Loading...
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(inode);
29 attr = fat_make_attrs(inode);
30 inode_unlock(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->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
175#ifdef CONFIG_COMPAT
176static long fat_generic_compat_ioctl(struct file *filp, unsigned int cmd,
177 unsigned long arg)
178
179{
180 return fat_generic_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
181}
182#endif
183
184static int fat_file_release(struct inode *inode, struct file *filp)
185{
186 if ((filp->f_mode & FMODE_WRITE) &&
187 MSDOS_SB(inode->i_sb)->options.flush) {
188 fat_flush_inodes(inode->i_sb, inode, NULL);
189 congestion_wait(BLK_RW_ASYNC, HZ/10);
190 }
191 return 0;
192}
193
194int fat_file_fsync(struct file *filp, loff_t start, loff_t end, int datasync)
195{
196 struct inode *inode = filp->f_mapping->host;
197 int err;
198
199 err = __generic_file_fsync(filp, start, end, datasync);
200 if (err)
201 return err;
202
203 err = sync_mapping_buffers(MSDOS_SB(inode->i_sb)->fat_inode->i_mapping);
204 if (err)
205 return err;
206
207 return blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL);
208}
209
210
211const struct file_operations fat_file_operations = {
212 .llseek = generic_file_llseek,
213 .read_iter = generic_file_read_iter,
214 .write_iter = generic_file_write_iter,
215 .mmap = generic_file_mmap,
216 .release = fat_file_release,
217 .unlocked_ioctl = fat_generic_ioctl,
218#ifdef CONFIG_COMPAT
219 .compat_ioctl = fat_generic_compat_ioctl,
220#endif
221 .fsync = fat_file_fsync,
222 .splice_read = generic_file_splice_read,
223 .splice_write = iter_file_splice_write,
224 .fallocate = fat_fallocate,
225};
226
227static int fat_cont_expand(struct inode *inode, loff_t size)
228{
229 struct address_space *mapping = inode->i_mapping;
230 loff_t start = inode->i_size, count = size - inode->i_size;
231 int err;
232
233 err = generic_cont_expand_simple(inode, size);
234 if (err)
235 goto out;
236
237 fat_truncate_time(inode, NULL, S_CTIME|S_MTIME);
238 mark_inode_dirty(inode);
239 if (IS_SYNC(inode)) {
240 int err2;
241
242 /*
243 * Opencode syncing since we don't have a file open to use
244 * standard fsync path.
245 */
246 err = filemap_fdatawrite_range(mapping, start,
247 start + count - 1);
248 err2 = sync_mapping_buffers(mapping);
249 if (!err)
250 err = err2;
251 err2 = write_inode_now(inode, 1);
252 if (!err)
253 err = err2;
254 if (!err) {
255 err = filemap_fdatawait_range(mapping, start,
256 start + count - 1);
257 }
258 }
259out:
260 return err;
261}
262
263/*
264 * Preallocate space for a file. This implements fat's fallocate file
265 * operation, which gets called from sys_fallocate system call. User
266 * space requests len bytes at offset. If FALLOC_FL_KEEP_SIZE is set
267 * we just allocate clusters without zeroing them out. Otherwise we
268 * allocate and zero out clusters via an expanding truncate.
269 */
270static long fat_fallocate(struct file *file, int mode,
271 loff_t offset, loff_t len)
272{
273 int nr_cluster; /* Number of clusters to be allocated */
274 loff_t mm_bytes; /* Number of bytes to be allocated for file */
275 loff_t ondisksize; /* block aligned on-disk size in bytes*/
276 struct inode *inode = file->f_mapping->host;
277 struct super_block *sb = inode->i_sb;
278 struct msdos_sb_info *sbi = MSDOS_SB(sb);
279 int err = 0;
280
281 /* No support for hole punch or other fallocate flags. */
282 if (mode & ~FALLOC_FL_KEEP_SIZE)
283 return -EOPNOTSUPP;
284
285 /* No support for dir */
286 if (!S_ISREG(inode->i_mode))
287 return -EOPNOTSUPP;
288
289 inode_lock(inode);
290 if (mode & FALLOC_FL_KEEP_SIZE) {
291 ondisksize = inode->i_blocks << 9;
292 if ((offset + len) <= ondisksize)
293 goto error;
294
295 /* First compute the number of clusters to be allocated */
296 mm_bytes = offset + len - ondisksize;
297 nr_cluster = (mm_bytes + (sbi->cluster_size - 1)) >>
298 sbi->cluster_bits;
299
300 /* Start the allocation.We are not zeroing out the clusters */
301 while (nr_cluster-- > 0) {
302 err = fat_add_cluster(inode);
303 if (err)
304 goto error;
305 }
306 } else {
307 if ((offset + len) <= i_size_read(inode))
308 goto error;
309
310 /* This is just an expanding truncate */
311 err = fat_cont_expand(inode, (offset + len));
312 }
313
314error:
315 inode_unlock(inode);
316 return err;
317}
318
319/* Free all clusters after the skip'th cluster. */
320static int fat_free(struct inode *inode, int skip)
321{
322 struct super_block *sb = inode->i_sb;
323 int err, wait, free_start, i_start, i_logstart;
324
325 if (MSDOS_I(inode)->i_start == 0)
326 return 0;
327
328 fat_cache_inval_inode(inode);
329
330 wait = IS_DIRSYNC(inode);
331 i_start = free_start = MSDOS_I(inode)->i_start;
332 i_logstart = MSDOS_I(inode)->i_logstart;
333
334 /* First, we write the new file size. */
335 if (!skip) {
336 MSDOS_I(inode)->i_start = 0;
337 MSDOS_I(inode)->i_logstart = 0;
338 }
339 MSDOS_I(inode)->i_attrs |= ATTR_ARCH;
340 fat_truncate_time(inode, NULL, S_CTIME|S_MTIME);
341 if (wait) {
342 err = fat_sync_inode(inode);
343 if (err) {
344 MSDOS_I(inode)->i_start = i_start;
345 MSDOS_I(inode)->i_logstart = i_logstart;
346 return err;
347 }
348 } else
349 mark_inode_dirty(inode);
350
351 /* Write a new EOF, and get the remaining cluster chain for freeing. */
352 if (skip) {
353 struct fat_entry fatent;
354 int ret, fclus, dclus;
355
356 ret = fat_get_cluster(inode, skip - 1, &fclus, &dclus);
357 if (ret < 0)
358 return ret;
359 else if (ret == FAT_ENT_EOF)
360 return 0;
361
362 fatent_init(&fatent);
363 ret = fat_ent_read(inode, &fatent, dclus);
364 if (ret == FAT_ENT_EOF) {
365 fatent_brelse(&fatent);
366 return 0;
367 } else if (ret == FAT_ENT_FREE) {
368 fat_fs_error(sb,
369 "%s: invalid cluster chain (i_pos %lld)",
370 __func__, MSDOS_I(inode)->i_pos);
371 ret = -EIO;
372 } else if (ret > 0) {
373 err = fat_ent_write(inode, &fatent, FAT_ENT_EOF, wait);
374 if (err)
375 ret = err;
376 }
377 fatent_brelse(&fatent);
378 if (ret < 0)
379 return ret;
380
381 free_start = ret;
382 }
383 inode->i_blocks = skip << (MSDOS_SB(sb)->cluster_bits - 9);
384
385 /* Freeing the remained cluster chain */
386 return fat_free_clusters(inode, free_start);
387}
388
389void fat_truncate_blocks(struct inode *inode, loff_t offset)
390{
391 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
392 const unsigned int cluster_size = sbi->cluster_size;
393 int nr_clusters;
394
395 /*
396 * This protects against truncating a file bigger than it was then
397 * trying to write into the hole.
398 */
399 if (MSDOS_I(inode)->mmu_private > offset)
400 MSDOS_I(inode)->mmu_private = offset;
401
402 nr_clusters = (offset + (cluster_size - 1)) >> sbi->cluster_bits;
403
404 fat_free(inode, nr_clusters);
405 fat_flush_inodes(inode->i_sb, inode, NULL);
406}
407
408int fat_getattr(const struct path *path, struct kstat *stat,
409 u32 request_mask, unsigned int flags)
410{
411 struct inode *inode = d_inode(path->dentry);
412 generic_fillattr(inode, stat);
413 stat->blksize = MSDOS_SB(inode->i_sb)->cluster_size;
414
415 if (MSDOS_SB(inode->i_sb)->options.nfs == FAT_NFS_NOSTALE_RO) {
416 /* Use i_pos for ino. This is used as fileid of nfs. */
417 stat->ino = fat_i_pos_read(MSDOS_SB(inode->i_sb), inode);
418 }
419 return 0;
420}
421EXPORT_SYMBOL_GPL(fat_getattr);
422
423static int fat_sanitize_mode(const struct msdos_sb_info *sbi,
424 struct inode *inode, umode_t *mode_ptr)
425{
426 umode_t mask, perm;
427
428 /*
429 * Note, the basic check is already done by a caller of
430 * (attr->ia_mode & ~FAT_VALID_MODE)
431 */
432
433 if (S_ISREG(inode->i_mode))
434 mask = sbi->options.fs_fmask;
435 else
436 mask = sbi->options.fs_dmask;
437
438 perm = *mode_ptr & ~(S_IFMT | mask);
439
440 /*
441 * Of the r and x bits, all (subject to umask) must be present. Of the
442 * w bits, either all (subject to umask) or none must be present.
443 *
444 * If fat_mode_can_hold_ro(inode) is false, can't change w bits.
445 */
446 if ((perm & (S_IRUGO | S_IXUGO)) != (inode->i_mode & (S_IRUGO|S_IXUGO)))
447 return -EPERM;
448 if (fat_mode_can_hold_ro(inode)) {
449 if ((perm & S_IWUGO) && ((perm & S_IWUGO) != (S_IWUGO & ~mask)))
450 return -EPERM;
451 } else {
452 if ((perm & S_IWUGO) != (S_IWUGO & ~mask))
453 return -EPERM;
454 }
455
456 *mode_ptr &= S_IFMT | perm;
457
458 return 0;
459}
460
461static int fat_allow_set_time(struct msdos_sb_info *sbi, struct inode *inode)
462{
463 umode_t allow_utime = sbi->options.allow_utime;
464
465 if (!uid_eq(current_fsuid(), inode->i_uid)) {
466 if (in_group_p(inode->i_gid))
467 allow_utime >>= 3;
468 if (allow_utime & MAY_WRITE)
469 return 1;
470 }
471
472 /* use a default check */
473 return 0;
474}
475
476#define TIMES_SET_FLAGS (ATTR_MTIME_SET | ATTR_ATIME_SET | ATTR_TIMES_SET)
477/* valid file mode bits */
478#define FAT_VALID_MODE (S_IFREG | S_IFDIR | S_IRWXUGO)
479
480int fat_setattr(struct dentry *dentry, struct iattr *attr)
481{
482 struct msdos_sb_info *sbi = MSDOS_SB(dentry->d_sb);
483 struct inode *inode = d_inode(dentry);
484 unsigned int ia_valid;
485 int error;
486
487 /* Check for setting the inode time. */
488 ia_valid = attr->ia_valid;
489 if (ia_valid & TIMES_SET_FLAGS) {
490 if (fat_allow_set_time(sbi, inode))
491 attr->ia_valid &= ~TIMES_SET_FLAGS;
492 }
493
494 error = setattr_prepare(dentry, attr);
495 attr->ia_valid = ia_valid;
496 if (error) {
497 if (sbi->options.quiet)
498 error = 0;
499 goto out;
500 }
501
502 /*
503 * Expand the file. Since inode_setattr() updates ->i_size
504 * before calling the ->truncate(), but FAT needs to fill the
505 * hole before it. XXX: this is no longer true with new truncate
506 * sequence.
507 */
508 if (attr->ia_valid & ATTR_SIZE) {
509 inode_dio_wait(inode);
510
511 if (attr->ia_size > inode->i_size) {
512 error = fat_cont_expand(inode, attr->ia_size);
513 if (error || attr->ia_valid == ATTR_SIZE)
514 goto out;
515 attr->ia_valid &= ~ATTR_SIZE;
516 }
517 }
518
519 if (((attr->ia_valid & ATTR_UID) &&
520 (!uid_eq(attr->ia_uid, sbi->options.fs_uid))) ||
521 ((attr->ia_valid & ATTR_GID) &&
522 (!gid_eq(attr->ia_gid, sbi->options.fs_gid))) ||
523 ((attr->ia_valid & ATTR_MODE) &&
524 (attr->ia_mode & ~FAT_VALID_MODE)))
525 error = -EPERM;
526
527 if (error) {
528 if (sbi->options.quiet)
529 error = 0;
530 goto out;
531 }
532
533 /*
534 * We don't return -EPERM here. Yes, strange, but this is too
535 * old behavior.
536 */
537 if (attr->ia_valid & ATTR_MODE) {
538 if (fat_sanitize_mode(sbi, inode, &attr->ia_mode) < 0)
539 attr->ia_valid &= ~ATTR_MODE;
540 }
541
542 if (attr->ia_valid & ATTR_SIZE) {
543 error = fat_block_truncate_page(inode, attr->ia_size);
544 if (error)
545 goto out;
546 down_write(&MSDOS_I(inode)->truncate_lock);
547 truncate_setsize(inode, attr->ia_size);
548 fat_truncate_blocks(inode, attr->ia_size);
549 up_write(&MSDOS_I(inode)->truncate_lock);
550 }
551
552 /*
553 * setattr_copy can't truncate these appropriately, so we'll
554 * copy them ourselves
555 */
556 if (attr->ia_valid & ATTR_ATIME)
557 fat_truncate_time(inode, &attr->ia_atime, S_ATIME);
558 if (attr->ia_valid & ATTR_CTIME)
559 fat_truncate_time(inode, &attr->ia_ctime, S_CTIME);
560 if (attr->ia_valid & ATTR_MTIME)
561 fat_truncate_time(inode, &attr->ia_mtime, S_MTIME);
562 attr->ia_valid &= ~(ATTR_ATIME|ATTR_CTIME|ATTR_MTIME);
563
564 setattr_copy(inode, attr);
565 mark_inode_dirty(inode);
566out:
567 return error;
568}
569EXPORT_SYMBOL_GPL(fat_setattr);
570
571const struct inode_operations fat_file_inode_operations = {
572 .setattr = fat_setattr,
573 .getattr = fat_getattr,
574 .update_time = fat_update_time,
575};
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->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, GFP_KERNEL);
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(const struct path *path, struct kstat *stat,
398 u32 request_mask, unsigned int flags)
399{
400 struct inode *inode = d_inode(path->dentry);
401 generic_fillattr(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 msdos_sb_info *sbi, struct inode *inode)
451{
452 umode_t allow_utime = sbi->options.allow_utime;
453
454 if (!uid_eq(current_fsuid(), inode->i_uid)) {
455 if (in_group_p(inode->i_gid))
456 allow_utime >>= 3;
457 if (allow_utime & MAY_WRITE)
458 return 1;
459 }
460
461 /* use a default check */
462 return 0;
463}
464
465#define TIMES_SET_FLAGS (ATTR_MTIME_SET | ATTR_ATIME_SET | ATTR_TIMES_SET)
466/* valid file mode bits */
467#define FAT_VALID_MODE (S_IFREG | S_IFDIR | S_IRWXUGO)
468
469int fat_setattr(struct dentry *dentry, struct iattr *attr)
470{
471 struct msdos_sb_info *sbi = MSDOS_SB(dentry->d_sb);
472 struct inode *inode = d_inode(dentry);
473 unsigned int ia_valid;
474 int error;
475
476 /* Check for setting the inode time. */
477 ia_valid = attr->ia_valid;
478 if (ia_valid & TIMES_SET_FLAGS) {
479 if (fat_allow_set_time(sbi, inode))
480 attr->ia_valid &= ~TIMES_SET_FLAGS;
481 }
482
483 error = setattr_prepare(dentry, attr);
484 attr->ia_valid = ia_valid;
485 if (error) {
486 if (sbi->options.quiet)
487 error = 0;
488 goto out;
489 }
490
491 /*
492 * Expand the file. Since inode_setattr() updates ->i_size
493 * before calling the ->truncate(), but FAT needs to fill the
494 * hole before it. XXX: this is no longer true with new truncate
495 * sequence.
496 */
497 if (attr->ia_valid & ATTR_SIZE) {
498 inode_dio_wait(inode);
499
500 if (attr->ia_size > inode->i_size) {
501 error = fat_cont_expand(inode, attr->ia_size);
502 if (error || attr->ia_valid == ATTR_SIZE)
503 goto out;
504 attr->ia_valid &= ~ATTR_SIZE;
505 }
506 }
507
508 if (((attr->ia_valid & ATTR_UID) &&
509 (!uid_eq(attr->ia_uid, sbi->options.fs_uid))) ||
510 ((attr->ia_valid & ATTR_GID) &&
511 (!gid_eq(attr->ia_gid, sbi->options.fs_gid))) ||
512 ((attr->ia_valid & ATTR_MODE) &&
513 (attr->ia_mode & ~FAT_VALID_MODE)))
514 error = -EPERM;
515
516 if (error) {
517 if (sbi->options.quiet)
518 error = 0;
519 goto out;
520 }
521
522 /*
523 * We don't return -EPERM here. Yes, strange, but this is too
524 * old behavior.
525 */
526 if (attr->ia_valid & ATTR_MODE) {
527 if (fat_sanitize_mode(sbi, inode, &attr->ia_mode) < 0)
528 attr->ia_valid &= ~ATTR_MODE;
529 }
530
531 if (attr->ia_valid & ATTR_SIZE) {
532 error = fat_block_truncate_page(inode, attr->ia_size);
533 if (error)
534 goto out;
535 down_write(&MSDOS_I(inode)->truncate_lock);
536 truncate_setsize(inode, attr->ia_size);
537 fat_truncate_blocks(inode, attr->ia_size);
538 up_write(&MSDOS_I(inode)->truncate_lock);
539 }
540
541 /*
542 * setattr_copy can't truncate these appropriately, so we'll
543 * copy them ourselves
544 */
545 if (attr->ia_valid & ATTR_ATIME)
546 fat_truncate_time(inode, &attr->ia_atime, S_ATIME);
547 if (attr->ia_valid & ATTR_CTIME)
548 fat_truncate_time(inode, &attr->ia_ctime, S_CTIME);
549 if (attr->ia_valid & ATTR_MTIME)
550 fat_truncate_time(inode, &attr->ia_mtime, S_MTIME);
551 attr->ia_valid &= ~(ATTR_ATIME|ATTR_CTIME|ATTR_MTIME);
552
553 setattr_copy(inode, attr);
554 mark_inode_dirty(inode);
555out:
556 return error;
557}
558EXPORT_SYMBOL_GPL(fat_setattr);
559
560const struct inode_operations fat_file_inode_operations = {
561 .setattr = fat_setattr,
562 .getattr = fat_getattr,
563 .update_time = fat_update_time,
564};