]>
Commit | Line | Data |
---|---|---|
6cbd5570 | 1 | /* |
d352ac68 | 2 | * Copyright (C) 2007,2008 Oracle. All rights reserved. |
6cbd5570 CM |
3 | * |
4 | * This program is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU General Public | |
6 | * License v2 as published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, | |
9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
11 | * General Public License for more details. | |
12 | * | |
13 | * You should have received a copy of the GNU General Public | |
14 | * License along with this program; if not, write to the | |
15 | * Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
16 | * Boston, MA 021110-1307, USA. | |
17 | */ | |
18 | ||
a6b6e75e | 19 | #include <linux/sched.h> |
5a0e3ad6 | 20 | #include <linux/slab.h> |
eb60ceac CM |
21 | #include "ctree.h" |
22 | #include "disk-io.h" | |
7f5c1516 | 23 | #include "transaction.h" |
5f39d397 | 24 | #include "print-tree.h" |
925baedd | 25 | #include "locking.h" |
9a8dd150 | 26 | |
e089f05c CM |
27 | static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root |
28 | *root, struct btrfs_path *path, int level); | |
29 | static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root | |
d4dbff95 | 30 | *root, struct btrfs_key *ins_key, |
cc0c5538 | 31 | struct btrfs_path *path, int data_size, int extend); |
5f39d397 CM |
32 | static int push_node_left(struct btrfs_trans_handle *trans, |
33 | struct btrfs_root *root, struct extent_buffer *dst, | |
971a1f66 | 34 | struct extent_buffer *src, int empty); |
5f39d397 CM |
35 | static int balance_node_right(struct btrfs_trans_handle *trans, |
36 | struct btrfs_root *root, | |
37 | struct extent_buffer *dst_buf, | |
38 | struct extent_buffer *src_buf); | |
e089f05c CM |
39 | static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
40 | struct btrfs_path *path, int level, int slot); | |
d97e63b6 | 41 | |
df24a2b9 | 42 | struct btrfs_path *btrfs_alloc_path(void) |
2c90e5d6 | 43 | { |
df24a2b9 | 44 | struct btrfs_path *path; |
e00f7308 | 45 | path = kmem_cache_zalloc(btrfs_path_cachep, GFP_NOFS); |
df24a2b9 | 46 | return path; |
2c90e5d6 CM |
47 | } |
48 | ||
b4ce94de CM |
49 | /* |
50 | * set all locked nodes in the path to blocking locks. This should | |
51 | * be done before scheduling | |
52 | */ | |
53 | noinline void btrfs_set_path_blocking(struct btrfs_path *p) | |
54 | { | |
55 | int i; | |
56 | for (i = 0; i < BTRFS_MAX_LEVEL; i++) { | |
bd681513 CM |
57 | if (!p->nodes[i] || !p->locks[i]) |
58 | continue; | |
59 | btrfs_set_lock_blocking_rw(p->nodes[i], p->locks[i]); | |
60 | if (p->locks[i] == BTRFS_READ_LOCK) | |
61 | p->locks[i] = BTRFS_READ_LOCK_BLOCKING; | |
62 | else if (p->locks[i] == BTRFS_WRITE_LOCK) | |
63 | p->locks[i] = BTRFS_WRITE_LOCK_BLOCKING; | |
b4ce94de CM |
64 | } |
65 | } | |
66 | ||
67 | /* | |
68 | * reset all the locked nodes in the patch to spinning locks. | |
4008c04a CM |
69 | * |
70 | * held is used to keep lockdep happy, when lockdep is enabled | |
71 | * we set held to a blocking lock before we go around and | |
72 | * retake all the spinlocks in the path. You can safely use NULL | |
73 | * for held | |
b4ce94de | 74 | */ |
4008c04a | 75 | noinline void btrfs_clear_path_blocking(struct btrfs_path *p, |
bd681513 | 76 | struct extent_buffer *held, int held_rw) |
b4ce94de CM |
77 | { |
78 | int i; | |
4008c04a CM |
79 | |
80 | #ifdef CONFIG_DEBUG_LOCK_ALLOC | |
81 | /* lockdep really cares that we take all of these spinlocks | |
82 | * in the right order. If any of the locks in the path are not | |
83 | * currently blocking, it is going to complain. So, make really | |
84 | * really sure by forcing the path to blocking before we clear | |
85 | * the path blocking. | |
86 | */ | |
bd681513 CM |
87 | if (held) { |
88 | btrfs_set_lock_blocking_rw(held, held_rw); | |
89 | if (held_rw == BTRFS_WRITE_LOCK) | |
90 | held_rw = BTRFS_WRITE_LOCK_BLOCKING; | |
91 | else if (held_rw == BTRFS_READ_LOCK) | |
92 | held_rw = BTRFS_READ_LOCK_BLOCKING; | |
93 | } | |
4008c04a CM |
94 | btrfs_set_path_blocking(p); |
95 | #endif | |
96 | ||
97 | for (i = BTRFS_MAX_LEVEL - 1; i >= 0; i--) { | |
bd681513 CM |
98 | if (p->nodes[i] && p->locks[i]) { |
99 | btrfs_clear_lock_blocking_rw(p->nodes[i], p->locks[i]); | |
100 | if (p->locks[i] == BTRFS_WRITE_LOCK_BLOCKING) | |
101 | p->locks[i] = BTRFS_WRITE_LOCK; | |
102 | else if (p->locks[i] == BTRFS_READ_LOCK_BLOCKING) | |
103 | p->locks[i] = BTRFS_READ_LOCK; | |
104 | } | |
b4ce94de | 105 | } |
4008c04a CM |
106 | |
107 | #ifdef CONFIG_DEBUG_LOCK_ALLOC | |
108 | if (held) | |
bd681513 | 109 | btrfs_clear_lock_blocking_rw(held, held_rw); |
4008c04a | 110 | #endif |
b4ce94de CM |
111 | } |
112 | ||
d352ac68 | 113 | /* this also releases the path */ |
df24a2b9 | 114 | void btrfs_free_path(struct btrfs_path *p) |
be0e5c09 | 115 | { |
ff175d57 JJ |
116 | if (!p) |
117 | return; | |
b3b4aa74 | 118 | btrfs_release_path(p); |
df24a2b9 | 119 | kmem_cache_free(btrfs_path_cachep, p); |
be0e5c09 CM |
120 | } |
121 | ||
d352ac68 CM |
122 | /* |
123 | * path release drops references on the extent buffers in the path | |
124 | * and it drops any locks held by this path | |
125 | * | |
126 | * It is safe to call this on paths that no locks or extent buffers held. | |
127 | */ | |
b3b4aa74 | 128 | noinline void btrfs_release_path(struct btrfs_path *p) |
eb60ceac CM |
129 | { |
130 | int i; | |
a2135011 | 131 | |
234b63a0 | 132 | for (i = 0; i < BTRFS_MAX_LEVEL; i++) { |
3f157a2f | 133 | p->slots[i] = 0; |
eb60ceac | 134 | if (!p->nodes[i]) |
925baedd CM |
135 | continue; |
136 | if (p->locks[i]) { | |
bd681513 | 137 | btrfs_tree_unlock_rw(p->nodes[i], p->locks[i]); |
925baedd CM |
138 | p->locks[i] = 0; |
139 | } | |
5f39d397 | 140 | free_extent_buffer(p->nodes[i]); |
3f157a2f | 141 | p->nodes[i] = NULL; |
eb60ceac CM |
142 | } |
143 | } | |
144 | ||
d352ac68 CM |
145 | /* |
146 | * safely gets a reference on the root node of a tree. A lock | |
147 | * is not taken, so a concurrent writer may put a different node | |
148 | * at the root of the tree. See btrfs_lock_root_node for the | |
149 | * looping required. | |
150 | * | |
151 | * The extent buffer returned by this has a reference taken, so | |
152 | * it won't disappear. It may stop being the root of the tree | |
153 | * at any time because there are no locks held. | |
154 | */ | |
925baedd CM |
155 | struct extent_buffer *btrfs_root_node(struct btrfs_root *root) |
156 | { | |
157 | struct extent_buffer *eb; | |
240f62c8 CM |
158 | |
159 | rcu_read_lock(); | |
160 | eb = rcu_dereference(root->node); | |
925baedd | 161 | extent_buffer_get(eb); |
240f62c8 | 162 | rcu_read_unlock(); |
925baedd CM |
163 | return eb; |
164 | } | |
165 | ||
d352ac68 CM |
166 | /* loop around taking references on and locking the root node of the |
167 | * tree until you end up with a lock on the root. A locked buffer | |
168 | * is returned, with a reference held. | |
169 | */ | |
925baedd CM |
170 | struct extent_buffer *btrfs_lock_root_node(struct btrfs_root *root) |
171 | { | |
172 | struct extent_buffer *eb; | |
173 | ||
d397712b | 174 | while (1) { |
925baedd CM |
175 | eb = btrfs_root_node(root); |
176 | btrfs_tree_lock(eb); | |
240f62c8 | 177 | if (eb == root->node) |
925baedd | 178 | break; |
925baedd CM |
179 | btrfs_tree_unlock(eb); |
180 | free_extent_buffer(eb); | |
181 | } | |
182 | return eb; | |
183 | } | |
184 | ||
bd681513 CM |
185 | /* loop around taking references on and locking the root node of the |
186 | * tree until you end up with a lock on the root. A locked buffer | |
187 | * is returned, with a reference held. | |
188 | */ | |
189 | struct extent_buffer *btrfs_read_lock_root_node(struct btrfs_root *root) | |
190 | { | |
191 | struct extent_buffer *eb; | |
192 | ||
193 | while (1) { | |
194 | eb = btrfs_root_node(root); | |
195 | btrfs_tree_read_lock(eb); | |
196 | if (eb == root->node) | |
197 | break; | |
198 | btrfs_tree_read_unlock(eb); | |
199 | free_extent_buffer(eb); | |
200 | } | |
201 | return eb; | |
202 | } | |
203 | ||
d352ac68 CM |
204 | /* cowonly root (everything not a reference counted cow subvolume), just get |
205 | * put onto a simple dirty list. transaction.c walks this to make sure they | |
206 | * get properly updated on disk. | |
207 | */ | |
0b86a832 CM |
208 | static void add_root_to_dirty_list(struct btrfs_root *root) |
209 | { | |
210 | if (root->track_dirty && list_empty(&root->dirty_list)) { | |
211 | list_add(&root->dirty_list, | |
212 | &root->fs_info->dirty_cowonly_roots); | |
213 | } | |
214 | } | |
215 | ||
d352ac68 CM |
216 | /* |
217 | * used by snapshot creation to make a copy of a root for a tree with | |
218 | * a given objectid. The buffer with the new root node is returned in | |
219 | * cow_ret, and this func returns zero on success or a negative error code. | |
220 | */ | |
be20aa9d CM |
221 | int btrfs_copy_root(struct btrfs_trans_handle *trans, |
222 | struct btrfs_root *root, | |
223 | struct extent_buffer *buf, | |
224 | struct extent_buffer **cow_ret, u64 new_root_objectid) | |
225 | { | |
226 | struct extent_buffer *cow; | |
be20aa9d CM |
227 | int ret = 0; |
228 | int level; | |
5d4f98a2 | 229 | struct btrfs_disk_key disk_key; |
be20aa9d CM |
230 | |
231 | WARN_ON(root->ref_cows && trans->transid != | |
232 | root->fs_info->running_transaction->transid); | |
233 | WARN_ON(root->ref_cows && trans->transid != root->last_trans); | |
234 | ||
235 | level = btrfs_header_level(buf); | |
5d4f98a2 YZ |
236 | if (level == 0) |
237 | btrfs_item_key(buf, &disk_key, 0); | |
238 | else | |
239 | btrfs_node_key(buf, &disk_key, 0); | |
31840ae1 | 240 | |
5d4f98a2 YZ |
241 | cow = btrfs_alloc_free_block(trans, root, buf->len, 0, |
242 | new_root_objectid, &disk_key, level, | |
243 | buf->start, 0); | |
244 | if (IS_ERR(cow)) | |
be20aa9d CM |
245 | return PTR_ERR(cow); |
246 | ||
247 | copy_extent_buffer(cow, buf, 0, 0, cow->len); | |
248 | btrfs_set_header_bytenr(cow, cow->start); | |
249 | btrfs_set_header_generation(cow, trans->transid); | |
5d4f98a2 YZ |
250 | btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV); |
251 | btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN | | |
252 | BTRFS_HEADER_FLAG_RELOC); | |
253 | if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID) | |
254 | btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC); | |
255 | else | |
256 | btrfs_set_header_owner(cow, new_root_objectid); | |
be20aa9d | 257 | |
2b82032c YZ |
258 | write_extent_buffer(cow, root->fs_info->fsid, |
259 | (unsigned long)btrfs_header_fsid(cow), | |
260 | BTRFS_FSID_SIZE); | |
261 | ||
be20aa9d | 262 | WARN_ON(btrfs_header_generation(buf) > trans->transid); |
5d4f98a2 YZ |
263 | if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID) |
264 | ret = btrfs_inc_ref(trans, root, cow, 1); | |
265 | else | |
266 | ret = btrfs_inc_ref(trans, root, cow, 0); | |
4aec2b52 | 267 | |
be20aa9d CM |
268 | if (ret) |
269 | return ret; | |
270 | ||
271 | btrfs_mark_buffer_dirty(cow); | |
272 | *cow_ret = cow; | |
273 | return 0; | |
274 | } | |
275 | ||
5d4f98a2 YZ |
276 | /* |
277 | * check if the tree block can be shared by multiple trees | |
278 | */ | |
279 | int btrfs_block_can_be_shared(struct btrfs_root *root, | |
280 | struct extent_buffer *buf) | |
281 | { | |
282 | /* | |
283 | * Tree blocks not in refernece counted trees and tree roots | |
284 | * are never shared. If a block was allocated after the last | |
285 | * snapshot and the block was not allocated by tree relocation, | |
286 | * we know the block is not shared. | |
287 | */ | |
288 | if (root->ref_cows && | |
289 | buf != root->node && buf != root->commit_root && | |
290 | (btrfs_header_generation(buf) <= | |
291 | btrfs_root_last_snapshot(&root->root_item) || | |
292 | btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC))) | |
293 | return 1; | |
294 | #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 | |
295 | if (root->ref_cows && | |
296 | btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) | |
297 | return 1; | |
298 | #endif | |
299 | return 0; | |
300 | } | |
301 | ||
302 | static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans, | |
303 | struct btrfs_root *root, | |
304 | struct extent_buffer *buf, | |
f0486c68 YZ |
305 | struct extent_buffer *cow, |
306 | int *last_ref) | |
5d4f98a2 YZ |
307 | { |
308 | u64 refs; | |
309 | u64 owner; | |
310 | u64 flags; | |
311 | u64 new_flags = 0; | |
312 | int ret; | |
313 | ||
314 | /* | |
315 | * Backrefs update rules: | |
316 | * | |
317 | * Always use full backrefs for extent pointers in tree block | |
318 | * allocated by tree relocation. | |
319 | * | |
320 | * If a shared tree block is no longer referenced by its owner | |
321 | * tree (btrfs_header_owner(buf) == root->root_key.objectid), | |
322 | * use full backrefs for extent pointers in tree block. | |
323 | * | |
324 | * If a tree block is been relocating | |
325 | * (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID), | |
326 | * use full backrefs for extent pointers in tree block. | |
327 | * The reason for this is some operations (such as drop tree) | |
328 | * are only allowed for blocks use full backrefs. | |
329 | */ | |
330 | ||
331 | if (btrfs_block_can_be_shared(root, buf)) { | |
332 | ret = btrfs_lookup_extent_info(trans, root, buf->start, | |
333 | buf->len, &refs, &flags); | |
334 | BUG_ON(ret); | |
335 | BUG_ON(refs == 0); | |
336 | } else { | |
337 | refs = 1; | |
338 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID || | |
339 | btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) | |
340 | flags = BTRFS_BLOCK_FLAG_FULL_BACKREF; | |
341 | else | |
342 | flags = 0; | |
343 | } | |
344 | ||
345 | owner = btrfs_header_owner(buf); | |
346 | BUG_ON(owner == BTRFS_TREE_RELOC_OBJECTID && | |
347 | !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)); | |
348 | ||
349 | if (refs > 1) { | |
350 | if ((owner == root->root_key.objectid || | |
351 | root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) && | |
352 | !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)) { | |
353 | ret = btrfs_inc_ref(trans, root, buf, 1); | |
354 | BUG_ON(ret); | |
355 | ||
356 | if (root->root_key.objectid == | |
357 | BTRFS_TREE_RELOC_OBJECTID) { | |
358 | ret = btrfs_dec_ref(trans, root, buf, 0); | |
359 | BUG_ON(ret); | |
360 | ret = btrfs_inc_ref(trans, root, cow, 1); | |
361 | BUG_ON(ret); | |
362 | } | |
363 | new_flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF; | |
364 | } else { | |
365 | ||
366 | if (root->root_key.objectid == | |
367 | BTRFS_TREE_RELOC_OBJECTID) | |
368 | ret = btrfs_inc_ref(trans, root, cow, 1); | |
369 | else | |
370 | ret = btrfs_inc_ref(trans, root, cow, 0); | |
371 | BUG_ON(ret); | |
372 | } | |
373 | if (new_flags != 0) { | |
374 | ret = btrfs_set_disk_extent_flags(trans, root, | |
375 | buf->start, | |
376 | buf->len, | |
377 | new_flags, 0); | |
378 | BUG_ON(ret); | |
379 | } | |
380 | } else { | |
381 | if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF) { | |
382 | if (root->root_key.objectid == | |
383 | BTRFS_TREE_RELOC_OBJECTID) | |
384 | ret = btrfs_inc_ref(trans, root, cow, 1); | |
385 | else | |
386 | ret = btrfs_inc_ref(trans, root, cow, 0); | |
387 | BUG_ON(ret); | |
388 | ret = btrfs_dec_ref(trans, root, buf, 1); | |
389 | BUG_ON(ret); | |
390 | } | |
391 | clean_tree_block(trans, root, buf); | |
f0486c68 | 392 | *last_ref = 1; |
5d4f98a2 YZ |
393 | } |
394 | return 0; | |
395 | } | |
396 | ||
d352ac68 | 397 | /* |
d397712b CM |
398 | * does the dirty work in cow of a single block. The parent block (if |
399 | * supplied) is updated to point to the new cow copy. The new buffer is marked | |
400 | * dirty and returned locked. If you modify the block it needs to be marked | |
401 | * dirty again. | |
d352ac68 CM |
402 | * |
403 | * search_start -- an allocation hint for the new block | |
404 | * | |
d397712b CM |
405 | * empty_size -- a hint that you plan on doing more cow. This is the size in |
406 | * bytes the allocator should try to find free next to the block it returns. | |
407 | * This is just a hint and may be ignored by the allocator. | |
d352ac68 | 408 | */ |
d397712b | 409 | static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans, |
5f39d397 CM |
410 | struct btrfs_root *root, |
411 | struct extent_buffer *buf, | |
412 | struct extent_buffer *parent, int parent_slot, | |
413 | struct extent_buffer **cow_ret, | |
9fa8cfe7 | 414 | u64 search_start, u64 empty_size) |
02217ed2 | 415 | { |
5d4f98a2 | 416 | struct btrfs_disk_key disk_key; |
5f39d397 | 417 | struct extent_buffer *cow; |
7bb86316 | 418 | int level; |
f0486c68 | 419 | int last_ref = 0; |
925baedd | 420 | int unlock_orig = 0; |
5d4f98a2 | 421 | u64 parent_start; |
7bb86316 | 422 | |
925baedd CM |
423 | if (*cow_ret == buf) |
424 | unlock_orig = 1; | |
425 | ||
b9447ef8 | 426 | btrfs_assert_tree_locked(buf); |
925baedd | 427 | |
7bb86316 CM |
428 | WARN_ON(root->ref_cows && trans->transid != |
429 | root->fs_info->running_transaction->transid); | |
6702ed49 | 430 | WARN_ON(root->ref_cows && trans->transid != root->last_trans); |
5f39d397 | 431 | |
7bb86316 | 432 | level = btrfs_header_level(buf); |
31840ae1 | 433 | |
5d4f98a2 YZ |
434 | if (level == 0) |
435 | btrfs_item_key(buf, &disk_key, 0); | |
436 | else | |
437 | btrfs_node_key(buf, &disk_key, 0); | |
438 | ||
439 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) { | |
440 | if (parent) | |
441 | parent_start = parent->start; | |
442 | else | |
443 | parent_start = 0; | |
444 | } else | |
445 | parent_start = 0; | |
446 | ||
447 | cow = btrfs_alloc_free_block(trans, root, buf->len, parent_start, | |
448 | root->root_key.objectid, &disk_key, | |
449 | level, search_start, empty_size); | |
54aa1f4d CM |
450 | if (IS_ERR(cow)) |
451 | return PTR_ERR(cow); | |
6702ed49 | 452 | |
b4ce94de CM |
453 | /* cow is set to blocking by btrfs_init_new_buffer */ |
454 | ||
5f39d397 | 455 | copy_extent_buffer(cow, buf, 0, 0, cow->len); |
db94535d | 456 | btrfs_set_header_bytenr(cow, cow->start); |
5f39d397 | 457 | btrfs_set_header_generation(cow, trans->transid); |
5d4f98a2 YZ |
458 | btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV); |
459 | btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN | | |
460 | BTRFS_HEADER_FLAG_RELOC); | |
461 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) | |
462 | btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC); | |
463 | else | |
464 | btrfs_set_header_owner(cow, root->root_key.objectid); | |
6702ed49 | 465 | |
2b82032c YZ |
466 | write_extent_buffer(cow, root->fs_info->fsid, |
467 | (unsigned long)btrfs_header_fsid(cow), | |
468 | BTRFS_FSID_SIZE); | |
469 | ||
f0486c68 | 470 | update_ref_for_cow(trans, root, buf, cow, &last_ref); |
1a40e23b | 471 | |
3fd0a558 YZ |
472 | if (root->ref_cows) |
473 | btrfs_reloc_cow_block(trans, root, buf, cow); | |
474 | ||
02217ed2 | 475 | if (buf == root->node) { |
925baedd | 476 | WARN_ON(parent && parent != buf); |
5d4f98a2 YZ |
477 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID || |
478 | btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) | |
479 | parent_start = buf->start; | |
480 | else | |
481 | parent_start = 0; | |
925baedd | 482 | |
5f39d397 | 483 | extent_buffer_get(cow); |
240f62c8 | 484 | rcu_assign_pointer(root->node, cow); |
925baedd | 485 | |
f0486c68 YZ |
486 | btrfs_free_tree_block(trans, root, buf, parent_start, |
487 | last_ref); | |
5f39d397 | 488 | free_extent_buffer(buf); |
0b86a832 | 489 | add_root_to_dirty_list(root); |
02217ed2 | 490 | } else { |
5d4f98a2 YZ |
491 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) |
492 | parent_start = parent->start; | |
493 | else | |
494 | parent_start = 0; | |
495 | ||
496 | WARN_ON(trans->transid != btrfs_header_generation(parent)); | |
5f39d397 | 497 | btrfs_set_node_blockptr(parent, parent_slot, |
db94535d | 498 | cow->start); |
74493f7a CM |
499 | btrfs_set_node_ptr_generation(parent, parent_slot, |
500 | trans->transid); | |
d6025579 | 501 | btrfs_mark_buffer_dirty(parent); |
f0486c68 YZ |
502 | btrfs_free_tree_block(trans, root, buf, parent_start, |
503 | last_ref); | |
02217ed2 | 504 | } |
925baedd CM |
505 | if (unlock_orig) |
506 | btrfs_tree_unlock(buf); | |
5f39d397 | 507 | free_extent_buffer(buf); |
ccd467d6 | 508 | btrfs_mark_buffer_dirty(cow); |
2c90e5d6 | 509 | *cow_ret = cow; |
02217ed2 CM |
510 | return 0; |
511 | } | |
512 | ||
5d4f98a2 YZ |
513 | static inline int should_cow_block(struct btrfs_trans_handle *trans, |
514 | struct btrfs_root *root, | |
515 | struct extent_buffer *buf) | |
516 | { | |
517 | if (btrfs_header_generation(buf) == trans->transid && | |
518 | !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN) && | |
519 | !(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID && | |
520 | btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC))) | |
521 | return 0; | |
522 | return 1; | |
523 | } | |
524 | ||
d352ac68 CM |
525 | /* |
526 | * cows a single block, see __btrfs_cow_block for the real work. | |
527 | * This version of it has extra checks so that a block isn't cow'd more than | |
528 | * once per transaction, as long as it hasn't been written yet | |
529 | */ | |
d397712b | 530 | noinline int btrfs_cow_block(struct btrfs_trans_handle *trans, |
5f39d397 CM |
531 | struct btrfs_root *root, struct extent_buffer *buf, |
532 | struct extent_buffer *parent, int parent_slot, | |
9fa8cfe7 | 533 | struct extent_buffer **cow_ret) |
6702ed49 CM |
534 | { |
535 | u64 search_start; | |
f510cfec | 536 | int ret; |
dc17ff8f | 537 | |
6702ed49 | 538 | if (trans->transaction != root->fs_info->running_transaction) { |
d397712b CM |
539 | printk(KERN_CRIT "trans %llu running %llu\n", |
540 | (unsigned long long)trans->transid, | |
541 | (unsigned long long) | |
6702ed49 CM |
542 | root->fs_info->running_transaction->transid); |
543 | WARN_ON(1); | |
544 | } | |
545 | if (trans->transid != root->fs_info->generation) { | |
d397712b CM |
546 | printk(KERN_CRIT "trans %llu running %llu\n", |
547 | (unsigned long long)trans->transid, | |
548 | (unsigned long long)root->fs_info->generation); | |
6702ed49 CM |
549 | WARN_ON(1); |
550 | } | |
dc17ff8f | 551 | |
5d4f98a2 | 552 | if (!should_cow_block(trans, root, buf)) { |
6702ed49 CM |
553 | *cow_ret = buf; |
554 | return 0; | |
555 | } | |
c487685d | 556 | |
0b86a832 | 557 | search_start = buf->start & ~((u64)(1024 * 1024 * 1024) - 1); |
b4ce94de CM |
558 | |
559 | if (parent) | |
560 | btrfs_set_lock_blocking(parent); | |
561 | btrfs_set_lock_blocking(buf); | |
562 | ||
f510cfec | 563 | ret = __btrfs_cow_block(trans, root, buf, parent, |
9fa8cfe7 | 564 | parent_slot, cow_ret, search_start, 0); |
1abe9b8a | 565 | |
566 | trace_btrfs_cow_block(root, buf, *cow_ret); | |
567 | ||
f510cfec | 568 | return ret; |
6702ed49 CM |
569 | } |
570 | ||
d352ac68 CM |
571 | /* |
572 | * helper function for defrag to decide if two blocks pointed to by a | |
573 | * node are actually close by | |
574 | */ | |
6b80053d | 575 | static int close_blocks(u64 blocknr, u64 other, u32 blocksize) |
6702ed49 | 576 | { |
6b80053d | 577 | if (blocknr < other && other - (blocknr + blocksize) < 32768) |
6702ed49 | 578 | return 1; |
6b80053d | 579 | if (blocknr > other && blocknr - (other + blocksize) < 32768) |
6702ed49 CM |
580 | return 1; |
581 | return 0; | |
582 | } | |
583 | ||
081e9573 CM |
584 | /* |
585 | * compare two keys in a memcmp fashion | |
586 | */ | |
587 | static int comp_keys(struct btrfs_disk_key *disk, struct btrfs_key *k2) | |
588 | { | |
589 | struct btrfs_key k1; | |
590 | ||
591 | btrfs_disk_key_to_cpu(&k1, disk); | |
592 | ||
20736aba | 593 | return btrfs_comp_cpu_keys(&k1, k2); |
081e9573 CM |
594 | } |
595 | ||
f3465ca4 JB |
596 | /* |
597 | * same as comp_keys only with two btrfs_key's | |
598 | */ | |
5d4f98a2 | 599 | int btrfs_comp_cpu_keys(struct btrfs_key *k1, struct btrfs_key *k2) |
f3465ca4 JB |
600 | { |
601 | if (k1->objectid > k2->objectid) | |
602 | return 1; | |
603 | if (k1->objectid < k2->objectid) | |
604 | return -1; | |
605 | if (k1->type > k2->type) | |
606 | return 1; | |
607 | if (k1->type < k2->type) | |
608 | return -1; | |
609 | if (k1->offset > k2->offset) | |
610 | return 1; | |
611 | if (k1->offset < k2->offset) | |
612 | return -1; | |
613 | return 0; | |
614 | } | |
081e9573 | 615 | |
d352ac68 CM |
616 | /* |
617 | * this is used by the defrag code to go through all the | |
618 | * leaves pointed to by a node and reallocate them so that | |
619 | * disk order is close to key order | |
620 | */ | |
6702ed49 | 621 | int btrfs_realloc_node(struct btrfs_trans_handle *trans, |
5f39d397 | 622 | struct btrfs_root *root, struct extent_buffer *parent, |
a6b6e75e CM |
623 | int start_slot, int cache_only, u64 *last_ret, |
624 | struct btrfs_key *progress) | |
6702ed49 | 625 | { |
6b80053d | 626 | struct extent_buffer *cur; |
6702ed49 | 627 | u64 blocknr; |
ca7a79ad | 628 | u64 gen; |
e9d0b13b CM |
629 | u64 search_start = *last_ret; |
630 | u64 last_block = 0; | |
6702ed49 CM |
631 | u64 other; |
632 | u32 parent_nritems; | |
6702ed49 CM |
633 | int end_slot; |
634 | int i; | |
635 | int err = 0; | |
f2183bde | 636 | int parent_level; |
6b80053d CM |
637 | int uptodate; |
638 | u32 blocksize; | |
081e9573 CM |
639 | int progress_passed = 0; |
640 | struct btrfs_disk_key disk_key; | |
6702ed49 | 641 | |
5708b959 CM |
642 | parent_level = btrfs_header_level(parent); |
643 | if (cache_only && parent_level != 1) | |
644 | return 0; | |
645 | ||
d397712b | 646 | if (trans->transaction != root->fs_info->running_transaction) |
6702ed49 | 647 | WARN_ON(1); |
d397712b | 648 | if (trans->transid != root->fs_info->generation) |
6702ed49 | 649 | WARN_ON(1); |
86479a04 | 650 | |
6b80053d | 651 | parent_nritems = btrfs_header_nritems(parent); |
6b80053d | 652 | blocksize = btrfs_level_size(root, parent_level - 1); |
6702ed49 CM |
653 | end_slot = parent_nritems; |
654 | ||
655 | if (parent_nritems == 1) | |
656 | return 0; | |
657 | ||
b4ce94de CM |
658 | btrfs_set_lock_blocking(parent); |
659 | ||
6702ed49 CM |
660 | for (i = start_slot; i < end_slot; i++) { |
661 | int close = 1; | |
a6b6e75e | 662 | |
081e9573 CM |
663 | btrfs_node_key(parent, &disk_key, i); |
664 | if (!progress_passed && comp_keys(&disk_key, progress) < 0) | |
665 | continue; | |
666 | ||
667 | progress_passed = 1; | |
6b80053d | 668 | blocknr = btrfs_node_blockptr(parent, i); |
ca7a79ad | 669 | gen = btrfs_node_ptr_generation(parent, i); |
e9d0b13b CM |
670 | if (last_block == 0) |
671 | last_block = blocknr; | |
5708b959 | 672 | |
6702ed49 | 673 | if (i > 0) { |
6b80053d CM |
674 | other = btrfs_node_blockptr(parent, i - 1); |
675 | close = close_blocks(blocknr, other, blocksize); | |
6702ed49 | 676 | } |
0ef3e66b | 677 | if (!close && i < end_slot - 2) { |
6b80053d CM |
678 | other = btrfs_node_blockptr(parent, i + 1); |
679 | close = close_blocks(blocknr, other, blocksize); | |
6702ed49 | 680 | } |
e9d0b13b CM |
681 | if (close) { |
682 | last_block = blocknr; | |
6702ed49 | 683 | continue; |
e9d0b13b | 684 | } |
6702ed49 | 685 | |
6b80053d CM |
686 | cur = btrfs_find_tree_block(root, blocknr, blocksize); |
687 | if (cur) | |
1259ab75 | 688 | uptodate = btrfs_buffer_uptodate(cur, gen); |
6b80053d CM |
689 | else |
690 | uptodate = 0; | |
5708b959 | 691 | if (!cur || !uptodate) { |
6702ed49 | 692 | if (cache_only) { |
6b80053d | 693 | free_extent_buffer(cur); |
6702ed49 CM |
694 | continue; |
695 | } | |
6b80053d CM |
696 | if (!cur) { |
697 | cur = read_tree_block(root, blocknr, | |
ca7a79ad | 698 | blocksize, gen); |
97d9a8a4 TI |
699 | if (!cur) |
700 | return -EIO; | |
6b80053d | 701 | } else if (!uptodate) { |
ca7a79ad | 702 | btrfs_read_buffer(cur, gen); |
f2183bde | 703 | } |
6702ed49 | 704 | } |
e9d0b13b | 705 | if (search_start == 0) |
6b80053d | 706 | search_start = last_block; |
e9d0b13b | 707 | |
e7a84565 | 708 | btrfs_tree_lock(cur); |
b4ce94de | 709 | btrfs_set_lock_blocking(cur); |
6b80053d | 710 | err = __btrfs_cow_block(trans, root, cur, parent, i, |
e7a84565 | 711 | &cur, search_start, |
6b80053d | 712 | min(16 * blocksize, |
9fa8cfe7 | 713 | (end_slot - i) * blocksize)); |
252c38f0 | 714 | if (err) { |
e7a84565 | 715 | btrfs_tree_unlock(cur); |
6b80053d | 716 | free_extent_buffer(cur); |
6702ed49 | 717 | break; |
252c38f0 | 718 | } |
e7a84565 CM |
719 | search_start = cur->start; |
720 | last_block = cur->start; | |
f2183bde | 721 | *last_ret = search_start; |
e7a84565 CM |
722 | btrfs_tree_unlock(cur); |
723 | free_extent_buffer(cur); | |
6702ed49 CM |
724 | } |
725 | return err; | |
726 | } | |
727 | ||
74123bd7 CM |
728 | /* |
729 | * The leaf data grows from end-to-front in the node. | |
730 | * this returns the address of the start of the last item, | |
731 | * which is the stop of the leaf data stack | |
732 | */ | |
123abc88 | 733 | static inline unsigned int leaf_data_end(struct btrfs_root *root, |
5f39d397 | 734 | struct extent_buffer *leaf) |
be0e5c09 | 735 | { |
5f39d397 | 736 | u32 nr = btrfs_header_nritems(leaf); |
be0e5c09 | 737 | if (nr == 0) |
123abc88 | 738 | return BTRFS_LEAF_DATA_SIZE(root); |
5f39d397 | 739 | return btrfs_item_offset_nr(leaf, nr - 1); |
be0e5c09 CM |
740 | } |
741 | ||
aa5d6bed | 742 | |
74123bd7 | 743 | /* |
5f39d397 CM |
744 | * search for key in the extent_buffer. The items start at offset p, |
745 | * and they are item_size apart. There are 'max' items in p. | |
746 | * | |
74123bd7 CM |
747 | * the slot in the array is returned via slot, and it points to |
748 | * the place where you would insert key if it is not found in | |
749 | * the array. | |
750 | * | |
751 | * slot may point to max if the key is bigger than all of the keys | |
752 | */ | |
e02119d5 CM |
753 | static noinline int generic_bin_search(struct extent_buffer *eb, |
754 | unsigned long p, | |
755 | int item_size, struct btrfs_key *key, | |
756 | int max, int *slot) | |
be0e5c09 CM |
757 | { |
758 | int low = 0; | |
759 | int high = max; | |
760 | int mid; | |
761 | int ret; | |
479965d6 | 762 | struct btrfs_disk_key *tmp = NULL; |
5f39d397 CM |
763 | struct btrfs_disk_key unaligned; |
764 | unsigned long offset; | |
5f39d397 CM |
765 | char *kaddr = NULL; |
766 | unsigned long map_start = 0; | |
767 | unsigned long map_len = 0; | |
479965d6 | 768 | int err; |
be0e5c09 | 769 | |
d397712b | 770 | while (low < high) { |
be0e5c09 | 771 | mid = (low + high) / 2; |
5f39d397 CM |
772 | offset = p + mid * item_size; |
773 | ||
a6591715 | 774 | if (!kaddr || offset < map_start || |
5f39d397 CM |
775 | (offset + sizeof(struct btrfs_disk_key)) > |
776 | map_start + map_len) { | |
934d375b CM |
777 | |
778 | err = map_private_extent_buffer(eb, offset, | |
479965d6 | 779 | sizeof(struct btrfs_disk_key), |
a6591715 | 780 | &kaddr, &map_start, &map_len); |
479965d6 CM |
781 | |
782 | if (!err) { | |
783 | tmp = (struct btrfs_disk_key *)(kaddr + offset - | |
784 | map_start); | |
785 | } else { | |
786 | read_extent_buffer(eb, &unaligned, | |
787 | offset, sizeof(unaligned)); | |
788 | tmp = &unaligned; | |
789 | } | |
5f39d397 | 790 | |
5f39d397 CM |
791 | } else { |
792 | tmp = (struct btrfs_disk_key *)(kaddr + offset - | |
793 | map_start); | |
794 | } | |
be0e5c09 CM |
795 | ret = comp_keys(tmp, key); |
796 | ||
797 | if (ret < 0) | |
798 | low = mid + 1; | |
799 | else if (ret > 0) | |
800 | high = mid; | |
801 | else { | |
802 | *slot = mid; | |
803 | return 0; | |
804 | } | |
805 | } | |
806 | *slot = low; | |
807 | return 1; | |
808 | } | |
809 | ||
97571fd0 CM |
810 | /* |
811 | * simple bin_search frontend that does the right thing for | |
812 | * leaves vs nodes | |
813 | */ | |
5f39d397 CM |
814 | static int bin_search(struct extent_buffer *eb, struct btrfs_key *key, |
815 | int level, int *slot) | |
be0e5c09 | 816 | { |
5f39d397 CM |
817 | if (level == 0) { |
818 | return generic_bin_search(eb, | |
819 | offsetof(struct btrfs_leaf, items), | |
0783fcfc | 820 | sizeof(struct btrfs_item), |
5f39d397 | 821 | key, btrfs_header_nritems(eb), |
7518a238 | 822 | slot); |
be0e5c09 | 823 | } else { |
5f39d397 CM |
824 | return generic_bin_search(eb, |
825 | offsetof(struct btrfs_node, ptrs), | |
123abc88 | 826 | sizeof(struct btrfs_key_ptr), |
5f39d397 | 827 | key, btrfs_header_nritems(eb), |
7518a238 | 828 | slot); |
be0e5c09 CM |
829 | } |
830 | return -1; | |
831 | } | |
832 | ||
5d4f98a2 YZ |
833 | int btrfs_bin_search(struct extent_buffer *eb, struct btrfs_key *key, |
834 | int level, int *slot) | |
835 | { | |
836 | return bin_search(eb, key, level, slot); | |
837 | } | |
838 | ||
f0486c68 YZ |
839 | static void root_add_used(struct btrfs_root *root, u32 size) |
840 | { | |
841 | spin_lock(&root->accounting_lock); | |
842 | btrfs_set_root_used(&root->root_item, | |
843 | btrfs_root_used(&root->root_item) + size); | |
844 | spin_unlock(&root->accounting_lock); | |
845 | } | |
846 | ||
847 | static void root_sub_used(struct btrfs_root *root, u32 size) | |
848 | { | |
849 | spin_lock(&root->accounting_lock); | |
850 | btrfs_set_root_used(&root->root_item, | |
851 | btrfs_root_used(&root->root_item) - size); | |
852 | spin_unlock(&root->accounting_lock); | |
853 | } | |
854 | ||
d352ac68 CM |
855 | /* given a node and slot number, this reads the blocks it points to. The |
856 | * extent buffer is returned with a reference taken (but unlocked). | |
857 | * NULL is returned on error. | |
858 | */ | |
e02119d5 | 859 | static noinline struct extent_buffer *read_node_slot(struct btrfs_root *root, |
5f39d397 | 860 | struct extent_buffer *parent, int slot) |
bb803951 | 861 | { |
ca7a79ad | 862 | int level = btrfs_header_level(parent); |
bb803951 CM |
863 | if (slot < 0) |
864 | return NULL; | |
5f39d397 | 865 | if (slot >= btrfs_header_nritems(parent)) |
bb803951 | 866 | return NULL; |
ca7a79ad CM |
867 | |
868 | BUG_ON(level == 0); | |
869 | ||
db94535d | 870 | return read_tree_block(root, btrfs_node_blockptr(parent, slot), |
ca7a79ad CM |
871 | btrfs_level_size(root, level - 1), |
872 | btrfs_node_ptr_generation(parent, slot)); | |
bb803951 CM |
873 | } |
874 | ||
d352ac68 CM |
875 | /* |
876 | * node level balancing, used to make sure nodes are in proper order for | |
877 | * item deletion. We balance from the top down, so we have to make sure | |
878 | * that a deletion won't leave an node completely empty later on. | |
879 | */ | |
e02119d5 | 880 | static noinline int balance_level(struct btrfs_trans_handle *trans, |
98ed5174 CM |
881 | struct btrfs_root *root, |
882 | struct btrfs_path *path, int level) | |
bb803951 | 883 | { |
5f39d397 CM |
884 | struct extent_buffer *right = NULL; |
885 | struct extent_buffer *mid; | |
886 | struct extent_buffer *left = NULL; | |
887 | struct extent_buffer *parent = NULL; | |
bb803951 CM |
888 | int ret = 0; |
889 | int wret; | |
890 | int pslot; | |
bb803951 | 891 | int orig_slot = path->slots[level]; |
79f95c82 | 892 | u64 orig_ptr; |
bb803951 CM |
893 | |
894 | if (level == 0) | |
895 | return 0; | |
896 | ||
5f39d397 | 897 | mid = path->nodes[level]; |
b4ce94de | 898 | |
bd681513 CM |
899 | WARN_ON(path->locks[level] != BTRFS_WRITE_LOCK && |
900 | path->locks[level] != BTRFS_WRITE_LOCK_BLOCKING); | |
7bb86316 CM |
901 | WARN_ON(btrfs_header_generation(mid) != trans->transid); |
902 | ||
1d4f8a0c | 903 | orig_ptr = btrfs_node_blockptr(mid, orig_slot); |
79f95c82 | 904 | |
234b63a0 | 905 | if (level < BTRFS_MAX_LEVEL - 1) |
5f39d397 | 906 | parent = path->nodes[level + 1]; |
bb803951 CM |
907 | pslot = path->slots[level + 1]; |
908 | ||
40689478 CM |
909 | /* |
910 | * deal with the case where there is only one pointer in the root | |
911 | * by promoting the node below to a root | |
912 | */ | |
5f39d397 CM |
913 | if (!parent) { |
914 | struct extent_buffer *child; | |
bb803951 | 915 | |
5f39d397 | 916 | if (btrfs_header_nritems(mid) != 1) |
bb803951 CM |
917 | return 0; |
918 | ||
919 | /* promote the child to a root */ | |
5f39d397 | 920 | child = read_node_slot(root, mid, 0); |
7951f3ce | 921 | BUG_ON(!child); |
925baedd | 922 | btrfs_tree_lock(child); |
b4ce94de | 923 | btrfs_set_lock_blocking(child); |
9fa8cfe7 | 924 | ret = btrfs_cow_block(trans, root, child, mid, 0, &child); |
f0486c68 YZ |
925 | if (ret) { |
926 | btrfs_tree_unlock(child); | |
927 | free_extent_buffer(child); | |
928 | goto enospc; | |
929 | } | |
2f375ab9 | 930 | |
240f62c8 | 931 | rcu_assign_pointer(root->node, child); |
925baedd | 932 | |
0b86a832 | 933 | add_root_to_dirty_list(root); |
925baedd | 934 | btrfs_tree_unlock(child); |
b4ce94de | 935 | |
925baedd | 936 | path->locks[level] = 0; |
bb803951 | 937 | path->nodes[level] = NULL; |
5f39d397 | 938 | clean_tree_block(trans, root, mid); |
925baedd | 939 | btrfs_tree_unlock(mid); |
bb803951 | 940 | /* once for the path */ |
5f39d397 | 941 | free_extent_buffer(mid); |
f0486c68 YZ |
942 | |
943 | root_sub_used(root, mid->len); | |
944 | btrfs_free_tree_block(trans, root, mid, 0, 1); | |
bb803951 | 945 | /* once for the root ptr */ |
5f39d397 | 946 | free_extent_buffer(mid); |
f0486c68 | 947 | return 0; |
bb803951 | 948 | } |
5f39d397 | 949 | if (btrfs_header_nritems(mid) > |
123abc88 | 950 | BTRFS_NODEPTRS_PER_BLOCK(root) / 4) |
bb803951 CM |
951 | return 0; |
952 | ||
559af821 | 953 | btrfs_header_nritems(mid); |
54aa1f4d | 954 | |
5f39d397 CM |
955 | left = read_node_slot(root, parent, pslot - 1); |
956 | if (left) { | |
925baedd | 957 | btrfs_tree_lock(left); |
b4ce94de | 958 | btrfs_set_lock_blocking(left); |
5f39d397 | 959 | wret = btrfs_cow_block(trans, root, left, |
9fa8cfe7 | 960 | parent, pslot - 1, &left); |
54aa1f4d CM |
961 | if (wret) { |
962 | ret = wret; | |
963 | goto enospc; | |
964 | } | |
2cc58cf2 | 965 | } |
5f39d397 CM |
966 | right = read_node_slot(root, parent, pslot + 1); |
967 | if (right) { | |
925baedd | 968 | btrfs_tree_lock(right); |
b4ce94de | 969 | btrfs_set_lock_blocking(right); |
5f39d397 | 970 | wret = btrfs_cow_block(trans, root, right, |
9fa8cfe7 | 971 | parent, pslot + 1, &right); |
2cc58cf2 CM |
972 | if (wret) { |
973 | ret = wret; | |
974 | goto enospc; | |
975 | } | |
976 | } | |
977 | ||
978 | /* first, try to make some room in the middle buffer */ | |
5f39d397 CM |
979 | if (left) { |
980 | orig_slot += btrfs_header_nritems(left); | |
bce4eae9 | 981 | wret = push_node_left(trans, root, left, mid, 1); |
79f95c82 CM |
982 | if (wret < 0) |
983 | ret = wret; | |
559af821 | 984 | btrfs_header_nritems(mid); |
bb803951 | 985 | } |
79f95c82 CM |
986 | |
987 | /* | |
988 | * then try to empty the right most buffer into the middle | |
989 | */ | |
5f39d397 | 990 | if (right) { |
971a1f66 | 991 | wret = push_node_left(trans, root, mid, right, 1); |
54aa1f4d | 992 | if (wret < 0 && wret != -ENOSPC) |
79f95c82 | 993 | ret = wret; |
5f39d397 | 994 | if (btrfs_header_nritems(right) == 0) { |
5f39d397 | 995 | clean_tree_block(trans, root, right); |
925baedd | 996 | btrfs_tree_unlock(right); |
e089f05c CM |
997 | wret = del_ptr(trans, root, path, level + 1, pslot + |
998 | 1); | |
bb803951 CM |
999 | if (wret) |
1000 | ret = wret; | |
f0486c68 YZ |
1001 | root_sub_used(root, right->len); |
1002 | btrfs_free_tree_block(trans, root, right, 0, 1); | |
1003 | free_extent_buffer(right); | |
1004 | right = NULL; | |
bb803951 | 1005 | } else { |
5f39d397 CM |
1006 | struct btrfs_disk_key right_key; |
1007 | btrfs_node_key(right, &right_key, 0); | |
1008 | btrfs_set_node_key(parent, &right_key, pslot + 1); | |
1009 | btrfs_mark_buffer_dirty(parent); | |
bb803951 CM |
1010 | } |
1011 | } | |
5f39d397 | 1012 | if (btrfs_header_nritems(mid) == 1) { |
79f95c82 CM |
1013 | /* |
1014 | * we're not allowed to leave a node with one item in the | |
1015 | * tree during a delete. A deletion from lower in the tree | |
1016 | * could try to delete the only pointer in this node. | |
1017 | * So, pull some keys from the left. | |
1018 | * There has to be a left pointer at this point because | |
1019 | * otherwise we would have pulled some pointers from the | |
1020 | * right | |
1021 | */ | |
5f39d397 CM |
1022 | BUG_ON(!left); |
1023 | wret = balance_node_right(trans, root, mid, left); | |
54aa1f4d | 1024 | if (wret < 0) { |
79f95c82 | 1025 | ret = wret; |
54aa1f4d CM |
1026 | goto enospc; |
1027 | } | |
bce4eae9 CM |
1028 | if (wret == 1) { |
1029 | wret = push_node_left(trans, root, left, mid, 1); | |
1030 | if (wret < 0) | |
1031 | ret = wret; | |
1032 | } | |
79f95c82 CM |
1033 | BUG_ON(wret == 1); |
1034 | } | |
5f39d397 | 1035 | if (btrfs_header_nritems(mid) == 0) { |
5f39d397 | 1036 | clean_tree_block(trans, root, mid); |
925baedd | 1037 | btrfs_tree_unlock(mid); |
e089f05c | 1038 | wret = del_ptr(trans, root, path, level + 1, pslot); |
bb803951 CM |
1039 | if (wret) |
1040 | ret = wret; | |
f0486c68 YZ |
1041 | root_sub_used(root, mid->len); |
1042 | btrfs_free_tree_block(trans, root, mid, 0, 1); | |
1043 | free_extent_buffer(mid); | |
1044 | mid = NULL; | |
79f95c82 CM |
1045 | } else { |
1046 | /* update the parent key to reflect our changes */ | |
5f39d397 CM |
1047 | struct btrfs_disk_key mid_key; |
1048 | btrfs_node_key(mid, &mid_key, 0); | |
1049 | btrfs_set_node_key(parent, &mid_key, pslot); | |
1050 | btrfs_mark_buffer_dirty(parent); | |
79f95c82 | 1051 | } |
bb803951 | 1052 | |
79f95c82 | 1053 | /* update the path */ |
5f39d397 CM |
1054 | if (left) { |
1055 | if (btrfs_header_nritems(left) > orig_slot) { | |
1056 | extent_buffer_get(left); | |
925baedd | 1057 | /* left was locked after cow */ |
5f39d397 | 1058 | path->nodes[level] = left; |
bb803951 CM |
1059 | path->slots[level + 1] -= 1; |
1060 | path->slots[level] = orig_slot; | |
925baedd CM |
1061 | if (mid) { |
1062 | btrfs_tree_unlock(mid); | |
5f39d397 | 1063 | free_extent_buffer(mid); |
925baedd | 1064 | } |
bb803951 | 1065 | } else { |
5f39d397 | 1066 | orig_slot -= btrfs_header_nritems(left); |
bb803951 CM |
1067 | path->slots[level] = orig_slot; |
1068 | } | |
1069 | } | |
79f95c82 | 1070 | /* double check we haven't messed things up */ |
e20d96d6 | 1071 | if (orig_ptr != |
5f39d397 | 1072 | btrfs_node_blockptr(path->nodes[level], path->slots[level])) |
79f95c82 | 1073 | BUG(); |
54aa1f4d | 1074 | enospc: |
925baedd CM |
1075 | if (right) { |
1076 | btrfs_tree_unlock(right); | |
5f39d397 | 1077 | free_extent_buffer(right); |
925baedd CM |
1078 | } |
1079 | if (left) { | |
1080 | if (path->nodes[level] != left) | |
1081 | btrfs_tree_unlock(left); | |
5f39d397 | 1082 | free_extent_buffer(left); |
925baedd | 1083 | } |
bb803951 CM |
1084 | return ret; |
1085 | } | |
1086 | ||
d352ac68 CM |
1087 | /* Node balancing for insertion. Here we only split or push nodes around |
1088 | * when they are completely full. This is also done top down, so we | |
1089 | * have to be pessimistic. | |
1090 | */ | |
d397712b | 1091 | static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans, |
98ed5174 CM |
1092 | struct btrfs_root *root, |
1093 | struct btrfs_path *path, int level) | |
e66f709b | 1094 | { |
5f39d397 CM |
1095 | struct extent_buffer *right = NULL; |
1096 | struct extent_buffer *mid; | |
1097 | struct extent_buffer *left = NULL; | |
1098 | struct extent_buffer *parent = NULL; | |
e66f709b CM |
1099 | int ret = 0; |
1100 | int wret; | |
1101 | int pslot; | |
1102 | int orig_slot = path->slots[level]; | |
e66f709b CM |
1103 | |
1104 | if (level == 0) | |
1105 | return 1; | |
1106 | ||
5f39d397 | 1107 | mid = path->nodes[level]; |
7bb86316 | 1108 | WARN_ON(btrfs_header_generation(mid) != trans->transid); |
e66f709b CM |
1109 | |
1110 | if (level < BTRFS_MAX_LEVEL - 1) | |
5f39d397 | 1111 | parent = path->nodes[level + 1]; |
e66f709b CM |
1112 | pslot = path->slots[level + 1]; |
1113 | ||
5f39d397 | 1114 | if (!parent) |
e66f709b | 1115 | return 1; |
e66f709b | 1116 | |
5f39d397 | 1117 | left = read_node_slot(root, parent, pslot - 1); |
e66f709b CM |
1118 | |
1119 | /* first, try to make some room in the middle buffer */ | |
5f39d397 | 1120 | if (left) { |
e66f709b | 1121 | u32 left_nr; |
925baedd CM |
1122 | |
1123 | btrfs_tree_lock(left); | |
b4ce94de CM |
1124 | btrfs_set_lock_blocking(left); |
1125 | ||
5f39d397 | 1126 | left_nr = btrfs_header_nritems(left); |
33ade1f8 CM |
1127 | if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) { |
1128 | wret = 1; | |
1129 | } else { | |
5f39d397 | 1130 | ret = btrfs_cow_block(trans, root, left, parent, |
9fa8cfe7 | 1131 | pslot - 1, &left); |
54aa1f4d CM |
1132 | if (ret) |
1133 | wret = 1; | |
1134 | else { | |
54aa1f4d | 1135 | wret = push_node_left(trans, root, |
971a1f66 | 1136 | left, mid, 0); |
54aa1f4d | 1137 | } |
33ade1f8 | 1138 | } |
e66f709b CM |
1139 | if (wret < 0) |
1140 | ret = wret; | |
1141 | if (wret == 0) { | |
5f39d397 | 1142 | struct btrfs_disk_key disk_key; |
e66f709b | 1143 | orig_slot += left_nr; |
5f39d397 CM |
1144 | btrfs_node_key(mid, &disk_key, 0); |
1145 | btrfs_set_node_key(parent, &disk_key, pslot); | |
1146 | btrfs_mark_buffer_dirty(parent); | |
1147 | if (btrfs_header_nritems(left) > orig_slot) { | |
1148 | path->nodes[level] = left; | |
e66f709b CM |
1149 | path->slots[level + 1] -= 1; |
1150 | path->slots[level] = orig_slot; | |
925baedd | 1151 | btrfs_tree_unlock(mid); |
5f39d397 | 1152 | free_extent_buffer(mid); |
e66f709b CM |
1153 | } else { |
1154 | orig_slot -= | |
5f39d397 | 1155 | btrfs_header_nritems(left); |
e66f709b | 1156 | path->slots[level] = orig_slot; |
925baedd | 1157 | btrfs_tree_unlock(left); |
5f39d397 | 1158 | free_extent_buffer(left); |
e66f709b | 1159 | } |
e66f709b CM |
1160 | return 0; |
1161 | } | |
925baedd | 1162 | btrfs_tree_unlock(left); |
5f39d397 | 1163 | free_extent_buffer(left); |
e66f709b | 1164 | } |
925baedd | 1165 | right = read_node_slot(root, parent, pslot + 1); |
e66f709b CM |
1166 | |
1167 | /* | |
1168 | * then try to empty the right most buffer into the middle | |
1169 | */ | |
5f39d397 | 1170 | if (right) { |
33ade1f8 | 1171 | u32 right_nr; |
b4ce94de | 1172 | |
925baedd | 1173 | btrfs_tree_lock(right); |
b4ce94de CM |
1174 | btrfs_set_lock_blocking(right); |
1175 | ||
5f39d397 | 1176 | right_nr = btrfs_header_nritems(right); |
33ade1f8 CM |
1177 | if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) { |
1178 | wret = 1; | |
1179 | } else { | |
5f39d397 CM |
1180 | ret = btrfs_cow_block(trans, root, right, |
1181 | parent, pslot + 1, | |
9fa8cfe7 | 1182 | &right); |
54aa1f4d CM |
1183 | if (ret) |
1184 | wret = 1; | |
1185 | else { | |
54aa1f4d | 1186 | wret = balance_node_right(trans, root, |
5f39d397 | 1187 | right, mid); |
54aa1f4d | 1188 | } |
33ade1f8 | 1189 | } |
e66f709b CM |
1190 | if (wret < 0) |
1191 | ret = wret; | |
1192 | if (wret == 0) { | |
5f39d397 CM |
1193 | struct btrfs_disk_key disk_key; |
1194 | ||
1195 | btrfs_node_key(right, &disk_key, 0); | |
1196 | btrfs_set_node_key(parent, &disk_key, pslot + 1); | |
1197 | btrfs_mark_buffer_dirty(parent); | |
1198 | ||
1199 | if (btrfs_header_nritems(mid) <= orig_slot) { | |
1200 | path->nodes[level] = right; | |
e66f709b CM |
1201 | path->slots[level + 1] += 1; |
1202 | path->slots[level] = orig_slot - | |
5f39d397 | 1203 | btrfs_header_nritems(mid); |
925baedd | 1204 | btrfs_tree_unlock(mid); |
5f39d397 | 1205 | free_extent_buffer(mid); |
e66f709b | 1206 | } else { |
925baedd | 1207 | btrfs_tree_unlock(right); |
5f39d397 | 1208 | free_extent_buffer(right); |
e66f709b | 1209 | } |
e66f709b CM |
1210 | return 0; |
1211 | } | |
925baedd | 1212 | btrfs_tree_unlock(right); |
5f39d397 | 1213 | free_extent_buffer(right); |
e66f709b | 1214 | } |
e66f709b CM |
1215 | return 1; |
1216 | } | |
1217 | ||
3c69faec | 1218 | /* |
d352ac68 CM |
1219 | * readahead one full node of leaves, finding things that are close |
1220 | * to the block in 'slot', and triggering ra on them. | |
3c69faec | 1221 | */ |
c8c42864 CM |
1222 | static void reada_for_search(struct btrfs_root *root, |
1223 | struct btrfs_path *path, | |
1224 | int level, int slot, u64 objectid) | |
3c69faec | 1225 | { |
5f39d397 | 1226 | struct extent_buffer *node; |
01f46658 | 1227 | struct btrfs_disk_key disk_key; |
3c69faec | 1228 | u32 nritems; |
3c69faec | 1229 | u64 search; |
a7175319 | 1230 | u64 target; |
6b80053d | 1231 | u64 nread = 0; |
cb25c2ea | 1232 | u64 gen; |
3c69faec | 1233 | int direction = path->reada; |
5f39d397 | 1234 | struct extent_buffer *eb; |
6b80053d CM |
1235 | u32 nr; |
1236 | u32 blocksize; | |
1237 | u32 nscan = 0; | |
db94535d | 1238 | |
a6b6e75e | 1239 | if (level != 1) |
6702ed49 CM |
1240 | return; |
1241 | ||
1242 | if (!path->nodes[level]) | |
3c69faec CM |
1243 | return; |
1244 | ||
5f39d397 | 1245 | node = path->nodes[level]; |
925baedd | 1246 | |
3c69faec | 1247 | search = btrfs_node_blockptr(node, slot); |
6b80053d CM |
1248 | blocksize = btrfs_level_size(root, level - 1); |
1249 | eb = btrfs_find_tree_block(root, search, blocksize); | |
5f39d397 CM |
1250 | if (eb) { |
1251 | free_extent_buffer(eb); | |
3c69faec CM |
1252 | return; |
1253 | } | |
1254 | ||
a7175319 | 1255 | target = search; |
6b80053d | 1256 | |
5f39d397 | 1257 | nritems = btrfs_header_nritems(node); |
6b80053d | 1258 | nr = slot; |
25b8b936 | 1259 | |
d397712b | 1260 | while (1) { |
6b80053d CM |
1261 | if (direction < 0) { |
1262 | if (nr == 0) | |
1263 | break; | |
1264 | nr--; | |
1265 | } else if (direction > 0) { | |
1266 | nr++; | |
1267 | if (nr >= nritems) | |
1268 | break; | |
3c69faec | 1269 | } |
01f46658 CM |
1270 | if (path->reada < 0 && objectid) { |
1271 | btrfs_node_key(node, &disk_key, nr); | |
1272 | if (btrfs_disk_key_objectid(&disk_key) != objectid) | |
1273 | break; | |
1274 | } | |
6b80053d | 1275 | search = btrfs_node_blockptr(node, nr); |
a7175319 CM |
1276 | if ((search <= target && target - search <= 65536) || |
1277 | (search > target && search - target <= 65536)) { | |
cb25c2ea | 1278 | gen = btrfs_node_ptr_generation(node, nr); |
cb25c2ea | 1279 | readahead_tree_block(root, search, blocksize, gen); |
6b80053d CM |
1280 | nread += blocksize; |
1281 | } | |
1282 | nscan++; | |
a7175319 | 1283 | if ((nread > 65536 || nscan > 32)) |
6b80053d | 1284 | break; |
3c69faec CM |
1285 | } |
1286 | } | |
925baedd | 1287 | |
b4ce94de CM |
1288 | /* |
1289 | * returns -EAGAIN if it had to drop the path, or zero if everything was in | |
1290 | * cache | |
1291 | */ | |
1292 | static noinline int reada_for_balance(struct btrfs_root *root, | |
1293 | struct btrfs_path *path, int level) | |
1294 | { | |
1295 | int slot; | |
1296 | int nritems; | |
1297 | struct extent_buffer *parent; | |
1298 | struct extent_buffer *eb; | |
1299 | u64 gen; | |
1300 | u64 block1 = 0; | |
1301 | u64 block2 = 0; | |
1302 | int ret = 0; | |
1303 | int blocksize; | |
1304 | ||
8c594ea8 | 1305 | parent = path->nodes[level + 1]; |
b4ce94de CM |
1306 | if (!parent) |
1307 | return 0; | |
1308 | ||
1309 | nritems = btrfs_header_nritems(parent); | |
8c594ea8 | 1310 | slot = path->slots[level + 1]; |
b4ce94de CM |
1311 | blocksize = btrfs_level_size(root, level); |
1312 | ||
1313 | if (slot > 0) { | |
1314 | block1 = btrfs_node_blockptr(parent, slot - 1); | |
1315 | gen = btrfs_node_ptr_generation(parent, slot - 1); | |
1316 | eb = btrfs_find_tree_block(root, block1, blocksize); | |
1317 | if (eb && btrfs_buffer_uptodate(eb, gen)) | |
1318 | block1 = 0; | |
1319 | free_extent_buffer(eb); | |
1320 | } | |
8c594ea8 | 1321 | if (slot + 1 < nritems) { |
b4ce94de CM |
1322 | block2 = btrfs_node_blockptr(parent, slot + 1); |
1323 | gen = btrfs_node_ptr_generation(parent, slot + 1); | |
1324 | eb = btrfs_find_tree_block(root, block2, blocksize); | |
1325 | if (eb && btrfs_buffer_uptodate(eb, gen)) | |
1326 | block2 = 0; | |
1327 | free_extent_buffer(eb); | |
1328 | } | |
1329 | if (block1 || block2) { | |
1330 | ret = -EAGAIN; | |
8c594ea8 CM |
1331 | |
1332 | /* release the whole path */ | |
b3b4aa74 | 1333 | btrfs_release_path(path); |
8c594ea8 CM |
1334 | |
1335 | /* read the blocks */ | |
b4ce94de CM |
1336 | if (block1) |
1337 | readahead_tree_block(root, block1, blocksize, 0); | |
1338 | if (block2) | |
1339 | readahead_tree_block(root, block2, blocksize, 0); | |
1340 | ||
1341 | if (block1) { | |
1342 | eb = read_tree_block(root, block1, blocksize, 0); | |
1343 | free_extent_buffer(eb); | |
1344 | } | |
8c594ea8 | 1345 | if (block2) { |
b4ce94de CM |
1346 | eb = read_tree_block(root, block2, blocksize, 0); |
1347 | free_extent_buffer(eb); | |
1348 | } | |
1349 | } | |
1350 | return ret; | |
1351 | } | |
1352 | ||
1353 | ||
d352ac68 | 1354 | /* |
d397712b CM |
1355 | * when we walk down the tree, it is usually safe to unlock the higher layers |
1356 | * in the tree. The exceptions are when our path goes through slot 0, because | |
1357 | * operations on the tree might require changing key pointers higher up in the | |
1358 | * tree. | |
d352ac68 | 1359 | * |
d397712b CM |
1360 | * callers might also have set path->keep_locks, which tells this code to keep |
1361 | * the lock if the path points to the last slot in the block. This is part of | |
1362 | * walking through the tree, and selecting the next slot in the higher block. | |
d352ac68 | 1363 | * |
d397712b CM |
1364 | * lowest_unlock sets the lowest level in the tree we're allowed to unlock. so |
1365 | * if lowest_unlock is 1, level 0 won't be unlocked | |
d352ac68 | 1366 | */ |
e02119d5 CM |
1367 | static noinline void unlock_up(struct btrfs_path *path, int level, |
1368 | int lowest_unlock) | |
925baedd CM |
1369 | { |
1370 | int i; | |
1371 | int skip_level = level; | |
051e1b9f | 1372 | int no_skips = 0; |
925baedd CM |
1373 | struct extent_buffer *t; |
1374 | ||
1375 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { | |
1376 | if (!path->nodes[i]) | |
1377 | break; | |
1378 | if (!path->locks[i]) | |
1379 | break; | |
051e1b9f | 1380 | if (!no_skips && path->slots[i] == 0) { |
925baedd CM |
1381 | skip_level = i + 1; |
1382 | continue; | |
1383 | } | |
051e1b9f | 1384 | if (!no_skips && path->keep_locks) { |
925baedd CM |
1385 | u32 nritems; |
1386 | t = path->nodes[i]; | |
1387 | nritems = btrfs_header_nritems(t); | |
051e1b9f | 1388 | if (nritems < 1 || path->slots[i] >= nritems - 1) { |
925baedd CM |
1389 | skip_level = i + 1; |
1390 | continue; | |
1391 | } | |
1392 | } | |
051e1b9f CM |
1393 | if (skip_level < i && i >= lowest_unlock) |
1394 | no_skips = 1; | |
1395 | ||
925baedd CM |
1396 | t = path->nodes[i]; |
1397 | if (i >= lowest_unlock && i > skip_level && path->locks[i]) { | |
bd681513 | 1398 | btrfs_tree_unlock_rw(t, path->locks[i]); |
925baedd CM |
1399 | path->locks[i] = 0; |
1400 | } | |
1401 | } | |
1402 | } | |
1403 | ||
b4ce94de CM |
1404 | /* |
1405 | * This releases any locks held in the path starting at level and | |
1406 | * going all the way up to the root. | |
1407 | * | |
1408 | * btrfs_search_slot will keep the lock held on higher nodes in a few | |
1409 | * corner cases, such as COW of the block at slot zero in the node. This | |
1410 | * ignores those rules, and it should only be called when there are no | |
1411 | * more updates to be done higher up in the tree. | |
1412 | */ | |
1413 | noinline void btrfs_unlock_up_safe(struct btrfs_path *path, int level) | |
1414 | { | |
1415 | int i; | |
1416 | ||
5d4f98a2 | 1417 | if (path->keep_locks) |
b4ce94de CM |
1418 | return; |
1419 | ||
1420 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { | |
1421 | if (!path->nodes[i]) | |
12f4dacc | 1422 | continue; |
b4ce94de | 1423 | if (!path->locks[i]) |
12f4dacc | 1424 | continue; |
bd681513 | 1425 | btrfs_tree_unlock_rw(path->nodes[i], path->locks[i]); |
b4ce94de CM |
1426 | path->locks[i] = 0; |
1427 | } | |
1428 | } | |
1429 | ||
c8c42864 CM |
1430 | /* |
1431 | * helper function for btrfs_search_slot. The goal is to find a block | |
1432 | * in cache without setting the path to blocking. If we find the block | |
1433 | * we return zero and the path is unchanged. | |
1434 | * | |
1435 | * If we can't find the block, we set the path blocking and do some | |
1436 | * reada. -EAGAIN is returned and the search must be repeated. | |
1437 | */ | |
1438 | static int | |
1439 | read_block_for_search(struct btrfs_trans_handle *trans, | |
1440 | struct btrfs_root *root, struct btrfs_path *p, | |
1441 | struct extent_buffer **eb_ret, int level, int slot, | |
1442 | struct btrfs_key *key) | |
1443 | { | |
1444 | u64 blocknr; | |
1445 | u64 gen; | |
1446 | u32 blocksize; | |
1447 | struct extent_buffer *b = *eb_ret; | |
1448 | struct extent_buffer *tmp; | |
76a05b35 | 1449 | int ret; |
c8c42864 CM |
1450 | |
1451 | blocknr = btrfs_node_blockptr(b, slot); | |
1452 | gen = btrfs_node_ptr_generation(b, slot); | |
1453 | blocksize = btrfs_level_size(root, level - 1); | |
1454 | ||
1455 | tmp = btrfs_find_tree_block(root, blocknr, blocksize); | |
cb44921a CM |
1456 | if (tmp) { |
1457 | if (btrfs_buffer_uptodate(tmp, 0)) { | |
1458 | if (btrfs_buffer_uptodate(tmp, gen)) { | |
1459 | /* | |
1460 | * we found an up to date block without | |
1461 | * sleeping, return | |
1462 | * right away | |
1463 | */ | |
1464 | *eb_ret = tmp; | |
1465 | return 0; | |
1466 | } | |
1467 | /* the pages were up to date, but we failed | |
1468 | * the generation number check. Do a full | |
1469 | * read for the generation number that is correct. | |
1470 | * We must do this without dropping locks so | |
1471 | * we can trust our generation number | |
1472 | */ | |
1473 | free_extent_buffer(tmp); | |
bd681513 CM |
1474 | btrfs_set_path_blocking(p); |
1475 | ||
cb44921a CM |
1476 | tmp = read_tree_block(root, blocknr, blocksize, gen); |
1477 | if (tmp && btrfs_buffer_uptodate(tmp, gen)) { | |
1478 | *eb_ret = tmp; | |
1479 | return 0; | |
1480 | } | |
1481 | free_extent_buffer(tmp); | |
b3b4aa74 | 1482 | btrfs_release_path(p); |
cb44921a CM |
1483 | return -EIO; |
1484 | } | |
c8c42864 CM |
1485 | } |
1486 | ||
1487 | /* | |
1488 | * reduce lock contention at high levels | |
1489 | * of the btree by dropping locks before | |
76a05b35 CM |
1490 | * we read. Don't release the lock on the current |
1491 | * level because we need to walk this node to figure | |
1492 | * out which blocks to read. | |
c8c42864 | 1493 | */ |
8c594ea8 CM |
1494 | btrfs_unlock_up_safe(p, level + 1); |
1495 | btrfs_set_path_blocking(p); | |
1496 | ||
cb44921a | 1497 | free_extent_buffer(tmp); |
c8c42864 CM |
1498 | if (p->reada) |
1499 | reada_for_search(root, p, level, slot, key->objectid); | |
1500 | ||
b3b4aa74 | 1501 | btrfs_release_path(p); |
76a05b35 CM |
1502 | |
1503 | ret = -EAGAIN; | |
5bdd3536 | 1504 | tmp = read_tree_block(root, blocknr, blocksize, 0); |
76a05b35 CM |
1505 | if (tmp) { |
1506 | /* | |
1507 | * If the read above didn't mark this buffer up to date, | |
1508 | * it will never end up being up to date. Set ret to EIO now | |
1509 | * and give up so that our caller doesn't loop forever | |
1510 | * on our EAGAINs. | |
1511 | */ | |
1512 | if (!btrfs_buffer_uptodate(tmp, 0)) | |
1513 | ret = -EIO; | |
c8c42864 | 1514 | free_extent_buffer(tmp); |
76a05b35 CM |
1515 | } |
1516 | return ret; | |
c8c42864 CM |
1517 | } |
1518 | ||
1519 | /* | |
1520 | * helper function for btrfs_search_slot. This does all of the checks | |
1521 | * for node-level blocks and does any balancing required based on | |
1522 | * the ins_len. | |
1523 | * | |
1524 | * If no extra work was required, zero is returned. If we had to | |
1525 | * drop the path, -EAGAIN is returned and btrfs_search_slot must | |
1526 | * start over | |
1527 | */ | |
1528 | static int | |
1529 | setup_nodes_for_search(struct btrfs_trans_handle *trans, | |
1530 | struct btrfs_root *root, struct btrfs_path *p, | |
bd681513 CM |
1531 | struct extent_buffer *b, int level, int ins_len, |
1532 | int *write_lock_level) | |
c8c42864 CM |
1533 | { |
1534 | int ret; | |
1535 | if ((p->search_for_split || ins_len > 0) && btrfs_header_nritems(b) >= | |
1536 | BTRFS_NODEPTRS_PER_BLOCK(root) - 3) { | |
1537 | int sret; | |
1538 | ||
bd681513 CM |
1539 | if (*write_lock_level < level + 1) { |
1540 | *write_lock_level = level + 1; | |
1541 | btrfs_release_path(p); | |
1542 | goto again; | |
1543 | } | |
1544 | ||
c8c42864 CM |
1545 | sret = reada_for_balance(root, p, level); |
1546 | if (sret) | |
1547 | goto again; | |
1548 | ||
1549 | btrfs_set_path_blocking(p); | |
1550 | sret = split_node(trans, root, p, level); | |
bd681513 | 1551 | btrfs_clear_path_blocking(p, NULL, 0); |
c8c42864 CM |
1552 | |
1553 | BUG_ON(sret > 0); | |
1554 | if (sret) { | |
1555 | ret = sret; | |
1556 | goto done; | |
1557 | } | |
1558 | b = p->nodes[level]; | |
1559 | } else if (ins_len < 0 && btrfs_header_nritems(b) < | |
cfbb9308 | 1560 | BTRFS_NODEPTRS_PER_BLOCK(root) / 2) { |
c8c42864 CM |
1561 | int sret; |
1562 | ||
bd681513 CM |
1563 | if (*write_lock_level < level + 1) { |
1564 | *write_lock_level = level + 1; | |
1565 | btrfs_release_path(p); | |
1566 | goto again; | |
1567 | } | |
1568 | ||
c8c42864 CM |
1569 | sret = reada_for_balance(root, p, level); |
1570 | if (sret) | |
1571 | goto again; | |
1572 | ||
1573 | btrfs_set_path_blocking(p); | |
1574 | sret = balance_level(trans, root, p, level); | |
bd681513 | 1575 | btrfs_clear_path_blocking(p, NULL, 0); |
c8c42864 CM |
1576 | |
1577 | if (sret) { | |
1578 | ret = sret; | |
1579 | goto done; | |
1580 | } | |
1581 | b = p->nodes[level]; | |
1582 | if (!b) { | |
b3b4aa74 | 1583 | btrfs_release_path(p); |
c8c42864 CM |
1584 | goto again; |
1585 | } | |
1586 | BUG_ON(btrfs_header_nritems(b) == 1); | |
1587 | } | |
1588 | return 0; | |
1589 | ||
1590 | again: | |
1591 | ret = -EAGAIN; | |
1592 | done: | |
1593 | return ret; | |
1594 | } | |
1595 | ||
74123bd7 CM |
1596 | /* |
1597 | * look for key in the tree. path is filled in with nodes along the way | |
1598 | * if key is found, we return zero and you can find the item in the leaf | |
1599 | * level of the path (level 0) | |
1600 | * | |
1601 | * If the key isn't found, the path points to the slot where it should | |
aa5d6bed CM |
1602 | * be inserted, and 1 is returned. If there are other errors during the |
1603 | * search a negative error number is returned. | |
97571fd0 CM |
1604 | * |
1605 | * if ins_len > 0, nodes and leaves will be split as we walk down the | |
1606 | * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if | |
1607 | * possible) | |
74123bd7 | 1608 | */ |
e089f05c CM |
1609 | int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root |
1610 | *root, struct btrfs_key *key, struct btrfs_path *p, int | |
1611 | ins_len, int cow) | |
be0e5c09 | 1612 | { |
5f39d397 | 1613 | struct extent_buffer *b; |
be0e5c09 CM |
1614 | int slot; |
1615 | int ret; | |
33c66f43 | 1616 | int err; |
be0e5c09 | 1617 | int level; |
925baedd | 1618 | int lowest_unlock = 1; |
bd681513 CM |
1619 | int root_lock; |
1620 | /* everything at write_lock_level or lower must be write locked */ | |
1621 | int write_lock_level = 0; | |
9f3a7427 CM |
1622 | u8 lowest_level = 0; |
1623 | ||
6702ed49 | 1624 | lowest_level = p->lowest_level; |
323ac95b | 1625 | WARN_ON(lowest_level && ins_len > 0); |
22b0ebda | 1626 | WARN_ON(p->nodes[0] != NULL); |
25179201 | 1627 | |
bd681513 | 1628 | if (ins_len < 0) { |
925baedd | 1629 | lowest_unlock = 2; |
65b51a00 | 1630 | |
bd681513 CM |
1631 | /* when we are removing items, we might have to go up to level |
1632 | * two as we update tree pointers Make sure we keep write | |
1633 | * for those levels as well | |
1634 | */ | |
1635 | write_lock_level = 2; | |
1636 | } else if (ins_len > 0) { | |
1637 | /* | |
1638 | * for inserting items, make sure we have a write lock on | |
1639 | * level 1 so we can update keys | |
1640 | */ | |
1641 | write_lock_level = 1; | |
1642 | } | |
1643 | ||
1644 | if (!cow) | |
1645 | write_lock_level = -1; | |
1646 | ||
1647 | if (cow && (p->keep_locks || p->lowest_level)) | |
1648 | write_lock_level = BTRFS_MAX_LEVEL; | |
1649 | ||
bb803951 | 1650 | again: |
bd681513 CM |
1651 | /* |
1652 | * we try very hard to do read locks on the root | |
1653 | */ | |
1654 | root_lock = BTRFS_READ_LOCK; | |
1655 | level = 0; | |
5d4f98a2 | 1656 | if (p->search_commit_root) { |
bd681513 CM |
1657 | /* |
1658 | * the commit roots are read only | |
1659 | * so we always do read locks | |
1660 | */ | |
5d4f98a2 YZ |
1661 | b = root->commit_root; |
1662 | extent_buffer_get(b); | |
bd681513 | 1663 | level = btrfs_header_level(b); |
5d4f98a2 | 1664 | if (!p->skip_locking) |
bd681513 | 1665 | btrfs_tree_read_lock(b); |
5d4f98a2 | 1666 | } else { |
bd681513 | 1667 | if (p->skip_locking) { |
5d4f98a2 | 1668 | b = btrfs_root_node(root); |
bd681513 CM |
1669 | level = btrfs_header_level(b); |
1670 | } else { | |
1671 | /* we don't know the level of the root node | |
1672 | * until we actually have it read locked | |
1673 | */ | |
1674 | b = btrfs_read_lock_root_node(root); | |
1675 | level = btrfs_header_level(b); | |
1676 | if (level <= write_lock_level) { | |
1677 | /* whoops, must trade for write lock */ | |
1678 | btrfs_tree_read_unlock(b); | |
1679 | free_extent_buffer(b); | |
1680 | b = btrfs_lock_root_node(root); | |
1681 | root_lock = BTRFS_WRITE_LOCK; | |
1682 | ||
1683 | /* the level might have changed, check again */ | |
1684 | level = btrfs_header_level(b); | |
1685 | } | |
1686 | } | |
5d4f98a2 | 1687 | } |
bd681513 CM |
1688 | p->nodes[level] = b; |
1689 | if (!p->skip_locking) | |
1690 | p->locks[level] = root_lock; | |
925baedd | 1691 | |
eb60ceac | 1692 | while (b) { |
5f39d397 | 1693 | level = btrfs_header_level(b); |
65b51a00 CM |
1694 | |
1695 | /* | |
1696 | * setup the path here so we can release it under lock | |
1697 | * contention with the cow code | |
1698 | */ | |
02217ed2 | 1699 | if (cow) { |
c8c42864 CM |
1700 | /* |
1701 | * if we don't really need to cow this block | |
1702 | * then we don't want to set the path blocking, | |
1703 | * so we test it here | |
1704 | */ | |
5d4f98a2 | 1705 | if (!should_cow_block(trans, root, b)) |
65b51a00 | 1706 | goto cow_done; |
5d4f98a2 | 1707 | |
b4ce94de CM |
1708 | btrfs_set_path_blocking(p); |
1709 | ||
bd681513 CM |
1710 | /* |
1711 | * must have write locks on this node and the | |
1712 | * parent | |
1713 | */ | |
1714 | if (level + 1 > write_lock_level) { | |
1715 | write_lock_level = level + 1; | |
1716 | btrfs_release_path(p); | |
1717 | goto again; | |
1718 | } | |
1719 | ||
33c66f43 YZ |
1720 | err = btrfs_cow_block(trans, root, b, |
1721 | p->nodes[level + 1], | |
1722 | p->slots[level + 1], &b); | |
1723 | if (err) { | |
33c66f43 | 1724 | ret = err; |
65b51a00 | 1725 | goto done; |
54aa1f4d | 1726 | } |
02217ed2 | 1727 | } |
65b51a00 | 1728 | cow_done: |
02217ed2 | 1729 | BUG_ON(!cow && ins_len); |
65b51a00 | 1730 | |
eb60ceac | 1731 | p->nodes[level] = b; |
bd681513 | 1732 | btrfs_clear_path_blocking(p, NULL, 0); |
b4ce94de CM |
1733 | |
1734 | /* | |
1735 | * we have a lock on b and as long as we aren't changing | |
1736 | * the tree, there is no way to for the items in b to change. | |
1737 | * It is safe to drop the lock on our parent before we | |
1738 | * go through the expensive btree search on b. | |
1739 | * | |
1740 | * If cow is true, then we might be changing slot zero, | |
1741 | * which may require changing the parent. So, we can't | |
1742 | * drop the lock until after we know which slot we're | |
1743 | * operating on. | |
1744 | */ | |
1745 | if (!cow) | |
1746 | btrfs_unlock_up_safe(p, level + 1); | |
1747 | ||
5f39d397 | 1748 | ret = bin_search(b, key, level, &slot); |
b4ce94de | 1749 | |
5f39d397 | 1750 | if (level != 0) { |
33c66f43 YZ |
1751 | int dec = 0; |
1752 | if (ret && slot > 0) { | |
1753 | dec = 1; | |
be0e5c09 | 1754 | slot -= 1; |
33c66f43 | 1755 | } |
be0e5c09 | 1756 | p->slots[level] = slot; |
33c66f43 | 1757 | err = setup_nodes_for_search(trans, root, p, b, level, |
bd681513 | 1758 | ins_len, &write_lock_level); |
33c66f43 | 1759 | if (err == -EAGAIN) |
c8c42864 | 1760 | goto again; |
33c66f43 YZ |
1761 | if (err) { |
1762 | ret = err; | |
c8c42864 | 1763 | goto done; |
33c66f43 | 1764 | } |
c8c42864 CM |
1765 | b = p->nodes[level]; |
1766 | slot = p->slots[level]; | |
b4ce94de | 1767 | |
bd681513 CM |
1768 | /* |
1769 | * slot 0 is special, if we change the key | |
1770 | * we have to update the parent pointer | |
1771 | * which means we must have a write lock | |
1772 | * on the parent | |
1773 | */ | |
1774 | if (slot == 0 && cow && | |
1775 | write_lock_level < level + 1) { | |
1776 | write_lock_level = level + 1; | |
1777 | btrfs_release_path(p); | |
1778 | goto again; | |
1779 | } | |
1780 | ||
f9efa9c7 CM |
1781 | unlock_up(p, level, lowest_unlock); |
1782 | ||
925baedd | 1783 | if (level == lowest_level) { |
33c66f43 YZ |
1784 | if (dec) |
1785 | p->slots[level]++; | |
5b21f2ed | 1786 | goto done; |
925baedd | 1787 | } |
ca7a79ad | 1788 | |
33c66f43 | 1789 | err = read_block_for_search(trans, root, p, |
c8c42864 | 1790 | &b, level, slot, key); |
33c66f43 | 1791 | if (err == -EAGAIN) |
c8c42864 | 1792 | goto again; |
33c66f43 YZ |
1793 | if (err) { |
1794 | ret = err; | |
76a05b35 | 1795 | goto done; |
33c66f43 | 1796 | } |
76a05b35 | 1797 | |
b4ce94de | 1798 | if (!p->skip_locking) { |
bd681513 CM |
1799 | level = btrfs_header_level(b); |
1800 | if (level <= write_lock_level) { | |
1801 | err = btrfs_try_tree_write_lock(b); | |
1802 | if (!err) { | |
1803 | btrfs_set_path_blocking(p); | |
1804 | btrfs_tree_lock(b); | |
1805 | btrfs_clear_path_blocking(p, b, | |
1806 | BTRFS_WRITE_LOCK); | |
1807 | } | |
1808 | p->locks[level] = BTRFS_WRITE_LOCK; | |
1809 | } else { | |
1810 | err = btrfs_try_tree_read_lock(b); | |
1811 | if (!err) { | |
1812 | btrfs_set_path_blocking(p); | |
1813 | btrfs_tree_read_lock(b); | |
1814 | btrfs_clear_path_blocking(p, b, | |
1815 | BTRFS_READ_LOCK); | |
1816 | } | |
1817 | p->locks[level] = BTRFS_READ_LOCK; | |
b4ce94de | 1818 | } |
bd681513 | 1819 | p->nodes[level] = b; |
b4ce94de | 1820 | } |
be0e5c09 CM |
1821 | } else { |
1822 | p->slots[level] = slot; | |
87b29b20 YZ |
1823 | if (ins_len > 0 && |
1824 | btrfs_leaf_free_space(root, b) < ins_len) { | |
bd681513 CM |
1825 | if (write_lock_level < 1) { |
1826 | write_lock_level = 1; | |
1827 | btrfs_release_path(p); | |
1828 | goto again; | |
1829 | } | |
1830 | ||
b4ce94de | 1831 | btrfs_set_path_blocking(p); |
33c66f43 YZ |
1832 | err = split_leaf(trans, root, key, |
1833 | p, ins_len, ret == 0); | |
bd681513 | 1834 | btrfs_clear_path_blocking(p, NULL, 0); |
b4ce94de | 1835 | |
33c66f43 YZ |
1836 | BUG_ON(err > 0); |
1837 | if (err) { | |
1838 | ret = err; | |
65b51a00 CM |
1839 | goto done; |
1840 | } | |
5c680ed6 | 1841 | } |
459931ec CM |
1842 | if (!p->search_for_split) |
1843 | unlock_up(p, level, lowest_unlock); | |
65b51a00 | 1844 | goto done; |
be0e5c09 CM |
1845 | } |
1846 | } | |
65b51a00 CM |
1847 | ret = 1; |
1848 | done: | |
b4ce94de CM |
1849 | /* |
1850 | * we don't really know what they plan on doing with the path | |
1851 | * from here on, so for now just mark it as blocking | |
1852 | */ | |
b9473439 CM |
1853 | if (!p->leave_spinning) |
1854 | btrfs_set_path_blocking(p); | |
76a05b35 | 1855 | if (ret < 0) |
b3b4aa74 | 1856 | btrfs_release_path(p); |
65b51a00 | 1857 | return ret; |
be0e5c09 CM |
1858 | } |
1859 | ||
74123bd7 CM |
1860 | /* |
1861 | * adjust the pointers going up the tree, starting at level | |
1862 | * making sure the right key of each node is points to 'key'. | |
1863 | * This is used after shifting pointers to the left, so it stops | |
1864 | * fixing up pointers when a given leaf/node is not in slot 0 of the | |
1865 | * higher levels | |
aa5d6bed CM |
1866 | * |
1867 | * If this fails to write a tree block, it returns -1, but continues | |
1868 | * fixing up the blocks in ram so the tree is consistent. | |
74123bd7 | 1869 | */ |
5f39d397 CM |
1870 | static int fixup_low_keys(struct btrfs_trans_handle *trans, |
1871 | struct btrfs_root *root, struct btrfs_path *path, | |
1872 | struct btrfs_disk_key *key, int level) | |
be0e5c09 CM |
1873 | { |
1874 | int i; | |
aa5d6bed | 1875 | int ret = 0; |
5f39d397 CM |
1876 | struct extent_buffer *t; |
1877 | ||
234b63a0 | 1878 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { |
be0e5c09 | 1879 | int tslot = path->slots[i]; |
eb60ceac | 1880 | if (!path->nodes[i]) |
be0e5c09 | 1881 | break; |
5f39d397 CM |
1882 | t = path->nodes[i]; |
1883 | btrfs_set_node_key(t, key, tslot); | |
d6025579 | 1884 | btrfs_mark_buffer_dirty(path->nodes[i]); |
be0e5c09 CM |
1885 | if (tslot != 0) |
1886 | break; | |
1887 | } | |
aa5d6bed | 1888 | return ret; |
be0e5c09 CM |
1889 | } |
1890 | ||
31840ae1 ZY |
1891 | /* |
1892 | * update item key. | |
1893 | * | |
1894 | * This function isn't completely safe. It's the caller's responsibility | |
1895 | * that the new key won't break the order | |
1896 | */ | |
1897 | int btrfs_set_item_key_safe(struct btrfs_trans_handle *trans, | |
1898 | struct btrfs_root *root, struct btrfs_path *path, | |
1899 | struct btrfs_key *new_key) | |
1900 | { | |
1901 | struct btrfs_disk_key disk_key; | |
1902 | struct extent_buffer *eb; | |
1903 | int slot; | |
1904 | ||
1905 | eb = path->nodes[0]; | |
1906 | slot = path->slots[0]; | |
1907 | if (slot > 0) { | |
1908 | btrfs_item_key(eb, &disk_key, slot - 1); | |
1909 | if (comp_keys(&disk_key, new_key) >= 0) | |
1910 | return -1; | |
1911 | } | |
1912 | if (slot < btrfs_header_nritems(eb) - 1) { | |
1913 | btrfs_item_key(eb, &disk_key, slot + 1); | |
1914 | if (comp_keys(&disk_key, new_key) <= 0) | |
1915 | return -1; | |
1916 | } | |
1917 | ||
1918 | btrfs_cpu_key_to_disk(&disk_key, new_key); | |
1919 | btrfs_set_item_key(eb, &disk_key, slot); | |
1920 | btrfs_mark_buffer_dirty(eb); | |
1921 | if (slot == 0) | |
1922 | fixup_low_keys(trans, root, path, &disk_key, 1); | |
1923 | return 0; | |
1924 | } | |
1925 | ||
74123bd7 CM |
1926 | /* |
1927 | * try to push data from one node into the next node left in the | |
79f95c82 | 1928 | * tree. |
aa5d6bed CM |
1929 | * |
1930 | * returns 0 if some ptrs were pushed left, < 0 if there was some horrible | |
1931 | * error, and > 0 if there was no room in the left hand block. | |
74123bd7 | 1932 | */ |
98ed5174 CM |
1933 | static int push_node_left(struct btrfs_trans_handle *trans, |
1934 | struct btrfs_root *root, struct extent_buffer *dst, | |
971a1f66 | 1935 | struct extent_buffer *src, int empty) |
be0e5c09 | 1936 | { |
be0e5c09 | 1937 | int push_items = 0; |
bb803951 CM |
1938 | int src_nritems; |
1939 | int dst_nritems; | |
aa5d6bed | 1940 | int ret = 0; |
be0e5c09 | 1941 | |
5f39d397 CM |
1942 | src_nritems = btrfs_header_nritems(src); |
1943 | dst_nritems = btrfs_header_nritems(dst); | |
123abc88 | 1944 | push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems; |
7bb86316 CM |
1945 | WARN_ON(btrfs_header_generation(src) != trans->transid); |
1946 | WARN_ON(btrfs_header_generation(dst) != trans->transid); | |
54aa1f4d | 1947 | |
bce4eae9 | 1948 | if (!empty && src_nritems <= 8) |
971a1f66 CM |
1949 | return 1; |
1950 | ||
d397712b | 1951 | if (push_items <= 0) |
be0e5c09 CM |
1952 | return 1; |
1953 | ||
bce4eae9 | 1954 | if (empty) { |
971a1f66 | 1955 | push_items = min(src_nritems, push_items); |
bce4eae9 CM |
1956 | if (push_items < src_nritems) { |
1957 | /* leave at least 8 pointers in the node if | |
1958 | * we aren't going to empty it | |
1959 | */ | |
1960 | if (src_nritems - push_items < 8) { | |
1961 | if (push_items <= 8) | |
1962 | return 1; | |
1963 | push_items -= 8; | |
1964 | } | |
1965 | } | |
1966 | } else | |
1967 | push_items = min(src_nritems - 8, push_items); | |
79f95c82 | 1968 | |
5f39d397 CM |
1969 | copy_extent_buffer(dst, src, |
1970 | btrfs_node_key_ptr_offset(dst_nritems), | |
1971 | btrfs_node_key_ptr_offset(0), | |
d397712b | 1972 | push_items * sizeof(struct btrfs_key_ptr)); |
5f39d397 | 1973 | |
bb803951 | 1974 | if (push_items < src_nritems) { |
5f39d397 CM |
1975 | memmove_extent_buffer(src, btrfs_node_key_ptr_offset(0), |
1976 | btrfs_node_key_ptr_offset(push_items), | |
1977 | (src_nritems - push_items) * | |
1978 | sizeof(struct btrfs_key_ptr)); | |
1979 | } | |
1980 | btrfs_set_header_nritems(src, src_nritems - push_items); | |
1981 | btrfs_set_header_nritems(dst, dst_nritems + push_items); | |
1982 | btrfs_mark_buffer_dirty(src); | |
1983 | btrfs_mark_buffer_dirty(dst); | |
31840ae1 | 1984 | |
79f95c82 CM |
1985 | return ret; |
1986 | } | |
1987 | ||
1988 | /* | |
1989 | * try to push data from one node into the next node right in the | |
1990 | * tree. | |
1991 | * | |
1992 | * returns 0 if some ptrs were pushed, < 0 if there was some horrible | |
1993 | * error, and > 0 if there was no room in the right hand block. | |
1994 | * | |
1995 | * this will only push up to 1/2 the contents of the left node over | |
1996 | */ | |
5f39d397 CM |
1997 | static int balance_node_right(struct btrfs_trans_handle *trans, |
1998 | struct btrfs_root *root, | |
1999 | struct extent_buffer *dst, | |
2000 | struct extent_buffer *src) | |
79f95c82 | 2001 | { |
79f95c82 CM |
2002 | int push_items = 0; |
2003 | int max_push; | |
2004 | int src_nritems; | |
2005 | int dst_nritems; | |
2006 | int ret = 0; | |
79f95c82 | 2007 | |
7bb86316 CM |
2008 | WARN_ON(btrfs_header_generation(src) != trans->transid); |
2009 | WARN_ON(btrfs_header_generation(dst) != trans->transid); | |
2010 | ||
5f39d397 CM |
2011 | src_nritems = btrfs_header_nritems(src); |
2012 | dst_nritems = btrfs_header_nritems(dst); | |
123abc88 | 2013 | push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems; |
d397712b | 2014 | if (push_items <= 0) |
79f95c82 | 2015 | return 1; |
bce4eae9 | 2016 | |
d397712b | 2017 | if (src_nritems < 4) |
bce4eae9 | 2018 | return 1; |
79f95c82 CM |
2019 | |
2020 | max_push = src_nritems / 2 + 1; | |
2021 | /* don't try to empty the node */ | |
d397712b | 2022 | if (max_push >= src_nritems) |
79f95c82 | 2023 | return 1; |
252c38f0 | 2024 | |
79f95c82 CM |
2025 | if (max_push < push_items) |
2026 | push_items = max_push; | |
2027 | ||
5f39d397 CM |
2028 | memmove_extent_buffer(dst, btrfs_node_key_ptr_offset(push_items), |
2029 | btrfs_node_key_ptr_offset(0), | |
2030 | (dst_nritems) * | |
2031 | sizeof(struct btrfs_key_ptr)); | |
d6025579 | 2032 | |
5f39d397 CM |
2033 | copy_extent_buffer(dst, src, |
2034 | btrfs_node_key_ptr_offset(0), | |
2035 | btrfs_node_key_ptr_offset(src_nritems - push_items), | |
d397712b | 2036 | push_items * sizeof(struct btrfs_key_ptr)); |
79f95c82 | 2037 | |
5f39d397 CM |
2038 | btrfs_set_header_nritems(src, src_nritems - push_items); |
2039 | btrfs_set_header_nritems(dst, dst_nritems + push_items); | |
79f95c82 | 2040 | |
5f39d397 CM |
2041 | btrfs_mark_buffer_dirty(src); |
2042 | btrfs_mark_buffer_dirty(dst); | |
31840ae1 | 2043 | |
aa5d6bed | 2044 | return ret; |
be0e5c09 CM |
2045 | } |
2046 | ||
97571fd0 CM |
2047 | /* |
2048 | * helper function to insert a new root level in the tree. | |
2049 | * A new node is allocated, and a single item is inserted to | |
2050 | * point to the existing root | |
aa5d6bed CM |
2051 | * |
2052 | * returns zero on success or < 0 on failure. | |
97571fd0 | 2053 | */ |
d397712b | 2054 | static noinline int insert_new_root(struct btrfs_trans_handle *trans, |
5f39d397 CM |
2055 | struct btrfs_root *root, |
2056 | struct btrfs_path *path, int level) | |
5c680ed6 | 2057 | { |
7bb86316 | 2058 | u64 lower_gen; |
5f39d397 CM |
2059 | struct extent_buffer *lower; |
2060 | struct extent_buffer *c; | |
925baedd | 2061 | struct extent_buffer *old; |
5f39d397 | 2062 | struct btrfs_disk_key lower_key; |
5c680ed6 CM |
2063 | |
2064 | BUG_ON(path->nodes[level]); | |
2065 | BUG_ON(path->nodes[level-1] != root->node); | |
2066 | ||
7bb86316 CM |
2067 | lower = path->nodes[level-1]; |
2068 | if (level == 1) | |
2069 | btrfs_item_key(lower, &lower_key, 0); | |
2070 | else | |
2071 | btrfs_node_key(lower, &lower_key, 0); | |
2072 | ||
31840ae1 | 2073 | c = btrfs_alloc_free_block(trans, root, root->nodesize, 0, |
5d4f98a2 | 2074 | root->root_key.objectid, &lower_key, |
ad3d81ba | 2075 | level, root->node->start, 0); |
5f39d397 CM |
2076 | if (IS_ERR(c)) |
2077 | return PTR_ERR(c); | |
925baedd | 2078 | |
f0486c68 YZ |
2079 | root_add_used(root, root->nodesize); |
2080 | ||
5d4f98a2 | 2081 | memset_extent_buffer(c, 0, 0, sizeof(struct btrfs_header)); |
5f39d397 CM |
2082 | btrfs_set_header_nritems(c, 1); |
2083 | btrfs_set_header_level(c, level); | |
db94535d | 2084 | btrfs_set_header_bytenr(c, c->start); |
5f39d397 | 2085 | btrfs_set_header_generation(c, trans->transid); |
5d4f98a2 | 2086 | btrfs_set_header_backref_rev(c, BTRFS_MIXED_BACKREF_REV); |
5f39d397 | 2087 | btrfs_set_header_owner(c, root->root_key.objectid); |
5f39d397 CM |
2088 | |
2089 | write_extent_buffer(c, root->fs_info->fsid, | |
2090 | (unsigned long)btrfs_header_fsid(c), | |
2091 | BTRFS_FSID_SIZE); | |
e17cade2 CM |
2092 | |
2093 | write_extent_buffer(c, root->fs_info->chunk_tree_uuid, | |
2094 | (unsigned long)btrfs_header_chunk_tree_uuid(c), | |
2095 | BTRFS_UUID_SIZE); | |
2096 | ||
5f39d397 | 2097 | btrfs_set_node_key(c, &lower_key, 0); |
db94535d | 2098 | btrfs_set_node_blockptr(c, 0, lower->start); |
7bb86316 | 2099 | lower_gen = btrfs_header_generation(lower); |
31840ae1 | 2100 | WARN_ON(lower_gen != trans->transid); |
7bb86316 CM |
2101 | |
2102 | btrfs_set_node_ptr_generation(c, 0, lower_gen); | |
d5719762 | 2103 | |
5f39d397 | 2104 | btrfs_mark_buffer_dirty(c); |
d5719762 | 2105 | |
925baedd | 2106 | old = root->node; |
240f62c8 | 2107 | rcu_assign_pointer(root->node, c); |
925baedd CM |
2108 | |
2109 | /* the super has an extra ref to root->node */ | |
2110 | free_extent_buffer(old); | |
2111 | ||
0b86a832 | 2112 | add_root_to_dirty_list(root); |
5f39d397 CM |
2113 | extent_buffer_get(c); |
2114 | path->nodes[level] = c; | |
bd681513 | 2115 | path->locks[level] = BTRFS_WRITE_LOCK; |
5c680ed6 CM |
2116 | path->slots[level] = 0; |
2117 | return 0; | |
2118 | } | |
2119 | ||
74123bd7 CM |
2120 | /* |
2121 | * worker function to insert a single pointer in a node. | |
2122 | * the node should have enough room for the pointer already | |
97571fd0 | 2123 | * |
74123bd7 CM |
2124 | * slot and level indicate where you want the key to go, and |
2125 | * blocknr is the block the key points to. | |
aa5d6bed CM |
2126 | * |
2127 | * returns zero on success and < 0 on any error | |
74123bd7 | 2128 | */ |
e089f05c CM |
2129 | static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root |
2130 | *root, struct btrfs_path *path, struct btrfs_disk_key | |
db94535d | 2131 | *key, u64 bytenr, int slot, int level) |
74123bd7 | 2132 | { |
5f39d397 | 2133 | struct extent_buffer *lower; |
74123bd7 | 2134 | int nritems; |
5c680ed6 CM |
2135 | |
2136 | BUG_ON(!path->nodes[level]); | |
f0486c68 | 2137 | btrfs_assert_tree_locked(path->nodes[level]); |
5f39d397 CM |
2138 | lower = path->nodes[level]; |
2139 | nritems = btrfs_header_nritems(lower); | |
c293498b | 2140 | BUG_ON(slot > nritems); |
123abc88 | 2141 | if (nritems == BTRFS_NODEPTRS_PER_BLOCK(root)) |
74123bd7 CM |
2142 | BUG(); |
2143 | if (slot != nritems) { | |
5f39d397 CM |
2144 | memmove_extent_buffer(lower, |
2145 | btrfs_node_key_ptr_offset(slot + 1), | |
2146 | btrfs_node_key_ptr_offset(slot), | |
d6025579 | 2147 | (nritems - slot) * sizeof(struct btrfs_key_ptr)); |
74123bd7 | 2148 | } |
5f39d397 | 2149 | btrfs_set_node_key(lower, key, slot); |
db94535d | 2150 | btrfs_set_node_blockptr(lower, slot, bytenr); |
74493f7a CM |
2151 | WARN_ON(trans->transid == 0); |
2152 | btrfs_set_node_ptr_generation(lower, slot, trans->transid); | |
5f39d397 CM |
2153 | btrfs_set_header_nritems(lower, nritems + 1); |
2154 | btrfs_mark_buffer_dirty(lower); | |
74123bd7 CM |
2155 | return 0; |
2156 | } | |
2157 | ||
97571fd0 CM |
2158 | /* |
2159 | * split the node at the specified level in path in two. | |
2160 | * The path is corrected to point to the appropriate node after the split | |
2161 | * | |
2162 | * Before splitting this tries to make some room in the node by pushing | |
2163 | * left and right, if either one works, it returns right away. | |
aa5d6bed CM |
2164 | * |
2165 | * returns 0 on success and < 0 on failure | |
97571fd0 | 2166 | */ |
e02119d5 CM |
2167 | static noinline int split_node(struct btrfs_trans_handle *trans, |
2168 | struct btrfs_root *root, | |
2169 | struct btrfs_path *path, int level) | |
be0e5c09 | 2170 | { |
5f39d397 CM |
2171 | struct extent_buffer *c; |
2172 | struct extent_buffer *split; | |
2173 | struct btrfs_disk_key disk_key; | |
be0e5c09 | 2174 | int mid; |
5c680ed6 | 2175 | int ret; |
aa5d6bed | 2176 | int wret; |
7518a238 | 2177 | u32 c_nritems; |
eb60ceac | 2178 | |
5f39d397 | 2179 | c = path->nodes[level]; |
7bb86316 | 2180 | WARN_ON(btrfs_header_generation(c) != trans->transid); |
5f39d397 | 2181 | if (c == root->node) { |
5c680ed6 | 2182 | /* trying to split the root, lets make a new one */ |
e089f05c | 2183 | ret = insert_new_root(trans, root, path, level + 1); |
5c680ed6 CM |
2184 | if (ret) |
2185 | return ret; | |
b3612421 | 2186 | } else { |
e66f709b | 2187 | ret = push_nodes_for_insert(trans, root, path, level); |
5f39d397 CM |
2188 | c = path->nodes[level]; |
2189 | if (!ret && btrfs_header_nritems(c) < | |
c448acf0 | 2190 | BTRFS_NODEPTRS_PER_BLOCK(root) - 3) |
e66f709b | 2191 | return 0; |
54aa1f4d CM |
2192 | if (ret < 0) |
2193 | return ret; | |
be0e5c09 | 2194 | } |
e66f709b | 2195 | |
5f39d397 | 2196 | c_nritems = btrfs_header_nritems(c); |
5d4f98a2 YZ |
2197 | mid = (c_nritems + 1) / 2; |
2198 | btrfs_node_key(c, &disk_key, mid); | |
7bb86316 | 2199 | |
5d4f98a2 | 2200 | split = btrfs_alloc_free_block(trans, root, root->nodesize, 0, |
31840ae1 | 2201 | root->root_key.objectid, |
5d4f98a2 | 2202 | &disk_key, level, c->start, 0); |
5f39d397 CM |
2203 | if (IS_ERR(split)) |
2204 | return PTR_ERR(split); | |
2205 | ||
f0486c68 YZ |
2206 | root_add_used(root, root->nodesize); |
2207 | ||
5d4f98a2 | 2208 | memset_extent_buffer(split, 0, 0, sizeof(struct btrfs_header)); |
5f39d397 | 2209 | btrfs_set_header_level(split, btrfs_header_level(c)); |
db94535d | 2210 | btrfs_set_header_bytenr(split, split->start); |
5f39d397 | 2211 | btrfs_set_header_generation(split, trans->transid); |
5d4f98a2 | 2212 | btrfs_set_header_backref_rev(split, BTRFS_MIXED_BACKREF_REV); |
5f39d397 CM |
2213 | btrfs_set_header_owner(split, root->root_key.objectid); |
2214 | write_extent_buffer(split, root->fs_info->fsid, | |
2215 | (unsigned long)btrfs_header_fsid(split), | |
2216 | BTRFS_FSID_SIZE); | |
e17cade2 CM |
2217 | write_extent_buffer(split, root->fs_info->chunk_tree_uuid, |
2218 | (unsigned long)btrfs_header_chunk_tree_uuid(split), | |
2219 | BTRFS_UUID_SIZE); | |
54aa1f4d | 2220 | |
5f39d397 CM |
2221 | |
2222 | copy_extent_buffer(split, c, | |
2223 | btrfs_node_key_ptr_offset(0), | |
2224 | btrfs_node_key_ptr_offset(mid), | |
2225 | (c_nritems - mid) * sizeof(struct btrfs_key_ptr)); | |
2226 | btrfs_set_header_nritems(split, c_nritems - mid); | |
2227 | btrfs_set_header_nritems(c, mid); | |
aa5d6bed CM |
2228 | ret = 0; |
2229 | ||
5f39d397 CM |
2230 | btrfs_mark_buffer_dirty(c); |
2231 | btrfs_mark_buffer_dirty(split); | |
2232 | ||
db94535d | 2233 | wret = insert_ptr(trans, root, path, &disk_key, split->start, |
5f39d397 | 2234 | path->slots[level + 1] + 1, |
123abc88 | 2235 | level + 1); |
aa5d6bed CM |
2236 | if (wret) |
2237 | ret = wret; | |
2238 | ||
5de08d7d | 2239 | if (path->slots[level] >= mid) { |
5c680ed6 | 2240 | path->slots[level] -= mid; |
925baedd | 2241 | btrfs_tree_unlock(c); |
5f39d397 CM |
2242 | free_extent_buffer(c); |
2243 | path->nodes[level] = split; | |
5c680ed6 CM |
2244 | path->slots[level + 1] += 1; |
2245 | } else { | |
925baedd | 2246 | btrfs_tree_unlock(split); |
5f39d397 | 2247 | free_extent_buffer(split); |
be0e5c09 | 2248 | } |
aa5d6bed | 2249 | return ret; |
be0e5c09 CM |
2250 | } |
2251 | ||
74123bd7 CM |
2252 | /* |
2253 | * how many bytes are required to store the items in a leaf. start | |
2254 | * and nr indicate which items in the leaf to check. This totals up the | |
2255 | * space used both by the item structs and the item data | |
2256 | */ | |
5f39d397 | 2257 | static int leaf_space_used(struct extent_buffer *l, int start, int nr) |
be0e5c09 CM |
2258 | { |
2259 | int data_len; | |
5f39d397 | 2260 | int nritems = btrfs_header_nritems(l); |
d4dbff95 | 2261 | int end = min(nritems, start + nr) - 1; |
be0e5c09 CM |
2262 | |
2263 | if (!nr) | |
2264 | return 0; | |
5f39d397 CM |
2265 | data_len = btrfs_item_end_nr(l, start); |
2266 | data_len = data_len - btrfs_item_offset_nr(l, end); | |
0783fcfc | 2267 | data_len += sizeof(struct btrfs_item) * nr; |
d4dbff95 | 2268 | WARN_ON(data_len < 0); |
be0e5c09 CM |
2269 | return data_len; |
2270 | } | |
2271 | ||
d4dbff95 CM |
2272 | /* |
2273 | * The space between the end of the leaf items and | |
2274 | * the start of the leaf data. IOW, how much room | |
2275 | * the leaf has left for both items and data | |
2276 | */ | |
d397712b | 2277 | noinline int btrfs_leaf_free_space(struct btrfs_root *root, |
e02119d5 | 2278 | struct extent_buffer *leaf) |
d4dbff95 | 2279 | { |
5f39d397 CM |
2280 | int nritems = btrfs_header_nritems(leaf); |
2281 | int ret; | |
2282 | ret = BTRFS_LEAF_DATA_SIZE(root) - leaf_space_used(leaf, 0, nritems); | |
2283 | if (ret < 0) { | |
d397712b CM |
2284 | printk(KERN_CRIT "leaf free space ret %d, leaf data size %lu, " |
2285 | "used %d nritems %d\n", | |
ae2f5411 | 2286 | ret, (unsigned long) BTRFS_LEAF_DATA_SIZE(root), |
5f39d397 CM |
2287 | leaf_space_used(leaf, 0, nritems), nritems); |
2288 | } | |
2289 | return ret; | |
d4dbff95 CM |
2290 | } |
2291 | ||
99d8f83c CM |
2292 | /* |
2293 | * min slot controls the lowest index we're willing to push to the | |
2294 | * right. We'll push up to and including min_slot, but no lower | |
2295 | */ | |
44871b1b CM |
2296 | static noinline int __push_leaf_right(struct btrfs_trans_handle *trans, |
2297 | struct btrfs_root *root, | |
2298 | struct btrfs_path *path, | |
2299 | int data_size, int empty, | |
2300 | struct extent_buffer *right, | |
99d8f83c CM |
2301 | int free_space, u32 left_nritems, |
2302 | u32 min_slot) | |
00ec4c51 | 2303 | { |
5f39d397 | 2304 | struct extent_buffer *left = path->nodes[0]; |
44871b1b | 2305 | struct extent_buffer *upper = path->nodes[1]; |
5f39d397 | 2306 | struct btrfs_disk_key disk_key; |
00ec4c51 | 2307 | int slot; |
34a38218 | 2308 | u32 i; |
00ec4c51 CM |
2309 | int push_space = 0; |
2310 | int push_items = 0; | |
0783fcfc | 2311 | struct btrfs_item *item; |
34a38218 | 2312 | u32 nr; |
7518a238 | 2313 | u32 right_nritems; |
5f39d397 | 2314 | u32 data_end; |
db94535d | 2315 | u32 this_item_size; |
00ec4c51 | 2316 | |
34a38218 CM |
2317 | if (empty) |
2318 | nr = 0; | |
2319 | else | |
99d8f83c | 2320 | nr = max_t(u32, 1, min_slot); |
34a38218 | 2321 | |
31840ae1 | 2322 | if (path->slots[0] >= left_nritems) |
87b29b20 | 2323 | push_space += data_size; |
31840ae1 | 2324 | |
44871b1b | 2325 | slot = path->slots[1]; |
34a38218 CM |
2326 | i = left_nritems - 1; |
2327 | while (i >= nr) { | |
5f39d397 | 2328 | item = btrfs_item_nr(left, i); |
db94535d | 2329 | |
31840ae1 ZY |
2330 | if (!empty && push_items > 0) { |
2331 | if (path->slots[0] > i) | |
2332 | break; | |
2333 | if (path->slots[0] == i) { | |
2334 | int space = btrfs_leaf_free_space(root, left); | |
2335 | if (space + push_space * 2 > free_space) | |
2336 | break; | |
2337 | } | |
2338 | } | |
2339 | ||
00ec4c51 | 2340 | if (path->slots[0] == i) |
87b29b20 | 2341 | push_space += data_size; |
db94535d | 2342 | |
db94535d CM |
2343 | this_item_size = btrfs_item_size(left, item); |
2344 | if (this_item_size + sizeof(*item) + push_space > free_space) | |
00ec4c51 | 2345 | break; |
31840ae1 | 2346 | |
00ec4c51 | 2347 | push_items++; |
db94535d | 2348 | push_space += this_item_size + sizeof(*item); |
34a38218 CM |
2349 | if (i == 0) |
2350 | break; | |
2351 | i--; | |
db94535d | 2352 | } |
5f39d397 | 2353 | |
925baedd CM |
2354 | if (push_items == 0) |
2355 | goto out_unlock; | |
5f39d397 | 2356 | |
34a38218 | 2357 | if (!empty && push_items == left_nritems) |
a429e513 | 2358 | WARN_ON(1); |
5f39d397 | 2359 | |
00ec4c51 | 2360 | /* push left to right */ |
5f39d397 | 2361 | right_nritems = btrfs_header_nritems(right); |
34a38218 | 2362 | |
5f39d397 | 2363 | push_space = btrfs_item_end_nr(left, left_nritems - push_items); |
123abc88 | 2364 | push_space -= leaf_data_end(root, left); |
5f39d397 | 2365 | |
00ec4c51 | 2366 | /* make room in the right data area */ |
5f39d397 CM |
2367 | data_end = leaf_data_end(root, right); |
2368 | memmove_extent_buffer(right, | |
2369 | btrfs_leaf_data(right) + data_end - push_space, | |
2370 | btrfs_leaf_data(right) + data_end, | |
2371 | BTRFS_LEAF_DATA_SIZE(root) - data_end); | |
2372 | ||
00ec4c51 | 2373 | /* copy from the left data area */ |
5f39d397 | 2374 | copy_extent_buffer(right, left, btrfs_leaf_data(right) + |
d6025579 CM |
2375 | BTRFS_LEAF_DATA_SIZE(root) - push_space, |
2376 | btrfs_leaf_data(left) + leaf_data_end(root, left), | |
2377 | push_space); | |
5f39d397 CM |
2378 | |
2379 | memmove_extent_buffer(right, btrfs_item_nr_offset(push_items), | |
2380 | btrfs_item_nr_offset(0), | |
2381 | right_nritems * sizeof(struct btrfs_item)); | |
2382 | ||
00ec4c51 | 2383 | /* copy the items from left to right */ |
5f39d397 CM |
2384 | copy_extent_buffer(right, left, btrfs_item_nr_offset(0), |
2385 | btrfs_item_nr_offset(left_nritems - push_items), | |
2386 | push_items * sizeof(struct btrfs_item)); | |
00ec4c51 CM |
2387 | |
2388 | /* update the item pointers */ | |
7518a238 | 2389 | right_nritems += push_items; |
5f39d397 | 2390 | btrfs_set_header_nritems(right, right_nritems); |
123abc88 | 2391 | push_space = BTRFS_LEAF_DATA_SIZE(root); |
7518a238 | 2392 | for (i = 0; i < right_nritems; i++) { |
5f39d397 | 2393 | item = btrfs_item_nr(right, i); |
db94535d CM |
2394 | push_space -= btrfs_item_size(right, item); |
2395 | btrfs_set_item_offset(right, item, push_space); | |
2396 | } | |
2397 | ||
7518a238 | 2398 | left_nritems -= push_items; |
5f39d397 | 2399 | btrfs_set_header_nritems(left, left_nritems); |
00ec4c51 | 2400 | |
34a38218 CM |
2401 | if (left_nritems) |
2402 | btrfs_mark_buffer_dirty(left); | |
f0486c68 YZ |
2403 | else |
2404 | clean_tree_block(trans, root, left); | |
2405 | ||
5f39d397 | 2406 | btrfs_mark_buffer_dirty(right); |
a429e513 | 2407 | |
5f39d397 CM |
2408 | btrfs_item_key(right, &disk_key, 0); |
2409 | btrfs_set_node_key(upper, &disk_key, slot + 1); | |
d6025579 | 2410 | btrfs_mark_buffer_dirty(upper); |
02217ed2 | 2411 | |
00ec4c51 | 2412 | /* then fixup the leaf pointer in the path */ |
7518a238 CM |
2413 | if (path->slots[0] >= left_nritems) { |
2414 | path->slots[0] -= left_nritems; | |
925baedd CM |
2415 | if (btrfs_header_nritems(path->nodes[0]) == 0) |
2416 | clean_tree_block(trans, root, path->nodes[0]); | |
2417 | btrfs_tree_unlock(path->nodes[0]); | |
5f39d397 CM |
2418 | free_extent_buffer(path->nodes[0]); |
2419 | path->nodes[0] = right; | |
00ec4c51 CM |
2420 | path->slots[1] += 1; |
2421 | } else { | |
925baedd | 2422 | btrfs_tree_unlock(right); |
5f39d397 | 2423 | free_extent_buffer(right); |
00ec4c51 CM |
2424 | } |
2425 | return 0; | |
925baedd CM |
2426 | |
2427 | out_unlock: | |
2428 | btrfs_tree_unlock(right); | |
2429 | free_extent_buffer(right); | |
2430 | return 1; | |
00ec4c51 | 2431 | } |
925baedd | 2432 | |
44871b1b CM |
2433 | /* |
2434 | * push some data in the path leaf to the right, trying to free up at | |
2435 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
2436 | * | |
2437 | * returns 1 if the push failed because the other node didn't have enough | |
2438 | * room, 0 if everything worked out and < 0 if there were major errors. | |
99d8f83c CM |
2439 | * |
2440 | * this will push starting from min_slot to the end of the leaf. It won't | |
2441 | * push any slot lower than min_slot | |
44871b1b CM |
2442 | */ |
2443 | static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root | |
99d8f83c CM |
2444 | *root, struct btrfs_path *path, |
2445 | int min_data_size, int data_size, | |
2446 | int empty, u32 min_slot) | |
44871b1b CM |
2447 | { |
2448 | struct extent_buffer *left = path->nodes[0]; | |
2449 | struct extent_buffer *right; | |
2450 | struct extent_buffer *upper; | |
2451 | int slot; | |
2452 | int free_space; | |
2453 | u32 left_nritems; | |
2454 | int ret; | |
2455 | ||
2456 | if (!path->nodes[1]) | |
2457 | return 1; | |
2458 | ||
2459 | slot = path->slots[1]; | |
2460 | upper = path->nodes[1]; | |
2461 | if (slot >= btrfs_header_nritems(upper) - 1) | |
2462 | return 1; | |
2463 | ||
2464 | btrfs_assert_tree_locked(path->nodes[1]); | |
2465 | ||
2466 | right = read_node_slot(root, upper, slot + 1); | |
91ca338d TI |
2467 | if (right == NULL) |
2468 | return 1; | |
2469 | ||
44871b1b CM |
2470 | btrfs_tree_lock(right); |
2471 | btrfs_set_lock_blocking(right); | |
2472 | ||
2473 | free_space = btrfs_leaf_free_space(root, right); | |
2474 | if (free_space < data_size) | |
2475 | goto out_unlock; | |
2476 | ||
2477 | /* cow and double check */ | |
2478 | ret = btrfs_cow_block(trans, root, right, upper, | |
2479 | slot + 1, &right); | |
2480 | if (ret) | |
2481 | goto out_unlock; | |
2482 | ||
2483 | free_space = btrfs_leaf_free_space(root, right); | |
2484 | if (free_space < data_size) | |
2485 | goto out_unlock; | |
2486 | ||
2487 | left_nritems = btrfs_header_nritems(left); | |
2488 | if (left_nritems == 0) | |
2489 | goto out_unlock; | |
2490 | ||
99d8f83c CM |
2491 | return __push_leaf_right(trans, root, path, min_data_size, empty, |
2492 | right, free_space, left_nritems, min_slot); | |
44871b1b CM |
2493 | out_unlock: |
2494 | btrfs_tree_unlock(right); | |
2495 | free_extent_buffer(right); | |
2496 | return 1; | |
2497 | } | |
2498 | ||
74123bd7 CM |
2499 | /* |
2500 | * push some data in the path leaf to the left, trying to free up at | |
2501 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
99d8f83c CM |
2502 | * |
2503 | * max_slot can put a limit on how far into the leaf we'll push items. The | |
2504 | * item at 'max_slot' won't be touched. Use (u32)-1 to make us do all the | |
2505 | * items | |
74123bd7 | 2506 | */ |
44871b1b CM |
2507 | static noinline int __push_leaf_left(struct btrfs_trans_handle *trans, |
2508 | struct btrfs_root *root, | |
2509 | struct btrfs_path *path, int data_size, | |
2510 | int empty, struct extent_buffer *left, | |
99d8f83c CM |
2511 | int free_space, u32 right_nritems, |
2512 | u32 max_slot) | |
be0e5c09 | 2513 | { |
5f39d397 CM |
2514 | struct btrfs_disk_key disk_key; |
2515 | struct extent_buffer *right = path->nodes[0]; | |
be0e5c09 | 2516 | int i; |
be0e5c09 CM |
2517 | int push_space = 0; |
2518 | int push_items = 0; | |
0783fcfc | 2519 | struct btrfs_item *item; |
7518a238 | 2520 | u32 old_left_nritems; |
34a38218 | 2521 | u32 nr; |
aa5d6bed CM |
2522 | int ret = 0; |
2523 | int wret; | |
db94535d CM |
2524 | u32 this_item_size; |
2525 | u32 old_left_item_size; | |
be0e5c09 | 2526 | |
34a38218 | 2527 | if (empty) |
99d8f83c | 2528 | nr = min(right_nritems, max_slot); |
34a38218 | 2529 | else |
99d8f83c | 2530 | nr = min(right_nritems - 1, max_slot); |
34a38218 CM |
2531 | |
2532 | for (i = 0; i < nr; i++) { | |
5f39d397 | 2533 | item = btrfs_item_nr(right, i); |
db94535d | 2534 | |
31840ae1 ZY |
2535 | if (!empty && push_items > 0) { |
2536 | if (path->slots[0] < i) | |
2537 | break; | |
2538 | if (path->slots[0] == i) { | |
2539 | int space = btrfs_leaf_free_space(root, right); | |
2540 | if (space + push_space * 2 > free_space) | |
2541 | break; | |
2542 | } | |
2543 | } | |
2544 | ||
be0e5c09 | 2545 | if (path->slots[0] == i) |
87b29b20 | 2546 | push_space += data_size; |
db94535d CM |
2547 | |
2548 | this_item_size = btrfs_item_size(right, item); | |
2549 | if (this_item_size + sizeof(*item) + push_space > free_space) | |
be0e5c09 | 2550 | break; |
db94535d | 2551 | |
be0e5c09 | 2552 | push_items++; |
db94535d CM |
2553 | push_space += this_item_size + sizeof(*item); |
2554 | } | |
2555 | ||
be0e5c09 | 2556 | if (push_items == 0) { |
925baedd CM |
2557 | ret = 1; |
2558 | goto out; | |
be0e5c09 | 2559 | } |
34a38218 | 2560 | if (!empty && push_items == btrfs_header_nritems(right)) |
a429e513 | 2561 | WARN_ON(1); |
5f39d397 | 2562 | |
be0e5c09 | 2563 | /* push data from right to left */ |
5f39d397 CM |
2564 | copy_extent_buffer(left, right, |
2565 | btrfs_item_nr_offset(btrfs_header_nritems(left)), | |
2566 | btrfs_item_nr_offset(0), | |
2567 | push_items * sizeof(struct btrfs_item)); | |
2568 | ||
123abc88 | 2569 | push_space = BTRFS_LEAF_DATA_SIZE(root) - |
d397712b | 2570 | btrfs_item_offset_nr(right, push_items - 1); |
5f39d397 CM |
2571 | |
2572 | copy_extent_buffer(left, right, btrfs_leaf_data(left) + | |
d6025579 CM |
2573 | leaf_data_end(root, left) - push_space, |
2574 | btrfs_leaf_data(right) + | |
5f39d397 | 2575 | btrfs_item_offset_nr(right, push_items - 1), |
d6025579 | 2576 | push_space); |
5f39d397 | 2577 | old_left_nritems = btrfs_header_nritems(left); |
87b29b20 | 2578 | BUG_ON(old_left_nritems <= 0); |
eb60ceac | 2579 | |
db94535d | 2580 | old_left_item_size = btrfs_item_offset_nr(left, old_left_nritems - 1); |
0783fcfc | 2581 | for (i = old_left_nritems; i < old_left_nritems + push_items; i++) { |
5f39d397 | 2582 | u32 ioff; |
db94535d | 2583 | |
5f39d397 | 2584 | item = btrfs_item_nr(left, i); |
db94535d | 2585 | |
5f39d397 CM |
2586 | ioff = btrfs_item_offset(left, item); |
2587 | btrfs_set_item_offset(left, item, | |
db94535d | 2588 | ioff - (BTRFS_LEAF_DATA_SIZE(root) - old_left_item_size)); |
be0e5c09 | 2589 | } |
5f39d397 | 2590 | btrfs_set_header_nritems(left, old_left_nritems + push_items); |
be0e5c09 CM |
2591 | |
2592 | /* fixup right node */ | |
34a38218 | 2593 | if (push_items > right_nritems) { |
d397712b CM |
2594 | printk(KERN_CRIT "push items %d nr %u\n", push_items, |
2595 | right_nritems); | |
34a38218 CM |
2596 | WARN_ON(1); |
2597 | } | |
2598 | ||
2599 | if (push_items < right_nritems) { | |
2600 | push_space = btrfs_item_offset_nr(right, push_items - 1) - | |
2601 | leaf_data_end(root, right); | |
2602 | memmove_extent_buffer(right, btrfs_leaf_data(right) + | |
2603 | BTRFS_LEAF_DATA_SIZE(root) - push_space, | |
2604 | btrfs_leaf_data(right) + | |
2605 | leaf_data_end(root, right), push_space); | |
2606 | ||
2607 | memmove_extent_buffer(right, btrfs_item_nr_offset(0), | |
5f39d397 CM |
2608 | btrfs_item_nr_offset(push_items), |
2609 | (btrfs_header_nritems(right) - push_items) * | |
2610 | sizeof(struct btrfs_item)); | |
34a38218 | 2611 | } |
eef1c494 Y |
2612 | right_nritems -= push_items; |
2613 | btrfs_set_header_nritems(right, right_nritems); | |
123abc88 | 2614 | push_space = BTRFS_LEAF_DATA_SIZE(root); |
5f39d397 CM |
2615 | for (i = 0; i < right_nritems; i++) { |
2616 | item = btrfs_item_nr(right, i); | |
db94535d | 2617 | |
db94535d CM |
2618 | push_space = push_space - btrfs_item_size(right, item); |
2619 | btrfs_set_item_offset(right, item, push_space); | |
2620 | } | |
eb60ceac | 2621 | |
5f39d397 | 2622 | btrfs_mark_buffer_dirty(left); |
34a38218 CM |
2623 | if (right_nritems) |
2624 | btrfs_mark_buffer_dirty(right); | |
f0486c68 YZ |
2625 | else |
2626 | clean_tree_block(trans, root, right); | |
098f59c2 | 2627 | |
5f39d397 CM |
2628 | btrfs_item_key(right, &disk_key, 0); |
2629 | wret = fixup_low_keys(trans, root, path, &disk_key, 1); | |
aa5d6bed CM |
2630 | if (wret) |
2631 | ret = wret; | |
be0e5c09 CM |
2632 | |
2633 | /* then fixup the leaf pointer in the path */ | |
2634 | if (path->slots[0] < push_items) { | |
2635 | path->slots[0] += old_left_nritems; | |
925baedd | 2636 | btrfs_tree_unlock(path->nodes[0]); |
5f39d397 CM |
2637 | free_extent_buffer(path->nodes[0]); |
2638 | path->nodes[0] = left; | |
be0e5c09 CM |
2639 | path->slots[1] -= 1; |
2640 | } else { | |
925baedd | 2641 | btrfs_tree_unlock(left); |
5f39d397 | 2642 | free_extent_buffer(left); |
be0e5c09 CM |
2643 | path->slots[0] -= push_items; |
2644 | } | |
eb60ceac | 2645 | BUG_ON(path->slots[0] < 0); |
aa5d6bed | 2646 | return ret; |
925baedd CM |
2647 | out: |
2648 | btrfs_tree_unlock(left); | |
2649 | free_extent_buffer(left); | |
2650 | return ret; | |
be0e5c09 CM |
2651 | } |
2652 | ||
44871b1b CM |
2653 | /* |
2654 | * push some data in the path leaf to the left, trying to free up at | |
2655 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
99d8f83c CM |
2656 | * |
2657 | * max_slot can put a limit on how far into the leaf we'll push items. The | |
2658 | * item at 'max_slot' won't be touched. Use (u32)-1 to make us push all the | |
2659 | * items | |
44871b1b CM |
2660 | */ |
2661 | static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root | |
99d8f83c CM |
2662 | *root, struct btrfs_path *path, int min_data_size, |
2663 | int data_size, int empty, u32 max_slot) | |
44871b1b CM |
2664 | { |
2665 | struct extent_buffer *right = path->nodes[0]; | |
2666 | struct extent_buffer *left; | |
2667 | int slot; | |
2668 | int free_space; | |
2669 | u32 right_nritems; | |
2670 | int ret = 0; | |
2671 | ||
2672 | slot = path->slots[1]; | |
2673 | if (slot == 0) | |
2674 | return 1; | |
2675 | if (!path->nodes[1]) | |
2676 | return 1; | |
2677 | ||
2678 | right_nritems = btrfs_header_nritems(right); | |
2679 | if (right_nritems == 0) | |
2680 | return 1; | |
2681 | ||
2682 | btrfs_assert_tree_locked(path->nodes[1]); | |
2683 | ||
2684 | left = read_node_slot(root, path->nodes[1], slot - 1); | |
91ca338d TI |
2685 | if (left == NULL) |
2686 | return 1; | |
2687 | ||
44871b1b CM |
2688 | btrfs_tree_lock(left); |
2689 | btrfs_set_lock_blocking(left); | |
2690 | ||
2691 | free_space = btrfs_leaf_free_space(root, left); | |
2692 | if (free_space < data_size) { | |
2693 | ret = 1; | |
2694 | goto out; | |
2695 | } | |
2696 | ||
2697 | /* cow and double check */ | |
2698 | ret = btrfs_cow_block(trans, root, left, | |
2699 | path->nodes[1], slot - 1, &left); | |
2700 | if (ret) { | |
2701 | /* we hit -ENOSPC, but it isn't fatal here */ | |
2702 | ret = 1; | |
2703 | goto out; | |
2704 | } | |
2705 | ||
2706 | free_space = btrfs_leaf_free_space(root, left); | |
2707 | if (free_space < data_size) { | |
2708 | ret = 1; | |
2709 | goto out; | |
2710 | } | |
2711 | ||
99d8f83c CM |
2712 | return __push_leaf_left(trans, root, path, min_data_size, |
2713 | empty, left, free_space, right_nritems, | |
2714 | max_slot); | |
44871b1b CM |
2715 | out: |
2716 | btrfs_tree_unlock(left); | |
2717 | free_extent_buffer(left); | |
2718 | return ret; | |
2719 | } | |
2720 | ||
2721 | /* | |
2722 | * split the path's leaf in two, making sure there is at least data_size | |
2723 | * available for the resulting leaf level of the path. | |
2724 | * | |
2725 | * returns 0 if all went well and < 0 on failure. | |
2726 | */ | |
2727 | static noinline int copy_for_split(struct btrfs_trans_handle *trans, | |
2728 | struct btrfs_root *root, | |
2729 | struct btrfs_path *path, | |
2730 | struct extent_buffer *l, | |
2731 | struct extent_buffer *right, | |
2732 | int slot, int mid, int nritems) | |
2733 | { | |
2734 | int data_copy_size; | |
2735 | int rt_data_off; | |
2736 | int i; | |
2737 | int ret = 0; | |
2738 | int wret; | |
2739 | struct btrfs_disk_key disk_key; | |
2740 | ||
2741 | nritems = nritems - mid; | |
2742 | btrfs_set_header_nritems(right, nritems); | |
2743 | data_copy_size = btrfs_item_end_nr(l, mid) - leaf_data_end(root, l); | |
2744 | ||
2745 | copy_extent_buffer(right, l, btrfs_item_nr_offset(0), | |
2746 | btrfs_item_nr_offset(mid), | |
2747 | nritems * sizeof(struct btrfs_item)); | |
2748 | ||
2749 | copy_extent_buffer(right, l, | |
2750 | btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) - | |
2751 | data_copy_size, btrfs_leaf_data(l) + | |
2752 | leaf_data_end(root, l), data_copy_size); | |
2753 | ||
2754 | rt_data_off = BTRFS_LEAF_DATA_SIZE(root) - | |
2755 | btrfs_item_end_nr(l, mid); | |
2756 | ||
2757 | for (i = 0; i < nritems; i++) { | |
2758 | struct btrfs_item *item = btrfs_item_nr(right, i); | |
2759 | u32 ioff; | |
2760 | ||
44871b1b CM |
2761 | ioff = btrfs_item_offset(right, item); |
2762 | btrfs_set_item_offset(right, item, ioff + rt_data_off); | |
2763 | } | |
2764 | ||
44871b1b CM |
2765 | btrfs_set_header_nritems(l, mid); |
2766 | ret = 0; | |
2767 | btrfs_item_key(right, &disk_key, 0); | |
2768 | wret = insert_ptr(trans, root, path, &disk_key, right->start, | |
2769 | path->slots[1] + 1, 1); | |
2770 | if (wret) | |
2771 | ret = wret; | |
2772 | ||
2773 | btrfs_mark_buffer_dirty(right); | |
2774 | btrfs_mark_buffer_dirty(l); | |
2775 | BUG_ON(path->slots[0] != slot); | |
2776 | ||
44871b1b CM |
2777 | if (mid <= slot) { |
2778 | btrfs_tree_unlock(path->nodes[0]); | |
2779 | free_extent_buffer(path->nodes[0]); | |
2780 | path->nodes[0] = right; | |
2781 | path->slots[0] -= mid; | |
2782 | path->slots[1] += 1; | |
2783 | } else { | |
2784 | btrfs_tree_unlock(right); | |
2785 | free_extent_buffer(right); | |
2786 | } | |
2787 | ||
2788 | BUG_ON(path->slots[0] < 0); | |
2789 | ||
2790 | return ret; | |
2791 | } | |
2792 | ||
99d8f83c CM |
2793 | /* |
2794 | * double splits happen when we need to insert a big item in the middle | |
2795 | * of a leaf. A double split can leave us with 3 mostly empty leaves: | |
2796 | * leaf: [ slots 0 - N] [ our target ] [ N + 1 - total in leaf ] | |
2797 | * A B C | |
2798 | * | |
2799 | * We avoid this by trying to push the items on either side of our target | |
2800 | * into the adjacent leaves. If all goes well we can avoid the double split | |
2801 | * completely. | |
2802 | */ | |
2803 | static noinline int push_for_double_split(struct btrfs_trans_handle *trans, | |
2804 | struct btrfs_root *root, | |
2805 | struct btrfs_path *path, | |
2806 | int data_size) | |
2807 | { | |
2808 | int ret; | |
2809 | int progress = 0; | |
2810 | int slot; | |
2811 | u32 nritems; | |
2812 | ||
2813 | slot = path->slots[0]; | |
2814 | ||
2815 | /* | |
2816 | * try to push all the items after our slot into the | |
2817 | * right leaf | |
2818 | */ | |
2819 | ret = push_leaf_right(trans, root, path, 1, data_size, 0, slot); | |
2820 | if (ret < 0) | |
2821 | return ret; | |
2822 | ||
2823 | if (ret == 0) | |
2824 | progress++; | |
2825 | ||
2826 | nritems = btrfs_header_nritems(path->nodes[0]); | |
2827 | /* | |
2828 | * our goal is to get our slot at the start or end of a leaf. If | |
2829 | * we've done so we're done | |
2830 | */ | |
2831 | if (path->slots[0] == 0 || path->slots[0] == nritems) | |
2832 | return 0; | |
2833 | ||
2834 | if (btrfs_leaf_free_space(root, path->nodes[0]) >= data_size) | |
2835 | return 0; | |
2836 | ||
2837 | /* try to push all the items before our slot into the next leaf */ | |
2838 | slot = path->slots[0]; | |
2839 | ret = push_leaf_left(trans, root, path, 1, data_size, 0, slot); | |
2840 | if (ret < 0) | |
2841 | return ret; | |
2842 | ||
2843 | if (ret == 0) | |
2844 | progress++; | |
2845 | ||
2846 | if (progress) | |
2847 | return 0; | |
2848 | return 1; | |
2849 | } | |
2850 | ||
74123bd7 CM |
2851 | /* |
2852 | * split the path's leaf in two, making sure there is at least data_size | |
2853 | * available for the resulting leaf level of the path. | |
aa5d6bed CM |
2854 | * |
2855 | * returns 0 if all went well and < 0 on failure. | |
74123bd7 | 2856 | */ |
e02119d5 CM |
2857 | static noinline int split_leaf(struct btrfs_trans_handle *trans, |
2858 | struct btrfs_root *root, | |
2859 | struct btrfs_key *ins_key, | |
2860 | struct btrfs_path *path, int data_size, | |
2861 | int extend) | |
be0e5c09 | 2862 | { |
5d4f98a2 | 2863 | struct btrfs_disk_key disk_key; |
5f39d397 | 2864 | struct extent_buffer *l; |
7518a238 | 2865 | u32 nritems; |
eb60ceac CM |
2866 | int mid; |
2867 | int slot; | |
5f39d397 | 2868 | struct extent_buffer *right; |
d4dbff95 | 2869 | int ret = 0; |
aa5d6bed | 2870 | int wret; |
5d4f98a2 | 2871 | int split; |
cc0c5538 | 2872 | int num_doubles = 0; |
99d8f83c | 2873 | int tried_avoid_double = 0; |
aa5d6bed | 2874 | |
a5719521 YZ |
2875 | l = path->nodes[0]; |
2876 | slot = path->slots[0]; | |
2877 | if (extend && data_size + btrfs_item_size_nr(l, slot) + | |
2878 | sizeof(struct btrfs_item) > BTRFS_LEAF_DATA_SIZE(root)) | |
2879 | return -EOVERFLOW; | |
2880 | ||
40689478 | 2881 | /* first try to make some room by pushing left and right */ |
99d8f83c CM |
2882 | if (data_size) { |
2883 | wret = push_leaf_right(trans, root, path, data_size, | |
2884 | data_size, 0, 0); | |
d397712b | 2885 | if (wret < 0) |
eaee50e8 | 2886 | return wret; |
3685f791 | 2887 | if (wret) { |
99d8f83c CM |
2888 | wret = push_leaf_left(trans, root, path, data_size, |
2889 | data_size, 0, (u32)-1); | |
3685f791 CM |
2890 | if (wret < 0) |
2891 | return wret; | |
2892 | } | |
2893 | l = path->nodes[0]; | |
aa5d6bed | 2894 | |
3685f791 | 2895 | /* did the pushes work? */ |
87b29b20 | 2896 | if (btrfs_leaf_free_space(root, l) >= data_size) |
3685f791 | 2897 | return 0; |
3326d1b0 | 2898 | } |
aa5d6bed | 2899 | |
5c680ed6 | 2900 | if (!path->nodes[1]) { |
e089f05c | 2901 | ret = insert_new_root(trans, root, path, 1); |
5c680ed6 CM |
2902 | if (ret) |
2903 | return ret; | |
2904 | } | |
cc0c5538 | 2905 | again: |
5d4f98a2 | 2906 | split = 1; |
cc0c5538 | 2907 | l = path->nodes[0]; |
eb60ceac | 2908 | slot = path->slots[0]; |
5f39d397 | 2909 | nritems = btrfs_header_nritems(l); |
d397712b | 2910 | mid = (nritems + 1) / 2; |
54aa1f4d | 2911 | |
5d4f98a2 YZ |
2912 | if (mid <= slot) { |
2913 | if (nritems == 1 || | |
2914 | leaf_space_used(l, mid, nritems - mid) + data_size > | |
2915 | BTRFS_LEAF_DATA_SIZE(root)) { | |
2916 | if (slot >= nritems) { | |
2917 | split = 0; | |
2918 | } else { | |
2919 | mid = slot; | |
2920 | if (mid != nritems && | |
2921 | leaf_space_used(l, mid, nritems - mid) + | |
2922 | data_size > BTRFS_LEAF_DATA_SIZE(root)) { | |
99d8f83c CM |
2923 | if (data_size && !tried_avoid_double) |
2924 | goto push_for_double; | |
5d4f98a2 YZ |
2925 | split = 2; |
2926 | } | |
2927 | } | |
2928 | } | |
2929 | } else { | |
2930 | if (leaf_space_used(l, 0, mid) + data_size > | |
2931 | BTRFS_LEAF_DATA_SIZE(root)) { | |
2932 | if (!extend && data_size && slot == 0) { | |
2933 | split = 0; | |
2934 | } else if ((extend || !data_size) && slot == 0) { | |
2935 | mid = 1; | |
2936 | } else { | |
2937 | mid = slot; | |
2938 | if (mid != nritems && | |
2939 | leaf_space_used(l, mid, nritems - mid) + | |
2940 | data_size > BTRFS_LEAF_DATA_SIZE(root)) { | |
99d8f83c CM |
2941 | if (data_size && !tried_avoid_double) |
2942 | goto push_for_double; | |
5d4f98a2 YZ |
2943 | split = 2 ; |
2944 | } | |
2945 | } | |
2946 | } | |
2947 | } | |
2948 | ||
2949 | if (split == 0) | |
2950 | btrfs_cpu_key_to_disk(&disk_key, ins_key); | |
2951 | else | |
2952 | btrfs_item_key(l, &disk_key, mid); | |
2953 | ||
2954 | right = btrfs_alloc_free_block(trans, root, root->leafsize, 0, | |
31840ae1 | 2955 | root->root_key.objectid, |
5d4f98a2 | 2956 | &disk_key, 0, l->start, 0); |
f0486c68 | 2957 | if (IS_ERR(right)) |
5f39d397 | 2958 | return PTR_ERR(right); |
f0486c68 YZ |
2959 | |
2960 | root_add_used(root, root->leafsize); | |
5f39d397 CM |
2961 | |
2962 | memset_extent_buffer(right, 0, 0, sizeof(struct btrfs_header)); | |
db94535d | 2963 | btrfs_set_header_bytenr(right, right->start); |
5f39d397 | 2964 | btrfs_set_header_generation(right, trans->transid); |
5d4f98a2 | 2965 | btrfs_set_header_backref_rev(right, BTRFS_MIXED_BACKREF_REV); |
5f39d397 CM |
2966 | btrfs_set_header_owner(right, root->root_key.objectid); |
2967 | btrfs_set_header_level(right, 0); | |
2968 | write_extent_buffer(right, root->fs_info->fsid, | |
2969 | (unsigned long)btrfs_header_fsid(right), | |
2970 | BTRFS_FSID_SIZE); | |
e17cade2 CM |
2971 | |
2972 | write_extent_buffer(right, root->fs_info->chunk_tree_uuid, | |
2973 | (unsigned long)btrfs_header_chunk_tree_uuid(right), | |
2974 | BTRFS_UUID_SIZE); | |
44871b1b | 2975 | |
5d4f98a2 YZ |
2976 | if (split == 0) { |
2977 | if (mid <= slot) { | |
2978 | btrfs_set_header_nritems(right, 0); | |
2979 | wret = insert_ptr(trans, root, path, | |
2980 | &disk_key, right->start, | |
2981 | path->slots[1] + 1, 1); | |
2982 | if (wret) | |
2983 | ret = wret; | |
925baedd | 2984 | |
5d4f98a2 YZ |
2985 | btrfs_tree_unlock(path->nodes[0]); |
2986 | free_extent_buffer(path->nodes[0]); | |
2987 | path->nodes[0] = right; | |
2988 | path->slots[0] = 0; | |
2989 | path->slots[1] += 1; | |
2990 | } else { | |
2991 | btrfs_set_header_nritems(right, 0); | |
2992 | wret = insert_ptr(trans, root, path, | |
2993 | &disk_key, | |
2994 | right->start, | |
2995 | path->slots[1], 1); | |
2996 | if (wret) | |
2997 | ret = wret; | |
2998 | btrfs_tree_unlock(path->nodes[0]); | |
2999 | free_extent_buffer(path->nodes[0]); | |
3000 | path->nodes[0] = right; | |
3001 | path->slots[0] = 0; | |
3002 | if (path->slots[1] == 0) { | |
3003 | wret = fixup_low_keys(trans, root, | |
3004 | path, &disk_key, 1); | |
d4dbff95 CM |
3005 | if (wret) |
3006 | ret = wret; | |
5ee78ac7 | 3007 | } |
d4dbff95 | 3008 | } |
5d4f98a2 YZ |
3009 | btrfs_mark_buffer_dirty(right); |
3010 | return ret; | |
d4dbff95 | 3011 | } |
74123bd7 | 3012 | |
44871b1b | 3013 | ret = copy_for_split(trans, root, path, l, right, slot, mid, nritems); |
31840ae1 ZY |
3014 | BUG_ON(ret); |
3015 | ||
5d4f98a2 | 3016 | if (split == 2) { |
cc0c5538 CM |
3017 | BUG_ON(num_doubles != 0); |
3018 | num_doubles++; | |
3019 | goto again; | |
a429e513 | 3020 | } |
44871b1b | 3021 | |
be0e5c09 | 3022 | return ret; |
99d8f83c CM |
3023 | |
3024 | push_for_double: | |
3025 | push_for_double_split(trans, root, path, data_size); | |
3026 | tried_avoid_double = 1; | |
3027 | if (btrfs_leaf_free_space(root, path->nodes[0]) >= data_size) | |
3028 | return 0; | |
3029 | goto again; | |
be0e5c09 CM |
3030 | } |
3031 | ||
ad48fd75 YZ |
3032 | static noinline int setup_leaf_for_split(struct btrfs_trans_handle *trans, |
3033 | struct btrfs_root *root, | |
3034 | struct btrfs_path *path, int ins_len) | |
459931ec | 3035 | { |
ad48fd75 | 3036 | struct btrfs_key key; |
459931ec | 3037 | struct extent_buffer *leaf; |
ad48fd75 YZ |
3038 | struct btrfs_file_extent_item *fi; |
3039 | u64 extent_len = 0; | |
3040 | u32 item_size; | |
3041 | int ret; | |
459931ec CM |
3042 | |
3043 | leaf = path->nodes[0]; | |
ad48fd75 YZ |
3044 | btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
3045 | ||
3046 | BUG_ON(key.type != BTRFS_EXTENT_DATA_KEY && | |
3047 | key.type != BTRFS_EXTENT_CSUM_KEY); | |
3048 | ||
3049 | if (btrfs_leaf_free_space(root, leaf) >= ins_len) | |
3050 | return 0; | |
459931ec CM |
3051 | |
3052 | item_size = btrfs_item_size_nr(leaf, path->slots[0]); | |
ad48fd75 YZ |
3053 | if (key.type == BTRFS_EXTENT_DATA_KEY) { |
3054 | fi = btrfs_item_ptr(leaf, path->slots[0], | |
3055 | struct btrfs_file_extent_item); | |
3056 | extent_len = btrfs_file_extent_num_bytes(leaf, fi); | |
3057 | } | |
b3b4aa74 | 3058 | btrfs_release_path(path); |
459931ec | 3059 | |
459931ec | 3060 | path->keep_locks = 1; |
ad48fd75 YZ |
3061 | path->search_for_split = 1; |
3062 | ret = btrfs_search_slot(trans, root, &key, path, 0, 1); | |
459931ec | 3063 | path->search_for_split = 0; |
ad48fd75 YZ |
3064 | if (ret < 0) |
3065 | goto err; | |
459931ec | 3066 | |
ad48fd75 YZ |
3067 | ret = -EAGAIN; |
3068 | leaf = path->nodes[0]; | |
459931ec | 3069 | /* if our item isn't there or got smaller, return now */ |
ad48fd75 YZ |
3070 | if (ret > 0 || item_size != btrfs_item_size_nr(leaf, path->slots[0])) |
3071 | goto err; | |
3072 | ||
109f6aef CM |
3073 | /* the leaf has changed, it now has room. return now */ |
3074 | if (btrfs_leaf_free_space(root, path->nodes[0]) >= ins_len) | |
3075 | goto err; | |
3076 | ||
ad48fd75 YZ |
3077 | if (key.type == BTRFS_EXTENT_DATA_KEY) { |
3078 | fi = btrfs_item_ptr(leaf, path->slots[0], | |
3079 | struct btrfs_file_extent_item); | |
3080 | if (extent_len != btrfs_file_extent_num_bytes(leaf, fi)) | |
3081 | goto err; | |
459931ec CM |
3082 | } |
3083 | ||
b9473439 | 3084 | btrfs_set_path_blocking(path); |
ad48fd75 | 3085 | ret = split_leaf(trans, root, &key, path, ins_len, 1); |
f0486c68 YZ |
3086 | if (ret) |
3087 | goto err; | |
459931ec | 3088 | |
ad48fd75 | 3089 | path->keep_locks = 0; |
b9473439 | 3090 | btrfs_unlock_up_safe(path, 1); |
ad48fd75 YZ |
3091 | return 0; |
3092 | err: | |
3093 | path->keep_locks = 0; | |
3094 | return ret; | |
3095 | } | |
3096 | ||
3097 | static noinline int split_item(struct btrfs_trans_handle *trans, | |
3098 | struct btrfs_root *root, | |
3099 | struct btrfs_path *path, | |
3100 | struct btrfs_key *new_key, | |
3101 | unsigned long split_offset) | |
3102 | { | |
3103 | struct extent_buffer *leaf; | |
3104 | struct btrfs_item *item; | |
3105 | struct btrfs_item *new_item; | |
3106 | int slot; | |
3107 | char *buf; | |
3108 | u32 nritems; | |
3109 | u32 item_size; | |
3110 | u32 orig_offset; | |
3111 | struct btrfs_disk_key disk_key; | |
3112 | ||
b9473439 CM |
3113 | leaf = path->nodes[0]; |
3114 | BUG_ON(btrfs_leaf_free_space(root, leaf) < sizeof(struct btrfs_item)); | |
3115 | ||
b4ce94de CM |
3116 | btrfs_set_path_blocking(path); |
3117 | ||
459931ec CM |
3118 | item = btrfs_item_nr(leaf, path->slots[0]); |
3119 | orig_offset = btrfs_item_offset(leaf, item); | |
3120 | item_size = btrfs_item_size(leaf, item); | |
3121 | ||
459931ec | 3122 | buf = kmalloc(item_size, GFP_NOFS); |
ad48fd75 YZ |
3123 | if (!buf) |
3124 | return -ENOMEM; | |
3125 | ||
459931ec CM |
3126 | read_extent_buffer(leaf, buf, btrfs_item_ptr_offset(leaf, |
3127 | path->slots[0]), item_size); | |
459931ec | 3128 | |
ad48fd75 | 3129 | slot = path->slots[0] + 1; |
459931ec | 3130 | nritems = btrfs_header_nritems(leaf); |
459931ec CM |
3131 | if (slot != nritems) { |
3132 | /* shift the items */ | |
3133 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + 1), | |
ad48fd75 YZ |
3134 | btrfs_item_nr_offset(slot), |
3135 | (nritems - slot) * sizeof(struct btrfs_item)); | |
459931ec CM |
3136 | } |
3137 | ||
3138 | btrfs_cpu_key_to_disk(&disk_key, new_key); | |
3139 | btrfs_set_item_key(leaf, &disk_key, slot); | |
3140 | ||
3141 | new_item = btrfs_item_nr(leaf, slot); | |
3142 | ||
3143 | btrfs_set_item_offset(leaf, new_item, orig_offset); | |
3144 | btrfs_set_item_size(leaf, new_item, item_size - split_offset); | |
3145 | ||
3146 | btrfs_set_item_offset(leaf, item, | |
3147 | orig_offset + item_size - split_offset); | |
3148 | btrfs_set_item_size(leaf, item, split_offset); | |
3149 | ||
3150 | btrfs_set_header_nritems(leaf, nritems + 1); | |
3151 | ||
3152 | /* write the data for the start of the original item */ | |
3153 | write_extent_buffer(leaf, buf, | |
3154 | btrfs_item_ptr_offset(leaf, path->slots[0]), | |
3155 | split_offset); | |
3156 | ||
3157 | /* write the data for the new item */ | |
3158 | write_extent_buffer(leaf, buf + split_offset, | |
3159 | btrfs_item_ptr_offset(leaf, slot), | |
3160 | item_size - split_offset); | |
3161 | btrfs_mark_buffer_dirty(leaf); | |
3162 | ||
ad48fd75 | 3163 | BUG_ON(btrfs_leaf_free_space(root, leaf) < 0); |
459931ec | 3164 | kfree(buf); |
ad48fd75 YZ |
3165 | return 0; |
3166 | } | |
3167 | ||
3168 | /* | |
3169 | * This function splits a single item into two items, | |
3170 | * giving 'new_key' to the new item and splitting the | |
3171 | * old one at split_offset (from the start of the item). | |
3172 | * | |
3173 | * The path may be released by this operation. After | |
3174 | * the split, the path is pointing to the old item. The | |
3175 | * new item is going to be in the same node as the old one. | |
3176 | * | |
3177 | * Note, the item being split must be smaller enough to live alone on | |
3178 | * a tree block with room for one extra struct btrfs_item | |
3179 | * | |
3180 | * This allows us to split the item in place, keeping a lock on the | |
3181 | * leaf the entire time. | |
3182 | */ | |
3183 | int btrfs_split_item(struct btrfs_trans_handle *trans, | |
3184 | struct btrfs_root *root, | |
3185 | struct btrfs_path *path, | |
3186 | struct btrfs_key *new_key, | |
3187 | unsigned long split_offset) | |
3188 | { | |
3189 | int ret; | |
3190 | ret = setup_leaf_for_split(trans, root, path, | |
3191 | sizeof(struct btrfs_item)); | |
3192 | if (ret) | |
3193 | return ret; | |
3194 | ||
3195 | ret = split_item(trans, root, path, new_key, split_offset); | |
459931ec CM |
3196 | return ret; |
3197 | } | |
3198 | ||
ad48fd75 YZ |
3199 | /* |
3200 | * This function duplicate a item, giving 'new_key' to the new item. | |
3201 | * It guarantees both items live in the same tree leaf and the new item | |
3202 | * is contiguous with the original item. | |
3203 | * | |
3204 | * This allows us to split file extent in place, keeping a lock on the | |
3205 | * leaf the entire time. | |
3206 | */ | |
3207 | int btrfs_duplicate_item(struct btrfs_trans_handle *trans, | |
3208 | struct btrfs_root *root, | |
3209 | struct btrfs_path *path, | |
3210 | struct btrfs_key *new_key) | |
3211 | { | |
3212 | struct extent_buffer *leaf; | |
3213 | int ret; | |
3214 | u32 item_size; | |
3215 | ||
3216 | leaf = path->nodes[0]; | |
3217 | item_size = btrfs_item_size_nr(leaf, path->slots[0]); | |
3218 | ret = setup_leaf_for_split(trans, root, path, | |
3219 | item_size + sizeof(struct btrfs_item)); | |
3220 | if (ret) | |
3221 | return ret; | |
3222 | ||
3223 | path->slots[0]++; | |
3224 | ret = setup_items_for_insert(trans, root, path, new_key, &item_size, | |
3225 | item_size, item_size + | |
3226 | sizeof(struct btrfs_item), 1); | |
3227 | BUG_ON(ret); | |
3228 | ||
3229 | leaf = path->nodes[0]; | |
3230 | memcpy_extent_buffer(leaf, | |
3231 | btrfs_item_ptr_offset(leaf, path->slots[0]), | |
3232 | btrfs_item_ptr_offset(leaf, path->slots[0] - 1), | |
3233 | item_size); | |
3234 | return 0; | |
3235 | } | |
3236 | ||
d352ac68 CM |
3237 | /* |
3238 | * make the item pointed to by the path smaller. new_size indicates | |
3239 | * how small to make it, and from_end tells us if we just chop bytes | |
3240 | * off the end of the item or if we shift the item to chop bytes off | |
3241 | * the front. | |
3242 | */ | |
b18c6685 CM |
3243 | int btrfs_truncate_item(struct btrfs_trans_handle *trans, |
3244 | struct btrfs_root *root, | |
3245 | struct btrfs_path *path, | |
179e29e4 | 3246 | u32 new_size, int from_end) |
b18c6685 | 3247 | { |
b18c6685 | 3248 | int slot; |
5f39d397 CM |
3249 | struct extent_buffer *leaf; |
3250 | struct btrfs_item *item; | |
b18c6685 CM |
3251 | u32 nritems; |
3252 | unsigned int data_end; | |
3253 | unsigned int old_data_start; | |
3254 | unsigned int old_size; | |
3255 | unsigned int size_diff; | |
3256 | int i; | |
3257 | ||
5f39d397 | 3258 | leaf = path->nodes[0]; |
179e29e4 CM |
3259 | slot = path->slots[0]; |
3260 | ||
3261 | old_size = btrfs_item_size_nr(leaf, slot); | |
3262 | if (old_size == new_size) | |
3263 | return 0; | |
b18c6685 | 3264 | |
5f39d397 | 3265 | nritems = btrfs_header_nritems(leaf); |
b18c6685 CM |
3266 | data_end = leaf_data_end(root, leaf); |
3267 | ||
5f39d397 | 3268 | old_data_start = btrfs_item_offset_nr(leaf, slot); |
179e29e4 | 3269 | |
b18c6685 CM |
3270 | size_diff = old_size - new_size; |
3271 | ||
3272 | BUG_ON(slot < 0); | |
3273 | BUG_ON(slot >= nritems); | |
3274 | ||
3275 | /* | |
3276 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
3277 | */ | |
3278 | /* first correct the data pointers */ | |
3279 | for (i = slot; i < nritems; i++) { | |
5f39d397 CM |
3280 | u32 ioff; |
3281 | item = btrfs_item_nr(leaf, i); | |
db94535d | 3282 | |
5f39d397 CM |
3283 | ioff = btrfs_item_offset(leaf, item); |
3284 | btrfs_set_item_offset(leaf, item, ioff + size_diff); | |
b18c6685 | 3285 | } |
db94535d | 3286 | |
b18c6685 | 3287 | /* shift the data */ |
179e29e4 CM |
3288 | if (from_end) { |
3289 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + | |
3290 | data_end + size_diff, btrfs_leaf_data(leaf) + | |
3291 | data_end, old_data_start + new_size - data_end); | |
3292 | } else { | |
3293 | struct btrfs_disk_key disk_key; | |
3294 | u64 offset; | |
3295 | ||
3296 | btrfs_item_key(leaf, &disk_key, slot); | |
3297 | ||
3298 | if (btrfs_disk_key_type(&disk_key) == BTRFS_EXTENT_DATA_KEY) { | |
3299 | unsigned long ptr; | |
3300 | struct btrfs_file_extent_item *fi; | |
3301 | ||
3302 | fi = btrfs_item_ptr(leaf, slot, | |
3303 | struct btrfs_file_extent_item); | |
3304 | fi = (struct btrfs_file_extent_item *)( | |
3305 | (unsigned long)fi - size_diff); | |
3306 | ||
3307 | if (btrfs_file_extent_type(leaf, fi) == | |
3308 | BTRFS_FILE_EXTENT_INLINE) { | |
3309 | ptr = btrfs_item_ptr_offset(leaf, slot); | |
3310 | memmove_extent_buffer(leaf, ptr, | |
d397712b CM |
3311 | (unsigned long)fi, |
3312 | offsetof(struct btrfs_file_extent_item, | |
179e29e4 CM |
3313 | disk_bytenr)); |
3314 | } | |
3315 | } | |
3316 | ||
3317 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + | |
3318 | data_end + size_diff, btrfs_leaf_data(leaf) + | |
3319 | data_end, old_data_start - data_end); | |
3320 | ||
3321 | offset = btrfs_disk_key_offset(&disk_key); | |
3322 | btrfs_set_disk_key_offset(&disk_key, offset + size_diff); | |
3323 | btrfs_set_item_key(leaf, &disk_key, slot); | |
3324 | if (slot == 0) | |
3325 | fixup_low_keys(trans, root, path, &disk_key, 1); | |
3326 | } | |
5f39d397 CM |
3327 | |
3328 | item = btrfs_item_nr(leaf, slot); | |
3329 | btrfs_set_item_size(leaf, item, new_size); | |
3330 | btrfs_mark_buffer_dirty(leaf); | |
b18c6685 | 3331 | |
5f39d397 CM |
3332 | if (btrfs_leaf_free_space(root, leaf) < 0) { |
3333 | btrfs_print_leaf(root, leaf); | |
b18c6685 | 3334 | BUG(); |
5f39d397 | 3335 | } |
1cd30799 | 3336 | return 0; |
b18c6685 CM |
3337 | } |
3338 | ||
d352ac68 CM |
3339 | /* |
3340 | * make the item pointed to by the path bigger, data_size is the new size. | |
3341 | */ | |
5f39d397 CM |
3342 | int btrfs_extend_item(struct btrfs_trans_handle *trans, |
3343 | struct btrfs_root *root, struct btrfs_path *path, | |
3344 | u32 data_size) | |
6567e837 | 3345 | { |
6567e837 | 3346 | int slot; |
5f39d397 CM |
3347 | struct extent_buffer *leaf; |
3348 | struct btrfs_item *item; | |
6567e837 CM |
3349 | u32 nritems; |
3350 | unsigned int data_end; | |
3351 | unsigned int old_data; | |
3352 | unsigned int old_size; | |
3353 | int i; | |
3354 | ||
5f39d397 | 3355 | leaf = path->nodes[0]; |
6567e837 | 3356 | |
5f39d397 | 3357 | nritems = btrfs_header_nritems(leaf); |
6567e837 CM |
3358 | data_end = leaf_data_end(root, leaf); |
3359 | ||
5f39d397 CM |
3360 | if (btrfs_leaf_free_space(root, leaf) < data_size) { |
3361 | btrfs_print_leaf(root, leaf); | |
6567e837 | 3362 | BUG(); |
5f39d397 | 3363 | } |
6567e837 | 3364 | slot = path->slots[0]; |
5f39d397 | 3365 | old_data = btrfs_item_end_nr(leaf, slot); |
6567e837 CM |
3366 | |
3367 | BUG_ON(slot < 0); | |
3326d1b0 CM |
3368 | if (slot >= nritems) { |
3369 | btrfs_print_leaf(root, leaf); | |
d397712b CM |
3370 | printk(KERN_CRIT "slot %d too large, nritems %d\n", |
3371 | slot, nritems); | |
3326d1b0 CM |
3372 | BUG_ON(1); |
3373 | } | |
6567e837 CM |
3374 | |
3375 | /* | |
3376 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
3377 | */ | |
3378 | /* first correct the data pointers */ | |
3379 | for (i = slot; i < nritems; i++) { | |
5f39d397 CM |
3380 | u32 ioff; |
3381 | item = btrfs_item_nr(leaf, i); | |
db94535d | 3382 | |
5f39d397 CM |
3383 | ioff = btrfs_item_offset(leaf, item); |
3384 | btrfs_set_item_offset(leaf, item, ioff - data_size); | |
6567e837 | 3385 | } |
5f39d397 | 3386 | |
6567e837 | 3387 | /* shift the data */ |
5f39d397 | 3388 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + |
6567e837 CM |
3389 | data_end - data_size, btrfs_leaf_data(leaf) + |
3390 | data_end, old_data - data_end); | |
5f39d397 | 3391 | |
6567e837 | 3392 | data_end = old_data; |
5f39d397 CM |
3393 | old_size = btrfs_item_size_nr(leaf, slot); |
3394 | item = btrfs_item_nr(leaf, slot); | |
3395 | btrfs_set_item_size(leaf, item, old_size + data_size); | |
3396 | btrfs_mark_buffer_dirty(leaf); | |
6567e837 | 3397 | |
5f39d397 CM |
3398 | if (btrfs_leaf_free_space(root, leaf) < 0) { |
3399 | btrfs_print_leaf(root, leaf); | |
6567e837 | 3400 | BUG(); |
5f39d397 | 3401 | } |
1cd30799 | 3402 | return 0; |
6567e837 CM |
3403 | } |
3404 | ||
f3465ca4 JB |
3405 | /* |
3406 | * Given a key and some data, insert items into the tree. | |
3407 | * This does all the path init required, making room in the tree if needed. | |
3408 | * Returns the number of keys that were inserted. | |
3409 | */ | |
3410 | int btrfs_insert_some_items(struct btrfs_trans_handle *trans, | |
3411 | struct btrfs_root *root, | |
3412 | struct btrfs_path *path, | |
3413 | struct btrfs_key *cpu_key, u32 *data_size, | |
3414 | int nr) | |
3415 | { | |
3416 | struct extent_buffer *leaf; | |
3417 | struct btrfs_item *item; | |
3418 | int ret = 0; | |
3419 | int slot; | |
f3465ca4 JB |
3420 | int i; |
3421 | u32 nritems; | |
3422 | u32 total_data = 0; | |
3423 | u32 total_size = 0; | |
3424 | unsigned int data_end; | |
3425 | struct btrfs_disk_key disk_key; | |
3426 | struct btrfs_key found_key; | |
3427 | ||
87b29b20 YZ |
3428 | for (i = 0; i < nr; i++) { |
3429 | if (total_size + data_size[i] + sizeof(struct btrfs_item) > | |
3430 | BTRFS_LEAF_DATA_SIZE(root)) { | |
3431 | break; | |
3432 | nr = i; | |
3433 | } | |
f3465ca4 | 3434 | total_data += data_size[i]; |
87b29b20 YZ |
3435 | total_size += data_size[i] + sizeof(struct btrfs_item); |
3436 | } | |
3437 | BUG_ON(nr == 0); | |
f3465ca4 | 3438 | |
f3465ca4 JB |
3439 | ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1); |
3440 | if (ret == 0) | |
3441 | return -EEXIST; | |
3442 | if (ret < 0) | |
3443 | goto out; | |
3444 | ||
f3465ca4 JB |
3445 | leaf = path->nodes[0]; |
3446 | ||
3447 | nritems = btrfs_header_nritems(leaf); | |
3448 | data_end = leaf_data_end(root, leaf); | |
3449 | ||
3450 | if (btrfs_leaf_free_space(root, leaf) < total_size) { | |
3451 | for (i = nr; i >= 0; i--) { | |
3452 | total_data -= data_size[i]; | |
3453 | total_size -= data_size[i] + sizeof(struct btrfs_item); | |
3454 | if (total_size < btrfs_leaf_free_space(root, leaf)) | |
3455 | break; | |
3456 | } | |
3457 | nr = i; | |
3458 | } | |
3459 | ||
3460 | slot = path->slots[0]; | |
3461 | BUG_ON(slot < 0); | |
3462 | ||
3463 | if (slot != nritems) { | |
3464 | unsigned int old_data = btrfs_item_end_nr(leaf, slot); | |
3465 | ||
3466 | item = btrfs_item_nr(leaf, slot); | |
3467 | btrfs_item_key_to_cpu(leaf, &found_key, slot); | |
3468 | ||
3469 | /* figure out how many keys we can insert in here */ | |
3470 | total_data = data_size[0]; | |
3471 | for (i = 1; i < nr; i++) { | |
5d4f98a2 | 3472 | if (btrfs_comp_cpu_keys(&found_key, cpu_key + i) <= 0) |
f3465ca4 JB |
3473 | break; |
3474 | total_data += data_size[i]; | |
3475 | } | |
3476 | nr = i; | |
3477 | ||
3478 | if (old_data < data_end) { | |
3479 | btrfs_print_leaf(root, leaf); | |
d397712b | 3480 | printk(KERN_CRIT "slot %d old_data %d data_end %d\n", |
f3465ca4 JB |
3481 | slot, old_data, data_end); |
3482 | BUG_ON(1); | |
3483 | } | |
3484 | /* | |
3485 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
3486 | */ | |
3487 | /* first correct the data pointers */ | |
f3465ca4 JB |
3488 | for (i = slot; i < nritems; i++) { |
3489 | u32 ioff; | |
3490 | ||
3491 | item = btrfs_item_nr(leaf, i); | |
f3465ca4 JB |
3492 | ioff = btrfs_item_offset(leaf, item); |
3493 | btrfs_set_item_offset(leaf, item, ioff - total_data); | |
3494 | } | |
f3465ca4 JB |
3495 | /* shift the items */ |
3496 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr), | |
3497 | btrfs_item_nr_offset(slot), | |
3498 | (nritems - slot) * sizeof(struct btrfs_item)); | |
3499 | ||
3500 | /* shift the data */ | |
3501 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + | |
3502 | data_end - total_data, btrfs_leaf_data(leaf) + | |
3503 | data_end, old_data - data_end); | |
3504 | data_end = old_data; | |
3505 | } else { | |
3506 | /* | |
3507 | * this sucks but it has to be done, if we are inserting at | |
3508 | * the end of the leaf only insert 1 of the items, since we | |
3509 | * have no way of knowing whats on the next leaf and we'd have | |
3510 | * to drop our current locks to figure it out | |
3511 | */ | |
3512 | nr = 1; | |
3513 | } | |
3514 | ||
3515 | /* setup the item for the new data */ | |
3516 | for (i = 0; i < nr; i++) { | |
3517 | btrfs_cpu_key_to_disk(&disk_key, cpu_key + i); | |
3518 | btrfs_set_item_key(leaf, &disk_key, slot + i); | |
3519 | item = btrfs_item_nr(leaf, slot + i); | |
3520 | btrfs_set_item_offset(leaf, item, data_end - data_size[i]); | |
3521 | data_end -= data_size[i]; | |
3522 | btrfs_set_item_size(leaf, item, data_size[i]); | |
3523 | } | |
3524 | btrfs_set_header_nritems(leaf, nritems + nr); | |
3525 | btrfs_mark_buffer_dirty(leaf); | |
3526 | ||
3527 | ret = 0; | |
3528 | if (slot == 0) { | |
3529 | btrfs_cpu_key_to_disk(&disk_key, cpu_key); | |
3530 | ret = fixup_low_keys(trans, root, path, &disk_key, 1); | |
3531 | } | |
3532 | ||
3533 | if (btrfs_leaf_free_space(root, leaf) < 0) { | |
3534 | btrfs_print_leaf(root, leaf); | |
3535 | BUG(); | |
3536 | } | |
3537 | out: | |
3538 | if (!ret) | |
3539 | ret = nr; | |
3540 | return ret; | |
3541 | } | |
3542 | ||
74123bd7 | 3543 | /* |
44871b1b CM |
3544 | * this is a helper for btrfs_insert_empty_items, the main goal here is |
3545 | * to save stack depth by doing the bulk of the work in a function | |
3546 | * that doesn't call btrfs_search_slot | |
74123bd7 | 3547 | */ |
16cdcec7 MX |
3548 | int setup_items_for_insert(struct btrfs_trans_handle *trans, |
3549 | struct btrfs_root *root, struct btrfs_path *path, | |
3550 | struct btrfs_key *cpu_key, u32 *data_size, | |
3551 | u32 total_data, u32 total_size, int nr) | |
be0e5c09 | 3552 | { |
5f39d397 | 3553 | struct btrfs_item *item; |
9c58309d | 3554 | int i; |
7518a238 | 3555 | u32 nritems; |
be0e5c09 | 3556 | unsigned int data_end; |
e2fa7227 | 3557 | struct btrfs_disk_key disk_key; |
44871b1b CM |
3558 | int ret; |
3559 | struct extent_buffer *leaf; | |
3560 | int slot; | |
e2fa7227 | 3561 | |
5f39d397 | 3562 | leaf = path->nodes[0]; |
44871b1b | 3563 | slot = path->slots[0]; |
74123bd7 | 3564 | |
5f39d397 | 3565 | nritems = btrfs_header_nritems(leaf); |
123abc88 | 3566 | data_end = leaf_data_end(root, leaf); |
eb60ceac | 3567 | |
f25956cc | 3568 | if (btrfs_leaf_free_space(root, leaf) < total_size) { |
3326d1b0 | 3569 | btrfs_print_leaf(root, leaf); |
d397712b | 3570 | printk(KERN_CRIT "not enough freespace need %u have %d\n", |
9c58309d | 3571 | total_size, btrfs_leaf_free_space(root, leaf)); |
be0e5c09 | 3572 | BUG(); |
d4dbff95 | 3573 | } |
5f39d397 | 3574 | |
be0e5c09 | 3575 | if (slot != nritems) { |
5f39d397 | 3576 | unsigned int old_data = btrfs_item_end_nr(leaf, slot); |
be0e5c09 | 3577 | |
5f39d397 CM |
3578 | if (old_data < data_end) { |
3579 | btrfs_print_leaf(root, leaf); | |
d397712b | 3580 | printk(KERN_CRIT "slot %d old_data %d data_end %d\n", |
5f39d397 CM |
3581 | slot, old_data, data_end); |
3582 | BUG_ON(1); | |
3583 | } | |
be0e5c09 CM |
3584 | /* |
3585 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
3586 | */ | |
3587 | /* first correct the data pointers */ | |
0783fcfc | 3588 | for (i = slot; i < nritems; i++) { |
5f39d397 | 3589 | u32 ioff; |
db94535d | 3590 | |
5f39d397 CM |
3591 | item = btrfs_item_nr(leaf, i); |
3592 | ioff = btrfs_item_offset(leaf, item); | |
9c58309d | 3593 | btrfs_set_item_offset(leaf, item, ioff - total_data); |
0783fcfc | 3594 | } |
be0e5c09 | 3595 | /* shift the items */ |
9c58309d | 3596 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr), |
5f39d397 | 3597 | btrfs_item_nr_offset(slot), |
d6025579 | 3598 | (nritems - slot) * sizeof(struct btrfs_item)); |
be0e5c09 CM |
3599 | |
3600 | /* shift the data */ | |
5f39d397 | 3601 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + |
9c58309d | 3602 | data_end - total_data, btrfs_leaf_data(leaf) + |
d6025579 | 3603 | data_end, old_data - data_end); |
be0e5c09 CM |
3604 | data_end = old_data; |
3605 | } | |
5f39d397 | 3606 | |
62e2749e | 3607 | /* setup the item for the new data */ |
9c58309d CM |
3608 | for (i = 0; i < nr; i++) { |
3609 | btrfs_cpu_key_to_disk(&disk_key, cpu_key + i); | |
3610 | btrfs_set_item_key(leaf, &disk_key, slot + i); | |
3611 | item = btrfs_item_nr(leaf, slot + i); | |
3612 | btrfs_set_item_offset(leaf, item, data_end - data_size[i]); | |
3613 | data_end -= data_size[i]; | |
3614 | btrfs_set_item_size(leaf, item, data_size[i]); | |
3615 | } | |
44871b1b | 3616 | |
9c58309d | 3617 | btrfs_set_header_nritems(leaf, nritems + nr); |
aa5d6bed CM |
3618 | |
3619 | ret = 0; | |
5a01a2e3 CM |
3620 | if (slot == 0) { |
3621 | btrfs_cpu_key_to_disk(&disk_key, cpu_key); | |
e089f05c | 3622 | ret = fixup_low_keys(trans, root, path, &disk_key, 1); |
5a01a2e3 | 3623 | } |
b9473439 CM |
3624 | btrfs_unlock_up_safe(path, 1); |
3625 | btrfs_mark_buffer_dirty(leaf); | |
aa5d6bed | 3626 | |
5f39d397 CM |
3627 | if (btrfs_leaf_free_space(root, leaf) < 0) { |
3628 | btrfs_print_leaf(root, leaf); | |
be0e5c09 | 3629 | BUG(); |
5f39d397 | 3630 | } |
44871b1b CM |
3631 | return ret; |
3632 | } | |
3633 | ||
3634 | /* | |
3635 | * Given a key and some data, insert items into the tree. | |
3636 | * This does all the path init required, making room in the tree if needed. | |
3637 | */ | |
3638 | int btrfs_insert_empty_items(struct btrfs_trans_handle *trans, | |
3639 | struct btrfs_root *root, | |
3640 | struct btrfs_path *path, | |
3641 | struct btrfs_key *cpu_key, u32 *data_size, | |
3642 | int nr) | |
3643 | { | |
44871b1b CM |
3644 | int ret = 0; |
3645 | int slot; | |
3646 | int i; | |
3647 | u32 total_size = 0; | |
3648 | u32 total_data = 0; | |
3649 | ||
3650 | for (i = 0; i < nr; i++) | |
3651 | total_data += data_size[i]; | |
3652 | ||
3653 | total_size = total_data + (nr * sizeof(struct btrfs_item)); | |
3654 | ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1); | |
3655 | if (ret == 0) | |
3656 | return -EEXIST; | |
3657 | if (ret < 0) | |
3658 | goto out; | |
3659 | ||
44871b1b CM |
3660 | slot = path->slots[0]; |
3661 | BUG_ON(slot < 0); | |
3662 | ||
3663 | ret = setup_items_for_insert(trans, root, path, cpu_key, data_size, | |
3664 | total_data, total_size, nr); | |
3665 | ||
ed2ff2cb | 3666 | out: |
62e2749e CM |
3667 | return ret; |
3668 | } | |
3669 | ||
3670 | /* | |
3671 | * Given a key and some data, insert an item into the tree. | |
3672 | * This does all the path init required, making room in the tree if needed. | |
3673 | */ | |
e089f05c CM |
3674 | int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root |
3675 | *root, struct btrfs_key *cpu_key, void *data, u32 | |
3676 | data_size) | |
62e2749e CM |
3677 | { |
3678 | int ret = 0; | |
2c90e5d6 | 3679 | struct btrfs_path *path; |
5f39d397 CM |
3680 | struct extent_buffer *leaf; |
3681 | unsigned long ptr; | |
62e2749e | 3682 | |
2c90e5d6 | 3683 | path = btrfs_alloc_path(); |
db5b493a TI |
3684 | if (!path) |
3685 | return -ENOMEM; | |
2c90e5d6 | 3686 | ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size); |
62e2749e | 3687 | if (!ret) { |
5f39d397 CM |
3688 | leaf = path->nodes[0]; |
3689 | ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); | |
3690 | write_extent_buffer(leaf, data, ptr, data_size); | |
3691 | btrfs_mark_buffer_dirty(leaf); | |
62e2749e | 3692 | } |
2c90e5d6 | 3693 | btrfs_free_path(path); |
aa5d6bed | 3694 | return ret; |
be0e5c09 CM |
3695 | } |
3696 | ||
74123bd7 | 3697 | /* |
5de08d7d | 3698 | * delete the pointer from a given node. |
74123bd7 | 3699 | * |
d352ac68 CM |
3700 | * the tree should have been previously balanced so the deletion does not |
3701 | * empty a node. | |
74123bd7 | 3702 | */ |
e089f05c CM |
3703 | static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
3704 | struct btrfs_path *path, int level, int slot) | |
be0e5c09 | 3705 | { |
5f39d397 | 3706 | struct extent_buffer *parent = path->nodes[level]; |
7518a238 | 3707 | u32 nritems; |
aa5d6bed | 3708 | int ret = 0; |
bb803951 | 3709 | int wret; |
be0e5c09 | 3710 | |
5f39d397 | 3711 | nritems = btrfs_header_nritems(parent); |
d397712b | 3712 | if (slot != nritems - 1) { |
5f39d397 CM |
3713 | memmove_extent_buffer(parent, |
3714 | btrfs_node_key_ptr_offset(slot), | |
3715 | btrfs_node_key_ptr_offset(slot + 1), | |
d6025579 CM |
3716 | sizeof(struct btrfs_key_ptr) * |
3717 | (nritems - slot - 1)); | |
bb803951 | 3718 | } |
7518a238 | 3719 | nritems--; |
5f39d397 | 3720 | btrfs_set_header_nritems(parent, nritems); |
7518a238 | 3721 | if (nritems == 0 && parent == root->node) { |
5f39d397 | 3722 | BUG_ON(btrfs_header_level(root->node) != 1); |
bb803951 | 3723 | /* just turn the root into a leaf and break */ |
5f39d397 | 3724 | btrfs_set_header_level(root->node, 0); |
bb803951 | 3725 | } else if (slot == 0) { |
5f39d397 CM |
3726 | struct btrfs_disk_key disk_key; |
3727 | ||
3728 | btrfs_node_key(parent, &disk_key, 0); | |
3729 | wret = fixup_low_keys(trans, root, path, &disk_key, level + 1); | |
0f70abe2 CM |
3730 | if (wret) |
3731 | ret = wret; | |
be0e5c09 | 3732 | } |
d6025579 | 3733 | btrfs_mark_buffer_dirty(parent); |
aa5d6bed | 3734 | return ret; |
be0e5c09 CM |
3735 | } |
3736 | ||
323ac95b CM |
3737 | /* |
3738 | * a helper function to delete the leaf pointed to by path->slots[1] and | |
5d4f98a2 | 3739 | * path->nodes[1]. |
323ac95b CM |
3740 | * |
3741 | * This deletes the pointer in path->nodes[1] and frees the leaf | |
3742 | * block extent. zero is returned if it all worked out, < 0 otherwise. | |
3743 | * | |
3744 | * The path must have already been setup for deleting the leaf, including | |
3745 | * all the proper balancing. path->nodes[1] must be locked. | |
3746 | */ | |
5d4f98a2 YZ |
3747 | static noinline int btrfs_del_leaf(struct btrfs_trans_handle *trans, |
3748 | struct btrfs_root *root, | |
3749 | struct btrfs_path *path, | |
3750 | struct extent_buffer *leaf) | |
323ac95b CM |
3751 | { |
3752 | int ret; | |
323ac95b | 3753 | |
5d4f98a2 | 3754 | WARN_ON(btrfs_header_generation(leaf) != trans->transid); |
323ac95b CM |
3755 | ret = del_ptr(trans, root, path, 1, path->slots[1]); |
3756 | if (ret) | |
3757 | return ret; | |
3758 | ||
4d081c41 CM |
3759 | /* |
3760 | * btrfs_free_extent is expensive, we want to make sure we | |
3761 | * aren't holding any locks when we call it | |
3762 | */ | |
3763 | btrfs_unlock_up_safe(path, 0); | |
3764 | ||
f0486c68 YZ |
3765 | root_sub_used(root, leaf->len); |
3766 | ||
3767 | btrfs_free_tree_block(trans, root, leaf, 0, 1); | |
3768 | return 0; | |
323ac95b | 3769 | } |
74123bd7 CM |
3770 | /* |
3771 | * delete the item at the leaf level in path. If that empties | |
3772 | * the leaf, remove it from the tree | |
3773 | */ | |
85e21bac CM |
3774 | int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
3775 | struct btrfs_path *path, int slot, int nr) | |
be0e5c09 | 3776 | { |
5f39d397 CM |
3777 | struct extent_buffer *leaf; |
3778 | struct btrfs_item *item; | |
85e21bac CM |
3779 | int last_off; |
3780 | int dsize = 0; | |
aa5d6bed CM |
3781 | int ret = 0; |
3782 | int wret; | |
85e21bac | 3783 | int i; |
7518a238 | 3784 | u32 nritems; |
be0e5c09 | 3785 | |
5f39d397 | 3786 | leaf = path->nodes[0]; |
85e21bac CM |
3787 | last_off = btrfs_item_offset_nr(leaf, slot + nr - 1); |
3788 | ||
3789 | for (i = 0; i < nr; i++) | |
3790 | dsize += btrfs_item_size_nr(leaf, slot + i); | |
3791 | ||
5f39d397 | 3792 | nritems = btrfs_header_nritems(leaf); |
be0e5c09 | 3793 | |
85e21bac | 3794 | if (slot + nr != nritems) { |
123abc88 | 3795 | int data_end = leaf_data_end(root, leaf); |
5f39d397 CM |
3796 | |
3797 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + | |
d6025579 CM |
3798 | data_end + dsize, |
3799 | btrfs_leaf_data(leaf) + data_end, | |
85e21bac | 3800 | last_off - data_end); |
5f39d397 | 3801 | |
85e21bac | 3802 | for (i = slot + nr; i < nritems; i++) { |
5f39d397 | 3803 | u32 ioff; |
db94535d | 3804 | |
5f39d397 CM |
3805 | item = btrfs_item_nr(leaf, i); |
3806 | ioff = btrfs_item_offset(leaf, item); | |
3807 | btrfs_set_item_offset(leaf, item, ioff + dsize); | |
0783fcfc | 3808 | } |
db94535d | 3809 | |
5f39d397 | 3810 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot), |
85e21bac | 3811 | btrfs_item_nr_offset(slot + nr), |
d6025579 | 3812 | sizeof(struct btrfs_item) * |
85e21bac | 3813 | (nritems - slot - nr)); |
be0e5c09 | 3814 | } |
85e21bac CM |
3815 | btrfs_set_header_nritems(leaf, nritems - nr); |
3816 | nritems -= nr; | |
5f39d397 | 3817 | |
74123bd7 | 3818 | /* delete the leaf if we've emptied it */ |
7518a238 | 3819 | if (nritems == 0) { |
5f39d397 CM |
3820 | if (leaf == root->node) { |
3821 | btrfs_set_header_level(leaf, 0); | |
9a8dd150 | 3822 | } else { |
f0486c68 YZ |
3823 | btrfs_set_path_blocking(path); |
3824 | clean_tree_block(trans, root, leaf); | |
5d4f98a2 | 3825 | ret = btrfs_del_leaf(trans, root, path, leaf); |
323ac95b | 3826 | BUG_ON(ret); |
9a8dd150 | 3827 | } |
be0e5c09 | 3828 | } else { |
7518a238 | 3829 | int used = leaf_space_used(leaf, 0, nritems); |
aa5d6bed | 3830 | if (slot == 0) { |
5f39d397 CM |
3831 | struct btrfs_disk_key disk_key; |
3832 | ||
3833 | btrfs_item_key(leaf, &disk_key, 0); | |
e089f05c | 3834 | wret = fixup_low_keys(trans, root, path, |
5f39d397 | 3835 | &disk_key, 1); |
aa5d6bed CM |
3836 | if (wret) |
3837 | ret = wret; | |
3838 | } | |
aa5d6bed | 3839 | |
74123bd7 | 3840 | /* delete the leaf if it is mostly empty */ |
d717aa1d | 3841 | if (used < BTRFS_LEAF_DATA_SIZE(root) / 3) { |
be0e5c09 CM |
3842 | /* push_leaf_left fixes the path. |
3843 | * make sure the path still points to our leaf | |
3844 | * for possible call to del_ptr below | |
3845 | */ | |
4920c9ac | 3846 | slot = path->slots[1]; |
5f39d397 CM |
3847 | extent_buffer_get(leaf); |
3848 | ||
b9473439 | 3849 | btrfs_set_path_blocking(path); |
99d8f83c CM |
3850 | wret = push_leaf_left(trans, root, path, 1, 1, |
3851 | 1, (u32)-1); | |
54aa1f4d | 3852 | if (wret < 0 && wret != -ENOSPC) |
aa5d6bed | 3853 | ret = wret; |
5f39d397 CM |
3854 | |
3855 | if (path->nodes[0] == leaf && | |
3856 | btrfs_header_nritems(leaf)) { | |
99d8f83c CM |
3857 | wret = push_leaf_right(trans, root, path, 1, |
3858 | 1, 1, 0); | |
54aa1f4d | 3859 | if (wret < 0 && wret != -ENOSPC) |
aa5d6bed CM |
3860 | ret = wret; |
3861 | } | |
5f39d397 CM |
3862 | |
3863 | if (btrfs_header_nritems(leaf) == 0) { | |
323ac95b | 3864 | path->slots[1] = slot; |
5d4f98a2 | 3865 | ret = btrfs_del_leaf(trans, root, path, leaf); |
323ac95b | 3866 | BUG_ON(ret); |
5f39d397 | 3867 | free_extent_buffer(leaf); |
5de08d7d | 3868 | } else { |
925baedd CM |
3869 | /* if we're still in the path, make sure |
3870 | * we're dirty. Otherwise, one of the | |
3871 | * push_leaf functions must have already | |
3872 | * dirtied this buffer | |
3873 | */ | |
3874 | if (path->nodes[0] == leaf) | |
3875 | btrfs_mark_buffer_dirty(leaf); | |
5f39d397 | 3876 | free_extent_buffer(leaf); |
be0e5c09 | 3877 | } |
d5719762 | 3878 | } else { |
5f39d397 | 3879 | btrfs_mark_buffer_dirty(leaf); |
be0e5c09 CM |
3880 | } |
3881 | } | |
aa5d6bed | 3882 | return ret; |
be0e5c09 CM |
3883 | } |
3884 | ||
7bb86316 | 3885 | /* |
925baedd | 3886 | * search the tree again to find a leaf with lesser keys |
7bb86316 CM |
3887 | * returns 0 if it found something or 1 if there are no lesser leaves. |
3888 | * returns < 0 on io errors. | |
d352ac68 CM |
3889 | * |
3890 | * This may release the path, and so you may lose any locks held at the | |
3891 | * time you call it. | |
7bb86316 CM |
3892 | */ |
3893 | int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path) | |
3894 | { | |
925baedd CM |
3895 | struct btrfs_key key; |
3896 | struct btrfs_disk_key found_key; | |
3897 | int ret; | |
7bb86316 | 3898 | |
925baedd | 3899 | btrfs_item_key_to_cpu(path->nodes[0], &key, 0); |
7bb86316 | 3900 | |
925baedd CM |
3901 | if (key.offset > 0) |
3902 | key.offset--; | |
3903 | else if (key.type > 0) | |
3904 | key.type--; | |
3905 | else if (key.objectid > 0) | |
3906 | key.objectid--; | |
3907 | else | |
3908 | return 1; | |
7bb86316 | 3909 | |
b3b4aa74 | 3910 | btrfs_release_path(path); |
925baedd CM |
3911 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
3912 | if (ret < 0) | |
3913 | return ret; | |
3914 | btrfs_item_key(path->nodes[0], &found_key, 0); | |
3915 | ret = comp_keys(&found_key, &key); | |
3916 | if (ret < 0) | |
3917 | return 0; | |
3918 | return 1; | |
7bb86316 CM |
3919 | } |
3920 | ||
3f157a2f CM |
3921 | /* |
3922 | * A helper function to walk down the tree starting at min_key, and looking | |
3923 | * for nodes or leaves that are either in cache or have a minimum | |
d352ac68 | 3924 | * transaction id. This is used by the btree defrag code, and tree logging |
3f157a2f CM |
3925 | * |
3926 | * This does not cow, but it does stuff the starting key it finds back | |
3927 | * into min_key, so you can call btrfs_search_slot with cow=1 on the | |
3928 | * key and get a writable path. | |
3929 | * | |
3930 | * This does lock as it descends, and path->keep_locks should be set | |
3931 | * to 1 by the caller. | |
3932 | * | |
3933 | * This honors path->lowest_level to prevent descent past a given level | |
3934 | * of the tree. | |
3935 | * | |
d352ac68 CM |
3936 | * min_trans indicates the oldest transaction that you are interested |
3937 | * in walking through. Any nodes or leaves older than min_trans are | |
3938 | * skipped over (without reading them). | |
3939 | * | |
3f157a2f CM |
3940 | * returns zero if something useful was found, < 0 on error and 1 if there |
3941 | * was nothing in the tree that matched the search criteria. | |
3942 | */ | |
3943 | int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key, | |
e02119d5 | 3944 | struct btrfs_key *max_key, |
3f157a2f CM |
3945 | struct btrfs_path *path, int cache_only, |
3946 | u64 min_trans) | |
3947 | { | |
3948 | struct extent_buffer *cur; | |
3949 | struct btrfs_key found_key; | |
3950 | int slot; | |
9652480b | 3951 | int sret; |
3f157a2f CM |
3952 | u32 nritems; |
3953 | int level; | |
3954 | int ret = 1; | |
3955 | ||
934d375b | 3956 | WARN_ON(!path->keep_locks); |
3f157a2f | 3957 | again: |
bd681513 | 3958 | cur = btrfs_read_lock_root_node(root); |
3f157a2f | 3959 | level = btrfs_header_level(cur); |
e02119d5 | 3960 | WARN_ON(path->nodes[level]); |
3f157a2f | 3961 | path->nodes[level] = cur; |
bd681513 | 3962 | path->locks[level] = BTRFS_READ_LOCK; |
3f157a2f CM |
3963 | |
3964 | if (btrfs_header_generation(cur) < min_trans) { | |
3965 | ret = 1; | |
3966 | goto out; | |
3967 | } | |
d397712b | 3968 | while (1) { |
3f157a2f CM |
3969 | nritems = btrfs_header_nritems(cur); |
3970 | level = btrfs_header_level(cur); | |
9652480b | 3971 | sret = bin_search(cur, min_key, level, &slot); |
3f157a2f | 3972 | |
323ac95b CM |
3973 | /* at the lowest level, we're done, setup the path and exit */ |
3974 | if (level == path->lowest_level) { | |
e02119d5 CM |
3975 | if (slot >= nritems) |
3976 | goto find_next_key; | |
3f157a2f CM |
3977 | ret = 0; |
3978 | path->slots[level] = slot; | |
3979 | btrfs_item_key_to_cpu(cur, &found_key, slot); | |
3980 | goto out; | |
3981 | } | |
9652480b Y |
3982 | if (sret && slot > 0) |
3983 | slot--; | |
3f157a2f CM |
3984 | /* |
3985 | * check this node pointer against the cache_only and | |
3986 | * min_trans parameters. If it isn't in cache or is too | |
3987 | * old, skip to the next one. | |
3988 | */ | |
d397712b | 3989 | while (slot < nritems) { |
3f157a2f CM |
3990 | u64 blockptr; |
3991 | u64 gen; | |
3992 | struct extent_buffer *tmp; | |
e02119d5 CM |
3993 | struct btrfs_disk_key disk_key; |
3994 | ||
3f157a2f CM |
3995 | blockptr = btrfs_node_blockptr(cur, slot); |
3996 | gen = btrfs_node_ptr_generation(cur, slot); | |
3997 | if (gen < min_trans) { | |
3998 | slot++; | |
3999 | continue; | |
4000 | } | |
4001 | if (!cache_only) | |
4002 | break; | |
4003 | ||
e02119d5 CM |
4004 | if (max_key) { |
4005 | btrfs_node_key(cur, &disk_key, slot); | |
4006 | if (comp_keys(&disk_key, max_key) >= 0) { | |
4007 | ret = 1; | |
4008 | goto out; | |
4009 | } | |
4010 | } | |
4011 | ||
3f157a2f CM |
4012 | tmp = btrfs_find_tree_block(root, blockptr, |
4013 | btrfs_level_size(root, level - 1)); | |
4014 | ||
4015 | if (tmp && btrfs_buffer_uptodate(tmp, gen)) { | |
4016 | free_extent_buffer(tmp); | |
4017 | break; | |
4018 | } | |
4019 | if (tmp) | |
4020 | free_extent_buffer(tmp); | |
4021 | slot++; | |
4022 | } | |
e02119d5 | 4023 | find_next_key: |
3f157a2f CM |
4024 | /* |
4025 | * we didn't find a candidate key in this node, walk forward | |
4026 | * and find another one | |
4027 | */ | |
4028 | if (slot >= nritems) { | |
e02119d5 | 4029 | path->slots[level] = slot; |
b4ce94de | 4030 | btrfs_set_path_blocking(path); |
e02119d5 | 4031 | sret = btrfs_find_next_key(root, path, min_key, level, |
3f157a2f | 4032 | cache_only, min_trans); |
e02119d5 | 4033 | if (sret == 0) { |
b3b4aa74 | 4034 | btrfs_release_path(path); |
3f157a2f CM |
4035 | goto again; |
4036 | } else { | |
4037 | goto out; | |
4038 | } | |
4039 | } | |
4040 | /* save our key for returning back */ | |
4041 | btrfs_node_key_to_cpu(cur, &found_key, slot); | |
4042 | path->slots[level] = slot; | |
4043 | if (level == path->lowest_level) { | |
4044 | ret = 0; | |
4045 | unlock_up(path, level, 1); | |
4046 | goto out; | |
4047 | } | |
b4ce94de | 4048 | btrfs_set_path_blocking(path); |
3f157a2f | 4049 | cur = read_node_slot(root, cur, slot); |
97d9a8a4 | 4050 | BUG_ON(!cur); |
3f157a2f | 4051 | |
bd681513 | 4052 | btrfs_tree_read_lock(cur); |
b4ce94de | 4053 | |
bd681513 | 4054 | path->locks[level - 1] = BTRFS_READ_LOCK; |
3f157a2f CM |
4055 | path->nodes[level - 1] = cur; |
4056 | unlock_up(path, level, 1); | |
bd681513 | 4057 | btrfs_clear_path_blocking(path, NULL, 0); |
3f157a2f CM |
4058 | } |
4059 | out: | |
4060 | if (ret == 0) | |
4061 | memcpy(min_key, &found_key, sizeof(found_key)); | |
b4ce94de | 4062 | btrfs_set_path_blocking(path); |
3f157a2f CM |
4063 | return ret; |
4064 | } | |
4065 | ||
4066 | /* | |
4067 | * this is similar to btrfs_next_leaf, but does not try to preserve | |
4068 | * and fixup the path. It looks for and returns the next key in the | |
4069 | * tree based on the current path and the cache_only and min_trans | |
4070 | * parameters. | |
4071 | * | |
4072 | * 0 is returned if another key is found, < 0 if there are any errors | |
4073 | * and 1 is returned if there are no higher keys in the tree | |
4074 | * | |
4075 | * path->keep_locks should be set to 1 on the search made before | |
4076 | * calling this function. | |
4077 | */ | |
e7a84565 | 4078 | int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path, |
33c66f43 | 4079 | struct btrfs_key *key, int level, |
3f157a2f | 4080 | int cache_only, u64 min_trans) |
e7a84565 | 4081 | { |
e7a84565 CM |
4082 | int slot; |
4083 | struct extent_buffer *c; | |
4084 | ||
934d375b | 4085 | WARN_ON(!path->keep_locks); |
d397712b | 4086 | while (level < BTRFS_MAX_LEVEL) { |
e7a84565 CM |
4087 | if (!path->nodes[level]) |
4088 | return 1; | |
4089 | ||
4090 | slot = path->slots[level] + 1; | |
4091 | c = path->nodes[level]; | |
3f157a2f | 4092 | next: |
e7a84565 | 4093 | if (slot >= btrfs_header_nritems(c)) { |
33c66f43 YZ |
4094 | int ret; |
4095 | int orig_lowest; | |
4096 | struct btrfs_key cur_key; | |
4097 | if (level + 1 >= BTRFS_MAX_LEVEL || | |
4098 | !path->nodes[level + 1]) | |
e7a84565 | 4099 | return 1; |
33c66f43 YZ |
4100 | |
4101 | if (path->locks[level + 1]) { | |
4102 | level++; | |
4103 | continue; | |
4104 | } | |
4105 | ||
4106 | slot = btrfs_header_nritems(c) - 1; | |
4107 | if (level == 0) | |
4108 | btrfs_item_key_to_cpu(c, &cur_key, slot); | |
4109 | else | |
4110 | btrfs_node_key_to_cpu(c, &cur_key, slot); | |
4111 | ||
4112 | orig_lowest = path->lowest_level; | |
b3b4aa74 | 4113 | btrfs_release_path(path); |
33c66f43 YZ |
4114 | path->lowest_level = level; |
4115 | ret = btrfs_search_slot(NULL, root, &cur_key, path, | |
4116 | 0, 0); | |
4117 | path->lowest_level = orig_lowest; | |
4118 | if (ret < 0) | |
4119 | return ret; | |
4120 | ||
4121 | c = path->nodes[level]; | |
4122 | slot = path->slots[level]; | |
4123 | if (ret == 0) | |
4124 | slot++; | |
4125 | goto next; | |
e7a84565 | 4126 | } |
33c66f43 | 4127 | |
e7a84565 CM |
4128 | if (level == 0) |
4129 | btrfs_item_key_to_cpu(c, key, slot); | |
3f157a2f CM |
4130 | else { |
4131 | u64 blockptr = btrfs_node_blockptr(c, slot); | |
4132 | u64 gen = btrfs_node_ptr_generation(c, slot); | |
4133 | ||
4134 | if (cache_only) { | |
4135 | struct extent_buffer *cur; | |
4136 | cur = btrfs_find_tree_block(root, blockptr, | |
4137 | btrfs_level_size(root, level - 1)); | |
4138 | if (!cur || !btrfs_buffer_uptodate(cur, gen)) { | |
4139 | slot++; | |
4140 | if (cur) | |
4141 | free_extent_buffer(cur); | |
4142 | goto next; | |
4143 | } | |
4144 | free_extent_buffer(cur); | |
4145 | } | |
4146 | if (gen < min_trans) { | |
4147 | slot++; | |
4148 | goto next; | |
4149 | } | |
e7a84565 | 4150 | btrfs_node_key_to_cpu(c, key, slot); |
3f157a2f | 4151 | } |
e7a84565 CM |
4152 | return 0; |
4153 | } | |
4154 | return 1; | |
4155 | } | |
4156 | ||
97571fd0 | 4157 | /* |
925baedd | 4158 | * search the tree again to find a leaf with greater keys |
0f70abe2 CM |
4159 | * returns 0 if it found something or 1 if there are no greater leaves. |
4160 | * returns < 0 on io errors. | |
97571fd0 | 4161 | */ |
234b63a0 | 4162 | int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path) |
d97e63b6 CM |
4163 | { |
4164 | int slot; | |
8e73f275 | 4165 | int level; |
5f39d397 | 4166 | struct extent_buffer *c; |
8e73f275 | 4167 | struct extent_buffer *next; |
925baedd CM |
4168 | struct btrfs_key key; |
4169 | u32 nritems; | |
4170 | int ret; | |
8e73f275 | 4171 | int old_spinning = path->leave_spinning; |
bd681513 | 4172 | int next_rw_lock = 0; |
925baedd CM |
4173 | |
4174 | nritems = btrfs_header_nritems(path->nodes[0]); | |
d397712b | 4175 | if (nritems == 0) |
925baedd | 4176 | return 1; |
925baedd | 4177 | |
8e73f275 CM |
4178 | btrfs_item_key_to_cpu(path->nodes[0], &key, nritems - 1); |
4179 | again: | |
4180 | level = 1; | |
4181 | next = NULL; | |
bd681513 | 4182 | next_rw_lock = 0; |
b3b4aa74 | 4183 | btrfs_release_path(path); |
8e73f275 | 4184 | |
a2135011 | 4185 | path->keep_locks = 1; |
31533fb2 | 4186 | path->leave_spinning = 1; |
8e73f275 | 4187 | |
925baedd CM |
4188 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
4189 | path->keep_locks = 0; | |
4190 | ||
4191 | if (ret < 0) | |
4192 | return ret; | |
4193 | ||
a2135011 | 4194 | nritems = btrfs_header_nritems(path->nodes[0]); |
168fd7d2 CM |
4195 | /* |
4196 | * by releasing the path above we dropped all our locks. A balance | |
4197 | * could have added more items next to the key that used to be | |
4198 | * at the very end of the block. So, check again here and | |
4199 | * advance the path if there are now more items available. | |
4200 | */ | |
a2135011 | 4201 | if (nritems > 0 && path->slots[0] < nritems - 1) { |
e457afec YZ |
4202 | if (ret == 0) |
4203 | path->slots[0]++; | |
8e73f275 | 4204 | ret = 0; |
925baedd CM |
4205 | goto done; |
4206 | } | |
d97e63b6 | 4207 | |
d397712b | 4208 | while (level < BTRFS_MAX_LEVEL) { |
8e73f275 CM |
4209 | if (!path->nodes[level]) { |
4210 | ret = 1; | |
4211 | goto done; | |
4212 | } | |
5f39d397 | 4213 | |
d97e63b6 CM |
4214 | slot = path->slots[level] + 1; |
4215 | c = path->nodes[level]; | |
5f39d397 | 4216 | if (slot >= btrfs_header_nritems(c)) { |
d97e63b6 | 4217 | level++; |
8e73f275 CM |
4218 | if (level == BTRFS_MAX_LEVEL) { |
4219 | ret = 1; | |
4220 | goto done; | |
4221 | } | |
d97e63b6 CM |
4222 | continue; |
4223 | } | |
5f39d397 | 4224 | |
925baedd | 4225 | if (next) { |
bd681513 | 4226 | btrfs_tree_unlock_rw(next, next_rw_lock); |
5f39d397 | 4227 | free_extent_buffer(next); |
925baedd | 4228 | } |
5f39d397 | 4229 | |
8e73f275 | 4230 | next = c; |
bd681513 | 4231 | next_rw_lock = path->locks[level]; |
8e73f275 CM |
4232 | ret = read_block_for_search(NULL, root, path, &next, level, |
4233 | slot, &key); | |
4234 | if (ret == -EAGAIN) | |
4235 | goto again; | |
5f39d397 | 4236 | |
76a05b35 | 4237 | if (ret < 0) { |
b3b4aa74 | 4238 | btrfs_release_path(path); |
76a05b35 CM |
4239 | goto done; |
4240 | } | |
4241 | ||
5cd57b2c | 4242 | if (!path->skip_locking) { |
bd681513 | 4243 | ret = btrfs_try_tree_read_lock(next); |
8e73f275 CM |
4244 | if (!ret) { |
4245 | btrfs_set_path_blocking(path); | |
bd681513 | 4246 | btrfs_tree_read_lock(next); |
31533fb2 | 4247 | btrfs_clear_path_blocking(path, next, |
bd681513 | 4248 | BTRFS_READ_LOCK); |
8e73f275 | 4249 | } |
31533fb2 | 4250 | next_rw_lock = BTRFS_READ_LOCK; |
5cd57b2c | 4251 | } |
d97e63b6 CM |
4252 | break; |
4253 | } | |
4254 | path->slots[level] = slot; | |
d397712b | 4255 | while (1) { |
d97e63b6 CM |
4256 | level--; |
4257 | c = path->nodes[level]; | |
925baedd | 4258 | if (path->locks[level]) |
bd681513 | 4259 | btrfs_tree_unlock_rw(c, path->locks[level]); |
8e73f275 | 4260 | |
5f39d397 | 4261 | free_extent_buffer(c); |
d97e63b6 CM |
4262 | path->nodes[level] = next; |
4263 | path->slots[level] = 0; | |
a74a4b97 | 4264 | if (!path->skip_locking) |
bd681513 | 4265 | path->locks[level] = next_rw_lock; |
d97e63b6 CM |
4266 | if (!level) |
4267 | break; | |
b4ce94de | 4268 | |
8e73f275 CM |
4269 | ret = read_block_for_search(NULL, root, path, &next, level, |
4270 | 0, &key); | |
4271 | if (ret == -EAGAIN) | |
4272 | goto again; | |
4273 | ||
76a05b35 | 4274 | if (ret < 0) { |
b3b4aa74 | 4275 | btrfs_release_path(path); |
76a05b35 CM |
4276 | goto done; |
4277 | } | |
4278 | ||
5cd57b2c | 4279 | if (!path->skip_locking) { |
bd681513 | 4280 | ret = btrfs_try_tree_read_lock(next); |
8e73f275 CM |
4281 | if (!ret) { |
4282 | btrfs_set_path_blocking(path); | |
bd681513 | 4283 | btrfs_tree_read_lock(next); |
31533fb2 | 4284 | btrfs_clear_path_blocking(path, next, |
bd681513 CM |
4285 | BTRFS_READ_LOCK); |
4286 | } | |
31533fb2 | 4287 | next_rw_lock = BTRFS_READ_LOCK; |
5cd57b2c | 4288 | } |
d97e63b6 | 4289 | } |
8e73f275 | 4290 | ret = 0; |
925baedd CM |
4291 | done: |
4292 | unlock_up(path, 0, 1); | |
8e73f275 CM |
4293 | path->leave_spinning = old_spinning; |
4294 | if (!old_spinning) | |
4295 | btrfs_set_path_blocking(path); | |
4296 | ||
4297 | return ret; | |
d97e63b6 | 4298 | } |
0b86a832 | 4299 | |
3f157a2f CM |
4300 | /* |
4301 | * this uses btrfs_prev_leaf to walk backwards in the tree, and keeps | |
4302 | * searching until it gets past min_objectid or finds an item of 'type' | |
4303 | * | |
4304 | * returns 0 if something is found, 1 if nothing was found and < 0 on error | |
4305 | */ | |
0b86a832 CM |
4306 | int btrfs_previous_item(struct btrfs_root *root, |
4307 | struct btrfs_path *path, u64 min_objectid, | |
4308 | int type) | |
4309 | { | |
4310 | struct btrfs_key found_key; | |
4311 | struct extent_buffer *leaf; | |
e02119d5 | 4312 | u32 nritems; |
0b86a832 CM |
4313 | int ret; |
4314 | ||
d397712b | 4315 | while (1) { |
0b86a832 | 4316 | if (path->slots[0] == 0) { |
b4ce94de | 4317 | btrfs_set_path_blocking(path); |
0b86a832 CM |
4318 | ret = btrfs_prev_leaf(root, path); |
4319 | if (ret != 0) | |
4320 | return ret; | |
4321 | } else { | |
4322 | path->slots[0]--; | |
4323 | } | |
4324 | leaf = path->nodes[0]; | |
e02119d5 CM |
4325 | nritems = btrfs_header_nritems(leaf); |
4326 | if (nritems == 0) | |
4327 | return 1; | |
4328 | if (path->slots[0] == nritems) | |
4329 | path->slots[0]--; | |
4330 | ||
0b86a832 | 4331 | btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); |
e02119d5 CM |
4332 | if (found_key.objectid < min_objectid) |
4333 | break; | |
0a4eefbb YZ |
4334 | if (found_key.type == type) |
4335 | return 0; | |
e02119d5 CM |
4336 | if (found_key.objectid == min_objectid && |
4337 | found_key.type < type) | |
4338 | break; | |
0b86a832 CM |
4339 | } |
4340 | return 1; | |
4341 | } |