sunrpc: Add a function to close temporary transports immediately

Add a function svc_age_temp_xprts_now() to close temporary transports
whose xpt_local matches the address passed in server_addr immediately
instead of waiting for them to be closed by the timer function.

The function is intended to be used by notifier_blocks that will be
added to nfsd and lockd that will run when an ip address is deleted.

This will eliminate the ACK storms and client hangs that occur in
HA-NFS configurations where nfsd & lockd is left running on the cluster
nodes all the time and the NFS 'service' is migrated back and forth
within a short timeframe.

Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

diff --git a/include/linux/sunrpc/svc_xprt.h b/include/linux/sunrpc/svc_xprt.h
index 78512cfe1fe687f251e111e7d70be56540249a17..b7dabc4baafd817d0b2a41c5cf8e54e4b3fddc47 100644 (file)
--- a/include/linux/sunrpc/svc_xprt.h
+++ b/include/linux/sunrpc/svc_xprt.h
@@ -128,6 +128,7 @@ struct      svc_xprt *svc_find_xprt(struct svc_serv *serv, const char *xcl_name,
                        const unsigned short port);
 int    svc_xprt_names(struct svc_serv *serv, char *buf, const int buflen);
 void   svc_add_new_perm_xprt(struct svc_serv *serv, struct svc_xprt *xprt);
+void   svc_age_temp_xprts_now(struct svc_serv *, struct sockaddr *);
 
 static inline void svc_xprt_get(struct svc_xprt *xprt)
 {

diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
index a6cbb2104667d22e6b64ffa34718f8ed1f50ef0e..7422f28818b24de5e7b36eca01ac2e91f9a7cd4f 100644 (file)
--- a/net/sunrpc/svc_xprt.c
+++ b/net/sunrpc/svc_xprt.c
@@ -10,11 +10,13 @@
 #include <linux/kthread.h>
 #include <linux/slab.h>
 #include <net/sock.h>
+#include <linux/sunrpc/addr.h>
 #include <linux/sunrpc/stats.h>
 #include <linux/sunrpc/svc_xprt.h>
 #include <linux/sunrpc/svcsock.h>
 #include <linux/sunrpc/xprt.h>
 #include <linux/module.h>
+#include <linux/netdevice.h>
 #include <trace/events/sunrpc.h>
 
 #define RPCDBG_FACILITY        RPCDBG_SVCXPRT
@@ -938,6 +940,49 @@ static void svc_age_temp_xprts(unsigned long closure)
        mod_timer(&serv->sv_temptimer, jiffies + svc_conn_age_period * HZ);
 }
 
+/* Close temporary transports whose xpt_local matches server_addr immediately
+ * instead of waiting for them to be picked up by the timer.
+ *
+ * This is meant to be called from a notifier_block that runs when an ip
+ * address is deleted.
+ */
+void svc_age_temp_xprts_now(struct svc_serv *serv, struct sockaddr *server_addr)
+{
+       struct svc_xprt *xprt;
+       struct svc_sock *svsk;
+       struct socket *sock;
+       struct list_head *le, *next;
+       LIST_HEAD(to_be_closed);
+       struct linger no_linger = {
+               .l_onoff = 1,
+               .l_linger = 0,
+       };
+
+       spin_lock_bh(&serv->sv_lock);
+       list_for_each_safe(le, next, &serv->sv_tempsocks) {
+               xprt = list_entry(le, struct svc_xprt, xpt_list);
+               if (rpc_cmp_addr(server_addr, (struct sockaddr *)
+                               &xprt->xpt_local)) {
+                       dprintk("svc_age_temp_xprts_now: found %p\n", xprt);
+                       list_move(le, &to_be_closed);
+               }
+       }
+       spin_unlock_bh(&serv->sv_lock);
+
+       while (!list_empty(&to_be_closed)) {
+               le = to_be_closed.next;
+               list_del_init(le);
+               xprt = list_entry(le, struct svc_xprt, xpt_list);
+               dprintk("svc_age_temp_xprts_now: closing %p\n", xprt);
+               svsk = container_of(xprt, struct svc_sock, sk_xprt);
+               sock = svsk->sk_sock;
+               kernel_setsockopt(sock, SOL_SOCKET, SO_LINGER,
+                                 (char *)&no_linger, sizeof(no_linger));
+               svc_close_xprt(xprt);
+       }
+}
+EXPORT_SYMBOL_GPL(svc_age_temp_xprts_now);
+
 static void call_xpt_users(struct svc_xprt *xprt)
 {
        struct svc_xpt_user *u;