We are required to hold a reference to the svc_serv struct while
stopping the last thread, as doing that could otherwise drop the last
reference itself and the svc_serv would be freed while still in use.
lockd doesn't do this. After startup, the only reference is held by the
running thread.
So change locked to hold a reference on nlmsvc_serv while-ever the
service is active, and only drop it after the last thread has been
stopped.
Note: it doesn't really make sense for threads to hold references to the
svc_serv any more. The fact threads are included in serv->sv_nrthreads
is sufficient. Maybe a future patch could address this.
Reported-by: Jeff Layton <jlayton@xxxxxxxxxx>
Fixes: 68cc388c3238 ("SUNRPC: change how svc threads are asked to exit.")
Signed-off-by: NeilBrown <neilb@xxxxxxx>
---
Thanks for the report Jeff !!!
fs/lockd/svc.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c
index b441c706c2b8..7a5c90a00522 100644
--- a/fs/lockd/svc.c
+++ b/fs/lockd/svc.c
@@ -345,10 +345,10 @@ static int lockd_get(void)
serv->sv_maxconn = nlm_max_connections;
error = svc_set_num_threads(serv, NULL, 1);
- /* The thread now holds the only reference */
- svc_put(serv);
- if (error < 0)
+ if (error < 0) {
+ svc_put(serv);
return error;
+ }
nlmsvc_serv = serv;
register_inetaddr_notifier(&lockd_inetaddr_notifier);
@@ -374,6 +374,7 @@ static void lockd_put(void)
svc_set_num_threads(nlmsvc_serv, NULL, 0);
timer_delete_sync(&nlmsvc_retry);
+ svc_put(nlmsvc_serv);
nlmsvc_serv = NULL;
dprintk("lockd_down: service destroyed\n");
}
--
2.42.0
