| /* |
| * Copyright 1996-2004 by Hans Reiser, licensing governed by |
| * reiserfsprogs/README |
| */ |
| |
| #include "includes.h" |
| |
| /* 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 */ |
| buffer_info_init_tbSh(tb, src_bi, h); |
| buffer_info_init_left(tb, dest_bi, h); |
| *d_key = tb->lkey[h]; |
| *cf = tb->CFL[h]; |
| break; |
| case INTERNAL_SHIFT_FROM_L_TO_S: |
| buffer_info_init_left(tb, src_bi, h); |
| buffer_info_init_tbSh(tb, dest_bi, h); |
| *d_key = tb->lkey[h]; |
| *cf = tb->CFL[h]; |
| break; |
| |
| case INTERNAL_SHIFT_FROM_R_TO_S: /* used in internal_shift_left */ |
| buffer_info_init_right(tb, src_bi, h); |
| buffer_info_init_tbSh(tb, dest_bi, h); |
| *d_key = tb->rkey[h]; |
| *cf = tb->CFR[h]; |
| break; |
| case INTERNAL_SHIFT_FROM_S_TO_R: |
| buffer_info_init_tbSh(tb, src_bi, h); |
| buffer_info_init_right(tb, dest_bi, h); |
| *d_key = tb->rkey[h]; |
| *cf = tb->CFR[h]; |
| break; |
| |
| case INTERNAL_INSERT_TO_L: |
| buffer_info_init_left(tb, dest_bi, h); |
| break; |
| |
| case INTERNAL_INSERT_TO_S: |
| buffer_info_init_tbSh(tb, dest_bi, h); |
| break; |
| |
| case INTERNAL_INSERT_TO_R: |
| buffer_info_init_right(tb, dest_bi, 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(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 *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(new_dc + i, MAX_CHILD_SIZE(bh[i]->b_size) - |
| get_blkh_free_space(B_BLK_HEAD(bh[i])), |
| bh[i]->b_blocknr); |
| /* |
| 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 = internal_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(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; |
| |
| 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 = internal_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(struct buffer_info *cur_bi, int from, int n) |
| { |
| int i_from = 0; |
| |
| if (from) |
| i_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); |
| |
| 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 = internal_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, internal_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(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; |
| |
| blkh = B_BLK_HEAD(dest); |
| nr = get_blkh_nr_items(blkh); |
| |
| /* prepare space for inserting key */ |
| key = internal_key(dest, dest_position_before); |
| memmove(key + 1, key, |
| (nr - dest_position_before) * KEY_SIZE + (nr + 1) * DC_SIZE); |
| |
| /* insert key */ |
| memcpy(key, internal_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(&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(&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); |
| |
| /* last parameter is del_parameter */ |
| internal_move_pointers_items(&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(&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(&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); |
| |
| /* last parameter is del_parameter */ |
| internal_move_pointers_items(&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) */ |
| buffer_info_init_tbSh(tb, &bi, h); |
| internal_delete_childs(&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); |
| 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); /* 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); |
| 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); |
| |
| 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(internal_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(internal_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] */ |
| buffer_info_init_left(tb, &bi, h); |
| internal_insert_childs(&bi, 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; |
| |
| buffer_info_init_left(tb, &bi, h); |
| internal_insert_childs(&bi, 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(dc, MAX_CHILD_SIZE(insert_ptr[k]->b_size) - |
| get_blkh_free_space(B_BLK_HEAD(insert_ptr[k])), |
| insert_ptr[k]->b_blocknr); |
| /* |
| 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] */ |
| buffer_info_init_right(tb, &bi, h); |
| internal_insert_childs(&bi, |
| 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; |
| |
| buffer_info_init_right(tb, &bi, h); |
| internal_insert_childs(&bi, 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(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])), |
| insert_ptr[insert_num - k - 1]->b_blocknr); |
| /* |
| 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); /* 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(dc, MAX_CHILD_SIZE(tbSh_1->b_size) - |
| get_blkh_free_space(B_BLK_HEAD(tbSh_1)), |
| tbSh_1->b_blocknr); |
| /* |
| 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); |
| |
| buffer_info_init_bh(tb, &dest_bi, S_new); |
| buffer_info_init_tbSh(tb, &src_bi, h); |
| |
| 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, internal_key(tbSh, n - snum), |
| KEY_SIZE); |
| /* last parameter is del_par */ |
| internal_move_pointers_items(&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, |
| internal_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, |
| 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, 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(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])), |
| insert_ptr[insert_num - k - 1]->b_blocknr); |
| /* |
| 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) { |
| buffer_info_init_tbSh(tb, &bi, h); |
| 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(&bi, child_pos, insert_num, |
| item_head(PATH_PLAST_BUFFER |
| (tb->tb_path), 0), |
| insert_ptr); |
| } else |
| internal_insert_childs(&bi, child_pos, insert_num, |
| insert_key, insert_ptr); |
| } |
| |
| insert_ptr[0] = new_insert_ptr; |
| if (new_insert_ptr) |
| memcpy(new_insert_key_addr, &new_insert_key, KEY_SIZE); |
| |
| return order; |
| } |