Patch from Stephen Hemminger <shemminger@osdl.org>

Remove brlock from snap and vlan.

Change in snap unregister path from earlier version to use synchronize_kernel.

This code needs further testing before final 2.5 inclusion.
(Kind of wonder if anyone actually ever uses this?)



 25-akpm/net/802/psnap.c      |   24 +++++++++++-------------
 25-akpm/net/8021q/vlan.c     |    8 ++++----
 25-akpm/net/8021q/vlan_dev.c |    1 -
 3 files changed, 15 insertions(+), 18 deletions(-)

diff -puN net/8021q/vlan.c~brlock-removal-2 net/8021q/vlan.c
--- 25/net/8021q/vlan.c~brlock-removal-2	Thu Mar 13 15:14:34 2003
+++ 25-akpm/net/8021q/vlan.c	Thu Mar 13 15:14:34 2003
@@ -29,7 +29,6 @@
 #include <net/p8022.h>
 #include <net/arp.h>
 #include <linux/rtnetlink.h>
-#include <linux/brlock.h>
 #include <linux/notifier.h>
 
 #include <linux/if_vlan.h>
@@ -68,7 +67,6 @@ static struct packet_type vlan_packet_ty
 	.dev =NULL,
 	.func = vlan_skb_recv, /* VLAN receive method */
 	.data = (void *)(-1),  /* Set here '(void *)1' when this code can SHARE SKBs */
-	.next = NULL
 };
 
 /* End of global variables definitions. */
@@ -231,9 +229,11 @@ static int unregister_vlan_dev(struct ne
 				real_dev->vlan_rx_kill_vid(real_dev, vlan_id);
 			}
 
-			br_write_lock(BR_NETPROTO_LOCK);
 			grp->vlan_devices[vlan_id] = NULL;
-			br_write_unlock(BR_NETPROTO_LOCK);
+
+			/* wait for RCU in network receive */
+			smp_wmb();
+			synchronize_kernel();
 
 
 			/* Caller unregisters (and if necessary, puts)
diff -puN net/8021q/vlan_dev.c~brlock-removal-2 net/8021q/vlan_dev.c
--- 25/net/8021q/vlan_dev.c~brlock-removal-2	Thu Mar 13 15:14:34 2003
+++ 25-akpm/net/8021q/vlan_dev.c	Thu Mar 13 15:14:34 2003
@@ -31,7 +31,6 @@
 #include <net/datalink.h>
 #include <net/p8022.h>
 #include <net/arp.h>
-#include <linux/brlock.h>
 
 #include "vlan.h"
 #include "vlanproc.h"
diff -puN net/802/psnap.c~brlock-removal-2 net/802/psnap.c
--- 25/net/802/psnap.c~brlock-removal-2	Thu Mar 13 15:14:34 2003
+++ 25-akpm/net/802/psnap.c	Thu Mar 13 15:14:34 2003
@@ -21,10 +21,10 @@
 #include <linux/mm.h>
 #include <linux/in.h>
 #include <linux/init.h>
-#include <linux/brlock.h>
 
 LIST_HEAD(snap_list);
 static struct llc_sap *snap_sap;
+static spinlock_t snap_lock = SPIN_LOCK_UNLOCKED;
 
 /*
  *	Find a snap client by matching the 5 bytes.
@@ -34,17 +34,15 @@ static struct datalink_proto *find_snap_
 	struct list_head *entry;
 	struct datalink_proto *proto = NULL, *p;
 
-	if (list_empty(&snap_list))
-		goto out;
-
-	list_for_each(entry, &snap_list) {
+	rcu_read_lock();
+	list_for_each_rcu(entry, &snap_list) {
 		p = list_entry(entry, struct datalink_proto, node);
 		if (!memcmp(p->type, desc, 5)) {
 			proto = p;
 			break;
 		}
 	}
-out:
+	rcu_read_unlock();
 	return proto;
 }
 
@@ -124,8 +122,7 @@ struct datalink_proto *register_snap_cli
 {
 	struct datalink_proto *proto = NULL;
 
-	br_write_lock_bh(BR_NETPROTO_LOCK);
-
+	spin_lock_bh(&snap_lock);
 	if (find_snap_client(desc))
 		goto out;
 
@@ -135,10 +132,10 @@ struct datalink_proto *register_snap_cli
 		proto->rcvfunc		= rcvfunc;
 		proto->header_length	= 5 + 3; /* snap + 802.2 */
 		proto->request		= snap_request;
-		list_add(&proto->node, &snap_list);
+		list_add_rcu(&proto->node, &snap_list);
 	}
 out:
-	br_write_unlock_bh(BR_NETPROTO_LOCK);
+	spin_unlock_bh(&snap_lock);
 	return proto;
 }
 
@@ -147,12 +144,13 @@ out:
  */
 void unregister_snap_client(struct datalink_proto *proto)
 {
-	br_write_lock_bh(BR_NETPROTO_LOCK);
+	spin_lock_bh(&snap_lock);
+	list_del_rcu(&proto->node);
+	spin_unlock_bh(&snap_lock);
 
-	list_del(&proto->node);
+	synchronize_kernel();	/* wait for RCU */
 	kfree(proto);
 
-	br_write_unlock_bh(BR_NETPROTO_LOCK);
 }
 
 MODULE_LICENSE("GPL");

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