diff options
| -rw-r--r-- | fs/nfsd/netns.h | 3 | ||||
| -rw-r--r-- | fs/nfsd/nfssvc.c | 41 | ||||
| -rw-r--r-- | include/linux/sunrpc/svc.h | 13 |
3 files changed, 33 insertions, 24 deletions
diff --git a/fs/nfsd/netns.h b/fs/nfsd/netns.h index 08bcd8f23b01..1fd59eb0730b 100644 --- a/fs/nfsd/netns.h +++ b/fs/nfsd/netns.h @@ -134,9 +134,6 @@ struct nfsd_net { wait_queue_head_t ntf_wq; atomic_t ntf_refcnt; - /* Allow umount to wait for nfsd state cleanup */ - struct completion nfsd_shutdown_complete; - /* * clientid and stateid data for construction of net unique COPY * stateids. diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c index 097abd8b059c..d0d9107a1b93 100644 --- a/fs/nfsd/nfssvc.c +++ b/fs/nfsd/nfssvc.c @@ -593,20 +593,10 @@ static const struct svc_serv_ops nfsd_thread_sv_ops = { .svo_shutdown = nfsd_last_thread, .svo_function = nfsd, .svo_enqueue_xprt = svc_xprt_do_enqueue, - .svo_setup = svc_set_num_threads, + .svo_setup = svc_set_num_threads_sync, .svo_module = THIS_MODULE, }; -static void nfsd_complete_shutdown(struct net *net) -{ - struct nfsd_net *nn = net_generic(net, nfsd_net_id); - - WARN_ON(!mutex_is_locked(&nfsd_mutex)); - - nn->nfsd_serv = NULL; - complete(&nn->nfsd_shutdown_complete); -} - void nfsd_shutdown_threads(struct net *net) { struct nfsd_net *nn = net_generic(net, nfsd_net_id); @@ -624,8 +614,6 @@ void nfsd_shutdown_threads(struct net *net) serv->sv_ops->svo_setup(serv, NULL, 0); nfsd_put(net); mutex_unlock(&nfsd_mutex); - /* Wait for shutdown of nfsd_serv to complete */ - wait_for_completion(&nn->nfsd_shutdown_complete); } bool i_am_nfsd(void) @@ -650,7 +638,6 @@ int nfsd_create_serv(struct net *net) &nfsd_thread_sv_ops); if (nn->nfsd_serv == NULL) return -ENOMEM; - init_completion(&nn->nfsd_shutdown_complete); nn->nfsd_serv->sv_maxconn = nn->max_connections; error = svc_bind(nn->nfsd_serv, net); @@ -659,7 +646,7 @@ int nfsd_create_serv(struct net *net) * been set up yet. */ svc_put(nn->nfsd_serv); - nfsd_complete_shutdown(net); + nn->nfsd_serv = NULL; return error; } @@ -715,7 +702,7 @@ void nfsd_put(struct net *net) if (kref_put(&nn->nfsd_serv->sv_refcnt, nfsd_noop)) { svc_shutdown_net(nn->nfsd_serv, net); svc_destroy(&nn->nfsd_serv->sv_refcnt); - nfsd_complete_shutdown(net); + nn->nfsd_serv = NULL; } } @@ -743,7 +730,7 @@ int nfsd_set_nrthreads(int n, int *nthreads, struct net *net) if (tot > NFSD_MAXSERVS) { /* total too large: scale down requested numbers */ for (i = 0; i < n && tot > 0; i++) { - int new = nthreads[i] * NFSD_MAXSERVS / tot; + int new = nthreads[i] * NFSD_MAXSERVS / tot; tot -= (nthreads[i] - new); nthreads[i] = new; } @@ -989,10 +976,22 @@ out: /* Release the thread */ svc_exit_thread(rqstp); - /* Now if needed we call svc_destroy in appropriate context */ - mutex_lock(&nfsd_mutex); - nfsd_put(net); - mutex_unlock(&nfsd_mutex); + /* We need to drop a ref, but may not drop the last reference + * without holding nfsd_mutex, and we cannot wait for nfsd_mutex as that + * could deadlock with nfsd_shutdown_threads() waiting for us. + * So three options are: + * - drop a non-final reference, + * - get the mutex without waiting + * - sleep briefly andd try the above again + */ + while (!svc_put_not_last(nn->nfsd_serv)) { + if (mutex_trylock(&nfsd_mutex)) { + nfsd_put(net); + mutex_unlock(&nfsd_mutex); + break; + } + msleep(20); + } /* Release module */ module_put_and_exit(0); diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h index 3903b4ae8ac5..36bfc0281988 100644 --- a/include/linux/sunrpc/svc.h +++ b/include/linux/sunrpc/svc.h @@ -141,6 +141,19 @@ static inline void svc_put(struct svc_serv *serv) kref_put(&serv->sv_refcnt, svc_destroy); } +/** + * svc_put_not_last - decrement non-final reference count on SUNRPC serv + * @serv: the svc_serv to have count decremented + * + * Returns: %true is refcount was decremented. + * + * If the refcount is 1, it is not decremented and instead failure is reported. + */ +static inline bool svc_put_not_last(struct svc_serv *serv) +{ + return refcount_dec_not_one(&serv->sv_refcnt.refcount); +} + /* * Maximum payload size supported by a kernel RPC server. * This is use to determine the max number of pages nfsd is |