fs/exfat/file.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
  */

 #include <linux/slab.h>
 #include <linux/cred.h>
 #include <linux/buffer_head.h>
 #include <linux/blkdev.h>

 #include "exfat_raw.h"
 #include "exfat_fs.h"

 static int exfat_cont_expand(struct inode *inode, loff_t size)
 {
 	struct address_space *mapping = inode->i_mapping;
 	loff_t start = i_size_read(inode), count = size - i_size_read(inode);
 	int err, err2;

 	err = generic_cont_expand_simple(inode, size);
 	if (err)
 		return err;

 	inode->i_ctime = inode->i_mtime = current_time(inode);
 	mark_inode_dirty(inode);

 	if (!IS_SYNC(inode))
 		return 0;

 	err = filemap_fdatawrite_range(mapping, start, start + count - 1);
 	err2 = sync_mapping_buffers(mapping);
 	if (!err)
 		err = err2;
 	err2 = write_inode_now(inode, 1);
 	if (!err)
 		err = err2;
 	if (err)
 		return err;

 	return filemap_fdatawait_range(mapping, start, start + count - 1);
 }

 static bool exfat_allow_set_time(struct exfat_sb_info *sbi, struct inode *inode)
 {
 	mode_t allow_utime = sbi->options.allow_utime;

 	if (!uid_eq(current_fsuid(), inode->i_uid)) {
 		if (in_group_p(inode->i_gid))
 			allow_utime >>= 3;
 		if (allow_utime & MAY_WRITE)
 			return true;
 	}

 	/* use a default check */
 	return false;
 }

 static int exfat_sanitize_mode(const struct exfat_sb_info *sbi,
 		struct inode *inode, umode_t *mode_ptr)
 {
 	mode_t i_mode, mask, perm;

 	i_mode = inode->i_mode;

 	mask = (S_ISREG(i_mode) || S_ISLNK(i_mode)) ?
 		sbi->options.fs_fmask : sbi->options.fs_dmask;
 	perm = *mode_ptr & ~(S_IFMT | mask);

 	/* Of the r and x bits, all (subject to umask) must be present.*/
 	if ((perm & 0555) != (i_mode & 0555))
 		return -EPERM;

 	if (exfat_mode_can_hold_ro(inode)) {
 		/*
 		 * Of the w bits, either all (subject to umask) or none must
 		 * be present.
 		 */
 		if ((perm & 0222) && ((perm & 0222) != (0222 & ~mask)))
 			return -EPERM;
 	} else {
 		/*
 		 * If exfat_mode_can_hold_ro(inode) is false, can't change
 		 * w bits.
 		 */
 		if ((perm & 0222) != (0222 & ~mask))
 			return -EPERM;
 	}

 	*mode_ptr &= S_IFMT | perm;

 	return 0;
 }

 /* resize the file length */
 int __exfat_truncate(struct inode *inode, loff_t new_size)
 {
 	unsigned int num_clusters_new, num_clusters_phys;
 	unsigned int last_clu = EXFAT_FREE_CLUSTER;
 	struct exfat_chain clu;
 	struct super_block *sb = inode->i_sb;
 	struct exfat_sb_info *sbi = EXFAT_SB(sb);
 	struct exfat_inode_info *ei = EXFAT_I(inode);
 	int evict = (ei->dir.dir == DIR_DELETED) ? 1 : 0;

 	/* check if the given file ID is opened */
 	if (ei->type != TYPE_FILE && ei->type != TYPE_DIR)
 		return -EPERM;

 	exfat_set_vol_flags(sb, VOL_DIRTY);

 	num_clusters_new = EXFAT_B_TO_CLU_ROUND_UP(i_size_read(inode), sbi);
 	num_clusters_phys =
 		EXFAT_B_TO_CLU_ROUND_UP(EXFAT_I(inode)->i_size_ondisk, sbi);

 	exfat_chain_set(&clu, ei->start_clu, num_clusters_phys, ei->flags);

 	if (new_size > 0) {
 		/*
 		 * Truncate FAT chain num_clusters after the first cluster
 		 * num_clusters = min(new, phys);
 		 */
 		unsigned int num_clusters =
 			min(num_clusters_new, num_clusters_phys);

 		/*
 		 * Follow FAT chain
 		 * (defensive coding - works fine even with corrupted FAT table
 		 */
 		if (clu.flags == ALLOC_NO_FAT_CHAIN) {
 			clu.dir += num_clusters;
 			clu.size -= num_clusters;
 		} else {
 			while (num_clusters > 0) {
 				last_clu = clu.dir;
 				if (exfat_get_next_cluster(sb, &(clu.dir)))
 					return -EIO;

 				num_clusters--;
 				clu.size--;
 			}
 		}
 	} else {
 		ei->flags = ALLOC_NO_FAT_CHAIN;
 		ei->start_clu = EXFAT_EOF_CLUSTER;
 	}

 	i_size_write(inode, new_size);

 	if (ei->type == TYPE_FILE)
 		ei->attr |= ATTR_ARCHIVE;

 	/* update the directory entry */
 	if (!evict) {
 		struct timespec64 ts;
 		struct exfat_dentry *ep, *ep2;
 		struct exfat_entry_set_cache *es;

 		es = exfat_get_dentry_set(sb, &(ei->dir), ei->entry,
 				ES_ALL_ENTRIES);
 		if (!es)
 			return -EIO;
 		ep = exfat_get_dentry_cached(es, 0);
 		ep2 = exfat_get_dentry_cached(es, 1);

 		ts = current_time(inode);
 		exfat_set_entry_time(sbi, &ts,
 				&ep->dentry.file.modify_tz,
 				&ep->dentry.file.modify_time,
 				&ep->dentry.file.modify_date,
 				&ep->dentry.file.modify_time_cs);
 		ep->dentry.file.attr = cpu_to_le16(ei->attr);

 		/* File size should be zero if there is no cluster allocated */
 		if (ei->start_clu == EXFAT_EOF_CLUSTER) {
 			ep2->dentry.stream.valid_size = 0;
 			ep2->dentry.stream.size = 0;
 		} else {
 			ep2->dentry.stream.valid_size = cpu_to_le64(new_size);
 			ep2->dentry.stream.size = ep->dentry.stream.valid_size;
 		}

 		if (new_size == 0) {
 			/* Any directory can not be truncated to zero */
 			WARN_ON(ei->type != TYPE_FILE);

 			ep2->dentry.stream.flags = ALLOC_FAT_CHAIN;
 			ep2->dentry.stream.start_clu = EXFAT_FREE_CLUSTER;
 		}

 		exfat_update_dir_chksum_with_entry_set(es);
 		exfat_free_dentry_set(es, inode_needs_sync(inode));
 	}

 	/* cut off from the FAT chain */
 	if (ei->flags == ALLOC_FAT_CHAIN && last_clu != EXFAT_FREE_CLUSTER &&
 			last_clu != EXFAT_EOF_CLUSTER) {
 		if (exfat_ent_set(sb, last_clu, EXFAT_EOF_CLUSTER))
 			return -EIO;
 	}

 	/* invalidate cache and free the clusters */
 	/* clear exfat cache */
 	exfat_cache_inval_inode(inode);

 	/* hint information */
 	ei->hint_bmap.off = EXFAT_EOF_CLUSTER;
 	ei->hint_bmap.clu = EXFAT_EOF_CLUSTER;
 	if (ei->rwoffset > new_size)
 		ei->rwoffset = new_size;

 	/* hint_stat will be used if this is directory. */
 	ei->hint_stat.eidx = 0;
 	ei->hint_stat.clu = ei->start_clu;
 	ei->hint_femp.eidx = EXFAT_HINT_NONE;

 	/* free the clusters */
 	if (exfat_free_cluster(inode, &clu))
 		return -EIO;

 	exfat_set_vol_flags(sb, VOL_CLEAN);

 	return 0;
 }

 void exfat_truncate(struct inode *inode, loff_t size)
 {
 	struct super_block *sb = inode->i_sb;
 	struct exfat_sb_info *sbi = EXFAT_SB(sb);
 	unsigned int blocksize = 1 << inode->i_blkbits;
 	loff_t aligned_size;
 	int err;

 	mutex_lock(&sbi->s_lock);
 	if (EXFAT_I(inode)->start_clu == 0) {
 		/*
 		 * Empty start_clu != ~0 (not allocated)
 		 */
 		exfat_fs_error(sb, "tried to truncate zeroed cluster.");
 		goto write_size;
 	}

 	err = __exfat_truncate(inode, i_size_read(inode));
 	if (err)
 		goto write_size;

 	inode->i_ctime = inode->i_mtime = current_time(inode);
 	if (IS_DIRSYNC(inode))
 		exfat_sync_inode(inode);
 	else
 		mark_inode_dirty(inode);

 	inode->i_blocks = ((i_size_read(inode) + (sbi->cluster_size - 1)) &
 			~(sbi->cluster_size - 1)) >> inode->i_blkbits;
 write_size:
 	aligned_size = i_size_read(inode);
 	if (aligned_size & (blocksize - 1)) {
 		aligned_size |= (blocksize - 1);
 		aligned_size++;
 	}

 	if (EXFAT_I(inode)->i_size_ondisk > i_size_read(inode))
 		EXFAT_I(inode)->i_size_ondisk = aligned_size;

 	if (EXFAT_I(inode)->i_size_aligned > i_size_read(inode))
 		EXFAT_I(inode)->i_size_aligned = aligned_size;
 	mutex_unlock(&sbi->s_lock);
 }

 int exfat_getattr(const struct path *path, struct kstat *stat,
 		unsigned int request_mask, unsigned int query_flags)
 {
 	struct inode *inode = d_backing_inode(path->dentry);
 	struct exfat_inode_info *ei = EXFAT_I(inode);

 	generic_fillattr(inode, stat);
 	exfat_truncate_atime(&stat->atime);
 	stat->result_mask |= STATX_BTIME;
 	stat->btime.tv_sec = ei->i_crtime.tv_sec;
 	stat->btime.tv_nsec = ei->i_crtime.tv_nsec;
 	stat->blksize = EXFAT_SB(inode->i_sb)->cluster_size;
 	return 0;
 }

 int exfat_setattr(struct dentry *dentry, struct iattr *attr)
 {
 	struct exfat_sb_info *sbi = EXFAT_SB(dentry->d_sb);
 	struct inode *inode = dentry->d_inode;
 	unsigned int ia_valid;
 	int error;

 	if ((attr->ia_valid & ATTR_SIZE) &&
 	    attr->ia_size > i_size_read(inode)) {
 		error = exfat_cont_expand(inode, attr->ia_size);
 		if (error || attr->ia_valid == ATTR_SIZE)
 			return error;
 		attr->ia_valid &= ~ATTR_SIZE;
 	}

 	/* Check for setting the inode time. */
 	ia_valid = attr->ia_valid;
 	if ((ia_valid & (ATTR_MTIME_SET | ATTR_ATIME_SET | ATTR_TIMES_SET)) &&
 	    exfat_allow_set_time(sbi, inode)) {
 		attr->ia_valid &= ~(ATTR_MTIME_SET | ATTR_ATIME_SET |
 				ATTR_TIMES_SET);
 	}

 	error = setattr_prepare(dentry, attr);
 	attr->ia_valid = ia_valid;
 	if (error)
 		goto out;

 	if (((attr->ia_valid & ATTR_UID) &&
 	     !uid_eq(attr->ia_uid, sbi->options.fs_uid)) ||
 	    ((attr->ia_valid & ATTR_GID) &&
 	     !gid_eq(attr->ia_gid, sbi->options.fs_gid)) ||
 	    ((attr->ia_valid & ATTR_MODE) &&
 	     (attr->ia_mode & ~(S_IFREG | S_IFLNK | S_IFDIR | 0777)))) {
 		error = -EPERM;
 		goto out;
 	}

 	/*
 	 * We don't return -EPERM here. Yes, strange, but this is too
 	 * old behavior.
 	 */
 	if (attr->ia_valid & ATTR_MODE) {
 		if (exfat_sanitize_mode(sbi, inode, &attr->ia_mode) < 0)
 			attr->ia_valid &= ~ATTR_MODE;
 	}

 	if (attr->ia_valid & ATTR_SIZE) {
 		error = exfat_block_truncate_page(inode, attr->ia_size);
 		if (error)
 			goto out;

 		down_write(&EXFAT_I(inode)->truncate_lock);
 		truncate_setsize(inode, attr->ia_size);
 		exfat_truncate(inode, attr->ia_size);
 		up_write(&EXFAT_I(inode)->truncate_lock);
 	}

 	setattr_copy(inode, attr);
 	exfat_truncate_atime(&inode->i_atime);
 	mark_inode_dirty(inode);

 out:
 	return error;
 }

 int exfat_file_fsync(struct file *filp, loff_t start, loff_t end, int datasync)
 {
 	struct inode *inode = filp->f_mapping->host;
 	int err;

 	err = __generic_file_fsync(filp, start, end, datasync);
 	if (err)
 		return err;

 	err = sync_blockdev(inode->i_sb->s_bdev);
 	if (err)
 		return err;

 	return blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL);
 }

 const struct file_operations exfat_file_operations = {
 	.llseek		= generic_file_llseek,
 	.read_iter	= generic_file_read_iter,
 	.write_iter	= generic_file_write_iter,
 	.mmap		= generic_file_mmap,
 	.fsync		= exfat_file_fsync,
 	.splice_read	= generic_file_splice_read,
 	.splice_write	= iter_file_splice_write,
 };

 const struct inode_operations exfat_file_inode_operations = {
 	.setattr     = exfat_setattr,
 	.getattr     = exfat_getattr,
 };
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
	*/

	#include <linux/slab.h>
	#include <linux/cred.h>
	#include <linux/buffer_head.h>
	#include <linux/blkdev.h>

	#include "exfat_raw.h"
	#include "exfat_fs.h"

	static int exfat_cont_expand(struct inode *inode, loff_t size)
	{
	struct address_space *mapping = inode->i_mapping;
	loff_t start = i_size_read(inode), count = size - i_size_read(inode);
	int err, err2;

	err = generic_cont_expand_simple(inode, size);
	if (err)
	return err;

	inode->i_ctime = inode->i_mtime = current_time(inode);
	mark_inode_dirty(inode);

	if (!IS_SYNC(inode))
	return 0;

	err = filemap_fdatawrite_range(mapping, start, start + count - 1);
	err2 = sync_mapping_buffers(mapping);
	if (!err)
	err = err2;
	err2 = write_inode_now(inode, 1);
	if (!err)
	err = err2;
	if (err)
	return err;

	return filemap_fdatawait_range(mapping, start, start + count - 1);
	}

	static bool exfat_allow_set_time(struct exfat_sb_info sbi, struct inode inode)
	{
	mode_t allow_utime = sbi->options.allow_utime;

	if (!uid_eq(current_fsuid(), inode->i_uid)) {
	if (in_group_p(inode->i_gid))
	allow_utime >>= 3;
	if (allow_utime & MAY_WRITE)
	return true;
	}

	/* use a default check */
	return false;
	}

	static int exfat_sanitize_mode(const struct exfat_sb_info *sbi,
	struct inode inode, umode_t mode_ptr)
	{
	mode_t i_mode, mask, perm;

	i_mode = inode->i_mode;

	mask = (S_ISREG(i_mode) \|\| S_ISLNK(i_mode)) ?
	sbi->options.fs_fmask : sbi->options.fs_dmask;
	perm = *mode_ptr & ~(S_IFMT \| mask);

	/* Of the r and x bits, all (subject to umask) must be present.*/
	if ((perm & 0555) != (i_mode & 0555))
	return -EPERM;

	if (exfat_mode_can_hold_ro(inode)) {
	/*
	* Of the w bits, either all (subject to umask) or none must
	* be present.
	*/
	if ((perm & 0222) && ((perm & 0222) != (0222 & ~mask)))
	return -EPERM;
	} else {
	/*
	* If exfat_mode_can_hold_ro(inode) is false, can't change
	* w bits.
	*/
	if ((perm & 0222) != (0222 & ~mask))
	return -EPERM;
	}

	*mode_ptr &= S_IFMT \| perm;

	return 0;
	}

	/* resize the file length */
	int __exfat_truncate(struct inode *inode, loff_t new_size)
	{
	unsigned int num_clusters_new, num_clusters_phys;
	unsigned int last_clu = EXFAT_FREE_CLUSTER;
	struct exfat_chain clu;
	struct super_block *sb = inode->i_sb;
	struct exfat_sb_info *sbi = EXFAT_SB(sb);
	struct exfat_inode_info *ei = EXFAT_I(inode);
	int evict = (ei->dir.dir == DIR_DELETED) ? 1 : 0;

	/* check if the given file ID is opened */
	if (ei->type != TYPE_FILE && ei->type != TYPE_DIR)
	return -EPERM;

	exfat_set_vol_flags(sb, VOL_DIRTY);

	num_clusters_new = EXFAT_B_TO_CLU_ROUND_UP(i_size_read(inode), sbi);
	num_clusters_phys =
	EXFAT_B_TO_CLU_ROUND_UP(EXFAT_I(inode)->i_size_ondisk, sbi);

	exfat_chain_set(&clu, ei->start_clu, num_clusters_phys, ei->flags);

	if (new_size > 0) {
	/*
	* Truncate FAT chain num_clusters after the first cluster
	* num_clusters = min(new, phys);
	*/
	unsigned int num_clusters =
	min(num_clusters_new, num_clusters_phys);

	/*
	* Follow FAT chain
	* (defensive coding - works fine even with corrupted FAT table
	*/
	if (clu.flags == ALLOC_NO_FAT_CHAIN) {
	clu.dir += num_clusters;
	clu.size -= num_clusters;
	} else {
	while (num_clusters > 0) {
	last_clu = clu.dir;
	if (exfat_get_next_cluster(sb, &(clu.dir)))
	return -EIO;

	num_clusters--;
	clu.size--;
	}
	}
	} else {
	ei->flags = ALLOC_NO_FAT_CHAIN;
	ei->start_clu = EXFAT_EOF_CLUSTER;
	}

	i_size_write(inode, new_size);

	if (ei->type == TYPE_FILE)
	ei->attr \|= ATTR_ARCHIVE;

	/* update the directory entry */
	if (!evict) {
	struct timespec64 ts;
	struct exfat_dentry ep, ep2;
	struct exfat_entry_set_cache *es;

	es = exfat_get_dentry_set(sb, &(ei->dir), ei->entry,
	ES_ALL_ENTRIES);
	if (!es)
	return -EIO;
	ep = exfat_get_dentry_cached(es, 0);
	ep2 = exfat_get_dentry_cached(es, 1);

	ts = current_time(inode);
	exfat_set_entry_time(sbi, &ts,
	&ep->dentry.file.modify_tz,
	&ep->dentry.file.modify_time,
	&ep->dentry.file.modify_date,
	&ep->dentry.file.modify_time_cs);
	ep->dentry.file.attr = cpu_to_le16(ei->attr);

	/* File size should be zero if there is no cluster allocated */
	if (ei->start_clu == EXFAT_EOF_CLUSTER) {
	ep2->dentry.stream.valid_size = 0;
	ep2->dentry.stream.size = 0;
	} else {
	ep2->dentry.stream.valid_size = cpu_to_le64(new_size);
	ep2->dentry.stream.size = ep->dentry.stream.valid_size;
	}

	if (new_size == 0) {
	/* Any directory can not be truncated to zero */
	WARN_ON(ei->type != TYPE_FILE);

	ep2->dentry.stream.flags = ALLOC_FAT_CHAIN;
	ep2->dentry.stream.start_clu = EXFAT_FREE_CLUSTER;
	}

	exfat_update_dir_chksum_with_entry_set(es);
	exfat_free_dentry_set(es, inode_needs_sync(inode));
	}

	/* cut off from the FAT chain */
	if (ei->flags == ALLOC_FAT_CHAIN && last_clu != EXFAT_FREE_CLUSTER &&
	last_clu != EXFAT_EOF_CLUSTER) {
	if (exfat_ent_set(sb, last_clu, EXFAT_EOF_CLUSTER))
	return -EIO;
	}

	/* invalidate cache and free the clusters */
	/* clear exfat cache */
	exfat_cache_inval_inode(inode);

	/* hint information */
	ei->hint_bmap.off = EXFAT_EOF_CLUSTER;
	ei->hint_bmap.clu = EXFAT_EOF_CLUSTER;
	if (ei->rwoffset > new_size)
	ei->rwoffset = new_size;

	/* hint_stat will be used if this is directory. */
	ei->hint_stat.eidx = 0;
	ei->hint_stat.clu = ei->start_clu;
	ei->hint_femp.eidx = EXFAT_HINT_NONE;

	/* free the clusters */
	if (exfat_free_cluster(inode, &clu))
	return -EIO;

	exfat_set_vol_flags(sb, VOL_CLEAN);

	return 0;
	}

	void exfat_truncate(struct inode *inode, loff_t size)
	{
	struct super_block *sb = inode->i_sb;
	struct exfat_sb_info *sbi = EXFAT_SB(sb);
	unsigned int blocksize = 1 << inode->i_blkbits;
	loff_t aligned_size;
	int err;

	mutex_lock(&sbi->s_lock);
	if (EXFAT_I(inode)->start_clu == 0) {
	/*
	* Empty start_clu != ~0 (not allocated)
	*/
	exfat_fs_error(sb, "tried to truncate zeroed cluster.");
	goto write_size;
	}

	err = __exfat_truncate(inode, i_size_read(inode));
	if (err)
	goto write_size;

	inode->i_ctime = inode->i_mtime = current_time(inode);
	if (IS_DIRSYNC(inode))
	exfat_sync_inode(inode);
	else
	mark_inode_dirty(inode);

	inode->i_blocks = ((i_size_read(inode) + (sbi->cluster_size - 1)) &
	~(sbi->cluster_size - 1)) >> inode->i_blkbits;
	write_size:
	aligned_size = i_size_read(inode);
	if (aligned_size & (blocksize - 1)) {
	aligned_size \|= (blocksize - 1);
	aligned_size++;
	}

	if (EXFAT_I(inode)->i_size_ondisk > i_size_read(inode))
	EXFAT_I(inode)->i_size_ondisk = aligned_size;

	if (EXFAT_I(inode)->i_size_aligned > i_size_read(inode))
	EXFAT_I(inode)->i_size_aligned = aligned_size;
	mutex_unlock(&sbi->s_lock);
	}

	int exfat_getattr(const struct path path, struct kstat stat,
	unsigned int request_mask, unsigned int query_flags)
	{
	struct inode *inode = d_backing_inode(path->dentry);
	struct exfat_inode_info *ei = EXFAT_I(inode);

	generic_fillattr(inode, stat);
	exfat_truncate_atime(&stat->atime);
	stat->result_mask \|= STATX_BTIME;
	stat->btime.tv_sec = ei->i_crtime.tv_sec;
	stat->btime.tv_nsec = ei->i_crtime.tv_nsec;
	stat->blksize = EXFAT_SB(inode->i_sb)->cluster_size;
	return 0;
	}

	int exfat_setattr(struct dentry dentry, struct iattr attr)
	{
	struct exfat_sb_info *sbi = EXFAT_SB(dentry->d_sb);
	struct inode *inode = dentry->d_inode;
	unsigned int ia_valid;
	int error;

	if ((attr->ia_valid & ATTR_SIZE) &&
	attr->ia_size > i_size_read(inode)) {
	error = exfat_cont_expand(inode, attr->ia_size);
	if (error \|\| attr->ia_valid == ATTR_SIZE)
	return error;
	attr->ia_valid &= ~ATTR_SIZE;
	}

	/* Check for setting the inode time. */
	ia_valid = attr->ia_valid;
	if ((ia_valid & (ATTR_MTIME_SET \| ATTR_ATIME_SET \| ATTR_TIMES_SET)) &&
	exfat_allow_set_time(sbi, inode)) {
	attr->ia_valid &= ~(ATTR_MTIME_SET \| ATTR_ATIME_SET \|
	ATTR_TIMES_SET);
	}

	error = setattr_prepare(dentry, attr);
	attr->ia_valid = ia_valid;
	if (error)
	goto out;

	if (((attr->ia_valid & ATTR_UID) &&
	!uid_eq(attr->ia_uid, sbi->options.fs_uid)) \|\|
	((attr->ia_valid & ATTR_GID) &&
	!gid_eq(attr->ia_gid, sbi->options.fs_gid)) \|\|
	((attr->ia_valid & ATTR_MODE) &&
	(attr->ia_mode & ~(S_IFREG \| S_IFLNK \| S_IFDIR \| 0777)))) {
	error = -EPERM;
	goto out;
	}

	/*
	* We don't return -EPERM here. Yes, strange, but this is too
	* old behavior.
	*/
	if (attr->ia_valid & ATTR_MODE) {
	if (exfat_sanitize_mode(sbi, inode, &attr->ia_mode) < 0)
	attr->ia_valid &= ~ATTR_MODE;
	}

	if (attr->ia_valid & ATTR_SIZE) {
	error = exfat_block_truncate_page(inode, attr->ia_size);
	if (error)
	goto out;

	down_write(&EXFAT_I(inode)->truncate_lock);
	truncate_setsize(inode, attr->ia_size);
	exfat_truncate(inode, attr->ia_size);
	up_write(&EXFAT_I(inode)->truncate_lock);
	}

	setattr_copy(inode, attr);
	exfat_truncate_atime(&inode->i_atime);
	mark_inode_dirty(inode);

	out:
	return error;
	}

	int exfat_file_fsync(struct file *filp, loff_t start, loff_t end, int datasync)
	{
	struct inode *inode = filp->f_mapping->host;
	int err;

	err = __generic_file_fsync(filp, start, end, datasync);
	if (err)
	return err;

	err = sync_blockdev(inode->i_sb->s_bdev);
	if (err)
	return err;

	return blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL);
	}

	const struct file_operations exfat_file_operations = {
	.llseek = generic_file_llseek,
	.read_iter = generic_file_read_iter,
	.write_iter = generic_file_write_iter,
	.mmap = generic_file_mmap,
	.fsync = exfat_file_fsync,
	.splice_read = generic_file_splice_read,
	.splice_write = iter_file_splice_write,
	};

	const struct inode_operations exfat_file_inode_operations = {
	.setattr = exfat_setattr,
	.getattr = exfat_getattr,
	};