All of lore.kernel.org
 help / color / mirror / Atom feed
From: Aleksa Sarai <cyphar@cyphar.com>
To: Al Viro <viro@zeniv.linux.org.uk>
Cc: Florian Weimer <fw@deneb.enyo.de>,
	"Darrick J. Wong" <darrick.wong@oracle.com>,
	Christoph Hellwig <hch@infradead.org>,
	linux-xfs@vger.kernel.org, libc-alpha@sourceware.org,
	linux-fsdevel@vger.kernel.org, Rich Felker <dalias@libc.org>
Subject: Re: XFS reports lchmod failure, but changes file system contents
Date: Fri, 21 Feb 2020 16:21:42 +1100	[thread overview]
Message-ID: <20200221052142.qfvpuga7r6u6p474@yavin.dot.cyphar.com> (raw)
In-Reply-To: <20200221050205.GW23230@ZenIV.linux.org.uk>

[-- Attachment #1: Type: text/plain, Size: 1493 bytes --]

On 2020-02-21, Al Viro <viro@zeniv.linux.org.uk> wrote:
> On Fri, Feb 21, 2020 at 03:09:19PM +1100, Aleksa Sarai wrote:
> >  * open(/proc/self/fd/$n) failing with ELOOP might actually be a bug
> >    (the error is coming from may_open as though the lookup was done with
> >    O_NOFOLLOW) -- the nd_jump_link() jump takes the namei lookup to a
> >    the symlink but it looks like the normal link_path_walk et al
> >    handling doesn't actually try to continue resolving it. I'll look
> >    into this a bit more.
> 
> Not a bug.  Neither mount nor symlink traversal applies to destinations
> of pure jumps (be it a symlink to "/" or a procfs symlink).  Both are
> deliberate and both for very good reasons.  We'd discussed that last
> year (and I'm going to cover that on LSF); basically, there's no
> good semantics for symlink traversal in such situation.

Fair enough, I figured there might be a deeper reason I was missing. ;)

> Again, this is absolutely deliberate.  And for sanity sake, don't bother
> with link_path_walk() et.al. state in mainline - see #work.namei or
> #work.do_last in vfs.git; I'm going to repost that series tonight or
> tomorrow.  The logics is easier to follow there.

Yeah, will do. I took a quick look when you posted it originally and I
agree it does seem more reasonable, I'll read through it in more depth
once you resend it.

-- 
Aleksa Sarai
Senior Software Engineer (Containers)
SUSE Linux GmbH
<https://www.cyphar.com/>

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 228 bytes --]

  reply	other threads:[~2020-02-21  5:21 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-12 11:48 XFS reports lchmod failure, but changes file system contents Florian Weimer
2020-02-12 12:15 ` Florian Weimer
2020-02-12 16:16 ` Darrick J. Wong
2020-02-12 18:11   ` Christoph Hellwig
2020-02-12 18:37     ` Darrick J. Wong
2020-02-12 19:15       ` Florian Weimer
2020-02-12 19:51         ` Al Viro
2020-02-12 19:55           ` Rich Felker
2020-02-12 20:01           ` Florian Weimer
2020-02-12 20:17             ` Andreas Schwab
2020-02-12 20:19               ` Rich Felker
2020-02-12 20:26                 ` Florian Weimer
2020-02-12 20:38                   ` Rich Felker
2020-02-12 20:27                 ` Al Viro
2020-02-12 20:36                   ` Rich Felker
2020-02-12 20:18             ` Rich Felker
2020-02-12 20:38             ` Paul Eggert
2020-02-21  4:09             ` Aleksa Sarai
2020-02-21  5:02               ` Al Viro
2020-02-21  5:21                 ` Aleksa Sarai [this message]
2020-02-12 18:50     ` Florian Weimer
2020-02-12 18:55       ` Christoph Hellwig

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=20200221052142.qfvpuga7r6u6p474@yavin.dot.cyphar.com \
    --to=cyphar@cyphar.com \
    --cc=dalias@libc.org \
    --cc=darrick.wong@oracle.com \
    --cc=fw@deneb.enyo.de \
    --cc=hch@infradead.org \
    --cc=libc-alpha@sourceware.org \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-xfs@vger.kernel.org \
    --cc=viro@zeniv.linux.org.uk \
    /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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.