[sheepdog] [PATCH 4/9] sheep: associate client info and locked vdi

[Hitoshi Mitake]

This patch associates client info and locked vdi. The association is
required for releasing locked VDI in a case of unexpected death of
clients.

Signed-off-by: Hitoshi Mitake <mitake.hitoshi at lab.ntt.co.jp>
---
 sheep/ops.c        |   49 ++++++++++++++++++++++++++++++++++++++++++++++++-
 sheep/request.c    |   12 ++++++++++++
 sheep/sheep_priv.h |    4 ++++
 3 files changed, 64 insertions(+), 1 deletions(-)

diff --git a/sheep/ops.c b/sheep/ops.c
index 1056935..26335cc 100644
--- a/sheep/ops.c
+++ b/sheep/ops.c
@@ -235,6 +235,18 @@ static int cluster_get_vdi_info(struct request *req)
 	return ret;
 }
 
+static int cluster_lock_vdi_work(struct request *req)
+{
+	int ret;
+
+	ret = cluster_get_vdi_info(req);
+	if (ret != SD_RES_SUCCESS)
+		return ret;
+
+	req->ci->interest_vid = req->rp.vdi.vdi_id;
+	return ret;
+}
+
 static int remove_epoch(uint32_t epoch)
 {
 	int ret;
@@ -1254,6 +1266,41 @@ static int cluster_lock_vdi(const struct sd_req *req, struct sd_rsp *rsp,
 		return SD_RES_VDI_NOT_LOCKED;
 	}
 
+	if (!memcmp(&sender->nid, &sys->this_node.nid,
+		    sizeof(struct node_id))) {
+		struct client_info *ci = lookup_interested_client(vid);
+		ci->locking_interest_vid = true;
+
+		sd_debug("client with fd: %d is interested in VDI: %"PRIx32,
+			 ci->conn.fd, vid);
+	}
+
+	return SD_RES_SUCCESS;
+}
+
+static int cluster_release_vdi_main(const struct sd_req *req,
+				    struct sd_rsp *rsp, void *data,
+				    const struct sd_node *sender)
+{
+	uint32_t vid = req->vdi.base_vdi_id;
+
+	sd_info("node: %s is unlocking VDI: %"PRIx32, node_to_str(sender), vid);
+
+	unlock_vdi(vid, &sender->nid);
+
+	if (node_is_local(sender)) {
+		struct client_info *ci = lookup_interested_client(vid);
+
+		if (!ci)	/* client is already destroyed */
+			return SD_RES_SUCCESS;
+
+		ci->locking_interest_vid = false;
+		ci->interest_vid = 0;
+
+		sd_debug("client with fd: %d is unlocking VDI: %"PRIx32,
+			 ci->conn.fd, vid);
+	}
+
 	return SD_RES_SUCCESS;
 }
 
@@ -1350,7 +1397,7 @@ static struct sd_op_template sd_ops[] = {
 	[SD_OP_LOCK_VDI] = {
 		.name = "LOCK_VDI",
 		.type = SD_OP_TYPE_CLUSTER,
-		.process_work = cluster_get_vdi_info,
+		.process_work = cluster_lock_vdi_work,
 		.process_main = cluster_lock_vdi,
 	},
 
diff --git a/sheep/request.c b/sheep/request.c
index 6a6b61f..96500b9 100644
--- a/sheep/request.c
+++ b/sheep/request.c
@@ -913,6 +913,18 @@ static void clear_client_info(struct client_info *ci)
 
 static LIST_HEAD(client_list);
 
+struct client_info *lookup_interested_client(uint32_t vid)
+{
+	struct client_info *ci;
+
+	list_for_each_entry(ci, &client_list, list) {
+		if (ci->interest_vid == vid)
+			return ci;
+	}
+
+	return NULL;
+}
+
 static struct client_info *create_client(int fd, struct cluster_info *cluster)
 {
 	struct client_info *ci;
diff --git a/sheep/sheep_priv.h b/sheep/sheep_priv.h
index fdf07e0..f2d03b4 100644
--- a/sheep/sheep_priv.h
+++ b/sheep/sheep_priv.h
@@ -77,6 +77,9 @@ struct client_info {
 	refcnt_t refcnt;
 
 	struct list_node list;
+
+	bool locking_interest_vid;
+	uint32_t interest_vid;
 };
 
 enum REQUST_STATUS {
@@ -322,6 +325,7 @@ static inline bool is_aligned_to_pagesize(void *p)
 int create_listen_port(const char *bindaddr, int port);
 int init_unix_domain_socket(const char *dir);
 void unregister_listening_fds(void);
+struct client_info *lookup_interested_client(uint32_t vid);
 
 int init_store_driver(bool is_gateway);
 int init_global_pathnames(const char *d, char *);
-- 
1.7.1