NFSv4.x: Fix up the global tracking of the callback server

Ensure that the nfs_callback_info[] array correctly tracks the
struct svc_serv.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

1 files changed, 9 insertions, 5 deletions

diff --git a/fs/nfs/callback.c b/fs/nfs/callback.c
index 08e16f9b3333..b125f02ddf8b 100644
--- a/fs/nfs/callback.c
+++ b/fs/nfs/callback.c
@@ -201,7 +201,6 @@ static int nfs_callback_start_svc(int minorversion, struct rpc_xprt *xprt,
 
         svc_sock_update_bufs(serv);
 
-        cb_info->serv = serv;
         cb_info->rqst = rqstp;
         cb_info->task = kthread_create(serv->sv_ops->svo_function,
                                     cb_info->rqst,
@@ -300,7 +299,7 @@ static struct svc_serv *nfs_callback_create_svc(int minorversion)
         /*
          * Check whether we're already up and running.
          */
-        if (cb_info->task) {
+        if (cb_info->serv) {
                 /*
                  * Note: increase service usage, because later in case of error
                  * svc_destroy() will be called.
@@ -333,6 +332,7 @@ static struct svc_serv *nfs_callback_create_svc(int minorversion)
                 printk(KERN_ERR "nfs_callback_create_svc: create service failed\n");
                 return ERR_PTR(-ENOMEM);
         }
+        cb_info->serv = serv;
         /* As there is only one thread we need to over-ride the
          * default maximum of 80 connections
          */
@@ -375,6 +375,8 @@ int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
          * thread exits.
          */
 err_net:
+        if (!cb_info->users)
+                cb_info->serv = NULL;
         svc_destroy(serv);
 err_create:
         mutex_unlock(&nfs_callback_mutex);
@@ -396,9 +398,11 @@ void nfs_callback_down(int minorversion, struct net *net)
         mutex_lock(&nfs_callback_mutex);
         nfs_callback_down_net(minorversion, cb_info->serv, net);
         cb_info->users--;
-        if (cb_info->users == 0 && cb_info->task != NULL) {
-                kthread_stop(cb_info->task);
-                dprintk("nfs_callback_down: service stopped\n");
+        if (cb_info->users == 0) {
+                if (cb_info->task != NULL) {
+                        kthread_stop(cb_info->task);
+                        dprintk("nfs_callback_down: service stopped\n");
+                }
                 svc_exit_thread(cb_info->rqst);
                 dprintk("nfs_callback_down: service destroyed\n");
                 cb_info->serv = NULL;