/* * Copyright (C) 2007 Oracle. All rights reserved. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public * License v2 as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public * License along with this program; if not, write to the * Free Software Foundation, Inc., 59 Temple Place - Suite 330, * Boston, MA 021110-1307, USA. */ #include <linux/sched.h> #include "ctree.h" #include "disk-io.h" #include "print-tree.h" #include "transaction.h" #include "locking.h" /* * Defrag all the leaves in a given btree. * Read all the leaves and try to get key order to * better reflect disk order */ int btrfs_defrag_leaves(struct btrfs_trans_handle *trans, struct btrfs_root *root) { struct btrfs_path *path = NULL; struct btrfs_key key; int ret = 0; int wret; int level; int is_extent = 0; int next_key_ret = 0; u64 last_ret = 0; u64 min_trans = 0; if (root->fs_info->extent_root == root) { /* * there's recursion here right now in the tree locking, * we can't defrag the extent root without deadlock */ goto out; } if (root->ref_cows == 0 && !is_extent) goto out; if (btrfs_test_opt(root, SSD)) goto out; path = btrfs_alloc_path(); if (!path) return -ENOMEM; level = btrfs_header_level(root->node); if (level == 0) goto out; if (root->defrag_progress.objectid == 0) { struct extent_buffer *root_node; u32 nritems; root_node = btrfs_lock_root_node(root); btrfs_set_lock_blocking(root_node); nritems = btrfs_header_nritems(root_node); root->defrag_max.objectid = 0; /* from above we know this is not a leaf */ btrfs_node_key_to_cpu(root_node, &root->defrag_max, nritems - 1); btrfs_tree_unlock(root_node); free_extent_buffer(root_node); memset(&key, 0, sizeof(key)); } else { memcpy(&key, &root->defrag_progress, sizeof(key)); } path->keep_locks = 1; ret = btrfs_search_forward(root, &key, NULL, path, min_trans); if (ret < 0) goto out; if (ret > 0) { ret = 0; goto out; } btrfs_release_path(path); wret = btrfs_search_slot(trans, root, &key, path, 0, 1); if (wret < 0) { ret = wret; goto out; } if (!path->nodes[1]) { ret = 0; goto out; } path->slots[1] = btrfs_header_nritems(path->nodes[1]); next_key_ret = btrfs_find_next_key(root, path, &key, 1, min_trans); ret = btrfs_realloc_node(trans, root, path->nodes[1], 0, &last_ret, &root->defrag_progress); if (ret) { WARN_ON(ret == -EAGAIN); goto out; } if (next_key_ret == 0) { memcpy(&root->defrag_progress, &key, sizeof(key)); ret = -EAGAIN; } out: if (path) btrfs_free_path(path); if (ret == -EAGAIN) { if (root->defrag_max.objectid > root->defrag_progress.objectid) goto done; if (root->defrag_max.type > root->defrag_progress.type) goto done; if (root->defrag_max.offset > root->defrag_progress.offset) goto done; ret = 0; } done: if (ret != -EAGAIN) { memset(&root->defrag_progress, 0, sizeof(root->defrag_progress)); root->defrag_trans_start = trans->transid; } return ret; }