From: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
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@xxxxxxxxxxxxxxx>
---
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 c330f5bd0cf3..a75abeb1e698 100644
--- a/fs/nfsd/netns.h
+++ b/fs/nfsd/netns.h
@@ -51,9 +51,6 @@ 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;
/*
@@ -130,6 +127,9 @@ 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 423fd6683f3a..8bf840661d67 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -7346,14 +7346,9 @@ 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)
@@ -7423,7 +7418,6 @@ 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 ef86ed23af82..02ff7f762e2d 100644
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -1416,6 +1416,8 @@ 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);
}
@@ -1428,18 +1430,6 @@ 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 8bdc37aa2c2e..27c1308ffc2b 100644
--- a/fs/nfsd/nfsd.h
+++ b/fs/nfsd/nfsd.h
@@ -93,13 +93,12 @@ 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);
diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
index 6de406322106..f014b7aa0726 100644
--- a/fs/nfsd/nfssvc.c
+++ b/fs/nfsd/nfssvc.c
@@ -596,6 +596,37 @@ 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;
@@ -618,11 +649,13 @@ 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;
}
@@ -671,7 +704,7 @@ 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)
--
2.30.2
