Commit | Line | Data |
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6cbd5570 | 1 | /* |
d352ac68 | 2 | * Copyright (C) 2007,2008 Oracle. All rights reserved. |
6cbd5570 CM |
3 | * |
4 | * This program is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU General Public | |
6 | * License v2 as published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, | |
9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
11 | * General Public License for more details. | |
12 | * | |
13 | * You should have received a copy of the GNU General Public | |
14 | * License along with this program; if not, write to the | |
15 | * Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
16 | * Boston, MA 021110-1307, USA. | |
17 | */ | |
18 | ||
a6b6e75e | 19 | #include <linux/sched.h> |
5a0e3ad6 | 20 | #include <linux/slab.h> |
eb60ceac CM |
21 | #include "ctree.h" |
22 | #include "disk-io.h" | |
7f5c1516 | 23 | #include "transaction.h" |
5f39d397 | 24 | #include "print-tree.h" |
925baedd | 25 | #include "locking.h" |
9a8dd150 | 26 | |
e089f05c CM |
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 | |
d4dbff95 | 30 | *root, struct btrfs_key *ins_key, |
cc0c5538 | 31 | struct btrfs_path *path, int data_size, int extend); |
5f39d397 CM |
32 | static int push_node_left(struct btrfs_trans_handle *trans, |
33 | struct btrfs_root *root, struct extent_buffer *dst, | |
971a1f66 | 34 | struct extent_buffer *src, int empty); |
5f39d397 CM |
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); | |
e089f05c CM |
39 | static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
40 | struct btrfs_path *path, int level, int slot); | |
ad48fd75 YZ |
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 | ||
d97e63b6 | 46 | |
df24a2b9 | 47 | struct btrfs_path *btrfs_alloc_path(void) |
2c90e5d6 | 48 | { |
df24a2b9 | 49 | struct btrfs_path *path; |
e00f7308 JM |
50 | path = kmem_cache_zalloc(btrfs_path_cachep, GFP_NOFS); |
51 | if (path) | |
2cc58cf2 | 52 | path->reada = 1; |
df24a2b9 | 53 | return path; |
2c90e5d6 CM |
54 | } |
55 | ||
b4ce94de CM |
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. | |
4008c04a CM |
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 | |
b4ce94de | 76 | */ |
4008c04a CM |
77 | noinline void btrfs_clear_path_blocking(struct btrfs_path *p, |
78 | struct extent_buffer *held) | |
b4ce94de CM |
79 | { |
80 | int i; | |
4008c04a CM |
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--) { | |
b4ce94de CM |
95 | if (p->nodes[i] && p->locks[i]) |
96 | btrfs_clear_lock_blocking(p->nodes[i]); | |
97 | } | |
4008c04a CM |
98 | |
99 | #ifdef CONFIG_DEBUG_LOCK_ALLOC | |
100 | if (held) | |
101 | btrfs_clear_lock_blocking(held); | |
102 | #endif | |
b4ce94de CM |
103 | } |
104 | ||
d352ac68 | 105 | /* this also releases the path */ |
df24a2b9 | 106 | void btrfs_free_path(struct btrfs_path *p) |
be0e5c09 | 107 | { |
ff175d57 JJ |
108 | if (!p) |
109 | return; | |
df24a2b9 CM |
110 | btrfs_release_path(NULL, p); |
111 | kmem_cache_free(btrfs_path_cachep, p); | |
be0e5c09 CM |
112 | } |
113 | ||
d352ac68 CM |
114 | /* |
115 | * path release drops references on the extent buffers in the path | |
116 | * and it drops any locks held by this path | |
117 | * | |
118 | * It is safe to call this on paths that no locks or extent buffers held. | |
119 | */ | |
d397712b | 120 | noinline void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p) |
eb60ceac CM |
121 | { |
122 | int i; | |
a2135011 | 123 | |
234b63a0 | 124 | for (i = 0; i < BTRFS_MAX_LEVEL; i++) { |
3f157a2f | 125 | p->slots[i] = 0; |
eb60ceac | 126 | if (!p->nodes[i]) |
925baedd CM |
127 | continue; |
128 | if (p->locks[i]) { | |
129 | btrfs_tree_unlock(p->nodes[i]); | |
130 | p->locks[i] = 0; | |
131 | } | |
5f39d397 | 132 | free_extent_buffer(p->nodes[i]); |
3f157a2f | 133 | p->nodes[i] = NULL; |
eb60ceac CM |
134 | } |
135 | } | |
136 | ||
d352ac68 CM |
137 | /* |
138 | * safely gets a reference on the root node of a tree. A lock | |
139 | * is not taken, so a concurrent writer may put a different node | |
140 | * at the root of the tree. See btrfs_lock_root_node for the | |
141 | * looping required. | |
142 | * | |
143 | * The extent buffer returned by this has a reference taken, so | |
144 | * it won't disappear. It may stop being the root of the tree | |
145 | * at any time because there are no locks held. | |
146 | */ | |
925baedd CM |
147 | struct extent_buffer *btrfs_root_node(struct btrfs_root *root) |
148 | { | |
149 | struct extent_buffer *eb; | |
150 | spin_lock(&root->node_lock); | |
151 | eb = root->node; | |
152 | extent_buffer_get(eb); | |
153 | spin_unlock(&root->node_lock); | |
154 | return eb; | |
155 | } | |
156 | ||
d352ac68 CM |
157 | /* loop around taking references on and locking the root node of the |
158 | * tree until you end up with a lock on the root. A locked buffer | |
159 | * is returned, with a reference held. | |
160 | */ | |
925baedd CM |
161 | struct extent_buffer *btrfs_lock_root_node(struct btrfs_root *root) |
162 | { | |
163 | struct extent_buffer *eb; | |
164 | ||
d397712b | 165 | while (1) { |
925baedd CM |
166 | eb = btrfs_root_node(root); |
167 | btrfs_tree_lock(eb); | |
168 | ||
169 | spin_lock(&root->node_lock); | |
170 | if (eb == root->node) { | |
171 | spin_unlock(&root->node_lock); | |
172 | break; | |
173 | } | |
174 | spin_unlock(&root->node_lock); | |
175 | ||
176 | btrfs_tree_unlock(eb); | |
177 | free_extent_buffer(eb); | |
178 | } | |
179 | return eb; | |
180 | } | |
181 | ||
d352ac68 CM |
182 | /* cowonly root (everything not a reference counted cow subvolume), just get |
183 | * put onto a simple dirty list. transaction.c walks this to make sure they | |
184 | * get properly updated on disk. | |
185 | */ | |
0b86a832 CM |
186 | static void add_root_to_dirty_list(struct btrfs_root *root) |
187 | { | |
188 | if (root->track_dirty && list_empty(&root->dirty_list)) { | |
189 | list_add(&root->dirty_list, | |
190 | &root->fs_info->dirty_cowonly_roots); | |
191 | } | |
192 | } | |
193 | ||
d352ac68 CM |
194 | /* |
195 | * used by snapshot creation to make a copy of a root for a tree with | |
196 | * a given objectid. The buffer with the new root node is returned in | |
197 | * cow_ret, and this func returns zero on success or a negative error code. | |
198 | */ | |
be20aa9d CM |
199 | int btrfs_copy_root(struct btrfs_trans_handle *trans, |
200 | struct btrfs_root *root, | |
201 | struct extent_buffer *buf, | |
202 | struct extent_buffer **cow_ret, u64 new_root_objectid) | |
203 | { | |
204 | struct extent_buffer *cow; | |
be20aa9d CM |
205 | int ret = 0; |
206 | int level; | |
5d4f98a2 | 207 | struct btrfs_disk_key disk_key; |
be20aa9d CM |
208 | |
209 | WARN_ON(root->ref_cows && trans->transid != | |
210 | root->fs_info->running_transaction->transid); | |
211 | WARN_ON(root->ref_cows && trans->transid != root->last_trans); | |
212 | ||
213 | level = btrfs_header_level(buf); | |
5d4f98a2 YZ |
214 | if (level == 0) |
215 | btrfs_item_key(buf, &disk_key, 0); | |
216 | else | |
217 | btrfs_node_key(buf, &disk_key, 0); | |
31840ae1 | 218 | |
5d4f98a2 YZ |
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)) | |
be20aa9d CM |
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); | |
5d4f98a2 YZ |
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); | |
be20aa9d | 235 | |
2b82032c YZ |
236 | write_extent_buffer(cow, root->fs_info->fsid, |
237 | (unsigned long)btrfs_header_fsid(cow), | |
238 | BTRFS_FSID_SIZE); | |
239 | ||
be20aa9d | 240 | WARN_ON(btrfs_header_generation(buf) > trans->transid); |
5d4f98a2 YZ |
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); | |
4aec2b52 | 245 | |
be20aa9d CM |
246 | if (ret) |
247 | return ret; | |
248 | ||
249 | btrfs_mark_buffer_dirty(cow); | |
250 | *cow_ret = cow; | |
251 | return 0; | |
252 | } | |
253 | ||
5d4f98a2 YZ |
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, | |
f0486c68 YZ |
283 | struct extent_buffer *cow, |
284 | int *last_ref) | |
5d4f98a2 YZ |
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); | |
f0486c68 | 370 | *last_ref = 1; |
5d4f98a2 YZ |
371 | } |
372 | return 0; | |
373 | } | |
374 | ||
d352ac68 | 375 | /* |
d397712b CM |
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. | |
d352ac68 CM |
380 | * |
381 | * search_start -- an allocation hint for the new block | |
382 | * | |
d397712b CM |
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. | |
d352ac68 | 386 | */ |
d397712b | 387 | static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans, |
5f39d397 CM |
388 | struct btrfs_root *root, |
389 | struct extent_buffer *buf, | |
390 | struct extent_buffer *parent, int parent_slot, | |
391 | struct extent_buffer **cow_ret, | |
9fa8cfe7 | 392 | u64 search_start, u64 empty_size) |
02217ed2 | 393 | { |
5d4f98a2 | 394 | struct btrfs_disk_key disk_key; |
5f39d397 | 395 | struct extent_buffer *cow; |
7bb86316 | 396 | int level; |
f0486c68 | 397 | int last_ref = 0; |
925baedd | 398 | int unlock_orig = 0; |
5d4f98a2 | 399 | u64 parent_start; |
7bb86316 | 400 | |
925baedd CM |
401 | if (*cow_ret == buf) |
402 | unlock_orig = 1; | |
403 | ||
b9447ef8 | 404 | btrfs_assert_tree_locked(buf); |
925baedd | 405 | |
7bb86316 CM |
406 | WARN_ON(root->ref_cows && trans->transid != |
407 | root->fs_info->running_transaction->transid); | |
6702ed49 | 408 | WARN_ON(root->ref_cows && trans->transid != root->last_trans); |
5f39d397 | 409 | |
7bb86316 | 410 | level = btrfs_header_level(buf); |
31840ae1 | 411 | |
5d4f98a2 YZ |
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); | |
54aa1f4d CM |
428 | if (IS_ERR(cow)) |
429 | return PTR_ERR(cow); | |
6702ed49 | 430 | |
b4ce94de CM |
431 | /* cow is set to blocking by btrfs_init_new_buffer */ |
432 | ||
5f39d397 | 433 | copy_extent_buffer(cow, buf, 0, 0, cow->len); |
db94535d | 434 | btrfs_set_header_bytenr(cow, cow->start); |
5f39d397 | 435 | btrfs_set_header_generation(cow, trans->transid); |
5d4f98a2 YZ |
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); | |
6702ed49 | 443 | |
2b82032c YZ |
444 | write_extent_buffer(cow, root->fs_info->fsid, |
445 | (unsigned long)btrfs_header_fsid(cow), | |
446 | BTRFS_FSID_SIZE); | |
447 | ||
f0486c68 | 448 | update_ref_for_cow(trans, root, buf, cow, &last_ref); |
1a40e23b | 449 | |
3fd0a558 YZ |
450 | if (root->ref_cows) |
451 | btrfs_reloc_cow_block(trans, root, buf, cow); | |
452 | ||
02217ed2 | 453 | if (buf == root->node) { |
925baedd | 454 | WARN_ON(parent && parent != buf); |
5d4f98a2 YZ |
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; | |
925baedd CM |
460 | |
461 | spin_lock(&root->node_lock); | |
02217ed2 | 462 | root->node = cow; |
5f39d397 | 463 | extent_buffer_get(cow); |
925baedd CM |
464 | spin_unlock(&root->node_lock); |
465 | ||
f0486c68 YZ |
466 | btrfs_free_tree_block(trans, root, buf, parent_start, |
467 | last_ref); | |
5f39d397 | 468 | free_extent_buffer(buf); |
0b86a832 | 469 | add_root_to_dirty_list(root); |
02217ed2 | 470 | } else { |
5d4f98a2 YZ |
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)); | |
5f39d397 | 477 | btrfs_set_node_blockptr(parent, parent_slot, |
db94535d | 478 | cow->start); |
74493f7a CM |
479 | btrfs_set_node_ptr_generation(parent, parent_slot, |
480 | trans->transid); | |
d6025579 | 481 | btrfs_mark_buffer_dirty(parent); |
f0486c68 YZ |
482 | btrfs_free_tree_block(trans, root, buf, parent_start, |
483 | last_ref); | |
02217ed2 | 484 | } |
925baedd CM |
485 | if (unlock_orig) |
486 | btrfs_tree_unlock(buf); | |
5f39d397 | 487 | free_extent_buffer(buf); |
ccd467d6 | 488 | btrfs_mark_buffer_dirty(cow); |
2c90e5d6 | 489 | *cow_ret = cow; |
02217ed2 CM |
490 | return 0; |
491 | } | |
492 | ||
5d4f98a2 YZ |
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 | ||
d352ac68 CM |
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 | */ | |
d397712b | 510 | noinline int btrfs_cow_block(struct btrfs_trans_handle *trans, |
5f39d397 CM |
511 | struct btrfs_root *root, struct extent_buffer *buf, |
512 | struct extent_buffer *parent, int parent_slot, | |
9fa8cfe7 | 513 | struct extent_buffer **cow_ret) |
6702ed49 CM |
514 | { |
515 | u64 search_start; | |
f510cfec | 516 | int ret; |
dc17ff8f | 517 | |
6702ed49 | 518 | if (trans->transaction != root->fs_info->running_transaction) { |
d397712b CM |
519 | printk(KERN_CRIT "trans %llu running %llu\n", |
520 | (unsigned long long)trans->transid, | |
521 | (unsigned long long) | |
6702ed49 CM |
522 | root->fs_info->running_transaction->transid); |
523 | WARN_ON(1); | |
524 | } | |
525 | if (trans->transid != root->fs_info->generation) { | |
d397712b CM |
526 | printk(KERN_CRIT "trans %llu running %llu\n", |
527 | (unsigned long long)trans->transid, | |
528 | (unsigned long long)root->fs_info->generation); | |
6702ed49 CM |
529 | WARN_ON(1); |
530 | } | |
dc17ff8f | 531 | |
5d4f98a2 | 532 | if (!should_cow_block(trans, root, buf)) { |
6702ed49 CM |
533 | *cow_ret = buf; |
534 | return 0; | |
535 | } | |
c487685d | 536 | |
0b86a832 | 537 | search_start = buf->start & ~((u64)(1024 * 1024 * 1024) - 1); |
b4ce94de CM |
538 | |
539 | if (parent) | |
540 | btrfs_set_lock_blocking(parent); | |
541 | btrfs_set_lock_blocking(buf); | |
542 | ||
f510cfec | 543 | ret = __btrfs_cow_block(trans, root, buf, parent, |
9fa8cfe7 | 544 | parent_slot, cow_ret, search_start, 0); |
f510cfec | 545 | return ret; |
6702ed49 CM |
546 | } |
547 | ||
d352ac68 CM |
548 | /* |
549 | * helper function for defrag to decide if two blocks pointed to by a | |
550 | * node are actually close by | |
551 | */ | |
6b80053d | 552 | static int close_blocks(u64 blocknr, u64 other, u32 blocksize) |
6702ed49 | 553 | { |
6b80053d | 554 | if (blocknr < other && other - (blocknr + blocksize) < 32768) |
6702ed49 | 555 | return 1; |
6b80053d | 556 | if (blocknr > other && blocknr - (other + blocksize) < 32768) |
6702ed49 CM |
557 | return 1; |
558 | return 0; | |
559 | } | |
560 | ||
081e9573 CM |
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 | ||
20736aba | 570 | return btrfs_comp_cpu_keys(&k1, k2); |
081e9573 CM |
571 | } |
572 | ||
f3465ca4 JB |
573 | /* |
574 | * same as comp_keys only with two btrfs_key's | |
575 | */ | |
5d4f98a2 | 576 | int btrfs_comp_cpu_keys(struct btrfs_key *k1, struct btrfs_key *k2) |
f3465ca4 JB |
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 | } | |
081e9573 | 592 | |
d352ac68 CM |
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 | */ | |
6702ed49 | 598 | int btrfs_realloc_node(struct btrfs_trans_handle *trans, |
5f39d397 | 599 | struct btrfs_root *root, struct extent_buffer *parent, |
a6b6e75e CM |
600 | int start_slot, int cache_only, u64 *last_ret, |
601 | struct btrfs_key *progress) | |
6702ed49 | 602 | { |
6b80053d | 603 | struct extent_buffer *cur; |
6702ed49 | 604 | u64 blocknr; |
ca7a79ad | 605 | u64 gen; |
e9d0b13b CM |
606 | u64 search_start = *last_ret; |
607 | u64 last_block = 0; | |
6702ed49 CM |
608 | u64 other; |
609 | u32 parent_nritems; | |
6702ed49 CM |
610 | int end_slot; |
611 | int i; | |
612 | int err = 0; | |
f2183bde | 613 | int parent_level; |
6b80053d CM |
614 | int uptodate; |
615 | u32 blocksize; | |
081e9573 CM |
616 | int progress_passed = 0; |
617 | struct btrfs_disk_key disk_key; | |
6702ed49 | 618 | |
5708b959 CM |
619 | parent_level = btrfs_header_level(parent); |
620 | if (cache_only && parent_level != 1) | |
621 | return 0; | |
622 | ||
d397712b | 623 | if (trans->transaction != root->fs_info->running_transaction) |
6702ed49 | 624 | WARN_ON(1); |
d397712b | 625 | if (trans->transid != root->fs_info->generation) |
6702ed49 | 626 | WARN_ON(1); |
86479a04 | 627 | |
6b80053d | 628 | parent_nritems = btrfs_header_nritems(parent); |
6b80053d | 629 | blocksize = btrfs_level_size(root, parent_level - 1); |
6702ed49 CM |
630 | end_slot = parent_nritems; |
631 | ||
632 | if (parent_nritems == 1) | |
633 | return 0; | |
634 | ||
b4ce94de CM |
635 | btrfs_set_lock_blocking(parent); |
636 | ||
6702ed49 CM |
637 | for (i = start_slot; i < end_slot; i++) { |
638 | int close = 1; | |
a6b6e75e | 639 | |
5708b959 CM |
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 | } | |
081e9573 CM |
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; | |
6b80053d | 653 | blocknr = btrfs_node_blockptr(parent, i); |
ca7a79ad | 654 | gen = btrfs_node_ptr_generation(parent, i); |
e9d0b13b CM |
655 | if (last_block == 0) |
656 | last_block = blocknr; | |
5708b959 | 657 | |
6702ed49 | 658 | if (i > 0) { |
6b80053d CM |
659 | other = btrfs_node_blockptr(parent, i - 1); |
660 | close = close_blocks(blocknr, other, blocksize); | |
6702ed49 | 661 | } |
0ef3e66b | 662 | if (!close && i < end_slot - 2) { |
6b80053d CM |
663 | other = btrfs_node_blockptr(parent, i + 1); |
664 | close = close_blocks(blocknr, other, blocksize); | |
6702ed49 | 665 | } |
e9d0b13b CM |
666 | if (close) { |
667 | last_block = blocknr; | |
6702ed49 | 668 | continue; |
e9d0b13b | 669 | } |
5708b959 CM |
670 | if (parent->map_token) { |
671 | unmap_extent_buffer(parent, parent->map_token, | |
672 | KM_USER1); | |
673 | parent->map_token = NULL; | |
674 | } | |
6702ed49 | 675 | |
6b80053d CM |
676 | cur = btrfs_find_tree_block(root, blocknr, blocksize); |
677 | if (cur) | |
1259ab75 | 678 | uptodate = btrfs_buffer_uptodate(cur, gen); |
6b80053d CM |
679 | else |
680 | uptodate = 0; | |
5708b959 | 681 | if (!cur || !uptodate) { |
6702ed49 | 682 | if (cache_only) { |
6b80053d | 683 | free_extent_buffer(cur); |
6702ed49 CM |
684 | continue; |
685 | } | |
6b80053d CM |
686 | if (!cur) { |
687 | cur = read_tree_block(root, blocknr, | |
ca7a79ad | 688 | blocksize, gen); |
6b80053d | 689 | } else if (!uptodate) { |
ca7a79ad | 690 | btrfs_read_buffer(cur, gen); |
f2183bde | 691 | } |
6702ed49 | 692 | } |
e9d0b13b | 693 | if (search_start == 0) |
6b80053d | 694 | search_start = last_block; |
e9d0b13b | 695 | |
e7a84565 | 696 | btrfs_tree_lock(cur); |
b4ce94de | 697 | btrfs_set_lock_blocking(cur); |
6b80053d | 698 | err = __btrfs_cow_block(trans, root, cur, parent, i, |
e7a84565 | 699 | &cur, search_start, |
6b80053d | 700 | min(16 * blocksize, |
9fa8cfe7 | 701 | (end_slot - i) * blocksize)); |
252c38f0 | 702 | if (err) { |
e7a84565 | 703 | btrfs_tree_unlock(cur); |
6b80053d | 704 | free_extent_buffer(cur); |
6702ed49 | 705 | break; |
252c38f0 | 706 | } |
e7a84565 CM |
707 | search_start = cur->start; |
708 | last_block = cur->start; | |
f2183bde | 709 | *last_ret = search_start; |
e7a84565 CM |
710 | btrfs_tree_unlock(cur); |
711 | free_extent_buffer(cur); | |
6702ed49 | 712 | } |
5708b959 CM |
713 | if (parent->map_token) { |
714 | unmap_extent_buffer(parent, parent->map_token, | |
715 | KM_USER1); | |
716 | parent->map_token = NULL; | |
717 | } | |
6702ed49 CM |
718 | return err; |
719 | } | |
720 | ||
74123bd7 CM |
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 | */ | |
123abc88 | 726 | static inline unsigned int leaf_data_end(struct btrfs_root *root, |
5f39d397 | 727 | struct extent_buffer *leaf) |
be0e5c09 | 728 | { |
5f39d397 | 729 | u32 nr = btrfs_header_nritems(leaf); |
be0e5c09 | 730 | if (nr == 0) |
123abc88 | 731 | return BTRFS_LEAF_DATA_SIZE(root); |
5f39d397 | 732 | return btrfs_item_offset_nr(leaf, nr - 1); |
be0e5c09 CM |
733 | } |
734 | ||
d352ac68 CM |
735 | /* |
736 | * extra debugging checks to make sure all the items in a key are | |
737 | * well formed and in the proper order | |
738 | */ | |
123abc88 CM |
739 | static int check_node(struct btrfs_root *root, struct btrfs_path *path, |
740 | int level) | |
aa5d6bed | 741 | { |
5f39d397 CM |
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; | |
aa5d6bed | 746 | int parent_slot; |
8d7be552 CM |
747 | int slot; |
748 | struct btrfs_key cpukey; | |
5f39d397 | 749 | u32 nritems = btrfs_header_nritems(node); |
aa5d6bed CM |
750 | |
751 | if (path->nodes[level + 1]) | |
5f39d397 | 752 | parent = path->nodes[level + 1]; |
a1f39630 | 753 | |
8d7be552 | 754 | slot = path->slots[level]; |
7518a238 CM |
755 | BUG_ON(nritems == 0); |
756 | if (parent) { | |
a1f39630 | 757 | parent_slot = path->slots[level + 1]; |
5f39d397 CM |
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, | |
e2fa7227 | 761 | sizeof(struct btrfs_disk_key))); |
1d4f8a0c | 762 | BUG_ON(btrfs_node_blockptr(parent, parent_slot) != |
db94535d | 763 | btrfs_header_bytenr(node)); |
aa5d6bed | 764 | } |
123abc88 | 765 | BUG_ON(nritems > BTRFS_NODEPTRS_PER_BLOCK(root)); |
8d7be552 | 766 | if (slot != 0) { |
5f39d397 CM |
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); | |
8d7be552 CM |
770 | } |
771 | if (slot < nritems - 1) { | |
5f39d397 CM |
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); | |
aa5d6bed CM |
775 | } |
776 | return 0; | |
777 | } | |
778 | ||
d352ac68 CM |
779 | /* |
780 | * extra checking to make sure all the items in a leaf are | |
781 | * well formed and in the proper order | |
782 | */ | |
123abc88 CM |
783 | static int check_leaf(struct btrfs_root *root, struct btrfs_path *path, |
784 | int level) | |
aa5d6bed | 785 | { |
5f39d397 CM |
786 | struct extent_buffer *leaf = path->nodes[level]; |
787 | struct extent_buffer *parent = NULL; | |
aa5d6bed | 788 | int parent_slot; |
8d7be552 | 789 | struct btrfs_key cpukey; |
5f39d397 CM |
790 | struct btrfs_disk_key parent_key; |
791 | struct btrfs_disk_key leaf_key; | |
792 | int slot = path->slots[0]; | |
8d7be552 | 793 | |
5f39d397 | 794 | u32 nritems = btrfs_header_nritems(leaf); |
aa5d6bed CM |
795 | |
796 | if (path->nodes[level + 1]) | |
5f39d397 | 797 | parent = path->nodes[level + 1]; |
7518a238 CM |
798 | |
799 | if (nritems == 0) | |
800 | return 0; | |
801 | ||
802 | if (parent) { | |
a1f39630 | 803 | parent_slot = path->slots[level + 1]; |
5f39d397 CM |
804 | btrfs_node_key(parent, &parent_key, parent_slot); |
805 | btrfs_item_key(leaf, &leaf_key, 0); | |
6702ed49 | 806 | |
5f39d397 | 807 | BUG_ON(memcmp(&parent_key, &leaf_key, |
e2fa7227 | 808 | sizeof(struct btrfs_disk_key))); |
1d4f8a0c | 809 | BUG_ON(btrfs_node_blockptr(parent, parent_slot) != |
db94535d | 810 | btrfs_header_bytenr(leaf)); |
5f39d397 | 811 | } |
5f39d397 CM |
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); | |
d397712b | 817 | printk(KERN_CRIT "slot %d offset bad key\n", slot); |
5f39d397 CM |
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); | |
d397712b | 823 | printk(KERN_CRIT "slot %d offset bad\n", slot); |
5f39d397 CM |
824 | BUG_ON(1); |
825 | } | |
8d7be552 CM |
826 | } |
827 | if (slot < nritems - 1) { | |
5f39d397 CM |
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); | |
d397712b | 834 | printk(KERN_CRIT "slot %d offset bad\n", slot); |
5f39d397 CM |
835 | BUG_ON(1); |
836 | } | |
aa5d6bed | 837 | } |
5f39d397 CM |
838 | BUG_ON(btrfs_item_offset_nr(leaf, 0) + |
839 | btrfs_item_size_nr(leaf, 0) != BTRFS_LEAF_DATA_SIZE(root)); | |
aa5d6bed CM |
840 | return 0; |
841 | } | |
842 | ||
d397712b | 843 | static noinline int check_block(struct btrfs_root *root, |
98ed5174 | 844 | struct btrfs_path *path, int level) |
aa5d6bed | 845 | { |
85d824c4 | 846 | return 0; |
aa5d6bed | 847 | if (level == 0) |
123abc88 CM |
848 | return check_leaf(root, path, level); |
849 | return check_node(root, path, level); | |
aa5d6bed CM |
850 | } |
851 | ||
74123bd7 | 852 | /* |
5f39d397 CM |
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 | * | |
74123bd7 CM |
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 | */ | |
e02119d5 CM |
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) | |
be0e5c09 CM |
866 | { |
867 | int low = 0; | |
868 | int high = max; | |
869 | int mid; | |
870 | int ret; | |
479965d6 | 871 | struct btrfs_disk_key *tmp = NULL; |
5f39d397 CM |
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; | |
479965d6 | 878 | int err; |
be0e5c09 | 879 | |
d397712b | 880 | while (low < high) { |
be0e5c09 | 881 | mid = (low + high) / 2; |
5f39d397 CM |
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) { | |
479965d6 | 887 | if (map_token) { |
5f39d397 | 888 | unmap_extent_buffer(eb, map_token, KM_USER0); |
479965d6 CM |
889 | map_token = NULL; |
890 | } | |
934d375b CM |
891 | |
892 | err = map_private_extent_buffer(eb, offset, | |
479965d6 CM |
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 | } | |
5f39d397 | 905 | |
5f39d397 CM |
906 | } else { |
907 | tmp = (struct btrfs_disk_key *)(kaddr + offset - | |
908 | map_start); | |
909 | } | |
be0e5c09 CM |
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; | |
479965d6 CM |
918 | if (map_token) |
919 | unmap_extent_buffer(eb, map_token, KM_USER0); | |
be0e5c09 CM |
920 | return 0; |
921 | } | |
922 | } | |
923 | *slot = low; | |
5f39d397 CM |
924 | if (map_token) |
925 | unmap_extent_buffer(eb, map_token, KM_USER0); | |
be0e5c09 CM |
926 | return 1; |
927 | } | |
928 | ||
97571fd0 CM |
929 | /* |
930 | * simple bin_search frontend that does the right thing for | |
931 | * leaves vs nodes | |
932 | */ | |
5f39d397 CM |
933 | static int bin_search(struct extent_buffer *eb, struct btrfs_key *key, |
934 | int level, int *slot) | |
be0e5c09 | 935 | { |
5f39d397 CM |
936 | if (level == 0) { |
937 | return generic_bin_search(eb, | |
938 | offsetof(struct btrfs_leaf, items), | |
0783fcfc | 939 | sizeof(struct btrfs_item), |
5f39d397 | 940 | key, btrfs_header_nritems(eb), |
7518a238 | 941 | slot); |
be0e5c09 | 942 | } else { |
5f39d397 CM |
943 | return generic_bin_search(eb, |
944 | offsetof(struct btrfs_node, ptrs), | |
123abc88 | 945 | sizeof(struct btrfs_key_ptr), |
5f39d397 | 946 | key, btrfs_header_nritems(eb), |
7518a238 | 947 | slot); |
be0e5c09 CM |
948 | } |
949 | return -1; | |
950 | } | |
951 | ||
5d4f98a2 YZ |
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 | ||
f0486c68 YZ |
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 | ||
d352ac68 CM |
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 | */ | |
e02119d5 | 978 | static noinline struct extent_buffer *read_node_slot(struct btrfs_root *root, |
5f39d397 | 979 | struct extent_buffer *parent, int slot) |
bb803951 | 980 | { |
ca7a79ad | 981 | int level = btrfs_header_level(parent); |
bb803951 CM |
982 | if (slot < 0) |
983 | return NULL; | |
5f39d397 | 984 | if (slot >= btrfs_header_nritems(parent)) |
bb803951 | 985 | return NULL; |
ca7a79ad CM |
986 | |
987 | BUG_ON(level == 0); | |
988 | ||
db94535d | 989 | return read_tree_block(root, btrfs_node_blockptr(parent, slot), |
ca7a79ad CM |
990 | btrfs_level_size(root, level - 1), |
991 | btrfs_node_ptr_generation(parent, slot)); | |
bb803951 CM |
992 | } |
993 | ||
d352ac68 CM |
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 | */ | |
e02119d5 | 999 | static noinline int balance_level(struct btrfs_trans_handle *trans, |
98ed5174 CM |
1000 | struct btrfs_root *root, |
1001 | struct btrfs_path *path, int level) | |
bb803951 | 1002 | { |
5f39d397 CM |
1003 | struct extent_buffer *right = NULL; |
1004 | struct extent_buffer *mid; | |
1005 | struct extent_buffer *left = NULL; | |
1006 | struct extent_buffer *parent = NULL; | |
bb803951 CM |
1007 | int ret = 0; |
1008 | int wret; | |
1009 | int pslot; | |
bb803951 | 1010 | int orig_slot = path->slots[level]; |
79f95c82 | 1011 | u64 orig_ptr; |
bb803951 CM |
1012 | |
1013 | if (level == 0) | |
1014 | return 0; | |
1015 | ||
5f39d397 | 1016 | mid = path->nodes[level]; |
b4ce94de | 1017 | |
925baedd | 1018 | WARN_ON(!path->locks[level]); |
7bb86316 CM |
1019 | WARN_ON(btrfs_header_generation(mid) != trans->transid); |
1020 | ||
1d4f8a0c | 1021 | orig_ptr = btrfs_node_blockptr(mid, orig_slot); |
79f95c82 | 1022 | |
234b63a0 | 1023 | if (level < BTRFS_MAX_LEVEL - 1) |
5f39d397 | 1024 | parent = path->nodes[level + 1]; |
bb803951 CM |
1025 | pslot = path->slots[level + 1]; |
1026 | ||
40689478 CM |
1027 | /* |
1028 | * deal with the case where there is only one pointer in the root | |
1029 | * by promoting the node below to a root | |
1030 | */ | |
5f39d397 CM |
1031 | if (!parent) { |
1032 | struct extent_buffer *child; | |
bb803951 | 1033 | |
5f39d397 | 1034 | if (btrfs_header_nritems(mid) != 1) |
bb803951 CM |
1035 | return 0; |
1036 | ||
1037 | /* promote the child to a root */ | |
5f39d397 | 1038 | child = read_node_slot(root, mid, 0); |
7951f3ce | 1039 | BUG_ON(!child); |
925baedd | 1040 | btrfs_tree_lock(child); |
b4ce94de | 1041 | btrfs_set_lock_blocking(child); |
9fa8cfe7 | 1042 | ret = btrfs_cow_block(trans, root, child, mid, 0, &child); |
f0486c68 YZ |
1043 | if (ret) { |
1044 | btrfs_tree_unlock(child); | |
1045 | free_extent_buffer(child); | |
1046 | goto enospc; | |
1047 | } | |
2f375ab9 | 1048 | |
925baedd | 1049 | spin_lock(&root->node_lock); |
bb803951 | 1050 | root->node = child; |
925baedd CM |
1051 | spin_unlock(&root->node_lock); |
1052 | ||
0b86a832 | 1053 | add_root_to_dirty_list(root); |
925baedd | 1054 | btrfs_tree_unlock(child); |
b4ce94de | 1055 | |
925baedd | 1056 | path->locks[level] = 0; |
bb803951 | 1057 | path->nodes[level] = NULL; |
5f39d397 | 1058 | clean_tree_block(trans, root, mid); |
925baedd | 1059 | btrfs_tree_unlock(mid); |
bb803951 | 1060 | /* once for the path */ |
5f39d397 | 1061 | free_extent_buffer(mid); |
f0486c68 YZ |
1062 | |
1063 | root_sub_used(root, mid->len); | |
1064 | btrfs_free_tree_block(trans, root, mid, 0, 1); | |
bb803951 | 1065 | /* once for the root ptr */ |
5f39d397 | 1066 | free_extent_buffer(mid); |
f0486c68 | 1067 | return 0; |
bb803951 | 1068 | } |
5f39d397 | 1069 | if (btrfs_header_nritems(mid) > |
123abc88 | 1070 | BTRFS_NODEPTRS_PER_BLOCK(root) / 4) |
bb803951 CM |
1071 | return 0; |
1072 | ||
559af821 | 1073 | btrfs_header_nritems(mid); |
54aa1f4d | 1074 | |
5f39d397 CM |
1075 | left = read_node_slot(root, parent, pslot - 1); |
1076 | if (left) { | |
925baedd | 1077 | btrfs_tree_lock(left); |
b4ce94de | 1078 | btrfs_set_lock_blocking(left); |
5f39d397 | 1079 | wret = btrfs_cow_block(trans, root, left, |
9fa8cfe7 | 1080 | parent, pslot - 1, &left); |
54aa1f4d CM |
1081 | if (wret) { |
1082 | ret = wret; | |
1083 | goto enospc; | |
1084 | } | |
2cc58cf2 | 1085 | } |
5f39d397 CM |
1086 | right = read_node_slot(root, parent, pslot + 1); |
1087 | if (right) { | |
925baedd | 1088 | btrfs_tree_lock(right); |
b4ce94de | 1089 | btrfs_set_lock_blocking(right); |
5f39d397 | 1090 | wret = btrfs_cow_block(trans, root, right, |
9fa8cfe7 | 1091 | parent, pslot + 1, &right); |
2cc58cf2 CM |
1092 | if (wret) { |
1093 | ret = wret; | |
1094 | goto enospc; | |
1095 | } | |
1096 | } | |
1097 | ||
1098 | /* first, try to make some room in the middle buffer */ | |
5f39d397 CM |
1099 | if (left) { |
1100 | orig_slot += btrfs_header_nritems(left); | |
bce4eae9 | 1101 | wret = push_node_left(trans, root, left, mid, 1); |
79f95c82 CM |
1102 | if (wret < 0) |
1103 | ret = wret; | |
559af821 | 1104 | btrfs_header_nritems(mid); |
bb803951 | 1105 | } |
79f95c82 CM |
1106 | |
1107 | /* | |
1108 | * then try to empty the right most buffer into the middle | |
1109 | */ | |
5f39d397 | 1110 | if (right) { |
971a1f66 | 1111 | wret = push_node_left(trans, root, mid, right, 1); |
54aa1f4d | 1112 | if (wret < 0 && wret != -ENOSPC) |
79f95c82 | 1113 | ret = wret; |
5f39d397 | 1114 | if (btrfs_header_nritems(right) == 0) { |
5f39d397 | 1115 | clean_tree_block(trans, root, right); |
925baedd | 1116 | btrfs_tree_unlock(right); |
e089f05c CM |
1117 | wret = del_ptr(trans, root, path, level + 1, pslot + |
1118 | 1); | |
bb803951 CM |
1119 | if (wret) |
1120 | ret = wret; | |
f0486c68 YZ |
1121 | root_sub_used(root, right->len); |
1122 | btrfs_free_tree_block(trans, root, right, 0, 1); | |
1123 | free_extent_buffer(right); | |
1124 | right = NULL; | |
bb803951 | 1125 | } else { |
5f39d397 CM |
1126 | struct btrfs_disk_key right_key; |
1127 | btrfs_node_key(right, &right_key, 0); | |
1128 | btrfs_set_node_key(parent, &right_key, pslot + 1); | |
1129 | btrfs_mark_buffer_dirty(parent); | |
bb803951 CM |
1130 | } |
1131 | } | |
5f39d397 | 1132 | if (btrfs_header_nritems(mid) == 1) { |
79f95c82 CM |
1133 | /* |
1134 | * we're not allowed to leave a node with one item in the | |
1135 | * tree during a delete. A deletion from lower in the tree | |
1136 | * could try to delete the only pointer in this node. | |
1137 | * So, pull some keys from the left. | |
1138 | * There has to be a left pointer at this point because | |
1139 | * otherwise we would have pulled some pointers from the | |
1140 | * right | |
1141 | */ | |
5f39d397 CM |
1142 | BUG_ON(!left); |
1143 | wret = balance_node_right(trans, root, mid, left); | |
54aa1f4d | 1144 | if (wret < 0) { |
79f95c82 | 1145 | ret = wret; |
54aa1f4d CM |
1146 | goto enospc; |
1147 | } | |
bce4eae9 CM |
1148 | if (wret == 1) { |
1149 | wret = push_node_left(trans, root, left, mid, 1); | |
1150 | if (wret < 0) | |
1151 | ret = wret; | |
1152 | } | |
79f95c82 CM |
1153 | BUG_ON(wret == 1); |
1154 | } | |
5f39d397 | 1155 | if (btrfs_header_nritems(mid) == 0) { |
5f39d397 | 1156 | clean_tree_block(trans, root, mid); |
925baedd | 1157 | btrfs_tree_unlock(mid); |
e089f05c | 1158 | wret = del_ptr(trans, root, path, level + 1, pslot); |
bb803951 CM |
1159 | if (wret) |
1160 | ret = wret; | |
f0486c68 YZ |
1161 | root_sub_used(root, mid->len); |
1162 | btrfs_free_tree_block(trans, root, mid, 0, 1); | |
1163 | free_extent_buffer(mid); | |
1164 | mid = NULL; | |
79f95c82 CM |
1165 | } else { |
1166 | /* update the parent key to reflect our changes */ | |
5f39d397 CM |
1167 | struct btrfs_disk_key mid_key; |
1168 | btrfs_node_key(mid, &mid_key, 0); | |
1169 | btrfs_set_node_key(parent, &mid_key, pslot); | |
1170 | btrfs_mark_buffer_dirty(parent); | |
79f95c82 | 1171 | } |
bb803951 | 1172 | |
79f95c82 | 1173 | /* update the path */ |
5f39d397 CM |
1174 | if (left) { |
1175 | if (btrfs_header_nritems(left) > orig_slot) { | |
1176 | extent_buffer_get(left); | |
925baedd | 1177 | /* left was locked after cow */ |
5f39d397 | 1178 | path->nodes[level] = left; |
bb803951 CM |
1179 | path->slots[level + 1] -= 1; |
1180 | path->slots[level] = orig_slot; | |
925baedd CM |
1181 | if (mid) { |
1182 | btrfs_tree_unlock(mid); | |
5f39d397 | 1183 | free_extent_buffer(mid); |
925baedd | 1184 | } |
bb803951 | 1185 | } else { |
5f39d397 | 1186 | orig_slot -= btrfs_header_nritems(left); |
bb803951 CM |
1187 | path->slots[level] = orig_slot; |
1188 | } | |
1189 | } | |
79f95c82 | 1190 | /* double check we haven't messed things up */ |
123abc88 | 1191 | check_block(root, path, level); |
e20d96d6 | 1192 | if (orig_ptr != |
5f39d397 | 1193 | btrfs_node_blockptr(path->nodes[level], path->slots[level])) |
79f95c82 | 1194 | BUG(); |
54aa1f4d | 1195 | enospc: |
925baedd CM |
1196 | if (right) { |
1197 | btrfs_tree_unlock(right); | |
5f39d397 | 1198 | free_extent_buffer(right); |
925baedd CM |
1199 | } |
1200 | if (left) { | |
1201 | if (path->nodes[level] != left) | |
1202 | btrfs_tree_unlock(left); | |
5f39d397 | 1203 | free_extent_buffer(left); |
925baedd | 1204 | } |
bb803951 CM |
1205 | return ret; |
1206 | } | |
1207 | ||
d352ac68 CM |
1208 | /* Node balancing for insertion. Here we only split or push nodes around |
1209 | * when they are completely full. This is also done top down, so we | |
1210 | * have to be pessimistic. | |
1211 | */ | |
d397712b | 1212 | static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans, |
98ed5174 CM |
1213 | struct btrfs_root *root, |
1214 | struct btrfs_path *path, int level) | |
e66f709b | 1215 | { |
5f39d397 CM |
1216 | struct extent_buffer *right = NULL; |
1217 | struct extent_buffer *mid; | |
1218 | struct extent_buffer *left = NULL; | |
1219 | struct extent_buffer *parent = NULL; | |
e66f709b CM |
1220 | int ret = 0; |
1221 | int wret; | |
1222 | int pslot; | |
1223 | int orig_slot = path->slots[level]; | |
e66f709b CM |
1224 | |
1225 | if (level == 0) | |
1226 | return 1; | |
1227 | ||
5f39d397 | 1228 | mid = path->nodes[level]; |
7bb86316 | 1229 | WARN_ON(btrfs_header_generation(mid) != trans->transid); |
e66f709b CM |
1230 | |
1231 | if (level < BTRFS_MAX_LEVEL - 1) | |
5f39d397 | 1232 | parent = path->nodes[level + 1]; |
e66f709b CM |
1233 | pslot = path->slots[level + 1]; |
1234 | ||
5f39d397 | 1235 | if (!parent) |
e66f709b | 1236 | return 1; |
e66f709b | 1237 | |
5f39d397 | 1238 | left = read_node_slot(root, parent, pslot - 1); |
e66f709b CM |
1239 | |
1240 | /* first, try to make some room in the middle buffer */ | |
5f39d397 | 1241 | if (left) { |
e66f709b | 1242 | u32 left_nr; |
925baedd CM |
1243 | |
1244 | btrfs_tree_lock(left); | |
b4ce94de CM |
1245 | btrfs_set_lock_blocking(left); |
1246 | ||
5f39d397 | 1247 | left_nr = btrfs_header_nritems(left); |
33ade1f8 CM |
1248 | if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) { |
1249 | wret = 1; | |
1250 | } else { | |
5f39d397 | 1251 | ret = btrfs_cow_block(trans, root, left, parent, |
9fa8cfe7 | 1252 | pslot - 1, &left); |
54aa1f4d CM |
1253 | if (ret) |
1254 | wret = 1; | |
1255 | else { | |
54aa1f4d | 1256 | wret = push_node_left(trans, root, |
971a1f66 | 1257 | left, mid, 0); |
54aa1f4d | 1258 | } |
33ade1f8 | 1259 | } |
e66f709b CM |
1260 | if (wret < 0) |
1261 | ret = wret; | |
1262 | if (wret == 0) { | |
5f39d397 | 1263 | struct btrfs_disk_key disk_key; |
e66f709b | 1264 | orig_slot += left_nr; |
5f39d397 CM |
1265 | btrfs_node_key(mid, &disk_key, 0); |
1266 | btrfs_set_node_key(parent, &disk_key, pslot); | |
1267 | btrfs_mark_buffer_dirty(parent); | |
1268 | if (btrfs_header_nritems(left) > orig_slot) { | |
1269 | path->nodes[level] = left; | |
e66f709b CM |
1270 | path->slots[level + 1] -= 1; |
1271 | path->slots[level] = orig_slot; | |
925baedd | 1272 | btrfs_tree_unlock(mid); |
5f39d397 | 1273 | free_extent_buffer(mid); |
e66f709b CM |
1274 | } else { |
1275 | orig_slot -= | |
5f39d397 | 1276 | btrfs_header_nritems(left); |
e66f709b | 1277 | path->slots[level] = orig_slot; |
925baedd | 1278 | btrfs_tree_unlock(left); |
5f39d397 | 1279 | free_extent_buffer(left); |
e66f709b | 1280 | } |
e66f709b CM |
1281 | return 0; |
1282 | } | |
925baedd | 1283 | btrfs_tree_unlock(left); |
5f39d397 | 1284 | free_extent_buffer(left); |
e66f709b | 1285 | } |
925baedd | 1286 | right = read_node_slot(root, parent, pslot + 1); |
e66f709b CM |
1287 | |
1288 | /* | |
1289 | * then try to empty the right most buffer into the middle | |
1290 | */ | |
5f39d397 | 1291 | if (right) { |
33ade1f8 | 1292 | u32 right_nr; |
b4ce94de | 1293 | |
925baedd | 1294 | btrfs_tree_lock(right); |
b4ce94de CM |
1295 | btrfs_set_lock_blocking(right); |
1296 | ||
5f39d397 | 1297 | right_nr = btrfs_header_nritems(right); |
33ade1f8 CM |
1298 | if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) { |
1299 | wret = 1; | |
1300 | } else { | |
5f39d397 CM |
1301 | ret = btrfs_cow_block(trans, root, right, |
1302 | parent, pslot + 1, | |
9fa8cfe7 | 1303 | &right); |
54aa1f4d CM |
1304 | if (ret) |
1305 | wret = 1; | |
1306 | else { | |
54aa1f4d | 1307 | wret = balance_node_right(trans, root, |
5f39d397 | 1308 | right, mid); |
54aa1f4d | 1309 | } |
33ade1f8 | 1310 | } |
e66f709b CM |
1311 | if (wret < 0) |
1312 | ret = wret; | |
1313 | if (wret == 0) { | |
5f39d397 CM |
1314 | struct btrfs_disk_key disk_key; |
1315 | ||
1316 | btrfs_node_key(right, &disk_key, 0); | |
1317 | btrfs_set_node_key(parent, &disk_key, pslot + 1); | |
1318 | btrfs_mark_buffer_dirty(parent); | |
1319 | ||
1320 | if (btrfs_header_nritems(mid) <= orig_slot) { | |
1321 | path->nodes[level] = right; | |
e66f709b CM |
1322 | path->slots[level + 1] += 1; |
1323 | path->slots[level] = orig_slot - | |
5f39d397 | 1324 | btrfs_header_nritems(mid); |
925baedd | 1325 | btrfs_tree_unlock(mid); |
5f39d397 | 1326 | free_extent_buffer(mid); |
e66f709b | 1327 | } else { |
925baedd | 1328 | btrfs_tree_unlock(right); |
5f39d397 | 1329 | free_extent_buffer(right); |
e66f709b | 1330 | } |
e66f709b CM |
1331 | return 0; |
1332 | } | |
925baedd | 1333 | btrfs_tree_unlock(right); |
5f39d397 | 1334 | free_extent_buffer(right); |
e66f709b | 1335 | } |
e66f709b CM |
1336 | return 1; |
1337 | } | |
1338 | ||
3c69faec | 1339 | /* |
d352ac68 CM |
1340 | * readahead one full node of leaves, finding things that are close |
1341 | * to the block in 'slot', and triggering ra on them. | |
3c69faec | 1342 | */ |
c8c42864 CM |
1343 | static void reada_for_search(struct btrfs_root *root, |
1344 | struct btrfs_path *path, | |
1345 | int level, int slot, u64 objectid) | |
3c69faec | 1346 | { |
5f39d397 | 1347 | struct extent_buffer *node; |
01f46658 | 1348 | struct btrfs_disk_key disk_key; |
3c69faec | 1349 | u32 nritems; |
3c69faec | 1350 | u64 search; |
a7175319 | 1351 | u64 target; |
6b80053d | 1352 | u64 nread = 0; |
3c69faec | 1353 | int direction = path->reada; |
5f39d397 | 1354 | struct extent_buffer *eb; |
6b80053d CM |
1355 | u32 nr; |
1356 | u32 blocksize; | |
1357 | u32 nscan = 0; | |
db94535d | 1358 | |
a6b6e75e | 1359 | if (level != 1) |
6702ed49 CM |
1360 | return; |
1361 | ||
1362 | if (!path->nodes[level]) | |
3c69faec CM |
1363 | return; |
1364 | ||
5f39d397 | 1365 | node = path->nodes[level]; |
925baedd | 1366 | |
3c69faec | 1367 | search = btrfs_node_blockptr(node, slot); |
6b80053d CM |
1368 | blocksize = btrfs_level_size(root, level - 1); |
1369 | eb = btrfs_find_tree_block(root, search, blocksize); | |
5f39d397 CM |
1370 | if (eb) { |
1371 | free_extent_buffer(eb); | |
3c69faec CM |
1372 | return; |
1373 | } | |
1374 | ||
a7175319 | 1375 | target = search; |
6b80053d | 1376 | |
5f39d397 | 1377 | nritems = btrfs_header_nritems(node); |
6b80053d | 1378 | nr = slot; |
d397712b | 1379 | while (1) { |
6b80053d CM |
1380 | if (direction < 0) { |
1381 | if (nr == 0) | |
1382 | break; | |
1383 | nr--; | |
1384 | } else if (direction > 0) { | |
1385 | nr++; | |
1386 | if (nr >= nritems) | |
1387 | break; | |
3c69faec | 1388 | } |
01f46658 CM |
1389 | if (path->reada < 0 && objectid) { |
1390 | btrfs_node_key(node, &disk_key, nr); | |
1391 | if (btrfs_disk_key_objectid(&disk_key) != objectid) | |
1392 | break; | |
1393 | } | |
6b80053d | 1394 | search = btrfs_node_blockptr(node, nr); |
a7175319 CM |
1395 | if ((search <= target && target - search <= 65536) || |
1396 | (search > target && search - target <= 65536)) { | |
ca7a79ad CM |
1397 | readahead_tree_block(root, search, blocksize, |
1398 | btrfs_node_ptr_generation(node, nr)); | |
6b80053d CM |
1399 | nread += blocksize; |
1400 | } | |
1401 | nscan++; | |
a7175319 | 1402 | if ((nread > 65536 || nscan > 32)) |
6b80053d | 1403 | break; |
3c69faec CM |
1404 | } |
1405 | } | |
925baedd | 1406 | |
b4ce94de CM |
1407 | /* |
1408 | * returns -EAGAIN if it had to drop the path, or zero if everything was in | |
1409 | * cache | |
1410 | */ | |
1411 | static noinline int reada_for_balance(struct btrfs_root *root, | |
1412 | struct btrfs_path *path, int level) | |
1413 | { | |
1414 | int slot; | |
1415 | int nritems; | |
1416 | struct extent_buffer *parent; | |
1417 | struct extent_buffer *eb; | |
1418 | u64 gen; | |
1419 | u64 block1 = 0; | |
1420 | u64 block2 = 0; | |
1421 | int ret = 0; | |
1422 | int blocksize; | |
1423 | ||
8c594ea8 | 1424 | parent = path->nodes[level + 1]; |
b4ce94de CM |
1425 | if (!parent) |
1426 | return 0; | |
1427 | ||
1428 | nritems = btrfs_header_nritems(parent); | |
8c594ea8 | 1429 | slot = path->slots[level + 1]; |
b4ce94de CM |
1430 | blocksize = btrfs_level_size(root, level); |
1431 | ||
1432 | if (slot > 0) { | |
1433 | block1 = btrfs_node_blockptr(parent, slot - 1); | |
1434 | gen = btrfs_node_ptr_generation(parent, slot - 1); | |
1435 | eb = btrfs_find_tree_block(root, block1, blocksize); | |
1436 | if (eb && btrfs_buffer_uptodate(eb, gen)) | |
1437 | block1 = 0; | |
1438 | free_extent_buffer(eb); | |
1439 | } | |
8c594ea8 | 1440 | if (slot + 1 < nritems) { |
b4ce94de CM |
1441 | block2 = btrfs_node_blockptr(parent, slot + 1); |
1442 | gen = btrfs_node_ptr_generation(parent, slot + 1); | |
1443 | eb = btrfs_find_tree_block(root, block2, blocksize); | |
1444 | if (eb && btrfs_buffer_uptodate(eb, gen)) | |
1445 | block2 = 0; | |
1446 | free_extent_buffer(eb); | |
1447 | } | |
1448 | if (block1 || block2) { | |
1449 | ret = -EAGAIN; | |
8c594ea8 CM |
1450 | |
1451 | /* release the whole path */ | |
b4ce94de | 1452 | btrfs_release_path(root, path); |
8c594ea8 CM |
1453 | |
1454 | /* read the blocks */ | |
b4ce94de CM |
1455 | if (block1) |
1456 | readahead_tree_block(root, block1, blocksize, 0); | |
1457 | if (block2) | |
1458 | readahead_tree_block(root, block2, blocksize, 0); | |
1459 | ||
1460 | if (block1) { | |
1461 | eb = read_tree_block(root, block1, blocksize, 0); | |
1462 | free_extent_buffer(eb); | |
1463 | } | |
8c594ea8 | 1464 | if (block2) { |
b4ce94de CM |
1465 | eb = read_tree_block(root, block2, blocksize, 0); |
1466 | free_extent_buffer(eb); | |
1467 | } | |
1468 | } | |
1469 | return ret; | |
1470 | } | |
1471 | ||
1472 | ||
d352ac68 | 1473 | /* |
d397712b CM |
1474 | * when we walk down the tree, it is usually safe to unlock the higher layers |
1475 | * in the tree. The exceptions are when our path goes through slot 0, because | |
1476 | * operations on the tree might require changing key pointers higher up in the | |
1477 | * tree. | |
d352ac68 | 1478 | * |
d397712b CM |
1479 | * callers might also have set path->keep_locks, which tells this code to keep |
1480 | * the lock if the path points to the last slot in the block. This is part of | |
1481 | * walking through the tree, and selecting the next slot in the higher block. | |
d352ac68 | 1482 | * |
d397712b CM |
1483 | * lowest_unlock sets the lowest level in the tree we're allowed to unlock. so |
1484 | * if lowest_unlock is 1, level 0 won't be unlocked | |
d352ac68 | 1485 | */ |
e02119d5 CM |
1486 | static noinline void unlock_up(struct btrfs_path *path, int level, |
1487 | int lowest_unlock) | |
925baedd CM |
1488 | { |
1489 | int i; | |
1490 | int skip_level = level; | |
051e1b9f | 1491 | int no_skips = 0; |
925baedd CM |
1492 | struct extent_buffer *t; |
1493 | ||
1494 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { | |
1495 | if (!path->nodes[i]) | |
1496 | break; | |
1497 | if (!path->locks[i]) | |
1498 | break; | |
051e1b9f | 1499 | if (!no_skips && path->slots[i] == 0) { |
925baedd CM |
1500 | skip_level = i + 1; |
1501 | continue; | |
1502 | } | |
051e1b9f | 1503 | if (!no_skips && path->keep_locks) { |
925baedd CM |
1504 | u32 nritems; |
1505 | t = path->nodes[i]; | |
1506 | nritems = btrfs_header_nritems(t); | |
051e1b9f | 1507 | if (nritems < 1 || path->slots[i] >= nritems - 1) { |
925baedd CM |
1508 | skip_level = i + 1; |
1509 | continue; | |
1510 | } | |
1511 | } | |
051e1b9f CM |
1512 | if (skip_level < i && i >= lowest_unlock) |
1513 | no_skips = 1; | |
1514 | ||
925baedd CM |
1515 | t = path->nodes[i]; |
1516 | if (i >= lowest_unlock && i > skip_level && path->locks[i]) { | |
1517 | btrfs_tree_unlock(t); | |
1518 | path->locks[i] = 0; | |
1519 | } | |
1520 | } | |
1521 | } | |
1522 | ||
b4ce94de CM |
1523 | /* |
1524 | * This releases any locks held in the path starting at level and | |
1525 | * going all the way up to the root. | |
1526 | * | |
1527 | * btrfs_search_slot will keep the lock held on higher nodes in a few | |
1528 | * corner cases, such as COW of the block at slot zero in the node. This | |
1529 | * ignores those rules, and it should only be called when there are no | |
1530 | * more updates to be done higher up in the tree. | |
1531 | */ | |
1532 | noinline void btrfs_unlock_up_safe(struct btrfs_path *path, int level) | |
1533 | { | |
1534 | int i; | |
1535 | ||
5d4f98a2 | 1536 | if (path->keep_locks) |
b4ce94de CM |
1537 | return; |
1538 | ||
1539 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { | |
1540 | if (!path->nodes[i]) | |
12f4dacc | 1541 | continue; |
b4ce94de | 1542 | if (!path->locks[i]) |
12f4dacc | 1543 | continue; |
b4ce94de CM |
1544 | btrfs_tree_unlock(path->nodes[i]); |
1545 | path->locks[i] = 0; | |
1546 | } | |
1547 | } | |
1548 | ||
c8c42864 CM |
1549 | /* |
1550 | * helper function for btrfs_search_slot. The goal is to find a block | |
1551 | * in cache without setting the path to blocking. If we find the block | |
1552 | * we return zero and the path is unchanged. | |
1553 | * | |
1554 | * If we can't find the block, we set the path blocking and do some | |
1555 | * reada. -EAGAIN is returned and the search must be repeated. | |
1556 | */ | |
1557 | static int | |
1558 | read_block_for_search(struct btrfs_trans_handle *trans, | |
1559 | struct btrfs_root *root, struct btrfs_path *p, | |
1560 | struct extent_buffer **eb_ret, int level, int slot, | |
1561 | struct btrfs_key *key) | |
1562 | { | |
1563 | u64 blocknr; | |
1564 | u64 gen; | |
1565 | u32 blocksize; | |
1566 | struct extent_buffer *b = *eb_ret; | |
1567 | struct extent_buffer *tmp; | |
76a05b35 | 1568 | int ret; |
c8c42864 CM |
1569 | |
1570 | blocknr = btrfs_node_blockptr(b, slot); | |
1571 | gen = btrfs_node_ptr_generation(b, slot); | |
1572 | blocksize = btrfs_level_size(root, level - 1); | |
1573 | ||
1574 | tmp = btrfs_find_tree_block(root, blocknr, blocksize); | |
cb44921a CM |
1575 | if (tmp) { |
1576 | if (btrfs_buffer_uptodate(tmp, 0)) { | |
1577 | if (btrfs_buffer_uptodate(tmp, gen)) { | |
1578 | /* | |
1579 | * we found an up to date block without | |
1580 | * sleeping, return | |
1581 | * right away | |
1582 | */ | |
1583 | *eb_ret = tmp; | |
1584 | return 0; | |
1585 | } | |
1586 | /* the pages were up to date, but we failed | |
1587 | * the generation number check. Do a full | |
1588 | * read for the generation number that is correct. | |
1589 | * We must do this without dropping locks so | |
1590 | * we can trust our generation number | |
1591 | */ | |
1592 | free_extent_buffer(tmp); | |
1593 | tmp = read_tree_block(root, blocknr, blocksize, gen); | |
1594 | if (tmp && btrfs_buffer_uptodate(tmp, gen)) { | |
1595 | *eb_ret = tmp; | |
1596 | return 0; | |
1597 | } | |
1598 | free_extent_buffer(tmp); | |
1599 | btrfs_release_path(NULL, p); | |
1600 | return -EIO; | |
1601 | } | |
c8c42864 CM |
1602 | } |
1603 | ||
1604 | /* | |
1605 | * reduce lock contention at high levels | |
1606 | * of the btree by dropping locks before | |
76a05b35 CM |
1607 | * we read. Don't release the lock on the current |
1608 | * level because we need to walk this node to figure | |
1609 | * out which blocks to read. | |
c8c42864 | 1610 | */ |
8c594ea8 CM |
1611 | btrfs_unlock_up_safe(p, level + 1); |
1612 | btrfs_set_path_blocking(p); | |
1613 | ||
cb44921a | 1614 | free_extent_buffer(tmp); |
c8c42864 CM |
1615 | if (p->reada) |
1616 | reada_for_search(root, p, level, slot, key->objectid); | |
1617 | ||
8c594ea8 | 1618 | btrfs_release_path(NULL, p); |
76a05b35 CM |
1619 | |
1620 | ret = -EAGAIN; | |
5bdd3536 | 1621 | tmp = read_tree_block(root, blocknr, blocksize, 0); |
76a05b35 CM |
1622 | if (tmp) { |
1623 | /* | |
1624 | * If the read above didn't mark this buffer up to date, | |
1625 | * it will never end up being up to date. Set ret to EIO now | |
1626 | * and give up so that our caller doesn't loop forever | |
1627 | * on our EAGAINs. | |
1628 | */ | |
1629 | if (!btrfs_buffer_uptodate(tmp, 0)) | |
1630 | ret = -EIO; | |
c8c42864 | 1631 | free_extent_buffer(tmp); |
76a05b35 CM |
1632 | } |
1633 | return ret; | |
c8c42864 CM |
1634 | } |
1635 | ||
1636 | /* | |
1637 | * helper function for btrfs_search_slot. This does all of the checks | |
1638 | * for node-level blocks and does any balancing required based on | |
1639 | * the ins_len. | |
1640 | * | |
1641 | * If no extra work was required, zero is returned. If we had to | |
1642 | * drop the path, -EAGAIN is returned and btrfs_search_slot must | |
1643 | * start over | |
1644 | */ | |
1645 | static int | |
1646 | setup_nodes_for_search(struct btrfs_trans_handle *trans, | |
1647 | struct btrfs_root *root, struct btrfs_path *p, | |
1648 | struct extent_buffer *b, int level, int ins_len) | |
1649 | { | |
1650 | int ret; | |
1651 | if ((p->search_for_split || ins_len > 0) && btrfs_header_nritems(b) >= | |
1652 | BTRFS_NODEPTRS_PER_BLOCK(root) - 3) { | |
1653 | int sret; | |
1654 | ||
1655 | sret = reada_for_balance(root, p, level); | |
1656 | if (sret) | |
1657 | goto again; | |
1658 | ||
1659 | btrfs_set_path_blocking(p); | |
1660 | sret = split_node(trans, root, p, level); | |
1661 | btrfs_clear_path_blocking(p, NULL); | |
1662 | ||
1663 | BUG_ON(sret > 0); | |
1664 | if (sret) { | |
1665 | ret = sret; | |
1666 | goto done; | |
1667 | } | |
1668 | b = p->nodes[level]; | |
1669 | } else if (ins_len < 0 && btrfs_header_nritems(b) < | |
cfbb9308 | 1670 | BTRFS_NODEPTRS_PER_BLOCK(root) / 2) { |
c8c42864 CM |
1671 | int sret; |
1672 | ||
1673 | sret = reada_for_balance(root, p, level); | |
1674 | if (sret) | |
1675 | goto again; | |
1676 | ||
1677 | btrfs_set_path_blocking(p); | |
1678 | sret = balance_level(trans, root, p, level); | |
1679 | btrfs_clear_path_blocking(p, NULL); | |
1680 | ||
1681 | if (sret) { | |
1682 | ret = sret; | |
1683 | goto done; | |
1684 | } | |
1685 | b = p->nodes[level]; | |
1686 | if (!b) { | |
1687 | btrfs_release_path(NULL, p); | |
1688 | goto again; | |
1689 | } | |
1690 | BUG_ON(btrfs_header_nritems(b) == 1); | |
1691 | } | |
1692 | return 0; | |
1693 | ||
1694 | again: | |
1695 | ret = -EAGAIN; | |
1696 | done: | |
1697 | return ret; | |
1698 | } | |
1699 | ||
74123bd7 CM |
1700 | /* |
1701 | * look for key in the tree. path is filled in with nodes along the way | |
1702 | * if key is found, we return zero and you can find the item in the leaf | |
1703 | * level of the path (level 0) | |
1704 | * | |
1705 | * If the key isn't found, the path points to the slot where it should | |
aa5d6bed CM |
1706 | * be inserted, and 1 is returned. If there are other errors during the |
1707 | * search a negative error number is returned. | |
97571fd0 CM |
1708 | * |
1709 | * if ins_len > 0, nodes and leaves will be split as we walk down the | |
1710 | * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if | |
1711 | * possible) | |
74123bd7 | 1712 | */ |
e089f05c CM |
1713 | int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root |
1714 | *root, struct btrfs_key *key, struct btrfs_path *p, int | |
1715 | ins_len, int cow) | |
be0e5c09 | 1716 | { |
5f39d397 | 1717 | struct extent_buffer *b; |
be0e5c09 CM |
1718 | int slot; |
1719 | int ret; | |
33c66f43 | 1720 | int err; |
be0e5c09 | 1721 | int level; |
925baedd | 1722 | int lowest_unlock = 1; |
9f3a7427 CM |
1723 | u8 lowest_level = 0; |
1724 | ||
6702ed49 | 1725 | lowest_level = p->lowest_level; |
323ac95b | 1726 | WARN_ON(lowest_level && ins_len > 0); |
22b0ebda | 1727 | WARN_ON(p->nodes[0] != NULL); |
25179201 | 1728 | |
925baedd CM |
1729 | if (ins_len < 0) |
1730 | lowest_unlock = 2; | |
65b51a00 | 1731 | |
bb803951 | 1732 | again: |
5d4f98a2 YZ |
1733 | if (p->search_commit_root) { |
1734 | b = root->commit_root; | |
1735 | extent_buffer_get(b); | |
1736 | if (!p->skip_locking) | |
1737 | btrfs_tree_lock(b); | |
1738 | } else { | |
1739 | if (p->skip_locking) | |
1740 | b = btrfs_root_node(root); | |
1741 | else | |
1742 | b = btrfs_lock_root_node(root); | |
1743 | } | |
925baedd | 1744 | |
eb60ceac | 1745 | while (b) { |
5f39d397 | 1746 | level = btrfs_header_level(b); |
65b51a00 CM |
1747 | |
1748 | /* | |
1749 | * setup the path here so we can release it under lock | |
1750 | * contention with the cow code | |
1751 | */ | |
1752 | p->nodes[level] = b; | |
1753 | if (!p->skip_locking) | |
1754 | p->locks[level] = 1; | |
1755 | ||
02217ed2 | 1756 | if (cow) { |
c8c42864 CM |
1757 | /* |
1758 | * if we don't really need to cow this block | |
1759 | * then we don't want to set the path blocking, | |
1760 | * so we test it here | |
1761 | */ | |
5d4f98a2 | 1762 | if (!should_cow_block(trans, root, b)) |
65b51a00 | 1763 | goto cow_done; |
5d4f98a2 | 1764 | |
b4ce94de CM |
1765 | btrfs_set_path_blocking(p); |
1766 | ||
33c66f43 YZ |
1767 | err = btrfs_cow_block(trans, root, b, |
1768 | p->nodes[level + 1], | |
1769 | p->slots[level + 1], &b); | |
1770 | if (err) { | |
33c66f43 | 1771 | ret = err; |
65b51a00 | 1772 | goto done; |
54aa1f4d | 1773 | } |
02217ed2 | 1774 | } |
65b51a00 | 1775 | cow_done: |
02217ed2 | 1776 | BUG_ON(!cow && ins_len); |
5f39d397 | 1777 | if (level != btrfs_header_level(b)) |
2c90e5d6 | 1778 | WARN_ON(1); |
5f39d397 | 1779 | level = btrfs_header_level(b); |
65b51a00 | 1780 | |
eb60ceac | 1781 | p->nodes[level] = b; |
5cd57b2c CM |
1782 | if (!p->skip_locking) |
1783 | p->locks[level] = 1; | |
65b51a00 | 1784 | |
4008c04a | 1785 | btrfs_clear_path_blocking(p, NULL); |
b4ce94de CM |
1786 | |
1787 | /* | |
1788 | * we have a lock on b and as long as we aren't changing | |
1789 | * the tree, there is no way to for the items in b to change. | |
1790 | * It is safe to drop the lock on our parent before we | |
1791 | * go through the expensive btree search on b. | |
1792 | * | |
1793 | * If cow is true, then we might be changing slot zero, | |
1794 | * which may require changing the parent. So, we can't | |
1795 | * drop the lock until after we know which slot we're | |
1796 | * operating on. | |
1797 | */ | |
1798 | if (!cow) | |
1799 | btrfs_unlock_up_safe(p, level + 1); | |
1800 | ||
123abc88 | 1801 | ret = check_block(root, p, level); |
65b51a00 CM |
1802 | if (ret) { |
1803 | ret = -1; | |
1804 | goto done; | |
1805 | } | |
925baedd | 1806 | |
5f39d397 | 1807 | ret = bin_search(b, key, level, &slot); |
b4ce94de | 1808 | |
5f39d397 | 1809 | if (level != 0) { |
33c66f43 YZ |
1810 | int dec = 0; |
1811 | if (ret && slot > 0) { | |
1812 | dec = 1; | |
be0e5c09 | 1813 | slot -= 1; |
33c66f43 | 1814 | } |
be0e5c09 | 1815 | p->slots[level] = slot; |
33c66f43 | 1816 | err = setup_nodes_for_search(trans, root, p, b, level, |
c8c42864 | 1817 | ins_len); |
33c66f43 | 1818 | if (err == -EAGAIN) |
c8c42864 | 1819 | goto again; |
33c66f43 YZ |
1820 | if (err) { |
1821 | ret = err; | |
c8c42864 | 1822 | goto done; |
33c66f43 | 1823 | } |
c8c42864 CM |
1824 | b = p->nodes[level]; |
1825 | slot = p->slots[level]; | |
b4ce94de | 1826 | |
f9efa9c7 CM |
1827 | unlock_up(p, level, lowest_unlock); |
1828 | ||
925baedd | 1829 | if (level == lowest_level) { |
33c66f43 YZ |
1830 | if (dec) |
1831 | p->slots[level]++; | |
5b21f2ed | 1832 | goto done; |
925baedd | 1833 | } |
ca7a79ad | 1834 | |
33c66f43 | 1835 | err = read_block_for_search(trans, root, p, |
c8c42864 | 1836 | &b, level, slot, key); |
33c66f43 | 1837 | if (err == -EAGAIN) |
c8c42864 | 1838 | goto again; |
33c66f43 YZ |
1839 | if (err) { |
1840 | ret = err; | |
76a05b35 | 1841 | goto done; |
33c66f43 | 1842 | } |
76a05b35 | 1843 | |
b4ce94de | 1844 | if (!p->skip_locking) { |
4008c04a | 1845 | btrfs_clear_path_blocking(p, NULL); |
33c66f43 | 1846 | err = btrfs_try_spin_lock(b); |
b4ce94de | 1847 | |
33c66f43 | 1848 | if (!err) { |
b4ce94de CM |
1849 | btrfs_set_path_blocking(p); |
1850 | btrfs_tree_lock(b); | |
4008c04a | 1851 | btrfs_clear_path_blocking(p, b); |
b4ce94de CM |
1852 | } |
1853 | } | |
be0e5c09 CM |
1854 | } else { |
1855 | p->slots[level] = slot; | |
87b29b20 YZ |
1856 | if (ins_len > 0 && |
1857 | btrfs_leaf_free_space(root, b) < ins_len) { | |
b4ce94de | 1858 | btrfs_set_path_blocking(p); |
33c66f43 YZ |
1859 | err = split_leaf(trans, root, key, |
1860 | p, ins_len, ret == 0); | |
4008c04a | 1861 | btrfs_clear_path_blocking(p, NULL); |
b4ce94de | 1862 | |
33c66f43 YZ |
1863 | BUG_ON(err > 0); |
1864 | if (err) { | |
1865 | ret = err; | |
65b51a00 CM |
1866 | goto done; |
1867 | } | |
5c680ed6 | 1868 | } |
459931ec CM |
1869 | if (!p->search_for_split) |
1870 | unlock_up(p, level, lowest_unlock); | |
65b51a00 | 1871 | goto done; |
be0e5c09 CM |
1872 | } |
1873 | } | |
65b51a00 CM |
1874 | ret = 1; |
1875 | done: | |
b4ce94de CM |
1876 | /* |
1877 | * we don't really know what they plan on doing with the path | |
1878 | * from here on, so for now just mark it as blocking | |
1879 | */ | |
b9473439 CM |
1880 | if (!p->leave_spinning) |
1881 | btrfs_set_path_blocking(p); | |
76a05b35 CM |
1882 | if (ret < 0) |
1883 | btrfs_release_path(root, p); | |
65b51a00 | 1884 | return ret; |
be0e5c09 CM |
1885 | } |
1886 | ||
74123bd7 CM |
1887 | /* |
1888 | * adjust the pointers going up the tree, starting at level | |
1889 | * making sure the right key of each node is points to 'key'. | |
1890 | * This is used after shifting pointers to the left, so it stops | |
1891 | * fixing up pointers when a given leaf/node is not in slot 0 of the | |
1892 | * higher levels | |
aa5d6bed CM |
1893 | * |
1894 | * If this fails to write a tree block, it returns -1, but continues | |
1895 | * fixing up the blocks in ram so the tree is consistent. | |
74123bd7 | 1896 | */ |
5f39d397 CM |
1897 | static int fixup_low_keys(struct btrfs_trans_handle *trans, |
1898 | struct btrfs_root *root, struct btrfs_path *path, | |
1899 | struct btrfs_disk_key *key, int level) | |
be0e5c09 CM |
1900 | { |
1901 | int i; | |
aa5d6bed | 1902 | int ret = 0; |
5f39d397 CM |
1903 | struct extent_buffer *t; |
1904 | ||
234b63a0 | 1905 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { |
be0e5c09 | 1906 | int tslot = path->slots[i]; |
eb60ceac | 1907 | if (!path->nodes[i]) |
be0e5c09 | 1908 | break; |
5f39d397 CM |
1909 | t = path->nodes[i]; |
1910 | btrfs_set_node_key(t, key, tslot); | |
d6025579 | 1911 | btrfs_mark_buffer_dirty(path->nodes[i]); |
be0e5c09 CM |
1912 | if (tslot != 0) |
1913 | break; | |
1914 | } | |
aa5d6bed | 1915 | return ret; |
be0e5c09 CM |
1916 | } |
1917 | ||
31840ae1 ZY |
1918 | /* |
1919 | * update item key. | |
1920 | * | |
1921 | * This function isn't completely safe. It's the caller's responsibility | |
1922 | * that the new key won't break the order | |
1923 | */ | |
1924 | int btrfs_set_item_key_safe(struct btrfs_trans_handle *trans, | |
1925 | struct btrfs_root *root, struct btrfs_path *path, | |
1926 | struct btrfs_key *new_key) | |
1927 | { | |
1928 | struct btrfs_disk_key disk_key; | |
1929 | struct extent_buffer *eb; | |
1930 | int slot; | |
1931 | ||
1932 | eb = path->nodes[0]; | |
1933 | slot = path->slots[0]; | |
1934 | if (slot > 0) { | |
1935 | btrfs_item_key(eb, &disk_key, slot - 1); | |
1936 | if (comp_keys(&disk_key, new_key) >= 0) | |
1937 | return -1; | |
1938 | } | |
1939 | if (slot < btrfs_header_nritems(eb) - 1) { | |
1940 | btrfs_item_key(eb, &disk_key, slot + 1); | |
1941 | if (comp_keys(&disk_key, new_key) <= 0) | |
1942 | return -1; | |
1943 | } | |
1944 | ||
1945 | btrfs_cpu_key_to_disk(&disk_key, new_key); | |
1946 | btrfs_set_item_key(eb, &disk_key, slot); | |
1947 | btrfs_mark_buffer_dirty(eb); | |
1948 | if (slot == 0) | |
1949 | fixup_low_keys(trans, root, path, &disk_key, 1); | |
1950 | return 0; | |
1951 | } | |
1952 | ||
74123bd7 CM |
1953 | /* |
1954 | * try to push data from one node into the next node left in the | |
79f95c82 | 1955 | * tree. |
aa5d6bed CM |
1956 | * |
1957 | * returns 0 if some ptrs were pushed left, < 0 if there was some horrible | |
1958 | * error, and > 0 if there was no room in the left hand block. | |
74123bd7 | 1959 | */ |
98ed5174 CM |
1960 | static int push_node_left(struct btrfs_trans_handle *trans, |
1961 | struct btrfs_root *root, struct extent_buffer *dst, | |
971a1f66 | 1962 | struct extent_buffer *src, int empty) |
be0e5c09 | 1963 | { |
be0e5c09 | 1964 | int push_items = 0; |
bb803951 CM |
1965 | int src_nritems; |
1966 | int dst_nritems; | |
aa5d6bed | 1967 | int ret = 0; |
be0e5c09 | 1968 | |
5f39d397 CM |
1969 | src_nritems = btrfs_header_nritems(src); |
1970 | dst_nritems = btrfs_header_nritems(dst); | |
123abc88 | 1971 | push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems; |
7bb86316 CM |
1972 | WARN_ON(btrfs_header_generation(src) != trans->transid); |
1973 | WARN_ON(btrfs_header_generation(dst) != trans->transid); | |
54aa1f4d | 1974 | |
bce4eae9 | 1975 | if (!empty && src_nritems <= 8) |
971a1f66 CM |
1976 | return 1; |
1977 | ||
d397712b | 1978 | if (push_items <= 0) |
be0e5c09 CM |
1979 | return 1; |
1980 | ||
bce4eae9 | 1981 | if (empty) { |
971a1f66 | 1982 | push_items = min(src_nritems, push_items); |
bce4eae9 CM |
1983 | if (push_items < src_nritems) { |
1984 | /* leave at least 8 pointers in the node if | |
1985 | * we aren't going to empty it | |
1986 | */ | |
1987 | if (src_nritems - push_items < 8) { | |
1988 | if (push_items <= 8) | |
1989 | return 1; | |
1990 | push_items -= 8; | |
1991 | } | |
1992 | } | |
1993 | } else | |
1994 | push_items = min(src_nritems - 8, push_items); | |
79f95c82 | 1995 | |
5f39d397 CM |
1996 | copy_extent_buffer(dst, src, |
1997 | btrfs_node_key_ptr_offset(dst_nritems), | |
1998 | btrfs_node_key_ptr_offset(0), | |
d397712b | 1999 | push_items * sizeof(struct btrfs_key_ptr)); |
5f39d397 | 2000 | |
bb803951 | 2001 | if (push_items < src_nritems) { |
5f39d397 CM |
2002 | memmove_extent_buffer(src, btrfs_node_key_ptr_offset(0), |
2003 | btrfs_node_key_ptr_offset(push_items), | |
2004 | (src_nritems - push_items) * | |
2005 | sizeof(struct btrfs_key_ptr)); | |
2006 | } | |
2007 | btrfs_set_header_nritems(src, src_nritems - push_items); | |
2008 | btrfs_set_header_nritems(dst, dst_nritems + push_items); | |
2009 | btrfs_mark_buffer_dirty(src); | |
2010 | btrfs_mark_buffer_dirty(dst); | |
31840ae1 | 2011 | |
79f95c82 CM |
2012 | return ret; |
2013 | } | |
2014 | ||
2015 | /* | |
2016 | * try to push data from one node into the next node right in the | |
2017 | * tree. | |
2018 | * | |
2019 | * returns 0 if some ptrs were pushed, < 0 if there was some horrible | |
2020 | * error, and > 0 if there was no room in the right hand block. | |
2021 | * | |
2022 | * this will only push up to 1/2 the contents of the left node over | |
2023 | */ | |
5f39d397 CM |
2024 | static int balance_node_right(struct btrfs_trans_handle *trans, |
2025 | struct btrfs_root *root, | |
2026 | struct extent_buffer *dst, | |
2027 | struct extent_buffer *src) | |
79f95c82 | 2028 | { |
79f95c82 CM |
2029 | int push_items = 0; |
2030 | int max_push; | |
2031 | int src_nritems; | |
2032 | int dst_nritems; | |
2033 | int ret = 0; | |
79f95c82 | 2034 | |
7bb86316 CM |
2035 | WARN_ON(btrfs_header_generation(src) != trans->transid); |
2036 | WARN_ON(btrfs_header_generation(dst) != trans->transid); | |
2037 | ||
5f39d397 CM |
2038 | src_nritems = btrfs_header_nritems(src); |
2039 | dst_nritems = btrfs_header_nritems(dst); | |
123abc88 | 2040 | push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems; |
d397712b | 2041 | if (push_items <= 0) |
79f95c82 | 2042 | return 1; |
bce4eae9 | 2043 | |
d397712b | 2044 | if (src_nritems < 4) |
bce4eae9 | 2045 | return 1; |
79f95c82 CM |
2046 | |
2047 | max_push = src_nritems / 2 + 1; | |
2048 | /* don't try to empty the node */ | |
d397712b | 2049 | if (max_push >= src_nritems) |
79f95c82 | 2050 | return 1; |
252c38f0 | 2051 | |
79f95c82 CM |
2052 | if (max_push < push_items) |
2053 | push_items = max_push; | |
2054 | ||
5f39d397 CM |
2055 | memmove_extent_buffer(dst, btrfs_node_key_ptr_offset(push_items), |
2056 | btrfs_node_key_ptr_offset(0), | |
2057 | (dst_nritems) * | |
2058 | sizeof(struct btrfs_key_ptr)); | |
d6025579 | 2059 | |
5f39d397 CM |
2060 | copy_extent_buffer(dst, src, |
2061 | btrfs_node_key_ptr_offset(0), | |
2062 | btrfs_node_key_ptr_offset(src_nritems - push_items), | |
d397712b | 2063 | push_items * sizeof(struct btrfs_key_ptr)); |
79f95c82 | 2064 | |
5f39d397 CM |
2065 | btrfs_set_header_nritems(src, src_nritems - push_items); |
2066 | btrfs_set_header_nritems(dst, dst_nritems + push_items); | |
79f95c82 | 2067 | |
5f39d397 CM |
2068 | btrfs_mark_buffer_dirty(src); |
2069 | btrfs_mark_buffer_dirty(dst); | |
31840ae1 | 2070 | |
aa5d6bed | 2071 | return ret; |
be0e5c09 CM |
2072 | } |
2073 | ||
97571fd0 CM |
2074 | /* |
2075 | * helper function to insert a new root level in the tree. | |
2076 | * A new node is allocated, and a single item is inserted to | |
2077 | * point to the existing root | |
aa5d6bed CM |
2078 | * |
2079 | * returns zero on success or < 0 on failure. | |
97571fd0 | 2080 | */ |
d397712b | 2081 | static noinline int insert_new_root(struct btrfs_trans_handle *trans, |
5f39d397 CM |
2082 | struct btrfs_root *root, |
2083 | struct btrfs_path *path, int level) | |
5c680ed6 | 2084 | { |
7bb86316 | 2085 | u64 lower_gen; |
5f39d397 CM |
2086 | struct extent_buffer *lower; |
2087 | struct extent_buffer *c; | |
925baedd | 2088 | struct extent_buffer *old; |
5f39d397 | 2089 | struct btrfs_disk_key lower_key; |
5c680ed6 CM |
2090 | |
2091 | BUG_ON(path->nodes[level]); | |
2092 | BUG_ON(path->nodes[level-1] != root->node); | |
2093 | ||
7bb86316 CM |
2094 | lower = path->nodes[level-1]; |
2095 | if (level == 1) | |
2096 | btrfs_item_key(lower, &lower_key, 0); | |
2097 | else | |
2098 | btrfs_node_key(lower, &lower_key, 0); | |
2099 | ||
31840ae1 | 2100 | c = btrfs_alloc_free_block(trans, root, root->nodesize, 0, |
5d4f98a2 | 2101 | root->root_key.objectid, &lower_key, |
ad3d81ba | 2102 | level, root->node->start, 0); |
5f39d397 CM |
2103 | if (IS_ERR(c)) |
2104 | return PTR_ERR(c); | |
925baedd | 2105 | |
f0486c68 YZ |
2106 | root_add_used(root, root->nodesize); |
2107 | ||
5d4f98a2 | 2108 | memset_extent_buffer(c, 0, 0, sizeof(struct btrfs_header)); |
5f39d397 CM |
2109 | btrfs_set_header_nritems(c, 1); |
2110 | btrfs_set_header_level(c, level); | |
db94535d | 2111 | btrfs_set_header_bytenr(c, c->start); |
5f39d397 | 2112 | btrfs_set_header_generation(c, trans->transid); |
5d4f98a2 | 2113 | btrfs_set_header_backref_rev(c, BTRFS_MIXED_BACKREF_REV); |
5f39d397 | 2114 | btrfs_set_header_owner(c, root->root_key.objectid); |
5f39d397 CM |
2115 | |
2116 | write_extent_buffer(c, root->fs_info->fsid, | |
2117 | (unsigned long)btrfs_header_fsid(c), | |
2118 | BTRFS_FSID_SIZE); | |
e17cade2 CM |
2119 | |
2120 | write_extent_buffer(c, root->fs_info->chunk_tree_uuid, | |
2121 | (unsigned long)btrfs_header_chunk_tree_uuid(c), | |
2122 | BTRFS_UUID_SIZE); | |
2123 | ||
5f39d397 | 2124 | btrfs_set_node_key(c, &lower_key, 0); |
db94535d | 2125 | btrfs_set_node_blockptr(c, 0, lower->start); |
7bb86316 | 2126 | lower_gen = btrfs_header_generation(lower); |
31840ae1 | 2127 | WARN_ON(lower_gen != trans->transid); |
7bb86316 CM |
2128 | |
2129 | btrfs_set_node_ptr_generation(c, 0, lower_gen); | |
d5719762 | 2130 | |
5f39d397 | 2131 | btrfs_mark_buffer_dirty(c); |
d5719762 | 2132 | |
925baedd CM |
2133 | spin_lock(&root->node_lock); |
2134 | old = root->node; | |
5f39d397 | 2135 | root->node = c; |
925baedd CM |
2136 | spin_unlock(&root->node_lock); |
2137 | ||
2138 | /* the super has an extra ref to root->node */ | |
2139 | free_extent_buffer(old); | |
2140 | ||
0b86a832 | 2141 | add_root_to_dirty_list(root); |
5f39d397 CM |
2142 | extent_buffer_get(c); |
2143 | path->nodes[level] = c; | |
925baedd | 2144 | path->locks[level] = 1; |
5c680ed6 CM |
2145 | path->slots[level] = 0; |
2146 | return 0; | |
2147 | } | |
2148 | ||
74123bd7 CM |
2149 | /* |
2150 | * worker function to insert a single pointer in a node. | |
2151 | * the node should have enough room for the pointer already | |
97571fd0 | 2152 | * |
74123bd7 CM |
2153 | * slot and level indicate where you want the key to go, and |
2154 | * blocknr is the block the key points to. | |
aa5d6bed CM |
2155 | * |
2156 | * returns zero on success and < 0 on any error | |
74123bd7 | 2157 | */ |
e089f05c CM |
2158 | static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root |
2159 | *root, struct btrfs_path *path, struct btrfs_disk_key | |
db94535d | 2160 | *key, u64 bytenr, int slot, int level) |
74123bd7 | 2161 | { |
5f39d397 | 2162 | struct extent_buffer *lower; |
74123bd7 | 2163 | int nritems; |
5c680ed6 CM |
2164 | |
2165 | BUG_ON(!path->nodes[level]); | |
f0486c68 | 2166 | btrfs_assert_tree_locked(path->nodes[level]); |
5f39d397 CM |
2167 | lower = path->nodes[level]; |
2168 | nritems = btrfs_header_nritems(lower); | |
c293498b | 2169 | BUG_ON(slot > nritems); |
123abc88 | 2170 | if (nritems == BTRFS_NODEPTRS_PER_BLOCK(root)) |
74123bd7 CM |
2171 | BUG(); |
2172 | if (slot != nritems) { | |
5f39d397 CM |
2173 | memmove_extent_buffer(lower, |
2174 | btrfs_node_key_ptr_offset(slot + 1), | |
2175 | btrfs_node_key_ptr_offset(slot), | |
d6025579 | 2176 | (nritems - slot) * sizeof(struct btrfs_key_ptr)); |
74123bd7 | 2177 | } |
5f39d397 | 2178 | btrfs_set_node_key(lower, key, slot); |
db94535d | 2179 | btrfs_set_node_blockptr(lower, slot, bytenr); |
74493f7a CM |
2180 | WARN_ON(trans->transid == 0); |
2181 | btrfs_set_node_ptr_generation(lower, slot, trans->transid); | |
5f39d397 CM |
2182 | btrfs_set_header_nritems(lower, nritems + 1); |
2183 | btrfs_mark_buffer_dirty(lower); | |
74123bd7 CM |
2184 | return 0; |
2185 | } | |
2186 | ||
97571fd0 CM |
2187 | /* |
2188 | * split the node at the specified level in path in two. | |
2189 | * The path is corrected to point to the appropriate node after the split | |
2190 | * | |
2191 | * Before splitting this tries to make some room in the node by pushing | |
2192 | * left and right, if either one works, it returns right away. | |
aa5d6bed CM |
2193 | * |
2194 | * returns 0 on success and < 0 on failure | |
97571fd0 | 2195 | */ |
e02119d5 CM |
2196 | static noinline int split_node(struct btrfs_trans_handle *trans, |
2197 | struct btrfs_root *root, | |
2198 | struct btrfs_path *path, int level) | |
be0e5c09 | 2199 | { |
5f39d397 CM |
2200 | struct extent_buffer *c; |
2201 | struct extent_buffer *split; | |
2202 | struct btrfs_disk_key disk_key; | |
be0e5c09 | 2203 | int mid; |
5c680ed6 | 2204 | int ret; |
aa5d6bed | 2205 | int wret; |
7518a238 | 2206 | u32 c_nritems; |
eb60ceac | 2207 | |
5f39d397 | 2208 | c = path->nodes[level]; |
7bb86316 | 2209 | WARN_ON(btrfs_header_generation(c) != trans->transid); |
5f39d397 | 2210 | if (c == root->node) { |
5c680ed6 | 2211 | /* trying to split the root, lets make a new one */ |
e089f05c | 2212 | ret = insert_new_root(trans, root, path, level + 1); |
5c680ed6 CM |
2213 | if (ret) |
2214 | return ret; | |
b3612421 | 2215 | } else { |
e66f709b | 2216 | ret = push_nodes_for_insert(trans, root, path, level); |
5f39d397 CM |
2217 | c = path->nodes[level]; |
2218 | if (!ret && btrfs_header_nritems(c) < | |
c448acf0 | 2219 | BTRFS_NODEPTRS_PER_BLOCK(root) - 3) |
e66f709b | 2220 | return 0; |
54aa1f4d CM |
2221 | if (ret < 0) |
2222 | return ret; | |
be0e5c09 | 2223 | } |
e66f709b | 2224 | |
5f39d397 | 2225 | c_nritems = btrfs_header_nritems(c); |
5d4f98a2 YZ |
2226 | mid = (c_nritems + 1) / 2; |
2227 | btrfs_node_key(c, &disk_key, mid); | |
7bb86316 | 2228 | |
5d4f98a2 | 2229 | split = btrfs_alloc_free_block(trans, root, root->nodesize, 0, |
31840ae1 | 2230 | root->root_key.objectid, |
5d4f98a2 | 2231 | &disk_key, level, c->start, 0); |
5f39d397 CM |
2232 | if (IS_ERR(split)) |
2233 | return PTR_ERR(split); | |
2234 | ||
f0486c68 YZ |
2235 | root_add_used(root, root->nodesize); |
2236 | ||
5d4f98a2 | 2237 | memset_extent_buffer(split, 0, 0, sizeof(struct btrfs_header)); |
5f39d397 | 2238 | btrfs_set_header_level(split, btrfs_header_level(c)); |
db94535d | 2239 | btrfs_set_header_bytenr(split, split->start); |
5f39d397 | 2240 | btrfs_set_header_generation(split, trans->transid); |
5d4f98a2 | 2241 | btrfs_set_header_backref_rev(split, BTRFS_MIXED_BACKREF_REV); |
5f39d397 CM |
2242 | btrfs_set_header_owner(split, root->root_key.objectid); |
2243 | write_extent_buffer(split, root->fs_info->fsid, | |
2244 | (unsigned long)btrfs_header_fsid(split), | |
2245 | BTRFS_FSID_SIZE); | |
e17cade2 CM |
2246 | write_extent_buffer(split, root->fs_info->chunk_tree_uuid, |
2247 | (unsigned long)btrfs_header_chunk_tree_uuid(split), | |
2248 | BTRFS_UUID_SIZE); | |
54aa1f4d | 2249 | |
5f39d397 CM |
2250 | |
2251 | copy_extent_buffer(split, c, | |
2252 | btrfs_node_key_ptr_offset(0), | |
2253 | btrfs_node_key_ptr_offset(mid), | |
2254 | (c_nritems - mid) * sizeof(struct btrfs_key_ptr)); | |
2255 | btrfs_set_header_nritems(split, c_nritems - mid); | |
2256 | btrfs_set_header_nritems(c, mid); | |
aa5d6bed CM |
2257 | ret = 0; |
2258 | ||
5f39d397 CM |
2259 | btrfs_mark_buffer_dirty(c); |
2260 | btrfs_mark_buffer_dirty(split); | |
2261 | ||
db94535d | 2262 | wret = insert_ptr(trans, root, path, &disk_key, split->start, |
5f39d397 | 2263 | path->slots[level + 1] + 1, |
123abc88 | 2264 | level + 1); |
aa5d6bed CM |
2265 | if (wret) |
2266 | ret = wret; | |
2267 | ||
5de08d7d | 2268 | if (path->slots[level] >= mid) { |
5c680ed6 | 2269 | path->slots[level] -= mid; |
925baedd | 2270 | btrfs_tree_unlock(c); |
5f39d397 CM |
2271 | free_extent_buffer(c); |
2272 | path->nodes[level] = split; | |
5c680ed6 CM |
2273 | path->slots[level + 1] += 1; |
2274 | } else { | |
925baedd | 2275 | btrfs_tree_unlock(split); |
5f39d397 | 2276 | free_extent_buffer(split); |
be0e5c09 | 2277 | } |
aa5d6bed | 2278 | return ret; |
be0e5c09 CM |
2279 | } |
2280 | ||
74123bd7 CM |
2281 | /* |
2282 | * how many bytes are required to store the items in a leaf. start | |
2283 | * and nr indicate which items in the leaf to check. This totals up the | |
2284 | * space used both by the item structs and the item data | |
2285 | */ | |
5f39d397 | 2286 | static int leaf_space_used(struct extent_buffer *l, int start, int nr) |
be0e5c09 CM |
2287 | { |
2288 | int data_len; | |
5f39d397 | 2289 | int nritems = btrfs_header_nritems(l); |
d4dbff95 | 2290 | int end = min(nritems, start + nr) - 1; |
be0e5c09 CM |
2291 | |
2292 | if (!nr) | |
2293 | return 0; | |
5f39d397 CM |
2294 | data_len = btrfs_item_end_nr(l, start); |
2295 | data_len = data_len - btrfs_item_offset_nr(l, end); | |
0783fcfc | 2296 | data_len += sizeof(struct btrfs_item) * nr; |
d4dbff95 | 2297 | WARN_ON(data_len < 0); |
be0e5c09 CM |
2298 | return data_len; |
2299 | } | |
2300 | ||
d4dbff95 CM |
2301 | /* |
2302 | * The space between the end of the leaf items and | |
2303 | * the start of the leaf data. IOW, how much room | |
2304 | * the leaf has left for both items and data | |
2305 | */ | |
d397712b | 2306 | noinline int btrfs_leaf_free_space(struct btrfs_root *root, |
e02119d5 | 2307 | struct extent_buffer *leaf) |
d4dbff95 | 2308 | { |
5f39d397 CM |
2309 | int nritems = btrfs_header_nritems(leaf); |
2310 | int ret; | |
2311 | ret = BTRFS_LEAF_DATA_SIZE(root) - leaf_space_used(leaf, 0, nritems); | |
2312 | if (ret < 0) { | |
d397712b CM |
2313 | printk(KERN_CRIT "leaf free space ret %d, leaf data size %lu, " |
2314 | "used %d nritems %d\n", | |
ae2f5411 | 2315 | ret, (unsigned long) BTRFS_LEAF_DATA_SIZE(root), |
5f39d397 CM |
2316 | leaf_space_used(leaf, 0, nritems), nritems); |
2317 | } | |
2318 | return ret; | |
d4dbff95 CM |
2319 | } |
2320 | ||
99d8f83c CM |
2321 | /* |
2322 | * min slot controls the lowest index we're willing to push to the | |
2323 | * right. We'll push up to and including min_slot, but no lower | |
2324 | */ | |
44871b1b CM |
2325 | static noinline int __push_leaf_right(struct btrfs_trans_handle *trans, |
2326 | struct btrfs_root *root, | |
2327 | struct btrfs_path *path, | |
2328 | int data_size, int empty, | |
2329 | struct extent_buffer *right, | |
99d8f83c CM |
2330 | int free_space, u32 left_nritems, |
2331 | u32 min_slot) | |
00ec4c51 | 2332 | { |
5f39d397 | 2333 | struct extent_buffer *left = path->nodes[0]; |
44871b1b | 2334 | struct extent_buffer *upper = path->nodes[1]; |
5f39d397 | 2335 | struct btrfs_disk_key disk_key; |
00ec4c51 | 2336 | int slot; |
34a38218 | 2337 | u32 i; |
00ec4c51 CM |
2338 | int push_space = 0; |
2339 | int push_items = 0; | |
0783fcfc | 2340 | struct btrfs_item *item; |
34a38218 | 2341 | u32 nr; |
7518a238 | 2342 | u32 right_nritems; |
5f39d397 | 2343 | u32 data_end; |
db94535d | 2344 | u32 this_item_size; |
00ec4c51 | 2345 | |
34a38218 CM |
2346 | if (empty) |
2347 | nr = 0; | |
2348 | else | |
99d8f83c | 2349 | nr = max_t(u32, 1, min_slot); |
34a38218 | 2350 | |
31840ae1 | 2351 | if (path->slots[0] >= left_nritems) |
87b29b20 | 2352 | push_space += data_size; |
31840ae1 | 2353 | |
44871b1b | 2354 | slot = path->slots[1]; |
34a38218 CM |
2355 | i = left_nritems - 1; |
2356 | while (i >= nr) { | |
5f39d397 | 2357 | item = btrfs_item_nr(left, i); |
db94535d | 2358 | |
31840ae1 ZY |
2359 | if (!empty && push_items > 0) { |
2360 | if (path->slots[0] > i) | |
2361 | break; | |
2362 | if (path->slots[0] == i) { | |
2363 | int space = btrfs_leaf_free_space(root, left); | |
2364 | if (space + push_space * 2 > free_space) | |
2365 | break; | |
2366 | } | |
2367 | } | |
2368 | ||
00ec4c51 | 2369 | if (path->slots[0] == i) |
87b29b20 | 2370 | push_space += data_size; |
db94535d CM |
2371 | |
2372 | if (!left->map_token) { | |
2373 | map_extent_buffer(left, (unsigned long)item, | |
2374 | sizeof(struct btrfs_item), | |
2375 | &left->map_token, &left->kaddr, | |
2376 | &left->map_start, &left->map_len, | |
2377 | KM_USER1); | |
2378 | } | |
2379 | ||
2380 | this_item_size = btrfs_item_size(left, item); | |
2381 | if (this_item_size + sizeof(*item) + push_space > free_space) | |
00ec4c51 | 2382 | break; |
31840ae1 | 2383 | |
00ec4c51 | 2384 | push_items++; |
db94535d | 2385 | push_space += this_item_size + sizeof(*item); |
34a38218 CM |
2386 | if (i == 0) |
2387 | break; | |
2388 | i--; | |
db94535d CM |
2389 | } |
2390 | if (left->map_token) { | |
2391 | unmap_extent_buffer(left, left->map_token, KM_USER1); | |
2392 | left->map_token = NULL; | |
00ec4c51 | 2393 | } |
5f39d397 | 2394 | |
925baedd CM |
2395 | if (push_items == 0) |
2396 | goto out_unlock; | |
5f39d397 | 2397 | |
34a38218 | 2398 | if (!empty && push_items == left_nritems) |
a429e513 | 2399 | WARN_ON(1); |
5f39d397 | 2400 | |
00ec4c51 | 2401 | /* push left to right */ |
5f39d397 | 2402 | right_nritems = btrfs_header_nritems(right); |
34a38218 | 2403 | |
5f39d397 | 2404 | push_space = btrfs_item_end_nr(left, left_nritems - push_items); |
123abc88 | 2405 | push_space -= leaf_data_end(root, left); |
5f39d397 | 2406 | |
00ec4c51 | 2407 | /* make room in the right data area */ |
5f39d397 CM |
2408 | data_end = leaf_data_end(root, right); |
2409 | memmove_extent_buffer(right, | |
2410 | btrfs_leaf_data(right) + data_end - push_space, | |
2411 | btrfs_leaf_data(right) + data_end, | |
2412 | BTRFS_LEAF_DATA_SIZE(root) - data_end); | |
2413 | ||
00ec4c51 | 2414 | /* copy from the left data area */ |
5f39d397 | 2415 | copy_extent_buffer(right, left, btrfs_leaf_data(right) + |
d6025579 CM |
2416 | BTRFS_LEAF_DATA_SIZE(root) - push_space, |
2417 | btrfs_leaf_data(left) + leaf_data_end(root, left), | |
2418 | push_space); | |
5f39d397 CM |
2419 | |
2420 | memmove_extent_buffer(right, btrfs_item_nr_offset(push_items), | |
2421 | btrfs_item_nr_offset(0), | |
2422 | right_nritems * sizeof(struct btrfs_item)); | |
2423 | ||
00ec4c51 | 2424 | /* copy the items from left to right */ |
5f39d397 CM |
2425 | copy_extent_buffer(right, left, btrfs_item_nr_offset(0), |
2426 | btrfs_item_nr_offset(left_nritems - push_items), | |
2427 | push_items * sizeof(struct btrfs_item)); | |
00ec4c51 CM |
2428 | |
2429 | /* update the item pointers */ | |
7518a238 | 2430 | right_nritems += push_items; |
5f39d397 | 2431 | btrfs_set_header_nritems(right, right_nritems); |
123abc88 | 2432 | push_space = BTRFS_LEAF_DATA_SIZE(root); |
7518a238 | 2433 | for (i = 0; i < right_nritems; i++) { |
5f39d397 | 2434 | item = btrfs_item_nr(right, i); |
db94535d CM |
2435 | if (!right->map_token) { |
2436 | map_extent_buffer(right, (unsigned long)item, | |
2437 | sizeof(struct btrfs_item), | |
2438 | &right->map_token, &right->kaddr, | |
2439 | &right->map_start, &right->map_len, | |
2440 | KM_USER1); | |
2441 | } | |
2442 | push_space -= btrfs_item_size(right, item); | |
2443 | btrfs_set_item_offset(right, item, push_space); | |
2444 | } | |
2445 | ||
2446 | if (right->map_token) { | |
2447 | unmap_extent_buffer(right, right->map_token, KM_USER1); | |
2448 | right->map_token = NULL; | |
00ec4c51 | 2449 | } |
7518a238 | 2450 | left_nritems -= push_items; |
5f39d397 | 2451 | btrfs_set_header_nritems(left, left_nritems); |
00ec4c51 | 2452 | |
34a38218 CM |
2453 | if (left_nritems) |
2454 | btrfs_mark_buffer_dirty(left); | |
f0486c68 YZ |
2455 | else |
2456 | clean_tree_block(trans, root, left); | |
2457 | ||
5f39d397 | 2458 | btrfs_mark_buffer_dirty(right); |
a429e513 | 2459 | |
5f39d397 CM |
2460 | btrfs_item_key(right, &disk_key, 0); |
2461 | btrfs_set_node_key(upper, &disk_key, slot + 1); | |
d6025579 | 2462 | btrfs_mark_buffer_dirty(upper); |
02217ed2 | 2463 | |
00ec4c51 | 2464 | /* then fixup the leaf pointer in the path */ |
7518a238 CM |
2465 | if (path->slots[0] >= left_nritems) { |
2466 | path->slots[0] -= left_nritems; | |
925baedd CM |
2467 | if (btrfs_header_nritems(path->nodes[0]) == 0) |
2468 | clean_tree_block(trans, root, path->nodes[0]); | |
2469 | btrfs_tree_unlock(path->nodes[0]); | |
5f39d397 CM |
2470 | free_extent_buffer(path->nodes[0]); |
2471 | path->nodes[0] = right; | |
00ec4c51 CM |
2472 | path->slots[1] += 1; |
2473 | } else { | |
925baedd | 2474 | btrfs_tree_unlock(right); |
5f39d397 | 2475 | free_extent_buffer(right); |
00ec4c51 CM |
2476 | } |
2477 | return 0; | |
925baedd CM |
2478 | |
2479 | out_unlock: | |
2480 | btrfs_tree_unlock(right); | |
2481 | free_extent_buffer(right); | |
2482 | return 1; | |
00ec4c51 | 2483 | } |
925baedd | 2484 | |
44871b1b CM |
2485 | /* |
2486 | * push some data in the path leaf to the right, trying to free up at | |
2487 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
2488 | * | |
2489 | * returns 1 if the push failed because the other node didn't have enough | |
2490 | * room, 0 if everything worked out and < 0 if there were major errors. | |
99d8f83c CM |
2491 | * |
2492 | * this will push starting from min_slot to the end of the leaf. It won't | |
2493 | * push any slot lower than min_slot | |
44871b1b CM |
2494 | */ |
2495 | static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root | |
99d8f83c CM |
2496 | *root, struct btrfs_path *path, |
2497 | int min_data_size, int data_size, | |
2498 | int empty, u32 min_slot) | |
44871b1b CM |
2499 | { |
2500 | struct extent_buffer *left = path->nodes[0]; | |
2501 | struct extent_buffer *right; | |
2502 | struct extent_buffer *upper; | |
2503 | int slot; | |
2504 | int free_space; | |
2505 | u32 left_nritems; | |
2506 | int ret; | |
2507 | ||
2508 | if (!path->nodes[1]) | |
2509 | return 1; | |
2510 | ||
2511 | slot = path->slots[1]; | |
2512 | upper = path->nodes[1]; | |
2513 | if (slot >= btrfs_header_nritems(upper) - 1) | |
2514 | return 1; | |
2515 | ||
2516 | btrfs_assert_tree_locked(path->nodes[1]); | |
2517 | ||
2518 | right = read_node_slot(root, upper, slot + 1); | |
91ca338d TI |
2519 | if (right == NULL) |
2520 | return 1; | |
2521 | ||
44871b1b CM |
2522 | btrfs_tree_lock(right); |
2523 | btrfs_set_lock_blocking(right); | |
2524 | ||
2525 | free_space = btrfs_leaf_free_space(root, right); | |
2526 | if (free_space < data_size) | |
2527 | goto out_unlock; | |
2528 | ||
2529 | /* cow and double check */ | |
2530 | ret = btrfs_cow_block(trans, root, right, upper, | |
2531 | slot + 1, &right); | |
2532 | if (ret) | |
2533 | goto out_unlock; | |
2534 | ||
2535 | free_space = btrfs_leaf_free_space(root, right); | |
2536 | if (free_space < data_size) | |
2537 | goto out_unlock; | |
2538 | ||
2539 | left_nritems = btrfs_header_nritems(left); | |
2540 | if (left_nritems == 0) | |
2541 | goto out_unlock; | |
2542 | ||
99d8f83c CM |
2543 | return __push_leaf_right(trans, root, path, min_data_size, empty, |
2544 | right, free_space, left_nritems, min_slot); | |
44871b1b CM |
2545 | out_unlock: |
2546 | btrfs_tree_unlock(right); | |
2547 | free_extent_buffer(right); | |
2548 | return 1; | |
2549 | } | |
2550 | ||
74123bd7 CM |
2551 | /* |
2552 | * push some data in the path leaf to the left, trying to free up at | |
2553 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
99d8f83c CM |
2554 | * |
2555 | * max_slot can put a limit on how far into the leaf we'll push items. The | |
2556 | * item at 'max_slot' won't be touched. Use (u32)-1 to make us do all the | |
2557 | * items | |
74123bd7 | 2558 | */ |
44871b1b CM |
2559 | static noinline int __push_leaf_left(struct btrfs_trans_handle *trans, |
2560 | struct btrfs_root *root, | |
2561 | struct btrfs_path *path, int data_size, | |
2562 | int empty, struct extent_buffer *left, | |
99d8f83c CM |
2563 | int free_space, u32 right_nritems, |
2564 | u32 max_slot) | |
be0e5c09 | 2565 | { |
5f39d397 CM |
2566 | struct btrfs_disk_key disk_key; |
2567 | struct extent_buffer *right = path->nodes[0]; | |
be0e5c09 | 2568 | int i; |
be0e5c09 CM |
2569 | int push_space = 0; |
2570 | int push_items = 0; | |
0783fcfc | 2571 | struct btrfs_item *item; |
7518a238 | 2572 | u32 old_left_nritems; |
34a38218 | 2573 | u32 nr; |
aa5d6bed CM |
2574 | int ret = 0; |
2575 | int wret; | |
db94535d CM |
2576 | u32 this_item_size; |
2577 | u32 old_left_item_size; | |
be0e5c09 | 2578 | |
34a38218 | 2579 | if (empty) |
99d8f83c | 2580 | nr = min(right_nritems, max_slot); |
34a38218 | 2581 | else |
99d8f83c | 2582 | nr = min(right_nritems - 1, max_slot); |
34a38218 CM |
2583 | |
2584 | for (i = 0; i < nr; i++) { | |
5f39d397 | 2585 | item = btrfs_item_nr(right, i); |
db94535d CM |
2586 | if (!right->map_token) { |
2587 | map_extent_buffer(right, (unsigned long)item, | |
2588 | sizeof(struct btrfs_item), | |
2589 | &right->map_token, &right->kaddr, | |
2590 | &right->map_start, &right->map_len, | |
2591 | KM_USER1); | |
2592 | } | |
2593 | ||
31840ae1 ZY |
2594 | if (!empty && push_items > 0) { |
2595 | if (path->slots[0] < i) | |
2596 | break; | |
2597 | if (path->slots[0] == i) { | |
2598 | int space = btrfs_leaf_free_space(root, right); | |
2599 | if (space + push_space * 2 > free_space) | |
2600 | break; | |
2601 | } | |
2602 | } | |
2603 | ||
be0e5c09 | 2604 | if (path->slots[0] == i) |
87b29b20 | 2605 | push_space += data_size; |
db94535d CM |
2606 | |
2607 | this_item_size = btrfs_item_size(right, item); | |
2608 | if (this_item_size + sizeof(*item) + push_space > free_space) | |
be0e5c09 | 2609 | break; |
db94535d | 2610 | |
be0e5c09 | 2611 | push_items++; |
db94535d CM |
2612 | push_space += this_item_size + sizeof(*item); |
2613 | } | |
2614 | ||
2615 | if (right->map_token) { | |
2616 | unmap_extent_buffer(right, right->map_token, KM_USER1); | |
2617 | right->map_token = NULL; | |
be0e5c09 | 2618 | } |
db94535d | 2619 | |
be0e5c09 | 2620 | if (push_items == 0) { |
925baedd CM |
2621 | ret = 1; |
2622 | goto out; | |
be0e5c09 | 2623 | } |
34a38218 | 2624 | if (!empty && push_items == btrfs_header_nritems(right)) |
a429e513 | 2625 | WARN_ON(1); |
5f39d397 | 2626 | |
be0e5c09 | 2627 | /* push data from right to left */ |
5f39d397 CM |
2628 | copy_extent_buffer(left, right, |
2629 | btrfs_item_nr_offset(btrfs_header_nritems(left)), | |
2630 | btrfs_item_nr_offset(0), | |
2631 | push_items * sizeof(struct btrfs_item)); | |
2632 | ||
123abc88 | 2633 | push_space = BTRFS_LEAF_DATA_SIZE(root) - |
d397712b | 2634 | btrfs_item_offset_nr(right, push_items - 1); |
5f39d397 CM |
2635 | |
2636 | copy_extent_buffer(left, right, btrfs_leaf_data(left) + | |
d6025579 CM |
2637 | leaf_data_end(root, left) - push_space, |
2638 | btrfs_leaf_data(right) + | |
5f39d397 | 2639 | btrfs_item_offset_nr(right, push_items - 1), |
d6025579 | 2640 | push_space); |
5f39d397 | 2641 | old_left_nritems = btrfs_header_nritems(left); |
87b29b20 | 2642 | BUG_ON(old_left_nritems <= 0); |
eb60ceac | 2643 | |
db94535d | 2644 | old_left_item_size = btrfs_item_offset_nr(left, old_left_nritems - 1); |
0783fcfc | 2645 | for (i = old_left_nritems; i < old_left_nritems + push_items; i++) { |
5f39d397 | 2646 | u32 ioff; |
db94535d | 2647 | |
5f39d397 | 2648 | item = btrfs_item_nr(left, i); |
db94535d CM |
2649 | if (!left->map_token) { |
2650 | map_extent_buffer(left, (unsigned long)item, | |
2651 | sizeof(struct btrfs_item), | |
2652 | &left->map_token, &left->kaddr, | |
2653 | &left->map_start, &left->map_len, | |
2654 | KM_USER1); | |
2655 | } | |
2656 | ||
5f39d397 CM |
2657 | ioff = btrfs_item_offset(left, item); |
2658 | btrfs_set_item_offset(left, item, | |
db94535d | 2659 | ioff - (BTRFS_LEAF_DATA_SIZE(root) - old_left_item_size)); |
be0e5c09 | 2660 | } |
5f39d397 | 2661 | btrfs_set_header_nritems(left, old_left_nritems + push_items); |
db94535d CM |
2662 | if (left->map_token) { |
2663 | unmap_extent_buffer(left, left->map_token, KM_USER1); | |
2664 | left->map_token = NULL; | |
2665 | } | |
be0e5c09 CM |
2666 | |
2667 | /* fixup right node */ | |
34a38218 | 2668 | if (push_items > right_nritems) { |
d397712b CM |
2669 | printk(KERN_CRIT "push items %d nr %u\n", push_items, |
2670 | right_nritems); | |
34a38218 CM |
2671 | WARN_ON(1); |
2672 | } | |
2673 | ||
2674 | if (push_items < right_nritems) { | |
2675 | push_space = btrfs_item_offset_nr(right, push_items - 1) - | |
2676 | leaf_data_end(root, right); | |
2677 | memmove_extent_buffer(right, btrfs_leaf_data(right) + | |
2678 | BTRFS_LEAF_DATA_SIZE(root) - push_space, | |
2679 | btrfs_leaf_data(right) + | |
2680 | leaf_data_end(root, right), push_space); | |
2681 | ||
2682 | memmove_extent_buffer(right, btrfs_item_nr_offset(0), | |
5f39d397 CM |
2683 | btrfs_item_nr_offset(push_items), |
2684 | (btrfs_header_nritems(right) - push_items) * | |
2685 | sizeof(struct btrfs_item)); | |
34a38218 | 2686 | } |
eef1c494 Y |
2687 | right_nritems -= push_items; |
2688 | btrfs_set_header_nritems(right, right_nritems); | |
123abc88 | 2689 | push_space = BTRFS_LEAF_DATA_SIZE(root); |
5f39d397 CM |
2690 | for (i = 0; i < right_nritems; i++) { |
2691 | item = btrfs_item_nr(right, i); | |
db94535d CM |
2692 | |
2693 | if (!right->map_token) { | |
2694 | map_extent_buffer(right, (unsigned long)item, | |
2695 | sizeof(struct btrfs_item), | |
2696 | &right->map_token, &right->kaddr, | |
2697 | &right->map_start, &right->map_len, | |
2698 | KM_USER1); | |
2699 | } | |
2700 | ||
2701 | push_space = push_space - btrfs_item_size(right, item); | |
2702 | btrfs_set_item_offset(right, item, push_space); | |
2703 | } | |
2704 | if (right->map_token) { | |
2705 | unmap_extent_buffer(right, right->map_token, KM_USER1); | |
2706 | right->map_token = NULL; | |
be0e5c09 | 2707 | } |
eb60ceac | 2708 | |
5f39d397 | 2709 | btrfs_mark_buffer_dirty(left); |
34a38218 CM |
2710 | if (right_nritems) |
2711 | btrfs_mark_buffer_dirty(right); | |
f0486c68 YZ |
2712 | else |
2713 | clean_tree_block(trans, root, right); | |
098f59c2 | 2714 | |
5f39d397 CM |
2715 | btrfs_item_key(right, &disk_key, 0); |
2716 | wret = fixup_low_keys(trans, root, path, &disk_key, 1); | |
aa5d6bed CM |
2717 | if (wret) |
2718 | ret = wret; | |
be0e5c09 CM |
2719 | |
2720 | /* then fixup the leaf pointer in the path */ | |
2721 | if (path->slots[0] < push_items) { | |
2722 | path->slots[0] += old_left_nritems; | |
925baedd | 2723 | btrfs_tree_unlock(path->nodes[0]); |
5f39d397 CM |
2724 | free_extent_buffer(path->nodes[0]); |
2725 | path->nodes[0] = left; | |
be0e5c09 CM |
2726 | path->slots[1] -= 1; |
2727 | } else { | |
925baedd | 2728 | btrfs_tree_unlock(left); |
5f39d397 | 2729 | free_extent_buffer(left); |
be0e5c09 CM |
2730 | path->slots[0] -= push_items; |
2731 | } | |
eb60ceac | 2732 | BUG_ON(path->slots[0] < 0); |
aa5d6bed | 2733 | return ret; |
925baedd CM |
2734 | out: |
2735 | btrfs_tree_unlock(left); | |
2736 | free_extent_buffer(left); | |
2737 | return ret; | |
be0e5c09 CM |
2738 | } |
2739 | ||
44871b1b CM |
2740 | /* |
2741 | * push some data in the path leaf to the left, trying to free up at | |
2742 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
99d8f83c CM |
2743 | * |
2744 | * max_slot can put a limit on how far into the leaf we'll push items. The | |
2745 | * item at 'max_slot' won't be touched. Use (u32)-1 to make us push all the | |
2746 | * items | |
44871b1b CM |
2747 | */ |
2748 | static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root | |
99d8f83c CM |
2749 | *root, struct btrfs_path *path, int min_data_size, |
2750 | int data_size, int empty, u32 max_slot) | |
44871b1b CM |
2751 | { |
2752 | struct extent_buffer *right = path->nodes[0]; | |
2753 | struct extent_buffer *left; | |
2754 | int slot; | |
2755 | int free_space; | |
2756 | u32 right_nritems; | |
2757 | int ret = 0; | |
2758 | ||
2759 | slot = path->slots[1]; | |
2760 | if (slot == 0) | |
2761 | return 1; | |
2762 | if (!path->nodes[1]) | |
2763 | return 1; | |
2764 | ||
2765 | right_nritems = btrfs_header_nritems(right); | |
2766 | if (right_nritems == 0) | |
2767 | return 1; | |
2768 | ||
2769 | btrfs_assert_tree_locked(path->nodes[1]); | |
2770 | ||
2771 | left = read_node_slot(root, path->nodes[1], slot - 1); | |
91ca338d TI |
2772 | if (left == NULL) |
2773 | return 1; | |
2774 | ||
44871b1b CM |
2775 | btrfs_tree_lock(left); |
2776 | btrfs_set_lock_blocking(left); | |
2777 | ||
2778 | free_space = btrfs_leaf_free_space(root, left); | |
2779 | if (free_space < data_size) { | |
2780 | ret = 1; | |
2781 | goto out; | |
2782 | } | |
2783 | ||
2784 | /* cow and double check */ | |
2785 | ret = btrfs_cow_block(trans, root, left, | |
2786 | path->nodes[1], slot - 1, &left); | |
2787 | if (ret) { | |
2788 | /* we hit -ENOSPC, but it isn't fatal here */ | |
2789 | ret = 1; | |
2790 | goto out; | |
2791 | } | |
2792 | ||
2793 | free_space = btrfs_leaf_free_space(root, left); | |
2794 | if (free_space < data_size) { | |
2795 | ret = 1; | |
2796 | goto out; | |
2797 | } | |
2798 | ||
99d8f83c CM |
2799 | return __push_leaf_left(trans, root, path, min_data_size, |
2800 | empty, left, free_space, right_nritems, | |
2801 | max_slot); | |
44871b1b CM |
2802 | out: |
2803 | btrfs_tree_unlock(left); | |
2804 | free_extent_buffer(left); | |
2805 | return ret; | |
2806 | } | |
2807 | ||
2808 | /* | |
2809 | * split the path's leaf in two, making sure there is at least data_size | |
2810 | * available for the resulting leaf level of the path. | |
2811 | * | |
2812 | * returns 0 if all went well and < 0 on failure. | |
2813 | */ | |
2814 | static noinline int copy_for_split(struct btrfs_trans_handle *trans, | |
2815 | struct btrfs_root *root, | |
2816 | struct btrfs_path *path, | |
2817 | struct extent_buffer *l, | |
2818 | struct extent_buffer *right, | |
2819 | int slot, int mid, int nritems) | |
2820 | { | |
2821 | int data_copy_size; | |
2822 | int rt_data_off; | |
2823 | int i; | |
2824 | int ret = 0; | |
2825 | int wret; | |
2826 | struct btrfs_disk_key disk_key; | |
2827 | ||
2828 | nritems = nritems - mid; | |
2829 | btrfs_set_header_nritems(right, nritems); | |
2830 | data_copy_size = btrfs_item_end_nr(l, mid) - leaf_data_end(root, l); | |
2831 | ||
2832 | copy_extent_buffer(right, l, btrfs_item_nr_offset(0), | |
2833 | btrfs_item_nr_offset(mid), | |
2834 | nritems * sizeof(struct btrfs_item)); | |
2835 | ||
2836 | copy_extent_buffer(right, l, | |
2837 | btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) - | |
2838 | data_copy_size, btrfs_leaf_data(l) + | |
2839 | leaf_data_end(root, l), data_copy_size); | |
2840 | ||
2841 | rt_data_off = BTRFS_LEAF_DATA_SIZE(root) - | |
2842 | btrfs_item_end_nr(l, mid); | |
2843 | ||
2844 | for (i = 0; i < nritems; i++) { | |
2845 | struct btrfs_item *item = btrfs_item_nr(right, i); | |
2846 | u32 ioff; | |
2847 | ||
2848 | if (!right->map_token) { | |
2849 | map_extent_buffer(right, (unsigned long)item, | |
2850 | sizeof(struct btrfs_item), | |
2851 | &right->map_token, &right->kaddr, | |
2852 | &right->map_start, &right->map_len, | |
2853 | KM_USER1); | |
2854 | } | |
2855 | ||
2856 | ioff = btrfs_item_offset(right, item); | |
2857 | btrfs_set_item_offset(right, item, ioff + rt_data_off); | |
2858 | } | |
2859 | ||
2860 | if (right->map_token) { | |
2861 | unmap_extent_buffer(right, right->map_token, KM_USER1); | |
2862 | right->map_token = NULL; | |
2863 | } | |
2864 | ||
2865 | btrfs_set_header_nritems(l, mid); | |
2866 | ret = 0; | |
2867 | btrfs_item_key(right, &disk_key, 0); | |
2868 | wret = insert_ptr(trans, root, path, &disk_key, right->start, | |
2869 | path->slots[1] + 1, 1); | |
2870 | if (wret) | |
2871 | ret = wret; | |
2872 | ||
2873 | btrfs_mark_buffer_dirty(right); | |
2874 | btrfs_mark_buffer_dirty(l); | |
2875 | BUG_ON(path->slots[0] != slot); | |
2876 | ||
44871b1b CM |
2877 | if (mid <= slot) { |
2878 | btrfs_tree_unlock(path->nodes[0]); | |
2879 | free_extent_buffer(path->nodes[0]); | |
2880 | path->nodes[0] = right; | |
2881 | path->slots[0] -= mid; | |
2882 | path->slots[1] += 1; | |
2883 | } else { | |
2884 | btrfs_tree_unlock(right); | |
2885 | free_extent_buffer(right); | |
2886 | } | |
2887 | ||
2888 | BUG_ON(path->slots[0] < 0); | |
2889 | ||
2890 | return ret; | |
2891 | } | |
2892 | ||
99d8f83c CM |
2893 | /* |
2894 | * double splits happen when we need to insert a big item in the middle | |
2895 | * of a leaf. A double split can leave us with 3 mostly empty leaves: | |
2896 | * leaf: [ slots 0 - N] [ our target ] [ N + 1 - total in leaf ] | |
2897 | * A B C | |
2898 | * | |
2899 | * We avoid this by trying to push the items on either side of our target | |
2900 | * into the adjacent leaves. If all goes well we can avoid the double split | |
2901 | * completely. | |
2902 | */ | |
2903 | static noinline int push_for_double_split(struct btrfs_trans_handle *trans, | |
2904 | struct btrfs_root *root, | |
2905 | struct btrfs_path *path, | |
2906 | int data_size) | |
2907 | { | |
2908 | int ret; | |
2909 | int progress = 0; | |
2910 | int slot; | |
2911 | u32 nritems; | |
2912 | ||
2913 | slot = path->slots[0]; | |
2914 | ||
2915 | /* | |
2916 | * try to push all the items after our slot into the | |
2917 | * right leaf | |
2918 | */ | |
2919 | ret = push_leaf_right(trans, root, path, 1, data_size, 0, slot); | |
2920 | if (ret < 0) | |
2921 | return ret; | |
2922 | ||
2923 | if (ret == 0) | |
2924 | progress++; | |
2925 | ||
2926 | nritems = btrfs_header_nritems(path->nodes[0]); | |
2927 | /* | |
2928 | * our goal is to get our slot at the start or end of a leaf. If | |
2929 | * we've done so we're done | |
2930 | */ | |
2931 | if (path->slots[0] == 0 || path->slots[0] == nritems) | |
2932 | return 0; | |
2933 | ||
2934 | if (btrfs_leaf_free_space(root, path->nodes[0]) >= data_size) | |
2935 | return 0; | |
2936 | ||
2937 | /* try to push all the items before our slot into the next leaf */ | |
2938 | slot = path->slots[0]; | |
2939 | ret = push_leaf_left(trans, root, path, 1, data_size, 0, slot); | |
2940 | if (ret < 0) | |
2941 | return ret; | |
2942 | ||
2943 | if (ret == 0) | |
2944 | progress++; | |
2945 | ||
2946 | if (progress) | |
2947 | return 0; | |
2948 | return 1; | |
2949 | } | |
2950 | ||
74123bd7 CM |
2951 | /* |
2952 | * split the path's leaf in two, making sure there is at least data_size | |
2953 | * available for the resulting leaf level of the path. | |
aa5d6bed CM |
2954 | * |
2955 | * returns 0 if all went well and < 0 on failure. | |
74123bd7 | 2956 | */ |
e02119d5 CM |
2957 | static noinline int split_leaf(struct btrfs_trans_handle *trans, |
2958 | struct btrfs_root *root, | |
2959 | struct btrfs_key *ins_key, | |
2960 | struct btrfs_path *path, int data_size, | |
2961 | int extend) | |
be0e5c09 | 2962 | { |
5d4f98a2 | 2963 | struct btrfs_disk_key disk_key; |
5f39d397 | 2964 | struct extent_buffer *l; |
7518a238 | 2965 | u32 nritems; |
eb60ceac CM |
2966 | int mid; |
2967 | int slot; | |
5f39d397 | 2968 | struct extent_buffer *right; |
d4dbff95 | 2969 | int ret = 0; |
aa5d6bed | 2970 | int wret; |
5d4f98a2 | 2971 | int split; |
cc0c5538 | 2972 | int num_doubles = 0; |
99d8f83c | 2973 | int tried_avoid_double = 0; |
aa5d6bed | 2974 | |
a5719521 YZ |
2975 | l = path->nodes[0]; |
2976 | slot = path->slots[0]; | |
2977 | if (extend && data_size + btrfs_item_size_nr(l, slot) + | |
2978 | sizeof(struct btrfs_item) > BTRFS_LEAF_DATA_SIZE(root)) | |
2979 | return -EOVERFLOW; | |
2980 | ||
40689478 | 2981 | /* first try to make some room by pushing left and right */ |
99d8f83c CM |
2982 | if (data_size) { |
2983 | wret = push_leaf_right(trans, root, path, data_size, | |
2984 | data_size, 0, 0); | |
d397712b | 2985 | if (wret < 0) |
eaee50e8 | 2986 | return wret; |
3685f791 | 2987 | if (wret) { |
99d8f83c CM |
2988 | wret = push_leaf_left(trans, root, path, data_size, |
2989 | data_size, 0, (u32)-1); | |
3685f791 CM |
2990 | if (wret < 0) |
2991 | return wret; | |
2992 | } | |
2993 | l = path->nodes[0]; | |
aa5d6bed | 2994 | |
3685f791 | 2995 | /* did the pushes work? */ |
87b29b20 | 2996 | if (btrfs_leaf_free_space(root, l) >= data_size) |
3685f791 | 2997 | return 0; |
3326d1b0 | 2998 | } |
aa5d6bed | 2999 | |
5c680ed6 | 3000 | if (!path->nodes[1]) { |
e089f05c | 3001 | ret = insert_new_root(trans, root, path, 1); |
5c680ed6 CM |
3002 | if (ret) |
3003 | return ret; | |
3004 | } | |
cc0c5538 | 3005 | again: |
5d4f98a2 | 3006 | split = 1; |
cc0c5538 | 3007 | l = path->nodes[0]; |
eb60ceac | 3008 | slot = path->slots[0]; |
5f39d397 | 3009 | nritems = btrfs_header_nritems(l); |
d397712b | 3010 | mid = (nritems + 1) / 2; |
54aa1f4d | 3011 | |
5d4f98a2 YZ |
3012 | if (mid <= slot) { |
3013 | if (nritems == 1 || | |
3014 | leaf_space_used(l, mid, nritems - mid) + data_size > | |
3015 | BTRFS_LEAF_DATA_SIZE(root)) { | |
3016 | if (slot >= nritems) { | |
3017 | split = 0; | |
3018 | } else { | |
3019 | mid = slot; | |
3020 | if (mid != nritems && | |
3021 | leaf_space_used(l, mid, nritems - mid) + | |
3022 | data_size > BTRFS_LEAF_DATA_SIZE(root)) { | |
99d8f83c CM |
3023 | if (data_size && !tried_avoid_double) |
3024 | goto push_for_double; | |
5d4f98a2 YZ |
3025 | split = 2; |
3026 | } | |
3027 | } | |
3028 | } | |
3029 | } else { | |
3030 | if (leaf_space_used(l, 0, mid) + data_size > | |
3031 | BTRFS_LEAF_DATA_SIZE(root)) { | |
3032 | if (!extend && data_size && slot == 0) { | |
3033 | split = 0; | |
3034 | } else if ((extend || !data_size) && slot == 0) { | |
3035 | mid = 1; | |
3036 | } else { | |
3037 | mid = slot; | |
3038 | if (mid != nritems && | |
3039 | leaf_space_used(l, mid, nritems - mid) + | |
3040 | data_size > BTRFS_LEAF_DATA_SIZE(root)) { | |
99d8f83c CM |
3041 | if (data_size && !tried_avoid_double) |
3042 | goto push_for_double; | |
5d4f98a2 YZ |
3043 | split = 2 ; |
3044 | } | |
3045 | } | |
3046 | } | |
3047 | } | |
3048 | ||
3049 | if (split == 0) | |
3050 | btrfs_cpu_key_to_disk(&disk_key, ins_key); | |
3051 | else | |
3052 | btrfs_item_key(l, &disk_key, mid); | |
3053 | ||
3054 | right = btrfs_alloc_free_block(trans, root, root->leafsize, 0, | |
31840ae1 | 3055 | root->root_key.objectid, |
5d4f98a2 | 3056 | &disk_key, 0, l->start, 0); |
f0486c68 | 3057 | if (IS_ERR(right)) |
5f39d397 | 3058 | return PTR_ERR(right); |
f0486c68 YZ |
3059 | |
3060 | root_add_used(root, root->leafsize); | |
5f39d397 CM |
3061 | |
3062 | memset_extent_buffer(right, 0, 0, sizeof(struct btrfs_header)); | |
db94535d | 3063 | btrfs_set_header_bytenr(right, right->start); |
5f39d397 | 3064 | btrfs_set_header_generation(right, trans->transid); |
5d4f98a2 | 3065 | btrfs_set_header_backref_rev(right, BTRFS_MIXED_BACKREF_REV); |
5f39d397 CM |
3066 | btrfs_set_header_owner(right, root->root_key.objectid); |
3067 | btrfs_set_header_level(right, 0); | |
3068 | write_extent_buffer(right, root->fs_info->fsid, | |
3069 | (unsigned long)btrfs_header_fsid(right), | |
3070 | BTRFS_FSID_SIZE); | |
e17cade2 CM |
3071 | |
3072 | write_extent_buffer(right, root->fs_info->chunk_tree_uuid, | |
3073 | (unsigned long)btrfs_header_chunk_tree_uuid(right), | |
3074 | BTRFS_UUID_SIZE); | |
44871b1b | 3075 | |
5d4f98a2 YZ |
3076 | if (split == 0) { |
3077 | if (mid <= slot) { | |
3078 | btrfs_set_header_nritems(right, 0); | |
3079 | wret = insert_ptr(trans, root, path, | |
3080 | &disk_key, right->start, | |
3081 | path->slots[1] + 1, 1); | |
3082 | if (wret) | |
3083 | ret = wret; | |
925baedd | 3084 | |
5d4f98a2 YZ |
3085 | btrfs_tree_unlock(path->nodes[0]); |
3086 | free_extent_buffer(path->nodes[0]); | |
3087 | path->nodes[0] = right; | |
3088 | path->slots[0] = 0; | |
3089 | path->slots[1] += 1; | |
3090 | } else { | |
3091 | btrfs_set_header_nritems(right, 0); | |
3092 | wret = insert_ptr(trans, root, path, | |
3093 | &disk_key, | |
3094 | right->start, | |
3095 | path->slots[1], 1); | |
3096 | if (wret) | |
3097 | ret = wret; | |
3098 | btrfs_tree_unlock(path->nodes[0]); | |
3099 | free_extent_buffer(path->nodes[0]); | |
3100 | path->nodes[0] = right; | |
3101 | path->slots[0] = 0; | |
3102 | if (path->slots[1] == 0) { | |
3103 | wret = fixup_low_keys(trans, root, | |
3104 | path, &disk_key, 1); | |
d4dbff95 CM |
3105 | if (wret) |
3106 | ret = wret; | |
5ee78ac7 | 3107 | } |
d4dbff95 | 3108 | } |
5d4f98a2 YZ |
3109 | btrfs_mark_buffer_dirty(right); |
3110 | return ret; | |
d4dbff95 | 3111 | } |
74123bd7 | 3112 | |
44871b1b | 3113 | ret = copy_for_split(trans, root, path, l, right, slot, mid, nritems); |
31840ae1 ZY |
3114 | BUG_ON(ret); |
3115 | ||
5d4f98a2 | 3116 | if (split == 2) { |
cc0c5538 CM |
3117 | BUG_ON(num_doubles != 0); |
3118 | num_doubles++; | |
3119 | goto again; | |
a429e513 | 3120 | } |
44871b1b | 3121 | |
be0e5c09 | 3122 | return ret; |
99d8f83c CM |
3123 | |
3124 | push_for_double: | |
3125 | push_for_double_split(trans, root, path, data_size); | |
3126 | tried_avoid_double = 1; | |
3127 | if (btrfs_leaf_free_space(root, path->nodes[0]) >= data_size) | |
3128 | return 0; | |
3129 | goto again; | |
be0e5c09 CM |
3130 | } |
3131 | ||
ad48fd75 YZ |
3132 | static noinline int setup_leaf_for_split(struct btrfs_trans_handle *trans, |
3133 | struct btrfs_root *root, | |
3134 | struct btrfs_path *path, int ins_len) | |
459931ec | 3135 | { |
ad48fd75 | 3136 | struct btrfs_key key; |
459931ec | 3137 | struct extent_buffer *leaf; |
ad48fd75 YZ |
3138 | struct btrfs_file_extent_item *fi; |
3139 | u64 extent_len = 0; | |
3140 | u32 item_size; | |
3141 | int ret; | |
459931ec CM |
3142 | |
3143 | leaf = path->nodes[0]; | |
ad48fd75 YZ |
3144 | btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
3145 | ||
3146 | BUG_ON(key.type != BTRFS_EXTENT_DATA_KEY && | |
3147 | key.type != BTRFS_EXTENT_CSUM_KEY); | |
3148 | ||
3149 | if (btrfs_leaf_free_space(root, leaf) >= ins_len) | |
3150 | return 0; | |
459931ec CM |
3151 | |
3152 | item_size = btrfs_item_size_nr(leaf, path->slots[0]); | |
ad48fd75 YZ |
3153 | if (key.type == BTRFS_EXTENT_DATA_KEY) { |
3154 | fi = btrfs_item_ptr(leaf, path->slots[0], | |
3155 | struct btrfs_file_extent_item); | |
3156 | extent_len = btrfs_file_extent_num_bytes(leaf, fi); | |
3157 | } | |
459931ec CM |
3158 | btrfs_release_path(root, path); |
3159 | ||
459931ec | 3160 | path->keep_locks = 1; |
ad48fd75 YZ |
3161 | path->search_for_split = 1; |
3162 | ret = btrfs_search_slot(trans, root, &key, path, 0, 1); | |
459931ec | 3163 | path->search_for_split = 0; |
ad48fd75 YZ |
3164 | if (ret < 0) |
3165 | goto err; | |
459931ec | 3166 | |
ad48fd75 YZ |
3167 | ret = -EAGAIN; |
3168 | leaf = path->nodes[0]; | |
459931ec | 3169 | /* if our item isn't there or got smaller, return now */ |
ad48fd75 YZ |
3170 | if (ret > 0 || item_size != btrfs_item_size_nr(leaf, path->slots[0])) |
3171 | goto err; | |
3172 | ||
109f6aef CM |
3173 | /* the leaf has changed, it now has room. return now */ |
3174 | if (btrfs_leaf_free_space(root, path->nodes[0]) >= ins_len) | |
3175 | goto err; | |
3176 | ||
ad48fd75 YZ |
3177 | if (key.type == BTRFS_EXTENT_DATA_KEY) { |
3178 | fi = btrfs_item_ptr(leaf, path->slots[0], | |
3179 | struct btrfs_file_extent_item); | |
3180 | if (extent_len != btrfs_file_extent_num_bytes(leaf, fi)) | |
3181 | goto err; | |
459931ec CM |
3182 | } |
3183 | ||
b9473439 | 3184 | btrfs_set_path_blocking(path); |
ad48fd75 | 3185 | ret = split_leaf(trans, root, &key, path, ins_len, 1); |
f0486c68 YZ |
3186 | if (ret) |
3187 | goto err; | |
459931ec | 3188 | |
ad48fd75 | 3189 | path->keep_locks = 0; |
b9473439 | 3190 | btrfs_unlock_up_safe(path, 1); |
ad48fd75 YZ |
3191 | return 0; |
3192 | err: | |
3193 | path->keep_locks = 0; | |
3194 | return ret; | |
3195 | } | |
3196 | ||
3197 | static noinline int split_item(struct btrfs_trans_handle *trans, | |
3198 | struct btrfs_root *root, | |
3199 | struct btrfs_path *path, | |
3200 | struct btrfs_key *new_key, | |
3201 | unsigned long split_offset) | |
3202 | { | |
3203 | struct extent_buffer *leaf; | |
3204 | struct btrfs_item *item; | |
3205 | struct btrfs_item *new_item; | |
3206 | int slot; | |
3207 | char *buf; | |
3208 | u32 nritems; | |
3209 | u32 item_size; | |
3210 | u32 orig_offset; | |
3211 | struct btrfs_disk_key disk_key; | |
3212 | ||
b9473439 CM |
3213 | leaf = path->nodes[0]; |
3214 | BUG_ON(btrfs_leaf_free_space(root, leaf) < sizeof(struct btrfs_item)); | |
3215 | ||
b4ce94de CM |
3216 | btrfs_set_path_blocking(path); |
3217 | ||
459931ec CM |
3218 | item = btrfs_item_nr(leaf, path->slots[0]); |
3219 | orig_offset = btrfs_item_offset(leaf, item); | |
3220 | item_size = btrfs_item_size(leaf, item); | |
3221 | ||
459931ec | 3222 | buf = kmalloc(item_size, GFP_NOFS); |
ad48fd75 YZ |
3223 | if (!buf) |
3224 | return -ENOMEM; | |
3225 | ||
459931ec CM |
3226 | read_extent_buffer(leaf, buf, btrfs_item_ptr_offset(leaf, |
3227 | path->slots[0]), item_size); | |
459931ec | 3228 | |
ad48fd75 | 3229 | slot = path->slots[0] + 1; |
459931ec | 3230 | nritems = btrfs_header_nritems(leaf); |
459931ec CM |
3231 | if (slot != nritems) { |
3232 | /* shift the items */ | |
3233 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + 1), | |
ad48fd75 YZ |
3234 | btrfs_item_nr_offset(slot), |
3235 | (nritems - slot) * sizeof(struct btrfs_item)); | |
459931ec CM |
3236 | } |
3237 | ||
3238 | btrfs_cpu_key_to_disk(&disk_key, new_key); | |
3239 | btrfs_set_item_key(leaf, &disk_key, slot); | |
3240 | ||
3241 | new_item = btrfs_item_nr(leaf, slot); | |
3242 | ||
3243 | btrfs_set_item_offset(leaf, new_item, orig_offset); | |
3244 | btrfs_set_item_size(leaf, new_item, item_size - split_offset); | |
3245 | ||
3246 | btrfs_set_item_offset(leaf, item, | |
3247 | orig_offset + item_size - split_offset); | |
3248 | btrfs_set_item_size(leaf, item, split_offset); | |
3249 | ||
3250 | btrfs_set_header_nritems(leaf, nritems + 1); | |
3251 | ||
3252 | /* write the data for the start of the original item */ | |
3253 | write_extent_buffer(leaf, buf, | |
3254 | btrfs_item_ptr_offset(leaf, path->slots[0]), | |
3255 | split_offset); | |
3256 | ||
3257 | /* write the data for the new item */ | |
3258 | write_extent_buffer(leaf, buf + split_offset, | |
3259 | btrfs_item_ptr_offset(leaf, slot), | |
3260 | item_size - split_offset); | |
3261 | btrfs_mark_buffer_dirty(leaf); | |
3262 | ||
ad48fd75 | 3263 | BUG_ON(btrfs_leaf_free_space(root, leaf) < 0); |
459931ec | 3264 | kfree(buf); |
ad48fd75 YZ |
3265 | return 0; |
3266 | } | |
3267 | ||
3268 | /* | |
3269 | * This function splits a single item into two items, | |
3270 | * giving 'new_key' to the new item and splitting the | |
3271 | * old one at split_offset (from the start of the item). | |
3272 | * | |
3273 | * The path may be released by this operation. After | |
3274 | * the split, the path is pointing to the old item. The | |
3275 | * new item is going to be in the same node as the old one. | |
3276 | * | |
3277 | * Note, the item being split must be smaller enough to live alone on | |
3278 | * a tree block with room for one extra struct btrfs_item | |
3279 | * | |
3280 | * This allows us to split the item in place, keeping a lock on the | |
3281 | * leaf the entire time. | |
3282 | */ | |
3283 | int btrfs_split_item(struct btrfs_trans_handle *trans, | |
3284 | struct btrfs_root *root, | |
3285 | struct btrfs_path *path, | |
3286 | struct btrfs_key *new_key, | |
3287 | unsigned long split_offset) | |
3288 | { | |
3289 | int ret; | |
3290 | ret = setup_leaf_for_split(trans, root, path, | |
3291 | sizeof(struct btrfs_item)); | |
3292 | if (ret) | |
3293 | return ret; | |
3294 | ||
3295 | ret = split_item(trans, root, path, new_key, split_offset); | |
459931ec CM |
3296 | return ret; |
3297 | } | |
3298 | ||
ad48fd75 YZ |
3299 | /* |
3300 | * This function duplicate a item, giving 'new_key' to the new item. | |
3301 | * It guarantees both items live in the same tree leaf and the new item | |
3302 | * is contiguous with the original item. | |
3303 | * | |
3304 | * This allows us to split file extent in place, keeping a lock on the | |
3305 | * leaf the entire time. | |
3306 | */ | |
3307 | int btrfs_duplicate_item(struct btrfs_trans_handle *trans, | |
3308 | struct btrfs_root *root, | |
3309 | struct btrfs_path *path, | |
3310 | struct btrfs_key *new_key) | |
3311 | { | |
3312 | struct extent_buffer *leaf; | |
3313 | int ret; | |
3314 | u32 item_size; | |
3315 | ||
3316 | leaf = path->nodes[0]; | |
3317 | item_size = btrfs_item_size_nr(leaf, path->slots[0]); | |
3318 | ret = setup_leaf_for_split(trans, root, path, | |
3319 | item_size + sizeof(struct btrfs_item)); | |
3320 | if (ret) | |
3321 | return ret; | |
3322 | ||
3323 | path->slots[0]++; | |
3324 | ret = setup_items_for_insert(trans, root, path, new_key, &item_size, | |
3325 | item_size, item_size + | |
3326 | sizeof(struct btrfs_item), 1); | |
3327 | BUG_ON(ret); | |
3328 | ||
3329 | leaf = path->nodes[0]; | |
3330 | memcpy_extent_buffer(leaf, | |
3331 | btrfs_item_ptr_offset(leaf, path->slots[0]), | |
3332 | btrfs_item_ptr_offset(leaf, path->slots[0] - 1), | |
3333 | item_size); | |
3334 | return 0; | |
3335 | } | |
3336 | ||
d352ac68 CM |
3337 | /* |
3338 | * make the item pointed to by the path smaller. new_size indicates | |
3339 | * how small to make it, and from_end tells us if we just chop bytes | |
3340 | * off the end of the item or if we shift the item to chop bytes off | |
3341 | * the front. | |
3342 | */ | |
b18c6685 CM |
3343 | int btrfs_truncate_item(struct btrfs_trans_handle *trans, |
3344 | struct btrfs_root *root, | |
3345 | struct btrfs_path *path, | |
179e29e4 | 3346 | u32 new_size, int from_end) |
b18c6685 CM |
3347 | { |
3348 | int ret = 0; | |
3349 | int slot; | |
5f39d397 CM |
3350 | struct extent_buffer *leaf; |
3351 | struct btrfs_item *item; | |
b18c6685 CM |
3352 | u32 nritems; |
3353 | unsigned int data_end; | |
3354 | unsigned int old_data_start; | |
3355 | unsigned int old_size; | |
3356 | unsigned int size_diff; | |
3357 | int i; | |
3358 | ||
5f39d397 | 3359 | leaf = path->nodes[0]; |
179e29e4 CM |
3360 | slot = path->slots[0]; |
3361 | ||
3362 | old_size = btrfs_item_size_nr(leaf, slot); | |
3363 | if (old_size == new_size) | |
3364 | return 0; | |
b18c6685 | 3365 | |
5f39d397 | 3366 | nritems = btrfs_header_nritems(leaf); |
b18c6685 CM |
3367 | data_end = leaf_data_end(root, leaf); |
3368 | ||
5f39d397 | 3369 | old_data_start = btrfs_item_offset_nr(leaf, slot); |
179e29e4 | 3370 | |
b18c6685 CM |
3371 | size_diff = old_size - new_size; |
3372 | ||
3373 | BUG_ON(slot < 0); | |
3374 | BUG_ON(slot >= nritems); | |
3375 | ||
3376 | /* | |
3377 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
3378 | */ | |
3379 | /* first correct the data pointers */ | |
3380 | for (i = slot; i < nritems; i++) { | |
5f39d397 CM |
3381 | u32 ioff; |
3382 | item = btrfs_item_nr(leaf, i); | |
db94535d CM |
3383 | |
3384 | if (!leaf->map_token) { | |
3385 | map_extent_buffer(leaf, (unsigned long)item, | |
3386 | sizeof(struct btrfs_item), | |
3387 | &leaf->map_token, &leaf->kaddr, | |
3388 | &leaf->map_start, &leaf->map_len, | |
3389 | KM_USER1); | |
3390 | } | |
3391 | ||
5f39d397 CM |
3392 | ioff = btrfs_item_offset(leaf, item); |
3393 | btrfs_set_item_offset(leaf, item, ioff + size_diff); | |
b18c6685 | 3394 | } |
db94535d CM |
3395 | |
3396 | if (leaf->map_token) { | |
3397 | unmap_extent_buffer(leaf, leaf->map_token, KM_USER1); | |
3398 | leaf->map_token = NULL; | |
3399 | } | |
3400 | ||
b18c6685 | 3401 | /* shift the data */ |
179e29e4 CM |
3402 | if (from_end) { |
3403 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + | |
3404 | data_end + size_diff, btrfs_leaf_data(leaf) + | |
3405 | data_end, old_data_start + new_size - data_end); | |
3406 | } else { | |
3407 | struct btrfs_disk_key disk_key; | |
3408 | u64 offset; | |
3409 | ||
3410 | btrfs_item_key(leaf, &disk_key, slot); | |
3411 | ||
3412 | if (btrfs_disk_key_type(&disk_key) == BTRFS_EXTENT_DATA_KEY) { | |
3413 | unsigned long ptr; | |
3414 | struct btrfs_file_extent_item *fi; | |
3415 | ||
3416 | fi = btrfs_item_ptr(leaf, slot, | |
3417 | struct btrfs_file_extent_item); | |
3418 | fi = (struct btrfs_file_extent_item *)( | |
3419 | (unsigned long)fi - size_diff); | |
3420 | ||
3421 | if (btrfs_file_extent_type(leaf, fi) == | |
3422 | BTRFS_FILE_EXTENT_INLINE) { | |
3423 | ptr = btrfs_item_ptr_offset(leaf, slot); | |
3424 | memmove_extent_buffer(leaf, ptr, | |
d397712b CM |
3425 | (unsigned long)fi, |
3426 | offsetof(struct btrfs_file_extent_item, | |
179e29e4 CM |
3427 | disk_bytenr)); |
3428 | } | |
3429 | } | |
3430 | ||
3431 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + | |
3432 | data_end + size_diff, btrfs_leaf_data(leaf) + | |
3433 | data_end, old_data_start - data_end); | |
3434 | ||
3435 | offset = btrfs_disk_key_offset(&disk_key); | |
3436 | btrfs_set_disk_key_offset(&disk_key, offset + size_diff); | |
3437 | btrfs_set_item_key(leaf, &disk_key, slot); | |
3438 | if (slot == 0) | |
3439 | fixup_low_keys(trans, root, path, &disk_key, 1); | |
3440 | } | |
5f39d397 CM |
3441 | |
3442 | item = btrfs_item_nr(leaf, slot); | |
3443 | btrfs_set_item_size(leaf, item, new_size); | |
3444 | btrfs_mark_buffer_dirty(leaf); | |
b18c6685 CM |
3445 | |
3446 | ret = 0; | |
5f39d397 CM |
3447 | if (btrfs_leaf_free_space(root, leaf) < 0) { |
3448 | btrfs_print_leaf(root, leaf); | |
b18c6685 | 3449 | BUG(); |
5f39d397 | 3450 | } |
b18c6685 CM |
3451 | return ret; |
3452 | } | |
3453 | ||
d352ac68 CM |
3454 | /* |
3455 | * make the item pointed to by the path bigger, data_size is the new size. | |
3456 | */ | |
5f39d397 CM |
3457 | int btrfs_extend_item(struct btrfs_trans_handle *trans, |
3458 | struct btrfs_root *root, struct btrfs_path *path, | |
3459 | u32 data_size) | |
6567e837 CM |
3460 | { |
3461 | int ret = 0; | |
3462 | int slot; | |
5f39d397 CM |
3463 | struct extent_buffer *leaf; |
3464 | struct btrfs_item *item; | |
6567e837 CM |
3465 | u32 nritems; |
3466 | unsigned int data_end; | |
3467 | unsigned int old_data; | |
3468 | unsigned int old_size; | |
3469 | int i; | |
3470 | ||
5f39d397 | 3471 | leaf = path->nodes[0]; |
6567e837 | 3472 | |
5f39d397 | 3473 | nritems = btrfs_header_nritems(leaf); |
6567e837 CM |
3474 | data_end = leaf_data_end(root, leaf); |
3475 | ||
5f39d397 CM |
3476 | if (btrfs_leaf_free_space(root, leaf) < data_size) { |
3477 | btrfs_print_leaf(root, leaf); | |
6567e837 | 3478 | BUG(); |
5f39d397 | 3479 | } |
6567e837 | 3480 | slot = path->slots[0]; |
5f39d397 | 3481 | old_data = btrfs_item_end_nr(leaf, slot); |
6567e837 CM |
3482 | |
3483 | BUG_ON(slot < 0); | |
3326d1b0 CM |
3484 | if (slot >= nritems) { |
3485 | btrfs_print_leaf(root, leaf); | |
d397712b CM |
3486 | printk(KERN_CRIT "slot %d too large, nritems %d\n", |
3487 | slot, nritems); | |
3326d1b0 CM |
3488 | BUG_ON(1); |
3489 | } | |
6567e837 CM |
3490 | |
3491 | /* | |
3492 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
3493 | */ | |
3494 | /* first correct the data pointers */ | |
3495 | for (i = slot; i < nritems; i++) { | |
5f39d397 CM |
3496 | u32 ioff; |
3497 | item = btrfs_item_nr(leaf, i); | |
db94535d CM |
3498 | |
3499 | if (!leaf->map_token) { | |
3500 | map_extent_buffer(leaf, (unsigned long)item, | |
3501 | sizeof(struct btrfs_item), | |
3502 | &leaf->map_token, &leaf->kaddr, | |
3503 | &leaf->map_start, &leaf->map_len, | |
3504 | KM_USER1); | |
3505 | } | |
5f39d397 CM |
3506 | ioff = btrfs_item_offset(leaf, item); |
3507 | btrfs_set_item_offset(leaf, item, ioff - data_size); | |
6567e837 | 3508 | } |
5f39d397 | 3509 | |
db94535d CM |
3510 | if (leaf->map_token) { |
3511 | unmap_extent_buffer(leaf, leaf->map_token, KM_USER1); | |
3512 | leaf->map_token = NULL; | |
3513 | } | |
3514 | ||
6567e837 | 3515 | /* shift the data */ |
5f39d397 | 3516 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + |
6567e837 CM |
3517 | data_end - data_size, btrfs_leaf_data(leaf) + |
3518 | data_end, old_data - data_end); | |
5f39d397 | 3519 | |
6567e837 | 3520 | data_end = old_data; |
5f39d397 CM |
3521 | old_size = btrfs_item_size_nr(leaf, slot); |
3522 | item = btrfs_item_nr(leaf, slot); | |
3523 | btrfs_set_item_size(leaf, item, old_size + data_size); | |
3524 | btrfs_mark_buffer_dirty(leaf); | |
6567e837 CM |
3525 | |
3526 | ret = 0; | |
5f39d397 CM |
3527 | if (btrfs_leaf_free_space(root, leaf) < 0) { |
3528 | btrfs_print_leaf(root, leaf); | |
6567e837 | 3529 | BUG(); |
5f39d397 | 3530 | } |
6567e837 CM |
3531 | return ret; |
3532 | } | |
3533 | ||
f3465ca4 JB |
3534 | /* |
3535 | * Given a key and some data, insert items into the tree. | |
3536 | * This does all the path init required, making room in the tree if needed. | |
3537 | * Returns the number of keys that were inserted. | |
3538 | */ | |
3539 | int btrfs_insert_some_items(struct btrfs_trans_handle *trans, | |
3540 | struct btrfs_root *root, | |
3541 | struct btrfs_path *path, | |
3542 | struct btrfs_key *cpu_key, u32 *data_size, | |
3543 | int nr) | |
3544 | { | |
3545 | struct extent_buffer *leaf; | |
3546 | struct btrfs_item *item; | |
3547 | int ret = 0; | |
3548 | int slot; | |
f3465ca4 JB |
3549 | int i; |
3550 | u32 nritems; | |
3551 | u32 total_data = 0; | |
3552 | u32 total_size = 0; | |
3553 | unsigned int data_end; | |
3554 | struct btrfs_disk_key disk_key; | |
3555 | struct btrfs_key found_key; | |
3556 | ||
87b29b20 YZ |
3557 | for (i = 0; i < nr; i++) { |
3558 | if (total_size + data_size[i] + sizeof(struct btrfs_item) > | |
3559 | BTRFS_LEAF_DATA_SIZE(root)) { | |
3560 | break; | |
3561 | nr = i; | |
3562 | } | |
f3465ca4 | 3563 | total_data += data_size[i]; |
87b29b20 YZ |
3564 | total_size += data_size[i] + sizeof(struct btrfs_item); |
3565 | } | |
3566 | BUG_ON(nr == 0); | |
f3465ca4 | 3567 | |
f3465ca4 JB |
3568 | ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1); |
3569 | if (ret == 0) | |
3570 | return -EEXIST; | |
3571 | if (ret < 0) | |
3572 | goto out; | |
3573 | ||
f3465ca4 JB |
3574 | leaf = path->nodes[0]; |
3575 | ||
3576 | nritems = btrfs_header_nritems(leaf); | |
3577 | data_end = leaf_data_end(root, leaf); | |
3578 | ||
3579 | if (btrfs_leaf_free_space(root, leaf) < total_size) { | |
3580 | for (i = nr; i >= 0; i--) { | |
3581 | total_data -= data_size[i]; | |
3582 | total_size -= data_size[i] + sizeof(struct btrfs_item); | |
3583 | if (total_size < btrfs_leaf_free_space(root, leaf)) | |
3584 | break; | |
3585 | } | |
3586 | nr = i; | |
3587 | } | |
3588 | ||
3589 | slot = path->slots[0]; | |
3590 | BUG_ON(slot < 0); | |
3591 | ||
3592 | if (slot != nritems) { | |
3593 | unsigned int old_data = btrfs_item_end_nr(leaf, slot); | |
3594 | ||
3595 | item = btrfs_item_nr(leaf, slot); | |
3596 | btrfs_item_key_to_cpu(leaf, &found_key, slot); | |
3597 | ||
3598 | /* figure out how many keys we can insert in here */ | |
3599 | total_data = data_size[0]; | |
3600 | for (i = 1; i < nr; i++) { | |
5d4f98a2 | 3601 | if (btrfs_comp_cpu_keys(&found_key, cpu_key + i) <= 0) |
f3465ca4 JB |
3602 | break; |
3603 | total_data += data_size[i]; | |
3604 | } | |
3605 | nr = i; | |
3606 | ||
3607 | if (old_data < data_end) { | |
3608 | btrfs_print_leaf(root, leaf); | |
d397712b | 3609 | printk(KERN_CRIT "slot %d old_data %d data_end %d\n", |
f3465ca4 JB |
3610 | slot, old_data, data_end); |
3611 | BUG_ON(1); | |
3612 | } | |
3613 | /* | |
3614 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
3615 | */ | |
3616 | /* first correct the data pointers */ | |
3617 | WARN_ON(leaf->map_token); | |
3618 | for (i = slot; i < nritems; i++) { | |
3619 | u32 ioff; | |
3620 | ||
3621 | item = btrfs_item_nr(leaf, i); | |
3622 | if (!leaf->map_token) { | |
3623 | map_extent_buffer(leaf, (unsigned long)item, | |
3624 | sizeof(struct btrfs_item), | |
3625 | &leaf->map_token, &leaf->kaddr, | |
3626 | &leaf->map_start, &leaf->map_len, | |
3627 | KM_USER1); | |
3628 | } | |
3629 | ||
3630 | ioff = btrfs_item_offset(leaf, item); | |
3631 | btrfs_set_item_offset(leaf, item, ioff - total_data); | |
3632 | } | |
3633 | if (leaf->map_token) { | |
3634 | unmap_extent_buffer(leaf, leaf->map_token, KM_USER1); | |
3635 | leaf->map_token = NULL; | |
3636 | } | |
3637 | ||
3638 | /* shift the items */ | |
3639 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr), | |
3640 | btrfs_item_nr_offset(slot), | |
3641 | (nritems - slot) * sizeof(struct btrfs_item)); | |
3642 | ||
3643 | /* shift the data */ | |
3644 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + | |
3645 | data_end - total_data, btrfs_leaf_data(leaf) + | |
3646 | data_end, old_data - data_end); | |
3647 | data_end = old_data; | |
3648 | } else { | |
3649 | /* | |
3650 | * this sucks but it has to be done, if we are inserting at | |
3651 | * the end of the leaf only insert 1 of the items, since we | |
3652 | * have no way of knowing whats on the next leaf and we'd have | |
3653 | * to drop our current locks to figure it out | |
3654 | */ | |
3655 | nr = 1; | |
3656 | } | |
3657 | ||
3658 | /* setup the item for the new data */ | |
3659 | for (i = 0; i < nr; i++) { | |
3660 | btrfs_cpu_key_to_disk(&disk_key, cpu_key + i); | |
3661 | btrfs_set_item_key(leaf, &disk_key, slot + i); | |
3662 | item = btrfs_item_nr(leaf, slot + i); | |
3663 | btrfs_set_item_offset(leaf, item, data_end - data_size[i]); | |
3664 | data_end -= data_size[i]; | |
3665 | btrfs_set_item_size(leaf, item, data_size[i]); | |
3666 | } | |
3667 | btrfs_set_header_nritems(leaf, nritems + nr); | |
3668 | btrfs_mark_buffer_dirty(leaf); | |
3669 | ||
3670 | ret = 0; | |
3671 | if (slot == 0) { | |
3672 | btrfs_cpu_key_to_disk(&disk_key, cpu_key); | |
3673 | ret = fixup_low_keys(trans, root, path, &disk_key, 1); | |
3674 | } | |
3675 | ||
3676 | if (btrfs_leaf_free_space(root, leaf) < 0) { | |
3677 | btrfs_print_leaf(root, leaf); | |
3678 | BUG(); | |
3679 | } | |
3680 | out: | |
3681 | if (!ret) | |
3682 | ret = nr; | |
3683 | return ret; | |
3684 | } | |
3685 | ||
74123bd7 | 3686 | /* |
44871b1b CM |
3687 | * this is a helper for btrfs_insert_empty_items, the main goal here is |
3688 | * to save stack depth by doing the bulk of the work in a function | |
3689 | * that doesn't call btrfs_search_slot | |
74123bd7 | 3690 | */ |
44871b1b CM |
3691 | static noinline_for_stack int |
3692 | setup_items_for_insert(struct btrfs_trans_handle *trans, | |
3693 | struct btrfs_root *root, struct btrfs_path *path, | |
3694 | struct btrfs_key *cpu_key, u32 *data_size, | |
3695 | u32 total_data, u32 total_size, int nr) | |
be0e5c09 | 3696 | { |
5f39d397 | 3697 | struct btrfs_item *item; |
9c58309d | 3698 | int i; |
7518a238 | 3699 | u32 nritems; |
be0e5c09 | 3700 | unsigned int data_end; |
e2fa7227 | 3701 | struct btrfs_disk_key disk_key; |
44871b1b CM |
3702 | int ret; |
3703 | struct extent_buffer *leaf; | |
3704 | int slot; | |
e2fa7227 | 3705 | |
5f39d397 | 3706 | leaf = path->nodes[0]; |
44871b1b | 3707 | slot = path->slots[0]; |
74123bd7 | 3708 | |
5f39d397 | 3709 | nritems = btrfs_header_nritems(leaf); |
123abc88 | 3710 | data_end = leaf_data_end(root, leaf); |
eb60ceac | 3711 | |
f25956cc | 3712 | if (btrfs_leaf_free_space(root, leaf) < total_size) { |
3326d1b0 | 3713 | btrfs_print_leaf(root, leaf); |
d397712b | 3714 | printk(KERN_CRIT "not enough freespace need %u have %d\n", |
9c58309d | 3715 | total_size, btrfs_leaf_free_space(root, leaf)); |
be0e5c09 | 3716 | BUG(); |
d4dbff95 | 3717 | } |
5f39d397 | 3718 | |
be0e5c09 | 3719 | if (slot != nritems) { |
5f39d397 | 3720 | unsigned int old_data = btrfs_item_end_nr(leaf, slot); |
be0e5c09 | 3721 | |
5f39d397 CM |
3722 | if (old_data < data_end) { |
3723 | btrfs_print_leaf(root, leaf); | |
d397712b | 3724 | printk(KERN_CRIT "slot %d old_data %d data_end %d\n", |
5f39d397 CM |
3725 | slot, old_data, data_end); |
3726 | BUG_ON(1); | |
3727 | } | |
be0e5c09 CM |
3728 | /* |
3729 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
3730 | */ | |
3731 | /* first correct the data pointers */ | |
db94535d | 3732 | WARN_ON(leaf->map_token); |
0783fcfc | 3733 | for (i = slot; i < nritems; i++) { |
5f39d397 | 3734 | u32 ioff; |
db94535d | 3735 | |
5f39d397 | 3736 | item = btrfs_item_nr(leaf, i); |
db94535d CM |
3737 | if (!leaf->map_token) { |
3738 | map_extent_buffer(leaf, (unsigned long)item, | |
3739 | sizeof(struct btrfs_item), | |
3740 | &leaf->map_token, &leaf->kaddr, | |
3741 | &leaf->map_start, &leaf->map_len, | |
3742 | KM_USER1); | |
3743 | } | |
3744 | ||
5f39d397 | 3745 | ioff = btrfs_item_offset(leaf, item); |
9c58309d | 3746 | btrfs_set_item_offset(leaf, item, ioff - total_data); |
0783fcfc | 3747 | } |
db94535d CM |
3748 | if (leaf->map_token) { |
3749 | unmap_extent_buffer(leaf, leaf->map_token, KM_USER1); | |
3750 | leaf->map_token = NULL; | |
3751 | } | |
be0e5c09 CM |
3752 | |
3753 | /* shift the items */ | |
9c58309d | 3754 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr), |
5f39d397 | 3755 | btrfs_item_nr_offset(slot), |
d6025579 | 3756 | (nritems - slot) * sizeof(struct btrfs_item)); |
be0e5c09 CM |
3757 | |
3758 | /* shift the data */ | |
5f39d397 | 3759 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + |
9c58309d | 3760 | data_end - total_data, btrfs_leaf_data(leaf) + |
d6025579 | 3761 | data_end, old_data - data_end); |
be0e5c09 CM |
3762 | data_end = old_data; |
3763 | } | |
5f39d397 | 3764 | |
62e2749e | 3765 | /* setup the item for the new data */ |
9c58309d CM |
3766 | for (i = 0; i < nr; i++) { |
3767 | btrfs_cpu_key_to_disk(&disk_key, cpu_key + i); | |
3768 | btrfs_set_item_key(leaf, &disk_key, slot + i); | |
3769 | item = btrfs_item_nr(leaf, slot + i); | |
3770 | btrfs_set_item_offset(leaf, item, data_end - data_size[i]); | |
3771 | data_end -= data_size[i]; | |
3772 | btrfs_set_item_size(leaf, item, data_size[i]); | |
3773 | } | |
44871b1b | 3774 | |
9c58309d | 3775 | btrfs_set_header_nritems(leaf, nritems + nr); |
aa5d6bed CM |
3776 | |
3777 | ret = 0; | |
5a01a2e3 | 3778 | if (slot == 0) { |
44871b1b | 3779 | struct btrfs_disk_key disk_key; |
5a01a2e3 | 3780 | btrfs_cpu_key_to_disk(&disk_key, cpu_key); |
e089f05c | 3781 | ret = fixup_low_keys(trans, root, path, &disk_key, 1); |
5a01a2e3 | 3782 | } |
b9473439 CM |
3783 | btrfs_unlock_up_safe(path, 1); |
3784 | btrfs_mark_buffer_dirty(leaf); | |
aa5d6bed | 3785 | |
5f39d397 CM |
3786 | if (btrfs_leaf_free_space(root, leaf) < 0) { |
3787 | btrfs_print_leaf(root, leaf); | |
be0e5c09 | 3788 | BUG(); |
5f39d397 | 3789 | } |
44871b1b CM |
3790 | return ret; |
3791 | } | |
3792 | ||
3793 | /* | |
3794 | * Given a key and some data, insert items into the tree. | |
3795 | * This does all the path init required, making room in the tree if needed. | |
3796 | */ | |
3797 | int btrfs_insert_empty_items(struct btrfs_trans_handle *trans, | |
3798 | struct btrfs_root *root, | |
3799 | struct btrfs_path *path, | |
3800 | struct btrfs_key *cpu_key, u32 *data_size, | |
3801 | int nr) | |
3802 | { | |
44871b1b CM |
3803 | int ret = 0; |
3804 | int slot; | |
3805 | int i; | |
3806 | u32 total_size = 0; | |
3807 | u32 total_data = 0; | |
3808 | ||
3809 | for (i = 0; i < nr; i++) | |
3810 | total_data += data_size[i]; | |
3811 | ||
3812 | total_size = total_data + (nr * sizeof(struct btrfs_item)); | |
3813 | ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1); | |
3814 | if (ret == 0) | |
3815 | return -EEXIST; | |
3816 | if (ret < 0) | |
3817 | goto out; | |
3818 | ||
44871b1b CM |
3819 | slot = path->slots[0]; |
3820 | BUG_ON(slot < 0); | |
3821 | ||
3822 | ret = setup_items_for_insert(trans, root, path, cpu_key, data_size, | |
3823 | total_data, total_size, nr); | |
3824 | ||
ed2ff2cb | 3825 | out: |
62e2749e CM |
3826 | return ret; |
3827 | } | |
3828 | ||
3829 | /* | |
3830 | * Given a key and some data, insert an item into the tree. | |
3831 | * This does all the path init required, making room in the tree if needed. | |
3832 | */ | |
e089f05c CM |
3833 | int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root |
3834 | *root, struct btrfs_key *cpu_key, void *data, u32 | |
3835 | data_size) | |
62e2749e CM |
3836 | { |
3837 | int ret = 0; | |
2c90e5d6 | 3838 | struct btrfs_path *path; |
5f39d397 CM |
3839 | struct extent_buffer *leaf; |
3840 | unsigned long ptr; | |
62e2749e | 3841 | |
2c90e5d6 CM |
3842 | path = btrfs_alloc_path(); |
3843 | BUG_ON(!path); | |
2c90e5d6 | 3844 | ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size); |
62e2749e | 3845 | if (!ret) { |
5f39d397 CM |
3846 | leaf = path->nodes[0]; |
3847 | ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); | |
3848 | write_extent_buffer(leaf, data, ptr, data_size); | |
3849 | btrfs_mark_buffer_dirty(leaf); | |
62e2749e | 3850 | } |
2c90e5d6 | 3851 | btrfs_free_path(path); |
aa5d6bed | 3852 | return ret; |
be0e5c09 CM |
3853 | } |
3854 | ||
74123bd7 | 3855 | /* |
5de08d7d | 3856 | * delete the pointer from a given node. |
74123bd7 | 3857 | * |
d352ac68 CM |
3858 | * the tree should have been previously balanced so the deletion does not |
3859 | * empty a node. | |
74123bd7 | 3860 | */ |
e089f05c CM |
3861 | static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
3862 | struct btrfs_path *path, int level, int slot) | |
be0e5c09 | 3863 | { |
5f39d397 | 3864 | struct extent_buffer *parent = path->nodes[level]; |
7518a238 | 3865 | u32 nritems; |
aa5d6bed | 3866 | int ret = 0; |
bb803951 | 3867 | int wret; |
be0e5c09 | 3868 | |
5f39d397 | 3869 | nritems = btrfs_header_nritems(parent); |
d397712b | 3870 | if (slot != nritems - 1) { |
5f39d397 CM |
3871 | memmove_extent_buffer(parent, |
3872 | btrfs_node_key_ptr_offset(slot), | |
3873 | btrfs_node_key_ptr_offset(slot + 1), | |
d6025579 CM |
3874 | sizeof(struct btrfs_key_ptr) * |
3875 | (nritems - slot - 1)); | |
bb803951 | 3876 | } |
7518a238 | 3877 | nritems--; |
5f39d397 | 3878 | btrfs_set_header_nritems(parent, nritems); |
7518a238 | 3879 | if (nritems == 0 && parent == root->node) { |
5f39d397 | 3880 | BUG_ON(btrfs_header_level(root->node) != 1); |
bb803951 | 3881 | /* just turn the root into a leaf and break */ |
5f39d397 | 3882 | btrfs_set_header_level(root->node, 0); |
bb803951 | 3883 | } else if (slot == 0) { |
5f39d397 CM |
3884 | struct btrfs_disk_key disk_key; |
3885 | ||
3886 | btrfs_node_key(parent, &disk_key, 0); | |
3887 | wret = fixup_low_keys(trans, root, path, &disk_key, level + 1); | |
0f70abe2 CM |
3888 | if (wret) |
3889 | ret = wret; | |
be0e5c09 | 3890 | } |
d6025579 | 3891 | btrfs_mark_buffer_dirty(parent); |
aa5d6bed | 3892 | return ret; |
be0e5c09 CM |
3893 | } |
3894 | ||
323ac95b CM |
3895 | /* |
3896 | * a helper function to delete the leaf pointed to by path->slots[1] and | |
5d4f98a2 | 3897 | * path->nodes[1]. |
323ac95b CM |
3898 | * |
3899 | * This deletes the pointer in path->nodes[1] and frees the leaf | |
3900 | * block extent. zero is returned if it all worked out, < 0 otherwise. | |
3901 | * | |
3902 | * The path must have already been setup for deleting the leaf, including | |
3903 | * all the proper balancing. path->nodes[1] must be locked. | |
3904 | */ | |
5d4f98a2 YZ |
3905 | static noinline int btrfs_del_leaf(struct btrfs_trans_handle *trans, |
3906 | struct btrfs_root *root, | |
3907 | struct btrfs_path *path, | |
3908 | struct extent_buffer *leaf) | |
323ac95b CM |
3909 | { |
3910 | int ret; | |
323ac95b | 3911 | |
5d4f98a2 | 3912 | WARN_ON(btrfs_header_generation(leaf) != trans->transid); |
323ac95b CM |
3913 | ret = del_ptr(trans, root, path, 1, path->slots[1]); |
3914 | if (ret) | |
3915 | return ret; | |
3916 | ||
4d081c41 CM |
3917 | /* |
3918 | * btrfs_free_extent is expensive, we want to make sure we | |
3919 | * aren't holding any locks when we call it | |
3920 | */ | |
3921 | btrfs_unlock_up_safe(path, 0); | |
3922 | ||
f0486c68 YZ |
3923 | root_sub_used(root, leaf->len); |
3924 | ||
3925 | btrfs_free_tree_block(trans, root, leaf, 0, 1); | |
3926 | return 0; | |
323ac95b | 3927 | } |
74123bd7 CM |
3928 | /* |
3929 | * delete the item at the leaf level in path. If that empties | |
3930 | * the leaf, remove it from the tree | |
3931 | */ | |
85e21bac CM |
3932 | int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
3933 | struct btrfs_path *path, int slot, int nr) | |
be0e5c09 | 3934 | { |
5f39d397 CM |
3935 | struct extent_buffer *leaf; |
3936 | struct btrfs_item *item; | |
85e21bac CM |
3937 | int last_off; |
3938 | int dsize = 0; | |
aa5d6bed CM |
3939 | int ret = 0; |
3940 | int wret; | |
85e21bac | 3941 | int i; |
7518a238 | 3942 | u32 nritems; |
be0e5c09 | 3943 | |
5f39d397 | 3944 | leaf = path->nodes[0]; |
85e21bac CM |
3945 | last_off = btrfs_item_offset_nr(leaf, slot + nr - 1); |
3946 | ||
3947 | for (i = 0; i < nr; i++) | |
3948 | dsize += btrfs_item_size_nr(leaf, slot + i); | |
3949 | ||
5f39d397 | 3950 | nritems = btrfs_header_nritems(leaf); |
be0e5c09 | 3951 | |
85e21bac | 3952 | if (slot + nr != nritems) { |
123abc88 | 3953 | int data_end = leaf_data_end(root, leaf); |
5f39d397 CM |
3954 | |
3955 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + | |
d6025579 CM |
3956 | data_end + dsize, |
3957 | btrfs_leaf_data(leaf) + data_end, | |
85e21bac | 3958 | last_off - data_end); |
5f39d397 | 3959 | |
85e21bac | 3960 | for (i = slot + nr; i < nritems; i++) { |
5f39d397 | 3961 | u32 ioff; |
db94535d | 3962 | |
5f39d397 | 3963 | item = btrfs_item_nr(leaf, i); |
db94535d CM |
3964 | if (!leaf->map_token) { |
3965 | map_extent_buffer(leaf, (unsigned long)item, | |
3966 | sizeof(struct btrfs_item), | |
3967 | &leaf->map_token, &leaf->kaddr, | |
3968 | &leaf->map_start, &leaf->map_len, | |
3969 | KM_USER1); | |
3970 | } | |
5f39d397 CM |
3971 | ioff = btrfs_item_offset(leaf, item); |
3972 | btrfs_set_item_offset(leaf, item, ioff + dsize); | |
0783fcfc | 3973 | } |
db94535d CM |
3974 | |
3975 | if (leaf->map_token) { | |
3976 | unmap_extent_buffer(leaf, leaf->map_token, KM_USER1); | |
3977 | leaf->map_token = NULL; | |
3978 | } | |
3979 | ||
5f39d397 | 3980 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot), |
85e21bac | 3981 | btrfs_item_nr_offset(slot + nr), |
d6025579 | 3982 | sizeof(struct btrfs_item) * |
85e21bac | 3983 | (nritems - slot - nr)); |
be0e5c09 | 3984 | } |
85e21bac CM |
3985 | btrfs_set_header_nritems(leaf, nritems - nr); |
3986 | nritems -= nr; | |
5f39d397 | 3987 | |
74123bd7 | 3988 | /* delete the leaf if we've emptied it */ |
7518a238 | 3989 | if (nritems == 0) { |
5f39d397 CM |
3990 | if (leaf == root->node) { |
3991 | btrfs_set_header_level(leaf, 0); | |
9a8dd150 | 3992 | } else { |
f0486c68 YZ |
3993 | btrfs_set_path_blocking(path); |
3994 | clean_tree_block(trans, root, leaf); | |
5d4f98a2 | 3995 | ret = btrfs_del_leaf(trans, root, path, leaf); |
323ac95b | 3996 | BUG_ON(ret); |
9a8dd150 | 3997 | } |
be0e5c09 | 3998 | } else { |
7518a238 | 3999 | int used = leaf_space_used(leaf, 0, nritems); |
aa5d6bed | 4000 | if (slot == 0) { |
5f39d397 CM |
4001 | struct btrfs_disk_key disk_key; |
4002 | ||
4003 | btrfs_item_key(leaf, &disk_key, 0); | |
e089f05c | 4004 | wret = fixup_low_keys(trans, root, path, |
5f39d397 | 4005 | &disk_key, 1); |
aa5d6bed CM |
4006 | if (wret) |
4007 | ret = wret; | |
4008 | } | |
aa5d6bed | 4009 | |
74123bd7 | 4010 | /* delete the leaf if it is mostly empty */ |
d717aa1d | 4011 | if (used < BTRFS_LEAF_DATA_SIZE(root) / 3) { |
be0e5c09 CM |
4012 | /* push_leaf_left fixes the path. |
4013 | * make sure the path still points to our leaf | |
4014 | * for possible call to del_ptr below | |
4015 | */ | |
4920c9ac | 4016 | slot = path->slots[1]; |
5f39d397 CM |
4017 | extent_buffer_get(leaf); |
4018 | ||
b9473439 | 4019 | btrfs_set_path_blocking(path); |
99d8f83c CM |
4020 | wret = push_leaf_left(trans, root, path, 1, 1, |
4021 | 1, (u32)-1); | |
54aa1f4d | 4022 | if (wret < 0 && wret != -ENOSPC) |
aa5d6bed | 4023 | ret = wret; |
5f39d397 CM |
4024 | |
4025 | if (path->nodes[0] == leaf && | |
4026 | btrfs_header_nritems(leaf)) { | |
99d8f83c CM |
4027 | wret = push_leaf_right(trans, root, path, 1, |
4028 | 1, 1, 0); | |
54aa1f4d | 4029 | if (wret < 0 && wret != -ENOSPC) |
aa5d6bed CM |
4030 | ret = wret; |
4031 | } | |
5f39d397 CM |
4032 | |
4033 | if (btrfs_header_nritems(leaf) == 0) { | |
323ac95b | 4034 | path->slots[1] = slot; |
5d4f98a2 | 4035 | ret = btrfs_del_leaf(trans, root, path, leaf); |
323ac95b | 4036 | BUG_ON(ret); |
5f39d397 | 4037 | free_extent_buffer(leaf); |
5de08d7d | 4038 | } else { |
925baedd CM |
4039 | /* if we're still in the path, make sure |
4040 | * we're dirty. Otherwise, one of the | |
4041 | * push_leaf functions must have already | |
4042 | * dirtied this buffer | |
4043 | */ | |
4044 | if (path->nodes[0] == leaf) | |
4045 | btrfs_mark_buffer_dirty(leaf); | |
5f39d397 | 4046 | free_extent_buffer(leaf); |
be0e5c09 | 4047 | } |
d5719762 | 4048 | } else { |
5f39d397 | 4049 | btrfs_mark_buffer_dirty(leaf); |
be0e5c09 CM |
4050 | } |
4051 | } | |
aa5d6bed | 4052 | return ret; |
be0e5c09 CM |
4053 | } |
4054 | ||
7bb86316 | 4055 | /* |
925baedd | 4056 | * search the tree again to find a leaf with lesser keys |
7bb86316 CM |
4057 | * returns 0 if it found something or 1 if there are no lesser leaves. |
4058 | * returns < 0 on io errors. | |
d352ac68 CM |
4059 | * |
4060 | * This may release the path, and so you may lose any locks held at the | |
4061 | * time you call it. | |
7bb86316 CM |
4062 | */ |
4063 | int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path) | |
4064 | { | |
925baedd CM |
4065 | struct btrfs_key key; |
4066 | struct btrfs_disk_key found_key; | |
4067 | int ret; | |
7bb86316 | 4068 | |
925baedd | 4069 | btrfs_item_key_to_cpu(path->nodes[0], &key, 0); |
7bb86316 | 4070 | |
925baedd CM |
4071 | if (key.offset > 0) |
4072 | key.offset--; | |
4073 | else if (key.type > 0) | |
4074 | key.type--; | |
4075 | else if (key.objectid > 0) | |
4076 | key.objectid--; | |
4077 | else | |
4078 | return 1; | |
7bb86316 | 4079 | |
925baedd CM |
4080 | btrfs_release_path(root, path); |
4081 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); | |
4082 | if (ret < 0) | |
4083 | return ret; | |
4084 | btrfs_item_key(path->nodes[0], &found_key, 0); | |
4085 | ret = comp_keys(&found_key, &key); | |
4086 | if (ret < 0) | |
4087 | return 0; | |
4088 | return 1; | |
7bb86316 CM |
4089 | } |
4090 | ||
3f157a2f CM |
4091 | /* |
4092 | * A helper function to walk down the tree starting at min_key, and looking | |
4093 | * for nodes or leaves that are either in cache or have a minimum | |
d352ac68 | 4094 | * transaction id. This is used by the btree defrag code, and tree logging |
3f157a2f CM |
4095 | * |
4096 | * This does not cow, but it does stuff the starting key it finds back | |
4097 | * into min_key, so you can call btrfs_search_slot with cow=1 on the | |
4098 | * key and get a writable path. | |
4099 | * | |
4100 | * This does lock as it descends, and path->keep_locks should be set | |
4101 | * to 1 by the caller. | |
4102 | * | |
4103 | * This honors path->lowest_level to prevent descent past a given level | |
4104 | * of the tree. | |
4105 | * | |
d352ac68 CM |
4106 | * min_trans indicates the oldest transaction that you are interested |
4107 | * in walking through. Any nodes or leaves older than min_trans are | |
4108 | * skipped over (without reading them). | |
4109 | * | |
3f157a2f CM |
4110 | * returns zero if something useful was found, < 0 on error and 1 if there |
4111 | * was nothing in the tree that matched the search criteria. | |
4112 | */ | |
4113 | int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key, | |
e02119d5 | 4114 | struct btrfs_key *max_key, |
3f157a2f CM |
4115 | struct btrfs_path *path, int cache_only, |
4116 | u64 min_trans) | |
4117 | { | |
4118 | struct extent_buffer *cur; | |
4119 | struct btrfs_key found_key; | |
4120 | int slot; | |
9652480b | 4121 | int sret; |
3f157a2f CM |
4122 | u32 nritems; |
4123 | int level; | |
4124 | int ret = 1; | |
4125 | ||
934d375b | 4126 | WARN_ON(!path->keep_locks); |
3f157a2f CM |
4127 | again: |
4128 | cur = btrfs_lock_root_node(root); | |
4129 | level = btrfs_header_level(cur); | |
e02119d5 | 4130 | WARN_ON(path->nodes[level]); |
3f157a2f CM |
4131 | path->nodes[level] = cur; |
4132 | path->locks[level] = 1; | |
4133 | ||
4134 | if (btrfs_header_generation(cur) < min_trans) { | |
4135 | ret = 1; | |
4136 | goto out; | |
4137 | } | |
d397712b | 4138 | while (1) { |
3f157a2f CM |
4139 | nritems = btrfs_header_nritems(cur); |
4140 | level = btrfs_header_level(cur); | |
9652480b | 4141 | sret = bin_search(cur, min_key, level, &slot); |
3f157a2f | 4142 | |
323ac95b CM |
4143 | /* at the lowest level, we're done, setup the path and exit */ |
4144 | if (level == path->lowest_level) { | |
e02119d5 CM |
4145 | if (slot >= nritems) |
4146 | goto find_next_key; | |
3f157a2f CM |
4147 | ret = 0; |
4148 | path->slots[level] = slot; | |
4149 | btrfs_item_key_to_cpu(cur, &found_key, slot); | |
4150 | goto out; | |
4151 | } | |
9652480b Y |
4152 | if (sret && slot > 0) |
4153 | slot--; | |
3f157a2f CM |
4154 | /* |
4155 | * check this node pointer against the cache_only and | |
4156 | * min_trans parameters. If it isn't in cache or is too | |
4157 | * old, skip to the next one. | |
4158 | */ | |
d397712b | 4159 | while (slot < nritems) { |
3f157a2f CM |
4160 | u64 blockptr; |
4161 | u64 gen; | |
4162 | struct extent_buffer *tmp; | |
e02119d5 CM |
4163 | struct btrfs_disk_key disk_key; |
4164 | ||
3f157a2f CM |
4165 | blockptr = btrfs_node_blockptr(cur, slot); |
4166 | gen = btrfs_node_ptr_generation(cur, slot); | |
4167 | if (gen < min_trans) { | |
4168 | slot++; | |
4169 | continue; | |
4170 | } | |
4171 | if (!cache_only) | |
4172 | break; | |
4173 | ||
e02119d5 CM |
4174 | if (max_key) { |
4175 | btrfs_node_key(cur, &disk_key, slot); | |
4176 | if (comp_keys(&disk_key, max_key) >= 0) { | |
4177 | ret = 1; | |
4178 | goto out; | |
4179 | } | |
4180 | } | |
4181 | ||
3f157a2f CM |
4182 | tmp = btrfs_find_tree_block(root, blockptr, |
4183 | btrfs_level_size(root, level - 1)); | |
4184 | ||
4185 | if (tmp && btrfs_buffer_uptodate(tmp, gen)) { | |
4186 | free_extent_buffer(tmp); | |
4187 | break; | |
4188 | } | |
4189 | if (tmp) | |
4190 | free_extent_buffer(tmp); | |
4191 | slot++; | |
4192 | } | |
e02119d5 | 4193 | find_next_key: |
3f157a2f CM |
4194 | /* |
4195 | * we didn't find a candidate key in this node, walk forward | |
4196 | * and find another one | |
4197 | */ | |
4198 | if (slot >= nritems) { | |
e02119d5 | 4199 | path->slots[level] = slot; |
b4ce94de | 4200 | btrfs_set_path_blocking(path); |
e02119d5 | 4201 | sret = btrfs_find_next_key(root, path, min_key, level, |
3f157a2f | 4202 | cache_only, min_trans); |
e02119d5 | 4203 | if (sret == 0) { |
3f157a2f CM |
4204 | btrfs_release_path(root, path); |
4205 | goto again; | |
4206 | } else { | |
4207 | goto out; | |
4208 | } | |
4209 | } | |
4210 | /* save our key for returning back */ | |
4211 | btrfs_node_key_to_cpu(cur, &found_key, slot); | |
4212 | path->slots[level] = slot; | |
4213 | if (level == path->lowest_level) { | |
4214 | ret = 0; | |
4215 | unlock_up(path, level, 1); | |
4216 | goto out; | |
4217 | } | |
b4ce94de | 4218 | btrfs_set_path_blocking(path); |
3f157a2f CM |
4219 | cur = read_node_slot(root, cur, slot); |
4220 | ||
4221 | btrfs_tree_lock(cur); | |
b4ce94de | 4222 | |
3f157a2f CM |
4223 | path->locks[level - 1] = 1; |
4224 | path->nodes[level - 1] = cur; | |
4225 | unlock_up(path, level, 1); | |
4008c04a | 4226 | btrfs_clear_path_blocking(path, NULL); |
3f157a2f CM |
4227 | } |
4228 | out: | |
4229 | if (ret == 0) | |
4230 | memcpy(min_key, &found_key, sizeof(found_key)); | |
b4ce94de | 4231 | btrfs_set_path_blocking(path); |
3f157a2f CM |
4232 | return ret; |
4233 | } | |
4234 | ||
4235 | /* | |
4236 | * this is similar to btrfs_next_leaf, but does not try to preserve | |
4237 | * and fixup the path. It looks for and returns the next key in the | |
4238 | * tree based on the current path and the cache_only and min_trans | |
4239 | * parameters. | |
4240 | * | |
4241 | * 0 is returned if another key is found, < 0 if there are any errors | |
4242 | * and 1 is returned if there are no higher keys in the tree | |
4243 | * | |
4244 | * path->keep_locks should be set to 1 on the search made before | |
4245 | * calling this function. | |
4246 | */ | |
e7a84565 | 4247 | int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path, |
33c66f43 | 4248 | struct btrfs_key *key, int level, |
3f157a2f | 4249 | int cache_only, u64 min_trans) |
e7a84565 | 4250 | { |
e7a84565 CM |
4251 | int slot; |
4252 | struct extent_buffer *c; | |
4253 | ||
934d375b | 4254 | WARN_ON(!path->keep_locks); |
d397712b | 4255 | while (level < BTRFS_MAX_LEVEL) { |
e7a84565 CM |
4256 | if (!path->nodes[level]) |
4257 | return 1; | |
4258 | ||
4259 | slot = path->slots[level] + 1; | |
4260 | c = path->nodes[level]; | |
3f157a2f | 4261 | next: |
e7a84565 | 4262 | if (slot >= btrfs_header_nritems(c)) { |
33c66f43 YZ |
4263 | int ret; |
4264 | int orig_lowest; | |
4265 | struct btrfs_key cur_key; | |
4266 | if (level + 1 >= BTRFS_MAX_LEVEL || | |
4267 | !path->nodes[level + 1]) | |
e7a84565 | 4268 | return 1; |
33c66f43 YZ |
4269 | |
4270 | if (path->locks[level + 1]) { | |
4271 | level++; | |
4272 | continue; | |
4273 | } | |
4274 | ||
4275 | slot = btrfs_header_nritems(c) - 1; | |
4276 | if (level == 0) | |
4277 | btrfs_item_key_to_cpu(c, &cur_key, slot); | |
4278 | else | |
4279 | btrfs_node_key_to_cpu(c, &cur_key, slot); | |
4280 | ||
4281 | orig_lowest = path->lowest_level; | |
4282 | btrfs_release_path(root, path); | |
4283 | path->lowest_level = level; | |
4284 | ret = btrfs_search_slot(NULL, root, &cur_key, path, | |
4285 | 0, 0); | |
4286 | path->lowest_level = orig_lowest; | |
4287 | if (ret < 0) | |
4288 | return ret; | |
4289 | ||
4290 | c = path->nodes[level]; | |
4291 | slot = path->slots[level]; | |
4292 | if (ret == 0) | |
4293 | slot++; | |
4294 | goto next; | |
e7a84565 | 4295 | } |
33c66f43 | 4296 | |
e7a84565 CM |
4297 | if (level == 0) |
4298 | btrfs_item_key_to_cpu(c, key, slot); | |
3f157a2f CM |
4299 | else { |
4300 | u64 blockptr = btrfs_node_blockptr(c, slot); | |
4301 | u64 gen = btrfs_node_ptr_generation(c, slot); | |
4302 | ||
4303 | if (cache_only) { | |
4304 | struct extent_buffer *cur; | |
4305 | cur = btrfs_find_tree_block(root, blockptr, | |
4306 | btrfs_level_size(root, level - 1)); | |
4307 | if (!cur || !btrfs_buffer_uptodate(cur, gen)) { | |
4308 | slot++; | |
4309 | if (cur) | |
4310 | free_extent_buffer(cur); | |
4311 | goto next; | |
4312 | } | |
4313 | free_extent_buffer(cur); | |
4314 | } | |
4315 | if (gen < min_trans) { | |
4316 | slot++; | |
4317 | goto next; | |
4318 | } | |
e7a84565 | 4319 | btrfs_node_key_to_cpu(c, key, slot); |
3f157a2f | 4320 | } |
e7a84565 CM |
4321 | return 0; |
4322 | } | |
4323 | return 1; | |
4324 | } | |
4325 | ||
97571fd0 | 4326 | /* |
925baedd | 4327 | * search the tree again to find a leaf with greater keys |
0f70abe2 CM |
4328 | * returns 0 if it found something or 1 if there are no greater leaves. |
4329 | * returns < 0 on io errors. | |
97571fd0 | 4330 | */ |
234b63a0 | 4331 | int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path) |
d97e63b6 CM |
4332 | { |
4333 | int slot; | |
8e73f275 | 4334 | int level; |
5f39d397 | 4335 | struct extent_buffer *c; |
8e73f275 | 4336 | struct extent_buffer *next; |
925baedd CM |
4337 | struct btrfs_key key; |
4338 | u32 nritems; | |
4339 | int ret; | |
8e73f275 CM |
4340 | int old_spinning = path->leave_spinning; |
4341 | int force_blocking = 0; | |
925baedd CM |
4342 | |
4343 | nritems = btrfs_header_nritems(path->nodes[0]); | |
d397712b | 4344 | if (nritems == 0) |
925baedd | 4345 | return 1; |
925baedd | 4346 | |
8e73f275 CM |
4347 | /* |
4348 | * we take the blocks in an order that upsets lockdep. Using | |
4349 | * blocking mode is the only way around it. | |
4350 | */ | |
4351 | #ifdef CONFIG_DEBUG_LOCK_ALLOC | |
4352 | force_blocking = 1; | |
4353 | #endif | |
925baedd | 4354 | |
8e73f275 CM |
4355 | btrfs_item_key_to_cpu(path->nodes[0], &key, nritems - 1); |
4356 | again: | |
4357 | level = 1; | |
4358 | next = NULL; | |
925baedd | 4359 | btrfs_release_path(root, path); |
8e73f275 | 4360 | |
a2135011 | 4361 | path->keep_locks = 1; |
8e73f275 CM |
4362 | |
4363 | if (!force_blocking) | |
4364 | path->leave_spinning = 1; | |
4365 | ||
925baedd CM |
4366 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
4367 | path->keep_locks = 0; | |
4368 | ||
4369 | if (ret < 0) | |
4370 | return ret; | |
4371 | ||
a2135011 | 4372 | nritems = btrfs_header_nritems(path->nodes[0]); |
168fd7d2 CM |
4373 | /* |
4374 | * by releasing the path above we dropped all our locks. A balance | |
4375 | * could have added more items next to the key that used to be | |
4376 | * at the very end of the block. So, check again here and | |
4377 | * advance the path if there are now more items available. | |
4378 | */ | |
a2135011 | 4379 | if (nritems > 0 && path->slots[0] < nritems - 1) { |
e457afec YZ |
4380 | if (ret == 0) |
4381 | path->slots[0]++; | |
8e73f275 | 4382 | ret = 0; |
925baedd CM |
4383 | goto done; |
4384 | } | |
d97e63b6 | 4385 | |
d397712b | 4386 | while (level < BTRFS_MAX_LEVEL) { |
8e73f275 CM |
4387 | if (!path->nodes[level]) { |
4388 | ret = 1; | |
4389 | goto done; | |
4390 | } | |
5f39d397 | 4391 | |
d97e63b6 CM |
4392 | slot = path->slots[level] + 1; |
4393 | c = path->nodes[level]; | |
5f39d397 | 4394 | if (slot >= btrfs_header_nritems(c)) { |
d97e63b6 | 4395 | level++; |
8e73f275 CM |
4396 | if (level == BTRFS_MAX_LEVEL) { |
4397 | ret = 1; | |
4398 | goto done; | |
4399 | } | |
d97e63b6 CM |
4400 | continue; |
4401 | } | |
5f39d397 | 4402 | |
925baedd CM |
4403 | if (next) { |
4404 | btrfs_tree_unlock(next); | |
5f39d397 | 4405 | free_extent_buffer(next); |
925baedd | 4406 | } |
5f39d397 | 4407 | |
8e73f275 CM |
4408 | next = c; |
4409 | ret = read_block_for_search(NULL, root, path, &next, level, | |
4410 | slot, &key); | |
4411 | if (ret == -EAGAIN) | |
4412 | goto again; | |
5f39d397 | 4413 | |
76a05b35 CM |
4414 | if (ret < 0) { |
4415 | btrfs_release_path(root, path); | |
4416 | goto done; | |
4417 | } | |
4418 | ||
5cd57b2c | 4419 | if (!path->skip_locking) { |
8e73f275 CM |
4420 | ret = btrfs_try_spin_lock(next); |
4421 | if (!ret) { | |
4422 | btrfs_set_path_blocking(path); | |
4423 | btrfs_tree_lock(next); | |
4424 | if (!force_blocking) | |
4425 | btrfs_clear_path_blocking(path, next); | |
4426 | } | |
4427 | if (force_blocking) | |
4428 | btrfs_set_lock_blocking(next); | |
5cd57b2c | 4429 | } |
d97e63b6 CM |
4430 | break; |
4431 | } | |
4432 | path->slots[level] = slot; | |
d397712b | 4433 | while (1) { |
d97e63b6 CM |
4434 | level--; |
4435 | c = path->nodes[level]; | |
925baedd CM |
4436 | if (path->locks[level]) |
4437 | btrfs_tree_unlock(c); | |
8e73f275 | 4438 | |
5f39d397 | 4439 | free_extent_buffer(c); |
d97e63b6 CM |
4440 | path->nodes[level] = next; |
4441 | path->slots[level] = 0; | |
a74a4b97 CM |
4442 | if (!path->skip_locking) |
4443 | path->locks[level] = 1; | |
8e73f275 | 4444 | |
d97e63b6 CM |
4445 | if (!level) |
4446 | break; | |
b4ce94de | 4447 | |
8e73f275 CM |
4448 | ret = read_block_for_search(NULL, root, path, &next, level, |
4449 | 0, &key); | |
4450 | if (ret == -EAGAIN) | |
4451 | goto again; | |
4452 | ||
76a05b35 CM |
4453 | if (ret < 0) { |
4454 | btrfs_release_path(root, path); | |
4455 | goto done; | |
4456 | } | |
4457 | ||
5cd57b2c | 4458 | if (!path->skip_locking) { |
b9447ef8 | 4459 | btrfs_assert_tree_locked(path->nodes[level]); |
8e73f275 CM |
4460 | ret = btrfs_try_spin_lock(next); |
4461 | if (!ret) { | |
4462 | btrfs_set_path_blocking(path); | |
4463 | btrfs_tree_lock(next); | |
4464 | if (!force_blocking) | |
4465 | btrfs_clear_path_blocking(path, next); | |
4466 | } | |
4467 | if (force_blocking) | |
4468 | btrfs_set_lock_blocking(next); | |
5cd57b2c | 4469 | } |
d97e63b6 | 4470 | } |
8e73f275 | 4471 | ret = 0; |
925baedd CM |
4472 | done: |
4473 | unlock_up(path, 0, 1); | |
8e73f275 CM |
4474 | path->leave_spinning = old_spinning; |
4475 | if (!old_spinning) | |
4476 | btrfs_set_path_blocking(path); | |
4477 | ||
4478 | return ret; | |
d97e63b6 | 4479 | } |
0b86a832 | 4480 | |
3f157a2f CM |
4481 | /* |
4482 | * this uses btrfs_prev_leaf to walk backwards in the tree, and keeps | |
4483 | * searching until it gets past min_objectid or finds an item of 'type' | |
4484 | * | |
4485 | * returns 0 if something is found, 1 if nothing was found and < 0 on error | |
4486 | */ | |
0b86a832 CM |
4487 | int btrfs_previous_item(struct btrfs_root *root, |
4488 | struct btrfs_path *path, u64 min_objectid, | |
4489 | int type) | |
4490 | { | |
4491 | struct btrfs_key found_key; | |
4492 | struct extent_buffer *leaf; | |
e02119d5 | 4493 | u32 nritems; |
0b86a832 CM |
4494 | int ret; |
4495 | ||
d397712b | 4496 | while (1) { |
0b86a832 | 4497 | if (path->slots[0] == 0) { |
b4ce94de | 4498 | btrfs_set_path_blocking(path); |
0b86a832 CM |
4499 | ret = btrfs_prev_leaf(root, path); |
4500 | if (ret != 0) | |
4501 | return ret; | |
4502 | } else { | |
4503 | path->slots[0]--; | |
4504 | } | |
4505 | leaf = path->nodes[0]; | |
e02119d5 CM |
4506 | nritems = btrfs_header_nritems(leaf); |
4507 | if (nritems == 0) | |
4508 | return 1; | |
4509 | if (path->slots[0] == nritems) | |
4510 | path->slots[0]--; | |
4511 | ||
0b86a832 | 4512 | btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); |
e02119d5 CM |
4513 | if (found_key.objectid < min_objectid) |
4514 | break; | |
0a4eefbb YZ |
4515 | if (found_key.type == type) |
4516 | return 0; | |
e02119d5 CM |
4517 | if (found_key.objectid == min_objectid && |
4518 | found_key.type < type) | |
4519 | break; | |
0b86a832 CM |
4520 | } |
4521 | return 1; | |
4522 | } |