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-rw-r--r--fs/btrfs/inode-item.c206
1 files changed, 206 insertions, 0 deletions
diff --git a/fs/btrfs/inode-item.c b/fs/btrfs/inode-item.c
new file mode 100644
index 000000000000..3d46fa1f29a4
--- /dev/null
+++ b/fs/btrfs/inode-item.c
@@ -0,0 +1,206 @@
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
23static 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
52int 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 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
77 if (ret > 0) {
78 ret = -ENOENT;
79 goto out;
80 } else if (ret < 0) {
81 goto out;
82 }
83 if (!find_name_in_backref(path, name, name_len, &ref)) {
84 ret = -ENOENT;
85 goto out;
86 }
87 leaf = path->nodes[0];
88 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
89
90 if (index)
91 *index = btrfs_inode_ref_index(leaf, ref);
92
93 if (del_len == item_size) {
94 ret = btrfs_del_item(trans, root, path);
95 goto out;
96 }
97 ptr = (unsigned long)ref;
98 sub_item_len = name_len + sizeof(*ref);
99 item_start = btrfs_item_ptr_offset(leaf, path->slots[0]);
100 memmove_extent_buffer(leaf, ptr, ptr + sub_item_len,
101 item_size - (ptr + sub_item_len - item_start));
102 ret = btrfs_truncate_item(trans, root, path,
103 item_size - sub_item_len, 1);
104 BUG_ON(ret);
105out:
106 btrfs_free_path(path);
107 return ret;
108}
109
110int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans,
111 struct btrfs_root *root,
112 const char *name, int name_len,
113 u64 inode_objectid, u64 ref_objectid, u64 index)
114{
115 struct btrfs_path *path;
116 struct btrfs_key key;
117 struct btrfs_inode_ref *ref;
118 unsigned long ptr;
119 int ret;
120 int ins_len = name_len + sizeof(*ref);
121
122 key.objectid = inode_objectid;
123 key.offset = ref_objectid;
124 btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY);
125
126 path = btrfs_alloc_path();
127 if (!path)
128 return -ENOMEM;
129
130 ret = btrfs_insert_empty_item(trans, root, path, &key,
131 ins_len);
132 if (ret == -EEXIST) {
133 u32 old_size;
134
135 if (find_name_in_backref(path, name, name_len, &ref))
136 goto out;
137
138 old_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
139 ret = btrfs_extend_item(trans, root, path, ins_len);
140 BUG_ON(ret);
141 ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
142 struct btrfs_inode_ref);
143 ref = (struct btrfs_inode_ref *)((unsigned long)ref + old_size);
144 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
145 btrfs_set_inode_ref_index(path->nodes[0], ref, index);
146 ptr = (unsigned long)(ref + 1);
147 ret = 0;
148 } else if (ret < 0) {
149 goto out;
150 } else {
151 ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
152 struct btrfs_inode_ref);
153 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
154 btrfs_set_inode_ref_index(path->nodes[0], ref, index);
155 ptr = (unsigned long)(ref + 1);
156 }
157 write_extent_buffer(path->nodes[0], name, ptr, name_len);
158 btrfs_mark_buffer_dirty(path->nodes[0]);
159
160out:
161 btrfs_free_path(path);
162 return ret;
163}
164
165int btrfs_insert_empty_inode(struct btrfs_trans_handle *trans,
166 struct btrfs_root *root,
167 struct btrfs_path *path, u64 objectid)
168{
169 struct btrfs_key key;
170 int ret;
171 key.objectid = objectid;
172 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
173 key.offset = 0;
174
175 ret = btrfs_insert_empty_item(trans, root, path, &key,
176 sizeof(struct btrfs_inode_item));
177 if (ret == 0 && objectid > root->highest_inode)
178 root->highest_inode = objectid;
179 return ret;
180}
181
182int btrfs_lookup_inode(struct btrfs_trans_handle *trans, struct btrfs_root
183 *root, struct btrfs_path *path,
184 struct btrfs_key *location, int mod)
185{
186 int ins_len = mod < 0 ? -1 : 0;
187 int cow = mod != 0;
188 int ret;
189 int slot;
190 struct extent_buffer *leaf;
191 struct btrfs_key found_key;
192
193 ret = btrfs_search_slot(trans, root, location, path, ins_len, cow);
194 if (ret > 0 && btrfs_key_type(location) == BTRFS_ROOT_ITEM_KEY &&
195 location->offset == (u64)-1 && path->slots[0] != 0) {
196 slot = path->slots[0] - 1;
197 leaf = path->nodes[0];
198 btrfs_item_key_to_cpu(leaf, &found_key, slot);
199 if (found_key.objectid == location->objectid &&
200 btrfs_key_type(&found_key) == btrfs_key_type(location)) {
201 path->slots[0]--;
202 return 0;
203 }
204 }
205 return ret;
206}
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-26 15:04:10 -0500