Both nfsd and nfsv4-callback take a temporary reference to the svc_serv
while calling svc_set_num_threads() to stop the last thread. lockd does
not.
This extra reference prevents the scv_serv from being freed when the
last thread drops its reference count. This not currently needed for
lockd as the svc_serv is not accessed after the last thread is told to
exit.
However a future patch will require svc_exit_thread() to access the
svc_serv after the svc_put() so it will need the code that calls
svc_set_num_threads() to keep a reference and keep the svc_serv active.
So copy the pattern from nfsd and nfsv4-cb to lockd, and take a
reference around svc_set_num_threads(.., 0)
Reviewed-by: Jeff Layton <jlayton@xxxxxxxxxx>
Tested-by: Jeff Layton <jlayton@xxxxxxxxxx>
Signed-off-by: NeilBrown <neilb@xxxxxxx>
---
fs/lockd/svc.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c
index 6579948070a4..365cc7adff66 100644
--- a/fs/lockd/svc.c
+++ b/fs/lockd/svc.c
@@ -373,7 +373,9 @@ static void lockd_put(void)
unregister_inet6addr_notifier(&lockd_inet6addr_notifier);
#endif
+ svc_get(nlmsvc_serv);
svc_set_num_threads(nlmsvc_serv, NULL, 0);
+ svc_put(nlmsvc_serv);
timer_delete_sync(&nlmsvc_retry);
nlmsvc_serv = NULL;
dprintk("lockd_down: service destroyed\n");
--
2.42.0
