[IPVS]: Add and reorder bh locks after moving to keventd.

An addition to the last ipvs changes that move
update_defense_level/si_meminfo to keventd:

- ip_vs_random_dropentry now runs in process context and should use _bh
  locks to protect from softirqs

- update_defense_level still needs _bh locks after si_meminfo is called,
  for the same purpose

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 9 insertions, 6 deletions

diff --git a/net/ipv4/ipvs/ip_vs_conn.c b/net/ipv4/ipvs/ip_vs_conn.c
index 9f16ab309106..d0145a8b1551 100644
--- a/net/ipv4/ipvs/ip_vs_conn.c
+++ b/net/ipv4/ipvs/ip_vs_conn.c
@@ -758,7 +758,7 @@ static inline int todrop_entry(struct ip_vs_conn *cp)
         return 1;
 }
 
-
+/* Called from keventd and must protect itself from softirqs */
 void ip_vs_random_dropentry(void)
 {
         int idx;
@@ -773,7 +773,7 @@ void ip_vs_random_dropentry(void)
                 /*
                  *  Lock is actually needed in this loop.
                  */
-                ct_write_lock(hash);
+                ct_write_lock_bh(hash);
 
                 list_for_each_entry(cp, &ip_vs_conn_tab[hash], c_list) {
                         if (!cp->cport && !(cp->flags & IP_VS_CONN_F_NO_CPORT))
@@ -806,7 +806,7 @@ void ip_vs_random_dropentry(void)
                                 ip_vs_conn_expire_now(cp->control);
                         }
                 }
-                ct_write_unlock(hash);
+                ct_write_unlock_bh(hash);
         }
 }
 
diff --git a/net/ipv4/ipvs/ip_vs_ctl.c b/net/ipv4/ipvs/ip_vs_ctl.c
index 12a82e91d22a..7d99ede2ef79 100644
--- a/net/ipv4/ipvs/ip_vs_ctl.c
+++ b/net/ipv4/ipvs/ip_vs_ctl.c
@@ -90,7 +90,8 @@ int ip_vs_get_debug_level(void)
 #endif
 
 /*
- *      update_defense_level is called from keventd and from sysctl.
+ *      update_defense_level is called from keventd and from sysctl,
+ *      so it needs to protect itself from softirqs
  */
 static void update_defense_level(void)
 {
@@ -110,6 +111,8 @@ static void update_defense_level(void)
 
         nomem = (availmem < sysctl_ip_vs_amemthresh);
 
+        local_bh_disable();
+
         /* drop_entry */
         spin_lock(&__ip_vs_dropentry_lock);
         switch (sysctl_ip_vs_drop_entry) {
@@ -206,6 +209,8 @@ static void update_defense_level(void)
         if (to_change >= 0)
                 ip_vs_protocol_timeout_change(sysctl_ip_vs_secure_tcp>1);
         write_unlock(&__ip_vs_securetcp_lock);
+
+        local_bh_enable();
 }
 
 
@@ -1360,9 +1365,7 @@ proc_do_defense_mode(ctl_table *table, int write, struct file * filp,
                         /* Restore the correct value */
                         *valp = val;
                 } else {
-                        local_bh_disable();
                         update_defense_level();
-                        local_bh_enable();
                 }
         }
         return rc;