NFS: callback service creation function introduced
authorStanislav Kinsbursky <skinsbursky@parallels.com>
Mon, 20 Aug 2012 14:00:11 +0000 (18:00 +0400)
committerTrond Myklebust <Trond.Myklebust@netapp.com>
Mon, 1 Oct 2012 22:25:11 +0000 (15:25 -0700)
This function creates service if it's not exist, or increase usage counter of
the existent, and returns pointer to it.
Usage counter will be droppepd by svc_destroy() later in nfs_callback_up().

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
fs/nfs/callback.c

index 51297b2d05329003e8e0681ff210c536519e6ba4..18efeb5f005dcaf13b6853e9f62cb17cfcadb19c 100644 (file)
@@ -217,12 +217,50 @@ static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
 }
 #endif /* CONFIG_NFS_V4_1 */
 
+static struct svc_serv *nfs_callback_create_svc(int minorversion)
+{
+       struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
+       struct svc_serv *serv;
+
+       /*
+        * Check whether we're already up and running.
+        */
+       if (cb_info->task) {
+               /*
+                * Note: increase service usage, because later in case of error
+                * svc_destroy() will be called.
+                */
+               svc_get(cb_info->serv);
+               return cb_info->serv;
+       }
+
+       /*
+        * Sanity check: if there's no task,
+        * we should be the first user ...
+        */
+       if (cb_info->users)
+               printk(KERN_WARNING "nfs_callback_create_svc: no kthread, %d users??\n",
+                       cb_info->users);
+
+       serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, NULL);
+       if (!serv) {
+               printk(KERN_ERR "nfs_callback_create_svc: create service failed\n");
+               return ERR_PTR(-ENOMEM);
+       }
+       /* As there is only one thread we need to over-ride the
+        * default maximum of 80 connections
+        */
+       serv->sv_maxconn = 1024;
+       dprintk("nfs_callback_create_svc: service created\n");
+       return serv;
+}
+
 /*
  * Bring up the callback thread if it is not already up.
  */
 int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
 {
-       struct svc_serv *serv = NULL;
+       struct svc_serv *serv;
        struct svc_rqst *rqstp;
        int (*callback_svc)(void *vrqstp);
        struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
@@ -232,19 +270,17 @@ int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
        struct net *net = &init_net;
 
        mutex_lock(&nfs_callback_mutex);
+
+       serv = nfs_callback_create_svc(minorversion);
+       if (IS_ERR(serv)) {
+               ret = PTR_ERR(serv);
+               goto err_create;
+       }
+
        if (cb_info->users++ || cb_info->task != NULL) {
                nfs_callback_bc_serv(minorversion, xprt, cb_info);
                goto out;
        }
-       serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, NULL);
-       if (!serv) {
-               ret = -ENOMEM;
-               goto out_err;
-       }
-       /* As there is only one thread we need to over-ride the
-        * default maximum of 80 connections
-        */
-       serv->sv_maxconn = 1024;
 
        ret = svc_bind(serv, net);
        if (ret < 0) {
@@ -285,16 +321,15 @@ out:
         * on both success and failure so that the refcount is 1 when the
         * thread exits.
         */
-       if (serv)
-               svc_destroy(serv);
+       svc_destroy(serv);
+err_create:
        mutex_unlock(&nfs_callback_mutex);
        return ret;
 out_err:
        dprintk("NFS: Couldn't create callback socket or server thread; "
                "err = %d\n", ret);
        cb_info->users--;
-       if (serv)
-               svc_shutdown_net(serv, net);
+       svc_shutdown_net(serv, net);
        goto out;
 }