blob: e807b143b8578a5ed58d3f90dfeec06fa5af7f20 [file] [log] [blame]
Chris Mason56bec292009-03-13 10:10:06 -04001/*
2 * Copyright (C) 2009 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19#include <linux/sched.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090020#include <linux/slab.h>
Chris Mason56bec292009-03-13 10:10:06 -040021#include <linux/sort.h>
Chris Mason56bec292009-03-13 10:10:06 -040022#include "ctree.h"
23#include "delayed-ref.h"
24#include "transaction.h"
25
26/*
27 * delayed back reference update tracking. For subvolume trees
28 * we queue up extent allocations and backref maintenance for
29 * delayed processing. This avoids deep call chains where we
30 * add extents in the middle of btrfs_search_slot, and it allows
31 * us to buffer up frequently modified backrefs in an rb tree instead
32 * of hammering updates on the extent allocation tree.
Chris Mason56bec292009-03-13 10:10:06 -040033 */
34
35/*
Yan Zheng5d4f98a2009-06-10 10:45:14 -040036 * compare two delayed tree backrefs with same bytenr and type
Chris Mason56bec292009-03-13 10:10:06 -040037 */
Yan Zheng5d4f98a2009-06-10 10:45:14 -040038static int comp_tree_refs(struct btrfs_delayed_tree_ref *ref2,
39 struct btrfs_delayed_tree_ref *ref1)
Chris Mason56bec292009-03-13 10:10:06 -040040{
Yan Zheng5d4f98a2009-06-10 10:45:14 -040041 if (ref1->node.type == BTRFS_TREE_BLOCK_REF_KEY) {
42 if (ref1->root < ref2->root)
43 return -1;
44 if (ref1->root > ref2->root)
45 return 1;
46 } else {
47 if (ref1->parent < ref2->parent)
48 return -1;
49 if (ref1->parent > ref2->parent)
50 return 1;
51 }
52 return 0;
53}
54
55/*
56 * compare two delayed data backrefs with same bytenr and type
57 */
58static int comp_data_refs(struct btrfs_delayed_data_ref *ref2,
59 struct btrfs_delayed_data_ref *ref1)
60{
61 if (ref1->node.type == BTRFS_EXTENT_DATA_REF_KEY) {
62 if (ref1->root < ref2->root)
63 return -1;
64 if (ref1->root > ref2->root)
65 return 1;
66 if (ref1->objectid < ref2->objectid)
67 return -1;
68 if (ref1->objectid > ref2->objectid)
69 return 1;
70 if (ref1->offset < ref2->offset)
71 return -1;
72 if (ref1->offset > ref2->offset)
73 return 1;
74 } else {
75 if (ref1->parent < ref2->parent)
76 return -1;
77 if (ref1->parent > ref2->parent)
78 return 1;
79 }
80 return 0;
81}
82
83/*
84 * entries in the rb tree are ordered by the byte number of the extent,
85 * type of the delayed backrefs and content of delayed backrefs.
86 */
87static int comp_entry(struct btrfs_delayed_ref_node *ref2,
88 struct btrfs_delayed_ref_node *ref1)
89{
90 if (ref1->bytenr < ref2->bytenr)
Chris Mason56bec292009-03-13 10:10:06 -040091 return -1;
Yan Zheng5d4f98a2009-06-10 10:45:14 -040092 if (ref1->bytenr > ref2->bytenr)
Chris Mason56bec292009-03-13 10:10:06 -040093 return 1;
Yan Zheng5d4f98a2009-06-10 10:45:14 -040094 if (ref1->is_head && ref2->is_head)
95 return 0;
96 if (ref2->is_head)
Chris Mason56bec292009-03-13 10:10:06 -040097 return -1;
Yan Zheng5d4f98a2009-06-10 10:45:14 -040098 if (ref1->is_head)
Chris Mason56bec292009-03-13 10:10:06 -040099 return 1;
Yan Zheng5d4f98a2009-06-10 10:45:14 -0400100 if (ref1->type < ref2->type)
101 return -1;
102 if (ref1->type > ref2->type)
103 return 1;
104 if (ref1->type == BTRFS_TREE_BLOCK_REF_KEY ||
105 ref1->type == BTRFS_SHARED_BLOCK_REF_KEY) {
106 return comp_tree_refs(btrfs_delayed_node_to_tree_ref(ref2),
107 btrfs_delayed_node_to_tree_ref(ref1));
108 } else if (ref1->type == BTRFS_EXTENT_DATA_REF_KEY ||
109 ref1->type == BTRFS_SHARED_DATA_REF_KEY) {
110 return comp_data_refs(btrfs_delayed_node_to_data_ref(ref2),
111 btrfs_delayed_node_to_data_ref(ref1));
112 }
113 BUG();
Chris Mason56bec292009-03-13 10:10:06 -0400114 return 0;
115}
116
117/*
118 * insert a new ref into the rbtree. This returns any existing refs
119 * for the same (bytenr,parent) tuple, or NULL if the new node was properly
120 * inserted.
121 */
122static struct btrfs_delayed_ref_node *tree_insert(struct rb_root *root,
Chris Mason56bec292009-03-13 10:10:06 -0400123 struct rb_node *node)
124{
125 struct rb_node **p = &root->rb_node;
126 struct rb_node *parent_node = NULL;
127 struct btrfs_delayed_ref_node *entry;
Yan Zheng5d4f98a2009-06-10 10:45:14 -0400128 struct btrfs_delayed_ref_node *ins;
Chris Mason56bec292009-03-13 10:10:06 -0400129 int cmp;
130
Yan Zheng5d4f98a2009-06-10 10:45:14 -0400131 ins = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
Chris Mason56bec292009-03-13 10:10:06 -0400132 while (*p) {
133 parent_node = *p;
134 entry = rb_entry(parent_node, struct btrfs_delayed_ref_node,
135 rb_node);
136
Yan Zheng5d4f98a2009-06-10 10:45:14 -0400137 cmp = comp_entry(entry, ins);
Chris Mason56bec292009-03-13 10:10:06 -0400138 if (cmp < 0)
139 p = &(*p)->rb_left;
140 else if (cmp > 0)
141 p = &(*p)->rb_right;
142 else
143 return entry;
144 }
145
Chris Mason56bec292009-03-13 10:10:06 -0400146 rb_link_node(node, parent_node, p);
147 rb_insert_color(node, root);
148 return NULL;
149}
150
151/*
Yan Zheng5d4f98a2009-06-10 10:45:14 -0400152 * find an head entry based on bytenr. This returns the delayed ref
153 * head if it was able to find one, or NULL if nothing was in that spot
Chris Mason56bec292009-03-13 10:10:06 -0400154 */
Yan Zheng5d4f98a2009-06-10 10:45:14 -0400155static struct btrfs_delayed_ref_node *find_ref_head(struct rb_root *root,
156 u64 bytenr,
Chris Masonc3e69d52009-03-13 10:17:05 -0400157 struct btrfs_delayed_ref_node **last)
Chris Mason56bec292009-03-13 10:10:06 -0400158{
159 struct rb_node *n = root->rb_node;
160 struct btrfs_delayed_ref_node *entry;
161 int cmp;
162
163 while (n) {
164 entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node);
165 WARN_ON(!entry->in_tree);
Chris Masonc3e69d52009-03-13 10:17:05 -0400166 if (last)
167 *last = entry;
Chris Mason56bec292009-03-13 10:10:06 -0400168
Yan Zheng5d4f98a2009-06-10 10:45:14 -0400169 if (bytenr < entry->bytenr)
170 cmp = -1;
171 else if (bytenr > entry->bytenr)
172 cmp = 1;
173 else if (!btrfs_delayed_ref_is_head(entry))
174 cmp = 1;
175 else
176 cmp = 0;
177
Chris Mason56bec292009-03-13 10:10:06 -0400178 if (cmp < 0)
179 n = n->rb_left;
180 else if (cmp > 0)
181 n = n->rb_right;
182 else
183 return entry;
184 }
185 return NULL;
186}
187
Chris Masonc3e69d52009-03-13 10:17:05 -0400188int btrfs_delayed_ref_lock(struct btrfs_trans_handle *trans,
189 struct btrfs_delayed_ref_head *head)
Chris Mason56bec292009-03-13 10:10:06 -0400190{
Chris Masonc3e69d52009-03-13 10:17:05 -0400191 struct btrfs_delayed_ref_root *delayed_refs;
Chris Mason56bec292009-03-13 10:10:06 -0400192
Chris Masonc3e69d52009-03-13 10:17:05 -0400193 delayed_refs = &trans->transaction->delayed_refs;
194 assert_spin_locked(&delayed_refs->lock);
195 if (mutex_trylock(&head->mutex))
196 return 0;
197
198 atomic_inc(&head->node.refs);
199 spin_unlock(&delayed_refs->lock);
200
201 mutex_lock(&head->mutex);
202 spin_lock(&delayed_refs->lock);
203 if (!head->node.in_tree) {
204 mutex_unlock(&head->mutex);
205 btrfs_put_delayed_ref(&head->node);
206 return -EAGAIN;
207 }
208 btrfs_put_delayed_ref(&head->node);
209 return 0;
210}
211
212int btrfs_find_ref_cluster(struct btrfs_trans_handle *trans,
213 struct list_head *cluster, u64 start)
214{
215 int count = 0;
216 struct btrfs_delayed_ref_root *delayed_refs;
217 struct rb_node *node;
218 struct btrfs_delayed_ref_node *ref;
219 struct btrfs_delayed_ref_head *head;
220
221 delayed_refs = &trans->transaction->delayed_refs;
222 if (start == 0) {
223 node = rb_first(&delayed_refs->root);
224 } else {
225 ref = NULL;
Yan Zheng5d4f98a2009-06-10 10:45:14 -0400226 find_ref_head(&delayed_refs->root, start, &ref);
Chris Masonc3e69d52009-03-13 10:17:05 -0400227 if (ref) {
228 struct btrfs_delayed_ref_node *tmp;
229
230 node = rb_prev(&ref->rb_node);
231 while (node) {
232 tmp = rb_entry(node,
233 struct btrfs_delayed_ref_node,
234 rb_node);
235 if (tmp->bytenr < start)
236 break;
237 ref = tmp;
238 node = rb_prev(&ref->rb_node);
239 }
240 node = &ref->rb_node;
241 } else
242 node = rb_first(&delayed_refs->root);
243 }
244again:
245 while (node && count < 32) {
246 ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
Chris Mason56bec292009-03-13 10:10:06 -0400247 if (btrfs_delayed_ref_is_head(ref)) {
248 head = btrfs_delayed_node_to_head(ref);
Chris Masonc3e69d52009-03-13 10:17:05 -0400249 if (list_empty(&head->cluster)) {
250 list_add_tail(&head->cluster, cluster);
251 delayed_refs->run_delayed_start =
252 head->node.bytenr;
253 count++;
254
255 WARN_ON(delayed_refs->num_heads_ready == 0);
256 delayed_refs->num_heads_ready--;
257 } else if (count) {
258 /* the goal of the clustering is to find extents
259 * that are likely to end up in the same extent
260 * leaf on disk. So, we don't want them spread
261 * all over the tree. Stop now if we've hit
262 * a head that was already in use
263 */
Chris Mason56bec292009-03-13 10:10:06 -0400264 break;
265 }
266 }
Chris Masonc3e69d52009-03-13 10:17:05 -0400267 node = rb_next(node);
Chris Mason56bec292009-03-13 10:10:06 -0400268 }
Chris Masonc3e69d52009-03-13 10:17:05 -0400269 if (count) {
270 return 0;
271 } else if (start) {
272 /*
273 * we've gone to the end of the rbtree without finding any
274 * clusters. start from the beginning and try again
275 */
276 start = 0;
277 node = rb_first(&delayed_refs->root);
278 goto again;
279 }
280 return 1;
Chris Mason56bec292009-03-13 10:10:06 -0400281}
282
283/*
284 * This checks to see if there are any delayed refs in the
285 * btree for a given bytenr. It returns one if it finds any
286 * and zero otherwise.
287 *
288 * If it only finds a head node, it returns 0.
289 *
290 * The idea is to use this when deciding if you can safely delete an
291 * extent from the extent allocation tree. There may be a pending
292 * ref in the rbtree that adds or removes references, so as long as this
293 * returns one you need to leave the BTRFS_EXTENT_ITEM in the extent
294 * allocation tree.
295 */
296int btrfs_delayed_ref_pending(struct btrfs_trans_handle *trans, u64 bytenr)
297{
298 struct btrfs_delayed_ref_node *ref;
299 struct btrfs_delayed_ref_root *delayed_refs;
300 struct rb_node *prev_node;
301 int ret = 0;
302
303 delayed_refs = &trans->transaction->delayed_refs;
304 spin_lock(&delayed_refs->lock);
305
Yan Zheng5d4f98a2009-06-10 10:45:14 -0400306 ref = find_ref_head(&delayed_refs->root, bytenr, NULL);
Chris Mason56bec292009-03-13 10:10:06 -0400307 if (ref) {
308 prev_node = rb_prev(&ref->rb_node);
309 if (!prev_node)
310 goto out;
311 ref = rb_entry(prev_node, struct btrfs_delayed_ref_node,
312 rb_node);
313 if (ref->bytenr == bytenr)
314 ret = 1;
315 }
316out:
317 spin_unlock(&delayed_refs->lock);
318 return ret;
319}
320
321/*
Chris Mason56bec292009-03-13 10:10:06 -0400322 * helper function to update an extent delayed ref in the
323 * rbtree. existing and update must both have the same
324 * bytenr and parent
325 *
326 * This may free existing if the update cancels out whatever
327 * operation it was doing.
328 */
329static noinline void
330update_existing_ref(struct btrfs_trans_handle *trans,
331 struct btrfs_delayed_ref_root *delayed_refs,
332 struct btrfs_delayed_ref_node *existing,
333 struct btrfs_delayed_ref_node *update)
334{
Yan Zheng5d4f98a2009-06-10 10:45:14 -0400335 if (update->action != existing->action) {
Chris Mason56bec292009-03-13 10:10:06 -0400336 /*
337 * this is effectively undoing either an add or a
338 * drop. We decrement the ref_mod, and if it goes
339 * down to zero we just delete the entry without
340 * every changing the extent allocation tree.
341 */
342 existing->ref_mod--;
343 if (existing->ref_mod == 0) {
344 rb_erase(&existing->rb_node,
345 &delayed_refs->root);
346 existing->in_tree = 0;
347 btrfs_put_delayed_ref(existing);
348 delayed_refs->num_entries--;
349 if (trans->delayed_ref_updates)
350 trans->delayed_ref_updates--;
Yan Zheng5d4f98a2009-06-10 10:45:14 -0400351 } else {
352 WARN_ON(existing->type == BTRFS_TREE_BLOCK_REF_KEY ||
353 existing->type == BTRFS_SHARED_BLOCK_REF_KEY);
Chris Mason56bec292009-03-13 10:10:06 -0400354 }
355 } else {
Yan Zheng5d4f98a2009-06-10 10:45:14 -0400356 WARN_ON(existing->type == BTRFS_TREE_BLOCK_REF_KEY ||
357 existing->type == BTRFS_SHARED_BLOCK_REF_KEY);
Chris Mason56bec292009-03-13 10:10:06 -0400358 /*
359 * the action on the existing ref matches
360 * the action on the ref we're trying to add.
361 * Bump the ref_mod by one so the backref that
362 * is eventually added/removed has the correct
363 * reference count
364 */
365 existing->ref_mod += update->ref_mod;
366 }
367}
368
369/*
370 * helper function to update the accounting in the head ref
371 * existing and update must have the same bytenr
372 */
373static noinline void
374update_existing_head_ref(struct btrfs_delayed_ref_node *existing,
375 struct btrfs_delayed_ref_node *update)
376{
377 struct btrfs_delayed_ref_head *existing_ref;
378 struct btrfs_delayed_ref_head *ref;
379
380 existing_ref = btrfs_delayed_node_to_head(existing);
381 ref = btrfs_delayed_node_to_head(update);
Yan Zheng5d4f98a2009-06-10 10:45:14 -0400382 BUG_ON(existing_ref->is_data != ref->is_data);
Chris Mason56bec292009-03-13 10:10:06 -0400383
384 if (ref->must_insert_reserved) {
385 /* if the extent was freed and then
386 * reallocated before the delayed ref
387 * entries were processed, we can end up
388 * with an existing head ref without
389 * the must_insert_reserved flag set.
390 * Set it again here
391 */
392 existing_ref->must_insert_reserved = ref->must_insert_reserved;
393
394 /*
395 * update the num_bytes so we make sure the accounting
396 * is done correctly
397 */
398 existing->num_bytes = update->num_bytes;
399
400 }
401
Yan Zheng5d4f98a2009-06-10 10:45:14 -0400402 if (ref->extent_op) {
403 if (!existing_ref->extent_op) {
404 existing_ref->extent_op = ref->extent_op;
405 } else {
406 if (ref->extent_op->update_key) {
407 memcpy(&existing_ref->extent_op->key,
408 &ref->extent_op->key,
409 sizeof(ref->extent_op->key));
410 existing_ref->extent_op->update_key = 1;
411 }
412 if (ref->extent_op->update_flags) {
413 existing_ref->extent_op->flags_to_set |=
414 ref->extent_op->flags_to_set;
415 existing_ref->extent_op->update_flags = 1;
416 }
417 kfree(ref->extent_op);
418 }
419 }
Chris Mason56bec292009-03-13 10:10:06 -0400420 /*
421 * update the reference mod on the head to reflect this new operation
422 */
423 existing->ref_mod += update->ref_mod;
424}
425
426/*
Yan Zheng5d4f98a2009-06-10 10:45:14 -0400427 * helper function to actually insert a head node into the rbtree.
Chris Mason56bec292009-03-13 10:10:06 -0400428 * this does all the dirty work in terms of maintaining the correct
Yan Zheng5d4f98a2009-06-10 10:45:14 -0400429 * overall modification count.
Chris Mason56bec292009-03-13 10:10:06 -0400430 */
Yan Zheng5d4f98a2009-06-10 10:45:14 -0400431static noinline int add_delayed_ref_head(struct btrfs_trans_handle *trans,
432 struct btrfs_delayed_ref_node *ref,
433 u64 bytenr, u64 num_bytes,
434 int action, int is_data)
Chris Mason56bec292009-03-13 10:10:06 -0400435{
436 struct btrfs_delayed_ref_node *existing;
Chris Masonc3e69d52009-03-13 10:17:05 -0400437 struct btrfs_delayed_ref_head *head_ref = NULL;
Chris Mason56bec292009-03-13 10:10:06 -0400438 struct btrfs_delayed_ref_root *delayed_refs;
439 int count_mod = 1;
440 int must_insert_reserved = 0;
441
442 /*
443 * the head node stores the sum of all the mods, so dropping a ref
444 * should drop the sum in the head node by one.
445 */
Yan Zheng5d4f98a2009-06-10 10:45:14 -0400446 if (action == BTRFS_UPDATE_DELAYED_HEAD)
447 count_mod = 0;
448 else if (action == BTRFS_DROP_DELAYED_REF)
449 count_mod = -1;
Chris Mason56bec292009-03-13 10:10:06 -0400450
451 /*
452 * BTRFS_ADD_DELAYED_EXTENT means that we need to update
453 * the reserved accounting when the extent is finally added, or
454 * if a later modification deletes the delayed ref without ever
455 * inserting the extent into the extent allocation tree.
456 * ref->must_insert_reserved is the flag used to record
457 * that accounting mods are required.
458 *
459 * Once we record must_insert_reserved, switch the action to
460 * BTRFS_ADD_DELAYED_REF because other special casing is not required.
461 */
Yan Zheng5d4f98a2009-06-10 10:45:14 -0400462 if (action == BTRFS_ADD_DELAYED_EXTENT)
Chris Mason56bec292009-03-13 10:10:06 -0400463 must_insert_reserved = 1;
Yan Zheng5d4f98a2009-06-10 10:45:14 -0400464 else
Chris Mason56bec292009-03-13 10:10:06 -0400465 must_insert_reserved = 0;
Chris Mason56bec292009-03-13 10:10:06 -0400466
467 delayed_refs = &trans->transaction->delayed_refs;
468
469 /* first set the basic ref node struct up */
470 atomic_set(&ref->refs, 1);
471 ref->bytenr = bytenr;
Chris Mason56bec292009-03-13 10:10:06 -0400472 ref->num_bytes = num_bytes;
Yan Zheng5d4f98a2009-06-10 10:45:14 -0400473 ref->ref_mod = count_mod;
474 ref->type = 0;
475 ref->action = 0;
476 ref->is_head = 1;
477 ref->in_tree = 1;
Chris Mason56bec292009-03-13 10:10:06 -0400478
Yan Zheng5d4f98a2009-06-10 10:45:14 -0400479 head_ref = btrfs_delayed_node_to_head(ref);
480 head_ref->must_insert_reserved = must_insert_reserved;
481 head_ref->is_data = is_data;
Chris Mason56bec292009-03-13 10:10:06 -0400482
Yan Zheng5d4f98a2009-06-10 10:45:14 -0400483 INIT_LIST_HEAD(&head_ref->cluster);
484 mutex_init(&head_ref->mutex);
485
486 existing = tree_insert(&delayed_refs->root, &ref->rb_node);
Chris Mason56bec292009-03-13 10:10:06 -0400487
488 if (existing) {
Yan Zheng5d4f98a2009-06-10 10:45:14 -0400489 update_existing_head_ref(existing, ref);
Chris Mason56bec292009-03-13 10:10:06 -0400490 /*
491 * we've updated the existing ref, free the newly
492 * allocated ref
493 */
494 kfree(ref);
495 } else {
Yan Zheng5d4f98a2009-06-10 10:45:14 -0400496 delayed_refs->num_heads++;
497 delayed_refs->num_heads_ready++;
Chris Mason56bec292009-03-13 10:10:06 -0400498 delayed_refs->num_entries++;
499 trans->delayed_ref_updates++;
500 }
501 return 0;
502}
503
504/*
Yan Zheng5d4f98a2009-06-10 10:45:14 -0400505 * helper to insert a delayed tree ref into the rbtree.
506 */
507static noinline int add_delayed_tree_ref(struct btrfs_trans_handle *trans,
508 struct btrfs_delayed_ref_node *ref,
509 u64 bytenr, u64 num_bytes, u64 parent,
510 u64 ref_root, int level, int action)
511{
512 struct btrfs_delayed_ref_node *existing;
513 struct btrfs_delayed_tree_ref *full_ref;
514 struct btrfs_delayed_ref_root *delayed_refs;
515
516 if (action == BTRFS_ADD_DELAYED_EXTENT)
517 action = BTRFS_ADD_DELAYED_REF;
518
519 delayed_refs = &trans->transaction->delayed_refs;
520
521 /* first set the basic ref node struct up */
522 atomic_set(&ref->refs, 1);
523 ref->bytenr = bytenr;
524 ref->num_bytes = num_bytes;
525 ref->ref_mod = 1;
526 ref->action = action;
527 ref->is_head = 0;
528 ref->in_tree = 1;
529
530 full_ref = btrfs_delayed_node_to_tree_ref(ref);
531 if (parent) {
532 full_ref->parent = parent;
533 ref->type = BTRFS_SHARED_BLOCK_REF_KEY;
534 } else {
535 full_ref->root = ref_root;
536 ref->type = BTRFS_TREE_BLOCK_REF_KEY;
537 }
538 full_ref->level = level;
539
540 existing = tree_insert(&delayed_refs->root, &ref->rb_node);
541
542 if (existing) {
543 update_existing_ref(trans, delayed_refs, existing, ref);
544 /*
545 * we've updated the existing ref, free the newly
546 * allocated ref
547 */
548 kfree(ref);
549 } else {
550 delayed_refs->num_entries++;
551 trans->delayed_ref_updates++;
552 }
553 return 0;
554}
555
556/*
557 * helper to insert a delayed data ref into the rbtree.
558 */
559static noinline int add_delayed_data_ref(struct btrfs_trans_handle *trans,
560 struct btrfs_delayed_ref_node *ref,
561 u64 bytenr, u64 num_bytes, u64 parent,
562 u64 ref_root, u64 owner, u64 offset,
563 int action)
564{
565 struct btrfs_delayed_ref_node *existing;
566 struct btrfs_delayed_data_ref *full_ref;
567 struct btrfs_delayed_ref_root *delayed_refs;
568
569 if (action == BTRFS_ADD_DELAYED_EXTENT)
570 action = BTRFS_ADD_DELAYED_REF;
571
572 delayed_refs = &trans->transaction->delayed_refs;
573
574 /* first set the basic ref node struct up */
575 atomic_set(&ref->refs, 1);
576 ref->bytenr = bytenr;
577 ref->num_bytes = num_bytes;
578 ref->ref_mod = 1;
579 ref->action = action;
580 ref->is_head = 0;
581 ref->in_tree = 1;
582
583 full_ref = btrfs_delayed_node_to_data_ref(ref);
584 if (parent) {
585 full_ref->parent = parent;
586 ref->type = BTRFS_SHARED_DATA_REF_KEY;
587 } else {
588 full_ref->root = ref_root;
589 ref->type = BTRFS_EXTENT_DATA_REF_KEY;
590 }
591 full_ref->objectid = owner;
592 full_ref->offset = offset;
593
594 existing = tree_insert(&delayed_refs->root, &ref->rb_node);
595
596 if (existing) {
597 update_existing_ref(trans, delayed_refs, existing, ref);
598 /*
599 * we've updated the existing ref, free the newly
600 * allocated ref
601 */
602 kfree(ref);
603 } else {
604 delayed_refs->num_entries++;
605 trans->delayed_ref_updates++;
606 }
607 return 0;
608}
609
610/*
611 * add a delayed tree ref. This does all of the accounting required
Chris Mason56bec292009-03-13 10:10:06 -0400612 * to make sure the delayed ref is eventually processed before this
613 * transaction commits.
614 */
Yan Zheng5d4f98a2009-06-10 10:45:14 -0400615int btrfs_add_delayed_tree_ref(struct btrfs_trans_handle *trans,
616 u64 bytenr, u64 num_bytes, u64 parent,
617 u64 ref_root, int level, int action,
618 struct btrfs_delayed_extent_op *extent_op)
Chris Mason56bec292009-03-13 10:10:06 -0400619{
Yan Zheng5d4f98a2009-06-10 10:45:14 -0400620 struct btrfs_delayed_tree_ref *ref;
Chris Mason56bec292009-03-13 10:10:06 -0400621 struct btrfs_delayed_ref_head *head_ref;
622 struct btrfs_delayed_ref_root *delayed_refs;
623 int ret;
624
Yan Zheng5d4f98a2009-06-10 10:45:14 -0400625 BUG_ON(extent_op && extent_op->is_data);
Chris Mason56bec292009-03-13 10:10:06 -0400626 ref = kmalloc(sizeof(*ref), GFP_NOFS);
627 if (!ref)
628 return -ENOMEM;
629
Chris Mason56bec292009-03-13 10:10:06 -0400630 head_ref = kmalloc(sizeof(*head_ref), GFP_NOFS);
631 if (!head_ref) {
632 kfree(ref);
633 return -ENOMEM;
634 }
Yan Zheng5d4f98a2009-06-10 10:45:14 -0400635
636 head_ref->extent_op = extent_op;
637
Chris Mason56bec292009-03-13 10:10:06 -0400638 delayed_refs = &trans->transaction->delayed_refs;
639 spin_lock(&delayed_refs->lock);
640
641 /*
642 * insert both the head node and the new ref without dropping
643 * the spin lock
644 */
Yan Zheng5d4f98a2009-06-10 10:45:14 -0400645 ret = add_delayed_ref_head(trans, &head_ref->node, bytenr, num_bytes,
646 action, 0);
Chris Mason56bec292009-03-13 10:10:06 -0400647 BUG_ON(ret);
648
Yan Zheng5d4f98a2009-06-10 10:45:14 -0400649 ret = add_delayed_tree_ref(trans, &ref->node, bytenr, num_bytes,
650 parent, ref_root, level, action);
Chris Mason56bec292009-03-13 10:10:06 -0400651 BUG_ON(ret);
652 spin_unlock(&delayed_refs->lock);
653 return 0;
654}
655
656/*
Yan Zheng5d4f98a2009-06-10 10:45:14 -0400657 * add a delayed data ref. it's similar to btrfs_add_delayed_tree_ref.
658 */
659int btrfs_add_delayed_data_ref(struct btrfs_trans_handle *trans,
660 u64 bytenr, u64 num_bytes,
661 u64 parent, u64 ref_root,
662 u64 owner, u64 offset, int action,
663 struct btrfs_delayed_extent_op *extent_op)
664{
665 struct btrfs_delayed_data_ref *ref;
666 struct btrfs_delayed_ref_head *head_ref;
667 struct btrfs_delayed_ref_root *delayed_refs;
668 int ret;
669
670 BUG_ON(extent_op && !extent_op->is_data);
671 ref = kmalloc(sizeof(*ref), GFP_NOFS);
672 if (!ref)
673 return -ENOMEM;
674
675 head_ref = kmalloc(sizeof(*head_ref), GFP_NOFS);
676 if (!head_ref) {
677 kfree(ref);
678 return -ENOMEM;
679 }
680
681 head_ref->extent_op = extent_op;
682
683 delayed_refs = &trans->transaction->delayed_refs;
684 spin_lock(&delayed_refs->lock);
685
686 /*
687 * insert both the head node and the new ref without dropping
688 * the spin lock
689 */
690 ret = add_delayed_ref_head(trans, &head_ref->node, bytenr, num_bytes,
691 action, 1);
692 BUG_ON(ret);
693
694 ret = add_delayed_data_ref(trans, &ref->node, bytenr, num_bytes,
695 parent, ref_root, owner, offset, action);
696 BUG_ON(ret);
697 spin_unlock(&delayed_refs->lock);
698 return 0;
699}
700
701int btrfs_add_delayed_extent_op(struct btrfs_trans_handle *trans,
702 u64 bytenr, u64 num_bytes,
703 struct btrfs_delayed_extent_op *extent_op)
704{
705 struct btrfs_delayed_ref_head *head_ref;
706 struct btrfs_delayed_ref_root *delayed_refs;
707 int ret;
708
709 head_ref = kmalloc(sizeof(*head_ref), GFP_NOFS);
710 if (!head_ref)
711 return -ENOMEM;
712
713 head_ref->extent_op = extent_op;
714
715 delayed_refs = &trans->transaction->delayed_refs;
716 spin_lock(&delayed_refs->lock);
717
718 ret = add_delayed_ref_head(trans, &head_ref->node, bytenr,
719 num_bytes, BTRFS_UPDATE_DELAYED_HEAD,
720 extent_op->is_data);
721 BUG_ON(ret);
722
723 spin_unlock(&delayed_refs->lock);
724 return 0;
725}
726
727/*
Chris Mason1887be62009-03-13 10:11:24 -0400728 * this does a simple search for the head node for a given extent.
729 * It must be called with the delayed ref spinlock held, and it returns
730 * the head node if any where found, or NULL if not.
731 */
732struct btrfs_delayed_ref_head *
733btrfs_find_delayed_ref_head(struct btrfs_trans_handle *trans, u64 bytenr)
734{
735 struct btrfs_delayed_ref_node *ref;
736 struct btrfs_delayed_ref_root *delayed_refs;
737
738 delayed_refs = &trans->transaction->delayed_refs;
Yan Zheng5d4f98a2009-06-10 10:45:14 -0400739 ref = find_ref_head(&delayed_refs->root, bytenr, NULL);
Chris Mason1887be62009-03-13 10:11:24 -0400740 if (ref)
741 return btrfs_delayed_node_to_head(ref);
742 return NULL;
743}
744
745/*
Chris Mason56bec292009-03-13 10:10:06 -0400746 * add a delayed ref to the tree. This does all of the accounting required
747 * to make sure the delayed ref is eventually processed before this
748 * transaction commits.
749 *
750 * The main point of this call is to add and remove a backreference in a single
751 * shot, taking the lock only once, and only searching for the head node once.
752 *
753 * It is the same as doing a ref add and delete in two separate calls.
754 */
Yan Zheng5d4f98a2009-06-10 10:45:14 -0400755#if 0
Chris Mason56bec292009-03-13 10:10:06 -0400756int btrfs_update_delayed_ref(struct btrfs_trans_handle *trans,
757 u64 bytenr, u64 num_bytes, u64 orig_parent,
758 u64 parent, u64 orig_ref_root, u64 ref_root,
759 u64 orig_ref_generation, u64 ref_generation,
760 u64 owner_objectid, int pin)
761{
762 struct btrfs_delayed_ref *ref;
763 struct btrfs_delayed_ref *old_ref;
764 struct btrfs_delayed_ref_head *head_ref;
765 struct btrfs_delayed_ref_root *delayed_refs;
766 int ret;
767
768 ref = kmalloc(sizeof(*ref), GFP_NOFS);
769 if (!ref)
770 return -ENOMEM;
771
772 old_ref = kmalloc(sizeof(*old_ref), GFP_NOFS);
773 if (!old_ref) {
774 kfree(ref);
775 return -ENOMEM;
776 }
777
778 /*
779 * the parent = 0 case comes from cases where we don't actually
780 * know the parent yet. It will get updated later via a add/drop
781 * pair.
782 */
783 if (parent == 0)
784 parent = bytenr;
785 if (orig_parent == 0)
786 orig_parent = bytenr;
787
788 head_ref = kmalloc(sizeof(*head_ref), GFP_NOFS);
789 if (!head_ref) {
790 kfree(ref);
791 kfree(old_ref);
792 return -ENOMEM;
793 }
794 delayed_refs = &trans->transaction->delayed_refs;
795 spin_lock(&delayed_refs->lock);
796
797 /*
798 * insert both the head node and the new ref without dropping
799 * the spin lock
800 */
801 ret = __btrfs_add_delayed_ref(trans, &head_ref->node, bytenr, num_bytes,
802 (u64)-1, 0, 0, 0,
Chris Mason1a81af42009-03-25 09:55:11 -0400803 BTRFS_UPDATE_DELAYED_HEAD, 0);
Chris Mason56bec292009-03-13 10:10:06 -0400804 BUG_ON(ret);
805
806 ret = __btrfs_add_delayed_ref(trans, &ref->node, bytenr, num_bytes,
807 parent, ref_root, ref_generation,
808 owner_objectid, BTRFS_ADD_DELAYED_REF, 0);
809 BUG_ON(ret);
810
811 ret = __btrfs_add_delayed_ref(trans, &old_ref->node, bytenr, num_bytes,
812 orig_parent, orig_ref_root,
813 orig_ref_generation, owner_objectid,
814 BTRFS_DROP_DELAYED_REF, pin);
815 BUG_ON(ret);
816 spin_unlock(&delayed_refs->lock);
817 return 0;
818}
Yan Zheng5d4f98a2009-06-10 10:45:14 -0400819#endif