--- sys/vfs/ext2fs/ext2_htree.c.orig
+++ sys/vfs/ext2fs/ext2_htree.c
@@ -451,10 +451,11 @@ ext2_htree_writebuf(struct inode* ip, struct ext2fs_ht
 	for (i = 0; i < info->h_levels_num; i++) {
 		struct buf *bp = info->h_levels[i].h_bp;
 		ext2_dx_csum_set(ip, (struct ext2fs_direct_2 *)bp->b_data);
+		info->h_levels[i].h_bp = NULL;
 		error = bwrite(bp);
 		if (error)
 			return (error);
 	}
@@ -879,9 +880,11 @@ ext2_htree_add_entry(struct vnode *dvp, struct ext2fs
 			ext2_htree_insert_entry_to_level(&info.h_levels[0],
 			    split_hash, blknum);
 
 			/* Write new index node to disk */
 			ext2_dx_csum_set(ip,
 			    (struct ext2fs_direct_2 *)dst_bp->b_data);
 			error = bwrite(dst_bp);
+			dst_bp = NULL;		/* bwrite consumed it */
 			ip->i_flag |= IN_CHANGE | IN_UPDATE;
 			if (error)
 				goto finish;
@@ -935,6 +938,7 @@ ext2_htree_add_entry(struct vnode *dvp, struct ext2fs
 	/* Write the target directory block */
 	ext2_dirent_csum_set(ip, (struct ext2fs_direct_2 *)bp->b_data);
 	error = bwrite(bp);
+	bp = NULL;			/* bwrite consumed it */
 	ip->i_flag |= IN_CHANGE | IN_UPDATE;
 	if (error)
 		goto finish;