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