6.1-stable review patch. If anyone has any objections, please let me know.
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From: NeilBrown neilb@suse.de
[ Upstream commit 9f28a971ee9fdf1bf8ce8c88b103f483be610277 ]
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 Signed-off-by: Chuck Lever chuck.lever@oracle.com Stable-dep-of: 2a501f55cd64 ("nfsd: call nfsd_last_thread() before final nfsd_put()") Signed-off-by: Sasha Levin sashal@kernel.org --- 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 09726c5b9a317..fddd70372e4cb 100644 --- a/fs/nfsd/nfsd.h +++ b/fs/nfsd/nfsd.h @@ -97,7 +97,12 @@ 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 f6cc99af81925..6ac18399fed2b 100644 --- a/fs/nfsd/nfssvc.c +++ b/fs/nfsd/nfssvc.c @@ -523,9 +523,14 @@ 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) { @@ -535,6 +540,8 @@ 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 @@ -625,7 +632,8 @@ 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); }
@@ -655,9 +663,6 @@ 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; } @@ -700,29 +705,6 @@ 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; @@ -773,7 +755,7 @@ int nfsd_set_nrthreads(int n, int *nthreads, struct net *net) if (err) break; } - nfsd_put(net); + svc_put(nn->nfsd_serv); return err; }
@@ -788,6 +770,7 @@ 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"); @@ -807,22 +790,25 @@ 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;