[sheepdog] [PATCH v5 8/8] sheep: make gateway requests only retry when requested object is local

[levin li]

From: levin li <xingke.lwp at taobao.com>

We should not make gateway retry in check_request when the
requested object in recovery is not local, in the case of requesting a
non-local object we should make it retry in io_op_done(), if the
requesting object is local, then we should make the gateway request
to retry.

Signed-off-by: levin li <xingke.lwp at taobao.com>
---
 sheep/sdnet.c |   39 ++++++++++++++++++++++++++-------------
 1 file changed, 26 insertions(+), 13 deletions(-)

diff --git a/sheep/sdnet.c b/sheep/sdnet.c
index 7cbaff8..18a1ced 100644
--- a/sheep/sdnet.c
+++ b/sheep/sdnet.c
@@ -215,22 +215,35 @@ static int check_request(struct request *req)
 	   retrying mechanism. */
 	if (is_recoverying_oid(req->local_oid) &&
 	    !(req->rq.flags & SD_FLAG_CMD_RECOVERY)) {
-		if (req->rq.flags & SD_FLAG_CMD_IO_LOCAL) {
-			/* Sheep peer request */
-			if (is_recovery_init()) {
-				req->rp.result = SD_RES_OBJ_RECOVERING;
-				list_add_tail(&req->request_list,
-						&sys->wait_rw_queue);
-			} else
-				list_add_tail(&req->request_list,
-						&sys->wait_obj_queue);
-		} else {
-			/* Gateway request */
-			list_add_tail(&req->request_list, &sys->req_wait_for_obj_list);
+		/* Only if the requested object stays in gateway, then
+		   the gateway request should be retried. */
+		if (!(req->rq.flags & SD_FLAG_CMD_IO_LOCAL)) {
+			struct sd_vnode *vnodes[SD_MAX_COPIES];
+			int i, nr_copies;
+
+			nr_copies = get_nr_copies(req->vnodes);
+			oid_to_vnodes(req->vnodes, req->local_oid,
+				      nr_copies, vnodes);
+			for (i = 0; i < nr_copies; i++) {
+				struct sd_vnode *vnode = vnodes[i];
+				if (is_myself(vnode->addr, vnode->port))
+					break;
+			}
+			if (i == nr_copies)
+				goto out;
 		}
+
+		/* Sheep peer request */
+		if (is_recovery_init()) {
+			req->rp.result = SD_RES_OBJ_RECOVERING;
+			list_add_tail(&req->request_list,
+				      &sys->wait_rw_queue);
+		} else
+			list_add_tail(&req->request_list,
+				      &sys->wait_obj_queue);
 		return -1;
 	}
-
+out:
 	if (is_access_to_busy_objects(req->local_oid)) {
 		list_add_tail(&req->request_list, &sys->req_wait_for_obj_list);
 		return -1;
-- 
1.7.10