Commit 2e94e5bb authored by Yuezhang Mo's avatar Yuezhang Mo Committed by Namjae Jeon
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exfat: fix file being changed by unaligned direct write 



Unaligned direct writes are invalid and should return an error
without making any changes, rather than extending ->valid_size
and then returning an error. Therefore, alignment checking is
required before extending ->valid_size.

Fixes: 11a347fb ("exfat: change to get file size from DataLength")
Signed-off-by: default avatarYuezhang Mo <Yuezhang.Mo@sony.com>
Co-developed-by: default avatarNamjae Jeon <linkinjeon@kernel.org>
Signed-off-by: default avatarNamjae Jeon <linkinjeon@kernel.org>
parent 02dffe9a

fs/exfat/file.c

+10 −0
Original line number Diff line number Diff line
@@ -584,6 +584,16 @@ static ssize_t exfat_file_write_iter(struct kiocb *iocb, struct iov_iter *iter) 
	if (ret < 0)

		goto unlock;



	if (iocb->ki_flags & IOCB_DIRECT) {

		unsigned long align = pos | iov_iter_alignment(iter);



		if (!IS_ALIGNED(align, i_blocksize(inode)) &&

		    !IS_ALIGNED(align, bdev_logical_block_size(inode->i_sb->s_bdev))) {

			ret = -EINVAL;

			goto unlock;

		}

	}



	if (pos > valid_size) {

		ret = exfat_extend_valid_size(file, pos);

		if (ret < 0 && ret != -ENOSPC) {