From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl0-f68.google.com ([209.85.160.68]:42599 "EHLO mail-pl0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751309AbeEPCSn (ORCPT ); Tue, 15 May 2018 22:18:43 -0400 Date: Wed, 16 May 2018 10:18:38 +0800 From: Eryu Guan Subject: Re: [PATCH] btrfs: test ENOSPC caused by many orphan items Message-ID: <20180516021838.GB29080@desktop.hz.ali.com> References: <20180516014858.GA29080@desktop.hz.ali.com> <20180516021402.GA28521@vader> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180516021402.GA28521@vader> Sender: fstests-owner@vger.kernel.org To: Omar Sandoval Cc: linux-btrfs@vger.kernel.org, fstests@vger.kernel.org, kernel-team@fb.com List-ID: On Tue, May 15, 2018 at 07:14:02PM -0700, Omar Sandoval wrote: > On Wed, May 16, 2018 at 09:48:58AM +0800, Eryu Guan wrote: > > On Wed, May 09, 2018 at 11:21:55PM -0700, Omar Sandoval wrote: > > > From: Omar Sandoval > > > > > > Btrfs has a bug where we can prematurely ENOSPC if we have lots of > > > orphaned files, i.e., deleted files which are still open. Add a test > > > which repeatedly creates and deletes a file while keeping all of the > > > file descriptors open. This should succeed but doesn't on Btrfs without > > > the fix. > > > > > > Signed-off-by: Omar Sandoval > > > --- > > > tests/generic/479 | 0 > > > tests/generic/487 | 65 +++++++++++++++++++++++++++++++++++++++++++ > > > tests/generic/487.out | 2 ++ > > > tests/generic/group | 1 + > > > 4 files changed, 68 insertions(+) > > > mode change 100644 => 100755 tests/generic/479 > > > create mode 100755 tests/generic/487 > > > create mode 100644 tests/generic/487.out > > > > > > diff --git a/tests/generic/479 b/tests/generic/479 > > > old mode 100644 > > > new mode 100755 > > > diff --git a/tests/generic/487 b/tests/generic/487 > > > new file mode 100755 > > > index 00000000..66379cf0 > > > --- /dev/null > > > +++ b/tests/generic/487 > > > @@ -0,0 +1,65 @@ > > > +#! /bin/bash > > > +# FS QA Test 487 > > > +# > > > +# Test having many file descriptors referring to deleted files open. Regression > > > +# test for patch "Btrfs: fix ENOSPC caused by orphan items reservations". > > > +# > > > +#----------------------------------------------------------------------- > > > +# Copyright (c) 2018 Omar Sandoval. All Rights Reserved. > > > +# > > > +# This program is free software; you can redistribute it and/or > > > +# modify it under the terms of the GNU General Public License as > > > +# published by the Free Software Foundation. > > > +# > > > +# This program is distributed in the hope that it would be useful, > > > +# but WITHOUT ANY WARRANTY; without even the implied warranty of > > > +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > > > +# GNU General Public License for more details. > > > +# > > > +# You should have received a copy of the GNU General Public License > > > +# along with this program; if not, write the Free Software Foundation, > > > +# Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA > > > +#----------------------------------------------------------------------- > > > +# > > > + > > > +seq=`basename $0` > > > +seqres=$RESULT_DIR/$seq > > > +echo "QA output created by $seq" > > > + > > > +here=`pwd` > > > +tmp=/tmp/$$ > > > +status=1 # failure is the default! > > > +trap "_cleanup; exit \$status" 0 1 2 3 15 > > > + > > > +_cleanup() > > > +{ > > > + cd / > > > + rm -f $tmp.* > > > +} > > > + > > > +. ./common/rc > > > +. ./common/filter > > > + > > > +rm -f $seqres.full > > > + > > > +_supported_fs generic > > > +_supported_os Linux > > > +_require_scratch > > > + > > > +_scratch_mkfs_sized $((1024 * 1024 * 1024)) >> $seqres.full 2>&1 > > > +_scratch_mount > > > + > > > +test_file="$SCRATCH_MNT/$seq" > > > + > > > +( > > > +ulimit -n $((16 * 1024)) > > > +# ~10000 files on a 1 GB filesystem should be no problem. > > > +for ((i = 1000; i < 10000; i++)); do > > > + eval "exec $i<> \"$test_file\"" && rm "$test_file" || break > > > +done > > > > There's a helper command in src that does exactly this job, e.g. > > > > $here/src/multi_open_unlink -f $SCRATCH_MNT/$seq -n 10000 -s 0 > > > > which creates & unlinks 10000 files and keeps them open for 0 second in > > $SCRATCH_MNT using "$seq" as name prefix. This reduces the test run time > > from 13s to 1s for me. > > > > It's a straightforward change, I'll just update on commit, please let me > > know if you have different thoughts. > > > > Thanks, > > Eryu > > Great, as long as it still reproduces the bug without the fix applied, > that's perfect. Thanks! Yes, I've verified that it still reproduces the bug on btrfs and test passes with the fix(es) applied. Thanks, Eryu