linux-fsdevel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Mikael Magnusson <mikachu@gmail.com>
To: david@fromorbit.com
Cc: akpm@linux-foundation.org, amir73il@gmail.com,
	chris@chrisdown.name, hannes@cmpxchg.org, hughd@google.com,
	jlayton@kernel.org, kernel-team@fb.com,
	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-mm@kvack.org, tj@kernel.org, viro@zeniv.linux.org
Subject: Re: [PATCH v5 2/2] tmpfs: Support 64-bit inums per-sb
Date: Wed,  8 Jan 2020 15:37:52 +0100	[thread overview]
Message-ID: <20200108143752.9475-1-mikachu@gmail.com> (raw)
In-Reply-To: <20200107001039.GM23195@dread.disaster.area>

Dave Chinner writes:
> On Sun, Jan 05, 2020 at 12:06:05PM +0000, Chris Down wrote:
> > The default is still set to inode32 for backwards compatibility, but
> > system administrators can opt in to the new 64-bit inode numbers by
> > either:
> > 
> > 1. Passing inode64 on the command line when mounting, or
> > 2. Configuring the kernel with CONFIG_TMPFS_INODE64=y
> > 
> > The inode64 and inode32 names are used based on existing precedent from
> > XFS.
> 
> Please don't copy this misfeature of XFS.
> 
> The inode32/inode64 XFS options were a horrible hack made more than
> 20 years ago when NFSv2 was still in use and 64 bit inodes could
> not be used for NFSv2 exports. It was then continued to be used
> because 32bit NFSv3 clients were unable to handle 64 bit inodes.
> 
> It took 15 years for us to be able to essentially deprecate
> inode32 (inode64 is the default behaviour), and we were very happy
> to get that albatross off our necks.  In reality, almost everything
> out there in the world handles 64 bit inodes correctly
> including 32 bit machines and 32bit binaries on 64 bit machines.
> And, IMNSHO, there no excuse these days for 32 bit binaries that
> don't using the *64() syscall variants directly and hence support
> 64 bit inodes correctlyi out of the box on all platforms.
> 
> I don't think we should be repeating past mistakes by trying to
> cater for broken 32 bit applications on 64 bit machines in this day
> and age.

Hi,

It's unfortunately not true that everything handles this correctly.
32-bit binaries for games on Steam that use stat() without the 64 is
so prevalent that I got tired of adding the LD_PRELOAD wrapper script
and just patched out the EOVERFLOW return from glibc instead. (They
obviously don't care about the inode value at all, and I don't use any
other 32-bit binaries that do). This is probably a class of binaries
you don't care very much about, and not very likely to be installed on
a tmpfs that has wrapped around, but I thought it was worth mentioning
that they do exist anyway.

-- 
Mikael Magnusson

  parent reply	other threads:[~2020-01-08 14:38 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-05 12:05 [PATCH v5 0/2] fs: inode: shmem: Reduce risk of inum overflow Chris Down
2020-01-05 12:06 ` [PATCH v5 1/2] tmpfs: Add per-superblock i_ino support Chris Down
2020-01-06  2:03   ` zhengbin (A)
2020-01-06  6:41     ` Amir Goldstein
2020-01-07  8:01       ` Hugh Dickins
2020-01-07  8:35         ` Amir Goldstein
2020-01-08 10:58           ` Hugh Dickins
2020-01-08 12:51             ` Amir Goldstein
2020-01-06 13:17     ` Chris Down
2020-01-05 12:06 ` [PATCH v5 2/2] tmpfs: Support 64-bit inums per-sb Chris Down
2020-01-07  0:10   ` Dave Chinner
2020-01-07  0:16     ` Chris Down
2020-01-07  0:39       ` Dave Chinner
2020-01-07  6:54         ` Amir Goldstein
2020-01-07  8:36           ` Hugh Dickins
2020-01-07 10:12             ` Amir Goldstein
2020-01-07 21:07               ` Dave Chinner
2020-01-07 21:37                 ` Chris Mason
2020-01-08 11:24                   ` Hugh Dickins
2020-01-09  0:43                     ` Jeff Layton
2020-01-10 16:45                     ` Chris Down
2020-01-13  7:36                       ` Hugh Dickins
2020-01-20 15:11                         ` Chris Down
2020-02-25 23:14                           ` Hugh Dickins
2020-01-07 20:59             ` Dave Chinner
2020-01-08 14:37     ` Mikael Magnusson [this message]
2020-01-13  6:58       ` Hugh Dickins

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200108143752.9475-1-mikachu@gmail.com \
    --to=mikachu@gmail.com \
    --cc=akpm@linux-foundation.org \
    --cc=amir73il@gmail.com \
    --cc=chris@chrisdown.name \
    --cc=david@fromorbit.com \
    --cc=hannes@cmpxchg.org \
    --cc=hughd@google.com \
    --cc=jlayton@kernel.org \
    --cc=kernel-team@fb.com \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=tj@kernel.org \
    --cc=viro@zeniv.linux.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).