From patchwork Thu Apr 22 15:31:47 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Boyang Xue X-Patchwork-Id: 12218681 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=-15.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 D4589C433B4 for ; Thu, 22 Apr 2021 15:32:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 94B6E61425 for ; Thu, 22 Apr 2021 15:32:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232844AbhDVPda (ORCPT ); Thu, 22 Apr 2021 11:33:30 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:31522 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230005AbhDVPda (ORCPT ); Thu, 22 Apr 2021 11:33:30 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1619105574; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=hKh8/U8kruBaAUtSPVecJvcAeQIfmoA5va9VPx1yGzM=; b=LvmNCijbJ8TY9pNu4ivwS2+bo/ZFAzq0GF6xUqnIkQdsAcViDg9EZ+GtgcwLeVJGSlyv1q 67F0Qus/u2MPq3WDOwgpvQVoz4F6t+PaQu9HnGhLzvXFiAk5qx+aop4BF93jjQqrCarYre 9STniIDL3Ucxvuea4iC1WplhT0krRSs= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-198-Gza9xX1rM4iFCSyV7gAf2g-1; Thu, 22 Apr 2021 11:32:34 -0400 X-MC-Unique: Gza9xX1rM4iFCSyV7gAf2g-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id BF06E8189E3 for ; Thu, 22 Apr 2021 15:31:55 +0000 (UTC) Received: from localhost.localdomain (bootp-73-5-251.rhts.eng.pek2.redhat.com [10.73.5.251]) by smtp.corp.redhat.com (Postfix) with ESMTP id DD97F19C45; Thu, 22 Apr 2021 15:31:53 +0000 (UTC) From: bxue@redhat.com To: fstests@vger.kernel.org Cc: bfoster@redhat.com, minlei@redhat.com, lczerner@redhat.com, Boyang Xue Subject: [PATCH v2] generic/563: tolerate small reads in "write -> read/write" sub-test Date: Thu, 22 Apr 2021 23:31:47 +0800 Message-Id: <20210422153147.1049666-1-bxue@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Precedence: bulk List-ID: X-Mailing-List: fstests@vger.kernel.org From: Boyang Xue On ext2/ext3, it's expected that several single block metadata reads can occur when writing to file in the same cgroup (the stack is like below[1]). The purpose of the "write -> read/write" subtest is to make sure the larger pwrite is accounted to the correct cgroup, not necessarily enforce that zero bytes are read in service of the write. This patch fixes the sub-test in order to tolerate small reads in 1st cgroup. [1] Callchain of the read: @ext3_read_bio[ submit_bio+1 submit_bh_wbc+365 ext4_read_bh+72 ext4_get_branch+201 ext4_ind_map_blocks+382 ext4_map_blocks+295 _ext4_get_block+170 __block_write_begin_int+328 ext4_write_begin+541 generic_perform_write+213 ext4_buffered_write_iter+167 new_sync_write+345 vfs_write+438 __x64_sys_pwrite64+140 do_syscall_64+51 entry_SYSCALL_64_after_hwframe+68 , 5793, 12]: 3 Signed-off-by: Boyang Xue --- Hi, This patch fix the "write -> read/write" sub-test in order to tolerate small reads in service of the write (like read metadata). Change from v1: (1) More details in commit log, including example call stack (2) Set the fixed tolerance value to 33792 for accuracy (3) Update percentage tolerance value to fixed value 0, where doesn't fail the test Tested pass on ext2/ext3/ext4 x 1k/2k/4k blksize. Thanks, Boyang tests/generic/563 | 20 +++++++++++++------- 1 file changed, 13 insertions(+), 7 deletions(-) diff --git a/tests/generic/563 b/tests/generic/563 index b113eacf..44394b4b 100755 --- a/tests/generic/563 +++ b/tests/generic/563 @@ -60,6 +60,8 @@ check_cg() cgname=$(basename $cgroot) expectedread=$2 expectedwrite=$3 + readtol=$4 + writetol=$5 rbytes=0 wbytes=0 @@ -71,8 +73,8 @@ check_cg() awk -F = '{ print $2 }'` fi - _within_tolerance "read" $rbytes $expectedread 5% -v - _within_tolerance "write" $wbytes $expectedwrite 5% -v + _within_tolerance "read" $rbytes $expectedread $readtol -v + _within_tolerance "write" $wbytes $expectedwrite $writetol -v } # Move current process to another cgroup. @@ -113,7 +115,7 @@ $XFS_IO_PROG -c "pread 0 $iosize" -c "pwrite 0 $iosize" -c fsync \ $SCRATCH_MNT/file >> $seqres.full 2>&1 switch_cg $cgdir $XFS_IO_PROG -c fsync $SCRATCH_MNT/file -check_cg $cgdir/$seq-cg $iosize $iosize +check_cg $cgdir/$seq-cg $iosize $iosize 5% 5% # Write from one cgroup then read and write from a second. Writes are charged to # the first group and nothing to the second. @@ -126,8 +128,12 @@ $XFS_IO_PROG -c "pread 0 $iosize" -c "pwrite 0 $iosize" $SCRATCH_MNT/file \ >> $seqres.full 2>&1 switch_cg $cgdir $XFS_IO_PROG -c fsync $SCRATCH_MNT/file -check_cg $cgdir/$seq-cg 0 $iosize -check_cg $cgdir/$seq-cg-2 0 0 +# Use a fixed value tolerance for the expected value of zero here +# because filesystems might perform a small number of metadata reads to +# complete the write. On ext2/3 with 1k block size, the read bytes is +# as large as 33792. +check_cg $cgdir/$seq-cg 0 $iosize 33792 0 +check_cg $cgdir/$seq-cg-2 0 0 0 0 # Read from one cgroup, read & write from a second. Both reads and writes are # charged to the first group and nothing to the second. @@ -140,8 +146,8 @@ $XFS_IO_PROG -c "pread 0 $iosize" -c "pwrite 0 $iosize" $SCRATCH_MNT/file \ >> $seqres.full 2>&1 switch_cg $cgdir $XFS_IO_PROG -c fsync $SCRATCH_MNT/file -check_cg $cgdir/$seq-cg $iosize $iosize -check_cg $cgdir/$seq-cg-2 0 0 +check_cg $cgdir/$seq-cg $iosize $iosize 5% 0 +check_cg $cgdir/$seq-cg-2 0 0 0 0 echo "-io" > $cgdir/cgroup.subtree_control || _fail "subtree control"