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 X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5EC8AC04AB6 for ; Mon, 3 Jun 2019 06:53:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 21321250D6 for ; Mon, 3 Jun 2019 06:53:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=gmx.net header.i=@gmx.net header.b="EcWFNAHV" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726896AbfFCGxR (ORCPT ); Mon, 3 Jun 2019 02:53:17 -0400 Received: from mout.gmx.net ([212.227.17.22]:59495 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726565AbfFCGxR (ORCPT ); Mon, 3 Jun 2019 02:53:17 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1559544787; bh=sdw1sLuzm/K/O2lyCPElh7zPXQSnKfVQtjW7A5Qew+Y=; h=X-UI-Sender-Class:Subject:To:References:From:Date:In-Reply-To; b=EcWFNAHVyG2ViR5qAZ2916sPhK88cdWjvAjzXZc5CsI2bCzO6B5EmZlPgZeGz1g7/ UPkKANc11gevoqAgPL+rDykq4VXhNxJprIkfUePs9fAt9LRPNZ4Lrsnm/RoxIPhGCP R0ynBVukgZTrg21FXiCFBr/4JAT21WPEnu3XsnLk= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from [0.0.0.0] ([54.250.245.166]) by mail.gmx.com (mrgmx104 [212.227.17.174]) with ESMTPSA (Nemesis) id 1N2Dx8-1gZa9P1R6M-013doj; Mon, 03 Jun 2019 08:53:07 +0200 Subject: Re: [PATCH] btrfs: don't end the transaction for delayed refs in throttle To: dsterba@suse.cz, Josef Bacik , linux-btrfs@vger.kernel.org, kernel-team@fb.com References: <20190124143143.8838-1-josef@toxicpanda.com> <20190212160351.GD2900@twin.jikos.cz> From: Qu Wenruo Openpgp: preference=signencrypt Autocrypt: addr=quwenruo.btrfs@gmx.com; prefer-encrypt=mutual; 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Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 MIME-Version: 1.0 In-Reply-To: <20190212160351.GD2900@twin.jikos.cz> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="AJI4D1j3bnbCKKygAvw1JjIu7FyYoD1GK" X-Provags-ID: V03:K1:oFyamZe1kBTT0gdFDZ8o5tAHdqZcdv533ziREn99c0t5DprlMYz Bx+aXpF+e1nrF8lPbTYIRBG/pe99SjWgezlQob8rtG6zhfMM8k4caOq1keksXQv6hVbm/Bn N6R970txFjQtd+srIvE4jWz9LJmacnLWfgai40F/F37F0Fa9g+KCsJduWYE+CSoktKsR6A9 40YRjFrXgJyMBTDkKot3g== X-UI-Out-Filterresults: notjunk:1;V03:K0:wTln/D/2efQ=:yW6dPeX9JKtBj60xFyeIM4 CsE5cVBU/o2SrNs9pKq7CT7I9EsOv0ppLpXjABQ+g5fabFvs6DDqKQ2mKCVjWXLBnkSdgZ+nI /0a///Vf7WHQBHtPMrZpn/gwyEZR6SL8ViARHLNr5+fesR6ZcZeJkvuEV1alp2tvZTAKnrpIe 3cjZufBfKRtIXCm0yv8DEMKVrXAJPIR0V29PKpTpoT80Mu0CqE470FNwibcCyhSy6HtQla+7y ruLtK9SgYLSU/WfhQhtxrY1nnRVCEBrbMwZPvbdVRqd6FhskRJTD7UKf5cRWcMUIRP5svCpzb 9vaSaNYF45P5blcDLOxUuFgR9KETFPkTkz3J5ZCEwYnN4KXW/nGs6t0cI16Dq4qVsZ+08EweG 4CiHO3QYUXcUTHW5qg1WIX7erS01v246MqkdWkHbfelWcrR3VreheJ4k7N0cGXpuBRUaopdzM KnS5xv06HMiR3H0Q/aPhJYs4Kahm07zK6LK1H+tePDCjOlOgZaz/un7Bg/rTeMnnkopTatVtZ SOzWgqyvb7tb6k9vaX2iHnzTihAoP3fdESUqAy76kMUH14ZjZmIW43JbXH7QisnX6zQS05Vux LAl0YUVztXA7R/AoJgdDuobhjK3lqzigbOcwBTq0e/0CriyG+na82cXLc925F66pE/M+uW+La KlhA1pZCGmtq30TDbNhs4yds93vtnTYBnV/KTP4Pk725pKw+rQuetQZA78oIvGa05bBr6f21x idsgLma6MrQtv2P3llIU+n62go68cOxJFgYbHL1o2YYdb+QrmU0IgvVahXgjATNtG4T9xtcMo OctGPX+yCqqV8sPtiC9Z4ap/oTKqGnJdH3UiFay3OJv70As4Rc4zL6t+LAspYdTha4FXibUIl ODCwmDyBzjBtlKQU7CboDyFQsIh1t4ht/sZf6YDkupih+23MQl998fXUkjtcIbjg9wXgQUI7t ZwlpbhJEawJdjDYoKs0tBo5227wvHI5c= Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --AJI4D1j3bnbCKKygAvw1JjIu7FyYoD1GK Content-Type: multipart/mixed; boundary="oMTVu5Eip6Ncb6a5LSloskPOQ3W4A7DmE"; protected-headers="v1" From: Qu Wenruo To: dsterba@suse.cz, Josef Bacik , linux-btrfs@vger.kernel.org, kernel-team@fb.com Message-ID: Subject: Re: [PATCH] btrfs: don't end the transaction for delayed refs in throttle References: <20190124143143.8838-1-josef@toxicpanda.com> <20190212160351.GD2900@twin.jikos.cz> In-Reply-To: <20190212160351.GD2900@twin.jikos.cz> --oMTVu5Eip6Ncb6a5LSloskPOQ3W4A7DmE Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable On 2019/2/13 =E4=B8=8A=E5=8D=8812:03, David Sterba wrote: > On Thu, Jan 24, 2019 at 09:31:43AM -0500, Josef Bacik wrote: >> Previously callers to btrfs_end_transaction_throttle() would commit th= e >> transaction if there wasn't enough delayed refs space. This happens i= n >> relocation, and if the fs is relatively empty we'll run out of delayed= >> refs space basically immediately, so we'll just be stuck in this loop = of >> committing the transaction over and over again. >> >> This code existed because we didn't have a good feedback mechanism for= >> running delayed refs, but with the delayed refs rsv we do now. Delete= >> this throttling code and let the btrfs_start_transaction() in relocati= on >> deal with putting pressure on the delayed refs infrastructure. With >> this patch we no longer take 5 minutes to balance a metadata only fs. >> >> Signed-off-by: Josef Bacik >=20 > For the record, this has been merged to 5.0-rc5 >=20 Bisecting leads me to this patch for strange balance ENOSPC. Can be reproduced by btrfs/156, or the following small script: ------ #!/bin/bash dev=3D"/dev/test/test" mnt=3D"/mnt/btrfs" _fail() { echo "!!! FAILED: $@ !!!" exit 1 } do_work() { umount $dev &> /dev/null umount $mnt &> /dev/null mkfs.btrfs -b 1G -m single -d single $dev -f > /dev/null mount $dev $mnt for i in $(seq -w 0 511); do # xfs_io -f -c "falloc 0 1m" $mnt/file_$i > /dev/null xfs_io -f -c "pwrite 0 1m" $mnt/inline_$i > /dev/null done sync btrfs balance start --full $mnt || return 1 sync btrfs balance start --full $mnt || return 1 umount $mnt } failed=3D0 for i in $(seq -w 0 24); do echo "=3D=3D=3D run $i =3D=3D=3D" do_work if [ $? -eq 1 ]; then failed=3D$(($failed + 1)) fi done if [ $failed -ne 0 ]; then echo "!!! failed $failed/25 !!!" else echo "=3D=3D=3D all passes =3D=3D=3D" fi ------ For v4.20, it will fail at the rate around 0/25 ~ 2/25 (very rare). But at that patch (upstream commit 302167c50b32e7fccc98994a91d40ddbbab04e52), the failure rate raise to 25/2= 5. Any idea for that ENOSPC problem? As it looks really wired for the 2nd full balance to fail even we have enough unallocated space. Thanks, Qu --oMTVu5Eip6Ncb6a5LSloskPOQ3W4A7DmE-- --AJI4D1j3bnbCKKygAvw1JjIu7FyYoD1GK Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEELd9y5aWlW6idqkLhwj2R86El/qgFAlz0w8wACgkQwj2R86El /qhJDAgAh23SIN/EU2c/8g+MG4E1swKsi+WfB3xiR6XSPqXGV5JcTtVlCzLSg2wC RaxhOD4lz0k3iUHPu6g1YTnOH6bM30WehXNjOkyATBo2vXFJc7A2/PGumxN4MU7m m8n4LISXCC9A3I+j8dbV586vinP4Yhg0KYyk+6GrWDyVlueNICVyBsU597YjRttM uAGJvTidbPtAJtIU4vi+Rq/jd5t4DgOUqvfOTAs5BeJIqGKzx6R6fZKD4rI1hroD dXpy2c4yRkrh0qbdNJlvSzVEPaM0RGHyEpZRjTjYAK/x5bJR3lLmmZ+/mCXCNHHC t+NsRzThtBZEmw0w9misa4pGO1vzPw== =8tfx -----END PGP SIGNATURE----- --AJI4D1j3bnbCKKygAvw1JjIu7FyYoD1GK--