GNU bug report logs - #21372
df prioritizes some bind mounts over real ones.

Previous Next

Full log

Message #46 received at 21372-done <at> debbugs.gnu.org (full text, mbox):

From: Pádraig Brady <P <at> draigBrady.com>
To: Dave Chiluk <chiluk <at> canonical.com>, 21372-done <at> debbugs.gnu.org
Subject: Re: bug#21372: [PATCH v4] df: fix prioritize real mounts over bind
 mounts
Date: Mon, 21 Sep 2015 23:44:53 +0100

On 21/09/15 21:04, Dave Chiluk wrote:
> Fixes an issue where bind mounts with shorter mount directories than the
> original mount are prioritized when running df.  The root cause of this
> is that /proc/self/mountinfo now lists the filesystem device with bind
> mounts rather than the source directory. With /etc/mtab the source
> device was listed as the originating directory so this was not an issue.
> 
> More information is available here.
> https://bugs.launchpad.net/ubuntu/+source/coreutils/+bug/1432871
> ---
>  src/df.c | 9 +++++++--
>  1 file changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/src/df.c b/src/df.c
> index 2e541b9..4a3afa2 100644
> --- a/src/df.c
> +++ b/src/df.c
> @@ -652,9 +652,14 @@ filter_mount_list (bool devices_only)
>                else if ((strchr (me->me_devname, '/')
>                         /* let "real" devices with '/' in the name win.  */
>                          && ! strchr (devlist->me->me_devname, '/'))
> -                       /* let a shorter mountdir win.  */
> -                       || (strlen (devlist->me->me_mountdir)
> +                       /* let a shorter mountdir win. If it's mntroot is */
> +                       /* also shorter. i.e. not a bind mount. */
> +                       || ((strlen (devlist->me->me_mountdir)
>                             > strlen (me->me_mountdir))
> +                          && (devlist->me->me_mntroot == NULL
> +                             || me->me_mntroot == NULL
> +                             || (strlen (devlist->me->me_mntroot)
> +                                 >= strlen(me->me_mntroot))))
>                         /* let an entry overmounted on a new device win...  */
>                         || (! STREQ (devlist->me->me_devname, me->me_devname)
>                             /* ... but only when matching an existing mnt point,
> 

This logic looks correct thanks.
I'll adjust the comment a bit and maybe refactor
all the conditions to a single nearer_device_root boolean.

I'll push this later on,
with the associated gnulib update.

thanks,
Pádraig.

Previous Next

GNU bug tracking system
Copyright (C) 1999 Darren O. Benham, 1997,2003 nCipher Corporation Ltd, 1994-97 Ian Jackson.