 | } | |
1044 | ||
1045 | /* | |
1046 | * Read the super block of an MS-DOS FS. | |
1047 | */ | |
1048 | int fat_fill_super(struct super_block *sb, void *data, int silent, | |
1049 | struct inode_operations *fs_dir_inode_ops, int isvfat) | |
1050 | { | |
1051 | struct inode *root_inode = NULL; | |
1052 | struct buffer_head *bh; | |
1053 | struct fat_boot_sector *b; | |
1054 | struct msdos_sb_info *sbi; | |
1055 | u16 logical_sector_size; | |
1056 | u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors; | |
1057 | int debug; | |
1058 | unsigned int media; | |
1059 | long error; | |
1060 | char buf[50]; | |
1061 | ||
1062 | sbi = kmalloc(sizeof(struct msdos_sb_info), GFP_KERNEL); | |
1063 | if (!sbi) | |
1064 | return -ENOMEM; | |
1065 | sb->s_fs_info = sbi; | |
1066 | memset(sbi, 0, sizeof(struct msdos_sb_info)); | |
1067 | ||
1068 | sb->s_flags |= MS_NODIRATIME; | |
1069 | sb->s_magic = MSDOS_SUPER_MAGIC; | |
1070 | sb->s_op = &fat_sops; | |
1071 | sb->s_export_op = &fat_export_ops; | |
1072 | sbi->dir_ops = fs_dir_inode_ops; | |
1073 | ||
1074 | error = parse_options(data, isvfat, &debug, &sbi->options); | |
1075 | if (error) | |
1076 | goto out_fail; | |
1077 | ||
1078 | error = -EIO; | |
1079 | sb_min_blocksize(sb, 512); | |
1080 | bh = sb_bread(sb, 0); | |
1081 | if (bh == NULL) { | |
1082 | printk(KERN_ERR "FAT: unable to read boot sector\n"); | |
1083 | goto out_fail; | |
1084 | } | |
1085 | ||
1086 | b = (struct fat_boot_sector *) bh->b_data; | |
1087 | if (!b->reserved) { | |
1088 | if (!silent) | |
1089 | printk(KERN_ERR "FAT: bogus number of reserved sectors\n"); | |
1090 | brelse(bh); | |
1091 | goto out_invalid; | |
1092 | } | |
1093 | if (!b->fats) { | |
1094 | if (!silent) | |
1095 | printk(KERN_ERR "FAT: bogus number of FAT structure\n"); | |
1096 | brelse(bh); | |
1097 | goto out_invalid; | |
1098 | } | |
1099 | ||
1100 | /* | |
1101 | * Earlier we checked here that b->secs_track and b->head are nonzero, | |
1102 | * but it turns out valid FAT filesystems can have zero there. | |
1103 | */ | |
1104 | ||
1105 | media = b->media; | |
1106 | if (!FAT_VALID_MEDIA(media)) { | |
1107 | if (!silent) | |
1108 | printk(KERN_ERR "FAT: invalid media value (0x%02x)\n", | |
1109 | media); | |
1110 | brelse(bh); | |
1111 | goto out_invalid; | |
1112 | } | |
1113 | logical_sector_size = | |
1114 | le16_to_cpu(get_unaligned((__le16 *)&b->sector_size)); | |
1115 | if (!logical_sector_size | |
1116 | || (logical_sector_size & (logical_sector_size - 1)) | |
1117 | || (logical_sector_size < 512) | |
1118 | || (PAGE_CACHE_SIZE < logical_sector_size)) { | |
1119 | if (!silent) | |
1120 | printk(KERN_ERR "FAT: bogus logical sector size %u\n", | |
1121 | logical_sector_size); | |
1122 | brelse(bh); | |
1123 | goto out_invalid; | |
1124 | } | |
1125 | sbi->sec_per_clus = b->sec_per_clus; | |
1126 | if (!sbi->sec_per_clus | |
1127 | || (sbi->sec_per_clus & (sbi->sec_per_clus - 1))) { | |
1128 | if (!silent) | |
1129 | printk(KERN_ERR "FAT: bogus sectors per cluster %u\n", | |
1130 | sbi->sec_per_clus); | |
1131 | brelse(bh); | |
1132 | goto out_invalid; | |
1133 | } | |
1134 | ||
1135 | if (logical_sector_size < sb->s_blocksize) { | |
1136 | printk(KERN_ERR "FAT: logical sector size too small for device" | |
1137 | " (logical sector size = %u)\n", logical_sector_size); | |
1138 | brelse(bh); | |
1139 | goto out_fail; | |
1140 | } | |
1141 | if (logical_sector_size > sb->s_blocksize) { | |
1142 | brelse(bh); | |
1143 | ||
1144 | if (!sb_set_blocksize(sb, logical_sector_size)) { | |
1145 | printk(KERN_ERR "FAT: unable to set blocksize %u\n", | |
1146 | logical_sector_size); | |
1147 | goto out_fail; | |
1148 | } | |
1149 | bh = sb_bread(sb, 0); | |
1150 | if (bh == NULL) { | |
1151 | printk(KERN_ERR "FAT: unable to read boot sector" | |
1152 | " (logical sector size = %lu)\n", | |
1153 | sb->s_blocksize); | |
1154 | goto out_fail; | |
1155 | } | |
1156 | b = (struct fat_boot_sector *) bh->b_data; | |
1157 | } | |
1158 | ||
1159 | sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus; | |
1160 | sbi->cluster_bits = ffs(sbi->cluster_size) - 1; | |
1161 | sbi->fats = b->fats; | |
1162 | sbi->fat_bits = 0; /* Don't know yet */ | |
1163 | sbi->fat_start = le16_to_cpu(b->reserved); | |
1164 | sbi->fat_length = le16_to_cpu(b->fat_length); | |
1165 | sbi->root_cluster = 0; | |
1166 | sbi->free_clusters = -1; /* Don't know yet */ | |
1167 | sbi->prev_free = FAT_START_ENT; | |
1168 | ||
1169 | if (!sbi->fat_length && b->fat32_length) { | |
1170 | struct fat_boot_fsinfo *fsinfo; | |
1171 | struct buffer_head *fsinfo_bh; | |
1172 | ||
1173 | /* Must be FAT32 */ | |
1174 | sbi->fat_bits = 32; | |
1175 | sbi->fat_length = le32_to_cpu(b->fat32_length); | |
1176 | sbi->root_cluster = le32_to_cpu(b->root_cluster); | |
1177 | ||
1178 | sb->s_maxbytes = 0xffffffff; | |
1179 | ||
1180 | /* MC - if info_sector is 0, don't multiply by 0 */ | |
1181 | sbi->fsinfo_sector = le16_to_cpu(b->info_sector); | |
1182 | if (sbi->fsinfo_sector == 0) | |
1183 | sbi->fsinfo_sector = 1; | |
1184 | ||
1185 | fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector); | |
1186 | if (fsinfo_bh == NULL) { | |
1187 | printk(KERN_ERR "FAT: bread failed, FSINFO block" | |
1188 | " (sector = %lu)\n", sbi->fsinfo_sector); | |
1189 | brelse(bh); | |
1190 | goto out_fail; | |
1191 | } | |
1192 | ||
1193 | fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data; | |
1194 | if (!IS_FSINFO(fsinfo)) { | |
1195 | printk(KERN_WARNING | |
1196 | "FAT: Did not find valid FSINFO signature.\n" | |
1197 | " Found signature1 0x%08x signature2 0x%08x" | |
1198 | " (sector = %lu)\n", | |
1199 | le32_to_cpu(fsinfo->signature1), | |
1200 | le32_to_cpu(fsinfo->signature2), | |
1201 | sbi->fsinfo_sector); | |
1202 | } else { | |
1203 | sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters); | |
1204 | sbi->prev_free = le32_to_cpu(fsinfo->next_cluster); | |
1205 | } | |
1206 | ||
1207 | brelse(fsinfo_bh); | |
1208 | } | |
1209 | ||
1210 | sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry); | |
1211 | sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1; | |
1212 | ||
1213 | sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length; | |
1214 | sbi->dir_entries = | |
1215 | le16_to_cpu(get_unaligned((__le16 *)&b->dir_entries)); | |
1216 | if (sbi->dir_entries & (sbi->dir_per_block - 1)) { | |
1217 | if (!silent) | |
1218 | printk(KERN_ERR "FAT: bogus directroy-entries per block" | |
1219 | " (%u)\n", sbi->dir_entries); | |
1220 | brelse(bh); | |
1221 | goto out_invalid; | |
1222 | } | |
1223 | ||
1224 | rootdir_sectors = sbi->dir_entries | |
1225 | * sizeof(struct msdos_dir_entry) / sb->s_blocksize; | |
1226 | sbi->data_start = sbi->dir_start + rootdir_sectors; | |
1227 | total_sectors = le16_to_cpu(get_unaligned((__le16 *)&b->sectors)); | |
1228 | if (total_sectors == 0) | |
1229 | total_sectors = le32_to_cpu(b->total_sect); | |
1230 | ||
1231 | total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus; | |
1232 | ||
1233 | if (sbi->fat_bits != 32) | |
1234 | sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12; | |
1235 | ||
1236 | /* check that FAT table does not overflow */ | |
1237 | fat_clusters = sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits; | |
1238 | total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT); | |
1239 | if (total_clusters > MAX_FAT(sb)) { | |
1240 | if (!silent) | |
1241 | printk(KERN_ERR "FAT: count of clusters too big (%u)\n", | |
1242 | total_clusters); | |
1243 | brelse(bh); | |
1244 | goto out_invalid; | |
1245 | } | |
1246 | ||
1247 | sbi->max_cluster = total_clusters + FAT_START_ENT; | |
1248 | /* check the free_clusters, it's not necessarily correct */ | |
1249 | if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters) | |
1250 | sbi->free_clusters = -1; | |
1251 | /* check the prev_free, it's not necessarily correct */ | |
1252 | sbi->prev_free %= sbi->max_cluster; | |
1253 | if (sbi->prev_free < FAT_START_ENT) | |
1254 | sbi->prev_free = FAT_START_ENT; | |
1255 | ||
1256 | brelse(bh); | |
1257 | ||
1258 | /* set up enough so that it can read an inode */ | |
1259 | fat_hash_init(sb); | |
1260 | fat_ent_access_init(sb); | |
1261 | ||
1262 | /* | |
1263 | * The low byte of FAT's first entry must have same value with | |
1264 | * media-field. But in real world, too many devices is | |
1265 | * writing wrong value. So, removed that validity check. | |
1266 | * | |
1267 | * if (FAT_FIRST_ENT(sb, media) != first) | |
1268 | */ | |
1269 | ||
1270 | error = -EINVAL; | |
1271 | sprintf(buf, "cp%d", sbi->options.codepage); | |
1272 | sbi->nls_disk = load_nls(buf); | |
1273 | if (!sbi->nls_disk) { | |
1274 | printk(KERN_ERR "FAT: codepage %s not found\n", buf); | |
1275 | goto out_fail; | |
1276 | } | |
1277 | ||
1278 | /* FIXME: utf8 is using iocharset for upper/lower conversion */ | |
1279 | if (sbi->options.isvfat) { | |
1280 | sbi->nls_io = load_nls(sbi->options.iocharset); | |
1281 | if (!sbi->nls_io) { | |
1282 | printk(KERN_ERR "FAT: IO charset %s not found\n", | |
1283 | sbi->options.iocharset); | |
1284 | goto out_fail; | |
1285 | } | |
1286 | } | |
1287 | ||
1288 | error = -ENOMEM; | |
1289 | root_inode = new_inode(sb); | |
1290 | if (!root_inode) | |
1291 | goto out_fail; | |
1292 | root_inode->i_ino = MSDOS_ROOT_INO; | |
1293 | root_inode->i_version = 1; | |
1294 | error = fat_read_root(root_inode); | |
1295 | if (error < 0) | |
1296 | goto out_fail; | |
1297 | error = -ENOMEM; | |
1298 | insert_inode_hash(root_inode); | |
1299 | sb->s_root = d_alloc_root(root_inode); | |
1300 | if (!sb->s_root) { | |
1301 | printk(KERN_ERR "FAT: get root inode failed\n"); | |
1302 | goto out_fail; | |
1303 | } | |
1304 | ||
1305 | return 0; | |
1306 | ||
1307 | out_invalid: | |
1308 | error = -EINVAL; | |
1309 | if (!silent) | |
1310 | printk(KERN_INFO "VFS: Can't find a valid FAT filesystem" | |
1311 | " on dev %s.\n", sb->s_id); | |
1312 | ||
1313 | out_fail: | |
1314 | if (root_inode) | |
1315 | iput(root_inode); | |
1316 | if (sbi->nls_io) | |
1317 | unload_nls(sbi->nls_io); | |
1318 | if (sbi->nls_disk) | |
1319 | unload_nls(sbi->nls_disk); | |
1320 | if (sbi->options.iocharset != fat_default_iocharset) | |
1321 | kfree(sbi->options.iocharset); | |
1322 | sb->s_fs_info = NULL; | |
1323 | kfree(sbi); | |
1324 | return error; | |
1325 | } | |
1326 | ||
1327 | EXPORT_SYMBOL(fat_fill_super); | |
1328 | ||
1329 | int __init fat_cache_init(void); | |
1330 | void __exit fat_cache_destroy(void); | |
1331 | ||
1332 | static int __init init_fat_fs(void) | |
1333 | { | |
1334 | int ret; | |
1335 | ||
1336 | ret = fat_cache_init(); | |
1337 | if (ret < 0) | |
1338 | return ret; | |
1339 | return fat_init_inodecache(); | |
1340 | } | |
1341 | ||
1342 | static void __exit exit_fat_fs(void) | |
1343 | { | |
1344 | fat_cache_destroy(); | |
1345 | fat_destroy_inodecache(); | |
1346 | } | |
1347 | ||
1348 | module_init(init_fat_fs) | |
1349 | module_exit(exit_fat_fs) | |
1350 | ||
1351 | MODULE_LICENSE("GPL"); |