| Message ID | 20230731064839.7729-6-neilb@suse.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | SUNRPC: various thread management improvements | expand |
On Mon, Jul 31, 2023 at 04:48:32PM +1000, NeilBrown wrote: > Now that the last nfsd thread is stopped by an explicit act of calling > svc_set_num_threads() with a count of zero, we only have a limited > number of places that can happen, and don't need to call > nfsd_last_thread() in nfsd_put() > > So separate that out and call it at the two places where the number of > threads is set to zero. > > Move the clearing of ->nfsd_serv and the call to svc_xprt_destroy_all() > into nfsd_last_thread(), as they are really part of the same action. > > nfsd_put() is now a thin wrapper around svc_put(), so make it a static inline. > > nfsd_put() cannot be called after nfsd_last_thread(), so in a couple of > places we have to use svc_put() instead. > > Signed-off-by: NeilBrown <neilb@suse.de> I've applied 4/12 and 5/12. I'll push these out later today. > --- > fs/nfsd/nfsd.h | 7 ++++++- > fs/nfsd/nfssvc.c | 52 ++++++++++++++++++------------------------------ > 2 files changed, 25 insertions(+), 34 deletions(-) > > diff --git a/fs/nfsd/nfsd.h b/fs/nfsd/nfsd.h > index d88498f8b275..11c14faa6c67 100644 > --- a/fs/nfsd/nfsd.h > +++ b/fs/nfsd/nfsd.h > @@ -96,7 +96,12 @@ int nfsd_pool_stats_open(struct inode *, struct file *); > int nfsd_pool_stats_release(struct inode *, struct file *); > void nfsd_shutdown_threads(struct net *net); > > -void nfsd_put(struct net *net); > +static inline void nfsd_put(struct net *net) > +{ > + struct nfsd_net *nn = net_generic(net, nfsd_net_id); > + > + svc_put(nn->nfsd_serv); > +} > > bool i_am_nfsd(void); > > diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c > index 33a80725e14e..1582af33e204 100644 > --- a/fs/nfsd/nfssvc.c > +++ b/fs/nfsd/nfssvc.c > @@ -542,9 +542,14 @@ static struct notifier_block nfsd_inet6addr_notifier = { > /* Only used under nfsd_mutex, so this atomic may be overkill: */ > static atomic_t nfsd_notifier_refcount = ATOMIC_INIT(0); > > -static void nfsd_last_thread(struct svc_serv *serv, struct net *net) > +static void nfsd_last_thread(struct net *net) > { > struct nfsd_net *nn = net_generic(net, nfsd_net_id); > + struct svc_serv *serv = nn->nfsd_serv; > + > + spin_lock(&nfsd_notifier_lock); > + nn->nfsd_serv = NULL; > + spin_unlock(&nfsd_notifier_lock); > > /* check if the notifier still has clients */ > if (atomic_dec_return(&nfsd_notifier_refcount) == 0) { > @@ -554,6 +559,8 @@ static void nfsd_last_thread(struct svc_serv *serv, struct net *net) > #endif > } > > + svc_xprt_destroy_all(serv, net); > + > /* > * write_ports can create the server without actually starting > * any threads--if we get shut down before any threads are > @@ -644,7 +651,8 @@ void nfsd_shutdown_threads(struct net *net) > svc_get(serv); > /* Kill outstanding nfsd threads */ > svc_set_num_threads(serv, NULL, 0); > - nfsd_put(net); > + nfsd_last_thread(net); > + svc_put(serv); > mutex_unlock(&nfsd_mutex); > } > > @@ -674,9 +682,6 @@ int nfsd_create_serv(struct net *net) > serv->sv_maxconn = nn->max_connections; > error = svc_bind(serv, net); > if (error < 0) { > - /* NOT nfsd_put() as notifiers (see below) haven't > - * been set up yet. > - */ > svc_put(serv); > return error; > } > @@ -719,29 +724,6 @@ 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); > - > - if (kref_put(&nn->nfsd_serv->sv_refcnt, nfsd_noop)) { > - svc_xprt_destroy_all(nn->nfsd_serv, net); > - nfsd_last_thread(nn->nfsd_serv, net); > - svc_destroy(&nn->nfsd_serv->sv_refcnt); > - spin_lock(&nfsd_notifier_lock); > - nn->nfsd_serv = NULL; > - spin_unlock(&nfsd_notifier_lock); > - } > -} > - > int nfsd_set_nrthreads(int n, int *nthreads, struct net *net) > { > int i = 0; > @@ -792,7 +774,7 @@ int nfsd_set_nrthreads(int n, int *nthreads, struct net *net) > if (err) > break; > } > - nfsd_put(net); > + svc_put(nn->nfsd_serv); > return err; > } > > @@ -807,6 +789,7 @@ nfsd_svc(int nrservs, struct net *net, const struct cred *cred) > int error; > bool nfsd_up_before; > struct nfsd_net *nn = net_generic(net, nfsd_net_id); > + struct svc_serv *serv; > > mutex_lock(&nfsd_mutex); > dprintk("nfsd: creating service\n"); > @@ -826,22 +809,25 @@ nfsd_svc(int nrservs, struct net *net, const struct cred *cred) > goto out; > > nfsd_up_before = nn->nfsd_net_up; > + serv = nn->nfsd_serv; > > error = nfsd_startup_net(net, cred); > if (error) > goto out_put; > - error = svc_set_num_threads(nn->nfsd_serv, NULL, nrservs); > + error = svc_set_num_threads(serv, NULL, nrservs); > if (error) > goto out_shutdown; > - error = nn->nfsd_serv->sv_nrthreads; > + error = serv->sv_nrthreads; > + if (error == 0) > + nfsd_last_thread(net); > 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); > + svc_put(serv); > + svc_put(serv); > out: > mutex_unlock(&nfsd_mutex); > return error; > -- > 2.40.1 >
diff --git a/fs/nfsd/nfsd.h b/fs/nfsd/nfsd.h index d88498f8b275..11c14faa6c67 100644 --- a/fs/nfsd/nfsd.h +++ b/fs/nfsd/nfsd.h @@ -96,7 +96,12 @@ int nfsd_pool_stats_open(struct inode *, struct file *); int nfsd_pool_stats_release(struct inode *, struct file *); void nfsd_shutdown_threads(struct net *net); -void nfsd_put(struct net *net); +static inline void nfsd_put(struct net *net) +{ + struct nfsd_net *nn = net_generic(net, nfsd_net_id); + + svc_put(nn->nfsd_serv); +} bool i_am_nfsd(void); diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c index 33a80725e14e..1582af33e204 100644 --- a/fs/nfsd/nfssvc.c +++ b/fs/nfsd/nfssvc.c @@ -542,9 +542,14 @@ static struct notifier_block nfsd_inet6addr_notifier = { /* Only used under nfsd_mutex, so this atomic may be overkill: */ static atomic_t nfsd_notifier_refcount = ATOMIC_INIT(0); -static void nfsd_last_thread(struct svc_serv *serv, struct net *net) +static void nfsd_last_thread(struct net *net) { struct nfsd_net *nn = net_generic(net, nfsd_net_id); + struct svc_serv *serv = nn->nfsd_serv; + + spin_lock(&nfsd_notifier_lock); + nn->nfsd_serv = NULL; + spin_unlock(&nfsd_notifier_lock); /* check if the notifier still has clients */ if (atomic_dec_return(&nfsd_notifier_refcount) == 0) { @@ -554,6 +559,8 @@ static void nfsd_last_thread(struct svc_serv *serv, struct net *net) #endif } + svc_xprt_destroy_all(serv, net); + /* * write_ports can create the server without actually starting * any threads--if we get shut down before any threads are @@ -644,7 +651,8 @@ void nfsd_shutdown_threads(struct net *net) svc_get(serv); /* Kill outstanding nfsd threads */ svc_set_num_threads(serv, NULL, 0); - nfsd_put(net); + nfsd_last_thread(net); + svc_put(serv); mutex_unlock(&nfsd_mutex); } @@ -674,9 +682,6 @@ int nfsd_create_serv(struct net *net) serv->sv_maxconn = nn->max_connections; error = svc_bind(serv, net); if (error < 0) { - /* NOT nfsd_put() as notifiers (see below) haven't - * been set up yet. - */ svc_put(serv); return error; } @@ -719,29 +724,6 @@ 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); - - if (kref_put(&nn->nfsd_serv->sv_refcnt, nfsd_noop)) { - svc_xprt_destroy_all(nn->nfsd_serv, net); - nfsd_last_thread(nn->nfsd_serv, net); - svc_destroy(&nn->nfsd_serv->sv_refcnt); - spin_lock(&nfsd_notifier_lock); - nn->nfsd_serv = NULL; - spin_unlock(&nfsd_notifier_lock); - } -} - int nfsd_set_nrthreads(int n, int *nthreads, struct net *net) { int i = 0; @@ -792,7 +774,7 @@ int nfsd_set_nrthreads(int n, int *nthreads, struct net *net) if (err) break; } - nfsd_put(net); + svc_put(nn->nfsd_serv); return err; } @@ -807,6 +789,7 @@ nfsd_svc(int nrservs, struct net *net, const struct cred *cred) int error; bool nfsd_up_before; struct nfsd_net *nn = net_generic(net, nfsd_net_id); + struct svc_serv *serv; mutex_lock(&nfsd_mutex); dprintk("nfsd: creating service\n"); @@ -826,22 +809,25 @@ nfsd_svc(int nrservs, struct net *net, const struct cred *cred) goto out; nfsd_up_before = nn->nfsd_net_up; + serv = nn->nfsd_serv; error = nfsd_startup_net(net, cred); if (error) goto out_put; - error = svc_set_num_threads(nn->nfsd_serv, NULL, nrservs); + error = svc_set_num_threads(serv, NULL, nrservs); if (error) goto out_shutdown; - error = nn->nfsd_serv->sv_nrthreads; + error = serv->sv_nrthreads; + if (error == 0) + nfsd_last_thread(net); 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); + svc_put(serv); + svc_put(serv); out: mutex_unlock(&nfsd_mutex); return error;
Now that the last nfsd thread is stopped by an explicit act of calling svc_set_num_threads() with a count of zero, we only have a limited number of places that can happen, and don't need to call nfsd_last_thread() in nfsd_put() So separate that out and call it at the two places where the number of threads is set to zero. Move the clearing of ->nfsd_serv and the call to svc_xprt_destroy_all() into nfsd_last_thread(), as they are really part of the same action. nfsd_put() is now a thin wrapper around svc_put(), so make it a static inline. nfsd_put() cannot be called after nfsd_last_thread(), so in a couple of places we have to use svc_put() instead. Signed-off-by: NeilBrown <neilb@suse.de> --- fs/nfsd/nfsd.h | 7 ++++++- fs/nfsd/nfssvc.c | 52 ++++++++++++++++++------------------------------ 2 files changed, 25 insertions(+), 34 deletions(-)