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 | { |
df24a2b9 CM |
108 | btrfs_release_path(NULL, p); |
109 | kmem_cache_free(btrfs_path_cachep, p); | |
be0e5c09 CM |
110 | } |
111 | ||
d352ac68 CM |
112 | /* |
113 | * path release drops references on the extent buffers in the path | |
114 | * and it drops any locks held by this path | |
115 | * | |
116 | * It is safe to call this on paths that no locks or extent buffers held. | |
117 | */ | |
d397712b | 118 | noinline void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p) |
eb60ceac CM |
119 | { |
120 | int i; | |
a2135011 | 121 | |
234b63a0 | 122 | for (i = 0; i < BTRFS_MAX_LEVEL; i++) { |
3f157a2f | 123 | p->slots[i] = 0; |
eb60ceac | 124 | if (!p->nodes[i]) |
925baedd CM |
125 | continue; |
126 | if (p->locks[i]) { | |
127 | btrfs_tree_unlock(p->nodes[i]); | |
128 | p->locks[i] = 0; | |
129 | } | |
5f39d397 | 130 | free_extent_buffer(p->nodes[i]); |
3f157a2f | 131 | p->nodes[i] = NULL; |
eb60ceac CM |
132 | } |
133 | } | |
134 | ||
d352ac68 CM |
135 | /* |
136 | * safely gets a reference on the root node of a tree. A lock | |
137 | * is not taken, so a concurrent writer may put a different node | |
138 | * at the root of the tree. See btrfs_lock_root_node for the | |
139 | * looping required. | |
140 | * | |
141 | * The extent buffer returned by this has a reference taken, so | |
142 | * it won't disappear. It may stop being the root of the tree | |
143 | * at any time because there are no locks held. | |
144 | */ | |
925baedd CM |
145 | struct extent_buffer *btrfs_root_node(struct btrfs_root *root) |
146 | { | |
147 | struct extent_buffer *eb; | |
148 | spin_lock(&root->node_lock); | |
149 | eb = root->node; | |
150 | extent_buffer_get(eb); | |
151 | spin_unlock(&root->node_lock); | |
152 | return eb; | |
153 | } | |
154 | ||
d352ac68 CM |
155 | /* loop around taking references on and locking the root node of the |
156 | * tree until you end up with a lock on the root. A locked buffer | |
157 | * is returned, with a reference held. | |
158 | */ | |
925baedd CM |
159 | struct extent_buffer *btrfs_lock_root_node(struct btrfs_root *root) |
160 | { | |
161 | struct extent_buffer *eb; | |
162 | ||
d397712b | 163 | while (1) { |
925baedd CM |
164 | eb = btrfs_root_node(root); |
165 | btrfs_tree_lock(eb); | |
166 | ||
167 | spin_lock(&root->node_lock); | |
168 | if (eb == root->node) { | |
169 | spin_unlock(&root->node_lock); | |
170 | break; | |
171 | } | |
172 | spin_unlock(&root->node_lock); | |
173 | ||
174 | btrfs_tree_unlock(eb); | |
175 | free_extent_buffer(eb); | |
176 | } | |
177 | return eb; | |
178 | } | |
179 | ||
d352ac68 CM |
180 | /* cowonly root (everything not a reference counted cow subvolume), just get |
181 | * put onto a simple dirty list. transaction.c walks this to make sure they | |
182 | * get properly updated on disk. | |
183 | */ | |
0b86a832 CM |
184 | static void add_root_to_dirty_list(struct btrfs_root *root) |
185 | { | |
186 | if (root->track_dirty && list_empty(&root->dirty_list)) { | |
187 | list_add(&root->dirty_list, | |
188 | &root->fs_info->dirty_cowonly_roots); | |
189 | } | |
190 | } | |
191 | ||
d352ac68 CM |
192 | /* |
193 | * used by snapshot creation to make a copy of a root for a tree with | |
194 | * a given objectid. The buffer with the new root node is returned in | |
195 | * cow_ret, and this func returns zero on success or a negative error code. | |
196 | */ | |
be20aa9d CM |
197 | int btrfs_copy_root(struct btrfs_trans_handle *trans, |
198 | struct btrfs_root *root, | |
199 | struct extent_buffer *buf, | |
200 | struct extent_buffer **cow_ret, u64 new_root_objectid) | |
201 | { | |
202 | struct extent_buffer *cow; | |
203 | u32 nritems; | |
204 | int ret = 0; | |
205 | int level; | |
5d4f98a2 | 206 | struct btrfs_disk_key disk_key; |
be20aa9d CM |
207 | |
208 | WARN_ON(root->ref_cows && trans->transid != | |
209 | root->fs_info->running_transaction->transid); | |
210 | WARN_ON(root->ref_cows && trans->transid != root->last_trans); | |
211 | ||
212 | level = btrfs_header_level(buf); | |
213 | nritems = btrfs_header_nritems(buf); | |
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 | |
02217ed2 | 450 | if (buf == root->node) { |
925baedd | 451 | WARN_ON(parent && parent != buf); |
5d4f98a2 YZ |
452 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID || |
453 | btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) | |
454 | parent_start = buf->start; | |
455 | else | |
456 | parent_start = 0; | |
925baedd CM |
457 | |
458 | spin_lock(&root->node_lock); | |
02217ed2 | 459 | root->node = cow; |
5f39d397 | 460 | extent_buffer_get(cow); |
925baedd CM |
461 | spin_unlock(&root->node_lock); |
462 | ||
f0486c68 YZ |
463 | btrfs_free_tree_block(trans, root, buf, parent_start, |
464 | last_ref); | |
5f39d397 | 465 | free_extent_buffer(buf); |
0b86a832 | 466 | add_root_to_dirty_list(root); |
02217ed2 | 467 | } else { |
5d4f98a2 YZ |
468 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) |
469 | parent_start = parent->start; | |
470 | else | |
471 | parent_start = 0; | |
472 | ||
473 | WARN_ON(trans->transid != btrfs_header_generation(parent)); | |
5f39d397 | 474 | btrfs_set_node_blockptr(parent, parent_slot, |
db94535d | 475 | cow->start); |
74493f7a CM |
476 | btrfs_set_node_ptr_generation(parent, parent_slot, |
477 | trans->transid); | |
d6025579 | 478 | btrfs_mark_buffer_dirty(parent); |
f0486c68 YZ |
479 | btrfs_free_tree_block(trans, root, buf, parent_start, |
480 | last_ref); | |
02217ed2 | 481 | } |
925baedd CM |
482 | if (unlock_orig) |
483 | btrfs_tree_unlock(buf); | |
5f39d397 | 484 | free_extent_buffer(buf); |
ccd467d6 | 485 | btrfs_mark_buffer_dirty(cow); |
2c90e5d6 | 486 | *cow_ret = cow; |
02217ed2 CM |
487 | return 0; |
488 | } | |
489 | ||
5d4f98a2 YZ |
490 | static inline int should_cow_block(struct btrfs_trans_handle *trans, |
491 | struct btrfs_root *root, | |
492 | struct extent_buffer *buf) | |
493 | { | |
494 | if (btrfs_header_generation(buf) == trans->transid && | |
495 | !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN) && | |
496 | !(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID && | |
497 | btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC))) | |
498 | return 0; | |
499 | return 1; | |
500 | } | |
501 | ||
d352ac68 CM |
502 | /* |
503 | * cows a single block, see __btrfs_cow_block for the real work. | |
504 | * This version of it has extra checks so that a block isn't cow'd more than | |
505 | * once per transaction, as long as it hasn't been written yet | |
506 | */ | |
d397712b | 507 | noinline int btrfs_cow_block(struct btrfs_trans_handle *trans, |
5f39d397 CM |
508 | struct btrfs_root *root, struct extent_buffer *buf, |
509 | struct extent_buffer *parent, int parent_slot, | |
9fa8cfe7 | 510 | struct extent_buffer **cow_ret) |
6702ed49 CM |
511 | { |
512 | u64 search_start; | |
f510cfec | 513 | int ret; |
dc17ff8f | 514 | |
6702ed49 | 515 | if (trans->transaction != root->fs_info->running_transaction) { |
d397712b CM |
516 | printk(KERN_CRIT "trans %llu running %llu\n", |
517 | (unsigned long long)trans->transid, | |
518 | (unsigned long long) | |
6702ed49 CM |
519 | root->fs_info->running_transaction->transid); |
520 | WARN_ON(1); | |
521 | } | |
522 | if (trans->transid != root->fs_info->generation) { | |
d397712b CM |
523 | printk(KERN_CRIT "trans %llu running %llu\n", |
524 | (unsigned long long)trans->transid, | |
525 | (unsigned long long)root->fs_info->generation); | |
6702ed49 CM |
526 | WARN_ON(1); |
527 | } | |
dc17ff8f | 528 | |
5d4f98a2 | 529 | if (!should_cow_block(trans, root, buf)) { |
6702ed49 CM |
530 | *cow_ret = buf; |
531 | return 0; | |
532 | } | |
c487685d | 533 | |
0b86a832 | 534 | search_start = buf->start & ~((u64)(1024 * 1024 * 1024) - 1); |
b4ce94de CM |
535 | |
536 | if (parent) | |
537 | btrfs_set_lock_blocking(parent); | |
538 | btrfs_set_lock_blocking(buf); | |
539 | ||
f510cfec | 540 | ret = __btrfs_cow_block(trans, root, buf, parent, |
9fa8cfe7 | 541 | parent_slot, cow_ret, search_start, 0); |
f510cfec | 542 | return ret; |
6702ed49 CM |
543 | } |
544 | ||
d352ac68 CM |
545 | /* |
546 | * helper function for defrag to decide if two blocks pointed to by a | |
547 | * node are actually close by | |
548 | */ | |
6b80053d | 549 | static int close_blocks(u64 blocknr, u64 other, u32 blocksize) |
6702ed49 | 550 | { |
6b80053d | 551 | if (blocknr < other && other - (blocknr + blocksize) < 32768) |
6702ed49 | 552 | return 1; |
6b80053d | 553 | if (blocknr > other && blocknr - (other + blocksize) < 32768) |
6702ed49 CM |
554 | return 1; |
555 | return 0; | |
556 | } | |
557 | ||
081e9573 CM |
558 | /* |
559 | * compare two keys in a memcmp fashion | |
560 | */ | |
561 | static int comp_keys(struct btrfs_disk_key *disk, struct btrfs_key *k2) | |
562 | { | |
563 | struct btrfs_key k1; | |
564 | ||
565 | btrfs_disk_key_to_cpu(&k1, disk); | |
566 | ||
20736aba | 567 | return btrfs_comp_cpu_keys(&k1, k2); |
081e9573 CM |
568 | } |
569 | ||
f3465ca4 JB |
570 | /* |
571 | * same as comp_keys only with two btrfs_key's | |
572 | */ | |
5d4f98a2 | 573 | int btrfs_comp_cpu_keys(struct btrfs_key *k1, struct btrfs_key *k2) |
f3465ca4 JB |
574 | { |
575 | if (k1->objectid > k2->objectid) | |
576 | return 1; | |
577 | if (k1->objectid < k2->objectid) | |
578 | return -1; | |
579 | if (k1->type > k2->type) | |
580 | return 1; | |
581 | if (k1->type < k2->type) | |
582 | return -1; | |
583 | if (k1->offset > k2->offset) | |
584 | return 1; | |
585 | if (k1->offset < k2->offset) | |
586 | return -1; | |
587 | return 0; | |
588 | } | |
081e9573 | 589 | |
d352ac68 CM |
590 | /* |
591 | * this is used by the defrag code to go through all the | |
592 | * leaves pointed to by a node and reallocate them so that | |
593 | * disk order is close to key order | |
594 | */ | |
6702ed49 | 595 | int btrfs_realloc_node(struct btrfs_trans_handle *trans, |
5f39d397 | 596 | struct btrfs_root *root, struct extent_buffer *parent, |
a6b6e75e CM |
597 | int start_slot, int cache_only, u64 *last_ret, |
598 | struct btrfs_key *progress) | |
6702ed49 | 599 | { |
6b80053d | 600 | struct extent_buffer *cur; |
6702ed49 | 601 | u64 blocknr; |
ca7a79ad | 602 | u64 gen; |
e9d0b13b CM |
603 | u64 search_start = *last_ret; |
604 | u64 last_block = 0; | |
6702ed49 CM |
605 | u64 other; |
606 | u32 parent_nritems; | |
6702ed49 CM |
607 | int end_slot; |
608 | int i; | |
609 | int err = 0; | |
f2183bde | 610 | int parent_level; |
6b80053d CM |
611 | int uptodate; |
612 | u32 blocksize; | |
081e9573 CM |
613 | int progress_passed = 0; |
614 | struct btrfs_disk_key disk_key; | |
6702ed49 | 615 | |
5708b959 CM |
616 | parent_level = btrfs_header_level(parent); |
617 | if (cache_only && parent_level != 1) | |
618 | return 0; | |
619 | ||
d397712b | 620 | if (trans->transaction != root->fs_info->running_transaction) |
6702ed49 | 621 | WARN_ON(1); |
d397712b | 622 | if (trans->transid != root->fs_info->generation) |
6702ed49 | 623 | WARN_ON(1); |
86479a04 | 624 | |
6b80053d | 625 | parent_nritems = btrfs_header_nritems(parent); |
6b80053d | 626 | blocksize = btrfs_level_size(root, parent_level - 1); |
6702ed49 CM |
627 | end_slot = parent_nritems; |
628 | ||
629 | if (parent_nritems == 1) | |
630 | return 0; | |
631 | ||
b4ce94de CM |
632 | btrfs_set_lock_blocking(parent); |
633 | ||
6702ed49 CM |
634 | for (i = start_slot; i < end_slot; i++) { |
635 | int close = 1; | |
a6b6e75e | 636 | |
5708b959 CM |
637 | if (!parent->map_token) { |
638 | map_extent_buffer(parent, | |
639 | btrfs_node_key_ptr_offset(i), | |
640 | sizeof(struct btrfs_key_ptr), | |
641 | &parent->map_token, &parent->kaddr, | |
642 | &parent->map_start, &parent->map_len, | |
643 | KM_USER1); | |
644 | } | |
081e9573 CM |
645 | btrfs_node_key(parent, &disk_key, i); |
646 | if (!progress_passed && comp_keys(&disk_key, progress) < 0) | |
647 | continue; | |
648 | ||
649 | progress_passed = 1; | |
6b80053d | 650 | blocknr = btrfs_node_blockptr(parent, i); |
ca7a79ad | 651 | gen = btrfs_node_ptr_generation(parent, i); |
e9d0b13b CM |
652 | if (last_block == 0) |
653 | last_block = blocknr; | |
5708b959 | 654 | |
6702ed49 | 655 | if (i > 0) { |
6b80053d CM |
656 | other = btrfs_node_blockptr(parent, i - 1); |
657 | close = close_blocks(blocknr, other, blocksize); | |
6702ed49 | 658 | } |
0ef3e66b | 659 | if (!close && i < end_slot - 2) { |
6b80053d CM |
660 | other = btrfs_node_blockptr(parent, i + 1); |
661 | close = close_blocks(blocknr, other, blocksize); | |
6702ed49 | 662 | } |
e9d0b13b CM |
663 | if (close) { |
664 | last_block = blocknr; | |
6702ed49 | 665 | continue; |
e9d0b13b | 666 | } |
5708b959 CM |
667 | if (parent->map_token) { |
668 | unmap_extent_buffer(parent, parent->map_token, | |
669 | KM_USER1); | |
670 | parent->map_token = NULL; | |
671 | } | |
6702ed49 | 672 | |
6b80053d CM |
673 | cur = btrfs_find_tree_block(root, blocknr, blocksize); |
674 | if (cur) | |
1259ab75 | 675 | uptodate = btrfs_buffer_uptodate(cur, gen); |
6b80053d CM |
676 | else |
677 | uptodate = 0; | |
5708b959 | 678 | if (!cur || !uptodate) { |
6702ed49 | 679 | if (cache_only) { |
6b80053d | 680 | free_extent_buffer(cur); |
6702ed49 CM |
681 | continue; |
682 | } | |
6b80053d CM |
683 | if (!cur) { |
684 | cur = read_tree_block(root, blocknr, | |
ca7a79ad | 685 | blocksize, gen); |
6b80053d | 686 | } else if (!uptodate) { |
ca7a79ad | 687 | btrfs_read_buffer(cur, gen); |
f2183bde | 688 | } |
6702ed49 | 689 | } |
e9d0b13b | 690 | if (search_start == 0) |
6b80053d | 691 | search_start = last_block; |
e9d0b13b | 692 | |
e7a84565 | 693 | btrfs_tree_lock(cur); |
b4ce94de | 694 | btrfs_set_lock_blocking(cur); |
6b80053d | 695 | err = __btrfs_cow_block(trans, root, cur, parent, i, |
e7a84565 | 696 | &cur, search_start, |
6b80053d | 697 | min(16 * blocksize, |
9fa8cfe7 | 698 | (end_slot - i) * blocksize)); |
252c38f0 | 699 | if (err) { |
e7a84565 | 700 | btrfs_tree_unlock(cur); |
6b80053d | 701 | free_extent_buffer(cur); |
6702ed49 | 702 | break; |
252c38f0 | 703 | } |
e7a84565 CM |
704 | search_start = cur->start; |
705 | last_block = cur->start; | |
f2183bde | 706 | *last_ret = search_start; |
e7a84565 CM |
707 | btrfs_tree_unlock(cur); |
708 | free_extent_buffer(cur); | |
6702ed49 | 709 | } |
5708b959 CM |
710 | if (parent->map_token) { |
711 | unmap_extent_buffer(parent, parent->map_token, | |
712 | KM_USER1); | |
713 | parent->map_token = NULL; | |
714 | } | |
6702ed49 CM |
715 | return err; |
716 | } | |
717 | ||
74123bd7 CM |
718 | /* |
719 | * The leaf data grows from end-to-front in the node. | |
720 | * this returns the address of the start of the last item, | |
721 | * which is the stop of the leaf data stack | |
722 | */ | |
123abc88 | 723 | static inline unsigned int leaf_data_end(struct btrfs_root *root, |
5f39d397 | 724 | struct extent_buffer *leaf) |
be0e5c09 | 725 | { |
5f39d397 | 726 | u32 nr = btrfs_header_nritems(leaf); |
be0e5c09 | 727 | if (nr == 0) |
123abc88 | 728 | return BTRFS_LEAF_DATA_SIZE(root); |
5f39d397 | 729 | return btrfs_item_offset_nr(leaf, nr - 1); |
be0e5c09 CM |
730 | } |
731 | ||
d352ac68 CM |
732 | /* |
733 | * extra debugging checks to make sure all the items in a key are | |
734 | * well formed and in the proper order | |
735 | */ | |
123abc88 CM |
736 | static int check_node(struct btrfs_root *root, struct btrfs_path *path, |
737 | int level) | |
aa5d6bed | 738 | { |
5f39d397 CM |
739 | struct extent_buffer *parent = NULL; |
740 | struct extent_buffer *node = path->nodes[level]; | |
741 | struct btrfs_disk_key parent_key; | |
742 | struct btrfs_disk_key node_key; | |
aa5d6bed | 743 | int parent_slot; |
8d7be552 CM |
744 | int slot; |
745 | struct btrfs_key cpukey; | |
5f39d397 | 746 | u32 nritems = btrfs_header_nritems(node); |
aa5d6bed CM |
747 | |
748 | if (path->nodes[level + 1]) | |
5f39d397 | 749 | parent = path->nodes[level + 1]; |
a1f39630 | 750 | |
8d7be552 | 751 | slot = path->slots[level]; |
7518a238 CM |
752 | BUG_ON(nritems == 0); |
753 | if (parent) { | |
a1f39630 | 754 | parent_slot = path->slots[level + 1]; |
5f39d397 CM |
755 | btrfs_node_key(parent, &parent_key, parent_slot); |
756 | btrfs_node_key(node, &node_key, 0); | |
757 | BUG_ON(memcmp(&parent_key, &node_key, | |
e2fa7227 | 758 | sizeof(struct btrfs_disk_key))); |
1d4f8a0c | 759 | BUG_ON(btrfs_node_blockptr(parent, parent_slot) != |
db94535d | 760 | btrfs_header_bytenr(node)); |
aa5d6bed | 761 | } |
123abc88 | 762 | BUG_ON(nritems > BTRFS_NODEPTRS_PER_BLOCK(root)); |
8d7be552 | 763 | if (slot != 0) { |
5f39d397 CM |
764 | btrfs_node_key_to_cpu(node, &cpukey, slot - 1); |
765 | btrfs_node_key(node, &node_key, slot); | |
766 | BUG_ON(comp_keys(&node_key, &cpukey) <= 0); | |
8d7be552 CM |
767 | } |
768 | if (slot < nritems - 1) { | |
5f39d397 CM |
769 | btrfs_node_key_to_cpu(node, &cpukey, slot + 1); |
770 | btrfs_node_key(node, &node_key, slot); | |
771 | BUG_ON(comp_keys(&node_key, &cpukey) >= 0); | |
aa5d6bed CM |
772 | } |
773 | return 0; | |
774 | } | |
775 | ||
d352ac68 CM |
776 | /* |
777 | * extra checking to make sure all the items in a leaf are | |
778 | * well formed and in the proper order | |
779 | */ | |
123abc88 CM |
780 | static int check_leaf(struct btrfs_root *root, struct btrfs_path *path, |
781 | int level) | |
aa5d6bed | 782 | { |
5f39d397 CM |
783 | struct extent_buffer *leaf = path->nodes[level]; |
784 | struct extent_buffer *parent = NULL; | |
aa5d6bed | 785 | int parent_slot; |
8d7be552 | 786 | struct btrfs_key cpukey; |
5f39d397 CM |
787 | struct btrfs_disk_key parent_key; |
788 | struct btrfs_disk_key leaf_key; | |
789 | int slot = path->slots[0]; | |
8d7be552 | 790 | |
5f39d397 | 791 | u32 nritems = btrfs_header_nritems(leaf); |
aa5d6bed CM |
792 | |
793 | if (path->nodes[level + 1]) | |
5f39d397 | 794 | parent = path->nodes[level + 1]; |
7518a238 CM |
795 | |
796 | if (nritems == 0) | |
797 | return 0; | |
798 | ||
799 | if (parent) { | |
a1f39630 | 800 | parent_slot = path->slots[level + 1]; |
5f39d397 CM |
801 | btrfs_node_key(parent, &parent_key, parent_slot); |
802 | btrfs_item_key(leaf, &leaf_key, 0); | |
6702ed49 | 803 | |
5f39d397 | 804 | BUG_ON(memcmp(&parent_key, &leaf_key, |
e2fa7227 | 805 | sizeof(struct btrfs_disk_key))); |
1d4f8a0c | 806 | BUG_ON(btrfs_node_blockptr(parent, parent_slot) != |
db94535d | 807 | btrfs_header_bytenr(leaf)); |
5f39d397 | 808 | } |
5f39d397 CM |
809 | if (slot != 0 && slot < nritems - 1) { |
810 | btrfs_item_key(leaf, &leaf_key, slot); | |
811 | btrfs_item_key_to_cpu(leaf, &cpukey, slot - 1); | |
812 | if (comp_keys(&leaf_key, &cpukey) <= 0) { | |
813 | btrfs_print_leaf(root, leaf); | |
d397712b | 814 | printk(KERN_CRIT "slot %d offset bad key\n", slot); |
5f39d397 CM |
815 | BUG_ON(1); |
816 | } | |
817 | if (btrfs_item_offset_nr(leaf, slot - 1) != | |
818 | btrfs_item_end_nr(leaf, slot)) { | |
819 | btrfs_print_leaf(root, leaf); | |
d397712b | 820 | printk(KERN_CRIT "slot %d offset bad\n", slot); |
5f39d397 CM |
821 | BUG_ON(1); |
822 | } | |
8d7be552 CM |
823 | } |
824 | if (slot < nritems - 1) { | |
5f39d397 CM |
825 | btrfs_item_key(leaf, &leaf_key, slot); |
826 | btrfs_item_key_to_cpu(leaf, &cpukey, slot + 1); | |
827 | BUG_ON(comp_keys(&leaf_key, &cpukey) >= 0); | |
828 | if (btrfs_item_offset_nr(leaf, slot) != | |
829 | btrfs_item_end_nr(leaf, slot + 1)) { | |
830 | btrfs_print_leaf(root, leaf); | |
d397712b | 831 | printk(KERN_CRIT "slot %d offset bad\n", slot); |
5f39d397 CM |
832 | BUG_ON(1); |
833 | } | |
aa5d6bed | 834 | } |
5f39d397 CM |
835 | BUG_ON(btrfs_item_offset_nr(leaf, 0) + |
836 | btrfs_item_size_nr(leaf, 0) != BTRFS_LEAF_DATA_SIZE(root)); | |
aa5d6bed CM |
837 | return 0; |
838 | } | |
839 | ||
d397712b | 840 | static noinline int check_block(struct btrfs_root *root, |
98ed5174 | 841 | struct btrfs_path *path, int level) |
aa5d6bed | 842 | { |
85d824c4 | 843 | return 0; |
aa5d6bed | 844 | if (level == 0) |
123abc88 CM |
845 | return check_leaf(root, path, level); |
846 | return check_node(root, path, level); | |
aa5d6bed CM |
847 | } |
848 | ||
74123bd7 | 849 | /* |
5f39d397 CM |
850 | * search for key in the extent_buffer. The items start at offset p, |
851 | * and they are item_size apart. There are 'max' items in p. | |
852 | * | |
74123bd7 CM |
853 | * the slot in the array is returned via slot, and it points to |
854 | * the place where you would insert key if it is not found in | |
855 | * the array. | |
856 | * | |
857 | * slot may point to max if the key is bigger than all of the keys | |
858 | */ | |
e02119d5 CM |
859 | static noinline int generic_bin_search(struct extent_buffer *eb, |
860 | unsigned long p, | |
861 | int item_size, struct btrfs_key *key, | |
862 | int max, int *slot) | |
be0e5c09 CM |
863 | { |
864 | int low = 0; | |
865 | int high = max; | |
866 | int mid; | |
867 | int ret; | |
479965d6 | 868 | struct btrfs_disk_key *tmp = NULL; |
5f39d397 CM |
869 | struct btrfs_disk_key unaligned; |
870 | unsigned long offset; | |
871 | char *map_token = NULL; | |
872 | char *kaddr = NULL; | |
873 | unsigned long map_start = 0; | |
874 | unsigned long map_len = 0; | |
479965d6 | 875 | int err; |
be0e5c09 | 876 | |
d397712b | 877 | while (low < high) { |
be0e5c09 | 878 | mid = (low + high) / 2; |
5f39d397 CM |
879 | offset = p + mid * item_size; |
880 | ||
881 | if (!map_token || offset < map_start || | |
882 | (offset + sizeof(struct btrfs_disk_key)) > | |
883 | map_start + map_len) { | |
479965d6 | 884 | if (map_token) { |
5f39d397 | 885 | unmap_extent_buffer(eb, map_token, KM_USER0); |
479965d6 CM |
886 | map_token = NULL; |
887 | } | |
934d375b CM |
888 | |
889 | err = map_private_extent_buffer(eb, offset, | |
479965d6 CM |
890 | sizeof(struct btrfs_disk_key), |
891 | &map_token, &kaddr, | |
892 | &map_start, &map_len, KM_USER0); | |
893 | ||
894 | if (!err) { | |
895 | tmp = (struct btrfs_disk_key *)(kaddr + offset - | |
896 | map_start); | |
897 | } else { | |
898 | read_extent_buffer(eb, &unaligned, | |
899 | offset, sizeof(unaligned)); | |
900 | tmp = &unaligned; | |
901 | } | |
5f39d397 | 902 | |
5f39d397 CM |
903 | } else { |
904 | tmp = (struct btrfs_disk_key *)(kaddr + offset - | |
905 | map_start); | |
906 | } | |
be0e5c09 CM |
907 | ret = comp_keys(tmp, key); |
908 | ||
909 | if (ret < 0) | |
910 | low = mid + 1; | |
911 | else if (ret > 0) | |
912 | high = mid; | |
913 | else { | |
914 | *slot = mid; | |
479965d6 CM |
915 | if (map_token) |
916 | unmap_extent_buffer(eb, map_token, KM_USER0); | |
be0e5c09 CM |
917 | return 0; |
918 | } | |
919 | } | |
920 | *slot = low; | |
5f39d397 CM |
921 | if (map_token) |
922 | unmap_extent_buffer(eb, map_token, KM_USER0); | |
be0e5c09 CM |
923 | return 1; |
924 | } | |
925 | ||
97571fd0 CM |
926 | /* |
927 | * simple bin_search frontend that does the right thing for | |
928 | * leaves vs nodes | |
929 | */ | |
5f39d397 CM |
930 | static int bin_search(struct extent_buffer *eb, struct btrfs_key *key, |
931 | int level, int *slot) | |
be0e5c09 | 932 | { |
5f39d397 CM |
933 | if (level == 0) { |
934 | return generic_bin_search(eb, | |
935 | offsetof(struct btrfs_leaf, items), | |
0783fcfc | 936 | sizeof(struct btrfs_item), |
5f39d397 | 937 | key, btrfs_header_nritems(eb), |
7518a238 | 938 | slot); |
be0e5c09 | 939 | } else { |
5f39d397 CM |
940 | return generic_bin_search(eb, |
941 | offsetof(struct btrfs_node, ptrs), | |
123abc88 | 942 | sizeof(struct btrfs_key_ptr), |
5f39d397 | 943 | key, btrfs_header_nritems(eb), |
7518a238 | 944 | slot); |
be0e5c09 CM |
945 | } |
946 | return -1; | |
947 | } | |
948 | ||
5d4f98a2 YZ |
949 | int btrfs_bin_search(struct extent_buffer *eb, struct btrfs_key *key, |
950 | int level, int *slot) | |
951 | { | |
952 | return bin_search(eb, key, level, slot); | |
953 | } | |
954 | ||
f0486c68 YZ |
955 | static void root_add_used(struct btrfs_root *root, u32 size) |
956 | { | |
957 | spin_lock(&root->accounting_lock); | |
958 | btrfs_set_root_used(&root->root_item, | |
959 | btrfs_root_used(&root->root_item) + size); | |
960 | spin_unlock(&root->accounting_lock); | |
961 | } | |
962 | ||
963 | static void root_sub_used(struct btrfs_root *root, u32 size) | |
964 | { | |
965 | spin_lock(&root->accounting_lock); | |
966 | btrfs_set_root_used(&root->root_item, | |
967 | btrfs_root_used(&root->root_item) - size); | |
968 | spin_unlock(&root->accounting_lock); | |
969 | } | |
970 | ||
d352ac68 CM |
971 | /* given a node and slot number, this reads the blocks it points to. The |
972 | * extent buffer is returned with a reference taken (but unlocked). | |
973 | * NULL is returned on error. | |
974 | */ | |
e02119d5 | 975 | static noinline struct extent_buffer *read_node_slot(struct btrfs_root *root, |
5f39d397 | 976 | struct extent_buffer *parent, int slot) |
bb803951 | 977 | { |
ca7a79ad | 978 | int level = btrfs_header_level(parent); |
bb803951 CM |
979 | if (slot < 0) |
980 | return NULL; | |
5f39d397 | 981 | if (slot >= btrfs_header_nritems(parent)) |
bb803951 | 982 | return NULL; |
ca7a79ad CM |
983 | |
984 | BUG_ON(level == 0); | |
985 | ||
db94535d | 986 | return read_tree_block(root, btrfs_node_blockptr(parent, slot), |
ca7a79ad CM |
987 | btrfs_level_size(root, level - 1), |
988 | btrfs_node_ptr_generation(parent, slot)); | |
bb803951 CM |
989 | } |
990 | ||
d352ac68 CM |
991 | /* |
992 | * node level balancing, used to make sure nodes are in proper order for | |
993 | * item deletion. We balance from the top down, so we have to make sure | |
994 | * that a deletion won't leave an node completely empty later on. | |
995 | */ | |
e02119d5 | 996 | static noinline int balance_level(struct btrfs_trans_handle *trans, |
98ed5174 CM |
997 | struct btrfs_root *root, |
998 | struct btrfs_path *path, int level) | |
bb803951 | 999 | { |
5f39d397 CM |
1000 | struct extent_buffer *right = NULL; |
1001 | struct extent_buffer *mid; | |
1002 | struct extent_buffer *left = NULL; | |
1003 | struct extent_buffer *parent = NULL; | |
bb803951 CM |
1004 | int ret = 0; |
1005 | int wret; | |
1006 | int pslot; | |
bb803951 | 1007 | int orig_slot = path->slots[level]; |
54aa1f4d | 1008 | int err_on_enospc = 0; |
79f95c82 | 1009 | u64 orig_ptr; |
bb803951 CM |
1010 | |
1011 | if (level == 0) | |
1012 | return 0; | |
1013 | ||
5f39d397 | 1014 | mid = path->nodes[level]; |
b4ce94de | 1015 | |
925baedd | 1016 | WARN_ON(!path->locks[level]); |
7bb86316 CM |
1017 | WARN_ON(btrfs_header_generation(mid) != trans->transid); |
1018 | ||
1d4f8a0c | 1019 | orig_ptr = btrfs_node_blockptr(mid, orig_slot); |
79f95c82 | 1020 | |
234b63a0 | 1021 | if (level < BTRFS_MAX_LEVEL - 1) |
5f39d397 | 1022 | parent = path->nodes[level + 1]; |
bb803951 CM |
1023 | pslot = path->slots[level + 1]; |
1024 | ||
40689478 CM |
1025 | /* |
1026 | * deal with the case where there is only one pointer in the root | |
1027 | * by promoting the node below to a root | |
1028 | */ | |
5f39d397 CM |
1029 | if (!parent) { |
1030 | struct extent_buffer *child; | |
bb803951 | 1031 | |
5f39d397 | 1032 | if (btrfs_header_nritems(mid) != 1) |
bb803951 CM |
1033 | return 0; |
1034 | ||
1035 | /* promote the child to a root */ | |
5f39d397 | 1036 | child = read_node_slot(root, mid, 0); |
7951f3ce | 1037 | BUG_ON(!child); |
925baedd | 1038 | btrfs_tree_lock(child); |
b4ce94de | 1039 | btrfs_set_lock_blocking(child); |
9fa8cfe7 | 1040 | ret = btrfs_cow_block(trans, root, child, mid, 0, &child); |
f0486c68 YZ |
1041 | if (ret) { |
1042 | btrfs_tree_unlock(child); | |
1043 | free_extent_buffer(child); | |
1044 | goto enospc; | |
1045 | } | |
2f375ab9 | 1046 | |
925baedd | 1047 | spin_lock(&root->node_lock); |
bb803951 | 1048 | root->node = child; |
925baedd CM |
1049 | spin_unlock(&root->node_lock); |
1050 | ||
0b86a832 | 1051 | add_root_to_dirty_list(root); |
925baedd | 1052 | btrfs_tree_unlock(child); |
b4ce94de | 1053 | |
925baedd | 1054 | path->locks[level] = 0; |
bb803951 | 1055 | path->nodes[level] = NULL; |
5f39d397 | 1056 | clean_tree_block(trans, root, mid); |
925baedd | 1057 | btrfs_tree_unlock(mid); |
bb803951 | 1058 | /* once for the path */ |
5f39d397 | 1059 | free_extent_buffer(mid); |
f0486c68 YZ |
1060 | |
1061 | root_sub_used(root, mid->len); | |
1062 | btrfs_free_tree_block(trans, root, mid, 0, 1); | |
bb803951 | 1063 | /* once for the root ptr */ |
5f39d397 | 1064 | free_extent_buffer(mid); |
f0486c68 | 1065 | return 0; |
bb803951 | 1066 | } |
5f39d397 | 1067 | if (btrfs_header_nritems(mid) > |
123abc88 | 1068 | BTRFS_NODEPTRS_PER_BLOCK(root) / 4) |
bb803951 CM |
1069 | return 0; |
1070 | ||
5f39d397 | 1071 | if (btrfs_header_nritems(mid) < 2) |
54aa1f4d CM |
1072 | err_on_enospc = 1; |
1073 | ||
5f39d397 CM |
1074 | left = read_node_slot(root, parent, pslot - 1); |
1075 | if (left) { | |
925baedd | 1076 | btrfs_tree_lock(left); |
b4ce94de | 1077 | btrfs_set_lock_blocking(left); |
5f39d397 | 1078 | wret = btrfs_cow_block(trans, root, left, |
9fa8cfe7 | 1079 | parent, pslot - 1, &left); |
54aa1f4d CM |
1080 | if (wret) { |
1081 | ret = wret; | |
1082 | goto enospc; | |
1083 | } | |
2cc58cf2 | 1084 | } |
5f39d397 CM |
1085 | right = read_node_slot(root, parent, pslot + 1); |
1086 | if (right) { | |
925baedd | 1087 | btrfs_tree_lock(right); |
b4ce94de | 1088 | btrfs_set_lock_blocking(right); |
5f39d397 | 1089 | wret = btrfs_cow_block(trans, root, right, |
9fa8cfe7 | 1090 | parent, pslot + 1, &right); |
2cc58cf2 CM |
1091 | if (wret) { |
1092 | ret = wret; | |
1093 | goto enospc; | |
1094 | } | |
1095 | } | |
1096 | ||
1097 | /* first, try to make some room in the middle buffer */ | |
5f39d397 CM |
1098 | if (left) { |
1099 | orig_slot += btrfs_header_nritems(left); | |
bce4eae9 | 1100 | wret = push_node_left(trans, root, left, mid, 1); |
79f95c82 CM |
1101 | if (wret < 0) |
1102 | ret = wret; | |
5f39d397 | 1103 | if (btrfs_header_nritems(mid) < 2) |
54aa1f4d | 1104 | err_on_enospc = 1; |
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]; | |
1224 | u64 orig_ptr; | |
1225 | ||
1226 | if (level == 0) | |
1227 | return 1; | |
1228 | ||
5f39d397 | 1229 | mid = path->nodes[level]; |
7bb86316 | 1230 | WARN_ON(btrfs_header_generation(mid) != trans->transid); |
e66f709b CM |
1231 | orig_ptr = btrfs_node_blockptr(mid, orig_slot); |
1232 | ||
1233 | if (level < BTRFS_MAX_LEVEL - 1) | |
5f39d397 | 1234 | parent = path->nodes[level + 1]; |
e66f709b CM |
1235 | pslot = path->slots[level + 1]; |
1236 | ||
5f39d397 | 1237 | if (!parent) |
e66f709b | 1238 | return 1; |
e66f709b | 1239 | |
5f39d397 | 1240 | left = read_node_slot(root, parent, pslot - 1); |
e66f709b CM |
1241 | |
1242 | /* first, try to make some room in the middle buffer */ | |
5f39d397 | 1243 | if (left) { |
e66f709b | 1244 | u32 left_nr; |
925baedd CM |
1245 | |
1246 | btrfs_tree_lock(left); | |
b4ce94de CM |
1247 | btrfs_set_lock_blocking(left); |
1248 | ||
5f39d397 | 1249 | left_nr = btrfs_header_nritems(left); |
33ade1f8 CM |
1250 | if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) { |
1251 | wret = 1; | |
1252 | } else { | |
5f39d397 | 1253 | ret = btrfs_cow_block(trans, root, left, parent, |
9fa8cfe7 | 1254 | pslot - 1, &left); |
54aa1f4d CM |
1255 | if (ret) |
1256 | wret = 1; | |
1257 | else { | |
54aa1f4d | 1258 | wret = push_node_left(trans, root, |
971a1f66 | 1259 | left, mid, 0); |
54aa1f4d | 1260 | } |
33ade1f8 | 1261 | } |
e66f709b CM |
1262 | if (wret < 0) |
1263 | ret = wret; | |
1264 | if (wret == 0) { | |
5f39d397 | 1265 | struct btrfs_disk_key disk_key; |
e66f709b | 1266 | orig_slot += left_nr; |
5f39d397 CM |
1267 | btrfs_node_key(mid, &disk_key, 0); |
1268 | btrfs_set_node_key(parent, &disk_key, pslot); | |
1269 | btrfs_mark_buffer_dirty(parent); | |
1270 | if (btrfs_header_nritems(left) > orig_slot) { | |
1271 | path->nodes[level] = left; | |
e66f709b CM |
1272 | path->slots[level + 1] -= 1; |
1273 | path->slots[level] = orig_slot; | |
925baedd | 1274 | btrfs_tree_unlock(mid); |
5f39d397 | 1275 | free_extent_buffer(mid); |
e66f709b CM |
1276 | } else { |
1277 | orig_slot -= | |
5f39d397 | 1278 | btrfs_header_nritems(left); |
e66f709b | 1279 | path->slots[level] = orig_slot; |
925baedd | 1280 | btrfs_tree_unlock(left); |
5f39d397 | 1281 | free_extent_buffer(left); |
e66f709b | 1282 | } |
e66f709b CM |
1283 | return 0; |
1284 | } | |
925baedd | 1285 | btrfs_tree_unlock(left); |
5f39d397 | 1286 | free_extent_buffer(left); |
e66f709b | 1287 | } |
925baedd | 1288 | right = read_node_slot(root, parent, pslot + 1); |
e66f709b CM |
1289 | |
1290 | /* | |
1291 | * then try to empty the right most buffer into the middle | |
1292 | */ | |
5f39d397 | 1293 | if (right) { |
33ade1f8 | 1294 | u32 right_nr; |
b4ce94de | 1295 | |
925baedd | 1296 | btrfs_tree_lock(right); |
b4ce94de CM |
1297 | btrfs_set_lock_blocking(right); |
1298 | ||
5f39d397 | 1299 | right_nr = btrfs_header_nritems(right); |
33ade1f8 CM |
1300 | if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) { |
1301 | wret = 1; | |
1302 | } else { | |
5f39d397 CM |
1303 | ret = btrfs_cow_block(trans, root, right, |
1304 | parent, pslot + 1, | |
9fa8cfe7 | 1305 | &right); |
54aa1f4d CM |
1306 | if (ret) |
1307 | wret = 1; | |
1308 | else { | |
54aa1f4d | 1309 | wret = balance_node_right(trans, root, |
5f39d397 | 1310 | right, mid); |
54aa1f4d | 1311 | } |
33ade1f8 | 1312 | } |
e66f709b CM |
1313 | if (wret < 0) |
1314 | ret = wret; | |
1315 | if (wret == 0) { | |
5f39d397 CM |
1316 | struct btrfs_disk_key disk_key; |
1317 | ||
1318 | btrfs_node_key(right, &disk_key, 0); | |
1319 | btrfs_set_node_key(parent, &disk_key, pslot + 1); | |
1320 | btrfs_mark_buffer_dirty(parent); | |
1321 | ||
1322 | if (btrfs_header_nritems(mid) <= orig_slot) { | |
1323 | path->nodes[level] = right; | |
e66f709b CM |
1324 | path->slots[level + 1] += 1; |
1325 | path->slots[level] = orig_slot - | |
5f39d397 | 1326 | btrfs_header_nritems(mid); |
925baedd | 1327 | btrfs_tree_unlock(mid); |
5f39d397 | 1328 | free_extent_buffer(mid); |
e66f709b | 1329 | } else { |
925baedd | 1330 | btrfs_tree_unlock(right); |
5f39d397 | 1331 | free_extent_buffer(right); |
e66f709b | 1332 | } |
e66f709b CM |
1333 | return 0; |
1334 | } | |
925baedd | 1335 | btrfs_tree_unlock(right); |
5f39d397 | 1336 | free_extent_buffer(right); |
e66f709b | 1337 | } |
e66f709b CM |
1338 | return 1; |
1339 | } | |
1340 | ||
3c69faec | 1341 | /* |
d352ac68 CM |
1342 | * readahead one full node of leaves, finding things that are close |
1343 | * to the block in 'slot', and triggering ra on them. | |
3c69faec | 1344 | */ |
c8c42864 CM |
1345 | static void reada_for_search(struct btrfs_root *root, |
1346 | struct btrfs_path *path, | |
1347 | int level, int slot, u64 objectid) | |
3c69faec | 1348 | { |
5f39d397 | 1349 | struct extent_buffer *node; |
01f46658 | 1350 | struct btrfs_disk_key disk_key; |
3c69faec | 1351 | u32 nritems; |
3c69faec | 1352 | u64 search; |
a7175319 | 1353 | u64 target; |
6b80053d | 1354 | u64 nread = 0; |
3c69faec | 1355 | int direction = path->reada; |
5f39d397 | 1356 | struct extent_buffer *eb; |
6b80053d CM |
1357 | u32 nr; |
1358 | u32 blocksize; | |
1359 | u32 nscan = 0; | |
db94535d | 1360 | |
a6b6e75e | 1361 | if (level != 1) |
6702ed49 CM |
1362 | return; |
1363 | ||
1364 | if (!path->nodes[level]) | |
3c69faec CM |
1365 | return; |
1366 | ||
5f39d397 | 1367 | node = path->nodes[level]; |
925baedd | 1368 | |
3c69faec | 1369 | search = btrfs_node_blockptr(node, slot); |
6b80053d CM |
1370 | blocksize = btrfs_level_size(root, level - 1); |
1371 | eb = btrfs_find_tree_block(root, search, blocksize); | |
5f39d397 CM |
1372 | if (eb) { |
1373 | free_extent_buffer(eb); | |
3c69faec CM |
1374 | return; |
1375 | } | |
1376 | ||
a7175319 | 1377 | target = search; |
6b80053d | 1378 | |
5f39d397 | 1379 | nritems = btrfs_header_nritems(node); |
6b80053d | 1380 | nr = slot; |
d397712b | 1381 | while (1) { |
6b80053d CM |
1382 | if (direction < 0) { |
1383 | if (nr == 0) | |
1384 | break; | |
1385 | nr--; | |
1386 | } else if (direction > 0) { | |
1387 | nr++; | |
1388 | if (nr >= nritems) | |
1389 | break; | |
3c69faec | 1390 | } |
01f46658 CM |
1391 | if (path->reada < 0 && objectid) { |
1392 | btrfs_node_key(node, &disk_key, nr); | |
1393 | if (btrfs_disk_key_objectid(&disk_key) != objectid) | |
1394 | break; | |
1395 | } | |
6b80053d | 1396 | search = btrfs_node_blockptr(node, nr); |
a7175319 CM |
1397 | if ((search <= target && target - search <= 65536) || |
1398 | (search > target && search - target <= 65536)) { | |
ca7a79ad CM |
1399 | readahead_tree_block(root, search, blocksize, |
1400 | btrfs_node_ptr_generation(node, nr)); | |
6b80053d CM |
1401 | nread += blocksize; |
1402 | } | |
1403 | nscan++; | |
a7175319 | 1404 | if ((nread > 65536 || nscan > 32)) |
6b80053d | 1405 | break; |
3c69faec CM |
1406 | } |
1407 | } | |
925baedd | 1408 | |
b4ce94de CM |
1409 | /* |
1410 | * returns -EAGAIN if it had to drop the path, or zero if everything was in | |
1411 | * cache | |
1412 | */ | |
1413 | static noinline int reada_for_balance(struct btrfs_root *root, | |
1414 | struct btrfs_path *path, int level) | |
1415 | { | |
1416 | int slot; | |
1417 | int nritems; | |
1418 | struct extent_buffer *parent; | |
1419 | struct extent_buffer *eb; | |
1420 | u64 gen; | |
1421 | u64 block1 = 0; | |
1422 | u64 block2 = 0; | |
1423 | int ret = 0; | |
1424 | int blocksize; | |
1425 | ||
8c594ea8 | 1426 | parent = path->nodes[level + 1]; |
b4ce94de CM |
1427 | if (!parent) |
1428 | return 0; | |
1429 | ||
1430 | nritems = btrfs_header_nritems(parent); | |
8c594ea8 | 1431 | slot = path->slots[level + 1]; |
b4ce94de CM |
1432 | blocksize = btrfs_level_size(root, level); |
1433 | ||
1434 | if (slot > 0) { | |
1435 | block1 = btrfs_node_blockptr(parent, slot - 1); | |
1436 | gen = btrfs_node_ptr_generation(parent, slot - 1); | |
1437 | eb = btrfs_find_tree_block(root, block1, blocksize); | |
1438 | if (eb && btrfs_buffer_uptodate(eb, gen)) | |
1439 | block1 = 0; | |
1440 | free_extent_buffer(eb); | |
1441 | } | |
8c594ea8 | 1442 | if (slot + 1 < nritems) { |
b4ce94de CM |
1443 | block2 = btrfs_node_blockptr(parent, slot + 1); |
1444 | gen = btrfs_node_ptr_generation(parent, slot + 1); | |
1445 | eb = btrfs_find_tree_block(root, block2, blocksize); | |
1446 | if (eb && btrfs_buffer_uptodate(eb, gen)) | |
1447 | block2 = 0; | |
1448 | free_extent_buffer(eb); | |
1449 | } | |
1450 | if (block1 || block2) { | |
1451 | ret = -EAGAIN; | |
8c594ea8 CM |
1452 | |
1453 | /* release the whole path */ | |
b4ce94de | 1454 | btrfs_release_path(root, path); |
8c594ea8 CM |
1455 | |
1456 | /* read the blocks */ | |
b4ce94de CM |
1457 | if (block1) |
1458 | readahead_tree_block(root, block1, blocksize, 0); | |
1459 | if (block2) | |
1460 | readahead_tree_block(root, block2, blocksize, 0); | |
1461 | ||
1462 | if (block1) { | |
1463 | eb = read_tree_block(root, block1, blocksize, 0); | |
1464 | free_extent_buffer(eb); | |
1465 | } | |
8c594ea8 | 1466 | if (block2) { |
b4ce94de CM |
1467 | eb = read_tree_block(root, block2, blocksize, 0); |
1468 | free_extent_buffer(eb); | |
1469 | } | |
1470 | } | |
1471 | return ret; | |
1472 | } | |
1473 | ||
1474 | ||
d352ac68 | 1475 | /* |
d397712b CM |
1476 | * when we walk down the tree, it is usually safe to unlock the higher layers |
1477 | * in the tree. The exceptions are when our path goes through slot 0, because | |
1478 | * operations on the tree might require changing key pointers higher up in the | |
1479 | * tree. | |
d352ac68 | 1480 | * |
d397712b CM |
1481 | * callers might also have set path->keep_locks, which tells this code to keep |
1482 | * the lock if the path points to the last slot in the block. This is part of | |
1483 | * walking through the tree, and selecting the next slot in the higher block. | |
d352ac68 | 1484 | * |
d397712b CM |
1485 | * lowest_unlock sets the lowest level in the tree we're allowed to unlock. so |
1486 | * if lowest_unlock is 1, level 0 won't be unlocked | |
d352ac68 | 1487 | */ |
e02119d5 CM |
1488 | static noinline void unlock_up(struct btrfs_path *path, int level, |
1489 | int lowest_unlock) | |
925baedd CM |
1490 | { |
1491 | int i; | |
1492 | int skip_level = level; | |
051e1b9f | 1493 | int no_skips = 0; |
925baedd CM |
1494 | struct extent_buffer *t; |
1495 | ||
1496 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { | |
1497 | if (!path->nodes[i]) | |
1498 | break; | |
1499 | if (!path->locks[i]) | |
1500 | break; | |
051e1b9f | 1501 | if (!no_skips && path->slots[i] == 0) { |
925baedd CM |
1502 | skip_level = i + 1; |
1503 | continue; | |
1504 | } | |
051e1b9f | 1505 | if (!no_skips && path->keep_locks) { |
925baedd CM |
1506 | u32 nritems; |
1507 | t = path->nodes[i]; | |
1508 | nritems = btrfs_header_nritems(t); | |
051e1b9f | 1509 | if (nritems < 1 || path->slots[i] >= nritems - 1) { |
925baedd CM |
1510 | skip_level = i + 1; |
1511 | continue; | |
1512 | } | |
1513 | } | |
051e1b9f CM |
1514 | if (skip_level < i && i >= lowest_unlock) |
1515 | no_skips = 1; | |
1516 | ||
925baedd CM |
1517 | t = path->nodes[i]; |
1518 | if (i >= lowest_unlock && i > skip_level && path->locks[i]) { | |
1519 | btrfs_tree_unlock(t); | |
1520 | path->locks[i] = 0; | |
1521 | } | |
1522 | } | |
1523 | } | |
1524 | ||
b4ce94de CM |
1525 | /* |
1526 | * This releases any locks held in the path starting at level and | |
1527 | * going all the way up to the root. | |
1528 | * | |
1529 | * btrfs_search_slot will keep the lock held on higher nodes in a few | |
1530 | * corner cases, such as COW of the block at slot zero in the node. This | |
1531 | * ignores those rules, and it should only be called when there are no | |
1532 | * more updates to be done higher up in the tree. | |
1533 | */ | |
1534 | noinline void btrfs_unlock_up_safe(struct btrfs_path *path, int level) | |
1535 | { | |
1536 | int i; | |
1537 | ||
5d4f98a2 | 1538 | if (path->keep_locks) |
b4ce94de CM |
1539 | return; |
1540 | ||
1541 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { | |
1542 | if (!path->nodes[i]) | |
12f4dacc | 1543 | continue; |
b4ce94de | 1544 | if (!path->locks[i]) |
12f4dacc | 1545 | continue; |
b4ce94de CM |
1546 | btrfs_tree_unlock(path->nodes[i]); |
1547 | path->locks[i] = 0; | |
1548 | } | |
1549 | } | |
1550 | ||
c8c42864 CM |
1551 | /* |
1552 | * helper function for btrfs_search_slot. The goal is to find a block | |
1553 | * in cache without setting the path to blocking. If we find the block | |
1554 | * we return zero and the path is unchanged. | |
1555 | * | |
1556 | * If we can't find the block, we set the path blocking and do some | |
1557 | * reada. -EAGAIN is returned and the search must be repeated. | |
1558 | */ | |
1559 | static int | |
1560 | read_block_for_search(struct btrfs_trans_handle *trans, | |
1561 | struct btrfs_root *root, struct btrfs_path *p, | |
1562 | struct extent_buffer **eb_ret, int level, int slot, | |
1563 | struct btrfs_key *key) | |
1564 | { | |
1565 | u64 blocknr; | |
1566 | u64 gen; | |
1567 | u32 blocksize; | |
1568 | struct extent_buffer *b = *eb_ret; | |
1569 | struct extent_buffer *tmp; | |
76a05b35 | 1570 | int ret; |
c8c42864 CM |
1571 | |
1572 | blocknr = btrfs_node_blockptr(b, slot); | |
1573 | gen = btrfs_node_ptr_generation(b, slot); | |
1574 | blocksize = btrfs_level_size(root, level - 1); | |
1575 | ||
1576 | tmp = btrfs_find_tree_block(root, blocknr, blocksize); | |
1577 | if (tmp && btrfs_buffer_uptodate(tmp, gen)) { | |
76a05b35 CM |
1578 | /* |
1579 | * we found an up to date block without sleeping, return | |
1580 | * right away | |
1581 | */ | |
c8c42864 CM |
1582 | *eb_ret = tmp; |
1583 | return 0; | |
1584 | } | |
1585 | ||
1586 | /* | |
1587 | * reduce lock contention at high levels | |
1588 | * of the btree by dropping locks before | |
76a05b35 CM |
1589 | * we read. Don't release the lock on the current |
1590 | * level because we need to walk this node to figure | |
1591 | * out which blocks to read. | |
c8c42864 | 1592 | */ |
8c594ea8 CM |
1593 | btrfs_unlock_up_safe(p, level + 1); |
1594 | btrfs_set_path_blocking(p); | |
1595 | ||
c8c42864 CM |
1596 | if (tmp) |
1597 | free_extent_buffer(tmp); | |
1598 | if (p->reada) | |
1599 | reada_for_search(root, p, level, slot, key->objectid); | |
1600 | ||
8c594ea8 | 1601 | btrfs_release_path(NULL, p); |
76a05b35 CM |
1602 | |
1603 | ret = -EAGAIN; | |
c8c42864 | 1604 | tmp = read_tree_block(root, blocknr, blocksize, gen); |
76a05b35 CM |
1605 | if (tmp) { |
1606 | /* | |
1607 | * If the read above didn't mark this buffer up to date, | |
1608 | * it will never end up being up to date. Set ret to EIO now | |
1609 | * and give up so that our caller doesn't loop forever | |
1610 | * on our EAGAINs. | |
1611 | */ | |
1612 | if (!btrfs_buffer_uptodate(tmp, 0)) | |
1613 | ret = -EIO; | |
c8c42864 | 1614 | free_extent_buffer(tmp); |
76a05b35 CM |
1615 | } |
1616 | return ret; | |
c8c42864 CM |
1617 | } |
1618 | ||
1619 | /* | |
1620 | * helper function for btrfs_search_slot. This does all of the checks | |
1621 | * for node-level blocks and does any balancing required based on | |
1622 | * the ins_len. | |
1623 | * | |
1624 | * If no extra work was required, zero is returned. If we had to | |
1625 | * drop the path, -EAGAIN is returned and btrfs_search_slot must | |
1626 | * start over | |
1627 | */ | |
1628 | static int | |
1629 | setup_nodes_for_search(struct btrfs_trans_handle *trans, | |
1630 | struct btrfs_root *root, struct btrfs_path *p, | |
1631 | struct extent_buffer *b, int level, int ins_len) | |
1632 | { | |
1633 | int ret; | |
1634 | if ((p->search_for_split || ins_len > 0) && btrfs_header_nritems(b) >= | |
1635 | BTRFS_NODEPTRS_PER_BLOCK(root) - 3) { | |
1636 | int sret; | |
1637 | ||
1638 | sret = reada_for_balance(root, p, level); | |
1639 | if (sret) | |
1640 | goto again; | |
1641 | ||
1642 | btrfs_set_path_blocking(p); | |
1643 | sret = split_node(trans, root, p, level); | |
1644 | btrfs_clear_path_blocking(p, NULL); | |
1645 | ||
1646 | BUG_ON(sret > 0); | |
1647 | if (sret) { | |
1648 | ret = sret; | |
1649 | goto done; | |
1650 | } | |
1651 | b = p->nodes[level]; | |
1652 | } else if (ins_len < 0 && btrfs_header_nritems(b) < | |
cfbb9308 | 1653 | BTRFS_NODEPTRS_PER_BLOCK(root) / 2) { |
c8c42864 CM |
1654 | int sret; |
1655 | ||
1656 | sret = reada_for_balance(root, p, level); | |
1657 | if (sret) | |
1658 | goto again; | |
1659 | ||
1660 | btrfs_set_path_blocking(p); | |
1661 | sret = balance_level(trans, root, p, level); | |
1662 | btrfs_clear_path_blocking(p, NULL); | |
1663 | ||
1664 | if (sret) { | |
1665 | ret = sret; | |
1666 | goto done; | |
1667 | } | |
1668 | b = p->nodes[level]; | |
1669 | if (!b) { | |
1670 | btrfs_release_path(NULL, p); | |
1671 | goto again; | |
1672 | } | |
1673 | BUG_ON(btrfs_header_nritems(b) == 1); | |
1674 | } | |
1675 | return 0; | |
1676 | ||
1677 | again: | |
1678 | ret = -EAGAIN; | |
1679 | done: | |
1680 | return ret; | |
1681 | } | |
1682 | ||
74123bd7 CM |
1683 | /* |
1684 | * look for key in the tree. path is filled in with nodes along the way | |
1685 | * if key is found, we return zero and you can find the item in the leaf | |
1686 | * level of the path (level 0) | |
1687 | * | |
1688 | * If the key isn't found, the path points to the slot where it should | |
aa5d6bed CM |
1689 | * be inserted, and 1 is returned. If there are other errors during the |
1690 | * search a negative error number is returned. | |
97571fd0 CM |
1691 | * |
1692 | * if ins_len > 0, nodes and leaves will be split as we walk down the | |
1693 | * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if | |
1694 | * possible) | |
74123bd7 | 1695 | */ |
e089f05c CM |
1696 | int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root |
1697 | *root, struct btrfs_key *key, struct btrfs_path *p, int | |
1698 | ins_len, int cow) | |
be0e5c09 | 1699 | { |
5f39d397 | 1700 | struct extent_buffer *b; |
be0e5c09 CM |
1701 | int slot; |
1702 | int ret; | |
33c66f43 | 1703 | int err; |
be0e5c09 | 1704 | int level; |
925baedd | 1705 | int lowest_unlock = 1; |
9f3a7427 CM |
1706 | u8 lowest_level = 0; |
1707 | ||
6702ed49 | 1708 | lowest_level = p->lowest_level; |
323ac95b | 1709 | WARN_ON(lowest_level && ins_len > 0); |
22b0ebda | 1710 | WARN_ON(p->nodes[0] != NULL); |
25179201 | 1711 | |
925baedd CM |
1712 | if (ins_len < 0) |
1713 | lowest_unlock = 2; | |
65b51a00 | 1714 | |
bb803951 | 1715 | again: |
5d4f98a2 YZ |
1716 | if (p->search_commit_root) { |
1717 | b = root->commit_root; | |
1718 | extent_buffer_get(b); | |
1719 | if (!p->skip_locking) | |
1720 | btrfs_tree_lock(b); | |
1721 | } else { | |
1722 | if (p->skip_locking) | |
1723 | b = btrfs_root_node(root); | |
1724 | else | |
1725 | b = btrfs_lock_root_node(root); | |
1726 | } | |
925baedd | 1727 | |
eb60ceac | 1728 | while (b) { |
5f39d397 | 1729 | level = btrfs_header_level(b); |
65b51a00 CM |
1730 | |
1731 | /* | |
1732 | * setup the path here so we can release it under lock | |
1733 | * contention with the cow code | |
1734 | */ | |
1735 | p->nodes[level] = b; | |
1736 | if (!p->skip_locking) | |
1737 | p->locks[level] = 1; | |
1738 | ||
02217ed2 | 1739 | if (cow) { |
c8c42864 CM |
1740 | /* |
1741 | * if we don't really need to cow this block | |
1742 | * then we don't want to set the path blocking, | |
1743 | * so we test it here | |
1744 | */ | |
5d4f98a2 | 1745 | if (!should_cow_block(trans, root, b)) |
65b51a00 | 1746 | goto cow_done; |
5d4f98a2 | 1747 | |
b4ce94de CM |
1748 | btrfs_set_path_blocking(p); |
1749 | ||
33c66f43 YZ |
1750 | err = btrfs_cow_block(trans, root, b, |
1751 | p->nodes[level + 1], | |
1752 | p->slots[level + 1], &b); | |
1753 | if (err) { | |
33c66f43 | 1754 | ret = err; |
65b51a00 | 1755 | goto done; |
54aa1f4d | 1756 | } |
02217ed2 | 1757 | } |
65b51a00 | 1758 | cow_done: |
02217ed2 | 1759 | BUG_ON(!cow && ins_len); |
5f39d397 | 1760 | if (level != btrfs_header_level(b)) |
2c90e5d6 | 1761 | WARN_ON(1); |
5f39d397 | 1762 | level = btrfs_header_level(b); |
65b51a00 | 1763 | |
eb60ceac | 1764 | p->nodes[level] = b; |
5cd57b2c CM |
1765 | if (!p->skip_locking) |
1766 | p->locks[level] = 1; | |
65b51a00 | 1767 | |
4008c04a | 1768 | btrfs_clear_path_blocking(p, NULL); |
b4ce94de CM |
1769 | |
1770 | /* | |
1771 | * we have a lock on b and as long as we aren't changing | |
1772 | * the tree, there is no way to for the items in b to change. | |
1773 | * It is safe to drop the lock on our parent before we | |
1774 | * go through the expensive btree search on b. | |
1775 | * | |
1776 | * If cow is true, then we might be changing slot zero, | |
1777 | * which may require changing the parent. So, we can't | |
1778 | * drop the lock until after we know which slot we're | |
1779 | * operating on. | |
1780 | */ | |
1781 | if (!cow) | |
1782 | btrfs_unlock_up_safe(p, level + 1); | |
1783 | ||
123abc88 | 1784 | ret = check_block(root, p, level); |
65b51a00 CM |
1785 | if (ret) { |
1786 | ret = -1; | |
1787 | goto done; | |
1788 | } | |
925baedd | 1789 | |
5f39d397 | 1790 | ret = bin_search(b, key, level, &slot); |
b4ce94de | 1791 | |
5f39d397 | 1792 | if (level != 0) { |
33c66f43 YZ |
1793 | int dec = 0; |
1794 | if (ret && slot > 0) { | |
1795 | dec = 1; | |
be0e5c09 | 1796 | slot -= 1; |
33c66f43 | 1797 | } |
be0e5c09 | 1798 | p->slots[level] = slot; |
33c66f43 | 1799 | err = setup_nodes_for_search(trans, root, p, b, level, |
c8c42864 | 1800 | ins_len); |
33c66f43 | 1801 | if (err == -EAGAIN) |
c8c42864 | 1802 | goto again; |
33c66f43 YZ |
1803 | if (err) { |
1804 | ret = err; | |
c8c42864 | 1805 | goto done; |
33c66f43 | 1806 | } |
c8c42864 CM |
1807 | b = p->nodes[level]; |
1808 | slot = p->slots[level]; | |
b4ce94de | 1809 | |
f9efa9c7 CM |
1810 | unlock_up(p, level, lowest_unlock); |
1811 | ||
925baedd | 1812 | if (level == lowest_level) { |
33c66f43 YZ |
1813 | if (dec) |
1814 | p->slots[level]++; | |
5b21f2ed | 1815 | goto done; |
925baedd | 1816 | } |
ca7a79ad | 1817 | |
33c66f43 | 1818 | err = read_block_for_search(trans, root, p, |
c8c42864 | 1819 | &b, level, slot, key); |
33c66f43 | 1820 | if (err == -EAGAIN) |
c8c42864 | 1821 | goto again; |
33c66f43 YZ |
1822 | if (err) { |
1823 | ret = err; | |
76a05b35 | 1824 | goto done; |
33c66f43 | 1825 | } |
76a05b35 | 1826 | |
b4ce94de | 1827 | if (!p->skip_locking) { |
4008c04a | 1828 | btrfs_clear_path_blocking(p, NULL); |
33c66f43 | 1829 | err = btrfs_try_spin_lock(b); |
b4ce94de | 1830 | |
33c66f43 | 1831 | if (!err) { |
b4ce94de CM |
1832 | btrfs_set_path_blocking(p); |
1833 | btrfs_tree_lock(b); | |
4008c04a | 1834 | btrfs_clear_path_blocking(p, b); |
b4ce94de CM |
1835 | } |
1836 | } | |
be0e5c09 CM |
1837 | } else { |
1838 | p->slots[level] = slot; | |
87b29b20 YZ |
1839 | if (ins_len > 0 && |
1840 | btrfs_leaf_free_space(root, b) < ins_len) { | |
b4ce94de | 1841 | btrfs_set_path_blocking(p); |
33c66f43 YZ |
1842 | err = split_leaf(trans, root, key, |
1843 | p, ins_len, ret == 0); | |
4008c04a | 1844 | btrfs_clear_path_blocking(p, NULL); |
b4ce94de | 1845 | |
33c66f43 YZ |
1846 | BUG_ON(err > 0); |
1847 | if (err) { | |
1848 | ret = err; | |
65b51a00 CM |
1849 | goto done; |
1850 | } | |
5c680ed6 | 1851 | } |
459931ec CM |
1852 | if (!p->search_for_split) |
1853 | unlock_up(p, level, lowest_unlock); | |
65b51a00 | 1854 | goto done; |
be0e5c09 CM |
1855 | } |
1856 | } | |
65b51a00 CM |
1857 | ret = 1; |
1858 | done: | |
b4ce94de CM |
1859 | /* |
1860 | * we don't really know what they plan on doing with the path | |
1861 | * from here on, so for now just mark it as blocking | |
1862 | */ | |
b9473439 CM |
1863 | if (!p->leave_spinning) |
1864 | btrfs_set_path_blocking(p); | |
76a05b35 CM |
1865 | if (ret < 0) |
1866 | btrfs_release_path(root, p); | |
65b51a00 | 1867 | return ret; |
be0e5c09 CM |
1868 | } |
1869 | ||
74123bd7 CM |
1870 | /* |
1871 | * adjust the pointers going up the tree, starting at level | |
1872 | * making sure the right key of each node is points to 'key'. | |
1873 | * This is used after shifting pointers to the left, so it stops | |
1874 | * fixing up pointers when a given leaf/node is not in slot 0 of the | |
1875 | * higher levels | |
aa5d6bed CM |
1876 | * |
1877 | * If this fails to write a tree block, it returns -1, but continues | |
1878 | * fixing up the blocks in ram so the tree is consistent. | |
74123bd7 | 1879 | */ |
5f39d397 CM |
1880 | static int fixup_low_keys(struct btrfs_trans_handle *trans, |
1881 | struct btrfs_root *root, struct btrfs_path *path, | |
1882 | struct btrfs_disk_key *key, int level) | |
be0e5c09 CM |
1883 | { |
1884 | int i; | |
aa5d6bed | 1885 | int ret = 0; |
5f39d397 CM |
1886 | struct extent_buffer *t; |
1887 | ||
234b63a0 | 1888 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { |
be0e5c09 | 1889 | int tslot = path->slots[i]; |
eb60ceac | 1890 | if (!path->nodes[i]) |
be0e5c09 | 1891 | break; |
5f39d397 CM |
1892 | t = path->nodes[i]; |
1893 | btrfs_set_node_key(t, key, tslot); | |
d6025579 | 1894 | btrfs_mark_buffer_dirty(path->nodes[i]); |
be0e5c09 CM |
1895 | if (tslot != 0) |
1896 | break; | |
1897 | } | |
aa5d6bed | 1898 | return ret; |
be0e5c09 CM |
1899 | } |
1900 | ||
31840ae1 ZY |
1901 | /* |
1902 | * update item key. | |
1903 | * | |
1904 | * This function isn't completely safe. It's the caller's responsibility | |
1905 | * that the new key won't break the order | |
1906 | */ | |
1907 | int btrfs_set_item_key_safe(struct btrfs_trans_handle *trans, | |
1908 | struct btrfs_root *root, struct btrfs_path *path, | |
1909 | struct btrfs_key *new_key) | |
1910 | { | |
1911 | struct btrfs_disk_key disk_key; | |
1912 | struct extent_buffer *eb; | |
1913 | int slot; | |
1914 | ||
1915 | eb = path->nodes[0]; | |
1916 | slot = path->slots[0]; | |
1917 | if (slot > 0) { | |
1918 | btrfs_item_key(eb, &disk_key, slot - 1); | |
1919 | if (comp_keys(&disk_key, new_key) >= 0) | |
1920 | return -1; | |
1921 | } | |
1922 | if (slot < btrfs_header_nritems(eb) - 1) { | |
1923 | btrfs_item_key(eb, &disk_key, slot + 1); | |
1924 | if (comp_keys(&disk_key, new_key) <= 0) | |
1925 | return -1; | |
1926 | } | |
1927 | ||
1928 | btrfs_cpu_key_to_disk(&disk_key, new_key); | |
1929 | btrfs_set_item_key(eb, &disk_key, slot); | |
1930 | btrfs_mark_buffer_dirty(eb); | |
1931 | if (slot == 0) | |
1932 | fixup_low_keys(trans, root, path, &disk_key, 1); | |
1933 | return 0; | |
1934 | } | |
1935 | ||
74123bd7 CM |
1936 | /* |
1937 | * try to push data from one node into the next node left in the | |
79f95c82 | 1938 | * tree. |
aa5d6bed CM |
1939 | * |
1940 | * returns 0 if some ptrs were pushed left, < 0 if there was some horrible | |
1941 | * error, and > 0 if there was no room in the left hand block. | |
74123bd7 | 1942 | */ |
98ed5174 CM |
1943 | static int push_node_left(struct btrfs_trans_handle *trans, |
1944 | struct btrfs_root *root, struct extent_buffer *dst, | |
971a1f66 | 1945 | struct extent_buffer *src, int empty) |
be0e5c09 | 1946 | { |
be0e5c09 | 1947 | int push_items = 0; |
bb803951 CM |
1948 | int src_nritems; |
1949 | int dst_nritems; | |
aa5d6bed | 1950 | int ret = 0; |
be0e5c09 | 1951 | |
5f39d397 CM |
1952 | src_nritems = btrfs_header_nritems(src); |
1953 | dst_nritems = btrfs_header_nritems(dst); | |
123abc88 | 1954 | push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems; |
7bb86316 CM |
1955 | WARN_ON(btrfs_header_generation(src) != trans->transid); |
1956 | WARN_ON(btrfs_header_generation(dst) != trans->transid); | |
54aa1f4d | 1957 | |
bce4eae9 | 1958 | if (!empty && src_nritems <= 8) |
971a1f66 CM |
1959 | return 1; |
1960 | ||
d397712b | 1961 | if (push_items <= 0) |
be0e5c09 CM |
1962 | return 1; |
1963 | ||
bce4eae9 | 1964 | if (empty) { |
971a1f66 | 1965 | push_items = min(src_nritems, push_items); |
bce4eae9 CM |
1966 | if (push_items < src_nritems) { |
1967 | /* leave at least 8 pointers in the node if | |
1968 | * we aren't going to empty it | |
1969 | */ | |
1970 | if (src_nritems - push_items < 8) { | |
1971 | if (push_items <= 8) | |
1972 | return 1; | |
1973 | push_items -= 8; | |
1974 | } | |
1975 | } | |
1976 | } else | |
1977 | push_items = min(src_nritems - 8, push_items); | |
79f95c82 | 1978 | |
5f39d397 CM |
1979 | copy_extent_buffer(dst, src, |
1980 | btrfs_node_key_ptr_offset(dst_nritems), | |
1981 | btrfs_node_key_ptr_offset(0), | |
d397712b | 1982 | push_items * sizeof(struct btrfs_key_ptr)); |
5f39d397 | 1983 | |
bb803951 | 1984 | if (push_items < src_nritems) { |
5f39d397 CM |
1985 | memmove_extent_buffer(src, btrfs_node_key_ptr_offset(0), |
1986 | btrfs_node_key_ptr_offset(push_items), | |
1987 | (src_nritems - push_items) * | |
1988 | sizeof(struct btrfs_key_ptr)); | |
1989 | } | |
1990 | btrfs_set_header_nritems(src, src_nritems - push_items); | |
1991 | btrfs_set_header_nritems(dst, dst_nritems + push_items); | |
1992 | btrfs_mark_buffer_dirty(src); | |
1993 | btrfs_mark_buffer_dirty(dst); | |
31840ae1 | 1994 | |
79f95c82 CM |
1995 | return ret; |
1996 | } | |
1997 | ||
1998 | /* | |
1999 | * try to push data from one node into the next node right in the | |
2000 | * tree. | |
2001 | * | |
2002 | * returns 0 if some ptrs were pushed, < 0 if there was some horrible | |
2003 | * error, and > 0 if there was no room in the right hand block. | |
2004 | * | |
2005 | * this will only push up to 1/2 the contents of the left node over | |
2006 | */ | |
5f39d397 CM |
2007 | static int balance_node_right(struct btrfs_trans_handle *trans, |
2008 | struct btrfs_root *root, | |
2009 | struct extent_buffer *dst, | |
2010 | struct extent_buffer *src) | |
79f95c82 | 2011 | { |
79f95c82 CM |
2012 | int push_items = 0; |
2013 | int max_push; | |
2014 | int src_nritems; | |
2015 | int dst_nritems; | |
2016 | int ret = 0; | |
79f95c82 | 2017 | |
7bb86316 CM |
2018 | WARN_ON(btrfs_header_generation(src) != trans->transid); |
2019 | WARN_ON(btrfs_header_generation(dst) != trans->transid); | |
2020 | ||
5f39d397 CM |
2021 | src_nritems = btrfs_header_nritems(src); |
2022 | dst_nritems = btrfs_header_nritems(dst); | |
123abc88 | 2023 | push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems; |
d397712b | 2024 | if (push_items <= 0) |
79f95c82 | 2025 | return 1; |
bce4eae9 | 2026 | |
d397712b | 2027 | if (src_nritems < 4) |
bce4eae9 | 2028 | return 1; |
79f95c82 CM |
2029 | |
2030 | max_push = src_nritems / 2 + 1; | |
2031 | /* don't try to empty the node */ | |
d397712b | 2032 | if (max_push >= src_nritems) |
79f95c82 | 2033 | return 1; |
252c38f0 | 2034 | |
79f95c82 CM |
2035 | if (max_push < push_items) |
2036 | push_items = max_push; | |
2037 | ||
5f39d397 CM |
2038 | memmove_extent_buffer(dst, btrfs_node_key_ptr_offset(push_items), |
2039 | btrfs_node_key_ptr_offset(0), | |
2040 | (dst_nritems) * | |
2041 | sizeof(struct btrfs_key_ptr)); | |
d6025579 | 2042 | |
5f39d397 CM |
2043 | copy_extent_buffer(dst, src, |
2044 | btrfs_node_key_ptr_offset(0), | |
2045 | btrfs_node_key_ptr_offset(src_nritems - push_items), | |
d397712b | 2046 | push_items * sizeof(struct btrfs_key_ptr)); |
79f95c82 | 2047 | |
5f39d397 CM |
2048 | btrfs_set_header_nritems(src, src_nritems - push_items); |
2049 | btrfs_set_header_nritems(dst, dst_nritems + push_items); | |
79f95c82 | 2050 | |
5f39d397 CM |
2051 | btrfs_mark_buffer_dirty(src); |
2052 | btrfs_mark_buffer_dirty(dst); | |
31840ae1 | 2053 | |
aa5d6bed | 2054 | return ret; |
be0e5c09 CM |
2055 | } |
2056 | ||
97571fd0 CM |
2057 | /* |
2058 | * helper function to insert a new root level in the tree. | |
2059 | * A new node is allocated, and a single item is inserted to | |
2060 | * point to the existing root | |
aa5d6bed CM |
2061 | * |
2062 | * returns zero on success or < 0 on failure. | |
97571fd0 | 2063 | */ |
d397712b | 2064 | static noinline int insert_new_root(struct btrfs_trans_handle *trans, |
5f39d397 CM |
2065 | struct btrfs_root *root, |
2066 | struct btrfs_path *path, int level) | |
5c680ed6 | 2067 | { |
7bb86316 | 2068 | u64 lower_gen; |
5f39d397 CM |
2069 | struct extent_buffer *lower; |
2070 | struct extent_buffer *c; | |
925baedd | 2071 | struct extent_buffer *old; |
5f39d397 | 2072 | struct btrfs_disk_key lower_key; |
5c680ed6 CM |
2073 | |
2074 | BUG_ON(path->nodes[level]); | |
2075 | BUG_ON(path->nodes[level-1] != root->node); | |
2076 | ||
7bb86316 CM |
2077 | lower = path->nodes[level-1]; |
2078 | if (level == 1) | |
2079 | btrfs_item_key(lower, &lower_key, 0); | |
2080 | else | |
2081 | btrfs_node_key(lower, &lower_key, 0); | |
2082 | ||
31840ae1 | 2083 | c = btrfs_alloc_free_block(trans, root, root->nodesize, 0, |
5d4f98a2 | 2084 | root->root_key.objectid, &lower_key, |
ad3d81ba | 2085 | level, root->node->start, 0); |
5f39d397 CM |
2086 | if (IS_ERR(c)) |
2087 | return PTR_ERR(c); | |
925baedd | 2088 | |
f0486c68 YZ |
2089 | root_add_used(root, root->nodesize); |
2090 | ||
5d4f98a2 | 2091 | memset_extent_buffer(c, 0, 0, sizeof(struct btrfs_header)); |
5f39d397 CM |
2092 | btrfs_set_header_nritems(c, 1); |
2093 | btrfs_set_header_level(c, level); | |
db94535d | 2094 | btrfs_set_header_bytenr(c, c->start); |
5f39d397 | 2095 | btrfs_set_header_generation(c, trans->transid); |
5d4f98a2 | 2096 | btrfs_set_header_backref_rev(c, BTRFS_MIXED_BACKREF_REV); |
5f39d397 | 2097 | btrfs_set_header_owner(c, root->root_key.objectid); |
5f39d397 CM |
2098 | |
2099 | write_extent_buffer(c, root->fs_info->fsid, | |
2100 | (unsigned long)btrfs_header_fsid(c), | |
2101 | BTRFS_FSID_SIZE); | |
e17cade2 CM |
2102 | |
2103 | write_extent_buffer(c, root->fs_info->chunk_tree_uuid, | |
2104 | (unsigned long)btrfs_header_chunk_tree_uuid(c), | |
2105 | BTRFS_UUID_SIZE); | |
2106 | ||
5f39d397 | 2107 | btrfs_set_node_key(c, &lower_key, 0); |
db94535d | 2108 | btrfs_set_node_blockptr(c, 0, lower->start); |
7bb86316 | 2109 | lower_gen = btrfs_header_generation(lower); |
31840ae1 | 2110 | WARN_ON(lower_gen != trans->transid); |
7bb86316 CM |
2111 | |
2112 | btrfs_set_node_ptr_generation(c, 0, lower_gen); | |
d5719762 | 2113 | |
5f39d397 | 2114 | btrfs_mark_buffer_dirty(c); |
d5719762 | 2115 | |
925baedd CM |
2116 | spin_lock(&root->node_lock); |
2117 | old = root->node; | |
5f39d397 | 2118 | root->node = c; |
925baedd CM |
2119 | spin_unlock(&root->node_lock); |
2120 | ||
2121 | /* the super has an extra ref to root->node */ | |
2122 | free_extent_buffer(old); | |
2123 | ||
0b86a832 | 2124 | add_root_to_dirty_list(root); |
5f39d397 CM |
2125 | extent_buffer_get(c); |
2126 | path->nodes[level] = c; | |
925baedd | 2127 | path->locks[level] = 1; |
5c680ed6 CM |
2128 | path->slots[level] = 0; |
2129 | return 0; | |
2130 | } | |
2131 | ||
74123bd7 CM |
2132 | /* |
2133 | * worker function to insert a single pointer in a node. | |
2134 | * the node should have enough room for the pointer already | |
97571fd0 | 2135 | * |
74123bd7 CM |
2136 | * slot and level indicate where you want the key to go, and |
2137 | * blocknr is the block the key points to. | |
aa5d6bed CM |
2138 | * |
2139 | * returns zero on success and < 0 on any error | |
74123bd7 | 2140 | */ |
e089f05c CM |
2141 | static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root |
2142 | *root, struct btrfs_path *path, struct btrfs_disk_key | |
db94535d | 2143 | *key, u64 bytenr, int slot, int level) |
74123bd7 | 2144 | { |
5f39d397 | 2145 | struct extent_buffer *lower; |
74123bd7 | 2146 | int nritems; |
5c680ed6 CM |
2147 | |
2148 | BUG_ON(!path->nodes[level]); | |
f0486c68 | 2149 | btrfs_assert_tree_locked(path->nodes[level]); |
5f39d397 CM |
2150 | lower = path->nodes[level]; |
2151 | nritems = btrfs_header_nritems(lower); | |
c293498b | 2152 | BUG_ON(slot > nritems); |
123abc88 | 2153 | if (nritems == BTRFS_NODEPTRS_PER_BLOCK(root)) |
74123bd7 CM |
2154 | BUG(); |
2155 | if (slot != nritems) { | |
5f39d397 CM |
2156 | memmove_extent_buffer(lower, |
2157 | btrfs_node_key_ptr_offset(slot + 1), | |
2158 | btrfs_node_key_ptr_offset(slot), | |
d6025579 | 2159 | (nritems - slot) * sizeof(struct btrfs_key_ptr)); |
74123bd7 | 2160 | } |
5f39d397 | 2161 | btrfs_set_node_key(lower, key, slot); |
db94535d | 2162 | btrfs_set_node_blockptr(lower, slot, bytenr); |
74493f7a CM |
2163 | WARN_ON(trans->transid == 0); |
2164 | btrfs_set_node_ptr_generation(lower, slot, trans->transid); | |
5f39d397 CM |
2165 | btrfs_set_header_nritems(lower, nritems + 1); |
2166 | btrfs_mark_buffer_dirty(lower); | |
74123bd7 CM |
2167 | return 0; |
2168 | } | |
2169 | ||
97571fd0 CM |
2170 | /* |
2171 | * split the node at the specified level in path in two. | |
2172 | * The path is corrected to point to the appropriate node after the split | |
2173 | * | |
2174 | * Before splitting this tries to make some room in the node by pushing | |
2175 | * left and right, if either one works, it returns right away. | |
aa5d6bed CM |
2176 | * |
2177 | * returns 0 on success and < 0 on failure | |
97571fd0 | 2178 | */ |
e02119d5 CM |
2179 | static noinline int split_node(struct btrfs_trans_handle *trans, |
2180 | struct btrfs_root *root, | |
2181 | struct btrfs_path *path, int level) | |
be0e5c09 | 2182 | { |
5f39d397 CM |
2183 | struct extent_buffer *c; |
2184 | struct extent_buffer *split; | |
2185 | struct btrfs_disk_key disk_key; | |
be0e5c09 | 2186 | int mid; |
5c680ed6 | 2187 | int ret; |
aa5d6bed | 2188 | int wret; |
7518a238 | 2189 | u32 c_nritems; |
eb60ceac | 2190 | |
5f39d397 | 2191 | c = path->nodes[level]; |
7bb86316 | 2192 | WARN_ON(btrfs_header_generation(c) != trans->transid); |
5f39d397 | 2193 | if (c == root->node) { |
5c680ed6 | 2194 | /* trying to split the root, lets make a new one */ |
e089f05c | 2195 | ret = insert_new_root(trans, root, path, level + 1); |
5c680ed6 CM |
2196 | if (ret) |
2197 | return ret; | |
b3612421 | 2198 | } else { |
e66f709b | 2199 | ret = push_nodes_for_insert(trans, root, path, level); |
5f39d397 CM |
2200 | c = path->nodes[level]; |
2201 | if (!ret && btrfs_header_nritems(c) < | |
c448acf0 | 2202 | BTRFS_NODEPTRS_PER_BLOCK(root) - 3) |
e66f709b | 2203 | return 0; |
54aa1f4d CM |
2204 | if (ret < 0) |
2205 | return ret; | |
be0e5c09 | 2206 | } |
e66f709b | 2207 | |
5f39d397 | 2208 | c_nritems = btrfs_header_nritems(c); |
5d4f98a2 YZ |
2209 | mid = (c_nritems + 1) / 2; |
2210 | btrfs_node_key(c, &disk_key, mid); | |
7bb86316 | 2211 | |
5d4f98a2 | 2212 | split = btrfs_alloc_free_block(trans, root, root->nodesize, 0, |
31840ae1 | 2213 | root->root_key.objectid, |
5d4f98a2 | 2214 | &disk_key, level, c->start, 0); |
5f39d397 CM |
2215 | if (IS_ERR(split)) |
2216 | return PTR_ERR(split); | |
2217 | ||
f0486c68 YZ |
2218 | root_add_used(root, root->nodesize); |
2219 | ||
5d4f98a2 | 2220 | memset_extent_buffer(split, 0, 0, sizeof(struct btrfs_header)); |
5f39d397 | 2221 | btrfs_set_header_level(split, btrfs_header_level(c)); |
db94535d | 2222 | btrfs_set_header_bytenr(split, split->start); |
5f39d397 | 2223 | btrfs_set_header_generation(split, trans->transid); |
5d4f98a2 | 2224 | btrfs_set_header_backref_rev(split, BTRFS_MIXED_BACKREF_REV); |
5f39d397 CM |
2225 | btrfs_set_header_owner(split, root->root_key.objectid); |
2226 | write_extent_buffer(split, root->fs_info->fsid, | |
2227 | (unsigned long)btrfs_header_fsid(split), | |
2228 | BTRFS_FSID_SIZE); | |
e17cade2 CM |
2229 | write_extent_buffer(split, root->fs_info->chunk_tree_uuid, |
2230 | (unsigned long)btrfs_header_chunk_tree_uuid(split), | |
2231 | BTRFS_UUID_SIZE); | |
54aa1f4d | 2232 | |
5f39d397 CM |
2233 | |
2234 | copy_extent_buffer(split, c, | |
2235 | btrfs_node_key_ptr_offset(0), | |
2236 | btrfs_node_key_ptr_offset(mid), | |
2237 | (c_nritems - mid) * sizeof(struct btrfs_key_ptr)); | |
2238 | btrfs_set_header_nritems(split, c_nritems - mid); | |
2239 | btrfs_set_header_nritems(c, mid); | |
aa5d6bed CM |
2240 | ret = 0; |
2241 | ||
5f39d397 CM |
2242 | btrfs_mark_buffer_dirty(c); |
2243 | btrfs_mark_buffer_dirty(split); | |
2244 | ||
db94535d | 2245 | wret = insert_ptr(trans, root, path, &disk_key, split->start, |
5f39d397 | 2246 | path->slots[level + 1] + 1, |
123abc88 | 2247 | level + 1); |
aa5d6bed CM |
2248 | if (wret) |
2249 | ret = wret; | |
2250 | ||
5de08d7d | 2251 | if (path->slots[level] >= mid) { |
5c680ed6 | 2252 | path->slots[level] -= mid; |
925baedd | 2253 | btrfs_tree_unlock(c); |
5f39d397 CM |
2254 | free_extent_buffer(c); |
2255 | path->nodes[level] = split; | |
5c680ed6 CM |
2256 | path->slots[level + 1] += 1; |
2257 | } else { | |
925baedd | 2258 | btrfs_tree_unlock(split); |
5f39d397 | 2259 | free_extent_buffer(split); |
be0e5c09 | 2260 | } |
aa5d6bed | 2261 | return ret; |
be0e5c09 CM |
2262 | } |
2263 | ||
74123bd7 CM |
2264 | /* |
2265 | * how many bytes are required to store the items in a leaf. start | |
2266 | * and nr indicate which items in the leaf to check. This totals up the | |
2267 | * space used both by the item structs and the item data | |
2268 | */ | |
5f39d397 | 2269 | static int leaf_space_used(struct extent_buffer *l, int start, int nr) |
be0e5c09 CM |
2270 | { |
2271 | int data_len; | |
5f39d397 | 2272 | int nritems = btrfs_header_nritems(l); |
d4dbff95 | 2273 | int end = min(nritems, start + nr) - 1; |
be0e5c09 CM |
2274 | |
2275 | if (!nr) | |
2276 | return 0; | |
5f39d397 CM |
2277 | data_len = btrfs_item_end_nr(l, start); |
2278 | data_len = data_len - btrfs_item_offset_nr(l, end); | |
0783fcfc | 2279 | data_len += sizeof(struct btrfs_item) * nr; |
d4dbff95 | 2280 | WARN_ON(data_len < 0); |
be0e5c09 CM |
2281 | return data_len; |
2282 | } | |
2283 | ||
d4dbff95 CM |
2284 | /* |
2285 | * The space between the end of the leaf items and | |
2286 | * the start of the leaf data. IOW, how much room | |
2287 | * the leaf has left for both items and data | |
2288 | */ | |
d397712b | 2289 | noinline int btrfs_leaf_free_space(struct btrfs_root *root, |
e02119d5 | 2290 | struct extent_buffer *leaf) |
d4dbff95 | 2291 | { |
5f39d397 CM |
2292 | int nritems = btrfs_header_nritems(leaf); |
2293 | int ret; | |
2294 | ret = BTRFS_LEAF_DATA_SIZE(root) - leaf_space_used(leaf, 0, nritems); | |
2295 | if (ret < 0) { | |
d397712b CM |
2296 | printk(KERN_CRIT "leaf free space ret %d, leaf data size %lu, " |
2297 | "used %d nritems %d\n", | |
ae2f5411 | 2298 | ret, (unsigned long) BTRFS_LEAF_DATA_SIZE(root), |
5f39d397 CM |
2299 | leaf_space_used(leaf, 0, nritems), nritems); |
2300 | } | |
2301 | return ret; | |
d4dbff95 CM |
2302 | } |
2303 | ||
44871b1b CM |
2304 | static noinline int __push_leaf_right(struct btrfs_trans_handle *trans, |
2305 | struct btrfs_root *root, | |
2306 | struct btrfs_path *path, | |
2307 | int data_size, int empty, | |
2308 | struct extent_buffer *right, | |
2309 | int free_space, u32 left_nritems) | |
00ec4c51 | 2310 | { |
5f39d397 | 2311 | struct extent_buffer *left = path->nodes[0]; |
44871b1b | 2312 | struct extent_buffer *upper = path->nodes[1]; |
5f39d397 | 2313 | struct btrfs_disk_key disk_key; |
00ec4c51 | 2314 | int slot; |
34a38218 | 2315 | u32 i; |
00ec4c51 CM |
2316 | int push_space = 0; |
2317 | int push_items = 0; | |
0783fcfc | 2318 | struct btrfs_item *item; |
34a38218 | 2319 | u32 nr; |
7518a238 | 2320 | u32 right_nritems; |
5f39d397 | 2321 | u32 data_end; |
db94535d | 2322 | u32 this_item_size; |
00ec4c51 | 2323 | |
34a38218 CM |
2324 | if (empty) |
2325 | nr = 0; | |
2326 | else | |
2327 | nr = 1; | |
2328 | ||
31840ae1 | 2329 | if (path->slots[0] >= left_nritems) |
87b29b20 | 2330 | push_space += data_size; |
31840ae1 | 2331 | |
44871b1b | 2332 | slot = path->slots[1]; |
34a38218 CM |
2333 | i = left_nritems - 1; |
2334 | while (i >= nr) { | |
5f39d397 | 2335 | item = btrfs_item_nr(left, i); |
db94535d | 2336 | |
31840ae1 ZY |
2337 | if (!empty && push_items > 0) { |
2338 | if (path->slots[0] > i) | |
2339 | break; | |
2340 | if (path->slots[0] == i) { | |
2341 | int space = btrfs_leaf_free_space(root, left); | |
2342 | if (space + push_space * 2 > free_space) | |
2343 | break; | |
2344 | } | |
2345 | } | |
2346 | ||
00ec4c51 | 2347 | if (path->slots[0] == i) |
87b29b20 | 2348 | push_space += data_size; |
db94535d CM |
2349 | |
2350 | if (!left->map_token) { | |
2351 | map_extent_buffer(left, (unsigned long)item, | |
2352 | sizeof(struct btrfs_item), | |
2353 | &left->map_token, &left->kaddr, | |
2354 | &left->map_start, &left->map_len, | |
2355 | KM_USER1); | |
2356 | } | |
2357 | ||
2358 | this_item_size = btrfs_item_size(left, item); | |
2359 | if (this_item_size + sizeof(*item) + push_space > free_space) | |
00ec4c51 | 2360 | break; |
31840ae1 | 2361 | |
00ec4c51 | 2362 | push_items++; |
db94535d | 2363 | push_space += this_item_size + sizeof(*item); |
34a38218 CM |
2364 | if (i == 0) |
2365 | break; | |
2366 | i--; | |
db94535d CM |
2367 | } |
2368 | if (left->map_token) { | |
2369 | unmap_extent_buffer(left, left->map_token, KM_USER1); | |
2370 | left->map_token = NULL; | |
00ec4c51 | 2371 | } |
5f39d397 | 2372 | |
925baedd CM |
2373 | if (push_items == 0) |
2374 | goto out_unlock; | |
5f39d397 | 2375 | |
34a38218 | 2376 | if (!empty && push_items == left_nritems) |
a429e513 | 2377 | WARN_ON(1); |
5f39d397 | 2378 | |
00ec4c51 | 2379 | /* push left to right */ |
5f39d397 | 2380 | right_nritems = btrfs_header_nritems(right); |
34a38218 | 2381 | |
5f39d397 | 2382 | push_space = btrfs_item_end_nr(left, left_nritems - push_items); |
123abc88 | 2383 | push_space -= leaf_data_end(root, left); |
5f39d397 | 2384 | |
00ec4c51 | 2385 | /* make room in the right data area */ |
5f39d397 CM |
2386 | data_end = leaf_data_end(root, right); |
2387 | memmove_extent_buffer(right, | |
2388 | btrfs_leaf_data(right) + data_end - push_space, | |
2389 | btrfs_leaf_data(right) + data_end, | |
2390 | BTRFS_LEAF_DATA_SIZE(root) - data_end); | |
2391 | ||
00ec4c51 | 2392 | /* copy from the left data area */ |
5f39d397 | 2393 | copy_extent_buffer(right, left, btrfs_leaf_data(right) + |
d6025579 CM |
2394 | BTRFS_LEAF_DATA_SIZE(root) - push_space, |
2395 | btrfs_leaf_data(left) + leaf_data_end(root, left), | |
2396 | push_space); | |
5f39d397 CM |
2397 | |
2398 | memmove_extent_buffer(right, btrfs_item_nr_offset(push_items), | |
2399 | btrfs_item_nr_offset(0), | |
2400 | right_nritems * sizeof(struct btrfs_item)); | |
2401 | ||
00ec4c51 | 2402 | /* copy the items from left to right */ |
5f39d397 CM |
2403 | copy_extent_buffer(right, left, btrfs_item_nr_offset(0), |
2404 | btrfs_item_nr_offset(left_nritems - push_items), | |
2405 | push_items * sizeof(struct btrfs_item)); | |
00ec4c51 CM |
2406 | |
2407 | /* update the item pointers */ | |
7518a238 | 2408 | right_nritems += push_items; |
5f39d397 | 2409 | btrfs_set_header_nritems(right, right_nritems); |
123abc88 | 2410 | push_space = BTRFS_LEAF_DATA_SIZE(root); |
7518a238 | 2411 | for (i = 0; i < right_nritems; i++) { |
5f39d397 | 2412 | item = btrfs_item_nr(right, i); |
db94535d CM |
2413 | if (!right->map_token) { |
2414 | map_extent_buffer(right, (unsigned long)item, | |
2415 | sizeof(struct btrfs_item), | |
2416 | &right->map_token, &right->kaddr, | |
2417 | &right->map_start, &right->map_len, | |
2418 | KM_USER1); | |
2419 | } | |
2420 | push_space -= btrfs_item_size(right, item); | |
2421 | btrfs_set_item_offset(right, item, push_space); | |
2422 | } | |
2423 | ||
2424 | if (right->map_token) { | |
2425 | unmap_extent_buffer(right, right->map_token, KM_USER1); | |
2426 | right->map_token = NULL; | |
00ec4c51 | 2427 | } |
7518a238 | 2428 | left_nritems -= push_items; |
5f39d397 | 2429 | btrfs_set_header_nritems(left, left_nritems); |
00ec4c51 | 2430 | |
34a38218 CM |
2431 | if (left_nritems) |
2432 | btrfs_mark_buffer_dirty(left); | |
f0486c68 YZ |
2433 | else |
2434 | clean_tree_block(trans, root, left); | |
2435 | ||
5f39d397 | 2436 | btrfs_mark_buffer_dirty(right); |
a429e513 | 2437 | |
5f39d397 CM |
2438 | btrfs_item_key(right, &disk_key, 0); |
2439 | btrfs_set_node_key(upper, &disk_key, slot + 1); | |
d6025579 | 2440 | btrfs_mark_buffer_dirty(upper); |
02217ed2 | 2441 | |
00ec4c51 | 2442 | /* then fixup the leaf pointer in the path */ |
7518a238 CM |
2443 | if (path->slots[0] >= left_nritems) { |
2444 | path->slots[0] -= left_nritems; | |
925baedd CM |
2445 | if (btrfs_header_nritems(path->nodes[0]) == 0) |
2446 | clean_tree_block(trans, root, path->nodes[0]); | |
2447 | btrfs_tree_unlock(path->nodes[0]); | |
5f39d397 CM |
2448 | free_extent_buffer(path->nodes[0]); |
2449 | path->nodes[0] = right; | |
00ec4c51 CM |
2450 | path->slots[1] += 1; |
2451 | } else { | |
925baedd | 2452 | btrfs_tree_unlock(right); |
5f39d397 | 2453 | free_extent_buffer(right); |
00ec4c51 CM |
2454 | } |
2455 | return 0; | |
925baedd CM |
2456 | |
2457 | out_unlock: | |
2458 | btrfs_tree_unlock(right); | |
2459 | free_extent_buffer(right); | |
2460 | return 1; | |
00ec4c51 | 2461 | } |
925baedd | 2462 | |
44871b1b CM |
2463 | /* |
2464 | * push some data in the path leaf to the right, trying to free up at | |
2465 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
2466 | * | |
2467 | * returns 1 if the push failed because the other node didn't have enough | |
2468 | * room, 0 if everything worked out and < 0 if there were major errors. | |
2469 | */ | |
2470 | static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root | |
2471 | *root, struct btrfs_path *path, int data_size, | |
2472 | int empty) | |
2473 | { | |
2474 | struct extent_buffer *left = path->nodes[0]; | |
2475 | struct extent_buffer *right; | |
2476 | struct extent_buffer *upper; | |
2477 | int slot; | |
2478 | int free_space; | |
2479 | u32 left_nritems; | |
2480 | int ret; | |
2481 | ||
2482 | if (!path->nodes[1]) | |
2483 | return 1; | |
2484 | ||
2485 | slot = path->slots[1]; | |
2486 | upper = path->nodes[1]; | |
2487 | if (slot >= btrfs_header_nritems(upper) - 1) | |
2488 | return 1; | |
2489 | ||
2490 | btrfs_assert_tree_locked(path->nodes[1]); | |
2491 | ||
2492 | right = read_node_slot(root, upper, slot + 1); | |
2493 | btrfs_tree_lock(right); | |
2494 | btrfs_set_lock_blocking(right); | |
2495 | ||
2496 | free_space = btrfs_leaf_free_space(root, right); | |
2497 | if (free_space < data_size) | |
2498 | goto out_unlock; | |
2499 | ||
2500 | /* cow and double check */ | |
2501 | ret = btrfs_cow_block(trans, root, right, upper, | |
2502 | slot + 1, &right); | |
2503 | if (ret) | |
2504 | goto out_unlock; | |
2505 | ||
2506 | free_space = btrfs_leaf_free_space(root, right); | |
2507 | if (free_space < data_size) | |
2508 | goto out_unlock; | |
2509 | ||
2510 | left_nritems = btrfs_header_nritems(left); | |
2511 | if (left_nritems == 0) | |
2512 | goto out_unlock; | |
2513 | ||
2514 | return __push_leaf_right(trans, root, path, data_size, empty, | |
2515 | right, free_space, left_nritems); | |
2516 | out_unlock: | |
2517 | btrfs_tree_unlock(right); | |
2518 | free_extent_buffer(right); | |
2519 | return 1; | |
2520 | } | |
2521 | ||
74123bd7 CM |
2522 | /* |
2523 | * push some data in the path leaf to the left, trying to free up at | |
2524 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
2525 | */ | |
44871b1b CM |
2526 | static noinline int __push_leaf_left(struct btrfs_trans_handle *trans, |
2527 | struct btrfs_root *root, | |
2528 | struct btrfs_path *path, int data_size, | |
2529 | int empty, struct extent_buffer *left, | |
2530 | int free_space, int right_nritems) | |
be0e5c09 | 2531 | { |
5f39d397 CM |
2532 | struct btrfs_disk_key disk_key; |
2533 | struct extent_buffer *right = path->nodes[0]; | |
be0e5c09 CM |
2534 | int slot; |
2535 | int i; | |
be0e5c09 CM |
2536 | int push_space = 0; |
2537 | int push_items = 0; | |
0783fcfc | 2538 | struct btrfs_item *item; |
7518a238 | 2539 | u32 old_left_nritems; |
34a38218 | 2540 | u32 nr; |
aa5d6bed CM |
2541 | int ret = 0; |
2542 | int wret; | |
db94535d CM |
2543 | u32 this_item_size; |
2544 | u32 old_left_item_size; | |
be0e5c09 CM |
2545 | |
2546 | slot = path->slots[1]; | |
02217ed2 | 2547 | |
34a38218 CM |
2548 | if (empty) |
2549 | nr = right_nritems; | |
2550 | else | |
2551 | nr = right_nritems - 1; | |
2552 | ||
2553 | for (i = 0; i < nr; i++) { | |
5f39d397 | 2554 | item = btrfs_item_nr(right, i); |
db94535d CM |
2555 | if (!right->map_token) { |
2556 | map_extent_buffer(right, (unsigned long)item, | |
2557 | sizeof(struct btrfs_item), | |
2558 | &right->map_token, &right->kaddr, | |
2559 | &right->map_start, &right->map_len, | |
2560 | KM_USER1); | |
2561 | } | |
2562 | ||
31840ae1 ZY |
2563 | if (!empty && push_items > 0) { |
2564 | if (path->slots[0] < i) | |
2565 | break; | |
2566 | if (path->slots[0] == i) { | |
2567 | int space = btrfs_leaf_free_space(root, right); | |
2568 | if (space + push_space * 2 > free_space) | |
2569 | break; | |
2570 | } | |
2571 | } | |
2572 | ||
be0e5c09 | 2573 | if (path->slots[0] == i) |
87b29b20 | 2574 | push_space += data_size; |
db94535d CM |
2575 | |
2576 | this_item_size = btrfs_item_size(right, item); | |
2577 | if (this_item_size + sizeof(*item) + push_space > free_space) | |
be0e5c09 | 2578 | break; |
db94535d | 2579 | |
be0e5c09 | 2580 | push_items++; |
db94535d CM |
2581 | push_space += this_item_size + sizeof(*item); |
2582 | } | |
2583 | ||
2584 | if (right->map_token) { | |
2585 | unmap_extent_buffer(right, right->map_token, KM_USER1); | |
2586 | right->map_token = NULL; | |
be0e5c09 | 2587 | } |
db94535d | 2588 | |
be0e5c09 | 2589 | if (push_items == 0) { |
925baedd CM |
2590 | ret = 1; |
2591 | goto out; | |
be0e5c09 | 2592 | } |
34a38218 | 2593 | if (!empty && push_items == btrfs_header_nritems(right)) |
a429e513 | 2594 | WARN_ON(1); |
5f39d397 | 2595 | |
be0e5c09 | 2596 | /* push data from right to left */ |
5f39d397 CM |
2597 | copy_extent_buffer(left, right, |
2598 | btrfs_item_nr_offset(btrfs_header_nritems(left)), | |
2599 | btrfs_item_nr_offset(0), | |
2600 | push_items * sizeof(struct btrfs_item)); | |
2601 | ||
123abc88 | 2602 | push_space = BTRFS_LEAF_DATA_SIZE(root) - |
d397712b | 2603 | btrfs_item_offset_nr(right, push_items - 1); |
5f39d397 CM |
2604 | |
2605 | copy_extent_buffer(left, right, btrfs_leaf_data(left) + | |
d6025579 CM |
2606 | leaf_data_end(root, left) - push_space, |
2607 | btrfs_leaf_data(right) + | |
5f39d397 | 2608 | btrfs_item_offset_nr(right, push_items - 1), |
d6025579 | 2609 | push_space); |
5f39d397 | 2610 | old_left_nritems = btrfs_header_nritems(left); |
87b29b20 | 2611 | BUG_ON(old_left_nritems <= 0); |
eb60ceac | 2612 | |
db94535d | 2613 | old_left_item_size = btrfs_item_offset_nr(left, old_left_nritems - 1); |
0783fcfc | 2614 | for (i = old_left_nritems; i < old_left_nritems + push_items; i++) { |
5f39d397 | 2615 | u32 ioff; |
db94535d | 2616 | |
5f39d397 | 2617 | item = btrfs_item_nr(left, i); |
db94535d CM |
2618 | if (!left->map_token) { |
2619 | map_extent_buffer(left, (unsigned long)item, | |
2620 | sizeof(struct btrfs_item), | |
2621 | &left->map_token, &left->kaddr, | |
2622 | &left->map_start, &left->map_len, | |
2623 | KM_USER1); | |
2624 | } | |
2625 | ||
5f39d397 CM |
2626 | ioff = btrfs_item_offset(left, item); |
2627 | btrfs_set_item_offset(left, item, | |
db94535d | 2628 | ioff - (BTRFS_LEAF_DATA_SIZE(root) - old_left_item_size)); |
be0e5c09 | 2629 | } |
5f39d397 | 2630 | btrfs_set_header_nritems(left, old_left_nritems + push_items); |
db94535d CM |
2631 | if (left->map_token) { |
2632 | unmap_extent_buffer(left, left->map_token, KM_USER1); | |
2633 | left->map_token = NULL; | |
2634 | } | |
be0e5c09 CM |
2635 | |
2636 | /* fixup right node */ | |
34a38218 | 2637 | if (push_items > right_nritems) { |
d397712b CM |
2638 | printk(KERN_CRIT "push items %d nr %u\n", push_items, |
2639 | right_nritems); | |
34a38218 CM |
2640 | WARN_ON(1); |
2641 | } | |
2642 | ||
2643 | if (push_items < right_nritems) { | |
2644 | push_space = btrfs_item_offset_nr(right, push_items - 1) - | |
2645 | leaf_data_end(root, right); | |
2646 | memmove_extent_buffer(right, btrfs_leaf_data(right) + | |
2647 | BTRFS_LEAF_DATA_SIZE(root) - push_space, | |
2648 | btrfs_leaf_data(right) + | |
2649 | leaf_data_end(root, right), push_space); | |
2650 | ||
2651 | memmove_extent_buffer(right, btrfs_item_nr_offset(0), | |
5f39d397 CM |
2652 | btrfs_item_nr_offset(push_items), |
2653 | (btrfs_header_nritems(right) - push_items) * | |
2654 | sizeof(struct btrfs_item)); | |
34a38218 | 2655 | } |
eef1c494 Y |
2656 | right_nritems -= push_items; |
2657 | btrfs_set_header_nritems(right, right_nritems); | |
123abc88 | 2658 | push_space = BTRFS_LEAF_DATA_SIZE(root); |
5f39d397 CM |
2659 | for (i = 0; i < right_nritems; i++) { |
2660 | item = btrfs_item_nr(right, i); | |
db94535d CM |
2661 | |
2662 | if (!right->map_token) { | |
2663 | map_extent_buffer(right, (unsigned long)item, | |
2664 | sizeof(struct btrfs_item), | |
2665 | &right->map_token, &right->kaddr, | |
2666 | &right->map_start, &right->map_len, | |
2667 | KM_USER1); | |
2668 | } | |
2669 | ||
2670 | push_space = push_space - btrfs_item_size(right, item); | |
2671 | btrfs_set_item_offset(right, item, push_space); | |
2672 | } | |
2673 | if (right->map_token) { | |
2674 | unmap_extent_buffer(right, right->map_token, KM_USER1); | |
2675 | right->map_token = NULL; | |
be0e5c09 | 2676 | } |
eb60ceac | 2677 | |
5f39d397 | 2678 | btrfs_mark_buffer_dirty(left); |
34a38218 CM |
2679 | if (right_nritems) |
2680 | btrfs_mark_buffer_dirty(right); | |
f0486c68 YZ |
2681 | else |
2682 | clean_tree_block(trans, root, right); | |
098f59c2 | 2683 | |
5f39d397 CM |
2684 | btrfs_item_key(right, &disk_key, 0); |
2685 | wret = fixup_low_keys(trans, root, path, &disk_key, 1); | |
aa5d6bed CM |
2686 | if (wret) |
2687 | ret = wret; | |
be0e5c09 CM |
2688 | |
2689 | /* then fixup the leaf pointer in the path */ | |
2690 | if (path->slots[0] < push_items) { | |
2691 | path->slots[0] += old_left_nritems; | |
925baedd | 2692 | btrfs_tree_unlock(path->nodes[0]); |
5f39d397 CM |
2693 | free_extent_buffer(path->nodes[0]); |
2694 | path->nodes[0] = left; | |
be0e5c09 CM |
2695 | path->slots[1] -= 1; |
2696 | } else { | |
925baedd | 2697 | btrfs_tree_unlock(left); |
5f39d397 | 2698 | free_extent_buffer(left); |
be0e5c09 CM |
2699 | path->slots[0] -= push_items; |
2700 | } | |
eb60ceac | 2701 | BUG_ON(path->slots[0] < 0); |
aa5d6bed | 2702 | return ret; |
925baedd CM |
2703 | out: |
2704 | btrfs_tree_unlock(left); | |
2705 | free_extent_buffer(left); | |
2706 | return ret; | |
be0e5c09 CM |
2707 | } |
2708 | ||
44871b1b CM |
2709 | /* |
2710 | * push some data in the path leaf to the left, trying to free up at | |
2711 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
2712 | */ | |
2713 | static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root | |
2714 | *root, struct btrfs_path *path, int data_size, | |
2715 | int empty) | |
2716 | { | |
2717 | struct extent_buffer *right = path->nodes[0]; | |
2718 | struct extent_buffer *left; | |
2719 | int slot; | |
2720 | int free_space; | |
2721 | u32 right_nritems; | |
2722 | int ret = 0; | |
2723 | ||
2724 | slot = path->slots[1]; | |
2725 | if (slot == 0) | |
2726 | return 1; | |
2727 | if (!path->nodes[1]) | |
2728 | return 1; | |
2729 | ||
2730 | right_nritems = btrfs_header_nritems(right); | |
2731 | if (right_nritems == 0) | |
2732 | return 1; | |
2733 | ||
2734 | btrfs_assert_tree_locked(path->nodes[1]); | |
2735 | ||
2736 | left = read_node_slot(root, path->nodes[1], slot - 1); | |
2737 | btrfs_tree_lock(left); | |
2738 | btrfs_set_lock_blocking(left); | |
2739 | ||
2740 | free_space = btrfs_leaf_free_space(root, left); | |
2741 | if (free_space < data_size) { | |
2742 | ret = 1; | |
2743 | goto out; | |
2744 | } | |
2745 | ||
2746 | /* cow and double check */ | |
2747 | ret = btrfs_cow_block(trans, root, left, | |
2748 | path->nodes[1], slot - 1, &left); | |
2749 | if (ret) { | |
2750 | /* we hit -ENOSPC, but it isn't fatal here */ | |
2751 | ret = 1; | |
2752 | goto out; | |
2753 | } | |
2754 | ||
2755 | free_space = btrfs_leaf_free_space(root, left); | |
2756 | if (free_space < data_size) { | |
2757 | ret = 1; | |
2758 | goto out; | |
2759 | } | |
2760 | ||
2761 | return __push_leaf_left(trans, root, path, data_size, | |
2762 | empty, left, free_space, right_nritems); | |
2763 | out: | |
2764 | btrfs_tree_unlock(left); | |
2765 | free_extent_buffer(left); | |
2766 | return ret; | |
2767 | } | |
2768 | ||
2769 | /* | |
2770 | * split the path's leaf in two, making sure there is at least data_size | |
2771 | * available for the resulting leaf level of the path. | |
2772 | * | |
2773 | * returns 0 if all went well and < 0 on failure. | |
2774 | */ | |
2775 | static noinline int copy_for_split(struct btrfs_trans_handle *trans, | |
2776 | struct btrfs_root *root, | |
2777 | struct btrfs_path *path, | |
2778 | struct extent_buffer *l, | |
2779 | struct extent_buffer *right, | |
2780 | int slot, int mid, int nritems) | |
2781 | { | |
2782 | int data_copy_size; | |
2783 | int rt_data_off; | |
2784 | int i; | |
2785 | int ret = 0; | |
2786 | int wret; | |
2787 | struct btrfs_disk_key disk_key; | |
2788 | ||
2789 | nritems = nritems - mid; | |
2790 | btrfs_set_header_nritems(right, nritems); | |
2791 | data_copy_size = btrfs_item_end_nr(l, mid) - leaf_data_end(root, l); | |
2792 | ||
2793 | copy_extent_buffer(right, l, btrfs_item_nr_offset(0), | |
2794 | btrfs_item_nr_offset(mid), | |
2795 | nritems * sizeof(struct btrfs_item)); | |
2796 | ||
2797 | copy_extent_buffer(right, l, | |
2798 | btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) - | |
2799 | data_copy_size, btrfs_leaf_data(l) + | |
2800 | leaf_data_end(root, l), data_copy_size); | |
2801 | ||
2802 | rt_data_off = BTRFS_LEAF_DATA_SIZE(root) - | |
2803 | btrfs_item_end_nr(l, mid); | |
2804 | ||
2805 | for (i = 0; i < nritems; i++) { | |
2806 | struct btrfs_item *item = btrfs_item_nr(right, i); | |
2807 | u32 ioff; | |
2808 | ||
2809 | if (!right->map_token) { | |
2810 | map_extent_buffer(right, (unsigned long)item, | |
2811 | sizeof(struct btrfs_item), | |
2812 | &right->map_token, &right->kaddr, | |
2813 | &right->map_start, &right->map_len, | |
2814 | KM_USER1); | |
2815 | } | |
2816 | ||
2817 | ioff = btrfs_item_offset(right, item); | |
2818 | btrfs_set_item_offset(right, item, ioff + rt_data_off); | |
2819 | } | |
2820 | ||
2821 | if (right->map_token) { | |
2822 | unmap_extent_buffer(right, right->map_token, KM_USER1); | |
2823 | right->map_token = NULL; | |
2824 | } | |
2825 | ||
2826 | btrfs_set_header_nritems(l, mid); | |
2827 | ret = 0; | |
2828 | btrfs_item_key(right, &disk_key, 0); | |
2829 | wret = insert_ptr(trans, root, path, &disk_key, right->start, | |
2830 | path->slots[1] + 1, 1); | |
2831 | if (wret) | |
2832 | ret = wret; | |
2833 | ||
2834 | btrfs_mark_buffer_dirty(right); | |
2835 | btrfs_mark_buffer_dirty(l); | |
2836 | BUG_ON(path->slots[0] != slot); | |
2837 | ||
44871b1b CM |
2838 | if (mid <= slot) { |
2839 | btrfs_tree_unlock(path->nodes[0]); | |
2840 | free_extent_buffer(path->nodes[0]); | |
2841 | path->nodes[0] = right; | |
2842 | path->slots[0] -= mid; | |
2843 | path->slots[1] += 1; | |
2844 | } else { | |
2845 | btrfs_tree_unlock(right); | |
2846 | free_extent_buffer(right); | |
2847 | } | |
2848 | ||
2849 | BUG_ON(path->slots[0] < 0); | |
2850 | ||
2851 | return ret; | |
2852 | } | |
2853 | ||
74123bd7 CM |
2854 | /* |
2855 | * split the path's leaf in two, making sure there is at least data_size | |
2856 | * available for the resulting leaf level of the path. | |
aa5d6bed CM |
2857 | * |
2858 | * returns 0 if all went well and < 0 on failure. | |
74123bd7 | 2859 | */ |
e02119d5 CM |
2860 | static noinline int split_leaf(struct btrfs_trans_handle *trans, |
2861 | struct btrfs_root *root, | |
2862 | struct btrfs_key *ins_key, | |
2863 | struct btrfs_path *path, int data_size, | |
2864 | int extend) | |
be0e5c09 | 2865 | { |
5d4f98a2 | 2866 | struct btrfs_disk_key disk_key; |
5f39d397 | 2867 | struct extent_buffer *l; |
7518a238 | 2868 | u32 nritems; |
eb60ceac CM |
2869 | int mid; |
2870 | int slot; | |
5f39d397 | 2871 | struct extent_buffer *right; |
d4dbff95 | 2872 | int ret = 0; |
aa5d6bed | 2873 | int wret; |
5d4f98a2 | 2874 | int split; |
cc0c5538 | 2875 | int num_doubles = 0; |
aa5d6bed | 2876 | |
a5719521 YZ |
2877 | l = path->nodes[0]; |
2878 | slot = path->slots[0]; | |
2879 | if (extend && data_size + btrfs_item_size_nr(l, slot) + | |
2880 | sizeof(struct btrfs_item) > BTRFS_LEAF_DATA_SIZE(root)) | |
2881 | return -EOVERFLOW; | |
2882 | ||
40689478 | 2883 | /* first try to make some room by pushing left and right */ |
b3612421 | 2884 | if (data_size && ins_key->type != BTRFS_DIR_ITEM_KEY) { |
34a38218 | 2885 | wret = push_leaf_right(trans, root, path, data_size, 0); |
d397712b | 2886 | if (wret < 0) |
eaee50e8 | 2887 | return wret; |
3685f791 | 2888 | if (wret) { |
34a38218 | 2889 | wret = push_leaf_left(trans, root, path, data_size, 0); |
3685f791 CM |
2890 | if (wret < 0) |
2891 | return wret; | |
2892 | } | |
2893 | l = path->nodes[0]; | |
aa5d6bed | 2894 | |
3685f791 | 2895 | /* did the pushes work? */ |
87b29b20 | 2896 | if (btrfs_leaf_free_space(root, l) >= data_size) |
3685f791 | 2897 | return 0; |
3326d1b0 | 2898 | } |
aa5d6bed | 2899 | |
5c680ed6 | 2900 | if (!path->nodes[1]) { |
e089f05c | 2901 | ret = insert_new_root(trans, root, path, 1); |
5c680ed6 CM |
2902 | if (ret) |
2903 | return ret; | |
2904 | } | |
cc0c5538 | 2905 | again: |
5d4f98a2 | 2906 | split = 1; |
cc0c5538 | 2907 | l = path->nodes[0]; |
eb60ceac | 2908 | slot = path->slots[0]; |
5f39d397 | 2909 | nritems = btrfs_header_nritems(l); |
d397712b | 2910 | mid = (nritems + 1) / 2; |
54aa1f4d | 2911 | |
5d4f98a2 YZ |
2912 | if (mid <= slot) { |
2913 | if (nritems == 1 || | |
2914 | leaf_space_used(l, mid, nritems - mid) + data_size > | |
2915 | BTRFS_LEAF_DATA_SIZE(root)) { | |
2916 | if (slot >= nritems) { | |
2917 | split = 0; | |
2918 | } else { | |
2919 | mid = slot; | |
2920 | if (mid != nritems && | |
2921 | leaf_space_used(l, mid, nritems - mid) + | |
2922 | data_size > BTRFS_LEAF_DATA_SIZE(root)) { | |
2923 | split = 2; | |
2924 | } | |
2925 | } | |
2926 | } | |
2927 | } else { | |
2928 | if (leaf_space_used(l, 0, mid) + data_size > | |
2929 | BTRFS_LEAF_DATA_SIZE(root)) { | |
2930 | if (!extend && data_size && slot == 0) { | |
2931 | split = 0; | |
2932 | } else if ((extend || !data_size) && slot == 0) { | |
2933 | mid = 1; | |
2934 | } else { | |
2935 | mid = slot; | |
2936 | if (mid != nritems && | |
2937 | leaf_space_used(l, mid, nritems - mid) + | |
2938 | data_size > BTRFS_LEAF_DATA_SIZE(root)) { | |
2939 | split = 2 ; | |
2940 | } | |
2941 | } | |
2942 | } | |
2943 | } | |
2944 | ||
2945 | if (split == 0) | |
2946 | btrfs_cpu_key_to_disk(&disk_key, ins_key); | |
2947 | else | |
2948 | btrfs_item_key(l, &disk_key, mid); | |
2949 | ||
2950 | right = btrfs_alloc_free_block(trans, root, root->leafsize, 0, | |
31840ae1 | 2951 | root->root_key.objectid, |
5d4f98a2 | 2952 | &disk_key, 0, l->start, 0); |
f0486c68 | 2953 | if (IS_ERR(right)) |
5f39d397 | 2954 | return PTR_ERR(right); |
f0486c68 YZ |
2955 | |
2956 | root_add_used(root, root->leafsize); | |
5f39d397 CM |
2957 | |
2958 | memset_extent_buffer(right, 0, 0, sizeof(struct btrfs_header)); | |
db94535d | 2959 | btrfs_set_header_bytenr(right, right->start); |
5f39d397 | 2960 | btrfs_set_header_generation(right, trans->transid); |
5d4f98a2 | 2961 | btrfs_set_header_backref_rev(right, BTRFS_MIXED_BACKREF_REV); |
5f39d397 CM |
2962 | btrfs_set_header_owner(right, root->root_key.objectid); |
2963 | btrfs_set_header_level(right, 0); | |
2964 | write_extent_buffer(right, root->fs_info->fsid, | |
2965 | (unsigned long)btrfs_header_fsid(right), | |
2966 | BTRFS_FSID_SIZE); | |
e17cade2 CM |
2967 | |
2968 | write_extent_buffer(right, root->fs_info->chunk_tree_uuid, | |
2969 | (unsigned long)btrfs_header_chunk_tree_uuid(right), | |
2970 | BTRFS_UUID_SIZE); | |
44871b1b | 2971 | |
5d4f98a2 YZ |
2972 | if (split == 0) { |
2973 | if (mid <= slot) { | |
2974 | btrfs_set_header_nritems(right, 0); | |
2975 | wret = insert_ptr(trans, root, path, | |
2976 | &disk_key, right->start, | |
2977 | path->slots[1] + 1, 1); | |
2978 | if (wret) | |
2979 | ret = wret; | |
925baedd | 2980 | |
5d4f98a2 YZ |
2981 | btrfs_tree_unlock(path->nodes[0]); |
2982 | free_extent_buffer(path->nodes[0]); | |
2983 | path->nodes[0] = right; | |
2984 | path->slots[0] = 0; | |
2985 | path->slots[1] += 1; | |
2986 | } else { | |
2987 | btrfs_set_header_nritems(right, 0); | |
2988 | wret = insert_ptr(trans, root, path, | |
2989 | &disk_key, | |
2990 | right->start, | |
2991 | path->slots[1], 1); | |
2992 | if (wret) | |
2993 | ret = wret; | |
2994 | btrfs_tree_unlock(path->nodes[0]); | |
2995 | free_extent_buffer(path->nodes[0]); | |
2996 | path->nodes[0] = right; | |
2997 | path->slots[0] = 0; | |
2998 | if (path->slots[1] == 0) { | |
2999 | wret = fixup_low_keys(trans, root, | |
3000 | path, &disk_key, 1); | |
d4dbff95 CM |
3001 | if (wret) |
3002 | ret = wret; | |
5ee78ac7 | 3003 | } |
d4dbff95 | 3004 | } |
5d4f98a2 YZ |
3005 | btrfs_mark_buffer_dirty(right); |
3006 | return ret; | |
d4dbff95 | 3007 | } |
74123bd7 | 3008 | |
44871b1b | 3009 | ret = copy_for_split(trans, root, path, l, right, slot, mid, nritems); |
31840ae1 ZY |
3010 | BUG_ON(ret); |
3011 | ||
5d4f98a2 | 3012 | if (split == 2) { |
cc0c5538 CM |
3013 | BUG_ON(num_doubles != 0); |
3014 | num_doubles++; | |
3015 | goto again; | |
a429e513 | 3016 | } |
44871b1b | 3017 | |
be0e5c09 CM |
3018 | return ret; |
3019 | } | |
3020 | ||
ad48fd75 YZ |
3021 | static noinline int setup_leaf_for_split(struct btrfs_trans_handle *trans, |
3022 | struct btrfs_root *root, | |
3023 | struct btrfs_path *path, int ins_len) | |
459931ec | 3024 | { |
ad48fd75 | 3025 | struct btrfs_key key; |
459931ec | 3026 | struct extent_buffer *leaf; |
ad48fd75 YZ |
3027 | struct btrfs_file_extent_item *fi; |
3028 | u64 extent_len = 0; | |
3029 | u32 item_size; | |
3030 | int ret; | |
459931ec CM |
3031 | |
3032 | leaf = path->nodes[0]; | |
ad48fd75 YZ |
3033 | btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
3034 | ||
3035 | BUG_ON(key.type != BTRFS_EXTENT_DATA_KEY && | |
3036 | key.type != BTRFS_EXTENT_CSUM_KEY); | |
3037 | ||
3038 | if (btrfs_leaf_free_space(root, leaf) >= ins_len) | |
3039 | return 0; | |
459931ec CM |
3040 | |
3041 | item_size = btrfs_item_size_nr(leaf, path->slots[0]); | |
ad48fd75 YZ |
3042 | if (key.type == BTRFS_EXTENT_DATA_KEY) { |
3043 | fi = btrfs_item_ptr(leaf, path->slots[0], | |
3044 | struct btrfs_file_extent_item); | |
3045 | extent_len = btrfs_file_extent_num_bytes(leaf, fi); | |
3046 | } | |
459931ec CM |
3047 | btrfs_release_path(root, path); |
3048 | ||
459931ec | 3049 | path->keep_locks = 1; |
ad48fd75 YZ |
3050 | path->search_for_split = 1; |
3051 | ret = btrfs_search_slot(trans, root, &key, path, 0, 1); | |
459931ec | 3052 | path->search_for_split = 0; |
ad48fd75 YZ |
3053 | if (ret < 0) |
3054 | goto err; | |
459931ec | 3055 | |
ad48fd75 YZ |
3056 | ret = -EAGAIN; |
3057 | leaf = path->nodes[0]; | |
459931ec | 3058 | /* if our item isn't there or got smaller, return now */ |
ad48fd75 YZ |
3059 | if (ret > 0 || item_size != btrfs_item_size_nr(leaf, path->slots[0])) |
3060 | goto err; | |
3061 | ||
109f6aef CM |
3062 | /* the leaf has changed, it now has room. return now */ |
3063 | if (btrfs_leaf_free_space(root, path->nodes[0]) >= ins_len) | |
3064 | goto err; | |
3065 | ||
ad48fd75 YZ |
3066 | if (key.type == BTRFS_EXTENT_DATA_KEY) { |
3067 | fi = btrfs_item_ptr(leaf, path->slots[0], | |
3068 | struct btrfs_file_extent_item); | |
3069 | if (extent_len != btrfs_file_extent_num_bytes(leaf, fi)) | |
3070 | goto err; | |
459931ec CM |
3071 | } |
3072 | ||
b9473439 | 3073 | btrfs_set_path_blocking(path); |
ad48fd75 | 3074 | ret = split_leaf(trans, root, &key, path, ins_len, 1); |
f0486c68 YZ |
3075 | if (ret) |
3076 | goto err; | |
459931ec | 3077 | |
ad48fd75 | 3078 | path->keep_locks = 0; |
b9473439 | 3079 | btrfs_unlock_up_safe(path, 1); |
ad48fd75 YZ |
3080 | return 0; |
3081 | err: | |
3082 | path->keep_locks = 0; | |
3083 | return ret; | |
3084 | } | |
3085 | ||
3086 | static noinline int split_item(struct btrfs_trans_handle *trans, | |
3087 | struct btrfs_root *root, | |
3088 | struct btrfs_path *path, | |
3089 | struct btrfs_key *new_key, | |
3090 | unsigned long split_offset) | |
3091 | { | |
3092 | struct extent_buffer *leaf; | |
3093 | struct btrfs_item *item; | |
3094 | struct btrfs_item *new_item; | |
3095 | int slot; | |
3096 | char *buf; | |
3097 | u32 nritems; | |
3098 | u32 item_size; | |
3099 | u32 orig_offset; | |
3100 | struct btrfs_disk_key disk_key; | |
3101 | ||
b9473439 CM |
3102 | leaf = path->nodes[0]; |
3103 | BUG_ON(btrfs_leaf_free_space(root, leaf) < sizeof(struct btrfs_item)); | |
3104 | ||
b4ce94de CM |
3105 | btrfs_set_path_blocking(path); |
3106 | ||
459931ec CM |
3107 | item = btrfs_item_nr(leaf, path->slots[0]); |
3108 | orig_offset = btrfs_item_offset(leaf, item); | |
3109 | item_size = btrfs_item_size(leaf, item); | |
3110 | ||
459931ec | 3111 | buf = kmalloc(item_size, GFP_NOFS); |
ad48fd75 YZ |
3112 | if (!buf) |
3113 | return -ENOMEM; | |
3114 | ||
459931ec CM |
3115 | read_extent_buffer(leaf, buf, btrfs_item_ptr_offset(leaf, |
3116 | path->slots[0]), item_size); | |
459931ec | 3117 | |
ad48fd75 | 3118 | slot = path->slots[0] + 1; |
459931ec | 3119 | nritems = btrfs_header_nritems(leaf); |
459931ec CM |
3120 | if (slot != nritems) { |
3121 | /* shift the items */ | |
3122 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + 1), | |
ad48fd75 YZ |
3123 | btrfs_item_nr_offset(slot), |
3124 | (nritems - slot) * sizeof(struct btrfs_item)); | |
459931ec CM |
3125 | } |
3126 | ||
3127 | btrfs_cpu_key_to_disk(&disk_key, new_key); | |
3128 | btrfs_set_item_key(leaf, &disk_key, slot); | |
3129 | ||
3130 | new_item = btrfs_item_nr(leaf, slot); | |
3131 | ||
3132 | btrfs_set_item_offset(leaf, new_item, orig_offset); | |
3133 | btrfs_set_item_size(leaf, new_item, item_size - split_offset); | |
3134 | ||
3135 | btrfs_set_item_offset(leaf, item, | |
3136 | orig_offset + item_size - split_offset); | |
3137 | btrfs_set_item_size(leaf, item, split_offset); | |
3138 | ||
3139 | btrfs_set_header_nritems(leaf, nritems + 1); | |
3140 | ||
3141 | /* write the data for the start of the original item */ | |
3142 | write_extent_buffer(leaf, buf, | |
3143 | btrfs_item_ptr_offset(leaf, path->slots[0]), | |
3144 | split_offset); | |
3145 | ||
3146 | /* write the data for the new item */ | |
3147 | write_extent_buffer(leaf, buf + split_offset, | |
3148 | btrfs_item_ptr_offset(leaf, slot), | |
3149 | item_size - split_offset); | |
3150 | btrfs_mark_buffer_dirty(leaf); | |
3151 | ||
ad48fd75 | 3152 | BUG_ON(btrfs_leaf_free_space(root, leaf) < 0); |
459931ec | 3153 | kfree(buf); |
ad48fd75 YZ |
3154 | return 0; |
3155 | } | |
3156 | ||
3157 | /* | |
3158 | * This function splits a single item into two items, | |
3159 | * giving 'new_key' to the new item and splitting the | |
3160 | * old one at split_offset (from the start of the item). | |
3161 | * | |
3162 | * The path may be released by this operation. After | |
3163 | * the split, the path is pointing to the old item. The | |
3164 | * new item is going to be in the same node as the old one. | |
3165 | * | |
3166 | * Note, the item being split must be smaller enough to live alone on | |
3167 | * a tree block with room for one extra struct btrfs_item | |
3168 | * | |
3169 | * This allows us to split the item in place, keeping a lock on the | |
3170 | * leaf the entire time. | |
3171 | */ | |
3172 | int btrfs_split_item(struct btrfs_trans_handle *trans, | |
3173 | struct btrfs_root *root, | |
3174 | struct btrfs_path *path, | |
3175 | struct btrfs_key *new_key, | |
3176 | unsigned long split_offset) | |
3177 | { | |
3178 | int ret; | |
3179 | ret = setup_leaf_for_split(trans, root, path, | |
3180 | sizeof(struct btrfs_item)); | |
3181 | if (ret) | |
3182 | return ret; | |
3183 | ||
3184 | ret = split_item(trans, root, path, new_key, split_offset); | |
459931ec CM |
3185 | return ret; |
3186 | } | |
3187 | ||
ad48fd75 YZ |
3188 | /* |
3189 | * This function duplicate a item, giving 'new_key' to the new item. | |
3190 | * It guarantees both items live in the same tree leaf and the new item | |
3191 | * is contiguous with the original item. | |
3192 | * | |
3193 | * This allows us to split file extent in place, keeping a lock on the | |
3194 | * leaf the entire time. | |
3195 | */ | |
3196 | int btrfs_duplicate_item(struct btrfs_trans_handle *trans, | |
3197 | struct btrfs_root *root, | |
3198 | struct btrfs_path *path, | |
3199 | struct btrfs_key *new_key) | |
3200 | { | |
3201 | struct extent_buffer *leaf; | |
3202 | int ret; | |
3203 | u32 item_size; | |
3204 | ||
3205 | leaf = path->nodes[0]; | |
3206 | item_size = btrfs_item_size_nr(leaf, path->slots[0]); | |
3207 | ret = setup_leaf_for_split(trans, root, path, | |
3208 | item_size + sizeof(struct btrfs_item)); | |
3209 | if (ret) | |
3210 | return ret; | |
3211 | ||
3212 | path->slots[0]++; | |
3213 | ret = setup_items_for_insert(trans, root, path, new_key, &item_size, | |
3214 | item_size, item_size + | |
3215 | sizeof(struct btrfs_item), 1); | |
3216 | BUG_ON(ret); | |
3217 | ||
3218 | leaf = path->nodes[0]; | |
3219 | memcpy_extent_buffer(leaf, | |
3220 | btrfs_item_ptr_offset(leaf, path->slots[0]), | |
3221 | btrfs_item_ptr_offset(leaf, path->slots[0] - 1), | |
3222 | item_size); | |
3223 | return 0; | |
3224 | } | |
3225 | ||
d352ac68 CM |
3226 | /* |
3227 | * make the item pointed to by the path smaller. new_size indicates | |
3228 | * how small to make it, and from_end tells us if we just chop bytes | |
3229 | * off the end of the item or if we shift the item to chop bytes off | |
3230 | * the front. | |
3231 | */ | |
b18c6685 CM |
3232 | int btrfs_truncate_item(struct btrfs_trans_handle *trans, |
3233 | struct btrfs_root *root, | |
3234 | struct btrfs_path *path, | |
179e29e4 | 3235 | u32 new_size, int from_end) |
b18c6685 CM |
3236 | { |
3237 | int ret = 0; | |
3238 | int slot; | |
3239 | int slot_orig; | |
5f39d397 CM |
3240 | struct extent_buffer *leaf; |
3241 | struct btrfs_item *item; | |
b18c6685 CM |
3242 | u32 nritems; |
3243 | unsigned int data_end; | |
3244 | unsigned int old_data_start; | |
3245 | unsigned int old_size; | |
3246 | unsigned int size_diff; | |
3247 | int i; | |
3248 | ||
3249 | slot_orig = path->slots[0]; | |
5f39d397 | 3250 | leaf = path->nodes[0]; |
179e29e4 CM |
3251 | slot = path->slots[0]; |
3252 | ||
3253 | old_size = btrfs_item_size_nr(leaf, slot); | |
3254 | if (old_size == new_size) | |
3255 | return 0; | |
b18c6685 | 3256 | |
5f39d397 | 3257 | nritems = btrfs_header_nritems(leaf); |
b18c6685 CM |
3258 | data_end = leaf_data_end(root, leaf); |
3259 | ||
5f39d397 | 3260 | old_data_start = btrfs_item_offset_nr(leaf, slot); |
179e29e4 | 3261 | |
b18c6685 CM |
3262 | size_diff = old_size - new_size; |
3263 | ||
3264 | BUG_ON(slot < 0); | |
3265 | BUG_ON(slot >= nritems); | |
3266 | ||
3267 | /* | |
3268 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
3269 | */ | |
3270 | /* first correct the data pointers */ | |
3271 | for (i = slot; i < nritems; i++) { | |
5f39d397 CM |
3272 | u32 ioff; |
3273 | item = btrfs_item_nr(leaf, i); | |
db94535d CM |
3274 | |
3275 | if (!leaf->map_token) { | |
3276 | map_extent_buffer(leaf, (unsigned long)item, | |
3277 | sizeof(struct btrfs_item), | |
3278 | &leaf->map_token, &leaf->kaddr, | |
3279 | &leaf->map_start, &leaf->map_len, | |
3280 | KM_USER1); | |
3281 | } | |
3282 | ||
5f39d397 CM |
3283 | ioff = btrfs_item_offset(leaf, item); |
3284 | btrfs_set_item_offset(leaf, item, ioff + size_diff); | |
b18c6685 | 3285 | } |
db94535d CM |
3286 | |
3287 | if (leaf->map_token) { | |
3288 | unmap_extent_buffer(leaf, leaf->map_token, KM_USER1); | |
3289 | leaf->map_token = NULL; | |
3290 | } | |
3291 | ||
b18c6685 | 3292 | /* shift the data */ |
179e29e4 CM |
3293 | if (from_end) { |
3294 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + | |
3295 | data_end + size_diff, btrfs_leaf_data(leaf) + | |
3296 | data_end, old_data_start + new_size - data_end); | |
3297 | } else { | |
3298 | struct btrfs_disk_key disk_key; | |
3299 | u64 offset; | |
3300 | ||
3301 | btrfs_item_key(leaf, &disk_key, slot); | |
3302 | ||
3303 | if (btrfs_disk_key_type(&disk_key) == BTRFS_EXTENT_DATA_KEY) { | |
3304 | unsigned long ptr; | |
3305 | struct btrfs_file_extent_item *fi; | |
3306 | ||
3307 | fi = btrfs_item_ptr(leaf, slot, | |
3308 | struct btrfs_file_extent_item); | |
3309 | fi = (struct btrfs_file_extent_item *)( | |
3310 | (unsigned long)fi - size_diff); | |
3311 | ||
3312 | if (btrfs_file_extent_type(leaf, fi) == | |
3313 | BTRFS_FILE_EXTENT_INLINE) { | |
3314 | ptr = btrfs_item_ptr_offset(leaf, slot); | |
3315 | memmove_extent_buffer(leaf, ptr, | |
d397712b CM |
3316 | (unsigned long)fi, |
3317 | offsetof(struct btrfs_file_extent_item, | |
179e29e4 CM |
3318 | disk_bytenr)); |
3319 | } | |
3320 | } | |
3321 | ||
3322 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + | |
3323 | data_end + size_diff, btrfs_leaf_data(leaf) + | |
3324 | data_end, old_data_start - data_end); | |
3325 | ||
3326 | offset = btrfs_disk_key_offset(&disk_key); | |
3327 | btrfs_set_disk_key_offset(&disk_key, offset + size_diff); | |
3328 | btrfs_set_item_key(leaf, &disk_key, slot); | |
3329 | if (slot == 0) | |
3330 | fixup_low_keys(trans, root, path, &disk_key, 1); | |
3331 | } | |
5f39d397 CM |
3332 | |
3333 | item = btrfs_item_nr(leaf, slot); | |
3334 | btrfs_set_item_size(leaf, item, new_size); | |
3335 | btrfs_mark_buffer_dirty(leaf); | |
b18c6685 CM |
3336 | |
3337 | ret = 0; | |
5f39d397 CM |
3338 | if (btrfs_leaf_free_space(root, leaf) < 0) { |
3339 | btrfs_print_leaf(root, leaf); | |
b18c6685 | 3340 | BUG(); |
5f39d397 | 3341 | } |
b18c6685 CM |
3342 | return ret; |
3343 | } | |
3344 | ||
d352ac68 CM |
3345 | /* |
3346 | * make the item pointed to by the path bigger, data_size is the new size. | |
3347 | */ | |
5f39d397 CM |
3348 | int btrfs_extend_item(struct btrfs_trans_handle *trans, |
3349 | struct btrfs_root *root, struct btrfs_path *path, | |
3350 | u32 data_size) | |
6567e837 CM |
3351 | { |
3352 | int ret = 0; | |
3353 | int slot; | |
3354 | int slot_orig; | |
5f39d397 CM |
3355 | struct extent_buffer *leaf; |
3356 | struct btrfs_item *item; | |
6567e837 CM |
3357 | u32 nritems; |
3358 | unsigned int data_end; | |
3359 | unsigned int old_data; | |
3360 | unsigned int old_size; | |
3361 | int i; | |
3362 | ||
3363 | slot_orig = path->slots[0]; | |
5f39d397 | 3364 | leaf = path->nodes[0]; |
6567e837 | 3365 | |
5f39d397 | 3366 | nritems = btrfs_header_nritems(leaf); |
6567e837 CM |
3367 | data_end = leaf_data_end(root, leaf); |
3368 | ||
5f39d397 CM |
3369 | if (btrfs_leaf_free_space(root, leaf) < data_size) { |
3370 | btrfs_print_leaf(root, leaf); | |
6567e837 | 3371 | BUG(); |
5f39d397 | 3372 | } |
6567e837 | 3373 | slot = path->slots[0]; |
5f39d397 | 3374 | old_data = btrfs_item_end_nr(leaf, slot); |
6567e837 CM |
3375 | |
3376 | BUG_ON(slot < 0); | |
3326d1b0 CM |
3377 | if (slot >= nritems) { |
3378 | btrfs_print_leaf(root, leaf); | |
d397712b CM |
3379 | printk(KERN_CRIT "slot %d too large, nritems %d\n", |
3380 | slot, nritems); | |
3326d1b0 CM |
3381 | BUG_ON(1); |
3382 | } | |
6567e837 CM |
3383 | |
3384 | /* | |
3385 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
3386 | */ | |
3387 | /* first correct the data pointers */ | |
3388 | for (i = slot; i < nritems; i++) { | |
5f39d397 CM |
3389 | u32 ioff; |
3390 | item = btrfs_item_nr(leaf, i); | |
db94535d CM |
3391 | |
3392 | if (!leaf->map_token) { | |
3393 | map_extent_buffer(leaf, (unsigned long)item, | |
3394 | sizeof(struct btrfs_item), | |
3395 | &leaf->map_token, &leaf->kaddr, | |
3396 | &leaf->map_start, &leaf->map_len, | |
3397 | KM_USER1); | |
3398 | } | |
5f39d397 CM |
3399 | ioff = btrfs_item_offset(leaf, item); |
3400 | btrfs_set_item_offset(leaf, item, ioff - data_size); | |
6567e837 | 3401 | } |
5f39d397 | 3402 | |
db94535d CM |
3403 | if (leaf->map_token) { |
3404 | unmap_extent_buffer(leaf, leaf->map_token, KM_USER1); | |
3405 | leaf->map_token = NULL; | |
3406 | } | |
3407 | ||
6567e837 | 3408 | /* shift the data */ |
5f39d397 | 3409 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + |
6567e837 CM |
3410 | data_end - data_size, btrfs_leaf_data(leaf) + |
3411 | data_end, old_data - data_end); | |
5f39d397 | 3412 | |
6567e837 | 3413 | data_end = old_data; |
5f39d397 CM |
3414 | old_size = btrfs_item_size_nr(leaf, slot); |
3415 | item = btrfs_item_nr(leaf, slot); | |
3416 | btrfs_set_item_size(leaf, item, old_size + data_size); | |
3417 | btrfs_mark_buffer_dirty(leaf); | |
6567e837 CM |
3418 | |
3419 | ret = 0; | |
5f39d397 CM |
3420 | if (btrfs_leaf_free_space(root, leaf) < 0) { |
3421 | btrfs_print_leaf(root, leaf); | |
6567e837 | 3422 | BUG(); |
5f39d397 | 3423 | } |
6567e837 CM |
3424 | return ret; |
3425 | } | |
3426 | ||
f3465ca4 JB |
3427 | /* |
3428 | * Given a key and some data, insert items into the tree. | |
3429 | * This does all the path init required, making room in the tree if needed. | |
3430 | * Returns the number of keys that were inserted. | |
3431 | */ | |
3432 | int btrfs_insert_some_items(struct btrfs_trans_handle *trans, | |
3433 | struct btrfs_root *root, | |
3434 | struct btrfs_path *path, | |
3435 | struct btrfs_key *cpu_key, u32 *data_size, | |
3436 | int nr) | |
3437 | { | |
3438 | struct extent_buffer *leaf; | |
3439 | struct btrfs_item *item; | |
3440 | int ret = 0; | |
3441 | int slot; | |
f3465ca4 JB |
3442 | int i; |
3443 | u32 nritems; | |
3444 | u32 total_data = 0; | |
3445 | u32 total_size = 0; | |
3446 | unsigned int data_end; | |
3447 | struct btrfs_disk_key disk_key; | |
3448 | struct btrfs_key found_key; | |
3449 | ||
87b29b20 YZ |
3450 | for (i = 0; i < nr; i++) { |
3451 | if (total_size + data_size[i] + sizeof(struct btrfs_item) > | |
3452 | BTRFS_LEAF_DATA_SIZE(root)) { | |
3453 | break; | |
3454 | nr = i; | |
3455 | } | |
f3465ca4 | 3456 | total_data += data_size[i]; |
87b29b20 YZ |
3457 | total_size += data_size[i] + sizeof(struct btrfs_item); |
3458 | } | |
3459 | BUG_ON(nr == 0); | |
f3465ca4 | 3460 | |
f3465ca4 JB |
3461 | ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1); |
3462 | if (ret == 0) | |
3463 | return -EEXIST; | |
3464 | if (ret < 0) | |
3465 | goto out; | |
3466 | ||
f3465ca4 JB |
3467 | leaf = path->nodes[0]; |
3468 | ||
3469 | nritems = btrfs_header_nritems(leaf); | |
3470 | data_end = leaf_data_end(root, leaf); | |
3471 | ||
3472 | if (btrfs_leaf_free_space(root, leaf) < total_size) { | |
3473 | for (i = nr; i >= 0; i--) { | |
3474 | total_data -= data_size[i]; | |
3475 | total_size -= data_size[i] + sizeof(struct btrfs_item); | |
3476 | if (total_size < btrfs_leaf_free_space(root, leaf)) | |
3477 | break; | |
3478 | } | |
3479 | nr = i; | |
3480 | } | |
3481 | ||
3482 | slot = path->slots[0]; | |
3483 | BUG_ON(slot < 0); | |
3484 | ||
3485 | if (slot != nritems) { | |
3486 | unsigned int old_data = btrfs_item_end_nr(leaf, slot); | |
3487 | ||
3488 | item = btrfs_item_nr(leaf, slot); | |
3489 | btrfs_item_key_to_cpu(leaf, &found_key, slot); | |
3490 | ||
3491 | /* figure out how many keys we can insert in here */ | |
3492 | total_data = data_size[0]; | |
3493 | for (i = 1; i < nr; i++) { | |
5d4f98a2 | 3494 | if (btrfs_comp_cpu_keys(&found_key, cpu_key + i) <= 0) |
f3465ca4 JB |
3495 | break; |
3496 | total_data += data_size[i]; | |
3497 | } | |
3498 | nr = i; | |
3499 | ||
3500 | if (old_data < data_end) { | |
3501 | btrfs_print_leaf(root, leaf); | |
d397712b | 3502 | printk(KERN_CRIT "slot %d old_data %d data_end %d\n", |
f3465ca4 JB |
3503 | slot, old_data, data_end); |
3504 | BUG_ON(1); | |
3505 | } | |
3506 | /* | |
3507 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
3508 | */ | |
3509 | /* first correct the data pointers */ | |
3510 | WARN_ON(leaf->map_token); | |
3511 | for (i = slot; i < nritems; i++) { | |
3512 | u32 ioff; | |
3513 | ||
3514 | item = btrfs_item_nr(leaf, i); | |
3515 | if (!leaf->map_token) { | |
3516 | map_extent_buffer(leaf, (unsigned long)item, | |
3517 | sizeof(struct btrfs_item), | |
3518 | &leaf->map_token, &leaf->kaddr, | |
3519 | &leaf->map_start, &leaf->map_len, | |
3520 | KM_USER1); | |
3521 | } | |
3522 | ||
3523 | ioff = btrfs_item_offset(leaf, item); | |
3524 | btrfs_set_item_offset(leaf, item, ioff - total_data); | |
3525 | } | |
3526 | if (leaf->map_token) { | |
3527 | unmap_extent_buffer(leaf, leaf->map_token, KM_USER1); | |
3528 | leaf->map_token = NULL; | |
3529 | } | |
3530 | ||
3531 | /* shift the items */ | |
3532 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr), | |
3533 | btrfs_item_nr_offset(slot), | |
3534 | (nritems - slot) * sizeof(struct btrfs_item)); | |
3535 | ||
3536 | /* shift the data */ | |
3537 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + | |
3538 | data_end - total_data, btrfs_leaf_data(leaf) + | |
3539 | data_end, old_data - data_end); | |
3540 | data_end = old_data; | |
3541 | } else { | |
3542 | /* | |
3543 | * this sucks but it has to be done, if we are inserting at | |
3544 | * the end of the leaf only insert 1 of the items, since we | |
3545 | * have no way of knowing whats on the next leaf and we'd have | |
3546 | * to drop our current locks to figure it out | |
3547 | */ | |
3548 | nr = 1; | |
3549 | } | |
3550 | ||
3551 | /* setup the item for the new data */ | |
3552 | for (i = 0; i < nr; i++) { | |
3553 | btrfs_cpu_key_to_disk(&disk_key, cpu_key + i); | |
3554 | btrfs_set_item_key(leaf, &disk_key, slot + i); | |
3555 | item = btrfs_item_nr(leaf, slot + i); | |
3556 | btrfs_set_item_offset(leaf, item, data_end - data_size[i]); | |
3557 | data_end -= data_size[i]; | |
3558 | btrfs_set_item_size(leaf, item, data_size[i]); | |
3559 | } | |
3560 | btrfs_set_header_nritems(leaf, nritems + nr); | |
3561 | btrfs_mark_buffer_dirty(leaf); | |
3562 | ||
3563 | ret = 0; | |
3564 | if (slot == 0) { | |
3565 | btrfs_cpu_key_to_disk(&disk_key, cpu_key); | |
3566 | ret = fixup_low_keys(trans, root, path, &disk_key, 1); | |
3567 | } | |
3568 | ||
3569 | if (btrfs_leaf_free_space(root, leaf) < 0) { | |
3570 | btrfs_print_leaf(root, leaf); | |
3571 | BUG(); | |
3572 | } | |
3573 | out: | |
3574 | if (!ret) | |
3575 | ret = nr; | |
3576 | return ret; | |
3577 | } | |
3578 | ||
74123bd7 | 3579 | /* |
44871b1b CM |
3580 | * this is a helper for btrfs_insert_empty_items, the main goal here is |
3581 | * to save stack depth by doing the bulk of the work in a function | |
3582 | * that doesn't call btrfs_search_slot | |
74123bd7 | 3583 | */ |
44871b1b CM |
3584 | static noinline_for_stack int |
3585 | setup_items_for_insert(struct btrfs_trans_handle *trans, | |
3586 | struct btrfs_root *root, struct btrfs_path *path, | |
3587 | struct btrfs_key *cpu_key, u32 *data_size, | |
3588 | u32 total_data, u32 total_size, int nr) | |
be0e5c09 | 3589 | { |
5f39d397 | 3590 | struct btrfs_item *item; |
9c58309d | 3591 | int i; |
7518a238 | 3592 | u32 nritems; |
be0e5c09 | 3593 | unsigned int data_end; |
e2fa7227 | 3594 | struct btrfs_disk_key disk_key; |
44871b1b CM |
3595 | int ret; |
3596 | struct extent_buffer *leaf; | |
3597 | int slot; | |
e2fa7227 | 3598 | |
5f39d397 | 3599 | leaf = path->nodes[0]; |
44871b1b | 3600 | slot = path->slots[0]; |
74123bd7 | 3601 | |
5f39d397 | 3602 | nritems = btrfs_header_nritems(leaf); |
123abc88 | 3603 | data_end = leaf_data_end(root, leaf); |
eb60ceac | 3604 | |
f25956cc | 3605 | if (btrfs_leaf_free_space(root, leaf) < total_size) { |
3326d1b0 | 3606 | btrfs_print_leaf(root, leaf); |
d397712b | 3607 | printk(KERN_CRIT "not enough freespace need %u have %d\n", |
9c58309d | 3608 | total_size, btrfs_leaf_free_space(root, leaf)); |
be0e5c09 | 3609 | BUG(); |
d4dbff95 | 3610 | } |
5f39d397 | 3611 | |
be0e5c09 | 3612 | if (slot != nritems) { |
5f39d397 | 3613 | unsigned int old_data = btrfs_item_end_nr(leaf, slot); |
be0e5c09 | 3614 | |
5f39d397 CM |
3615 | if (old_data < data_end) { |
3616 | btrfs_print_leaf(root, leaf); | |
d397712b | 3617 | printk(KERN_CRIT "slot %d old_data %d data_end %d\n", |
5f39d397 CM |
3618 | slot, old_data, data_end); |
3619 | BUG_ON(1); | |
3620 | } | |
be0e5c09 CM |
3621 | /* |
3622 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
3623 | */ | |
3624 | /* first correct the data pointers */ | |
db94535d | 3625 | WARN_ON(leaf->map_token); |
0783fcfc | 3626 | for (i = slot; i < nritems; i++) { |
5f39d397 | 3627 | u32 ioff; |
db94535d | 3628 | |
5f39d397 | 3629 | item = btrfs_item_nr(leaf, i); |
db94535d CM |
3630 | if (!leaf->map_token) { |
3631 | map_extent_buffer(leaf, (unsigned long)item, | |
3632 | sizeof(struct btrfs_item), | |
3633 | &leaf->map_token, &leaf->kaddr, | |
3634 | &leaf->map_start, &leaf->map_len, | |
3635 | KM_USER1); | |
3636 | } | |
3637 | ||
5f39d397 | 3638 | ioff = btrfs_item_offset(leaf, item); |
9c58309d | 3639 | btrfs_set_item_offset(leaf, item, ioff - total_data); |
0783fcfc | 3640 | } |
db94535d CM |
3641 | if (leaf->map_token) { |
3642 | unmap_extent_buffer(leaf, leaf->map_token, KM_USER1); | |
3643 | leaf->map_token = NULL; | |
3644 | } | |
be0e5c09 CM |
3645 | |
3646 | /* shift the items */ | |
9c58309d | 3647 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr), |
5f39d397 | 3648 | btrfs_item_nr_offset(slot), |
d6025579 | 3649 | (nritems - slot) * sizeof(struct btrfs_item)); |
be0e5c09 CM |
3650 | |
3651 | /* shift the data */ | |
5f39d397 | 3652 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + |
9c58309d | 3653 | data_end - total_data, btrfs_leaf_data(leaf) + |
d6025579 | 3654 | data_end, old_data - data_end); |
be0e5c09 CM |
3655 | data_end = old_data; |
3656 | } | |
5f39d397 | 3657 | |
62e2749e | 3658 | /* setup the item for the new data */ |
9c58309d CM |
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 | } | |
44871b1b | 3667 | |
9c58309d | 3668 | btrfs_set_header_nritems(leaf, nritems + nr); |
aa5d6bed CM |
3669 | |
3670 | ret = 0; | |
5a01a2e3 | 3671 | if (slot == 0) { |
44871b1b | 3672 | struct btrfs_disk_key disk_key; |
5a01a2e3 | 3673 | btrfs_cpu_key_to_disk(&disk_key, cpu_key); |
e089f05c | 3674 | ret = fixup_low_keys(trans, root, path, &disk_key, 1); |
5a01a2e3 | 3675 | } |
b9473439 CM |
3676 | btrfs_unlock_up_safe(path, 1); |
3677 | btrfs_mark_buffer_dirty(leaf); | |
aa5d6bed | 3678 | |
5f39d397 CM |
3679 | if (btrfs_leaf_free_space(root, leaf) < 0) { |
3680 | btrfs_print_leaf(root, leaf); | |
be0e5c09 | 3681 | BUG(); |
5f39d397 | 3682 | } |
44871b1b CM |
3683 | return ret; |
3684 | } | |
3685 | ||
3686 | /* | |
3687 | * Given a key and some data, insert items into the tree. | |
3688 | * This does all the path init required, making room in the tree if needed. | |
3689 | */ | |
3690 | int btrfs_insert_empty_items(struct btrfs_trans_handle *trans, | |
3691 | struct btrfs_root *root, | |
3692 | struct btrfs_path *path, | |
3693 | struct btrfs_key *cpu_key, u32 *data_size, | |
3694 | int nr) | |
3695 | { | |
3696 | struct extent_buffer *leaf; | |
3697 | int ret = 0; | |
3698 | int slot; | |
3699 | int i; | |
3700 | u32 total_size = 0; | |
3701 | u32 total_data = 0; | |
3702 | ||
3703 | for (i = 0; i < nr; i++) | |
3704 | total_data += data_size[i]; | |
3705 | ||
3706 | total_size = total_data + (nr * sizeof(struct btrfs_item)); | |
3707 | ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1); | |
3708 | if (ret == 0) | |
3709 | return -EEXIST; | |
3710 | if (ret < 0) | |
3711 | goto out; | |
3712 | ||
3713 | leaf = path->nodes[0]; | |
3714 | slot = path->slots[0]; | |
3715 | BUG_ON(slot < 0); | |
3716 | ||
3717 | ret = setup_items_for_insert(trans, root, path, cpu_key, data_size, | |
3718 | total_data, total_size, nr); | |
3719 | ||
ed2ff2cb | 3720 | out: |
62e2749e CM |
3721 | return ret; |
3722 | } | |
3723 | ||
3724 | /* | |
3725 | * Given a key and some data, insert an item into the tree. | |
3726 | * This does all the path init required, making room in the tree if needed. | |
3727 | */ | |
e089f05c CM |
3728 | int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root |
3729 | *root, struct btrfs_key *cpu_key, void *data, u32 | |
3730 | data_size) | |
62e2749e CM |
3731 | { |
3732 | int ret = 0; | |
2c90e5d6 | 3733 | struct btrfs_path *path; |
5f39d397 CM |
3734 | struct extent_buffer *leaf; |
3735 | unsigned long ptr; | |
62e2749e | 3736 | |
2c90e5d6 CM |
3737 | path = btrfs_alloc_path(); |
3738 | BUG_ON(!path); | |
2c90e5d6 | 3739 | ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size); |
62e2749e | 3740 | if (!ret) { |
5f39d397 CM |
3741 | leaf = path->nodes[0]; |
3742 | ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); | |
3743 | write_extent_buffer(leaf, data, ptr, data_size); | |
3744 | btrfs_mark_buffer_dirty(leaf); | |
62e2749e | 3745 | } |
2c90e5d6 | 3746 | btrfs_free_path(path); |
aa5d6bed | 3747 | return ret; |
be0e5c09 CM |
3748 | } |
3749 | ||
74123bd7 | 3750 | /* |
5de08d7d | 3751 | * delete the pointer from a given node. |
74123bd7 | 3752 | * |
d352ac68 CM |
3753 | * the tree should have been previously balanced so the deletion does not |
3754 | * empty a node. | |
74123bd7 | 3755 | */ |
e089f05c CM |
3756 | static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
3757 | struct btrfs_path *path, int level, int slot) | |
be0e5c09 | 3758 | { |
5f39d397 | 3759 | struct extent_buffer *parent = path->nodes[level]; |
7518a238 | 3760 | u32 nritems; |
aa5d6bed | 3761 | int ret = 0; |
bb803951 | 3762 | int wret; |
be0e5c09 | 3763 | |
5f39d397 | 3764 | nritems = btrfs_header_nritems(parent); |
d397712b | 3765 | if (slot != nritems - 1) { |
5f39d397 CM |
3766 | memmove_extent_buffer(parent, |
3767 | btrfs_node_key_ptr_offset(slot), | |
3768 | btrfs_node_key_ptr_offset(slot + 1), | |
d6025579 CM |
3769 | sizeof(struct btrfs_key_ptr) * |
3770 | (nritems - slot - 1)); | |
bb803951 | 3771 | } |
7518a238 | 3772 | nritems--; |
5f39d397 | 3773 | btrfs_set_header_nritems(parent, nritems); |
7518a238 | 3774 | if (nritems == 0 && parent == root->node) { |
5f39d397 | 3775 | BUG_ON(btrfs_header_level(root->node) != 1); |
bb803951 | 3776 | /* just turn the root into a leaf and break */ |
5f39d397 | 3777 | btrfs_set_header_level(root->node, 0); |
bb803951 | 3778 | } else if (slot == 0) { |
5f39d397 CM |
3779 | struct btrfs_disk_key disk_key; |
3780 | ||
3781 | btrfs_node_key(parent, &disk_key, 0); | |
3782 | wret = fixup_low_keys(trans, root, path, &disk_key, level + 1); | |
0f70abe2 CM |
3783 | if (wret) |
3784 | ret = wret; | |
be0e5c09 | 3785 | } |
d6025579 | 3786 | btrfs_mark_buffer_dirty(parent); |
aa5d6bed | 3787 | return ret; |
be0e5c09 CM |
3788 | } |
3789 | ||
323ac95b CM |
3790 | /* |
3791 | * a helper function to delete the leaf pointed to by path->slots[1] and | |
5d4f98a2 | 3792 | * path->nodes[1]. |
323ac95b CM |
3793 | * |
3794 | * This deletes the pointer in path->nodes[1] and frees the leaf | |
3795 | * block extent. zero is returned if it all worked out, < 0 otherwise. | |
3796 | * | |
3797 | * The path must have already been setup for deleting the leaf, including | |
3798 | * all the proper balancing. path->nodes[1] must be locked. | |
3799 | */ | |
5d4f98a2 YZ |
3800 | static noinline int btrfs_del_leaf(struct btrfs_trans_handle *trans, |
3801 | struct btrfs_root *root, | |
3802 | struct btrfs_path *path, | |
3803 | struct extent_buffer *leaf) | |
323ac95b CM |
3804 | { |
3805 | int ret; | |
323ac95b | 3806 | |
5d4f98a2 | 3807 | WARN_ON(btrfs_header_generation(leaf) != trans->transid); |
323ac95b CM |
3808 | ret = del_ptr(trans, root, path, 1, path->slots[1]); |
3809 | if (ret) | |
3810 | return ret; | |
3811 | ||
4d081c41 CM |
3812 | /* |
3813 | * btrfs_free_extent is expensive, we want to make sure we | |
3814 | * aren't holding any locks when we call it | |
3815 | */ | |
3816 | btrfs_unlock_up_safe(path, 0); | |
3817 | ||
f0486c68 YZ |
3818 | root_sub_used(root, leaf->len); |
3819 | ||
3820 | btrfs_free_tree_block(trans, root, leaf, 0, 1); | |
3821 | return 0; | |
323ac95b | 3822 | } |
74123bd7 CM |
3823 | /* |
3824 | * delete the item at the leaf level in path. If that empties | |
3825 | * the leaf, remove it from the tree | |
3826 | */ | |
85e21bac CM |
3827 | int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
3828 | struct btrfs_path *path, int slot, int nr) | |
be0e5c09 | 3829 | { |
5f39d397 CM |
3830 | struct extent_buffer *leaf; |
3831 | struct btrfs_item *item; | |
85e21bac CM |
3832 | int last_off; |
3833 | int dsize = 0; | |
aa5d6bed CM |
3834 | int ret = 0; |
3835 | int wret; | |
85e21bac | 3836 | int i; |
7518a238 | 3837 | u32 nritems; |
be0e5c09 | 3838 | |
5f39d397 | 3839 | leaf = path->nodes[0]; |
85e21bac CM |
3840 | last_off = btrfs_item_offset_nr(leaf, slot + nr - 1); |
3841 | ||
3842 | for (i = 0; i < nr; i++) | |
3843 | dsize += btrfs_item_size_nr(leaf, slot + i); | |
3844 | ||
5f39d397 | 3845 | nritems = btrfs_header_nritems(leaf); |
be0e5c09 | 3846 | |
85e21bac | 3847 | if (slot + nr != nritems) { |
123abc88 | 3848 | int data_end = leaf_data_end(root, leaf); |
5f39d397 CM |
3849 | |
3850 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + | |
d6025579 CM |
3851 | data_end + dsize, |
3852 | btrfs_leaf_data(leaf) + data_end, | |
85e21bac | 3853 | last_off - data_end); |
5f39d397 | 3854 | |
85e21bac | 3855 | for (i = slot + nr; i < nritems; i++) { |
5f39d397 | 3856 | u32 ioff; |
db94535d | 3857 | |
5f39d397 | 3858 | item = btrfs_item_nr(leaf, i); |
db94535d CM |
3859 | if (!leaf->map_token) { |
3860 | map_extent_buffer(leaf, (unsigned long)item, | |
3861 | sizeof(struct btrfs_item), | |
3862 | &leaf->map_token, &leaf->kaddr, | |
3863 | &leaf->map_start, &leaf->map_len, | |
3864 | KM_USER1); | |
3865 | } | |
5f39d397 CM |
3866 | ioff = btrfs_item_offset(leaf, item); |
3867 | btrfs_set_item_offset(leaf, item, ioff + dsize); | |
0783fcfc | 3868 | } |
db94535d CM |
3869 | |
3870 | if (leaf->map_token) { | |
3871 | unmap_extent_buffer(leaf, leaf->map_token, KM_USER1); | |
3872 | leaf->map_token = NULL; | |
3873 | } | |
3874 | ||
5f39d397 | 3875 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot), |
85e21bac | 3876 | btrfs_item_nr_offset(slot + nr), |
d6025579 | 3877 | sizeof(struct btrfs_item) * |
85e21bac | 3878 | (nritems - slot - nr)); |
be0e5c09 | 3879 | } |
85e21bac CM |
3880 | btrfs_set_header_nritems(leaf, nritems - nr); |
3881 | nritems -= nr; | |
5f39d397 | 3882 | |
74123bd7 | 3883 | /* delete the leaf if we've emptied it */ |
7518a238 | 3884 | if (nritems == 0) { |
5f39d397 CM |
3885 | if (leaf == root->node) { |
3886 | btrfs_set_header_level(leaf, 0); | |
9a8dd150 | 3887 | } else { |
f0486c68 YZ |
3888 | btrfs_set_path_blocking(path); |
3889 | clean_tree_block(trans, root, leaf); | |
5d4f98a2 | 3890 | ret = btrfs_del_leaf(trans, root, path, leaf); |
323ac95b | 3891 | BUG_ON(ret); |
9a8dd150 | 3892 | } |
be0e5c09 | 3893 | } else { |
7518a238 | 3894 | int used = leaf_space_used(leaf, 0, nritems); |
aa5d6bed | 3895 | if (slot == 0) { |
5f39d397 CM |
3896 | struct btrfs_disk_key disk_key; |
3897 | ||
3898 | btrfs_item_key(leaf, &disk_key, 0); | |
e089f05c | 3899 | wret = fixup_low_keys(trans, root, path, |
5f39d397 | 3900 | &disk_key, 1); |
aa5d6bed CM |
3901 | if (wret) |
3902 | ret = wret; | |
3903 | } | |
aa5d6bed | 3904 | |
74123bd7 | 3905 | /* delete the leaf if it is mostly empty */ |
d717aa1d | 3906 | if (used < BTRFS_LEAF_DATA_SIZE(root) / 3) { |
be0e5c09 CM |
3907 | /* push_leaf_left fixes the path. |
3908 | * make sure the path still points to our leaf | |
3909 | * for possible call to del_ptr below | |
3910 | */ | |
4920c9ac | 3911 | slot = path->slots[1]; |
5f39d397 CM |
3912 | extent_buffer_get(leaf); |
3913 | ||
b9473439 | 3914 | btrfs_set_path_blocking(path); |
85e21bac | 3915 | wret = push_leaf_left(trans, root, path, 1, 1); |
54aa1f4d | 3916 | if (wret < 0 && wret != -ENOSPC) |
aa5d6bed | 3917 | ret = wret; |
5f39d397 CM |
3918 | |
3919 | if (path->nodes[0] == leaf && | |
3920 | btrfs_header_nritems(leaf)) { | |
85e21bac | 3921 | wret = push_leaf_right(trans, root, path, 1, 1); |
54aa1f4d | 3922 | if (wret < 0 && wret != -ENOSPC) |
aa5d6bed CM |
3923 | ret = wret; |
3924 | } | |
5f39d397 CM |
3925 | |
3926 | if (btrfs_header_nritems(leaf) == 0) { | |
323ac95b | 3927 | path->slots[1] = slot; |
5d4f98a2 | 3928 | ret = btrfs_del_leaf(trans, root, path, leaf); |
323ac95b | 3929 | BUG_ON(ret); |
5f39d397 | 3930 | free_extent_buffer(leaf); |
5de08d7d | 3931 | } else { |
925baedd CM |
3932 | /* if we're still in the path, make sure |
3933 | * we're dirty. Otherwise, one of the | |
3934 | * push_leaf functions must have already | |
3935 | * dirtied this buffer | |
3936 | */ | |
3937 | if (path->nodes[0] == leaf) | |
3938 | btrfs_mark_buffer_dirty(leaf); | |
5f39d397 | 3939 | free_extent_buffer(leaf); |
be0e5c09 | 3940 | } |
d5719762 | 3941 | } else { |
5f39d397 | 3942 | btrfs_mark_buffer_dirty(leaf); |
be0e5c09 CM |
3943 | } |
3944 | } | |
aa5d6bed | 3945 | return ret; |
be0e5c09 CM |
3946 | } |
3947 | ||
7bb86316 | 3948 | /* |
925baedd | 3949 | * search the tree again to find a leaf with lesser keys |
7bb86316 CM |
3950 | * returns 0 if it found something or 1 if there are no lesser leaves. |
3951 | * returns < 0 on io errors. | |
d352ac68 CM |
3952 | * |
3953 | * This may release the path, and so you may lose any locks held at the | |
3954 | * time you call it. | |
7bb86316 CM |
3955 | */ |
3956 | int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path) | |
3957 | { | |
925baedd CM |
3958 | struct btrfs_key key; |
3959 | struct btrfs_disk_key found_key; | |
3960 | int ret; | |
7bb86316 | 3961 | |
925baedd | 3962 | btrfs_item_key_to_cpu(path->nodes[0], &key, 0); |
7bb86316 | 3963 | |
925baedd CM |
3964 | if (key.offset > 0) |
3965 | key.offset--; | |
3966 | else if (key.type > 0) | |
3967 | key.type--; | |
3968 | else if (key.objectid > 0) | |
3969 | key.objectid--; | |
3970 | else | |
3971 | return 1; | |
7bb86316 | 3972 | |
925baedd CM |
3973 | btrfs_release_path(root, path); |
3974 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); | |
3975 | if (ret < 0) | |
3976 | return ret; | |
3977 | btrfs_item_key(path->nodes[0], &found_key, 0); | |
3978 | ret = comp_keys(&found_key, &key); | |
3979 | if (ret < 0) | |
3980 | return 0; | |
3981 | return 1; | |
7bb86316 CM |
3982 | } |
3983 | ||
3f157a2f CM |
3984 | /* |
3985 | * A helper function to walk down the tree starting at min_key, and looking | |
3986 | * for nodes or leaves that are either in cache or have a minimum | |
d352ac68 | 3987 | * transaction id. This is used by the btree defrag code, and tree logging |
3f157a2f CM |
3988 | * |
3989 | * This does not cow, but it does stuff the starting key it finds back | |
3990 | * into min_key, so you can call btrfs_search_slot with cow=1 on the | |
3991 | * key and get a writable path. | |
3992 | * | |
3993 | * This does lock as it descends, and path->keep_locks should be set | |
3994 | * to 1 by the caller. | |
3995 | * | |
3996 | * This honors path->lowest_level to prevent descent past a given level | |
3997 | * of the tree. | |
3998 | * | |
d352ac68 CM |
3999 | * min_trans indicates the oldest transaction that you are interested |
4000 | * in walking through. Any nodes or leaves older than min_trans are | |
4001 | * skipped over (without reading them). | |
4002 | * | |
3f157a2f CM |
4003 | * returns zero if something useful was found, < 0 on error and 1 if there |
4004 | * was nothing in the tree that matched the search criteria. | |
4005 | */ | |
4006 | int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key, | |
e02119d5 | 4007 | struct btrfs_key *max_key, |
3f157a2f CM |
4008 | struct btrfs_path *path, int cache_only, |
4009 | u64 min_trans) | |
4010 | { | |
4011 | struct extent_buffer *cur; | |
4012 | struct btrfs_key found_key; | |
4013 | int slot; | |
9652480b | 4014 | int sret; |
3f157a2f CM |
4015 | u32 nritems; |
4016 | int level; | |
4017 | int ret = 1; | |
4018 | ||
934d375b | 4019 | WARN_ON(!path->keep_locks); |
3f157a2f CM |
4020 | again: |
4021 | cur = btrfs_lock_root_node(root); | |
4022 | level = btrfs_header_level(cur); | |
e02119d5 | 4023 | WARN_ON(path->nodes[level]); |
3f157a2f CM |
4024 | path->nodes[level] = cur; |
4025 | path->locks[level] = 1; | |
4026 | ||
4027 | if (btrfs_header_generation(cur) < min_trans) { | |
4028 | ret = 1; | |
4029 | goto out; | |
4030 | } | |
d397712b | 4031 | while (1) { |
3f157a2f CM |
4032 | nritems = btrfs_header_nritems(cur); |
4033 | level = btrfs_header_level(cur); | |
9652480b | 4034 | sret = bin_search(cur, min_key, level, &slot); |
3f157a2f | 4035 | |
323ac95b CM |
4036 | /* at the lowest level, we're done, setup the path and exit */ |
4037 | if (level == path->lowest_level) { | |
e02119d5 CM |
4038 | if (slot >= nritems) |
4039 | goto find_next_key; | |
3f157a2f CM |
4040 | ret = 0; |
4041 | path->slots[level] = slot; | |
4042 | btrfs_item_key_to_cpu(cur, &found_key, slot); | |
4043 | goto out; | |
4044 | } | |
9652480b Y |
4045 | if (sret && slot > 0) |
4046 | slot--; | |
3f157a2f CM |
4047 | /* |
4048 | * check this node pointer against the cache_only and | |
4049 | * min_trans parameters. If it isn't in cache or is too | |
4050 | * old, skip to the next one. | |
4051 | */ | |
d397712b | 4052 | while (slot < nritems) { |
3f157a2f CM |
4053 | u64 blockptr; |
4054 | u64 gen; | |
4055 | struct extent_buffer *tmp; | |
e02119d5 CM |
4056 | struct btrfs_disk_key disk_key; |
4057 | ||
3f157a2f CM |
4058 | blockptr = btrfs_node_blockptr(cur, slot); |
4059 | gen = btrfs_node_ptr_generation(cur, slot); | |
4060 | if (gen < min_trans) { | |
4061 | slot++; | |
4062 | continue; | |
4063 | } | |
4064 | if (!cache_only) | |
4065 | break; | |
4066 | ||
e02119d5 CM |
4067 | if (max_key) { |
4068 | btrfs_node_key(cur, &disk_key, slot); | |
4069 | if (comp_keys(&disk_key, max_key) >= 0) { | |
4070 | ret = 1; | |
4071 | goto out; | |
4072 | } | |
4073 | } | |
4074 | ||
3f157a2f CM |
4075 | tmp = btrfs_find_tree_block(root, blockptr, |
4076 | btrfs_level_size(root, level - 1)); | |
4077 | ||
4078 | if (tmp && btrfs_buffer_uptodate(tmp, gen)) { | |
4079 | free_extent_buffer(tmp); | |
4080 | break; | |
4081 | } | |
4082 | if (tmp) | |
4083 | free_extent_buffer(tmp); | |
4084 | slot++; | |
4085 | } | |
e02119d5 | 4086 | find_next_key: |
3f157a2f CM |
4087 | /* |
4088 | * we didn't find a candidate key in this node, walk forward | |
4089 | * and find another one | |
4090 | */ | |
4091 | if (slot >= nritems) { | |
e02119d5 | 4092 | path->slots[level] = slot; |
b4ce94de | 4093 | btrfs_set_path_blocking(path); |
e02119d5 | 4094 | sret = btrfs_find_next_key(root, path, min_key, level, |
3f157a2f | 4095 | cache_only, min_trans); |
e02119d5 | 4096 | if (sret == 0) { |
3f157a2f CM |
4097 | btrfs_release_path(root, path); |
4098 | goto again; | |
4099 | } else { | |
4100 | goto out; | |
4101 | } | |
4102 | } | |
4103 | /* save our key for returning back */ | |
4104 | btrfs_node_key_to_cpu(cur, &found_key, slot); | |
4105 | path->slots[level] = slot; | |
4106 | if (level == path->lowest_level) { | |
4107 | ret = 0; | |
4108 | unlock_up(path, level, 1); | |
4109 | goto out; | |
4110 | } | |
b4ce94de | 4111 | btrfs_set_path_blocking(path); |
3f157a2f CM |
4112 | cur = read_node_slot(root, cur, slot); |
4113 | ||
4114 | btrfs_tree_lock(cur); | |
b4ce94de | 4115 | |
3f157a2f CM |
4116 | path->locks[level - 1] = 1; |
4117 | path->nodes[level - 1] = cur; | |
4118 | unlock_up(path, level, 1); | |
4008c04a | 4119 | btrfs_clear_path_blocking(path, NULL); |
3f157a2f CM |
4120 | } |
4121 | out: | |
4122 | if (ret == 0) | |
4123 | memcpy(min_key, &found_key, sizeof(found_key)); | |
b4ce94de | 4124 | btrfs_set_path_blocking(path); |
3f157a2f CM |
4125 | return ret; |
4126 | } | |
4127 | ||
4128 | /* | |
4129 | * this is similar to btrfs_next_leaf, but does not try to preserve | |
4130 | * and fixup the path. It looks for and returns the next key in the | |
4131 | * tree based on the current path and the cache_only and min_trans | |
4132 | * parameters. | |
4133 | * | |
4134 | * 0 is returned if another key is found, < 0 if there are any errors | |
4135 | * and 1 is returned if there are no higher keys in the tree | |
4136 | * | |
4137 | * path->keep_locks should be set to 1 on the search made before | |
4138 | * calling this function. | |
4139 | */ | |
e7a84565 | 4140 | int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path, |
33c66f43 | 4141 | struct btrfs_key *key, int level, |
3f157a2f | 4142 | int cache_only, u64 min_trans) |
e7a84565 | 4143 | { |
e7a84565 CM |
4144 | int slot; |
4145 | struct extent_buffer *c; | |
4146 | ||
934d375b | 4147 | WARN_ON(!path->keep_locks); |
d397712b | 4148 | while (level < BTRFS_MAX_LEVEL) { |
e7a84565 CM |
4149 | if (!path->nodes[level]) |
4150 | return 1; | |
4151 | ||
4152 | slot = path->slots[level] + 1; | |
4153 | c = path->nodes[level]; | |
3f157a2f | 4154 | next: |
e7a84565 | 4155 | if (slot >= btrfs_header_nritems(c)) { |
33c66f43 YZ |
4156 | int ret; |
4157 | int orig_lowest; | |
4158 | struct btrfs_key cur_key; | |
4159 | if (level + 1 >= BTRFS_MAX_LEVEL || | |
4160 | !path->nodes[level + 1]) | |
e7a84565 | 4161 | return 1; |
33c66f43 YZ |
4162 | |
4163 | if (path->locks[level + 1]) { | |
4164 | level++; | |
4165 | continue; | |
4166 | } | |
4167 | ||
4168 | slot = btrfs_header_nritems(c) - 1; | |
4169 | if (level == 0) | |
4170 | btrfs_item_key_to_cpu(c, &cur_key, slot); | |
4171 | else | |
4172 | btrfs_node_key_to_cpu(c, &cur_key, slot); | |
4173 | ||
4174 | orig_lowest = path->lowest_level; | |
4175 | btrfs_release_path(root, path); | |
4176 | path->lowest_level = level; | |
4177 | ret = btrfs_search_slot(NULL, root, &cur_key, path, | |
4178 | 0, 0); | |
4179 | path->lowest_level = orig_lowest; | |
4180 | if (ret < 0) | |
4181 | return ret; | |
4182 | ||
4183 | c = path->nodes[level]; | |
4184 | slot = path->slots[level]; | |
4185 | if (ret == 0) | |
4186 | slot++; | |
4187 | goto next; | |
e7a84565 | 4188 | } |
33c66f43 | 4189 | |
e7a84565 CM |
4190 | if (level == 0) |
4191 | btrfs_item_key_to_cpu(c, key, slot); | |
3f157a2f CM |
4192 | else { |
4193 | u64 blockptr = btrfs_node_blockptr(c, slot); | |
4194 | u64 gen = btrfs_node_ptr_generation(c, slot); | |
4195 | ||
4196 | if (cache_only) { | |
4197 | struct extent_buffer *cur; | |
4198 | cur = btrfs_find_tree_block(root, blockptr, | |
4199 | btrfs_level_size(root, level - 1)); | |
4200 | if (!cur || !btrfs_buffer_uptodate(cur, gen)) { | |
4201 | slot++; | |
4202 | if (cur) | |
4203 | free_extent_buffer(cur); | |
4204 | goto next; | |
4205 | } | |
4206 | free_extent_buffer(cur); | |
4207 | } | |
4208 | if (gen < min_trans) { | |
4209 | slot++; | |
4210 | goto next; | |
4211 | } | |
e7a84565 | 4212 | btrfs_node_key_to_cpu(c, key, slot); |
3f157a2f | 4213 | } |
e7a84565 CM |
4214 | return 0; |
4215 | } | |
4216 | return 1; | |
4217 | } | |
4218 | ||
97571fd0 | 4219 | /* |
925baedd | 4220 | * search the tree again to find a leaf with greater keys |
0f70abe2 CM |
4221 | * returns 0 if it found something or 1 if there are no greater leaves. |
4222 | * returns < 0 on io errors. | |
97571fd0 | 4223 | */ |
234b63a0 | 4224 | int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path) |
d97e63b6 CM |
4225 | { |
4226 | int slot; | |
8e73f275 | 4227 | int level; |
5f39d397 | 4228 | struct extent_buffer *c; |
8e73f275 | 4229 | struct extent_buffer *next; |
925baedd CM |
4230 | struct btrfs_key key; |
4231 | u32 nritems; | |
4232 | int ret; | |
8e73f275 CM |
4233 | int old_spinning = path->leave_spinning; |
4234 | int force_blocking = 0; | |
925baedd CM |
4235 | |
4236 | nritems = btrfs_header_nritems(path->nodes[0]); | |
d397712b | 4237 | if (nritems == 0) |
925baedd | 4238 | return 1; |
925baedd | 4239 | |
8e73f275 CM |
4240 | /* |
4241 | * we take the blocks in an order that upsets lockdep. Using | |
4242 | * blocking mode is the only way around it. | |
4243 | */ | |
4244 | #ifdef CONFIG_DEBUG_LOCK_ALLOC | |
4245 | force_blocking = 1; | |
4246 | #endif | |
925baedd | 4247 | |
8e73f275 CM |
4248 | btrfs_item_key_to_cpu(path->nodes[0], &key, nritems - 1); |
4249 | again: | |
4250 | level = 1; | |
4251 | next = NULL; | |
925baedd | 4252 | btrfs_release_path(root, path); |
8e73f275 | 4253 | |
a2135011 | 4254 | path->keep_locks = 1; |
8e73f275 CM |
4255 | |
4256 | if (!force_blocking) | |
4257 | path->leave_spinning = 1; | |
4258 | ||
925baedd CM |
4259 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
4260 | path->keep_locks = 0; | |
4261 | ||
4262 | if (ret < 0) | |
4263 | return ret; | |
4264 | ||
a2135011 | 4265 | nritems = btrfs_header_nritems(path->nodes[0]); |
168fd7d2 CM |
4266 | /* |
4267 | * by releasing the path above we dropped all our locks. A balance | |
4268 | * could have added more items next to the key that used to be | |
4269 | * at the very end of the block. So, check again here and | |
4270 | * advance the path if there are now more items available. | |
4271 | */ | |
a2135011 | 4272 | if (nritems > 0 && path->slots[0] < nritems - 1) { |
e457afec YZ |
4273 | if (ret == 0) |
4274 | path->slots[0]++; | |
8e73f275 | 4275 | ret = 0; |
925baedd CM |
4276 | goto done; |
4277 | } | |
d97e63b6 | 4278 | |
d397712b | 4279 | while (level < BTRFS_MAX_LEVEL) { |
8e73f275 CM |
4280 | if (!path->nodes[level]) { |
4281 | ret = 1; | |
4282 | goto done; | |
4283 | } | |
5f39d397 | 4284 | |
d97e63b6 CM |
4285 | slot = path->slots[level] + 1; |
4286 | c = path->nodes[level]; | |
5f39d397 | 4287 | if (slot >= btrfs_header_nritems(c)) { |
d97e63b6 | 4288 | level++; |
8e73f275 CM |
4289 | if (level == BTRFS_MAX_LEVEL) { |
4290 | ret = 1; | |
4291 | goto done; | |
4292 | } | |
d97e63b6 CM |
4293 | continue; |
4294 | } | |
5f39d397 | 4295 | |
925baedd CM |
4296 | if (next) { |
4297 | btrfs_tree_unlock(next); | |
5f39d397 | 4298 | free_extent_buffer(next); |
925baedd | 4299 | } |
5f39d397 | 4300 | |
8e73f275 CM |
4301 | next = c; |
4302 | ret = read_block_for_search(NULL, root, path, &next, level, | |
4303 | slot, &key); | |
4304 | if (ret == -EAGAIN) | |
4305 | goto again; | |
5f39d397 | 4306 | |
76a05b35 CM |
4307 | if (ret < 0) { |
4308 | btrfs_release_path(root, path); | |
4309 | goto done; | |
4310 | } | |
4311 | ||
5cd57b2c | 4312 | if (!path->skip_locking) { |
8e73f275 CM |
4313 | ret = btrfs_try_spin_lock(next); |
4314 | if (!ret) { | |
4315 | btrfs_set_path_blocking(path); | |
4316 | btrfs_tree_lock(next); | |
4317 | if (!force_blocking) | |
4318 | btrfs_clear_path_blocking(path, next); | |
4319 | } | |
4320 | if (force_blocking) | |
4321 | btrfs_set_lock_blocking(next); | |
5cd57b2c | 4322 | } |
d97e63b6 CM |
4323 | break; |
4324 | } | |
4325 | path->slots[level] = slot; | |
d397712b | 4326 | while (1) { |
d97e63b6 CM |
4327 | level--; |
4328 | c = path->nodes[level]; | |
925baedd CM |
4329 | if (path->locks[level]) |
4330 | btrfs_tree_unlock(c); | |
8e73f275 | 4331 | |
5f39d397 | 4332 | free_extent_buffer(c); |
d97e63b6 CM |
4333 | path->nodes[level] = next; |
4334 | path->slots[level] = 0; | |
a74a4b97 CM |
4335 | if (!path->skip_locking) |
4336 | path->locks[level] = 1; | |
8e73f275 | 4337 | |
d97e63b6 CM |
4338 | if (!level) |
4339 | break; | |
b4ce94de | 4340 | |
8e73f275 CM |
4341 | ret = read_block_for_search(NULL, root, path, &next, level, |
4342 | 0, &key); | |
4343 | if (ret == -EAGAIN) | |
4344 | goto again; | |
4345 | ||
76a05b35 CM |
4346 | if (ret < 0) { |
4347 | btrfs_release_path(root, path); | |
4348 | goto done; | |
4349 | } | |
4350 | ||
5cd57b2c | 4351 | if (!path->skip_locking) { |
b9447ef8 | 4352 | btrfs_assert_tree_locked(path->nodes[level]); |
8e73f275 CM |
4353 | ret = btrfs_try_spin_lock(next); |
4354 | if (!ret) { | |
4355 | btrfs_set_path_blocking(path); | |
4356 | btrfs_tree_lock(next); | |
4357 | if (!force_blocking) | |
4358 | btrfs_clear_path_blocking(path, next); | |
4359 | } | |
4360 | if (force_blocking) | |
4361 | btrfs_set_lock_blocking(next); | |
5cd57b2c | 4362 | } |
d97e63b6 | 4363 | } |
8e73f275 | 4364 | ret = 0; |
925baedd CM |
4365 | done: |
4366 | unlock_up(path, 0, 1); | |
8e73f275 CM |
4367 | path->leave_spinning = old_spinning; |
4368 | if (!old_spinning) | |
4369 | btrfs_set_path_blocking(path); | |
4370 | ||
4371 | return ret; | |
d97e63b6 | 4372 | } |
0b86a832 | 4373 | |
3f157a2f CM |
4374 | /* |
4375 | * this uses btrfs_prev_leaf to walk backwards in the tree, and keeps | |
4376 | * searching until it gets past min_objectid or finds an item of 'type' | |
4377 | * | |
4378 | * returns 0 if something is found, 1 if nothing was found and < 0 on error | |
4379 | */ | |
0b86a832 CM |
4380 | int btrfs_previous_item(struct btrfs_root *root, |
4381 | struct btrfs_path *path, u64 min_objectid, | |
4382 | int type) | |
4383 | { | |
4384 | struct btrfs_key found_key; | |
4385 | struct extent_buffer *leaf; | |
e02119d5 | 4386 | u32 nritems; |
0b86a832 CM |
4387 | int ret; |
4388 | ||
d397712b | 4389 | while (1) { |
0b86a832 | 4390 | if (path->slots[0] == 0) { |
b4ce94de | 4391 | btrfs_set_path_blocking(path); |
0b86a832 CM |
4392 | ret = btrfs_prev_leaf(root, path); |
4393 | if (ret != 0) | |
4394 | return ret; | |
4395 | } else { | |
4396 | path->slots[0]--; | |
4397 | } | |
4398 | leaf = path->nodes[0]; | |
e02119d5 CM |
4399 | nritems = btrfs_header_nritems(leaf); |
4400 | if (nritems == 0) | |
4401 | return 1; | |
4402 | if (path->slots[0] == nritems) | |
4403 | path->slots[0]--; | |
4404 | ||
0b86a832 | 4405 | btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); |
e02119d5 CM |
4406 | if (found_key.objectid < min_objectid) |
4407 | break; | |
0a4eefbb YZ |
4408 | if (found_key.type == type) |
4409 | return 0; | |
e02119d5 CM |
4410 | if (found_key.objectid == min_objectid && |
4411 | found_key.type < type) | |
4412 | break; | |
0b86a832 CM |
4413 | } |
4414 | return 1; | |
4415 | } |