[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>

fs/xfs/xfs_bmap_btree.c

@@ -2656,7 +2656,7 @@ xfs_bmbt_init_cursor(
 	cur->bc_blocklog = mp->m_sb.sb_blocklog;
 
 	cur->bc_ops = &xfs_bmbt_ops;
-	cur->bc_flags = XFS_BTREE_ROOT_IN_INODE;
+	cur->bc_flags = XFS_BTREE_LONG_PTRS | XFS_BTREE_ROOT_IN_INODE;
 
 	cur->bc_private.b.forksize = XFS_IFORK_SIZE(ip, whichfork);
 	cur->bc_private.b.ip = ip;

fs/xfs/xfs_btree.c

@@ -90,7 +90,7 @@ xfs_btree_check_block(
 	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 @@ xfs_btree_islastblock(
 
 	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 @@ xfs_btree_setbuf(
 	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)

fs/xfs/xfs_btree.h

@@ -115,11 +115,6 @@ union xfs_btree_rec {
 #define	XFS_BB_NUM_BITS		5
 #define	XFS_BB_ALL_BITS		((1 << XFS_BB_NUM_BITS) - 1)
 
-/*
- * Boolean to select which form of xfs_btree_block_t.bb_u to use.
- */
-#define	XFS_BTREE_LONG_PTRS(btnum)	((btnum) == XFS_BTNUM_BMAP)
-
 /*
  * Magic numbers for btree blocks.
  */
@@ -203,6 +198,7 @@ typedef struct xfs_btree_cur
 } xfs_btree_cur_t;
 
 /* cursor flags */
+#define XFS_BTREE_LONG_PTRS		(1<<0)	/* pointers are 64bits long */
 #define XFS_BTREE_ROOT_IN_INODE		(1<<1)	/* root may be variable size */