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lbalance.c
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lbalance.c
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/*
* Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
*/
#include <linux/uaccess.h>
#include <linux/string.h>
#include <linux/time.h>
#include "reiserfs.h"
#include <linux/buffer_head.h>
/*
* copy copy_count entries from source directory item to dest buffer
* (creating new item if needed)
*/
static void leaf_copy_dir_entries(struct buffer_info *dest_bi,
struct buffer_head *source, int last_first,
int item_num, int from, int copy_count)
{
struct buffer_head *dest = dest_bi->bi_bh;
/*
* either the number of target item, or if we must create a
* new item, the number of the item we will create it next to
*/
int item_num_in_dest;
struct item_head *ih;
struct reiserfs_de_head *deh;
int copy_records_len; /* length of all records in item to be copied */
char *records;
ih = item_head(source, item_num);
RFALSE(!is_direntry_le_ih(ih), "vs-10000: item must be directory item");
/*
* length of all record to be copied and first byte of
* the last of them
*/
deh = B_I_DEH(source, ih);
if (copy_count) {
copy_records_len = (from ? deh_location(&deh[from - 1]) :
ih_item_len(ih)) -
deh_location(&deh[from + copy_count - 1]);
records =
source->b_data + ih_location(ih) +
deh_location(&deh[from + copy_count - 1]);
} else {
copy_records_len = 0;
records = NULL;
}
/* when copy last to first, dest buffer can contain 0 items */
item_num_in_dest =
(last_first ==
LAST_TO_FIRST) ? ((B_NR_ITEMS(dest)) ? 0 : -1) : (B_NR_ITEMS(dest)
- 1);
/*
* if there are no items in dest or the first/last item in
* dest is not item of the same directory
*/
if ((item_num_in_dest == -1) ||
(last_first == FIRST_TO_LAST && le_ih_k_offset(ih) == DOT_OFFSET) ||
(last_first == LAST_TO_FIRST
&& comp_short_le_keys /*COMP_SHORT_KEYS */ (&ih->ih_key,
leaf_key(dest,
item_num_in_dest))))
{
/* create new item in dest */
struct item_head new_ih;
/* form item header */
memcpy(&new_ih.ih_key, &ih->ih_key, KEY_SIZE);
put_ih_version(&new_ih, KEY_FORMAT_3_5);
/* calculate item len */
put_ih_item_len(&new_ih,
DEH_SIZE * copy_count + copy_records_len);
put_ih_entry_count(&new_ih, 0);
if (last_first == LAST_TO_FIRST) {
/* form key by the following way */
if (from < ih_entry_count(ih)) {
set_le_ih_k_offset(&new_ih,
deh_offset(&deh[from]));
} else {
/*
* no entries will be copied to this
* item in this function
*/
set_le_ih_k_offset(&new_ih, U32_MAX);
/*
* this item is not yet valid, but we
* want I_IS_DIRECTORY_ITEM to return 1
* for it, so we -1
*/
}
set_le_key_k_type(KEY_FORMAT_3_5, &new_ih.ih_key,
TYPE_DIRENTRY);
}
/* insert item into dest buffer */
leaf_insert_into_buf(dest_bi,
(last_first ==
LAST_TO_FIRST) ? 0 : B_NR_ITEMS(dest),
&new_ih, NULL, 0);
} else {
/* prepare space for entries */
leaf_paste_in_buffer(dest_bi,
(last_first ==
FIRST_TO_LAST) ? (B_NR_ITEMS(dest) -
1) : 0, MAX_US_INT,
DEH_SIZE * copy_count + copy_records_len,
records, 0);
}
item_num_in_dest =
(last_first == FIRST_TO_LAST) ? (B_NR_ITEMS(dest) - 1) : 0;
leaf_paste_entries(dest_bi, item_num_in_dest,
(last_first ==
FIRST_TO_LAST) ? ih_entry_count(item_head(dest,
item_num_in_dest))
: 0, copy_count, deh + from, records,
DEH_SIZE * copy_count + copy_records_len);
}
/*
* Copy the first (if last_first == FIRST_TO_LAST) or last
* (last_first == LAST_TO_FIRST) item or part of it or nothing
* (see the return 0 below) from SOURCE to the end (if last_first)
* or beginning (!last_first) of the DEST
*/
/* returns 1 if anything was copied, else 0 */
static int leaf_copy_boundary_item(struct buffer_info *dest_bi,
struct buffer_head *src, int last_first,
int bytes_or_entries)
{
struct buffer_head *dest = dest_bi->bi_bh;
/* number of items in the source and destination buffers */
int dest_nr_item, src_nr_item;
struct item_head *ih;
struct item_head *dih;
dest_nr_item = B_NR_ITEMS(dest);
/*
* if ( DEST is empty or first item of SOURCE and last item of
* DEST are the items of different objects or of different types )
* then there is no need to treat this item differently from the
* other items that we copy, so we return
*/
if (last_first == FIRST_TO_LAST) {
ih = item_head(src, 0);
dih = item_head(dest, dest_nr_item - 1);
/* there is nothing to merge */
if (!dest_nr_item
|| (!op_is_left_mergeable(&ih->ih_key, src->b_size)))
return 0;
RFALSE(!ih_item_len(ih),
"vs-10010: item can not have empty length");
if (is_direntry_le_ih(ih)) {
if (bytes_or_entries == -1)
/* copy all entries to dest */
bytes_or_entries = ih_entry_count(ih);
leaf_copy_dir_entries(dest_bi, src, FIRST_TO_LAST, 0, 0,
bytes_or_entries);
return 1;
}
/*
* copy part of the body of the first item of SOURCE
* to the end of the body of the last item of the DEST
* part defined by 'bytes_or_entries'; if bytes_or_entries
* == -1 copy whole body; don't create new item header
*/
if (bytes_or_entries == -1)
bytes_or_entries = ih_item_len(ih);
#ifdef CONFIG_REISERFS_CHECK
else {
if (bytes_or_entries == ih_item_len(ih)
&& is_indirect_le_ih(ih))
if (get_ih_free_space(ih))
reiserfs_panic(sb_from_bi(dest_bi),
"vs-10020",
"last unformatted node "
"must be filled "
"entirely (%h)", ih);
}
#endif
/*
* merge first item (or its part) of src buffer with the last
* item of dest buffer. Both are of the same file
*/
leaf_paste_in_buffer(dest_bi,
dest_nr_item - 1, ih_item_len(dih),
bytes_or_entries, ih_item_body(src, ih), 0);
if (is_indirect_le_ih(dih)) {
RFALSE(get_ih_free_space(dih),
"vs-10030: merge to left: last unformatted node of non-last indirect item %h must have zerto free space",
ih);
if (bytes_or_entries == ih_item_len(ih))
set_ih_free_space(dih, get_ih_free_space(ih));
}
return 1;
}
/* copy boundary item to right (last_first == LAST_TO_FIRST) */
/*
* (DEST is empty or last item of SOURCE and first item of DEST
* are the items of different object or of different types)
*/
src_nr_item = B_NR_ITEMS(src);
ih = item_head(src, src_nr_item - 1);
dih = item_head(dest, 0);
if (!dest_nr_item || !op_is_left_mergeable(&dih->ih_key, src->b_size))
return 0;
if (is_direntry_le_ih(ih)) {
/*
* bytes_or_entries = entries number in last
* item body of SOURCE
*/
if (bytes_or_entries == -1)
bytes_or_entries = ih_entry_count(ih);
leaf_copy_dir_entries(dest_bi, src, LAST_TO_FIRST,
src_nr_item - 1,
ih_entry_count(ih) - bytes_or_entries,
bytes_or_entries);
return 1;
}
/*
* copy part of the body of the last item of SOURCE to the
* begin of the body of the first item of the DEST; part defined
* by 'bytes_or_entries'; if byte_or_entriess == -1 copy whole body;
* change first item key of the DEST; don't create new item header
*/
RFALSE(is_indirect_le_ih(ih) && get_ih_free_space(ih),
"vs-10040: merge to right: last unformatted node of non-last indirect item must be filled entirely (%h)",
ih);
if (bytes_or_entries == -1) {
/* bytes_or_entries = length of last item body of SOURCE */
bytes_or_entries = ih_item_len(ih);
RFALSE(le_ih_k_offset(dih) !=
le_ih_k_offset(ih) + op_bytes_number(ih, src->b_size),
"vs-10050: items %h and %h do not match", ih, dih);
/* change first item key of the DEST */
set_le_ih_k_offset(dih, le_ih_k_offset(ih));
/* item becomes non-mergeable */
/* or mergeable if left item was */
set_le_ih_k_type(dih, le_ih_k_type(ih));
} else {
/* merge to right only part of item */
RFALSE(ih_item_len(ih) <= bytes_or_entries,
"vs-10060: no so much bytes %lu (needed %lu)",
(unsigned long)ih_item_len(ih),
(unsigned long)bytes_or_entries);
/* change first item key of the DEST */
if (is_direct_le_ih(dih)) {
RFALSE(le_ih_k_offset(dih) <=
(unsigned long)bytes_or_entries,
"vs-10070: dih %h, bytes_or_entries(%d)", dih,
bytes_or_entries);
set_le_ih_k_offset(dih,
le_ih_k_offset(dih) -
bytes_or_entries);
} else {
RFALSE(le_ih_k_offset(dih) <=
(bytes_or_entries / UNFM_P_SIZE) * dest->b_size,
"vs-10080: dih %h, bytes_or_entries(%d)",
dih,
(bytes_or_entries / UNFM_P_SIZE) * dest->b_size);
set_le_ih_k_offset(dih,
le_ih_k_offset(dih) -
((bytes_or_entries / UNFM_P_SIZE) *
dest->b_size));
}
}
leaf_paste_in_buffer(dest_bi, 0, 0, bytes_or_entries,
ih_item_body(src,
ih) + ih_item_len(ih) - bytes_or_entries,
0);
return 1;
}
/*
* copy cpy_mun items from buffer src to buffer dest
* last_first == FIRST_TO_LAST means, that we copy cpy_num items beginning
* from first-th item in src to tail of dest
* last_first == LAST_TO_FIRST means, that we copy cpy_num items beginning
* from first-th item in src to head of dest
*/
static void leaf_copy_items_entirely(struct buffer_info *dest_bi,
struct buffer_head *src, int last_first,
int first, int cpy_num)
{
struct buffer_head *dest;
int nr, free_space;
int dest_before;
int last_loc, last_inserted_loc, location;
int i, j;
struct block_head *blkh;
struct item_head *ih;
RFALSE(last_first != LAST_TO_FIRST && last_first != FIRST_TO_LAST,
"vs-10090: bad last_first parameter %d", last_first);
RFALSE(B_NR_ITEMS(src) - first < cpy_num,
"vs-10100: too few items in source %d, required %d from %d",
B_NR_ITEMS(src), cpy_num, first);
RFALSE(cpy_num < 0, "vs-10110: can not copy negative amount of items");
RFALSE(!dest_bi, "vs-10120: can not copy negative amount of items");
dest = dest_bi->bi_bh;
RFALSE(!dest, "vs-10130: can not copy negative amount of items");
if (cpy_num == 0)
return;
blkh = B_BLK_HEAD(dest);
nr = blkh_nr_item(blkh);
free_space = blkh_free_space(blkh);
/*
* we will insert items before 0-th or nr-th item in dest buffer.
* It depends of last_first parameter
*/
dest_before = (last_first == LAST_TO_FIRST) ? 0 : nr;
/* location of head of first new item */
ih = item_head(dest, dest_before);
RFALSE(blkh_free_space(blkh) < cpy_num * IH_SIZE,
"vs-10140: not enough free space for headers %d (needed %d)",
B_FREE_SPACE(dest), cpy_num * IH_SIZE);
/* prepare space for headers */
memmove(ih + cpy_num, ih, (nr - dest_before) * IH_SIZE);
/* copy item headers */
memcpy(ih, item_head(src, first), cpy_num * IH_SIZE);
free_space -= (IH_SIZE * cpy_num);
set_blkh_free_space(blkh, free_space);
/* location of unmovable item */
j = location = (dest_before == 0) ? dest->b_size : ih_location(ih - 1);
for (i = dest_before; i < nr + cpy_num; i++) {
location -= ih_item_len(ih + i - dest_before);
put_ih_location(ih + i - dest_before, location);
}
/* prepare space for items */
last_loc = ih_location(&ih[nr + cpy_num - 1 - dest_before]);
last_inserted_loc = ih_location(&ih[cpy_num - 1]);
/* check free space */
RFALSE(free_space < j - last_inserted_loc,
"vs-10150: not enough free space for items %d (needed %d)",
free_space, j - last_inserted_loc);
memmove(dest->b_data + last_loc,
dest->b_data + last_loc + j - last_inserted_loc,
last_inserted_loc - last_loc);
/* copy items */
memcpy(dest->b_data + last_inserted_loc,
item_body(src, (first + cpy_num - 1)),
j - last_inserted_loc);
/* sizes, item number */
set_blkh_nr_item(blkh, nr + cpy_num);
set_blkh_free_space(blkh, free_space - (j - last_inserted_loc));
do_balance_mark_leaf_dirty(dest_bi->tb, dest, 0);
if (dest_bi->bi_parent) {
struct disk_child *t_dc;
t_dc = B_N_CHILD(dest_bi->bi_parent, dest_bi->bi_position);
RFALSE(dc_block_number(t_dc) != dest->b_blocknr,
"vs-10160: block number in bh does not match to field in disk_child structure %lu and %lu",
(long unsigned)dest->b_blocknr,
(long unsigned)dc_block_number(t_dc));
put_dc_size(t_dc,
dc_size(t_dc) + (j - last_inserted_loc +
IH_SIZE * cpy_num));
do_balance_mark_internal_dirty(dest_bi->tb, dest_bi->bi_parent,
0);
}
}
/*
* This function splits the (liquid) item into two items (useful when
* shifting part of an item into another node.)
*/
static void leaf_item_bottle(struct buffer_info *dest_bi,
struct buffer_head *src, int last_first,
int item_num, int cpy_bytes)
{
struct buffer_head *dest = dest_bi->bi_bh;
struct item_head *ih;
RFALSE(cpy_bytes == -1,
"vs-10170: bytes == - 1 means: do not split item");
if (last_first == FIRST_TO_LAST) {
/*
* if ( if item in position item_num in buffer SOURCE
* is directory item )
*/
ih = item_head(src, item_num);
if (is_direntry_le_ih(ih))
leaf_copy_dir_entries(dest_bi, src, FIRST_TO_LAST,
item_num, 0, cpy_bytes);
else {
struct item_head n_ih;
/*
* copy part of the body of the item number 'item_num'
* of SOURCE to the end of the DEST part defined by
* 'cpy_bytes'; create new item header; change old
* item_header (????); n_ih = new item_header;
*/
memcpy(&n_ih, ih, IH_SIZE);
put_ih_item_len(&n_ih, cpy_bytes);
if (is_indirect_le_ih(ih)) {
RFALSE(cpy_bytes == ih_item_len(ih)
&& get_ih_free_space(ih),
"vs-10180: when whole indirect item is bottle to left neighbor, it must have free_space==0 (not %lu)",
(long unsigned)get_ih_free_space(ih));
set_ih_free_space(&n_ih, 0);
}
RFALSE(op_is_left_mergeable(&ih->ih_key, src->b_size),
"vs-10190: bad mergeability of item %h", ih);
n_ih.ih_version = ih->ih_version; /* JDM Endian safe, both le */
leaf_insert_into_buf(dest_bi, B_NR_ITEMS(dest), &n_ih,
item_body(src, item_num), 0);
}
} else {
/*
* if ( if item in position item_num in buffer
* SOURCE is directory item )
*/
ih = item_head(src, item_num);
if (is_direntry_le_ih(ih))
leaf_copy_dir_entries(dest_bi, src, LAST_TO_FIRST,
item_num,
ih_entry_count(ih) - cpy_bytes,
cpy_bytes);
else {
struct item_head n_ih;
/*
* copy part of the body of the item number 'item_num'
* of SOURCE to the begin of the DEST part defined by
* 'cpy_bytes'; create new item header;
* n_ih = new item_header;
*/
memcpy(&n_ih.ih_key, &ih->ih_key, KEY_SIZE);
/* Endian safe, both le */
n_ih.ih_version = ih->ih_version;
if (is_direct_le_ih(ih)) {
set_le_ih_k_offset(&n_ih,
le_ih_k_offset(ih) +
ih_item_len(ih) - cpy_bytes);
set_le_ih_k_type(&n_ih, TYPE_DIRECT);
set_ih_free_space(&n_ih, MAX_US_INT);
} else {
/* indirect item */
RFALSE(!cpy_bytes && get_ih_free_space(ih),
"vs-10200: ih->ih_free_space must be 0 when indirect item will be appended");
set_le_ih_k_offset(&n_ih,
le_ih_k_offset(ih) +
(ih_item_len(ih) -
cpy_bytes) / UNFM_P_SIZE *
dest->b_size);
set_le_ih_k_type(&n_ih, TYPE_INDIRECT);
set_ih_free_space(&n_ih, get_ih_free_space(ih));
}
/* set item length */
put_ih_item_len(&n_ih, cpy_bytes);
/* Endian safe, both le */
n_ih.ih_version = ih->ih_version;
leaf_insert_into_buf(dest_bi, 0, &n_ih,
item_body(src, item_num) +
ih_item_len(ih) - cpy_bytes, 0);
}
}
}
/*
* If cpy_bytes equals minus one than copy cpy_num whole items from SOURCE
* to DEST. If cpy_bytes not equal to minus one than copy cpy_num-1 whole
* items from SOURCE to DEST. From last item copy cpy_num bytes for regular
* item and cpy_num directory entries for directory item.
*/
static int leaf_copy_items(struct buffer_info *dest_bi, struct buffer_head *src,
int last_first, int cpy_num, int cpy_bytes)
{
struct buffer_head *dest;
int pos, i, src_nr_item, bytes;
dest = dest_bi->bi_bh;
RFALSE(!dest || !src, "vs-10210: !dest || !src");
RFALSE(last_first != FIRST_TO_LAST && last_first != LAST_TO_FIRST,
"vs-10220:last_first != FIRST_TO_LAST && last_first != LAST_TO_FIRST");
RFALSE(B_NR_ITEMS(src) < cpy_num,
"vs-10230: No enough items: %d, req. %d", B_NR_ITEMS(src),
cpy_num);
RFALSE(cpy_num < 0, "vs-10240: cpy_num < 0 (%d)", cpy_num);
if (cpy_num == 0)
return 0;
if (last_first == FIRST_TO_LAST) {
/* copy items to left */
pos = 0;
if (cpy_num == 1)
bytes = cpy_bytes;
else
bytes = -1;
/*
* copy the first item or it part or nothing to the end of
* the DEST (i = leaf_copy_boundary_item(DEST,SOURCE,0,bytes))
*/
i = leaf_copy_boundary_item(dest_bi, src, FIRST_TO_LAST, bytes);
cpy_num -= i;
if (cpy_num == 0)
return i;
pos += i;
if (cpy_bytes == -1)
/*
* copy first cpy_num items starting from position
* 'pos' of SOURCE to end of DEST
*/
leaf_copy_items_entirely(dest_bi, src, FIRST_TO_LAST,
pos, cpy_num);
else {
/*
* copy first cpy_num-1 items starting from position
* 'pos-1' of the SOURCE to the end of the DEST
*/
leaf_copy_items_entirely(dest_bi, src, FIRST_TO_LAST,
pos, cpy_num - 1);
/*
* copy part of the item which number is
* cpy_num+pos-1 to the end of the DEST
*/
leaf_item_bottle(dest_bi, src, FIRST_TO_LAST,
cpy_num + pos - 1, cpy_bytes);
}
} else {
/* copy items to right */
src_nr_item = B_NR_ITEMS(src);
if (cpy_num == 1)
bytes = cpy_bytes;
else
bytes = -1;
/*
* copy the last item or it part or nothing to the
* begin of the DEST
* (i = leaf_copy_boundary_item(DEST,SOURCE,1,bytes));
*/
i = leaf_copy_boundary_item(dest_bi, src, LAST_TO_FIRST, bytes);
cpy_num -= i;
if (cpy_num == 0)
return i;
pos = src_nr_item - cpy_num - i;
if (cpy_bytes == -1) {
/*
* starting from position 'pos' copy last cpy_num
* items of SOURCE to begin of DEST
*/
leaf_copy_items_entirely(dest_bi, src, LAST_TO_FIRST,
pos, cpy_num);
} else {
/*
* copy last cpy_num-1 items starting from position
* 'pos+1' of the SOURCE to the begin of the DEST;
*/
leaf_copy_items_entirely(dest_bi, src, LAST_TO_FIRST,
pos + 1, cpy_num - 1);
/*
* copy part of the item which number is pos to
* the begin of the DEST
*/
leaf_item_bottle(dest_bi, src, LAST_TO_FIRST, pos,
cpy_bytes);
}
}
return i;
}
/*
* there are types of coping: from S[0] to L[0], from S[0] to R[0],
* from R[0] to L[0]. for each of these we have to define parent and
* positions of destination and source buffers
*/
static void leaf_define_dest_src_infos(int shift_mode, struct tree_balance *tb,
struct buffer_info *dest_bi,
struct buffer_info *src_bi,
int *first_last,
struct buffer_head *Snew)
{
memset(dest_bi, 0, sizeof(struct buffer_info));
memset(src_bi, 0, sizeof(struct buffer_info));
/* define dest, src, dest parent, dest position */
switch (shift_mode) {
case LEAF_FROM_S_TO_L: /* it is used in leaf_shift_left */
src_bi->tb = tb;
src_bi->bi_bh = PATH_PLAST_BUFFER(tb->tb_path);
src_bi->bi_parent = PATH_H_PPARENT(tb->tb_path, 0);
/* src->b_item_order */
src_bi->bi_position = PATH_H_B_ITEM_ORDER(tb->tb_path, 0);
dest_bi->tb = tb;
dest_bi->bi_bh = tb->L[0];
dest_bi->bi_parent = tb->FL[0];
dest_bi->bi_position = get_left_neighbor_position(tb, 0);
*first_last = FIRST_TO_LAST;
break;
case LEAF_FROM_S_TO_R: /* it is used in leaf_shift_right */
src_bi->tb = tb;
src_bi->bi_bh = PATH_PLAST_BUFFER(tb->tb_path);
src_bi->bi_parent = PATH_H_PPARENT(tb->tb_path, 0);
src_bi->bi_position = PATH_H_B_ITEM_ORDER(tb->tb_path, 0);
dest_bi->tb = tb;
dest_bi->bi_bh = tb->R[0];
dest_bi->bi_parent = tb->FR[0];
dest_bi->bi_position = get_right_neighbor_position(tb, 0);
*first_last = LAST_TO_FIRST;
break;
case LEAF_FROM_R_TO_L: /* it is used in balance_leaf_when_delete */
src_bi->tb = tb;
src_bi->bi_bh = tb->R[0];
src_bi->bi_parent = tb->FR[0];
src_bi->bi_position = get_right_neighbor_position(tb, 0);
dest_bi->tb = tb;
dest_bi->bi_bh = tb->L[0];
dest_bi->bi_parent = tb->FL[0];
dest_bi->bi_position = get_left_neighbor_position(tb, 0);
*first_last = FIRST_TO_LAST;
break;
case LEAF_FROM_L_TO_R: /* it is used in balance_leaf_when_delete */
src_bi->tb = tb;
src_bi->bi_bh = tb->L[0];
src_bi->bi_parent = tb->FL[0];
src_bi->bi_position = get_left_neighbor_position(tb, 0);
dest_bi->tb = tb;
dest_bi->bi_bh = tb->R[0];
dest_bi->bi_parent = tb->FR[0];
dest_bi->bi_position = get_right_neighbor_position(tb, 0);
*first_last = LAST_TO_FIRST;
break;
case LEAF_FROM_S_TO_SNEW:
src_bi->tb = tb;
src_bi->bi_bh = PATH_PLAST_BUFFER(tb->tb_path);
src_bi->bi_parent = PATH_H_PPARENT(tb->tb_path, 0);
src_bi->bi_position = PATH_H_B_ITEM_ORDER(tb->tb_path, 0);
dest_bi->tb = tb;
dest_bi->bi_bh = Snew;
dest_bi->bi_parent = NULL;
dest_bi->bi_position = 0;
*first_last = LAST_TO_FIRST;
break;
default:
reiserfs_panic(sb_from_bi(src_bi), "vs-10250",
"shift type is unknown (%d)", shift_mode);
}
RFALSE(!src_bi->bi_bh || !dest_bi->bi_bh,
"vs-10260: mode==%d, source (%p) or dest (%p) buffer is initialized incorrectly",
shift_mode, src_bi->bi_bh, dest_bi->bi_bh);
}
/*
* copy mov_num items and mov_bytes of the (mov_num-1)th item to
* neighbor. Delete them from source
*/
int leaf_move_items(int shift_mode, struct tree_balance *tb, int mov_num,
int mov_bytes, struct buffer_head *Snew)
{
int ret_value;
struct buffer_info dest_bi, src_bi;
int first_last;
leaf_define_dest_src_infos(shift_mode, tb, &dest_bi, &src_bi,
&first_last, Snew);
ret_value =
leaf_copy_items(&dest_bi, src_bi.bi_bh, first_last, mov_num,
mov_bytes);
leaf_delete_items(&src_bi, first_last,
(first_last ==
FIRST_TO_LAST) ? 0 : (B_NR_ITEMS(src_bi.bi_bh) -
mov_num), mov_num, mov_bytes);
return ret_value;
}
/*
* Shift shift_num items (and shift_bytes of last shifted item if
* shift_bytes != -1) from S[0] to L[0] and replace the delimiting key
*/
int leaf_shift_left(struct tree_balance *tb, int shift_num, int shift_bytes)
{
struct buffer_head *S0 = PATH_PLAST_BUFFER(tb->tb_path);
int i;
/*
* move shift_num (and shift_bytes bytes) items from S[0]
* to left neighbor L[0]
*/
i = leaf_move_items(LEAF_FROM_S_TO_L, tb, shift_num, shift_bytes, NULL);
if (shift_num) {
/* number of items in S[0] == 0 */
if (B_NR_ITEMS(S0) == 0) {
RFALSE(shift_bytes != -1,
"vs-10270: S0 is empty now, but shift_bytes != -1 (%d)",
shift_bytes);
#ifdef CONFIG_REISERFS_CHECK
if (tb->tb_mode == M_PASTE || tb->tb_mode == M_INSERT) {
print_cur_tb("vs-10275");
reiserfs_panic(tb->tb_sb, "vs-10275",
"balance condition corrupted "
"(%c)", tb->tb_mode);
}
#endif
if (PATH_H_POSITION(tb->tb_path, 1) == 0)
replace_key(tb, tb->CFL[0], tb->lkey[0],
PATH_H_PPARENT(tb->tb_path, 0), 0);
} else {
/* replace lkey in CFL[0] by 0-th key from S[0]; */
replace_key(tb, tb->CFL[0], tb->lkey[0], S0, 0);
RFALSE((shift_bytes != -1 &&
!(is_direntry_le_ih(item_head(S0, 0))
&& !ih_entry_count(item_head(S0, 0)))) &&
(!op_is_left_mergeable
(leaf_key(S0, 0), S0->b_size)),
"vs-10280: item must be mergeable");
}
}
return i;
}
/* CLEANING STOPPED HERE */
/*
* Shift shift_num (shift_bytes) items from S[0] to the right neighbor,
* and replace the delimiting key
*/
int leaf_shift_right(struct tree_balance *tb, int shift_num, int shift_bytes)
{
int ret_value;
/*
* move shift_num (and shift_bytes) items from S[0] to
* right neighbor R[0]
*/
ret_value =
leaf_move_items(LEAF_FROM_S_TO_R, tb, shift_num, shift_bytes, NULL);
/* replace rkey in CFR[0] by the 0-th key from R[0] */
if (shift_num) {
replace_key(tb, tb->CFR[0], tb->rkey[0], tb->R[0], 0);
}
return ret_value;
}
static void leaf_delete_items_entirely(struct buffer_info *bi,
int first, int del_num);
/*
* If del_bytes == -1, starting from position 'first' delete del_num
* items in whole in buffer CUR.
* If not.
* If last_first == 0. Starting from position 'first' delete del_num-1
* items in whole. Delete part of body of the first item. Part defined by
* del_bytes. Don't delete first item header
* If last_first == 1. Starting from position 'first+1' delete del_num-1
* items in whole. Delete part of body of the last item . Part defined by
* del_bytes. Don't delete last item header.
*/
void leaf_delete_items(struct buffer_info *cur_bi, int last_first,
int first, int del_num, int del_bytes)
{
struct buffer_head *bh;
int item_amount = B_NR_ITEMS(bh = cur_bi->bi_bh);
RFALSE(!bh, "10155: bh is not defined");
RFALSE(del_num < 0, "10160: del_num can not be < 0. del_num==%d",
del_num);
RFALSE(first < 0
|| first + del_num > item_amount,
"10165: invalid number of first item to be deleted (%d) or "
"no so much items (%d) to delete (only %d)", first,
first + del_num, item_amount);
if (del_num == 0)
return;
if (first == 0 && del_num == item_amount && del_bytes == -1) {
make_empty_node(cur_bi);
do_balance_mark_leaf_dirty(cur_bi->tb, bh, 0);
return;
}
if (del_bytes == -1)
/* delete del_num items beginning from item in position first */
leaf_delete_items_entirely(cur_bi, first, del_num);
else {
if (last_first == FIRST_TO_LAST) {
/*
* delete del_num-1 items beginning from
* item in position first
*/
leaf_delete_items_entirely(cur_bi, first, del_num - 1);
/*
* delete the part of the first item of the bh
* do not delete item header
*/
leaf_cut_from_buffer(cur_bi, 0, 0, del_bytes);
} else {
struct item_head *ih;
int len;
/*
* delete del_num-1 items beginning from
* item in position first+1
*/
leaf_delete_items_entirely(cur_bi, first + 1,
del_num - 1);
ih = item_head(bh, B_NR_ITEMS(bh) - 1);
if (is_direntry_le_ih(ih))
/* the last item is directory */
/*
* len = numbers of directory entries
* in this item
*/
len = ih_entry_count(ih);
else
/* len = body len of item */
len = ih_item_len(ih);
/*
* delete the part of the last item of the bh
* do not delete item header
*/
leaf_cut_from_buffer(cur_bi, B_NR_ITEMS(bh) - 1,
len - del_bytes, del_bytes);
}
}
}
/* insert item into the leaf node in position before */
void leaf_insert_into_buf(struct buffer_info *bi, int before,
struct item_head * const inserted_item_ih,
const char * const inserted_item_body,
int zeros_number)
{
struct buffer_head *bh = bi->bi_bh;
int nr, free_space;
struct block_head *blkh;
struct item_head *ih;
int i;
int last_loc, unmoved_loc;
char *to;
blkh = B_BLK_HEAD(bh);
nr = blkh_nr_item(blkh);
free_space = blkh_free_space(blkh);
/* check free space */
RFALSE(free_space < ih_item_len(inserted_item_ih) + IH_SIZE,
"vs-10170: not enough free space in block %z, new item %h",
bh, inserted_item_ih);
RFALSE(zeros_number > ih_item_len(inserted_item_ih),
"vs-10172: zero number == %d, item length == %d",
zeros_number, ih_item_len(inserted_item_ih));
/* get item new item must be inserted before */
ih = item_head(bh, before);
/* prepare space for the body of new item */
last_loc = nr ? ih_location(&ih[nr - before - 1]) : bh->b_size;
unmoved_loc = before ? ih_location(ih - 1) : bh->b_size;
memmove(bh->b_data + last_loc - ih_item_len(inserted_item_ih),
bh->b_data + last_loc, unmoved_loc - last_loc);
to = bh->b_data + unmoved_loc - ih_item_len(inserted_item_ih);
memset(to, 0, zeros_number);
to += zeros_number;
/* copy body to prepared space */
if (inserted_item_body)
memmove(to, inserted_item_body,
ih_item_len(inserted_item_ih) - zeros_number);
else
memset(to, '\0', ih_item_len(inserted_item_ih) - zeros_number);
/* insert item header */
memmove(ih + 1, ih, IH_SIZE * (nr - before));
memmove(ih, inserted_item_ih, IH_SIZE);
/* change locations */
for (i = before; i < nr + 1; i++) {
unmoved_loc -= ih_item_len(&ih[i - before]);
put_ih_location(&ih[i - before], unmoved_loc);
}
/* sizes, free space, item number */
set_blkh_nr_item(blkh, blkh_nr_item(blkh) + 1);
set_blkh_free_space(blkh,
free_space - (IH_SIZE +
ih_item_len(inserted_item_ih)));
do_balance_mark_leaf_dirty(bi->tb, bh, 1);
if (bi->bi_parent) {
struct disk_child *t_dc;
t_dc = B_N_CHILD(bi->bi_parent, bi->bi_position);
put_dc_size(t_dc,
dc_size(t_dc) + (IH_SIZE +
ih_item_len(inserted_item_ih)));
do_balance_mark_internal_dirty(bi->tb, bi->bi_parent, 0);
}
}
/*
* paste paste_size bytes to affected_item_num-th item.
* When item is a directory, this only prepare space for new entries
*/
void leaf_paste_in_buffer(struct buffer_info *bi, int affected_item_num,
int pos_in_item, int paste_size,
const char *body, int zeros_number)
{
struct buffer_head *bh = bi->bi_bh;
int nr, free_space;
struct block_head *blkh;
struct item_head *ih;
int i;
int last_loc, unmoved_loc;
blkh = B_BLK_HEAD(bh);
nr = blkh_nr_item(blkh);
free_space = blkh_free_space(blkh);
/* check free space */
RFALSE(free_space < paste_size,
"vs-10175: not enough free space: needed %d, available %d",
paste_size, free_space);
#ifdef CONFIG_REISERFS_CHECK
if (zeros_number > paste_size) {
struct super_block *sb = NULL;