diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
index 3e57a56cf829..2693ba84ec25 100644
--- a/fs/xfs/xfs_aops.c
+++ b/fs/xfs/xfs_aops.c
@@ -1361,6 +1361,26 @@ __xfs_get_blocks(
 	if (error)
 		goto out_unlock;
 
+	/*
+	 * The only time we can ever safely find delalloc blocks on direct I/O
+	 * is a dio write to post-eof speculative preallocation. All other
+	 * scenarios are indicative of a problem or misuse (such as mixing
+	 * direct and mapped I/O).
+	 *
+	 * The file may be unmapped by the time we get here so we cannot
+	 * reliably fail the I/O based on mapping. Instead, fail the I/O if this
+	 * is a read or a write within eof. Otherwise, carry on but warn as a
+	 * precuation if the file happens to be mapped.
+	 */
+	if (direct && imap.br_startblock == DELAYSTARTBLOCK) {
+		if (!create || offset < i_size_read(VFS_I(ip))) {
+			WARN_ON_ONCE(1);
+			error = -EIO;
+			goto out_unlock;
+		}
+		WARN_ON_ONCE(mapping_mapped(VFS_I(ip)->i_mapping));
+	}
+
 	/* for DAX, we convert unwritten extents directly */
 	if (create &&
 	    (!nimaps ||
@@ -1450,8 +1470,6 @@ __xfs_get_blocks(
 	     (new || ISUNWRITTEN(&imap))))
 		set_buffer_new(bh_result);
 
-	BUG_ON(direct && imap.br_startblock == DELAYSTARTBLOCK);
-
 	return 0;
 
 out_unlock: