diff options
Diffstat (limited to 'fs/nfsd/nfssvc.c')
| -rw-r--r-- | fs/nfsd/nfssvc.c | 42 |
1 files changed, 26 insertions, 16 deletions
diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c index a0a7564e6c73..5f605e7e8091 100644 --- a/fs/nfsd/nfssvc.c +++ b/fs/nfsd/nfssvc.c @@ -60,13 +60,13 @@ static __be32 nfsd_init_request(struct svc_rqst *, * extent ->sv_temp_socks and ->sv_permsocks. It also protects nfsdstats.th_cnt * * If (out side the lock) nn->nfsd_serv is non-NULL, then it must point to a - * properly initialised 'struct svc_serv' with ->sv_nrthreads > 0. That number - * of nfsd threads must exist and each must listed in ->sp_all_threads in each - * entry of ->sv_pools[]. + * properly initialised 'struct svc_serv' with ->sv_nrthreads > 0 (unless + * nn->keep_active is set). That number of nfsd threads must + * exist and each must be listed in ->sp_all_threads in some entry of + * ->sv_pools[]. * - * Transitions of the thread count between zero and non-zero are of particular - * interest since the svc_serv needs to be created and initialized at that - * point, or freed. + * Each active thread holds a counted reference on nn->nfsd_serv, as does + * the nn->keep_active flag and various transient calls to svc_get(). * * Finally, the nfsd_mutex also protects some of the global variables that are * accessed when nfsd starts and that are settable via the write_* routines in @@ -700,14 +700,22 @@ int nfsd_get_nrthreads(int n, int *nthreads, struct net *net) return 0; } +/* This is the callback for kref_put() below. + * There is no code here as the first thing to be done is + * call svc_shutdown_net(), but we cannot get the 'net' from + * the kref. So do all the work when kref_put returns true. + */ +static void nfsd_noop(struct kref *ref) +{ +} + void nfsd_put(struct net *net) { struct nfsd_net *nn = net_generic(net, nfsd_net_id); - nn->nfsd_serv->sv_nrthreads -= 1; - if (nn->nfsd_serv->sv_nrthreads == 0) { + if (kref_put(&nn->nfsd_serv->sv_refcnt, nfsd_noop)) { svc_shutdown_net(nn->nfsd_serv, net); - svc_destroy(nn->nfsd_serv); + svc_destroy(&nn->nfsd_serv->sv_refcnt); nfsd_complete_shutdown(net); } } @@ -803,15 +811,14 @@ nfsd_svc(int nrservs, struct net *net, const struct cred *cred) NULL, nrservs); if (error) goto out_shutdown; - /* We are holding a reference to nn->nfsd_serv which - * we don't want to count in the return value, - * so subtract 1 - */ - error = nn->nfsd_serv->sv_nrthreads - 1; + error = nn->nfsd_serv->sv_nrthreads; out_shutdown: if (error < 0 && !nfsd_up_before) nfsd_shutdown_net(net); out_put: + /* Threads now hold service active */ + if (xchg(&nn->keep_active, 0)) + nfsd_put(net); nfsd_put(net); out: mutex_unlock(&nfsd_mutex); @@ -980,11 +987,15 @@ nfsd(void *vrqstp) nfsdstats.th_cnt --; out: - rqstp->rq_server = NULL; + /* Take an extra ref so that the svc_put in svc_exit_thread() + * doesn't call svc_destroy() + */ + svc_get(nn->nfsd_serv); /* Release the thread */ svc_exit_thread(rqstp); + /* Now if needed we call svc_destroy in appropriate context */ nfsd_put(net); /* Release module */ @@ -1099,7 +1110,6 @@ int nfsd_pool_stats_open(struct inode *inode, struct file *file) mutex_unlock(&nfsd_mutex); return -ENODEV; } - /* bump up the psudo refcount while traversing */ svc_get(nn->nfsd_serv); ret = svc_pool_stats_open(nn->nfsd_serv, file); mutex_unlock(&nfsd_mutex); |