[PATCH] (1/4) remove hashbin from irlan

[Stephen Hemminger <shemminger@xxxxxxxx>]

The locking in hashbin_delete is a problem since unregister_netdevice
can't be called with locks held in 2.6.0-test3.

Replace it with simpler list macros.
Insertion/deletion protected with RTNL semaphore, and read
uses RCU.

Don't have client hardware to test, but load/unload works on SMP.

diff -Nru a/include/net/irda/irlan_common.h b/include/net/irda/irlan_common.h
--- a/include/net/irda/irlan_common.h   Mon Aug 18 11:09:06 2003
+++ b/include/net/irda/irlan_common.h   Mon Aug 18 11:09:06 2003
@@ -33,7 +33,6 @@
 #include <linux/skbuff.h>
 #include <linux/netdevice.h>
 
-#include <net/irda/irqueue.h>
 #include <net/irda/irttp.h>
 
 #define IRLAN_MTU        1518
@@ -161,9 +160,8 @@
  *  IrLAN control block
  */
 struct irlan_cb {
-       irda_queue_t q; /* Must be first */
-
        int    magic;
+       struct list_head  dev_list;
        struct net_device dev;        /* Ethernet device structure*/
        struct net_device_stats stats;
 
@@ -204,6 +202,7 @@
 
 int irlan_run_ctrl_tx_queue(struct irlan_cb *self);
 
+struct irlan_cb *irlan_get_any(void);
 void irlan_get_provider_info(struct irlan_cb *self);
 void irlan_get_unicast_addr(struct irlan_cb *self);
 void irlan_get_media_char(struct irlan_cb *self);
@@ -221,8 +220,6 @@
 
 int irlan_extract_param(__u8 *buf, char *name, char *value, __u16 *len);
 void print_ret_code(__u8 code);
-
-extern hashbin_t *irlan;
 
 #endif
 
diff -Nru a/net/irda/irlan/irlan_client.c b/net/irda/irlan/irlan_client.c
--- a/net/irda/irlan/irlan_client.c     Mon Aug 18 11:09:06 2003
+++ b/net/irda/irlan/irlan_client.c     Mon Aug 18 11:09:06 2003
@@ -154,7 +154,6 @@
        
        IRDA_DEBUG(1, "%s()\n", __FUNCTION__ );
 
-       ASSERT(irlan != NULL, return;);
        ASSERT(discovery != NULL, return;);
 
        /*
@@ -170,7 +169,8 @@
        daddr = discovery->daddr;
 
        /* Find instance */
-       self = (struct irlan_cb *) hashbin_get_first(irlan);
+       rcu_read_lock();
+       self = irlan_get_any();
        if (self) {
                ASSERT(self->magic == IRLAN_MAGIC, return;);
 
@@ -179,6 +179,7 @@
                
                irlan_client_wakeup(self, saddr, daddr);
        }
+       rcu_read_unlock();
 }
        
 /*
diff -Nru a/net/irda/irlan/irlan_common.c b/net/irda/irlan/irlan_common.c
--- a/net/irda/irlan/irlan_common.c     Mon Aug 18 11:09:06 2003
+++ b/net/irda/irlan/irlan_common.c     Mon Aug 18 11:09:06 2003
@@ -33,6 +33,7 @@
 #include <linux/proc_fs.h>
 #include <linux/netdevice.h>
 #include <linux/etherdevice.h>
+#include <linux/rtnetlink.h>
 
 #include <asm/system.h>
 #include <asm/bitops.h>
@@ -63,7 +64,8 @@
 /*
  *  Master structure
  */
-hashbin_t *irlan = NULL;
+static LIST_HEAD(irlans);
+
 static void *ckey;
 static void *skey;
 
@@ -124,12 +126,6 @@
        __u16 hints;
 
        IRDA_DEBUG(0, "%s()\n", __FUNCTION__ );
-       /* Allocate master structure */
-       irlan = hashbin_new(HB_LOCK);   /* protect from /proc */
-       if (irlan == NULL) {
-               printk(KERN_WARNING "IrLAN: Can't allocate hashbin!\n");
-               return -ENOMEM;
-       }
 #ifdef CONFIG_PROC_FS
        create_proc_info_entry("irlan", 0, proc_irda, irlan_proc_read);
 #endif /* CONFIG_PROC_FS */
@@ -158,6 +154,8 @@
 
 void __exit irlan_cleanup(void) 
 {
+       struct irlan_cb *self, *next;
+
        IRDA_DEBUG(4, "%s()\n", __FUNCTION__ );
 
        irlmp_unregister_client(ckey);
@@ -166,10 +164,13 @@
 #ifdef CONFIG_PROC_FS
        remove_proc_entry("irlan", proc_irda);
 #endif /* CONFIG_PROC_FS */
-       /*
-        *  Delete hashbin and close all irlan client instances in it
-        */
-       hashbin_delete(irlan, (FREE_FUNC) __irlan_close);
+
+       /* Cleanup any leftover network devices */
+       rtnl_lock();
+       list_for_each_entry_safe(self, next, &irlans, dev_list) {
+               __irlan_close(self);
+       }
+       rtnl_unlock();
 }
 
 /*
@@ -210,7 +211,6 @@
        struct irlan_cb *self;
 
        IRDA_DEBUG(2, "%s()\n", __FUNCTION__ );
-       ASSERT(irlan != NULL, return NULL;);
 
        /* 
         *  Initialize the irlan structure. 
@@ -243,7 +243,7 @@
        init_timer(&self->client.kick_timer);
        init_waitqueue_head(&self->open_wait);  
 
-       hashbin_insert(irlan, (irda_queue_t *) self, daddr, NULL);
+       list_add_rcu(&self->dev_list, &irlans);
        
        skb_queue_head_init(&self->client.txq);
        
@@ -258,8 +258,7 @@
  * Function __irlan_close (self)
  *
  *    This function closes and deallocates the IrLAN client instances. Be 
- *    aware that other functions which calles client_close() must call 
- *    hashbin_remove() first!!!
+ *    aware that other functions which calles client_close()
  */
 static void __irlan_close(struct irlan_cb *self)
 {
@@ -267,6 +266,7 @@
 
        IRDA_DEBUG(2, "%s()\n", __FUNCTION__ );
        
+       ASSERT_RTNL();
        ASSERT(self != NULL, return;);
        ASSERT(self->magic == IRLAN_MAGIC, return;);
 
@@ -283,12 +283,23 @@
        while ((skb = skb_dequeue(&self->client.txq)))
                dev_kfree_skb(skb);
 
-       unregister_netdev(&self->dev);
+       unregister_netdevice(&self->dev);
        
        self->magic = 0;
        kfree(self);
 }
 
+/* Find any instance of irlan, used for client discovery wakeup */
+struct irlan_cb *irlan_get_any(void)
+{
+       struct irlan_cb *self;
+
+       list_for_each_entry_rcu(self, &irlans, dev_list) {
+               return self;
+       }
+       return NULL;
+}
+
 /*
  * Function irlan_connect_indication (instance, sap, qos, max_sdu_size, skb)
  *
@@ -1086,18 +1097,16 @@
  */
 static int irlan_proc_read(char *buf, char **start, off_t offset, int len)
 {
-       struct irlan_cb *self;
-       unsigned long flags;
-       ASSERT(irlan != NULL, return 0;);
+       struct irlan_cb *self;
      
        len = 0;
        
-       spin_lock_irqsave(&irlan->hb_spinlock, flags);
+       rcu_read_lock();
 
        len += sprintf(buf+len, "IrLAN instances:\n");
        
-       self = (struct irlan_cb *) hashbin_get_first(irlan);
-       while (self != NULL) {
+       list_for_each_entry_rcu(self, &irlans, dev_list) {
+
                ASSERT(self->magic == IRLAN_MAGIC, break;);
                
                len += sprintf(buf+len, "ifname: %s,\n",
@@ -1126,10 +1135,8 @@
                               netif_queue_stopped(&self->dev) ? "TRUE" : 
"FALSE");
                        
                len += sprintf(buf+len, "\n");
-
-               self = (struct irlan_cb *) hashbin_get_next(irlan);
        } 
-       spin_unlock_irqrestore(&irlan->hb_spinlock, flags);
+       rcu_read_unlock();
 
        return len;
 }