ext4: Use direct_IO_no_locking in ext4 dio read

Signed-off-by: Jiaying Zhang <jiayingz@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

fs/ext4/inode.c

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index d291310..92214d4 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3474,7 +3474,14 @@
 	}
 
 retry:
-	ret = blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
+	if (rw == READ && ext4_should_dioread_nolock(inode))
+		ret = blockdev_direct_IO_no_locking(rw, iocb, inode,
+				 inode->i_sb->s_bdev, iov,
+				 offset, nr_segs,
+				 ext4_get_block, NULL);
+	else
+		ret = blockdev_direct_IO(rw, iocb, inode,
+				 inode->i_sb->s_bdev, iov,
 				 offset, nr_segs,
 				 ext4_get_block, NULL);
 	if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))