[XFS] factor out xfs_read_agf helper

Add a helper to read the AGF header and perform basic verification.
Based on hunks from a larger patch from Dave Chinner.

(First sent on Juli 23rd)

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Niv Sardi <xaiki@sgi.com>
This commit is contained in:
From: Christoph Hellwig 2008-11-28 14:23:38 +11:00 • committed by Niv Sardi
commit 4805621a37
3 changed files with 61 additions and 36 deletions