From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bmailout1.hostsharing.net (bmailout1.hostsharing.net [83.223.95.100]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 64A751754F; Tue, 13 Feb 2024 06:32:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=83.223.95.100 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707805949; cv=none; b=ulGxCyCJHSBpE44zPejqKDqF8pODF+WaXhrN3wMxRf3EdyMAX66RpKLZG8ETKHFNRsMZB4y4M2Hj+ANVaf6l77VYl4nVPu7PX565ie299bNtkgfdBFgiMwp9DBRa0PlBwZg4yw1D6JxhlGsMcJ5bdMGAHd6mDLaV++1RU5zkKt8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707805949; c=relaxed/simple; bh=/b2W5dfca36Y/WDoeFmMMfgnTkRpcuKoJ9AScS+hT74=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=AH5qQNg2iynJ5EHEn97Cark1LJb7dVvX/80BIVyB5+Uq0prcJojeRv/wGQ6HL+MV8dYQL0LpaGePVhr0RG7barrwqjNlO2HkhJKO9qoFgheulnWGRI07PdK4jxREQI9EQDQsor7qCnyDgcA0QJqZlbMy/JMmUe+8pnUr1ATXOLA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=wunner.de; spf=none smtp.mailfrom=h08.hostsharing.net; arc=none smtp.client-ip=83.223.95.100 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=wunner.de Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=h08.hostsharing.net Received: from h08.hostsharing.net (h08.hostsharing.net [83.223.95.28]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "*.hostsharing.net", Issuer "RapidSSL TLS RSA CA G1" (verified OK)) by bmailout1.hostsharing.net (Postfix) with ESMTPS id 994DB3000086B; Tue, 13 Feb 2024 07:32:26 +0100 (CET) Received: by h08.hostsharing.net (Postfix, from userid 100393) id 8330C70EB7; Tue, 13 Feb 2024 07:32:26 +0100 (CET) Date: Tue, 13 Feb 2024 07:32:26 +0100 From: Lukas Wunner To: Mathieu Desnoyers Cc: Dan Williams , Arnd Bergmann , Dave Chinner , linux-kernel@vger.kernel.org, Andrew Morton , Linus Torvalds , Vishal Verma , Dave Jiang , Matthew Wilcox , Russell King , linux-arch@vger.kernel.org, linux-cxl@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-xfs@vger.kernel.org, dm-devel@lists.linux.dev, nvdimm@lists.linux.dev, linux-s390@vger.kernel.org Subject: Re: [PATCH v5 1/8] dax: alloc_dax() return ERR_PTR(-EOPNOTSUPP) for CONFIG_DAX=n Message-ID: <20240213063226.GA4740@wunner.de> References: <20240212163101.19614-1-mathieu.desnoyers@efficios.com> <20240212163101.19614-2-mathieu.desnoyers@efficios.com> Precedence: bulk X-Mailing-List: linux-xfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240212163101.19614-2-mathieu.desnoyers@efficios.com> User-Agent: Mutt/1.10.1 (2018-07-13) On Mon, Feb 12, 2024 at 11:30:54AM -0500, Mathieu Desnoyers wrote: > Change the return value from NULL to PTR_ERR(-EOPNOTSUPP) for > CONFIG_DAX=n to be consistent with the fact that CONFIG_DAX=y > never returns NULL. All the callers of alloc_dax() only check for IS_ERR(). Doesn't this result in a change of behavior in all the callers? Previously they'd ignore the NULL return value and continue, now they'll error out. Given that, seems dangerous to add a Fixes tag with a v4.0 commit and thus risk regressing all stable kernels. Thanks, Lukas