staging: unisys: simplify destroy_bus() in uislib.c

The destroy_bus() function is heavily indented and many lines extend past the
right margin. This patch simplifies the function without changing its effects.

Signed-off-by: Benjamin Romer <benjamin.romer@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/unisys/uislib/uislib.c b/drivers/staging/unisys/uislib/uislib.c
index 84f40a2..17cfc21 100644 (file)
--- a/drivers/staging/unisys/uislib/uislib.c
+++ b/drivers/staging/unisys/uislib/uislib.c
@@ -276,53 +276,19 @@ destroy_bus(CONTROLVM_MESSAGE *msg, char *buf)
 {
        int i;
        struct bus_info *bus, *prev = NULL;
+       struct guest_msgs cmd;
        u32 busNo;
 
        busNo = msg->cmd.destroyBus.busNo;
 
-       /* find and delete the bus */
        read_lock(&BusListLock);
-       for (bus = BusListHead; bus; prev = bus, bus = bus->next) {
-               if (bus->busNo == busNo) {
-                       /* found the bus - ensure that all device
-                        * slots are NULL
-                        */
-                       for (i = 0; i < bus->deviceCount; i++) {
-                               if (bus->device[i] != NULL) {
-                                       LOGERR("CONTROLVM_BUS_DESTROY Failed: device %i attached to bus %d.",
-                                            i, busNo);
-                                       read_unlock(&BusListLock);
-                                       return CONTROLVM_RESP_ERROR_BUS_DEVICE_ATTACHED;
-                               }
-                       }
-                       read_unlock(&BusListLock);
-                       /* the msg is bound for virtpci; send
-                        * guest_msgs struct to callback
-                        */
-                       if (!msg->hdr.Flags.server) {
-                               struct guest_msgs cmd;
 
-                               cmd.msgtype = GUEST_DEL_VBUS;
-                               cmd.del_vbus.busNo = busNo;
-                               if (!VirtControlChanFunc) {
-                                       LOGERR("CONTROLVM_BUS_DESTROY Failed: virtpci callback not registered.");
-                                       return CONTROLVM_RESP_ERROR_VIRTPCI_DRIVER_FAILURE;
-                               }
-                               if (!VirtControlChanFunc(&cmd)) {
-                                       LOGERR("CONTROLVM_BUS_DESTROY Failed: virtpci GUEST_DEL_VBUS returned error.");
-                                       return CONTROLVM_RESP_ERROR_VIRTPCI_DRIVER_CALLBACK_ERROR;
-                               }
-                       }
-                       /* remove the bus from the list */
-                       write_lock(&BusListLock);
-                       if (prev)       /* not at head */
-                               prev->next = bus->next;
-                       else
-                               BusListHead = bus->next;
-                       BusListCount--;
-                       write_unlock(&BusListLock);
+       bus = BusListHead;
+       while (bus) {
+               if (bus->busNo == busNo)
                        break;
-               }
+               prev = bus;
+               bus = bus->next;
        }
 
        if (!bus) {
@@ -331,6 +297,44 @@ destroy_bus(CONTROLVM_MESSAGE *msg, char *buf)
                read_unlock(&BusListLock);
                return CONTROLVM_RESP_ERROR_ALREADY_DONE;
        }
+
+       /* verify that this bus has no devices. */
+       for (i = 0; i < bus->deviceCount; i++) {
+               if (bus->device[i] != NULL) {
+                       LOGERR("CONTROLVM_BUS_DESTROY Failed: device %i attached to bus %d.",
+                            i, busNo);
+                       read_unlock(&BusListLock);
+                       return CONTROLVM_RESP_ERROR_BUS_DEVICE_ATTACHED;
+               }
+       }
+       read_unlock(&BusListLock);
+
+       if (msg->hdr.Flags.server)
+               goto remove;
+
+       /* client messages require us to call the virtpci callback associated
+          with this bus. */
+       cmd.msgtype = GUEST_DEL_VBUS;
+       cmd.del_vbus.busNo = busNo;
+       if (!VirtControlChanFunc) {
+               LOGERR("CONTROLVM_BUS_DESTROY Failed: virtpci callback not registered.");
+               return CONTROLVM_RESP_ERROR_VIRTPCI_DRIVER_FAILURE;
+       }
+       if (!VirtControlChanFunc(&cmd)) {
+               LOGERR("CONTROLVM_BUS_DESTROY Failed: virtpci GUEST_DEL_VBUS returned error.");
+               return CONTROLVM_RESP_ERROR_VIRTPCI_DRIVER_CALLBACK_ERROR;
+       }
+
+       /* finally, remove the bus from the list */
+remove:
+       write_lock(&BusListLock);
+       if (prev)       /* not at head */
+               prev->next = bus->next;
+       else
+               BusListHead = bus->next;
+       BusListCount--;
+       write_unlock(&BusListLock);
+
        if (bus->pBusChannel) {
                uislib_iounmap(bus->pBusChannel);
                bus->pBusChannel = NULL;