[sheepdog] [PATCH v2 03/10] sheep: recover from local if possible

[MORITA Kazutaka]

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

Signed-off-by: MORITA Kazutaka <morita.kazutaka at lab.ntt.co.jp>
---
 sheep/recovery.c |   27 +++++++++++++++++++--------
 1 file changed, 19 insertions(+), 8 deletions(-)

diff --git a/sheep/recovery.c b/sheep/recovery.c
index bf54b63..46c167c 100644
--- a/sheep/recovery.c
+++ b/sheep/recovery.c
@@ -91,6 +91,23 @@ static int recover_object_from_replica(uint64_t oid, struct vnode_info *old,
 	void *buf = NULL;
 	struct siocb iocb = { 0 };
 
+	nr_copies = get_obj_copy_number(oid, old->nr_zones);
+
+	/* find local node first to try to recover from local */
+	for (int i = 0; i < nr_copies; i++) {
+		const struct sd_vnode *vnode;
+
+		vnode = oid_to_vnode(old->vnodes, old->nr_vnodes, oid, i);
+
+		if (vnode_is_local(vnode)) {
+			if (tgt_epoch < sys_epoch())
+				ret = sd_store->link(oid, tgt_epoch);
+			else
+				ret = SD_RES_NO_OBJ;
+			goto out;
+		}
+	}
+
 	rlen = get_objsize(oid);
 	buf = valloc(rlen);
 	if (!buf) {
@@ -100,7 +117,6 @@ static int recover_object_from_replica(uint64_t oid, struct vnode_info *old,
 	}
 
 	/* Let's do a breadth-first search */
-	nr_copies = get_obj_copy_number(oid, old->nr_zones);
 	for (int i = 0; i < nr_copies; i++) {
 		const struct sd_vnode *vnode;
 
@@ -109,13 +125,8 @@ static int recover_object_from_replica(uint64_t oid, struct vnode_info *old,
 		if (is_invalid_vnode(vnode, cur->nodes, cur->nr_nodes))
 			continue;
 
-		if (vnode_is_local(vnode)) {
-			if (tgt_epoch < sys_epoch())
-				ret = sd_store->link(oid, tgt_epoch);
-			else
-				ret = SD_RES_NO_OBJ;
-			goto out;
-		}
+		if (vnode_is_local(vnode))
+			continue;
 
 		sd_init_req(&hdr, SD_OP_READ_PEER);
 		hdr.epoch = epoch;
-- 
1.7.9.5