nfsd: add notifier to handle mount/unmount of rpc_pipefs sb

In the event that rpc_pipefs isn't mounted when nfsd starts, we
must register a notifier to handle creating the dentry once it
is mounted, and to remove the dentry on unmount.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

1 files changed, 8 insertions, 1 deletions

diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
index 141197e04703..dee6c1bb9ba8 100644
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -13,6 +13,7 @@
 #include <linux/sunrpc/clnt.h>
 #include <linux/sunrpc/gss_api.h>
 #include <linux/sunrpc/gss_krb5_enctypes.h>
+#include <linux/sunrpc/rpc_pipe_fs.h>
 #include <linux/module.h>
 
 #include "idmap.h"
@@ -1136,9 +1137,12 @@ static int __init init_nfsd(void)
         int retval;
         printk(KERN_INFO "Installing knfsd (copyright (C) 1996 okir@monad.swb.de).\n");
 
+        retval = rpc_pipefs_notifier_register(&nfsd4_cld_block);
+        if (retval)
+                return retval;
         retval = register_pernet_subsys(&nfsd_net_ops);
         if (retval < 0)
-                return retval;
+                goto out_unregister_notifier;
         retval = nfsd4_init_slabs();
         if (retval)
                 goto out_unregister_pernet;
@@ -1181,6 +1185,8 @@ out_free_slabs:
         nfsd4_free_slabs();
 out_unregister_pernet:
         unregister_pernet_subsys(&nfsd_net_ops);
+out_unregister_notifier:
+        rpc_pipefs_notifier_unregister(&nfsd4_cld_block);
         return retval;
 }
 
@@ -1197,6 +1203,7 @@ static void __exit exit_nfsd(void)
         nfsd_fault_inject_cleanup();
         unregister_filesystem(&nfsd_fs_type);
         unregister_pernet_subsys(&nfsd_net_ops);
+        rpc_pipefs_notifier_unregister(&nfsd4_cld_block);
 }
 
 MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");