ext4: wait for outstanding dio during truncate in nojournal mode

commit 82a25b02 upstream.

We didn't wait for outstanding direct IO during truncate in nojournal
mode (as we skip orphan handling in that case). This can lead to fs
corruption or stale data exposure if truncate ends up freeing blocks
and these get reallocated before direct IO finishes. Fix the condition
determining whether the wait is necessary.

CC: stable@vger.kernel.org
Fixes: 1c9114f9 ("ext4: serialize unlocked dio reads with truncate")
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fs/ext4/inode.c

@@ -5624,20 +5624,17 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr)
 				goto err_out;
 			}
 		}
-		if (!shrink)
+		if (!shrink) {
 			pagecache_isize_extended(inode, oldsize, inode->i_size);
-
+		} else {
 			/*
 			 * Blocks are going to be removed from the inode. Wait
-		 * for dio in flight.  Temporarily disable
-		 * dioread_nolock to prevent livelock.
+			 * for dio in flight.
 			 */
-		if (orphan) {
-			if (!ext4_should_journal_data(inode)) {
 			inode_dio_wait(inode);
-			} else
-				ext4_wait_for_tail_page_commit(inode);
 		}
+		if (orphan && ext4_should_journal_data(inode))
+			ext4_wait_for_tail_page_commit(inode);
 		down_write(&EXT4_I(inode)->i_mmap_sem);
 
 		rc = ext4_break_layouts(inode);