ocfs2: Added post handler callable function in o2net message handler

Currently o2net allows one handler function per message type. This
patch adds the ability to call another function to be called after
the handler has returned the message to the other node.

Handlers are now given the option of returning a context (in the form of a
void **) which will be passed back into the post message handler function.

Signed-off-by: Kurt Hackel <kurt.hackel@oracle.com>
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

3 files changed, 18 insertions, 2 deletions

diff --git a/fs/ocfs2/cluster/tcp.c b/fs/ocfs2/cluster/tcp.c
index ae4ff4a6636b..7700418d25ec 100644
--- a/fs/ocfs2/cluster/tcp.c
+++ b/fs/ocfs2/cluster/tcp.c
@@ -688,6 +688,7 @@ static void o2net_handler_put(struct o2net_msg_handler *nmh)
  * be given to the handler if their payload is longer than the max. */
 int o2net_register_handler(u32 msg_type, u32 key, u32 max_len,
                            o2net_msg_handler_func *func, void *data,
+                           o2net_post_msg_handler_func *post_func,
                            struct list_head *unreg_list)
 {
         struct o2net_msg_handler *nmh = NULL;
@@ -722,6 +723,7 @@ int o2net_register_handler(u32 msg_type, u32 key, u32 max_len,
 
         nmh->nh_func = func;
         nmh->nh_func_data = data;
+        nmh->nh_post_func = post_func;
         nmh->nh_msg_type = msg_type;
         nmh->nh_max_len = max_len;
         nmh->nh_key = key;
@@ -1049,6 +1051,7 @@ static int o2net_process_message(struct o2net_sock_container *sc,
         int ret = 0, handler_status;
         enum  o2net_system_error syserr;
         struct o2net_msg_handler *nmh = NULL;
+        void *ret_data = NULL;
 
         msglog(hdr, "processing message\n");
 
@@ -1101,7 +1104,7 @@ static int o2net_process_message(struct o2net_sock_container *sc,
         sc->sc_msg_type = be16_to_cpu(hdr->msg_type);
         handler_status = (nmh->nh_func)(hdr, sizeof(struct o2net_msg) +
                                              be16_to_cpu(hdr->data_len),
-                                        nmh->nh_func_data);
+                                        nmh->nh_func_data, &ret_data);
         do_gettimeofday(&sc->sc_tv_func_stop);
 
 out_respond:
@@ -1112,6 +1115,13 @@ out_respond:
         mlog(0, "sending handler status %d, syserr %d returned %d\n",
              handler_status, syserr, ret);
 
+        if (nmh) {
+                BUG_ON(ret_data != NULL && nmh->nh_post_func == NULL);
+                if (nmh->nh_post_func)
+                        (nmh->nh_post_func)(handler_status, nmh->nh_func_data,
+                                            ret_data);
+        }
+
 out:
         if (nmh)
                 o2net_handler_put(nmh);
diff --git a/fs/ocfs2/cluster/tcp.h b/fs/ocfs2/cluster/tcp.h
index 21a4e43df836..da880fc215f0 100644
--- a/fs/ocfs2/cluster/tcp.h
+++ b/fs/ocfs2/cluster/tcp.h
@@ -50,7 +50,10 @@ struct o2net_msg
         __u8  buf[0];
 };
 
-typedef int (o2net_msg_handler_func)(struct o2net_msg *msg, u32 len, void *data);
+typedef int (o2net_msg_handler_func)(struct o2net_msg *msg, u32 len, void *data,
+                                     void **ret_data);
+typedef void (o2net_post_msg_handler_func)(int status, void *data,
+                                           void *ret_data);
 
 #define O2NET_MAX_PAYLOAD_BYTES  (4096 - sizeof(struct o2net_msg))
 
@@ -99,6 +102,7 @@ int o2net_send_message_vec(u32 msg_type, u32 key, struct kvec *vec,
 
 int o2net_register_handler(u32 msg_type, u32 key, u32 max_len,
                            o2net_msg_handler_func *func, void *data,
+                           o2net_post_msg_handler_func *post_func,
                            struct list_head *unreg_list);
 void o2net_unregister_handler_list(struct list_head *list);
 
diff --git a/fs/ocfs2/cluster/tcp_internal.h b/fs/ocfs2/cluster/tcp_internal.h
index 775c911342f4..d74040fac343 100644
--- a/fs/ocfs2/cluster/tcp_internal.h
+++ b/fs/ocfs2/cluster/tcp_internal.h
@@ -161,6 +161,8 @@ struct o2net_msg_handler {
         u32                     nh_key;
         o2net_msg_handler_func  *nh_func;
         o2net_msg_handler_func  *nh_func_data;
+        o2net_post_msg_handler_func
+                                *nh_post_func;
         struct kref             nh_kref;
         struct list_head        nh_unregister_item;
 };