ext4: Remove wait for unwritten extents in ext4_ind_direct_IO()

We don't have to wait for unwritten extent conversion in
ext4_ind_direct_IO() as all writes that happened before DIO are
flushed by the generic code and extent conversion has happened before
we cleared PageWriteback bit.
Reviewed-by: NZheng Liu <wenqing.lz@taobao.com>
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

fs/ext4/indirect.c

@@ -675,11 +675,6 @@ ssize_t ext4_ind_direct_IO(int rw, struct kiocb *iocb,
 
 retry:
 	if (rw == READ && ext4_should_dioread_nolock(inode)) {
-		if (unlikely(atomic_read(&EXT4_I(inode)->i_unwritten))) {
-			mutex_lock(&inode->i_mutex);
-			ext4_flush_unwritten_io(inode);
-			mutex_unlock(&inode->i_mutex);
-		}
 		/*
 		 * Nolock dioread optimization may be dynamically disabled
 		 * via ext4_inode_block_unlocked_dio(). Check inode's state