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ibalance.c
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ibalance.c
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/*
* 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:
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);
break;
case INTERNAL_INSERT_TO_S:
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);
break;
case INTERNAL_INSERT_TO_R:
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);
break;
default:
reiserfs_panic(tb->tb_sb,
"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(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 reiserfs_key *ih;
struct disk_child new_dc[2];
struct disk_child *dc;
int i;
if (count <= 0)
return;
blkh = B_BLK_HEAD(cur);
nr = blkh_nr_item(blkh);
RFALSE(count > 2, "too many children (%d) are to be inserted", count);
RFALSE(B_FREE_SPACE(cur) < count * (KEY_SIZE + DC_SIZE),
"no enough free space (%d), needed %d bytes",
B_FREE_SPACE(cur), count * (KEY_SIZE + DC_SIZE));
/* prepare space for count disk_child */
dc = B_N_CHILD(cur, to + 1);
memmove(dc + count, dc, (nr + 1 - (to + 1)) * DC_SIZE);
/* copy to_be_insert disk children */
for (i = 0; i < count; i++) {
put_dc_size(&(new_dc[i]),
MAX_CHILD_SIZE(bh[i]) - B_FREE_SPACE(bh[i]));
put_dc_block_number(&(new_dc[i]), bh[i]->b_blocknr);
}
memcpy(dc, new_dc, DC_SIZE * count);
/* prepare space for count items */
ih = B_N_PDELIM_KEY(cur, ((to == -1) ? 0 : to));
memmove(ih + count, ih,
(nr - to) * KEY_SIZE + (nr + 1 + count) * DC_SIZE);
/* copy item headers (keys) */
memcpy(ih, inserted, KEY_SIZE);
if (count > 1)
memcpy(ih + 1, inserted + 1, KEY_SIZE);
/* sizes, item number */
set_blkh_nr_item(blkh, blkh_nr_item(blkh) + count);
set_blkh_free_space(blkh,
blkh_free_space(blkh) - count * (DC_SIZE +
KEY_SIZE));
do_balance_mark_internal_dirty(cur_bi->tb, cur, 0);
/*&&&&&&&&&&&&&&&&&&&&&&&& */
check_internal(cur);
/*&&&&&&&&&&&&&&&&&&&&&&&& */
if (cur_bi->bi_parent) {
struct disk_child *t_dc =
B_N_CHILD(cur_bi->bi_parent, cur_bi->bi_position);
put_dc_size(t_dc,
dc_size(t_dc) + (count * (DC_SIZE + KEY_SIZE)));
do_balance_mark_internal_dirty(cur_bi->tb, cur_bi->bi_parent,
0);
/*&&&&&&&&&&&&&&&&&&&&&&&& */
check_internal(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(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 reiserfs_key *key;
struct disk_child *dc;
RFALSE(cur == NULL, "buffer is 0");
RFALSE(del_num < 0,
"negative number of items (%d) can not be deleted", del_num);
RFALSE(first_p < 0 || first_p + del_num > B_NR_ITEMS(cur) + 1
|| first_i < 0,
"first pointer order (%d) < 0 or "
"no so many pointers (%d), only (%d) or "
"first key order %d < 0", first_p, first_p + del_num,
B_NR_ITEMS(cur) + 1, first_i);
if (del_num == 0)
return;
blkh = B_BLK_HEAD(cur);
nr = blkh_nr_item(blkh);
if (first_p == 0 && del_num == nr + 1) {
RFALSE(first_i != 0,
"1st deleted key must have order 0, not %d", first_i);
make_empty_node(cur_bi);
return;
}
RFALSE(first_i + del_num > B_NR_ITEMS(cur),
"first_i = %d del_num = %d "
"no so many keys (%d) in the node (%b)(%z)",
first_i, del_num, first_i + del_num, cur, cur);
/* 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_item(blkh, blkh_nr_item(blkh) - del_num);
set_blkh_free_space(blkh,
blkh_free_space(blkh) +
(del_num * (KEY_SIZE + DC_SIZE)));
do_balance_mark_internal_dirty(cur_bi->tb, cur, 0);
/*&&&&&&&&&&&&&&&&&&&&&&& */
check_internal(cur);
/*&&&&&&&&&&&&&&&&&&&&&&& */
if (cur_bi->bi_parent) {
struct disk_child *t_dc;
t_dc = B_N_CHILD(cur_bi->bi_parent, cur_bi->bi_position);
put_dc_size(t_dc,
dc_size(t_dc) - (del_num * (KEY_SIZE + DC_SIZE)));
do_balance_mark_internal_dirty(cur_bi->tb, cur_bi->bi_parent,
0);
/*&&&&&&&&&&&&&&&&&&&&&&&& */
check_internal(cur_bi->bi_parent);
/*&&&&&&&&&&&&&&&&&&&&&&&& */
}
}
/* delete n node pointers and items starting from given position */
static void internal_delete_childs(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(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(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 reiserfs_key *key;
struct disk_child *dc;
nr_src = B_NR_ITEMS(src);
RFALSE(dest == NULL || src == NULL,
"src (%p) or dest (%p) buffer is 0", src, dest);
RFALSE(last_first != FIRST_TO_LAST && last_first != LAST_TO_FIRST,
"invalid last_first parameter (%d)", last_first);
RFALSE(nr_src < cpy_num - 1,
"no so many items (%d) in src (%d)", cpy_num, nr_src);
RFALSE(cpy_num < 0, "cpy_num less than 0 (%d)", cpy_num);
RFALSE(cpy_num - 1 + B_NR_ITEMS(dest) > (int)MAX_NR_KEY(dest),
"cpy_num (%d) + item number in dest (%d) can not be > MAX_NR_KEY(%d)",
cpy_num, B_NR_ITEMS(dest), MAX_NR_KEY(dest));
if (cpy_num == 0)
return;
/* coping */
blkh = B_BLK_HEAD(dest);
nr_dest = blkh_nr_item(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_item(blkh, blkh_nr_item(blkh) + (cpy_num - 1));
set_blkh_free_space(blkh,
blkh_free_space(blkh) - (KEY_SIZE * (cpy_num - 1) +
DC_SIZE * cpy_num));
do_balance_mark_internal_dirty(dest_bi->tb, dest, 0);
/*&&&&&&&&&&&&&&&&&&&&&&&& */
check_internal(dest);
/*&&&&&&&&&&&&&&&&&&&&&&&& */
if (dest_bi->bi_parent) {
struct disk_child *t_dc;
t_dc = B_N_CHILD(dest_bi->bi_parent, dest_bi->bi_position);
put_dc_size(t_dc,
dc_size(t_dc) + (KEY_SIZE * (cpy_num - 1) +
DC_SIZE * cpy_num));
do_balance_mark_internal_dirty(dest_bi->tb, dest_bi->bi_parent,
0);
/*&&&&&&&&&&&&&&&&&&&&&&&& */
check_internal(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(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(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(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(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(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 reiserfs_key *key;
RFALSE(dest == NULL || src == NULL,
"source(%p) or dest(%p) buffer is 0", src, dest);
RFALSE(dest_position_before < 0 || src_position < 0,
"source(%d) or dest(%d) key number less than 0",
src_position, dest_position_before);
RFALSE(dest_position_before > B_NR_ITEMS(dest) ||
src_position >= B_NR_ITEMS(src),
"invalid position in dest (%d (key number %d)) or in src (%d (key number %d))",
dest_position_before, B_NR_ITEMS(dest),
src_position, B_NR_ITEMS(src));
RFALSE(B_FREE_SPACE(dest) < KEY_SIZE,
"no enough free space (%d) in dest buffer", B_FREE_SPACE(dest));
blkh = B_BLK_HEAD(dest);
nr = blkh_nr_item(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_item(blkh, blkh_nr_item(blkh) + 1);
set_blkh_free_space(blkh, blkh_free_space(blkh) - KEY_SIZE);
do_balance_mark_internal_dirty(dest_bi->tb, dest, 0);
if (dest_bi->bi_parent) {
struct disk_child *t_dc;
t_dc = B_N_CHILD(dest_bi->bi_parent, dest_bi->bi_position);
put_dc_size(t_dc, dc_size(t_dc) + KEY_SIZE);
do_balance_mark_internal_dirty(dest_bi->tb, dest_bi->bi_parent,
0);
}
}
/* 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(&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, cf, d_key_position,
src_bi.
bi_parent /*src->b_parent */ , 0);
} else
replace_key(tb, cf, d_key_position, src_bi.bi_bh,
pointer_amount - 1);
}
/* last parameter is del_parameter */
internal_move_pointers_items(&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(&dest_bi, B_NR_ITEMS(dest_bi.bi_bh), cf,
d_key_position);
/* internal_insert_key (tb->L[h], B_NR_ITEM(tb->L[h]), tb->CFL[h], tb->lkey[h]); */
/* last parameter is del_parameter */
internal_move_pointers_items(&dest_bi, &src_bi, FIRST_TO_LAST,
pointer_amount, 1);
/* internal_move_pointers_items (tb->L[h], tb->S[h], 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(&dest_bi, 0, cf, d_key_position);
if (nr == pointer_amount - 1) {
RFALSE(src_bi.bi_bh != PATH_H_PBUFFER(tb->tb_path, h) /*tb->S[h] */ ||
dest_bi.bi_bh != tb->R[h],
"src (%p) must be == tb->S[h](%p) when it disappears",
src_bi.bi_bh, PATH_H_PBUFFER(tb->tb_path, h));
/* when S[h] disappers replace left delemiting key as well */
if (tb->CFL[h])
replace_key(tb, cf, d_key_position, tb->CFL[h],
tb->lkey[h]);
} else
replace_key(tb, cf, d_key_position, src_bi.bi_bh,
nr - pointer_amount);
}
/* last parameter is del_parameter */
internal_move_pointers_items(&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(&dest_bi, 0, cf, d_key_position);
/* internal_insert_key (tb->R[h], 0, tb->CFR[h], tb->rkey[h]); */
/* last parameter is del_parameter */
internal_move_pointers_items(&dest_bi, &src_bi, LAST_TO_FIRST,
pointer_amount, 1);
/* internal_move_pointers_items (tb->R[h], tb->S[h], 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.tb = tb;
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(&bi, child_pos, -insert_num);
RFALSE(tb->blknum[h] > 1,
"tb->blknum[%d]=%d when insert_size < 0", h, tb->blknum[h]);
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;
RFALSE(n
|| B_FREE_SPACE(tbSh) !=
MAX_CHILD_SIZE(tbSh) - DC_SIZE,
"buffer must have only 0 keys (%d)", n);
RFALSE(bi.bi_parent, "root has parent (%p)",
bi.bi_parent);
/* 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];
/* switch super block's tree root block number to the new value */
PUT_SB_ROOT_BLOCK(tb->tb_sb, new_root->b_blocknr);
//REISERFS_SB(tb->tb_sb)->s_rs->s_tree_height --;
PUT_SB_TREE_HEIGHT(tb->tb_sb,
SB_TREE_HEIGHT(tb->tb_sb) - 1);
do_balance_mark_sb_dirty(tb,
REISERFS_SB(tb->tb_sb)->s_sbh,
1);
/*&&&&&&&&&&&&&&&&&&&&&& */
if (h > 1)
/* use check_internal if new root is an internal node */
check_internal(new_root);
/*&&&&&&&&&&&&&&&&&&&&&& */
/* do what is needed for buffer thrown from tree */
reiserfs_invalidate_buffer(tb, tbSh);
return;
}
return;
}
if (tb->L[h] && tb->lnum[h] == -B_NR_ITEMS(tb->L[h]) - 1) { /* join S[h] with L[h] */
RFALSE(tb->rnum[h] != 0,
"invalid tb->rnum[%d]==%d when joining S[h] with L[h]",
h, tb->rnum[h]);
internal_shift_left(INTERNAL_SHIFT_FROM_S_TO_L, tb, h, n + 1);
reiserfs_invalidate_buffer(tb, tbSh);
return;
}
if (tb->R[h] && tb->rnum[h] == -B_NR_ITEMS(tb->R[h]) - 1) { /* join S[h] with R[h] */
RFALSE(tb->lnum[h] != 0,
"invalid tb->lnum[%d]==%d when joining S[h] with R[h]",
h, tb->lnum[h]);
internal_shift_right(INTERNAL_SHIFT_FROM_S_TO_R, tb, h, n + 1);
reiserfs_invalidate_buffer(tb, tbSh);
return;
}
if (tb->lnum[h] < 0) { /* borrow from left neighbor L[h] */
RFALSE(tb->rnum[h] != 0,
"wrong tb->rnum[%d]==%d when borrow from L[h]", h,
tb->rnum[h]);
/*internal_shift_right (tb, h, tb->L[h], tb->CFL[h], tb->lkey[h], tb->S[h], -tb->lnum[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] */
RFALSE(tb->lnum[h] != 0,
"invalid tb->lnum[%d]==%d when borrow from R[h]",
h, tb->lnum[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 */
RFALSE(tb->rnum[h] == 0 || tb->lnum[h] + tb->rnum[h] != n + 1,
"invalid tb->lnum[%d]==%d or tb->rnum[%d]==%d when S[h](item number == %d) is split between them",
h, tb->lnum[h], h, tb->rnum[h], n);
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);
return;
}
reiserfs_panic(tb->tb_sb,
"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.*/
static void replace_lkey(struct tree_balance *tb, int h, struct item_head *key)
{
RFALSE(tb->L[h] == NULL || tb->CFL[h] == NULL,
"L[h](%p) and CFL[h](%p) must exist in replace_lkey",
tb->L[h], tb->CFL[h]);
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);
do_balance_mark_internal_dirty(tb, tb->CFL[h], 0);
}
/* Replace delimiting key of buffers S[h] and R[h] by the given key.*/
static void replace_rkey(struct tree_balance *tb, int h, struct item_head *key)
{
RFALSE(tb->R[h] == NULL || tb->CFR[h] == NULL,
"R[h](%p) and CFR[h](%p) must exist in replace_rkey",
tb->R[h], tb->CFR[h]);
RFALSE(B_NR_ITEMS(tb->R[h]) == 0,
"R[h] can not be empty if it exists (item number=%d)",
B_NR_ITEMS(tb->R[h]));
memcpy(B_N_PDELIM_KEY(tb->CFR[h], tb->rkey[h]), key, KEY_SIZE);
do_balance_mark_internal_dirty(tb, tb->CFR[h], 0);
}
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;
RFALSE(h < 1, "h (%d) can not be < 1 on internal level", h);
PROC_INFO_INC(tb->tb_sb, balance_at[h]);
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 * */
RFALSE(insert_num < -2 || insert_num > 2,
"incorrect number of items inserted to the internal node (%d)",
insert_num);
RFALSE(h > 1 && (insert_num > 1 || insert_num < -1),
"incorrect number of items (%d) inserted to the internal node on a level (h=%d) higher than last internal level",
insert_num, h);
/* 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 = B_NR_ITEMS(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]);
/*internal_shift_left (tb->L[h],tb->CFL[h],tb->lkey[h],tbSh,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);
/* internal_shift_left(tb->L[h],tb->CFL[h],tb->lkey[h],tbSh,
tb->lnum[h]-insert_num);
*/
/* insert insert_num keys and node-pointers into L[h] */
bi.tb = tb;
bi.bi_bh = tb->L[h];
bi.bi_parent = tb->FL[h];
bi.bi_position = get_left_neighbor_position(tb, h);
internal_insert_childs(&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.tb = tb;
bi.bi_bh = tb->L[h];
bi.bi_parent = tb->FL[h];
bi.bi_position = get_left_neighbor_position(tb, h);
internal_insert_childs(&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);
put_dc_size(dc,
MAX_CHILD_SIZE(insert_ptr[k]) -
B_FREE_SPACE(insert_ptr[k]));
put_dc_block_number(dc, insert_ptr[k]->b_blocknr);
do_balance_mark_internal_dirty(tb, tbSh, 0);
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 = B_NR_ITEMS(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(tb,h,tbSh,tb->CFR[h],tb->rkey[h],tb->R[h],
tb->rnum[h] - insert_num); */
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.tb = tb;
bi.bi_bh = tb->R[h];
bi.bi_parent = tb->FR[h];
bi.bi_position = get_right_neighbor_position(tb, h);
internal_insert_childs(&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.tb = tb;
bi.bi_bh = tb->R[h];
bi.bi_parent = tb->FR[h];
bi.bi_position = get_right_neighbor_position(tb, h);
internal_insert_childs(&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);
put_dc_size(dc,
MAX_CHILD_SIZE(insert_ptr
[insert_num - k - 1]) -
B_FREE_SPACE(insert_ptr
[insert_num - k - 1]));
put_dc_block_number(dc,
insert_ptr[insert_num - k -
1]->b_blocknr);
do_balance_mark_internal_dirty(tb, tb->R[h], 0);
insert_num -= (k + 1);
}
}
/** Fill new node that appears instead of S[h] **/
RFALSE(tb->blknum[h] > 2, "blknum can not be > 2 for internal level");
RFALSE(tb->blknum[h] < 0, "blknum can not be < 0");
if (!tb->blknum[h]) { /* node S[h] is empty now */
RFALSE(!tbSh, "S[h] is equal NULL");
/* do what is needed for buffer thrown from tree */
reiserfs_invalidate_buffer(tb, tbSh);
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 block_head *blkh;
if (tb->blknum[h] != 1)
reiserfs_panic(NULL,
"balance_internal: One new node required for creating the new root");
/* S[h] = empty buffer from the list FEB. */
tbSh = get_FEB(tb);
blkh = B_BLK_HEAD(tbSh);
set_blkh_level(blkh, h + 1);
/* Put the unique node-pointer to S[h] that points to S[h-1]. */
dc = B_N_CHILD(tbSh, 0);
put_dc_block_number(dc, tbSh_1->b_blocknr);
put_dc_size(dc,
(MAX_CHILD_SIZE(tbSh_1) - B_FREE_SPACE(tbSh_1)));
tb->insert_size[h] -= DC_SIZE;
set_blkh_free_space(blkh, blkh_free_space(blkh) - DC_SIZE);
do_balance_mark_internal_dirty(tb, tbSh, 0);
/*&&&&&&&&&&&&&&&&&&&&&&&& */
check_internal(tbSh);
/*&&&&&&&&&&&&&&&&&&&&&&&& */
/* put new root into path structure */
PATH_OFFSET_PBUFFER(tb->tb_path, ILLEGAL_PATH_ELEMENT_OFFSET) =
tbSh;
/* Change root in structure super block. */
PUT_SB_ROOT_BLOCK(tb->tb_sb, tbSh->b_blocknr);
PUT_SB_TREE_HEIGHT(tb->tb_sb, SB_TREE_HEIGHT(tb->tb_sb) + 1);
do_balance_mark_sb_dirty(tb, REISERFS_SB(tb->tb_sb)->s_sbh, 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.tb = tb;
dest_bi.bi_bh = S_new;
dest_bi.bi_parent = NULL;
dest_bi.bi_position = 0;
src_bi.tb = tb;
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 = B_NR_ITEMS(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),