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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@virtuozzo.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
This commit is contained in:
Andrey Ryabinin 2015-10-07 14:39:55 +03:00 committed by J. Bruce Fields
parent 226453d8cf
commit 0d0f4aab4e
5 changed files with 17 additions and 78 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
fs/lockd/host.c
View File

@ -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;

89
fs/lockd/mon.c
View File

@ -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);
}
}

3
fs/lockd/netns.h
View File

@ -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;
};

1
fs/lockd/svc.c
View File

@ -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;
}

1
include/linux/lockd/lockd.h
View File

@ -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];
};
/*