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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> |
eb60ceac CM |
20 | #include "ctree.h" |
21 | #include "disk-io.h" | |
7f5c1516 | 22 | #include "transaction.h" |
5f39d397 | 23 | #include "print-tree.h" |
925baedd | 24 | #include "locking.h" |
9a8dd150 | 25 | |
e089f05c CM |
26 | static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root |
27 | *root, struct btrfs_path *path, int level); | |
28 | static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root | |
d4dbff95 | 29 | *root, struct btrfs_key *ins_key, |
cc0c5538 | 30 | struct btrfs_path *path, int data_size, int extend); |
5f39d397 CM |
31 | static int push_node_left(struct btrfs_trans_handle *trans, |
32 | struct btrfs_root *root, struct extent_buffer *dst, | |
971a1f66 | 33 | struct extent_buffer *src, int empty); |
5f39d397 CM |
34 | static int balance_node_right(struct btrfs_trans_handle *trans, |
35 | struct btrfs_root *root, | |
36 | struct extent_buffer *dst_buf, | |
37 | struct extent_buffer *src_buf); | |
e089f05c CM |
38 | static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
39 | struct btrfs_path *path, int level, int slot); | |
d97e63b6 | 40 | |
df24a2b9 | 41 | struct btrfs_path *btrfs_alloc_path(void) |
2c90e5d6 | 42 | { |
df24a2b9 | 43 | struct btrfs_path *path; |
e00f7308 JM |
44 | path = kmem_cache_zalloc(btrfs_path_cachep, GFP_NOFS); |
45 | if (path) | |
2cc58cf2 | 46 | path->reada = 1; |
df24a2b9 | 47 | return path; |
2c90e5d6 CM |
48 | } |
49 | ||
b4ce94de CM |
50 | /* |
51 | * set all locked nodes in the path to blocking locks. This should | |
52 | * be done before scheduling | |
53 | */ | |
54 | noinline void btrfs_set_path_blocking(struct btrfs_path *p) | |
55 | { | |
56 | int i; | |
57 | for (i = 0; i < BTRFS_MAX_LEVEL; i++) { | |
58 | if (p->nodes[i] && p->locks[i]) | |
59 | btrfs_set_lock_blocking(p->nodes[i]); | |
60 | } | |
61 | } | |
62 | ||
63 | /* | |
64 | * reset all the locked nodes in the patch to spinning locks. | |
4008c04a CM |
65 | * |
66 | * held is used to keep lockdep happy, when lockdep is enabled | |
67 | * we set held to a blocking lock before we go around and | |
68 | * retake all the spinlocks in the path. You can safely use NULL | |
69 | * for held | |
b4ce94de | 70 | */ |
4008c04a CM |
71 | noinline void btrfs_clear_path_blocking(struct btrfs_path *p, |
72 | struct extent_buffer *held) | |
b4ce94de CM |
73 | { |
74 | int i; | |
4008c04a CM |
75 | |
76 | #ifdef CONFIG_DEBUG_LOCK_ALLOC | |
77 | /* lockdep really cares that we take all of these spinlocks | |
78 | * in the right order. If any of the locks in the path are not | |
79 | * currently blocking, it is going to complain. So, make really | |
80 | * really sure by forcing the path to blocking before we clear | |
81 | * the path blocking. | |
82 | */ | |
83 | if (held) | |
84 | btrfs_set_lock_blocking(held); | |
85 | btrfs_set_path_blocking(p); | |
86 | #endif | |
87 | ||
88 | for (i = BTRFS_MAX_LEVEL - 1; i >= 0; i--) { | |
b4ce94de CM |
89 | if (p->nodes[i] && p->locks[i]) |
90 | btrfs_clear_lock_blocking(p->nodes[i]); | |
91 | } | |
4008c04a CM |
92 | |
93 | #ifdef CONFIG_DEBUG_LOCK_ALLOC | |
94 | if (held) | |
95 | btrfs_clear_lock_blocking(held); | |
96 | #endif | |
b4ce94de CM |
97 | } |
98 | ||
d352ac68 | 99 | /* this also releases the path */ |
df24a2b9 | 100 | void btrfs_free_path(struct btrfs_path *p) |
be0e5c09 | 101 | { |
df24a2b9 CM |
102 | btrfs_release_path(NULL, p); |
103 | kmem_cache_free(btrfs_path_cachep, p); | |
be0e5c09 CM |
104 | } |
105 | ||
d352ac68 CM |
106 | /* |
107 | * path release drops references on the extent buffers in the path | |
108 | * and it drops any locks held by this path | |
109 | * | |
110 | * It is safe to call this on paths that no locks or extent buffers held. | |
111 | */ | |
d397712b | 112 | noinline void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p) |
eb60ceac CM |
113 | { |
114 | int i; | |
a2135011 | 115 | |
234b63a0 | 116 | for (i = 0; i < BTRFS_MAX_LEVEL; i++) { |
3f157a2f | 117 | p->slots[i] = 0; |
eb60ceac | 118 | if (!p->nodes[i]) |
925baedd CM |
119 | continue; |
120 | if (p->locks[i]) { | |
121 | btrfs_tree_unlock(p->nodes[i]); | |
122 | p->locks[i] = 0; | |
123 | } | |
5f39d397 | 124 | free_extent_buffer(p->nodes[i]); |
3f157a2f | 125 | p->nodes[i] = NULL; |
eb60ceac CM |
126 | } |
127 | } | |
128 | ||
d352ac68 CM |
129 | /* |
130 | * safely gets a reference on the root node of a tree. A lock | |
131 | * is not taken, so a concurrent writer may put a different node | |
132 | * at the root of the tree. See btrfs_lock_root_node for the | |
133 | * looping required. | |
134 | * | |
135 | * The extent buffer returned by this has a reference taken, so | |
136 | * it won't disappear. It may stop being the root of the tree | |
137 | * at any time because there are no locks held. | |
138 | */ | |
925baedd CM |
139 | struct extent_buffer *btrfs_root_node(struct btrfs_root *root) |
140 | { | |
141 | struct extent_buffer *eb; | |
142 | spin_lock(&root->node_lock); | |
143 | eb = root->node; | |
144 | extent_buffer_get(eb); | |
145 | spin_unlock(&root->node_lock); | |
146 | return eb; | |
147 | } | |
148 | ||
d352ac68 CM |
149 | /* loop around taking references on and locking the root node of the |
150 | * tree until you end up with a lock on the root. A locked buffer | |
151 | * is returned, with a reference held. | |
152 | */ | |
925baedd CM |
153 | struct extent_buffer *btrfs_lock_root_node(struct btrfs_root *root) |
154 | { | |
155 | struct extent_buffer *eb; | |
156 | ||
d397712b | 157 | while (1) { |
925baedd CM |
158 | eb = btrfs_root_node(root); |
159 | btrfs_tree_lock(eb); | |
160 | ||
161 | spin_lock(&root->node_lock); | |
162 | if (eb == root->node) { | |
163 | spin_unlock(&root->node_lock); | |
164 | break; | |
165 | } | |
166 | spin_unlock(&root->node_lock); | |
167 | ||
168 | btrfs_tree_unlock(eb); | |
169 | free_extent_buffer(eb); | |
170 | } | |
171 | return eb; | |
172 | } | |
173 | ||
d352ac68 CM |
174 | /* cowonly root (everything not a reference counted cow subvolume), just get |
175 | * put onto a simple dirty list. transaction.c walks this to make sure they | |
176 | * get properly updated on disk. | |
177 | */ | |
0b86a832 CM |
178 | static void add_root_to_dirty_list(struct btrfs_root *root) |
179 | { | |
180 | if (root->track_dirty && list_empty(&root->dirty_list)) { | |
181 | list_add(&root->dirty_list, | |
182 | &root->fs_info->dirty_cowonly_roots); | |
183 | } | |
184 | } | |
185 | ||
d352ac68 CM |
186 | /* |
187 | * used by snapshot creation to make a copy of a root for a tree with | |
188 | * a given objectid. The buffer with the new root node is returned in | |
189 | * cow_ret, and this func returns zero on success or a negative error code. | |
190 | */ | |
be20aa9d CM |
191 | int btrfs_copy_root(struct btrfs_trans_handle *trans, |
192 | struct btrfs_root *root, | |
193 | struct extent_buffer *buf, | |
194 | struct extent_buffer **cow_ret, u64 new_root_objectid) | |
195 | { | |
196 | struct extent_buffer *cow; | |
197 | u32 nritems; | |
198 | int ret = 0; | |
199 | int level; | |
5d4f98a2 | 200 | struct btrfs_disk_key disk_key; |
be20aa9d CM |
201 | |
202 | WARN_ON(root->ref_cows && trans->transid != | |
203 | root->fs_info->running_transaction->transid); | |
204 | WARN_ON(root->ref_cows && trans->transid != root->last_trans); | |
205 | ||
206 | level = btrfs_header_level(buf); | |
207 | nritems = btrfs_header_nritems(buf); | |
5d4f98a2 YZ |
208 | if (level == 0) |
209 | btrfs_item_key(buf, &disk_key, 0); | |
210 | else | |
211 | btrfs_node_key(buf, &disk_key, 0); | |
31840ae1 | 212 | |
5d4f98a2 YZ |
213 | cow = btrfs_alloc_free_block(trans, root, buf->len, 0, |
214 | new_root_objectid, &disk_key, level, | |
215 | buf->start, 0); | |
216 | if (IS_ERR(cow)) | |
be20aa9d CM |
217 | return PTR_ERR(cow); |
218 | ||
219 | copy_extent_buffer(cow, buf, 0, 0, cow->len); | |
220 | btrfs_set_header_bytenr(cow, cow->start); | |
221 | btrfs_set_header_generation(cow, trans->transid); | |
5d4f98a2 YZ |
222 | btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV); |
223 | btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN | | |
224 | BTRFS_HEADER_FLAG_RELOC); | |
225 | if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID) | |
226 | btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC); | |
227 | else | |
228 | btrfs_set_header_owner(cow, new_root_objectid); | |
be20aa9d | 229 | |
2b82032c YZ |
230 | write_extent_buffer(cow, root->fs_info->fsid, |
231 | (unsigned long)btrfs_header_fsid(cow), | |
232 | BTRFS_FSID_SIZE); | |
233 | ||
be20aa9d | 234 | WARN_ON(btrfs_header_generation(buf) > trans->transid); |
5d4f98a2 YZ |
235 | if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID) |
236 | ret = btrfs_inc_ref(trans, root, cow, 1); | |
237 | else | |
238 | ret = btrfs_inc_ref(trans, root, cow, 0); | |
4aec2b52 | 239 | |
be20aa9d CM |
240 | if (ret) |
241 | return ret; | |
242 | ||
243 | btrfs_mark_buffer_dirty(cow); | |
244 | *cow_ret = cow; | |
245 | return 0; | |
246 | } | |
247 | ||
5d4f98a2 YZ |
248 | /* |
249 | * check if the tree block can be shared by multiple trees | |
250 | */ | |
251 | int btrfs_block_can_be_shared(struct btrfs_root *root, | |
252 | struct extent_buffer *buf) | |
253 | { | |
254 | /* | |
255 | * Tree blocks not in refernece counted trees and tree roots | |
256 | * are never shared. If a block was allocated after the last | |
257 | * snapshot and the block was not allocated by tree relocation, | |
258 | * we know the block is not shared. | |
259 | */ | |
260 | if (root->ref_cows && | |
261 | buf != root->node && buf != root->commit_root && | |
262 | (btrfs_header_generation(buf) <= | |
263 | btrfs_root_last_snapshot(&root->root_item) || | |
264 | btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC))) | |
265 | return 1; | |
266 | #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 | |
267 | if (root->ref_cows && | |
268 | btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) | |
269 | return 1; | |
270 | #endif | |
271 | return 0; | |
272 | } | |
273 | ||
274 | static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans, | |
275 | struct btrfs_root *root, | |
276 | struct extent_buffer *buf, | |
277 | struct extent_buffer *cow) | |
278 | { | |
279 | u64 refs; | |
280 | u64 owner; | |
281 | u64 flags; | |
282 | u64 new_flags = 0; | |
283 | int ret; | |
284 | ||
285 | /* | |
286 | * Backrefs update rules: | |
287 | * | |
288 | * Always use full backrefs for extent pointers in tree block | |
289 | * allocated by tree relocation. | |
290 | * | |
291 | * If a shared tree block is no longer referenced by its owner | |
292 | * tree (btrfs_header_owner(buf) == root->root_key.objectid), | |
293 | * use full backrefs for extent pointers in tree block. | |
294 | * | |
295 | * If a tree block is been relocating | |
296 | * (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID), | |
297 | * use full backrefs for extent pointers in tree block. | |
298 | * The reason for this is some operations (such as drop tree) | |
299 | * are only allowed for blocks use full backrefs. | |
300 | */ | |
301 | ||
302 | if (btrfs_block_can_be_shared(root, buf)) { | |
303 | ret = btrfs_lookup_extent_info(trans, root, buf->start, | |
304 | buf->len, &refs, &flags); | |
305 | BUG_ON(ret); | |
306 | BUG_ON(refs == 0); | |
307 | } else { | |
308 | refs = 1; | |
309 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID || | |
310 | btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) | |
311 | flags = BTRFS_BLOCK_FLAG_FULL_BACKREF; | |
312 | else | |
313 | flags = 0; | |
314 | } | |
315 | ||
316 | owner = btrfs_header_owner(buf); | |
317 | BUG_ON(owner == BTRFS_TREE_RELOC_OBJECTID && | |
318 | !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)); | |
319 | ||
320 | if (refs > 1) { | |
321 | if ((owner == root->root_key.objectid || | |
322 | root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) && | |
323 | !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)) { | |
324 | ret = btrfs_inc_ref(trans, root, buf, 1); | |
325 | BUG_ON(ret); | |
326 | ||
327 | if (root->root_key.objectid == | |
328 | BTRFS_TREE_RELOC_OBJECTID) { | |
329 | ret = btrfs_dec_ref(trans, root, buf, 0); | |
330 | BUG_ON(ret); | |
331 | ret = btrfs_inc_ref(trans, root, cow, 1); | |
332 | BUG_ON(ret); | |
333 | } | |
334 | new_flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF; | |
335 | } else { | |
336 | ||
337 | if (root->root_key.objectid == | |
338 | BTRFS_TREE_RELOC_OBJECTID) | |
339 | ret = btrfs_inc_ref(trans, root, cow, 1); | |
340 | else | |
341 | ret = btrfs_inc_ref(trans, root, cow, 0); | |
342 | BUG_ON(ret); | |
343 | } | |
344 | if (new_flags != 0) { | |
345 | ret = btrfs_set_disk_extent_flags(trans, root, | |
346 | buf->start, | |
347 | buf->len, | |
348 | new_flags, 0); | |
349 | BUG_ON(ret); | |
350 | } | |
351 | } else { | |
352 | if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF) { | |
353 | if (root->root_key.objectid == | |
354 | BTRFS_TREE_RELOC_OBJECTID) | |
355 | ret = btrfs_inc_ref(trans, root, cow, 1); | |
356 | else | |
357 | ret = btrfs_inc_ref(trans, root, cow, 0); | |
358 | BUG_ON(ret); | |
359 | ret = btrfs_dec_ref(trans, root, buf, 1); | |
360 | BUG_ON(ret); | |
361 | } | |
362 | clean_tree_block(trans, root, buf); | |
363 | } | |
364 | return 0; | |
365 | } | |
366 | ||
d352ac68 | 367 | /* |
d397712b CM |
368 | * does the dirty work in cow of a single block. The parent block (if |
369 | * supplied) is updated to point to the new cow copy. The new buffer is marked | |
370 | * dirty and returned locked. If you modify the block it needs to be marked | |
371 | * dirty again. | |
d352ac68 CM |
372 | * |
373 | * search_start -- an allocation hint for the new block | |
374 | * | |
d397712b CM |
375 | * empty_size -- a hint that you plan on doing more cow. This is the size in |
376 | * bytes the allocator should try to find free next to the block it returns. | |
377 | * This is just a hint and may be ignored by the allocator. | |
d352ac68 | 378 | */ |
d397712b | 379 | static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans, |
5f39d397 CM |
380 | struct btrfs_root *root, |
381 | struct extent_buffer *buf, | |
382 | struct extent_buffer *parent, int parent_slot, | |
383 | struct extent_buffer **cow_ret, | |
9fa8cfe7 | 384 | u64 search_start, u64 empty_size) |
02217ed2 | 385 | { |
5d4f98a2 | 386 | struct btrfs_disk_key disk_key; |
5f39d397 | 387 | struct extent_buffer *cow; |
7bb86316 | 388 | int level; |
925baedd | 389 | int unlock_orig = 0; |
5d4f98a2 | 390 | u64 parent_start; |
7bb86316 | 391 | |
925baedd CM |
392 | if (*cow_ret == buf) |
393 | unlock_orig = 1; | |
394 | ||
b9447ef8 | 395 | btrfs_assert_tree_locked(buf); |
925baedd | 396 | |
7bb86316 CM |
397 | WARN_ON(root->ref_cows && trans->transid != |
398 | root->fs_info->running_transaction->transid); | |
6702ed49 | 399 | WARN_ON(root->ref_cows && trans->transid != root->last_trans); |
5f39d397 | 400 | |
7bb86316 | 401 | level = btrfs_header_level(buf); |
31840ae1 | 402 | |
5d4f98a2 YZ |
403 | if (level == 0) |
404 | btrfs_item_key(buf, &disk_key, 0); | |
405 | else | |
406 | btrfs_node_key(buf, &disk_key, 0); | |
407 | ||
408 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) { | |
409 | if (parent) | |
410 | parent_start = parent->start; | |
411 | else | |
412 | parent_start = 0; | |
413 | } else | |
414 | parent_start = 0; | |
415 | ||
416 | cow = btrfs_alloc_free_block(trans, root, buf->len, parent_start, | |
417 | root->root_key.objectid, &disk_key, | |
418 | level, search_start, empty_size); | |
54aa1f4d CM |
419 | if (IS_ERR(cow)) |
420 | return PTR_ERR(cow); | |
6702ed49 | 421 | |
b4ce94de CM |
422 | /* cow is set to blocking by btrfs_init_new_buffer */ |
423 | ||
5f39d397 | 424 | copy_extent_buffer(cow, buf, 0, 0, cow->len); |
db94535d | 425 | btrfs_set_header_bytenr(cow, cow->start); |
5f39d397 | 426 | btrfs_set_header_generation(cow, trans->transid); |
5d4f98a2 YZ |
427 | btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV); |
428 | btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN | | |
429 | BTRFS_HEADER_FLAG_RELOC); | |
430 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) | |
431 | btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC); | |
432 | else | |
433 | btrfs_set_header_owner(cow, root->root_key.objectid); | |
6702ed49 | 434 | |
2b82032c YZ |
435 | write_extent_buffer(cow, root->fs_info->fsid, |
436 | (unsigned long)btrfs_header_fsid(cow), | |
437 | BTRFS_FSID_SIZE); | |
438 | ||
5d4f98a2 | 439 | update_ref_for_cow(trans, root, buf, cow); |
1a40e23b | 440 | |
02217ed2 | 441 | if (buf == root->node) { |
925baedd | 442 | WARN_ON(parent && parent != buf); |
5d4f98a2 YZ |
443 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID || |
444 | btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) | |
445 | parent_start = buf->start; | |
446 | else | |
447 | parent_start = 0; | |
925baedd CM |
448 | |
449 | spin_lock(&root->node_lock); | |
02217ed2 | 450 | root->node = cow; |
5f39d397 | 451 | extent_buffer_get(cow); |
925baedd CM |
452 | spin_unlock(&root->node_lock); |
453 | ||
5d4f98a2 YZ |
454 | btrfs_free_extent(trans, root, buf->start, buf->len, |
455 | parent_start, root->root_key.objectid, | |
456 | level, 0); | |
5f39d397 | 457 | free_extent_buffer(buf); |
0b86a832 | 458 | add_root_to_dirty_list(root); |
02217ed2 | 459 | } else { |
5d4f98a2 YZ |
460 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) |
461 | parent_start = parent->start; | |
462 | else | |
463 | parent_start = 0; | |
464 | ||
465 | WARN_ON(trans->transid != btrfs_header_generation(parent)); | |
5f39d397 | 466 | btrfs_set_node_blockptr(parent, parent_slot, |
db94535d | 467 | cow->start); |
74493f7a CM |
468 | btrfs_set_node_ptr_generation(parent, parent_slot, |
469 | trans->transid); | |
d6025579 | 470 | btrfs_mark_buffer_dirty(parent); |
7bb86316 | 471 | btrfs_free_extent(trans, root, buf->start, buf->len, |
5d4f98a2 YZ |
472 | parent_start, root->root_key.objectid, |
473 | level, 0); | |
02217ed2 | 474 | } |
925baedd CM |
475 | if (unlock_orig) |
476 | btrfs_tree_unlock(buf); | |
5f39d397 | 477 | free_extent_buffer(buf); |
ccd467d6 | 478 | btrfs_mark_buffer_dirty(cow); |
2c90e5d6 | 479 | *cow_ret = cow; |
02217ed2 CM |
480 | return 0; |
481 | } | |
482 | ||
5d4f98a2 YZ |
483 | static inline int should_cow_block(struct btrfs_trans_handle *trans, |
484 | struct btrfs_root *root, | |
485 | struct extent_buffer *buf) | |
486 | { | |
487 | if (btrfs_header_generation(buf) == trans->transid && | |
488 | !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN) && | |
489 | !(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID && | |
490 | btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC))) | |
491 | return 0; | |
492 | return 1; | |
493 | } | |
494 | ||
d352ac68 CM |
495 | /* |
496 | * cows a single block, see __btrfs_cow_block for the real work. | |
497 | * This version of it has extra checks so that a block isn't cow'd more than | |
498 | * once per transaction, as long as it hasn't been written yet | |
499 | */ | |
d397712b | 500 | noinline int btrfs_cow_block(struct btrfs_trans_handle *trans, |
5f39d397 CM |
501 | struct btrfs_root *root, struct extent_buffer *buf, |
502 | struct extent_buffer *parent, int parent_slot, | |
9fa8cfe7 | 503 | struct extent_buffer **cow_ret) |
6702ed49 CM |
504 | { |
505 | u64 search_start; | |
f510cfec | 506 | int ret; |
dc17ff8f | 507 | |
6702ed49 | 508 | if (trans->transaction != root->fs_info->running_transaction) { |
d397712b CM |
509 | printk(KERN_CRIT "trans %llu running %llu\n", |
510 | (unsigned long long)trans->transid, | |
511 | (unsigned long long) | |
6702ed49 CM |
512 | root->fs_info->running_transaction->transid); |
513 | WARN_ON(1); | |
514 | } | |
515 | if (trans->transid != root->fs_info->generation) { | |
d397712b CM |
516 | printk(KERN_CRIT "trans %llu running %llu\n", |
517 | (unsigned long long)trans->transid, | |
518 | (unsigned long long)root->fs_info->generation); | |
6702ed49 CM |
519 | WARN_ON(1); |
520 | } | |
dc17ff8f | 521 | |
5d4f98a2 | 522 | if (!should_cow_block(trans, root, buf)) { |
6702ed49 CM |
523 | *cow_ret = buf; |
524 | return 0; | |
525 | } | |
c487685d | 526 | |
0b86a832 | 527 | search_start = buf->start & ~((u64)(1024 * 1024 * 1024) - 1); |
b4ce94de CM |
528 | |
529 | if (parent) | |
530 | btrfs_set_lock_blocking(parent); | |
531 | btrfs_set_lock_blocking(buf); | |
532 | ||
f510cfec | 533 | ret = __btrfs_cow_block(trans, root, buf, parent, |
9fa8cfe7 | 534 | parent_slot, cow_ret, search_start, 0); |
f510cfec | 535 | return ret; |
6702ed49 CM |
536 | } |
537 | ||
d352ac68 CM |
538 | /* |
539 | * helper function for defrag to decide if two blocks pointed to by a | |
540 | * node are actually close by | |
541 | */ | |
6b80053d | 542 | static int close_blocks(u64 blocknr, u64 other, u32 blocksize) |
6702ed49 | 543 | { |
6b80053d | 544 | if (blocknr < other && other - (blocknr + blocksize) < 32768) |
6702ed49 | 545 | return 1; |
6b80053d | 546 | if (blocknr > other && blocknr - (other + blocksize) < 32768) |
6702ed49 CM |
547 | return 1; |
548 | return 0; | |
549 | } | |
550 | ||
081e9573 CM |
551 | /* |
552 | * compare two keys in a memcmp fashion | |
553 | */ | |
554 | static int comp_keys(struct btrfs_disk_key *disk, struct btrfs_key *k2) | |
555 | { | |
556 | struct btrfs_key k1; | |
557 | ||
558 | btrfs_disk_key_to_cpu(&k1, disk); | |
559 | ||
20736aba | 560 | return btrfs_comp_cpu_keys(&k1, k2); |
081e9573 CM |
561 | } |
562 | ||
f3465ca4 JB |
563 | /* |
564 | * same as comp_keys only with two btrfs_key's | |
565 | */ | |
5d4f98a2 | 566 | int btrfs_comp_cpu_keys(struct btrfs_key *k1, struct btrfs_key *k2) |
f3465ca4 JB |
567 | { |
568 | if (k1->objectid > k2->objectid) | |
569 | return 1; | |
570 | if (k1->objectid < k2->objectid) | |
571 | return -1; | |
572 | if (k1->type > k2->type) | |
573 | return 1; | |
574 | if (k1->type < k2->type) | |
575 | return -1; | |
576 | if (k1->offset > k2->offset) | |
577 | return 1; | |
578 | if (k1->offset < k2->offset) | |
579 | return -1; | |
580 | return 0; | |
581 | } | |
081e9573 | 582 | |
d352ac68 CM |
583 | /* |
584 | * this is used by the defrag code to go through all the | |
585 | * leaves pointed to by a node and reallocate them so that | |
586 | * disk order is close to key order | |
587 | */ | |
6702ed49 | 588 | int btrfs_realloc_node(struct btrfs_trans_handle *trans, |
5f39d397 | 589 | struct btrfs_root *root, struct extent_buffer *parent, |
a6b6e75e CM |
590 | int start_slot, int cache_only, u64 *last_ret, |
591 | struct btrfs_key *progress) | |
6702ed49 | 592 | { |
6b80053d | 593 | struct extent_buffer *cur; |
6702ed49 | 594 | u64 blocknr; |
ca7a79ad | 595 | u64 gen; |
e9d0b13b CM |
596 | u64 search_start = *last_ret; |
597 | u64 last_block = 0; | |
6702ed49 CM |
598 | u64 other; |
599 | u32 parent_nritems; | |
6702ed49 CM |
600 | int end_slot; |
601 | int i; | |
602 | int err = 0; | |
f2183bde | 603 | int parent_level; |
6b80053d CM |
604 | int uptodate; |
605 | u32 blocksize; | |
081e9573 CM |
606 | int progress_passed = 0; |
607 | struct btrfs_disk_key disk_key; | |
6702ed49 | 608 | |
5708b959 CM |
609 | parent_level = btrfs_header_level(parent); |
610 | if (cache_only && parent_level != 1) | |
611 | return 0; | |
612 | ||
d397712b | 613 | if (trans->transaction != root->fs_info->running_transaction) |
6702ed49 | 614 | WARN_ON(1); |
d397712b | 615 | if (trans->transid != root->fs_info->generation) |
6702ed49 | 616 | WARN_ON(1); |
86479a04 | 617 | |
6b80053d | 618 | parent_nritems = btrfs_header_nritems(parent); |
6b80053d | 619 | blocksize = btrfs_level_size(root, parent_level - 1); |
6702ed49 CM |
620 | end_slot = parent_nritems; |
621 | ||
622 | if (parent_nritems == 1) | |
623 | return 0; | |
624 | ||
b4ce94de CM |
625 | btrfs_set_lock_blocking(parent); |
626 | ||
6702ed49 CM |
627 | for (i = start_slot; i < end_slot; i++) { |
628 | int close = 1; | |
a6b6e75e | 629 | |
5708b959 CM |
630 | if (!parent->map_token) { |
631 | map_extent_buffer(parent, | |
632 | btrfs_node_key_ptr_offset(i), | |
633 | sizeof(struct btrfs_key_ptr), | |
634 | &parent->map_token, &parent->kaddr, | |
635 | &parent->map_start, &parent->map_len, | |
636 | KM_USER1); | |
637 | } | |
081e9573 CM |
638 | btrfs_node_key(parent, &disk_key, i); |
639 | if (!progress_passed && comp_keys(&disk_key, progress) < 0) | |
640 | continue; | |
641 | ||
642 | progress_passed = 1; | |
6b80053d | 643 | blocknr = btrfs_node_blockptr(parent, i); |
ca7a79ad | 644 | gen = btrfs_node_ptr_generation(parent, i); |
e9d0b13b CM |
645 | if (last_block == 0) |
646 | last_block = blocknr; | |
5708b959 | 647 | |
6702ed49 | 648 | if (i > 0) { |
6b80053d CM |
649 | other = btrfs_node_blockptr(parent, i - 1); |
650 | close = close_blocks(blocknr, other, blocksize); | |
6702ed49 | 651 | } |
0ef3e66b | 652 | if (!close && i < end_slot - 2) { |
6b80053d CM |
653 | other = btrfs_node_blockptr(parent, i + 1); |
654 | close = close_blocks(blocknr, other, blocksize); | |
6702ed49 | 655 | } |
e9d0b13b CM |
656 | if (close) { |
657 | last_block = blocknr; | |
6702ed49 | 658 | continue; |
e9d0b13b | 659 | } |
5708b959 CM |
660 | if (parent->map_token) { |
661 | unmap_extent_buffer(parent, parent->map_token, | |
662 | KM_USER1); | |
663 | parent->map_token = NULL; | |
664 | } | |
6702ed49 | 665 | |
6b80053d CM |
666 | cur = btrfs_find_tree_block(root, blocknr, blocksize); |
667 | if (cur) | |
1259ab75 | 668 | uptodate = btrfs_buffer_uptodate(cur, gen); |
6b80053d CM |
669 | else |
670 | uptodate = 0; | |
5708b959 | 671 | if (!cur || !uptodate) { |
6702ed49 | 672 | if (cache_only) { |
6b80053d | 673 | free_extent_buffer(cur); |
6702ed49 CM |
674 | continue; |
675 | } | |
6b80053d CM |
676 | if (!cur) { |
677 | cur = read_tree_block(root, blocknr, | |
ca7a79ad | 678 | blocksize, gen); |
6b80053d | 679 | } else if (!uptodate) { |
ca7a79ad | 680 | btrfs_read_buffer(cur, gen); |
f2183bde | 681 | } |
6702ed49 | 682 | } |
e9d0b13b | 683 | if (search_start == 0) |
6b80053d | 684 | search_start = last_block; |
e9d0b13b | 685 | |
e7a84565 | 686 | btrfs_tree_lock(cur); |
b4ce94de | 687 | btrfs_set_lock_blocking(cur); |
6b80053d | 688 | err = __btrfs_cow_block(trans, root, cur, parent, i, |
e7a84565 | 689 | &cur, search_start, |
6b80053d | 690 | min(16 * blocksize, |
9fa8cfe7 | 691 | (end_slot - i) * blocksize)); |
252c38f0 | 692 | if (err) { |
e7a84565 | 693 | btrfs_tree_unlock(cur); |
6b80053d | 694 | free_extent_buffer(cur); |
6702ed49 | 695 | break; |
252c38f0 | 696 | } |
e7a84565 CM |
697 | search_start = cur->start; |
698 | last_block = cur->start; | |
f2183bde | 699 | *last_ret = search_start; |
e7a84565 CM |
700 | btrfs_tree_unlock(cur); |
701 | free_extent_buffer(cur); | |
6702ed49 | 702 | } |
5708b959 CM |
703 | if (parent->map_token) { |
704 | unmap_extent_buffer(parent, parent->map_token, | |
705 | KM_USER1); | |
706 | parent->map_token = NULL; | |
707 | } | |
6702ed49 CM |
708 | return err; |
709 | } | |
710 | ||
74123bd7 CM |
711 | /* |
712 | * The leaf data grows from end-to-front in the node. | |
713 | * this returns the address of the start of the last item, | |
714 | * which is the stop of the leaf data stack | |
715 | */ | |
123abc88 | 716 | static inline unsigned int leaf_data_end(struct btrfs_root *root, |
5f39d397 | 717 | struct extent_buffer *leaf) |
be0e5c09 | 718 | { |
5f39d397 | 719 | u32 nr = btrfs_header_nritems(leaf); |
be0e5c09 | 720 | if (nr == 0) |
123abc88 | 721 | return BTRFS_LEAF_DATA_SIZE(root); |
5f39d397 | 722 | return btrfs_item_offset_nr(leaf, nr - 1); |
be0e5c09 CM |
723 | } |
724 | ||
d352ac68 CM |
725 | /* |
726 | * extra debugging checks to make sure all the items in a key are | |
727 | * well formed and in the proper order | |
728 | */ | |
123abc88 CM |
729 | static int check_node(struct btrfs_root *root, struct btrfs_path *path, |
730 | int level) | |
aa5d6bed | 731 | { |
5f39d397 CM |
732 | struct extent_buffer *parent = NULL; |
733 | struct extent_buffer *node = path->nodes[level]; | |
734 | struct btrfs_disk_key parent_key; | |
735 | struct btrfs_disk_key node_key; | |
aa5d6bed | 736 | int parent_slot; |
8d7be552 CM |
737 | int slot; |
738 | struct btrfs_key cpukey; | |
5f39d397 | 739 | u32 nritems = btrfs_header_nritems(node); |
aa5d6bed CM |
740 | |
741 | if (path->nodes[level + 1]) | |
5f39d397 | 742 | parent = path->nodes[level + 1]; |
a1f39630 | 743 | |
8d7be552 | 744 | slot = path->slots[level]; |
7518a238 CM |
745 | BUG_ON(nritems == 0); |
746 | if (parent) { | |
a1f39630 | 747 | parent_slot = path->slots[level + 1]; |
5f39d397 CM |
748 | btrfs_node_key(parent, &parent_key, parent_slot); |
749 | btrfs_node_key(node, &node_key, 0); | |
750 | BUG_ON(memcmp(&parent_key, &node_key, | |
e2fa7227 | 751 | sizeof(struct btrfs_disk_key))); |
1d4f8a0c | 752 | BUG_ON(btrfs_node_blockptr(parent, parent_slot) != |
db94535d | 753 | btrfs_header_bytenr(node)); |
aa5d6bed | 754 | } |
123abc88 | 755 | BUG_ON(nritems > BTRFS_NODEPTRS_PER_BLOCK(root)); |
8d7be552 | 756 | if (slot != 0) { |
5f39d397 CM |
757 | btrfs_node_key_to_cpu(node, &cpukey, slot - 1); |
758 | btrfs_node_key(node, &node_key, slot); | |
759 | BUG_ON(comp_keys(&node_key, &cpukey) <= 0); | |
8d7be552 CM |
760 | } |
761 | if (slot < nritems - 1) { | |
5f39d397 CM |
762 | btrfs_node_key_to_cpu(node, &cpukey, slot + 1); |
763 | btrfs_node_key(node, &node_key, slot); | |
764 | BUG_ON(comp_keys(&node_key, &cpukey) >= 0); | |
aa5d6bed CM |
765 | } |
766 | return 0; | |
767 | } | |
768 | ||
d352ac68 CM |
769 | /* |
770 | * extra checking to make sure all the items in a leaf are | |
771 | * well formed and in the proper order | |
772 | */ | |
123abc88 CM |
773 | static int check_leaf(struct btrfs_root *root, struct btrfs_path *path, |
774 | int level) | |
aa5d6bed | 775 | { |
5f39d397 CM |
776 | struct extent_buffer *leaf = path->nodes[level]; |
777 | struct extent_buffer *parent = NULL; | |
aa5d6bed | 778 | int parent_slot; |
8d7be552 | 779 | struct btrfs_key cpukey; |
5f39d397 CM |
780 | struct btrfs_disk_key parent_key; |
781 | struct btrfs_disk_key leaf_key; | |
782 | int slot = path->slots[0]; | |
8d7be552 | 783 | |
5f39d397 | 784 | u32 nritems = btrfs_header_nritems(leaf); |
aa5d6bed CM |
785 | |
786 | if (path->nodes[level + 1]) | |
5f39d397 | 787 | parent = path->nodes[level + 1]; |
7518a238 CM |
788 | |
789 | if (nritems == 0) | |
790 | return 0; | |
791 | ||
792 | if (parent) { | |
a1f39630 | 793 | parent_slot = path->slots[level + 1]; |
5f39d397 CM |
794 | btrfs_node_key(parent, &parent_key, parent_slot); |
795 | btrfs_item_key(leaf, &leaf_key, 0); | |
6702ed49 | 796 | |
5f39d397 | 797 | BUG_ON(memcmp(&parent_key, &leaf_key, |
e2fa7227 | 798 | sizeof(struct btrfs_disk_key))); |
1d4f8a0c | 799 | BUG_ON(btrfs_node_blockptr(parent, parent_slot) != |
db94535d | 800 | btrfs_header_bytenr(leaf)); |
5f39d397 | 801 | } |
5f39d397 CM |
802 | if (slot != 0 && slot < nritems - 1) { |
803 | btrfs_item_key(leaf, &leaf_key, slot); | |
804 | btrfs_item_key_to_cpu(leaf, &cpukey, slot - 1); | |
805 | if (comp_keys(&leaf_key, &cpukey) <= 0) { | |
806 | btrfs_print_leaf(root, leaf); | |
d397712b | 807 | printk(KERN_CRIT "slot %d offset bad key\n", slot); |
5f39d397 CM |
808 | BUG_ON(1); |
809 | } | |
810 | if (btrfs_item_offset_nr(leaf, slot - 1) != | |
811 | btrfs_item_end_nr(leaf, slot)) { | |
812 | btrfs_print_leaf(root, leaf); | |
d397712b | 813 | printk(KERN_CRIT "slot %d offset bad\n", slot); |
5f39d397 CM |
814 | BUG_ON(1); |
815 | } | |
8d7be552 CM |
816 | } |
817 | if (slot < nritems - 1) { | |
5f39d397 CM |
818 | btrfs_item_key(leaf, &leaf_key, slot); |
819 | btrfs_item_key_to_cpu(leaf, &cpukey, slot + 1); | |
820 | BUG_ON(comp_keys(&leaf_key, &cpukey) >= 0); | |
821 | if (btrfs_item_offset_nr(leaf, slot) != | |
822 | btrfs_item_end_nr(leaf, slot + 1)) { | |
823 | btrfs_print_leaf(root, leaf); | |
d397712b | 824 | printk(KERN_CRIT "slot %d offset bad\n", slot); |
5f39d397 CM |
825 | BUG_ON(1); |
826 | } | |
aa5d6bed | 827 | } |
5f39d397 CM |
828 | BUG_ON(btrfs_item_offset_nr(leaf, 0) + |
829 | btrfs_item_size_nr(leaf, 0) != BTRFS_LEAF_DATA_SIZE(root)); | |
aa5d6bed CM |
830 | return 0; |
831 | } | |
832 | ||
d397712b | 833 | static noinline int check_block(struct btrfs_root *root, |
98ed5174 | 834 | struct btrfs_path *path, int level) |
aa5d6bed | 835 | { |
85d824c4 | 836 | return 0; |
aa5d6bed | 837 | if (level == 0) |
123abc88 CM |
838 | return check_leaf(root, path, level); |
839 | return check_node(root, path, level); | |
aa5d6bed CM |
840 | } |
841 | ||
74123bd7 | 842 | /* |
5f39d397 CM |
843 | * search for key in the extent_buffer. The items start at offset p, |
844 | * and they are item_size apart. There are 'max' items in p. | |
845 | * | |
74123bd7 CM |
846 | * the slot in the array is returned via slot, and it points to |
847 | * the place where you would insert key if it is not found in | |
848 | * the array. | |
849 | * | |
850 | * slot may point to max if the key is bigger than all of the keys | |
851 | */ | |
e02119d5 CM |
852 | static noinline int generic_bin_search(struct extent_buffer *eb, |
853 | unsigned long p, | |
854 | int item_size, struct btrfs_key *key, | |
855 | int max, int *slot) | |
be0e5c09 CM |
856 | { |
857 | int low = 0; | |
858 | int high = max; | |
859 | int mid; | |
860 | int ret; | |
479965d6 | 861 | struct btrfs_disk_key *tmp = NULL; |
5f39d397 CM |
862 | struct btrfs_disk_key unaligned; |
863 | unsigned long offset; | |
864 | char *map_token = NULL; | |
865 | char *kaddr = NULL; | |
866 | unsigned long map_start = 0; | |
867 | unsigned long map_len = 0; | |
479965d6 | 868 | int err; |
be0e5c09 | 869 | |
d397712b | 870 | while (low < high) { |
be0e5c09 | 871 | mid = (low + high) / 2; |
5f39d397 CM |
872 | offset = p + mid * item_size; |
873 | ||
874 | if (!map_token || offset < map_start || | |
875 | (offset + sizeof(struct btrfs_disk_key)) > | |
876 | map_start + map_len) { | |
479965d6 | 877 | if (map_token) { |
5f39d397 | 878 | unmap_extent_buffer(eb, map_token, KM_USER0); |
479965d6 CM |
879 | map_token = NULL; |
880 | } | |
934d375b CM |
881 | |
882 | err = map_private_extent_buffer(eb, offset, | |
479965d6 CM |
883 | sizeof(struct btrfs_disk_key), |
884 | &map_token, &kaddr, | |
885 | &map_start, &map_len, KM_USER0); | |
886 | ||
887 | if (!err) { | |
888 | tmp = (struct btrfs_disk_key *)(kaddr + offset - | |
889 | map_start); | |
890 | } else { | |
891 | read_extent_buffer(eb, &unaligned, | |
892 | offset, sizeof(unaligned)); | |
893 | tmp = &unaligned; | |
894 | } | |
5f39d397 | 895 | |
5f39d397 CM |
896 | } else { |
897 | tmp = (struct btrfs_disk_key *)(kaddr + offset - | |
898 | map_start); | |
899 | } | |
be0e5c09 CM |
900 | ret = comp_keys(tmp, key); |
901 | ||
902 | if (ret < 0) | |
903 | low = mid + 1; | |
904 | else if (ret > 0) | |
905 | high = mid; | |
906 | else { | |
907 | *slot = mid; | |
479965d6 CM |
908 | if (map_token) |
909 | unmap_extent_buffer(eb, map_token, KM_USER0); | |
be0e5c09 CM |
910 | return 0; |
911 | } | |
912 | } | |
913 | *slot = low; | |
5f39d397 CM |
914 | if (map_token) |
915 | unmap_extent_buffer(eb, map_token, KM_USER0); | |
be0e5c09 CM |
916 | return 1; |
917 | } | |
918 | ||
97571fd0 CM |
919 | /* |
920 | * simple bin_search frontend that does the right thing for | |
921 | * leaves vs nodes | |
922 | */ | |
5f39d397 CM |
923 | static int bin_search(struct extent_buffer *eb, struct btrfs_key *key, |
924 | int level, int *slot) | |
be0e5c09 | 925 | { |
5f39d397 CM |
926 | if (level == 0) { |
927 | return generic_bin_search(eb, | |
928 | offsetof(struct btrfs_leaf, items), | |
0783fcfc | 929 | sizeof(struct btrfs_item), |
5f39d397 | 930 | key, btrfs_header_nritems(eb), |
7518a238 | 931 | slot); |
be0e5c09 | 932 | } else { |
5f39d397 CM |
933 | return generic_bin_search(eb, |
934 | offsetof(struct btrfs_node, ptrs), | |
123abc88 | 935 | sizeof(struct btrfs_key_ptr), |
5f39d397 | 936 | key, btrfs_header_nritems(eb), |
7518a238 | 937 | slot); |
be0e5c09 CM |
938 | } |
939 | return -1; | |
940 | } | |
941 | ||
5d4f98a2 YZ |
942 | int btrfs_bin_search(struct extent_buffer *eb, struct btrfs_key *key, |
943 | int level, int *slot) | |
944 | { | |
945 | return bin_search(eb, key, level, slot); | |
946 | } | |
947 | ||
d352ac68 CM |
948 | /* given a node and slot number, this reads the blocks it points to. The |
949 | * extent buffer is returned with a reference taken (but unlocked). | |
950 | * NULL is returned on error. | |
951 | */ | |
e02119d5 | 952 | static noinline struct extent_buffer *read_node_slot(struct btrfs_root *root, |
5f39d397 | 953 | struct extent_buffer *parent, int slot) |
bb803951 | 954 | { |
ca7a79ad | 955 | int level = btrfs_header_level(parent); |
bb803951 CM |
956 | if (slot < 0) |
957 | return NULL; | |
5f39d397 | 958 | if (slot >= btrfs_header_nritems(parent)) |
bb803951 | 959 | return NULL; |
ca7a79ad CM |
960 | |
961 | BUG_ON(level == 0); | |
962 | ||
db94535d | 963 | return read_tree_block(root, btrfs_node_blockptr(parent, slot), |
ca7a79ad CM |
964 | btrfs_level_size(root, level - 1), |
965 | btrfs_node_ptr_generation(parent, slot)); | |
bb803951 CM |
966 | } |
967 | ||
d352ac68 CM |
968 | /* |
969 | * node level balancing, used to make sure nodes are in proper order for | |
970 | * item deletion. We balance from the top down, so we have to make sure | |
971 | * that a deletion won't leave an node completely empty later on. | |
972 | */ | |
e02119d5 | 973 | static noinline int balance_level(struct btrfs_trans_handle *trans, |
98ed5174 CM |
974 | struct btrfs_root *root, |
975 | struct btrfs_path *path, int level) | |
bb803951 | 976 | { |
5f39d397 CM |
977 | struct extent_buffer *right = NULL; |
978 | struct extent_buffer *mid; | |
979 | struct extent_buffer *left = NULL; | |
980 | struct extent_buffer *parent = NULL; | |
bb803951 CM |
981 | int ret = 0; |
982 | int wret; | |
983 | int pslot; | |
bb803951 | 984 | int orig_slot = path->slots[level]; |
54aa1f4d | 985 | int err_on_enospc = 0; |
79f95c82 | 986 | u64 orig_ptr; |
bb803951 CM |
987 | |
988 | if (level == 0) | |
989 | return 0; | |
990 | ||
5f39d397 | 991 | mid = path->nodes[level]; |
b4ce94de | 992 | |
925baedd | 993 | WARN_ON(!path->locks[level]); |
7bb86316 CM |
994 | WARN_ON(btrfs_header_generation(mid) != trans->transid); |
995 | ||
1d4f8a0c | 996 | orig_ptr = btrfs_node_blockptr(mid, orig_slot); |
79f95c82 | 997 | |
234b63a0 | 998 | if (level < BTRFS_MAX_LEVEL - 1) |
5f39d397 | 999 | parent = path->nodes[level + 1]; |
bb803951 CM |
1000 | pslot = path->slots[level + 1]; |
1001 | ||
40689478 CM |
1002 | /* |
1003 | * deal with the case where there is only one pointer in the root | |
1004 | * by promoting the node below to a root | |
1005 | */ | |
5f39d397 CM |
1006 | if (!parent) { |
1007 | struct extent_buffer *child; | |
bb803951 | 1008 | |
5f39d397 | 1009 | if (btrfs_header_nritems(mid) != 1) |
bb803951 CM |
1010 | return 0; |
1011 | ||
1012 | /* promote the child to a root */ | |
5f39d397 | 1013 | child = read_node_slot(root, mid, 0); |
7951f3ce | 1014 | BUG_ON(!child); |
925baedd | 1015 | btrfs_tree_lock(child); |
b4ce94de | 1016 | btrfs_set_lock_blocking(child); |
9fa8cfe7 | 1017 | ret = btrfs_cow_block(trans, root, child, mid, 0, &child); |
2f375ab9 Y |
1018 | BUG_ON(ret); |
1019 | ||
925baedd | 1020 | spin_lock(&root->node_lock); |
bb803951 | 1021 | root->node = child; |
925baedd CM |
1022 | spin_unlock(&root->node_lock); |
1023 | ||
0b86a832 | 1024 | add_root_to_dirty_list(root); |
925baedd | 1025 | btrfs_tree_unlock(child); |
b4ce94de | 1026 | |
925baedd | 1027 | path->locks[level] = 0; |
bb803951 | 1028 | path->nodes[level] = NULL; |
5f39d397 | 1029 | clean_tree_block(trans, root, mid); |
925baedd | 1030 | btrfs_tree_unlock(mid); |
bb803951 | 1031 | /* once for the path */ |
5f39d397 | 1032 | free_extent_buffer(mid); |
7bb86316 | 1033 | ret = btrfs_free_extent(trans, root, mid->start, mid->len, |
5d4f98a2 | 1034 | 0, root->root_key.objectid, level, 1); |
bb803951 | 1035 | /* once for the root ptr */ |
5f39d397 | 1036 | free_extent_buffer(mid); |
db94535d | 1037 | return ret; |
bb803951 | 1038 | } |
5f39d397 | 1039 | if (btrfs_header_nritems(mid) > |
123abc88 | 1040 | BTRFS_NODEPTRS_PER_BLOCK(root) / 4) |
bb803951 CM |
1041 | return 0; |
1042 | ||
5f39d397 | 1043 | if (btrfs_header_nritems(mid) < 2) |
54aa1f4d CM |
1044 | err_on_enospc = 1; |
1045 | ||
5f39d397 CM |
1046 | left = read_node_slot(root, parent, pslot - 1); |
1047 | if (left) { | |
925baedd | 1048 | btrfs_tree_lock(left); |
b4ce94de | 1049 | btrfs_set_lock_blocking(left); |
5f39d397 | 1050 | wret = btrfs_cow_block(trans, root, left, |
9fa8cfe7 | 1051 | parent, pslot - 1, &left); |
54aa1f4d CM |
1052 | if (wret) { |
1053 | ret = wret; | |
1054 | goto enospc; | |
1055 | } | |
2cc58cf2 | 1056 | } |
5f39d397 CM |
1057 | right = read_node_slot(root, parent, pslot + 1); |
1058 | if (right) { | |
925baedd | 1059 | btrfs_tree_lock(right); |
b4ce94de | 1060 | btrfs_set_lock_blocking(right); |
5f39d397 | 1061 | wret = btrfs_cow_block(trans, root, right, |
9fa8cfe7 | 1062 | parent, pslot + 1, &right); |
2cc58cf2 CM |
1063 | if (wret) { |
1064 | ret = wret; | |
1065 | goto enospc; | |
1066 | } | |
1067 | } | |
1068 | ||
1069 | /* first, try to make some room in the middle buffer */ | |
5f39d397 CM |
1070 | if (left) { |
1071 | orig_slot += btrfs_header_nritems(left); | |
bce4eae9 | 1072 | wret = push_node_left(trans, root, left, mid, 1); |
79f95c82 CM |
1073 | if (wret < 0) |
1074 | ret = wret; | |
5f39d397 | 1075 | if (btrfs_header_nritems(mid) < 2) |
54aa1f4d | 1076 | err_on_enospc = 1; |
bb803951 | 1077 | } |
79f95c82 CM |
1078 | |
1079 | /* | |
1080 | * then try to empty the right most buffer into the middle | |
1081 | */ | |
5f39d397 | 1082 | if (right) { |
971a1f66 | 1083 | wret = push_node_left(trans, root, mid, right, 1); |
54aa1f4d | 1084 | if (wret < 0 && wret != -ENOSPC) |
79f95c82 | 1085 | ret = wret; |
5f39d397 | 1086 | if (btrfs_header_nritems(right) == 0) { |
db94535d CM |
1087 | u64 bytenr = right->start; |
1088 | u32 blocksize = right->len; | |
1089 | ||
5f39d397 | 1090 | clean_tree_block(trans, root, right); |
925baedd | 1091 | btrfs_tree_unlock(right); |
5f39d397 | 1092 | free_extent_buffer(right); |
bb803951 | 1093 | right = NULL; |
e089f05c CM |
1094 | wret = del_ptr(trans, root, path, level + 1, pslot + |
1095 | 1); | |
bb803951 CM |
1096 | if (wret) |
1097 | ret = wret; | |
db94535d | 1098 | wret = btrfs_free_extent(trans, root, bytenr, |
5d4f98a2 YZ |
1099 | blocksize, 0, |
1100 | root->root_key.objectid, | |
1101 | level, 0); | |
bb803951 CM |
1102 | if (wret) |
1103 | ret = wret; | |
1104 | } else { | |
5f39d397 CM |
1105 | struct btrfs_disk_key right_key; |
1106 | btrfs_node_key(right, &right_key, 0); | |
1107 | btrfs_set_node_key(parent, &right_key, pslot + 1); | |
1108 | btrfs_mark_buffer_dirty(parent); | |
bb803951 CM |
1109 | } |
1110 | } | |
5f39d397 | 1111 | if (btrfs_header_nritems(mid) == 1) { |
79f95c82 CM |
1112 | /* |
1113 | * we're not allowed to leave a node with one item in the | |
1114 | * tree during a delete. A deletion from lower in the tree | |
1115 | * could try to delete the only pointer in this node. | |
1116 | * So, pull some keys from the left. | |
1117 | * There has to be a left pointer at this point because | |
1118 | * otherwise we would have pulled some pointers from the | |
1119 | * right | |
1120 | */ | |
5f39d397 CM |
1121 | BUG_ON(!left); |
1122 | wret = balance_node_right(trans, root, mid, left); | |
54aa1f4d | 1123 | if (wret < 0) { |
79f95c82 | 1124 | ret = wret; |
54aa1f4d CM |
1125 | goto enospc; |
1126 | } | |
bce4eae9 CM |
1127 | if (wret == 1) { |
1128 | wret = push_node_left(trans, root, left, mid, 1); | |
1129 | if (wret < 0) | |
1130 | ret = wret; | |
1131 | } | |
79f95c82 CM |
1132 | BUG_ON(wret == 1); |
1133 | } | |
5f39d397 | 1134 | if (btrfs_header_nritems(mid) == 0) { |
79f95c82 | 1135 | /* we've managed to empty the middle node, drop it */ |
db94535d CM |
1136 | u64 bytenr = mid->start; |
1137 | u32 blocksize = mid->len; | |
925baedd | 1138 | |
5f39d397 | 1139 | clean_tree_block(trans, root, mid); |
925baedd | 1140 | btrfs_tree_unlock(mid); |
5f39d397 | 1141 | free_extent_buffer(mid); |
bb803951 | 1142 | mid = NULL; |
e089f05c | 1143 | wret = del_ptr(trans, root, path, level + 1, pslot); |
bb803951 CM |
1144 | if (wret) |
1145 | ret = wret; | |
7bb86316 | 1146 | wret = btrfs_free_extent(trans, root, bytenr, blocksize, |
5d4f98a2 YZ |
1147 | 0, root->root_key.objectid, |
1148 | level, 0); | |
bb803951 CM |
1149 | if (wret) |
1150 | ret = wret; | |
79f95c82 CM |
1151 | } else { |
1152 | /* update the parent key to reflect our changes */ | |
5f39d397 CM |
1153 | struct btrfs_disk_key mid_key; |
1154 | btrfs_node_key(mid, &mid_key, 0); | |
1155 | btrfs_set_node_key(parent, &mid_key, pslot); | |
1156 | btrfs_mark_buffer_dirty(parent); | |
79f95c82 | 1157 | } |
bb803951 | 1158 | |
79f95c82 | 1159 | /* update the path */ |
5f39d397 CM |
1160 | if (left) { |
1161 | if (btrfs_header_nritems(left) > orig_slot) { | |
1162 | extent_buffer_get(left); | |
925baedd | 1163 | /* left was locked after cow */ |
5f39d397 | 1164 | path->nodes[level] = left; |
bb803951 CM |
1165 | path->slots[level + 1] -= 1; |
1166 | path->slots[level] = orig_slot; | |
925baedd CM |
1167 | if (mid) { |
1168 | btrfs_tree_unlock(mid); | |
5f39d397 | 1169 | free_extent_buffer(mid); |
925baedd | 1170 | } |
bb803951 | 1171 | } else { |
5f39d397 | 1172 | orig_slot -= btrfs_header_nritems(left); |
bb803951 CM |
1173 | path->slots[level] = orig_slot; |
1174 | } | |
1175 | } | |
79f95c82 | 1176 | /* double check we haven't messed things up */ |
123abc88 | 1177 | check_block(root, path, level); |
e20d96d6 | 1178 | if (orig_ptr != |
5f39d397 | 1179 | btrfs_node_blockptr(path->nodes[level], path->slots[level])) |
79f95c82 | 1180 | BUG(); |
54aa1f4d | 1181 | enospc: |
925baedd CM |
1182 | if (right) { |
1183 | btrfs_tree_unlock(right); | |
5f39d397 | 1184 | free_extent_buffer(right); |
925baedd CM |
1185 | } |
1186 | if (left) { | |
1187 | if (path->nodes[level] != left) | |
1188 | btrfs_tree_unlock(left); | |
5f39d397 | 1189 | free_extent_buffer(left); |
925baedd | 1190 | } |
bb803951 CM |
1191 | return ret; |
1192 | } | |
1193 | ||
d352ac68 CM |
1194 | /* Node balancing for insertion. Here we only split or push nodes around |
1195 | * when they are completely full. This is also done top down, so we | |
1196 | * have to be pessimistic. | |
1197 | */ | |
d397712b | 1198 | static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans, |
98ed5174 CM |
1199 | struct btrfs_root *root, |
1200 | struct btrfs_path *path, int level) | |
e66f709b | 1201 | { |
5f39d397 CM |
1202 | struct extent_buffer *right = NULL; |
1203 | struct extent_buffer *mid; | |
1204 | struct extent_buffer *left = NULL; | |
1205 | struct extent_buffer *parent = NULL; | |
e66f709b CM |
1206 | int ret = 0; |
1207 | int wret; | |
1208 | int pslot; | |
1209 | int orig_slot = path->slots[level]; | |
1210 | u64 orig_ptr; | |
1211 | ||
1212 | if (level == 0) | |
1213 | return 1; | |
1214 | ||
5f39d397 | 1215 | mid = path->nodes[level]; |
7bb86316 | 1216 | WARN_ON(btrfs_header_generation(mid) != trans->transid); |
e66f709b CM |
1217 | orig_ptr = btrfs_node_blockptr(mid, orig_slot); |
1218 | ||
1219 | if (level < BTRFS_MAX_LEVEL - 1) | |
5f39d397 | 1220 | parent = path->nodes[level + 1]; |
e66f709b CM |
1221 | pslot = path->slots[level + 1]; |
1222 | ||
5f39d397 | 1223 | if (!parent) |
e66f709b | 1224 | return 1; |
e66f709b | 1225 | |
5f39d397 | 1226 | left = read_node_slot(root, parent, pslot - 1); |
e66f709b CM |
1227 | |
1228 | /* first, try to make some room in the middle buffer */ | |
5f39d397 | 1229 | if (left) { |
e66f709b | 1230 | u32 left_nr; |
925baedd CM |
1231 | |
1232 | btrfs_tree_lock(left); | |
b4ce94de CM |
1233 | btrfs_set_lock_blocking(left); |
1234 | ||
5f39d397 | 1235 | left_nr = btrfs_header_nritems(left); |
33ade1f8 CM |
1236 | if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) { |
1237 | wret = 1; | |
1238 | } else { | |
5f39d397 | 1239 | ret = btrfs_cow_block(trans, root, left, parent, |
9fa8cfe7 | 1240 | pslot - 1, &left); |
54aa1f4d CM |
1241 | if (ret) |
1242 | wret = 1; | |
1243 | else { | |
54aa1f4d | 1244 | wret = push_node_left(trans, root, |
971a1f66 | 1245 | left, mid, 0); |
54aa1f4d | 1246 | } |
33ade1f8 | 1247 | } |
e66f709b CM |
1248 | if (wret < 0) |
1249 | ret = wret; | |
1250 | if (wret == 0) { | |
5f39d397 | 1251 | struct btrfs_disk_key disk_key; |
e66f709b | 1252 | orig_slot += left_nr; |
5f39d397 CM |
1253 | btrfs_node_key(mid, &disk_key, 0); |
1254 | btrfs_set_node_key(parent, &disk_key, pslot); | |
1255 | btrfs_mark_buffer_dirty(parent); | |
1256 | if (btrfs_header_nritems(left) > orig_slot) { | |
1257 | path->nodes[level] = left; | |
e66f709b CM |
1258 | path->slots[level + 1] -= 1; |
1259 | path->slots[level] = orig_slot; | |
925baedd | 1260 | btrfs_tree_unlock(mid); |
5f39d397 | 1261 | free_extent_buffer(mid); |
e66f709b CM |
1262 | } else { |
1263 | orig_slot -= | |
5f39d397 | 1264 | btrfs_header_nritems(left); |
e66f709b | 1265 | path->slots[level] = orig_slot; |
925baedd | 1266 | btrfs_tree_unlock(left); |
5f39d397 | 1267 | free_extent_buffer(left); |
e66f709b | 1268 | } |
e66f709b CM |
1269 | return 0; |
1270 | } | |
925baedd | 1271 | btrfs_tree_unlock(left); |
5f39d397 | 1272 | free_extent_buffer(left); |
e66f709b | 1273 | } |
925baedd | 1274 | right = read_node_slot(root, parent, pslot + 1); |
e66f709b CM |
1275 | |
1276 | /* | |
1277 | * then try to empty the right most buffer into the middle | |
1278 | */ | |
5f39d397 | 1279 | if (right) { |
33ade1f8 | 1280 | u32 right_nr; |
b4ce94de | 1281 | |
925baedd | 1282 | btrfs_tree_lock(right); |
b4ce94de CM |
1283 | btrfs_set_lock_blocking(right); |
1284 | ||
5f39d397 | 1285 | right_nr = btrfs_header_nritems(right); |
33ade1f8 CM |
1286 | if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) { |
1287 | wret = 1; | |
1288 | } else { | |
5f39d397 CM |
1289 | ret = btrfs_cow_block(trans, root, right, |
1290 | parent, pslot + 1, | |
9fa8cfe7 | 1291 | &right); |
54aa1f4d CM |
1292 | if (ret) |
1293 | wret = 1; | |
1294 | else { | |
54aa1f4d | 1295 | wret = balance_node_right(trans, root, |
5f39d397 | 1296 | right, mid); |
54aa1f4d | 1297 | } |
33ade1f8 | 1298 | } |
e66f709b CM |
1299 | if (wret < 0) |
1300 | ret = wret; | |
1301 | if (wret == 0) { | |
5f39d397 CM |
1302 | struct btrfs_disk_key disk_key; |
1303 | ||
1304 | btrfs_node_key(right, &disk_key, 0); | |
1305 | btrfs_set_node_key(parent, &disk_key, pslot + 1); | |
1306 | btrfs_mark_buffer_dirty(parent); | |
1307 | ||
1308 | if (btrfs_header_nritems(mid) <= orig_slot) { | |
1309 | path->nodes[level] = right; | |
e66f709b CM |
1310 | path->slots[level + 1] += 1; |
1311 | path->slots[level] = orig_slot - | |
5f39d397 | 1312 | btrfs_header_nritems(mid); |
925baedd | 1313 | btrfs_tree_unlock(mid); |
5f39d397 | 1314 | free_extent_buffer(mid); |
e66f709b | 1315 | } else { |
925baedd | 1316 | btrfs_tree_unlock(right); |
5f39d397 | 1317 | free_extent_buffer(right); |
e66f709b | 1318 | } |
e66f709b CM |
1319 | return 0; |
1320 | } | |
925baedd | 1321 | btrfs_tree_unlock(right); |
5f39d397 | 1322 | free_extent_buffer(right); |
e66f709b | 1323 | } |
e66f709b CM |
1324 | return 1; |
1325 | } | |
1326 | ||
3c69faec | 1327 | /* |
d352ac68 CM |
1328 | * readahead one full node of leaves, finding things that are close |
1329 | * to the block in 'slot', and triggering ra on them. | |
3c69faec | 1330 | */ |
c8c42864 CM |
1331 | static void reada_for_search(struct btrfs_root *root, |
1332 | struct btrfs_path *path, | |
1333 | int level, int slot, u64 objectid) | |
3c69faec | 1334 | { |
5f39d397 | 1335 | struct extent_buffer *node; |
01f46658 | 1336 | struct btrfs_disk_key disk_key; |
3c69faec | 1337 | u32 nritems; |
3c69faec | 1338 | u64 search; |
a7175319 | 1339 | u64 target; |
6b80053d | 1340 | u64 nread = 0; |
3c69faec | 1341 | int direction = path->reada; |
5f39d397 | 1342 | struct extent_buffer *eb; |
6b80053d CM |
1343 | u32 nr; |
1344 | u32 blocksize; | |
1345 | u32 nscan = 0; | |
db94535d | 1346 | |
a6b6e75e | 1347 | if (level != 1) |
6702ed49 CM |
1348 | return; |
1349 | ||
1350 | if (!path->nodes[level]) | |
3c69faec CM |
1351 | return; |
1352 | ||
5f39d397 | 1353 | node = path->nodes[level]; |
925baedd | 1354 | |
3c69faec | 1355 | search = btrfs_node_blockptr(node, slot); |
6b80053d CM |
1356 | blocksize = btrfs_level_size(root, level - 1); |
1357 | eb = btrfs_find_tree_block(root, search, blocksize); | |
5f39d397 CM |
1358 | if (eb) { |
1359 | free_extent_buffer(eb); | |
3c69faec CM |
1360 | return; |
1361 | } | |
1362 | ||
a7175319 | 1363 | target = search; |
6b80053d | 1364 | |
5f39d397 | 1365 | nritems = btrfs_header_nritems(node); |
6b80053d | 1366 | nr = slot; |
d397712b | 1367 | while (1) { |
6b80053d CM |
1368 | if (direction < 0) { |
1369 | if (nr == 0) | |
1370 | break; | |
1371 | nr--; | |
1372 | } else if (direction > 0) { | |
1373 | nr++; | |
1374 | if (nr >= nritems) | |
1375 | break; | |
3c69faec | 1376 | } |
01f46658 CM |
1377 | if (path->reada < 0 && objectid) { |
1378 | btrfs_node_key(node, &disk_key, nr); | |
1379 | if (btrfs_disk_key_objectid(&disk_key) != objectid) | |
1380 | break; | |
1381 | } | |
6b80053d | 1382 | search = btrfs_node_blockptr(node, nr); |
a7175319 CM |
1383 | if ((search <= target && target - search <= 65536) || |
1384 | (search > target && search - target <= 65536)) { | |
ca7a79ad CM |
1385 | readahead_tree_block(root, search, blocksize, |
1386 | btrfs_node_ptr_generation(node, nr)); | |
6b80053d CM |
1387 | nread += blocksize; |
1388 | } | |
1389 | nscan++; | |
a7175319 | 1390 | if ((nread > 65536 || nscan > 32)) |
6b80053d | 1391 | break; |
3c69faec CM |
1392 | } |
1393 | } | |
925baedd | 1394 | |
b4ce94de CM |
1395 | /* |
1396 | * returns -EAGAIN if it had to drop the path, or zero if everything was in | |
1397 | * cache | |
1398 | */ | |
1399 | static noinline int reada_for_balance(struct btrfs_root *root, | |
1400 | struct btrfs_path *path, int level) | |
1401 | { | |
1402 | int slot; | |
1403 | int nritems; | |
1404 | struct extent_buffer *parent; | |
1405 | struct extent_buffer *eb; | |
1406 | u64 gen; | |
1407 | u64 block1 = 0; | |
1408 | u64 block2 = 0; | |
1409 | int ret = 0; | |
1410 | int blocksize; | |
1411 | ||
8c594ea8 | 1412 | parent = path->nodes[level + 1]; |
b4ce94de CM |
1413 | if (!parent) |
1414 | return 0; | |
1415 | ||
1416 | nritems = btrfs_header_nritems(parent); | |
8c594ea8 | 1417 | slot = path->slots[level + 1]; |
b4ce94de CM |
1418 | blocksize = btrfs_level_size(root, level); |
1419 | ||
1420 | if (slot > 0) { | |
1421 | block1 = btrfs_node_blockptr(parent, slot - 1); | |
1422 | gen = btrfs_node_ptr_generation(parent, slot - 1); | |
1423 | eb = btrfs_find_tree_block(root, block1, blocksize); | |
1424 | if (eb && btrfs_buffer_uptodate(eb, gen)) | |
1425 | block1 = 0; | |
1426 | free_extent_buffer(eb); | |
1427 | } | |
8c594ea8 | 1428 | if (slot + 1 < nritems) { |
b4ce94de CM |
1429 | block2 = btrfs_node_blockptr(parent, slot + 1); |
1430 | gen = btrfs_node_ptr_generation(parent, slot + 1); | |
1431 | eb = btrfs_find_tree_block(root, block2, blocksize); | |
1432 | if (eb && btrfs_buffer_uptodate(eb, gen)) | |
1433 | block2 = 0; | |
1434 | free_extent_buffer(eb); | |
1435 | } | |
1436 | if (block1 || block2) { | |
1437 | ret = -EAGAIN; | |
8c594ea8 CM |
1438 | |
1439 | /* release the whole path */ | |
b4ce94de | 1440 | btrfs_release_path(root, path); |
8c594ea8 CM |
1441 | |
1442 | /* read the blocks */ | |
b4ce94de CM |
1443 | if (block1) |
1444 | readahead_tree_block(root, block1, blocksize, 0); | |
1445 | if (block2) | |
1446 | readahead_tree_block(root, block2, blocksize, 0); | |
1447 | ||
1448 | if (block1) { | |
1449 | eb = read_tree_block(root, block1, blocksize, 0); | |
1450 | free_extent_buffer(eb); | |
1451 | } | |
8c594ea8 | 1452 | if (block2) { |
b4ce94de CM |
1453 | eb = read_tree_block(root, block2, blocksize, 0); |
1454 | free_extent_buffer(eb); | |
1455 | } | |
1456 | } | |
1457 | return ret; | |
1458 | } | |
1459 | ||
1460 | ||
d352ac68 | 1461 | /* |
d397712b CM |
1462 | * when we walk down the tree, it is usually safe to unlock the higher layers |
1463 | * in the tree. The exceptions are when our path goes through slot 0, because | |
1464 | * operations on the tree might require changing key pointers higher up in the | |
1465 | * tree. | |
d352ac68 | 1466 | * |
d397712b CM |
1467 | * callers might also have set path->keep_locks, which tells this code to keep |
1468 | * the lock if the path points to the last slot in the block. This is part of | |
1469 | * walking through the tree, and selecting the next slot in the higher block. | |
d352ac68 | 1470 | * |
d397712b CM |
1471 | * lowest_unlock sets the lowest level in the tree we're allowed to unlock. so |
1472 | * if lowest_unlock is 1, level 0 won't be unlocked | |
d352ac68 | 1473 | */ |
e02119d5 CM |
1474 | static noinline void unlock_up(struct btrfs_path *path, int level, |
1475 | int lowest_unlock) | |
925baedd CM |
1476 | { |
1477 | int i; | |
1478 | int skip_level = level; | |
051e1b9f | 1479 | int no_skips = 0; |
925baedd CM |
1480 | struct extent_buffer *t; |
1481 | ||
1482 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { | |
1483 | if (!path->nodes[i]) | |
1484 | break; | |
1485 | if (!path->locks[i]) | |
1486 | break; | |
051e1b9f | 1487 | if (!no_skips && path->slots[i] == 0) { |
925baedd CM |
1488 | skip_level = i + 1; |
1489 | continue; | |
1490 | } | |
051e1b9f | 1491 | if (!no_skips && path->keep_locks) { |
925baedd CM |
1492 | u32 nritems; |
1493 | t = path->nodes[i]; | |
1494 | nritems = btrfs_header_nritems(t); | |
051e1b9f | 1495 | if (nritems < 1 || path->slots[i] >= nritems - 1) { |
925baedd CM |
1496 | skip_level = i + 1; |
1497 | continue; | |
1498 | } | |
1499 | } | |
051e1b9f CM |
1500 | if (skip_level < i && i >= lowest_unlock) |
1501 | no_skips = 1; | |
1502 | ||
925baedd CM |
1503 | t = path->nodes[i]; |
1504 | if (i >= lowest_unlock && i > skip_level && path->locks[i]) { | |
1505 | btrfs_tree_unlock(t); | |
1506 | path->locks[i] = 0; | |
1507 | } | |
1508 | } | |
1509 | } | |
1510 | ||
b4ce94de CM |
1511 | /* |
1512 | * This releases any locks held in the path starting at level and | |
1513 | * going all the way up to the root. | |
1514 | * | |
1515 | * btrfs_search_slot will keep the lock held on higher nodes in a few | |
1516 | * corner cases, such as COW of the block at slot zero in the node. This | |
1517 | * ignores those rules, and it should only be called when there are no | |
1518 | * more updates to be done higher up in the tree. | |
1519 | */ | |
1520 | noinline void btrfs_unlock_up_safe(struct btrfs_path *path, int level) | |
1521 | { | |
1522 | int i; | |
1523 | ||
5d4f98a2 | 1524 | if (path->keep_locks) |
b4ce94de CM |
1525 | return; |
1526 | ||
1527 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { | |
1528 | if (!path->nodes[i]) | |
12f4dacc | 1529 | continue; |
b4ce94de | 1530 | if (!path->locks[i]) |
12f4dacc | 1531 | continue; |
b4ce94de CM |
1532 | btrfs_tree_unlock(path->nodes[i]); |
1533 | path->locks[i] = 0; | |
1534 | } | |
1535 | } | |
1536 | ||
c8c42864 CM |
1537 | /* |
1538 | * helper function for btrfs_search_slot. The goal is to find a block | |
1539 | * in cache without setting the path to blocking. If we find the block | |
1540 | * we return zero and the path is unchanged. | |
1541 | * | |
1542 | * If we can't find the block, we set the path blocking and do some | |
1543 | * reada. -EAGAIN is returned and the search must be repeated. | |
1544 | */ | |
1545 | static int | |
1546 | read_block_for_search(struct btrfs_trans_handle *trans, | |
1547 | struct btrfs_root *root, struct btrfs_path *p, | |
1548 | struct extent_buffer **eb_ret, int level, int slot, | |
1549 | struct btrfs_key *key) | |
1550 | { | |
1551 | u64 blocknr; | |
1552 | u64 gen; | |
1553 | u32 blocksize; | |
1554 | struct extent_buffer *b = *eb_ret; | |
1555 | struct extent_buffer *tmp; | |
76a05b35 | 1556 | int ret; |
c8c42864 CM |
1557 | |
1558 | blocknr = btrfs_node_blockptr(b, slot); | |
1559 | gen = btrfs_node_ptr_generation(b, slot); | |
1560 | blocksize = btrfs_level_size(root, level - 1); | |
1561 | ||
1562 | tmp = btrfs_find_tree_block(root, blocknr, blocksize); | |
1563 | if (tmp && btrfs_buffer_uptodate(tmp, gen)) { | |
76a05b35 CM |
1564 | /* |
1565 | * we found an up to date block without sleeping, return | |
1566 | * right away | |
1567 | */ | |
c8c42864 CM |
1568 | *eb_ret = tmp; |
1569 | return 0; | |
1570 | } | |
1571 | ||
1572 | /* | |
1573 | * reduce lock contention at high levels | |
1574 | * of the btree by dropping locks before | |
76a05b35 CM |
1575 | * we read. Don't release the lock on the current |
1576 | * level because we need to walk this node to figure | |
1577 | * out which blocks to read. | |
c8c42864 | 1578 | */ |
8c594ea8 CM |
1579 | btrfs_unlock_up_safe(p, level + 1); |
1580 | btrfs_set_path_blocking(p); | |
1581 | ||
c8c42864 CM |
1582 | if (tmp) |
1583 | free_extent_buffer(tmp); | |
1584 | if (p->reada) | |
1585 | reada_for_search(root, p, level, slot, key->objectid); | |
1586 | ||
8c594ea8 | 1587 | btrfs_release_path(NULL, p); |
76a05b35 CM |
1588 | |
1589 | ret = -EAGAIN; | |
c8c42864 | 1590 | tmp = read_tree_block(root, blocknr, blocksize, gen); |
76a05b35 CM |
1591 | if (tmp) { |
1592 | /* | |
1593 | * If the read above didn't mark this buffer up to date, | |
1594 | * it will never end up being up to date. Set ret to EIO now | |
1595 | * and give up so that our caller doesn't loop forever | |
1596 | * on our EAGAINs. | |
1597 | */ | |
1598 | if (!btrfs_buffer_uptodate(tmp, 0)) | |
1599 | ret = -EIO; | |
c8c42864 | 1600 | free_extent_buffer(tmp); |
76a05b35 CM |
1601 | } |
1602 | return ret; | |
c8c42864 CM |
1603 | } |
1604 | ||
1605 | /* | |
1606 | * helper function for btrfs_search_slot. This does all of the checks | |
1607 | * for node-level blocks and does any balancing required based on | |
1608 | * the ins_len. | |
1609 | * | |
1610 | * If no extra work was required, zero is returned. If we had to | |
1611 | * drop the path, -EAGAIN is returned and btrfs_search_slot must | |
1612 | * start over | |
1613 | */ | |
1614 | static int | |
1615 | setup_nodes_for_search(struct btrfs_trans_handle *trans, | |
1616 | struct btrfs_root *root, struct btrfs_path *p, | |
1617 | struct extent_buffer *b, int level, int ins_len) | |
1618 | { | |
1619 | int ret; | |
1620 | if ((p->search_for_split || ins_len > 0) && btrfs_header_nritems(b) >= | |
1621 | BTRFS_NODEPTRS_PER_BLOCK(root) - 3) { | |
1622 | int sret; | |
1623 | ||
1624 | sret = reada_for_balance(root, p, level); | |
1625 | if (sret) | |
1626 | goto again; | |
1627 | ||
1628 | btrfs_set_path_blocking(p); | |
1629 | sret = split_node(trans, root, p, level); | |
1630 | btrfs_clear_path_blocking(p, NULL); | |
1631 | ||
1632 | BUG_ON(sret > 0); | |
1633 | if (sret) { | |
1634 | ret = sret; | |
1635 | goto done; | |
1636 | } | |
1637 | b = p->nodes[level]; | |
1638 | } else if (ins_len < 0 && btrfs_header_nritems(b) < | |
cfbb9308 | 1639 | BTRFS_NODEPTRS_PER_BLOCK(root) / 2) { |
c8c42864 CM |
1640 | int sret; |
1641 | ||
1642 | sret = reada_for_balance(root, p, level); | |
1643 | if (sret) | |
1644 | goto again; | |
1645 | ||
1646 | btrfs_set_path_blocking(p); | |
1647 | sret = balance_level(trans, root, p, level); | |
1648 | btrfs_clear_path_blocking(p, NULL); | |
1649 | ||
1650 | if (sret) { | |
1651 | ret = sret; | |
1652 | goto done; | |
1653 | } | |
1654 | b = p->nodes[level]; | |
1655 | if (!b) { | |
1656 | btrfs_release_path(NULL, p); | |
1657 | goto again; | |
1658 | } | |
1659 | BUG_ON(btrfs_header_nritems(b) == 1); | |
1660 | } | |
1661 | return 0; | |
1662 | ||
1663 | again: | |
1664 | ret = -EAGAIN; | |
1665 | done: | |
1666 | return ret; | |
1667 | } | |
1668 | ||
74123bd7 CM |
1669 | /* |
1670 | * look for key in the tree. path is filled in with nodes along the way | |
1671 | * if key is found, we return zero and you can find the item in the leaf | |
1672 | * level of the path (level 0) | |
1673 | * | |
1674 | * If the key isn't found, the path points to the slot where it should | |
aa5d6bed CM |
1675 | * be inserted, and 1 is returned. If there are other errors during the |
1676 | * search a negative error number is returned. | |
97571fd0 CM |
1677 | * |
1678 | * if ins_len > 0, nodes and leaves will be split as we walk down the | |
1679 | * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if | |
1680 | * possible) | |
74123bd7 | 1681 | */ |
e089f05c CM |
1682 | int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root |
1683 | *root, struct btrfs_key *key, struct btrfs_path *p, int | |
1684 | ins_len, int cow) | |
be0e5c09 | 1685 | { |
5f39d397 | 1686 | struct extent_buffer *b; |
be0e5c09 CM |
1687 | int slot; |
1688 | int ret; | |
33c66f43 | 1689 | int err; |
be0e5c09 | 1690 | int level; |
925baedd | 1691 | int lowest_unlock = 1; |
9f3a7427 CM |
1692 | u8 lowest_level = 0; |
1693 | ||
6702ed49 | 1694 | lowest_level = p->lowest_level; |
323ac95b | 1695 | WARN_ON(lowest_level && ins_len > 0); |
22b0ebda | 1696 | WARN_ON(p->nodes[0] != NULL); |
25179201 | 1697 | |
925baedd CM |
1698 | if (ins_len < 0) |
1699 | lowest_unlock = 2; | |
65b51a00 | 1700 | |
bb803951 | 1701 | again: |
5d4f98a2 YZ |
1702 | if (p->search_commit_root) { |
1703 | b = root->commit_root; | |
1704 | extent_buffer_get(b); | |
1705 | if (!p->skip_locking) | |
1706 | btrfs_tree_lock(b); | |
1707 | } else { | |
1708 | if (p->skip_locking) | |
1709 | b = btrfs_root_node(root); | |
1710 | else | |
1711 | b = btrfs_lock_root_node(root); | |
1712 | } | |
925baedd | 1713 | |
eb60ceac | 1714 | while (b) { |
5f39d397 | 1715 | level = btrfs_header_level(b); |
65b51a00 CM |
1716 | |
1717 | /* | |
1718 | * setup the path here so we can release it under lock | |
1719 | * contention with the cow code | |
1720 | */ | |
1721 | p->nodes[level] = b; | |
1722 | if (!p->skip_locking) | |
1723 | p->locks[level] = 1; | |
1724 | ||
02217ed2 | 1725 | if (cow) { |
c8c42864 CM |
1726 | /* |
1727 | * if we don't really need to cow this block | |
1728 | * then we don't want to set the path blocking, | |
1729 | * so we test it here | |
1730 | */ | |
5d4f98a2 | 1731 | if (!should_cow_block(trans, root, b)) |
65b51a00 | 1732 | goto cow_done; |
5d4f98a2 | 1733 | |
b4ce94de CM |
1734 | btrfs_set_path_blocking(p); |
1735 | ||
33c66f43 YZ |
1736 | err = btrfs_cow_block(trans, root, b, |
1737 | p->nodes[level + 1], | |
1738 | p->slots[level + 1], &b); | |
1739 | if (err) { | |
5f39d397 | 1740 | free_extent_buffer(b); |
33c66f43 | 1741 | ret = err; |
65b51a00 | 1742 | goto done; |
54aa1f4d | 1743 | } |
02217ed2 | 1744 | } |
65b51a00 | 1745 | cow_done: |
02217ed2 | 1746 | BUG_ON(!cow && ins_len); |
5f39d397 | 1747 | if (level != btrfs_header_level(b)) |
2c90e5d6 | 1748 | WARN_ON(1); |
5f39d397 | 1749 | level = btrfs_header_level(b); |
65b51a00 | 1750 | |
eb60ceac | 1751 | p->nodes[level] = b; |
5cd57b2c CM |
1752 | if (!p->skip_locking) |
1753 | p->locks[level] = 1; | |
65b51a00 | 1754 | |
4008c04a | 1755 | btrfs_clear_path_blocking(p, NULL); |
b4ce94de CM |
1756 | |
1757 | /* | |
1758 | * we have a lock on b and as long as we aren't changing | |
1759 | * the tree, there is no way to for the items in b to change. | |
1760 | * It is safe to drop the lock on our parent before we | |
1761 | * go through the expensive btree search on b. | |
1762 | * | |
1763 | * If cow is true, then we might be changing slot zero, | |
1764 | * which may require changing the parent. So, we can't | |
1765 | * drop the lock until after we know which slot we're | |
1766 | * operating on. | |
1767 | */ | |
1768 | if (!cow) | |
1769 | btrfs_unlock_up_safe(p, level + 1); | |
1770 | ||
123abc88 | 1771 | ret = check_block(root, p, level); |
65b51a00 CM |
1772 | if (ret) { |
1773 | ret = -1; | |
1774 | goto done; | |
1775 | } | |
925baedd | 1776 | |
5f39d397 | 1777 | ret = bin_search(b, key, level, &slot); |
b4ce94de | 1778 | |
5f39d397 | 1779 | if (level != 0) { |
33c66f43 YZ |
1780 | int dec = 0; |
1781 | if (ret && slot > 0) { | |
1782 | dec = 1; | |
be0e5c09 | 1783 | slot -= 1; |
33c66f43 | 1784 | } |
be0e5c09 | 1785 | p->slots[level] = slot; |
33c66f43 | 1786 | err = setup_nodes_for_search(trans, root, p, b, level, |
c8c42864 | 1787 | ins_len); |
33c66f43 | 1788 | if (err == -EAGAIN) |
c8c42864 | 1789 | goto again; |
33c66f43 YZ |
1790 | if (err) { |
1791 | ret = err; | |
c8c42864 | 1792 | goto done; |
33c66f43 | 1793 | } |
c8c42864 CM |
1794 | b = p->nodes[level]; |
1795 | slot = p->slots[level]; | |
b4ce94de | 1796 | |
f9efa9c7 CM |
1797 | unlock_up(p, level, lowest_unlock); |
1798 | ||
925baedd | 1799 | if (level == lowest_level) { |
33c66f43 YZ |
1800 | if (dec) |
1801 | p->slots[level]++; | |
5b21f2ed | 1802 | goto done; |
925baedd | 1803 | } |
ca7a79ad | 1804 | |
33c66f43 | 1805 | err = read_block_for_search(trans, root, p, |
c8c42864 | 1806 | &b, level, slot, key); |
33c66f43 | 1807 | if (err == -EAGAIN) |
c8c42864 | 1808 | goto again; |
33c66f43 YZ |
1809 | if (err) { |
1810 | ret = err; | |
76a05b35 | 1811 | goto done; |
33c66f43 | 1812 | } |
76a05b35 | 1813 | |
b4ce94de | 1814 | if (!p->skip_locking) { |
4008c04a | 1815 | btrfs_clear_path_blocking(p, NULL); |
33c66f43 | 1816 | err = btrfs_try_spin_lock(b); |
b4ce94de | 1817 | |
33c66f43 | 1818 | if (!err) { |
b4ce94de CM |
1819 | btrfs_set_path_blocking(p); |
1820 | btrfs_tree_lock(b); | |
4008c04a | 1821 | btrfs_clear_path_blocking(p, b); |
b4ce94de CM |
1822 | } |
1823 | } | |
be0e5c09 CM |
1824 | } else { |
1825 | p->slots[level] = slot; | |
87b29b20 YZ |
1826 | if (ins_len > 0 && |
1827 | btrfs_leaf_free_space(root, b) < ins_len) { | |
b4ce94de | 1828 | btrfs_set_path_blocking(p); |
33c66f43 YZ |
1829 | err = split_leaf(trans, root, key, |
1830 | p, ins_len, ret == 0); | |
4008c04a | 1831 | btrfs_clear_path_blocking(p, NULL); |
b4ce94de | 1832 | |
33c66f43 YZ |
1833 | BUG_ON(err > 0); |
1834 | if (err) { | |
1835 | ret = err; | |
65b51a00 CM |
1836 | goto done; |
1837 | } | |
5c680ed6 | 1838 | } |
459931ec CM |
1839 | if (!p->search_for_split) |
1840 | unlock_up(p, level, lowest_unlock); | |
65b51a00 | 1841 | goto done; |
be0e5c09 CM |
1842 | } |
1843 | } | |
65b51a00 CM |
1844 | ret = 1; |
1845 | done: | |
b4ce94de CM |
1846 | /* |
1847 | * we don't really know what they plan on doing with the path | |
1848 | * from here on, so for now just mark it as blocking | |
1849 | */ | |
b9473439 CM |
1850 | if (!p->leave_spinning) |
1851 | btrfs_set_path_blocking(p); | |
76a05b35 CM |
1852 | if (ret < 0) |
1853 | btrfs_release_path(root, p); | |
65b51a00 | 1854 | return ret; |
be0e5c09 CM |
1855 | } |
1856 | ||
74123bd7 CM |
1857 | /* |
1858 | * adjust the pointers going up the tree, starting at level | |
1859 | * making sure the right key of each node is points to 'key'. | |
1860 | * This is used after shifting pointers to the left, so it stops | |
1861 | * fixing up pointers when a given leaf/node is not in slot 0 of the | |
1862 | * higher levels | |
aa5d6bed CM |
1863 | * |
1864 | * If this fails to write a tree block, it returns -1, but continues | |
1865 | * fixing up the blocks in ram so the tree is consistent. | |
74123bd7 | 1866 | */ |
5f39d397 CM |
1867 | static int fixup_low_keys(struct btrfs_trans_handle *trans, |
1868 | struct btrfs_root *root, struct btrfs_path *path, | |
1869 | struct btrfs_disk_key *key, int level) | |
be0e5c09 CM |
1870 | { |
1871 | int i; | |
aa5d6bed | 1872 | int ret = 0; |
5f39d397 CM |
1873 | struct extent_buffer *t; |
1874 | ||
234b63a0 | 1875 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { |
be0e5c09 | 1876 | int tslot = path->slots[i]; |
eb60ceac | 1877 | if (!path->nodes[i]) |
be0e5c09 | 1878 | break; |
5f39d397 CM |
1879 | t = path->nodes[i]; |
1880 | btrfs_set_node_key(t, key, tslot); | |
d6025579 | 1881 | btrfs_mark_buffer_dirty(path->nodes[i]); |
be0e5c09 CM |
1882 | if (tslot != 0) |
1883 | break; | |
1884 | } | |
aa5d6bed | 1885 | return ret; |
be0e5c09 CM |
1886 | } |
1887 | ||
31840ae1 ZY |
1888 | /* |
1889 | * update item key. | |
1890 | * | |
1891 | * This function isn't completely safe. It's the caller's responsibility | |
1892 | * that the new key won't break the order | |
1893 | */ | |
1894 | int btrfs_set_item_key_safe(struct btrfs_trans_handle *trans, | |
1895 | struct btrfs_root *root, struct btrfs_path *path, | |
1896 | struct btrfs_key *new_key) | |
1897 | { | |
1898 | struct btrfs_disk_key disk_key; | |
1899 | struct extent_buffer *eb; | |
1900 | int slot; | |
1901 | ||
1902 | eb = path->nodes[0]; | |
1903 | slot = path->slots[0]; | |
1904 | if (slot > 0) { | |
1905 | btrfs_item_key(eb, &disk_key, slot - 1); | |
1906 | if (comp_keys(&disk_key, new_key) >= 0) | |
1907 | return -1; | |
1908 | } | |
1909 | if (slot < btrfs_header_nritems(eb) - 1) { | |
1910 | btrfs_item_key(eb, &disk_key, slot + 1); | |
1911 | if (comp_keys(&disk_key, new_key) <= 0) | |
1912 | return -1; | |
1913 | } | |
1914 | ||
1915 | btrfs_cpu_key_to_disk(&disk_key, new_key); | |
1916 | btrfs_set_item_key(eb, &disk_key, slot); | |
1917 | btrfs_mark_buffer_dirty(eb); | |
1918 | if (slot == 0) | |
1919 | fixup_low_keys(trans, root, path, &disk_key, 1); | |
1920 | return 0; | |
1921 | } | |
1922 | ||
74123bd7 CM |
1923 | /* |
1924 | * try to push data from one node into the next node left in the | |
79f95c82 | 1925 | * tree. |
aa5d6bed CM |
1926 | * |
1927 | * returns 0 if some ptrs were pushed left, < 0 if there was some horrible | |
1928 | * error, and > 0 if there was no room in the left hand block. | |
74123bd7 | 1929 | */ |
98ed5174 CM |
1930 | static int push_node_left(struct btrfs_trans_handle *trans, |
1931 | struct btrfs_root *root, struct extent_buffer *dst, | |
971a1f66 | 1932 | struct extent_buffer *src, int empty) |
be0e5c09 | 1933 | { |
be0e5c09 | 1934 | int push_items = 0; |
bb803951 CM |
1935 | int src_nritems; |
1936 | int dst_nritems; | |
aa5d6bed | 1937 | int ret = 0; |
be0e5c09 | 1938 | |
5f39d397 CM |
1939 | src_nritems = btrfs_header_nritems(src); |
1940 | dst_nritems = btrfs_header_nritems(dst); | |
123abc88 | 1941 | push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems; |
7bb86316 CM |
1942 | WARN_ON(btrfs_header_generation(src) != trans->transid); |
1943 | WARN_ON(btrfs_header_generation(dst) != trans->transid); | |
54aa1f4d | 1944 | |
bce4eae9 | 1945 | if (!empty && src_nritems <= 8) |
971a1f66 CM |
1946 | return 1; |
1947 | ||
d397712b | 1948 | if (push_items <= 0) |
be0e5c09 CM |
1949 | return 1; |
1950 | ||
bce4eae9 | 1951 | if (empty) { |
971a1f66 | 1952 | push_items = min(src_nritems, push_items); |
bce4eae9 CM |
1953 | if (push_items < src_nritems) { |
1954 | /* leave at least 8 pointers in the node if | |
1955 | * we aren't going to empty it | |
1956 | */ | |
1957 | if (src_nritems - push_items < 8) { | |
1958 | if (push_items <= 8) | |
1959 | return 1; | |
1960 | push_items -= 8; | |
1961 | } | |
1962 | } | |
1963 | } else | |
1964 | push_items = min(src_nritems - 8, push_items); | |
79f95c82 | 1965 | |
5f39d397 CM |
1966 | copy_extent_buffer(dst, src, |
1967 | btrfs_node_key_ptr_offset(dst_nritems), | |
1968 | btrfs_node_key_ptr_offset(0), | |
d397712b | 1969 | push_items * sizeof(struct btrfs_key_ptr)); |
5f39d397 | 1970 | |
bb803951 | 1971 | if (push_items < src_nritems) { |
5f39d397 CM |
1972 | memmove_extent_buffer(src, btrfs_node_key_ptr_offset(0), |
1973 | btrfs_node_key_ptr_offset(push_items), | |
1974 | (src_nritems - push_items) * | |
1975 | sizeof(struct btrfs_key_ptr)); | |
1976 | } | |
1977 | btrfs_set_header_nritems(src, src_nritems - push_items); | |
1978 | btrfs_set_header_nritems(dst, dst_nritems + push_items); | |
1979 | btrfs_mark_buffer_dirty(src); | |
1980 | btrfs_mark_buffer_dirty(dst); | |
31840ae1 | 1981 | |
79f95c82 CM |
1982 | return ret; |
1983 | } | |
1984 | ||
1985 | /* | |
1986 | * try to push data from one node into the next node right in the | |
1987 | * tree. | |
1988 | * | |
1989 | * returns 0 if some ptrs were pushed, < 0 if there was some horrible | |
1990 | * error, and > 0 if there was no room in the right hand block. | |
1991 | * | |
1992 | * this will only push up to 1/2 the contents of the left node over | |
1993 | */ | |
5f39d397 CM |
1994 | static int balance_node_right(struct btrfs_trans_handle *trans, |
1995 | struct btrfs_root *root, | |
1996 | struct extent_buffer *dst, | |
1997 | struct extent_buffer *src) | |
79f95c82 | 1998 | { |
79f95c82 CM |
1999 | int push_items = 0; |
2000 | int max_push; | |
2001 | int src_nritems; | |
2002 | int dst_nritems; | |
2003 | int ret = 0; | |
79f95c82 | 2004 | |
7bb86316 CM |
2005 | WARN_ON(btrfs_header_generation(src) != trans->transid); |
2006 | WARN_ON(btrfs_header_generation(dst) != trans->transid); | |
2007 | ||
5f39d397 CM |
2008 | src_nritems = btrfs_header_nritems(src); |
2009 | dst_nritems = btrfs_header_nritems(dst); | |
123abc88 | 2010 | push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems; |
d397712b | 2011 | if (push_items <= 0) |
79f95c82 | 2012 | return 1; |
bce4eae9 | 2013 | |
d397712b | 2014 | if (src_nritems < 4) |
bce4eae9 | 2015 | return 1; |
79f95c82 CM |
2016 | |
2017 | max_push = src_nritems / 2 + 1; | |
2018 | /* don't try to empty the node */ | |
d397712b | 2019 | if (max_push >= src_nritems) |
79f95c82 | 2020 | return 1; |
252c38f0 | 2021 | |
79f95c82 CM |
2022 | if (max_push < push_items) |
2023 | push_items = max_push; | |
2024 | ||
5f39d397 CM |
2025 | memmove_extent_buffer(dst, btrfs_node_key_ptr_offset(push_items), |
2026 | btrfs_node_key_ptr_offset(0), | |
2027 | (dst_nritems) * | |
2028 | sizeof(struct btrfs_key_ptr)); | |
d6025579 | 2029 | |
5f39d397 CM |
2030 | copy_extent_buffer(dst, src, |
2031 | btrfs_node_key_ptr_offset(0), | |
2032 | btrfs_node_key_ptr_offset(src_nritems - push_items), | |
d397712b | 2033 | push_items * sizeof(struct btrfs_key_ptr)); |
79f95c82 | 2034 | |
5f39d397 CM |
2035 | btrfs_set_header_nritems(src, src_nritems - push_items); |
2036 | btrfs_set_header_nritems(dst, dst_nritems + push_items); | |
79f95c82 | 2037 | |
5f39d397 CM |
2038 | btrfs_mark_buffer_dirty(src); |
2039 | btrfs_mark_buffer_dirty(dst); | |
31840ae1 | 2040 | |
aa5d6bed | 2041 | return ret; |
be0e5c09 CM |
2042 | } |
2043 | ||
97571fd0 CM |
2044 | /* |
2045 | * helper function to insert a new root level in the tree. | |
2046 | * A new node is allocated, and a single item is inserted to | |
2047 | * point to the existing root | |
aa5d6bed CM |
2048 | * |
2049 | * returns zero on success or < 0 on failure. | |
97571fd0 | 2050 | */ |
d397712b | 2051 | static noinline int insert_new_root(struct btrfs_trans_handle *trans, |
5f39d397 CM |
2052 | struct btrfs_root *root, |
2053 | struct btrfs_path *path, int level) | |
5c680ed6 | 2054 | { |
7bb86316 | 2055 | u64 lower_gen; |
5f39d397 CM |
2056 | struct extent_buffer *lower; |
2057 | struct extent_buffer *c; | |
925baedd | 2058 | struct extent_buffer *old; |
5f39d397 | 2059 | struct btrfs_disk_key lower_key; |
5c680ed6 CM |
2060 | |
2061 | BUG_ON(path->nodes[level]); | |
2062 | BUG_ON(path->nodes[level-1] != root->node); | |
2063 | ||
7bb86316 CM |
2064 | lower = path->nodes[level-1]; |
2065 | if (level == 1) | |
2066 | btrfs_item_key(lower, &lower_key, 0); | |
2067 | else | |
2068 | btrfs_node_key(lower, &lower_key, 0); | |
2069 | ||
31840ae1 | 2070 | c = btrfs_alloc_free_block(trans, root, root->nodesize, 0, |
5d4f98a2 | 2071 | root->root_key.objectid, &lower_key, |
ad3d81ba | 2072 | level, root->node->start, 0); |
5f39d397 CM |
2073 | if (IS_ERR(c)) |
2074 | return PTR_ERR(c); | |
925baedd | 2075 | |
5d4f98a2 | 2076 | memset_extent_buffer(c, 0, 0, sizeof(struct btrfs_header)); |
5f39d397 CM |
2077 | btrfs_set_header_nritems(c, 1); |
2078 | btrfs_set_header_level(c, level); | |
db94535d | 2079 | btrfs_set_header_bytenr(c, c->start); |
5f39d397 | 2080 | btrfs_set_header_generation(c, trans->transid); |
5d4f98a2 | 2081 | btrfs_set_header_backref_rev(c, BTRFS_MIXED_BACKREF_REV); |
5f39d397 | 2082 | btrfs_set_header_owner(c, root->root_key.objectid); |
5f39d397 CM |
2083 | |
2084 | write_extent_buffer(c, root->fs_info->fsid, | |
2085 | (unsigned long)btrfs_header_fsid(c), | |
2086 | BTRFS_FSID_SIZE); | |
e17cade2 CM |
2087 | |
2088 | write_extent_buffer(c, root->fs_info->chunk_tree_uuid, | |
2089 | (unsigned long)btrfs_header_chunk_tree_uuid(c), | |
2090 | BTRFS_UUID_SIZE); | |
2091 | ||
5f39d397 | 2092 | btrfs_set_node_key(c, &lower_key, 0); |
db94535d | 2093 | btrfs_set_node_blockptr(c, 0, lower->start); |
7bb86316 | 2094 | lower_gen = btrfs_header_generation(lower); |
31840ae1 | 2095 | WARN_ON(lower_gen != trans->transid); |
7bb86316 CM |
2096 | |
2097 | btrfs_set_node_ptr_generation(c, 0, lower_gen); | |
d5719762 | 2098 | |
5f39d397 | 2099 | btrfs_mark_buffer_dirty(c); |
d5719762 | 2100 | |
925baedd CM |
2101 | spin_lock(&root->node_lock); |
2102 | old = root->node; | |
5f39d397 | 2103 | root->node = c; |
925baedd CM |
2104 | spin_unlock(&root->node_lock); |
2105 | ||
2106 | /* the super has an extra ref to root->node */ | |
2107 | free_extent_buffer(old); | |
2108 | ||
0b86a832 | 2109 | add_root_to_dirty_list(root); |
5f39d397 CM |
2110 | extent_buffer_get(c); |
2111 | path->nodes[level] = c; | |
925baedd | 2112 | path->locks[level] = 1; |
5c680ed6 CM |
2113 | path->slots[level] = 0; |
2114 | return 0; | |
2115 | } | |
2116 | ||
74123bd7 CM |
2117 | /* |
2118 | * worker function to insert a single pointer in a node. | |
2119 | * the node should have enough room for the pointer already | |
97571fd0 | 2120 | * |
74123bd7 CM |
2121 | * slot and level indicate where you want the key to go, and |
2122 | * blocknr is the block the key points to. | |
aa5d6bed CM |
2123 | * |
2124 | * returns zero on success and < 0 on any error | |
74123bd7 | 2125 | */ |
e089f05c CM |
2126 | static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root |
2127 | *root, struct btrfs_path *path, struct btrfs_disk_key | |
db94535d | 2128 | *key, u64 bytenr, int slot, int level) |
74123bd7 | 2129 | { |
5f39d397 | 2130 | struct extent_buffer *lower; |
74123bd7 | 2131 | int nritems; |
5c680ed6 CM |
2132 | |
2133 | BUG_ON(!path->nodes[level]); | |
5f39d397 CM |
2134 | lower = path->nodes[level]; |
2135 | nritems = btrfs_header_nritems(lower); | |
c293498b | 2136 | BUG_ON(slot > nritems); |
123abc88 | 2137 | if (nritems == BTRFS_NODEPTRS_PER_BLOCK(root)) |
74123bd7 CM |
2138 | BUG(); |
2139 | if (slot != nritems) { | |
5f39d397 CM |
2140 | memmove_extent_buffer(lower, |
2141 | btrfs_node_key_ptr_offset(slot + 1), | |
2142 | btrfs_node_key_ptr_offset(slot), | |
d6025579 | 2143 | (nritems - slot) * sizeof(struct btrfs_key_ptr)); |
74123bd7 | 2144 | } |
5f39d397 | 2145 | btrfs_set_node_key(lower, key, slot); |
db94535d | 2146 | btrfs_set_node_blockptr(lower, slot, bytenr); |
74493f7a CM |
2147 | WARN_ON(trans->transid == 0); |
2148 | btrfs_set_node_ptr_generation(lower, slot, trans->transid); | |
5f39d397 CM |
2149 | btrfs_set_header_nritems(lower, nritems + 1); |
2150 | btrfs_mark_buffer_dirty(lower); | |
74123bd7 CM |
2151 | return 0; |
2152 | } | |
2153 | ||
97571fd0 CM |
2154 | /* |
2155 | * split the node at the specified level in path in two. | |
2156 | * The path is corrected to point to the appropriate node after the split | |
2157 | * | |
2158 | * Before splitting this tries to make some room in the node by pushing | |
2159 | * left and right, if either one works, it returns right away. | |
aa5d6bed CM |
2160 | * |
2161 | * returns 0 on success and < 0 on failure | |
97571fd0 | 2162 | */ |
e02119d5 CM |
2163 | static noinline int split_node(struct btrfs_trans_handle *trans, |
2164 | struct btrfs_root *root, | |
2165 | struct btrfs_path *path, int level) | |
be0e5c09 | 2166 | { |
5f39d397 CM |
2167 | struct extent_buffer *c; |
2168 | struct extent_buffer *split; | |
2169 | struct btrfs_disk_key disk_key; | |
be0e5c09 | 2170 | int mid; |
5c680ed6 | 2171 | int ret; |
aa5d6bed | 2172 | int wret; |
7518a238 | 2173 | u32 c_nritems; |
eb60ceac | 2174 | |
5f39d397 | 2175 | c = path->nodes[level]; |
7bb86316 | 2176 | WARN_ON(btrfs_header_generation(c) != trans->transid); |
5f39d397 | 2177 | if (c == root->node) { |
5c680ed6 | 2178 | /* trying to split the root, lets make a new one */ |
e089f05c | 2179 | ret = insert_new_root(trans, root, path, level + 1); |
5c680ed6 CM |
2180 | if (ret) |
2181 | return ret; | |
b3612421 | 2182 | } else { |
e66f709b | 2183 | ret = push_nodes_for_insert(trans, root, path, level); |
5f39d397 CM |
2184 | c = path->nodes[level]; |
2185 | if (!ret && btrfs_header_nritems(c) < | |
c448acf0 | 2186 | BTRFS_NODEPTRS_PER_BLOCK(root) - 3) |
e66f709b | 2187 | return 0; |
54aa1f4d CM |
2188 | if (ret < 0) |
2189 | return ret; | |
be0e5c09 | 2190 | } |
e66f709b | 2191 | |
5f39d397 | 2192 | c_nritems = btrfs_header_nritems(c); |
5d4f98a2 YZ |
2193 | mid = (c_nritems + 1) / 2; |
2194 | btrfs_node_key(c, &disk_key, mid); | |
7bb86316 | 2195 | |
5d4f98a2 | 2196 | split = btrfs_alloc_free_block(trans, root, root->nodesize, 0, |
31840ae1 | 2197 | root->root_key.objectid, |
5d4f98a2 | 2198 | &disk_key, level, c->start, 0); |
5f39d397 CM |
2199 | if (IS_ERR(split)) |
2200 | return PTR_ERR(split); | |
2201 | ||
5d4f98a2 | 2202 | memset_extent_buffer(split, 0, 0, sizeof(struct btrfs_header)); |
5f39d397 | 2203 | btrfs_set_header_level(split, btrfs_header_level(c)); |
db94535d | 2204 | btrfs_set_header_bytenr(split, split->start); |
5f39d397 | 2205 | btrfs_set_header_generation(split, trans->transid); |
5d4f98a2 | 2206 | btrfs_set_header_backref_rev(split, BTRFS_MIXED_BACKREF_REV); |
5f39d397 CM |
2207 | btrfs_set_header_owner(split, root->root_key.objectid); |
2208 | write_extent_buffer(split, root->fs_info->fsid, | |
2209 | (unsigned long)btrfs_header_fsid(split), | |
2210 | BTRFS_FSID_SIZE); | |
e17cade2 CM |
2211 | write_extent_buffer(split, root->fs_info->chunk_tree_uuid, |
2212 | (unsigned long)btrfs_header_chunk_tree_uuid(split), | |
2213 | BTRFS_UUID_SIZE); | |
54aa1f4d | 2214 | |
5f39d397 CM |
2215 | |
2216 | copy_extent_buffer(split, c, | |
2217 | btrfs_node_key_ptr_offset(0), | |
2218 | btrfs_node_key_ptr_offset(mid), | |
2219 | (c_nritems - mid) * sizeof(struct btrfs_key_ptr)); | |
2220 | btrfs_set_header_nritems(split, c_nritems - mid); | |
2221 | btrfs_set_header_nritems(c, mid); | |
aa5d6bed CM |
2222 | ret = 0; |
2223 | ||
5f39d397 CM |
2224 | btrfs_mark_buffer_dirty(c); |
2225 | btrfs_mark_buffer_dirty(split); | |
2226 | ||
db94535d | 2227 | wret = insert_ptr(trans, root, path, &disk_key, split->start, |
5f39d397 | 2228 | path->slots[level + 1] + 1, |
123abc88 | 2229 | level + 1); |
aa5d6bed CM |
2230 | if (wret) |
2231 | ret = wret; | |
2232 | ||
5de08d7d | 2233 | if (path->slots[level] >= mid) { |
5c680ed6 | 2234 | path->slots[level] -= mid; |
925baedd | 2235 | btrfs_tree_unlock(c); |
5f39d397 CM |
2236 | free_extent_buffer(c); |
2237 | path->nodes[level] = split; | |
5c680ed6 CM |
2238 | path->slots[level + 1] += 1; |
2239 | } else { | |
925baedd | 2240 | btrfs_tree_unlock(split); |
5f39d397 | 2241 | free_extent_buffer(split); |
be0e5c09 | 2242 | } |
aa5d6bed | 2243 | return ret; |
be0e5c09 CM |
2244 | } |
2245 | ||
74123bd7 CM |
2246 | /* |
2247 | * how many bytes are required to store the items in a leaf. start | |
2248 | * and nr indicate which items in the leaf to check. This totals up the | |
2249 | * space used both by the item structs and the item data | |
2250 | */ | |
5f39d397 | 2251 | static int leaf_space_used(struct extent_buffer *l, int start, int nr) |
be0e5c09 CM |
2252 | { |
2253 | int data_len; | |
5f39d397 | 2254 | int nritems = btrfs_header_nritems(l); |
d4dbff95 | 2255 | int end = min(nritems, start + nr) - 1; |
be0e5c09 CM |
2256 | |
2257 | if (!nr) | |
2258 | return 0; | |
5f39d397 CM |
2259 | data_len = btrfs_item_end_nr(l, start); |
2260 | data_len = data_len - btrfs_item_offset_nr(l, end); | |
0783fcfc | 2261 | data_len += sizeof(struct btrfs_item) * nr; |
d4dbff95 | 2262 | WARN_ON(data_len < 0); |
be0e5c09 CM |
2263 | return data_len; |
2264 | } | |
2265 | ||
d4dbff95 CM |
2266 | /* |
2267 | * The space between the end of the leaf items and | |
2268 | * the start of the leaf data. IOW, how much room | |
2269 | * the leaf has left for both items and data | |
2270 | */ | |
d397712b | 2271 | noinline int btrfs_leaf_free_space(struct btrfs_root *root, |
e02119d5 | 2272 | struct extent_buffer *leaf) |
d4dbff95 | 2273 | { |
5f39d397 CM |
2274 | int nritems = btrfs_header_nritems(leaf); |
2275 | int ret; | |
2276 | ret = BTRFS_LEAF_DATA_SIZE(root) - leaf_space_used(leaf, 0, nritems); | |
2277 | if (ret < 0) { | |
d397712b CM |
2278 | printk(KERN_CRIT "leaf free space ret %d, leaf data size %lu, " |
2279 | "used %d nritems %d\n", | |
ae2f5411 | 2280 | ret, (unsigned long) BTRFS_LEAF_DATA_SIZE(root), |
5f39d397 CM |
2281 | leaf_space_used(leaf, 0, nritems), nritems); |
2282 | } | |
2283 | return ret; | |
d4dbff95 CM |
2284 | } |
2285 | ||
44871b1b CM |
2286 | static noinline int __push_leaf_right(struct btrfs_trans_handle *trans, |
2287 | struct btrfs_root *root, | |
2288 | struct btrfs_path *path, | |
2289 | int data_size, int empty, | |
2290 | struct extent_buffer *right, | |
2291 | int free_space, u32 left_nritems) | |
00ec4c51 | 2292 | { |
5f39d397 | 2293 | struct extent_buffer *left = path->nodes[0]; |
44871b1b | 2294 | struct extent_buffer *upper = path->nodes[1]; |
5f39d397 | 2295 | struct btrfs_disk_key disk_key; |
00ec4c51 | 2296 | int slot; |
34a38218 | 2297 | u32 i; |
00ec4c51 CM |
2298 | int push_space = 0; |
2299 | int push_items = 0; | |
0783fcfc | 2300 | struct btrfs_item *item; |
34a38218 | 2301 | u32 nr; |
7518a238 | 2302 | u32 right_nritems; |
5f39d397 | 2303 | u32 data_end; |
db94535d | 2304 | u32 this_item_size; |
00ec4c51 | 2305 | |
34a38218 CM |
2306 | if (empty) |
2307 | nr = 0; | |
2308 | else | |
2309 | nr = 1; | |
2310 | ||
31840ae1 | 2311 | if (path->slots[0] >= left_nritems) |
87b29b20 | 2312 | push_space += data_size; |
31840ae1 | 2313 | |
44871b1b | 2314 | slot = path->slots[1]; |
34a38218 CM |
2315 | i = left_nritems - 1; |
2316 | while (i >= nr) { | |
5f39d397 | 2317 | item = btrfs_item_nr(left, i); |
db94535d | 2318 | |
31840ae1 ZY |
2319 | if (!empty && push_items > 0) { |
2320 | if (path->slots[0] > i) | |
2321 | break; | |
2322 | if (path->slots[0] == i) { | |
2323 | int space = btrfs_leaf_free_space(root, left); | |
2324 | if (space + push_space * 2 > free_space) | |
2325 | break; | |
2326 | } | |
2327 | } | |
2328 | ||
00ec4c51 | 2329 | if (path->slots[0] == i) |
87b29b20 | 2330 | push_space += data_size; |
db94535d CM |
2331 | |
2332 | if (!left->map_token) { | |
2333 | map_extent_buffer(left, (unsigned long)item, | |
2334 | sizeof(struct btrfs_item), | |
2335 | &left->map_token, &left->kaddr, | |
2336 | &left->map_start, &left->map_len, | |
2337 | KM_USER1); | |
2338 | } | |
2339 | ||
2340 | this_item_size = btrfs_item_size(left, item); | |
2341 | if (this_item_size + sizeof(*item) + push_space > free_space) | |
00ec4c51 | 2342 | break; |
31840ae1 | 2343 | |
00ec4c51 | 2344 | push_items++; |
db94535d | 2345 | push_space += this_item_size + sizeof(*item); |
34a38218 CM |
2346 | if (i == 0) |
2347 | break; | |
2348 | i--; | |
db94535d CM |
2349 | } |
2350 | if (left->map_token) { | |
2351 | unmap_extent_buffer(left, left->map_token, KM_USER1); | |
2352 | left->map_token = NULL; | |
00ec4c51 | 2353 | } |
5f39d397 | 2354 | |
925baedd CM |
2355 | if (push_items == 0) |
2356 | goto out_unlock; | |
5f39d397 | 2357 | |
34a38218 | 2358 | if (!empty && push_items == left_nritems) |
a429e513 | 2359 | WARN_ON(1); |
5f39d397 | 2360 | |
00ec4c51 | 2361 | /* push left to right */ |
5f39d397 | 2362 | right_nritems = btrfs_header_nritems(right); |
34a38218 | 2363 | |
5f39d397 | 2364 | push_space = btrfs_item_end_nr(left, left_nritems - push_items); |
123abc88 | 2365 | push_space -= leaf_data_end(root, left); |
5f39d397 | 2366 | |
00ec4c51 | 2367 | /* make room in the right data area */ |
5f39d397 CM |
2368 | data_end = leaf_data_end(root, right); |
2369 | memmove_extent_buffer(right, | |
2370 | btrfs_leaf_data(right) + data_end - push_space, | |
2371 | btrfs_leaf_data(right) + data_end, | |
2372 | BTRFS_LEAF_DATA_SIZE(root) - data_end); | |
2373 | ||
00ec4c51 | 2374 | /* copy from the left data area */ |
5f39d397 | 2375 | copy_extent_buffer(right, left, btrfs_leaf_data(right) + |
d6025579 CM |
2376 | BTRFS_LEAF_DATA_SIZE(root) - push_space, |
2377 | btrfs_leaf_data(left) + leaf_data_end(root, left), | |
2378 | push_space); | |
5f39d397 CM |
2379 | |
2380 | memmove_extent_buffer(right, btrfs_item_nr_offset(push_items), | |
2381 | btrfs_item_nr_offset(0), | |
2382 | right_nritems * sizeof(struct btrfs_item)); | |
2383 | ||
00ec4c51 | 2384 | /* copy the items from left to right */ |
5f39d397 CM |
2385 | copy_extent_buffer(right, left, btrfs_item_nr_offset(0), |
2386 | btrfs_item_nr_offset(left_nritems - push_items), | |
2387 | push_items * sizeof(struct btrfs_item)); | |
00ec4c51 CM |
2388 | |
2389 | /* update the item pointers */ | |
7518a238 | 2390 | right_nritems += push_items; |
5f39d397 | 2391 | btrfs_set_header_nritems(right, right_nritems); |
123abc88 | 2392 | push_space = BTRFS_LEAF_DATA_SIZE(root); |
7518a238 | 2393 | for (i = 0; i < right_nritems; i++) { |
5f39d397 | 2394 | item = btrfs_item_nr(right, i); |
db94535d CM |
2395 | if (!right->map_token) { |
2396 | map_extent_buffer(right, (unsigned long)item, | |
2397 | sizeof(struct btrfs_item), | |
2398 | &right->map_token, &right->kaddr, | |
2399 | &right->map_start, &right->map_len, | |
2400 | KM_USER1); | |
2401 | } | |
2402 | push_space -= btrfs_item_size(right, item); | |
2403 | btrfs_set_item_offset(right, item, push_space); | |
2404 | } | |
2405 | ||
2406 | if (right->map_token) { | |
2407 | unmap_extent_buffer(right, right->map_token, KM_USER1); | |
2408 | right->map_token = NULL; | |
00ec4c51 | 2409 | } |
7518a238 | 2410 | left_nritems -= push_items; |
5f39d397 | 2411 | btrfs_set_header_nritems(left, left_nritems); |
00ec4c51 | 2412 | |
34a38218 CM |
2413 | if (left_nritems) |
2414 | btrfs_mark_buffer_dirty(left); | |
5f39d397 | 2415 | btrfs_mark_buffer_dirty(right); |
a429e513 | 2416 | |
5f39d397 CM |
2417 | btrfs_item_key(right, &disk_key, 0); |
2418 | btrfs_set_node_key(upper, &disk_key, slot + 1); | |
d6025579 | 2419 | btrfs_mark_buffer_dirty(upper); |
02217ed2 | 2420 | |
00ec4c51 | 2421 | /* then fixup the leaf pointer in the path */ |
7518a238 CM |
2422 | if (path->slots[0] >= left_nritems) { |
2423 | path->slots[0] -= left_nritems; | |
925baedd CM |
2424 | if (btrfs_header_nritems(path->nodes[0]) == 0) |
2425 | clean_tree_block(trans, root, path->nodes[0]); | |
2426 | btrfs_tree_unlock(path->nodes[0]); | |
5f39d397 CM |
2427 | free_extent_buffer(path->nodes[0]); |
2428 | path->nodes[0] = right; | |
00ec4c51 CM |
2429 | path->slots[1] += 1; |
2430 | } else { | |
925baedd | 2431 | btrfs_tree_unlock(right); |
5f39d397 | 2432 | free_extent_buffer(right); |
00ec4c51 CM |
2433 | } |
2434 | return 0; | |
925baedd CM |
2435 | |
2436 | out_unlock: | |
2437 | btrfs_tree_unlock(right); | |
2438 | free_extent_buffer(right); | |
2439 | return 1; | |
00ec4c51 | 2440 | } |
925baedd | 2441 | |
44871b1b CM |
2442 | /* |
2443 | * push some data in the path leaf to the right, trying to free up at | |
2444 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
2445 | * | |
2446 | * returns 1 if the push failed because the other node didn't have enough | |
2447 | * room, 0 if everything worked out and < 0 if there were major errors. | |
2448 | */ | |
2449 | static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root | |
2450 | *root, struct btrfs_path *path, int data_size, | |
2451 | int empty) | |
2452 | { | |
2453 | struct extent_buffer *left = path->nodes[0]; | |
2454 | struct extent_buffer *right; | |
2455 | struct extent_buffer *upper; | |
2456 | int slot; | |
2457 | int free_space; | |
2458 | u32 left_nritems; | |
2459 | int ret; | |
2460 | ||
2461 | if (!path->nodes[1]) | |
2462 | return 1; | |
2463 | ||
2464 | slot = path->slots[1]; | |
2465 | upper = path->nodes[1]; | |
2466 | if (slot >= btrfs_header_nritems(upper) - 1) | |
2467 | return 1; | |
2468 | ||
2469 | btrfs_assert_tree_locked(path->nodes[1]); | |
2470 | ||
2471 | right = read_node_slot(root, upper, slot + 1); | |
2472 | btrfs_tree_lock(right); | |
2473 | btrfs_set_lock_blocking(right); | |
2474 | ||
2475 | free_space = btrfs_leaf_free_space(root, right); | |
2476 | if (free_space < data_size) | |
2477 | goto out_unlock; | |
2478 | ||
2479 | /* cow and double check */ | |
2480 | ret = btrfs_cow_block(trans, root, right, upper, | |
2481 | slot + 1, &right); | |
2482 | if (ret) | |
2483 | goto out_unlock; | |
2484 | ||
2485 | free_space = btrfs_leaf_free_space(root, right); | |
2486 | if (free_space < data_size) | |
2487 | goto out_unlock; | |
2488 | ||
2489 | left_nritems = btrfs_header_nritems(left); | |
2490 | if (left_nritems == 0) | |
2491 | goto out_unlock; | |
2492 | ||
2493 | return __push_leaf_right(trans, root, path, data_size, empty, | |
2494 | right, free_space, left_nritems); | |
2495 | out_unlock: | |
2496 | btrfs_tree_unlock(right); | |
2497 | free_extent_buffer(right); | |
2498 | return 1; | |
2499 | } | |
2500 | ||
74123bd7 CM |
2501 | /* |
2502 | * push some data in the path leaf to the left, trying to free up at | |
2503 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
2504 | */ | |
44871b1b CM |
2505 | static noinline int __push_leaf_left(struct btrfs_trans_handle *trans, |
2506 | struct btrfs_root *root, | |
2507 | struct btrfs_path *path, int data_size, | |
2508 | int empty, struct extent_buffer *left, | |
2509 | int free_space, int right_nritems) | |
be0e5c09 | 2510 | { |
5f39d397 CM |
2511 | struct btrfs_disk_key disk_key; |
2512 | struct extent_buffer *right = path->nodes[0]; | |
be0e5c09 CM |
2513 | int slot; |
2514 | int i; | |
be0e5c09 CM |
2515 | int push_space = 0; |
2516 | int push_items = 0; | |
0783fcfc | 2517 | struct btrfs_item *item; |
7518a238 | 2518 | u32 old_left_nritems; |
34a38218 | 2519 | u32 nr; |
aa5d6bed CM |
2520 | int ret = 0; |
2521 | int wret; | |
db94535d CM |
2522 | u32 this_item_size; |
2523 | u32 old_left_item_size; | |
be0e5c09 CM |
2524 | |
2525 | slot = path->slots[1]; | |
02217ed2 | 2526 | |
34a38218 CM |
2527 | if (empty) |
2528 | nr = right_nritems; | |
2529 | else | |
2530 | nr = right_nritems - 1; | |
2531 | ||
2532 | for (i = 0; i < nr; i++) { | |
5f39d397 | 2533 | item = btrfs_item_nr(right, i); |
db94535d CM |
2534 | if (!right->map_token) { |
2535 | map_extent_buffer(right, (unsigned long)item, | |
2536 | sizeof(struct btrfs_item), | |
2537 | &right->map_token, &right->kaddr, | |
2538 | &right->map_start, &right->map_len, | |
2539 | KM_USER1); | |
2540 | } | |
2541 | ||
31840ae1 ZY |
2542 | if (!empty && push_items > 0) { |
2543 | if (path->slots[0] < i) | |
2544 | break; | |
2545 | if (path->slots[0] == i) { | |
2546 | int space = btrfs_leaf_free_space(root, right); | |
2547 | if (space + push_space * 2 > free_space) | |
2548 | break; | |
2549 | } | |
2550 | } | |
2551 | ||
be0e5c09 | 2552 | if (path->slots[0] == i) |
87b29b20 | 2553 | push_space += data_size; |
db94535d CM |
2554 | |
2555 | this_item_size = btrfs_item_size(right, item); | |
2556 | if (this_item_size + sizeof(*item) + push_space > free_space) | |
be0e5c09 | 2557 | break; |
db94535d | 2558 | |
be0e5c09 | 2559 | push_items++; |
db94535d CM |
2560 | push_space += this_item_size + sizeof(*item); |
2561 | } | |
2562 | ||
2563 | if (right->map_token) { | |
2564 | unmap_extent_buffer(right, right->map_token, KM_USER1); | |
2565 | right->map_token = NULL; | |
be0e5c09 | 2566 | } |
db94535d | 2567 | |
be0e5c09 | 2568 | if (push_items == 0) { |
925baedd CM |
2569 | ret = 1; |
2570 | goto out; | |
be0e5c09 | 2571 | } |
34a38218 | 2572 | if (!empty && push_items == btrfs_header_nritems(right)) |
a429e513 | 2573 | WARN_ON(1); |
5f39d397 | 2574 | |
be0e5c09 | 2575 | /* push data from right to left */ |
5f39d397 CM |
2576 | copy_extent_buffer(left, right, |
2577 | btrfs_item_nr_offset(btrfs_header_nritems(left)), | |
2578 | btrfs_item_nr_offset(0), | |
2579 | push_items * sizeof(struct btrfs_item)); | |
2580 | ||
123abc88 | 2581 | push_space = BTRFS_LEAF_DATA_SIZE(root) - |
d397712b | 2582 | btrfs_item_offset_nr(right, push_items - 1); |
5f39d397 CM |
2583 | |
2584 | copy_extent_buffer(left, right, btrfs_leaf_data(left) + | |
d6025579 CM |
2585 | leaf_data_end(root, left) - push_space, |
2586 | btrfs_leaf_data(right) + | |
5f39d397 | 2587 | btrfs_item_offset_nr(right, push_items - 1), |
d6025579 | 2588 | push_space); |
5f39d397 | 2589 | old_left_nritems = btrfs_header_nritems(left); |
87b29b20 | 2590 | BUG_ON(old_left_nritems <= 0); |
eb60ceac | 2591 | |
db94535d | 2592 | old_left_item_size = btrfs_item_offset_nr(left, old_left_nritems - 1); |
0783fcfc | 2593 | for (i = old_left_nritems; i < old_left_nritems + push_items; i++) { |
5f39d397 | 2594 | u32 ioff; |
db94535d | 2595 | |
5f39d397 | 2596 | item = btrfs_item_nr(left, i); |
db94535d CM |
2597 | if (!left->map_token) { |
2598 | map_extent_buffer(left, (unsigned long)item, | |
2599 | sizeof(struct btrfs_item), | |
2600 | &left->map_token, &left->kaddr, | |
2601 | &left->map_start, &left->map_len, | |
2602 | KM_USER1); | |
2603 | } | |
2604 | ||
5f39d397 CM |
2605 | ioff = btrfs_item_offset(left, item); |
2606 | btrfs_set_item_offset(left, item, | |
db94535d | 2607 | ioff - (BTRFS_LEAF_DATA_SIZE(root) - old_left_item_size)); |
be0e5c09 | 2608 | } |
5f39d397 | 2609 | btrfs_set_header_nritems(left, old_left_nritems + push_items); |
db94535d CM |
2610 | if (left->map_token) { |
2611 | unmap_extent_buffer(left, left->map_token, KM_USER1); | |
2612 | left->map_token = NULL; | |
2613 | } | |
be0e5c09 CM |
2614 | |
2615 | /* fixup right node */ | |
34a38218 | 2616 | if (push_items > right_nritems) { |
d397712b CM |
2617 | printk(KERN_CRIT "push items %d nr %u\n", push_items, |
2618 | right_nritems); | |
34a38218 CM |
2619 | WARN_ON(1); |
2620 | } | |
2621 | ||
2622 | if (push_items < right_nritems) { | |
2623 | push_space = btrfs_item_offset_nr(right, push_items - 1) - | |
2624 | leaf_data_end(root, right); | |
2625 | memmove_extent_buffer(right, btrfs_leaf_data(right) + | |
2626 | BTRFS_LEAF_DATA_SIZE(root) - push_space, | |
2627 | btrfs_leaf_data(right) + | |
2628 | leaf_data_end(root, right), push_space); | |
2629 | ||
2630 | memmove_extent_buffer(right, btrfs_item_nr_offset(0), | |
5f39d397 CM |
2631 | btrfs_item_nr_offset(push_items), |
2632 | (btrfs_header_nritems(right) - push_items) * | |
2633 | sizeof(struct btrfs_item)); | |
34a38218 | 2634 | } |
eef1c494 Y |
2635 | right_nritems -= push_items; |
2636 | btrfs_set_header_nritems(right, right_nritems); | |
123abc88 | 2637 | push_space = BTRFS_LEAF_DATA_SIZE(root); |
5f39d397 CM |
2638 | for (i = 0; i < right_nritems; i++) { |
2639 | item = btrfs_item_nr(right, i); | |
db94535d CM |
2640 | |
2641 | if (!right->map_token) { | |
2642 | map_extent_buffer(right, (unsigned long)item, | |
2643 | sizeof(struct btrfs_item), | |
2644 | &right->map_token, &right->kaddr, | |
2645 | &right->map_start, &right->map_len, | |
2646 | KM_USER1); | |
2647 | } | |
2648 | ||
2649 | push_space = push_space - btrfs_item_size(right, item); | |
2650 | btrfs_set_item_offset(right, item, push_space); | |
2651 | } | |
2652 | if (right->map_token) { | |
2653 | unmap_extent_buffer(right, right->map_token, KM_USER1); | |
2654 | right->map_token = NULL; | |
be0e5c09 | 2655 | } |
eb60ceac | 2656 | |
5f39d397 | 2657 | btrfs_mark_buffer_dirty(left); |
34a38218 CM |
2658 | if (right_nritems) |
2659 | btrfs_mark_buffer_dirty(right); | |
098f59c2 | 2660 | |
5f39d397 CM |
2661 | btrfs_item_key(right, &disk_key, 0); |
2662 | wret = fixup_low_keys(trans, root, path, &disk_key, 1); | |
aa5d6bed CM |
2663 | if (wret) |
2664 | ret = wret; | |
be0e5c09 CM |
2665 | |
2666 | /* then fixup the leaf pointer in the path */ | |
2667 | if (path->slots[0] < push_items) { | |
2668 | path->slots[0] += old_left_nritems; | |
925baedd CM |
2669 | if (btrfs_header_nritems(path->nodes[0]) == 0) |
2670 | clean_tree_block(trans, root, path->nodes[0]); | |
2671 | btrfs_tree_unlock(path->nodes[0]); | |
5f39d397 CM |
2672 | free_extent_buffer(path->nodes[0]); |
2673 | path->nodes[0] = left; | |
be0e5c09 CM |
2674 | path->slots[1] -= 1; |
2675 | } else { | |
925baedd | 2676 | btrfs_tree_unlock(left); |
5f39d397 | 2677 | free_extent_buffer(left); |
be0e5c09 CM |
2678 | path->slots[0] -= push_items; |
2679 | } | |
eb60ceac | 2680 | BUG_ON(path->slots[0] < 0); |
aa5d6bed | 2681 | return ret; |
925baedd CM |
2682 | out: |
2683 | btrfs_tree_unlock(left); | |
2684 | free_extent_buffer(left); | |
2685 | return ret; | |
be0e5c09 CM |
2686 | } |
2687 | ||
44871b1b CM |
2688 | /* |
2689 | * push some data in the path leaf to the left, trying to free up at | |
2690 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
2691 | */ | |
2692 | static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root | |
2693 | *root, struct btrfs_path *path, int data_size, | |
2694 | int empty) | |
2695 | { | |
2696 | struct extent_buffer *right = path->nodes[0]; | |
2697 | struct extent_buffer *left; | |
2698 | int slot; | |
2699 | int free_space; | |
2700 | u32 right_nritems; | |
2701 | int ret = 0; | |
2702 | ||
2703 | slot = path->slots[1]; | |
2704 | if (slot == 0) | |
2705 | return 1; | |
2706 | if (!path->nodes[1]) | |
2707 | return 1; | |
2708 | ||
2709 | right_nritems = btrfs_header_nritems(right); | |
2710 | if (right_nritems == 0) | |
2711 | return 1; | |
2712 | ||
2713 | btrfs_assert_tree_locked(path->nodes[1]); | |
2714 | ||
2715 | left = read_node_slot(root, path->nodes[1], slot - 1); | |
2716 | btrfs_tree_lock(left); | |
2717 | btrfs_set_lock_blocking(left); | |
2718 | ||
2719 | free_space = btrfs_leaf_free_space(root, left); | |
2720 | if (free_space < data_size) { | |
2721 | ret = 1; | |
2722 | goto out; | |
2723 | } | |
2724 | ||
2725 | /* cow and double check */ | |
2726 | ret = btrfs_cow_block(trans, root, left, | |
2727 | path->nodes[1], slot - 1, &left); | |
2728 | if (ret) { | |
2729 | /* we hit -ENOSPC, but it isn't fatal here */ | |
2730 | ret = 1; | |
2731 | goto out; | |
2732 | } | |
2733 | ||
2734 | free_space = btrfs_leaf_free_space(root, left); | |
2735 | if (free_space < data_size) { | |
2736 | ret = 1; | |
2737 | goto out; | |
2738 | } | |
2739 | ||
2740 | return __push_leaf_left(trans, root, path, data_size, | |
2741 | empty, left, free_space, right_nritems); | |
2742 | out: | |
2743 | btrfs_tree_unlock(left); | |
2744 | free_extent_buffer(left); | |
2745 | return ret; | |
2746 | } | |
2747 | ||
2748 | /* | |
2749 | * split the path's leaf in two, making sure there is at least data_size | |
2750 | * available for the resulting leaf level of the path. | |
2751 | * | |
2752 | * returns 0 if all went well and < 0 on failure. | |
2753 | */ | |
2754 | static noinline int copy_for_split(struct btrfs_trans_handle *trans, | |
2755 | struct btrfs_root *root, | |
2756 | struct btrfs_path *path, | |
2757 | struct extent_buffer *l, | |
2758 | struct extent_buffer *right, | |
2759 | int slot, int mid, int nritems) | |
2760 | { | |
2761 | int data_copy_size; | |
2762 | int rt_data_off; | |
2763 | int i; | |
2764 | int ret = 0; | |
2765 | int wret; | |
2766 | struct btrfs_disk_key disk_key; | |
2767 | ||
2768 | nritems = nritems - mid; | |
2769 | btrfs_set_header_nritems(right, nritems); | |
2770 | data_copy_size = btrfs_item_end_nr(l, mid) - leaf_data_end(root, l); | |
2771 | ||
2772 | copy_extent_buffer(right, l, btrfs_item_nr_offset(0), | |
2773 | btrfs_item_nr_offset(mid), | |
2774 | nritems * sizeof(struct btrfs_item)); | |
2775 | ||
2776 | copy_extent_buffer(right, l, | |
2777 | btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) - | |
2778 | data_copy_size, btrfs_leaf_data(l) + | |
2779 | leaf_data_end(root, l), data_copy_size); | |
2780 | ||
2781 | rt_data_off = BTRFS_LEAF_DATA_SIZE(root) - | |
2782 | btrfs_item_end_nr(l, mid); | |
2783 | ||
2784 | for (i = 0; i < nritems; i++) { | |
2785 | struct btrfs_item *item = btrfs_item_nr(right, i); | |
2786 | u32 ioff; | |
2787 | ||
2788 | if (!right->map_token) { | |
2789 | map_extent_buffer(right, (unsigned long)item, | |
2790 | sizeof(struct btrfs_item), | |
2791 | &right->map_token, &right->kaddr, | |
2792 | &right->map_start, &right->map_len, | |
2793 | KM_USER1); | |
2794 | } | |
2795 | ||
2796 | ioff = btrfs_item_offset(right, item); | |
2797 | btrfs_set_item_offset(right, item, ioff + rt_data_off); | |
2798 | } | |
2799 | ||
2800 | if (right->map_token) { | |
2801 | unmap_extent_buffer(right, right->map_token, KM_USER1); | |
2802 | right->map_token = NULL; | |
2803 | } | |
2804 | ||
2805 | btrfs_set_header_nritems(l, mid); | |
2806 | ret = 0; | |
2807 | btrfs_item_key(right, &disk_key, 0); | |
2808 | wret = insert_ptr(trans, root, path, &disk_key, right->start, | |
2809 | path->slots[1] + 1, 1); | |
2810 | if (wret) | |
2811 | ret = wret; | |
2812 | ||
2813 | btrfs_mark_buffer_dirty(right); | |
2814 | btrfs_mark_buffer_dirty(l); | |
2815 | BUG_ON(path->slots[0] != slot); | |
2816 | ||
44871b1b CM |
2817 | if (mid <= slot) { |
2818 | btrfs_tree_unlock(path->nodes[0]); | |
2819 | free_extent_buffer(path->nodes[0]); | |
2820 | path->nodes[0] = right; | |
2821 | path->slots[0] -= mid; | |
2822 | path->slots[1] += 1; | |
2823 | } else { | |
2824 | btrfs_tree_unlock(right); | |
2825 | free_extent_buffer(right); | |
2826 | } | |
2827 | ||
2828 | BUG_ON(path->slots[0] < 0); | |
2829 | ||
2830 | return ret; | |
2831 | } | |
2832 | ||
74123bd7 CM |
2833 | /* |
2834 | * split the path's leaf in two, making sure there is at least data_size | |
2835 | * available for the resulting leaf level of the path. | |
aa5d6bed CM |
2836 | * |
2837 | * returns 0 if all went well and < 0 on failure. | |
74123bd7 | 2838 | */ |
e02119d5 CM |
2839 | static noinline int split_leaf(struct btrfs_trans_handle *trans, |
2840 | struct btrfs_root *root, | |
2841 | struct btrfs_key *ins_key, | |
2842 | struct btrfs_path *path, int data_size, | |
2843 | int extend) | |
be0e5c09 | 2844 | { |
5d4f98a2 | 2845 | struct btrfs_disk_key disk_key; |
5f39d397 | 2846 | struct extent_buffer *l; |
7518a238 | 2847 | u32 nritems; |
eb60ceac CM |
2848 | int mid; |
2849 | int slot; | |
5f39d397 | 2850 | struct extent_buffer *right; |
d4dbff95 | 2851 | int ret = 0; |
aa5d6bed | 2852 | int wret; |
5d4f98a2 | 2853 | int split; |
cc0c5538 | 2854 | int num_doubles = 0; |
aa5d6bed | 2855 | |
a5719521 YZ |
2856 | l = path->nodes[0]; |
2857 | slot = path->slots[0]; | |
2858 | if (extend && data_size + btrfs_item_size_nr(l, slot) + | |
2859 | sizeof(struct btrfs_item) > BTRFS_LEAF_DATA_SIZE(root)) | |
2860 | return -EOVERFLOW; | |
2861 | ||
40689478 | 2862 | /* first try to make some room by pushing left and right */ |
b3612421 | 2863 | if (data_size && ins_key->type != BTRFS_DIR_ITEM_KEY) { |
34a38218 | 2864 | wret = push_leaf_right(trans, root, path, data_size, 0); |
d397712b | 2865 | if (wret < 0) |
eaee50e8 | 2866 | return wret; |
3685f791 | 2867 | if (wret) { |
34a38218 | 2868 | wret = push_leaf_left(trans, root, path, data_size, 0); |
3685f791 CM |
2869 | if (wret < 0) |
2870 | return wret; | |
2871 | } | |
2872 | l = path->nodes[0]; | |
aa5d6bed | 2873 | |
3685f791 | 2874 | /* did the pushes work? */ |
87b29b20 | 2875 | if (btrfs_leaf_free_space(root, l) >= data_size) |
3685f791 | 2876 | return 0; |
3326d1b0 | 2877 | } |
aa5d6bed | 2878 | |
5c680ed6 | 2879 | if (!path->nodes[1]) { |
e089f05c | 2880 | ret = insert_new_root(trans, root, path, 1); |
5c680ed6 CM |
2881 | if (ret) |
2882 | return ret; | |
2883 | } | |
cc0c5538 | 2884 | again: |
5d4f98a2 | 2885 | split = 1; |
cc0c5538 | 2886 | l = path->nodes[0]; |
eb60ceac | 2887 | slot = path->slots[0]; |
5f39d397 | 2888 | nritems = btrfs_header_nritems(l); |
d397712b | 2889 | mid = (nritems + 1) / 2; |
54aa1f4d | 2890 | |
5d4f98a2 YZ |
2891 | if (mid <= slot) { |
2892 | if (nritems == 1 || | |
2893 | leaf_space_used(l, mid, nritems - mid) + data_size > | |
2894 | BTRFS_LEAF_DATA_SIZE(root)) { | |
2895 | if (slot >= nritems) { | |
2896 | split = 0; | |
2897 | } else { | |
2898 | mid = slot; | |
2899 | if (mid != nritems && | |
2900 | leaf_space_used(l, mid, nritems - mid) + | |
2901 | data_size > BTRFS_LEAF_DATA_SIZE(root)) { | |
2902 | split = 2; | |
2903 | } | |
2904 | } | |
2905 | } | |
2906 | } else { | |
2907 | if (leaf_space_used(l, 0, mid) + data_size > | |
2908 | BTRFS_LEAF_DATA_SIZE(root)) { | |
2909 | if (!extend && data_size && slot == 0) { | |
2910 | split = 0; | |
2911 | } else if ((extend || !data_size) && slot == 0) { | |
2912 | mid = 1; | |
2913 | } else { | |
2914 | mid = slot; | |
2915 | if (mid != nritems && | |
2916 | leaf_space_used(l, mid, nritems - mid) + | |
2917 | data_size > BTRFS_LEAF_DATA_SIZE(root)) { | |
2918 | split = 2 ; | |
2919 | } | |
2920 | } | |
2921 | } | |
2922 | } | |
2923 | ||
2924 | if (split == 0) | |
2925 | btrfs_cpu_key_to_disk(&disk_key, ins_key); | |
2926 | else | |
2927 | btrfs_item_key(l, &disk_key, mid); | |
2928 | ||
2929 | right = btrfs_alloc_free_block(trans, root, root->leafsize, 0, | |
31840ae1 | 2930 | root->root_key.objectid, |
5d4f98a2 | 2931 | &disk_key, 0, l->start, 0); |
cea9e445 CM |
2932 | if (IS_ERR(right)) { |
2933 | BUG_ON(1); | |
5f39d397 | 2934 | return PTR_ERR(right); |
cea9e445 | 2935 | } |
5f39d397 CM |
2936 | |
2937 | memset_extent_buffer(right, 0, 0, sizeof(struct btrfs_header)); | |
db94535d | 2938 | btrfs_set_header_bytenr(right, right->start); |
5f39d397 | 2939 | btrfs_set_header_generation(right, trans->transid); |
5d4f98a2 | 2940 | btrfs_set_header_backref_rev(right, BTRFS_MIXED_BACKREF_REV); |
5f39d397 CM |
2941 | btrfs_set_header_owner(right, root->root_key.objectid); |
2942 | btrfs_set_header_level(right, 0); | |
2943 | write_extent_buffer(right, root->fs_info->fsid, | |
2944 | (unsigned long)btrfs_header_fsid(right), | |
2945 | BTRFS_FSID_SIZE); | |
e17cade2 CM |
2946 | |
2947 | write_extent_buffer(right, root->fs_info->chunk_tree_uuid, | |
2948 | (unsigned long)btrfs_header_chunk_tree_uuid(right), | |
2949 | BTRFS_UUID_SIZE); | |
44871b1b | 2950 | |
5d4f98a2 YZ |
2951 | if (split == 0) { |
2952 | if (mid <= slot) { | |
2953 | btrfs_set_header_nritems(right, 0); | |
2954 | wret = insert_ptr(trans, root, path, | |
2955 | &disk_key, right->start, | |
2956 | path->slots[1] + 1, 1); | |
2957 | if (wret) | |
2958 | ret = wret; | |
925baedd | 2959 | |
5d4f98a2 YZ |
2960 | btrfs_tree_unlock(path->nodes[0]); |
2961 | free_extent_buffer(path->nodes[0]); | |
2962 | path->nodes[0] = right; | |
2963 | path->slots[0] = 0; | |
2964 | path->slots[1] += 1; | |
2965 | } else { | |
2966 | btrfs_set_header_nritems(right, 0); | |
2967 | wret = insert_ptr(trans, root, path, | |
2968 | &disk_key, | |
2969 | right->start, | |
2970 | path->slots[1], 1); | |
2971 | if (wret) | |
2972 | ret = wret; | |
2973 | btrfs_tree_unlock(path->nodes[0]); | |
2974 | free_extent_buffer(path->nodes[0]); | |
2975 | path->nodes[0] = right; | |
2976 | path->slots[0] = 0; | |
2977 | if (path->slots[1] == 0) { | |
2978 | wret = fixup_low_keys(trans, root, | |
2979 | path, &disk_key, 1); | |
d4dbff95 CM |
2980 | if (wret) |
2981 | ret = wret; | |
5ee78ac7 | 2982 | } |
d4dbff95 | 2983 | } |
5d4f98a2 YZ |
2984 | btrfs_mark_buffer_dirty(right); |
2985 | return ret; | |
d4dbff95 | 2986 | } |
74123bd7 | 2987 | |
44871b1b | 2988 | ret = copy_for_split(trans, root, path, l, right, slot, mid, nritems); |
31840ae1 ZY |
2989 | BUG_ON(ret); |
2990 | ||
5d4f98a2 | 2991 | if (split == 2) { |
cc0c5538 CM |
2992 | BUG_ON(num_doubles != 0); |
2993 | num_doubles++; | |
2994 | goto again; | |
a429e513 | 2995 | } |
44871b1b | 2996 | |
be0e5c09 CM |
2997 | return ret; |
2998 | } | |
2999 | ||
459931ec CM |
3000 | /* |
3001 | * This function splits a single item into two items, | |
3002 | * giving 'new_key' to the new item and splitting the | |
3003 | * old one at split_offset (from the start of the item). | |
3004 | * | |
3005 | * The path may be released by this operation. After | |
3006 | * the split, the path is pointing to the old item. The | |
3007 | * new item is going to be in the same node as the old one. | |
3008 | * | |
3009 | * Note, the item being split must be smaller enough to live alone on | |
3010 | * a tree block with room for one extra struct btrfs_item | |
3011 | * | |
3012 | * This allows us to split the item in place, keeping a lock on the | |
3013 | * leaf the entire time. | |
3014 | */ | |
3015 | int btrfs_split_item(struct btrfs_trans_handle *trans, | |
3016 | struct btrfs_root *root, | |
3017 | struct btrfs_path *path, | |
3018 | struct btrfs_key *new_key, | |
3019 | unsigned long split_offset) | |
3020 | { | |
3021 | u32 item_size; | |
3022 | struct extent_buffer *leaf; | |
3023 | struct btrfs_key orig_key; | |
3024 | struct btrfs_item *item; | |
3025 | struct btrfs_item *new_item; | |
3026 | int ret = 0; | |
3027 | int slot; | |
3028 | u32 nritems; | |
3029 | u32 orig_offset; | |
3030 | struct btrfs_disk_key disk_key; | |
3031 | char *buf; | |
3032 | ||
3033 | leaf = path->nodes[0]; | |
3034 | btrfs_item_key_to_cpu(leaf, &orig_key, path->slots[0]); | |
3035 | if (btrfs_leaf_free_space(root, leaf) >= sizeof(struct btrfs_item)) | |
3036 | goto split; | |
3037 | ||
3038 | item_size = btrfs_item_size_nr(leaf, path->slots[0]); | |
3039 | btrfs_release_path(root, path); | |
3040 | ||
3041 | path->search_for_split = 1; | |
3042 | path->keep_locks = 1; | |
3043 | ||
3044 | ret = btrfs_search_slot(trans, root, &orig_key, path, 0, 1); | |
3045 | path->search_for_split = 0; | |
3046 | ||
3047 | /* if our item isn't there or got smaller, return now */ | |
3048 | if (ret != 0 || item_size != btrfs_item_size_nr(path->nodes[0], | |
3049 | path->slots[0])) { | |
3050 | path->keep_locks = 0; | |
3051 | return -EAGAIN; | |
3052 | } | |
3053 | ||
b9473439 | 3054 | btrfs_set_path_blocking(path); |
87b29b20 YZ |
3055 | ret = split_leaf(trans, root, &orig_key, path, |
3056 | sizeof(struct btrfs_item), 1); | |
459931ec CM |
3057 | path->keep_locks = 0; |
3058 | BUG_ON(ret); | |
3059 | ||
b9473439 CM |
3060 | btrfs_unlock_up_safe(path, 1); |
3061 | leaf = path->nodes[0]; | |
3062 | BUG_ON(btrfs_leaf_free_space(root, leaf) < sizeof(struct btrfs_item)); | |
3063 | ||
3064 | split: | |
b4ce94de CM |
3065 | /* |
3066 | * make sure any changes to the path from split_leaf leave it | |
3067 | * in a blocking state | |
3068 | */ | |
3069 | btrfs_set_path_blocking(path); | |
3070 | ||
459931ec CM |
3071 | item = btrfs_item_nr(leaf, path->slots[0]); |
3072 | orig_offset = btrfs_item_offset(leaf, item); | |
3073 | item_size = btrfs_item_size(leaf, item); | |
3074 | ||
459931ec CM |
3075 | buf = kmalloc(item_size, GFP_NOFS); |
3076 | read_extent_buffer(leaf, buf, btrfs_item_ptr_offset(leaf, | |
3077 | path->slots[0]), item_size); | |
3078 | slot = path->slots[0] + 1; | |
3079 | leaf = path->nodes[0]; | |
3080 | ||
3081 | nritems = btrfs_header_nritems(leaf); | |
3082 | ||
3083 | if (slot != nritems) { | |
3084 | /* shift the items */ | |
3085 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + 1), | |
3086 | btrfs_item_nr_offset(slot), | |
3087 | (nritems - slot) * sizeof(struct btrfs_item)); | |
3088 | ||
3089 | } | |
3090 | ||
3091 | btrfs_cpu_key_to_disk(&disk_key, new_key); | |
3092 | btrfs_set_item_key(leaf, &disk_key, slot); | |
3093 | ||
3094 | new_item = btrfs_item_nr(leaf, slot); | |
3095 | ||
3096 | btrfs_set_item_offset(leaf, new_item, orig_offset); | |
3097 | btrfs_set_item_size(leaf, new_item, item_size - split_offset); | |
3098 | ||
3099 | btrfs_set_item_offset(leaf, item, | |
3100 | orig_offset + item_size - split_offset); | |
3101 | btrfs_set_item_size(leaf, item, split_offset); | |
3102 | ||
3103 | btrfs_set_header_nritems(leaf, nritems + 1); | |
3104 | ||
3105 | /* write the data for the start of the original item */ | |
3106 | write_extent_buffer(leaf, buf, | |
3107 | btrfs_item_ptr_offset(leaf, path->slots[0]), | |
3108 | split_offset); | |
3109 | ||
3110 | /* write the data for the new item */ | |
3111 | write_extent_buffer(leaf, buf + split_offset, | |
3112 | btrfs_item_ptr_offset(leaf, slot), | |
3113 | item_size - split_offset); | |
3114 | btrfs_mark_buffer_dirty(leaf); | |
3115 | ||
3116 | ret = 0; | |
3117 | if (btrfs_leaf_free_space(root, leaf) < 0) { | |
3118 | btrfs_print_leaf(root, leaf); | |
3119 | BUG(); | |
3120 | } | |
3121 | kfree(buf); | |
3122 | return ret; | |
3123 | } | |
3124 | ||
d352ac68 CM |
3125 | /* |
3126 | * make the item pointed to by the path smaller. new_size indicates | |
3127 | * how small to make it, and from_end tells us if we just chop bytes | |
3128 | * off the end of the item or if we shift the item to chop bytes off | |
3129 | * the front. | |
3130 | */ | |
b18c6685 CM |
3131 | int btrfs_truncate_item(struct btrfs_trans_handle *trans, |
3132 | struct btrfs_root *root, | |
3133 | struct btrfs_path *path, | |
179e29e4 | 3134 | u32 new_size, int from_end) |
b18c6685 CM |
3135 | { |
3136 | int ret = 0; | |
3137 | int slot; | |
3138 | int slot_orig; | |
5f39d397 CM |
3139 | struct extent_buffer *leaf; |
3140 | struct btrfs_item *item; | |
b18c6685 CM |
3141 | u32 nritems; |
3142 | unsigned int data_end; | |
3143 | unsigned int old_data_start; | |
3144 | unsigned int old_size; | |
3145 | unsigned int size_diff; | |
3146 | int i; | |
3147 | ||
3148 | slot_orig = path->slots[0]; | |
5f39d397 | 3149 | leaf = path->nodes[0]; |
179e29e4 CM |
3150 | slot = path->slots[0]; |
3151 | ||
3152 | old_size = btrfs_item_size_nr(leaf, slot); | |
3153 | if (old_size == new_size) | |
3154 | return 0; | |
b18c6685 | 3155 | |
5f39d397 | 3156 | nritems = btrfs_header_nritems(leaf); |
b18c6685 CM |
3157 | data_end = leaf_data_end(root, leaf); |
3158 | ||
5f39d397 | 3159 | old_data_start = btrfs_item_offset_nr(leaf, slot); |
179e29e4 | 3160 | |
b18c6685 CM |
3161 | size_diff = old_size - new_size; |
3162 | ||
3163 | BUG_ON(slot < 0); | |
3164 | BUG_ON(slot >= nritems); | |
3165 | ||
3166 | /* | |
3167 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
3168 | */ | |
3169 | /* first correct the data pointers */ | |
3170 | for (i = slot; i < nritems; i++) { | |
5f39d397 CM |
3171 | u32 ioff; |
3172 | item = btrfs_item_nr(leaf, i); | |
db94535d CM |
3173 | |
3174 | if (!leaf->map_token) { | |
3175 | map_extent_buffer(leaf, (unsigned long)item, | |
3176 | sizeof(struct btrfs_item), | |
3177 | &leaf->map_token, &leaf->kaddr, | |
3178 | &leaf->map_start, &leaf->map_len, | |
3179 | KM_USER1); | |
3180 | } | |
3181 | ||
5f39d397 CM |
3182 | ioff = btrfs_item_offset(leaf, item); |
3183 | btrfs_set_item_offset(leaf, item, ioff + size_diff); | |
b18c6685 | 3184 | } |
db94535d CM |
3185 | |
3186 | if (leaf->map_token) { | |
3187 | unmap_extent_buffer(leaf, leaf->map_token, KM_USER1); | |
3188 | leaf->map_token = NULL; | |
3189 | } | |
3190 | ||
b18c6685 | 3191 | /* shift the data */ |
179e29e4 CM |
3192 | if (from_end) { |
3193 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + | |
3194 | data_end + size_diff, btrfs_leaf_data(leaf) + | |
3195 | data_end, old_data_start + new_size - data_end); | |
3196 | } else { | |
3197 | struct btrfs_disk_key disk_key; | |
3198 | u64 offset; | |
3199 | ||
3200 | btrfs_item_key(leaf, &disk_key, slot); | |
3201 | ||
3202 | if (btrfs_disk_key_type(&disk_key) == BTRFS_EXTENT_DATA_KEY) { | |
3203 | unsigned long ptr; | |
3204 | struct btrfs_file_extent_item *fi; | |
3205 | ||
3206 | fi = btrfs_item_ptr(leaf, slot, | |
3207 | struct btrfs_file_extent_item); | |
3208 | fi = (struct btrfs_file_extent_item *)( | |
3209 | (unsigned long)fi - size_diff); | |
3210 | ||
3211 | if (btrfs_file_extent_type(leaf, fi) == | |
3212 | BTRFS_FILE_EXTENT_INLINE) { | |
3213 | ptr = btrfs_item_ptr_offset(leaf, slot); | |
3214 | memmove_extent_buffer(leaf, ptr, | |
d397712b CM |
3215 | (unsigned long)fi, |
3216 | offsetof(struct btrfs_file_extent_item, | |
179e29e4 CM |
3217 | disk_bytenr)); |
3218 | } | |
3219 | } | |
3220 | ||
3221 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + | |
3222 | data_end + size_diff, btrfs_leaf_data(leaf) + | |
3223 | data_end, old_data_start - data_end); | |
3224 | ||
3225 | offset = btrfs_disk_key_offset(&disk_key); | |
3226 | btrfs_set_disk_key_offset(&disk_key, offset + size_diff); | |
3227 | btrfs_set_item_key(leaf, &disk_key, slot); | |
3228 | if (slot == 0) | |
3229 | fixup_low_keys(trans, root, path, &disk_key, 1); | |
3230 | } | |
5f39d397 CM |
3231 | |
3232 | item = btrfs_item_nr(leaf, slot); | |
3233 | btrfs_set_item_size(leaf, item, new_size); | |
3234 | btrfs_mark_buffer_dirty(leaf); | |
b18c6685 CM |
3235 | |
3236 | ret = 0; | |
5f39d397 CM |
3237 | if (btrfs_leaf_free_space(root, leaf) < 0) { |
3238 | btrfs_print_leaf(root, leaf); | |
b18c6685 | 3239 | BUG(); |
5f39d397 | 3240 | } |
b18c6685 CM |
3241 | return ret; |
3242 | } | |
3243 | ||
d352ac68 CM |
3244 | /* |
3245 | * make the item pointed to by the path bigger, data_size is the new size. | |
3246 | */ | |
5f39d397 CM |
3247 | int btrfs_extend_item(struct btrfs_trans_handle *trans, |
3248 | struct btrfs_root *root, struct btrfs_path *path, | |
3249 | u32 data_size) | |
6567e837 CM |
3250 | { |
3251 | int ret = 0; | |
3252 | int slot; | |
3253 | int slot_orig; | |
5f39d397 CM |
3254 | struct extent_buffer *leaf; |
3255 | struct btrfs_item *item; | |
6567e837 CM |
3256 | u32 nritems; |
3257 | unsigned int data_end; | |
3258 | unsigned int old_data; | |
3259 | unsigned int old_size; | |
3260 | int i; | |
3261 | ||
3262 | slot_orig = path->slots[0]; | |
5f39d397 | 3263 | leaf = path->nodes[0]; |
6567e837 | 3264 | |
5f39d397 | 3265 | nritems = btrfs_header_nritems(leaf); |
6567e837 CM |
3266 | data_end = leaf_data_end(root, leaf); |
3267 | ||
5f39d397 CM |
3268 | if (btrfs_leaf_free_space(root, leaf) < data_size) { |
3269 | btrfs_print_leaf(root, leaf); | |
6567e837 | 3270 | BUG(); |
5f39d397 | 3271 | } |
6567e837 | 3272 | slot = path->slots[0]; |
5f39d397 | 3273 | old_data = btrfs_item_end_nr(leaf, slot); |
6567e837 CM |
3274 | |
3275 | BUG_ON(slot < 0); | |
3326d1b0 CM |
3276 | if (slot >= nritems) { |
3277 | btrfs_print_leaf(root, leaf); | |
d397712b CM |
3278 | printk(KERN_CRIT "slot %d too large, nritems %d\n", |
3279 | slot, nritems); | |
3326d1b0 CM |
3280 | BUG_ON(1); |
3281 | } | |
6567e837 CM |
3282 | |
3283 | /* | |
3284 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
3285 | */ | |
3286 | /* first correct the data pointers */ | |
3287 | for (i = slot; i < nritems; i++) { | |
5f39d397 CM |
3288 | u32 ioff; |
3289 | item = btrfs_item_nr(leaf, i); | |
db94535d CM |
3290 | |
3291 | if (!leaf->map_token) { | |
3292 | map_extent_buffer(leaf, (unsigned long)item, | |
3293 | sizeof(struct btrfs_item), | |
3294 | &leaf->map_token, &leaf->kaddr, | |
3295 | &leaf->map_start, &leaf->map_len, | |
3296 | KM_USER1); | |
3297 | } | |
5f39d397 CM |
3298 | ioff = btrfs_item_offset(leaf, item); |
3299 | btrfs_set_item_offset(leaf, item, ioff - data_size); | |
6567e837 | 3300 | } |
5f39d397 | 3301 | |
db94535d CM |
3302 | if (leaf->map_token) { |
3303 | unmap_extent_buffer(leaf, leaf->map_token, KM_USER1); | |
3304 | leaf->map_token = NULL; | |
3305 | } | |
3306 | ||
6567e837 | 3307 | /* shift the data */ |
5f39d397 | 3308 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + |
6567e837 CM |
3309 | data_end - data_size, btrfs_leaf_data(leaf) + |
3310 | data_end, old_data - data_end); | |
5f39d397 | 3311 | |
6567e837 | 3312 | data_end = old_data; |
5f39d397 CM |
3313 | old_size = btrfs_item_size_nr(leaf, slot); |
3314 | item = btrfs_item_nr(leaf, slot); | |
3315 | btrfs_set_item_size(leaf, item, old_size + data_size); | |
3316 | btrfs_mark_buffer_dirty(leaf); | |
6567e837 CM |
3317 | |
3318 | ret = 0; | |
5f39d397 CM |
3319 | if (btrfs_leaf_free_space(root, leaf) < 0) { |
3320 | btrfs_print_leaf(root, leaf); | |
6567e837 | 3321 | BUG(); |
5f39d397 | 3322 | } |
6567e837 CM |
3323 | return ret; |
3324 | } | |
3325 | ||
f3465ca4 JB |
3326 | /* |
3327 | * Given a key and some data, insert items into the tree. | |
3328 | * This does all the path init required, making room in the tree if needed. | |
3329 | * Returns the number of keys that were inserted. | |
3330 | */ | |
3331 | int btrfs_insert_some_items(struct btrfs_trans_handle *trans, | |
3332 | struct btrfs_root *root, | |
3333 | struct btrfs_path *path, | |
3334 | struct btrfs_key *cpu_key, u32 *data_size, | |
3335 | int nr) | |
3336 | { | |
3337 | struct extent_buffer *leaf; | |
3338 | struct btrfs_item *item; | |
3339 | int ret = 0; | |
3340 | int slot; | |
f3465ca4 JB |
3341 | int i; |
3342 | u32 nritems; | |
3343 | u32 total_data = 0; | |
3344 | u32 total_size = 0; | |
3345 | unsigned int data_end; | |
3346 | struct btrfs_disk_key disk_key; | |
3347 | struct btrfs_key found_key; | |
3348 | ||
87b29b20 YZ |
3349 | for (i = 0; i < nr; i++) { |
3350 | if (total_size + data_size[i] + sizeof(struct btrfs_item) > | |
3351 | BTRFS_LEAF_DATA_SIZE(root)) { | |
3352 | break; | |
3353 | nr = i; | |
3354 | } | |
f3465ca4 | 3355 | total_data += data_size[i]; |
87b29b20 YZ |
3356 | total_size += data_size[i] + sizeof(struct btrfs_item); |
3357 | } | |
3358 | BUG_ON(nr == 0); | |
f3465ca4 | 3359 | |
f3465ca4 JB |
3360 | ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1); |
3361 | if (ret == 0) | |
3362 | return -EEXIST; | |
3363 | if (ret < 0) | |
3364 | goto out; | |
3365 | ||
f3465ca4 JB |
3366 | leaf = path->nodes[0]; |
3367 | ||
3368 | nritems = btrfs_header_nritems(leaf); | |
3369 | data_end = leaf_data_end(root, leaf); | |
3370 | ||
3371 | if (btrfs_leaf_free_space(root, leaf) < total_size) { | |
3372 | for (i = nr; i >= 0; i--) { | |
3373 | total_data -= data_size[i]; | |
3374 | total_size -= data_size[i] + sizeof(struct btrfs_item); | |
3375 | if (total_size < btrfs_leaf_free_space(root, leaf)) | |
3376 | break; | |
3377 | } | |
3378 | nr = i; | |
3379 | } | |
3380 | ||
3381 | slot = path->slots[0]; | |
3382 | BUG_ON(slot < 0); | |
3383 | ||
3384 | if (slot != nritems) { | |
3385 | unsigned int old_data = btrfs_item_end_nr(leaf, slot); | |
3386 | ||
3387 | item = btrfs_item_nr(leaf, slot); | |
3388 | btrfs_item_key_to_cpu(leaf, &found_key, slot); | |
3389 | ||
3390 | /* figure out how many keys we can insert in here */ | |
3391 | total_data = data_size[0]; | |
3392 | for (i = 1; i < nr; i++) { | |
5d4f98a2 | 3393 | if (btrfs_comp_cpu_keys(&found_key, cpu_key + i) <= 0) |
f3465ca4 JB |
3394 | break; |
3395 | total_data += data_size[i]; | |
3396 | } | |
3397 | nr = i; | |
3398 | ||
3399 | if (old_data < data_end) { | |
3400 | btrfs_print_leaf(root, leaf); | |
d397712b | 3401 | printk(KERN_CRIT "slot %d old_data %d data_end %d\n", |
f3465ca4 JB |
3402 | slot, old_data, data_end); |
3403 | BUG_ON(1); | |
3404 | } | |
3405 | /* | |
3406 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
3407 | */ | |
3408 | /* first correct the data pointers */ | |
3409 | WARN_ON(leaf->map_token); | |
3410 | for (i = slot; i < nritems; i++) { | |
3411 | u32 ioff; | |
3412 | ||
3413 | item = btrfs_item_nr(leaf, i); | |
3414 | if (!leaf->map_token) { | |
3415 | map_extent_buffer(leaf, (unsigned long)item, | |
3416 | sizeof(struct btrfs_item), | |
3417 | &leaf->map_token, &leaf->kaddr, | |
3418 | &leaf->map_start, &leaf->map_len, | |
3419 | KM_USER1); | |
3420 | } | |
3421 | ||
3422 | ioff = btrfs_item_offset(leaf, item); | |
3423 | btrfs_set_item_offset(leaf, item, ioff - total_data); | |
3424 | } | |
3425 | if (leaf->map_token) { | |
3426 | unmap_extent_buffer(leaf, leaf->map_token, KM_USER1); | |
3427 | leaf->map_token = NULL; | |
3428 | } | |
3429 | ||
3430 | /* shift the items */ | |
3431 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr), | |
3432 | btrfs_item_nr_offset(slot), | |
3433 | (nritems - slot) * sizeof(struct btrfs_item)); | |
3434 | ||
3435 | /* shift the data */ | |
3436 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + | |
3437 | data_end - total_data, btrfs_leaf_data(leaf) + | |
3438 | data_end, old_data - data_end); | |
3439 | data_end = old_data; | |
3440 | } else { | |
3441 | /* | |
3442 | * this sucks but it has to be done, if we are inserting at | |
3443 | * the end of the leaf only insert 1 of the items, since we | |
3444 | * have no way of knowing whats on the next leaf and we'd have | |
3445 | * to drop our current locks to figure it out | |
3446 | */ | |
3447 | nr = 1; | |
3448 | } | |
3449 | ||
3450 | /* setup the item for the new data */ | |
3451 | for (i = 0; i < nr; i++) { | |
3452 | btrfs_cpu_key_to_disk(&disk_key, cpu_key + i); | |
3453 | btrfs_set_item_key(leaf, &disk_key, slot + i); | |
3454 | item = btrfs_item_nr(leaf, slot + i); | |
3455 | btrfs_set_item_offset(leaf, item, data_end - data_size[i]); | |
3456 | data_end -= data_size[i]; | |
3457 | btrfs_set_item_size(leaf, item, data_size[i]); | |
3458 | } | |
3459 | btrfs_set_header_nritems(leaf, nritems + nr); | |
3460 | btrfs_mark_buffer_dirty(leaf); | |
3461 | ||
3462 | ret = 0; | |
3463 | if (slot == 0) { | |
3464 | btrfs_cpu_key_to_disk(&disk_key, cpu_key); | |
3465 | ret = fixup_low_keys(trans, root, path, &disk_key, 1); | |
3466 | } | |
3467 | ||
3468 | if (btrfs_leaf_free_space(root, leaf) < 0) { | |
3469 | btrfs_print_leaf(root, leaf); | |
3470 | BUG(); | |
3471 | } | |
3472 | out: | |
3473 | if (!ret) | |
3474 | ret = nr; | |
3475 | return ret; | |
3476 | } | |
3477 | ||
74123bd7 | 3478 | /* |
44871b1b CM |
3479 | * this is a helper for btrfs_insert_empty_items, the main goal here is |
3480 | * to save stack depth by doing the bulk of the work in a function | |
3481 | * that doesn't call btrfs_search_slot | |
74123bd7 | 3482 | */ |
44871b1b CM |
3483 | static noinline_for_stack int |
3484 | setup_items_for_insert(struct btrfs_trans_handle *trans, | |
3485 | struct btrfs_root *root, struct btrfs_path *path, | |
3486 | struct btrfs_key *cpu_key, u32 *data_size, | |
3487 | u32 total_data, u32 total_size, int nr) | |
be0e5c09 | 3488 | { |
5f39d397 | 3489 | struct btrfs_item *item; |
9c58309d | 3490 | int i; |
7518a238 | 3491 | u32 nritems; |
be0e5c09 | 3492 | unsigned int data_end; |
e2fa7227 | 3493 | struct btrfs_disk_key disk_key; |
44871b1b CM |
3494 | int ret; |
3495 | struct extent_buffer *leaf; | |
3496 | int slot; | |
e2fa7227 | 3497 | |
5f39d397 | 3498 | leaf = path->nodes[0]; |
44871b1b | 3499 | slot = path->slots[0]; |
74123bd7 | 3500 | |
5f39d397 | 3501 | nritems = btrfs_header_nritems(leaf); |
123abc88 | 3502 | data_end = leaf_data_end(root, leaf); |
eb60ceac | 3503 | |
f25956cc | 3504 | if (btrfs_leaf_free_space(root, leaf) < total_size) { |
3326d1b0 | 3505 | btrfs_print_leaf(root, leaf); |
d397712b | 3506 | printk(KERN_CRIT "not enough freespace need %u have %d\n", |
9c58309d | 3507 | total_size, btrfs_leaf_free_space(root, leaf)); |
be0e5c09 | 3508 | BUG(); |
d4dbff95 | 3509 | } |
5f39d397 | 3510 | |
be0e5c09 | 3511 | if (slot != nritems) { |
5f39d397 | 3512 | unsigned int old_data = btrfs_item_end_nr(leaf, slot); |
be0e5c09 | 3513 | |
5f39d397 CM |
3514 | if (old_data < data_end) { |
3515 | btrfs_print_leaf(root, leaf); | |
d397712b | 3516 | printk(KERN_CRIT "slot %d old_data %d data_end %d\n", |
5f39d397 CM |
3517 | slot, old_data, data_end); |
3518 | BUG_ON(1); | |
3519 | } | |
be0e5c09 CM |
3520 | /* |
3521 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
3522 | */ | |
3523 | /* first correct the data pointers */ | |
db94535d | 3524 | WARN_ON(leaf->map_token); |
0783fcfc | 3525 | for (i = slot; i < nritems; i++) { |
5f39d397 | 3526 | u32 ioff; |
db94535d | 3527 | |
5f39d397 | 3528 | item = btrfs_item_nr(leaf, i); |
db94535d CM |
3529 | if (!leaf->map_token) { |
3530 | map_extent_buffer(leaf, (unsigned long)item, | |
3531 | sizeof(struct btrfs_item), | |
3532 | &leaf->map_token, &leaf->kaddr, | |
3533 | &leaf->map_start, &leaf->map_len, | |
3534 | KM_USER1); | |
3535 | } | |
3536 | ||
5f39d397 | 3537 | ioff = btrfs_item_offset(leaf, item); |
9c58309d | 3538 | btrfs_set_item_offset(leaf, item, ioff - total_data); |
0783fcfc | 3539 | } |
db94535d CM |
3540 | if (leaf->map_token) { |
3541 | unmap_extent_buffer(leaf, leaf->map_token, KM_USER1); | |
3542 | leaf->map_token = NULL; | |
3543 | } | |
be0e5c09 CM |
3544 | |
3545 | /* shift the items */ | |
9c58309d | 3546 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr), |
5f39d397 | 3547 | btrfs_item_nr_offset(slot), |
d6025579 | 3548 | (nritems - slot) * sizeof(struct btrfs_item)); |
be0e5c09 CM |
3549 | |
3550 | /* shift the data */ | |
5f39d397 | 3551 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + |
9c58309d | 3552 | data_end - total_data, btrfs_leaf_data(leaf) + |
d6025579 | 3553 | data_end, old_data - data_end); |
be0e5c09 CM |
3554 | data_end = old_data; |
3555 | } | |
5f39d397 | 3556 | |
62e2749e | 3557 | /* setup the item for the new data */ |
9c58309d CM |
3558 | for (i = 0; i < nr; i++) { |
3559 | btrfs_cpu_key_to_disk(&disk_key, cpu_key + i); | |
3560 | btrfs_set_item_key(leaf, &disk_key, slot + i); | |
3561 | item = btrfs_item_nr(leaf, slot + i); | |
3562 | btrfs_set_item_offset(leaf, item, data_end - data_size[i]); | |
3563 | data_end -= data_size[i]; | |
3564 | btrfs_set_item_size(leaf, item, data_size[i]); | |
3565 | } | |
44871b1b | 3566 | |
9c58309d | 3567 | btrfs_set_header_nritems(leaf, nritems + nr); |
aa5d6bed CM |
3568 | |
3569 | ret = 0; | |
5a01a2e3 | 3570 | if (slot == 0) { |
44871b1b | 3571 | struct btrfs_disk_key disk_key; |
5a01a2e3 | 3572 | btrfs_cpu_key_to_disk(&disk_key, cpu_key); |
e089f05c | 3573 | ret = fixup_low_keys(trans, root, path, &disk_key, 1); |
5a01a2e3 | 3574 | } |
b9473439 CM |
3575 | btrfs_unlock_up_safe(path, 1); |
3576 | btrfs_mark_buffer_dirty(leaf); | |
aa5d6bed | 3577 | |
5f39d397 CM |
3578 | if (btrfs_leaf_free_space(root, leaf) < 0) { |
3579 | btrfs_print_leaf(root, leaf); | |
be0e5c09 | 3580 | BUG(); |
5f39d397 | 3581 | } |
44871b1b CM |
3582 | return ret; |
3583 | } | |
3584 | ||
3585 | /* | |
3586 | * Given a key and some data, insert items into the tree. | |
3587 | * This does all the path init required, making room in the tree if needed. | |
3588 | */ | |
3589 | int btrfs_insert_empty_items(struct btrfs_trans_handle *trans, | |
3590 | struct btrfs_root *root, | |
3591 | struct btrfs_path *path, | |
3592 | struct btrfs_key *cpu_key, u32 *data_size, | |
3593 | int nr) | |
3594 | { | |
3595 | struct extent_buffer *leaf; | |
3596 | int ret = 0; | |
3597 | int slot; | |
3598 | int i; | |
3599 | u32 total_size = 0; | |
3600 | u32 total_data = 0; | |
3601 | ||
3602 | for (i = 0; i < nr; i++) | |
3603 | total_data += data_size[i]; | |
3604 | ||
3605 | total_size = total_data + (nr * sizeof(struct btrfs_item)); | |
3606 | ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1); | |
3607 | if (ret == 0) | |
3608 | return -EEXIST; | |
3609 | if (ret < 0) | |
3610 | goto out; | |
3611 | ||
3612 | leaf = path->nodes[0]; | |
3613 | slot = path->slots[0]; | |
3614 | BUG_ON(slot < 0); | |
3615 | ||
3616 | ret = setup_items_for_insert(trans, root, path, cpu_key, data_size, | |
3617 | total_data, total_size, nr); | |
3618 | ||
ed2ff2cb | 3619 | out: |
62e2749e CM |
3620 | return ret; |
3621 | } | |
3622 | ||
3623 | /* | |
3624 | * Given a key and some data, insert an item into the tree. | |
3625 | * This does all the path init required, making room in the tree if needed. | |
3626 | */ | |
e089f05c CM |
3627 | int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root |
3628 | *root, struct btrfs_key *cpu_key, void *data, u32 | |
3629 | data_size) | |
62e2749e CM |
3630 | { |
3631 | int ret = 0; | |
2c90e5d6 | 3632 | struct btrfs_path *path; |
5f39d397 CM |
3633 | struct extent_buffer *leaf; |
3634 | unsigned long ptr; | |
62e2749e | 3635 | |
2c90e5d6 CM |
3636 | path = btrfs_alloc_path(); |
3637 | BUG_ON(!path); | |
2c90e5d6 | 3638 | ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size); |
62e2749e | 3639 | if (!ret) { |
5f39d397 CM |
3640 | leaf = path->nodes[0]; |
3641 | ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); | |
3642 | write_extent_buffer(leaf, data, ptr, data_size); | |
3643 | btrfs_mark_buffer_dirty(leaf); | |
62e2749e | 3644 | } |
2c90e5d6 | 3645 | btrfs_free_path(path); |
aa5d6bed | 3646 | return ret; |
be0e5c09 CM |
3647 | } |
3648 | ||
74123bd7 | 3649 | /* |
5de08d7d | 3650 | * delete the pointer from a given node. |
74123bd7 | 3651 | * |
d352ac68 CM |
3652 | * the tree should have been previously balanced so the deletion does not |
3653 | * empty a node. | |
74123bd7 | 3654 | */ |
e089f05c CM |
3655 | static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
3656 | struct btrfs_path *path, int level, int slot) | |
be0e5c09 | 3657 | { |
5f39d397 | 3658 | struct extent_buffer *parent = path->nodes[level]; |
7518a238 | 3659 | u32 nritems; |
aa5d6bed | 3660 | int ret = 0; |
bb803951 | 3661 | int wret; |
be0e5c09 | 3662 | |
5f39d397 | 3663 | nritems = btrfs_header_nritems(parent); |
d397712b | 3664 | if (slot != nritems - 1) { |
5f39d397 CM |
3665 | memmove_extent_buffer(parent, |
3666 | btrfs_node_key_ptr_offset(slot), | |
3667 | btrfs_node_key_ptr_offset(slot + 1), | |
d6025579 CM |
3668 | sizeof(struct btrfs_key_ptr) * |
3669 | (nritems - slot - 1)); | |
bb803951 | 3670 | } |
7518a238 | 3671 | nritems--; |
5f39d397 | 3672 | btrfs_set_header_nritems(parent, nritems); |
7518a238 | 3673 | if (nritems == 0 && parent == root->node) { |
5f39d397 | 3674 | BUG_ON(btrfs_header_level(root->node) != 1); |
bb803951 | 3675 | /* just turn the root into a leaf and break */ |
5f39d397 | 3676 | btrfs_set_header_level(root->node, 0); |
bb803951 | 3677 | } else if (slot == 0) { |
5f39d397 CM |
3678 | struct btrfs_disk_key disk_key; |
3679 | ||
3680 | btrfs_node_key(parent, &disk_key, 0); | |
3681 | wret = fixup_low_keys(trans, root, path, &disk_key, level + 1); | |
0f70abe2 CM |
3682 | if (wret) |
3683 | ret = wret; | |
be0e5c09 | 3684 | } |
d6025579 | 3685 | btrfs_mark_buffer_dirty(parent); |
aa5d6bed | 3686 | return ret; |
be0e5c09 CM |
3687 | } |
3688 | ||
323ac95b CM |
3689 | /* |
3690 | * a helper function to delete the leaf pointed to by path->slots[1] and | |
5d4f98a2 | 3691 | * path->nodes[1]. |
323ac95b CM |
3692 | * |
3693 | * This deletes the pointer in path->nodes[1] and frees the leaf | |
3694 | * block extent. zero is returned if it all worked out, < 0 otherwise. | |
3695 | * | |
3696 | * The path must have already been setup for deleting the leaf, including | |
3697 | * all the proper balancing. path->nodes[1] must be locked. | |
3698 | */ | |
5d4f98a2 YZ |
3699 | static noinline int btrfs_del_leaf(struct btrfs_trans_handle *trans, |
3700 | struct btrfs_root *root, | |
3701 | struct btrfs_path *path, | |
3702 | struct extent_buffer *leaf) | |
323ac95b CM |
3703 | { |
3704 | int ret; | |
323ac95b | 3705 | |
5d4f98a2 | 3706 | WARN_ON(btrfs_header_generation(leaf) != trans->transid); |
323ac95b CM |
3707 | ret = del_ptr(trans, root, path, 1, path->slots[1]); |
3708 | if (ret) | |
3709 | return ret; | |
3710 | ||
4d081c41 CM |
3711 | /* |
3712 | * btrfs_free_extent is expensive, we want to make sure we | |
3713 | * aren't holding any locks when we call it | |
3714 | */ | |
3715 | btrfs_unlock_up_safe(path, 0); | |
3716 | ||
5d4f98a2 YZ |
3717 | ret = btrfs_free_extent(trans, root, leaf->start, leaf->len, |
3718 | 0, root->root_key.objectid, 0, 0); | |
323ac95b CM |
3719 | return ret; |
3720 | } | |
74123bd7 CM |
3721 | /* |
3722 | * delete the item at the leaf level in path. If that empties | |
3723 | * the leaf, remove it from the tree | |
3724 | */ | |
85e21bac CM |
3725 | int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
3726 | struct btrfs_path *path, int slot, int nr) | |
be0e5c09 | 3727 | { |
5f39d397 CM |
3728 | struct extent_buffer *leaf; |
3729 | struct btrfs_item *item; | |
85e21bac CM |
3730 | int last_off; |
3731 | int dsize = 0; | |
aa5d6bed CM |
3732 | int ret = 0; |
3733 | int wret; | |
85e21bac | 3734 | int i; |
7518a238 | 3735 | u32 nritems; |
be0e5c09 | 3736 | |
5f39d397 | 3737 | leaf = path->nodes[0]; |
85e21bac CM |
3738 | last_off = btrfs_item_offset_nr(leaf, slot + nr - 1); |
3739 | ||
3740 | for (i = 0; i < nr; i++) | |
3741 | dsize += btrfs_item_size_nr(leaf, slot + i); | |
3742 | ||
5f39d397 | 3743 | nritems = btrfs_header_nritems(leaf); |
be0e5c09 | 3744 | |
85e21bac | 3745 | if (slot + nr != nritems) { |
123abc88 | 3746 | int data_end = leaf_data_end(root, leaf); |
5f39d397 CM |
3747 | |
3748 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + | |
d6025579 CM |
3749 | data_end + dsize, |
3750 | btrfs_leaf_data(leaf) + data_end, | |
85e21bac | 3751 | last_off - data_end); |
5f39d397 | 3752 | |
85e21bac | 3753 | for (i = slot + nr; i < nritems; i++) { |
5f39d397 | 3754 | u32 ioff; |
db94535d | 3755 | |
5f39d397 | 3756 | item = btrfs_item_nr(leaf, i); |
db94535d CM |
3757 | if (!leaf->map_token) { |
3758 | map_extent_buffer(leaf, (unsigned long)item, | |
3759 | sizeof(struct btrfs_item), | |
3760 | &leaf->map_token, &leaf->kaddr, | |
3761 | &leaf->map_start, &leaf->map_len, | |
3762 | KM_USER1); | |
3763 | } | |
5f39d397 CM |
3764 | ioff = btrfs_item_offset(leaf, item); |
3765 | btrfs_set_item_offset(leaf, item, ioff + dsize); | |
0783fcfc | 3766 | } |
db94535d CM |
3767 | |
3768 | if (leaf->map_token) { | |
3769 | unmap_extent_buffer(leaf, leaf->map_token, KM_USER1); | |
3770 | leaf->map_token = NULL; | |
3771 | } | |
3772 | ||
5f39d397 | 3773 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot), |
85e21bac | 3774 | btrfs_item_nr_offset(slot + nr), |
d6025579 | 3775 | sizeof(struct btrfs_item) * |
85e21bac | 3776 | (nritems - slot - nr)); |
be0e5c09 | 3777 | } |
85e21bac CM |
3778 | btrfs_set_header_nritems(leaf, nritems - nr); |
3779 | nritems -= nr; | |
5f39d397 | 3780 | |
74123bd7 | 3781 | /* delete the leaf if we've emptied it */ |
7518a238 | 3782 | if (nritems == 0) { |
5f39d397 CM |
3783 | if (leaf == root->node) { |
3784 | btrfs_set_header_level(leaf, 0); | |
9a8dd150 | 3785 | } else { |
5d4f98a2 | 3786 | ret = btrfs_del_leaf(trans, root, path, leaf); |
323ac95b | 3787 | BUG_ON(ret); |
9a8dd150 | 3788 | } |
be0e5c09 | 3789 | } else { |
7518a238 | 3790 | int used = leaf_space_used(leaf, 0, nritems); |
aa5d6bed | 3791 | if (slot == 0) { |
5f39d397 CM |
3792 | struct btrfs_disk_key disk_key; |
3793 | ||
3794 | btrfs_item_key(leaf, &disk_key, 0); | |
e089f05c | 3795 | wret = fixup_low_keys(trans, root, path, |
5f39d397 | 3796 | &disk_key, 1); |
aa5d6bed CM |
3797 | if (wret) |
3798 | ret = wret; | |
3799 | } | |
aa5d6bed | 3800 | |
74123bd7 | 3801 | /* delete the leaf if it is mostly empty */ |
d717aa1d | 3802 | if (used < BTRFS_LEAF_DATA_SIZE(root) / 3) { |
be0e5c09 CM |
3803 | /* push_leaf_left fixes the path. |
3804 | * make sure the path still points to our leaf | |
3805 | * for possible call to del_ptr below | |
3806 | */ | |
4920c9ac | 3807 | slot = path->slots[1]; |
5f39d397 CM |
3808 | extent_buffer_get(leaf); |
3809 | ||
b9473439 | 3810 | btrfs_set_path_blocking(path); |
85e21bac | 3811 | wret = push_leaf_left(trans, root, path, 1, 1); |
54aa1f4d | 3812 | if (wret < 0 && wret != -ENOSPC) |
aa5d6bed | 3813 | ret = wret; |
5f39d397 CM |
3814 | |
3815 | if (path->nodes[0] == leaf && | |
3816 | btrfs_header_nritems(leaf)) { | |
85e21bac | 3817 | wret = push_leaf_right(trans, root, path, 1, 1); |
54aa1f4d | 3818 | if (wret < 0 && wret != -ENOSPC) |
aa5d6bed CM |
3819 | ret = wret; |
3820 | } | |
5f39d397 CM |
3821 | |
3822 | if (btrfs_header_nritems(leaf) == 0) { | |
323ac95b | 3823 | path->slots[1] = slot; |
5d4f98a2 | 3824 | ret = btrfs_del_leaf(trans, root, path, leaf); |
323ac95b | 3825 | BUG_ON(ret); |
5f39d397 | 3826 | free_extent_buffer(leaf); |
5de08d7d | 3827 | } else { |
925baedd CM |
3828 | /* if we're still in the path, make sure |
3829 | * we're dirty. Otherwise, one of the | |
3830 | * push_leaf functions must have already | |
3831 | * dirtied this buffer | |
3832 | */ | |
3833 | if (path->nodes[0] == leaf) | |
3834 | btrfs_mark_buffer_dirty(leaf); | |
5f39d397 | 3835 | free_extent_buffer(leaf); |
be0e5c09 | 3836 | } |
d5719762 | 3837 | } else { |
5f39d397 | 3838 | btrfs_mark_buffer_dirty(leaf); |
be0e5c09 CM |
3839 | } |
3840 | } | |
aa5d6bed | 3841 | return ret; |
be0e5c09 CM |
3842 | } |
3843 | ||
7bb86316 | 3844 | /* |
925baedd | 3845 | * search the tree again to find a leaf with lesser keys |
7bb86316 CM |
3846 | * returns 0 if it found something or 1 if there are no lesser leaves. |
3847 | * returns < 0 on io errors. | |
d352ac68 CM |
3848 | * |
3849 | * This may release the path, and so you may lose any locks held at the | |
3850 | * time you call it. | |
7bb86316 CM |
3851 | */ |
3852 | int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path) | |
3853 | { | |
925baedd CM |
3854 | struct btrfs_key key; |
3855 | struct btrfs_disk_key found_key; | |
3856 | int ret; | |
7bb86316 | 3857 | |
925baedd | 3858 | btrfs_item_key_to_cpu(path->nodes[0], &key, 0); |
7bb86316 | 3859 | |
925baedd CM |
3860 | if (key.offset > 0) |
3861 | key.offset--; | |
3862 | else if (key.type > 0) | |
3863 | key.type--; | |
3864 | else if (key.objectid > 0) | |
3865 | key.objectid--; | |
3866 | else | |
3867 | return 1; | |
7bb86316 | 3868 | |
925baedd CM |
3869 | btrfs_release_path(root, path); |
3870 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); | |
3871 | if (ret < 0) | |
3872 | return ret; | |
3873 | btrfs_item_key(path->nodes[0], &found_key, 0); | |
3874 | ret = comp_keys(&found_key, &key); | |
3875 | if (ret < 0) | |
3876 | return 0; | |
3877 | return 1; | |
7bb86316 CM |
3878 | } |
3879 | ||
3f157a2f CM |
3880 | /* |
3881 | * A helper function to walk down the tree starting at min_key, and looking | |
3882 | * for nodes or leaves that are either in cache or have a minimum | |
d352ac68 | 3883 | * transaction id. This is used by the btree defrag code, and tree logging |
3f157a2f CM |
3884 | * |
3885 | * This does not cow, but it does stuff the starting key it finds back | |
3886 | * into min_key, so you can call btrfs_search_slot with cow=1 on the | |
3887 | * key and get a writable path. | |
3888 | * | |
3889 | * This does lock as it descends, and path->keep_locks should be set | |
3890 | * to 1 by the caller. | |
3891 | * | |
3892 | * This honors path->lowest_level to prevent descent past a given level | |
3893 | * of the tree. | |
3894 | * | |
d352ac68 CM |
3895 | * min_trans indicates the oldest transaction that you are interested |
3896 | * in walking through. Any nodes or leaves older than min_trans are | |
3897 | * skipped over (without reading them). | |
3898 | * | |
3f157a2f CM |
3899 | * returns zero if something useful was found, < 0 on error and 1 if there |
3900 | * was nothing in the tree that matched the search criteria. | |
3901 | */ | |
3902 | int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key, | |
e02119d5 | 3903 | struct btrfs_key *max_key, |
3f157a2f CM |
3904 | struct btrfs_path *path, int cache_only, |
3905 | u64 min_trans) | |
3906 | { | |
3907 | struct extent_buffer *cur; | |
3908 | struct btrfs_key found_key; | |
3909 | int slot; | |
9652480b | 3910 | int sret; |
3f157a2f CM |
3911 | u32 nritems; |
3912 | int level; | |
3913 | int ret = 1; | |
3914 | ||
934d375b | 3915 | WARN_ON(!path->keep_locks); |
3f157a2f CM |
3916 | again: |
3917 | cur = btrfs_lock_root_node(root); | |
3918 | level = btrfs_header_level(cur); | |
e02119d5 | 3919 | WARN_ON(path->nodes[level]); |
3f157a2f CM |
3920 | path->nodes[level] = cur; |
3921 | path->locks[level] = 1; | |
3922 | ||
3923 | if (btrfs_header_generation(cur) < min_trans) { | |
3924 | ret = 1; | |
3925 | goto out; | |
3926 | } | |
d397712b | 3927 | while (1) { |
3f157a2f CM |
3928 | nritems = btrfs_header_nritems(cur); |
3929 | level = btrfs_header_level(cur); | |
9652480b | 3930 | sret = bin_search(cur, min_key, level, &slot); |
3f157a2f | 3931 | |
323ac95b CM |
3932 | /* at the lowest level, we're done, setup the path and exit */ |
3933 | if (level == path->lowest_level) { | |
e02119d5 CM |
3934 | if (slot >= nritems) |
3935 | goto find_next_key; | |
3f157a2f CM |
3936 | ret = 0; |
3937 | path->slots[level] = slot; | |
3938 | btrfs_item_key_to_cpu(cur, &found_key, slot); | |
3939 | goto out; | |
3940 | } | |
9652480b Y |
3941 | if (sret && slot > 0) |
3942 | slot--; | |
3f157a2f CM |
3943 | /* |
3944 | * check this node pointer against the cache_only and | |
3945 | * min_trans parameters. If it isn't in cache or is too | |
3946 | * old, skip to the next one. | |
3947 | */ | |
d397712b | 3948 | while (slot < nritems) { |
3f157a2f CM |
3949 | u64 blockptr; |
3950 | u64 gen; | |
3951 | struct extent_buffer *tmp; | |
e02119d5 CM |
3952 | struct btrfs_disk_key disk_key; |
3953 | ||
3f157a2f CM |
3954 | blockptr = btrfs_node_blockptr(cur, slot); |
3955 | gen = btrfs_node_ptr_generation(cur, slot); | |
3956 | if (gen < min_trans) { | |
3957 | slot++; | |
3958 | continue; | |
3959 | } | |
3960 | if (!cache_only) | |
3961 | break; | |
3962 | ||
e02119d5 CM |
3963 | if (max_key) { |
3964 | btrfs_node_key(cur, &disk_key, slot); | |
3965 | if (comp_keys(&disk_key, max_key) >= 0) { | |
3966 | ret = 1; | |
3967 | goto out; | |
3968 | } | |
3969 | } | |
3970 | ||
3f157a2f CM |
3971 | tmp = btrfs_find_tree_block(root, blockptr, |
3972 | btrfs_level_size(root, level - 1)); | |
3973 | ||
3974 | if (tmp && btrfs_buffer_uptodate(tmp, gen)) { | |
3975 | free_extent_buffer(tmp); | |
3976 | break; | |
3977 | } | |
3978 | if (tmp) | |
3979 | free_extent_buffer(tmp); | |
3980 | slot++; | |
3981 | } | |
e02119d5 | 3982 | find_next_key: |
3f157a2f CM |
3983 | /* |
3984 | * we didn't find a candidate key in this node, walk forward | |
3985 | * and find another one | |
3986 | */ | |
3987 | if (slot >= nritems) { | |
e02119d5 | 3988 | path->slots[level] = slot; |
b4ce94de | 3989 | btrfs_set_path_blocking(path); |
e02119d5 | 3990 | sret = btrfs_find_next_key(root, path, min_key, level, |
3f157a2f | 3991 | cache_only, min_trans); |
e02119d5 | 3992 | if (sret == 0) { |
3f157a2f CM |
3993 | btrfs_release_path(root, path); |
3994 | goto again; | |
3995 | } else { | |
3996 | goto out; | |
3997 | } | |
3998 | } | |
3999 | /* save our key for returning back */ | |
4000 | btrfs_node_key_to_cpu(cur, &found_key, slot); | |
4001 | path->slots[level] = slot; | |
4002 | if (level == path->lowest_level) { | |
4003 | ret = 0; | |
4004 | unlock_up(path, level, 1); | |
4005 | goto out; | |
4006 | } | |
b4ce94de | 4007 | btrfs_set_path_blocking(path); |
3f157a2f CM |
4008 | cur = read_node_slot(root, cur, slot); |
4009 | ||
4010 | btrfs_tree_lock(cur); | |
b4ce94de | 4011 | |
3f157a2f CM |
4012 | path->locks[level - 1] = 1; |
4013 | path->nodes[level - 1] = cur; | |
4014 | unlock_up(path, level, 1); | |
4008c04a | 4015 | btrfs_clear_path_blocking(path, NULL); |
3f157a2f CM |
4016 | } |
4017 | out: | |
4018 | if (ret == 0) | |
4019 | memcpy(min_key, &found_key, sizeof(found_key)); | |
b4ce94de | 4020 | btrfs_set_path_blocking(path); |
3f157a2f CM |
4021 | return ret; |
4022 | } | |
4023 | ||
4024 | /* | |
4025 | * this is similar to btrfs_next_leaf, but does not try to preserve | |
4026 | * and fixup the path. It looks for and returns the next key in the | |
4027 | * tree based on the current path and the cache_only and min_trans | |
4028 | * parameters. | |
4029 | * | |
4030 | * 0 is returned if another key is found, < 0 if there are any errors | |
4031 | * and 1 is returned if there are no higher keys in the tree | |
4032 | * | |
4033 | * path->keep_locks should be set to 1 on the search made before | |
4034 | * calling this function. | |
4035 | */ | |
e7a84565 | 4036 | int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path, |
33c66f43 | 4037 | struct btrfs_key *key, int level, |
3f157a2f | 4038 | int cache_only, u64 min_trans) |
e7a84565 | 4039 | { |
e7a84565 CM |
4040 | int slot; |
4041 | struct extent_buffer *c; | |
4042 | ||
934d375b | 4043 | WARN_ON(!path->keep_locks); |
d397712b | 4044 | while (level < BTRFS_MAX_LEVEL) { |
e7a84565 CM |
4045 | if (!path->nodes[level]) |
4046 | return 1; | |
4047 | ||
4048 | slot = path->slots[level] + 1; | |
4049 | c = path->nodes[level]; | |
3f157a2f | 4050 | next: |
e7a84565 | 4051 | if (slot >= btrfs_header_nritems(c)) { |
33c66f43 YZ |
4052 | int ret; |
4053 | int orig_lowest; | |
4054 | struct btrfs_key cur_key; | |
4055 | if (level + 1 >= BTRFS_MAX_LEVEL || | |
4056 | !path->nodes[level + 1]) | |
e7a84565 | 4057 | return 1; |
33c66f43 YZ |
4058 | |
4059 | if (path->locks[level + 1]) { | |
4060 | level++; | |
4061 | continue; | |
4062 | } | |
4063 | ||
4064 | slot = btrfs_header_nritems(c) - 1; | |
4065 | if (level == 0) | |
4066 | btrfs_item_key_to_cpu(c, &cur_key, slot); | |
4067 | else | |
4068 | btrfs_node_key_to_cpu(c, &cur_key, slot); | |
4069 | ||
4070 | orig_lowest = path->lowest_level; | |
4071 | btrfs_release_path(root, path); | |
4072 | path->lowest_level = level; | |
4073 | ret = btrfs_search_slot(NULL, root, &cur_key, path, | |
4074 | 0, 0); | |
4075 | path->lowest_level = orig_lowest; | |
4076 | if (ret < 0) | |
4077 | return ret; | |
4078 | ||
4079 | c = path->nodes[level]; | |
4080 | slot = path->slots[level]; | |
4081 | if (ret == 0) | |
4082 | slot++; | |
4083 | goto next; | |
e7a84565 | 4084 | } |
33c66f43 | 4085 | |
e7a84565 CM |
4086 | if (level == 0) |
4087 | btrfs_item_key_to_cpu(c, key, slot); | |
3f157a2f CM |
4088 | else { |
4089 | u64 blockptr = btrfs_node_blockptr(c, slot); | |
4090 | u64 gen = btrfs_node_ptr_generation(c, slot); | |
4091 | ||
4092 | if (cache_only) { | |
4093 | struct extent_buffer *cur; | |
4094 | cur = btrfs_find_tree_block(root, blockptr, | |
4095 | btrfs_level_size(root, level - 1)); | |
4096 | if (!cur || !btrfs_buffer_uptodate(cur, gen)) { | |
4097 | slot++; | |
4098 | if (cur) | |
4099 | free_extent_buffer(cur); | |
4100 | goto next; | |
4101 | } | |
4102 | free_extent_buffer(cur); | |
4103 | } | |
4104 | if (gen < min_trans) { | |
4105 | slot++; | |
4106 | goto next; | |
4107 | } | |
e7a84565 | 4108 | btrfs_node_key_to_cpu(c, key, slot); |
3f157a2f | 4109 | } |
e7a84565 CM |
4110 | return 0; |
4111 | } | |
4112 | return 1; | |
4113 | } | |
4114 | ||
97571fd0 | 4115 | /* |
925baedd | 4116 | * search the tree again to find a leaf with greater keys |
0f70abe2 CM |
4117 | * returns 0 if it found something or 1 if there are no greater leaves. |
4118 | * returns < 0 on io errors. | |
97571fd0 | 4119 | */ |
234b63a0 | 4120 | int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path) |
d97e63b6 CM |
4121 | { |
4122 | int slot; | |
8e73f275 | 4123 | int level; |
5f39d397 | 4124 | struct extent_buffer *c; |
8e73f275 | 4125 | struct extent_buffer *next; |
925baedd CM |
4126 | struct btrfs_key key; |
4127 | u32 nritems; | |
4128 | int ret; | |
8e73f275 CM |
4129 | int old_spinning = path->leave_spinning; |
4130 | int force_blocking = 0; | |
925baedd CM |
4131 | |
4132 | nritems = btrfs_header_nritems(path->nodes[0]); | |
d397712b | 4133 | if (nritems == 0) |
925baedd | 4134 | return 1; |
925baedd | 4135 | |
8e73f275 CM |
4136 | /* |
4137 | * we take the blocks in an order that upsets lockdep. Using | |
4138 | * blocking mode is the only way around it. | |
4139 | */ | |
4140 | #ifdef CONFIG_DEBUG_LOCK_ALLOC | |
4141 | force_blocking = 1; | |
4142 | #endif | |
925baedd | 4143 | |
8e73f275 CM |
4144 | btrfs_item_key_to_cpu(path->nodes[0], &key, nritems - 1); |
4145 | again: | |
4146 | level = 1; | |
4147 | next = NULL; | |
925baedd | 4148 | btrfs_release_path(root, path); |
8e73f275 | 4149 | |
a2135011 | 4150 | path->keep_locks = 1; |
8e73f275 CM |
4151 | |
4152 | if (!force_blocking) | |
4153 | path->leave_spinning = 1; | |
4154 | ||
925baedd CM |
4155 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
4156 | path->keep_locks = 0; | |
4157 | ||
4158 | if (ret < 0) | |
4159 | return ret; | |
4160 | ||
a2135011 | 4161 | nritems = btrfs_header_nritems(path->nodes[0]); |
168fd7d2 CM |
4162 | /* |
4163 | * by releasing the path above we dropped all our locks. A balance | |
4164 | * could have added more items next to the key that used to be | |
4165 | * at the very end of the block. So, check again here and | |
4166 | * advance the path if there are now more items available. | |
4167 | */ | |
a2135011 | 4168 | if (nritems > 0 && path->slots[0] < nritems - 1) { |
e457afec YZ |
4169 | if (ret == 0) |
4170 | path->slots[0]++; | |
8e73f275 | 4171 | ret = 0; |
925baedd CM |
4172 | goto done; |
4173 | } | |
d97e63b6 | 4174 | |
d397712b | 4175 | while (level < BTRFS_MAX_LEVEL) { |
8e73f275 CM |
4176 | if (!path->nodes[level]) { |
4177 | ret = 1; | |
4178 | goto done; | |
4179 | } | |
5f39d397 | 4180 | |
d97e63b6 CM |
4181 | slot = path->slots[level] + 1; |
4182 | c = path->nodes[level]; | |
5f39d397 | 4183 | if (slot >= btrfs_header_nritems(c)) { |
d97e63b6 | 4184 | level++; |
8e73f275 CM |
4185 | if (level == BTRFS_MAX_LEVEL) { |
4186 | ret = 1; | |
4187 | goto done; | |
4188 | } | |
d97e63b6 CM |
4189 | continue; |
4190 | } | |
5f39d397 | 4191 | |
925baedd CM |
4192 | if (next) { |
4193 | btrfs_tree_unlock(next); | |
5f39d397 | 4194 | free_extent_buffer(next); |
925baedd | 4195 | } |
5f39d397 | 4196 | |
8e73f275 CM |
4197 | next = c; |
4198 | ret = read_block_for_search(NULL, root, path, &next, level, | |
4199 | slot, &key); | |
4200 | if (ret == -EAGAIN) | |
4201 | goto again; | |
5f39d397 | 4202 | |
76a05b35 CM |
4203 | if (ret < 0) { |
4204 | btrfs_release_path(root, path); | |
4205 | goto done; | |
4206 | } | |
4207 | ||
5cd57b2c | 4208 | if (!path->skip_locking) { |
8e73f275 CM |
4209 | ret = btrfs_try_spin_lock(next); |
4210 | if (!ret) { | |
4211 | btrfs_set_path_blocking(path); | |
4212 | btrfs_tree_lock(next); | |
4213 | if (!force_blocking) | |
4214 | btrfs_clear_path_blocking(path, next); | |
4215 | } | |
4216 | if (force_blocking) | |
4217 | btrfs_set_lock_blocking(next); | |
5cd57b2c | 4218 | } |
d97e63b6 CM |
4219 | break; |
4220 | } | |
4221 | path->slots[level] = slot; | |
d397712b | 4222 | while (1) { |
d97e63b6 CM |
4223 | level--; |
4224 | c = path->nodes[level]; | |
925baedd CM |
4225 | if (path->locks[level]) |
4226 | btrfs_tree_unlock(c); | |
8e73f275 | 4227 | |
5f39d397 | 4228 | free_extent_buffer(c); |
d97e63b6 CM |
4229 | path->nodes[level] = next; |
4230 | path->slots[level] = 0; | |
a74a4b97 CM |
4231 | if (!path->skip_locking) |
4232 | path->locks[level] = 1; | |
8e73f275 | 4233 | |
d97e63b6 CM |
4234 | if (!level) |
4235 | break; | |
b4ce94de | 4236 | |
8e73f275 CM |
4237 | ret = read_block_for_search(NULL, root, path, &next, level, |
4238 | 0, &key); | |
4239 | if (ret == -EAGAIN) | |
4240 | goto again; | |
4241 | ||
76a05b35 CM |
4242 | if (ret < 0) { |
4243 | btrfs_release_path(root, path); | |
4244 | goto done; | |
4245 | } | |
4246 | ||
5cd57b2c | 4247 | if (!path->skip_locking) { |
b9447ef8 | 4248 | btrfs_assert_tree_locked(path->nodes[level]); |
8e73f275 CM |
4249 | ret = btrfs_try_spin_lock(next); |
4250 | if (!ret) { | |
4251 | btrfs_set_path_blocking(path); | |
4252 | btrfs_tree_lock(next); | |
4253 | if (!force_blocking) | |
4254 | btrfs_clear_path_blocking(path, next); | |
4255 | } | |
4256 | if (force_blocking) | |
4257 | btrfs_set_lock_blocking(next); | |
5cd57b2c | 4258 | } |
d97e63b6 | 4259 | } |
8e73f275 | 4260 | ret = 0; |
925baedd CM |
4261 | done: |
4262 | unlock_up(path, 0, 1); | |
8e73f275 CM |
4263 | path->leave_spinning = old_spinning; |
4264 | if (!old_spinning) | |
4265 | btrfs_set_path_blocking(path); | |
4266 | ||
4267 | return ret; | |
d97e63b6 | 4268 | } |
0b86a832 | 4269 | |
3f157a2f CM |
4270 | /* |
4271 | * this uses btrfs_prev_leaf to walk backwards in the tree, and keeps | |
4272 | * searching until it gets past min_objectid or finds an item of 'type' | |
4273 | * | |
4274 | * returns 0 if something is found, 1 if nothing was found and < 0 on error | |
4275 | */ | |
0b86a832 CM |
4276 | int btrfs_previous_item(struct btrfs_root *root, |
4277 | struct btrfs_path *path, u64 min_objectid, | |
4278 | int type) | |
4279 | { | |
4280 | struct btrfs_key found_key; | |
4281 | struct extent_buffer *leaf; | |
e02119d5 | 4282 | u32 nritems; |
0b86a832 CM |
4283 | int ret; |
4284 | ||
d397712b | 4285 | while (1) { |
0b86a832 | 4286 | if (path->slots[0] == 0) { |
b4ce94de | 4287 | btrfs_set_path_blocking(path); |
0b86a832 CM |
4288 | ret = btrfs_prev_leaf(root, path); |
4289 | if (ret != 0) | |
4290 | return ret; | |
4291 | } else { | |
4292 | path->slots[0]--; | |
4293 | } | |
4294 | leaf = path->nodes[0]; | |
e02119d5 CM |
4295 | nritems = btrfs_header_nritems(leaf); |
4296 | if (nritems == 0) | |
4297 | return 1; | |
4298 | if (path->slots[0] == nritems) | |
4299 | path->slots[0]--; | |
4300 | ||
0b86a832 | 4301 | btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); |
e02119d5 CM |
4302 | if (found_key.objectid < min_objectid) |
4303 | break; | |
0a4eefbb YZ |
4304 | if (found_key.type == type) |
4305 | return 0; | |
e02119d5 CM |
4306 | if (found_key.objectid == min_objectid && |
4307 | found_key.type < type) | |
4308 | break; | |
0b86a832 CM |
4309 | } |
4310 | return 1; | |
4311 | } |