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>
This commit is contained in:
Jeff Layton 2012-03-21 09:52:08 -04:00 committed by J. Bruce Fields
parent f3f8014862
commit 813fd320c1
3 changed files with 53 additions and 1 deletions

View file

@ -31,4 +31,5 @@ struct nfsd_net {
};
extern int nfsd_net_id;
extern struct notifier_block nfsd4_cld_block;
#endif /* __NFSD_NETNS_H__ */

View 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,
};

View 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 @@ static int __init init_nfsd(void)
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>");