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9#include <linux/capability.h>
10#include <linux/module.h>
11#include <linux/mount.h>
12#include <linux/time.h>
13#include <linux/buffer_head.h>
14#include <linux/writeback.h>
15#include <linux/backing-dev.h>
16#include <linux/blkdev.h>
17#include <linux/fsnotify.h>
18#include <linux/security.h>
19#include "fat.h"
20
21static int fat_ioctl_get_attributes(struct inode *inode, u32 __user *user_attr)
22{
23 u32 attr;
24
25 mutex_lock(&inode->i_mutex);
26 attr = fat_make_attrs(inode);
27 mutex_unlock(&inode->i_mutex);
28
29 return put_user(attr, user_attr);
30}
31
32static int fat_ioctl_set_attributes(struct file *file, u32 __user *user_attr)
33{
34 struct inode *inode = file->f_path.dentry->d_inode;
35 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
36 int is_dir = S_ISDIR(inode->i_mode);
37 u32 attr, oldattr;
38 struct iattr ia;
39 int err;
40
41 err = get_user(attr, user_attr);
42 if (err)
43 goto out;
44
45 mutex_lock(&inode->i_mutex);
46 err = mnt_want_write(file->f_path.mnt);
47 if (err)
48 goto out_unlock_inode;
49
50
51
52
53
54
55
56 attr &= 0xff & ~(ATTR_VOLUME | ATTR_DIR);
57
58 attr |= (MSDOS_I(inode)->i_attrs & ATTR_VOLUME) |
59 (is_dir ? ATTR_DIR : 0);
60 oldattr = fat_make_attrs(inode);
61
62
63 ia.ia_valid = ATTR_MODE | ATTR_CTIME;
64 ia.ia_ctime = current_fs_time(inode->i_sb);
65 if (is_dir)
66 ia.ia_mode = fat_make_mode(sbi, attr, S_IRWXUGO);
67 else {
68 ia.ia_mode = fat_make_mode(sbi, attr,
69 S_IRUGO | S_IWUGO | (inode->i_mode & S_IXUGO));
70 }
71
72
73 if (inode->i_ino == MSDOS_ROOT_INO && attr != ATTR_DIR) {
74 err = -EINVAL;
75 goto out_drop_write;
76 }
77
78 if (sbi->options.sys_immutable &&
79 ((attr | oldattr) & ATTR_SYS) &&
80 !capable(CAP_LINUX_IMMUTABLE)) {
81 err = -EPERM;
82 goto out_drop_write;
83 }
84
85
86
87
88
89
90 err = security_inode_setattr(file->f_path.dentry, &ia);
91 if (err)
92 goto out_drop_write;
93
94
95 err = fat_setattr(file->f_path.dentry, &ia);
96 if (err)
97 goto out_drop_write;
98
99 fsnotify_change(file->f_path.dentry, ia.ia_valid);
100 if (sbi->options.sys_immutable) {
101 if (attr & ATTR_SYS)
102 inode->i_flags |= S_IMMUTABLE;
103 else
104 inode->i_flags &= S_IMMUTABLE;
105 }
106
107 fat_save_attrs(inode, attr);
108 mark_inode_dirty(inode);
109out_drop_write:
110 mnt_drop_write(file->f_path.mnt);
111out_unlock_inode:
112 mutex_unlock(&inode->i_mutex);
113out:
114 return err;
115}
116
117int fat_generic_ioctl(struct inode *inode, struct file *filp,
118 unsigned int cmd, unsigned long arg)
119{
120 u32 __user *user_attr = (u32 __user *)arg;
121
122 switch (cmd) {
123 case FAT_IOCTL_GET_ATTRIBUTES:
124 return fat_ioctl_get_attributes(inode, user_attr);
125 case FAT_IOCTL_SET_ATTRIBUTES:
126 return fat_ioctl_set_attributes(filp, user_attr);
127 default:
128 return -ENOTTY;
129 }
130}
131
132static int fat_file_release(struct inode *inode, struct file *filp)
133{
134 if ((filp->f_mode & FMODE_WRITE) &&
135 MSDOS_SB(inode->i_sb)->options.flush) {
136 fat_flush_inodes(inode->i_sb, inode, NULL);
137 congestion_wait(BLK_RW_ASYNC, HZ/10);
138 }
139 return 0;
140}
141
142int fat_file_fsync(struct file *filp, struct dentry *dentry, int datasync)
143{
144 struct inode *inode = dentry->d_inode;
145 int res, err;
146
147 res = simple_fsync(filp, dentry, datasync);
148 err = sync_mapping_buffers(MSDOS_SB(inode->i_sb)->fat_inode->i_mapping);
149
150 return res ? res : err;
151}
152
153
154const struct file_operations fat_file_operations = {
155 .llseek = generic_file_llseek,
156 .read = do_sync_read,
157 .write = do_sync_write,
158 .aio_read = generic_file_aio_read,
159 .aio_write = generic_file_aio_write,
160 .mmap = generic_file_mmap,
161 .release = fat_file_release,
162 .ioctl = fat_generic_ioctl,
163 .fsync = fat_file_fsync,
164 .splice_read = generic_file_splice_read,
165};
166
167static int fat_cont_expand(struct inode *inode, loff_t size)
168{
169 struct address_space *mapping = inode->i_mapping;
170 loff_t start = inode->i_size, count = size - inode->i_size;
171 int err;
172
173 err = generic_cont_expand_simple(inode, size);
174 if (err)
175 goto out;
176
177 inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC;
178 mark_inode_dirty(inode);
179 if (IS_SYNC(inode)) {
180 int err2;
181
182
183
184
185
186 err = filemap_fdatawrite_range(mapping, start,
187 start + count - 1);
188 err2 = sync_mapping_buffers(mapping);
189 if (!err)
190 err = err2;
191 err2 = write_inode_now(inode, 1);
192 if (!err)
193 err = err2;
194 if (!err) {
195 err = filemap_fdatawait_range(mapping, start,
196 start + count - 1);
197 }
198 }
199out:
200 return err;
201}
202
203
204static 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 fat_cache_inval_inode(inode);
213
214 wait = IS_DIRSYNC(inode);
215 i_start = free_start = MSDOS_I(inode)->i_start;
216 i_logstart = MSDOS_I(inode)->i_logstart;
217
218
219 if (!skip) {
220 MSDOS_I(inode)->i_start = 0;
221 MSDOS_I(inode)->i_logstart = 0;
222 }
223 MSDOS_I(inode)->i_attrs |= ATTR_ARCH;
224 inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC;
225 if (wait) {
226 err = fat_sync_inode(inode);
227 if (err) {
228 MSDOS_I(inode)->i_start = i_start;
229 MSDOS_I(inode)->i_logstart = i_logstart;
230 return err;
231 }
232 } else
233 mark_inode_dirty(inode);
234
235
236 if (skip) {
237 struct fat_entry fatent;
238 int ret, fclus, dclus;
239
240 ret = fat_get_cluster(inode, skip - 1, &fclus, &dclus);
241 if (ret < 0)
242 return ret;
243 else if (ret == FAT_ENT_EOF)
244 return 0;
245
246 fatent_init(&fatent);
247 ret = fat_ent_read(inode, &fatent, dclus);
248 if (ret == FAT_ENT_EOF) {
249 fatent_brelse(&fatent);
250 return 0;
251 } else if (ret == FAT_ENT_FREE) {
252 fat_fs_error(sb,
253 "%s: invalid cluster chain (i_pos %lld)",
254 __func__, MSDOS_I(inode)->i_pos);
255 ret = -EIO;
256 } else if (ret > 0) {
257 err = fat_ent_write(inode, &fatent, FAT_ENT_EOF, wait);
258 if (err)
259 ret = err;
260 }
261 fatent_brelse(&fatent);
262 if (ret < 0)
263 return ret;
264
265 free_start = ret;
266 }
267 inode->i_blocks = skip << (MSDOS_SB(sb)->cluster_bits - 9);
268
269
270 return fat_free_clusters(inode, free_start);
271}
272
273void fat_truncate(struct inode *inode)
274{
275 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
276 const unsigned int cluster_size = sbi->cluster_size;
277 int nr_clusters;
278
279
280
281
282
283 if (MSDOS_I(inode)->mmu_private > inode->i_size)
284 MSDOS_I(inode)->mmu_private = inode->i_size;
285
286 nr_clusters = (inode->i_size + (cluster_size - 1)) >> sbi->cluster_bits;
287
288 fat_free(inode, nr_clusters);
289 fat_flush_inodes(inode->i_sb, inode, NULL);
290}
291
292int fat_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
293{
294 struct inode *inode = dentry->d_inode;
295 generic_fillattr(inode, stat);
296 stat->blksize = MSDOS_SB(inode->i_sb)->cluster_size;
297 return 0;
298}
299EXPORT_SYMBOL_GPL(fat_getattr);
300
301static int fat_sanitize_mode(const struct msdos_sb_info *sbi,
302 struct inode *inode, umode_t *mode_ptr)
303{
304 mode_t mask, perm;
305
306
307
308
309
310
311 if (S_ISREG(inode->i_mode))
312 mask = sbi->options.fs_fmask;
313 else
314 mask = sbi->options.fs_dmask;
315
316 perm = *mode_ptr & ~(S_IFMT | mask);
317
318
319
320
321
322
323
324 if ((perm & (S_IRUGO | S_IXUGO)) != (inode->i_mode & (S_IRUGO|S_IXUGO)))
325 return -EPERM;
326 if (fat_mode_can_hold_ro(inode)) {
327 if ((perm & S_IWUGO) && ((perm & S_IWUGO) != (S_IWUGO & ~mask)))
328 return -EPERM;
329 } else {
330 if ((perm & S_IWUGO) != (S_IWUGO & ~mask))
331 return -EPERM;
332 }
333
334 *mode_ptr &= S_IFMT | perm;
335
336 return 0;
337}
338
339static int fat_allow_set_time(struct msdos_sb_info *sbi, struct inode *inode)
340{
341 mode_t allow_utime = sbi->options.allow_utime;
342
343 if (current_fsuid() != inode->i_uid) {
344 if (in_group_p(inode->i_gid))
345 allow_utime >>= 3;
346 if (allow_utime & MAY_WRITE)
347 return 1;
348 }
349
350
351 return 0;
352}
353
354#define TIMES_SET_FLAGS (ATTR_MTIME_SET | ATTR_ATIME_SET | ATTR_TIMES_SET)
355
356#define FAT_VALID_MODE (S_IFREG | S_IFDIR | S_IRWXUGO)
357
358int fat_setattr(struct dentry *dentry, struct iattr *attr)
359{
360 struct msdos_sb_info *sbi = MSDOS_SB(dentry->d_sb);
361 struct inode *inode = dentry->d_inode;
362 unsigned int ia_valid;
363 int error;
364
365
366
367
368
369
370 if (attr->ia_valid & ATTR_SIZE) {
371 if (attr->ia_size > inode->i_size) {
372 error = fat_cont_expand(inode, attr->ia_size);
373 if (error || attr->ia_valid == ATTR_SIZE)
374 goto out;
375 attr->ia_valid &= ~ATTR_SIZE;
376 }
377 }
378
379
380 ia_valid = attr->ia_valid;
381 if (ia_valid & TIMES_SET_FLAGS) {
382 if (fat_allow_set_time(sbi, inode))
383 attr->ia_valid &= ~TIMES_SET_FLAGS;
384 }
385
386 error = inode_change_ok(inode, attr);
387 attr->ia_valid = ia_valid;
388 if (error) {
389 if (sbi->options.quiet)
390 error = 0;
391 goto out;
392 }
393
394 if (((attr->ia_valid & ATTR_UID) &&
395 (attr->ia_uid != sbi->options.fs_uid)) ||
396 ((attr->ia_valid & ATTR_GID) &&
397 (attr->ia_gid != sbi->options.fs_gid)) ||
398 ((attr->ia_valid & ATTR_MODE) &&
399 (attr->ia_mode & ~FAT_VALID_MODE)))
400 error = -EPERM;
401
402 if (error) {
403 if (sbi->options.quiet)
404 error = 0;
405 goto out;
406 }
407
408
409
410
411
412 if (attr->ia_valid & ATTR_MODE) {
413 if (fat_sanitize_mode(sbi, inode, &attr->ia_mode) < 0)
414 attr->ia_valid &= ~ATTR_MODE;
415 }
416
417 if (attr->ia_valid)
418 error = inode_setattr(inode, attr);
419out:
420 return error;
421}
422EXPORT_SYMBOL_GPL(fat_setattr);
423
424const struct inode_operations fat_file_inode_operations = {
425 .truncate = fat_truncate,
426 .setattr = fat_setattr,
427 .getattr = fat_getattr,
428};
429