From: Matthew Dillon <dillon@apollo.backplane.com>
Date: Mon, 15 Mar 2010 17:49:03 +0000 (-0700)
Subject: HAMMER VFS - Hack cursor iterator when locked cursor moved to parent
X-Git-Tag: v2.7.0~83
X-Git-Url: https://repo.or.cz/w/dragonfly.git/commitdiff_plain/ec9b6294f7ea2d9365124dd1e50ebe21c78da8b2

HAMMER VFS - Hack cursor iterator when locked cursor moved to parent

* A cursor is also moved to its parent normally when deleting the last
  element in a node and that node is then destroyed.

Reported-by: YONETANI Tomokazu <qhwt+dfly@les.ath.cx>
---

diff --git a/sys/vfs/hammer/hammer_btree.c b/sys/vfs/hammer/hammer_btree.c
index 8a6ce34e60..91cb117426 100644
--- a/sys/vfs/hammer/hammer_btree.c
+++ b/sys/vfs/hammer/hammer_btree.c
@@ -2418,8 +2418,11 @@ btree_remove(hammer_cursor_t cursor)
 
 		/*
 		 * cursor->node is invalid, cursor up to make the cursor
-		 * valid again.
+		 * valid again.  We have to flag the condition in case
+		 * another thread wiggles an insertion in during an
+		 * iteration.
 		 */
+		cursor->flags |= HAMMER_CURSOR_ITERATE_CHECK;
 		error = hammer_cursor_up(cursor);
 	}
 	return (error);