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=-2.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 2ED17C433DF for ; Fri, 12 Jun 2020 05:38:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EADB120836 for ; Fri, 12 Jun 2020 05:38:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=gmx.net header.i=@gmx.net header.b="cK2C7PEe" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726408AbgFLFiM (ORCPT ); Fri, 12 Jun 2020 01:38:12 -0400 Received: from mout.gmx.net ([212.227.15.18]:58281 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725763AbgFLFiL (ORCPT ); Fri, 12 Jun 2020 01:38:11 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1591940288; bh=rMf4x8/SNDIeYbS9sgo27e04hB7EE2AeXIeKQyeKeSo=; h=X-UI-Sender-Class:Subject:To:References:From:Date:In-Reply-To; b=cK2C7PEehyW8eA/5d6Bkhd6nvSaWXgXfp6dW8Pryel+IAC89YcD9iH+0JaKNN8SFK oMmnia4fLbK8pDIt8LRu8Hd6VkbInA5Ssfixaitga77+ZGKIjt9TWssnojJiILGOAh W3VGWPi3fSRFOQlayJbT3OeMk4Djfn6D4JG4G26Q= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from [0.0.0.0] ([149.28.201.231]) by mail.gmx.com (mrgmx005 [212.227.17.184]) with ESMTPSA (Nemesis) id 1MStCe-1jM4yv15Yc-00UMQl; Fri, 12 Jun 2020 07:38:08 +0200 Subject: Re: BTRFS: Transaction aborted (error -24) To: dsterba@suse.cz, Greed Rong , linux-btrfs@vger.kernel.org References: <20200611112031.GM27795@twin.jikos.cz> <20200611135244.GP27795@twin.jikos.cz> 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: <434d03cf-01ba-3051-8dcb-22fd70de9957@gmx.com> Date: Fri, 12 Jun 2020 13:38:03 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.9.0 MIME-Version: 1.0 In-Reply-To: <20200611135244.GP27795@twin.jikos.cz> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="YFtLf5xZUeuJnpu54PVPaHRvkz9sxI82T" X-Provags-ID: V03:K1:qmfQzOAxzW0tnn5NN/0AU+UzSdNbhz0iNMHiaeHEpevlHHuYeh0 MlIgfTKrTgOlCSwAubCifzNP3H8VpuaLH1tnlXmPenT0HSJkq0fqbkA6G8ZolWqGSWfLSSt SqCcdRo7X77nJvuo9AhUK9inlREODbsu71Yo4Bkn6XyiLGKNN0KMiNjaO5KS9+sfA/8Ix+C 4RmgG7tUp4jdrWTbDvzHw== X-UI-Out-Filterresults: notjunk:1;V03:K0:E7OK8c1NO/4=:7CeZBDwUXhHEpldcVIsWb1 SRYwPRM+KTIz8UBhK1h73LpOT5PWCgUBzByCir5JZZD3MnaG+ZIJxy8wXJzfrX+hoV31w77mz ONFVU69mwzDm46xLpgQuiSTx634H7/AUmYajkj4AUXcVfP0CnUWm+JV95+jrPYycQvQxYjQJt /21VViB9zRNGwfxhX2ssU3BUVBvVwZ+oGAkzXuQjTCaQh93Sez5amqQKr7TE+MdAnw7BOMwjK oahi+YSUo0gUv4N/rcmNOCZOGd8TRQkDCl+In6K7uORqawduIZSh9x57Stz9AuYtcBR26A8YU G1LwO3DdhRtm5q3i376/cD+7RsBo1KWSxAhXshOUJcLl8eEuuxbNd2k9LyyjOKpl0FFsnH7yb Rc/rBYIwuW9Ngbpi45F/wFmCjFMuzHZd3h0j1PAN1DDDcUk2syWY6jqrpH4PS6PfU2hKTQHe9 0R/bnHtuwQiTDqAvPVCapLdl4/RNXn9P4x1vVeoB3em0VO5atSu850H84frra7BbLGX4danua rR119FZh9H7cKVYRq6TBYy701x25cYhKv46oKKKaoCeovz/SZH/BlKVX3hkVO2Se8tpqH+DVU MWVH5mibi7f0xCg4WFRejopxdlwhEzYFruHSarO4V6xZLtDIH5i8MJ+Ua6HTBCxoYLpwvwp18 bMDgcUTVRWIzLKKjPsnb28GQsGfgJifWyfBCZT3PwFILDS2993YI4S7fpuWLhVNor4wBcHTSp lr7tC5FeqrgnpS3xi0GvPxsU9SCwvXkFWYThyF1SK6w3PVdU0jTHRTGQUw+OkMsIq99HnFoz9 nmBD2dKBmUHHykEgfhzPzN6MnIBgRaWmamv9y5ndK2DBr1g1L1R3WZphs9KPzIYNSVQmaVhBa gOpW7JWj4MlJF/JFwSNJ2UXKmA/My5bh+19kSeVfrn2opiK4zzZriRYE9lITvV/x3kI/Hwri6 nhnRx4irOGxIUo+XxQVolTr47ZzA0yuAEKW0btSs04Pe5iIL0E9vEXfVGioIa6BddeOXMddrK zh3ANhyoo5/j9pM5l9eou+sN3UtlaGikpp1RNWxD0Cd5b+2iA9C64DT72R2PTPGhuIYWqgLSI 6Zt7DfK0NTgU152xkxVE6//TAgGg+bkcDIA5MXFY2TJpgbNbureMpMiyHc/bkXBLJi8H9juCr c8VrDvejGvv+GBhwj9Q10juvU0u5AdTTonQEzwtARbC3RVq5YwW4k6QxgT1+ZtUU2nxwGaVBF zMpF8bll9FDEL1682 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) --YFtLf5xZUeuJnpu54PVPaHRvkz9sxI82T Content-Type: multipart/mixed; boundary="Dqc8Jn12xlA0FRFlzboH4Djp3pC83ANsk" --Dqc8Jn12xlA0FRFlzboH4Djp3pC83ANsk Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable On 2020/6/11 =E4=B8=8B=E5=8D=889:52, David Sterba wrote: > On Thu, Jun 11, 2020 at 08:37:11PM +0800, Qu Wenruo wrote: >> >> >> On 2020/6/11 =E4=B8=8B=E5=8D=887:20, David Sterba wrote: >>> On Thu, Jun 11, 2020 at 06:29:34PM +0800, Greed Rong wrote: >>>> Hi, >>>> I have got this error several times. Are there any suggestions to av= oid this? >>>> >>>> # dmesg >>>> [7142286.563596] ------------[ cut here ]------------ >>>> [7142286.564499] BTRFS: Transaction aborted (error -24) >>> >>> EMFILE 24 /* Too many open files */ >>> >>> you can increase the open file limit but it's strange that this happe= ns, >>> first time I see this. >> >> Not something from btrfs code, thus it must come from the VFS/MM code.= >=20 > Yeah, this is VFS. Creating a new root will need a new inode and dentry= > and the limits are applied. >=20 >> The offending abort transaction is from btrfs_read_fs_root_no_name(), >> which is updated to btrfs_get_fs_root() in upstream kernel. >> Overall, it's not much different between the upstream and the 5.0.10 k= ernel. >> >> But with latest btrfs_get_fs_root(), after a quick glance, there isn't= >> any obvious location to introduce the EMFILE error. >> >> Any extra info about the worload to trigger the bug? >=20 > I think it's from get_anon_bdev, that's called from btrfs_init_fs_root > (in btrfs_get_fs_root): >=20 > 1073 int get_anon_bdev(dev_t *p) > 1074 { > 1075 int dev; > 1076 > 1077 /* > 1078 * Many userspace utilities consider an FSID of 0 invalid.= > 1079 * Always return at least 1 from get_anon_bdev. > 1080 */ > 1081 dev =3D ida_alloc_range(&unnamed_dev_ida, 1, (1 << MINORBI= TS) - 1, > 1082 GFP_ATOMIC); > 1083 if (dev =3D=3D -ENOSPC) > 1084 dev =3D -EMFILE; > 1085 if (dev < 0) > 1086 return dev; > 1087 > 1088 *p =3D MKDEV(0, dev); > 1089 return 0; > 1090 } > 1091 EXPORT_SYMBOL(get_anon_bdev); >=20 > And comment says "Return: 0 on success, -EMFILE if there are no > anonymous bdevs left ". >=20 > The fs tree roots are created later than the actual command is executed= , > so all the errors are also delayed. For that reason I moved eg. the roo= t > item and path allocation to the first phase. We could do the same for > the anonymous bdev. The first question is, do we really need per-root anonymous bdev? IMHO btrfs can shared the same anonymous bdev across the same fs, no need for each root to own one. The user-visible change would be, statefs() will alwasy return the same bdev for all roots. User would lose the ability to distinguish different roots from the same fs, but I doubt if that would really impact the use cases. Thanks, Qu >=20 > The problem won't go away tough, the question is why is the IDA range > unnamed_dev_ida exhausted. >=20 --Dqc8Jn12xlA0FRFlzboH4Djp3pC83ANsk-- --YFtLf5xZUeuJnpu54PVPaHRvkz9sxI82T Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEELd9y5aWlW6idqkLhwj2R86El/qgFAl7jFLsACgkQwj2R86El /qhCxAgAj1HONylb54kG1/8BOESyxwXnYMurzcZBmyeipf5vOqgau3gHJ0h8xzIH 5CDog5ii7lCJ4a6eDV+TlOCloahGWbeIDTLTIzCcqFUeT79Z0PYwB4JK5bOiSbpt aESxYTpW9r+7fupBsQzY9lkOGZ2Mt0QfNJFChAyvyYa25GzodR23x4sFX1/zVVxl ebmSlhu+Pnh7B5F3JWow9nR8J5xxQKSXZ3PLfwYF7ESuR4kmmNsRLnBAEkbPhOG6 BsAgGZrCpn9u+KtqX/JyRsrpQTYlOy3YOkw8S72gE5J4+8o1rou5H+RtHzbpbzcO 9v2hmZUh/jJwlyZNC/mI4dF5mRjX4Q== =vNEY -----END PGP SIGNATURE----- --YFtLf5xZUeuJnpu54PVPaHRvkz9sxI82T--