1
2
3
4
5
6#include <linux/uuid.h>
7#include <asm/unaligned.h>
8#include "ctree.h"
9#include "transaction.h"
10#include "disk-io.h"
11#include "print-tree.h"
12
13
14static void btrfs_uuid_to_key(u8 *uuid, u8 type, struct btrfs_key *key)
15{
16 key->type = type;
17 key->objectid = get_unaligned_le64(uuid);
18 key->offset = get_unaligned_le64(uuid + sizeof(u64));
19}
20
21
22static int btrfs_uuid_tree_lookup(struct btrfs_root *uuid_root, u8 *uuid,
23 u8 type, u64 subid)
24{
25 int ret;
26 struct btrfs_path *path = NULL;
27 struct extent_buffer *eb;
28 int slot;
29 u32 item_size;
30 unsigned long offset;
31 struct btrfs_key key;
32
33 if (WARN_ON_ONCE(!uuid_root)) {
34 ret = -ENOENT;
35 goto out;
36 }
37
38 path = btrfs_alloc_path();
39 if (!path) {
40 ret = -ENOMEM;
41 goto out;
42 }
43
44 btrfs_uuid_to_key(uuid, type, &key);
45 ret = btrfs_search_slot(NULL, uuid_root, &key, path, 0, 0);
46 if (ret < 0) {
47 goto out;
48 } else if (ret > 0) {
49 ret = -ENOENT;
50 goto out;
51 }
52
53 eb = path->nodes[0];
54 slot = path->slots[0];
55 item_size = btrfs_item_size_nr(eb, slot);
56 offset = btrfs_item_ptr_offset(eb, slot);
57 ret = -ENOENT;
58
59 if (!IS_ALIGNED(item_size, sizeof(u64))) {
60 btrfs_warn(uuid_root->fs_info,
61 "uuid item with illegal size %lu!",
62 (unsigned long)item_size);
63 goto out;
64 }
65 while (item_size) {
66 __le64 data;
67
68 read_extent_buffer(eb, &data, offset, sizeof(data));
69 if (le64_to_cpu(data) == subid) {
70 ret = 0;
71 break;
72 }
73 offset += sizeof(data);
74 item_size -= sizeof(data);
75 }
76
77out:
78 btrfs_free_path(path);
79 return ret;
80}
81
82int btrfs_uuid_tree_add(struct btrfs_trans_handle *trans, u8 *uuid, u8 type,
83 u64 subid_cpu)
84{
85 struct btrfs_fs_info *fs_info = trans->fs_info;
86 struct btrfs_root *uuid_root = fs_info->uuid_root;
87 int ret;
88 struct btrfs_path *path = NULL;
89 struct btrfs_key key;
90 struct extent_buffer *eb;
91 int slot;
92 unsigned long offset;
93 __le64 subid_le;
94
95 ret = btrfs_uuid_tree_lookup(uuid_root, uuid, type, subid_cpu);
96 if (ret != -ENOENT)
97 return ret;
98
99 if (WARN_ON_ONCE(!uuid_root)) {
100 ret = -EINVAL;
101 goto out;
102 }
103
104 btrfs_uuid_to_key(uuid, type, &key);
105
106 path = btrfs_alloc_path();
107 if (!path) {
108 ret = -ENOMEM;
109 goto out;
110 }
111
112 ret = btrfs_insert_empty_item(trans, uuid_root, path, &key,
113 sizeof(subid_le));
114 if (ret >= 0) {
115
116 eb = path->nodes[0];
117 slot = path->slots[0];
118 offset = btrfs_item_ptr_offset(eb, slot);
119 } else if (ret == -EEXIST) {
120
121
122
123
124 btrfs_extend_item(path, sizeof(subid_le));
125 eb = path->nodes[0];
126 slot = path->slots[0];
127 offset = btrfs_item_ptr_offset(eb, slot);
128 offset += btrfs_item_size_nr(eb, slot) - sizeof(subid_le);
129 } else {
130 btrfs_warn(fs_info,
131 "insert uuid item failed %d (0x%016llx, 0x%016llx) type %u!",
132 ret, (unsigned long long)key.objectid,
133 (unsigned long long)key.offset, type);
134 goto out;
135 }
136
137 ret = 0;
138 subid_le = cpu_to_le64(subid_cpu);
139 write_extent_buffer(eb, &subid_le, offset, sizeof(subid_le));
140 btrfs_mark_buffer_dirty(eb);
141
142out:
143 btrfs_free_path(path);
144 return ret;
145}
146
147int btrfs_uuid_tree_remove(struct btrfs_trans_handle *trans, u8 *uuid, u8 type,
148 u64 subid)
149{
150 struct btrfs_fs_info *fs_info = trans->fs_info;
151 struct btrfs_root *uuid_root = fs_info->uuid_root;
152 int ret;
153 struct btrfs_path *path = NULL;
154 struct btrfs_key key;
155 struct extent_buffer *eb;
156 int slot;
157 unsigned long offset;
158 u32 item_size;
159 unsigned long move_dst;
160 unsigned long move_src;
161 unsigned long move_len;
162
163 if (WARN_ON_ONCE(!uuid_root)) {
164 ret = -EINVAL;
165 goto out;
166 }
167
168 btrfs_uuid_to_key(uuid, type, &key);
169
170 path = btrfs_alloc_path();
171 if (!path) {
172 ret = -ENOMEM;
173 goto out;
174 }
175
176 ret = btrfs_search_slot(trans, uuid_root, &key, path, -1, 1);
177 if (ret < 0) {
178 btrfs_warn(fs_info, "error %d while searching for uuid item!",
179 ret);
180 goto out;
181 }
182 if (ret > 0) {
183 ret = -ENOENT;
184 goto out;
185 }
186
187 eb = path->nodes[0];
188 slot = path->slots[0];
189 offset = btrfs_item_ptr_offset(eb, slot);
190 item_size = btrfs_item_size_nr(eb, slot);
191 if (!IS_ALIGNED(item_size, sizeof(u64))) {
192 btrfs_warn(fs_info, "uuid item with illegal size %lu!",
193 (unsigned long)item_size);
194 ret = -ENOENT;
195 goto out;
196 }
197 while (item_size) {
198 __le64 read_subid;
199
200 read_extent_buffer(eb, &read_subid, offset, sizeof(read_subid));
201 if (le64_to_cpu(read_subid) == subid)
202 break;
203 offset += sizeof(read_subid);
204 item_size -= sizeof(read_subid);
205 }
206
207 if (!item_size) {
208 ret = -ENOENT;
209 goto out;
210 }
211
212 item_size = btrfs_item_size_nr(eb, slot);
213 if (item_size == sizeof(subid)) {
214 ret = btrfs_del_item(trans, uuid_root, path);
215 goto out;
216 }
217
218 move_dst = offset;
219 move_src = offset + sizeof(subid);
220 move_len = item_size - (move_src - btrfs_item_ptr_offset(eb, slot));
221 memmove_extent_buffer(eb, move_dst, move_src, move_len);
222 btrfs_truncate_item(path, item_size - sizeof(subid), 1);
223
224out:
225 btrfs_free_path(path);
226 return ret;
227}
228
229static int btrfs_uuid_iter_rem(struct btrfs_root *uuid_root, u8 *uuid, u8 type,
230 u64 subid)
231{
232 struct btrfs_trans_handle *trans;
233 int ret;
234
235
236 trans = btrfs_start_transaction(uuid_root, 1);
237 if (IS_ERR(trans)) {
238 ret = PTR_ERR(trans);
239 goto out;
240 }
241
242 ret = btrfs_uuid_tree_remove(trans, uuid, type, subid);
243 btrfs_end_transaction(trans);
244
245out:
246 return ret;
247}
248
249int btrfs_uuid_tree_iterate(struct btrfs_fs_info *fs_info,
250 int (*check_func)(struct btrfs_fs_info *, u8 *, u8,
251 u64))
252{
253 struct btrfs_root *root = fs_info->uuid_root;
254 struct btrfs_key key;
255 struct btrfs_path *path;
256 int ret = 0;
257 struct extent_buffer *leaf;
258 int slot;
259 u32 item_size;
260 unsigned long offset;
261
262 path = btrfs_alloc_path();
263 if (!path) {
264 ret = -ENOMEM;
265 goto out;
266 }
267
268 key.objectid = 0;
269 key.type = 0;
270 key.offset = 0;
271
272again_search_slot:
273 ret = btrfs_search_forward(root, &key, path, BTRFS_OLDEST_GENERATION);
274 if (ret) {
275 if (ret > 0)
276 ret = 0;
277 goto out;
278 }
279
280 while (1) {
281 cond_resched();
282 leaf = path->nodes[0];
283 slot = path->slots[0];
284 btrfs_item_key_to_cpu(leaf, &key, slot);
285
286 if (key.type != BTRFS_UUID_KEY_SUBVOL &&
287 key.type != BTRFS_UUID_KEY_RECEIVED_SUBVOL)
288 goto skip;
289
290 offset = btrfs_item_ptr_offset(leaf, slot);
291 item_size = btrfs_item_size_nr(leaf, slot);
292 if (!IS_ALIGNED(item_size, sizeof(u64))) {
293 btrfs_warn(fs_info,
294 "uuid item with illegal size %lu!",
295 (unsigned long)item_size);
296 goto skip;
297 }
298 while (item_size) {
299 u8 uuid[BTRFS_UUID_SIZE];
300 __le64 subid_le;
301 u64 subid_cpu;
302
303 put_unaligned_le64(key.objectid, uuid);
304 put_unaligned_le64(key.offset, uuid + sizeof(u64));
305 read_extent_buffer(leaf, &subid_le, offset,
306 sizeof(subid_le));
307 subid_cpu = le64_to_cpu(subid_le);
308 ret = check_func(fs_info, uuid, key.type, subid_cpu);
309 if (ret < 0)
310 goto out;
311 if (ret > 0) {
312 btrfs_release_path(path);
313 ret = btrfs_uuid_iter_rem(root, uuid, key.type,
314 subid_cpu);
315 if (ret == 0) {
316
317
318
319
320
321
322
323 goto again_search_slot;
324 }
325 if (ret < 0 && ret != -ENOENT)
326 goto out;
327 }
328 item_size -= sizeof(subid_le);
329 offset += sizeof(subid_le);
330 }
331
332skip:
333 ret = btrfs_next_item(root, path);
334 if (ret == 0)
335 continue;
336 else if (ret > 0)
337 ret = 0;
338 break;
339 }
340
341out:
342 btrfs_free_path(path);
343 return ret;
344}
345
