1 files changed, 108 insertions, 4 deletions

diff --git a/fs/nfs/callback.c b/fs/nfs/callback.c
index 4b1313eda6f5..470928898063 100644
--- a/fs/nfs/callback.c
+++ b/fs/nfs/callback.c
@@ -17,6 +17,9 @@
 #include <linux/freezer.h>
 #include <linux/kthread.h>
 #include <linux/sunrpc/svcauth_gss.h>
+#if defined(CONFIG_NFS_V4_1)
+#include <linux/sunrpc/bc_xprt.h>
+#endif
 
 #include <net/inet_sock.h>
 
@@ -28,6 +31,7 @@
 
 struct nfs_callback_data {
         unsigned int users;
+        struct svc_serv *serv;
         struct svc_rqst *rqst;
         struct task_struct *task;
 };
@@ -131,6 +135,99 @@ out_err:
         return ERR_PTR(ret);
 }
 
+#if defined(CONFIG_NFS_V4_1)
+/*
+ * The callback service for NFSv4.1 callbacks
+ */
+static int
+nfs41_callback_svc(void *vrqstp)
+{
+        struct svc_rqst *rqstp = vrqstp;
+        struct svc_serv *serv = rqstp->rq_server;
+        struct rpc_rqst *req;
+        int error;
+        DEFINE_WAIT(wq);
+
+        set_freezable();
+
+        /*
+         * FIXME: do we really need to run this under the BKL? If so, please
+         * add a comment about what it's intended to protect.
+         */
+        lock_kernel();
+        while (!kthread_should_stop()) {
+                prepare_to_wait(&serv->sv_cb_waitq, &wq, TASK_INTERRUPTIBLE);
+                spin_lock_bh(&serv->sv_cb_lock);
+                if (!list_empty(&serv->sv_cb_list)) {
+                        req = list_first_entry(&serv->sv_cb_list,
+                                        struct rpc_rqst, rq_bc_list);
+                        list_del(&req->rq_bc_list);
+                        spin_unlock_bh(&serv->sv_cb_lock);
+                        dprintk("Invoking bc_svc_process()\n");
+                        error = bc_svc_process(serv, req, rqstp);
+                        dprintk("bc_svc_process() returned w/ error code= %d\n",
+                                error);
+                } else {
+                        spin_unlock_bh(&serv->sv_cb_lock);
+                        schedule();
+                }
+                finish_wait(&serv->sv_cb_waitq, &wq);
+        }
+        unlock_kernel();
+        nfs_callback_info.task = NULL;
+        svc_exit_thread(rqstp);
+        return 0;
+}
+
+/*
+ * Bring up the NFSv4.1 callback service
+ */
+struct svc_rqst *
+nfs41_callback_up(struct svc_serv *serv, struct rpc_xprt *xprt)
+{
+        /*
+         * Save the svc_serv in the transport so that it can
+         * be referenced when the session backchannel is initialized
+         */
+        xprt->bc_serv = serv;
+
+        INIT_LIST_HEAD(&serv->sv_cb_list);
+        spin_lock_init(&serv->sv_cb_lock);
+        init_waitqueue_head(&serv->sv_cb_waitq);
+        return svc_prepare_thread(serv, &serv->sv_pools[0]);
+}
+
+static inline int nfs_minorversion_callback_svc_setup(u32 minorversion,
+                struct svc_serv *serv, struct rpc_xprt *xprt,
+                struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp))
+{
+        if (minorversion) {
+                *rqstpp = nfs41_callback_up(serv, xprt);
+                *callback_svc = nfs41_callback_svc;
+        }
+        return minorversion;
+}
+
+static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
+                struct nfs_callback_data *cb_info)
+{
+        if (minorversion)
+                xprt->bc_serv = cb_info->serv;
+}
+#else
+static inline int nfs_minorversion_callback_svc_setup(u32 minorversion,
+                struct svc_serv *serv, struct rpc_xprt *xprt,
+                struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp))
+{
+        return 0;
+}
+
+static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
+                struct nfs_callback_data *cb_info)
+{
+}
+#endif /* CONFIG_NFS_V4_1 */
+
 /*
  * Bring up the callback thread if it is not already up.
  */
@@ -141,21 +238,25 @@ int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
         int (*callback_svc)(void *vrqstp);
         char svc_name[12];
         int ret = 0;
+        int minorversion_setup;
 
         mutex_lock(&nfs_callback_mutex);
-        if (nfs_callback_info.users++ || nfs_callback_info.task != NULL)
+        if (nfs_callback_info.users++ || nfs_callback_info.task != NULL) {
+                nfs_callback_bc_serv(minorversion, xprt, &nfs_callback_info);
                 goto out;
+        }
         serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, NULL);
         if (!serv) {
                 ret = -ENOMEM;
                 goto out_err;
         }
 
-        if (!minorversion) {
+        minorversion_setup =  nfs_minorversion_callback_svc_setup(minorversion,
+                                        serv, xprt, &rqstp, &callback_svc);
+        if (!minorversion_setup) {
+                /* v4.0 callback setup */
                 rqstp = nfs4_callback_up(serv);
                 callback_svc = nfs4_callback_svc;
-        } else {
-                BUG();  /* for now */
         }
 
         if (IS_ERR(rqstp)) {
@@ -166,6 +267,7 @@ int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
         svc_sock_update_bufs(serv);
 
         sprintf(svc_name, "nfsv4.%u-svc", minorversion);
+        nfs_callback_info.serv = serv;
         nfs_callback_info.rqst = rqstp;
         nfs_callback_info.task = kthread_run(callback_svc,
                                              nfs_callback_info.rqst,
@@ -173,6 +275,7 @@ int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
         if (IS_ERR(nfs_callback_info.task)) {
                 ret = PTR_ERR(nfs_callback_info.task);
                 svc_exit_thread(nfs_callback_info.rqst);
+                nfs_callback_info.serv = NULL;
                 nfs_callback_info.rqst = NULL;
                 nfs_callback_info.task = NULL;
                 goto out_err;
@@ -205,6 +308,7 @@ void nfs_callback_down(void)
         if (nfs_callback_info.users == 0 && nfs_callback_info.task != NULL) {
                 kthread_stop(nfs_callback_info.task);
                 svc_exit_thread(nfs_callback_info.rqst);
+                nfs_callback_info.serv = NULL;
                 nfs_callback_info.rqst = NULL;
                 nfs_callback_info.task = NULL;
         }