[PATCH][RFC] spin_trylock_bh

[Arnaldo Carvalho de Melo]

Hi,

	Please see if this is acceptable, I noticed this while working on
the locks for NetBEUI 8) Patch is against 2.4.9, but it should apply to
latest prepatch. It was being used in the ppp code for quite some time.

                        - Arnaldo

Index: include/linux/spinlock.h
===================================================================
RCS file: /home/cvs/kernel-acme/include/linux/spinlock.h,v
retrieving revision 1.1.1.2
diff -u -r1.1.1.2 spinlock.h
--- include/linux/spinlock.h	2001/08/16 21:48:34	1.1.1.2
+++ include/linux/spinlock.h	2001/09/15 20:16:44
@@ -30,6 +30,10 @@
 #define write_unlock_irqrestore(lock, flags)	do { write_unlock(lock); local_irq_restore(flags); } while (0)
 #define write_unlock_irq(lock)			do { write_unlock(lock); local_irq_enable();       } while (0)
 #define write_unlock_bh(lock)			do { write_unlock(lock); local_bh_enable();        } while (0)
+#define spin_trylock_bh(lock)			({ int __r; local_bh_disable();\
+						__r = spin_trylock(lock);      \
+						if (!__r) local_bh_enable();   \
+						__r; })
 
 #ifdef CONFIG_SMP
 #include <asm/spinlock.h>
Index: drivers/net/ppp_synctty.c
===================================================================
RCS file: /home/cvs/kernel-acme/drivers/net/ppp_synctty.c,v
retrieving revision 1.1.1.2
diff -u -r1.1.1.2 ppp_synctty.c
--- drivers/net/ppp_synctty.c	2001/08/16 21:45:05	1.1.1.2
+++ drivers/net/ppp_synctty.c	2001/09/15 20:16:47
@@ -44,13 +44,6 @@
 #include <linux/init.h>
 #include <asm/uaccess.h>
 
-#ifndef spin_trylock_bh
-#define spin_trylock_bh(lock)	({ int __r; local_bh_disable();	\
-				   __r = spin_trylock(lock);	\
-				   if (!__r) local_bh_enable();	\
-				   __r; })
-#endif
-
 #define PPP_VERSION	"2.4.1"
 
 /* Structure for storing local state. */
Index: net/ipv6/ip6_fib.c
===================================================================
RCS file: /home/cvs/kernel-acme/net/ipv6/ip6_fib.c,v
retrieving revision 1.1.1.2
diff -u -r1.1.1.2 ip6_fib.c
--- net/ipv6/ip6_fib.c	2001/08/16 18:44:10	1.1.1.2
+++ net/ipv6/ip6_fib.c	2001/09/15 20:16:50
@@ -1192,10 +1192,8 @@
 		spin_lock_bh(&fib6_gc_lock);
 		gc_args.timeout = (int)dummy;
 	} else {
-		local_bh_disable();
-		if (!spin_trylock(&fib6_gc_lock)) {
+		if (!spin_trylock_bh(&fib6_gc_lock)) {
 			mod_timer(&ip6_fib_timer, jiffies + HZ);
-			local_bh_enable();
 			return;
 		}
 		gc_args.timeout = ip6_rt_gc_interval;