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 | ||
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> | |
14 | ||
1da177e4 LT |
15 | int fat_generic_ioctl(struct inode *inode, struct file *filp, |
16 | unsigned int cmd, unsigned long arg) | |
17 | { | |
18 | struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); | |
19 | u32 __user *user_attr = (u32 __user *)arg; | |
20 | ||
21 | switch (cmd) { | |
22 | case FAT_IOCTL_GET_ATTRIBUTES: | |
23 | { | |
24 | u32 attr; | |
25 | ||
26 | if (inode->i_ino == MSDOS_ROOT_INO) | |
27 | attr = ATTR_DIR; | |
28 | else | |
29 | attr = fat_attr(inode); | |
30 | ||
31 | return put_user(attr, user_attr); | |
32 | } | |
33 | case FAT_IOCTL_SET_ATTRIBUTES: | |
34 | { | |
35 | u32 attr, oldattr; | |
36 | int err, is_dir = S_ISDIR(inode->i_mode); | |
37 | struct iattr ia; | |
38 | ||
39 | err = get_user(attr, user_attr); | |
40 | if (err) | |
41 | return err; | |
42 | ||
43 | down(&inode->i_sem); | |
44 | ||
45 | if (IS_RDONLY(inode)) { | |
46 | err = -EROFS; | |
47 | goto up; | |
48 | } | |
49 | ||
50 | /* | |
51 | * ATTR_VOLUME and ATTR_DIR cannot be changed; this also | |
52 | * prevents the user from turning us into a VFAT | |
53 | * longname entry. Also, we obviously can't set | |
54 | * any of the NTFS attributes in the high 24 bits. | |
55 | */ | |
56 | attr &= 0xff & ~(ATTR_VOLUME | ATTR_DIR); | |
57 | /* Merge in ATTR_VOLUME and ATTR_DIR */ | |
58 | attr |= (MSDOS_I(inode)->i_attrs & ATTR_VOLUME) | | |
59 | (is_dir ? ATTR_DIR : 0); | |
60 | oldattr = fat_attr(inode); | |
61 | ||
62 | /* Equivalent to a chmod() */ | |
63 | ia.ia_valid = ATTR_MODE | ATTR_CTIME; | |
64 | if (is_dir) { | |
65 | ia.ia_mode = MSDOS_MKMODE(attr, | |
66 | S_IRWXUGO & ~sbi->options.fs_dmask) | |
67 | | S_IFDIR; | |
68 | } else { | |
69 | ia.ia_mode = MSDOS_MKMODE(attr, | |
70 | (S_IRUGO | S_IWUGO | (inode->i_mode & S_IXUGO)) | |
71 | & ~sbi->options.fs_fmask) | |
72 | | S_IFREG; | |
73 | } | |
74 | ||
75 | /* The root directory has no attributes */ | |
76 | if (inode->i_ino == MSDOS_ROOT_INO && attr != ATTR_DIR) { | |
77 | err = -EINVAL; | |
78 | goto up; | |
79 | } | |
80 | ||
81 | if (sbi->options.sys_immutable) { | |
82 | if ((attr | oldattr) & ATTR_SYS) { | |
83 | if (!capable(CAP_LINUX_IMMUTABLE)) { | |
84 | err = -EPERM; | |
85 | goto up; | |
86 | } | |
87 | } | |
88 | } | |
89 | ||
90 | /* This MUST be done before doing anything irreversible... */ | |
91 | err = notify_change(filp->f_dentry, &ia); | |
92 | if (err) | |
93 | goto up; | |
94 | ||
95 | if (sbi->options.sys_immutable) { | |
96 | if (attr & ATTR_SYS) | |
97 | inode->i_flags |= S_IMMUTABLE; | |
98 | else | |
99 | inode->i_flags &= S_IMMUTABLE; | |
100 | } | |
101 | ||
102 | MSDOS_I(inode)->i_attrs = attr & ATTR_UNUSED; | |
103 | mark_inode_dirty(inode); | |
104 | up: | |
105 | up(&inode->i_sem); | |
106 | return err; | |
107 | } | |
108 | default: | |
109 | return -ENOTTY; /* Inappropriate ioctl for device */ | |
110 | } | |
111 | } | |
112 | ||
113 | struct file_operations fat_file_operations = { | |
114 | .llseek = generic_file_llseek, | |
115 | .read = do_sync_read, | |
116 | .write = do_sync_write, | |
117 | .readv = generic_file_readv, | |
ef402268 | 118 | .writev = generic_file_writev, |
1da177e4 | 119 | .aio_read = generic_file_aio_read, |
ef402268 | 120 | .aio_write = generic_file_aio_write, |
1da177e4 LT |
121 | .mmap = generic_file_mmap, |
122 | .ioctl = fat_generic_ioctl, | |
123 | .fsync = file_fsync, | |
124 | .sendfile = generic_file_sendfile, | |
125 | }; | |
126 | ||
127 | int fat_notify_change(struct dentry *dentry, struct iattr *attr) | |
128 | { | |
129 | struct msdos_sb_info *sbi = MSDOS_SB(dentry->d_sb); | |
130 | struct inode *inode = dentry->d_inode; | |
131 | int mask, error = 0; | |
132 | ||
133 | lock_kernel(); | |
134 | ||
135 | /* FAT cannot truncate to a longer file */ | |
136 | if (attr->ia_valid & ATTR_SIZE) { | |
137 | if (attr->ia_size > inode->i_size) { | |
138 | error = -EPERM; | |
139 | goto out; | |
140 | } | |
141 | } | |
142 | ||
143 | error = inode_change_ok(inode, attr); | |
144 | if (error) { | |
145 | if (sbi->options.quiet) | |
146 | error = 0; | |
147 | goto out; | |
148 | } | |
149 | if (((attr->ia_valid & ATTR_UID) && | |
150 | (attr->ia_uid != sbi->options.fs_uid)) || | |
151 | ((attr->ia_valid & ATTR_GID) && | |
152 | (attr->ia_gid != sbi->options.fs_gid)) || | |
153 | ((attr->ia_valid & ATTR_MODE) && | |
154 | (attr->ia_mode & ~MSDOS_VALID_MODE))) | |
155 | error = -EPERM; | |
156 | ||
157 | if (error) { | |
158 | if (sbi->options.quiet) | |
159 | error = 0; | |
160 | goto out; | |
161 | } | |
162 | error = inode_setattr(inode, attr); | |
163 | if (error) | |
164 | goto out; | |
165 | ||
166 | if (S_ISDIR(inode->i_mode)) | |
167 | mask = sbi->options.fs_dmask; | |
168 | else | |
169 | mask = sbi->options.fs_fmask; | |
170 | inode->i_mode &= S_IFMT | (S_IRWXUGO & ~mask); | |
171 | out: | |
172 | unlock_kernel(); | |
173 | return error; | |
174 | } | |
175 | ||
7c709d00 | 176 | EXPORT_SYMBOL_GPL(fat_notify_change); |
1da177e4 LT |
177 | |
178 | /* Free all clusters after the skip'th cluster. */ | |
179 | static int fat_free(struct inode *inode, int skip) | |
180 | { | |
181 | struct super_block *sb = inode->i_sb; | |
182 | int err, wait, free_start, i_start, i_logstart; | |
183 | ||
184 | if (MSDOS_I(inode)->i_start == 0) | |
185 | return 0; | |
186 | ||
187 | /* | |
188 | * Write a new EOF, and get the remaining cluster chain for freeing. | |
189 | */ | |
190 | wait = IS_DIRSYNC(inode); | |
191 | if (skip) { | |
192 | struct fat_entry fatent; | |
193 | int ret, fclus, dclus; | |
194 | ||
195 | ret = fat_get_cluster(inode, skip - 1, &fclus, &dclus); | |
196 | if (ret < 0) | |
197 | return ret; | |
198 | else if (ret == FAT_ENT_EOF) | |
199 | return 0; | |
200 | ||
201 | fatent_init(&fatent); | |
202 | ret = fat_ent_read(inode, &fatent, dclus); | |
203 | if (ret == FAT_ENT_EOF) { | |
204 | fatent_brelse(&fatent); | |
205 | return 0; | |
206 | } else if (ret == FAT_ENT_FREE) { | |
207 | fat_fs_panic(sb, | |
208 | "%s: invalid cluster chain (i_pos %lld)", | |
209 | __FUNCTION__, MSDOS_I(inode)->i_pos); | |
210 | ret = -EIO; | |
211 | } else if (ret > 0) { | |
212 | err = fat_ent_write(inode, &fatent, FAT_ENT_EOF, wait); | |
213 | if (err) | |
214 | ret = err; | |
215 | } | |
216 | fatent_brelse(&fatent); | |
217 | if (ret < 0) | |
218 | return ret; | |
219 | ||
220 | free_start = ret; | |
221 | i_start = i_logstart = 0; | |
222 | fat_cache_inval_inode(inode); | |
223 | } else { | |
224 | fat_cache_inval_inode(inode); | |
225 | ||
226 | i_start = free_start = MSDOS_I(inode)->i_start; | |
227 | i_logstart = MSDOS_I(inode)->i_logstart; | |
228 | MSDOS_I(inode)->i_start = 0; | |
229 | MSDOS_I(inode)->i_logstart = 0; | |
230 | } | |
231 | MSDOS_I(inode)->i_attrs |= ATTR_ARCH; | |
232 | inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC; | |
233 | if (wait) { | |
234 | err = fat_sync_inode(inode); | |
235 | if (err) | |
236 | goto error; | |
237 | } else | |
238 | mark_inode_dirty(inode); | |
239 | inode->i_blocks = skip << (MSDOS_SB(sb)->cluster_bits - 9); | |
240 | ||
241 | /* Freeing the remained cluster chain */ | |
242 | return fat_free_clusters(inode, free_start); | |
243 | ||
244 | error: | |
245 | if (i_start) { | |
246 | MSDOS_I(inode)->i_start = i_start; | |
247 | MSDOS_I(inode)->i_logstart = i_logstart; | |
248 | } | |
249 | return err; | |
250 | } | |
251 | ||
252 | void fat_truncate(struct inode *inode) | |
253 | { | |
254 | struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); | |
255 | const unsigned int cluster_size = sbi->cluster_size; | |
256 | int nr_clusters; | |
257 | ||
258 | /* | |
259 | * This protects against truncating a file bigger than it was then | |
260 | * trying to write into the hole. | |
261 | */ | |
262 | if (MSDOS_I(inode)->mmu_private > inode->i_size) | |
263 | MSDOS_I(inode)->mmu_private = inode->i_size; | |
264 | ||
265 | nr_clusters = (inode->i_size + (cluster_size - 1)) >> sbi->cluster_bits; | |
266 | ||
267 | lock_kernel(); | |
268 | fat_free(inode, nr_clusters); | |
269 | unlock_kernel(); | |
270 | } | |
271 | ||
272 | struct inode_operations fat_file_inode_operations = { | |
273 | .truncate = fat_truncate, | |
274 | .setattr = fat_notify_change, | |
275 | }; |