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Date: Wed, 7 Oct 2015 14:39:55 +0300
From: Andrey Ryabinin <aryabinin@...tuozzo.com>
To: Trond Myklebust <trond.myklebust@...marydata.com>,
Anna Schumaker <anna.schumaker@...app.com>,
"J. Bruce Fields" <bfields@...ldses.org>,
Jeff Layton <jlayton@...chiereds.net>
CC: <linux-nfs@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
Stanislav Kinsbursky <skinsbursky@...tuozzo.com>,
kbuild test robot <lkp@...el.com>, <kbuild-all@...org>,
Andrey Ryabinin <aryabinin@...tuozzo.com>
Subject: [PATCH v2] 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 <aryabinin@...tuozzo.com>
---
Changes since v1:
- fixed build warning:
fs/lockd/mon.c:111:3: warning: format '%d' expects argument of type 'int', but argument 2 has type 'long int' [-Wformat=]
fs/lockd/host.c | 1 +
fs/lockd/mon.c | 89 ++++++++-------------------------------------
fs/lockd/netns.h | 3 --
fs/lockd/svc.c | 1 -
include/linux/lockd/lockd.h | 1 +
5 files changed, 17 insertions(+), 78 deletions(-)
diff --git a/fs/lockd/host.c b/fs/lockd/host.c
index b5f3c3a..d716c99 100644
--- a/fs/lockd/host.c
+++ b/fs/lockd/host.c
@@ -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;
diff --git a/fs/lockd/mon.c b/fs/lockd/mon.c
index 6c05cd1..19166d4 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);
}
}
diff --git a/fs/lockd/netns.h b/fs/lockd/netns.h
index 89fe011..5426189 100644
--- a/fs/lockd/netns.h
+++ b/fs/lockd/netns.h
@@ -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;
};
diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c
index 0dff13f..5f31ebd 100644
--- a/fs/lockd/svc.c
+++ b/fs/lockd/svc.c
@@ -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;
}
diff --git a/include/linux/lockd/lockd.h b/include/linux/lockd/lockd.h
index fd3b65b..c153738 100644
--- a/include/linux/lockd/lockd.h
+++ b/include/linux/lockd/lockd.h
@@ -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];
};
/*
--
2.4.9
--
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