1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
4 */
5
6 #include <linux/slab.h>
7 #include <linux/compat.h>
8 #include <linux/cred.h>
9 #include <linux/buffer_head.h>
10 #include <linux/blkdev.h>
11 #include <linux/fsnotify.h>
12 #include <linux/security.h>
13 #include <linux/msdos_fs.h>
14 #include <linux/writeback.h>
15 #include <linux/filelock.h>
16
17 #include "exfat_raw.h"
18 #include "exfat_fs.h"
19
exfat_cont_expand(struct inode * inode,loff_t size)20 static int exfat_cont_expand(struct inode *inode, loff_t size)
21 {
22 int ret;
23 unsigned int num_clusters, new_num_clusters, last_clu;
24 struct exfat_inode_info *ei = EXFAT_I(inode);
25 struct super_block *sb = inode->i_sb;
26 struct exfat_sb_info *sbi = EXFAT_SB(sb);
27 struct exfat_chain clu;
28
29 truncate_pagecache(inode, i_size_read(inode));
30
31 ret = inode_newsize_ok(inode, size);
32 if (ret)
33 return ret;
34
35 num_clusters = EXFAT_B_TO_CLU(exfat_ondisk_size(inode), sbi);
36 new_num_clusters = EXFAT_B_TO_CLU_ROUND_UP(size, sbi);
37
38 if (new_num_clusters == num_clusters)
39 goto out;
40
41 if (num_clusters) {
42 exfat_chain_set(&clu, ei->start_clu, num_clusters, ei->flags);
43 ret = exfat_find_last_cluster(sb, &clu, &last_clu);
44 if (ret)
45 return ret;
46
47 clu.dir = last_clu + 1;
48 } else {
49 last_clu = EXFAT_EOF_CLUSTER;
50 clu.dir = EXFAT_EOF_CLUSTER;
51 }
52
53 clu.size = 0;
54 clu.flags = ei->flags;
55
56 ret = exfat_alloc_cluster(inode, new_num_clusters - num_clusters,
57 &clu, inode_needs_sync(inode));
58 if (ret)
59 return ret;
60
61 /* Append new clusters to chain */
62 if (num_clusters) {
63 if (clu.flags != ei->flags)
64 if (exfat_chain_cont_cluster(sb, ei->start_clu, num_clusters))
65 goto free_clu;
66
67 if (clu.flags == ALLOC_FAT_CHAIN)
68 if (exfat_ent_set(sb, last_clu, clu.dir))
69 goto free_clu;
70 } else
71 ei->start_clu = clu.dir;
72
73 ei->flags = clu.flags;
74
75 out:
76 inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
77 /* Expanded range not zeroed, do not update valid_size */
78 i_size_write(inode, size);
79
80 inode->i_blocks = round_up(size, sbi->cluster_size) >> 9;
81 mark_inode_dirty(inode);
82
83 if (IS_SYNC(inode))
84 return write_inode_now(inode, 1);
85
86 return 0;
87
88 free_clu:
89 exfat_free_cluster(inode, &clu);
90 return -EIO;
91 }
92
exfat_allow_set_time(struct mnt_idmap * idmap,struct exfat_sb_info * sbi,struct inode * inode)93 static bool exfat_allow_set_time(struct mnt_idmap *idmap,
94 struct exfat_sb_info *sbi, struct inode *inode)
95 {
96 mode_t allow_utime = sbi->options.allow_utime;
97
98 if (!vfsuid_eq_kuid(i_uid_into_vfsuid(idmap, inode),
99 current_fsuid())) {
100 if (vfsgid_in_group_p(i_gid_into_vfsgid(idmap, inode)))
101 allow_utime >>= 3;
102 if (allow_utime & MAY_WRITE)
103 return true;
104 }
105
106 /* use a default check */
107 return false;
108 }
109
exfat_sanitize_mode(const struct exfat_sb_info * sbi,struct inode * inode,umode_t * mode_ptr)110 static int exfat_sanitize_mode(const struct exfat_sb_info *sbi,
111 struct inode *inode, umode_t *mode_ptr)
112 {
113 mode_t i_mode, mask, perm;
114
115 i_mode = inode->i_mode;
116
117 mask = (S_ISREG(i_mode) || S_ISLNK(i_mode)) ?
118 sbi->options.fs_fmask : sbi->options.fs_dmask;
119 perm = *mode_ptr & ~(S_IFMT | mask);
120
121 /* Of the r and x bits, all (subject to umask) must be present.*/
122 if ((perm & 0555) != (i_mode & 0555))
123 return -EPERM;
124
125 if (exfat_mode_can_hold_ro(inode)) {
126 /*
127 * Of the w bits, either all (subject to umask) or none must
128 * be present.
129 */
130 if ((perm & 0222) && ((perm & 0222) != (0222 & ~mask)))
131 return -EPERM;
132 } else {
133 /*
134 * If exfat_mode_can_hold_ro(inode) is false, can't change
135 * w bits.
136 */
137 if ((perm & 0222) != (0222 & ~mask))
138 return -EPERM;
139 }
140
141 *mode_ptr &= S_IFMT | perm;
142
143 return 0;
144 }
145
146 /* resize the file length */
__exfat_truncate(struct inode * inode)147 int __exfat_truncate(struct inode *inode)
148 {
149 unsigned int num_clusters_new, num_clusters_phys;
150 unsigned int last_clu = EXFAT_FREE_CLUSTER;
151 struct exfat_chain clu;
152 struct super_block *sb = inode->i_sb;
153 struct exfat_sb_info *sbi = EXFAT_SB(sb);
154 struct exfat_inode_info *ei = EXFAT_I(inode);
155
156 /* check if the given file ID is opened */
157 if (ei->type != TYPE_FILE && ei->type != TYPE_DIR)
158 return -EPERM;
159
160 exfat_set_volume_dirty(sb);
161
162 num_clusters_new = EXFAT_B_TO_CLU_ROUND_UP(i_size_read(inode), sbi);
163 num_clusters_phys = EXFAT_B_TO_CLU(exfat_ondisk_size(inode), sbi);
164
165 exfat_chain_set(&clu, ei->start_clu, num_clusters_phys, ei->flags);
166
167 if (i_size_read(inode) > 0) {
168 /*
169 * Truncate FAT chain num_clusters after the first cluster
170 * num_clusters = min(new, phys);
171 */
172 unsigned int num_clusters =
173 min(num_clusters_new, num_clusters_phys);
174
175 /*
176 * Follow FAT chain
177 * (defensive coding - works fine even with corrupted FAT table
178 */
179 if (clu.flags == ALLOC_NO_FAT_CHAIN) {
180 clu.dir += num_clusters;
181 clu.size -= num_clusters;
182 } else {
183 while (num_clusters > 0) {
184 last_clu = clu.dir;
185 if (exfat_get_next_cluster(sb, &(clu.dir)))
186 return -EIO;
187
188 num_clusters--;
189 clu.size--;
190 }
191 }
192 } else {
193 ei->flags = ALLOC_NO_FAT_CHAIN;
194 ei->start_clu = EXFAT_EOF_CLUSTER;
195 }
196
197 if (i_size_read(inode) < ei->valid_size)
198 ei->valid_size = i_size_read(inode);
199
200 if (ei->type == TYPE_FILE)
201 ei->attr |= EXFAT_ATTR_ARCHIVE;
202
203 /*
204 * update the directory entry
205 *
206 * If the directory entry is updated by mark_inode_dirty(), the
207 * directory entry will be written after a writeback cycle of
208 * updating the bitmap/FAT, which may result in clusters being
209 * freed but referenced by the directory entry in the event of a
210 * sudden power failure.
211 * __exfat_write_inode() is called for directory entry, bitmap
212 * and FAT to be written in a same writeback.
213 */
214 if (__exfat_write_inode(inode, inode_needs_sync(inode)))
215 return -EIO;
216
217 /* cut off from the FAT chain */
218 if (ei->flags == ALLOC_FAT_CHAIN && last_clu != EXFAT_FREE_CLUSTER &&
219 last_clu != EXFAT_EOF_CLUSTER) {
220 if (exfat_ent_set(sb, last_clu, EXFAT_EOF_CLUSTER))
221 return -EIO;
222 }
223
224 /* invalidate cache and free the clusters */
225 /* clear exfat cache */
226 exfat_cache_inval_inode(inode);
227
228 /* hint information */
229 ei->hint_bmap.off = EXFAT_EOF_CLUSTER;
230 ei->hint_bmap.clu = EXFAT_EOF_CLUSTER;
231
232 /* hint_stat will be used if this is directory. */
233 ei->hint_stat.eidx = 0;
234 ei->hint_stat.clu = ei->start_clu;
235 ei->hint_femp.eidx = EXFAT_HINT_NONE;
236
237 /* free the clusters */
238 if (exfat_free_cluster(inode, &clu))
239 return -EIO;
240
241 return 0;
242 }
243
exfat_truncate(struct inode * inode)244 void exfat_truncate(struct inode *inode)
245 {
246 struct super_block *sb = inode->i_sb;
247 struct exfat_sb_info *sbi = EXFAT_SB(sb);
248 struct exfat_inode_info *ei = EXFAT_I(inode);
249 int err;
250
251 mutex_lock(&sbi->s_lock);
252 if (ei->start_clu == 0) {
253 /*
254 * Empty start_clu != ~0 (not allocated)
255 */
256 exfat_fs_error(sb, "tried to truncate zeroed cluster.");
257 goto write_size;
258 }
259
260 err = __exfat_truncate(inode);
261 if (err)
262 goto write_size;
263
264 inode->i_blocks = round_up(i_size_read(inode), sbi->cluster_size) >> 9;
265 write_size:
266 mutex_unlock(&sbi->s_lock);
267 }
268
exfat_getattr(struct mnt_idmap * idmap,const struct path * path,struct kstat * stat,unsigned int request_mask,unsigned int query_flags)269 int exfat_getattr(struct mnt_idmap *idmap, const struct path *path,
270 struct kstat *stat, unsigned int request_mask,
271 unsigned int query_flags)
272 {
273 struct inode *inode = d_backing_inode(path->dentry);
274 struct exfat_inode_info *ei = EXFAT_I(inode);
275
276 generic_fillattr(idmap, request_mask, inode, stat);
277 exfat_truncate_atime(&stat->atime);
278 stat->result_mask |= STATX_BTIME;
279 stat->btime.tv_sec = ei->i_crtime.tv_sec;
280 stat->btime.tv_nsec = ei->i_crtime.tv_nsec;
281 stat->blksize = EXFAT_SB(inode->i_sb)->cluster_size;
282 return 0;
283 }
284
exfat_setattr(struct mnt_idmap * idmap,struct dentry * dentry,struct iattr * attr)285 int exfat_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
286 struct iattr *attr)
287 {
288 struct exfat_sb_info *sbi = EXFAT_SB(dentry->d_sb);
289 struct inode *inode = dentry->d_inode;
290 unsigned int ia_valid;
291 int error;
292
293 if (unlikely(exfat_forced_shutdown(inode->i_sb)))
294 return -EIO;
295
296 if ((attr->ia_valid & ATTR_SIZE) &&
297 attr->ia_size > i_size_read(inode)) {
298 error = exfat_cont_expand(inode, attr->ia_size);
299 if (error || attr->ia_valid == ATTR_SIZE)
300 return error;
301 attr->ia_valid &= ~ATTR_SIZE;
302 }
303
304 /* Check for setting the inode time. */
305 ia_valid = attr->ia_valid;
306 if ((ia_valid & (ATTR_MTIME_SET | ATTR_ATIME_SET | ATTR_TIMES_SET)) &&
307 exfat_allow_set_time(idmap, sbi, inode)) {
308 attr->ia_valid &= ~(ATTR_MTIME_SET | ATTR_ATIME_SET |
309 ATTR_TIMES_SET);
310 }
311
312 error = setattr_prepare(idmap, dentry, attr);
313 attr->ia_valid = ia_valid;
314 if (error)
315 goto out;
316
317 if (((attr->ia_valid & ATTR_UID) &&
318 (!uid_eq(from_vfsuid(idmap, i_user_ns(inode), attr->ia_vfsuid),
319 sbi->options.fs_uid))) ||
320 ((attr->ia_valid & ATTR_GID) &&
321 (!gid_eq(from_vfsgid(idmap, i_user_ns(inode), attr->ia_vfsgid),
322 sbi->options.fs_gid))) ||
323 ((attr->ia_valid & ATTR_MODE) &&
324 (attr->ia_mode & ~(S_IFREG | S_IFLNK | S_IFDIR | 0777)))) {
325 error = -EPERM;
326 goto out;
327 }
328
329 /*
330 * We don't return -EPERM here. Yes, strange, but this is too
331 * old behavior.
332 */
333 if (attr->ia_valid & ATTR_MODE) {
334 if (exfat_sanitize_mode(sbi, inode, &attr->ia_mode) < 0)
335 attr->ia_valid &= ~ATTR_MODE;
336 }
337
338 if (attr->ia_valid & ATTR_SIZE)
339 inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
340
341 setattr_copy(idmap, inode, attr);
342 exfat_truncate_inode_atime(inode);
343
344 if (attr->ia_valid & ATTR_SIZE) {
345 error = exfat_block_truncate_page(inode, attr->ia_size);
346 if (error)
347 goto out;
348
349 down_write(&EXFAT_I(inode)->truncate_lock);
350 truncate_setsize(inode, attr->ia_size);
351
352 /*
353 * __exfat_write_inode() is called from exfat_truncate(), inode
354 * is already written by it, so mark_inode_dirty() is unneeded.
355 */
356 exfat_truncate(inode);
357 up_write(&EXFAT_I(inode)->truncate_lock);
358 } else
359 mark_inode_dirty(inode);
360
361 out:
362 return error;
363 }
364
365 /*
366 * modified ioctls from fat/file.c by Welmer Almesberger
367 */
exfat_ioctl_get_attributes(struct inode * inode,u32 __user * user_attr)368 static int exfat_ioctl_get_attributes(struct inode *inode, u32 __user *user_attr)
369 {
370 u32 attr;
371
372 inode_lock_shared(inode);
373 attr = exfat_make_attr(inode);
374 inode_unlock_shared(inode);
375
376 return put_user(attr, user_attr);
377 }
378
exfat_ioctl_set_attributes(struct file * file,u32 __user * user_attr)379 static int exfat_ioctl_set_attributes(struct file *file, u32 __user *user_attr)
380 {
381 struct inode *inode = file_inode(file);
382 struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb);
383 int is_dir = S_ISDIR(inode->i_mode);
384 u32 attr, oldattr;
385 struct iattr ia;
386 int err;
387
388 err = get_user(attr, user_attr);
389 if (err)
390 goto out;
391
392 err = mnt_want_write_file(file);
393 if (err)
394 goto out;
395 inode_lock(inode);
396
397 oldattr = exfat_make_attr(inode);
398
399 /*
400 * Mask attributes so we don't set reserved fields.
401 */
402 attr &= (EXFAT_ATTR_READONLY | EXFAT_ATTR_HIDDEN | EXFAT_ATTR_SYSTEM |
403 EXFAT_ATTR_ARCHIVE);
404 attr |= (is_dir ? EXFAT_ATTR_SUBDIR : 0);
405
406 /* Equivalent to a chmod() */
407 ia.ia_valid = ATTR_MODE | ATTR_CTIME;
408 ia.ia_ctime = current_time(inode);
409 if (is_dir)
410 ia.ia_mode = exfat_make_mode(sbi, attr, 0777);
411 else
412 ia.ia_mode = exfat_make_mode(sbi, attr, 0666 | (inode->i_mode & 0111));
413
414 /* The root directory has no attributes */
415 if (inode->i_ino == EXFAT_ROOT_INO && attr != EXFAT_ATTR_SUBDIR) {
416 err = -EINVAL;
417 goto out_unlock_inode;
418 }
419
420 if (((attr | oldattr) & EXFAT_ATTR_SYSTEM) &&
421 !capable(CAP_LINUX_IMMUTABLE)) {
422 err = -EPERM;
423 goto out_unlock_inode;
424 }
425
426 /*
427 * The security check is questionable... We single
428 * out the RO attribute for checking by the security
429 * module, just because it maps to a file mode.
430 */
431 err = security_inode_setattr(file_mnt_idmap(file),
432 file->f_path.dentry, &ia);
433 if (err)
434 goto out_unlock_inode;
435
436 /* This MUST be done before doing anything irreversible... */
437 err = exfat_setattr(file_mnt_idmap(file), file->f_path.dentry, &ia);
438 if (err)
439 goto out_unlock_inode;
440
441 fsnotify_change(file->f_path.dentry, ia.ia_valid);
442
443 exfat_save_attr(inode, attr);
444 mark_inode_dirty(inode);
445 out_unlock_inode:
446 inode_unlock(inode);
447 mnt_drop_write_file(file);
448 out:
449 return err;
450 }
451
exfat_ioctl_fitrim(struct inode * inode,unsigned long arg)452 static int exfat_ioctl_fitrim(struct inode *inode, unsigned long arg)
453 {
454 struct fstrim_range range;
455 int ret = 0;
456
457 if (!capable(CAP_SYS_ADMIN))
458 return -EPERM;
459
460 if (!bdev_max_discard_sectors(inode->i_sb->s_bdev))
461 return -EOPNOTSUPP;
462
463 if (copy_from_user(&range, (struct fstrim_range __user *)arg, sizeof(range)))
464 return -EFAULT;
465
466 range.minlen = max_t(unsigned int, range.minlen,
467 bdev_discard_granularity(inode->i_sb->s_bdev));
468
469 ret = exfat_trim_fs(inode, &range);
470 if (ret < 0)
471 return ret;
472
473 if (copy_to_user((struct fstrim_range __user *)arg, &range, sizeof(range)))
474 return -EFAULT;
475
476 return 0;
477 }
478
exfat_ioctl_shutdown(struct super_block * sb,unsigned long arg)479 static int exfat_ioctl_shutdown(struct super_block *sb, unsigned long arg)
480 {
481 u32 flags;
482
483 if (!capable(CAP_SYS_ADMIN))
484 return -EPERM;
485
486 if (get_user(flags, (__u32 __user *)arg))
487 return -EFAULT;
488
489 return exfat_force_shutdown(sb, flags);
490 }
491
exfat_ioctl_get_volume_label(struct super_block * sb,unsigned long arg)492 static int exfat_ioctl_get_volume_label(struct super_block *sb, unsigned long arg)
493 {
494 int ret;
495 char label[FSLABEL_MAX] = {0};
496 struct exfat_uni_name uniname;
497
498 ret = exfat_read_volume_label(sb, &uniname);
499 if (ret < 0)
500 return ret;
501
502 ret = exfat_utf16_to_nls(sb, &uniname, label, uniname.name_len);
503 if (ret < 0)
504 return ret;
505
506 if (copy_to_user((char __user *)arg, label, ret + 1))
507 return -EFAULT;
508
509 return 0;
510 }
511
exfat_ioctl_set_volume_label(struct super_block * sb,unsigned long arg)512 static int exfat_ioctl_set_volume_label(struct super_block *sb,
513 unsigned long arg)
514 {
515 int ret = 0, lossy, label_len;
516 char label[FSLABEL_MAX] = {0};
517 struct exfat_uni_name uniname;
518
519 if (!capable(CAP_SYS_ADMIN))
520 return -EPERM;
521
522 if (copy_from_user(label, (char __user *)arg, FSLABEL_MAX))
523 return -EFAULT;
524
525 memset(&uniname, 0, sizeof(uniname));
526 label_len = strnlen(label, FSLABEL_MAX - 1);
527 if (label[0]) {
528 ret = exfat_nls_to_utf16(sb, label, label_len,
529 &uniname, &lossy);
530 if (ret < 0)
531 return ret;
532 else if (lossy & NLS_NAME_LOSSY)
533 return -EINVAL;
534 }
535
536 uniname.name_len = ret;
537
538 return exfat_write_volume_label(sb, &uniname);
539 }
540
exfat_ioctl(struct file * filp,unsigned int cmd,unsigned long arg)541 long exfat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
542 {
543 struct inode *inode = file_inode(filp);
544 u32 __user *user_attr = (u32 __user *)arg;
545
546 switch (cmd) {
547 case FAT_IOCTL_GET_ATTRIBUTES:
548 return exfat_ioctl_get_attributes(inode, user_attr);
549 case FAT_IOCTL_SET_ATTRIBUTES:
550 return exfat_ioctl_set_attributes(filp, user_attr);
551 case EXFAT_IOC_SHUTDOWN:
552 return exfat_ioctl_shutdown(inode->i_sb, arg);
553 case FITRIM:
554 return exfat_ioctl_fitrim(inode, arg);
555 case FS_IOC_GETFSLABEL:
556 return exfat_ioctl_get_volume_label(inode->i_sb, arg);
557 case FS_IOC_SETFSLABEL:
558 return exfat_ioctl_set_volume_label(inode->i_sb, arg);
559 default:
560 return -ENOTTY;
561 }
562 }
563
564 #ifdef CONFIG_COMPAT
exfat_compat_ioctl(struct file * filp,unsigned int cmd,unsigned long arg)565 long exfat_compat_ioctl(struct file *filp, unsigned int cmd,
566 unsigned long arg)
567 {
568 return exfat_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
569 }
570 #endif
571
exfat_file_fsync(struct file * filp,loff_t start,loff_t end,int datasync)572 int exfat_file_fsync(struct file *filp, loff_t start, loff_t end, int datasync)
573 {
574 struct inode *inode = filp->f_mapping->host;
575 int err;
576
577 if (unlikely(exfat_forced_shutdown(inode->i_sb)))
578 return -EIO;
579
580 err = __generic_file_fsync(filp, start, end, datasync);
581 if (err)
582 return err;
583
584 err = sync_blockdev(inode->i_sb->s_bdev);
585 if (err)
586 return err;
587
588 return blkdev_issue_flush(inode->i_sb->s_bdev);
589 }
590
exfat_extend_valid_size(struct inode * inode,loff_t new_valid_size)591 static int exfat_extend_valid_size(struct inode *inode, loff_t new_valid_size)
592 {
593 int err;
594 loff_t pos;
595 struct exfat_inode_info *ei = EXFAT_I(inode);
596 struct address_space *mapping = inode->i_mapping;
597 const struct address_space_operations *ops = mapping->a_ops;
598
599 pos = ei->valid_size;
600 while (pos < new_valid_size) {
601 u32 len;
602 struct folio *folio;
603 unsigned long off;
604
605 len = PAGE_SIZE - (pos & (PAGE_SIZE - 1));
606 if (pos + len > new_valid_size)
607 len = new_valid_size - pos;
608
609 err = ops->write_begin(NULL, mapping, pos, len, &folio, NULL);
610 if (err)
611 goto out;
612
613 off = offset_in_folio(folio, pos);
614 folio_zero_new_buffers(folio, off, off + len);
615
616 err = ops->write_end(NULL, mapping, pos, len, len, folio, NULL);
617 if (err < 0)
618 goto out;
619 pos += len;
620
621 balance_dirty_pages_ratelimited(mapping);
622 cond_resched();
623 }
624
625 return 0;
626
627 out:
628 return err;
629 }
630
exfat_file_write_iter(struct kiocb * iocb,struct iov_iter * iter)631 static ssize_t exfat_file_write_iter(struct kiocb *iocb, struct iov_iter *iter)
632 {
633 ssize_t ret;
634 struct file *file = iocb->ki_filp;
635 struct inode *inode = file_inode(file);
636 struct exfat_inode_info *ei = EXFAT_I(inode);
637 loff_t pos = iocb->ki_pos;
638 loff_t valid_size;
639
640 if (unlikely(exfat_forced_shutdown(inode->i_sb)))
641 return -EIO;
642
643 inode_lock(inode);
644
645 if (pos > i_size_read(inode))
646 truncate_pagecache(inode, i_size_read(inode));
647
648 valid_size = ei->valid_size;
649
650 ret = generic_write_checks(iocb, iter);
651 if (ret <= 0)
652 goto unlock;
653
654 if (iocb->ki_flags & IOCB_DIRECT) {
655 unsigned long align = pos | iov_iter_alignment(iter);
656
657 if (!IS_ALIGNED(align, i_blocksize(inode)) &&
658 !IS_ALIGNED(align, bdev_logical_block_size(inode->i_sb->s_bdev))) {
659 ret = -EINVAL;
660 goto unlock;
661 }
662 }
663
664 if (pos > valid_size) {
665 ret = exfat_extend_valid_size(inode, pos);
666 if (ret < 0 && ret != -ENOSPC) {
667 exfat_err(inode->i_sb,
668 "write: fail to zero from %llu to %llu(%zd)",
669 valid_size, pos, ret);
670 }
671 if (ret < 0)
672 goto unlock;
673 }
674
675 ret = __generic_file_write_iter(iocb, iter);
676 if (ret < 0)
677 goto unlock;
678
679 inode_unlock(inode);
680
681 if (pos > valid_size)
682 pos = valid_size;
683
684 if (iocb->ki_pos > pos) {
685 ssize_t err = generic_write_sync(iocb, iocb->ki_pos - pos);
686
687 if (err < 0)
688 return err;
689 }
690
691 return ret;
692
693 unlock:
694 inode_unlock(inode);
695
696 return ret;
697 }
698
exfat_file_read_iter(struct kiocb * iocb,struct iov_iter * iter)699 static ssize_t exfat_file_read_iter(struct kiocb *iocb, struct iov_iter *iter)
700 {
701 struct inode *inode = file_inode(iocb->ki_filp);
702
703 if (unlikely(exfat_forced_shutdown(inode->i_sb)))
704 return -EIO;
705
706 return generic_file_read_iter(iocb, iter);
707 }
708
exfat_page_mkwrite(struct vm_fault * vmf)709 static vm_fault_t exfat_page_mkwrite(struct vm_fault *vmf)
710 {
711 int err;
712 struct inode *inode = file_inode(vmf->vma->vm_file);
713 struct exfat_inode_info *ei = EXFAT_I(inode);
714 loff_t new_valid_size;
715
716 if (!inode_trylock(inode))
717 return VM_FAULT_RETRY;
718
719 new_valid_size = ((loff_t)vmf->pgoff + 1) << PAGE_SHIFT;
720 new_valid_size = min(new_valid_size, i_size_read(inode));
721
722 if (ei->valid_size < new_valid_size) {
723 err = exfat_extend_valid_size(inode, new_valid_size);
724 if (err < 0) {
725 inode_unlock(inode);
726 return vmf_fs_error(err);
727 }
728 }
729
730 inode_unlock(inode);
731
732 return filemap_page_mkwrite(vmf);
733 }
734
735 static const struct vm_operations_struct exfat_file_vm_ops = {
736 .fault = filemap_fault,
737 .map_pages = filemap_map_pages,
738 .page_mkwrite = exfat_page_mkwrite,
739 };
740
exfat_file_mmap_prepare(struct vm_area_desc * desc)741 static int exfat_file_mmap_prepare(struct vm_area_desc *desc)
742 {
743 struct file *file = desc->file;
744
745 if (unlikely(exfat_forced_shutdown(file_inode(desc->file)->i_sb)))
746 return -EIO;
747
748 file_accessed(file);
749 desc->vm_ops = &exfat_file_vm_ops;
750 return 0;
751 }
752
exfat_splice_read(struct file * in,loff_t * ppos,struct pipe_inode_info * pipe,size_t len,unsigned int flags)753 static ssize_t exfat_splice_read(struct file *in, loff_t *ppos,
754 struct pipe_inode_info *pipe, size_t len, unsigned int flags)
755 {
756 if (unlikely(exfat_forced_shutdown(file_inode(in)->i_sb)))
757 return -EIO;
758
759 return filemap_splice_read(in, ppos, pipe, len, flags);
760 }
761
762 const struct file_operations exfat_file_operations = {
763 .llseek = generic_file_llseek,
764 .read_iter = exfat_file_read_iter,
765 .write_iter = exfat_file_write_iter,
766 .unlocked_ioctl = exfat_ioctl,
767 #ifdef CONFIG_COMPAT
768 .compat_ioctl = exfat_compat_ioctl,
769 #endif
770 .mmap_prepare = exfat_file_mmap_prepare,
771 .fsync = exfat_file_fsync,
772 .splice_read = exfat_splice_read,
773 .splice_write = iter_file_splice_write,
774 .setlease = generic_setlease,
775 };
776
777 const struct inode_operations exfat_file_inode_operations = {
778 .setattr = exfat_setattr,
779 .getattr = exfat_getattr,
780 };
781