blob: a1efd39ca28ab15bb6b8279cc275ce21ab2c06f4 [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;
279 ret = ulist_add_merge(parents, eb->start,
280 (uintptr_t)eie,
281 (u64 *)&old, GFP_NOFS);
282 if (ret < 0)
283 break;
284 if (!ret && extent_item_pos) {
285 while (old->next)
286 old = old->next;
287 old->next = eie;
Alexander Block69bca402012-06-19 07:42:26 -0600288 }
Wang Shilongf05c4742014-01-28 19:13:38 +0800289 eie = NULL;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100290 }
Josef Baciked8c4912013-07-05 14:03:47 -0400291next:
Alexander Block69bca402012-06-19 07:42:26 -0600292 ret = btrfs_next_old_item(root, path, time_seq);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100293 }
294
Alexander Block69bca402012-06-19 07:42:26 -0600295 if (ret > 0)
296 ret = 0;
Wang Shilongf05c4742014-01-28 19:13:38 +0800297 else if (ret < 0)
298 free_inode_elem_list(eie);
Alexander Block69bca402012-06-19 07:42:26 -0600299 return ret;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100300}
301
302/*
303 * resolve an indirect backref in the form (root_id, key, level)
304 * to a logical address
305 */
306static int __resolve_indirect_ref(struct btrfs_fs_info *fs_info,
Josef Bacikda61d312013-06-12 16:20:08 -0400307 struct btrfs_path *path, u64 time_seq,
308 struct __prelim_ref *ref,
309 struct ulist *parents,
Josef Bacik44853862014-03-19 13:35:14 -0400310 const u64 *extent_item_pos, u64 total_refs)
Jan Schmidt8da6d582011-11-23 18:55:04 +0100311{
Jan Schmidt8da6d582011-11-23 18:55:04 +0100312 struct btrfs_root *root;
313 struct btrfs_key root_key;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100314 struct extent_buffer *eb;
315 int ret = 0;
316 int root_level;
317 int level = ref->level;
Wang Shilong538f72cd2014-01-23 13:47:48 +0800318 int index;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100319
Jan Schmidt8da6d582011-11-23 18:55:04 +0100320 root_key.objectid = ref->root_id;
321 root_key.type = BTRFS_ROOT_ITEM_KEY;
322 root_key.offset = (u64)-1;
Wang Shilong538f72cd2014-01-23 13:47:48 +0800323
324 index = srcu_read_lock(&fs_info->subvol_srcu);
325
Jan Schmidt8da6d582011-11-23 18:55:04 +0100326 root = btrfs_read_fs_root_no_name(fs_info, &root_key);
327 if (IS_ERR(root)) {
Wang Shilong538f72cd2014-01-23 13:47:48 +0800328 srcu_read_unlock(&fs_info->subvol_srcu, index);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100329 ret = PTR_ERR(root);
330 goto out;
331 }
332
Josef Bacik9e351cc2014-03-13 15:42:13 -0400333 if (path->search_commit_root)
334 root_level = btrfs_header_level(root->commit_root);
335 else
336 root_level = btrfs_old_root_level(root, time_seq);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100337
Wang Shilong538f72cd2014-01-23 13:47:48 +0800338 if (root_level + 1 == level) {
339 srcu_read_unlock(&fs_info->subvol_srcu, index);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100340 goto out;
Wang Shilong538f72cd2014-01-23 13:47:48 +0800341 }
Jan Schmidt8da6d582011-11-23 18:55:04 +0100342
343 path->lowest_level = level;
Jan Schmidt8445f612012-05-16 18:36:03 +0200344 ret = btrfs_search_old_slot(root, &ref->key_for_search, path, time_seq);
Wang Shilong538f72cd2014-01-23 13:47:48 +0800345
346 /* root node has been locked, we can release @subvol_srcu safely here */
347 srcu_read_unlock(&fs_info->subvol_srcu, index);
348
Jan Schmidt8da6d582011-11-23 18:55:04 +0100349 pr_debug("search slot in root %llu (level %d, ref count %d) returned "
350 "%d for key (%llu %u %llu)\n",
Geert Uytterhoevenc1c9ff72013-08-20 13:20:07 +0200351 ref->root_id, level, ref->count, ret,
352 ref->key_for_search.objectid, ref->key_for_search.type,
353 ref->key_for_search.offset);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100354 if (ret < 0)
355 goto out;
356
357 eb = path->nodes[level];
Jan Schmidt93454572012-06-27 15:23:09 +0200358 while (!eb) {
Dulshani Gunawardhanafae7f212013-10-31 10:30:08 +0530359 if (WARN_ON(!level)) {
Jan Schmidt93454572012-06-27 15:23:09 +0200360 ret = 1;
361 goto out;
362 }
363 level--;
364 eb = path->nodes[level];
Jan Schmidt8da6d582011-11-23 18:55:04 +0100365 }
366
Josef Bacik7ef81ac2014-01-24 14:05:42 -0500367 ret = add_all_parents(root, path, parents, ref, level, time_seq,
Josef Bacik44853862014-03-19 13:35:14 -0400368 extent_item_pos, total_refs);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100369out:
Josef Bacikda61d312013-06-12 16:20:08 -0400370 path->lowest_level = 0;
371 btrfs_release_path(path);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100372 return ret;
373}
374
375/*
376 * resolve all indirect backrefs from the list
377 */
378static int __resolve_indirect_refs(struct btrfs_fs_info *fs_info,
Josef Bacikda61d312013-06-12 16:20:08 -0400379 struct btrfs_path *path, u64 time_seq,
Jan Schmidt976b1902012-05-17 16:43:03 +0200380 struct list_head *head,
Josef Bacik44853862014-03-19 13:35:14 -0400381 const u64 *extent_item_pos, u64 total_refs)
Jan Schmidt8da6d582011-11-23 18:55:04 +0100382{
383 int err;
384 int ret = 0;
385 struct __prelim_ref *ref;
386 struct __prelim_ref *ref_safe;
387 struct __prelim_ref *new_ref;
388 struct ulist *parents;
389 struct ulist_node *node;
Jan Schmidtcd1b4132012-05-22 14:56:50 +0200390 struct ulist_iterator uiter;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100391
392 parents = ulist_alloc(GFP_NOFS);
393 if (!parents)
394 return -ENOMEM;
395
396 /*
397 * _safe allows us to insert directly after the current item without
398 * iterating over the newly inserted items.
399 * we're also allowed to re-assign ref during iteration.
400 */
401 list_for_each_entry_safe(ref, ref_safe, head, list) {
402 if (ref->parent) /* already direct */
403 continue;
404 if (ref->count == 0)
405 continue;
Josef Bacikda61d312013-06-12 16:20:08 -0400406 err = __resolve_indirect_ref(fs_info, path, time_seq, ref,
Josef Bacik44853862014-03-19 13:35:14 -0400407 parents, extent_item_pos,
408 total_refs);
Wang Shilong95def2ed2014-01-23 13:47:49 +0800409 /*
410 * we can only tolerate ENOENT,otherwise,we should catch error
411 * and return directly.
412 */
413 if (err == -ENOENT) {
Jan Schmidt8da6d582011-11-23 18:55:04 +0100414 continue;
Wang Shilong95def2ed2014-01-23 13:47:49 +0800415 } else if (err) {
416 ret = err;
417 goto out;
418 }
Jan Schmidt8da6d582011-11-23 18:55:04 +0100419
420 /* we put the first parent into the ref at hand */
Jan Schmidtcd1b4132012-05-22 14:56:50 +0200421 ULIST_ITER_INIT(&uiter);
422 node = ulist_next(parents, &uiter);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100423 ref->parent = node ? node->val : 0;
Jan Schmidt995e01b2012-08-13 02:52:38 -0600424 ref->inode_list = node ?
Stefan Behrens35a36212013-08-14 18:12:25 +0200425 (struct extent_inode_elem *)(uintptr_t)node->aux : NULL;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100426
427 /* additional parents require new refs being added here */
Jan Schmidtcd1b4132012-05-22 14:56:50 +0200428 while ((node = ulist_next(parents, &uiter))) {
Wang Shilongb9e9a6c2013-08-09 13:25:36 +0800429 new_ref = kmem_cache_alloc(btrfs_prelim_ref_cache,
430 GFP_NOFS);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100431 if (!new_ref) {
432 ret = -ENOMEM;
Wang Shilonge36902d2013-04-15 10:26:38 +0000433 goto out;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100434 }
435 memcpy(new_ref, ref, sizeof(*ref));
436 new_ref->parent = node->val;
Jan Schmidt995e01b2012-08-13 02:52:38 -0600437 new_ref->inode_list = (struct extent_inode_elem *)
438 (uintptr_t)node->aux;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100439 list_add(&new_ref->list, &ref->list);
440 }
441 ulist_reinit(parents);
442 }
Wang Shilonge36902d2013-04-15 10:26:38 +0000443out:
Jan Schmidt8da6d582011-11-23 18:55:04 +0100444 ulist_free(parents);
445 return ret;
446}
447
Jan Schmidtd5c88b72012-05-15 17:55:51 +0200448static inline int ref_for_same_block(struct __prelim_ref *ref1,
449 struct __prelim_ref *ref2)
450{
451 if (ref1->level != ref2->level)
452 return 0;
453 if (ref1->root_id != ref2->root_id)
454 return 0;
455 if (ref1->key_for_search.type != ref2->key_for_search.type)
456 return 0;
457 if (ref1->key_for_search.objectid != ref2->key_for_search.objectid)
458 return 0;
459 if (ref1->key_for_search.offset != ref2->key_for_search.offset)
460 return 0;
461 if (ref1->parent != ref2->parent)
462 return 0;
463
464 return 1;
465}
466
467/*
468 * read tree blocks and add keys where required.
469 */
470static int __add_missing_keys(struct btrfs_fs_info *fs_info,
471 struct list_head *head)
472{
473 struct list_head *pos;
474 struct extent_buffer *eb;
475
476 list_for_each(pos, head) {
477 struct __prelim_ref *ref;
478 ref = list_entry(pos, struct __prelim_ref, list);
479
480 if (ref->parent)
481 continue;
482 if (ref->key_for_search.type)
483 continue;
484 BUG_ON(!ref->wanted_disk_byte);
485 eb = read_tree_block(fs_info->tree_root, ref->wanted_disk_byte,
486 fs_info->tree_root->leafsize, 0);
Josef Bacik416bc652013-04-23 14:17:42 -0400487 if (!eb || !extent_buffer_uptodate(eb)) {
488 free_extent_buffer(eb);
489 return -EIO;
490 }
Jan Schmidtd5c88b72012-05-15 17:55:51 +0200491 btrfs_tree_read_lock(eb);
492 if (btrfs_header_level(eb) == 0)
493 btrfs_item_key_to_cpu(eb, &ref->key_for_search, 0);
494 else
495 btrfs_node_key_to_cpu(eb, &ref->key_for_search, 0);
496 btrfs_tree_read_unlock(eb);
497 free_extent_buffer(eb);
498 }
499 return 0;
500}
501
Jan Schmidt8da6d582011-11-23 18:55:04 +0100502/*
503 * merge two lists of backrefs and adjust counts accordingly
504 *
505 * mode = 1: merge identical keys, if key is set
Jan Schmidtd5c88b72012-05-15 17:55:51 +0200506 * FIXME: if we add more keys in __add_prelim_ref, we can merge more here.
507 * additionally, we could even add a key range for the blocks we
508 * looked into to merge even more (-> replace unresolved refs by those
509 * having a parent).
Jan Schmidt8da6d582011-11-23 18:55:04 +0100510 * mode = 2: merge identical parents
511 */
Wang Shilong692206b2013-04-11 07:08:55 +0000512static void __merge_refs(struct list_head *head, int mode)
Jan Schmidt8da6d582011-11-23 18:55:04 +0100513{
514 struct list_head *pos1;
515
516 list_for_each(pos1, head) {
517 struct list_head *n2;
518 struct list_head *pos2;
519 struct __prelim_ref *ref1;
520
521 ref1 = list_entry(pos1, struct __prelim_ref, list);
522
Jan Schmidt8da6d582011-11-23 18:55:04 +0100523 for (pos2 = pos1->next, n2 = pos2->next; pos2 != head;
524 pos2 = n2, n2 = pos2->next) {
525 struct __prelim_ref *ref2;
Jan Schmidtd5c88b72012-05-15 17:55:51 +0200526 struct __prelim_ref *xchg;
Alexander Block3ef59692012-11-08 21:27:24 +0000527 struct extent_inode_elem *eie;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100528
529 ref2 = list_entry(pos2, struct __prelim_ref, list);
530
531 if (mode == 1) {
Jan Schmidtd5c88b72012-05-15 17:55:51 +0200532 if (!ref_for_same_block(ref1, ref2))
Jan Schmidt8da6d582011-11-23 18:55:04 +0100533 continue;
Jan Schmidtd5c88b72012-05-15 17:55:51 +0200534 if (!ref1->parent && ref2->parent) {
535 xchg = ref1;
536 ref1 = ref2;
537 ref2 = xchg;
538 }
Jan Schmidt8da6d582011-11-23 18:55:04 +0100539 } else {
540 if (ref1->parent != ref2->parent)
541 continue;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100542 }
Alexander Block3ef59692012-11-08 21:27:24 +0000543
544 eie = ref1->inode_list;
545 while (eie && eie->next)
546 eie = eie->next;
547 if (eie)
548 eie->next = ref2->inode_list;
549 else
550 ref1->inode_list = ref2->inode_list;
551 ref1->count += ref2->count;
552
Jan Schmidt8da6d582011-11-23 18:55:04 +0100553 list_del(&ref2->list);
Wang Shilongb9e9a6c2013-08-09 13:25:36 +0800554 kmem_cache_free(btrfs_prelim_ref_cache, ref2);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100555 }
556
557 }
Jan Schmidt8da6d582011-11-23 18:55:04 +0100558}
559
560/*
561 * add all currently queued delayed refs from this head whose seq nr is
562 * smaller or equal that seq to the list
563 */
564static int __add_delayed_refs(struct btrfs_delayed_ref_head *head, u64 seq,
Josef Bacik44853862014-03-19 13:35:14 -0400565 struct list_head *prefs, u64 *total_refs)
Jan Schmidt8da6d582011-11-23 18:55:04 +0100566{
567 struct btrfs_delayed_extent_op *extent_op = head->extent_op;
568 struct rb_node *n = &head->node.rb_node;
Jan Schmidtd5c88b72012-05-15 17:55:51 +0200569 struct btrfs_key key;
570 struct btrfs_key op_key = {0};
Jan Schmidt8da6d582011-11-23 18:55:04 +0100571 int sgn;
Jan Schmidtb1375d62012-01-26 15:01:11 -0500572 int ret = 0;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100573
574 if (extent_op && extent_op->update_key)
Jan Schmidtd5c88b72012-05-15 17:55:51 +0200575 btrfs_disk_key_to_cpu(&op_key, &extent_op->key);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100576
Josef Bacikd7df2c72014-01-23 09:21:38 -0500577 spin_lock(&head->lock);
578 n = rb_first(&head->ref_root);
579 while (n) {
Jan Schmidt8da6d582011-11-23 18:55:04 +0100580 struct btrfs_delayed_ref_node *node;
581 node = rb_entry(n, struct btrfs_delayed_ref_node,
582 rb_node);
Josef Bacikd7df2c72014-01-23 09:21:38 -0500583 n = rb_next(n);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100584 if (node->seq > seq)
585 continue;
586
587 switch (node->action) {
588 case BTRFS_ADD_DELAYED_EXTENT:
589 case BTRFS_UPDATE_DELAYED_HEAD:
590 WARN_ON(1);
591 continue;
592 case BTRFS_ADD_DELAYED_REF:
593 sgn = 1;
594 break;
595 case BTRFS_DROP_DELAYED_REF:
596 sgn = -1;
597 break;
598 default:
599 BUG_ON(1);
600 }
Josef Bacik44853862014-03-19 13:35:14 -0400601 *total_refs += (node->ref_mod * sgn);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100602 switch (node->type) {
603 case BTRFS_TREE_BLOCK_REF_KEY: {
604 struct btrfs_delayed_tree_ref *ref;
605
606 ref = btrfs_delayed_node_to_tree_ref(node);
Jan Schmidtd5c88b72012-05-15 17:55:51 +0200607 ret = __add_prelim_ref(prefs, ref->root, &op_key,
Jan Schmidt8da6d582011-11-23 18:55:04 +0100608 ref->level + 1, 0, node->bytenr,
Wang Shilong742916b2013-08-06 10:29:54 +0800609 node->ref_mod * sgn, GFP_ATOMIC);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100610 break;
611 }
612 case BTRFS_SHARED_BLOCK_REF_KEY: {
613 struct btrfs_delayed_tree_ref *ref;
614
615 ref = btrfs_delayed_node_to_tree_ref(node);
Jan Schmidtd5c88b72012-05-15 17:55:51 +0200616 ret = __add_prelim_ref(prefs, ref->root, NULL,
Jan Schmidt8da6d582011-11-23 18:55:04 +0100617 ref->level + 1, ref->parent,
618 node->bytenr,
Wang Shilong742916b2013-08-06 10:29:54 +0800619 node->ref_mod * sgn, GFP_ATOMIC);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100620 break;
621 }
622 case BTRFS_EXTENT_DATA_REF_KEY: {
623 struct btrfs_delayed_data_ref *ref;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100624 ref = btrfs_delayed_node_to_data_ref(node);
625
626 key.objectid = ref->objectid;
627 key.type = BTRFS_EXTENT_DATA_KEY;
628 key.offset = ref->offset;
629 ret = __add_prelim_ref(prefs, ref->root, &key, 0, 0,
630 node->bytenr,
Wang Shilong742916b2013-08-06 10:29:54 +0800631 node->ref_mod * sgn, GFP_ATOMIC);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100632 break;
633 }
634 case BTRFS_SHARED_DATA_REF_KEY: {
635 struct btrfs_delayed_data_ref *ref;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100636
637 ref = btrfs_delayed_node_to_data_ref(node);
638
639 key.objectid = ref->objectid;
640 key.type = BTRFS_EXTENT_DATA_KEY;
641 key.offset = ref->offset;
642 ret = __add_prelim_ref(prefs, ref->root, &key, 0,
643 ref->parent, node->bytenr,
Wang Shilong742916b2013-08-06 10:29:54 +0800644 node->ref_mod * sgn, GFP_ATOMIC);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100645 break;
646 }
647 default:
648 WARN_ON(1);
649 }
Wang Shilong1149ab62013-04-10 11:22:50 +0000650 if (ret)
Josef Bacikd7df2c72014-01-23 09:21:38 -0500651 break;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100652 }
Josef Bacikd7df2c72014-01-23 09:21:38 -0500653 spin_unlock(&head->lock);
654 return ret;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100655}
656
657/*
658 * add all inline backrefs for bytenr to the list
659 */
660static int __add_inline_refs(struct btrfs_fs_info *fs_info,
661 struct btrfs_path *path, u64 bytenr,
Josef Bacik44853862014-03-19 13:35:14 -0400662 int *info_level, struct list_head *prefs,
663 u64 *total_refs)
Jan Schmidt8da6d582011-11-23 18:55:04 +0100664{
Jan Schmidtb1375d62012-01-26 15:01:11 -0500665 int ret = 0;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100666 int slot;
667 struct extent_buffer *leaf;
668 struct btrfs_key key;
Josef Bacik261c84b2013-06-28 13:11:22 -0400669 struct btrfs_key found_key;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100670 unsigned long ptr;
671 unsigned long end;
672 struct btrfs_extent_item *ei;
673 u64 flags;
674 u64 item_size;
675
676 /*
677 * enumerate all inline refs
678 */
679 leaf = path->nodes[0];
Jan Schmidtdadcaf72012-05-22 13:43:25 +0200680 slot = path->slots[0];
Jan Schmidt8da6d582011-11-23 18:55:04 +0100681
682 item_size = btrfs_item_size_nr(leaf, slot);
683 BUG_ON(item_size < sizeof(*ei));
684
685 ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item);
686 flags = btrfs_extent_flags(leaf, ei);
Josef Bacik44853862014-03-19 13:35:14 -0400687 *total_refs += btrfs_extent_refs(leaf, ei);
Josef Bacik261c84b2013-06-28 13:11:22 -0400688 btrfs_item_key_to_cpu(leaf, &found_key, slot);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100689
690 ptr = (unsigned long)(ei + 1);
691 end = (unsigned long)ei + item_size;
692
Josef Bacik261c84b2013-06-28 13:11:22 -0400693 if (found_key.type == BTRFS_EXTENT_ITEM_KEY &&
694 flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
Jan Schmidt8da6d582011-11-23 18:55:04 +0100695 struct btrfs_tree_block_info *info;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100696
697 info = (struct btrfs_tree_block_info *)ptr;
698 *info_level = btrfs_tree_block_level(leaf, info);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100699 ptr += sizeof(struct btrfs_tree_block_info);
700 BUG_ON(ptr > end);
Josef Bacik261c84b2013-06-28 13:11:22 -0400701 } else if (found_key.type == BTRFS_METADATA_ITEM_KEY) {
702 *info_level = found_key.offset;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100703 } else {
704 BUG_ON(!(flags & BTRFS_EXTENT_FLAG_DATA));
705 }
706
707 while (ptr < end) {
708 struct btrfs_extent_inline_ref *iref;
709 u64 offset;
710 int type;
711
712 iref = (struct btrfs_extent_inline_ref *)ptr;
713 type = btrfs_extent_inline_ref_type(leaf, iref);
714 offset = btrfs_extent_inline_ref_offset(leaf, iref);
715
716 switch (type) {
717 case BTRFS_SHARED_BLOCK_REF_KEY:
Jan Schmidtd5c88b72012-05-15 17:55:51 +0200718 ret = __add_prelim_ref(prefs, 0, NULL,
Jan Schmidt8da6d582011-11-23 18:55:04 +0100719 *info_level + 1, offset,
Wang Shilong742916b2013-08-06 10:29:54 +0800720 bytenr, 1, GFP_NOFS);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100721 break;
722 case BTRFS_SHARED_DATA_REF_KEY: {
723 struct btrfs_shared_data_ref *sdref;
724 int count;
725
726 sdref = (struct btrfs_shared_data_ref *)(iref + 1);
727 count = btrfs_shared_data_ref_count(leaf, sdref);
728 ret = __add_prelim_ref(prefs, 0, NULL, 0, offset,
Wang Shilong742916b2013-08-06 10:29:54 +0800729 bytenr, count, GFP_NOFS);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100730 break;
731 }
732 case BTRFS_TREE_BLOCK_REF_KEY:
Jan Schmidtd5c88b72012-05-15 17:55:51 +0200733 ret = __add_prelim_ref(prefs, offset, NULL,
734 *info_level + 1, 0,
Wang Shilong742916b2013-08-06 10:29:54 +0800735 bytenr, 1, GFP_NOFS);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100736 break;
737 case BTRFS_EXTENT_DATA_REF_KEY: {
738 struct btrfs_extent_data_ref *dref;
739 int count;
740 u64 root;
741
742 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
743 count = btrfs_extent_data_ref_count(leaf, dref);
744 key.objectid = btrfs_extent_data_ref_objectid(leaf,
745 dref);
746 key.type = BTRFS_EXTENT_DATA_KEY;
747 key.offset = btrfs_extent_data_ref_offset(leaf, dref);
748 root = btrfs_extent_data_ref_root(leaf, dref);
Jan Schmidtd5c88b72012-05-15 17:55:51 +0200749 ret = __add_prelim_ref(prefs, root, &key, 0, 0,
Wang Shilong742916b2013-08-06 10:29:54 +0800750 bytenr, count, GFP_NOFS);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100751 break;
752 }
753 default:
754 WARN_ON(1);
755 }
Wang Shilong1149ab62013-04-10 11:22:50 +0000756 if (ret)
757 return ret;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100758 ptr += btrfs_extent_inline_ref_size(type);
759 }
760
761 return 0;
762}
763
764/*
765 * add all non-inline backrefs for bytenr to the list
766 */
767static int __add_keyed_refs(struct btrfs_fs_info *fs_info,
768 struct btrfs_path *path, u64 bytenr,
Jan Schmidtd5c88b72012-05-15 17:55:51 +0200769 int info_level, struct list_head *prefs)
Jan Schmidt8da6d582011-11-23 18:55:04 +0100770{
771 struct btrfs_root *extent_root = fs_info->extent_root;
772 int ret;
773 int slot;
774 struct extent_buffer *leaf;
775 struct btrfs_key key;
776
777 while (1) {
778 ret = btrfs_next_item(extent_root, path);
779 if (ret < 0)
780 break;
781 if (ret) {
782 ret = 0;
783 break;
784 }
785
786 slot = path->slots[0];
787 leaf = path->nodes[0];
788 btrfs_item_key_to_cpu(leaf, &key, slot);
789
790 if (key.objectid != bytenr)
791 break;
792 if (key.type < BTRFS_TREE_BLOCK_REF_KEY)
793 continue;
794 if (key.type > BTRFS_SHARED_DATA_REF_KEY)
795 break;
796
797 switch (key.type) {
798 case BTRFS_SHARED_BLOCK_REF_KEY:
Jan Schmidtd5c88b72012-05-15 17:55:51 +0200799 ret = __add_prelim_ref(prefs, 0, NULL,
Jan Schmidt8da6d582011-11-23 18:55:04 +0100800 info_level + 1, key.offset,
Wang Shilong742916b2013-08-06 10:29:54 +0800801 bytenr, 1, GFP_NOFS);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100802 break;
803 case BTRFS_SHARED_DATA_REF_KEY: {
804 struct btrfs_shared_data_ref *sdref;
805 int count;
806
807 sdref = btrfs_item_ptr(leaf, slot,
808 struct btrfs_shared_data_ref);
809 count = btrfs_shared_data_ref_count(leaf, sdref);
810 ret = __add_prelim_ref(prefs, 0, NULL, 0, key.offset,
Wang Shilong742916b2013-08-06 10:29:54 +0800811 bytenr, count, GFP_NOFS);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100812 break;
813 }
814 case BTRFS_TREE_BLOCK_REF_KEY:
Jan Schmidtd5c88b72012-05-15 17:55:51 +0200815 ret = __add_prelim_ref(prefs, key.offset, NULL,
816 info_level + 1, 0,
Wang Shilong742916b2013-08-06 10:29:54 +0800817 bytenr, 1, GFP_NOFS);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100818 break;
819 case BTRFS_EXTENT_DATA_REF_KEY: {
820 struct btrfs_extent_data_ref *dref;
821 int count;
822 u64 root;
823
824 dref = btrfs_item_ptr(leaf, slot,
825 struct btrfs_extent_data_ref);
826 count = btrfs_extent_data_ref_count(leaf, dref);
827 key.objectid = btrfs_extent_data_ref_objectid(leaf,
828 dref);
829 key.type = BTRFS_EXTENT_DATA_KEY;
830 key.offset = btrfs_extent_data_ref_offset(leaf, dref);
831 root = btrfs_extent_data_ref_root(leaf, dref);
832 ret = __add_prelim_ref(prefs, root, &key, 0, 0,
Wang Shilong742916b2013-08-06 10:29:54 +0800833 bytenr, count, GFP_NOFS);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100834 break;
835 }
836 default:
837 WARN_ON(1);
838 }
Wang Shilong1149ab62013-04-10 11:22:50 +0000839 if (ret)
840 return ret;
841
Jan Schmidt8da6d582011-11-23 18:55:04 +0100842 }
843
844 return ret;
845}
846
847/*
848 * this adds all existing backrefs (inline backrefs, backrefs and delayed
849 * refs) for the given bytenr to the refs list, merges duplicates and resolves
850 * indirect refs to their parent bytenr.
851 * When roots are found, they're added to the roots list
852 *
853 * FIXME some caching might speed things up
854 */
855static int find_parent_nodes(struct btrfs_trans_handle *trans,
856 struct btrfs_fs_info *fs_info, u64 bytenr,
Jan Schmidt097b8a72012-06-21 11:08:04 +0200857 u64 time_seq, struct ulist *refs,
858 struct ulist *roots, const u64 *extent_item_pos)
Jan Schmidt8da6d582011-11-23 18:55:04 +0100859{
860 struct btrfs_key key;
861 struct btrfs_path *path;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100862 struct btrfs_delayed_ref_root *delayed_refs = NULL;
Li Zefand3b01062012-03-03 07:41:15 -0500863 struct btrfs_delayed_ref_head *head;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100864 int info_level = 0;
865 int ret;
866 struct list_head prefs_delayed;
867 struct list_head prefs;
868 struct __prelim_ref *ref;
Wang Shilongf05c4742014-01-28 19:13:38 +0800869 struct extent_inode_elem *eie = NULL;
Josef Bacik44853862014-03-19 13:35:14 -0400870 u64 total_refs = 0;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100871
872 INIT_LIST_HEAD(&prefs);
873 INIT_LIST_HEAD(&prefs_delayed);
874
875 key.objectid = bytenr;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100876 key.offset = (u64)-1;
Josef Bacik261c84b2013-06-28 13:11:22 -0400877 if (btrfs_fs_incompat(fs_info, SKINNY_METADATA))
878 key.type = BTRFS_METADATA_ITEM_KEY;
879 else
880 key.type = BTRFS_EXTENT_ITEM_KEY;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100881
882 path = btrfs_alloc_path();
883 if (!path)
884 return -ENOMEM;
Wang Shilonge84752d2014-02-13 11:19:47 +0800885 if (!trans) {
Josef Bacikda61d312013-06-12 16:20:08 -0400886 path->search_commit_root = 1;
Wang Shilonge84752d2014-02-13 11:19:47 +0800887 path->skip_locking = 1;
888 }
Jan Schmidt8da6d582011-11-23 18:55:04 +0100889
890 /*
891 * grab both a lock on the path and a lock on the delayed ref head.
892 * We need both to get a consistent picture of how the refs look
893 * at a specified point in time
894 */
895again:
Li Zefand3b01062012-03-03 07:41:15 -0500896 head = NULL;
897
Jan Schmidt8da6d582011-11-23 18:55:04 +0100898 ret = btrfs_search_slot(trans, fs_info->extent_root, &key, path, 0, 0);
899 if (ret < 0)
900 goto out;
901 BUG_ON(ret == 0);
902
Josef Bacikfaa2dbf2014-05-07 17:06:09 -0400903#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
904 if (trans && likely(trans->type != __TRANS_DUMMY)) {
905#else
Josef Bacikda61d312013-06-12 16:20:08 -0400906 if (trans) {
Josef Bacikfaa2dbf2014-05-07 17:06:09 -0400907#endif
Jan Schmidt7a3ae2f2012-03-23 17:32:28 +0100908 /*
909 * look if there are updates for this ref queued and lock the
910 * head
911 */
912 delayed_refs = &trans->transaction->delayed_refs;
913 spin_lock(&delayed_refs->lock);
914 head = btrfs_find_delayed_ref_head(trans, bytenr);
915 if (head) {
916 if (!mutex_trylock(&head->mutex)) {
917 atomic_inc(&head->node.refs);
918 spin_unlock(&delayed_refs->lock);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100919
Jan Schmidt7a3ae2f2012-03-23 17:32:28 +0100920 btrfs_release_path(path);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100921
Jan Schmidt7a3ae2f2012-03-23 17:32:28 +0100922 /*
923 * Mutex was contended, block until it's
924 * released and try again
925 */
926 mutex_lock(&head->mutex);
927 mutex_unlock(&head->mutex);
928 btrfs_put_delayed_ref(&head->node);
929 goto again;
930 }
Josef Bacikd7df2c72014-01-23 09:21:38 -0500931 spin_unlock(&delayed_refs->lock);
Jan Schmidt097b8a72012-06-21 11:08:04 +0200932 ret = __add_delayed_refs(head, time_seq,
Josef Bacik44853862014-03-19 13:35:14 -0400933 &prefs_delayed, &total_refs);
Jan Schmidt155725c2012-06-22 14:01:00 +0200934 mutex_unlock(&head->mutex);
Josef Bacikd7df2c72014-01-23 09:21:38 -0500935 if (ret)
Jan Schmidt7a3ae2f2012-03-23 17:32:28 +0100936 goto out;
Josef Bacikd7df2c72014-01-23 09:21:38 -0500937 } else {
938 spin_unlock(&delayed_refs->lock);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100939 }
Jan Schmidt8da6d582011-11-23 18:55:04 +0100940 }
Jan Schmidt8da6d582011-11-23 18:55:04 +0100941
942 if (path->slots[0]) {
943 struct extent_buffer *leaf;
944 int slot;
945
Jan Schmidtdadcaf72012-05-22 13:43:25 +0200946 path->slots[0]--;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100947 leaf = path->nodes[0];
Jan Schmidtdadcaf72012-05-22 13:43:25 +0200948 slot = path->slots[0];
Jan Schmidt8da6d582011-11-23 18:55:04 +0100949 btrfs_item_key_to_cpu(leaf, &key, slot);
950 if (key.objectid == bytenr &&
Josef Bacik261c84b2013-06-28 13:11:22 -0400951 (key.type == BTRFS_EXTENT_ITEM_KEY ||
952 key.type == BTRFS_METADATA_ITEM_KEY)) {
Jan Schmidt8da6d582011-11-23 18:55:04 +0100953 ret = __add_inline_refs(fs_info, path, bytenr,
Josef Bacik44853862014-03-19 13:35:14 -0400954 &info_level, &prefs,
955 &total_refs);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100956 if (ret)
957 goto out;
Jan Schmidtd5c88b72012-05-15 17:55:51 +0200958 ret = __add_keyed_refs(fs_info, path, bytenr,
Jan Schmidt8da6d582011-11-23 18:55:04 +0100959 info_level, &prefs);
960 if (ret)
961 goto out;
962 }
963 }
964 btrfs_release_path(path);
965
Jan Schmidt8da6d582011-11-23 18:55:04 +0100966 list_splice_init(&prefs_delayed, &prefs);
967
Jan Schmidtd5c88b72012-05-15 17:55:51 +0200968 ret = __add_missing_keys(fs_info, &prefs);
969 if (ret)
970 goto out;
971
Wang Shilong692206b2013-04-11 07:08:55 +0000972 __merge_refs(&prefs, 1);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100973
Josef Bacikda61d312013-06-12 16:20:08 -0400974 ret = __resolve_indirect_refs(fs_info, path, time_seq, &prefs,
Josef Bacik44853862014-03-19 13:35:14 -0400975 extent_item_pos, total_refs);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100976 if (ret)
977 goto out;
978
Wang Shilong692206b2013-04-11 07:08:55 +0000979 __merge_refs(&prefs, 2);
Jan Schmidt8da6d582011-11-23 18:55:04 +0100980
981 while (!list_empty(&prefs)) {
982 ref = list_first_entry(&prefs, struct __prelim_ref, list);
Julia Lawall6c1500f2012-11-03 20:30:18 +0000983 WARN_ON(ref->count < 0);
Wang Shilong98cfee212014-02-01 00:42:05 +0800984 if (roots && ref->count && ref->root_id && ref->parent == 0) {
Jan Schmidt8da6d582011-11-23 18:55:04 +0100985 /* no parent == root of tree */
986 ret = ulist_add(roots, ref->root_id, 0, GFP_NOFS);
Wang Shilongf1723932013-03-29 23:03:21 +0000987 if (ret < 0)
988 goto out;
Jan Schmidt8da6d582011-11-23 18:55:04 +0100989 }
990 if (ref->count && ref->parent) {
Josef Bacik8a564572014-06-05 16:08:45 -0400991 if (extent_item_pos && !ref->inode_list &&
992 ref->level == 0) {
Jan Schmidt976b1902012-05-17 16:43:03 +0200993 u32 bsz;
994 struct extent_buffer *eb;
995 bsz = btrfs_level_size(fs_info->extent_root,
Josef Bacik8a564572014-06-05 16:08:45 -0400996 ref->level);
Jan Schmidt976b1902012-05-17 16:43:03 +0200997 eb = read_tree_block(fs_info->extent_root,
998 ref->parent, bsz, 0);
Josef Bacik416bc652013-04-23 14:17:42 -0400999 if (!eb || !extent_buffer_uptodate(eb)) {
1000 free_extent_buffer(eb);
Wang Shilongc16c2e22013-05-08 08:10:25 +00001001 ret = -EIO;
1002 goto out;
Josef Bacik416bc652013-04-23 14:17:42 -04001003 }
Filipe Manana6f7ff6d2014-07-02 20:07:54 +01001004 btrfs_tree_read_lock(eb);
1005 btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK);
Jan Schmidt976b1902012-05-17 16:43:03 +02001006 ret = find_extent_in_eb(eb, bytenr,
1007 *extent_item_pos, &eie);
Filipe Manana6f7ff6d2014-07-02 20:07:54 +01001008 btrfs_tree_read_unlock_blocking(eb);
Jan Schmidt976b1902012-05-17 16:43:03 +02001009 free_extent_buffer(eb);
Filipe David Borba Mananaf5929cd2013-07-31 00:26:35 +01001010 if (ret < 0)
1011 goto out;
1012 ref->inode_list = eie;
Jan Schmidt976b1902012-05-17 16:43:03 +02001013 }
Jan Schmidt33019582012-05-30 18:05:21 +02001014 ret = ulist_add_merge(refs, ref->parent,
Jan Schmidt995e01b2012-08-13 02:52:38 -06001015 (uintptr_t)ref->inode_list,
Alexander Block34d73f52012-07-28 16:18:58 +02001016 (u64 *)&eie, GFP_NOFS);
Wang Shilongf1723932013-03-29 23:03:21 +00001017 if (ret < 0)
1018 goto out;
Jan Schmidt33019582012-05-30 18:05:21 +02001019 if (!ret && extent_item_pos) {
1020 /*
1021 * we've recorded that parent, so we must extend
1022 * its inode list here
1023 */
1024 BUG_ON(!eie);
1025 while (eie->next)
1026 eie = eie->next;
1027 eie->next = ref->inode_list;
1028 }
Wang Shilongf05c4742014-01-28 19:13:38 +08001029 eie = NULL;
Jan Schmidt8da6d582011-11-23 18:55:04 +01001030 }
Wang Shilonga4fdb612013-08-08 13:04:17 +08001031 list_del(&ref->list);
Wang Shilongb9e9a6c2013-08-09 13:25:36 +08001032 kmem_cache_free(btrfs_prelim_ref_cache, ref);
Jan Schmidt8da6d582011-11-23 18:55:04 +01001033 }
1034
1035out:
Jan Schmidt8da6d582011-11-23 18:55:04 +01001036 btrfs_free_path(path);
1037 while (!list_empty(&prefs)) {
1038 ref = list_first_entry(&prefs, struct __prelim_ref, list);
1039 list_del(&ref->list);
Wang Shilongb9e9a6c2013-08-09 13:25:36 +08001040 kmem_cache_free(btrfs_prelim_ref_cache, ref);
Jan Schmidt8da6d582011-11-23 18:55:04 +01001041 }
1042 while (!list_empty(&prefs_delayed)) {
1043 ref = list_first_entry(&prefs_delayed, struct __prelim_ref,
1044 list);
1045 list_del(&ref->list);
Wang Shilongb9e9a6c2013-08-09 13:25:36 +08001046 kmem_cache_free(btrfs_prelim_ref_cache, ref);
Jan Schmidt8da6d582011-11-23 18:55:04 +01001047 }
Wang Shilongf05c4742014-01-28 19:13:38 +08001048 if (ret < 0)
1049 free_inode_elem_list(eie);
Jan Schmidt8da6d582011-11-23 18:55:04 +01001050 return ret;
1051}
1052
Jan Schmidt976b1902012-05-17 16:43:03 +02001053static void free_leaf_list(struct ulist *blocks)
1054{
1055 struct ulist_node *node = NULL;
1056 struct extent_inode_elem *eie;
Jan Schmidt976b1902012-05-17 16:43:03 +02001057 struct ulist_iterator uiter;
1058
1059 ULIST_ITER_INIT(&uiter);
1060 while ((node = ulist_next(blocks, &uiter))) {
1061 if (!node->aux)
1062 continue;
Jan Schmidt995e01b2012-08-13 02:52:38 -06001063 eie = (struct extent_inode_elem *)(uintptr_t)node->aux;
Wang Shilongf05c4742014-01-28 19:13:38 +08001064 free_inode_elem_list(eie);
Jan Schmidt976b1902012-05-17 16:43:03 +02001065 node->aux = 0;
1066 }
1067
1068 ulist_free(blocks);
1069}
1070
Jan Schmidt8da6d582011-11-23 18:55:04 +01001071/*
1072 * Finds all leafs with a reference to the specified combination of bytenr and
1073 * offset. key_list_head will point to a list of corresponding keys (caller must
1074 * free each list element). The leafs will be stored in the leafs ulist, which
1075 * must be freed with ulist_free.
1076 *
1077 * returns 0 on success, <0 on error
1078 */
1079static int btrfs_find_all_leafs(struct btrfs_trans_handle *trans,
1080 struct btrfs_fs_info *fs_info, u64 bytenr,
Jan Schmidt097b8a72012-06-21 11:08:04 +02001081 u64 time_seq, struct ulist **leafs,
Jan Schmidt976b1902012-05-17 16:43:03 +02001082 const u64 *extent_item_pos)
Jan Schmidt8da6d582011-11-23 18:55:04 +01001083{
Jan Schmidt8da6d582011-11-23 18:55:04 +01001084 int ret;
1085
Jan Schmidt8da6d582011-11-23 18:55:04 +01001086 *leafs = ulist_alloc(GFP_NOFS);
Wang Shilong98cfee212014-02-01 00:42:05 +08001087 if (!*leafs)
Jan Schmidt8da6d582011-11-23 18:55:04 +01001088 return -ENOMEM;
Jan Schmidt8da6d582011-11-23 18:55:04 +01001089
Jan Schmidt097b8a72012-06-21 11:08:04 +02001090 ret = find_parent_nodes(trans, fs_info, bytenr,
Wang Shilong98cfee212014-02-01 00:42:05 +08001091 time_seq, *leafs, NULL, extent_item_pos);
Jan Schmidt8da6d582011-11-23 18:55:04 +01001092 if (ret < 0 && ret != -ENOENT) {
Jan Schmidt976b1902012-05-17 16:43:03 +02001093 free_leaf_list(*leafs);
Jan Schmidt8da6d582011-11-23 18:55:04 +01001094 return ret;
1095 }
1096
1097 return 0;
1098}
1099
1100/*
1101 * walk all backrefs for a given extent to find all roots that reference this
1102 * extent. Walking a backref means finding all extents that reference this
1103 * extent and in turn walk the backrefs of those, too. Naturally this is a
1104 * recursive process, but here it is implemented in an iterative fashion: We
1105 * find all referencing extents for the extent in question and put them on a
1106 * list. In turn, we find all referencing extents for those, further appending
1107 * to the list. The way we iterate the list allows adding more elements after
1108 * the current while iterating. The process stops when we reach the end of the
1109 * list. Found roots are added to the roots list.
1110 *
1111 * returns 0 on success, < 0 on error.
1112 */
Josef Bacik9e351cc2014-03-13 15:42:13 -04001113static int __btrfs_find_all_roots(struct btrfs_trans_handle *trans,
1114 struct btrfs_fs_info *fs_info, u64 bytenr,
1115 u64 time_seq, struct ulist **roots)
Jan Schmidt8da6d582011-11-23 18:55:04 +01001116{
1117 struct ulist *tmp;
1118 struct ulist_node *node = NULL;
Jan Schmidtcd1b4132012-05-22 14:56:50 +02001119 struct ulist_iterator uiter;
Jan Schmidt8da6d582011-11-23 18:55:04 +01001120 int ret;
1121
1122 tmp = ulist_alloc(GFP_NOFS);
1123 if (!tmp)
1124 return -ENOMEM;
1125 *roots = ulist_alloc(GFP_NOFS);
1126 if (!*roots) {
1127 ulist_free(tmp);
1128 return -ENOMEM;
1129 }
1130
Jan Schmidtcd1b4132012-05-22 14:56:50 +02001131 ULIST_ITER_INIT(&uiter);
Jan Schmidt8da6d582011-11-23 18:55:04 +01001132 while (1) {
Jan Schmidt097b8a72012-06-21 11:08:04 +02001133 ret = find_parent_nodes(trans, fs_info, bytenr,
Jan Schmidt8445f612012-05-16 18:36:03 +02001134 time_seq, tmp, *roots, NULL);
Jan Schmidt8da6d582011-11-23 18:55:04 +01001135 if (ret < 0 && ret != -ENOENT) {
1136 ulist_free(tmp);
1137 ulist_free(*roots);
1138 return ret;
1139 }
Jan Schmidtcd1b4132012-05-22 14:56:50 +02001140 node = ulist_next(tmp, &uiter);
Jan Schmidt8da6d582011-11-23 18:55:04 +01001141 if (!node)
1142 break;
1143 bytenr = node->val;
Wang Shilongbca1a292014-01-26 22:32:18 +08001144 cond_resched();
Jan Schmidt8da6d582011-11-23 18:55:04 +01001145 }
1146
1147 ulist_free(tmp);
1148 return 0;
1149}
1150
Josef Bacik9e351cc2014-03-13 15:42:13 -04001151int btrfs_find_all_roots(struct btrfs_trans_handle *trans,
1152 struct btrfs_fs_info *fs_info, u64 bytenr,
1153 u64 time_seq, struct ulist **roots)
1154{
1155 int ret;
1156
1157 if (!trans)
1158 down_read(&fs_info->commit_root_sem);
1159 ret = __btrfs_find_all_roots(trans, fs_info, bytenr, time_seq, roots);
1160 if (!trans)
1161 up_read(&fs_info->commit_root_sem);
1162 return ret;
1163}
1164
Jan Schmidta542ad12011-06-13 19:52:59 +02001165/*
1166 * this makes the path point to (inum INODE_ITEM ioff)
1167 */
1168int inode_item_info(u64 inum, u64 ioff, struct btrfs_root *fs_root,
1169 struct btrfs_path *path)
1170{
1171 struct btrfs_key key;
Kelley Nielsene33d5c32013-11-04 19:33:33 -08001172 return btrfs_find_item(fs_root, path, inum, ioff,
1173 BTRFS_INODE_ITEM_KEY, &key);
Jan Schmidta542ad12011-06-13 19:52:59 +02001174}
1175
1176static int inode_ref_info(u64 inum, u64 ioff, struct btrfs_root *fs_root,
1177 struct btrfs_path *path,
1178 struct btrfs_key *found_key)
1179{
Kelley Nielsene33d5c32013-11-04 19:33:33 -08001180 return btrfs_find_item(fs_root, path, inum, ioff,
1181 BTRFS_INODE_REF_KEY, found_key);
Jan Schmidta542ad12011-06-13 19:52:59 +02001182}
1183
Mark Fashehf1863732012-08-08 11:32:27 -07001184int btrfs_find_one_extref(struct btrfs_root *root, u64 inode_objectid,
1185 u64 start_off, struct btrfs_path *path,
1186 struct btrfs_inode_extref **ret_extref,
1187 u64 *found_off)
1188{
1189 int ret, slot;
1190 struct btrfs_key key;
1191 struct btrfs_key found_key;
1192 struct btrfs_inode_extref *extref;
1193 struct extent_buffer *leaf;
1194 unsigned long ptr;
1195
1196 key.objectid = inode_objectid;
1197 btrfs_set_key_type(&key, BTRFS_INODE_EXTREF_KEY);
1198 key.offset = start_off;
1199
1200 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1201 if (ret < 0)
1202 return ret;
1203
1204 while (1) {
1205 leaf = path->nodes[0];
1206 slot = path->slots[0];
1207 if (slot >= btrfs_header_nritems(leaf)) {
1208 /*
1209 * If the item at offset is not found,
1210 * btrfs_search_slot will point us to the slot
1211 * where it should be inserted. In our case
1212 * that will be the slot directly before the
1213 * next INODE_REF_KEY_V2 item. In the case
1214 * that we're pointing to the last slot in a
1215 * leaf, we must move one leaf over.
1216 */
1217 ret = btrfs_next_leaf(root, path);
1218 if (ret) {
1219 if (ret >= 1)
1220 ret = -ENOENT;
1221 break;
1222 }
1223 continue;
1224 }
1225
1226 btrfs_item_key_to_cpu(leaf, &found_key, slot);
1227
1228 /*
1229 * Check that we're still looking at an extended ref key for
1230 * this particular objectid. If we have different
1231 * objectid or type then there are no more to be found
1232 * in the tree and we can exit.
1233 */
1234 ret = -ENOENT;
1235 if (found_key.objectid != inode_objectid)
1236 break;
1237 if (btrfs_key_type(&found_key) != BTRFS_INODE_EXTREF_KEY)
1238 break;
1239
1240 ret = 0;
1241 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
1242 extref = (struct btrfs_inode_extref *)ptr;
1243 *ret_extref = extref;
1244 if (found_off)
1245 *found_off = found_key.offset;
1246 break;
1247 }
1248
1249 return ret;
1250}
1251
Eric Sandeen48a3b632013-04-25 20:41:01 +00001252/*
1253 * this iterates to turn a name (from iref/extref) into a full filesystem path.
1254 * Elements of the path are separated by '/' and the path is guaranteed to be
1255 * 0-terminated. the path is only given within the current file system.
1256 * Therefore, it never starts with a '/'. the caller is responsible to provide
1257 * "size" bytes in "dest". the dest buffer will be filled backwards. finally,
1258 * the start point of the resulting string is returned. this pointer is within
1259 * dest, normally.
1260 * in case the path buffer would overflow, the pointer is decremented further
1261 * as if output was written to the buffer, though no more output is actually
1262 * generated. that way, the caller can determine how much space would be
1263 * required for the path to fit into the buffer. in that case, the returned
1264 * value will be smaller than dest. callers must check this!
1265 */
Jan Schmidt96b5bd72012-10-15 08:30:45 +00001266char *btrfs_ref_to_path(struct btrfs_root *fs_root, struct btrfs_path *path,
1267 u32 name_len, unsigned long name_off,
1268 struct extent_buffer *eb_in, u64 parent,
1269 char *dest, u32 size)
Jan Schmidta542ad12011-06-13 19:52:59 +02001270{
Jan Schmidta542ad12011-06-13 19:52:59 +02001271 int slot;
1272 u64 next_inum;
1273 int ret;
Gabriel de Perthuis661bec62012-10-10 08:50:47 -06001274 s64 bytes_left = ((s64)size) - 1;
Jan Schmidta542ad12011-06-13 19:52:59 +02001275 struct extent_buffer *eb = eb_in;
1276 struct btrfs_key found_key;
Jan Schmidtb916a592012-04-13 12:28:08 +02001277 int leave_spinning = path->leave_spinning;
Mark Fashehd24bec32012-08-08 11:33:54 -07001278 struct btrfs_inode_ref *iref;
Jan Schmidta542ad12011-06-13 19:52:59 +02001279
1280 if (bytes_left >= 0)
1281 dest[bytes_left] = '\0';
1282
Jan Schmidtb916a592012-04-13 12:28:08 +02001283 path->leave_spinning = 1;
Jan Schmidta542ad12011-06-13 19:52:59 +02001284 while (1) {
Mark Fashehd24bec32012-08-08 11:33:54 -07001285 bytes_left -= name_len;
Jan Schmidta542ad12011-06-13 19:52:59 +02001286 if (bytes_left >= 0)
1287 read_extent_buffer(eb, dest + bytes_left,
Mark Fashehd24bec32012-08-08 11:33:54 -07001288 name_off, name_len);
Jan Schmidtb916a592012-04-13 12:28:08 +02001289 if (eb != eb_in) {
1290 btrfs_tree_read_unlock_blocking(eb);
Jan Schmidta542ad12011-06-13 19:52:59 +02001291 free_extent_buffer(eb);
Jan Schmidtb916a592012-04-13 12:28:08 +02001292 }
Jan Schmidta542ad12011-06-13 19:52:59 +02001293 ret = inode_ref_info(parent, 0, fs_root, path, &found_key);
Jan Schmidt8f24b492012-02-08 16:01:01 +01001294 if (ret > 0)
1295 ret = -ENOENT;
Jan Schmidta542ad12011-06-13 19:52:59 +02001296 if (ret)
1297 break;
Mark Fashehd24bec32012-08-08 11:33:54 -07001298
Jan Schmidta542ad12011-06-13 19:52:59 +02001299 next_inum = found_key.offset;
1300
1301 /* regular exit ahead */
1302 if (parent == next_inum)
1303 break;
1304
1305 slot = path->slots[0];
1306 eb = path->nodes[0];
1307 /* make sure we can use eb after releasing the path */
Jan Schmidtb916a592012-04-13 12:28:08 +02001308 if (eb != eb_in) {
Jan Schmidta542ad12011-06-13 19:52:59 +02001309 atomic_inc(&eb->refs);
Jan Schmidtb916a592012-04-13 12:28:08 +02001310 btrfs_tree_read_lock(eb);
1311 btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK);
1312 }
Jan Schmidta542ad12011-06-13 19:52:59 +02001313 btrfs_release_path(path);
Jan Schmidta542ad12011-06-13 19:52:59 +02001314 iref = btrfs_item_ptr(eb, slot, struct btrfs_inode_ref);
Mark Fashehd24bec32012-08-08 11:33:54 -07001315
1316 name_len = btrfs_inode_ref_name_len(eb, iref);
1317 name_off = (unsigned long)(iref + 1);
1318
Jan Schmidta542ad12011-06-13 19:52:59 +02001319 parent = next_inum;
1320 --bytes_left;
1321 if (bytes_left >= 0)
1322 dest[bytes_left] = '/';
1323 }
1324
1325 btrfs_release_path(path);
Jan Schmidtb916a592012-04-13 12:28:08 +02001326 path->leave_spinning = leave_spinning;
Jan Schmidta542ad12011-06-13 19:52:59 +02001327
1328 if (ret)
1329 return ERR_PTR(ret);
1330
1331 return dest + bytes_left;
1332}
1333
1334/*
1335 * this makes the path point to (logical EXTENT_ITEM *)
1336 * returns BTRFS_EXTENT_FLAG_DATA for data, BTRFS_EXTENT_FLAG_TREE_BLOCK for
1337 * tree blocks and <0 on error.
1338 */
1339int extent_from_logical(struct btrfs_fs_info *fs_info, u64 logical,
Liu Bo69917e42012-09-07 20:01:28 -06001340 struct btrfs_path *path, struct btrfs_key *found_key,
1341 u64 *flags_ret)
Jan Schmidta542ad12011-06-13 19:52:59 +02001342{
1343 int ret;
1344 u64 flags;
Josef Bacik261c84b2013-06-28 13:11:22 -04001345 u64 size = 0;
Jan Schmidta542ad12011-06-13 19:52:59 +02001346 u32 item_size;
1347 struct extent_buffer *eb;
1348 struct btrfs_extent_item *ei;
1349 struct btrfs_key key;
1350
Josef Bacik261c84b2013-06-28 13:11:22 -04001351 if (btrfs_fs_incompat(fs_info, SKINNY_METADATA))
1352 key.type = BTRFS_METADATA_ITEM_KEY;
1353 else
1354 key.type = BTRFS_EXTENT_ITEM_KEY;
Jan Schmidta542ad12011-06-13 19:52:59 +02001355 key.objectid = logical;
1356 key.offset = (u64)-1;
1357
1358 ret = btrfs_search_slot(NULL, fs_info->extent_root, &key, path, 0, 0);
1359 if (ret < 0)
1360 return ret;
Jan Schmidta542ad12011-06-13 19:52:59 +02001361
Wang Shilong850a8cd2014-02-06 20:02:29 +08001362 ret = btrfs_previous_extent_item(fs_info->extent_root, path, 0);
1363 if (ret) {
1364 if (ret > 0)
1365 ret = -ENOENT;
1366 return ret;
Josef Bacik580f0a62014-01-23 16:03:45 -05001367 }
Wang Shilong850a8cd2014-02-06 20:02:29 +08001368 btrfs_item_key_to_cpu(path->nodes[0], found_key, path->slots[0]);
Josef Bacik261c84b2013-06-28 13:11:22 -04001369 if (found_key->type == BTRFS_METADATA_ITEM_KEY)
1370 size = fs_info->extent_root->leafsize;
1371 else if (found_key->type == BTRFS_EXTENT_ITEM_KEY)
1372 size = found_key->offset;
1373
Josef Bacik580f0a62014-01-23 16:03:45 -05001374 if (found_key->objectid > logical ||
Josef Bacik261c84b2013-06-28 13:11:22 -04001375 found_key->objectid + size <= logical) {
Geert Uytterhoevenc1c9ff72013-08-20 13:20:07 +02001376 pr_debug("logical %llu is not within any extent\n", logical);
Jan Schmidta542ad12011-06-13 19:52:59 +02001377 return -ENOENT;
Jan Schmidt4692cf52011-12-02 14:56:41 +01001378 }
Jan Schmidta542ad12011-06-13 19:52:59 +02001379
1380 eb = path->nodes[0];
1381 item_size = btrfs_item_size_nr(eb, path->slots[0]);
1382 BUG_ON(item_size < sizeof(*ei));
1383
1384 ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item);
1385 flags = btrfs_extent_flags(eb, ei);
1386
Jan Schmidt4692cf52011-12-02 14:56:41 +01001387 pr_debug("logical %llu is at position %llu within the extent (%llu "
1388 "EXTENT_ITEM %llu) flags %#llx size %u\n",
Geert Uytterhoevenc1c9ff72013-08-20 13:20:07 +02001389 logical, logical - found_key->objectid, found_key->objectid,
1390 found_key->offset, flags, item_size);
Liu Bo69917e42012-09-07 20:01:28 -06001391
1392 WARN_ON(!flags_ret);
1393 if (flags_ret) {
1394 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)
1395 *flags_ret = BTRFS_EXTENT_FLAG_TREE_BLOCK;
1396 else if (flags & BTRFS_EXTENT_FLAG_DATA)
1397 *flags_ret = BTRFS_EXTENT_FLAG_DATA;
1398 else
1399 BUG_ON(1);
1400 return 0;
1401 }
Jan Schmidta542ad12011-06-13 19:52:59 +02001402
1403 return -EIO;
1404}
1405
1406/*
1407 * helper function to iterate extent inline refs. ptr must point to a 0 value
1408 * for the first call and may be modified. it is used to track state.
1409 * if more refs exist, 0 is returned and the next call to
1410 * __get_extent_inline_ref must pass the modified ptr parameter to get the
1411 * next ref. after the last ref was processed, 1 is returned.
1412 * returns <0 on error
1413 */
1414static int __get_extent_inline_ref(unsigned long *ptr, struct extent_buffer *eb,
Liu Bo6eda71d2014-06-09 10:54:07 +08001415 struct btrfs_key *key,
1416 struct btrfs_extent_item *ei, u32 item_size,
1417 struct btrfs_extent_inline_ref **out_eiref,
1418 int *out_type)
Jan Schmidta542ad12011-06-13 19:52:59 +02001419{
1420 unsigned long end;
1421 u64 flags;
1422 struct btrfs_tree_block_info *info;
1423
1424 if (!*ptr) {
1425 /* first call */
1426 flags = btrfs_extent_flags(eb, ei);
1427 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
Liu Bo6eda71d2014-06-09 10:54:07 +08001428 if (key->type == BTRFS_METADATA_ITEM_KEY) {
1429 /* a skinny metadata extent */
1430 *out_eiref =
1431 (struct btrfs_extent_inline_ref *)(ei + 1);
1432 } else {
1433 WARN_ON(key->type != BTRFS_EXTENT_ITEM_KEY);
1434 info = (struct btrfs_tree_block_info *)(ei + 1);
1435 *out_eiref =
1436 (struct btrfs_extent_inline_ref *)(info + 1);
1437 }
Jan Schmidta542ad12011-06-13 19:52:59 +02001438 } else {
1439 *out_eiref = (struct btrfs_extent_inline_ref *)(ei + 1);
1440 }
1441 *ptr = (unsigned long)*out_eiref;
Liu Bocd857dd2014-06-08 19:04:13 +08001442 if ((unsigned long)(*ptr) >= (unsigned long)ei + item_size)
Jan Schmidta542ad12011-06-13 19:52:59 +02001443 return -ENOENT;
1444 }
1445
1446 end = (unsigned long)ei + item_size;
Liu Bo6eda71d2014-06-09 10:54:07 +08001447 *out_eiref = (struct btrfs_extent_inline_ref *)(*ptr);
Jan Schmidta542ad12011-06-13 19:52:59 +02001448 *out_type = btrfs_extent_inline_ref_type(eb, *out_eiref);
1449
1450 *ptr += btrfs_extent_inline_ref_size(*out_type);
1451 WARN_ON(*ptr > end);
1452 if (*ptr == end)
1453 return 1; /* last */
1454
1455 return 0;
1456}
1457
1458/*
1459 * reads the tree block backref for an extent. tree level and root are returned
1460 * through out_level and out_root. ptr must point to a 0 value for the first
1461 * call and may be modified (see __get_extent_inline_ref comment).
1462 * returns 0 if data was provided, 1 if there was no more data to provide or
1463 * <0 on error.
1464 */
1465int tree_backref_for_extent(unsigned long *ptr, struct extent_buffer *eb,
Liu Bo6eda71d2014-06-09 10:54:07 +08001466 struct btrfs_key *key, struct btrfs_extent_item *ei,
1467 u32 item_size, u64 *out_root, u8 *out_level)
Jan Schmidta542ad12011-06-13 19:52:59 +02001468{
1469 int ret;
1470 int type;
1471 struct btrfs_tree_block_info *info;
1472 struct btrfs_extent_inline_ref *eiref;
1473
1474 if (*ptr == (unsigned long)-1)
1475 return 1;
1476
1477 while (1) {
Liu Bo6eda71d2014-06-09 10:54:07 +08001478 ret = __get_extent_inline_ref(ptr, eb, key, ei, item_size,
1479 &eiref, &type);
Jan Schmidta542ad12011-06-13 19:52:59 +02001480 if (ret < 0)
1481 return ret;
1482
1483 if (type == BTRFS_TREE_BLOCK_REF_KEY ||
1484 type == BTRFS_SHARED_BLOCK_REF_KEY)
1485 break;
1486
1487 if (ret == 1)
1488 return 1;
1489 }
1490
1491 /* we can treat both ref types equally here */
1492 info = (struct btrfs_tree_block_info *)(ei + 1);
1493 *out_root = btrfs_extent_inline_ref_offset(eb, eiref);
1494 *out_level = btrfs_tree_block_level(eb, info);
1495
1496 if (ret == 1)
1497 *ptr = (unsigned long)-1;
1498
1499 return 0;
1500}
1501
Jan Schmidt976b1902012-05-17 16:43:03 +02001502static int iterate_leaf_refs(struct extent_inode_elem *inode_list,
1503 u64 root, u64 extent_item_objectid,
Jan Schmidt4692cf52011-12-02 14:56:41 +01001504 iterate_extent_inodes_t *iterate, void *ctx)
Jan Schmidta542ad12011-06-13 19:52:59 +02001505{
Jan Schmidt976b1902012-05-17 16:43:03 +02001506 struct extent_inode_elem *eie;
Jan Schmidt4692cf52011-12-02 14:56:41 +01001507 int ret = 0;
Jan Schmidta542ad12011-06-13 19:52:59 +02001508
Jan Schmidt976b1902012-05-17 16:43:03 +02001509 for (eie = inode_list; eie; eie = eie->next) {
Jan Schmidt4692cf52011-12-02 14:56:41 +01001510 pr_debug("ref for %llu resolved, key (%llu EXTEND_DATA %llu), "
Jan Schmidt976b1902012-05-17 16:43:03 +02001511 "root %llu\n", extent_item_objectid,
1512 eie->inum, eie->offset, root);
1513 ret = iterate(eie->inum, eie->offset, root, ctx);
Jan Schmidt4692cf52011-12-02 14:56:41 +01001514 if (ret) {
Jan Schmidt976b1902012-05-17 16:43:03 +02001515 pr_debug("stopping iteration for %llu due to ret=%d\n",
1516 extent_item_objectid, ret);
Jan Schmidt4692cf52011-12-02 14:56:41 +01001517 break;
1518 }
Jan Schmidta542ad12011-06-13 19:52:59 +02001519 }
1520
Jan Schmidta542ad12011-06-13 19:52:59 +02001521 return ret;
1522}
1523
1524/*
1525 * calls iterate() for every inode that references the extent identified by
Jan Schmidt4692cf52011-12-02 14:56:41 +01001526 * the given parameters.
Jan Schmidta542ad12011-06-13 19:52:59 +02001527 * when the iterator function returns a non-zero value, iteration stops.
1528 */
1529int iterate_extent_inodes(struct btrfs_fs_info *fs_info,
Jan Schmidt4692cf52011-12-02 14:56:41 +01001530 u64 extent_item_objectid, u64 extent_item_pos,
Jan Schmidt7a3ae2f2012-03-23 17:32:28 +01001531 int search_commit_root,
Jan Schmidta542ad12011-06-13 19:52:59 +02001532 iterate_extent_inodes_t *iterate, void *ctx)
1533{
Jan Schmidta542ad12011-06-13 19:52:59 +02001534 int ret;
Josef Bacikda61d312013-06-12 16:20:08 -04001535 struct btrfs_trans_handle *trans = NULL;
Jan Schmidt7a3ae2f2012-03-23 17:32:28 +01001536 struct ulist *refs = NULL;
1537 struct ulist *roots = NULL;
Jan Schmidt4692cf52011-12-02 14:56:41 +01001538 struct ulist_node *ref_node = NULL;
1539 struct ulist_node *root_node = NULL;
Jan Schmidt8445f612012-05-16 18:36:03 +02001540 struct seq_list tree_mod_seq_elem = {};
Jan Schmidtcd1b4132012-05-22 14:56:50 +02001541 struct ulist_iterator ref_uiter;
1542 struct ulist_iterator root_uiter;
Jan Schmidta542ad12011-06-13 19:52:59 +02001543
Jan Schmidt4692cf52011-12-02 14:56:41 +01001544 pr_debug("resolving all inodes for extent %llu\n",
1545 extent_item_objectid);
1546
Josef Bacikda61d312013-06-12 16:20:08 -04001547 if (!search_commit_root) {
Jan Schmidt7a3ae2f2012-03-23 17:32:28 +01001548 trans = btrfs_join_transaction(fs_info->extent_root);
1549 if (IS_ERR(trans))
1550 return PTR_ERR(trans);
Jan Schmidt8445f612012-05-16 18:36:03 +02001551 btrfs_get_tree_mod_seq(fs_info, &tree_mod_seq_elem);
Josef Bacik9e351cc2014-03-13 15:42:13 -04001552 } else {
1553 down_read(&fs_info->commit_root_sem);
Jan Schmidt7a3ae2f2012-03-23 17:32:28 +01001554 }
Jan Schmidt4692cf52011-12-02 14:56:41 +01001555
1556 ret = btrfs_find_all_leafs(trans, fs_info, extent_item_objectid,
Jan Schmidt097b8a72012-06-21 11:08:04 +02001557 tree_mod_seq_elem.seq, &refs,
Jan Schmidt8445f612012-05-16 18:36:03 +02001558 &extent_item_pos);
Jan Schmidt4692cf52011-12-02 14:56:41 +01001559 if (ret)
1560 goto out;
1561
Jan Schmidtcd1b4132012-05-22 14:56:50 +02001562 ULIST_ITER_INIT(&ref_uiter);
1563 while (!ret && (ref_node = ulist_next(refs, &ref_uiter))) {
Josef Bacik9e351cc2014-03-13 15:42:13 -04001564 ret = __btrfs_find_all_roots(trans, fs_info, ref_node->val,
1565 tree_mod_seq_elem.seq, &roots);
Jan Schmidt4692cf52011-12-02 14:56:41 +01001566 if (ret)
Jan Schmidta542ad12011-06-13 19:52:59 +02001567 break;
Jan Schmidtcd1b4132012-05-22 14:56:50 +02001568 ULIST_ITER_INIT(&root_uiter);
1569 while (!ret && (root_node = ulist_next(roots, &root_uiter))) {
Jan Schmidt976b1902012-05-17 16:43:03 +02001570 pr_debug("root %llu references leaf %llu, data list "
Alexander Block34d73f52012-07-28 16:18:58 +02001571 "%#llx\n", root_node->val, ref_node->val,
Geert Uytterhoevenc1c9ff72013-08-20 13:20:07 +02001572 ref_node->aux);
Jan Schmidt995e01b2012-08-13 02:52:38 -06001573 ret = iterate_leaf_refs((struct extent_inode_elem *)
1574 (uintptr_t)ref_node->aux,
1575 root_node->val,
1576 extent_item_objectid,
1577 iterate, ctx);
Jan Schmidta542ad12011-06-13 19:52:59 +02001578 }
Jan Schmidt976b1902012-05-17 16:43:03 +02001579 ulist_free(roots);
Jan Schmidta542ad12011-06-13 19:52:59 +02001580 }
1581
Jan Schmidt976b1902012-05-17 16:43:03 +02001582 free_leaf_list(refs);
Jan Schmidt4692cf52011-12-02 14:56:41 +01001583out:
Jan Schmidt7a3ae2f2012-03-23 17:32:28 +01001584 if (!search_commit_root) {
Jan Schmidt8445f612012-05-16 18:36:03 +02001585 btrfs_put_tree_mod_seq(fs_info, &tree_mod_seq_elem);
Jan Schmidt7a3ae2f2012-03-23 17:32:28 +01001586 btrfs_end_transaction(trans, fs_info->extent_root);
Josef Bacik9e351cc2014-03-13 15:42:13 -04001587 } else {
1588 up_read(&fs_info->commit_root_sem);
Jan Schmidt7a3ae2f2012-03-23 17:32:28 +01001589 }
1590
Jan Schmidta542ad12011-06-13 19:52:59 +02001591 return ret;
1592}
1593
1594int iterate_inodes_from_logical(u64 logical, struct btrfs_fs_info *fs_info,
1595 struct btrfs_path *path,
1596 iterate_extent_inodes_t *iterate, void *ctx)
1597{
1598 int ret;
Jan Schmidt4692cf52011-12-02 14:56:41 +01001599 u64 extent_item_pos;
Liu Bo69917e42012-09-07 20:01:28 -06001600 u64 flags = 0;
Jan Schmidta542ad12011-06-13 19:52:59 +02001601 struct btrfs_key found_key;
Jan Schmidt7a3ae2f2012-03-23 17:32:28 +01001602 int search_commit_root = path->search_commit_root;
Jan Schmidta542ad12011-06-13 19:52:59 +02001603
Liu Bo69917e42012-09-07 20:01:28 -06001604 ret = extent_from_logical(fs_info, logical, path, &found_key, &flags);
Jan Schmidt4692cf52011-12-02 14:56:41 +01001605 btrfs_release_path(path);
Jan Schmidta542ad12011-06-13 19:52:59 +02001606 if (ret < 0)
1607 return ret;
Liu Bo69917e42012-09-07 20:01:28 -06001608 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)
Stefan Behrens3627bf42012-08-01 04:28:01 -06001609 return -EINVAL;
Jan Schmidta542ad12011-06-13 19:52:59 +02001610
Jan Schmidt4692cf52011-12-02 14:56:41 +01001611 extent_item_pos = logical - found_key.objectid;
Jan Schmidt7a3ae2f2012-03-23 17:32:28 +01001612 ret = iterate_extent_inodes(fs_info, found_key.objectid,
1613 extent_item_pos, search_commit_root,
1614 iterate, ctx);
Jan Schmidta542ad12011-06-13 19:52:59 +02001615
1616 return ret;
1617}
1618
Mark Fashehd24bec32012-08-08 11:33:54 -07001619typedef int (iterate_irefs_t)(u64 parent, u32 name_len, unsigned long name_off,
1620 struct extent_buffer *eb, void *ctx);
1621
1622static int iterate_inode_refs(u64 inum, struct btrfs_root *fs_root,
1623 struct btrfs_path *path,
1624 iterate_irefs_t *iterate, void *ctx)
Jan Schmidta542ad12011-06-13 19:52:59 +02001625{
Jan Schmidtaefc1eb2012-04-13 12:28:00 +02001626 int ret = 0;
Jan Schmidta542ad12011-06-13 19:52:59 +02001627 int slot;
1628 u32 cur;
1629 u32 len;
1630 u32 name_len;
1631 u64 parent = 0;
1632 int found = 0;
1633 struct extent_buffer *eb;
1634 struct btrfs_item *item;
1635 struct btrfs_inode_ref *iref;
1636 struct btrfs_key found_key;
1637
Jan Schmidtaefc1eb2012-04-13 12:28:00 +02001638 while (!ret) {
Jan Schmidta542ad12011-06-13 19:52:59 +02001639 ret = inode_ref_info(inum, parent ? parent+1 : 0, fs_root, path,
Mark Fashehd24bec32012-08-08 11:33:54 -07001640 &found_key);
Jan Schmidta542ad12011-06-13 19:52:59 +02001641 if (ret < 0)
1642 break;
1643 if (ret) {
1644 ret = found ? 0 : -ENOENT;
1645 break;
1646 }
1647 ++found;
1648
1649 parent = found_key.offset;
1650 slot = path->slots[0];
Filipe David Borba Manana3fe81ce2013-12-15 12:43:58 +00001651 eb = btrfs_clone_extent_buffer(path->nodes[0]);
1652 if (!eb) {
1653 ret = -ENOMEM;
1654 break;
1655 }
1656 extent_buffer_get(eb);
Jan Schmidtb916a592012-04-13 12:28:08 +02001657 btrfs_tree_read_lock(eb);
1658 btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK);
Jan Schmidta542ad12011-06-13 19:52:59 +02001659 btrfs_release_path(path);
1660
Ross Kirkdd3cc162013-09-16 15:58:09 +01001661 item = btrfs_item_nr(slot);
Jan Schmidta542ad12011-06-13 19:52:59 +02001662 iref = btrfs_item_ptr(eb, slot, struct btrfs_inode_ref);
1663
1664 for (cur = 0; cur < btrfs_item_size(eb, item); cur += len) {
1665 name_len = btrfs_inode_ref_name_len(eb, iref);
1666 /* path must be released before calling iterate()! */
Jan Schmidt4692cf52011-12-02 14:56:41 +01001667 pr_debug("following ref at offset %u for inode %llu in "
Geert Uytterhoevenc1c9ff72013-08-20 13:20:07 +02001668 "tree %llu\n", cur, found_key.objectid,
1669 fs_root->objectid);
Mark Fashehd24bec32012-08-08 11:33:54 -07001670 ret = iterate(parent, name_len,
1671 (unsigned long)(iref + 1), eb, ctx);
Jan Schmidtaefc1eb2012-04-13 12:28:00 +02001672 if (ret)
Jan Schmidta542ad12011-06-13 19:52:59 +02001673 break;
Jan Schmidta542ad12011-06-13 19:52:59 +02001674 len = sizeof(*iref) + name_len;
1675 iref = (struct btrfs_inode_ref *)((char *)iref + len);
1676 }
Jan Schmidtb916a592012-04-13 12:28:08 +02001677 btrfs_tree_read_unlock_blocking(eb);
Jan Schmidta542ad12011-06-13 19:52:59 +02001678 free_extent_buffer(eb);
1679 }
1680
1681 btrfs_release_path(path);
1682
1683 return ret;
1684}
1685
Mark Fashehd24bec32012-08-08 11:33:54 -07001686static int iterate_inode_extrefs(u64 inum, struct btrfs_root *fs_root,
1687 struct btrfs_path *path,
1688 iterate_irefs_t *iterate, void *ctx)
1689{
1690 int ret;
1691 int slot;
1692 u64 offset = 0;
1693 u64 parent;
1694 int found = 0;
1695 struct extent_buffer *eb;
1696 struct btrfs_inode_extref *extref;
1697 struct extent_buffer *leaf;
1698 u32 item_size;
1699 u32 cur_offset;
1700 unsigned long ptr;
1701
1702 while (1) {
1703 ret = btrfs_find_one_extref(fs_root, inum, offset, path, &extref,
1704 &offset);
1705 if (ret < 0)
1706 break;
1707 if (ret) {
1708 ret = found ? 0 : -ENOENT;
1709 break;
1710 }
1711 ++found;
1712
1713 slot = path->slots[0];
Filipe David Borba Manana3fe81ce2013-12-15 12:43:58 +00001714 eb = btrfs_clone_extent_buffer(path->nodes[0]);
1715 if (!eb) {
1716 ret = -ENOMEM;
1717 break;
1718 }
1719 extent_buffer_get(eb);
Mark Fashehd24bec32012-08-08 11:33:54 -07001720
1721 btrfs_tree_read_lock(eb);
1722 btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK);
1723 btrfs_release_path(path);
1724
1725 leaf = path->nodes[0];
Valentina Giustie94acd82013-11-04 22:34:28 +01001726 item_size = btrfs_item_size_nr(leaf, slot);
1727 ptr = btrfs_item_ptr_offset(leaf, slot);
Mark Fashehd24bec32012-08-08 11:33:54 -07001728 cur_offset = 0;
1729
1730 while (cur_offset < item_size) {
1731 u32 name_len;
1732
1733 extref = (struct btrfs_inode_extref *)(ptr + cur_offset);
1734 parent = btrfs_inode_extref_parent(eb, extref);
1735 name_len = btrfs_inode_extref_name_len(eb, extref);
1736 ret = iterate(parent, name_len,
1737 (unsigned long)&extref->name, eb, ctx);
1738 if (ret)
1739 break;
1740
1741 cur_offset += btrfs_inode_extref_name_len(leaf, extref);
1742 cur_offset += sizeof(*extref);
1743 }
1744 btrfs_tree_read_unlock_blocking(eb);
1745 free_extent_buffer(eb);
1746
1747 offset++;
1748 }
1749
1750 btrfs_release_path(path);
1751
1752 return ret;
1753}
1754
1755static int iterate_irefs(u64 inum, struct btrfs_root *fs_root,
1756 struct btrfs_path *path, iterate_irefs_t *iterate,
1757 void *ctx)
1758{
1759 int ret;
1760 int found_refs = 0;
1761
1762 ret = iterate_inode_refs(inum, fs_root, path, iterate, ctx);
1763 if (!ret)
1764 ++found_refs;
1765 else if (ret != -ENOENT)
1766 return ret;
1767
1768 ret = iterate_inode_extrefs(inum, fs_root, path, iterate, ctx);
1769 if (ret == -ENOENT && found_refs)
1770 return 0;
1771
1772 return ret;
1773}
1774
Jan Schmidta542ad12011-06-13 19:52:59 +02001775/*
1776 * returns 0 if the path could be dumped (probably truncated)
1777 * returns <0 in case of an error
1778 */
Mark Fashehd24bec32012-08-08 11:33:54 -07001779static int inode_to_path(u64 inum, u32 name_len, unsigned long name_off,
1780 struct extent_buffer *eb, void *ctx)
Jan Schmidta542ad12011-06-13 19:52:59 +02001781{
1782 struct inode_fs_paths *ipath = ctx;
1783 char *fspath;
1784 char *fspath_min;
1785 int i = ipath->fspath->elem_cnt;
1786 const int s_ptr = sizeof(char *);
1787 u32 bytes_left;
1788
1789 bytes_left = ipath->fspath->bytes_left > s_ptr ?
1790 ipath->fspath->bytes_left - s_ptr : 0;
1791
Chris Mason740c3d22011-11-02 15:48:34 -04001792 fspath_min = (char *)ipath->fspath->val + (i + 1) * s_ptr;
Jan Schmidt96b5bd72012-10-15 08:30:45 +00001793 fspath = btrfs_ref_to_path(ipath->fs_root, ipath->btrfs_path, name_len,
1794 name_off, eb, inum, fspath_min, bytes_left);
Jan Schmidta542ad12011-06-13 19:52:59 +02001795 if (IS_ERR(fspath))
1796 return PTR_ERR(fspath);
1797
1798 if (fspath > fspath_min) {
Jeff Mahoney745c4d82011-11-20 07:31:57 -05001799 ipath->fspath->val[i] = (u64)(unsigned long)fspath;
Jan Schmidta542ad12011-06-13 19:52:59 +02001800 ++ipath->fspath->elem_cnt;
1801 ipath->fspath->bytes_left = fspath - fspath_min;
1802 } else {
1803 ++ipath->fspath->elem_missed;
1804 ipath->fspath->bytes_missing += fspath_min - fspath;
1805 ipath->fspath->bytes_left = 0;
1806 }
1807
1808 return 0;
1809}
1810
1811/*
1812 * this dumps all file system paths to the inode into the ipath struct, provided
1813 * is has been created large enough. each path is zero-terminated and accessed
Chris Mason740c3d22011-11-02 15:48:34 -04001814 * from ipath->fspath->val[i].
Jan Schmidta542ad12011-06-13 19:52:59 +02001815 * when it returns, there are ipath->fspath->elem_cnt number of paths available
Chris Mason740c3d22011-11-02 15:48:34 -04001816 * in ipath->fspath->val[]. when the allocated space wasn't sufficient, the
Jan Schmidta542ad12011-06-13 19:52:59 +02001817 * number of missed paths in recored in ipath->fspath->elem_missed, otherwise,
1818 * it's zero. ipath->fspath->bytes_missing holds the number of bytes that would
1819 * have been needed to return all paths.
1820 */
1821int paths_from_inode(u64 inum, struct inode_fs_paths *ipath)
1822{
1823 return iterate_irefs(inum, ipath->fs_root, ipath->btrfs_path,
Mark Fashehd24bec32012-08-08 11:33:54 -07001824 inode_to_path, ipath);
Jan Schmidta542ad12011-06-13 19:52:59 +02001825}
1826
Jan Schmidta542ad12011-06-13 19:52:59 +02001827struct btrfs_data_container *init_data_container(u32 total_bytes)
1828{
1829 struct btrfs_data_container *data;
1830 size_t alloc_bytes;
1831
1832 alloc_bytes = max_t(size_t, total_bytes, sizeof(*data));
Liu Bo425d17a2012-09-07 20:01:30 -06001833 data = vmalloc(alloc_bytes);
Jan Schmidta542ad12011-06-13 19:52:59 +02001834 if (!data)
1835 return ERR_PTR(-ENOMEM);
1836
1837 if (total_bytes >= sizeof(*data)) {
1838 data->bytes_left = total_bytes - sizeof(*data);
1839 data->bytes_missing = 0;
1840 } else {
1841 data->bytes_missing = sizeof(*data) - total_bytes;
1842 data->bytes_left = 0;
1843 }
1844
1845 data->elem_cnt = 0;
1846 data->elem_missed = 0;
1847
1848 return data;
1849}
1850
1851/*
1852 * allocates space to return multiple file system paths for an inode.
1853 * total_bytes to allocate are passed, note that space usable for actual path
1854 * information will be total_bytes - sizeof(struct inode_fs_paths).
1855 * the returned pointer must be freed with free_ipath() in the end.
1856 */
1857struct inode_fs_paths *init_ipath(s32 total_bytes, struct btrfs_root *fs_root,
1858 struct btrfs_path *path)
1859{
1860 struct inode_fs_paths *ifp;
1861 struct btrfs_data_container *fspath;
1862
1863 fspath = init_data_container(total_bytes);
1864 if (IS_ERR(fspath))
1865 return (void *)fspath;
1866
1867 ifp = kmalloc(sizeof(*ifp), GFP_NOFS);
1868 if (!ifp) {
1869 kfree(fspath);
1870 return ERR_PTR(-ENOMEM);
1871 }
1872
1873 ifp->btrfs_path = path;
1874 ifp->fspath = fspath;
1875 ifp->fs_root = fs_root;
1876
1877 return ifp;
1878}
1879
1880void free_ipath(struct inode_fs_paths *ipath)
1881{
Jesper Juhl4735fb22012-04-12 22:47:52 +02001882 if (!ipath)
1883 return;
Liu Bo425d17a2012-09-07 20:01:30 -06001884 vfree(ipath->fspath);
Jan Schmidta542ad12011-06-13 19:52:59 +02001885 kfree(ipath);
1886}