ibalance.c

linux 内核源代码

	       "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;
}