[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>
diff --git a/fs/xfs/xfs_ag.h b/fs/xfs/xfs_ag.h
index f4a3153..f2e2181 100644
--- a/fs/xfs/xfs_ag.h
+++ b/fs/xfs/xfs_ag.h
@@ -91,6 +91,8 @@
#define XFS_AGF_BLOCK(mp) XFS_HDR_BLOCK(mp, XFS_AGF_DADDR(mp))
#define XFS_BUF_TO_AGF(bp) ((xfs_agf_t *)XFS_BUF_PTR(bp))
+extern int xfs_read_agf(struct xfs_mount *mp, struct xfs_trans *tp,
+ xfs_agnumber_t agno, int flags, struct xfs_buf **bpp);
/*
* Size of the unlinked inode hash table in the agi.