On Tue 05-04-16 12:16:15, Jan Kara wrote:
> Add test which spawns two threads racing to write to file via mmap and
> checks the result. This is mainly interesting to uncover races in DAX
> fault handling.
>
> Signed-off-by: Jan Kara <jack@xxxxxxx>
Ah, I have just noticed that the first version of this patch got merged. So
please just ignore this submission. I will send some updates to this test
and some additional tests later.
Honza
> ---
> src/Makefile | 5 +-
> src/holetest.c | 308 ++++++++++++++++++++++++++++++++++++++++++++++++++
> tests/generic/340 | 58 ++++++++++
> tests/generic/340.out | 55 +++++++++
> tests/generic/group | 1 +
> 5 files changed, 425 insertions(+), 2 deletions(-)
> create mode 100644 src/holetest.c
> create mode 100755 tests/generic/340
> create mode 100644 tests/generic/340.out
>
> diff --git a/src/Makefile b/src/Makefile
> index 31102086a5f6..1bf318bd068b 100644
> --- a/src/Makefile
> +++ b/src/Makefile
> @@ -11,7 +11,8 @@ TARGETS = dirstress fill fill2 getpagesize holes lstat64 \
> devzero feature alloc fault fstest t_access_root \
> godown resvtest writemod makeextents itrash rename \
> multi_open_unlink dmiperf unwritten_sync genhashnames t_holes \
> - t_mmap_writev t_truncate_cmtime dirhash_collide t_rename_overwrite
> + t_mmap_writev t_truncate_cmtime dirhash_collide t_rename_overwrite \
> + holetest
>
> LINUX_TARGETS = xfsctl bstat t_mtab getdevicesize preallo_rw_pattern_reader \
> preallo_rw_pattern_writer ftrunc trunc fs_perms testx looptest \
> @@ -23,7 +24,7 @@ LINUX_TARGETS = xfsctl bstat t_mtab getdevicesize preallo_rw_pattern_reader \
>
> SUBDIRS =
>
> -LLDLIBS = $(LIBATTR) $(LIBHANDLE) $(LIBACL)
> +LLDLIBS = $(LIBATTR) $(LIBHANDLE) $(LIBACL) -lpthread
>
> ifeq ($(HAVE_XLOG_ASSIGN_LSN), true)
> LINUX_TARGETS += loggen
> diff --git a/src/holetest.c b/src/holetest.c
> new file mode 100644
> index 000000000000..661599954e4f
> --- /dev/null
> +++ b/src/holetest.c
> @@ -0,0 +1,308 @@
> +/*
> + * holetest -- test simultaneous page faults on hole-backed pages
> + * Copyright (C) 2015 Hewlett Packard Enterprise Development LP
> + *
> + * 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; either version 2
> + * of the License, or (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will 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 to the Free Software Foundation,
> + * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
> + */
> +
> +
> +/*
> + * holetest
> + *
> + * gcc -Wall -pthread -o holetest holetest.c
> + *
> + * This test tool exercises page faults on hole-y portions of an mmapped
> + * file. The file is created, sized using various methods, mmapped, and
> + * then two threads race to write a marker to different offsets within
> + * each mapped page. Once the threads have finished marking each page,
> + * the pages are checked for the presence of the markers.
> + *
> + * The file is sized four different ways: explicitly zero-filled by the
> + * test, posix_fallocate(), fallocate(), and ftruncate(). The explicit
> + * zero-fill does not really test simultaneous page faults on hole-backed
> + * pages, but rather serves as control of sorts.
> + *
> + * Usage:
> + *
> + * holetest [-f] FILENAME FILESIZEinMB
> + *
> + * Where:
> + *
> + * FILENAME is the name of a non-existent test file to create
> + *
> + * FILESIZEinMB is the desired size of the test file in MiB
> + *
> + * If the test is successful, FILENAME will be unlinked. By default,
> + * if the test detects an error in the page markers, then the test exits
> + * immediately and FILENAME is left. If -f is given, then the test
> + * continues after a marker error and FILENAME is unlinked, but will
> + * still exit with a non-0 status.
> + */
> +
> +#include <stdlib.h>
> +#include <stdio.h>
> +#include <errno.h>
> +#include <inttypes.h>
> +#include <sys/mman.h>
> +#include <fcntl.h>
> +#include <unistd.h>
> +#include <pthread.h>
> +#include <string.h>
> +
> +#define THREADS 2
> +
> +long page_size;
> +long page_offs[THREADS];
> +
> +void *pt_page_marker(void *args)
> +{
> + void **a = args;
> + char *va = (char *)a[0];
> + long npages = (long)a[1];
> + long pgoff = (long)a[2];
> + uint64_t tid = (uint64_t)pthread_self();
> +
> + va += pgoff;
> +
> + /* mark pages */
> + for (; npages > 0; va += page_size, npages--)
> + *(uint64_t *)(va) = tid;
> +
> + return NULL;
> +} /* pt_page_marker() */
> +
> +
> +int test_this(int fd, loff_t sz)
> +{
> + long npages;
> + char *vastart;
> + char *va;
> + void *targs[THREADS][3];
> + pthread_t t[THREADS];
> + uint64_t tid[THREADS];
> + int errcnt;
> + int i;
> +
> + npages = sz / page_size;
> + printf("INFO: sz = %llu\n", (unsigned long long)sz);
> +
> + /* mmap it */
> + vastart = mmap(NULL, sz, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
> + if (MAP_FAILED == vastart) {
> + perror("mmap()");
> + exit(20);
> + }
> +
> + /* prepare the thread args */
> + for (i = 0; i < THREADS; i++) {
> + targs[i][0] = vastart;
> + targs[i][1] = (void *)npages;
> + targs[i][2] = (void *)page_offs[i];
> + }
> +
> + for (i = 0; i < THREADS; i++) {
> + /* start two threads */
> + if (pthread_create(&t[i], NULL, pt_page_marker, &targs[i])) {
> + perror("pthread_create");
> + exit(21);
> + }
> + tid[i] = (uint64_t)t[i];
> + printf("INFO: thread %d created\n", i);
> + }
> +
> + /* wait for them to finish */
> + for (i = 0; i < THREADS; i++)
> + pthread_join(t[i], NULL);
> +
> + /* check markers on each page */
> + errcnt = 0;
> + for (va = vastart; npages > 0; va += page_size, npages--) {
> + for (i = 0; i < THREADS; i++) {
> + if (*(uint64_t*)(va + page_offs[i]) != tid[i]) {
> + printf("ERROR: thread %d, "
> + "offset %08lx, %08lx != %08lx\n", i,
> + (va + page_offs[i] - vastart),
> + *(uint64_t*)(va + page_offs[i]), tid[i]);
> + errcnt += 1;
> + }
> + }
> + }
> +
> + printf("INFO: %d error(s) detected\n", errcnt);
> +
> + munmap(vastart, sz);
> +
> + return errcnt;
> +}
> +
> +int main(int argc, char **argv)
> +{
> + int stoponerror = 1;
> + char *path;
> + loff_t sz;
> + int fd;
> + int errcnt;
> + int toterr = 0;
> + int i, step;
> + char *endch;
> +
> + page_size = getpagesize();
> + step = page_size / THREADS;
> + page_offs[0] = step / 2;
> + for (i = 1; i < THREADS; i++)
> + page_offs[i] = page_offs[i-1] + step;
> +
> + /* process command line */
> + argc--; argv++;
> + /* ignore errors? */
> + if ((argc == 3) && !strcmp(argv[0], "-f")) {
> + stoponerror = 0;
> + argc--;
> + argv++;
> + }
> + /* file name and size */
> + if (argc != 2 || argv[0][0] == '-') {
> + fprintf(stderr, "ERROR: usage: holetest [-f] "
> + "FILENAME FILESIZEinMB\n");
> + exit(1);
> + }
> + path = argv[0];
> + sz = strtol(argv[1], &endch, 10);
> + if (*endch || sz < 1) {
> + fprintf(stderr, "ERROR: bad FILESIZEinMB\n");
> + exit(1);
> + }
> + sz <<= 20;
> +
> + /*
> + * we're going to run our test in several different ways:
> + *
> + * 1. explictly zero-filled
> + * 2. posix_fallocated
> + * 4. ftruncated
> + */
> +
> +
> + /*
> + * explicitly zero-filled
> + */
> + printf("\nINFO: zero-filled test...\n");
> +
> + /* create the file */
> + fd = open(path, O_RDWR | O_EXCL | O_CREAT, 0644);
> + if (fd < 0) {
> + perror(path);
> + exit(2);
> + }
> +
> + /* truncate it to size */
> + if (ftruncate(fd, sz)) {
> + perror("ftruncate()");
> + exit(3);
> + }
> +
> + /* explicitly zero-fill */
> + {
> + char* va = mmap(NULL, sz, PROT_READ | PROT_WRITE,
> + MAP_SHARED, fd, 0);
> + if (MAP_FAILED == va) {
> + perror("mmap()");
> + exit(4);
> + }
> + memset(va, 0, sz);
> + munmap(va, sz);
> + }
> +
> + /* test it */
> + errcnt = test_this(fd, sz);
> + toterr += errcnt;
> + close(fd);
> + if (stoponerror && errcnt > 0)
> + exit(5);
> +
> + /* cleanup */
> + if (unlink(path)) {
> + perror("unlink()");
> + exit(6);
> + }
> +
> +
> + /*
> + * posix_fallocated
> + */
> + printf("\nINFO: posix_fallocate test...\n");
> +
> + /* create the file */
> + fd = open(path, O_RDWR | O_EXCL | O_CREAT, 0644);
> + if (fd < 0) {
> + perror(path);
> + exit(7);
> + }
> +
> + /* fill it to size */
> + if (posix_fallocate(fd, 0, sz)) {
> + perror("posix_fallocate()");
> + exit(8);
> + }
> +
> + /* test it */
> + errcnt = test_this(fd, sz);
> + toterr += errcnt;
> + close(fd);
> + if (stoponerror && errcnt > 0)
> + exit(9);
> +
> + /* cleanup */
> + if (unlink(path)) {
> + perror("unlink()");
> + exit(10);
> + }
> +
> + /*
> + * ftruncated
> + */
> + printf("\nINFO: ftruncate test...\n");
> +
> + /* create the file */
> + fd = open(path, O_RDWR | O_EXCL | O_CREAT, 0644);
> + if (fd < 0) {
> + perror(path);
> + exit(15);
> + }
> +
> + /* truncate it to size */
> + if (ftruncate(fd, sz)) {
> + perror("ftruncate()");
> + exit(16);
> + }
> +
> + /* test it */
> + errcnt = test_this(fd, sz);
> + toterr += errcnt;
> + close(fd);
> + if (stoponerror && errcnt > 0)
> + exit(17);
> +
> + /* cleanup */
> + if (unlink(path)) {
> + perror("unlink()");
> + exit(18);
> + }
> +
> + /* done */
> + if (toterr > 0)
> + exit(19);
> + return 0;
> +}
> diff --git a/tests/generic/340 b/tests/generic/340
> new file mode 100755
> index 000000000000..2ba34eb59724
> --- /dev/null
> +++ b/tests/generic/340
> @@ -0,0 +1,58 @@
> +#! /bin/bash
> +# FSQA Test No. 340
> +#
> +# Test mmap writing races from racing threads
> +#
> +#-----------------------------------------------------------------------
> +#
> +# Copyright (C) 2016 SUSE Linux Products GmbH. All Rights Reserved.
> +# Author: Jan Kara <jack@xxxxxxx>
> +#
> +# 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"
> +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 and checks
> +. ./common/rc
> +
> +# real QA test starts here
> +_supported_fs generic
> +_supported_os Linux
> +_require_scratch
> +_require_test_program "holetest"
> +
> +rm -f $seqres.full
> +
> +_scratch_mkfs >>$seqres.full 2>&1
> +_scratch_mount
> +
> +src/holetest -f $SCRATCH_MNT/testfile 1
> +src/holetest -f $SCRATCH_MNT/testfile 16
> +src/holetest -f $SCRATCH_MNT/testfile 256
> +
> +status=0
> +exit
> diff --git a/tests/generic/340.out b/tests/generic/340.out
> new file mode 100644
> index 000000000000..0eac9ed654dc
> --- /dev/null
> +++ b/tests/generic/340.out
> @@ -0,0 +1,55 @@
> +QA output created by 340
> +
> +INFO: zero-filled test...
> +INFO: sz = 1048576
> +INFO: thread 0 created
> +INFO: thread 1 created
> +INFO: 0 error(s) detected
> +
> +INFO: posix_fallocate test...
> +INFO: sz = 1048576
> +INFO: thread 0 created
> +INFO: thread 1 created
> +INFO: 0 error(s) detected
> +
> +INFO: ftruncate test...
> +INFO: sz = 1048576
> +INFO: thread 0 created
> +INFO: thread 1 created
> +INFO: 0 error(s) detected
> +
> +INFO: zero-filled test...
> +INFO: sz = 16777216
> +INFO: thread 0 created
> +INFO: thread 1 created
> +INFO: 0 error(s) detected
> +
> +INFO: posix_fallocate test...
> +INFO: sz = 16777216
> +INFO: thread 0 created
> +INFO: thread 1 created
> +INFO: 0 error(s) detected
> +
> +INFO: ftruncate test...
> +INFO: sz = 16777216
> +INFO: thread 0 created
> +INFO: thread 1 created
> +INFO: 0 error(s) detected
> +
> +INFO: zero-filled test...
> +INFO: sz = 268435456
> +INFO: thread 0 created
> +INFO: thread 1 created
> +INFO: 0 error(s) detected
> +
> +INFO: posix_fallocate test...
> +INFO: sz = 268435456
> +INFO: thread 0 created
> +INFO: thread 1 created
> +INFO: 0 error(s) detected
> +
> +INFO: ftruncate test...
> +INFO: sz = 268435456
> +INFO: thread 0 created
> +INFO: thread 1 created
> +INFO: 0 error(s) detected
> diff --git a/tests/generic/group b/tests/generic/group
> index 727648c68785..d0ca807b3695 100644
> --- a/tests/generic/group
> +++ b/tests/generic/group
> @@ -340,3 +340,4 @@
> 335 auto quick metadata
> 336 auto quick metadata
> 337 auto quick metadata
> +340 auto
> --
> 2.6.2
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
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