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Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes...
[linux-2.6-block.git] / fs / btrfs / ctree.c
CommitLineData
6cbd5570 1/*
d352ac68 2 * Copyright (C) 2007,2008 Oracle. All rights reserved.
6cbd5570
CM		 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
a6b6e75e 19#include <linux/sched.h>
eb60ceac
CM		 20#include "ctree.h"
21#include "disk-io.h"
7f5c1516 22#include "transaction.h"
5f39d397 23#include "print-tree.h"
925baedd 24#include "locking.h"
9a8dd150 25
e089f05c
CM		 26static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root
27 *root, struct btrfs_path *path, int level);
28static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
d4dbff95 29 *root, struct btrfs_key *ins_key,
cc0c5538 30 struct btrfs_path *path, int data_size, int extend);
5f39d397
CM		 31static int push_node_left(struct btrfs_trans_handle *trans,
32 struct btrfs_root *root, struct extent_buffer *dst,
971a1f66 33 struct extent_buffer *src, int empty);
5f39d397
CM		 34static int balance_node_right(struct btrfs_trans_handle *trans,
35 struct btrfs_root *root,
36 struct extent_buffer *dst_buf,
37 struct extent_buffer *src_buf);
e089f05c
CM		 38static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
39 struct btrfs_path *path, int level, int slot);
d97e63b6 40
df24a2b9 41struct btrfs_path *btrfs_alloc_path(void)
2c90e5d6 42{
df24a2b9 43 struct btrfs_path *path;
e00f7308
JM		 44 path = kmem_cache_zalloc(btrfs_path_cachep, GFP_NOFS);
45 if (path)
2cc58cf2 46 path->reada = 1;
df24a2b9 47 return path;
2c90e5d6
CM		 48}
49
b4ce94de
CM		 50/*
51 * set all locked nodes in the path to blocking locks. This should
52 * be done before scheduling
53 */
54noinline void btrfs_set_path_blocking(struct btrfs_path *p)
55{
56 int i;
57 for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
58 if (p->nodes[i] && p->locks[i])
59 btrfs_set_lock_blocking(p->nodes[i]);
60 }
61}
62
63/*
64 * reset all the locked nodes in the patch to spinning locks.
4008c04a
CM		 65 *
66 * held is used to keep lockdep happy, when lockdep is enabled
67 * we set held to a blocking lock before we go around and
68 * retake all the spinlocks in the path. You can safely use NULL
69 * for held
b4ce94de 70 */
4008c04a
CM		 71noinline void btrfs_clear_path_blocking(struct btrfs_path *p,
72 struct extent_buffer *held)
b4ce94de
CM		 73{
74 int i;
4008c04a
CM		 75
76#ifdef CONFIG_DEBUG_LOCK_ALLOC
77 /* lockdep really cares that we take all of these spinlocks
78 * in the right order. If any of the locks in the path are not
79 * currently blocking, it is going to complain. So, make really
80 * really sure by forcing the path to blocking before we clear
81 * the path blocking.
82 */
83 if (held)
84 btrfs_set_lock_blocking(held);
85 btrfs_set_path_blocking(p);
86#endif
87
88 for (i = BTRFS_MAX_LEVEL - 1; i >= 0; i--) {
b4ce94de
CM		 89 if (p->nodes[i] && p->locks[i])
90 btrfs_clear_lock_blocking(p->nodes[i]);
91 }
4008c04a
CM		 92
93#ifdef CONFIG_DEBUG_LOCK_ALLOC
94 if (held)
95 btrfs_clear_lock_blocking(held);
96#endif
b4ce94de
CM		 97}
98
d352ac68 99/* this also releases the path */
df24a2b9 100void btrfs_free_path(struct btrfs_path *p)
be0e5c09 101{
df24a2b9
CM		 102 btrfs_release_path(NULL, p);
103 kmem_cache_free(btrfs_path_cachep, p);
be0e5c09
CM		 104}
105
d352ac68
CM		 106/*
107 * path release drops references on the extent buffers in the path
108 * and it drops any locks held by this path
109 *
110 * It is safe to call this on paths that no locks or extent buffers held.
111 */
d397712b 112noinline void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p)
eb60ceac
CM		 113{
114 int i;
a2135011 115
234b63a0 116 for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
3f157a2f 117 p->slots[i] = 0;
eb60ceac 118 if (!p->nodes[i])
925baedd
CM		 119 continue;
120 if (p->locks[i]) {
121 btrfs_tree_unlock(p->nodes[i]);
122 p->locks[i] = 0;
123 }
5f39d397 124 free_extent_buffer(p->nodes[i]);
3f157a2f 125 p->nodes[i] = NULL;
eb60ceac
CM		 126 }
127}
128
d352ac68
CM		 129/*
130 * safely gets a reference on the root node of a tree. A lock
131 * is not taken, so a concurrent writer may put a different node
132 * at the root of the tree. See btrfs_lock_root_node for the
133 * looping required.
134 *
135 * The extent buffer returned by this has a reference taken, so
136 * it won't disappear. It may stop being the root of the tree
137 * at any time because there are no locks held.
138 */
925baedd
CM		 139struct extent_buffer *btrfs_root_node(struct btrfs_root *root)
140{
141 struct extent_buffer *eb;
142 spin_lock(&root->node_lock);
143 eb = root->node;
144 extent_buffer_get(eb);
145 spin_unlock(&root->node_lock);
146 return eb;
147}
148
d352ac68
CM		 149/* loop around taking references on and locking the root node of the
150 * tree until you end up with a lock on the root. A locked buffer
151 * is returned, with a reference held.
152 */
925baedd
CM		 153struct extent_buffer *btrfs_lock_root_node(struct btrfs_root *root)
154{
155 struct extent_buffer *eb;
156
d397712b 157 while (1) {
925baedd
CM		 158 eb = btrfs_root_node(root);
159 btrfs_tree_lock(eb);
160
161 spin_lock(&root->node_lock);
162 if (eb == root->node) {
163 spin_unlock(&root->node_lock);
164 break;
165 }
166 spin_unlock(&root->node_lock);
167
168 btrfs_tree_unlock(eb);
169 free_extent_buffer(eb);
170 }
171 return eb;
172}
173
d352ac68
CM		 174/* cowonly root (everything not a reference counted cow subvolume), just get
175 * put onto a simple dirty list. transaction.c walks this to make sure they
176 * get properly updated on disk.
177 */
0b86a832
CM		 178static void add_root_to_dirty_list(struct btrfs_root *root)
179{
180 if (root->track_dirty && list_empty(&root->dirty_list)) {
181 list_add(&root->dirty_list,
182 &root->fs_info->dirty_cowonly_roots);
183 }
184}
185
d352ac68
CM		 186/*
187 * used by snapshot creation to make a copy of a root for a tree with
188 * a given objectid. The buffer with the new root node is returned in
189 * cow_ret, and this func returns zero on success or a negative error code.
190 */
be20aa9d
CM		 191int btrfs_copy_root(struct btrfs_trans_handle *trans,
192 struct btrfs_root *root,
193 struct extent_buffer *buf,
194 struct extent_buffer **cow_ret, u64 new_root_objectid)
195{
196 struct extent_buffer *cow;
197 u32 nritems;
198 int ret = 0;
199 int level;
5d4f98a2 200 struct btrfs_disk_key disk_key;
be20aa9d
CM		 201
202 WARN_ON(root->ref_cows && trans->transid !=
203 root->fs_info->running_transaction->transid);
204 WARN_ON(root->ref_cows && trans->transid != root->last_trans);
205
206 level = btrfs_header_level(buf);
207 nritems = btrfs_header_nritems(buf);
5d4f98a2
YZ		 208 if (level == 0)
209 btrfs_item_key(buf, &disk_key, 0);
210 else
211 btrfs_node_key(buf, &disk_key, 0);
31840ae1 212
5d4f98a2
YZ		 213 cow = btrfs_alloc_free_block(trans, root, buf->len, 0,
214 new_root_objectid, &disk_key, level,
215 buf->start, 0);
216 if (IS_ERR(cow))
be20aa9d
CM		 217 return PTR_ERR(cow);
218
219 copy_extent_buffer(cow, buf, 0, 0, cow->len);
220 btrfs_set_header_bytenr(cow, cow->start);
221 btrfs_set_header_generation(cow, trans->transid);
5d4f98a2
YZ		 222 btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV);
223 btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN |
224 BTRFS_HEADER_FLAG_RELOC);
225 if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID)
226 btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC);
227 else
228 btrfs_set_header_owner(cow, new_root_objectid);
be20aa9d 229
2b82032c
YZ		 230 write_extent_buffer(cow, root->fs_info->fsid,
231 (unsigned long)btrfs_header_fsid(cow),
232 BTRFS_FSID_SIZE);
233
be20aa9d 234 WARN_ON(btrfs_header_generation(buf) > trans->transid);
5d4f98a2
YZ		 235 if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID)
236 ret = btrfs_inc_ref(trans, root, cow, 1);
237 else
238 ret = btrfs_inc_ref(trans, root, cow, 0);
4aec2b52 239
be20aa9d
CM		 240 if (ret)
241 return ret;
242
243 btrfs_mark_buffer_dirty(cow);
244 *cow_ret = cow;
245 return 0;
246}
247
5d4f98a2
YZ		 248/*
249 * check if the tree block can be shared by multiple trees
250 */
251int btrfs_block_can_be_shared(struct btrfs_root *root,
252 struct extent_buffer *buf)
253{
254 /*
255 * Tree blocks not in refernece counted trees and tree roots
256 * are never shared. If a block was allocated after the last
257 * snapshot and the block was not allocated by tree relocation,
258 * we know the block is not shared.
259 */
260 if (root->ref_cows &&
261 buf != root->node && buf != root->commit_root &&
262 (btrfs_header_generation(buf) <=
263 btrfs_root_last_snapshot(&root->root_item) ||
264 btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC)))
265 return 1;
266#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
267 if (root->ref_cows &&
268 btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV)
269 return 1;
270#endif
271 return 0;
272}
273
274static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans,
275 struct btrfs_root *root,
276 struct extent_buffer *buf,
277 struct extent_buffer *cow)
278{
279 u64 refs;
280 u64 owner;
281 u64 flags;
282 u64 new_flags = 0;
283 int ret;
284
285 /*
286 * Backrefs update rules:
287 *
288 * Always use full backrefs for extent pointers in tree block
289 * allocated by tree relocation.
290 *
291 * If a shared tree block is no longer referenced by its owner
292 * tree (btrfs_header_owner(buf) == root->root_key.objectid),
293 * use full backrefs for extent pointers in tree block.
294 *
295 * If a tree block is been relocating
296 * (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID),
297 * use full backrefs for extent pointers in tree block.
298 * The reason for this is some operations (such as drop tree)
299 * are only allowed for blocks use full backrefs.
300 */
301
302 if (btrfs_block_can_be_shared(root, buf)) {
303 ret = btrfs_lookup_extent_info(trans, root, buf->start,
304 buf->len, &refs, &flags);
305 BUG_ON(ret);
306 BUG_ON(refs == 0);
307 } else {
308 refs = 1;
309 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID ||
310 btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV)
311 flags = BTRFS_BLOCK_FLAG_FULL_BACKREF;
312 else
313 flags = 0;
314 }
315
316 owner = btrfs_header_owner(buf);
317 BUG_ON(owner == BTRFS_TREE_RELOC_OBJECTID &&
318 !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF));
319
320 if (refs > 1) {
321 if ((owner == root->root_key.objectid ||
322 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) &&
323 !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)) {
324 ret = btrfs_inc_ref(trans, root, buf, 1);
325 BUG_ON(ret);
326
327 if (root->root_key.objectid ==
328 BTRFS_TREE_RELOC_OBJECTID) {
329 ret = btrfs_dec_ref(trans, root, buf, 0);
330 BUG_ON(ret);
331 ret = btrfs_inc_ref(trans, root, cow, 1);
332 BUG_ON(ret);
333 }
334 new_flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF;
335 } else {
336
337 if (root->root_key.objectid ==
338 BTRFS_TREE_RELOC_OBJECTID)
339 ret = btrfs_inc_ref(trans, root, cow, 1);
340 else
341 ret = btrfs_inc_ref(trans, root, cow, 0);
342 BUG_ON(ret);
343 }
344 if (new_flags != 0) {
345 ret = btrfs_set_disk_extent_flags(trans, root,
346 buf->start,
347 buf->len,
348 new_flags, 0);
349 BUG_ON(ret);
350 }
351 } else {
352 if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF) {
353 if (root->root_key.objectid ==
354 BTRFS_TREE_RELOC_OBJECTID)
355 ret = btrfs_inc_ref(trans, root, cow, 1);
356 else
357 ret = btrfs_inc_ref(trans, root, cow, 0);
358 BUG_ON(ret);
359 ret = btrfs_dec_ref(trans, root, buf, 1);
360 BUG_ON(ret);
361 }
362 clean_tree_block(trans, root, buf);
363 }
364 return 0;
365}
366
d352ac68 367/*
d397712b
CM		 368 * does the dirty work in cow of a single block. The parent block (if
369 * supplied) is updated to point to the new cow copy. The new buffer is marked
370 * dirty and returned locked. If you modify the block it needs to be marked
371 * dirty again.
d352ac68
CM		 372 *
373 * search_start -- an allocation hint for the new block
374 *
d397712b
CM		 375 * empty_size -- a hint that you plan on doing more cow. This is the size in
376 * bytes the allocator should try to find free next to the block it returns.
377 * This is just a hint and may be ignored by the allocator.
d352ac68 378 */
d397712b 379static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans,
5f39d397
CM		 380 struct btrfs_root *root,
381 struct extent_buffer *buf,
382 struct extent_buffer *parent, int parent_slot,
383 struct extent_buffer **cow_ret,
9fa8cfe7 384 u64 search_start, u64 empty_size)
02217ed2 385{
5d4f98a2 386 struct btrfs_disk_key disk_key;
5f39d397 387 struct extent_buffer *cow;
7bb86316 388 int level;
925baedd 389 int unlock_orig = 0;
5d4f98a2 390 u64 parent_start;
7bb86316 391
925baedd
CM		 392 if (*cow_ret == buf)
393 unlock_orig = 1;
394
b9447ef8 395 btrfs_assert_tree_locked(buf);
925baedd 396
7bb86316
CM		 397 WARN_ON(root->ref_cows && trans->transid !=
398 root->fs_info->running_transaction->transid);
6702ed49 399 WARN_ON(root->ref_cows && trans->transid != root->last_trans);
5f39d397 400
7bb86316 401 level = btrfs_header_level(buf);
31840ae1 402
5d4f98a2
YZ		 403 if (level == 0)
404 btrfs_item_key(buf, &disk_key, 0);
405 else
406 btrfs_node_key(buf, &disk_key, 0);
407
408 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) {
409 if (parent)
410 parent_start = parent->start;
411 else
412 parent_start = 0;
413 } else
414 parent_start = 0;
415
416 cow = btrfs_alloc_free_block(trans, root, buf->len, parent_start,
417 root->root_key.objectid, &disk_key,
418 level, search_start, empty_size);
54aa1f4d
CM		 419 if (IS_ERR(cow))
420 return PTR_ERR(cow);
6702ed49 421
b4ce94de
CM		 422 /* cow is set to blocking by btrfs_init_new_buffer */
423
5f39d397 424 copy_extent_buffer(cow, buf, 0, 0, cow->len);
db94535d 425 btrfs_set_header_bytenr(cow, cow->start);
5f39d397 426 btrfs_set_header_generation(cow, trans->transid);
5d4f98a2
YZ		 427 btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV);
428 btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN |
429 BTRFS_HEADER_FLAG_RELOC);
430 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)
431 btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC);
432 else
433 btrfs_set_header_owner(cow, root->root_key.objectid);
6702ed49 434
2b82032c
YZ		 435 write_extent_buffer(cow, root->fs_info->fsid,
436 (unsigned long)btrfs_header_fsid(cow),
437 BTRFS_FSID_SIZE);
438
5d4f98a2 439 update_ref_for_cow(trans, root, buf, cow);
1a40e23b 440
02217ed2 441 if (buf == root->node) {
925baedd 442 WARN_ON(parent && parent != buf);
5d4f98a2
YZ		 443 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID ||
444 btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV)
445 parent_start = buf->start;
446 else
447 parent_start = 0;
925baedd
CM		 448
449 spin_lock(&root->node_lock);
02217ed2 450 root->node = cow;
5f39d397 451 extent_buffer_get(cow);
925baedd
CM		 452 spin_unlock(&root->node_lock);
453
5d4f98a2
YZ		 454 btrfs_free_extent(trans, root, buf->start, buf->len,
455 parent_start, root->root_key.objectid,
456 level, 0);
5f39d397 457 free_extent_buffer(buf);
0b86a832 458 add_root_to_dirty_list(root);
02217ed2 459 } else {
5d4f98a2
YZ		 460 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)
461 parent_start = parent->start;
462 else
463 parent_start = 0;
464
465 WARN_ON(trans->transid != btrfs_header_generation(parent));
5f39d397 466 btrfs_set_node_blockptr(parent, parent_slot,
db94535d 467 cow->start);
74493f7a
CM		 468 btrfs_set_node_ptr_generation(parent, parent_slot,
469 trans->transid);
d6025579 470 btrfs_mark_buffer_dirty(parent);
7bb86316 471 btrfs_free_extent(trans, root, buf->start, buf->len,
5d4f98a2
YZ		 472 parent_start, root->root_key.objectid,
473 level, 0);
02217ed2 474 }
925baedd
CM		 475 if (unlock_orig)
476 btrfs_tree_unlock(buf);
5f39d397 477 free_extent_buffer(buf);
ccd467d6 478 btrfs_mark_buffer_dirty(cow);
2c90e5d6 479 *cow_ret = cow;
02217ed2
CM		 480 return 0;
481}
482
5d4f98a2
YZ		 483static inline int should_cow_block(struct btrfs_trans_handle *trans,
484 struct btrfs_root *root,
485 struct extent_buffer *buf)
486{
487 if (btrfs_header_generation(buf) == trans->transid &&
488 !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN) &&
489 !(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID &&
490 btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC)))
491 return 0;
492 return 1;
493}
494
d352ac68
CM		 495/*
496 * cows a single block, see __btrfs_cow_block for the real work.
497 * This version of it has extra checks so that a block isn't cow'd more than
498 * once per transaction, as long as it hasn't been written yet
499 */
d397712b 500noinline int btrfs_cow_block(struct btrfs_trans_handle *trans,
5f39d397
CM		 501 struct btrfs_root *root, struct extent_buffer *buf,
502 struct extent_buffer *parent, int parent_slot,
9fa8cfe7 503 struct extent_buffer **cow_ret)
6702ed49
CM		 504{
505 u64 search_start;
f510cfec 506 int ret;
dc17ff8f 507
6702ed49 508 if (trans->transaction != root->fs_info->running_transaction) {
d397712b
CM		 509 printk(KERN_CRIT "trans %llu running %llu\n",
510 (unsigned long long)trans->transid,
511 (unsigned long long)
6702ed49
CM		 512 root->fs_info->running_transaction->transid);
513 WARN_ON(1);
514 }
515 if (trans->transid != root->fs_info->generation) {
d397712b
CM		 516 printk(KERN_CRIT "trans %llu running %llu\n",
517 (unsigned long long)trans->transid,
518 (unsigned long long)root->fs_info->generation);
6702ed49
CM		 519 WARN_ON(1);
520 }
dc17ff8f 521
5d4f98a2 522 if (!should_cow_block(trans, root, buf)) {
6702ed49
CM		 523 *cow_ret = buf;
524 return 0;
525 }
c487685d 526
0b86a832 527 search_start = buf->start & ~((u64)(1024 * 1024 * 1024) - 1);
b4ce94de
CM		 528
529 if (parent)
530 btrfs_set_lock_blocking(parent);
531 btrfs_set_lock_blocking(buf);
532
f510cfec 533 ret = __btrfs_cow_block(trans, root, buf, parent,
9fa8cfe7 534 parent_slot, cow_ret, search_start, 0);
f510cfec 535 return ret;
6702ed49
CM		 536}
537
d352ac68
CM		 538/*
539 * helper function for defrag to decide if two blocks pointed to by a
540 * node are actually close by
541 */
6b80053d 542static int close_blocks(u64 blocknr, u64 other, u32 blocksize)
6702ed49 543{
6b80053d 544 if (blocknr < other && other - (blocknr + blocksize) < 32768)
6702ed49 545 return 1;
6b80053d 546 if (blocknr > other && blocknr - (other + blocksize) < 32768)
6702ed49
CM		 547 return 1;
548 return 0;
549}
550
081e9573
CM		 551/*
552 * compare two keys in a memcmp fashion
553 */
554static int comp_keys(struct btrfs_disk_key *disk, struct btrfs_key *k2)
555{
556 struct btrfs_key k1;
557
558 btrfs_disk_key_to_cpu(&k1, disk);
559
20736aba 560 return btrfs_comp_cpu_keys(&k1, k2);
081e9573
CM		 561}
562
f3465ca4
JB		 563/*
564 * same as comp_keys only with two btrfs_key's
565 */
5d4f98a2 566int btrfs_comp_cpu_keys(struct btrfs_key *k1, struct btrfs_key *k2)
f3465ca4
JB		 567{
568 if (k1->objectid > k2->objectid)
569 return 1;
570 if (k1->objectid < k2->objectid)
571 return -1;
572 if (k1->type > k2->type)
573 return 1;
574 if (k1->type < k2->type)
575 return -1;
576 if (k1->offset > k2->offset)
577 return 1;
578 if (k1->offset < k2->offset)
579 return -1;
580 return 0;
581}
081e9573 582
d352ac68
CM		 583/*
584 * this is used by the defrag code to go through all the
585 * leaves pointed to by a node and reallocate them so that
586 * disk order is close to key order
587 */
6702ed49 588int btrfs_realloc_node(struct btrfs_trans_handle *trans,
5f39d397 589 struct btrfs_root *root, struct extent_buffer *parent,
a6b6e75e
CM		 590 int start_slot, int cache_only, u64 *last_ret,
591 struct btrfs_key *progress)
6702ed49 592{
6b80053d 593 struct extent_buffer *cur;
6702ed49 594 u64 blocknr;
ca7a79ad 595 u64 gen;
e9d0b13b
CM		 596 u64 search_start = *last_ret;
597 u64 last_block = 0;
6702ed49
CM		 598 u64 other;
599 u32 parent_nritems;
6702ed49
CM		 600 int end_slot;
601 int i;
602 int err = 0;
f2183bde 603 int parent_level;
6b80053d
CM		 604 int uptodate;
605 u32 blocksize;
081e9573
CM		 606 int progress_passed = 0;
607 struct btrfs_disk_key disk_key;
6702ed49 608
5708b959
CM		 609 parent_level = btrfs_header_level(parent);
610 if (cache_only && parent_level != 1)
611 return 0;
612
d397712b 613 if (trans->transaction != root->fs_info->running_transaction)
6702ed49 614 WARN_ON(1);
d397712b 615 if (trans->transid != root->fs_info->generation)
6702ed49 616 WARN_ON(1);
86479a04 617
6b80053d 618 parent_nritems = btrfs_header_nritems(parent);
6b80053d 619 blocksize = btrfs_level_size(root, parent_level - 1);
6702ed49
CM		 620 end_slot = parent_nritems;
621
622 if (parent_nritems == 1)
623 return 0;
624
b4ce94de
CM		 625 btrfs_set_lock_blocking(parent);
626
6702ed49
CM		 627 for (i = start_slot; i < end_slot; i++) {
628 int close = 1;
a6b6e75e 629
5708b959
CM		 630 if (!parent->map_token) {
631 map_extent_buffer(parent,
632 btrfs_node_key_ptr_offset(i),
633 sizeof(struct btrfs_key_ptr),
634 &parent->map_token, &parent->kaddr,
635 &parent->map_start, &parent->map_len,
636 KM_USER1);
637 }
081e9573
CM		 638 btrfs_node_key(parent, &disk_key, i);
639 if (!progress_passed && comp_keys(&disk_key, progress) < 0)
640 continue;
641
642 progress_passed = 1;
6b80053d 643 blocknr = btrfs_node_blockptr(parent, i);
ca7a79ad 644 gen = btrfs_node_ptr_generation(parent, i);
e9d0b13b
CM		 645 if (last_block == 0)
646 last_block = blocknr;
5708b959 647
6702ed49 648 if (i > 0) {
6b80053d
CM		 649 other = btrfs_node_blockptr(parent, i - 1);
650 close = close_blocks(blocknr, other, blocksize);
6702ed49 651 }
0ef3e66b 652 if (!close && i < end_slot - 2) {
6b80053d
CM		 653 other = btrfs_node_blockptr(parent, i + 1);
654 close = close_blocks(blocknr, other, blocksize);
6702ed49 655 }
e9d0b13b
CM		 656 if (close) {
657 last_block = blocknr;
6702ed49 658 continue;
e9d0b13b 659 }
5708b959
CM		 660 if (parent->map_token) {
661 unmap_extent_buffer(parent, parent->map_token,
662 KM_USER1);
663 parent->map_token = NULL;
664 }
6702ed49 665
6b80053d
CM		 666 cur = btrfs_find_tree_block(root, blocknr, blocksize);
667 if (cur)
1259ab75 668 uptodate = btrfs_buffer_uptodate(cur, gen);
6b80053d
CM		 669 else
670 uptodate = 0;
5708b959 671 if (!cur || !uptodate) {
6702ed49 672 if (cache_only) {
6b80053d 673 free_extent_buffer(cur);
6702ed49
CM		 674 continue;
675 }
6b80053d
CM		 676 if (!cur) {
677 cur = read_tree_block(root, blocknr,
ca7a79ad 678 blocksize, gen);
6b80053d 679 } else if (!uptodate) {
ca7a79ad 680 btrfs_read_buffer(cur, gen);
f2183bde 681 }
6702ed49 682 }
e9d0b13b 683 if (search_start == 0)
6b80053d 684 search_start = last_block;
e9d0b13b 685
e7a84565 686 btrfs_tree_lock(cur);
b4ce94de 687 btrfs_set_lock_blocking(cur);
6b80053d 688 err = __btrfs_cow_block(trans, root, cur, parent, i,
e7a84565 689 &cur, search_start,
6b80053d 690 min(16 * blocksize,
9fa8cfe7 691 (end_slot - i) * blocksize));
252c38f0 692 if (err) {
e7a84565 693 btrfs_tree_unlock(cur);
6b80053d 694 free_extent_buffer(cur);
6702ed49 695 break;
252c38f0 696 }
e7a84565
CM		 697 search_start = cur->start;
698 last_block = cur->start;
f2183bde 699 *last_ret = search_start;
e7a84565
CM		 700 btrfs_tree_unlock(cur);
701 free_extent_buffer(cur);
6702ed49 702 }
5708b959
CM		 703 if (parent->map_token) {
704 unmap_extent_buffer(parent, parent->map_token,
705 KM_USER1);
706 parent->map_token = NULL;
707 }
6702ed49
CM		 708 return err;
709}
710
74123bd7
CM		 711/*
712 * The leaf data grows from end-to-front in the node.
713 * this returns the address of the start of the last item,
714 * which is the stop of the leaf data stack
715 */
123abc88 716static inline unsigned int leaf_data_end(struct btrfs_root *root,
5f39d397 717 struct extent_buffer *leaf)
be0e5c09 718{
5f39d397 719 u32 nr = btrfs_header_nritems(leaf);
be0e5c09 720 if (nr == 0)
123abc88 721 return BTRFS_LEAF_DATA_SIZE(root);
5f39d397 722 return btrfs_item_offset_nr(leaf, nr - 1);
be0e5c09
CM		 723}
724
d352ac68
CM		 725/*
726 * extra debugging checks to make sure all the items in a key are
727 * well formed and in the proper order
728 */
123abc88
CM		 729static int check_node(struct btrfs_root *root, struct btrfs_path *path,
730 int level)
aa5d6bed 731{
5f39d397
CM		 732 struct extent_buffer *parent = NULL;
733 struct extent_buffer *node = path->nodes[level];
734 struct btrfs_disk_key parent_key;
735 struct btrfs_disk_key node_key;
aa5d6bed 736 int parent_slot;
8d7be552
CM		 737 int slot;
738 struct btrfs_key cpukey;
5f39d397 739 u32 nritems = btrfs_header_nritems(node);
aa5d6bed
CM		 740
741 if (path->nodes[level + 1])
5f39d397 742 parent = path->nodes[level + 1];
a1f39630 743
8d7be552 744 slot = path->slots[level];
7518a238
CM		 745 BUG_ON(nritems == 0);
746 if (parent) {
a1f39630 747 parent_slot = path->slots[level + 1];
5f39d397
CM		 748 btrfs_node_key(parent, &parent_key, parent_slot);
749 btrfs_node_key(node, &node_key, 0);
750 BUG_ON(memcmp(&parent_key, &node_key,
e2fa7227 751 sizeof(struct btrfs_disk_key)));
1d4f8a0c 752 BUG_ON(btrfs_node_blockptr(parent, parent_slot) !=
db94535d 753 btrfs_header_bytenr(node));
aa5d6bed 754 }
123abc88 755 BUG_ON(nritems > BTRFS_NODEPTRS_PER_BLOCK(root));
8d7be552 756 if (slot != 0) {
5f39d397
CM		 757 btrfs_node_key_to_cpu(node, &cpukey, slot - 1);
758 btrfs_node_key(node, &node_key, slot);
759 BUG_ON(comp_keys(&node_key, &cpukey) <= 0);
8d7be552
CM		 760 }
761 if (slot < nritems - 1) {
5f39d397
CM		 762 btrfs_node_key_to_cpu(node, &cpukey, slot + 1);
763 btrfs_node_key(node, &node_key, slot);
764 BUG_ON(comp_keys(&node_key, &cpukey) >= 0);
aa5d6bed
CM		 765 }
766 return 0;
767}
768
d352ac68
CM		 769/*
770 * extra checking to make sure all the items in a leaf are
771 * well formed and in the proper order
772 */
123abc88
CM		 773static int check_leaf(struct btrfs_root *root, struct btrfs_path *path,
774 int level)
aa5d6bed 775{
5f39d397
CM		 776 struct extent_buffer *leaf = path->nodes[level];
777 struct extent_buffer *parent = NULL;
aa5d6bed 778 int parent_slot;
8d7be552 779 struct btrfs_key cpukey;
5f39d397
CM		 780 struct btrfs_disk_key parent_key;
781 struct btrfs_disk_key leaf_key;
782 int slot = path->slots[0];
8d7be552 783
5f39d397 784 u32 nritems = btrfs_header_nritems(leaf);
aa5d6bed
CM		 785
786 if (path->nodes[level + 1])
5f39d397 787 parent = path->nodes[level + 1];
7518a238
CM		 788
789 if (nritems == 0)
790 return 0;
791
792 if (parent) {
a1f39630 793 parent_slot = path->slots[level + 1];
5f39d397
CM		 794 btrfs_node_key(parent, &parent_key, parent_slot);
795 btrfs_item_key(leaf, &leaf_key, 0);
6702ed49 796
5f39d397 797 BUG_ON(memcmp(&parent_key, &leaf_key,
e2fa7227 798 sizeof(struct btrfs_disk_key)));
1d4f8a0c 799 BUG_ON(btrfs_node_blockptr(parent, parent_slot) !=
db94535d 800 btrfs_header_bytenr(leaf));
5f39d397 801 }
5f39d397
CM		 802 if (slot != 0 && slot < nritems - 1) {
803 btrfs_item_key(leaf, &leaf_key, slot);
804 btrfs_item_key_to_cpu(leaf, &cpukey, slot - 1);
805 if (comp_keys(&leaf_key, &cpukey) <= 0) {
806 btrfs_print_leaf(root, leaf);
d397712b 807 printk(KERN_CRIT "slot %d offset bad key\n", slot);
5f39d397
CM		 808 BUG_ON(1);
809 }
810 if (btrfs_item_offset_nr(leaf, slot - 1) !=
811 btrfs_item_end_nr(leaf, slot)) {
812 btrfs_print_leaf(root, leaf);
d397712b 813 printk(KERN_CRIT "slot %d offset bad\n", slot);
5f39d397
CM		 814 BUG_ON(1);
815 }
8d7be552
CM		 816 }
817 if (slot < nritems - 1) {
5f39d397
CM		 818 btrfs_item_key(leaf, &leaf_key, slot);
819 btrfs_item_key_to_cpu(leaf, &cpukey, slot + 1);
820 BUG_ON(comp_keys(&leaf_key, &cpukey) >= 0);
821 if (btrfs_item_offset_nr(leaf, slot) !=
822 btrfs_item_end_nr(leaf, slot + 1)) {
823 btrfs_print_leaf(root, leaf);
d397712b 824 printk(KERN_CRIT "slot %d offset bad\n", slot);
5f39d397
CM		 825 BUG_ON(1);
826 }
aa5d6bed 827 }
5f39d397
CM		 828 BUG_ON(btrfs_item_offset_nr(leaf, 0) +
829 btrfs_item_size_nr(leaf, 0) != BTRFS_LEAF_DATA_SIZE(root));
aa5d6bed
CM		 830 return 0;
831}
832
d397712b 833static noinline int check_block(struct btrfs_root *root,
98ed5174 834 struct btrfs_path *path, int level)
aa5d6bed 835{
85d824c4 836 return 0;
aa5d6bed 837 if (level == 0)
123abc88
CM		 838 return check_leaf(root, path, level);
839 return check_node(root, path, level);
aa5d6bed
CM		 840}
841
74123bd7 842/*
5f39d397
CM		 843 * search for key in the extent_buffer. The items start at offset p,
844 * and they are item_size apart. There are 'max' items in p.
845 *
74123bd7
CM		 846 * the slot in the array is returned via slot, and it points to
847 * the place where you would insert key if it is not found in
848 * the array.
849 *
850 * slot may point to max if the key is bigger than all of the keys
851 */
e02119d5
CM		 852static noinline int generic_bin_search(struct extent_buffer *eb,
853 unsigned long p,
854 int item_size, struct btrfs_key *key,
855 int max, int *slot)
be0e5c09
CM		 856{
857 int low = 0;
858 int high = max;
859 int mid;
860 int ret;
479965d6 861 struct btrfs_disk_key *tmp = NULL;
5f39d397
CM		 862 struct btrfs_disk_key unaligned;
863 unsigned long offset;
864 char *map_token = NULL;
865 char *kaddr = NULL;
866 unsigned long map_start = 0;
867 unsigned long map_len = 0;
479965d6 868 int err;
be0e5c09 869
d397712b 870 while (low < high) {
be0e5c09 871 mid = (low + high) / 2;
5f39d397
CM		 872 offset = p + mid * item_size;
873
874 if (!map_token || offset < map_start ||
875 (offset + sizeof(struct btrfs_disk_key)) >
876 map_start + map_len) {
479965d6 877 if (map_token) {
5f39d397 878 unmap_extent_buffer(eb, map_token, KM_USER0);
479965d6
CM		 879 map_token = NULL;
880 }
934d375b
CM		 881
882 err = map_private_extent_buffer(eb, offset,
479965d6
CM		 883 sizeof(struct btrfs_disk_key),
884 &map_token, &kaddr,
885 &map_start, &map_len, KM_USER0);
886
887 if (!err) {
888 tmp = (struct btrfs_disk_key *)(kaddr + offset -
889 map_start);
890 } else {
891 read_extent_buffer(eb, &unaligned,
892 offset, sizeof(unaligned));
893 tmp = &unaligned;
894 }
5f39d397 895
5f39d397
CM		 896 } else {
897 tmp = (struct btrfs_disk_key *)(kaddr + offset -
898 map_start);
899 }
be0e5c09
CM		 900 ret = comp_keys(tmp, key);
901
902 if (ret < 0)
903 low = mid + 1;
904 else if (ret > 0)
905 high = mid;
906 else {
907 *slot = mid;
479965d6
CM		 908 if (map_token)
909 unmap_extent_buffer(eb, map_token, KM_USER0);
be0e5c09
CM		 910 return 0;
911 }
912 }
913 *slot = low;
5f39d397
CM		 914 if (map_token)
915 unmap_extent_buffer(eb, map_token, KM_USER0);
be0e5c09
CM		 916 return 1;
917}
918
97571fd0
CM		 919/*
920 * simple bin_search frontend that does the right thing for
921 * leaves vs nodes
922 */
5f39d397
CM		 923static int bin_search(struct extent_buffer *eb, struct btrfs_key *key,
924 int level, int *slot)
be0e5c09 925{
5f39d397
CM		 926 if (level == 0) {
927 return generic_bin_search(eb,
928 offsetof(struct btrfs_leaf, items),
0783fcfc 929 sizeof(struct btrfs_item),
5f39d397 930 key, btrfs_header_nritems(eb),
7518a238 931 slot);
be0e5c09 932 } else {
5f39d397
CM		 933 return generic_bin_search(eb,
934 offsetof(struct btrfs_node, ptrs),
123abc88 935 sizeof(struct btrfs_key_ptr),
5f39d397 936 key, btrfs_header_nritems(eb),
7518a238 937 slot);
be0e5c09
CM		 938 }
939 return -1;
940}
941
5d4f98a2
YZ		 942int btrfs_bin_search(struct extent_buffer *eb, struct btrfs_key *key,
943 int level, int *slot)
944{
945 return bin_search(eb, key, level, slot);
946}
947
d352ac68
CM		 948/* given a node and slot number, this reads the blocks it points to. The
949 * extent buffer is returned with a reference taken (but unlocked).
950 * NULL is returned on error.
951 */
e02119d5 952static noinline struct extent_buffer *read_node_slot(struct btrfs_root *root,
5f39d397 953 struct extent_buffer *parent, int slot)
bb803951 954{
ca7a79ad 955 int level = btrfs_header_level(parent);
bb803951
CM		 956 if (slot < 0)
957 return NULL;
5f39d397 958 if (slot >= btrfs_header_nritems(parent))
bb803951 959 return NULL;
ca7a79ad
CM		 960
961 BUG_ON(level == 0);
962
db94535d 963 return read_tree_block(root, btrfs_node_blockptr(parent, slot),
ca7a79ad
CM		 964 btrfs_level_size(root, level - 1),
965 btrfs_node_ptr_generation(parent, slot));
bb803951
CM		 966}
967
d352ac68
CM		 968/*
969 * node level balancing, used to make sure nodes are in proper order for
970 * item deletion. We balance from the top down, so we have to make sure
971 * that a deletion won't leave an node completely empty later on.
972 */
e02119d5 973static noinline int balance_level(struct btrfs_trans_handle *trans,
98ed5174
CM		 974 struct btrfs_root *root,
975 struct btrfs_path *path, int level)
bb803951 976{
5f39d397
CM		 977 struct extent_buffer *right = NULL;
978 struct extent_buffer *mid;
979 struct extent_buffer *left = NULL;
980 struct extent_buffer *parent = NULL;
bb803951
CM		 981 int ret = 0;
982 int wret;
983 int pslot;
bb803951 984 int orig_slot = path->slots[level];
54aa1f4d 985 int err_on_enospc = 0;
79f95c82 986 u64 orig_ptr;
bb803951
CM		 987
988 if (level == 0)
989 return 0;
990
5f39d397 991 mid = path->nodes[level];
b4ce94de 992
925baedd 993 WARN_ON(!path->locks[level]);
7bb86316
CM		 994 WARN_ON(btrfs_header_generation(mid) != trans->transid);
995
1d4f8a0c 996 orig_ptr = btrfs_node_blockptr(mid, orig_slot);
79f95c82 997
234b63a0 998 if (level < BTRFS_MAX_LEVEL - 1)
5f39d397 999 parent = path->nodes[level + 1];
bb803951
CM		 1000 pslot = path->slots[level + 1];
1001
40689478
CM		 1002 /*
1003 * deal with the case where there is only one pointer in the root
1004 * by promoting the node below to a root
1005 */
5f39d397
CM		 1006 if (!parent) {
1007 struct extent_buffer *child;
bb803951 1008
5f39d397 1009 if (btrfs_header_nritems(mid) != 1)
bb803951
CM		 1010 return 0;
1011
1012 /* promote the child to a root */
5f39d397 1013 child = read_node_slot(root, mid, 0);
7951f3ce 1014 BUG_ON(!child);
925baedd 1015 btrfs_tree_lock(child);
b4ce94de 1016 btrfs_set_lock_blocking(child);
9fa8cfe7 1017 ret = btrfs_cow_block(trans, root, child, mid, 0, &child);
2f375ab9
Y		 1018 BUG_ON(ret);
1019
925baedd 1020 spin_lock(&root->node_lock);
bb803951 1021 root->node = child;
925baedd
CM		 1022 spin_unlock(&root->node_lock);
1023
0b86a832 1024 add_root_to_dirty_list(root);
925baedd 1025 btrfs_tree_unlock(child);
b4ce94de 1026
925baedd 1027 path->locks[level] = 0;
bb803951 1028 path->nodes[level] = NULL;
5f39d397 1029 clean_tree_block(trans, root, mid);
925baedd 1030 btrfs_tree_unlock(mid);
bb803951 1031 /* once for the path */
5f39d397 1032 free_extent_buffer(mid);
7bb86316 1033 ret = btrfs_free_extent(trans, root, mid->start, mid->len,
5d4f98a2 1034 0, root->root_key.objectid, level, 1);
bb803951 1035 /* once for the root ptr */
5f39d397 1036 free_extent_buffer(mid);
db94535d 1037 return ret;
bb803951 1038 }
5f39d397 1039 if (btrfs_header_nritems(mid) >
123abc88 1040 BTRFS_NODEPTRS_PER_BLOCK(root) / 4)
bb803951
CM		 1041 return 0;
1042
5f39d397 1043 if (btrfs_header_nritems(mid) < 2)
54aa1f4d
CM		 1044 err_on_enospc = 1;
1045
5f39d397
CM		 1046 left = read_node_slot(root, parent, pslot - 1);
1047 if (left) {
925baedd 1048 btrfs_tree_lock(left);
b4ce94de 1049 btrfs_set_lock_blocking(left);
5f39d397 1050 wret = btrfs_cow_block(trans, root, left,
9fa8cfe7 1051 parent, pslot - 1, &left);
54aa1f4d
CM		 1052 if (wret) {
1053 ret = wret;
1054 goto enospc;
1055 }
2cc58cf2 1056 }
5f39d397
CM		 1057 right = read_node_slot(root, parent, pslot + 1);
1058 if (right) {
925baedd 1059 btrfs_tree_lock(right);
b4ce94de 1060 btrfs_set_lock_blocking(right);
5f39d397 1061 wret = btrfs_cow_block(trans, root, right,
9fa8cfe7 1062 parent, pslot + 1, &right);
2cc58cf2
CM		 1063 if (wret) {
1064 ret = wret;
1065 goto enospc;
1066 }
1067 }
1068
1069 /* first, try to make some room in the middle buffer */
5f39d397
CM		 1070 if (left) {
1071 orig_slot += btrfs_header_nritems(left);
bce4eae9 1072 wret = push_node_left(trans, root, left, mid, 1);
79f95c82
CM		 1073 if (wret < 0)
1074 ret = wret;
5f39d397 1075 if (btrfs_header_nritems(mid) < 2)
54aa1f4d 1076 err_on_enospc = 1;
bb803951 1077 }
79f95c82
CM		 1078
1079 /*
1080 * then try to empty the right most buffer into the middle
1081 */
5f39d397 1082 if (right) {
971a1f66 1083 wret = push_node_left(trans, root, mid, right, 1);
54aa1f4d 1084 if (wret < 0 && wret != -ENOSPC)
79f95c82 1085 ret = wret;
5f39d397 1086 if (btrfs_header_nritems(right) == 0) {
db94535d
CM		 1087 u64 bytenr = right->start;
1088 u32 blocksize = right->len;
1089
5f39d397 1090 clean_tree_block(trans, root, right);
925baedd 1091 btrfs_tree_unlock(right);
5f39d397 1092 free_extent_buffer(right);
bb803951 1093 right = NULL;
e089f05c
CM		 1094 wret = del_ptr(trans, root, path, level + 1, pslot +
1095 1);
bb803951
CM		 1096 if (wret)
1097 ret = wret;
db94535d 1098 wret = btrfs_free_extent(trans, root, bytenr,
5d4f98a2
YZ		 1099 blocksize, 0,
1100 root->root_key.objectid,
1101 level, 0);
bb803951
CM		 1102 if (wret)
1103 ret = wret;
1104 } else {
5f39d397
CM		 1105 struct btrfs_disk_key right_key;
1106 btrfs_node_key(right, &right_key, 0);
1107 btrfs_set_node_key(parent, &right_key, pslot + 1);
1108 btrfs_mark_buffer_dirty(parent);
bb803951
CM		 1109 }
1110 }
5f39d397 1111 if (btrfs_header_nritems(mid) == 1) {
79f95c82
CM		 1112 /*
1113 * we're not allowed to leave a node with one item in the
1114 * tree during a delete. A deletion from lower in the tree
1115 * could try to delete the only pointer in this node.
1116 * So, pull some keys from the left.
1117 * There has to be a left pointer at this point because
1118 * otherwise we would have pulled some pointers from the
1119 * right
1120 */
5f39d397
CM		 1121 BUG_ON(!left);
1122 wret = balance_node_right(trans, root, mid, left);
54aa1f4d 1123 if (wret < 0) {
79f95c82 1124 ret = wret;
54aa1f4d
CM		 1125 goto enospc;
1126 }
bce4eae9
CM		 1127 if (wret == 1) {
1128 wret = push_node_left(trans, root, left, mid, 1);
1129 if (wret < 0)
1130 ret = wret;
1131 }
79f95c82
CM		 1132 BUG_ON(wret == 1);
1133 }
5f39d397 1134 if (btrfs_header_nritems(mid) == 0) {
79f95c82 1135 /* we've managed to empty the middle node, drop it */
db94535d
CM		 1136 u64 bytenr = mid->start;
1137 u32 blocksize = mid->len;
925baedd 1138
5f39d397 1139 clean_tree_block(trans, root, mid);
925baedd 1140 btrfs_tree_unlock(mid);
5f39d397 1141 free_extent_buffer(mid);
bb803951 1142 mid = NULL;
e089f05c 1143 wret = del_ptr(trans, root, path, level + 1, pslot);
bb803951
CM		 1144 if (wret)
1145 ret = wret;
7bb86316 1146 wret = btrfs_free_extent(trans, root, bytenr, blocksize,
5d4f98a2
YZ		 1147 0, root->root_key.objectid,
1148 level, 0);
bb803951
CM		 1149 if (wret)
1150 ret = wret;
79f95c82
CM		 1151 } else {
1152 /* update the parent key to reflect our changes */
5f39d397
CM		 1153 struct btrfs_disk_key mid_key;
1154 btrfs_node_key(mid, &mid_key, 0);
1155 btrfs_set_node_key(parent, &mid_key, pslot);
1156 btrfs_mark_buffer_dirty(parent);
79f95c82 1157 }
bb803951 1158
79f95c82 1159 /* update the path */
5f39d397
CM		 1160 if (left) {
1161 if (btrfs_header_nritems(left) > orig_slot) {
1162 extent_buffer_get(left);
925baedd 1163 /* left was locked after cow */
5f39d397 1164 path->nodes[level] = left;
bb803951
CM		 1165 path->slots[level + 1] -= 1;
1166 path->slots[level] = orig_slot;
925baedd
CM		 1167 if (mid) {
1168 btrfs_tree_unlock(mid);
5f39d397 1169 free_extent_buffer(mid);
925baedd 1170 }
bb803951 1171 } else {
5f39d397 1172 orig_slot -= btrfs_header_nritems(left);
bb803951
CM		 1173 path->slots[level] = orig_slot;
1174 }
1175 }
79f95c82 1176 /* double check we haven't messed things up */
123abc88 1177 check_block(root, path, level);
e20d96d6 1178 if (orig_ptr !=
5f39d397 1179 btrfs_node_blockptr(path->nodes[level], path->slots[level]))
79f95c82 1180 BUG();
54aa1f4d 1181enospc:
925baedd
CM		 1182 if (right) {
1183 btrfs_tree_unlock(right);
5f39d397 1184 free_extent_buffer(right);
925baedd
CM		 1185 }
1186 if (left) {
1187 if (path->nodes[level] != left)
1188 btrfs_tree_unlock(left);
5f39d397 1189 free_extent_buffer(left);
925baedd 1190 }
bb803951
CM		 1191 return ret;
1192}
1193
d352ac68
CM		 1194/* Node balancing for insertion. Here we only split or push nodes around
1195 * when they are completely full. This is also done top down, so we
1196 * have to be pessimistic.
1197 */
d397712b 1198static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans,
98ed5174
CM		 1199 struct btrfs_root *root,
1200 struct btrfs_path *path, int level)
e66f709b 1201{
5f39d397
CM		 1202 struct extent_buffer *right = NULL;
1203 struct extent_buffer *mid;
1204 struct extent_buffer *left = NULL;
1205 struct extent_buffer *parent = NULL;
e66f709b
CM		 1206 int ret = 0;
1207 int wret;
1208 int pslot;
1209 int orig_slot = path->slots[level];
1210 u64 orig_ptr;
1211
1212 if (level == 0)
1213 return 1;
1214
5f39d397 1215 mid = path->nodes[level];
7bb86316 1216 WARN_ON(btrfs_header_generation(mid) != trans->transid);
e66f709b
CM		 1217 orig_ptr = btrfs_node_blockptr(mid, orig_slot);
1218
1219 if (level < BTRFS_MAX_LEVEL - 1)
5f39d397 1220 parent = path->nodes[level + 1];
e66f709b
CM		 1221 pslot = path->slots[level + 1];
1222
5f39d397 1223 if (!parent)
e66f709b 1224 return 1;
e66f709b 1225
5f39d397 1226 left = read_node_slot(root, parent, pslot - 1);
e66f709b
CM		 1227
1228 /* first, try to make some room in the middle buffer */
5f39d397 1229 if (left) {
e66f709b 1230 u32 left_nr;
925baedd
CM		 1231
1232 btrfs_tree_lock(left);
b4ce94de
CM		 1233 btrfs_set_lock_blocking(left);
1234
5f39d397 1235 left_nr = btrfs_header_nritems(left);
33ade1f8
CM		 1236 if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
1237 wret = 1;
1238 } else {
5f39d397 1239 ret = btrfs_cow_block(trans, root, left, parent,
9fa8cfe7 1240 pslot - 1, &left);
54aa1f4d
CM		 1241 if (ret)
1242 wret = 1;
1243 else {
54aa1f4d 1244 wret = push_node_left(trans, root,
971a1f66 1245 left, mid, 0);
54aa1f4d 1246 }
33ade1f8 1247 }
e66f709b
CM		 1248 if (wret < 0)
1249 ret = wret;
1250 if (wret == 0) {
5f39d397 1251 struct btrfs_disk_key disk_key;
e66f709b 1252 orig_slot += left_nr;
5f39d397
CM		 1253 btrfs_node_key(mid, &disk_key, 0);
1254 btrfs_set_node_key(parent, &disk_key, pslot);
1255 btrfs_mark_buffer_dirty(parent);
1256 if (btrfs_header_nritems(left) > orig_slot) {
1257 path->nodes[level] = left;
e66f709b
CM		 1258 path->slots[level + 1] -= 1;
1259 path->slots[level] = orig_slot;
925baedd 1260 btrfs_tree_unlock(mid);
5f39d397 1261 free_extent_buffer(mid);
e66f709b
CM		 1262 } else {
1263 orig_slot -=
5f39d397 1264 btrfs_header_nritems(left);
e66f709b 1265 path->slots[level] = orig_slot;
925baedd 1266 btrfs_tree_unlock(left);
5f39d397 1267 free_extent_buffer(left);
e66f709b 1268 }
e66f709b
CM		 1269 return 0;
1270 }
925baedd 1271 btrfs_tree_unlock(left);
5f39d397 1272 free_extent_buffer(left);
e66f709b 1273 }
925baedd 1274 right = read_node_slot(root, parent, pslot + 1);
e66f709b
CM		 1275
1276 /*
1277 * then try to empty the right most buffer into the middle
1278 */
5f39d397 1279 if (right) {
33ade1f8 1280 u32 right_nr;
b4ce94de 1281
925baedd 1282 btrfs_tree_lock(right);
b4ce94de
CM		 1283 btrfs_set_lock_blocking(right);
1284
5f39d397 1285 right_nr = btrfs_header_nritems(right);
33ade1f8
CM		 1286 if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
1287 wret = 1;
1288 } else {
5f39d397
CM		 1289 ret = btrfs_cow_block(trans, root, right,
1290 parent, pslot + 1,
9fa8cfe7 1291 &right);
54aa1f4d
CM		 1292 if (ret)
1293 wret = 1;
1294 else {
54aa1f4d 1295 wret = balance_node_right(trans, root,
5f39d397 1296 right, mid);
54aa1f4d 1297 }
33ade1f8 1298 }
e66f709b
CM		 1299 if (wret < 0)
1300 ret = wret;
1301 if (wret == 0) {
5f39d397
CM		 1302 struct btrfs_disk_key disk_key;
1303
1304 btrfs_node_key(right, &disk_key, 0);
1305 btrfs_set_node_key(parent, &disk_key, pslot + 1);
1306 btrfs_mark_buffer_dirty(parent);
1307
1308 if (btrfs_header_nritems(mid) <= orig_slot) {
1309 path->nodes[level] = right;
e66f709b
CM		 1310 path->slots[level + 1] += 1;
1311 path->slots[level] = orig_slot -
5f39d397 1312 btrfs_header_nritems(mid);
925baedd 1313 btrfs_tree_unlock(mid);
5f39d397 1314 free_extent_buffer(mid);
e66f709b 1315 } else {
925baedd 1316 btrfs_tree_unlock(right);
5f39d397 1317 free_extent_buffer(right);
e66f709b 1318 }
e66f709b
CM		 1319 return 0;
1320 }
925baedd 1321 btrfs_tree_unlock(right);
5f39d397 1322 free_extent_buffer(right);
e66f709b 1323 }
e66f709b
CM		 1324 return 1;
1325}
1326
3c69faec 1327/*
d352ac68
CM		 1328 * readahead one full node of leaves, finding things that are close
1329 * to the block in 'slot', and triggering ra on them.
3c69faec 1330 */
c8c42864
CM		 1331static void reada_for_search(struct btrfs_root *root,
1332 struct btrfs_path *path,
1333 int level, int slot, u64 objectid)
3c69faec 1334{
5f39d397 1335 struct extent_buffer *node;
01f46658 1336 struct btrfs_disk_key disk_key;
3c69faec 1337 u32 nritems;
3c69faec 1338 u64 search;
a7175319 1339 u64 target;
6b80053d 1340 u64 nread = 0;
3c69faec 1341 int direction = path->reada;
5f39d397 1342 struct extent_buffer *eb;
6b80053d
CM		 1343 u32 nr;
1344 u32 blocksize;
1345 u32 nscan = 0;
db94535d 1346
a6b6e75e 1347 if (level != 1)
6702ed49
CM		 1348 return;
1349
1350 if (!path->nodes[level])
3c69faec
CM		 1351 return;
1352
5f39d397 1353 node = path->nodes[level];
925baedd 1354
3c69faec 1355 search = btrfs_node_blockptr(node, slot);
6b80053d
CM		 1356 blocksize = btrfs_level_size(root, level - 1);
1357 eb = btrfs_find_tree_block(root, search, blocksize);
5f39d397
CM		 1358 if (eb) {
1359 free_extent_buffer(eb);
3c69faec
CM		 1360 return;
1361 }
1362
a7175319 1363 target = search;
6b80053d 1364
5f39d397 1365 nritems = btrfs_header_nritems(node);
6b80053d 1366 nr = slot;
d397712b 1367 while (1) {
6b80053d
CM		 1368 if (direction < 0) {
1369 if (nr == 0)
1370 break;
1371 nr--;
1372 } else if (direction > 0) {
1373 nr++;
1374 if (nr >= nritems)
1375 break;
3c69faec 1376 }
01f46658
CM		 1377 if (path->reada < 0 && objectid) {
1378 btrfs_node_key(node, &disk_key, nr);
1379 if (btrfs_disk_key_objectid(&disk_key) != objectid)
1380 break;
1381 }
6b80053d 1382 search = btrfs_node_blockptr(node, nr);
a7175319
CM		 1383 if ((search <= target && target - search <= 65536) ||
1384 (search > target && search - target <= 65536)) {
ca7a79ad
CM		 1385 readahead_tree_block(root, search, blocksize,
1386 btrfs_node_ptr_generation(node, nr));
6b80053d
CM		 1387 nread += blocksize;
1388 }
1389 nscan++;
a7175319 1390 if ((nread > 65536 || nscan > 32))
6b80053d 1391 break;
3c69faec
CM		 1392 }
1393}
925baedd 1394
b4ce94de
CM		 1395/*
1396 * returns -EAGAIN if it had to drop the path, or zero if everything was in
1397 * cache
1398 */
1399static noinline int reada_for_balance(struct btrfs_root *root,
1400 struct btrfs_path *path, int level)
1401{
1402 int slot;
1403 int nritems;
1404 struct extent_buffer *parent;
1405 struct extent_buffer *eb;
1406 u64 gen;
1407 u64 block1 = 0;
1408 u64 block2 = 0;
1409 int ret = 0;
1410 int blocksize;
1411
8c594ea8 1412 parent = path->nodes[level + 1];
b4ce94de
CM		 1413 if (!parent)
1414 return 0;
1415
1416 nritems = btrfs_header_nritems(parent);
8c594ea8 1417 slot = path->slots[level + 1];
b4ce94de
CM		 1418 blocksize = btrfs_level_size(root, level);
1419
1420 if (slot > 0) {
1421 block1 = btrfs_node_blockptr(parent, slot - 1);
1422 gen = btrfs_node_ptr_generation(parent, slot - 1);
1423 eb = btrfs_find_tree_block(root, block1, blocksize);
1424 if (eb && btrfs_buffer_uptodate(eb, gen))
1425 block1 = 0;
1426 free_extent_buffer(eb);
1427 }
8c594ea8 1428 if (slot + 1 < nritems) {
b4ce94de
CM		 1429 block2 = btrfs_node_blockptr(parent, slot + 1);
1430 gen = btrfs_node_ptr_generation(parent, slot + 1);
1431 eb = btrfs_find_tree_block(root, block2, blocksize);
1432 if (eb && btrfs_buffer_uptodate(eb, gen))
1433 block2 = 0;
1434 free_extent_buffer(eb);
1435 }
1436 if (block1 || block2) {
1437 ret = -EAGAIN;
8c594ea8
CM		 1438
1439 /* release the whole path */
b4ce94de 1440 btrfs_release_path(root, path);
8c594ea8
CM		 1441
1442 /* read the blocks */
b4ce94de
CM		 1443 if (block1)
1444 readahead_tree_block(root, block1, blocksize, 0);
1445 if (block2)
1446 readahead_tree_block(root, block2, blocksize, 0);
1447
1448 if (block1) {
1449 eb = read_tree_block(root, block1, blocksize, 0);
1450 free_extent_buffer(eb);
1451 }
8c594ea8 1452 if (block2) {
b4ce94de
CM		 1453 eb = read_tree_block(root, block2, blocksize, 0);
1454 free_extent_buffer(eb);
1455 }
1456 }
1457 return ret;
1458}
1459
1460
d352ac68 1461/*
d397712b
CM		 1462 * when we walk down the tree, it is usually safe to unlock the higher layers
1463 * in the tree. The exceptions are when our path goes through slot 0, because
1464 * operations on the tree might require changing key pointers higher up in the
1465 * tree.
d352ac68 1466 *
d397712b
CM		 1467 * callers might also have set path->keep_locks, which tells this code to keep
1468 * the lock if the path points to the last slot in the block. This is part of
1469 * walking through the tree, and selecting the next slot in the higher block.
d352ac68 1470 *
d397712b
CM		 1471 * lowest_unlock sets the lowest level in the tree we're allowed to unlock. so
1472 * if lowest_unlock is 1, level 0 won't be unlocked
d352ac68 1473 */
e02119d5
CM		 1474static noinline void unlock_up(struct btrfs_path *path, int level,
1475 int lowest_unlock)
925baedd
CM		 1476{
1477 int i;
1478 int skip_level = level;
051e1b9f 1479 int no_skips = 0;
925baedd
CM		 1480 struct extent_buffer *t;
1481
1482 for (i = level; i < BTRFS_MAX_LEVEL; i++) {
1483 if (!path->nodes[i])
1484 break;
1485 if (!path->locks[i])
1486 break;
051e1b9f 1487 if (!no_skips && path->slots[i] == 0) {
925baedd
CM		 1488 skip_level = i + 1;
1489 continue;
1490 }
051e1b9f 1491 if (!no_skips && path->keep_locks) {
925baedd
CM		 1492 u32 nritems;
1493 t = path->nodes[i];
1494 nritems = btrfs_header_nritems(t);
051e1b9f 1495 if (nritems < 1 || path->slots[i] >= nritems - 1) {
925baedd
CM		 1496 skip_level = i + 1;
1497 continue;
1498 }
1499 }
051e1b9f
CM		 1500 if (skip_level < i && i >= lowest_unlock)
1501 no_skips = 1;
1502
925baedd
CM		 1503 t = path->nodes[i];
1504 if (i >= lowest_unlock && i > skip_level && path->locks[i]) {
1505 btrfs_tree_unlock(t);
1506 path->locks[i] = 0;
1507 }
1508 }
1509}
1510
b4ce94de
CM		 1511/*
1512 * This releases any locks held in the path starting at level and
1513 * going all the way up to the root.
1514 *
1515 * btrfs_search_slot will keep the lock held on higher nodes in a few
1516 * corner cases, such as COW of the block at slot zero in the node. This
1517 * ignores those rules, and it should only be called when there are no
1518 * more updates to be done higher up in the tree.
1519 */
1520noinline void btrfs_unlock_up_safe(struct btrfs_path *path, int level)
1521{
1522 int i;
1523
5d4f98a2 1524 if (path->keep_locks)
b4ce94de
CM		 1525 return;
1526
1527 for (i = level; i < BTRFS_MAX_LEVEL; i++) {
1528 if (!path->nodes[i])
12f4dacc 1529 continue;
b4ce94de 1530 if (!path->locks[i])
12f4dacc 1531 continue;
b4ce94de
CM		 1532 btrfs_tree_unlock(path->nodes[i]);
1533 path->locks[i] = 0;
1534 }
1535}
1536
c8c42864
CM		 1537/*
1538 * helper function for btrfs_search_slot. The goal is to find a block
1539 * in cache without setting the path to blocking. If we find the block
1540 * we return zero and the path is unchanged.
1541 *
1542 * If we can't find the block, we set the path blocking and do some
1543 * reada. -EAGAIN is returned and the search must be repeated.
1544 */
1545static int
1546read_block_for_search(struct btrfs_trans_handle *trans,
1547 struct btrfs_root *root, struct btrfs_path *p,
1548 struct extent_buffer **eb_ret, int level, int slot,
1549 struct btrfs_key *key)
1550{
1551 u64 blocknr;
1552 u64 gen;
1553 u32 blocksize;
1554 struct extent_buffer *b = *eb_ret;
1555 struct extent_buffer *tmp;
76a05b35 1556 int ret;
c8c42864
CM		 1557
1558 blocknr = btrfs_node_blockptr(b, slot);
1559 gen = btrfs_node_ptr_generation(b, slot);
1560 blocksize = btrfs_level_size(root, level - 1);
1561
1562 tmp = btrfs_find_tree_block(root, blocknr, blocksize);
1563 if (tmp && btrfs_buffer_uptodate(tmp, gen)) {
76a05b35
CM		 1564 /*
1565 * we found an up to date block without sleeping, return
1566 * right away
1567 */
c8c42864
CM		 1568 *eb_ret = tmp;
1569 return 0;
1570 }
1571
1572 /*
1573 * reduce lock contention at high levels
1574 * of the btree by dropping locks before
76a05b35
CM		 1575 * we read. Don't release the lock on the current
1576 * level because we need to walk this node to figure
1577 * out which blocks to read.
c8c42864 1578 */
8c594ea8
CM		 1579 btrfs_unlock_up_safe(p, level + 1);
1580 btrfs_set_path_blocking(p);
1581
c8c42864
CM		 1582 if (tmp)
1583 free_extent_buffer(tmp);
1584 if (p->reada)
1585 reada_for_search(root, p, level, slot, key->objectid);
1586
8c594ea8 1587 btrfs_release_path(NULL, p);
76a05b35
CM		 1588
1589 ret = -EAGAIN;
c8c42864 1590 tmp = read_tree_block(root, blocknr, blocksize, gen);
76a05b35
CM		 1591 if (tmp) {
1592 /*
1593 * If the read above didn't mark this buffer up to date,
1594 * it will never end up being up to date. Set ret to EIO now
1595 * and give up so that our caller doesn't loop forever
1596 * on our EAGAINs.
1597 */
1598 if (!btrfs_buffer_uptodate(tmp, 0))
1599 ret = -EIO;
c8c42864 1600 free_extent_buffer(tmp);
76a05b35
CM		 1601 }
1602 return ret;
c8c42864
CM		 1603}
1604
1605/*
1606 * helper function for btrfs_search_slot. This does all of the checks
1607 * for node-level blocks and does any balancing required based on
1608 * the ins_len.
1609 *
1610 * If no extra work was required, zero is returned. If we had to
1611 * drop the path, -EAGAIN is returned and btrfs_search_slot must
1612 * start over
1613 */
1614static int
1615setup_nodes_for_search(struct btrfs_trans_handle *trans,
1616 struct btrfs_root *root, struct btrfs_path *p,
1617 struct extent_buffer *b, int level, int ins_len)
1618{
1619 int ret;
1620 if ((p->search_for_split || ins_len > 0) && btrfs_header_nritems(b) >=
1621 BTRFS_NODEPTRS_PER_BLOCK(root) - 3) {
1622 int sret;
1623
1624 sret = reada_for_balance(root, p, level);
1625 if (sret)
1626 goto again;
1627
1628 btrfs_set_path_blocking(p);
1629 sret = split_node(trans, root, p, level);
1630 btrfs_clear_path_blocking(p, NULL);
1631
1632 BUG_ON(sret > 0);
1633 if (sret) {
1634 ret = sret;
1635 goto done;
1636 }
1637 b = p->nodes[level];
1638 } else if (ins_len < 0 && btrfs_header_nritems(b) <
cfbb9308 1639 BTRFS_NODEPTRS_PER_BLOCK(root) / 2) {
c8c42864
CM		 1640 int sret;
1641
1642 sret = reada_for_balance(root, p, level);
1643 if (sret)
1644 goto again;
1645
1646 btrfs_set_path_blocking(p);
1647 sret = balance_level(trans, root, p, level);
1648 btrfs_clear_path_blocking(p, NULL);
1649
1650 if (sret) {
1651 ret = sret;
1652 goto done;
1653 }
1654 b = p->nodes[level];
1655 if (!b) {
1656 btrfs_release_path(NULL, p);
1657 goto again;
1658 }
1659 BUG_ON(btrfs_header_nritems(b) == 1);
1660 }
1661 return 0;
1662
1663again:
1664 ret = -EAGAIN;
1665done:
1666 return ret;
1667}
1668
74123bd7
CM		 1669/*
1670 * look for key in the tree. path is filled in with nodes along the way
1671 * if key is found, we return zero and you can find the item in the leaf
1672 * level of the path (level 0)
1673 *
1674 * If the key isn't found, the path points to the slot where it should
aa5d6bed
CM		 1675 * be inserted, and 1 is returned. If there are other errors during the
1676 * search a negative error number is returned.
97571fd0
CM		 1677 *
1678 * if ins_len > 0, nodes and leaves will be split as we walk down the
1679 * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if
1680 * possible)
74123bd7 1681 */
e089f05c
CM		 1682int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root
1683 *root, struct btrfs_key *key, struct btrfs_path *p, int
1684 ins_len, int cow)
be0e5c09 1685{
5f39d397 1686 struct extent_buffer *b;
be0e5c09
CM		 1687 int slot;
1688 int ret;
33c66f43 1689 int err;
be0e5c09 1690 int level;
925baedd 1691 int lowest_unlock = 1;
9f3a7427
CM		 1692 u8 lowest_level = 0;
1693
6702ed49 1694 lowest_level = p->lowest_level;
323ac95b 1695 WARN_ON(lowest_level && ins_len > 0);
22b0ebda 1696 WARN_ON(p->nodes[0] != NULL);
25179201 1697
925baedd
CM		 1698 if (ins_len < 0)
1699 lowest_unlock = 2;
65b51a00 1700
bb803951 1701again:
5d4f98a2
YZ		 1702 if (p->search_commit_root) {
1703 b = root->commit_root;
1704 extent_buffer_get(b);
1705 if (!p->skip_locking)
1706 btrfs_tree_lock(b);
1707 } else {
1708 if (p->skip_locking)
1709 b = btrfs_root_node(root);
1710 else
1711 b = btrfs_lock_root_node(root);
1712 }
925baedd 1713
eb60ceac 1714 while (b) {
5f39d397 1715 level = btrfs_header_level(b);
65b51a00
CM		 1716
1717 /*
1718 * setup the path here so we can release it under lock
1719 * contention with the cow code
1720 */
1721 p->nodes[level] = b;
1722 if (!p->skip_locking)
1723 p->locks[level] = 1;
1724
02217ed2 1725 if (cow) {
c8c42864
CM		 1726 /*
1727 * if we don't really need to cow this block
1728 * then we don't want to set the path blocking,
1729 * so we test it here
1730 */
5d4f98a2 1731 if (!should_cow_block(trans, root, b))
65b51a00 1732 goto cow_done;
5d4f98a2 1733
b4ce94de
CM		 1734 btrfs_set_path_blocking(p);
1735
33c66f43
YZ		 1736 err = btrfs_cow_block(trans, root, b,
1737 p->nodes[level + 1],
1738 p->slots[level + 1], &b);
1739 if (err) {
5f39d397 1740 free_extent_buffer(b);
33c66f43 1741 ret = err;
65b51a00 1742 goto done;
54aa1f4d 1743 }
02217ed2 1744 }
65b51a00 1745cow_done:
02217ed2 1746 BUG_ON(!cow && ins_len);
5f39d397 1747 if (level != btrfs_header_level(b))
2c90e5d6 1748 WARN_ON(1);
5f39d397 1749 level = btrfs_header_level(b);
65b51a00 1750
eb60ceac 1751 p->nodes[level] = b;
5cd57b2c
CM		 1752 if (!p->skip_locking)
1753 p->locks[level] = 1;
65b51a00 1754
4008c04a 1755 btrfs_clear_path_blocking(p, NULL);
b4ce94de
CM		 1756
1757 /*
1758 * we have a lock on b and as long as we aren't changing
1759 * the tree, there is no way to for the items in b to change.
1760 * It is safe to drop the lock on our parent before we
1761 * go through the expensive btree search on b.
1762 *
1763 * If cow is true, then we might be changing slot zero,
1764 * which may require changing the parent. So, we can't
1765 * drop the lock until after we know which slot we're
1766 * operating on.
1767 */
1768 if (!cow)
1769 btrfs_unlock_up_safe(p, level + 1);
1770
123abc88 1771 ret = check_block(root, p, level);
65b51a00
CM		 1772 if (ret) {
1773 ret = -1;
1774 goto done;
1775 }
925baedd 1776
5f39d397 1777 ret = bin_search(b, key, level, &slot);
b4ce94de 1778
5f39d397 1779 if (level != 0) {
33c66f43
YZ		 1780 int dec = 0;
1781 if (ret && slot > 0) {
1782 dec = 1;
be0e5c09 1783 slot -= 1;
33c66f43 1784 }
be0e5c09 1785 p->slots[level] = slot;
33c66f43 1786 err = setup_nodes_for_search(trans, root, p, b, level,
c8c42864 1787 ins_len);
33c66f43 1788 if (err == -EAGAIN)
c8c42864 1789 goto again;
33c66f43
YZ		 1790 if (err) {
1791 ret = err;
c8c42864 1792 goto done;
33c66f43 1793 }
c8c42864
CM		 1794 b = p->nodes[level];
1795 slot = p->slots[level];
b4ce94de 1796
f9efa9c7
CM		 1797 unlock_up(p, level, lowest_unlock);
1798
925baedd 1799 if (level == lowest_level) {
33c66f43
YZ		 1800 if (dec)
1801 p->slots[level]++;
5b21f2ed 1802 goto done;
925baedd 1803 }
ca7a79ad 1804
33c66f43 1805 err = read_block_for_search(trans, root, p,
c8c42864 1806 &b, level, slot, key);
33c66f43 1807 if (err == -EAGAIN)
c8c42864 1808 goto again;
33c66f43
YZ		 1809 if (err) {
1810 ret = err;
76a05b35 1811 goto done;
33c66f43 1812 }
76a05b35 1813
b4ce94de 1814 if (!p->skip_locking) {
4008c04a 1815 btrfs_clear_path_blocking(p, NULL);
33c66f43 1816 err = btrfs_try_spin_lock(b);
b4ce94de 1817
33c66f43 1818 if (!err) {
b4ce94de
CM		 1819 btrfs_set_path_blocking(p);
1820 btrfs_tree_lock(b);
4008c04a 1821 btrfs_clear_path_blocking(p, b);
b4ce94de
CM		 1822 }
1823 }
be0e5c09
CM		 1824 } else {
1825 p->slots[level] = slot;
87b29b20
YZ		 1826 if (ins_len > 0 &&
1827 btrfs_leaf_free_space(root, b) < ins_len) {
b4ce94de 1828 btrfs_set_path_blocking(p);
33c66f43
YZ		 1829 err = split_leaf(trans, root, key,
1830 p, ins_len, ret == 0);
4008c04a 1831 btrfs_clear_path_blocking(p, NULL);
b4ce94de 1832
33c66f43
YZ		 1833 BUG_ON(err > 0);
1834 if (err) {
1835 ret = err;
65b51a00
CM		 1836 goto done;
1837 }
5c680ed6 1838 }
459931ec
CM		 1839 if (!p->search_for_split)
1840 unlock_up(p, level, lowest_unlock);
65b51a00 1841 goto done;
be0e5c09
CM		 1842 }
1843 }
65b51a00
CM		 1844 ret = 1;
1845done:
b4ce94de
CM		 1846 /*
1847 * we don't really know what they plan on doing with the path
1848 * from here on, so for now just mark it as blocking
1849 */
b9473439
CM		 1850 if (!p->leave_spinning)
1851 btrfs_set_path_blocking(p);
76a05b35
CM		 1852 if (ret < 0)
1853 btrfs_release_path(root, p);
65b51a00 1854 return ret;
be0e5c09
CM		 1855}
1856
74123bd7
CM		 1857/*
1858 * adjust the pointers going up the tree, starting at level
1859 * making sure the right key of each node is points to 'key'.
1860 * This is used after shifting pointers to the left, so it stops
1861 * fixing up pointers when a given leaf/node is not in slot 0 of the
1862 * higher levels
aa5d6bed
CM		 1863 *
1864 * If this fails to write a tree block, it returns -1, but continues
1865 * fixing up the blocks in ram so the tree is consistent.
74123bd7 1866 */
5f39d397
CM		 1867static int fixup_low_keys(struct btrfs_trans_handle *trans,
1868 struct btrfs_root *root, struct btrfs_path *path,
1869 struct btrfs_disk_key *key, int level)
be0e5c09
CM		 1870{
1871 int i;
aa5d6bed 1872 int ret = 0;
5f39d397
CM		 1873 struct extent_buffer *t;
1874
234b63a0 1875 for (i = level; i < BTRFS_MAX_LEVEL; i++) {
be0e5c09 1876 int tslot = path->slots[i];
eb60ceac 1877 if (!path->nodes[i])
be0e5c09 1878 break;
5f39d397
CM		 1879 t = path->nodes[i];
1880 btrfs_set_node_key(t, key, tslot);
d6025579 1881 btrfs_mark_buffer_dirty(path->nodes[i]);
be0e5c09
CM		 1882 if (tslot != 0)
1883 break;
1884 }
aa5d6bed 1885 return ret;
be0e5c09
CM		 1886}
1887
31840ae1
ZY		 1888/*
1889 * update item key.
1890 *
1891 * This function isn't completely safe. It's the caller's responsibility
1892 * that the new key won't break the order
1893 */
1894int btrfs_set_item_key_safe(struct btrfs_trans_handle *trans,
1895 struct btrfs_root *root, struct btrfs_path *path,
1896 struct btrfs_key *new_key)
1897{
1898 struct btrfs_disk_key disk_key;
1899 struct extent_buffer *eb;
1900 int slot;
1901
1902 eb = path->nodes[0];
1903 slot = path->slots[0];
1904 if (slot > 0) {
1905 btrfs_item_key(eb, &disk_key, slot - 1);
1906 if (comp_keys(&disk_key, new_key) >= 0)
1907 return -1;
1908 }
1909 if (slot < btrfs_header_nritems(eb) - 1) {
1910 btrfs_item_key(eb, &disk_key, slot + 1);
1911 if (comp_keys(&disk_key, new_key) <= 0)
1912 return -1;
1913 }
1914
1915 btrfs_cpu_key_to_disk(&disk_key, new_key);
1916 btrfs_set_item_key(eb, &disk_key, slot);
1917 btrfs_mark_buffer_dirty(eb);
1918 if (slot == 0)
1919 fixup_low_keys(trans, root, path, &disk_key, 1);
1920 return 0;
1921}
1922
74123bd7
CM		 1923/*
1924 * try to push data from one node into the next node left in the
79f95c82 1925 * tree.
aa5d6bed
CM		 1926 *
1927 * returns 0 if some ptrs were pushed left, < 0 if there was some horrible
1928 * error, and > 0 if there was no room in the left hand block.
74123bd7 1929 */
98ed5174
CM		 1930static int push_node_left(struct btrfs_trans_handle *trans,
1931 struct btrfs_root *root, struct extent_buffer *dst,
971a1f66 1932 struct extent_buffer *src, int empty)
be0e5c09 1933{
be0e5c09 1934 int push_items = 0;
bb803951
CM		 1935 int src_nritems;
1936 int dst_nritems;
aa5d6bed 1937 int ret = 0;
be0e5c09 1938
5f39d397
CM		 1939 src_nritems = btrfs_header_nritems(src);
1940 dst_nritems = btrfs_header_nritems(dst);
123abc88 1941 push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
7bb86316
CM		 1942 WARN_ON(btrfs_header_generation(src) != trans->transid);
1943 WARN_ON(btrfs_header_generation(dst) != trans->transid);
54aa1f4d 1944
bce4eae9 1945 if (!empty && src_nritems <= 8)
971a1f66
CM		 1946 return 1;
1947
d397712b 1948 if (push_items <= 0)
be0e5c09
CM		 1949 return 1;
1950
bce4eae9 1951 if (empty) {
971a1f66 1952 push_items = min(src_nritems, push_items);
bce4eae9
CM		 1953 if (push_items < src_nritems) {
1954 /* leave at least 8 pointers in the node if
1955 * we aren't going to empty it
1956 */
1957 if (src_nritems - push_items < 8) {
1958 if (push_items <= 8)
1959 return 1;
1960 push_items -= 8;
1961 }
1962 }
1963 } else
1964 push_items = min(src_nritems - 8, push_items);
79f95c82 1965
5f39d397
CM		 1966 copy_extent_buffer(dst, src,
1967 btrfs_node_key_ptr_offset(dst_nritems),
1968 btrfs_node_key_ptr_offset(0),
d397712b 1969 push_items * sizeof(struct btrfs_key_ptr));
5f39d397 1970
bb803951 1971 if (push_items < src_nritems) {
5f39d397
CM		 1972 memmove_extent_buffer(src, btrfs_node_key_ptr_offset(0),
1973 btrfs_node_key_ptr_offset(push_items),
1974 (src_nritems - push_items) *
1975 sizeof(struct btrfs_key_ptr));
1976 }
1977 btrfs_set_header_nritems(src, src_nritems - push_items);
1978 btrfs_set_header_nritems(dst, dst_nritems + push_items);
1979 btrfs_mark_buffer_dirty(src);
1980 btrfs_mark_buffer_dirty(dst);
31840ae1 1981
79f95c82
CM		 1982 return ret;
1983}
1984
1985/*
1986 * try to push data from one node into the next node right in the
1987 * tree.
1988 *
1989 * returns 0 if some ptrs were pushed, < 0 if there was some horrible
1990 * error, and > 0 if there was no room in the right hand block.
1991 *
1992 * this will only push up to 1/2 the contents of the left node over
1993 */
5f39d397
CM		 1994static int balance_node_right(struct btrfs_trans_handle *trans,
1995 struct btrfs_root *root,
1996 struct extent_buffer *dst,
1997 struct extent_buffer *src)
79f95c82 1998{
79f95c82
CM		 1999 int push_items = 0;
2000 int max_push;
2001 int src_nritems;
2002 int dst_nritems;
2003 int ret = 0;
79f95c82 2004
7bb86316
CM		 2005 WARN_ON(btrfs_header_generation(src) != trans->transid);
2006 WARN_ON(btrfs_header_generation(dst) != trans->transid);
2007
5f39d397
CM		 2008 src_nritems = btrfs_header_nritems(src);
2009 dst_nritems = btrfs_header_nritems(dst);
123abc88 2010 push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
d397712b 2011 if (push_items <= 0)
79f95c82 2012 return 1;
bce4eae9 2013
d397712b 2014 if (src_nritems < 4)
bce4eae9 2015 return 1;
79f95c82
CM		 2016
2017 max_push = src_nritems / 2 + 1;
2018 /* don't try to empty the node */
d397712b 2019 if (max_push >= src_nritems)
79f95c82 2020 return 1;
252c38f0 2021
79f95c82
CM		 2022 if (max_push < push_items)
2023 push_items = max_push;
2024
5f39d397
CM		 2025 memmove_extent_buffer(dst, btrfs_node_key_ptr_offset(push_items),
2026 btrfs_node_key_ptr_offset(0),
2027 (dst_nritems) *
2028 sizeof(struct btrfs_key_ptr));
d6025579 2029
5f39d397
CM		 2030 copy_extent_buffer(dst, src,
2031 btrfs_node_key_ptr_offset(0),
2032 btrfs_node_key_ptr_offset(src_nritems - push_items),
d397712b 2033 push_items * sizeof(struct btrfs_key_ptr));
79f95c82 2034
5f39d397
CM		 2035 btrfs_set_header_nritems(src, src_nritems - push_items);
2036 btrfs_set_header_nritems(dst, dst_nritems + push_items);
79f95c82 2037
5f39d397
CM		 2038 btrfs_mark_buffer_dirty(src);
2039 btrfs_mark_buffer_dirty(dst);
31840ae1 2040
aa5d6bed 2041 return ret;
be0e5c09
CM		 2042}
2043
97571fd0
CM		 2044/*
2045 * helper function to insert a new root level in the tree.
2046 * A new node is allocated, and a single item is inserted to
2047 * point to the existing root
aa5d6bed
CM		 2048 *
2049 * returns zero on success or < 0 on failure.
97571fd0 2050 */
d397712b 2051static noinline int insert_new_root(struct btrfs_trans_handle *trans,
5f39d397
CM		 2052 struct btrfs_root *root,
2053 struct btrfs_path *path, int level)
5c680ed6 2054{
7bb86316 2055 u64 lower_gen;
5f39d397
CM		 2056 struct extent_buffer *lower;
2057 struct extent_buffer *c;
925baedd 2058 struct extent_buffer *old;
5f39d397 2059 struct btrfs_disk_key lower_key;
5c680ed6
CM		 2060
2061 BUG_ON(path->nodes[level]);
2062 BUG_ON(path->nodes[level-1] != root->node);
2063
7bb86316
CM		 2064 lower = path->nodes[level-1];
2065 if (level == 1)
2066 btrfs_item_key(lower, &lower_key, 0);
2067 else
2068 btrfs_node_key(lower, &lower_key, 0);
2069
31840ae1 2070 c = btrfs_alloc_free_block(trans, root, root->nodesize, 0,
5d4f98a2 2071 root->root_key.objectid, &lower_key,
ad3d81ba 2072 level, root->node->start, 0);
5f39d397
CM		 2073 if (IS_ERR(c))
2074 return PTR_ERR(c);
925baedd 2075
5d4f98a2 2076 memset_extent_buffer(c, 0, 0, sizeof(struct btrfs_header));
5f39d397
CM		 2077 btrfs_set_header_nritems(c, 1);
2078 btrfs_set_header_level(c, level);
db94535d 2079 btrfs_set_header_bytenr(c, c->start);
5f39d397 2080 btrfs_set_header_generation(c, trans->transid);
5d4f98a2 2081 btrfs_set_header_backref_rev(c, BTRFS_MIXED_BACKREF_REV);
5f39d397 2082 btrfs_set_header_owner(c, root->root_key.objectid);
5f39d397
CM		 2083
2084 write_extent_buffer(c, root->fs_info->fsid,
2085 (unsigned long)btrfs_header_fsid(c),
2086 BTRFS_FSID_SIZE);
e17cade2
CM		 2087
2088 write_extent_buffer(c, root->fs_info->chunk_tree_uuid,
2089 (unsigned long)btrfs_header_chunk_tree_uuid(c),
2090 BTRFS_UUID_SIZE);
2091
5f39d397 2092 btrfs_set_node_key(c, &lower_key, 0);
db94535d 2093 btrfs_set_node_blockptr(c, 0, lower->start);
7bb86316 2094 lower_gen = btrfs_header_generation(lower);
31840ae1 2095 WARN_ON(lower_gen != trans->transid);
7bb86316
CM		 2096
2097 btrfs_set_node_ptr_generation(c, 0, lower_gen);
d5719762 2098
5f39d397 2099 btrfs_mark_buffer_dirty(c);
d5719762 2100
925baedd
CM		 2101 spin_lock(&root->node_lock);
2102 old = root->node;
5f39d397 2103 root->node = c;
925baedd
CM		 2104 spin_unlock(&root->node_lock);
2105
2106 /* the super has an extra ref to root->node */
2107 free_extent_buffer(old);
2108
0b86a832 2109 add_root_to_dirty_list(root);
5f39d397
CM		 2110 extent_buffer_get(c);
2111 path->nodes[level] = c;
925baedd 2112 path->locks[level] = 1;
5c680ed6
CM		 2113 path->slots[level] = 0;
2114 return 0;
2115}
2116
74123bd7
CM		 2117/*
2118 * worker function to insert a single pointer in a node.
2119 * the node should have enough room for the pointer already
97571fd0 2120 *
74123bd7
CM		 2121 * slot and level indicate where you want the key to go, and
2122 * blocknr is the block the key points to.
aa5d6bed
CM		 2123 *
2124 * returns zero on success and < 0 on any error
74123bd7 2125 */
e089f05c
CM		 2126static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root
2127 *root, struct btrfs_path *path, struct btrfs_disk_key
db94535d 2128 *key, u64 bytenr, int slot, int level)
74123bd7 2129{
5f39d397 2130 struct extent_buffer *lower;
74123bd7 2131 int nritems;
5c680ed6
CM		 2132
2133 BUG_ON(!path->nodes[level]);
5f39d397
CM		 2134 lower = path->nodes[level];
2135 nritems = btrfs_header_nritems(lower);
c293498b 2136 BUG_ON(slot > nritems);
123abc88 2137 if (nritems == BTRFS_NODEPTRS_PER_BLOCK(root))
74123bd7
CM		 2138 BUG();
2139 if (slot != nritems) {
5f39d397
CM		 2140 memmove_extent_buffer(lower,
2141 btrfs_node_key_ptr_offset(slot + 1),
2142 btrfs_node_key_ptr_offset(slot),
d6025579 2143 (nritems - slot) * sizeof(struct btrfs_key_ptr));
74123bd7 2144 }
5f39d397 2145 btrfs_set_node_key(lower, key, slot);
db94535d 2146 btrfs_set_node_blockptr(lower, slot, bytenr);
74493f7a
CM		 2147 WARN_ON(trans->transid == 0);
2148 btrfs_set_node_ptr_generation(lower, slot, trans->transid);
5f39d397
CM		 2149 btrfs_set_header_nritems(lower, nritems + 1);
2150 btrfs_mark_buffer_dirty(lower);
74123bd7
CM		 2151 return 0;
2152}
2153
97571fd0
CM		 2154/*
2155 * split the node at the specified level in path in two.
2156 * The path is corrected to point to the appropriate node after the split
2157 *
2158 * Before splitting this tries to make some room in the node by pushing
2159 * left and right, if either one works, it returns right away.
aa5d6bed
CM		 2160 *
2161 * returns 0 on success and < 0 on failure
97571fd0 2162 */
e02119d5
CM		 2163static noinline int split_node(struct btrfs_trans_handle *trans,
2164 struct btrfs_root *root,
2165 struct btrfs_path *path, int level)
be0e5c09 2166{
5f39d397
CM		 2167 struct extent_buffer *c;
2168 struct extent_buffer *split;
2169 struct btrfs_disk_key disk_key;
be0e5c09 2170 int mid;
5c680ed6 2171 int ret;
aa5d6bed 2172 int wret;
7518a238 2173 u32 c_nritems;
eb60ceac 2174
5f39d397 2175 c = path->nodes[level];
7bb86316 2176 WARN_ON(btrfs_header_generation(c) != trans->transid);
5f39d397 2177 if (c == root->node) {
5c680ed6 2178 /* trying to split the root, lets make a new one */
e089f05c 2179 ret = insert_new_root(trans, root, path, level + 1);
5c680ed6
CM		 2180 if (ret)
2181 return ret;
b3612421 2182 } else {
e66f709b 2183 ret = push_nodes_for_insert(trans, root, path, level);
5f39d397
CM		 2184 c = path->nodes[level];
2185 if (!ret && btrfs_header_nritems(c) <
c448acf0 2186 BTRFS_NODEPTRS_PER_BLOCK(root) - 3)
e66f709b 2187 return 0;
54aa1f4d
CM		 2188 if (ret < 0)
2189 return ret;
be0e5c09 2190 }
e66f709b 2191
5f39d397 2192 c_nritems = btrfs_header_nritems(c);
5d4f98a2
YZ		 2193 mid = (c_nritems + 1) / 2;
2194 btrfs_node_key(c, &disk_key, mid);
7bb86316 2195
5d4f98a2 2196 split = btrfs_alloc_free_block(trans, root, root->nodesize, 0,
31840ae1 2197 root->root_key.objectid,
5d4f98a2 2198 &disk_key, level, c->start, 0);
5f39d397
CM		 2199 if (IS_ERR(split))
2200 return PTR_ERR(split);
2201
5d4f98a2 2202 memset_extent_buffer(split, 0, 0, sizeof(struct btrfs_header));
5f39d397 2203 btrfs_set_header_level(split, btrfs_header_level(c));
db94535d 2204 btrfs_set_header_bytenr(split, split->start);
5f39d397 2205 btrfs_set_header_generation(split, trans->transid);
5d4f98a2 2206 btrfs_set_header_backref_rev(split, BTRFS_MIXED_BACKREF_REV);
5f39d397
CM		 2207 btrfs_set_header_owner(split, root->root_key.objectid);
2208 write_extent_buffer(split, root->fs_info->fsid,
2209 (unsigned long)btrfs_header_fsid(split),
2210 BTRFS_FSID_SIZE);
e17cade2
CM		 2211 write_extent_buffer(split, root->fs_info->chunk_tree_uuid,
2212 (unsigned long)btrfs_header_chunk_tree_uuid(split),
2213 BTRFS_UUID_SIZE);
54aa1f4d 2214
5f39d397
CM		 2215
2216 copy_extent_buffer(split, c,
2217 btrfs_node_key_ptr_offset(0),
2218 btrfs_node_key_ptr_offset(mid),
2219 (c_nritems - mid) * sizeof(struct btrfs_key_ptr));
2220 btrfs_set_header_nritems(split, c_nritems - mid);
2221 btrfs_set_header_nritems(c, mid);
aa5d6bed
CM		 2222 ret = 0;
2223
5f39d397
CM		 2224 btrfs_mark_buffer_dirty(c);
2225 btrfs_mark_buffer_dirty(split);
2226
db94535d 2227 wret = insert_ptr(trans, root, path, &disk_key, split->start,
5f39d397 2228 path->slots[level + 1] + 1,
123abc88 2229 level + 1);
aa5d6bed
CM		 2230 if (wret)
2231 ret = wret;
2232
5de08d7d 2233 if (path->slots[level] >= mid) {
5c680ed6 2234 path->slots[level] -= mid;
925baedd 2235 btrfs_tree_unlock(c);
5f39d397
CM		 2236 free_extent_buffer(c);
2237 path->nodes[level] = split;
5c680ed6
CM		 2238 path->slots[level + 1] += 1;
2239 } else {
925baedd 2240 btrfs_tree_unlock(split);
5f39d397 2241 free_extent_buffer(split);
be0e5c09 2242 }
aa5d6bed 2243 return ret;
be0e5c09
CM		 2244}
2245
74123bd7
CM		 2246/*
2247 * how many bytes are required to store the items in a leaf. start
2248 * and nr indicate which items in the leaf to check. This totals up the
2249 * space used both by the item structs and the item data
2250 */
5f39d397 2251static int leaf_space_used(struct extent_buffer *l, int start, int nr)
be0e5c09
CM		 2252{
2253 int data_len;
5f39d397 2254 int nritems = btrfs_header_nritems(l);
d4dbff95 2255 int end = min(nritems, start + nr) - 1;
be0e5c09
CM		 2256
2257 if (!nr)
2258 return 0;
5f39d397
CM		 2259 data_len = btrfs_item_end_nr(l, start);
2260 data_len = data_len - btrfs_item_offset_nr(l, end);
0783fcfc 2261 data_len += sizeof(struct btrfs_item) * nr;
d4dbff95 2262 WARN_ON(data_len < 0);
be0e5c09
CM		 2263 return data_len;
2264}
2265
d4dbff95
CM		 2266/*
2267 * The space between the end of the leaf items and
2268 * the start of the leaf data. IOW, how much room
2269 * the leaf has left for both items and data
2270 */
d397712b 2271noinline int btrfs_leaf_free_space(struct btrfs_root *root,
e02119d5 2272 struct extent_buffer *leaf)
d4dbff95 2273{
5f39d397
CM		 2274 int nritems = btrfs_header_nritems(leaf);
2275 int ret;
2276 ret = BTRFS_LEAF_DATA_SIZE(root) - leaf_space_used(leaf, 0, nritems);
2277 if (ret < 0) {
d397712b
CM		 2278 printk(KERN_CRIT "leaf free space ret %d, leaf data size %lu, "
2279 "used %d nritems %d\n",
ae2f5411 2280 ret, (unsigned long) BTRFS_LEAF_DATA_SIZE(root),
5f39d397
CM		 2281 leaf_space_used(leaf, 0, nritems), nritems);
2282 }
2283 return ret;
d4dbff95
CM		 2284}
2285
44871b1b
CM		 2286static noinline int __push_leaf_right(struct btrfs_trans_handle *trans,
2287 struct btrfs_root *root,
2288 struct btrfs_path *path,
2289 int data_size, int empty,
2290 struct extent_buffer *right,
2291 int free_space, u32 left_nritems)
00ec4c51 2292{
5f39d397 2293 struct extent_buffer *left = path->nodes[0];
44871b1b 2294 struct extent_buffer *upper = path->nodes[1];
5f39d397 2295 struct btrfs_disk_key disk_key;
00ec4c51 2296 int slot;
34a38218 2297 u32 i;
00ec4c51
CM		 2298 int push_space = 0;
2299 int push_items = 0;
0783fcfc 2300 struct btrfs_item *item;
34a38218 2301 u32 nr;
7518a238 2302 u32 right_nritems;
5f39d397 2303 u32 data_end;
db94535d 2304 u32 this_item_size;
00ec4c51 2305
34a38218
CM		 2306 if (empty)
2307 nr = 0;
2308 else
2309 nr = 1;
2310
31840ae1 2311 if (path->slots[0] >= left_nritems)
87b29b20 2312 push_space += data_size;
31840ae1 2313
44871b1b 2314 slot = path->slots[1];
34a38218
CM		 2315 i = left_nritems - 1;
2316 while (i >= nr) {
5f39d397 2317 item = btrfs_item_nr(left, i);
db94535d 2318
31840ae1
ZY		 2319 if (!empty && push_items > 0) {
2320 if (path->slots[0] > i)
2321 break;
2322 if (path->slots[0] == i) {
2323 int space = btrfs_leaf_free_space(root, left);
2324 if (space + push_space * 2 > free_space)
2325 break;
2326 }
2327 }
2328
00ec4c51 2329 if (path->slots[0] == i)
87b29b20 2330 push_space += data_size;
db94535d
CM		 2331
2332 if (!left->map_token) {
2333 map_extent_buffer(left, (unsigned long)item,
2334 sizeof(struct btrfs_item),
2335 &left->map_token, &left->kaddr,
2336 &left->map_start, &left->map_len,
2337 KM_USER1);
2338 }
2339
2340 this_item_size = btrfs_item_size(left, item);
2341 if (this_item_size + sizeof(*item) + push_space > free_space)
00ec4c51 2342 break;
31840ae1 2343
00ec4c51 2344 push_items++;
db94535d 2345 push_space += this_item_size + sizeof(*item);
34a38218
CM		 2346 if (i == 0)
2347 break;
2348 i--;
db94535d
CM		 2349 }
2350 if (left->map_token) {
2351 unmap_extent_buffer(left, left->map_token, KM_USER1);
2352 left->map_token = NULL;
00ec4c51 2353 }
5f39d397 2354
925baedd
CM		 2355 if (push_items == 0)
2356 goto out_unlock;
5f39d397 2357
34a38218 2358 if (!empty && push_items == left_nritems)
a429e513 2359 WARN_ON(1);
5f39d397 2360
00ec4c51 2361 /* push left to right */
5f39d397 2362 right_nritems = btrfs_header_nritems(right);
34a38218 2363
5f39d397 2364 push_space = btrfs_item_end_nr(left, left_nritems - push_items);
123abc88 2365 push_space -= leaf_data_end(root, left);
5f39d397 2366
00ec4c51 2367 /* make room in the right data area */
5f39d397
CM		 2368 data_end = leaf_data_end(root, right);
2369 memmove_extent_buffer(right,
2370 btrfs_leaf_data(right) + data_end - push_space,
2371 btrfs_leaf_data(right) + data_end,
2372 BTRFS_LEAF_DATA_SIZE(root) - data_end);
2373
00ec4c51 2374 /* copy from the left data area */
5f39d397 2375 copy_extent_buffer(right, left, btrfs_leaf_data(right) +
d6025579
CM		 2376 BTRFS_LEAF_DATA_SIZE(root) - push_space,
2377 btrfs_leaf_data(left) + leaf_data_end(root, left),
2378 push_space);
5f39d397
CM		 2379
2380 memmove_extent_buffer(right, btrfs_item_nr_offset(push_items),
2381 btrfs_item_nr_offset(0),
2382 right_nritems * sizeof(struct btrfs_item));
2383
00ec4c51 2384 /* copy the items from left to right */
5f39d397
CM		 2385 copy_extent_buffer(right, left, btrfs_item_nr_offset(0),
2386 btrfs_item_nr_offset(left_nritems - push_items),
2387 push_items * sizeof(struct btrfs_item));
00ec4c51
CM		 2388
2389 /* update the item pointers */
7518a238 2390 right_nritems += push_items;
5f39d397 2391 btrfs_set_header_nritems(right, right_nritems);
123abc88 2392 push_space = BTRFS_LEAF_DATA_SIZE(root);
7518a238 2393 for (i = 0; i < right_nritems; i++) {
5f39d397 2394 item = btrfs_item_nr(right, i);
db94535d
CM		 2395 if (!right->map_token) {
2396 map_extent_buffer(right, (unsigned long)item,
2397 sizeof(struct btrfs_item),
2398 &right->map_token, &right->kaddr,
2399 &right->map_start, &right->map_len,
2400 KM_USER1);
2401 }
2402 push_space -= btrfs_item_size(right, item);
2403 btrfs_set_item_offset(right, item, push_space);
2404 }
2405
2406 if (right->map_token) {
2407 unmap_extent_buffer(right, right->map_token, KM_USER1);
2408 right->map_token = NULL;
00ec4c51 2409 }
7518a238 2410 left_nritems -= push_items;
5f39d397 2411 btrfs_set_header_nritems(left, left_nritems);
00ec4c51 2412
34a38218
CM		 2413 if (left_nritems)
2414 btrfs_mark_buffer_dirty(left);
5f39d397 2415 btrfs_mark_buffer_dirty(right);
a429e513 2416
5f39d397
CM		 2417 btrfs_item_key(right, &disk_key, 0);
2418 btrfs_set_node_key(upper, &disk_key, slot + 1);
d6025579 2419 btrfs_mark_buffer_dirty(upper);
02217ed2 2420
00ec4c51 2421 /* then fixup the leaf pointer in the path */
7518a238
CM		 2422 if (path->slots[0] >= left_nritems) {
2423 path->slots[0] -= left_nritems;
925baedd
CM		 2424 if (btrfs_header_nritems(path->nodes[0]) == 0)
2425 clean_tree_block(trans, root, path->nodes[0]);
2426 btrfs_tree_unlock(path->nodes[0]);
5f39d397
CM		 2427 free_extent_buffer(path->nodes[0]);
2428 path->nodes[0] = right;
00ec4c51
CM		 2429 path->slots[1] += 1;
2430 } else {
925baedd 2431 btrfs_tree_unlock(right);
5f39d397 2432 free_extent_buffer(right);
00ec4c51
CM		 2433 }
2434 return 0;
925baedd
CM		 2435
2436out_unlock:
2437 btrfs_tree_unlock(right);
2438 free_extent_buffer(right);
2439 return 1;
00ec4c51 2440}
925baedd 2441
44871b1b
CM		 2442/*
2443 * push some data in the path leaf to the right, trying to free up at
2444 * least data_size bytes. returns zero if the push worked, nonzero otherwise
2445 *
2446 * returns 1 if the push failed because the other node didn't have enough
2447 * room, 0 if everything worked out and < 0 if there were major errors.
2448 */
2449static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
2450 *root, struct btrfs_path *path, int data_size,
2451 int empty)
2452{
2453 struct extent_buffer *left = path->nodes[0];
2454 struct extent_buffer *right;
2455 struct extent_buffer *upper;
2456 int slot;
2457 int free_space;
2458 u32 left_nritems;
2459 int ret;
2460
2461 if (!path->nodes[1])
2462 return 1;
2463
2464 slot = path->slots[1];
2465 upper = path->nodes[1];
2466 if (slot >= btrfs_header_nritems(upper) - 1)
2467 return 1;
2468
2469 btrfs_assert_tree_locked(path->nodes[1]);
2470
2471 right = read_node_slot(root, upper, slot + 1);
2472 btrfs_tree_lock(right);
2473 btrfs_set_lock_blocking(right);
2474
2475 free_space = btrfs_leaf_free_space(root, right);
2476 if (free_space < data_size)
2477 goto out_unlock;
2478
2479 /* cow and double check */
2480 ret = btrfs_cow_block(trans, root, right, upper,
2481 slot + 1, &right);
2482 if (ret)
2483 goto out_unlock;
2484
2485 free_space = btrfs_leaf_free_space(root, right);
2486 if (free_space < data_size)
2487 goto out_unlock;
2488
2489 left_nritems = btrfs_header_nritems(left);
2490 if (left_nritems == 0)
2491 goto out_unlock;
2492
2493 return __push_leaf_right(trans, root, path, data_size, empty,
2494 right, free_space, left_nritems);
2495out_unlock:
2496 btrfs_tree_unlock(right);
2497 free_extent_buffer(right);
2498 return 1;
2499}
2500
74123bd7
CM		 2501/*
2502 * push some data in the path leaf to the left, trying to free up at
2503 * least data_size bytes. returns zero if the push worked, nonzero otherwise
2504 */
44871b1b
CM		 2505static noinline int __push_leaf_left(struct btrfs_trans_handle *trans,
2506 struct btrfs_root *root,
2507 struct btrfs_path *path, int data_size,
2508 int empty, struct extent_buffer *left,
2509 int free_space, int right_nritems)
be0e5c09 2510{
5f39d397
CM		 2511 struct btrfs_disk_key disk_key;
2512 struct extent_buffer *right = path->nodes[0];
be0e5c09
CM		 2513 int slot;
2514 int i;
be0e5c09
CM		 2515 int push_space = 0;
2516 int push_items = 0;
0783fcfc 2517 struct btrfs_item *item;
7518a238 2518 u32 old_left_nritems;
34a38218 2519 u32 nr;
aa5d6bed
CM		 2520 int ret = 0;
2521 int wret;
db94535d
CM		 2522 u32 this_item_size;
2523 u32 old_left_item_size;
be0e5c09
CM		 2524
2525 slot = path->slots[1];
02217ed2 2526
34a38218
CM		 2527 if (empty)
2528 nr = right_nritems;
2529 else
2530 nr = right_nritems - 1;
2531
2532 for (i = 0; i < nr; i++) {
5f39d397 2533 item = btrfs_item_nr(right, i);
db94535d
CM		 2534 if (!right->map_token) {
2535 map_extent_buffer(right, (unsigned long)item,
2536 sizeof(struct btrfs_item),
2537 &right->map_token, &right->kaddr,
2538 &right->map_start, &right->map_len,
2539 KM_USER1);
2540 }
2541
31840ae1
ZY		 2542 if (!empty && push_items > 0) {
2543 if (path->slots[0] < i)
2544 break;
2545 if (path->slots[0] == i) {
2546 int space = btrfs_leaf_free_space(root, right);
2547 if (space + push_space * 2 > free_space)
2548 break;
2549 }
2550 }
2551
be0e5c09 2552 if (path->slots[0] == i)
87b29b20 2553 push_space += data_size;
db94535d
CM		 2554
2555 this_item_size = btrfs_item_size(right, item);
2556 if (this_item_size + sizeof(*item) + push_space > free_space)
be0e5c09 2557 break;
db94535d 2558
be0e5c09 2559 push_items++;
db94535d
CM		 2560 push_space += this_item_size + sizeof(*item);
2561 }
2562
2563 if (right->map_token) {
2564 unmap_extent_buffer(right, right->map_token, KM_USER1);
2565 right->map_token = NULL;
be0e5c09 2566 }
db94535d 2567
be0e5c09 2568 if (push_items == 0) {
925baedd
CM		 2569 ret = 1;
2570 goto out;
be0e5c09 2571 }
34a38218 2572 if (!empty && push_items == btrfs_header_nritems(right))
a429e513 2573 WARN_ON(1);
5f39d397 2574
be0e5c09 2575 /* push data from right to left */
5f39d397
CM		 2576 copy_extent_buffer(left, right,
2577 btrfs_item_nr_offset(btrfs_header_nritems(left)),
2578 btrfs_item_nr_offset(0),
2579 push_items * sizeof(struct btrfs_item));
2580
123abc88 2581 push_space = BTRFS_LEAF_DATA_SIZE(root) -
d397712b 2582 btrfs_item_offset_nr(right, push_items - 1);
5f39d397
CM		 2583
2584 copy_extent_buffer(left, right, btrfs_leaf_data(left) +
d6025579
CM		 2585 leaf_data_end(root, left) - push_space,
2586 btrfs_leaf_data(right) +
5f39d397 2587 btrfs_item_offset_nr(right, push_items - 1),
d6025579 2588 push_space);
5f39d397 2589 old_left_nritems = btrfs_header_nritems(left);
87b29b20 2590 BUG_ON(old_left_nritems <= 0);
eb60ceac 2591
db94535d 2592 old_left_item_size = btrfs_item_offset_nr(left, old_left_nritems - 1);
0783fcfc 2593 for (i = old_left_nritems; i < old_left_nritems + push_items; i++) {
5f39d397 2594 u32 ioff;
db94535d 2595
5f39d397 2596 item = btrfs_item_nr(left, i);
db94535d
CM		 2597 if (!left->map_token) {
2598 map_extent_buffer(left, (unsigned long)item,
2599 sizeof(struct btrfs_item),
2600 &left->map_token, &left->kaddr,
2601 &left->map_start, &left->map_len,
2602 KM_USER1);
2603 }
2604
5f39d397
CM		 2605 ioff = btrfs_item_offset(left, item);
2606 btrfs_set_item_offset(left, item,
db94535d 2607 ioff - (BTRFS_LEAF_DATA_SIZE(root) - old_left_item_size));
be0e5c09 2608 }
5f39d397 2609 btrfs_set_header_nritems(left, old_left_nritems + push_items);
db94535d
CM		 2610 if (left->map_token) {
2611 unmap_extent_buffer(left, left->map_token, KM_USER1);
2612 left->map_token = NULL;
2613 }
be0e5c09
CM		 2614
2615 /* fixup right node */
34a38218 2616 if (push_items > right_nritems) {
d397712b
CM		 2617 printk(KERN_CRIT "push items %d nr %u\n", push_items,
2618 right_nritems);
34a38218
CM		 2619 WARN_ON(1);
2620 }
2621
2622 if (push_items < right_nritems) {
2623 push_space = btrfs_item_offset_nr(right, push_items - 1) -
2624 leaf_data_end(root, right);
2625 memmove_extent_buffer(right, btrfs_leaf_data(right) +
2626 BTRFS_LEAF_DATA_SIZE(root) - push_space,
2627 btrfs_leaf_data(right) +
2628 leaf_data_end(root, right), push_space);
2629
2630 memmove_extent_buffer(right, btrfs_item_nr_offset(0),
5f39d397
CM		 2631 btrfs_item_nr_offset(push_items),
2632 (btrfs_header_nritems(right) - push_items) *
2633 sizeof(struct btrfs_item));
34a38218 2634 }
eef1c494
Y		 2635 right_nritems -= push_items;
2636 btrfs_set_header_nritems(right, right_nritems);
123abc88 2637 push_space = BTRFS_LEAF_DATA_SIZE(root);
5f39d397
CM		 2638 for (i = 0; i < right_nritems; i++) {
2639 item = btrfs_item_nr(right, i);
db94535d
CM		 2640
2641 if (!right->map_token) {
2642 map_extent_buffer(right, (unsigned long)item,
2643 sizeof(struct btrfs_item),
2644 &right->map_token, &right->kaddr,
2645 &right->map_start, &right->map_len,
2646 KM_USER1);
2647 }
2648
2649 push_space = push_space - btrfs_item_size(right, item);
2650 btrfs_set_item_offset(right, item, push_space);
2651 }
2652 if (right->map_token) {
2653 unmap_extent_buffer(right, right->map_token, KM_USER1);
2654 right->map_token = NULL;
be0e5c09 2655 }
eb60ceac 2656
5f39d397 2657 btrfs_mark_buffer_dirty(left);
34a38218
CM		 2658 if (right_nritems)
2659 btrfs_mark_buffer_dirty(right);
098f59c2 2660
5f39d397
CM		 2661 btrfs_item_key(right, &disk_key, 0);
2662 wret = fixup_low_keys(trans, root, path, &disk_key, 1);
aa5d6bed
CM		 2663 if (wret)
2664 ret = wret;
be0e5c09
CM		 2665
2666 /* then fixup the leaf pointer in the path */
2667 if (path->slots[0] < push_items) {
2668 path->slots[0] += old_left_nritems;
925baedd
CM		 2669 if (btrfs_header_nritems(path->nodes[0]) == 0)
2670 clean_tree_block(trans, root, path->nodes[0]);
2671 btrfs_tree_unlock(path->nodes[0]);
5f39d397
CM		 2672 free_extent_buffer(path->nodes[0]);
2673 path->nodes[0] = left;
be0e5c09
CM		 2674 path->slots[1] -= 1;
2675 } else {
925baedd 2676 btrfs_tree_unlock(left);
5f39d397 2677 free_extent_buffer(left);
be0e5c09
CM		 2678 path->slots[0] -= push_items;
2679 }
eb60ceac 2680 BUG_ON(path->slots[0] < 0);
aa5d6bed 2681 return ret;
925baedd
CM		 2682out:
2683 btrfs_tree_unlock(left);
2684 free_extent_buffer(left);
2685 return ret;
be0e5c09
CM		 2686}
2687
44871b1b
CM		 2688/*
2689 * push some data in the path leaf to the left, trying to free up at
2690 * least data_size bytes. returns zero if the push worked, nonzero otherwise
2691 */
2692static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
2693 *root, struct btrfs_path *path, int data_size,
2694 int empty)
2695{
2696 struct extent_buffer *right = path->nodes[0];
2697 struct extent_buffer *left;
2698 int slot;
2699 int free_space;
2700 u32 right_nritems;
2701 int ret = 0;
2702
2703 slot = path->slots[1];
2704 if (slot == 0)
2705 return 1;
2706 if (!path->nodes[1])
2707 return 1;
2708
2709 right_nritems = btrfs_header_nritems(right);
2710 if (right_nritems == 0)
2711 return 1;
2712
2713 btrfs_assert_tree_locked(path->nodes[1]);
2714
2715 left = read_node_slot(root, path->nodes[1], slot - 1);
2716 btrfs_tree_lock(left);
2717 btrfs_set_lock_blocking(left);
2718
2719 free_space = btrfs_leaf_free_space(root, left);
2720 if (free_space < data_size) {
2721 ret = 1;
2722 goto out;
2723 }
2724
2725 /* cow and double check */
2726 ret = btrfs_cow_block(trans, root, left,
2727 path->nodes[1], slot - 1, &left);
2728 if (ret) {
2729 /* we hit -ENOSPC, but it isn't fatal here */
2730 ret = 1;
2731 goto out;
2732 }
2733
2734 free_space = btrfs_leaf_free_space(root, left);
2735 if (free_space < data_size) {
2736 ret = 1;
2737 goto out;
2738 }
2739
2740 return __push_leaf_left(trans, root, path, data_size,
2741 empty, left, free_space, right_nritems);
2742out:
2743 btrfs_tree_unlock(left);
2744 free_extent_buffer(left);
2745 return ret;
2746}
2747
2748/*
2749 * split the path's leaf in two, making sure there is at least data_size
2750 * available for the resulting leaf level of the path.
2751 *
2752 * returns 0 if all went well and < 0 on failure.
2753 */
2754static noinline int copy_for_split(struct btrfs_trans_handle *trans,
2755 struct btrfs_root *root,
2756 struct btrfs_path *path,
2757 struct extent_buffer *l,
2758 struct extent_buffer *right,
2759 int slot, int mid, int nritems)
2760{
2761 int data_copy_size;
2762 int rt_data_off;
2763 int i;
2764 int ret = 0;
2765 int wret;
2766 struct btrfs_disk_key disk_key;
2767
2768 nritems = nritems - mid;
2769 btrfs_set_header_nritems(right, nritems);
2770 data_copy_size = btrfs_item_end_nr(l, mid) - leaf_data_end(root, l);
2771
2772 copy_extent_buffer(right, l, btrfs_item_nr_offset(0),
2773 btrfs_item_nr_offset(mid),
2774 nritems * sizeof(struct btrfs_item));
2775
2776 copy_extent_buffer(right, l,
2777 btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) -
2778 data_copy_size, btrfs_leaf_data(l) +
2779 leaf_data_end(root, l), data_copy_size);
2780
2781 rt_data_off = BTRFS_LEAF_DATA_SIZE(root) -
2782 btrfs_item_end_nr(l, mid);
2783
2784 for (i = 0; i < nritems; i++) {
2785 struct btrfs_item *item = btrfs_item_nr(right, i);
2786 u32 ioff;
2787
2788 if (!right->map_token) {
2789 map_extent_buffer(right, (unsigned long)item,
2790 sizeof(struct btrfs_item),
2791 &right->map_token, &right->kaddr,
2792 &right->map_start, &right->map_len,
2793 KM_USER1);
2794 }
2795
2796 ioff = btrfs_item_offset(right, item);
2797 btrfs_set_item_offset(right, item, ioff + rt_data_off);
2798 }
2799
2800 if (right->map_token) {
2801 unmap_extent_buffer(right, right->map_token, KM_USER1);
2802 right->map_token = NULL;
2803 }
2804
2805 btrfs_set_header_nritems(l, mid);
2806 ret = 0;
2807 btrfs_item_key(right, &disk_key, 0);
2808 wret = insert_ptr(trans, root, path, &disk_key, right->start,
2809 path->slots[1] + 1, 1);
2810 if (wret)
2811 ret = wret;
2812
2813 btrfs_mark_buffer_dirty(right);
2814 btrfs_mark_buffer_dirty(l);
2815 BUG_ON(path->slots[0] != slot);
2816
44871b1b
CM		 2817 if (mid <= slot) {
2818 btrfs_tree_unlock(path->nodes[0]);
2819 free_extent_buffer(path->nodes[0]);
2820 path->nodes[0] = right;
2821 path->slots[0] -= mid;
2822 path->slots[1] += 1;
2823 } else {
2824 btrfs_tree_unlock(right);
2825 free_extent_buffer(right);
2826 }
2827
2828 BUG_ON(path->slots[0] < 0);
2829
2830 return ret;
2831}
2832
74123bd7
CM		 2833/*
2834 * split the path's leaf in two, making sure there is at least data_size
2835 * available for the resulting leaf level of the path.
aa5d6bed
CM		 2836 *
2837 * returns 0 if all went well and < 0 on failure.
74123bd7 2838 */
e02119d5
CM		 2839static noinline int split_leaf(struct btrfs_trans_handle *trans,
2840 struct btrfs_root *root,
2841 struct btrfs_key *ins_key,
2842 struct btrfs_path *path, int data_size,
2843 int extend)
be0e5c09 2844{
5d4f98a2 2845 struct btrfs_disk_key disk_key;
5f39d397 2846 struct extent_buffer *l;
7518a238 2847 u32 nritems;
eb60ceac
CM		 2848 int mid;
2849 int slot;
5f39d397 2850 struct extent_buffer *right;
d4dbff95 2851 int ret = 0;
aa5d6bed 2852 int wret;
5d4f98a2 2853 int split;
cc0c5538 2854 int num_doubles = 0;
aa5d6bed 2855
40689478 2856 /* first try to make some room by pushing left and right */
b3612421 2857 if (data_size && ins_key->type != BTRFS_DIR_ITEM_KEY) {
34a38218 2858 wret = push_leaf_right(trans, root, path, data_size, 0);
d397712b 2859 if (wret < 0)
eaee50e8 2860 return wret;
3685f791 2861 if (wret) {
34a38218 2862 wret = push_leaf_left(trans, root, path, data_size, 0);
3685f791
CM		 2863 if (wret < 0)
2864 return wret;
2865 }
2866 l = path->nodes[0];
aa5d6bed 2867
3685f791 2868 /* did the pushes work? */
87b29b20 2869 if (btrfs_leaf_free_space(root, l) >= data_size)
3685f791 2870 return 0;
3326d1b0 2871 }
aa5d6bed 2872
5c680ed6 2873 if (!path->nodes[1]) {
e089f05c 2874 ret = insert_new_root(trans, root, path, 1);
5c680ed6
CM		 2875 if (ret)
2876 return ret;
2877 }
cc0c5538 2878again:
5d4f98a2 2879 split = 1;
cc0c5538 2880 l = path->nodes[0];
eb60ceac 2881 slot = path->slots[0];
5f39d397 2882 nritems = btrfs_header_nritems(l);
d397712b 2883 mid = (nritems + 1) / 2;
54aa1f4d 2884
5d4f98a2
YZ		 2885 if (mid <= slot) {
2886 if (nritems == 1 ||
2887 leaf_space_used(l, mid, nritems - mid) + data_size >
2888 BTRFS_LEAF_DATA_SIZE(root)) {
2889 if (slot >= nritems) {
2890 split = 0;
2891 } else {
2892 mid = slot;
2893 if (mid != nritems &&
2894 leaf_space_used(l, mid, nritems - mid) +
2895 data_size > BTRFS_LEAF_DATA_SIZE(root)) {
2896 split = 2;
2897 }
2898 }
2899 }
2900 } else {
2901 if (leaf_space_used(l, 0, mid) + data_size >
2902 BTRFS_LEAF_DATA_SIZE(root)) {
2903 if (!extend && data_size && slot == 0) {
2904 split = 0;
2905 } else if ((extend || !data_size) && slot == 0) {
2906 mid = 1;
2907 } else {
2908 mid = slot;
2909 if (mid != nritems &&
2910 leaf_space_used(l, mid, nritems - mid) +
2911 data_size > BTRFS_LEAF_DATA_SIZE(root)) {
2912 split = 2 ;
2913 }
2914 }
2915 }
2916 }
2917
2918 if (split == 0)
2919 btrfs_cpu_key_to_disk(&disk_key, ins_key);
2920 else
2921 btrfs_item_key(l, &disk_key, mid);
2922
2923 right = btrfs_alloc_free_block(trans, root, root->leafsize, 0,
31840ae1 2924 root->root_key.objectid,
5d4f98a2 2925 &disk_key, 0, l->start, 0);
cea9e445
CM		 2926 if (IS_ERR(right)) {
2927 BUG_ON(1);
5f39d397 2928 return PTR_ERR(right);
cea9e445 2929 }
5f39d397
CM		 2930
2931 memset_extent_buffer(right, 0, 0, sizeof(struct btrfs_header));
db94535d 2932 btrfs_set_header_bytenr(right, right->start);
5f39d397 2933 btrfs_set_header_generation(right, trans->transid);
5d4f98a2 2934 btrfs_set_header_backref_rev(right, BTRFS_MIXED_BACKREF_REV);
5f39d397
CM		 2935 btrfs_set_header_owner(right, root->root_key.objectid);
2936 btrfs_set_header_level(right, 0);
2937 write_extent_buffer(right, root->fs_info->fsid,
2938 (unsigned long)btrfs_header_fsid(right),
2939 BTRFS_FSID_SIZE);
e17cade2
CM		 2940
2941 write_extent_buffer(right, root->fs_info->chunk_tree_uuid,
2942 (unsigned long)btrfs_header_chunk_tree_uuid(right),
2943 BTRFS_UUID_SIZE);
44871b1b 2944
5d4f98a2
YZ		 2945 if (split == 0) {
2946 if (mid <= slot) {
2947 btrfs_set_header_nritems(right, 0);
2948 wret = insert_ptr(trans, root, path,
2949 &disk_key, right->start,
2950 path->slots[1] + 1, 1);
2951 if (wret)
2952 ret = wret;
925baedd 2953
5d4f98a2
YZ		 2954 btrfs_tree_unlock(path->nodes[0]);
2955 free_extent_buffer(path->nodes[0]);
2956 path->nodes[0] = right;
2957 path->slots[0] = 0;
2958 path->slots[1] += 1;
2959 } else {
2960 btrfs_set_header_nritems(right, 0);
2961 wret = insert_ptr(trans, root, path,
2962 &disk_key,
2963 right->start,
2964 path->slots[1], 1);
2965 if (wret)
2966 ret = wret;
2967 btrfs_tree_unlock(path->nodes[0]);
2968 free_extent_buffer(path->nodes[0]);
2969 path->nodes[0] = right;
2970 path->slots[0] = 0;
2971 if (path->slots[1] == 0) {
2972 wret = fixup_low_keys(trans, root,
2973 path, &disk_key, 1);
d4dbff95
CM		 2974 if (wret)
2975 ret = wret;
5ee78ac7 2976 }
d4dbff95 2977 }
5d4f98a2
YZ		 2978 btrfs_mark_buffer_dirty(right);
2979 return ret;
d4dbff95 2980 }
74123bd7 2981
44871b1b 2982 ret = copy_for_split(trans, root, path, l, right, slot, mid, nritems);
31840ae1
ZY		 2983 BUG_ON(ret);
2984
5d4f98a2 2985 if (split == 2) {
cc0c5538
CM		 2986 BUG_ON(num_doubles != 0);
2987 num_doubles++;
2988 goto again;
a429e513 2989 }
44871b1b 2990
be0e5c09
CM		 2991 return ret;
2992}
2993
459931ec
CM		 2994/*
2995 * This function splits a single item into two items,
2996 * giving 'new_key' to the new item and splitting the
2997 * old one at split_offset (from the start of the item).
2998 *
2999 * The path may be released by this operation. After
3000 * the split, the path is pointing to the old item. The
3001 * new item is going to be in the same node as the old one.
3002 *
3003 * Note, the item being split must be smaller enough to live alone on
3004 * a tree block with room for one extra struct btrfs_item
3005 *
3006 * This allows us to split the item in place, keeping a lock on the
3007 * leaf the entire time.
3008 */
3009int btrfs_split_item(struct btrfs_trans_handle *trans,
3010 struct btrfs_root *root,
3011 struct btrfs_path *path,
3012 struct btrfs_key *new_key,
3013 unsigned long split_offset)
3014{
3015 u32 item_size;
3016 struct extent_buffer *leaf;
3017 struct btrfs_key orig_key;
3018 struct btrfs_item *item;
3019 struct btrfs_item *new_item;
3020 int ret = 0;
3021 int slot;
3022 u32 nritems;
3023 u32 orig_offset;
3024 struct btrfs_disk_key disk_key;
3025 char *buf;
3026
3027 leaf = path->nodes[0];
3028 btrfs_item_key_to_cpu(leaf, &orig_key, path->slots[0]);
3029 if (btrfs_leaf_free_space(root, leaf) >= sizeof(struct btrfs_item))
3030 goto split;
3031
3032 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
3033 btrfs_release_path(root, path);
3034
3035 path->search_for_split = 1;
3036 path->keep_locks = 1;
3037
3038 ret = btrfs_search_slot(trans, root, &orig_key, path, 0, 1);
3039 path->search_for_split = 0;
3040
3041 /* if our item isn't there or got smaller, return now */
3042 if (ret != 0 || item_size != btrfs_item_size_nr(path->nodes[0],
3043 path->slots[0])) {
3044 path->keep_locks = 0;
3045 return -EAGAIN;
3046 }
3047
b9473439 3048 btrfs_set_path_blocking(path);
87b29b20
YZ		 3049 ret = split_leaf(trans, root, &orig_key, path,
3050 sizeof(struct btrfs_item), 1);
459931ec
CM		 3051 path->keep_locks = 0;
3052 BUG_ON(ret);
3053
b9473439
CM		 3054 btrfs_unlock_up_safe(path, 1);
3055 leaf = path->nodes[0];
3056 BUG_ON(btrfs_leaf_free_space(root, leaf) < sizeof(struct btrfs_item));
3057
3058split:
b4ce94de
CM		 3059 /*
3060 * make sure any changes to the path from split_leaf leave it
3061 * in a blocking state
3062 */
3063 btrfs_set_path_blocking(path);
3064
459931ec
CM		 3065 item = btrfs_item_nr(leaf, path->slots[0]);
3066 orig_offset = btrfs_item_offset(leaf, item);
3067 item_size = btrfs_item_size(leaf, item);
3068
459931ec
CM		 3069 buf = kmalloc(item_size, GFP_NOFS);
3070 read_extent_buffer(leaf, buf, btrfs_item_ptr_offset(leaf,
3071 path->slots[0]), item_size);
3072 slot = path->slots[0] + 1;
3073 leaf = path->nodes[0];
3074
3075 nritems = btrfs_header_nritems(leaf);
3076
3077 if (slot != nritems) {
3078 /* shift the items */
3079 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + 1),
3080 btrfs_item_nr_offset(slot),
3081 (nritems - slot) * sizeof(struct btrfs_item));
3082
3083 }
3084
3085 btrfs_cpu_key_to_disk(&disk_key, new_key);
3086 btrfs_set_item_key(leaf, &disk_key, slot);
3087
3088 new_item = btrfs_item_nr(leaf, slot);
3089
3090 btrfs_set_item_offset(leaf, new_item, orig_offset);
3091 btrfs_set_item_size(leaf, new_item, item_size - split_offset);
3092
3093 btrfs_set_item_offset(leaf, item,
3094 orig_offset + item_size - split_offset);
3095 btrfs_set_item_size(leaf, item, split_offset);
3096
3097 btrfs_set_header_nritems(leaf, nritems + 1);
3098
3099 /* write the data for the start of the original item */
3100 write_extent_buffer(leaf, buf,
3101 btrfs_item_ptr_offset(leaf, path->slots[0]),
3102 split_offset);
3103
3104 /* write the data for the new item */
3105 write_extent_buffer(leaf, buf + split_offset,
3106 btrfs_item_ptr_offset(leaf, slot),
3107 item_size - split_offset);
3108 btrfs_mark_buffer_dirty(leaf);
3109
3110 ret = 0;
3111 if (btrfs_leaf_free_space(root, leaf) < 0) {
3112 btrfs_print_leaf(root, leaf);
3113 BUG();
3114 }
3115 kfree(buf);
3116 return ret;
3117}
3118
d352ac68
CM		 3119/*
3120 * make the item pointed to by the path smaller. new_size indicates
3121 * how small to make it, and from_end tells us if we just chop bytes
3122 * off the end of the item or if we shift the item to chop bytes off
3123 * the front.
3124 */
b18c6685
CM		 3125int btrfs_truncate_item(struct btrfs_trans_handle *trans,
3126 struct btrfs_root *root,
3127 struct btrfs_path *path,
179e29e4 3128 u32 new_size, int from_end)
b18c6685
CM		 3129{
3130 int ret = 0;
3131 int slot;
3132 int slot_orig;
5f39d397
CM		 3133 struct extent_buffer *leaf;
3134 struct btrfs_item *item;
b18c6685
CM		 3135 u32 nritems;
3136 unsigned int data_end;
3137 unsigned int old_data_start;
3138 unsigned int old_size;
3139 unsigned int size_diff;
3140 int i;
3141
3142 slot_orig = path->slots[0];
5f39d397 3143 leaf = path->nodes[0];
179e29e4
CM		 3144 slot = path->slots[0];
3145
3146 old_size = btrfs_item_size_nr(leaf, slot);
3147 if (old_size == new_size)
3148 return 0;
b18c6685 3149
5f39d397 3150 nritems = btrfs_header_nritems(leaf);
b18c6685
CM		 3151 data_end = leaf_data_end(root, leaf);
3152
5f39d397 3153 old_data_start = btrfs_item_offset_nr(leaf, slot);
179e29e4 3154
b18c6685
CM		 3155 size_diff = old_size - new_size;
3156
3157 BUG_ON(slot < 0);
3158 BUG_ON(slot >= nritems);
3159
3160 /*
3161 * item0..itemN ... dataN.offset..dataN.size .. data0.size
3162 */
3163 /* first correct the data pointers */
3164 for (i = slot; i < nritems; i++) {
5f39d397
CM		 3165 u32 ioff;
3166 item = btrfs_item_nr(leaf, i);
db94535d
CM		 3167
3168 if (!leaf->map_token) {
3169 map_extent_buffer(leaf, (unsigned long)item,
3170 sizeof(struct btrfs_item),
3171 &leaf->map_token, &leaf->kaddr,
3172 &leaf->map_start, &leaf->map_len,
3173 KM_USER1);
3174 }
3175
5f39d397
CM		 3176 ioff = btrfs_item_offset(leaf, item);
3177 btrfs_set_item_offset(leaf, item, ioff + size_diff);
b18c6685 3178 }
db94535d
CM		 3179
3180 if (leaf->map_token) {
3181 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
3182 leaf->map_token = NULL;
3183 }
3184
b18c6685 3185 /* shift the data */
179e29e4
CM		 3186 if (from_end) {
3187 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
3188 data_end + size_diff, btrfs_leaf_data(leaf) +
3189 data_end, old_data_start + new_size - data_end);
3190 } else {
3191 struct btrfs_disk_key disk_key;
3192 u64 offset;
3193
3194 btrfs_item_key(leaf, &disk_key, slot);
3195
3196 if (btrfs_disk_key_type(&disk_key) == BTRFS_EXTENT_DATA_KEY) {
3197 unsigned long ptr;
3198 struct btrfs_file_extent_item *fi;
3199
3200 fi = btrfs_item_ptr(leaf, slot,
3201 struct btrfs_file_extent_item);
3202 fi = (struct btrfs_file_extent_item *)(
3203 (unsigned long)fi - size_diff);
3204
3205 if (btrfs_file_extent_type(leaf, fi) ==
3206 BTRFS_FILE_EXTENT_INLINE) {
3207 ptr = btrfs_item_ptr_offset(leaf, slot);
3208 memmove_extent_buffer(leaf, ptr,
d397712b
CM		 3209 (unsigned long)fi,
3210 offsetof(struct btrfs_file_extent_item,
179e29e4
CM		 3211 disk_bytenr));
3212 }
3213 }
3214
3215 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
3216 data_end + size_diff, btrfs_leaf_data(leaf) +
3217 data_end, old_data_start - data_end);
3218
3219 offset = btrfs_disk_key_offset(&disk_key);
3220 btrfs_set_disk_key_offset(&disk_key, offset + size_diff);
3221 btrfs_set_item_key(leaf, &disk_key, slot);
3222 if (slot == 0)
3223 fixup_low_keys(trans, root, path, &disk_key, 1);
3224 }
5f39d397
CM		 3225
3226 item = btrfs_item_nr(leaf, slot);
3227 btrfs_set_item_size(leaf, item, new_size);
3228 btrfs_mark_buffer_dirty(leaf);
b18c6685
CM		 3229
3230 ret = 0;
5f39d397
CM		 3231 if (btrfs_leaf_free_space(root, leaf) < 0) {
3232 btrfs_print_leaf(root, leaf);
b18c6685 3233 BUG();
5f39d397 3234 }
b18c6685
CM		 3235 return ret;
3236}
3237
d352ac68
CM		 3238/*
3239 * make the item pointed to by the path bigger, data_size is the new size.
3240 */
5f39d397
CM		 3241int btrfs_extend_item(struct btrfs_trans_handle *trans,
3242 struct btrfs_root *root, struct btrfs_path *path,
3243 u32 data_size)
6567e837
CM		 3244{
3245 int ret = 0;
3246 int slot;
3247 int slot_orig;
5f39d397
CM		 3248 struct extent_buffer *leaf;
3249 struct btrfs_item *item;
6567e837
CM		 3250 u32 nritems;
3251 unsigned int data_end;
3252 unsigned int old_data;
3253 unsigned int old_size;
3254 int i;
3255
3256 slot_orig = path->slots[0];
5f39d397 3257 leaf = path->nodes[0];
6567e837 3258
5f39d397 3259 nritems = btrfs_header_nritems(leaf);
6567e837
CM		 3260 data_end = leaf_data_end(root, leaf);
3261
5f39d397
CM		 3262 if (btrfs_leaf_free_space(root, leaf) < data_size) {
3263 btrfs_print_leaf(root, leaf);
6567e837 3264 BUG();
5f39d397 3265 }
6567e837 3266 slot = path->slots[0];
5f39d397 3267 old_data = btrfs_item_end_nr(leaf, slot);
6567e837
CM		 3268
3269 BUG_ON(slot < 0);
3326d1b0
CM		 3270 if (slot >= nritems) {
3271 btrfs_print_leaf(root, leaf);
d397712b
CM		 3272 printk(KERN_CRIT "slot %d too large, nritems %d\n",
3273 slot, nritems);
3326d1b0
CM		 3274 BUG_ON(1);
3275 }
6567e837
CM		 3276
3277 /*
3278 * item0..itemN ... dataN.offset..dataN.size .. data0.size
3279 */
3280 /* first correct the data pointers */
3281 for (i = slot; i < nritems; i++) {
5f39d397
CM		 3282 u32 ioff;
3283 item = btrfs_item_nr(leaf, i);
db94535d
CM		 3284
3285 if (!leaf->map_token) {
3286 map_extent_buffer(leaf, (unsigned long)item,
3287 sizeof(struct btrfs_item),
3288 &leaf->map_token, &leaf->kaddr,
3289 &leaf->map_start, &leaf->map_len,
3290 KM_USER1);
3291 }
5f39d397
CM		 3292 ioff = btrfs_item_offset(leaf, item);
3293 btrfs_set_item_offset(leaf, item, ioff - data_size);
6567e837 3294 }
5f39d397 3295
db94535d
CM		 3296 if (leaf->map_token) {
3297 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
3298 leaf->map_token = NULL;
3299 }
3300
6567e837 3301 /* shift the data */
5f39d397 3302 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
6567e837
CM		 3303 data_end - data_size, btrfs_leaf_data(leaf) +
3304 data_end, old_data - data_end);
5f39d397 3305
6567e837 3306 data_end = old_data;
5f39d397
CM		 3307 old_size = btrfs_item_size_nr(leaf, slot);
3308 item = btrfs_item_nr(leaf, slot);
3309 btrfs_set_item_size(leaf, item, old_size + data_size);
3310 btrfs_mark_buffer_dirty(leaf);
6567e837
CM		 3311
3312 ret = 0;
5f39d397
CM		 3313 if (btrfs_leaf_free_space(root, leaf) < 0) {
3314 btrfs_print_leaf(root, leaf);
6567e837 3315 BUG();
5f39d397 3316 }
6567e837
CM		 3317 return ret;
3318}
3319
f3465ca4
JB		 3320/*
3321 * Given a key and some data, insert items into the tree.
3322 * This does all the path init required, making room in the tree if needed.
3323 * Returns the number of keys that were inserted.
3324 */
3325int btrfs_insert_some_items(struct btrfs_trans_handle *trans,
3326 struct btrfs_root *root,
3327 struct btrfs_path *path,
3328 struct btrfs_key *cpu_key, u32 *data_size,
3329 int nr)
3330{
3331 struct extent_buffer *leaf;
3332 struct btrfs_item *item;
3333 int ret = 0;
3334 int slot;
f3465ca4
JB		 3335 int i;
3336 u32 nritems;
3337 u32 total_data = 0;
3338 u32 total_size = 0;
3339 unsigned int data_end;
3340 struct btrfs_disk_key disk_key;
3341 struct btrfs_key found_key;
3342
87b29b20
YZ		 3343 for (i = 0; i < nr; i++) {
3344 if (total_size + data_size[i] + sizeof(struct btrfs_item) >
3345 BTRFS_LEAF_DATA_SIZE(root)) {
3346 break;
3347 nr = i;
3348 }
f3465ca4 3349 total_data += data_size[i];
87b29b20
YZ		 3350 total_size += data_size[i] + sizeof(struct btrfs_item);
3351 }
3352 BUG_ON(nr == 0);
f3465ca4 3353
f3465ca4
JB		 3354 ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1);
3355 if (ret == 0)
3356 return -EEXIST;
3357 if (ret < 0)
3358 goto out;
3359
f3465ca4
JB		 3360 leaf = path->nodes[0];
3361
3362 nritems = btrfs_header_nritems(leaf);
3363 data_end = leaf_data_end(root, leaf);
3364
3365 if (btrfs_leaf_free_space(root, leaf) < total_size) {
3366 for (i = nr; i >= 0; i--) {
3367 total_data -= data_size[i];
3368 total_size -= data_size[i] + sizeof(struct btrfs_item);
3369 if (total_size < btrfs_leaf_free_space(root, leaf))
3370 break;
3371 }
3372 nr = i;
3373 }
3374
3375 slot = path->slots[0];
3376 BUG_ON(slot < 0);
3377
3378 if (slot != nritems) {
3379 unsigned int old_data = btrfs_item_end_nr(leaf, slot);
3380
3381 item = btrfs_item_nr(leaf, slot);
3382 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3383
3384 /* figure out how many keys we can insert in here */
3385 total_data = data_size[0];
3386 for (i = 1; i < nr; i++) {
5d4f98a2 3387 if (btrfs_comp_cpu_keys(&found_key, cpu_key + i) <= 0)
f3465ca4
JB		 3388 break;
3389 total_data += data_size[i];
3390 }
3391 nr = i;
3392
3393 if (old_data < data_end) {
3394 btrfs_print_leaf(root, leaf);
d397712b 3395 printk(KERN_CRIT "slot %d old_data %d data_end %d\n",
f3465ca4
JB		 3396 slot, old_data, data_end);
3397 BUG_ON(1);
3398 }
3399 /*
3400 * item0..itemN ... dataN.offset..dataN.size .. data0.size
3401 */
3402 /* first correct the data pointers */
3403 WARN_ON(leaf->map_token);
3404 for (i = slot; i < nritems; i++) {
3405 u32 ioff;
3406
3407 item = btrfs_item_nr(leaf, i);
3408 if (!leaf->map_token) {
3409 map_extent_buffer(leaf, (unsigned long)item,
3410 sizeof(struct btrfs_item),
3411 &leaf->map_token, &leaf->kaddr,
3412 &leaf->map_start, &leaf->map_len,
3413 KM_USER1);
3414 }
3415
3416 ioff = btrfs_item_offset(leaf, item);
3417 btrfs_set_item_offset(leaf, item, ioff - total_data);
3418 }
3419 if (leaf->map_token) {
3420 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
3421 leaf->map_token = NULL;
3422 }
3423
3424 /* shift the items */
3425 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr),
3426 btrfs_item_nr_offset(slot),
3427 (nritems - slot) * sizeof(struct btrfs_item));
3428
3429 /* shift the data */
3430 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
3431 data_end - total_data, btrfs_leaf_data(leaf) +
3432 data_end, old_data - data_end);
3433 data_end = old_data;
3434 } else {
3435 /*
3436 * this sucks but it has to be done, if we are inserting at
3437 * the end of the leaf only insert 1 of the items, since we
3438 * have no way of knowing whats on the next leaf and we'd have
3439 * to drop our current locks to figure it out
3440 */
3441 nr = 1;
3442 }
3443
3444 /* setup the item for the new data */
3445 for (i = 0; i < nr; i++) {
3446 btrfs_cpu_key_to_disk(&disk_key, cpu_key + i);
3447 btrfs_set_item_key(leaf, &disk_key, slot + i);
3448 item = btrfs_item_nr(leaf, slot + i);
3449 btrfs_set_item_offset(leaf, item, data_end - data_size[i]);
3450 data_end -= data_size[i];
3451 btrfs_set_item_size(leaf, item, data_size[i]);
3452 }
3453 btrfs_set_header_nritems(leaf, nritems + nr);
3454 btrfs_mark_buffer_dirty(leaf);
3455
3456 ret = 0;
3457 if (slot == 0) {
3458 btrfs_cpu_key_to_disk(&disk_key, cpu_key);
3459 ret = fixup_low_keys(trans, root, path, &disk_key, 1);
3460 }
3461
3462 if (btrfs_leaf_free_space(root, leaf) < 0) {
3463 btrfs_print_leaf(root, leaf);
3464 BUG();
3465 }
3466out:
3467 if (!ret)
3468 ret = nr;
3469 return ret;
3470}
3471
74123bd7 3472/*
44871b1b
CM		 3473 * this is a helper for btrfs_insert_empty_items, the main goal here is
3474 * to save stack depth by doing the bulk of the work in a function
3475 * that doesn't call btrfs_search_slot
74123bd7 3476 */
44871b1b
CM		 3477static noinline_for_stack int
3478setup_items_for_insert(struct btrfs_trans_handle *trans,
3479 struct btrfs_root *root, struct btrfs_path *path,
3480 struct btrfs_key *cpu_key, u32 *data_size,
3481 u32 total_data, u32 total_size, int nr)
be0e5c09 3482{
5f39d397 3483 struct btrfs_item *item;
9c58309d 3484 int i;
7518a238 3485 u32 nritems;
be0e5c09 3486 unsigned int data_end;
e2fa7227 3487 struct btrfs_disk_key disk_key;
44871b1b
CM		 3488 int ret;
3489 struct extent_buffer *leaf;
3490 int slot;
e2fa7227 3491
5f39d397 3492 leaf = path->nodes[0];
44871b1b 3493 slot = path->slots[0];
74123bd7 3494
5f39d397 3495 nritems = btrfs_header_nritems(leaf);
123abc88 3496 data_end = leaf_data_end(root, leaf);
eb60ceac 3497
f25956cc 3498 if (btrfs_leaf_free_space(root, leaf) < total_size) {
3326d1b0 3499 btrfs_print_leaf(root, leaf);
d397712b 3500 printk(KERN_CRIT "not enough freespace need %u have %d\n",
9c58309d 3501 total_size, btrfs_leaf_free_space(root, leaf));
be0e5c09 3502 BUG();
d4dbff95 3503 }
5f39d397 3504
be0e5c09 3505 if (slot != nritems) {
5f39d397 3506 unsigned int old_data = btrfs_item_end_nr(leaf, slot);
be0e5c09 3507
5f39d397
CM		 3508 if (old_data < data_end) {
3509 btrfs_print_leaf(root, leaf);
d397712b 3510 printk(KERN_CRIT "slot %d old_data %d data_end %d\n",
5f39d397
CM		 3511 slot, old_data, data_end);
3512 BUG_ON(1);
3513 }
be0e5c09
CM		 3514 /*
3515 * item0..itemN ... dataN.offset..dataN.size .. data0.size
3516 */
3517 /* first correct the data pointers */
db94535d 3518 WARN_ON(leaf->map_token);
0783fcfc 3519 for (i = slot; i < nritems; i++) {
5f39d397 3520 u32 ioff;
db94535d 3521
5f39d397 3522 item = btrfs_item_nr(leaf, i);
db94535d
CM		 3523 if (!leaf->map_token) {
3524 map_extent_buffer(leaf, (unsigned long)item,
3525 sizeof(struct btrfs_item),
3526 &leaf->map_token, &leaf->kaddr,
3527 &leaf->map_start, &leaf->map_len,
3528 KM_USER1);
3529 }
3530
5f39d397 3531 ioff = btrfs_item_offset(leaf, item);
9c58309d 3532 btrfs_set_item_offset(leaf, item, ioff - total_data);
0783fcfc 3533 }
db94535d
CM		 3534 if (leaf->map_token) {
3535 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
3536 leaf->map_token = NULL;
3537 }
be0e5c09
CM		 3538
3539 /* shift the items */
9c58309d 3540 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr),
5f39d397 3541 btrfs_item_nr_offset(slot),
d6025579 3542 (nritems - slot) * sizeof(struct btrfs_item));
be0e5c09
CM		 3543
3544 /* shift the data */
5f39d397 3545 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
9c58309d 3546 data_end - total_data, btrfs_leaf_data(leaf) +
d6025579 3547 data_end, old_data - data_end);
be0e5c09
CM		 3548 data_end = old_data;
3549 }
5f39d397 3550
62e2749e 3551 /* setup the item for the new data */
9c58309d
CM		 3552 for (i = 0; i < nr; i++) {
3553 btrfs_cpu_key_to_disk(&disk_key, cpu_key + i);
3554 btrfs_set_item_key(leaf, &disk_key, slot + i);
3555 item = btrfs_item_nr(leaf, slot + i);
3556 btrfs_set_item_offset(leaf, item, data_end - data_size[i]);
3557 data_end -= data_size[i];
3558 btrfs_set_item_size(leaf, item, data_size[i]);
3559 }
44871b1b 3560
9c58309d 3561 btrfs_set_header_nritems(leaf, nritems + nr);
aa5d6bed
CM		 3562
3563 ret = 0;
5a01a2e3 3564 if (slot == 0) {
44871b1b 3565 struct btrfs_disk_key disk_key;
5a01a2e3 3566 btrfs_cpu_key_to_disk(&disk_key, cpu_key);
e089f05c 3567 ret = fixup_low_keys(trans, root, path, &disk_key, 1);
5a01a2e3 3568 }
b9473439
CM		 3569 btrfs_unlock_up_safe(path, 1);
3570 btrfs_mark_buffer_dirty(leaf);
aa5d6bed 3571
5f39d397
CM		 3572 if (btrfs_leaf_free_space(root, leaf) < 0) {
3573 btrfs_print_leaf(root, leaf);
be0e5c09 3574 BUG();
5f39d397 3575 }
44871b1b
CM		 3576 return ret;
3577}
3578
3579/*
3580 * Given a key and some data, insert items into the tree.
3581 * This does all the path init required, making room in the tree if needed.
3582 */
3583int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
3584 struct btrfs_root *root,
3585 struct btrfs_path *path,
3586 struct btrfs_key *cpu_key, u32 *data_size,
3587 int nr)
3588{
3589 struct extent_buffer *leaf;
3590 int ret = 0;
3591 int slot;
3592 int i;
3593 u32 total_size = 0;
3594 u32 total_data = 0;
3595
3596 for (i = 0; i < nr; i++)
3597 total_data += data_size[i];
3598
3599 total_size = total_data + (nr * sizeof(struct btrfs_item));
3600 ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1);
3601 if (ret == 0)
3602 return -EEXIST;
3603 if (ret < 0)
3604 goto out;
3605
3606 leaf = path->nodes[0];
3607 slot = path->slots[0];
3608 BUG_ON(slot < 0);
3609
3610 ret = setup_items_for_insert(trans, root, path, cpu_key, data_size,
3611 total_data, total_size, nr);
3612
ed2ff2cb 3613out:
62e2749e
CM		 3614 return ret;
3615}
3616
3617/*
3618 * Given a key and some data, insert an item into the tree.
3619 * This does all the path init required, making room in the tree if needed.
3620 */
e089f05c
CM		 3621int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root
3622 *root, struct btrfs_key *cpu_key, void *data, u32
3623 data_size)
62e2749e
CM		 3624{
3625 int ret = 0;
2c90e5d6 3626 struct btrfs_path *path;
5f39d397
CM		 3627 struct extent_buffer *leaf;
3628 unsigned long ptr;
62e2749e 3629
2c90e5d6
CM		 3630 path = btrfs_alloc_path();
3631 BUG_ON(!path);
2c90e5d6 3632 ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size);
62e2749e 3633 if (!ret) {
5f39d397
CM		 3634 leaf = path->nodes[0];
3635 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
3636 write_extent_buffer(leaf, data, ptr, data_size);
3637 btrfs_mark_buffer_dirty(leaf);
62e2749e 3638 }
2c90e5d6 3639 btrfs_free_path(path);
aa5d6bed 3640 return ret;
be0e5c09
CM		 3641}
3642
74123bd7 3643/*
5de08d7d 3644 * delete the pointer from a given node.
74123bd7 3645 *
d352ac68
CM		 3646 * the tree should have been previously balanced so the deletion does not
3647 * empty a node.
74123bd7 3648 */
e089f05c
CM		 3649static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
3650 struct btrfs_path *path, int level, int slot)
be0e5c09 3651{
5f39d397 3652 struct extent_buffer *parent = path->nodes[level];
7518a238 3653 u32 nritems;
aa5d6bed 3654 int ret = 0;
bb803951 3655 int wret;
be0e5c09 3656
5f39d397 3657 nritems = btrfs_header_nritems(parent);
d397712b 3658 if (slot != nritems - 1) {
5f39d397
CM		 3659 memmove_extent_buffer(parent,
3660 btrfs_node_key_ptr_offset(slot),
3661 btrfs_node_key_ptr_offset(slot + 1),
d6025579
CM		 3662 sizeof(struct btrfs_key_ptr) *
3663 (nritems - slot - 1));
bb803951 3664 }
7518a238 3665 nritems--;
5f39d397 3666 btrfs_set_header_nritems(parent, nritems);
7518a238 3667 if (nritems == 0 && parent == root->node) {
5f39d397 3668 BUG_ON(btrfs_header_level(root->node) != 1);
bb803951 3669 /* just turn the root into a leaf and break */
5f39d397 3670 btrfs_set_header_level(root->node, 0);
bb803951 3671 } else if (slot == 0) {
5f39d397
CM		 3672 struct btrfs_disk_key disk_key;
3673
3674 btrfs_node_key(parent, &disk_key, 0);
3675 wret = fixup_low_keys(trans, root, path, &disk_key, level + 1);
0f70abe2
CM		 3676 if (wret)
3677 ret = wret;
be0e5c09 3678 }
d6025579 3679 btrfs_mark_buffer_dirty(parent);
aa5d6bed 3680 return ret;
be0e5c09
CM		 3681}
3682
323ac95b
CM		 3683/*
3684 * a helper function to delete the leaf pointed to by path->slots[1] and
5d4f98a2 3685 * path->nodes[1].
323ac95b
CM		 3686 *
3687 * This deletes the pointer in path->nodes[1] and frees the leaf
3688 * block extent. zero is returned if it all worked out, < 0 otherwise.
3689 *
3690 * The path must have already been setup for deleting the leaf, including
3691 * all the proper balancing. path->nodes[1] must be locked.
3692 */
5d4f98a2
YZ		 3693static noinline int btrfs_del_leaf(struct btrfs_trans_handle *trans,
3694 struct btrfs_root *root,
3695 struct btrfs_path *path,
3696 struct extent_buffer *leaf)
323ac95b
CM		 3697{
3698 int ret;
323ac95b 3699
5d4f98a2 3700 WARN_ON(btrfs_header_generation(leaf) != trans->transid);
323ac95b
CM		 3701 ret = del_ptr(trans, root, path, 1, path->slots[1]);
3702 if (ret)
3703 return ret;
3704
4d081c41
CM		 3705 /*
3706 * btrfs_free_extent is expensive, we want to make sure we
3707 * aren't holding any locks when we call it
3708 */
3709 btrfs_unlock_up_safe(path, 0);
3710
5d4f98a2
YZ		 3711 ret = btrfs_free_extent(trans, root, leaf->start, leaf->len,
3712 0, root->root_key.objectid, 0, 0);
323ac95b
CM		 3713 return ret;
3714}
74123bd7
CM		 3715/*
3716 * delete the item at the leaf level in path. If that empties
3717 * the leaf, remove it from the tree
3718 */
85e21bac
CM		 3719int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
3720 struct btrfs_path *path, int slot, int nr)
be0e5c09 3721{
5f39d397
CM		 3722 struct extent_buffer *leaf;
3723 struct btrfs_item *item;
85e21bac
CM		 3724 int last_off;
3725 int dsize = 0;
aa5d6bed
CM		 3726 int ret = 0;
3727 int wret;
85e21bac 3728 int i;
7518a238 3729 u32 nritems;
be0e5c09 3730
5f39d397 3731 leaf = path->nodes[0];
85e21bac
CM		 3732 last_off = btrfs_item_offset_nr(leaf, slot + nr - 1);
3733
3734 for (i = 0; i < nr; i++)
3735 dsize += btrfs_item_size_nr(leaf, slot + i);
3736
5f39d397 3737 nritems = btrfs_header_nritems(leaf);
be0e5c09 3738
85e21bac 3739 if (slot + nr != nritems) {
123abc88 3740 int data_end = leaf_data_end(root, leaf);
5f39d397
CM		 3741
3742 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
d6025579
CM		 3743 data_end + dsize,
3744 btrfs_leaf_data(leaf) + data_end,
85e21bac 3745 last_off - data_end);
5f39d397 3746
85e21bac 3747 for (i = slot + nr; i < nritems; i++) {
5f39d397 3748 u32 ioff;
db94535d 3749
5f39d397 3750 item = btrfs_item_nr(leaf, i);
db94535d
CM		 3751 if (!leaf->map_token) {
3752 map_extent_buffer(leaf, (unsigned long)item,
3753 sizeof(struct btrfs_item),
3754 &leaf->map_token, &leaf->kaddr,
3755 &leaf->map_start, &leaf->map_len,
3756 KM_USER1);
3757 }
5f39d397
CM		 3758 ioff = btrfs_item_offset(leaf, item);
3759 btrfs_set_item_offset(leaf, item, ioff + dsize);
0783fcfc 3760 }
db94535d
CM		 3761
3762 if (leaf->map_token) {
3763 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
3764 leaf->map_token = NULL;
3765 }
3766
5f39d397 3767 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot),
85e21bac 3768 btrfs_item_nr_offset(slot + nr),
d6025579 3769 sizeof(struct btrfs_item) *
85e21bac 3770 (nritems - slot - nr));
be0e5c09 3771 }
85e21bac
CM		 3772 btrfs_set_header_nritems(leaf, nritems - nr);
3773 nritems -= nr;
5f39d397 3774
74123bd7 3775 /* delete the leaf if we've emptied it */
7518a238 3776 if (nritems == 0) {
5f39d397
CM		 3777 if (leaf == root->node) {
3778 btrfs_set_header_level(leaf, 0);
9a8dd150 3779 } else {
5d4f98a2 3780 ret = btrfs_del_leaf(trans, root, path, leaf);
323ac95b 3781 BUG_ON(ret);
9a8dd150 3782 }
be0e5c09 3783 } else {
7518a238 3784 int used = leaf_space_used(leaf, 0, nritems);
aa5d6bed 3785 if (slot == 0) {
5f39d397
CM		 3786 struct btrfs_disk_key disk_key;
3787
3788 btrfs_item_key(leaf, &disk_key, 0);
e089f05c 3789 wret = fixup_low_keys(trans, root, path,
5f39d397 3790 &disk_key, 1);
aa5d6bed
CM		 3791 if (wret)
3792 ret = wret;
3793 }
aa5d6bed 3794
74123bd7 3795 /* delete the leaf if it is mostly empty */
d717aa1d 3796 if (used < BTRFS_LEAF_DATA_SIZE(root) / 3) {
be0e5c09
CM		 3797 /* push_leaf_left fixes the path.
3798 * make sure the path still points to our leaf
3799 * for possible call to del_ptr below
3800 */
4920c9ac 3801 slot = path->slots[1];
5f39d397
CM		 3802 extent_buffer_get(leaf);
3803
b9473439 3804 btrfs_set_path_blocking(path);
85e21bac 3805 wret = push_leaf_left(trans, root, path, 1, 1);
54aa1f4d 3806 if (wret < 0 && wret != -ENOSPC)
aa5d6bed 3807 ret = wret;
5f39d397
CM		 3808
3809 if (path->nodes[0] == leaf &&
3810 btrfs_header_nritems(leaf)) {
85e21bac 3811 wret = push_leaf_right(trans, root, path, 1, 1);
54aa1f4d 3812 if (wret < 0 && wret != -ENOSPC)
aa5d6bed
CM		 3813 ret = wret;
3814 }
5f39d397
CM		 3815
3816 if (btrfs_header_nritems(leaf) == 0) {
323ac95b 3817 path->slots[1] = slot;
5d4f98a2 3818 ret = btrfs_del_leaf(trans, root, path, leaf);
323ac95b 3819 BUG_ON(ret);
5f39d397 3820 free_extent_buffer(leaf);
5de08d7d 3821 } else {
925baedd
CM		 3822 /* if we're still in the path, make sure
3823 * we're dirty. Otherwise, one of the
3824 * push_leaf functions must have already
3825 * dirtied this buffer
3826 */
3827 if (path->nodes[0] == leaf)
3828 btrfs_mark_buffer_dirty(leaf);
5f39d397 3829 free_extent_buffer(leaf);
be0e5c09 3830 }
d5719762 3831 } else {
5f39d397 3832 btrfs_mark_buffer_dirty(leaf);
be0e5c09
CM		 3833 }
3834 }
aa5d6bed 3835 return ret;
be0e5c09
CM		 3836}
3837
7bb86316 3838/*
925baedd 3839 * search the tree again to find a leaf with lesser keys
7bb86316
CM		 3840 * returns 0 if it found something or 1 if there are no lesser leaves.
3841 * returns < 0 on io errors.
d352ac68
CM		 3842 *
3843 * This may release the path, and so you may lose any locks held at the
3844 * time you call it.
7bb86316
CM		 3845 */
3846int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path)
3847{
925baedd
CM		 3848 struct btrfs_key key;
3849 struct btrfs_disk_key found_key;
3850 int ret;
7bb86316 3851
925baedd 3852 btrfs_item_key_to_cpu(path->nodes[0], &key, 0);
7bb86316 3853
925baedd
CM		 3854 if (key.offset > 0)
3855 key.offset--;
3856 else if (key.type > 0)
3857 key.type--;
3858 else if (key.objectid > 0)
3859 key.objectid--;
3860 else
3861 return 1;
7bb86316 3862
925baedd
CM		 3863 btrfs_release_path(root, path);
3864 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3865 if (ret < 0)
3866 return ret;
3867 btrfs_item_key(path->nodes[0], &found_key, 0);
3868 ret = comp_keys(&found_key, &key);
3869 if (ret < 0)
3870 return 0;
3871 return 1;
7bb86316
CM		 3872}
3873
3f157a2f
CM		 3874/*
3875 * A helper function to walk down the tree starting at min_key, and looking
3876 * for nodes or leaves that are either in cache or have a minimum
d352ac68 3877 * transaction id. This is used by the btree defrag code, and tree logging
3f157a2f
CM		 3878 *
3879 * This does not cow, but it does stuff the starting key it finds back
3880 * into min_key, so you can call btrfs_search_slot with cow=1 on the
3881 * key and get a writable path.
3882 *
3883 * This does lock as it descends, and path->keep_locks should be set
3884 * to 1 by the caller.
3885 *
3886 * This honors path->lowest_level to prevent descent past a given level
3887 * of the tree.
3888 *
d352ac68
CM		 3889 * min_trans indicates the oldest transaction that you are interested
3890 * in walking through. Any nodes or leaves older than min_trans are
3891 * skipped over (without reading them).
3892 *
3f157a2f
CM		 3893 * returns zero if something useful was found, < 0 on error and 1 if there
3894 * was nothing in the tree that matched the search criteria.
3895 */
3896int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key,
e02119d5 3897 struct btrfs_key *max_key,
3f157a2f
CM		 3898 struct btrfs_path *path, int cache_only,
3899 u64 min_trans)
3900{
3901 struct extent_buffer *cur;
3902 struct btrfs_key found_key;
3903 int slot;
9652480b 3904 int sret;
3f157a2f
CM		 3905 u32 nritems;
3906 int level;
3907 int ret = 1;
3908
934d375b 3909 WARN_ON(!path->keep_locks);
3f157a2f
CM		 3910again:
3911 cur = btrfs_lock_root_node(root);
3912 level = btrfs_header_level(cur);
e02119d5 3913 WARN_ON(path->nodes[level]);
3f157a2f
CM		 3914 path->nodes[level] = cur;
3915 path->locks[level] = 1;
3916
3917 if (btrfs_header_generation(cur) < min_trans) {
3918 ret = 1;
3919 goto out;
3920 }
d397712b 3921 while (1) {
3f157a2f
CM		 3922 nritems = btrfs_header_nritems(cur);
3923 level = btrfs_header_level(cur);
9652480b 3924 sret = bin_search(cur, min_key, level, &slot);
3f157a2f 3925
323ac95b
CM		 3926 /* at the lowest level, we're done, setup the path and exit */
3927 if (level == path->lowest_level) {
e02119d5
CM		 3928 if (slot >= nritems)
3929 goto find_next_key;
3f157a2f
CM		 3930 ret = 0;
3931 path->slots[level] = slot;
3932 btrfs_item_key_to_cpu(cur, &found_key, slot);
3933 goto out;
3934 }
9652480b
Y		 3935 if (sret && slot > 0)
3936 slot--;
3f157a2f
CM		 3937 /*
3938 * check this node pointer against the cache_only and
3939 * min_trans parameters. If it isn't in cache or is too
3940 * old, skip to the next one.
3941 */
d397712b 3942 while (slot < nritems) {
3f157a2f
CM		 3943 u64 blockptr;
3944 u64 gen;
3945 struct extent_buffer *tmp;
e02119d5
CM		 3946 struct btrfs_disk_key disk_key;
3947
3f157a2f
CM		 3948 blockptr = btrfs_node_blockptr(cur, slot);
3949 gen = btrfs_node_ptr_generation(cur, slot);
3950 if (gen < min_trans) {
3951 slot++;
3952 continue;
3953 }
3954 if (!cache_only)
3955 break;
3956
e02119d5
CM		 3957 if (max_key) {
3958 btrfs_node_key(cur, &disk_key, slot);
3959 if (comp_keys(&disk_key, max_key) >= 0) {
3960 ret = 1;
3961 goto out;
3962 }
3963 }
3964
3f157a2f
CM		 3965 tmp = btrfs_find_tree_block(root, blockptr,
3966 btrfs_level_size(root, level - 1));
3967
3968 if (tmp && btrfs_buffer_uptodate(tmp, gen)) {
3969 free_extent_buffer(tmp);
3970 break;
3971 }
3972 if (tmp)
3973 free_extent_buffer(tmp);
3974 slot++;
3975 }
e02119d5 3976find_next_key:
3f157a2f
CM		 3977 /*
3978 * we didn't find a candidate key in this node, walk forward
3979 * and find another one
3980 */
3981 if (slot >= nritems) {
e02119d5 3982 path->slots[level] = slot;
b4ce94de 3983 btrfs_set_path_blocking(path);
e02119d5 3984 sret = btrfs_find_next_key(root, path, min_key, level,
3f157a2f 3985 cache_only, min_trans);
e02119d5 3986 if (sret == 0) {
3f157a2f
CM		 3987 btrfs_release_path(root, path);
3988 goto again;
3989 } else {
3990 goto out;
3991 }
3992 }
3993 /* save our key for returning back */
3994 btrfs_node_key_to_cpu(cur, &found_key, slot);
3995 path->slots[level] = slot;
3996 if (level == path->lowest_level) {
3997 ret = 0;
3998 unlock_up(path, level, 1);
3999 goto out;
4000 }
b4ce94de 4001 btrfs_set_path_blocking(path);
3f157a2f
CM		 4002 cur = read_node_slot(root, cur, slot);
4003
4004 btrfs_tree_lock(cur);
b4ce94de 4005
3f157a2f
CM		 4006 path->locks[level - 1] = 1;
4007 path->nodes[level - 1] = cur;
4008 unlock_up(path, level, 1);
4008c04a 4009 btrfs_clear_path_blocking(path, NULL);
3f157a2f
CM		 4010 }
4011out:
4012 if (ret == 0)
4013 memcpy(min_key, &found_key, sizeof(found_key));
b4ce94de 4014 btrfs_set_path_blocking(path);
3f157a2f
CM		 4015 return ret;
4016}
4017
4018/*
4019 * this is similar to btrfs_next_leaf, but does not try to preserve
4020 * and fixup the path. It looks for and returns the next key in the
4021 * tree based on the current path and the cache_only and min_trans
4022 * parameters.
4023 *
4024 * 0 is returned if another key is found, < 0 if there are any errors
4025 * and 1 is returned if there are no higher keys in the tree
4026 *
4027 * path->keep_locks should be set to 1 on the search made before
4028 * calling this function.
4029 */
e7a84565 4030int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path,
33c66f43 4031 struct btrfs_key *key, int level,
3f157a2f 4032 int cache_only, u64 min_trans)
e7a84565 4033{
e7a84565
CM		 4034 int slot;
4035 struct extent_buffer *c;
4036
934d375b 4037 WARN_ON(!path->keep_locks);
d397712b 4038 while (level < BTRFS_MAX_LEVEL) {
e7a84565
CM		 4039 if (!path->nodes[level])
4040 return 1;
4041
4042 slot = path->slots[level] + 1;
4043 c = path->nodes[level];
3f157a2f 4044next:
e7a84565 4045 if (slot >= btrfs_header_nritems(c)) {
33c66f43
YZ		 4046 int ret;
4047 int orig_lowest;
4048 struct btrfs_key cur_key;
4049 if (level + 1 >= BTRFS_MAX_LEVEL ||
4050 !path->nodes[level + 1])
e7a84565 4051 return 1;
33c66f43
YZ		 4052
4053 if (path->locks[level + 1]) {
4054 level++;
4055 continue;
4056 }
4057
4058 slot = btrfs_header_nritems(c) - 1;
4059 if (level == 0)
4060 btrfs_item_key_to_cpu(c, &cur_key, slot);
4061 else
4062 btrfs_node_key_to_cpu(c, &cur_key, slot);
4063
4064 orig_lowest = path->lowest_level;
4065 btrfs_release_path(root, path);
4066 path->lowest_level = level;
4067 ret = btrfs_search_slot(NULL, root, &cur_key, path,
4068 0, 0);
4069 path->lowest_level = orig_lowest;
4070 if (ret < 0)
4071 return ret;
4072
4073 c = path->nodes[level];
4074 slot = path->slots[level];
4075 if (ret == 0)
4076 slot++;
4077 goto next;
e7a84565 4078 }
33c66f43 4079
e7a84565
CM		 4080 if (level == 0)
4081 btrfs_item_key_to_cpu(c, key, slot);
3f157a2f
CM		 4082 else {
4083 u64 blockptr = btrfs_node_blockptr(c, slot);
4084 u64 gen = btrfs_node_ptr_generation(c, slot);
4085
4086 if (cache_only) {
4087 struct extent_buffer *cur;
4088 cur = btrfs_find_tree_block(root, blockptr,
4089 btrfs_level_size(root, level - 1));
4090 if (!cur || !btrfs_buffer_uptodate(cur, gen)) {
4091 slot++;
4092 if (cur)
4093 free_extent_buffer(cur);
4094 goto next;
4095 }
4096 free_extent_buffer(cur);
4097 }
4098 if (gen < min_trans) {
4099 slot++;
4100 goto next;
4101 }
e7a84565 4102 btrfs_node_key_to_cpu(c, key, slot);
3f157a2f 4103 }
e7a84565
CM		 4104 return 0;
4105 }
4106 return 1;
4107}
4108
97571fd0 4109/*
925baedd 4110 * search the tree again to find a leaf with greater keys
0f70abe2
CM		 4111 * returns 0 if it found something or 1 if there are no greater leaves.
4112 * returns < 0 on io errors.
97571fd0 4113 */
234b63a0 4114int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path)
d97e63b6
CM		 4115{
4116 int slot;
8e73f275 4117 int level;
5f39d397 4118 struct extent_buffer *c;
8e73f275 4119 struct extent_buffer *next;
925baedd
CM		 4120 struct btrfs_key key;
4121 u32 nritems;
4122 int ret;
8e73f275
CM		 4123 int old_spinning = path->leave_spinning;
4124 int force_blocking = 0;
925baedd
CM		 4125
4126 nritems = btrfs_header_nritems(path->nodes[0]);
d397712b 4127 if (nritems == 0)
925baedd 4128 return 1;
925baedd 4129
8e73f275
CM		 4130 /*
4131 * we take the blocks in an order that upsets lockdep. Using
4132 * blocking mode is the only way around it.
4133 */
4134#ifdef CONFIG_DEBUG_LOCK_ALLOC
4135 force_blocking = 1;
4136#endif
925baedd 4137
8e73f275
CM		 4138 btrfs_item_key_to_cpu(path->nodes[0], &key, nritems - 1);
4139again:
4140 level = 1;
4141 next = NULL;
925baedd 4142 btrfs_release_path(root, path);
8e73f275 4143
a2135011 4144 path->keep_locks = 1;
8e73f275
CM		 4145
4146 if (!force_blocking)
4147 path->leave_spinning = 1;
4148
925baedd
CM		 4149 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4150 path->keep_locks = 0;
4151
4152 if (ret < 0)
4153 return ret;
4154
a2135011 4155 nritems = btrfs_header_nritems(path->nodes[0]);
168fd7d2
CM		 4156 /*
4157 * by releasing the path above we dropped all our locks. A balance
4158 * could have added more items next to the key that used to be
4159 * at the very end of the block. So, check again here and
4160 * advance the path if there are now more items available.
4161 */
a2135011 4162 if (nritems > 0 && path->slots[0] < nritems - 1) {
e457afec
YZ		 4163 if (ret == 0)
4164 path->slots[0]++;
8e73f275 4165 ret = 0;
925baedd
CM		 4166 goto done;
4167 }
d97e63b6 4168
d397712b 4169 while (level < BTRFS_MAX_LEVEL) {
8e73f275
CM		 4170 if (!path->nodes[level]) {
4171 ret = 1;
4172 goto done;
4173 }
5f39d397 4174
d97e63b6
CM		 4175 slot = path->slots[level] + 1;
4176 c = path->nodes[level];
5f39d397 4177 if (slot >= btrfs_header_nritems(c)) {
d97e63b6 4178 level++;
8e73f275
CM		 4179 if (level == BTRFS_MAX_LEVEL) {
4180 ret = 1;
4181 goto done;
4182 }
d97e63b6
CM		 4183 continue;
4184 }
5f39d397 4185
925baedd
CM		 4186 if (next) {
4187 btrfs_tree_unlock(next);
5f39d397 4188 free_extent_buffer(next);
925baedd 4189 }
5f39d397 4190
8e73f275
CM		 4191 next = c;
4192 ret = read_block_for_search(NULL, root, path, &next, level,
4193 slot, &key);
4194 if (ret == -EAGAIN)
4195 goto again;
5f39d397 4196
76a05b35
CM		 4197 if (ret < 0) {
4198 btrfs_release_path(root, path);
4199 goto done;
4200 }
4201
5cd57b2c 4202 if (!path->skip_locking) {
8e73f275
CM		 4203 ret = btrfs_try_spin_lock(next);
4204 if (!ret) {
4205 btrfs_set_path_blocking(path);
4206 btrfs_tree_lock(next);
4207 if (!force_blocking)
4208 btrfs_clear_path_blocking(path, next);
4209 }
4210 if (force_blocking)
4211 btrfs_set_lock_blocking(next);
5cd57b2c 4212 }
d97e63b6
CM		 4213 break;
4214 }
4215 path->slots[level] = slot;
d397712b 4216 while (1) {
d97e63b6
CM		 4217 level--;
4218 c = path->nodes[level];
925baedd
CM		 4219 if (path->locks[level])
4220 btrfs_tree_unlock(c);
8e73f275 4221
5f39d397 4222 free_extent_buffer(c);
d97e63b6
CM		 4223 path->nodes[level] = next;
4224 path->slots[level] = 0;
a74a4b97
CM		 4225 if (!path->skip_locking)
4226 path->locks[level] = 1;
8e73f275 4227
d97e63b6
CM		 4228 if (!level)
4229 break;
b4ce94de 4230
8e73f275
CM		 4231 ret = read_block_for_search(NULL, root, path, &next, level,
4232 0, &key);
4233 if (ret == -EAGAIN)
4234 goto again;
4235
76a05b35
CM		 4236 if (ret < 0) {
4237 btrfs_release_path(root, path);
4238 goto done;
4239 }
4240
5cd57b2c 4241 if (!path->skip_locking) {
b9447ef8 4242 btrfs_assert_tree_locked(path->nodes[level]);
8e73f275
CM		 4243 ret = btrfs_try_spin_lock(next);
4244 if (!ret) {
4245 btrfs_set_path_blocking(path);
4246 btrfs_tree_lock(next);
4247 if (!force_blocking)
4248 btrfs_clear_path_blocking(path, next);
4249 }
4250 if (force_blocking)
4251 btrfs_set_lock_blocking(next);
5cd57b2c 4252 }
d97e63b6 4253 }
8e73f275 4254 ret = 0;
925baedd
CM		 4255done:
4256 unlock_up(path, 0, 1);
8e73f275
CM		 4257 path->leave_spinning = old_spinning;
4258 if (!old_spinning)
4259 btrfs_set_path_blocking(path);
4260
4261 return ret;
d97e63b6 4262}
0b86a832 4263
3f157a2f
CM		 4264/*
4265 * this uses btrfs_prev_leaf to walk backwards in the tree, and keeps
4266 * searching until it gets past min_objectid or finds an item of 'type'
4267 *
4268 * returns 0 if something is found, 1 if nothing was found and < 0 on error
4269 */
0b86a832
CM		 4270int btrfs_previous_item(struct btrfs_root *root,
4271 struct btrfs_path *path, u64 min_objectid,
4272 int type)
4273{
4274 struct btrfs_key found_key;
4275 struct extent_buffer *leaf;
e02119d5 4276 u32 nritems;
0b86a832
CM		 4277 int ret;
4278
d397712b 4279 while (1) {
0b86a832 4280 if (path->slots[0] == 0) {
b4ce94de 4281 btrfs_set_path_blocking(path);
0b86a832
CM		 4282 ret = btrfs_prev_leaf(root, path);
4283 if (ret != 0)
4284 return ret;
4285 } else {
4286 path->slots[0]--;
4287 }
4288 leaf = path->nodes[0];
e02119d5
CM		 4289 nritems = btrfs_header_nritems(leaf);
4290 if (nritems == 0)
4291 return 1;
4292 if (path->slots[0] == nritems)
4293 path->slots[0]--;
4294
0b86a832 4295 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
e02119d5
CM		 4296 if (found_key.objectid < min_objectid)
4297 break;
0a4eefbb
YZ		 4298 if (found_key.type == type)
4299 return 0;
e02119d5
CM		 4300 if (found_key.objectid == min_objectid &&
4301 found_key.type < type)
4302 break;
0b86a832
CM		 4303 }
4304 return 1;
4305}
Linux 6.x block layer and io_uring tree(s)