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1 | /* | |
2 | * Copyright (C) STRATO AG 2013. 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 | #include <linux/uuid.h> | |
19 | #include <asm/unaligned.h> | |
20 | #include "ctree.h" | |
21 | #include "transaction.h" | |
22 | #include "disk-io.h" | |
23 | #include "print-tree.h" | |
24 | ||
25 | ||
26 | static void btrfs_uuid_to_key(u8 *uuid, u8 type, struct btrfs_key *key) | |
27 | { | |
28 | key->type = type; | |
29 | key->objectid = get_unaligned_le64(uuid); | |
30 | key->offset = get_unaligned_le64(uuid + sizeof(u64)); | |
31 | } | |
32 | ||
33 | /* return -ENOENT for !found, < 0 for errors, or 0 if an item was found */ | |
34 | static int btrfs_uuid_tree_lookup(struct btrfs_root *uuid_root, u8 *uuid, | |
35 | u8 type, u64 subid) | |
36 | { | |
37 | int ret; | |
38 | struct btrfs_path *path = NULL; | |
39 | struct extent_buffer *eb; | |
40 | int slot; | |
41 | u32 item_size; | |
42 | unsigned long offset; | |
43 | struct btrfs_key key; | |
44 | ||
45 | if (WARN_ON_ONCE(!uuid_root)) { | |
46 | ret = -ENOENT; | |
47 | goto out; | |
48 | } | |
49 | ||
50 | path = btrfs_alloc_path(); | |
51 | if (!path) { | |
52 | ret = -ENOMEM; | |
53 | goto out; | |
54 | } | |
55 | ||
56 | btrfs_uuid_to_key(uuid, type, &key); | |
57 | ret = btrfs_search_slot(NULL, uuid_root, &key, path, 0, 0); | |
58 | if (ret < 0) { | |
59 | goto out; | |
60 | } else if (ret > 0) { | |
61 | ret = -ENOENT; | |
62 | goto out; | |
63 | } | |
64 | ||
65 | eb = path->nodes[0]; | |
66 | slot = path->slots[0]; | |
67 | item_size = btrfs_item_size_nr(eb, slot); | |
68 | offset = btrfs_item_ptr_offset(eb, slot); | |
69 | ret = -ENOENT; | |
70 | ||
71 | if (!IS_ALIGNED(item_size, sizeof(u64))) { | |
72 | pr_warn("btrfs: uuid item with illegal size %lu!\n", | |
73 | (unsigned long)item_size); | |
74 | goto out; | |
75 | } | |
76 | while (item_size) { | |
77 | __le64 data; | |
78 | ||
79 | read_extent_buffer(eb, &data, offset, sizeof(data)); | |
80 | if (le64_to_cpu(data) == subid) { | |
81 | ret = 0; | |
82 | break; | |
83 | } | |
84 | offset += sizeof(data); | |
85 | item_size -= sizeof(data); | |
86 | } | |
87 | ||
88 | out: | |
89 | btrfs_free_path(path); | |
90 | return ret; | |
91 | } | |
92 | ||
93 | int btrfs_uuid_tree_add(struct btrfs_trans_handle *trans, | |
94 | struct btrfs_root *uuid_root, u8 *uuid, u8 type, | |
95 | u64 subid_cpu) | |
96 | { | |
97 | int ret; | |
98 | struct btrfs_path *path = NULL; | |
99 | struct btrfs_key key; | |
100 | struct extent_buffer *eb; | |
101 | int slot; | |
102 | unsigned long offset; | |
103 | __le64 subid_le; | |
104 | ||
105 | ret = btrfs_uuid_tree_lookup(uuid_root, uuid, type, subid_cpu); | |
106 | if (ret != -ENOENT) | |
107 | return ret; | |
108 | ||
109 | if (WARN_ON_ONCE(!uuid_root)) { | |
110 | ret = -EINVAL; | |
111 | goto out; | |
112 | } | |
113 | ||
114 | btrfs_uuid_to_key(uuid, type, &key); | |
115 | ||
116 | path = btrfs_alloc_path(); | |
117 | if (!path) { | |
118 | ret = -ENOMEM; | |
119 | goto out; | |
120 | } | |
121 | ||
122 | ret = btrfs_insert_empty_item(trans, uuid_root, path, &key, | |
123 | sizeof(subid_le)); | |
124 | if (ret >= 0) { | |
125 | /* Add an item for the type for the first time */ | |
126 | eb = path->nodes[0]; | |
127 | slot = path->slots[0]; | |
128 | offset = btrfs_item_ptr_offset(eb, slot); | |
129 | } else if (ret == -EEXIST) { | |
130 | /* | |
131 | * An item with that type already exists. | |
132 | * Extend the item and store the new subid at the end. | |
133 | */ | |
134 | btrfs_extend_item(uuid_root, path, sizeof(subid_le)); | |
135 | eb = path->nodes[0]; | |
136 | slot = path->slots[0]; | |
137 | offset = btrfs_item_ptr_offset(eb, slot); | |
138 | offset += btrfs_item_size_nr(eb, slot) - sizeof(subid_le); | |
139 | } else if (ret < 0) { | |
140 | pr_warn("btrfs: insert uuid item failed %d (0x%016llx, 0x%016llx) type %u!\n", | |
141 | ret, (unsigned long long)key.objectid, | |
142 | (unsigned long long)key.offset, type); | |
143 | goto out; | |
144 | } | |
145 | ||
146 | ret = 0; | |
147 | subid_le = cpu_to_le64(subid_cpu); | |
148 | write_extent_buffer(eb, &subid_le, offset, sizeof(subid_le)); | |
149 | btrfs_mark_buffer_dirty(eb); | |
150 | ||
151 | out: | |
152 | btrfs_free_path(path); | |
153 | return ret; | |
154 | } | |
155 | ||
156 | int btrfs_uuid_tree_rem(struct btrfs_trans_handle *trans, | |
157 | struct btrfs_root *uuid_root, u8 *uuid, u8 type, | |
158 | u64 subid) | |
159 | { | |
160 | int ret; | |
161 | struct btrfs_path *path = NULL; | |
162 | struct btrfs_key key; | |
163 | struct extent_buffer *eb; | |
164 | int slot; | |
165 | unsigned long offset; | |
166 | u32 item_size; | |
167 | unsigned long move_dst; | |
168 | unsigned long move_src; | |
169 | unsigned long move_len; | |
170 | ||
171 | if (WARN_ON_ONCE(!uuid_root)) { | |
172 | ret = -EINVAL; | |
173 | goto out; | |
174 | } | |
175 | ||
176 | btrfs_uuid_to_key(uuid, type, &key); | |
177 | ||
178 | path = btrfs_alloc_path(); | |
179 | if (!path) { | |
180 | ret = -ENOMEM; | |
181 | goto out; | |
182 | } | |
183 | ||
184 | ret = btrfs_search_slot(trans, uuid_root, &key, path, -1, 1); | |
185 | if (ret < 0) { | |
186 | pr_warn("btrfs: error %d while searching for uuid item!\n", | |
187 | ret); | |
188 | goto out; | |
189 | } | |
190 | if (ret > 0) { | |
191 | ret = -ENOENT; | |
192 | goto out; | |
193 | } | |
194 | ||
195 | eb = path->nodes[0]; | |
196 | slot = path->slots[0]; | |
197 | offset = btrfs_item_ptr_offset(eb, slot); | |
198 | item_size = btrfs_item_size_nr(eb, slot); | |
199 | if (!IS_ALIGNED(item_size, sizeof(u64))) { | |
200 | pr_warn("btrfs: uuid item with illegal size %lu!\n", | |
201 | (unsigned long)item_size); | |
202 | ret = -ENOENT; | |
203 | goto out; | |
204 | } | |
205 | while (item_size) { | |
206 | __le64 read_subid; | |
207 | ||
208 | read_extent_buffer(eb, &read_subid, offset, sizeof(read_subid)); | |
209 | if (le64_to_cpu(read_subid) == subid) | |
210 | break; | |
211 | offset += sizeof(read_subid); | |
212 | item_size -= sizeof(read_subid); | |
213 | } | |
214 | ||
215 | if (!item_size) { | |
216 | ret = -ENOENT; | |
217 | goto out; | |
218 | } | |
219 | ||
220 | item_size = btrfs_item_size_nr(eb, slot); | |
221 | if (item_size == sizeof(subid)) { | |
222 | ret = btrfs_del_item(trans, uuid_root, path); | |
223 | goto out; | |
224 | } | |
225 | ||
226 | move_dst = offset; | |
227 | move_src = offset + sizeof(subid); | |
228 | move_len = item_size - (move_src - btrfs_item_ptr_offset(eb, slot)); | |
229 | memmove_extent_buffer(eb, move_dst, move_src, move_len); | |
230 | btrfs_truncate_item(uuid_root, path, item_size - sizeof(subid), 1); | |
231 | ||
232 | out: | |
233 | btrfs_free_path(path); | |
234 | return ret; | |
235 | } |