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 LT |
10 | #include <linux/module.h> |
11 | #include <linux/time.h> | |
12 | #include <linux/msdos_fs.h> | |
13 | #include <linux/smp_lock.h> | |
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> |
1da177e4 | 18 | |
1da177e4 LT |
19 | int fat_generic_ioctl(struct inode *inode, struct file *filp, |
20 | unsigned int cmd, unsigned long arg) | |
21 | { | |
22 | struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); | |
23 | u32 __user *user_attr = (u32 __user *)arg; | |
24 | ||
25 | switch (cmd) { | |
26 | case FAT_IOCTL_GET_ATTRIBUTES: | |
27 | { | |
28 | u32 attr; | |
29 | ||
30 | if (inode->i_ino == MSDOS_ROOT_INO) | |
31 | attr = ATTR_DIR; | |
32 | else | |
33 | attr = fat_attr(inode); | |
34 | ||
35 | return put_user(attr, user_attr); | |
36 | } | |
37 | case FAT_IOCTL_SET_ATTRIBUTES: | |
38 | { | |
39 | u32 attr, oldattr; | |
40 | int err, is_dir = S_ISDIR(inode->i_mode); | |
41 | struct iattr ia; | |
42 | ||
43 | err = get_user(attr, user_attr); | |
44 | if (err) | |
45 | return err; | |
46 | ||
1b1dcc1b | 47 | mutex_lock(&inode->i_mutex); |
1da177e4 LT |
48 | |
49 | if (IS_RDONLY(inode)) { | |
50 | err = -EROFS; | |
51 | goto up; | |
52 | } | |
53 | ||
54 | /* | |
55 | * ATTR_VOLUME and ATTR_DIR cannot be changed; this also | |
56 | * prevents the user from turning us into a VFAT | |
57 | * longname entry. Also, we obviously can't set | |
58 | * any of the NTFS attributes in the high 24 bits. | |
59 | */ | |
60 | attr &= 0xff & ~(ATTR_VOLUME | ATTR_DIR); | |
61 | /* Merge in ATTR_VOLUME and ATTR_DIR */ | |
62 | attr |= (MSDOS_I(inode)->i_attrs & ATTR_VOLUME) | | |
63 | (is_dir ? ATTR_DIR : 0); | |
64 | oldattr = fat_attr(inode); | |
65 | ||
66 | /* Equivalent to a chmod() */ | |
67 | ia.ia_valid = ATTR_MODE | ATTR_CTIME; | |
68 | if (is_dir) { | |
69 | ia.ia_mode = MSDOS_MKMODE(attr, | |
70 | S_IRWXUGO & ~sbi->options.fs_dmask) | |
71 | | S_IFDIR; | |
72 | } else { | |
73 | ia.ia_mode = MSDOS_MKMODE(attr, | |
74 | (S_IRUGO | S_IWUGO | (inode->i_mode & S_IXUGO)) | |
75 | & ~sbi->options.fs_fmask) | |
76 | | S_IFREG; | |
77 | } | |
78 | ||
79 | /* The root directory has no attributes */ | |
80 | if (inode->i_ino == MSDOS_ROOT_INO && attr != ATTR_DIR) { | |
81 | err = -EINVAL; | |
82 | goto up; | |
83 | } | |
84 | ||
85 | if (sbi->options.sys_immutable) { | |
86 | if ((attr | oldattr) & ATTR_SYS) { | |
87 | if (!capable(CAP_LINUX_IMMUTABLE)) { | |
88 | err = -EPERM; | |
89 | goto up; | |
90 | } | |
91 | } | |
92 | } | |
93 | ||
94 | /* This MUST be done before doing anything irreversible... */ | |
dba32306 | 95 | err = notify_change(filp->f_path.dentry, &ia); |
1da177e4 LT |
96 | if (err) |
97 | goto up; | |
98 | ||
99 | if (sbi->options.sys_immutable) { | |
100 | if (attr & ATTR_SYS) | |
101 | inode->i_flags |= S_IMMUTABLE; | |
102 | else | |
103 | inode->i_flags &= S_IMMUTABLE; | |
104 | } | |
105 | ||
106 | MSDOS_I(inode)->i_attrs = attr & ATTR_UNUSED; | |
107 | mark_inode_dirty(inode); | |
108 | up: | |
1b1dcc1b | 109 | mutex_unlock(&inode->i_mutex); |
1da177e4 LT |
110 | return err; |
111 | } | |
112 | default: | |
113 | return -ENOTTY; /* Inappropriate ioctl for device */ | |
114 | } | |
115 | } | |
116 | ||
ae78bf9c CM |
117 | static int fat_file_release(struct inode *inode, struct file *filp) |
118 | { | |
119 | if ((filp->f_mode & FMODE_WRITE) && | |
120 | MSDOS_SB(inode->i_sb)->options.flush) { | |
121 | fat_flush_inodes(inode->i_sb, inode, NULL); | |
3fcfab16 | 122 | congestion_wait(WRITE, HZ/10); |
ae78bf9c CM |
123 | } |
124 | return 0; | |
125 | } | |
126 | ||
4b6f5d20 | 127 | const struct file_operations fat_file_operations = { |
1da177e4 LT |
128 | .llseek = generic_file_llseek, |
129 | .read = do_sync_read, | |
130 | .write = do_sync_write, | |
1da177e4 | 131 | .aio_read = generic_file_aio_read, |
ef402268 | 132 | .aio_write = generic_file_aio_write, |
1da177e4 | 133 | .mmap = generic_file_mmap, |
ae78bf9c | 134 | .release = fat_file_release, |
1da177e4 LT |
135 | .ioctl = fat_generic_ioctl, |
136 | .fsync = file_fsync, | |
5ffc4ef4 | 137 | .splice_read = generic_file_splice_read, |
1da177e4 LT |
138 | }; |
139 | ||
05eb0b51 OH |
140 | static int fat_cont_expand(struct inode *inode, loff_t size) |
141 | { | |
142 | struct address_space *mapping = inode->i_mapping; | |
143 | loff_t start = inode->i_size, count = size - inode->i_size; | |
144 | int err; | |
145 | ||
146 | err = generic_cont_expand_simple(inode, size); | |
147 | if (err) | |
148 | goto out; | |
149 | ||
150 | inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC; | |
151 | mark_inode_dirty(inode); | |
152 | if (IS_SYNC(inode)) | |
153 | err = sync_page_range_nolock(inode, mapping, start, count); | |
154 | out: | |
155 | return err; | |
156 | } | |
157 | ||
19c561a6 JE |
158 | static int check_mode(const struct msdos_sb_info *sbi, mode_t mode) |
159 | { | |
160 | mode_t req = mode & ~S_IFMT; | |
161 | ||
162 | /* | |
163 | * Of the r and x bits, all (subject to umask) must be present. Of the | |
164 | * w bits, either all (subject to umask) or none must be present. | |
165 | */ | |
166 | ||
167 | if (S_ISREG(mode)) { | |
168 | req &= ~sbi->options.fs_fmask; | |
169 | ||
170 | if ((req & (S_IRUGO | S_IXUGO)) != | |
171 | ((S_IRUGO | S_IXUGO) & ~sbi->options.fs_fmask)) | |
172 | return -EPERM; | |
173 | ||
174 | if ((req & S_IWUGO) != 0 && | |
175 | (req & S_IWUGO) != (S_IWUGO & ~sbi->options.fs_fmask)) | |
176 | return -EPERM; | |
177 | } else if (S_ISDIR(mode)) { | |
178 | req &= ~sbi->options.fs_dmask; | |
179 | ||
180 | if ((req & (S_IRUGO | S_IXUGO)) != | |
181 | ((S_IRUGO | S_IXUGO) & ~sbi->options.fs_dmask)) | |
182 | return -EPERM; | |
183 | ||
184 | if ((req & S_IWUGO) != 0 && | |
185 | (req & S_IWUGO) != (S_IWUGO & ~sbi->options.fs_dmask)) | |
186 | return -EPERM; | |
187 | } else { | |
188 | return -EPERM; | |
189 | } | |
190 | ||
191 | return 0; | |
192 | } | |
193 | ||
1da177e4 LT |
194 | int fat_notify_change(struct dentry *dentry, struct iattr *attr) |
195 | { | |
196 | struct msdos_sb_info *sbi = MSDOS_SB(dentry->d_sb); | |
197 | struct inode *inode = dentry->d_inode; | |
198 | int mask, error = 0; | |
199 | ||
200 | lock_kernel(); | |
201 | ||
05eb0b51 OH |
202 | /* |
203 | * Expand the file. Since inode_setattr() updates ->i_size | |
204 | * before calling the ->truncate(), but FAT needs to fill the | |
205 | * hole before it. | |
206 | */ | |
1da177e4 LT |
207 | if (attr->ia_valid & ATTR_SIZE) { |
208 | if (attr->ia_size > inode->i_size) { | |
05eb0b51 OH |
209 | error = fat_cont_expand(inode, attr->ia_size); |
210 | if (error || attr->ia_valid == ATTR_SIZE) | |
211 | goto out; | |
212 | attr->ia_valid &= ~ATTR_SIZE; | |
1da177e4 LT |
213 | } |
214 | } | |
215 | ||
216 | error = inode_change_ok(inode, attr); | |
217 | if (error) { | |
218 | if (sbi->options.quiet) | |
219 | error = 0; | |
220 | goto out; | |
221 | } | |
222 | if (((attr->ia_valid & ATTR_UID) && | |
223 | (attr->ia_uid != sbi->options.fs_uid)) || | |
224 | ((attr->ia_valid & ATTR_GID) && | |
19c561a6 | 225 | (attr->ia_gid != sbi->options.fs_gid))) |
1da177e4 LT |
226 | error = -EPERM; |
227 | ||
228 | if (error) { | |
229 | if (sbi->options.quiet) | |
230 | error = 0; | |
231 | goto out; | |
232 | } | |
19c561a6 JE |
233 | |
234 | if (attr->ia_valid & ATTR_MODE) { | |
235 | error = check_mode(sbi, attr->ia_mode); | |
236 | if (error != 0 && !sbi->options.quiet) | |
237 | goto out; | |
238 | } | |
239 | ||
1da177e4 LT |
240 | error = inode_setattr(inode, attr); |
241 | if (error) | |
242 | goto out; | |
243 | ||
244 | if (S_ISDIR(inode->i_mode)) | |
245 | mask = sbi->options.fs_dmask; | |
246 | else | |
247 | mask = sbi->options.fs_fmask; | |
248 | inode->i_mode &= S_IFMT | (S_IRWXUGO & ~mask); | |
249 | out: | |
250 | unlock_kernel(); | |
251 | return error; | |
252 | } | |
253 | ||
7c709d00 | 254 | EXPORT_SYMBOL_GPL(fat_notify_change); |
1da177e4 LT |
255 | |
256 | /* Free all clusters after the skip'th cluster. */ | |
257 | static int fat_free(struct inode *inode, int skip) | |
258 | { | |
259 | struct super_block *sb = inode->i_sb; | |
260 | int err, wait, free_start, i_start, i_logstart; | |
261 | ||
262 | if (MSDOS_I(inode)->i_start == 0) | |
263 | return 0; | |
264 | ||
3b641407 OH |
265 | fat_cache_inval_inode(inode); |
266 | ||
1da177e4 | 267 | wait = IS_DIRSYNC(inode); |
3b641407 OH |
268 | i_start = free_start = MSDOS_I(inode)->i_start; |
269 | i_logstart = MSDOS_I(inode)->i_logstart; | |
270 | ||
271 | /* First, we write the new file size. */ | |
272 | if (!skip) { | |
273 | MSDOS_I(inode)->i_start = 0; | |
274 | MSDOS_I(inode)->i_logstart = 0; | |
275 | } | |
276 | MSDOS_I(inode)->i_attrs |= ATTR_ARCH; | |
277 | inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC; | |
278 | if (wait) { | |
279 | err = fat_sync_inode(inode); | |
280 | if (err) { | |
281 | MSDOS_I(inode)->i_start = i_start; | |
282 | MSDOS_I(inode)->i_logstart = i_logstart; | |
283 | return err; | |
284 | } | |
285 | } else | |
286 | mark_inode_dirty(inode); | |
287 | ||
288 | /* Write a new EOF, and get the remaining cluster chain for freeing. */ | |
1da177e4 LT |
289 | if (skip) { |
290 | struct fat_entry fatent; | |
291 | int ret, fclus, dclus; | |
292 | ||
293 | ret = fat_get_cluster(inode, skip - 1, &fclus, &dclus); | |
294 | if (ret < 0) | |
295 | return ret; | |
296 | else if (ret == FAT_ENT_EOF) | |
297 | return 0; | |
298 | ||
299 | fatent_init(&fatent); | |
300 | ret = fat_ent_read(inode, &fatent, dclus); | |
301 | if (ret == FAT_ENT_EOF) { | |
302 | fatent_brelse(&fatent); | |
303 | return 0; | |
304 | } else if (ret == FAT_ENT_FREE) { | |
305 | fat_fs_panic(sb, | |
306 | "%s: invalid cluster chain (i_pos %lld)", | |
307 | __FUNCTION__, MSDOS_I(inode)->i_pos); | |
308 | ret = -EIO; | |
309 | } else if (ret > 0) { | |
310 | err = fat_ent_write(inode, &fatent, FAT_ENT_EOF, wait); | |
311 | if (err) | |
312 | ret = err; | |
313 | } | |
314 | fatent_brelse(&fatent); | |
315 | if (ret < 0) | |
316 | return ret; | |
317 | ||
318 | free_start = ret; | |
1da177e4 | 319 | } |
1da177e4 LT |
320 | inode->i_blocks = skip << (MSDOS_SB(sb)->cluster_bits - 9); |
321 | ||
322 | /* Freeing the remained cluster chain */ | |
323 | return fat_free_clusters(inode, free_start); | |
1da177e4 LT |
324 | } |
325 | ||
326 | void fat_truncate(struct inode *inode) | |
327 | { | |
328 | struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); | |
329 | const unsigned int cluster_size = sbi->cluster_size; | |
330 | int nr_clusters; | |
331 | ||
332 | /* | |
333 | * This protects against truncating a file bigger than it was then | |
334 | * trying to write into the hole. | |
335 | */ | |
336 | if (MSDOS_I(inode)->mmu_private > inode->i_size) | |
337 | MSDOS_I(inode)->mmu_private = inode->i_size; | |
338 | ||
339 | nr_clusters = (inode->i_size + (cluster_size - 1)) >> sbi->cluster_bits; | |
340 | ||
341 | lock_kernel(); | |
342 | fat_free(inode, nr_clusters); | |
343 | unlock_kernel(); | |
ae78bf9c | 344 | fat_flush_inodes(inode->i_sb, inode, NULL); |
1da177e4 LT |
345 | } |
346 | ||
da63fc7c OH |
347 | int fat_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) |
348 | { | |
349 | struct inode *inode = dentry->d_inode; | |
350 | generic_fillattr(inode, stat); | |
351 | stat->blksize = MSDOS_SB(inode->i_sb)->cluster_size; | |
352 | return 0; | |
353 | } | |
354 | EXPORT_SYMBOL_GPL(fat_getattr); | |
355 | ||
754661f1 | 356 | const struct inode_operations fat_file_inode_operations = { |
1da177e4 LT |
357 | .truncate = fat_truncate, |
358 | .setattr = fat_notify_change, | |
da63fc7c | 359 | .getattr = fat_getattr, |
1da177e4 | 360 | }; |