blob: 64f1150bb48d1fb1cd5b7c7d29742b3f9afff7cd [file] [log] [blame]
Chris Mason6cbd5572007-06-12 09:07:21 -04001/*
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
Chris Mason1e1d2702007-03-15 19:03:33 -040019#include "ctree.h"
20#include "disk-io.h"
Chris Masone089f052007-03-16 16:20:31 -040021#include "transaction.h"
Chris Mason1e1d2702007-03-15 19:03:33 -040022
Christoph Hellwigb2950862008-12-02 09:54:17 -050023static int find_name_in_backref(struct btrfs_path *path, const char *name,
Chris Mason39544012007-12-12 14:38:19 -050024 int name_len, struct btrfs_inode_ref **ref_ret)
25{
26 struct extent_buffer *leaf;
27 struct btrfs_inode_ref *ref;
28 unsigned long ptr;
29 unsigned long name_ptr;
30 u32 item_size;
31 u32 cur_offset = 0;
32 int len;
33
34 leaf = path->nodes[0];
35 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
36 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
37 while (cur_offset < item_size) {
38 ref = (struct btrfs_inode_ref *)(ptr + cur_offset);
39 len = btrfs_inode_ref_name_len(leaf, ref);
40 name_ptr = (unsigned long)(ref + 1);
41 cur_offset += len + sizeof(*ref);
42 if (len != name_len)
43 continue;
44 if (memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0) {
45 *ref_ret = ref;
46 return 1;
47 }
48 }
49 return 0;
50}
51
Yan, Zhenga22285a2010-05-16 10:48:46 -040052struct btrfs_inode_ref *
53btrfs_lookup_inode_ref(struct btrfs_trans_handle *trans,
54 struct btrfs_root *root,
55 struct btrfs_path *path,
56 const char *name, int name_len,
57 u64 inode_objectid, u64 ref_objectid, int mod)
58{
59 struct btrfs_key key;
60 struct btrfs_inode_ref *ref;
61 int ins_len = mod < 0 ? -1 : 0;
62 int cow = mod != 0;
63 int ret;
64
65 key.objectid = inode_objectid;
66 key.type = BTRFS_INODE_REF_KEY;
67 key.offset = ref_objectid;
68
69 ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
70 if (ret < 0)
71 return ERR_PTR(ret);
72 if (ret > 0)
73 return NULL;
74 if (!find_name_in_backref(path, name, name_len, &ref))
75 return NULL;
76 return ref;
77}
78
Chris Mason39544012007-12-12 14:38:19 -050079int btrfs_del_inode_ref(struct btrfs_trans_handle *trans,
80 struct btrfs_root *root,
81 const char *name, int name_len,
Josef Bacikaec74772008-07-24 12:12:38 -040082 u64 inode_objectid, u64 ref_objectid, u64 *index)
Chris Mason39544012007-12-12 14:38:19 -050083{
84 struct btrfs_path *path;
85 struct btrfs_key key;
86 struct btrfs_inode_ref *ref;
87 struct extent_buffer *leaf;
88 unsigned long ptr;
89 unsigned long item_start;
90 u32 item_size;
91 u32 sub_item_len;
92 int ret;
93 int del_len = name_len + sizeof(*ref);
94
95 key.objectid = inode_objectid;
96 key.offset = ref_objectid;
97 btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY);
98
99 path = btrfs_alloc_path();
100 if (!path)
101 return -ENOMEM;
102
Chris Masonb9473432009-03-13 11:00:37 -0400103 path->leave_spinning = 1;
104
Chris Mason39544012007-12-12 14:38:19 -0500105 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
106 if (ret > 0) {
107 ret = -ENOENT;
108 goto out;
109 } else if (ret < 0) {
110 goto out;
111 }
112 if (!find_name_in_backref(path, name, name_len, &ref)) {
113 ret = -ENOENT;
114 goto out;
115 }
116 leaf = path->nodes[0];
117 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
Josef Bacikaec74772008-07-24 12:12:38 -0400118
119 if (index)
120 *index = btrfs_inode_ref_index(leaf, ref);
121
Chris Mason39544012007-12-12 14:38:19 -0500122 if (del_len == item_size) {
123 ret = btrfs_del_item(trans, root, path);
124 goto out;
125 }
126 ptr = (unsigned long)ref;
127 sub_item_len = name_len + sizeof(*ref);
128 item_start = btrfs_item_ptr_offset(leaf, path->slots[0]);
129 memmove_extent_buffer(leaf, ptr, ptr + sub_item_len,
130 item_size - (ptr + sub_item_len - item_start));
131 ret = btrfs_truncate_item(trans, root, path,
132 item_size - sub_item_len, 1);
133 BUG_ON(ret);
134out:
135 btrfs_free_path(path);
136 return ret;
137}
138
139int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans,
140 struct btrfs_root *root,
141 const char *name, int name_len,
Josef Bacikaec74772008-07-24 12:12:38 -0400142 u64 inode_objectid, u64 ref_objectid, u64 index)
Chris Mason39544012007-12-12 14:38:19 -0500143{
144 struct btrfs_path *path;
145 struct btrfs_key key;
146 struct btrfs_inode_ref *ref;
147 unsigned long ptr;
148 int ret;
149 int ins_len = name_len + sizeof(*ref);
150
151 key.objectid = inode_objectid;
152 key.offset = ref_objectid;
153 btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY);
154
155 path = btrfs_alloc_path();
156 if (!path)
157 return -ENOMEM;
158
Chris Masonb9473432009-03-13 11:00:37 -0400159 path->leave_spinning = 1;
Chris Mason39544012007-12-12 14:38:19 -0500160 ret = btrfs_insert_empty_item(trans, root, path, &key,
161 ins_len);
162 if (ret == -EEXIST) {
163 u32 old_size;
164
165 if (find_name_in_backref(path, name, name_len, &ref))
166 goto out;
167
168 old_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
169 ret = btrfs_extend_item(trans, root, path, ins_len);
170 BUG_ON(ret);
171 ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
172 struct btrfs_inode_ref);
173 ref = (struct btrfs_inode_ref *)((unsigned long)ref + old_size);
174 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
Josef Bacikaec74772008-07-24 12:12:38 -0400175 btrfs_set_inode_ref_index(path->nodes[0], ref, index);
Chris Mason39544012007-12-12 14:38:19 -0500176 ptr = (unsigned long)(ref + 1);
177 ret = 0;
178 } else if (ret < 0) {
Yan, Zhenga5719522009-09-24 09:17:31 -0400179 if (ret == -EOVERFLOW)
180 ret = -EMLINK;
Chris Mason39544012007-12-12 14:38:19 -0500181 goto out;
182 } else {
183 ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
184 struct btrfs_inode_ref);
185 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
Josef Bacikaec74772008-07-24 12:12:38 -0400186 btrfs_set_inode_ref_index(path->nodes[0], ref, index);
Chris Mason39544012007-12-12 14:38:19 -0500187 ptr = (unsigned long)(ref + 1);
188 }
189 write_extent_buffer(path->nodes[0], name, ptr, name_len);
190 btrfs_mark_buffer_dirty(path->nodes[0]);
191
192out:
193 btrfs_free_path(path);
194 return ret;
195}
196
Chris Mason5f39d392007-10-15 16:14:19 -0400197int btrfs_insert_empty_inode(struct btrfs_trans_handle *trans,
198 struct btrfs_root *root,
199 struct btrfs_path *path, u64 objectid)
Chris Mason1e1d2702007-03-15 19:03:33 -0400200{
Chris Mason1e1d2702007-03-15 19:03:33 -0400201 struct btrfs_key key;
202 int ret;
203 key.objectid = objectid;
Chris Mason1e1d2702007-03-15 19:03:33 -0400204 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
205 key.offset = 0;
206
Chris Mason5f39d392007-10-15 16:14:19 -0400207 ret = btrfs_insert_empty_item(trans, root, path, &key,
208 sizeof(struct btrfs_inode_item));
Chris Mason1e1d2702007-03-15 19:03:33 -0400209 return ret;
210}
211
Chris Masone089f052007-03-16 16:20:31 -0400212int btrfs_lookup_inode(struct btrfs_trans_handle *trans, struct btrfs_root
Chris Masond6e4a422007-04-06 15:37:36 -0400213 *root, struct btrfs_path *path,
214 struct btrfs_key *location, int mod)
Chris Mason1e1d2702007-03-15 19:03:33 -0400215{
Chris Mason1e1d2702007-03-15 19:03:33 -0400216 int ins_len = mod < 0 ? -1 : 0;
217 int cow = mod != 0;
Chris Masond6e4a422007-04-06 15:37:36 -0400218 int ret;
219 int slot;
Chris Mason5f39d392007-10-15 16:14:19 -0400220 struct extent_buffer *leaf;
Chris Masond6e4a422007-04-06 15:37:36 -0400221 struct btrfs_key found_key;
Chris Mason1e1d2702007-03-15 19:03:33 -0400222
Chris Masond6e4a422007-04-06 15:37:36 -0400223 ret = btrfs_search_slot(trans, root, location, path, ins_len, cow);
224 if (ret > 0 && btrfs_key_type(location) == BTRFS_ROOT_ITEM_KEY &&
225 location->offset == (u64)-1 && path->slots[0] != 0) {
226 slot = path->slots[0] - 1;
Chris Mason5f39d392007-10-15 16:14:19 -0400227 leaf = path->nodes[0];
228 btrfs_item_key_to_cpu(leaf, &found_key, slot);
Chris Masond6e4a422007-04-06 15:37:36 -0400229 if (found_key.objectid == location->objectid &&
230 btrfs_key_type(&found_key) == btrfs_key_type(location)) {
231 path->slots[0]--;
232 return 0;
233 }
234 }
235 return ret;
Chris Mason1e1d2702007-03-15 19:03:33 -0400236}