3 files changed, 73 insertions, 20 deletions

diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
index 91eb2ea9ef0a..e078c747f49d 100644
--- a/fs/nfsd/nfs4callback.c
+++ b/fs/nfsd/nfs4callback.c
@@ -32,6 +32,7 @@
  */
 
 #include <linux/sunrpc/clnt.h>
+#include <linux/sunrpc/svc_xprt.h>
 #include "nfsd.h"
 #include "state.h"
 
@@ -692,11 +693,41 @@ static const struct rpc_call_ops nfsd4_cb_recall_ops = {
         .rpc_release = nfsd4_cb_recall_release,
 };
 
+static struct workqueue_struct *callback_wq;
+
+int nfsd4_create_callback_queue(void)
+{
+        callback_wq = create_singlethread_workqueue("nfsd4_callbacks");
+        if (!callback_wq)
+                return -ENOMEM;
+        return 0;
+}
+
+void nfsd4_destroy_callback_queue(void)
+{
+        destroy_workqueue(callback_wq);
+}
+
+void nfsd4_set_callback_client(struct nfs4_client *clp, struct rpc_clnt
+*new)
+{
+        struct rpc_clnt *old = clp->cl_cb_conn.cb_client;
+
+        clp->cl_cb_conn.cb_client = new;
+        /*
+         * After this, any work that saw the old value of cb_client will
+         * be gone:
+         */
+        flush_workqueue(callback_wq);
+        /* So we can safely shut it down: */
+        if (old)
+                rpc_shutdown_client(old);
+}
+
 /*
  * called with dp->dl_count inc'ed.
  */
-void
-nfsd4_cb_recall(struct nfs4_delegation *dp)
+static void _nfsd4_cb_recall(struct nfs4_delegation *dp)
 {
         struct nfs4_client *clp = dp->dl_client;
         struct rpc_clnt *clnt = clp->cl_cb_conn.cb_client;
@@ -707,6 +738,9 @@ nfsd4_cb_recall(struct nfs4_delegation *dp)
         };
         int status;
 
+        if (clnt == NULL)
+                return; /* Client is shutting down; give up. */
+
         args->args_op = dp;
         msg.rpc_argp = args;
         dp->dl_retries = 1;
@@ -717,3 +751,19 @@ nfsd4_cb_recall(struct nfs4_delegation *dp)
                 nfs4_put_delegation(dp);
         }
 }
+
+void nfsd4_do_callback_rpc(struct work_struct *w)
+{
+        /* XXX: for now, just send off delegation recall. */
+        /* In future, generalize to handle any sort of callback. */
+        struct nfsd4_callback *c = container_of(w, struct nfsd4_callback, cb_work);
+        struct nfs4_delegation *dp = container_of(c, struct nfs4_delegation, dl_recall);
+
+        _nfsd4_cb_recall(dp);
+}
+
+
+void nfsd4_cb_recall(struct nfs4_delegation *dp)
+{
+        queue_work(callback_wq, &dp->dl_recall.cb_work);
+}
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 5051ade30dfb..adc51d10d435 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -198,6 +198,7 @@ alloc_init_deleg(struct nfs4_client *clp, struct nfs4_stateid *stp, struct svc_f
         atomic_set(&dp->dl_count, 1);
         list_add(&dp->dl_perfile, &fp->fi_delegations);
         list_add(&dp->dl_perclnt, &clp->cl_delegations);
+        INIT_WORK(&dp->dl_recall.cb_work, nfsd4_do_callback_rpc);
         return dp;
 }
 
@@ -679,21 +680,6 @@ static struct nfs4_client *alloc_client(struct xdr_netobj name)
         return clp;
 }
 
-static void
-shutdown_callback_client(struct nfs4_client *clp)
-{
-        struct rpc_clnt *clnt = clp->cl_cb_conn.cb_client;
-
-        if (clnt) {
-                /*
-                 * Callback threads take a reference on the client, so there
-                 * should be no outstanding callbacks at this point.
-                 */
-                clp->cl_cb_conn.cb_client = NULL;
-                rpc_shutdown_client(clnt);
-        }
-}
-
 static inline void
 free_client(struct nfs4_client *clp)
 {
@@ -746,7 +732,7 @@ expire_client(struct nfs4_client *clp)
                                  se_perclnt);
                 release_session(ses);
         }
-        shutdown_callback_client(clp);
+        nfsd4_set_callback_client(clp, NULL);
         if (clp->cl_cb_xprt)
                 svc_xprt_put(clp->cl_cb_xprt);
         put_nfs4_client(clp);
@@ -1392,7 +1378,7 @@ nfsd4_destroy_session(struct svc_rqst *r,
         spin_unlock(&sessionid_lock);
 
         /* wait for callbacks */
-        shutdown_callback_client(ses->se_client);
+        nfsd4_set_callback_client(ses->se_client, NULL);
         nfsd4_put_session(ses);
         status = nfs_ok;
 out:
@@ -4004,16 +3990,27 @@ set_max_delegations(void)
 static int
 __nfs4_state_start(void)
 {
+        int ret;
+
         boot_time = get_seconds();
         locks_start_grace(&nfsd4_manager);
         printk(KERN_INFO "NFSD: starting %ld-second grace period\n",
                nfsd4_grace);
+        ret = set_callback_cred();
+        if (ret)
+                return -ENOMEM;
         laundry_wq = create_singlethread_workqueue("nfsd4");
         if (laundry_wq == NULL)
                 return -ENOMEM;
+        ret = nfsd4_create_callback_queue();
+        if (ret)
+                goto out_free_laundry;
         queue_delayed_work(laundry_wq, &laundromat_work, nfsd4_grace * HZ);
         set_max_delegations();
-        return set_callback_cred();
+        return 0;
+out_free_laundry:
+        destroy_workqueue(laundry_wq);
+        return ret;
 }
 
 int
@@ -4075,6 +4072,7 @@ nfs4_state_shutdown(void)
         nfs4_lock_state();
         nfs4_release_reclaim();
         __nfs4_state_shutdown();
+        nfsd4_destroy_callback_queue();
         nfs4_unlock_state();
 }
 
diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
index b85437982a8d..c4c92aea8f39 100644
--- a/fs/nfsd/state.h
+++ b/fs/nfsd/state.h
@@ -77,6 +77,7 @@ struct nfs4_rpc_args {
 
 struct nfsd4_callback {
         struct nfs4_rpc_args cb_args;
+        struct work_struct cb_work;
 };
 
 struct nfs4_delegation {
@@ -391,7 +392,11 @@ extern void put_nfs4_client(struct nfs4_client *clp);
 extern void nfs4_free_stateowner(struct kref *kref);
 extern int set_callback_cred(void);
 extern void nfsd4_probe_callback(struct nfs4_client *clp);
+extern void nfsd4_do_callback_rpc(struct work_struct *);
 extern void nfsd4_cb_recall(struct nfs4_delegation *dp);
+extern int nfsd4_create_callback_queue(void);
+extern void nfsd4_destroy_callback_queue(void);
+extern void nfsd4_set_callback_client(struct nfs4_client *, struct rpc_clnt *);
 extern void nfs4_put_delegation(struct nfs4_delegation *dp);
 extern __be32 nfs4_make_rec_clidname(char *clidname, struct xdr_netobj *clname);
 extern void nfsd4_init_recdir(char *recdir_name);