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Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/fs/fat/file.c | |
3 | * | |
4 | * Written 1992,1993 by Werner Almesberger | |
5 | * | |
6 | * regular file handling primitives for fat-based filesystems | |
7 | */ | |
8 | ||
16f7e0fe | 9 | #include <linux/capability.h> |
1da177e4 | 10 | #include <linux/module.h> |
7845bc3e | 11 | #include <linux/compat.h> |
42a74f20 | 12 | #include <linux/mount.h> |
1da177e4 | 13 | #include <linux/time.h> |
1da177e4 | 14 | #include <linux/buffer_head.h> |
05eb0b51 | 15 | #include <linux/writeback.h> |
3fcfab16 | 16 | #include <linux/backing-dev.h> |
ae78bf9c | 17 | #include <linux/blkdev.h> |
b1da47e2 MS |
18 | #include <linux/fsnotify.h> |
19 | #include <linux/security.h> | |
9e975dae | 20 | #include "fat.h" |
1da177e4 | 21 | |
21bea495 CH |
22 | static int fat_ioctl_get_attributes(struct inode *inode, u32 __user *user_attr) |
23 | { | |
24 | u32 attr; | |
25 | ||
26 | mutex_lock(&inode->i_mutex); | |
27 | attr = fat_make_attrs(inode); | |
28 | mutex_unlock(&inode->i_mutex); | |
29 | ||
30 | return put_user(attr, user_attr); | |
31 | } | |
32 | ||
33 | static int fat_ioctl_set_attributes(struct file *file, u32 __user *user_attr) | |
1da177e4 | 34 | { |
496ad9aa | 35 | struct inode *inode = file_inode(file); |
1da177e4 | 36 | struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); |
21bea495 CH |
37 | int is_dir = S_ISDIR(inode->i_mode); |
38 | u32 attr, oldattr; | |
39 | struct iattr ia; | |
40 | int err; | |
1da177e4 | 41 | |
21bea495 CH |
42 | err = get_user(attr, user_attr); |
43 | if (err) | |
44 | goto out; | |
1da177e4 | 45 | |
a561be71 | 46 | err = mnt_want_write_file(file); |
21bea495 | 47 | if (err) |
e24f17da JK |
48 | goto out; |
49 | mutex_lock(&inode->i_mutex); | |
21bea495 CH |
50 | |
51 | /* | |
52 | * ATTR_VOLUME and ATTR_DIR cannot be changed; this also | |
53 | * prevents the user from turning us into a VFAT | |
54 | * longname entry. Also, we obviously can't set | |
55 | * any of the NTFS attributes in the high 24 bits. | |
56 | */ | |
57 | attr &= 0xff & ~(ATTR_VOLUME | ATTR_DIR); | |
58 | /* Merge in ATTR_VOLUME and ATTR_DIR */ | |
59 | attr |= (MSDOS_I(inode)->i_attrs & ATTR_VOLUME) | | |
60 | (is_dir ? ATTR_DIR : 0); | |
61 | oldattr = fat_make_attrs(inode); | |
62 | ||
63 | /* Equivalent to a chmod() */ | |
64 | ia.ia_valid = ATTR_MODE | ATTR_CTIME; | |
65 | ia.ia_ctime = current_fs_time(inode->i_sb); | |
66 | if (is_dir) | |
67 | ia.ia_mode = fat_make_mode(sbi, attr, S_IRWXUGO); | |
68 | else { | |
69 | ia.ia_mode = fat_make_mode(sbi, attr, | |
70 | S_IRUGO | S_IWUGO | (inode->i_mode & S_IXUGO)); | |
71 | } | |
1da177e4 | 72 | |
21bea495 CH |
73 | /* The root directory has no attributes */ |
74 | if (inode->i_ino == MSDOS_ROOT_INO && attr != ATTR_DIR) { | |
75 | err = -EINVAL; | |
e24f17da | 76 | goto out_unlock_inode; |
1da177e4 | 77 | } |
1da177e4 | 78 | |
21bea495 CH |
79 | if (sbi->options.sys_immutable && |
80 | ((attr | oldattr) & ATTR_SYS) && | |
81 | !capable(CAP_LINUX_IMMUTABLE)) { | |
82 | err = -EPERM; | |
e24f17da | 83 | goto out_unlock_inode; |
21bea495 | 84 | } |
1da177e4 | 85 | |
21bea495 CH |
86 | /* |
87 | * The security check is questionable... We single | |
88 | * out the RO attribute for checking by the security | |
89 | * module, just because it maps to a file mode. | |
90 | */ | |
91 | err = security_inode_setattr(file->f_path.dentry, &ia); | |
92 | if (err) | |
e24f17da | 93 | goto out_unlock_inode; |
1da177e4 | 94 | |
21bea495 CH |
95 | /* This MUST be done before doing anything irreversible... */ |
96 | err = fat_setattr(file->f_path.dentry, &ia); | |
97 | if (err) | |
e24f17da | 98 | goto out_unlock_inode; |
21bea495 CH |
99 | |
100 | fsnotify_change(file->f_path.dentry, ia.ia_valid); | |
101 | if (sbi->options.sys_immutable) { | |
102 | if (attr & ATTR_SYS) | |
103 | inode->i_flags |= S_IMMUTABLE; | |
104 | else | |
1adffbae | 105 | inode->i_flags &= ~S_IMMUTABLE; |
21bea495 | 106 | } |
1da177e4 | 107 | |
21bea495 CH |
108 | fat_save_attrs(inode, attr); |
109 | mark_inode_dirty(inode); | |
21bea495 CH |
110 | out_unlock_inode: |
111 | mutex_unlock(&inode->i_mutex); | |
e24f17da | 112 | mnt_drop_write_file(file); |
21bea495 CH |
113 | out: |
114 | return err; | |
115 | } | |
1da177e4 | 116 | |
7845bc3e | 117 | long fat_generic_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) |
1da177e4 | 118 | { |
496ad9aa | 119 | struct inode *inode = file_inode(filp); |
1da177e4 | 120 | u32 __user *user_attr = (u32 __user *)arg; |
1da177e4 | 121 | |
1da177e4 LT |
122 | switch (cmd) { |
123 | case FAT_IOCTL_GET_ATTRIBUTES: | |
21bea495 | 124 | return fat_ioctl_get_attributes(inode, user_attr); |
1da177e4 | 125 | case FAT_IOCTL_SET_ATTRIBUTES: |
21bea495 | 126 | return fat_ioctl_set_attributes(filp, user_attr); |
1da177e4 LT |
127 | default: |
128 | return -ENOTTY; /* Inappropriate ioctl for device */ | |
129 | } | |
130 | } | |
131 | ||
7845bc3e AB |
132 | #ifdef CONFIG_COMPAT |
133 | static long fat_generic_compat_ioctl(struct file *filp, unsigned int cmd, | |
134 | unsigned long arg) | |
135 | ||
136 | { | |
137 | return fat_generic_ioctl(filp, cmd, (unsigned long)compat_ptr(arg)); | |
138 | } | |
139 | #endif | |
140 | ||
ae78bf9c CM |
141 | static int fat_file_release(struct inode *inode, struct file *filp) |
142 | { | |
143 | if ((filp->f_mode & FMODE_WRITE) && | |
144 | MSDOS_SB(inode->i_sb)->options.flush) { | |
145 | fat_flush_inodes(inode->i_sb, inode, NULL); | |
8aa7e847 | 146 | congestion_wait(BLK_RW_ASYNC, HZ/10); |
ae78bf9c CM |
147 | } |
148 | return 0; | |
149 | } | |
150 | ||
02c24a82 | 151 | int fat_file_fsync(struct file *filp, loff_t start, loff_t end, int datasync) |
b522412a | 152 | { |
7ea80859 | 153 | struct inode *inode = filp->f_mapping->host; |
b522412a AV |
154 | int res, err; |
155 | ||
02c24a82 | 156 | res = generic_file_fsync(filp, start, end, datasync); |
b522412a AV |
157 | err = sync_mapping_buffers(MSDOS_SB(inode->i_sb)->fat_inode->i_mapping); |
158 | ||
159 | return res ? res : err; | |
160 | } | |
161 | ||
162 | ||
4b6f5d20 | 163 | const struct file_operations fat_file_operations = { |
1da177e4 LT |
164 | .llseek = generic_file_llseek, |
165 | .read = do_sync_read, | |
166 | .write = do_sync_write, | |
1da177e4 | 167 | .aio_read = generic_file_aio_read, |
ef402268 | 168 | .aio_write = generic_file_aio_write, |
1da177e4 | 169 | .mmap = generic_file_mmap, |
ae78bf9c | 170 | .release = fat_file_release, |
7845bc3e AB |
171 | .unlocked_ioctl = fat_generic_ioctl, |
172 | #ifdef CONFIG_COMPAT | |
173 | .compat_ioctl = fat_generic_compat_ioctl, | |
174 | #endif | |
b522412a | 175 | .fsync = fat_file_fsync, |
5ffc4ef4 | 176 | .splice_read = generic_file_splice_read, |
1da177e4 LT |
177 | }; |
178 | ||
05eb0b51 OH |
179 | static int fat_cont_expand(struct inode *inode, loff_t size) |
180 | { | |
181 | struct address_space *mapping = inode->i_mapping; | |
182 | loff_t start = inode->i_size, count = size - inode->i_size; | |
183 | int err; | |
184 | ||
185 | err = generic_cont_expand_simple(inode, size); | |
186 | if (err) | |
187 | goto out; | |
188 | ||
189 | inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC; | |
190 | mark_inode_dirty(inode); | |
2f3d675b JK |
191 | if (IS_SYNC(inode)) { |
192 | int err2; | |
193 | ||
194 | /* | |
195 | * Opencode syncing since we don't have a file open to use | |
196 | * standard fsync path. | |
197 | */ | |
198 | err = filemap_fdatawrite_range(mapping, start, | |
199 | start + count - 1); | |
200 | err2 = sync_mapping_buffers(mapping); | |
201 | if (!err) | |
202 | err = err2; | |
203 | err2 = write_inode_now(inode, 1); | |
204 | if (!err) | |
205 | err = err2; | |
206 | if (!err) { | |
207 | err = filemap_fdatawait_range(mapping, start, | |
208 | start + count - 1); | |
209 | } | |
210 | } | |
05eb0b51 OH |
211 | out: |
212 | return err; | |
213 | } | |
214 | ||
1da177e4 LT |
215 | /* Free all clusters after the skip'th cluster. */ |
216 | static int fat_free(struct inode *inode, int skip) | |
217 | { | |
218 | struct super_block *sb = inode->i_sb; | |
219 | int err, wait, free_start, i_start, i_logstart; | |
220 | ||
221 | if (MSDOS_I(inode)->i_start == 0) | |
222 | return 0; | |
223 | ||
3b641407 OH |
224 | fat_cache_inval_inode(inode); |
225 | ||
1da177e4 | 226 | wait = IS_DIRSYNC(inode); |
3b641407 OH |
227 | i_start = free_start = MSDOS_I(inode)->i_start; |
228 | i_logstart = MSDOS_I(inode)->i_logstart; | |
229 | ||
230 | /* First, we write the new file size. */ | |
231 | if (!skip) { | |
232 | MSDOS_I(inode)->i_start = 0; | |
233 | MSDOS_I(inode)->i_logstart = 0; | |
234 | } | |
235 | MSDOS_I(inode)->i_attrs |= ATTR_ARCH; | |
236 | inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC; | |
237 | if (wait) { | |
238 | err = fat_sync_inode(inode); | |
239 | if (err) { | |
240 | MSDOS_I(inode)->i_start = i_start; | |
241 | MSDOS_I(inode)->i_logstart = i_logstart; | |
242 | return err; | |
243 | } | |
244 | } else | |
245 | mark_inode_dirty(inode); | |
246 | ||
247 | /* Write a new EOF, and get the remaining cluster chain for freeing. */ | |
1da177e4 LT |
248 | if (skip) { |
249 | struct fat_entry fatent; | |
250 | int ret, fclus, dclus; | |
251 | ||
252 | ret = fat_get_cluster(inode, skip - 1, &fclus, &dclus); | |
253 | if (ret < 0) | |
254 | return ret; | |
255 | else if (ret == FAT_ENT_EOF) | |
256 | return 0; | |
257 | ||
258 | fatent_init(&fatent); | |
259 | ret = fat_ent_read(inode, &fatent, dclus); | |
260 | if (ret == FAT_ENT_EOF) { | |
261 | fatent_brelse(&fatent); | |
262 | return 0; | |
263 | } else if (ret == FAT_ENT_FREE) { | |
85c78591 | 264 | fat_fs_error(sb, |
1da177e4 | 265 | "%s: invalid cluster chain (i_pos %lld)", |
8e24eea7 | 266 | __func__, MSDOS_I(inode)->i_pos); |
1da177e4 LT |
267 | ret = -EIO; |
268 | } else if (ret > 0) { | |
269 | err = fat_ent_write(inode, &fatent, FAT_ENT_EOF, wait); | |
270 | if (err) | |
271 | ret = err; | |
272 | } | |
273 | fatent_brelse(&fatent); | |
274 | if (ret < 0) | |
275 | return ret; | |
276 | ||
277 | free_start = ret; | |
1da177e4 | 278 | } |
1da177e4 LT |
279 | inode->i_blocks = skip << (MSDOS_SB(sb)->cluster_bits - 9); |
280 | ||
281 | /* Freeing the remained cluster chain */ | |
282 | return fat_free_clusters(inode, free_start); | |
1da177e4 LT |
283 | } |
284 | ||
459f6ed3 | 285 | void fat_truncate_blocks(struct inode *inode, loff_t offset) |
1da177e4 | 286 | { |
9c20616c | 287 | struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); |
1da177e4 LT |
288 | const unsigned int cluster_size = sbi->cluster_size; |
289 | int nr_clusters; | |
290 | ||
291 | /* | |
292 | * This protects against truncating a file bigger than it was then | |
293 | * trying to write into the hole. | |
294 | */ | |
459f6ed3 | 295 | if (MSDOS_I(inode)->mmu_private > offset) |
296 | MSDOS_I(inode)->mmu_private = offset; | |
1da177e4 | 297 | |
459f6ed3 | 298 | nr_clusters = (offset + (cluster_size - 1)) >> sbi->cluster_bits; |
1da177e4 | 299 | |
1da177e4 | 300 | fat_free(inode, nr_clusters); |
ae78bf9c | 301 | fat_flush_inodes(inode->i_sb, inode, NULL); |
1da177e4 LT |
302 | } |
303 | ||
da63fc7c OH |
304 | int fat_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) |
305 | { | |
306 | struct inode *inode = dentry->d_inode; | |
307 | generic_fillattr(inode, stat); | |
308 | stat->blksize = MSDOS_SB(inode->i_sb)->cluster_size; | |
ea3983ac NJ |
309 | |
310 | if (MSDOS_SB(inode->i_sb)->options.nfs == FAT_NFS_NOSTALE_RO) { | |
311 | /* Use i_pos for ino. This is used as fileid of nfs. */ | |
312 | stat->ino = fat_i_pos_read(MSDOS_SB(inode->i_sb), inode); | |
313 | } | |
da63fc7c OH |
314 | return 0; |
315 | } | |
316 | EXPORT_SYMBOL_GPL(fat_getattr); | |
317 | ||
2d518f84 OH |
318 | static int fat_sanitize_mode(const struct msdos_sb_info *sbi, |
319 | struct inode *inode, umode_t *mode_ptr) | |
1278fdd3 | 320 | { |
dacd0e7b | 321 | umode_t mask, perm; |
1278fdd3 | 322 | |
2d518f84 OH |
323 | /* |
324 | * Note, the basic check is already done by a caller of | |
9c0aa1b8 | 325 | * (attr->ia_mode & ~FAT_VALID_MODE) |
2d518f84 OH |
326 | */ |
327 | ||
328 | if (S_ISREG(inode->i_mode)) | |
1278fdd3 OH |
329 | mask = sbi->options.fs_fmask; |
330 | else | |
331 | mask = sbi->options.fs_dmask; | |
332 | ||
2d518f84 OH |
333 | perm = *mode_ptr & ~(S_IFMT | mask); |
334 | ||
1278fdd3 OH |
335 | /* |
336 | * Of the r and x bits, all (subject to umask) must be present. Of the | |
337 | * w bits, either all (subject to umask) or none must be present. | |
dfc209c0 OH |
338 | * |
339 | * If fat_mode_can_hold_ro(inode) is false, can't change w bits. | |
1278fdd3 | 340 | */ |
2d518f84 | 341 | if ((perm & (S_IRUGO | S_IXUGO)) != (inode->i_mode & (S_IRUGO|S_IXUGO))) |
1278fdd3 | 342 | return -EPERM; |
dfc209c0 OH |
343 | if (fat_mode_can_hold_ro(inode)) { |
344 | if ((perm & S_IWUGO) && ((perm & S_IWUGO) != (S_IWUGO & ~mask))) | |
345 | return -EPERM; | |
346 | } else { | |
347 | if ((perm & S_IWUGO) != (S_IWUGO & ~mask)) | |
348 | return -EPERM; | |
349 | } | |
1278fdd3 | 350 | |
2d518f84 OH |
351 | *mode_ptr &= S_IFMT | perm; |
352 | ||
1278fdd3 OH |
353 | return 0; |
354 | } | |
355 | ||
1ae43f82 OH |
356 | static int fat_allow_set_time(struct msdos_sb_info *sbi, struct inode *inode) |
357 | { | |
dacd0e7b | 358 | umode_t allow_utime = sbi->options.allow_utime; |
1ae43f82 | 359 | |
170782eb | 360 | if (!uid_eq(current_fsuid(), inode->i_uid)) { |
1ae43f82 OH |
361 | if (in_group_p(inode->i_gid)) |
362 | allow_utime >>= 3; | |
363 | if (allow_utime & MAY_WRITE) | |
364 | return 1; | |
365 | } | |
366 | ||
367 | /* use a default check */ | |
368 | return 0; | |
369 | } | |
370 | ||
17263849 | 371 | #define TIMES_SET_FLAGS (ATTR_MTIME_SET | ATTR_ATIME_SET | ATTR_TIMES_SET) |
9c0aa1b8 OH |
372 | /* valid file mode bits */ |
373 | #define FAT_VALID_MODE (S_IFREG | S_IFDIR | S_IRWXUGO) | |
17263849 | 374 | |
1278fdd3 OH |
375 | int fat_setattr(struct dentry *dentry, struct iattr *attr) |
376 | { | |
377 | struct msdos_sb_info *sbi = MSDOS_SB(dentry->d_sb); | |
378 | struct inode *inode = dentry->d_inode; | |
1ae43f82 | 379 | unsigned int ia_valid; |
dfc209c0 | 380 | int error; |
1278fdd3 | 381 | |
1ae43f82 OH |
382 | /* Check for setting the inode time. */ |
383 | ia_valid = attr->ia_valid; | |
17263849 | 384 | if (ia_valid & TIMES_SET_FLAGS) { |
1ae43f82 | 385 | if (fat_allow_set_time(sbi, inode)) |
17263849 | 386 | attr->ia_valid &= ~TIMES_SET_FLAGS; |
1ae43f82 OH |
387 | } |
388 | ||
1278fdd3 | 389 | error = inode_change_ok(inode, attr); |
1ae43f82 | 390 | attr->ia_valid = ia_valid; |
1278fdd3 OH |
391 | if (error) { |
392 | if (sbi->options.quiet) | |
393 | error = 0; | |
394 | goto out; | |
395 | } | |
2d518f84 | 396 | |
db78b877 CH |
397 | /* |
398 | * Expand the file. Since inode_setattr() updates ->i_size | |
399 | * before calling the ->truncate(), but FAT needs to fill the | |
400 | * hole before it. XXX: this is no longer true with new truncate | |
401 | * sequence. | |
402 | */ | |
403 | if (attr->ia_valid & ATTR_SIZE) { | |
562c72aa CH |
404 | inode_dio_wait(inode); |
405 | ||
db78b877 CH |
406 | if (attr->ia_size > inode->i_size) { |
407 | error = fat_cont_expand(inode, attr->ia_size); | |
408 | if (error || attr->ia_valid == ATTR_SIZE) | |
409 | goto out; | |
410 | attr->ia_valid &= ~ATTR_SIZE; | |
411 | } | |
412 | } | |
413 | ||
1278fdd3 | 414 | if (((attr->ia_valid & ATTR_UID) && |
170782eb | 415 | (!uid_eq(attr->ia_uid, sbi->options.fs_uid))) || |
1278fdd3 | 416 | ((attr->ia_valid & ATTR_GID) && |
170782eb | 417 | (!gid_eq(attr->ia_gid, sbi->options.fs_gid))) || |
e97e8de3 | 418 | ((attr->ia_valid & ATTR_MODE) && |
9c0aa1b8 | 419 | (attr->ia_mode & ~FAT_VALID_MODE))) |
1278fdd3 OH |
420 | error = -EPERM; |
421 | ||
422 | if (error) { | |
423 | if (sbi->options.quiet) | |
424 | error = 0; | |
425 | goto out; | |
426 | } | |
427 | ||
2d518f84 OH |
428 | /* |
429 | * We don't return -EPERM here. Yes, strange, but this is too | |
430 | * old behavior. | |
431 | */ | |
432 | if (attr->ia_valid & ATTR_MODE) { | |
433 | if (fat_sanitize_mode(sbi, inode, &attr->ia_mode) < 0) | |
434 | attr->ia_valid &= ~ATTR_MODE; | |
435 | } | |
1278fdd3 | 436 | |
459f6ed3 | 437 | if (attr->ia_valid & ATTR_SIZE) { |
58268691 | 438 | down_write(&MSDOS_I(inode)->truncate_lock); |
2c27c65e CH |
439 | truncate_setsize(inode, attr->ia_size); |
440 | fat_truncate_blocks(inode, attr->ia_size); | |
58268691 | 441 | up_write(&MSDOS_I(inode)->truncate_lock); |
459f6ed3 | 442 | } |
443 | ||
6a1a90ad | 444 | setattr_copy(inode, attr); |
459f6ed3 | 445 | mark_inode_dirty(inode); |
1278fdd3 | 446 | out: |
1278fdd3 OH |
447 | return error; |
448 | } | |
449 | EXPORT_SYMBOL_GPL(fat_setattr); | |
450 | ||
754661f1 | 451 | const struct inode_operations fat_file_inode_operations = { |
1278fdd3 | 452 | .setattr = fat_setattr, |
da63fc7c | 453 | .getattr = fat_getattr, |
1da177e4 | 454 | }; |