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authorChris Mason <chris.mason@oracle.com>2008-09-25 15:32:36 -0400
committerChris Mason <chris.mason@oracle.com>2008-09-25 15:33:18 -0400
commitaef8755711a28bb0ecde7780ae6613fcb62cf6f7 (patch)
tree407909172c536be3336e8f3c9ec39a3003c29c3f /fs/btrfs/tree-defrag.c
parent72d31053f62c4bc464c2783974926969614a8649 (diff)
parent34353029534a08e41cfb8be647d734b9ce9ebff8 (diff)
Merge Btrfs into fs/btrfs
Diffstat (limited to 'fs/btrfs/tree-defrag.c')
-rw-r--r--fs/btrfs/tree-defrag.c145
1 files changed, 145 insertions, 0 deletions
diff --git a/fs/btrfs/tree-defrag.c b/fs/btrfs/tree-defrag.c
new file mode 100644
index 000000000000..b3bb5bbad76e
--- /dev/null
+++ b/fs/btrfs/tree-defrag.c
@@ -0,0 +1,145 @@
1/*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
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.
7 *
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.
12 *
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.
17 */
18
19#include <linux/sched.h>
20#include "ctree.h"
21#include "disk-io.h"
22#include "print-tree.h"
23#include "transaction.h"
24#include "locking.h"
25
26int btrfs_defrag_leaves(struct btrfs_trans_handle *trans,
27 struct btrfs_root *root, int cache_only)
28{
29 struct btrfs_path *path = NULL;
30 struct btrfs_key key;
31 int ret = 0;
32 int wret;
33 int level;
34 int orig_level;
35 int is_extent = 0;
36 int next_key_ret = 0;
37 u64 last_ret = 0;
38 u64 min_trans = 0;
39
40 if (cache_only)
41 goto out;
42
43 if (root->fs_info->extent_root == root) {
44 /*
45 * there's recursion here right now in the tree locking,
46 * we can't defrag the extent root without deadlock
47 */
48 goto out;
49 }
50
51 if (root->ref_cows == 0 && !is_extent)
52 goto out;
53
54 if (btrfs_test_opt(root, SSD))
55 goto out;
56
57 path = btrfs_alloc_path();
58 if (!path)
59 return -ENOMEM;
60
61 level = btrfs_header_level(root->node);
62 orig_level = level;
63
64 if (level == 0) {
65 goto out;
66 }
67 if (root->defrag_progress.objectid == 0) {
68 struct extent_buffer *root_node;
69 u32 nritems;
70
71 root_node = btrfs_lock_root_node(root);
72 nritems = btrfs_header_nritems(root_node);
73 root->defrag_max.objectid = 0;
74 /* from above we know this is not a leaf */
75 btrfs_node_key_to_cpu(root_node, &root->defrag_max,
76 nritems - 1);
77 btrfs_tree_unlock(root_node);
78 free_extent_buffer(root_node);
79 memset(&key, 0, sizeof(key));
80 } else {
81 memcpy(&key, &root->defrag_progress, sizeof(key));
82 }
83
84 path->keep_locks = 1;
85 if (cache_only)
86 min_trans = root->defrag_trans_start;
87
88 ret = btrfs_search_forward(root, &key, NULL, path,
89 cache_only, min_trans);
90 if (ret < 0)
91 goto out;
92 if (ret > 0) {
93 ret = 0;
94 goto out;
95 }
96 btrfs_release_path(root, path);
97 wret = btrfs_search_slot(trans, root, &key, path, 0, 1);
98
99 if (wret < 0) {
100 ret = wret;
101 goto out;
102 }
103 if (!path->nodes[1]) {
104 ret = 0;
105 goto out;
106 }
107 path->slots[1] = btrfs_header_nritems(path->nodes[1]);
108 next_key_ret = btrfs_find_next_key(root, path, &key, 1, cache_only,
109 min_trans);
110 ret = btrfs_realloc_node(trans, root,
111 path->nodes[1], 0,
112 cache_only, &last_ret,
113 &root->defrag_progress);
114 WARN_ON(ret && ret != -EAGAIN);
115 if (next_key_ret == 0) {
116 memcpy(&root->defrag_progress, &key, sizeof(key));
117 ret = -EAGAIN;
118 }
119
120 btrfs_release_path(root, path);
121 if (is_extent)
122 btrfs_extent_post_op(trans, root);
123out:
124 if (is_extent)
125 mutex_unlock(&root->fs_info->alloc_mutex);
126
127 if (path)
128 btrfs_free_path(path);
129 if (ret == -EAGAIN) {
130 if (root->defrag_max.objectid > root->defrag_progress.objectid)
131 goto done;
132 if (root->defrag_max.type > root->defrag_progress.type)
133 goto done;
134 if (root->defrag_max.offset > root->defrag_progress.offset)
135 goto done;
136 ret = 0;
137 }
138done:
139 if (ret != -EAGAIN) {
140 memset(&root->defrag_progress, 0,
141 sizeof(root->defrag_progress));
142 root->defrag_trans_start = trans->transid;
143 }
144 return ret;
145}