From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mp11.migadu.com ([2001:41d0:2:4a6f::]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) by ms5.migadu.com with LMTPS id sD0lC1Ixm2JsGAEAbAwnHQ (envelope-from ) for ; Sat, 04 Jun 2022 12:17:54 +0200 Received: from aspmx1.migadu.com ([2001:41d0:2:4a6f::]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) by mp11.migadu.com with LMTPS id ePg4C1Ixm2I+hgAA9RJhRA (envelope-from ) for ; Sat, 04 Jun 2022 12:17:54 +0200 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by aspmx1.migadu.com (Postfix) with ESMTPS id D02C4172A7 for ; Sat, 4 Jun 2022 12:17:53 +0200 (CEST) Received: from localhost ([::1]:37224 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nxQqu-0003k5-SL for larch@yhetil.org; Sat, 04 Jun 2022 06:17:52 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:49620) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nxQqh-0003jw-6C for guix-devel@gnu.org; Sat, 04 Jun 2022 06:17:39 -0400 Received: from laurent.telenet-ops.be ([2a02:1800:110:4::f00:19]:46082) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1nxQqf-0000b1-6Y for guix-devel@gnu.org; Sat, 04 Jun 2022 06:17:38 -0400 Received: from [172.20.10.5] ([188.189.178.99]) by laurent.telenet-ops.be with bizsmtp id eyHX2700B293nKQ01yHYwU; Sat, 04 Jun 2022 12:17:33 +0200 Message-ID: <575169004eeb5bc037c306bca4954438536ebc22.camel@telenet.be> Subject: Re: Move switch-symlinks to (guix build utils) From: Maxime Devos To: bokr@bokr.com, Ludovic =?ISO-8859-1?Q?Court=E8s?= Cc: Arun Isaac , Guix Devel Date: Sat, 04 Jun 2022 12:17:26 +0200 In-Reply-To: <20220603235505.GA2742@LionPure> References: <87pmjsdeh7.fsf@systemreboot.net> <72a63d9badd632af81adb75b66cd95d9c05bc31a.camel@telenet.be> <87ee07cdfn.fsf@systemreboot.net> <8735glk8gs.fsf@gnu.org> <2c194c3b2f192ba49caaf585703f95b6c6bcb7d9.camel@telenet.be> <87h751ily8.fsf@gnu.org> <20220603235505.GA2742@LionPure> Content-Type: multipart/signed; micalg="pgp-sha512"; protocol="application/pgp-signature"; boundary="=-pjtYqEkXAZcevfy31WxF" User-Agent: Evolution 3.38.3-1 MIME-Version: 1.0 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=telenet.be; s=r22; t=1654337853; bh=3jxT2YDuKtmUArmXVek61Mh51FbJEamTxDj4Yu6S/n8=; h=Subject:From:To:Cc:Date:In-Reply-To:References; b=i2Djyvipc7ext3SFxzyoevN2JLw8KPPb8/qB7hC2KXfcMbWtdElPzPyeGqrozT7bY 4EQYOWebhfFVcP/8hq+Ir4S4A2V1dhk+phj1nnen4MRz7SPknRZxVMlkJmX7JYl1XD APfBzuFXzx2BbUvhRqywVVTTWvAiYesccwE/LRqfotoY6rSRnAXX1CmVQwC3cTAu6r 06okM29YVlOF7q6ZJZ3oMGgU3VBvpn+g2QNuyZ//IISbEMNJMFXeXklbTkoaNLDItQ I76eESzwHhNnL8CG6PsM9/S/HuR/relEsHqBgqVaAmrOjuj9/FNtyChX3Wayky6GIc oLMsWEL1ua4nA== Received-SPF: pass client-ip=2a02:1800:110:4::f00:19; envelope-from=maximedevos@telenet.be; helo=laurent.telenet-ops.be X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_LOW=-0.7, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: guix-devel@gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "Development of GNU Guix and the GNU System distribution." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: guix-devel-bounces+larch=yhetil.org@gnu.org Sender: "Guix-devel" X-Migadu-Flow: FLOW_IN X-Migadu-To: larch@yhetil.org X-Migadu-Country: US ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=yhetil.org; s=key1; t=1654337873; h=from:from:sender:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:in-reply-to:in-reply-to: references:references:list-id:list-help:list-unsubscribe: list-subscribe:list-post:dkim-signature; bh=3jxT2YDuKtmUArmXVek61Mh51FbJEamTxDj4Yu6S/n8=; b=nFZHdG1oM+GNbJt0QqFdvzIbe35c52eAbtMsoVR6saz60Nlc98rBQs0pqesugu8boJ9VTN /cG+ahtWKPqu6CJHG8lk/mH3QRnjbtDQgOAx89f/XIGDk+v9o8Op5e31RwE6AtKBJDzrhH esuKf6iEYkzfZoB7LyNVq8jBwS8gbCA3x8UMGyu4jdvMCujtYZ56DVl1J2n2etaxeqGJ4y 2W7RB7W5q/Dbm6DQWcq7a/o0XwQAiyvmqzLFwN3oUIFvbfR+W8k4PyVjkmJy7XV0IieSr4 hPLs+2rbpQbMgTok3PEGkz3FwzkaC4j/z0NnK5My1UBokrzueKLOgDLlMZ/JNQ== ARC-Seal: i=1; s=key1; d=yhetil.org; t=1654337873; a=rsa-sha256; cv=none; b=ns2o6Vou1t0vbrVcvsBCFjiB4RrPIdoTWgmfcIWYkFpZULMxHV3nKZWLf408GRgaolB1Ll DTV4V1yhhd3GEIPlF35Vquj0PP+Hy3FDlnGu/g4gLdB9PaO57QcKf8lGcfyM+wzPpNrqQJ 8E5UzROBARUOqIeqXVt2CPrYOHkfpJ6LUw2jhFXuuV/ZSSUW5ydHEHHiYQ6cnd6sBYv/76 Vh8oI4hW8+5so6VqWaCHyUx94fvX9DKZe3jWN7Hsfekzkybv8/s4i58Jnr+kBI3hmbN0GC OhkrVokTSCG4CUeqfjG5ga1KMycYDKvPlRHegSWkane4wRqCJMniVf+7En4J7w== ARC-Authentication-Results: i=1; aspmx1.migadu.com; dkim=pass header.d=telenet.be header.s=r22 header.b=i2Djyvip; dmarc=pass (policy=none) header.from=telenet.be; spf=pass (aspmx1.migadu.com: domain of "guix-devel-bounces+larch=yhetil.org@gnu.org" designates 209.51.188.17 as permitted sender) smtp.mailfrom="guix-devel-bounces+larch=yhetil.org@gnu.org" X-Migadu-Spam-Score: -6.22 Authentication-Results: aspmx1.migadu.com; dkim=pass header.d=telenet.be header.s=r22 header.b=i2Djyvip; dmarc=pass (policy=none) header.from=telenet.be; spf=pass (aspmx1.migadu.com: domain of "guix-devel-bounces+larch=yhetil.org@gnu.org" designates 209.51.188.17 as permitted sender) smtp.mailfrom="guix-devel-bounces+larch=yhetil.org@gnu.org" X-Migadu-Queue-Id: D02C4172A7 X-Spam-Score: -6.22 X-Migadu-Scanner: scn0.migadu.com X-TUID: 0/Ef0Rqaw/L8 --=-pjtYqEkXAZcevfy31WxF Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable bokr@bokr.com schreef op za 04-06-2022 om 01:55 [+0200]: > I am not expert on kernel link internals, but if > you need/prefer atomic change to a specific link, > does my log [1] below suggest a way? > [...] Only the replacing of an old by a new symlink needs to be atomic, and this is already the case. The only non-atomicity is that if interrupted, an extra symlink [...].new can be created, but except for tidyness this is not really a problem AFAICT. Speaking of atomicity, I wonder if 'fsync'ing the symlink or the directory is required? E.g., is it possible after a power interruption for the contents (=3D target) of the new symlink to be truncated without doing a 'fsync' before the rename? Greetings, Maxime. --=-pjtYqEkXAZcevfy31WxF Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- iI0EABYKADUWIQTB8z7iDFKP233XAR9J4+4iGRcl7gUCYpsxNhccbWF4aW1lZGV2 b3NAdGVsZW5ldC5iZQAKCRBJ4+4iGRcl7nR4AP0fHvF2vYi+141tba0qYDRcRq5Y DqOZJNMnTXlGmD/vFwEAih5NrTOn8mrmuwzkmhw2RAPVCjypu1Boh0mKaiyXPgE= =aFEJ -----END PGP SIGNATURE----- --=-pjtYqEkXAZcevfy31WxF--