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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5289EC433EF for ; Tue, 24 May 2022 08:29:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229967AbiEXI3c (ORCPT ); Tue, 24 May 2022 04:29:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42476 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230030AbiEXI3b (ORCPT ); Tue, 24 May 2022 04:29:31 -0400 Received: from mail-qv1-xf2a.google.com (mail-qv1-xf2a.google.com [IPv6:2607:f8b0:4864:20::f2a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D81AC692AA for ; Tue, 24 May 2022 01:29:29 -0700 (PDT) Received: by mail-qv1-xf2a.google.com with SMTP id cv1so1590490qvb.5 for ; Tue, 24 May 2022 01:29:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=bVB3fULD0gEch6Ti0Y/oscbpiL4zTe6IpkkNrX8rFQk=; b=VDozAKtxyvh/JnF/4yM7eS0QXjuyr612obbkB5BcD9uv3tttzRXVAO7OLAgzF/6GNv Z+9y5Zw6B+k91Z5Iei1+/4Y6A/mryoPhr7NRJcy+KyU3LT093NSaPObPtqMK3ioEOUmX 812o2hPGmpH2CxxgwcN4gT5KecRoWsp5l1N00VH6rYL8vvxrFgdyd0QTAMVNfuIbGaJm 89jeyPYF1HgNwQCtaBCElVKDGL6kia+O6F6UC+oRI8fM3J47LH0XhUm4wT1mUCOlsoyR LEMc16z7dSpiqxHfClMgiOuUqebwQEHR/nIIJZGV3TpOGcSPHIw1CXwk0ADGDPtzJxi3 bfAw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=bVB3fULD0gEch6Ti0Y/oscbpiL4zTe6IpkkNrX8rFQk=; b=wMWIH8igTw6/RME2fxogNgu0JGtWTq0GmMl+AxjfEeDDNvgrSfRdBIydngc9VRNti7 O7YToegA2FeSCRC3e+t5SMnAkRjXPS/Iqsfzdd22j5LVAGRHBbuBJHH4XUL0wVS+SFS6 rupA0mqA9/QOnZT+y6+Dk1OhF9O+4WaohqNTir7wInM0L8F7qv+mTaU1uofhAm2E4/av RVou9qqMuEgEfCoCeJ0l1nzkvUb2gHKKorB048BUB82bNUKEEM78xZny+oOq7EErALVA 94aZhX+bqDp527jEWQKxKpX9qbI8KjoHh/TVnwWIPsOL0lLf0r3rkD2uelywJG+MsOLS WHQQ== X-Gm-Message-State: AOAM5335Z4Rl9X8VbG1ov7K9Ot65devX9z1ramGemSjXWxRzJAgoQcro +2QesRJGj0bei0gLWSc7zoaRevggtDW+Vjl6cN9xb2Wk X-Google-Smtp-Source: ABdhPJwaTviDH93tmsfPcLgXOU2ZTQbDCbU45gSbUrJRv038IDecWsZHGwp1i61BmwKYGx7uZq/oO5lbbL2VgRzY+3k= X-Received: by 2002:a05:6214:1c83:b0:443:6749:51f8 with SMTP id ib3-20020a0562141c8300b00443674951f8mr20163179qvb.74.1653380968988; Tue, 24 May 2022 01:29:28 -0700 (PDT) MIME-Version: 1.0 References: <20220524073411.1943480-1-david@fromorbit.com> In-Reply-To: <20220524073411.1943480-1-david@fromorbit.com> From: Amir Goldstein Date: Tue, 24 May 2022 11:29:17 +0300 Message-ID: Subject: Re: [RFC PATCH 0/8] fstests: _cleanup() overrides are a mess To: Dave Chinner Cc: fstests Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: fstests@vger.kernel.org On Tue, May 24, 2022 at 11:01 AM Dave Chinner wrote: > > Hi folks, > > I pulled on a string a couple of days ago, and it got out of > control. It all started when I went to kill a test with ctrl-c and > it, once again, left background processes running that I had to hunt > down and kill manually. > > I then started looking a why this keeps happening, and realised that > the way we clean up on test completion is messy, inconsistent and > frequently buggy. So I started cleaning it all up, starting with the > tests/xfs directory because I saw a lot of low hanging fruit there. > > Essentially, we use _cleanup() functions as a way of overriding the > default trap handler we install in _begin_fstest(). Rather than > register a new handler, we just redefine the common cleanup function > and re-implement it (poorly) in every test that does an override. > Often these overrides are completely unnecessary - I think I reduced > the total number of overrides in tests/xfs by ~30% (~190 -> ~125), > and I reudced the number of *unique overrides by a lot more than > that. > That looks like an awesome improvement! > The method for overriding changes to be "stacked cleanups" rather > than "duplicated cleanups". That is, tests no longer open code: > > cd / > rm -rf $tmp.* > > THis is what common/preamble::_cleanup() does. We should call that > function to do this. Hence if we have a local cleanup that we need > to do, it becomes: > > local_cleanup() > { > rm -f $testfile > _cleanup > } > _register_cleanup local_cleanup While removing boilerplate code, we had better not create another boilerplate. Instead of expecting test writers to always call _cleanup if we always want _cleanup to be called we can always implicitly chain it in _register_cleanup(): --- a/common/preamble +++ b/common/preamble @@ -20,7 +20,7 @@ _register_cleanup() shift test -n "$cleanup" && cleanup="${cleanup}; " - trap "${cleanup}exit \$status" EXIT HUP INT QUIT TERM $* + trap "${cleanup}_cleanup; exit \$status" EXIT HUP INT QUIT TERM $* } # Prepare to run a fstest by initializing the required global variables to @@ -46,7 +46,7 @@ _begin_fstest() tmp=/tmp/$$ status=1 # failure is the default! - _register_cleanup _cleanup + _register_cleanup . ./common/rc It could be a bit weird for tests that call _register_cleanup _cleanup But you removed most of those in the SIGBUS patch and even if they do exists, _cleanup() is re-entrant. > > While this looks more verbose, it means we can actually reuse the > same cleanup function across lots of tests. > > A large number of xfsdump tests were all using the same override > cleanup function to call _cleanup_dump. These are all changed to: > > . ./common/dump > _register_cleanup _cleanup_dump > > and _cleanup_dump stacks like this: > > _cleanup_dump() > { > #do xfsdump cleanup stuff > > _cleanup > } > > and we don't need to do anything else. There is one xfsdump test > that needs it's own cleanup. It stacks like this: > > local_cleanup() > { > rm -f $testfile > _cleanup_dump > } > _register_cleanup local_cleanup > > All the tests that run fsstress in the background now have a common > cleanup function that kills fsstress processes defined in > common/preamble. They just do: > > _register_cleanup _cleanup_fsstress > > And now every test that puts fsstress in the background behaves > correctly and kills all the background fsstree processes when > interrupted. > > The conversion is by no means complete. I've named the local cleanup > functions by what they do so we can go back and derive commonality > between them. The number of different variations on tearing down > loops devices is crazy, and half of them are buggy. I haven't worked > through these yet, so you'll see lots of tests with: > > _loop_cleanup() > { > ...... > _cleanup > } > _register_cleanup _loop_cleanup > > That have similar but different ways of cleaning up loop devices. > > I also added a _no_cleanup() function, as there are a large number > of xfs fuzzer tests that want to leave a warm corpse behind so that > debugging what just happened is easy. > > I also added BUS to the default signal trap set - well over a 100 > tests in tests/xfs had a line like: > > _register_cleanup "_cleanup" BUS > > just to add BUS signals to the set that would cause the cleanup > function to run. Just make it the default! > > Overall, this significantly reduces the amount of boiler plate in > tests, and sets us down the path of common cleanup functions that > tests may not even need to define. e.g. just including > ./common/dmflakey registers the _cleanup_dmflakey() trap that will > do all the necessary cleanup when the test exists. This makes the > tests simpler, more robust and reduces the maintenance burden of > over 1700 individual tests.... > > I won't put the full diffstat in this mail, but the benefits should > be clean from the summary: > > 360 files changed, 420 insertions(+), 1781 deletions(-) > > I've lost count of the number of test bugs I killed in removing > all this code, and that's largely just in the tests/xfs directory. > So before I go spend another couple of days on converting the rest > of fstests, I figured I better make sure everyone is OK with these > changes. > > Thoughts, comments? > Thank you for taking this on! Amir.