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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 | btrfs_warn(uuid_root->fs_info, | |
73 | "uuid item with illegal size %lu!", | |
74 | (unsigned long)item_size); | |
75 | goto out; | |
76 | } | |
77 | while (item_size) { | |
78 | __le64 data; | |
79 | ||
80 | read_extent_buffer(eb, &data, offset, sizeof(data)); | |
81 | if (le64_to_cpu(data) == subid) { | |
82 | ret = 0; | |
83 | break; | |
84 | } | |
85 | offset += sizeof(data); | |
86 | item_size -= sizeof(data); | |
87 | } | |
88 | ||
89 | out: | |
90 | btrfs_free_path(path); | |
91 | return ret; | |
92 | } | |
93 | ||
94 | int btrfs_uuid_tree_add(struct btrfs_trans_handle *trans, | |
95 | struct btrfs_root *uuid_root, u8 *uuid, u8 type, | |
96 | u64 subid_cpu) | |
97 | { | |
98 | int ret; | |
99 | struct btrfs_path *path = NULL; | |
100 | struct btrfs_key key; | |
101 | struct extent_buffer *eb; | |
102 | int slot; | |
103 | unsigned long offset; | |
104 | __le64 subid_le; | |
105 | ||
106 | ret = btrfs_uuid_tree_lookup(uuid_root, uuid, type, subid_cpu); | |
107 | if (ret != -ENOENT) | |
108 | return ret; | |
109 | ||
110 | if (WARN_ON_ONCE(!uuid_root)) { | |
111 | ret = -EINVAL; | |
112 | goto out; | |
113 | } | |
114 | ||
115 | btrfs_uuid_to_key(uuid, type, &key); | |
116 | ||
117 | path = btrfs_alloc_path(); | |
118 | if (!path) { | |
119 | ret = -ENOMEM; | |
120 | goto out; | |
121 | } | |
122 | ||
123 | ret = btrfs_insert_empty_item(trans, uuid_root, path, &key, | |
124 | sizeof(subid_le)); | |
125 | if (ret >= 0) { | |
126 | /* Add an item for the type for the first time */ | |
127 | eb = path->nodes[0]; | |
128 | slot = path->slots[0]; | |
129 | offset = btrfs_item_ptr_offset(eb, slot); | |
130 | } else if (ret == -EEXIST) { | |
131 | /* | |
132 | * An item with that type already exists. | |
133 | * Extend the item and store the new subid at the end. | |
134 | */ | |
135 | btrfs_extend_item(uuid_root, path, sizeof(subid_le)); | |
136 | eb = path->nodes[0]; | |
137 | slot = path->slots[0]; | |
138 | offset = btrfs_item_ptr_offset(eb, slot); | |
139 | offset += btrfs_item_size_nr(eb, slot) - sizeof(subid_le); | |
140 | } else if (ret < 0) { | |
141 | btrfs_warn(uuid_root->fs_info, | |
142 | "insert uuid item failed %d (0x%016llx, 0x%016llx) type %u!", | |
143 | ret, (unsigned long long)key.objectid, | |
144 | (unsigned long long)key.offset, type); | |
145 | goto out; | |
146 | } | |
147 | ||
148 | ret = 0; | |
149 | subid_le = cpu_to_le64(subid_cpu); | |
150 | write_extent_buffer(eb, &subid_le, offset, sizeof(subid_le)); | |
151 | btrfs_mark_buffer_dirty(eb); | |
152 | ||
153 | out: | |
154 | btrfs_free_path(path); | |
155 | return ret; | |
156 | } | |
157 | ||
158 | int btrfs_uuid_tree_rem(struct btrfs_trans_handle *trans, | |
159 | struct btrfs_root *uuid_root, u8 *uuid, u8 type, | |
160 | u64 subid) | |
161 | { | |
162 | int ret; | |
163 | struct btrfs_path *path = NULL; | |
164 | struct btrfs_key key; | |
165 | struct extent_buffer *eb; | |
166 | int slot; | |
167 | unsigned long offset; | |
168 | u32 item_size; | |
169 | unsigned long move_dst; | |
170 | unsigned long move_src; | |
171 | unsigned long move_len; | |
172 | ||
173 | if (WARN_ON_ONCE(!uuid_root)) { | |
174 | ret = -EINVAL; | |
175 | goto out; | |
176 | } | |
177 | ||
178 | btrfs_uuid_to_key(uuid, type, &key); | |
179 | ||
180 | path = btrfs_alloc_path(); | |
181 | if (!path) { | |
182 | ret = -ENOMEM; | |
183 | goto out; | |
184 | } | |
185 | ||
186 | ret = btrfs_search_slot(trans, uuid_root, &key, path, -1, 1); | |
187 | if (ret < 0) { | |
188 | btrfs_warn(uuid_root->fs_info, | |
189 | "error %d while searching for uuid item!", ret); | |
190 | goto out; | |
191 | } | |
192 | if (ret > 0) { | |
193 | ret = -ENOENT; | |
194 | goto out; | |
195 | } | |
196 | ||
197 | eb = path->nodes[0]; | |
198 | slot = path->slots[0]; | |
199 | offset = btrfs_item_ptr_offset(eb, slot); | |
200 | item_size = btrfs_item_size_nr(eb, slot); | |
201 | if (!IS_ALIGNED(item_size, sizeof(u64))) { | |
202 | btrfs_warn(uuid_root->fs_info, | |
203 | "uuid item with illegal size %lu!", | |
204 | (unsigned long)item_size); | |
205 | ret = -ENOENT; | |
206 | goto out; | |
207 | } | |
208 | while (item_size) { | |
209 | __le64 read_subid; | |
210 | ||
211 | read_extent_buffer(eb, &read_subid, offset, sizeof(read_subid)); | |
212 | if (le64_to_cpu(read_subid) == subid) | |
213 | break; | |
214 | offset += sizeof(read_subid); | |
215 | item_size -= sizeof(read_subid); | |
216 | } | |
217 | ||
218 | if (!item_size) { | |
219 | ret = -ENOENT; | |
220 | goto out; | |
221 | } | |
222 | ||
223 | item_size = btrfs_item_size_nr(eb, slot); | |
224 | if (item_size == sizeof(subid)) { | |
225 | ret = btrfs_del_item(trans, uuid_root, path); | |
226 | goto out; | |
227 | } | |
228 | ||
229 | move_dst = offset; | |
230 | move_src = offset + sizeof(subid); | |
231 | move_len = item_size - (move_src - btrfs_item_ptr_offset(eb, slot)); | |
232 | memmove_extent_buffer(eb, move_dst, move_src, move_len); | |
233 | btrfs_truncate_item(uuid_root, path, item_size - sizeof(subid), 1); | |
234 | ||
235 | out: | |
236 | btrfs_free_path(path); | |
237 | return ret; | |
238 | } | |
239 | ||
240 | static int btrfs_uuid_iter_rem(struct btrfs_root *uuid_root, u8 *uuid, u8 type, | |
241 | u64 subid) | |
242 | { | |
243 | struct btrfs_trans_handle *trans; | |
244 | int ret; | |
245 | ||
246 | /* 1 - for the uuid item */ | |
247 | trans = btrfs_start_transaction(uuid_root, 1); | |
248 | if (IS_ERR(trans)) { | |
249 | ret = PTR_ERR(trans); | |
250 | goto out; | |
251 | } | |
252 | ||
253 | ret = btrfs_uuid_tree_rem(trans, uuid_root, uuid, type, subid); | |
254 | btrfs_end_transaction(trans, uuid_root); | |
255 | ||
256 | out: | |
257 | return ret; | |
258 | } | |
259 | ||
260 | int btrfs_uuid_tree_iterate(struct btrfs_fs_info *fs_info, | |
261 | int (*check_func)(struct btrfs_fs_info *, u8 *, u8, | |
262 | u64)) | |
263 | { | |
264 | struct btrfs_root *root = fs_info->uuid_root; | |
265 | struct btrfs_key key; | |
266 | struct btrfs_path *path; | |
267 | int ret = 0; | |
268 | struct extent_buffer *leaf; | |
269 | int slot; | |
270 | u32 item_size; | |
271 | unsigned long offset; | |
272 | ||
273 | path = btrfs_alloc_path(); | |
274 | if (!path) { | |
275 | ret = -ENOMEM; | |
276 | goto out; | |
277 | } | |
278 | ||
279 | key.objectid = 0; | |
280 | key.type = 0; | |
281 | key.offset = 0; | |
282 | ||
283 | again_search_slot: | |
284 | ret = btrfs_search_forward(root, &key, path, 0); | |
285 | if (ret) { | |
286 | if (ret > 0) | |
287 | ret = 0; | |
288 | goto out; | |
289 | } | |
290 | ||
291 | while (1) { | |
292 | cond_resched(); | |
293 | leaf = path->nodes[0]; | |
294 | slot = path->slots[0]; | |
295 | btrfs_item_key_to_cpu(leaf, &key, slot); | |
296 | ||
297 | if (key.type != BTRFS_UUID_KEY_SUBVOL && | |
298 | key.type != BTRFS_UUID_KEY_RECEIVED_SUBVOL) | |
299 | goto skip; | |
300 | ||
301 | offset = btrfs_item_ptr_offset(leaf, slot); | |
302 | item_size = btrfs_item_size_nr(leaf, slot); | |
303 | if (!IS_ALIGNED(item_size, sizeof(u64))) { | |
304 | btrfs_warn(fs_info, | |
305 | "uuid item with illegal size %lu!", | |
306 | (unsigned long)item_size); | |
307 | goto skip; | |
308 | } | |
309 | while (item_size) { | |
310 | u8 uuid[BTRFS_UUID_SIZE]; | |
311 | __le64 subid_le; | |
312 | u64 subid_cpu; | |
313 | ||
314 | put_unaligned_le64(key.objectid, uuid); | |
315 | put_unaligned_le64(key.offset, uuid + sizeof(u64)); | |
316 | read_extent_buffer(leaf, &subid_le, offset, | |
317 | sizeof(subid_le)); | |
318 | subid_cpu = le64_to_cpu(subid_le); | |
319 | ret = check_func(fs_info, uuid, key.type, subid_cpu); | |
320 | if (ret < 0) | |
321 | goto out; | |
322 | if (ret > 0) { | |
323 | btrfs_release_path(path); | |
324 | ret = btrfs_uuid_iter_rem(root, uuid, key.type, | |
325 | subid_cpu); | |
326 | if (ret == 0) { | |
327 | /* | |
328 | * this might look inefficient, but the | |
329 | * justification is that it is an | |
330 | * exception that check_func returns 1, | |
331 | * and that in the regular case only one | |
332 | * entry per UUID exists. | |
333 | */ | |
334 | goto again_search_slot; | |
335 | } | |
336 | if (ret < 0 && ret != -ENOENT) | |
337 | goto out; | |
338 | } | |
339 | item_size -= sizeof(subid_le); | |
340 | offset += sizeof(subid_le); | |
341 | } | |
342 | ||
343 | skip: | |
344 | ret = btrfs_next_item(root, path); | |
345 | if (ret == 0) | |
346 | continue; | |
347 | else if (ret > 0) | |
348 | ret = 0; | |
349 | break; | |
350 | } | |
351 | ||
352 | out: | |
353 | btrfs_free_path(path); | |
354 | if (ret) | |
355 | btrfs_warn(fs_info, "btrfs_uuid_tree_iterate failed %d", ret); | |
356 | return 0; | |
357 | } |