Merge tag 'nfs-for-3.11-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

Pull NFS client updates from Trond Myklebust:
 "Feature highlights include:
   - Add basic client support for NFSv4.2
   - Add basic client support for Labeled NFS (selinux for NFSv4.2)
   - Fix the use of credentials in NFSv4.1 stateful operations, and add
     support for NFSv4.1 state protection.

  Bugfix highlights:
   - Fix another NFSv4 open state recovery race
   - Fix an NFSv4.1 back channel session regression
   - Various rpc_pipefs races
   - Fix another issue with NFSv3 auth negotiation

  Please note that Labeled NFS does require some additional support from
  the security subsystem.  The relevant changesets have all been
  reviewed and acked by James Morris."

* tag 'nfs-for-3.11-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (54 commits)
  NFS: Set NFS_CS_MIGRATION for NFSv4 mounts
  NFSv4.1 Refactor nfs4_init_session and nfs4_init_channel_attrs
  nfs: have NFSv3 try server-specified auth flavors in turn
  nfs: have nfs_mount fake up a auth_flavs list when the server didn't provide it
  nfs: move server_authlist into nfs_try_mount_request
  nfs: refactor "need_mount" code out of nfs_try_mount
  SUNRPC: PipeFS MOUNT notification optimization for dying clients
  SUNRPC: split client creation routine into setup and registration
  SUNRPC: fix races on PipeFS UMOUNT notifications
  SUNRPC: fix races on PipeFS MOUNT notifications
  NFSv4.1 use pnfs_device maxcount for the objectlayout gdia_maxcount
  NFSv4.1 use pnfs_device maxcount for the blocklayout gdia_maxcount
  NFSv4.1 Fix gdia_maxcount calculation to fit in ca_maxresponsesize
  NFS: Improve legacy idmapping fallback
  NFSv4.1 end back channel session draining
  NFS: Apply v4.1 capabilities to v4.2
  NFSv4.1: Clean up layout segment comparison helper names
  NFSv4.1: layout segment comparison helpers should take 'const' parameters
  NFSv4: Move the DNS resolver into the NFSv4 module
  rpc_pipefs: only set rpc_dentry_ops if d_op isn't already set
  ...

1 files changed, 44 insertions, 27 deletions

diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 5a750b9c3640..f0339ae9bf37 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -157,20 +157,15 @@ static struct dentry *rpc_setup_pipedir_sb(struct super_block *sb,
 }
 
 static int
-rpc_setup_pipedir(struct rpc_clnt *clnt, const char *dir_name)
+rpc_setup_pipedir(struct rpc_clnt *clnt, const char *dir_name,
+		  struct super_block *pipefs_sb)
 {
-	struct net *net = rpc_net_ns(clnt);
-	struct super_block *pipefs_sb;
 	struct dentry *dentry;
 
 	clnt->cl_dentry = NULL;
 	if (dir_name == NULL)
 		return 0;
-	pipefs_sb = rpc_get_sb_net(net);
-	if (!pipefs_sb)
-		return 0;
 	dentry = rpc_setup_pipedir_sb(pipefs_sb, clnt, dir_name);
-	rpc_put_sb_net(net);
 	if (IS_ERR(dentry))
 		return PTR_ERR(dentry);
 	clnt->cl_dentry = dentry;
@@ -182,6 +177,8 @@ static inline int rpc_clnt_skip_event(struct rpc_clnt *clnt, unsigned long event
 	if (((event == RPC_PIPEFS_MOUNT) && clnt->cl_dentry) ||
 	    ((event == RPC_PIPEFS_UMOUNT) && !clnt->cl_dentry))
 		return 1;
+	if ((event == RPC_PIPEFS_MOUNT) && atomic_read(&clnt->cl_count) == 0)
+		return 1;
 	return 0;
 }
 
@@ -241,8 +238,6 @@ static struct rpc_clnt *rpc_get_client_for_event(struct net *net, int event)
 			continue;
 		if (rpc_clnt_skip_event(clnt, event))
 			continue;
-		if (atomic_inc_not_zero(&clnt->cl_count) == 0)
-			continue;
 		spin_unlock(&sn->rpc_client_lock);
 		return clnt;
 	}
@@ -259,7 +254,6 @@ static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
 
 	while ((clnt = rpc_get_client_for_event(sb->s_fs_info, event))) {
 		error = __rpc_pipefs_event(clnt, event, sb);
-		rpc_release_client(clnt);
 		if (error)
 			break;
 	}
@@ -289,12 +283,46 @@ static void rpc_clnt_set_nodename(struct rpc_clnt *clnt, const char *nodename)
 	memcpy(clnt->cl_nodename, nodename, clnt->cl_nodelen);
 }
 
+static int rpc_client_register(const struct rpc_create_args *args,
+			       struct rpc_clnt *clnt)
+{
+	const struct rpc_program *program = args->program;
+	struct rpc_auth *auth;
+	struct net *net = rpc_net_ns(clnt);
+	struct super_block *pipefs_sb;
+	int err = 0;
+
+	pipefs_sb = rpc_get_sb_net(net);
+	if (pipefs_sb) {
+		err = rpc_setup_pipedir(clnt, program->pipe_dir_name, pipefs_sb);
+		if (err)
+			goto out;
+	}
+
+	auth = rpcauth_create(args->authflavor, clnt);
+	if (IS_ERR(auth)) {
+		dprintk("RPC:       Couldn't create auth handle (flavor %u)\n",
+				args->authflavor);
+		err = PTR_ERR(auth);
+		goto err_auth;
+	}
+
+	rpc_register_client(clnt);
+out:
+	if (pipefs_sb)
+		rpc_put_sb_net(net);
+	return err;
+
+err_auth:
+	__rpc_clnt_remove_pipedir(clnt);
+	goto out;
+}
+
 static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args, struct rpc_xprt *xprt)
 {
 	const struct rpc_program *program = args->program;
 	const struct rpc_version *version;
 	struct rpc_clnt		*clnt = NULL;
-	struct rpc_auth		*auth;
 	int err;
 
 	/* sanity check the name before trying to print it */
@@ -354,25 +382,14 @@ static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args, stru
 
 	atomic_set(&clnt->cl_count, 1);
 
-	err = rpc_setup_pipedir(clnt, program->pipe_dir_name);
-	if (err < 0)
-		goto out_no_path;
-
-	auth = rpcauth_create(args->authflavor, clnt);
-	if (IS_ERR(auth)) {
-		dprintk("RPC:       Couldn't create auth handle (flavor %u)\n",
-				args->authflavor);
-		err = PTR_ERR(auth);
-		goto out_no_auth;
-	}
-
 	/* save the nodename */
 	rpc_clnt_set_nodename(clnt, utsname()->nodename);
-	rpc_register_client(clnt);
+
+	err = rpc_client_register(args, clnt);
+	if (err)
+		goto out_no_path;
 	return clnt;
 
-out_no_auth:
-	rpc_clnt_remove_pipedir(clnt);
 out_no_path:
 	kfree(clnt->cl_principal);
 out_no_principal:
@@ -637,8 +654,8 @@ rpc_free_client(struct rpc_clnt *clnt)
 			rcu_dereference(clnt->cl_xprt)->servername);
 	if (clnt->cl_parent != clnt)
 		rpc_release_client(clnt->cl_parent);
-	rpc_unregister_client(clnt);
 	rpc_clnt_remove_pipedir(clnt);
+	rpc_unregister_client(clnt);
 	rpc_free_iostats(clnt->cl_metrics);
 	kfree(clnt->cl_principal);
 	clnt->cl_metrics = NULL;