btrfs-progs/ctree.c

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2007-06-12 13:07:11 +00:00
/*
* Copyright (C) 2007 Oracle. All rights reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License v2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
#include <stdio.h>
#include <stdlib.h>
#include "kerncompat.h"
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#include "radix-tree.h"
#include "ctree.h"
#include "disk-io.h"
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#include "print-tree.h"
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static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root
*root, struct btrfs_path *path, int level);
static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
*root, struct btrfs_path *path, int data_size);
static int push_node_left(struct btrfs_trans_handle *trans, struct btrfs_root
*root, struct btrfs_buffer *dst, struct btrfs_buffer
*src);
static int balance_node_right(struct btrfs_trans_handle *trans, struct
btrfs_root *root, struct btrfs_buffer *dst_buf,
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struct btrfs_buffer *src_buf);
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static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
struct btrfs_path *path, int level, int slot);
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inline void btrfs_init_path(struct btrfs_path *p)
{
memset(p, 0, sizeof(*p));
}
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void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p)
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{
int i;
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for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
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if (!p->nodes[i])
break;
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btrfs_block_release(root, p->nodes[i]);
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}
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memset(p, 0, sizeof(*p));
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}
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static int btrfs_cow_block(struct btrfs_trans_handle *trans, struct btrfs_root
*root, struct btrfs_buffer *buf, struct btrfs_buffer
*parent, int parent_slot, struct btrfs_buffer
**cow_ret)
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{
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struct btrfs_buffer *cow;
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if (!list_empty(&buf->dirty)) {
*cow_ret = buf;
return 0;
}
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cow = btrfs_alloc_free_block(trans, root);
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memcpy(&cow->node, &buf->node, root->blocksize);
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btrfs_set_header_blocknr(&cow->node.header, cow->blocknr);
btrfs_set_header_owner(&cow->node.header, root->root_key.objectid);
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*cow_ret = cow;
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btrfs_inc_ref(trans, root, buf);
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if (buf == root->node) {
root->node = cow;
cow->count++;
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if (buf != root->commit_root)
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btrfs_free_extent(trans, root, buf->blocknr, 1, 1);
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btrfs_block_release(root, buf);
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} else {
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btrfs_set_node_blockptr(&parent->node, parent_slot,
cow->blocknr);
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BUG_ON(list_empty(&parent->dirty));
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btrfs_free_extent(trans, root, buf->blocknr, 1, 1);
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}
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btrfs_block_release(root, buf);
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return 0;
}
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/*
* The leaf data grows from end-to-front in the node.
* this returns the address of the start of the last item,
* which is the stop of the leaf data stack
*/
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static inline unsigned int leaf_data_end(struct btrfs_root *root,
struct btrfs_leaf *leaf)
{
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u32 nr = btrfs_header_nritems(&leaf->header);
if (nr == 0)
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return BTRFS_LEAF_DATA_SIZE(root);
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return btrfs_item_offset(leaf->items + nr - 1);
}
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/*
* how many bytes are required to store the items in a leaf. start
* and nr indicate which items in the leaf to check. This totals up the
* space used both by the item structs and the item data
*/
static int leaf_space_used(struct btrfs_leaf *l, int start, int nr)
{
int data_len;
int nritems = btrfs_header_nritems(&l->header);
int end;
if (nritems < start + nr)
end = nritems - 1;
else
end = start + nr - 1;
if (!nr)
return 0;
data_len = btrfs_item_end(l->items + start);
data_len = data_len - btrfs_item_offset(l->items + end);
data_len += sizeof(struct btrfs_item) * nr;
return data_len;
}
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/*
* The space between the end of the leaf items and
* the start of the leaf data. IOW, how much room
* the leaf has left for both items and data
*/
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int btrfs_leaf_free_space(struct btrfs_root *root, struct btrfs_leaf *leaf)
{
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int nritems = btrfs_header_nritems(&leaf->header);
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return BTRFS_LEAF_DATA_SIZE(root) - leaf_space_used(leaf, 0, nritems);
}
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/*
* compare two keys in a memcmp fashion
*/
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int btrfs_comp_keys(struct btrfs_disk_key *disk, struct btrfs_key *k2)
{
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struct btrfs_key k1;
btrfs_disk_key_to_cpu(&k1, disk);
if (k1.objectid > k2->objectid)
return 1;
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if (k1.objectid < k2->objectid)
return -1;
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if (k1.flags > k2->flags)
return 1;
if (k1.flags < k2->flags)
return -1;
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if (k1.offset > k2->offset)
return 1;
if (k1.offset < k2->offset)
return -1;
return 0;
}
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static int check_node(struct btrfs_root *root, struct btrfs_path *path,
int level)
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{
int i;
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struct btrfs_node *parent = NULL;
struct btrfs_node *node = &path->nodes[level]->node;
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int parent_slot;
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u32 nritems = btrfs_header_nritems(&node->header);
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if (path->nodes[level + 1])
parent = &path->nodes[level + 1]->node;
parent_slot = path->slots[level + 1];
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BUG_ON(nritems == 0);
if (parent) {
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struct btrfs_disk_key *parent_key;
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parent_key = &parent->ptrs[parent_slot].key;
BUG_ON(memcmp(parent_key, &node->ptrs[0].key,
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sizeof(struct btrfs_disk_key)));
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BUG_ON(btrfs_node_blockptr(parent, parent_slot) !=
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btrfs_header_blocknr(&node->header));
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}
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BUG_ON(nritems > BTRFS_NODEPTRS_PER_BLOCK(root));
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for (i = 0; nritems > 1 && i < nritems - 2; i++) {
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struct btrfs_key cpukey;
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btrfs_disk_key_to_cpu(&cpukey, &node->ptrs[i + 1].key);
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BUG_ON(btrfs_comp_keys(&node->ptrs[i].key, &cpukey) >= 0);
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}
return 0;
}
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static int check_leaf(struct btrfs_root *root, struct btrfs_path *path,
int level)
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{
int i;
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struct btrfs_leaf *leaf = &path->nodes[level]->leaf;
struct btrfs_node *parent = NULL;
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int parent_slot;
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u32 nritems = btrfs_header_nritems(&leaf->header);
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if (path->nodes[level + 1])
parent = &path->nodes[level + 1]->node;
parent_slot = path->slots[level + 1];
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BUG_ON(btrfs_leaf_free_space(root, leaf) < 0);
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if (nritems == 0)
return 0;
if (parent) {
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struct btrfs_disk_key *parent_key;
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parent_key = &parent->ptrs[parent_slot].key;
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BUG_ON(memcmp(parent_key, &leaf->items[0].key,
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sizeof(struct btrfs_disk_key)));
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BUG_ON(btrfs_node_blockptr(parent, parent_slot) !=
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btrfs_header_blocknr(&leaf->header));
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}
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for (i = 0; nritems > 1 && i < nritems - 2; i++) {
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struct btrfs_key cpukey;
btrfs_disk_key_to_cpu(&cpukey, &leaf->items[i + 1].key);
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BUG_ON(btrfs_comp_keys(&leaf->items[i].key,
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&cpukey) >= 0);
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BUG_ON(btrfs_item_offset(leaf->items + i) !=
btrfs_item_end(leaf->items + i + 1));
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if (i == 0) {
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BUG_ON(btrfs_item_offset(leaf->items + i) +
btrfs_item_size(leaf->items + i) !=
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BTRFS_LEAF_DATA_SIZE(root));
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}
}
return 0;
}
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static int check_block(struct btrfs_root *root, struct btrfs_path *path,
int level)
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{
if (level == 0)
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return check_leaf(root, path, level);
return check_node(root, path, level);
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}
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/*
* search for key in the array p. items p are item_size apart
* and there are 'max' items in p
* the slot in the array is returned via slot, and it points to
* the place where you would insert key if it is not found in
* the array.
*
* slot may point to max if the key is bigger than all of the keys
*/
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static int generic_bin_search(char *p, int item_size, struct btrfs_key *key,
int max, int *slot)
{
int low = 0;
int high = max;
int mid;
int ret;
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struct btrfs_disk_key *tmp;
while(low < high) {
mid = (low + high) / 2;
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tmp = (struct btrfs_disk_key *)(p + mid * item_size);
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ret = btrfs_comp_keys(tmp, key);
if (ret < 0)
low = mid + 1;
else if (ret > 0)
high = mid;
else {
*slot = mid;
return 0;
}
}
*slot = low;
return 1;
}
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/*
* simple bin_search frontend that does the right thing for
* leaves vs nodes
*/
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static int bin_search(struct btrfs_node *c, struct btrfs_key *key, int *slot)
{
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if (btrfs_is_leaf(c)) {
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struct btrfs_leaf *l = (struct btrfs_leaf *)c;
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return generic_bin_search((void *)l->items,
sizeof(struct btrfs_item),
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key, btrfs_header_nritems(&c->header),
slot);
} else {
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return generic_bin_search((void *)c->ptrs,
sizeof(struct btrfs_key_ptr),
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key, btrfs_header_nritems(&c->header),
slot);
}
return -1;
}
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static struct btrfs_buffer *read_node_slot(struct btrfs_root *root,
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struct btrfs_buffer *parent_buf,
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int slot)
{
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struct btrfs_node *node = &parent_buf->node;
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if (slot < 0)
return NULL;
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if (slot >= btrfs_header_nritems(&node->header))
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return NULL;
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return read_tree_block(root, btrfs_node_blockptr(node, slot));
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}
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static int balance_level(struct btrfs_trans_handle *trans, struct btrfs_root
*root, struct btrfs_path *path, int level)
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{
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struct btrfs_buffer *right_buf;
struct btrfs_buffer *mid_buf;
struct btrfs_buffer *left_buf;
struct btrfs_buffer *parent_buf = NULL;
struct btrfs_node *right = NULL;
struct btrfs_node *mid;
struct btrfs_node *left = NULL;
struct btrfs_node *parent = NULL;
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int ret = 0;
int wret;
int pslot;
int orig_slot = path->slots[level];
u64 orig_ptr;
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if (level == 0)
return 0;
mid_buf = path->nodes[level];
mid = &mid_buf->node;
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orig_ptr = btrfs_node_blockptr(mid, orig_slot);
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if (level < BTRFS_MAX_LEVEL - 1)
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parent_buf = path->nodes[level + 1];
pslot = path->slots[level + 1];
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/*
* deal with the case where there is only one pointer in the root
* by promoting the node below to a root
*/
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if (!parent_buf) {
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struct btrfs_buffer *child;
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u64 blocknr = mid_buf->blocknr;
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if (btrfs_header_nritems(&mid->header) != 1)
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return 0;
/* promote the child to a root */
child = read_node_slot(root, mid_buf, 0);
BUG_ON(!child);
root->node = child;
path->nodes[level] = NULL;
/* once for the path */
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btrfs_block_release(root, mid_buf);
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/* once for the root ptr */
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btrfs_block_release(root, mid_buf);
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clean_tree_block(trans, root, mid_buf);
return btrfs_free_extent(trans, root, blocknr, 1, 1);
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}
parent = &parent_buf->node;
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if (btrfs_header_nritems(&mid->header) >
BTRFS_NODEPTRS_PER_BLOCK(root) / 4)
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return 0;
left_buf = read_node_slot(root, parent_buf, pslot - 1);
right_buf = read_node_slot(root, parent_buf, pslot + 1);
/* first, try to make some room in the middle buffer */
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if (left_buf) {
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btrfs_cow_block(trans, root, left_buf, parent_buf, pslot - 1,
&left_buf);
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left = &left_buf->node;
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orig_slot += btrfs_header_nritems(&left->header);
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wret = push_node_left(trans, root, left_buf, mid_buf);
if (wret < 0)
ret = wret;
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}
/*
* then try to empty the right most buffer into the middle
*/
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if (right_buf) {
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btrfs_cow_block(trans, root, right_buf, parent_buf, pslot + 1,
&right_buf);
right = &right_buf->node;
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wret = push_node_left(trans, root, mid_buf, right_buf);
if (wret < 0)
ret = wret;
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if (btrfs_header_nritems(&right->header) == 0) {
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u64 blocknr = right_buf->blocknr;
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btrfs_block_release(root, right_buf);
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clean_tree_block(trans, root, right_buf);
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right_buf = NULL;
right = NULL;
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wret = del_ptr(trans, root, path, level + 1, pslot +
1);
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if (wret)
ret = wret;
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wret = btrfs_free_extent(trans, root, blocknr, 1, 1);
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if (wret)
ret = wret;
} else {
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memcpy(&parent->ptrs[pslot + 1].key,
&right->ptrs[0].key,
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sizeof(struct btrfs_disk_key));
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BUG_ON(list_empty(&parent_buf->dirty));
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}
}
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if (btrfs_header_nritems(&mid->header) == 1) {
/*
* we're not allowed to leave a node with one item in the
* tree during a delete. A deletion from lower in the tree
* could try to delete the only pointer in this node.
* So, pull some keys from the left.
* There has to be a left pointer at this point because
* otherwise we would have pulled some pointers from the
* right
*/
BUG_ON(!left_buf);
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wret = balance_node_right(trans, root, mid_buf, left_buf);
if (wret < 0)
ret = wret;
BUG_ON(wret == 1);
}
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if (btrfs_header_nritems(&mid->header) == 0) {
/* we've managed to empty the middle node, drop it */
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u64 blocknr = mid_buf->blocknr;
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btrfs_block_release(root, mid_buf);
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clean_tree_block(trans, root, mid_buf);
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mid_buf = NULL;
mid = NULL;
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wret = del_ptr(trans, root, path, level + 1, pslot);
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if (wret)
ret = wret;
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wret = btrfs_free_extent(trans, root, blocknr, 1, 1);
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if (wret)
ret = wret;
} else {
/* update the parent key to reflect our changes */
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memcpy(&parent->ptrs[pslot].key, &mid->ptrs[0].key,
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sizeof(struct btrfs_disk_key));
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BUG_ON(list_empty(&parent_buf->dirty));
}
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/* update the path */
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if (left_buf) {
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if (btrfs_header_nritems(&left->header) > orig_slot) {
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left_buf->count++; // released below
path->nodes[level] = left_buf;
path->slots[level + 1] -= 1;
path->slots[level] = orig_slot;
if (mid_buf)
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btrfs_block_release(root, mid_buf);
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} else {
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orig_slot -= btrfs_header_nritems(&left->header);
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path->slots[level] = orig_slot;
}
}
/* double check we haven't messed things up */
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check_block(root, path, level);
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if (orig_ptr != btrfs_node_blockptr(&path->nodes[level]->node,
path->slots[level]))
BUG();
2007-03-01 17:04:21 +00:00
if (right_buf)
2007-03-13 14:46:10 +00:00
btrfs_block_release(root, right_buf);
2007-03-01 17:04:21 +00:00
if (left_buf)
2007-03-13 14:46:10 +00:00
btrfs_block_release(root, left_buf);
2007-03-01 17:04:21 +00:00
return ret;
}
2007-02-02 16:05:29 +00:00
/*
* look for key in the tree. path is filled in with nodes along the way
* if key is found, we return zero and you can find the item in the leaf
* level of the path (level 0)
*
* If the key isn't found, the path points to the slot where it should
2007-02-28 21:35:06 +00:00
* be inserted, and 1 is returned. If there are other errors during the
* search a negative error number is returned.
2007-02-24 18:39:08 +00:00
*
* if ins_len > 0, nodes and leaves will be split as we walk down the
* tree. if ins_len < 0, nodes will be merged as we walk down the tree (if
* possible)
2007-02-02 16:05:29 +00:00
*/
2007-03-16 20:20:31 +00:00
int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root
*root, struct btrfs_key *key, struct btrfs_path *p, int
ins_len, int cow)
{
2007-03-13 14:46:10 +00:00
struct btrfs_buffer *b;
struct btrfs_buffer *cow_buf;
struct btrfs_node *c;
int slot;
int ret;
int level;
2007-02-22 16:39:13 +00:00
2007-03-01 17:04:21 +00:00
again:
b = root->node;
2007-02-02 14:18:22 +00:00
b->count++;
while (b) {
2007-03-12 16:01:18 +00:00
level = btrfs_header_level(&b->node.header);
2007-03-02 21:08:05 +00:00
if (cow) {
int wret;
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wret = btrfs_cow_block(trans, root, b, p->nodes[level +
1], p->slots[level + 1],
&cow_buf);
2007-03-02 21:08:05 +00:00
b = cow_buf;
}
BUG_ON(!cow && ins_len);
2007-02-02 14:18:22 +00:00
c = &b->node;
p->nodes[level] = b;
2007-03-14 18:14:43 +00:00
ret = check_block(root, p, level);
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if (ret)
return -1;
ret = bin_search(c, key, &slot);
2007-03-12 16:01:18 +00:00
if (!btrfs_is_leaf(c)) {
if (ret && slot > 0)
slot -= 1;
p->slots[level] = slot;
2007-03-12 16:01:18 +00:00
if (ins_len > 0 && btrfs_header_nritems(&c->header) ==
2007-03-14 18:14:43 +00:00
BTRFS_NODEPTRS_PER_BLOCK(root)) {
2007-03-16 20:20:31 +00:00
int sret = split_node(trans, root, p, level);
2007-02-22 16:39:13 +00:00
BUG_ON(sret > 0);
if (sret)
return sret;
b = p->nodes[level];
c = &b->node;
slot = p->slots[level];
2007-03-01 17:04:21 +00:00
} else if (ins_len < 0) {
2007-03-16 20:20:31 +00:00
int sret = balance_level(trans, root, p,
level);
2007-03-01 17:04:21 +00:00
if (sret)
return sret;
b = p->nodes[level];
if (!b)
goto again;
c = &b->node;
slot = p->slots[level];
2007-03-12 16:01:18 +00:00
BUG_ON(btrfs_header_nritems(&c->header) == 1);
2007-02-22 16:39:13 +00:00
}
2007-03-13 13:28:32 +00:00
b = read_tree_block(root, btrfs_node_blockptr(c, slot));
} else {
2007-03-13 14:46:10 +00:00
struct btrfs_leaf *l = (struct btrfs_leaf *)c;
p->slots[level] = slot;
2007-03-14 18:14:43 +00:00
if (ins_len > 0 && btrfs_leaf_free_space(root, l) <
2007-03-13 00:12:07 +00:00
sizeof(struct btrfs_item) + ins_len) {
2007-03-16 20:20:31 +00:00
int sret = split_leaf(trans, root, p, ins_len);
2007-02-22 16:39:13 +00:00
BUG_ON(sret > 0);
if (sret)
return sret;
}
2007-03-01 17:04:21 +00:00
BUG_ON(root->node->count == 1);
return ret;
}
}
2007-03-01 17:04:21 +00:00
BUG_ON(root->node->count == 1);
2007-02-28 21:35:06 +00:00
return 1;
}
2007-02-02 16:05:29 +00:00
/*
* adjust the pointers going up the tree, starting at level
* making sure the right key of each node is points to 'key'.
* This is used after shifting pointers to the left, so it stops
* fixing up pointers when a given leaf/node is not in slot 0 of the
* higher levels
2007-02-28 21:35:06 +00:00
*
* If this fails to write a tree block, it returns -1, but continues
* fixing up the blocks in ram so the tree is consistent.
2007-02-02 16:05:29 +00:00
*/
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static int fixup_low_keys(struct btrfs_trans_handle *trans, struct btrfs_root
*root, struct btrfs_path *path, struct btrfs_disk_key
*key, int level)
{
int i;
2007-02-28 21:35:06 +00:00
int ret = 0;
2007-03-13 14:46:10 +00:00
for (i = level; i < BTRFS_MAX_LEVEL; i++) {
struct btrfs_node *t;
int tslot = path->slots[i];
2007-02-02 14:18:22 +00:00
if (!path->nodes[i])
break;
2007-02-02 14:18:22 +00:00
t = &path->nodes[i]->node;
2007-03-14 18:14:43 +00:00
memcpy(&t->ptrs[tslot].key, key, sizeof(*key));
2007-03-02 21:08:05 +00:00
BUG_ON(list_empty(&path->nodes[i]->dirty));
if (tslot != 0)
break;
}
2007-02-28 21:35:06 +00:00
return ret;
}
2007-02-02 16:05:29 +00:00
/*
* try to push data from one node into the next node left in the
* tree.
2007-02-28 21:35:06 +00:00
*
* returns 0 if some ptrs were pushed left, < 0 if there was some horrible
* error, and > 0 if there was no room in the left hand block.
2007-02-02 16:05:29 +00:00
*/
2007-03-16 20:20:31 +00:00
static int push_node_left(struct btrfs_trans_handle *trans, struct btrfs_root
*root, struct btrfs_buffer *dst_buf, struct
btrfs_buffer *src_buf)
{
2007-03-13 14:46:10 +00:00
struct btrfs_node *src = &src_buf->node;
struct btrfs_node *dst = &dst_buf->node;
int push_items = 0;
2007-03-01 17:04:21 +00:00
int src_nritems;
int dst_nritems;
2007-02-28 21:35:06 +00:00
int ret = 0;
2007-03-12 16:01:18 +00:00
src_nritems = btrfs_header_nritems(&src->header);
dst_nritems = btrfs_header_nritems(&dst->header);
2007-03-14 18:14:43 +00:00
push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
2007-02-02 14:18:22 +00:00
if (push_items <= 0) {
return 1;
2007-02-02 14:18:22 +00:00
}
2007-03-01 17:04:21 +00:00
if (src_nritems < push_items)
push_items = src_nritems;
2007-03-14 18:14:43 +00:00
memcpy(dst->ptrs + dst_nritems, src->ptrs,
push_items * sizeof(struct btrfs_key_ptr));
2007-03-01 17:04:21 +00:00
if (push_items < src_nritems) {
2007-03-14 18:14:43 +00:00
memmove(src->ptrs, src->ptrs + push_items,
2007-03-12 20:22:34 +00:00
(src_nritems - push_items) *
2007-03-14 18:14:43 +00:00
sizeof(struct btrfs_key_ptr));
2007-03-01 17:04:21 +00:00
}
2007-03-12 16:01:18 +00:00
btrfs_set_header_nritems(&src->header, src_nritems - push_items);
btrfs_set_header_nritems(&dst->header, dst_nritems + push_items);
2007-03-02 21:08:05 +00:00
BUG_ON(list_empty(&src_buf->dirty));
BUG_ON(list_empty(&dst_buf->dirty));
return ret;
}
/*
* try to push data from one node into the next node right in the
* tree.
*
* returns 0 if some ptrs were pushed, < 0 if there was some horrible
* error, and > 0 if there was no room in the right hand block.
*
* this will only push up to 1/2 the contents of the left node over
*/
2007-03-16 20:20:31 +00:00
static int balance_node_right(struct btrfs_trans_handle *trans, struct
btrfs_root *root, struct btrfs_buffer *dst_buf,
2007-03-13 14:46:10 +00:00
struct btrfs_buffer *src_buf)
{
2007-03-13 14:46:10 +00:00
struct btrfs_node *src = &src_buf->node;
struct btrfs_node *dst = &dst_buf->node;
int push_items = 0;
int max_push;
int src_nritems;
int dst_nritems;
int ret = 0;
2007-03-12 16:01:18 +00:00
src_nritems = btrfs_header_nritems(&src->header);
dst_nritems = btrfs_header_nritems(&dst->header);
2007-03-14 18:14:43 +00:00
push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
if (push_items <= 0) {
return 1;
}
max_push = src_nritems / 2 + 1;
/* don't try to empty the node */
if (max_push > src_nritems)
return 1;
if (max_push < push_items)
push_items = max_push;
2007-03-14 18:14:43 +00:00
memmove(dst->ptrs + push_items, dst->ptrs,
dst_nritems * sizeof(struct btrfs_key_ptr));
memcpy(dst->ptrs, src->ptrs + src_nritems - push_items,
push_items * sizeof(struct btrfs_key_ptr));
2007-03-12 16:01:18 +00:00
btrfs_set_header_nritems(&src->header, src_nritems - push_items);
btrfs_set_header_nritems(&dst->header, dst_nritems + push_items);
2007-03-02 21:08:05 +00:00
BUG_ON(list_empty(&src_buf->dirty));
BUG_ON(list_empty(&dst_buf->dirty));
2007-02-28 21:35:06 +00:00
return ret;
}
2007-02-24 18:39:08 +00:00
/*
* helper function to insert a new root level in the tree.
* A new node is allocated, and a single item is inserted to
* point to the existing root
2007-02-28 21:35:06 +00:00
*
* returns zero on success or < 0 on failure.
2007-02-24 18:39:08 +00:00
*/
2007-03-16 20:20:31 +00:00
static int insert_new_root(struct btrfs_trans_handle *trans, struct btrfs_root
*root, struct btrfs_path *path, int level)
2007-02-22 16:39:13 +00:00
{
2007-03-13 14:46:10 +00:00
struct btrfs_buffer *t;
struct btrfs_node *lower;
struct btrfs_node *c;
2007-03-12 20:22:34 +00:00
struct btrfs_disk_key *lower_key;
2007-02-22 16:39:13 +00:00
BUG_ON(path->nodes[level]);
BUG_ON(path->nodes[level-1] != root->node);
2007-03-16 20:20:31 +00:00
t = btrfs_alloc_free_block(trans, root);
2007-02-22 16:39:13 +00:00
c = &t->node;
2007-03-14 18:14:43 +00:00
memset(c, 0, root->blocksize);
2007-03-12 16:01:18 +00:00
btrfs_set_header_nritems(&c->header, 1);
btrfs_set_header_level(&c->header, level);
btrfs_set_header_blocknr(&c->header, t->blocknr);
btrfs_set_header_owner(&c->header, root->root_key.objectid);
2007-04-26 20:46:06 +00:00
memcpy(c->header.fsid, root->fs_info->disk_super->fsid,
sizeof(c->header.fsid));
2007-02-22 16:39:13 +00:00
lower = &path->nodes[level-1]->node;
2007-03-12 16:01:18 +00:00
if (btrfs_is_leaf(lower))
2007-03-13 14:46:10 +00:00
lower_key = &((struct btrfs_leaf *)lower)->items[0].key;
2007-02-22 16:39:13 +00:00
else
2007-03-14 18:14:43 +00:00
lower_key = &lower->ptrs[0].key;
memcpy(&c->ptrs[0].key, lower_key, sizeof(struct btrfs_disk_key));
2007-03-13 13:28:32 +00:00
btrfs_set_node_blockptr(c, 0, path->nodes[level - 1]->blocknr);
2007-02-22 16:39:13 +00:00
/* the super has an extra ref to root->node */
2007-03-13 14:46:10 +00:00
btrfs_block_release(root, root->node);
2007-02-22 16:39:13 +00:00
root->node = t;
t->count++;
path->nodes[level] = t;
path->slots[level] = 0;
return 0;
}
2007-02-02 16:05:29 +00:00
/*
* worker function to insert a single pointer in a node.
* the node should have enough room for the pointer already
2007-02-24 18:39:08 +00:00
*
2007-02-02 16:05:29 +00:00
* slot and level indicate where you want the key to go, and
* blocknr is the block the key points to.
2007-02-28 21:35:06 +00:00
*
* returns zero on success and < 0 on any error
2007-02-02 16:05:29 +00:00
*/
2007-03-16 20:20:31 +00:00
static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root
*root, struct btrfs_path *path, struct btrfs_disk_key
*key, u64 blocknr, int slot, int level)
2007-02-02 16:05:29 +00:00
{
2007-03-13 14:46:10 +00:00
struct btrfs_node *lower;
2007-02-02 16:05:29 +00:00
int nritems;
2007-02-22 16:39:13 +00:00
BUG_ON(!path->nodes[level]);
2007-02-02 16:05:29 +00:00
lower = &path->nodes[level]->node;
2007-03-12 16:01:18 +00:00
nritems = btrfs_header_nritems(&lower->header);
2007-02-02 16:05:29 +00:00
if (slot > nritems)
BUG();
2007-03-14 18:14:43 +00:00
if (nritems == BTRFS_NODEPTRS_PER_BLOCK(root))
2007-02-02 16:05:29 +00:00
BUG();
if (slot != nritems) {
2007-03-14 18:14:43 +00:00
memmove(lower->ptrs + slot + 1, lower->ptrs + slot,
(nritems - slot) * sizeof(struct btrfs_key_ptr));
2007-02-02 16:05:29 +00:00
}
2007-03-14 18:14:43 +00:00
memcpy(&lower->ptrs[slot].key, key, sizeof(struct btrfs_disk_key));
2007-03-13 13:28:32 +00:00
btrfs_set_node_blockptr(lower, slot, blocknr);
2007-03-12 16:01:18 +00:00
btrfs_set_header_nritems(&lower->header, nritems + 1);
2007-03-02 21:08:05 +00:00
BUG_ON(list_empty(&path->nodes[level]->dirty));
2007-02-02 16:05:29 +00:00
return 0;
}
2007-02-24 18:39:08 +00:00
/*
* split the node at the specified level in path in two.
* The path is corrected to point to the appropriate node after the split
*
* Before splitting this tries to make some room in the node by pushing
* left and right, if either one works, it returns right away.
2007-02-28 21:35:06 +00:00
*
* returns 0 on success and < 0 on failure
2007-02-24 18:39:08 +00:00
*/
2007-03-16 20:20:31 +00:00
static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root
*root, struct btrfs_path *path, int level)
{
2007-03-13 14:46:10 +00:00
struct btrfs_buffer *t;
struct btrfs_node *c;
struct btrfs_buffer *split_buffer;
struct btrfs_node *split;
int mid;
2007-02-22 16:39:13 +00:00
int ret;
2007-02-28 21:35:06 +00:00
int wret;
2007-03-12 16:01:18 +00:00
u32 c_nritems;
2007-02-02 14:18:22 +00:00
2007-02-22 16:39:13 +00:00
t = path->nodes[level];
c = &t->node;
if (t == root->node) {
/* trying to split the root, lets make a new one */
2007-03-16 20:20:31 +00:00
ret = insert_new_root(trans, root, path, level + 1);
2007-02-22 16:39:13 +00:00
if (ret)
return ret;
}
2007-03-12 16:01:18 +00:00
c_nritems = btrfs_header_nritems(&c->header);
2007-03-16 20:20:31 +00:00
split_buffer = btrfs_alloc_free_block(trans, root);
2007-02-22 16:39:13 +00:00
split = &split_buffer->node;
2007-03-12 16:01:18 +00:00
btrfs_set_header_flags(&split->header, btrfs_header_flags(&c->header));
2007-03-27 13:15:24 +00:00
btrfs_set_header_level(&split->header, btrfs_header_level(&c->header));
2007-03-12 16:01:18 +00:00
btrfs_set_header_blocknr(&split->header, split_buffer->blocknr);
btrfs_set_header_owner(&split->header, root->root_key.objectid);
2007-04-26 20:46:06 +00:00
memcpy(split->header.fsid, root->fs_info->disk_super->fsid,
sizeof(split->header.fsid));
2007-03-12 16:01:18 +00:00
mid = (c_nritems + 1) / 2;
2007-03-14 18:14:43 +00:00
memcpy(split->ptrs, c->ptrs + mid,
(c_nritems - mid) * sizeof(struct btrfs_key_ptr));
2007-03-12 16:01:18 +00:00
btrfs_set_header_nritems(&split->header, c_nritems - mid);
btrfs_set_header_nritems(&c->header, mid);
2007-02-28 21:35:06 +00:00
ret = 0;
2007-03-02 21:08:05 +00:00
BUG_ON(list_empty(&t->dirty));
2007-03-16 20:20:31 +00:00
wret = insert_ptr(trans, root, path, &split->ptrs[0].key,
2007-03-14 18:14:43 +00:00
split_buffer->blocknr, path->slots[level + 1] + 1,
level + 1);
2007-02-28 21:35:06 +00:00
if (wret)
ret = wret;
2007-02-24 11:24:44 +00:00
if (path->slots[level] >= mid) {
2007-02-22 16:39:13 +00:00
path->slots[level] -= mid;
2007-03-13 14:46:10 +00:00
btrfs_block_release(root, t);
2007-02-22 16:39:13 +00:00
path->nodes[level] = split_buffer;
path->slots[level + 1] += 1;
} else {
2007-03-13 14:46:10 +00:00
btrfs_block_release(root, split_buffer);
}
2007-02-28 21:35:06 +00:00
return ret;
}
2007-02-24 17:47:20 +00:00
/*
* push some data in the path leaf to the right, trying to free up at
* least data_size bytes. returns zero if the push worked, nonzero otherwise
2007-02-28 21:35:06 +00:00
*
* returns 1 if the push failed because the other node didn't have enough
* room, 0 if everything worked out and < 0 if there were major errors.
2007-02-24 17:47:20 +00:00
*/
2007-03-16 20:20:31 +00:00
static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
*root, struct btrfs_path *path, int data_size)
2007-02-24 17:47:20 +00:00
{
2007-03-13 14:46:10 +00:00
struct btrfs_buffer *left_buf = path->nodes[0];
struct btrfs_leaf *left = &left_buf->leaf;
struct btrfs_leaf *right;
struct btrfs_buffer *right_buf;
struct btrfs_buffer *upper;
2007-02-24 17:47:20 +00:00
int slot;
int i;
int free_space;
int push_space = 0;
int push_items = 0;
2007-03-13 00:12:07 +00:00
struct btrfs_item *item;
2007-03-12 16:01:18 +00:00
u32 left_nritems;
u32 right_nritems;
2007-02-24 17:47:20 +00:00
slot = path->slots[1];
if (!path->nodes[1]) {
return 1;
}
upper = path->nodes[1];
2007-03-12 16:01:18 +00:00
if (slot >= btrfs_header_nritems(&upper->node.header) - 1) {
2007-02-24 17:47:20 +00:00
return 1;
}
2007-03-13 13:28:32 +00:00
right_buf = read_tree_block(root, btrfs_node_blockptr(&upper->node,
slot + 1));
2007-02-24 17:47:20 +00:00
right = &right_buf->leaf;
2007-03-14 18:14:43 +00:00
free_space = btrfs_leaf_free_space(root, right);
2007-03-13 00:12:07 +00:00
if (free_space < data_size + sizeof(struct btrfs_item)) {
2007-03-13 14:46:10 +00:00
btrfs_block_release(root, right_buf);
2007-02-24 17:47:20 +00:00
return 1;
}
2007-03-02 21:08:05 +00:00
/* cow and double check */
2007-03-16 20:20:31 +00:00
btrfs_cow_block(trans, root, right_buf, upper, slot + 1, &right_buf);
2007-03-02 21:08:05 +00:00
right = &right_buf->leaf;
2007-03-14 18:14:43 +00:00
free_space = btrfs_leaf_free_space(root, right);
2007-03-13 00:12:07 +00:00
if (free_space < data_size + sizeof(struct btrfs_item)) {
2007-03-13 14:46:10 +00:00
btrfs_block_release(root, right_buf);
2007-03-02 21:08:05 +00:00
return 1;
}
2007-03-12 16:01:18 +00:00
left_nritems = btrfs_header_nritems(&left->header);
for (i = left_nritems - 1; i >= 0; i--) {
2007-02-24 17:47:20 +00:00
item = left->items + i;
if (path->slots[0] == i)
push_space += data_size + sizeof(*item);
2007-03-13 00:12:07 +00:00
if (btrfs_item_size(item) + sizeof(*item) + push_space >
free_space)
2007-02-24 17:47:20 +00:00
break;
push_items++;
2007-03-13 00:12:07 +00:00
push_space += btrfs_item_size(item) + sizeof(*item);
2007-02-24 17:47:20 +00:00
}
if (push_items == 0) {
2007-03-13 14:46:10 +00:00
btrfs_block_release(root, right_buf);
2007-02-24 17:47:20 +00:00
return 1;
}
2007-03-12 16:01:18 +00:00
right_nritems = btrfs_header_nritems(&right->header);
2007-02-24 17:47:20 +00:00
/* push left to right */
2007-03-13 00:12:07 +00:00
push_space = btrfs_item_end(left->items + left_nritems - push_items);
2007-03-14 18:14:43 +00:00
push_space -= leaf_data_end(root, left);
2007-02-24 17:47:20 +00:00
/* make room in the right data area */
2007-03-14 18:14:43 +00:00
memmove(btrfs_leaf_data(right) + leaf_data_end(root, right) -
push_space, btrfs_leaf_data(right) + leaf_data_end(root, right),
BTRFS_LEAF_DATA_SIZE(root) - leaf_data_end(root, right));
2007-02-24 17:47:20 +00:00
/* copy from the left data area */
2007-03-14 18:14:43 +00:00
memcpy(btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) - push_space,
btrfs_leaf_data(left) + leaf_data_end(root, left), push_space);
2007-02-24 17:47:20 +00:00
memmove(right->items + push_items, right->items,
2007-03-13 00:12:07 +00:00
right_nritems * sizeof(struct btrfs_item));
2007-02-24 17:47:20 +00:00
/* copy the items from left to right */
2007-03-12 16:01:18 +00:00
memcpy(right->items, left->items + left_nritems - push_items,
2007-03-13 00:12:07 +00:00
push_items * sizeof(struct btrfs_item));
2007-02-24 17:47:20 +00:00
/* update the item pointers */
2007-03-12 16:01:18 +00:00
right_nritems += push_items;
btrfs_set_header_nritems(&right->header, right_nritems);
2007-03-14 18:14:43 +00:00
push_space = BTRFS_LEAF_DATA_SIZE(root);
2007-03-12 16:01:18 +00:00
for (i = 0; i < right_nritems; i++) {
2007-03-13 00:12:07 +00:00
btrfs_set_item_offset(right->items + i, push_space -
btrfs_item_size(right->items + i));
push_space = btrfs_item_offset(right->items + i);
2007-02-24 17:47:20 +00:00
}
2007-03-12 16:01:18 +00:00
left_nritems -= push_items;
btrfs_set_header_nritems(&left->header, left_nritems);
2007-02-24 17:47:20 +00:00
2007-03-02 21:08:05 +00:00
BUG_ON(list_empty(&left_buf->dirty));
BUG_ON(list_empty(&right_buf->dirty));
2007-03-14 18:14:43 +00:00
memcpy(&upper->node.ptrs[slot + 1].key,
2007-03-12 20:22:34 +00:00
&right->items[0].key, sizeof(struct btrfs_disk_key));
2007-03-02 21:08:05 +00:00
BUG_ON(list_empty(&upper->dirty));
2007-02-24 17:47:20 +00:00
/* then fixup the leaf pointer in the path */
2007-03-12 16:01:18 +00:00
if (path->slots[0] >= left_nritems) {
path->slots[0] -= left_nritems;
2007-03-13 14:46:10 +00:00
btrfs_block_release(root, path->nodes[0]);
2007-02-24 17:47:20 +00:00
path->nodes[0] = right_buf;
path->slots[1] += 1;
} else {
2007-03-13 14:46:10 +00:00
btrfs_block_release(root, right_buf);
2007-02-24 17:47:20 +00:00
}
return 0;
}
2007-02-02 16:05:29 +00:00
/*
* push some data in the path leaf to the left, trying to free up at
* least data_size bytes. returns zero if the push worked, nonzero otherwise
*/
2007-03-16 20:20:31 +00:00
static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
*root, struct btrfs_path *path, int data_size)
{
2007-03-13 14:46:10 +00:00
struct btrfs_buffer *right_buf = path->nodes[0];
struct btrfs_leaf *right = &right_buf->leaf;
struct btrfs_buffer *t;
struct btrfs_leaf *left;
int slot;
int i;
int free_space;
int push_space = 0;
int push_items = 0;
2007-03-13 00:12:07 +00:00
struct btrfs_item *item;
2007-03-12 16:01:18 +00:00
u32 old_left_nritems;
2007-02-28 21:35:06 +00:00
int ret = 0;
int wret;
slot = path->slots[1];
if (slot == 0) {
return 1;
}
if (!path->nodes[1]) {
return 1;
}
2007-03-13 13:28:32 +00:00
t = read_tree_block(root, btrfs_node_blockptr(&path->nodes[1]->node,
slot - 1));
2007-02-02 14:18:22 +00:00
left = &t->leaf;
2007-03-14 18:14:43 +00:00
free_space = btrfs_leaf_free_space(root, left);
2007-03-13 00:12:07 +00:00
if (free_space < data_size + sizeof(struct btrfs_item)) {
2007-03-13 14:46:10 +00:00
btrfs_block_release(root, t);
return 1;
}
2007-03-02 21:08:05 +00:00
/* cow and double check */
2007-03-16 20:20:31 +00:00
btrfs_cow_block(trans, root, t, path->nodes[1], slot - 1, &t);
2007-03-02 21:08:05 +00:00
left = &t->leaf;
2007-03-14 18:14:43 +00:00
free_space = btrfs_leaf_free_space(root, left);
2007-03-13 00:12:07 +00:00
if (free_space < data_size + sizeof(struct btrfs_item)) {
2007-03-13 14:46:10 +00:00
btrfs_block_release(root, t);
2007-03-02 21:08:05 +00:00
return 1;
}
2007-03-12 16:01:18 +00:00
for (i = 0; i < btrfs_header_nritems(&right->header); i++) {
item = right->items + i;
if (path->slots[0] == i)
push_space += data_size + sizeof(*item);
2007-03-13 00:12:07 +00:00
if (btrfs_item_size(item) + sizeof(*item) + push_space >
free_space)
break;
push_items++;
2007-03-13 00:12:07 +00:00
push_space += btrfs_item_size(item) + sizeof(*item);
}
if (push_items == 0) {
2007-03-13 14:46:10 +00:00
btrfs_block_release(root, t);
return 1;
}
/* push data from right to left */
2007-03-12 16:01:18 +00:00
memcpy(left->items + btrfs_header_nritems(&left->header),
2007-03-13 00:12:07 +00:00
right->items, push_items * sizeof(struct btrfs_item));
2007-03-14 18:14:43 +00:00
push_space = BTRFS_LEAF_DATA_SIZE(root) -
2007-03-13 00:12:07 +00:00
btrfs_item_offset(right->items + push_items -1);
2007-03-14 18:14:43 +00:00
memcpy(btrfs_leaf_data(left) + leaf_data_end(root, left) - push_space,
btrfs_leaf_data(right) +
btrfs_item_offset(right->items + push_items - 1),
push_space);
2007-03-12 16:01:18 +00:00
old_left_nritems = btrfs_header_nritems(&left->header);
2007-02-02 14:18:22 +00:00
BUG_ON(old_left_nritems < 0);
2007-03-13 00:12:07 +00:00
for (i = old_left_nritems; i < old_left_nritems + push_items; i++) {
2007-03-14 18:14:43 +00:00
u32 ioff = btrfs_item_offset(left->items + i);
btrfs_set_item_offset(left->items + i, ioff -
(BTRFS_LEAF_DATA_SIZE(root) -
2007-03-13 00:12:07 +00:00
btrfs_item_offset(left->items +
old_left_nritems - 1)));
}
2007-03-12 16:01:18 +00:00
btrfs_set_header_nritems(&left->header, old_left_nritems + push_items);
/* fixup right node */
2007-03-13 00:12:07 +00:00
push_space = btrfs_item_offset(right->items + push_items - 1) -
2007-03-14 18:14:43 +00:00
leaf_data_end(root, right);
memmove(btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) -
push_space, btrfs_leaf_data(right) +
leaf_data_end(root, right), push_space);
memmove(right->items, right->items + push_items,
2007-03-12 16:01:18 +00:00
(btrfs_header_nritems(&right->header) - push_items) *
2007-03-13 00:12:07 +00:00
sizeof(struct btrfs_item));
2007-03-12 16:01:18 +00:00
btrfs_set_header_nritems(&right->header,
btrfs_header_nritems(&right->header) -
push_items);
2007-03-14 18:14:43 +00:00
push_space = BTRFS_LEAF_DATA_SIZE(root);
2007-02-02 14:18:22 +00:00
2007-03-12 16:01:18 +00:00
for (i = 0; i < btrfs_header_nritems(&right->header); i++) {
2007-03-13 00:12:07 +00:00
btrfs_set_item_offset(right->items + i, push_space -
btrfs_item_size(right->items + i));
push_space = btrfs_item_offset(right->items + i);
}
2007-02-02 14:18:22 +00:00
2007-03-02 21:08:05 +00:00
BUG_ON(list_empty(&t->dirty));
BUG_ON(list_empty(&right_buf->dirty));
2007-02-02 14:18:22 +00:00
2007-03-16 20:20:31 +00:00
wret = fixup_low_keys(trans, root, path, &right->items[0].key, 1);
2007-02-28 21:35:06 +00:00
if (wret)
ret = wret;
/* then fixup the leaf pointer in the path */
if (path->slots[0] < push_items) {
path->slots[0] += old_left_nritems;
2007-03-13 14:46:10 +00:00
btrfs_block_release(root, path->nodes[0]);
2007-02-02 14:18:22 +00:00
path->nodes[0] = t;
path->slots[1] -= 1;
} else {
2007-03-13 14:46:10 +00:00
btrfs_block_release(root, t);
path->slots[0] -= push_items;
}
2007-02-02 14:18:22 +00:00
BUG_ON(path->slots[0] < 0);
2007-02-28 21:35:06 +00:00
return ret;
}
2007-02-02 16:05:29 +00:00
/*
* split the path's leaf in two, making sure there is at least data_size
* available for the resulting leaf level of the path.
2007-02-28 21:35:06 +00:00
*
* returns 0 if all went well and < 0 on failure.
2007-02-02 16:05:29 +00:00
*/
2007-03-16 20:20:31 +00:00
static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
*root, struct btrfs_path *path, int data_size)
{
2007-03-13 14:46:10 +00:00
struct btrfs_buffer *l_buf;
struct btrfs_leaf *l;
2007-03-12 16:01:18 +00:00
u32 nritems;
2007-02-02 14:18:22 +00:00
int mid;
int slot;
2007-03-13 14:46:10 +00:00
struct btrfs_leaf *right;
struct btrfs_buffer *right_buffer;
2007-03-13 00:12:07 +00:00
int space_needed = data_size + sizeof(struct btrfs_item);
int data_copy_size;
int rt_data_off;
int i;
int ret;
2007-02-28 21:35:06 +00:00
int wret;
2007-03-17 18:29:23 +00:00
/* first try to make some room by pushing left and right */
2007-03-16 20:20:31 +00:00
wret = push_leaf_left(trans, root, path, data_size);
2007-03-13 15:17:52 +00:00
if (wret < 0)
return wret;
if (wret) {
2007-03-16 20:20:31 +00:00
wret = push_leaf_right(trans, root, path, data_size);
2007-03-13 15:17:52 +00:00
if (wret < 0)
return wret;
}
2007-02-28 21:35:06 +00:00
l_buf = path->nodes[0];
l = &l_buf->leaf;
/* did the pushes work? */
2007-03-14 18:14:43 +00:00
if (btrfs_leaf_free_space(root, l) >=
sizeof(struct btrfs_item) + data_size)
2007-02-28 21:35:06 +00:00
return 0;
2007-02-22 16:39:13 +00:00
if (!path->nodes[1]) {
2007-03-16 20:20:31 +00:00
ret = insert_new_root(trans, root, path, 1);
2007-02-22 16:39:13 +00:00
if (ret)
return ret;
}
2007-02-02 14:18:22 +00:00
slot = path->slots[0];
2007-03-12 16:01:18 +00:00
nritems = btrfs_header_nritems(&l->header);
2007-02-02 14:18:22 +00:00
mid = (nritems + 1)/ 2;
2007-03-16 20:20:31 +00:00
right_buffer = btrfs_alloc_free_block(trans, root);
2007-02-02 14:18:22 +00:00
BUG_ON(!right_buffer);
BUG_ON(mid == nritems);
right = &right_buffer->leaf;
2007-03-14 18:14:43 +00:00
memset(&right->header, 0, sizeof(right->header));
if (mid <= slot) {
2007-02-24 18:39:08 +00:00
/* FIXME, just alloc a new leaf here */
if (leaf_space_used(l, mid, nritems - mid) + space_needed >
2007-03-14 18:14:43 +00:00
BTRFS_LEAF_DATA_SIZE(root))
BUG();
} else {
2007-02-24 18:39:08 +00:00
/* FIXME, just alloc a new leaf here */
if (leaf_space_used(l, 0, mid + 1) + space_needed >
2007-03-14 18:14:43 +00:00
BTRFS_LEAF_DATA_SIZE(root))
BUG();
}
2007-03-12 16:01:18 +00:00
btrfs_set_header_nritems(&right->header, nritems - mid);
btrfs_set_header_blocknr(&right->header, right_buffer->blocknr);
btrfs_set_header_level(&right->header, 0);
btrfs_set_header_owner(&right->header, root->root_key.objectid);
2007-04-26 20:46:06 +00:00
memcpy(right->header.fsid, root->fs_info->disk_super->fsid,
sizeof(right->header.fsid));
2007-03-14 18:14:43 +00:00
data_copy_size = btrfs_item_end(l->items + mid) -
leaf_data_end(root, l);
memcpy(right->items, l->items + mid,
2007-03-13 00:12:07 +00:00
(nritems - mid) * sizeof(struct btrfs_item));
2007-03-14 18:14:43 +00:00
memcpy(btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) -
data_copy_size, btrfs_leaf_data(l) +
leaf_data_end(root, l), data_copy_size);
rt_data_off = BTRFS_LEAF_DATA_SIZE(root) -
btrfs_item_end(l->items + mid);
2007-02-02 16:05:29 +00:00
2007-03-13 00:12:07 +00:00
for (i = 0; i < btrfs_header_nritems(&right->header); i++) {
2007-03-14 18:14:43 +00:00
u32 ioff = btrfs_item_offset(right->items + i);
2007-03-13 00:12:07 +00:00
btrfs_set_item_offset(right->items + i, ioff + rt_data_off);
}
2007-02-02 16:05:29 +00:00
2007-03-12 16:01:18 +00:00
btrfs_set_header_nritems(&l->header, mid);
2007-02-28 21:35:06 +00:00
ret = 0;
2007-03-16 20:20:31 +00:00
wret = insert_ptr(trans, root, path, &right->items[0].key,
2007-02-22 16:39:13 +00:00
right_buffer->blocknr, path->slots[1] + 1, 1);
2007-02-28 21:35:06 +00:00
if (wret)
ret = wret;
2007-03-02 21:08:05 +00:00
BUG_ON(list_empty(&right_buffer->dirty));
BUG_ON(list_empty(&l_buf->dirty));
2007-02-02 14:18:22 +00:00
BUG_ON(path->slots[0] != slot);
if (mid <= slot) {
2007-03-13 14:46:10 +00:00
btrfs_block_release(root, path->nodes[0]);
2007-02-02 14:18:22 +00:00
path->nodes[0] = right_buffer;
path->slots[0] -= mid;
path->slots[1] += 1;
2007-02-02 14:18:22 +00:00
} else
2007-03-13 14:46:10 +00:00
btrfs_block_release(root, right_buffer);
2007-02-02 14:18:22 +00:00
BUG_ON(path->slots[0] < 0);
return ret;
}
2007-02-02 16:05:29 +00:00
/*
* Given a key and some data, insert an item into the tree.
* This does all the path init required, making room in the tree if needed.
*/
2007-03-16 20:20:31 +00:00
int btrfs_insert_empty_item(struct btrfs_trans_handle *trans, struct btrfs_root
*root, struct btrfs_path *path, struct btrfs_key
*cpu_key, u32 data_size)
{
2007-02-28 21:35:06 +00:00
int ret = 0;
int slot;
2007-02-02 14:18:22 +00:00
int slot_orig;
2007-03-13 14:46:10 +00:00
struct btrfs_leaf *leaf;
struct btrfs_buffer *leaf_buf;
2007-03-12 16:01:18 +00:00
u32 nritems;
unsigned int data_end;
2007-03-12 20:22:34 +00:00
struct btrfs_disk_key disk_key;
btrfs_cpu_key_to_disk(&disk_key, cpu_key);
2007-02-02 16:05:29 +00:00
/* create a root if there isn't one */
2007-02-22 16:39:13 +00:00
if (!root->node)
2007-02-21 22:04:57 +00:00
BUG();
2007-03-16 20:20:31 +00:00
ret = btrfs_search_slot(trans, root, cpu_key, path, data_size, 1);
2007-02-02 14:18:22 +00:00
if (ret == 0) {
return -EEXIST;
2007-02-28 21:35:06 +00:00
}
2007-03-01 23:59:40 +00:00
if (ret < 0)
goto out;
slot_orig = path->slots[0];
leaf_buf = path->nodes[0];
2007-02-02 14:18:22 +00:00
leaf = &leaf_buf->leaf;
2007-02-02 16:05:29 +00:00
2007-03-12 16:01:18 +00:00
nritems = btrfs_header_nritems(&leaf->header);
2007-03-14 18:14:43 +00:00
data_end = leaf_data_end(root, leaf);
2007-02-02 14:18:22 +00:00
2007-03-14 18:14:43 +00:00
if (btrfs_leaf_free_space(root, leaf) <
2007-03-13 14:46:10 +00:00
sizeof(struct btrfs_item) + data_size)
BUG();
slot = path->slots[0];
2007-02-02 14:18:22 +00:00
BUG_ON(slot < 0);
if (slot != nritems) {
int i;
2007-03-13 00:12:07 +00:00
unsigned int old_data = btrfs_item_end(leaf->items + slot);
/*
* item0..itemN ... dataN.offset..dataN.size .. data0.size
*/
/* first correct the data pointers */
2007-03-13 00:12:07 +00:00
for (i = slot; i < nritems; i++) {
2007-03-14 18:14:43 +00:00
u32 ioff = btrfs_item_offset(leaf->items + i);
2007-03-13 00:12:07 +00:00
btrfs_set_item_offset(leaf->items + i,
ioff - data_size);
}
/* shift the items */
memmove(leaf->items + slot + 1, leaf->items + slot,
2007-03-13 00:12:07 +00:00
(nritems - slot) * sizeof(struct btrfs_item));
/* shift the data */
2007-03-14 18:14:43 +00:00
memmove(btrfs_leaf_data(leaf) + data_end - data_size,
btrfs_leaf_data(leaf) +
data_end, old_data - data_end);
data_end = old_data;
}
/* setup the item for the new data */
2007-03-12 20:22:34 +00:00
memcpy(&leaf->items[slot].key, &disk_key,
sizeof(struct btrfs_disk_key));
2007-03-13 00:12:07 +00:00
btrfs_set_item_offset(leaf->items + slot, data_end - data_size);
btrfs_set_item_size(leaf->items + slot, data_size);
2007-03-12 16:01:18 +00:00
btrfs_set_header_nritems(&leaf->header, nritems + 1);
2007-02-28 21:35:06 +00:00
ret = 0;
if (slot == 0)
2007-03-16 20:20:31 +00:00
ret = fixup_low_keys(trans, root, path, &disk_key, 1);
2007-02-28 21:35:06 +00:00
2007-03-02 21:08:05 +00:00
BUG_ON(list_empty(&leaf_buf->dirty));
2007-03-14 18:14:43 +00:00
if (btrfs_leaf_free_space(root, leaf) < 0)
BUG();
check_leaf(root, path, 0);
2007-03-01 23:59:40 +00:00
out:
return ret;
}
/*
* Given a key and some data, insert an item into the tree.
* This does all the path init required, making room in the tree if needed.
*/
2007-03-16 20:20:31 +00:00
int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root
*root, struct btrfs_key *cpu_key, void *data, u32
data_size)
{
int ret = 0;
struct btrfs_path path;
u8 *ptr;
btrfs_init_path(&path);
2007-03-16 20:20:31 +00:00
ret = btrfs_insert_empty_item(trans, root, &path, cpu_key, data_size);
if (!ret) {
ptr = btrfs_item_ptr(&path.nodes[0]->leaf, path.slots[0], u8);
memcpy(ptr, data, data_size);
}
2007-03-13 14:46:10 +00:00
btrfs_release_path(root, &path);
2007-02-28 21:35:06 +00:00
return ret;
}
2007-02-02 16:05:29 +00:00
/*
2007-02-24 11:24:44 +00:00
* delete the pointer from a given node.
2007-02-02 16:05:29 +00:00
*
* If the delete empties a node, the node is removed from the tree,
* continuing all the way the root if required. The root is converted into
* a leaf if all the nodes are emptied.
*/
2007-03-16 20:20:31 +00:00
static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
struct btrfs_path *path, int level, int slot)
{
2007-03-13 14:46:10 +00:00
struct btrfs_node *node;
struct btrfs_buffer *parent = path->nodes[level];
2007-03-12 16:01:18 +00:00
u32 nritems;
2007-02-28 21:35:06 +00:00
int ret = 0;
2007-03-01 17:04:21 +00:00
int wret;
2007-03-01 17:04:21 +00:00
node = &parent->node;
2007-03-12 16:01:18 +00:00
nritems = btrfs_header_nritems(&node->header);
2007-03-01 17:04:21 +00:00
if (slot != nritems -1) {
2007-03-14 18:14:43 +00:00
memmove(node->ptrs + slot, node->ptrs + slot + 1,
sizeof(struct btrfs_key_ptr) * (nritems - slot - 1));
2007-03-01 17:04:21 +00:00
}
2007-03-12 16:01:18 +00:00
nritems--;
btrfs_set_header_nritems(&node->header, nritems);
if (nritems == 0 && parent == root->node) {
BUG_ON(btrfs_header_level(&root->node->node.header) != 1);
2007-03-01 17:04:21 +00:00
/* just turn the root into a leaf and break */
2007-03-12 16:01:18 +00:00
btrfs_set_header_level(&root->node->node.header, 0);
2007-03-01 17:04:21 +00:00
} else if (slot == 0) {
2007-03-16 20:20:31 +00:00
wret = fixup_low_keys(trans, root, path, &node->ptrs[0].key,
2007-03-14 18:14:43 +00:00
level + 1);
2007-02-28 21:46:22 +00:00
if (wret)
ret = wret;
}
2007-03-02 21:08:05 +00:00
BUG_ON(list_empty(&parent->dirty));
2007-02-28 21:35:06 +00:00
return ret;
}
2007-02-02 16:05:29 +00:00
/*
* delete the item at the leaf level in path. If that empties
* the leaf, remove it from the tree
*/
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int btrfs_del_item(struct btrfs_trans_handle *trans, struct btrfs_root *root,
struct btrfs_path *path)
{
int slot;
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struct btrfs_leaf *leaf;
struct btrfs_buffer *leaf_buf;
int doff;
int dsize;
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int ret = 0;
int wret;
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u32 nritems;
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leaf_buf = path->nodes[0];
leaf = &leaf_buf->leaf;
slot = path->slots[0];
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doff = btrfs_item_offset(leaf->items + slot);
dsize = btrfs_item_size(leaf->items + slot);
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nritems = btrfs_header_nritems(&leaf->header);
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if (slot != nritems - 1) {
int i;
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int data_end = leaf_data_end(root, leaf);
memmove(btrfs_leaf_data(leaf) + data_end + dsize,
btrfs_leaf_data(leaf) + data_end,
doff - data_end);
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for (i = slot + 1; i < nritems; i++) {
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u32 ioff = btrfs_item_offset(leaf->items + i);
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btrfs_set_item_offset(leaf->items + i, ioff + dsize);
}
memmove(leaf->items + slot, leaf->items + slot + 1,
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sizeof(struct btrfs_item) *
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(nritems - slot - 1));
}
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btrfs_set_header_nritems(&leaf->header, nritems - 1);
nritems--;
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/* delete the leaf if we've emptied it */
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if (nritems == 0) {
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if (leaf_buf == root->node) {
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btrfs_set_header_level(&leaf->header, 0);
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BUG_ON(list_empty(&leaf_buf->dirty));
} else {
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clean_tree_block(trans, root, leaf_buf);
wret = del_ptr(trans, root, path, 1, path->slots[1]);
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if (wret)
ret = wret;
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wret = btrfs_free_extent(trans, root,
leaf_buf->blocknr, 1, 1);
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if (wret)
ret = wret;
}
} else {
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int used = leaf_space_used(leaf, 0, nritems);
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if (slot == 0) {
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wret = fixup_low_keys(trans, root, path,
&leaf->items[0].key, 1);
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if (wret)
ret = wret;
}
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BUG_ON(list_empty(&leaf_buf->dirty));
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/* delete the leaf if it is mostly empty */
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if (used < BTRFS_LEAF_DATA_SIZE(root) / 3) {
/* push_leaf_left fixes the path.
* make sure the path still points to our leaf
* for possible call to del_ptr below
*/
slot = path->slots[1];
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leaf_buf->count++;
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wret = push_leaf_left(trans, root, path, 1);
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if (wret < 0)
ret = wret;
if (path->nodes[0] == leaf_buf &&
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btrfs_header_nritems(&leaf->header)) {
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wret = push_leaf_right(trans, root, path, 1);
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if (wret < 0)
ret = wret;
}
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if (btrfs_header_nritems(&leaf->header) == 0) {
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u64 blocknr = leaf_buf->blocknr;
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clean_tree_block(trans, root, leaf_buf);
wret = del_ptr(trans, root, path, 1, slot);
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if (wret)
ret = wret;
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btrfs_block_release(root, leaf_buf);
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wret = btrfs_free_extent(trans, root, blocknr,
1, 1);
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if (wret)
ret = wret;
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} else {
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btrfs_block_release(root, leaf_buf);
}
}
}
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return ret;
}
int btrfs_extend_item(struct btrfs_trans_handle *trans, struct btrfs_root
*root, struct btrfs_path *path, u32 data_size)
{
int ret = 0;
int slot;
int slot_orig;
struct btrfs_leaf *leaf;
struct btrfs_buffer *leaf_buf;
u32 nritems;
unsigned int data_end;
unsigned int old_data;
unsigned int old_size;
int i;
slot_orig = path->slots[0];
leaf_buf = path->nodes[0];
leaf = &leaf_buf->leaf;
nritems = btrfs_header_nritems(&leaf->header);
data_end = leaf_data_end(root, leaf);
if (btrfs_leaf_free_space(root, leaf) < data_size)
BUG();
slot = path->slots[0];
old_data = btrfs_item_end(leaf->items + slot);
BUG_ON(slot < 0);
BUG_ON(slot >= nritems);
/*
* item0..itemN ... dataN.offset..dataN.size .. data0.size
*/
/* first correct the data pointers */
for (i = slot; i < nritems; i++) {
u32 ioff = btrfs_item_offset(leaf->items + i);
btrfs_set_item_offset(leaf->items + i,
ioff - data_size);
}
/* shift the data */
memmove(btrfs_leaf_data(leaf) + data_end - data_size,
btrfs_leaf_data(leaf) + data_end, old_data - data_end);
data_end = old_data;
old_size = btrfs_item_size(leaf->items + slot);
btrfs_set_item_size(leaf->items + slot, old_size + data_size);
ret = 0;
if (btrfs_leaf_free_space(root, leaf) < 0)
BUG();
check_leaf(root, path, 0);
return ret;
}
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/*
* walk up the tree as far as required to find the next leaf.
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* returns 0 if it found something or 1 if there are no greater leaves.
* returns < 0 on io errors.
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*/
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int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path)
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{
int slot;
int level = 1;
u64 blocknr;
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struct btrfs_buffer *c;
struct btrfs_buffer *next = NULL;
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while(level < BTRFS_MAX_LEVEL) {
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if (!path->nodes[level])
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return 1;
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slot = path->slots[level] + 1;
c = path->nodes[level];
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if (slot >= btrfs_header_nritems(&c->node.header)) {
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level++;
continue;
}
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blocknr = btrfs_node_blockptr(&c->node, slot);
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if (next)
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btrfs_block_release(root, next);
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next = read_tree_block(root, blocknr);
break;
}
path->slots[level] = slot;
while(1) {
level--;
c = path->nodes[level];
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btrfs_block_release(root, c);
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path->nodes[level] = next;
path->slots[level] = 0;
if (!level)
break;
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next = read_tree_block(root,
btrfs_node_blockptr(&next->node, 0));
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}
return 0;
}