From 79bb581eb0373c717d1ce95e817fd7411b07ff92 Mon Sep 17 00:00:00 2001
From: Johann Latocha
Date: Fri, 10 Feb 2012 23:47:32 +0100
Subject: [SERVER] Config reload fixed

---
 src/server/ipc.c    | 10 +---------
 src/server/net.c    | 45 +++++++++++++++++++++++++++++----------------
 src/server/server.c |  6 ++----
 src/server/utils.c  |  8 +++++++-
 4 files changed, 39 insertions(+), 30 deletions(-)

(limited to 'src/server')

diff --git a/src/server/ipc.c b/src/server/ipc.c
index b5651ac..4adbb7e 100644
--- a/src/server/ipc.c
+++ b/src/server/ipc.c
@@ -67,8 +67,7 @@ void* dnbd3_ipc_receive()
 
     while (1)
     {
-        int cmd;
-        int num = 0;
+        int cmd, num = 0;
         char buf[4096];
 
         // Accept connection
@@ -114,9 +113,7 @@ void* dnbd3_ipc_receive()
             break;
 
         }
-
     }
-
     close(server_sock);
 }
 
@@ -131,7 +128,6 @@ void dnbd3_ipc_send(int cmd)
         perror("ERROR: IPC socket");
         exit(EXIT_FAILURE);
     }
-
     server.sun_family = AF_UNIX;
     strcpy(server.sun_path, UNIX_SOCKET);
 
@@ -158,15 +154,12 @@ void dnbd3_ipc_send(int cmd)
     case IPC_INFO:
         send(client_sock, &cmd, sizeof(int), MSG_WAITALL);
         recv(client_sock, &num, sizeof(int), MSG_WAITALL);
-
         printf("INFO: Number clients connected: %i\n", num);
-
         for (i = 0; i < num; i++)
         {
             if (recv(client_sock, &buf, sizeof(buf), MSG_WAITALL) > 0)
                 printf("INFO: %s", buf);
         }
-
         break;
 
     default:
@@ -174,6 +167,5 @@ void dnbd3_ipc_send(int cmd)
         break;
 
     }
-
     close(client_sock);
 }
diff --git a/src/server/net.c b/src/server/net.c
index 4f2ddfa..e4be703 100644
--- a/src/server/net.c
+++ b/src/server/net.c
@@ -41,6 +41,7 @@ void *dnbd3_handle_query(void *dnbd3_client)
     dnbd3_reply_t reply;
 
     int image_file = -1;
+    dnbd3_image_t *image;
 
     struct in_addr server;
     int i = 0;
@@ -48,13 +49,24 @@ void *dnbd3_handle_query(void *dnbd3_client)
     while (recv(client->sock, &request, sizeof(dnbd3_request_t), MSG_WAITALL) > 0)
     {
         reply.cmd = request.cmd;
+        reply.error = 0;
         memcpy(reply.handle, request.handle, sizeof(request.handle));
 
         // TODO: lock CMD_GET_SERVERS and CMD_GET_SIZE because of reloading cfg...
+        // pthread_spin_lock(&_spinlock);
+        // pthread_spin_unlock(&_spinlock);
 
         switch (request.cmd)
         {
         case CMD_GET_SERVERS:
+            if(!client->image)
+            { // configuration was reloaded, send error
+                reply.size = 0;
+                reply.error = ERROR_RELOAD;
+                send(client->sock, (char *) &reply, sizeof(dnbd3_reply_t), 0);
+                continue;
+            }
+
             if (client->image->num_servers < MAX_NUMBER_SERVERS)
                 reply.size = client->image->num_servers * sizeof(struct in_addr);
             else
@@ -67,30 +79,30 @@ void *dnbd3_handle_query(void *dnbd3_client)
                 inet_aton(client->image->servers[i], &server);
                 send(client->sock, (char *) &server, sizeof(struct in_addr), 0);
             }
-            break;
+            continue;
 
         case CMD_GET_SIZE:
-            pthread_spin_lock(&_spinlock); // because of reloading config
-            dnbd3_image_t *image = dnbd3_get_image(request.vid, request.rid);
-            pthread_spin_unlock(&_spinlock);
-            if (image)
-            {
-                image_file = open(image->file, O_RDONLY);
-                reply.size = sizeof(uint64_t);
-                client->image = image;
-            }
-            else
-            {
+            image = dnbd3_get_image(request.vid, request.rid);
+
+            if(!image)
+            { // image not found, send error
                 printf("ERROR: Client requested an unknown image id.\n");
                 reply.size = 0;
+                reply.error = ERROR_SIZE;
+                send(client->sock, (char *) &reply, sizeof(dnbd3_reply_t), 0);
+                continue;
             }
+
+            image_file = open(image->file, O_RDONLY);
+            reply.size = sizeof(uint64_t);
+            client->image = image;
             send(client->sock, (char *) &reply, sizeof(dnbd3_reply_t), 0);
             send(client->sock, &image->filesize, sizeof(uint64_t), 0);
-            break;
+            continue;
 
         case CMD_GET_BLOCK:
             if (image_file < 0)
-                break;
+                continue;
 
             reply.size = request.size;
             send(client->sock, (char *) &reply, sizeof(dnbd3_reply_t), 0);
@@ -98,11 +110,12 @@ void *dnbd3_handle_query(void *dnbd3_client)
             if (sendfile(client->sock, image_file, (off_t *) &request.offset, request.size) < 0)
                 printf("ERROR: sendfile returned -1\n");
 
-            break;
+            continue;
 
         default:
             printf("ERROR: Unknown command\n");
-            break;
+            continue;
+
         }
 
     }
diff --git a/src/server/server.c b/src/server/server.c
index a767ed6..786cc40 100644
--- a/src/server/server.c
+++ b/src/server/server.c
@@ -110,10 +110,8 @@ int main(int argc, char* argv[])
             demonize = 0;
             break;
         case 'r':
-            printf("ERROR: Buggy, do not use...\n");
-            // FIXME: segfault in dnbd3_handle_query because of free(_images)
-            // printf("INFO: Reloading configuration file...\n");
-            // dnbd3_ipc_send(IPC_RELOAD);
+             printf("INFO: Reloading configuration file...\n");
+             dnbd3_ipc_send(IPC_RELOAD);
             return EXIT_SUCCESS;
         case 's':
             printf("INFO: Stopping running server...\n");
diff --git a/src/server/utils.c b/src/server/utils.c
index 3a9215e..3091b2f 100644
--- a/src/server/utils.c
+++ b/src/server/utils.c
@@ -72,8 +72,14 @@ void dnbd3_load_config(char *file)
 
 void dnbd3_reload_config(char* config_file_name)
 {
-    free(_images);
     _num_images = 0;
+    GSList *iterator = NULL;
+    for (iterator = _dnbd3_clients; iterator; iterator = iterator->next)
+    {
+        dnbd3_client_t *client = iterator->data;
+        client->image = NULL;
+    }
+    free(_images);
     dnbd3_load_config(config_file_name);
 }
 
-- 
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