nfs: make the rpc_stat per net namespace

BugLink: https://bugs.launchpad.net/bugs/2070028

[ Upstream commit 1548036 ]

Now that we're exposing the rpc stats on a per-network namespace basis,
move this struct into struct nfs_net and use that to make sure only the
per-network namespace stats are exposed.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Stable-dep-of: 24457f1 ("nfs: Handle error of rpc_proc_register() in nfs_net_init().")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Manuel Diewald <manuel.diewald@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

Author: josefbacik

fs/nfs/client.c

@@ -73,7 +73,6 @@ const struct rpc_program nfs_program = {
 	.number			= NFS_PROGRAM,
 	.nrvers			= ARRAY_SIZE(nfs_version),
 	.version		= nfs_version,
-	.stats			= &nfs_rpcstat,
 	.pipe_dir_name		= NFS_PIPE_DIRNAME,
 };
 
@@ -500,6 +499,7 @@ int nfs_create_rpc_client(struct nfs_client *clp,
 			  const struct nfs_client_initdata *cl_init,
 			  rpc_authflavor_t flavor)
 {
+	struct nfs_net		*nn = net_generic(clp->cl_net, nfs_net_id);
 	struct rpc_clnt		*clnt = NULL;
 	struct rpc_create_args args = {
 		.net		= clp->cl_net,
@@ -511,6 +511,7 @@ int nfs_create_rpc_client(struct nfs_client *clp,
 		.servername	= clp->cl_hostname,
 		.nodename	= cl_init->nodename,
 		.program	= &nfs_program,
+		.stats		= &nn->rpcstats,
 		.version	= clp->rpc_ops->version,
 		.authflavor	= flavor,
 		.cred		= cl_init->cred,
@@ -1129,6 +1130,8 @@ void nfs_clients_init(struct net *net)
 #endif
 	spin_lock_init(&nn->nfs_client_lock);
 	nn->boot_time = ktime_get_real();
+	memset(&nn->rpcstats, 0, sizeof(nn->rpcstats));
+	nn->rpcstats.program = &nfs_program;
 
 	nfs_netns_sysfs_setup(nn, net);
 }

fs/nfs/inode.c

@@ -2360,8 +2360,10 @@ EXPORT_SYMBOL_GPL(nfs_net_id);
 
 static int nfs_net_init(struct net *net)
 {
+	struct nfs_net *nn = net_generic(net, nfs_net_id);
+
 	nfs_clients_init(net);
-	rpc_proc_register(net, &nfs_rpcstat);
+	rpc_proc_register(net, &nn->rpcstats);
 	return nfs_fs_proc_net_init(net);
 }
 

fs/nfs/internal.h

@@ -428,8 +428,6 @@ int nfs_try_get_tree(struct fs_context *);
 int nfs_get_tree_common(struct fs_context *);
 void nfs_kill_super(struct super_block *);
 
-extern struct rpc_stat nfs_rpcstat;
-
 extern int __init register_nfs_fs(void);
 extern void __exit unregister_nfs_fs(void);
 extern bool nfs_sb_active(struct super_block *sb);

fs/nfs/netns.h

@@ -9,6 +9,7 @@
 #include <linux/nfs4.h>
 #include <net/net_namespace.h>
 #include <net/netns/generic.h>
+#include <linux/sunrpc/stats.h>
 
 struct bl_dev_msg {
 	int32_t status;
@@ -34,6 +35,7 @@ struct nfs_net {
 	struct nfs_netns_client *nfs_client;
 	spinlock_t nfs_client_lock;
 	ktime_t boot_time;
+	struct rpc_stat rpcstats;
 #ifdef CONFIG_PROC_FS
 	struct proc_dir_entry *proc_nfsfs;
 #endif