[XFS] add a long pointers flag to xfs_btree_cur

Add a flag to the xfs btree cursor when using long (64bit) block pointers
instead of checking btnum == XFS_BTNUM_BMAP.

SGI-PV: 985583

SGI-Modid: xfs-linux-melb:xfs-kern:32181a

Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: Bill O'Donnell <billodo@sgi.com>
Signed-off-by: David Chinner <david@fromorbit.com>
diff --git a/fs/xfs/xfs_btree.c b/fs/xfs/xfs_btree.c
index 57e858f..59796b4 100644
--- a/fs/xfs/xfs_btree.c
+++ b/fs/xfs/xfs_btree.c
@@ -90,7 +90,7 @@
 	int			level,	/* level of the btree block */
 	xfs_buf_t		*bp)	/* buffer containing block, if any */
 {
-	if (XFS_BTREE_LONG_PTRS(cur->bc_btnum))
+	if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
 		xfs_btree_check_lblock(cur, (xfs_btree_lblock_t *)block, level,
 			bp);
 	else
@@ -516,7 +516,7 @@
 
 	block = xfs_btree_get_block(cur, level, &bp);
 	xfs_btree_check_block(cur, block, level, bp);
-	if (XFS_BTREE_LONG_PTRS(cur->bc_btnum))
+	if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
 		return be64_to_cpu(block->bb_u.l.bb_rightsib) == NULLDFSBNO;
 	else
 		return be32_to_cpu(block->bb_u.s.bb_rightsib) == NULLAGBLOCK;
@@ -808,7 +808,7 @@
 	if (!bp)
 		return;
 	b = XFS_BUF_TO_BLOCK(bp);
-	if (XFS_BTREE_LONG_PTRS(cur->bc_btnum)) {
+	if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
 		if (be64_to_cpu(b->bb_u.l.bb_leftsib) == NULLDFSBNO)
 			cur->bc_ra[lev] |= XFS_BTCUR_LEFTRA;
 		if (be64_to_cpu(b->bb_u.l.bb_rightsib) == NULLDFSBNO)