From patchwork Mon May 31 15:26:04 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andreas Gruenbacher X-Patchwork-Id: 12289609 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=-16.1 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 B125DC47083 for ; Mon, 31 May 2021 15:29:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 96B8E6124C for ; Mon, 31 May 2021 15:29:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234252AbhEaPb3 (ORCPT ); Mon, 31 May 2021 11:31:29 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:58004 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234706AbhEaP2B (ORCPT ); Mon, 31 May 2021 11:28:01 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1622474769; 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=8Alh5Zv/NoNG4oFH7Qf11lJlQ/a2KnmmczpqQFIkCrQ=; b=TCvMuNEee4wtZ/peUVUP6iclqWigLyf6zleaz4bN97vPyj9Ib6UV4i9nK4SSCaxTVdDNXn cLJIjRIxjqjH6bklO6lAD2nYElvpJZTo/zeugnXUY15SLJcHfBe9k7gE86ZaKW5KTwhmrs SsTBLj42RPsc6OW8BFZe1QX8i9gSeIU= 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-518-RoAtoXdiNHywtxPVzwv2kw-1; Mon, 31 May 2021 11:26:07 -0400 X-MC-Unique: RoAtoXdiNHywtxPVzwv2kw-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 2AF28107ACC7 for ; Mon, 31 May 2021 15:26:07 +0000 (UTC) Received: from max.com (unknown [10.40.192.80]) by smtp.corp.redhat.com (Postfix) with ESMTP id 64D805D9C0; Mon, 31 May 2021 15:26:06 +0000 (UTC) From: Andreas Gruenbacher To: fstests@vger.kernel.org Cc: Andreas Gruenbacher Subject: [PATCH] generic/639: Test page faults during read and write Date: Mon, 31 May 2021 17:26:04 +0200 Message-Id: <20210531152604.240462-1-agruenba@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Precedence: bulk List-ID: X-Mailing-List: fstests@vger.kernel.org Some filesystems have problems when the buffer passed to read or write is memory-mapped to the file being read from or written to and the buffer is faulted in during the read or write. (That's probably not a recommended use case, but it should work nevertheless.) Signed-off-by: Andreas Gruenbacher --- src/Makefile | 2 +- src/mmap-rw-fault.c | 169 ++++++++++++++++++++++++++++++++++++++++++ tests/generic/639 | 40 ++++++++++ tests/generic/639.out | 2 + tests/generic/group | 1 + 5 files changed, 213 insertions(+), 1 deletion(-) create mode 100644 src/mmap-rw-fault.c create mode 100755 tests/generic/639 create mode 100644 tests/generic/639.out diff --git a/src/Makefile b/src/Makefile index 1279e4b9..6e3871b9 100644 --- a/src/Makefile +++ b/src/Makefile @@ -18,7 +18,7 @@ TARGETS = dirstress fill fill2 getpagesize holes lstat64 \ t_ext4_dax_journal_corruption t_ext4_dax_inline_corruption \ t_ofd_locks t_mmap_collision mmap-write-concurrent \ t_get_file_time t_create_short_dirs t_create_long_dirs t_enospc \ - t_mmap_writev_overlap + t_mmap_writev_overlap mmap-rw-fault 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/mmap-rw-fault.c b/src/mmap-rw-fault.c new file mode 100644 index 00000000..31778769 --- /dev/null +++ b/src/mmap-rw-fault.c @@ -0,0 +1,169 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Trigger mmap page faults in the same file during pread and pwrite. + * Copyright (C) 2021 Red Hat, Inc. All Rights Reserved. + * Written by Andreas Gruenbacher + */ + +#ifndef _GNU_SOURCE +#define _GNU_SOURCE /* to get definition of O_DIRECT flag. */ +#endif + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +char *filename; +unsigned int page_size; +void *page; +char *addr; +int fd; +ssize_t ret; + +/* + * Leave a hole at the beginning of the test file and initialize a block of + * @page_size bytes at offset @page_size to @c. Then, reopen the file and + * mmap the first two pages. + */ +void init(char c, int flags) +{ + fd = open(filename, O_CREAT | O_TRUNC | O_WRONLY | O_DIRECT, 0666); + if (fd == -1) + goto fail; + memset(page, c, page_size); + ret = pwrite(fd, page, page_size, page_size); + if (ret != page_size) + goto fail; + if (close(fd)) + goto fail; + + fd = open(filename, flags); + if (fd == -1) + goto fail; + addr = mmap(NULL, 2 * page_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0); + if (addr == MAP_FAILED) + err(1, NULL); + return; + +fail: + err(1, "%s", filename); +} + +void done(void) +{ + if (fsync(fd)) + goto fail; + if (close(fd)) + goto fail; + return; + +fail: + err(1, "%s", filename); +} + +static ssize_t do_read(int fd, void *buf, size_t count, off_t offset) +{ + ssize_t count2 = 0, ret; + + do { + ret = pread(fd, buf, count, offset); + if (ret == -1) { + if (errno == EINTR) + continue; + break; + } + if (ret == 0) + break; + count2 += ret; + buf += ret; + count -= ret; + } while (count); + return count2; +} + +static ssize_t do_write(int fd, const void *buf, size_t count, off_t offset) +{ + ssize_t count2 = 0, ret; + + do { + ret = pwrite(fd, buf, count, offset); + if (ret == -1) { + if (errno == EINTR) + continue; + break; + } + if (ret == 0) + break; + count2 += ret; + buf += ret; + count -= ret; + } while (count); + return count2; +} + +int main(int argc, char *argv[]) +{ + if (argc != 2) + errx(1, "no test filename argument given"); + filename = argv[1]; + + page_size = ret = sysconf(_SC_PAGE_SIZE); + if (ret == -1) + err(1, NULL); + + ret = posix_memalign(&page, page_size, page_size); + if (ret) { + errno = ENOMEM; + err(1, NULL); + } + + /* + * Make sure page faults during pread are handled correctly. + */ + init('a', O_RDWR); + ret = do_read(fd, addr, page_size, page_size); + if (ret != page_size) + err(1, "pread %s: %ld != %u", filename, ret, page_size); + if (memcmp(addr, page, page_size)) + errx(1, "pread is broken"); + done(); + + init('b', O_RDWR | O_DIRECT); + ret = do_read(fd, addr, page_size, page_size); + if (ret != page_size) + err(1, "pread %s (O_DIRECT): %ld != %u", filename, ret, page_size); + if (memcmp(addr, page, page_size)) + errx(1, "pread (D_DIRECT) is broken"); + done(); + + /* + * Make sure page faults during pwrite are handled correctly. + */ + init('c', O_RDWR); + ret = do_write(fd, addr + page_size, page_size, 0); + if (ret != page_size) + err(1, "pwrite %s: %ld != %u", filename, ret, page_size); + if (memcmp(addr, page, page_size)) + errx(1, "pwrite is broken"); + done(); + + init('d', O_RDWR | O_DIRECT); + ret = do_write(fd, addr + page_size, page_size, 0); + if (ret != page_size) + err(1, "pwrite %s (O_DIRECT): %ld != %u", filename, ret, page_size); + if (memcmp(addr, page, page_size)) + errx(1, "pwrite (O_DIRECT) is broken"); + done(); + + if (unlink(filename)) + err(1, "unlink %s", filename); + + return 0; +} diff --git a/tests/generic/639 b/tests/generic/639 new file mode 100755 index 00000000..4406be98 --- /dev/null +++ b/tests/generic/639 @@ -0,0 +1,40 @@ +#! /bin/bash +# SPDX-License-Identifier: GPL-2.0 +# Copyright (c) 2021 Red Hat, Inc. All Rights Reserved. +# +# FS QA Test 639 +# +# Trigger mmap page faults in the same file during pread and pwrite +# +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 $tmp.* +} + +# get standard environment, filters and checks +. ./common/rc +. ./common/filter + +# real QA test starts here + +# Modify as appropriate. +_supported_fs generic +_require_test +_require_test_program mmap-rw-fault + +$here/src/mmap-rw-fault $TEST_DIR/mmap-rw-fault.tmp 2>&1 + +# success, all done +echo "Silence is golden" +status=0 +exit diff --git a/tests/generic/639.out b/tests/generic/639.out new file mode 100644 index 00000000..62c66537 --- /dev/null +++ b/tests/generic/639.out @@ -0,0 +1,2 @@ +QA output created by 639 +Silence is golden diff --git a/tests/generic/group b/tests/generic/group index 9a636b23..d6f11cda 100644 --- a/tests/generic/group +++ b/tests/generic/group @@ -641,3 +641,4 @@ 636 auto quick swap 637 auto quick dir 638 auto quick rw +639 auto