nfs41: minorversion support for nfs4_{init,destroy}_callback

move nfs4_init_callback into nfs4_init_client_minor_version
and nfs4_destroy_callback into nfs4_clear_client_minor_version

as these need to happen also when auto-negotiating the minorversion
once the callback service for nfs41 becomes different than for nfs4.0

Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfs41: Fix checkpatch warning]
Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[Type check arguments of nfs_callback_up]
Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfs41: Backchannel: Remove FIXME comment]
Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>

3 files changed, 54 insertions, 34 deletions

diff --git a/fs/nfs/callback.c b/fs/nfs/callback.c
index a886e692ddd0..4b1313eda6f5 100644
--- a/fs/nfs/callback.c
+++ b/fs/nfs/callback.c
@@ -59,7 +59,7 @@ module_param_call(callback_tcpport, param_set_port, param_get_int,
  * This is the callback kernel thread.
  */
 static int
-nfs_callback_svc(void *vrqstp)
+nfs4_callback_svc(void *vrqstp)
 {
         int err, preverr = 0;
         struct svc_rqst *rqstp = vrqstp;
@@ -97,20 +97,12 @@ nfs_callback_svc(void *vrqstp)
 }
 
 /*
- * Bring up the callback thread if it is not already up.
+ * Prepare to bring up the NFSv4 callback service
  */
-int nfs_callback_up(void)
+struct svc_rqst *
+nfs4_callback_up(struct svc_serv *serv)
 {
-        struct svc_serv *serv = NULL;
-        int ret = 0;
-
-        mutex_lock(&nfs_callback_mutex);
-        if (nfs_callback_info.users++ || nfs_callback_info.task != NULL)
-                goto out;
-        serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, NULL);
-        ret = -ENOMEM;
-        if (!serv)
-                goto out_err;
+        int ret;
 
         ret = svc_create_xprt(serv, "tcp", PF_INET,
                                 nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
@@ -131,18 +123,53 @@ int nfs_callback_up(void)
                 goto out_err;
 #endif  /* defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) */
 
-        nfs_callback_info.rqst = svc_prepare_thread(serv, &serv->sv_pools[0]);
-        if (IS_ERR(nfs_callback_info.rqst)) {
-                ret = PTR_ERR(nfs_callback_info.rqst);
-                nfs_callback_info.rqst = NULL;
+        return svc_prepare_thread(serv, &serv->sv_pools[0]);
+
+out_err:
+        if (ret == 0)
+                ret = -ENOMEM;
+        return ERR_PTR(ret);
+}
+
+/*
+ * 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_rqst *rqstp;
+        int (*callback_svc)(void *vrqstp);
+        char svc_name[12];
+        int ret = 0;
+
+        mutex_lock(&nfs_callback_mutex);
+        if (nfs_callback_info.users++ || nfs_callback_info.task != NULL)
+                goto out;
+        serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, NULL);
+        if (!serv) {
+                ret = -ENOMEM;
+                goto out_err;
+        }
+
+        if (!minorversion) {
+                rqstp = nfs4_callback_up(serv);
+                callback_svc = nfs4_callback_svc;
+        } else {
+                BUG();  /* for now */
+        }
+
+        if (IS_ERR(rqstp)) {
+                ret = PTR_ERR(rqstp);
                 goto out_err;
         }
 
         svc_sock_update_bufs(serv);
 
-        nfs_callback_info.task = kthread_run(nfs_callback_svc,
+        sprintf(svc_name, "nfsv4.%u-svc", minorversion);
+        nfs_callback_info.rqst = rqstp;
+        nfs_callback_info.task = kthread_run(callback_svc,
                                              nfs_callback_info.rqst,
-                                             "nfsv4-svc");
+                                             svc_name);
         if (IS_ERR(nfs_callback_info.task)) {
                 ret = PTR_ERR(nfs_callback_info.task);
                 svc_exit_thread(nfs_callback_info.rqst);
diff --git a/fs/nfs/callback.h b/fs/nfs/callback.h
index e110e286a262..9b907f408b8d 100644
--- a/fs/nfs/callback.h
+++ b/fs/nfs/callback.h
@@ -63,7 +63,7 @@ extern __be32 nfs4_callback_getattr(struct cb_getattrargs *args, struct cb_getat
 extern __be32 nfs4_callback_recall(struct cb_recallargs *args, void *dummy);
 
 #ifdef CONFIG_NFS_V4
-extern int nfs_callback_up(void);
+extern int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt);
 extern void nfs_callback_down(void);
 #else
 #define nfs_callback_up()       (0)
diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index d9657d455730..df2b40d1883d 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -47,9 +47,6 @@
 #include "internal.h"
 #include "fscache.h"
 
-static int nfs4_init_callback(struct nfs_client *);
-static void nfs4_destroy_callback(struct nfs_client *);
-
 #define NFSDBG_FACILITY         NFSDBG_CLIENT
 
 static DEFINE_SPINLOCK(nfs_client_lock);
@@ -124,9 +121,6 @@ static struct nfs_client *nfs_alloc_client(const struct nfs_client_initdata *cl_
 
         clp->rpc_ops = cl_init->rpc_ops;
 
-        if (nfs4_init_callback(clp) < 0)
-                goto error_2;
-
         atomic_set(&clp->cl_count, 1);
         clp->cl_cons_state = NFS_CS_INITING;
 
@@ -136,7 +130,7 @@ static struct nfs_client *nfs_alloc_client(const struct nfs_client_initdata *cl_
         if (cl_init->hostname) {
                 clp->cl_hostname = kstrdup(cl_init->hostname, GFP_KERNEL);
                 if (!clp->cl_hostname)
-                        goto error_3;
+                        goto error_cleanup;
         }
 
         INIT_LIST_HEAD(&clp->cl_superblocks);
@@ -161,9 +155,7 @@ static struct nfs_client *nfs_alloc_client(const struct nfs_client_initdata *cl_
 
         return clp;
 
-error_3:
-        nfs4_destroy_callback(clp);
-error_2:
+error_cleanup:
         kfree(clp);
 error_0:
         return NULL;
@@ -207,6 +199,8 @@ static void nfs4_clear_client_minor_version(struct nfs_client *clp)
 
         clp->cl_call_sync = _nfs4_call_sync;
 #endif /* CONFIG_NFS_V4_1 */
+
+        nfs4_destroy_callback(clp);
 }
 
 /*
@@ -225,8 +219,6 @@ static void nfs_free_client(struct nfs_client *clp)
         if (!IS_ERR(clp->cl_rpcclient))
                 rpc_shutdown_client(clp->cl_rpcclient);
 
-        nfs4_destroy_callback(clp);
-
         if (clp->cl_machine_cred != NULL)
                 put_rpccred(clp->cl_machine_cred);
 
@@ -1104,7 +1096,8 @@ static int nfs4_init_callback(struct nfs_client *clp)
         int error;
 
         if (clp->rpc_ops->version == 4) {
-                error = nfs_callback_up();
+                error = nfs_callback_up(clp->cl_minorversion,
+                                        clp->cl_rpcclient->cl_xprt);
                 if (error < 0) {
                         dprintk("%s: failed to start callback. Error = %d\n",
                                 __func__, error);
@@ -1139,7 +1132,7 @@ static int nfs4_init_client_minor_version(struct nfs_client *clp)
         }
 #endif /* CONFIG_NFS_V4_1 */
 
-        return 0;
+        return nfs4_init_callback(clp);
 }
 
 /*