[SERVER] Config reload fixed

10 files changed, 169 insertions, 135 deletions

diff --git a/src/kernel/blk.c b/src/kernel/blk.c
index 8a76b0d..4d5b4b5 100644
--- a/src/kernel/blk.c
+++ b/src/kernel/blk.c
@@ -34,6 +34,7 @@ int dnbd3_blk_add_device(dnbd3_device_t *dev, int minor)
     dev->vid = 0;
     dev->rid = 0;
     dev->sock = NULL;
+    dev->num_servers = 0;
     dev->thread_send = NULL;
     dev->thread_receive = NULL;
 
@@ -63,8 +64,6 @@ int dnbd3_blk_add_device(dnbd3_device_t *dev, int minor)
     queue_flag_set_unlocked(QUEUE_FLAG_NONROT, disk->queue);
     dev->disk = disk;
 
-    dev->hb_request.cmd_type = REQ_TYPE_SPECIAL;
-
     add_disk(disk); // must be last
     return 0;
 }
@@ -123,7 +122,9 @@ int dnbd3_blk_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd, u
         break;
 
     default:
+        kfree(msg);
         return -1;
+
     }
 
     kfree(msg);
diff --git a/src/kernel/blk.h b/src/kernel/blk.h
index bf5ad80..57d9bfa 100644
--- a/src/kernel/blk.h
+++ b/src/kernel/blk.h
@@ -23,6 +23,12 @@
 
 #include "dnbd3.h"
 
+enum
+{
+    REQ_GET_SERVERS = 1,
+    REQ_GET_FILESIZE = 2,
+};
+
 extern struct block_device_operations dnbd3_blk_ops;
 
 int dnbd3_blk_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd, unsigned long arg);
diff --git a/src/kernel/dnbd3.h b/src/kernel/dnbd3.h
index c260e18..b21dba3 100644
--- a/src/kernel/dnbd3.h
+++ b/src/kernel/dnbd3.h
@@ -44,12 +44,9 @@ typedef struct
     int rid;
     struct socket *sock;
     struct timer_list hb_timer;
-    struct request hb_request;
-
     int num_servers;
     struct in_addr servers[MAX_NUMBER_SERVERS];
 
-
     // process
     struct task_struct *thread_send;
     struct task_struct *thread_receive;
diff --git a/src/kernel/net.c b/src/kernel/net.c
index 7afac7d..5bd8871 100644
--- a/src/kernel/net.c
+++ b/src/kernel/net.c
@@ -19,23 +19,25 @@
  */
 
 #include "net.h"
+#include "blk.h"
 #include "utils.h"
 
 void dnbd3_net_connect(dnbd3_device_t *dev)
 {
     struct sockaddr_in sin;
-    struct msghdr msg;
-    struct kvec iov;
-    dnbd3_request_t dnbd3_request;
-    dnbd3_reply_t dnbd3_reply;
-    uint64_t filesize;
+    struct request *req = kmalloc(sizeof(struct request), GFP_ATOMIC);
 
+    // do some checks before connecting
+    if (!req)
+    {
+        printk("ERROR: Kmalloc failed.\n");
+        return;
+    }
     if (!dev->host || !dev->port || (dev->vid == 0))
     {
         printk("ERROR: Host, port or vid not set.\n");
         return;
     }
-
     if (dev->sock)
     {
         printk("ERROR: Device %s already connected to %s.\n", dev->disk->disk_name, dev->host);
@@ -62,40 +64,6 @@ void dnbd3_net_connect(dnbd3_device_t *dev)
         return;
     }
 
-    // prepare message
-    dnbd3_request.cmd = CMD_GET_SIZE;
-    dnbd3_request.vid = dev->vid;
-    dnbd3_request.rid = dev->rid;
-    msg.msg_name = NULL;
-    msg.msg_namelen = 0;
-    msg.msg_control = NULL;
-    msg.msg_controllen = 0;
-    msg.msg_flags = MSG_WAITALL | MSG_NOSIGNAL; // No SIGPIPE
-
-    // send message
-    iov.iov_base = &dnbd3_request;
-    iov.iov_len = sizeof(dnbd3_request);
-    kernel_sendmsg(dev->sock, &msg, &iov, 1, sizeof(dnbd3_request));
-
-    // receive replay
-    iov.iov_base = &dnbd3_reply;
-    iov.iov_len = sizeof(dnbd3_reply);
-    kernel_recvmsg(dev->sock, &msg, &iov, 1, sizeof(dnbd3_reply), msg.msg_flags);
-    if (dnbd3_reply.size <= 0)
-    {
-        printk("ERROR: File size returned by server is < 0.\n");
-        sock_release(dev->sock);
-        dev->sock = NULL;
-        return;
-    }
-
-    // receive and set filesize
-    iov.iov_base = &filesize;
-    iov.iov_len = sizeof(uint64_t);
-    kernel_recvmsg(dev->sock, &msg, &iov, 1, dnbd3_reply.size, msg.msg_flags);
-    set_capacity(dev->disk, filesize >> 9); /* 512 Byte blocks */
-    printk("INFO: Filesize %s: %llu\n", dev->disk->disk_name, filesize);
-
     // start sending thread
     dev->thread_send = kthread_create(dnbd3_net_send, dev, dev->disk->disk_name);
     wake_up_process(dev->thread_send);
@@ -104,12 +72,18 @@ void dnbd3_net_connect(dnbd3_device_t *dev)
     dev->thread_receive = kthread_create(dnbd3_net_receive, dev, dev->disk->disk_name);
     wake_up_process(dev->thread_receive);
 
-    // Add heartbeat timer
+    // add heartbeat timer
     init_timer(&dev->hb_timer);
     dev->hb_timer.data = (unsigned long) dev;
     dev->hb_timer.function = dnbd3_net_heartbeat;
     dev->hb_timer.expires = jiffies + HB_INTERVAL;
     add_timer(&dev->hb_timer);
+
+    // enqueue request to request_queue_send (ask file size)
+    req->cmd_type = REQ_TYPE_SPECIAL;
+    req->cmd_flags = REQ_GET_FILESIZE;
+    list_add(&req->queuelist, &dev->request_queue_send);
+    wake_up(&dev->process_queue_send);
 }
 
 void dnbd3_net_disconnect(dnbd3_device_t *dev)
@@ -124,7 +98,7 @@ void dnbd3_net_disconnect(dnbd3_device_t *dev)
         kthread_stop(dev->thread_receive);
     }
 
-    // clear sock
+    // clear socket
     if (dev->sock)
     {
         sock_release(dev->sock);
@@ -151,17 +125,13 @@ void dnbd3_net_disconnect(dnbd3_device_t *dev)
 int dnbd3_net_send(void *data)
 {
     dnbd3_device_t *dev = data;
-    dnbd3_request_t dnbd3_request;
     struct request *blk_request;
+
+    dnbd3_request_t dnbd3_request;
     struct msghdr msg;
     struct kvec iov;
 
-    msg.msg_name = NULL;
-    msg.msg_namelen = 0;
-    msg.msg_control = NULL;
-    msg.msg_controllen = 0;
-    msg.msg_flags = MSG_WAITALL | MSG_NOSIGNAL; // No SIGPIPE
-
+    init_msghdr(msg);
     set_user_nice(current, -20);
 
     while (!kthread_should_stop() || !list_empty(&dev->request_queue_send))
@@ -178,31 +148,42 @@ int dnbd3_net_send(void *data)
         list_del_init(&blk_request->queuelist);
         spin_unlock_irq(&dev->blk_lock);
 
+        // what to do?
         switch (blk_request->cmd_type)
         {
-        case REQ_TYPE_SPECIAL:
-            dnbd3_request.cmd = CMD_GET_SERVERS;
-            break;
-
         case REQ_TYPE_FS:
             dnbd3_request.cmd = CMD_GET_BLOCK;
             dnbd3_request.offset = blk_rq_pos(blk_request) << 9; // *512
             dnbd3_request.size = blk_rq_bytes(blk_request); // bytes left to complete entire request
             break;
 
-        default:
-            printk("ERROR: Unknown command\n");
+        case REQ_TYPE_SPECIAL:
+            switch (blk_request->cmd_flags)
+            {
+            case REQ_GET_FILESIZE:
+                dnbd3_request.cmd = CMD_GET_SIZE;
+                dnbd3_request.vid = dev->vid;
+                dnbd3_request.rid = dev->rid;
+                break;
+            case REQ_GET_SERVERS:
+                dnbd3_request.cmd = CMD_GET_SERVERS;
+                break;
+            }
             break;
+
+        default:
+            printk("ERROR: Unknown command (Send)\n");
+            continue;
         }
 
+        // send net request
         memcpy(dnbd3_request.handle, &blk_request, sizeof(blk_request));
         iov.iov_base = &dnbd3_request;
         iov.iov_len = sizeof(dnbd3_request);
-
-        // send net request
         if (kernel_sendmsg(dev->sock, &msg, &iov, 1, sizeof(dnbd3_request)) <= 0)
             printk("ERROR: kernel_sendmsg\n");
 
+        // enqueue request to request_queue_receive
         spin_lock_irq(&dev->blk_lock);
         list_add_tail(&blk_request->queuelist, &dev->request_queue_receive);
         spin_unlock_irq(&dev->blk_lock);
@@ -214,27 +195,21 @@ int dnbd3_net_send(void *data)
 int dnbd3_net_receive(void *data)
 {
     dnbd3_device_t *dev = data;
+    struct request *blk_request, *tmp_request, *received_request;
+
     dnbd3_reply_t dnbd3_reply;
-    struct request *blk_request;
     struct msghdr msg;
     struct kvec iov;
     struct req_iterator iter;
     struct bio_vec *bvec;
+    void *kaddr;
     unsigned long flags;
     sigset_t blocked, oldset;
-    struct request *tmp_request, *received_request;
-    void *kaddr;
-    unsigned int size;
 
-    int i = 0;
-    //char a[15];
-
-    msg.msg_name = NULL;
-    msg.msg_namelen = 0;
-    msg.msg_control = NULL;
-    msg.msg_controllen = 0;
-    msg.msg_flags = MSG_WAITALL | MSG_NOSIGNAL; // No SIGPIPE
+    unsigned int size, i;
+    uint64_t filesize;
 
+    init_msghdr(msg);
     set_user_nice(current, -20);
 
     while (!kthread_should_stop() || !list_empty(&dev->request_queue_receive))
@@ -256,15 +231,67 @@ int dnbd3_net_receive(void *data)
         list_for_each_entry_safe(blk_request, tmp_request, &dev->request_queue_receive, queuelist)
         {
             if (blk_request != received_request)
-            continue;
+                continue;
 
             list_del_init(&blk_request->queuelist);
             break;
         }
         spin_unlock_irq(&dev->blk_lock);
 
+        // check if server send error
+        switch (dnbd3_reply.error)
+        {
+        case ERROR_SIZE:
+            printk("ERROR: Requested image does't exist\n");
+            kthread_stop(dev->thread_send);
+            del_timer(&dev->hb_timer);
+            sock_release(dev->sock);
+            kfree(blk_request);
+            dev->sock = NULL;
+            return -1;
+
+        case ERROR_RELOAD:
+            blk_request->cmd_type = REQ_TYPE_SPECIAL;
+            blk_request->cmd_flags = REQ_GET_FILESIZE;
+            list_add(&blk_request->queuelist, &dev->request_queue_send);
+            wake_up(&dev->process_queue_send);
+            continue;
+
+        }
+
+        // what to do?
         switch (dnbd3_reply.cmd)
         {
+        case CMD_GET_BLOCK:
+            // receive data and answer to block layer
+            rq_for_each_segment(bvec, blk_request, iter)
+            {
+                siginitsetinv(&blocked, sigmask(SIGKILL));
+                sigprocmask(SIG_SETMASK, &blocked, &oldset);
+
+                kaddr = kmap(bvec->bv_page) + bvec->bv_offset;
+                size = bvec->bv_len;
+                iov.iov_base = kaddr;
+                iov.iov_len = size;
+                kernel_recvmsg(dev->sock, &msg, &iov, 1, size, msg.msg_flags);
+                kunmap(bvec->bv_page);
+
+                sigprocmask(SIG_SETMASK, &oldset, NULL);
+            }
+            spin_lock_irqsave(&dev->blk_lock, flags);
+            __blk_end_request_all(blk_request, 0);
+            spin_unlock_irqrestore(&dev->blk_lock, flags);
+            continue;
+
+        case CMD_GET_SIZE:
+            iov.iov_base = &filesize;
+            iov.iov_len = sizeof(uint64_t);
+            kernel_recvmsg(dev->sock, &msg, &iov, 1, dnbd3_reply.size, msg.msg_flags);
+            set_capacity(dev->disk, filesize >> 9); /* 512 Byte blocks */
+            printk("INFO: Filesize %s: %llu\n", dev->disk->disk_name, filesize);
+            kfree(blk_request);
+            continue;
+
         case CMD_GET_SERVERS:
             dev->num_servers = dnbd3_reply.size / sizeof(struct in_addr);
             size = sizeof(struct in_addr);
@@ -273,38 +300,15 @@ int dnbd3_net_receive(void *data)
                 iov.iov_base = &dev->servers[i];
                 iov.iov_len = size;
                 kernel_recvmsg(dev->sock, &msg, &iov, 1, size, msg.msg_flags);
-
-//                inet_ntoa(dev->servers[i], a);
-//                printk("INFO: Server[%i] %s\n", i, a);
             }
-            break;
-
-        case CMD_GET_BLOCK:
-            // receive data and answer to block layer
-            rq_for_each_segment(bvec, blk_request, iter)
-                {
-                    siginitsetinv(&blocked, sigmask(SIGKILL));
-                    sigprocmask(SIG_SETMASK, &blocked, &oldset);
-
-                    kaddr = kmap(bvec->bv_page) + bvec->bv_offset;
-                    size = bvec->bv_len;
-                    iov.iov_base = kaddr;
-                    iov.iov_len = size;
-                    kernel_recvmsg(dev->sock, &msg, &iov, 1, size, msg.msg_flags);
-                    kunmap(bvec->bv_page);
-
-                    sigprocmask(SIG_SETMASK, &oldset, NULL);
-                }
-            spin_lock_irqsave(&dev->blk_lock, flags);
-            __blk_end_request_all(blk_request, 0);
-            spin_unlock_irqrestore(&dev->blk_lock, flags);
-            break;
+            kfree(blk_request);
+            continue;
 
         default:
-            printk("ERROR: Unknown command\n");
-            break;
-        }
+            printk("ERROR: Unknown command (Receive)\n");
+            continue;
 
+        }
     }
     return 0;
 }
@@ -312,8 +316,14 @@ int dnbd3_net_receive(void *data)
 void dnbd3_net_heartbeat(unsigned long arg)
 {
     dnbd3_device_t *dev = (dnbd3_device_t *) arg;
-    list_add(&dev->hb_request.queuelist, &dev->request_queue_send);
-    wake_up(&dev->process_queue_send);
+    struct request *req = kmalloc(sizeof(struct request), GFP_ATOMIC);
+    if (req)
+    {
+        req->cmd_type = REQ_TYPE_SPECIAL;
+        req->cmd_flags = REQ_GET_SERVERS;
+        list_add(&req->queuelist, &dev->request_queue_send);
+        wake_up(&dev->process_queue_send);
+    }
     dev->hb_timer.expires = jiffies + HB_INTERVAL;
     add_timer(&dev->hb_timer);
 }
diff --git a/src/kernel/net.h b/src/kernel/net.h
index b9b31a4..ac5d8a4 100644
--- a/src/kernel/net.h
+++ b/src/kernel/net.h
@@ -23,6 +23,13 @@
 
 #include "dnbd3.h"
 
+#define init_msghdr(h)\
+        h.msg_name = NULL;\
+        h.msg_namelen = 0;\
+        h.msg_control = NULL;\
+        h.msg_controllen = 0;\
+        h.msg_flags = MSG_WAITALL | MSG_NOSIGNAL;
+
 void dnbd3_net_connect(dnbd3_device_t *lo);
 
 void dnbd3_net_disconnect(dnbd3_device_t *lo);
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);
 }
 
diff --git a/src/types.h b/src/types.h
index 8fdfbba..c236db9 100644
--- a/src/types.h
+++ b/src/types.h
@@ -42,6 +42,9 @@ typedef struct
 #define CMD_GET_SIZE    2
 #define CMD_GET_SERVERS 3
 
+#define ERROR_SIZE   1
+#define ERROR_RELOAD 2
+
 #pragma pack(1)
 typedef struct
 {
@@ -58,6 +61,7 @@ typedef struct
 typedef struct
 {
     uint16_t cmd;   // 2byte
+    uint16_t error; // 2byte
     uint64_t size;  // 8byte
     char handle[8]; // 8byte
 } dnbd3_reply_t;