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reiserfsprogs/reiserfscore/ibalance.c
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/*
* Copyright 1996-2003 by Hans Reiser, licensing governed by
* reiserfsprogs/README
*/
#include "includes.h"
/* this is one and only function that is used outside (do_balance.c) */
int balance_internal (
/*struct reiserfs_transaction_handle *th,*/
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
)
{
/* define dest, src, dest parent, dest position */
switch (shift_mode) {
case INTERNAL_SHIFT_FROM_S_TO_L: /* used in internal_shift_left */
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->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->bi_bh = tb->L[h];
src_bi->bi_parent = tb->FL[h];
src_bi->bi_position = get_left_neighbor_position (tb, h);
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->bi_bh = tb->R[h];
src_bi->bi_parent = tb->FR[h];
src_bi->bi_position = get_right_neighbor_position (tb, h);
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->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->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:
dest_bi->bi_bh = tb->L[h];
dest_bi->bi_parent = tb->FL[h];
dest_bi->bi_position = get_left_neighbor_position (tb, h);
break;
case INTERNAL_INSERT_TO_S:
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);
break;
case INTERNAL_INSERT_TO_R:
dest_bi->bi_bh = tb->R[h];
dest_bi->bi_parent = tb->FR[h];
dest_bi->bi_position = get_right_neighbor_position (tb, h);
break;
default:
reiserfs_panic ("internal_define_dest_src_infos", "shift type is unknown (%d)", shift_mode);
}
}
/* Insert 'count' node pointers into buffer cur before position 'to' + 1.
* Insert count items into buffer cur before position to.
* Items and node pointers are specified by inserted and bh respectively.
*/
static void internal_insert_childs (reiserfs_filsys_t * fs,
struct buffer_info * cur_bi,
int to, int count,
struct item_head * inserted,
struct buffer_head ** bh)
{
struct buffer_head * cur = cur_bi->bi_bh;
struct block_head * blkh;
int nr;
struct key * key;
struct disk_child new_dc[2];
struct disk_child * dc;
int i;
int from;
if (count <= 0)
return;
blkh = B_BLK_HEAD (cur);
nr = get_blkh_nr_items (blkh);
/* prepare space for count disk_child */
dc = B_N_CHILD (cur,to+1);
memmove (dc + count, dc, (nr+1-(to+1)) * DC_SIZE);
/* make disk child array for insertion */
for (i = 0; i < count; i ++) {
set_dc_child_size (new_dc + i,
MAX_CHILD_SIZE(bh[i]->b_size) -
get_blkh_free_space (B_BLK_HEAD (bh[i])));
set_dc_child_blocknr (new_dc + i, bh[i]->b_blocknr);
}
memcpy (dc, new_dc, DC_SIZE * count);
/* prepare space for 'count' items */
from = ((to == -1) ? 0 : to);
key = B_N_PDELIM_KEY (cur, from);
memmove (key + count, key, (nr - from/*to*/) * KEY_SIZE + (nr + 1 + count) * DC_SIZE);
/* copy keys */
memcpy (key, inserted, KEY_SIZE);
if ( count > 1 )
memcpy (key + 1, inserted + 1, KEY_SIZE);
/* sizes, item number */
set_blkh_nr_items (blkh, nr + count);
set_blkh_free_space (blkh, get_blkh_free_space (blkh) - count * (DC_SIZE + KEY_SIZE));
mark_buffer_dirty (cur);
if (cur_bi->bi_parent) {
dc = B_N_CHILD (cur_bi->bi_parent,cur_bi->bi_position);
set_dc_child_size (dc, get_dc_child_size (dc) + count * (DC_SIZE + KEY_SIZE));
mark_buffer_dirty (cur_bi->bi_parent);
}
}
/* Delete del_num items and node pointers from buffer cur starting from *
* the first_i'th item and first_p'th pointers respectively. */
static void internal_delete_pointers_items (reiserfs_filsys_t * fs,
struct buffer_info * cur_bi,
int first_p, int first_i,
int del_num)
{
struct buffer_head * cur = cur_bi->bi_bh;
int nr;
struct block_head * blkh;
struct key * key;
struct disk_child * dc;
if ( del_num == 0 )
return;
blkh = B_BLK_HEAD(cur);
nr = get_blkh_nr_items (blkh);
if ( first_p == 0 && del_num == nr + 1 ) {
make_empty_node (cur_bi);
return;
}
/* deleting */
dc = B_N_CHILD (cur, first_p);
memmove (dc, dc + del_num, (nr + 1 - first_p - del_num) * DC_SIZE);
key = B_N_PDELIM_KEY (cur, first_i);
memmove (key, key + del_num, (nr - first_i - del_num) * KEY_SIZE + (nr + 1 - del_num) * DC_SIZE);
/* sizes, item number */
set_blkh_nr_items (blkh, get_blkh_nr_items (blkh) - del_num);
set_blkh_free_space (blkh, get_blkh_free_space (blkh) +
del_num * (KEY_SIZE + DC_SIZE));
mark_buffer_dirty (cur);
if (cur_bi->bi_parent) {
dc = B_N_CHILD (cur_bi->bi_parent, cur_bi->bi_position);
set_dc_child_size (dc, get_dc_child_size (dc) - del_num * (KEY_SIZE + DC_SIZE));
mark_buffer_dirty (cur_bi->bi_parent);
}
}
/* delete n node pointers and items starting from given position */
static void internal_delete_childs (reiserfs_filsys_t * fs,
struct buffer_info * cur_bi,
int from, int n)
{
int i_from;
i_from = (from == 0) ? from : from - 1;
/* delete n pointers starting from `from' position in CUR;
delete n keys starting from 'i_from' position in CUR;
*/
internal_delete_pointers_items (fs, cur_bi, from, i_from, n);
}
/* copy cpy_num node pointers and cpy_num - 1 items from buffer src to buffer dest
* last_first == FIRST_TO_LAST means, that we copy first items from src to tail of dest
* last_first == LAST_TO_FIRST means, that we copy last items from src to head of dest
*/
static void internal_copy_pointers_items (reiserfs_filsys_t * fs,
struct buffer_info * dest_bi,
struct buffer_head * src,
int last_first, int cpy_num)
{
/* ATTENTION! Number of node pointers in DEST is equal to number of items in DEST *
* as delimiting key have already inserted to buffer dest.*/
struct buffer_head * dest = dest_bi->bi_bh;
int nr_dest, nr_src;
int dest_order, src_order;
struct block_head * blkh;
struct key * key;
struct disk_child * dc;
nr_src = B_NR_ITEMS (src);
if ( cpy_num == 0 )
return;
/* coping */
blkh = B_BLK_HEAD (dest);
nr_dest = get_blkh_nr_items (blkh);
/*dest_order = (last_first == LAST_TO_FIRST) ? 0 : nr_dest;*/
/*src_order = (last_first == LAST_TO_FIRST) ? (nr_src - cpy_num + 1) : 0;*/
(last_first == LAST_TO_FIRST) ? (dest_order = 0, src_order = nr_src - cpy_num + 1) :
(dest_order = nr_dest, src_order = 0);
/* prepare space for cpy_num pointers */
dc = B_N_CHILD (dest, dest_order);
memmove (dc + cpy_num, dc, (nr_dest - dest_order) * DC_SIZE);
/* insert pointers */
memcpy (dc, B_N_CHILD (src, src_order), DC_SIZE * cpy_num);
/* prepare space for cpy_num - 1 item headers */
key = B_N_PDELIM_KEY(dest, dest_order);
memmove (key + cpy_num - 1, key,
KEY_SIZE * (nr_dest - dest_order) + DC_SIZE * (nr_dest + cpy_num));
/* insert headers */
memcpy (key, B_N_PDELIM_KEY (src, src_order), KEY_SIZE * (cpy_num - 1));
/* sizes, item number */
set_blkh_nr_items (blkh, get_blkh_nr_items (blkh) + cpy_num - 1);
set_blkh_free_space (blkh, get_blkh_free_space (blkh) -
(KEY_SIZE * (cpy_num - 1) + DC_SIZE * cpy_num));
mark_buffer_dirty (dest);
if (dest_bi->bi_parent) {
dc = B_N_CHILD(dest_bi->bi_parent,dest_bi->bi_position);
set_dc_child_size (dc, get_dc_child_size (dc) + KEY_SIZE * (cpy_num - 1) + DC_SIZE * cpy_num);
mark_buffer_dirty (dest_bi->bi_parent);
}
}
/* Copy cpy_num node pointers and cpy_num - 1 items from buffer src to buffer dest.
* Delete cpy_num - del_par items and node pointers from buffer src.
* last_first == FIRST_TO_LAST means, that we copy/delete first items from src.
* last_first == LAST_TO_FIRST means, that we copy/delete last items from src.
*/
static void internal_move_pointers_items (reiserfs_filsys_t * fs,
struct buffer_info * dest_bi,
struct buffer_info * src_bi,
int last_first, int cpy_num, int del_par)
{
int first_pointer;
int first_item;
internal_copy_pointers_items (fs, dest_bi, src_bi->bi_bh, last_first, cpy_num);
if (last_first == FIRST_TO_LAST) { /* shift_left occurs */
first_pointer = 0;
first_item = 0;
/* delete cpy_num - del_par pointers and keys starting for pointers with first_pointer,
for key - with first_item */
internal_delete_pointers_items (fs, src_bi, first_pointer, first_item, cpy_num - del_par);
} else { /* shift_right occurs */
int i, j;
i = ( cpy_num - del_par == ( j = B_NR_ITEMS(src_bi->bi_bh)) + 1 ) ? 0 : j - cpy_num + del_par;
internal_delete_pointers_items (fs, src_bi, j + 1 - cpy_num + del_par, i, cpy_num - del_par);
}
}
/* Insert n_src'th key of buffer src before n_dest'th key of buffer dest. */
static void internal_insert_key (reiserfs_filsys_t * fs,
struct buffer_info * dest_bi,
int dest_position_before, /* insert key before key with n_dest number */
struct buffer_head * src,
int src_position )
{
struct buffer_head * dest = dest_bi->bi_bh;
int nr;
struct block_head * blkh;
struct key * key;
blkh = B_BLK_HEAD(dest);
nr = get_blkh_nr_items (blkh);
/* prepare space for inserting key */
key = B_N_PDELIM_KEY (dest, dest_position_before);
memmove (key + 1, key, (nr - dest_position_before) * KEY_SIZE + (nr + 1) * DC_SIZE);
/* insert key */
memcpy (key, B_N_PDELIM_KEY(src, src_position), KEY_SIZE);
/* Change dirt, free space, item number fields. */
set_blkh_nr_items (blkh, get_blkh_nr_items (blkh) + 1);
set_blkh_free_space (blkh, get_blkh_free_space (blkh) - KEY_SIZE);
mark_buffer_dirty (dest);
if (dest_bi->bi_parent) {
struct disk_child * dc;
dc = B_N_CHILD(dest_bi->bi_parent,dest_bi->bi_position);
set_dc_child_size (dc, get_dc_child_size (dc) + KEY_SIZE);
mark_buffer_dirty (dest_bi->bi_parent);
}
}
/* Insert d_key'th (delimiting) key from buffer cfl to tail of dest.
* Copy pointer_amount node pointers and pointer_amount - 1 items from buffer src to buffer dest.
* Replace d_key'th key in buffer cfl.
* Delete pointer_amount items and node pointers from buffer src.
*/
/* this can be invoked both to shift from S to L and from R to S */
static void internal_shift_left (int mode, /* INTERNAL_FROM_S_TO_L | INTERNAL_FROM_R_TO_S */
struct tree_balance * tb, int h,
int pointer_amount)
{
struct buffer_info dest_bi, src_bi;
struct buffer_head * cf;
int d_key_position;
internal_define_dest_src_infos (mode, tb, h, &dest_bi, &src_bi, &d_key_position, &cf);
/*printk("pointer_amount = %d\n",pointer_amount);*/
if (pointer_amount) {
/* insert delimiting key from common father of dest and src to node dest into position B_NR_ITEM(dest) */
internal_insert_key (tb->tb_fs, &dest_bi, B_NR_ITEMS(dest_bi.bi_bh), cf, d_key_position);
if (B_NR_ITEMS(src_bi.bi_bh) == pointer_amount - 1) {
if (src_bi.bi_position/*src->b_item_order*/ == 0)
replace_key (tb->tb_fs, cf, d_key_position, src_bi.bi_parent/*src->b_parent*/, 0);
} else
replace_key (tb->tb_fs, cf, d_key_position, src_bi.bi_bh, pointer_amount - 1);
}
/* last parameter is del_parameter */
internal_move_pointers_items (tb->tb_fs, &dest_bi, &src_bi, FIRST_TO_LAST, pointer_amount, 0);
}
/* Insert delimiting key to L[h].
* Copy n node pointers and n - 1 items from buffer S[h] to L[h].
* Delete n - 1 items and node pointers from buffer S[h].
*/
/* it always shifts from S[h] to L[h] */
static void internal_shift1_left (struct tree_balance * tb,
int h, int pointer_amount)
{
struct buffer_info dest_bi, src_bi;
struct buffer_head * cf;
int d_key_position;
internal_define_dest_src_infos (INTERNAL_SHIFT_FROM_S_TO_L, tb, h, &dest_bi, &src_bi, &d_key_position, &cf);
if ( pointer_amount > 0 ) /* insert lkey[h]-th key from CFL[h] to left neighbor L[h] */
internal_insert_key (tb->tb_fs, &dest_bi, B_NR_ITEMS(dest_bi.bi_bh), cf, d_key_position);
/* last parameter is del_parameter */
internal_move_pointers_items (tb->tb_fs, &dest_bi, &src_bi, FIRST_TO_LAST, pointer_amount, 1);
}
/* Insert d_key'th (delimiting) key from buffer cfr to head of dest.
* Copy n node pointers and n - 1 items from buffer src to buffer dest.
* Replace d_key'th key in buffer cfr.
* Delete n items and node pointers from buffer src.
*/
static void internal_shift_right (int mode, /* INTERNAL_FROM_S_TO_R | INTERNAL_FROM_L_TO_S */
struct tree_balance * tb, int h,
int pointer_amount)
{
struct buffer_info dest_bi, src_bi;
struct buffer_head * cf;
int d_key_position;
int nr;
internal_define_dest_src_infos (mode, tb, h, &dest_bi, &src_bi, &d_key_position, &cf);
nr = B_NR_ITEMS (src_bi.bi_bh);
if (pointer_amount > 0) {
/* insert delimiting key from common father of dest and src to dest node into position 0 */
internal_insert_key (tb->tb_fs, &dest_bi, 0, cf, d_key_position);
if (nr == pointer_amount - 1) {
/* when S[h] disappers replace left delemiting key as well */
if (tb->CFL[h])
replace_key(tb->tb_fs, cf, d_key_position, tb->CFL[h], tb->lkey[h]);
} else
replace_key(tb->tb_fs, cf, d_key_position, src_bi.bi_bh, nr - pointer_amount);
}
/* last parameter is del_parameter */
internal_move_pointers_items (tb->tb_fs, &dest_bi, &src_bi, LAST_TO_FIRST, pointer_amount, 0);
}
/* Insert delimiting key to R[h].
* Copy n node pointers and n - 1 items from buffer S[h] to R[h].
* Delete n - 1 items and node pointers from buffer S[h].
*/
/* it always shift from S[h] to R[h] */
static void internal_shift1_right (struct tree_balance * tb,
int h, int pointer_amount)
{
struct buffer_info dest_bi, src_bi;
struct buffer_head * cf;
int d_key_position;
internal_define_dest_src_infos (INTERNAL_SHIFT_FROM_S_TO_R, tb, h, &dest_bi, &src_bi, &d_key_position, &cf);
if (pointer_amount > 0) /* insert rkey from CFR[h] to right neighbor R[h] */
internal_insert_key (tb->tb_fs, &dest_bi, 0, cf, d_key_position);
/* last parameter is del_parameter */
internal_move_pointers_items (tb->tb_fs, &dest_bi, &src_bi, LAST_TO_FIRST, pointer_amount, 1);
}
/* Delete insert_num node pointers together with their left items
* and balance current node.*/
static void balance_internal_when_delete (struct tree_balance * tb,
int h, int child_pos)
{
int insert_num;
int n;
struct buffer_head * tbSh = PATH_H_PBUFFER (tb->tb_path, h);
struct buffer_info bi;
insert_num = tb->insert_size[h] / ((int)(DC_SIZE + KEY_SIZE));
/* delete child-node-pointer(s) together with their left item(s) */
bi.bi_bh = tbSh;
bi.bi_parent = PATH_H_PPARENT (tb->tb_path, h);
bi.bi_position = PATH_H_POSITION (tb->tb_path, h + 1);
internal_delete_childs (tb->tb_fs, &bi, child_pos, -insert_num);
n = B_NR_ITEMS(tbSh);
if ( tb->lnum[h] == 0 && tb->rnum[h] == 0 ) {
if ( tb->blknum[h] == 0 ) {
/* node S[h] (root of the tree) is empty now */
struct buffer_head *new_root;
struct reiserfs_super_block * sb;
/* choose a new root */
if ( ! tb->L[h-1] || ! B_NR_ITEMS(tb->L[h-1]) )
new_root = tb->R[h-1];
else
new_root = tb->L[h-1];
/* update super block's tree height and pointer to a root block */
sb = tb->tb_fs->fs_ondisk_sb;
set_sb_root_block (sb, new_root->b_blocknr);
set_sb_tree_height (sb, get_sb_tree_height (sb) - 1);
mark_buffer_dirty (tb->tb_fs->fs_super_bh);
tb->tb_fs->fs_dirt = 1;
/* mark buffer S[h] not uptodate and put it in free list */
reiserfs_invalidate_buffer(tb, tbSh, 1);
return;
}
return;
}
if ( tb->L[h] && tb->lnum[h] == -B_NR_ITEMS(tb->L[h]) - 1 ) { /* join S[h] with L[h] */
internal_shift_left (INTERNAL_SHIFT_FROM_S_TO_L, tb, h, n + 1);/*tb->L[h], tb->CFL[h], tb->lkey[h], tb->S[h], n+1);*/
reiserfs_invalidate_buffer(tb, tbSh, 1); /* preserve not needed, internal, 1 mean free block */
return;
}
if ( tb->R[h] && tb->rnum[h] == -B_NR_ITEMS(tb->R[h]) - 1 ) { /* join S[h] with R[h] */
internal_shift_right (INTERNAL_SHIFT_FROM_S_TO_R, tb, h, n + 1);
reiserfs_invalidate_buffer (tb, tbSh, 1);
return;
}
if ( tb->lnum[h] < 0 ) { /* borrow from left neighbor L[h] */
internal_shift_right (INTERNAL_SHIFT_FROM_L_TO_S, tb, h, -tb->lnum[h]);
return;
}
if ( tb->rnum[h] < 0 ) { /* borrow from right neighbor R[h] */
internal_shift_left (INTERNAL_SHIFT_FROM_R_TO_S, tb, h, -tb->rnum[h]);/*tb->S[h], tb->CFR[h], tb->rkey[h], tb->R[h], -tb->rnum[h]);*/
return;
}
if ( tb->lnum[h] > 0 ) { /* split S[h] into two parts and put them into neighbors */
internal_shift_left (INTERNAL_SHIFT_FROM_S_TO_L, tb, h, tb->lnum[h]);/*tb->L[h], tb->CFL[h], tb->lkey[h], tb->S[h], tb->lnum[h]);*/
internal_shift_right (INTERNAL_SHIFT_FROM_S_TO_R, tb, h, tb->rnum[h]);
reiserfs_invalidate_buffer (tb, tbSh, 1);
return;
}
reiserfs_panic ("balance_internal_when_delete", "unexpected tb->lnum[%d]==%d or tb->rnum[%d]==%d",
h, tb->lnum[h], h, tb->rnum[h]);
}
/* Replace delimiting key of buffers L[h] and S[h] by the given key.*/
void replace_lkey (struct tree_balance * tb,
int h, struct item_head * key)
{
if (B_NR_ITEMS(PATH_H_PBUFFER(tb->tb_path, h)) == 0)
return;
memcpy (B_N_PDELIM_KEY(tb->CFL[h],tb->lkey[h]), key, KEY_SIZE);
mark_buffer_dirty (tb->CFL[h]);
}
/* Replace delimiting key of buffers S[h] and R[h] by the given key.*/
void replace_rkey (struct tree_balance * tb,
int h, struct item_head * key)
{
memcpy (B_N_PDELIM_KEY(tb->CFR[h],tb->rkey[h]), key, KEY_SIZE);
mark_buffer_dirty (tb->CFR[h]);
}
int balance_internal (struct tree_balance * tb, /* tree_balance structure */
int h, /* level of the tree */
int child_pos,
struct item_head * insert_key, /* key for insertion on higher level */
struct buffer_head ** insert_ptr) /* node for insertion on higher level*/
/* if inserting/pasting
{
child_pos is the position of the node-pointer in S[h] that *
pointed to S[h-1] before balancing of the h-1 level; *
this means that new pointers and items must be inserted AFTER *
child_pos
}
else
{
it is the position of the leftmost pointer that must be deleted (together with
its corresponding key to the left of the pointer)
as a result of the previous level's balancing.
}
*/
{
struct buffer_head * tbSh = PATH_H_PBUFFER (tb->tb_path, h);
struct buffer_info bi;
int order; /* we return this: it is 0 if there is no S[h], else it is tb->S[h]->b_item_order */
int insert_num, n, k;
struct buffer_head * S_new;
struct item_head new_insert_key;
struct buffer_head * new_insert_ptr = NULL;
struct item_head * new_insert_key_addr = insert_key;
order = ( tbSh ) ? PATH_H_POSITION (tb->tb_path, h + 1)/*tb->S[h]->b_item_order*/ : 0;
/* Using insert_size[h] calculate the number insert_num of items
that must be inserted to or deleted from S[h]. */
insert_num = tb->insert_size[h]/((int)(KEY_SIZE + DC_SIZE));
/* Check whether insert_num is proper **/
/* Make balance in case insert_num < 0 */
if ( insert_num < 0 ) {
balance_internal_when_delete (tb, h, child_pos);
return order;
}
k = 0;
if ( tb->lnum[h] > 0 ) {
/* shift lnum[h] items from S[h] to the left neighbor L[h].
check how many of new items fall into L[h] or CFL[h] after shifting */
n = get_blkh_nr_items (B_BLK_HEAD(tb->L[h])); /* number of items in L[h] */
if ( tb->lnum[h] <= child_pos ) {
/* new items don't fall into L[h] or CFL[h] */
internal_shift_left (INTERNAL_SHIFT_FROM_S_TO_L, tb, h, tb->lnum[h]);
child_pos -= tb->lnum[h];
} else if ( tb->lnum[h] > child_pos + insert_num ) {
/* all new items fall into L[h] */
internal_shift_left (INTERNAL_SHIFT_FROM_S_TO_L, tb, h, tb->lnum[h] - insert_num);
/* insert insert_num keys and node-pointers into L[h] */
bi.bi_bh = tb->L[h];
bi.bi_parent = tb->FL[h];
bi.bi_position = get_left_neighbor_position (tb, h);
internal_insert_childs (tb->tb_fs, &bi,/*tb->L[h], tb->S[h-1]->b_next*/ n + child_pos + 1,
insert_num,insert_key,insert_ptr);
insert_num = 0;
} else {
struct disk_child * dc;
/* some items fall into L[h] or CFL[h], but some don't fall */
internal_shift1_left (tb, h, child_pos + 1);
/* calculate number of new items that fall into L[h] */
k = tb->lnum[h] - child_pos - 1;
bi.bi_bh = tb->L[h];
bi.bi_parent = tb->FL[h];
bi.bi_position = get_left_neighbor_position (tb, h);
internal_insert_childs (tb->tb_fs, &bi,/*tb->L[h], tb->S[h-1]->b_next,*/ n + child_pos + 1,k,
insert_key,insert_ptr);
replace_lkey(tb, h, insert_key + k);
/* replace the first node-ptr in S[h] by node-ptr to insert_ptr[k] */
dc = B_N_CHILD(tbSh, 0);
set_dc_child_size (dc, MAX_CHILD_SIZE(insert_ptr[k]->b_size) -
get_blkh_free_space (B_BLK_HEAD(insert_ptr[k])));
set_dc_child_blocknr (dc, insert_ptr[k]->b_blocknr);
mark_buffer_dirty (tbSh);
k++;
insert_key += k;
insert_ptr += k;
insert_num -= k;
child_pos = 0;
}
} /* tb->lnum[h] > 0 */
if ( tb->rnum[h] > 0 ) {
/*shift rnum[h] items from S[h] to the right neighbor R[h]*/
/* check how many of new items fall into R or CFR after shifting */
n = get_blkh_nr_items (B_BLK_HEAD (tbSh)); /* number of items in S[h] */
if ( n - tb->rnum[h] >= child_pos )
/* new items fall into S[h] */
/*internal_shift_right(tb,h,tbSh,tb->CFR[h],tb->rkey[h],tb->R[h],tb->rnum[h]);*/
internal_shift_right (INTERNAL_SHIFT_FROM_S_TO_R, tb, h, tb->rnum[h]);
else
if ( n + insert_num - tb->rnum[h] < child_pos )
{
/* all new items fall into R[h] */
internal_shift_right (INTERNAL_SHIFT_FROM_S_TO_R, tb, h, tb->rnum[h] - insert_num);
/* insert insert_num keys and node-pointers into R[h] */
bi.bi_bh = tb->R[h];
bi.bi_parent = tb->FR[h];
bi.bi_position = get_right_neighbor_position (tb, h);
internal_insert_childs (tb->tb_fs, &bi, /*tb->R[h],tb->S[h-1]->b_next*/ child_pos - n - insert_num + tb->rnum[h] - 1,
insert_num,insert_key,insert_ptr);
insert_num = 0;
}
else
{
struct disk_child * dc;
/* one of the items falls into CFR[h] */
internal_shift1_right(tb, h, n - child_pos + 1);
/* calculate number of new items that fall into R[h] */
k = tb->rnum[h] - n + child_pos - 1;
bi.bi_bh = tb->R[h];
bi.bi_parent = tb->FR[h];
bi.bi_position = get_right_neighbor_position (tb, h);
internal_insert_childs (tb->tb_fs, &bi, /*tb->R[h], tb->R[h]->b_child,*/ 0, k, insert_key + 1, insert_ptr + 1);
replace_rkey(tb, h, insert_key + insert_num - k - 1);
/* replace the first node-ptr in R[h] by node-ptr insert_ptr[insert_num-k-1]*/
dc = B_N_CHILD(tb->R[h], 0);
set_dc_child_size (dc, MAX_CHILD_SIZE(insert_ptr[insert_num-k-1]->b_size) -
get_blkh_free_space (B_BLK_HEAD(insert_ptr[insert_num-k-1])));
set_dc_child_blocknr (dc, insert_ptr[insert_num-k-1]->b_blocknr);
mark_buffer_dirty (tb->R[h]);
insert_num -= (k + 1);
}
}
/** Fill new node that appears instead of S[h] **/
if ( ! tb->blknum[h] )
{ /* node S[h] is empty now */
/* Mark buffer as invalid and put it to head of free list. */
reiserfs_invalidate_buffer(tb, tbSh, 1);/* do not preserve, internal node*/
return order;
}
if ( ! tbSh ) {
/* create new root */
struct disk_child * dc;
struct buffer_head * tbSh_1 = PATH_H_PBUFFER (tb->tb_path, h - 1);
struct reiserfs_super_block * sb;
if ( tb->blknum[h] != 1 )
reiserfs_panic(0, "balance_internal", "One new node required for creating the new root");
/* S[h] = empty buffer from the list FEB. */
tbSh = get_FEB (tb);
set_blkh_level (B_BLK_HEAD(tbSh), h + 1);
/* Put the unique node-pointer to S[h] that points to S[h-1]. */
dc = B_N_CHILD(tbSh, 0);
set_dc_child_size (dc, MAX_CHILD_SIZE (tbSh_1->b_size) - get_blkh_free_space (B_BLK_HEAD(tbSh_1)));
set_dc_child_blocknr (dc, tbSh_1->b_blocknr);
tb->insert_size[h] -= DC_SIZE;
set_blkh_free_space (B_BLK_HEAD(tbSh),
get_blkh_free_space (B_BLK_HEAD(tbSh)) - DC_SIZE);
mark_buffer_dirty (tbSh);
/* put new root into path structure */
PATH_OFFSET_PBUFFER(tb->tb_path, ILLEGAL_PATH_ELEMENT_OFFSET) = tbSh;
/* Change root in structure super block. */
sb = tb->tb_fs->fs_ondisk_sb;
set_sb_root_block (sb, tbSh->b_blocknr);
set_sb_tree_height (sb, get_sb_tree_height (sb) + 1);
mark_buffer_dirty (tb->tb_fs->fs_super_bh);
tb->tb_fs->fs_dirt = 1;
}
if ( tb->blknum[h] == 2 ) {
int snum;
struct buffer_info dest_bi, src_bi;
/* S_new = free buffer from list FEB */
S_new = get_FEB(tb);
set_blkh_level (B_BLK_HEAD(S_new), h + 1);
dest_bi.bi_bh = S_new;
dest_bi.bi_parent = 0;
dest_bi.bi_position = 0;
src_bi.bi_bh = tbSh;
src_bi.bi_parent = PATH_H_PPARENT (tb->tb_path, h);
src_bi.bi_position = PATH_H_POSITION (tb->tb_path, h + 1);
n = get_blkh_nr_items (B_BLK_HEAD(tbSh)); /* number of items in S[h] */
snum = (insert_num + n + 1)/2;
if ( n - snum >= child_pos ) {
/* new items don't fall into S_new */
/* store the delimiting key for the next level */
/* new_insert_key = (n - snum)'th key in S[h] */
memcpy (&new_insert_key,B_N_PDELIM_KEY(tbSh,n - snum),
KEY_SIZE);
/* last parameter is del_par */
internal_move_pointers_items (tb->tb_fs, &dest_bi, &src_bi, LAST_TO_FIRST, snum, 0);
} else if ( n + insert_num - snum < child_pos ) {
/* all new items fall into S_new */
/* store the delimiting key for the next level */
/* new_insert_key = (n + insert_item - snum)'th key in S[h] */
memcpy(&new_insert_key,B_N_PDELIM_KEY(tbSh,n + insert_num - snum),
KEY_SIZE);
/* last parameter is del_par */
internal_move_pointers_items (tb->tb_fs, &dest_bi, &src_bi, LAST_TO_FIRST, snum - insert_num, 0);
/* internal_move_pointers_items(S_new,tbSh,1,snum - insert_num,0);*/
/* insert insert_num keys and node-pointers into S_new */
internal_insert_childs (tb->tb_fs, &dest_bi, /*S_new,tb->S[h-1]->b_next,*/child_pos - n - insert_num + snum - 1,
insert_num,insert_key,insert_ptr);
insert_num = 0;
} else {
struct disk_child * dc;
/* some items fall into S_new, but some don't fall */
/* last parameter is del_par */
internal_move_pointers_items (tb->tb_fs, &dest_bi, &src_bi, LAST_TO_FIRST, n - child_pos + 1, 1);
/* internal_move_pointers_items(S_new,tbSh,1,n - child_pos + 1,1);*/
/* calculate number of new items that fall into S_new */
k = snum - n + child_pos - 1;
internal_insert_childs (tb->tb_fs, &dest_bi, /*S_new,*/ 0, k, insert_key + 1, insert_ptr+1);
/* new_insert_key = insert_key[insert_num - k - 1] */
memcpy(&new_insert_key,insert_key + insert_num - k - 1,
KEY_SIZE);
/* replace first node-ptr in S_new by node-ptr to insert_ptr[insert_num-k-1] */
dc = B_N_CHILD(S_new,0);
set_dc_child_size (dc, MAX_CHILD_SIZE(insert_ptr[insert_num-k-1]->b_size) -
get_blkh_free_space (B_BLK_HEAD(insert_ptr[insert_num-k-1])));
set_dc_child_blocknr (dc, insert_ptr[insert_num-k-1]->b_blocknr);
mark_buffer_dirty (S_new);
insert_num -= (k + 1);
}
/* new_insert_ptr = node_pointer to S_new */
new_insert_ptr = S_new;
/*
S_new->b_count --;
*/
/*brelse(S_new);*/
}
n = get_blkh_nr_items (B_BLK_HEAD(tbSh)); /*number of items in S[h] */
if ( -1 <= child_pos && child_pos <= n && insert_num > 0 ) {
bi.bi_bh = tbSh;
bi.bi_parent = PATH_H_PPARENT (tb->tb_path, h);
bi.bi_position = PATH_H_POSITION (tb->tb_path, h + 1);
if (child_pos == -1) {
/* this is a little different from original do_balance:
here we insert the minimal keys in the tree, that has never happened when file system works */
if (tb->CFL[h-1] || insert_num != 1 || h != 1)
die ("balance_internal: invalid child_pos");
/* insert_child (tb->S[h], tb->S[h-1], child_pos, insert_num, B_N_ITEM_HEAD(tb->S[0],0), insert_ptr);*/
internal_insert_childs (tb->tb_fs, &bi, child_pos, insert_num,
B_N_PITEM_HEAD (PATH_PLAST_BUFFER (tb->tb_path), 0), insert_ptr);
} else
internal_insert_childs (tb->tb_fs, &bi, child_pos,insert_num,insert_key,insert_ptr);
}
memcpy (new_insert_key_addr,&new_insert_key,KEY_SIZE);
insert_ptr[0] = new_insert_ptr;
return order;
}
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