[PATCH] xfs_metadump: Make -F (force) optional

[Christoph Hellwig]

Looks good,

Reviewed-by: Christoph Hellwig <hch at lst.de>

> xfs_metadump will pass "-F" to xfs_db to carry on even in the face
> of bad superblock magic. [1]  Depending on what we gave as an input
> file, we may very well fail quite badly:
> 
> > xfs_metadump: /root/anaconda.cfg is not a valid XFS filesystem (unexpected SB magic number 0x230a2320)
> > Floating point exception
> 
> I don't think it's possible to harden every path through libxfs for
> non-xfs filesystems as input.  (Even if it's possible, I don't think it's
> worth the effort).

Can you add a test to verify that xfs_metadump now correctly rejects
files that don't have a valid superblock?