2 * Copyright (C) 2007 Oracle. All rights reserved.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
19 #include <linux/sched.h>
22 #include "print-tree.h"
23 #include "transaction.h"
25 static void reada_defrag(struct btrfs_root *root,
26 struct btrfs_node *node)
33 nritems = btrfs_header_nritems(&node->header);
34 for (i = 0; i < nritems; i++) {
35 blocknr = btrfs_node_blockptr(node, i);
36 ret = readahead_tree_block(root, blocknr);
42 static int defrag_walk_down(struct btrfs_trans_handle *trans,
43 struct btrfs_root *root,
44 struct btrfs_path *path, int *level,
47 struct buffer_head *next;
48 struct buffer_head *cur;
53 WARN_ON(*level >= BTRFS_MAX_LEVEL);
57 WARN_ON(*level >= BTRFS_MAX_LEVEL);
58 cur = path->nodes[*level];
60 if (!cache_only && *level > 1 && path->slots[*level] == 0)
61 reada_defrag(root, btrfs_buffer_node(cur));
63 if (btrfs_header_level(btrfs_buffer_header(cur)) != *level)
66 if (path->slots[*level] >=
67 btrfs_header_nritems(btrfs_buffer_header(cur)))
71 ret = btrfs_realloc_node(trans, root,
76 blocknr = btrfs_node_blockptr(btrfs_buffer_node(cur),
80 next = btrfs_find_tree_block(root, blocknr);
81 if (!next || !buffer_uptodate(next) ||
82 buffer_locked(next)) {
84 path->slots[*level]++;
88 next = read_tree_block(root, blocknr);
90 ret = btrfs_cow_block(trans, root, next, path->nodes[*level],
91 path->slots[*level], &next);
93 ret = btrfs_realloc_node(trans, root, next, cache_only);
96 if (path->nodes[*level-1])
97 btrfs_block_release(root, path->nodes[*level-1]);
98 path->nodes[*level-1] = next;
99 *level = btrfs_header_level(btrfs_buffer_header(next));
100 path->slots[*level] = 0;
103 WARN_ON(*level >= BTRFS_MAX_LEVEL);
104 btrfs_block_release(root, path->nodes[*level]);
105 path->nodes[*level] = NULL;
111 static int defrag_walk_up(struct btrfs_trans_handle *trans,
112 struct btrfs_root *root,
113 struct btrfs_path *path, int *level,
118 struct btrfs_node *node;
120 for(i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
121 slot = path->slots[i];
122 if (slot < btrfs_header_nritems(
123 btrfs_buffer_header(path->nodes[i])) - 1) {
126 node = btrfs_buffer_node(path->nodes[i]);
128 btrfs_disk_key_to_cpu(&root->defrag_progress,
129 &node->ptrs[path->slots[i]].key);
130 root->defrag_level = i;
133 btrfs_block_release(root, path->nodes[*level]);
134 path->nodes[*level] = NULL;
141 int btrfs_defrag_leaves(struct btrfs_trans_handle *trans,
142 struct btrfs_root *root, int cache_only)
144 struct btrfs_path *path = NULL;
145 struct buffer_head *tmp;
153 if (root->ref_cows == 0) {
156 path = btrfs_alloc_path();
160 level = btrfs_header_level(btrfs_buffer_header(root->node));
165 if (root->defrag_progress.objectid == 0) {
167 ret = btrfs_cow_block(trans, root, root->node, NULL, 0, &tmp);
169 ret = btrfs_realloc_node(trans, root, root->node, cache_only);
171 path->nodes[level] = root->node;
172 path->slots[level] = 0;
174 level = root->defrag_level;
175 path->lowest_level = level;
176 wret = btrfs_search_slot(trans, root, &root->defrag_progress,
183 while(level > 0 && !path->nodes[level])
185 if (!path->nodes[level]) {
192 wret = defrag_walk_down(trans, root, path, &level, cache_only);
198 wret = defrag_walk_up(trans, root, path, &level, cache_only);
203 if (num_runs++ > 8) {
208 for (i = 0; i <= orig_level; i++) {
209 if (path->nodes[i]) {
210 btrfs_block_release(root, path->nodes[i]);
216 btrfs_free_path(path);
217 if (ret != -EAGAIN) {
218 memset(&root->defrag_progress, 0,
219 sizeof(root->defrag_progress));