From mboxrd@z Thu Jan 1 00:00:00 1970 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.subspace.kernel.org (Postfix) with ESMTPS id 6448C13665B; Mon, 6 Jan 2025 18:06:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736186800; cv=none; b=k3Uxar+zBJhbgC4UYc1NucumTe8/GAjhfbkTPauZZz/YVQhYspo+xPb3ZKYzHElXuZ/1tuDxrX4Vo5+uefH9PeYgkC0m/7GBINvsUdss5ZMuTL0jOSWa7Dq14SXht7JcDMKGd5fYwHD53bp8BJ9LXQaYd0TdN1fzQuwJE1h3lDg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736186800; c=relaxed/simple; bh=Is5mI3NZ7iUvYxbFNyrMCBtqp8Tq7tlQP0/chDnHOuo=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=r/naW8nzYX9iJv9wAcxI55v4owAntSvjDtkIvbadq8nuxxB8HrtrA9IB7sOq4dfHozkSWzT94y0AYDOhtdiy2mINJsAg9VXqaI3ApHKlHyu2+EOK0yGhpsRKo4Dt0qlr+pndBLqiRYKgnHu4kVr76r3Lvzb77Sepl1om63AaJMg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=qUxY46Ks; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="qUxY46Ks" 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=Is5mI3NZ7iUvYxbFNyrMCBtqp8Tq7tlQP0/chDnHOuo=; b=qUxY46Ksvs1yZZYTqfSx7aqs2i md/g1C/Fu+xkT+Ndw/T5hwQaas0fu77v6n0rVYtTIi2gkjmOc1BO6gvT5qaV6+tWdjeCm6L2FtlBH Dec8pkVLtp6P3WQ41ushZLKgLbMQ30W2HXjz+67JQt9oJqEsHputXmrhYEyOSn2tlNvnRpSnyCAoP Lcujubqykd9KWo04dmG2qpg+ubt+ir0w6CLJynfdd5QKUXuw1ptnNGguVa6TQ4mAGaBlAy4XYrAPP tBvcZuDvKnVJztHPb+bkHnUj4SgfH9Ok6Rq18YE+5AJVNxuAOXgFqFj8KX3igTShtKUIW+7NcS9wC o3vZWJig==; Received: from hch by bombadil.infradead.org with local (Exim 4.98 #2 (Red Hat Linux)) id 1tUrUo-00000002Dnl-16CR; Mon, 06 Jan 2025 18:06:34 +0000 Date: Mon, 6 Jan 2025 10:06:34 -0800 From: Christoph Hellwig To: "Darrick J. Wong" Cc: Christoph Hellwig , Theodore Ts'o , Zhang Yi , linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk, brauner@kernel.org, jack@suse.cz, adilger.kernel@dilger.ca, yi.zhang@huawei.com, chengzhihao1@huawei.com, yukuai3@huawei.com, yangerkun@huawei.com, Sai Chaitanya Mitta , linux-xfs@vger.kernel.org Subject: Re: [RFC PATCH 1/2] fs: introduce FALLOC_FL_FORCE_ZERO to fallocate Message-ID: References: <20241228014522.2395187-1-yi.zhang@huaweicloud.com> <20241228014522.2395187-2-yi.zhang@huaweicloud.com> <20250106161732.GG1284777@mit.edu> <20250106173133.GB6174@frogsfrogsfrogs> Precedence: bulk X-Mailing-List: linux-ext4@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: <20250106173133.GB6174@frogsfrogsfrogs> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html On Mon, Jan 06, 2025 at 09:31:33AM -0800, Darrick J. Wong wrote: > I think we should wire it up as a new FALLOC_FL_WRITE_ZEROES mode, > document very vigorously that it exists to facilitate pure overwrites > (specifically that it returns EOPNOTSUPP for always-cow files), and not > add more ioctls. That goes into a similar direction to what I'd prefer. > (That said, doesn't BLKZEROOUT already do this for bdevs?) Yes. But the same is true for the other fallocate modes on block devices.