nfsd: move callback rpc_client creation into separate thread

The whole reason to move this callback-channel probe into a separate
thread was because (for now) we don't have an easy way to create the
rpc_client asynchronously.  But I forgot to move the rpc_create() to the
spawned thread.  Doh!  Fix that.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
index a9735a6..6eb5cd2 100644 (file)
--- a/fs/nfsd/nfs4callback.c
+++ b/fs/nfsd/nfs4callback.c
@@ -350,30 +350,6 @@ static struct rpc_version *        nfs_cb_version[] = {
 static int do_probe_callback(void *data)
 {
        struct nfs4_client *clp = data;
-       struct nfs4_callback *cb = &clp->cl_callback;
-       struct rpc_message msg = {
-               .rpc_proc       = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_NULL],
-               .rpc_argp       = clp,
-       };
-       int status;
-
-       status = rpc_call_sync(cb->cb_client, &msg, RPC_TASK_SOFT);
-
-       if (status) {
-               rpc_shutdown_client(cb->cb_client);
-               cb->cb_client = NULL;
-       } else
-               atomic_set(&cb->cb_set, 1);
-       put_nfs4_client(clp);
-       return 0;
-}
-
-/*
- * Set up the callback client and put a NFSPROC4_CB_NULL on the wire...
- */
-void
-nfsd4_probe_callback(struct nfs4_client *clp)
-{
        struct sockaddr_in      addr;
        struct nfs4_callback    *cb = &clp->cl_callback;
        struct rpc_timeout      timeparms = {
@@ -390,12 +366,15 @@ nfsd4_probe_callback(struct nfs4_client *clp)
                .timeout        = &timeparms,
                .program        = program,
                .version        = nfs_cb_version[1]->number,
-               .authflavor     = RPC_AUTH_UNIX,        /* XXX: need AUTH_GSS... */
+               .authflavor     = RPC_AUTH_UNIX, /* XXX: need AUTH_GSS... */
                .flags          = (RPC_CLNT_CREATE_NOPING),
        };
-       struct task_struct *t;
-
-       BUG_ON(atomic_read(&clp->cl_callback.cb_set));
+       struct rpc_message msg = {
+               .rpc_proc       = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_NULL],
+               .rpc_argp       = clp,
+       };
+       struct rpc_clnt *client;
+       int status;
 
        /* Initialize address */
        memset(&addr, 0, sizeof(addr));
@@ -415,29 +394,50 @@ nfsd4_probe_callback(struct nfs4_client *clp)
        program->stats->program = program;
 
        /* Create RPC client */
-       cb->cb_client = rpc_create(&args);
-       if (IS_ERR(cb->cb_client)) {
+       client = rpc_create(&args);
+       if (IS_ERR(client)) {
                dprintk("NFSD: couldn't create callback client\n");
+               status = PTR_ERR(client);
                goto out_err;
        }
 
+       status = rpc_call_sync(client, &msg, RPC_TASK_SOFT);
+
+       if (status)
+               goto out_release_client;
+
+       cb->cb_client = client;
+       atomic_set(&cb->cb_set, 1);
+       put_nfs4_client(clp);
+       return 0;
+out_release_client:
+       rpc_shutdown_client(client);
+out_err:
+       put_nfs4_client(clp);
+       dprintk("NFSD: warning: no callback path to client %.*s\n",
+               (int)clp->cl_name.len, clp->cl_name.data);
+       return status;
+}
+
+/*
+ * Set up the callback client and put a NFSPROC4_CB_NULL on the wire...
+ */
+void
+nfsd4_probe_callback(struct nfs4_client *clp)
+{
+       struct task_struct *t;
+
+       BUG_ON(atomic_read(&clp->cl_callback.cb_set));
+
        /* the task holds a reference to the nfs4_client struct */
        atomic_inc(&clp->cl_count);
 
        t = kthread_run(do_probe_callback, clp, "nfs4_cb_probe");
 
        if (IS_ERR(t))
-               goto out_release_clp;
+               atomic_dec(&clp->cl_count);
 
        return;
-
-out_release_clp:
-       atomic_dec(&clp->cl_count);
-       rpc_shutdown_client(cb->cb_client);
-out_err:
-       cb->cb_client = NULL;
-       dprintk("NFSD: warning: no callback path to client %.*s\n",
-               (int)clp->cl_name.len, clp->cl_name.data);
 }
 
 /*