[sheepdog] [PATCH v3 1/2] sheep: enhance STAT_RECOVERY for prividing information of recovery state

[Hitoshi Mitake]

Current SD_OP_STAT_RECOVERY only provides an information that
indicates the node is doing recovery or not. For providing more useful
information about progress of recovery, this patch enhances this
request.

The enhanced SD_OP_STAT_RECOVERY returns the information with struct
recovery_state. The struct contains these information:
1. a flag which indicates a sheep process is in progress or not
2. state of recovery. With this information, collie can know which
   phase of progress sheep is in.
3. Number of copied object during a recovery process.
4. Number of entire objects which should be copied during a recovery
   process.

Signed-off-by: Hitoshi Mitake <mitake.hitoshi at lab.ntt.co.jp>
---
v3:
 - make struct recovery_state a general mechanism for getting recovery
   status. Ordinal "collie node recovery" uses struct recovery_state
   for detecting recovery state instead of a result of request.

v2:
 - don't use new variables for indicating the progress
 - clean coding style
 -- change names of struct recovery_info's members
 -- fill_recovery_progress() -> get_recovery_progress()

 collie/node.c            |    8 +++++---
 include/internal_proto.h |   13 +++++++++++++
 sheep/ops.c              |    4 ++--
 sheep/recovery.c         |   22 ++++++++++++++++------
 sheep/sheep_priv.h       |    1 +
 5 files changed, 37 insertions(+), 11 deletions(-)

diff --git a/collie/node.c b/collie/node.c
index 69229f4..4230af5 100644
--- a/collie/node.c
+++ b/collie/node.c
@@ -132,17 +132,19 @@ static int node_recovery(int argc, char **argv)
 	for (i = 0; i < sd_nodes_nr; i++) {
 		char host[128];
 		struct sd_req req;
-		struct sd_rsp *rsp = (struct sd_rsp *)&req;
+		struct recovery_state state;
 
+		memset(&state, 0, sizeof(state));
 		addr_to_str(host, sizeof(host), sd_nodes[i].nid.addr, 0);
 
 		sd_init_req(&req, SD_OP_STAT_RECOVERY);
+		req.data_length = sizeof(state);
 
-		ret = collie_exec_req(host, sd_nodes[i].nid.port, &req, NULL);
+		ret = collie_exec_req(host, sd_nodes[i].nid.port, &req, &state);
 		if (ret < 0)
 			return EXIT_SYSFAIL;
 
-		if (rsp->result == SD_RES_NODE_IN_RECOVERY) {
+		if (state.in_recovery) {
 			addr_to_str(host, sizeof(host),
 					sd_nodes[i].nid.addr, sd_nodes[i].nid.port);
 			printf(raw_output ? "%d %s %d %d\n" : "%4d   %-20s%5d%11d\n",
diff --git a/include/internal_proto.h b/include/internal_proto.h
index 0061007..e42cd1b 100644
--- a/include/internal_proto.h
+++ b/include/internal_proto.h
@@ -192,4 +192,17 @@ static inline __attribute__((used)) void __sd_epoch_format_build_bug_ons(void)
 	BUILD_BUG_ON(sizeof(struct sd_node) != SD_NODE_SIZE);
 }
 
+enum rw_state {
+	RW_PREPARE_LIST, /* the recovery thread is preparing object list */
+	RW_RECOVER_OBJ, /* the thread is recoering objects */
+	RW_NOTIFY_COMPLETION, /* the thread is notifying recovery completion */
+};
+
+struct recovery_state {
+	uint32_t in_recovery;
+	enum rw_state state;
+	uint32_t nr_finished;
+	uint32_t nr_total;
+};
+
 #endif /* __INTERNAL_PROTO_H__ */
diff --git a/sheep/ops.c b/sheep/ops.c
index 5d7686c..c25aead 100644
--- a/sheep/ops.c
+++ b/sheep/ops.c
@@ -390,8 +390,8 @@ static int local_stat_sheep(struct request *req)
 static int local_stat_recovery(const struct sd_req *req, struct sd_rsp *rsp,
 					void *data)
 {
-	if (node_in_recovery())
-		return SD_RES_NODE_IN_RECOVERY;
+	get_recovery_state(data);
+	rsp->data_length = sizeof(struct recovery_state);
 
 	return SD_RES_SUCCESS;
 }
diff --git a/sheep/recovery.c b/sheep/recovery.c
index ea3101a..43598a6 100644
--- a/sheep/recovery.c
+++ b/sheep/recovery.c
@@ -11,12 +11,6 @@
 
 #include "sheep_priv.h"
 
-enum rw_state {
-	RW_PREPARE_LIST, /* the recovery thread is preparing object list */
-	RW_RECOVER_OBJ, /* the thread is recoering objects */
-	RW_NOTIFY_COMPLETION, /* the thread is notifying recovery completion */
-};
-
 /* base structure for the recovery thread */
 struct recovery_work {
 	uint32_t epoch;
@@ -882,3 +876,19 @@ static void queue_recovery_work(struct recovery_info *rinfo)
 
 	queue_work(sys->recovery_wqueue, &rw->work);
 }
+
+void get_recovery_state(struct recovery_state *state)
+{
+	struct recovery_info *rinfo = main_thread_get(current_rinfo);
+
+	if (!rinfo) {
+		state->in_recovery = false;
+		return;
+	}
+
+	state->in_recovery = true;
+	state->state = rinfo->state;
+	state->nr_finished = rinfo->done;
+	state->nr_total = rinfo->count;
+}
+
diff --git a/sheep/sheep_priv.h b/sheep/sheep_priv.h
index 09303ff..bcff3d7 100644
--- a/sheep/sheep_priv.h
+++ b/sheep/sheep_priv.h
@@ -320,6 +320,7 @@ int objlist_cache_cleanup(uint32_t vid);
 int start_recovery(struct vnode_info *cur_vinfo, struct vnode_info *, bool);
 bool oid_in_recovery(uint64_t oid);
 bool node_in_recovery(void);
+void get_recovery_state(struct recovery_state *state);
 
 int read_backend_object(uint64_t oid, char *data, unsigned int datalen,
 		       uint64_t offset);
-- 
1.7.10.4