SUNRPC: service destruction in network namespace context

v2: Added comment to BUG_ON's in svc_destroy() to make code looks clearer.

This patch introduces network namespace filter for service destruction
function.
Nothing special here - just do exactly the same operations, but only for
tranports in passed networks namespace context.
BTW, BUG_ON() checks for empty service transports lists were returned into
svc_destroy() function. This is because of swithing generic svc_close_all() to
networks namespace dependable svc_close_net().

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

3 files changed, 29 insertions, 13 deletions

diff --git a/include/linux/sunrpc/svcsock.h b/include/linux/sunrpc/svcsock.h
index c84e9741cb2..cb4ac69e1f3 100644
--- a/include/linux/sunrpc/svcsock.h
+++ b/include/linux/sunrpc/svcsock.h
@@ -34,7 +34,7 @@ struct svc_sock {
 /*
  * Function prototypes.
  */
-void            svc_close_all(struct svc_serv *);
+void            svc_close_net(struct svc_serv *, struct net *);
 int             svc_recv(struct svc_rqst *, long);
 int             svc_send(struct svc_rqst *);
 void            svc_drop(struct svc_rqst *);
diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
index a8b49a04461..6cc0ea3d26f 100644
--- a/net/sunrpc/svc.c
+++ b/net/sunrpc/svc.c
@@ -517,6 +517,8 @@ EXPORT_SYMBOL_GPL(svc_create_pooled);
 void
 svc_destroy(struct svc_serv *serv)
 {
+        struct net *net = current->nsproxy->net_ns;
+
         dprintk("svc: svc_destroy(%s, %d)\n",
                                 serv->sv_program->pg_name,
                                 serv->sv_nrthreads);
@@ -539,10 +541,17 @@ svc_destroy(struct svc_serv *serv)
          * caller is using--nfsd_mutex in the case of nfsd).  So it's
          * safe to traverse those lists and shut everything down:
          */
-        svc_close_all(serv);
+        svc_close_net(serv, net);
+
+        /*
+         * The last user is gone and thus all sockets have to be destroyed to
+         * the point. Check this.
+         */
+        BUG_ON(!list_empty(&serv->sv_permsocks));
+        BUG_ON(!list_empty(&serv->sv_tempsocks));
 
         if (serv->sv_shutdown)
-                serv->sv_shutdown(serv, current->nsproxy->net_ns);
+                serv->sv_shutdown(serv, net);
 
         cache_clean_deferred(serv);
 
diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
index 493e70b72b7..4bda09d7e1a 100644
--- a/net/sunrpc/svc_xprt.c
+++ b/net/sunrpc/svc_xprt.c
@@ -922,17 +922,19 @@ void svc_close_xprt(struct svc_xprt *xprt)
 }
 EXPORT_SYMBOL_GPL(svc_close_xprt);
 
-static void svc_close_list(struct list_head *xprt_list)
+static void svc_close_list(struct list_head *xprt_list, struct net *net)
 {
         struct svc_xprt *xprt;
 
         list_for_each_entry(xprt, xprt_list, xpt_list) {
+                if (xprt->xpt_net != net)
+                        continue;
                 set_bit(XPT_CLOSE, &xprt->xpt_flags);
                 set_bit(XPT_BUSY, &xprt->xpt_flags);
         }
 }
 
-static void svc_clear_pools(struct svc_serv *serv)
+static void svc_clear_pools(struct svc_serv *serv, struct net *net)
 {
         struct svc_pool *pool;
         struct svc_xprt *xprt;
@@ -944,36 +946,41 @@ static void svc_clear_pools(struct svc_serv *serv)
 
                 spin_lock_bh(&pool->sp_lock);
                 list_for_each_entry_safe(xprt, tmp, &pool->sp_sockets, xpt_ready) {
+                        if (xprt->xpt_net != net)
+                                continue;
                         list_del_init(&xprt->xpt_ready);
                 }
                 spin_unlock_bh(&pool->sp_lock);
         }
 }
 
-static void svc_clear_list(struct list_head *xprt_list)
+static void svc_clear_list(struct list_head *xprt_list, struct net *net)
 {
         struct svc_xprt *xprt;
         struct svc_xprt *tmp;
 
         list_for_each_entry_safe(xprt, tmp, xprt_list, xpt_list) {
+                if (xprt->xpt_net != net)
+                        continue;
                 svc_delete_xprt(xprt);
         }
-        BUG_ON(!list_empty(xprt_list));
+        list_for_each_entry(xprt, xprt_list, xpt_list)
+                BUG_ON(xprt->xpt_net == net);
 }
 
-void svc_close_all(struct svc_serv *serv)
+void svc_close_net(struct svc_serv *serv, struct net *net)
 {
-        svc_close_list(&serv->sv_tempsocks);
-        svc_close_list(&serv->sv_permsocks);
+        svc_close_list(&serv->sv_tempsocks, net);
+        svc_close_list(&serv->sv_permsocks, net);
 
-        svc_clear_pools(serv);
+        svc_clear_pools(serv, net);
         /*
          * At this point the sp_sockets lists will stay empty, since
          * svc_enqueue will not add new entries without taking the
          * sp_lock and checking XPT_BUSY.
          */
-        svc_clear_list(&serv->sv_tempsocks);
-        svc_clear_list(&serv->sv_permsocks);
+        svc_clear_list(&serv->sv_tempsocks, net);
+        svc_clear_list(&serv->sv_permsocks, net);
 }
 
 /*