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 "ctree.h"
20 #include "disk-io.h"
21 #include "transaction.h"
22
23 static int find_name_in_backref(struct btrfs_path *path, const char *name,
24 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
52 int btrfs_del_inode_ref(struct btrfs_trans_handle *trans,
53 struct btrfs_root *root,
54 const char *name, int name_len,
55 u64 inode_objectid, u64 ref_objectid, u64 *index)
56 {
57 struct btrfs_path *path;
58 struct btrfs_key key;
59 struct btrfs_inode_ref *ref;
60 struct extent_buffer *leaf;
61 unsigned long ptr;
62 unsigned long item_start;
63 u32 item_size;
64 u32 sub_item_len;
65 int ret;
66 int del_len = name_len + sizeof(*ref);
67
68 key.objectid = inode_objectid;
69 key.offset = ref_objectid;
70 btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY);
71
72 path = btrfs_alloc_path();
73 if (!path)
74 return -ENOMEM;
75
76 path->leave_spinning = 1;
77
78 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
79 if (ret > 0) {
80 ret = -ENOENT;
81 goto out;
82 } else if (ret < 0) {
83 goto out;
84 }
85 if (!find_name_in_backref(path, name, name_len, &ref)) {
86 ret = -ENOENT;
87 goto out;
88 }
89 leaf = path->nodes[0];
90 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
91
92 if (index)
93 *index = btrfs_inode_ref_index(leaf, ref);
94
95 if (del_len == item_size) {
96 ret = btrfs_del_item(trans, root, path);
97 goto out;
98 }
99 ptr = (unsigned long)ref;
100 sub_item_len = name_len + sizeof(*ref);
101 item_start = btrfs_item_ptr_offset(leaf, path->slots[0]);
102 memmove_extent_buffer(leaf, ptr, ptr + sub_item_len,
103 item_size - (ptr + sub_item_len - item_start));
104 ret = btrfs_truncate_item(trans, root, path,
105 item_size - sub_item_len, 1);
106 BUG_ON(ret);
107 out:
108 btrfs_free_path(path);
109 return ret;
110 }
111
112 int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans,
113 struct btrfs_root *root,
114 const char *name, int name_len,
115 u64 inode_objectid, u64 ref_objectid, u64 index)
116 {
117 struct btrfs_path *path;
118 struct btrfs_key key;
119 struct btrfs_inode_ref *ref;
120 unsigned long ptr;
121 int ret;
122 int ins_len = name_len + sizeof(*ref);
123
124 key.objectid = inode_objectid;
125 key.offset = ref_objectid;
126 btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY);
127
128 path = btrfs_alloc_path();
129 if (!path)
130 return -ENOMEM;
131
132 path->leave_spinning = 1;
133 ret = btrfs_insert_empty_item(trans, root, path, &key,
134 ins_len);
135 if (ret == -EEXIST) {
136 u32 old_size;
137
138 if (find_name_in_backref(path, name, name_len, &ref))
139 goto out;
140
141 old_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
142 ret = btrfs_extend_item(trans, root, path, ins_len);
143 BUG_ON(ret);
144 ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
145 struct btrfs_inode_ref);
146 ref = (struct btrfs_inode_ref *)((unsigned long)ref + old_size);
147 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
148 btrfs_set_inode_ref_index(path->nodes[0], ref, index);
149 ptr = (unsigned long)(ref + 1);
150 ret = 0;
151 } else if (ret < 0) {
152 goto out;
153 } else {
154 ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
155 struct btrfs_inode_ref);
156 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
157 btrfs_set_inode_ref_index(path->nodes[0], ref, index);
158 ptr = (unsigned long)(ref + 1);
159 }
160 write_extent_buffer(path->nodes[0], name, ptr, name_len);
161 btrfs_mark_buffer_dirty(path->nodes[0]);
162
163 out:
164 btrfs_free_path(path);
165 return ret;
166 }
167
168 int btrfs_insert_empty_inode(struct btrfs_trans_handle *trans,
169 struct btrfs_root *root,
170 struct btrfs_path *path, u64 objectid)
171 {
172 struct btrfs_key key;
173 int ret;
174 key.objectid = objectid;
175 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
176 key.offset = 0;
177
178 ret = btrfs_insert_empty_item(trans, root, path, &key,
179 sizeof(struct btrfs_inode_item));
180 if (ret == 0 && objectid > root->highest_inode)
181 root->highest_inode = objectid;
182 return ret;
183 }
184
185 int btrfs_lookup_inode(struct btrfs_trans_handle *trans, struct btrfs_root
186 *root, struct btrfs_path *path,
187 struct btrfs_key *location, int mod)
188 {
189 int ins_len = mod < 0 ? -1 : 0;
190 int cow = mod != 0;
191 int ret;
192 int slot;
193 struct extent_buffer *leaf;
194 struct btrfs_key found_key;
195
196 ret = btrfs_search_slot(trans, root, location, path, ins_len, cow);
197 if (ret > 0 && btrfs_key_type(location) == BTRFS_ROOT_ITEM_KEY &&
198 location->offset == (u64)-1 && path->slots[0] != 0) {
199 slot = path->slots[0] - 1;
200 leaf = path->nodes[0];
201 btrfs_item_key_to_cpu(leaf, &found_key, slot);
202 if (found_key.objectid == location->objectid &&
203 btrfs_key_type(&found_key) == btrfs_key_type(location)) {
204 path->slots[0]--;
205 return 0;
206 }
207 }
208 return ret;
209 }
210
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