fuse: copy_file_range needs to strip setuid bits and update timestamps

Like ->write_iter(), we update mtime and strip setuid of dst file before
copy and like ->read_iter(), we update atime of src file after copy.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Acked-by: Miklos Szeredi <miklos@szeredi.hu>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

fs/fuse/file.c

@@ -3155,6 +3155,10 @@ static ssize_t __fuse_copy_file_range(struct file *file_in, loff_t pos_in,
 
 	inode_lock(inode_out);
 
+	err = file_modified(file_out);
+	if (err)
+		goto out;
+
 	if (fc->writeback_cache) {
 		err = fuse_writeback_range(inode_out, pos_out, pos_out + len);
 		if (err)
@@ -3193,6 +3197,7 @@ static ssize_t __fuse_copy_file_range(struct file *file_in, loff_t pos_in,
 		clear_bit(FUSE_I_SIZE_UNSTABLE, &fi_out->state);
 
 	inode_unlock(inode_out);
+	file_accessed(file_in);
 
 	return err;
 }