GNU bug report logs - #15257
stat and df report different filesystems for /dev

Previous Next

To add a comment to this bug, you must first unarchive it, by sending
a message to control AT debbugs.gnu.org, with unarchive 15257 in the body.
You can then email your comments to 15257 AT debbugs.gnu.org in the normal way.

Toggle the display of automated, internal messages from the tracker.

Message #5 received at submit <at> debbugs.gnu.org (full text, mbox):

From: C de-Avillez <hggdh2 <at> ubuntu.com>
To: bug-coreutils <at> gnu.org
Subject: stat and df report different filesystems for /dev
Date: Tue, 3 Sep 2013 08:50:43 -0500

[Message part 1 (text/plain, inline)]

original Ubuntu bug: https://bugs.launchpad.net/bugs/1219529

Tested on linux 3.11.RC7 and 3.8.8, coreutils 8.20 and 8.21

When trying to use 'df -x tmpfs', /dev is still shown:

hggdh <at> chatto:~$ df -x tmpfs | grep udev
udev              247532       8    247524   1% /dev

But 'stat' reports the filesystem as 'tmpfs':

hggdh <at> chatto:~$ stat -f /dev
  File: "/dev"
    ID: 0        Namelen: 255     Type: tmpfs
Block size: 4096       Fundamental block size: 4096
Blocks: Total: 61883      Free: 61881      Available: 61881
Inodes: Total: 61883      Free: 61479

This seems to happen because -- really -- the type is 'devtmpfs':

hggdh <at> chatto:~$ mount | grep udev
udev on /dev type devtmpfs (rw,mode=0755)

And, indeed, running 'df -x devtmpfs' works:

hggdh <at> chatto:~$ df -x devtmpfs
Filesystem     1K-blocks    Used Available Use% Mounted on
/dev/vda        20511356 2518320  16944460  13% /
none                   4       0         4   0% /sys/fs/cgroup
tmpfs              50300     232     50068   1% /run
none                5120       0      5120   0% /run/lock
none              251484      52    251432   1% /run/shm
none              102400       0    102400   0% /run/user

I feel this is incorrect: even though 'info mount' does not list devtmpfs
as a possible FS type (which might be another bug in itself, but outside
coreutils), at least 'stat' and 'df' should be consistent on their output.

Cheers,

-- 
..hggdh..

[Message part 2 (text/html, inline)]

Message #8 received at 15257 <at> debbugs.gnu.org (full text, mbox):

From: Pádraig Brady <P <at> draigBrady.com>
To: C de-Avillez <hggdh2 <at> ubuntu.com>
Cc: 15257 <at> debbugs.gnu.org
Subject: Re: bug#15257: stat and df report different filesystems for /dev
Date: Fri, 11 Jul 2014 10:31:30 +0100

On 09/03/2013 02:50 PM, C de-Avillez wrote:
> original Ubuntu bug: https://bugs.launchpad.net/bugs/1219529
> 
> Tested on linux 3.11.RC7 and 3.8.8, coreutils 8.20 and 8.21
> 
> When trying to use 'df -x tmpfs', /dev is still shown:
> 
> hggdh <at> chatto:~$ df -x tmpfs | grep udev
> udev              247532       8    247524   1% /dev
> 
> But 'stat' reports the filesystem as 'tmpfs':
> 
> hggdh <at> chatto:~$ stat -f /dev
>   File: "/dev"
>     ID: 0        Namelen: 255     Type: tmpfs
> Block size: 4096       Fundamental block size: 4096
> Blocks: Total: 61883      Free: 61881      Available: 61881
> Inodes: Total: 61883      Free: 61479
> 
> This seems to happen because -- really -- the type is 'devtmpfs':
> 
> hggdh <at> chatto:~$ mount | grep udev
> udev on /dev type devtmpfs (rw,mode=0755)
> 
> And, indeed, running 'df -x devtmpfs' works:
> 
> hggdh <at> chatto:~$ df -x devtmpfs
> Filesystem     1K-blocks    Used Available Use% Mounted on
> /dev/vda        20511356 2518320  16944460  13% /
> none                   4       0         4   0% /sys/fs/cgroup
> tmpfs              50300     232     50068   1% /run
> none                5120       0      5120   0% /run/lock
> none              251484      52    251432   1% /run/shm
> none              102400       0    102400   0% /run/user
> 
> I feel this is incorrect: even though 'info mount' does not list devtmpfs
> as a possible FS type (which might be another bug in itself, but outside
> coreutils), at least 'stat' and 'df' should be consistent on their output.

This is awkward but I'm not sure if there is anything coreutils can do.
The "mount level" type is "devtmpfs", while the underlying implementation
is "tmpfs" in your case, or it could be "ramfs" on some setups.
`stat` is just displaying the underlying file system type as indicated by the kernel.

thanks,
Pádraig.

Message #11 received at 15257 <at> debbugs.gnu.org (full text, mbox):

From: Assaf Gordon <assafgordon <at> gmail.com>
To: 15257 <at> debbugs.gnu.org
Subject: Re: bug#15257: stat and df report different filesystems for /dev
Date: Fri, 19 Oct 2018 16:46:06 -0600

severity 15257 wishlist
tags 15257 wontfix
close 15257
stop

(triaging old bugs)

Hello,

On 11/07/14 03:31 AM, Pádraig Brady wrote:
> On 09/03/2013 02:50 PM, C de-Avillez wrote:
>> original Ubuntu bug: https://bugs.launchpad.net/bugs/1219529
>>
>> When trying to use 'df -x tmpfs', /dev is still shown:
>>
[...]
> This is awkward but I'm not sure if there is anything coreutils can do.
> The "mount level" type is "devtmpfs", while the underlying implementation
> is "tmpfs" in your case, or it could be "ramfs" on some setups.

Given the above, and with no further follow-ups in 5 years,
I'm closing this as "wontfix".

Discussion can continue by replying to this thread.

-assaf

Previous Next

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