Message-ID: <3948ae7653d1cb7c51febcca26a35775e71a53b4.camel@kernel.org>
Date:   Thu, 06 Jul 2023 12:14:58 -0400
From:   Jeff Layton <jlayton@...nel.org>
To:     "Eric W. Biederman" <ebiederm@...ssion.com>
Cc:     jk@...abs.org, arnd@...db.de, mpe@...erman.id.au,
        npiggin@...il.com, christophe.leroy@...roup.eu, hca@...ux.ibm.com,
        gor@...ux.ibm.com, agordeev@...ux.ibm.com,
        borntraeger@...ux.ibm.com, svens@...ux.ibm.com,
        gregkh@...uxfoundation.org, arve@...roid.com, tkjos@...roid.com,
        maco@...roid.com, joel@...lfernandes.org, brauner@...nel.org,
        cmllamas@...gle.com, surenb@...gle.com,
        dennis.dalessandro@...nelisnetworks.com, jgg@...pe.ca,
        leon@...nel.org, bwarrum@...ux.ibm.com, rituagar@...ux.ibm.com,
        ericvh@...nel.org, lucho@...kov.net, asmadeus@...ewreck.org,
        linux_oss@...debyte.com, dsterba@...e.com, dhowells@...hat.com,
        marc.dionne@...istor.com, viro@...iv.linux.org.uk,
        raven@...maw.net, luisbg@...nel.org, salah.triki@...il.com,
        aivazian.tigran@...il.com, keescook@...omium.org, clm@...com,
        josef@...icpanda.com, xiubli@...hat.com, idryomov@...il.com,
        jaharkes@...cmu.edu, coda@...cmu.edu, jlbec@...lplan.org,
        hch@....de, nico@...xnic.net, rafael@...nel.org, code@...icks.com,
        ardb@...nel.org, xiang@...nel.org, chao@...nel.org,
        huyue2@...lpad.com, jefflexu@...ux.alibaba.com,
        linkinjeon@...nel.org, sj1557.seo@...sung.com, jack@...e.com,
        tytso@....edu, adilger.kernel@...ger.ca, jaegeuk@...nel.org,
        hirofumi@...l.parknet.co.jp, miklos@...redi.hu,
        rpeterso@...hat.com, agruenba@...hat.com, richard@....at,
        anton.ivanov@...bridgegreys.com, johannes@...solutions.net,
        mikulas@...ax.karlin.mff.cuni.cz, mike.kravetz@...cle.com,
        muchun.song@...ux.dev, dwmw2@...radead.org, shaggy@...nel.org,
        tj@...nel.org, trond.myklebust@...merspace.com, anna@...nel.org,
        chuck.lever@...cle.com, neilb@...e.de, kolga@...app.com,
        Dai.Ngo@...cle.com, tom@...pey.com, konishi.ryusuke@...il.com,
        anton@...era.com, almaz.alexandrovich@...agon-software.com,
        mark@...heh.com, joseph.qi@...ux.alibaba.com, me@...copeland.com,
        hubcap@...ibond.com, martin@...ibond.com, amir73il@...il.com,
        mcgrof@...nel.org, yzaikin@...gle.com, tony.luck@...el.com,
        gpiccoli@...lia.com, al@...rsen.net, sfrench@...ba.org,
        pc@...guebit.com, lsahlber@...hat.com, sprasad@...rosoft.com,
        senozhatsky@...omium.org, phillip@...ashfs.org.uk,
        rostedt@...dmis.org, mhiramat@...nel.org, dushistov@...l.ru,
        hdegoede@...hat.com, djwong@...nel.org, dlemoal@...nel.org,
        naohiro.aota@....com, jth@...nel.org, ast@...nel.org,
        daniel@...earbox.net, andrii@...nel.org, martin.lau@...ux.dev,
        song@...nel.org, yhs@...com, john.fastabend@...il.com,
        kpsingh@...nel.org, sdf@...gle.com, haoluo@...gle.com,
        jolsa@...nel.org, hughd@...gle.com, akpm@...ux-foundation.org,
        davem@...emloft.net, edumazet@...gle.com, kuba@...nel.org,
        pabeni@...hat.com, john.johansen@...onical.com,
        paul@...l-moore.com, jmorris@...ei.org, serge@...lyn.com,
        stephen.smalley.work@...il.com, eparis@...isplace.org,
        jgross@...e.com, stern@...land.harvard.edu, lrh2000@....edu.cn,
        sebastian.reichel@...labora.com, wsa+renesas@...g-engineering.com,
        quic_ugoswami@...cinc.com, quic_linyyuan@...cinc.com,
        john@...ping.me.uk, error27@...il.com, quic_uaggarwa@...cinc.com,
        hayama@...eo.co.jp, jomajm@...il.com, axboe@...nel.dk,
        dhavale@...gle.com, dchinner@...hat.com, hannes@...xchg.org,
        zhangpeng362@...wei.com, slava@...eyko.com, gargaditya08@...e.com,
        penguin-kernel@...ove.SAKURA.ne.jp, yifeliu@...stonybrook.edu,
        madkar@...stonybrook.edu, ezk@...stonybrook.edu,
        yuzhe@...china.com, willy@...radead.org, okanatov@...il.com,
        jeffxu@...omium.org, linux@...blig.org, mirimmad17@...il.com,
        yijiangshan@...inos.cn, yang.yang29@....com.cn,
        xu.xin16@....com.cn, chengzhihao1@...wei.com, shr@...kernel.io,
        Liam.Howlett@...cle.com, adobriyan@...il.com,
        chi.minghao@....com.cn, roberto.sassu@...wei.com,
        linuszeng@...cent.com, bvanassche@....org, zohar@...ux.ibm.com,
        yi.zhang@...wei.com, trix@...hat.com, fmdefrancesco@...il.com,
        ebiggers@...gle.com, princekumarmaurya06@...il.com,
        chenzhongjin@...wei.com, riel@...riel.com,
        shaozhengchao@...wei.com, jingyuwang_vip@....com,
        linuxppc-dev@...ts.ozlabs.org, linux-kernel@...r.kernel.org,
        linux-s390@...r.kernel.org, linux-rdma@...r.kernel.org,
        linux-usb@...r.kernel.org, v9fs@...ts.linux.dev,
        linux-fsdevel@...r.kernel.org, linux-afs@...ts.infradead.org,
        autofs@...r.kernel.org, linux-mm@...ck.org,
        linux-btrfs@...r.kernel.org, ceph-devel@...r.kernel.org,
        codalist@...a.cs.cmu.edu, ecryptfs@...r.kernel.org,
        linux-efi@...r.kernel.org, linux-erofs@...ts.ozlabs.org,
        linux-ext4@...r.kernel.org, linux-f2fs-devel@...ts.sourceforge.net,
        cluster-devel@...hat.com, linux-um@...ts.infradead.org,
        linux-mtd@...ts.infradead.org,
        jfs-discussion@...ts.sourceforge.net, linux-nfs@...r.kernel.org,
        linux-nilfs@...r.kernel.org, linux-ntfs-dev@...ts.sourceforge.net,
        ntfs3@...ts.linux.dev, ocfs2-devel@...ts.linux.dev,
        linux-karma-devel@...ts.sourceforge.net, devel@...ts.orangefs.org,
        linux-unionfs@...r.kernel.org, linux-hardening@...r.kernel.org,
        reiserfs-devel@...r.kernel.org, linux-cifs@...r.kernel.org,
        samba-technical@...ts.samba.org,
        linux-trace-kernel@...r.kernel.org, linux-xfs@...r.kernel.org,
        bpf@...r.kernel.org, netdev@...r.kernel.org,
        apparmor@...ts.ubuntu.com, linux-security-module@...r.kernel.org,
        selinux@...r.kernel.org
Subject: Re: [PATCH v2 00/89] fs: new accessors for inode->i_ctime

On Thu, 2023-07-06 at 10:16 -0500, Eric W. Biederman wrote:
> Jeff Layton <jlayton@...nel.org> writes:
> 
> > On Wed, 2023-07-05 at 14:58 -0400, Jeff Layton wrote:
> > > v2:
> > > - prepend patches to add missing ctime updates
> > > - add simple_rename_timestamp helper function
> > > - rename ctime accessor functions as inode_get_ctime/inode_set_ctime_*
> > > - drop individual inode_ctime_set_{sec,nsec} helpers
> > > 
> > > I've been working on a patchset to change how the inode->i_ctime is
> > > accessed in order to give us conditional, high-res timestamps for the
> > > ctime and mtime. struct timespec64 has unused bits in it that we can use
> > > to implement this. In order to do that however, we need to wrap all
> > > accesses of inode->i_ctime to ensure that bits used as flags are
> > > appropriately handled.
> > > 
> > > The patchset starts with reposts of some missing ctime updates that I
> > > spotted in the tree. It then adds a new helper function for updating the
> > > timestamp after a successful rename, and new ctime accessor
> > > infrastructure.
> > > 
> > > The bulk of the patchset is individual conversions of different
> > > subsysteme to use the new infrastructure. Finally, the patchset renames
> > > the i_ctime field to __i_ctime to help ensure that I didn't miss
> > > anything.
> > > 
> > > This should apply cleanly to linux-next as of this morning.
> > > 
> > > Most of this conversion was done via 5 different coccinelle scripts, run
> > > in succession, with a large swath of by-hand conversions to clean up the
> > > remainder.
> > > 
> > 
> > A couple of other things I should note:
> > 
> > If you sent me an Acked-by or Reviewed-by in the previous set, then I
> > tried to keep it on the patch here, since the respun patches are mostly
> > just renaming stuff from v1. Let me know if I've missed any.
> > 
> > I've also pushed the pile to my tree as this tag:
> > 
> >     https://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux.git/tag/?h=ctime.20230705
> > 
> > In case that's easier to work with.
> 
> Are there any preliminary patches showing what you want your introduced
> accessors to turn into?  It is hard to judge the sanity of the
> introduction of wrappers without seeing what the wrappers are ultimately
> going to do.
> 
> Eric

I have a draft version of the multigrain patches on top of the wrapper
conversion I've already posted in my "mgctime-experimental" branch:

    https://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux.git/log/?h=mgctime-experimental

The rationale is best explained in this changelog:

    https://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux.git/commit/?h=mgctime-experimental&id=face437a144d3375afb7f70c233b0644b4edccba

The idea will be to enable this on a per-fs basis.
-- 
Jeff Layton <jlayton@...nel.org>

Powered by blists - more mailing lists