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Commit | Line | Data |
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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 | ||
9 | #include <linux/module.h> | |
10 | #include <linux/time.h> | |
11 | #include <linux/msdos_fs.h> | |
12 | #include <linux/smp_lock.h> | |
13 | #include <linux/buffer_head.h> | |
05eb0b51 | 14 | #include <linux/writeback.h> |
1da177e4 | 15 | |
1da177e4 LT |
16 | int fat_generic_ioctl(struct inode *inode, struct file *filp, |
17 | unsigned int cmd, unsigned long arg) | |
18 | { | |
19 | struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); | |
20 | u32 __user *user_attr = (u32 __user *)arg; | |
21 | ||
22 | switch (cmd) { | |
23 | case FAT_IOCTL_GET_ATTRIBUTES: | |
24 | { | |
25 | u32 attr; | |
26 | ||
27 | if (inode->i_ino == MSDOS_ROOT_INO) | |
28 | attr = ATTR_DIR; | |
29 | else | |
30 | attr = fat_attr(inode); | |
31 | ||
32 | return put_user(attr, user_attr); | |
33 | } | |
34 | case FAT_IOCTL_SET_ATTRIBUTES: | |
35 | { | |
36 | u32 attr, oldattr; | |
37 | int err, is_dir = S_ISDIR(inode->i_mode); | |
38 | struct iattr ia; | |
39 | ||
40 | err = get_user(attr, user_attr); | |
41 | if (err) | |
42 | return err; | |
43 | ||
1b1dcc1b | 44 | mutex_lock(&inode->i_mutex); |
1da177e4 LT |
45 | |
46 | if (IS_RDONLY(inode)) { | |
47 | err = -EROFS; | |
48 | goto up; | |
49 | } | |
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_attr(inode); | |
62 | ||
63 | /* Equivalent to a chmod() */ | |
64 | ia.ia_valid = ATTR_MODE | ATTR_CTIME; | |
65 | if (is_dir) { | |
66 | ia.ia_mode = MSDOS_MKMODE(attr, | |
67 | S_IRWXUGO & ~sbi->options.fs_dmask) | |
68 | | S_IFDIR; | |
69 | } else { | |
70 | ia.ia_mode = MSDOS_MKMODE(attr, | |
71 | (S_IRUGO | S_IWUGO | (inode->i_mode & S_IXUGO)) | |
72 | & ~sbi->options.fs_fmask) | |
73 | | S_IFREG; | |
74 | } | |
75 | ||
76 | /* The root directory has no attributes */ | |
77 | if (inode->i_ino == MSDOS_ROOT_INO && attr != ATTR_DIR) { | |
78 | err = -EINVAL; | |
79 | goto up; | |
80 | } | |
81 | ||
82 | if (sbi->options.sys_immutable) { | |
83 | if ((attr | oldattr) & ATTR_SYS) { | |
84 | if (!capable(CAP_LINUX_IMMUTABLE)) { | |
85 | err = -EPERM; | |
86 | goto up; | |
87 | } | |
88 | } | |
89 | } | |
90 | ||
91 | /* This MUST be done before doing anything irreversible... */ | |
92 | err = notify_change(filp->f_dentry, &ia); | |
93 | if (err) | |
94 | goto up; | |
95 | ||
96 | if (sbi->options.sys_immutable) { | |
97 | if (attr & ATTR_SYS) | |
98 | inode->i_flags |= S_IMMUTABLE; | |
99 | else | |
100 | inode->i_flags &= S_IMMUTABLE; | |
101 | } | |
102 | ||
103 | MSDOS_I(inode)->i_attrs = attr & ATTR_UNUSED; | |
104 | mark_inode_dirty(inode); | |
105 | up: | |
1b1dcc1b | 106 | mutex_unlock(&inode->i_mutex); |
1da177e4 LT |
107 | return err; |
108 | } | |
109 | default: | |
110 | return -ENOTTY; /* Inappropriate ioctl for device */ | |
111 | } | |
112 | } | |
113 | ||
114 | struct file_operations fat_file_operations = { | |
115 | .llseek = generic_file_llseek, | |
116 | .read = do_sync_read, | |
117 | .write = do_sync_write, | |
118 | .readv = generic_file_readv, | |
ef402268 | 119 | .writev = generic_file_writev, |
1da177e4 | 120 | .aio_read = generic_file_aio_read, |
ef402268 | 121 | .aio_write = generic_file_aio_write, |
1da177e4 LT |
122 | .mmap = generic_file_mmap, |
123 | .ioctl = fat_generic_ioctl, | |
124 | .fsync = file_fsync, | |
125 | .sendfile = generic_file_sendfile, | |
126 | }; | |
127 | ||
05eb0b51 OH |
128 | static int fat_cont_expand(struct inode *inode, loff_t size) |
129 | { | |
130 | struct address_space *mapping = inode->i_mapping; | |
131 | loff_t start = inode->i_size, count = size - inode->i_size; | |
132 | int err; | |
133 | ||
134 | err = generic_cont_expand_simple(inode, size); | |
135 | if (err) | |
136 | goto out; | |
137 | ||
138 | inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC; | |
139 | mark_inode_dirty(inode); | |
140 | if (IS_SYNC(inode)) | |
141 | err = sync_page_range_nolock(inode, mapping, start, count); | |
142 | out: | |
143 | return err; | |
144 | } | |
145 | ||
1da177e4 LT |
146 | int fat_notify_change(struct dentry *dentry, struct iattr *attr) |
147 | { | |
148 | struct msdos_sb_info *sbi = MSDOS_SB(dentry->d_sb); | |
149 | struct inode *inode = dentry->d_inode; | |
150 | int mask, error = 0; | |
151 | ||
152 | lock_kernel(); | |
153 | ||
05eb0b51 OH |
154 | /* |
155 | * Expand the file. Since inode_setattr() updates ->i_size | |
156 | * before calling the ->truncate(), but FAT needs to fill the | |
157 | * hole before it. | |
158 | */ | |
1da177e4 LT |
159 | if (attr->ia_valid & ATTR_SIZE) { |
160 | if (attr->ia_size > inode->i_size) { | |
05eb0b51 OH |
161 | error = fat_cont_expand(inode, attr->ia_size); |
162 | if (error || attr->ia_valid == ATTR_SIZE) | |
163 | goto out; | |
164 | attr->ia_valid &= ~ATTR_SIZE; | |
1da177e4 LT |
165 | } |
166 | } | |
167 | ||
168 | error = inode_change_ok(inode, attr); | |
169 | if (error) { | |
170 | if (sbi->options.quiet) | |
171 | error = 0; | |
172 | goto out; | |
173 | } | |
174 | if (((attr->ia_valid & ATTR_UID) && | |
175 | (attr->ia_uid != sbi->options.fs_uid)) || | |
176 | ((attr->ia_valid & ATTR_GID) && | |
177 | (attr->ia_gid != sbi->options.fs_gid)) || | |
178 | ((attr->ia_valid & ATTR_MODE) && | |
179 | (attr->ia_mode & ~MSDOS_VALID_MODE))) | |
180 | error = -EPERM; | |
181 | ||
182 | if (error) { | |
183 | if (sbi->options.quiet) | |
184 | error = 0; | |
185 | goto out; | |
186 | } | |
187 | error = inode_setattr(inode, attr); | |
188 | if (error) | |
189 | goto out; | |
190 | ||
191 | if (S_ISDIR(inode->i_mode)) | |
192 | mask = sbi->options.fs_dmask; | |
193 | else | |
194 | mask = sbi->options.fs_fmask; | |
195 | inode->i_mode &= S_IFMT | (S_IRWXUGO & ~mask); | |
196 | out: | |
197 | unlock_kernel(); | |
198 | return error; | |
199 | } | |
200 | ||
7c709d00 | 201 | EXPORT_SYMBOL_GPL(fat_notify_change); |
1da177e4 LT |
202 | |
203 | /* Free all clusters after the skip'th cluster. */ | |
204 | static int fat_free(struct inode *inode, int skip) | |
205 | { | |
206 | struct super_block *sb = inode->i_sb; | |
207 | int err, wait, free_start, i_start, i_logstart; | |
208 | ||
209 | if (MSDOS_I(inode)->i_start == 0) | |
210 | return 0; | |
211 | ||
212 | /* | |
213 | * Write a new EOF, and get the remaining cluster chain for freeing. | |
214 | */ | |
215 | wait = IS_DIRSYNC(inode); | |
216 | if (skip) { | |
217 | struct fat_entry fatent; | |
218 | int ret, fclus, dclus; | |
219 | ||
220 | ret = fat_get_cluster(inode, skip - 1, &fclus, &dclus); | |
221 | if (ret < 0) | |
222 | return ret; | |
223 | else if (ret == FAT_ENT_EOF) | |
224 | return 0; | |
225 | ||
226 | fatent_init(&fatent); | |
227 | ret = fat_ent_read(inode, &fatent, dclus); | |
228 | if (ret == FAT_ENT_EOF) { | |
229 | fatent_brelse(&fatent); | |
230 | return 0; | |
231 | } else if (ret == FAT_ENT_FREE) { | |
232 | fat_fs_panic(sb, | |
233 | "%s: invalid cluster chain (i_pos %lld)", | |
234 | __FUNCTION__, MSDOS_I(inode)->i_pos); | |
235 | ret = -EIO; | |
236 | } else if (ret > 0) { | |
237 | err = fat_ent_write(inode, &fatent, FAT_ENT_EOF, wait); | |
238 | if (err) | |
239 | ret = err; | |
240 | } | |
241 | fatent_brelse(&fatent); | |
242 | if (ret < 0) | |
243 | return ret; | |
244 | ||
245 | free_start = ret; | |
246 | i_start = i_logstart = 0; | |
247 | fat_cache_inval_inode(inode); | |
248 | } else { | |
249 | fat_cache_inval_inode(inode); | |
250 | ||
251 | i_start = free_start = MSDOS_I(inode)->i_start; | |
252 | i_logstart = MSDOS_I(inode)->i_logstart; | |
253 | MSDOS_I(inode)->i_start = 0; | |
254 | MSDOS_I(inode)->i_logstart = 0; | |
255 | } | |
256 | MSDOS_I(inode)->i_attrs |= ATTR_ARCH; | |
257 | inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC; | |
258 | if (wait) { | |
259 | err = fat_sync_inode(inode); | |
260 | if (err) | |
261 | goto error; | |
262 | } else | |
263 | mark_inode_dirty(inode); | |
264 | inode->i_blocks = skip << (MSDOS_SB(sb)->cluster_bits - 9); | |
265 | ||
266 | /* Freeing the remained cluster chain */ | |
267 | return fat_free_clusters(inode, free_start); | |
268 | ||
269 | error: | |
270 | if (i_start) { | |
271 | MSDOS_I(inode)->i_start = i_start; | |
272 | MSDOS_I(inode)->i_logstart = i_logstart; | |
273 | } | |
274 | return err; | |
275 | } | |
276 | ||
277 | void fat_truncate(struct inode *inode) | |
278 | { | |
279 | struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); | |
280 | const unsigned int cluster_size = sbi->cluster_size; | |
281 | int nr_clusters; | |
282 | ||
283 | /* | |
284 | * This protects against truncating a file bigger than it was then | |
285 | * trying to write into the hole. | |
286 | */ | |
287 | if (MSDOS_I(inode)->mmu_private > inode->i_size) | |
288 | MSDOS_I(inode)->mmu_private = inode->i_size; | |
289 | ||
290 | nr_clusters = (inode->i_size + (cluster_size - 1)) >> sbi->cluster_bits; | |
291 | ||
292 | lock_kernel(); | |
293 | fat_free(inode, nr_clusters); | |
294 | unlock_kernel(); | |
295 | } | |
296 | ||
297 | struct inode_operations fat_file_inode_operations = { | |
298 | .truncate = fat_truncate, | |
299 | .setattr = fat_notify_change, | |
300 | }; |