dlm: convert to idr_alloc()

Convert to the much saner new idr interface. Error return values from
recover_idr_add() mix -1 and -errno. The conversion doesn't change
that but it looks iffy.

Signed-off-by: Tejun Heo <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

fs/dlm/lock.c

···
 static int create_lkb(struct dlm_ls *ls, struct dlm_lkb **lkb_ret)
 {
 	struct dlm_lkb *lkb;
-	int rv, id;
+	int rv;
 
 	lkb = dlm_allocate_lkb(ls);
 	if (!lkb)
···
 	mutex_init(&lkb->lkb_cb_mutex);
 	INIT_WORK(&lkb->lkb_cb_work, dlm_callback_work);
 
- retry:
-	rv = idr_pre_get(&ls->ls_lkbidr, GFP_NOFS);
-	if (!rv)
-		return -ENOMEM;
-
+	idr_preload(GFP_NOFS);
 	spin_lock(&ls->ls_lkbidr_spin);
-	rv = idr_get_new_above(&ls->ls_lkbidr, lkb, 1, &id);
-	if (!rv)
-		lkb->lkb_id = id;
+	rv = idr_alloc(&ls->ls_lkbidr, lkb, 1, 0, GFP_NOWAIT);
+	if (rv >= 0)
+		lkb->lkb_id = rv;
 	spin_unlock(&ls->ls_lkbidr_spin);
-
-	if (rv == -EAGAIN)
-		goto retry;
+	idr_preload_end();
 
 	if (rv < 0) {
 		log_error(ls, "create_lkb idr error %d", rv);

fs/dlm/recover.c

···
 static int recover_idr_add(struct dlm_rsb *r)
 {
 	struct dlm_ls *ls = r->res_ls;
-	int rv, id;
+	int rv;
 
-	rv = idr_pre_get(&ls->ls_recover_idr, GFP_NOFS);
-	if (!rv)
-		return -ENOMEM;
-
+	idr_preload(GFP_NOFS);
 	spin_lock(&ls->ls_recover_idr_lock);
 	if (r->res_id) {
-		spin_unlock(&ls->ls_recover_idr_lock);
-		return -1;
+		rv = -1;
+		goto out_unlock;
 	}
-	rv = idr_get_new_above(&ls->ls_recover_idr, r, 1, &id);
-	if (rv) {
-		spin_unlock(&ls->ls_recover_idr_lock);
-		return rv;
-	}
-	r->res_id = id;
+	rv = idr_alloc(&ls->ls_recover_idr, r, 1, 0, GFP_NOWAIT);
+	if (rv < 0)
+		goto out_unlock;
+
+	r->res_id = rv;
 	ls->ls_recover_list_count++;
 	dlm_hold_rsb(r);
+	rv = 0;
+out_unlock:
 	spin_unlock(&ls->ls_recover_idr_lock);
-	return 0;
+	idr_preload_end();
+	return rv;
 }
 
 static void recover_idr_del(struct dlm_rsb *r)