]> git.kernelconcepts.de Git - karo-tx-linux.git/blobdiff - net/vmw_vsock/vmci_transport.c
Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[karo-tx-linux.git] / net / vmw_vsock / vmci_transport.c
index 1f63daff39659e08561862cfd71220ffc6949291..7555cad83a752a930a54e4a8ca609846386e0ec1 100644 (file)
 
 static int vmci_transport_recv_dgram_cb(void *data, struct vmci_datagram *dg);
 static int vmci_transport_recv_stream_cb(void *data, struct vmci_datagram *dg);
-static void vmci_transport_peer_attach_cb(u32 sub_id,
-                                         const struct vmci_event_data *ed,
-                                         void *client_data);
 static void vmci_transport_peer_detach_cb(u32 sub_id,
                                          const struct vmci_event_data *ed,
                                          void *client_data);
 static void vmci_transport_recv_pkt_work(struct work_struct *work);
+static void vmci_transport_cleanup(struct work_struct *work);
 static int vmci_transport_recv_listen(struct sock *sk,
                                      struct vmci_transport_packet *pkt);
 static int vmci_transport_recv_connecting_server(
@@ -75,6 +73,10 @@ struct vmci_transport_recv_pkt_info {
        struct vmci_transport_packet pkt;
 };
 
+static LIST_HEAD(vmci_transport_cleanup_list);
+static DEFINE_SPINLOCK(vmci_transport_cleanup_lock);
+static DECLARE_WORK(vmci_transport_cleanup_work, vmci_transport_cleanup);
+
 static struct vmci_handle vmci_transport_stream_handle = { VMCI_INVALID_ID,
                                                           VMCI_INVALID_ID };
 static u32 vmci_transport_qp_resumed_sub_id = VMCI_INVALID_ID;
@@ -791,44 +793,6 @@ out:
        return err;
 }
 
-static void vmci_transport_peer_attach_cb(u32 sub_id,
-                                         const struct vmci_event_data *e_data,
-                                         void *client_data)
-{
-       struct sock *sk = client_data;
-       const struct vmci_event_payload_qp *e_payload;
-       struct vsock_sock *vsk;
-
-       e_payload = vmci_event_data_const_payload(e_data);
-
-       vsk = vsock_sk(sk);
-
-       /* We don't ask for delayed CBs when we subscribe to this event (we
-        * pass 0 as flags to vmci_event_subscribe()).  VMCI makes no
-        * guarantees in that case about what context we might be running in,
-        * so it could be BH or process, blockable or non-blockable.  So we
-        * need to account for all possible contexts here.
-        */
-       local_bh_disable();
-       bh_lock_sock(sk);
-
-       /* XXX This is lame, we should provide a way to lookup sockets by
-        * qp_handle.
-        */
-       if (vmci_handle_is_equal(vmci_trans(vsk)->qp_handle,
-                                e_payload->handle)) {
-               /* XXX This doesn't do anything, but in the future we may want
-                * to set a flag here to verify the attach really did occur and
-                * we weren't just sent a datagram claiming it was.
-                */
-               goto out;
-       }
-
-out:
-       bh_unlock_sock(sk);
-       local_bh_enable();
-}
-
 static void vmci_transport_handle_detach(struct sock *sk)
 {
        struct vsock_sock *vsk;
@@ -871,28 +835,38 @@ static void vmci_transport_peer_detach_cb(u32 sub_id,
                                          const struct vmci_event_data *e_data,
                                          void *client_data)
 {
-       struct sock *sk = client_data;
+       struct vmci_transport *trans = client_data;
        const struct vmci_event_payload_qp *e_payload;
-       struct vsock_sock *vsk;
 
        e_payload = vmci_event_data_const_payload(e_data);
-       vsk = vsock_sk(sk);
-       if (vmci_handle_is_invalid(e_payload->handle))
-               return;
-
-       /* Same rules for locking as for peer_attach_cb(). */
-       local_bh_disable();
-       bh_lock_sock(sk);
 
        /* XXX This is lame, we should provide a way to lookup sockets by
         * qp_handle.
         */
-       if (vmci_handle_is_equal(vmci_trans(vsk)->qp_handle,
-                                e_payload->handle))
-               vmci_transport_handle_detach(sk);
+       if (vmci_handle_is_invalid(e_payload->handle) ||
+           vmci_handle_is_equal(trans->qp_handle, e_payload->handle))
+               return;
 
-       bh_unlock_sock(sk);
-       local_bh_enable();
+       /* We don't ask for delayed CBs when we subscribe to this event (we
+        * pass 0 as flags to vmci_event_subscribe()).  VMCI makes no
+        * guarantees in that case about what context we might be running in,
+        * so it could be BH or process, blockable or non-blockable.  So we
+        * need to account for all possible contexts here.
+        */
+       spin_lock_bh(&trans->lock);
+       if (!trans->sk)
+               goto out;
+
+       /* Apart from here, trans->lock is only grabbed as part of sk destruct,
+        * where trans->sk isn't locked.
+        */
+       bh_lock_sock(trans->sk);
+
+       vmci_transport_handle_detach(trans->sk);
+
+       bh_unlock_sock(trans->sk);
+ out:
+       spin_unlock_bh(&trans->lock);
 }
 
 static void vmci_transport_qp_resumed_cb(u32 sub_id,
@@ -1181,7 +1155,7 @@ vmci_transport_recv_connecting_server(struct sock *listener,
         */
        err = vmci_event_subscribe(VMCI_EVENT_QP_PEER_DETACH,
                                   vmci_transport_peer_detach_cb,
-                                  pending, &detach_sub_id);
+                                  vmci_trans(vpending), &detach_sub_id);
        if (err < VMCI_SUCCESS) {
                vmci_transport_send_reset(pending, pkt);
                err = vmci_transport_error_to_vsock_error(err);
@@ -1321,7 +1295,6 @@ vmci_transport_recv_connecting_client(struct sock *sk,
                    || vmci_trans(vsk)->qpair
                    || vmci_trans(vsk)->produce_size != 0
                    || vmci_trans(vsk)->consume_size != 0
-                   || vmci_trans(vsk)->attach_sub_id != VMCI_INVALID_ID
                    || vmci_trans(vsk)->detach_sub_id != VMCI_INVALID_ID) {
                        skerr = EPROTO;
                        err = -EINVAL;
@@ -1389,7 +1362,6 @@ static int vmci_transport_recv_connecting_client_negotiate(
        struct vsock_sock *vsk;
        struct vmci_handle handle;
        struct vmci_qp *qpair;
-       u32 attach_sub_id;
        u32 detach_sub_id;
        bool is_local;
        u32 flags;
@@ -1399,7 +1371,6 @@ static int vmci_transport_recv_connecting_client_negotiate(
 
        vsk = vsock_sk(sk);
        handle = VMCI_INVALID_HANDLE;
-       attach_sub_id = VMCI_INVALID_ID;
        detach_sub_id = VMCI_INVALID_ID;
 
        /* If we have gotten here then we should be past the point where old
@@ -1444,23 +1415,15 @@ static int vmci_transport_recv_connecting_client_negotiate(
                goto destroy;
        }
 
-       /* Subscribe to attach and detach events first.
+       /* Subscribe to detach events first.
         *
         * XXX We attach once for each queue pair created for now so it is easy
         * to find the socket (it's provided), but later we should only
         * subscribe once and add a way to lookup sockets by queue pair handle.
         */
-       err = vmci_event_subscribe(VMCI_EVENT_QP_PEER_ATTACH,
-                                  vmci_transport_peer_attach_cb,
-                                  sk, &attach_sub_id);
-       if (err < VMCI_SUCCESS) {
-               err = vmci_transport_error_to_vsock_error(err);
-               goto destroy;
-       }
-
        err = vmci_event_subscribe(VMCI_EVENT_QP_PEER_DETACH,
                                   vmci_transport_peer_detach_cb,
-                                  sk, &detach_sub_id);
+                                  vmci_trans(vsk), &detach_sub_id);
        if (err < VMCI_SUCCESS) {
                err = vmci_transport_error_to_vsock_error(err);
                goto destroy;
@@ -1496,7 +1459,6 @@ static int vmci_transport_recv_connecting_client_negotiate(
        vmci_trans(vsk)->produce_size = vmci_trans(vsk)->consume_size =
                pkt->u.size;
 
-       vmci_trans(vsk)->attach_sub_id = attach_sub_id;
        vmci_trans(vsk)->detach_sub_id = detach_sub_id;
 
        vmci_trans(vsk)->notify_ops->process_negotiate(sk);
@@ -1504,9 +1466,6 @@ static int vmci_transport_recv_connecting_client_negotiate(
        return 0;
 
 destroy:
-       if (attach_sub_id != VMCI_INVALID_ID)
-               vmci_event_unsubscribe(attach_sub_id);
-
        if (detach_sub_id != VMCI_INVALID_ID)
                vmci_event_unsubscribe(detach_sub_id);
 
@@ -1607,9 +1566,11 @@ static int vmci_transport_socket_init(struct vsock_sock *vsk,
        vmci_trans(vsk)->qp_handle = VMCI_INVALID_HANDLE;
        vmci_trans(vsk)->qpair = NULL;
        vmci_trans(vsk)->produce_size = vmci_trans(vsk)->consume_size = 0;
-       vmci_trans(vsk)->attach_sub_id = vmci_trans(vsk)->detach_sub_id =
-               VMCI_INVALID_ID;
+       vmci_trans(vsk)->detach_sub_id = VMCI_INVALID_ID;
        vmci_trans(vsk)->notify_ops = NULL;
+       INIT_LIST_HEAD(&vmci_trans(vsk)->elem);
+       vmci_trans(vsk)->sk = &vsk->sk;
+       spin_lock_init(&vmci_trans(vsk)->lock);
        if (psk) {
                vmci_trans(vsk)->queue_pair_size =
                        vmci_trans(psk)->queue_pair_size;
@@ -1629,29 +1590,57 @@ static int vmci_transport_socket_init(struct vsock_sock *vsk,
        return 0;
 }
 
-static void vmci_transport_destruct(struct vsock_sock *vsk)
+static void vmci_transport_free_resources(struct list_head *transport_list)
 {
-       if (vmci_trans(vsk)->attach_sub_id != VMCI_INVALID_ID) {
-               vmci_event_unsubscribe(vmci_trans(vsk)->attach_sub_id);
-               vmci_trans(vsk)->attach_sub_id = VMCI_INVALID_ID;
-       }
+       while (!list_empty(transport_list)) {
+               struct vmci_transport *transport =
+                   list_first_entry(transport_list, struct vmci_transport,
+                                    elem);
+               list_del(&transport->elem);
 
-       if (vmci_trans(vsk)->detach_sub_id != VMCI_INVALID_ID) {
-               vmci_event_unsubscribe(vmci_trans(vsk)->detach_sub_id);
-               vmci_trans(vsk)->detach_sub_id = VMCI_INVALID_ID;
-       }
+               if (transport->detach_sub_id != VMCI_INVALID_ID) {
+                       vmci_event_unsubscribe(transport->detach_sub_id);
+                       transport->detach_sub_id = VMCI_INVALID_ID;
+               }
 
-       if (!vmci_handle_is_invalid(vmci_trans(vsk)->qp_handle)) {
-               vmci_qpair_detach(&vmci_trans(vsk)->qpair);
-               vmci_trans(vsk)->qp_handle = VMCI_INVALID_HANDLE;
-               vmci_trans(vsk)->produce_size = 0;
-               vmci_trans(vsk)->consume_size = 0;
+               if (!vmci_handle_is_invalid(transport->qp_handle)) {
+                       vmci_qpair_detach(&transport->qpair);
+                       transport->qp_handle = VMCI_INVALID_HANDLE;
+                       transport->produce_size = 0;
+                       transport->consume_size = 0;
+               }
+
+               kfree(transport);
        }
+}
+
+static void vmci_transport_cleanup(struct work_struct *work)
+{
+       LIST_HEAD(pending);
+
+       spin_lock_bh(&vmci_transport_cleanup_lock);
+       list_replace_init(&vmci_transport_cleanup_list, &pending);
+       spin_unlock_bh(&vmci_transport_cleanup_lock);
+       vmci_transport_free_resources(&pending);
+}
+
+static void vmci_transport_destruct(struct vsock_sock *vsk)
+{
+       /* Ensure that the detach callback doesn't use the sk/vsk
+        * we are about to destruct.
+        */
+       spin_lock_bh(&vmci_trans(vsk)->lock);
+       vmci_trans(vsk)->sk = NULL;
+       spin_unlock_bh(&vmci_trans(vsk)->lock);
 
        if (vmci_trans(vsk)->notify_ops)
                vmci_trans(vsk)->notify_ops->socket_destruct(vsk);
 
-       kfree(vsk->trans);
+       spin_lock_bh(&vmci_transport_cleanup_lock);
+       list_add(&vmci_trans(vsk)->elem, &vmci_transport_cleanup_list);
+       spin_unlock_bh(&vmci_transport_cleanup_lock);
+       schedule_work(&vmci_transport_cleanup_work);
+
        vsk->trans = NULL;
 }
 
@@ -2146,6 +2135,9 @@ module_init(vmci_transport_init);
 
 static void __exit vmci_transport_exit(void)
 {
+       cancel_work_sync(&vmci_transport_cleanup_work);
+       vmci_transport_free_resources(&vmci_transport_cleanup_list);
+
        if (!vmci_handle_is_invalid(vmci_transport_stream_handle)) {
                if (vmci_datagram_destroy_handle(
                        vmci_transport_stream_handle) != VMCI_SUCCESS)
@@ -2164,6 +2156,7 @@ module_exit(vmci_transport_exit);
 
 MODULE_AUTHOR("VMware, Inc.");
 MODULE_DESCRIPTION("VMCI transport for Virtual Sockets");
+MODULE_VERSION("1.0.2.0-k");
 MODULE_LICENSE("GPL v2");
 MODULE_ALIAS("vmware_vsock");
 MODULE_ALIAS_NETPROTO(PF_VSOCK);