cluster: STABLE3 - qdiskd: Autoconfigure votes based on node count

[Lon Hohberger]

Gitweb:       
http://git.fedorahosted.org/git/cluster.git?p=cluster.git;a=commitdiff;h=...
Commit:        77279c9976e222473c041f3896046f1134ee34fe
Parent:        704fd5bb382ff452fc8403b9a2322e73b918619d
Author:        Lon Hohberger <lhh(a)redhat.com&gt;
AuthorDate:    Fri Feb 19 12:18:58 2010 -0500
Committer:     Lon Hohberger <lhh(a)redhat.com&gt;
CommitterDate: Fri Feb 19 12:18:58 2010 -0500

qdiskd: Autoconfigure votes based on node count

This makes qdiskd easier to use for most configurations
and does not override existing configurations.

Signed-off-by: Lon Hohberger <lhh(a)redhat.com&gt;
---
 cman/man/qdisk.5  |    5 +++--
 cman/qdisk/main.c |   36 ++++++++++++++++++++++++++++++++++++
 2 files changed, 39 insertions(+), 2 deletions(-)

diff --git a/cman/man/qdisk.5 b/cman/man/qdisk.5
index 1a74470..abd80dc 100644
--- a/cman/man/qdisk.5
+++ b/cman/man/qdisk.5
@@ -73,7 +73,7 @@ the amount of synchronous I/O contention on the shared quorum disk.
 * Cluster node IDs must be statically configured in cluster.conf and
 must be numbered from 1..16 (there can be gaps, of course).
 
-* Cluster node votes should be more or less equal.
+* Cluster node votes should all be 1.
 
 * CMAN must be running before the qdisk program can operate in full
 capacity.  If CMAN is not running, qdisk will wait for it.
@@ -239,7 +239,8 @@ exceed \fBtko\fP.
 \fIvotes\fP\fB="\fP3\fB"\fP
 .in 12
 This is the number of votes the quorum daemon advertises to CMAN when it
-has a high enough score.
+has a high enough score.  The default is the number of nodes in the cluster
+minus 1.  For example, in a 4 node cluster, the default is 3.
 
 .in 9
 \fIlog_level\fP\fB="\fP4\fB"\fP
diff --git a/cman/qdisk/main.c b/cman/qdisk/main.c
index 85a0563..5d984dc 100644
--- a/cman/qdisk/main.c
+++ b/cman/qdisk/main.c
@@ -1469,6 +1469,40 @@ get_dynamic_config_data(qd_ctx *ctx, int ccsfd)
 
 
 static int
+auto_qdisk_votes(int desc)
+{
+	int x, ret = 0;
+	char buf[128];
+	char *name;
+
+	if (desc < 0) {
+		return 1;
+	}
+
+	while (++x) {
+		snprintf(buf, sizeof(buf)-1,
+			"/cluster/clusternodes/clusternode[%d]/@name", x);
+
+		name = NULL;
+		if (ccs_get(desc, buf, &name) != 0)
+			break;
+
+		free(name);
+		ret = x;
+	}
+
+	--ret;
+	if (ret <= 0) {
+		ret = 1;
+	}
+
+	logt_print(LOG_DEBUG, "Setting votes to %d\n", ret);
+
+	return (ret);
+}
+
+
+static int
 get_static_config_data(qd_ctx *ctx, int ccsfd) 
 {
 	char *val = NULL;
@@ -1574,6 +1608,8 @@ get_static_config_data(qd_ctx *ctx, int ccsfd)
 		free(val);
 		if (ctx->qc_votes < 0)
 			ctx->qc_votes = 0;
+	} else {
+		ctx->qc_votes = auto_qdisk_votes(ccsfd);
 	}
 
 	/* Get device */