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kernel_linux/fs/reiserfs/ibalance.c
Linus Torvalds 1da177e4c3 Linux-2.6.12-rc2 
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00

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/*
* Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
*/
#include <linux/config.h>
#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),
KEY_SIZE);
/* last parameter is del_par */
internal_move_pointers_items (&dest_bi, &src_bi, LAST_TO_FIRST, snum, 0);
/* internal_move_pointers_items(S_new, tbSh, 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 (&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 (&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 (&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 (&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);
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, S_new,0);
insert_num -= (k + 1);
}
/* new_insert_ptr = node_pointer to S_new */
new_insert_ptr = S_new;
RFALSE (!buffer_journaled(S_new) || buffer_journal_dirty(S_new) ||
buffer_dirty (S_new),
"cm-00001: bad S_new (%b)", S_new);
// S_new is released in unfix_nodes
}
n = B_NR_ITEMS (tbSh); /*number of items in S[h] */
if ( 0 <= child_pos && child_pos <= n && insert_num > 0 ) {
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_insert_childs (
&bi,/*tbSh,*/
/* ( tb->S[h-1]->b_parent == tb->S[h] ) ? tb->S[h-1]->b_next : tb->S[h]->b_child->b_next,*/
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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