From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752968AbYCJMlf (ORCPT ); Mon, 10 Mar 2008 08:41:35 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750799AbYCJMl1 (ORCPT ); Mon, 10 Mar 2008 08:41:27 -0400 Received: from rv-out-0910.google.com ([209.85.198.190]:35474 "EHLO rv-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751515AbYCJMl0 (ORCPT ); Mon, 10 Mar 2008 08:41:26 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:mime-version:content-type:content-disposition:user-agent; b=aa32zpCOYpNw2TOqZw0/gHpI/r14jrqRlMiE+LuVsMiWAQwuwzBc4R2tOTww9Q5tI1/MOAfXnhNcylrd9Rj4ECQYk8aCQWCt0qBOWDdP3k53e6dbKYy5mDQcnQYL65yPZUOyw+yIznbtB7rlP7Zf/5mhe6LRGiw6KFYYbX6NpPw= Date: Mon, 10 Mar 2008 21:33:43 +0900 From: Akinobu Mita To: linux-kernel@vger.kernel.org Cc: Jens Axboe Subject: [PATCH] block: fix blk_register_queue() return value Message-ID: <20080310123341.GA3351@APFDCB5C> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-2022-jp Content-Disposition: inline User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org blk_register_queue() returns -ENXIO when queue->request_fn is NULL. But there are some block drivers that call blk_register_queue() via add_disk() with queue->request_fn == NULL. (For example, brd, loop) Although no one checks return value of blk_register_queue(), this patch makes it return 0 instead of -ENXIO when queue->request_fn is NULL, Also this patch adds warning when blk_register_queue() and blk_unregister_queue() are called with queue == NULL rather than ignore invalid usage silently. Signed-off-by: Akinobu Mita Cc: Jens Axboe --- block/blk-sysfs.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) Index: 2.6-rc/block/blk-sysfs.c =================================================================== --- 2.6-rc.orig/block/blk-sysfs.c +++ 2.6-rc/block/blk-sysfs.c @@ -276,9 +276,12 @@ int blk_register_queue(struct gendisk *d struct request_queue *q = disk->queue; - if (!q || !q->request_fn) + if (WARN_ON(!q)) return -ENXIO; + if (!q->request_fn) + return 0; + ret = kobject_add(&q->kobj, kobject_get(&disk->dev.kobj), "%s", "queue"); if (ret < 0) @@ -300,7 +303,10 @@ void blk_unregister_queue(struct gendisk { struct request_queue *q = disk->queue; - if (q && q->request_fn) { + if (WARN_ON(!q)) + return; + + if (q->request_fn) { elv_unregister_queue(q); kobject_uevent(&q->kobj, KOBJ_REMOVE);