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=-8.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY, URIBL_BLOCKED,USER_AGENT_SANE_1 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 22B97C11D00 for ; Fri, 21 Feb 2020 00:41:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E0233207FD for ; Fri, 21 Feb 2020 00:41:29 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="CuNROqWh" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729439AbgBUAl3 (ORCPT ); Thu, 20 Feb 2020 19:41:29 -0500 Received: from userp2120.oracle.com ([156.151.31.85]:53580 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729365AbgBUAl3 (ORCPT ); Thu, 20 Feb 2020 19:41:29 -0500 Received: from pps.filterd (userp2120.oracle.com [127.0.0.1]) by userp2120.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 01L0YElK169433; Fri, 21 Feb 2020 00:41:23 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=date : from : to : cc : subject : message-id : references : mime-version : content-type : in-reply-to; s=corp-2020-01-29; bh=aa1zkPjM74iK2ByfhK4MusknhhehHE7ZZ2VJfd99/Rg=; b=CuNROqWhL9LYrbCtwAd+FGg0lthtx9+HSEnQA3/MGOF0MrDiM0kZTkVz7HkR+4fwvIqk ZbKiU6eSy/fC+0aZoqsVWxgvnrcayQM2O4Vb++VtrT1ucSto0aY6eqdYBjP3G8u8Og7T B20tsyCX9cD70NXcOdRidopY/2f18q7rQxcKr87jeXdardTIeRsiu9KiswRL1ejuwlJ0 lUO7fJ3a7OGg3C5G2AKnPNY15JVjFqh8KnKwAWgk5mpwgutkF77t2oe86IkonC2HIR40 OIVta6PR37Ifu5j8m453VU+9nbZE09sUnPlhjdx4nQ50Q8e3FTcaafuvaik7tPLcIaMF 7g== Received: from userp3020.oracle.com (userp3020.oracle.com [156.151.31.79]) by userp2120.oracle.com with ESMTP id 2y8ud1dbwh-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 21 Feb 2020 00:41:23 +0000 Received: from pps.filterd (userp3020.oracle.com [127.0.0.1]) by userp3020.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 01L0Vgbu129113; Fri, 21 Feb 2020 00:39:22 GMT Received: from userv0122.oracle.com (userv0122.oracle.com [156.151.31.75]) by userp3020.oracle.com with ESMTP id 2y8ud545yr-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 21 Feb 2020 00:39:22 +0000 Received: from abhmp0011.oracle.com (abhmp0011.oracle.com [141.146.116.17]) by userv0122.oracle.com (8.14.4/8.14.4) with ESMTP id 01L0dLdT028308; Fri, 21 Feb 2020 00:39:21 GMT Received: from localhost (/10.145.178.17) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 20 Feb 2020 16:39:20 -0800 Date: Thu, 20 Feb 2020 16:39:21 -0800 From: "Darrick J. Wong" To: Dave Chinner Cc: Brian Foster , sandeen@sandeen.net, linux-xfs@vger.kernel.org Subject: Re: [PATCH 5/8] xfs_db: check that metadata updates have been committed Message-ID: <20200221003921.GE9506@magnolia> References: <158216290180.601264.5491208016048898068.stgit@magnolia> <158216293385.601264.3202158027072387776.stgit@magnolia> <20200220140623.GC48977@bfoster> <20200220165840.GX9506@magnolia> <20200220175857.GI48977@bfoster> <20200220183450.GA9506@magnolia> <20200221000119.GR10776@dread.disaster.area> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200221000119.GR10776@dread.disaster.area> User-Agent: Mutt/1.9.4 (2018-02-28) X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9537 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 bulkscore=0 malwarescore=0 mlxlogscore=999 suspectscore=2 adultscore=0 spamscore=0 mlxscore=0 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2001150001 definitions=main-2002210001 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9537 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 lowpriorityscore=0 malwarescore=0 suspectscore=2 bulkscore=0 spamscore=0 priorityscore=1501 phishscore=0 impostorscore=0 mlxlogscore=999 clxscore=1015 adultscore=0 mlxscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2001150001 definitions=main-2002210001 Sender: linux-xfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org On Fri, Feb 21, 2020 at 11:01:19AM +1100, Dave Chinner wrote: > On Thu, Feb 20, 2020 at 10:34:50AM -0800, Darrick J. Wong wrote: > > On Thu, Feb 20, 2020 at 12:58:57PM -0500, Brian Foster wrote: > > > On Thu, Feb 20, 2020 at 08:58:40AM -0800, Darrick J. Wong wrote: > > > > On Thu, Feb 20, 2020 at 09:06:23AM -0500, Brian Foster wrote: > > > > > On Wed, Feb 19, 2020 at 05:42:13PM -0800, Darrick J. Wong wrote: > > > > > > From: Darrick J. Wong > > > > > > > > > > > > Add a new function that will ensure that everything we scribbled on has > > > > > > landed on stable media, and report the results. > > > > > > > > > > > > Signed-off-by: Darrick J. Wong > > > > > > --- > > > > > > db/init.c | 14 ++++++++++++++ > > > > > > 1 file changed, 14 insertions(+) > > > > > > > > > > > > > > > > > > diff --git a/db/init.c b/db/init.c > > > > > > index 0ac37368..e92de232 100644 > > > > > > --- a/db/init.c > > > > > > +++ b/db/init.c > > > > > > @@ -184,6 +184,7 @@ main( > > > > > > char *input; > > > > > > char **v; > > > > > > int start_iocur_sp; > > > > > > + int d, l, r; > > > > > > > > > > > > init(argc, argv); > > > > > > start_iocur_sp = iocur_sp; > > > > > > @@ -216,6 +217,19 @@ main( > > > > > > */ > > > > > > while (iocur_sp > start_iocur_sp) > > > > > > pop_cur(); > > > > > > + > > > > > > + libxfs_flush_devices(mp, &d, &l, &r); > > > > > > + if (d) > > > > > > + fprintf(stderr, _("%s: cannot flush data device (%d).\n"), > > > > > > + progname, d); > > > > > > + if (l) > > > > > > + fprintf(stderr, _("%s: cannot flush log device (%d).\n"), > > > > > > + progname, l); > > > > > > + if (r) > > > > > > + fprintf(stderr, _("%s: cannot flush realtime device (%d).\n"), > > > > > > + progname, r); > > > > > > + > > > > > > + > > > > > > > > > > Seems like we could reduce some boilerplate by passing progname into > > > > > libxfs_flush_devices() and letting it dump out of the error messages, > > > > > unless there's some future code that cares about individual device error > > > > > state. > > > > > > > > Such a program could call libxfs_flush_devices directly, as we do here. > > > > > > > > > > Right.. but does anything actually care about that level of granularity > > > right now beyond having a nicer error message? > > > > No, afaict. > > > > > > Also, progname is defined in libxfs so we don't even need to pass it as > > > > an argument. > > > > > > > > > > Ok. > > > > > > > I had originally thought that we should try not to add fprintf calls to > > > > libxfs because libraries aren't really supposed to be doing things like > > > > that, but perhaps you're right that all of this should be melded into > > > > something else. > > > > > > > > > > Yeah, fair point, though I guess it depends on the particular library. > > > > I mean... is libxfs even a real library? :) > > It's an internal abstraction to allow code to be shared easily with > the kernel and between xfsprogs binaries. It is not a library in the > sense it has a fixed API and ABI that compatibility has to be > maintained across releases (i.e. like, say, libhandle). It is a > library in the sense is contains shared code that things within the > build don't have to re-implement them over and over again, and > because it is internal that means the rules for external/distro > level libraries don't need to be strictly applied. > > e.g. if -everything- uses a global variable and has to declares it > themselves so the shared internal code can access it, then why not > just declare it in the shared code? :) Fair enough. It's a sharedcode library. > > > > I dunno. My current thinking is that libxfs_umount should call > > > > libxfs_flush_devices() and print error messages as necessary, and return > > > > error codes as appropriate. xfs_repair can then check the umount return > > > > value and translate that into exit(1) as required. The device_close > > > > functions will fsync a second time, but that shouldn't be a big deal > > > > because we haven't dirtied anything in the meantime. > > > > > > > > Thoughts? > > > > > > > > > > I was thinking of having a per-device libxfs_device_flush() along the > > > lines of libxfs_device_close() and separating out that functionality, > > > but one could argue we're also a bit inconsistent between libxfs_init() > > > opening the devices and having to close them individually. > > > > Yeah, I don't understand why libxfs_destroy doesn't empty out the same > > struct libxfs_init that libxfs_init populates. Or why we have a global > > variable named "x", or why the buffer cache is a global variable. > > However, those sound like refactoring for another series. > > You mean structure the unmount code like we do in teh kernel? e.g: > > > > I think > > > having libxfs_umount() do a proper purge -> flush and returning any > > > errors instead is a fair tradeoff for simplicity. Removing the > > > flush_devices() API also eliminates risk of somebody incorrectly > > > attempting the flush after the umount frees the buftarg structures > > > (without reinitializing pointers :P). > > You mean like this code that I'm slowly working on to bring the > xfs_buf.c code across to userspace and get rid of the heap of crap > we have in libxfs/{rdwr,cache}.c now and be able to use AIO properly > and do non-synchronous delayed writes like we do in the kernel? > > libxfs/init.c: > .... > static void > buftarg_cleanup( > struct xfs_buftarg *btp) > { > if (!btp) > return; > > while (btp->bt_lru.l_count > 0) > xfs_buftarg_shrink(btp, 1000); > xfs_buftarg_wait(btp); > xfs_buftarg_free(btp); Not quite what the v3 series does, but only because it's still stuck with "whack the bcache and then go see what happened to each buftarg". > } > > /* > * Release any resource obtained during a mount. > */ > void > libxfs_umount( > struct xfs_mount *mp) > { > struct xfs_perag *pag; > int agno; > > libxfs_rtmount_destroy(mp); > > buftarg_cleanup(mp->m_ddev_targp); > buftarg_cleanup(mp->m_rtdev_targp); > if (mp->m_logdev_targp != mp->m_ddev_targp) > buftarg_cleanup(mp->m_logdev_targp); Yep, that's exactly where I moved the cleanup call in v3. > ..... > > libxfs/xfs_buftarg.c: > ..... > void > xfs_buftarg_free( > struct xfs_buftarg *btp) > { > ASSERT(percpu_counter_sum(&btp->bt_io_count) == 0); > percpu_counter_destroy(&btp->bt_io_count); > platform_flush_device(btp->bt_fd, btp->bt_bdev); > libxfs_device_close(btp->bt_bdev); > free(btp); I'm assuming this means you've killed off the buffer handling parts of struct libxfs_xinit too? > } > > I haven't added the error returns for this code yet - I'm still > doing the conversion and making it work. > > I'll probably have to throw the vast majority of that patchset away > and start again if all this API change that darrick has done is > merged. And that will probably involve me throwing away all of the > changes in this patch series because they just don't make any sense > once the code is restructured properly.... ...or just throw them at me in whatever state they're in now and let me help figure out how to get there? Everyone: don't be afraid of the 'RFCRAP' for interim patchsets. Granted, posting git branches with a timestamp might be more practicable... --D > > Cheers, > > Dave. > -- > Dave Chinner > david@fromorbit.com