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>
diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c
index cec62ed..6f13281 100644
--- a/fs/nfsd/nfs4recover.c
+++ b/fs/nfsd/nfs4recover.c
@@ -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 @@
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,
+};
