]>
Commit | Line | Data |
---|---|---|
1 | /* | |
2 | * Copyright (C) 2007,2008 Oracle. All rights reserved. | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU General Public | |
6 | * License v2 as published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, | |
9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
11 | * General Public License for more details. | |
12 | * | |
13 | * You should have received a copy of the GNU General Public | |
14 | * License along with this program; if not, write to the | |
15 | * Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
16 | * Boston, MA 021110-1307, USA. | |
17 | */ | |
18 | ||
19 | #include <linux/sched.h> | |
20 | #include <linux/slab.h> | |
21 | #include "ctree.h" | |
22 | #include "disk-io.h" | |
23 | #include "transaction.h" | |
24 | #include "print-tree.h" | |
25 | #include "locking.h" | |
26 | ||
27 | static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root | |
28 | *root, struct btrfs_path *path, int level); | |
29 | static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root | |
30 | *root, struct btrfs_key *ins_key, | |
31 | struct btrfs_path *path, int data_size, int extend); | |
32 | static int push_node_left(struct btrfs_trans_handle *trans, | |
33 | struct btrfs_root *root, struct extent_buffer *dst, | |
34 | struct extent_buffer *src, int empty); | |
35 | static int balance_node_right(struct btrfs_trans_handle *trans, | |
36 | struct btrfs_root *root, | |
37 | struct extent_buffer *dst_buf, | |
38 | struct extent_buffer *src_buf); | |
39 | static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root, | |
40 | struct btrfs_path *path, int level, int slot); | |
41 | static int setup_items_for_insert(struct btrfs_trans_handle *trans, | |
42 | struct btrfs_root *root, struct btrfs_path *path, | |
43 | struct btrfs_key *cpu_key, u32 *data_size, | |
44 | u32 total_data, u32 total_size, int nr); | |
45 | ||
46 | ||
47 | struct btrfs_path *btrfs_alloc_path(void) | |
48 | { | |
49 | struct btrfs_path *path; | |
50 | path = kmem_cache_zalloc(btrfs_path_cachep, GFP_NOFS); | |
51 | if (path) | |
52 | path->reada = 1; | |
53 | return path; | |
54 | } | |
55 | ||
56 | /* | |
57 | * set all locked nodes in the path to blocking locks. This should | |
58 | * be done before scheduling | |
59 | */ | |
60 | noinline void btrfs_set_path_blocking(struct btrfs_path *p) | |
61 | { | |
62 | int i; | |
63 | for (i = 0; i < BTRFS_MAX_LEVEL; i++) { | |
64 | if (p->nodes[i] && p->locks[i]) | |
65 | btrfs_set_lock_blocking(p->nodes[i]); | |
66 | } | |
67 | } | |
68 | ||
69 | /* | |
70 | * reset all the locked nodes in the patch to spinning locks. | |
71 | * | |
72 | * held is used to keep lockdep happy, when lockdep is enabled | |
73 | * we set held to a blocking lock before we go around and | |
74 | * retake all the spinlocks in the path. You can safely use NULL | |
75 | * for held | |
76 | */ | |
77 | noinline void btrfs_clear_path_blocking(struct btrfs_path *p, | |
78 | struct extent_buffer *held) | |
79 | { | |
80 | int i; | |
81 | ||
82 | #ifdef CONFIG_DEBUG_LOCK_ALLOC | |
83 | /* lockdep really cares that we take all of these spinlocks | |
84 | * in the right order. If any of the locks in the path are not | |
85 | * currently blocking, it is going to complain. So, make really | |
86 | * really sure by forcing the path to blocking before we clear | |
87 | * the path blocking. | |
88 | */ | |
89 | if (held) | |
90 | btrfs_set_lock_blocking(held); | |
91 | btrfs_set_path_blocking(p); | |
92 | #endif | |
93 | ||
94 | for (i = BTRFS_MAX_LEVEL - 1; i >= 0; i--) { | |
95 | if (p->nodes[i] && p->locks[i]) | |
96 | btrfs_clear_lock_blocking(p->nodes[i]); | |
97 | } | |
98 | ||
99 | #ifdef CONFIG_DEBUG_LOCK_ALLOC | |
100 | if (held) | |
101 | btrfs_clear_lock_blocking(held); | |
102 | #endif | |
103 | } | |
104 | ||
105 | /* this also releases the path */ | |
106 | void btrfs_free_path(struct btrfs_path *p) | |
107 | { | |
108 | btrfs_release_path(NULL, p); | |
109 | kmem_cache_free(btrfs_path_cachep, p); | |
110 | } | |
111 | ||
112 | /* | |
113 | * path release drops references on the extent buffers in the path | |
114 | * and it drops any locks held by this path | |
115 | * | |
116 | * It is safe to call this on paths that no locks or extent buffers held. | |
117 | */ | |
118 | noinline void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p) | |
119 | { | |
120 | int i; | |
121 | ||
122 | for (i = 0; i < BTRFS_MAX_LEVEL; i++) { | |
123 | p->slots[i] = 0; | |
124 | if (!p->nodes[i]) | |
125 | continue; | |
126 | if (p->locks[i]) { | |
127 | btrfs_tree_unlock(p->nodes[i]); | |
128 | p->locks[i] = 0; | |
129 | } | |
130 | free_extent_buffer(p->nodes[i]); | |
131 | p->nodes[i] = NULL; | |
132 | } | |
133 | } | |
134 | ||
135 | /* | |
136 | * safely gets a reference on the root node of a tree. A lock | |
137 | * is not taken, so a concurrent writer may put a different node | |
138 | * at the root of the tree. See btrfs_lock_root_node for the | |
139 | * looping required. | |
140 | * | |
141 | * The extent buffer returned by this has a reference taken, so | |
142 | * it won't disappear. It may stop being the root of the tree | |
143 | * at any time because there are no locks held. | |
144 | */ | |
145 | struct extent_buffer *btrfs_root_node(struct btrfs_root *root) | |
146 | { | |
147 | struct extent_buffer *eb; | |
148 | spin_lock(&root->node_lock); | |
149 | eb = root->node; | |
150 | extent_buffer_get(eb); | |
151 | spin_unlock(&root->node_lock); | |
152 | return eb; | |
153 | } | |
154 | ||
155 | /* loop around taking references on and locking the root node of the | |
156 | * tree until you end up with a lock on the root. A locked buffer | |
157 | * is returned, with a reference held. | |
158 | */ | |
159 | struct extent_buffer *btrfs_lock_root_node(struct btrfs_root *root) | |
160 | { | |
161 | struct extent_buffer *eb; | |
162 | ||
163 | while (1) { | |
164 | eb = btrfs_root_node(root); | |
165 | btrfs_tree_lock(eb); | |
166 | ||
167 | spin_lock(&root->node_lock); | |
168 | if (eb == root->node) { | |
169 | spin_unlock(&root->node_lock); | |
170 | break; | |
171 | } | |
172 | spin_unlock(&root->node_lock); | |
173 | ||
174 | btrfs_tree_unlock(eb); | |
175 | free_extent_buffer(eb); | |
176 | } | |
177 | return eb; | |
178 | } | |
179 | ||
180 | /* cowonly root (everything not a reference counted cow subvolume), just get | |
181 | * put onto a simple dirty list. transaction.c walks this to make sure they | |
182 | * get properly updated on disk. | |
183 | */ | |
184 | static void add_root_to_dirty_list(struct btrfs_root *root) | |
185 | { | |
186 | if (root->track_dirty && list_empty(&root->dirty_list)) { | |
187 | list_add(&root->dirty_list, | |
188 | &root->fs_info->dirty_cowonly_roots); | |
189 | } | |
190 | } | |
191 | ||
192 | /* | |
193 | * used by snapshot creation to make a copy of a root for a tree with | |
194 | * a given objectid. The buffer with the new root node is returned in | |
195 | * cow_ret, and this func returns zero on success or a negative error code. | |
196 | */ | |
197 | int btrfs_copy_root(struct btrfs_trans_handle *trans, | |
198 | struct btrfs_root *root, | |
199 | struct extent_buffer *buf, | |
200 | struct extent_buffer **cow_ret, u64 new_root_objectid) | |
201 | { | |
202 | struct extent_buffer *cow; | |
203 | u32 nritems; | |
204 | int ret = 0; | |
205 | int level; | |
206 | struct btrfs_disk_key disk_key; | |
207 | ||
208 | WARN_ON(root->ref_cows && trans->transid != | |
209 | root->fs_info->running_transaction->transid); | |
210 | WARN_ON(root->ref_cows && trans->transid != root->last_trans); | |
211 | ||
212 | level = btrfs_header_level(buf); | |
213 | nritems = btrfs_header_nritems(buf); | |
214 | if (level == 0) | |
215 | btrfs_item_key(buf, &disk_key, 0); | |
216 | else | |
217 | btrfs_node_key(buf, &disk_key, 0); | |
218 | ||
219 | cow = btrfs_alloc_free_block(trans, root, buf->len, 0, | |
220 | new_root_objectid, &disk_key, level, | |
221 | buf->start, 0); | |
222 | if (IS_ERR(cow)) | |
223 | return PTR_ERR(cow); | |
224 | ||
225 | copy_extent_buffer(cow, buf, 0, 0, cow->len); | |
226 | btrfs_set_header_bytenr(cow, cow->start); | |
227 | btrfs_set_header_generation(cow, trans->transid); | |
228 | btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV); | |
229 | btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN | | |
230 | BTRFS_HEADER_FLAG_RELOC); | |
231 | if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID) | |
232 | btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC); | |
233 | else | |
234 | btrfs_set_header_owner(cow, new_root_objectid); | |
235 | ||
236 | write_extent_buffer(cow, root->fs_info->fsid, | |
237 | (unsigned long)btrfs_header_fsid(cow), | |
238 | BTRFS_FSID_SIZE); | |
239 | ||
240 | WARN_ON(btrfs_header_generation(buf) > trans->transid); | |
241 | if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID) | |
242 | ret = btrfs_inc_ref(trans, root, cow, 1); | |
243 | else | |
244 | ret = btrfs_inc_ref(trans, root, cow, 0); | |
245 | ||
246 | if (ret) | |
247 | return ret; | |
248 | ||
249 | btrfs_mark_buffer_dirty(cow); | |
250 | *cow_ret = cow; | |
251 | return 0; | |
252 | } | |
253 | ||
254 | /* | |
255 | * check if the tree block can be shared by multiple trees | |
256 | */ | |
257 | int btrfs_block_can_be_shared(struct btrfs_root *root, | |
258 | struct extent_buffer *buf) | |
259 | { | |
260 | /* | |
261 | * Tree blocks not in refernece counted trees and tree roots | |
262 | * are never shared. If a block was allocated after the last | |
263 | * snapshot and the block was not allocated by tree relocation, | |
264 | * we know the block is not shared. | |
265 | */ | |
266 | if (root->ref_cows && | |
267 | buf != root->node && buf != root->commit_root && | |
268 | (btrfs_header_generation(buf) <= | |
269 | btrfs_root_last_snapshot(&root->root_item) || | |
270 | btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC))) | |
271 | return 1; | |
272 | #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 | |
273 | if (root->ref_cows && | |
274 | btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) | |
275 | return 1; | |
276 | #endif | |
277 | return 0; | |
278 | } | |
279 | ||
280 | static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans, | |
281 | struct btrfs_root *root, | |
282 | struct extent_buffer *buf, | |
283 | struct extent_buffer *cow, | |
284 | int *last_ref) | |
285 | { | |
286 | u64 refs; | |
287 | u64 owner; | |
288 | u64 flags; | |
289 | u64 new_flags = 0; | |
290 | int ret; | |
291 | ||
292 | /* | |
293 | * Backrefs update rules: | |
294 | * | |
295 | * Always use full backrefs for extent pointers in tree block | |
296 | * allocated by tree relocation. | |
297 | * | |
298 | * If a shared tree block is no longer referenced by its owner | |
299 | * tree (btrfs_header_owner(buf) == root->root_key.objectid), | |
300 | * use full backrefs for extent pointers in tree block. | |
301 | * | |
302 | * If a tree block is been relocating | |
303 | * (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID), | |
304 | * use full backrefs for extent pointers in tree block. | |
305 | * The reason for this is some operations (such as drop tree) | |
306 | * are only allowed for blocks use full backrefs. | |
307 | */ | |
308 | ||
309 | if (btrfs_block_can_be_shared(root, buf)) { | |
310 | ret = btrfs_lookup_extent_info(trans, root, buf->start, | |
311 | buf->len, &refs, &flags); | |
312 | BUG_ON(ret); | |
313 | BUG_ON(refs == 0); | |
314 | } else { | |
315 | refs = 1; | |
316 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID || | |
317 | btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) | |
318 | flags = BTRFS_BLOCK_FLAG_FULL_BACKREF; | |
319 | else | |
320 | flags = 0; | |
321 | } | |
322 | ||
323 | owner = btrfs_header_owner(buf); | |
324 | BUG_ON(owner == BTRFS_TREE_RELOC_OBJECTID && | |
325 | !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)); | |
326 | ||
327 | if (refs > 1) { | |
328 | if ((owner == root->root_key.objectid || | |
329 | root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) && | |
330 | !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)) { | |
331 | ret = btrfs_inc_ref(trans, root, buf, 1); | |
332 | BUG_ON(ret); | |
333 | ||
334 | if (root->root_key.objectid == | |
335 | BTRFS_TREE_RELOC_OBJECTID) { | |
336 | ret = btrfs_dec_ref(trans, root, buf, 0); | |
337 | BUG_ON(ret); | |
338 | ret = btrfs_inc_ref(trans, root, cow, 1); | |
339 | BUG_ON(ret); | |
340 | } | |
341 | new_flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF; | |
342 | } else { | |
343 | ||
344 | if (root->root_key.objectid == | |
345 | BTRFS_TREE_RELOC_OBJECTID) | |
346 | ret = btrfs_inc_ref(trans, root, cow, 1); | |
347 | else | |
348 | ret = btrfs_inc_ref(trans, root, cow, 0); | |
349 | BUG_ON(ret); | |
350 | } | |
351 | if (new_flags != 0) { | |
352 | ret = btrfs_set_disk_extent_flags(trans, root, | |
353 | buf->start, | |
354 | buf->len, | |
355 | new_flags, 0); | |
356 | BUG_ON(ret); | |
357 | } | |
358 | } else { | |
359 | if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF) { | |
360 | if (root->root_key.objectid == | |
361 | BTRFS_TREE_RELOC_OBJECTID) | |
362 | ret = btrfs_inc_ref(trans, root, cow, 1); | |
363 | else | |
364 | ret = btrfs_inc_ref(trans, root, cow, 0); | |
365 | BUG_ON(ret); | |
366 | ret = btrfs_dec_ref(trans, root, buf, 1); | |
367 | BUG_ON(ret); | |
368 | } | |
369 | clean_tree_block(trans, root, buf); | |
370 | *last_ref = 1; | |
371 | } | |
372 | return 0; | |
373 | } | |
374 | ||
375 | /* | |
376 | * does the dirty work in cow of a single block. The parent block (if | |
377 | * supplied) is updated to point to the new cow copy. The new buffer is marked | |
378 | * dirty and returned locked. If you modify the block it needs to be marked | |
379 | * dirty again. | |
380 | * | |
381 | * search_start -- an allocation hint for the new block | |
382 | * | |
383 | * empty_size -- a hint that you plan on doing more cow. This is the size in | |
384 | * bytes the allocator should try to find free next to the block it returns. | |
385 | * This is just a hint and may be ignored by the allocator. | |
386 | */ | |
387 | static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans, | |
388 | struct btrfs_root *root, | |
389 | struct extent_buffer *buf, | |
390 | struct extent_buffer *parent, int parent_slot, | |
391 | struct extent_buffer **cow_ret, | |
392 | u64 search_start, u64 empty_size) | |
393 | { | |
394 | struct btrfs_disk_key disk_key; | |
395 | struct extent_buffer *cow; | |
396 | int level; | |
397 | int last_ref = 0; | |
398 | int unlock_orig = 0; | |
399 | u64 parent_start; | |
400 | ||
401 | if (*cow_ret == buf) | |
402 | unlock_orig = 1; | |
403 | ||
404 | btrfs_assert_tree_locked(buf); | |
405 | ||
406 | WARN_ON(root->ref_cows && trans->transid != | |
407 | root->fs_info->running_transaction->transid); | |
408 | WARN_ON(root->ref_cows && trans->transid != root->last_trans); | |
409 | ||
410 | level = btrfs_header_level(buf); | |
411 | ||
412 | if (level == 0) | |
413 | btrfs_item_key(buf, &disk_key, 0); | |
414 | else | |
415 | btrfs_node_key(buf, &disk_key, 0); | |
416 | ||
417 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) { | |
418 | if (parent) | |
419 | parent_start = parent->start; | |
420 | else | |
421 | parent_start = 0; | |
422 | } else | |
423 | parent_start = 0; | |
424 | ||
425 | cow = btrfs_alloc_free_block(trans, root, buf->len, parent_start, | |
426 | root->root_key.objectid, &disk_key, | |
427 | level, search_start, empty_size); | |
428 | if (IS_ERR(cow)) | |
429 | return PTR_ERR(cow); | |
430 | ||
431 | /* cow is set to blocking by btrfs_init_new_buffer */ | |
432 | ||
433 | copy_extent_buffer(cow, buf, 0, 0, cow->len); | |
434 | btrfs_set_header_bytenr(cow, cow->start); | |
435 | btrfs_set_header_generation(cow, trans->transid); | |
436 | btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV); | |
437 | btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN | | |
438 | BTRFS_HEADER_FLAG_RELOC); | |
439 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) | |
440 | btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC); | |
441 | else | |
442 | btrfs_set_header_owner(cow, root->root_key.objectid); | |
443 | ||
444 | write_extent_buffer(cow, root->fs_info->fsid, | |
445 | (unsigned long)btrfs_header_fsid(cow), | |
446 | BTRFS_FSID_SIZE); | |
447 | ||
448 | update_ref_for_cow(trans, root, buf, cow, &last_ref); | |
449 | ||
450 | if (root->ref_cows) | |
451 | btrfs_reloc_cow_block(trans, root, buf, cow); | |
452 | ||
453 | if (buf == root->node) { | |
454 | WARN_ON(parent && parent != buf); | |
455 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID || | |
456 | btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) | |
457 | parent_start = buf->start; | |
458 | else | |
459 | parent_start = 0; | |
460 | ||
461 | spin_lock(&root->node_lock); | |
462 | root->node = cow; | |
463 | extent_buffer_get(cow); | |
464 | spin_unlock(&root->node_lock); | |
465 | ||
466 | btrfs_free_tree_block(trans, root, buf, parent_start, | |
467 | last_ref); | |
468 | free_extent_buffer(buf); | |
469 | add_root_to_dirty_list(root); | |
470 | } else { | |
471 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) | |
472 | parent_start = parent->start; | |
473 | else | |
474 | parent_start = 0; | |
475 | ||
476 | WARN_ON(trans->transid != btrfs_header_generation(parent)); | |
477 | btrfs_set_node_blockptr(parent, parent_slot, | |
478 | cow->start); | |
479 | btrfs_set_node_ptr_generation(parent, parent_slot, | |
480 | trans->transid); | |
481 | btrfs_mark_buffer_dirty(parent); | |
482 | btrfs_free_tree_block(trans, root, buf, parent_start, | |
483 | last_ref); | |
484 | } | |
485 | if (unlock_orig) | |
486 | btrfs_tree_unlock(buf); | |
487 | free_extent_buffer(buf); | |
488 | btrfs_mark_buffer_dirty(cow); | |
489 | *cow_ret = cow; | |
490 | return 0; | |
491 | } | |
492 | ||
493 | static inline int should_cow_block(struct btrfs_trans_handle *trans, | |
494 | struct btrfs_root *root, | |
495 | struct extent_buffer *buf) | |
496 | { | |
497 | if (btrfs_header_generation(buf) == trans->transid && | |
498 | !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN) && | |
499 | !(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID && | |
500 | btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC))) | |
501 | return 0; | |
502 | return 1; | |
503 | } | |
504 | ||
505 | /* | |
506 | * cows a single block, see __btrfs_cow_block for the real work. | |
507 | * This version of it has extra checks so that a block isn't cow'd more than | |
508 | * once per transaction, as long as it hasn't been written yet | |
509 | */ | |
510 | noinline int btrfs_cow_block(struct btrfs_trans_handle *trans, | |
511 | struct btrfs_root *root, struct extent_buffer *buf, | |
512 | struct extent_buffer *parent, int parent_slot, | |
513 | struct extent_buffer **cow_ret) | |
514 | { | |
515 | u64 search_start; | |
516 | int ret; | |
517 | ||
518 | if (trans->transaction != root->fs_info->running_transaction) { | |
519 | printk(KERN_CRIT "trans %llu running %llu\n", | |
520 | (unsigned long long)trans->transid, | |
521 | (unsigned long long) | |
522 | root->fs_info->running_transaction->transid); | |
523 | WARN_ON(1); | |
524 | } | |
525 | if (trans->transid != root->fs_info->generation) { | |
526 | printk(KERN_CRIT "trans %llu running %llu\n", | |
527 | (unsigned long long)trans->transid, | |
528 | (unsigned long long)root->fs_info->generation); | |
529 | WARN_ON(1); | |
530 | } | |
531 | ||
532 | if (!should_cow_block(trans, root, buf)) { | |
533 | *cow_ret = buf; | |
534 | return 0; | |
535 | } | |
536 | ||
537 | search_start = buf->start & ~((u64)(1024 * 1024 * 1024) - 1); | |
538 | ||
539 | if (parent) | |
540 | btrfs_set_lock_blocking(parent); | |
541 | btrfs_set_lock_blocking(buf); | |
542 | ||
543 | ret = __btrfs_cow_block(trans, root, buf, parent, | |
544 | parent_slot, cow_ret, search_start, 0); | |
545 | return ret; | |
546 | } | |
547 | ||
548 | /* | |
549 | * helper function for defrag to decide if two blocks pointed to by a | |
550 | * node are actually close by | |
551 | */ | |
552 | static int close_blocks(u64 blocknr, u64 other, u32 blocksize) | |
553 | { | |
554 | if (blocknr < other && other - (blocknr + blocksize) < 32768) | |
555 | return 1; | |
556 | if (blocknr > other && blocknr - (other + blocksize) < 32768) | |
557 | return 1; | |
558 | return 0; | |
559 | } | |
560 | ||
561 | /* | |
562 | * compare two keys in a memcmp fashion | |
563 | */ | |
564 | static int comp_keys(struct btrfs_disk_key *disk, struct btrfs_key *k2) | |
565 | { | |
566 | struct btrfs_key k1; | |
567 | ||
568 | btrfs_disk_key_to_cpu(&k1, disk); | |
569 | ||
570 | return btrfs_comp_cpu_keys(&k1, k2); | |
571 | } | |
572 | ||
573 | /* | |
574 | * same as comp_keys only with two btrfs_key's | |
575 | */ | |
576 | int btrfs_comp_cpu_keys(struct btrfs_key *k1, struct btrfs_key *k2) | |
577 | { | |
578 | if (k1->objectid > k2->objectid) | |
579 | return 1; | |
580 | if (k1->objectid < k2->objectid) | |
581 | return -1; | |
582 | if (k1->type > k2->type) | |
583 | return 1; | |
584 | if (k1->type < k2->type) | |
585 | return -1; | |
586 | if (k1->offset > k2->offset) | |
587 | return 1; | |
588 | if (k1->offset < k2->offset) | |
589 | return -1; | |
590 | return 0; | |
591 | } | |
592 | ||
593 | /* | |
594 | * this is used by the defrag code to go through all the | |
595 | * leaves pointed to by a node and reallocate them so that | |
596 | * disk order is close to key order | |
597 | */ | |
598 | int btrfs_realloc_node(struct btrfs_trans_handle *trans, | |
599 | struct btrfs_root *root, struct extent_buffer *parent, | |
600 | int start_slot, int cache_only, u64 *last_ret, | |
601 | struct btrfs_key *progress) | |
602 | { | |
603 | struct extent_buffer *cur; | |
604 | u64 blocknr; | |
605 | u64 gen; | |
606 | u64 search_start = *last_ret; | |
607 | u64 last_block = 0; | |
608 | u64 other; | |
609 | u32 parent_nritems; | |
610 | int end_slot; | |
611 | int i; | |
612 | int err = 0; | |
613 | int parent_level; | |
614 | int uptodate; | |
615 | u32 blocksize; | |
616 | int progress_passed = 0; | |
617 | struct btrfs_disk_key disk_key; | |
618 | ||
619 | parent_level = btrfs_header_level(parent); | |
620 | if (cache_only && parent_level != 1) | |
621 | return 0; | |
622 | ||
623 | if (trans->transaction != root->fs_info->running_transaction) | |
624 | WARN_ON(1); | |
625 | if (trans->transid != root->fs_info->generation) | |
626 | WARN_ON(1); | |
627 | ||
628 | parent_nritems = btrfs_header_nritems(parent); | |
629 | blocksize = btrfs_level_size(root, parent_level - 1); | |
630 | end_slot = parent_nritems; | |
631 | ||
632 | if (parent_nritems == 1) | |
633 | return 0; | |
634 | ||
635 | btrfs_set_lock_blocking(parent); | |
636 | ||
637 | for (i = start_slot; i < end_slot; i++) { | |
638 | int close = 1; | |
639 | ||
640 | if (!parent->map_token) { | |
641 | map_extent_buffer(parent, | |
642 | btrfs_node_key_ptr_offset(i), | |
643 | sizeof(struct btrfs_key_ptr), | |
644 | &parent->map_token, &parent->kaddr, | |
645 | &parent->map_start, &parent->map_len, | |
646 | KM_USER1); | |
647 | } | |
648 | btrfs_node_key(parent, &disk_key, i); | |
649 | if (!progress_passed && comp_keys(&disk_key, progress) < 0) | |
650 | continue; | |
651 | ||
652 | progress_passed = 1; | |
653 | blocknr = btrfs_node_blockptr(parent, i); | |
654 | gen = btrfs_node_ptr_generation(parent, i); | |
655 | if (last_block == 0) | |
656 | last_block = blocknr; | |
657 | ||
658 | if (i > 0) { | |
659 | other = btrfs_node_blockptr(parent, i - 1); | |
660 | close = close_blocks(blocknr, other, blocksize); | |
661 | } | |
662 | if (!close && i < end_slot - 2) { | |
663 | other = btrfs_node_blockptr(parent, i + 1); | |
664 | close = close_blocks(blocknr, other, blocksize); | |
665 | } | |
666 | if (close) { | |
667 | last_block = blocknr; | |
668 | continue; | |
669 | } | |
670 | if (parent->map_token) { | |
671 | unmap_extent_buffer(parent, parent->map_token, | |
672 | KM_USER1); | |
673 | parent->map_token = NULL; | |
674 | } | |
675 | ||
676 | cur = btrfs_find_tree_block(root, blocknr, blocksize); | |
677 | if (cur) | |
678 | uptodate = btrfs_buffer_uptodate(cur, gen); | |
679 | else | |
680 | uptodate = 0; | |
681 | if (!cur || !uptodate) { | |
682 | if (cache_only) { | |
683 | free_extent_buffer(cur); | |
684 | continue; | |
685 | } | |
686 | if (!cur) { | |
687 | cur = read_tree_block(root, blocknr, | |
688 | blocksize, gen); | |
689 | } else if (!uptodate) { | |
690 | btrfs_read_buffer(cur, gen); | |
691 | } | |
692 | } | |
693 | if (search_start == 0) | |
694 | search_start = last_block; | |
695 | ||
696 | btrfs_tree_lock(cur); | |
697 | btrfs_set_lock_blocking(cur); | |
698 | err = __btrfs_cow_block(trans, root, cur, parent, i, | |
699 | &cur, search_start, | |
700 | min(16 * blocksize, | |
701 | (end_slot - i) * blocksize)); | |
702 | if (err) { | |
703 | btrfs_tree_unlock(cur); | |
704 | free_extent_buffer(cur); | |
705 | break; | |
706 | } | |
707 | search_start = cur->start; | |
708 | last_block = cur->start; | |
709 | *last_ret = search_start; | |
710 | btrfs_tree_unlock(cur); | |
711 | free_extent_buffer(cur); | |
712 | } | |
713 | if (parent->map_token) { | |
714 | unmap_extent_buffer(parent, parent->map_token, | |
715 | KM_USER1); | |
716 | parent->map_token = NULL; | |
717 | } | |
718 | return err; | |
719 | } | |
720 | ||
721 | /* | |
722 | * The leaf data grows from end-to-front in the node. | |
723 | * this returns the address of the start of the last item, | |
724 | * which is the stop of the leaf data stack | |
725 | */ | |
726 | static inline unsigned int leaf_data_end(struct btrfs_root *root, | |
727 | struct extent_buffer *leaf) | |
728 | { | |
729 | u32 nr = btrfs_header_nritems(leaf); | |
730 | if (nr == 0) | |
731 | return BTRFS_LEAF_DATA_SIZE(root); | |
732 | return btrfs_item_offset_nr(leaf, nr - 1); | |
733 | } | |
734 | ||
735 | /* | |
736 | * extra debugging checks to make sure all the items in a key are | |
737 | * well formed and in the proper order | |
738 | */ | |
739 | static int check_node(struct btrfs_root *root, struct btrfs_path *path, | |
740 | int level) | |
741 | { | |
742 | struct extent_buffer *parent = NULL; | |
743 | struct extent_buffer *node = path->nodes[level]; | |
744 | struct btrfs_disk_key parent_key; | |
745 | struct btrfs_disk_key node_key; | |
746 | int parent_slot; | |
747 | int slot; | |
748 | struct btrfs_key cpukey; | |
749 | u32 nritems = btrfs_header_nritems(node); | |
750 | ||
751 | if (path->nodes[level + 1]) | |
752 | parent = path->nodes[level + 1]; | |
753 | ||
754 | slot = path->slots[level]; | |
755 | BUG_ON(nritems == 0); | |
756 | if (parent) { | |
757 | parent_slot = path->slots[level + 1]; | |
758 | btrfs_node_key(parent, &parent_key, parent_slot); | |
759 | btrfs_node_key(node, &node_key, 0); | |
760 | BUG_ON(memcmp(&parent_key, &node_key, | |
761 | sizeof(struct btrfs_disk_key))); | |
762 | BUG_ON(btrfs_node_blockptr(parent, parent_slot) != | |
763 | btrfs_header_bytenr(node)); | |
764 | } | |
765 | BUG_ON(nritems > BTRFS_NODEPTRS_PER_BLOCK(root)); | |
766 | if (slot != 0) { | |
767 | btrfs_node_key_to_cpu(node, &cpukey, slot - 1); | |
768 | btrfs_node_key(node, &node_key, slot); | |
769 | BUG_ON(comp_keys(&node_key, &cpukey) <= 0); | |
770 | } | |
771 | if (slot < nritems - 1) { | |
772 | btrfs_node_key_to_cpu(node, &cpukey, slot + 1); | |
773 | btrfs_node_key(node, &node_key, slot); | |
774 | BUG_ON(comp_keys(&node_key, &cpukey) >= 0); | |
775 | } | |
776 | return 0; | |
777 | } | |
778 | ||
779 | /* | |
780 | * extra checking to make sure all the items in a leaf are | |
781 | * well formed and in the proper order | |
782 | */ | |
783 | static int check_leaf(struct btrfs_root *root, struct btrfs_path *path, | |
784 | int level) | |
785 | { | |
786 | struct extent_buffer *leaf = path->nodes[level]; | |
787 | struct extent_buffer *parent = NULL; | |
788 | int parent_slot; | |
789 | struct btrfs_key cpukey; | |
790 | struct btrfs_disk_key parent_key; | |
791 | struct btrfs_disk_key leaf_key; | |
792 | int slot = path->slots[0]; | |
793 | ||
794 | u32 nritems = btrfs_header_nritems(leaf); | |
795 | ||
796 | if (path->nodes[level + 1]) | |
797 | parent = path->nodes[level + 1]; | |
798 | ||
799 | if (nritems == 0) | |
800 | return 0; | |
801 | ||
802 | if (parent) { | |
803 | parent_slot = path->slots[level + 1]; | |
804 | btrfs_node_key(parent, &parent_key, parent_slot); | |
805 | btrfs_item_key(leaf, &leaf_key, 0); | |
806 | ||
807 | BUG_ON(memcmp(&parent_key, &leaf_key, | |
808 | sizeof(struct btrfs_disk_key))); | |
809 | BUG_ON(btrfs_node_blockptr(parent, parent_slot) != | |
810 | btrfs_header_bytenr(leaf)); | |
811 | } | |
812 | if (slot != 0 && slot < nritems - 1) { | |
813 | btrfs_item_key(leaf, &leaf_key, slot); | |
814 | btrfs_item_key_to_cpu(leaf, &cpukey, slot - 1); | |
815 | if (comp_keys(&leaf_key, &cpukey) <= 0) { | |
816 | btrfs_print_leaf(root, leaf); | |
817 | printk(KERN_CRIT "slot %d offset bad key\n", slot); | |
818 | BUG_ON(1); | |
819 | } | |
820 | if (btrfs_item_offset_nr(leaf, slot - 1) != | |
821 | btrfs_item_end_nr(leaf, slot)) { | |
822 | btrfs_print_leaf(root, leaf); | |
823 | printk(KERN_CRIT "slot %d offset bad\n", slot); | |
824 | BUG_ON(1); | |
825 | } | |
826 | } | |
827 | if (slot < nritems - 1) { | |
828 | btrfs_item_key(leaf, &leaf_key, slot); | |
829 | btrfs_item_key_to_cpu(leaf, &cpukey, slot + 1); | |
830 | BUG_ON(comp_keys(&leaf_key, &cpukey) >= 0); | |
831 | if (btrfs_item_offset_nr(leaf, slot) != | |
832 | btrfs_item_end_nr(leaf, slot + 1)) { | |
833 | btrfs_print_leaf(root, leaf); | |
834 | printk(KERN_CRIT "slot %d offset bad\n", slot); | |
835 | BUG_ON(1); | |
836 | } | |
837 | } | |
838 | BUG_ON(btrfs_item_offset_nr(leaf, 0) + | |
839 | btrfs_item_size_nr(leaf, 0) != BTRFS_LEAF_DATA_SIZE(root)); | |
840 | return 0; | |
841 | } | |
842 | ||
843 | static noinline int check_block(struct btrfs_root *root, | |
844 | struct btrfs_path *path, int level) | |
845 | { | |
846 | return 0; | |
847 | if (level == 0) | |
848 | return check_leaf(root, path, level); | |
849 | return check_node(root, path, level); | |
850 | } | |
851 | ||
852 | /* | |
853 | * search for key in the extent_buffer. The items start at offset p, | |
854 | * and they are item_size apart. There are 'max' items in p. | |
855 | * | |
856 | * the slot in the array is returned via slot, and it points to | |
857 | * the place where you would insert key if it is not found in | |
858 | * the array. | |
859 | * | |
860 | * slot may point to max if the key is bigger than all of the keys | |
861 | */ | |
862 | static noinline int generic_bin_search(struct extent_buffer *eb, | |
863 | unsigned long p, | |
864 | int item_size, struct btrfs_key *key, | |
865 | int max, int *slot) | |
866 | { | |
867 | int low = 0; | |
868 | int high = max; | |
869 | int mid; | |
870 | int ret; | |
871 | struct btrfs_disk_key *tmp = NULL; | |
872 | struct btrfs_disk_key unaligned; | |
873 | unsigned long offset; | |
874 | char *map_token = NULL; | |
875 | char *kaddr = NULL; | |
876 | unsigned long map_start = 0; | |
877 | unsigned long map_len = 0; | |
878 | int err; | |
879 | ||
880 | while (low < high) { | |
881 | mid = (low + high) / 2; | |
882 | offset = p + mid * item_size; | |
883 | ||
884 | if (!map_token || offset < map_start || | |
885 | (offset + sizeof(struct btrfs_disk_key)) > | |
886 | map_start + map_len) { | |
887 | if (map_token) { | |
888 | unmap_extent_buffer(eb, map_token, KM_USER0); | |
889 | map_token = NULL; | |
890 | } | |
891 | ||
892 | err = map_private_extent_buffer(eb, offset, | |
893 | sizeof(struct btrfs_disk_key), | |
894 | &map_token, &kaddr, | |
895 | &map_start, &map_len, KM_USER0); | |
896 | ||
897 | if (!err) { | |
898 | tmp = (struct btrfs_disk_key *)(kaddr + offset - | |
899 | map_start); | |
900 | } else { | |
901 | read_extent_buffer(eb, &unaligned, | |
902 | offset, sizeof(unaligned)); | |
903 | tmp = &unaligned; | |
904 | } | |
905 | ||
906 | } else { | |
907 | tmp = (struct btrfs_disk_key *)(kaddr + offset - | |
908 | map_start); | |
909 | } | |
910 | ret = comp_keys(tmp, key); | |
911 | ||
912 | if (ret < 0) | |
913 | low = mid + 1; | |
914 | else if (ret > 0) | |
915 | high = mid; | |
916 | else { | |
917 | *slot = mid; | |
918 | if (map_token) | |
919 | unmap_extent_buffer(eb, map_token, KM_USER0); | |
920 | return 0; | |
921 | } | |
922 | } | |
923 | *slot = low; | |
924 | if (map_token) | |
925 | unmap_extent_buffer(eb, map_token, KM_USER0); | |
926 | return 1; | |
927 | } | |
928 | ||
929 | /* | |
930 | * simple bin_search frontend that does the right thing for | |
931 | * leaves vs nodes | |
932 | */ | |
933 | static int bin_search(struct extent_buffer *eb, struct btrfs_key *key, | |
934 | int level, int *slot) | |
935 | { | |
936 | if (level == 0) { | |
937 | return generic_bin_search(eb, | |
938 | offsetof(struct btrfs_leaf, items), | |
939 | sizeof(struct btrfs_item), | |
940 | key, btrfs_header_nritems(eb), | |
941 | slot); | |
942 | } else { | |
943 | return generic_bin_search(eb, | |
944 | offsetof(struct btrfs_node, ptrs), | |
945 | sizeof(struct btrfs_key_ptr), | |
946 | key, btrfs_header_nritems(eb), | |
947 | slot); | |
948 | } | |
949 | return -1; | |
950 | } | |
951 | ||
952 | int btrfs_bin_search(struct extent_buffer *eb, struct btrfs_key *key, | |
953 | int level, int *slot) | |
954 | { | |
955 | return bin_search(eb, key, level, slot); | |
956 | } | |
957 | ||
958 | static void root_add_used(struct btrfs_root *root, u32 size) | |
959 | { | |
960 | spin_lock(&root->accounting_lock); | |
961 | btrfs_set_root_used(&root->root_item, | |
962 | btrfs_root_used(&root->root_item) + size); | |
963 | spin_unlock(&root->accounting_lock); | |
964 | } | |
965 | ||
966 | static void root_sub_used(struct btrfs_root *root, u32 size) | |
967 | { | |
968 | spin_lock(&root->accounting_lock); | |
969 | btrfs_set_root_used(&root->root_item, | |
970 | btrfs_root_used(&root->root_item) - size); | |
971 | spin_unlock(&root->accounting_lock); | |
972 | } | |
973 | ||
974 | /* given a node and slot number, this reads the blocks it points to. The | |
975 | * extent buffer is returned with a reference taken (but unlocked). | |
976 | * NULL is returned on error. | |
977 | */ | |
978 | static noinline struct extent_buffer *read_node_slot(struct btrfs_root *root, | |
979 | struct extent_buffer *parent, int slot) | |
980 | { | |
981 | int level = btrfs_header_level(parent); | |
982 | if (slot < 0) | |
983 | return NULL; | |
984 | if (slot >= btrfs_header_nritems(parent)) | |
985 | return NULL; | |
986 | ||
987 | BUG_ON(level == 0); | |
988 | ||
989 | return read_tree_block(root, btrfs_node_blockptr(parent, slot), | |
990 | btrfs_level_size(root, level - 1), | |
991 | btrfs_node_ptr_generation(parent, slot)); | |
992 | } | |
993 | ||
994 | /* | |
995 | * node level balancing, used to make sure nodes are in proper order for | |
996 | * item deletion. We balance from the top down, so we have to make sure | |
997 | * that a deletion won't leave an node completely empty later on. | |
998 | */ | |
999 | static noinline int balance_level(struct btrfs_trans_handle *trans, | |
1000 | struct btrfs_root *root, | |
1001 | struct btrfs_path *path, int level) | |
1002 | { | |
1003 | struct extent_buffer *right = NULL; | |
1004 | struct extent_buffer *mid; | |
1005 | struct extent_buffer *left = NULL; | |
1006 | struct extent_buffer *parent = NULL; | |
1007 | int ret = 0; | |
1008 | int wret; | |
1009 | int pslot; | |
1010 | int orig_slot = path->slots[level]; | |
1011 | int err_on_enospc = 0; | |
1012 | u64 orig_ptr; | |
1013 | ||
1014 | if (level == 0) | |
1015 | return 0; | |
1016 | ||
1017 | mid = path->nodes[level]; | |
1018 | ||
1019 | WARN_ON(!path->locks[level]); | |
1020 | WARN_ON(btrfs_header_generation(mid) != trans->transid); | |
1021 | ||
1022 | orig_ptr = btrfs_node_blockptr(mid, orig_slot); | |
1023 | ||
1024 | if (level < BTRFS_MAX_LEVEL - 1) | |
1025 | parent = path->nodes[level + 1]; | |
1026 | pslot = path->slots[level + 1]; | |
1027 | ||
1028 | /* | |
1029 | * deal with the case where there is only one pointer in the root | |
1030 | * by promoting the node below to a root | |
1031 | */ | |
1032 | if (!parent) { | |
1033 | struct extent_buffer *child; | |
1034 | ||
1035 | if (btrfs_header_nritems(mid) != 1) | |
1036 | return 0; | |
1037 | ||
1038 | /* promote the child to a root */ | |
1039 | child = read_node_slot(root, mid, 0); | |
1040 | BUG_ON(!child); | |
1041 | btrfs_tree_lock(child); | |
1042 | btrfs_set_lock_blocking(child); | |
1043 | ret = btrfs_cow_block(trans, root, child, mid, 0, &child); | |
1044 | if (ret) { | |
1045 | btrfs_tree_unlock(child); | |
1046 | free_extent_buffer(child); | |
1047 | goto enospc; | |
1048 | } | |
1049 | ||
1050 | spin_lock(&root->node_lock); | |
1051 | root->node = child; | |
1052 | spin_unlock(&root->node_lock); | |
1053 | ||
1054 | add_root_to_dirty_list(root); | |
1055 | btrfs_tree_unlock(child); | |
1056 | ||
1057 | path->locks[level] = 0; | |
1058 | path->nodes[level] = NULL; | |
1059 | clean_tree_block(trans, root, mid); | |
1060 | btrfs_tree_unlock(mid); | |
1061 | /* once for the path */ | |
1062 | free_extent_buffer(mid); | |
1063 | ||
1064 | root_sub_used(root, mid->len); | |
1065 | btrfs_free_tree_block(trans, root, mid, 0, 1); | |
1066 | /* once for the root ptr */ | |
1067 | free_extent_buffer(mid); | |
1068 | return 0; | |
1069 | } | |
1070 | if (btrfs_header_nritems(mid) > | |
1071 | BTRFS_NODEPTRS_PER_BLOCK(root) / 4) | |
1072 | return 0; | |
1073 | ||
1074 | if (btrfs_header_nritems(mid) < 2) | |
1075 | err_on_enospc = 1; | |
1076 | ||
1077 | left = read_node_slot(root, parent, pslot - 1); | |
1078 | if (left) { | |
1079 | btrfs_tree_lock(left); | |
1080 | btrfs_set_lock_blocking(left); | |
1081 | wret = btrfs_cow_block(trans, root, left, | |
1082 | parent, pslot - 1, &left); | |
1083 | if (wret) { | |
1084 | ret = wret; | |
1085 | goto enospc; | |
1086 | } | |
1087 | } | |
1088 | right = read_node_slot(root, parent, pslot + 1); | |
1089 | if (right) { | |
1090 | btrfs_tree_lock(right); | |
1091 | btrfs_set_lock_blocking(right); | |
1092 | wret = btrfs_cow_block(trans, root, right, | |
1093 | parent, pslot + 1, &right); | |
1094 | if (wret) { | |
1095 | ret = wret; | |
1096 | goto enospc; | |
1097 | } | |
1098 | } | |
1099 | ||
1100 | /* first, try to make some room in the middle buffer */ | |
1101 | if (left) { | |
1102 | orig_slot += btrfs_header_nritems(left); | |
1103 | wret = push_node_left(trans, root, left, mid, 1); | |
1104 | if (wret < 0) | |
1105 | ret = wret; | |
1106 | if (btrfs_header_nritems(mid) < 2) | |
1107 | err_on_enospc = 1; | |
1108 | } | |
1109 | ||
1110 | /* | |
1111 | * then try to empty the right most buffer into the middle | |
1112 | */ | |
1113 | if (right) { | |
1114 | wret = push_node_left(trans, root, mid, right, 1); | |
1115 | if (wret < 0 && wret != -ENOSPC) | |
1116 | ret = wret; | |
1117 | if (btrfs_header_nritems(right) == 0) { | |
1118 | clean_tree_block(trans, root, right); | |
1119 | btrfs_tree_unlock(right); | |
1120 | wret = del_ptr(trans, root, path, level + 1, pslot + | |
1121 | 1); | |
1122 | if (wret) | |
1123 | ret = wret; | |
1124 | root_sub_used(root, right->len); | |
1125 | btrfs_free_tree_block(trans, root, right, 0, 1); | |
1126 | free_extent_buffer(right); | |
1127 | right = NULL; | |
1128 | } else { | |
1129 | struct btrfs_disk_key right_key; | |
1130 | btrfs_node_key(right, &right_key, 0); | |
1131 | btrfs_set_node_key(parent, &right_key, pslot + 1); | |
1132 | btrfs_mark_buffer_dirty(parent); | |
1133 | } | |
1134 | } | |
1135 | if (btrfs_header_nritems(mid) == 1) { | |
1136 | /* | |
1137 | * we're not allowed to leave a node with one item in the | |
1138 | * tree during a delete. A deletion from lower in the tree | |
1139 | * could try to delete the only pointer in this node. | |
1140 | * So, pull some keys from the left. | |
1141 | * There has to be a left pointer at this point because | |
1142 | * otherwise we would have pulled some pointers from the | |
1143 | * right | |
1144 | */ | |
1145 | BUG_ON(!left); | |
1146 | wret = balance_node_right(trans, root, mid, left); | |
1147 | if (wret < 0) { | |
1148 | ret = wret; | |
1149 | goto enospc; | |
1150 | } | |
1151 | if (wret == 1) { | |
1152 | wret = push_node_left(trans, root, left, mid, 1); | |
1153 | if (wret < 0) | |
1154 | ret = wret; | |
1155 | } | |
1156 | BUG_ON(wret == 1); | |
1157 | } | |
1158 | if (btrfs_header_nritems(mid) == 0) { | |
1159 | clean_tree_block(trans, root, mid); | |
1160 | btrfs_tree_unlock(mid); | |
1161 | wret = del_ptr(trans, root, path, level + 1, pslot); | |
1162 | if (wret) | |
1163 | ret = wret; | |
1164 | root_sub_used(root, mid->len); | |
1165 | btrfs_free_tree_block(trans, root, mid, 0, 1); | |
1166 | free_extent_buffer(mid); | |
1167 | mid = NULL; | |
1168 | } else { | |
1169 | /* update the parent key to reflect our changes */ | |
1170 | struct btrfs_disk_key mid_key; | |
1171 | btrfs_node_key(mid, &mid_key, 0); | |
1172 | btrfs_set_node_key(parent, &mid_key, pslot); | |
1173 | btrfs_mark_buffer_dirty(parent); | |
1174 | } | |
1175 | ||
1176 | /* update the path */ | |
1177 | if (left) { | |
1178 | if (btrfs_header_nritems(left) > orig_slot) { | |
1179 | extent_buffer_get(left); | |
1180 | /* left was locked after cow */ | |
1181 | path->nodes[level] = left; | |
1182 | path->slots[level + 1] -= 1; | |
1183 | path->slots[level] = orig_slot; | |
1184 | if (mid) { | |
1185 | btrfs_tree_unlock(mid); | |
1186 | free_extent_buffer(mid); | |
1187 | } | |
1188 | } else { | |
1189 | orig_slot -= btrfs_header_nritems(left); | |
1190 | path->slots[level] = orig_slot; | |
1191 | } | |
1192 | } | |
1193 | /* double check we haven't messed things up */ | |
1194 | check_block(root, path, level); | |
1195 | if (orig_ptr != | |
1196 | btrfs_node_blockptr(path->nodes[level], path->slots[level])) | |
1197 | BUG(); | |
1198 | enospc: | |
1199 | if (right) { | |
1200 | btrfs_tree_unlock(right); | |
1201 | free_extent_buffer(right); | |
1202 | } | |
1203 | if (left) { | |
1204 | if (path->nodes[level] != left) | |
1205 | btrfs_tree_unlock(left); | |
1206 | free_extent_buffer(left); | |
1207 | } | |
1208 | return ret; | |
1209 | } | |
1210 | ||
1211 | /* Node balancing for insertion. Here we only split or push nodes around | |
1212 | * when they are completely full. This is also done top down, so we | |
1213 | * have to be pessimistic. | |
1214 | */ | |
1215 | static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans, | |
1216 | struct btrfs_root *root, | |
1217 | struct btrfs_path *path, int level) | |
1218 | { | |
1219 | struct extent_buffer *right = NULL; | |
1220 | struct extent_buffer *mid; | |
1221 | struct extent_buffer *left = NULL; | |
1222 | struct extent_buffer *parent = NULL; | |
1223 | int ret = 0; | |
1224 | int wret; | |
1225 | int pslot; | |
1226 | int orig_slot = path->slots[level]; | |
1227 | u64 orig_ptr; | |
1228 | ||
1229 | if (level == 0) | |
1230 | return 1; | |
1231 | ||
1232 | mid = path->nodes[level]; | |
1233 | WARN_ON(btrfs_header_generation(mid) != trans->transid); | |
1234 | orig_ptr = btrfs_node_blockptr(mid, orig_slot); | |
1235 | ||
1236 | if (level < BTRFS_MAX_LEVEL - 1) | |
1237 | parent = path->nodes[level + 1]; | |
1238 | pslot = path->slots[level + 1]; | |
1239 | ||
1240 | if (!parent) | |
1241 | return 1; | |
1242 | ||
1243 | left = read_node_slot(root, parent, pslot - 1); | |
1244 | ||
1245 | /* first, try to make some room in the middle buffer */ | |
1246 | if (left) { | |
1247 | u32 left_nr; | |
1248 | ||
1249 | btrfs_tree_lock(left); | |
1250 | btrfs_set_lock_blocking(left); | |
1251 | ||
1252 | left_nr = btrfs_header_nritems(left); | |
1253 | if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) { | |
1254 | wret = 1; | |
1255 | } else { | |
1256 | ret = btrfs_cow_block(trans, root, left, parent, | |
1257 | pslot - 1, &left); | |
1258 | if (ret) | |
1259 | wret = 1; | |
1260 | else { | |
1261 | wret = push_node_left(trans, root, | |
1262 | left, mid, 0); | |
1263 | } | |
1264 | } | |
1265 | if (wret < 0) | |
1266 | ret = wret; | |
1267 | if (wret == 0) { | |
1268 | struct btrfs_disk_key disk_key; | |
1269 | orig_slot += left_nr; | |
1270 | btrfs_node_key(mid, &disk_key, 0); | |
1271 | btrfs_set_node_key(parent, &disk_key, pslot); | |
1272 | btrfs_mark_buffer_dirty(parent); | |
1273 | if (btrfs_header_nritems(left) > orig_slot) { | |
1274 | path->nodes[level] = left; | |
1275 | path->slots[level + 1] -= 1; | |
1276 | path->slots[level] = orig_slot; | |
1277 | btrfs_tree_unlock(mid); | |
1278 | free_extent_buffer(mid); | |
1279 | } else { | |
1280 | orig_slot -= | |
1281 | btrfs_header_nritems(left); | |
1282 | path->slots[level] = orig_slot; | |
1283 | btrfs_tree_unlock(left); | |
1284 | free_extent_buffer(left); | |
1285 | } | |
1286 | return 0; | |
1287 | } | |
1288 | btrfs_tree_unlock(left); | |
1289 | free_extent_buffer(left); | |
1290 | } | |
1291 | right = read_node_slot(root, parent, pslot + 1); | |
1292 | ||
1293 | /* | |
1294 | * then try to empty the right most buffer into the middle | |
1295 | */ | |
1296 | if (right) { | |
1297 | u32 right_nr; | |
1298 | ||
1299 | btrfs_tree_lock(right); | |
1300 | btrfs_set_lock_blocking(right); | |
1301 | ||
1302 | right_nr = btrfs_header_nritems(right); | |
1303 | if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) { | |
1304 | wret = 1; | |
1305 | } else { | |
1306 | ret = btrfs_cow_block(trans, root, right, | |
1307 | parent, pslot + 1, | |
1308 | &right); | |
1309 | if (ret) | |
1310 | wret = 1; | |
1311 | else { | |
1312 | wret = balance_node_right(trans, root, | |
1313 | right, mid); | |
1314 | } | |
1315 | } | |
1316 | if (wret < 0) | |
1317 | ret = wret; | |
1318 | if (wret == 0) { | |
1319 | struct btrfs_disk_key disk_key; | |
1320 | ||
1321 | btrfs_node_key(right, &disk_key, 0); | |
1322 | btrfs_set_node_key(parent, &disk_key, pslot + 1); | |
1323 | btrfs_mark_buffer_dirty(parent); | |
1324 | ||
1325 | if (btrfs_header_nritems(mid) <= orig_slot) { | |
1326 | path->nodes[level] = right; | |
1327 | path->slots[level + 1] += 1; | |
1328 | path->slots[level] = orig_slot - | |
1329 | btrfs_header_nritems(mid); | |
1330 | btrfs_tree_unlock(mid); | |
1331 | free_extent_buffer(mid); | |
1332 | } else { | |
1333 | btrfs_tree_unlock(right); | |
1334 | free_extent_buffer(right); | |
1335 | } | |
1336 | return 0; | |
1337 | } | |
1338 | btrfs_tree_unlock(right); | |
1339 | free_extent_buffer(right); | |
1340 | } | |
1341 | return 1; | |
1342 | } | |
1343 | ||
1344 | /* | |
1345 | * readahead one full node of leaves, finding things that are close | |
1346 | * to the block in 'slot', and triggering ra on them. | |
1347 | */ | |
1348 | static void reada_for_search(struct btrfs_root *root, | |
1349 | struct btrfs_path *path, | |
1350 | int level, int slot, u64 objectid) | |
1351 | { | |
1352 | struct extent_buffer *node; | |
1353 | struct btrfs_disk_key disk_key; | |
1354 | u32 nritems; | |
1355 | u64 search; | |
1356 | u64 target; | |
1357 | u64 nread = 0; | |
1358 | int direction = path->reada; | |
1359 | struct extent_buffer *eb; | |
1360 | u32 nr; | |
1361 | u32 blocksize; | |
1362 | u32 nscan = 0; | |
1363 | ||
1364 | if (level != 1) | |
1365 | return; | |
1366 | ||
1367 | if (!path->nodes[level]) | |
1368 | return; | |
1369 | ||
1370 | node = path->nodes[level]; | |
1371 | ||
1372 | search = btrfs_node_blockptr(node, slot); | |
1373 | blocksize = btrfs_level_size(root, level - 1); | |
1374 | eb = btrfs_find_tree_block(root, search, blocksize); | |
1375 | if (eb) { | |
1376 | free_extent_buffer(eb); | |
1377 | return; | |
1378 | } | |
1379 | ||
1380 | target = search; | |
1381 | ||
1382 | nritems = btrfs_header_nritems(node); | |
1383 | nr = slot; | |
1384 | while (1) { | |
1385 | if (direction < 0) { | |
1386 | if (nr == 0) | |
1387 | break; | |
1388 | nr--; | |
1389 | } else if (direction > 0) { | |
1390 | nr++; | |
1391 | if (nr >= nritems) | |
1392 | break; | |
1393 | } | |
1394 | if (path->reada < 0 && objectid) { | |
1395 | btrfs_node_key(node, &disk_key, nr); | |
1396 | if (btrfs_disk_key_objectid(&disk_key) != objectid) | |
1397 | break; | |
1398 | } | |
1399 | search = btrfs_node_blockptr(node, nr); | |
1400 | if ((search <= target && target - search <= 65536) || | |
1401 | (search > target && search - target <= 65536)) { | |
1402 | readahead_tree_block(root, search, blocksize, | |
1403 | btrfs_node_ptr_generation(node, nr)); | |
1404 | nread += blocksize; | |
1405 | } | |
1406 | nscan++; | |
1407 | if ((nread > 65536 || nscan > 32)) | |
1408 | break; | |
1409 | } | |
1410 | } | |
1411 | ||
1412 | /* | |
1413 | * returns -EAGAIN if it had to drop the path, or zero if everything was in | |
1414 | * cache | |
1415 | */ | |
1416 | static noinline int reada_for_balance(struct btrfs_root *root, | |
1417 | struct btrfs_path *path, int level) | |
1418 | { | |
1419 | int slot; | |
1420 | int nritems; | |
1421 | struct extent_buffer *parent; | |
1422 | struct extent_buffer *eb; | |
1423 | u64 gen; | |
1424 | u64 block1 = 0; | |
1425 | u64 block2 = 0; | |
1426 | int ret = 0; | |
1427 | int blocksize; | |
1428 | ||
1429 | parent = path->nodes[level + 1]; | |
1430 | if (!parent) | |
1431 | return 0; | |
1432 | ||
1433 | nritems = btrfs_header_nritems(parent); | |
1434 | slot = path->slots[level + 1]; | |
1435 | blocksize = btrfs_level_size(root, level); | |
1436 | ||
1437 | if (slot > 0) { | |
1438 | block1 = btrfs_node_blockptr(parent, slot - 1); | |
1439 | gen = btrfs_node_ptr_generation(parent, slot - 1); | |
1440 | eb = btrfs_find_tree_block(root, block1, blocksize); | |
1441 | if (eb && btrfs_buffer_uptodate(eb, gen)) | |
1442 | block1 = 0; | |
1443 | free_extent_buffer(eb); | |
1444 | } | |
1445 | if (slot + 1 < nritems) { | |
1446 | block2 = btrfs_node_blockptr(parent, slot + 1); | |
1447 | gen = btrfs_node_ptr_generation(parent, slot + 1); | |
1448 | eb = btrfs_find_tree_block(root, block2, blocksize); | |
1449 | if (eb && btrfs_buffer_uptodate(eb, gen)) | |
1450 | block2 = 0; | |
1451 | free_extent_buffer(eb); | |
1452 | } | |
1453 | if (block1 || block2) { | |
1454 | ret = -EAGAIN; | |
1455 | ||
1456 | /* release the whole path */ | |
1457 | btrfs_release_path(root, path); | |
1458 | ||
1459 | /* read the blocks */ | |
1460 | if (block1) | |
1461 | readahead_tree_block(root, block1, blocksize, 0); | |
1462 | if (block2) | |
1463 | readahead_tree_block(root, block2, blocksize, 0); | |
1464 | ||
1465 | if (block1) { | |
1466 | eb = read_tree_block(root, block1, blocksize, 0); | |
1467 | free_extent_buffer(eb); | |
1468 | } | |
1469 | if (block2) { | |
1470 | eb = read_tree_block(root, block2, blocksize, 0); | |
1471 | free_extent_buffer(eb); | |
1472 | } | |
1473 | } | |
1474 | return ret; | |
1475 | } | |
1476 | ||
1477 | ||
1478 | /* | |
1479 | * when we walk down the tree, it is usually safe to unlock the higher layers | |
1480 | * in the tree. The exceptions are when our path goes through slot 0, because | |
1481 | * operations on the tree might require changing key pointers higher up in the | |
1482 | * tree. | |
1483 | * | |
1484 | * callers might also have set path->keep_locks, which tells this code to keep | |
1485 | * the lock if the path points to the last slot in the block. This is part of | |
1486 | * walking through the tree, and selecting the next slot in the higher block. | |
1487 | * | |
1488 | * lowest_unlock sets the lowest level in the tree we're allowed to unlock. so | |
1489 | * if lowest_unlock is 1, level 0 won't be unlocked | |
1490 | */ | |
1491 | static noinline void unlock_up(struct btrfs_path *path, int level, | |
1492 | int lowest_unlock) | |
1493 | { | |
1494 | int i; | |
1495 | int skip_level = level; | |
1496 | int no_skips = 0; | |
1497 | struct extent_buffer *t; | |
1498 | ||
1499 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { | |
1500 | if (!path->nodes[i]) | |
1501 | break; | |
1502 | if (!path->locks[i]) | |
1503 | break; | |
1504 | if (!no_skips && path->slots[i] == 0) { | |
1505 | skip_level = i + 1; | |
1506 | continue; | |
1507 | } | |
1508 | if (!no_skips && path->keep_locks) { | |
1509 | u32 nritems; | |
1510 | t = path->nodes[i]; | |
1511 | nritems = btrfs_header_nritems(t); | |
1512 | if (nritems < 1 || path->slots[i] >= nritems - 1) { | |
1513 | skip_level = i + 1; | |
1514 | continue; | |
1515 | } | |
1516 | } | |
1517 | if (skip_level < i && i >= lowest_unlock) | |
1518 | no_skips = 1; | |
1519 | ||
1520 | t = path->nodes[i]; | |
1521 | if (i >= lowest_unlock && i > skip_level && path->locks[i]) { | |
1522 | btrfs_tree_unlock(t); | |
1523 | path->locks[i] = 0; | |
1524 | } | |
1525 | } | |
1526 | } | |
1527 | ||
1528 | /* | |
1529 | * This releases any locks held in the path starting at level and | |
1530 | * going all the way up to the root. | |
1531 | * | |
1532 | * btrfs_search_slot will keep the lock held on higher nodes in a few | |
1533 | * corner cases, such as COW of the block at slot zero in the node. This | |
1534 | * ignores those rules, and it should only be called when there are no | |
1535 | * more updates to be done higher up in the tree. | |
1536 | */ | |
1537 | noinline void btrfs_unlock_up_safe(struct btrfs_path *path, int level) | |
1538 | { | |
1539 | int i; | |
1540 | ||
1541 | if (path->keep_locks) | |
1542 | return; | |
1543 | ||
1544 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { | |
1545 | if (!path->nodes[i]) | |
1546 | continue; | |
1547 | if (!path->locks[i]) | |
1548 | continue; | |
1549 | btrfs_tree_unlock(path->nodes[i]); | |
1550 | path->locks[i] = 0; | |
1551 | } | |
1552 | } | |
1553 | ||
1554 | /* | |
1555 | * helper function for btrfs_search_slot. The goal is to find a block | |
1556 | * in cache without setting the path to blocking. If we find the block | |
1557 | * we return zero and the path is unchanged. | |
1558 | * | |
1559 | * If we can't find the block, we set the path blocking and do some | |
1560 | * reada. -EAGAIN is returned and the search must be repeated. | |
1561 | */ | |
1562 | static int | |
1563 | read_block_for_search(struct btrfs_trans_handle *trans, | |
1564 | struct btrfs_root *root, struct btrfs_path *p, | |
1565 | struct extent_buffer **eb_ret, int level, int slot, | |
1566 | struct btrfs_key *key) | |
1567 | { | |
1568 | u64 blocknr; | |
1569 | u64 gen; | |
1570 | u32 blocksize; | |
1571 | struct extent_buffer *b = *eb_ret; | |
1572 | struct extent_buffer *tmp; | |
1573 | int ret; | |
1574 | ||
1575 | blocknr = btrfs_node_blockptr(b, slot); | |
1576 | gen = btrfs_node_ptr_generation(b, slot); | |
1577 | blocksize = btrfs_level_size(root, level - 1); | |
1578 | ||
1579 | tmp = btrfs_find_tree_block(root, blocknr, blocksize); | |
1580 | if (tmp && btrfs_buffer_uptodate(tmp, gen)) { | |
1581 | /* | |
1582 | * we found an up to date block without sleeping, return | |
1583 | * right away | |
1584 | */ | |
1585 | *eb_ret = tmp; | |
1586 | return 0; | |
1587 | } | |
1588 | ||
1589 | /* | |
1590 | * reduce lock contention at high levels | |
1591 | * of the btree by dropping locks before | |
1592 | * we read. Don't release the lock on the current | |
1593 | * level because we need to walk this node to figure | |
1594 | * out which blocks to read. | |
1595 | */ | |
1596 | btrfs_unlock_up_safe(p, level + 1); | |
1597 | btrfs_set_path_blocking(p); | |
1598 | ||
1599 | if (tmp) | |
1600 | free_extent_buffer(tmp); | |
1601 | if (p->reada) | |
1602 | reada_for_search(root, p, level, slot, key->objectid); | |
1603 | ||
1604 | btrfs_release_path(NULL, p); | |
1605 | ||
1606 | ret = -EAGAIN; | |
1607 | tmp = read_tree_block(root, blocknr, blocksize, 0); | |
1608 | if (tmp) { | |
1609 | /* | |
1610 | * If the read above didn't mark this buffer up to date, | |
1611 | * it will never end up being up to date. Set ret to EIO now | |
1612 | * and give up so that our caller doesn't loop forever | |
1613 | * on our EAGAINs. | |
1614 | */ | |
1615 | if (!btrfs_buffer_uptodate(tmp, 0)) | |
1616 | ret = -EIO; | |
1617 | free_extent_buffer(tmp); | |
1618 | } | |
1619 | return ret; | |
1620 | } | |
1621 | ||
1622 | /* | |
1623 | * helper function for btrfs_search_slot. This does all of the checks | |
1624 | * for node-level blocks and does any balancing required based on | |
1625 | * the ins_len. | |
1626 | * | |
1627 | * If no extra work was required, zero is returned. If we had to | |
1628 | * drop the path, -EAGAIN is returned and btrfs_search_slot must | |
1629 | * start over | |
1630 | */ | |
1631 | static int | |
1632 | setup_nodes_for_search(struct btrfs_trans_handle *trans, | |
1633 | struct btrfs_root *root, struct btrfs_path *p, | |
1634 | struct extent_buffer *b, int level, int ins_len) | |
1635 | { | |
1636 | int ret; | |
1637 | if ((p->search_for_split || ins_len > 0) && btrfs_header_nritems(b) >= | |
1638 | BTRFS_NODEPTRS_PER_BLOCK(root) - 3) { | |
1639 | int sret; | |
1640 | ||
1641 | sret = reada_for_balance(root, p, level); | |
1642 | if (sret) | |
1643 | goto again; | |
1644 | ||
1645 | btrfs_set_path_blocking(p); | |
1646 | sret = split_node(trans, root, p, level); | |
1647 | btrfs_clear_path_blocking(p, NULL); | |
1648 | ||
1649 | BUG_ON(sret > 0); | |
1650 | if (sret) { | |
1651 | ret = sret; | |
1652 | goto done; | |
1653 | } | |
1654 | b = p->nodes[level]; | |
1655 | } else if (ins_len < 0 && btrfs_header_nritems(b) < | |
1656 | BTRFS_NODEPTRS_PER_BLOCK(root) / 2) { | |
1657 | int sret; | |
1658 | ||
1659 | sret = reada_for_balance(root, p, level); | |
1660 | if (sret) | |
1661 | goto again; | |
1662 | ||
1663 | btrfs_set_path_blocking(p); | |
1664 | sret = balance_level(trans, root, p, level); | |
1665 | btrfs_clear_path_blocking(p, NULL); | |
1666 | ||
1667 | if (sret) { | |
1668 | ret = sret; | |
1669 | goto done; | |
1670 | } | |
1671 | b = p->nodes[level]; | |
1672 | if (!b) { | |
1673 | btrfs_release_path(NULL, p); | |
1674 | goto again; | |
1675 | } | |
1676 | BUG_ON(btrfs_header_nritems(b) == 1); | |
1677 | } | |
1678 | return 0; | |
1679 | ||
1680 | again: | |
1681 | ret = -EAGAIN; | |
1682 | done: | |
1683 | return ret; | |
1684 | } | |
1685 | ||
1686 | /* | |
1687 | * look for key in the tree. path is filled in with nodes along the way | |
1688 | * if key is found, we return zero and you can find the item in the leaf | |
1689 | * level of the path (level 0) | |
1690 | * | |
1691 | * If the key isn't found, the path points to the slot where it should | |
1692 | * be inserted, and 1 is returned. If there are other errors during the | |
1693 | * search a negative error number is returned. | |
1694 | * | |
1695 | * if ins_len > 0, nodes and leaves will be split as we walk down the | |
1696 | * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if | |
1697 | * possible) | |
1698 | */ | |
1699 | int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root | |
1700 | *root, struct btrfs_key *key, struct btrfs_path *p, int | |
1701 | ins_len, int cow) | |
1702 | { | |
1703 | struct extent_buffer *b; | |
1704 | int slot; | |
1705 | int ret; | |
1706 | int err; | |
1707 | int level; | |
1708 | int lowest_unlock = 1; | |
1709 | u8 lowest_level = 0; | |
1710 | ||
1711 | lowest_level = p->lowest_level; | |
1712 | WARN_ON(lowest_level && ins_len > 0); | |
1713 | WARN_ON(p->nodes[0] != NULL); | |
1714 | ||
1715 | if (ins_len < 0) | |
1716 | lowest_unlock = 2; | |
1717 | ||
1718 | again: | |
1719 | if (p->search_commit_root) { | |
1720 | b = root->commit_root; | |
1721 | extent_buffer_get(b); | |
1722 | if (!p->skip_locking) | |
1723 | btrfs_tree_lock(b); | |
1724 | } else { | |
1725 | if (p->skip_locking) | |
1726 | b = btrfs_root_node(root); | |
1727 | else | |
1728 | b = btrfs_lock_root_node(root); | |
1729 | } | |
1730 | ||
1731 | while (b) { | |
1732 | level = btrfs_header_level(b); | |
1733 | ||
1734 | /* | |
1735 | * setup the path here so we can release it under lock | |
1736 | * contention with the cow code | |
1737 | */ | |
1738 | p->nodes[level] = b; | |
1739 | if (!p->skip_locking) | |
1740 | p->locks[level] = 1; | |
1741 | ||
1742 | if (cow) { | |
1743 | /* | |
1744 | * if we don't really need to cow this block | |
1745 | * then we don't want to set the path blocking, | |
1746 | * so we test it here | |
1747 | */ | |
1748 | if (!should_cow_block(trans, root, b)) | |
1749 | goto cow_done; | |
1750 | ||
1751 | btrfs_set_path_blocking(p); | |
1752 | ||
1753 | err = btrfs_cow_block(trans, root, b, | |
1754 | p->nodes[level + 1], | |
1755 | p->slots[level + 1], &b); | |
1756 | if (err) { | |
1757 | ret = err; | |
1758 | goto done; | |
1759 | } | |
1760 | } | |
1761 | cow_done: | |
1762 | BUG_ON(!cow && ins_len); | |
1763 | if (level != btrfs_header_level(b)) | |
1764 | WARN_ON(1); | |
1765 | level = btrfs_header_level(b); | |
1766 | ||
1767 | p->nodes[level] = b; | |
1768 | if (!p->skip_locking) | |
1769 | p->locks[level] = 1; | |
1770 | ||
1771 | btrfs_clear_path_blocking(p, NULL); | |
1772 | ||
1773 | /* | |
1774 | * we have a lock on b and as long as we aren't changing | |
1775 | * the tree, there is no way to for the items in b to change. | |
1776 | * It is safe to drop the lock on our parent before we | |
1777 | * go through the expensive btree search on b. | |
1778 | * | |
1779 | * If cow is true, then we might be changing slot zero, | |
1780 | * which may require changing the parent. So, we can't | |
1781 | * drop the lock until after we know which slot we're | |
1782 | * operating on. | |
1783 | */ | |
1784 | if (!cow) | |
1785 | btrfs_unlock_up_safe(p, level + 1); | |
1786 | ||
1787 | ret = check_block(root, p, level); | |
1788 | if (ret) { | |
1789 | ret = -1; | |
1790 | goto done; | |
1791 | } | |
1792 | ||
1793 | ret = bin_search(b, key, level, &slot); | |
1794 | ||
1795 | if (level != 0) { | |
1796 | int dec = 0; | |
1797 | if (ret && slot > 0) { | |
1798 | dec = 1; | |
1799 | slot -= 1; | |
1800 | } | |
1801 | p->slots[level] = slot; | |
1802 | err = setup_nodes_for_search(trans, root, p, b, level, | |
1803 | ins_len); | |
1804 | if (err == -EAGAIN) | |
1805 | goto again; | |
1806 | if (err) { | |
1807 | ret = err; | |
1808 | goto done; | |
1809 | } | |
1810 | b = p->nodes[level]; | |
1811 | slot = p->slots[level]; | |
1812 | ||
1813 | unlock_up(p, level, lowest_unlock); | |
1814 | ||
1815 | if (level == lowest_level) { | |
1816 | if (dec) | |
1817 | p->slots[level]++; | |
1818 | goto done; | |
1819 | } | |
1820 | ||
1821 | err = read_block_for_search(trans, root, p, | |
1822 | &b, level, slot, key); | |
1823 | if (err == -EAGAIN) | |
1824 | goto again; | |
1825 | if (err) { | |
1826 | ret = err; | |
1827 | goto done; | |
1828 | } | |
1829 | ||
1830 | if (!p->skip_locking) { | |
1831 | btrfs_clear_path_blocking(p, NULL); | |
1832 | err = btrfs_try_spin_lock(b); | |
1833 | ||
1834 | if (!err) { | |
1835 | btrfs_set_path_blocking(p); | |
1836 | btrfs_tree_lock(b); | |
1837 | btrfs_clear_path_blocking(p, b); | |
1838 | } | |
1839 | } | |
1840 | } else { | |
1841 | p->slots[level] = slot; | |
1842 | if (ins_len > 0 && | |
1843 | btrfs_leaf_free_space(root, b) < ins_len) { | |
1844 | btrfs_set_path_blocking(p); | |
1845 | err = split_leaf(trans, root, key, | |
1846 | p, ins_len, ret == 0); | |
1847 | btrfs_clear_path_blocking(p, NULL); | |
1848 | ||
1849 | BUG_ON(err > 0); | |
1850 | if (err) { | |
1851 | ret = err; | |
1852 | goto done; | |
1853 | } | |
1854 | } | |
1855 | if (!p->search_for_split) | |
1856 | unlock_up(p, level, lowest_unlock); | |
1857 | goto done; | |
1858 | } | |
1859 | } | |
1860 | ret = 1; | |
1861 | done: | |
1862 | /* | |
1863 | * we don't really know what they plan on doing with the path | |
1864 | * from here on, so for now just mark it as blocking | |
1865 | */ | |
1866 | if (!p->leave_spinning) | |
1867 | btrfs_set_path_blocking(p); | |
1868 | if (ret < 0) | |
1869 | btrfs_release_path(root, p); | |
1870 | return ret; | |
1871 | } | |
1872 | ||
1873 | /* | |
1874 | * adjust the pointers going up the tree, starting at level | |
1875 | * making sure the right key of each node is points to 'key'. | |
1876 | * This is used after shifting pointers to the left, so it stops | |
1877 | * fixing up pointers when a given leaf/node is not in slot 0 of the | |
1878 | * higher levels | |
1879 | * | |
1880 | * If this fails to write a tree block, it returns -1, but continues | |
1881 | * fixing up the blocks in ram so the tree is consistent. | |
1882 | */ | |
1883 | static int fixup_low_keys(struct btrfs_trans_handle *trans, | |
1884 | struct btrfs_root *root, struct btrfs_path *path, | |
1885 | struct btrfs_disk_key *key, int level) | |
1886 | { | |
1887 | int i; | |
1888 | int ret = 0; | |
1889 | struct extent_buffer *t; | |
1890 | ||
1891 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { | |
1892 | int tslot = path->slots[i]; | |
1893 | if (!path->nodes[i]) | |
1894 | break; | |
1895 | t = path->nodes[i]; | |
1896 | btrfs_set_node_key(t, key, tslot); | |
1897 | btrfs_mark_buffer_dirty(path->nodes[i]); | |
1898 | if (tslot != 0) | |
1899 | break; | |
1900 | } | |
1901 | return ret; | |
1902 | } | |
1903 | ||
1904 | /* | |
1905 | * update item key. | |
1906 | * | |
1907 | * This function isn't completely safe. It's the caller's responsibility | |
1908 | * that the new key won't break the order | |
1909 | */ | |
1910 | int btrfs_set_item_key_safe(struct btrfs_trans_handle *trans, | |
1911 | struct btrfs_root *root, struct btrfs_path *path, | |
1912 | struct btrfs_key *new_key) | |
1913 | { | |
1914 | struct btrfs_disk_key disk_key; | |
1915 | struct extent_buffer *eb; | |
1916 | int slot; | |
1917 | ||
1918 | eb = path->nodes[0]; | |
1919 | slot = path->slots[0]; | |
1920 | if (slot > 0) { | |
1921 | btrfs_item_key(eb, &disk_key, slot - 1); | |
1922 | if (comp_keys(&disk_key, new_key) >= 0) | |
1923 | return -1; | |
1924 | } | |
1925 | if (slot < btrfs_header_nritems(eb) - 1) { | |
1926 | btrfs_item_key(eb, &disk_key, slot + 1); | |
1927 | if (comp_keys(&disk_key, new_key) <= 0) | |
1928 | return -1; | |
1929 | } | |
1930 | ||
1931 | btrfs_cpu_key_to_disk(&disk_key, new_key); | |
1932 | btrfs_set_item_key(eb, &disk_key, slot); | |
1933 | btrfs_mark_buffer_dirty(eb); | |
1934 | if (slot == 0) | |
1935 | fixup_low_keys(trans, root, path, &disk_key, 1); | |
1936 | return 0; | |
1937 | } | |
1938 | ||
1939 | /* | |
1940 | * try to push data from one node into the next node left in the | |
1941 | * tree. | |
1942 | * | |
1943 | * returns 0 if some ptrs were pushed left, < 0 if there was some horrible | |
1944 | * error, and > 0 if there was no room in the left hand block. | |
1945 | */ | |
1946 | static int push_node_left(struct btrfs_trans_handle *trans, | |
1947 | struct btrfs_root *root, struct extent_buffer *dst, | |
1948 | struct extent_buffer *src, int empty) | |
1949 | { | |
1950 | int push_items = 0; | |
1951 | int src_nritems; | |
1952 | int dst_nritems; | |
1953 | int ret = 0; | |
1954 | ||
1955 | src_nritems = btrfs_header_nritems(src); | |
1956 | dst_nritems = btrfs_header_nritems(dst); | |
1957 | push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems; | |
1958 | WARN_ON(btrfs_header_generation(src) != trans->transid); | |
1959 | WARN_ON(btrfs_header_generation(dst) != trans->transid); | |
1960 | ||
1961 | if (!empty && src_nritems <= 8) | |
1962 | return 1; | |
1963 | ||
1964 | if (push_items <= 0) | |
1965 | return 1; | |
1966 | ||
1967 | if (empty) { | |
1968 | push_items = min(src_nritems, push_items); | |
1969 | if (push_items < src_nritems) { | |
1970 | /* leave at least 8 pointers in the node if | |
1971 | * we aren't going to empty it | |
1972 | */ | |
1973 | if (src_nritems - push_items < 8) { | |
1974 | if (push_items <= 8) | |
1975 | return 1; | |
1976 | push_items -= 8; | |
1977 | } | |
1978 | } | |
1979 | } else | |
1980 | push_items = min(src_nritems - 8, push_items); | |
1981 | ||
1982 | copy_extent_buffer(dst, src, | |
1983 | btrfs_node_key_ptr_offset(dst_nritems), | |
1984 | btrfs_node_key_ptr_offset(0), | |
1985 | push_items * sizeof(struct btrfs_key_ptr)); | |
1986 | ||
1987 | if (push_items < src_nritems) { | |
1988 | memmove_extent_buffer(src, btrfs_node_key_ptr_offset(0), | |
1989 | btrfs_node_key_ptr_offset(push_items), | |
1990 | (src_nritems - push_items) * | |
1991 | sizeof(struct btrfs_key_ptr)); | |
1992 | } | |
1993 | btrfs_set_header_nritems(src, src_nritems - push_items); | |
1994 | btrfs_set_header_nritems(dst, dst_nritems + push_items); | |
1995 | btrfs_mark_buffer_dirty(src); | |
1996 | btrfs_mark_buffer_dirty(dst); | |
1997 | ||
1998 | return ret; | |
1999 | } | |
2000 | ||
2001 | /* | |
2002 | * try to push data from one node into the next node right in the | |
2003 | * tree. | |
2004 | * | |
2005 | * returns 0 if some ptrs were pushed, < 0 if there was some horrible | |
2006 | * error, and > 0 if there was no room in the right hand block. | |
2007 | * | |
2008 | * this will only push up to 1/2 the contents of the left node over | |
2009 | */ | |
2010 | static int balance_node_right(struct btrfs_trans_handle *trans, | |
2011 | struct btrfs_root *root, | |
2012 | struct extent_buffer *dst, | |
2013 | struct extent_buffer *src) | |
2014 | { | |
2015 | int push_items = 0; | |
2016 | int max_push; | |
2017 | int src_nritems; | |
2018 | int dst_nritems; | |
2019 | int ret = 0; | |
2020 | ||
2021 | WARN_ON(btrfs_header_generation(src) != trans->transid); | |
2022 | WARN_ON(btrfs_header_generation(dst) != trans->transid); | |
2023 | ||
2024 | src_nritems = btrfs_header_nritems(src); | |
2025 | dst_nritems = btrfs_header_nritems(dst); | |
2026 | push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems; | |
2027 | if (push_items <= 0) | |
2028 | return 1; | |
2029 | ||
2030 | if (src_nritems < 4) | |
2031 | return 1; | |
2032 | ||
2033 | max_push = src_nritems / 2 + 1; | |
2034 | /* don't try to empty the node */ | |
2035 | if (max_push >= src_nritems) | |
2036 | return 1; | |
2037 | ||
2038 | if (max_push < push_items) | |
2039 | push_items = max_push; | |
2040 | ||
2041 | memmove_extent_buffer(dst, btrfs_node_key_ptr_offset(push_items), | |
2042 | btrfs_node_key_ptr_offset(0), | |
2043 | (dst_nritems) * | |
2044 | sizeof(struct btrfs_key_ptr)); | |
2045 | ||
2046 | copy_extent_buffer(dst, src, | |
2047 | btrfs_node_key_ptr_offset(0), | |
2048 | btrfs_node_key_ptr_offset(src_nritems - push_items), | |
2049 | push_items * sizeof(struct btrfs_key_ptr)); | |
2050 | ||
2051 | btrfs_set_header_nritems(src, src_nritems - push_items); | |
2052 | btrfs_set_header_nritems(dst, dst_nritems + push_items); | |
2053 | ||
2054 | btrfs_mark_buffer_dirty(src); | |
2055 | btrfs_mark_buffer_dirty(dst); | |
2056 | ||
2057 | return ret; | |
2058 | } | |
2059 | ||
2060 | /* | |
2061 | * helper function to insert a new root level in the tree. | |
2062 | * A new node is allocated, and a single item is inserted to | |
2063 | * point to the existing root | |
2064 | * | |
2065 | * returns zero on success or < 0 on failure. | |
2066 | */ | |
2067 | static noinline int insert_new_root(struct btrfs_trans_handle *trans, | |
2068 | struct btrfs_root *root, | |
2069 | struct btrfs_path *path, int level) | |
2070 | { | |
2071 | u64 lower_gen; | |
2072 | struct extent_buffer *lower; | |
2073 | struct extent_buffer *c; | |
2074 | struct extent_buffer *old; | |
2075 | struct btrfs_disk_key lower_key; | |
2076 | ||
2077 | BUG_ON(path->nodes[level]); | |
2078 | BUG_ON(path->nodes[level-1] != root->node); | |
2079 | ||
2080 | lower = path->nodes[level-1]; | |
2081 | if (level == 1) | |
2082 | btrfs_item_key(lower, &lower_key, 0); | |
2083 | else | |
2084 | btrfs_node_key(lower, &lower_key, 0); | |
2085 | ||
2086 | c = btrfs_alloc_free_block(trans, root, root->nodesize, 0, | |
2087 | root->root_key.objectid, &lower_key, | |
2088 | level, root->node->start, 0); | |
2089 | if (IS_ERR(c)) | |
2090 | return PTR_ERR(c); | |
2091 | ||
2092 | root_add_used(root, root->nodesize); | |
2093 | ||
2094 | memset_extent_buffer(c, 0, 0, sizeof(struct btrfs_header)); | |
2095 | btrfs_set_header_nritems(c, 1); | |
2096 | btrfs_set_header_level(c, level); | |
2097 | btrfs_set_header_bytenr(c, c->start); | |
2098 | btrfs_set_header_generation(c, trans->transid); | |
2099 | btrfs_set_header_backref_rev(c, BTRFS_MIXED_BACKREF_REV); | |
2100 | btrfs_set_header_owner(c, root->root_key.objectid); | |
2101 | ||
2102 | write_extent_buffer(c, root->fs_info->fsid, | |
2103 | (unsigned long)btrfs_header_fsid(c), | |
2104 | BTRFS_FSID_SIZE); | |
2105 | ||
2106 | write_extent_buffer(c, root->fs_info->chunk_tree_uuid, | |
2107 | (unsigned long)btrfs_header_chunk_tree_uuid(c), | |
2108 | BTRFS_UUID_SIZE); | |
2109 | ||
2110 | btrfs_set_node_key(c, &lower_key, 0); | |
2111 | btrfs_set_node_blockptr(c, 0, lower->start); | |
2112 | lower_gen = btrfs_header_generation(lower); | |
2113 | WARN_ON(lower_gen != trans->transid); | |
2114 | ||
2115 | btrfs_set_node_ptr_generation(c, 0, lower_gen); | |
2116 | ||
2117 | btrfs_mark_buffer_dirty(c); | |
2118 | ||
2119 | spin_lock(&root->node_lock); | |
2120 | old = root->node; | |
2121 | root->node = c; | |
2122 | spin_unlock(&root->node_lock); | |
2123 | ||
2124 | /* the super has an extra ref to root->node */ | |
2125 | free_extent_buffer(old); | |
2126 | ||
2127 | add_root_to_dirty_list(root); | |
2128 | extent_buffer_get(c); | |
2129 | path->nodes[level] = c; | |
2130 | path->locks[level] = 1; | |
2131 | path->slots[level] = 0; | |
2132 | return 0; | |
2133 | } | |
2134 | ||
2135 | /* | |
2136 | * worker function to insert a single pointer in a node. | |
2137 | * the node should have enough room for the pointer already | |
2138 | * | |
2139 | * slot and level indicate where you want the key to go, and | |
2140 | * blocknr is the block the key points to. | |
2141 | * | |
2142 | * returns zero on success and < 0 on any error | |
2143 | */ | |
2144 | static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root | |
2145 | *root, struct btrfs_path *path, struct btrfs_disk_key | |
2146 | *key, u64 bytenr, int slot, int level) | |
2147 | { | |
2148 | struct extent_buffer *lower; | |
2149 | int nritems; | |
2150 | ||
2151 | BUG_ON(!path->nodes[level]); | |
2152 | btrfs_assert_tree_locked(path->nodes[level]); | |
2153 | lower = path->nodes[level]; | |
2154 | nritems = btrfs_header_nritems(lower); | |
2155 | BUG_ON(slot > nritems); | |
2156 | if (nritems == BTRFS_NODEPTRS_PER_BLOCK(root)) | |
2157 | BUG(); | |
2158 | if (slot != nritems) { | |
2159 | memmove_extent_buffer(lower, | |
2160 | btrfs_node_key_ptr_offset(slot + 1), | |
2161 | btrfs_node_key_ptr_offset(slot), | |
2162 | (nritems - slot) * sizeof(struct btrfs_key_ptr)); | |
2163 | } | |
2164 | btrfs_set_node_key(lower, key, slot); | |
2165 | btrfs_set_node_blockptr(lower, slot, bytenr); | |
2166 | WARN_ON(trans->transid == 0); | |
2167 | btrfs_set_node_ptr_generation(lower, slot, trans->transid); | |
2168 | btrfs_set_header_nritems(lower, nritems + 1); | |
2169 | btrfs_mark_buffer_dirty(lower); | |
2170 | return 0; | |
2171 | } | |
2172 | ||
2173 | /* | |
2174 | * split the node at the specified level in path in two. | |
2175 | * The path is corrected to point to the appropriate node after the split | |
2176 | * | |
2177 | * Before splitting this tries to make some room in the node by pushing | |
2178 | * left and right, if either one works, it returns right away. | |
2179 | * | |
2180 | * returns 0 on success and < 0 on failure | |
2181 | */ | |
2182 | static noinline int split_node(struct btrfs_trans_handle *trans, | |
2183 | struct btrfs_root *root, | |
2184 | struct btrfs_path *path, int level) | |
2185 | { | |
2186 | struct extent_buffer *c; | |
2187 | struct extent_buffer *split; | |
2188 | struct btrfs_disk_key disk_key; | |
2189 | int mid; | |
2190 | int ret; | |
2191 | int wret; | |
2192 | u32 c_nritems; | |
2193 | ||
2194 | c = path->nodes[level]; | |
2195 | WARN_ON(btrfs_header_generation(c) != trans->transid); | |
2196 | if (c == root->node) { | |
2197 | /* trying to split the root, lets make a new one */ | |
2198 | ret = insert_new_root(trans, root, path, level + 1); | |
2199 | if (ret) | |
2200 | return ret; | |
2201 | } else { | |
2202 | ret = push_nodes_for_insert(trans, root, path, level); | |
2203 | c = path->nodes[level]; | |
2204 | if (!ret && btrfs_header_nritems(c) < | |
2205 | BTRFS_NODEPTRS_PER_BLOCK(root) - 3) | |
2206 | return 0; | |
2207 | if (ret < 0) | |
2208 | return ret; | |
2209 | } | |
2210 | ||
2211 | c_nritems = btrfs_header_nritems(c); | |
2212 | mid = (c_nritems + 1) / 2; | |
2213 | btrfs_node_key(c, &disk_key, mid); | |
2214 | ||
2215 | split = btrfs_alloc_free_block(trans, root, root->nodesize, 0, | |
2216 | root->root_key.objectid, | |
2217 | &disk_key, level, c->start, 0); | |
2218 | if (IS_ERR(split)) | |
2219 | return PTR_ERR(split); | |
2220 | ||
2221 | root_add_used(root, root->nodesize); | |
2222 | ||
2223 | memset_extent_buffer(split, 0, 0, sizeof(struct btrfs_header)); | |
2224 | btrfs_set_header_level(split, btrfs_header_level(c)); | |
2225 | btrfs_set_header_bytenr(split, split->start); | |
2226 | btrfs_set_header_generation(split, trans->transid); | |
2227 | btrfs_set_header_backref_rev(split, BTRFS_MIXED_BACKREF_REV); | |
2228 | btrfs_set_header_owner(split, root->root_key.objectid); | |
2229 | write_extent_buffer(split, root->fs_info->fsid, | |
2230 | (unsigned long)btrfs_header_fsid(split), | |
2231 | BTRFS_FSID_SIZE); | |
2232 | write_extent_buffer(split, root->fs_info->chunk_tree_uuid, | |
2233 | (unsigned long)btrfs_header_chunk_tree_uuid(split), | |
2234 | BTRFS_UUID_SIZE); | |
2235 | ||
2236 | ||
2237 | copy_extent_buffer(split, c, | |
2238 | btrfs_node_key_ptr_offset(0), | |
2239 | btrfs_node_key_ptr_offset(mid), | |
2240 | (c_nritems - mid) * sizeof(struct btrfs_key_ptr)); | |
2241 | btrfs_set_header_nritems(split, c_nritems - mid); | |
2242 | btrfs_set_header_nritems(c, mid); | |
2243 | ret = 0; | |
2244 | ||
2245 | btrfs_mark_buffer_dirty(c); | |
2246 | btrfs_mark_buffer_dirty(split); | |
2247 | ||
2248 | wret = insert_ptr(trans, root, path, &disk_key, split->start, | |
2249 | path->slots[level + 1] + 1, | |
2250 | level + 1); | |
2251 | if (wret) | |
2252 | ret = wret; | |
2253 | ||
2254 | if (path->slots[level] >= mid) { | |
2255 | path->slots[level] -= mid; | |
2256 | btrfs_tree_unlock(c); | |
2257 | free_extent_buffer(c); | |
2258 | path->nodes[level] = split; | |
2259 | path->slots[level + 1] += 1; | |
2260 | } else { | |
2261 | btrfs_tree_unlock(split); | |
2262 | free_extent_buffer(split); | |
2263 | } | |
2264 | return ret; | |
2265 | } | |
2266 | ||
2267 | /* | |
2268 | * how many bytes are required to store the items in a leaf. start | |
2269 | * and nr indicate which items in the leaf to check. This totals up the | |
2270 | * space used both by the item structs and the item data | |
2271 | */ | |
2272 | static int leaf_space_used(struct extent_buffer *l, int start, int nr) | |
2273 | { | |
2274 | int data_len; | |
2275 | int nritems = btrfs_header_nritems(l); | |
2276 | int end = min(nritems, start + nr) - 1; | |
2277 | ||
2278 | if (!nr) | |
2279 | return 0; | |
2280 | data_len = btrfs_item_end_nr(l, start); | |
2281 | data_len = data_len - btrfs_item_offset_nr(l, end); | |
2282 | data_len += sizeof(struct btrfs_item) * nr; | |
2283 | WARN_ON(data_len < 0); | |
2284 | return data_len; | |
2285 | } | |
2286 | ||
2287 | /* | |
2288 | * The space between the end of the leaf items and | |
2289 | * the start of the leaf data. IOW, how much room | |
2290 | * the leaf has left for both items and data | |
2291 | */ | |
2292 | noinline int btrfs_leaf_free_space(struct btrfs_root *root, | |
2293 | struct extent_buffer *leaf) | |
2294 | { | |
2295 | int nritems = btrfs_header_nritems(leaf); | |
2296 | int ret; | |
2297 | ret = BTRFS_LEAF_DATA_SIZE(root) - leaf_space_used(leaf, 0, nritems); | |
2298 | if (ret < 0) { | |
2299 | printk(KERN_CRIT "leaf free space ret %d, leaf data size %lu, " | |
2300 | "used %d nritems %d\n", | |
2301 | ret, (unsigned long) BTRFS_LEAF_DATA_SIZE(root), | |
2302 | leaf_space_used(leaf, 0, nritems), nritems); | |
2303 | } | |
2304 | return ret; | |
2305 | } | |
2306 | ||
2307 | /* | |
2308 | * min slot controls the lowest index we're willing to push to the | |
2309 | * right. We'll push up to and including min_slot, but no lower | |
2310 | */ | |
2311 | static noinline int __push_leaf_right(struct btrfs_trans_handle *trans, | |
2312 | struct btrfs_root *root, | |
2313 | struct btrfs_path *path, | |
2314 | int data_size, int empty, | |
2315 | struct extent_buffer *right, | |
2316 | int free_space, u32 left_nritems, | |
2317 | u32 min_slot) | |
2318 | { | |
2319 | struct extent_buffer *left = path->nodes[0]; | |
2320 | struct extent_buffer *upper = path->nodes[1]; | |
2321 | struct btrfs_disk_key disk_key; | |
2322 | int slot; | |
2323 | u32 i; | |
2324 | int push_space = 0; | |
2325 | int push_items = 0; | |
2326 | struct btrfs_item *item; | |
2327 | u32 nr; | |
2328 | u32 right_nritems; | |
2329 | u32 data_end; | |
2330 | u32 this_item_size; | |
2331 | ||
2332 | if (empty) | |
2333 | nr = 0; | |
2334 | else | |
2335 | nr = max_t(u32, 1, min_slot); | |
2336 | ||
2337 | if (path->slots[0] >= left_nritems) | |
2338 | push_space += data_size; | |
2339 | ||
2340 | slot = path->slots[1]; | |
2341 | i = left_nritems - 1; | |
2342 | while (i >= nr) { | |
2343 | item = btrfs_item_nr(left, i); | |
2344 | ||
2345 | if (!empty && push_items > 0) { | |
2346 | if (path->slots[0] > i) | |
2347 | break; | |
2348 | if (path->slots[0] == i) { | |
2349 | int space = btrfs_leaf_free_space(root, left); | |
2350 | if (space + push_space * 2 > free_space) | |
2351 | break; | |
2352 | } | |
2353 | } | |
2354 | ||
2355 | if (path->slots[0] == i) | |
2356 | push_space += data_size; | |
2357 | ||
2358 | if (!left->map_token) { | |
2359 | map_extent_buffer(left, (unsigned long)item, | |
2360 | sizeof(struct btrfs_item), | |
2361 | &left->map_token, &left->kaddr, | |
2362 | &left->map_start, &left->map_len, | |
2363 | KM_USER1); | |
2364 | } | |
2365 | ||
2366 | this_item_size = btrfs_item_size(left, item); | |
2367 | if (this_item_size + sizeof(*item) + push_space > free_space) | |
2368 | break; | |
2369 | ||
2370 | push_items++; | |
2371 | push_space += this_item_size + sizeof(*item); | |
2372 | if (i == 0) | |
2373 | break; | |
2374 | i--; | |
2375 | } | |
2376 | if (left->map_token) { | |
2377 | unmap_extent_buffer(left, left->map_token, KM_USER1); | |
2378 | left->map_token = NULL; | |
2379 | } | |
2380 | ||
2381 | if (push_items == 0) | |
2382 | goto out_unlock; | |
2383 | ||
2384 | if (!empty && push_items == left_nritems) | |
2385 | WARN_ON(1); | |
2386 | ||
2387 | /* push left to right */ | |
2388 | right_nritems = btrfs_header_nritems(right); | |
2389 | ||
2390 | push_space = btrfs_item_end_nr(left, left_nritems - push_items); | |
2391 | push_space -= leaf_data_end(root, left); | |
2392 | ||
2393 | /* make room in the right data area */ | |
2394 | data_end = leaf_data_end(root, right); | |
2395 | memmove_extent_buffer(right, | |
2396 | btrfs_leaf_data(right) + data_end - push_space, | |
2397 | btrfs_leaf_data(right) + data_end, | |
2398 | BTRFS_LEAF_DATA_SIZE(root) - data_end); | |
2399 | ||
2400 | /* copy from the left data area */ | |
2401 | copy_extent_buffer(right, left, btrfs_leaf_data(right) + | |
2402 | BTRFS_LEAF_DATA_SIZE(root) - push_space, | |
2403 | btrfs_leaf_data(left) + leaf_data_end(root, left), | |
2404 | push_space); | |
2405 | ||
2406 | memmove_extent_buffer(right, btrfs_item_nr_offset(push_items), | |
2407 | btrfs_item_nr_offset(0), | |
2408 | right_nritems * sizeof(struct btrfs_item)); | |
2409 | ||
2410 | /* copy the items from left to right */ | |
2411 | copy_extent_buffer(right, left, btrfs_item_nr_offset(0), | |
2412 | btrfs_item_nr_offset(left_nritems - push_items), | |
2413 | push_items * sizeof(struct btrfs_item)); | |
2414 | ||
2415 | /* update the item pointers */ | |
2416 | right_nritems += push_items; | |
2417 | btrfs_set_header_nritems(right, right_nritems); | |
2418 | push_space = BTRFS_LEAF_DATA_SIZE(root); | |
2419 | for (i = 0; i < right_nritems; i++) { | |
2420 | item = btrfs_item_nr(right, i); | |
2421 | if (!right->map_token) { | |
2422 | map_extent_buffer(right, (unsigned long)item, | |
2423 | sizeof(struct btrfs_item), | |
2424 | &right->map_token, &right->kaddr, | |
2425 | &right->map_start, &right->map_len, | |
2426 | KM_USER1); | |
2427 | } | |
2428 | push_space -= btrfs_item_size(right, item); | |
2429 | btrfs_set_item_offset(right, item, push_space); | |
2430 | } | |
2431 | ||
2432 | if (right->map_token) { | |
2433 | unmap_extent_buffer(right, right->map_token, KM_USER1); | |
2434 | right->map_token = NULL; | |
2435 | } | |
2436 | left_nritems -= push_items; | |
2437 | btrfs_set_header_nritems(left, left_nritems); | |
2438 | ||
2439 | if (left_nritems) | |
2440 | btrfs_mark_buffer_dirty(left); | |
2441 | else | |
2442 | clean_tree_block(trans, root, left); | |
2443 | ||
2444 | btrfs_mark_buffer_dirty(right); | |
2445 | ||
2446 | btrfs_item_key(right, &disk_key, 0); | |
2447 | btrfs_set_node_key(upper, &disk_key, slot + 1); | |
2448 | btrfs_mark_buffer_dirty(upper); | |
2449 | ||
2450 | /* then fixup the leaf pointer in the path */ | |
2451 | if (path->slots[0] >= left_nritems) { | |
2452 | path->slots[0] -= left_nritems; | |
2453 | if (btrfs_header_nritems(path->nodes[0]) == 0) | |
2454 | clean_tree_block(trans, root, path->nodes[0]); | |
2455 | btrfs_tree_unlock(path->nodes[0]); | |
2456 | free_extent_buffer(path->nodes[0]); | |
2457 | path->nodes[0] = right; | |
2458 | path->slots[1] += 1; | |
2459 | } else { | |
2460 | btrfs_tree_unlock(right); | |
2461 | free_extent_buffer(right); | |
2462 | } | |
2463 | return 0; | |
2464 | ||
2465 | out_unlock: | |
2466 | btrfs_tree_unlock(right); | |
2467 | free_extent_buffer(right); | |
2468 | return 1; | |
2469 | } | |
2470 | ||
2471 | /* | |
2472 | * push some data in the path leaf to the right, trying to free up at | |
2473 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
2474 | * | |
2475 | * returns 1 if the push failed because the other node didn't have enough | |
2476 | * room, 0 if everything worked out and < 0 if there were major errors. | |
2477 | * | |
2478 | * this will push starting from min_slot to the end of the leaf. It won't | |
2479 | * push any slot lower than min_slot | |
2480 | */ | |
2481 | static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root | |
2482 | *root, struct btrfs_path *path, | |
2483 | int min_data_size, int data_size, | |
2484 | int empty, u32 min_slot) | |
2485 | { | |
2486 | struct extent_buffer *left = path->nodes[0]; | |
2487 | struct extent_buffer *right; | |
2488 | struct extent_buffer *upper; | |
2489 | int slot; | |
2490 | int free_space; | |
2491 | u32 left_nritems; | |
2492 | int ret; | |
2493 | ||
2494 | if (!path->nodes[1]) | |
2495 | return 1; | |
2496 | ||
2497 | slot = path->slots[1]; | |
2498 | upper = path->nodes[1]; | |
2499 | if (slot >= btrfs_header_nritems(upper) - 1) | |
2500 | return 1; | |
2501 | ||
2502 | btrfs_assert_tree_locked(path->nodes[1]); | |
2503 | ||
2504 | right = read_node_slot(root, upper, slot + 1); | |
2505 | btrfs_tree_lock(right); | |
2506 | btrfs_set_lock_blocking(right); | |
2507 | ||
2508 | free_space = btrfs_leaf_free_space(root, right); | |
2509 | if (free_space < data_size) | |
2510 | goto out_unlock; | |
2511 | ||
2512 | /* cow and double check */ | |
2513 | ret = btrfs_cow_block(trans, root, right, upper, | |
2514 | slot + 1, &right); | |
2515 | if (ret) | |
2516 | goto out_unlock; | |
2517 | ||
2518 | free_space = btrfs_leaf_free_space(root, right); | |
2519 | if (free_space < data_size) | |
2520 | goto out_unlock; | |
2521 | ||
2522 | left_nritems = btrfs_header_nritems(left); | |
2523 | if (left_nritems == 0) | |
2524 | goto out_unlock; | |
2525 | ||
2526 | return __push_leaf_right(trans, root, path, min_data_size, empty, | |
2527 | right, free_space, left_nritems, min_slot); | |
2528 | out_unlock: | |
2529 | btrfs_tree_unlock(right); | |
2530 | free_extent_buffer(right); | |
2531 | return 1; | |
2532 | } | |
2533 | ||
2534 | /* | |
2535 | * push some data in the path leaf to the left, trying to free up at | |
2536 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
2537 | * | |
2538 | * max_slot can put a limit on how far into the leaf we'll push items. The | |
2539 | * item at 'max_slot' won't be touched. Use (u32)-1 to make us do all the | |
2540 | * items | |
2541 | */ | |
2542 | static noinline int __push_leaf_left(struct btrfs_trans_handle *trans, | |
2543 | struct btrfs_root *root, | |
2544 | struct btrfs_path *path, int data_size, | |
2545 | int empty, struct extent_buffer *left, | |
2546 | int free_space, u32 right_nritems, | |
2547 | u32 max_slot) | |
2548 | { | |
2549 | struct btrfs_disk_key disk_key; | |
2550 | struct extent_buffer *right = path->nodes[0]; | |
2551 | int slot; | |
2552 | int i; | |
2553 | int push_space = 0; | |
2554 | int push_items = 0; | |
2555 | struct btrfs_item *item; | |
2556 | u32 old_left_nritems; | |
2557 | u32 nr; | |
2558 | int ret = 0; | |
2559 | int wret; | |
2560 | u32 this_item_size; | |
2561 | u32 old_left_item_size; | |
2562 | ||
2563 | slot = path->slots[1]; | |
2564 | ||
2565 | if (empty) | |
2566 | nr = min(right_nritems, max_slot); | |
2567 | else | |
2568 | nr = min(right_nritems - 1, max_slot); | |
2569 | ||
2570 | for (i = 0; i < nr; i++) { | |
2571 | item = btrfs_item_nr(right, i); | |
2572 | if (!right->map_token) { | |
2573 | map_extent_buffer(right, (unsigned long)item, | |
2574 | sizeof(struct btrfs_item), | |
2575 | &right->map_token, &right->kaddr, | |
2576 | &right->map_start, &right->map_len, | |
2577 | KM_USER1); | |
2578 | } | |
2579 | ||
2580 | if (!empty && push_items > 0) { | |
2581 | if (path->slots[0] < i) | |
2582 | break; | |
2583 | if (path->slots[0] == i) { | |
2584 | int space = btrfs_leaf_free_space(root, right); | |
2585 | if (space + push_space * 2 > free_space) | |
2586 | break; | |
2587 | } | |
2588 | } | |
2589 | ||
2590 | if (path->slots[0] == i) | |
2591 | push_space += data_size; | |
2592 | ||
2593 | this_item_size = btrfs_item_size(right, item); | |
2594 | if (this_item_size + sizeof(*item) + push_space > free_space) | |
2595 | break; | |
2596 | ||
2597 | push_items++; | |
2598 | push_space += this_item_size + sizeof(*item); | |
2599 | } | |
2600 | ||
2601 | if (right->map_token) { | |
2602 | unmap_extent_buffer(right, right->map_token, KM_USER1); | |
2603 | right->map_token = NULL; | |
2604 | } | |
2605 | ||
2606 | if (push_items == 0) { | |
2607 | ret = 1; | |
2608 | goto out; | |
2609 | } | |
2610 | if (!empty && push_items == btrfs_header_nritems(right)) | |
2611 | WARN_ON(1); | |
2612 | ||
2613 | /* push data from right to left */ | |
2614 | copy_extent_buffer(left, right, | |
2615 | btrfs_item_nr_offset(btrfs_header_nritems(left)), | |
2616 | btrfs_item_nr_offset(0), | |
2617 | push_items * sizeof(struct btrfs_item)); | |
2618 | ||
2619 | push_space = BTRFS_LEAF_DATA_SIZE(root) - | |
2620 | btrfs_item_offset_nr(right, push_items - 1); | |
2621 | ||
2622 | copy_extent_buffer(left, right, btrfs_leaf_data(left) + | |
2623 | leaf_data_end(root, left) - push_space, | |
2624 | btrfs_leaf_data(right) + | |
2625 | btrfs_item_offset_nr(right, push_items - 1), | |
2626 | push_space); | |
2627 | old_left_nritems = btrfs_header_nritems(left); | |
2628 | BUG_ON(old_left_nritems <= 0); | |
2629 | ||
2630 | old_left_item_size = btrfs_item_offset_nr(left, old_left_nritems - 1); | |
2631 | for (i = old_left_nritems; i < old_left_nritems + push_items; i++) { | |
2632 | u32 ioff; | |
2633 | ||
2634 | item = btrfs_item_nr(left, i); | |
2635 | if (!left->map_token) { | |
2636 | map_extent_buffer(left, (unsigned long)item, | |
2637 | sizeof(struct btrfs_item), | |
2638 | &left->map_token, &left->kaddr, | |
2639 | &left->map_start, &left->map_len, | |
2640 | KM_USER1); | |
2641 | } | |
2642 | ||
2643 | ioff = btrfs_item_offset(left, item); | |
2644 | btrfs_set_item_offset(left, item, | |
2645 | ioff - (BTRFS_LEAF_DATA_SIZE(root) - old_left_item_size)); | |
2646 | } | |
2647 | btrfs_set_header_nritems(left, old_left_nritems + push_items); | |
2648 | if (left->map_token) { | |
2649 | unmap_extent_buffer(left, left->map_token, KM_USER1); | |
2650 | left->map_token = NULL; | |
2651 | } | |
2652 | ||
2653 | /* fixup right node */ | |
2654 | if (push_items > right_nritems) { | |
2655 | printk(KERN_CRIT "push items %d nr %u\n", push_items, | |
2656 | right_nritems); | |
2657 | WARN_ON(1); | |
2658 | } | |
2659 | ||
2660 | if (push_items < right_nritems) { | |
2661 | push_space = btrfs_item_offset_nr(right, push_items - 1) - | |
2662 | leaf_data_end(root, right); | |
2663 | memmove_extent_buffer(right, btrfs_leaf_data(right) + | |
2664 | BTRFS_LEAF_DATA_SIZE(root) - push_space, | |
2665 | btrfs_leaf_data(right) + | |
2666 | leaf_data_end(root, right), push_space); | |
2667 | ||
2668 | memmove_extent_buffer(right, btrfs_item_nr_offset(0), | |
2669 | btrfs_item_nr_offset(push_items), | |
2670 | (btrfs_header_nritems(right) - push_items) * | |
2671 | sizeof(struct btrfs_item)); | |
2672 | } | |
2673 | right_nritems -= push_items; | |
2674 | btrfs_set_header_nritems(right, right_nritems); | |
2675 | push_space = BTRFS_LEAF_DATA_SIZE(root); | |
2676 | for (i = 0; i < right_nritems; i++) { | |
2677 | item = btrfs_item_nr(right, i); | |
2678 | ||
2679 | if (!right->map_token) { | |
2680 | map_extent_buffer(right, (unsigned long)item, | |
2681 | sizeof(struct btrfs_item), | |
2682 | &right->map_token, &right->kaddr, | |
2683 | &right->map_start, &right->map_len, | |
2684 | KM_USER1); | |
2685 | } | |
2686 | ||
2687 | push_space = push_space - btrfs_item_size(right, item); | |
2688 | btrfs_set_item_offset(right, item, push_space); | |
2689 | } | |
2690 | if (right->map_token) { | |
2691 | unmap_extent_buffer(right, right->map_token, KM_USER1); | |
2692 | right->map_token = NULL; | |
2693 | } | |
2694 | ||
2695 | btrfs_mark_buffer_dirty(left); | |
2696 | if (right_nritems) | |
2697 | btrfs_mark_buffer_dirty(right); | |
2698 | else | |
2699 | clean_tree_block(trans, root, right); | |
2700 | ||
2701 | btrfs_item_key(right, &disk_key, 0); | |
2702 | wret = fixup_low_keys(trans, root, path, &disk_key, 1); | |
2703 | if (wret) | |
2704 | ret = wret; | |
2705 | ||
2706 | /* then fixup the leaf pointer in the path */ | |
2707 | if (path->slots[0] < push_items) { | |
2708 | path->slots[0] += old_left_nritems; | |
2709 | btrfs_tree_unlock(path->nodes[0]); | |
2710 | free_extent_buffer(path->nodes[0]); | |
2711 | path->nodes[0] = left; | |
2712 | path->slots[1] -= 1; | |
2713 | } else { | |
2714 | btrfs_tree_unlock(left); | |
2715 | free_extent_buffer(left); | |
2716 | path->slots[0] -= push_items; | |
2717 | } | |
2718 | BUG_ON(path->slots[0] < 0); | |
2719 | return ret; | |
2720 | out: | |
2721 | btrfs_tree_unlock(left); | |
2722 | free_extent_buffer(left); | |
2723 | return ret; | |
2724 | } | |
2725 | ||
2726 | /* | |
2727 | * push some data in the path leaf to the left, trying to free up at | |
2728 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
2729 | * | |
2730 | * max_slot can put a limit on how far into the leaf we'll push items. The | |
2731 | * item at 'max_slot' won't be touched. Use (u32)-1 to make us push all the | |
2732 | * items | |
2733 | */ | |
2734 | static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root | |
2735 | *root, struct btrfs_path *path, int min_data_size, | |
2736 | int data_size, int empty, u32 max_slot) | |
2737 | { | |
2738 | struct extent_buffer *right = path->nodes[0]; | |
2739 | struct extent_buffer *left; | |
2740 | int slot; | |
2741 | int free_space; | |
2742 | u32 right_nritems; | |
2743 | int ret = 0; | |
2744 | ||
2745 | slot = path->slots[1]; | |
2746 | if (slot == 0) | |
2747 | return 1; | |
2748 | if (!path->nodes[1]) | |
2749 | return 1; | |
2750 | ||
2751 | right_nritems = btrfs_header_nritems(right); | |
2752 | if (right_nritems == 0) | |
2753 | return 1; | |
2754 | ||
2755 | btrfs_assert_tree_locked(path->nodes[1]); | |
2756 | ||
2757 | left = read_node_slot(root, path->nodes[1], slot - 1); | |
2758 | btrfs_tree_lock(left); | |
2759 | btrfs_set_lock_blocking(left); | |
2760 | ||
2761 | free_space = btrfs_leaf_free_space(root, left); | |
2762 | if (free_space < data_size) { | |
2763 | ret = 1; | |
2764 | goto out; | |
2765 | } | |
2766 | ||
2767 | /* cow and double check */ | |
2768 | ret = btrfs_cow_block(trans, root, left, | |
2769 | path->nodes[1], slot - 1, &left); | |
2770 | if (ret) { | |
2771 | /* we hit -ENOSPC, but it isn't fatal here */ | |
2772 | ret = 1; | |
2773 | goto out; | |
2774 | } | |
2775 | ||
2776 | free_space = btrfs_leaf_free_space(root, left); | |
2777 | if (free_space < data_size) { | |
2778 | ret = 1; | |
2779 | goto out; | |
2780 | } | |
2781 | ||
2782 | return __push_leaf_left(trans, root, path, min_data_size, | |
2783 | empty, left, free_space, right_nritems, | |
2784 | max_slot); | |
2785 | out: | |
2786 | btrfs_tree_unlock(left); | |
2787 | free_extent_buffer(left); | |
2788 | return ret; | |
2789 | } | |
2790 | ||
2791 | /* | |
2792 | * split the path's leaf in two, making sure there is at least data_size | |
2793 | * available for the resulting leaf level of the path. | |
2794 | * | |
2795 | * returns 0 if all went well and < 0 on failure. | |
2796 | */ | |
2797 | static noinline int copy_for_split(struct btrfs_trans_handle *trans, | |
2798 | struct btrfs_root *root, | |
2799 | struct btrfs_path *path, | |
2800 | struct extent_buffer *l, | |
2801 | struct extent_buffer *right, | |
2802 | int slot, int mid, int nritems) | |
2803 | { | |
2804 | int data_copy_size; | |
2805 | int rt_data_off; | |
2806 | int i; | |
2807 | int ret = 0; | |
2808 | int wret; | |
2809 | struct btrfs_disk_key disk_key; | |
2810 | ||
2811 | nritems = nritems - mid; | |
2812 | btrfs_set_header_nritems(right, nritems); | |
2813 | data_copy_size = btrfs_item_end_nr(l, mid) - leaf_data_end(root, l); | |
2814 | ||
2815 | copy_extent_buffer(right, l, btrfs_item_nr_offset(0), | |
2816 | btrfs_item_nr_offset(mid), | |
2817 | nritems * sizeof(struct btrfs_item)); | |
2818 | ||
2819 | copy_extent_buffer(right, l, | |
2820 | btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) - | |
2821 | data_copy_size, btrfs_leaf_data(l) + | |
2822 | leaf_data_end(root, l), data_copy_size); | |
2823 | ||
2824 | rt_data_off = BTRFS_LEAF_DATA_SIZE(root) - | |
2825 | btrfs_item_end_nr(l, mid); | |
2826 | ||
2827 | for (i = 0; i < nritems; i++) { | |
2828 | struct btrfs_item *item = btrfs_item_nr(right, i); | |
2829 | u32 ioff; | |
2830 | ||
2831 | if (!right->map_token) { | |
2832 | map_extent_buffer(right, (unsigned long)item, | |
2833 | sizeof(struct btrfs_item), | |
2834 | &right->map_token, &right->kaddr, | |
2835 | &right->map_start, &right->map_len, | |
2836 | KM_USER1); | |
2837 | } | |
2838 | ||
2839 | ioff = btrfs_item_offset(right, item); | |
2840 | btrfs_set_item_offset(right, item, ioff + rt_data_off); | |
2841 | } | |
2842 | ||
2843 | if (right->map_token) { | |
2844 | unmap_extent_buffer(right, right->map_token, KM_USER1); | |
2845 | right->map_token = NULL; | |
2846 | } | |
2847 | ||
2848 | btrfs_set_header_nritems(l, mid); | |
2849 | ret = 0; | |
2850 | btrfs_item_key(right, &disk_key, 0); | |
2851 | wret = insert_ptr(trans, root, path, &disk_key, right->start, | |
2852 | path->slots[1] + 1, 1); | |
2853 | if (wret) | |
2854 | ret = wret; | |
2855 | ||
2856 | btrfs_mark_buffer_dirty(right); | |
2857 | btrfs_mark_buffer_dirty(l); | |
2858 | BUG_ON(path->slots[0] != slot); | |
2859 | ||
2860 | if (mid <= slot) { | |
2861 | btrfs_tree_unlock(path->nodes[0]); | |
2862 | free_extent_buffer(path->nodes[0]); | |
2863 | path->nodes[0] = right; | |
2864 | path->slots[0] -= mid; | |
2865 | path->slots[1] += 1; | |
2866 | } else { | |
2867 | btrfs_tree_unlock(right); | |
2868 | free_extent_buffer(right); | |
2869 | } | |
2870 | ||
2871 | BUG_ON(path->slots[0] < 0); | |
2872 | ||
2873 | return ret; | |
2874 | } | |
2875 | ||
2876 | /* | |
2877 | * double splits happen when we need to insert a big item in the middle | |
2878 | * of a leaf. A double split can leave us with 3 mostly empty leaves: | |
2879 | * leaf: [ slots 0 - N] [ our target ] [ N + 1 - total in leaf ] | |
2880 | * A B C | |
2881 | * | |
2882 | * We avoid this by trying to push the items on either side of our target | |
2883 | * into the adjacent leaves. If all goes well we can avoid the double split | |
2884 | * completely. | |
2885 | */ | |
2886 | static noinline int push_for_double_split(struct btrfs_trans_handle *trans, | |
2887 | struct btrfs_root *root, | |
2888 | struct btrfs_path *path, | |
2889 | int data_size) | |
2890 | { | |
2891 | int ret; | |
2892 | int progress = 0; | |
2893 | int slot; | |
2894 | u32 nritems; | |
2895 | ||
2896 | slot = path->slots[0]; | |
2897 | ||
2898 | /* | |
2899 | * try to push all the items after our slot into the | |
2900 | * right leaf | |
2901 | */ | |
2902 | ret = push_leaf_right(trans, root, path, 1, data_size, 0, slot); | |
2903 | if (ret < 0) | |
2904 | return ret; | |
2905 | ||
2906 | if (ret == 0) | |
2907 | progress++; | |
2908 | ||
2909 | nritems = btrfs_header_nritems(path->nodes[0]); | |
2910 | /* | |
2911 | * our goal is to get our slot at the start or end of a leaf. If | |
2912 | * we've done so we're done | |
2913 | */ | |
2914 | if (path->slots[0] == 0 || path->slots[0] == nritems) | |
2915 | return 0; | |
2916 | ||
2917 | if (btrfs_leaf_free_space(root, path->nodes[0]) >= data_size) | |
2918 | return 0; | |
2919 | ||
2920 | /* try to push all the items before our slot into the next leaf */ | |
2921 | slot = path->slots[0]; | |
2922 | ret = push_leaf_left(trans, root, path, 1, data_size, 0, slot); | |
2923 | if (ret < 0) | |
2924 | return ret; | |
2925 | ||
2926 | if (ret == 0) | |
2927 | progress++; | |
2928 | ||
2929 | if (progress) | |
2930 | return 0; | |
2931 | return 1; | |
2932 | } | |
2933 | ||
2934 | /* | |
2935 | * split the path's leaf in two, making sure there is at least data_size | |
2936 | * available for the resulting leaf level of the path. | |
2937 | * | |
2938 | * returns 0 if all went well and < 0 on failure. | |
2939 | */ | |
2940 | static noinline int split_leaf(struct btrfs_trans_handle *trans, | |
2941 | struct btrfs_root *root, | |
2942 | struct btrfs_key *ins_key, | |
2943 | struct btrfs_path *path, int data_size, | |
2944 | int extend) | |
2945 | { | |
2946 | struct btrfs_disk_key disk_key; | |
2947 | struct extent_buffer *l; | |
2948 | u32 nritems; | |
2949 | int mid; | |
2950 | int slot; | |
2951 | struct extent_buffer *right; | |
2952 | int ret = 0; | |
2953 | int wret; | |
2954 | int split; | |
2955 | int num_doubles = 0; | |
2956 | int tried_avoid_double = 0; | |
2957 | ||
2958 | l = path->nodes[0]; | |
2959 | slot = path->slots[0]; | |
2960 | if (extend && data_size + btrfs_item_size_nr(l, slot) + | |
2961 | sizeof(struct btrfs_item) > BTRFS_LEAF_DATA_SIZE(root)) | |
2962 | return -EOVERFLOW; | |
2963 | ||
2964 | /* first try to make some room by pushing left and right */ | |
2965 | if (data_size) { | |
2966 | wret = push_leaf_right(trans, root, path, data_size, | |
2967 | data_size, 0, 0); | |
2968 | if (wret < 0) | |
2969 | return wret; | |
2970 | if (wret) { | |
2971 | wret = push_leaf_left(trans, root, path, data_size, | |
2972 | data_size, 0, (u32)-1); | |
2973 | if (wret < 0) | |
2974 | return wret; | |
2975 | } | |
2976 | l = path->nodes[0]; | |
2977 | ||
2978 | /* did the pushes work? */ | |
2979 | if (btrfs_leaf_free_space(root, l) >= data_size) | |
2980 | return 0; | |
2981 | } | |
2982 | ||
2983 | if (!path->nodes[1]) { | |
2984 | ret = insert_new_root(trans, root, path, 1); | |
2985 | if (ret) | |
2986 | return ret; | |
2987 | } | |
2988 | again: | |
2989 | split = 1; | |
2990 | l = path->nodes[0]; | |
2991 | slot = path->slots[0]; | |
2992 | nritems = btrfs_header_nritems(l); | |
2993 | mid = (nritems + 1) / 2; | |
2994 | ||
2995 | if (mid <= slot) { | |
2996 | if (nritems == 1 || | |
2997 | leaf_space_used(l, mid, nritems - mid) + data_size > | |
2998 | BTRFS_LEAF_DATA_SIZE(root)) { | |
2999 | if (slot >= nritems) { | |
3000 | split = 0; | |
3001 | } else { | |
3002 | mid = slot; | |
3003 | if (mid != nritems && | |
3004 | leaf_space_used(l, mid, nritems - mid) + | |
3005 | data_size > BTRFS_LEAF_DATA_SIZE(root)) { | |
3006 | if (data_size && !tried_avoid_double) | |
3007 | goto push_for_double; | |
3008 | split = 2; | |
3009 | } | |
3010 | } | |
3011 | } | |
3012 | } else { | |
3013 | if (leaf_space_used(l, 0, mid) + data_size > | |
3014 | BTRFS_LEAF_DATA_SIZE(root)) { | |
3015 | if (!extend && data_size && slot == 0) { | |
3016 | split = 0; | |
3017 | } else if ((extend || !data_size) && slot == 0) { | |
3018 | mid = 1; | |
3019 | } else { | |
3020 | mid = slot; | |
3021 | if (mid != nritems && | |
3022 | leaf_space_used(l, mid, nritems - mid) + | |
3023 | data_size > BTRFS_LEAF_DATA_SIZE(root)) { | |
3024 | if (data_size && !tried_avoid_double) | |
3025 | goto push_for_double; | |
3026 | split = 2 ; | |
3027 | } | |
3028 | } | |
3029 | } | |
3030 | } | |
3031 | ||
3032 | if (split == 0) | |
3033 | btrfs_cpu_key_to_disk(&disk_key, ins_key); | |
3034 | else | |
3035 | btrfs_item_key(l, &disk_key, mid); | |
3036 | ||
3037 | right = btrfs_alloc_free_block(trans, root, root->leafsize, 0, | |
3038 | root->root_key.objectid, | |
3039 | &disk_key, 0, l->start, 0); | |
3040 | if (IS_ERR(right)) | |
3041 | return PTR_ERR(right); | |
3042 | ||
3043 | root_add_used(root, root->leafsize); | |
3044 | ||
3045 | memset_extent_buffer(right, 0, 0, sizeof(struct btrfs_header)); | |
3046 | btrfs_set_header_bytenr(right, right->start); | |
3047 | btrfs_set_header_generation(right, trans->transid); | |
3048 | btrfs_set_header_backref_rev(right, BTRFS_MIXED_BACKREF_REV); | |
3049 | btrfs_set_header_owner(right, root->root_key.objectid); | |
3050 | btrfs_set_header_level(right, 0); | |
3051 | write_extent_buffer(right, root->fs_info->fsid, | |
3052 | (unsigned long)btrfs_header_fsid(right), | |
3053 | BTRFS_FSID_SIZE); | |
3054 | ||
3055 | write_extent_buffer(right, root->fs_info->chunk_tree_uuid, | |
3056 | (unsigned long)btrfs_header_chunk_tree_uuid(right), | |
3057 | BTRFS_UUID_SIZE); | |
3058 | ||
3059 | if (split == 0) { | |
3060 | if (mid <= slot) { | |
3061 | btrfs_set_header_nritems(right, 0); | |
3062 | wret = insert_ptr(trans, root, path, | |
3063 | &disk_key, right->start, | |
3064 | path->slots[1] + 1, 1); | |
3065 | if (wret) | |
3066 | ret = wret; | |
3067 | ||
3068 | btrfs_tree_unlock(path->nodes[0]); | |
3069 | free_extent_buffer(path->nodes[0]); | |
3070 | path->nodes[0] = right; | |
3071 | path->slots[0] = 0; | |
3072 | path->slots[1] += 1; | |
3073 | } else { | |
3074 | btrfs_set_header_nritems(right, 0); | |
3075 | wret = insert_ptr(trans, root, path, | |
3076 | &disk_key, | |
3077 | right->start, | |
3078 | path->slots[1], 1); | |
3079 | if (wret) | |
3080 | ret = wret; | |
3081 | btrfs_tree_unlock(path->nodes[0]); | |
3082 | free_extent_buffer(path->nodes[0]); | |
3083 | path->nodes[0] = right; | |
3084 | path->slots[0] = 0; | |
3085 | if (path->slots[1] == 0) { | |
3086 | wret = fixup_low_keys(trans, root, | |
3087 | path, &disk_key, 1); | |
3088 | if (wret) | |
3089 | ret = wret; | |
3090 | } | |
3091 | } | |
3092 | btrfs_mark_buffer_dirty(right); | |
3093 | return ret; | |
3094 | } | |
3095 | ||
3096 | ret = copy_for_split(trans, root, path, l, right, slot, mid, nritems); | |
3097 | BUG_ON(ret); | |
3098 | ||
3099 | if (split == 2) { | |
3100 | BUG_ON(num_doubles != 0); | |
3101 | num_doubles++; | |
3102 | goto again; | |
3103 | } | |
3104 | ||
3105 | return ret; | |
3106 | ||
3107 | push_for_double: | |
3108 | push_for_double_split(trans, root, path, data_size); | |
3109 | tried_avoid_double = 1; | |
3110 | if (btrfs_leaf_free_space(root, path->nodes[0]) >= data_size) | |
3111 | return 0; | |
3112 | goto again; | |
3113 | } | |
3114 | ||
3115 | static noinline int setup_leaf_for_split(struct btrfs_trans_handle *trans, | |
3116 | struct btrfs_root *root, | |
3117 | struct btrfs_path *path, int ins_len) | |
3118 | { | |
3119 | struct btrfs_key key; | |
3120 | struct extent_buffer *leaf; | |
3121 | struct btrfs_file_extent_item *fi; | |
3122 | u64 extent_len = 0; | |
3123 | u32 item_size; | |
3124 | int ret; | |
3125 | ||
3126 | leaf = path->nodes[0]; | |
3127 | btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); | |
3128 | ||
3129 | BUG_ON(key.type != BTRFS_EXTENT_DATA_KEY && | |
3130 | key.type != BTRFS_EXTENT_CSUM_KEY); | |
3131 | ||
3132 | if (btrfs_leaf_free_space(root, leaf) >= ins_len) | |
3133 | return 0; | |
3134 | ||
3135 | item_size = btrfs_item_size_nr(leaf, path->slots[0]); | |
3136 | if (key.type == BTRFS_EXTENT_DATA_KEY) { | |
3137 | fi = btrfs_item_ptr(leaf, path->slots[0], | |
3138 | struct btrfs_file_extent_item); | |
3139 | extent_len = btrfs_file_extent_num_bytes(leaf, fi); | |
3140 | } | |
3141 | btrfs_release_path(root, path); | |
3142 | ||
3143 | path->keep_locks = 1; | |
3144 | path->search_for_split = 1; | |
3145 | ret = btrfs_search_slot(trans, root, &key, path, 0, 1); | |
3146 | path->search_for_split = 0; | |
3147 | if (ret < 0) | |
3148 | goto err; | |
3149 | ||
3150 | ret = -EAGAIN; | |
3151 | leaf = path->nodes[0]; | |
3152 | /* if our item isn't there or got smaller, return now */ | |
3153 | if (ret > 0 || item_size != btrfs_item_size_nr(leaf, path->slots[0])) | |
3154 | goto err; | |
3155 | ||
3156 | /* the leaf has changed, it now has room. return now */ | |
3157 | if (btrfs_leaf_free_space(root, path->nodes[0]) >= ins_len) | |
3158 | goto err; | |
3159 | ||
3160 | if (key.type == BTRFS_EXTENT_DATA_KEY) { | |
3161 | fi = btrfs_item_ptr(leaf, path->slots[0], | |
3162 | struct btrfs_file_extent_item); | |
3163 | if (extent_len != btrfs_file_extent_num_bytes(leaf, fi)) | |
3164 | goto err; | |
3165 | } | |
3166 | ||
3167 | btrfs_set_path_blocking(path); | |
3168 | ret = split_leaf(trans, root, &key, path, ins_len, 1); | |
3169 | if (ret) | |
3170 | goto err; | |
3171 | ||
3172 | path->keep_locks = 0; | |
3173 | btrfs_unlock_up_safe(path, 1); | |
3174 | return 0; | |
3175 | err: | |
3176 | path->keep_locks = 0; | |
3177 | return ret; | |
3178 | } | |
3179 | ||
3180 | static noinline int split_item(struct btrfs_trans_handle *trans, | |
3181 | struct btrfs_root *root, | |
3182 | struct btrfs_path *path, | |
3183 | struct btrfs_key *new_key, | |
3184 | unsigned long split_offset) | |
3185 | { | |
3186 | struct extent_buffer *leaf; | |
3187 | struct btrfs_item *item; | |
3188 | struct btrfs_item *new_item; | |
3189 | int slot; | |
3190 | char *buf; | |
3191 | u32 nritems; | |
3192 | u32 item_size; | |
3193 | u32 orig_offset; | |
3194 | struct btrfs_disk_key disk_key; | |
3195 | ||
3196 | leaf = path->nodes[0]; | |
3197 | BUG_ON(btrfs_leaf_free_space(root, leaf) < sizeof(struct btrfs_item)); | |
3198 | ||
3199 | btrfs_set_path_blocking(path); | |
3200 | ||
3201 | item = btrfs_item_nr(leaf, path->slots[0]); | |
3202 | orig_offset = btrfs_item_offset(leaf, item); | |
3203 | item_size = btrfs_item_size(leaf, item); | |
3204 | ||
3205 | buf = kmalloc(item_size, GFP_NOFS); | |
3206 | if (!buf) | |
3207 | return -ENOMEM; | |
3208 | ||
3209 | read_extent_buffer(leaf, buf, btrfs_item_ptr_offset(leaf, | |
3210 | path->slots[0]), item_size); | |
3211 | ||
3212 | slot = path->slots[0] + 1; | |
3213 | nritems = btrfs_header_nritems(leaf); | |
3214 | if (slot != nritems) { | |
3215 | /* shift the items */ | |
3216 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + 1), | |
3217 | btrfs_item_nr_offset(slot), | |
3218 | (nritems - slot) * sizeof(struct btrfs_item)); | |
3219 | } | |
3220 | ||
3221 | btrfs_cpu_key_to_disk(&disk_key, new_key); | |
3222 | btrfs_set_item_key(leaf, &disk_key, slot); | |
3223 | ||
3224 | new_item = btrfs_item_nr(leaf, slot); | |
3225 | ||
3226 | btrfs_set_item_offset(leaf, new_item, orig_offset); | |
3227 | btrfs_set_item_size(leaf, new_item, item_size - split_offset); | |
3228 | ||
3229 | btrfs_set_item_offset(leaf, item, | |
3230 | orig_offset + item_size - split_offset); | |
3231 | btrfs_set_item_size(leaf, item, split_offset); | |
3232 | ||
3233 | btrfs_set_header_nritems(leaf, nritems + 1); | |
3234 | ||
3235 | /* write the data for the start of the original item */ | |
3236 | write_extent_buffer(leaf, buf, | |
3237 | btrfs_item_ptr_offset(leaf, path->slots[0]), | |
3238 | split_offset); | |
3239 | ||
3240 | /* write the data for the new item */ | |
3241 | write_extent_buffer(leaf, buf + split_offset, | |
3242 | btrfs_item_ptr_offset(leaf, slot), | |
3243 | item_size - split_offset); | |
3244 | btrfs_mark_buffer_dirty(leaf); | |
3245 | ||
3246 | BUG_ON(btrfs_leaf_free_space(root, leaf) < 0); | |
3247 | kfree(buf); | |
3248 | return 0; | |
3249 | } | |
3250 | ||
3251 | /* | |
3252 | * This function splits a single item into two items, | |
3253 | * giving 'new_key' to the new item and splitting the | |
3254 | * old one at split_offset (from the start of the item). | |
3255 | * | |
3256 | * The path may be released by this operation. After | |
3257 | * the split, the path is pointing to the old item. The | |
3258 | * new item is going to be in the same node as the old one. | |
3259 | * | |
3260 | * Note, the item being split must be smaller enough to live alone on | |
3261 | * a tree block with room for one extra struct btrfs_item | |
3262 | * | |
3263 | * This allows us to split the item in place, keeping a lock on the | |
3264 | * leaf the entire time. | |
3265 | */ | |
3266 | int btrfs_split_item(struct btrfs_trans_handle *trans, | |
3267 | struct btrfs_root *root, | |
3268 | struct btrfs_path *path, | |
3269 | struct btrfs_key *new_key, | |
3270 | unsigned long split_offset) | |
3271 | { | |
3272 | int ret; | |
3273 | ret = setup_leaf_for_split(trans, root, path, | |
3274 | sizeof(struct btrfs_item)); | |
3275 | if (ret) | |
3276 | return ret; | |
3277 | ||
3278 | ret = split_item(trans, root, path, new_key, split_offset); | |
3279 | return ret; | |
3280 | } | |
3281 | ||
3282 | /* | |
3283 | * This function duplicate a item, giving 'new_key' to the new item. | |
3284 | * It guarantees both items live in the same tree leaf and the new item | |
3285 | * is contiguous with the original item. | |
3286 | * | |
3287 | * This allows us to split file extent in place, keeping a lock on the | |
3288 | * leaf the entire time. | |
3289 | */ | |
3290 | int btrfs_duplicate_item(struct btrfs_trans_handle *trans, | |
3291 | struct btrfs_root *root, | |
3292 | struct btrfs_path *path, | |
3293 | struct btrfs_key *new_key) | |
3294 | { | |
3295 | struct extent_buffer *leaf; | |
3296 | int ret; | |
3297 | u32 item_size; | |
3298 | ||
3299 | leaf = path->nodes[0]; | |
3300 | item_size = btrfs_item_size_nr(leaf, path->slots[0]); | |
3301 | ret = setup_leaf_for_split(trans, root, path, | |
3302 | item_size + sizeof(struct btrfs_item)); | |
3303 | if (ret) | |
3304 | return ret; | |
3305 | ||
3306 | path->slots[0]++; | |
3307 | ret = setup_items_for_insert(trans, root, path, new_key, &item_size, | |
3308 | item_size, item_size + | |
3309 | sizeof(struct btrfs_item), 1); | |
3310 | BUG_ON(ret); | |
3311 | ||
3312 | leaf = path->nodes[0]; | |
3313 | memcpy_extent_buffer(leaf, | |
3314 | btrfs_item_ptr_offset(leaf, path->slots[0]), | |
3315 | btrfs_item_ptr_offset(leaf, path->slots[0] - 1), | |
3316 | item_size); | |
3317 | return 0; | |
3318 | } | |
3319 | ||
3320 | /* | |
3321 | * make the item pointed to by the path smaller. new_size indicates | |
3322 | * how small to make it, and from_end tells us if we just chop bytes | |
3323 | * off the end of the item or if we shift the item to chop bytes off | |
3324 | * the front. | |
3325 | */ | |
3326 | int btrfs_truncate_item(struct btrfs_trans_handle *trans, | |
3327 | struct btrfs_root *root, | |
3328 | struct btrfs_path *path, | |
3329 | u32 new_size, int from_end) | |
3330 | { | |
3331 | int ret = 0; | |
3332 | int slot; | |
3333 | int slot_orig; | |
3334 | struct extent_buffer *leaf; | |
3335 | struct btrfs_item *item; | |
3336 | u32 nritems; | |
3337 | unsigned int data_end; | |
3338 | unsigned int old_data_start; | |
3339 | unsigned int old_size; | |
3340 | unsigned int size_diff; | |
3341 | int i; | |
3342 | ||
3343 | slot_orig = path->slots[0]; | |
3344 | leaf = path->nodes[0]; | |
3345 | slot = path->slots[0]; | |
3346 | ||
3347 | old_size = btrfs_item_size_nr(leaf, slot); | |
3348 | if (old_size == new_size) | |
3349 | return 0; | |
3350 | ||
3351 | nritems = btrfs_header_nritems(leaf); | |
3352 | data_end = leaf_data_end(root, leaf); | |
3353 | ||
3354 | old_data_start = btrfs_item_offset_nr(leaf, slot); | |
3355 | ||
3356 | size_diff = old_size - new_size; | |
3357 | ||
3358 | BUG_ON(slot < 0); | |
3359 | BUG_ON(slot >= nritems); | |
3360 | ||
3361 | /* | |
3362 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
3363 | */ | |
3364 | /* first correct the data pointers */ | |
3365 | for (i = slot; i < nritems; i++) { | |
3366 | u32 ioff; | |
3367 | item = btrfs_item_nr(leaf, i); | |
3368 | ||
3369 | if (!leaf->map_token) { | |
3370 | map_extent_buffer(leaf, (unsigned long)item, | |
3371 | sizeof(struct btrfs_item), | |
3372 | &leaf->map_token, &leaf->kaddr, | |
3373 | &leaf->map_start, &leaf->map_len, | |
3374 | KM_USER1); | |
3375 | } | |
3376 | ||
3377 | ioff = btrfs_item_offset(leaf, item); | |
3378 | btrfs_set_item_offset(leaf, item, ioff + size_diff); | |
3379 | } | |
3380 | ||
3381 | if (leaf->map_token) { | |
3382 | unmap_extent_buffer(leaf, leaf->map_token, KM_USER1); | |
3383 | leaf->map_token = NULL; | |
3384 | } | |
3385 | ||
3386 | /* shift the data */ | |
3387 | if (from_end) { | |
3388 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + | |
3389 | data_end + size_diff, btrfs_leaf_data(leaf) + | |
3390 | data_end, old_data_start + new_size - data_end); | |
3391 | } else { | |
3392 | struct btrfs_disk_key disk_key; | |
3393 | u64 offset; | |
3394 | ||
3395 | btrfs_item_key(leaf, &disk_key, slot); | |
3396 | ||
3397 | if (btrfs_disk_key_type(&disk_key) == BTRFS_EXTENT_DATA_KEY) { | |
3398 | unsigned long ptr; | |
3399 | struct btrfs_file_extent_item *fi; | |
3400 | ||
3401 | fi = btrfs_item_ptr(leaf, slot, | |
3402 | struct btrfs_file_extent_item); | |
3403 | fi = (struct btrfs_file_extent_item *)( | |
3404 | (unsigned long)fi - size_diff); | |
3405 | ||
3406 | if (btrfs_file_extent_type(leaf, fi) == | |
3407 | BTRFS_FILE_EXTENT_INLINE) { | |
3408 | ptr = btrfs_item_ptr_offset(leaf, slot); | |
3409 | memmove_extent_buffer(leaf, ptr, | |
3410 | (unsigned long)fi, | |
3411 | offsetof(struct btrfs_file_extent_item, | |
3412 | disk_bytenr)); | |
3413 | } | |
3414 | } | |
3415 | ||
3416 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + | |
3417 | data_end + size_diff, btrfs_leaf_data(leaf) + | |
3418 | data_end, old_data_start - data_end); | |
3419 | ||
3420 | offset = btrfs_disk_key_offset(&disk_key); | |
3421 | btrfs_set_disk_key_offset(&disk_key, offset + size_diff); | |
3422 | btrfs_set_item_key(leaf, &disk_key, slot); | |
3423 | if (slot == 0) | |
3424 | fixup_low_keys(trans, root, path, &disk_key, 1); | |
3425 | } | |
3426 | ||
3427 | item = btrfs_item_nr(leaf, slot); | |
3428 | btrfs_set_item_size(leaf, item, new_size); | |
3429 | btrfs_mark_buffer_dirty(leaf); | |
3430 | ||
3431 | ret = 0; | |
3432 | if (btrfs_leaf_free_space(root, leaf) < 0) { | |
3433 | btrfs_print_leaf(root, leaf); | |
3434 | BUG(); | |
3435 | } | |
3436 | return ret; | |
3437 | } | |
3438 | ||
3439 | /* | |
3440 | * make the item pointed to by the path bigger, data_size is the new size. | |
3441 | */ | |
3442 | int btrfs_extend_item(struct btrfs_trans_handle *trans, | |
3443 | struct btrfs_root *root, struct btrfs_path *path, | |
3444 | u32 data_size) | |
3445 | { | |
3446 | int ret = 0; | |
3447 | int slot; | |
3448 | int slot_orig; | |
3449 | struct extent_buffer *leaf; | |
3450 | struct btrfs_item *item; | |
3451 | u32 nritems; | |
3452 | unsigned int data_end; | |
3453 | unsigned int old_data; | |
3454 | unsigned int old_size; | |
3455 | int i; | |
3456 | ||
3457 | slot_orig = path->slots[0]; | |
3458 | leaf = path->nodes[0]; | |
3459 | ||
3460 | nritems = btrfs_header_nritems(leaf); | |
3461 | data_end = leaf_data_end(root, leaf); | |
3462 | ||
3463 | if (btrfs_leaf_free_space(root, leaf) < data_size) { | |
3464 | btrfs_print_leaf(root, leaf); | |
3465 | BUG(); | |
3466 | } | |
3467 | slot = path->slots[0]; | |
3468 | old_data = btrfs_item_end_nr(leaf, slot); | |
3469 | ||
3470 | BUG_ON(slot < 0); | |
3471 | if (slot >= nritems) { | |
3472 | btrfs_print_leaf(root, leaf); | |
3473 | printk(KERN_CRIT "slot %d too large, nritems %d\n", | |
3474 | slot, nritems); | |
3475 | BUG_ON(1); | |
3476 | } | |
3477 | ||
3478 | /* | |
3479 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
3480 | */ | |
3481 | /* first correct the data pointers */ | |
3482 | for (i = slot; i < nritems; i++) { | |
3483 | u32 ioff; | |
3484 | item = btrfs_item_nr(leaf, i); | |
3485 | ||
3486 | if (!leaf->map_token) { | |
3487 | map_extent_buffer(leaf, (unsigned long)item, | |
3488 | sizeof(struct btrfs_item), | |
3489 | &leaf->map_token, &leaf->kaddr, | |
3490 | &leaf->map_start, &leaf->map_len, | |
3491 | KM_USER1); | |
3492 | } | |
3493 | ioff = btrfs_item_offset(leaf, item); | |
3494 | btrfs_set_item_offset(leaf, item, ioff - data_size); | |
3495 | } | |
3496 | ||
3497 | if (leaf->map_token) { | |
3498 | unmap_extent_buffer(leaf, leaf->map_token, KM_USER1); | |
3499 | leaf->map_token = NULL; | |
3500 | } | |
3501 | ||
3502 | /* shift the data */ | |
3503 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + | |
3504 | data_end - data_size, btrfs_leaf_data(leaf) + | |
3505 | data_end, old_data - data_end); | |
3506 | ||
3507 | data_end = old_data; | |
3508 | old_size = btrfs_item_size_nr(leaf, slot); | |
3509 | item = btrfs_item_nr(leaf, slot); | |
3510 | btrfs_set_item_size(leaf, item, old_size + data_size); | |
3511 | btrfs_mark_buffer_dirty(leaf); | |
3512 | ||
3513 | ret = 0; | |
3514 | if (btrfs_leaf_free_space(root, leaf) < 0) { | |
3515 | btrfs_print_leaf(root, leaf); | |
3516 | BUG(); | |
3517 | } | |
3518 | return ret; | |
3519 | } | |
3520 | ||
3521 | /* | |
3522 | * Given a key and some data, insert items into the tree. | |
3523 | * This does all the path init required, making room in the tree if needed. | |
3524 | * Returns the number of keys that were inserted. | |
3525 | */ | |
3526 | int btrfs_insert_some_items(struct btrfs_trans_handle *trans, | |
3527 | struct btrfs_root *root, | |
3528 | struct btrfs_path *path, | |
3529 | struct btrfs_key *cpu_key, u32 *data_size, | |
3530 | int nr) | |
3531 | { | |
3532 | struct extent_buffer *leaf; | |
3533 | struct btrfs_item *item; | |
3534 | int ret = 0; | |
3535 | int slot; | |
3536 | int i; | |
3537 | u32 nritems; | |
3538 | u32 total_data = 0; | |
3539 | u32 total_size = 0; | |
3540 | unsigned int data_end; | |
3541 | struct btrfs_disk_key disk_key; | |
3542 | struct btrfs_key found_key; | |
3543 | ||
3544 | for (i = 0; i < nr; i++) { | |
3545 | if (total_size + data_size[i] + sizeof(struct btrfs_item) > | |
3546 | BTRFS_LEAF_DATA_SIZE(root)) { | |
3547 | break; | |
3548 | nr = i; | |
3549 | } | |
3550 | total_data += data_size[i]; | |
3551 | total_size += data_size[i] + sizeof(struct btrfs_item); | |
3552 | } | |
3553 | BUG_ON(nr == 0); | |
3554 | ||
3555 | ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1); | |
3556 | if (ret == 0) | |
3557 | return -EEXIST; | |
3558 | if (ret < 0) | |
3559 | goto out; | |
3560 | ||
3561 | leaf = path->nodes[0]; | |
3562 | ||
3563 | nritems = btrfs_header_nritems(leaf); | |
3564 | data_end = leaf_data_end(root, leaf); | |
3565 | ||
3566 | if (btrfs_leaf_free_space(root, leaf) < total_size) { | |
3567 | for (i = nr; i >= 0; i--) { | |
3568 | total_data -= data_size[i]; | |
3569 | total_size -= data_size[i] + sizeof(struct btrfs_item); | |
3570 | if (total_size < btrfs_leaf_free_space(root, leaf)) | |
3571 | break; | |
3572 | } | |
3573 | nr = i; | |
3574 | } | |
3575 | ||
3576 | slot = path->slots[0]; | |
3577 | BUG_ON(slot < 0); | |
3578 | ||
3579 | if (slot != nritems) { | |
3580 | unsigned int old_data = btrfs_item_end_nr(leaf, slot); | |
3581 | ||
3582 | item = btrfs_item_nr(leaf, slot); | |
3583 | btrfs_item_key_to_cpu(leaf, &found_key, slot); | |
3584 | ||
3585 | /* figure out how many keys we can insert in here */ | |
3586 | total_data = data_size[0]; | |
3587 | for (i = 1; i < nr; i++) { | |
3588 | if (btrfs_comp_cpu_keys(&found_key, cpu_key + i) <= 0) | |
3589 | break; | |
3590 | total_data += data_size[i]; | |
3591 | } | |
3592 | nr = i; | |
3593 | ||
3594 | if (old_data < data_end) { | |
3595 | btrfs_print_leaf(root, leaf); | |
3596 | printk(KERN_CRIT "slot %d old_data %d data_end %d\n", | |
3597 | slot, old_data, data_end); | |
3598 | BUG_ON(1); | |
3599 | } | |
3600 | /* | |
3601 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
3602 | */ | |
3603 | /* first correct the data pointers */ | |
3604 | WARN_ON(leaf->map_token); | |
3605 | for (i = slot; i < nritems; i++) { | |
3606 | u32 ioff; | |
3607 | ||
3608 | item = btrfs_item_nr(leaf, i); | |
3609 | if (!leaf->map_token) { | |
3610 | map_extent_buffer(leaf, (unsigned long)item, | |
3611 | sizeof(struct btrfs_item), | |
3612 | &leaf->map_token, &leaf->kaddr, | |
3613 | &leaf->map_start, &leaf->map_len, | |
3614 | KM_USER1); | |
3615 | } | |
3616 | ||
3617 | ioff = btrfs_item_offset(leaf, item); | |
3618 | btrfs_set_item_offset(leaf, item, ioff - total_data); | |
3619 | } | |
3620 | if (leaf->map_token) { | |
3621 | unmap_extent_buffer(leaf, leaf->map_token, KM_USER1); | |
3622 | leaf->map_token = NULL; | |
3623 | } | |
3624 | ||
3625 | /* shift the items */ | |
3626 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr), | |
3627 | btrfs_item_nr_offset(slot), | |
3628 | (nritems - slot) * sizeof(struct btrfs_item)); | |
3629 | ||
3630 | /* shift the data */ | |
3631 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + | |
3632 | data_end - total_data, btrfs_leaf_data(leaf) + | |
3633 | data_end, old_data - data_end); | |
3634 | data_end = old_data; | |
3635 | } else { | |
3636 | /* | |
3637 | * this sucks but it has to be done, if we are inserting at | |
3638 | * the end of the leaf only insert 1 of the items, since we | |
3639 | * have no way of knowing whats on the next leaf and we'd have | |
3640 | * to drop our current locks to figure it out | |
3641 | */ | |
3642 | nr = 1; | |
3643 | } | |
3644 | ||
3645 | /* setup the item for the new data */ | |
3646 | for (i = 0; i < nr; i++) { | |
3647 | btrfs_cpu_key_to_disk(&disk_key, cpu_key + i); | |
3648 | btrfs_set_item_key(leaf, &disk_key, slot + i); | |
3649 | item = btrfs_item_nr(leaf, slot + i); | |
3650 | btrfs_set_item_offset(leaf, item, data_end - data_size[i]); | |
3651 | data_end -= data_size[i]; | |
3652 | btrfs_set_item_size(leaf, item, data_size[i]); | |
3653 | } | |
3654 | btrfs_set_header_nritems(leaf, nritems + nr); | |
3655 | btrfs_mark_buffer_dirty(leaf); | |
3656 | ||
3657 | ret = 0; | |
3658 | if (slot == 0) { | |
3659 | btrfs_cpu_key_to_disk(&disk_key, cpu_key); | |
3660 | ret = fixup_low_keys(trans, root, path, &disk_key, 1); | |
3661 | } | |
3662 | ||
3663 | if (btrfs_leaf_free_space(root, leaf) < 0) { | |
3664 | btrfs_print_leaf(root, leaf); | |
3665 | BUG(); | |
3666 | } | |
3667 | out: | |
3668 | if (!ret) | |
3669 | ret = nr; | |
3670 | return ret; | |
3671 | } | |
3672 | ||
3673 | /* | |
3674 | * this is a helper for btrfs_insert_empty_items, the main goal here is | |
3675 | * to save stack depth by doing the bulk of the work in a function | |
3676 | * that doesn't call btrfs_search_slot | |
3677 | */ | |
3678 | static noinline_for_stack int | |
3679 | setup_items_for_insert(struct btrfs_trans_handle *trans, | |
3680 | struct btrfs_root *root, struct btrfs_path *path, | |
3681 | struct btrfs_key *cpu_key, u32 *data_size, | |
3682 | u32 total_data, u32 total_size, int nr) | |
3683 | { | |
3684 | struct btrfs_item *item; | |
3685 | int i; | |
3686 | u32 nritems; | |
3687 | unsigned int data_end; | |
3688 | struct btrfs_disk_key disk_key; | |
3689 | int ret; | |
3690 | struct extent_buffer *leaf; | |
3691 | int slot; | |
3692 | ||
3693 | leaf = path->nodes[0]; | |
3694 | slot = path->slots[0]; | |
3695 | ||
3696 | nritems = btrfs_header_nritems(leaf); | |
3697 | data_end = leaf_data_end(root, leaf); | |
3698 | ||
3699 | if (btrfs_leaf_free_space(root, leaf) < total_size) { | |
3700 | btrfs_print_leaf(root, leaf); | |
3701 | printk(KERN_CRIT "not enough freespace need %u have %d\n", | |
3702 | total_size, btrfs_leaf_free_space(root, leaf)); | |
3703 | BUG(); | |
3704 | } | |
3705 | ||
3706 | if (slot != nritems) { | |
3707 | unsigned int old_data = btrfs_item_end_nr(leaf, slot); | |
3708 | ||
3709 | if (old_data < data_end) { | |
3710 | btrfs_print_leaf(root, leaf); | |
3711 | printk(KERN_CRIT "slot %d old_data %d data_end %d\n", | |
3712 | slot, old_data, data_end); | |
3713 | BUG_ON(1); | |
3714 | } | |
3715 | /* | |
3716 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
3717 | */ | |
3718 | /* first correct the data pointers */ | |
3719 | WARN_ON(leaf->map_token); | |
3720 | for (i = slot; i < nritems; i++) { | |
3721 | u32 ioff; | |
3722 | ||
3723 | item = btrfs_item_nr(leaf, i); | |
3724 | if (!leaf->map_token) { | |
3725 | map_extent_buffer(leaf, (unsigned long)item, | |
3726 | sizeof(struct btrfs_item), | |
3727 | &leaf->map_token, &leaf->kaddr, | |
3728 | &leaf->map_start, &leaf->map_len, | |
3729 | KM_USER1); | |
3730 | } | |
3731 | ||
3732 | ioff = btrfs_item_offset(leaf, item); | |
3733 | btrfs_set_item_offset(leaf, item, ioff - total_data); | |
3734 | } | |
3735 | if (leaf->map_token) { | |
3736 | unmap_extent_buffer(leaf, leaf->map_token, KM_USER1); | |
3737 | leaf->map_token = NULL; | |
3738 | } | |
3739 | ||
3740 | /* shift the items */ | |
3741 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr), | |
3742 | btrfs_item_nr_offset(slot), | |
3743 | (nritems - slot) * sizeof(struct btrfs_item)); | |
3744 | ||
3745 | /* shift the data */ | |
3746 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + | |
3747 | data_end - total_data, btrfs_leaf_data(leaf) + | |
3748 | data_end, old_data - data_end); | |
3749 | data_end = old_data; | |
3750 | } | |
3751 | ||
3752 | /* setup the item for the new data */ | |
3753 | for (i = 0; i < nr; i++) { | |
3754 | btrfs_cpu_key_to_disk(&disk_key, cpu_key + i); | |
3755 | btrfs_set_item_key(leaf, &disk_key, slot + i); | |
3756 | item = btrfs_item_nr(leaf, slot + i); | |
3757 | btrfs_set_item_offset(leaf, item, data_end - data_size[i]); | |
3758 | data_end -= data_size[i]; | |
3759 | btrfs_set_item_size(leaf, item, data_size[i]); | |
3760 | } | |
3761 | ||
3762 | btrfs_set_header_nritems(leaf, nritems + nr); | |
3763 | ||
3764 | ret = 0; | |
3765 | if (slot == 0) { | |
3766 | struct btrfs_disk_key disk_key; | |
3767 | btrfs_cpu_key_to_disk(&disk_key, cpu_key); | |
3768 | ret = fixup_low_keys(trans, root, path, &disk_key, 1); | |
3769 | } | |
3770 | btrfs_unlock_up_safe(path, 1); | |
3771 | btrfs_mark_buffer_dirty(leaf); | |
3772 | ||
3773 | if (btrfs_leaf_free_space(root, leaf) < 0) { | |
3774 | btrfs_print_leaf(root, leaf); | |
3775 | BUG(); | |
3776 | } | |
3777 | return ret; | |
3778 | } | |
3779 | ||
3780 | /* | |
3781 | * Given a key and some data, insert items into the tree. | |
3782 | * This does all the path init required, making room in the tree if needed. | |
3783 | */ | |
3784 | int btrfs_insert_empty_items(struct btrfs_trans_handle *trans, | |
3785 | struct btrfs_root *root, | |
3786 | struct btrfs_path *path, | |
3787 | struct btrfs_key *cpu_key, u32 *data_size, | |
3788 | int nr) | |
3789 | { | |
3790 | struct extent_buffer *leaf; | |
3791 | int ret = 0; | |
3792 | int slot; | |
3793 | int i; | |
3794 | u32 total_size = 0; | |
3795 | u32 total_data = 0; | |
3796 | ||
3797 | for (i = 0; i < nr; i++) | |
3798 | total_data += data_size[i]; | |
3799 | ||
3800 | total_size = total_data + (nr * sizeof(struct btrfs_item)); | |
3801 | ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1); | |
3802 | if (ret == 0) | |
3803 | return -EEXIST; | |
3804 | if (ret < 0) | |
3805 | goto out; | |
3806 | ||
3807 | leaf = path->nodes[0]; | |
3808 | slot = path->slots[0]; | |
3809 | BUG_ON(slot < 0); | |
3810 | ||
3811 | ret = setup_items_for_insert(trans, root, path, cpu_key, data_size, | |
3812 | total_data, total_size, nr); | |
3813 | ||
3814 | out: | |
3815 | return ret; | |
3816 | } | |
3817 | ||
3818 | /* | |
3819 | * Given a key and some data, insert an item into the tree. | |
3820 | * This does all the path init required, making room in the tree if needed. | |
3821 | */ | |
3822 | int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root | |
3823 | *root, struct btrfs_key *cpu_key, void *data, u32 | |
3824 | data_size) | |
3825 | { | |
3826 | int ret = 0; | |
3827 | struct btrfs_path *path; | |
3828 | struct extent_buffer *leaf; | |
3829 | unsigned long ptr; | |
3830 | ||
3831 | path = btrfs_alloc_path(); | |
3832 | BUG_ON(!path); | |
3833 | ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size); | |
3834 | if (!ret) { | |
3835 | leaf = path->nodes[0]; | |
3836 | ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); | |
3837 | write_extent_buffer(leaf, data, ptr, data_size); | |
3838 | btrfs_mark_buffer_dirty(leaf); | |
3839 | } | |
3840 | btrfs_free_path(path); | |
3841 | return ret; | |
3842 | } | |
3843 | ||
3844 | /* | |
3845 | * delete the pointer from a given node. | |
3846 | * | |
3847 | * the tree should have been previously balanced so the deletion does not | |
3848 | * empty a node. | |
3849 | */ | |
3850 | static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root, | |
3851 | struct btrfs_path *path, int level, int slot) | |
3852 | { | |
3853 | struct extent_buffer *parent = path->nodes[level]; | |
3854 | u32 nritems; | |
3855 | int ret = 0; | |
3856 | int wret; | |
3857 | ||
3858 | nritems = btrfs_header_nritems(parent); | |
3859 | if (slot != nritems - 1) { | |
3860 | memmove_extent_buffer(parent, | |
3861 | btrfs_node_key_ptr_offset(slot), | |
3862 | btrfs_node_key_ptr_offset(slot + 1), | |
3863 | sizeof(struct btrfs_key_ptr) * | |
3864 | (nritems - slot - 1)); | |
3865 | } | |
3866 | nritems--; | |
3867 | btrfs_set_header_nritems(parent, nritems); | |
3868 | if (nritems == 0 && parent == root->node) { | |
3869 | BUG_ON(btrfs_header_level(root->node) != 1); | |
3870 | /* just turn the root into a leaf and break */ | |
3871 | btrfs_set_header_level(root->node, 0); | |
3872 | } else if (slot == 0) { | |
3873 | struct btrfs_disk_key disk_key; | |
3874 | ||
3875 | btrfs_node_key(parent, &disk_key, 0); | |
3876 | wret = fixup_low_keys(trans, root, path, &disk_key, level + 1); | |
3877 | if (wret) | |
3878 | ret = wret; | |
3879 | } | |
3880 | btrfs_mark_buffer_dirty(parent); | |
3881 | return ret; | |
3882 | } | |
3883 | ||
3884 | /* | |
3885 | * a helper function to delete the leaf pointed to by path->slots[1] and | |
3886 | * path->nodes[1]. | |
3887 | * | |
3888 | * This deletes the pointer in path->nodes[1] and frees the leaf | |
3889 | * block extent. zero is returned if it all worked out, < 0 otherwise. | |
3890 | * | |
3891 | * The path must have already been setup for deleting the leaf, including | |
3892 | * all the proper balancing. path->nodes[1] must be locked. | |
3893 | */ | |
3894 | static noinline int btrfs_del_leaf(struct btrfs_trans_handle *trans, | |
3895 | struct btrfs_root *root, | |
3896 | struct btrfs_path *path, | |
3897 | struct extent_buffer *leaf) | |
3898 | { | |
3899 | int ret; | |
3900 | ||
3901 | WARN_ON(btrfs_header_generation(leaf) != trans->transid); | |
3902 | ret = del_ptr(trans, root, path, 1, path->slots[1]); | |
3903 | if (ret) | |
3904 | return ret; | |
3905 | ||
3906 | /* | |
3907 | * btrfs_free_extent is expensive, we want to make sure we | |
3908 | * aren't holding any locks when we call it | |
3909 | */ | |
3910 | btrfs_unlock_up_safe(path, 0); | |
3911 | ||
3912 | root_sub_used(root, leaf->len); | |
3913 | ||
3914 | btrfs_free_tree_block(trans, root, leaf, 0, 1); | |
3915 | return 0; | |
3916 | } | |
3917 | /* | |
3918 | * delete the item at the leaf level in path. If that empties | |
3919 | * the leaf, remove it from the tree | |
3920 | */ | |
3921 | int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root, | |
3922 | struct btrfs_path *path, int slot, int nr) | |
3923 | { | |
3924 | struct extent_buffer *leaf; | |
3925 | struct btrfs_item *item; | |
3926 | int last_off; | |
3927 | int dsize = 0; | |
3928 | int ret = 0; | |
3929 | int wret; | |
3930 | int i; | |
3931 | u32 nritems; | |
3932 | ||
3933 | leaf = path->nodes[0]; | |
3934 | last_off = btrfs_item_offset_nr(leaf, slot + nr - 1); | |
3935 | ||
3936 | for (i = 0; i < nr; i++) | |
3937 | dsize += btrfs_item_size_nr(leaf, slot + i); | |
3938 | ||
3939 | nritems = btrfs_header_nritems(leaf); | |
3940 | ||
3941 | if (slot + nr != nritems) { | |
3942 | int data_end = leaf_data_end(root, leaf); | |
3943 | ||
3944 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + | |
3945 | data_end + dsize, | |
3946 | btrfs_leaf_data(leaf) + data_end, | |
3947 | last_off - data_end); | |
3948 | ||
3949 | for (i = slot + nr; i < nritems; i++) { | |
3950 | u32 ioff; | |
3951 | ||
3952 | item = btrfs_item_nr(leaf, i); | |
3953 | if (!leaf->map_token) { | |
3954 | map_extent_buffer(leaf, (unsigned long)item, | |
3955 | sizeof(struct btrfs_item), | |
3956 | &leaf->map_token, &leaf->kaddr, | |
3957 | &leaf->map_start, &leaf->map_len, | |
3958 | KM_USER1); | |
3959 | } | |
3960 | ioff = btrfs_item_offset(leaf, item); | |
3961 | btrfs_set_item_offset(leaf, item, ioff + dsize); | |
3962 | } | |
3963 | ||
3964 | if (leaf->map_token) { | |
3965 | unmap_extent_buffer(leaf, leaf->map_token, KM_USER1); | |
3966 | leaf->map_token = NULL; | |
3967 | } | |
3968 | ||
3969 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot), | |
3970 | btrfs_item_nr_offset(slot + nr), | |
3971 | sizeof(struct btrfs_item) * | |
3972 | (nritems - slot - nr)); | |
3973 | } | |
3974 | btrfs_set_header_nritems(leaf, nritems - nr); | |
3975 | nritems -= nr; | |
3976 | ||
3977 | /* delete the leaf if we've emptied it */ | |
3978 | if (nritems == 0) { | |
3979 | if (leaf == root->node) { | |
3980 | btrfs_set_header_level(leaf, 0); | |
3981 | } else { | |
3982 | btrfs_set_path_blocking(path); | |
3983 | clean_tree_block(trans, root, leaf); | |
3984 | ret = btrfs_del_leaf(trans, root, path, leaf); | |
3985 | BUG_ON(ret); | |
3986 | } | |
3987 | } else { | |
3988 | int used = leaf_space_used(leaf, 0, nritems); | |
3989 | if (slot == 0) { | |
3990 | struct btrfs_disk_key disk_key; | |
3991 | ||
3992 | btrfs_item_key(leaf, &disk_key, 0); | |
3993 | wret = fixup_low_keys(trans, root, path, | |
3994 | &disk_key, 1); | |
3995 | if (wret) | |
3996 | ret = wret; | |
3997 | } | |
3998 | ||
3999 | /* delete the leaf if it is mostly empty */ | |
4000 | if (used < BTRFS_LEAF_DATA_SIZE(root) / 3) { | |
4001 | /* push_leaf_left fixes the path. | |
4002 | * make sure the path still points to our leaf | |
4003 | * for possible call to del_ptr below | |
4004 | */ | |
4005 | slot = path->slots[1]; | |
4006 | extent_buffer_get(leaf); | |
4007 | ||
4008 | btrfs_set_path_blocking(path); | |
4009 | wret = push_leaf_left(trans, root, path, 1, 1, | |
4010 | 1, (u32)-1); | |
4011 | if (wret < 0 && wret != -ENOSPC) | |
4012 | ret = wret; | |
4013 | ||
4014 | if (path->nodes[0] == leaf && | |
4015 | btrfs_header_nritems(leaf)) { | |
4016 | wret = push_leaf_right(trans, root, path, 1, | |
4017 | 1, 1, 0); | |
4018 | if (wret < 0 && wret != -ENOSPC) | |
4019 | ret = wret; | |
4020 | } | |
4021 | ||
4022 | if (btrfs_header_nritems(leaf) == 0) { | |
4023 | path->slots[1] = slot; | |
4024 | ret = btrfs_del_leaf(trans, root, path, leaf); | |
4025 | BUG_ON(ret); | |
4026 | free_extent_buffer(leaf); | |
4027 | } else { | |
4028 | /* if we're still in the path, make sure | |
4029 | * we're dirty. Otherwise, one of the | |
4030 | * push_leaf functions must have already | |
4031 | * dirtied this buffer | |
4032 | */ | |
4033 | if (path->nodes[0] == leaf) | |
4034 | btrfs_mark_buffer_dirty(leaf); | |
4035 | free_extent_buffer(leaf); | |
4036 | } | |
4037 | } else { | |
4038 | btrfs_mark_buffer_dirty(leaf); | |
4039 | } | |
4040 | } | |
4041 | return ret; | |
4042 | } | |
4043 | ||
4044 | /* | |
4045 | * search the tree again to find a leaf with lesser keys | |
4046 | * returns 0 if it found something or 1 if there are no lesser leaves. | |
4047 | * returns < 0 on io errors. | |
4048 | * | |
4049 | * This may release the path, and so you may lose any locks held at the | |
4050 | * time you call it. | |
4051 | */ | |
4052 | int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path) | |
4053 | { | |
4054 | struct btrfs_key key; | |
4055 | struct btrfs_disk_key found_key; | |
4056 | int ret; | |
4057 | ||
4058 | btrfs_item_key_to_cpu(path->nodes[0], &key, 0); | |
4059 | ||
4060 | if (key.offset > 0) | |
4061 | key.offset--; | |
4062 | else if (key.type > 0) | |
4063 | key.type--; | |
4064 | else if (key.objectid > 0) | |
4065 | key.objectid--; | |
4066 | else | |
4067 | return 1; | |
4068 | ||
4069 | btrfs_release_path(root, path); | |
4070 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); | |
4071 | if (ret < 0) | |
4072 | return ret; | |
4073 | btrfs_item_key(path->nodes[0], &found_key, 0); | |
4074 | ret = comp_keys(&found_key, &key); | |
4075 | if (ret < 0) | |
4076 | return 0; | |
4077 | return 1; | |
4078 | } | |
4079 | ||
4080 | /* | |
4081 | * A helper function to walk down the tree starting at min_key, and looking | |
4082 | * for nodes or leaves that are either in cache or have a minimum | |
4083 | * transaction id. This is used by the btree defrag code, and tree logging | |
4084 | * | |
4085 | * This does not cow, but it does stuff the starting key it finds back | |
4086 | * into min_key, so you can call btrfs_search_slot with cow=1 on the | |
4087 | * key and get a writable path. | |
4088 | * | |
4089 | * This does lock as it descends, and path->keep_locks should be set | |
4090 | * to 1 by the caller. | |
4091 | * | |
4092 | * This honors path->lowest_level to prevent descent past a given level | |
4093 | * of the tree. | |
4094 | * | |
4095 | * min_trans indicates the oldest transaction that you are interested | |
4096 | * in walking through. Any nodes or leaves older than min_trans are | |
4097 | * skipped over (without reading them). | |
4098 | * | |
4099 | * returns zero if something useful was found, < 0 on error and 1 if there | |
4100 | * was nothing in the tree that matched the search criteria. | |
4101 | */ | |
4102 | int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key, | |
4103 | struct btrfs_key *max_key, | |
4104 | struct btrfs_path *path, int cache_only, | |
4105 | u64 min_trans) | |
4106 | { | |
4107 | struct extent_buffer *cur; | |
4108 | struct btrfs_key found_key; | |
4109 | int slot; | |
4110 | int sret; | |
4111 | u32 nritems; | |
4112 | int level; | |
4113 | int ret = 1; | |
4114 | ||
4115 | WARN_ON(!path->keep_locks); | |
4116 | again: | |
4117 | cur = btrfs_lock_root_node(root); | |
4118 | level = btrfs_header_level(cur); | |
4119 | WARN_ON(path->nodes[level]); | |
4120 | path->nodes[level] = cur; | |
4121 | path->locks[level] = 1; | |
4122 | ||
4123 | if (btrfs_header_generation(cur) < min_trans) { | |
4124 | ret = 1; | |
4125 | goto out; | |
4126 | } | |
4127 | while (1) { | |
4128 | nritems = btrfs_header_nritems(cur); | |
4129 | level = btrfs_header_level(cur); | |
4130 | sret = bin_search(cur, min_key, level, &slot); | |
4131 | ||
4132 | /* at the lowest level, we're done, setup the path and exit */ | |
4133 | if (level == path->lowest_level) { | |
4134 | if (slot >= nritems) | |
4135 | goto find_next_key; | |
4136 | ret = 0; | |
4137 | path->slots[level] = slot; | |
4138 | btrfs_item_key_to_cpu(cur, &found_key, slot); | |
4139 | goto out; | |
4140 | } | |
4141 | if (sret && slot > 0) | |
4142 | slot--; | |
4143 | /* | |
4144 | * check this node pointer against the cache_only and | |
4145 | * min_trans parameters. If it isn't in cache or is too | |
4146 | * old, skip to the next one. | |
4147 | */ | |
4148 | while (slot < nritems) { | |
4149 | u64 blockptr; | |
4150 | u64 gen; | |
4151 | struct extent_buffer *tmp; | |
4152 | struct btrfs_disk_key disk_key; | |
4153 | ||
4154 | blockptr = btrfs_node_blockptr(cur, slot); | |
4155 | gen = btrfs_node_ptr_generation(cur, slot); | |
4156 | if (gen < min_trans) { | |
4157 | slot++; | |
4158 | continue; | |
4159 | } | |
4160 | if (!cache_only) | |
4161 | break; | |
4162 | ||
4163 | if (max_key) { | |
4164 | btrfs_node_key(cur, &disk_key, slot); | |
4165 | if (comp_keys(&disk_key, max_key) >= 0) { | |
4166 | ret = 1; | |
4167 | goto out; | |
4168 | } | |
4169 | } | |
4170 | ||
4171 | tmp = btrfs_find_tree_block(root, blockptr, | |
4172 | btrfs_level_size(root, level - 1)); | |
4173 | ||
4174 | if (tmp && btrfs_buffer_uptodate(tmp, gen)) { | |
4175 | free_extent_buffer(tmp); | |
4176 | break; | |
4177 | } | |
4178 | if (tmp) | |
4179 | free_extent_buffer(tmp); | |
4180 | slot++; | |
4181 | } | |
4182 | find_next_key: | |
4183 | /* | |
4184 | * we didn't find a candidate key in this node, walk forward | |
4185 | * and find another one | |
4186 | */ | |
4187 | if (slot >= nritems) { | |
4188 | path->slots[level] = slot; | |
4189 | btrfs_set_path_blocking(path); | |
4190 | sret = btrfs_find_next_key(root, path, min_key, level, | |
4191 | cache_only, min_trans); | |
4192 | if (sret == 0) { | |
4193 | btrfs_release_path(root, path); | |
4194 | goto again; | |
4195 | } else { | |
4196 | goto out; | |
4197 | } | |
4198 | } | |
4199 | /* save our key for returning back */ | |
4200 | btrfs_node_key_to_cpu(cur, &found_key, slot); | |
4201 | path->slots[level] = slot; | |
4202 | if (level == path->lowest_level) { | |
4203 | ret = 0; | |
4204 | unlock_up(path, level, 1); | |
4205 | goto out; | |
4206 | } | |
4207 | btrfs_set_path_blocking(path); | |
4208 | cur = read_node_slot(root, cur, slot); | |
4209 | ||
4210 | btrfs_tree_lock(cur); | |
4211 | ||
4212 | path->locks[level - 1] = 1; | |
4213 | path->nodes[level - 1] = cur; | |
4214 | unlock_up(path, level, 1); | |
4215 | btrfs_clear_path_blocking(path, NULL); | |
4216 | } | |
4217 | out: | |
4218 | if (ret == 0) | |
4219 | memcpy(min_key, &found_key, sizeof(found_key)); | |
4220 | btrfs_set_path_blocking(path); | |
4221 | return ret; | |
4222 | } | |
4223 | ||
4224 | /* | |
4225 | * this is similar to btrfs_next_leaf, but does not try to preserve | |
4226 | * and fixup the path. It looks for and returns the next key in the | |
4227 | * tree based on the current path and the cache_only and min_trans | |
4228 | * parameters. | |
4229 | * | |
4230 | * 0 is returned if another key is found, < 0 if there are any errors | |
4231 | * and 1 is returned if there are no higher keys in the tree | |
4232 | * | |
4233 | * path->keep_locks should be set to 1 on the search made before | |
4234 | * calling this function. | |
4235 | */ | |
4236 | int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path, | |
4237 | struct btrfs_key *key, int level, | |
4238 | int cache_only, u64 min_trans) | |
4239 | { | |
4240 | int slot; | |
4241 | struct extent_buffer *c; | |
4242 | ||
4243 | WARN_ON(!path->keep_locks); | |
4244 | while (level < BTRFS_MAX_LEVEL) { | |
4245 | if (!path->nodes[level]) | |
4246 | return 1; | |
4247 | ||
4248 | slot = path->slots[level] + 1; | |
4249 | c = path->nodes[level]; | |
4250 | next: | |
4251 | if (slot >= btrfs_header_nritems(c)) { | |
4252 | int ret; | |
4253 | int orig_lowest; | |
4254 | struct btrfs_key cur_key; | |
4255 | if (level + 1 >= BTRFS_MAX_LEVEL || | |
4256 | !path->nodes[level + 1]) | |
4257 | return 1; | |
4258 | ||
4259 | if (path->locks[level + 1]) { | |
4260 | level++; | |
4261 | continue; | |
4262 | } | |
4263 | ||
4264 | slot = btrfs_header_nritems(c) - 1; | |
4265 | if (level == 0) | |
4266 | btrfs_item_key_to_cpu(c, &cur_key, slot); | |
4267 | else | |
4268 | btrfs_node_key_to_cpu(c, &cur_key, slot); | |
4269 | ||
4270 | orig_lowest = path->lowest_level; | |
4271 | btrfs_release_path(root, path); | |
4272 | path->lowest_level = level; | |
4273 | ret = btrfs_search_slot(NULL, root, &cur_key, path, | |
4274 | 0, 0); | |
4275 | path->lowest_level = orig_lowest; | |
4276 | if (ret < 0) | |
4277 | return ret; | |
4278 | ||
4279 | c = path->nodes[level]; | |
4280 | slot = path->slots[level]; | |
4281 | if (ret == 0) | |
4282 | slot++; | |
4283 | goto next; | |
4284 | } | |
4285 | ||
4286 | if (level == 0) | |
4287 | btrfs_item_key_to_cpu(c, key, slot); | |
4288 | else { | |
4289 | u64 blockptr = btrfs_node_blockptr(c, slot); | |
4290 | u64 gen = btrfs_node_ptr_generation(c, slot); | |
4291 | ||
4292 | if (cache_only) { | |
4293 | struct extent_buffer *cur; | |
4294 | cur = btrfs_find_tree_block(root, blockptr, | |
4295 | btrfs_level_size(root, level - 1)); | |
4296 | if (!cur || !btrfs_buffer_uptodate(cur, gen)) { | |
4297 | slot++; | |
4298 | if (cur) | |
4299 | free_extent_buffer(cur); | |
4300 | goto next; | |
4301 | } | |
4302 | free_extent_buffer(cur); | |
4303 | } | |
4304 | if (gen < min_trans) { | |
4305 | slot++; | |
4306 | goto next; | |
4307 | } | |
4308 | btrfs_node_key_to_cpu(c, key, slot); | |
4309 | } | |
4310 | return 0; | |
4311 | } | |
4312 | return 1; | |
4313 | } | |
4314 | ||
4315 | /* | |
4316 | * search the tree again to find a leaf with greater keys | |
4317 | * returns 0 if it found something or 1 if there are no greater leaves. | |
4318 | * returns < 0 on io errors. | |
4319 | */ | |
4320 | int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path) | |
4321 | { | |
4322 | int slot; | |
4323 | int level; | |
4324 | struct extent_buffer *c; | |
4325 | struct extent_buffer *next; | |
4326 | struct btrfs_key key; | |
4327 | u32 nritems; | |
4328 | int ret; | |
4329 | int old_spinning = path->leave_spinning; | |
4330 | int force_blocking = 0; | |
4331 | ||
4332 | nritems = btrfs_header_nritems(path->nodes[0]); | |
4333 | if (nritems == 0) | |
4334 | return 1; | |
4335 | ||
4336 | /* | |
4337 | * we take the blocks in an order that upsets lockdep. Using | |
4338 | * blocking mode is the only way around it. | |
4339 | */ | |
4340 | #ifdef CONFIG_DEBUG_LOCK_ALLOC | |
4341 | force_blocking = 1; | |
4342 | #endif | |
4343 | ||
4344 | btrfs_item_key_to_cpu(path->nodes[0], &key, nritems - 1); | |
4345 | again: | |
4346 | level = 1; | |
4347 | next = NULL; | |
4348 | btrfs_release_path(root, path); | |
4349 | ||
4350 | path->keep_locks = 1; | |
4351 | ||
4352 | if (!force_blocking) | |
4353 | path->leave_spinning = 1; | |
4354 | ||
4355 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); | |
4356 | path->keep_locks = 0; | |
4357 | ||
4358 | if (ret < 0) | |
4359 | return ret; | |
4360 | ||
4361 | nritems = btrfs_header_nritems(path->nodes[0]); | |
4362 | /* | |
4363 | * by releasing the path above we dropped all our locks. A balance | |
4364 | * could have added more items next to the key that used to be | |
4365 | * at the very end of the block. So, check again here and | |
4366 | * advance the path if there are now more items available. | |
4367 | */ | |
4368 | if (nritems > 0 && path->slots[0] < nritems - 1) { | |
4369 | if (ret == 0) | |
4370 | path->slots[0]++; | |
4371 | ret = 0; | |
4372 | goto done; | |
4373 | } | |
4374 | ||
4375 | while (level < BTRFS_MAX_LEVEL) { | |
4376 | if (!path->nodes[level]) { | |
4377 | ret = 1; | |
4378 | goto done; | |
4379 | } | |
4380 | ||
4381 | slot = path->slots[level] + 1; | |
4382 | c = path->nodes[level]; | |
4383 | if (slot >= btrfs_header_nritems(c)) { | |
4384 | level++; | |
4385 | if (level == BTRFS_MAX_LEVEL) { | |
4386 | ret = 1; | |
4387 | goto done; | |
4388 | } | |
4389 | continue; | |
4390 | } | |
4391 | ||
4392 | if (next) { | |
4393 | btrfs_tree_unlock(next); | |
4394 | free_extent_buffer(next); | |
4395 | } | |
4396 | ||
4397 | next = c; | |
4398 | ret = read_block_for_search(NULL, root, path, &next, level, | |
4399 | slot, &key); | |
4400 | if (ret == -EAGAIN) | |
4401 | goto again; | |
4402 | ||
4403 | if (ret < 0) { | |
4404 | btrfs_release_path(root, path); | |
4405 | goto done; | |
4406 | } | |
4407 | ||
4408 | if (!path->skip_locking) { | |
4409 | ret = btrfs_try_spin_lock(next); | |
4410 | if (!ret) { | |
4411 | btrfs_set_path_blocking(path); | |
4412 | btrfs_tree_lock(next); | |
4413 | if (!force_blocking) | |
4414 | btrfs_clear_path_blocking(path, next); | |
4415 | } | |
4416 | if (force_blocking) | |
4417 | btrfs_set_lock_blocking(next); | |
4418 | } | |
4419 | break; | |
4420 | } | |
4421 | path->slots[level] = slot; | |
4422 | while (1) { | |
4423 | level--; | |
4424 | c = path->nodes[level]; | |
4425 | if (path->locks[level]) | |
4426 | btrfs_tree_unlock(c); | |
4427 | ||
4428 | free_extent_buffer(c); | |
4429 | path->nodes[level] = next; | |
4430 | path->slots[level] = 0; | |
4431 | if (!path->skip_locking) | |
4432 | path->locks[level] = 1; | |
4433 | ||
4434 | if (!level) | |
4435 | break; | |
4436 | ||
4437 | ret = read_block_for_search(NULL, root, path, &next, level, | |
4438 | 0, &key); | |
4439 | if (ret == -EAGAIN) | |
4440 | goto again; | |
4441 | ||
4442 | if (ret < 0) { | |
4443 | btrfs_release_path(root, path); | |
4444 | goto done; | |
4445 | } | |
4446 | ||
4447 | if (!path->skip_locking) { | |
4448 | btrfs_assert_tree_locked(path->nodes[level]); | |
4449 | ret = btrfs_try_spin_lock(next); | |
4450 | if (!ret) { | |
4451 | btrfs_set_path_blocking(path); | |
4452 | btrfs_tree_lock(next); | |
4453 | if (!force_blocking) | |
4454 | btrfs_clear_path_blocking(path, next); | |
4455 | } | |
4456 | if (force_blocking) | |
4457 | btrfs_set_lock_blocking(next); | |
4458 | } | |
4459 | } | |
4460 | ret = 0; | |
4461 | done: | |
4462 | unlock_up(path, 0, 1); | |
4463 | path->leave_spinning = old_spinning; | |
4464 | if (!old_spinning) | |
4465 | btrfs_set_path_blocking(path); | |
4466 | ||
4467 | return ret; | |
4468 | } | |
4469 | ||
4470 | /* | |
4471 | * this uses btrfs_prev_leaf to walk backwards in the tree, and keeps | |
4472 | * searching until it gets past min_objectid or finds an item of 'type' | |
4473 | * | |
4474 | * returns 0 if something is found, 1 if nothing was found and < 0 on error | |
4475 | */ | |
4476 | int btrfs_previous_item(struct btrfs_root *root, | |
4477 | struct btrfs_path *path, u64 min_objectid, | |
4478 | int type) | |
4479 | { | |
4480 | struct btrfs_key found_key; | |
4481 | struct extent_buffer *leaf; | |
4482 | u32 nritems; | |
4483 | int ret; | |
4484 | ||
4485 | while (1) { | |
4486 | if (path->slots[0] == 0) { | |
4487 | btrfs_set_path_blocking(path); | |
4488 | ret = btrfs_prev_leaf(root, path); | |
4489 | if (ret != 0) | |
4490 | return ret; | |
4491 | } else { | |
4492 | path->slots[0]--; | |
4493 | } | |
4494 | leaf = path->nodes[0]; | |
4495 | nritems = btrfs_header_nritems(leaf); | |
4496 | if (nritems == 0) | |
4497 | return 1; | |
4498 | if (path->slots[0] == nritems) | |
4499 | path->slots[0]--; | |
4500 | ||
4501 | btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); | |
4502 | if (found_key.objectid < min_objectid) | |
4503 | break; | |
4504 | if (found_key.type == type) | |
4505 | return 0; | |
4506 | if (found_key.objectid == min_objectid && | |
4507 | found_key.type < type) | |
4508 | break; | |
4509 | } | |
4510 | return 1; | |
4511 | } |