From mboxrd@z Thu Jan 1 00:00:00 1970 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=-16.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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 9684AC432BE for ; Fri, 27 Aug 2021 16:17:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 70C4560FC4 for ; Fri, 27 Aug 2021 16:17:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234311AbhH0QR6 (ORCPT ); Fri, 27 Aug 2021 12:17:58 -0400 Received: from mail.kernel.org ([198.145.29.99]:58850 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234192AbhH0QR6 (ORCPT ); Fri, 27 Aug 2021 12:17:58 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 3C51760E78; Fri, 27 Aug 2021 16:17:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1630081029; bh=6cbHtyAS/jG4nGHwxDi7coDuAwFVAG09UuZ8b8OUBkI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=RSumjVC0XBYdvvDF4oVy0assKK1ZEjd8VpHWExZt2TJIlGnyGOsc+WzfCzzqCOPys smMHUrng0UXUgr5bLnyGpCES8HAu42aliZcRU3j5Kz6GJaaQXZeo/BSNS+wvEmQFwx 2NIwvX8UGf0Bq/2CsCh0CMXm1RyzSSnwu9Lu56HP2Pr+qD9kkJ45fDWRRDJeibWDUV u1EQmwYHR+fxOUXmH21lpoJsTEfWFiAapIxGgT6SAFIU6zUZT9li2lJcuupPFHtcFJ +/HI+TWbntr3g7luQbf1qLq3O2Pz5N41uH3fT8WV8tdftHUwS7lZTqvfG5nMIuwEX7 tBYZ6VB6aJ4XQ== Date: Fri, 27 Aug 2021 09:17:08 -0700 From: "Darrick J. Wong" To: Andreas Gruenbacher Cc: fstests@vger.kernel.org Subject: Re: [PATCH] generic/646: Test page faults during read and write Message-ID: <20210827161708.GL12612@magnolia> References: <20210827150603.1724638-1-agruenba@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210827150603.1724638-1-agruenba@redhat.com> Precedence: bulk List-ID: X-Mailing-List: fstests@vger.kernel.org On Fri, Aug 27, 2021 at 05:06:03PM +0200, Andreas Gruenbacher wrote: > Here's an update of a test case I'm trying to get merged since May. > Please have a look; I'm tired of dragging this along. > > Thanks, > Andreas > > -- > > 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 needs to be faulted in during the read or write. That's not > common, but filesystems are still required to cope with it, and if they > fail this test, then they will also fail more complex scenarios that > involve multiple files. > > Signed-off-by: Andreas Gruenbacher > --- > src/Makefile | 2 +- > src/mmap-rw-fault.c | 176 ++++++++++++++++++++++++++++++++++++++++++ > tests/generic/646 | 27 +++++++ > tests/generic/646.out | 2 + > 4 files changed, 206 insertions(+), 1 deletion(-) > create mode 100644 src/mmap-rw-fault.c > create mode 100755 tests/generic/646 > create mode 100644 tests/generic/646.out > > diff --git a/src/Makefile b/src/Makefile > index 884bd86a..25ab061d 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 checkpoint_journal > + t_mmap_writev_overlap checkpoint_journal 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..244d2cb6 > --- /dev/null > +++ b/src/mmap-rw-fault.c The generated binary needs a gitignore entry. > @@ -0,0 +1,176 @@ > +/* Trigger mmap page faults in the same file during pread and pwrite. */ Needs a SPDX header and a copyright statement. > + > +#ifndef _GNU_SOURCE > +#define _GNU_SOURCE /* to get definition of O_DIRECT flag. */ > +#endif > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +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. > + */ These test reading from page 1 into (mmap) page 0, right? > + 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. > + */ ...and writing from (mmap) page 1 into page 0? > + 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(); > + > + /* > + * Reading from a hole takes a different code path in the kernel. > + */ ...and finally we test direct reading from page 0 into (mmap) page 0? If that's correct, then this looks good to me, modulo the license nit at the top. > + init('e', O_RDWR | O_DIRECT); > + ret = do_read(fd, addr, page_size, 0); > + if (ret != page_size) > + err(1, "pread %s (O_DIRECT) from hole: %ld != %u", filename, ret, page_size); > + memset(page, 0, page_size); > + if (memcmp(addr, page, page_size)) > + errx(1, "pread (D_DIRECT) from hole is broken"); > + done(); > + > + if (unlink(filename)) > + err(1, "unlink %s", filename); > + > + return 0; > +} > diff --git a/tests/generic/646 b/tests/generic/646 > new file mode 100755 > index 00000000..57d8c13d > --- /dev/null > +++ b/tests/generic/646 > @@ -0,0 +1,27 @@ > +#! /bin/bash > +# SPDX-License-Identifier: GPL-2.0 > +# Copyright (c) 2021 Red Hat, Inc. All Rights Reserved. > +# > +# FS QA Test 646 > +# > +# Trigger mmap page faults in the same file during pread and pwrite > +# > +. ./common/preamble > +_begin_fstest auto quick > + > +# get standard environment, filters and checks > +. ./common/rc > +. ./common/filter > + > +# real QA test starts here > + > +_supported_fs generic > +_require_test > +_require_test_program mmap-rw-fault > + > +echo "Silence is golden" > + > +$here/src/mmap-rw-fault $TEST_DIR/mmap-rw-fault.tmp _cleanup should clean up the tempfile if the C program crashes, right? Or use O_TMPFILE and let the kernel clean up the file for you. --D > + > +status=$? > +exit > diff --git a/tests/generic/646.out b/tests/generic/646.out > new file mode 100644 > index 00000000..8357006e > --- /dev/null > +++ b/tests/generic/646.out > @@ -0,0 +1,2 @@ > +QA output created by 646 > +Silence is golden > -- > 2.26.3 >