From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2F02CC61D92 for ; Wed, 22 Nov 2023 07:29:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234911AbjKVH3E (ORCPT ); Wed, 22 Nov 2023 02:29:04 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51198 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230062AbjKVH3D (ORCPT ); Wed, 22 Nov 2023 02:29:03 -0500 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:3::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9F469D1; Tue, 21 Nov 2023 23:28:59 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=xKzadQBp86OPkvjkpX1NPj8LtoV9+7VhbqtkMJ7c0p8=; b=R6YRWtxaLw6jG2S3GfiNe5UL1W 19YrMm3BTQIFpje67cz9XGp2xu4KuwhFCVHLKcNW2+0JoczOf/E8SKNVh5osjmP34/iXSvALyTC82 OkXvMx5oCWyGdg8JPzbGfB40hjvB7m0gJNPgFMzY2VlSP8ZC2B4eY2V3vD1lJMrNl2qR1juBD73Si cNtjziHq1vutkQd2+v0taG733jkz2D8q7Et5FUwa0YdwWe1ASzGoVkn2/7j0YcVA/JQJfSwGHWamy qhtwVIRX6jaRKN0iZ/3Obpbc+oS9n3xHzMp3jmHjRQJQQ0QIS5wZEoOjF5+X78OgOHMDwIdUIT752 eZZU8d+A==; Received: from hch by bombadil.infradead.org with local (Exim 4.96 #2 (Red Hat Linux)) id 1r5hfM-000uPI-0t; Wed, 22 Nov 2023 07:28:56 +0000 Date: Tue, 21 Nov 2023 23:28:56 -0800 From: Christoph Hellwig To: Yu Kuai Cc: ming.lei@redhat.com, axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, yukuai3@huawei.com, yi.zhang@huawei.com, yangerkun@huawei.com Subject: Re: [PATCH v3 2/3] block: introduce new field bd_flags in block_device Message-ID: References: <20231122103103.1104589-1-yukuai1@huaweicloud.com> <20231122103103.1104589-3-yukuai1@huaweicloud.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20231122103103.1104589-3-yukuai1@huaweicloud.com> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > + if (partno && bdev_flagged(disk->part0, BD_FLAG_HAS_SUBMIT_BIO)) > + bdev_set_flag(bdev, BD_FLAG_HAS_SUBMIT_BIO); > else > + bdev_clear_flag(bdev, BD_FLAG_HAS_SUBMIT_BIO); While the block layer has a bit of history of using wrappers for testing, setting and clearing flags, I have to say I always find them rather confusing when reading the code. > +#define BD_FLAG_READ_ONLY 0 /* read-only-policy */ I know this is copied from the existing field, but can you expand it a bit? > +#define BD_FLAG_WRITE_HOLDER 1 > +#define BD_FLAG_HAS_SUBMIT_BIO 2 > +#define BD_FLAG_MAKE_IT_FAIL 3 And also write comments for these. > + > struct block_device { > sector_t bd_start_sect; > sector_t bd_nr_sectors; > @@ -44,10 +49,8 @@ struct block_device { > struct request_queue * bd_queue; > struct disk_stats __percpu *bd_stats; > unsigned long bd_stamp; > - bool bd_read_only; /* read-only policy */ > + unsigned short bd_flags; I suspect you really need an unsigned long and atomic bit ops here. Even a lock would probably not work on alpha as it could affect the other fields in the same 32-bit alignment.