Commit 0d0f4aab authored by Andrey Ryabinin's avatar Andrey Ryabinin Committed by J. Bruce Fields
Browse files

lockd: get rid of reference-counted NSM RPC clients 



Currently we have reference-counted per-net NSM RPC client
which created on the first monitor request and destroyed
after the last unmonitor request. It's needed because
RPC client need to know 'utsname()->nodename', but utsname()
might be NULL when nsm_unmonitor() called.

So instead of holding the rpc client we could just save nodename
in struct nlm_host and pass it to the rpc_create().
Thus ther is no need in keeping rpc client until last
unmonitor request. We could create separate RPC clients
for each monitor/unmonitor requests.

Signed-off-by: default avatarAndrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: default avatarJ. Bruce Fields <bfields@redhat.com>
parent 226453d8

fs/lockd/host.c

+1 −0
Original line number Diff line number Diff line
@@ -161,6 +161,7 @@ static struct nlm_host *nlm_alloc_host(struct nlm_lookup_host_info *ni, 
	host->h_nsmhandle  = nsm;

	host->h_addrbuf    = nsm->sm_addrbuf;

	host->net	   = ni->net;

	strlcpy(host->nodename, utsname()->nodename, sizeof(host->nodename));



out:

	return host;

fs/lockd/mon.c

+15 −74
Original line number Diff line number Diff line
@@ -42,7 +42,7 @@ struct nsm_args { 
	u32			proc;



	char			*mon_name;

	char			*nodename;

	const char		*nodename;

};



struct nsm_res {
@@ -86,69 +86,18 @@ static struct rpc_clnt *nsm_create(struct net *net, const char *nodename) 
	return rpc_create(&args);

}



static struct rpc_clnt *nsm_client_set(struct lockd_net *ln,

		struct rpc_clnt *clnt)

{

	spin_lock(&ln->nsm_clnt_lock);

	if (ln->nsm_users == 0) {

		if (clnt == NULL)

			goto out;

		ln->nsm_clnt = clnt;

	}

	clnt = ln->nsm_clnt;

	ln->nsm_users++;

out:

	spin_unlock(&ln->nsm_clnt_lock);

	return clnt;

}



static struct rpc_clnt *nsm_client_get(struct net *net, const char *nodename)

{

	struct rpc_clnt	*clnt, *new;

	struct lockd_net *ln = net_generic(net, lockd_net_id);



	clnt = nsm_client_set(ln, NULL);

	if (clnt != NULL)

		goto out;



	clnt = new = nsm_create(net, nodename);

	if (IS_ERR(clnt))

		goto out;



	clnt = nsm_client_set(ln, new);

	if (clnt != new)

		rpc_shutdown_client(new);

out:

	return clnt;

}



static void nsm_client_put(struct net *net)

{

	struct lockd_net *ln = net_generic(net, lockd_net_id);

	struct rpc_clnt	*clnt = NULL;



	spin_lock(&ln->nsm_clnt_lock);

	ln->nsm_users--;

	if (ln->nsm_users == 0) {

		clnt = ln->nsm_clnt;

		ln->nsm_clnt = NULL;

	}

	spin_unlock(&ln->nsm_clnt_lock);

	if (clnt != NULL)

		rpc_shutdown_client(clnt);

}



static int nsm_mon_unmon(struct nsm_handle *nsm, u32 proc, struct nsm_res *res,

			 struct rpc_clnt *clnt)

			 const struct nlm_host *host)

{

	int		status;

	struct rpc_clnt *clnt;

	struct nsm_args args = {

		.priv		= &nsm->sm_priv,

		.prog		= NLM_PROGRAM,

		.vers		= 3,

		.proc		= NLMPROC_NSM_NOTIFY,

		.mon_name	= nsm->sm_mon_name,

		.nodename	= clnt->cl_nodename,

		.nodename	= host->nodename,

	};

	struct rpc_message msg = {

		.rpc_argp	= &args,
@@ -157,6 +106,13 @@ static int nsm_mon_unmon(struct nsm_handle *nsm, u32 proc, struct nsm_res *res, 


	memset(res, 0, sizeof(*res));



	clnt = nsm_create(host->net, host->nodename);

	if (IS_ERR(clnt)) {

		dprintk("lockd: failed to create NSM upcall transport, "

			"status=%ld, net=%p\n", PTR_ERR(clnt), host->net);

		return PTR_ERR(clnt);

	}



	msg.rpc_proc = &clnt->cl_procinfo[proc];

	status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFTCONN);

	if (status == -ECONNREFUSED) {
@@ -170,6 +126,8 @@ static int nsm_mon_unmon(struct nsm_handle *nsm, u32 proc, struct nsm_res *res, 
				status);

	else

		status = 0;



	rpc_shutdown_client(clnt);

	return status;

}
@@ -189,32 +147,19 @@ int nsm_monitor(const struct nlm_host *host) 
	struct nsm_handle *nsm = host->h_nsmhandle;

	struct nsm_res	res;

	int		status;

	struct rpc_clnt *clnt;

	const char *nodename = NULL;



	dprintk("lockd: nsm_monitor(%s)\n", nsm->sm_name);



	if (nsm->sm_monitored)

		return 0;



	if (host->h_rpcclnt)

		nodename = host->h_rpcclnt->cl_nodename;



	/*

	 * Choose whether to record the caller_name or IP address of

	 * this peer in the local rpc.statd's database.

	 */

	nsm->sm_mon_name = nsm_use_hostnames ? nsm->sm_name : nsm->sm_addrbuf;



	clnt = nsm_client_get(host->net, nodename);

	if (IS_ERR(clnt)) {

		status = PTR_ERR(clnt);

		dprintk("lockd: failed to create NSM upcall transport, "

				"status=%d, net=%p\n", status, host->net);

		return status;

	}



	status = nsm_mon_unmon(nsm, NSMPROC_MON, &res, clnt);

	status = nsm_mon_unmon(nsm, NSMPROC_MON, &res, host);

	if (unlikely(res.status != 0))

		status = -EIO;

	if (unlikely(status < 0)) {
@@ -246,11 +191,9 @@ void nsm_unmonitor(const struct nlm_host *host) 


	if (atomic_read(&nsm->sm_count) == 1

	 && nsm->sm_monitored && !nsm->sm_sticky) {

		struct lockd_net *ln = net_generic(host->net, lockd_net_id);



		dprintk("lockd: nsm_unmonitor(%s)\n", nsm->sm_name);



		status = nsm_mon_unmon(nsm, NSMPROC_UNMON, &res, ln->nsm_clnt);

		status = nsm_mon_unmon(nsm, NSMPROC_UNMON, &res, host);

		if (res.status != 0)

			status = -EIO;

		if (status < 0)
@@ -258,8 +201,6 @@ void nsm_unmonitor(const struct nlm_host *host) 
					nsm->sm_name);

		else

			nsm->sm_monitored = 0;



		nsm_client_put(host->net);

	}

}

fs/lockd/netns.h

+0 −3
Original line number Diff line number Diff line
@@ -12,9 +12,6 @@ struct lockd_net { 
	struct delayed_work grace_period_end;

	struct lock_manager lockd_manager;



	spinlock_t nsm_clnt_lock;

	unsigned int nsm_users;

	struct rpc_clnt *nsm_clnt;

	struct list_head nsm_handles;

};

fs/lockd/svc.c

+0 −1
Original line number Diff line number Diff line
@@ -592,7 +592,6 @@ static int lockd_init_net(struct net *net) 
	INIT_DELAYED_WORK(&ln->grace_period_end, grace_ender);

	INIT_LIST_HEAD(&ln->lockd_manager.list);

	ln->lockd_manager.block_opens = false;

	spin_lock_init(&ln->nsm_clnt_lock);

	INIT_LIST_HEAD(&ln->nsm_handles);

	return 0;

}

include/linux/lockd/lockd.h

+1 −0
Original line number Diff line number Diff line
@@ -68,6 +68,7 @@ struct nlm_host { 
	struct nsm_handle	*h_nsmhandle;	/* NSM status handle */

	char			*h_addrbuf;	/* address eyecatcher */

	struct net		*net;		/* host net */

	char			nodename[UNX_MAXNODENAME + 1];

};



/*

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