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1/*
2 * Copyright (C) 2007 Oracle. 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
19#include "ctree.h"
20#include "disk-io.h"
21#include "transaction.h"
22
23static int find_name_in_backref(struct btrfs_path *path, const char *name,
24 int name_len, struct btrfs_inode_ref **ref_ret)
25{
26 struct extent_buffer *leaf;
27 struct btrfs_inode_ref *ref;
28 unsigned long ptr;
29 unsigned long name_ptr;
30 u32 item_size;
31 u32 cur_offset = 0;
32 int len;
33
34 leaf = path->nodes[0];
35 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
36 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
37 while (cur_offset < item_size) {
38 ref = (struct btrfs_inode_ref *)(ptr + cur_offset);
39 len = btrfs_inode_ref_name_len(leaf, ref);
40 name_ptr = (unsigned long)(ref + 1);
41 cur_offset += len + sizeof(*ref);
42 if (len != name_len)
43 continue;
44 if (memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0) {
45 *ref_ret = ref;
46 return 1;
47 }
48 }
49 return 0;
50}
51
52struct btrfs_inode_ref *
53btrfs_lookup_inode_ref(struct btrfs_trans_handle *trans,
54 struct btrfs_root *root,
55 struct btrfs_path *path,
56 const char *name, int name_len,
57 u64 inode_objectid, u64 ref_objectid, int mod)
58{
59 struct btrfs_key key;
60 struct btrfs_inode_ref *ref;
61 int ins_len = mod < 0 ? -1 : 0;
62 int cow = mod != 0;
63 int ret;
64
65 key.objectid = inode_objectid;
66 key.type = BTRFS_INODE_REF_KEY;
67 key.offset = ref_objectid;
68
69 ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
70 if (ret < 0)
71 return ERR_PTR(ret);
72 if (ret > 0)
73 return NULL;
74 if (!find_name_in_backref(path, name, name_len, &ref))
75 return NULL;
76 return ref;
77}
78
79int btrfs_del_inode_ref(struct btrfs_trans_handle *trans,
80 struct btrfs_root *root,
81 const char *name, int name_len,
82 u64 inode_objectid, u64 ref_objectid, u64 *index)
83{
84 struct btrfs_path *path;
85 struct btrfs_key key;
86 struct btrfs_inode_ref *ref;
87 struct extent_buffer *leaf;
88 unsigned long ptr;
89 unsigned long item_start;
90 u32 item_size;
91 u32 sub_item_len;
92 int ret;
93 int del_len = name_len + sizeof(*ref);
94
95 key.objectid = inode_objectid;
96 key.offset = ref_objectid;
97 btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY);
98
99 path = btrfs_alloc_path();
100 if (!path)
101 return -ENOMEM;
102
103 path->leave_spinning = 1;
104
105 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
106 if (ret > 0) {
107 ret = -ENOENT;
108 goto out;
109 } else if (ret < 0) {
110 goto out;
111 }
112 if (!find_name_in_backref(path, name, name_len, &ref)) {
113 ret = -ENOENT;
114 goto out;
115 }
116 leaf = path->nodes[0];
117 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
118
119 if (index)
120 *index = btrfs_inode_ref_index(leaf, ref);
121
122 if (del_len == item_size) {
123 ret = btrfs_del_item(trans, root, path);
124 goto out;
125 }
126 ptr = (unsigned long)ref;
127 sub_item_len = name_len + sizeof(*ref);
128 item_start = btrfs_item_ptr_offset(leaf, path->slots[0]);
129 memmove_extent_buffer(leaf, ptr, ptr + sub_item_len,
130 item_size - (ptr + sub_item_len - item_start));
131 ret = btrfs_truncate_item(trans, root, path,
132 item_size - sub_item_len, 1);
133out:
134 btrfs_free_path(path);
135 return ret;
136}
137
138int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans,
139 struct btrfs_root *root,
140 const char *name, int name_len,
141 u64 inode_objectid, u64 ref_objectid, u64 index)
142{
143 struct btrfs_path *path;
144 struct btrfs_key key;
145 struct btrfs_inode_ref *ref;
146 unsigned long ptr;
147 int ret;
148 int ins_len = name_len + sizeof(*ref);
149
150 key.objectid = inode_objectid;
151 key.offset = ref_objectid;
152 btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY);
153
154 path = btrfs_alloc_path();
155 if (!path)
156 return -ENOMEM;
157
158 path->leave_spinning = 1;
159 ret = btrfs_insert_empty_item(trans, root, path, &key,
160 ins_len);
161 if (ret == -EEXIST) {
162 u32 old_size;
163
164 if (find_name_in_backref(path, name, name_len, &ref))
165 goto out;
166
167 old_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
168 ret = btrfs_extend_item(trans, root, path, ins_len);
169 ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
170 struct btrfs_inode_ref);
171 ref = (struct btrfs_inode_ref *)((unsigned long)ref + old_size);
172 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
173 btrfs_set_inode_ref_index(path->nodes[0], ref, index);
174 ptr = (unsigned long)(ref + 1);
175 ret = 0;
176 } else if (ret < 0) {
177 if (ret == -EOVERFLOW)
178 ret = -EMLINK;
179 goto out;
180 } else {
181 ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
182 struct btrfs_inode_ref);
183 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
184 btrfs_set_inode_ref_index(path->nodes[0], ref, index);
185 ptr = (unsigned long)(ref + 1);
186 }
187 write_extent_buffer(path->nodes[0], name, ptr, name_len);
188 btrfs_mark_buffer_dirty(path->nodes[0]);
189
190out:
191 btrfs_free_path(path);
192 return ret;
193}
194
195int btrfs_insert_empty_inode(struct btrfs_trans_handle *trans,
196 struct btrfs_root *root,
197 struct btrfs_path *path, u64 objectid)
198{
199 struct btrfs_key key;
200 int ret;
201 key.objectid = objectid;
202 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
203 key.offset = 0;
204
205 ret = btrfs_insert_empty_item(trans, root, path, &key,
206 sizeof(struct btrfs_inode_item));
207 return ret;
208}
209
210int btrfs_lookup_inode(struct btrfs_trans_handle *trans, struct btrfs_root
211 *root, struct btrfs_path *path,
212 struct btrfs_key *location, int mod)
213{
214 int ins_len = mod < 0 ? -1 : 0;
215 int cow = mod != 0;
216 int ret;
217 int slot;
218 struct extent_buffer *leaf;
219 struct btrfs_key found_key;
220
221 ret = btrfs_search_slot(trans, root, location, path, ins_len, cow);
222 if (ret > 0 && btrfs_key_type(location) == BTRFS_ROOT_ITEM_KEY &&
223 location->offset == (u64)-1 && path->slots[0] != 0) {
224 slot = path->slots[0] - 1;
225 leaf = path->nodes[0];
226 btrfs_item_key_to_cpu(leaf, &found_key, slot);
227 if (found_key.objectid == location->objectid &&
228 btrfs_key_type(&found_key) == btrfs_key_type(location)) {
229 path->slots[0]--;
230 return 0;
231 }
232 }
233 return ret;
234}
1/*
2 * Copyright (C) 2007 Oracle. 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
19#include "ctree.h"
20#include "disk-io.h"
21#include "hash.h"
22#include "transaction.h"
23#include "print-tree.h"
24
25static int find_name_in_backref(struct btrfs_path *path, const char *name,
26 int name_len, struct btrfs_inode_ref **ref_ret)
27{
28 struct extent_buffer *leaf;
29 struct btrfs_inode_ref *ref;
30 unsigned long ptr;
31 unsigned long name_ptr;
32 u32 item_size;
33 u32 cur_offset = 0;
34 int len;
35
36 leaf = path->nodes[0];
37 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
38 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
39 while (cur_offset < item_size) {
40 ref = (struct btrfs_inode_ref *)(ptr + cur_offset);
41 len = btrfs_inode_ref_name_len(leaf, ref);
42 name_ptr = (unsigned long)(ref + 1);
43 cur_offset += len + sizeof(*ref);
44 if (len != name_len)
45 continue;
46 if (memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0) {
47 *ref_ret = ref;
48 return 1;
49 }
50 }
51 return 0;
52}
53
54int btrfs_find_name_in_ext_backref(struct btrfs_path *path, u64 ref_objectid,
55 const char *name, int name_len,
56 struct btrfs_inode_extref **extref_ret)
57{
58 struct extent_buffer *leaf;
59 struct btrfs_inode_extref *extref;
60 unsigned long ptr;
61 unsigned long name_ptr;
62 u32 item_size;
63 u32 cur_offset = 0;
64 int ref_name_len;
65
66 leaf = path->nodes[0];
67 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
68 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
69
70 /*
71 * Search all extended backrefs in this item. We're only
72 * looking through any collisions so most of the time this is
73 * just going to compare against one buffer. If all is well,
74 * we'll return success and the inode ref object.
75 */
76 while (cur_offset < item_size) {
77 extref = (struct btrfs_inode_extref *) (ptr + cur_offset);
78 name_ptr = (unsigned long)(&extref->name);
79 ref_name_len = btrfs_inode_extref_name_len(leaf, extref);
80
81 if (ref_name_len == name_len &&
82 btrfs_inode_extref_parent(leaf, extref) == ref_objectid &&
83 (memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0)) {
84 if (extref_ret)
85 *extref_ret = extref;
86 return 1;
87 }
88
89 cur_offset += ref_name_len + sizeof(*extref);
90 }
91 return 0;
92}
93
94/* Returns NULL if no extref found */
95struct btrfs_inode_extref *
96btrfs_lookup_inode_extref(struct btrfs_trans_handle *trans,
97 struct btrfs_root *root,
98 struct btrfs_path *path,
99 const char *name, int name_len,
100 u64 inode_objectid, u64 ref_objectid, int ins_len,
101 int cow)
102{
103 int ret;
104 struct btrfs_key key;
105 struct btrfs_inode_extref *extref;
106
107 key.objectid = inode_objectid;
108 key.type = BTRFS_INODE_EXTREF_KEY;
109 key.offset = btrfs_extref_hash(ref_objectid, name, name_len);
110
111 ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
112 if (ret < 0)
113 return ERR_PTR(ret);
114 if (ret > 0)
115 return NULL;
116 if (!btrfs_find_name_in_ext_backref(path, ref_objectid, name, name_len, &extref))
117 return NULL;
118 return extref;
119}
120
121static int btrfs_del_inode_extref(struct btrfs_trans_handle *trans,
122 struct btrfs_root *root,
123 const char *name, int name_len,
124 u64 inode_objectid, u64 ref_objectid,
125 u64 *index)
126{
127 struct btrfs_path *path;
128 struct btrfs_key key;
129 struct btrfs_inode_extref *extref;
130 struct extent_buffer *leaf;
131 int ret;
132 int del_len = name_len + sizeof(*extref);
133 unsigned long ptr;
134 unsigned long item_start;
135 u32 item_size;
136
137 key.objectid = inode_objectid;
138 btrfs_set_key_type(&key, BTRFS_INODE_EXTREF_KEY);
139 key.offset = btrfs_extref_hash(ref_objectid, name, name_len);
140
141 path = btrfs_alloc_path();
142 if (!path)
143 return -ENOMEM;
144
145 path->leave_spinning = 1;
146
147 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
148 if (ret > 0)
149 ret = -ENOENT;
150 if (ret < 0)
151 goto out;
152
153 /*
154 * Sanity check - did we find the right item for this name?
155 * This should always succeed so error here will make the FS
156 * readonly.
157 */
158 if (!btrfs_find_name_in_ext_backref(path, ref_objectid,
159 name, name_len, &extref)) {
160 btrfs_std_error(root->fs_info, -ENOENT);
161 ret = -EROFS;
162 goto out;
163 }
164
165 leaf = path->nodes[0];
166 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
167 if (index)
168 *index = btrfs_inode_extref_index(leaf, extref);
169
170 if (del_len == item_size) {
171 /*
172 * Common case only one ref in the item, remove the
173 * whole item.
174 */
175 ret = btrfs_del_item(trans, root, path);
176 goto out;
177 }
178
179 ptr = (unsigned long)extref;
180 item_start = btrfs_item_ptr_offset(leaf, path->slots[0]);
181
182 memmove_extent_buffer(leaf, ptr, ptr + del_len,
183 item_size - (ptr + del_len - item_start));
184
185 btrfs_truncate_item(root, path, item_size - del_len, 1);
186
187out:
188 btrfs_free_path(path);
189
190 return ret;
191}
192
193int btrfs_del_inode_ref(struct btrfs_trans_handle *trans,
194 struct btrfs_root *root,
195 const char *name, int name_len,
196 u64 inode_objectid, u64 ref_objectid, u64 *index)
197{
198 struct btrfs_path *path;
199 struct btrfs_key key;
200 struct btrfs_inode_ref *ref;
201 struct extent_buffer *leaf;
202 unsigned long ptr;
203 unsigned long item_start;
204 u32 item_size;
205 u32 sub_item_len;
206 int ret;
207 int search_ext_refs = 0;
208 int del_len = name_len + sizeof(*ref);
209
210 key.objectid = inode_objectid;
211 key.offset = ref_objectid;
212 btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY);
213
214 path = btrfs_alloc_path();
215 if (!path)
216 return -ENOMEM;
217
218 path->leave_spinning = 1;
219
220 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
221 if (ret > 0) {
222 ret = -ENOENT;
223 search_ext_refs = 1;
224 goto out;
225 } else if (ret < 0) {
226 goto out;
227 }
228 if (!find_name_in_backref(path, name, name_len, &ref)) {
229 ret = -ENOENT;
230 search_ext_refs = 1;
231 goto out;
232 }
233 leaf = path->nodes[0];
234 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
235
236 if (index)
237 *index = btrfs_inode_ref_index(leaf, ref);
238
239 if (del_len == item_size) {
240 ret = btrfs_del_item(trans, root, path);
241 goto out;
242 }
243 ptr = (unsigned long)ref;
244 sub_item_len = name_len + sizeof(*ref);
245 item_start = btrfs_item_ptr_offset(leaf, path->slots[0]);
246 memmove_extent_buffer(leaf, ptr, ptr + sub_item_len,
247 item_size - (ptr + sub_item_len - item_start));
248 btrfs_truncate_item(root, path, item_size - sub_item_len, 1);
249out:
250 btrfs_free_path(path);
251
252 if (search_ext_refs) {
253 /*
254 * No refs were found, or we could not find the
255 * name in our ref array. Find and remove the extended
256 * inode ref then.
257 */
258 return btrfs_del_inode_extref(trans, root, name, name_len,
259 inode_objectid, ref_objectid, index);
260 }
261
262 return ret;
263}
264
265/*
266 * btrfs_insert_inode_extref() - Inserts an extended inode ref into a tree.
267 *
268 * The caller must have checked against BTRFS_LINK_MAX already.
269 */
270static int btrfs_insert_inode_extref(struct btrfs_trans_handle *trans,
271 struct btrfs_root *root,
272 const char *name, int name_len,
273 u64 inode_objectid, u64 ref_objectid, u64 index)
274{
275 struct btrfs_inode_extref *extref;
276 int ret;
277 int ins_len = name_len + sizeof(*extref);
278 unsigned long ptr;
279 struct btrfs_path *path;
280 struct btrfs_key key;
281 struct extent_buffer *leaf;
282 struct btrfs_item *item;
283
284 key.objectid = inode_objectid;
285 key.type = BTRFS_INODE_EXTREF_KEY;
286 key.offset = btrfs_extref_hash(ref_objectid, name, name_len);
287
288 path = btrfs_alloc_path();
289 if (!path)
290 return -ENOMEM;
291
292 path->leave_spinning = 1;
293 ret = btrfs_insert_empty_item(trans, root, path, &key,
294 ins_len);
295 if (ret == -EEXIST) {
296 if (btrfs_find_name_in_ext_backref(path, ref_objectid,
297 name, name_len, NULL))
298 goto out;
299
300 btrfs_extend_item(root, path, ins_len);
301 ret = 0;
302 }
303 if (ret < 0)
304 goto out;
305
306 leaf = path->nodes[0];
307 item = btrfs_item_nr(path->slots[0]);
308 ptr = (unsigned long)btrfs_item_ptr(leaf, path->slots[0], char);
309 ptr += btrfs_item_size(leaf, item) - ins_len;
310 extref = (struct btrfs_inode_extref *)ptr;
311
312 btrfs_set_inode_extref_name_len(path->nodes[0], extref, name_len);
313 btrfs_set_inode_extref_index(path->nodes[0], extref, index);
314 btrfs_set_inode_extref_parent(path->nodes[0], extref, ref_objectid);
315
316 ptr = (unsigned long)&extref->name;
317 write_extent_buffer(path->nodes[0], name, ptr, name_len);
318 btrfs_mark_buffer_dirty(path->nodes[0]);
319
320out:
321 btrfs_free_path(path);
322 return ret;
323}
324
325/* Will return 0, -ENOMEM, -EMLINK, or -EEXIST or anything from the CoW path */
326int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans,
327 struct btrfs_root *root,
328 const char *name, int name_len,
329 u64 inode_objectid, u64 ref_objectid, u64 index)
330{
331 struct btrfs_path *path;
332 struct btrfs_key key;
333 struct btrfs_inode_ref *ref;
334 unsigned long ptr;
335 int ret;
336 int ins_len = name_len + sizeof(*ref);
337
338 key.objectid = inode_objectid;
339 key.offset = ref_objectid;
340 btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY);
341
342 path = btrfs_alloc_path();
343 if (!path)
344 return -ENOMEM;
345
346 path->leave_spinning = 1;
347 ret = btrfs_insert_empty_item(trans, root, path, &key,
348 ins_len);
349 if (ret == -EEXIST) {
350 u32 old_size;
351
352 if (find_name_in_backref(path, name, name_len, &ref))
353 goto out;
354
355 old_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
356 btrfs_extend_item(root, path, ins_len);
357 ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
358 struct btrfs_inode_ref);
359 ref = (struct btrfs_inode_ref *)((unsigned long)ref + old_size);
360 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
361 btrfs_set_inode_ref_index(path->nodes[0], ref, index);
362 ptr = (unsigned long)(ref + 1);
363 ret = 0;
364 } else if (ret < 0) {
365 if (ret == -EOVERFLOW)
366 ret = -EMLINK;
367 goto out;
368 } else {
369 ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
370 struct btrfs_inode_ref);
371 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
372 btrfs_set_inode_ref_index(path->nodes[0], ref, index);
373 ptr = (unsigned long)(ref + 1);
374 }
375 write_extent_buffer(path->nodes[0], name, ptr, name_len);
376 btrfs_mark_buffer_dirty(path->nodes[0]);
377
378out:
379 btrfs_free_path(path);
380
381 if (ret == -EMLINK) {
382 struct btrfs_super_block *disk_super = root->fs_info->super_copy;
383 /* We ran out of space in the ref array. Need to
384 * add an extended ref. */
385 if (btrfs_super_incompat_flags(disk_super)
386 & BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF)
387 ret = btrfs_insert_inode_extref(trans, root, name,
388 name_len,
389 inode_objectid,
390 ref_objectid, index);
391 }
392
393 return ret;
394}
395
396int btrfs_insert_empty_inode(struct btrfs_trans_handle *trans,
397 struct btrfs_root *root,
398 struct btrfs_path *path, u64 objectid)
399{
400 struct btrfs_key key;
401 int ret;
402 key.objectid = objectid;
403 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
404 key.offset = 0;
405
406 ret = btrfs_insert_empty_item(trans, root, path, &key,
407 sizeof(struct btrfs_inode_item));
408 return ret;
409}
410
411int btrfs_lookup_inode(struct btrfs_trans_handle *trans, struct btrfs_root
412 *root, struct btrfs_path *path,
413 struct btrfs_key *location, int mod)
414{
415 int ins_len = mod < 0 ? -1 : 0;
416 int cow = mod != 0;
417 int ret;
418 int slot;
419 struct extent_buffer *leaf;
420 struct btrfs_key found_key;
421
422 ret = btrfs_search_slot(trans, root, location, path, ins_len, cow);
423 if (ret > 0 && btrfs_key_type(location) == BTRFS_ROOT_ITEM_KEY &&
424 location->offset == (u64)-1 && path->slots[0] != 0) {
425 slot = path->slots[0] - 1;
426 leaf = path->nodes[0];
427 btrfs_item_key_to_cpu(leaf, &found_key, slot);
428 if (found_key.objectid == location->objectid &&
429 btrfs_key_type(&found_key) == btrfs_key_type(location)) {
430 path->slots[0]--;
431 return 0;
432 }
433 }
434 return ret;
435}