mount error message

mount error message

[Bruce Dubbs]

I have a user that complains that mount is giving an incorrect error 
message under some circumstances.  For instance if mtab is symlinked to 
/proc/self/mounts the command and /run is not in fstab:

$ mount /run

returns an error message:

   mount: /run: No such file or directory

However if mtab is a regular file, the error message is:

   mount: can't find /run in /etc/fstab

It would be appropriate if both situations could return the 2nd message.

   -- Bruce Dubbs
      linuxfromscratch.org

Re: mount error message

[Helmut Hullen]

Hallo, Bruce,

Du meintest am 07.09.14:

> I have a user that complains that mount is giving an incorrect error
> message under some circumstances.  For instance if mtab is symlinked
> to /proc/self/mounts the command and /run is not in fstab:

> $ mount /run

> returns an error message:

>    mount: /run: No such file or directory

> However if mtab is a regular file, the error message is:

>    mount: can't find /run in /etc/fstab

> It would be appropriate if both situations could return the 2nd
> message.

There's no need to put the device into a special line in "/etc/fstab".

        mount /dev/sdxn /run

should always work, with the appropriate values for x and n.

Viele Gruesse!
Helmut

Re: mount error message

[Dale R. Worley]

> From: Bruce Dubbs <bruce.dubbs@gmail.com>

> $ mount /run
> 
> returns an error message:
> 
>    mount: /run: No such file or directory

Does the directory /run exist on the system?

If it exists, then this message should not be appearing.

If it does exist, and also /run isn't in /etc/fstab, then mount has
the choice of which error to report.

Dale

Re: mount error message

[Bruce Dubbs]

Helmut Hullen wrote:
> Hallo, Bruce,
>
> Du meintest am 07.09.14:
>
>> I have a user that complains that mount is giving an incorrect error
>> message under some circumstances.  For instance if mtab is symlinked
>> to /proc/self/mounts the command and /run is not in fstab:
>
>> $ mount /run
>
>> returns an error message:
>
>>     mount: /run: No such file or directory
>
>> However if mtab is a regular file, the error message is:
>
>>     mount: can't find /run in /etc/fstab
>
>> It would be appropriate if both situations could return the 2nd
>> message.
>
> There's no need to put the device into a special line in "/etc/fstab".
>
>          mount /dev/sdxn /run
>
> should always work, with the appropriate values for x and n.

Unless your script does not know what x or n are in advance.

Actually I followed up my original post and said the it was invalid.

   -- Bruce

Re: mount error message

[Karel Zak]

On Sun, Sep 07, 2014 at 01:19:05PM -0500, Bruce Dubbs wrote:
> I have a user that complains that mount is giving an incorrect error message
> under some circumstances.  For instance if mtab is symlinked to
> /proc/self/mounts the command and /run is not in fstab:
> 
> $ mount /run
> 
> returns an error message:
> 
>   mount: /run: No such file or directory
> 
> However if mtab is a regular file, the error message is:
> 
>   mount: can't find /run in /etc/fstab


$ test -d /mnt/test && echo "yes" || echo "no"
yes
$ test -d /nothing && echo "yes" || echo "no"
no


$ ls -l  /etc/mtab 
lrwxrwxrwx 1 root root 12 Jun 17 15:42 /etc/mtab -> /proc/mounts

$ mount /mnt/test
mount: can't find /mnt/test in /etc/fstab

$ mount /nothing
mount: /nothing: No such file or directory


$ ls -l  /etc/mtab 
-r--r--r-- 1 root root 2693 Sep 10 10:16 /etc/mtab

$ mount /mnt/test
mount: can't find /mnt/test in /etc/fstab
$ mount /nothing 
mount: /nothing: No such file or directory


All works as expected.

Note that mount(8) sanitize paths specified by non-root users on
command line, so the message "No such file or directory" is really
expected and it's far before libmount starts to evaluate things in
mtab/fstab.

    Karel

-- 
 Karel Zak  <kzak@redhat.com>
 http://karelzak.blogspot.com

Re: mount error message

[Dylan Cali]

Karel Zak <kzak@...> writes:

> 
> On Sun, Sep 07, 2014 at 01:19:05PM -0500, Bruce Dubbs wrote:
> > I have a user that complains that mount is giving an incorrect error message
> > under some circumstances.  For instance if mtab is symlinked to
> > /proc/self/mounts the command and /run is not in fstab:
> > 
> > $ mount /run
> > 
> > returns an error message:
> > 
> >   mount: /run: No such file or directory
> > 
> > However if mtab is a regular file, the error message is:
> > 
> >   mount: can't find /run in /etc/fstab
> 
> $ test -d /mnt/test && echo "yes" || echo "no"
> yes
> $ test -d /nothing && echo "yes" || echo "no"
> no
> 
> $ ls -l  /etc/mtab 
> lrwxrwxrwx 1 root root 12 Jun 17 15:42 /etc/mtab -> /proc/mounts
> 
> $ mount /mnt/test
> mount: can't find /mnt/test in /etc/fstab
> 
> $ mount /nothing
> mount: /nothing: No such file or directory
> 
> $ ls -l  /etc/mtab 
> -r--r--r-- 1 root root 2693 Sep 10 10:16 /etc/mtab
> 
> $ mount /mnt/test
> mount: can't find /mnt/test in /etc/fstab
> $ mount /nothing 
> mount: /nothing: No such file or directory
> 
> All works as expected.
> 
> Note that mount(8) sanitize paths specified by non-root users on
> command line, so the message "No such file or directory" is really
> expected and it's far before libmount starts to evaluate things in
> mtab/fstab.
> 
>     Karel
> 

Hello I'm the user in question.  The specific situation was a boot time
failure where /proc had failed to mount.  So to enumerate the conditions and
the result:

1) /proc is not mounted (or has failed to mount)
2) /etc/mtab is a symlink to /proc/mounts (or /proc/self/mounts)
3) /run is not in /etc/fstab
4) The directory /run exists on the filesystem

In this situation 'mount /run' results in: 
mount: /run: mount failed: No such file or directory

Obviously mount is referring to /etc/mtab not existing, so the error message
at present is misleading.

Re: mount error message

[Karel Zak]

On Thu, Sep 11, 2014 at 01:52:44AM +0000, Dylan Cali wrote:
> Hello I'm the user in question.  The specific situation was a boot time
> failure where /proc had failed to mount.  So to enumerate the conditions and
> the result:
> 
> 1) /proc is not mounted (or has failed to mount)
> 2) /etc/mtab is a symlink to /proc/mounts (or /proc/self/mounts)
> 3) /run is not in /etc/fstab
> 4) The directory /run exists on the filesystem

Very special use-case :-)

> In this situation 'mount /run' results in: 
> mount: /run: mount failed: No such file or directory
> 
> Obviously mount is referring to /etc/mtab not existing, so the error message
> at present is misleading.

Fixed in master branch. Thanks!

    Karel

-- 
 Karel Zak  <kzak@redhat.com>
 http://karelzak.blogspot.com

Re: mount error message

[Dylan Cali]

On Tue, Sep 16, 2014 at 8:36 AM, Karel Zak <kzak@redhat.com> wrote:
> On Thu, Sep 11, 2014 at 01:52:44AM +0000, Dylan Cali wrote:
>> 1) /proc is not mounted (or has failed to mount)
>> 2) /etc/mtab is a symlink to /proc/mounts (or /proc/self/mounts)
>> 3) /run is not in /etc/fstab
>> 4) The directory /run exists on the filesystem
>
> Very special use-case :-)
>
>> In this situation 'mount /run' results in:
>> mount: /run: mount failed: No such file or directory
>
> Fixed in master branch. Thanks!

Always trust random internet user to find the corner case :)  Thanks
for your help!


Dylan