Line data Source code
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 : {
28 495 : key->type = type;
29 495 : key->objectid = get_unaligned_le64(uuid);
30 495 : 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 */
34 231 : 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 :
45 231 : if (WARN_ON_ONCE(!uuid_root)) {
46 : ret = -ENOENT;
47 : goto out;
48 : }
49 :
50 231 : path = btrfs_alloc_path();
51 231 : if (!path) {
52 : ret = -ENOMEM;
53 : goto out;
54 : }
55 :
56 : btrfs_uuid_to_key(uuid, type, &key);
57 231 : ret = btrfs_search_slot(NULL, uuid_root, &key, path, 0, 0);
58 231 : if (ret < 0) {
59 : goto out;
60 231 : } else if (ret > 0) {
61 : ret = -ENOENT;
62 : goto out;
63 : }
64 :
65 0 : eb = path->nodes[0];
66 0 : slot = path->slots[0];
67 : item_size = btrfs_item_size_nr(eb, slot);
68 0 : offset = btrfs_item_ptr_offset(eb, slot);
69 : ret = -ENOENT;
70 :
71 0 : if (!IS_ALIGNED(item_size, sizeof(u64))) {
72 0 : btrfs_warn(uuid_root->fs_info, "uuid item with illegal size %lu!",
73 : (unsigned long)item_size);
74 0 : goto out;
75 : }
76 0 : while (item_size) {
77 : __le64 data;
78 :
79 0 : read_extent_buffer(eb, &data, offset, sizeof(data));
80 0 : if (le64_to_cpu(data) == subid) {
81 : ret = 0;
82 0 : break;
83 : }
84 0 : offset += sizeof(data);
85 0 : item_size -= sizeof(data);
86 : }
87 :
88 : out:
89 231 : btrfs_free_path(path);
90 231 : return ret;
91 : }
92 :
93 231 : 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 :
105 231 : ret = btrfs_uuid_tree_lookup(uuid_root, uuid, type, subid_cpu);
106 231 : if (ret != -ENOENT)
107 : return ret;
108 :
109 231 : if (WARN_ON_ONCE(!uuid_root)) {
110 : ret = -EINVAL;
111 : goto out;
112 : }
113 :
114 : btrfs_uuid_to_key(uuid, type, &key);
115 :
116 231 : path = btrfs_alloc_path();
117 231 : 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));
124 231 : if (ret >= 0) {
125 : /* Add an item for the type for the first time */
126 231 : eb = path->nodes[0];
127 231 : slot = path->slots[0];
128 231 : offset = btrfs_item_ptr_offset(eb, slot);
129 0 : } 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 0 : btrfs_extend_item(uuid_root, path, sizeof(subid_le));
135 0 : eb = path->nodes[0];
136 0 : slot = path->slots[0];
137 0 : offset = btrfs_item_ptr_offset(eb, slot);
138 0 : offset += btrfs_item_size_nr(eb, slot) - sizeof(subid_le);
139 0 : } else if (ret < 0) {
140 0 : btrfs_warn(uuid_root->fs_info, "insert uuid item failed %d "
141 : "(0x%016llx, 0x%016llx) type %u!",
142 : ret, (unsigned long long)key.objectid,
143 : (unsigned long long)key.offset, type);
144 0 : goto out;
145 : }
146 :
147 : ret = 0;
148 231 : subid_le = cpu_to_le64(subid_cpu);
149 231 : write_extent_buffer(eb, &subid_le, offset, sizeof(subid_le));
150 231 : btrfs_mark_buffer_dirty(eb);
151 :
152 : out:
153 231 : btrfs_free_path(path);
154 231 : return ret;
155 : }
156 :
157 33 : int btrfs_uuid_tree_rem(struct btrfs_trans_handle *trans,
158 : struct btrfs_root *uuid_root, u8 *uuid, u8 type,
159 : u64 subid)
160 : {
161 : int ret;
162 : struct btrfs_path *path = NULL;
163 : struct btrfs_key key;
164 : struct extent_buffer *eb;
165 : int slot;
166 : unsigned long offset;
167 : u32 item_size;
168 : unsigned long move_dst;
169 : unsigned long move_src;
170 : unsigned long move_len;
171 :
172 33 : if (WARN_ON_ONCE(!uuid_root)) {
173 : ret = -EINVAL;
174 : goto out;
175 : }
176 :
177 : btrfs_uuid_to_key(uuid, type, &key);
178 :
179 33 : path = btrfs_alloc_path();
180 33 : if (!path) {
181 : ret = -ENOMEM;
182 : goto out;
183 : }
184 :
185 33 : ret = btrfs_search_slot(trans, uuid_root, &key, path, -1, 1);
186 33 : if (ret < 0) {
187 0 : btrfs_warn(uuid_root->fs_info, "error %d while searching for uuid item!",
188 : ret);
189 0 : goto out;
190 : }
191 33 : if (ret > 0) {
192 : ret = -ENOENT;
193 : goto out;
194 : }
195 :
196 33 : eb = path->nodes[0];
197 33 : slot = path->slots[0];
198 33 : offset = btrfs_item_ptr_offset(eb, slot);
199 : item_size = btrfs_item_size_nr(eb, slot);
200 33 : if (!IS_ALIGNED(item_size, sizeof(u64))) {
201 0 : btrfs_warn(uuid_root->fs_info, "uuid item with illegal size %lu!",
202 : (unsigned long)item_size);
203 : ret = -ENOENT;
204 0 : goto out;
205 : }
206 33 : while (item_size) {
207 : __le64 read_subid;
208 :
209 33 : read_extent_buffer(eb, &read_subid, offset, sizeof(read_subid));
210 33 : if (le64_to_cpu(read_subid) == subid)
211 : break;
212 0 : offset += sizeof(read_subid);
213 0 : item_size -= sizeof(read_subid);
214 : }
215 :
216 33 : if (!item_size) {
217 : ret = -ENOENT;
218 : goto out;
219 : }
220 :
221 : item_size = btrfs_item_size_nr(eb, slot);
222 33 : if (item_size == sizeof(subid)) {
223 : ret = btrfs_del_item(trans, uuid_root, path);
224 33 : goto out;
225 : }
226 :
227 : move_dst = offset;
228 0 : move_src = offset + sizeof(subid);
229 0 : move_len = item_size - (move_src - btrfs_item_ptr_offset(eb, slot));
230 0 : memmove_extent_buffer(eb, move_dst, move_src, move_len);
231 0 : btrfs_truncate_item(uuid_root, path, item_size - sizeof(subid), 1);
232 :
233 : out:
234 33 : btrfs_free_path(path);
235 33 : return ret;
236 : }
237 :
238 0 : static int btrfs_uuid_iter_rem(struct btrfs_root *uuid_root, u8 *uuid, u8 type,
239 : u64 subid)
240 : {
241 : struct btrfs_trans_handle *trans;
242 : int ret;
243 :
244 : /* 1 - for the uuid item */
245 0 : trans = btrfs_start_transaction(uuid_root, 1);
246 0 : if (IS_ERR(trans)) {
247 0 : ret = PTR_ERR(trans);
248 0 : goto out;
249 : }
250 :
251 0 : ret = btrfs_uuid_tree_rem(trans, uuid_root, uuid, type, subid);
252 0 : btrfs_end_transaction(trans, uuid_root);
253 :
254 : out:
255 0 : return ret;
256 : }
257 :
258 0 : int btrfs_uuid_tree_iterate(struct btrfs_fs_info *fs_info,
259 : int (*check_func)(struct btrfs_fs_info *, u8 *, u8,
260 : u64))
261 : {
262 0 : struct btrfs_root *root = fs_info->uuid_root;
263 : struct btrfs_key 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 0 : path = btrfs_alloc_path();
272 0 : if (!path) {
273 : ret = -ENOMEM;
274 : goto out;
275 : }
276 :
277 0 : key.objectid = 0;
278 0 : key.type = 0;
279 0 : key.offset = 0;
280 :
281 : again_search_slot:
282 0 : path->keep_locks = 1;
283 0 : ret = btrfs_search_forward(root, &key, path, 0);
284 0 : if (ret) {
285 0 : if (ret > 0)
286 : ret = 0;
287 : goto out;
288 : }
289 :
290 : while (1) {
291 0 : cond_resched();
292 0 : leaf = path->nodes[0];
293 0 : slot = path->slots[0];
294 0 : btrfs_item_key_to_cpu(leaf, &key, slot);
295 :
296 0 : if (key.type != BTRFS_UUID_KEY_SUBVOL &&
297 : key.type != BTRFS_UUID_KEY_RECEIVED_SUBVOL)
298 : goto skip;
299 :
300 0 : offset = btrfs_item_ptr_offset(leaf, slot);
301 : item_size = btrfs_item_size_nr(leaf, slot);
302 0 : if (!IS_ALIGNED(item_size, sizeof(u64))) {
303 0 : btrfs_warn(fs_info, "uuid item with illegal size %lu!",
304 : (unsigned long)item_size);
305 0 : goto skip;
306 : }
307 0 : while (item_size) {
308 : u8 uuid[BTRFS_UUID_SIZE];
309 : __le64 subid_le;
310 : u64 subid_cpu;
311 :
312 0 : put_unaligned_le64(key.objectid, uuid);
313 0 : put_unaligned_le64(key.offset, uuid + sizeof(u64));
314 0 : read_extent_buffer(leaf, &subid_le, offset,
315 : sizeof(subid_le));
316 0 : subid_cpu = le64_to_cpu(subid_le);
317 0 : ret = check_func(fs_info, uuid, key.type, subid_cpu);
318 0 : if (ret < 0)
319 : goto out;
320 0 : if (ret > 0) {
321 0 : btrfs_release_path(path);
322 0 : ret = btrfs_uuid_iter_rem(root, uuid, key.type,
323 : subid_cpu);
324 0 : if (ret == 0) {
325 : /*
326 : * this might look inefficient, but the
327 : * justification is that it is an
328 : * exception that check_func returns 1,
329 : * and that in the regular case only one
330 : * entry per UUID exists.
331 : */
332 : goto again_search_slot;
333 : }
334 0 : if (ret < 0 && ret != -ENOENT)
335 : goto out;
336 : }
337 0 : item_size -= sizeof(subid_le);
338 0 : offset += sizeof(subid_le);
339 : }
340 :
341 : skip:
342 : ret = btrfs_next_item(root, path);
343 0 : if (ret == 0)
344 0 : continue;
345 0 : else if (ret > 0)
346 : ret = 0;
347 : break;
348 0 : }
349 :
350 : out:
351 0 : btrfs_free_path(path);
352 0 : if (ret)
353 0 : btrfs_warn(fs_info, "btrfs_uuid_tree_iterate failed %d", ret);
354 0 : return 0;
355 : }
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