NFSv4.x: Switch to using svc_set_num_threads() to manage the callback threads

This will allow us to bump the number of callback threads at will.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

diff --git a/fs/nfs/callback.c b/fs/nfs/callback.c
index b125f02ddf8bbade22d762d88855682ce84261fb..b91c49f4670ba4389ac98d93396456a2d99c3fca 100644 (file)
--- a/fs/nfs/callback.c
+++ b/fs/nfs/callback.c
@@ -31,8 +31,6 @@
 struct nfs_callback_data {
        unsigned int users;
        struct svc_serv *serv;
-       struct svc_rqst *rqst;
-       struct task_struct *task;
 };
 
 static struct nfs_callback_data nfs_callback_info[NFS4_MAX_MINOR_VERSION + 1];
@@ -89,15 +87,6 @@ nfs4_callback_svc(void *vrqstp)
        return 0;
 }
 
-/*
- * Prepare to bring up the NFSv4 callback service
- */
-static struct svc_rqst *
-nfs4_callback_up(struct svc_serv *serv)
-{
-       return svc_prepare_thread(serv, &serv->sv_pools[0], NUMA_NO_NODE);
-}
-
 #if defined(CONFIG_NFS_V4_1)
 /*
  * The callback service for NFSv4.1 callbacks
@@ -139,19 +128,6 @@ nfs41_callback_svc(void *vrqstp)
        return 0;
 }
 
-/*
- * Bring up the NFSv4.1 callback service
- */
-static struct svc_rqst *
-nfs41_callback_up(struct svc_serv *serv)
-{
-       struct svc_rqst *rqstp;
-
-       rqstp = svc_prepare_thread(serv, &serv->sv_pools[0], NUMA_NO_NODE);
-       dprintk("--> %s return %d\n", __func__, PTR_ERR_OR_ZERO(rqstp));
-       return rqstp;
-}
-
 static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
                struct svc_serv *serv)
 {
@@ -163,12 +139,6 @@ static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
                xprt->bc_serv = serv;
 }
 #else
-static struct svc_rqst *
-nfs41_callback_up(struct svc_serv *serv)
-{
-       return ERR_PTR(-ENOTSUPP);
-}
-
 static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
                struct svc_serv *serv)
 {
@@ -178,42 +148,19 @@ static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
 static int nfs_callback_start_svc(int minorversion, struct rpc_xprt *xprt,
                                  struct svc_serv *serv)
 {
-       struct svc_rqst *rqstp;
-       struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
+       const int nrservs = NFS4_NR_CALLBACK_THREADS;
        int ret;
 
        nfs_callback_bc_serv(minorversion, xprt, serv);
 
-       if (cb_info->task)
+       if (serv->sv_nrthreads-1 == nrservs)
                return 0;
 
-       switch (minorversion) {
-       case 0:
-               /* v4.0 callback setup */
-               rqstp = nfs4_callback_up(serv);
-               break;
-       default:
-               rqstp = nfs41_callback_up(serv);
-       }
-
-       if (IS_ERR(rqstp))
-               return PTR_ERR(rqstp);
-
-       svc_sock_update_bufs(serv);
-
-       cb_info->rqst = rqstp;
-       cb_info->task = kthread_create(serv->sv_ops->svo_function,
-                                   cb_info->rqst,
-                                   "nfsv4.%u-svc", minorversion);
-       if (IS_ERR(cb_info->task)) {
-               ret = PTR_ERR(cb_info->task);
-               svc_exit_thread(cb_info->rqst);
-               cb_info->rqst = NULL;
-               cb_info->task = NULL;
+       ret = serv->sv_ops->svo_setup(serv, NULL, nrservs);
+       if (ret) {
+               serv->sv_ops->svo_setup(serv, NULL, 0);
                return ret;
        }
-       rqstp->rq_task = cb_info->task;
-       wake_up_process(cb_info->task);
        dprintk("nfs_callback_up: service started\n");
        return 0;
 }
@@ -270,12 +217,14 @@ err_bind:
 static struct svc_serv_ops nfs40_cb_sv_ops = {
        .svo_function           = nfs4_callback_svc,
        .svo_enqueue_xprt       = svc_xprt_do_enqueue,
+       .svo_setup              = svc_set_num_threads,
        .svo_module             = THIS_MODULE,
 };
 #if defined(CONFIG_NFS_V4_1)
 static struct svc_serv_ops nfs41_cb_sv_ops = {
        .svo_function           = nfs41_callback_svc,
        .svo_enqueue_xprt       = svc_xprt_do_enqueue,
+       .svo_setup              = svc_set_num_threads,
        .svo_module             = THIS_MODULE,
 };
 
@@ -394,20 +343,18 @@ err_start:
 void nfs_callback_down(int minorversion, struct net *net)
 {
        struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
+       struct svc_serv *serv;
 
        mutex_lock(&nfs_callback_mutex);
-       nfs_callback_down_net(minorversion, cb_info->serv, net);
+       serv = cb_info->serv;
+       nfs_callback_down_net(minorversion, serv, net);
        cb_info->users--;
        if (cb_info->users == 0) {
-               if (cb_info->task != NULL) {
-                       kthread_stop(cb_info->task);
-                       dprintk("nfs_callback_down: service stopped\n");
-               }
-               svc_exit_thread(cb_info->rqst);
+               svc_get(serv);
+               serv->sv_ops->svo_setup(serv, NULL, 0);
+               svc_destroy(serv);
                dprintk("nfs_callback_down: service destroyed\n");
                cb_info->serv = NULL;
-               cb_info->rqst = NULL;
-               cb_info->task = NULL;
        }
        mutex_unlock(&nfs_callback_mutex);
 }

diff --git a/fs/nfs/callback.h b/fs/nfs/callback.h
index 5fe1cecbf9f033ce0603639e771c1d82520599b0..14bd863495db00cc5ed689912c044f557e64ba3c 100644 (file)
--- a/fs/nfs/callback.h
+++ b/fs/nfs/callback.h
@@ -198,6 +198,8 @@ extern void nfs_callback_down(int minorversion, struct net *net);
 #define NFS41_BC_MIN_CALLBACKS 1
 #define NFS41_BC_MAX_CALLBACKS 1
 
+#define NFS4_NR_CALLBACK_THREADS 1
+
 extern unsigned int nfs_callback_set_tcpport;
 
 #endif /* __LINUX_FS_NFS_CALLBACK_H */