From patchwork Thu May 25 13:49:47 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Kara X-Patchwork-Id: 766971 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3wYVy00Zgvz9s0g for ; Thu, 25 May 2017 23:50:00 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S969558AbdEYNt7 (ORCPT ); Thu, 25 May 2017 09:49:59 -0400 Received: from mx2.suse.de ([195.135.220.15]:33280 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S969231AbdEYNt4 (ORCPT ); Thu, 25 May 2017 09:49:56 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id CF386AAB6; Thu, 25 May 2017 13:49:54 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id 640AF1E308E; Thu, 25 May 2017 15:49:53 +0200 (CEST) From: Jan Kara To: Cc: Michael Zimmer , , Eryu Guan , Jan Kara Subject: [PATCH] generic: Add regression test for tail page zeroing Date: Thu, 25 May 2017 15:49:47 +0200 Message-Id: <20170525134947.15130-1-jack@suse.cz> X-Mailer: git-send-email 2.12.0 Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org Add test checking for a race in ext4 writeback that could result in zeroing too much from the tail page during writeback. Signed-off-by: Jan Kara --- src/Makefile | 2 +- src/t_mmap_fallocate.c | 61 ++++++++++++++++++++++++++++++++++++++++ tests/generic/438 | 75 ++++++++++++++++++++++++++++++++++++++++++++++++++ tests/generic/438.out | 2 ++ tests/generic/group | 1 + 5 files changed, 140 insertions(+), 1 deletion(-) create mode 100644 src/t_mmap_fallocate.c create mode 100755 tests/generic/438 create mode 100644 tests/generic/438.out diff --git a/src/Makefile b/src/Makefile index 47246622ce7f..adbfd286fe89 100644 --- a/src/Makefile +++ b/src/Makefile @@ -13,7 +13,7 @@ TARGETS = dirstress fill fill2 getpagesize holes lstat64 \ multi_open_unlink dmiperf unwritten_sync genhashnames t_holes \ t_mmap_writev t_truncate_cmtime dirhash_collide t_rename_overwrite \ holetest t_truncate_self t_mmap_dio af_unix t_mmap_stale_pmd \ - t_mmap_cow_race + t_mmap_cow_race t_mmap_fallocate LINUX_TARGETS = xfsctl bstat t_mtab getdevicesize preallo_rw_pattern_reader \ preallo_rw_pattern_writer ftrunc trunc fs_perms testx looptest \ diff --git a/src/t_mmap_fallocate.c b/src/t_mmap_fallocate.c new file mode 100644 index 000000000000..fd69fb0ae833 --- /dev/null +++ b/src/t_mmap_fallocate.c @@ -0,0 +1,61 @@ +#include +#include +#include +#include +#include + +int main(int argc, char **argv) +{ + int fd; + char *buf; + size_t fsize, i; + + if (argc != 3) { + fputs("Usage: mmap_fallocate \n", stderr); + exit(1); + } + + fsize = strtol(argv[2], NULL, 10); + if (fsize <= 0) { + fprintf(stderr, "Invalid file size: %s\n", argv[2]); + exit(1); + } + fsize <<= 20; + + fd = open(argv[1], O_RDWR | O_CREAT | O_TRUNC, 0644); + if (fd < 0) { + perror("Cannot open file"); + exit(1); + } + + buf = mmap(NULL, fsize, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0); + if (buf == MAP_FAILED) { + perror("Cannot memory map"); + exit(1); + } + + for (i = 0; i < fsize; i++) { + if (posix_fallocate(fd, i, 1) != 0) { + perror("Cannot fallocate"); + exit(1); + } + buf[i] = 0x78; + + if (buf[i] != 0x78) { + fprintf(stderr, + "Value not written correctly (off=%lu)\n", + (unsigned long)i); + exit(1); + } + } + + for (i = 0; i < fsize; i++) { + if (buf[i] != 0x78) { + fprintf(stderr, "Value has been modified (off=%lu)\n", + (unsigned long)i); + exit(1); + } + } + + return 0; +} diff --git a/tests/generic/438 b/tests/generic/438 new file mode 100755 index 000000000000..d935ac0362ad --- /dev/null +++ b/tests/generic/438 @@ -0,0 +1,75 @@ +#! /bin/bash +# FS QA Test 438 +# +# This is a regression test for kernel patch +# "ext4: Fix data corruption for mmap writes" +# +# The problem this test checks for is when too much is zeroed in the tail +# page that gets written out just while the file gets extended and written +# to through mmap. +# +# Based on test program by Michael Zimmer +# +#----------------------------------------------------------------------- +# Copyright (c) 2017 SUSE. 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.* +} + +# get standard environment, filters and checks +. ./common/rc +. ./common/filter + +# remove previous $seqres.full before test +rm -f $seqres.full + +# Modify as appropriate. +_supported_fs generic +_supported_os Linux +_require_test +_require_test_program "t_mmap_fallocate" + +# real QA test starts here +FILE=$TEST_DIR/testfile_fallocate +# Make sure file exists +echo >$FILE +# Force frequent writeback of the file +while true; do fsync $FILE; done & +SYNCPID=$! + +# Run the test +src/t_mmap_fallocate $FILE 10 && echo "Silence is golden" + +kill $SYNCPID +wait + +# success, all done +status=0 +exit diff --git a/tests/generic/438.out b/tests/generic/438.out new file mode 100644 index 000000000000..4968f4d7f691 --- /dev/null +++ b/tests/generic/438.out @@ -0,0 +1,2 @@ +QA output created by 438 +Silence is golden diff --git a/tests/generic/group b/tests/generic/group index 438c299030f2..d88f5bb44514 100644 --- a/tests/generic/group +++ b/tests/generic/group @@ -440,3 +440,4 @@ 435 auto encrypt 436 auto quick rw 437 auto quick +438 auto quick