[sheepdog] [PATCH 3/3] sheep: get vdi bitmap from joined node

[MORITA Kazutaka]

From: MORITA Kazutaka <morita.kazutaka at lab.ntt.co.jp>

If we stop sheepdog without the shutdown command, the number of nodes
will be rapidly reduced and it will easily happen that all the
replicas are lost.  In such case, it is better to get vdi bitmap from
the newly joined node too so that we can recover so many vdis as we
can.

Signed-off-by: MORITA Kazutaka <morita.kazutaka at lab.ntt.co.jp>
---
 sheep/group.c |   17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/sheep/group.c b/sheep/group.c
index a8e5433..f076f63 100644
--- a/sheep/group.c
+++ b/sheep/group.c
@@ -37,6 +37,7 @@ struct node {
 struct get_vdis_work {
 	struct work work;
 	DECLARE_BITMAP(vdi_inuse, SD_NR_VDIS);
+	struct sd_node joined;
 	size_t nr_members;
 	struct sd_node members[];
 };
@@ -687,6 +688,15 @@ static void do_get_vdis(struct work *work)
 		container_of(work, struct get_vdis_work, work);
 	int i, ret;
 
+	if (!node_eq(&w->joined, &sys->this_node)) {
+		switch (sys->status) {
+		case SD_STATUS_OK:
+		case SD_STATUS_HALT:
+			get_vdis_from(&w->joined);
+			return;
+		}
+	}
+
 	for (i = 0; i < w->nr_members; i++) {
 		/* We should not fetch vdi_bitmap and copy list from myself */
 		if (node_eq(&w->members[i], &sys->this_node))
@@ -803,12 +813,14 @@ static void finish_join(const struct join_message *msg,
 	sockfd_cache_add_group(nodes, nr_nodes);
 }
 
-static void get_vdis(const struct sd_node *nodes, size_t nr_nodes)
+static void get_vdis(const struct sd_node *nodes, size_t nr_nodes,
+		     const struct sd_node *joined)
 {
 	int array_len = nr_nodes * sizeof(struct sd_node);
 	struct get_vdis_work *w;
 
 	w = xmalloc(sizeof(*w) + array_len);
+	w->joined = *joined;
 	w->nr_members = nr_nodes;
 	memcpy(w->members, nodes, array_len);
 
@@ -889,12 +901,13 @@ static void update_cluster_info(const struct join_message *msg,
 			/*FALLTHROUGH*/
 		case SD_STATUS_WAIT_FOR_JOIN:
 			sys->disable_recovery = msg->disable_recovery;
-			get_vdis(nodes, nr_nodes);
 			break;
 		default:
 			break;
 		}
 
+		get_vdis(nodes, nr_nodes, joined);
+
 		sys->status = msg->cluster_status;
 
 		if (msg->inc_epoch) {
-- 
1.7.9.5