fs: nfsd: use group allocation/free of per-cpu counters API

Use group allocation/free of per-cpu counters api to accelerate
nfsd percpu_counters init/destroy(), and also squash the
nfsd_percpu_counters_init/reset/destroy() and nfsd_counters_init/destroy()
into callers to simplify code.

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

fs/nfsd/export.c

@@ -334,21 +334,25 @@ static void nfsd4_fslocs_free(struct nfsd4_fs_locations *fsloc)
 static int export_stats_init(struct export_stats *stats)
 {
 	stats->start_time = ktime_get_seconds();
-	return nfsd_percpu_counters_init(stats->counter, EXP_STATS_COUNTERS_NUM);
+	return percpu_counter_init_many(stats->counter, 0, GFP_KERNEL,
+					EXP_STATS_COUNTERS_NUM);
 }
 
 static void export_stats_reset(struct export_stats *stats)
 {
-	if (stats)
-		nfsd_percpu_counters_reset(stats->counter,
-					   EXP_STATS_COUNTERS_NUM);
+	if (stats) {
+		int i;
+
+		for (i = 0; i < EXP_STATS_COUNTERS_NUM; i++)
+			percpu_counter_set(&stats->counter[i], 0);
+	}
 }
 
 static void export_stats_destroy(struct export_stats *stats)
 {
 	if (stats)
-		nfsd_percpu_counters_destroy(stats->counter,
-					     EXP_STATS_COUNTERS_NUM);
+		percpu_counter_destroy_many(stats->counter,
+					    EXP_STATS_COUNTERS_NUM);
 }
 
 static void svc_export_put(struct kref *ref)

fs/nfsd/nfsctl.c

@@ -1672,7 +1672,8 @@ static __net_init int nfsd_net_init(struct net *net)
 	retval = nfsd_idmap_init(net);
 	if (retval)
 		goto out_idmap_error;
-	retval = nfsd_stat_counters_init(nn);
+	retval = percpu_counter_init_many(nn->counter, 0, GFP_KERNEL,
+					  NFSD_STATS_COUNTERS_NUM);
 	if (retval)
 		goto out_repcache_error;
 	memset(&nn->nfsd_svcstats, 0, sizeof(nn->nfsd_svcstats));
@@ -1704,7 +1705,7 @@ static __net_exit void nfsd_net_exit(struct net *net)
 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 
 	nfsd_proc_stat_shutdown(net);
-	nfsd_stat_counters_destroy(nn);
+	percpu_counter_destroy_many(nn->counter, NFSD_STATS_COUNTERS_NUM);
 	nfsd_idmap_shutdown(net);
 	nfsd_export_shutdown(net);
 	nfsd_netns_free_versions(nn);

fs/nfsd/stats.c

@@ -73,48 +73,6 @@ static int nfsd_show(struct seq_file *seq, void *v)
 
 DEFINE_PROC_SHOW_ATTRIBUTE(nfsd);
 
-int nfsd_percpu_counters_init(struct percpu_counter *counters, int num)
-{
-	int i, err = 0;
-
-	for (i = 0; !err && i < num; i++)
-		err = percpu_counter_init(&counters[i], 0, GFP_KERNEL);
-
-	if (!err)
-		return 0;
-
-	for (; i > 0; i--)
-		percpu_counter_destroy(&counters[i-1]);
-
-	return err;
-}
-
-void nfsd_percpu_counters_reset(struct percpu_counter counters[], int num)
-{
-	int i;
-
-	for (i = 0; i < num; i++)
-		percpu_counter_set(&counters[i], 0);
-}
-
-void nfsd_percpu_counters_destroy(struct percpu_counter counters[], int num)
-{
-	int i;
-
-	for (i = 0; i < num; i++)
-		percpu_counter_destroy(&counters[i]);
-}
-
-int nfsd_stat_counters_init(struct nfsd_net *nn)
-{
-	return nfsd_percpu_counters_init(nn->counter, NFSD_STATS_COUNTERS_NUM);
-}
-
-void nfsd_stat_counters_destroy(struct nfsd_net *nn)
-{
-	nfsd_percpu_counters_destroy(nn->counter, NFSD_STATS_COUNTERS_NUM);
-}
-
 void nfsd_proc_stat_init(struct net *net)
 {
 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);

fs/nfsd/stats.h

@@ -10,11 +10,6 @@
 #include <uapi/linux/nfsd/stats.h>
 #include <linux/percpu_counter.h>
 
-int nfsd_percpu_counters_init(struct percpu_counter *counters, int num);
-void nfsd_percpu_counters_reset(struct percpu_counter *counters, int num);
-void nfsd_percpu_counters_destroy(struct percpu_counter *counters, int num);
-int nfsd_stat_counters_init(struct nfsd_net *nn);
-void nfsd_stat_counters_destroy(struct nfsd_net *nn);
 void nfsd_proc_stat_init(struct net *net);
 void nfsd_proc_stat_shutdown(struct net *net);