Commit 713e577d authored by NeilBrown's avatar NeilBrown Committed by Li Lingfeng
Browse files

NFSD: simplify error paths in nfsd_svc() 

stable inclusion
from stable-v6.6.48
commit e0aeb26b04ecd84442d4366fdcc1ed0361f8d36f
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/IAO2E2

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=e0aeb26b04ecd84442d4366fdcc1ed0361f8d36f



--------------------------------

commit bf32075256e9dd9c6b736859e2c5813981339908 upstream.

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.

Signed-off-by: default avatarNeilBrown <neilb@suse.de>
Reviewed-by: default avatarJeff Layton <jlayton@kernel.org>
Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
Reported-by: default avatarLi Lingfeng <lilingfeng3@huawei.com>
Suggested-by: default avatarLi Lingfeng <lilingfeng3@huawei.com>
Tested-by: default avatarLi Lingfeng <lilingfeng3@huawei.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarLi Lingfeng <lilingfeng3@huawei.com>
parent d896aca4

fs/nfsd/nfssvc.c

+4 −10
Original line number Diff line number Diff line
@@ -567,7 +567,6 @@ 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);

}
@@ -783,7 +782,6 @@ 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;
@@ -803,8 +801,6 @@ 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);
@@ -812,17 +808,15 @@ 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);