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Chris Mason6cbd5572007-06-12 09:07:21 -04001/*
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
Chris Mason1e1d2702007-03-15 19:03:33 -040019#include "ctree.h"
20#include "disk-io.h"
Mark Fashehf1863732012-08-08 11:32:27 -070021#include "hash.h"
Chris Masone089f052007-03-16 16:20:31 -040022#include "transaction.h"
Chris Mason727011e2010-08-06 13:21:20 -040023#include "print-tree.h"
Chris Mason1e1d2702007-03-15 19:03:33 -040024
Christoph Hellwigb2950862008-12-02 09:54:17 -050025static int find_name_in_backref(struct btrfs_path *path, const char *name,
Chris Mason39544012007-12-12 14:38:19 -050026 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
Mark Fashehf1863732012-08-08 11:32:27 -070054int 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)
Yan, Zhenga22285a2010-05-16 10:48:46 -040057{
Mark Fashehf1863732012-08-08 11:32:27 -070058 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
Mark Fashehf1863732012-08-08 11:32:27 -070094/* 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
Eric Sandeen48a3b632013-04-25 20:41:01 +0000121static 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)
Chris Mason39544012007-12-12 14:38:19 -0500126{
127 struct btrfs_path *path;
128 struct btrfs_key key;
Mark Fashehf1863732012-08-08 11:32:27 -0700129 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;
David Sterba962a2982014-06-04 18:41:45 +0200138 key.type = BTRFS_INODE_EXTREF_KEY;
Mark Fashehf1863732012-08-08 11:32:27 -0700139 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)) {
Anand Jaina4553fe2015-09-25 14:43:01 +0800160 btrfs_std_error(root->fs_info, -ENOENT, NULL);
Mark Fashehf1863732012-08-08 11:32:27 -0700161 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
Tsutomu Itohafe5fea2013-04-16 05:18:22 +0000185 btrfs_truncate_item(root, path, item_size - del_len, 1);
Mark Fashehf1863732012-08-08 11:32:27 -0700186
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;
Chris Mason39544012007-12-12 14:38:19 -0500200 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;
Mark Fashehf1863732012-08-08 11:32:27 -0700207 int search_ext_refs = 0;
Chris Mason39544012007-12-12 14:38:19 -0500208 int del_len = name_len + sizeof(*ref);
209
210 key.objectid = inode_objectid;
211 key.offset = ref_objectid;
David Sterba962a2982014-06-04 18:41:45 +0200212 key.type = BTRFS_INODE_REF_KEY;
Chris Mason39544012007-12-12 14:38:19 -0500213
214 path = btrfs_alloc_path();
215 if (!path)
216 return -ENOMEM;
217
Chris Masonb9473432009-03-13 11:00:37 -0400218 path->leave_spinning = 1;
219
Chris Mason39544012007-12-12 14:38:19 -0500220 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
221 if (ret > 0) {
222 ret = -ENOENT;
Mark Fashehf1863732012-08-08 11:32:27 -0700223 search_ext_refs = 1;
Chris Mason39544012007-12-12 14:38:19 -0500224 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;
Mark Fashehf1863732012-08-08 11:32:27 -0700230 search_ext_refs = 1;
Chris Mason39544012007-12-12 14:38:19 -0500231 goto out;
232 }
233 leaf = path->nodes[0];
234 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
Josef Bacikaec74772008-07-24 12:12:38 -0400235
236 if (index)
237 *index = btrfs_inode_ref_index(leaf, ref);
238
Chris Mason39544012007-12-12 14:38:19 -0500239 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));
Tsutomu Itohafe5fea2013-04-16 05:18:22 +0000248 btrfs_truncate_item(root, path, item_size - sub_item_len, 1);
Mark Fashehf1863732012-08-08 11:32:27 -0700249out:
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
Tsutomu Itoh4b90c682013-04-16 05:18:49 +0000300 btrfs_extend_item(root, path, ins_len);
Mark Fashehf1863732012-08-08 11:32:27 -0700301 ret = 0;
302 }
303 if (ret < 0)
304 goto out;
305
306 leaf = path->nodes[0];
Ross Kirkdd3cc162013-09-16 15:58:09 +0100307 item = btrfs_item_nr(path->slots[0]);
Mark Fashehf1863732012-08-08 11:32:27 -0700308 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
Chris Mason39544012007-12-12 14:38:19 -0500320out:
321 btrfs_free_path(path);
322 return ret;
323}
324
Jeff Mahoney79787ea2012-03-12 16:03:00 +0100325/* Will return 0, -ENOMEM, -EMLINK, or -EEXIST or anything from the CoW path */
Chris Mason39544012007-12-12 14:38:19 -0500326int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans,
327 struct btrfs_root *root,
328 const char *name, int name_len,
Josef Bacikaec74772008-07-24 12:12:38 -0400329 u64 inode_objectid, u64 ref_objectid, u64 index)
Chris Mason39544012007-12-12 14:38:19 -0500330{
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;
David Sterba962a2982014-06-04 18:41:45 +0200340 key.type = BTRFS_INODE_REF_KEY;
Chris Mason39544012007-12-12 14:38:19 -0500341
342 path = btrfs_alloc_path();
343 if (!path)
344 return -ENOMEM;
345
Chris Masonb9473432009-03-13 11:00:37 -0400346 path->leave_spinning = 1;
Filipe Mananadf8d1162015-01-14 01:52:25 +0000347 path->skip_release_on_error = 1;
Chris Mason39544012007-12-12 14:38:19 -0500348 ret = btrfs_insert_empty_item(trans, root, path, &key,
349 ins_len);
350 if (ret == -EEXIST) {
351 u32 old_size;
352
353 if (find_name_in_backref(path, name, name_len, &ref))
354 goto out;
355
356 old_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
Tsutomu Itoh4b90c682013-04-16 05:18:49 +0000357 btrfs_extend_item(root, path, ins_len);
Chris Mason39544012007-12-12 14:38:19 -0500358 ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
359 struct btrfs_inode_ref);
360 ref = (struct btrfs_inode_ref *)((unsigned long)ref + old_size);
361 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
Josef Bacikaec74772008-07-24 12:12:38 -0400362 btrfs_set_inode_ref_index(path->nodes[0], ref, index);
Chris Mason39544012007-12-12 14:38:19 -0500363 ptr = (unsigned long)(ref + 1);
364 ret = 0;
365 } else if (ret < 0) {
Filipe Mananadf8d1162015-01-14 01:52:25 +0000366 if (ret == -EOVERFLOW) {
367 if (find_name_in_backref(path, name, name_len, &ref))
368 ret = -EEXIST;
369 else
370 ret = -EMLINK;
371 }
Chris Mason39544012007-12-12 14:38:19 -0500372 goto out;
373 } else {
374 ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
375 struct btrfs_inode_ref);
376 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
Josef Bacikaec74772008-07-24 12:12:38 -0400377 btrfs_set_inode_ref_index(path->nodes[0], ref, index);
Chris Mason39544012007-12-12 14:38:19 -0500378 ptr = (unsigned long)(ref + 1);
379 }
380 write_extent_buffer(path->nodes[0], name, ptr, name_len);
381 btrfs_mark_buffer_dirty(path->nodes[0]);
382
383out:
384 btrfs_free_path(path);
Mark Fashehf1863732012-08-08 11:32:27 -0700385
386 if (ret == -EMLINK) {
387 struct btrfs_super_block *disk_super = root->fs_info->super_copy;
388 /* We ran out of space in the ref array. Need to
389 * add an extended ref. */
390 if (btrfs_super_incompat_flags(disk_super)
391 & BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF)
392 ret = btrfs_insert_inode_extref(trans, root, name,
393 name_len,
394 inode_objectid,
395 ref_objectid, index);
396 }
397
Chris Mason39544012007-12-12 14:38:19 -0500398 return ret;
399}
400
Chris Mason5f39d392007-10-15 16:14:19 -0400401int btrfs_insert_empty_inode(struct btrfs_trans_handle *trans,
402 struct btrfs_root *root,
403 struct btrfs_path *path, u64 objectid)
Chris Mason1e1d2702007-03-15 19:03:33 -0400404{
Chris Mason1e1d2702007-03-15 19:03:33 -0400405 struct btrfs_key key;
406 int ret;
407 key.objectid = objectid;
David Sterba962a2982014-06-04 18:41:45 +0200408 key.type = BTRFS_INODE_ITEM_KEY;
Chris Mason1e1d2702007-03-15 19:03:33 -0400409 key.offset = 0;
410
Chris Mason5f39d392007-10-15 16:14:19 -0400411 ret = btrfs_insert_empty_item(trans, root, path, &key,
412 sizeof(struct btrfs_inode_item));
Chris Mason1e1d2702007-03-15 19:03:33 -0400413 return ret;
414}
415
Chris Masone089f052007-03-16 16:20:31 -0400416int btrfs_lookup_inode(struct btrfs_trans_handle *trans, struct btrfs_root
Chris Masond6e4a422007-04-06 15:37:36 -0400417 *root, struct btrfs_path *path,
418 struct btrfs_key *location, int mod)
Chris Mason1e1d2702007-03-15 19:03:33 -0400419{
Chris Mason1e1d2702007-03-15 19:03:33 -0400420 int ins_len = mod < 0 ? -1 : 0;
421 int cow = mod != 0;
Chris Masond6e4a422007-04-06 15:37:36 -0400422 int ret;
423 int slot;
Chris Mason5f39d392007-10-15 16:14:19 -0400424 struct extent_buffer *leaf;
Chris Masond6e4a422007-04-06 15:37:36 -0400425 struct btrfs_key found_key;
Chris Mason1e1d2702007-03-15 19:03:33 -0400426
Chris Masond6e4a422007-04-06 15:37:36 -0400427 ret = btrfs_search_slot(trans, root, location, path, ins_len, cow);
David Sterba962a2982014-06-04 18:41:45 +0200428 if (ret > 0 && location->type == BTRFS_ROOT_ITEM_KEY &&
Chris Masond6e4a422007-04-06 15:37:36 -0400429 location->offset == (u64)-1 && path->slots[0] != 0) {
430 slot = path->slots[0] - 1;
Chris Mason5f39d392007-10-15 16:14:19 -0400431 leaf = path->nodes[0];
432 btrfs_item_key_to_cpu(leaf, &found_key, slot);
Chris Masond6e4a422007-04-06 15:37:36 -0400433 if (found_key.objectid == location->objectid &&
David Sterba962a2982014-06-04 18:41:45 +0200434 found_key.type == location->type) {
Chris Masond6e4a422007-04-06 15:37:36 -0400435 path->slots[0]--;
436 return 0;
437 }
438 }
439 return ret;
Chris Mason1e1d2702007-03-15 19:03:33 -0400440}