> On Sep 25, 2023, at 7:41 AM, Jeff Layton <jlayton@xxxxxxxxxx> wrote:
>
> On Mon, 2023-09-25 at 12:06 +1000, NeilBrown wrote:
>> The error paths in nfsd_svc() are needlessly complex and can result in a
>> final call to svc_put() without nfsd_last_thread() being called. This
>> results in the listening sockets not being closed properly.
>>
>> The per-netns setup provided by nfsd_startup_new() and removed by
>> nfsd_shutdown_net() is needed precisely when there are running threads.
>> So we don't need nfsd_up_before. We don't need to know if it *was* up.
>> We only need to know if any threads are left. If none are, then we must
>> call nfsd_shutdown_net(). But we don't need to do that explicitly as
>> nfsd_last_thread() does that for us.
>>
>> So simply call nfsd_last_thread() before the last svc_put() if there are
>> no running threads. That will always do the right thing.
>>
>> Also discard:
>> pr_info("nfsd: last server has exited, flushing export cache\n");
>> It may not be true if an attempt to start the first server failed, and
>> it isn't particularly helpful and it simply reports normal behaviour.
>>
>
> Thanks. Removing that is long overdue.
>
>> Signed-off-by: NeilBrown <neilb@xxxxxxx>
>> ---
>> fs/nfsd/nfssvc.c | 14 ++++----------
>> 1 file changed, 4 insertions(+), 10 deletions(-)
>>
>> diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
>> index c5890cdfe97b..d6122bb2d167 100644
>> --- a/fs/nfsd/nfssvc.c
>> +++ b/fs/nfsd/nfssvc.c
>> @@ -572,7 +572,6 @@ static void nfsd_last_thread(struct net *net)
>> return;
>>
>> nfsd_shutdown_net(net);
>> - pr_info("nfsd: last server has exited, flushing export cache\n");
>> nfsd_export_flush(net);
>> }
>>
>> @@ -786,7 +785,6 @@ int
>> 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;
>>
>> @@ -806,8 +804,6 @@ nfsd_svc(int nrservs, struct net *net, const struct cred *cred)
>> error = nfsd_create_serv(net);
>> if (error)
>> goto out;
>> -
>> - nfsd_up_before = nn->nfsd_net_up;
>> serv = nn->nfsd_serv;
>>
>> error = nfsd_startup_net(net, cred);
>> @@ -815,17 +811,15 @@ nfsd_svc(int nrservs, struct net *net, const struct cred *cred)
>> goto out_put;
>> error = svc_set_num_threads(serv, NULL, nrservs);
>> if (error)
>> - goto out_shutdown;
>> + goto out_put;
>> 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))
>> svc_put(serv);
>> +
>> + if (serv->sv_nrthreads == 0)
>> + nfsd_last_thread(net);
>> svc_put(serv);
>> out:
>> mutex_unlock(&nfsd_mutex);
>
> Nice cleanup.
>
> Reviewed-by: Jeff Layton <jlayton@xxxxxxxxxx>
Applied to nfsd-next.
--
Chuck Lever
