If multiple processes are locking the same file, the NSMPROC_MON
message would be send more than one times when the host is not
monitored by the peer.
Add a mutex to ensure that we just send once. If some one has send
the msg, Just waiting for the result or try again if failed.
Signed-off-by: ZhangXiaoxu <zhangxiaoxu5@xxxxxxxxxx>
---
fs/lockd/mon.c | 10 ++++++++++
include/linux/lockd/lockd.h | 1 +
2 files changed, 11 insertions(+)
diff --git a/fs/lockd/mon.c b/fs/lockd/mon.c
index 654594e..4ba2658 100644
--- a/fs/lockd/mon.c
+++ b/fs/lockd/mon.c
@@ -155,6 +155,12 @@ int nsm_monitor(const struct nlm_host *host)
if (nsm->sm_monitored)
return 0;
+ mutex_lock(&nsm->mutex);
+ if (nsm->sm_monitored) {
+ mutex_unlock(&nsm->mutex);
+ return 0;
+ }
+
/*
* Choose whether to record the caller_name or IP address of
* this peer in the local rpc.statd's database.
@@ -165,6 +171,7 @@ int nsm_monitor(const struct nlm_host *host)
if (unlikely(res.status != 0))
status = -EIO;
if (unlikely(status < 0)) {
+ mutex_unlock(&nsm->mutex);
pr_notice_ratelimited("lockd: cannot monitor %s\n", nsm->sm_name);
return status;
}
@@ -174,6 +181,8 @@ int nsm_monitor(const struct nlm_host *host)
nsm_local_state = res.state;
dprintk("lockd: NSM state changed to %d\n", nsm_local_state);
}
+
+ mutex_unlock(&nsm->mutex);
return 0;
}
@@ -284,6 +293,7 @@ static struct nsm_handle *nsm_create_handle(const struct sockaddr *sap,
memcpy(nsm_addr(new), sap, salen);
new->sm_addrlen = salen;
nsm_init_private(new);
+ mutex_init(&new->mutex);
if (rpc_ntop(nsm_addr(new), new->sm_addrbuf,
sizeof(new->sm_addrbuf)) == 0)
diff --git a/include/linux/lockd/lockd.h b/include/linux/lockd/lockd.h
index b065ef4..c56069c 100644
--- a/include/linux/lockd/lockd.h
+++ b/include/linux/lockd/lockd.h
@@ -89,6 +89,7 @@ struct nsm_handle {
char *sm_name;
struct sockaddr_storage sm_addr;
size_t sm_addrlen;
+ struct mutex mutex; /* should be send only once even more threads */
unsigned int sm_monitored : 1,
sm_sticky : 1; /* don't unmonitor */
struct nsm_private sm_priv;
--
2.7.4
