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 94E4917A318; Tue, 7 Oct 2025 04:40:03 +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=1759812004; cv=none; b=POiWskv4eXz1b+Z/Uqxn0Twn2TVY7chq8b+bYhuhoxb0PKKhaXcDYm9JGySDhsWjWH4F/PrkX9+kTWUqRNkakHUuIKr3ERguYhHZX+jW0tPpF0lXsZe7Qb7EO4d9W+g3eXGWsxSxHB5IKB2HrLyYxnjFBUTxTqdSWo95ghYf+3s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759812004; c=relaxed/simple; bh=GeYSyG5ulRONz/Oh78xBkkMNZYojc/GpUceMuyVQSas=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=dJVgyujYdrSMFpVch+0Gdy/XoS/tyG93dmDG5tbS88EEyrBWRtHdZjJ6lF3q6GgE3L1ORVAvYnzrwDP3KldfCjMM9+UoA/0+0lM5cZu0fjcicB1gh0fMvuBEkiNnitOu6JsEiQ0hzJygfJ/L3L7+SfoC1K+jEopzwqU607CplwY= 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=KvvUcnsC; 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="KvvUcnsC" 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=+AguE4rucpaLg7FRf0dthwiLawI0yG7ImPAcuMa5Ft0=; b=KvvUcnsCCswrLRbrDcoRJmfHPB JJyHOcyzAWpyqdIoBTqJ/gVWCj9Ch9KAaFgb8NA2zaRHVyaFOpl4jTio9nzGpuWQyiPBGPglHSJXQ iqZ1S1Ku1o0XeJ5pH+8QOmpWSIslnvMCu0D1U+kxkqljO/t8MKlqljoZrYTT52qCP2///yKhIqCco NKRU42bkstpeUXRXiTSBzM6LAw2cgtMcfruEgoHTGu7QJtyEWFMZ/yRXU7P6Bx5Ywdc4TprN6NEk3 6wFs3pB/B6Lek1COjRb9hkkN8IvqGhfE5gdpU0SVvvQ8e2W4JgezRDiARn/DBBcJ6rBDqOJcFL+9y NwTkgIag==; Received: from hch by bombadil.infradead.org with local (Exim 4.98.2 #2 (Red Hat Linux)) id 1v5zUZ-00000001GFd-0Y2k; Tue, 07 Oct 2025 04:40:03 +0000 Date: Mon, 6 Oct 2025 21:40:03 -0700 From: Christoph Hellwig To: dima@arista.com Cc: Nathan Chancellor , Nicolas Schier , linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, David Disseldorp , Nicolas Schier Subject: Re: [PATCH RFC] gen_init_cpio: Do fsync() only on regular files Message-ID: References: <20251007-gen_init_cpio-pipe-v1-1-d782674d4926@arista.com> Precedence: bulk X-Mailing-List: linux-kbuild@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: <20251007-gen_init_cpio-pipe-v1-1-d782674d4926@arista.com> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html On Tue, Oct 07, 2025 at 12:55:03AM +0100, Dmitry Safonov via B4 Relay wrote: > From: Dmitry Safonov > > Here at Arista gen_init_cpio is used in testing in order to create > an initramfs for specific tests. Most notably, there is a test that does > essentially a fork-bomb in kdump/panic kernel, replacing build-time > generated init script: instead of doing makedumpfile, it does call > shell tests. Why is is using fsync at all? Seems like this was added in commit ae18b94099b04264b32e33b057114024bc72c993 Author: David Disseldorp Date: Tue Aug 19 13:05:45 2025 +1000 gen_init_cpio: support -o parameter without any good explanation. In general doing a per-file fsync is going to horrible wreck performance, and given that no one is interested in partial initramfs archives also rather pointless.