Merge nfsd bugfixes

These are some nfsd bugfixes that I also want in the main branch that
will be submitted for the 5.4 merge window.

Author: J. Bruce Fields

fs/nfsd/nfscache.c

@@ -571,7 +571,7 @@ nfsd_cache_append(struct svc_rqst *rqstp, struct kvec *data)
  */
 static int nfsd_reply_cache_stats_show(struct seq_file *m, void *v)
 {
-	struct nfsd_net *nn = v;
+	struct nfsd_net *nn = m->private;
 
 	seq_printf(m, "max entries:           %u\n", nn->max_drc_entries);
 	seq_printf(m, "num entries:           %u\n",

fs/nfsd/nfsctl.c

@@ -1171,13 +1171,17 @@ static struct inode *nfsd_get_inode(struct super_block *sb, umode_t mode)
 	return inode;
 }
 
-static int __nfsd_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
+static int __nfsd_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode, struct nfsdfs_client *ncl)
 {
 	struct inode *inode;
 
 	inode = nfsd_get_inode(dir->i_sb, mode);
 	if (!inode)
 		return -ENOMEM;
+	if (ncl) {
+		inode->i_private = ncl;
+		kref_get(&ncl->cl_ref);
+	}
 	d_add(dentry, inode);
 	inc_nlink(dir);
 	fsnotify_mkdir(dir, dentry);
@@ -1194,17 +1198,14 @@ static struct dentry *nfsd_mkdir(struct dentry *parent, struct nfsdfs_client *nc
 	dentry = d_alloc_name(parent, name);
 	if (!dentry)
 		goto out_err;
-	ret = __nfsd_mkdir(d_inode(parent), dentry, S_IFDIR | 0600);
+	ret = __nfsd_mkdir(d_inode(parent), dentry, S_IFDIR | 0600, ncl);
 	if (ret)
 		goto out_err;
-	if (ncl) {
-		d_inode(dentry)->i_private = ncl;
-		kref_get(&ncl->cl_ref);
-	}
 out:
 	inode_unlock(dir);
 	return dentry;
 out_err:
+	dput(dentry);
 	dentry = ERR_PTR(ret);
 	goto out;
 }
@@ -1214,11 +1215,9 @@ static void clear_ncl(struct inode *inode)
 	struct nfsdfs_client *ncl = inode->i_private;
 
 	inode->i_private = NULL;
-	synchronize_rcu();
 	kref_put(&ncl->cl_ref, ncl->cl_release);
 }
 
-
 static struct nfsdfs_client *__get_nfsdfs_client(struct inode *inode)
 {
 	struct nfsdfs_client *nc = inode->i_private;
@@ -1232,9 +1231,9 @@ struct nfsdfs_client *get_nfsdfs_client(struct inode *inode)
 {
 	struct nfsdfs_client *nc;
 
-	rcu_read_lock();
+	inode_lock_shared(inode);
 	nc = __get_nfsdfs_client(inode);
-	rcu_read_unlock();
+	inode_unlock_shared(inode);
 	return nc;
 }
 /* from __rpc_unlink */