[XFS] Cleanup maxrecs calculation.

Clean up the way the maximum and minimum records for the btree blocks are
calculated. For the alloc and inobt btrees all the values are
pre-calculated in xfs_mount_common, and we switch the current loop around
the ugly generic macros that use cpp token pasting to generate type names
to two small helpers in normal C code. For the bmbt and bmdr trees these
helpers also exist, but can be called during runtime, too. Here we also
kill various macros dealing with them and inline the logic into the
get_minrecs / get_maxrecs / get_dmaxrecs methods in xfs_bmap_btree.c.

Note that all these new helpers take an xfs_mount * argument which will be
needed to determine the size of a btree block once we add support for
extended btree blocks with CRCs and other RAS information.

SGI-PV: 988146

SGI-Modid: xfs-linux-melb:xfs-kern:32292a

Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Donald Douwsma <donaldd@sgi.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
diff --git a/fs/xfs/xfs_alloc_btree.h b/fs/xfs/xfs_alloc_btree.h
index 22f1d70..ff1f71d 100644
--- a/fs/xfs/xfs_alloc_btree.h
+++ b/fs/xfs/xfs_alloc_btree.h
@@ -56,12 +56,6 @@
 #define	XFS_BUF_TO_ALLOC_BLOCK(bp)	((xfs_alloc_block_t *)XFS_BUF_PTR(bp))
 
 /*
- * Real block structures have a size equal to the disk block size.
- */
-#define	XFS_ALLOC_BLOCK_MAXRECS(lev,cur) ((cur)->bc_mp->m_alloc_mxr[lev != 0])
-#define	XFS_ALLOC_BLOCK_MINRECS(lev,cur) ((cur)->bc_mp->m_alloc_mnr[lev != 0])
-
-/*
  * Minimum and maximum blocksize and sectorsize.
  * The blocksize upper limit is pretty much arbitrary.
  * The sectorsize upper limit is due to sizeof(sb_sectsize).
@@ -98,5 +92,6 @@
 extern struct xfs_btree_cur *xfs_allocbt_init_cursor(struct xfs_mount *,
 		struct xfs_trans *, struct xfs_buf *,
 		xfs_agnumber_t, xfs_btnum_t);
+extern int xfs_allocbt_maxrecs(struct xfs_mount *, int, int);
 
 #endif	/* __XFS_ALLOC_BTREE_H__ */