file.c

  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
 19static 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
 74out:
 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
 87free_clu:
 88	exfat_free_cluster(inode, &clu);
 89	return -EIO;
 90}
 91
 92static 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
109static 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 */
146int __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
243void 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;
264write_size:
265	mutex_unlock(&sbi->s_lock);
266}
267
268int 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
284int 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
360out:
361	return error;
362}
363
364/*
365 * modified ioctls from fat/file.c by Welmer Almesberger
366 */
367static 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
378static 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);
444out_unlock_inode:
445	inode_unlock(inode);
446	mnt_drop_write_file(file);
447out:
448	return err;
449}
450
451static 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
478static 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
491static 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
511static 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
540long 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
564long 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
571int 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
590static 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
626out:
627	return err;
628}
629
630static 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
691unlock:
692	inode_unlock(inode);
693
694	return ret;
695}
696
697static 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
707static 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
736static 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
742static 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
754static 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
763const 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
777const struct inode_operations exfat_file_inode_operations = {
778	.setattr     = exfat_setattr,
779	.getattr     = exfat_getattr,
780};