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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/capability.h>
10#include <linux/module.h>
11#include <linux/compat.h>
12#include <linux/mount.h>
13#include <linux/time.h>
14#include <linux/buffer_head.h>
15#include <linux/writeback.h>
16#include <linux/backing-dev.h>
17#include <linux/blkdev.h>
18#include <linux/fsnotify.h>
19#include <linux/security.h>
20#include "fat.h"
21
22static int fat_ioctl_get_attributes(struct inode *inode, u32 __user *user_attr)
23{
24 u32 attr;
25
26 mutex_lock(&inode->i_mutex);
27 attr = fat_make_attrs(inode);
28 mutex_unlock(&inode->i_mutex);
29
30 return put_user(attr, user_attr);
31}
32
33static int fat_ioctl_set_attributes(struct file *file, u32 __user *user_attr)
34{
35 struct inode *inode = file_inode(file);
36 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
37 int is_dir = S_ISDIR(inode->i_mode);
38 u32 attr, oldattr;
39 struct iattr ia;
40 int err;
41
42 err = get_user(attr, user_attr);
43 if (err)
44 goto out;
45
46 err = mnt_want_write_file(file);
47 if (err)
48 goto out;
49 mutex_lock(&inode->i_mutex);
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_make_attrs(inode);
62
63 /* Equivalent to a chmod() */
64 ia.ia_valid = ATTR_MODE | ATTR_CTIME;
65 ia.ia_ctime = current_fs_time(inode->i_sb);
66 if (is_dir)
67 ia.ia_mode = fat_make_mode(sbi, attr, S_IRWXUGO);
68 else {
69 ia.ia_mode = fat_make_mode(sbi, attr,
70 S_IRUGO | S_IWUGO | (inode->i_mode & S_IXUGO));
71 }
72
73 /* The root directory has no attributes */
74 if (inode->i_ino == MSDOS_ROOT_INO && attr != ATTR_DIR) {
75 err = -EINVAL;
76 goto out_unlock_inode;
77 }
78
79 if (sbi->options.sys_immutable &&
80 ((attr | oldattr) & ATTR_SYS) &&
81 !capable(CAP_LINUX_IMMUTABLE)) {
82 err = -EPERM;
83 goto out_unlock_inode;
84 }
85
86 /*
87 * The security check is questionable... We single
88 * out the RO attribute for checking by the security
89 * module, just because it maps to a file mode.
90 */
91 err = security_inode_setattr(file->f_path.dentry, &ia);
92 if (err)
93 goto out_unlock_inode;
94
95 /* This MUST be done before doing anything irreversible... */
96 err = fat_setattr(file->f_path.dentry, &ia);
97 if (err)
98 goto out_unlock_inode;
99
100 fsnotify_change(file->f_path.dentry, ia.ia_valid);
101 if (sbi->options.sys_immutable) {
102 if (attr & ATTR_SYS)
103 inode->i_flags |= S_IMMUTABLE;
104 else
105 inode->i_flags &= ~S_IMMUTABLE;
106 }
107
108 fat_save_attrs(inode, attr);
109 mark_inode_dirty(inode);
110out_unlock_inode:
111 mutex_unlock(&inode->i_mutex);
112 mnt_drop_write_file(file);
113out:
114 return err;
115}
116
117static int fat_ioctl_get_volume_id(struct inode *inode, u32 __user *user_attr)
118{
119 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
120 return put_user(sbi->vol_id, user_attr);
121}
122
123long fat_generic_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
124{
125 struct inode *inode = file_inode(filp);
126 u32 __user *user_attr = (u32 __user *)arg;
127
128 switch (cmd) {
129 case FAT_IOCTL_GET_ATTRIBUTES:
130 return fat_ioctl_get_attributes(inode, user_attr);
131 case FAT_IOCTL_SET_ATTRIBUTES:
132 return fat_ioctl_set_attributes(filp, user_attr);
133 case FAT_IOCTL_GET_VOLUME_ID:
134 return fat_ioctl_get_volume_id(inode, user_attr);
135 default:
136 return -ENOTTY; /* Inappropriate ioctl for device */
137 }
138}
139
140#ifdef CONFIG_COMPAT
141static long fat_generic_compat_ioctl(struct file *filp, unsigned int cmd,
142 unsigned long arg)
143
144{
145 return fat_generic_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
146}
147#endif
148
149static int fat_file_release(struct inode *inode, struct file *filp)
150{
151 if ((filp->f_mode & FMODE_WRITE) &&
152 MSDOS_SB(inode->i_sb)->options.flush) {
153 fat_flush_inodes(inode->i_sb, inode, NULL);
154 congestion_wait(BLK_RW_ASYNC, HZ/10);
155 }
156 return 0;
157}
158
159int fat_file_fsync(struct file *filp, loff_t start, loff_t end, int datasync)
160{
161 struct inode *inode = filp->f_mapping->host;
162 int res, err;
163
164 res = generic_file_fsync(filp, start, end, datasync);
165 err = sync_mapping_buffers(MSDOS_SB(inode->i_sb)->fat_inode->i_mapping);
166
167 return res ? res : err;
168}
169
170
171const struct file_operations fat_file_operations = {
172 .llseek = generic_file_llseek,
173 .read = do_sync_read,
174 .write = do_sync_write,
175 .aio_read = generic_file_aio_read,
176 .aio_write = generic_file_aio_write,
177 .mmap = generic_file_mmap,
178 .release = fat_file_release,
179 .unlocked_ioctl = fat_generic_ioctl,
180#ifdef CONFIG_COMPAT
181 .compat_ioctl = fat_generic_compat_ioctl,
182#endif
183 .fsync = fat_file_fsync,
184 .splice_read = generic_file_splice_read,
185};
186
187static int fat_cont_expand(struct inode *inode, loff_t size)
188{
189 struct address_space *mapping = inode->i_mapping;
190 loff_t start = inode->i_size, count = size - inode->i_size;
191 int err;
192
193 err = generic_cont_expand_simple(inode, size);
194 if (err)
195 goto out;
196
197 inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC;
198 mark_inode_dirty(inode);
199 if (IS_SYNC(inode)) {
200 int err2;
201
202 /*
203 * Opencode syncing since we don't have a file open to use
204 * standard fsync path.
205 */
206 err = filemap_fdatawrite_range(mapping, start,
207 start + count - 1);
208 err2 = sync_mapping_buffers(mapping);
209 if (!err)
210 err = err2;
211 err2 = write_inode_now(inode, 1);
212 if (!err)
213 err = err2;
214 if (!err) {
215 err = filemap_fdatawait_range(mapping, start,
216 start + count - 1);
217 }
218 }
219out:
220 return err;
221}
222
223/* Free all clusters after the skip'th cluster. */
224static int fat_free(struct inode *inode, int skip)
225{
226 struct super_block *sb = inode->i_sb;
227 int err, wait, free_start, i_start, i_logstart;
228
229 if (MSDOS_I(inode)->i_start == 0)
230 return 0;
231
232 fat_cache_inval_inode(inode);
233
234 wait = IS_DIRSYNC(inode);
235 i_start = free_start = MSDOS_I(inode)->i_start;
236 i_logstart = MSDOS_I(inode)->i_logstart;
237
238 /* First, we write the new file size. */
239 if (!skip) {
240 MSDOS_I(inode)->i_start = 0;
241 MSDOS_I(inode)->i_logstart = 0;
242 }
243 MSDOS_I(inode)->i_attrs |= ATTR_ARCH;
244 inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC;
245 if (wait) {
246 err = fat_sync_inode(inode);
247 if (err) {
248 MSDOS_I(inode)->i_start = i_start;
249 MSDOS_I(inode)->i_logstart = i_logstart;
250 return err;
251 }
252 } else
253 mark_inode_dirty(inode);
254
255 /* Write a new EOF, and get the remaining cluster chain for freeing. */
256 if (skip) {
257 struct fat_entry fatent;
258 int ret, fclus, dclus;
259
260 ret = fat_get_cluster(inode, skip - 1, &fclus, &dclus);
261 if (ret < 0)
262 return ret;
263 else if (ret == FAT_ENT_EOF)
264 return 0;
265
266 fatent_init(&fatent);
267 ret = fat_ent_read(inode, &fatent, dclus);
268 if (ret == FAT_ENT_EOF) {
269 fatent_brelse(&fatent);
270 return 0;
271 } else if (ret == FAT_ENT_FREE) {
272 fat_fs_error(sb,
273 "%s: invalid cluster chain (i_pos %lld)",
274 __func__, MSDOS_I(inode)->i_pos);
275 ret = -EIO;
276 } else if (ret > 0) {
277 err = fat_ent_write(inode, &fatent, FAT_ENT_EOF, wait);
278 if (err)
279 ret = err;
280 }
281 fatent_brelse(&fatent);
282 if (ret < 0)
283 return ret;
284
285 free_start = ret;
286 }
287 inode->i_blocks = skip << (MSDOS_SB(sb)->cluster_bits - 9);
288
289 /* Freeing the remained cluster chain */
290 return fat_free_clusters(inode, free_start);
291}
292
293void fat_truncate_blocks(struct inode *inode, loff_t offset)
294{
295 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
296 const unsigned int cluster_size = sbi->cluster_size;
297 int nr_clusters;
298
299 /*
300 * This protects against truncating a file bigger than it was then
301 * trying to write into the hole.
302 */
303 if (MSDOS_I(inode)->mmu_private > offset)
304 MSDOS_I(inode)->mmu_private = offset;
305
306 nr_clusters = (offset + (cluster_size - 1)) >> sbi->cluster_bits;
307
308 fat_free(inode, nr_clusters);
309 fat_flush_inodes(inode->i_sb, inode, NULL);
310}
311
312int fat_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
313{
314 struct inode *inode = dentry->d_inode;
315 generic_fillattr(inode, stat);
316 stat->blksize = MSDOS_SB(inode->i_sb)->cluster_size;
317
318 if (MSDOS_SB(inode->i_sb)->options.nfs == FAT_NFS_NOSTALE_RO) {
319 /* Use i_pos for ino. This is used as fileid of nfs. */
320 stat->ino = fat_i_pos_read(MSDOS_SB(inode->i_sb), inode);
321 }
322 return 0;
323}
324EXPORT_SYMBOL_GPL(fat_getattr);
325
326static int fat_sanitize_mode(const struct msdos_sb_info *sbi,
327 struct inode *inode, umode_t *mode_ptr)
328{
329 umode_t mask, perm;
330
331 /*
332 * Note, the basic check is already done by a caller of
333 * (attr->ia_mode & ~FAT_VALID_MODE)
334 */
335
336 if (S_ISREG(inode->i_mode))
337 mask = sbi->options.fs_fmask;
338 else
339 mask = sbi->options.fs_dmask;
340
341 perm = *mode_ptr & ~(S_IFMT | mask);
342
343 /*
344 * Of the r and x bits, all (subject to umask) must be present. Of the
345 * w bits, either all (subject to umask) or none must be present.
346 *
347 * If fat_mode_can_hold_ro(inode) is false, can't change w bits.
348 */
349 if ((perm & (S_IRUGO | S_IXUGO)) != (inode->i_mode & (S_IRUGO|S_IXUGO)))
350 return -EPERM;
351 if (fat_mode_can_hold_ro(inode)) {
352 if ((perm & S_IWUGO) && ((perm & S_IWUGO) != (S_IWUGO & ~mask)))
353 return -EPERM;
354 } else {
355 if ((perm & S_IWUGO) != (S_IWUGO & ~mask))
356 return -EPERM;
357 }
358
359 *mode_ptr &= S_IFMT | perm;
360
361 return 0;
362}
363
364static int fat_allow_set_time(struct msdos_sb_info *sbi, struct inode *inode)
365{
366 umode_t allow_utime = sbi->options.allow_utime;
367
368 if (!uid_eq(current_fsuid(), inode->i_uid)) {
369 if (in_group_p(inode->i_gid))
370 allow_utime >>= 3;
371 if (allow_utime & MAY_WRITE)
372 return 1;
373 }
374
375 /* use a default check */
376 return 0;
377}
378
379#define TIMES_SET_FLAGS (ATTR_MTIME_SET | ATTR_ATIME_SET | ATTR_TIMES_SET)
380/* valid file mode bits */
381#define FAT_VALID_MODE (S_IFREG | S_IFDIR | S_IRWXUGO)
382
383int fat_setattr(struct dentry *dentry, struct iattr *attr)
384{
385 struct msdos_sb_info *sbi = MSDOS_SB(dentry->d_sb);
386 struct inode *inode = dentry->d_inode;
387 unsigned int ia_valid;
388 int error;
389
390 /* Check for setting the inode time. */
391 ia_valid = attr->ia_valid;
392 if (ia_valid & TIMES_SET_FLAGS) {
393 if (fat_allow_set_time(sbi, inode))
394 attr->ia_valid &= ~TIMES_SET_FLAGS;
395 }
396
397 error = inode_change_ok(inode, attr);
398 attr->ia_valid = ia_valid;
399 if (error) {
400 if (sbi->options.quiet)
401 error = 0;
402 goto out;
403 }
404
405 /*
406 * Expand the file. Since inode_setattr() updates ->i_size
407 * before calling the ->truncate(), but FAT needs to fill the
408 * hole before it. XXX: this is no longer true with new truncate
409 * sequence.
410 */
411 if (attr->ia_valid & ATTR_SIZE) {
412 inode_dio_wait(inode);
413
414 if (attr->ia_size > inode->i_size) {
415 error = fat_cont_expand(inode, attr->ia_size);
416 if (error || attr->ia_valid == ATTR_SIZE)
417 goto out;
418 attr->ia_valid &= ~ATTR_SIZE;
419 }
420 }
421
422 if (((attr->ia_valid & ATTR_UID) &&
423 (!uid_eq(attr->ia_uid, sbi->options.fs_uid))) ||
424 ((attr->ia_valid & ATTR_GID) &&
425 (!gid_eq(attr->ia_gid, sbi->options.fs_gid))) ||
426 ((attr->ia_valid & ATTR_MODE) &&
427 (attr->ia_mode & ~FAT_VALID_MODE)))
428 error = -EPERM;
429
430 if (error) {
431 if (sbi->options.quiet)
432 error = 0;
433 goto out;
434 }
435
436 /*
437 * We don't return -EPERM here. Yes, strange, but this is too
438 * old behavior.
439 */
440 if (attr->ia_valid & ATTR_MODE) {
441 if (fat_sanitize_mode(sbi, inode, &attr->ia_mode) < 0)
442 attr->ia_valid &= ~ATTR_MODE;
443 }
444
445 if (attr->ia_valid & ATTR_SIZE) {
446 down_write(&MSDOS_I(inode)->truncate_lock);
447 truncate_setsize(inode, attr->ia_size);
448 fat_truncate_blocks(inode, attr->ia_size);
449 up_write(&MSDOS_I(inode)->truncate_lock);
450 }
451
452 setattr_copy(inode, attr);
453 mark_inode_dirty(inode);
454out:
455 return error;
456}
457EXPORT_SYMBOL_GPL(fat_setattr);
458
459const struct inode_operations fat_file_inode_operations = {
460 .setattr = fat_setattr,
461 .getattr = fat_getattr,
462};
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/capability.h>
10#include <linux/module.h>
11#include <linux/compat.h>
12#include <linux/mount.h>
13#include <linux/time.h>
14#include <linux/buffer_head.h>
15#include <linux/writeback.h>
16#include <linux/backing-dev.h>
17#include <linux/blkdev.h>
18#include <linux/fsnotify.h>
19#include <linux/security.h>
20#include "fat.h"
21
22static int fat_ioctl_get_attributes(struct inode *inode, u32 __user *user_attr)
23{
24 u32 attr;
25
26 mutex_lock(&inode->i_mutex);
27 attr = fat_make_attrs(inode);
28 mutex_unlock(&inode->i_mutex);
29
30 return put_user(attr, user_attr);
31}
32
33static int fat_ioctl_set_attributes(struct file *file, u32 __user *user_attr)
34{
35 struct inode *inode = file->f_path.dentry->d_inode;
36 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
37 int is_dir = S_ISDIR(inode->i_mode);
38 u32 attr, oldattr;
39 struct iattr ia;
40 int err;
41
42 err = get_user(attr, user_attr);
43 if (err)
44 goto out;
45
46 mutex_lock(&inode->i_mutex);
47 err = mnt_want_write(file->f_path.mnt);
48 if (err)
49 goto out_unlock_inode;
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_make_attrs(inode);
62
63 /* Equivalent to a chmod() */
64 ia.ia_valid = ATTR_MODE | ATTR_CTIME;
65 ia.ia_ctime = current_fs_time(inode->i_sb);
66 if (is_dir)
67 ia.ia_mode = fat_make_mode(sbi, attr, S_IRWXUGO);
68 else {
69 ia.ia_mode = fat_make_mode(sbi, attr,
70 S_IRUGO | S_IWUGO | (inode->i_mode & S_IXUGO));
71 }
72
73 /* The root directory has no attributes */
74 if (inode->i_ino == MSDOS_ROOT_INO && attr != ATTR_DIR) {
75 err = -EINVAL;
76 goto out_drop_write;
77 }
78
79 if (sbi->options.sys_immutable &&
80 ((attr | oldattr) & ATTR_SYS) &&
81 !capable(CAP_LINUX_IMMUTABLE)) {
82 err = -EPERM;
83 goto out_drop_write;
84 }
85
86 /*
87 * The security check is questionable... We single
88 * out the RO attribute for checking by the security
89 * module, just because it maps to a file mode.
90 */
91 err = security_inode_setattr(file->f_path.dentry, &ia);
92 if (err)
93 goto out_drop_write;
94
95 /* This MUST be done before doing anything irreversible... */
96 err = fat_setattr(file->f_path.dentry, &ia);
97 if (err)
98 goto out_drop_write;
99
100 fsnotify_change(file->f_path.dentry, ia.ia_valid);
101 if (sbi->options.sys_immutable) {
102 if (attr & ATTR_SYS)
103 inode->i_flags |= S_IMMUTABLE;
104 else
105 inode->i_flags &= ~S_IMMUTABLE;
106 }
107
108 fat_save_attrs(inode, attr);
109 mark_inode_dirty(inode);
110out_drop_write:
111 mnt_drop_write(file->f_path.mnt);
112out_unlock_inode:
113 mutex_unlock(&inode->i_mutex);
114out:
115 return err;
116}
117
118long fat_generic_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
119{
120 struct inode *inode = filp->f_path.dentry->d_inode;
121 u32 __user *user_attr = (u32 __user *)arg;
122
123 switch (cmd) {
124 case FAT_IOCTL_GET_ATTRIBUTES:
125 return fat_ioctl_get_attributes(inode, user_attr);
126 case FAT_IOCTL_SET_ATTRIBUTES:
127 return fat_ioctl_set_attributes(filp, user_attr);
128 default:
129 return -ENOTTY; /* Inappropriate ioctl for device */
130 }
131}
132
133#ifdef CONFIG_COMPAT
134static long fat_generic_compat_ioctl(struct file *filp, unsigned int cmd,
135 unsigned long arg)
136
137{
138 return fat_generic_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
139}
140#endif
141
142static int fat_file_release(struct inode *inode, struct file *filp)
143{
144 if ((filp->f_mode & FMODE_WRITE) &&
145 MSDOS_SB(inode->i_sb)->options.flush) {
146 fat_flush_inodes(inode->i_sb, inode, NULL);
147 congestion_wait(BLK_RW_ASYNC, HZ/10);
148 }
149 return 0;
150}
151
152int fat_file_fsync(struct file *filp, loff_t start, loff_t end, int datasync)
153{
154 struct inode *inode = filp->f_mapping->host;
155 int res, err;
156
157 res = generic_file_fsync(filp, start, end, datasync);
158 err = sync_mapping_buffers(MSDOS_SB(inode->i_sb)->fat_inode->i_mapping);
159
160 return res ? res : err;
161}
162
163
164const struct file_operations fat_file_operations = {
165 .llseek = generic_file_llseek,
166 .read = do_sync_read,
167 .write = do_sync_write,
168 .aio_read = generic_file_aio_read,
169 .aio_write = generic_file_aio_write,
170 .mmap = generic_file_mmap,
171 .release = fat_file_release,
172 .unlocked_ioctl = fat_generic_ioctl,
173#ifdef CONFIG_COMPAT
174 .compat_ioctl = fat_generic_compat_ioctl,
175#endif
176 .fsync = fat_file_fsync,
177 .splice_read = generic_file_splice_read,
178};
179
180static int fat_cont_expand(struct inode *inode, loff_t size)
181{
182 struct address_space *mapping = inode->i_mapping;
183 loff_t start = inode->i_size, count = size - inode->i_size;
184 int err;
185
186 err = generic_cont_expand_simple(inode, size);
187 if (err)
188 goto out;
189
190 inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC;
191 mark_inode_dirty(inode);
192 if (IS_SYNC(inode)) {
193 int err2;
194
195 /*
196 * Opencode syncing since we don't have a file open to use
197 * standard fsync path.
198 */
199 err = filemap_fdatawrite_range(mapping, start,
200 start + count - 1);
201 err2 = sync_mapping_buffers(mapping);
202 if (!err)
203 err = err2;
204 err2 = write_inode_now(inode, 1);
205 if (!err)
206 err = err2;
207 if (!err) {
208 err = filemap_fdatawait_range(mapping, start,
209 start + count - 1);
210 }
211 }
212out:
213 return err;
214}
215
216/* Free all clusters after the skip'th cluster. */
217static int fat_free(struct inode *inode, int skip)
218{
219 struct super_block *sb = inode->i_sb;
220 int err, wait, free_start, i_start, i_logstart;
221
222 if (MSDOS_I(inode)->i_start == 0)
223 return 0;
224
225 fat_cache_inval_inode(inode);
226
227 wait = IS_DIRSYNC(inode);
228 i_start = free_start = MSDOS_I(inode)->i_start;
229 i_logstart = MSDOS_I(inode)->i_logstart;
230
231 /* First, we write the new file size. */
232 if (!skip) {
233 MSDOS_I(inode)->i_start = 0;
234 MSDOS_I(inode)->i_logstart = 0;
235 }
236 MSDOS_I(inode)->i_attrs |= ATTR_ARCH;
237 inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC;
238 if (wait) {
239 err = fat_sync_inode(inode);
240 if (err) {
241 MSDOS_I(inode)->i_start = i_start;
242 MSDOS_I(inode)->i_logstart = i_logstart;
243 return err;
244 }
245 } else
246 mark_inode_dirty(inode);
247
248 /* Write a new EOF, and get the remaining cluster chain for freeing. */
249 if (skip) {
250 struct fat_entry fatent;
251 int ret, fclus, dclus;
252
253 ret = fat_get_cluster(inode, skip - 1, &fclus, &dclus);
254 if (ret < 0)
255 return ret;
256 else if (ret == FAT_ENT_EOF)
257 return 0;
258
259 fatent_init(&fatent);
260 ret = fat_ent_read(inode, &fatent, dclus);
261 if (ret == FAT_ENT_EOF) {
262 fatent_brelse(&fatent);
263 return 0;
264 } else if (ret == FAT_ENT_FREE) {
265 fat_fs_error(sb,
266 "%s: invalid cluster chain (i_pos %lld)",
267 __func__, MSDOS_I(inode)->i_pos);
268 ret = -EIO;
269 } else if (ret > 0) {
270 err = fat_ent_write(inode, &fatent, FAT_ENT_EOF, wait);
271 if (err)
272 ret = err;
273 }
274 fatent_brelse(&fatent);
275 if (ret < 0)
276 return ret;
277
278 free_start = ret;
279 }
280 inode->i_blocks = skip << (MSDOS_SB(sb)->cluster_bits - 9);
281
282 /* Freeing the remained cluster chain */
283 return fat_free_clusters(inode, free_start);
284}
285
286void fat_truncate_blocks(struct inode *inode, loff_t offset)
287{
288 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
289 const unsigned int cluster_size = sbi->cluster_size;
290 int nr_clusters;
291
292 /*
293 * This protects against truncating a file bigger than it was then
294 * trying to write into the hole.
295 */
296 if (MSDOS_I(inode)->mmu_private > offset)
297 MSDOS_I(inode)->mmu_private = offset;
298
299 nr_clusters = (offset + (cluster_size - 1)) >> sbi->cluster_bits;
300
301 fat_free(inode, nr_clusters);
302 fat_flush_inodes(inode->i_sb, inode, NULL);
303}
304
305int fat_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
306{
307 struct inode *inode = dentry->d_inode;
308 generic_fillattr(inode, stat);
309 stat->blksize = MSDOS_SB(inode->i_sb)->cluster_size;
310 return 0;
311}
312EXPORT_SYMBOL_GPL(fat_getattr);
313
314static int fat_sanitize_mode(const struct msdos_sb_info *sbi,
315 struct inode *inode, umode_t *mode_ptr)
316{
317 mode_t mask, perm;
318
319 /*
320 * Note, the basic check is already done by a caller of
321 * (attr->ia_mode & ~FAT_VALID_MODE)
322 */
323
324 if (S_ISREG(inode->i_mode))
325 mask = sbi->options.fs_fmask;
326 else
327 mask = sbi->options.fs_dmask;
328
329 perm = *mode_ptr & ~(S_IFMT | mask);
330
331 /*
332 * Of the r and x bits, all (subject to umask) must be present. Of the
333 * w bits, either all (subject to umask) or none must be present.
334 *
335 * If fat_mode_can_hold_ro(inode) is false, can't change w bits.
336 */
337 if ((perm & (S_IRUGO | S_IXUGO)) != (inode->i_mode & (S_IRUGO|S_IXUGO)))
338 return -EPERM;
339 if (fat_mode_can_hold_ro(inode)) {
340 if ((perm & S_IWUGO) && ((perm & S_IWUGO) != (S_IWUGO & ~mask)))
341 return -EPERM;
342 } else {
343 if ((perm & S_IWUGO) != (S_IWUGO & ~mask))
344 return -EPERM;
345 }
346
347 *mode_ptr &= S_IFMT | perm;
348
349 return 0;
350}
351
352static int fat_allow_set_time(struct msdos_sb_info *sbi, struct inode *inode)
353{
354 mode_t allow_utime = sbi->options.allow_utime;
355
356 if (current_fsuid() != inode->i_uid) {
357 if (in_group_p(inode->i_gid))
358 allow_utime >>= 3;
359 if (allow_utime & MAY_WRITE)
360 return 1;
361 }
362
363 /* use a default check */
364 return 0;
365}
366
367#define TIMES_SET_FLAGS (ATTR_MTIME_SET | ATTR_ATIME_SET | ATTR_TIMES_SET)
368/* valid file mode bits */
369#define FAT_VALID_MODE (S_IFREG | S_IFDIR | S_IRWXUGO)
370
371int fat_setattr(struct dentry *dentry, struct iattr *attr)
372{
373 struct msdos_sb_info *sbi = MSDOS_SB(dentry->d_sb);
374 struct inode *inode = dentry->d_inode;
375 unsigned int ia_valid;
376 int error;
377
378 /* Check for setting the inode time. */
379 ia_valid = attr->ia_valid;
380 if (ia_valid & TIMES_SET_FLAGS) {
381 if (fat_allow_set_time(sbi, inode))
382 attr->ia_valid &= ~TIMES_SET_FLAGS;
383 }
384
385 error = inode_change_ok(inode, attr);
386 attr->ia_valid = ia_valid;
387 if (error) {
388 if (sbi->options.quiet)
389 error = 0;
390 goto out;
391 }
392
393 /*
394 * Expand the file. Since inode_setattr() updates ->i_size
395 * before calling the ->truncate(), but FAT needs to fill the
396 * hole before it. XXX: this is no longer true with new truncate
397 * sequence.
398 */
399 if (attr->ia_valid & ATTR_SIZE) {
400 inode_dio_wait(inode);
401
402 if (attr->ia_size > inode->i_size) {
403 error = fat_cont_expand(inode, attr->ia_size);
404 if (error || attr->ia_valid == ATTR_SIZE)
405 goto out;
406 attr->ia_valid &= ~ATTR_SIZE;
407 }
408 }
409
410 if (((attr->ia_valid & ATTR_UID) &&
411 (attr->ia_uid != sbi->options.fs_uid)) ||
412 ((attr->ia_valid & ATTR_GID) &&
413 (attr->ia_gid != sbi->options.fs_gid)) ||
414 ((attr->ia_valid & ATTR_MODE) &&
415 (attr->ia_mode & ~FAT_VALID_MODE)))
416 error = -EPERM;
417
418 if (error) {
419 if (sbi->options.quiet)
420 error = 0;
421 goto out;
422 }
423
424 /*
425 * We don't return -EPERM here. Yes, strange, but this is too
426 * old behavior.
427 */
428 if (attr->ia_valid & ATTR_MODE) {
429 if (fat_sanitize_mode(sbi, inode, &attr->ia_mode) < 0)
430 attr->ia_valid &= ~ATTR_MODE;
431 }
432
433 if (attr->ia_valid & ATTR_SIZE) {
434 down_write(&MSDOS_I(inode)->truncate_lock);
435 truncate_setsize(inode, attr->ia_size);
436 fat_truncate_blocks(inode, attr->ia_size);
437 up_write(&MSDOS_I(inode)->truncate_lock);
438 }
439
440 setattr_copy(inode, attr);
441 mark_inode_dirty(inode);
442out:
443 return error;
444}
445EXPORT_SYMBOL_GPL(fat_setattr);
446
447const struct inode_operations fat_file_inode_operations = {
448 .setattr = fat_setattr,
449 .getattr = fat_getattr,
450};