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![Jeff Mahoney](/assets/img/avatar_default.png)
This patch pushes the rest of the state variables in balance_leaf into the tree_balance structure so we can use them when we split balance_leaf into separate functions. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Jan Kara <jack@suse.cz>
2825 lines
77 KiB
C
2825 lines
77 KiB
C
/*
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* Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
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*/
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#include <linux/time.h>
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#include <linux/slab.h>
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#include <linux/string.h>
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#include "reiserfs.h"
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#include <linux/buffer_head.h>
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/*
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* To make any changes in the tree we find a node that contains item
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* to be changed/deleted or position in the node we insert a new item
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* to. We call this node S. To do balancing we need to decide what we
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* will shift to left/right neighbor, or to a new node, where new item
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* will be etc. To make this analysis simpler we build virtual
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* node. Virtual node is an array of items, that will replace items of
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* node S. (For instance if we are going to delete an item, virtual
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* node does not contain it). Virtual node keeps information about
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* item sizes and types, mergeability of first and last items, sizes
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* of all entries in directory item. We use this array of items when
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* calculating what we can shift to neighbors and how many nodes we
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* have to have if we do not any shiftings, if we shift to left/right
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* neighbor or to both.
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*/
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/*
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* Takes item number in virtual node, returns number of item
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* that it has in source buffer
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*/
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static inline int old_item_num(int new_num, int affected_item_num, int mode)
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{
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if (mode == M_PASTE || mode == M_CUT || new_num < affected_item_num)
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return new_num;
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if (mode == M_INSERT) {
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RFALSE(new_num == 0,
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"vs-8005: for INSERT mode and item number of inserted item");
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return new_num - 1;
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}
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RFALSE(mode != M_DELETE,
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"vs-8010: old_item_num: mode must be M_DELETE (mode = \'%c\'",
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mode);
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/* delete mode */
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return new_num + 1;
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}
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static void create_virtual_node(struct tree_balance *tb, int h)
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{
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struct item_head *ih;
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struct virtual_node *vn = tb->tb_vn;
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int new_num;
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struct buffer_head *Sh; /* this comes from tb->S[h] */
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Sh = PATH_H_PBUFFER(tb->tb_path, h);
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/* size of changed node */
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vn->vn_size =
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MAX_CHILD_SIZE(Sh) - B_FREE_SPACE(Sh) + tb->insert_size[h];
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/* for internal nodes array if virtual items is not created */
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if (h) {
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vn->vn_nr_item = (vn->vn_size - DC_SIZE) / (DC_SIZE + KEY_SIZE);
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return;
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}
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/* number of items in virtual node */
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vn->vn_nr_item =
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B_NR_ITEMS(Sh) + ((vn->vn_mode == M_INSERT) ? 1 : 0) -
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((vn->vn_mode == M_DELETE) ? 1 : 0);
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/* first virtual item */
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vn->vn_vi = (struct virtual_item *)(tb->tb_vn + 1);
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memset(vn->vn_vi, 0, vn->vn_nr_item * sizeof(struct virtual_item));
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vn->vn_free_ptr += vn->vn_nr_item * sizeof(struct virtual_item);
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/* first item in the node */
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ih = item_head(Sh, 0);
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/* define the mergeability for 0-th item (if it is not being deleted) */
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if (op_is_left_mergeable(&ih->ih_key, Sh->b_size)
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&& (vn->vn_mode != M_DELETE || vn->vn_affected_item_num))
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vn->vn_vi[0].vi_type |= VI_TYPE_LEFT_MERGEABLE;
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/*
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* go through all items that remain in the virtual
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* node (except for the new (inserted) one)
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*/
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for (new_num = 0; new_num < vn->vn_nr_item; new_num++) {
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int j;
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struct virtual_item *vi = vn->vn_vi + new_num;
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int is_affected =
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((new_num != vn->vn_affected_item_num) ? 0 : 1);
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if (is_affected && vn->vn_mode == M_INSERT)
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continue;
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/* get item number in source node */
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j = old_item_num(new_num, vn->vn_affected_item_num,
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vn->vn_mode);
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vi->vi_item_len += ih_item_len(ih + j) + IH_SIZE;
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vi->vi_ih = ih + j;
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vi->vi_item = ih_item_body(Sh, ih + j);
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vi->vi_uarea = vn->vn_free_ptr;
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/*
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* FIXME: there is no check that item operation did not
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* consume too much memory
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*/
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vn->vn_free_ptr +=
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op_create_vi(vn, vi, is_affected, tb->insert_size[0]);
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if (tb->vn_buf + tb->vn_buf_size < vn->vn_free_ptr)
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reiserfs_panic(tb->tb_sb, "vs-8030",
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"virtual node space consumed");
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if (!is_affected)
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/* this is not being changed */
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continue;
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if (vn->vn_mode == M_PASTE || vn->vn_mode == M_CUT) {
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vn->vn_vi[new_num].vi_item_len += tb->insert_size[0];
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/* pointer to data which is going to be pasted */
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vi->vi_new_data = vn->vn_data;
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}
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}
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/* virtual inserted item is not defined yet */
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if (vn->vn_mode == M_INSERT) {
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struct virtual_item *vi = vn->vn_vi + vn->vn_affected_item_num;
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RFALSE(vn->vn_ins_ih == NULL,
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"vs-8040: item header of inserted item is not specified");
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vi->vi_item_len = tb->insert_size[0];
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vi->vi_ih = vn->vn_ins_ih;
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vi->vi_item = vn->vn_data;
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vi->vi_uarea = vn->vn_free_ptr;
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op_create_vi(vn, vi, 0 /*not pasted or cut */ ,
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tb->insert_size[0]);
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}
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/*
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* set right merge flag we take right delimiting key and
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* check whether it is a mergeable item
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*/
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if (tb->CFR[0]) {
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struct reiserfs_key *key;
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key = internal_key(tb->CFR[0], tb->rkey[0]);
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if (op_is_left_mergeable(key, Sh->b_size)
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&& (vn->vn_mode != M_DELETE
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|| vn->vn_affected_item_num != B_NR_ITEMS(Sh) - 1))
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vn->vn_vi[vn->vn_nr_item - 1].vi_type |=
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VI_TYPE_RIGHT_MERGEABLE;
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#ifdef CONFIG_REISERFS_CHECK
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if (op_is_left_mergeable(key, Sh->b_size) &&
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!(vn->vn_mode != M_DELETE
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|| vn->vn_affected_item_num != B_NR_ITEMS(Sh) - 1)) {
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/*
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* we delete last item and it could be merged
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* with right neighbor's first item
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*/
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if (!
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(B_NR_ITEMS(Sh) == 1
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&& is_direntry_le_ih(item_head(Sh, 0))
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&& ih_entry_count(item_head(Sh, 0)) == 1)) {
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/*
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* node contains more than 1 item, or item
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* is not directory item, or this item
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* contains more than 1 entry
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*/
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print_block(Sh, 0, -1, -1);
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reiserfs_panic(tb->tb_sb, "vs-8045",
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"rdkey %k, affected item==%d "
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"(mode==%c) Must be %c",
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key, vn->vn_affected_item_num,
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vn->vn_mode, M_DELETE);
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}
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}
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#endif
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}
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}
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/*
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* Using virtual node check, how many items can be
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* shifted to left neighbor
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*/
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static void check_left(struct tree_balance *tb, int h, int cur_free)
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{
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int i;
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struct virtual_node *vn = tb->tb_vn;
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struct virtual_item *vi;
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int d_size, ih_size;
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RFALSE(cur_free < 0, "vs-8050: cur_free (%d) < 0", cur_free);
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/* internal level */
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if (h > 0) {
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tb->lnum[h] = cur_free / (DC_SIZE + KEY_SIZE);
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return;
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}
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/* leaf level */
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if (!cur_free || !vn->vn_nr_item) {
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/* no free space or nothing to move */
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tb->lnum[h] = 0;
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tb->lbytes = -1;
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return;
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}
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RFALSE(!PATH_H_PPARENT(tb->tb_path, 0),
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"vs-8055: parent does not exist or invalid");
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vi = vn->vn_vi;
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if ((unsigned int)cur_free >=
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(vn->vn_size -
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((vi->vi_type & VI_TYPE_LEFT_MERGEABLE) ? IH_SIZE : 0))) {
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/* all contents of S[0] fits into L[0] */
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RFALSE(vn->vn_mode == M_INSERT || vn->vn_mode == M_PASTE,
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"vs-8055: invalid mode or balance condition failed");
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tb->lnum[0] = vn->vn_nr_item;
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tb->lbytes = -1;
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return;
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}
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d_size = 0, ih_size = IH_SIZE;
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/* first item may be merge with last item in left neighbor */
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if (vi->vi_type & VI_TYPE_LEFT_MERGEABLE)
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d_size = -((int)IH_SIZE), ih_size = 0;
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tb->lnum[0] = 0;
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for (i = 0; i < vn->vn_nr_item;
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i++, ih_size = IH_SIZE, d_size = 0, vi++) {
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d_size += vi->vi_item_len;
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if (cur_free >= d_size) {
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/* the item can be shifted entirely */
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cur_free -= d_size;
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tb->lnum[0]++;
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continue;
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}
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/* the item cannot be shifted entirely, try to split it */
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/*
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* check whether L[0] can hold ih and at least one byte
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* of the item body
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*/
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/* cannot shift even a part of the current item */
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if (cur_free <= ih_size) {
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tb->lbytes = -1;
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return;
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}
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cur_free -= ih_size;
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tb->lbytes = op_check_left(vi, cur_free, 0, 0);
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if (tb->lbytes != -1)
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/* count partially shifted item */
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tb->lnum[0]++;
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break;
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}
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return;
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}
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/*
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* Using virtual node check, how many items can be
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* shifted to right neighbor
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*/
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static void check_right(struct tree_balance *tb, int h, int cur_free)
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{
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int i;
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struct virtual_node *vn = tb->tb_vn;
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struct virtual_item *vi;
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int d_size, ih_size;
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RFALSE(cur_free < 0, "vs-8070: cur_free < 0");
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/* internal level */
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if (h > 0) {
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tb->rnum[h] = cur_free / (DC_SIZE + KEY_SIZE);
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return;
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}
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/* leaf level */
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if (!cur_free || !vn->vn_nr_item) {
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/* no free space */
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tb->rnum[h] = 0;
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tb->rbytes = -1;
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return;
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}
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RFALSE(!PATH_H_PPARENT(tb->tb_path, 0),
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"vs-8075: parent does not exist or invalid");
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vi = vn->vn_vi + vn->vn_nr_item - 1;
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if ((unsigned int)cur_free >=
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(vn->vn_size -
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((vi->vi_type & VI_TYPE_RIGHT_MERGEABLE) ? IH_SIZE : 0))) {
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/* all contents of S[0] fits into R[0] */
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RFALSE(vn->vn_mode == M_INSERT || vn->vn_mode == M_PASTE,
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"vs-8080: invalid mode or balance condition failed");
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tb->rnum[h] = vn->vn_nr_item;
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tb->rbytes = -1;
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return;
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}
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d_size = 0, ih_size = IH_SIZE;
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/* last item may be merge with first item in right neighbor */
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if (vi->vi_type & VI_TYPE_RIGHT_MERGEABLE)
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d_size = -(int)IH_SIZE, ih_size = 0;
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tb->rnum[0] = 0;
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for (i = vn->vn_nr_item - 1; i >= 0;
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i--, d_size = 0, ih_size = IH_SIZE, vi--) {
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d_size += vi->vi_item_len;
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if (cur_free >= d_size) {
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/* the item can be shifted entirely */
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cur_free -= d_size;
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tb->rnum[0]++;
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continue;
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}
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/*
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* check whether R[0] can hold ih and at least one
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* byte of the item body
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*/
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/* cannot shift even a part of the current item */
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if (cur_free <= ih_size) {
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tb->rbytes = -1;
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return;
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}
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/*
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* R[0] can hold the header of the item and at least
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* one byte of its body
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*/
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cur_free -= ih_size; /* cur_free is still > 0 */
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tb->rbytes = op_check_right(vi, cur_free);
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if (tb->rbytes != -1)
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/* count partially shifted item */
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tb->rnum[0]++;
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break;
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}
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return;
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}
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/*
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* from - number of items, which are shifted to left neighbor entirely
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* to - number of item, which are shifted to right neighbor entirely
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* from_bytes - number of bytes of boundary item (or directory entries)
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* which are shifted to left neighbor
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* to_bytes - number of bytes of boundary item (or directory entries)
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* which are shifted to right neighbor
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*/
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static int get_num_ver(int mode, struct tree_balance *tb, int h,
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int from, int from_bytes,
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int to, int to_bytes, short *snum012, int flow)
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{
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int i;
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int cur_free;
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int units;
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struct virtual_node *vn = tb->tb_vn;
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int total_node_size, max_node_size, current_item_size;
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int needed_nodes;
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/* position of item we start filling node from */
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int start_item;
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/* position of item we finish filling node by */
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int end_item;
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/*
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* number of first bytes (entries for directory) of start_item-th item
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* we do not include into node that is being filled
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*/
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int start_bytes;
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/*
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* number of last bytes (entries for directory) of end_item-th item
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* we do node include into node that is being filled
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*/
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int end_bytes;
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/*
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* these are positions in virtual item of items, that are split
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* between S[0] and S1new and S1new and S2new
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*/
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int split_item_positions[2];
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split_item_positions[0] = -1;
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split_item_positions[1] = -1;
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/*
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* We only create additional nodes if we are in insert or paste mode
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* or we are in replace mode at the internal level. If h is 0 and
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* the mode is M_REPLACE then in fix_nodes we change the mode to
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* paste or insert before we get here in the code.
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*/
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RFALSE(tb->insert_size[h] < 0 || (mode != M_INSERT && mode != M_PASTE),
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"vs-8100: insert_size < 0 in overflow");
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max_node_size = MAX_CHILD_SIZE(PATH_H_PBUFFER(tb->tb_path, h));
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/*
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* snum012 [0-2] - number of items, that lay
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* to S[0], first new node and second new node
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*/
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snum012[3] = -1; /* s1bytes */
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snum012[4] = -1; /* s2bytes */
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/* internal level */
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if (h > 0) {
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i = ((to - from) * (KEY_SIZE + DC_SIZE) + DC_SIZE);
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if (i == max_node_size)
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return 1;
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return (i / max_node_size + 1);
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}
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/* leaf level */
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needed_nodes = 1;
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total_node_size = 0;
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cur_free = max_node_size;
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/* start from 'from'-th item */
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start_item = from;
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/* skip its first 'start_bytes' units */
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start_bytes = ((from_bytes != -1) ? from_bytes : 0);
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/* last included item is the 'end_item'-th one */
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end_item = vn->vn_nr_item - to - 1;
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/* do not count last 'end_bytes' units of 'end_item'-th item */
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end_bytes = (to_bytes != -1) ? to_bytes : 0;
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/*
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* go through all item beginning from the start_item-th item
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* and ending by the end_item-th item. Do not count first
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* 'start_bytes' units of 'start_item'-th item and last
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* 'end_bytes' of 'end_item'-th item
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*/
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for (i = start_item; i <= end_item; i++) {
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struct virtual_item *vi = vn->vn_vi + i;
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int skip_from_end = ((i == end_item) ? end_bytes : 0);
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RFALSE(needed_nodes > 3, "vs-8105: too many nodes are needed");
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/* get size of current item */
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current_item_size = vi->vi_item_len;
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/*
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* do not take in calculation head part (from_bytes)
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* of from-th item
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*/
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current_item_size -=
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op_part_size(vi, 0 /*from start */ , start_bytes);
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/* do not take in calculation tail part of last item */
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current_item_size -=
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op_part_size(vi, 1 /*from end */ , skip_from_end);
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/* if item fits into current node entierly */
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if (total_node_size + current_item_size <= max_node_size) {
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snum012[needed_nodes - 1]++;
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total_node_size += current_item_size;
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start_bytes = 0;
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continue;
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}
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/*
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* virtual item length is longer, than max size of item in
|
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* a node. It is impossible for direct item
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*/
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if (current_item_size > max_node_size) {
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RFALSE(is_direct_le_ih(vi->vi_ih),
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"vs-8110: "
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"direct item length is %d. It can not be longer than %d",
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|
current_item_size, max_node_size);
|
|
/* we will try to split it */
|
|
flow = 1;
|
|
}
|
|
|
|
/* as we do not split items, take new node and continue */
|
|
if (!flow) {
|
|
needed_nodes++;
|
|
i--;
|
|
total_node_size = 0;
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* calculate number of item units which fit into node being
|
|
* filled
|
|
*/
|
|
{
|
|
int free_space;
|
|
|
|
free_space = max_node_size - total_node_size - IH_SIZE;
|
|
units =
|
|
op_check_left(vi, free_space, start_bytes,
|
|
skip_from_end);
|
|
/*
|
|
* nothing fits into current node, take new
|
|
* node and continue
|
|
*/
|
|
if (units == -1) {
|
|
needed_nodes++, i--, total_node_size = 0;
|
|
continue;
|
|
}
|
|
}
|
|
|
|
/* something fits into the current node */
|
|
start_bytes += units;
|
|
snum012[needed_nodes - 1 + 3] = units;
|
|
|
|
if (needed_nodes > 2)
|
|
reiserfs_warning(tb->tb_sb, "vs-8111",
|
|
"split_item_position is out of range");
|
|
snum012[needed_nodes - 1]++;
|
|
split_item_positions[needed_nodes - 1] = i;
|
|
needed_nodes++;
|
|
/* continue from the same item with start_bytes != -1 */
|
|
start_item = i;
|
|
i--;
|
|
total_node_size = 0;
|
|
}
|
|
|
|
/*
|
|
* sum012[4] (if it is not -1) contains number of units of which
|
|
* are to be in S1new, snum012[3] - to be in S0. They are supposed
|
|
* to be S1bytes and S2bytes correspondingly, so recalculate
|
|
*/
|
|
if (snum012[4] > 0) {
|
|
int split_item_num;
|
|
int bytes_to_r, bytes_to_l;
|
|
int bytes_to_S1new;
|
|
|
|
split_item_num = split_item_positions[1];
|
|
bytes_to_l =
|
|
((from == split_item_num
|
|
&& from_bytes != -1) ? from_bytes : 0);
|
|
bytes_to_r =
|
|
((end_item == split_item_num
|
|
&& end_bytes != -1) ? end_bytes : 0);
|
|
bytes_to_S1new =
|
|
((split_item_positions[0] ==
|
|
split_item_positions[1]) ? snum012[3] : 0);
|
|
|
|
/* s2bytes */
|
|
snum012[4] =
|
|
op_unit_num(&vn->vn_vi[split_item_num]) - snum012[4] -
|
|
bytes_to_r - bytes_to_l - bytes_to_S1new;
|
|
|
|
if (vn->vn_vi[split_item_num].vi_index != TYPE_DIRENTRY &&
|
|
vn->vn_vi[split_item_num].vi_index != TYPE_INDIRECT)
|
|
reiserfs_warning(tb->tb_sb, "vs-8115",
|
|
"not directory or indirect item");
|
|
}
|
|
|
|
/* now we know S2bytes, calculate S1bytes */
|
|
if (snum012[3] > 0) {
|
|
int split_item_num;
|
|
int bytes_to_r, bytes_to_l;
|
|
int bytes_to_S2new;
|
|
|
|
split_item_num = split_item_positions[0];
|
|
bytes_to_l =
|
|
((from == split_item_num
|
|
&& from_bytes != -1) ? from_bytes : 0);
|
|
bytes_to_r =
|
|
((end_item == split_item_num
|
|
&& end_bytes != -1) ? end_bytes : 0);
|
|
bytes_to_S2new =
|
|
((split_item_positions[0] == split_item_positions[1]
|
|
&& snum012[4] != -1) ? snum012[4] : 0);
|
|
|
|
/* s1bytes */
|
|
snum012[3] =
|
|
op_unit_num(&vn->vn_vi[split_item_num]) - snum012[3] -
|
|
bytes_to_r - bytes_to_l - bytes_to_S2new;
|
|
}
|
|
|
|
return needed_nodes;
|
|
}
|
|
|
|
|
|
/*
|
|
* Set parameters for balancing.
|
|
* Performs write of results of analysis of balancing into structure tb,
|
|
* where it will later be used by the functions that actually do the balancing.
|
|
* Parameters:
|
|
* tb tree_balance structure;
|
|
* h current level of the node;
|
|
* lnum number of items from S[h] that must be shifted to L[h];
|
|
* rnum number of items from S[h] that must be shifted to R[h];
|
|
* blk_num number of blocks that S[h] will be splitted into;
|
|
* s012 number of items that fall into splitted nodes.
|
|
* lbytes number of bytes which flow to the left neighbor from the
|
|
* item that is not not shifted entirely
|
|
* rbytes number of bytes which flow to the right neighbor from the
|
|
* item that is not not shifted entirely
|
|
* s1bytes number of bytes which flow to the first new node when
|
|
* S[0] splits (this number is contained in s012 array)
|
|
*/
|
|
|
|
static void set_parameters(struct tree_balance *tb, int h, int lnum,
|
|
int rnum, int blk_num, short *s012, int lb, int rb)
|
|
{
|
|
|
|
tb->lnum[h] = lnum;
|
|
tb->rnum[h] = rnum;
|
|
tb->blknum[h] = blk_num;
|
|
|
|
/* only for leaf level */
|
|
if (h == 0) {
|
|
if (s012 != NULL) {
|
|
tb->s0num = *s012++;
|
|
tb->snum[0] = *s012++;
|
|
tb->snum[1] = *s012++;
|
|
tb->sbytes[0] = *s012++;
|
|
tb->sbytes[1] = *s012;
|
|
}
|
|
tb->lbytes = lb;
|
|
tb->rbytes = rb;
|
|
}
|
|
PROC_INFO_ADD(tb->tb_sb, lnum[h], lnum);
|
|
PROC_INFO_ADD(tb->tb_sb, rnum[h], rnum);
|
|
|
|
PROC_INFO_ADD(tb->tb_sb, lbytes[h], lb);
|
|
PROC_INFO_ADD(tb->tb_sb, rbytes[h], rb);
|
|
}
|
|
|
|
/*
|
|
* check if node disappears if we shift tb->lnum[0] items to left
|
|
* neighbor and tb->rnum[0] to the right one.
|
|
*/
|
|
static int is_leaf_removable(struct tree_balance *tb)
|
|
{
|
|
struct virtual_node *vn = tb->tb_vn;
|
|
int to_left, to_right;
|
|
int size;
|
|
int remain_items;
|
|
|
|
/*
|
|
* number of items that will be shifted to left (right) neighbor
|
|
* entirely
|
|
*/
|
|
to_left = tb->lnum[0] - ((tb->lbytes != -1) ? 1 : 0);
|
|
to_right = tb->rnum[0] - ((tb->rbytes != -1) ? 1 : 0);
|
|
remain_items = vn->vn_nr_item;
|
|
|
|
/* how many items remain in S[0] after shiftings to neighbors */
|
|
remain_items -= (to_left + to_right);
|
|
|
|
/* all content of node can be shifted to neighbors */
|
|
if (remain_items < 1) {
|
|
set_parameters(tb, 0, to_left, vn->vn_nr_item - to_left, 0,
|
|
NULL, -1, -1);
|
|
return 1;
|
|
}
|
|
|
|
/* S[0] is not removable */
|
|
if (remain_items > 1 || tb->lbytes == -1 || tb->rbytes == -1)
|
|
return 0;
|
|
|
|
/* check whether we can divide 1 remaining item between neighbors */
|
|
|
|
/* get size of remaining item (in item units) */
|
|
size = op_unit_num(&vn->vn_vi[to_left]);
|
|
|
|
if (tb->lbytes + tb->rbytes >= size) {
|
|
set_parameters(tb, 0, to_left + 1, to_right + 1, 0, NULL,
|
|
tb->lbytes, -1);
|
|
return 1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* check whether L, S, R can be joined in one node */
|
|
static int are_leaves_removable(struct tree_balance *tb, int lfree, int rfree)
|
|
{
|
|
struct virtual_node *vn = tb->tb_vn;
|
|
int ih_size;
|
|
struct buffer_head *S0;
|
|
|
|
S0 = PATH_H_PBUFFER(tb->tb_path, 0);
|
|
|
|
ih_size = 0;
|
|
if (vn->vn_nr_item) {
|
|
if (vn->vn_vi[0].vi_type & VI_TYPE_LEFT_MERGEABLE)
|
|
ih_size += IH_SIZE;
|
|
|
|
if (vn->vn_vi[vn->vn_nr_item - 1].
|
|
vi_type & VI_TYPE_RIGHT_MERGEABLE)
|
|
ih_size += IH_SIZE;
|
|
} else {
|
|
/* there was only one item and it will be deleted */
|
|
struct item_head *ih;
|
|
|
|
RFALSE(B_NR_ITEMS(S0) != 1,
|
|
"vs-8125: item number must be 1: it is %d",
|
|
B_NR_ITEMS(S0));
|
|
|
|
ih = item_head(S0, 0);
|
|
if (tb->CFR[0]
|
|
&& !comp_short_le_keys(&ih->ih_key,
|
|
internal_key(tb->CFR[0],
|
|
tb->rkey[0])))
|
|
/*
|
|
* Directory must be in correct state here: that is
|
|
* somewhere at the left side should exist first
|
|
* directory item. But the item being deleted can
|
|
* not be that first one because its right neighbor
|
|
* is item of the same directory. (But first item
|
|
* always gets deleted in last turn). So, neighbors
|
|
* of deleted item can be merged, so we can save
|
|
* ih_size
|
|
*/
|
|
if (is_direntry_le_ih(ih)) {
|
|
ih_size = IH_SIZE;
|
|
|
|
/*
|
|
* we might check that left neighbor exists
|
|
* and is of the same directory
|
|
*/
|
|
RFALSE(le_ih_k_offset(ih) == DOT_OFFSET,
|
|
"vs-8130: first directory item can not be removed until directory is not empty");
|
|
}
|
|
|
|
}
|
|
|
|
if (MAX_CHILD_SIZE(S0) + vn->vn_size <= rfree + lfree + ih_size) {
|
|
set_parameters(tb, 0, -1, -1, -1, NULL, -1, -1);
|
|
PROC_INFO_INC(tb->tb_sb, leaves_removable);
|
|
return 1;
|
|
}
|
|
return 0;
|
|
|
|
}
|
|
|
|
/* when we do not split item, lnum and rnum are numbers of entire items */
|
|
#define SET_PAR_SHIFT_LEFT \
|
|
if (h)\
|
|
{\
|
|
int to_l;\
|
|
\
|
|
to_l = (MAX_NR_KEY(Sh)+1 - lpar + vn->vn_nr_item + 1) / 2 -\
|
|
(MAX_NR_KEY(Sh) + 1 - lpar);\
|
|
\
|
|
set_parameters (tb, h, to_l, 0, lnver, NULL, -1, -1);\
|
|
}\
|
|
else \
|
|
{\
|
|
if (lset==LEFT_SHIFT_FLOW)\
|
|
set_parameters (tb, h, lpar, 0, lnver, snum012+lset,\
|
|
tb->lbytes, -1);\
|
|
else\
|
|
set_parameters (tb, h, lpar - (tb->lbytes!=-1), 0, lnver, snum012+lset,\
|
|
-1, -1);\
|
|
}
|
|
|
|
#define SET_PAR_SHIFT_RIGHT \
|
|
if (h)\
|
|
{\
|
|
int to_r;\
|
|
\
|
|
to_r = (MAX_NR_KEY(Sh)+1 - rpar + vn->vn_nr_item + 1) / 2 - (MAX_NR_KEY(Sh) + 1 - rpar);\
|
|
\
|
|
set_parameters (tb, h, 0, to_r, rnver, NULL, -1, -1);\
|
|
}\
|
|
else \
|
|
{\
|
|
if (rset==RIGHT_SHIFT_FLOW)\
|
|
set_parameters (tb, h, 0, rpar, rnver, snum012+rset,\
|
|
-1, tb->rbytes);\
|
|
else\
|
|
set_parameters (tb, h, 0, rpar - (tb->rbytes!=-1), rnver, snum012+rset,\
|
|
-1, -1);\
|
|
}
|
|
|
|
static void free_buffers_in_tb(struct tree_balance *tb)
|
|
{
|
|
int i;
|
|
|
|
pathrelse(tb->tb_path);
|
|
|
|
for (i = 0; i < MAX_HEIGHT; i++) {
|
|
brelse(tb->L[i]);
|
|
brelse(tb->R[i]);
|
|
brelse(tb->FL[i]);
|
|
brelse(tb->FR[i]);
|
|
brelse(tb->CFL[i]);
|
|
brelse(tb->CFR[i]);
|
|
|
|
tb->L[i] = NULL;
|
|
tb->R[i] = NULL;
|
|
tb->FL[i] = NULL;
|
|
tb->FR[i] = NULL;
|
|
tb->CFL[i] = NULL;
|
|
tb->CFR[i] = NULL;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Get new buffers for storing new nodes that are created while balancing.
|
|
* Returns: SCHEDULE_OCCURRED - schedule occurred while the function worked;
|
|
* CARRY_ON - schedule didn't occur while the function worked;
|
|
* NO_DISK_SPACE - no disk space.
|
|
*/
|
|
/* The function is NOT SCHEDULE-SAFE! */
|
|
static int get_empty_nodes(struct tree_balance *tb, int h)
|
|
{
|
|
struct buffer_head *new_bh, *Sh = PATH_H_PBUFFER(tb->tb_path, h);
|
|
b_blocknr_t *blocknr, blocknrs[MAX_AMOUNT_NEEDED] = { 0, };
|
|
int counter, number_of_freeblk;
|
|
int amount_needed; /* number of needed empty blocks */
|
|
int retval = CARRY_ON;
|
|
struct super_block *sb = tb->tb_sb;
|
|
|
|
/*
|
|
* number_of_freeblk is the number of empty blocks which have been
|
|
* acquired for use by the balancing algorithm minus the number of
|
|
* empty blocks used in the previous levels of the analysis,
|
|
* number_of_freeblk = tb->cur_blknum can be non-zero if a schedule
|
|
* occurs after empty blocks are acquired, and the balancing analysis
|
|
* is then restarted, amount_needed is the number needed by this
|
|
* level (h) of the balancing analysis.
|
|
*
|
|
* Note that for systems with many processes writing, it would be
|
|
* more layout optimal to calculate the total number needed by all
|
|
* levels and then to run reiserfs_new_blocks to get all of them at
|
|
* once.
|
|
*/
|
|
|
|
/*
|
|
* Initiate number_of_freeblk to the amount acquired prior to the
|
|
* restart of the analysis or 0 if not restarted, then subtract the
|
|
* amount needed by all of the levels of the tree below h.
|
|
*/
|
|
/* blknum includes S[h], so we subtract 1 in this calculation */
|
|
for (counter = 0, number_of_freeblk = tb->cur_blknum;
|
|
counter < h; counter++)
|
|
number_of_freeblk -=
|
|
(tb->blknum[counter]) ? (tb->blknum[counter] -
|
|
1) : 0;
|
|
|
|
/* Allocate missing empty blocks. */
|
|
/* if Sh == 0 then we are getting a new root */
|
|
amount_needed = (Sh) ? (tb->blknum[h] - 1) : 1;
|
|
/*
|
|
* Amount_needed = the amount that we need more than the
|
|
* amount that we have.
|
|
*/
|
|
if (amount_needed > number_of_freeblk)
|
|
amount_needed -= number_of_freeblk;
|
|
else /* If we have enough already then there is nothing to do. */
|
|
return CARRY_ON;
|
|
|
|
/*
|
|
* No need to check quota - is not allocated for blocks used
|
|
* for formatted nodes
|
|
*/
|
|
if (reiserfs_new_form_blocknrs(tb, blocknrs,
|
|
amount_needed) == NO_DISK_SPACE)
|
|
return NO_DISK_SPACE;
|
|
|
|
/* for each blocknumber we just got, get a buffer and stick it on FEB */
|
|
for (blocknr = blocknrs, counter = 0;
|
|
counter < amount_needed; blocknr++, counter++) {
|
|
|
|
RFALSE(!*blocknr,
|
|
"PAP-8135: reiserfs_new_blocknrs failed when got new blocks");
|
|
|
|
new_bh = sb_getblk(sb, *blocknr);
|
|
RFALSE(buffer_dirty(new_bh) ||
|
|
buffer_journaled(new_bh) ||
|
|
buffer_journal_dirty(new_bh),
|
|
"PAP-8140: journaled or dirty buffer %b for the new block",
|
|
new_bh);
|
|
|
|
/* Put empty buffers into the array. */
|
|
RFALSE(tb->FEB[tb->cur_blknum],
|
|
"PAP-8141: busy slot for new buffer");
|
|
|
|
set_buffer_journal_new(new_bh);
|
|
tb->FEB[tb->cur_blknum++] = new_bh;
|
|
}
|
|
|
|
if (retval == CARRY_ON && FILESYSTEM_CHANGED_TB(tb))
|
|
retval = REPEAT_SEARCH;
|
|
|
|
return retval;
|
|
}
|
|
|
|
/*
|
|
* Get free space of the left neighbor, which is stored in the parent
|
|
* node of the left neighbor.
|
|
*/
|
|
static int get_lfree(struct tree_balance *tb, int h)
|
|
{
|
|
struct buffer_head *l, *f;
|
|
int order;
|
|
|
|
if ((f = PATH_H_PPARENT(tb->tb_path, h)) == NULL ||
|
|
(l = tb->FL[h]) == NULL)
|
|
return 0;
|
|
|
|
if (f == l)
|
|
order = PATH_H_B_ITEM_ORDER(tb->tb_path, h) - 1;
|
|
else {
|
|
order = B_NR_ITEMS(l);
|
|
f = l;
|
|
}
|
|
|
|
return (MAX_CHILD_SIZE(f) - dc_size(B_N_CHILD(f, order)));
|
|
}
|
|
|
|
/*
|
|
* Get free space of the right neighbor,
|
|
* which is stored in the parent node of the right neighbor.
|
|
*/
|
|
static int get_rfree(struct tree_balance *tb, int h)
|
|
{
|
|
struct buffer_head *r, *f;
|
|
int order;
|
|
|
|
if ((f = PATH_H_PPARENT(tb->tb_path, h)) == NULL ||
|
|
(r = tb->FR[h]) == NULL)
|
|
return 0;
|
|
|
|
if (f == r)
|
|
order = PATH_H_B_ITEM_ORDER(tb->tb_path, h) + 1;
|
|
else {
|
|
order = 0;
|
|
f = r;
|
|
}
|
|
|
|
return (MAX_CHILD_SIZE(f) - dc_size(B_N_CHILD(f, order)));
|
|
|
|
}
|
|
|
|
/* Check whether left neighbor is in memory. */
|
|
static int is_left_neighbor_in_cache(struct tree_balance *tb, int h)
|
|
{
|
|
struct buffer_head *father, *left;
|
|
struct super_block *sb = tb->tb_sb;
|
|
b_blocknr_t left_neighbor_blocknr;
|
|
int left_neighbor_position;
|
|
|
|
/* Father of the left neighbor does not exist. */
|
|
if (!tb->FL[h])
|
|
return 0;
|
|
|
|
/* Calculate father of the node to be balanced. */
|
|
father = PATH_H_PBUFFER(tb->tb_path, h + 1);
|
|
|
|
RFALSE(!father ||
|
|
!B_IS_IN_TREE(father) ||
|
|
!B_IS_IN_TREE(tb->FL[h]) ||
|
|
!buffer_uptodate(father) ||
|
|
!buffer_uptodate(tb->FL[h]),
|
|
"vs-8165: F[h] (%b) or FL[h] (%b) is invalid",
|
|
father, tb->FL[h]);
|
|
|
|
/*
|
|
* Get position of the pointer to the left neighbor
|
|
* into the left father.
|
|
*/
|
|
left_neighbor_position = (father == tb->FL[h]) ?
|
|
tb->lkey[h] : B_NR_ITEMS(tb->FL[h]);
|
|
/* Get left neighbor block number. */
|
|
left_neighbor_blocknr =
|
|
B_N_CHILD_NUM(tb->FL[h], left_neighbor_position);
|
|
/* Look for the left neighbor in the cache. */
|
|
if ((left = sb_find_get_block(sb, left_neighbor_blocknr))) {
|
|
|
|
RFALSE(buffer_uptodate(left) && !B_IS_IN_TREE(left),
|
|
"vs-8170: left neighbor (%b %z) is not in the tree",
|
|
left, left);
|
|
put_bh(left);
|
|
return 1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
#define LEFT_PARENTS 'l'
|
|
#define RIGHT_PARENTS 'r'
|
|
|
|
static void decrement_key(struct cpu_key *key)
|
|
{
|
|
/* call item specific function for this key */
|
|
item_ops[cpu_key_k_type(key)]->decrement_key(key);
|
|
}
|
|
|
|
/*
|
|
* Calculate far left/right parent of the left/right neighbor of the
|
|
* current node, that is calculate the left/right (FL[h]/FR[h]) neighbor
|
|
* of the parent F[h].
|
|
* Calculate left/right common parent of the current node and L[h]/R[h].
|
|
* Calculate left/right delimiting key position.
|
|
* Returns: PATH_INCORRECT - path in the tree is not correct
|
|
* SCHEDULE_OCCURRED - schedule occurred while the function worked
|
|
* CARRY_ON - schedule didn't occur while the function
|
|
* worked
|
|
*/
|
|
static int get_far_parent(struct tree_balance *tb,
|
|
int h,
|
|
struct buffer_head **pfather,
|
|
struct buffer_head **pcom_father, char c_lr_par)
|
|
{
|
|
struct buffer_head *parent;
|
|
INITIALIZE_PATH(s_path_to_neighbor_father);
|
|
struct treepath *path = tb->tb_path;
|
|
struct cpu_key s_lr_father_key;
|
|
int counter,
|
|
position = INT_MAX,
|
|
first_last_position = 0,
|
|
path_offset = PATH_H_PATH_OFFSET(path, h);
|
|
|
|
/*
|
|
* Starting from F[h] go upwards in the tree, and look for the common
|
|
* ancestor of F[h], and its neighbor l/r, that should be obtained.
|
|
*/
|
|
|
|
counter = path_offset;
|
|
|
|
RFALSE(counter < FIRST_PATH_ELEMENT_OFFSET,
|
|
"PAP-8180: invalid path length");
|
|
|
|
for (; counter > FIRST_PATH_ELEMENT_OFFSET; counter--) {
|
|
/*
|
|
* Check whether parent of the current buffer in the path
|
|
* is really parent in the tree.
|
|
*/
|
|
if (!B_IS_IN_TREE
|
|
(parent = PATH_OFFSET_PBUFFER(path, counter - 1)))
|
|
return REPEAT_SEARCH;
|
|
|
|
/* Check whether position in the parent is correct. */
|
|
if ((position =
|
|
PATH_OFFSET_POSITION(path,
|
|
counter - 1)) >
|
|
B_NR_ITEMS(parent))
|
|
return REPEAT_SEARCH;
|
|
|
|
/*
|
|
* Check whether parent at the path really points
|
|
* to the child.
|
|
*/
|
|
if (B_N_CHILD_NUM(parent, position) !=
|
|
PATH_OFFSET_PBUFFER(path, counter)->b_blocknr)
|
|
return REPEAT_SEARCH;
|
|
|
|
/*
|
|
* Return delimiting key if position in the parent is not
|
|
* equal to first/last one.
|
|
*/
|
|
if (c_lr_par == RIGHT_PARENTS)
|
|
first_last_position = B_NR_ITEMS(parent);
|
|
if (position != first_last_position) {
|
|
*pcom_father = parent;
|
|
get_bh(*pcom_father);
|
|
/*(*pcom_father = parent)->b_count++; */
|
|
break;
|
|
}
|
|
}
|
|
|
|
/* if we are in the root of the tree, then there is no common father */
|
|
if (counter == FIRST_PATH_ELEMENT_OFFSET) {
|
|
/*
|
|
* Check whether first buffer in the path is the
|
|
* root of the tree.
|
|
*/
|
|
if (PATH_OFFSET_PBUFFER
|
|
(tb->tb_path,
|
|
FIRST_PATH_ELEMENT_OFFSET)->b_blocknr ==
|
|
SB_ROOT_BLOCK(tb->tb_sb)) {
|
|
*pfather = *pcom_father = NULL;
|
|
return CARRY_ON;
|
|
}
|
|
return REPEAT_SEARCH;
|
|
}
|
|
|
|
RFALSE(B_LEVEL(*pcom_father) <= DISK_LEAF_NODE_LEVEL,
|
|
"PAP-8185: (%b %z) level too small",
|
|
*pcom_father, *pcom_father);
|
|
|
|
/* Check whether the common parent is locked. */
|
|
|
|
if (buffer_locked(*pcom_father)) {
|
|
|
|
/* Release the write lock while the buffer is busy */
|
|
int depth = reiserfs_write_unlock_nested(tb->tb_sb);
|
|
__wait_on_buffer(*pcom_father);
|
|
reiserfs_write_lock_nested(tb->tb_sb, depth);
|
|
if (FILESYSTEM_CHANGED_TB(tb)) {
|
|
brelse(*pcom_father);
|
|
return REPEAT_SEARCH;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* So, we got common parent of the current node and its
|
|
* left/right neighbor. Now we are getting the parent of the
|
|
* left/right neighbor.
|
|
*/
|
|
|
|
/* Form key to get parent of the left/right neighbor. */
|
|
le_key2cpu_key(&s_lr_father_key,
|
|
internal_key(*pcom_father,
|
|
(c_lr_par ==
|
|
LEFT_PARENTS) ? (tb->lkey[h - 1] =
|
|
position -
|
|
1) : (tb->rkey[h -
|
|
1] =
|
|
position)));
|
|
|
|
if (c_lr_par == LEFT_PARENTS)
|
|
decrement_key(&s_lr_father_key);
|
|
|
|
if (search_by_key
|
|
(tb->tb_sb, &s_lr_father_key, &s_path_to_neighbor_father,
|
|
h + 1) == IO_ERROR)
|
|
/* path is released */
|
|
return IO_ERROR;
|
|
|
|
if (FILESYSTEM_CHANGED_TB(tb)) {
|
|
pathrelse(&s_path_to_neighbor_father);
|
|
brelse(*pcom_father);
|
|
return REPEAT_SEARCH;
|
|
}
|
|
|
|
*pfather = PATH_PLAST_BUFFER(&s_path_to_neighbor_father);
|
|
|
|
RFALSE(B_LEVEL(*pfather) != h + 1,
|
|
"PAP-8190: (%b %z) level too small", *pfather, *pfather);
|
|
RFALSE(s_path_to_neighbor_father.path_length <
|
|
FIRST_PATH_ELEMENT_OFFSET, "PAP-8192: path length is too small");
|
|
|
|
s_path_to_neighbor_father.path_length--;
|
|
pathrelse(&s_path_to_neighbor_father);
|
|
return CARRY_ON;
|
|
}
|
|
|
|
/*
|
|
* Get parents of neighbors of node in the path(S[path_offset]) and
|
|
* common parents of S[path_offset] and L[path_offset]/R[path_offset]:
|
|
* F[path_offset], FL[path_offset], FR[path_offset], CFL[path_offset],
|
|
* CFR[path_offset].
|
|
* Calculate numbers of left and right delimiting keys position:
|
|
* lkey[path_offset], rkey[path_offset].
|
|
* Returns: SCHEDULE_OCCURRED - schedule occurred while the function worked
|
|
* CARRY_ON - schedule didn't occur while the function worked
|
|
*/
|
|
static int get_parents(struct tree_balance *tb, int h)
|
|
{
|
|
struct treepath *path = tb->tb_path;
|
|
int position,
|
|
ret,
|
|
path_offset = PATH_H_PATH_OFFSET(tb->tb_path, h);
|
|
struct buffer_head *curf, *curcf;
|
|
|
|
/* Current node is the root of the tree or will be root of the tree */
|
|
if (path_offset <= FIRST_PATH_ELEMENT_OFFSET) {
|
|
/*
|
|
* The root can not have parents.
|
|
* Release nodes which previously were obtained as
|
|
* parents of the current node neighbors.
|
|
*/
|
|
brelse(tb->FL[h]);
|
|
brelse(tb->CFL[h]);
|
|
brelse(tb->FR[h]);
|
|
brelse(tb->CFR[h]);
|
|
tb->FL[h] = NULL;
|
|
tb->CFL[h] = NULL;
|
|
tb->FR[h] = NULL;
|
|
tb->CFR[h] = NULL;
|
|
return CARRY_ON;
|
|
}
|
|
|
|
/* Get parent FL[path_offset] of L[path_offset]. */
|
|
position = PATH_OFFSET_POSITION(path, path_offset - 1);
|
|
if (position) {
|
|
/* Current node is not the first child of its parent. */
|
|
curf = PATH_OFFSET_PBUFFER(path, path_offset - 1);
|
|
curcf = PATH_OFFSET_PBUFFER(path, path_offset - 1);
|
|
get_bh(curf);
|
|
get_bh(curf);
|
|
tb->lkey[h] = position - 1;
|
|
} else {
|
|
/*
|
|
* Calculate current parent of L[path_offset], which is the
|
|
* left neighbor of the current node. Calculate current
|
|
* common parent of L[path_offset] and the current node.
|
|
* Note that CFL[path_offset] not equal FL[path_offset] and
|
|
* CFL[path_offset] not equal F[path_offset].
|
|
* Calculate lkey[path_offset].
|
|
*/
|
|
if ((ret = get_far_parent(tb, h + 1, &curf,
|
|
&curcf,
|
|
LEFT_PARENTS)) != CARRY_ON)
|
|
return ret;
|
|
}
|
|
|
|
brelse(tb->FL[h]);
|
|
tb->FL[h] = curf; /* New initialization of FL[h]. */
|
|
brelse(tb->CFL[h]);
|
|
tb->CFL[h] = curcf; /* New initialization of CFL[h]. */
|
|
|
|
RFALSE((curf && !B_IS_IN_TREE(curf)) ||
|
|
(curcf && !B_IS_IN_TREE(curcf)),
|
|
"PAP-8195: FL (%b) or CFL (%b) is invalid", curf, curcf);
|
|
|
|
/* Get parent FR[h] of R[h]. */
|
|
|
|
/* Current node is the last child of F[h]. FR[h] != F[h]. */
|
|
if (position == B_NR_ITEMS(PATH_H_PBUFFER(path, h + 1))) {
|
|
/*
|
|
* Calculate current parent of R[h], which is the right
|
|
* neighbor of F[h]. Calculate current common parent of
|
|
* R[h] and current node. Note that CFR[h] not equal
|
|
* FR[path_offset] and CFR[h] not equal F[h].
|
|
*/
|
|
if ((ret =
|
|
get_far_parent(tb, h + 1, &curf, &curcf,
|
|
RIGHT_PARENTS)) != CARRY_ON)
|
|
return ret;
|
|
} else {
|
|
/* Current node is not the last child of its parent F[h]. */
|
|
curf = PATH_OFFSET_PBUFFER(path, path_offset - 1);
|
|
curcf = PATH_OFFSET_PBUFFER(path, path_offset - 1);
|
|
get_bh(curf);
|
|
get_bh(curf);
|
|
tb->rkey[h] = position;
|
|
}
|
|
|
|
brelse(tb->FR[h]);
|
|
/* New initialization of FR[path_offset]. */
|
|
tb->FR[h] = curf;
|
|
|
|
brelse(tb->CFR[h]);
|
|
/* New initialization of CFR[path_offset]. */
|
|
tb->CFR[h] = curcf;
|
|
|
|
RFALSE((curf && !B_IS_IN_TREE(curf)) ||
|
|
(curcf && !B_IS_IN_TREE(curcf)),
|
|
"PAP-8205: FR (%b) or CFR (%b) is invalid", curf, curcf);
|
|
|
|
return CARRY_ON;
|
|
}
|
|
|
|
/*
|
|
* it is possible to remove node as result of shiftings to
|
|
* neighbors even when we insert or paste item.
|
|
*/
|
|
static inline int can_node_be_removed(int mode, int lfree, int sfree, int rfree,
|
|
struct tree_balance *tb, int h)
|
|
{
|
|
struct buffer_head *Sh = PATH_H_PBUFFER(tb->tb_path, h);
|
|
int levbytes = tb->insert_size[h];
|
|
struct item_head *ih;
|
|
struct reiserfs_key *r_key = NULL;
|
|
|
|
ih = item_head(Sh, 0);
|
|
if (tb->CFR[h])
|
|
r_key = internal_key(tb->CFR[h], tb->rkey[h]);
|
|
|
|
if (lfree + rfree + sfree < MAX_CHILD_SIZE(Sh) + levbytes
|
|
/* shifting may merge items which might save space */
|
|
-
|
|
((!h
|
|
&& op_is_left_mergeable(&ih->ih_key, Sh->b_size)) ? IH_SIZE : 0)
|
|
-
|
|
((!h && r_key
|
|
&& op_is_left_mergeable(r_key, Sh->b_size)) ? IH_SIZE : 0)
|
|
+ ((h) ? KEY_SIZE : 0)) {
|
|
/* node can not be removed */
|
|
if (sfree >= levbytes) {
|
|
/* new item fits into node S[h] without any shifting */
|
|
if (!h)
|
|
tb->s0num =
|
|
B_NR_ITEMS(Sh) +
|
|
((mode == M_INSERT) ? 1 : 0);
|
|
set_parameters(tb, h, 0, 0, 1, NULL, -1, -1);
|
|
return NO_BALANCING_NEEDED;
|
|
}
|
|
}
|
|
PROC_INFO_INC(tb->tb_sb, can_node_be_removed[h]);
|
|
return !NO_BALANCING_NEEDED;
|
|
}
|
|
|
|
/*
|
|
* Check whether current node S[h] is balanced when increasing its size by
|
|
* Inserting or Pasting.
|
|
* Calculate parameters for balancing for current level h.
|
|
* Parameters:
|
|
* tb tree_balance structure;
|
|
* h current level of the node;
|
|
* inum item number in S[h];
|
|
* mode i - insert, p - paste;
|
|
* Returns: 1 - schedule occurred;
|
|
* 0 - balancing for higher levels needed;
|
|
* -1 - no balancing for higher levels needed;
|
|
* -2 - no disk space.
|
|
*/
|
|
/* ip means Inserting or Pasting */
|
|
static int ip_check_balance(struct tree_balance *tb, int h)
|
|
{
|
|
struct virtual_node *vn = tb->tb_vn;
|
|
/*
|
|
* Number of bytes that must be inserted into (value is negative
|
|
* if bytes are deleted) buffer which contains node being balanced.
|
|
* The mnemonic is that the attempted change in node space used
|
|
* level is levbytes bytes.
|
|
*/
|
|
int levbytes;
|
|
int ret;
|
|
|
|
int lfree, sfree, rfree /* free space in L, S and R */ ;
|
|
|
|
/*
|
|
* nver is short for number of vertixes, and lnver is the number if
|
|
* we shift to the left, rnver is the number if we shift to the
|
|
* right, and lrnver is the number if we shift in both directions.
|
|
* The goal is to minimize first the number of vertixes, and second,
|
|
* the number of vertixes whose contents are changed by shifting,
|
|
* and third the number of uncached vertixes whose contents are
|
|
* changed by shifting and must be read from disk.
|
|
*/
|
|
int nver, lnver, rnver, lrnver;
|
|
|
|
/*
|
|
* used at leaf level only, S0 = S[0] is the node being balanced,
|
|
* sInum [ I = 0,1,2 ] is the number of items that will
|
|
* remain in node SI after balancing. S1 and S2 are new
|
|
* nodes that might be created.
|
|
*/
|
|
|
|
/*
|
|
* we perform 8 calls to get_num_ver(). For each call we
|
|
* calculate five parameters. where 4th parameter is s1bytes
|
|
* and 5th - s2bytes
|
|
*
|
|
* s0num, s1num, s2num for 8 cases
|
|
* 0,1 - do not shift and do not shift but bottle
|
|
* 2 - shift only whole item to left
|
|
* 3 - shift to left and bottle as much as possible
|
|
* 4,5 - shift to right (whole items and as much as possible
|
|
* 6,7 - shift to both directions (whole items and as much as possible)
|
|
*/
|
|
short snum012[40] = { 0, };
|
|
|
|
/* Sh is the node whose balance is currently being checked */
|
|
struct buffer_head *Sh;
|
|
|
|
Sh = PATH_H_PBUFFER(tb->tb_path, h);
|
|
levbytes = tb->insert_size[h];
|
|
|
|
/* Calculate balance parameters for creating new root. */
|
|
if (!Sh) {
|
|
if (!h)
|
|
reiserfs_panic(tb->tb_sb, "vs-8210",
|
|
"S[0] can not be 0");
|
|
switch (ret = get_empty_nodes(tb, h)) {
|
|
/* no balancing for higher levels needed */
|
|
case CARRY_ON:
|
|
set_parameters(tb, h, 0, 0, 1, NULL, -1, -1);
|
|
return NO_BALANCING_NEEDED;
|
|
|
|
case NO_DISK_SPACE:
|
|
case REPEAT_SEARCH:
|
|
return ret;
|
|
default:
|
|
reiserfs_panic(tb->tb_sb, "vs-8215", "incorrect "
|
|
"return value of get_empty_nodes");
|
|
}
|
|
}
|
|
|
|
/* get parents of S[h] neighbors. */
|
|
ret = get_parents(tb, h);
|
|
if (ret != CARRY_ON)
|
|
return ret;
|
|
|
|
sfree = B_FREE_SPACE(Sh);
|
|
|
|
/* get free space of neighbors */
|
|
rfree = get_rfree(tb, h);
|
|
lfree = get_lfree(tb, h);
|
|
|
|
/* and new item fits into node S[h] without any shifting */
|
|
if (can_node_be_removed(vn->vn_mode, lfree, sfree, rfree, tb, h) ==
|
|
NO_BALANCING_NEEDED)
|
|
return NO_BALANCING_NEEDED;
|
|
|
|
create_virtual_node(tb, h);
|
|
|
|
/*
|
|
* determine maximal number of items we can shift to the left
|
|
* neighbor (in tb structure) and the maximal number of bytes
|
|
* that can flow to the left neighbor from the left most liquid
|
|
* item that cannot be shifted from S[0] entirely (returned value)
|
|
*/
|
|
check_left(tb, h, lfree);
|
|
|
|
/*
|
|
* determine maximal number of items we can shift to the right
|
|
* neighbor (in tb structure) and the maximal number of bytes
|
|
* that can flow to the right neighbor from the right most liquid
|
|
* item that cannot be shifted from S[0] entirely (returned value)
|
|
*/
|
|
check_right(tb, h, rfree);
|
|
|
|
/*
|
|
* all contents of internal node S[h] can be moved into its
|
|
* neighbors, S[h] will be removed after balancing
|
|
*/
|
|
if (h && (tb->rnum[h] + tb->lnum[h] >= vn->vn_nr_item + 1)) {
|
|
int to_r;
|
|
|
|
/*
|
|
* Since we are working on internal nodes, and our internal
|
|
* nodes have fixed size entries, then we can balance by the
|
|
* number of items rather than the space they consume. In this
|
|
* routine we set the left node equal to the right node,
|
|
* allowing a difference of less than or equal to 1 child
|
|
* pointer.
|
|
*/
|
|
to_r =
|
|
((MAX_NR_KEY(Sh) << 1) + 2 - tb->lnum[h] - tb->rnum[h] +
|
|
vn->vn_nr_item + 1) / 2 - (MAX_NR_KEY(Sh) + 1 -
|
|
tb->rnum[h]);
|
|
set_parameters(tb, h, vn->vn_nr_item + 1 - to_r, to_r, 0, NULL,
|
|
-1, -1);
|
|
return CARRY_ON;
|
|
}
|
|
|
|
/*
|
|
* this checks balance condition, that any two neighboring nodes
|
|
* can not fit in one node
|
|
*/
|
|
RFALSE(h &&
|
|
(tb->lnum[h] >= vn->vn_nr_item + 1 ||
|
|
tb->rnum[h] >= vn->vn_nr_item + 1),
|
|
"vs-8220: tree is not balanced on internal level");
|
|
RFALSE(!h && ((tb->lnum[h] >= vn->vn_nr_item && (tb->lbytes == -1)) ||
|
|
(tb->rnum[h] >= vn->vn_nr_item && (tb->rbytes == -1))),
|
|
"vs-8225: tree is not balanced on leaf level");
|
|
|
|
/*
|
|
* all contents of S[0] can be moved into its neighbors
|
|
* S[0] will be removed after balancing.
|
|
*/
|
|
if (!h && is_leaf_removable(tb))
|
|
return CARRY_ON;
|
|
|
|
/*
|
|
* why do we perform this check here rather than earlier??
|
|
* Answer: we can win 1 node in some cases above. Moreover we
|
|
* checked it above, when we checked, that S[0] is not removable
|
|
* in principle
|
|
*/
|
|
|
|
/* new item fits into node S[h] without any shifting */
|
|
if (sfree >= levbytes) {
|
|
if (!h)
|
|
tb->s0num = vn->vn_nr_item;
|
|
set_parameters(tb, h, 0, 0, 1, NULL, -1, -1);
|
|
return NO_BALANCING_NEEDED;
|
|
}
|
|
|
|
{
|
|
int lpar, rpar, nset, lset, rset, lrset;
|
|
/* regular overflowing of the node */
|
|
|
|
/*
|
|
* get_num_ver works in 2 modes (FLOW & NO_FLOW)
|
|
* lpar, rpar - number of items we can shift to left/right
|
|
* neighbor (including splitting item)
|
|
* nset, lset, rset, lrset - shows, whether flowing items
|
|
* give better packing
|
|
*/
|
|
#define FLOW 1
|
|
#define NO_FLOW 0 /* do not any splitting */
|
|
|
|
/* we choose one of the following */
|
|
#define NOTHING_SHIFT_NO_FLOW 0
|
|
#define NOTHING_SHIFT_FLOW 5
|
|
#define LEFT_SHIFT_NO_FLOW 10
|
|
#define LEFT_SHIFT_FLOW 15
|
|
#define RIGHT_SHIFT_NO_FLOW 20
|
|
#define RIGHT_SHIFT_FLOW 25
|
|
#define LR_SHIFT_NO_FLOW 30
|
|
#define LR_SHIFT_FLOW 35
|
|
|
|
lpar = tb->lnum[h];
|
|
rpar = tb->rnum[h];
|
|
|
|
/*
|
|
* calculate number of blocks S[h] must be split into when
|
|
* nothing is shifted to the neighbors, as well as number of
|
|
* items in each part of the split node (s012 numbers),
|
|
* and number of bytes (s1bytes) of the shared drop which
|
|
* flow to S1 if any
|
|
*/
|
|
nset = NOTHING_SHIFT_NO_FLOW;
|
|
nver = get_num_ver(vn->vn_mode, tb, h,
|
|
0, -1, h ? vn->vn_nr_item : 0, -1,
|
|
snum012, NO_FLOW);
|
|
|
|
if (!h) {
|
|
int nver1;
|
|
|
|
/*
|
|
* note, that in this case we try to bottle
|
|
* between S[0] and S1 (S1 - the first new node)
|
|
*/
|
|
nver1 = get_num_ver(vn->vn_mode, tb, h,
|
|
0, -1, 0, -1,
|
|
snum012 + NOTHING_SHIFT_FLOW, FLOW);
|
|
if (nver > nver1)
|
|
nset = NOTHING_SHIFT_FLOW, nver = nver1;
|
|
}
|
|
|
|
/*
|
|
* calculate number of blocks S[h] must be split into when
|
|
* l_shift_num first items and l_shift_bytes of the right
|
|
* most liquid item to be shifted are shifted to the left
|
|
* neighbor, as well as number of items in each part of the
|
|
* splitted node (s012 numbers), and number of bytes
|
|
* (s1bytes) of the shared drop which flow to S1 if any
|
|
*/
|
|
lset = LEFT_SHIFT_NO_FLOW;
|
|
lnver = get_num_ver(vn->vn_mode, tb, h,
|
|
lpar - ((h || tb->lbytes == -1) ? 0 : 1),
|
|
-1, h ? vn->vn_nr_item : 0, -1,
|
|
snum012 + LEFT_SHIFT_NO_FLOW, NO_FLOW);
|
|
if (!h) {
|
|
int lnver1;
|
|
|
|
lnver1 = get_num_ver(vn->vn_mode, tb, h,
|
|
lpar -
|
|
((tb->lbytes != -1) ? 1 : 0),
|
|
tb->lbytes, 0, -1,
|
|
snum012 + LEFT_SHIFT_FLOW, FLOW);
|
|
if (lnver > lnver1)
|
|
lset = LEFT_SHIFT_FLOW, lnver = lnver1;
|
|
}
|
|
|
|
/*
|
|
* calculate number of blocks S[h] must be split into when
|
|
* r_shift_num first items and r_shift_bytes of the left most
|
|
* liquid item to be shifted are shifted to the right neighbor,
|
|
* as well as number of items in each part of the splitted
|
|
* node (s012 numbers), and number of bytes (s1bytes) of the
|
|
* shared drop which flow to S1 if any
|
|
*/
|
|
rset = RIGHT_SHIFT_NO_FLOW;
|
|
rnver = get_num_ver(vn->vn_mode, tb, h,
|
|
0, -1,
|
|
h ? (vn->vn_nr_item - rpar) : (rpar -
|
|
((tb->
|
|
rbytes !=
|
|
-1) ? 1 :
|
|
0)), -1,
|
|
snum012 + RIGHT_SHIFT_NO_FLOW, NO_FLOW);
|
|
if (!h) {
|
|
int rnver1;
|
|
|
|
rnver1 = get_num_ver(vn->vn_mode, tb, h,
|
|
0, -1,
|
|
(rpar -
|
|
((tb->rbytes != -1) ? 1 : 0)),
|
|
tb->rbytes,
|
|
snum012 + RIGHT_SHIFT_FLOW, FLOW);
|
|
|
|
if (rnver > rnver1)
|
|
rset = RIGHT_SHIFT_FLOW, rnver = rnver1;
|
|
}
|
|
|
|
/*
|
|
* calculate number of blocks S[h] must be split into when
|
|
* items are shifted in both directions, as well as number
|
|
* of items in each part of the splitted node (s012 numbers),
|
|
* and number of bytes (s1bytes) of the shared drop which
|
|
* flow to S1 if any
|
|
*/
|
|
lrset = LR_SHIFT_NO_FLOW;
|
|
lrnver = get_num_ver(vn->vn_mode, tb, h,
|
|
lpar - ((h || tb->lbytes == -1) ? 0 : 1),
|
|
-1,
|
|
h ? (vn->vn_nr_item - rpar) : (rpar -
|
|
((tb->
|
|
rbytes !=
|
|
-1) ? 1 :
|
|
0)), -1,
|
|
snum012 + LR_SHIFT_NO_FLOW, NO_FLOW);
|
|
if (!h) {
|
|
int lrnver1;
|
|
|
|
lrnver1 = get_num_ver(vn->vn_mode, tb, h,
|
|
lpar -
|
|
((tb->lbytes != -1) ? 1 : 0),
|
|
tb->lbytes,
|
|
(rpar -
|
|
((tb->rbytes != -1) ? 1 : 0)),
|
|
tb->rbytes,
|
|
snum012 + LR_SHIFT_FLOW, FLOW);
|
|
if (lrnver > lrnver1)
|
|
lrset = LR_SHIFT_FLOW, lrnver = lrnver1;
|
|
}
|
|
|
|
/*
|
|
* Our general shifting strategy is:
|
|
* 1) to minimized number of new nodes;
|
|
* 2) to minimized number of neighbors involved in shifting;
|
|
* 3) to minimized number of disk reads;
|
|
*/
|
|
|
|
/* we can win TWO or ONE nodes by shifting in both directions */
|
|
if (lrnver < lnver && lrnver < rnver) {
|
|
RFALSE(h &&
|
|
(tb->lnum[h] != 1 ||
|
|
tb->rnum[h] != 1 ||
|
|
lrnver != 1 || rnver != 2 || lnver != 2
|
|
|| h != 1), "vs-8230: bad h");
|
|
if (lrset == LR_SHIFT_FLOW)
|
|
set_parameters(tb, h, tb->lnum[h], tb->rnum[h],
|
|
lrnver, snum012 + lrset,
|
|
tb->lbytes, tb->rbytes);
|
|
else
|
|
set_parameters(tb, h,
|
|
tb->lnum[h] -
|
|
((tb->lbytes == -1) ? 0 : 1),
|
|
tb->rnum[h] -
|
|
((tb->rbytes == -1) ? 0 : 1),
|
|
lrnver, snum012 + lrset, -1, -1);
|
|
|
|
return CARRY_ON;
|
|
}
|
|
|
|
/*
|
|
* if shifting doesn't lead to better packing
|
|
* then don't shift
|
|
*/
|
|
if (nver == lrnver) {
|
|
set_parameters(tb, h, 0, 0, nver, snum012 + nset, -1,
|
|
-1);
|
|
return CARRY_ON;
|
|
}
|
|
|
|
/*
|
|
* now we know that for better packing shifting in only one
|
|
* direction either to the left or to the right is required
|
|
*/
|
|
|
|
/*
|
|
* if shifting to the left is better than
|
|
* shifting to the right
|
|
*/
|
|
if (lnver < rnver) {
|
|
SET_PAR_SHIFT_LEFT;
|
|
return CARRY_ON;
|
|
}
|
|
|
|
/*
|
|
* if shifting to the right is better than
|
|
* shifting to the left
|
|
*/
|
|
if (lnver > rnver) {
|
|
SET_PAR_SHIFT_RIGHT;
|
|
return CARRY_ON;
|
|
}
|
|
|
|
/*
|
|
* now shifting in either direction gives the same number
|
|
* of nodes and we can make use of the cached neighbors
|
|
*/
|
|
if (is_left_neighbor_in_cache(tb, h)) {
|
|
SET_PAR_SHIFT_LEFT;
|
|
return CARRY_ON;
|
|
}
|
|
|
|
/*
|
|
* shift to the right independently on whether the
|
|
* right neighbor in cache or not
|
|
*/
|
|
SET_PAR_SHIFT_RIGHT;
|
|
return CARRY_ON;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Check whether current node S[h] is balanced when Decreasing its size by
|
|
* Deleting or Cutting for INTERNAL node of S+tree.
|
|
* Calculate parameters for balancing for current level h.
|
|
* Parameters:
|
|
* tb tree_balance structure;
|
|
* h current level of the node;
|
|
* inum item number in S[h];
|
|
* mode i - insert, p - paste;
|
|
* Returns: 1 - schedule occurred;
|
|
* 0 - balancing for higher levels needed;
|
|
* -1 - no balancing for higher levels needed;
|
|
* -2 - no disk space.
|
|
*
|
|
* Note: Items of internal nodes have fixed size, so the balance condition for
|
|
* the internal part of S+tree is as for the B-trees.
|
|
*/
|
|
static int dc_check_balance_internal(struct tree_balance *tb, int h)
|
|
{
|
|
struct virtual_node *vn = tb->tb_vn;
|
|
|
|
/*
|
|
* Sh is the node whose balance is currently being checked,
|
|
* and Fh is its father.
|
|
*/
|
|
struct buffer_head *Sh, *Fh;
|
|
int maxsize, ret;
|
|
int lfree, rfree /* free space in L and R */ ;
|
|
|
|
Sh = PATH_H_PBUFFER(tb->tb_path, h);
|
|
Fh = PATH_H_PPARENT(tb->tb_path, h);
|
|
|
|
maxsize = MAX_CHILD_SIZE(Sh);
|
|
|
|
/*
|
|
* using tb->insert_size[h], which is negative in this case,
|
|
* create_virtual_node calculates:
|
|
* new_nr_item = number of items node would have if operation is
|
|
* performed without balancing (new_nr_item);
|
|
*/
|
|
create_virtual_node(tb, h);
|
|
|
|
if (!Fh) { /* S[h] is the root. */
|
|
/* no balancing for higher levels needed */
|
|
if (vn->vn_nr_item > 0) {
|
|
set_parameters(tb, h, 0, 0, 1, NULL, -1, -1);
|
|
return NO_BALANCING_NEEDED;
|
|
}
|
|
/*
|
|
* new_nr_item == 0.
|
|
* Current root will be deleted resulting in
|
|
* decrementing the tree height.
|
|
*/
|
|
set_parameters(tb, h, 0, 0, 0, NULL, -1, -1);
|
|
return CARRY_ON;
|
|
}
|
|
|
|
if ((ret = get_parents(tb, h)) != CARRY_ON)
|
|
return ret;
|
|
|
|
/* get free space of neighbors */
|
|
rfree = get_rfree(tb, h);
|
|
lfree = get_lfree(tb, h);
|
|
|
|
/* determine maximal number of items we can fit into neighbors */
|
|
check_left(tb, h, lfree);
|
|
check_right(tb, h, rfree);
|
|
|
|
/*
|
|
* Balance condition for the internal node is valid.
|
|
* In this case we balance only if it leads to better packing.
|
|
*/
|
|
if (vn->vn_nr_item >= MIN_NR_KEY(Sh)) {
|
|
/*
|
|
* Here we join S[h] with one of its neighbors,
|
|
* which is impossible with greater values of new_nr_item.
|
|
*/
|
|
if (vn->vn_nr_item == MIN_NR_KEY(Sh)) {
|
|
/* All contents of S[h] can be moved to L[h]. */
|
|
if (tb->lnum[h] >= vn->vn_nr_item + 1) {
|
|
int n;
|
|
int order_L;
|
|
|
|
order_L =
|
|
((n =
|
|
PATH_H_B_ITEM_ORDER(tb->tb_path,
|
|
h)) ==
|
|
0) ? B_NR_ITEMS(tb->FL[h]) : n - 1;
|
|
n = dc_size(B_N_CHILD(tb->FL[h], order_L)) /
|
|
(DC_SIZE + KEY_SIZE);
|
|
set_parameters(tb, h, -n - 1, 0, 0, NULL, -1,
|
|
-1);
|
|
return CARRY_ON;
|
|
}
|
|
|
|
/* All contents of S[h] can be moved to R[h]. */
|
|
if (tb->rnum[h] >= vn->vn_nr_item + 1) {
|
|
int n;
|
|
int order_R;
|
|
|
|
order_R =
|
|
((n =
|
|
PATH_H_B_ITEM_ORDER(tb->tb_path,
|
|
h)) ==
|
|
B_NR_ITEMS(Fh)) ? 0 : n + 1;
|
|
n = dc_size(B_N_CHILD(tb->FR[h], order_R)) /
|
|
(DC_SIZE + KEY_SIZE);
|
|
set_parameters(tb, h, 0, -n - 1, 0, NULL, -1,
|
|
-1);
|
|
return CARRY_ON;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* All contents of S[h] can be moved to the neighbors
|
|
* (L[h] & R[h]).
|
|
*/
|
|
if (tb->rnum[h] + tb->lnum[h] >= vn->vn_nr_item + 1) {
|
|
int to_r;
|
|
|
|
to_r =
|
|
((MAX_NR_KEY(Sh) << 1) + 2 - tb->lnum[h] -
|
|
tb->rnum[h] + vn->vn_nr_item + 1) / 2 -
|
|
(MAX_NR_KEY(Sh) + 1 - tb->rnum[h]);
|
|
set_parameters(tb, h, vn->vn_nr_item + 1 - to_r, to_r,
|
|
0, NULL, -1, -1);
|
|
return CARRY_ON;
|
|
}
|
|
|
|
/* Balancing does not lead to better packing. */
|
|
set_parameters(tb, h, 0, 0, 1, NULL, -1, -1);
|
|
return NO_BALANCING_NEEDED;
|
|
}
|
|
|
|
/*
|
|
* Current node contain insufficient number of items.
|
|
* Balancing is required.
|
|
*/
|
|
/* Check whether we can merge S[h] with left neighbor. */
|
|
if (tb->lnum[h] >= vn->vn_nr_item + 1)
|
|
if (is_left_neighbor_in_cache(tb, h)
|
|
|| tb->rnum[h] < vn->vn_nr_item + 1 || !tb->FR[h]) {
|
|
int n;
|
|
int order_L;
|
|
|
|
order_L =
|
|
((n =
|
|
PATH_H_B_ITEM_ORDER(tb->tb_path,
|
|
h)) ==
|
|
0) ? B_NR_ITEMS(tb->FL[h]) : n - 1;
|
|
n = dc_size(B_N_CHILD(tb->FL[h], order_L)) / (DC_SIZE +
|
|
KEY_SIZE);
|
|
set_parameters(tb, h, -n - 1, 0, 0, NULL, -1, -1);
|
|
return CARRY_ON;
|
|
}
|
|
|
|
/* Check whether we can merge S[h] with right neighbor. */
|
|
if (tb->rnum[h] >= vn->vn_nr_item + 1) {
|
|
int n;
|
|
int order_R;
|
|
|
|
order_R =
|
|
((n =
|
|
PATH_H_B_ITEM_ORDER(tb->tb_path,
|
|
h)) == B_NR_ITEMS(Fh)) ? 0 : (n + 1);
|
|
n = dc_size(B_N_CHILD(tb->FR[h], order_R)) / (DC_SIZE +
|
|
KEY_SIZE);
|
|
set_parameters(tb, h, 0, -n - 1, 0, NULL, -1, -1);
|
|
return CARRY_ON;
|
|
}
|
|
|
|
/* All contents of S[h] can be moved to the neighbors (L[h] & R[h]). */
|
|
if (tb->rnum[h] + tb->lnum[h] >= vn->vn_nr_item + 1) {
|
|
int to_r;
|
|
|
|
to_r =
|
|
((MAX_NR_KEY(Sh) << 1) + 2 - tb->lnum[h] - tb->rnum[h] +
|
|
vn->vn_nr_item + 1) / 2 - (MAX_NR_KEY(Sh) + 1 -
|
|
tb->rnum[h]);
|
|
set_parameters(tb, h, vn->vn_nr_item + 1 - to_r, to_r, 0, NULL,
|
|
-1, -1);
|
|
return CARRY_ON;
|
|
}
|
|
|
|
/* For internal nodes try to borrow item from a neighbor */
|
|
RFALSE(!tb->FL[h] && !tb->FR[h], "vs-8235: trying to borrow for root");
|
|
|
|
/* Borrow one or two items from caching neighbor */
|
|
if (is_left_neighbor_in_cache(tb, h) || !tb->FR[h]) {
|
|
int from_l;
|
|
|
|
from_l =
|
|
(MAX_NR_KEY(Sh) + 1 - tb->lnum[h] + vn->vn_nr_item +
|
|
1) / 2 - (vn->vn_nr_item + 1);
|
|
set_parameters(tb, h, -from_l, 0, 1, NULL, -1, -1);
|
|
return CARRY_ON;
|
|
}
|
|
|
|
set_parameters(tb, h, 0,
|
|
-((MAX_NR_KEY(Sh) + 1 - tb->rnum[h] + vn->vn_nr_item +
|
|
1) / 2 - (vn->vn_nr_item + 1)), 1, NULL, -1, -1);
|
|
return CARRY_ON;
|
|
}
|
|
|
|
/*
|
|
* Check whether current node S[h] is balanced when Decreasing its size by
|
|
* Deleting or Truncating for LEAF node of S+tree.
|
|
* Calculate parameters for balancing for current level h.
|
|
* Parameters:
|
|
* tb tree_balance structure;
|
|
* h current level of the node;
|
|
* inum item number in S[h];
|
|
* mode i - insert, p - paste;
|
|
* Returns: 1 - schedule occurred;
|
|
* 0 - balancing for higher levels needed;
|
|
* -1 - no balancing for higher levels needed;
|
|
* -2 - no disk space.
|
|
*/
|
|
static int dc_check_balance_leaf(struct tree_balance *tb, int h)
|
|
{
|
|
struct virtual_node *vn = tb->tb_vn;
|
|
|
|
/*
|
|
* Number of bytes that must be deleted from
|
|
* (value is negative if bytes are deleted) buffer which
|
|
* contains node being balanced. The mnemonic is that the
|
|
* attempted change in node space used level is levbytes bytes.
|
|
*/
|
|
int levbytes;
|
|
|
|
/* the maximal item size */
|
|
int maxsize, ret;
|
|
|
|
/*
|
|
* S0 is the node whose balance is currently being checked,
|
|
* and F0 is its father.
|
|
*/
|
|
struct buffer_head *S0, *F0;
|
|
int lfree, rfree /* free space in L and R */ ;
|
|
|
|
S0 = PATH_H_PBUFFER(tb->tb_path, 0);
|
|
F0 = PATH_H_PPARENT(tb->tb_path, 0);
|
|
|
|
levbytes = tb->insert_size[h];
|
|
|
|
maxsize = MAX_CHILD_SIZE(S0); /* maximal possible size of an item */
|
|
|
|
if (!F0) { /* S[0] is the root now. */
|
|
|
|
RFALSE(-levbytes >= maxsize - B_FREE_SPACE(S0),
|
|
"vs-8240: attempt to create empty buffer tree");
|
|
|
|
set_parameters(tb, h, 0, 0, 1, NULL, -1, -1);
|
|
return NO_BALANCING_NEEDED;
|
|
}
|
|
|
|
if ((ret = get_parents(tb, h)) != CARRY_ON)
|
|
return ret;
|
|
|
|
/* get free space of neighbors */
|
|
rfree = get_rfree(tb, h);
|
|
lfree = get_lfree(tb, h);
|
|
|
|
create_virtual_node(tb, h);
|
|
|
|
/* if 3 leaves can be merge to one, set parameters and return */
|
|
if (are_leaves_removable(tb, lfree, rfree))
|
|
return CARRY_ON;
|
|
|
|
/*
|
|
* determine maximal number of items we can shift to the left/right
|
|
* neighbor and the maximal number of bytes that can flow to the
|
|
* left/right neighbor from the left/right most liquid item that
|
|
* cannot be shifted from S[0] entirely
|
|
*/
|
|
check_left(tb, h, lfree);
|
|
check_right(tb, h, rfree);
|
|
|
|
/* check whether we can merge S with left neighbor. */
|
|
if (tb->lnum[0] >= vn->vn_nr_item && tb->lbytes == -1)
|
|
if (is_left_neighbor_in_cache(tb, h) || ((tb->rnum[0] - ((tb->rbytes == -1) ? 0 : 1)) < vn->vn_nr_item) || /* S can not be merged with R */
|
|
!tb->FR[h]) {
|
|
|
|
RFALSE(!tb->FL[h],
|
|
"vs-8245: dc_check_balance_leaf: FL[h] must exist");
|
|
|
|
/* set parameter to merge S[0] with its left neighbor */
|
|
set_parameters(tb, h, -1, 0, 0, NULL, -1, -1);
|
|
return CARRY_ON;
|
|
}
|
|
|
|
/* check whether we can merge S[0] with right neighbor. */
|
|
if (tb->rnum[0] >= vn->vn_nr_item && tb->rbytes == -1) {
|
|
set_parameters(tb, h, 0, -1, 0, NULL, -1, -1);
|
|
return CARRY_ON;
|
|
}
|
|
|
|
/*
|
|
* All contents of S[0] can be moved to the neighbors (L[0] & R[0]).
|
|
* Set parameters and return
|
|
*/
|
|
if (is_leaf_removable(tb))
|
|
return CARRY_ON;
|
|
|
|
/* Balancing is not required. */
|
|
tb->s0num = vn->vn_nr_item;
|
|
set_parameters(tb, h, 0, 0, 1, NULL, -1, -1);
|
|
return NO_BALANCING_NEEDED;
|
|
}
|
|
|
|
/*
|
|
* Check whether current node S[h] is balanced when Decreasing its size by
|
|
* Deleting or Cutting.
|
|
* Calculate parameters for balancing for current level h.
|
|
* Parameters:
|
|
* tb tree_balance structure;
|
|
* h current level of the node;
|
|
* inum item number in S[h];
|
|
* mode d - delete, c - cut.
|
|
* Returns: 1 - schedule occurred;
|
|
* 0 - balancing for higher levels needed;
|
|
* -1 - no balancing for higher levels needed;
|
|
* -2 - no disk space.
|
|
*/
|
|
static int dc_check_balance(struct tree_balance *tb, int h)
|
|
{
|
|
RFALSE(!(PATH_H_PBUFFER(tb->tb_path, h)),
|
|
"vs-8250: S is not initialized");
|
|
|
|
if (h)
|
|
return dc_check_balance_internal(tb, h);
|
|
else
|
|
return dc_check_balance_leaf(tb, h);
|
|
}
|
|
|
|
/*
|
|
* Check whether current node S[h] is balanced.
|
|
* Calculate parameters for balancing for current level h.
|
|
* Parameters:
|
|
*
|
|
* tb tree_balance structure:
|
|
*
|
|
* tb is a large structure that must be read about in the header
|
|
* file at the same time as this procedure if the reader is
|
|
* to successfully understand this procedure
|
|
*
|
|
* h current level of the node;
|
|
* inum item number in S[h];
|
|
* mode i - insert, p - paste, d - delete, c - cut.
|
|
* Returns: 1 - schedule occurred;
|
|
* 0 - balancing for higher levels needed;
|
|
* -1 - no balancing for higher levels needed;
|
|
* -2 - no disk space.
|
|
*/
|
|
static int check_balance(int mode,
|
|
struct tree_balance *tb,
|
|
int h,
|
|
int inum,
|
|
int pos_in_item,
|
|
struct item_head *ins_ih, const void *data)
|
|
{
|
|
struct virtual_node *vn;
|
|
|
|
vn = tb->tb_vn = (struct virtual_node *)(tb->vn_buf);
|
|
vn->vn_free_ptr = (char *)(tb->tb_vn + 1);
|
|
vn->vn_mode = mode;
|
|
vn->vn_affected_item_num = inum;
|
|
vn->vn_pos_in_item = pos_in_item;
|
|
vn->vn_ins_ih = ins_ih;
|
|
vn->vn_data = data;
|
|
|
|
RFALSE(mode == M_INSERT && !vn->vn_ins_ih,
|
|
"vs-8255: ins_ih can not be 0 in insert mode");
|
|
|
|
/* Calculate balance parameters when size of node is increasing. */
|
|
if (tb->insert_size[h] > 0)
|
|
return ip_check_balance(tb, h);
|
|
|
|
/* Calculate balance parameters when size of node is decreasing. */
|
|
return dc_check_balance(tb, h);
|
|
}
|
|
|
|
/* Check whether parent at the path is the really parent of the current node.*/
|
|
static int get_direct_parent(struct tree_balance *tb, int h)
|
|
{
|
|
struct buffer_head *bh;
|
|
struct treepath *path = tb->tb_path;
|
|
int position,
|
|
path_offset = PATH_H_PATH_OFFSET(tb->tb_path, h);
|
|
|
|
/* We are in the root or in the new root. */
|
|
if (path_offset <= FIRST_PATH_ELEMENT_OFFSET) {
|
|
|
|
RFALSE(path_offset < FIRST_PATH_ELEMENT_OFFSET - 1,
|
|
"PAP-8260: invalid offset in the path");
|
|
|
|
if (PATH_OFFSET_PBUFFER(path, FIRST_PATH_ELEMENT_OFFSET)->
|
|
b_blocknr == SB_ROOT_BLOCK(tb->tb_sb)) {
|
|
/* Root is not changed. */
|
|
PATH_OFFSET_PBUFFER(path, path_offset - 1) = NULL;
|
|
PATH_OFFSET_POSITION(path, path_offset - 1) = 0;
|
|
return CARRY_ON;
|
|
}
|
|
/* Root is changed and we must recalculate the path. */
|
|
return REPEAT_SEARCH;
|
|
}
|
|
|
|
/* Parent in the path is not in the tree. */
|
|
if (!B_IS_IN_TREE
|
|
(bh = PATH_OFFSET_PBUFFER(path, path_offset - 1)))
|
|
return REPEAT_SEARCH;
|
|
|
|
if ((position =
|
|
PATH_OFFSET_POSITION(path,
|
|
path_offset - 1)) > B_NR_ITEMS(bh))
|
|
return REPEAT_SEARCH;
|
|
|
|
/* Parent in the path is not parent of the current node in the tree. */
|
|
if (B_N_CHILD_NUM(bh, position) !=
|
|
PATH_OFFSET_PBUFFER(path, path_offset)->b_blocknr)
|
|
return REPEAT_SEARCH;
|
|
|
|
if (buffer_locked(bh)) {
|
|
int depth = reiserfs_write_unlock_nested(tb->tb_sb);
|
|
__wait_on_buffer(bh);
|
|
reiserfs_write_lock_nested(tb->tb_sb, depth);
|
|
if (FILESYSTEM_CHANGED_TB(tb))
|
|
return REPEAT_SEARCH;
|
|
}
|
|
|
|
/*
|
|
* Parent in the path is unlocked and really parent
|
|
* of the current node.
|
|
*/
|
|
return CARRY_ON;
|
|
}
|
|
|
|
/*
|
|
* Using lnum[h] and rnum[h] we should determine what neighbors
|
|
* of S[h] we
|
|
* need in order to balance S[h], and get them if necessary.
|
|
* Returns: SCHEDULE_OCCURRED - schedule occurred while the function worked;
|
|
* CARRY_ON - schedule didn't occur while the function worked;
|
|
*/
|
|
static int get_neighbors(struct tree_balance *tb, int h)
|
|
{
|
|
int child_position,
|
|
path_offset = PATH_H_PATH_OFFSET(tb->tb_path, h + 1);
|
|
unsigned long son_number;
|
|
struct super_block *sb = tb->tb_sb;
|
|
struct buffer_head *bh;
|
|
int depth;
|
|
|
|
PROC_INFO_INC(sb, get_neighbors[h]);
|
|
|
|
if (tb->lnum[h]) {
|
|
/* We need left neighbor to balance S[h]. */
|
|
PROC_INFO_INC(sb, need_l_neighbor[h]);
|
|
bh = PATH_OFFSET_PBUFFER(tb->tb_path, path_offset);
|
|
|
|
RFALSE(bh == tb->FL[h] &&
|
|
!PATH_OFFSET_POSITION(tb->tb_path, path_offset),
|
|
"PAP-8270: invalid position in the parent");
|
|
|
|
child_position =
|
|
(bh ==
|
|
tb->FL[h]) ? tb->lkey[h] : B_NR_ITEMS(tb->
|
|
FL[h]);
|
|
son_number = B_N_CHILD_NUM(tb->FL[h], child_position);
|
|
depth = reiserfs_write_unlock_nested(tb->tb_sb);
|
|
bh = sb_bread(sb, son_number);
|
|
reiserfs_write_lock_nested(tb->tb_sb, depth);
|
|
if (!bh)
|
|
return IO_ERROR;
|
|
if (FILESYSTEM_CHANGED_TB(tb)) {
|
|
brelse(bh);
|
|
PROC_INFO_INC(sb, get_neighbors_restart[h]);
|
|
return REPEAT_SEARCH;
|
|
}
|
|
|
|
RFALSE(!B_IS_IN_TREE(tb->FL[h]) ||
|
|
child_position > B_NR_ITEMS(tb->FL[h]) ||
|
|
B_N_CHILD_NUM(tb->FL[h], child_position) !=
|
|
bh->b_blocknr, "PAP-8275: invalid parent");
|
|
RFALSE(!B_IS_IN_TREE(bh), "PAP-8280: invalid child");
|
|
RFALSE(!h &&
|
|
B_FREE_SPACE(bh) !=
|
|
MAX_CHILD_SIZE(bh) -
|
|
dc_size(B_N_CHILD(tb->FL[0], child_position)),
|
|
"PAP-8290: invalid child size of left neighbor");
|
|
|
|
brelse(tb->L[h]);
|
|
tb->L[h] = bh;
|
|
}
|
|
|
|
/* We need right neighbor to balance S[path_offset]. */
|
|
if (tb->rnum[h]) {
|
|
PROC_INFO_INC(sb, need_r_neighbor[h]);
|
|
bh = PATH_OFFSET_PBUFFER(tb->tb_path, path_offset);
|
|
|
|
RFALSE(bh == tb->FR[h] &&
|
|
PATH_OFFSET_POSITION(tb->tb_path,
|
|
path_offset) >=
|
|
B_NR_ITEMS(bh),
|
|
"PAP-8295: invalid position in the parent");
|
|
|
|
child_position =
|
|
(bh == tb->FR[h]) ? tb->rkey[h] + 1 : 0;
|
|
son_number = B_N_CHILD_NUM(tb->FR[h], child_position);
|
|
depth = reiserfs_write_unlock_nested(tb->tb_sb);
|
|
bh = sb_bread(sb, son_number);
|
|
reiserfs_write_lock_nested(tb->tb_sb, depth);
|
|
if (!bh)
|
|
return IO_ERROR;
|
|
if (FILESYSTEM_CHANGED_TB(tb)) {
|
|
brelse(bh);
|
|
PROC_INFO_INC(sb, get_neighbors_restart[h]);
|
|
return REPEAT_SEARCH;
|
|
}
|
|
brelse(tb->R[h]);
|
|
tb->R[h] = bh;
|
|
|
|
RFALSE(!h
|
|
&& B_FREE_SPACE(bh) !=
|
|
MAX_CHILD_SIZE(bh) -
|
|
dc_size(B_N_CHILD(tb->FR[0], child_position)),
|
|
"PAP-8300: invalid child size of right neighbor (%d != %d - %d)",
|
|
B_FREE_SPACE(bh), MAX_CHILD_SIZE(bh),
|
|
dc_size(B_N_CHILD(tb->FR[0], child_position)));
|
|
|
|
}
|
|
return CARRY_ON;
|
|
}
|
|
|
|
static int get_virtual_node_size(struct super_block *sb, struct buffer_head *bh)
|
|
{
|
|
int max_num_of_items;
|
|
int max_num_of_entries;
|
|
unsigned long blocksize = sb->s_blocksize;
|
|
|
|
#define MIN_NAME_LEN 1
|
|
|
|
max_num_of_items = (blocksize - BLKH_SIZE) / (IH_SIZE + MIN_ITEM_LEN);
|
|
max_num_of_entries = (blocksize - BLKH_SIZE - IH_SIZE) /
|
|
(DEH_SIZE + MIN_NAME_LEN);
|
|
|
|
return sizeof(struct virtual_node) +
|
|
max(max_num_of_items * sizeof(struct virtual_item),
|
|
sizeof(struct virtual_item) + sizeof(struct direntry_uarea) +
|
|
(max_num_of_entries - 1) * sizeof(__u16));
|
|
}
|
|
|
|
/*
|
|
* maybe we should fail balancing we are going to perform when kmalloc
|
|
* fails several times. But now it will loop until kmalloc gets
|
|
* required memory
|
|
*/
|
|
static int get_mem_for_virtual_node(struct tree_balance *tb)
|
|
{
|
|
int check_fs = 0;
|
|
int size;
|
|
char *buf;
|
|
|
|
size = get_virtual_node_size(tb->tb_sb, PATH_PLAST_BUFFER(tb->tb_path));
|
|
|
|
/* we have to allocate more memory for virtual node */
|
|
if (size > tb->vn_buf_size) {
|
|
if (tb->vn_buf) {
|
|
/* free memory allocated before */
|
|
kfree(tb->vn_buf);
|
|
/* this is not needed if kfree is atomic */
|
|
check_fs = 1;
|
|
}
|
|
|
|
/* virtual node requires now more memory */
|
|
tb->vn_buf_size = size;
|
|
|
|
/* get memory for virtual item */
|
|
buf = kmalloc(size, GFP_ATOMIC | __GFP_NOWARN);
|
|
if (!buf) {
|
|
/*
|
|
* getting memory with GFP_KERNEL priority may involve
|
|
* balancing now (due to indirect_to_direct conversion
|
|
* on dcache shrinking). So, release path and collected
|
|
* resources here
|
|
*/
|
|
free_buffers_in_tb(tb);
|
|
buf = kmalloc(size, GFP_NOFS);
|
|
if (!buf) {
|
|
tb->vn_buf_size = 0;
|
|
}
|
|
tb->vn_buf = buf;
|
|
schedule();
|
|
return REPEAT_SEARCH;
|
|
}
|
|
|
|
tb->vn_buf = buf;
|
|
}
|
|
|
|
if (check_fs && FILESYSTEM_CHANGED_TB(tb))
|
|
return REPEAT_SEARCH;
|
|
|
|
return CARRY_ON;
|
|
}
|
|
|
|
#ifdef CONFIG_REISERFS_CHECK
|
|
static void tb_buffer_sanity_check(struct super_block *sb,
|
|
struct buffer_head *bh,
|
|
const char *descr, int level)
|
|
{
|
|
if (bh) {
|
|
if (atomic_read(&(bh->b_count)) <= 0)
|
|
|
|
reiserfs_panic(sb, "jmacd-1", "negative or zero "
|
|
"reference counter for buffer %s[%d] "
|
|
"(%b)", descr, level, bh);
|
|
|
|
if (!buffer_uptodate(bh))
|
|
reiserfs_panic(sb, "jmacd-2", "buffer is not up "
|
|
"to date %s[%d] (%b)",
|
|
descr, level, bh);
|
|
|
|
if (!B_IS_IN_TREE(bh))
|
|
reiserfs_panic(sb, "jmacd-3", "buffer is not "
|
|
"in tree %s[%d] (%b)",
|
|
descr, level, bh);
|
|
|
|
if (bh->b_bdev != sb->s_bdev)
|
|
reiserfs_panic(sb, "jmacd-4", "buffer has wrong "
|
|
"device %s[%d] (%b)",
|
|
descr, level, bh);
|
|
|
|
if (bh->b_size != sb->s_blocksize)
|
|
reiserfs_panic(sb, "jmacd-5", "buffer has wrong "
|
|
"blocksize %s[%d] (%b)",
|
|
descr, level, bh);
|
|
|
|
if (bh->b_blocknr > SB_BLOCK_COUNT(sb))
|
|
reiserfs_panic(sb, "jmacd-6", "buffer block "
|
|
"number too high %s[%d] (%b)",
|
|
descr, level, bh);
|
|
}
|
|
}
|
|
#else
|
|
static void tb_buffer_sanity_check(struct super_block *sb,
|
|
struct buffer_head *bh,
|
|
const char *descr, int level)
|
|
{;
|
|
}
|
|
#endif
|
|
|
|
static int clear_all_dirty_bits(struct super_block *s, struct buffer_head *bh)
|
|
{
|
|
return reiserfs_prepare_for_journal(s, bh, 0);
|
|
}
|
|
|
|
static int wait_tb_buffers_until_unlocked(struct tree_balance *tb)
|
|
{
|
|
struct buffer_head *locked;
|
|
#ifdef CONFIG_REISERFS_CHECK
|
|
int repeat_counter = 0;
|
|
#endif
|
|
int i;
|
|
|
|
do {
|
|
|
|
locked = NULL;
|
|
|
|
for (i = tb->tb_path->path_length;
|
|
!locked && i > ILLEGAL_PATH_ELEMENT_OFFSET; i--) {
|
|
if (PATH_OFFSET_PBUFFER(tb->tb_path, i)) {
|
|
/*
|
|
* if I understand correctly, we can only
|
|
* be sure the last buffer in the path is
|
|
* in the tree --clm
|
|
*/
|
|
#ifdef CONFIG_REISERFS_CHECK
|
|
if (PATH_PLAST_BUFFER(tb->tb_path) ==
|
|
PATH_OFFSET_PBUFFER(tb->tb_path, i))
|
|
tb_buffer_sanity_check(tb->tb_sb,
|
|
PATH_OFFSET_PBUFFER
|
|
(tb->tb_path,
|
|
i), "S",
|
|
tb->tb_path->
|
|
path_length - i);
|
|
#endif
|
|
if (!clear_all_dirty_bits(tb->tb_sb,
|
|
PATH_OFFSET_PBUFFER
|
|
(tb->tb_path,
|
|
i))) {
|
|
locked =
|
|
PATH_OFFSET_PBUFFER(tb->tb_path,
|
|
i);
|
|
}
|
|
}
|
|
}
|
|
|
|
for (i = 0; !locked && i < MAX_HEIGHT && tb->insert_size[i];
|
|
i++) {
|
|
|
|
if (tb->lnum[i]) {
|
|
|
|
if (tb->L[i]) {
|
|
tb_buffer_sanity_check(tb->tb_sb,
|
|
tb->L[i],
|
|
"L", i);
|
|
if (!clear_all_dirty_bits
|
|
(tb->tb_sb, tb->L[i]))
|
|
locked = tb->L[i];
|
|
}
|
|
|
|
if (!locked && tb->FL[i]) {
|
|
tb_buffer_sanity_check(tb->tb_sb,
|
|
tb->FL[i],
|
|
"FL", i);
|
|
if (!clear_all_dirty_bits
|
|
(tb->tb_sb, tb->FL[i]))
|
|
locked = tb->FL[i];
|
|
}
|
|
|
|
if (!locked && tb->CFL[i]) {
|
|
tb_buffer_sanity_check(tb->tb_sb,
|
|
tb->CFL[i],
|
|
"CFL", i);
|
|
if (!clear_all_dirty_bits
|
|
(tb->tb_sb, tb->CFL[i]))
|
|
locked = tb->CFL[i];
|
|
}
|
|
|
|
}
|
|
|
|
if (!locked && (tb->rnum[i])) {
|
|
|
|
if (tb->R[i]) {
|
|
tb_buffer_sanity_check(tb->tb_sb,
|
|
tb->R[i],
|
|
"R", i);
|
|
if (!clear_all_dirty_bits
|
|
(tb->tb_sb, tb->R[i]))
|
|
locked = tb->R[i];
|
|
}
|
|
|
|
if (!locked && tb->FR[i]) {
|
|
tb_buffer_sanity_check(tb->tb_sb,
|
|
tb->FR[i],
|
|
"FR", i);
|
|
if (!clear_all_dirty_bits
|
|
(tb->tb_sb, tb->FR[i]))
|
|
locked = tb->FR[i];
|
|
}
|
|
|
|
if (!locked && tb->CFR[i]) {
|
|
tb_buffer_sanity_check(tb->tb_sb,
|
|
tb->CFR[i],
|
|
"CFR", i);
|
|
if (!clear_all_dirty_bits
|
|
(tb->tb_sb, tb->CFR[i]))
|
|
locked = tb->CFR[i];
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* as far as I can tell, this is not required. The FEB list
|
|
* seems to be full of newly allocated nodes, which will
|
|
* never be locked, dirty, or anything else.
|
|
* To be safe, I'm putting in the checks and waits in.
|
|
* For the moment, they are needed to keep the code in
|
|
* journal.c from complaining about the buffer.
|
|
* That code is inside CONFIG_REISERFS_CHECK as well. --clm
|
|
*/
|
|
for (i = 0; !locked && i < MAX_FEB_SIZE; i++) {
|
|
if (tb->FEB[i]) {
|
|
if (!clear_all_dirty_bits
|
|
(tb->tb_sb, tb->FEB[i]))
|
|
locked = tb->FEB[i];
|
|
}
|
|
}
|
|
|
|
if (locked) {
|
|
int depth;
|
|
#ifdef CONFIG_REISERFS_CHECK
|
|
repeat_counter++;
|
|
if ((repeat_counter % 10000) == 0) {
|
|
reiserfs_warning(tb->tb_sb, "reiserfs-8200",
|
|
"too many iterations waiting "
|
|
"for buffer to unlock "
|
|
"(%b)", locked);
|
|
|
|
/* Don't loop forever. Try to recover from possible error. */
|
|
|
|
return (FILESYSTEM_CHANGED_TB(tb)) ?
|
|
REPEAT_SEARCH : CARRY_ON;
|
|
}
|
|
#endif
|
|
depth = reiserfs_write_unlock_nested(tb->tb_sb);
|
|
__wait_on_buffer(locked);
|
|
reiserfs_write_lock_nested(tb->tb_sb, depth);
|
|
if (FILESYSTEM_CHANGED_TB(tb))
|
|
return REPEAT_SEARCH;
|
|
}
|
|
|
|
} while (locked);
|
|
|
|
return CARRY_ON;
|
|
}
|
|
|
|
/*
|
|
* Prepare for balancing, that is
|
|
* get all necessary parents, and neighbors;
|
|
* analyze what and where should be moved;
|
|
* get sufficient number of new nodes;
|
|
* Balancing will start only after all resources will be collected at a time.
|
|
*
|
|
* When ported to SMP kernels, only at the last moment after all needed nodes
|
|
* are collected in cache, will the resources be locked using the usual
|
|
* textbook ordered lock acquisition algorithms. Note that ensuring that
|
|
* this code neither write locks what it does not need to write lock nor locks
|
|
* out of order will be a pain in the butt that could have been avoided.
|
|
* Grumble grumble. -Hans
|
|
*
|
|
* fix is meant in the sense of render unchanging
|
|
*
|
|
* Latency might be improved by first gathering a list of what buffers
|
|
* are needed and then getting as many of them in parallel as possible? -Hans
|
|
*
|
|
* Parameters:
|
|
* op_mode i - insert, d - delete, c - cut (truncate), p - paste (append)
|
|
* tb tree_balance structure;
|
|
* inum item number in S[h];
|
|
* pos_in_item - comment this if you can
|
|
* ins_ih item head of item being inserted
|
|
* data inserted item or data to be pasted
|
|
* Returns: 1 - schedule occurred while the function worked;
|
|
* 0 - schedule didn't occur while the function worked;
|
|
* -1 - if no_disk_space
|
|
*/
|
|
|
|
int fix_nodes(int op_mode, struct tree_balance *tb,
|
|
struct item_head *ins_ih, const void *data)
|
|
{
|
|
int ret, h, item_num = PATH_LAST_POSITION(tb->tb_path);
|
|
int pos_in_item;
|
|
|
|
/*
|
|
* we set wait_tb_buffers_run when we have to restore any dirty
|
|
* bits cleared during wait_tb_buffers_run
|
|
*/
|
|
int wait_tb_buffers_run = 0;
|
|
struct buffer_head *tbS0 = PATH_PLAST_BUFFER(tb->tb_path);
|
|
|
|
++REISERFS_SB(tb->tb_sb)->s_fix_nodes;
|
|
|
|
pos_in_item = tb->tb_path->pos_in_item;
|
|
|
|
tb->fs_gen = get_generation(tb->tb_sb);
|
|
|
|
/*
|
|
* we prepare and log the super here so it will already be in the
|
|
* transaction when do_balance needs to change it.
|
|
* This way do_balance won't have to schedule when trying to prepare
|
|
* the super for logging
|
|
*/
|
|
reiserfs_prepare_for_journal(tb->tb_sb,
|
|
SB_BUFFER_WITH_SB(tb->tb_sb), 1);
|
|
journal_mark_dirty(tb->transaction_handle,
|
|
SB_BUFFER_WITH_SB(tb->tb_sb));
|
|
if (FILESYSTEM_CHANGED_TB(tb))
|
|
return REPEAT_SEARCH;
|
|
|
|
/* if it possible in indirect_to_direct conversion */
|
|
if (buffer_locked(tbS0)) {
|
|
int depth = reiserfs_write_unlock_nested(tb->tb_sb);
|
|
__wait_on_buffer(tbS0);
|
|
reiserfs_write_lock_nested(tb->tb_sb, depth);
|
|
if (FILESYSTEM_CHANGED_TB(tb))
|
|
return REPEAT_SEARCH;
|
|
}
|
|
#ifdef CONFIG_REISERFS_CHECK
|
|
if (REISERFS_SB(tb->tb_sb)->cur_tb) {
|
|
print_cur_tb("fix_nodes");
|
|
reiserfs_panic(tb->tb_sb, "PAP-8305",
|
|
"there is pending do_balance");
|
|
}
|
|
|
|
if (!buffer_uptodate(tbS0) || !B_IS_IN_TREE(tbS0))
|
|
reiserfs_panic(tb->tb_sb, "PAP-8320", "S[0] (%b %z) is "
|
|
"not uptodate at the beginning of fix_nodes "
|
|
"or not in tree (mode %c)",
|
|
tbS0, tbS0, op_mode);
|
|
|
|
/* Check parameters. */
|
|
switch (op_mode) {
|
|
case M_INSERT:
|
|
if (item_num <= 0 || item_num > B_NR_ITEMS(tbS0))
|
|
reiserfs_panic(tb->tb_sb, "PAP-8330", "Incorrect "
|
|
"item number %d (in S0 - %d) in case "
|
|
"of insert", item_num,
|
|
B_NR_ITEMS(tbS0));
|
|
break;
|
|
case M_PASTE:
|
|
case M_DELETE:
|
|
case M_CUT:
|
|
if (item_num < 0 || item_num >= B_NR_ITEMS(tbS0)) {
|
|
print_block(tbS0, 0, -1, -1);
|
|
reiserfs_panic(tb->tb_sb, "PAP-8335", "Incorrect "
|
|
"item number(%d); mode = %c "
|
|
"insert_size = %d",
|
|
item_num, op_mode,
|
|
tb->insert_size[0]);
|
|
}
|
|
break;
|
|
default:
|
|
reiserfs_panic(tb->tb_sb, "PAP-8340", "Incorrect mode "
|
|
"of operation");
|
|
}
|
|
#endif
|
|
|
|
if (get_mem_for_virtual_node(tb) == REPEAT_SEARCH)
|
|
/* FIXME: maybe -ENOMEM when tb->vn_buf == 0? Now just repeat */
|
|
return REPEAT_SEARCH;
|
|
|
|
/* Starting from the leaf level; for all levels h of the tree. */
|
|
for (h = 0; h < MAX_HEIGHT && tb->insert_size[h]; h++) {
|
|
ret = get_direct_parent(tb, h);
|
|
if (ret != CARRY_ON)
|
|
goto repeat;
|
|
|
|
ret = check_balance(op_mode, tb, h, item_num,
|
|
pos_in_item, ins_ih, data);
|
|
if (ret != CARRY_ON) {
|
|
if (ret == NO_BALANCING_NEEDED) {
|
|
/* No balancing for higher levels needed. */
|
|
ret = get_neighbors(tb, h);
|
|
if (ret != CARRY_ON)
|
|
goto repeat;
|
|
if (h != MAX_HEIGHT - 1)
|
|
tb->insert_size[h + 1] = 0;
|
|
/*
|
|
* ok, analysis and resource gathering
|
|
* are complete
|
|
*/
|
|
break;
|
|
}
|
|
goto repeat;
|
|
}
|
|
|
|
ret = get_neighbors(tb, h);
|
|
if (ret != CARRY_ON)
|
|
goto repeat;
|
|
|
|
/*
|
|
* No disk space, or schedule occurred and analysis may be
|
|
* invalid and needs to be redone.
|
|
*/
|
|
ret = get_empty_nodes(tb, h);
|
|
if (ret != CARRY_ON)
|
|
goto repeat;
|
|
|
|
/*
|
|
* We have a positive insert size but no nodes exist on this
|
|
* level, this means that we are creating a new root.
|
|
*/
|
|
if (!PATH_H_PBUFFER(tb->tb_path, h)) {
|
|
|
|
RFALSE(tb->blknum[h] != 1,
|
|
"PAP-8350: creating new empty root");
|
|
|
|
if (h < MAX_HEIGHT - 1)
|
|
tb->insert_size[h + 1] = 0;
|
|
} else if (!PATH_H_PBUFFER(tb->tb_path, h + 1)) {
|
|
/*
|
|
* The tree needs to be grown, so this node S[h]
|
|
* which is the root node is split into two nodes,
|
|
* and a new node (S[h+1]) will be created to
|
|
* become the root node.
|
|
*/
|
|
if (tb->blknum[h] > 1) {
|
|
|
|
RFALSE(h == MAX_HEIGHT - 1,
|
|
"PAP-8355: attempt to create too high of a tree");
|
|
|
|
tb->insert_size[h + 1] =
|
|
(DC_SIZE +
|
|
KEY_SIZE) * (tb->blknum[h] - 1) +
|
|
DC_SIZE;
|
|
} else if (h < MAX_HEIGHT - 1)
|
|
tb->insert_size[h + 1] = 0;
|
|
} else
|
|
tb->insert_size[h + 1] =
|
|
(DC_SIZE + KEY_SIZE) * (tb->blknum[h] - 1);
|
|
}
|
|
|
|
ret = wait_tb_buffers_until_unlocked(tb);
|
|
if (ret == CARRY_ON) {
|
|
if (FILESYSTEM_CHANGED_TB(tb)) {
|
|
wait_tb_buffers_run = 1;
|
|
ret = REPEAT_SEARCH;
|
|
goto repeat;
|
|
} else {
|
|
return CARRY_ON;
|
|
}
|
|
} else {
|
|
wait_tb_buffers_run = 1;
|
|
goto repeat;
|
|
}
|
|
|
|
repeat:
|
|
/*
|
|
* fix_nodes was unable to perform its calculation due to
|
|
* filesystem got changed under us, lack of free disk space or i/o
|
|
* failure. If the first is the case - the search will be
|
|
* repeated. For now - free all resources acquired so far except
|
|
* for the new allocated nodes
|
|
*/
|
|
{
|
|
int i;
|
|
|
|
/* Release path buffers. */
|
|
if (wait_tb_buffers_run) {
|
|
pathrelse_and_restore(tb->tb_sb, tb->tb_path);
|
|
} else {
|
|
pathrelse(tb->tb_path);
|
|
}
|
|
/* brelse all resources collected for balancing */
|
|
for (i = 0; i < MAX_HEIGHT; i++) {
|
|
if (wait_tb_buffers_run) {
|
|
reiserfs_restore_prepared_buffer(tb->tb_sb,
|
|
tb->L[i]);
|
|
reiserfs_restore_prepared_buffer(tb->tb_sb,
|
|
tb->R[i]);
|
|
reiserfs_restore_prepared_buffer(tb->tb_sb,
|
|
tb->FL[i]);
|
|
reiserfs_restore_prepared_buffer(tb->tb_sb,
|
|
tb->FR[i]);
|
|
reiserfs_restore_prepared_buffer(tb->tb_sb,
|
|
tb->
|
|
CFL[i]);
|
|
reiserfs_restore_prepared_buffer(tb->tb_sb,
|
|
tb->
|
|
CFR[i]);
|
|
}
|
|
|
|
brelse(tb->L[i]);
|
|
brelse(tb->R[i]);
|
|
brelse(tb->FL[i]);
|
|
brelse(tb->FR[i]);
|
|
brelse(tb->CFL[i]);
|
|
brelse(tb->CFR[i]);
|
|
|
|
tb->L[i] = NULL;
|
|
tb->R[i] = NULL;
|
|
tb->FL[i] = NULL;
|
|
tb->FR[i] = NULL;
|
|
tb->CFL[i] = NULL;
|
|
tb->CFR[i] = NULL;
|
|
}
|
|
|
|
if (wait_tb_buffers_run) {
|
|
for (i = 0; i < MAX_FEB_SIZE; i++) {
|
|
if (tb->FEB[i])
|
|
reiserfs_restore_prepared_buffer
|
|
(tb->tb_sb, tb->FEB[i]);
|
|
}
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
}
|
|
|
|
void unfix_nodes(struct tree_balance *tb)
|
|
{
|
|
int i;
|
|
|
|
/* Release path buffers. */
|
|
pathrelse_and_restore(tb->tb_sb, tb->tb_path);
|
|
|
|
/* brelse all resources collected for balancing */
|
|
for (i = 0; i < MAX_HEIGHT; i++) {
|
|
reiserfs_restore_prepared_buffer(tb->tb_sb, tb->L[i]);
|
|
reiserfs_restore_prepared_buffer(tb->tb_sb, tb->R[i]);
|
|
reiserfs_restore_prepared_buffer(tb->tb_sb, tb->FL[i]);
|
|
reiserfs_restore_prepared_buffer(tb->tb_sb, tb->FR[i]);
|
|
reiserfs_restore_prepared_buffer(tb->tb_sb, tb->CFL[i]);
|
|
reiserfs_restore_prepared_buffer(tb->tb_sb, tb->CFR[i]);
|
|
|
|
brelse(tb->L[i]);
|
|
brelse(tb->R[i]);
|
|
brelse(tb->FL[i]);
|
|
brelse(tb->FR[i]);
|
|
brelse(tb->CFL[i]);
|
|
brelse(tb->CFR[i]);
|
|
}
|
|
|
|
/* deal with list of allocated (used and unused) nodes */
|
|
for (i = 0; i < MAX_FEB_SIZE; i++) {
|
|
if (tb->FEB[i]) {
|
|
b_blocknr_t blocknr = tb->FEB[i]->b_blocknr;
|
|
/*
|
|
* de-allocated block which was not used by
|
|
* balancing and bforget about buffer for it
|
|
*/
|
|
brelse(tb->FEB[i]);
|
|
reiserfs_free_block(tb->transaction_handle, NULL,
|
|
blocknr, 0);
|
|
}
|
|
if (tb->used[i]) {
|
|
/* release used as new nodes including a new root */
|
|
brelse(tb->used[i]);
|
|
}
|
|
}
|
|
|
|
kfree(tb->vn_buf);
|
|
|
|
}
|