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=-8.2 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 85FCFC3F2CD for ; Thu, 5 Mar 2020 11:41:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4E6AB2146E for ; Thu, 5 Mar 2020 11:41:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=gmx.net header.i=@gmx.net header.b="QCNnlePQ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727070AbgCELlk (ORCPT ); Thu, 5 Mar 2020 06:41:40 -0500 Received: from mout.gmx.net ([212.227.17.20]:47089 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725912AbgCELlk (ORCPT ); Thu, 5 Mar 2020 06:41:40 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1583408494; bh=Q54CIMNwOtcRr9BJ1KxNgaadOugYZPR1W2HviyGltC4=; h=X-UI-Sender-Class:Subject:To:References:From:Date:In-Reply-To; b=QCNnlePQycNKZlyO7KY5fg7lof4j2QhTchTMf3feFrbV3ER+iY3lef4YV7zUtoMrm W2L0aoPUkxh6q2jn8Hs5EE3VN9odYNwaN+0F0iwxUtkByfaUePphVNiZFevQnfS98A jLo5cGbNHHYQherWFOdYLAlj5FkeGPyIKcrQWfZY= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from [0.0.0.0] ([149.28.201.231]) by mail.gmx.com (mrgmx105 [212.227.17.174]) with ESMTPSA (Nemesis) id 1McH9Y-1jmBV33G9s-00cdrz; Thu, 05 Mar 2020 12:41:34 +0100 Subject: Re: [PATCH 6/8] btrfs: clear BTRFS_ROOT_DEAD_RELOC_TREE before dropping the reloc root To: Josef Bacik , linux-btrfs@vger.kernel.org, kernel-team@fb.com References: <20200304161830.2360-1-josef@toxicpanda.com> <20200304161830.2360-7-josef@toxicpanda.com> From: Qu Wenruo Autocrypt: addr=quwenruo.btrfs@gmx.com; prefer-encrypt=mutual; keydata= mQENBFnVga8BCACyhFP3ExcTIuB73jDIBA/vSoYcTyysFQzPvez64TUSCv1SgXEByR7fju3o 8RfaWuHCnkkea5luuTZMqfgTXrun2dqNVYDNOV6RIVrc4YuG20yhC1epnV55fJCThqij0MRL 1NxPKXIlEdHvN0Kov3CtWA+R1iNN0RCeVun7rmOrrjBK573aWC5sgP7YsBOLK79H3tmUtz6b 9Imuj0ZyEsa76Xg9PX9Hn2myKj1hfWGS+5og9Va4hrwQC8ipjXik6NKR5GDV+hOZkktU81G5 gkQtGB9jOAYRs86QG/b7PtIlbd3+pppT0gaS+wvwMs8cuNG+Pu6KO1oC4jgdseFLu7NpABEB AAG0IlF1IFdlbnJ1byA8cXV3ZW5ydW8uYnRyZnNAZ214LmNvbT6JAU4EEwEIADgCGwMFCwkI BwIGFQgJCgsCBBYCAwECHgECF4AWIQQt33LlpaVbqJ2qQuHCPZHzoSX+qAUCXZw1oQAKCRDC PZHzoSX+qCY6CACd+mWu3okGwRKXju6bou+7VkqCaHTdyXwWFTsr+/0ly5nUdDtT3yEVggPJ 3VP70wjlrxUjNjFb6iIvGYxiPOrop1NGwGYvQktgRhaIhALG6rPoSSAhGNjwGVRw0km0PlIN D29BTj/lYEk+jVM1YL0QLgAE1AI3krihg/lp/fQT53wLhR8YZIF8ETXbClQG1vJ0cllPuEEv efKxRyiTSjB+PsozSvYWhXsPeJ+KKjFen7ebE5reQTPFzSHctCdPnoR/4jSPlnTlnEvLeqcD ZTuKfQe1gWrPeevQzgCtgBF/WjIOeJs41klnYzC3DymuQlmFubss0jShLOW8eSOOWhLRuQEN BFnVga8BCACqU+th4Esy/c8BnvliFAjAfpzhI1wH76FD1MJPmAhA3DnX5JDORcgaCbPEwhLj 1xlwTgpeT+QfDmGJ5B5BlrrQFZVE1fChEjiJvyiSAO4yQPkrPVYTI7Xj34FnscPj/IrRUUka 68MlHxPtFnAHr25VIuOS41lmYKYNwPNLRz9Ik6DmeTG3WJO2BQRNvXA0pXrJH1fNGSsRb+pK EKHKtL1803x71zQxCwLh+zLP1iXHVM5j8gX9zqupigQR/Cel2XPS44zWcDW8r7B0q1eW4Jrv 0x19p4P923voqn+joIAostyNTUjCeSrUdKth9jcdlam9X2DziA/DHDFfS5eq4fEvABEBAAGJ ATwEGAEIACYCGwwWIQQt33LlpaVbqJ2qQuHCPZHzoSX+qAUCXZw1rgUJCWpOfwAKCRDCPZHz oSX+qFcEB/95cs8cM1OQdE/GgOfCGxwgckMeWyzOR7bkAWW0lDVp2hpgJuxBW/gyfmtBnUai fnggx3EE3ev8HTysZU9q0h+TJwwJKGv6sUc8qcTGFDtavnnl+r6xDUY7A6GvXEsSoCEEynby 72byGeSovfq/4AWGNPBG1L61Exl+gbqfvbECP3ziXnob009+z9I4qXodHSYINfAkZkA523JG ap12LndJeLk3gfWNZfXEWyGnuciRGbqESkhIRav8ootsCIops/SqXm0/k+Kcl4gGUO/iD/T5 oagaDh0QtOd8RWSMwLxwn8uIhpH84Q4X1LadJ5NCgGa6xPP5qqRuiC+9gZqbq4Nj Message-ID: <21e4b656-af48-d10c-c549-11770eba541a@gmx.com> Date: Thu, 5 Mar 2020 19:41:28 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.5.0 MIME-Version: 1.0 In-Reply-To: <20200304161830.2360-7-josef@toxicpanda.com> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="8NmwvuXo6qTe2hByXjHHsWxnUcITzXuV8" X-Provags-ID: V03:K1:kDpaTjm8Fq8ZkBNj8bK0wQj0jZB0TUm7wzFnWRx6f45IRagDbv+ kuDMIcW3l5LHoNNMLfO8xSwlzkUhM/kwObGr+lAkHJhEbXBppYWfKHsFbNxIjsdGgpY0nOT WpXXGtOScSWj2ffUfnZyiK1R5Ou/Sbcqs8f0Kr/KgpgTUckfRISJcPdTEGR4gjot3TIXu/y +nqATfqTT+pV1FE5hEg9g== X-UI-Out-Filterresults: notjunk:1;V03:K0:VJOBN5UZ3sU=:GKBGGtt9MxDYz0syvphulW ExMCioj8fmHUTNGp6KOjHbeiPR/y/gGI2NoexhS21BbVC8AwQBMPPi6pGh2SoREB9kLg/knZU 10fE7sPXJx0i7C+ZRZ5cvkvrwF5kEB+6yOCBPw8Pd1LR3jUYLf2QLmjfSOmzTSR2gLCcCCC/3 fEjbt26094GkEu8Hcuq0WZrPMRWrXW8zGYii5JawGVGAKm/g08wf2sUVfGCjp3PEVnDAxgY2l 9oguMwYZ6GeKw8VlxUmOsvMKXLJYiNDUwaZp6vyJvNjvaInXCPbUHQLhjrhPFAa9U5lZdGUvU J1TvB1FmitRKKCoRXEcsmKU/OWRN59qzca4/wVHqsPqh8cDv8ZZpREjK4w84xwJpjm1WWE88n /NxlL/UfJtlQ+V8QtNO1q8zZivAWy2iQpLS6uxsLKKq75Z6aAIrRRcnMjucfZT/uhf4ELjOO/ Xpkz3G2CRymNm0I5otYaOI27Hkeq0MoFUAgprji5ZMviya6LKsQzY7Tb/xQUgL2OtyGOWQ6Ic ci//CdOv4U7KyM6YRC/KbJ0zVbP40JWPykXpVwRyLVKO+04rryk4rWyUNJ/rmUu+hPHd9Pdva ZIZEyTTyGqnJpnpoDkMt2ZxoH6W9+6tiY6Hssnt3Y5RXeRdftT4ZChqug7qIyhOlOldW8Fqf8 QVVRwbGxLNYhKSX4Jbq+DkPr4T4pg66JcE7/iv43GFJctuhcNwTNpgHiBSgR43pb0eQUwpEcA pcsS9v9dJ1c+EuFEDUWzFco3lfk6acCfGv8EelBXP2wsuc4u5uMj/ZtjQ6LW5se9feUYD20aK h7ijfxkD19yGJf5Y3ddTpJT+gw/wSEjK/b824Nj8OvXdgAN9gRGhFDTHoEcjGZhHkO1GdtLC4 dWx01wzUmOLy/KJVG8Bmagzk+iije+PRyp6JxmMIMHJdXYIo4m6rclG+WrCxKDiwmD7DNlGZZ 1rwb9PeNcgbDAc0wCqk4xjSi/Z6Nv/0Ovn+aSChxfcqKgF3Egv/bgTkGWr5CpEbvMRTo7sqrt 0hniJgOFVs/qcM9KtLnVg1QiKWcoS9GP8BVhPBbiJ+FHQ10OiA9PEelYE+OS5IdRD4pesptcW okC6LEmBiTK7CRKME2jORPMagDBScWsHo+31xLHrhIchz9Otnb6kTHfgleeffWCnl4QnPqOen 9OXuCgCNOZOa/mApExIM2swAXJL5SoJoFQhDkxctZVjNpglZJS+Rr1vr9I54yU5FH6kuBPYB3 8/9z+tJjC9eBu3+mY 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) --8NmwvuXo6qTe2hByXjHHsWxnUcITzXuV8 Content-Type: multipart/mixed; boundary="K1gCE1pXARMNnPzoHYf5aPzYvAweHSTls" --K1gCE1pXARMNnPzoHYf5aPzYvAweHSTls Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable On 2020/3/5 =E4=B8=8A=E5=8D=8812:18, Josef Bacik wrote: > We were doing the clear dance for the reloc root after doing the drop o= f > the reloc root, which means we have a giant window where we could miss > having BTRFS_ROOT_DEAD_RELOC_TREE unset and the reloc_root =3D=3D NULL.= Still, I can't see the problem where we have BTRFS_ROOT_DEAD_RELOC_TREE and reloc_root =3D=3D NULL. IMHO, that would cause anything wrong. Or is there anything I missed? Thanks, Qu >=20 > Signed-off-by: Josef Bacik > --- > fs/btrfs/relocation.c | 13 +++++++------ > 1 file changed, 7 insertions(+), 6 deletions(-) >=20 > diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c > index 53509c367eff..ceb90d152cdd 100644 > --- a/fs/btrfs/relocation.c > +++ b/fs/btrfs/relocation.c > @@ -2291,18 +2291,19 @@ static int clean_dirty_subvols(struct reloc_con= trol *rc) > =20 > list_del_init(&root->reloc_dirty_list); > root->reloc_root =3D NULL; > - if (reloc_root) { > - > - ret2 =3D btrfs_drop_snapshot(reloc_root, NULL, 0, 1); > - if (ret2 < 0 && !ret) > - ret =3D ret2; > - } > /* > * Need barrier to ensure clear_bit() only happens after > * root->reloc_root =3D NULL. Pairs with have_reloc_root. > */ > smp_wmb(); > clear_bit(BTRFS_ROOT_DEAD_RELOC_TREE, &root->state); > + > + if (reloc_root) { > + > + ret2 =3D btrfs_drop_snapshot(reloc_root, NULL, 0, 1); > + if (ret2 < 0 && !ret) > + ret =3D ret2; > + } > btrfs_put_root(root); > } else { > /* Orphan reloc tree, just clean it up */ >=20 --K1gCE1pXARMNnPzoHYf5aPzYvAweHSTls-- --8NmwvuXo6qTe2hByXjHHsWxnUcITzXuV8 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEELd9y5aWlW6idqkLhwj2R86El/qgFAl5g5WgACgkQwj2R86El /qhU5QgAkP2PbTVrDNtP8rqZgcnJa5CYuMvMi7Fz9I97MGW+x7Mv3FDsihbgJlgk aGBDzH+C3WyuIunJnRaC+thxKcn3kDAzHhzdYEIe0SUDpCL0oF1WkQrQW8d3Ygfj f2gDQ57aZ6PWQLa9kg/LYfK1ruEpekiqmG0YzZ27oV1ZZ1QG/WjGcEolxQ5wgrLt UXAftteICuknIeVg59hBUxn5UjFY+q7wDYGKrY7Iiv+vaedegWfecYW6R+Q4CYXU VmQnOZPn3RIC7yjKagn0LcpeBNLhoj+aU0D9+J2lTEoEZx2zlp3Q48c1J5JYUMdm 5xJ88ObOSvDcucDdWqeZL6Z6PI5SQg== =U7DC -----END PGP SIGNATURE----- --8NmwvuXo6qTe2hByXjHHsWxnUcITzXuV8--