From: Eric Biggers <ebiggers@xxxxxxxxxx> The 'lend' argument of filemap_write_and_wait_range() is inclusive, so we need to subtract 1 from pos + count. Note that 'count' is guaranteed to be nonzero since ext4_file_read_iter() returns early when given a 0 count. Fixes: 16c54688592c ("ext4: Allow parallel DIO reads") Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx> --- fs/ext4/inode.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 7c6e715b4d2e..3080ea82dd6d 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -3710,7 +3710,7 @@ static ssize_t ext4_direct_IO_read(struct kiocb *iocb, struct iov_iter *iter) */ inode_lock_shared(inode); ret = filemap_write_and_wait_range(mapping, iocb->ki_pos, - iocb->ki_pos + count); + iocb->ki_pos + count - 1); if (ret) goto out_unlock; ret = __blockdev_direct_IO(iocb, inode, inode->i_sb->s_bdev, -- 2.13.0.219.gdb65acc882-goog