nfsd: add notifier to handle mount/unmount of rpc_pipefs sb
Jeff Layton [Wed, 21 Mar 2012 13:52:08 +0000 (09:52 -0400)]
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>

fs/nfsd/netns.h
fs/nfsd/nfs4recover.c
fs/nfsd/nfsctl.c

index 12e0cff..66eac33 100644 (file)
@@ -31,4 +31,5 @@ struct nfsd_net {
 };
 
 extern int nfsd_net_id;
+extern struct notifier_block nfsd4_cld_block;
 #endif /* __NFSD_NETNS_H__ */
index cec62ed..6f13281 100644 (file)
@@ -38,6 +38,7 @@
 #include <linux/crypto.h>
 #include <linux/sched.h>
 #include <linux/fs.h>
+#include <linux/module.h>
 #include <net/net_namespace.h>
 #include <linux/sunrpc/rpc_pipe_fs.h>
 #include <linux/sunrpc/clnt.h>
@@ -982,3 +983,46 @@ nfsd4_record_grace_done(struct net *net, time_t boot_time)
        if (client_tracking_ops)
                client_tracking_ops->grace_done(net, boot_time);
 }
+
+static int
+rpc_pipefs_event(struct notifier_block *nb, unsigned long event, void *ptr)
+{
+       struct super_block *sb = ptr;
+       struct net *net = sb->s_fs_info;
+       struct nfsd_net *nn = net_generic(net, nfsd_net_id);
+       struct cld_net *cn = nn->cld_net;
+       struct dentry *dentry;
+       int ret = 0;
+
+       if (!try_module_get(THIS_MODULE))
+               return 0;
+
+       if (!cn) {
+               module_put(THIS_MODULE);
+               return 0;
+       }
+
+       switch (event) {
+       case RPC_PIPEFS_MOUNT:
+               dentry = nfsd4_cld_register_sb(sb, cn->cn_pipe);
+               if (IS_ERR(dentry)) {
+                       ret = PTR_ERR(dentry);
+                       break;
+               }
+               cn->cn_pipe->dentry = dentry;
+               break;
+       case RPC_PIPEFS_UMOUNT:
+               if (cn->cn_pipe->dentry)
+                       nfsd4_cld_unregister_sb(cn->cn_pipe);
+               break;
+       default:
+               ret = -ENOTSUPP;
+               break;
+       }
+       module_put(THIS_MODULE);
+       return ret;
+}
+
+struct notifier_block nfsd4_cld_block = {
+       .notifier_call = rpc_pipefs_event,
+};
index 141197e..dee6c1b 100644 (file)
@@ -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>");