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