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fix_node.c
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fix_node.c
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/*
* Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
*/
/**
** old_item_num
** old_entry_num
** set_entry_sizes
** create_virtual_node
** check_left
** check_right
** directory_part_size
** get_num_ver
** set_parameters
** is_leaf_removable
** are_leaves_removable
** get_empty_nodes
** get_lfree
** get_rfree
** is_left_neighbor_in_cache
** decrement_key
** get_far_parent
** get_parents
** can_node_be_removed
** ip_check_balance
** dc_check_balance_internal
** dc_check_balance_leaf
** dc_check_balance
** check_balance
** get_direct_parent
** get_neighbors
** fix_nodes
**
**
**/
#include <linux/time.h>
#include <linux/slab.h>
#include <linux/string.h>
#include "reiserfs.h"
#include <linux/buffer_head.h>
/* To make any changes in the tree we find a node, that contains item
to be changed/deleted or position in the node we insert a new item
to. We call this node S. To do balancing we need to decide what we
will shift to left/right neighbor, or to a new node, where new item
will be etc. To make this analysis simpler we build virtual
node. Virtual node is an array of items, that will replace items of
node S. (For instance if we are going to delete an item, virtual
node does not contain it). Virtual node keeps information about
item sizes and types, mergeability of first and last items, sizes
of all entries in directory item. We use this array of items when
calculating what we can shift to neighbors and how many nodes we
have to have if we do not any shiftings, if we shift to left/right
neighbor or to both. */
/* taking item number in virtual node, returns number of item, that it has in source buffer */
static inline int old_item_num(int new_num, int affected_item_num, int mode)
{
if (mode == M_PASTE || mode == M_CUT || new_num < affected_item_num)
return new_num;
if (mode == M_INSERT) {
RFALSE(new_num == 0,
"vs-8005: for INSERT mode and item number of inserted item");
return new_num - 1;
}
RFALSE(mode != M_DELETE,
"vs-8010: old_item_num: mode must be M_DELETE (mode = \'%c\'",
mode);
/* delete mode */
return new_num + 1;
}
static void create_virtual_node(struct tree_balance *tb, int h)
{
struct item_head *ih;
struct virtual_node *vn = tb->tb_vn;
int new_num;
struct buffer_head *Sh; /* this comes from tb->S[h] */
Sh = PATH_H_PBUFFER(tb->tb_path, h);
/* size of changed node */
vn->vn_size =
MAX_CHILD_SIZE(Sh) - B_FREE_SPACE(Sh) + tb->insert_size[h];
/* for internal nodes array if virtual items is not created */
if (h) {
vn->vn_nr_item = (vn->vn_size - DC_SIZE) / (DC_SIZE + KEY_SIZE);
return;
}
/* number of items in virtual node */
vn->vn_nr_item =
B_NR_ITEMS(Sh) + ((vn->vn_mode == M_INSERT) ? 1 : 0) -
((vn->vn_mode == M_DELETE) ? 1 : 0);
/* first virtual item */
vn->vn_vi = (struct virtual_item *)(tb->tb_vn + 1);
memset(vn->vn_vi, 0, vn->vn_nr_item * sizeof(struct virtual_item));
vn->vn_free_ptr += vn->vn_nr_item * sizeof(struct virtual_item);
/* first item in the node */
ih = B_N_PITEM_HEAD(Sh, 0);
/* define the mergeability for 0-th item (if it is not being deleted) */
if (op_is_left_mergeable(&(ih->ih_key), Sh->b_size)
&& (vn->vn_mode != M_DELETE || vn->vn_affected_item_num))
vn->vn_vi[0].vi_type |= VI_TYPE_LEFT_MERGEABLE;
/* go through all items those remain in the virtual node (except for the new (inserted) one) */
for (new_num = 0; new_num < vn->vn_nr_item; new_num++) {
int j;
struct virtual_item *vi = vn->vn_vi + new_num;
int is_affected =
((new_num != vn->vn_affected_item_num) ? 0 : 1);
if (is_affected && vn->vn_mode == M_INSERT)
continue;
/* get item number in source node */
j = old_item_num(new_num, vn->vn_affected_item_num,
vn->vn_mode);
vi->vi_item_len += ih_item_len(ih + j) + IH_SIZE;
vi->vi_ih = ih + j;
vi->vi_item = B_I_PITEM(Sh, ih + j);
vi->vi_uarea = vn->vn_free_ptr;
// FIXME: there is no check, that item operation did not
// consume too much memory
vn->vn_free_ptr +=
op_create_vi(vn, vi, is_affected, tb->insert_size[0]);
if (tb->vn_buf + tb->vn_buf_size < vn->vn_free_ptr)
reiserfs_panic(tb->tb_sb, "vs-8030",
"virtual node space consumed");
if (!is_affected)
/* this is not being changed */
continue;
if (vn->vn_mode == M_PASTE || vn->vn_mode == M_CUT) {
vn->vn_vi[new_num].vi_item_len += tb->insert_size[0];
vi->vi_new_data = vn->vn_data; // pointer to data which is going to be pasted
}
}
/* virtual inserted item is not defined yet */
if (vn->vn_mode == M_INSERT) {
struct virtual_item *vi = vn->vn_vi + vn->vn_affected_item_num;
RFALSE(vn->vn_ins_ih == NULL,
"vs-8040: item header of inserted item is not specified");
vi->vi_item_len = tb->insert_size[0];
vi->vi_ih = vn->vn_ins_ih;
vi->vi_item = vn->vn_data;
vi->vi_uarea = vn->vn_free_ptr;
op_create_vi(vn, vi, 0 /*not pasted or cut */ ,
tb->insert_size[0]);
}
/* set right merge flag we take right delimiting key and check whether it is a mergeable item */
if (tb->CFR[0]) {
struct reiserfs_key *key;
key = B_N_PDELIM_KEY(tb->CFR[0], tb->rkey[0]);
if (op_is_left_mergeable(key, Sh->b_size)
&& (vn->vn_mode != M_DELETE
|| vn->vn_affected_item_num != B_NR_ITEMS(Sh) - 1))
vn->vn_vi[vn->vn_nr_item - 1].vi_type |=
VI_TYPE_RIGHT_MERGEABLE;
#ifdef CONFIG_REISERFS_CHECK
if (op_is_left_mergeable(key, Sh->b_size) &&
!(vn->vn_mode != M_DELETE
|| vn->vn_affected_item_num != B_NR_ITEMS(Sh) - 1)) {
/* we delete last item and it could be merged with right neighbor's first item */
if (!
(B_NR_ITEMS(Sh) == 1
&& is_direntry_le_ih(B_N_PITEM_HEAD(Sh, 0))
&& I_ENTRY_COUNT(B_N_PITEM_HEAD(Sh, 0)) == 1)) {
/* node contains more than 1 item, or item is not directory item, or this item contains more than 1 entry */
print_block(Sh, 0, -1, -1);
reiserfs_panic(tb->tb_sb, "vs-8045",
"rdkey %k, affected item==%d "
"(mode==%c) Must be %c",
key, vn->vn_affected_item_num,
vn->vn_mode, M_DELETE);
}
}
#endif
}
}
/* using virtual node check, how many items can be shifted to left
neighbor */
static void check_left(struct tree_balance *tb, int h, int cur_free)
{
int i;
struct virtual_node *vn = tb->tb_vn;
struct virtual_item *vi;
int d_size, ih_size;
RFALSE(cur_free < 0, "vs-8050: cur_free (%d) < 0", cur_free);
/* internal level */
if (h > 0) {
tb->lnum[h] = cur_free / (DC_SIZE + KEY_SIZE);
return;
}
/* leaf level */
if (!cur_free || !vn->vn_nr_item) {
/* no free space or nothing to move */
tb->lnum[h] = 0;
tb->lbytes = -1;
return;
}
RFALSE(!PATH_H_PPARENT(tb->tb_path, 0),
"vs-8055: parent does not exist or invalid");
vi = vn->vn_vi;
if ((unsigned int)cur_free >=
(vn->vn_size -
((vi->vi_type & VI_TYPE_LEFT_MERGEABLE) ? IH_SIZE : 0))) {
/* all contents of S[0] fits into L[0] */
RFALSE(vn->vn_mode == M_INSERT || vn->vn_mode == M_PASTE,
"vs-8055: invalid mode or balance condition failed");
tb->lnum[0] = vn->vn_nr_item;
tb->lbytes = -1;
return;
}
d_size = 0, ih_size = IH_SIZE;
/* first item may be merge with last item in left neighbor */
if (vi->vi_type & VI_TYPE_LEFT_MERGEABLE)
d_size = -((int)IH_SIZE), ih_size = 0;
tb->lnum[0] = 0;
for (i = 0; i < vn->vn_nr_item;
i++, ih_size = IH_SIZE, d_size = 0, vi++) {
d_size += vi->vi_item_len;
if (cur_free >= d_size) {
/* the item can be shifted entirely */
cur_free -= d_size;
tb->lnum[0]++;
continue;
}
/* the item cannot be shifted entirely, try to split it */
/* check whether L[0] can hold ih and at least one byte of the item body */
if (cur_free <= ih_size) {
/* cannot shift even a part of the current item */
tb->lbytes = -1;
return;
}
cur_free -= ih_size;
tb->lbytes = op_check_left(vi, cur_free, 0, 0);
if (tb->lbytes != -1)
/* count partially shifted item */
tb->lnum[0]++;
break;
}
return;
}
/* using virtual node check, how many items can be shifted to right
neighbor */
static void check_right(struct tree_balance *tb, int h, int cur_free)
{
int i;
struct virtual_node *vn = tb->tb_vn;
struct virtual_item *vi;
int d_size, ih_size;
RFALSE(cur_free < 0, "vs-8070: cur_free < 0");
/* internal level */
if (h > 0) {
tb->rnum[h] = cur_free / (DC_SIZE + KEY_SIZE);
return;
}
/* leaf level */
if (!cur_free || !vn->vn_nr_item) {
/* no free space */
tb->rnum[h] = 0;
tb->rbytes = -1;
return;
}
RFALSE(!PATH_H_PPARENT(tb->tb_path, 0),
"vs-8075: parent does not exist or invalid");
vi = vn->vn_vi + vn->vn_nr_item - 1;
if ((unsigned int)cur_free >=
(vn->vn_size -
((vi->vi_type & VI_TYPE_RIGHT_MERGEABLE) ? IH_SIZE : 0))) {
/* all contents of S[0] fits into R[0] */
RFALSE(vn->vn_mode == M_INSERT || vn->vn_mode == M_PASTE,
"vs-8080: invalid mode or balance condition failed");
tb->rnum[h] = vn->vn_nr_item;
tb->rbytes = -1;
return;
}
d_size = 0, ih_size = IH_SIZE;
/* last item may be merge with first item in right neighbor */
if (vi->vi_type & VI_TYPE_RIGHT_MERGEABLE)
d_size = -(int)IH_SIZE, ih_size = 0;
tb->rnum[0] = 0;
for (i = vn->vn_nr_item - 1; i >= 0;
i--, d_size = 0, ih_size = IH_SIZE, vi--) {
d_size += vi->vi_item_len;
if (cur_free >= d_size) {
/* the item can be shifted entirely */
cur_free -= d_size;
tb->rnum[0]++;
continue;
}
/* check whether R[0] can hold ih and at least one byte of the item body */
if (cur_free <= ih_size) { /* cannot shift even a part of the current item */
tb->rbytes = -1;
return;
}
/* R[0] can hold the header of the item and at least one byte of its body */
cur_free -= ih_size; /* cur_free is still > 0 */
tb->rbytes = op_check_right(vi, cur_free);
if (tb->rbytes != -1)
/* count partially shifted item */
tb->rnum[0]++;
break;
}
return;
}
/*
* from - number of items, which are shifted to left neighbor entirely
* to - number of item, which are shifted to right neighbor entirely
* from_bytes - number of bytes of boundary item (or directory entries) which are shifted to left neighbor
* to_bytes - number of bytes of boundary item (or directory entries) which are shifted to right neighbor */
static int get_num_ver(int mode, struct tree_balance *tb, int h,
int from, int from_bytes,
int to, int to_bytes, short *snum012, int flow)
{
int i;
int cur_free;
// int bytes;
int units;
struct virtual_node *vn = tb->tb_vn;
// struct virtual_item * vi;
int total_node_size, max_node_size, current_item_size;
int needed_nodes;
int start_item, /* position of item we start filling node from */
end_item, /* position of item we finish filling node by */
start_bytes, /* number of first bytes (entries for directory) of start_item-th item
we do not include into node that is being filled */
end_bytes; /* number of last bytes (entries for directory) of end_item-th item
we do node include into node that is being filled */
int split_item_positions[2]; /* these are positions in virtual item of
items, that are split between S[0] and
S1new and S1new and S2new */
split_item_positions[0] = -1;
split_item_positions[1] = -1;
/* We only create additional nodes if we are in insert or paste mode
or we are in replace mode at the internal level. If h is 0 and
the mode is M_REPLACE then in fix_nodes we change the mode to
paste or insert before we get here in the code. */
RFALSE(tb->insert_size[h] < 0 || (mode != M_INSERT && mode != M_PASTE),
"vs-8100: insert_size < 0 in overflow");
max_node_size = MAX_CHILD_SIZE(PATH_H_PBUFFER(tb->tb_path, h));
/* snum012 [0-2] - number of items, that lay
to S[0], first new node and second new node */
snum012[3] = -1; /* s1bytes */
snum012[4] = -1; /* s2bytes */
/* internal level */
if (h > 0) {
i = ((to - from) * (KEY_SIZE + DC_SIZE) + DC_SIZE);
if (i == max_node_size)
return 1;
return (i / max_node_size + 1);
}
/* leaf level */
needed_nodes = 1;
total_node_size = 0;
cur_free = max_node_size;
// start from 'from'-th item
start_item = from;
// skip its first 'start_bytes' units
start_bytes = ((from_bytes != -1) ? from_bytes : 0);
// last included item is the 'end_item'-th one
end_item = vn->vn_nr_item - to - 1;
// do not count last 'end_bytes' units of 'end_item'-th item
end_bytes = (to_bytes != -1) ? to_bytes : 0;
/* go through all item beginning from the start_item-th item and ending by
the end_item-th item. Do not count first 'start_bytes' units of
'start_item'-th item and last 'end_bytes' of 'end_item'-th item */
for (i = start_item; i <= end_item; i++) {
struct virtual_item *vi = vn->vn_vi + i;
int skip_from_end = ((i == end_item) ? end_bytes : 0);
RFALSE(needed_nodes > 3, "vs-8105: too many nodes are needed");
/* get size of current item */
current_item_size = vi->vi_item_len;
/* do not take in calculation head part (from_bytes) of from-th item */
current_item_size -=
op_part_size(vi, 0 /*from start */ , start_bytes);
/* do not take in calculation tail part of last item */
current_item_size -=
op_part_size(vi, 1 /*from end */ , skip_from_end);
/* if item fits into current node entierly */
if (total_node_size + current_item_size <= max_node_size) {
snum012[needed_nodes - 1]++;
total_node_size += current_item_size;
start_bytes = 0;
continue;
}
if (current_item_size > max_node_size) {
/* virtual item length is longer, than max size of item in
a node. It is impossible for direct item */
RFALSE(is_direct_le_ih(vi->vi_ih),
"vs-8110: "
"direct item length is %d. It can not be longer than %d",
current_item_size, max_node_size);
/* we will try to split it */
flow = 1;
}
if (!flow) {
/* as we do not split items, take new node and continue */
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);
if (units == -1) {
/* nothing fits into current node, take new node and continue */
needed_nodes++, i--, total_node_size = 0;
continue;
}
}
/* something fits into the current node */
//if (snum012[3] != -1 || needed_nodes != 1)
// reiserfs_panic (tb->tb_sb, "vs-8115: get_num_ver: too many nodes required");
//snum012[needed_nodes - 1 + 3] = op_unit_num (vi) - start_bytes - units;
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;
if (h == 0) { /* only for leaf level */
if (s012 != NULL) {
tb->s0num = *s012++,
tb->s1num = *s012++, tb->s2num = *s012++;
tb->s1bytes = *s012++;
tb->s2bytes = *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, does node disappear 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);
if (remain_items < 1) {
/* all content of node can be shifted to neighbors */
set_parameters(tb, 0, to_left, vn->vn_nr_item - to_left, 0,
NULL, -1, -1);
return 1;
}
if (remain_items > 1 || tb->lbytes == -1 || tb->rbytes == -1)
/* S[0] is not removable */
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 = B_N_PITEM_HEAD(S0, 0);
if (tb->CFR[0]
&& !comp_short_le_keys(&(ih->ih_key),
B_N_PDELIM_KEY(tb->CFR[0],
tb->rkey[0])))
if (is_direntry_le_ih(ih)) {
/* 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 */
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, amount_needed, /* number of needed empty blocks */
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;
}