blob: dd0dea3766f740a0c58d741a4a0b1c63fd6b8038 [file] [log] [blame]
Stefan Behrens07b30a42013-08-15 17:11:17 +02001/*
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
26static 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 */
34static 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
88out:
89 btrfs_free_path(path);
90 return ret;
91}
92
93int 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
151out:
152 btrfs_free_path(path);
153 return ret;
154}
155
156int 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
232out:
233 btrfs_free_path(path);
234 return ret;
235}
Stefan Behrens70f80172013-08-15 17:11:23 +0200236
237static int btrfs_uuid_iter_rem(struct btrfs_root *uuid_root, u8 *uuid, u8 type,
238 u64 subid)
239{
240 struct btrfs_trans_handle *trans;
241 int ret;
242
243 /* 1 - for the uuid item */
244 trans = btrfs_start_transaction(uuid_root, 1);
245 if (IS_ERR(trans)) {
246 ret = PTR_ERR(trans);
247 goto out;
248 }
249
250 ret = btrfs_uuid_tree_rem(trans, uuid_root, uuid, type, subid);
251 btrfs_end_transaction(trans, uuid_root);
252
253out:
254 return ret;
255}
256
257int btrfs_uuid_tree_iterate(struct btrfs_fs_info *fs_info,
258 int (*check_func)(struct btrfs_fs_info *, u8 *, u8,
259 u64))
260{
261 struct btrfs_root *root = fs_info->uuid_root;
262 struct btrfs_key key;
263 struct btrfs_key max_key;
264 struct btrfs_path *path;
265 int ret = 0;
266 struct extent_buffer *leaf;
267 int slot;
268 u32 item_size;
269 unsigned long offset;
270
271 path = btrfs_alloc_path();
272 if (!path) {
273 ret = -ENOMEM;
274 goto out;
275 }
276
277 key.objectid = 0;
278 key.type = 0;
279 key.offset = 0;
280 max_key.objectid = (u64)-1;
281 max_key.type = (u8)-1;
282 max_key.offset = (u64)-1;
283
284again_search_slot:
285 path->keep_locks = 1;
286 ret = btrfs_search_forward(root, &key, &max_key, path, 0);
287 if (ret) {
288 if (ret > 0)
289 ret = 0;
290 goto out;
291 }
292
293 while (1) {
294 cond_resched();
295 leaf = path->nodes[0];
296 slot = path->slots[0];
297 btrfs_item_key_to_cpu(leaf, &key, slot);
298
299 if (key.type != BTRFS_UUID_KEY_SUBVOL &&
300 key.type != BTRFS_UUID_KEY_RECEIVED_SUBVOL)
301 goto skip;
302
303 offset = btrfs_item_ptr_offset(leaf, slot);
304 item_size = btrfs_item_size_nr(leaf, slot);
305 if (!IS_ALIGNED(item_size, sizeof(u64))) {
306 pr_warn("btrfs: uuid item with illegal size %lu!\n",
307 (unsigned long)item_size);
308 goto skip;
309 }
310 while (item_size) {
311 u8 uuid[BTRFS_UUID_SIZE];
312 __le64 subid_le;
313 u64 subid_cpu;
314
315 put_unaligned_le64(key.objectid, uuid);
316 put_unaligned_le64(key.offset, uuid + sizeof(u64));
317 read_extent_buffer(leaf, &subid_le, offset,
318 sizeof(subid_le));
319 subid_cpu = le64_to_cpu(subid_le);
320 ret = check_func(fs_info, uuid, key.type, subid_cpu);
321 if (ret < 0)
322 goto out;
323 if (ret > 0) {
324 btrfs_release_path(path);
325 ret = btrfs_uuid_iter_rem(root, uuid, key.type,
326 subid_cpu);
327 if (ret == 0) {
328 /*
329 * this might look inefficient, but the
330 * justification is that it is an
331 * exception that check_func returns 1,
332 * and that in the regular case only one
333 * entry per UUID exists.
334 */
335 goto again_search_slot;
336 }
337 if (ret < 0 && ret != -ENOENT)
338 goto out;
339 }
340 item_size -= sizeof(subid_le);
341 offset += sizeof(subid_le);
342 }
343
344skip:
345 ret = btrfs_next_item(root, path);
346 if (ret == 0)
347 continue;
348 else if (ret > 0)
349 ret = 0;
350 break;
351 }
352
353out:
354 btrfs_free_path(path);
355 if (ret)
356 pr_warn("btrfs: btrfs_uuid_tree_iterate failed %d\n", ret);
357 return 0;
358}