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 extent_buffer *node)
35 blocksize = btrfs_level_size(root, btrfs_header_level(node) - 1);
36 nritems = btrfs_header_nritems(node);
37 for (i = 0; i < nritems; i++) {
38 bytenr = btrfs_node_blockptr(node, i);
39 gen = btrfs_node_ptr_generation(node, i);
40 ret = readahead_tree_block(root, bytenr, blocksize, gen);
46 static int defrag_walk_down(struct btrfs_trans_handle *trans,
47 struct btrfs_root *root,
48 struct btrfs_path *path, int *level,
49 int cache_only, u64 *last_ret)
51 struct extent_buffer *next;
52 struct extent_buffer *cur;
59 WARN_ON(*level >= BTRFS_MAX_LEVEL);
61 if (root->fs_info->extent_root == root)
64 if (*level == 1 && cache_only && path->nodes[1] &&
65 !btrfs_buffer_defrag(path->nodes[1])) {
70 WARN_ON(*level >= BTRFS_MAX_LEVEL);
71 cur = path->nodes[*level];
73 if (!cache_only && *level > 1 && path->slots[*level] == 0)
74 reada_defrag(root, cur);
76 if (btrfs_header_level(cur) != *level)
79 if (path->slots[*level] >=
80 btrfs_header_nritems(cur))
84 WARN_ON(btrfs_header_generation(path->nodes[*level]) !=
86 ret = btrfs_realloc_node(trans, root,
90 &root->defrag_progress);
92 btrfs_extent_post_op(trans, root);
96 bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
97 ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
100 next = btrfs_find_tree_block(root, bytenr,
101 btrfs_level_size(root, *level - 1));
102 if (!next || !btrfs_buffer_uptodate(next, ptr_gen) ||
103 !btrfs_buffer_defrag(next)) {
104 free_extent_buffer(next);
105 path->slots[*level]++;
109 next = read_tree_block(root, bytenr,
110 btrfs_level_size(root, *level - 1),
113 ret = btrfs_cow_block(trans, root, next, path->nodes[*level],
114 path->slots[*level], &next);
117 btrfs_extent_post_op(trans, root);
119 WARN_ON(*level <= 0);
120 if (path->nodes[*level-1])
121 free_extent_buffer(path->nodes[*level-1]);
122 path->nodes[*level-1] = next;
123 *level = btrfs_header_level(next);
124 path->slots[*level] = 0;
127 WARN_ON(*level >= BTRFS_MAX_LEVEL);
129 btrfs_clear_buffer_defrag(path->nodes[*level]);
131 free_extent_buffer(path->nodes[*level]);
132 path->nodes[*level] = NULL;
134 WARN_ON(ret && ret != -EAGAIN);
138 static int defrag_walk_up(struct btrfs_trans_handle *trans,
139 struct btrfs_root *root,
140 struct btrfs_path *path, int *level,
145 struct extent_buffer *node;
147 for(i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
148 slot = path->slots[i];
149 if (slot < btrfs_header_nritems(path->nodes[i]) - 1) {
152 node = path->nodes[i];
154 btrfs_node_key_to_cpu(node, &root->defrag_progress,
156 root->defrag_level = i;
159 btrfs_clear_buffer_defrag(path->nodes[*level]);
160 free_extent_buffer(path->nodes[*level]);
161 path->nodes[*level] = NULL;
168 int btrfs_defrag_leaves(struct btrfs_trans_handle *trans,
169 struct btrfs_root *root, int cache_only)
171 struct btrfs_path *path = NULL;
172 struct extent_buffer *tmp;
181 if (root->fs_info->extent_root == root)
184 if (root->ref_cows == 0 && !is_extent)
187 if (btrfs_test_opt(root, SSD))
190 path = btrfs_alloc_path();
194 level = btrfs_header_level(root->node);
200 if (root->defrag_progress.objectid == 0) {
201 extent_buffer_get(root->node);
202 ret = btrfs_cow_block(trans, root, root->node, NULL, 0, &tmp);
204 path->nodes[level] = root->node;
205 path->slots[level] = 0;
207 btrfs_extent_post_op(trans, root);
209 level = root->defrag_level;
210 path->lowest_level = level;
211 wret = btrfs_search_slot(trans, root, &root->defrag_progress,
215 btrfs_extent_post_op(trans, root);
222 while(level > 0 && !path->nodes[level])
225 if (!path->nodes[level]) {
232 wret = defrag_walk_down(trans, root, path, &level, cache_only,
239 wret = defrag_walk_up(trans, root, path, &level, cache_only);
248 for (i = 0; i <= orig_level; i++) {
249 if (path->nodes[i]) {
250 free_extent_buffer(path->nodes[i]);
251 path->nodes[i] = NULL;
256 btrfs_free_path(path);
257 if (ret != -EAGAIN) {
258 memset(&root->defrag_progress, 0,
259 sizeof(root->defrag_progress));