path: root/fs/reiserfs/ibalance.c

/*
 * Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
 */

#include <asm/uaccess.h>
#include <linux/string.h>
#include <linux/time.h>
#include <linux/reiserfs_fs.h>
#include <linux/buffer_head.h>

/* this is one and only function that is used outside (do_balance.c) */
int balance_internal(struct tree_balance *,
		     int, int, struct item_head *, struct buffer_head **);

/* modes of internal_shift_left, internal_shift_right and internal_insert_childs */
#define INTERNAL_SHIFT_FROM_S_TO_L 0
#define INTERNAL_SHIFT_FROM_R_TO_S 1
#define INTERNAL_SHIFT_FROM_L_TO_S 2
#define INTERNAL_SHIFT_FROM_S_TO_R 3
#define INTERNAL_INSERT_TO_S 4
#define INTERNAL_INSERT_TO_L 5
#define INTERNAL_INSERT_TO_R 6

static void internal_define_dest_src_infos(int shift_mode,
					   struct tree_balance *tb,
					   int h,
					   struct buffer_info *dest_bi,
					   struct buffer_info *src_bi,
					   int *d_key, struct buffer_head **cf)
{
	memset(dest_bi, 0, sizeof(struct buffer_info));
	memset(src_bi, 0, sizeof(struct buffer_info));
	/* define dest, src, dest parent, dest position */
	switch (shift_mode) {
	case INTERNAL_SHIFT_FROM_S_TO_L:	/* used in internal_shift_left */
		src_bi->tb = tb;
		src_bi->bi_bh = PATH_H_PBUFFER(tb->tb_path, h);
		src_bi->bi_parent = PATH_H_PPARENT(tb->tb_path, h);
		src_bi->bi_position = PATH_H_POSITION(tb->tb_path, h + 1);
		dest_bi->tb = tb;
		dest_bi->bi_bh = tb->L[h];
		dest_bi->bi_parent = tb->FL[h];
		dest_bi->bi_position = get_left_neighbor_position(tb, h);
		*d_key = tb->lkey[h];
		*cf = tb->CFL[h];
		break;
	case INTERNAL_SHIFT_FROM_L_TO_S:
		src_bi->tb = tb;
		src_bi->bi_bh = tb->L[h];
		src_bi->bi_parent = tb->FL[h];
		src_bi->bi_position = get_left_neighbor_position(tb, h);
		dest_bi->tb = tb;
		dest_bi->bi_bh = PATH_H_PBUFFER(tb->tb_path, h);
		dest_bi->bi_parent = PATH_H_PPARENT(tb->tb_path, h);
		dest_bi->bi_position = PATH_H_POSITION(tb->tb_path, h + 1);	/* dest position is analog of dest->b_item_order */
		*d_key = tb->lkey[h];
		*cf = tb->CFL[h];
		break;

	case INTERNAL_SHIFT_FROM_R_TO_S:	/* used in internal_shift_left */
		src_bi->tb = tb;
		src_bi->bi_bh = tb->R[h];
		src_bi->bi_parent = tb->FR[h];
		src_bi->bi_position = get_right_neighbor_position(tb, h);
		dest_bi->tb = tb;
		dest_bi->bi_bh = PATH_H_PBUFFER(tb->tb_path, h);
		dest_bi->bi_parent = PATH_H_PPARENT(tb->tb_path, h);
		dest_bi->bi_position = PATH_H_POSITION(tb->tb_path, h + 1);
		*d_key = tb->rkey[h];
		*cf = tb->CFR[h];
		break;

	case INTERNAL_SHIFT_FROM_S_TO_R:
		src_bi->tb = tb;
		src_bi->bi_bh = PATH_H_PBUFFER(tb->tb_path, h);
		src_bi->bi_parent = PATH_H_PPARENT(tb->tb_path, h);
		src_bi->bi_position = PATH_H_POSITION(tb->tb_path, h + 1);
		dest_bi->tb = tb;
		dest_bi->bi_bh = tb->R[h];
		dest_bi->bi_parent = tb->FR[h];
		dest_bi->bi_position = get_right_neighbor_position(tb, h);
		*d_key = tb->rkey[h];
		*cf = tb->CFR[h];
		break;

	case INTERNAL_INSERT_TO_L</