From: Niu Yawei <yawei.niu@intel.com>
Date: Wed, 5 Mar 2014 12:17:39 +0000 (-0500)
Subject: LU-4702 nodemap: fix nm_rbtree_postorder_for_each_entry_safe()
X-Git-Tag: 2.5.57~23
X-Git-Url: https://git.whamcloud.com/?p=fs%2Flustre-release.git;a=commitdiff_plain;h=155031eeacbb4b79fec7cc2a811afcba9fb39d7a

LU-4702 nodemap: fix nm_rbtree_postorder_for_each_entry_safe()

It should check if the 'pos' && 'n' is NULL.

Signed-off-by: Niu Yawei <yawei.niu@intel.com>
Change-Id: Ibda34ec4cf1706f0651ed8c86a2e49e4a36cd2c0
Reviewed-on: http://review.whamcloud.com/9500
Tested-by: Jenkins
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Joshua Walgenbach <jjw@iu.edu>
---

diff --git a/lustre/nodemap/nodemap_internal.h b/lustre/nodemap/nodemap_internal.h
index af3836e..7751177 100644
--- a/lustre/nodemap/nodemap_internal.h
+++ b/lustre/nodemap/nodemap_internal.h
@@ -96,12 +96,15 @@ struct rb_node *nm_rb_first_postorder(const struct rb_root *root);
 
 #define nm_rbtree_postorder_for_each_entry_safe(pos, n,			\
 						root, field)		\
-	for (pos = rb_entry(nm_rb_first_postorder(root), typeof(*pos),	\
-			    field),					\
-		n = rb_entry(nm_rb_next_postorder(&pos->field),		\
-		typeof(*pos), field);					\
-		&pos->field;						\
+	for (pos = nm_rb_first_postorder(root) ?			\
+		rb_entry(nm_rb_first_postorder(root), typeof(*pos),	\
+		field) : NULL,						\
+		n = (pos && nm_rb_next_postorder(&pos->field)) ?	\
+		rb_entry(nm_rb_next_postorder(&pos->field),		\
+		typeof(*pos), field) : NULL;				\
+		pos != NULL;						\
 		pos = n,						\
-		n = rb_entry(nm_rb_next_postorder(&pos->field),		\
-			     typeof(*pos), field))
+		n = (pos && nm_rb_next_postorder(&pos->field)) ?	\
+		rb_entry(nm_rb_next_postorder(&pos->field),		\
+		typeof(*pos), field) : NULL)
 #endif  /* _NODEMAP_INTERNAL_H */