- 根目录:
- fs
- reiserfs
- do_balan.c
/*
* Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
*/
/*
* Now we have all buffers that must be used in balancing of the tree
* Further calculations can not cause schedule(), and thus the buffer
* tree will be stable until the balancing will be finished
* balance the tree according to the analysis made before,
* and using buffers obtained after all above.
*/
#include <linux/uaccess.h>
#include <linux/time.h>
#include "reiserfs.h"
#include <linux/buffer_head.h>
#include <linux/kernel.h>
static inline void buffer_info_init_left(struct tree_balance *tb,
struct buffer_info *bi)
{
bi->tb = tb;
bi->bi_bh = tb->L[0];
bi->bi_parent = tb->FL[0];
bi->bi_position = get_left_neighbor_position(tb, 0);
}
static inline void buffer_info_init_right(struct tree_balance *tb,
struct buffer_info *bi)
{
bi->tb = tb;
bi->bi_bh = tb->R[0];
bi->bi_parent = tb->FR[0];
bi->bi_position = get_right_neighbor_position(tb, 0);
}
static inline void buffer_info_init_tbS0(struct tree_balance *tb,
struct buffer_info *bi)
{
bi->tb = tb;
bi->bi_bh = PATH_PLAST_BUFFER(tb->tb_path);
bi->bi_parent = PATH_H_PPARENT(tb->tb_path, 0);
bi->bi_position = PATH_H_POSITION(tb->tb_path, 1);
}
static inline void buffer_info_init_bh(struct tree_balance *tb,
struct buffer_info *bi,
struct buffer_head *bh)
{
bi->tb = tb;
bi->bi_bh = bh;
bi->bi_parent = NULL;
bi->bi_position = 0;
}
inline void do_balance_mark_leaf_dirty(struct tree_balance *tb,
struct buffer_head *bh, int flag)
{
journal_mark_dirty(tb->transaction_handle, bh);
}
#define do_balance_mark_internal_dirty do_balance_mark_leaf_dirty
#define do_balance_mark_sb_dirty do_balance_mark_leaf_dirty
/*
* summary:
* if deleting something ( tb->insert_size[0] < 0 )
* return(balance_leaf_when_delete()); (flag d handled here)
* else
* if lnum is larger than 0 we put items into the left node
* if rnum is larger than 0 we put items into the right node
* if snum1 is larger than 0 we put items into the new node s1
* if snum2 is larger than 0 we put items into the new node s2
* Note that all *num* count new items being created.
*/
static void balance_leaf_when_delete_del(struct tree_balance *tb)
{
struct buffer_head *tbS0 = PATH_PLAST_BUFFER(tb->tb_path);
int item_pos = PATH_LAST_POSITION(tb->tb_path);
struct buffer_info bi;
#ifdef CONFIG_REISERFS_CHECK
struct item_head *ih = item_head(tbS0, item_pos);
#endif
RFALSE(ih_item_len(ih) + IH_SIZE != -tb->insert_size[0],
"vs-12013: mode Delete, insert size %d, ih to be deleted %h",
-tb->insert_size[0], ih);
buffer_info_init_tbS0(tb, &bi);
leaf_delete_items(&bi, 0, item_pos, 1, -1);
if (!item_pos && tb->CFL[0]) {
if (B_NR_ITEMS(tbS0)) {
replace_key(tb, tb->CFL[0], tb->lkey[0], tbS0, 0);
} else {
if (!PATH_H_POSITION(tb->tb_path, 1))
replace_key(tb, tb->CFL[0], tb->lkey[0],
PATH_H_PPARENT(tb->tb_path, 0), 0);
}
}
RFALSE(!item_pos && !tb->CFL[0],
"PAP-12020: tb->CFL[0]==%p, tb->L[0]==%p", tb->CFL[0],
tb->L[0]);
}
/* cut item in S[0] */
static void balance_leaf_when_delete_cut(struct tree_balance *tb)
{
struct buffer_head *tbS0 = PATH_PLAST_BUFFER(tb->tb_path);
int item_pos = PATH_LAST_POSITION(tb->tb_path);
struct item_head *ih = item_head(tbS0, item_pos);
int pos_in_item = tb->tb_path->pos_in_item;
struct buffer_info bi;
buffer_info_init_tbS0(tb, &bi);
if (is_direntry_le_ih(ih)) {
/*
* UFS unlink semantics are such that you can only
* delete one directory entry at a time.
*
* when we cut a directory tb->insert_size[0] means
* number of entries to be cut (always 1)
*/
tb->insert_size[0] = -1;
leaf_cut_from_buffer(&bi, item_pos, pos_in_item,
-tb->insert_size[0]);
RFALSE(!item_pos && !pos_in_item && !tb->CFL[0],
"PAP-12030: can not change delimiting key. CFL[0]=%p",
tb->CFL[0]);
if (!item_pos && !pos_in_item && tb->CFL[0])
replace_key(tb, tb->CFL[0], tb->lkey[0], tbS0, 0);
} else {
leaf_cut_from_buffer(&bi, item_pos, pos_in_item,
-tb->insert_size[0]);
RFALSE(!ih_item_len(ih),
"PAP-12035: cut must leave non-zero dynamic "
"length of item");
}
}
static int balance_leaf_when_delete_left(struct tree_balance *tb)
{
struct buffer_head *tbS0 = PATH_PLAST_BUFFER(tb->tb_path);
int n = B_NR_ITEMS(tbS0);
/* L[0] must be joined with S[0] */
if (tb->lnum[0] == -1) {
/* R[0] must be also joined with S[0] */
if (tb->rnum[0] == -1) {
if (tb->FR[0] == PATH_H_PPARENT(tb->tb_path, 0)) {
/*
* all contents of all the
* 3 buffers will be in L[0]
*/
if (PATH_H_POSITION(tb->tb_path, 1) == 0 &&
1 < B_NR_ITEMS(tb->FR[0]))
replace_key(tb, tb->CFL[0],
tb->lkey[0], tb->FR[0], 1);
leaf_move_items(LEAF_FROM_S_TO_L, tb, n, -1,
NULL);
leaf_move_items(LEAF_FROM_R_TO_L, tb,
B_NR_ITEMS(tb->R[0]), -1,
NULL);
reiserfs_invalidate_buffer(tb, tbS0);
reiserfs_invalidate_buffer(tb, tb->R[0]);
return 0;
}
/* all contents of all the 3 buffers will be in R[0] */
leaf_move_items(LEAF_FROM_S_TO_R, tb, n, -1, NULL);
leaf_move_items(LEAF_FROM_L_TO_R, tb,
B_NR_ITEMS(tb->L[0]), -1, NULL);
/* right_delimiting_key is correct in R[0] */
replace_key(tb, tb->CFR[0], tb->rkey[0], tb->R[0], 0);
reiserfs_invalidate_buffer(tb, tbS0);
reiserfs_invalidate_buffer(tb, tb->L[0]);
return -1;
}
RFALSE(tb->rnum[0] != 0,
"PAP-12045: rnum must be 0 (%d)", tb->rnum[0]);
/* all contents of L[0] and S[0] will be in L[0] */
leaf_shift_left(tb, n, -1);
reiserfs_invalidate_buffer(tb, tbS0);
return 0;
}
/*
* a part of contents of S[0] will be in L[0] and
* the rest part of S[0] will be in R[0]
*/
RFALSE((tb->lnum[0] + tb->rnum[0] < n) ||
(tb->lnum[0] + tb->rnum[0] > n + 1),
"PAP-12050: rnum(%d) and lnum(%d) and item "
"number(%d) in S[0] are not consistent",
tb->rnum[0], tb->lnum[0], n);
RFALSE((tb->lnum[0] + tb->rnum[0] == n) &&
(tb->lbytes != -1 || tb->rbytes != -1),
"PAP-12055: bad rbytes (%d)/lbytes (%d) "
"parameters when items are not split",
tb->rbytes, tb->lbytes);
RFALSE((tb->lnum[0] + tb->rnum[0] == n + 1) &&
(tb->lbytes < 1 || tb->rbytes != -1),
"PAP-12060: bad rbytes (%d)/lbytes (%d) "
"parameters when items are split",
tb->rbytes, tb->lbytes);
leaf_shift_left(tb, tb->lnum[0], tb->lbytes);
leaf_shift_right(tb, tb->rnum[0], tb->rbytes);
reiserfs_invalidate_buffer(tb, tbS0);
return 0;
}
/*
* Balance leaf node in case of delete or cut: insert_size[0] < 0
*
* lnum, rnum can have values >= -1
* -1 means that the neighbor must be joined with S
* 0 means that nothing should be done with the neighbor
* >0 means to shift entirely or partly the specified number of items
* to the neighbor
*/
static int balance_leaf_when_delete(struct tree_balance *tb, int flag)
{
struct buffer_head *tbS0 = PATH_PLAST_BUFFER(tb->tb_path);
int item_pos = PATH_LAST_POSITION(tb->tb_path);
struct buffer_info bi;
int n;
struct item_head *ih;
RFALSE(tb->FR[0] && B_LEVEL(tb->FR[0]) != DISK_LEAF_NODE_LEVEL + 1,
"vs- 12000: level: wrong FR %z", tb->FR[0]);
RFALSE(tb->blknum[0] > 1,
"PAP-12005: tb->blknum == %d, can not be > 1", tb->blknum[0]);
RFALSE(!tb->blknum[0] && !PATH_H_PPARENT(tb->tb_path, 0),
"PAP-12010: tree can not be empty");
ih = item_head(tbS0, item_pos);
buffer_info_init_tbS0(tb, &bi);
/* Delete or truncate the item */
BUG_ON(flag != M_DELETE && flag != M_CUT);
if (flag == M_DELETE)
balance_leaf_when_delete_del(tb);
else /* M_CUT */
balance_leaf_when_delete_cut(tb);
/*
* the rule is that no shifting occurs unless by shifting
* a node can be freed
*/
n = B_NR_ITEMS(tbS0);
/* L[0] takes part in balancing */
if (tb->lnum[0])
return balance_leaf_when_delete_left(tb);
if (tb->rnum[0] == -1) {
/* all contents of R[0] and S[0] will be in R[0] */
leaf_shift_right(tb, n, -1);
reiserfs_invalidate_buffer(tb, tbS0);
return 0;
}
RFALSE(tb->rnum[0],
"PAP-12065: bad rnum parameter must be 0 (%d)", tb->rnum[0]);
return 0;
}
static unsigned int balance_leaf_insert_left(struct tree_balance *tb,
struct item_head *const ih,
const char * const body)
{
int ret;
struct buffer_info bi;
int n = B_NR_ITEMS(tb->L[0]);
unsigned body_shift_bytes = 0;
if (tb->item_pos == tb->lnum[0] - 1 && tb->lbytes != -1) {
/* part of new item falls into L[0] */
int new_item_len, shift;
int version;
ret = leaf_shift_left(tb, tb->lnum[0] - 1, -1);
/* Calculate item length to insert to S[0] */
new_item_len = ih_item_len(ih) - tb->lbytes;
/* Calculate and check item length to insert to L[0] */
put_ih_item_len(ih, ih_item_len(ih) - new_item_len);
RFALSE(ih_item_len(ih) <= 0,
"PAP-12080: there is nothing to insert into L[0]: "
"ih_item_len=%d", ih_item_len(ih));
/* Insert new item into L[0] */
buffer_info_init_left(tb, &bi);
leaf_insert_into_buf(&bi, n + tb->item_pos - ret, ih, body,
min_t(int, tb->zeroes_num, ih_item_len(ih)));
version = ih_version(ih);
/*
* Calculate key component, item length and body to
* insert into S[0]
*/
shift = 0;
if (is_indirect_le_ih(ih))
shift = tb->tb_sb->s_blocksize_bits - UNFM_P_SHIFT;
add_le_ih_k_offset(ih, tb->lbytes << shift);
put_ih_item_len(ih, new_item_len);
if (tb->lbytes > tb->zeroes_num) {
body_shift_bytes = tb->lbytes - tb->zeroes_num;
tb->zeroes_num = 0;
} else
tb->zeroes_num -= tb->lbytes;
RFALSE(ih_item_len(ih) <= 0,
"PAP-12085: there is nothing to insert into S[0]: "
"ih_item_len=%d", ih_item_len(ih));
} else {
/* new item in whole falls into L[0] */
/* Shift lnum[0]-1 items to L[0] */
ret = leaf_shift_left(tb, tb->lnum[0] - 1, tb->lbytes);
/* Insert new item into L[0] */
buffer_info_init_left(tb, &bi);
leaf_insert_into_buf(&bi, n + tb->item_pos - ret, ih, body,
tb->zeroes_num);
tb->insert_size[0] = 0;
tb->zeroes_num = 0;
}
return body_shift_bytes;
}
static void balance_leaf_paste_left_shift_dirent(struct tree_balance *tb,
struct item_head * const ih,
const char * const body)
{
int n = B_NR_ITEMS(tb->L[0]);
struct buffer_info bi;
RFALSE(tb->zeroes_num,
"PAP-12090: invalid parameter in case of a directory");
/* directory item */
if (tb->lbytes > tb->pos_in_item) {
/* new directory entry falls into L[0] */
struct item_head *pasted;
int ret, l_pos_in_item = tb->pos_in_item;
/*
* Shift lnum[0] - 1 items in whole.
* Shift lbytes - 1 entries from given directory item
*/
ret = leaf_shift_left(tb, tb->lnum[0], tb->lbytes - 1);
if (ret && !tb->item_pos) {
pasted = item_head(tb->L[0], B_NR_ITEMS(tb->L[0]) - 1);
l_pos_in_item += ih_entry_count(pasted) -
(tb->lbytes - 1);
}
/* Append given directory entry to directory item */
buffer_info_init_left(tb, &bi);
leaf_paste_in_buffer(&bi, n + tb->item_pos - ret,
l_pos_in_item, tb->insert_size[0],
body, tb->zeroes_num);
/*
* previous string prepared space for pasting new entry,
* following string pastes this entry
*/
/*
* when we have merge directory item, pos_in_item
* has been changed too
*/
/* paste new directory entry. 1 is entry number */
leaf_paste_entries(&bi, n + tb->item_pos - ret,
l_pos_in_item, 1,
(struct reiserfs_de_head *) body,
body + DEH_SIZE, tb->insert_size[0]);
tb->insert_size[0] = 0;
} else {
/* new directory item doesn't fall into L[0] */
/*
* Shift lnum[0]-1 items in whole. Shift lbytes
* directory entries from directory item number lnum[0]
*/
leaf_shift_left(tb, tb->lnum[0], tb->lbytes);
}
/* Calculate new position to append in item body */
tb->pos_in_item -= tb->lbytes;
}
static unsigned int balance_leaf_paste_left_shift(struct tree_balance *tb,
struct item_head * const ih,
const char * const body)
{
struct buffer_head *tbS0 = PATH_PLAST_BUFFER(tb->tb_path);
int n = B_NR_ITEMS(tb->L[0]);
struct buffer_info bi;
int body_shift_bytes = 0;
if (is_direntry_le_ih(item_head(tbS0, tb->item_pos))) {
balance_leaf_paste_left_shift_dirent(tb, ih, body);
return 0;
}
RFALSE(tb->lbytes <= 0,
"PAP-12095: there is nothing to shift to L[0]. "
"lbytes=%d", tb->lbytes);
RFALSE(tb->pos_in_item != ih_item_len(item_head(tbS0, tb->item_pos)),
"PAP-12100: incorrect position to paste: "
"item_len=%d, pos_in_item=%d",
ih_item_len(item_head(tbS0, tb->item_pos)), tb->pos_in_item);
/* appended item will be in L[0] in whole */
if (tb->lbytes >= tb->pos_in_item) {
struct item_head *tbS0_pos_ih, *tbL0_ih;
struct item_head *tbS0_0_ih;
struct reiserfs_key *left_delim_key;
int ret, l_n, version, temp_l;
tbS0_pos_ih = item_head(tbS0, tb->item_pos);
tbS0_0_ih = item_head(tbS0, 0);
/*
* this bytes number must be appended
* to the last item of L[h]
*/
l_n = tb->lbytes - tb->pos_in_item;
/* Calculate new insert_size[0] */
tb->insert_size[0] -= l_n;
RFALSE(tb->insert_size[0] <= 0,
"PAP-12105: there is nothing to paste into "
"L[0]. insert_size=%d", tb->insert_size[0]);
ret = leaf_shift_left(tb, tb->lnum[0],
ih_item_len(tbS0_pos_ih));
tbL0_ih = item_head(tb->L[0], n + tb->item_pos - ret);
/* Append to body of item in L[0] */
buffer_info_init_left(tb, &bi);
leaf_paste_in_buffer(&bi, n + tb->item_pos - ret,
ih_item_len(tbL0_ih), l_n, body,
min_t(int, l_n, tb->zeroes_num));
/*
* 0-th item in S0 can be only of DIRECT type
* when l_n != 0
*/
temp_l = l_n;
RFALSE(ih_item_len(tbS0_0_ih),
"PAP-12106: item length must be 0");
RFALSE(comp_short_le_keys(&tbS0_0_ih->ih_key,
leaf_key(tb->L[0], n + tb->item_pos - ret)),
"PAP-12107: items must be of the same file");
if (is_indirect_le_ih(tbL0_ih)) {
int shift = tb->tb_sb->s_blocksize_bits - UNFM_P_SHIFT;
temp_l = l_n << shift;
}
/* update key of first item in S0 */
version = ih_version(tbS0_0_ih);
add_le_key_k_offset(version, &tbS0_0_ih->ih_key, temp_l);
/* update left delimiting key */
left_delim_key = internal_key(tb->CFL[0], tb->lkey[0]);
add_le_key_k_offset(version, left_delim_key, temp_l);
/*
* Calculate new body, position in item and
* insert_size[0]
*/
if (l_n > tb->zeroes_num) {
body_shift_bytes = l_n - tb->zeroes_num;
tb->zeroes_num = 0;
} else
tb->zeroes_num -= l_n;
tb->pos_in_item = 0;
RFALSE(comp_short_le_keys(&tbS0_0_ih->ih_key,
leaf_key(tb->L[0],
B_NR_ITEMS(tb->L[0]) - 1)) ||
!op_is_left_mergeable(leaf_key(tbS0, 0), tbS0->b_size) ||
!op_is_left_mergeable(left_delim_key, tbS0->b_size),
"PAP-12120: item must be merge-able with left "
"neighboring item");
} else {
/* only part of the appended item will be in L[0] */
/* Calculate position in item for append in S[0] */
tb->pos_in_item -= tb->lbytes;
RFALSE(tb->pos_in_item <= 0,
"PAP-12125: no place for paste. pos_in_item=%d",
tb->pos_in_item);
/*
* Shift lnum[0] - 1 items in whole.
* Shift lbytes - 1 byte from item number lnum[0]
*/
leaf_shift_left(tb, tb->lnum[0], tb->lbytes);
}
return body_shift_bytes;
}
/* appended item will be in L[0] in whole */
static void balance_leaf_paste_left_whole(struct tree_balance *tb,
struct item_head * const ih,
const char * const body)
{
struct buffer_head *tbS0 = PATH_PLAST_BUFFER(tb->tb_path);
int n = B_NR_ITEMS(tb->L[0]);
struct buffer_info bi;
struct item_head *pasted;
int ret;
/* if we paste into first item of S[0] and it is left mergable */
if (!tb->item_pos &&
op_is_left_mergeable(leaf_key(tbS0, 0), tbS0->b_size)) {
/*
* then increment pos_in_item by the size of the
* last item in L[0]
*/
pasted = item_head(tb->L[0], n - 1);
if (is_direntry_le_ih(pasted))
tb->pos_in_item += ih_entry_count(pasted);
else
tb->pos_in_item += ih_item_len(pasted);
}
/*
* Shift lnum[0] - 1 items in whole.
* Shift lbytes - 1 byte from item number lnum[0]
*/
ret = leaf_shift_left(tb, tb->lnum[0], tb->lbytes);
/* Append to body of item in L[0] */
buffer_info_init_left(tb, &bi);
leaf_paste_in_buffer(&bi, n + tb->item_pos - ret, tb->pos_in_item,
tb->insert_size[0], body, tb->zeroes_num);
/* if appended item is directory, paste entry */
pasted = item_head(tb->L[0], n + tb->item_pos - ret);
if (is_direntry_le_ih(pasted))
leaf_paste_entries(&bi, n + tb->item_pos - ret,
tb->pos_in_item, 1,
(struct reiserfs_de_head *)body,
body + DEH_SIZE, tb->insert_size[0]);
/*
* if appended item is indirect item, put unformatted node
* into un list
*/
if (is_indirect_le_ih(pasted))
set_ih_free_space(pasted, 0);
tb->insert_size[0] = 0;
tb->zeroes_num = 0;
}
static unsigned int balance_leaf_paste_left(struct tree_balance *tb,
struct item_head * const ih,
const char * const body)
{
/* we must shift the part of the appended item */
if (tb->item_pos == tb->lnum[0] - 1 && tb->lbytes != -1)
return balance_leaf_paste_left_shift(tb, ih, body);
else
balance_leaf_paste_left_whole(tb, ih, body);
return 0;
}
/* Shift lnum[0] items from S[0] to the left neighbor L[0] */
static unsigned int balance_leaf_left(struct tree_balance *tb,
struct item_head * const ih,
const char * const body, int flag)
{
if (tb->lnum[0] <= 0)
return 0;
/* new item or it part falls to L[0], shift it too */
if (tb->item_pos < tb->lnum[0]) {
BUG_ON(flag != M_INSERT && flag != M_PASTE);
if (flag == M_INSERT)
return balance_leaf_insert_left(tb, ih, body);
else /* M_PASTE */
return balance_leaf_paste_left(tb, ih, body);
} else
/* new item doesn't fall into L[0] */
leaf_shift_left(tb, tb->lnum[0], tb->lbytes);
return 0;
}
static void balance_leaf_insert_right(struct tree_balance *tb,
struct item_head * const ih,
const char * const body)
{
struct buffer_head *tbS0 = PATH_PLAST_BUFFER(tb->tb_path);
int n = B_NR_ITEMS(tbS0);
struct buffer_info bi;
int ret;
/* new item or part of it doesn't fall into R[0] */
if (n - tb->rnum[0] >= tb->item_pos) {
leaf_shift_right(tb, tb->rnum[0], tb->rbytes);
return;
}
/* new item or its part falls to R[0] */
/* part of new item falls into R[0] */
if (tb->item_pos == n - tb->rnum[0] + 1 && tb->rbytes != -1) {
loff_t old_key_comp, old_len, r_zeroes_number;
const char *r_body;
int version, shift;
loff_t offset;
leaf_shift_right(tb, tb->rnum[0] - 1, -1);
version = ih_version(ih);
/* Remember key component and item length */
old_key_comp = le_ih_k_offset(ih);
old_len = ih_item_len(ih);
/*
* Calculate key component and item length to insert
* into R[0]
*/
shift = 0;
if (is_indirect_le_ih(ih))
shift = tb->tb_sb->s_blocksize_bits - UNFM_P_SHIFT;
offset = le_ih_k_offset(ih) + ((old_len - tb->rbytes) << shift);
set_le_ih_k_offset(ih, offset);
put_ih_item_len(ih, tb->rbytes);
/* Insert part of the item into R[0] */
buffer_info_init_right(tb, &bi);
if ((old_len - tb->rbytes) > tb->zeroes_num) {
r_zeroes_number = 0;
r_body = body + (old_len - tb->rbytes) - tb->zeroes_num;
} else {
r_body = body;
r_zeroes_number = tb->zeroes_num -
(old_len - tb->rbytes);
tb->zeroes_num -= r_zeroes_number;
}
leaf_insert_into_buf(&bi, 0, ih, r_body, r_zeroes_number);
/* Replace right delimiting key by first key in R[0] */
replace_key(tb, tb->CFR[0], tb->rkey[0], tb->R[0], 0);
/*
* Calculate key component and item length to
* insert into S[0]
*/
set_le_ih_k_offset(ih, old_key_comp);
put_ih_item_len(ih, old_len - tb->rbytes);
tb->insert_size[0] -= tb->rbytes;
} else {
/* whole new item falls into R[0] */
/* Shift rnum[0]-1 items to R[0] */
ret = leaf_shift_right(tb, tb->rnum[0] - 1, tb->rbytes);
/* Insert new item into R[0] */
buffer_info_init_right(tb, &bi);
leaf_insert_into_buf(&bi, tb->item_pos - n + tb->rnum[0] - 1,
ih, body, tb->zeroes_num);
if (tb->item_pos - n + tb->rnum[0] - 1 == 0)
replace_key(tb, tb->CFR[0], tb->rkey[0], tb->R[0], 0);
tb->zeroes_num = tb->insert_size[0] = 0;
}
}
static void balance_leaf_paste_right_shift_dirent(struct tree_balance *tb,
struct item_head * const ih,
const char * const body)
{
struct buffer_head *tbS0 = PATH_PLAST_BUFFER(tb->tb_path);
struct buffer_info bi;
int entry_count;
RFALSE(tb->zeroes_num,
"PAP-12145: invalid parameter in case of a directory");
entry_count = ih_entry_count(item_head(tbS0, tb->item_pos));
/* new directory entry falls into R[0] */
if (entry_count - tb->rbytes < tb->pos_in_item) {
int paste_entry_position;
RFALSE(tb->rbytes - 1 >= entry_count || !tb->insert_size[0],
"PAP-12150: no enough of entries to shift to R[0]: "
"rbytes=%d, entry_count=%d", tb->rbytes, entry_count);
/*
* Shift rnum[0]-1 items in whole.
* Shift rbytes-1 directory entries from directory
* item number rnum[0]
*/
leaf_shift_right(tb, tb->rnum[0], tb->rbytes - 1);
/* Paste given directory entry to directory item */
paste_entry_position = tb->pos_in_item - entry_count +
tb->rbytes - 1;
buffer_info_init_right(tb, &bi);
leaf_paste_in_buffer(&bi, 0, paste_entry_position,
tb->insert_size[0], body, tb->zeroes_num);
/* paste entry */
leaf_paste_entries(&bi, 0, paste_entry_position, 1,
(struct reiserfs_de_head *) body,
body + DEH_SIZE, tb->insert_size[0]);
/* change delimiting keys */
if (paste_entry_position == 0)
replace_key(tb, tb->CFR[0], tb->rkey[0], tb->R[0], 0);
tb->insert_size[0] = 0;
tb->pos_in_item++;
} else {
/* new directory entry doesn't fall into R[0] */
leaf_shift_right(tb, tb->rnum[0], tb->rbytes);
}
}
static void balance_leaf_paste_right_shift(struct tree_balance *tb,
struct item_head * const ih,
const char * const body)
{
struct buffer_head *tbS0 = PATH_PLAST_BUFFER(tb->tb_path);
int n_shift, n_rem, r_zeroes_number, version;
unsigned long temp_rem;
const char *r_body;
struct buffer_info bi;
/* we append to directory item */
if (is_direntry_le_ih(item_head(tbS0, tb->item_pos))) {
balance_leaf_paste_right_shift_dirent(tb, ih, body);
return;
}
/* regular object */
/*
* Calculate number of bytes which must be shifted
* from appended item
*/
n_shift = tb->rbytes - tb->insert_size[0];
if (n_shift < 0)
n_shift = 0;
RFALSE(tb->pos_in_item != ih_item_len(item_head(tbS0, tb->item_pos)),
"PAP-12155: invalid position to paste. ih_item_len=%d, "
"pos_in_item=%d", tb->pos_in_item,
ih_item_len(item_head(tbS0, tb->item_pos)));
leaf_shift_right(tb, tb->rnum[0], n_shift);
/*
* Calculate number of bytes which must remain in body
* after appending to R[0]
*/
n_rem = tb->insert_size[0] - tb->rbytes;
if (n_rem < 0)
n_rem = 0;
temp_rem = n_rem;
version = ih_version(item_head(tb->R[0], 0));
if (is_indirect_le_key(version, leaf_key(tb->R[0], 0))) {
int shift = tb->tb_sb->s_blocksize_bits - UNFM_P_SHIFT;
temp_rem = n_rem << shift;
}
add_le_key_k_offset(version, leaf_key(tb->R[0], 0), temp_rem);
add_le_key_k_offset(version, internal_key(tb->CFR[0], tb->rkey[0]),
temp_rem);
do_balance_mark_internal_dirty(tb, tb->CFR[0], 0);
/* Append part of body into R[0] */
buffer_info_init_right(tb, &bi);
if (n_rem > tb->zeroes_num) {
r_zeroes_number = 0;
r_body = body + n_rem - tb->zeroes_num;
} else {
r_body = body;
r_zeroes_number = tb->zeroes_num - n_rem;
tb->zeroes_num -= r_zeroes_number;
}
leaf_paste_in_buffer(&bi, 0, n_shift, tb->insert_size[0] - n_rem,
r_body, r_zeroes_number);
if (is_indirect_le_ih(item_head(tb->R[0], 0)))
set_ih_free_space(item_head(tb->R[0], 0), 0);
tb->insert_size[0] = n_rem;
if (!n_rem)
tb->pos_in_item++;
}
static void balance_leaf_paste_right_whole(struct tree_balance *tb,
struct item_head * const ih,
const char * const body)
{
struct buffer_head *tbS0 = PATH_PLAST_BUFFER(tb->tb_path);
int n = B_NR_ITEMS(tbS0);
struct item_head *pasted;
struct buffer_info bi;
buffer_info_init_right(tb, &bi);
leaf_shift_right(tb, tb->rnum[0], tb->rbytes);
/* append item in R[0] */
if (tb->pos_in_item >= 0) {
buffer_info_init_right(tb, &bi);
leaf_paste_in_buffer(&bi, tb->item_pos - n + tb->rnum[0],
tb->pos_in_item, tb->insert_size[0], body,
tb->zeroes_num);
}
/* paste new entry, if item is directory item */
pasted = item_head(tb->R[0], tb->item_pos - n + tb->rnum[0]);
if (is_direntry_le_ih(pasted) && tb->pos_in_item >= 0) {
leaf_paste_entries(&bi, tb->item_pos - n + tb->rnum[0],
tb->pos_in_item, 1,
(struct reiserfs_de_head *)body,
body + DEH_SIZE, tb->insert_size[0]);
if (!tb->pos_in_item) {
RFALSE(tb->item_pos - n + tb->rnum[0],
"PAP-12165: directory item must be first "
"item of node when pasting is in 0th position");
/* update delimiting keys */
replace_key(tb, tb->CFR[0], tb->rkey[0], tb->R[0], 0);
}
}
if (is_indirect_le_ih(pasted))
set_ih_free_space(pasted, 0);
tb->zeroes_num = tb->insert_size[0] = 0;
}
static void balance_leaf_paste_right(struct tree_balance *tb,
struct item_head * const ih,
const char * const body)
{
struct buffer_head *tbS0 = PATH_PLAST_BUFFER(tb->tb_path);
int n = B_NR_ITEMS(tbS0);
/* new item doesn't fall into R[0] */
if (n - tb->rnum[0] > tb->item_pos) {
leaf_shift_right(tb, tb->rnum[0], tb->rbytes);
return;
}
/* pasted item or part of it falls to R[0] */
if (tb->item_pos == n - tb->rnum[0] && tb->rbytes != -1)
/* we must shift the part of the appended item */
balance_leaf_paste_right_shift(tb, ih, body);
else
/* pasted item in whole falls into R[0] */
balance_leaf_paste_right_whole(tb, ih, body);
}
/* shift rnum[0] items from S[0] to the right neighbor R[0] */
static void balance_leaf_right(struct tree_balance *tb,
struct item_head * const ih,
const char * const body, int flag)
{
if (tb->rnum[0] <= 0)
return;
BUG_ON(flag != M_INSERT && flag != M_PASTE);
if (flag == M_INSERT)
balance_leaf_insert_right(tb, ih, body);
else /* M_PASTE */
balance_leaf_paste_right(tb, ih, body);
}
static void balance_leaf_new_nodes_insert(struct tree_balance *tb,
struct item_head * const ih,
const char * const body,
struct item_head *insert_key,
struct buffer_head **insert_ptr,
int i)
{
struct buffer_head *tbS0 = PATH_PLAST_BUFFER(tb->tb_path);
int n = B_NR_ITEMS(tbS0);
struct buffer_info bi;
int shift;
/* new item or it part don't falls into S_new[i] */
if (n - tb->snum[i] >= tb->item_pos) {
leaf_move_items(LEAF_FROM_S_TO_SNEW, tb,
tb->snum[i], tb->sbytes[i], tb->S_new[i]);
return;
}
/* new item or it's part falls to first new node S_new[i] */
/* part of new item falls into S_new[i] */
if (tb->item_pos == n - tb->snum[i] + 1 && tb->sbytes[i] != -1) {
int old_key_comp, old_len, r_zeroes_number;
const char *r_body;
int version;
/* Move snum[i]-1 items from S[0] to S_new[i] */
leaf_move_items(LEAF_FROM_S_TO_SNEW, tb, tb->snum[i] - 1, -1,
tb->S_new[i]);
/* Remember key component and item length */
version = ih_version(ih);
old_key_comp = le_ih_k_offset(ih);
old_len = ih_item_len(ih);
/*
* Calculate key component and item length to insert
* into S_new[i]
*/
shift = 0;
if (is_indirect_le_ih(ih))
shift = tb->tb_sb->s_blocksize_bits - UNFM_P_SHIFT;
set_le_ih_k_offset(ih,
le_ih_k_offset(ih) +
((old_len - tb->sbytes[i]) << shift));
put_ih_item_len(ih, tb->sbytes[i]);
/* Insert part of the item into S_new[i] before 0-th item */
buffer_info_init_bh(tb, &bi, tb->S_new[i]);
if ((old_len - tb->sbytes[i]) > tb->zeroes_num) {
r_zeroes_number = 0;
r_body = body + (old_len - tb->sbytes[i]) -
tb->zeroes_num;
} else {
r_body = body;
r_zeroes_number = tb->zeroes_num - (old_len -
tb->sbytes[i]);
tb->zeroes_num -= r_zeroes_number;
}
leaf_insert_into_buf(&bi, 0, ih, r_body, r_zeroes_number);
/*
* Calculate key component and item length to
* insert into S[i]
*/
set_le_ih_k_offset(ih, old_key_comp);
put_ih_item_len(ih, old_len - tb->sbytes[i]);
tb->insert_size[0] -= tb->sbytes[i];
} else {
/* whole new item falls into S_new[i] */
/*
* Shift snum[0] - 1 items to S_new[i]
* (sbytes[i] of split item)
*/
leaf_move_items(LEAF_FROM_S_TO_SNEW, tb,
tb->snum[i] - 1, tb->sbytes[i], tb->S_new[i]);
/* Insert new item into S_new[i] */
buffer_info_init_bh(tb, &bi, tb->S_new[i]);
leaf_insert_into_buf(&bi, tb->item_pos - n + tb->snum[i] - 1,
ih, body, tb->zeroes_num);
tb->zeroes_num = tb->insert_size[0] = 0;
}
}
/* we append to directory item */
static void balance_leaf_new_nodes_paste_dirent(struct tree_balance *tb,
struct item_head * const ih,
const char * const body,
struct item_head *insert_key,
struct buffer_head **insert_ptr,
int i)
{
struct buffer_head *tbS0 = PATH_PLAST_BUFFER(tb->tb_path);
struct item_head *aux_ih = item_head(tbS0, tb->item_pos);
int entry_count = ih_entry_count(aux_ih);
struct buffer_info bi;
if (entry_count - tb->sbytes[i] < tb->pos_in_item &&
tb->pos_in_item <= entry_count) {
/* new directory entry falls into S_new[i] */
RFALSE(!tb->insert_size[0],
"PAP-12215: insert_size is already 0");
RFALSE(tb->sbytes[i] - 1 >= entry_count,
"PAP-12220: there are no so much entries (%d), only %d",
tb->sbytes[i] - 1, entry_count);
/*
* Shift snum[i]-1 items in whole.
* Shift sbytes[i] directory entries
* from directory item number snum[i]
*/
leaf_move_items(LEAF_FROM_S_TO_SNEW, tb, tb->snum[i],
tb->sbytes[i] - 1, tb->S_new[i]);
/*
* Paste given directory entry to
* directory item
*/
buffer_info_init_bh(tb, &bi, tb->S_new[i]);
leaf_paste_in_buffer(&bi, 0, tb->pos_in_item - entry_count +
tb->sbytes[i] - 1, tb->insert_size[0],
body, tb->zeroes_num);
/* paste new directory entry */
leaf_paste_entries(&bi, 0, tb->pos_in_item - entry_count +
tb->sbytes[i] - 1, 1,
(struct reiserfs_de_head *) body,
body + DEH_SIZE, tb->insert_size[0]);
tb->insert_size[0] = 0;
tb->pos_in_item++;
} else {
/* new directory entry doesn't fall into S_new[i] */
leaf_move_items(LEAF_FROM_S_TO_SNEW, tb, tb->snum[i],
tb->sbytes[i], tb->S_new[i]);
}
}
static void balance_leaf_new_nodes_paste_shift(struct tree_balance *tb,
struct item_head * const ih,
const char * const body,
struct item_head *insert_key,
struct buffer_head **insert_ptr,
int i)
{
struct buffer_head *tbS0 = PATH_PLAST_BUFFER(tb->tb_path);
struct item_head *aux_ih = item_head(tbS0, tb->item_pos);
int n_shift, n_rem, r_zeroes_number, shift;
const char *r_body;
struct item_head *tmp;
struct buffer_info bi;
RFALSE(ih, "PAP-12210: ih must be 0");
if (is_direntry_le_ih(aux_ih)) {
balance_leaf_new_nodes_paste_dirent(tb, ih, body, insert_key,
insert_ptr, i);
return;
}
/* regular object */
RFALSE(tb->pos_in_item != ih_item_len(item_head(tbS0, tb->item_pos)) ||
tb->insert_size[0] <= 0,
"PAP-12225: item too short or insert_size <= 0");
/*
* Calculate number of bytes which must be shifted from appended item
*/
n_shift = tb->sbytes[i] - tb->insert_size[0];
if (n_shift < 0)
n_shift = 0;
leaf_move_items(LEAF_FROM_S_TO_SNEW, tb, tb->snum[i], n_shift,
tb->S_new[i]);
/*
* Calculate number of bytes which must remain in body after
* append to S_new[i]
*/
n_rem = tb->insert_size[0] - tb->sbytes[i];
if (n_rem < 0)
n_rem = 0;
/* Append part of body into S_new[0] */
buffer_info_init_bh(tb, &bi, tb->S_new[i]);
if (n_rem > tb->zeroes_num) {
r_zeroes_number = 0;
r_body = body + n_rem - tb->zeroes_num;
} else {
r_body = body;
r_zeroes_number = tb->zeroes_num - n_rem;
tb->zeroes_num -= r_zeroes_number;
}
leaf_paste_in_buffer(&bi, 0, n_shift, tb->insert_size[0] - n_rem,
r_body, r_zeroes_number);
tmp = item_head(tb->S_new[i], 0);
shift = 0;
if (is_indirect_le_ih(tmp)) {
set_ih_free_space(tmp, 0);
shift = tb->tb_sb->s_blocksize_bits - UNFM_P_SHIFT;
}
add_le_ih_k_offset(tmp, n_rem << shift);
tb->insert_size[0] = n_rem;
if (!n_rem)
tb->pos_in_item++;
}
static void balance_leaf_new_nodes_paste_whole(struct tree_balance *tb,
struct item_head * const ih,
const char * const body,
struct item_head *insert_key,
struct buffer_head **insert_ptr,
int i)
{
struct buffer_head *tbS0 = PATH_PLAST_BUFFER(tb->tb_path);
int n = B_NR_ITEMS(tbS0);
int leaf_mi;
struct item_head *pasted;
struct buffer_info bi;
#ifdef CONFIG_REISERFS_CHECK
struct item_head *ih_check = item_head(tbS0, tb->item_pos);
if (!is_direntry_le_ih(ih_check) &&
(tb->pos_in_item != ih_item_len(ih_check) ||
tb->insert_size[0] <= 0))
reiserfs_panic(tb->tb_sb,
"PAP-12235",
"pos_in_item must be equal to ih_item_len");
#endif
leaf_mi = leaf_move_items(LEAF_FROM_S_TO_SNEW, tb, tb->snum[i],
tb->sbytes[i], tb->S_new[i]);
RFALSE(leaf_mi,
"PAP-12240: unexpected value returned by leaf_move_items (%d)",
leaf_mi);
/* paste into item */
buffer_info_init_bh(tb, &bi, tb->S_new[i]);
leaf_paste_in_buffer(&bi, tb->item_pos - n + tb->snum[i],
tb->pos_in_item, tb->insert_size[0],
body, tb->zeroes_num);
pasted = item_head(tb->S_new[i], tb->item_pos - n +
tb->snum[i]);
if (is_direntry_le_ih(pasted))
leaf_paste_entries(&bi, tb->item_pos - n + tb->snum[i],
tb->pos_in_item, 1,
(struct reiserfs_de_head *)body,
body + DEH_SIZE, tb->insert_size[0]);
/* if we paste to indirect item update ih_free_space */
if (is_indirect_le_ih(pasted))
set_ih_free_space(pasted, 0);
tb->zeroes_num = tb->insert_size[0] = 0;
}
static void balance_leaf_new_nodes_paste(struct tree_balance *tb,
struct item_head * const ih,
const char * const body,
struct item_head *insert_key,
struct buffer_head **insert_ptr,
int i)
{
struct buffer_head *tbS0 = PATH_PLAST_BUFFER(tb->tb_path);
int n = B_NR_ITEMS(tbS0);
/* pasted item doesn't fall into S_new[i] */
if (n - tb->snum[i] > tb->item_pos) {
leaf_move_items(LEAF_FROM_S_TO_SNEW, tb,
tb->snum[i], tb->sbytes[i], tb->S_new[i]);
return;
}
/* pasted item or part if it falls to S_new[i] */
if (tb->item_pos == n - tb->snum[i] && tb->sbytes[i] != -1)
/* we must shift part of the appended item */
balance_leaf_new_nodes_paste_shift(tb, ih, body, insert_key,
insert_ptr, i);
else
/* item falls wholly into S_new[i] */
balance_leaf_new_nodes_paste_whole(tb, ih, body, insert_key,
insert_ptr, i);
}
/* Fill new nodes that appear in place of S[0] */
static void balance_leaf_new_nodes(struct tree_balance *tb,
struct item_head * const ih,
const char * const body,
struct item_head *insert_key,
struct buffer_head **insert_ptr,
int flag)
{
int i;
for (i = tb->blknum[0] - 2; i >= 0; i--) {
BUG_ON(flag != M_INSERT && flag != M_PASTE);
RFALSE(!tb->snum[i],
"PAP-12200: snum[%d] == %d. Must be > 0", i,
tb->snum[i]);
/* here we shift from S to S_new nodes */
tb->S_new[i] = get_FEB(tb);
/* initialized block type and tree level */
set_blkh_level(B_BLK_HEAD(tb->S_new[i]), DISK_LEAF_NODE_LEVEL);
if (flag == M_INSERT)
balance_leaf_new_nodes_insert(tb, ih, body, insert_key,
insert_ptr, i);
else /* M_PASTE */
balance_leaf_new_nodes_paste(tb, ih, body, insert_key,
insert_ptr, i);
memcpy(insert_key + i, leaf_key(tb->S_new[i], 0), KEY_SIZE);
insert_ptr[i] = tb->S_new[i];
RFALSE(!buffer_journaled(tb->S_new[i])
|| buffer_journal_dirty(tb->S_new[i])
|| buffer_dirty(tb->S_new[i]),
"PAP-12247: S_new[%d] : (%b)",
i, tb->S_new[i]);
}
}
static void balance_leaf_finish_node_insert(struct tree_balance *tb,
struct item_head * const ih,
const char * const body)
{
struct buffer_head *tbS0 = PATH_PLAST_BUFFER(tb->tb_path);
struct buffer_info bi;
buffer_info_init_tbS0(tb, &bi);
leaf_insert_into_buf(&bi, tb->item_pos, ih, body, tb->zeroes_num);
/* If we insert the first key change the delimiting key */
if (tb->item_pos == 0) {
if (tb->CFL[0]) /* can be 0 in reiserfsck */
replace_key(tb, tb->CFL[0], tb->lkey[0], tbS0, 0);
}
}
static void balance_leaf_finish_node_paste_dirent(struct tree_balance *tb,
struct item_head * const ih,
const char * const body)
{
struct buffer_head *tbS0 = PATH_PLAST_BUFFER(tb->tb_path);
struct item_head *pasted = item_head(tbS0, tb->item_pos);
struct buffer_info bi;
if (tb->pos_in_item >= 0 && tb->pos_in_item <= ih_entry_count(pasted)) {
RFALSE(!tb->insert_size[0],
"PAP-12260: insert_size is 0 already");
/* prepare space */
buffer_info_init_tbS0(tb, &bi);
leaf_paste_in_buffer(&bi, tb->item_pos, tb->pos_in_item,
tb->insert_size[0], body, tb->zeroes_num);
/* paste entry */
leaf_paste_entries(&bi, tb->item_pos, tb->pos_in_item, 1,
(struct reiserfs_de_head *)body,
body + DEH_SIZE, tb->insert_size[0]);
if (!tb->item_pos && !tb->pos_in_item) {
RFALSE(!tb->CFL[0] || !tb->L[0],
"PAP-12270: CFL[0]/L[0] must be specified");
if (tb->CFL[0])
replace_key(tb, tb->CFL[0], tb->lkey[0],
tbS0, 0);
}
tb->insert_size[0] = 0;
}
}
static void balance_leaf_finish_node_paste(struct tree_balance *tb,
struct item_head * const ih,
const char * const body)
{
struct buffer_head *tbS0 = PATH_PLAST_BUFFER(tb->tb_path);
struct buffer_info bi;
struct item_head *pasted = item_head(tbS0, tb->item_pos);
/* when directory, may be new entry already pasted */
if (is_direntry_le_ih(pasted)) {
balance_leaf_finish_node_paste_dirent(tb, ih, body);
return;
}
/* regular object */
if (tb->pos_in_item == ih_item_len(pasted)) {
RFALSE(tb->insert_size[0] <= 0,
"PAP-12275: insert size must not be %d",
tb->insert_size[0]);
buffer_info_init_tbS0(tb, &bi);
leaf_paste_in_buffer(&bi, tb->item_pos,
tb->pos_in_item, tb->insert_size[0], body,
tb->zeroes_num);
if (is_indirect_le_ih(pasted))
set_ih_free_space(pasted, 0);
tb->insert_size[0] = 0;
}
#ifdef CONFIG_REISERFS_CHECK
else if (tb->insert_size[0]) {
print_cur_tb("12285");
reiserfs_panic(tb->tb_sb, "PAP-12285",
"insert_size must be 0 (%d)", tb->insert_size[0]);
}
#endif
}
/*
* if the affected item was not wholly shifted then we
* perform all necessary operations on that part or whole
* of the affected item which remains in S
*/
static void balance_leaf_finish_node(struct tree_balance *tb,
struct item_head * const ih,
const char * const body, int flag)
{
/* if we must insert or append into buffer S[0] */
if (0 <= tb->item_pos && tb->item_pos < tb->s0num) {
if (flag == M_INSERT)
balance_leaf_finish_node_insert(tb, ih, body);
else /* M_PASTE */
balance_leaf_finish_node_paste(tb, ih, body);
}
}
/**
* balance_leaf - reiserfs tree balancing algorithm
* @tb: tree balance state
* @ih: item header of inserted item (little endian)
* @body: body of inserted item or bytes to paste
* @flag: i - insert, d - delete, c - cut, p - paste (see do_balance)
* passed back:
* @insert_key: key to insert new nodes
* @insert_ptr: array of nodes to insert at the next level
*
* In our processing of one level we sometimes determine what must be
* inserted into the next higher level. This insertion consists of a
* key or two keys and their corresponding pointers.
*/
static int balance_leaf(struct tree_balance *tb, struct item_head *ih,
const char *body, int flag,
struct item_head *insert_key,
struct buffer_head **insert_ptr)
{
struct buffer_head *tbS0 = PATH_PLAST_BUFFER(tb->tb_path);
PROC_INFO_INC(tb->tb_sb, balance_at[0]);
/* Make balance in case insert_size[0] < 0 */
if (tb->insert_size[0] < 0)
return balance_leaf_when_delete(tb, flag);
tb->item_pos = PATH_LAST_POSITION(tb->tb_path),
tb->pos_in_item = tb->tb_path->pos_in_item,
tb->zeroes_num = 0;
if (flag == M_INSERT && !body)
tb->zeroes_num = ih_item_len(ih);
/*
* for indirect item pos_in_item is measured in unformatted node
* pointers. Recalculate to bytes
*/
if (flag != M_INSERT
&& is_indirect_le_ih(item_head(tbS0, tb->item_pos)))
tb->pos_in_item *= UNFM_P_SIZE;
body += balance_leaf_left(tb, ih, body, flag);
/* tb->lnum[0] > 0 */
/* Calculate new item position */
tb->item_pos -= (tb->lnum[0] - ((tb->lbytes != -1) ? 1 : 0));
balance_leaf_right(tb, ih, body, flag);
/* tb->rnum[0] > 0 */
RFALSE(tb->blknum[0] > 3,
"PAP-12180: blknum can not be %d. It must be <= 3", tb->blknum[0]);
RFALSE(tb->blknum[0] < 0,
"PAP-12185: blknum can not be %d. It must be >= 0", tb->blknum[0]);
/*
* if while adding to a node we discover that it is possible to split
* it in two, and merge the left part into the left neighbor and the
* right part into the right neighbor, eliminating the node
*/
if (tb->blknum[0] == 0) { /* node S[0] is empty now */
RFALSE(!tb->lnum[0] || !tb->rnum[0],
"PAP-12190: lnum and rnum must not be zero");
/*
* if insertion was done before 0-th position in R[0], right
* delimiting key of the tb->L[0]'s and left delimiting key are
* not set correctly
*/
if (tb->CFL[0]) {
if (!tb->CFR[0])
reiserfs_panic(tb->tb_sb, "vs-12195",
"CFR not initialized");
copy_key(internal_key(tb->CFL[0], tb->lkey[0]),
internal_key(tb->CFR[0], tb->rkey[0]));
do_balance_mark_internal_dirty(tb, tb->CFL[0], 0);
}
reiserfs_invalidate_buffer(tb, tbS0);
return 0;
}
balance_leaf_new_nodes(tb, ih, body, insert_key, insert_ptr, flag);
balance_leaf_finish_node(tb, ih, body, flag);
#ifdef CONFIG_REISERFS_CHECK
if (flag == M_PASTE && tb->insert_size[0]) {
print_cur_tb("12290");
reiserfs_panic(tb->tb_sb,
"PAP-12290", "insert_size is still not 0 (%d)",
tb->insert_size[0]);
}
#endif
/* Leaf level of the tree is balanced (end of balance_leaf) */
return 0;
}
/* Make empty node */
void make_empty_node(struct buffer_info *bi)
{
struct block_head *blkh;
RFALSE(bi->bi_bh == NULL, "PAP-12295: pointer to the buffer is NULL");
blkh = B_BLK_HEAD(bi->bi_bh);
set_blkh_nr_item(blkh, 0);
set_blkh_free_space(blkh, MAX_CHILD_SIZE(bi->bi_bh));
if (bi->bi_parent)
B_N_CHILD(bi->bi_parent, bi->bi_position)->dc_size = 0; /* Endian safe if 0 */
}
/* Get first empty buffer */
struct buffer_head *get_FEB(struct tree_balance *tb)
{
int i;
struct buffer_info bi;
for (i = 0; i < MAX_FEB_SIZE; i++)
if (tb->FEB[i] != NULL)
break;
if (i == MAX_FEB_SIZE)
reiserfs_panic(tb->tb_sb, "vs-12300", "FEB list is empty");
buffer_info_init_bh(tb, &bi, tb->FEB[i]);
make_empty_node(&bi);
set_buffer_uptodate(tb->FEB[i]);
tb->used[i] = tb->FEB[i];
tb->FEB[i] = NULL;
return tb->used[i];
}
/* This is now used because reiserfs_free_block has to be able to schedule. */
static void store_thrown(struct tree_balance *tb, struct buffer_head *bh)
{
int i;
if (buffer_dirty(bh))
reiserfs_warning(tb->tb_sb, "reiserfs-12320",
"called with dirty buffer");
for (i = 0; i < ARRAY_SIZE(tb->thrown); i++)
if (!tb->thrown[i]) {
tb->thrown[i] = bh;
get_bh(bh); /* free_thrown puts this */
return;
}
reiserfs_warning(tb->tb_sb, "reiserfs-12321",
"too many thrown buffers");
}
static void free_thrown(struct tree_balance *tb)
{
int i;
b_blocknr_t blocknr;
for (i = 0; i < ARRAY_SIZE(tb->thrown); i++) {
if (tb->thrown[i]) {
blocknr = tb->thrown[i]->b_blocknr;
if (buffer_dirty(tb->thrown[i]))
reiserfs_warning(tb->tb_sb, "reiserfs-12322",
"called with dirty buffer %d",
blocknr);
brelse(tb->thrown[i]); /* incremented in store_thrown */
reiserfs_free_block(tb->transaction_handle, NULL,
blocknr, 0);
}
}
}
void reiserfs_invalidate_buffer(struct tree_balance *tb, struct buffer_head *bh)
{
struct block_head *blkh;
blkh = B_BLK_HEAD(bh);
set_blkh_level(blkh, FREE_LEVEL);
set_blkh_nr_item(blkh, 0);
clear_buffer_dirty(bh);
store_thrown(tb, bh);
}
/* Replace n_dest'th key in buffer dest by n_src'th key of buffer src.*/
void replace_key(struct tree_balance *tb, struct buffer_head *dest, int n_dest,
struct buffer_head *src, int n_src)
{
RFALSE(dest == NULL || src == NULL,
"vs-12305: source or destination buffer is 0 (src=%p, dest=%p)",
src, dest);
RFALSE(!B_IS_KEYS_LEVEL(dest),
"vs-12310: invalid level (%z) for destination buffer. dest must be leaf",
dest);
RFALSE(n_dest < 0 || n_src < 0,
"vs-12315: src(%d) or dest(%d) key number < 0", n_src, n_dest);
RFALSE(n_dest >= B_NR_ITEMS(dest) || n_src >= B_NR_ITEMS(src),
"vs-12320: src(%d(%d)) or dest(%d(%d)) key number is too big",
n_src, B_NR_ITEMS(src), n_dest, B_NR_ITEMS(dest));
if (B_IS_ITEMS_LEVEL(src))
/* source buffer contains leaf node */
memcpy(internal_key(dest, n_dest), item_head(src, n_src),
KEY_SIZE);
else
memcpy(internal_key(dest, n_dest), internal_key(src, n_src),
KEY_SIZE);
do_balance_mark_internal_dirty(tb, dest, 0);
}
int get_left_neighbor_position(struct tree_balance *tb, int h)
{
int Sh_position = PATH_H_POSITION(tb->tb_path, h + 1);
RFALSE(PATH_H_PPARENT(tb->tb_path, h) == NULL || tb->FL[h] == NULL,
"vs-12325: FL[%d](%p) or F[%d](%p) does not exist",
h, tb->FL[h], h, PATH_H_PPARENT(tb->tb_path, h));
if (Sh_position == 0)
return B_NR_ITEMS(tb->FL[h]);
else
return Sh_position - 1;
}
int get_right_neighbor_position(struct tree_balance *tb, int h)
{
int Sh_position = PATH_H_POSITION(tb->tb_path, h + 1);
RFALSE(PATH_H_PPARENT(tb->tb_path, h) == NULL || tb->FR[h] == NULL,
"vs-12330: F[%d](%p) or FR[%d](%p) does not exist",
h, PATH_H_PPARENT(tb->tb_path, h), h, tb->FR[h]);
if (Sh_position == B_NR_ITEMS(PATH_H_PPARENT(tb->tb_path, h)))
return 0;
else
return Sh_position + 1;
}
#ifdef CONFIG_REISERFS_CHECK
int is_reusable(struct super_block *s, b_blocknr_t block, int bit_value);
static void check_internal_node(struct super_block *s, struct buffer_head *bh,
char *mes)
{
struct disk_child *dc;
int i;
RFALSE(!bh, "PAP-12336: bh == 0");
if (!bh || !B_IS_IN_TREE(bh))
return;
RFALSE(!buffer_dirty(bh) &&
!(buffer_journaled(bh) || buffer_journal_dirty(bh)),
"PAP-12337: buffer (%b) must be dirty", bh);
dc = B_N_CHILD(bh, 0);
for (i = 0; i <= B_NR_ITEMS(bh); i++, dc++) {
if (!is_reusable(s, dc_block_number(dc), 1)) {
print_cur_tb(mes);
reiserfs_panic(s, "PAP-12338",
"invalid child pointer %y in %b",
dc, bh);
}
}
}
static int locked_or_not_in_tree(struct tree_balance *tb,
struct buffer_head *bh, char *which)
{
if ((!buffer_journal_prepared(bh) && buffer_locked(bh)) ||
!B_IS_IN_TREE(bh)) {
reiserfs_warning(tb->tb_sb, "vs-12339", "%s (%b)", which, bh);
return 1;
}
return 0;
}
static int check_before_balancing(struct tree_balance *tb)
{
int retval = 0;
if (REISERFS_SB(tb->tb_sb)->cur_tb) {
reiserfs_panic(tb->tb_sb, "vs-12335", "suspect that schedule "
"occurred based on cur_tb not being null at "
"this point in code. do_balance cannot properly "
"handle concurrent tree accesses on a same "
"mount point.");
}
/*
* double check that buffers that we will modify are unlocked.
* (fix_nodes should already have prepped all of these for us).
*/
if (tb->lnum[0]) {
retval |= locked_or_not_in_tree(tb, tb->L[0], "L[0]");
retval |= locked_or_not_in_tree(tb, tb->FL[0], "FL[0]");
retval |= locked_or_not_in_tree(tb, tb->CFL[0], "CFL[0]");
check_leaf(tb->L[0]);
}
if (tb->rnum[0]) {
retval |= locked_or_not_in_tree(tb, tb->R[0], "R[0]");
retval |= locked_or_not_in_tree(tb, tb->FR[0], "FR[0]");
retval |= locked_or_not_in_tree(tb, tb->CFR[0], "CFR[0]");
check_leaf(tb->R[0]);
}
retval |= locked_or_not_in_tree(tb, PATH_PLAST_BUFFER(tb->tb_path),
"S[0]");
check_leaf(PATH_PLAST_BUFFER(tb->tb_path));
return retval;
}
static void check_after_balance_leaf(struct tree_balance *tb)
{
if (tb->lnum[0]) {
if (B_FREE_SPACE(tb->L[0]) !=
MAX_CHILD_SIZE(tb->L[0]) -
dc_size(B_N_CHILD
(tb->FL[0], get_left_neighbor_position(tb, 0)))) {
print_cur_tb("12221");
reiserfs_panic(tb->tb_sb, "PAP-12355",
"shift to left was incorrect");
}
}
if (tb->rnum[0]) {
if (B_FREE_SPACE(tb->R[0]) !=
MAX_CHILD_SIZE(tb->R[0]) -
dc_size(B_N_CHILD
(tb->FR[0], get_right_neighbor_position(tb, 0)))) {
print_cur_tb("12222");
reiserfs_panic(tb->tb_sb, "PAP-12360",
"shift to right was incorrect");
}
}
if (PATH_H_PBUFFER(tb->tb_path, 1) &&
(B_FREE_SPACE(PATH_H_PBUFFER(tb->tb_path, 0)) !=
(MAX_CHILD_SIZE(PATH_H_PBUFFER(tb->tb_path, 0)) -
dc_size(B_N_CHILD(PATH_H_PBUFFER(tb->tb_path, 1),
PATH_H_POSITION(tb->tb_path, 1)))))) {
int left = B_FREE_SPACE(PATH_H_PBUFFER(tb->tb_path, 0));
int right = (MAX_CHILD_SIZE(PATH_H_PBUFFER(tb->tb_path, 0)) -
dc_size(B_N_CHILD(PATH_H_PBUFFER(tb->tb_path, 1),
PATH_H_POSITION(tb->tb_path,
1))));
print_cur_tb("12223");
reiserfs_warning(tb->tb_sb, "reiserfs-12363",
"B_FREE_SPACE (PATH_H_PBUFFER(tb->tb_path,0)) = %d; "
"MAX_CHILD_SIZE (%d) - dc_size( %y, %d ) [%d] = %d",
left,
MAX_CHILD_SIZE(PATH_H_PBUFFER(tb->tb_path, 0)),
PATH_H_PBUFFER(tb->tb_path, 1),
PATH_H_POSITION(tb->tb_path, 1),
dc_size(B_N_CHILD
(PATH_H_PBUFFER(tb->tb_path, 1),
PATH_H_POSITION(tb->tb_path, 1))),
right);
reiserfs_panic(tb->tb_sb, "PAP-12365", "S is incorrect");
}
}
static void check_leaf_level(struct tree_balance *tb)
{
check_leaf(tb->L[0]);
check_leaf(tb->R[0]);
check_leaf(PATH_PLAST_BUFFER(tb->tb_path));
}
static void check_internal_levels(struct tree_balance *tb)
{
int h;
/* check all internal nodes */
for (h = 1; tb->insert_size[h]; h++) {
check_internal_node(tb->tb_sb, PATH_H_PBUFFER(tb->tb_path, h),
"BAD BUFFER ON PATH");
if (tb->lnum[h])
check_internal_node(tb->tb_sb, tb->L[h], "BAD L");
if (tb->rnum[h])
check_internal_node(tb->tb_sb, tb->R[h], "BAD R");
}
}
#endif
/*
* Now we have all of the buffers that must be used in balancing of
* the tree. We rely on the assumption that schedule() will not occur
* while do_balance works. ( Only interrupt handlers are acceptable.)
* We balance the tree according to the analysis made before this,
* using buffers already obtained. For SMP support it will someday be
* necessary to add ordered locking of tb.
*/
/*
* Some interesting rules of balancing:
* we delete a maximum of two nodes per level per balancing: we never
* delete R, when we delete two of three nodes L, S, R then we move
* them into R.
*
* we only delete L if we are deleting two nodes, if we delete only
* one node we delete S
*
* if we shift leaves then we shift as much as we can: this is a
* deliberate policy of extremism in node packing which results in
* higher average utilization after repeated random balance operations
* at the cost of more memory copies and more balancing as a result of
* small insertions to full nodes.
*
* if we shift internal nodes we try to evenly balance the node
* utilization, with consequent less balancing at the cost of lower
* utilization.
*
* one could argue that the policy for directories in leaves should be
* that of internal nodes, but we will wait until another day to
* evaluate this.... It would be nice to someday measure and prove
* these assumptions as to what is optimal....
*/
static inline void do_balance_starts(struct tree_balance *tb)
{
/* use print_cur_tb() to see initial state of struct tree_balance */
/* store_print_tb (tb); */
/* do not delete, just comment it out */
/*
print_tb(flag, PATH_LAST_POSITION(tb->tb_path),
tb->tb_path->pos_in_item, tb, "check");
*/
RFALSE(check_before_balancing(tb), "PAP-12340: locked buffers in TB");
#ifdef CONFIG_REISERFS_CHECK
REISERFS_SB(tb->tb_sb)->cur_tb = tb;
#endif
}
static inline void do_balance_completed(struct tree_balance *tb)
{
#ifdef CONFIG_REISERFS_CHECK
check_leaf_level(tb);
check_internal_levels(tb);
REISERFS_SB(tb->tb_sb)->cur_tb = NULL;
#endif
/*
* reiserfs_free_block is no longer schedule safe. So, we need to
* put the buffers we want freed on the thrown list during do_balance,
* and then free them now
*/
REISERFS_SB(tb->tb_sb)->s_do_balance++;
/* release all nodes hold to perform the balancing */
unfix_nodes(tb);
free_thrown(tb);
}
/*
* do_balance - balance the tree
*
* @tb: tree_balance structure
* @ih: item header of inserted item
* @body: body of inserted item or bytes to paste
* @flag: 'i' - insert, 'd' - delete, 'c' - cut, 'p' paste
*
* Cut means delete part of an item (includes removing an entry from a
* directory).
*
* Delete means delete whole item.
*
* Insert means add a new item into the tree.
*
* Paste means to append to the end of an existing file or to
* insert a directory entry.
*/
void do_balance(struct tree_balance *tb, struct item_head *ih,
const char *body, int flag)
{
int child_pos; /* position of a child node in its parent */
int h; /* level of the tree being processed */
/*
* in our processing of one level we sometimes determine what
* must be inserted into the next higher level. This insertion
* consists of a key or two keys and their corresponding
* pointers
*/
struct item_head insert_key[2];
/* inserted node-ptrs for the next level */
struct buffer_head *insert_ptr[2];
tb->tb_mode = flag;
tb->need_balance_dirty = 0;
if (FILESYSTEM_CHANGED_TB(tb)) {
reiserfs_panic(tb->tb_sb, "clm-6000", "fs generation has "
"changed");
}
/* if we have no real work to do */
if (!tb->insert_size[0]) {
reiserfs_warning(tb->tb_sb, "PAP-12350",
"insert_size == 0, mode == %c", flag);
unfix_nodes(tb);
return;
}
atomic_inc(&fs_generation(tb->tb_sb));
do_balance_starts(tb);
/*
* balance_leaf returns 0 except if combining L R and S into
* one node. see balance_internal() for explanation of this
* line of code.
*/
child_pos = PATH_H_B_ITEM_ORDER(tb->tb_path, 0) +
balance_leaf(tb, ih, body, flag, insert_key, insert_ptr);
#ifdef CONFIG_REISERFS_CHECK
check_after_balance_leaf(tb);
#endif
/* Balance internal level of the tree. */
for (h = 1; h < MAX_HEIGHT && tb->insert_size[h]; h++)
child_pos = balance_internal(tb, h, child_pos, insert_key,
insert_ptr);
do_balance_completed(tb);
}