| /* |
| * 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 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) |
| 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, 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; |
| } |