1383 lines
38 KiB
C
1383 lines
38 KiB
C
#include <stdio.h>
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#include <stdlib.h>
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#include "kerncompat.h"
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#include "radix-tree.h"
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#include "ctree.h"
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#include "disk-io.h"
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#include "print-tree.h"
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static int split_node(struct btrfs_root *root, struct btrfs_path *path,
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int level);
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static int split_leaf(struct btrfs_root *root, struct btrfs_path *path,
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int data_size);
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static int push_node_left(struct btrfs_root *root, struct btrfs_buffer *dst,
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struct btrfs_buffer *src);
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static int balance_node_right(struct btrfs_root *root,
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struct btrfs_buffer *dst_buf,
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struct btrfs_buffer *src_buf);
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static int del_ptr(struct btrfs_root *root, struct btrfs_path *path, int level,
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int slot);
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inline void btrfs_init_path(struct btrfs_path *p)
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{
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memset(p, 0, sizeof(*p));
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}
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void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p)
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{
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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])
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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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int btrfs_cow_block(struct btrfs_root *root,
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struct btrfs_buffer *buf,
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struct btrfs_buffer *parent,
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int parent_slot,
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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)) {
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*cow_ret = buf;
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return 0;
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}
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cow = btrfs_alloc_free_block(root);
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memcpy(&cow->node, &buf->node, sizeof(buf->node));
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btrfs_set_header_blocknr(&cow->node.header, cow->blocknr);
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*cow_ret = cow;
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btrfs_inc_ref(root, buf);
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if (buf == root->node) {
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root->node = cow;
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cow->count++;
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if (buf != root->commit_root)
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btrfs_free_extent(root, buf->blocknr, 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,
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cow->blocknr);
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BUG_ON(list_empty(&parent->dirty));
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btrfs_free_extent(root, buf->blocknr, 1);
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}
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btrfs_block_release(root, buf);
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return 0;
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}
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/*
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* The leaf data grows from end-to-front in the node.
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* this returns the address of the start of the last item,
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* which is the stop of the leaf data stack
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*/
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static inline unsigned int leaf_data_end(struct btrfs_leaf *leaf)
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{
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u32 nr = btrfs_header_nritems(&leaf->header);
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if (nr == 0)
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return sizeof(leaf->data);
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return btrfs_item_offset(leaf->items + nr - 1);
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}
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/*
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* The space between the end of the leaf items and
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* the start of the leaf data. IOW, how much room
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* the leaf has left for both items and data
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*/
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int btrfs_leaf_free_space(struct btrfs_leaf *leaf)
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{
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int data_end = leaf_data_end(leaf);
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int nritems = btrfs_header_nritems(&leaf->header);
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char *items_end = (char *)(leaf->items + nritems + 1);
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return (char *)(leaf->data + data_end) - (char *)items_end;
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}
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/*
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* compare two keys in a memcmp fashion
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*/
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int comp_keys(struct btrfs_disk_key *disk, struct btrfs_key *k2)
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{
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struct btrfs_key k1;
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btrfs_disk_key_to_cpu(&k1, disk);
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if (k1.objectid > k2->objectid)
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return 1;
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if (k1.objectid < k2->objectid)
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return -1;
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if (k1.flags > k2->flags)
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return 1;
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if (k1.flags < k2->flags)
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return -1;
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if (k1.offset > k2->offset)
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return 1;
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if (k1.offset < k2->offset)
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return -1;
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return 0;
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}
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int check_node(struct btrfs_path *path, int level)
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{
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int i;
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struct btrfs_node *parent = NULL;
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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])
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parent = &path->nodes[level + 1]->node;
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parent_slot = path->slots[level + 1];
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BUG_ON(nritems == 0);
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if (parent) {
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struct btrfs_disk_key *parent_key;
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parent_key = &parent->keys[parent_slot];
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BUG_ON(memcmp(parent_key, node->keys,
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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 > NODEPTRS_PER_BLOCK);
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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->keys[i + 1]);
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BUG_ON(comp_keys(&node->keys[i], &cpukey) >= 0);
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}
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return 0;
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}
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int check_leaf(struct btrfs_path *path, int level)
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{
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int i;
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struct btrfs_leaf *leaf = &path->nodes[level]->leaf;
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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])
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parent = &path->nodes[level + 1]->node;
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parent_slot = path->slots[level + 1];
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BUG_ON(btrfs_leaf_free_space(leaf) < 0);
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if (nritems == 0)
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return 0;
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if (parent) {
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struct btrfs_disk_key *parent_key;
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parent_key = &parent->keys[parent_slot];
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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;
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btrfs_disk_key_to_cpu(&cpukey, &leaf->items[i + 1].key);
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BUG_ON(comp_keys(&leaf->items[i].key,
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&cpukey) >= 0);
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BUG_ON(btrfs_item_offset(leaf->items + i) !=
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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) +
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btrfs_item_size(leaf->items + i) !=
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LEAF_DATA_SIZE);
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}
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}
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return 0;
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}
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int check_block(struct btrfs_path *path, int level)
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{
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if (level == 0)
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return check_leaf(path, level);
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return check_node(path, level);
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}
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/*
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* search for key in the array p. items p are item_size apart
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* and there are 'max' items in p
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* the slot in the array is returned via slot, and it points to
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* the place where you would insert key if it is not found in
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* the array.
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*
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* slot may point to max if the key is bigger than all of the keys
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*/
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int generic_bin_search(char *p, int item_size, struct btrfs_key *key,
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int max, int *slot)
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{
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int low = 0;
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int high = max;
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int mid;
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int ret;
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struct btrfs_disk_key *tmp;
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while(low < high) {
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mid = (low + high) / 2;
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tmp = (struct btrfs_disk_key *)(p + mid * item_size);
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ret = comp_keys(tmp, key);
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if (ret < 0)
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low = mid + 1;
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else if (ret > 0)
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high = mid;
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else {
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*slot = mid;
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return 0;
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}
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}
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*slot = low;
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return 1;
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}
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/*
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* simple bin_search frontend that does the right thing for
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* leaves vs nodes
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*/
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int bin_search(struct btrfs_node *c, struct btrfs_key *key, int *slot)
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{
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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,
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sizeof(struct btrfs_item),
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key, btrfs_header_nritems(&c->header),
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slot);
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} else {
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return generic_bin_search((void *)c->keys,
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sizeof(struct btrfs_disk_key),
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key, btrfs_header_nritems(&c->header),
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slot);
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}
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return -1;
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}
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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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{
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struct btrfs_node *node = &parent_buf->node;
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if (slot < 0)
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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_root *root, struct btrfs_path *path,
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int level)
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{
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struct btrfs_buffer *right_buf;
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struct btrfs_buffer *mid_buf;
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struct btrfs_buffer *left_buf;
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struct btrfs_buffer *parent_buf = NULL;
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struct btrfs_node *right = NULL;
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struct btrfs_node *mid;
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struct btrfs_node *left = NULL;
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struct btrfs_node *parent = NULL;
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int ret = 0;
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int wret;
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int pslot;
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int orig_slot = path->slots[level];
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u64 orig_ptr;
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if (level == 0)
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return 0;
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mid_buf = path->nodes[level];
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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];
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pslot = path->slots[level + 1];
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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;
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/* promote the child to a root */
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child = read_node_slot(root, mid_buf, 0);
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BUG_ON(!child);
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root->node = child;
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path->nodes[level] = NULL;
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/* 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(root, mid_buf);
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return btrfs_free_extent(root, blocknr, 1);
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}
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parent = &parent_buf->node;
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if (btrfs_header_nritems(&mid->header) > NODEPTRS_PER_BLOCK / 4)
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return 0;
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left_buf = read_node_slot(root, parent_buf, pslot - 1);
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right_buf = read_node_slot(root, parent_buf, pslot + 1);
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/* first, try to make some room in the middle buffer */
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if (left_buf) {
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btrfs_cow_block(root, left_buf, parent_buf,
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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(root, left_buf, mid_buf);
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if (wret < 0)
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ret = wret;
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}
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/*
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* then try to empty the right most buffer into the middle
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*/
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if (right_buf) {
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btrfs_cow_block(root, right_buf, parent_buf,
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pslot + 1, &right_buf);
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right = &right_buf->node;
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wret = push_node_left(root, mid_buf, right_buf);
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if (wret < 0)
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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(root, right_buf);
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right_buf = NULL;
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right = NULL;
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wret = del_ptr(root, path, level + 1, pslot + 1);
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if (wret)
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ret = wret;
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wret = btrfs_free_extent(root, blocknr, 1);
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if (wret)
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ret = wret;
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} else {
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memcpy(parent->keys + pslot + 1, right->keys,
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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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}
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if (btrfs_header_nritems(&mid->header) == 1) {
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/*
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* we're not allowed to leave a node with one item in the
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* tree during a delete. A deletion from lower in the tree
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* could try to delete the only pointer in this node.
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* So, pull some keys from the left.
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* There has to be a left pointer at this point because
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* otherwise we would have pulled some pointers from the
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* right
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*/
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BUG_ON(!left_buf);
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wret = balance_node_right(root, mid_buf, left_buf);
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if (wret < 0)
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ret = wret;
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BUG_ON(wret == 1);
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}
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if (btrfs_header_nritems(&mid->header) == 0) {
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/* 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(root, mid_buf);
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mid_buf = NULL;
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mid = NULL;
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wret = del_ptr(root, path, level + 1, pslot);
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if (wret)
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ret = wret;
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wret = btrfs_free_extent(root, blocknr, 1);
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if (wret)
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ret = wret;
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} else {
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/* update the parent key to reflect our changes */
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memcpy(parent->keys + pslot, mid->keys,
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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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/* 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
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path->nodes[level] = left_buf;
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path->slots[level + 1] -= 1;
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path->slots[level] = orig_slot;
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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;
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}
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}
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/* double check we haven't messed things up */
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check_block(path, level);
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if (orig_ptr != btrfs_node_blockptr(&path->nodes[level]->node,
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path->slots[level]))
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BUG();
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if (right_buf)
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btrfs_block_release(root, right_buf);
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if (left_buf)
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btrfs_block_release(root, left_buf);
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return ret;
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}
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|
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/*
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* look for key in the tree. path is filled in with nodes along the way
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* if key is found, we return zero and you can find the item in the leaf
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* level of the path (level 0)
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*
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* If the key isn't found, the path points to the slot where it should
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* be inserted, and 1 is returned. If there are other errors during the
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* search a negative error number is returned.
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*
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* if ins_len > 0, nodes and leaves will be split as we walk down the
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* tree. if ins_len < 0, nodes will be merged as we walk down the tree (if
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* possible)
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*/
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int btrfs_search_slot(struct btrfs_root *root, struct btrfs_key *key,
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struct btrfs_path *p, int ins_len, int cow)
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{
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struct btrfs_buffer *b;
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struct btrfs_buffer *cow_buf;
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struct btrfs_node *c;
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int slot;
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int ret;
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int level;
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again:
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b = root->node;
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b->count++;
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while (b) {
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level = btrfs_header_level(&b->node.header);
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if (cow) {
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int wret;
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wret = btrfs_cow_block(root, b, p->nodes[level + 1],
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p->slots[level + 1], &cow_buf);
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b = cow_buf;
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}
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BUG_ON(!cow && ins_len);
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c = &b->node;
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p->nodes[level] = b;
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ret = check_block(p, level);
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if (ret)
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return -1;
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ret = bin_search(c, key, &slot);
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if (!btrfs_is_leaf(c)) {
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if (ret && slot > 0)
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slot -= 1;
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p->slots[level] = slot;
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if (ins_len > 0 && btrfs_header_nritems(&c->header) ==
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NODEPTRS_PER_BLOCK) {
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int sret = split_node(root, p, level);
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BUG_ON(sret > 0);
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if (sret)
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return sret;
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b = p->nodes[level];
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c = &b->node;
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slot = p->slots[level];
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} else if (ins_len < 0) {
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int sret = balance_level(root, p, level);
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if (sret)
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return sret;
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b = p->nodes[level];
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if (!b)
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goto again;
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c = &b->node;
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slot = p->slots[level];
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BUG_ON(btrfs_header_nritems(&c->header) == 1);
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}
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b = read_tree_block(root, btrfs_node_blockptr(c, slot));
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} else {
|
|
struct btrfs_leaf *l = (struct btrfs_leaf *)c;
|
|
p->slots[level] = slot;
|
|
if (ins_len > 0 && btrfs_leaf_free_space(l) <
|
|
sizeof(struct btrfs_item) + ins_len) {
|
|
int sret = split_leaf(root, p, ins_len);
|
|
BUG_ON(sret > 0);
|
|
if (sret)
|
|
return sret;
|
|
}
|
|
BUG_ON(root->node->count == 1);
|
|
return ret;
|
|
}
|
|
}
|
|
BUG_ON(root->node->count == 1);
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* 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
|
|
*
|
|
* If this fails to write a tree block, it returns -1, but continues
|
|
* fixing up the blocks in ram so the tree is consistent.
|
|
*/
|
|
static int fixup_low_keys(struct btrfs_root *root,
|
|
struct btrfs_path *path, struct btrfs_disk_key *key,
|
|
int level)
|
|
{
|
|
int i;
|
|
int ret = 0;
|
|
for (i = level; i < BTRFS_MAX_LEVEL; i++) {
|
|
struct btrfs_node *t;
|
|
int tslot = path->slots[i];
|
|
if (!path->nodes[i])
|
|
break;
|
|
t = &path->nodes[i]->node;
|
|
memcpy(t->keys + tslot, key, sizeof(*key));
|
|
BUG_ON(list_empty(&path->nodes[i]->dirty));
|
|
if (tslot != 0)
|
|
break;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* try to push data from one node into the next node left in the
|
|
* tree.
|
|
*
|
|
* 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.
|
|
*/
|
|
static int push_node_left(struct btrfs_root *root, struct btrfs_buffer *dst_buf,
|
|
struct btrfs_buffer *src_buf)
|
|
{
|
|
struct btrfs_node *src = &src_buf->node;
|
|
struct btrfs_node *dst = &dst_buf->node;
|
|
int push_items = 0;
|
|
int src_nritems;
|
|
int dst_nritems;
|
|
int ret = 0;
|
|
|
|
src_nritems = btrfs_header_nritems(&src->header);
|
|
dst_nritems = btrfs_header_nritems(&dst->header);
|
|
push_items = NODEPTRS_PER_BLOCK - dst_nritems;
|
|
if (push_items <= 0) {
|
|
return 1;
|
|
}
|
|
|
|
if (src_nritems < push_items)
|
|
push_items = src_nritems;
|
|
|
|
memcpy(dst->keys + dst_nritems, src->keys,
|
|
push_items * sizeof(struct btrfs_disk_key));
|
|
memcpy(dst->blockptrs + dst_nritems, src->blockptrs,
|
|
push_items * sizeof(u64));
|
|
if (push_items < src_nritems) {
|
|
memmove(src->keys, src->keys + push_items,
|
|
(src_nritems - push_items) *
|
|
sizeof(struct btrfs_disk_key));
|
|
memmove(src->blockptrs, src->blockptrs + push_items,
|
|
(src_nritems - push_items) * sizeof(u64));
|
|
}
|
|
btrfs_set_header_nritems(&src->header, src_nritems - push_items);
|
|
btrfs_set_header_nritems(&dst->header, dst_nritems + push_items);
|
|
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
|
|
*/
|
|
static int balance_node_right(struct btrfs_root *root,
|
|
struct btrfs_buffer *dst_buf,
|
|
struct btrfs_buffer *src_buf)
|
|
{
|
|
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;
|
|
|
|
src_nritems = btrfs_header_nritems(&src->header);
|
|
dst_nritems = btrfs_header_nritems(&dst->header);
|
|
push_items = NODEPTRS_PER_BLOCK - 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;
|
|
|
|
memmove(dst->keys + push_items, dst->keys,
|
|
dst_nritems * sizeof(struct btrfs_disk_key));
|
|
memmove(dst->blockptrs + push_items, dst->blockptrs,
|
|
dst_nritems * sizeof(u64));
|
|
memcpy(dst->keys, src->keys + src_nritems - push_items,
|
|
push_items * sizeof(struct btrfs_disk_key));
|
|
memcpy(dst->blockptrs, src->blockptrs + src_nritems - push_items,
|
|
push_items * sizeof(u64));
|
|
|
|
btrfs_set_header_nritems(&src->header, src_nritems - push_items);
|
|
btrfs_set_header_nritems(&dst->header, dst_nritems + push_items);
|
|
|
|
BUG_ON(list_empty(&src_buf->dirty));
|
|
BUG_ON(list_empty(&dst_buf->dirty));
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* 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
|
|
*
|
|
* returns zero on success or < 0 on failure.
|
|
*/
|
|
static int insert_new_root(struct btrfs_root *root,
|
|
struct btrfs_path *path, int level)
|
|
{
|
|
struct btrfs_buffer *t;
|
|
struct btrfs_node *lower;
|
|
struct btrfs_node *c;
|
|
struct btrfs_disk_key *lower_key;
|
|
|
|
BUG_ON(path->nodes[level]);
|
|
BUG_ON(path->nodes[level-1] != root->node);
|
|
|
|
t = btrfs_alloc_free_block(root);
|
|
c = &t->node;
|
|
memset(c, 0, sizeof(c));
|
|
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_parentid(&c->header,
|
|
btrfs_header_parentid(&root->node->node.header));
|
|
lower = &path->nodes[level-1]->node;
|
|
if (btrfs_is_leaf(lower))
|
|
lower_key = &((struct btrfs_leaf *)lower)->items[0].key;
|
|
else
|
|
lower_key = lower->keys;
|
|
memcpy(c->keys, lower_key, sizeof(struct btrfs_disk_key));
|
|
btrfs_set_node_blockptr(c, 0, path->nodes[level - 1]->blocknr);
|
|
/* the super has an extra ref to root->node */
|
|
btrfs_block_release(root, root->node);
|
|
root->node = t;
|
|
t->count++;
|
|
path->nodes[level] = t;
|
|
path->slots[level] = 0;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* worker function to insert a single pointer in a node.
|
|
* the node should have enough room for the pointer already
|
|
*
|
|
* slot and level indicate where you want the key to go, and
|
|
* blocknr is the block the key points to.
|
|
*
|
|
* returns zero on success and < 0 on any error
|
|
*/
|
|
static int insert_ptr(struct btrfs_root *root,
|
|
struct btrfs_path *path, struct btrfs_disk_key *key,
|
|
u64 blocknr, int slot, int level)
|
|
{
|
|
struct btrfs_node *lower;
|
|
int nritems;
|
|
|
|
BUG_ON(!path->nodes[level]);
|
|
lower = &path->nodes[level]->node;
|
|
nritems = btrfs_header_nritems(&lower->header);
|
|
if (slot > nritems)
|
|
BUG();
|
|
if (nritems == NODEPTRS_PER_BLOCK)
|
|
BUG();
|
|
if (slot != nritems) {
|
|
memmove(lower->keys + slot + 1, lower->keys + slot,
|
|
(nritems - slot) * sizeof(struct btrfs_disk_key));
|
|
memmove(lower->blockptrs + slot + 1, lower->blockptrs + slot,
|
|
(nritems - slot) * sizeof(u64));
|
|
}
|
|
memcpy(lower->keys + slot, key, sizeof(struct btrfs_disk_key));
|
|
btrfs_set_node_blockptr(lower, slot, blocknr);
|
|
btrfs_set_header_nritems(&lower->header, nritems + 1);
|
|
if (lower->keys[1].objectid == 0)
|
|
BUG();
|
|
BUG_ON(list_empty(&path->nodes[level]->dirty));
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* 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.
|
|
*
|
|
* returns 0 on success and < 0 on failure
|
|
*/
|
|
static int split_node(struct btrfs_root *root, struct btrfs_path *path,
|
|
int level)
|
|
{
|
|
struct btrfs_buffer *t;
|
|
struct btrfs_node *c;
|
|
struct btrfs_buffer *split_buffer;
|
|
struct btrfs_node *split;
|
|
int mid;
|
|
int ret;
|
|
int wret;
|
|
u32 c_nritems;
|
|
|
|
t = path->nodes[level];
|
|
c = &t->node;
|
|
if (t == root->node) {
|
|
/* trying to split the root, lets make a new one */
|
|
ret = insert_new_root(root, path, level + 1);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
c_nritems = btrfs_header_nritems(&c->header);
|
|
split_buffer = btrfs_alloc_free_block(root);
|
|
split = &split_buffer->node;
|
|
btrfs_set_header_flags(&split->header, btrfs_header_flags(&c->header));
|
|
btrfs_set_header_blocknr(&split->header, split_buffer->blocknr);
|
|
btrfs_set_header_parentid(&split->header,
|
|
btrfs_header_parentid(&root->node->node.header));
|
|
mid = (c_nritems + 1) / 2;
|
|
memcpy(split->keys, c->keys + mid,
|
|
(c_nritems - mid) * sizeof(struct btrfs_disk_key));
|
|
memcpy(split->blockptrs, c->blockptrs + mid,
|
|
(c_nritems - mid) * sizeof(u64));
|
|
btrfs_set_header_nritems(&split->header, c_nritems - mid);
|
|
btrfs_set_header_nritems(&c->header, mid);
|
|
ret = 0;
|
|
|
|
BUG_ON(list_empty(&t->dirty));
|
|
wret = insert_ptr(root, path, split->keys, split_buffer->blocknr,
|
|
path->slots[level + 1] + 1, level + 1);
|
|
if (wret)
|
|
ret = wret;
|
|
|
|
if (path->slots[level] >= mid) {
|
|
path->slots[level] -= mid;
|
|
btrfs_block_release(root, t);
|
|
path->nodes[level] = split_buffer;
|
|
path->slots[level + 1] += 1;
|
|
} else {
|
|
btrfs_block_release(root, split_buffer);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* 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 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;
|
|
}
|
|
|
|
/*
|
|
* 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
|
|
*
|
|
* 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.
|
|
*/
|
|
static int push_leaf_right(struct btrfs_root *root, struct btrfs_path *path,
|
|
int data_size)
|
|
{
|
|
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;
|
|
int slot;
|
|
int i;
|
|
int free_space;
|
|
int push_space = 0;
|
|
int push_items = 0;
|
|
struct btrfs_item *item;
|
|
u32 left_nritems;
|
|
u32 right_nritems;
|
|
|
|
slot = path->slots[1];
|
|
if (!path->nodes[1]) {
|
|
return 1;
|
|
}
|
|
upper = path->nodes[1];
|
|
if (slot >= btrfs_header_nritems(&upper->node.header) - 1) {
|
|
return 1;
|
|
}
|
|
right_buf = read_tree_block(root, btrfs_node_blockptr(&upper->node,
|
|
slot + 1));
|
|
right = &right_buf->leaf;
|
|
free_space = btrfs_leaf_free_space(right);
|
|
if (free_space < data_size + sizeof(struct btrfs_item)) {
|
|
btrfs_block_release(root, right_buf);
|
|
return 1;
|
|
}
|
|
/* cow and double check */
|
|
btrfs_cow_block(root, right_buf, upper, slot + 1, &right_buf);
|
|
right = &right_buf->leaf;
|
|
free_space = btrfs_leaf_free_space(right);
|
|
if (free_space < data_size + sizeof(struct btrfs_item)) {
|
|
btrfs_block_release(root, right_buf);
|
|
return 1;
|
|
}
|
|
|
|
left_nritems = btrfs_header_nritems(&left->header);
|
|
for (i = left_nritems - 1; i >= 0; i--) {
|
|
item = left->items + i;
|
|
if (path->slots[0] == i)
|
|
push_space += data_size + sizeof(*item);
|
|
if (btrfs_item_size(item) + sizeof(*item) + push_space >
|
|
free_space)
|
|
break;
|
|
push_items++;
|
|
push_space += btrfs_item_size(item) + sizeof(*item);
|
|
}
|
|
if (push_items == 0) {
|
|
btrfs_block_release(root, right_buf);
|
|
return 1;
|
|
}
|
|
right_nritems = btrfs_header_nritems(&right->header);
|
|
/* push left to right */
|
|
push_space = btrfs_item_end(left->items + left_nritems - push_items);
|
|
push_space -= leaf_data_end(left);
|
|
/* make room in the right data area */
|
|
memmove(right->data + leaf_data_end(right) - push_space,
|
|
right->data + leaf_data_end(right),
|
|
LEAF_DATA_SIZE - leaf_data_end(right));
|
|
/* copy from the left data area */
|
|
memcpy(right->data + LEAF_DATA_SIZE - push_space,
|
|
left->data + leaf_data_end(left),
|
|
push_space);
|
|
memmove(right->items + push_items, right->items,
|
|
right_nritems * sizeof(struct btrfs_item));
|
|
/* copy the items from left to right */
|
|
memcpy(right->items, left->items + left_nritems - push_items,
|
|
push_items * sizeof(struct btrfs_item));
|
|
|
|
/* update the item pointers */
|
|
right_nritems += push_items;
|
|
btrfs_set_header_nritems(&right->header, right_nritems);
|
|
push_space = LEAF_DATA_SIZE;
|
|
for (i = 0; i < right_nritems; i++) {
|
|
btrfs_set_item_offset(right->items + i, push_space -
|
|
btrfs_item_size(right->items + i));
|
|
push_space = btrfs_item_offset(right->items + i);
|
|
}
|
|
left_nritems -= push_items;
|
|
btrfs_set_header_nritems(&left->header, left_nritems);
|
|
|
|
BUG_ON(list_empty(&left_buf->dirty));
|
|
BUG_ON(list_empty(&right_buf->dirty));
|
|
memcpy(upper->node.keys + slot + 1,
|
|
&right->items[0].key, sizeof(struct btrfs_disk_key));
|
|
BUG_ON(list_empty(&upper->dirty));
|
|
|
|
/* then fixup the leaf pointer in the path */
|
|
if (path->slots[0] >= left_nritems) {
|
|
path->slots[0] -= left_nritems;
|
|
btrfs_block_release(root, path->nodes[0]);
|
|
path->nodes[0] = right_buf;
|
|
path->slots[1] += 1;
|
|
} else {
|
|
btrfs_block_release(root, right_buf);
|
|
}
|
|
return 0;
|
|
}
|
|
/*
|
|
* 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
|
|
*/
|
|
static int push_leaf_left(struct btrfs_root *root, struct btrfs_path *path,
|
|
int data_size)
|
|
{
|
|
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;
|
|
struct btrfs_item *item;
|
|
u32 old_left_nritems;
|
|
int ret = 0;
|
|
int wret;
|
|
|
|
slot = path->slots[1];
|
|
if (slot == 0) {
|
|
return 1;
|
|
}
|
|
if (!path->nodes[1]) {
|
|
return 1;
|
|
}
|
|
t = read_tree_block(root, btrfs_node_blockptr(&path->nodes[1]->node,
|
|
slot - 1));
|
|
left = &t->leaf;
|
|
free_space = btrfs_leaf_free_space(left);
|
|
if (free_space < data_size + sizeof(struct btrfs_item)) {
|
|
btrfs_block_release(root, t);
|
|
return 1;
|
|
}
|
|
|
|
/* cow and double check */
|
|
btrfs_cow_block(root, t, path->nodes[1], slot - 1, &t);
|
|
left = &t->leaf;
|
|
free_space = btrfs_leaf_free_space(left);
|
|
if (free_space < data_size + sizeof(struct btrfs_item)) {
|
|
btrfs_block_release(root, t);
|
|
return 1;
|
|
}
|
|
|
|
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);
|
|
if (btrfs_item_size(item) + sizeof(*item) + push_space >
|
|
free_space)
|
|
break;
|
|
push_items++;
|
|
push_space += btrfs_item_size(item) + sizeof(*item);
|
|
}
|
|
if (push_items == 0) {
|
|
btrfs_block_release(root, t);
|
|
return 1;
|
|
}
|
|
/* push data from right to left */
|
|
memcpy(left->items + btrfs_header_nritems(&left->header),
|
|
right->items, push_items * sizeof(struct btrfs_item));
|
|
push_space = LEAF_DATA_SIZE -
|
|
btrfs_item_offset(right->items + push_items -1);
|
|
memcpy(left->data + leaf_data_end(left) - push_space,
|
|
right->data + btrfs_item_offset(right->items + push_items - 1),
|
|
push_space);
|
|
old_left_nritems = btrfs_header_nritems(&left->header);
|
|
BUG_ON(old_left_nritems < 0);
|
|
|
|
for (i = old_left_nritems; i < old_left_nritems + push_items; i++) {
|
|
u16 ioff = btrfs_item_offset(left->items + i);
|
|
btrfs_set_item_offset(left->items + i, ioff - (LEAF_DATA_SIZE -
|
|
btrfs_item_offset(left->items +
|
|
old_left_nritems - 1)));
|
|
}
|
|
btrfs_set_header_nritems(&left->header, old_left_nritems + push_items);
|
|
|
|
/* fixup right node */
|
|
push_space = btrfs_item_offset(right->items + push_items - 1) -
|
|
leaf_data_end(right);
|
|
memmove(right->data + LEAF_DATA_SIZE - push_space, right->data +
|
|
leaf_data_end(right), push_space);
|
|
memmove(right->items, right->items + push_items,
|
|
(btrfs_header_nritems(&right->header) - push_items) *
|
|
sizeof(struct btrfs_item));
|
|
btrfs_set_header_nritems(&right->header,
|
|
btrfs_header_nritems(&right->header) -
|
|
push_items);
|
|
push_space = LEAF_DATA_SIZE;
|
|
|
|
for (i = 0; i < btrfs_header_nritems(&right->header); i++) {
|
|
btrfs_set_item_offset(right->items + i, push_space -
|
|
btrfs_item_size(right->items + i));
|
|
push_space = btrfs_item_offset(right->items + i);
|
|
}
|
|
|
|
BUG_ON(list_empty(&t->dirty));
|
|
BUG_ON(list_empty(&right_buf->dirty));
|
|
|
|
wret = fixup_low_keys(root, path, &right->items[0].key, 1);
|
|
if (wret)
|
|
ret = wret;
|
|
|
|
/* then fixup the leaf pointer in the path */
|
|
if (path->slots[0] < push_items) {
|
|
path->slots[0] += old_left_nritems;
|
|
btrfs_block_release(root, path->nodes[0]);
|
|
path->nodes[0] = t;
|
|
path->slots[1] -= 1;
|
|
} else {
|
|
btrfs_block_release(root, t);
|
|
path->slots[0] -= push_items;
|
|
}
|
|
BUG_ON(path->slots[0] < 0);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* split the path's leaf in two, making sure there is at least data_size
|
|
* available for the resulting leaf level of the path.
|
|
*
|
|
* returns 0 if all went well and < 0 on failure.
|
|
*/
|
|
static int split_leaf(struct btrfs_root *root, struct btrfs_path *path,
|
|
int data_size)
|
|
{
|
|
struct btrfs_buffer *l_buf;
|
|
struct btrfs_leaf *l;
|
|
u32 nritems;
|
|
int mid;
|
|
int slot;
|
|
struct btrfs_leaf *right;
|
|
struct btrfs_buffer *right_buffer;
|
|
int space_needed = data_size + sizeof(struct btrfs_item);
|
|
int data_copy_size;
|
|
int rt_data_off;
|
|
int i;
|
|
int ret;
|
|
int wret;
|
|
|
|
l_buf = path->nodes[0];
|
|
l = &l_buf->leaf;
|
|
|
|
/* did the pushes work? */
|
|
if (btrfs_leaf_free_space(l) >= sizeof(struct btrfs_item) + data_size)
|
|
return 0;
|
|
|
|
if (!path->nodes[1]) {
|
|
ret = insert_new_root(root, path, 1);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
slot = path->slots[0];
|
|
nritems = btrfs_header_nritems(&l->header);
|
|
mid = (nritems + 1)/ 2;
|
|
right_buffer = btrfs_alloc_free_block(root);
|
|
BUG_ON(!right_buffer);
|
|
BUG_ON(mid == nritems);
|
|
right = &right_buffer->leaf;
|
|
memset(right, 0, sizeof(*right));
|
|
if (mid <= slot) {
|
|
/* FIXME, just alloc a new leaf here */
|
|
if (leaf_space_used(l, mid, nritems - mid) + space_needed >
|
|
LEAF_DATA_SIZE)
|
|
BUG();
|
|
} else {
|
|
/* FIXME, just alloc a new leaf here */
|
|
if (leaf_space_used(l, 0, mid + 1) + space_needed >
|
|
LEAF_DATA_SIZE)
|
|
BUG();
|
|
}
|
|
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_parentid(&right->header,
|
|
btrfs_header_parentid(&root->node->node.header));
|
|
data_copy_size = btrfs_item_end(l->items + mid) - leaf_data_end(l);
|
|
memcpy(right->items, l->items + mid,
|
|
(nritems - mid) * sizeof(struct btrfs_item));
|
|
memcpy(right->data + LEAF_DATA_SIZE - data_copy_size,
|
|
l->data + leaf_data_end(l), data_copy_size);
|
|
rt_data_off = LEAF_DATA_SIZE - btrfs_item_end(l->items + mid);
|
|
|
|
for (i = 0; i < btrfs_header_nritems(&right->header); i++) {
|
|
u16 ioff = btrfs_item_offset(right->items + i);
|
|
btrfs_set_item_offset(right->items + i, ioff + rt_data_off);
|
|
}
|
|
|
|
btrfs_set_header_nritems(&l->header, mid);
|
|
ret = 0;
|
|
wret = insert_ptr(root, path, &right->items[0].key,
|
|
right_buffer->blocknr, path->slots[1] + 1, 1);
|
|
if (wret)
|
|
ret = wret;
|
|
BUG_ON(list_empty(&right_buffer->dirty));
|
|
BUG_ON(list_empty(&l_buf->dirty));
|
|
BUG_ON(path->slots[0] != slot);
|
|
if (mid <= slot) {
|
|
btrfs_block_release(root, path->nodes[0]);
|
|
path->nodes[0] = right_buffer;
|
|
path->slots[0] -= mid;
|
|
path->slots[1] += 1;
|
|
} else
|
|
btrfs_block_release(root, right_buffer);
|
|
BUG_ON(path->slots[0] < 0);
|
|
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.
|
|
*/
|
|
int btrfs_insert_item(struct btrfs_root *root, struct btrfs_key *cpu_key,
|
|
void *data, int 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;
|
|
struct btrfs_path path;
|
|
struct btrfs_disk_key disk_key;
|
|
|
|
btrfs_cpu_key_to_disk(&disk_key, cpu_key);
|
|
|
|
/* create a root if there isn't one */
|
|
if (!root->node)
|
|
BUG();
|
|
btrfs_init_path(&path);
|
|
ret = btrfs_search_slot(root, cpu_key, &path, data_size, 1);
|
|
if (ret == 0) {
|
|
btrfs_release_path(root, &path);
|
|
return -EEXIST;
|
|
}
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
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(leaf);
|
|
|
|
if (btrfs_leaf_free_space(leaf) <
|
|
sizeof(struct btrfs_item) + data_size)
|
|
BUG();
|
|
|
|
slot = path.slots[0];
|
|
BUG_ON(slot < 0);
|
|
if (slot != nritems) {
|
|
int i;
|
|
unsigned int old_data = btrfs_item_end(leaf->items + slot);
|
|
|
|
/*
|
|
* item0..itemN ... dataN.offset..dataN.size .. data0.size
|
|
*/
|
|
/* first correct the data pointers */
|
|
for (i = slot; i < nritems; i++) {
|
|
u16 ioff = btrfs_item_offset(leaf->items + i);
|
|
btrfs_set_item_offset(leaf->items + i,
|
|
ioff - data_size);
|
|
}
|
|
|
|
/* shift the items */
|
|
memmove(leaf->items + slot + 1, leaf->items + slot,
|
|
(nritems - slot) * sizeof(struct btrfs_item));
|
|
|
|
/* shift the data */
|
|
memmove(leaf->data + data_end - data_size, leaf->data +
|
|
data_end, old_data - data_end);
|
|
data_end = old_data;
|
|
}
|
|
/* copy the new data in */
|
|
memcpy(&leaf->items[slot].key, &disk_key,
|
|
sizeof(struct btrfs_disk_key));
|
|
btrfs_set_item_offset(leaf->items + slot, data_end - data_size);
|
|
btrfs_set_item_size(leaf->items + slot, data_size);
|
|
memcpy(leaf->data + data_end - data_size, data, data_size);
|
|
btrfs_set_header_nritems(&leaf->header, nritems + 1);
|
|
|
|
ret = 0;
|
|
if (slot == 0)
|
|
ret = fixup_low_keys(root, &path, &disk_key, 1);
|
|
|
|
BUG_ON(list_empty(&leaf_buf->dirty));
|
|
if (btrfs_leaf_free_space(leaf) < 0)
|
|
BUG();
|
|
check_leaf(&path, 0);
|
|
out:
|
|
btrfs_release_path(root, &path);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* delete the pointer from a given node.
|
|
*
|
|
* 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.
|
|
*/
|
|
static int del_ptr(struct btrfs_root *root, struct btrfs_path *path, int level,
|
|
int slot)
|
|
{
|
|
struct btrfs_node *node;
|
|
struct btrfs_buffer *parent = path->nodes[level];
|
|
u32 nritems;
|
|
int ret = 0;
|
|
int wret;
|
|
|
|
node = &parent->node;
|
|
nritems = btrfs_header_nritems(&node->header);
|
|
if (slot != nritems -1) {
|
|
memmove(node->keys + slot, node->keys + slot + 1,
|
|
sizeof(struct btrfs_disk_key) * (nritems - slot - 1));
|
|
memmove(node->blockptrs + slot,
|
|
node->blockptrs + slot + 1,
|
|
sizeof(u64) * (nritems - slot - 1));
|
|
}
|
|
nritems--;
|
|
btrfs_set_header_nritems(&node->header, nritems);
|
|
if (nritems == 0 && parent == root->node) {
|
|
BUG_ON(btrfs_header_level(&root->node->node.header) != 1);
|
|
/* just turn the root into a leaf and break */
|
|
btrfs_set_header_level(&root->node->node.header, 0);
|
|
} else if (slot == 0) {
|
|
wret = fixup_low_keys(root, path, node->keys, level + 1);
|
|
if (wret)
|
|
ret = wret;
|
|
}
|
|
BUG_ON(list_empty(&parent->dirty));
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* delete the item at the leaf level in path. If that empties
|
|
* the leaf, remove it from the tree
|
|
*/
|
|
int btrfs_del_item(struct btrfs_root *root, struct btrfs_path *path)
|
|
{
|
|
int slot;
|
|
struct btrfs_leaf *leaf;
|
|
struct btrfs_buffer *leaf_buf;
|
|
int doff;
|
|
int dsize;
|
|
int ret = 0;
|
|
int wret;
|
|
u32 nritems;
|
|
|
|
leaf_buf = path->nodes[0];
|
|
leaf = &leaf_buf->leaf;
|
|
slot = path->slots[0];
|
|
doff = btrfs_item_offset(leaf->items + slot);
|
|
dsize = btrfs_item_size(leaf->items + slot);
|
|
nritems = btrfs_header_nritems(&leaf->header);
|
|
|
|
if (slot != nritems - 1) {
|
|
int i;
|
|
int data_end = leaf_data_end(leaf);
|
|
memmove(leaf->data + data_end + dsize,
|
|
leaf->data + data_end,
|
|
doff - data_end);
|
|
for (i = slot + 1; i < nritems; i++) {
|
|
u16 ioff = btrfs_item_offset(leaf->items + i);
|
|
btrfs_set_item_offset(leaf->items + i, ioff + dsize);
|
|
}
|
|
memmove(leaf->items + slot, leaf->items + slot + 1,
|
|
sizeof(struct btrfs_item) *
|
|
(nritems - slot - 1));
|
|
}
|
|
btrfs_set_header_nritems(&leaf->header, nritems - 1);
|
|
nritems--;
|
|
/* delete the leaf if we've emptied it */
|
|
if (nritems == 0) {
|
|
if (leaf_buf == root->node) {
|
|
btrfs_set_header_level(&leaf->header, 0);
|
|
BUG_ON(list_empty(&leaf_buf->dirty));
|
|
} else {
|
|
clean_tree_block(root, leaf_buf);
|
|
wret = del_ptr(root, path, 1, path->slots[1]);
|
|
if (wret)
|
|
ret = wret;
|
|
wret = btrfs_free_extent(root, leaf_buf->blocknr, 1);
|
|
if (wret)
|
|
ret = wret;
|
|
}
|
|
} else {
|
|
int used = leaf_space_used(leaf, 0, nritems);
|
|
if (slot == 0) {
|
|
wret = fixup_low_keys(root, path,
|
|
&leaf->items[0].key, 1);
|
|
if (wret)
|
|
ret = wret;
|
|
}
|
|
BUG_ON(list_empty(&leaf_buf->dirty));
|
|
|
|
/* delete the leaf if it is mostly empty */
|
|
if (used < LEAF_DATA_SIZE / 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];
|
|
leaf_buf->count++;
|
|
wret = push_leaf_left(root, path, 1);
|
|
if (wret < 0)
|
|
ret = wret;
|
|
if (path->nodes[0] == leaf_buf &&
|
|
btrfs_header_nritems(&leaf->header)) {
|
|
wret = push_leaf_right(root, path, 1);
|
|
if (wret < 0)
|
|
ret = wret;
|
|
}
|
|
if (btrfs_header_nritems(&leaf->header) == 0) {
|
|
u64 blocknr = leaf_buf->blocknr;
|
|
clean_tree_block(root, leaf_buf);
|
|
wret = del_ptr(root, path, 1, slot);
|
|
if (wret)
|
|
ret = wret;
|
|
btrfs_block_release(root, leaf_buf);
|
|
wret = btrfs_free_extent(root, blocknr, 1);
|
|
if (wret)
|
|
ret = wret;
|
|
} else {
|
|
btrfs_block_release(root, leaf_buf);
|
|
}
|
|
}
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* walk up the tree as far as required to find the next leaf.
|
|
* returns 0 if it found something or 1 if there are no greater leaves.
|
|
* returns < 0 on io errors.
|
|
*/
|
|
int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path)
|
|
{
|
|
int slot;
|
|
int level = 1;
|
|
u64 blocknr;
|
|
struct btrfs_buffer *c;
|
|
struct btrfs_buffer *next = NULL;
|
|
|
|
while(level < BTRFS_MAX_LEVEL) {
|
|
if (!path->nodes[level])
|
|
return 1;
|
|
slot = path->slots[level] + 1;
|
|
c = path->nodes[level];
|
|
if (slot >= btrfs_header_nritems(&c->node.header)) {
|
|
level++;
|
|
continue;
|
|
}
|
|
blocknr = btrfs_node_blockptr(&c->node, slot);
|
|
if (next)
|
|
btrfs_block_release(root, next);
|
|
next = read_tree_block(root, blocknr);
|
|
break;
|
|
}
|
|
path->slots[level] = slot;
|
|
while(1) {
|
|
level--;
|
|
c = path->nodes[level];
|
|
btrfs_block_release(root, c);
|
|
path->nodes[level] = next;
|
|
path->slots[level] = 0;
|
|
if (!level)
|
|
break;
|
|
next = read_tree_block(root,
|
|
btrfs_node_blockptr(&next->node, 0));
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
|