nfsd: persist nfsd filesystem across mounts

Keep around one internal mount of the nfsd filesystem so that we can add stuff to it when clients come and go, regardless of whether anyone has it mounted. Signed-off-by: J. Bruce Fields <[email protected]>
jaseg · Jul 3, 2019 · 2c830dd · 2c830dd
1 parent 855c9e7
commit 2c830dd
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diff --git a/fs/nfsd/netns.h b/fs/nfsd/netns.h
@@ -42,6 +42,9 @@ struct nfsd_net {
 	bool grace_ended;
 	time_t boot_time;
 
+	/* internal mount of the "nfsd" pseudofilesystem: */
+	struct vfsmount *nfsd_mnt;
+
 	/*
 	 * reclaim_str_hashtbl[] holds known client info from previous reset/reboot
 	 * used in reboot/reset lease grace period processing

diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
@@ -1232,6 +1232,7 @@ unsigned int nfsd_net_id;
 static __net_init int nfsd_init_net(struct net *net)
 {
 	int retval;
+	struct vfsmount *mnt;
 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 
 	retval = nfsd_export_init(net);
@@ -1255,8 +1256,17 @@ static __net_init int nfsd_init_net(struct net *net)
 
 	atomic_set(&nn->ntf_refcnt, 0);
 	init_waitqueue_head(&nn->ntf_wq);
+
+	mnt =  vfs_kern_mount(&nfsd_fs_type, SB_KERNMOUNT, "nfsd", NULL);
+	if (IS_ERR(mnt)) {
+		retval = PTR_ERR(mnt);
+		goto out_mount_err;
+	}
+	nn->nfsd_mnt = mnt;
 	return 0;
 
+out_mount_err:
+	nfsd_reply_cache_shutdown(nn);
 out_drc_error:
 	nfsd_idmap_shutdown(net);
 out_idmap_error:
@@ -1269,6 +1279,7 @@ static __net_exit void nfsd_exit_net(struct net *net)
 {
 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 
+	mntput(nn->nfsd_mnt);
 	nfsd_reply_cache_shutdown(nn);
 	nfsd_idmap_shutdown(net);
 	nfsd_export_shutdown(net);