sunrpc: replace sunrpc_net->gssd_running flag with a more reliable check

Now that we have a more reliable method to tell if gssd is running, we
can replace the sn->gssd_running flag with a function that will query to
see if it's up and running.

There's also no need to attempt an upcall that we know will fail, so
just return -EACCES if gssd isn't running. Finally, fix the warn_gss()
message not to claim that that the upcall timed out since we don't
necesarily perform one now when gssd isn't running, and remove the
extraneous newline from the message.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

4 files changed, 19 insertions, 16 deletions

diff --git a/include/linux/sunrpc/rpc_pipe_fs.h b/include/linux/sunrpc/rpc_pipe_fs.h
index 85f13424647c..7f490bef9e99 100644
--- a/include/linux/sunrpc/rpc_pipe_fs.h
+++ b/include/linux/sunrpc/rpc_pipe_fs.h
@@ -131,5 +131,7 @@ extern int rpc_unlink(struct dentry *);
 extern int register_rpc_pipefs(void);
 extern void unregister_rpc_pipefs(void);
 
+extern bool gssd_running(struct net *net);
+
 #endif
 #endif
diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c
index 42fdfc634e56..0a2aee060f9f 100644
--- a/net/sunrpc/auth_gss/auth_gss.c
+++ b/net/sunrpc/auth_gss/auth_gss.c
@@ -536,8 +536,7 @@ static void warn_gssd(void)
         unsigned long now = jiffies;
 
         if (time_after(now, ratelimit)) {
-                printk(KERN_WARNING "RPC: AUTH_GSS upcall timed out.\n"
-                                "Please check user daemon is running.\n");
+                pr_warn("RPC: AUTH_GSS upcall failed. Please check user daemon is running.\n");
                 ratelimit = now + 15*HZ;
         }
 }
@@ -600,7 +599,6 @@ gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
         struct rpc_pipe *pipe;
         struct rpc_cred *cred = &gss_cred->gc_base;
         struct gss_upcall_msg *gss_msg;
-        unsigned long timeout;
         DEFINE_WAIT(wait);
         int err;
 
@@ -608,17 +606,16 @@ gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
                 __func__, from_kuid(&init_user_ns, cred->cr_uid));
 retry:
         err = 0;
-        /* Default timeout is 15s unless we know that gssd is not running */
-        timeout = 15 * HZ;
-        if (!sn->gssd_running)
-                timeout = HZ >> 2;
+        /* if gssd is down, just skip upcalling altogether */
+        if (!gssd_running(net)) {
+                warn_gssd();
+                return -EACCES;
+        }
         gss_msg = gss_setup_upcall(gss_auth, cred);
         if (PTR_ERR(gss_msg) == -EAGAIN) {
                 err = wait_event_interruptible_timeout(pipe_version_waitqueue,
-                                sn->pipe_version >= 0, timeout);
+                                sn->pipe_version >= 0, 15 * HZ);
                 if (sn->pipe_version < 0) {
-                        if (err == 0)
-                                sn->gssd_running = 0;
                         warn_gssd();
                         err = -EACCES;
                 }
diff --git a/net/sunrpc/netns.h b/net/sunrpc/netns.h
index 8a8e841d1547..94e506f9d72b 100644
--- a/net/sunrpc/netns.h
+++ b/net/sunrpc/netns.h
@@ -33,8 +33,6 @@ struct sunrpc_net {
         int pipe_version;
         atomic_t pipe_users;
         struct proc_dir_entry *use_gssp_proc;
-
-        unsigned int gssd_running;
 };
 
 extern int sunrpc_net_id;
diff --git a/net/sunrpc/rpc_pipe.c b/net/sunrpc/rpc_pipe.c
index c23458b464c4..5cd7ad1225a3 100644
--- a/net/sunrpc/rpc_pipe.c
+++ b/net/sunrpc/rpc_pipe.c
@@ -216,14 +216,11 @@ rpc_destroy_inode(struct inode *inode)
 static int
 rpc_pipe_open(struct inode *inode, struct file *filp)
 {
-        struct net *net = inode->i_sb->s_fs_info;
-        struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
         struct rpc_pipe *pipe;
         int first_open;
         int res = -ENXIO;
 
         mutex_lock(&inode->i_mutex);
-        sn->gssd_running = 1;
         pipe = RPC_I(inode)->pipe;
         if (pipe == NULL)
                 goto out;
@@ -1222,7 +1219,6 @@ int rpc_pipefs_init_net(struct net *net)
                 return PTR_ERR(sn->gssd_dummy);
 
         mutex_init(&sn->pipefs_sb_lock);
-        sn->gssd_running = 1;
         sn->pipe_version = -1;
         return 0;
 }
@@ -1376,6 +1372,16 @@ err_depopulate:
         return err;
 }
 
+bool
+gssd_running(struct net *net)
+{
+        struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
+        struct rpc_pipe *pipe = sn->gssd_dummy;
+
+        return pipe->nreaders || pipe->nwriters;
+}
+EXPORT_SYMBOL_GPL(gssd_running);
+
 static struct dentry *
 rpc_mount(struct file_system_type *fs_type,
                 int flags, const char *dev_name, void *data)