kern/164516: [ext2fs] unable to mount EXT2 filesystem

[Uffe Jakobsen]

On 2012-01-28 23:31, Chris Rees wrote:
>
> On 28 Jan 2012 22:14, "Uffe Jakobsen" <uffe at uffe.org
> <mailto:uffe at uffe.org>> wrote:
>  >
>  >
>  >
>  > On 2012-01-28 01:47, Jeremy Chadwick wrote:
>  >>
>  >> On Fri, Jan 27, 2012 at 11:10:11PM +0000, Uffe Jakobsen wrote:
>  >>>
>  >>> The following reply was made to PR kern/164516; it has been noted
> by GNATS.
>  >>>
>  >>> From: Uffe Jakobsen<uffe at uffe.org <mailto:uffe at uffe.org>>
>  >>> To: bug-followup at FreeBSD.org
>  >>> Cc:
>  >>> Subject: Re: kern/164516: [ext2fs] unable to mount EXT2 filesystem
>  >>> Date: Fri, 27 Jan 2012 20:49:05 +0100
>  >>>
>  >>> >
>  >>> >  Not a bug. The file system type name is "ext2fs" not "ext2".
>  >>> >  Use "mount -t ext2fs /dev/md0 /mnt/tmp0" instead.
>  >>> >
>  >>>
>  >>>  Instead of reporting "Operation not supported by device"
>  >>>  Shouldn't it report unknown filesystem type ?
>  >>
>  >>
>  >> Please look through /usr/include/errno.h and let us know what error code
>  >> would represent "unknown filesystem type".  :-)
>  >>
>  >
>  > There are plenty of other places in the mount src where we exit
> without a specific error code. Question is if there exists a scenario
> where the requested filesystem type would/could not be found by
> getvfsbyname() ?
>  >
>  > I've met this problem myself a number of times - and even in this
> case I did not spot the spelling error right away ('ext2fs' and not 'ext2').
>  >
>  > The returned error 'Operation not supported by device' - atleast to
> me - indicates that the mount process got much further before running
> into some kind of problem. The times when I've met this error I've begun
> inspecting mount options etc before realizing that the fstype had a typo.
>  >
>
> Normally when an error comes up I check the manpage.

Manpage for mount does not at all mention any error conditions.

You'll have to know the inner workings of mount in order to know that in 
certain cases everything is thrown into nmount() and any error that 
comes up would come directly from nmount()

Anyway - would you accept a patch that checked the fstype using 
getvfsbyname() before calling nmount() ?

/Uffe