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=-8.0 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, 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 829EAC33C9E for ; Sat, 11 Jan 2020 09:25:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3401F206DA for ; Sat, 11 Jan 2020 09:25:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=gmx.net header.i=@gmx.net header.b="iXrLiLQu" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728660AbgAKJZE (ORCPT ); Sat, 11 Jan 2020 04:25:04 -0500 Received: from mout.gmx.net ([212.227.17.20]:43143 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728346AbgAKJZE (ORCPT ); Sat, 11 Jan 2020 04:25:04 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1578734698; bh=s5z7CmCf3Xs4IVvJLZZq4pQfUgFNZp5NrbXbObPLZgQ=; h=X-UI-Sender-Class:Subject:To:References:From:Date:In-Reply-To; b=iXrLiLQuvBYvKzzq2x58q2bseeVYHQX9tUVNPgqqspTNCqu/OaoDvpO7jNav3qtWf XtY+lW4lJcEm7x0igVzbHG/NRLRWXDyihWadZtdEDuZPwX5RSM7c2VUB0elxIEGSFo oad1nebTvTrlbHbdMlOD5fPy1zPOpafTINGcKhKY= 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 1M42nY-1iqD0r3o9Y-0007M1; Sat, 11 Jan 2020 10:24:58 +0100 Subject: Re: [PATCH 1/5] btrfs: check rw_devices, not num_devices for restriping To: Josef Bacik , linux-btrfs@vger.kernel.org, kernel-team@fb.com References: <20200110161128.21710-1-josef@toxicpanda.com> <20200110161128.21710-2-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: Date: Sat, 11 Jan 2020 17:24:54 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.3.1 MIME-Version: 1.0 In-Reply-To: <20200110161128.21710-2-josef@toxicpanda.com> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="gSX2gT9KLLNxQFdmyEqTnhyABh2KzgmpA" X-Provags-ID: V03:K1:FaxYfVfEJuRsKV9KZ/c50e+iarjKJp26QC5TBtZa8XFfPlVVF/8 rLHaKDg2Ly/yxpslVsY3FXgDyTDpFDc5YFvudx3RArN1UPf1V5DmVbOWTEIxPs5KjFb4A2V gBE6ZHR1kujjtMY+v+wIlvyMi6PTH6x8P4zJH9gglpP41FAVprx7Ekmd1MTomW7NrRemM/6 R5QSeerTbR2/tS2I3ssYw== X-UI-Out-Filterresults: notjunk:1;V03:K0:37mxdLObOkc=:spcg4RUrdo+BLPZ/JAIZb6 QHrbOwcn7UpHEL9ipfquFvjgxeA6xIKSPjZjfQ5tVIF7Pv0d7csfKqYN0lBzwozD0/mLhsw5S /JrLR4ag5HnpycXTHmUQpbAa1CmyxFelaqedgK144yA/sxSxw+o8xVBSReJaip9y8wo2ubJUW BtY5i6IQT74afIWaAs6P1Sbp8EVRrwbuRZd3jGFuU7O3NitWYv95NM+hczfrrvOMUyZJQxxhm YKO5YwHBKEcPn0Ig01gb7GCDrJUgYQ4mXnPg61H7why5v45bb/qzi6E6I8I/eZHMN2nmNJQLm +bHWiyANpxoWae/J1SgB2Ge2KD0DofRmUoMM2p7tZVy2gJAstoC04My3EOuvEhmHP99wZm7mY 5vC31jS9JQD3JVVgHGvOyCD5dDFa/h/X6ctu0jz6+k6qbazb6a4k/p7Md2f+FHFJUHYRLlzb+ VYn9+l+jRQJrNdGWkx8be/GL46te/cxpT2YrkmnSe56bCeGKnNGs5aXTwzA3/0s4Y9jAZT0/Y FZOEINkEozYaxgY8Mv4yQKPRhzyQIyu0bL2iB8kwarAOyRttGqtwge67XfaoF2x78lxhEu41/ a2f+KFLT18UsqQheYaibGKA6vl8CMPxbvFa70Ezp65VWJ0yOdVfi9b83IYlCLIFlCZtkVZcb7 hkUBLjB3n0jQqi/wq4OE95rmt9mXnq8QSgx+7fzpgoa7DbZNSmTmkz6+cS6Iv+4QtslQqVOXj K1GIqfHMHulyVUJJ5dQhT9jXFDCwm80BFlYbu+v45NMEAL0rPo0K6C4NQY2A0yyUuxl27n9ht JQFimw7KjIoFYFe8icZlxHRstZYlqT2lnzqv7aj+gsI1limhNNvsXkNM6NTeNJhP5IqkrQoMI HKkJjCW5IRtxt3xNmZKUTdQau3xHOJrt7cULDNdjACm8V5NHeyvtS4t+Lk+vI3IVQu5p9wEFb JtGnaNIlwpAcE288jznwfY+muM6euffophHcY9tr8lptUcpjInjTln04iu/0HYY9Y1CV3B8Ex NqVBhErQb6D1az5rTzJ3DwqRHPbu4rUeND9QFgjlJR3cHWwmE9VpQWDCZiBSno6/D3VTjsYp0 bC0aJjeVGWAVS0BIUri05i1oJ/0cNnMvdbvNFgODjV+keBOs/SZDdcERL6Wd+tJ1KdWL7mnra oJuZb3j8wrwVOxRRgvLUVKG1go+yLgKqyRmApfek77r7KbVPzq77W8UJEarjbxKiNVJAfNBCS 6HWYP1BehdduK3AhDlihj7bhzYJf3Wa+3k7nMj+XkLtQeh+0laNR0Szgg77M= 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) --gSX2gT9KLLNxQFdmyEqTnhyABh2KzgmpA Content-Type: multipart/mixed; boundary="cWOqjduMvWkn0GU7664SLvc45T6M0O6O7" --cWOqjduMvWkn0GU7664SLvc45T6M0O6O7 Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable On 2020/1/11 =E4=B8=8A=E5=8D=8812:11, Josef Bacik wrote: > While running xfstests with compression on I noticed I was panicing on > btrfs/154. I bisected this down to my inc_block_group_ro patches, whic= h > was strange. >=20 > What was happening is with my patches we now use btrfs_can_overcommit()= > to see if we can flip a block group read only. Before this would fail > because we weren't taking into account the usable un-allocated space fo= r > allocating chunks. With my patches we were allowed to do the balance, > which is technically correct. >=20 > However this test is testing restriping with a degraded mount, somethin= g > that isn't working right because Anand's fix for the test was never > actually merged. >=20 > So now we're trying to allocate a chunk and cannot because we want to > allocate a RAID1 chunk, but there's only 1 device that's available for > usage. This results in an ENOSPC in one of the BUG_ON(ret) paths in > relocation (and a tricky path that is going to take many more patches t= o > fix.) >=20 > But we shouldn't even be making it this far, we don't have enough > devices to restripe. The problem is we're using btrfs_num_devices(), > which for some reason includes missing devices. That's not actually > what we want, we want the rw_devices. >=20 > Fix this by getting the rw_devices. With this patch we're no longer > panicing with my other patches applied, and we're in fact erroring out > at the correct spot instead of at inc_block_group_ro. The fact that > this was working before was just sheer dumb luck. >=20 > Fixes: e4d8ec0f65b9 ("Btrfs: implement online profile changing") > Signed-off-by: Josef Bacik > --- > fs/btrfs/volumes.c | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) >=20 > diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c > index 7483521a928b..a92059555754 100644 > --- a/fs/btrfs/volumes.c > +++ b/fs/btrfs/volumes.c > @@ -3881,7 +3881,14 @@ int btrfs_balance(struct btrfs_fs_info *fs_info,= > } > } > =20 > - num_devices =3D btrfs_num_devices(fs_info); > + /* > + * rw_devices can be messed with by rm_device and device replace, so > + * take the chunk_mutex to make sure we have a relatively consistent > + * view of the fs at this point. > + */ > + mutex_lock(&fs_info->chunk_mutex); > + num_devices =3D fs_info->fs_devices->rw_devices; > + mutex_unlock(&fs_info->chunk_mutex); chunk_mutex is the correct lock for rw_devices counter and alloc_list. So, Reviewed-by: Qu Wenruo Thanks, Qu > =20 > /* > * SINGLE profile on-disk has no profile bit, but in-memory we have a= >=20 --cWOqjduMvWkn0GU7664SLvc45T6M0O6O7-- --gSX2gT9KLLNxQFdmyEqTnhyABh2KzgmpA Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEELd9y5aWlW6idqkLhwj2R86El/qgFAl4ZlGYACgkQwj2R86El /qhHxggAgs75zPSkFPBMZ3U5G9ZagJB7NxVBG9tZ1c8X7M8IOpUqaIVf0cxUKsGl rqz1kK0JJjNczJOxeBgxXHljHcelTIvpENRHRtu8S1NN2lRawiLgAdwbujY+nvUI 9ocTEtnBtkoRKYEH3R8VIwuypxCUcYRET9eh1vCxMdkE6YC6KAMwGFDE2HKsG91C NE1wixOf8T2L9VczUjCjCCbAnPGT/+2mNAMWNnR2Lcz9M7/k5CVg9Yry86vbDU46 IIHeg8yoVBIl9KE8oSDgqzjn+bIdL+6O+IhNu8kqLCCytvNwTzTaJkOGjbWm+FUA CW0XzS99h0kCXb9TUY7e80mXquYLuA== =AWsr -----END PGP SIGNATURE----- --gSX2gT9KLLNxQFdmyEqTnhyABh2KzgmpA--