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 | ||
15 | static ssize_t fat_file_aio_write(struct kiocb *iocb, const char __user *buf, | |
16 | size_t count, loff_t pos) | |
17 | { | |
18 | struct inode *inode = iocb->ki_filp->f_dentry->d_inode; | |
19 | int retval; | |
20 | ||
21 | retval = generic_file_aio_write(iocb, buf, count, pos); | |
22 | if (retval > 0) { | |
23 | inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC; | |
24 | MSDOS_I(inode)->i_attrs |= ATTR_ARCH; | |
25 | mark_inode_dirty(inode); | |
26 | // check the locking rules | |
27 | // if (IS_SYNC(inode)) | |
28 | // fat_sync_inode(inode); | |
29 | } | |
30 | return retval; | |
31 | } | |
32 | ||
33 | static ssize_t fat_file_writev(struct file *filp, const struct iovec *iov, | |
34 | unsigned long nr_segs, loff_t *ppos) | |
35 | { | |
36 | struct inode *inode = filp->f_dentry->d_inode; | |
37 | int retval; | |
38 | ||
39 | retval = generic_file_writev(filp, iov, nr_segs, ppos); | |
40 | if (retval > 0) { | |
41 | inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC; | |
42 | MSDOS_I(inode)->i_attrs |= ATTR_ARCH; | |
43 | mark_inode_dirty(inode); | |
44 | } | |
45 | return retval; | |
46 | } | |
47 | ||
48 | int fat_generic_ioctl(struct inode *inode, struct file *filp, | |
49 | unsigned int cmd, unsigned long arg) | |
50 | { | |
51 | struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); | |
52 | u32 __user *user_attr = (u32 __user *)arg; | |
53 | ||
54 | switch (cmd) { | |
55 | case FAT_IOCTL_GET_ATTRIBUTES: | |
56 | { | |
57 | u32 attr; | |
58 | ||
59 | if (inode->i_ino == MSDOS_ROOT_INO) | |
60 | attr = ATTR_DIR; | |
61 | else | |
62 | attr = fat_attr(inode); | |
63 | ||
64 | return put_user(attr, user_attr); | |
65 | } | |
66 | case FAT_IOCTL_SET_ATTRIBUTES: | |
67 | { | |
68 | u32 attr, oldattr; | |
69 | int err, is_dir = S_ISDIR(inode->i_mode); | |
70 | struct iattr ia; | |
71 | ||
72 | err = get_user(attr, user_attr); | |
73 | if (err) | |
74 | return err; | |
75 | ||
76 | down(&inode->i_sem); | |
77 | ||
78 | if (IS_RDONLY(inode)) { | |
79 | err = -EROFS; | |
80 | goto up; | |
81 | } | |
82 | ||
83 | /* | |
84 | * ATTR_VOLUME and ATTR_DIR cannot be changed; this also | |
85 | * prevents the user from turning us into a VFAT | |
86 | * longname entry. Also, we obviously can't set | |
87 | * any of the NTFS attributes in the high 24 bits. | |
88 | */ | |
89 | attr &= 0xff & ~(ATTR_VOLUME | ATTR_DIR); | |
90 | /* Merge in ATTR_VOLUME and ATTR_DIR */ | |
91 | attr |= (MSDOS_I(inode)->i_attrs & ATTR_VOLUME) | | |
92 | (is_dir ? ATTR_DIR : 0); | |
93 | oldattr = fat_attr(inode); | |
94 | ||
95 | /* Equivalent to a chmod() */ | |
96 | ia.ia_valid = ATTR_MODE | ATTR_CTIME; | |
97 | if (is_dir) { | |
98 | ia.ia_mode = MSDOS_MKMODE(attr, | |
99 | S_IRWXUGO & ~sbi->options.fs_dmask) | |
100 | | S_IFDIR; | |
101 | } else { | |
102 | ia.ia_mode = MSDOS_MKMODE(attr, | |
103 | (S_IRUGO | S_IWUGO | (inode->i_mode & S_IXUGO)) | |
104 | & ~sbi->options.fs_fmask) | |
105 | | S_IFREG; | |
106 | } | |
107 | ||
108 | /* The root directory has no attributes */ | |
109 | if (inode->i_ino == MSDOS_ROOT_INO && attr != ATTR_DIR) { | |
110 | err = -EINVAL; | |
111 | goto up; | |
112 | } | |
113 | ||
114 | if (sbi->options.sys_immutable) { | |
115 | if ((attr | oldattr) & ATTR_SYS) { | |
116 | if (!capable(CAP_LINUX_IMMUTABLE)) { | |
117 | err = -EPERM; | |
118 | goto up; | |
119 | } | |
120 | } | |
121 | } | |
122 | ||
123 | /* This MUST be done before doing anything irreversible... */ | |
124 | err = notify_change(filp->f_dentry, &ia); | |
125 | if (err) | |
126 | goto up; | |
127 | ||
128 | if (sbi->options.sys_immutable) { | |
129 | if (attr & ATTR_SYS) | |
130 | inode->i_flags |= S_IMMUTABLE; | |
131 | else | |
132 | inode->i_flags &= S_IMMUTABLE; | |
133 | } | |
134 | ||
135 | MSDOS_I(inode)->i_attrs = attr & ATTR_UNUSED; | |
136 | mark_inode_dirty(inode); | |
137 | up: | |
138 | up(&inode->i_sem); | |
139 | return err; | |
140 | } | |
141 | default: | |
142 | return -ENOTTY; /* Inappropriate ioctl for device */ | |
143 | } | |
144 | } | |
145 | ||
146 | struct file_operations fat_file_operations = { | |
147 | .llseek = generic_file_llseek, | |
148 | .read = do_sync_read, | |
149 | .write = do_sync_write, | |
150 | .readv = generic_file_readv, | |
151 | .writev = fat_file_writev, | |
152 | .aio_read = generic_file_aio_read, | |
153 | .aio_write = fat_file_aio_write, | |
154 | .mmap = generic_file_mmap, | |
155 | .ioctl = fat_generic_ioctl, | |
156 | .fsync = file_fsync, | |
157 | .sendfile = generic_file_sendfile, | |
158 | }; | |
159 | ||
160 | int fat_notify_change(struct dentry *dentry, struct iattr *attr) | |
161 | { | |
162 | struct msdos_sb_info *sbi = MSDOS_SB(dentry->d_sb); | |
163 | struct inode *inode = dentry->d_inode; | |
164 | int mask, error = 0; | |
165 | ||
166 | lock_kernel(); | |
167 | ||
168 | /* FAT cannot truncate to a longer file */ | |
169 | if (attr->ia_valid & ATTR_SIZE) { | |
170 | if (attr->ia_size > inode->i_size) { | |
171 | error = -EPERM; | |
172 | goto out; | |
173 | } | |
174 | } | |
175 | ||
176 | error = inode_change_ok(inode, attr); | |
177 | if (error) { | |
178 | if (sbi->options.quiet) | |
179 | error = 0; | |
180 | goto out; | |
181 | } | |
182 | if (((attr->ia_valid & ATTR_UID) && | |
183 | (attr->ia_uid != sbi->options.fs_uid)) || | |
184 | ((attr->ia_valid & ATTR_GID) && | |
185 | (attr->ia_gid != sbi->options.fs_gid)) || | |
186 | ((attr->ia_valid & ATTR_MODE) && | |
187 | (attr->ia_mode & ~MSDOS_VALID_MODE))) | |
188 | error = -EPERM; | |
189 | ||
190 | if (error) { | |
191 | if (sbi->options.quiet) | |
192 | error = 0; | |
193 | goto out; | |
194 | } | |
195 | error = inode_setattr(inode, attr); | |
196 | if (error) | |
197 | goto out; | |
198 | ||
199 | if (S_ISDIR(inode->i_mode)) | |
200 | mask = sbi->options.fs_dmask; | |
201 | else | |
202 | mask = sbi->options.fs_fmask; | |
203 | inode->i_mode &= S_IFMT | (S_IRWXUGO & ~mask); | |
204 | out: | |
205 | unlock_kernel(); | |
206 | return error; | |
207 | } | |
208 | ||
209 | EXPORT_SYMBOL(fat_notify_change); | |
210 | ||
211 | /* Free all clusters after the skip'th cluster. */ | |
212 | static int fat_free(struct inode *inode, int skip) | |
213 | { | |
214 | struct super_block *sb = inode->i_sb; | |
215 | int err, wait, free_start, i_start, i_logstart; | |
216 | ||
217 | if (MSDOS_I(inode)->i_start == 0) | |
218 | return 0; | |
219 | ||
220 | /* | |
221 | * Write a new EOF, and get the remaining cluster chain for freeing. | |
222 | */ | |
223 | wait = IS_DIRSYNC(inode); | |
224 | if (skip) { | |
225 | struct fat_entry fatent; | |
226 | int ret, fclus, dclus; | |
227 | ||
228 | ret = fat_get_cluster(inode, skip - 1, &fclus, &dclus); | |
229 | if (ret < 0) | |
230 | return ret; | |
231 | else if (ret == FAT_ENT_EOF) | |
232 | return 0; | |
233 | ||
234 | fatent_init(&fatent); | |
235 | ret = fat_ent_read(inode, &fatent, dclus); | |
236 | if (ret == FAT_ENT_EOF) { | |
237 | fatent_brelse(&fatent); | |
238 | return 0; | |
239 | } else if (ret == FAT_ENT_FREE) { | |
240 | fat_fs_panic(sb, | |
241 | "%s: invalid cluster chain (i_pos %lld)", | |
242 | __FUNCTION__, MSDOS_I(inode)->i_pos); | |
243 | ret = -EIO; | |
244 | } else if (ret > 0) { | |
245 | err = fat_ent_write(inode, &fatent, FAT_ENT_EOF, wait); | |
246 | if (err) | |
247 | ret = err; | |
248 | } | |
249 | fatent_brelse(&fatent); | |
250 | if (ret < 0) | |
251 | return ret; | |
252 | ||
253 | free_start = ret; | |
254 | i_start = i_logstart = 0; | |
255 | fat_cache_inval_inode(inode); | |
256 | } else { | |
257 | fat_cache_inval_inode(inode); | |
258 | ||
259 | i_start = free_start = MSDOS_I(inode)->i_start; | |
260 | i_logstart = MSDOS_I(inode)->i_logstart; | |
261 | MSDOS_I(inode)->i_start = 0; | |
262 | MSDOS_I(inode)->i_logstart = 0; | |
263 | } | |
264 | MSDOS_I(inode)->i_attrs |= ATTR_ARCH; | |
265 | inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC; | |
266 | if (wait) { | |
267 | err = fat_sync_inode(inode); | |
268 | if (err) | |
269 | goto error; | |
270 | } else | |
271 | mark_inode_dirty(inode); | |
272 | inode->i_blocks = skip << (MSDOS_SB(sb)->cluster_bits - 9); | |
273 | ||
274 | /* Freeing the remained cluster chain */ | |
275 | return fat_free_clusters(inode, free_start); | |
276 | ||
277 | error: | |
278 | if (i_start) { | |
279 | MSDOS_I(inode)->i_start = i_start; | |
280 | MSDOS_I(inode)->i_logstart = i_logstart; | |
281 | } | |
282 | return err; | |
283 | } | |
284 | ||
285 | void fat_truncate(struct inode *inode) | |
286 | { | |
287 | struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); | |
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 | */ | |
295 | if (MSDOS_I(inode)->mmu_private > inode->i_size) | |
296 | MSDOS_I(inode)->mmu_private = inode->i_size; | |
297 | ||
298 | nr_clusters = (inode->i_size + (cluster_size - 1)) >> sbi->cluster_bits; | |
299 | ||
300 | lock_kernel(); | |
301 | fat_free(inode, nr_clusters); | |
302 | unlock_kernel(); | |
303 | } | |
304 | ||
305 | struct inode_operations fat_file_inode_operations = { | |
306 | .truncate = fat_truncate, | |
307 | .setattr = fat_notify_change, | |
308 | }; |