From 0d0f4aab4e4d290138a4ae7f2ef8469e48c9a669 Mon Sep 17 00:00:00 2001 From: Andrey Ryabinin Date: Wed, 7 Oct 2015 14:39:55 +0300 Subject: 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: Andrey Ryabinin Signed-off-by: J. Bruce Fields --- fs/lockd/mon.c | 89 ++++++++++------------------------------------------------ 1 file changed, 15 insertions(+), 74 deletions(-) (limited to 'fs/lockd/mon.c') diff --git a/fs/lockd/mon.c b/fs/lockd/mon.c index 6c05cd17e520..19166d4a8d31 100644 --- a/fs/lockd/mon.c +++ b/fs/lockd/mon.c @@ -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); } } -- cgit v1.2.3-70-g09d2