[Ocfs2-tools-devel] [PATCH] ocfs2_controld: Handle simultaneous group join.

[Joel Becker]

[ I've had this in my tree for a while.  I meant to send it to Lars to
  test as well. ]

More than one ocfs2_controld can join the cpg group at the same time,
even for the first members of a group.  So 'joiners == 1' is not a valid
check to see if this controld is the first one.

We change the code to pick the controld with the lowest node number to
set up the daemon control group.

Signed-off-by: Joel Becker <joel.becker at oracle.com>
---
 ocfs2_controld/cpg.c |   13 ++++++++++++-
 1 files changed, 12 insertions(+), 1 deletions(-)

diff --git a/ocfs2_controld/cpg.c b/ocfs2_controld/cpg.c
index a2d8ae1..5e166b0 100644
--- a/ocfs2_controld/cpg.c
+++ b/ocfs2_controld/cpg.c
@@ -728,6 +728,8 @@ out:
 
 static void daemon_set_cgroup(struct cgroup *cg, void *user_data)
 {
+	int i, first = 1;
+
 	void (*daemon_joined)(int first) = user_data;
 
 	if (cg != &daemon_group) {
@@ -735,7 +737,16 @@ static void daemon_set_cgroup(struct cgroup *cg, void *user_data)
 		return;
 	}
 
-	daemon_joined(daemon_group.cg_member_count == 1);
+	if (daemon_group.cg_cb_member_count != daemon_group.cg_cb_joined_count)
+		first = 0;
+	else {
+		for (i = 0; i < daemon_group.cg_cb_joined_count; i++) {
+			if (daemon_group.cg_cb_joined[i].nodeid < our_nodeid)
+				first = 0;
+		}
+	}
+
+	daemon_joined(first);
 }
 
 int setup_cpg(void (*daemon_joined)(int first))
-- 
1.6.3.1


-- 

"The doctrine of human equality reposes on this: that there is no
 man really clever who has not found that he is stupid."
	- Gilbert K. Chesterson

Joel Becker
Principal Software Developer
Oracle
E-mail: joel.becker at oracle.com
Phone: (650) 506-8127