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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 | |
6e5b93ee ML |
117 | static int fat_ioctl_get_volume_id(struct inode *inode, u32 __user *user_attr) |
118 | { | |
119 | struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); | |
120 | return put_user(sbi->vol_id, user_attr); | |
121 | } | |
122 | ||
7845bc3e | 123 | long fat_generic_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) |
1da177e4 | 124 | { |
496ad9aa | 125 | struct inode *inode = file_inode(filp); |
1da177e4 | 126 | u32 __user *user_attr = (u32 __user *)arg; |
1da177e4 | 127 | |
1da177e4 LT |
128 | switch (cmd) { |
129 | case FAT_IOCTL_GET_ATTRIBUTES: | |
21bea495 | 130 | return fat_ioctl_get_attributes(inode, user_attr); |
1da177e4 | 131 | case FAT_IOCTL_SET_ATTRIBUTES: |
21bea495 | 132 | return fat_ioctl_set_attributes(filp, user_attr); |
6e5b93ee ML |
133 | case FAT_IOCTL_GET_VOLUME_ID: |
134 | return fat_ioctl_get_volume_id(inode, user_attr); | |
1da177e4 LT |
135 | default: |
136 | return -ENOTTY; /* Inappropriate ioctl for device */ | |
137 | } | |
138 | } | |
139 | ||
7845bc3e AB |
140 | #ifdef CONFIG_COMPAT |
141 | static long fat_generic_compat_ioctl(struct file *filp, unsigned int cmd, | |
142 | unsigned long arg) | |
143 | ||
144 | { | |
145 | return fat_generic_ioctl(filp, cmd, (unsigned long)compat_ptr(arg)); | |
146 | } | |
147 | #endif | |
148 | ||
ae78bf9c CM |
149 | static int fat_file_release(struct inode *inode, struct file *filp) |
150 | { | |
151 | if ((filp->f_mode & FMODE_WRITE) && | |
152 | MSDOS_SB(inode->i_sb)->options.flush) { | |
153 | fat_flush_inodes(inode->i_sb, inode, NULL); | |
8aa7e847 | 154 | congestion_wait(BLK_RW_ASYNC, HZ/10); |
ae78bf9c CM |
155 | } |
156 | return 0; | |
157 | } | |
158 | ||
02c24a82 | 159 | int fat_file_fsync(struct file *filp, loff_t start, loff_t end, int datasync) |
b522412a | 160 | { |
7ea80859 | 161 | struct inode *inode = filp->f_mapping->host; |
b522412a AV |
162 | int res, err; |
163 | ||
02c24a82 | 164 | res = generic_file_fsync(filp, start, end, datasync); |
b522412a AV |
165 | err = sync_mapping_buffers(MSDOS_SB(inode->i_sb)->fat_inode->i_mapping); |
166 | ||
167 | return res ? res : err; | |
168 | } | |
169 | ||
170 | ||
4b6f5d20 | 171 | const struct file_operations fat_file_operations = { |
1da177e4 | 172 | .llseek = generic_file_llseek, |
aad4f8bb | 173 | .read = new_sync_read, |
8174202b | 174 | .write = new_sync_write, |
aad4f8bb | 175 | .read_iter = generic_file_read_iter, |
8174202b | 176 | .write_iter = generic_file_write_iter, |
1da177e4 | 177 | .mmap = generic_file_mmap, |
ae78bf9c | 178 | .release = fat_file_release, |
7845bc3e AB |
179 | .unlocked_ioctl = fat_generic_ioctl, |
180 | #ifdef CONFIG_COMPAT | |
181 | .compat_ioctl = fat_generic_compat_ioctl, | |
182 | #endif | |
b522412a | 183 | .fsync = fat_file_fsync, |
5ffc4ef4 | 184 | .splice_read = generic_file_splice_read, |
1da177e4 LT |
185 | }; |
186 | ||
05eb0b51 OH |
187 | static int fat_cont_expand(struct inode *inode, loff_t size) |
188 | { | |
189 | struct address_space *mapping = inode->i_mapping; | |
190 | loff_t start = inode->i_size, count = size - inode->i_size; | |
191 | int err; | |
192 | ||
193 | err = generic_cont_expand_simple(inode, size); | |
194 | if (err) | |
195 | goto out; | |
196 | ||
197 | inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC; | |
198 | mark_inode_dirty(inode); | |
2f3d675b JK |
199 | if (IS_SYNC(inode)) { |
200 | int err2; | |
201 | ||
202 | /* | |
203 | * Opencode syncing since we don't have a file open to use | |
204 | * standard fsync path. | |
205 | */ | |
206 | err = filemap_fdatawrite_range(mapping, start, | |
207 | start + count - 1); | |
208 | err2 = sync_mapping_buffers(mapping); | |
209 | if (!err) | |
210 | err = err2; | |
211 | err2 = write_inode_now(inode, 1); | |
212 | if (!err) | |
213 | err = err2; | |
214 | if (!err) { | |
215 | err = filemap_fdatawait_range(mapping, start, | |
216 | start + count - 1); | |
217 | } | |
218 | } | |
05eb0b51 OH |
219 | out: |
220 | return err; | |
221 | } | |
222 | ||
1da177e4 LT |
223 | /* Free all clusters after the skip'th cluster. */ |
224 | static int fat_free(struct inode *inode, int skip) | |
225 | { | |
226 | struct super_block *sb = inode->i_sb; | |
227 | int err, wait, free_start, i_start, i_logstart; | |
228 | ||
229 | if (MSDOS_I(inode)->i_start == 0) | |
230 | return 0; | |
231 | ||
3b641407 OH |
232 | fat_cache_inval_inode(inode); |
233 | ||
1da177e4 | 234 | wait = IS_DIRSYNC(inode); |
3b641407 OH |
235 | i_start = free_start = MSDOS_I(inode)->i_start; |
236 | i_logstart = MSDOS_I(inode)->i_logstart; | |
237 | ||
238 | /* First, we write the new file size. */ | |
239 | if (!skip) { | |
240 | MSDOS_I(inode)->i_start = 0; | |
241 | MSDOS_I(inode)->i_logstart = 0; | |
242 | } | |
243 | MSDOS_I(inode)->i_attrs |= ATTR_ARCH; | |
244 | inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC; | |
245 | if (wait) { | |
246 | err = fat_sync_inode(inode); | |
247 | if (err) { | |
248 | MSDOS_I(inode)->i_start = i_start; | |
249 | MSDOS_I(inode)->i_logstart = i_logstart; | |
250 | return err; | |
251 | } | |
252 | } else | |
253 | mark_inode_dirty(inode); | |
254 | ||
255 | /* Write a new EOF, and get the remaining cluster chain for freeing. */ | |
1da177e4 LT |
256 | if (skip) { |
257 | struct fat_entry fatent; | |
258 | int ret, fclus, dclus; | |
259 | ||
260 | ret = fat_get_cluster(inode, skip - 1, &fclus, &dclus); | |
261 | if (ret < 0) | |
262 | return ret; | |
263 | else if (ret == FAT_ENT_EOF) | |
264 | return 0; | |
265 | ||
266 | fatent_init(&fatent); | |
267 | ret = fat_ent_read(inode, &fatent, dclus); | |
268 | if (ret == FAT_ENT_EOF) { | |
269 | fatent_brelse(&fatent); | |
270 | return 0; | |
271 | } else if (ret == FAT_ENT_FREE) { | |
85c78591 | 272 | fat_fs_error(sb, |
1da177e4 | 273 | "%s: invalid cluster chain (i_pos %lld)", |
8e24eea7 | 274 | __func__, MSDOS_I(inode)->i_pos); |
1da177e4 LT |
275 | ret = -EIO; |
276 | } else if (ret > 0) { | |
277 | err = fat_ent_write(inode, &fatent, FAT_ENT_EOF, wait); | |
278 | if (err) | |
279 | ret = err; | |
280 | } | |
281 | fatent_brelse(&fatent); | |
282 | if (ret < 0) | |
283 | return ret; | |
284 | ||
285 | free_start = ret; | |
1da177e4 | 286 | } |
1da177e4 LT |
287 | inode->i_blocks = skip << (MSDOS_SB(sb)->cluster_bits - 9); |
288 | ||
289 | /* Freeing the remained cluster chain */ | |
290 | return fat_free_clusters(inode, free_start); | |
1da177e4 LT |
291 | } |
292 | ||
459f6ed3 | 293 | void fat_truncate_blocks(struct inode *inode, loff_t offset) |
1da177e4 | 294 | { |
9c20616c | 295 | struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); |
1da177e4 LT |
296 | const unsigned int cluster_size = sbi->cluster_size; |
297 | int nr_clusters; | |
298 | ||
299 | /* | |
300 | * This protects against truncating a file bigger than it was then | |
301 | * trying to write into the hole. | |
302 | */ | |
459f6ed3 | 303 | if (MSDOS_I(inode)->mmu_private > offset) |
304 | MSDOS_I(inode)->mmu_private = offset; | |
1da177e4 | 305 | |
459f6ed3 | 306 | nr_clusters = (offset + (cluster_size - 1)) >> sbi->cluster_bits; |
1da177e4 | 307 | |
1da177e4 | 308 | fat_free(inode, nr_clusters); |
ae78bf9c | 309 | fat_flush_inodes(inode->i_sb, inode, NULL); |
1da177e4 LT |
310 | } |
311 | ||
da63fc7c OH |
312 | int fat_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) |
313 | { | |
314 | struct inode *inode = dentry->d_inode; | |
315 | generic_fillattr(inode, stat); | |
316 | stat->blksize = MSDOS_SB(inode->i_sb)->cluster_size; | |
ea3983ac NJ |
317 | |
318 | if (MSDOS_SB(inode->i_sb)->options.nfs == FAT_NFS_NOSTALE_RO) { | |
319 | /* Use i_pos for ino. This is used as fileid of nfs. */ | |
320 | stat->ino = fat_i_pos_read(MSDOS_SB(inode->i_sb), inode); | |
321 | } | |
da63fc7c OH |
322 | return 0; |
323 | } | |
324 | EXPORT_SYMBOL_GPL(fat_getattr); | |
325 | ||
2d518f84 OH |
326 | static int fat_sanitize_mode(const struct msdos_sb_info *sbi, |
327 | struct inode *inode, umode_t *mode_ptr) | |
1278fdd3 | 328 | { |
dacd0e7b | 329 | umode_t mask, perm; |
1278fdd3 | 330 | |
2d518f84 OH |
331 | /* |
332 | * Note, the basic check is already done by a caller of | |
9c0aa1b8 | 333 | * (attr->ia_mode & ~FAT_VALID_MODE) |
2d518f84 OH |
334 | */ |
335 | ||
336 | if (S_ISREG(inode->i_mode)) | |
1278fdd3 OH |
337 | mask = sbi->options.fs_fmask; |
338 | else | |
339 | mask = sbi->options.fs_dmask; | |
340 | ||
2d518f84 OH |
341 | perm = *mode_ptr & ~(S_IFMT | mask); |
342 | ||
1278fdd3 OH |
343 | /* |
344 | * Of the r and x bits, all (subject to umask) must be present. Of the | |
345 | * w bits, either all (subject to umask) or none must be present. | |
dfc209c0 OH |
346 | * |
347 | * If fat_mode_can_hold_ro(inode) is false, can't change w bits. | |
1278fdd3 | 348 | */ |
2d518f84 | 349 | if ((perm & (S_IRUGO | S_IXUGO)) != (inode->i_mode & (S_IRUGO|S_IXUGO))) |
1278fdd3 | 350 | return -EPERM; |
dfc209c0 OH |
351 | if (fat_mode_can_hold_ro(inode)) { |
352 | if ((perm & S_IWUGO) && ((perm & S_IWUGO) != (S_IWUGO & ~mask))) | |
353 | return -EPERM; | |
354 | } else { | |
355 | if ((perm & S_IWUGO) != (S_IWUGO & ~mask)) | |
356 | return -EPERM; | |
357 | } | |
1278fdd3 | 358 | |
2d518f84 OH |
359 | *mode_ptr &= S_IFMT | perm; |
360 | ||
1278fdd3 OH |
361 | return 0; |
362 | } | |
363 | ||
1ae43f82 OH |
364 | static int fat_allow_set_time(struct msdos_sb_info *sbi, struct inode *inode) |
365 | { | |
dacd0e7b | 366 | umode_t allow_utime = sbi->options.allow_utime; |
1ae43f82 | 367 | |
170782eb | 368 | if (!uid_eq(current_fsuid(), inode->i_uid)) { |
1ae43f82 OH |
369 | if (in_group_p(inode->i_gid)) |
370 | allow_utime >>= 3; | |
371 | if (allow_utime & MAY_WRITE) | |
372 | return 1; | |
373 | } | |
374 | ||
375 | /* use a default check */ | |
376 | return 0; | |
377 | } | |
378 | ||
17263849 | 379 | #define TIMES_SET_FLAGS (ATTR_MTIME_SET | ATTR_ATIME_SET | ATTR_TIMES_SET) |
9c0aa1b8 OH |
380 | /* valid file mode bits */ |
381 | #define FAT_VALID_MODE (S_IFREG | S_IFDIR | S_IRWXUGO) | |
17263849 | 382 | |
1278fdd3 OH |
383 | int fat_setattr(struct dentry *dentry, struct iattr *attr) |
384 | { | |
385 | struct msdos_sb_info *sbi = MSDOS_SB(dentry->d_sb); | |
386 | struct inode *inode = dentry->d_inode; | |
1ae43f82 | 387 | unsigned int ia_valid; |
dfc209c0 | 388 | int error; |
1278fdd3 | 389 | |
1ae43f82 OH |
390 | /* Check for setting the inode time. */ |
391 | ia_valid = attr->ia_valid; | |
17263849 | 392 | if (ia_valid & TIMES_SET_FLAGS) { |
1ae43f82 | 393 | if (fat_allow_set_time(sbi, inode)) |
17263849 | 394 | attr->ia_valid &= ~TIMES_SET_FLAGS; |
1ae43f82 OH |
395 | } |
396 | ||
1278fdd3 | 397 | error = inode_change_ok(inode, attr); |
1ae43f82 | 398 | attr->ia_valid = ia_valid; |
1278fdd3 OH |
399 | if (error) { |
400 | if (sbi->options.quiet) | |
401 | error = 0; | |
402 | goto out; | |
403 | } | |
2d518f84 | 404 | |
db78b877 CH |
405 | /* |
406 | * Expand the file. Since inode_setattr() updates ->i_size | |
407 | * before calling the ->truncate(), but FAT needs to fill the | |
408 | * hole before it. XXX: this is no longer true with new truncate | |
409 | * sequence. | |
410 | */ | |
411 | if (attr->ia_valid & ATTR_SIZE) { | |
562c72aa CH |
412 | inode_dio_wait(inode); |
413 | ||
db78b877 CH |
414 | if (attr->ia_size > inode->i_size) { |
415 | error = fat_cont_expand(inode, attr->ia_size); | |
416 | if (error || attr->ia_valid == ATTR_SIZE) | |
417 | goto out; | |
418 | attr->ia_valid &= ~ATTR_SIZE; | |
419 | } | |
420 | } | |
421 | ||
1278fdd3 | 422 | if (((attr->ia_valid & ATTR_UID) && |
170782eb | 423 | (!uid_eq(attr->ia_uid, sbi->options.fs_uid))) || |
1278fdd3 | 424 | ((attr->ia_valid & ATTR_GID) && |
170782eb | 425 | (!gid_eq(attr->ia_gid, sbi->options.fs_gid))) || |
e97e8de3 | 426 | ((attr->ia_valid & ATTR_MODE) && |
9c0aa1b8 | 427 | (attr->ia_mode & ~FAT_VALID_MODE))) |
1278fdd3 OH |
428 | error = -EPERM; |
429 | ||
430 | if (error) { | |
431 | if (sbi->options.quiet) | |
432 | error = 0; | |
433 | goto out; | |
434 | } | |
435 | ||
2d518f84 OH |
436 | /* |
437 | * We don't return -EPERM here. Yes, strange, but this is too | |
438 | * old behavior. | |
439 | */ | |
440 | if (attr->ia_valid & ATTR_MODE) { | |
441 | if (fat_sanitize_mode(sbi, inode, &attr->ia_mode) < 0) | |
442 | attr->ia_valid &= ~ATTR_MODE; | |
443 | } | |
1278fdd3 | 444 | |
459f6ed3 | 445 | if (attr->ia_valid & ATTR_SIZE) { |
c0ef0cc9 NJ |
446 | error = fat_block_truncate_page(inode, attr->ia_size); |
447 | if (error) | |
448 | goto out; | |
58268691 | 449 | down_write(&MSDOS_I(inode)->truncate_lock); |
2c27c65e CH |
450 | truncate_setsize(inode, attr->ia_size); |
451 | fat_truncate_blocks(inode, attr->ia_size); | |
58268691 | 452 | up_write(&MSDOS_I(inode)->truncate_lock); |
459f6ed3 | 453 | } |
454 | ||
6a1a90ad | 455 | setattr_copy(inode, attr); |
459f6ed3 | 456 | mark_inode_dirty(inode); |
1278fdd3 | 457 | out: |
1278fdd3 OH |
458 | return error; |
459 | } | |
460 | EXPORT_SYMBOL_GPL(fat_setattr); | |
461 | ||
754661f1 | 462 | const struct inode_operations fat_file_inode_operations = { |
1278fdd3 | 463 | .setattr = fat_setattr, |
da63fc7c | 464 | .getattr = fat_getattr, |
1da177e4 | 465 | }; |