From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752822Ab1JZUdS (ORCPT ); Wed, 26 Oct 2011 16:33:18 -0400 Received: from mail-pz0-f42.google.com ([209.85.210.42]:40588 "EHLO mail-pz0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752146Ab1JZUdR (ORCPT ); Wed, 26 Oct 2011 16:33:17 -0400 Date: Wed, 26 Oct 2011 13:33:11 -0700 From: Tejun Heo To: akpm@linux-foundation.org Cc: linux-kernel@vger.kernel.org, rusty@rustcorp.com.au Subject: [PATCH] ida: make ida_simple_get/put() IRQ safe Message-ID: <20111026203311.GF24261@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org It's often convenient to be able to release resource from IRQ context. Make ida_simple_*() use irqsave/restore spin ops so that they are IRQ safe. Signed-off-by: Tejun Heo Acked-by: Rusty Russell --- Andrew, can you please route this through mm? Thank you. lib/idr.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) Index: work/lib/idr.c =================================================================== --- work.orig/lib/idr.c +++ work/lib/idr.c @@ -944,6 +944,7 @@ int ida_simple_get(struct ida *ida, unsi { int ret, id; unsigned int max; + unsigned long flags; BUG_ON((int)start < 0); BUG_ON((int)end < 0); @@ -959,7 +960,7 @@ again: if (!ida_pre_get(ida, gfp_mask)) return -ENOMEM; - spin_lock(&simple_ida_lock); + spin_lock_irqsave(&simple_ida_lock, flags); ret = ida_get_new_above(ida, start, &id); if (!ret) { if (id > max) { @@ -969,7 +970,7 @@ again: ret = id; } } - spin_unlock(&simple_ida_lock); + spin_unlock_irqrestore(&simple_ida_lock, flags); if (unlikely(ret == -EAGAIN)) goto again; @@ -985,10 +986,12 @@ EXPORT_SYMBOL(ida_simple_get); */ void ida_simple_remove(struct ida *ida, unsigned int id) { + unsigned long flags; + BUG_ON((int)id < 0); - spin_lock(&simple_ida_lock); + spin_lock_irqsave(&simple_ida_lock, flags); ida_remove(ida, id); - spin_unlock(&simple_ida_lock); + spin_unlock_irqrestore(&simple_ida_lock, flags); } EXPORT_SYMBOL(ida_simple_remove);