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 <bfields@redhat.com>

diff --git a/fs/nfsd/netns.h b/fs/nfsd/netns.h
index ceb413f8fff37d9d26fbbc4a3b30c1559cbd5b12..df4ba4b8b5403e8465ea5a71071b1218bbe874df 100644 (file)
--- 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
index 304a95e4ea6007a221fd7c45df21dda9ce45338c..25910a7d21ccfb78f01dca5eef9f0ad4a9ad0495 100644 (file)
--- 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);