Commit eda23c3a authored by Trond Myklebust's avatar Trond Myklebust Committed by sanglipeng
Browse files

nfsd: Ensure knfsd shuts down when the "nfsd" pseudofs is unmounted 

stable inclusion
from stable-v5.10.166
commit 032a7d5ff519888f31ea91e24623f7e26befe641
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I7TH9O

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=032a7d5ff519888f31ea91e24623f7e26befe641



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

commit c6c7f2a8 upstream.

In order to ensure that knfsd threads don't linger once the nfsd
pseudofs is unmounted (e.g. when the container is killed) we let
nfsd_umount() shut down those threads and wait for them to exit.

This also should ensure that we don't need to do a kernel mount of
the pseudofs, since the thread lifetime is now limited by the
lifetime of the filesystem.

Signed-off-by: default avatarTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
Signed-off-by: default avatarNikos Tsironis <ntsironis@arrikto.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarsanglipeng <sanglipeng1@jd.com>
parent cf878b2c

fs/nfsd/netns.h

+3 −3
Original line number Diff line number Diff line
@@ -42,9 +42,6 @@ struct nfsd_net { 
	bool grace_ended;

	time64_t boot_time;



	/* internal mount of the "nfsd" pseudofilesystem: */

	struct vfsmount *nfsd_mnt;



	struct dentry *nfsd_client_dir;



	/*
@@ -121,6 +118,9 @@ struct nfsd_net { 
	wait_queue_head_t ntf_wq;

	atomic_t ntf_refcnt;



	/* Allow umount to wait for nfsd state cleanup */

	struct completion nfsd_shutdown_complete;



	/*

	 * clientid and stateid data for construction of net unique COPY

	 * stateids.

fs/nfsd/nfs4state.c

+1 −7
Original line number Diff line number Diff line
@@ -7394,14 +7394,9 @@ nfs4_state_start_net(struct net *net) 
	struct nfsd_net *nn = net_generic(net, nfsd_net_id);

	int ret;



	ret = get_nfsdfs(net);

	if (ret)

		return ret;

	ret = nfs4_state_create_net(net);

	if (ret) {

		mntput(nn->nfsd_mnt);

	if (ret)

		return ret;

	}

	locks_start_grace(net, &nn->nfsd4_manager);

	nfsd4_client_tracking_init(net);

	if (nn->track_reclaim_completes && nn->reclaim_str_hashtbl_size == 0)
@@ -7471,7 +7466,6 @@ nfs4_state_shutdown_net(struct net *net) 


	nfsd4_client_tracking_exit(net);

	nfs4_state_destroy_net(net);

	mntput(nn->nfsd_mnt);

}



void

fs/nfsd/nfsctl.c

+2 −12
Original line number Diff line number Diff line
@@ -1417,6 +1417,8 @@ static void nfsd_umount(struct super_block *sb) 
{

	struct net *net = sb->s_fs_info;



	nfsd_shutdown_threads(net);



	kill_litter_super(sb);

	put_net(net);

}
@@ -1429,18 +1431,6 @@ static struct file_system_type nfsd_fs_type = { 
};

MODULE_ALIAS_FS("nfsd");



int get_nfsdfs(struct net *net)

{

	struct nfsd_net *nn = net_generic(net, nfsd_net_id);

	struct vfsmount *mnt;



	mnt =  vfs_kern_mount(&nfsd_fs_type, SB_KERNMOUNT, "nfsd", NULL);

	if (IS_ERR(mnt))

		return PTR_ERR(mnt);

	nn->nfsd_mnt = mnt;

	return 0;

}



#ifdef CONFIG_PROC_FS

static int create_proc_exports_entry(void)

{

fs/nfsd/nfsd.h

+1 −2
Original line number Diff line number Diff line
@@ -85,13 +85,12 @@ int nfsd_get_nrthreads(int n, int *, struct net *); 
int		nfsd_set_nrthreads(int n, int *, struct net *);

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_destroy(struct net *net);



bool		i_am_nfsd(void);



int get_nfsdfs(struct net *);



struct nfsdfs_client {

	struct kref cl_ref;

	void (*cl_release)(struct kref *kref);

fs/nfsd/nfssvc.c

+34 −1
Original line number Diff line number Diff line
@@ -600,6 +600,37 @@ static const struct svc_serv_ops nfsd_thread_sv_ops = { 
	.svo_module		= THIS_MODULE,

};



static void nfsd_complete_shutdown(struct net *net)

{

	struct nfsd_net *nn = net_generic(net, nfsd_net_id);



	WARN_ON(!mutex_is_locked(&nfsd_mutex));



	nn->nfsd_serv = NULL;

	complete(&nn->nfsd_shutdown_complete);

}



void nfsd_shutdown_threads(struct net *net)

{

	struct nfsd_net *nn = net_generic(net, nfsd_net_id);

	struct svc_serv *serv;



	mutex_lock(&nfsd_mutex);

	serv = nn->nfsd_serv;

	if (serv == NULL) {

		mutex_unlock(&nfsd_mutex);

		return;

	}



	svc_get(serv);

	/* Kill outstanding nfsd threads */

	serv->sv_ops->svo_setup(serv, NULL, 0);

	nfsd_destroy(net);

	mutex_unlock(&nfsd_mutex);

	/* Wait for shutdown of nfsd_serv to complete */

	wait_for_completion(&nn->nfsd_shutdown_complete);

}



bool i_am_nfsd(void)

{

	return kthread_func(current) == nfsd;
@@ -622,11 +653,13 @@ int nfsd_create_serv(struct net *net) 
						&nfsd_thread_sv_ops);

	if (nn->nfsd_serv == NULL)

		return -ENOMEM;

	init_completion(&nn->nfsd_shutdown_complete);



	nn->nfsd_serv->sv_maxconn = nn->max_connections;

	error = svc_bind(nn->nfsd_serv, net);

	if (error < 0) {

		svc_destroy(nn->nfsd_serv);

		nfsd_complete_shutdown(net);

		return error;

	}
@@ -675,7 +708,7 @@ void nfsd_destroy(struct net *net) 
		svc_shutdown_net(nn->nfsd_serv, net);

	svc_destroy(nn->nfsd_serv);

	if (destroy)

		nn->nfsd_serv = NULL;

		nfsd_complete_shutdown(net);

}



int nfsd_set_nrthreads(int n, int *nthreads, struct net *net)