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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/blkdev.h>
14#include <linux/backing-dev.h>
15#include <linux/fsnotify.h>
16#include <linux/security.h>
17#include <linux/falloc.h>
18#include "fat.h"
19
20static long fat_fallocate(struct file *file, int mode,
21 loff_t offset, loff_t len);
22
23static int fat_ioctl_get_attributes(struct inode *inode, u32 __user *user_attr)
24{
25 u32 attr;
26
27 inode_lock(inode);
28 attr = fat_make_attrs(inode);
29 inode_unlock(inode);
30
31 return put_user(attr, user_attr);
32}
33
34static int fat_ioctl_set_attributes(struct file *file, u32 __user *user_attr)
35{
36 struct inode *inode = file_inode(file);
37 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
38 int is_dir = S_ISDIR(inode->i_mode);
39 u32 attr, oldattr;
40 struct iattr ia;
41 int err;
42
43 err = get_user(attr, user_attr);
44 if (err)
45 goto out;
46
47 err = mnt_want_write_file(file);
48 if (err)
49 goto out;
50 inode_lock(inode);
51
52 /*
53 * ATTR_VOLUME and ATTR_DIR cannot be changed; this also
54 * prevents the user from turning us into a VFAT
55 * longname entry. Also, we obviously can't set
56 * any of the NTFS attributes in the high 24 bits.
57 */
58 attr &= 0xff & ~(ATTR_VOLUME | ATTR_DIR);
59 /* Merge in ATTR_VOLUME and ATTR_DIR */
60 attr |= (MSDOS_I(inode)->i_attrs & ATTR_VOLUME) |
61 (is_dir ? ATTR_DIR : 0);
62 oldattr = fat_make_attrs(inode);
63
64 /* Equivalent to a chmod() */
65 ia.ia_valid = ATTR_MODE | ATTR_CTIME;
66 ia.ia_ctime = current_fs_time(inode->i_sb);
67 if (is_dir)
68 ia.ia_mode = fat_make_mode(sbi, attr, S_IRWXUGO);
69 else {
70 ia.ia_mode = fat_make_mode(sbi, attr,
71 S_IRUGO | S_IWUGO | (inode->i_mode & S_IXUGO));
72 }
73
74 /* The root directory has no attributes */
75 if (inode->i_ino == MSDOS_ROOT_INO && attr != ATTR_DIR) {
76 err = -EINVAL;
77 goto out_unlock_inode;
78 }
79
80 if (sbi->options.sys_immutable &&
81 ((attr | oldattr) & ATTR_SYS) &&
82 !capable(CAP_LINUX_IMMUTABLE)) {
83 err = -EPERM;
84 goto out_unlock_inode;
85 }
86
87 /*
88 * The security check is questionable... We single
89 * out the RO attribute for checking by the security
90 * module, just because it maps to a file mode.
91 */
92 err = security_inode_setattr(file->f_path.dentry, &ia);
93 if (err)
94 goto out_unlock_inode;
95
96 /* This MUST be done before doing anything irreversible... */
97 err = fat_setattr(file->f_path.dentry, &ia);
98 if (err)
99 goto out_unlock_inode;
100
101 fsnotify_change(file->f_path.dentry, ia.ia_valid);
102 if (sbi->options.sys_immutable) {
103 if (attr & ATTR_SYS)
104 inode->i_flags |= S_IMMUTABLE;
105 else
106 inode->i_flags &= ~S_IMMUTABLE;
107 }
108
109 fat_save_attrs(inode, attr);
110 mark_inode_dirty(inode);
111out_unlock_inode:
112 inode_unlock(inode);
113 mnt_drop_write_file(file);
114out:
115 return err;
116}
117
118static int fat_ioctl_get_volume_id(struct inode *inode, u32 __user *user_attr)
119{
120 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
121 return put_user(sbi->vol_id, user_attr);
122}
123
124long fat_generic_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
125{
126 struct inode *inode = file_inode(filp);
127 u32 __user *user_attr = (u32 __user *)arg;
128
129 switch (cmd) {
130 case FAT_IOCTL_GET_ATTRIBUTES:
131 return fat_ioctl_get_attributes(inode, user_attr);
132 case FAT_IOCTL_SET_ATTRIBUTES:
133 return fat_ioctl_set_attributes(filp, user_attr);
134 case FAT_IOCTL_GET_VOLUME_ID:
135 return fat_ioctl_get_volume_id(inode, user_attr);
136 default:
137 return -ENOTTY; /* Inappropriate ioctl for device */
138 }
139}
140
141#ifdef CONFIG_COMPAT
142static long fat_generic_compat_ioctl(struct file *filp, unsigned int cmd,
143 unsigned long arg)
144
145{
146 return fat_generic_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
147}
148#endif
149
150static int fat_file_release(struct inode *inode, struct file *filp)
151{
152 if ((filp->f_mode & FMODE_WRITE) &&
153 MSDOS_SB(inode->i_sb)->options.flush) {
154 fat_flush_inodes(inode->i_sb, inode, NULL);
155 congestion_wait(BLK_RW_ASYNC, HZ/10);
156 }
157 return 0;
158}
159
160int fat_file_fsync(struct file *filp, loff_t start, loff_t end, int datasync)
161{
162 struct inode *inode = filp->f_mapping->host;
163 int res, err;
164
165 res = generic_file_fsync(filp, start, end, datasync);
166 err = sync_mapping_buffers(MSDOS_SB(inode->i_sb)->fat_inode->i_mapping);
167
168 return res ? res : err;
169}
170
171
172const struct file_operations fat_file_operations = {
173 .llseek = generic_file_llseek,
174 .read_iter = generic_file_read_iter,
175 .write_iter = generic_file_write_iter,
176 .mmap = generic_file_mmap,
177 .release = fat_file_release,
178 .unlocked_ioctl = fat_generic_ioctl,
179#ifdef CONFIG_COMPAT
180 .compat_ioctl = fat_generic_compat_ioctl,
181#endif
182 .fsync = fat_file_fsync,
183 .splice_read = generic_file_splice_read,
184 .fallocate = fat_fallocate,
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/*
224 * Preallocate space for a file. This implements fat's fallocate file
225 * operation, which gets called from sys_fallocate system call. User
226 * space requests len bytes at offset. If FALLOC_FL_KEEP_SIZE is set
227 * we just allocate clusters without zeroing them out. Otherwise we
228 * allocate and zero out clusters via an expanding truncate.
229 */
230static long fat_fallocate(struct file *file, int mode,
231 loff_t offset, loff_t len)
232{
233 int nr_cluster; /* Number of clusters to be allocated */
234 loff_t mm_bytes; /* Number of bytes to be allocated for file */
235 loff_t ondisksize; /* block aligned on-disk size in bytes*/
236 struct inode *inode = file->f_mapping->host;
237 struct super_block *sb = inode->i_sb;
238 struct msdos_sb_info *sbi = MSDOS_SB(sb);
239 int err = 0;
240
241 /* No support for hole punch or other fallocate flags. */
242 if (mode & ~FALLOC_FL_KEEP_SIZE)
243 return -EOPNOTSUPP;
244
245 /* No support for dir */
246 if (!S_ISREG(inode->i_mode))
247 return -EOPNOTSUPP;
248
249 inode_lock(inode);
250 if (mode & FALLOC_FL_KEEP_SIZE) {
251 ondisksize = inode->i_blocks << 9;
252 if ((offset + len) <= ondisksize)
253 goto error;
254
255 /* First compute the number of clusters to be allocated */
256 mm_bytes = offset + len - ondisksize;
257 nr_cluster = (mm_bytes + (sbi->cluster_size - 1)) >>
258 sbi->cluster_bits;
259
260 /* Start the allocation.We are not zeroing out the clusters */
261 while (nr_cluster-- > 0) {
262 err = fat_add_cluster(inode);
263 if (err)
264 goto error;
265 }
266 } else {
267 if ((offset + len) <= i_size_read(inode))
268 goto error;
269
270 /* This is just an expanding truncate */
271 err = fat_cont_expand(inode, (offset + len));
272 }
273
274error:
275 inode_unlock(inode);
276 return err;
277}
278
279/* Free all clusters after the skip'th cluster. */
280static int fat_free(struct inode *inode, int skip)
281{
282 struct super_block *sb = inode->i_sb;
283 int err, wait, free_start, i_start, i_logstart;
284
285 if (MSDOS_I(inode)->i_start == 0)
286 return 0;
287
288 fat_cache_inval_inode(inode);
289
290 wait = IS_DIRSYNC(inode);
291 i_start = free_start = MSDOS_I(inode)->i_start;
292 i_logstart = MSDOS_I(inode)->i_logstart;
293
294 /* First, we write the new file size. */
295 if (!skip) {
296 MSDOS_I(inode)->i_start = 0;
297 MSDOS_I(inode)->i_logstart = 0;
298 }
299 MSDOS_I(inode)->i_attrs |= ATTR_ARCH;
300 inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC;
301 if (wait) {
302 err = fat_sync_inode(inode);
303 if (err) {
304 MSDOS_I(inode)->i_start = i_start;
305 MSDOS_I(inode)->i_logstart = i_logstart;
306 return err;
307 }
308 } else
309 mark_inode_dirty(inode);
310
311 /* Write a new EOF, and get the remaining cluster chain for freeing. */
312 if (skip) {
313 struct fat_entry fatent;
314 int ret, fclus, dclus;
315
316 ret = fat_get_cluster(inode, skip - 1, &fclus, &dclus);
317 if (ret < 0)
318 return ret;
319 else if (ret == FAT_ENT_EOF)
320 return 0;
321
322 fatent_init(&fatent);
323 ret = fat_ent_read(inode, &fatent, dclus);
324 if (ret == FAT_ENT_EOF) {
325 fatent_brelse(&fatent);
326 return 0;
327 } else if (ret == FAT_ENT_FREE) {
328 fat_fs_error(sb,
329 "%s: invalid cluster chain (i_pos %lld)",
330 __func__, MSDOS_I(inode)->i_pos);
331 ret = -EIO;
332 } else if (ret > 0) {
333 err = fat_ent_write(inode, &fatent, FAT_ENT_EOF, wait);
334 if (err)
335 ret = err;
336 }
337 fatent_brelse(&fatent);
338 if (ret < 0)
339 return ret;
340
341 free_start = ret;
342 }
343 inode->i_blocks = skip << (MSDOS_SB(sb)->cluster_bits - 9);
344
345 /* Freeing the remained cluster chain */
346 return fat_free_clusters(inode, free_start);
347}
348
349void fat_truncate_blocks(struct inode *inode, loff_t offset)
350{
351 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
352 const unsigned int cluster_size = sbi->cluster_size;
353 int nr_clusters;
354
355 /*
356 * This protects against truncating a file bigger than it was then
357 * trying to write into the hole.
358 */
359 if (MSDOS_I(inode)->mmu_private > offset)
360 MSDOS_I(inode)->mmu_private = offset;
361
362 nr_clusters = (offset + (cluster_size - 1)) >> sbi->cluster_bits;
363
364 fat_free(inode, nr_clusters);
365 fat_flush_inodes(inode->i_sb, inode, NULL);
366}
367
368int fat_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
369{
370 struct inode *inode = d_inode(dentry);
371 generic_fillattr(inode, stat);
372 stat->blksize = MSDOS_SB(inode->i_sb)->cluster_size;
373
374 if (MSDOS_SB(inode->i_sb)->options.nfs == FAT_NFS_NOSTALE_RO) {
375 /* Use i_pos for ino. This is used as fileid of nfs. */
376 stat->ino = fat_i_pos_read(MSDOS_SB(inode->i_sb), inode);
377 }
378 return 0;
379}
380EXPORT_SYMBOL_GPL(fat_getattr);
381
382static int fat_sanitize_mode(const struct msdos_sb_info *sbi,
383 struct inode *inode, umode_t *mode_ptr)
384{
385 umode_t mask, perm;
386
387 /*
388 * Note, the basic check is already done by a caller of
389 * (attr->ia_mode & ~FAT_VALID_MODE)
390 */
391
392 if (S_ISREG(inode->i_mode))
393 mask = sbi->options.fs_fmask;
394 else
395 mask = sbi->options.fs_dmask;
396
397 perm = *mode_ptr & ~(S_IFMT | mask);
398
399 /*
400 * Of the r and x bits, all (subject to umask) must be present. Of the
401 * w bits, either all (subject to umask) or none must be present.
402 *
403 * If fat_mode_can_hold_ro(inode) is false, can't change w bits.
404 */
405 if ((perm & (S_IRUGO | S_IXUGO)) != (inode->i_mode & (S_IRUGO|S_IXUGO)))
406 return -EPERM;
407 if (fat_mode_can_hold_ro(inode)) {
408 if ((perm & S_IWUGO) && ((perm & S_IWUGO) != (S_IWUGO & ~mask)))
409 return -EPERM;
410 } else {
411 if ((perm & S_IWUGO) != (S_IWUGO & ~mask))
412 return -EPERM;
413 }
414
415 *mode_ptr &= S_IFMT | perm;
416
417 return 0;
418}
419
420static int fat_allow_set_time(struct msdos_sb_info *sbi, struct inode *inode)
421{
422 umode_t allow_utime = sbi->options.allow_utime;
423
424 if (!uid_eq(current_fsuid(), inode->i_uid)) {
425 if (in_group_p(inode->i_gid))
426 allow_utime >>= 3;
427 if (allow_utime & MAY_WRITE)
428 return 1;
429 }
430
431 /* use a default check */
432 return 0;
433}
434
435#define TIMES_SET_FLAGS (ATTR_MTIME_SET | ATTR_ATIME_SET | ATTR_TIMES_SET)
436/* valid file mode bits */
437#define FAT_VALID_MODE (S_IFREG | S_IFDIR | S_IRWXUGO)
438
439int fat_setattr(struct dentry *dentry, struct iattr *attr)
440{
441 struct msdos_sb_info *sbi = MSDOS_SB(dentry->d_sb);
442 struct inode *inode = d_inode(dentry);
443 unsigned int ia_valid;
444 int error;
445
446 /* Check for setting the inode time. */
447 ia_valid = attr->ia_valid;
448 if (ia_valid & TIMES_SET_FLAGS) {
449 if (fat_allow_set_time(sbi, inode))
450 attr->ia_valid &= ~TIMES_SET_FLAGS;
451 }
452
453 error = inode_change_ok(inode, attr);
454 attr->ia_valid = ia_valid;
455 if (error) {
456 if (sbi->options.quiet)
457 error = 0;
458 goto out;
459 }
460
461 /*
462 * Expand the file. Since inode_setattr() updates ->i_size
463 * before calling the ->truncate(), but FAT needs to fill the
464 * hole before it. XXX: this is no longer true with new truncate
465 * sequence.
466 */
467 if (attr->ia_valid & ATTR_SIZE) {
468 inode_dio_wait(inode);
469
470 if (attr->ia_size > inode->i_size) {
471 error = fat_cont_expand(inode, attr->ia_size);
472 if (error || attr->ia_valid == ATTR_SIZE)
473 goto out;
474 attr->ia_valid &= ~ATTR_SIZE;
475 }
476 }
477
478 if (((attr->ia_valid & ATTR_UID) &&
479 (!uid_eq(attr->ia_uid, sbi->options.fs_uid))) ||
480 ((attr->ia_valid & ATTR_GID) &&
481 (!gid_eq(attr->ia_gid, sbi->options.fs_gid))) ||
482 ((attr->ia_valid & ATTR_MODE) &&
483 (attr->ia_mode & ~FAT_VALID_MODE)))
484 error = -EPERM;
485
486 if (error) {
487 if (sbi->options.quiet)
488 error = 0;
489 goto out;
490 }
491
492 /*
493 * We don't return -EPERM here. Yes, strange, but this is too
494 * old behavior.
495 */
496 if (attr->ia_valid & ATTR_MODE) {
497 if (fat_sanitize_mode(sbi, inode, &attr->ia_mode) < 0)
498 attr->ia_valid &= ~ATTR_MODE;
499 }
500
501 if (attr->ia_valid & ATTR_SIZE) {
502 error = fat_block_truncate_page(inode, attr->ia_size);
503 if (error)
504 goto out;
505 down_write(&MSDOS_I(inode)->truncate_lock);
506 truncate_setsize(inode, attr->ia_size);
507 fat_truncate_blocks(inode, attr->ia_size);
508 up_write(&MSDOS_I(inode)->truncate_lock);
509 }
510
511 setattr_copy(inode, attr);
512 mark_inode_dirty(inode);
513out:
514 return error;
515}
516EXPORT_SYMBOL_GPL(fat_setattr);
517
518const struct inode_operations fat_file_inode_operations = {
519 .setattr = fat_setattr,
520 .getattr = fat_getattr,
521};
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * linux/fs/fat/file.c
4 *
5 * Written 1992,1993 by Werner Almesberger
6 *
7 * regular file handling primitives for fat-based filesystems
8 */
9
10#include <linux/capability.h>
11#include <linux/module.h>
12#include <linux/compat.h>
13#include <linux/mount.h>
14#include <linux/blkdev.h>
15#include <linux/backing-dev.h>
16#include <linux/fsnotify.h>
17#include <linux/security.h>
18#include <linux/falloc.h>
19#include "fat.h"
20
21static long fat_fallocate(struct file *file, int mode,
22 loff_t offset, loff_t len);
23
24static int fat_ioctl_get_attributes(struct inode *inode, u32 __user *user_attr)
25{
26 u32 attr;
27
28 inode_lock_shared(inode);
29 attr = fat_make_attrs(inode);
30 inode_unlock_shared(inode);
31
32 return put_user(attr, user_attr);
33}
34
35static int fat_ioctl_set_attributes(struct file *file, u32 __user *user_attr)
36{
37 struct inode *inode = file_inode(file);
38 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
39 int is_dir = S_ISDIR(inode->i_mode);
40 u32 attr, oldattr;
41 struct iattr ia;
42 int err;
43
44 err = get_user(attr, user_attr);
45 if (err)
46 goto out;
47
48 err = mnt_want_write_file(file);
49 if (err)
50 goto out;
51 inode_lock(inode);
52
53 /*
54 * ATTR_VOLUME and ATTR_DIR cannot be changed; this also
55 * prevents the user from turning us into a VFAT
56 * longname entry. Also, we obviously can't set
57 * any of the NTFS attributes in the high 24 bits.
58 */
59 attr &= 0xff & ~(ATTR_VOLUME | ATTR_DIR);
60 /* Merge in ATTR_VOLUME and ATTR_DIR */
61 attr |= (MSDOS_I(inode)->i_attrs & ATTR_VOLUME) |
62 (is_dir ? ATTR_DIR : 0);
63 oldattr = fat_make_attrs(inode);
64
65 /* Equivalent to a chmod() */
66 ia.ia_valid = ATTR_MODE | ATTR_CTIME;
67 ia.ia_ctime = current_time(inode);
68 if (is_dir)
69 ia.ia_mode = fat_make_mode(sbi, attr, S_IRWXUGO);
70 else {
71 ia.ia_mode = fat_make_mode(sbi, attr,
72 S_IRUGO | S_IWUGO | (inode->i_mode & S_IXUGO));
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 out_unlock_inode;
79 }
80
81 if (sbi->options.sys_immutable &&
82 ((attr | oldattr) & ATTR_SYS) &&
83 !capable(CAP_LINUX_IMMUTABLE)) {
84 err = -EPERM;
85 goto out_unlock_inode;
86 }
87
88 /*
89 * The security check is questionable... We single
90 * out the RO attribute for checking by the security
91 * module, just because it maps to a file mode.
92 */
93 err = security_inode_setattr(file->f_path.dentry, &ia);
94 if (err)
95 goto out_unlock_inode;
96
97 /* This MUST be done before doing anything irreversible... */
98 err = fat_setattr(file_mnt_user_ns(file), file->f_path.dentry, &ia);
99 if (err)
100 goto out_unlock_inode;
101
102 fsnotify_change(file->f_path.dentry, ia.ia_valid);
103 if (sbi->options.sys_immutable) {
104 if (attr & ATTR_SYS)
105 inode->i_flags |= S_IMMUTABLE;
106 else
107 inode->i_flags &= ~S_IMMUTABLE;
108 }
109
110 fat_save_attrs(inode, attr);
111 mark_inode_dirty(inode);
112out_unlock_inode:
113 inode_unlock(inode);
114 mnt_drop_write_file(file);
115out:
116 return err;
117}
118
119static int fat_ioctl_get_volume_id(struct inode *inode, u32 __user *user_attr)
120{
121 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
122 return put_user(sbi->vol_id, user_attr);
123}
124
125static int fat_ioctl_fitrim(struct inode *inode, unsigned long arg)
126{
127 struct super_block *sb = inode->i_sb;
128 struct fstrim_range __user *user_range;
129 struct fstrim_range range;
130 struct request_queue *q = bdev_get_queue(sb->s_bdev);
131 int err;
132
133 if (!capable(CAP_SYS_ADMIN))
134 return -EPERM;
135
136 if (!blk_queue_discard(q))
137 return -EOPNOTSUPP;
138
139 user_range = (struct fstrim_range __user *)arg;
140 if (copy_from_user(&range, user_range, sizeof(range)))
141 return -EFAULT;
142
143 range.minlen = max_t(unsigned int, range.minlen,
144 q->limits.discard_granularity);
145
146 err = fat_trim_fs(inode, &range);
147 if (err < 0)
148 return err;
149
150 if (copy_to_user(user_range, &range, sizeof(range)))
151 return -EFAULT;
152
153 return 0;
154}
155
156long fat_generic_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
157{
158 struct inode *inode = file_inode(filp);
159 u32 __user *user_attr = (u32 __user *)arg;
160
161 switch (cmd) {
162 case FAT_IOCTL_GET_ATTRIBUTES:
163 return fat_ioctl_get_attributes(inode, user_attr);
164 case FAT_IOCTL_SET_ATTRIBUTES:
165 return fat_ioctl_set_attributes(filp, user_attr);
166 case FAT_IOCTL_GET_VOLUME_ID:
167 return fat_ioctl_get_volume_id(inode, user_attr);
168 case FITRIM:
169 return fat_ioctl_fitrim(inode, arg);
170 default:
171 return -ENOTTY; /* Inappropriate ioctl for device */
172 }
173}
174
175static int fat_file_release(struct inode *inode, struct file *filp)
176{
177 if ((filp->f_mode & FMODE_WRITE) &&
178 MSDOS_SB(inode->i_sb)->options.flush) {
179 fat_flush_inodes(inode->i_sb, inode, NULL);
180 congestion_wait(BLK_RW_ASYNC, HZ/10);
181 }
182 return 0;
183}
184
185int fat_file_fsync(struct file *filp, loff_t start, loff_t end, int datasync)
186{
187 struct inode *inode = filp->f_mapping->host;
188 int err;
189
190 err = __generic_file_fsync(filp, start, end, datasync);
191 if (err)
192 return err;
193
194 err = sync_mapping_buffers(MSDOS_SB(inode->i_sb)->fat_inode->i_mapping);
195 if (err)
196 return err;
197
198 return blkdev_issue_flush(inode->i_sb->s_bdev);
199}
200
201
202const struct file_operations fat_file_operations = {
203 .llseek = generic_file_llseek,
204 .read_iter = generic_file_read_iter,
205 .write_iter = generic_file_write_iter,
206 .mmap = generic_file_mmap,
207 .release = fat_file_release,
208 .unlocked_ioctl = fat_generic_ioctl,
209 .compat_ioctl = compat_ptr_ioctl,
210 .fsync = fat_file_fsync,
211 .splice_read = generic_file_splice_read,
212 .splice_write = iter_file_splice_write,
213 .fallocate = fat_fallocate,
214};
215
216static int fat_cont_expand(struct inode *inode, loff_t size)
217{
218 struct address_space *mapping = inode->i_mapping;
219 loff_t start = inode->i_size, count = size - inode->i_size;
220 int err;
221
222 err = generic_cont_expand_simple(inode, size);
223 if (err)
224 goto out;
225
226 fat_truncate_time(inode, NULL, S_CTIME|S_MTIME);
227 mark_inode_dirty(inode);
228 if (IS_SYNC(inode)) {
229 int err2;
230
231 /*
232 * Opencode syncing since we don't have a file open to use
233 * standard fsync path.
234 */
235 err = filemap_fdatawrite_range(mapping, start,
236 start + count - 1);
237 err2 = sync_mapping_buffers(mapping);
238 if (!err)
239 err = err2;
240 err2 = write_inode_now(inode, 1);
241 if (!err)
242 err = err2;
243 if (!err) {
244 err = filemap_fdatawait_range(mapping, start,
245 start + count - 1);
246 }
247 }
248out:
249 return err;
250}
251
252/*
253 * Preallocate space for a file. This implements fat's fallocate file
254 * operation, which gets called from sys_fallocate system call. User
255 * space requests len bytes at offset. If FALLOC_FL_KEEP_SIZE is set
256 * we just allocate clusters without zeroing them out. Otherwise we
257 * allocate and zero out clusters via an expanding truncate.
258 */
259static long fat_fallocate(struct file *file, int mode,
260 loff_t offset, loff_t len)
261{
262 int nr_cluster; /* Number of clusters to be allocated */
263 loff_t mm_bytes; /* Number of bytes to be allocated for file */
264 loff_t ondisksize; /* block aligned on-disk size in bytes*/
265 struct inode *inode = file->f_mapping->host;
266 struct super_block *sb = inode->i_sb;
267 struct msdos_sb_info *sbi = MSDOS_SB(sb);
268 int err = 0;
269
270 /* No support for hole punch or other fallocate flags. */
271 if (mode & ~FALLOC_FL_KEEP_SIZE)
272 return -EOPNOTSUPP;
273
274 /* No support for dir */
275 if (!S_ISREG(inode->i_mode))
276 return -EOPNOTSUPP;
277
278 inode_lock(inode);
279 if (mode & FALLOC_FL_KEEP_SIZE) {
280 ondisksize = inode->i_blocks << 9;
281 if ((offset + len) <= ondisksize)
282 goto error;
283
284 /* First compute the number of clusters to be allocated */
285 mm_bytes = offset + len - ondisksize;
286 nr_cluster = (mm_bytes + (sbi->cluster_size - 1)) >>
287 sbi->cluster_bits;
288
289 /* Start the allocation.We are not zeroing out the clusters */
290 while (nr_cluster-- > 0) {
291 err = fat_add_cluster(inode);
292 if (err)
293 goto error;
294 }
295 } else {
296 if ((offset + len) <= i_size_read(inode))
297 goto error;
298
299 /* This is just an expanding truncate */
300 err = fat_cont_expand(inode, (offset + len));
301 }
302
303error:
304 inode_unlock(inode);
305 return err;
306}
307
308/* Free all clusters after the skip'th cluster. */
309static int fat_free(struct inode *inode, int skip)
310{
311 struct super_block *sb = inode->i_sb;
312 int err, wait, free_start, i_start, i_logstart;
313
314 if (MSDOS_I(inode)->i_start == 0)
315 return 0;
316
317 fat_cache_inval_inode(inode);
318
319 wait = IS_DIRSYNC(inode);
320 i_start = free_start = MSDOS_I(inode)->i_start;
321 i_logstart = MSDOS_I(inode)->i_logstart;
322
323 /* First, we write the new file size. */
324 if (!skip) {
325 MSDOS_I(inode)->i_start = 0;
326 MSDOS_I(inode)->i_logstart = 0;
327 }
328 MSDOS_I(inode)->i_attrs |= ATTR_ARCH;
329 fat_truncate_time(inode, NULL, S_CTIME|S_MTIME);
330 if (wait) {
331 err = fat_sync_inode(inode);
332 if (err) {
333 MSDOS_I(inode)->i_start = i_start;
334 MSDOS_I(inode)->i_logstart = i_logstart;
335 return err;
336 }
337 } else
338 mark_inode_dirty(inode);
339
340 /* Write a new EOF, and get the remaining cluster chain for freeing. */
341 if (skip) {
342 struct fat_entry fatent;
343 int ret, fclus, dclus;
344
345 ret = fat_get_cluster(inode, skip - 1, &fclus, &dclus);
346 if (ret < 0)
347 return ret;
348 else if (ret == FAT_ENT_EOF)
349 return 0;
350
351 fatent_init(&fatent);
352 ret = fat_ent_read(inode, &fatent, dclus);
353 if (ret == FAT_ENT_EOF) {
354 fatent_brelse(&fatent);
355 return 0;
356 } else if (ret == FAT_ENT_FREE) {
357 fat_fs_error(sb,
358 "%s: invalid cluster chain (i_pos %lld)",
359 __func__, MSDOS_I(inode)->i_pos);
360 ret = -EIO;
361 } else if (ret > 0) {
362 err = fat_ent_write(inode, &fatent, FAT_ENT_EOF, wait);
363 if (err)
364 ret = err;
365 }
366 fatent_brelse(&fatent);
367 if (ret < 0)
368 return ret;
369
370 free_start = ret;
371 }
372 inode->i_blocks = skip << (MSDOS_SB(sb)->cluster_bits - 9);
373
374 /* Freeing the remained cluster chain */
375 return fat_free_clusters(inode, free_start);
376}
377
378void fat_truncate_blocks(struct inode *inode, loff_t offset)
379{
380 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
381 const unsigned int cluster_size = sbi->cluster_size;
382 int nr_clusters;
383
384 /*
385 * This protects against truncating a file bigger than it was then
386 * trying to write into the hole.
387 */
388 if (MSDOS_I(inode)->mmu_private > offset)
389 MSDOS_I(inode)->mmu_private = offset;
390
391 nr_clusters = (offset + (cluster_size - 1)) >> sbi->cluster_bits;
392
393 fat_free(inode, nr_clusters);
394 fat_flush_inodes(inode->i_sb, inode, NULL);
395}
396
397int fat_getattr(struct user_namespace *mnt_userns, const struct path *path,
398 struct kstat *stat, u32 request_mask, unsigned int flags)
399{
400 struct inode *inode = d_inode(path->dentry);
401 generic_fillattr(mnt_userns, inode, stat);
402 stat->blksize = MSDOS_SB(inode->i_sb)->cluster_size;
403
404 if (MSDOS_SB(inode->i_sb)->options.nfs == FAT_NFS_NOSTALE_RO) {
405 /* Use i_pos for ino. This is used as fileid of nfs. */
406 stat->ino = fat_i_pos_read(MSDOS_SB(inode->i_sb), inode);
407 }
408 return 0;
409}
410EXPORT_SYMBOL_GPL(fat_getattr);
411
412static int fat_sanitize_mode(const struct msdos_sb_info *sbi,
413 struct inode *inode, umode_t *mode_ptr)
414{
415 umode_t mask, perm;
416
417 /*
418 * Note, the basic check is already done by a caller of
419 * (attr->ia_mode & ~FAT_VALID_MODE)
420 */
421
422 if (S_ISREG(inode->i_mode))
423 mask = sbi->options.fs_fmask;
424 else
425 mask = sbi->options.fs_dmask;
426
427 perm = *mode_ptr & ~(S_IFMT | mask);
428
429 /*
430 * Of the r and x bits, all (subject to umask) must be present. Of the
431 * w bits, either all (subject to umask) or none must be present.
432 *
433 * If fat_mode_can_hold_ro(inode) is false, can't change w bits.
434 */
435 if ((perm & (S_IRUGO | S_IXUGO)) != (inode->i_mode & (S_IRUGO|S_IXUGO)))
436 return -EPERM;
437 if (fat_mode_can_hold_ro(inode)) {
438 if ((perm & S_IWUGO) && ((perm & S_IWUGO) != (S_IWUGO & ~mask)))
439 return -EPERM;
440 } else {
441 if ((perm & S_IWUGO) != (S_IWUGO & ~mask))
442 return -EPERM;
443 }
444
445 *mode_ptr &= S_IFMT | perm;
446
447 return 0;
448}
449
450static int fat_allow_set_time(struct user_namespace *mnt_userns,
451 struct msdos_sb_info *sbi, struct inode *inode)
452{
453 umode_t allow_utime = sbi->options.allow_utime;
454
455 if (!uid_eq(current_fsuid(), i_uid_into_mnt(mnt_userns, inode))) {
456 if (in_group_p(i_gid_into_mnt(mnt_userns, inode)))
457 allow_utime >>= 3;
458 if (allow_utime & MAY_WRITE)
459 return 1;
460 }
461
462 /* use a default check */
463 return 0;
464}
465
466#define TIMES_SET_FLAGS (ATTR_MTIME_SET | ATTR_ATIME_SET | ATTR_TIMES_SET)
467/* valid file mode bits */
468#define FAT_VALID_MODE (S_IFREG | S_IFDIR | S_IRWXUGO)
469
470int fat_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
471 struct iattr *attr)
472{
473 struct msdos_sb_info *sbi = MSDOS_SB(dentry->d_sb);
474 struct inode *inode = d_inode(dentry);
475 unsigned int ia_valid;
476 int error;
477
478 /* Check for setting the inode time. */
479 ia_valid = attr->ia_valid;
480 if (ia_valid & TIMES_SET_FLAGS) {
481 if (fat_allow_set_time(mnt_userns, sbi, inode))
482 attr->ia_valid &= ~TIMES_SET_FLAGS;
483 }
484
485 error = setattr_prepare(mnt_userns, dentry, attr);
486 attr->ia_valid = ia_valid;
487 if (error) {
488 if (sbi->options.quiet)
489 error = 0;
490 goto out;
491 }
492
493 /*
494 * Expand the file. Since inode_setattr() updates ->i_size
495 * before calling the ->truncate(), but FAT needs to fill the
496 * hole before it. XXX: this is no longer true with new truncate
497 * sequence.
498 */
499 if (attr->ia_valid & ATTR_SIZE) {
500 inode_dio_wait(inode);
501
502 if (attr->ia_size > inode->i_size) {
503 error = fat_cont_expand(inode, attr->ia_size);
504 if (error || attr->ia_valid == ATTR_SIZE)
505 goto out;
506 attr->ia_valid &= ~ATTR_SIZE;
507 }
508 }
509
510 if (((attr->ia_valid & ATTR_UID) &&
511 (!uid_eq(attr->ia_uid, sbi->options.fs_uid))) ||
512 ((attr->ia_valid & ATTR_GID) &&
513 (!gid_eq(attr->ia_gid, sbi->options.fs_gid))) ||
514 ((attr->ia_valid & ATTR_MODE) &&
515 (attr->ia_mode & ~FAT_VALID_MODE)))
516 error = -EPERM;
517
518 if (error) {
519 if (sbi->options.quiet)
520 error = 0;
521 goto out;
522 }
523
524 /*
525 * We don't return -EPERM here. Yes, strange, but this is too
526 * old behavior.
527 */
528 if (attr->ia_valid & ATTR_MODE) {
529 if (fat_sanitize_mode(sbi, inode, &attr->ia_mode) < 0)
530 attr->ia_valid &= ~ATTR_MODE;
531 }
532
533 if (attr->ia_valid & ATTR_SIZE) {
534 error = fat_block_truncate_page(inode, attr->ia_size);
535 if (error)
536 goto out;
537 down_write(&MSDOS_I(inode)->truncate_lock);
538 truncate_setsize(inode, attr->ia_size);
539 fat_truncate_blocks(inode, attr->ia_size);
540 up_write(&MSDOS_I(inode)->truncate_lock);
541 }
542
543 /*
544 * setattr_copy can't truncate these appropriately, so we'll
545 * copy them ourselves
546 */
547 if (attr->ia_valid & ATTR_ATIME)
548 fat_truncate_time(inode, &attr->ia_atime, S_ATIME);
549 if (attr->ia_valid & ATTR_CTIME)
550 fat_truncate_time(inode, &attr->ia_ctime, S_CTIME);
551 if (attr->ia_valid & ATTR_MTIME)
552 fat_truncate_time(inode, &attr->ia_mtime, S_MTIME);
553 attr->ia_valid &= ~(ATTR_ATIME|ATTR_CTIME|ATTR_MTIME);
554
555 setattr_copy(mnt_userns, inode, attr);
556 mark_inode_dirty(inode);
557out:
558 return error;
559}
560EXPORT_SYMBOL_GPL(fat_setattr);
561
562const struct inode_operations fat_file_inode_operations = {
563 .setattr = fat_setattr,
564 .getattr = fat_getattr,
565 .update_time = fat_update_time,
566};