forked from luck/tmp_suning_uos_patched
cc0c553847
When making room for a new item, it is ok to create an empty leaf, but when making room to extend an item, split_leaf needs to make sure it keeps the item we're extending in the path and make sure we don't end up with an empty leaf. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2464 lines
63 KiB
C
2464 lines
63 KiB
C
/*
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* Copyright (C) 2007 Oracle. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public
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* License v2 as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public
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* License along with this program; if not, write to the
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* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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* Boston, MA 021110-1307, USA.
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*/
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#include <linux/sched.h>
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#include "ctree.h"
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#include "disk-io.h"
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#include "transaction.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
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*root, struct btrfs_path *path, int level);
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static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
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*root, struct btrfs_key *ins_key,
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struct btrfs_path *path, int data_size, int extend);
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static int push_node_left(struct btrfs_trans_handle *trans,
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struct btrfs_root *root, struct extent_buffer *dst,
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struct extent_buffer *src);
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static int balance_node_right(struct btrfs_trans_handle *trans,
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struct btrfs_root *root,
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struct extent_buffer *dst_buf,
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struct extent_buffer *src_buf);
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static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
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struct btrfs_path *path, int level, 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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struct btrfs_path *btrfs_alloc_path(void)
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{
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struct btrfs_path *path;
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path = kmem_cache_alloc(btrfs_path_cachep, GFP_NOFS);
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if (path) {
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btrfs_init_path(path);
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path->reada = 1;
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}
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return path;
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}
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void btrfs_free_path(struct btrfs_path *p)
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{
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btrfs_release_path(NULL, p);
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kmem_cache_free(btrfs_path_cachep, 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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free_extent_buffer(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,
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struct btrfs_root *root,
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struct extent_buffer *buf,
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struct extent_buffer *parent, int parent_slot,
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struct extent_buffer **cow_ret,
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u64 search_start, u64 empty_size)
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{
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struct extent_buffer *cow;
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int ret = 0;
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int different_trans = 0;
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WARN_ON(root->ref_cows && trans->transid != root->last_trans);
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cow = btrfs_alloc_free_block(trans, root, buf->len,
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search_start, empty_size);
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if (IS_ERR(cow))
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return PTR_ERR(cow);
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copy_extent_buffer(cow, buf, 0, 0, cow->len);
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btrfs_set_header_bytenr(cow, cow->start);
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btrfs_set_header_generation(cow, trans->transid);
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btrfs_set_header_owner(cow, root->root_key.objectid);
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WARN_ON(btrfs_header_generation(buf) > trans->transid);
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if (btrfs_header_generation(buf) != trans->transid) {
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different_trans = 1;
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ret = btrfs_inc_ref(trans, root, buf);
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if (ret)
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return ret;
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} else {
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clean_tree_block(trans, root, buf);
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}
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if (buf == root->node) {
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root->node = cow;
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extent_buffer_get(cow);
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if (buf != root->commit_root) {
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btrfs_free_extent(trans, root, buf->start,
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buf->len, 1);
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}
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free_extent_buffer(buf);
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} else {
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btrfs_set_node_blockptr(parent, parent_slot,
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cow->start);
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btrfs_mark_buffer_dirty(parent);
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WARN_ON(btrfs_header_generation(parent) != trans->transid);
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btrfs_free_extent(trans, root, buf->start, buf->len, 1);
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}
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free_extent_buffer(buf);
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btrfs_mark_buffer_dirty(cow);
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*cow_ret = cow;
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return 0;
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}
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int btrfs_cow_block(struct btrfs_trans_handle *trans,
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struct btrfs_root *root, struct extent_buffer *buf,
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struct extent_buffer *parent, int parent_slot,
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struct extent_buffer **cow_ret)
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{
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u64 search_start;
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int ret;
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if (trans->transaction != root->fs_info->running_transaction) {
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printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
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root->fs_info->running_transaction->transid);
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WARN_ON(1);
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}
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if (trans->transid != root->fs_info->generation) {
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printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
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root->fs_info->generation);
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WARN_ON(1);
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}
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if (btrfs_header_generation(buf) == trans->transid) {
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*cow_ret = buf;
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return 0;
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}
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search_start = buf->start & ~((u64)BTRFS_BLOCK_GROUP_SIZE - 1);
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ret = __btrfs_cow_block(trans, root, buf, parent,
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parent_slot, cow_ret, search_start, 0);
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return ret;
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}
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static int close_blocks(u64 blocknr, u64 other, u32 blocksize)
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{
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if (blocknr < other && other - (blocknr + blocksize) < 32768)
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return 1;
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if (blocknr > other && blocknr - (other + blocksize) < 32768)
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return 1;
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return 0;
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}
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static int should_defrag_leaf(struct extent_buffer *leaf)
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{
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struct btrfs_key key;
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u32 nritems;
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if (btrfs_buffer_defrag(leaf))
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return 1;
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nritems = btrfs_header_nritems(leaf);
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if (nritems == 0)
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return 0;
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btrfs_item_key_to_cpu(leaf, &key, 0);
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if (key.type == BTRFS_DIR_ITEM_KEY)
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return 1;
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btrfs_item_key_to_cpu(leaf, &key, nritems - 1);
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if (key.type == BTRFS_DIR_ITEM_KEY)
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return 1;
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if (nritems > 4) {
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btrfs_item_key_to_cpu(leaf, &key, nritems / 2);
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if (key.type == BTRFS_DIR_ITEM_KEY)
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return 1;
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}
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return 0;
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}
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int btrfs_realloc_node(struct btrfs_trans_handle *trans,
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struct btrfs_root *root, struct extent_buffer *parent,
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int start_slot, int cache_only, u64 *last_ret,
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struct btrfs_key *progress)
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{
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struct extent_buffer *cur;
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struct extent_buffer *tmp;
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u64 blocknr;
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u64 search_start = *last_ret;
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u64 last_block = 0;
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u64 other;
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u32 parent_nritems;
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int end_slot;
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int i;
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int err = 0;
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int parent_level;
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int uptodate;
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u32 blocksize;
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if (trans->transaction != root->fs_info->running_transaction) {
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printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
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root->fs_info->running_transaction->transid);
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WARN_ON(1);
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}
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if (trans->transid != root->fs_info->generation) {
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printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
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root->fs_info->generation);
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WARN_ON(1);
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}
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parent_level = btrfs_header_level(parent);
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parent_nritems = btrfs_header_nritems(parent);
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blocksize = btrfs_level_size(root, parent_level - 1);
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end_slot = parent_nritems;
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if (parent_nritems == 1)
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return 0;
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if (root != root->fs_info->extent_root) {
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struct btrfs_key first_key;
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struct btrfs_key last_key;
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btrfs_node_key_to_cpu(parent, &first_key, 0);
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btrfs_node_key_to_cpu(parent, &last_key, parent_nritems - 1);
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if (first_key.objectid != last_key.objectid)
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return 0;
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}
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for (i = start_slot; i < end_slot; i++) {
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int close = 1;
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blocknr = btrfs_node_blockptr(parent, i);
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if (last_block == 0)
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last_block = blocknr;
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if (i > 0) {
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other = btrfs_node_blockptr(parent, i - 1);
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close = close_blocks(blocknr, other, blocksize);
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}
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if (close && i < end_slot - 1) {
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other = btrfs_node_blockptr(parent, i + 1);
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close = close_blocks(blocknr, other, blocksize);
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}
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if (close) {
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last_block = blocknr;
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continue;
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}
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cur = btrfs_find_tree_block(root, blocknr, blocksize);
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if (cur)
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uptodate = btrfs_buffer_uptodate(cur);
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else
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uptodate = 0;
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if (!cur || !uptodate ||
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(parent_level != 1 && !btrfs_buffer_defrag(cur)) ||
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(parent_level == 1 && !should_defrag_leaf(cur))) {
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if (cache_only) {
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free_extent_buffer(cur);
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continue;
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}
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if (!cur) {
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cur = read_tree_block(root, blocknr,
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blocksize);
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} else if (!uptodate) {
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btrfs_read_buffer(cur);
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}
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}
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if (search_start == 0)
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search_start = last_block;
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err = __btrfs_cow_block(trans, root, cur, parent, i,
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&tmp, search_start,
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min(16 * blocksize,
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(end_slot - i) * blocksize));
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if (err) {
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free_extent_buffer(cur);
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break;
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}
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search_start = tmp->start;
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*last_ret = search_start;
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if (parent_level == 1)
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btrfs_clear_buffer_defrag(tmp);
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free_extent_buffer(tmp);
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}
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return err;
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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_root *root,
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struct extent_buffer *leaf)
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{
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u32 nr = btrfs_header_nritems(leaf);
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if (nr == 0)
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return BTRFS_LEAF_DATA_SIZE(root);
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return btrfs_item_offset_nr(leaf, nr - 1);
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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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static 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.type > k2->type)
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return 1;
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if (k1.type < k2->type)
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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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static int check_node(struct btrfs_root *root, struct btrfs_path *path,
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int level)
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{
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struct extent_buffer *parent = NULL;
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struct extent_buffer *node = path->nodes[level];
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struct btrfs_disk_key parent_key;
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struct btrfs_disk_key node_key;
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int parent_slot;
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int slot;
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struct btrfs_key cpukey;
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u32 nritems = btrfs_header_nritems(node);
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if (path->nodes[level + 1])
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parent = path->nodes[level + 1];
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slot = path->slots[level];
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BUG_ON(nritems == 0);
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if (parent) {
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parent_slot = path->slots[level + 1];
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btrfs_node_key(parent, &parent_key, parent_slot);
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btrfs_node_key(node, &node_key, 0);
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BUG_ON(memcmp(&parent_key, &node_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_bytenr(node));
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}
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BUG_ON(nritems > BTRFS_NODEPTRS_PER_BLOCK(root));
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if (slot != 0) {
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btrfs_node_key_to_cpu(node, &cpukey, slot - 1);
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btrfs_node_key(node, &node_key, slot);
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BUG_ON(comp_keys(&node_key, &cpukey) <= 0);
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}
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if (slot < nritems - 1) {
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btrfs_node_key_to_cpu(node, &cpukey, slot + 1);
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btrfs_node_key(node, &node_key, slot);
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BUG_ON(comp_keys(&node_key, &cpukey) >= 0);
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}
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return 0;
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}
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static int check_leaf(struct btrfs_root *root, struct btrfs_path *path,
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int level)
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{
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struct extent_buffer *leaf = path->nodes[level];
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struct extent_buffer *parent = NULL;
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int parent_slot;
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struct btrfs_key cpukey;
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struct btrfs_disk_key parent_key;
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struct btrfs_disk_key leaf_key;
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int slot = path->slots[0];
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u32 nritems = btrfs_header_nritems(leaf);
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if (path->nodes[level + 1])
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parent = path->nodes[level + 1];
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if (nritems == 0)
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return 0;
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if (parent) {
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parent_slot = path->slots[level + 1];
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btrfs_node_key(parent, &parent_key, parent_slot);
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btrfs_item_key(leaf, &leaf_key, 0);
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BUG_ON(memcmp(&parent_key, &leaf_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_bytenr(leaf));
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}
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#if 0
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for (i = 0; nritems > 1 && i < nritems - 2; i++) {
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btrfs_item_key_to_cpu(leaf, &cpukey, i + 1);
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btrfs_item_key(leaf, &leaf_key, i);
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if (comp_keys(&leaf_key, &cpukey) >= 0) {
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btrfs_print_leaf(root, leaf);
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printk("slot %d offset bad key\n", i);
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BUG_ON(1);
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}
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if (btrfs_item_offset_nr(leaf, i) !=
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btrfs_item_end_nr(leaf, i + 1)) {
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btrfs_print_leaf(root, leaf);
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printk("slot %d offset bad\n", i);
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BUG_ON(1);
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}
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if (i == 0) {
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if (btrfs_item_offset_nr(leaf, i) +
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btrfs_item_size_nr(leaf, i) !=
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BTRFS_LEAF_DATA_SIZE(root)) {
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btrfs_print_leaf(root, leaf);
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printk("slot %d first offset bad\n", i);
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BUG_ON(1);
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}
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}
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}
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if (nritems > 0) {
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if (btrfs_item_size_nr(leaf, nritems - 1) > 4096) {
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btrfs_print_leaf(root, leaf);
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printk("slot %d bad size \n", nritems - 1);
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BUG_ON(1);
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}
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}
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#endif
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if (slot != 0 && slot < nritems - 1) {
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btrfs_item_key(leaf, &leaf_key, slot);
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btrfs_item_key_to_cpu(leaf, &cpukey, slot - 1);
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if (comp_keys(&leaf_key, &cpukey) <= 0) {
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btrfs_print_leaf(root, leaf);
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printk("slot %d offset bad key\n", slot);
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BUG_ON(1);
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}
|
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if (btrfs_item_offset_nr(leaf, slot - 1) !=
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btrfs_item_end_nr(leaf, slot)) {
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btrfs_print_leaf(root, leaf);
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printk("slot %d offset bad\n", slot);
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BUG_ON(1);
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}
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}
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if (slot < nritems - 1) {
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btrfs_item_key(leaf, &leaf_key, slot);
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btrfs_item_key_to_cpu(leaf, &cpukey, slot + 1);
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BUG_ON(comp_keys(&leaf_key, &cpukey) >= 0);
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if (btrfs_item_offset_nr(leaf, slot) !=
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btrfs_item_end_nr(leaf, slot + 1)) {
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btrfs_print_leaf(root, leaf);
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printk("slot %d offset bad\n", slot);
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BUG_ON(1);
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}
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}
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BUG_ON(btrfs_item_offset_nr(leaf, 0) +
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btrfs_item_size_nr(leaf, 0) != BTRFS_LEAF_DATA_SIZE(root));
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return 0;
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}
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|
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static int check_block(struct btrfs_root *root, struct btrfs_path *path,
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int level)
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{
|
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return 0;
|
|
#if 0
|
|
struct extent_buffer *buf = path->nodes[level];
|
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|
|
if (memcmp_extent_buffer(buf, root->fs_info->fsid,
|
|
(unsigned long)btrfs_header_fsid(buf),
|
|
BTRFS_FSID_SIZE)) {
|
|
printk("warning bad block %Lu\n", buf->start);
|
|
return 1;
|
|
}
|
|
#endif
|
|
if (level == 0)
|
|
return check_leaf(root, path, level);
|
|
return check_node(root, path, level);
|
|
}
|
|
|
|
/*
|
|
* search for key in the extent_buffer. The items start at offset p,
|
|
* and they are item_size apart. 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
|
|
*/
|
|
static int generic_bin_search(struct extent_buffer *eb, unsigned long p,
|
|
int item_size, struct btrfs_key *key,
|
|
int max, int *slot)
|
|
{
|
|
int low = 0;
|
|
int high = max;
|
|
int mid;
|
|
int ret;
|
|
struct btrfs_disk_key *tmp = NULL;
|
|
struct btrfs_disk_key unaligned;
|
|
unsigned long offset;
|
|
char *map_token = NULL;
|
|
char *kaddr = NULL;
|
|
unsigned long map_start = 0;
|
|
unsigned long map_len = 0;
|
|
int err;
|
|
|
|
while(low < high) {
|
|
mid = (low + high) / 2;
|
|
offset = p + mid * item_size;
|
|
|
|
if (!map_token || offset < map_start ||
|
|
(offset + sizeof(struct btrfs_disk_key)) >
|
|
map_start + map_len) {
|
|
if (map_token) {
|
|
unmap_extent_buffer(eb, map_token, KM_USER0);
|
|
map_token = NULL;
|
|
}
|
|
err = map_extent_buffer(eb, offset,
|
|
sizeof(struct btrfs_disk_key),
|
|
&map_token, &kaddr,
|
|
&map_start, &map_len, KM_USER0);
|
|
|
|
if (!err) {
|
|
tmp = (struct btrfs_disk_key *)(kaddr + offset -
|
|
map_start);
|
|
} else {
|
|
read_extent_buffer(eb, &unaligned,
|
|
offset, sizeof(unaligned));
|
|
tmp = &unaligned;
|
|
}
|
|
|
|
} else {
|
|
tmp = (struct btrfs_disk_key *)(kaddr + offset -
|
|
map_start);
|
|
}
|
|
ret = comp_keys(tmp, key);
|
|
|
|
if (ret < 0)
|
|
low = mid + 1;
|
|
else if (ret > 0)
|
|
high = mid;
|
|
else {
|
|
*slot = mid;
|
|
if (map_token)
|
|
unmap_extent_buffer(eb, map_token, KM_USER0);
|
|
return 0;
|
|
}
|
|
}
|
|
*slot = low;
|
|
if (map_token)
|
|
unmap_extent_buffer(eb, map_token, KM_USER0);
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* simple bin_search frontend that does the right thing for
|
|
* leaves vs nodes
|
|
*/
|
|
static int bin_search(struct extent_buffer *eb, struct btrfs_key *key,
|
|
int level, int *slot)
|
|
{
|
|
if (level == 0) {
|
|
return generic_bin_search(eb,
|
|
offsetof(struct btrfs_leaf, items),
|
|
sizeof(struct btrfs_item),
|
|
key, btrfs_header_nritems(eb),
|
|
slot);
|
|
} else {
|
|
return generic_bin_search(eb,
|
|
offsetof(struct btrfs_node, ptrs),
|
|
sizeof(struct btrfs_key_ptr),
|
|
key, btrfs_header_nritems(eb),
|
|
slot);
|
|
}
|
|
return -1;
|
|
}
|
|
|
|
static struct extent_buffer *read_node_slot(struct btrfs_root *root,
|
|
struct extent_buffer *parent, int slot)
|
|
{
|
|
if (slot < 0)
|
|
return NULL;
|
|
if (slot >= btrfs_header_nritems(parent))
|
|
return NULL;
|
|
return read_tree_block(root, btrfs_node_blockptr(parent, slot),
|
|
btrfs_level_size(root, btrfs_header_level(parent) - 1));
|
|
}
|
|
|
|
static int balance_level(struct btrfs_trans_handle *trans, struct btrfs_root
|
|
*root, struct btrfs_path *path, int level)
|
|
{
|
|
struct extent_buffer *right = NULL;
|
|
struct extent_buffer *mid;
|
|
struct extent_buffer *left = NULL;
|
|
struct extent_buffer *parent = NULL;
|
|
int ret = 0;
|
|
int wret;
|
|
int pslot;
|
|
int orig_slot = path->slots[level];
|
|
int err_on_enospc = 0;
|
|
u64 orig_ptr;
|
|
|
|
if (level == 0)
|
|
return 0;
|
|
|
|
mid = path->nodes[level];
|
|
orig_ptr = btrfs_node_blockptr(mid, orig_slot);
|
|
|
|
if (level < BTRFS_MAX_LEVEL - 1)
|
|
parent = path->nodes[level + 1];
|
|
pslot = path->slots[level + 1];
|
|
|
|
/*
|
|
* deal with the case where there is only one pointer in the root
|
|
* by promoting the node below to a root
|
|
*/
|
|
if (!parent) {
|
|
struct extent_buffer *child;
|
|
|
|
if (btrfs_header_nritems(mid) != 1)
|
|
return 0;
|
|
|
|
/* promote the child to a root */
|
|
child = read_node_slot(root, mid, 0);
|
|
BUG_ON(!child);
|
|
root->node = child;
|
|
path->nodes[level] = NULL;
|
|
clean_tree_block(trans, root, mid);
|
|
wait_on_tree_block_writeback(root, mid);
|
|
/* once for the path */
|
|
free_extent_buffer(mid);
|
|
ret = btrfs_free_extent(trans, root, mid->start, mid->len, 1);
|
|
/* once for the root ptr */
|
|
free_extent_buffer(mid);
|
|
return ret;
|
|
}
|
|
if (btrfs_header_nritems(mid) >
|
|
BTRFS_NODEPTRS_PER_BLOCK(root) / 4)
|
|
return 0;
|
|
|
|
if (btrfs_header_nritems(mid) < 2)
|
|
err_on_enospc = 1;
|
|
|
|
left = read_node_slot(root, parent, pslot - 1);
|
|
if (left) {
|
|
wret = btrfs_cow_block(trans, root, left,
|
|
parent, pslot - 1, &left);
|
|
if (wret) {
|
|
ret = wret;
|
|
goto enospc;
|
|
}
|
|
}
|
|
right = read_node_slot(root, parent, pslot + 1);
|
|
if (right) {
|
|
wret = btrfs_cow_block(trans, root, right,
|
|
parent, pslot + 1, &right);
|
|
if (wret) {
|
|
ret = wret;
|
|
goto enospc;
|
|
}
|
|
}
|
|
|
|
/* first, try to make some room in the middle buffer */
|
|
if (left) {
|
|
orig_slot += btrfs_header_nritems(left);
|
|
wret = push_node_left(trans, root, left, mid);
|
|
if (wret < 0)
|
|
ret = wret;
|
|
if (btrfs_header_nritems(mid) < 2)
|
|
err_on_enospc = 1;
|
|
}
|
|
|
|
/*
|
|
* then try to empty the right most buffer into the middle
|
|
*/
|
|
if (right) {
|
|
wret = push_node_left(trans, root, mid, right);
|
|
if (wret < 0 && wret != -ENOSPC)
|
|
ret = wret;
|
|
if (btrfs_header_nritems(right) == 0) {
|
|
u64 bytenr = right->start;
|
|
u32 blocksize = right->len;
|
|
|
|
clean_tree_block(trans, root, right);
|
|
wait_on_tree_block_writeback(root, right);
|
|
free_extent_buffer(right);
|
|
right = NULL;
|
|
wret = del_ptr(trans, root, path, level + 1, pslot +
|
|
1);
|
|
if (wret)
|
|
ret = wret;
|
|
wret = btrfs_free_extent(trans, root, bytenr,
|
|
blocksize, 1);
|
|
if (wret)
|
|
ret = wret;
|
|
} else {
|
|
struct btrfs_disk_key right_key;
|
|
btrfs_node_key(right, &right_key, 0);
|
|
btrfs_set_node_key(parent, &right_key, pslot + 1);
|
|
btrfs_mark_buffer_dirty(parent);
|
|
}
|
|
}
|
|
if (btrfs_header_nritems(mid) == 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);
|
|
wret = balance_node_right(trans, root, mid, left);
|
|
if (wret < 0) {
|
|
ret = wret;
|
|
goto enospc;
|
|
}
|
|
BUG_ON(wret == 1);
|
|
}
|
|
if (btrfs_header_nritems(mid) == 0) {
|
|
/* we've managed to empty the middle node, drop it */
|
|
u64 bytenr = mid->start;
|
|
u32 blocksize = mid->len;
|
|
clean_tree_block(trans, root, mid);
|
|
wait_on_tree_block_writeback(root, mid);
|
|
free_extent_buffer(mid);
|
|
mid = NULL;
|
|
wret = del_ptr(trans, root, path, level + 1, pslot);
|
|
if (wret)
|
|
ret = wret;
|
|
wret = btrfs_free_extent(trans, root, bytenr, blocksize, 1);
|
|
if (wret)
|
|
ret = wret;
|
|
} else {
|
|
/* update the parent key to reflect our changes */
|
|
struct btrfs_disk_key mid_key;
|
|
btrfs_node_key(mid, &mid_key, 0);
|
|
btrfs_set_node_key(parent, &mid_key, pslot);
|
|
btrfs_mark_buffer_dirty(parent);
|
|
}
|
|
|
|
/* update the path */
|
|
if (left) {
|
|
if (btrfs_header_nritems(left) > orig_slot) {
|
|
extent_buffer_get(left);
|
|
path->nodes[level] = left;
|
|
path->slots[level + 1] -= 1;
|
|
path->slots[level] = orig_slot;
|
|
if (mid)
|
|
free_extent_buffer(mid);
|
|
} else {
|
|
orig_slot -= btrfs_header_nritems(left);
|
|
path->slots[level] = orig_slot;
|
|
}
|
|
}
|
|
/* double check we haven't messed things up */
|
|
check_block(root, path, level);
|
|
if (orig_ptr !=
|
|
btrfs_node_blockptr(path->nodes[level], path->slots[level]))
|
|
BUG();
|
|
enospc:
|
|
if (right)
|
|
free_extent_buffer(right);
|
|
if (left)
|
|
free_extent_buffer(left);
|
|
return ret;
|
|
}
|
|
|
|
/* returns zero if the push worked, non-zero otherwise */
|
|
static int push_nodes_for_insert(struct btrfs_trans_handle *trans,
|
|
struct btrfs_root *root,
|
|
struct btrfs_path *path, int level)
|
|
{
|
|
struct extent_buffer *right = NULL;
|
|
struct extent_buffer *mid;
|
|
struct extent_buffer *left = NULL;
|
|
struct extent_buffer *parent = NULL;
|
|
int ret = 0;
|
|
int wret;
|
|
int pslot;
|
|
int orig_slot = path->slots[level];
|
|
u64 orig_ptr;
|
|
|
|
if (level == 0)
|
|
return 1;
|
|
|
|
mid = path->nodes[level];
|
|
orig_ptr = btrfs_node_blockptr(mid, orig_slot);
|
|
|
|
if (level < BTRFS_MAX_LEVEL - 1)
|
|
parent = path->nodes[level + 1];
|
|
pslot = path->slots[level + 1];
|
|
|
|
if (!parent)
|
|
return 1;
|
|
|
|
left = read_node_slot(root, parent, pslot - 1);
|
|
|
|
/* first, try to make some room in the middle buffer */
|
|
if (left) {
|
|
u32 left_nr;
|
|
left_nr = btrfs_header_nritems(left);
|
|
if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
|
|
wret = 1;
|
|
} else {
|
|
ret = btrfs_cow_block(trans, root, left, parent,
|
|
pslot - 1, &left);
|
|
if (ret)
|
|
wret = 1;
|
|
else {
|
|
wret = push_node_left(trans, root,
|
|
left, mid);
|
|
}
|
|
}
|
|
if (wret < 0)
|
|
ret = wret;
|
|
if (wret == 0) {
|
|
struct btrfs_disk_key disk_key;
|
|
orig_slot += left_nr;
|
|
btrfs_node_key(mid, &disk_key, 0);
|
|
btrfs_set_node_key(parent, &disk_key, pslot);
|
|
btrfs_mark_buffer_dirty(parent);
|
|
if (btrfs_header_nritems(left) > orig_slot) {
|
|
path->nodes[level] = left;
|
|
path->slots[level + 1] -= 1;
|
|
path->slots[level] = orig_slot;
|
|
free_extent_buffer(mid);
|
|
} else {
|
|
orig_slot -=
|
|
btrfs_header_nritems(left);
|
|
path->slots[level] = orig_slot;
|
|
free_extent_buffer(left);
|
|
}
|
|
return 0;
|
|
}
|
|
free_extent_buffer(left);
|
|
}
|
|
right= read_node_slot(root, parent, pslot + 1);
|
|
|
|
/*
|
|
* then try to empty the right most buffer into the middle
|
|
*/
|
|
if (right) {
|
|
u32 right_nr;
|
|
right_nr = btrfs_header_nritems(right);
|
|
if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
|
|
wret = 1;
|
|
} else {
|
|
ret = btrfs_cow_block(trans, root, right,
|
|
parent, pslot + 1,
|
|
&right);
|
|
if (ret)
|
|
wret = 1;
|
|
else {
|
|
wret = balance_node_right(trans, root,
|
|
right, mid);
|
|
}
|
|
}
|
|
if (wret < 0)
|
|
ret = wret;
|
|
if (wret == 0) {
|
|
struct btrfs_disk_key disk_key;
|
|
|
|
btrfs_node_key(right, &disk_key, 0);
|
|
btrfs_set_node_key(parent, &disk_key, pslot + 1);
|
|
btrfs_mark_buffer_dirty(parent);
|
|
|
|
if (btrfs_header_nritems(mid) <= orig_slot) {
|
|
path->nodes[level] = right;
|
|
path->slots[level + 1] += 1;
|
|
path->slots[level] = orig_slot -
|
|
btrfs_header_nritems(mid);
|
|
free_extent_buffer(mid);
|
|
} else {
|
|
free_extent_buffer(right);
|
|
}
|
|
return 0;
|
|
}
|
|
free_extent_buffer(right);
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* readahead one full node of leaves
|
|
*/
|
|
static void reada_for_search(struct btrfs_root *root, struct btrfs_path *path,
|
|
int level, int slot)
|
|
{
|
|
struct extent_buffer *node;
|
|
u32 nritems;
|
|
u64 search;
|
|
u64 lowest_read;
|
|
u64 highest_read;
|
|
u64 nread = 0;
|
|
int direction = path->reada;
|
|
struct extent_buffer *eb;
|
|
u32 nr;
|
|
u32 blocksize;
|
|
u32 nscan = 0;
|
|
|
|
if (level != 1)
|
|
return;
|
|
|
|
if (!path->nodes[level])
|
|
return;
|
|
|
|
node = path->nodes[level];
|
|
search = btrfs_node_blockptr(node, slot);
|
|
blocksize = btrfs_level_size(root, level - 1);
|
|
eb = btrfs_find_tree_block(root, search, blocksize);
|
|
if (eb) {
|
|
free_extent_buffer(eb);
|
|
return;
|
|
}
|
|
|
|
highest_read = search;
|
|
lowest_read = search;
|
|
|
|
nritems = btrfs_header_nritems(node);
|
|
nr = slot;
|
|
while(1) {
|
|
if (direction < 0) {
|
|
if (nr == 0)
|
|
break;
|
|
nr--;
|
|
} else if (direction > 0) {
|
|
nr++;
|
|
if (nr >= nritems)
|
|
break;
|
|
}
|
|
search = btrfs_node_blockptr(node, nr);
|
|
if ((search >= lowest_read && search <= highest_read) ||
|
|
(search < lowest_read && lowest_read - search <= 32768) ||
|
|
(search > highest_read && search - highest_read <= 32768)) {
|
|
readahead_tree_block(root, search, blocksize);
|
|
nread += blocksize;
|
|
}
|
|
nscan++;
|
|
if (path->reada < 2 && (nread > (256 * 1024) || nscan > 32))
|
|
break;
|
|
if(nread > (1024 * 1024) || nscan > 128)
|
|
break;
|
|
|
|
if (search < lowest_read)
|
|
lowest_read = search;
|
|
if (search > highest_read)
|
|
highest_read = search;
|
|
}
|
|
}
|
|
/*
|
|
* 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
|
|
* be inserted, and 1 is returned. If there are other errors during the
|
|
* search a negative error number is returned.
|
|
*
|
|
* 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)
|
|
*/
|
|
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)
|
|
{
|
|
struct extent_buffer *b;
|
|
u64 bytenr;
|
|
int slot;
|
|
int ret;
|
|
int level;
|
|
int should_reada = p->reada;
|
|
u8 lowest_level = 0;
|
|
|
|
lowest_level = p->lowest_level;
|
|
WARN_ON(lowest_level && ins_len);
|
|
WARN_ON(p->nodes[0] != NULL);
|
|
WARN_ON(!mutex_is_locked(&root->fs_info->fs_mutex));
|
|
again:
|
|
b = root->node;
|
|
extent_buffer_get(b);
|
|
while (b) {
|
|
level = btrfs_header_level(b);
|
|
if (cow) {
|
|
int wret;
|
|
wret = btrfs_cow_block(trans, root, b,
|
|
p->nodes[level + 1],
|
|
p->slots[level + 1],
|
|
&b);
|
|
if (wret) {
|
|
free_extent_buffer(b);
|
|
return wret;
|
|
}
|
|
}
|
|
BUG_ON(!cow && ins_len);
|
|
if (level != btrfs_header_level(b))
|
|
WARN_ON(1);
|
|
level = btrfs_header_level(b);
|
|
p->nodes[level] = b;
|
|
ret = check_block(root, p, level);
|
|
if (ret)
|
|
return -1;
|
|
ret = bin_search(b, key, level, &slot);
|
|
if (level != 0) {
|
|
if (ret && slot > 0)
|
|
slot -= 1;
|
|
p->slots[level] = slot;
|
|
if (ins_len > 0 && btrfs_header_nritems(b) >=
|
|
BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
|
|
int sret = split_node(trans, root, p, level);
|
|
BUG_ON(sret > 0);
|
|
if (sret)
|
|
return sret;
|
|
b = p->nodes[level];
|
|
slot = p->slots[level];
|
|
} else if (ins_len < 0) {
|
|
int sret = balance_level(trans, root, p,
|
|
level);
|
|
if (sret)
|
|
return sret;
|
|
b = p->nodes[level];
|
|
if (!b) {
|
|
btrfs_release_path(NULL, p);
|
|
goto again;
|
|
}
|
|
slot = p->slots[level];
|
|
BUG_ON(btrfs_header_nritems(b) == 1);
|
|
}
|
|
/* this is only true while dropping a snapshot */
|
|
if (level == lowest_level)
|
|
break;
|
|
bytenr = btrfs_node_blockptr(b, slot);
|
|
if (should_reada)
|
|
reada_for_search(root, p, level, slot);
|
|
b = read_tree_block(root, bytenr,
|
|
btrfs_level_size(root, level - 1));
|
|
} else {
|
|
p->slots[level] = slot;
|
|
if (ins_len > 0 && btrfs_leaf_free_space(root, b) <
|
|
sizeof(struct btrfs_item) + ins_len) {
|
|
int sret = split_leaf(trans, root, key,
|
|
p, ins_len, ret == 0);
|
|
BUG_ON(sret > 0);
|
|
if (sret)
|
|
return sret;
|
|
}
|
|
return ret;
|
|
}
|
|
}
|
|
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_trans_handle *trans,
|
|
struct btrfs_root *root, struct btrfs_path *path,
|
|
struct btrfs_disk_key *key, int level)
|
|
{
|
|
int i;
|
|
int ret = 0;
|
|
struct extent_buffer *t;
|
|
|
|
for (i = level; i < BTRFS_MAX_LEVEL; i++) {
|
|
int tslot = path->slots[i];
|
|
if (!path->nodes[i])
|
|
break;
|
|
t = path->nodes[i];
|
|
btrfs_set_node_key(t, key, tslot);
|
|
btrfs_mark_buffer_dirty(path->nodes[i]);
|
|
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_trans_handle *trans, struct btrfs_root
|
|
*root, struct extent_buffer *dst,
|
|
struct extent_buffer *src)
|
|
{
|
|
int push_items = 0;
|
|
int src_nritems;
|
|
int dst_nritems;
|
|
int ret = 0;
|
|
|
|
src_nritems = btrfs_header_nritems(src);
|
|
dst_nritems = btrfs_header_nritems(dst);
|
|
push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
|
|
|
|
if (push_items <= 0) {
|
|
return 1;
|
|
}
|
|
|
|
if (src_nritems < push_items)
|
|
push_items = src_nritems;
|
|
|
|
copy_extent_buffer(dst, src,
|
|
btrfs_node_key_ptr_offset(dst_nritems),
|
|
btrfs_node_key_ptr_offset(0),
|
|
push_items * sizeof(struct btrfs_key_ptr));
|
|
|
|
if (push_items < src_nritems) {
|
|
memmove_extent_buffer(src, btrfs_node_key_ptr_offset(0),
|
|
btrfs_node_key_ptr_offset(push_items),
|
|
(src_nritems - push_items) *
|
|
sizeof(struct btrfs_key_ptr));
|
|
}
|
|
btrfs_set_header_nritems(src, src_nritems - push_items);
|
|
btrfs_set_header_nritems(dst, dst_nritems + push_items);
|
|
btrfs_mark_buffer_dirty(src);
|
|
btrfs_mark_buffer_dirty(dst);
|
|
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_trans_handle *trans,
|
|
struct btrfs_root *root,
|
|
struct extent_buffer *dst,
|
|
struct extent_buffer *src)
|
|
{
|
|
int push_items = 0;
|
|
int max_push;
|
|
int src_nritems;
|
|
int dst_nritems;
|
|
int ret = 0;
|
|
|
|
src_nritems = btrfs_header_nritems(src);
|
|
dst_nritems = btrfs_header_nritems(dst);
|
|
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;
|
|
|
|
memmove_extent_buffer(dst, btrfs_node_key_ptr_offset(push_items),
|
|
btrfs_node_key_ptr_offset(0),
|
|
(dst_nritems) *
|
|
sizeof(struct btrfs_key_ptr));
|
|
|
|
copy_extent_buffer(dst, src,
|
|
btrfs_node_key_ptr_offset(0),
|
|
btrfs_node_key_ptr_offset(src_nritems - push_items),
|
|
push_items * sizeof(struct btrfs_key_ptr));
|
|
|
|
btrfs_set_header_nritems(src, src_nritems - push_items);
|
|
btrfs_set_header_nritems(dst, dst_nritems + push_items);
|
|
|
|
btrfs_mark_buffer_dirty(src);
|
|
btrfs_mark_buffer_dirty(dst);
|
|
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_trans_handle *trans,
|
|
struct btrfs_root *root,
|
|
struct btrfs_path *path, int level)
|
|
{
|
|
struct extent_buffer *lower;
|
|
struct extent_buffer *c;
|
|
struct btrfs_disk_key lower_key;
|
|
|
|
BUG_ON(path->nodes[level]);
|
|
BUG_ON(path->nodes[level-1] != root->node);
|
|
|
|
c = btrfs_alloc_free_block(trans, root, root->nodesize,
|
|
root->node->start, 0);
|
|
if (IS_ERR(c))
|
|
return PTR_ERR(c);
|
|
memset_extent_buffer(c, 0, 0, root->nodesize);
|
|
btrfs_set_header_nritems(c, 1);
|
|
btrfs_set_header_level(c, level);
|
|
btrfs_set_header_bytenr(c, c->start);
|
|
btrfs_set_header_generation(c, trans->transid);
|
|
btrfs_set_header_owner(c, root->root_key.objectid);
|
|
lower = path->nodes[level-1];
|
|
|
|
write_extent_buffer(c, root->fs_info->fsid,
|
|
(unsigned long)btrfs_header_fsid(c),
|
|
BTRFS_FSID_SIZE);
|
|
if (level == 1)
|
|
btrfs_item_key(lower, &lower_key, 0);
|
|
else
|
|
btrfs_node_key(lower, &lower_key, 0);
|
|
btrfs_set_node_key(c, &lower_key, 0);
|
|
btrfs_set_node_blockptr(c, 0, lower->start);
|
|
|
|
btrfs_mark_buffer_dirty(c);
|
|
|
|
/* the super has an extra ref to root->node */
|
|
free_extent_buffer(root->node);
|
|
root->node = c;
|
|
extent_buffer_get(c);
|
|
path->nodes[level] = c;
|
|
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_trans_handle *trans, struct btrfs_root
|
|
*root, struct btrfs_path *path, struct btrfs_disk_key
|
|
*key, u64 bytenr, int slot, int level)
|
|
{
|
|
struct extent_buffer *lower;
|
|
int nritems;
|
|
|
|
BUG_ON(!path->nodes[level]);
|
|
lower = path->nodes[level];
|
|
nritems = btrfs_header_nritems(lower);
|
|
if (slot > nritems)
|
|
BUG();
|
|
if (nritems == BTRFS_NODEPTRS_PER_BLOCK(root))
|
|
BUG();
|
|
if (slot != nritems) {
|
|
memmove_extent_buffer(lower,
|
|
btrfs_node_key_ptr_offset(slot + 1),
|
|
btrfs_node_key_ptr_offset(slot),
|
|
(nritems - slot) * sizeof(struct btrfs_key_ptr));
|
|
}
|
|
btrfs_set_node_key(lower, key, slot);
|
|
btrfs_set_node_blockptr(lower, slot, bytenr);
|
|
btrfs_set_header_nritems(lower, nritems + 1);
|
|
btrfs_mark_buffer_dirty(lower);
|
|
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_trans_handle *trans, struct btrfs_root
|
|
*root, struct btrfs_path *path, int level)
|
|
{
|
|
struct extent_buffer *c;
|
|
struct extent_buffer *split;
|
|
struct btrfs_disk_key disk_key;
|
|
int mid;
|
|
int ret;
|
|
int wret;
|
|
u32 c_nritems;
|
|
|
|
c = path->nodes[level];
|
|
if (c == root->node) {
|
|
/* trying to split the root, lets make a new one */
|
|
ret = insert_new_root(trans, root, path, level + 1);
|
|
if (ret)
|
|
return ret;
|
|
} else {
|
|
ret = push_nodes_for_insert(trans, root, path, level);
|
|
c = path->nodes[level];
|
|
if (!ret && btrfs_header_nritems(c) <
|
|
BTRFS_NODEPTRS_PER_BLOCK(root) - 1)
|
|
return 0;
|
|
if (ret < 0)
|
|
return ret;
|
|
}
|
|
|
|
c_nritems = btrfs_header_nritems(c);
|
|
split = btrfs_alloc_free_block(trans, root, root->nodesize,
|
|
c->start, 0);
|
|
if (IS_ERR(split))
|
|
return PTR_ERR(split);
|
|
|
|
btrfs_set_header_flags(split, btrfs_header_flags(c));
|
|
btrfs_set_header_level(split, btrfs_header_level(c));
|
|
btrfs_set_header_bytenr(split, split->start);
|
|
btrfs_set_header_generation(split, trans->transid);
|
|
btrfs_set_header_owner(split, root->root_key.objectid);
|
|
write_extent_buffer(split, root->fs_info->fsid,
|
|
(unsigned long)btrfs_header_fsid(split),
|
|
BTRFS_FSID_SIZE);
|
|
|
|
mid = (c_nritems + 1) / 2;
|
|
|
|
copy_extent_buffer(split, c,
|
|
btrfs_node_key_ptr_offset(0),
|
|
btrfs_node_key_ptr_offset(mid),
|
|
(c_nritems - mid) * sizeof(struct btrfs_key_ptr));
|
|
btrfs_set_header_nritems(split, c_nritems - mid);
|
|
btrfs_set_header_nritems(c, mid);
|
|
ret = 0;
|
|
|
|
btrfs_mark_buffer_dirty(c);
|
|
btrfs_mark_buffer_dirty(split);
|
|
|
|
btrfs_node_key(split, &disk_key, 0);
|
|
wret = insert_ptr(trans, root, path, &disk_key, split->start,
|
|
path->slots[level + 1] + 1,
|
|
level + 1);
|
|
if (wret)
|
|
ret = wret;
|
|
|
|
if (path->slots[level] >= mid) {
|
|
path->slots[level] -= mid;
|
|
free_extent_buffer(c);
|
|
path->nodes[level] = split;
|
|
path->slots[level + 1] += 1;
|
|
} else {
|
|
free_extent_buffer(split);
|
|
}
|
|
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 extent_buffer *l, int start, int nr)
|
|
{
|
|
int data_len;
|
|
int nritems = btrfs_header_nritems(l);
|
|
int end = min(nritems, start + nr) - 1;
|
|
|
|
if (!nr)
|
|
return 0;
|
|
data_len = btrfs_item_end_nr(l, start);
|
|
data_len = data_len - btrfs_item_offset_nr(l, end);
|
|
data_len += sizeof(struct btrfs_item) * nr;
|
|
WARN_ON(data_len < 0);
|
|
return data_len;
|
|
}
|
|
|
|
/*
|
|
* 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
|
|
*/
|
|
int btrfs_leaf_free_space(struct btrfs_root *root, struct extent_buffer *leaf)
|
|
{
|
|
int nritems = btrfs_header_nritems(leaf);
|
|
int ret;
|
|
ret = BTRFS_LEAF_DATA_SIZE(root) - leaf_space_used(leaf, 0, nritems);
|
|
if (ret < 0) {
|
|
printk("leaf free space ret %d, leaf data size %lu, used %d nritems %d\n",
|
|
ret, (unsigned long) BTRFS_LEAF_DATA_SIZE(root),
|
|
leaf_space_used(leaf, 0, nritems), nritems);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* 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_trans_handle *trans, struct btrfs_root
|
|
*root, struct btrfs_path *path, int data_size)
|
|
{
|
|
struct extent_buffer *left = path->nodes[0];
|
|
struct extent_buffer *right;
|
|
struct extent_buffer *upper;
|
|
struct btrfs_disk_key disk_key;
|
|
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;
|
|
u32 data_end;
|
|
u32 this_item_size;
|
|
int ret;
|
|
|
|
slot = path->slots[1];
|
|
if (!path->nodes[1]) {
|
|
return 1;
|
|
}
|
|
upper = path->nodes[1];
|
|
if (slot >= btrfs_header_nritems(upper) - 1)
|
|
return 1;
|
|
|
|
right = read_tree_block(root, btrfs_node_blockptr(upper, slot + 1),
|
|
root->leafsize);
|
|
free_space = btrfs_leaf_free_space(root, right);
|
|
if (free_space < data_size + sizeof(struct btrfs_item)) {
|
|
free_extent_buffer(right);
|
|
return 1;
|
|
}
|
|
|
|
/* cow and double check */
|
|
ret = btrfs_cow_block(trans, root, right, upper,
|
|
slot + 1, &right);
|
|
if (ret) {
|
|
free_extent_buffer(right);
|
|
return 1;
|
|
}
|
|
free_space = btrfs_leaf_free_space(root, right);
|
|
if (free_space < data_size + sizeof(struct btrfs_item)) {
|
|
free_extent_buffer(right);
|
|
return 1;
|
|
}
|
|
|
|
left_nritems = btrfs_header_nritems(left);
|
|
if (left_nritems == 0) {
|
|
free_extent_buffer(right);
|
|
return 1;
|
|
}
|
|
|
|
for (i = left_nritems - 1; i >= 1; i--) {
|
|
item = btrfs_item_nr(left, i);
|
|
|
|
if (path->slots[0] == i)
|
|
push_space += data_size + sizeof(*item);
|
|
|
|
if (!left->map_token) {
|
|
map_extent_buffer(left, (unsigned long)item,
|
|
sizeof(struct btrfs_item),
|
|
&left->map_token, &left->kaddr,
|
|
&left->map_start, &left->map_len,
|
|
KM_USER1);
|
|
}
|
|
|
|
this_item_size = btrfs_item_size(left, item);
|
|
if (this_item_size + sizeof(*item) + push_space > free_space)
|
|
break;
|
|
push_items++;
|
|
push_space += this_item_size + sizeof(*item);
|
|
}
|
|
if (left->map_token) {
|
|
unmap_extent_buffer(left, left->map_token, KM_USER1);
|
|
left->map_token = NULL;
|
|
}
|
|
|
|
if (push_items == 0) {
|
|
free_extent_buffer(right);
|
|
return 1;
|
|
}
|
|
|
|
if (push_items == left_nritems)
|
|
WARN_ON(1);
|
|
|
|
/* push left to right */
|
|
right_nritems = btrfs_header_nritems(right);
|
|
push_space = btrfs_item_end_nr(left, left_nritems - push_items);
|
|
push_space -= leaf_data_end(root, left);
|
|
|
|
/* make room in the right data area */
|
|
data_end = leaf_data_end(root, right);
|
|
memmove_extent_buffer(right,
|
|
btrfs_leaf_data(right) + data_end - push_space,
|
|
btrfs_leaf_data(right) + data_end,
|
|
BTRFS_LEAF_DATA_SIZE(root) - data_end);
|
|
|
|
/* copy from the left data area */
|
|
copy_extent_buffer(right, left, btrfs_leaf_data(right) +
|
|
BTRFS_LEAF_DATA_SIZE(root) - push_space,
|
|
btrfs_leaf_data(left) + leaf_data_end(root, left),
|
|
push_space);
|
|
|
|
memmove_extent_buffer(right, btrfs_item_nr_offset(push_items),
|
|
btrfs_item_nr_offset(0),
|
|
right_nritems * sizeof(struct btrfs_item));
|
|
|
|
/* copy the items from left to right */
|
|
copy_extent_buffer(right, left, btrfs_item_nr_offset(0),
|
|
btrfs_item_nr_offset(left_nritems - push_items),
|
|
push_items * sizeof(struct btrfs_item));
|
|
|
|
/* update the item pointers */
|
|
right_nritems += push_items;
|
|
btrfs_set_header_nritems(right, right_nritems);
|
|
push_space = BTRFS_LEAF_DATA_SIZE(root);
|
|
|
|
for (i = 0; i < right_nritems; i++) {
|
|
item = btrfs_item_nr(right, i);
|
|
if (!right->map_token) {
|
|
map_extent_buffer(right, (unsigned long)item,
|
|
sizeof(struct btrfs_item),
|
|
&right->map_token, &right->kaddr,
|
|
&right->map_start, &right->map_len,
|
|
KM_USER1);
|
|
}
|
|
push_space -= btrfs_item_size(right, item);
|
|
btrfs_set_item_offset(right, item, push_space);
|
|
}
|
|
|
|
if (right->map_token) {
|
|
unmap_extent_buffer(right, right->map_token, KM_USER1);
|
|
right->map_token = NULL;
|
|
}
|
|
left_nritems -= push_items;
|
|
btrfs_set_header_nritems(left, left_nritems);
|
|
|
|
btrfs_mark_buffer_dirty(left);
|
|
btrfs_mark_buffer_dirty(right);
|
|
|
|
btrfs_item_key(right, &disk_key, 0);
|
|
btrfs_set_node_key(upper, &disk_key, slot + 1);
|
|
btrfs_mark_buffer_dirty(upper);
|
|
|
|
/* then fixup the leaf pointer in the path */
|
|
if (path->slots[0] >= left_nritems) {
|
|
path->slots[0] -= left_nritems;
|
|
free_extent_buffer(path->nodes[0]);
|
|
path->nodes[0] = right;
|
|
path->slots[1] += 1;
|
|
} else {
|
|
free_extent_buffer(right);
|
|
}
|
|
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_trans_handle *trans, struct btrfs_root
|
|
*root, struct btrfs_path *path, int data_size)
|
|
{
|
|
struct btrfs_disk_key disk_key;
|
|
struct extent_buffer *right = path->nodes[0];
|
|
struct extent_buffer *left;
|
|
int slot;
|
|
int i;
|
|
int free_space;
|
|
int push_space = 0;
|
|
int push_items = 0;
|
|
struct btrfs_item *item;
|
|
u32 old_left_nritems;
|
|
u32 right_nritems;
|
|
int ret = 0;
|
|
int wret;
|
|
u32 this_item_size;
|
|
u32 old_left_item_size;
|
|
|
|
slot = path->slots[1];
|
|
if (slot == 0)
|
|
return 1;
|
|
if (!path->nodes[1])
|
|
return 1;
|
|
|
|
right_nritems = btrfs_header_nritems(right);
|
|
if (right_nritems == 0) {
|
|
return 1;
|
|
}
|
|
|
|
left = read_tree_block(root, btrfs_node_blockptr(path->nodes[1],
|
|
slot - 1), root->leafsize);
|
|
free_space = btrfs_leaf_free_space(root, left);
|
|
if (free_space < data_size + sizeof(struct btrfs_item)) {
|
|
free_extent_buffer(left);
|
|
return 1;
|
|
}
|
|
|
|
/* cow and double check */
|
|
ret = btrfs_cow_block(trans, root, left,
|
|
path->nodes[1], slot - 1, &left);
|
|
if (ret) {
|
|
/* we hit -ENOSPC, but it isn't fatal here */
|
|
free_extent_buffer(left);
|
|
return 1;
|
|
}
|
|
|
|
free_space = btrfs_leaf_free_space(root, left);
|
|
if (free_space < data_size + sizeof(struct btrfs_item)) {
|
|
free_extent_buffer(left);
|
|
return 1;
|
|
}
|
|
|
|
for (i = 0; i < right_nritems - 1; i++) {
|
|
item = btrfs_item_nr(right, i);
|
|
if (!right->map_token) {
|
|
map_extent_buffer(right, (unsigned long)item,
|
|
sizeof(struct btrfs_item),
|
|
&right->map_token, &right->kaddr,
|
|
&right->map_start, &right->map_len,
|
|
KM_USER1);
|
|
}
|
|
|
|
if (path->slots[0] == i)
|
|
push_space += data_size + sizeof(*item);
|
|
|
|
this_item_size = btrfs_item_size(right, item);
|
|
if (this_item_size + sizeof(*item) + push_space > free_space)
|
|
break;
|
|
|
|
push_items++;
|
|
push_space += this_item_size + sizeof(*item);
|
|
}
|
|
|
|
if (right->map_token) {
|
|
unmap_extent_buffer(right, right->map_token, KM_USER1);
|
|
right->map_token = NULL;
|
|
}
|
|
|
|
if (push_items == 0) {
|
|
free_extent_buffer(left);
|
|
return 1;
|
|
}
|
|
if (push_items == btrfs_header_nritems(right))
|
|
WARN_ON(1);
|
|
|
|
/* push data from right to left */
|
|
copy_extent_buffer(left, right,
|
|
btrfs_item_nr_offset(btrfs_header_nritems(left)),
|
|
btrfs_item_nr_offset(0),
|
|
push_items * sizeof(struct btrfs_item));
|
|
|
|
push_space = BTRFS_LEAF_DATA_SIZE(root) -
|
|
btrfs_item_offset_nr(right, push_items -1);
|
|
|
|
copy_extent_buffer(left, right, btrfs_leaf_data(left) +
|
|
leaf_data_end(root, left) - push_space,
|
|
btrfs_leaf_data(right) +
|
|
btrfs_item_offset_nr(right, push_items - 1),
|
|
push_space);
|
|
old_left_nritems = btrfs_header_nritems(left);
|
|
BUG_ON(old_left_nritems < 0);
|
|
|
|
old_left_item_size = btrfs_item_offset_nr(left, old_left_nritems - 1);
|
|
for (i = old_left_nritems; i < old_left_nritems + push_items; i++) {
|
|
u32 ioff;
|
|
|
|
item = btrfs_item_nr(left, i);
|
|
if (!left->map_token) {
|
|
map_extent_buffer(left, (unsigned long)item,
|
|
sizeof(struct btrfs_item),
|
|
&left->map_token, &left->kaddr,
|
|
&left->map_start, &left->map_len,
|
|
KM_USER1);
|
|
}
|
|
|
|
ioff = btrfs_item_offset(left, item);
|
|
btrfs_set_item_offset(left, item,
|
|
ioff - (BTRFS_LEAF_DATA_SIZE(root) - old_left_item_size));
|
|
}
|
|
btrfs_set_header_nritems(left, old_left_nritems + push_items);
|
|
if (left->map_token) {
|
|
unmap_extent_buffer(left, left->map_token, KM_USER1);
|
|
left->map_token = NULL;
|
|
}
|
|
|
|
/* fixup right node */
|
|
push_space = btrfs_item_offset_nr(right, push_items - 1) -
|
|
leaf_data_end(root, right);
|
|
memmove_extent_buffer(right, btrfs_leaf_data(right) +
|
|
BTRFS_LEAF_DATA_SIZE(root) - push_space,
|
|
btrfs_leaf_data(right) +
|
|
leaf_data_end(root, right), push_space);
|
|
|
|
memmove_extent_buffer(right, btrfs_item_nr_offset(0),
|
|
btrfs_item_nr_offset(push_items),
|
|
(btrfs_header_nritems(right) - push_items) *
|
|
sizeof(struct btrfs_item));
|
|
|
|
right_nritems = btrfs_header_nritems(right) - push_items;
|
|
btrfs_set_header_nritems(right, right_nritems);
|
|
push_space = BTRFS_LEAF_DATA_SIZE(root);
|
|
|
|
for (i = 0; i < right_nritems; i++) {
|
|
item = btrfs_item_nr(right, i);
|
|
|
|
if (!right->map_token) {
|
|
map_extent_buffer(right, (unsigned long)item,
|
|
sizeof(struct btrfs_item),
|
|
&right->map_token, &right->kaddr,
|
|
&right->map_start, &right->map_len,
|
|
KM_USER1);
|
|
}
|
|
|
|
push_space = push_space - btrfs_item_size(right, item);
|
|
btrfs_set_item_offset(right, item, push_space);
|
|
}
|
|
if (right->map_token) {
|
|
unmap_extent_buffer(right, right->map_token, KM_USER1);
|
|
right->map_token = NULL;
|
|
}
|
|
|
|
btrfs_mark_buffer_dirty(left);
|
|
btrfs_mark_buffer_dirty(right);
|
|
|
|
btrfs_item_key(right, &disk_key, 0);
|
|
wret = fixup_low_keys(trans, root, path, &disk_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;
|
|
free_extent_buffer(path->nodes[0]);
|
|
path->nodes[0] = left;
|
|
path->slots[1] -= 1;
|
|
} else {
|
|
free_extent_buffer(left);
|
|
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_trans_handle *trans, struct btrfs_root
|
|
*root, struct btrfs_key *ins_key,
|
|
struct btrfs_path *path, int data_size, int extend)
|
|
{
|
|
struct extent_buffer *l;
|
|
u32 nritems;
|
|
int mid;
|
|
int slot;
|
|
struct extent_buffer *right;
|
|
int space_needed = data_size + sizeof(struct btrfs_item);
|
|
int data_copy_size;
|
|
int rt_data_off;
|
|
int i;
|
|
int ret = 0;
|
|
int wret;
|
|
int double_split;
|
|
int num_doubles = 0;
|
|
struct btrfs_disk_key disk_key;
|
|
|
|
if (extend)
|
|
space_needed = data_size;
|
|
|
|
/* first try to make some room by pushing left and right */
|
|
if (ins_key->type != BTRFS_DIR_ITEM_KEY) {
|
|
wret = push_leaf_right(trans, root, path, data_size);
|
|
if (wret < 0) {
|
|
return wret;
|
|
}
|
|
if (wret) {
|
|
wret = push_leaf_left(trans, root, path, data_size);
|
|
if (wret < 0)
|
|
return wret;
|
|
}
|
|
l = path->nodes[0];
|
|
|
|
/* did the pushes work? */
|
|
if (btrfs_leaf_free_space(root, l) >= space_needed)
|
|
return 0;
|
|
}
|
|
|
|
if (!path->nodes[1]) {
|
|
ret = insert_new_root(trans, root, path, 1);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
again:
|
|
double_split = 0;
|
|
l = path->nodes[0];
|
|
slot = path->slots[0];
|
|
nritems = btrfs_header_nritems(l);
|
|
mid = (nritems + 1)/ 2;
|
|
|
|
right = btrfs_alloc_free_block(trans, root, root->leafsize,
|
|
l->start, 0);
|
|
if (IS_ERR(right))
|
|
return PTR_ERR(right);
|
|
|
|
memset_extent_buffer(right, 0, 0, sizeof(struct btrfs_header));
|
|
btrfs_set_header_bytenr(right, right->start);
|
|
btrfs_set_header_generation(right, trans->transid);
|
|
btrfs_set_header_owner(right, root->root_key.objectid);
|
|
btrfs_set_header_level(right, 0);
|
|
write_extent_buffer(right, root->fs_info->fsid,
|
|
(unsigned long)btrfs_header_fsid(right),
|
|
BTRFS_FSID_SIZE);
|
|
if (mid <= slot) {
|
|
if (nritems == 1 ||
|
|
leaf_space_used(l, mid, nritems - mid) + space_needed >
|
|
BTRFS_LEAF_DATA_SIZE(root)) {
|
|
if (slot >= nritems) {
|
|
btrfs_cpu_key_to_disk(&disk_key, ins_key);
|
|
btrfs_set_header_nritems(right, 0);
|
|
wret = insert_ptr(trans, root, path,
|
|
&disk_key, right->start,
|
|
path->slots[1] + 1, 1);
|
|
if (wret)
|
|
ret = wret;
|
|
free_extent_buffer(path->nodes[0]);
|
|
path->nodes[0] = right;
|
|
path->slots[0] = 0;
|
|
path->slots[1] += 1;
|
|
return ret;
|
|
}
|
|
mid = slot;
|
|
if (mid != nritems &&
|
|
leaf_space_used(l, mid, nritems - mid) +
|
|
space_needed > BTRFS_LEAF_DATA_SIZE(root)) {
|
|
double_split = 1;
|
|
}
|
|
}
|
|
} else {
|
|
if (leaf_space_used(l, 0, mid + 1) + space_needed >
|
|
BTRFS_LEAF_DATA_SIZE(root)) {
|
|
if (!extend && slot == 0) {
|
|
btrfs_cpu_key_to_disk(&disk_key, ins_key);
|
|
btrfs_set_header_nritems(right, 0);
|
|
wret = insert_ptr(trans, root, path,
|
|
&disk_key,
|
|
right->start,
|
|
path->slots[1], 1);
|
|
if (wret)
|
|
ret = wret;
|
|
free_extent_buffer(path->nodes[0]);
|
|
path->nodes[0] = right;
|
|
path->slots[0] = 0;
|
|
if (path->slots[1] == 0) {
|
|
wret = fixup_low_keys(trans, root,
|
|
path, &disk_key, 1);
|
|
if (wret)
|
|
ret = wret;
|
|
}
|
|
return ret;
|
|
} else if (extend && slot == 0) {
|
|
mid = 1;
|
|
} else {
|
|
mid = slot;
|
|
if (mid != nritems &&
|
|
leaf_space_used(l, mid, nritems - mid) +
|
|
space_needed > BTRFS_LEAF_DATA_SIZE(root)) {
|
|
double_split = 1;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
nritems = nritems - mid;
|
|
btrfs_set_header_nritems(right, nritems);
|
|
data_copy_size = btrfs_item_end_nr(l, mid) - leaf_data_end(root, l);
|
|
|
|
copy_extent_buffer(right, l, btrfs_item_nr_offset(0),
|
|
btrfs_item_nr_offset(mid),
|
|
nritems * sizeof(struct btrfs_item));
|
|
|
|
copy_extent_buffer(right, l,
|
|
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_nr(l, mid);
|
|
|
|
for (i = 0; i < nritems; i++) {
|
|
struct btrfs_item *item = btrfs_item_nr(right, i);
|
|
u32 ioff;
|
|
|
|
if (!right->map_token) {
|
|
map_extent_buffer(right, (unsigned long)item,
|
|
sizeof(struct btrfs_item),
|
|
&right->map_token, &right->kaddr,
|
|
&right->map_start, &right->map_len,
|
|
KM_USER1);
|
|
}
|
|
|
|
ioff = btrfs_item_offset(right, item);
|
|
btrfs_set_item_offset(right, item, ioff + rt_data_off);
|
|
}
|
|
|
|
if (right->map_token) {
|
|
unmap_extent_buffer(right, right->map_token, KM_USER1);
|
|
right->map_token = NULL;
|
|
}
|
|
|
|
btrfs_set_header_nritems(l, mid);
|
|
ret = 0;
|
|
btrfs_item_key(right, &disk_key, 0);
|
|
wret = insert_ptr(trans, root, path, &disk_key, right->start,
|
|
path->slots[1] + 1, 1);
|
|
if (wret)
|
|
ret = wret;
|
|
|
|
btrfs_mark_buffer_dirty(right);
|
|
btrfs_mark_buffer_dirty(l);
|
|
BUG_ON(path->slots[0] != slot);
|
|
|
|
if (mid <= slot) {
|
|
free_extent_buffer(path->nodes[0]);
|
|
path->nodes[0] = right;
|
|
path->slots[0] -= mid;
|
|
path->slots[1] += 1;
|
|
} else
|
|
free_extent_buffer(right);
|
|
|
|
BUG_ON(path->slots[0] < 0);
|
|
|
|
if (double_split) {
|
|
BUG_ON(num_doubles != 0);
|
|
num_doubles++;
|
|
goto again;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
int btrfs_truncate_item(struct btrfs_trans_handle *trans,
|
|
struct btrfs_root *root,
|
|
struct btrfs_path *path,
|
|
u32 new_size)
|
|
{
|
|
int ret = 0;
|
|
int slot;
|
|
int slot_orig;
|
|
struct extent_buffer *leaf;
|
|
struct btrfs_item *item;
|
|
u32 nritems;
|
|
unsigned int data_end;
|
|
unsigned int old_data_start;
|
|
unsigned int old_size;
|
|
unsigned int size_diff;
|
|
int i;
|
|
|
|
slot_orig = path->slots[0];
|
|
leaf = path->nodes[0];
|
|
|
|
nritems = btrfs_header_nritems(leaf);
|
|
data_end = leaf_data_end(root, leaf);
|
|
|
|
slot = path->slots[0];
|
|
old_data_start = btrfs_item_offset_nr(leaf, slot);
|
|
old_size = btrfs_item_size_nr(leaf, slot); BUG_ON(old_size <= new_size);
|
|
size_diff = old_size - new_size;
|
|
|
|
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;
|
|
item = btrfs_item_nr(leaf, i);
|
|
|
|
if (!leaf->map_token) {
|
|
map_extent_buffer(leaf, (unsigned long)item,
|
|
sizeof(struct btrfs_item),
|
|
&leaf->map_token, &leaf->kaddr,
|
|
&leaf->map_start, &leaf->map_len,
|
|
KM_USER1);
|
|
}
|
|
|
|
ioff = btrfs_item_offset(leaf, item);
|
|
btrfs_set_item_offset(leaf, item, ioff + size_diff);
|
|
}
|
|
|
|
if (leaf->map_token) {
|
|
unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
|
|
leaf->map_token = NULL;
|
|
}
|
|
|
|
/* shift the data */
|
|
memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
|
|
data_end + size_diff, btrfs_leaf_data(leaf) +
|
|
data_end, old_data_start + new_size - data_end);
|
|
|
|
item = btrfs_item_nr(leaf, slot);
|
|
btrfs_set_item_size(leaf, item, new_size);
|
|
btrfs_mark_buffer_dirty(leaf);
|
|
|
|
ret = 0;
|
|
if (btrfs_leaf_free_space(root, leaf) < 0) {
|
|
btrfs_print_leaf(root, leaf);
|
|
BUG();
|
|
}
|
|
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 extent_buffer *leaf;
|
|
struct btrfs_item *item;
|
|
u32 nritems;
|
|
unsigned int data_end;
|
|
unsigned int old_data;
|
|
unsigned int old_size;
|
|
int i;
|
|
|
|
slot_orig = path->slots[0];
|
|
leaf = path->nodes[0];
|
|
|
|
nritems = btrfs_header_nritems(leaf);
|
|
data_end = leaf_data_end(root, leaf);
|
|
|
|
if (btrfs_leaf_free_space(root, leaf) < data_size) {
|
|
btrfs_print_leaf(root, leaf);
|
|
BUG();
|
|
}
|
|
slot = path->slots[0];
|
|
old_data = btrfs_item_end_nr(leaf, slot);
|
|
|
|
BUG_ON(slot < 0);
|
|
if (slot >= nritems) {
|
|
btrfs_print_leaf(root, leaf);
|
|
printk("slot %d too large, nritems %d\n", slot, nritems);
|
|
BUG_ON(1);
|
|
}
|
|
|
|
/*
|
|
* item0..itemN ... dataN.offset..dataN.size .. data0.size
|
|
*/
|
|
/* first correct the data pointers */
|
|
for (i = slot; i < nritems; i++) {
|
|
u32 ioff;
|
|
item = btrfs_item_nr(leaf, i);
|
|
|
|
if (!leaf->map_token) {
|
|
map_extent_buffer(leaf, (unsigned long)item,
|
|
sizeof(struct btrfs_item),
|
|
&leaf->map_token, &leaf->kaddr,
|
|
&leaf->map_start, &leaf->map_len,
|
|
KM_USER1);
|
|
}
|
|
ioff = btrfs_item_offset(leaf, item);
|
|
btrfs_set_item_offset(leaf, item, ioff - data_size);
|
|
}
|
|
|
|
if (leaf->map_token) {
|
|
unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
|
|
leaf->map_token = NULL;
|
|
}
|
|
|
|
/* shift the data */
|
|
memmove_extent_buffer(leaf, 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_nr(leaf, slot);
|
|
item = btrfs_item_nr(leaf, slot);
|
|
btrfs_set_item_size(leaf, item, old_size + data_size);
|
|
btrfs_mark_buffer_dirty(leaf);
|
|
|
|
ret = 0;
|
|
if (btrfs_leaf_free_space(root, leaf) < 0) {
|
|
btrfs_print_leaf(root, leaf);
|
|
BUG();
|
|
}
|
|
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_empty_item(struct btrfs_trans_handle *trans,
|
|
struct btrfs_root *root,
|
|
struct btrfs_path *path,
|
|
struct btrfs_key *cpu_key, u32 data_size)
|
|
{
|
|
struct extent_buffer *leaf;
|
|
struct btrfs_item *item;
|
|
int ret = 0;
|
|
int slot;
|
|
int slot_orig;
|
|
u32 nritems;
|
|
unsigned int data_end;
|
|
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();
|
|
|
|
ret = btrfs_search_slot(trans, root, cpu_key, path, data_size, 1);
|
|
if (ret == 0) {
|
|
return -EEXIST;
|
|
}
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
slot_orig = path->slots[0];
|
|
leaf = path->nodes[0];
|
|
|
|
nritems = btrfs_header_nritems(leaf);
|
|
data_end = leaf_data_end(root, leaf);
|
|
|
|
if (btrfs_leaf_free_space(root, leaf) <
|
|
sizeof(struct btrfs_item) + data_size) {
|
|
btrfs_print_leaf(root, leaf);
|
|
printk("not enough freespace need %u have %d\n",
|
|
data_size, btrfs_leaf_free_space(root, leaf));
|
|
BUG();
|
|
}
|
|
|
|
slot = path->slots[0];
|
|
BUG_ON(slot < 0);
|
|
|
|
if (slot != nritems) {
|
|
int i;
|
|
unsigned int old_data = btrfs_item_end_nr(leaf, slot);
|
|
|
|
if (old_data < data_end) {
|
|
btrfs_print_leaf(root, leaf);
|
|
printk("slot %d old_data %d data_end %d\n",
|
|
slot, old_data, data_end);
|
|
BUG_ON(1);
|
|
}
|
|
/*
|
|
* item0..itemN ... dataN.offset..dataN.size .. data0.size
|
|
*/
|
|
/* first correct the data pointers */
|
|
WARN_ON(leaf->map_token);
|
|
for (i = slot; i < nritems; i++) {
|
|
u32 ioff;
|
|
|
|
item = btrfs_item_nr(leaf, i);
|
|
if (!leaf->map_token) {
|
|
map_extent_buffer(leaf, (unsigned long)item,
|
|
sizeof(struct btrfs_item),
|
|
&leaf->map_token, &leaf->kaddr,
|
|
&leaf->map_start, &leaf->map_len,
|
|
KM_USER1);
|
|
}
|
|
|
|
ioff = btrfs_item_offset(leaf, item);
|
|
btrfs_set_item_offset(leaf, item, ioff - data_size);
|
|
}
|
|
if (leaf->map_token) {
|
|
unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
|
|
leaf->map_token = NULL;
|
|
}
|
|
|
|
/* shift the items */
|
|
memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + 1),
|
|
btrfs_item_nr_offset(slot),
|
|
(nritems - slot) * sizeof(struct btrfs_item));
|
|
|
|
/* shift the data */
|
|
memmove_extent_buffer(leaf, 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 */
|
|
btrfs_set_item_key(leaf, &disk_key, slot);
|
|
item = btrfs_item_nr(leaf, slot);
|
|
btrfs_set_item_offset(leaf, item, data_end - data_size);
|
|
btrfs_set_item_size(leaf, item, data_size);
|
|
btrfs_set_header_nritems(leaf, nritems + 1);
|
|
btrfs_mark_buffer_dirty(leaf);
|
|
|
|
ret = 0;
|
|
if (slot == 0)
|
|
ret = fixup_low_keys(trans, root, path, &disk_key, 1);
|
|
|
|
if (btrfs_leaf_free_space(root, leaf) < 0) {
|
|
btrfs_print_leaf(root, leaf);
|
|
BUG();
|
|
}
|
|
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.
|
|
*/
|
|
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;
|
|
struct extent_buffer *leaf;
|
|
unsigned long ptr;
|
|
|
|
path = btrfs_alloc_path();
|
|
BUG_ON(!path);
|
|
ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size);
|
|
if (!ret) {
|
|
leaf = path->nodes[0];
|
|
ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
|
|
write_extent_buffer(leaf, data, ptr, data_size);
|
|
btrfs_mark_buffer_dirty(leaf);
|
|
}
|
|
btrfs_free_path(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_trans_handle *trans, struct btrfs_root *root,
|
|
struct btrfs_path *path, int level, int slot)
|
|
{
|
|
struct extent_buffer *parent = path->nodes[level];
|
|
u32 nritems;
|
|
int ret = 0;
|
|
int wret;
|
|
|
|
nritems = btrfs_header_nritems(parent);
|
|
if (slot != nritems -1) {
|
|
memmove_extent_buffer(parent,
|
|
btrfs_node_key_ptr_offset(slot),
|
|
btrfs_node_key_ptr_offset(slot + 1),
|
|
sizeof(struct btrfs_key_ptr) *
|
|
(nritems - slot - 1));
|
|
}
|
|
nritems--;
|
|
btrfs_set_header_nritems(parent, nritems);
|
|
if (nritems == 0 && parent == root->node) {
|
|
BUG_ON(btrfs_header_level(root->node) != 1);
|
|
/* just turn the root into a leaf and break */
|
|
btrfs_set_header_level(root->node, 0);
|
|
} else if (slot == 0) {
|
|
struct btrfs_disk_key disk_key;
|
|
|
|
btrfs_node_key(parent, &disk_key, 0);
|
|
wret = fixup_low_keys(trans, root, path, &disk_key, level + 1);
|
|
if (wret)
|
|
ret = wret;
|
|
}
|
|
btrfs_mark_buffer_dirty(parent);
|
|
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_trans_handle *trans, struct btrfs_root *root,
|
|
struct btrfs_path *path)
|
|
{
|
|
int slot;
|
|
struct extent_buffer *leaf;
|
|
struct btrfs_item *item;
|
|
int doff;
|
|
int dsize;
|
|
int ret = 0;
|
|
int wret;
|
|
u32 nritems;
|
|
|
|
leaf = path->nodes[0];
|
|
slot = path->slots[0];
|
|
doff = btrfs_item_offset_nr(leaf, slot);
|
|
dsize = btrfs_item_size_nr(leaf, slot);
|
|
nritems = btrfs_header_nritems(leaf);
|
|
|
|
if (slot != nritems - 1) {
|
|
int i;
|
|
int data_end = leaf_data_end(root, leaf);
|
|
|
|
memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
|
|
data_end + dsize,
|
|
btrfs_leaf_data(leaf) + data_end,
|
|
doff - data_end);
|
|
|
|
for (i = slot + 1; i < nritems; i++) {
|
|
u32 ioff;
|
|
|
|
item = btrfs_item_nr(leaf, i);
|
|
if (!leaf->map_token) {
|
|
map_extent_buffer(leaf, (unsigned long)item,
|
|
sizeof(struct btrfs_item),
|
|
&leaf->map_token, &leaf->kaddr,
|
|
&leaf->map_start, &leaf->map_len,
|
|
KM_USER1);
|
|
}
|
|
ioff = btrfs_item_offset(leaf, item);
|
|
btrfs_set_item_offset(leaf, item, ioff + dsize);
|
|
}
|
|
|
|
if (leaf->map_token) {
|
|
unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
|
|
leaf->map_token = NULL;
|
|
}
|
|
|
|
memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot),
|
|
btrfs_item_nr_offset(slot + 1),
|
|
sizeof(struct btrfs_item) *
|
|
(nritems - slot - 1));
|
|
}
|
|
btrfs_set_header_nritems(leaf, nritems - 1);
|
|
nritems--;
|
|
|
|
/* delete the leaf if we've emptied it */
|
|
if (nritems == 0) {
|
|
if (leaf == root->node) {
|
|
btrfs_set_header_level(leaf, 0);
|
|
} else {
|
|
clean_tree_block(trans, root, leaf);
|
|
wait_on_tree_block_writeback(root, leaf);
|
|
wret = del_ptr(trans, root, path, 1, path->slots[1]);
|
|
if (wret)
|
|
ret = wret;
|
|
wret = btrfs_free_extent(trans, root,
|
|
leaf->start, leaf->len, 1);
|
|
if (wret)
|
|
ret = wret;
|
|
}
|
|
} else {
|
|
int used = leaf_space_used(leaf, 0, nritems);
|
|
if (slot == 0) {
|
|
struct btrfs_disk_key disk_key;
|
|
|
|
btrfs_item_key(leaf, &disk_key, 0);
|
|
wret = fixup_low_keys(trans, root, path,
|
|
&disk_key, 1);
|
|
if (wret)
|
|
ret = wret;
|
|
}
|
|
|
|
/* delete the leaf if it is mostly empty */
|
|
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];
|
|
extent_buffer_get(leaf);
|
|
|
|
wret = push_leaf_right(trans, root, path, 1);
|
|
if (wret < 0 && wret != -ENOSPC)
|
|
ret = wret;
|
|
|
|
if (path->nodes[0] == leaf &&
|
|
btrfs_header_nritems(leaf)) {
|
|
wret = push_leaf_left(trans, root, path, 1);
|
|
if (wret < 0 && wret != -ENOSPC)
|
|
ret = wret;
|
|
}
|
|
|
|
if (btrfs_header_nritems(leaf) == 0) {
|
|
u64 bytenr = leaf->start;
|
|
u32 blocksize = leaf->len;
|
|
|
|
clean_tree_block(trans, root, leaf);
|
|
wait_on_tree_block_writeback(root, leaf);
|
|
|
|
wret = del_ptr(trans, root, path, 1, slot);
|
|
if (wret)
|
|
ret = wret;
|
|
|
|
free_extent_buffer(leaf);
|
|
wret = btrfs_free_extent(trans, root, bytenr,
|
|
blocksize, 1);
|
|
if (wret)
|
|
ret = wret;
|
|
} else {
|
|
btrfs_mark_buffer_dirty(leaf);
|
|
free_extent_buffer(leaf);
|
|
}
|
|
} else {
|
|
btrfs_mark_buffer_dirty(leaf);
|
|
}
|
|
}
|
|
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 bytenr;
|
|
struct extent_buffer *c;
|
|
struct extent_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)) {
|
|
level++;
|
|
continue;
|
|
}
|
|
|
|
bytenr = btrfs_node_blockptr(c, slot);
|
|
if (next)
|
|
free_extent_buffer(next);
|
|
|
|
if (path->reada)
|
|
reada_for_search(root, path, level, slot);
|
|
|
|
next = read_tree_block(root, bytenr,
|
|
btrfs_level_size(root, level -1));
|
|
break;
|
|
}
|
|
path->slots[level] = slot;
|
|
while(1) {
|
|
level--;
|
|
c = path->nodes[level];
|
|
free_extent_buffer(c);
|
|
path->nodes[level] = next;
|
|
path->slots[level] = 0;
|
|
if (!level)
|
|
break;
|
|
if (path->reada)
|
|
reada_for_search(root, path, level, 0);
|
|
next = read_tree_block(root, btrfs_node_blockptr(next, 0),
|
|
btrfs_level_size(root, level - 1));
|
|
}
|
|
return 0;
|
|
}
|