blob: 54a201dac7f9455bd1e294c2731d5b47226b7bef [file] [log] [blame]
Jan Schmidta542ad12011-06-13 19:52:59 +02001/*
2 * Copyright (C) 2011 STRATO. 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
Liu Bo425d17a2012-09-07 20:01:30 -060019#include <linux/vmalloc.h>
Jan Schmidta542ad12011-06-13 19:52:59 +020020#include "ctree.h"
21#include "disk-io.h"
22#include "backref.h"
Jan Schmidt8da6d582011-11-23 18:55:04 +010023#include "ulist.h"
24#include "transaction.h"
25#include "delayed-ref.h"
Jan Schmidtb916a592012-04-13 12:28:08 +020026#include "locking.h"
Jan Schmidta542ad12011-06-13 19:52:59 +020027
Jan Schmidt976b1902012-05-17 16:43:03 +020028struct extent_inode_elem {
29 u64 inum;
30 u64 offset;
31 struct extent_inode_elem *next;
32};
33
34static int check_extent_in_eb(struct btrfs_key *key, struct extent_buffer *eb,
35 struct btrfs_file_extent_item *fi,
36 u64 extent_item_pos,
37 struct extent_inode_elem **eie)
38{
Josef Bacik8ca15e02013-07-05 13:58:19 -040039 u64 offset = 0;
Jan Schmidt976b1902012-05-17 16:43:03 +020040 struct extent_inode_elem *e;
41
Josef Bacik8ca15e02013-07-05 13:58:19 -040042 if (!btrfs_file_extent_compression(eb, fi) &&
43 !btrfs_file_extent_encryption(eb, fi) &&
44 !btrfs_file_extent_other_encoding(eb, fi)) {
45 u64 data_offset;
46 u64 data_len;
Jan Schmidt976b1902012-05-17 16:43:03 +020047
Josef Bacik8ca15e02013-07-05 13:58:19 -040048 data_offset = btrfs_file_extent_offset(eb, fi);
49 data_len = btrfs_file_extent_num_bytes(eb, fi);
50
51 if (extent_item_pos < data_offset ||
52 extent_item_pos >= data_offset + data_len)
53 return 1;
54 offset = extent_item_pos - data_offset;
55 }
Jan Schmidt976b1902012-05-17 16:43:03 +020056
57 e = kmalloc(sizeof(*e), GFP_NOFS);
58 if (!e)
59 return -ENOMEM;
60
61 e->next = *eie;
62 e->inum = key->objectid;
Josef Bacik8ca15e02013-07-05 13:58:19 -040063 e->offset = key->offset + offset;
Jan Schmidt976b1902012-05-17 16:43:03 +020064 *eie = e;
65
66 return 0;
67}
68
Wang Shilongf05c4742014-01-28 19:13:38 +080069static void free_inode_elem_list(struct extent_inode_elem *eie)
70{
71 struct extent_inode_elem *eie_next;
72
73 for (; eie; eie = eie_next) {
74 eie_next = eie->next;
75 kfree(eie);
76 }
77}
78
Jan Schmidt976b1902012-05-17 16:43:03 +020079static int find_extent_in_eb(struct extent_buffer *eb, u64 wanted_disk_byte,
80 u64 extent_item_pos,
81 struct extent_inode_elem **eie)
82{
83 u64 disk_byte;
84 struct btrfs_key key;
85 struct btrfs_file_extent_item *fi;
86 int slot;
87 int nritems;
88 int extent_type;
89 int ret;
90
91 /*
92 * from the shared data ref, we only have the leaf but we need
93 * the key. thus, we must look into all items and see that we
94 * find one (some) with a reference to our extent item.
95 */
96 nritems = btrfs_header_nritems(eb);
97 for (slot = 0; slot < nritems; ++slot) {
98 btrfs_item_key_to_cpu(eb, &key, slot);
99 if (key.type != BTRFS_EXTENT_DATA_KEY)
100 continue;
101 fi = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);
102 extent_type = btrfs_file_extent_type(eb, fi);
103 if (extent_type == BTRFS_FILE_EXTENT_INLINE)
104 continue;
105 /* don't skip BTRFS_FILE_EXTENT_PREALLOC, we can handle that */
106 disk_byte = btrfs_file_extent_disk_bytenr(eb, fi);
107 if (disk_byte != wanted_disk_byte)
108 continue;
109
110 ret = check_extent_in_eb(&key, eb, fi, extent_item_pos, eie);
111 if (ret < 0)
112 return ret;
113 }
114
115 return 0;
116}
117
Jan Schmidt8da6d582011-11-23 18:55:04 +0100118/*
119 * this structure records all encountered refs on the way up to the root
120 */
121struct __prelim_ref {
122 struct list_head list;
123 u64 root_id;
Jan Schmidtd5c88b72012-05-15 17:55:51 +0200124 struct btrfs_key key_for_search;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100125 int level;
126 int count;
Jan Schmidt33019582012-05-30 18:05:21 +0200127 struct extent_inode_elem *inode_list;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100128 u64 parent;
129 u64 wanted_disk_byte;
130};
131
Wang Shilongb9e9a6c2013-08-09 13:25:36 +0800132static struct kmem_cache *btrfs_prelim_ref_cache;
133
134int __init btrfs_prelim_ref_init(void)
135{
136 btrfs_prelim_ref_cache = kmem_cache_create("btrfs_prelim_ref",
137 sizeof(struct __prelim_ref),
138 0,
139 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
140 NULL);
141 if (!btrfs_prelim_ref_cache)
142 return -ENOMEM;
143 return 0;
144}
145
146void btrfs_prelim_ref_exit(void)
147{
148 if (btrfs_prelim_ref_cache)
149 kmem_cache_destroy(btrfs_prelim_ref_cache);
150}
151
Jan Schmidtd5c88b72012-05-15 17:55:51 +0200152/*
153 * the rules for all callers of this function are:
154 * - obtaining the parent is the goal
155 * - if you add a key, you must know that it is a correct key
156 * - if you cannot add the parent or a correct key, then we will look into the
157 * block later to set a correct key
158 *
159 * delayed refs
160 * ============
161 * backref type | shared | indirect | shared | indirect
162 * information | tree | tree | data | data
163 * --------------------+--------+----------+--------+----------
164 * parent logical | y | - | - | -
165 * key to resolve | - | y | y | y
166 * tree block logical | - | - | - | -
167 * root for resolving | y | y | y | y
168 *
169 * - column 1: we've the parent -> done
170 * - column 2, 3, 4: we use the key to find the parent
171 *
172 * on disk refs (inline or keyed)
173 * ==============================
174 * backref type | shared | indirect | shared | indirect
175 * information | tree | tree | data | data
176 * --------------------+--------+----------+--------+----------
177 * parent logical | y | - | y | -
178 * key to resolve | - | - | - | y
179 * tree block logical | y | y | y | y
180 * root for resolving | - | y | y | y
181 *
182 * - column 1, 3: we've the parent -> done
183 * - column 2: we take the first key from the block to find the parent
184 * (see __add_missing_keys)
185 * - column 4: we use the key to find the parent
186 *
187 * additional information that's available but not required to find the parent
188 * block might help in merging entries to gain some speed.
189 */
190
Jan Schmidt8da6d582011-11-23 18:55:04 +0100191static int __add_prelim_ref(struct list_head *head, u64 root_id,
Jan Schmidtd5c88b72012-05-15 17:55:51 +0200192 struct btrfs_key *key, int level,
Wang Shilong742916b2013-08-06 10:29:54 +0800193 u64 parent, u64 wanted_disk_byte, int count,
194 gfp_t gfp_mask)
Jan Schmidt8da6d582011-11-23 18:55:04 +0100195{
196 struct __prelim_ref *ref;
197
Liu Bo48ec4732013-10-30 13:25:24 +0800198 if (root_id == BTRFS_DATA_RELOC_TREE_OBJECTID)
199 return 0;
200
Wang Shilongb9e9a6c2013-08-09 13:25:36 +0800201 ref = kmem_cache_alloc(btrfs_prelim_ref_cache, gfp_mask);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100202 if (!ref)
203 return -ENOMEM;
204
205 ref->root_id = root_id;
206 if (key)
Jan Schmidtd5c88b72012-05-15 17:55:51 +0200207 ref->key_for_search = *key;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100208 else
Jan Schmidtd5c88b72012-05-15 17:55:51 +0200209 memset(&ref->key_for_search, 0, sizeof(ref->key_for_search));
Jan Schmidt8da6d582011-11-23 18:55:04 +0100210
Jan Schmidt33019582012-05-30 18:05:21 +0200211 ref->inode_list = NULL;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100212 ref->level = level;
213 ref->count = count;
214 ref->parent = parent;
215 ref->wanted_disk_byte = wanted_disk_byte;
216 list_add_tail(&ref->list, head);
217
218 return 0;
219}
220
221static int add_all_parents(struct btrfs_root *root, struct btrfs_path *path,
Josef Bacik7ef81ac2014-01-24 14:05:42 -0500222 struct ulist *parents, struct __prelim_ref *ref,
Josef Bacik44853862014-03-19 13:35:14 -0400223 int level, u64 time_seq, const u64 *extent_item_pos,
224 u64 total_refs)
Jan Schmidt8da6d582011-11-23 18:55:04 +0100225{
Alexander Block69bca402012-06-19 07:42:26 -0600226 int ret = 0;
227 int slot;
228 struct extent_buffer *eb;
229 struct btrfs_key key;
Josef Bacik7ef81ac2014-01-24 14:05:42 -0500230 struct btrfs_key *key_for_search = &ref->key_for_search;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100231 struct btrfs_file_extent_item *fi;
Josef Baciked8c4912013-07-05 14:03:47 -0400232 struct extent_inode_elem *eie = NULL, *old = NULL;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100233 u64 disk_byte;
Josef Bacik7ef81ac2014-01-24 14:05:42 -0500234 u64 wanted_disk_byte = ref->wanted_disk_byte;
235 u64 count = 0;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100236
Alexander Block69bca402012-06-19 07:42:26 -0600237 if (level != 0) {
238 eb = path->nodes[level];
239 ret = ulist_add(parents, eb->start, 0, GFP_NOFS);
Jan Schmidt33019582012-05-30 18:05:21 +0200240 if (ret < 0)
241 return ret;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100242 return 0;
Alexander Block69bca402012-06-19 07:42:26 -0600243 }
Jan Schmidt8da6d582011-11-23 18:55:04 +0100244
245 /*
Alexander Block69bca402012-06-19 07:42:26 -0600246 * We normally enter this function with the path already pointing to
247 * the first item to check. But sometimes, we may enter it with
248 * slot==nritems. In that case, go to the next leaf before we continue.
Jan Schmidt8da6d582011-11-23 18:55:04 +0100249 */
Alexander Block69bca402012-06-19 07:42:26 -0600250 if (path->slots[0] >= btrfs_header_nritems(path->nodes[0]))
Jan Schmidt3d7806e2012-06-11 08:29:29 +0200251 ret = btrfs_next_old_leaf(root, path, time_seq);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100252
Josef Bacik44853862014-03-19 13:35:14 -0400253 while (!ret && count < total_refs) {
Jan Schmidt8da6d582011-11-23 18:55:04 +0100254 eb = path->nodes[0];
Alexander Block69bca402012-06-19 07:42:26 -0600255 slot = path->slots[0];
256
257 btrfs_item_key_to_cpu(eb, &key, slot);
258
259 if (key.objectid != key_for_search->objectid ||
260 key.type != BTRFS_EXTENT_DATA_KEY)
261 break;
262
263 fi = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);
264 disk_byte = btrfs_file_extent_disk_bytenr(eb, fi);
265
266 if (disk_byte == wanted_disk_byte) {
267 eie = NULL;
Josef Baciked8c4912013-07-05 14:03:47 -0400268 old = NULL;
Josef Bacik7ef81ac2014-01-24 14:05:42 -0500269 count++;
Alexander Block69bca402012-06-19 07:42:26 -0600270 if (extent_item_pos) {
271 ret = check_extent_in_eb(&key, eb, fi,
272 *extent_item_pos,
273 &eie);
274 if (ret < 0)
275 break;
276 }
Josef Baciked8c4912013-07-05 14:03:47 -0400277 if (ret > 0)
278 goto next;
Takashi Iwai4eb1f662014-07-28 10:57:04 +0200279 ret = ulist_add_merge_ptr(parents, eb->start,
280 eie, (void **)&old, GFP_NOFS);
Josef Baciked8c4912013-07-05 14:03:47 -0400281 if (ret < 0)
282 break;
283 if (!ret && extent_item_pos) {
284 while (old->next)
285 old = old->next;
286 old->next = eie;
Alexander Block69bca402012-06-19 07:42:26 -0600287 }
Wang Shilongf05c4742014-01-28 19:13:38 +0800288 eie = NULL;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100289 }
Josef Baciked8c4912013-07-05 14:03:47 -0400290next:
Alexander Block69bca402012-06-19 07:42:26 -0600291 ret = btrfs_next_old_item(root, path, time_seq);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100292 }
293
Alexander Block69bca402012-06-19 07:42:26 -0600294 if (ret > 0)
295 ret = 0;
Wang Shilongf05c4742014-01-28 19:13:38 +0800296 else if (ret < 0)
297 free_inode_elem_list(eie);
Alexander Block69bca402012-06-19 07:42:26 -0600298 return ret;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100299}
300
301/*
302 * resolve an indirect backref in the form (root_id, key, level)
303 * to a logical address
304 */
305static int __resolve_indirect_ref(struct btrfs_fs_info *fs_info,
Josef Bacikda61d312013-06-12 16:20:08 -0400306 struct btrfs_path *path, u64 time_seq,
307 struct __prelim_ref *ref,
308 struct ulist *parents,
Josef Bacik44853862014-03-19 13:35:14 -0400309 const u64 *extent_item_pos, u64 total_refs)
Jan Schmidt8da6d582011-11-23 18:55:04 +0100310{
Jan Schmidt8da6d582011-11-23 18:55:04 +0100311 struct btrfs_root *root;
312 struct btrfs_key root_key;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100313 struct extent_buffer *eb;
314 int ret = 0;
315 int root_level;
316 int level = ref->level;
Wang Shilong538f72cd2014-01-23 13:47:48 +0800317 int index;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100318
Jan Schmidt8da6d582011-11-23 18:55:04 +0100319 root_key.objectid = ref->root_id;
320 root_key.type = BTRFS_ROOT_ITEM_KEY;
321 root_key.offset = (u64)-1;
Wang Shilong538f72cd2014-01-23 13:47:48 +0800322
323 index = srcu_read_lock(&fs_info->subvol_srcu);
324
Jan Schmidt8da6d582011-11-23 18:55:04 +0100325 root = btrfs_read_fs_root_no_name(fs_info, &root_key);
326 if (IS_ERR(root)) {
Wang Shilong538f72cd2014-01-23 13:47:48 +0800327 srcu_read_unlock(&fs_info->subvol_srcu, index);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100328 ret = PTR_ERR(root);
329 goto out;
330 }
331
Josef Bacik9e351cc2014-03-13 15:42:13 -0400332 if (path->search_commit_root)
333 root_level = btrfs_header_level(root->commit_root);
334 else
335 root_level = btrfs_old_root_level(root, time_seq);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100336
Wang Shilong538f72cd2014-01-23 13:47:48 +0800337 if (root_level + 1 == level) {
338 srcu_read_unlock(&fs_info->subvol_srcu, index);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100339 goto out;
Wang Shilong538f72cd2014-01-23 13:47:48 +0800340 }
Jan Schmidt8da6d582011-11-23 18:55:04 +0100341
342 path->lowest_level = level;
Jan Schmidt8445f612012-05-16 18:36:03 +0200343 ret = btrfs_search_old_slot(root, &ref->key_for_search, path, time_seq);
Wang Shilong538f72cd2014-01-23 13:47:48 +0800344
345 /* root node has been locked, we can release @subvol_srcu safely here */
346 srcu_read_unlock(&fs_info->subvol_srcu, index);
347
Jan Schmidt8da6d582011-11-23 18:55:04 +0100348 pr_debug("search slot in root %llu (level %d, ref count %d) returned "
349 "%d for key (%llu %u %llu)\n",
Geert Uytterhoevenc1c9ff72013-08-20 13:20:07 +0200350 ref->root_id, level, ref->count, ret,
351 ref->key_for_search.objectid, ref->key_for_search.type,
352 ref->key_for_search.offset);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100353 if (ret < 0)
354 goto out;
355
356 eb = path->nodes[level];
Jan Schmidt93454572012-06-27 15:23:09 +0200357 while (!eb) {
Dulshani Gunawardhanafae7f212013-10-31 10:30:08 +0530358 if (WARN_ON(!level)) {
Jan Schmidt93454572012-06-27 15:23:09 +0200359 ret = 1;
360 goto out;
361 }
362 level--;
363 eb = path->nodes[level];
Jan Schmidt8da6d582011-11-23 18:55:04 +0100364 }
365
Josef Bacik7ef81ac2014-01-24 14:05:42 -0500366 ret = add_all_parents(root, path, parents, ref, level, time_seq,
Josef Bacik44853862014-03-19 13:35:14 -0400367 extent_item_pos, total_refs);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100368out:
Josef Bacikda61d312013-06-12 16:20:08 -0400369 path->lowest_level = 0;
370 btrfs_release_path(path);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100371 return ret;
372}
373
374/*
375 * resolve all indirect backrefs from the list
376 */
377static int __resolve_indirect_refs(struct btrfs_fs_info *fs_info,
Josef Bacikda61d312013-06-12 16:20:08 -0400378 struct btrfs_path *path, u64 time_seq,
Jan Schmidt976b1902012-05-17 16:43:03 +0200379 struct list_head *head,
Josef Bacik44853862014-03-19 13:35:14 -0400380 const u64 *extent_item_pos, u64 total_refs)
Jan Schmidt8da6d582011-11-23 18:55:04 +0100381{
382 int err;
383 int ret = 0;
384 struct __prelim_ref *ref;
385 struct __prelim_ref *ref_safe;
386 struct __prelim_ref *new_ref;
387 struct ulist *parents;
388 struct ulist_node *node;
Jan Schmidtcd1b4132012-05-22 14:56:50 +0200389 struct ulist_iterator uiter;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100390
391 parents = ulist_alloc(GFP_NOFS);
392 if (!parents)
393 return -ENOMEM;
394
395 /*
396 * _safe allows us to insert directly after the current item without
397 * iterating over the newly inserted items.
398 * we're also allowed to re-assign ref during iteration.
399 */
400 list_for_each_entry_safe(ref, ref_safe, head, list) {
401 if (ref->parent) /* already direct */
402 continue;
403 if (ref->count == 0)
404 continue;
Josef Bacikda61d312013-06-12 16:20:08 -0400405 err = __resolve_indirect_ref(fs_info, path, time_seq, ref,
Josef Bacik44853862014-03-19 13:35:14 -0400406 parents, extent_item_pos,
407 total_refs);
Wang Shilong95def2ed2014-01-23 13:47:49 +0800408 /*
409 * we can only tolerate ENOENT,otherwise,we should catch error
410 * and return directly.
411 */
412 if (err == -ENOENT) {
Jan Schmidt8da6d582011-11-23 18:55:04 +0100413 continue;
Wang Shilong95def2ed2014-01-23 13:47:49 +0800414 } else if (err) {
415 ret = err;
416 goto out;
417 }
Jan Schmidt8da6d582011-11-23 18:55:04 +0100418
419 /* we put the first parent into the ref at hand */
Jan Schmidtcd1b4132012-05-22 14:56:50 +0200420 ULIST_ITER_INIT(&uiter);
421 node = ulist_next(parents, &uiter);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100422 ref->parent = node ? node->val : 0;
Jan Schmidt995e01b2012-08-13 02:52:38 -0600423 ref->inode_list = node ?
Stefan Behrens35a36212013-08-14 18:12:25 +0200424 (struct extent_inode_elem *)(uintptr_t)node->aux : NULL;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100425
426 /* additional parents require new refs being added here */
Jan Schmidtcd1b4132012-05-22 14:56:50 +0200427 while ((node = ulist_next(parents, &uiter))) {
Wang Shilongb9e9a6c2013-08-09 13:25:36 +0800428 new_ref = kmem_cache_alloc(btrfs_prelim_ref_cache,
429 GFP_NOFS);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100430 if (!new_ref) {
431 ret = -ENOMEM;
Wang Shilonge36902d2013-04-15 10:26:38 +0000432 goto out;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100433 }
434 memcpy(new_ref, ref, sizeof(*ref));
435 new_ref->parent = node->val;
Jan Schmidt995e01b2012-08-13 02:52:38 -0600436 new_ref->inode_list = (struct extent_inode_elem *)
437 (uintptr_t)node->aux;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100438 list_add(&new_ref->list, &ref->list);
439 }
440 ulist_reinit(parents);
441 }
Wang Shilonge36902d2013-04-15 10:26:38 +0000442out:
Jan Schmidt8da6d582011-11-23 18:55:04 +0100443 ulist_free(parents);
444 return ret;
445}
446
Jan Schmidtd5c88b72012-05-15 17:55:51 +0200447static inline int ref_for_same_block(struct __prelim_ref *ref1,
448 struct __prelim_ref *ref2)
449{
450 if (ref1->level != ref2->level)
451 return 0;
452 if (ref1->root_id != ref2->root_id)
453 return 0;
454 if (ref1->key_for_search.type != ref2->key_for_search.type)
455 return 0;
456 if (ref1->key_for_search.objectid != ref2->key_for_search.objectid)
457 return 0;
458 if (ref1->key_for_search.offset != ref2->key_for_search.offset)
459 return 0;
460 if (ref1->parent != ref2->parent)
461 return 0;
462
463 return 1;
464}
465
466/*
467 * read tree blocks and add keys where required.
468 */
469static int __add_missing_keys(struct btrfs_fs_info *fs_info,
470 struct list_head *head)
471{
472 struct list_head *pos;
473 struct extent_buffer *eb;
474
475 list_for_each(pos, head) {
476 struct __prelim_ref *ref;
477 ref = list_entry(pos, struct __prelim_ref, list);
478
479 if (ref->parent)
480 continue;
481 if (ref->key_for_search.type)
482 continue;
483 BUG_ON(!ref->wanted_disk_byte);
484 eb = read_tree_block(fs_info->tree_root, ref->wanted_disk_byte,
485 fs_info->tree_root->leafsize, 0);
Josef Bacik416bc652013-04-23 14:17:42 -0400486 if (!eb || !extent_buffer_uptodate(eb)) {
487 free_extent_buffer(eb);
488 return -EIO;
489 }
Jan Schmidtd5c88b72012-05-15 17:55:51 +0200490 btrfs_tree_read_lock(eb);
491 if (btrfs_header_level(eb) == 0)
492 btrfs_item_key_to_cpu(eb, &ref->key_for_search, 0);
493 else
494 btrfs_node_key_to_cpu(eb, &ref->key_for_search, 0);
495 btrfs_tree_read_unlock(eb);
496 free_extent_buffer(eb);
497 }
498 return 0;
499}
500
Jan Schmidt8da6d582011-11-23 18:55:04 +0100501/*
502 * merge two lists of backrefs and adjust counts accordingly
503 *
504 * mode = 1: merge identical keys, if key is set
Jan Schmidtd5c88b72012-05-15 17:55:51 +0200505 * FIXME: if we add more keys in __add_prelim_ref, we can merge more here.
506 * additionally, we could even add a key range for the blocks we
507 * looked into to merge even more (-> replace unresolved refs by those
508 * having a parent).
Jan Schmidt8da6d582011-11-23 18:55:04 +0100509 * mode = 2: merge identical parents
510 */
Wang Shilong692206b2013-04-11 07:08:55 +0000511static void __merge_refs(struct list_head *head, int mode)
Jan Schmidt8da6d582011-11-23 18:55:04 +0100512{
513 struct list_head *pos1;
514
515 list_for_each(pos1, head) {
516 struct list_head *n2;
517 struct list_head *pos2;
518 struct __prelim_ref *ref1;
519
520 ref1 = list_entry(pos1, struct __prelim_ref, list);
521
Jan Schmidt8da6d582011-11-23 18:55:04 +0100522 for (pos2 = pos1->next, n2 = pos2->next; pos2 != head;
523 pos2 = n2, n2 = pos2->next) {
524 struct __prelim_ref *ref2;
Jan Schmidtd5c88b72012-05-15 17:55:51 +0200525 struct __prelim_ref *xchg;
Alexander Block3ef59692012-11-08 21:27:24 +0000526 struct extent_inode_elem *eie;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100527
528 ref2 = list_entry(pos2, struct __prelim_ref, list);
529
530 if (mode == 1) {
Jan Schmidtd5c88b72012-05-15 17:55:51 +0200531 if (!ref_for_same_block(ref1, ref2))
Jan Schmidt8da6d582011-11-23 18:55:04 +0100532 continue;
Jan Schmidtd5c88b72012-05-15 17:55:51 +0200533 if (!ref1->parent && ref2->parent) {
534 xchg = ref1;
535 ref1 = ref2;
536 ref2 = xchg;
537 }
Jan Schmidt8da6d582011-11-23 18:55:04 +0100538 } else {
539 if (ref1->parent != ref2->parent)
540 continue;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100541 }
Alexander Block3ef59692012-11-08 21:27:24 +0000542
543 eie = ref1->inode_list;
544 while (eie && eie->next)
545 eie = eie->next;
546 if (eie)
547 eie->next = ref2->inode_list;
548 else
549 ref1->inode_list = ref2->inode_list;
550 ref1->count += ref2->count;
551
Jan Schmidt8da6d582011-11-23 18:55:04 +0100552 list_del(&ref2->list);
Wang Shilongb9e9a6c2013-08-09 13:25:36 +0800553 kmem_cache_free(btrfs_prelim_ref_cache, ref2);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100554 }
555
556 }
Jan Schmidt8da6d582011-11-23 18:55:04 +0100557}
558
559/*
560 * add all currently queued delayed refs from this head whose seq nr is
561 * smaller or equal that seq to the list
562 */
563static int __add_delayed_refs(struct btrfs_delayed_ref_head *head, u64 seq,
Josef Bacik44853862014-03-19 13:35:14 -0400564 struct list_head *prefs, u64 *total_refs)
Jan Schmidt8da6d582011-11-23 18:55:04 +0100565{
566 struct btrfs_delayed_extent_op *extent_op = head->extent_op;
567 struct rb_node *n = &head->node.rb_node;
Jan Schmidtd5c88b72012-05-15 17:55:51 +0200568 struct btrfs_key key;
569 struct btrfs_key op_key = {0};
Jan Schmidt8da6d582011-11-23 18:55:04 +0100570 int sgn;
Jan Schmidtb1375d62012-01-26 15:01:11 -0500571 int ret = 0;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100572
573 if (extent_op && extent_op->update_key)
Jan Schmidtd5c88b72012-05-15 17:55:51 +0200574 btrfs_disk_key_to_cpu(&op_key, &extent_op->key);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100575
Josef Bacikd7df2c72014-01-23 09:21:38 -0500576 spin_lock(&head->lock);
577 n = rb_first(&head->ref_root);
578 while (n) {
Jan Schmidt8da6d582011-11-23 18:55:04 +0100579 struct btrfs_delayed_ref_node *node;
580 node = rb_entry(n, struct btrfs_delayed_ref_node,
581 rb_node);
Josef Bacikd7df2c72014-01-23 09:21:38 -0500582 n = rb_next(n);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100583 if (node->seq > seq)
584 continue;
585
586 switch (node->action) {
587 case BTRFS_ADD_DELAYED_EXTENT:
588 case BTRFS_UPDATE_DELAYED_HEAD:
589 WARN_ON(1);
590 continue;
591 case BTRFS_ADD_DELAYED_REF:
592 sgn = 1;
593 break;
594 case BTRFS_DROP_DELAYED_REF:
595 sgn = -1;
596 break;
597 default:
598 BUG_ON(1);
599 }
Josef Bacik44853862014-03-19 13:35:14 -0400600 *total_refs += (node->ref_mod * sgn);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100601 switch (node->type) {
602 case BTRFS_TREE_BLOCK_REF_KEY: {
603 struct btrfs_delayed_tree_ref *ref;
604
605 ref = btrfs_delayed_node_to_tree_ref(node);
Jan Schmidtd5c88b72012-05-15 17:55:51 +0200606 ret = __add_prelim_ref(prefs, ref->root, &op_key,
Jan Schmidt8da6d582011-11-23 18:55:04 +0100607 ref->level + 1, 0, node->bytenr,
Wang Shilong742916b2013-08-06 10:29:54 +0800608 node->ref_mod * sgn, GFP_ATOMIC);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100609 break;
610 }
611 case BTRFS_SHARED_BLOCK_REF_KEY: {
612 struct btrfs_delayed_tree_ref *ref;
613
614 ref = btrfs_delayed_node_to_tree_ref(node);
Jan Schmidtd5c88b72012-05-15 17:55:51 +0200615 ret = __add_prelim_ref(prefs, ref->root, NULL,
Jan Schmidt8da6d582011-11-23 18:55:04 +0100616 ref->level + 1, ref->parent,
617 node->bytenr,
Wang Shilong742916b2013-08-06 10:29:54 +0800618 node->ref_mod * sgn, GFP_ATOMIC);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100619 break;
620 }
621 case BTRFS_EXTENT_DATA_REF_KEY: {
622 struct btrfs_delayed_data_ref *ref;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100623 ref = btrfs_delayed_node_to_data_ref(node);
624
625 key.objectid = ref->objectid;
626 key.type = BTRFS_EXTENT_DATA_KEY;
627 key.offset = ref->offset;
628 ret = __add_prelim_ref(prefs, ref->root, &key, 0, 0,
629 node->bytenr,
Wang Shilong742916b2013-08-06 10:29:54 +0800630 node->ref_mod * sgn, GFP_ATOMIC);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100631 break;
632 }
633 case BTRFS_SHARED_DATA_REF_KEY: {
634 struct btrfs_delayed_data_ref *ref;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100635
636 ref = btrfs_delayed_node_to_data_ref(node);
637
638 key.objectid = ref->objectid;
639 key.type = BTRFS_EXTENT_DATA_KEY;
640 key.offset = ref->offset;
641 ret = __add_prelim_ref(prefs, ref->root, &key, 0,
642 ref->parent, node->bytenr,
Wang Shilong742916b2013-08-06 10:29:54 +0800643 node->ref_mod * sgn, GFP_ATOMIC);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100644 break;
645 }
646 default:
647 WARN_ON(1);
648 }
Wang Shilong1149ab62013-04-10 11:22:50 +0000649 if (ret)
Josef Bacikd7df2c72014-01-23 09:21:38 -0500650 break;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100651 }
Josef Bacikd7df2c72014-01-23 09:21:38 -0500652 spin_unlock(&head->lock);
653 return ret;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100654}
655
656/*
657 * add all inline backrefs for bytenr to the list
658 */
659static int __add_inline_refs(struct btrfs_fs_info *fs_info,
660 struct btrfs_path *path, u64 bytenr,
Josef Bacik44853862014-03-19 13:35:14 -0400661 int *info_level, struct list_head *prefs,
662 u64 *total_refs)
Jan Schmidt8da6d582011-11-23 18:55:04 +0100663{
Jan Schmidtb1375d62012-01-26 15:01:11 -0500664 int ret = 0;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100665 int slot;
666 struct extent_buffer *leaf;
667 struct btrfs_key key;
Josef Bacik261c84b2013-06-28 13:11:22 -0400668 struct btrfs_key found_key;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100669 unsigned long ptr;
670 unsigned long end;
671 struct btrfs_extent_item *ei;
672 u64 flags;
673 u64 item_size;
674
675 /*
676 * enumerate all inline refs
677 */
678 leaf = path->nodes[0];
Jan Schmidtdadcaf72012-05-22 13:43:25 +0200679 slot = path->slots[0];
Jan Schmidt8da6d582011-11-23 18:55:04 +0100680
681 item_size = btrfs_item_size_nr(leaf, slot);
682 BUG_ON(item_size < sizeof(*ei));
683
684 ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item);
685 flags = btrfs_extent_flags(leaf, ei);
Josef Bacik44853862014-03-19 13:35:14 -0400686 *total_refs += btrfs_extent_refs(leaf, ei);
Josef Bacik261c84b2013-06-28 13:11:22 -0400687 btrfs_item_key_to_cpu(leaf, &found_key, slot);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100688
689 ptr = (unsigned long)(ei + 1);
690 end = (unsigned long)ei + item_size;
691
Josef Bacik261c84b2013-06-28 13:11:22 -0400692 if (found_key.type == BTRFS_EXTENT_ITEM_KEY &&
693 flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
Jan Schmidt8da6d582011-11-23 18:55:04 +0100694 struct btrfs_tree_block_info *info;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100695
696 info = (struct btrfs_tree_block_info *)ptr;
697 *info_level = btrfs_tree_block_level(leaf, info);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100698 ptr += sizeof(struct btrfs_tree_block_info);
699 BUG_ON(ptr > end);
Josef Bacik261c84b2013-06-28 13:11:22 -0400700 } else if (found_key.type == BTRFS_METADATA_ITEM_KEY) {
701 *info_level = found_key.offset;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100702 } else {
703 BUG_ON(!(flags & BTRFS_EXTENT_FLAG_DATA));
704 }
705
706 while (ptr < end) {
707 struct btrfs_extent_inline_ref *iref;
708 u64 offset;
709 int type;
710
711 iref = (struct btrfs_extent_inline_ref *)ptr;
712 type = btrfs_extent_inline_ref_type(leaf, iref);
713 offset = btrfs_extent_inline_ref_offset(leaf, iref);
714
715 switch (type) {
716 case BTRFS_SHARED_BLOCK_REF_KEY:
Jan Schmidtd5c88b72012-05-15 17:55:51 +0200717 ret = __add_prelim_ref(prefs, 0, NULL,
Jan Schmidt8da6d582011-11-23 18:55:04 +0100718 *info_level + 1, offset,
Wang Shilong742916b2013-08-06 10:29:54 +0800719 bytenr, 1, GFP_NOFS);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100720 break;
721 case BTRFS_SHARED_DATA_REF_KEY: {
722 struct btrfs_shared_data_ref *sdref;
723 int count;
724
725 sdref = (struct btrfs_shared_data_ref *)(iref + 1);
726 count = btrfs_shared_data_ref_count(leaf, sdref);
727 ret = __add_prelim_ref(prefs, 0, NULL, 0, offset,
Wang Shilong742916b2013-08-06 10:29:54 +0800728 bytenr, count, GFP_NOFS);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100729 break;
730 }
731 case BTRFS_TREE_BLOCK_REF_KEY:
Jan Schmidtd5c88b72012-05-15 17:55:51 +0200732 ret = __add_prelim_ref(prefs, offset, NULL,
733 *info_level + 1, 0,
Wang Shilong742916b2013-08-06 10:29:54 +0800734 bytenr, 1, GFP_NOFS);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100735 break;
736 case BTRFS_EXTENT_DATA_REF_KEY: {
737 struct btrfs_extent_data_ref *dref;
738 int count;
739 u64 root;
740
741 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
742 count = btrfs_extent_data_ref_count(leaf, dref);
743 key.objectid = btrfs_extent_data_ref_objectid(leaf,
744 dref);
745 key.type = BTRFS_EXTENT_DATA_KEY;
746 key.offset = btrfs_extent_data_ref_offset(leaf, dref);
747 root = btrfs_extent_data_ref_root(leaf, dref);
Jan Schmidtd5c88b72012-05-15 17:55:51 +0200748 ret = __add_prelim_ref(prefs, root, &key, 0, 0,
Wang Shilong742916b2013-08-06 10:29:54 +0800749 bytenr, count, GFP_NOFS);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100750 break;
751 }
752 default:
753 WARN_ON(1);
754 }
Wang Shilong1149ab62013-04-10 11:22:50 +0000755 if (ret)
756 return ret;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100757 ptr += btrfs_extent_inline_ref_size(type);
758 }
759
760 return 0;
761}
762
763/*
764 * add all non-inline backrefs for bytenr to the list
765 */
766static int __add_keyed_refs(struct btrfs_fs_info *fs_info,
767 struct btrfs_path *path, u64 bytenr,
Jan Schmidtd5c88b72012-05-15 17:55:51 +0200768 int info_level, struct list_head *prefs)
Jan Schmidt8da6d582011-11-23 18:55:04 +0100769{
770 struct btrfs_root *extent_root = fs_info->extent_root;
771 int ret;
772 int slot;
773 struct extent_buffer *leaf;
774 struct btrfs_key key;
775
776 while (1) {
777 ret = btrfs_next_item(extent_root, path);
778 if (ret < 0)
779 break;
780 if (ret) {
781 ret = 0;
782 break;
783 }
784
785 slot = path->slots[0];
786 leaf = path->nodes[0];
787 btrfs_item_key_to_cpu(leaf, &key, slot);
788
789 if (key.objectid != bytenr)
790 break;
791 if (key.type < BTRFS_TREE_BLOCK_REF_KEY)
792 continue;
793 if (key.type > BTRFS_SHARED_DATA_REF_KEY)
794 break;
795
796 switch (key.type) {
797 case BTRFS_SHARED_BLOCK_REF_KEY:
Jan Schmidtd5c88b72012-05-15 17:55:51 +0200798 ret = __add_prelim_ref(prefs, 0, NULL,
Jan Schmidt8da6d582011-11-23 18:55:04 +0100799 info_level + 1, key.offset,
Wang Shilong742916b2013-08-06 10:29:54 +0800800 bytenr, 1, GFP_NOFS);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100801 break;
802 case BTRFS_SHARED_DATA_REF_KEY: {
803 struct btrfs_shared_data_ref *sdref;
804 int count;
805
806 sdref = btrfs_item_ptr(leaf, slot,
807 struct btrfs_shared_data_ref);
808 count = btrfs_shared_data_ref_count(leaf, sdref);
809 ret = __add_prelim_ref(prefs, 0, NULL, 0, key.offset,
Wang Shilong742916b2013-08-06 10:29:54 +0800810 bytenr, count, GFP_NOFS);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100811 break;
812 }
813 case BTRFS_TREE_BLOCK_REF_KEY:
Jan Schmidtd5c88b72012-05-15 17:55:51 +0200814 ret = __add_prelim_ref(prefs, key.offset, NULL,
815 info_level + 1, 0,
Wang Shilong742916b2013-08-06 10:29:54 +0800816 bytenr, 1, GFP_NOFS);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100817 break;
818 case BTRFS_EXTENT_DATA_REF_KEY: {
819 struct btrfs_extent_data_ref *dref;
820 int count;
821 u64 root;
822
823 dref = btrfs_item_ptr(leaf, slot,
824 struct btrfs_extent_data_ref);
825 count = btrfs_extent_data_ref_count(leaf, dref);
826 key.objectid = btrfs_extent_data_ref_objectid(leaf,
827 dref);
828 key.type = BTRFS_EXTENT_DATA_KEY;
829 key.offset = btrfs_extent_data_ref_offset(leaf, dref);
830 root = btrfs_extent_data_ref_root(leaf, dref);
831 ret = __add_prelim_ref(prefs, root, &key, 0, 0,
Wang Shilong742916b2013-08-06 10:29:54 +0800832 bytenr, count, GFP_NOFS);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100833 break;
834 }
835 default:
836 WARN_ON(1);
837 }
Wang Shilong1149ab62013-04-10 11:22:50 +0000838 if (ret)
839 return ret;
840
Jan Schmidt8da6d582011-11-23 18:55:04 +0100841 }
842
843 return ret;
844}
845
846/*
847 * this adds all existing backrefs (inline backrefs, backrefs and delayed
848 * refs) for the given bytenr to the refs list, merges duplicates and resolves
849 * indirect refs to their parent bytenr.
850 * When roots are found, they're added to the roots list
851 *
852 * FIXME some caching might speed things up
853 */
854static int find_parent_nodes(struct btrfs_trans_handle *trans,
855 struct btrfs_fs_info *fs_info, u64 bytenr,
Jan Schmidt097b8a72012-06-21 11:08:04 +0200856 u64 time_seq, struct ulist *refs,
857 struct ulist *roots, const u64 *extent_item_pos)
Jan Schmidt8da6d582011-11-23 18:55:04 +0100858{
859 struct btrfs_key key;
860 struct btrfs_path *path;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100861 struct btrfs_delayed_ref_root *delayed_refs = NULL;
Li Zefand3b01062012-03-03 07:41:15 -0500862 struct btrfs_delayed_ref_head *head;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100863 int info_level = 0;
864 int ret;
865 struct list_head prefs_delayed;
866 struct list_head prefs;
867 struct __prelim_ref *ref;
Wang Shilongf05c4742014-01-28 19:13:38 +0800868 struct extent_inode_elem *eie = NULL;
Josef Bacik44853862014-03-19 13:35:14 -0400869 u64 total_refs = 0;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100870
871 INIT_LIST_HEAD(&prefs);
872 INIT_LIST_HEAD(&prefs_delayed);
873
874 key.objectid = bytenr;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100875 key.offset = (u64)-1;
Josef Bacik261c84b2013-06-28 13:11:22 -0400876 if (btrfs_fs_incompat(fs_info, SKINNY_METADATA))
877 key.type = BTRFS_METADATA_ITEM_KEY;
878 else
879 key.type = BTRFS_EXTENT_ITEM_KEY;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100880
881 path = btrfs_alloc_path();
882 if (!path)
883 return -ENOMEM;
Wang Shilonge84752d2014-02-13 11:19:47 +0800884 if (!trans) {
Josef Bacikda61d312013-06-12 16:20:08 -0400885 path->search_commit_root = 1;
Wang Shilonge84752d2014-02-13 11:19:47 +0800886 path->skip_locking = 1;
887 }
Jan Schmidt8da6d582011-11-23 18:55:04 +0100888
889 /*
890 * grab both a lock on the path and a lock on the delayed ref head.
891 * We need both to get a consistent picture of how the refs look
892 * at a specified point in time
893 */
894again:
Li Zefand3b01062012-03-03 07:41:15 -0500895 head = NULL;
896
Jan Schmidt8da6d582011-11-23 18:55:04 +0100897 ret = btrfs_search_slot(trans, fs_info->extent_root, &key, path, 0, 0);
898 if (ret < 0)
899 goto out;
900 BUG_ON(ret == 0);
901
Josef Bacikfaa2dbf2014-05-07 17:06:09 -0400902#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
903 if (trans && likely(trans->type != __TRANS_DUMMY)) {
904#else
Josef Bacikda61d312013-06-12 16:20:08 -0400905 if (trans) {
Josef Bacikfaa2dbf2014-05-07 17:06:09 -0400906#endif
Jan Schmidt7a3ae2f2012-03-23 17:32:28 +0100907 /*
908 * look if there are updates for this ref queued and lock the
909 * head
910 */
911 delayed_refs = &trans->transaction->delayed_refs;
912 spin_lock(&delayed_refs->lock);
913 head = btrfs_find_delayed_ref_head(trans, bytenr);
914 if (head) {
915 if (!mutex_trylock(&head->mutex)) {
916 atomic_inc(&head->node.refs);
917 spin_unlock(&delayed_refs->lock);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100918
Jan Schmidt7a3ae2f2012-03-23 17:32:28 +0100919 btrfs_release_path(path);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100920
Jan Schmidt7a3ae2f2012-03-23 17:32:28 +0100921 /*
922 * Mutex was contended, block until it's
923 * released and try again
924 */
925 mutex_lock(&head->mutex);
926 mutex_unlock(&head->mutex);
927 btrfs_put_delayed_ref(&head->node);
928 goto again;
929 }
Josef Bacikd7df2c72014-01-23 09:21:38 -0500930 spin_unlock(&delayed_refs->lock);
Jan Schmidt097b8a72012-06-21 11:08:04 +0200931 ret = __add_delayed_refs(head, time_seq,
Josef Bacik44853862014-03-19 13:35:14 -0400932 &prefs_delayed, &total_refs);
Jan Schmidt155725c2012-06-22 14:01:00 +0200933 mutex_unlock(&head->mutex);
Josef Bacikd7df2c72014-01-23 09:21:38 -0500934 if (ret)
Jan Schmidt7a3ae2f2012-03-23 17:32:28 +0100935 goto out;
Josef Bacikd7df2c72014-01-23 09:21:38 -0500936 } else {
937 spin_unlock(&delayed_refs->lock);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100938 }
Jan Schmidt8da6d582011-11-23 18:55:04 +0100939 }
Jan Schmidt8da6d582011-11-23 18:55:04 +0100940
941 if (path->slots[0]) {
942 struct extent_buffer *leaf;
943 int slot;
944
Jan Schmidtdadcaf72012-05-22 13:43:25 +0200945 path->slots[0]--;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100946 leaf = path->nodes[0];
Jan Schmidtdadcaf72012-05-22 13:43:25 +0200947 slot = path->slots[0];
Jan Schmidt8da6d582011-11-23 18:55:04 +0100948 btrfs_item_key_to_cpu(leaf, &key, slot);
949 if (key.objectid == bytenr &&
Josef Bacik261c84b2013-06-28 13:11:22 -0400950 (key.type == BTRFS_EXTENT_ITEM_KEY ||
951 key.type == BTRFS_METADATA_ITEM_KEY)) {
Jan Schmidt8da6d582011-11-23 18:55:04 +0100952 ret = __add_inline_refs(fs_info, path, bytenr,
Josef Bacik44853862014-03-19 13:35:14 -0400953 &info_level, &prefs,
954 &total_refs);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100955 if (ret)
956 goto out;
Jan Schmidtd5c88b72012-05-15 17:55:51 +0200957 ret = __add_keyed_refs(fs_info, path, bytenr,
Jan Schmidt8da6d582011-11-23 18:55:04 +0100958 info_level, &prefs);
959 if (ret)
960 goto out;
961 }
962 }
963 btrfs_release_path(path);
964
Jan Schmidt8da6d582011-11-23 18:55:04 +0100965 list_splice_init(&prefs_delayed, &prefs);
966
Jan Schmidtd5c88b72012-05-15 17:55:51 +0200967 ret = __add_missing_keys(fs_info, &prefs);
968 if (ret)
969 goto out;
970
Wang Shilong692206b2013-04-11 07:08:55 +0000971 __merge_refs(&prefs, 1);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100972
Josef Bacikda61d312013-06-12 16:20:08 -0400973 ret = __resolve_indirect_refs(fs_info, path, time_seq, &prefs,
Josef Bacik44853862014-03-19 13:35:14 -0400974 extent_item_pos, total_refs);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100975 if (ret)
976 goto out;
977
Wang Shilong692206b2013-04-11 07:08:55 +0000978 __merge_refs(&prefs, 2);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100979
980 while (!list_empty(&prefs)) {
981 ref = list_first_entry(&prefs, struct __prelim_ref, list);
Julia Lawall6c1500f2012-11-03 20:30:18 +0000982 WARN_ON(ref->count < 0);
Wang Shilong98cfee212014-02-01 00:42:05 +0800983 if (roots && ref->count && ref->root_id && ref->parent == 0) {
Jan Schmidt8da6d582011-11-23 18:55:04 +0100984 /* no parent == root of tree */
985 ret = ulist_add(roots, ref->root_id, 0, GFP_NOFS);
Wang Shilongf1723932013-03-29 23:03:21 +0000986 if (ret < 0)
987 goto out;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100988 }
989 if (ref->count && ref->parent) {
Josef Bacik8a564572014-06-05 16:08:45 -0400990 if (extent_item_pos && !ref->inode_list &&
991 ref->level == 0) {
Jan Schmidt976b1902012-05-17 16:43:03 +0200992 u32 bsz;
993 struct extent_buffer *eb;
994 bsz = btrfs_level_size(fs_info->extent_root,
Josef Bacik8a564572014-06-05 16:08:45 -0400995 ref->level);
Jan Schmidt976b1902012-05-17 16:43:03 +0200996 eb = read_tree_block(fs_info->extent_root,
997 ref->parent, bsz, 0);
Josef Bacik416bc652013-04-23 14:17:42 -0400998 if (!eb || !extent_buffer_uptodate(eb)) {
999 free_extent_buffer(eb);
Wang Shilongc16c2e22013-05-08 08:10:25 +00001000 ret = -EIO;
1001 goto out;
Josef Bacik416bc652013-04-23 14:17:42 -04001002 }
Filipe Manana6f7ff6d2014-07-02 20:07:54 +01001003 btrfs_tree_read_lock(eb);
1004 btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK);
Jan Schmidt976b1902012-05-17 16:43:03 +02001005 ret = find_extent_in_eb(eb, bytenr,
1006 *extent_item_pos, &eie);
Filipe Manana6f7ff6d2014-07-02 20:07:54 +01001007 btrfs_tree_read_unlock_blocking(eb);
Jan Schmidt976b1902012-05-17 16:43:03 +02001008 free_extent_buffer(eb);
Filipe David Borba Mananaf5929cd2013-07-31 00:26:35 +01001009 if (ret < 0)
1010 goto out;
1011 ref->inode_list = eie;
Jan Schmidt976b1902012-05-17 16:43:03 +02001012 }
Takashi Iwai4eb1f662014-07-28 10:57:04 +02001013 ret = ulist_add_merge_ptr(refs, ref->parent,
1014 ref->inode_list,
1015 (void **)&eie, GFP_NOFS);
Wang Shilongf1723932013-03-29 23:03:21 +00001016 if (ret < 0)
1017 goto out;
Jan Schmidt33019582012-05-30 18:05:21 +02001018 if (!ret && extent_item_pos) {
1019 /*
1020 * we've recorded that parent, so we must extend
1021 * its inode list here
1022 */
1023 BUG_ON(!eie);
1024 while (eie->next)
1025 eie = eie->next;
1026 eie->next = ref->inode_list;
1027 }
Wang Shilongf05c4742014-01-28 19:13:38 +08001028 eie = NULL;
Jan Schmidt8da6d582011-11-23 18:55:04 +01001029 }
Wang Shilonga4fdb612013-08-08 13:04:17 +08001030 list_del(&ref->list);
Wang Shilongb9e9a6c2013-08-09 13:25:36 +08001031 kmem_cache_free(btrfs_prelim_ref_cache, ref);
Jan Schmidt8da6d582011-11-23 18:55:04 +01001032 }
1033
1034out:
Jan Schmidt8da6d582011-11-23 18:55:04 +01001035 btrfs_free_path(path);
1036 while (!list_empty(&prefs)) {
1037 ref = list_first_entry(&prefs, struct __prelim_ref, list);
1038 list_del(&ref->list);
Wang Shilongb9e9a6c2013-08-09 13:25:36 +08001039 kmem_cache_free(btrfs_prelim_ref_cache, ref);
Jan Schmidt8da6d582011-11-23 18:55:04 +01001040 }
1041 while (!list_empty(&prefs_delayed)) {
1042 ref = list_first_entry(&prefs_delayed, struct __prelim_ref,
1043 list);
1044 list_del(&ref->list);
Wang Shilongb9e9a6c2013-08-09 13:25:36 +08001045 kmem_cache_free(btrfs_prelim_ref_cache, ref);
Jan Schmidt8da6d582011-11-23 18:55:04 +01001046 }
Wang Shilongf05c4742014-01-28 19:13:38 +08001047 if (ret < 0)
1048 free_inode_elem_list(eie);
Jan Schmidt8da6d582011-11-23 18:55:04 +01001049 return ret;
1050}
1051
Jan Schmidt976b1902012-05-17 16:43:03 +02001052static void free_leaf_list(struct ulist *blocks)
1053{
1054 struct ulist_node *node = NULL;
1055 struct extent_inode_elem *eie;
Jan Schmidt976b1902012-05-17 16:43:03 +02001056 struct ulist_iterator uiter;
1057
1058 ULIST_ITER_INIT(&uiter);
1059 while ((node = ulist_next(blocks, &uiter))) {
1060 if (!node->aux)
1061 continue;
Jan Schmidt995e01b2012-08-13 02:52:38 -06001062 eie = (struct extent_inode_elem *)(uintptr_t)node->aux;
Wang Shilongf05c4742014-01-28 19:13:38 +08001063 free_inode_elem_list(eie);
Jan Schmidt976b1902012-05-17 16:43:03 +02001064 node->aux = 0;
1065 }
1066
1067 ulist_free(blocks);
1068}
1069
Jan Schmidt8da6d582011-11-23 18:55:04 +01001070/*
1071 * Finds all leafs with a reference to the specified combination of bytenr and
1072 * offset. key_list_head will point to a list of corresponding keys (caller must
1073 * free each list element). The leafs will be stored in the leafs ulist, which
1074 * must be freed with ulist_free.
1075 *
1076 * returns 0 on success, <0 on error
1077 */
1078static int btrfs_find_all_leafs(struct btrfs_trans_handle *trans,
1079 struct btrfs_fs_info *fs_info, u64 bytenr,
Jan Schmidt097b8a72012-06-21 11:08:04 +02001080 u64 time_seq, struct ulist **leafs,
Jan Schmidt976b1902012-05-17 16:43:03 +02001081 const u64 *extent_item_pos)
Jan Schmidt8da6d582011-11-23 18:55:04 +01001082{
Jan Schmidt8da6d582011-11-23 18:55:04 +01001083 int ret;
1084
Jan Schmidt8da6d582011-11-23 18:55:04 +01001085 *leafs = ulist_alloc(GFP_NOFS);
Wang Shilong98cfee212014-02-01 00:42:05 +08001086 if (!*leafs)
Jan Schmidt8da6d582011-11-23 18:55:04 +01001087 return -ENOMEM;
Jan Schmidt8da6d582011-11-23 18:55:04 +01001088
Jan Schmidt097b8a72012-06-21 11:08:04 +02001089 ret = find_parent_nodes(trans, fs_info, bytenr,
Wang Shilong98cfee212014-02-01 00:42:05 +08001090 time_seq, *leafs, NULL, extent_item_pos);
Jan Schmidt8da6d582011-11-23 18:55:04 +01001091 if (ret < 0 && ret != -ENOENT) {
Jan Schmidt976b1902012-05-17 16:43:03 +02001092 free_leaf_list(*leafs);
Jan Schmidt8da6d582011-11-23 18:55:04 +01001093 return ret;
1094 }
1095
1096 return 0;
1097}
1098
1099/*
1100 * walk all backrefs for a given extent to find all roots that reference this
1101 * extent. Walking a backref means finding all extents that reference this
1102 * extent and in turn walk the backrefs of those, too. Naturally this is a
1103 * recursive process, but here it is implemented in an iterative fashion: We
1104 * find all referencing extents for the extent in question and put them on a
1105 * list. In turn, we find all referencing extents for those, further appending
1106 * to the list. The way we iterate the list allows adding more elements after
1107 * the current while iterating. The process stops when we reach the end of the
1108 * list. Found roots are added to the roots list.
1109 *
1110 * returns 0 on success, < 0 on error.
1111 */
Josef Bacik9e351cc2014-03-13 15:42:13 -04001112static int __btrfs_find_all_roots(struct btrfs_trans_handle *trans,
1113 struct btrfs_fs_info *fs_info, u64 bytenr,
1114 u64 time_seq, struct ulist **roots)
Jan Schmidt8da6d582011-11-23 18:55:04 +01001115{
1116 struct ulist *tmp;
1117 struct ulist_node *node = NULL;
Jan Schmidtcd1b4132012-05-22 14:56:50 +02001118 struct ulist_iterator uiter;
Jan Schmidt8da6d582011-11-23 18:55:04 +01001119 int ret;
1120
1121 tmp = ulist_alloc(GFP_NOFS);
1122 if (!tmp)
1123 return -ENOMEM;
1124 *roots = ulist_alloc(GFP_NOFS);
1125 if (!*roots) {
1126 ulist_free(tmp);
1127 return -ENOMEM;
1128 }
1129
Jan Schmidtcd1b4132012-05-22 14:56:50 +02001130 ULIST_ITER_INIT(&uiter);
Jan Schmidt8da6d582011-11-23 18:55:04 +01001131 while (1) {
Jan Schmidt097b8a72012-06-21 11:08:04 +02001132 ret = find_parent_nodes(trans, fs_info, bytenr,
Jan Schmidt8445f612012-05-16 18:36:03 +02001133 time_seq, tmp, *roots, NULL);
Jan Schmidt8da6d582011-11-23 18:55:04 +01001134 if (ret < 0 && ret != -ENOENT) {
1135 ulist_free(tmp);
1136 ulist_free(*roots);
1137 return ret;
1138 }
Jan Schmidtcd1b4132012-05-22 14:56:50 +02001139 node = ulist_next(tmp, &uiter);
Jan Schmidt8da6d582011-11-23 18:55:04 +01001140 if (!node)
1141 break;
1142 bytenr = node->val;
Wang Shilongbca1a292014-01-26 22:32:18 +08001143 cond_resched();
Jan Schmidt8da6d582011-11-23 18:55:04 +01001144 }
1145
1146 ulist_free(tmp);
1147 return 0;
1148}
1149
Josef Bacik9e351cc2014-03-13 15:42:13 -04001150int btrfs_find_all_roots(struct btrfs_trans_handle *trans,
1151 struct btrfs_fs_info *fs_info, u64 bytenr,
1152 u64 time_seq, struct ulist **roots)
1153{
1154 int ret;
1155
1156 if (!trans)
1157 down_read(&fs_info->commit_root_sem);
1158 ret = __btrfs_find_all_roots(trans, fs_info, bytenr, time_seq, roots);
1159 if (!trans)
1160 up_read(&fs_info->commit_root_sem);
1161 return ret;
1162}
1163
Jan Schmidta542ad12011-06-13 19:52:59 +02001164/*
1165 * this makes the path point to (inum INODE_ITEM ioff)
1166 */
1167int inode_item_info(u64 inum, u64 ioff, struct btrfs_root *fs_root,
1168 struct btrfs_path *path)
1169{
1170 struct btrfs_key key;
Kelley Nielsene33d5c32013-11-04 19:33:33 -08001171 return btrfs_find_item(fs_root, path, inum, ioff,
1172 BTRFS_INODE_ITEM_KEY, &key);
Jan Schmidta542ad12011-06-13 19:52:59 +02001173}
1174
1175static int inode_ref_info(u64 inum, u64 ioff, struct btrfs_root *fs_root,
1176 struct btrfs_path *path,
1177 struct btrfs_key *found_key)
1178{
Kelley Nielsene33d5c32013-11-04 19:33:33 -08001179 return btrfs_find_item(fs_root, path, inum, ioff,
1180 BTRFS_INODE_REF_KEY, found_key);
Jan Schmidta542ad12011-06-13 19:52:59 +02001181}
1182
Mark Fashehf1863732012-08-08 11:32:27 -07001183int btrfs_find_one_extref(struct btrfs_root *root, u64 inode_objectid,
1184 u64 start_off, struct btrfs_path *path,
1185 struct btrfs_inode_extref **ret_extref,
1186 u64 *found_off)
1187{
1188 int ret, slot;
1189 struct btrfs_key key;
1190 struct btrfs_key found_key;
1191 struct btrfs_inode_extref *extref;
1192 struct extent_buffer *leaf;
1193 unsigned long ptr;
1194
1195 key.objectid = inode_objectid;
1196 btrfs_set_key_type(&key, BTRFS_INODE_EXTREF_KEY);
1197 key.offset = start_off;
1198
1199 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1200 if (ret < 0)
1201 return ret;
1202
1203 while (1) {
1204 leaf = path->nodes[0];
1205 slot = path->slots[0];
1206 if (slot >= btrfs_header_nritems(leaf)) {
1207 /*
1208 * If the item at offset is not found,
1209 * btrfs_search_slot will point us to the slot
1210 * where it should be inserted. In our case
1211 * that will be the slot directly before the
1212 * next INODE_REF_KEY_V2 item. In the case
1213 * that we're pointing to the last slot in a
1214 * leaf, we must move one leaf over.
1215 */
1216 ret = btrfs_next_leaf(root, path);
1217 if (ret) {
1218 if (ret >= 1)
1219 ret = -ENOENT;
1220 break;
1221 }
1222 continue;
1223 }
1224
1225 btrfs_item_key_to_cpu(leaf, &found_key, slot);
1226
1227 /*
1228 * Check that we're still looking at an extended ref key for
1229 * this particular objectid. If we have different
1230 * objectid or type then there are no more to be found
1231 * in the tree and we can exit.
1232 */
1233 ret = -ENOENT;
1234 if (found_key.objectid != inode_objectid)
1235 break;
1236 if (btrfs_key_type(&found_key) != BTRFS_INODE_EXTREF_KEY)
1237 break;
1238
1239 ret = 0;
1240 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
1241 extref = (struct btrfs_inode_extref *)ptr;
1242 *ret_extref = extref;
1243 if (found_off)
1244 *found_off = found_key.offset;
1245 break;
1246 }
1247
1248 return ret;
1249}
1250
Eric Sandeen48a3b632013-04-25 20:41:01 +00001251/*
1252 * this iterates to turn a name (from iref/extref) into a full filesystem path.
1253 * Elements of the path are separated by '/' and the path is guaranteed to be
1254 * 0-terminated. the path is only given within the current file system.
1255 * Therefore, it never starts with a '/'. the caller is responsible to provide
1256 * "size" bytes in "dest". the dest buffer will be filled backwards. finally,
1257 * the start point of the resulting string is returned. this pointer is within
1258 * dest, normally.
1259 * in case the path buffer would overflow, the pointer is decremented further
1260 * as if output was written to the buffer, though no more output is actually
1261 * generated. that way, the caller can determine how much space would be
1262 * required for the path to fit into the buffer. in that case, the returned
1263 * value will be smaller than dest. callers must check this!
1264 */
Jan Schmidt96b5bd72012-10-15 08:30:45 +00001265char *btrfs_ref_to_path(struct btrfs_root *fs_root, struct btrfs_path *path,
1266 u32 name_len, unsigned long name_off,
1267 struct extent_buffer *eb_in, u64 parent,
1268 char *dest, u32 size)
Jan Schmidta542ad12011-06-13 19:52:59 +02001269{
Jan Schmidta542ad12011-06-13 19:52:59 +02001270 int slot;
1271 u64 next_inum;
1272 int ret;
Gabriel de Perthuis661bec62012-10-10 08:50:47 -06001273 s64 bytes_left = ((s64)size) - 1;
Jan Schmidta542ad12011-06-13 19:52:59 +02001274 struct extent_buffer *eb = eb_in;
1275 struct btrfs_key found_key;
Jan Schmidtb916a592012-04-13 12:28:08 +02001276 int leave_spinning = path->leave_spinning;
Mark Fashehd24bec32012-08-08 11:33:54 -07001277 struct btrfs_inode_ref *iref;
Jan Schmidta542ad12011-06-13 19:52:59 +02001278
1279 if (bytes_left >= 0)
1280 dest[bytes_left] = '\0';
1281
Jan Schmidtb916a592012-04-13 12:28:08 +02001282 path->leave_spinning = 1;
Jan Schmidta542ad12011-06-13 19:52:59 +02001283 while (1) {
Mark Fashehd24bec32012-08-08 11:33:54 -07001284 bytes_left -= name_len;
Jan Schmidta542ad12011-06-13 19:52:59 +02001285 if (bytes_left >= 0)
1286 read_extent_buffer(eb, dest + bytes_left,
Mark Fashehd24bec32012-08-08 11:33:54 -07001287 name_off, name_len);
Jan Schmidtb916a592012-04-13 12:28:08 +02001288 if (eb != eb_in) {
1289 btrfs_tree_read_unlock_blocking(eb);
Jan Schmidta542ad12011-06-13 19:52:59 +02001290 free_extent_buffer(eb);
Jan Schmidtb916a592012-04-13 12:28:08 +02001291 }
Jan Schmidta542ad12011-06-13 19:52:59 +02001292 ret = inode_ref_info(parent, 0, fs_root, path, &found_key);
Jan Schmidt8f24b492012-02-08 16:01:01 +01001293 if (ret > 0)
1294 ret = -ENOENT;
Jan Schmidta542ad12011-06-13 19:52:59 +02001295 if (ret)
1296 break;
Mark Fashehd24bec32012-08-08 11:33:54 -07001297
Jan Schmidta542ad12011-06-13 19:52:59 +02001298 next_inum = found_key.offset;
1299
1300 /* regular exit ahead */
1301 if (parent == next_inum)
1302 break;
1303
1304 slot = path->slots[0];
1305 eb = path->nodes[0];
1306 /* make sure we can use eb after releasing the path */
Jan Schmidtb916a592012-04-13 12:28:08 +02001307 if (eb != eb_in) {
Jan Schmidta542ad12011-06-13 19:52:59 +02001308 atomic_inc(&eb->refs);
Jan Schmidtb916a592012-04-13 12:28:08 +02001309 btrfs_tree_read_lock(eb);
1310 btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK);
1311 }
Jan Schmidta542ad12011-06-13 19:52:59 +02001312 btrfs_release_path(path);
Jan Schmidta542ad12011-06-13 19:52:59 +02001313 iref = btrfs_item_ptr(eb, slot, struct btrfs_inode_ref);
Mark Fashehd24bec32012-08-08 11:33:54 -07001314
1315 name_len = btrfs_inode_ref_name_len(eb, iref);
1316 name_off = (unsigned long)(iref + 1);
1317
Jan Schmidta542ad12011-06-13 19:52:59 +02001318 parent = next_inum;
1319 --bytes_left;
1320 if (bytes_left >= 0)
1321 dest[bytes_left] = '/';
1322 }
1323
1324 btrfs_release_path(path);
Jan Schmidtb916a592012-04-13 12:28:08 +02001325 path->leave_spinning = leave_spinning;
Jan Schmidta542ad12011-06-13 19:52:59 +02001326
1327 if (ret)
1328 return ERR_PTR(ret);
1329
1330 return dest + bytes_left;
1331}
1332
1333/*
1334 * this makes the path point to (logical EXTENT_ITEM *)
1335 * returns BTRFS_EXTENT_FLAG_DATA for data, BTRFS_EXTENT_FLAG_TREE_BLOCK for
1336 * tree blocks and <0 on error.
1337 */
1338int extent_from_logical(struct btrfs_fs_info *fs_info, u64 logical,
Liu Bo69917e42012-09-07 20:01:28 -06001339 struct btrfs_path *path, struct btrfs_key *found_key,
1340 u64 *flags_ret)
Jan Schmidta542ad12011-06-13 19:52:59 +02001341{
1342 int ret;
1343 u64 flags;
Josef Bacik261c84b2013-06-28 13:11:22 -04001344 u64 size = 0;
Jan Schmidta542ad12011-06-13 19:52:59 +02001345 u32 item_size;
1346 struct extent_buffer *eb;
1347 struct btrfs_extent_item *ei;
1348 struct btrfs_key key;
1349
Josef Bacik261c84b2013-06-28 13:11:22 -04001350 if (btrfs_fs_incompat(fs_info, SKINNY_METADATA))
1351 key.type = BTRFS_METADATA_ITEM_KEY;
1352 else
1353 key.type = BTRFS_EXTENT_ITEM_KEY;
Jan Schmidta542ad12011-06-13 19:52:59 +02001354 key.objectid = logical;
1355 key.offset = (u64)-1;
1356
1357 ret = btrfs_search_slot(NULL, fs_info->extent_root, &key, path, 0, 0);
1358 if (ret < 0)
1359 return ret;
Jan Schmidta542ad12011-06-13 19:52:59 +02001360
Wang Shilong850a8cd2014-02-06 20:02:29 +08001361 ret = btrfs_previous_extent_item(fs_info->extent_root, path, 0);
1362 if (ret) {
1363 if (ret > 0)
1364 ret = -ENOENT;
1365 return ret;
Josef Bacik580f0a62014-01-23 16:03:45 -05001366 }
Wang Shilong850a8cd2014-02-06 20:02:29 +08001367 btrfs_item_key_to_cpu(path->nodes[0], found_key, path->slots[0]);
Josef Bacik261c84b2013-06-28 13:11:22 -04001368 if (found_key->type == BTRFS_METADATA_ITEM_KEY)
1369 size = fs_info->extent_root->leafsize;
1370 else if (found_key->type == BTRFS_EXTENT_ITEM_KEY)
1371 size = found_key->offset;
1372
Josef Bacik580f0a62014-01-23 16:03:45 -05001373 if (found_key->objectid > logical ||
Josef Bacik261c84b2013-06-28 13:11:22 -04001374 found_key->objectid + size <= logical) {
Geert Uytterhoevenc1c9ff72013-08-20 13:20:07 +02001375 pr_debug("logical %llu is not within any extent\n", logical);
Jan Schmidta542ad12011-06-13 19:52:59 +02001376 return -ENOENT;
Jan Schmidt4692cf52011-12-02 14:56:41 +01001377 }
Jan Schmidta542ad12011-06-13 19:52:59 +02001378
1379 eb = path->nodes[0];
1380 item_size = btrfs_item_size_nr(eb, path->slots[0]);
1381 BUG_ON(item_size < sizeof(*ei));
1382
1383 ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item);
1384 flags = btrfs_extent_flags(eb, ei);
1385
Jan Schmidt4692cf52011-12-02 14:56:41 +01001386 pr_debug("logical %llu is at position %llu within the extent (%llu "
1387 "EXTENT_ITEM %llu) flags %#llx size %u\n",
Geert Uytterhoevenc1c9ff72013-08-20 13:20:07 +02001388 logical, logical - found_key->objectid, found_key->objectid,
1389 found_key->offset, flags, item_size);
Liu Bo69917e42012-09-07 20:01:28 -06001390
1391 WARN_ON(!flags_ret);
1392 if (flags_ret) {
1393 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)
1394 *flags_ret = BTRFS_EXTENT_FLAG_TREE_BLOCK;
1395 else if (flags & BTRFS_EXTENT_FLAG_DATA)
1396 *flags_ret = BTRFS_EXTENT_FLAG_DATA;
1397 else
1398 BUG_ON(1);
1399 return 0;
1400 }
Jan Schmidta542ad12011-06-13 19:52:59 +02001401
1402 return -EIO;
1403}
1404
1405/*
1406 * helper function to iterate extent inline refs. ptr must point to a 0 value
1407 * for the first call and may be modified. it is used to track state.
1408 * if more refs exist, 0 is returned and the next call to
1409 * __get_extent_inline_ref must pass the modified ptr parameter to get the
1410 * next ref. after the last ref was processed, 1 is returned.
1411 * returns <0 on error
1412 */
1413static int __get_extent_inline_ref(unsigned long *ptr, struct extent_buffer *eb,
Liu Bo6eda71d2014-06-09 10:54:07 +08001414 struct btrfs_key *key,
1415 struct btrfs_extent_item *ei, u32 item_size,
1416 struct btrfs_extent_inline_ref **out_eiref,
1417 int *out_type)
Jan Schmidta542ad12011-06-13 19:52:59 +02001418{
1419 unsigned long end;
1420 u64 flags;
1421 struct btrfs_tree_block_info *info;
1422
1423 if (!*ptr) {
1424 /* first call */
1425 flags = btrfs_extent_flags(eb, ei);
1426 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
Liu Bo6eda71d2014-06-09 10:54:07 +08001427 if (key->type == BTRFS_METADATA_ITEM_KEY) {
1428 /* a skinny metadata extent */
1429 *out_eiref =
1430 (struct btrfs_extent_inline_ref *)(ei + 1);
1431 } else {
1432 WARN_ON(key->type != BTRFS_EXTENT_ITEM_KEY);
1433 info = (struct btrfs_tree_block_info *)(ei + 1);
1434 *out_eiref =
1435 (struct btrfs_extent_inline_ref *)(info + 1);
1436 }
Jan Schmidta542ad12011-06-13 19:52:59 +02001437 } else {
1438 *out_eiref = (struct btrfs_extent_inline_ref *)(ei + 1);
1439 }
1440 *ptr = (unsigned long)*out_eiref;
Liu Bocd857dd2014-06-08 19:04:13 +08001441 if ((unsigned long)(*ptr) >= (unsigned long)ei + item_size)
Jan Schmidta542ad12011-06-13 19:52:59 +02001442 return -ENOENT;
1443 }
1444
1445 end = (unsigned long)ei + item_size;
Liu Bo6eda71d2014-06-09 10:54:07 +08001446 *out_eiref = (struct btrfs_extent_inline_ref *)(*ptr);
Jan Schmidta542ad12011-06-13 19:52:59 +02001447 *out_type = btrfs_extent_inline_ref_type(eb, *out_eiref);
1448
1449 *ptr += btrfs_extent_inline_ref_size(*out_type);
1450 WARN_ON(*ptr > end);
1451 if (*ptr == end)
1452 return 1; /* last */
1453
1454 return 0;
1455}
1456
1457/*
1458 * reads the tree block backref for an extent. tree level and root are returned
1459 * through out_level and out_root. ptr must point to a 0 value for the first
1460 * call and may be modified (see __get_extent_inline_ref comment).
1461 * returns 0 if data was provided, 1 if there was no more data to provide or
1462 * <0 on error.
1463 */
1464int tree_backref_for_extent(unsigned long *ptr, struct extent_buffer *eb,
Liu Bo6eda71d2014-06-09 10:54:07 +08001465 struct btrfs_key *key, struct btrfs_extent_item *ei,
1466 u32 item_size, u64 *out_root, u8 *out_level)
Jan Schmidta542ad12011-06-13 19:52:59 +02001467{
1468 int ret;
1469 int type;
1470 struct btrfs_tree_block_info *info;
1471 struct btrfs_extent_inline_ref *eiref;
1472
1473 if (*ptr == (unsigned long)-1)
1474 return 1;
1475
1476 while (1) {
Liu Bo6eda71d2014-06-09 10:54:07 +08001477 ret = __get_extent_inline_ref(ptr, eb, key, ei, item_size,
1478 &eiref, &type);
Jan Schmidta542ad12011-06-13 19:52:59 +02001479 if (ret < 0)
1480 return ret;
1481
1482 if (type == BTRFS_TREE_BLOCK_REF_KEY ||
1483 type == BTRFS_SHARED_BLOCK_REF_KEY)
1484 break;
1485
1486 if (ret == 1)
1487 return 1;
1488 }
1489
1490 /* we can treat both ref types equally here */
1491 info = (struct btrfs_tree_block_info *)(ei + 1);
1492 *out_root = btrfs_extent_inline_ref_offset(eb, eiref);
1493 *out_level = btrfs_tree_block_level(eb, info);
1494
1495 if (ret == 1)
1496 *ptr = (unsigned long)-1;
1497
1498 return 0;
1499}
1500
Jan Schmidt976b1902012-05-17 16:43:03 +02001501static int iterate_leaf_refs(struct extent_inode_elem *inode_list,
1502 u64 root, u64 extent_item_objectid,
Jan Schmidt4692cf52011-12-02 14:56:41 +01001503 iterate_extent_inodes_t *iterate, void *ctx)
Jan Schmidta542ad12011-06-13 19:52:59 +02001504{
Jan Schmidt976b1902012-05-17 16:43:03 +02001505 struct extent_inode_elem *eie;
Jan Schmidt4692cf52011-12-02 14:56:41 +01001506 int ret = 0;
Jan Schmidta542ad12011-06-13 19:52:59 +02001507
Jan Schmidt976b1902012-05-17 16:43:03 +02001508 for (eie = inode_list; eie; eie = eie->next) {
Jan Schmidt4692cf52011-12-02 14:56:41 +01001509 pr_debug("ref for %llu resolved, key (%llu EXTEND_DATA %llu), "
Jan Schmidt976b1902012-05-17 16:43:03 +02001510 "root %llu\n", extent_item_objectid,
1511 eie->inum, eie->offset, root);
1512 ret = iterate(eie->inum, eie->offset, root, ctx);
Jan Schmidt4692cf52011-12-02 14:56:41 +01001513 if (ret) {
Jan Schmidt976b1902012-05-17 16:43:03 +02001514 pr_debug("stopping iteration for %llu due to ret=%d\n",
1515 extent_item_objectid, ret);
Jan Schmidt4692cf52011-12-02 14:56:41 +01001516 break;
1517 }
Jan Schmidta542ad12011-06-13 19:52:59 +02001518 }
1519
Jan Schmidta542ad12011-06-13 19:52:59 +02001520 return ret;
1521}
1522
1523/*
1524 * calls iterate() for every inode that references the extent identified by
Jan Schmidt4692cf52011-12-02 14:56:41 +01001525 * the given parameters.
Jan Schmidta542ad12011-06-13 19:52:59 +02001526 * when the iterator function returns a non-zero value, iteration stops.
1527 */
1528int iterate_extent_inodes(struct btrfs_fs_info *fs_info,
Jan Schmidt4692cf52011-12-02 14:56:41 +01001529 u64 extent_item_objectid, u64 extent_item_pos,
Jan Schmidt7a3ae2f2012-03-23 17:32:28 +01001530 int search_commit_root,
Jan Schmidta542ad12011-06-13 19:52:59 +02001531 iterate_extent_inodes_t *iterate, void *ctx)
1532{
Jan Schmidta542ad12011-06-13 19:52:59 +02001533 int ret;
Josef Bacikda61d312013-06-12 16:20:08 -04001534 struct btrfs_trans_handle *trans = NULL;
Jan Schmidt7a3ae2f2012-03-23 17:32:28 +01001535 struct ulist *refs = NULL;
1536 struct ulist *roots = NULL;
Jan Schmidt4692cf52011-12-02 14:56:41 +01001537 struct ulist_node *ref_node = NULL;
1538 struct ulist_node *root_node = NULL;
Jan Schmidt8445f612012-05-16 18:36:03 +02001539 struct seq_list tree_mod_seq_elem = {};
Jan Schmidtcd1b4132012-05-22 14:56:50 +02001540 struct ulist_iterator ref_uiter;
1541 struct ulist_iterator root_uiter;
Jan Schmidta542ad12011-06-13 19:52:59 +02001542
Jan Schmidt4692cf52011-12-02 14:56:41 +01001543 pr_debug("resolving all inodes for extent %llu\n",
1544 extent_item_objectid);
1545
Josef Bacikda61d312013-06-12 16:20:08 -04001546 if (!search_commit_root) {
Jan Schmidt7a3ae2f2012-03-23 17:32:28 +01001547 trans = btrfs_join_transaction(fs_info->extent_root);
1548 if (IS_ERR(trans))
1549 return PTR_ERR(trans);
Jan Schmidt8445f612012-05-16 18:36:03 +02001550 btrfs_get_tree_mod_seq(fs_info, &tree_mod_seq_elem);
Josef Bacik9e351cc2014-03-13 15:42:13 -04001551 } else {
1552 down_read(&fs_info->commit_root_sem);
Jan Schmidt7a3ae2f2012-03-23 17:32:28 +01001553 }
Jan Schmidt4692cf52011-12-02 14:56:41 +01001554
1555 ret = btrfs_find_all_leafs(trans, fs_info, extent_item_objectid,
Jan Schmidt097b8a72012-06-21 11:08:04 +02001556 tree_mod_seq_elem.seq, &refs,
Jan Schmidt8445f612012-05-16 18:36:03 +02001557 &extent_item_pos);
Jan Schmidt4692cf52011-12-02 14:56:41 +01001558 if (ret)
1559 goto out;
1560
Jan Schmidtcd1b4132012-05-22 14:56:50 +02001561 ULIST_ITER_INIT(&ref_uiter);
1562 while (!ret && (ref_node = ulist_next(refs, &ref_uiter))) {
Josef Bacik9e351cc2014-03-13 15:42:13 -04001563 ret = __btrfs_find_all_roots(trans, fs_info, ref_node->val,
1564 tree_mod_seq_elem.seq, &roots);
Jan Schmidt4692cf52011-12-02 14:56:41 +01001565 if (ret)
Jan Schmidta542ad12011-06-13 19:52:59 +02001566 break;
Jan Schmidtcd1b4132012-05-22 14:56:50 +02001567 ULIST_ITER_INIT(&root_uiter);
1568 while (!ret && (root_node = ulist_next(roots, &root_uiter))) {
Jan Schmidt976b1902012-05-17 16:43:03 +02001569 pr_debug("root %llu references leaf %llu, data list "
Alexander Block34d73f52012-07-28 16:18:58 +02001570 "%#llx\n", root_node->val, ref_node->val,
Geert Uytterhoevenc1c9ff72013-08-20 13:20:07 +02001571 ref_node->aux);
Jan Schmidt995e01b2012-08-13 02:52:38 -06001572 ret = iterate_leaf_refs((struct extent_inode_elem *)
1573 (uintptr_t)ref_node->aux,
1574 root_node->val,
1575 extent_item_objectid,
1576 iterate, ctx);
Jan Schmidta542ad12011-06-13 19:52:59 +02001577 }
Jan Schmidt976b1902012-05-17 16:43:03 +02001578 ulist_free(roots);
Jan Schmidta542ad12011-06-13 19:52:59 +02001579 }
1580
Jan Schmidt976b1902012-05-17 16:43:03 +02001581 free_leaf_list(refs);
Jan Schmidt4692cf52011-12-02 14:56:41 +01001582out:
Jan Schmidt7a3ae2f2012-03-23 17:32:28 +01001583 if (!search_commit_root) {
Jan Schmidt8445f612012-05-16 18:36:03 +02001584 btrfs_put_tree_mod_seq(fs_info, &tree_mod_seq_elem);
Jan Schmidt7a3ae2f2012-03-23 17:32:28 +01001585 btrfs_end_transaction(trans, fs_info->extent_root);
Josef Bacik9e351cc2014-03-13 15:42:13 -04001586 } else {
1587 up_read(&fs_info->commit_root_sem);
Jan Schmidt7a3ae2f2012-03-23 17:32:28 +01001588 }
1589
Jan Schmidta542ad12011-06-13 19:52:59 +02001590 return ret;
1591}
1592
1593int iterate_inodes_from_logical(u64 logical, struct btrfs_fs_info *fs_info,
1594 struct btrfs_path *path,
1595 iterate_extent_inodes_t *iterate, void *ctx)
1596{
1597 int ret;
Jan Schmidt4692cf52011-12-02 14:56:41 +01001598 u64 extent_item_pos;
Liu Bo69917e42012-09-07 20:01:28 -06001599 u64 flags = 0;
Jan Schmidta542ad12011-06-13 19:52:59 +02001600 struct btrfs_key found_key;
Jan Schmidt7a3ae2f2012-03-23 17:32:28 +01001601 int search_commit_root = path->search_commit_root;
Jan Schmidta542ad12011-06-13 19:52:59 +02001602
Liu Bo69917e42012-09-07 20:01:28 -06001603 ret = extent_from_logical(fs_info, logical, path, &found_key, &flags);
Jan Schmidt4692cf52011-12-02 14:56:41 +01001604 btrfs_release_path(path);
Jan Schmidta542ad12011-06-13 19:52:59 +02001605 if (ret < 0)
1606 return ret;
Liu Bo69917e42012-09-07 20:01:28 -06001607 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)
Stefan Behrens3627bf42012-08-01 04:28:01 -06001608 return -EINVAL;
Jan Schmidta542ad12011-06-13 19:52:59 +02001609
Jan Schmidt4692cf52011-12-02 14:56:41 +01001610 extent_item_pos = logical - found_key.objectid;
Jan Schmidt7a3ae2f2012-03-23 17:32:28 +01001611 ret = iterate_extent_inodes(fs_info, found_key.objectid,
1612 extent_item_pos, search_commit_root,
1613 iterate, ctx);
Jan Schmidta542ad12011-06-13 19:52:59 +02001614
1615 return ret;
1616}
1617
Mark Fashehd24bec32012-08-08 11:33:54 -07001618typedef int (iterate_irefs_t)(u64 parent, u32 name_len, unsigned long name_off,
1619 struct extent_buffer *eb, void *ctx);
1620
1621static int iterate_inode_refs(u64 inum, struct btrfs_root *fs_root,
1622 struct btrfs_path *path,
1623 iterate_irefs_t *iterate, void *ctx)
Jan Schmidta542ad12011-06-13 19:52:59 +02001624{
Jan Schmidtaefc1eb2012-04-13 12:28:00 +02001625 int ret = 0;
Jan Schmidta542ad12011-06-13 19:52:59 +02001626 int slot;
1627 u32 cur;
1628 u32 len;
1629 u32 name_len;
1630 u64 parent = 0;
1631 int found = 0;
1632 struct extent_buffer *eb;
1633 struct btrfs_item *item;
1634 struct btrfs_inode_ref *iref;
1635 struct btrfs_key found_key;
1636
Jan Schmidtaefc1eb2012-04-13 12:28:00 +02001637 while (!ret) {
Jan Schmidta542ad12011-06-13 19:52:59 +02001638 ret = inode_ref_info(inum, parent ? parent+1 : 0, fs_root, path,
Mark Fashehd24bec32012-08-08 11:33:54 -07001639 &found_key);
Jan Schmidta542ad12011-06-13 19:52:59 +02001640 if (ret < 0)
1641 break;
1642 if (ret) {
1643 ret = found ? 0 : -ENOENT;
1644 break;
1645 }
1646 ++found;
1647
1648 parent = found_key.offset;
1649 slot = path->slots[0];
Filipe David Borba Manana3fe81ce2013-12-15 12:43:58 +00001650 eb = btrfs_clone_extent_buffer(path->nodes[0]);
1651 if (!eb) {
1652 ret = -ENOMEM;
1653 break;
1654 }
1655 extent_buffer_get(eb);
Jan Schmidtb916a592012-04-13 12:28:08 +02001656 btrfs_tree_read_lock(eb);
1657 btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK);
Jan Schmidta542ad12011-06-13 19:52:59 +02001658 btrfs_release_path(path);
1659
Ross Kirkdd3cc162013-09-16 15:58:09 +01001660 item = btrfs_item_nr(slot);
Jan Schmidta542ad12011-06-13 19:52:59 +02001661 iref = btrfs_item_ptr(eb, slot, struct btrfs_inode_ref);
1662
1663 for (cur = 0; cur < btrfs_item_size(eb, item); cur += len) {
1664 name_len = btrfs_inode_ref_name_len(eb, iref);
1665 /* path must be released before calling iterate()! */
Jan Schmidt4692cf52011-12-02 14:56:41 +01001666 pr_debug("following ref at offset %u for inode %llu in "
Geert Uytterhoevenc1c9ff72013-08-20 13:20:07 +02001667 "tree %llu\n", cur, found_key.objectid,
1668 fs_root->objectid);
Mark Fashehd24bec32012-08-08 11:33:54 -07001669 ret = iterate(parent, name_len,
1670 (unsigned long)(iref + 1), eb, ctx);
Jan Schmidtaefc1eb2012-04-13 12:28:00 +02001671 if (ret)
Jan Schmidta542ad12011-06-13 19:52:59 +02001672 break;
Jan Schmidta542ad12011-06-13 19:52:59 +02001673 len = sizeof(*iref) + name_len;
1674 iref = (struct btrfs_inode_ref *)((char *)iref + len);
1675 }
Jan Schmidtb916a592012-04-13 12:28:08 +02001676 btrfs_tree_read_unlock_blocking(eb);
Jan Schmidta542ad12011-06-13 19:52:59 +02001677 free_extent_buffer(eb);
1678 }
1679
1680 btrfs_release_path(path);
1681
1682 return ret;
1683}
1684
Mark Fashehd24bec32012-08-08 11:33:54 -07001685static int iterate_inode_extrefs(u64 inum, struct btrfs_root *fs_root,
1686 struct btrfs_path *path,
1687 iterate_irefs_t *iterate, void *ctx)
1688{
1689 int ret;
1690 int slot;
1691 u64 offset = 0;
1692 u64 parent;
1693 int found = 0;
1694 struct extent_buffer *eb;
1695 struct btrfs_inode_extref *extref;
1696 struct extent_buffer *leaf;
1697 u32 item_size;
1698 u32 cur_offset;
1699 unsigned long ptr;
1700
1701 while (1) {
1702 ret = btrfs_find_one_extref(fs_root, inum, offset, path, &extref,
1703 &offset);
1704 if (ret < 0)
1705 break;
1706 if (ret) {
1707 ret = found ? 0 : -ENOENT;
1708 break;
1709 }
1710 ++found;
1711
1712 slot = path->slots[0];
Filipe David Borba Manana3fe81ce2013-12-15 12:43:58 +00001713 eb = btrfs_clone_extent_buffer(path->nodes[0]);
1714 if (!eb) {
1715 ret = -ENOMEM;
1716 break;
1717 }
1718 extent_buffer_get(eb);
Mark Fashehd24bec32012-08-08 11:33:54 -07001719
1720 btrfs_tree_read_lock(eb);
1721 btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK);
1722 btrfs_release_path(path);
1723
1724 leaf = path->nodes[0];
Valentina Giustie94acd82013-11-04 22:34:28 +01001725 item_size = btrfs_item_size_nr(leaf, slot);
1726 ptr = btrfs_item_ptr_offset(leaf, slot);
Mark Fashehd24bec32012-08-08 11:33:54 -07001727 cur_offset = 0;
1728
1729 while (cur_offset < item_size) {
1730 u32 name_len;
1731
1732 extref = (struct btrfs_inode_extref *)(ptr + cur_offset);
1733 parent = btrfs_inode_extref_parent(eb, extref);
1734 name_len = btrfs_inode_extref_name_len(eb, extref);
1735 ret = iterate(parent, name_len,
1736 (unsigned long)&extref->name, eb, ctx);
1737 if (ret)
1738 break;
1739
1740 cur_offset += btrfs_inode_extref_name_len(leaf, extref);
1741 cur_offset += sizeof(*extref);
1742 }
1743 btrfs_tree_read_unlock_blocking(eb);
1744 free_extent_buffer(eb);
1745
1746 offset++;
1747 }
1748
1749 btrfs_release_path(path);
1750
1751 return ret;
1752}
1753
1754static int iterate_irefs(u64 inum, struct btrfs_root *fs_root,
1755 struct btrfs_path *path, iterate_irefs_t *iterate,
1756 void *ctx)
1757{
1758 int ret;
1759 int found_refs = 0;
1760
1761 ret = iterate_inode_refs(inum, fs_root, path, iterate, ctx);
1762 if (!ret)
1763 ++found_refs;
1764 else if (ret != -ENOENT)
1765 return ret;
1766
1767 ret = iterate_inode_extrefs(inum, fs_root, path, iterate, ctx);
1768 if (ret == -ENOENT && found_refs)
1769 return 0;
1770
1771 return ret;
1772}
1773
Jan Schmidta542ad12011-06-13 19:52:59 +02001774/*
1775 * returns 0 if the path could be dumped (probably truncated)
1776 * returns <0 in case of an error
1777 */
Mark Fashehd24bec32012-08-08 11:33:54 -07001778static int inode_to_path(u64 inum, u32 name_len, unsigned long name_off,
1779 struct extent_buffer *eb, void *ctx)
Jan Schmidta542ad12011-06-13 19:52:59 +02001780{
1781 struct inode_fs_paths *ipath = ctx;
1782 char *fspath;
1783 char *fspath_min;
1784 int i = ipath->fspath->elem_cnt;
1785 const int s_ptr = sizeof(char *);
1786 u32 bytes_left;
1787
1788 bytes_left = ipath->fspath->bytes_left > s_ptr ?
1789 ipath->fspath->bytes_left - s_ptr : 0;
1790
Chris Mason740c3d22011-11-02 15:48:34 -04001791 fspath_min = (char *)ipath->fspath->val + (i + 1) * s_ptr;
Jan Schmidt96b5bd72012-10-15 08:30:45 +00001792 fspath = btrfs_ref_to_path(ipath->fs_root, ipath->btrfs_path, name_len,
1793 name_off, eb, inum, fspath_min, bytes_left);
Jan Schmidta542ad12011-06-13 19:52:59 +02001794 if (IS_ERR(fspath))
1795 return PTR_ERR(fspath);
1796
1797 if (fspath > fspath_min) {
Jeff Mahoney745c4d82011-11-20 07:31:57 -05001798 ipath->fspath->val[i] = (u64)(unsigned long)fspath;
Jan Schmidta542ad12011-06-13 19:52:59 +02001799 ++ipath->fspath->elem_cnt;
1800 ipath->fspath->bytes_left = fspath - fspath_min;
1801 } else {
1802 ++ipath->fspath->elem_missed;
1803 ipath->fspath->bytes_missing += fspath_min - fspath;
1804 ipath->fspath->bytes_left = 0;
1805 }
1806
1807 return 0;
1808}
1809
1810/*
1811 * this dumps all file system paths to the inode into the ipath struct, provided
1812 * is has been created large enough. each path is zero-terminated and accessed
Chris Mason740c3d22011-11-02 15:48:34 -04001813 * from ipath->fspath->val[i].
Jan Schmidta542ad12011-06-13 19:52:59 +02001814 * when it returns, there are ipath->fspath->elem_cnt number of paths available
Chris Mason740c3d22011-11-02 15:48:34 -04001815 * in ipath->fspath->val[]. when the allocated space wasn't sufficient, the
Jan Schmidta542ad12011-06-13 19:52:59 +02001816 * number of missed paths in recored in ipath->fspath->elem_missed, otherwise,
1817 * it's zero. ipath->fspath->bytes_missing holds the number of bytes that would
1818 * have been needed to return all paths.
1819 */
1820int paths_from_inode(u64 inum, struct inode_fs_paths *ipath)
1821{
1822 return iterate_irefs(inum, ipath->fs_root, ipath->btrfs_path,
Mark Fashehd24bec32012-08-08 11:33:54 -07001823 inode_to_path, ipath);
Jan Schmidta542ad12011-06-13 19:52:59 +02001824}
1825
Jan Schmidta542ad12011-06-13 19:52:59 +02001826struct btrfs_data_container *init_data_container(u32 total_bytes)
1827{
1828 struct btrfs_data_container *data;
1829 size_t alloc_bytes;
1830
1831 alloc_bytes = max_t(size_t, total_bytes, sizeof(*data));
Liu Bo425d17a2012-09-07 20:01:30 -06001832 data = vmalloc(alloc_bytes);
Jan Schmidta542ad12011-06-13 19:52:59 +02001833 if (!data)
1834 return ERR_PTR(-ENOMEM);
1835
1836 if (total_bytes >= sizeof(*data)) {
1837 data->bytes_left = total_bytes - sizeof(*data);
1838 data->bytes_missing = 0;
1839 } else {
1840 data->bytes_missing = sizeof(*data) - total_bytes;
1841 data->bytes_left = 0;
1842 }
1843
1844 data->elem_cnt = 0;
1845 data->elem_missed = 0;
1846
1847 return data;
1848}
1849
1850/*
1851 * allocates space to return multiple file system paths for an inode.
1852 * total_bytes to allocate are passed, note that space usable for actual path
1853 * information will be total_bytes - sizeof(struct inode_fs_paths).
1854 * the returned pointer must be freed with free_ipath() in the end.
1855 */
1856struct inode_fs_paths *init_ipath(s32 total_bytes, struct btrfs_root *fs_root,
1857 struct btrfs_path *path)
1858{
1859 struct inode_fs_paths *ifp;
1860 struct btrfs_data_container *fspath;
1861
1862 fspath = init_data_container(total_bytes);
1863 if (IS_ERR(fspath))
1864 return (void *)fspath;
1865
1866 ifp = kmalloc(sizeof(*ifp), GFP_NOFS);
1867 if (!ifp) {
1868 kfree(fspath);
1869 return ERR_PTR(-ENOMEM);
1870 }
1871
1872 ifp->btrfs_path = path;
1873 ifp->fspath = fspath;
1874 ifp->fs_root = fs_root;
1875
1876 return ifp;
1877}
1878
1879void free_ipath(struct inode_fs_paths *ipath)
1880{
Jesper Juhl4735fb22012-04-12 22:47:52 +02001881 if (!ipath)
1882 return;
Liu Bo425d17a2012-09-07 20:01:30 -06001883 vfree(ipath->fspath);
Jan Schmidta542ad12011-06-13 19:52:59 +02001884 kfree(ipath);
1885}