ext4: wait for outstanding dio during truncate in nojournal mode

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: [email protected]
Fixes: 1c9114f ("ext4: serialize unlocked dio reads with truncate")
Reviewed-by: Ira Weiny <[email protected]>
Signed-off-by: Jan Kara <[email protected]>
Signed-off-by: Theodore Ts'o <[email protected]>

Author: jankara

fs/ext4/inode.c

@@ -5630,20 +5630,17 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr)
 				goto err_out;
 			}
 		}
-		if (!shrink)
+		if (!shrink) {
 			pagecache_isize_extended(inode, oldsize, inode->i_size);
-
-		/*
-		 * Blocks are going to be removed from the inode. Wait
-		 * for dio in flight.  Temporarily disable
-		 * dioread_nolock to prevent livelock.
-		 */
-		if (orphan) {
-			if (!ext4_should_journal_data(inode)) {
-				inode_dio_wait(inode);
-			} else
-				ext4_wait_for_tail_page_commit(inode);
+		} else {
+			/*
+			 * Blocks are going to be removed from the inode. Wait
+			 * for dio in flight.
+			 */
+			inode_dio_wait(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);