vserver 2.0 rc7

[linux-2.6.git] / arch / um / drivers / port_kern.c

diff --git a/arch/um/drivers/port_kern.c b/arch/um/drivers/port_kern.c
index 14f66da..b5ee074 100644 (file)
--- a/arch/um/drivers/port_kern.c
+++ b/arch/um/drivers/port_kern.c
@@ -10,6 +10,7 @@
 #include "linux/irq.h"
 #include "linux/spinlock.h"
 #include "linux/errno.h"
+#include "asm/atomic.h"
 #include "asm/semaphore.h"
 #include "asm/errno.h"
 #include "kern_util.h"
@@ -22,8 +23,9 @@
 
 struct port_list {
        struct list_head list;
+       atomic_t wait_count;
        int has_connection;
-       struct semaphore sem;
+       struct completion done;
        int port;
        int fd;
        spinlock_t lock;
@@ -66,10 +68,17 @@ static irqreturn_t pipe_interrupt(int irq, void *data, struct pt_regs *regs)
        conn->fd = fd;
        list_add(&conn->list, &conn->port->connections);
 
-       up(&conn->port->sem);
+       complete(&conn->port->done);
        return(IRQ_HANDLED);
 }
 
+#define NO_WAITER_MSG \
+    "****\n" \
+    "There are currently no UML consoles waiting for port connections.\n" \
+    "Either disconnect from one to make it available or activate some more\n" \
+    "by enabling more consoles in the UML /etc/inittab.\n" \
+    "****\n"
+
 static int port_accept(struct port_list *port)
 {
        struct connection *conn;
@@ -104,6 +113,10 @@ static int port_accept(struct port_list *port)
                goto out_free;
        }
 
+       if(atomic_read(&port->wait_count) == 0){
+               os_write_file(fd, NO_WAITER_MSG, sizeof(NO_WAITER_MSG));
+               printk("No one waiting for port\n");
+       }
        list_add(&conn->list, &port->pending);
        return(1);
 
@@ -182,14 +195,14 @@ void *port_data(int port_num)
 
        *port = ((struct port_list) 
                { .list                 = LIST_HEAD_INIT(port->list),
+                 .wait_count           = ATOMIC_INIT(0),
                  .has_connection       = 0,
-                 .sem                  = __SEMAPHORE_INITIALIZER(port->sem, 
-                                                                 0),
-                 .lock                 = SPIN_LOCK_UNLOCKED,
                  .port                 = port_num,
                  .fd                   = fd,
                  .pending              = LIST_HEAD_INIT(port->pending),
                  .connections          = LIST_HEAD_INIT(port->connections) });
+       spin_lock_init(&port->lock);
+       init_completion(&port->done);
        list_add(&port->list, &ports);
 
  found:
@@ -220,9 +233,11 @@ int port_wait(void *data)
        struct port_list *port = dev->port;
        int fd;
 
+        atomic_inc(&port->wait_count);
        while(1){
-               if(down_interruptible(&port->sem))
-                       return(-ERESTARTSYS);
+               fd = -ERESTARTSYS;
+                if(wait_for_completion_interruptible(&port->done))
+                        goto out;
 
                spin_lock(&port->lock);
 
@@ -254,8 +269,9 @@ int port_wait(void *data)
        dev->helper_pid = conn->helper_pid;
        dev->telnetd_pid = conn->telnetd_pid;
        kfree(conn);
-
-       return(fd);
+ out:
+       atomic_dec(&port->wait_count);
+       return fd;
 }
 
 void port_remove_dev(void *d)
@@ -291,14 +307,3 @@ static void free_port(void)
 }
 
 __uml_exitcall(free_port);
-
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only.  This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */