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56bec294 CM |
1 | /* |
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> | |
5a0e3ad6 | 20 | #include <linux/slab.h> |
56bec294 | 21 | #include <linux/sort.h> |
56bec294 CM |
22 | #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. | |
56bec294 CM |
33 | */ |
34 | ||
35 | /* | |
5d4f98a2 YZ |
36 | * compare two delayed tree backrefs with same bytenr and type |
37 | */ | |
38 | static int comp_tree_refs(struct btrfs_delayed_tree_ref *ref2, | |
39 | struct btrfs_delayed_tree_ref *ref1) | |
40 | { | |
41 | 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 | |
56bec294 | 57 | */ |
5d4f98a2 YZ |
58 | static int comp_data_refs(struct btrfs_delayed_data_ref *ref2, |
59 | struct btrfs_delayed_data_ref *ref1) | |
56bec294 | 60 | { |
5d4f98a2 YZ |
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 | */ | |
87 | static int comp_entry(struct btrfs_delayed_ref_node *ref2, | |
88 | struct btrfs_delayed_ref_node *ref1) | |
89 | { | |
90 | if (ref1->bytenr < ref2->bytenr) | |
56bec294 | 91 | return -1; |
5d4f98a2 | 92 | if (ref1->bytenr > ref2->bytenr) |
56bec294 | 93 | return 1; |
5d4f98a2 YZ |
94 | if (ref1->is_head && ref2->is_head) |
95 | return 0; | |
96 | if (ref2->is_head) | |
56bec294 | 97 | return -1; |
5d4f98a2 | 98 | if (ref1->is_head) |
56bec294 | 99 | return 1; |
5d4f98a2 YZ |
100 | 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(); | |
56bec294 CM |
114 | 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 | */ | |
122 | static struct btrfs_delayed_ref_node *tree_insert(struct rb_root *root, | |
56bec294 CM |
123 | 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; | |
5d4f98a2 | 128 | struct btrfs_delayed_ref_node *ins; |
56bec294 CM |
129 | int cmp; |
130 | ||
5d4f98a2 | 131 | ins = rb_entry(node, struct btrfs_delayed_ref_node, rb_node); |
56bec294 CM |
132 | while (*p) { |
133 | parent_node = *p; | |
134 | entry = rb_entry(parent_node, struct btrfs_delayed_ref_node, | |
135 | rb_node); | |
136 | ||
5d4f98a2 | 137 | cmp = comp_entry(entry, ins); |
56bec294 CM |
138 | 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 | ||
56bec294 CM |
146 | rb_link_node(node, parent_node, p); |
147 | rb_insert_color(node, root); | |
148 | return NULL; | |
149 | } | |
150 | ||
151 | /* | |
5d4f98a2 YZ |
152 | * 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 | |
56bec294 | 154 | */ |
5d4f98a2 YZ |
155 | static struct btrfs_delayed_ref_node *find_ref_head(struct rb_root *root, |
156 | u64 bytenr, | |
c3e69d58 | 157 | struct btrfs_delayed_ref_node **last) |
56bec294 CM |
158 | { |
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); | |
c3e69d58 CM |
166 | if (last) |
167 | *last = entry; | |
56bec294 | 168 | |
5d4f98a2 YZ |
169 | 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 | ||
56bec294 CM |
178 | 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 | ||
c3e69d58 CM |
188 | int btrfs_delayed_ref_lock(struct btrfs_trans_handle *trans, |
189 | struct btrfs_delayed_ref_head *head) | |
56bec294 | 190 | { |
c3e69d58 CM |
191 | struct btrfs_delayed_ref_root *delayed_refs; |
192 | ||
193 | 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 | ||
212 | int 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; | |
56bec294 | 217 | struct rb_node *node; |
c3e69d58 | 218 | struct btrfs_delayed_ref_node *ref; |
56bec294 | 219 | struct btrfs_delayed_ref_head *head; |
56bec294 | 220 | |
c3e69d58 CM |
221 | delayed_refs = &trans->transaction->delayed_refs; |
222 | if (start == 0) { | |
223 | node = rb_first(&delayed_refs->root); | |
224 | } else { | |
225 | ref = NULL; | |
5d4f98a2 | 226 | find_ref_head(&delayed_refs->root, start, &ref); |
c3e69d58 CM |
227 | 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 | } | |
244 | again: | |
245 | while (node && count < 32) { | |
246 | ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node); | |
56bec294 CM |
247 | if (btrfs_delayed_ref_is_head(ref)) { |
248 | head = btrfs_delayed_node_to_head(ref); | |
c3e69d58 CM |
249 | 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 | */ | |
56bec294 CM |
264 | break; |
265 | } | |
266 | } | |
c3e69d58 | 267 | node = rb_next(node); |
56bec294 | 268 | } |
c3e69d58 CM |
269 | 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; | |
56bec294 CM |
281 | } |
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 | */ | |
296 | int 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 | ||
5d4f98a2 | 306 | ref = find_ref_head(&delayed_refs->root, bytenr, NULL); |
56bec294 CM |
307 | 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 | } | |
316 | out: | |
317 | spin_unlock(&delayed_refs->lock); | |
318 | return ret; | |
319 | } | |
320 | ||
321 | /* | |
5d4f98a2 | 322 | * helper function to lookup reference count and flags of extent. |
56bec294 CM |
323 | * |
324 | * the head node for delayed ref is used to store the sum of all the | |
5d4f98a2 YZ |
325 | * reference count modifications queued up in the rbtree. the head |
326 | * node may also store the extent flags to set. This way you can check | |
327 | * to see what the reference count and extent flags would be if all of | |
328 | * the delayed refs are not processed. | |
56bec294 | 329 | */ |
5d4f98a2 YZ |
330 | int btrfs_lookup_extent_info(struct btrfs_trans_handle *trans, |
331 | struct btrfs_root *root, u64 bytenr, | |
332 | u64 num_bytes, u64 *refs, u64 *flags) | |
56bec294 CM |
333 | { |
334 | struct btrfs_delayed_ref_node *ref; | |
335 | struct btrfs_delayed_ref_head *head; | |
336 | struct btrfs_delayed_ref_root *delayed_refs; | |
337 | struct btrfs_path *path; | |
56bec294 | 338 | struct btrfs_extent_item *ei; |
5d4f98a2 | 339 | struct extent_buffer *leaf; |
56bec294 | 340 | struct btrfs_key key; |
5d4f98a2 YZ |
341 | u32 item_size; |
342 | u64 num_refs; | |
343 | u64 extent_flags; | |
56bec294 CM |
344 | int ret; |
345 | ||
346 | path = btrfs_alloc_path(); | |
347 | if (!path) | |
348 | return -ENOMEM; | |
349 | ||
350 | key.objectid = bytenr; | |
351 | key.type = BTRFS_EXTENT_ITEM_KEY; | |
352 | key.offset = num_bytes; | |
353 | delayed_refs = &trans->transaction->delayed_refs; | |
354 | again: | |
355 | ret = btrfs_search_slot(trans, root->fs_info->extent_root, | |
356 | &key, path, 0, 0); | |
357 | if (ret < 0) | |
358 | goto out; | |
359 | ||
360 | if (ret == 0) { | |
361 | leaf = path->nodes[0]; | |
5d4f98a2 YZ |
362 | item_size = btrfs_item_size_nr(leaf, path->slots[0]); |
363 | if (item_size >= sizeof(*ei)) { | |
364 | ei = btrfs_item_ptr(leaf, path->slots[0], | |
365 | struct btrfs_extent_item); | |
366 | num_refs = btrfs_extent_refs(leaf, ei); | |
367 | extent_flags = btrfs_extent_flags(leaf, ei); | |
368 | } else { | |
369 | #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 | |
370 | struct btrfs_extent_item_v0 *ei0; | |
371 | BUG_ON(item_size != sizeof(*ei0)); | |
372 | ei0 = btrfs_item_ptr(leaf, path->slots[0], | |
373 | struct btrfs_extent_item_v0); | |
374 | num_refs = btrfs_extent_refs_v0(leaf, ei0); | |
375 | /* FIXME: this isn't correct for data */ | |
376 | extent_flags = BTRFS_BLOCK_FLAG_FULL_BACKREF; | |
377 | #else | |
378 | BUG(); | |
379 | #endif | |
380 | } | |
381 | BUG_ON(num_refs == 0); | |
56bec294 CM |
382 | } else { |
383 | num_refs = 0; | |
5d4f98a2 | 384 | extent_flags = 0; |
56bec294 CM |
385 | ret = 0; |
386 | } | |
387 | ||
388 | spin_lock(&delayed_refs->lock); | |
5d4f98a2 | 389 | ref = find_ref_head(&delayed_refs->root, bytenr, NULL); |
56bec294 CM |
390 | if (ref) { |
391 | head = btrfs_delayed_node_to_head(ref); | |
5d4f98a2 YZ |
392 | if (!mutex_trylock(&head->mutex)) { |
393 | atomic_inc(&ref->refs); | |
394 | spin_unlock(&delayed_refs->lock); | |
56bec294 | 395 | |
5d4f98a2 | 396 | btrfs_release_path(root->fs_info->extent_root, path); |
56bec294 | 397 | |
5d4f98a2 YZ |
398 | mutex_lock(&head->mutex); |
399 | mutex_unlock(&head->mutex); | |
400 | btrfs_put_delayed_ref(ref); | |
401 | goto again; | |
402 | } | |
403 | if (head->extent_op && head->extent_op->update_flags) | |
404 | extent_flags |= head->extent_op->flags_to_set; | |
405 | else | |
406 | BUG_ON(num_refs == 0); | |
56bec294 | 407 | |
5d4f98a2 | 408 | num_refs += ref->ref_mod; |
56bec294 | 409 | mutex_unlock(&head->mutex); |
56bec294 | 410 | } |
5d4f98a2 YZ |
411 | WARN_ON(num_refs == 0); |
412 | if (refs) | |
413 | *refs = num_refs; | |
414 | if (flags) | |
415 | *flags = extent_flags; | |
56bec294 CM |
416 | out: |
417 | spin_unlock(&delayed_refs->lock); | |
418 | btrfs_free_path(path); | |
419 | return ret; | |
420 | } | |
421 | ||
422 | /* | |
423 | * helper function to update an extent delayed ref in the | |
424 | * rbtree. existing and update must both have the same | |
425 | * bytenr and parent | |
426 | * | |
427 | * This may free existing if the update cancels out whatever | |
428 | * operation it was doing. | |
429 | */ | |
430 | static noinline void | |
431 | update_existing_ref(struct btrfs_trans_handle *trans, | |
432 | struct btrfs_delayed_ref_root *delayed_refs, | |
433 | struct btrfs_delayed_ref_node *existing, | |
434 | struct btrfs_delayed_ref_node *update) | |
435 | { | |
5d4f98a2 | 436 | if (update->action != existing->action) { |
56bec294 CM |
437 | /* |
438 | * this is effectively undoing either an add or a | |
439 | * drop. We decrement the ref_mod, and if it goes | |
440 | * down to zero we just delete the entry without | |
441 | * every changing the extent allocation tree. | |
442 | */ | |
443 | existing->ref_mod--; | |
444 | if (existing->ref_mod == 0) { | |
445 | rb_erase(&existing->rb_node, | |
446 | &delayed_refs->root); | |
447 | existing->in_tree = 0; | |
448 | btrfs_put_delayed_ref(existing); | |
449 | delayed_refs->num_entries--; | |
450 | if (trans->delayed_ref_updates) | |
451 | trans->delayed_ref_updates--; | |
5d4f98a2 YZ |
452 | } else { |
453 | WARN_ON(existing->type == BTRFS_TREE_BLOCK_REF_KEY || | |
454 | existing->type == BTRFS_SHARED_BLOCK_REF_KEY); | |
56bec294 CM |
455 | } |
456 | } else { | |
5d4f98a2 YZ |
457 | WARN_ON(existing->type == BTRFS_TREE_BLOCK_REF_KEY || |
458 | existing->type == BTRFS_SHARED_BLOCK_REF_KEY); | |
56bec294 CM |
459 | /* |
460 | * the action on the existing ref matches | |
461 | * the action on the ref we're trying to add. | |
462 | * Bump the ref_mod by one so the backref that | |
463 | * is eventually added/removed has the correct | |
464 | * reference count | |
465 | */ | |
466 | existing->ref_mod += update->ref_mod; | |
467 | } | |
468 | } | |
469 | ||
470 | /* | |
471 | * helper function to update the accounting in the head ref | |
472 | * existing and update must have the same bytenr | |
473 | */ | |
474 | static noinline void | |
475 | update_existing_head_ref(struct btrfs_delayed_ref_node *existing, | |
476 | struct btrfs_delayed_ref_node *update) | |
477 | { | |
478 | struct btrfs_delayed_ref_head *existing_ref; | |
479 | struct btrfs_delayed_ref_head *ref; | |
480 | ||
481 | existing_ref = btrfs_delayed_node_to_head(existing); | |
482 | ref = btrfs_delayed_node_to_head(update); | |
5d4f98a2 | 483 | BUG_ON(existing_ref->is_data != ref->is_data); |
56bec294 CM |
484 | |
485 | if (ref->must_insert_reserved) { | |
486 | /* if the extent was freed and then | |
487 | * reallocated before the delayed ref | |
488 | * entries were processed, we can end up | |
489 | * with an existing head ref without | |
490 | * the must_insert_reserved flag set. | |
491 | * Set it again here | |
492 | */ | |
493 | existing_ref->must_insert_reserved = ref->must_insert_reserved; | |
494 | ||
495 | /* | |
496 | * update the num_bytes so we make sure the accounting | |
497 | * is done correctly | |
498 | */ | |
499 | existing->num_bytes = update->num_bytes; | |
500 | ||
501 | } | |
502 | ||
5d4f98a2 YZ |
503 | if (ref->extent_op) { |
504 | if (!existing_ref->extent_op) { | |
505 | existing_ref->extent_op = ref->extent_op; | |
506 | } else { | |
507 | if (ref->extent_op->update_key) { | |
508 | memcpy(&existing_ref->extent_op->key, | |
509 | &ref->extent_op->key, | |
510 | sizeof(ref->extent_op->key)); | |
511 | existing_ref->extent_op->update_key = 1; | |
512 | } | |
513 | if (ref->extent_op->update_flags) { | |
514 | existing_ref->extent_op->flags_to_set |= | |
515 | ref->extent_op->flags_to_set; | |
516 | existing_ref->extent_op->update_flags = 1; | |
517 | } | |
518 | kfree(ref->extent_op); | |
519 | } | |
520 | } | |
56bec294 CM |
521 | /* |
522 | * update the reference mod on the head to reflect this new operation | |
523 | */ | |
524 | existing->ref_mod += update->ref_mod; | |
525 | } | |
526 | ||
527 | /* | |
5d4f98a2 | 528 | * helper function to actually insert a head node into the rbtree. |
56bec294 | 529 | * this does all the dirty work in terms of maintaining the correct |
5d4f98a2 | 530 | * overall modification count. |
56bec294 | 531 | */ |
5d4f98a2 YZ |
532 | static noinline int add_delayed_ref_head(struct btrfs_trans_handle *trans, |
533 | struct btrfs_delayed_ref_node *ref, | |
534 | u64 bytenr, u64 num_bytes, | |
535 | int action, int is_data) | |
56bec294 CM |
536 | { |
537 | struct btrfs_delayed_ref_node *existing; | |
c3e69d58 | 538 | struct btrfs_delayed_ref_head *head_ref = NULL; |
56bec294 CM |
539 | struct btrfs_delayed_ref_root *delayed_refs; |
540 | int count_mod = 1; | |
541 | int must_insert_reserved = 0; | |
542 | ||
543 | /* | |
544 | * the head node stores the sum of all the mods, so dropping a ref | |
545 | * should drop the sum in the head node by one. | |
546 | */ | |
5d4f98a2 YZ |
547 | if (action == BTRFS_UPDATE_DELAYED_HEAD) |
548 | count_mod = 0; | |
549 | else if (action == BTRFS_DROP_DELAYED_REF) | |
550 | count_mod = -1; | |
56bec294 CM |
551 | |
552 | /* | |
553 | * BTRFS_ADD_DELAYED_EXTENT means that we need to update | |
554 | * the reserved accounting when the extent is finally added, or | |
555 | * if a later modification deletes the delayed ref without ever | |
556 | * inserting the extent into the extent allocation tree. | |
557 | * ref->must_insert_reserved is the flag used to record | |
558 | * that accounting mods are required. | |
559 | * | |
560 | * Once we record must_insert_reserved, switch the action to | |
561 | * BTRFS_ADD_DELAYED_REF because other special casing is not required. | |
562 | */ | |
5d4f98a2 | 563 | if (action == BTRFS_ADD_DELAYED_EXTENT) |
56bec294 | 564 | must_insert_reserved = 1; |
5d4f98a2 | 565 | else |
56bec294 | 566 | must_insert_reserved = 0; |
56bec294 CM |
567 | |
568 | delayed_refs = &trans->transaction->delayed_refs; | |
569 | ||
570 | /* first set the basic ref node struct up */ | |
571 | atomic_set(&ref->refs, 1); | |
572 | ref->bytenr = bytenr; | |
5d4f98a2 | 573 | ref->num_bytes = num_bytes; |
56bec294 | 574 | ref->ref_mod = count_mod; |
5d4f98a2 YZ |
575 | ref->type = 0; |
576 | ref->action = 0; | |
577 | ref->is_head = 1; | |
56bec294 | 578 | ref->in_tree = 1; |
5d4f98a2 YZ |
579 | |
580 | head_ref = btrfs_delayed_node_to_head(ref); | |
581 | head_ref->must_insert_reserved = must_insert_reserved; | |
582 | head_ref->is_data = is_data; | |
583 | ||
584 | INIT_LIST_HEAD(&head_ref->cluster); | |
585 | mutex_init(&head_ref->mutex); | |
586 | ||
587 | existing = tree_insert(&delayed_refs->root, &ref->rb_node); | |
588 | ||
589 | if (existing) { | |
590 | update_existing_head_ref(existing, ref); | |
591 | /* | |
592 | * we've updated the existing ref, free the newly | |
593 | * allocated ref | |
594 | */ | |
595 | kfree(ref); | |
596 | } else { | |
597 | delayed_refs->num_heads++; | |
598 | delayed_refs->num_heads_ready++; | |
599 | delayed_refs->num_entries++; | |
600 | trans->delayed_ref_updates++; | |
601 | } | |
602 | return 0; | |
603 | } | |
604 | ||
605 | /* | |
606 | * helper to insert a delayed tree ref into the rbtree. | |
607 | */ | |
608 | static noinline int add_delayed_tree_ref(struct btrfs_trans_handle *trans, | |
609 | struct btrfs_delayed_ref_node *ref, | |
610 | u64 bytenr, u64 num_bytes, u64 parent, | |
611 | u64 ref_root, int level, int action) | |
612 | { | |
613 | struct btrfs_delayed_ref_node *existing; | |
614 | struct btrfs_delayed_tree_ref *full_ref; | |
615 | struct btrfs_delayed_ref_root *delayed_refs; | |
616 | ||
617 | if (action == BTRFS_ADD_DELAYED_EXTENT) | |
618 | action = BTRFS_ADD_DELAYED_REF; | |
619 | ||
620 | delayed_refs = &trans->transaction->delayed_refs; | |
621 | ||
622 | /* first set the basic ref node struct up */ | |
623 | atomic_set(&ref->refs, 1); | |
624 | ref->bytenr = bytenr; | |
56bec294 | 625 | ref->num_bytes = num_bytes; |
5d4f98a2 YZ |
626 | ref->ref_mod = 1; |
627 | ref->action = action; | |
628 | ref->is_head = 0; | |
629 | ref->in_tree = 1; | |
56bec294 | 630 | |
5d4f98a2 YZ |
631 | full_ref = btrfs_delayed_node_to_tree_ref(ref); |
632 | if (parent) { | |
633 | full_ref->parent = parent; | |
634 | ref->type = BTRFS_SHARED_BLOCK_REF_KEY; | |
56bec294 | 635 | } else { |
56bec294 | 636 | full_ref->root = ref_root; |
5d4f98a2 | 637 | ref->type = BTRFS_TREE_BLOCK_REF_KEY; |
56bec294 | 638 | } |
5d4f98a2 | 639 | full_ref->level = level; |
56bec294 | 640 | |
5d4f98a2 | 641 | existing = tree_insert(&delayed_refs->root, &ref->rb_node); |
56bec294 CM |
642 | |
643 | if (existing) { | |
5d4f98a2 YZ |
644 | update_existing_ref(trans, delayed_refs, existing, ref); |
645 | /* | |
646 | * we've updated the existing ref, free the newly | |
647 | * allocated ref | |
648 | */ | |
649 | kfree(ref); | |
650 | } else { | |
651 | delayed_refs->num_entries++; | |
652 | trans->delayed_ref_updates++; | |
653 | } | |
654 | return 0; | |
655 | } | |
656 | ||
657 | /* | |
658 | * helper to insert a delayed data ref into the rbtree. | |
659 | */ | |
660 | static noinline int add_delayed_data_ref(struct btrfs_trans_handle *trans, | |
661 | struct btrfs_delayed_ref_node *ref, | |
662 | u64 bytenr, u64 num_bytes, u64 parent, | |
663 | u64 ref_root, u64 owner, u64 offset, | |
664 | int action) | |
665 | { | |
666 | struct btrfs_delayed_ref_node *existing; | |
667 | struct btrfs_delayed_data_ref *full_ref; | |
668 | struct btrfs_delayed_ref_root *delayed_refs; | |
669 | ||
670 | if (action == BTRFS_ADD_DELAYED_EXTENT) | |
671 | action = BTRFS_ADD_DELAYED_REF; | |
672 | ||
673 | delayed_refs = &trans->transaction->delayed_refs; | |
674 | ||
675 | /* first set the basic ref node struct up */ | |
676 | atomic_set(&ref->refs, 1); | |
677 | ref->bytenr = bytenr; | |
678 | ref->num_bytes = num_bytes; | |
679 | ref->ref_mod = 1; | |
680 | ref->action = action; | |
681 | ref->is_head = 0; | |
682 | ref->in_tree = 1; | |
683 | ||
684 | full_ref = btrfs_delayed_node_to_data_ref(ref); | |
685 | if (parent) { | |
686 | full_ref->parent = parent; | |
687 | ref->type = BTRFS_SHARED_DATA_REF_KEY; | |
688 | } else { | |
689 | full_ref->root = ref_root; | |
690 | ref->type = BTRFS_EXTENT_DATA_REF_KEY; | |
691 | } | |
692 | full_ref->objectid = owner; | |
693 | full_ref->offset = offset; | |
56bec294 | 694 | |
5d4f98a2 YZ |
695 | existing = tree_insert(&delayed_refs->root, &ref->rb_node); |
696 | ||
697 | if (existing) { | |
698 | update_existing_ref(trans, delayed_refs, existing, ref); | |
56bec294 CM |
699 | /* |
700 | * we've updated the existing ref, free the newly | |
701 | * allocated ref | |
702 | */ | |
703 | kfree(ref); | |
704 | } else { | |
705 | delayed_refs->num_entries++; | |
706 | trans->delayed_ref_updates++; | |
707 | } | |
708 | return 0; | |
709 | } | |
710 | ||
711 | /* | |
5d4f98a2 | 712 | * add a delayed tree ref. This does all of the accounting required |
56bec294 CM |
713 | * to make sure the delayed ref is eventually processed before this |
714 | * transaction commits. | |
715 | */ | |
5d4f98a2 YZ |
716 | int btrfs_add_delayed_tree_ref(struct btrfs_trans_handle *trans, |
717 | u64 bytenr, u64 num_bytes, u64 parent, | |
718 | u64 ref_root, int level, int action, | |
719 | struct btrfs_delayed_extent_op *extent_op) | |
56bec294 | 720 | { |
5d4f98a2 | 721 | struct btrfs_delayed_tree_ref *ref; |
56bec294 CM |
722 | struct btrfs_delayed_ref_head *head_ref; |
723 | struct btrfs_delayed_ref_root *delayed_refs; | |
724 | int ret; | |
725 | ||
5d4f98a2 | 726 | BUG_ON(extent_op && extent_op->is_data); |
56bec294 CM |
727 | ref = kmalloc(sizeof(*ref), GFP_NOFS); |
728 | if (!ref) | |
729 | return -ENOMEM; | |
730 | ||
5d4f98a2 YZ |
731 | head_ref = kmalloc(sizeof(*head_ref), GFP_NOFS); |
732 | if (!head_ref) { | |
733 | kfree(ref); | |
734 | return -ENOMEM; | |
735 | } | |
736 | ||
737 | head_ref->extent_op = extent_op; | |
738 | ||
739 | delayed_refs = &trans->transaction->delayed_refs; | |
740 | spin_lock(&delayed_refs->lock); | |
741 | ||
56bec294 | 742 | /* |
5d4f98a2 YZ |
743 | * insert both the head node and the new ref without dropping |
744 | * the spin lock | |
56bec294 | 745 | */ |
5d4f98a2 YZ |
746 | ret = add_delayed_ref_head(trans, &head_ref->node, bytenr, num_bytes, |
747 | action, 0); | |
748 | BUG_ON(ret); | |
749 | ||
750 | ret = add_delayed_tree_ref(trans, &ref->node, bytenr, num_bytes, | |
751 | parent, ref_root, level, action); | |
752 | BUG_ON(ret); | |
753 | spin_unlock(&delayed_refs->lock); | |
754 | return 0; | |
755 | } | |
756 | ||
757 | /* | |
758 | * add a delayed data ref. it's similar to btrfs_add_delayed_tree_ref. | |
759 | */ | |
760 | int btrfs_add_delayed_data_ref(struct btrfs_trans_handle *trans, | |
761 | u64 bytenr, u64 num_bytes, | |
762 | u64 parent, u64 ref_root, | |
763 | u64 owner, u64 offset, int action, | |
764 | struct btrfs_delayed_extent_op *extent_op) | |
765 | { | |
766 | struct btrfs_delayed_data_ref *ref; | |
767 | struct btrfs_delayed_ref_head *head_ref; | |
768 | struct btrfs_delayed_ref_root *delayed_refs; | |
769 | int ret; | |
770 | ||
771 | BUG_ON(extent_op && !extent_op->is_data); | |
772 | ref = kmalloc(sizeof(*ref), GFP_NOFS); | |
773 | if (!ref) | |
774 | return -ENOMEM; | |
56bec294 CM |
775 | |
776 | head_ref = kmalloc(sizeof(*head_ref), GFP_NOFS); | |
777 | if (!head_ref) { | |
778 | kfree(ref); | |
779 | return -ENOMEM; | |
780 | } | |
5d4f98a2 YZ |
781 | |
782 | head_ref->extent_op = extent_op; | |
783 | ||
56bec294 CM |
784 | delayed_refs = &trans->transaction->delayed_refs; |
785 | spin_lock(&delayed_refs->lock); | |
786 | ||
787 | /* | |
788 | * insert both the head node and the new ref without dropping | |
789 | * the spin lock | |
790 | */ | |
5d4f98a2 YZ |
791 | ret = add_delayed_ref_head(trans, &head_ref->node, bytenr, num_bytes, |
792 | action, 1); | |
56bec294 CM |
793 | BUG_ON(ret); |
794 | ||
5d4f98a2 YZ |
795 | ret = add_delayed_data_ref(trans, &ref->node, bytenr, num_bytes, |
796 | parent, ref_root, owner, offset, action); | |
797 | BUG_ON(ret); | |
798 | spin_unlock(&delayed_refs->lock); | |
799 | return 0; | |
800 | } | |
801 | ||
802 | int btrfs_add_delayed_extent_op(struct btrfs_trans_handle *trans, | |
803 | u64 bytenr, u64 num_bytes, | |
804 | struct btrfs_delayed_extent_op *extent_op) | |
805 | { | |
806 | struct btrfs_delayed_ref_head *head_ref; | |
807 | struct btrfs_delayed_ref_root *delayed_refs; | |
808 | int ret; | |
809 | ||
810 | head_ref = kmalloc(sizeof(*head_ref), GFP_NOFS); | |
811 | if (!head_ref) | |
812 | return -ENOMEM; | |
813 | ||
814 | head_ref->extent_op = extent_op; | |
815 | ||
816 | delayed_refs = &trans->transaction->delayed_refs; | |
817 | spin_lock(&delayed_refs->lock); | |
818 | ||
819 | ret = add_delayed_ref_head(trans, &head_ref->node, bytenr, | |
820 | num_bytes, BTRFS_UPDATE_DELAYED_HEAD, | |
821 | extent_op->is_data); | |
56bec294 | 822 | BUG_ON(ret); |
5d4f98a2 | 823 | |
56bec294 CM |
824 | spin_unlock(&delayed_refs->lock); |
825 | return 0; | |
826 | } | |
827 | ||
1887be66 CM |
828 | /* |
829 | * this does a simple search for the head node for a given extent. | |
830 | * It must be called with the delayed ref spinlock held, and it returns | |
831 | * the head node if any where found, or NULL if not. | |
832 | */ | |
833 | struct btrfs_delayed_ref_head * | |
834 | btrfs_find_delayed_ref_head(struct btrfs_trans_handle *trans, u64 bytenr) | |
835 | { | |
836 | struct btrfs_delayed_ref_node *ref; | |
837 | struct btrfs_delayed_ref_root *delayed_refs; | |
838 | ||
839 | delayed_refs = &trans->transaction->delayed_refs; | |
5d4f98a2 | 840 | ref = find_ref_head(&delayed_refs->root, bytenr, NULL); |
1887be66 CM |
841 | if (ref) |
842 | return btrfs_delayed_node_to_head(ref); | |
843 | return NULL; | |
844 | } | |
845 | ||
56bec294 CM |
846 | /* |
847 | * add a delayed ref to the tree. This does all of the accounting required | |
848 | * to make sure the delayed ref is eventually processed before this | |
849 | * transaction commits. | |
850 | * | |
851 | * The main point of this call is to add and remove a backreference in a single | |
852 | * shot, taking the lock only once, and only searching for the head node once. | |
853 | * | |
854 | * It is the same as doing a ref add and delete in two separate calls. | |
855 | */ | |
5d4f98a2 | 856 | #if 0 |
56bec294 CM |
857 | int btrfs_update_delayed_ref(struct btrfs_trans_handle *trans, |
858 | u64 bytenr, u64 num_bytes, u64 orig_parent, | |
859 | u64 parent, u64 orig_ref_root, u64 ref_root, | |
860 | u64 orig_ref_generation, u64 ref_generation, | |
861 | u64 owner_objectid, int pin) | |
862 | { | |
863 | struct btrfs_delayed_ref *ref; | |
864 | struct btrfs_delayed_ref *old_ref; | |
865 | struct btrfs_delayed_ref_head *head_ref; | |
866 | struct btrfs_delayed_ref_root *delayed_refs; | |
867 | int ret; | |
868 | ||
869 | ref = kmalloc(sizeof(*ref), GFP_NOFS); | |
870 | if (!ref) | |
871 | return -ENOMEM; | |
872 | ||
873 | old_ref = kmalloc(sizeof(*old_ref), GFP_NOFS); | |
874 | if (!old_ref) { | |
875 | kfree(ref); | |
876 | return -ENOMEM; | |
877 | } | |
878 | ||
879 | /* | |
880 | * the parent = 0 case comes from cases where we don't actually | |
881 | * know the parent yet. It will get updated later via a add/drop | |
882 | * pair. | |
883 | */ | |
884 | if (parent == 0) | |
885 | parent = bytenr; | |
886 | if (orig_parent == 0) | |
887 | orig_parent = bytenr; | |
888 | ||
889 | head_ref = kmalloc(sizeof(*head_ref), GFP_NOFS); | |
890 | if (!head_ref) { | |
891 | kfree(ref); | |
892 | kfree(old_ref); | |
893 | return -ENOMEM; | |
894 | } | |
895 | delayed_refs = &trans->transaction->delayed_refs; | |
896 | spin_lock(&delayed_refs->lock); | |
897 | ||
898 | /* | |
899 | * insert both the head node and the new ref without dropping | |
900 | * the spin lock | |
901 | */ | |
902 | ret = __btrfs_add_delayed_ref(trans, &head_ref->node, bytenr, num_bytes, | |
903 | (u64)-1, 0, 0, 0, | |
1a81af4d | 904 | BTRFS_UPDATE_DELAYED_HEAD, 0); |
56bec294 CM |
905 | BUG_ON(ret); |
906 | ||
907 | ret = __btrfs_add_delayed_ref(trans, &ref->node, bytenr, num_bytes, | |
908 | parent, ref_root, ref_generation, | |
909 | owner_objectid, BTRFS_ADD_DELAYED_REF, 0); | |
910 | BUG_ON(ret); | |
911 | ||
912 | ret = __btrfs_add_delayed_ref(trans, &old_ref->node, bytenr, num_bytes, | |
913 | orig_parent, orig_ref_root, | |
914 | orig_ref_generation, owner_objectid, | |
915 | BTRFS_DROP_DELAYED_REF, pin); | |
916 | BUG_ON(ret); | |
917 | spin_unlock(&delayed_refs->lock); | |
918 | return 0; | |
919 | } | |
5d4f98a2 | 920 | #endif |