Lockd: pass network namespace to creation and destruction routines

v2: dereference of most probably already released nlm_host removed in
nlmclnt_done() and reclaimer().

These routines are called from locks reclaimer() kernel thread. This thread
works in "init_net" network context and currently relays on persence on lockd
thread and it's per-net resources. Thus lockd_up() and lockd_down() can't relay
on current network context. So let's pass corrent one into them.

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

4 files changed, 16 insertions, 14 deletions

diff --git a/fs/lockd/clntlock.c b/fs/lockd/clntlock.c
index ba1dc2eebd1e..ca0a08001449 100644
--- a/fs/lockd/clntlock.c
+++ b/fs/lockd/clntlock.c
@@ -56,7 +56,7 @@ struct nlm_host *nlmclnt_init(const struct nlmclnt_initdata *nlm_init)
         u32 nlm_version = (nlm_init->nfs_version == 2) ? 1 : 4;
         int status;
 
-        status = lockd_up();
+        status = lockd_up(nlm_init->net);
         if (status < 0)
                 return ERR_PTR(status);
 
@@ -65,7 +65,7 @@ struct nlm_host *nlmclnt_init(const struct nlmclnt_initdata *nlm_init)
                                    nlm_init->hostname, nlm_init->noresvport,
                                    nlm_init->net);
         if (host == NULL) {
-                lockd_down();
+                lockd_down(nlm_init->net);
                 return ERR_PTR(-ENOLCK);
         }
 
@@ -80,8 +80,10 @@ EXPORT_SYMBOL_GPL(nlmclnt_init);
  */
 void nlmclnt_done(struct nlm_host *host)
 {
+        struct net *net = host->net;
+
         nlmclnt_release_host(host);
-        lockd_down();
+        lockd_down(net);
 }
 EXPORT_SYMBOL_GPL(nlmclnt_done);
 
@@ -220,11 +222,12 @@ reclaimer(void *ptr)
         struct nlm_wait   *block;
         struct file_lock *fl, *next;
         u32 nsmstate;
+        struct net *net = host->net;
 
         allow_signal(SIGKILL);
 
         down_write(&host->h_rwsem);
-        lockd_up();     /* note: this cannot fail as lockd is already running */
+        lockd_up(net);  /* note: this cannot fail as lockd is already running */
 
         dprintk("lockd: reclaiming locks for host %s\n", host->h_name);
 
@@ -275,6 +278,6 @@ restart:
 
         /* Release host handle after use */
         nlmclnt_release_host(host);
-        lockd_down();
+        lockd_down(net);
         return 0;
 }
diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c
index f49b9afc4436..1ead0750cdbb 100644
--- a/fs/lockd/svc.c
+++ b/fs/lockd/svc.c
@@ -295,11 +295,10 @@ static void lockd_down_net(struct net *net)
 /*
  * Bring up the lockd process if it's not already up.
  */
-int lockd_up(void)
+int lockd_up(struct net *net)
 {
         struct svc_serv *serv;
         int             error = 0;
-        struct net *net = current->nsproxy->net_ns;
 
         mutex_lock(&nlmsvc_mutex);
         /*
@@ -378,12 +377,12 @@ EXPORT_SYMBOL_GPL(lockd_up);
  * Decrement the user count and bring down lockd if we're the last.
  */
 void
-lockd_down(void)
+lockd_down(struct net *net)
 {
         mutex_lock(&nlmsvc_mutex);
         if (nlmsvc_users) {
                 if (--nlmsvc_users) {
-                        lockd_down_net(current->nsproxy->net_ns);
+                        lockd_down_net(net);
                         goto out;
                 }
         } else {
diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
index 28dfad39f0c5..78e521392df1 100644
--- a/fs/nfsd/nfssvc.c
+++ b/fs/nfsd/nfssvc.c
@@ -220,7 +220,7 @@ static int nfsd_startup(unsigned short port, int nrservs)
         ret = nfsd_init_socks(port);
         if (ret)
                 goto out_racache;
-        ret = lockd_up();
+        ret = lockd_up(&init_net);
         if (ret)
                 goto out_racache;
         ret = nfs4_state_start();
@@ -229,7 +229,7 @@ static int nfsd_startup(unsigned short port, int nrservs)
         nfsd_up = true;
         return 0;
 out_lockd:
-        lockd_down();
+        lockd_down(&init_net);
 out_racache:
         nfsd_racache_shutdown();
         return ret;
@@ -246,7 +246,7 @@ static void nfsd_shutdown(void)
         if (!nfsd_up)
                 return;
         nfs4_state_shutdown();
-        lockd_down();
+        lockd_down(&init_net);
         nfsd_racache_shutdown();
         nfsd_up = false;
 }
diff --git a/include/linux/lockd/bind.h b/include/linux/lockd/bind.h
index 11a966e5f829..4d24d64578c4 100644
--- a/include/linux/lockd/bind.h
+++ b/include/linux/lockd/bind.h
@@ -54,7 +54,7 @@ extern void	nlmclnt_done(struct nlm_host *host);
 
 extern int      nlmclnt_proc(struct nlm_host *host, int cmd,
                                         struct file_lock *fl);
-extern int      lockd_up(void);
-extern void     lockd_down(void);
+extern int      lockd_up(struct net *net);
+extern void     lockd_down(struct net *net);
 
 #endif /* LINUX_LOCKD_BIND_H */