xfs: connect up write verifiers to new buffers

Metadata buffers that are read from disk have write verifiers
already attached to them, but newly allocated buffers do not. Add
appropriate write verifiers to all new metadata buffers.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

fs/xfs/xfs_inode.c

@@ -420,7 +420,7 @@ xfs_inode_buf_verify(
 	xfs_inobp_check(mp, bp);
 }
 
-static void
+void
 xfs_inode_buf_write_verify(
 	struct xfs_buf	*bp)
 {
@@ -1782,6 +1782,18 @@ xfs_ifree_cluster(
 
 		if (!bp)
 			return ENOMEM;
+
+		/*
+		 * This buffer may not have been correctly initialised as we
+		 * didn't read it from disk. That's not important because we are
+		 * only using to mark the buffer as stale in the log, and to
+		 * attach stale cached inodes on it. That means it will never be
+		 * dispatched for IO. If it is, we want to know about it, and we
+		 * want it to fail. We can acheive this by adding a write
+		 * verifier to the buffer.
+		 */
+		 bp->b_pre_io = xfs_inode_buf_write_verify;
+
 		/*
 		 * Walk the inodes already attached to the buffer and mark them
 		 * stale. These will all have the flush locks held, so an