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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 9CC8AE7719C for ; Fri, 10 Jan 2025 09:19:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=HM59L0LqLr8BY+Ah3bEi1w8vlkuX/M02gI8v5b6K9Xc=; b=QOu8syZo5/zQ9zcIDVbh/VKFj5 ApNnvhBpjfcC/ZxFwJeP9+jngtgRtfbFGki0HzEjSnAP+RBRPDEpYUrR3JIlAm9mEkkG42G52fLLM InB8mIbhXPfpi52KZOurbG61qUzJttdcDPmOJ4/gtigEFsFR0o+2RMzVdvinbRI17z1iekpX2N+Ww DqGL8WF+thMnSeT5MD0TxMAYvMJi+SctClGS7RxwUs6f+ek/VC9v7OxVh9GvSDk+cz4uKQso/eYVV 4MjeKo1yVWeC8jwlkRNgcOgiKOfye5MgtrBAuDABhZcsfIb+K7vgmAi1lgt2e/7J5s4bZ1gHqkAYh D4moRN/A==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tWBAj-0000000EfOb-17H6; Fri, 10 Jan 2025 09:19:17 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tWBAd-0000000EfMY-1quw for linux-nvme@lists.infradead.org; Fri, 10 Jan 2025 09:19:13 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 2C6A268BFE; Fri, 10 Jan 2025 10:19:00 +0100 (CET) Date: Fri, 10 Jan 2025 10:18:59 +0100 From: Christoph Hellwig To: John Garry Cc: Christoph Hellwig , Jens Axboe , Damien Le Moal , Ming Lei , Nilay Shroff , linux-block@vger.kernel.org, linux-nvme@lists.infradead.org, nbd@other.debian.org, linux-scsi@vger.kernel.org, usb-storage@lists.one-eyed-alien.net, "Martin K . Petersen" , Johannes Thumshirn Subject: Re: [PATCH 05/11] block: add a store_limit operations for sysfs entries Message-ID: <20250110091859.GA8373@lst.de> References: <20250110054726.1499538-1-hch@lst.de> <20250110054726.1499538-6-hch@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250110_011911_623019_8EAACA98 X-CRM114-Status: GOOD ( 15.23 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Fri, Jan 10, 2025 at 09:15:09AM +0000, John Garry wrote: >> + int (*store_limit)(struct gendisk *disk, const char *page, > > I don't really see why this returns an int, while the queue features > callback methods return a ssize_t. I know that the res variable in > queue_attr_store() gets mixed with an int for updating the queue limits, > but I don't see that as a reason to use int here. The normal store methods have the annoying calling convention where they return the parsed string length on success. ->store_limits uses the simpler and harder to get wrong convention of returning 0 on success.