[sheepdog] [PATCH] sheep: handle older version client correctly

[MORITA Kazutaka]

SD_PROTO_VER is a protocol version between sheep and client, so the
check of SD_PROTO_VER_TRIM_ZERO_SECTORS must be in gateway_read_obj,
not peer_read_obj.

Signed-off-by: MORITA Kazutaka <morita.kazutaka at lab.ntt.co.jp>
---
 sheep/gateway.c |   18 +++++++++++++++---
 sheep/ops.c     |    8 ++------
 2 files changed, 17 insertions(+), 9 deletions(-)

diff --git a/sheep/gateway.c b/sheep/gateway.c
index eea6d41..55b1370 100644
--- a/sheep/gateway.c
+++ b/sheep/gateway.c
@@ -39,8 +39,11 @@ int gateway_read_obj(struct request *req)
 	uint64_t oid = req->rq.obj.oid;
 	int nr_copies, j;
 
-	if (is_object_cache_enabled() && !req->local && !bypass_object_cache(req))
-		return object_cache_handle_request(req);
+	if (is_object_cache_enabled() && !req->local &&
+	    !bypass_object_cache(req)) {
+		ret = object_cache_handle_request(req);
+		goto out;
+	}
 
 	nr_copies = get_req_copy_number(req);
 	oid_to_vnodes(req->vinfo->vnodes, req->vinfo->nr_vnodes, oid,
@@ -51,7 +54,7 @@ int gateway_read_obj(struct request *req)
 			continue;
 		ret = peer_read_obj(req);
 		if (ret == SD_RES_SUCCESS)
-			return ret;
+			goto out;
 
 		eprintf("local read fail %x\n", ret);
 		break;
@@ -84,6 +87,15 @@ int gateway_read_obj(struct request *req)
 		memcpy(&req->rp, rsp, sizeof(*rsp));
 		break;
 	}
+out:
+	if (ret == SD_RES_SUCCESS &&
+	    req->rq.proto_ver < SD_PROTO_VER_TRIM_ZERO_SECTORS) {
+		/* the client doesn't support trimming zero bytes */
+		set_trimmed_sectors(req->data, req->rp.obj.offset,
+				    req->rp.data_length, req->rq.data_length);
+		req->rp.data_length = req->rq.data_length;
+		req->rp.obj.offset = 0;
+	}
 	return ret;
 }
 
diff --git a/sheep/ops.c b/sheep/ops.c
index a2a795e..df4831b 100644
--- a/sheep/ops.c
+++ b/sheep/ops.c
@@ -775,12 +775,8 @@ int peer_read_obj(struct request *req)
 		goto out;
 
 	rsp->data_length = hdr->data_length;
-
-	if (hdr->proto_ver >= SD_PROTO_VER_TRIM_ZERO_SECTORS) {
-		rsp->obj.offset = 0;
-		trim_zero_sectors(req->data, &rsp->obj.offset,
-				  &rsp->data_length);
-	}
+	rsp->obj.offset = 0;
+	trim_zero_sectors(req->data, &rsp->obj.offset, &rsp->data_length);
 
 	if (hdr->obj.copies)
 		rsp->obj.copies = hdr->obj.copies;
-- 
1.7.2.5