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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 | ||
25 | static void reada_defrag(struct btrfs_root *root, | |
26 | struct btrfs_node *node) | |
27 | { | |
28 | int i; | |
29 | u32 nritems; | |
30 | u64 blocknr; | |
31 | int ret; | |
32 | ||
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); | |
37 | if (ret) | |
38 | break; | |
39 | } | |
40 | } | |
41 | ||
42 | static int defrag_walk_down(struct btrfs_trans_handle *trans, | |
43 | struct btrfs_root *root, | |
44 | struct btrfs_path *path, int *level, | |
45 | int cache_only) | |
46 | { | |
47 | struct buffer_head *next; | |
48 | struct buffer_head *cur; | |
49 | u64 blocknr; | |
50 | int ret = 0; | |
51 | ||
52 | WARN_ON(*level < 0); | |
53 | WARN_ON(*level >= BTRFS_MAX_LEVEL); | |
54 | ||
55 | while(*level > 0) { | |
56 | WARN_ON(*level < 0); | |
57 | WARN_ON(*level >= BTRFS_MAX_LEVEL); | |
58 | cur = path->nodes[*level]; | |
59 | ||
60 | if (!cache_only && *level > 1 && path->slots[*level] == 0) | |
61 | reada_defrag(root, btrfs_buffer_node(cur)); | |
62 | ||
63 | if (btrfs_header_level(btrfs_buffer_header(cur)) != *level) | |
64 | WARN_ON(1); | |
65 | ||
66 | if (path->slots[*level] >= | |
67 | btrfs_header_nritems(btrfs_buffer_header(cur))) | |
68 | break; | |
69 | ||
70 | if (*level == 1) { | |
71 | ret = btrfs_realloc_node(trans, root, | |
72 | path->nodes[*level], | |
73 | cache_only); | |
74 | break; | |
75 | } | |
76 | blocknr = btrfs_node_blockptr(btrfs_buffer_node(cur), | |
77 | path->slots[*level]); | |
78 | ||
79 | if (cache_only) { | |
80 | next = btrfs_find_tree_block(root, blocknr); | |
81 | if (!next || !buffer_uptodate(next) || | |
82 | buffer_locked(next)) { | |
83 | brelse(next); | |
84 | path->slots[*level]++; | |
85 | continue; | |
86 | } | |
87 | } else { | |
88 | next = read_tree_block(root, blocknr); | |
89 | } | |
90 | ret = btrfs_cow_block(trans, root, next, path->nodes[*level], | |
91 | path->slots[*level], &next); | |
92 | BUG_ON(ret); | |
93 | ret = btrfs_realloc_node(trans, root, next, cache_only); | |
94 | BUG_ON(ret); | |
95 | WARN_ON(*level <= 0); | |
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; | |
101 | } | |
102 | WARN_ON(*level < 0); | |
103 | WARN_ON(*level >= BTRFS_MAX_LEVEL); | |
104 | btrfs_block_release(root, path->nodes[*level]); | |
105 | path->nodes[*level] = NULL; | |
106 | *level += 1; | |
107 | WARN_ON(ret); | |
108 | return 0; | |
109 | } | |
110 | ||
111 | static int defrag_walk_up(struct btrfs_trans_handle *trans, | |
112 | struct btrfs_root *root, | |
113 | struct btrfs_path *path, int *level, | |
114 | int cache_only) | |
115 | { | |
116 | int i; | |
117 | int slot; | |
118 | struct btrfs_node *node; | |
119 | ||
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) { | |
124 | path->slots[i]++; | |
125 | *level = i; | |
126 | node = btrfs_buffer_node(path->nodes[i]); | |
127 | WARN_ON(i == 0); | |
128 | btrfs_disk_key_to_cpu(&root->defrag_progress, | |
129 | &node->ptrs[path->slots[i]].key); | |
130 | root->defrag_level = i; | |
131 | return 0; | |
132 | } else { | |
133 | btrfs_block_release(root, path->nodes[*level]); | |
134 | path->nodes[*level] = NULL; | |
135 | *level = i + 1; | |
136 | } | |
137 | } | |
138 | return 1; | |
139 | } | |
140 | ||
141 | int btrfs_defrag_leaves(struct btrfs_trans_handle *trans, | |
142 | struct btrfs_root *root, int cache_only) | |
143 | { | |
144 | struct btrfs_path *path = NULL; | |
145 | struct buffer_head *tmp; | |
146 | int ret = 0; | |
147 | int wret; | |
148 | int level; | |
149 | int orig_level; | |
150 | int i; | |
6702ed49 CM |
151 | |
152 | if (root->ref_cows == 0) { | |
153 | goto out; | |
154 | } | |
155 | path = btrfs_alloc_path(); | |
156 | if (!path) | |
157 | return -ENOMEM; | |
158 | ||
159 | level = btrfs_header_level(btrfs_buffer_header(root->node)); | |
160 | orig_level = level; | |
161 | if (level == 0) { | |
162 | goto out; | |
163 | } | |
164 | if (root->defrag_progress.objectid == 0) { | |
165 | get_bh(root->node); | |
166 | ret = btrfs_cow_block(trans, root, root->node, NULL, 0, &tmp); | |
167 | BUG_ON(ret); | |
168 | ret = btrfs_realloc_node(trans, root, root->node, cache_only); | |
169 | BUG_ON(ret); | |
170 | path->nodes[level] = root->node; | |
171 | path->slots[level] = 0; | |
172 | } else { | |
173 | level = root->defrag_level; | |
174 | path->lowest_level = level; | |
175 | wret = btrfs_search_slot(trans, root, &root->defrag_progress, | |
176 | path, 0, 1); | |
177 | ||
178 | if (wret < 0) { | |
179 | ret = wret; | |
180 | goto out; | |
181 | } | |
182 | while(level > 0 && !path->nodes[level]) | |
183 | level--; | |
184 | if (!path->nodes[level]) { | |
185 | ret = 0; | |
186 | goto out; | |
187 | } | |
188 | } | |
189 | ||
190 | while(1) { | |
191 | wret = defrag_walk_down(trans, root, path, &level, cache_only); | |
192 | if (wret > 0) | |
193 | break; | |
194 | if (wret < 0) | |
195 | ret = wret; | |
196 | ||
197 | wret = defrag_walk_up(trans, root, path, &level, cache_only); | |
198 | if (wret > 0) | |
199 | break; | |
200 | if (wret < 0) | |
201 | ret = wret; | |
409eb95d CM |
202 | ret = -EAGAIN; |
203 | break; | |
6702ed49 CM |
204 | } |
205 | for (i = 0; i <= orig_level; i++) { | |
206 | if (path->nodes[i]) { | |
207 | btrfs_block_release(root, path->nodes[i]); | |
208 | path->nodes[i] = 0; | |
209 | } | |
210 | } | |
211 | out: | |
212 | if (path) | |
213 | btrfs_free_path(path); | |
214 | if (ret != -EAGAIN) { | |
215 | memset(&root->defrag_progress, 0, | |
216 | sizeof(root->defrag_progress)); | |
217 | } | |
218 | return ret; | |
219 | } |