ocfs2: fix locking for res->tracking and dlm->tracking_list
[linux/fpc-iii.git] / fs / btrfs / uuid-tree.c
blob837a9a8d579e9968c5d581ee74adcbc2419381a6
1 /*
2 * Copyright (C) STRATO AG 2013. All rights reserved.
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.
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.
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.
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"
26 static void btrfs_uuid_to_key(u8 *uuid, u8 type, struct btrfs_key *key)
28 key->type = type;
29 key->objectid = get_unaligned_le64(uuid);
30 key->offset = get_unaligned_le64(uuid + sizeof(u64));
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)
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;
45 if (WARN_ON_ONCE(!uuid_root)) {
46 ret = -ENOENT;
47 goto out;
50 path = btrfs_alloc_path();
51 if (!path) {
52 ret = -ENOMEM;
53 goto out;
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;
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;
71 if (!IS_ALIGNED(item_size, sizeof(u64))) {
72 btrfs_warn(uuid_root->fs_info, "uuid item with illegal size %lu!",
73 (unsigned long)item_size);
74 goto out;
76 while (item_size) {
77 __le64 data;
79 read_extent_buffer(eb, &data, offset, sizeof(data));
80 if (le64_to_cpu(data) == subid) {
81 ret = 0;
82 break;
84 offset += sizeof(data);
85 item_size -= sizeof(data);
88 out:
89 btrfs_free_path(path);
90 return ret;
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)
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;
105 ret = btrfs_uuid_tree_lookup(uuid_root, uuid, type, subid_cpu);
106 if (ret != -ENOENT)
107 return ret;
109 if (WARN_ON_ONCE(!uuid_root)) {
110 ret = -EINVAL;
111 goto out;
114 btrfs_uuid_to_key(uuid, type, &key);
116 path = btrfs_alloc_path();
117 if (!path) {
118 ret = -ENOMEM;
119 goto out;
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) {
131 * An item with that type already exists.
132 * Extend the item and store the new subid at the end.
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 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 goto out;
147 ret = 0;
148 subid_le = cpu_to_le64(subid_cpu);
149 write_extent_buffer(eb, &subid_le, offset, sizeof(subid_le));
150 btrfs_mark_buffer_dirty(eb);
152 out:
153 btrfs_free_path(path);
154 return ret;
157 int btrfs_uuid_tree_rem(struct btrfs_trans_handle *trans,
158 struct btrfs_root *uuid_root, u8 *uuid, u8 type,
159 u64 subid)
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;
172 if (WARN_ON_ONCE(!uuid_root)) {
173 ret = -EINVAL;
174 goto out;
177 btrfs_uuid_to_key(uuid, type, &key);
179 path = btrfs_alloc_path();
180 if (!path) {
181 ret = -ENOMEM;
182 goto out;
185 ret = btrfs_search_slot(trans, uuid_root, &key, path, -1, 1);
186 if (ret < 0) {
187 btrfs_warn(uuid_root->fs_info, "error %d while searching for uuid item!",
188 ret);
189 goto out;
191 if (ret > 0) {
192 ret = -ENOENT;
193 goto out;
196 eb = path->nodes[0];
197 slot = path->slots[0];
198 offset = btrfs_item_ptr_offset(eb, slot);
199 item_size = btrfs_item_size_nr(eb, slot);
200 if (!IS_ALIGNED(item_size, sizeof(u64))) {
201 btrfs_warn(uuid_root->fs_info, "uuid item with illegal size %lu!",
202 (unsigned long)item_size);
203 ret = -ENOENT;
204 goto out;
206 while (item_size) {
207 __le64 read_subid;
209 read_extent_buffer(eb, &read_subid, offset, sizeof(read_subid));
210 if (le64_to_cpu(read_subid) == subid)
211 break;
212 offset += sizeof(read_subid);
213 item_size -= sizeof(read_subid);
216 if (!item_size) {
217 ret = -ENOENT;
218 goto out;
221 item_size = btrfs_item_size_nr(eb, slot);
222 if (item_size == sizeof(subid)) {
223 ret = btrfs_del_item(trans, uuid_root, path);
224 goto out;
227 move_dst = offset;
228 move_src = offset + sizeof(subid);
229 move_len = item_size - (move_src - btrfs_item_ptr_offset(eb, slot));
230 memmove_extent_buffer(eb, move_dst, move_src, move_len);
231 btrfs_truncate_item(uuid_root, path, item_size - sizeof(subid), 1);
233 out:
234 btrfs_free_path(path);
235 return ret;
238 static int btrfs_uuid_iter_rem(struct btrfs_root *uuid_root, u8 *uuid, u8 type,
239 u64 subid)
241 struct btrfs_trans_handle *trans;
242 int ret;
244 /* 1 - for the uuid item */
245 trans = btrfs_start_transaction(uuid_root, 1);
246 if (IS_ERR(trans)) {
247 ret = PTR_ERR(trans);
248 goto out;
251 ret = btrfs_uuid_tree_rem(trans, uuid_root, uuid, type, subid);
252 btrfs_end_transaction(trans, uuid_root);
254 out:
255 return ret;
258 int btrfs_uuid_tree_iterate(struct btrfs_fs_info *fs_info,
259 int (*check_func)(struct btrfs_fs_info *, u8 *, u8,
260 u64))
262 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;
271 path = btrfs_alloc_path();
272 if (!path) {
273 ret = -ENOMEM;
274 goto out;
277 key.objectid = 0;
278 key.type = 0;
279 key.offset = 0;
281 again_search_slot:
282 ret = btrfs_search_forward(root, &key, path, 0);
283 if (ret) {
284 if (ret > 0)
285 ret = 0;
286 goto out;
289 while (1) {
290 cond_resched();
291 leaf = path->nodes[0];
292 slot = path->slots[0];
293 btrfs_item_key_to_cpu(leaf, &key, slot);
295 if (key.type != BTRFS_UUID_KEY_SUBVOL &&
296 key.type != BTRFS_UUID_KEY_RECEIVED_SUBVOL)
297 goto skip;
299 offset = btrfs_item_ptr_offset(leaf, slot);
300 item_size = btrfs_item_size_nr(leaf, slot);
301 if (!IS_ALIGNED(item_size, sizeof(u64))) {
302 btrfs_warn(fs_info, "uuid item with illegal size %lu!",
303 (unsigned long)item_size);
304 goto skip;
306 while (item_size) {
307 u8 uuid[BTRFS_UUID_SIZE];
308 __le64 subid_le;
309 u64 subid_cpu;
311 put_unaligned_le64(key.objectid, uuid);
312 put_unaligned_le64(key.offset, uuid + sizeof(u64));
313 read_extent_buffer(leaf, &subid_le, offset,
314 sizeof(subid_le));
315 subid_cpu = le64_to_cpu(subid_le);
316 ret = check_func(fs_info, uuid, key.type, subid_cpu);
317 if (ret < 0)
318 goto out;
319 if (ret > 0) {
320 btrfs_release_path(path);
321 ret = btrfs_uuid_iter_rem(root, uuid, key.type,
322 subid_cpu);
323 if (ret == 0) {
325 * this might look inefficient, but the
326 * justification is that it is an
327 * exception that check_func returns 1,
328 * and that in the regular case only one
329 * entry per UUID exists.
331 goto again_search_slot;
333 if (ret < 0 && ret != -ENOENT)
334 goto out;
336 item_size -= sizeof(subid_le);
337 offset += sizeof(subid_le);
340 skip:
341 ret = btrfs_next_item(root, path);
342 if (ret == 0)
343 continue;
344 else if (ret > 0)
345 ret = 0;
346 break;
349 out:
350 btrfs_free_path(path);
351 return ret;