xfs: provide a centralized method for verifying inline fork data

Replace the current haphazard dir2 shortform verifier callsites with a
centralized verifier function that can be called either with the default
verifier functions or with a custom set.  This helps us strengthen
integrity checking while providing us with flexibility for repair tools.

xfs_repair wants this to be able to supply its own verifier functions
when trying to fix possibly corrupt metadata.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

fs/xfs/xfs_inode.h

@@ -491,4 +491,6 @@ extern struct kmem_zone	*xfs_inode_zone;
 /* The default CoW extent size hint. */
 #define XFS_DEFAULT_COWEXTSZ_HINT 32
 
+bool xfs_inode_verify_forks(struct xfs_inode *ip);
+
 #endif	/* __XFS_INODE_H__ */