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perf bpf: Move perf_event_output() from stdio.h to bpf.h
[linux/fpc-iii.git] / fs / fat / file.c
blob13935ee99e1e53038f458e257d48f11cc7426591
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
20 static long fat_fallocate(struct file *file, int mode,
21 loff_t offset, loff_t len);
22
23 static 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
34 static 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_time(inode);
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);
111 out_unlock_inode:
112 inode_unlock(inode);
113 mnt_drop_write_file(file);
114 out:
115 return err;
116 }
117
118 static 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
124 static int fat_ioctl_fitrim(struct inode *inode, unsigned long arg)
125 {
126 struct super_block *sb = inode->i_sb;
127 struct fstrim_range __user *user_range;
128 struct fstrim_range range;
129 struct request_queue *q = bdev_get_queue(sb->s_bdev);
130 int err;
131
132 if (!capable(CAP_SYS_ADMIN))
133 return -EPERM;
134
135 if (!blk_queue_discard(q))
136 return -EOPNOTSUPP;
137
138 user_range = (struct fstrim_range __user *)arg;
139 if (copy_from_user(&range, user_range, sizeof(range)))
140 return -EFAULT;
141
142 range.minlen = max_t(unsigned int, range.minlen,
143 q->limits.discard_granularity);
144
145 err = fat_trim_fs(inode, &range);
146 if (err < 0)
147 return err;
148
149 if (copy_to_user(user_range, &range, sizeof(range)))
150 return -EFAULT;
151
152 return 0;
153 }
154
155 long fat_generic_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
156 {
157 struct inode *inode = file_inode(filp);
158 u32 __user *user_attr = (u32 __user *)arg;
159
160 switch (cmd) {
161 case FAT_IOCTL_GET_ATTRIBUTES:
162 return fat_ioctl_get_attributes(inode, user_attr);
163 case FAT_IOCTL_SET_ATTRIBUTES:
164 return fat_ioctl_set_attributes(filp, user_attr);
165 case FAT_IOCTL_GET_VOLUME_ID:
166 return fat_ioctl_get_volume_id(inode, user_attr);
167 case FITRIM:
168 return fat_ioctl_fitrim(inode, arg);
169 default:
170 return -ENOTTY; /* Inappropriate ioctl for device */
171 }
172 }
173
174 #ifdef CONFIG_COMPAT
175 static long fat_generic_compat_ioctl(struct file *filp, unsigned int cmd,
176 unsigned long arg)
177
178 {
179 return fat_generic_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
180 }
181 #endif
182
183 static int fat_file_release(struct inode *inode, struct file *filp)
184 {
185 if ((filp->f_mode & FMODE_WRITE) &&
186 MSDOS_SB(inode->i_sb)->options.flush) {
187 fat_flush_inodes(inode->i_sb, inode, NULL);
188 congestion_wait(BLK_RW_ASYNC, HZ/10);
189 }
190 return 0;
191 }
192
193 int fat_file_fsync(struct file *filp, loff_t start, loff_t end, int datasync)
194 {
195 struct inode *inode = filp->f_mapping->host;
196 int res, err;
197
198 res = generic_file_fsync(filp, start, end, datasync);
199 err = sync_mapping_buffers(MSDOS_SB(inode->i_sb)->fat_inode->i_mapping);
200
201 return res ? res : err;
202 }
203
204
205 const struct file_operations fat_file_operations = {
206 .llseek = generic_file_llseek,
207 .read_iter = generic_file_read_iter,
208 .write_iter = generic_file_write_iter,
209 .mmap = generic_file_mmap,
210 .release = fat_file_release,
211 .unlocked_ioctl = fat_generic_ioctl,
212 #ifdef CONFIG_COMPAT
213 .compat_ioctl = fat_generic_compat_ioctl,
214 #endif
215 .fsync = fat_file_fsync,
216 .splice_read = generic_file_splice_read,
217 .fallocate = fat_fallocate,
218 };
219
220 static int fat_cont_expand(struct inode *inode, loff_t size)
221 {
222 struct address_space *mapping = inode->i_mapping;
223 loff_t start = inode->i_size, count = size - inode->i_size;
224 int err;
225
226 err = generic_cont_expand_simple(inode, size);
227 if (err)
228 goto out;
229
230 fat_truncate_time(inode, NULL, S_CTIME|S_MTIME);
231 mark_inode_dirty(inode);
232 if (IS_SYNC(inode)) {
233 int err2;
234
235 /*
236 * Opencode syncing since we don't have a file open to use
237 * standard fsync path.
238 */
239 err = filemap_fdatawrite_range(mapping, start,
240 start + count - 1);
241 err2 = sync_mapping_buffers(mapping);
242 if (!err)
243 err = err2;
244 err2 = write_inode_now(inode, 1);
245 if (!err)
246 err = err2;
247 if (!err) {
248 err = filemap_fdatawait_range(mapping, start,
249 start + count - 1);
250 }
251 }
252 out:
253 return err;
254 }
255
256 /*
257 * Preallocate space for a file. This implements fat's fallocate file
258 * operation, which gets called from sys_fallocate system call. User
259 * space requests len bytes at offset. If FALLOC_FL_KEEP_SIZE is set
260 * we just allocate clusters without zeroing them out. Otherwise we
261 * allocate and zero out clusters via an expanding truncate.
262 */
263 static long fat_fallocate(struct file *file, int mode,
264 loff_t offset, loff_t len)
265 {
266 int nr_cluster; /* Number of clusters to be allocated */
267 loff_t mm_bytes; /* Number of bytes to be allocated for file */
268 loff_t ondisksize; /* block aligned on-disk size in bytes*/
269 struct inode *inode = file->f_mapping->host;
270 struct super_block *sb = inode->i_sb;
271 struct msdos_sb_info *sbi = MSDOS_SB(sb);
272 int err = 0;
273
274 /* No support for hole punch or other fallocate flags. */
275 if (mode & ~FALLOC_FL_KEEP_SIZE)
276 return -EOPNOTSUPP;
277
278 /* No support for dir */
279 if (!S_ISREG(inode->i_mode))
280 return -EOPNOTSUPP;
281
282 inode_lock(inode);
283 if (mode & FALLOC_FL_KEEP_SIZE) {
284 ondisksize = inode->i_blocks << 9;
285 if ((offset + len) <= ondisksize)
286 goto error;
287
288 /* First compute the number of clusters to be allocated */
289 mm_bytes = offset + len - ondisksize;
290 nr_cluster = (mm_bytes + (sbi->cluster_size - 1)) >>
291 sbi->cluster_bits;
292
293 /* Start the allocation.We are not zeroing out the clusters */
294 while (nr_cluster-- > 0) {
295 err = fat_add_cluster(inode);
296 if (err)
297 goto error;
298 }
299 } else {
300 if ((offset + len) <= i_size_read(inode))
301 goto error;
302
303 /* This is just an expanding truncate */
304 err = fat_cont_expand(inode, (offset + len));
305 }
306
307 error:
308 inode_unlock(inode);
309 return err;
310 }
311
312 /* Free all clusters after the skip'th cluster. */
313 static int fat_free(struct inode *inode, int skip)
314 {
315 struct super_block *sb = inode->i_sb;
316 int err, wait, free_start, i_start, i_logstart;
317
318 if (MSDOS_I(inode)->i_start == 0)
319 return 0;
320
321 fat_cache_inval_inode(inode);
322
323 wait = IS_DIRSYNC(inode);
324 i_start = free_start = MSDOS_I(inode)->i_start;
325 i_logstart = MSDOS_I(inode)->i_logstart;
326
327 /* First, we write the new file size. */
328 if (!skip) {
329 MSDOS_I(inode)->i_start = 0;
330 MSDOS_I(inode)->i_logstart = 0;
331 }
332 MSDOS_I(inode)->i_attrs |= ATTR_ARCH;
333 fat_truncate_time(inode, NULL, S_CTIME|S_MTIME);
334 if (wait) {
335 err = fat_sync_inode(inode);
336 if (err) {
337 MSDOS_I(inode)->i_start = i_start;
338 MSDOS_I(inode)->i_logstart = i_logstart;
339 return err;
340 }
341 } else
342 mark_inode_dirty(inode);
343
344 /* Write a new EOF, and get the remaining cluster chain for freeing. */
345 if (skip) {
346 struct fat_entry fatent;
347 int ret, fclus, dclus;
348
349 ret = fat_get_cluster(inode, skip - 1, &fclus, &dclus);
350 if (ret < 0)
351 return ret;
352 else if (ret == FAT_ENT_EOF)
353 return 0;
354
355 fatent_init(&fatent);
356 ret = fat_ent_read(inode, &fatent, dclus);
357 if (ret == FAT_ENT_EOF) {
358 fatent_brelse(&fatent);
359 return 0;
360 } else if (ret == FAT_ENT_FREE) {
361 fat_fs_error(sb,
362 "%s: invalid cluster chain (i_pos %lld)",
363 __func__, MSDOS_I(inode)->i_pos);
364 ret = -EIO;
365 } else if (ret > 0) {
366 err = fat_ent_write(inode, &fatent, FAT_ENT_EOF, wait);
367 if (err)
368 ret = err;
369 }
370 fatent_brelse(&fatent);
371 if (ret < 0)
372 return ret;
373
374 free_start = ret;
375 }
376 inode->i_blocks = skip << (MSDOS_SB(sb)->cluster_bits - 9);
377
378 /* Freeing the remained cluster chain */
379 return fat_free_clusters(inode, free_start);
380 }
381
382 void fat_truncate_blocks(struct inode *inode, loff_t offset)
383 {
384 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
385 const unsigned int cluster_size = sbi->cluster_size;
386 int nr_clusters;
387
388 /*
389 * This protects against truncating a file bigger than it was then
390 * trying to write into the hole.
391 */
392 if (MSDOS_I(inode)->mmu_private > offset)
393 MSDOS_I(inode)->mmu_private = offset;
394
395 nr_clusters = (offset + (cluster_size - 1)) >> sbi->cluster_bits;
396
397 fat_free(inode, nr_clusters);
398 fat_flush_inodes(inode->i_sb, inode, NULL);
399 }
400
401 int fat_getattr(const struct path *path, struct kstat *stat,
402 u32 request_mask, unsigned int flags)
403 {
404 struct inode *inode = d_inode(path->dentry);
405 generic_fillattr(inode, stat);
406 stat->blksize = MSDOS_SB(inode->i_sb)->cluster_size;
407
408 if (MSDOS_SB(inode->i_sb)->options.nfs == FAT_NFS_NOSTALE_RO) {
409 /* Use i_pos for ino. This is used as fileid of nfs. */
410 stat->ino = fat_i_pos_read(MSDOS_SB(inode->i_sb), inode);
411 }
412 return 0;
413 }
414 EXPORT_SYMBOL_GPL(fat_getattr);
415
416 static int fat_sanitize_mode(const struct msdos_sb_info *sbi,
417 struct inode *inode, umode_t *mode_ptr)
418 {
419 umode_t mask, perm;
420
421 /*
422 * Note, the basic check is already done by a caller of
423 * (attr->ia_mode & ~FAT_VALID_MODE)
424 */
425
426 if (S_ISREG(inode->i_mode))
427 mask = sbi->options.fs_fmask;
428 else
429 mask = sbi->options.fs_dmask;
430
431 perm = *mode_ptr & ~(S_IFMT | mask);
432
433 /*
434 * Of the r and x bits, all (subject to umask) must be present. Of the
435 * w bits, either all (subject to umask) or none must be present.
436 *
437 * If fat_mode_can_hold_ro(inode) is false, can't change w bits.
438 */
439 if ((perm & (S_IRUGO | S_IXUGO)) != (inode->i_mode & (S_IRUGO|S_IXUGO)))
440 return -EPERM;
441 if (fat_mode_can_hold_ro(inode)) {
442 if ((perm & S_IWUGO) && ((perm & S_IWUGO) != (S_IWUGO & ~mask)))
443 return -EPERM;
444 } else {
445 if ((perm & S_IWUGO) != (S_IWUGO & ~mask))
446 return -EPERM;
447 }
448
449 *mode_ptr &= S_IFMT | perm;
450
451 return 0;
452 }
453
454 static int fat_allow_set_time(struct msdos_sb_info *sbi, struct inode *inode)
455 {
456 umode_t allow_utime = sbi->options.allow_utime;
457
458 if (!uid_eq(current_fsuid(), inode->i_uid)) {
459 if (in_group_p(inode->i_gid))
460 allow_utime >>= 3;
461 if (allow_utime & MAY_WRITE)
462 return 1;
463 }
464
465 /* use a default check */
466 return 0;
467 }
468
469 #define TIMES_SET_FLAGS (ATTR_MTIME_SET | ATTR_ATIME_SET | ATTR_TIMES_SET)
470 /* valid file mode bits */
471 #define FAT_VALID_MODE (S_IFREG | S_IFDIR | S_IRWXUGO)
472
473 int fat_setattr(struct dentry *dentry, struct iattr *attr)
474 {
475 struct msdos_sb_info *sbi = MSDOS_SB(dentry->d_sb);
476 struct inode *inode = d_inode(dentry);
477 unsigned int ia_valid;
478 int error;
479
480 /* Check for setting the inode time. */
481 ia_valid = attr->ia_valid;
482 if (ia_valid & TIMES_SET_FLAGS) {
483 if (fat_allow_set_time(sbi, inode))
484 attr->ia_valid &= ~TIMES_SET_FLAGS;
485 }
486
487 error = setattr_prepare(dentry, attr);
488 attr->ia_valid = ia_valid;
489 if (error) {
490 if (sbi->options.quiet)
491 error = 0;
492 goto out;
493 }
494
495 /*
496 * Expand the file. Since inode_setattr() updates ->i_size
497 * before calling the ->truncate(), but FAT needs to fill the
498 * hole before it. XXX: this is no longer true with new truncate
499 * sequence.
500 */
501 if (attr->ia_valid & ATTR_SIZE) {
502 inode_dio_wait(inode);
503
504 if (attr->ia_size > inode->i_size) {
505 error = fat_cont_expand(inode, attr->ia_size);
506 if (error || attr->ia_valid == ATTR_SIZE)
507 goto out;
508 attr->ia_valid &= ~ATTR_SIZE;
509 }
510 }
511
512 if (((attr->ia_valid & ATTR_UID) &&
513 (!uid_eq(attr->ia_uid, sbi->options.fs_uid))) ||
514 ((attr->ia_valid & ATTR_GID) &&
515 (!gid_eq(attr->ia_gid, sbi->options.fs_gid))) ||
516 ((attr->ia_valid & ATTR_MODE) &&
517 (attr->ia_mode & ~FAT_VALID_MODE)))
518 error = -EPERM;
519
520 if (error) {
521 if (sbi->options.quiet)
522 error = 0;
523 goto out;
524 }
525
526 /*
527 * We don't return -EPERM here. Yes, strange, but this is too
528 * old behavior.
529 */
530 if (attr->ia_valid & ATTR_MODE) {
531 if (fat_sanitize_mode(sbi, inode, &attr->ia_mode) < 0)
532 attr->ia_valid &= ~ATTR_MODE;
533 }
534
535 if (attr->ia_valid & ATTR_SIZE) {
536 error = fat_block_truncate_page(inode, attr->ia_size);
537 if (error)
538 goto out;
539 down_write(&MSDOS_I(inode)->truncate_lock);
540 truncate_setsize(inode, attr->ia_size);
541 fat_truncate_blocks(inode, attr->ia_size);
542 up_write(&MSDOS_I(inode)->truncate_lock);
543 }
544
545 /*
546 * setattr_copy can't truncate these appropriately, so we'll
547 * copy them ourselves
548 */
549 if (attr->ia_valid & ATTR_ATIME)
550 fat_truncate_time(inode, &attr->ia_atime, S_ATIME);
551 if (attr->ia_valid & ATTR_CTIME)
552 fat_truncate_time(inode, &attr->ia_ctime, S_CTIME);
553 if (attr->ia_valid & ATTR_MTIME)
554 fat_truncate_time(inode, &attr->ia_mtime, S_MTIME);
555 attr->ia_valid &= ~(ATTR_ATIME|ATTR_CTIME|ATTR_MTIME);
556
557 setattr_copy(inode, attr);
558 mark_inode_dirty(inode);
559 out:
560 return error;
561 }
562 EXPORT_SYMBOL_GPL(fat_setattr);
563
564 const struct inode_operations fat_file_inode_operations = {
565 .setattr = fat_setattr,
566 .getattr = fat_getattr,
567 .update_time = fat_update_time,
568 };
Linux with added FPC-III support