[XFRM]: Allow XFRM_ACQ_EXPIRES to be tunable via sysctl.

Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index 9955ff4..372f06e 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -21,18 +21,21 @@
 #include <linux/cache.h>
 #include <asm/uaccess.h>
 #include <linux/audit.h>
+#include <linux/cache.h>
 
 #include "xfrm_hash.h"
 
 struct sock *xfrm_nl;
 EXPORT_SYMBOL(xfrm_nl);
 
-u32 sysctl_xfrm_aevent_etime = XFRM_AE_ETIME;
+u32 sysctl_xfrm_aevent_etime __read_mostly = XFRM_AE_ETIME;
 EXPORT_SYMBOL(sysctl_xfrm_aevent_etime);
 
-u32 sysctl_xfrm_aevent_rseqth = XFRM_AE_SEQT_SIZE;
+u32 sysctl_xfrm_aevent_rseqth __read_mostly = XFRM_AE_SEQT_SIZE;
 EXPORT_SYMBOL(sysctl_xfrm_aevent_rseqth);
 
+u32 sysctl_xfrm_acq_expires __read_mostly = 30;
+
 /* Each xfrm_state may be linked to two tables:
 
    1. Hash table by (spi,daddr,ah/esp) to find SA by SPI. (input,ctl)
@@ -622,8 +625,8 @@
 				h = xfrm_spi_hash(&x->id.daddr, x->id.spi, x->id.proto, family);
 				hlist_add_head(&x->byspi, xfrm_state_byspi+h);
 			}
-			x->lft.hard_add_expires_seconds = XFRM_ACQ_EXPIRES;
-			x->timer.expires = jiffies + XFRM_ACQ_EXPIRES*HZ;
+			x->lft.hard_add_expires_seconds = sysctl_xfrm_acq_expires;
+			x->timer.expires = jiffies + sysctl_xfrm_acq_expires*HZ;
 			add_timer(&x->timer);
 			xfrm_state_num++;
 			xfrm_hash_grow_check(x->bydst.next != NULL);
@@ -772,9 +775,9 @@
 		x->props.family = family;
 		x->props.mode = mode;
 		x->props.reqid = reqid;
-		x->lft.hard_add_expires_seconds = XFRM_ACQ_EXPIRES;
+		x->lft.hard_add_expires_seconds = sysctl_xfrm_acq_expires;
 		xfrm_state_hold(x);
-		x->timer.expires = jiffies + XFRM_ACQ_EXPIRES*HZ;
+		x->timer.expires = jiffies + sysctl_xfrm_acq_expires*HZ;
 		add_timer(&x->timer);
 		hlist_add_head(&x->bydst, xfrm_state_bydst+h);
 		h = xfrm_src_hash(daddr, saddr, family);