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Date:   Tue, 28 Jun 2022 18:57:23 +0100
From:   Al Viro <viro@zeniv.linux.org.uk>
To:     Ian Kent <raven@themaw.net>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Siddhesh Poyarekar <siddhesh@gotplt.org>,
        David Howells <dhowells@redhat.com>,
        Miklos Szeredi <miklos@szeredi.hu>,
        Carlos Maiolino <cmaiolino@redhat.com>,
        linux-fsdevel <linux-fsdevel@vger.kernel.org>,
        Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 2/2] vfs: escape hash as well
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References: <165637619182.37717.17755020386697900473.stgit@donald.themaw.net>
 <165637625806.37717.2027157232247047949.stgit@donald.themaw.net>
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On Tue, Jun 28, 2022 at 08:30:58AM +0800, Ian Kent wrote:
> From: Siddhesh Poyarekar <siddhesh@gotplt.org>
> 
> When a filesystem is mounted with a name that starts with a #:
> 
>  # mount '#name' /mnt/bad -t tmpfs
> 
> this will cause the entry to look like this (leading space added so
> that git does not strip it out):
> 
>  #name /mnt/bad tmpfs rw,seclabel,relatime,inode64 0 0
> 
> This breaks getmntent and any code that aims to parse fstab as well as
> /proc/mounts with the same logic since they need to strip leading spaces
> or skip over comment lines, due to which they report incorrect output or
> skip over the line respectively.
> 
> Solve this by translating the hash character into its octal encoding
> equivalent so that applications can decode the name correctly.
> 
> Signed-off-by: Siddhesh Poyarekar <siddhesh@gotplt.org>
> Signed-off-by: Ian Kent <raven@themaw.net>

ACK; I'll grab that one (in #work.misc - I don't believe it's #fixes
fodder).