[PATCH] kNFSd: nfsd/export.c tidyup and add missing exp_put

There was a missing exp_put in export.c so that after a client
mounts an exported filesystem, the server would never be able to
unmount, even after trying to unexport.  This is fixed by the last
chunk of this patch.

Also assorted cleanups to the code found while hunting.

fs/nfsd/export.c

@@ -175,7 +175,7 @@ int expkey_parse(struct cache_detail *cd, char *mesg, int mlen)
 		ek = svc_expkey_lookup(&key, 2);
 		if (ek)
 			expkey_put(&ek->h, &svc_expkey_cache);
-		svc_export_put(&exp->h, &svc_export_cache);
+		exp_put(exp);
 		err = 0;
 	out_nd:
 		path_release(&nd);
@@ -648,7 +648,6 @@ exp_export(struct nfsctl_export *nxp)
 	struct svc_export	new;
 	struct svc_expkey	*fsid_key = NULL;
 	struct nameidata nd;
-	struct inode	*inode = NULL;
 	int		err;
 
 	/* Consistency check */
@@ -674,7 +673,6 @@ exp_export(struct nfsctl_export *nxp)
 	err = path_lookup(nxp->ex_path, 0, &nd);
 	if (err)
 		goto out_unlock;
-	inode = nd.dentry->d_inode;
 	err = -EINVAL;
 
 	exp = exp_get_by_name(clp, nd.mnt, nd.dentry, NULL);
@@ -687,7 +685,7 @@ exp_export(struct nfsctl_export *nxp)
 	    fsid_key->ek_export != exp)
 		goto finish;
 
-	if (exp != NULL) {
+	if (exp) {
 		/* just a flags/id/fsid update */
 
 		exp_fsid_unhash(exp);
@@ -700,7 +698,7 @@ exp_export(struct nfsctl_export *nxp)
 		goto finish;
 	}
 
-	err = check_export(inode, nxp->ex_flags);
+	err = check_export(nd.dentry->d_inode, nxp->ex_flags);
 	if (err) goto finish;
 
 	err = -ENOMEM;
@@ -838,7 +836,7 @@ exp_rootfh(svc_client *clp, char *path, struct knfsd_fh *f, int maxsize)
 		err = 0;
 	memcpy(f, &fh.fh_handle, sizeof(struct knfsd_fh));
 	fh_put(&fh);
-
+	exp_put(exp);
 out:
 	path_release(&nd);
 	return err;