From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from meiko.romanrm.net ([195.154.92.155]:56484 "EHLO meiko.romanrm.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934055AbcATP3P (ORCPT ); Wed, 20 Jan 2016 10:29:15 -0500 Received: from natsu (unknown [IPv6:fd39::e9:9eff:fe8f:1bcf]) by meiko.romanrm.net (Postfix) with SMTP id 5D7F7FD46A for ; Wed, 20 Jan 2016 15:29:10 +0000 (UTC) Date: Wed, 20 Jan 2016 20:29:09 +0500 From: Roman Mamedov To: linux-btrfs@vger.kernel.org Subject: Kernel 4.4.0 intermittent ENOSPC during heavy data write and concurrent snapshotting Message-ID: <20160120202909.4a804707@natsu> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=PGP-SHA1; boundary="Sig_/Corgr6GwHJOVgoD10yojqZr"; protocol="application/pgp-signature" Sender: linux-btrfs-owner@vger.kernel.org List-ID: --Sig_/Corgr6GwHJOVgoD10yojqZr Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable Hello, To reproduce... *) in one terminal window: btrfs sub create test chattr +C test cd test/ while true; do dd if=3D/dev/zero of=3Dzerofile bs=3D1M count=3D1024; sy= nc; done *) in another terminal window start repeatedly snapshotting 'test', at rand= om 1-3-5 second intervals:=20 mkdir snaps btrfs sub snap test snaps/test-`date +%Y-%m-%dT%H:%M:%S` The 'dd' output of first window then looks like this for me: 1024+0 records in 1024+0 records out 1073741824 bytes (1.1 GB) copied, 0.49982 s, 2.1 GB/s 1024+0 records in 1024+0 records out 1073741824 bytes (1.1 GB) copied, 0.541291 s, 2.0 GB/s 1024+0 records in 1024+0 records out 1073741824 bytes (1.1 GB) copied, 4.88021 s, 220 MB/s 1024+0 records in 1024+0 records out 1073741824 bytes (1.1 GB) copied, 4.56427 s, 235 MB/s 1024+0 records in 1024+0 records out 1073741824 bytes (1.1 GB) copied, 0.530991 s, 2.0 GB/s 1024+0 records in 1024+0 records out 1073741824 bytes (1.1 GB) copied, 5.68497 s, 189 MB/s dd: writing `zerofile': No space left on device 1+0 records in 0+0 records out 0 bytes (0 B) copied, 0.000591943 s, 0.0 kB/s 1024+0 records in 1024+0 records out 1073741824 bytes (1.1 GB) copied, 4.25015 s, 253 MB/s 1024+0 records in 1024+0 records out 1073741824 bytes (1.1 GB) copied, 4.66459 s, 230 MB/s dd: writing `zerofile': No space left on device 1015+0 records in 1014+0 records out 1063489536 bytes (1.1 GB) copied, 3.0433 s, 349 MB/s 1024+0 records in 1024+0 records out 1073741824 bytes (1.1 GB) copied, 4.24264 s, 253 MB/s dd: writing `zerofile': No space left on device 1+0 records in 0+0 records out 0 bytes (0 B) copied, 0.000647234 s, 0.0 kB/s 1024+0 records in 1024+0 records out 1073741824 bytes (1.1 GB) copied, 3.56673 s, 301 MB/s 1024+0 records in 1024+0 records out 1073741824 bytes (1.1 GB) copied, 3.71281 s, 289 MB/s 1024+0 records in 1024+0 records out 1073741824 bytes (1.1 GB) copied, 0.551317 s, 1.9 GB/s ^C ----- This also causes my KVM VMs to fail with a high probability during snapshotting of their backing subvolume (as described in the previous threa= d). --=20 With respect, Roman --Sig_/Corgr6GwHJOVgoD10yojqZr Content-Type: application/pgp-signature; name=signature.asc Content-Disposition: attachment; filename=signature.asc -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iEYEARECAAYFAlafp8UACgkQTLKSvz+PZwhekgCfbfRqATnEb1KRwJWEUTziEnHc qtAAnA6A4gaph0O2cuH/y2P1NUqp/Xw0 =y9VA -----END PGP SIGNATURE----- --Sig_/Corgr6GwHJOVgoD10yojqZr--