From: Trond Myklebust trond.myklebust@hammerspace.com

commit c6c7f2a84da459bcc3714044e74a9cb66de31039 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: Trond Myklebust trond.myklebust@hammerspace.com Signed-off-by: Chuck Lever chuck.lever@oracle.com Signed-off-by: Nikos Tsironis ntsironis@arrikto.com --- fs/nfsd/netns.h | 6 +++--- fs/nfsd/nfs4state.c | 8 +------- fs/nfsd/nfsctl.c | 14 ++------------ fs/nfsd/nfsd.h | 3 +-- fs/nfsd/nfssvc.c | 35 ++++++++++++++++++++++++++++++++++- 5 files changed, 41 insertions(+), 25 deletions(-)

diff --git a/fs/nfsd/netns.h b/fs/nfsd/netns.h index ed53e206a299..82329b5102c6 100644 --- a/fs/nfsd/netns.h +++ b/fs/nfsd/netns.h @@ -42,9 +42,6 @@ struct nfsd_net { bool grace_ended; time_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. diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index de2c3809d15a..5922eceb0176 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -7754,14 +7754,9 @@ 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) @@ -7830,7 +7825,6 @@ nfs4_state_shutdown_net(struct net *net)

nfsd4_client_tracking_exit(net); nfs4_state_destroy_net(net); - mntput(nn->nfsd_mnt); }

void diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c index 055cc0458f27..a2454739b1cf 100644 --- a/fs/nfsd/nfsctl.c +++ b/fs/nfsd/nfsctl.c @@ -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) { diff --git a/fs/nfsd/nfsd.h b/fs/nfsd/nfsd.h index 4ff0c5318a02..3ae9811c0bb9 100644 --- a/fs/nfsd/nfsd.h +++ b/fs/nfsd/nfsd.h @@ -84,11 +84,10 @@ 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);

-int get_nfsdfs(struct net *); - struct nfsdfs_client { struct kref cl_ref; void (*cl_release)(struct kref *kref); diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c index 70684c7ae94b..969a227186fa 100644 --- a/fs/nfsd/nfssvc.c +++ b/fs/nfsd/nfssvc.c @@ -594,6 +594,37 @@ 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); +} + int nfsd_create_serv(struct net *net) { int error; @@ -611,11 +642,13 @@ 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; }

@@ -664,7 +697,7 @@ 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)