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6cbd5570 | 1 | /* |
d352ac68 | 2 | * Copyright (C) 2007,2008 Oracle. All rights reserved. |
6cbd5570 CM |
3 | * |
4 | * This program is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU General Public | |
6 | * License v2 as published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, | |
9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
11 | * General Public License for more details. | |
12 | * | |
13 | * You should have received a copy of the GNU General Public | |
14 | * License along with this program; if not, write to the | |
15 | * Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
16 | * Boston, MA 021110-1307, USA. | |
17 | */ | |
18 | ||
a6b6e75e | 19 | #include <linux/sched.h> |
5a0e3ad6 | 20 | #include <linux/slab.h> |
eb60ceac CM |
21 | #include "ctree.h" |
22 | #include "disk-io.h" | |
7f5c1516 | 23 | #include "transaction.h" |
5f39d397 | 24 | #include "print-tree.h" |
925baedd | 25 | #include "locking.h" |
9a8dd150 | 26 | |
e089f05c CM |
27 | static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root |
28 | *root, struct btrfs_path *path, int level); | |
29 | static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root | |
d4dbff95 | 30 | *root, struct btrfs_key *ins_key, |
cc0c5538 | 31 | struct btrfs_path *path, int data_size, int extend); |
5f39d397 CM |
32 | static int push_node_left(struct btrfs_trans_handle *trans, |
33 | struct btrfs_root *root, struct extent_buffer *dst, | |
971a1f66 | 34 | struct extent_buffer *src, int empty); |
5f39d397 CM |
35 | static int balance_node_right(struct btrfs_trans_handle *trans, |
36 | struct btrfs_root *root, | |
37 | struct extent_buffer *dst_buf, | |
38 | struct extent_buffer *src_buf); | |
e089f05c CM |
39 | static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
40 | struct btrfs_path *path, int level, int slot); | |
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 | |
a05a9bb1 | 905 | if (level < BTRFS_MAX_LEVEL - 1) { |
5f39d397 | 906 | parent = path->nodes[level + 1]; |
a05a9bb1 LZ |
907 | pslot = path->slots[level + 1]; |
908 | } | |
bb803951 | 909 | |
40689478 CM |
910 | /* |
911 | * deal with the case where there is only one pointer in the root | |
912 | * by promoting the node below to a root | |
913 | */ | |
5f39d397 CM |
914 | if (!parent) { |
915 | struct extent_buffer *child; | |
bb803951 | 916 | |
5f39d397 | 917 | if (btrfs_header_nritems(mid) != 1) |
bb803951 CM |
918 | return 0; |
919 | ||
920 | /* promote the child to a root */ | |
5f39d397 | 921 | child = read_node_slot(root, mid, 0); |
7951f3ce | 922 | BUG_ON(!child); |
925baedd | 923 | btrfs_tree_lock(child); |
b4ce94de | 924 | btrfs_set_lock_blocking(child); |
9fa8cfe7 | 925 | ret = btrfs_cow_block(trans, root, child, mid, 0, &child); |
f0486c68 YZ |
926 | if (ret) { |
927 | btrfs_tree_unlock(child); | |
928 | free_extent_buffer(child); | |
929 | goto enospc; | |
930 | } | |
2f375ab9 | 931 | |
240f62c8 | 932 | rcu_assign_pointer(root->node, child); |
925baedd | 933 | |
0b86a832 | 934 | add_root_to_dirty_list(root); |
925baedd | 935 | btrfs_tree_unlock(child); |
b4ce94de | 936 | |
925baedd | 937 | path->locks[level] = 0; |
bb803951 | 938 | path->nodes[level] = NULL; |
5f39d397 | 939 | clean_tree_block(trans, root, mid); |
925baedd | 940 | btrfs_tree_unlock(mid); |
bb803951 | 941 | /* once for the path */ |
5f39d397 | 942 | free_extent_buffer(mid); |
f0486c68 YZ |
943 | |
944 | root_sub_used(root, mid->len); | |
945 | btrfs_free_tree_block(trans, root, mid, 0, 1); | |
bb803951 | 946 | /* once for the root ptr */ |
5f39d397 | 947 | free_extent_buffer(mid); |
f0486c68 | 948 | return 0; |
bb803951 | 949 | } |
5f39d397 | 950 | if (btrfs_header_nritems(mid) > |
123abc88 | 951 | BTRFS_NODEPTRS_PER_BLOCK(root) / 4) |
bb803951 CM |
952 | return 0; |
953 | ||
559af821 | 954 | btrfs_header_nritems(mid); |
54aa1f4d | 955 | |
5f39d397 CM |
956 | left = read_node_slot(root, parent, pslot - 1); |
957 | if (left) { | |
925baedd | 958 | btrfs_tree_lock(left); |
b4ce94de | 959 | btrfs_set_lock_blocking(left); |
5f39d397 | 960 | wret = btrfs_cow_block(trans, root, left, |
9fa8cfe7 | 961 | parent, pslot - 1, &left); |
54aa1f4d CM |
962 | if (wret) { |
963 | ret = wret; | |
964 | goto enospc; | |
965 | } | |
2cc58cf2 | 966 | } |
5f39d397 CM |
967 | right = read_node_slot(root, parent, pslot + 1); |
968 | if (right) { | |
925baedd | 969 | btrfs_tree_lock(right); |
b4ce94de | 970 | btrfs_set_lock_blocking(right); |
5f39d397 | 971 | wret = btrfs_cow_block(trans, root, right, |
9fa8cfe7 | 972 | parent, pslot + 1, &right); |
2cc58cf2 CM |
973 | if (wret) { |
974 | ret = wret; | |
975 | goto enospc; | |
976 | } | |
977 | } | |
978 | ||
979 | /* first, try to make some room in the middle buffer */ | |
5f39d397 CM |
980 | if (left) { |
981 | orig_slot += btrfs_header_nritems(left); | |
bce4eae9 | 982 | wret = push_node_left(trans, root, left, mid, 1); |
79f95c82 CM |
983 | if (wret < 0) |
984 | ret = wret; | |
559af821 | 985 | btrfs_header_nritems(mid); |
bb803951 | 986 | } |
79f95c82 CM |
987 | |
988 | /* | |
989 | * then try to empty the right most buffer into the middle | |
990 | */ | |
5f39d397 | 991 | if (right) { |
971a1f66 | 992 | wret = push_node_left(trans, root, mid, right, 1); |
54aa1f4d | 993 | if (wret < 0 && wret != -ENOSPC) |
79f95c82 | 994 | ret = wret; |
5f39d397 | 995 | if (btrfs_header_nritems(right) == 0) { |
5f39d397 | 996 | clean_tree_block(trans, root, right); |
925baedd | 997 | btrfs_tree_unlock(right); |
e089f05c CM |
998 | wret = del_ptr(trans, root, path, level + 1, pslot + |
999 | 1); | |
bb803951 CM |
1000 | if (wret) |
1001 | ret = wret; | |
f0486c68 YZ |
1002 | root_sub_used(root, right->len); |
1003 | btrfs_free_tree_block(trans, root, right, 0, 1); | |
1004 | free_extent_buffer(right); | |
1005 | right = NULL; | |
bb803951 | 1006 | } else { |
5f39d397 CM |
1007 | struct btrfs_disk_key right_key; |
1008 | btrfs_node_key(right, &right_key, 0); | |
1009 | btrfs_set_node_key(parent, &right_key, pslot + 1); | |
1010 | btrfs_mark_buffer_dirty(parent); | |
bb803951 CM |
1011 | } |
1012 | } | |
5f39d397 | 1013 | if (btrfs_header_nritems(mid) == 1) { |
79f95c82 CM |
1014 | /* |
1015 | * we're not allowed to leave a node with one item in the | |
1016 | * tree during a delete. A deletion from lower in the tree | |
1017 | * could try to delete the only pointer in this node. | |
1018 | * So, pull some keys from the left. | |
1019 | * There has to be a left pointer at this point because | |
1020 | * otherwise we would have pulled some pointers from the | |
1021 | * right | |
1022 | */ | |
5f39d397 CM |
1023 | BUG_ON(!left); |
1024 | wret = balance_node_right(trans, root, mid, left); | |
54aa1f4d | 1025 | if (wret < 0) { |
79f95c82 | 1026 | ret = wret; |
54aa1f4d CM |
1027 | goto enospc; |
1028 | } | |
bce4eae9 CM |
1029 | if (wret == 1) { |
1030 | wret = push_node_left(trans, root, left, mid, 1); | |
1031 | if (wret < 0) | |
1032 | ret = wret; | |
1033 | } | |
79f95c82 CM |
1034 | BUG_ON(wret == 1); |
1035 | } | |
5f39d397 | 1036 | if (btrfs_header_nritems(mid) == 0) { |
5f39d397 | 1037 | clean_tree_block(trans, root, mid); |
925baedd | 1038 | btrfs_tree_unlock(mid); |
e089f05c | 1039 | wret = del_ptr(trans, root, path, level + 1, pslot); |
bb803951 CM |
1040 | if (wret) |
1041 | ret = wret; | |
f0486c68 YZ |
1042 | root_sub_used(root, mid->len); |
1043 | btrfs_free_tree_block(trans, root, mid, 0, 1); | |
1044 | free_extent_buffer(mid); | |
1045 | mid = NULL; | |
79f95c82 CM |
1046 | } else { |
1047 | /* update the parent key to reflect our changes */ | |
5f39d397 CM |
1048 | struct btrfs_disk_key mid_key; |
1049 | btrfs_node_key(mid, &mid_key, 0); | |
1050 | btrfs_set_node_key(parent, &mid_key, pslot); | |
1051 | btrfs_mark_buffer_dirty(parent); | |
79f95c82 | 1052 | } |
bb803951 | 1053 | |
79f95c82 | 1054 | /* update the path */ |
5f39d397 CM |
1055 | if (left) { |
1056 | if (btrfs_header_nritems(left) > orig_slot) { | |
1057 | extent_buffer_get(left); | |
925baedd | 1058 | /* left was locked after cow */ |
5f39d397 | 1059 | path->nodes[level] = left; |
bb803951 CM |
1060 | path->slots[level + 1] -= 1; |
1061 | path->slots[level] = orig_slot; | |
925baedd CM |
1062 | if (mid) { |
1063 | btrfs_tree_unlock(mid); | |
5f39d397 | 1064 | free_extent_buffer(mid); |
925baedd | 1065 | } |
bb803951 | 1066 | } else { |
5f39d397 | 1067 | orig_slot -= btrfs_header_nritems(left); |
bb803951 CM |
1068 | path->slots[level] = orig_slot; |
1069 | } | |
1070 | } | |
79f95c82 | 1071 | /* double check we haven't messed things up */ |
e20d96d6 | 1072 | if (orig_ptr != |
5f39d397 | 1073 | btrfs_node_blockptr(path->nodes[level], path->slots[level])) |
79f95c82 | 1074 | BUG(); |
54aa1f4d | 1075 | enospc: |
925baedd CM |
1076 | if (right) { |
1077 | btrfs_tree_unlock(right); | |
5f39d397 | 1078 | free_extent_buffer(right); |
925baedd CM |
1079 | } |
1080 | if (left) { | |
1081 | if (path->nodes[level] != left) | |
1082 | btrfs_tree_unlock(left); | |
5f39d397 | 1083 | free_extent_buffer(left); |
925baedd | 1084 | } |
bb803951 CM |
1085 | return ret; |
1086 | } | |
1087 | ||
d352ac68 CM |
1088 | /* Node balancing for insertion. Here we only split or push nodes around |
1089 | * when they are completely full. This is also done top down, so we | |
1090 | * have to be pessimistic. | |
1091 | */ | |
d397712b | 1092 | static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans, |
98ed5174 CM |
1093 | struct btrfs_root *root, |
1094 | struct btrfs_path *path, int level) | |
e66f709b | 1095 | { |
5f39d397 CM |
1096 | struct extent_buffer *right = NULL; |
1097 | struct extent_buffer *mid; | |
1098 | struct extent_buffer *left = NULL; | |
1099 | struct extent_buffer *parent = NULL; | |
e66f709b CM |
1100 | int ret = 0; |
1101 | int wret; | |
1102 | int pslot; | |
1103 | int orig_slot = path->slots[level]; | |
e66f709b CM |
1104 | |
1105 | if (level == 0) | |
1106 | return 1; | |
1107 | ||
5f39d397 | 1108 | mid = path->nodes[level]; |
7bb86316 | 1109 | WARN_ON(btrfs_header_generation(mid) != trans->transid); |
e66f709b | 1110 | |
a05a9bb1 | 1111 | if (level < BTRFS_MAX_LEVEL - 1) { |
5f39d397 | 1112 | parent = path->nodes[level + 1]; |
a05a9bb1 LZ |
1113 | pslot = path->slots[level + 1]; |
1114 | } | |
e66f709b | 1115 | |
5f39d397 | 1116 | if (!parent) |
e66f709b | 1117 | return 1; |
e66f709b | 1118 | |
5f39d397 | 1119 | left = read_node_slot(root, parent, pslot - 1); |
e66f709b CM |
1120 | |
1121 | /* first, try to make some room in the middle buffer */ | |
5f39d397 | 1122 | if (left) { |
e66f709b | 1123 | u32 left_nr; |
925baedd CM |
1124 | |
1125 | btrfs_tree_lock(left); | |
b4ce94de CM |
1126 | btrfs_set_lock_blocking(left); |
1127 | ||
5f39d397 | 1128 | left_nr = btrfs_header_nritems(left); |
33ade1f8 CM |
1129 | if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) { |
1130 | wret = 1; | |
1131 | } else { | |
5f39d397 | 1132 | ret = btrfs_cow_block(trans, root, left, parent, |
9fa8cfe7 | 1133 | pslot - 1, &left); |
54aa1f4d CM |
1134 | if (ret) |
1135 | wret = 1; | |
1136 | else { | |
54aa1f4d | 1137 | wret = push_node_left(trans, root, |
971a1f66 | 1138 | left, mid, 0); |
54aa1f4d | 1139 | } |
33ade1f8 | 1140 | } |
e66f709b CM |
1141 | if (wret < 0) |
1142 | ret = wret; | |
1143 | if (wret == 0) { | |
5f39d397 | 1144 | struct btrfs_disk_key disk_key; |
e66f709b | 1145 | orig_slot += left_nr; |
5f39d397 CM |
1146 | btrfs_node_key(mid, &disk_key, 0); |
1147 | btrfs_set_node_key(parent, &disk_key, pslot); | |
1148 | btrfs_mark_buffer_dirty(parent); | |
1149 | if (btrfs_header_nritems(left) > orig_slot) { | |
1150 | path->nodes[level] = left; | |
e66f709b CM |
1151 | path->slots[level + 1] -= 1; |
1152 | path->slots[level] = orig_slot; | |
925baedd | 1153 | btrfs_tree_unlock(mid); |
5f39d397 | 1154 | free_extent_buffer(mid); |
e66f709b CM |
1155 | } else { |
1156 | orig_slot -= | |
5f39d397 | 1157 | btrfs_header_nritems(left); |
e66f709b | 1158 | path->slots[level] = orig_slot; |
925baedd | 1159 | btrfs_tree_unlock(left); |
5f39d397 | 1160 | free_extent_buffer(left); |
e66f709b | 1161 | } |
e66f709b CM |
1162 | return 0; |
1163 | } | |
925baedd | 1164 | btrfs_tree_unlock(left); |
5f39d397 | 1165 | free_extent_buffer(left); |
e66f709b | 1166 | } |
925baedd | 1167 | right = read_node_slot(root, parent, pslot + 1); |
e66f709b CM |
1168 | |
1169 | /* | |
1170 | * then try to empty the right most buffer into the middle | |
1171 | */ | |
5f39d397 | 1172 | if (right) { |
33ade1f8 | 1173 | u32 right_nr; |
b4ce94de | 1174 | |
925baedd | 1175 | btrfs_tree_lock(right); |
b4ce94de CM |
1176 | btrfs_set_lock_blocking(right); |
1177 | ||
5f39d397 | 1178 | right_nr = btrfs_header_nritems(right); |
33ade1f8 CM |
1179 | if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) { |
1180 | wret = 1; | |
1181 | } else { | |
5f39d397 CM |
1182 | ret = btrfs_cow_block(trans, root, right, |
1183 | parent, pslot + 1, | |
9fa8cfe7 | 1184 | &right); |
54aa1f4d CM |
1185 | if (ret) |
1186 | wret = 1; | |
1187 | else { | |
54aa1f4d | 1188 | wret = balance_node_right(trans, root, |
5f39d397 | 1189 | right, mid); |
54aa1f4d | 1190 | } |
33ade1f8 | 1191 | } |
e66f709b CM |
1192 | if (wret < 0) |
1193 | ret = wret; | |
1194 | if (wret == 0) { | |
5f39d397 CM |
1195 | struct btrfs_disk_key disk_key; |
1196 | ||
1197 | btrfs_node_key(right, &disk_key, 0); | |
1198 | btrfs_set_node_key(parent, &disk_key, pslot + 1); | |
1199 | btrfs_mark_buffer_dirty(parent); | |
1200 | ||
1201 | if (btrfs_header_nritems(mid) <= orig_slot) { | |
1202 | path->nodes[level] = right; | |
e66f709b CM |
1203 | path->slots[level + 1] += 1; |
1204 | path->slots[level] = orig_slot - | |
5f39d397 | 1205 | btrfs_header_nritems(mid); |
925baedd | 1206 | btrfs_tree_unlock(mid); |
5f39d397 | 1207 | free_extent_buffer(mid); |
e66f709b | 1208 | } else { |
925baedd | 1209 | btrfs_tree_unlock(right); |
5f39d397 | 1210 | free_extent_buffer(right); |
e66f709b | 1211 | } |
e66f709b CM |
1212 | return 0; |
1213 | } | |
925baedd | 1214 | btrfs_tree_unlock(right); |
5f39d397 | 1215 | free_extent_buffer(right); |
e66f709b | 1216 | } |
e66f709b CM |
1217 | return 1; |
1218 | } | |
1219 | ||
3c69faec | 1220 | /* |
d352ac68 CM |
1221 | * readahead one full node of leaves, finding things that are close |
1222 | * to the block in 'slot', and triggering ra on them. | |
3c69faec | 1223 | */ |
c8c42864 CM |
1224 | static void reada_for_search(struct btrfs_root *root, |
1225 | struct btrfs_path *path, | |
1226 | int level, int slot, u64 objectid) | |
3c69faec | 1227 | { |
5f39d397 | 1228 | struct extent_buffer *node; |
01f46658 | 1229 | struct btrfs_disk_key disk_key; |
3c69faec | 1230 | u32 nritems; |
3c69faec | 1231 | u64 search; |
a7175319 | 1232 | u64 target; |
6b80053d | 1233 | u64 nread = 0; |
cb25c2ea | 1234 | u64 gen; |
3c69faec | 1235 | int direction = path->reada; |
5f39d397 | 1236 | struct extent_buffer *eb; |
6b80053d CM |
1237 | u32 nr; |
1238 | u32 blocksize; | |
1239 | u32 nscan = 0; | |
db94535d | 1240 | |
a6b6e75e | 1241 | if (level != 1) |
6702ed49 CM |
1242 | return; |
1243 | ||
1244 | if (!path->nodes[level]) | |
3c69faec CM |
1245 | return; |
1246 | ||
5f39d397 | 1247 | node = path->nodes[level]; |
925baedd | 1248 | |
3c69faec | 1249 | search = btrfs_node_blockptr(node, slot); |
6b80053d CM |
1250 | blocksize = btrfs_level_size(root, level - 1); |
1251 | eb = btrfs_find_tree_block(root, search, blocksize); | |
5f39d397 CM |
1252 | if (eb) { |
1253 | free_extent_buffer(eb); | |
3c69faec CM |
1254 | return; |
1255 | } | |
1256 | ||
a7175319 | 1257 | target = search; |
6b80053d | 1258 | |
5f39d397 | 1259 | nritems = btrfs_header_nritems(node); |
6b80053d | 1260 | nr = slot; |
25b8b936 | 1261 | |
d397712b | 1262 | while (1) { |
6b80053d CM |
1263 | if (direction < 0) { |
1264 | if (nr == 0) | |
1265 | break; | |
1266 | nr--; | |
1267 | } else if (direction > 0) { | |
1268 | nr++; | |
1269 | if (nr >= nritems) | |
1270 | break; | |
3c69faec | 1271 | } |
01f46658 CM |
1272 | if (path->reada < 0 && objectid) { |
1273 | btrfs_node_key(node, &disk_key, nr); | |
1274 | if (btrfs_disk_key_objectid(&disk_key) != objectid) | |
1275 | break; | |
1276 | } | |
6b80053d | 1277 | search = btrfs_node_blockptr(node, nr); |
a7175319 CM |
1278 | if ((search <= target && target - search <= 65536) || |
1279 | (search > target && search - target <= 65536)) { | |
cb25c2ea | 1280 | gen = btrfs_node_ptr_generation(node, nr); |
cb25c2ea | 1281 | readahead_tree_block(root, search, blocksize, gen); |
6b80053d CM |
1282 | nread += blocksize; |
1283 | } | |
1284 | nscan++; | |
a7175319 | 1285 | if ((nread > 65536 || nscan > 32)) |
6b80053d | 1286 | break; |
3c69faec CM |
1287 | } |
1288 | } | |
925baedd | 1289 | |
b4ce94de CM |
1290 | /* |
1291 | * returns -EAGAIN if it had to drop the path, or zero if everything was in | |
1292 | * cache | |
1293 | */ | |
1294 | static noinline int reada_for_balance(struct btrfs_root *root, | |
1295 | struct btrfs_path *path, int level) | |
1296 | { | |
1297 | int slot; | |
1298 | int nritems; | |
1299 | struct extent_buffer *parent; | |
1300 | struct extent_buffer *eb; | |
1301 | u64 gen; | |
1302 | u64 block1 = 0; | |
1303 | u64 block2 = 0; | |
1304 | int ret = 0; | |
1305 | int blocksize; | |
1306 | ||
8c594ea8 | 1307 | parent = path->nodes[level + 1]; |
b4ce94de CM |
1308 | if (!parent) |
1309 | return 0; | |
1310 | ||
1311 | nritems = btrfs_header_nritems(parent); | |
8c594ea8 | 1312 | slot = path->slots[level + 1]; |
b4ce94de CM |
1313 | blocksize = btrfs_level_size(root, level); |
1314 | ||
1315 | if (slot > 0) { | |
1316 | block1 = btrfs_node_blockptr(parent, slot - 1); | |
1317 | gen = btrfs_node_ptr_generation(parent, slot - 1); | |
1318 | eb = btrfs_find_tree_block(root, block1, blocksize); | |
1319 | if (eb && btrfs_buffer_uptodate(eb, gen)) | |
1320 | block1 = 0; | |
1321 | free_extent_buffer(eb); | |
1322 | } | |
8c594ea8 | 1323 | if (slot + 1 < nritems) { |
b4ce94de CM |
1324 | block2 = btrfs_node_blockptr(parent, slot + 1); |
1325 | gen = btrfs_node_ptr_generation(parent, slot + 1); | |
1326 | eb = btrfs_find_tree_block(root, block2, blocksize); | |
1327 | if (eb && btrfs_buffer_uptodate(eb, gen)) | |
1328 | block2 = 0; | |
1329 | free_extent_buffer(eb); | |
1330 | } | |
1331 | if (block1 || block2) { | |
1332 | ret = -EAGAIN; | |
8c594ea8 CM |
1333 | |
1334 | /* release the whole path */ | |
b3b4aa74 | 1335 | btrfs_release_path(path); |
8c594ea8 CM |
1336 | |
1337 | /* read the blocks */ | |
b4ce94de CM |
1338 | if (block1) |
1339 | readahead_tree_block(root, block1, blocksize, 0); | |
1340 | if (block2) | |
1341 | readahead_tree_block(root, block2, blocksize, 0); | |
1342 | ||
1343 | if (block1) { | |
1344 | eb = read_tree_block(root, block1, blocksize, 0); | |
1345 | free_extent_buffer(eb); | |
1346 | } | |
8c594ea8 | 1347 | if (block2) { |
b4ce94de CM |
1348 | eb = read_tree_block(root, block2, blocksize, 0); |
1349 | free_extent_buffer(eb); | |
1350 | } | |
1351 | } | |
1352 | return ret; | |
1353 | } | |
1354 | ||
1355 | ||
d352ac68 | 1356 | /* |
d397712b CM |
1357 | * when we walk down the tree, it is usually safe to unlock the higher layers |
1358 | * in the tree. The exceptions are when our path goes through slot 0, because | |
1359 | * operations on the tree might require changing key pointers higher up in the | |
1360 | * tree. | |
d352ac68 | 1361 | * |
d397712b CM |
1362 | * callers might also have set path->keep_locks, which tells this code to keep |
1363 | * the lock if the path points to the last slot in the block. This is part of | |
1364 | * walking through the tree, and selecting the next slot in the higher block. | |
d352ac68 | 1365 | * |
d397712b CM |
1366 | * lowest_unlock sets the lowest level in the tree we're allowed to unlock. so |
1367 | * if lowest_unlock is 1, level 0 won't be unlocked | |
d352ac68 | 1368 | */ |
e02119d5 CM |
1369 | static noinline void unlock_up(struct btrfs_path *path, int level, |
1370 | int lowest_unlock) | |
925baedd CM |
1371 | { |
1372 | int i; | |
1373 | int skip_level = level; | |
051e1b9f | 1374 | int no_skips = 0; |
925baedd CM |
1375 | struct extent_buffer *t; |
1376 | ||
1377 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { | |
1378 | if (!path->nodes[i]) | |
1379 | break; | |
1380 | if (!path->locks[i]) | |
1381 | break; | |
051e1b9f | 1382 | if (!no_skips && path->slots[i] == 0) { |
925baedd CM |
1383 | skip_level = i + 1; |
1384 | continue; | |
1385 | } | |
051e1b9f | 1386 | if (!no_skips && path->keep_locks) { |
925baedd CM |
1387 | u32 nritems; |
1388 | t = path->nodes[i]; | |
1389 | nritems = btrfs_header_nritems(t); | |
051e1b9f | 1390 | if (nritems < 1 || path->slots[i] >= nritems - 1) { |
925baedd CM |
1391 | skip_level = i + 1; |
1392 | continue; | |
1393 | } | |
1394 | } | |
051e1b9f CM |
1395 | if (skip_level < i && i >= lowest_unlock) |
1396 | no_skips = 1; | |
1397 | ||
925baedd CM |
1398 | t = path->nodes[i]; |
1399 | if (i >= lowest_unlock && i > skip_level && path->locks[i]) { | |
bd681513 | 1400 | btrfs_tree_unlock_rw(t, path->locks[i]); |
925baedd CM |
1401 | path->locks[i] = 0; |
1402 | } | |
1403 | } | |
1404 | } | |
1405 | ||
b4ce94de CM |
1406 | /* |
1407 | * This releases any locks held in the path starting at level and | |
1408 | * going all the way up to the root. | |
1409 | * | |
1410 | * btrfs_search_slot will keep the lock held on higher nodes in a few | |
1411 | * corner cases, such as COW of the block at slot zero in the node. This | |
1412 | * ignores those rules, and it should only be called when there are no | |
1413 | * more updates to be done higher up in the tree. | |
1414 | */ | |
1415 | noinline void btrfs_unlock_up_safe(struct btrfs_path *path, int level) | |
1416 | { | |
1417 | int i; | |
1418 | ||
5d4f98a2 | 1419 | if (path->keep_locks) |
b4ce94de CM |
1420 | return; |
1421 | ||
1422 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { | |
1423 | if (!path->nodes[i]) | |
12f4dacc | 1424 | continue; |
b4ce94de | 1425 | if (!path->locks[i]) |
12f4dacc | 1426 | continue; |
bd681513 | 1427 | btrfs_tree_unlock_rw(path->nodes[i], path->locks[i]); |
b4ce94de CM |
1428 | path->locks[i] = 0; |
1429 | } | |
1430 | } | |
1431 | ||
c8c42864 CM |
1432 | /* |
1433 | * helper function for btrfs_search_slot. The goal is to find a block | |
1434 | * in cache without setting the path to blocking. If we find the block | |
1435 | * we return zero and the path is unchanged. | |
1436 | * | |
1437 | * If we can't find the block, we set the path blocking and do some | |
1438 | * reada. -EAGAIN is returned and the search must be repeated. | |
1439 | */ | |
1440 | static int | |
1441 | read_block_for_search(struct btrfs_trans_handle *trans, | |
1442 | struct btrfs_root *root, struct btrfs_path *p, | |
1443 | struct extent_buffer **eb_ret, int level, int slot, | |
1444 | struct btrfs_key *key) | |
1445 | { | |
1446 | u64 blocknr; | |
1447 | u64 gen; | |
1448 | u32 blocksize; | |
1449 | struct extent_buffer *b = *eb_ret; | |
1450 | struct extent_buffer *tmp; | |
76a05b35 | 1451 | int ret; |
c8c42864 CM |
1452 | |
1453 | blocknr = btrfs_node_blockptr(b, slot); | |
1454 | gen = btrfs_node_ptr_generation(b, slot); | |
1455 | blocksize = btrfs_level_size(root, level - 1); | |
1456 | ||
1457 | tmp = btrfs_find_tree_block(root, blocknr, blocksize); | |
cb44921a CM |
1458 | if (tmp) { |
1459 | if (btrfs_buffer_uptodate(tmp, 0)) { | |
1460 | if (btrfs_buffer_uptodate(tmp, gen)) { | |
1461 | /* | |
1462 | * we found an up to date block without | |
1463 | * sleeping, return | |
1464 | * right away | |
1465 | */ | |
1466 | *eb_ret = tmp; | |
1467 | return 0; | |
1468 | } | |
1469 | /* the pages were up to date, but we failed | |
1470 | * the generation number check. Do a full | |
1471 | * read for the generation number that is correct. | |
1472 | * We must do this without dropping locks so | |
1473 | * we can trust our generation number | |
1474 | */ | |
1475 | free_extent_buffer(tmp); | |
bd681513 CM |
1476 | btrfs_set_path_blocking(p); |
1477 | ||
cb44921a CM |
1478 | tmp = read_tree_block(root, blocknr, blocksize, gen); |
1479 | if (tmp && btrfs_buffer_uptodate(tmp, gen)) { | |
1480 | *eb_ret = tmp; | |
1481 | return 0; | |
1482 | } | |
1483 | free_extent_buffer(tmp); | |
b3b4aa74 | 1484 | btrfs_release_path(p); |
cb44921a CM |
1485 | return -EIO; |
1486 | } | |
c8c42864 CM |
1487 | } |
1488 | ||
1489 | /* | |
1490 | * reduce lock contention at high levels | |
1491 | * of the btree by dropping locks before | |
76a05b35 CM |
1492 | * we read. Don't release the lock on the current |
1493 | * level because we need to walk this node to figure | |
1494 | * out which blocks to read. | |
c8c42864 | 1495 | */ |
8c594ea8 CM |
1496 | btrfs_unlock_up_safe(p, level + 1); |
1497 | btrfs_set_path_blocking(p); | |
1498 | ||
cb44921a | 1499 | free_extent_buffer(tmp); |
c8c42864 CM |
1500 | if (p->reada) |
1501 | reada_for_search(root, p, level, slot, key->objectid); | |
1502 | ||
b3b4aa74 | 1503 | btrfs_release_path(p); |
76a05b35 CM |
1504 | |
1505 | ret = -EAGAIN; | |
5bdd3536 | 1506 | tmp = read_tree_block(root, blocknr, blocksize, 0); |
76a05b35 CM |
1507 | if (tmp) { |
1508 | /* | |
1509 | * If the read above didn't mark this buffer up to date, | |
1510 | * it will never end up being up to date. Set ret to EIO now | |
1511 | * and give up so that our caller doesn't loop forever | |
1512 | * on our EAGAINs. | |
1513 | */ | |
1514 | if (!btrfs_buffer_uptodate(tmp, 0)) | |
1515 | ret = -EIO; | |
c8c42864 | 1516 | free_extent_buffer(tmp); |
76a05b35 CM |
1517 | } |
1518 | return ret; | |
c8c42864 CM |
1519 | } |
1520 | ||
1521 | /* | |
1522 | * helper function for btrfs_search_slot. This does all of the checks | |
1523 | * for node-level blocks and does any balancing required based on | |
1524 | * the ins_len. | |
1525 | * | |
1526 | * If no extra work was required, zero is returned. If we had to | |
1527 | * drop the path, -EAGAIN is returned and btrfs_search_slot must | |
1528 | * start over | |
1529 | */ | |
1530 | static int | |
1531 | setup_nodes_for_search(struct btrfs_trans_handle *trans, | |
1532 | struct btrfs_root *root, struct btrfs_path *p, | |
bd681513 CM |
1533 | struct extent_buffer *b, int level, int ins_len, |
1534 | int *write_lock_level) | |
c8c42864 CM |
1535 | { |
1536 | int ret; | |
1537 | if ((p->search_for_split || ins_len > 0) && btrfs_header_nritems(b) >= | |
1538 | BTRFS_NODEPTRS_PER_BLOCK(root) - 3) { | |
1539 | int sret; | |
1540 | ||
bd681513 CM |
1541 | if (*write_lock_level < level + 1) { |
1542 | *write_lock_level = level + 1; | |
1543 | btrfs_release_path(p); | |
1544 | goto again; | |
1545 | } | |
1546 | ||
c8c42864 CM |
1547 | sret = reada_for_balance(root, p, level); |
1548 | if (sret) | |
1549 | goto again; | |
1550 | ||
1551 | btrfs_set_path_blocking(p); | |
1552 | sret = split_node(trans, root, p, level); | |
bd681513 | 1553 | btrfs_clear_path_blocking(p, NULL, 0); |
c8c42864 CM |
1554 | |
1555 | BUG_ON(sret > 0); | |
1556 | if (sret) { | |
1557 | ret = sret; | |
1558 | goto done; | |
1559 | } | |
1560 | b = p->nodes[level]; | |
1561 | } else if (ins_len < 0 && btrfs_header_nritems(b) < | |
cfbb9308 | 1562 | BTRFS_NODEPTRS_PER_BLOCK(root) / 2) { |
c8c42864 CM |
1563 | int sret; |
1564 | ||
bd681513 CM |
1565 | if (*write_lock_level < level + 1) { |
1566 | *write_lock_level = level + 1; | |
1567 | btrfs_release_path(p); | |
1568 | goto again; | |
1569 | } | |
1570 | ||
c8c42864 CM |
1571 | sret = reada_for_balance(root, p, level); |
1572 | if (sret) | |
1573 | goto again; | |
1574 | ||
1575 | btrfs_set_path_blocking(p); | |
1576 | sret = balance_level(trans, root, p, level); | |
bd681513 | 1577 | btrfs_clear_path_blocking(p, NULL, 0); |
c8c42864 CM |
1578 | |
1579 | if (sret) { | |
1580 | ret = sret; | |
1581 | goto done; | |
1582 | } | |
1583 | b = p->nodes[level]; | |
1584 | if (!b) { | |
b3b4aa74 | 1585 | btrfs_release_path(p); |
c8c42864 CM |
1586 | goto again; |
1587 | } | |
1588 | BUG_ON(btrfs_header_nritems(b) == 1); | |
1589 | } | |
1590 | return 0; | |
1591 | ||
1592 | again: | |
1593 | ret = -EAGAIN; | |
1594 | done: | |
1595 | return ret; | |
1596 | } | |
1597 | ||
74123bd7 CM |
1598 | /* |
1599 | * look for key in the tree. path is filled in with nodes along the way | |
1600 | * if key is found, we return zero and you can find the item in the leaf | |
1601 | * level of the path (level 0) | |
1602 | * | |
1603 | * If the key isn't found, the path points to the slot where it should | |
aa5d6bed CM |
1604 | * be inserted, and 1 is returned. If there are other errors during the |
1605 | * search a negative error number is returned. | |
97571fd0 CM |
1606 | * |
1607 | * if ins_len > 0, nodes and leaves will be split as we walk down the | |
1608 | * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if | |
1609 | * possible) | |
74123bd7 | 1610 | */ |
e089f05c CM |
1611 | int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root |
1612 | *root, struct btrfs_key *key, struct btrfs_path *p, int | |
1613 | ins_len, int cow) | |
be0e5c09 | 1614 | { |
5f39d397 | 1615 | struct extent_buffer *b; |
be0e5c09 CM |
1616 | int slot; |
1617 | int ret; | |
33c66f43 | 1618 | int err; |
be0e5c09 | 1619 | int level; |
925baedd | 1620 | int lowest_unlock = 1; |
bd681513 CM |
1621 | int root_lock; |
1622 | /* everything at write_lock_level or lower must be write locked */ | |
1623 | int write_lock_level = 0; | |
9f3a7427 CM |
1624 | u8 lowest_level = 0; |
1625 | ||
6702ed49 | 1626 | lowest_level = p->lowest_level; |
323ac95b | 1627 | WARN_ON(lowest_level && ins_len > 0); |
22b0ebda | 1628 | WARN_ON(p->nodes[0] != NULL); |
25179201 | 1629 | |
bd681513 | 1630 | if (ins_len < 0) { |
925baedd | 1631 | lowest_unlock = 2; |
65b51a00 | 1632 | |
bd681513 CM |
1633 | /* when we are removing items, we might have to go up to level |
1634 | * two as we update tree pointers Make sure we keep write | |
1635 | * for those levels as well | |
1636 | */ | |
1637 | write_lock_level = 2; | |
1638 | } else if (ins_len > 0) { | |
1639 | /* | |
1640 | * for inserting items, make sure we have a write lock on | |
1641 | * level 1 so we can update keys | |
1642 | */ | |
1643 | write_lock_level = 1; | |
1644 | } | |
1645 | ||
1646 | if (!cow) | |
1647 | write_lock_level = -1; | |
1648 | ||
1649 | if (cow && (p->keep_locks || p->lowest_level)) | |
1650 | write_lock_level = BTRFS_MAX_LEVEL; | |
1651 | ||
bb803951 | 1652 | again: |
bd681513 CM |
1653 | /* |
1654 | * we try very hard to do read locks on the root | |
1655 | */ | |
1656 | root_lock = BTRFS_READ_LOCK; | |
1657 | level = 0; | |
5d4f98a2 | 1658 | if (p->search_commit_root) { |
bd681513 CM |
1659 | /* |
1660 | * the commit roots are read only | |
1661 | * so we always do read locks | |
1662 | */ | |
5d4f98a2 YZ |
1663 | b = root->commit_root; |
1664 | extent_buffer_get(b); | |
bd681513 | 1665 | level = btrfs_header_level(b); |
5d4f98a2 | 1666 | if (!p->skip_locking) |
bd681513 | 1667 | btrfs_tree_read_lock(b); |
5d4f98a2 | 1668 | } else { |
bd681513 | 1669 | if (p->skip_locking) { |
5d4f98a2 | 1670 | b = btrfs_root_node(root); |
bd681513 CM |
1671 | level = btrfs_header_level(b); |
1672 | } else { | |
1673 | /* we don't know the level of the root node | |
1674 | * until we actually have it read locked | |
1675 | */ | |
1676 | b = btrfs_read_lock_root_node(root); | |
1677 | level = btrfs_header_level(b); | |
1678 | if (level <= write_lock_level) { | |
1679 | /* whoops, must trade for write lock */ | |
1680 | btrfs_tree_read_unlock(b); | |
1681 | free_extent_buffer(b); | |
1682 | b = btrfs_lock_root_node(root); | |
1683 | root_lock = BTRFS_WRITE_LOCK; | |
1684 | ||
1685 | /* the level might have changed, check again */ | |
1686 | level = btrfs_header_level(b); | |
1687 | } | |
1688 | } | |
5d4f98a2 | 1689 | } |
bd681513 CM |
1690 | p->nodes[level] = b; |
1691 | if (!p->skip_locking) | |
1692 | p->locks[level] = root_lock; | |
925baedd | 1693 | |
eb60ceac | 1694 | while (b) { |
5f39d397 | 1695 | level = btrfs_header_level(b); |
65b51a00 CM |
1696 | |
1697 | /* | |
1698 | * setup the path here so we can release it under lock | |
1699 | * contention with the cow code | |
1700 | */ | |
02217ed2 | 1701 | if (cow) { |
c8c42864 CM |
1702 | /* |
1703 | * if we don't really need to cow this block | |
1704 | * then we don't want to set the path blocking, | |
1705 | * so we test it here | |
1706 | */ | |
5d4f98a2 | 1707 | if (!should_cow_block(trans, root, b)) |
65b51a00 | 1708 | goto cow_done; |
5d4f98a2 | 1709 | |
b4ce94de CM |
1710 | btrfs_set_path_blocking(p); |
1711 | ||
bd681513 CM |
1712 | /* |
1713 | * must have write locks on this node and the | |
1714 | * parent | |
1715 | */ | |
1716 | if (level + 1 > write_lock_level) { | |
1717 | write_lock_level = level + 1; | |
1718 | btrfs_release_path(p); | |
1719 | goto again; | |
1720 | } | |
1721 | ||
33c66f43 YZ |
1722 | err = btrfs_cow_block(trans, root, b, |
1723 | p->nodes[level + 1], | |
1724 | p->slots[level + 1], &b); | |
1725 | if (err) { | |
33c66f43 | 1726 | ret = err; |
65b51a00 | 1727 | goto done; |
54aa1f4d | 1728 | } |
02217ed2 | 1729 | } |
65b51a00 | 1730 | cow_done: |
02217ed2 | 1731 | BUG_ON(!cow && ins_len); |
65b51a00 | 1732 | |
eb60ceac | 1733 | p->nodes[level] = b; |
bd681513 | 1734 | btrfs_clear_path_blocking(p, NULL, 0); |
b4ce94de CM |
1735 | |
1736 | /* | |
1737 | * we have a lock on b and as long as we aren't changing | |
1738 | * the tree, there is no way to for the items in b to change. | |
1739 | * It is safe to drop the lock on our parent before we | |
1740 | * go through the expensive btree search on b. | |
1741 | * | |
1742 | * If cow is true, then we might be changing slot zero, | |
1743 | * which may require changing the parent. So, we can't | |
1744 | * drop the lock until after we know which slot we're | |
1745 | * operating on. | |
1746 | */ | |
1747 | if (!cow) | |
1748 | btrfs_unlock_up_safe(p, level + 1); | |
1749 | ||
5f39d397 | 1750 | ret = bin_search(b, key, level, &slot); |
b4ce94de | 1751 | |
5f39d397 | 1752 | if (level != 0) { |
33c66f43 YZ |
1753 | int dec = 0; |
1754 | if (ret && slot > 0) { | |
1755 | dec = 1; | |
be0e5c09 | 1756 | slot -= 1; |
33c66f43 | 1757 | } |
be0e5c09 | 1758 | p->slots[level] = slot; |
33c66f43 | 1759 | err = setup_nodes_for_search(trans, root, p, b, level, |
bd681513 | 1760 | ins_len, &write_lock_level); |
33c66f43 | 1761 | if (err == -EAGAIN) |
c8c42864 | 1762 | goto again; |
33c66f43 YZ |
1763 | if (err) { |
1764 | ret = err; | |
c8c42864 | 1765 | goto done; |
33c66f43 | 1766 | } |
c8c42864 CM |
1767 | b = p->nodes[level]; |
1768 | slot = p->slots[level]; | |
b4ce94de | 1769 | |
bd681513 CM |
1770 | /* |
1771 | * slot 0 is special, if we change the key | |
1772 | * we have to update the parent pointer | |
1773 | * which means we must have a write lock | |
1774 | * on the parent | |
1775 | */ | |
1776 | if (slot == 0 && cow && | |
1777 | write_lock_level < level + 1) { | |
1778 | write_lock_level = level + 1; | |
1779 | btrfs_release_path(p); | |
1780 | goto again; | |
1781 | } | |
1782 | ||
f9efa9c7 CM |
1783 | unlock_up(p, level, lowest_unlock); |
1784 | ||
925baedd | 1785 | if (level == lowest_level) { |
33c66f43 YZ |
1786 | if (dec) |
1787 | p->slots[level]++; | |
5b21f2ed | 1788 | goto done; |
925baedd | 1789 | } |
ca7a79ad | 1790 | |
33c66f43 | 1791 | err = read_block_for_search(trans, root, p, |
c8c42864 | 1792 | &b, level, slot, key); |
33c66f43 | 1793 | if (err == -EAGAIN) |
c8c42864 | 1794 | goto again; |
33c66f43 YZ |
1795 | if (err) { |
1796 | ret = err; | |
76a05b35 | 1797 | goto done; |
33c66f43 | 1798 | } |
76a05b35 | 1799 | |
b4ce94de | 1800 | if (!p->skip_locking) { |
bd681513 CM |
1801 | level = btrfs_header_level(b); |
1802 | if (level <= write_lock_level) { | |
1803 | err = btrfs_try_tree_write_lock(b); | |
1804 | if (!err) { | |
1805 | btrfs_set_path_blocking(p); | |
1806 | btrfs_tree_lock(b); | |
1807 | btrfs_clear_path_blocking(p, b, | |
1808 | BTRFS_WRITE_LOCK); | |
1809 | } | |
1810 | p->locks[level] = BTRFS_WRITE_LOCK; | |
1811 | } else { | |
1812 | err = btrfs_try_tree_read_lock(b); | |
1813 | if (!err) { | |
1814 | btrfs_set_path_blocking(p); | |
1815 | btrfs_tree_read_lock(b); | |
1816 | btrfs_clear_path_blocking(p, b, | |
1817 | BTRFS_READ_LOCK); | |
1818 | } | |
1819 | p->locks[level] = BTRFS_READ_LOCK; | |
b4ce94de | 1820 | } |
bd681513 | 1821 | p->nodes[level] = b; |
b4ce94de | 1822 | } |
be0e5c09 CM |
1823 | } else { |
1824 | p->slots[level] = slot; | |
87b29b20 YZ |
1825 | if (ins_len > 0 && |
1826 | btrfs_leaf_free_space(root, b) < ins_len) { | |
bd681513 CM |
1827 | if (write_lock_level < 1) { |
1828 | write_lock_level = 1; | |
1829 | btrfs_release_path(p); | |
1830 | goto again; | |
1831 | } | |
1832 | ||
b4ce94de | 1833 | btrfs_set_path_blocking(p); |
33c66f43 YZ |
1834 | err = split_leaf(trans, root, key, |
1835 | p, ins_len, ret == 0); | |
bd681513 | 1836 | btrfs_clear_path_blocking(p, NULL, 0); |
b4ce94de | 1837 | |
33c66f43 YZ |
1838 | BUG_ON(err > 0); |
1839 | if (err) { | |
1840 | ret = err; | |
65b51a00 CM |
1841 | goto done; |
1842 | } | |
5c680ed6 | 1843 | } |
459931ec CM |
1844 | if (!p->search_for_split) |
1845 | unlock_up(p, level, lowest_unlock); | |
65b51a00 | 1846 | goto done; |
be0e5c09 CM |
1847 | } |
1848 | } | |
65b51a00 CM |
1849 | ret = 1; |
1850 | done: | |
b4ce94de CM |
1851 | /* |
1852 | * we don't really know what they plan on doing with the path | |
1853 | * from here on, so for now just mark it as blocking | |
1854 | */ | |
b9473439 CM |
1855 | if (!p->leave_spinning) |
1856 | btrfs_set_path_blocking(p); | |
76a05b35 | 1857 | if (ret < 0) |
b3b4aa74 | 1858 | btrfs_release_path(p); |
65b51a00 | 1859 | return ret; |
be0e5c09 CM |
1860 | } |
1861 | ||
74123bd7 CM |
1862 | /* |
1863 | * adjust the pointers going up the tree, starting at level | |
1864 | * making sure the right key of each node is points to 'key'. | |
1865 | * This is used after shifting pointers to the left, so it stops | |
1866 | * fixing up pointers when a given leaf/node is not in slot 0 of the | |
1867 | * higher levels | |
aa5d6bed CM |
1868 | * |
1869 | * If this fails to write a tree block, it returns -1, but continues | |
1870 | * fixing up the blocks in ram so the tree is consistent. | |
74123bd7 | 1871 | */ |
5f39d397 CM |
1872 | static int fixup_low_keys(struct btrfs_trans_handle *trans, |
1873 | struct btrfs_root *root, struct btrfs_path *path, | |
1874 | struct btrfs_disk_key *key, int level) | |
be0e5c09 CM |
1875 | { |
1876 | int i; | |
aa5d6bed | 1877 | int ret = 0; |
5f39d397 CM |
1878 | struct extent_buffer *t; |
1879 | ||
234b63a0 | 1880 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { |
be0e5c09 | 1881 | int tslot = path->slots[i]; |
eb60ceac | 1882 | if (!path->nodes[i]) |
be0e5c09 | 1883 | break; |
5f39d397 CM |
1884 | t = path->nodes[i]; |
1885 | btrfs_set_node_key(t, key, tslot); | |
d6025579 | 1886 | btrfs_mark_buffer_dirty(path->nodes[i]); |
be0e5c09 CM |
1887 | if (tslot != 0) |
1888 | break; | |
1889 | } | |
aa5d6bed | 1890 | return ret; |
be0e5c09 CM |
1891 | } |
1892 | ||
31840ae1 ZY |
1893 | /* |
1894 | * update item key. | |
1895 | * | |
1896 | * This function isn't completely safe. It's the caller's responsibility | |
1897 | * that the new key won't break the order | |
1898 | */ | |
1899 | int btrfs_set_item_key_safe(struct btrfs_trans_handle *trans, | |
1900 | struct btrfs_root *root, struct btrfs_path *path, | |
1901 | struct btrfs_key *new_key) | |
1902 | { | |
1903 | struct btrfs_disk_key disk_key; | |
1904 | struct extent_buffer *eb; | |
1905 | int slot; | |
1906 | ||
1907 | eb = path->nodes[0]; | |
1908 | slot = path->slots[0]; | |
1909 | if (slot > 0) { | |
1910 | btrfs_item_key(eb, &disk_key, slot - 1); | |
1911 | if (comp_keys(&disk_key, new_key) >= 0) | |
1912 | return -1; | |
1913 | } | |
1914 | if (slot < btrfs_header_nritems(eb) - 1) { | |
1915 | btrfs_item_key(eb, &disk_key, slot + 1); | |
1916 | if (comp_keys(&disk_key, new_key) <= 0) | |
1917 | return -1; | |
1918 | } | |
1919 | ||
1920 | btrfs_cpu_key_to_disk(&disk_key, new_key); | |
1921 | btrfs_set_item_key(eb, &disk_key, slot); | |
1922 | btrfs_mark_buffer_dirty(eb); | |
1923 | if (slot == 0) | |
1924 | fixup_low_keys(trans, root, path, &disk_key, 1); | |
1925 | return 0; | |
1926 | } | |
1927 | ||
74123bd7 CM |
1928 | /* |
1929 | * try to push data from one node into the next node left in the | |
79f95c82 | 1930 | * tree. |
aa5d6bed CM |
1931 | * |
1932 | * returns 0 if some ptrs were pushed left, < 0 if there was some horrible | |
1933 | * error, and > 0 if there was no room in the left hand block. | |
74123bd7 | 1934 | */ |
98ed5174 CM |
1935 | static int push_node_left(struct btrfs_trans_handle *trans, |
1936 | struct btrfs_root *root, struct extent_buffer *dst, | |
971a1f66 | 1937 | struct extent_buffer *src, int empty) |
be0e5c09 | 1938 | { |
be0e5c09 | 1939 | int push_items = 0; |
bb803951 CM |
1940 | int src_nritems; |
1941 | int dst_nritems; | |
aa5d6bed | 1942 | int ret = 0; |
be0e5c09 | 1943 | |
5f39d397 CM |
1944 | src_nritems = btrfs_header_nritems(src); |
1945 | dst_nritems = btrfs_header_nritems(dst); | |
123abc88 | 1946 | push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems; |
7bb86316 CM |
1947 | WARN_ON(btrfs_header_generation(src) != trans->transid); |
1948 | WARN_ON(btrfs_header_generation(dst) != trans->transid); | |
54aa1f4d | 1949 | |
bce4eae9 | 1950 | if (!empty && src_nritems <= 8) |
971a1f66 CM |
1951 | return 1; |
1952 | ||
d397712b | 1953 | if (push_items <= 0) |
be0e5c09 CM |
1954 | return 1; |
1955 | ||
bce4eae9 | 1956 | if (empty) { |
971a1f66 | 1957 | push_items = min(src_nritems, push_items); |
bce4eae9 CM |
1958 | if (push_items < src_nritems) { |
1959 | /* leave at least 8 pointers in the node if | |
1960 | * we aren't going to empty it | |
1961 | */ | |
1962 | if (src_nritems - push_items < 8) { | |
1963 | if (push_items <= 8) | |
1964 | return 1; | |
1965 | push_items -= 8; | |
1966 | } | |
1967 | } | |
1968 | } else | |
1969 | push_items = min(src_nritems - 8, push_items); | |
79f95c82 | 1970 | |
5f39d397 CM |
1971 | copy_extent_buffer(dst, src, |
1972 | btrfs_node_key_ptr_offset(dst_nritems), | |
1973 | btrfs_node_key_ptr_offset(0), | |
d397712b | 1974 | push_items * sizeof(struct btrfs_key_ptr)); |
5f39d397 | 1975 | |
bb803951 | 1976 | if (push_items < src_nritems) { |
5f39d397 CM |
1977 | memmove_extent_buffer(src, btrfs_node_key_ptr_offset(0), |
1978 | btrfs_node_key_ptr_offset(push_items), | |
1979 | (src_nritems - push_items) * | |
1980 | sizeof(struct btrfs_key_ptr)); | |
1981 | } | |
1982 | btrfs_set_header_nritems(src, src_nritems - push_items); | |
1983 | btrfs_set_header_nritems(dst, dst_nritems + push_items); | |
1984 | btrfs_mark_buffer_dirty(src); | |
1985 | btrfs_mark_buffer_dirty(dst); | |
31840ae1 | 1986 | |
79f95c82 CM |
1987 | return ret; |
1988 | } | |
1989 | ||
1990 | /* | |
1991 | * try to push data from one node into the next node right in the | |
1992 | * tree. | |
1993 | * | |
1994 | * returns 0 if some ptrs were pushed, < 0 if there was some horrible | |
1995 | * error, and > 0 if there was no room in the right hand block. | |
1996 | * | |
1997 | * this will only push up to 1/2 the contents of the left node over | |
1998 | */ | |
5f39d397 CM |
1999 | static int balance_node_right(struct btrfs_trans_handle *trans, |
2000 | struct btrfs_root *root, | |
2001 | struct extent_buffer *dst, | |
2002 | struct extent_buffer *src) | |
79f95c82 | 2003 | { |
79f95c82 CM |
2004 | int push_items = 0; |
2005 | int max_push; | |
2006 | int src_nritems; | |
2007 | int dst_nritems; | |
2008 | int ret = 0; | |
79f95c82 | 2009 | |
7bb86316 CM |
2010 | WARN_ON(btrfs_header_generation(src) != trans->transid); |
2011 | WARN_ON(btrfs_header_generation(dst) != trans->transid); | |
2012 | ||
5f39d397 CM |
2013 | src_nritems = btrfs_header_nritems(src); |
2014 | dst_nritems = btrfs_header_nritems(dst); | |
123abc88 | 2015 | push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems; |
d397712b | 2016 | if (push_items <= 0) |
79f95c82 | 2017 | return 1; |
bce4eae9 | 2018 | |
d397712b | 2019 | if (src_nritems < 4) |
bce4eae9 | 2020 | return 1; |
79f95c82 CM |
2021 | |
2022 | max_push = src_nritems / 2 + 1; | |
2023 | /* don't try to empty the node */ | |
d397712b | 2024 | if (max_push >= src_nritems) |
79f95c82 | 2025 | return 1; |
252c38f0 | 2026 | |
79f95c82 CM |
2027 | if (max_push < push_items) |
2028 | push_items = max_push; | |
2029 | ||
5f39d397 CM |
2030 | memmove_extent_buffer(dst, btrfs_node_key_ptr_offset(push_items), |
2031 | btrfs_node_key_ptr_offset(0), | |
2032 | (dst_nritems) * | |
2033 | sizeof(struct btrfs_key_ptr)); | |
d6025579 | 2034 | |
5f39d397 CM |
2035 | copy_extent_buffer(dst, src, |
2036 | btrfs_node_key_ptr_offset(0), | |
2037 | btrfs_node_key_ptr_offset(src_nritems - push_items), | |
d397712b | 2038 | push_items * sizeof(struct btrfs_key_ptr)); |
79f95c82 | 2039 | |
5f39d397 CM |
2040 | btrfs_set_header_nritems(src, src_nritems - push_items); |
2041 | btrfs_set_header_nritems(dst, dst_nritems + push_items); | |
79f95c82 | 2042 | |
5f39d397 CM |
2043 | btrfs_mark_buffer_dirty(src); |
2044 | btrfs_mark_buffer_dirty(dst); | |
31840ae1 | 2045 | |
aa5d6bed | 2046 | return ret; |
be0e5c09 CM |
2047 | } |
2048 | ||
97571fd0 CM |
2049 | /* |
2050 | * helper function to insert a new root level in the tree. | |
2051 | * A new node is allocated, and a single item is inserted to | |
2052 | * point to the existing root | |
aa5d6bed CM |
2053 | * |
2054 | * returns zero on success or < 0 on failure. | |
97571fd0 | 2055 | */ |
d397712b | 2056 | static noinline int insert_new_root(struct btrfs_trans_handle *trans, |
5f39d397 CM |
2057 | struct btrfs_root *root, |
2058 | struct btrfs_path *path, int level) | |
5c680ed6 | 2059 | { |
7bb86316 | 2060 | u64 lower_gen; |
5f39d397 CM |
2061 | struct extent_buffer *lower; |
2062 | struct extent_buffer *c; | |
925baedd | 2063 | struct extent_buffer *old; |
5f39d397 | 2064 | struct btrfs_disk_key lower_key; |
5c680ed6 CM |
2065 | |
2066 | BUG_ON(path->nodes[level]); | |
2067 | BUG_ON(path->nodes[level-1] != root->node); | |
2068 | ||
7bb86316 CM |
2069 | lower = path->nodes[level-1]; |
2070 | if (level == 1) | |
2071 | btrfs_item_key(lower, &lower_key, 0); | |
2072 | else | |
2073 | btrfs_node_key(lower, &lower_key, 0); | |
2074 | ||
31840ae1 | 2075 | c = btrfs_alloc_free_block(trans, root, root->nodesize, 0, |
5d4f98a2 | 2076 | root->root_key.objectid, &lower_key, |
ad3d81ba | 2077 | level, root->node->start, 0); |
5f39d397 CM |
2078 | if (IS_ERR(c)) |
2079 | return PTR_ERR(c); | |
925baedd | 2080 | |
f0486c68 YZ |
2081 | root_add_used(root, root->nodesize); |
2082 | ||
5d4f98a2 | 2083 | memset_extent_buffer(c, 0, 0, sizeof(struct btrfs_header)); |
5f39d397 CM |
2084 | btrfs_set_header_nritems(c, 1); |
2085 | btrfs_set_header_level(c, level); | |
db94535d | 2086 | btrfs_set_header_bytenr(c, c->start); |
5f39d397 | 2087 | btrfs_set_header_generation(c, trans->transid); |
5d4f98a2 | 2088 | btrfs_set_header_backref_rev(c, BTRFS_MIXED_BACKREF_REV); |
5f39d397 | 2089 | btrfs_set_header_owner(c, root->root_key.objectid); |
5f39d397 CM |
2090 | |
2091 | write_extent_buffer(c, root->fs_info->fsid, | |
2092 | (unsigned long)btrfs_header_fsid(c), | |
2093 | BTRFS_FSID_SIZE); | |
e17cade2 CM |
2094 | |
2095 | write_extent_buffer(c, root->fs_info->chunk_tree_uuid, | |
2096 | (unsigned long)btrfs_header_chunk_tree_uuid(c), | |
2097 | BTRFS_UUID_SIZE); | |
2098 | ||
5f39d397 | 2099 | btrfs_set_node_key(c, &lower_key, 0); |
db94535d | 2100 | btrfs_set_node_blockptr(c, 0, lower->start); |
7bb86316 | 2101 | lower_gen = btrfs_header_generation(lower); |
31840ae1 | 2102 | WARN_ON(lower_gen != trans->transid); |
7bb86316 CM |
2103 | |
2104 | btrfs_set_node_ptr_generation(c, 0, lower_gen); | |
d5719762 | 2105 | |
5f39d397 | 2106 | btrfs_mark_buffer_dirty(c); |
d5719762 | 2107 | |
925baedd | 2108 | old = root->node; |
240f62c8 | 2109 | rcu_assign_pointer(root->node, c); |
925baedd CM |
2110 | |
2111 | /* the super has an extra ref to root->node */ | |
2112 | free_extent_buffer(old); | |
2113 | ||
0b86a832 | 2114 | add_root_to_dirty_list(root); |
5f39d397 CM |
2115 | extent_buffer_get(c); |
2116 | path->nodes[level] = c; | |
bd681513 | 2117 | path->locks[level] = BTRFS_WRITE_LOCK; |
5c680ed6 CM |
2118 | path->slots[level] = 0; |
2119 | return 0; | |
2120 | } | |
2121 | ||
74123bd7 CM |
2122 | /* |
2123 | * worker function to insert a single pointer in a node. | |
2124 | * the node should have enough room for the pointer already | |
97571fd0 | 2125 | * |
74123bd7 CM |
2126 | * slot and level indicate where you want the key to go, and |
2127 | * blocknr is the block the key points to. | |
aa5d6bed CM |
2128 | * |
2129 | * returns zero on success and < 0 on any error | |
74123bd7 | 2130 | */ |
e089f05c CM |
2131 | static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root |
2132 | *root, struct btrfs_path *path, struct btrfs_disk_key | |
db94535d | 2133 | *key, u64 bytenr, int slot, int level) |
74123bd7 | 2134 | { |
5f39d397 | 2135 | struct extent_buffer *lower; |
74123bd7 | 2136 | int nritems; |
5c680ed6 CM |
2137 | |
2138 | BUG_ON(!path->nodes[level]); | |
f0486c68 | 2139 | btrfs_assert_tree_locked(path->nodes[level]); |
5f39d397 CM |
2140 | lower = path->nodes[level]; |
2141 | nritems = btrfs_header_nritems(lower); | |
c293498b | 2142 | BUG_ON(slot > nritems); |
123abc88 | 2143 | if (nritems == BTRFS_NODEPTRS_PER_BLOCK(root)) |
74123bd7 CM |
2144 | BUG(); |
2145 | if (slot != nritems) { | |
5f39d397 CM |
2146 | memmove_extent_buffer(lower, |
2147 | btrfs_node_key_ptr_offset(slot + 1), | |
2148 | btrfs_node_key_ptr_offset(slot), | |
d6025579 | 2149 | (nritems - slot) * sizeof(struct btrfs_key_ptr)); |
74123bd7 | 2150 | } |
5f39d397 | 2151 | btrfs_set_node_key(lower, key, slot); |
db94535d | 2152 | btrfs_set_node_blockptr(lower, slot, bytenr); |
74493f7a CM |
2153 | WARN_ON(trans->transid == 0); |
2154 | btrfs_set_node_ptr_generation(lower, slot, trans->transid); | |
5f39d397 CM |
2155 | btrfs_set_header_nritems(lower, nritems + 1); |
2156 | btrfs_mark_buffer_dirty(lower); | |
74123bd7 CM |
2157 | return 0; |
2158 | } | |
2159 | ||
97571fd0 CM |
2160 | /* |
2161 | * split the node at the specified level in path in two. | |
2162 | * The path is corrected to point to the appropriate node after the split | |
2163 | * | |
2164 | * Before splitting this tries to make some room in the node by pushing | |
2165 | * left and right, if either one works, it returns right away. | |
aa5d6bed CM |
2166 | * |
2167 | * returns 0 on success and < 0 on failure | |
97571fd0 | 2168 | */ |
e02119d5 CM |
2169 | static noinline int split_node(struct btrfs_trans_handle *trans, |
2170 | struct btrfs_root *root, | |
2171 | struct btrfs_path *path, int level) | |
be0e5c09 | 2172 | { |
5f39d397 CM |
2173 | struct extent_buffer *c; |
2174 | struct extent_buffer *split; | |
2175 | struct btrfs_disk_key disk_key; | |
be0e5c09 | 2176 | int mid; |
5c680ed6 | 2177 | int ret; |
aa5d6bed | 2178 | int wret; |
7518a238 | 2179 | u32 c_nritems; |
eb60ceac | 2180 | |
5f39d397 | 2181 | c = path->nodes[level]; |
7bb86316 | 2182 | WARN_ON(btrfs_header_generation(c) != trans->transid); |
5f39d397 | 2183 | if (c == root->node) { |
5c680ed6 | 2184 | /* trying to split the root, lets make a new one */ |
e089f05c | 2185 | ret = insert_new_root(trans, root, path, level + 1); |
5c680ed6 CM |
2186 | if (ret) |
2187 | return ret; | |
b3612421 | 2188 | } else { |
e66f709b | 2189 | ret = push_nodes_for_insert(trans, root, path, level); |
5f39d397 CM |
2190 | c = path->nodes[level]; |
2191 | if (!ret && btrfs_header_nritems(c) < | |
c448acf0 | 2192 | BTRFS_NODEPTRS_PER_BLOCK(root) - 3) |
e66f709b | 2193 | return 0; |
54aa1f4d CM |
2194 | if (ret < 0) |
2195 | return ret; | |
be0e5c09 | 2196 | } |
e66f709b | 2197 | |
5f39d397 | 2198 | c_nritems = btrfs_header_nritems(c); |
5d4f98a2 YZ |
2199 | mid = (c_nritems + 1) / 2; |
2200 | btrfs_node_key(c, &disk_key, mid); | |
7bb86316 | 2201 | |
5d4f98a2 | 2202 | split = btrfs_alloc_free_block(trans, root, root->nodesize, 0, |
31840ae1 | 2203 | root->root_key.objectid, |
5d4f98a2 | 2204 | &disk_key, level, c->start, 0); |
5f39d397 CM |
2205 | if (IS_ERR(split)) |
2206 | return PTR_ERR(split); | |
2207 | ||
f0486c68 YZ |
2208 | root_add_used(root, root->nodesize); |
2209 | ||
5d4f98a2 | 2210 | memset_extent_buffer(split, 0, 0, sizeof(struct btrfs_header)); |
5f39d397 | 2211 | btrfs_set_header_level(split, btrfs_header_level(c)); |
db94535d | 2212 | btrfs_set_header_bytenr(split, split->start); |
5f39d397 | 2213 | btrfs_set_header_generation(split, trans->transid); |
5d4f98a2 | 2214 | btrfs_set_header_backref_rev(split, BTRFS_MIXED_BACKREF_REV); |
5f39d397 CM |
2215 | btrfs_set_header_owner(split, root->root_key.objectid); |
2216 | write_extent_buffer(split, root->fs_info->fsid, | |
2217 | (unsigned long)btrfs_header_fsid(split), | |
2218 | BTRFS_FSID_SIZE); | |
e17cade2 CM |
2219 | write_extent_buffer(split, root->fs_info->chunk_tree_uuid, |
2220 | (unsigned long)btrfs_header_chunk_tree_uuid(split), | |
2221 | BTRFS_UUID_SIZE); | |
54aa1f4d | 2222 | |
5f39d397 CM |
2223 | |
2224 | copy_extent_buffer(split, c, | |
2225 | btrfs_node_key_ptr_offset(0), | |
2226 | btrfs_node_key_ptr_offset(mid), | |
2227 | (c_nritems - mid) * sizeof(struct btrfs_key_ptr)); | |
2228 | btrfs_set_header_nritems(split, c_nritems - mid); | |
2229 | btrfs_set_header_nritems(c, mid); | |
aa5d6bed CM |
2230 | ret = 0; |
2231 | ||
5f39d397 CM |
2232 | btrfs_mark_buffer_dirty(c); |
2233 | btrfs_mark_buffer_dirty(split); | |
2234 | ||
db94535d | 2235 | wret = insert_ptr(trans, root, path, &disk_key, split->start, |
5f39d397 | 2236 | path->slots[level + 1] + 1, |
123abc88 | 2237 | level + 1); |
aa5d6bed CM |
2238 | if (wret) |
2239 | ret = wret; | |
2240 | ||
5de08d7d | 2241 | if (path->slots[level] >= mid) { |
5c680ed6 | 2242 | path->slots[level] -= mid; |
925baedd | 2243 | btrfs_tree_unlock(c); |
5f39d397 CM |
2244 | free_extent_buffer(c); |
2245 | path->nodes[level] = split; | |
5c680ed6 CM |
2246 | path->slots[level + 1] += 1; |
2247 | } else { | |
925baedd | 2248 | btrfs_tree_unlock(split); |
5f39d397 | 2249 | free_extent_buffer(split); |
be0e5c09 | 2250 | } |
aa5d6bed | 2251 | return ret; |
be0e5c09 CM |
2252 | } |
2253 | ||
74123bd7 CM |
2254 | /* |
2255 | * how many bytes are required to store the items in a leaf. start | |
2256 | * and nr indicate which items in the leaf to check. This totals up the | |
2257 | * space used both by the item structs and the item data | |
2258 | */ | |
5f39d397 | 2259 | static int leaf_space_used(struct extent_buffer *l, int start, int nr) |
be0e5c09 CM |
2260 | { |
2261 | int data_len; | |
5f39d397 | 2262 | int nritems = btrfs_header_nritems(l); |
d4dbff95 | 2263 | int end = min(nritems, start + nr) - 1; |
be0e5c09 CM |
2264 | |
2265 | if (!nr) | |
2266 | return 0; | |
5f39d397 CM |
2267 | data_len = btrfs_item_end_nr(l, start); |
2268 | data_len = data_len - btrfs_item_offset_nr(l, end); | |
0783fcfc | 2269 | data_len += sizeof(struct btrfs_item) * nr; |
d4dbff95 | 2270 | WARN_ON(data_len < 0); |
be0e5c09 CM |
2271 | return data_len; |
2272 | } | |
2273 | ||
d4dbff95 CM |
2274 | /* |
2275 | * The space between the end of the leaf items and | |
2276 | * the start of the leaf data. IOW, how much room | |
2277 | * the leaf has left for both items and data | |
2278 | */ | |
d397712b | 2279 | noinline int btrfs_leaf_free_space(struct btrfs_root *root, |
e02119d5 | 2280 | struct extent_buffer *leaf) |
d4dbff95 | 2281 | { |
5f39d397 CM |
2282 | int nritems = btrfs_header_nritems(leaf); |
2283 | int ret; | |
2284 | ret = BTRFS_LEAF_DATA_SIZE(root) - leaf_space_used(leaf, 0, nritems); | |
2285 | if (ret < 0) { | |
d397712b CM |
2286 | printk(KERN_CRIT "leaf free space ret %d, leaf data size %lu, " |
2287 | "used %d nritems %d\n", | |
ae2f5411 | 2288 | ret, (unsigned long) BTRFS_LEAF_DATA_SIZE(root), |
5f39d397 CM |
2289 | leaf_space_used(leaf, 0, nritems), nritems); |
2290 | } | |
2291 | return ret; | |
d4dbff95 CM |
2292 | } |
2293 | ||
99d8f83c CM |
2294 | /* |
2295 | * min slot controls the lowest index we're willing to push to the | |
2296 | * right. We'll push up to and including min_slot, but no lower | |
2297 | */ | |
44871b1b CM |
2298 | static noinline int __push_leaf_right(struct btrfs_trans_handle *trans, |
2299 | struct btrfs_root *root, | |
2300 | struct btrfs_path *path, | |
2301 | int data_size, int empty, | |
2302 | struct extent_buffer *right, | |
99d8f83c CM |
2303 | int free_space, u32 left_nritems, |
2304 | u32 min_slot) | |
00ec4c51 | 2305 | { |
5f39d397 | 2306 | struct extent_buffer *left = path->nodes[0]; |
44871b1b | 2307 | struct extent_buffer *upper = path->nodes[1]; |
5f39d397 | 2308 | struct btrfs_disk_key disk_key; |
00ec4c51 | 2309 | int slot; |
34a38218 | 2310 | u32 i; |
00ec4c51 CM |
2311 | int push_space = 0; |
2312 | int push_items = 0; | |
0783fcfc | 2313 | struct btrfs_item *item; |
34a38218 | 2314 | u32 nr; |
7518a238 | 2315 | u32 right_nritems; |
5f39d397 | 2316 | u32 data_end; |
db94535d | 2317 | u32 this_item_size; |
00ec4c51 | 2318 | |
34a38218 CM |
2319 | if (empty) |
2320 | nr = 0; | |
2321 | else | |
99d8f83c | 2322 | nr = max_t(u32, 1, min_slot); |
34a38218 | 2323 | |
31840ae1 | 2324 | if (path->slots[0] >= left_nritems) |
87b29b20 | 2325 | push_space += data_size; |
31840ae1 | 2326 | |
44871b1b | 2327 | slot = path->slots[1]; |
34a38218 CM |
2328 | i = left_nritems - 1; |
2329 | while (i >= nr) { | |
5f39d397 | 2330 | item = btrfs_item_nr(left, i); |
db94535d | 2331 | |
31840ae1 ZY |
2332 | if (!empty && push_items > 0) { |
2333 | if (path->slots[0] > i) | |
2334 | break; | |
2335 | if (path->slots[0] == i) { | |
2336 | int space = btrfs_leaf_free_space(root, left); | |
2337 | if (space + push_space * 2 > free_space) | |
2338 | break; | |
2339 | } | |
2340 | } | |
2341 | ||
00ec4c51 | 2342 | if (path->slots[0] == i) |
87b29b20 | 2343 | push_space += data_size; |
db94535d | 2344 | |
db94535d CM |
2345 | this_item_size = btrfs_item_size(left, item); |
2346 | if (this_item_size + sizeof(*item) + push_space > free_space) | |
00ec4c51 | 2347 | break; |
31840ae1 | 2348 | |
00ec4c51 | 2349 | push_items++; |
db94535d | 2350 | push_space += this_item_size + sizeof(*item); |
34a38218 CM |
2351 | if (i == 0) |
2352 | break; | |
2353 | i--; | |
db94535d | 2354 | } |
5f39d397 | 2355 | |
925baedd CM |
2356 | if (push_items == 0) |
2357 | goto out_unlock; | |
5f39d397 | 2358 | |
34a38218 | 2359 | if (!empty && push_items == left_nritems) |
a429e513 | 2360 | WARN_ON(1); |
5f39d397 | 2361 | |
00ec4c51 | 2362 | /* push left to right */ |
5f39d397 | 2363 | right_nritems = btrfs_header_nritems(right); |
34a38218 | 2364 | |
5f39d397 | 2365 | push_space = btrfs_item_end_nr(left, left_nritems - push_items); |
123abc88 | 2366 | push_space -= leaf_data_end(root, left); |
5f39d397 | 2367 | |
00ec4c51 | 2368 | /* make room in the right data area */ |
5f39d397 CM |
2369 | data_end = leaf_data_end(root, right); |
2370 | memmove_extent_buffer(right, | |
2371 | btrfs_leaf_data(right) + data_end - push_space, | |
2372 | btrfs_leaf_data(right) + data_end, | |
2373 | BTRFS_LEAF_DATA_SIZE(root) - data_end); | |
2374 | ||
00ec4c51 | 2375 | /* copy from the left data area */ |
5f39d397 | 2376 | copy_extent_buffer(right, left, btrfs_leaf_data(right) + |
d6025579 CM |
2377 | BTRFS_LEAF_DATA_SIZE(root) - push_space, |
2378 | btrfs_leaf_data(left) + leaf_data_end(root, left), | |
2379 | push_space); | |
5f39d397 CM |
2380 | |
2381 | memmove_extent_buffer(right, btrfs_item_nr_offset(push_items), | |
2382 | btrfs_item_nr_offset(0), | |
2383 | right_nritems * sizeof(struct btrfs_item)); | |
2384 | ||
00ec4c51 | 2385 | /* copy the items from left to right */ |
5f39d397 CM |
2386 | copy_extent_buffer(right, left, btrfs_item_nr_offset(0), |
2387 | btrfs_item_nr_offset(left_nritems - push_items), | |
2388 | push_items * sizeof(struct btrfs_item)); | |
00ec4c51 CM |
2389 | |
2390 | /* update the item pointers */ | |
7518a238 | 2391 | right_nritems += push_items; |
5f39d397 | 2392 | btrfs_set_header_nritems(right, right_nritems); |
123abc88 | 2393 | push_space = BTRFS_LEAF_DATA_SIZE(root); |
7518a238 | 2394 | for (i = 0; i < right_nritems; i++) { |
5f39d397 | 2395 | item = btrfs_item_nr(right, i); |
db94535d CM |
2396 | push_space -= btrfs_item_size(right, item); |
2397 | btrfs_set_item_offset(right, item, push_space); | |
2398 | } | |
2399 | ||
7518a238 | 2400 | left_nritems -= push_items; |
5f39d397 | 2401 | btrfs_set_header_nritems(left, left_nritems); |
00ec4c51 | 2402 | |
34a38218 CM |
2403 | if (left_nritems) |
2404 | btrfs_mark_buffer_dirty(left); | |
f0486c68 YZ |
2405 | else |
2406 | clean_tree_block(trans, root, left); | |
2407 | ||
5f39d397 | 2408 | btrfs_mark_buffer_dirty(right); |
a429e513 | 2409 | |
5f39d397 CM |
2410 | btrfs_item_key(right, &disk_key, 0); |
2411 | btrfs_set_node_key(upper, &disk_key, slot + 1); | |
d6025579 | 2412 | btrfs_mark_buffer_dirty(upper); |
02217ed2 | 2413 | |
00ec4c51 | 2414 | /* then fixup the leaf pointer in the path */ |
7518a238 CM |
2415 | if (path->slots[0] >= left_nritems) { |
2416 | path->slots[0] -= left_nritems; | |
925baedd CM |
2417 | if (btrfs_header_nritems(path->nodes[0]) == 0) |
2418 | clean_tree_block(trans, root, path->nodes[0]); | |
2419 | btrfs_tree_unlock(path->nodes[0]); | |
5f39d397 CM |
2420 | free_extent_buffer(path->nodes[0]); |
2421 | path->nodes[0] = right; | |
00ec4c51 CM |
2422 | path->slots[1] += 1; |
2423 | } else { | |
925baedd | 2424 | btrfs_tree_unlock(right); |
5f39d397 | 2425 | free_extent_buffer(right); |
00ec4c51 CM |
2426 | } |
2427 | return 0; | |
925baedd CM |
2428 | |
2429 | out_unlock: | |
2430 | btrfs_tree_unlock(right); | |
2431 | free_extent_buffer(right); | |
2432 | return 1; | |
00ec4c51 | 2433 | } |
925baedd | 2434 | |
44871b1b CM |
2435 | /* |
2436 | * push some data in the path leaf to the right, trying to free up at | |
2437 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
2438 | * | |
2439 | * returns 1 if the push failed because the other node didn't have enough | |
2440 | * room, 0 if everything worked out and < 0 if there were major errors. | |
99d8f83c CM |
2441 | * |
2442 | * this will push starting from min_slot to the end of the leaf. It won't | |
2443 | * push any slot lower than min_slot | |
44871b1b CM |
2444 | */ |
2445 | static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root | |
99d8f83c CM |
2446 | *root, struct btrfs_path *path, |
2447 | int min_data_size, int data_size, | |
2448 | int empty, u32 min_slot) | |
44871b1b CM |
2449 | { |
2450 | struct extent_buffer *left = path->nodes[0]; | |
2451 | struct extent_buffer *right; | |
2452 | struct extent_buffer *upper; | |
2453 | int slot; | |
2454 | int free_space; | |
2455 | u32 left_nritems; | |
2456 | int ret; | |
2457 | ||
2458 | if (!path->nodes[1]) | |
2459 | return 1; | |
2460 | ||
2461 | slot = path->slots[1]; | |
2462 | upper = path->nodes[1]; | |
2463 | if (slot >= btrfs_header_nritems(upper) - 1) | |
2464 | return 1; | |
2465 | ||
2466 | btrfs_assert_tree_locked(path->nodes[1]); | |
2467 | ||
2468 | right = read_node_slot(root, upper, slot + 1); | |
91ca338d TI |
2469 | if (right == NULL) |
2470 | return 1; | |
2471 | ||
44871b1b CM |
2472 | btrfs_tree_lock(right); |
2473 | btrfs_set_lock_blocking(right); | |
2474 | ||
2475 | free_space = btrfs_leaf_free_space(root, right); | |
2476 | if (free_space < data_size) | |
2477 | goto out_unlock; | |
2478 | ||
2479 | /* cow and double check */ | |
2480 | ret = btrfs_cow_block(trans, root, right, upper, | |
2481 | slot + 1, &right); | |
2482 | if (ret) | |
2483 | goto out_unlock; | |
2484 | ||
2485 | free_space = btrfs_leaf_free_space(root, right); | |
2486 | if (free_space < data_size) | |
2487 | goto out_unlock; | |
2488 | ||
2489 | left_nritems = btrfs_header_nritems(left); | |
2490 | if (left_nritems == 0) | |
2491 | goto out_unlock; | |
2492 | ||
99d8f83c CM |
2493 | return __push_leaf_right(trans, root, path, min_data_size, empty, |
2494 | right, free_space, left_nritems, min_slot); | |
44871b1b CM |
2495 | out_unlock: |
2496 | btrfs_tree_unlock(right); | |
2497 | free_extent_buffer(right); | |
2498 | return 1; | |
2499 | } | |
2500 | ||
74123bd7 CM |
2501 | /* |
2502 | * push some data in the path leaf to the left, trying to free up at | |
2503 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
99d8f83c CM |
2504 | * |
2505 | * max_slot can put a limit on how far into the leaf we'll push items. The | |
2506 | * item at 'max_slot' won't be touched. Use (u32)-1 to make us do all the | |
2507 | * items | |
74123bd7 | 2508 | */ |
44871b1b CM |
2509 | static noinline int __push_leaf_left(struct btrfs_trans_handle *trans, |
2510 | struct btrfs_root *root, | |
2511 | struct btrfs_path *path, int data_size, | |
2512 | int empty, struct extent_buffer *left, | |
99d8f83c CM |
2513 | int free_space, u32 right_nritems, |
2514 | u32 max_slot) | |
be0e5c09 | 2515 | { |
5f39d397 CM |
2516 | struct btrfs_disk_key disk_key; |
2517 | struct extent_buffer *right = path->nodes[0]; | |
be0e5c09 | 2518 | int i; |
be0e5c09 CM |
2519 | int push_space = 0; |
2520 | int push_items = 0; | |
0783fcfc | 2521 | struct btrfs_item *item; |
7518a238 | 2522 | u32 old_left_nritems; |
34a38218 | 2523 | u32 nr; |
aa5d6bed CM |
2524 | int ret = 0; |
2525 | int wret; | |
db94535d CM |
2526 | u32 this_item_size; |
2527 | u32 old_left_item_size; | |
be0e5c09 | 2528 | |
34a38218 | 2529 | if (empty) |
99d8f83c | 2530 | nr = min(right_nritems, max_slot); |
34a38218 | 2531 | else |
99d8f83c | 2532 | nr = min(right_nritems - 1, max_slot); |
34a38218 CM |
2533 | |
2534 | for (i = 0; i < nr; i++) { | |
5f39d397 | 2535 | item = btrfs_item_nr(right, i); |
db94535d | 2536 | |
31840ae1 ZY |
2537 | if (!empty && push_items > 0) { |
2538 | if (path->slots[0] < i) | |
2539 | break; | |
2540 | if (path->slots[0] == i) { | |
2541 | int space = btrfs_leaf_free_space(root, right); | |
2542 | if (space + push_space * 2 > free_space) | |
2543 | break; | |
2544 | } | |
2545 | } | |
2546 | ||
be0e5c09 | 2547 | if (path->slots[0] == i) |
87b29b20 | 2548 | push_space += data_size; |
db94535d CM |
2549 | |
2550 | this_item_size = btrfs_item_size(right, item); | |
2551 | if (this_item_size + sizeof(*item) + push_space > free_space) | |
be0e5c09 | 2552 | break; |
db94535d | 2553 | |
be0e5c09 | 2554 | push_items++; |
db94535d CM |
2555 | push_space += this_item_size + sizeof(*item); |
2556 | } | |
2557 | ||
be0e5c09 | 2558 | if (push_items == 0) { |
925baedd CM |
2559 | ret = 1; |
2560 | goto out; | |
be0e5c09 | 2561 | } |
34a38218 | 2562 | if (!empty && push_items == btrfs_header_nritems(right)) |
a429e513 | 2563 | WARN_ON(1); |
5f39d397 | 2564 | |
be0e5c09 | 2565 | /* push data from right to left */ |
5f39d397 CM |
2566 | copy_extent_buffer(left, right, |
2567 | btrfs_item_nr_offset(btrfs_header_nritems(left)), | |
2568 | btrfs_item_nr_offset(0), | |
2569 | push_items * sizeof(struct btrfs_item)); | |
2570 | ||
123abc88 | 2571 | push_space = BTRFS_LEAF_DATA_SIZE(root) - |
d397712b | 2572 | btrfs_item_offset_nr(right, push_items - 1); |
5f39d397 CM |
2573 | |
2574 | copy_extent_buffer(left, right, btrfs_leaf_data(left) + | |
d6025579 CM |
2575 | leaf_data_end(root, left) - push_space, |
2576 | btrfs_leaf_data(right) + | |
5f39d397 | 2577 | btrfs_item_offset_nr(right, push_items - 1), |
d6025579 | 2578 | push_space); |
5f39d397 | 2579 | old_left_nritems = btrfs_header_nritems(left); |
87b29b20 | 2580 | BUG_ON(old_left_nritems <= 0); |
eb60ceac | 2581 | |
db94535d | 2582 | old_left_item_size = btrfs_item_offset_nr(left, old_left_nritems - 1); |
0783fcfc | 2583 | for (i = old_left_nritems; i < old_left_nritems + push_items; i++) { |
5f39d397 | 2584 | u32 ioff; |
db94535d | 2585 | |
5f39d397 | 2586 | item = btrfs_item_nr(left, i); |
db94535d | 2587 | |
5f39d397 CM |
2588 | ioff = btrfs_item_offset(left, item); |
2589 | btrfs_set_item_offset(left, item, | |
db94535d | 2590 | ioff - (BTRFS_LEAF_DATA_SIZE(root) - old_left_item_size)); |
be0e5c09 | 2591 | } |
5f39d397 | 2592 | btrfs_set_header_nritems(left, old_left_nritems + push_items); |
be0e5c09 CM |
2593 | |
2594 | /* fixup right node */ | |
34a38218 | 2595 | if (push_items > right_nritems) { |
d397712b CM |
2596 | printk(KERN_CRIT "push items %d nr %u\n", push_items, |
2597 | right_nritems); | |
34a38218 CM |
2598 | WARN_ON(1); |
2599 | } | |
2600 | ||
2601 | if (push_items < right_nritems) { | |
2602 | push_space = btrfs_item_offset_nr(right, push_items - 1) - | |
2603 | leaf_data_end(root, right); | |
2604 | memmove_extent_buffer(right, btrfs_leaf_data(right) + | |
2605 | BTRFS_LEAF_DATA_SIZE(root) - push_space, | |
2606 | btrfs_leaf_data(right) + | |
2607 | leaf_data_end(root, right), push_space); | |
2608 | ||
2609 | memmove_extent_buffer(right, btrfs_item_nr_offset(0), | |
5f39d397 CM |
2610 | btrfs_item_nr_offset(push_items), |
2611 | (btrfs_header_nritems(right) - push_items) * | |
2612 | sizeof(struct btrfs_item)); | |
34a38218 | 2613 | } |
eef1c494 Y |
2614 | right_nritems -= push_items; |
2615 | btrfs_set_header_nritems(right, right_nritems); | |
123abc88 | 2616 | push_space = BTRFS_LEAF_DATA_SIZE(root); |
5f39d397 CM |
2617 | for (i = 0; i < right_nritems; i++) { |
2618 | item = btrfs_item_nr(right, i); | |
db94535d | 2619 | |
db94535d CM |
2620 | push_space = push_space - btrfs_item_size(right, item); |
2621 | btrfs_set_item_offset(right, item, push_space); | |
2622 | } | |
eb60ceac | 2623 | |
5f39d397 | 2624 | btrfs_mark_buffer_dirty(left); |
34a38218 CM |
2625 | if (right_nritems) |
2626 | btrfs_mark_buffer_dirty(right); | |
f0486c68 YZ |
2627 | else |
2628 | clean_tree_block(trans, root, right); | |
098f59c2 | 2629 | |
5f39d397 CM |
2630 | btrfs_item_key(right, &disk_key, 0); |
2631 | wret = fixup_low_keys(trans, root, path, &disk_key, 1); | |
aa5d6bed CM |
2632 | if (wret) |
2633 | ret = wret; | |
be0e5c09 CM |
2634 | |
2635 | /* then fixup the leaf pointer in the path */ | |
2636 | if (path->slots[0] < push_items) { | |
2637 | path->slots[0] += old_left_nritems; | |
925baedd | 2638 | btrfs_tree_unlock(path->nodes[0]); |
5f39d397 CM |
2639 | free_extent_buffer(path->nodes[0]); |
2640 | path->nodes[0] = left; | |
be0e5c09 CM |
2641 | path->slots[1] -= 1; |
2642 | } else { | |
925baedd | 2643 | btrfs_tree_unlock(left); |
5f39d397 | 2644 | free_extent_buffer(left); |
be0e5c09 CM |
2645 | path->slots[0] -= push_items; |
2646 | } | |
eb60ceac | 2647 | BUG_ON(path->slots[0] < 0); |
aa5d6bed | 2648 | return ret; |
925baedd CM |
2649 | out: |
2650 | btrfs_tree_unlock(left); | |
2651 | free_extent_buffer(left); | |
2652 | return ret; | |
be0e5c09 CM |
2653 | } |
2654 | ||
44871b1b CM |
2655 | /* |
2656 | * push some data in the path leaf to the left, trying to free up at | |
2657 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
99d8f83c CM |
2658 | * |
2659 | * max_slot can put a limit on how far into the leaf we'll push items. The | |
2660 | * item at 'max_slot' won't be touched. Use (u32)-1 to make us push all the | |
2661 | * items | |
44871b1b CM |
2662 | */ |
2663 | static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root | |
99d8f83c CM |
2664 | *root, struct btrfs_path *path, int min_data_size, |
2665 | int data_size, int empty, u32 max_slot) | |
44871b1b CM |
2666 | { |
2667 | struct extent_buffer *right = path->nodes[0]; | |
2668 | struct extent_buffer *left; | |
2669 | int slot; | |
2670 | int free_space; | |
2671 | u32 right_nritems; | |
2672 | int ret = 0; | |
2673 | ||
2674 | slot = path->slots[1]; | |
2675 | if (slot == 0) | |
2676 | return 1; | |
2677 | if (!path->nodes[1]) | |
2678 | return 1; | |
2679 | ||
2680 | right_nritems = btrfs_header_nritems(right); | |
2681 | if (right_nritems == 0) | |
2682 | return 1; | |
2683 | ||
2684 | btrfs_assert_tree_locked(path->nodes[1]); | |
2685 | ||
2686 | left = read_node_slot(root, path->nodes[1], slot - 1); | |
91ca338d TI |
2687 | if (left == NULL) |
2688 | return 1; | |
2689 | ||
44871b1b CM |
2690 | btrfs_tree_lock(left); |
2691 | btrfs_set_lock_blocking(left); | |
2692 | ||
2693 | free_space = btrfs_leaf_free_space(root, left); | |
2694 | if (free_space < data_size) { | |
2695 | ret = 1; | |
2696 | goto out; | |
2697 | } | |
2698 | ||
2699 | /* cow and double check */ | |
2700 | ret = btrfs_cow_block(trans, root, left, | |
2701 | path->nodes[1], slot - 1, &left); | |
2702 | if (ret) { | |
2703 | /* we hit -ENOSPC, but it isn't fatal here */ | |
2704 | ret = 1; | |
2705 | goto out; | |
2706 | } | |
2707 | ||
2708 | free_space = btrfs_leaf_free_space(root, left); | |
2709 | if (free_space < data_size) { | |
2710 | ret = 1; | |
2711 | goto out; | |
2712 | } | |
2713 | ||
99d8f83c CM |
2714 | return __push_leaf_left(trans, root, path, min_data_size, |
2715 | empty, left, free_space, right_nritems, | |
2716 | max_slot); | |
44871b1b CM |
2717 | out: |
2718 | btrfs_tree_unlock(left); | |
2719 | free_extent_buffer(left); | |
2720 | return ret; | |
2721 | } | |
2722 | ||
2723 | /* | |
2724 | * split the path's leaf in two, making sure there is at least data_size | |
2725 | * available for the resulting leaf level of the path. | |
2726 | * | |
2727 | * returns 0 if all went well and < 0 on failure. | |
2728 | */ | |
2729 | static noinline int copy_for_split(struct btrfs_trans_handle *trans, | |
2730 | struct btrfs_root *root, | |
2731 | struct btrfs_path *path, | |
2732 | struct extent_buffer *l, | |
2733 | struct extent_buffer *right, | |
2734 | int slot, int mid, int nritems) | |
2735 | { | |
2736 | int data_copy_size; | |
2737 | int rt_data_off; | |
2738 | int i; | |
2739 | int ret = 0; | |
2740 | int wret; | |
2741 | struct btrfs_disk_key disk_key; | |
2742 | ||
2743 | nritems = nritems - mid; | |
2744 | btrfs_set_header_nritems(right, nritems); | |
2745 | data_copy_size = btrfs_item_end_nr(l, mid) - leaf_data_end(root, l); | |
2746 | ||
2747 | copy_extent_buffer(right, l, btrfs_item_nr_offset(0), | |
2748 | btrfs_item_nr_offset(mid), | |
2749 | nritems * sizeof(struct btrfs_item)); | |
2750 | ||
2751 | copy_extent_buffer(right, l, | |
2752 | btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) - | |
2753 | data_copy_size, btrfs_leaf_data(l) + | |
2754 | leaf_data_end(root, l), data_copy_size); | |
2755 | ||
2756 | rt_data_off = BTRFS_LEAF_DATA_SIZE(root) - | |
2757 | btrfs_item_end_nr(l, mid); | |
2758 | ||
2759 | for (i = 0; i < nritems; i++) { | |
2760 | struct btrfs_item *item = btrfs_item_nr(right, i); | |
2761 | u32 ioff; | |
2762 | ||
44871b1b CM |
2763 | ioff = btrfs_item_offset(right, item); |
2764 | btrfs_set_item_offset(right, item, ioff + rt_data_off); | |
2765 | } | |
2766 | ||
44871b1b CM |
2767 | btrfs_set_header_nritems(l, mid); |
2768 | ret = 0; | |
2769 | btrfs_item_key(right, &disk_key, 0); | |
2770 | wret = insert_ptr(trans, root, path, &disk_key, right->start, | |
2771 | path->slots[1] + 1, 1); | |
2772 | if (wret) | |
2773 | ret = wret; | |
2774 | ||
2775 | btrfs_mark_buffer_dirty(right); | |
2776 | btrfs_mark_buffer_dirty(l); | |
2777 | BUG_ON(path->slots[0] != slot); | |
2778 | ||
44871b1b CM |
2779 | if (mid <= slot) { |
2780 | btrfs_tree_unlock(path->nodes[0]); | |
2781 | free_extent_buffer(path->nodes[0]); | |
2782 | path->nodes[0] = right; | |
2783 | path->slots[0] -= mid; | |
2784 | path->slots[1] += 1; | |
2785 | } else { | |
2786 | btrfs_tree_unlock(right); | |
2787 | free_extent_buffer(right); | |
2788 | } | |
2789 | ||
2790 | BUG_ON(path->slots[0] < 0); | |
2791 | ||
2792 | return ret; | |
2793 | } | |
2794 | ||
99d8f83c CM |
2795 | /* |
2796 | * double splits happen when we need to insert a big item in the middle | |
2797 | * of a leaf. A double split can leave us with 3 mostly empty leaves: | |
2798 | * leaf: [ slots 0 - N] [ our target ] [ N + 1 - total in leaf ] | |
2799 | * A B C | |
2800 | * | |
2801 | * We avoid this by trying to push the items on either side of our target | |
2802 | * into the adjacent leaves. If all goes well we can avoid the double split | |
2803 | * completely. | |
2804 | */ | |
2805 | static noinline int push_for_double_split(struct btrfs_trans_handle *trans, | |
2806 | struct btrfs_root *root, | |
2807 | struct btrfs_path *path, | |
2808 | int data_size) | |
2809 | { | |
2810 | int ret; | |
2811 | int progress = 0; | |
2812 | int slot; | |
2813 | u32 nritems; | |
2814 | ||
2815 | slot = path->slots[0]; | |
2816 | ||
2817 | /* | |
2818 | * try to push all the items after our slot into the | |
2819 | * right leaf | |
2820 | */ | |
2821 | ret = push_leaf_right(trans, root, path, 1, data_size, 0, slot); | |
2822 | if (ret < 0) | |
2823 | return ret; | |
2824 | ||
2825 | if (ret == 0) | |
2826 | progress++; | |
2827 | ||
2828 | nritems = btrfs_header_nritems(path->nodes[0]); | |
2829 | /* | |
2830 | * our goal is to get our slot at the start or end of a leaf. If | |
2831 | * we've done so we're done | |
2832 | */ | |
2833 | if (path->slots[0] == 0 || path->slots[0] == nritems) | |
2834 | return 0; | |
2835 | ||
2836 | if (btrfs_leaf_free_space(root, path->nodes[0]) >= data_size) | |
2837 | return 0; | |
2838 | ||
2839 | /* try to push all the items before our slot into the next leaf */ | |
2840 | slot = path->slots[0]; | |
2841 | ret = push_leaf_left(trans, root, path, 1, data_size, 0, slot); | |
2842 | if (ret < 0) | |
2843 | return ret; | |
2844 | ||
2845 | if (ret == 0) | |
2846 | progress++; | |
2847 | ||
2848 | if (progress) | |
2849 | return 0; | |
2850 | return 1; | |
2851 | } | |
2852 | ||
74123bd7 CM |
2853 | /* |
2854 | * split the path's leaf in two, making sure there is at least data_size | |
2855 | * available for the resulting leaf level of the path. | |
aa5d6bed CM |
2856 | * |
2857 | * returns 0 if all went well and < 0 on failure. | |
74123bd7 | 2858 | */ |
e02119d5 CM |
2859 | static noinline int split_leaf(struct btrfs_trans_handle *trans, |
2860 | struct btrfs_root *root, | |
2861 | struct btrfs_key *ins_key, | |
2862 | struct btrfs_path *path, int data_size, | |
2863 | int extend) | |
be0e5c09 | 2864 | { |
5d4f98a2 | 2865 | struct btrfs_disk_key disk_key; |
5f39d397 | 2866 | struct extent_buffer *l; |
7518a238 | 2867 | u32 nritems; |
eb60ceac CM |
2868 | int mid; |
2869 | int slot; | |
5f39d397 | 2870 | struct extent_buffer *right; |
d4dbff95 | 2871 | int ret = 0; |
aa5d6bed | 2872 | int wret; |
5d4f98a2 | 2873 | int split; |
cc0c5538 | 2874 | int num_doubles = 0; |
99d8f83c | 2875 | int tried_avoid_double = 0; |
aa5d6bed | 2876 | |
a5719521 YZ |
2877 | l = path->nodes[0]; |
2878 | slot = path->slots[0]; | |
2879 | if (extend && data_size + btrfs_item_size_nr(l, slot) + | |
2880 | sizeof(struct btrfs_item) > BTRFS_LEAF_DATA_SIZE(root)) | |
2881 | return -EOVERFLOW; | |
2882 | ||
40689478 | 2883 | /* first try to make some room by pushing left and right */ |
99d8f83c CM |
2884 | if (data_size) { |
2885 | wret = push_leaf_right(trans, root, path, data_size, | |
2886 | data_size, 0, 0); | |
d397712b | 2887 | if (wret < 0) |
eaee50e8 | 2888 | return wret; |
3685f791 | 2889 | if (wret) { |
99d8f83c CM |
2890 | wret = push_leaf_left(trans, root, path, data_size, |
2891 | data_size, 0, (u32)-1); | |
3685f791 CM |
2892 | if (wret < 0) |
2893 | return wret; | |
2894 | } | |
2895 | l = path->nodes[0]; | |
aa5d6bed | 2896 | |
3685f791 | 2897 | /* did the pushes work? */ |
87b29b20 | 2898 | if (btrfs_leaf_free_space(root, l) >= data_size) |
3685f791 | 2899 | return 0; |
3326d1b0 | 2900 | } |
aa5d6bed | 2901 | |
5c680ed6 | 2902 | if (!path->nodes[1]) { |
e089f05c | 2903 | ret = insert_new_root(trans, root, path, 1); |
5c680ed6 CM |
2904 | if (ret) |
2905 | return ret; | |
2906 | } | |
cc0c5538 | 2907 | again: |
5d4f98a2 | 2908 | split = 1; |
cc0c5538 | 2909 | l = path->nodes[0]; |
eb60ceac | 2910 | slot = path->slots[0]; |
5f39d397 | 2911 | nritems = btrfs_header_nritems(l); |
d397712b | 2912 | mid = (nritems + 1) / 2; |
54aa1f4d | 2913 | |
5d4f98a2 YZ |
2914 | if (mid <= slot) { |
2915 | if (nritems == 1 || | |
2916 | leaf_space_used(l, mid, nritems - mid) + data_size > | |
2917 | BTRFS_LEAF_DATA_SIZE(root)) { | |
2918 | if (slot >= nritems) { | |
2919 | split = 0; | |
2920 | } else { | |
2921 | mid = slot; | |
2922 | if (mid != nritems && | |
2923 | leaf_space_used(l, mid, nritems - mid) + | |
2924 | data_size > BTRFS_LEAF_DATA_SIZE(root)) { | |
99d8f83c CM |
2925 | if (data_size && !tried_avoid_double) |
2926 | goto push_for_double; | |
5d4f98a2 YZ |
2927 | split = 2; |
2928 | } | |
2929 | } | |
2930 | } | |
2931 | } else { | |
2932 | if (leaf_space_used(l, 0, mid) + data_size > | |
2933 | BTRFS_LEAF_DATA_SIZE(root)) { | |
2934 | if (!extend && data_size && slot == 0) { | |
2935 | split = 0; | |
2936 | } else if ((extend || !data_size) && slot == 0) { | |
2937 | mid = 1; | |
2938 | } else { | |
2939 | mid = slot; | |
2940 | if (mid != nritems && | |
2941 | leaf_space_used(l, mid, nritems - mid) + | |
2942 | data_size > BTRFS_LEAF_DATA_SIZE(root)) { | |
99d8f83c CM |
2943 | if (data_size && !tried_avoid_double) |
2944 | goto push_for_double; | |
5d4f98a2 YZ |
2945 | split = 2 ; |
2946 | } | |
2947 | } | |
2948 | } | |
2949 | } | |
2950 | ||
2951 | if (split == 0) | |
2952 | btrfs_cpu_key_to_disk(&disk_key, ins_key); | |
2953 | else | |
2954 | btrfs_item_key(l, &disk_key, mid); | |
2955 | ||
2956 | right = btrfs_alloc_free_block(trans, root, root->leafsize, 0, | |
31840ae1 | 2957 | root->root_key.objectid, |
5d4f98a2 | 2958 | &disk_key, 0, l->start, 0); |
f0486c68 | 2959 | if (IS_ERR(right)) |
5f39d397 | 2960 | return PTR_ERR(right); |
f0486c68 YZ |
2961 | |
2962 | root_add_used(root, root->leafsize); | |
5f39d397 CM |
2963 | |
2964 | memset_extent_buffer(right, 0, 0, sizeof(struct btrfs_header)); | |
db94535d | 2965 | btrfs_set_header_bytenr(right, right->start); |
5f39d397 | 2966 | btrfs_set_header_generation(right, trans->transid); |
5d4f98a2 | 2967 | btrfs_set_header_backref_rev(right, BTRFS_MIXED_BACKREF_REV); |
5f39d397 CM |
2968 | btrfs_set_header_owner(right, root->root_key.objectid); |
2969 | btrfs_set_header_level(right, 0); | |
2970 | write_extent_buffer(right, root->fs_info->fsid, | |
2971 | (unsigned long)btrfs_header_fsid(right), | |
2972 | BTRFS_FSID_SIZE); | |
e17cade2 CM |
2973 | |
2974 | write_extent_buffer(right, root->fs_info->chunk_tree_uuid, | |
2975 | (unsigned long)btrfs_header_chunk_tree_uuid(right), | |
2976 | BTRFS_UUID_SIZE); | |
44871b1b | 2977 | |
5d4f98a2 YZ |
2978 | if (split == 0) { |
2979 | if (mid <= slot) { | |
2980 | btrfs_set_header_nritems(right, 0); | |
2981 | wret = insert_ptr(trans, root, path, | |
2982 | &disk_key, right->start, | |
2983 | path->slots[1] + 1, 1); | |
2984 | if (wret) | |
2985 | ret = wret; | |
925baedd | 2986 | |
5d4f98a2 YZ |
2987 | btrfs_tree_unlock(path->nodes[0]); |
2988 | free_extent_buffer(path->nodes[0]); | |
2989 | path->nodes[0] = right; | |
2990 | path->slots[0] = 0; | |
2991 | path->slots[1] += 1; | |
2992 | } else { | |
2993 | btrfs_set_header_nritems(right, 0); | |
2994 | wret = insert_ptr(trans, root, path, | |
2995 | &disk_key, | |
2996 | right->start, | |
2997 | path->slots[1], 1); | |
2998 | if (wret) | |
2999 | ret = wret; | |
3000 | btrfs_tree_unlock(path->nodes[0]); | |
3001 | free_extent_buffer(path->nodes[0]); | |
3002 | path->nodes[0] = right; | |
3003 | path->slots[0] = 0; | |
3004 | if (path->slots[1] == 0) { | |
3005 | wret = fixup_low_keys(trans, root, | |
3006 | path, &disk_key, 1); | |
d4dbff95 CM |
3007 | if (wret) |
3008 | ret = wret; | |
5ee78ac7 | 3009 | } |
d4dbff95 | 3010 | } |
5d4f98a2 YZ |
3011 | btrfs_mark_buffer_dirty(right); |
3012 | return ret; | |
d4dbff95 | 3013 | } |
74123bd7 | 3014 | |
44871b1b | 3015 | ret = copy_for_split(trans, root, path, l, right, slot, mid, nritems); |
31840ae1 ZY |
3016 | BUG_ON(ret); |
3017 | ||
5d4f98a2 | 3018 | if (split == 2) { |
cc0c5538 CM |
3019 | BUG_ON(num_doubles != 0); |
3020 | num_doubles++; | |
3021 | goto again; | |
a429e513 | 3022 | } |
44871b1b | 3023 | |
be0e5c09 | 3024 | return ret; |
99d8f83c CM |
3025 | |
3026 | push_for_double: | |
3027 | push_for_double_split(trans, root, path, data_size); | |
3028 | tried_avoid_double = 1; | |
3029 | if (btrfs_leaf_free_space(root, path->nodes[0]) >= data_size) | |
3030 | return 0; | |
3031 | goto again; | |
be0e5c09 CM |
3032 | } |
3033 | ||
ad48fd75 YZ |
3034 | static noinline int setup_leaf_for_split(struct btrfs_trans_handle *trans, |
3035 | struct btrfs_root *root, | |
3036 | struct btrfs_path *path, int ins_len) | |
459931ec | 3037 | { |
ad48fd75 | 3038 | struct btrfs_key key; |
459931ec | 3039 | struct extent_buffer *leaf; |
ad48fd75 YZ |
3040 | struct btrfs_file_extent_item *fi; |
3041 | u64 extent_len = 0; | |
3042 | u32 item_size; | |
3043 | int ret; | |
459931ec CM |
3044 | |
3045 | leaf = path->nodes[0]; | |
ad48fd75 YZ |
3046 | btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
3047 | ||
3048 | BUG_ON(key.type != BTRFS_EXTENT_DATA_KEY && | |
3049 | key.type != BTRFS_EXTENT_CSUM_KEY); | |
3050 | ||
3051 | if (btrfs_leaf_free_space(root, leaf) >= ins_len) | |
3052 | return 0; | |
459931ec CM |
3053 | |
3054 | item_size = btrfs_item_size_nr(leaf, path->slots[0]); | |
ad48fd75 YZ |
3055 | if (key.type == BTRFS_EXTENT_DATA_KEY) { |
3056 | fi = btrfs_item_ptr(leaf, path->slots[0], | |
3057 | struct btrfs_file_extent_item); | |
3058 | extent_len = btrfs_file_extent_num_bytes(leaf, fi); | |
3059 | } | |
b3b4aa74 | 3060 | btrfs_release_path(path); |
459931ec | 3061 | |
459931ec | 3062 | path->keep_locks = 1; |
ad48fd75 YZ |
3063 | path->search_for_split = 1; |
3064 | ret = btrfs_search_slot(trans, root, &key, path, 0, 1); | |
459931ec | 3065 | path->search_for_split = 0; |
ad48fd75 YZ |
3066 | if (ret < 0) |
3067 | goto err; | |
459931ec | 3068 | |
ad48fd75 YZ |
3069 | ret = -EAGAIN; |
3070 | leaf = path->nodes[0]; | |
459931ec | 3071 | /* if our item isn't there or got smaller, return now */ |
ad48fd75 YZ |
3072 | if (ret > 0 || item_size != btrfs_item_size_nr(leaf, path->slots[0])) |
3073 | goto err; | |
3074 | ||
109f6aef CM |
3075 | /* the leaf has changed, it now has room. return now */ |
3076 | if (btrfs_leaf_free_space(root, path->nodes[0]) >= ins_len) | |
3077 | goto err; | |
3078 | ||
ad48fd75 YZ |
3079 | if (key.type == BTRFS_EXTENT_DATA_KEY) { |
3080 | fi = btrfs_item_ptr(leaf, path->slots[0], | |
3081 | struct btrfs_file_extent_item); | |
3082 | if (extent_len != btrfs_file_extent_num_bytes(leaf, fi)) | |
3083 | goto err; | |
459931ec CM |
3084 | } |
3085 | ||
b9473439 | 3086 | btrfs_set_path_blocking(path); |
ad48fd75 | 3087 | ret = split_leaf(trans, root, &key, path, ins_len, 1); |
f0486c68 YZ |
3088 | if (ret) |
3089 | goto err; | |
459931ec | 3090 | |
ad48fd75 | 3091 | path->keep_locks = 0; |
b9473439 | 3092 | btrfs_unlock_up_safe(path, 1); |
ad48fd75 YZ |
3093 | return 0; |
3094 | err: | |
3095 | path->keep_locks = 0; | |
3096 | return ret; | |
3097 | } | |
3098 | ||
3099 | static noinline int split_item(struct btrfs_trans_handle *trans, | |
3100 | struct btrfs_root *root, | |
3101 | struct btrfs_path *path, | |
3102 | struct btrfs_key *new_key, | |
3103 | unsigned long split_offset) | |
3104 | { | |
3105 | struct extent_buffer *leaf; | |
3106 | struct btrfs_item *item; | |
3107 | struct btrfs_item *new_item; | |
3108 | int slot; | |
3109 | char *buf; | |
3110 | u32 nritems; | |
3111 | u32 item_size; | |
3112 | u32 orig_offset; | |
3113 | struct btrfs_disk_key disk_key; | |
3114 | ||
b9473439 CM |
3115 | leaf = path->nodes[0]; |
3116 | BUG_ON(btrfs_leaf_free_space(root, leaf) < sizeof(struct btrfs_item)); | |
3117 | ||
b4ce94de CM |
3118 | btrfs_set_path_blocking(path); |
3119 | ||
459931ec CM |
3120 | item = btrfs_item_nr(leaf, path->slots[0]); |
3121 | orig_offset = btrfs_item_offset(leaf, item); | |
3122 | item_size = btrfs_item_size(leaf, item); | |
3123 | ||
459931ec | 3124 | buf = kmalloc(item_size, GFP_NOFS); |
ad48fd75 YZ |
3125 | if (!buf) |
3126 | return -ENOMEM; | |
3127 | ||
459931ec CM |
3128 | read_extent_buffer(leaf, buf, btrfs_item_ptr_offset(leaf, |
3129 | path->slots[0]), item_size); | |
459931ec | 3130 | |
ad48fd75 | 3131 | slot = path->slots[0] + 1; |
459931ec | 3132 | nritems = btrfs_header_nritems(leaf); |
459931ec CM |
3133 | if (slot != nritems) { |
3134 | /* shift the items */ | |
3135 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + 1), | |
ad48fd75 YZ |
3136 | btrfs_item_nr_offset(slot), |
3137 | (nritems - slot) * sizeof(struct btrfs_item)); | |
459931ec CM |
3138 | } |
3139 | ||
3140 | btrfs_cpu_key_to_disk(&disk_key, new_key); | |
3141 | btrfs_set_item_key(leaf, &disk_key, slot); | |
3142 | ||
3143 | new_item = btrfs_item_nr(leaf, slot); | |
3144 | ||
3145 | btrfs_set_item_offset(leaf, new_item, orig_offset); | |
3146 | btrfs_set_item_size(leaf, new_item, item_size - split_offset); | |
3147 | ||
3148 | btrfs_set_item_offset(leaf, item, | |
3149 | orig_offset + item_size - split_offset); | |
3150 | btrfs_set_item_size(leaf, item, split_offset); | |
3151 | ||
3152 | btrfs_set_header_nritems(leaf, nritems + 1); | |
3153 | ||
3154 | /* write the data for the start of the original item */ | |
3155 | write_extent_buffer(leaf, buf, | |
3156 | btrfs_item_ptr_offset(leaf, path->slots[0]), | |
3157 | split_offset); | |
3158 | ||
3159 | /* write the data for the new item */ | |
3160 | write_extent_buffer(leaf, buf + split_offset, | |
3161 | btrfs_item_ptr_offset(leaf, slot), | |
3162 | item_size - split_offset); | |
3163 | btrfs_mark_buffer_dirty(leaf); | |
3164 | ||
ad48fd75 | 3165 | BUG_ON(btrfs_leaf_free_space(root, leaf) < 0); |
459931ec | 3166 | kfree(buf); |
ad48fd75 YZ |
3167 | return 0; |
3168 | } | |
3169 | ||
3170 | /* | |
3171 | * This function splits a single item into two items, | |
3172 | * giving 'new_key' to the new item and splitting the | |
3173 | * old one at split_offset (from the start of the item). | |
3174 | * | |
3175 | * The path may be released by this operation. After | |
3176 | * the split, the path is pointing to the old item. The | |
3177 | * new item is going to be in the same node as the old one. | |
3178 | * | |
3179 | * Note, the item being split must be smaller enough to live alone on | |
3180 | * a tree block with room for one extra struct btrfs_item | |
3181 | * | |
3182 | * This allows us to split the item in place, keeping a lock on the | |
3183 | * leaf the entire time. | |
3184 | */ | |
3185 | int btrfs_split_item(struct btrfs_trans_handle *trans, | |
3186 | struct btrfs_root *root, | |
3187 | struct btrfs_path *path, | |
3188 | struct btrfs_key *new_key, | |
3189 | unsigned long split_offset) | |
3190 | { | |
3191 | int ret; | |
3192 | ret = setup_leaf_for_split(trans, root, path, | |
3193 | sizeof(struct btrfs_item)); | |
3194 | if (ret) | |
3195 | return ret; | |
3196 | ||
3197 | ret = split_item(trans, root, path, new_key, split_offset); | |
459931ec CM |
3198 | return ret; |
3199 | } | |
3200 | ||
ad48fd75 YZ |
3201 | /* |
3202 | * This function duplicate a item, giving 'new_key' to the new item. | |
3203 | * It guarantees both items live in the same tree leaf and the new item | |
3204 | * is contiguous with the original item. | |
3205 | * | |
3206 | * This allows us to split file extent in place, keeping a lock on the | |
3207 | * leaf the entire time. | |
3208 | */ | |
3209 | int btrfs_duplicate_item(struct btrfs_trans_handle *trans, | |
3210 | struct btrfs_root *root, | |
3211 | struct btrfs_path *path, | |
3212 | struct btrfs_key *new_key) | |
3213 | { | |
3214 | struct extent_buffer *leaf; | |
3215 | int ret; | |
3216 | u32 item_size; | |
3217 | ||
3218 | leaf = path->nodes[0]; | |
3219 | item_size = btrfs_item_size_nr(leaf, path->slots[0]); | |
3220 | ret = setup_leaf_for_split(trans, root, path, | |
3221 | item_size + sizeof(struct btrfs_item)); | |
3222 | if (ret) | |
3223 | return ret; | |
3224 | ||
3225 | path->slots[0]++; | |
3226 | ret = setup_items_for_insert(trans, root, path, new_key, &item_size, | |
3227 | item_size, item_size + | |
3228 | sizeof(struct btrfs_item), 1); | |
3229 | BUG_ON(ret); | |
3230 | ||
3231 | leaf = path->nodes[0]; | |
3232 | memcpy_extent_buffer(leaf, | |
3233 | btrfs_item_ptr_offset(leaf, path->slots[0]), | |
3234 | btrfs_item_ptr_offset(leaf, path->slots[0] - 1), | |
3235 | item_size); | |
3236 | return 0; | |
3237 | } | |
3238 | ||
d352ac68 CM |
3239 | /* |
3240 | * make the item pointed to by the path smaller. new_size indicates | |
3241 | * how small to make it, and from_end tells us if we just chop bytes | |
3242 | * off the end of the item or if we shift the item to chop bytes off | |
3243 | * the front. | |
3244 | */ | |
b18c6685 CM |
3245 | int btrfs_truncate_item(struct btrfs_trans_handle *trans, |
3246 | struct btrfs_root *root, | |
3247 | struct btrfs_path *path, | |
179e29e4 | 3248 | u32 new_size, int from_end) |
b18c6685 | 3249 | { |
b18c6685 | 3250 | int slot; |
5f39d397 CM |
3251 | struct extent_buffer *leaf; |
3252 | struct btrfs_item *item; | |
b18c6685 CM |
3253 | u32 nritems; |
3254 | unsigned int data_end; | |
3255 | unsigned int old_data_start; | |
3256 | unsigned int old_size; | |
3257 | unsigned int size_diff; | |
3258 | int i; | |
3259 | ||
5f39d397 | 3260 | leaf = path->nodes[0]; |
179e29e4 CM |
3261 | slot = path->slots[0]; |
3262 | ||
3263 | old_size = btrfs_item_size_nr(leaf, slot); | |
3264 | if (old_size == new_size) | |
3265 | return 0; | |
b18c6685 | 3266 | |
5f39d397 | 3267 | nritems = btrfs_header_nritems(leaf); |
b18c6685 CM |
3268 | data_end = leaf_data_end(root, leaf); |
3269 | ||
5f39d397 | 3270 | old_data_start = btrfs_item_offset_nr(leaf, slot); |
179e29e4 | 3271 | |
b18c6685 CM |
3272 | size_diff = old_size - new_size; |
3273 | ||
3274 | BUG_ON(slot < 0); | |
3275 | BUG_ON(slot >= nritems); | |
3276 | ||
3277 | /* | |
3278 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
3279 | */ | |
3280 | /* first correct the data pointers */ | |
3281 | for (i = slot; i < nritems; i++) { | |
5f39d397 CM |
3282 | u32 ioff; |
3283 | item = btrfs_item_nr(leaf, i); | |
db94535d | 3284 | |
5f39d397 CM |
3285 | ioff = btrfs_item_offset(leaf, item); |
3286 | btrfs_set_item_offset(leaf, item, ioff + size_diff); | |
b18c6685 | 3287 | } |
db94535d | 3288 | |
b18c6685 | 3289 | /* shift the data */ |
179e29e4 CM |
3290 | if (from_end) { |
3291 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + | |
3292 | data_end + size_diff, btrfs_leaf_data(leaf) + | |
3293 | data_end, old_data_start + new_size - data_end); | |
3294 | } else { | |
3295 | struct btrfs_disk_key disk_key; | |
3296 | u64 offset; | |
3297 | ||
3298 | btrfs_item_key(leaf, &disk_key, slot); | |
3299 | ||
3300 | if (btrfs_disk_key_type(&disk_key) == BTRFS_EXTENT_DATA_KEY) { | |
3301 | unsigned long ptr; | |
3302 | struct btrfs_file_extent_item *fi; | |
3303 | ||
3304 | fi = btrfs_item_ptr(leaf, slot, | |
3305 | struct btrfs_file_extent_item); | |
3306 | fi = (struct btrfs_file_extent_item *)( | |
3307 | (unsigned long)fi - size_diff); | |
3308 | ||
3309 | if (btrfs_file_extent_type(leaf, fi) == | |
3310 | BTRFS_FILE_EXTENT_INLINE) { | |
3311 | ptr = btrfs_item_ptr_offset(leaf, slot); | |
3312 | memmove_extent_buffer(leaf, ptr, | |
d397712b CM |
3313 | (unsigned long)fi, |
3314 | offsetof(struct btrfs_file_extent_item, | |
179e29e4 CM |
3315 | disk_bytenr)); |
3316 | } | |
3317 | } | |
3318 | ||
3319 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + | |
3320 | data_end + size_diff, btrfs_leaf_data(leaf) + | |
3321 | data_end, old_data_start - data_end); | |
3322 | ||
3323 | offset = btrfs_disk_key_offset(&disk_key); | |
3324 | btrfs_set_disk_key_offset(&disk_key, offset + size_diff); | |
3325 | btrfs_set_item_key(leaf, &disk_key, slot); | |
3326 | if (slot == 0) | |
3327 | fixup_low_keys(trans, root, path, &disk_key, 1); | |
3328 | } | |
5f39d397 CM |
3329 | |
3330 | item = btrfs_item_nr(leaf, slot); | |
3331 | btrfs_set_item_size(leaf, item, new_size); | |
3332 | btrfs_mark_buffer_dirty(leaf); | |
b18c6685 | 3333 | |
5f39d397 CM |
3334 | if (btrfs_leaf_free_space(root, leaf) < 0) { |
3335 | btrfs_print_leaf(root, leaf); | |
b18c6685 | 3336 | BUG(); |
5f39d397 | 3337 | } |
1cd30799 | 3338 | return 0; |
b18c6685 CM |
3339 | } |
3340 | ||
d352ac68 CM |
3341 | /* |
3342 | * make the item pointed to by the path bigger, data_size is the new size. | |
3343 | */ | |
5f39d397 CM |
3344 | int btrfs_extend_item(struct btrfs_trans_handle *trans, |
3345 | struct btrfs_root *root, struct btrfs_path *path, | |
3346 | u32 data_size) | |
6567e837 | 3347 | { |
6567e837 | 3348 | int slot; |
5f39d397 CM |
3349 | struct extent_buffer *leaf; |
3350 | struct btrfs_item *item; | |
6567e837 CM |
3351 | u32 nritems; |
3352 | unsigned int data_end; | |
3353 | unsigned int old_data; | |
3354 | unsigned int old_size; | |
3355 | int i; | |
3356 | ||
5f39d397 | 3357 | leaf = path->nodes[0]; |
6567e837 | 3358 | |
5f39d397 | 3359 | nritems = btrfs_header_nritems(leaf); |
6567e837 CM |
3360 | data_end = leaf_data_end(root, leaf); |
3361 | ||
5f39d397 CM |
3362 | if (btrfs_leaf_free_space(root, leaf) < data_size) { |
3363 | btrfs_print_leaf(root, leaf); | |
6567e837 | 3364 | BUG(); |
5f39d397 | 3365 | } |
6567e837 | 3366 | slot = path->slots[0]; |
5f39d397 | 3367 | old_data = btrfs_item_end_nr(leaf, slot); |
6567e837 CM |
3368 | |
3369 | BUG_ON(slot < 0); | |
3326d1b0 CM |
3370 | if (slot >= nritems) { |
3371 | btrfs_print_leaf(root, leaf); | |
d397712b CM |
3372 | printk(KERN_CRIT "slot %d too large, nritems %d\n", |
3373 | slot, nritems); | |
3326d1b0 CM |
3374 | BUG_ON(1); |
3375 | } | |
6567e837 CM |
3376 | |
3377 | /* | |
3378 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
3379 | */ | |
3380 | /* first correct the data pointers */ | |
3381 | for (i = slot; i < nritems; i++) { | |
5f39d397 CM |
3382 | u32 ioff; |
3383 | item = btrfs_item_nr(leaf, i); | |
db94535d | 3384 | |
5f39d397 CM |
3385 | ioff = btrfs_item_offset(leaf, item); |
3386 | btrfs_set_item_offset(leaf, item, ioff - data_size); | |
6567e837 | 3387 | } |
5f39d397 | 3388 | |
6567e837 | 3389 | /* shift the data */ |
5f39d397 | 3390 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + |
6567e837 CM |
3391 | data_end - data_size, btrfs_leaf_data(leaf) + |
3392 | data_end, old_data - data_end); | |
5f39d397 | 3393 | |
6567e837 | 3394 | data_end = old_data; |
5f39d397 CM |
3395 | old_size = btrfs_item_size_nr(leaf, slot); |
3396 | item = btrfs_item_nr(leaf, slot); | |
3397 | btrfs_set_item_size(leaf, item, old_size + data_size); | |
3398 | btrfs_mark_buffer_dirty(leaf); | |
6567e837 | 3399 | |
5f39d397 CM |
3400 | if (btrfs_leaf_free_space(root, leaf) < 0) { |
3401 | btrfs_print_leaf(root, leaf); | |
6567e837 | 3402 | BUG(); |
5f39d397 | 3403 | } |
1cd30799 | 3404 | return 0; |
6567e837 CM |
3405 | } |
3406 | ||
f3465ca4 JB |
3407 | /* |
3408 | * Given a key and some data, insert items into the tree. | |
3409 | * This does all the path init required, making room in the tree if needed. | |
3410 | * Returns the number of keys that were inserted. | |
3411 | */ | |
3412 | int btrfs_insert_some_items(struct btrfs_trans_handle *trans, | |
3413 | struct btrfs_root *root, | |
3414 | struct btrfs_path *path, | |
3415 | struct btrfs_key *cpu_key, u32 *data_size, | |
3416 | int nr) | |
3417 | { | |
3418 | struct extent_buffer *leaf; | |
3419 | struct btrfs_item *item; | |
3420 | int ret = 0; | |
3421 | int slot; | |
f3465ca4 JB |
3422 | int i; |
3423 | u32 nritems; | |
3424 | u32 total_data = 0; | |
3425 | u32 total_size = 0; | |
3426 | unsigned int data_end; | |
3427 | struct btrfs_disk_key disk_key; | |
3428 | struct btrfs_key found_key; | |
3429 | ||
87b29b20 YZ |
3430 | for (i = 0; i < nr; i++) { |
3431 | if (total_size + data_size[i] + sizeof(struct btrfs_item) > | |
3432 | BTRFS_LEAF_DATA_SIZE(root)) { | |
3433 | break; | |
3434 | nr = i; | |
3435 | } | |
f3465ca4 | 3436 | total_data += data_size[i]; |
87b29b20 YZ |
3437 | total_size += data_size[i] + sizeof(struct btrfs_item); |
3438 | } | |
3439 | BUG_ON(nr == 0); | |
f3465ca4 | 3440 | |
f3465ca4 JB |
3441 | ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1); |
3442 | if (ret == 0) | |
3443 | return -EEXIST; | |
3444 | if (ret < 0) | |
3445 | goto out; | |
3446 | ||
f3465ca4 JB |
3447 | leaf = path->nodes[0]; |
3448 | ||
3449 | nritems = btrfs_header_nritems(leaf); | |
3450 | data_end = leaf_data_end(root, leaf); | |
3451 | ||
3452 | if (btrfs_leaf_free_space(root, leaf) < total_size) { | |
3453 | for (i = nr; i >= 0; i--) { | |
3454 | total_data -= data_size[i]; | |
3455 | total_size -= data_size[i] + sizeof(struct btrfs_item); | |
3456 | if (total_size < btrfs_leaf_free_space(root, leaf)) | |
3457 | break; | |
3458 | } | |
3459 | nr = i; | |
3460 | } | |
3461 | ||
3462 | slot = path->slots[0]; | |
3463 | BUG_ON(slot < 0); | |
3464 | ||
3465 | if (slot != nritems) { | |
3466 | unsigned int old_data = btrfs_item_end_nr(leaf, slot); | |
3467 | ||
3468 | item = btrfs_item_nr(leaf, slot); | |
3469 | btrfs_item_key_to_cpu(leaf, &found_key, slot); | |
3470 | ||
3471 | /* figure out how many keys we can insert in here */ | |
3472 | total_data = data_size[0]; | |
3473 | for (i = 1; i < nr; i++) { | |
5d4f98a2 | 3474 | if (btrfs_comp_cpu_keys(&found_key, cpu_key + i) <= 0) |
f3465ca4 JB |
3475 | break; |
3476 | total_data += data_size[i]; | |
3477 | } | |
3478 | nr = i; | |
3479 | ||
3480 | if (old_data < data_end) { | |
3481 | btrfs_print_leaf(root, leaf); | |
d397712b | 3482 | printk(KERN_CRIT "slot %d old_data %d data_end %d\n", |
f3465ca4 JB |
3483 | slot, old_data, data_end); |
3484 | BUG_ON(1); | |
3485 | } | |
3486 | /* | |
3487 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
3488 | */ | |
3489 | /* first correct the data pointers */ | |
f3465ca4 JB |
3490 | for (i = slot; i < nritems; i++) { |
3491 | u32 ioff; | |
3492 | ||
3493 | item = btrfs_item_nr(leaf, i); | |
f3465ca4 JB |
3494 | ioff = btrfs_item_offset(leaf, item); |
3495 | btrfs_set_item_offset(leaf, item, ioff - total_data); | |
3496 | } | |
f3465ca4 JB |
3497 | /* shift the items */ |
3498 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr), | |
3499 | btrfs_item_nr_offset(slot), | |
3500 | (nritems - slot) * sizeof(struct btrfs_item)); | |
3501 | ||
3502 | /* shift the data */ | |
3503 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + | |
3504 | data_end - total_data, btrfs_leaf_data(leaf) + | |
3505 | data_end, old_data - data_end); | |
3506 | data_end = old_data; | |
3507 | } else { | |
3508 | /* | |
3509 | * this sucks but it has to be done, if we are inserting at | |
3510 | * the end of the leaf only insert 1 of the items, since we | |
3511 | * have no way of knowing whats on the next leaf and we'd have | |
3512 | * to drop our current locks to figure it out | |
3513 | */ | |
3514 | nr = 1; | |
3515 | } | |
3516 | ||
3517 | /* setup the item for the new data */ | |
3518 | for (i = 0; i < nr; i++) { | |
3519 | btrfs_cpu_key_to_disk(&disk_key, cpu_key + i); | |
3520 | btrfs_set_item_key(leaf, &disk_key, slot + i); | |
3521 | item = btrfs_item_nr(leaf, slot + i); | |
3522 | btrfs_set_item_offset(leaf, item, data_end - data_size[i]); | |
3523 | data_end -= data_size[i]; | |
3524 | btrfs_set_item_size(leaf, item, data_size[i]); | |
3525 | } | |
3526 | btrfs_set_header_nritems(leaf, nritems + nr); | |
3527 | btrfs_mark_buffer_dirty(leaf); | |
3528 | ||
3529 | ret = 0; | |
3530 | if (slot == 0) { | |
3531 | btrfs_cpu_key_to_disk(&disk_key, cpu_key); | |
3532 | ret = fixup_low_keys(trans, root, path, &disk_key, 1); | |
3533 | } | |
3534 | ||
3535 | if (btrfs_leaf_free_space(root, leaf) < 0) { | |
3536 | btrfs_print_leaf(root, leaf); | |
3537 | BUG(); | |
3538 | } | |
3539 | out: | |
3540 | if (!ret) | |
3541 | ret = nr; | |
3542 | return ret; | |
3543 | } | |
3544 | ||
74123bd7 | 3545 | /* |
44871b1b CM |
3546 | * this is a helper for btrfs_insert_empty_items, the main goal here is |
3547 | * to save stack depth by doing the bulk of the work in a function | |
3548 | * that doesn't call btrfs_search_slot | |
74123bd7 | 3549 | */ |
16cdcec7 MX |
3550 | int setup_items_for_insert(struct btrfs_trans_handle *trans, |
3551 | struct btrfs_root *root, struct btrfs_path *path, | |
3552 | struct btrfs_key *cpu_key, u32 *data_size, | |
3553 | u32 total_data, u32 total_size, int nr) | |
be0e5c09 | 3554 | { |
5f39d397 | 3555 | struct btrfs_item *item; |
9c58309d | 3556 | int i; |
7518a238 | 3557 | u32 nritems; |
be0e5c09 | 3558 | unsigned int data_end; |
e2fa7227 | 3559 | struct btrfs_disk_key disk_key; |
44871b1b CM |
3560 | int ret; |
3561 | struct extent_buffer *leaf; | |
3562 | int slot; | |
e2fa7227 | 3563 | |
5f39d397 | 3564 | leaf = path->nodes[0]; |
44871b1b | 3565 | slot = path->slots[0]; |
74123bd7 | 3566 | |
5f39d397 | 3567 | nritems = btrfs_header_nritems(leaf); |
123abc88 | 3568 | data_end = leaf_data_end(root, leaf); |
eb60ceac | 3569 | |
f25956cc | 3570 | if (btrfs_leaf_free_space(root, leaf) < total_size) { |
3326d1b0 | 3571 | btrfs_print_leaf(root, leaf); |
d397712b | 3572 | printk(KERN_CRIT "not enough freespace need %u have %d\n", |
9c58309d | 3573 | total_size, btrfs_leaf_free_space(root, leaf)); |
be0e5c09 | 3574 | BUG(); |
d4dbff95 | 3575 | } |
5f39d397 | 3576 | |
be0e5c09 | 3577 | if (slot != nritems) { |
5f39d397 | 3578 | unsigned int old_data = btrfs_item_end_nr(leaf, slot); |
be0e5c09 | 3579 | |
5f39d397 CM |
3580 | if (old_data < data_end) { |
3581 | btrfs_print_leaf(root, leaf); | |
d397712b | 3582 | printk(KERN_CRIT "slot %d old_data %d data_end %d\n", |
5f39d397 CM |
3583 | slot, old_data, data_end); |
3584 | BUG_ON(1); | |
3585 | } | |
be0e5c09 CM |
3586 | /* |
3587 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
3588 | */ | |
3589 | /* first correct the data pointers */ | |
0783fcfc | 3590 | for (i = slot; i < nritems; i++) { |
5f39d397 | 3591 | u32 ioff; |
db94535d | 3592 | |
5f39d397 CM |
3593 | item = btrfs_item_nr(leaf, i); |
3594 | ioff = btrfs_item_offset(leaf, item); | |
9c58309d | 3595 | btrfs_set_item_offset(leaf, item, ioff - total_data); |
0783fcfc | 3596 | } |
be0e5c09 | 3597 | /* shift the items */ |
9c58309d | 3598 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr), |
5f39d397 | 3599 | btrfs_item_nr_offset(slot), |
d6025579 | 3600 | (nritems - slot) * sizeof(struct btrfs_item)); |
be0e5c09 CM |
3601 | |
3602 | /* shift the data */ | |
5f39d397 | 3603 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + |
9c58309d | 3604 | data_end - total_data, btrfs_leaf_data(leaf) + |
d6025579 | 3605 | data_end, old_data - data_end); |
be0e5c09 CM |
3606 | data_end = old_data; |
3607 | } | |
5f39d397 | 3608 | |
62e2749e | 3609 | /* setup the item for the new data */ |
9c58309d CM |
3610 | for (i = 0; i < nr; i++) { |
3611 | btrfs_cpu_key_to_disk(&disk_key, cpu_key + i); | |
3612 | btrfs_set_item_key(leaf, &disk_key, slot + i); | |
3613 | item = btrfs_item_nr(leaf, slot + i); | |
3614 | btrfs_set_item_offset(leaf, item, data_end - data_size[i]); | |
3615 | data_end -= data_size[i]; | |
3616 | btrfs_set_item_size(leaf, item, data_size[i]); | |
3617 | } | |
44871b1b | 3618 | |
9c58309d | 3619 | btrfs_set_header_nritems(leaf, nritems + nr); |
aa5d6bed CM |
3620 | |
3621 | ret = 0; | |
5a01a2e3 CM |
3622 | if (slot == 0) { |
3623 | btrfs_cpu_key_to_disk(&disk_key, cpu_key); | |
e089f05c | 3624 | ret = fixup_low_keys(trans, root, path, &disk_key, 1); |
5a01a2e3 | 3625 | } |
b9473439 CM |
3626 | btrfs_unlock_up_safe(path, 1); |
3627 | btrfs_mark_buffer_dirty(leaf); | |
aa5d6bed | 3628 | |
5f39d397 CM |
3629 | if (btrfs_leaf_free_space(root, leaf) < 0) { |
3630 | btrfs_print_leaf(root, leaf); | |
be0e5c09 | 3631 | BUG(); |
5f39d397 | 3632 | } |
44871b1b CM |
3633 | return ret; |
3634 | } | |
3635 | ||
3636 | /* | |
3637 | * Given a key and some data, insert items into the tree. | |
3638 | * This does all the path init required, making room in the tree if needed. | |
3639 | */ | |
3640 | int btrfs_insert_empty_items(struct btrfs_trans_handle *trans, | |
3641 | struct btrfs_root *root, | |
3642 | struct btrfs_path *path, | |
3643 | struct btrfs_key *cpu_key, u32 *data_size, | |
3644 | int nr) | |
3645 | { | |
44871b1b CM |
3646 | int ret = 0; |
3647 | int slot; | |
3648 | int i; | |
3649 | u32 total_size = 0; | |
3650 | u32 total_data = 0; | |
3651 | ||
3652 | for (i = 0; i < nr; i++) | |
3653 | total_data += data_size[i]; | |
3654 | ||
3655 | total_size = total_data + (nr * sizeof(struct btrfs_item)); | |
3656 | ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1); | |
3657 | if (ret == 0) | |
3658 | return -EEXIST; | |
3659 | if (ret < 0) | |
3660 | goto out; | |
3661 | ||
44871b1b CM |
3662 | slot = path->slots[0]; |
3663 | BUG_ON(slot < 0); | |
3664 | ||
3665 | ret = setup_items_for_insert(trans, root, path, cpu_key, data_size, | |
3666 | total_data, total_size, nr); | |
3667 | ||
ed2ff2cb | 3668 | out: |
62e2749e CM |
3669 | return ret; |
3670 | } | |
3671 | ||
3672 | /* | |
3673 | * Given a key and some data, insert an item into the tree. | |
3674 | * This does all the path init required, making room in the tree if needed. | |
3675 | */ | |
e089f05c CM |
3676 | int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root |
3677 | *root, struct btrfs_key *cpu_key, void *data, u32 | |
3678 | data_size) | |
62e2749e CM |
3679 | { |
3680 | int ret = 0; | |
2c90e5d6 | 3681 | struct btrfs_path *path; |
5f39d397 CM |
3682 | struct extent_buffer *leaf; |
3683 | unsigned long ptr; | |
62e2749e | 3684 | |
2c90e5d6 | 3685 | path = btrfs_alloc_path(); |
db5b493a TI |
3686 | if (!path) |
3687 | return -ENOMEM; | |
2c90e5d6 | 3688 | ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size); |
62e2749e | 3689 | if (!ret) { |
5f39d397 CM |
3690 | leaf = path->nodes[0]; |
3691 | ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); | |
3692 | write_extent_buffer(leaf, data, ptr, data_size); | |
3693 | btrfs_mark_buffer_dirty(leaf); | |
62e2749e | 3694 | } |
2c90e5d6 | 3695 | btrfs_free_path(path); |
aa5d6bed | 3696 | return ret; |
be0e5c09 CM |
3697 | } |
3698 | ||
74123bd7 | 3699 | /* |
5de08d7d | 3700 | * delete the pointer from a given node. |
74123bd7 | 3701 | * |
d352ac68 CM |
3702 | * the tree should have been previously balanced so the deletion does not |
3703 | * empty a node. | |
74123bd7 | 3704 | */ |
e089f05c CM |
3705 | static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
3706 | struct btrfs_path *path, int level, int slot) | |
be0e5c09 | 3707 | { |
5f39d397 | 3708 | struct extent_buffer *parent = path->nodes[level]; |
7518a238 | 3709 | u32 nritems; |
aa5d6bed | 3710 | int ret = 0; |
bb803951 | 3711 | int wret; |
be0e5c09 | 3712 | |
5f39d397 | 3713 | nritems = btrfs_header_nritems(parent); |
d397712b | 3714 | if (slot != nritems - 1) { |
5f39d397 CM |
3715 | memmove_extent_buffer(parent, |
3716 | btrfs_node_key_ptr_offset(slot), | |
3717 | btrfs_node_key_ptr_offset(slot + 1), | |
d6025579 CM |
3718 | sizeof(struct btrfs_key_ptr) * |
3719 | (nritems - slot - 1)); | |
bb803951 | 3720 | } |
7518a238 | 3721 | nritems--; |
5f39d397 | 3722 | btrfs_set_header_nritems(parent, nritems); |
7518a238 | 3723 | if (nritems == 0 && parent == root->node) { |
5f39d397 | 3724 | BUG_ON(btrfs_header_level(root->node) != 1); |
bb803951 | 3725 | /* just turn the root into a leaf and break */ |
5f39d397 | 3726 | btrfs_set_header_level(root->node, 0); |
bb803951 | 3727 | } else if (slot == 0) { |
5f39d397 CM |
3728 | struct btrfs_disk_key disk_key; |
3729 | ||
3730 | btrfs_node_key(parent, &disk_key, 0); | |
3731 | wret = fixup_low_keys(trans, root, path, &disk_key, level + 1); | |
0f70abe2 CM |
3732 | if (wret) |
3733 | ret = wret; | |
be0e5c09 | 3734 | } |
d6025579 | 3735 | btrfs_mark_buffer_dirty(parent); |
aa5d6bed | 3736 | return ret; |
be0e5c09 CM |
3737 | } |
3738 | ||
323ac95b CM |
3739 | /* |
3740 | * a helper function to delete the leaf pointed to by path->slots[1] and | |
5d4f98a2 | 3741 | * path->nodes[1]. |
323ac95b CM |
3742 | * |
3743 | * This deletes the pointer in path->nodes[1] and frees the leaf | |
3744 | * block extent. zero is returned if it all worked out, < 0 otherwise. | |
3745 | * | |
3746 | * The path must have already been setup for deleting the leaf, including | |
3747 | * all the proper balancing. path->nodes[1] must be locked. | |
3748 | */ | |
5d4f98a2 YZ |
3749 | static noinline int btrfs_del_leaf(struct btrfs_trans_handle *trans, |
3750 | struct btrfs_root *root, | |
3751 | struct btrfs_path *path, | |
3752 | struct extent_buffer *leaf) | |
323ac95b CM |
3753 | { |
3754 | int ret; | |
323ac95b | 3755 | |
5d4f98a2 | 3756 | WARN_ON(btrfs_header_generation(leaf) != trans->transid); |
323ac95b CM |
3757 | ret = del_ptr(trans, root, path, 1, path->slots[1]); |
3758 | if (ret) | |
3759 | return ret; | |
3760 | ||
4d081c41 CM |
3761 | /* |
3762 | * btrfs_free_extent is expensive, we want to make sure we | |
3763 | * aren't holding any locks when we call it | |
3764 | */ | |
3765 | btrfs_unlock_up_safe(path, 0); | |
3766 | ||
f0486c68 YZ |
3767 | root_sub_used(root, leaf->len); |
3768 | ||
3769 | btrfs_free_tree_block(trans, root, leaf, 0, 1); | |
3770 | return 0; | |
323ac95b | 3771 | } |
74123bd7 CM |
3772 | /* |
3773 | * delete the item at the leaf level in path. If that empties | |
3774 | * the leaf, remove it from the tree | |
3775 | */ | |
85e21bac CM |
3776 | int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
3777 | struct btrfs_path *path, int slot, int nr) | |
be0e5c09 | 3778 | { |
5f39d397 CM |
3779 | struct extent_buffer *leaf; |
3780 | struct btrfs_item *item; | |
85e21bac CM |
3781 | int last_off; |
3782 | int dsize = 0; | |
aa5d6bed CM |
3783 | int ret = 0; |
3784 | int wret; | |
85e21bac | 3785 | int i; |
7518a238 | 3786 | u32 nritems; |
be0e5c09 | 3787 | |
5f39d397 | 3788 | leaf = path->nodes[0]; |
85e21bac CM |
3789 | last_off = btrfs_item_offset_nr(leaf, slot + nr - 1); |
3790 | ||
3791 | for (i = 0; i < nr; i++) | |
3792 | dsize += btrfs_item_size_nr(leaf, slot + i); | |
3793 | ||
5f39d397 | 3794 | nritems = btrfs_header_nritems(leaf); |
be0e5c09 | 3795 | |
85e21bac | 3796 | if (slot + nr != nritems) { |
123abc88 | 3797 | int data_end = leaf_data_end(root, leaf); |
5f39d397 CM |
3798 | |
3799 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + | |
d6025579 CM |
3800 | data_end + dsize, |
3801 | btrfs_leaf_data(leaf) + data_end, | |
85e21bac | 3802 | last_off - data_end); |
5f39d397 | 3803 | |
85e21bac | 3804 | for (i = slot + nr; i < nritems; i++) { |
5f39d397 | 3805 | u32 ioff; |
db94535d | 3806 | |
5f39d397 CM |
3807 | item = btrfs_item_nr(leaf, i); |
3808 | ioff = btrfs_item_offset(leaf, item); | |
3809 | btrfs_set_item_offset(leaf, item, ioff + dsize); | |
0783fcfc | 3810 | } |
db94535d | 3811 | |
5f39d397 | 3812 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot), |
85e21bac | 3813 | btrfs_item_nr_offset(slot + nr), |
d6025579 | 3814 | sizeof(struct btrfs_item) * |
85e21bac | 3815 | (nritems - slot - nr)); |
be0e5c09 | 3816 | } |
85e21bac CM |
3817 | btrfs_set_header_nritems(leaf, nritems - nr); |
3818 | nritems -= nr; | |
5f39d397 | 3819 | |
74123bd7 | 3820 | /* delete the leaf if we've emptied it */ |
7518a238 | 3821 | if (nritems == 0) { |
5f39d397 CM |
3822 | if (leaf == root->node) { |
3823 | btrfs_set_header_level(leaf, 0); | |
9a8dd150 | 3824 | } else { |
f0486c68 YZ |
3825 | btrfs_set_path_blocking(path); |
3826 | clean_tree_block(trans, root, leaf); | |
5d4f98a2 | 3827 | ret = btrfs_del_leaf(trans, root, path, leaf); |
323ac95b | 3828 | BUG_ON(ret); |
9a8dd150 | 3829 | } |
be0e5c09 | 3830 | } else { |
7518a238 | 3831 | int used = leaf_space_used(leaf, 0, nritems); |
aa5d6bed | 3832 | if (slot == 0) { |
5f39d397 CM |
3833 | struct btrfs_disk_key disk_key; |
3834 | ||
3835 | btrfs_item_key(leaf, &disk_key, 0); | |
e089f05c | 3836 | wret = fixup_low_keys(trans, root, path, |
5f39d397 | 3837 | &disk_key, 1); |
aa5d6bed CM |
3838 | if (wret) |
3839 | ret = wret; | |
3840 | } | |
aa5d6bed | 3841 | |
74123bd7 | 3842 | /* delete the leaf if it is mostly empty */ |
d717aa1d | 3843 | if (used < BTRFS_LEAF_DATA_SIZE(root) / 3) { |
be0e5c09 CM |
3844 | /* push_leaf_left fixes the path. |
3845 | * make sure the path still points to our leaf | |
3846 | * for possible call to del_ptr below | |
3847 | */ | |
4920c9ac | 3848 | slot = path->slots[1]; |
5f39d397 CM |
3849 | extent_buffer_get(leaf); |
3850 | ||
b9473439 | 3851 | btrfs_set_path_blocking(path); |
99d8f83c CM |
3852 | wret = push_leaf_left(trans, root, path, 1, 1, |
3853 | 1, (u32)-1); | |
54aa1f4d | 3854 | if (wret < 0 && wret != -ENOSPC) |
aa5d6bed | 3855 | ret = wret; |
5f39d397 CM |
3856 | |
3857 | if (path->nodes[0] == leaf && | |
3858 | btrfs_header_nritems(leaf)) { | |
99d8f83c CM |
3859 | wret = push_leaf_right(trans, root, path, 1, |
3860 | 1, 1, 0); | |
54aa1f4d | 3861 | if (wret < 0 && wret != -ENOSPC) |
aa5d6bed CM |
3862 | ret = wret; |
3863 | } | |
5f39d397 CM |
3864 | |
3865 | if (btrfs_header_nritems(leaf) == 0) { | |
323ac95b | 3866 | path->slots[1] = slot; |
5d4f98a2 | 3867 | ret = btrfs_del_leaf(trans, root, path, leaf); |
323ac95b | 3868 | BUG_ON(ret); |
5f39d397 | 3869 | free_extent_buffer(leaf); |
5de08d7d | 3870 | } else { |
925baedd CM |
3871 | /* if we're still in the path, make sure |
3872 | * we're dirty. Otherwise, one of the | |
3873 | * push_leaf functions must have already | |
3874 | * dirtied this buffer | |
3875 | */ | |
3876 | if (path->nodes[0] == leaf) | |
3877 | btrfs_mark_buffer_dirty(leaf); | |
5f39d397 | 3878 | free_extent_buffer(leaf); |
be0e5c09 | 3879 | } |
d5719762 | 3880 | } else { |
5f39d397 | 3881 | btrfs_mark_buffer_dirty(leaf); |
be0e5c09 CM |
3882 | } |
3883 | } | |
aa5d6bed | 3884 | return ret; |
be0e5c09 CM |
3885 | } |
3886 | ||
7bb86316 | 3887 | /* |
925baedd | 3888 | * search the tree again to find a leaf with lesser keys |
7bb86316 CM |
3889 | * returns 0 if it found something or 1 if there are no lesser leaves. |
3890 | * returns < 0 on io errors. | |
d352ac68 CM |
3891 | * |
3892 | * This may release the path, and so you may lose any locks held at the | |
3893 | * time you call it. | |
7bb86316 CM |
3894 | */ |
3895 | int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path) | |
3896 | { | |
925baedd CM |
3897 | struct btrfs_key key; |
3898 | struct btrfs_disk_key found_key; | |
3899 | int ret; | |
7bb86316 | 3900 | |
925baedd | 3901 | btrfs_item_key_to_cpu(path->nodes[0], &key, 0); |
7bb86316 | 3902 | |
925baedd CM |
3903 | if (key.offset > 0) |
3904 | key.offset--; | |
3905 | else if (key.type > 0) | |
3906 | key.type--; | |
3907 | else if (key.objectid > 0) | |
3908 | key.objectid--; | |
3909 | else | |
3910 | return 1; | |
7bb86316 | 3911 | |
b3b4aa74 | 3912 | btrfs_release_path(path); |
925baedd CM |
3913 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
3914 | if (ret < 0) | |
3915 | return ret; | |
3916 | btrfs_item_key(path->nodes[0], &found_key, 0); | |
3917 | ret = comp_keys(&found_key, &key); | |
3918 | if (ret < 0) | |
3919 | return 0; | |
3920 | return 1; | |
7bb86316 CM |
3921 | } |
3922 | ||
3f157a2f CM |
3923 | /* |
3924 | * A helper function to walk down the tree starting at min_key, and looking | |
3925 | * for nodes or leaves that are either in cache or have a minimum | |
d352ac68 | 3926 | * transaction id. This is used by the btree defrag code, and tree logging |
3f157a2f CM |
3927 | * |
3928 | * This does not cow, but it does stuff the starting key it finds back | |
3929 | * into min_key, so you can call btrfs_search_slot with cow=1 on the | |
3930 | * key and get a writable path. | |
3931 | * | |
3932 | * This does lock as it descends, and path->keep_locks should be set | |
3933 | * to 1 by the caller. | |
3934 | * | |
3935 | * This honors path->lowest_level to prevent descent past a given level | |
3936 | * of the tree. | |
3937 | * | |
d352ac68 CM |
3938 | * min_trans indicates the oldest transaction that you are interested |
3939 | * in walking through. Any nodes or leaves older than min_trans are | |
3940 | * skipped over (without reading them). | |
3941 | * | |
3f157a2f CM |
3942 | * returns zero if something useful was found, < 0 on error and 1 if there |
3943 | * was nothing in the tree that matched the search criteria. | |
3944 | */ | |
3945 | int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key, | |
e02119d5 | 3946 | struct btrfs_key *max_key, |
3f157a2f CM |
3947 | struct btrfs_path *path, int cache_only, |
3948 | u64 min_trans) | |
3949 | { | |
3950 | struct extent_buffer *cur; | |
3951 | struct btrfs_key found_key; | |
3952 | int slot; | |
9652480b | 3953 | int sret; |
3f157a2f CM |
3954 | u32 nritems; |
3955 | int level; | |
3956 | int ret = 1; | |
3957 | ||
934d375b | 3958 | WARN_ON(!path->keep_locks); |
3f157a2f | 3959 | again: |
bd681513 | 3960 | cur = btrfs_read_lock_root_node(root); |
3f157a2f | 3961 | level = btrfs_header_level(cur); |
e02119d5 | 3962 | WARN_ON(path->nodes[level]); |
3f157a2f | 3963 | path->nodes[level] = cur; |
bd681513 | 3964 | path->locks[level] = BTRFS_READ_LOCK; |
3f157a2f CM |
3965 | |
3966 | if (btrfs_header_generation(cur) < min_trans) { | |
3967 | ret = 1; | |
3968 | goto out; | |
3969 | } | |
d397712b | 3970 | while (1) { |
3f157a2f CM |
3971 | nritems = btrfs_header_nritems(cur); |
3972 | level = btrfs_header_level(cur); | |
9652480b | 3973 | sret = bin_search(cur, min_key, level, &slot); |
3f157a2f | 3974 | |
323ac95b CM |
3975 | /* at the lowest level, we're done, setup the path and exit */ |
3976 | if (level == path->lowest_level) { | |
e02119d5 CM |
3977 | if (slot >= nritems) |
3978 | goto find_next_key; | |
3f157a2f CM |
3979 | ret = 0; |
3980 | path->slots[level] = slot; | |
3981 | btrfs_item_key_to_cpu(cur, &found_key, slot); | |
3982 | goto out; | |
3983 | } | |
9652480b Y |
3984 | if (sret && slot > 0) |
3985 | slot--; | |
3f157a2f CM |
3986 | /* |
3987 | * check this node pointer against the cache_only and | |
3988 | * min_trans parameters. If it isn't in cache or is too | |
3989 | * old, skip to the next one. | |
3990 | */ | |
d397712b | 3991 | while (slot < nritems) { |
3f157a2f CM |
3992 | u64 blockptr; |
3993 | u64 gen; | |
3994 | struct extent_buffer *tmp; | |
e02119d5 CM |
3995 | struct btrfs_disk_key disk_key; |
3996 | ||
3f157a2f CM |
3997 | blockptr = btrfs_node_blockptr(cur, slot); |
3998 | gen = btrfs_node_ptr_generation(cur, slot); | |
3999 | if (gen < min_trans) { | |
4000 | slot++; | |
4001 | continue; | |
4002 | } | |
4003 | if (!cache_only) | |
4004 | break; | |
4005 | ||
e02119d5 CM |
4006 | if (max_key) { |
4007 | btrfs_node_key(cur, &disk_key, slot); | |
4008 | if (comp_keys(&disk_key, max_key) >= 0) { | |
4009 | ret = 1; | |
4010 | goto out; | |
4011 | } | |
4012 | } | |
4013 | ||
3f157a2f CM |
4014 | tmp = btrfs_find_tree_block(root, blockptr, |
4015 | btrfs_level_size(root, level - 1)); | |
4016 | ||
4017 | if (tmp && btrfs_buffer_uptodate(tmp, gen)) { | |
4018 | free_extent_buffer(tmp); | |
4019 | break; | |
4020 | } | |
4021 | if (tmp) | |
4022 | free_extent_buffer(tmp); | |
4023 | slot++; | |
4024 | } | |
e02119d5 | 4025 | find_next_key: |
3f157a2f CM |
4026 | /* |
4027 | * we didn't find a candidate key in this node, walk forward | |
4028 | * and find another one | |
4029 | */ | |
4030 | if (slot >= nritems) { | |
e02119d5 | 4031 | path->slots[level] = slot; |
b4ce94de | 4032 | btrfs_set_path_blocking(path); |
e02119d5 | 4033 | sret = btrfs_find_next_key(root, path, min_key, level, |
3f157a2f | 4034 | cache_only, min_trans); |
e02119d5 | 4035 | if (sret == 0) { |
b3b4aa74 | 4036 | btrfs_release_path(path); |
3f157a2f CM |
4037 | goto again; |
4038 | } else { | |
4039 | goto out; | |
4040 | } | |
4041 | } | |
4042 | /* save our key for returning back */ | |
4043 | btrfs_node_key_to_cpu(cur, &found_key, slot); | |
4044 | path->slots[level] = slot; | |
4045 | if (level == path->lowest_level) { | |
4046 | ret = 0; | |
4047 | unlock_up(path, level, 1); | |
4048 | goto out; | |
4049 | } | |
b4ce94de | 4050 | btrfs_set_path_blocking(path); |
3f157a2f | 4051 | cur = read_node_slot(root, cur, slot); |
97d9a8a4 | 4052 | BUG_ON(!cur); |
3f157a2f | 4053 | |
bd681513 | 4054 | btrfs_tree_read_lock(cur); |
b4ce94de | 4055 | |
bd681513 | 4056 | path->locks[level - 1] = BTRFS_READ_LOCK; |
3f157a2f CM |
4057 | path->nodes[level - 1] = cur; |
4058 | unlock_up(path, level, 1); | |
bd681513 | 4059 | btrfs_clear_path_blocking(path, NULL, 0); |
3f157a2f CM |
4060 | } |
4061 | out: | |
4062 | if (ret == 0) | |
4063 | memcpy(min_key, &found_key, sizeof(found_key)); | |
b4ce94de | 4064 | btrfs_set_path_blocking(path); |
3f157a2f CM |
4065 | return ret; |
4066 | } | |
4067 | ||
4068 | /* | |
4069 | * this is similar to btrfs_next_leaf, but does not try to preserve | |
4070 | * and fixup the path. It looks for and returns the next key in the | |
4071 | * tree based on the current path and the cache_only and min_trans | |
4072 | * parameters. | |
4073 | * | |
4074 | * 0 is returned if another key is found, < 0 if there are any errors | |
4075 | * and 1 is returned if there are no higher keys in the tree | |
4076 | * | |
4077 | * path->keep_locks should be set to 1 on the search made before | |
4078 | * calling this function. | |
4079 | */ | |
e7a84565 | 4080 | int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path, |
33c66f43 | 4081 | struct btrfs_key *key, int level, |
3f157a2f | 4082 | int cache_only, u64 min_trans) |
e7a84565 | 4083 | { |
e7a84565 CM |
4084 | int slot; |
4085 | struct extent_buffer *c; | |
4086 | ||
934d375b | 4087 | WARN_ON(!path->keep_locks); |
d397712b | 4088 | while (level < BTRFS_MAX_LEVEL) { |
e7a84565 CM |
4089 | if (!path->nodes[level]) |
4090 | return 1; | |
4091 | ||
4092 | slot = path->slots[level] + 1; | |
4093 | c = path->nodes[level]; | |
3f157a2f | 4094 | next: |
e7a84565 | 4095 | if (slot >= btrfs_header_nritems(c)) { |
33c66f43 YZ |
4096 | int ret; |
4097 | int orig_lowest; | |
4098 | struct btrfs_key cur_key; | |
4099 | if (level + 1 >= BTRFS_MAX_LEVEL || | |
4100 | !path->nodes[level + 1]) | |
e7a84565 | 4101 | return 1; |
33c66f43 YZ |
4102 | |
4103 | if (path->locks[level + 1]) { | |
4104 | level++; | |
4105 | continue; | |
4106 | } | |
4107 | ||
4108 | slot = btrfs_header_nritems(c) - 1; | |
4109 | if (level == 0) | |
4110 | btrfs_item_key_to_cpu(c, &cur_key, slot); | |
4111 | else | |
4112 | btrfs_node_key_to_cpu(c, &cur_key, slot); | |
4113 | ||
4114 | orig_lowest = path->lowest_level; | |
b3b4aa74 | 4115 | btrfs_release_path(path); |
33c66f43 YZ |
4116 | path->lowest_level = level; |
4117 | ret = btrfs_search_slot(NULL, root, &cur_key, path, | |
4118 | 0, 0); | |
4119 | path->lowest_level = orig_lowest; | |
4120 | if (ret < 0) | |
4121 | return ret; | |
4122 | ||
4123 | c = path->nodes[level]; | |
4124 | slot = path->slots[level]; | |
4125 | if (ret == 0) | |
4126 | slot++; | |
4127 | goto next; | |
e7a84565 | 4128 | } |
33c66f43 | 4129 | |
e7a84565 CM |
4130 | if (level == 0) |
4131 | btrfs_item_key_to_cpu(c, key, slot); | |
3f157a2f CM |
4132 | else { |
4133 | u64 blockptr = btrfs_node_blockptr(c, slot); | |
4134 | u64 gen = btrfs_node_ptr_generation(c, slot); | |
4135 | ||
4136 | if (cache_only) { | |
4137 | struct extent_buffer *cur; | |
4138 | cur = btrfs_find_tree_block(root, blockptr, | |
4139 | btrfs_level_size(root, level - 1)); | |
4140 | if (!cur || !btrfs_buffer_uptodate(cur, gen)) { | |
4141 | slot++; | |
4142 | if (cur) | |
4143 | free_extent_buffer(cur); | |
4144 | goto next; | |
4145 | } | |
4146 | free_extent_buffer(cur); | |
4147 | } | |
4148 | if (gen < min_trans) { | |
4149 | slot++; | |
4150 | goto next; | |
4151 | } | |
e7a84565 | 4152 | btrfs_node_key_to_cpu(c, key, slot); |
3f157a2f | 4153 | } |
e7a84565 CM |
4154 | return 0; |
4155 | } | |
4156 | return 1; | |
4157 | } | |
4158 | ||
97571fd0 | 4159 | /* |
925baedd | 4160 | * search the tree again to find a leaf with greater keys |
0f70abe2 CM |
4161 | * returns 0 if it found something or 1 if there are no greater leaves. |
4162 | * returns < 0 on io errors. | |
97571fd0 | 4163 | */ |
234b63a0 | 4164 | int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path) |
d97e63b6 CM |
4165 | { |
4166 | int slot; | |
8e73f275 | 4167 | int level; |
5f39d397 | 4168 | struct extent_buffer *c; |
8e73f275 | 4169 | struct extent_buffer *next; |
925baedd CM |
4170 | struct btrfs_key key; |
4171 | u32 nritems; | |
4172 | int ret; | |
8e73f275 | 4173 | int old_spinning = path->leave_spinning; |
bd681513 | 4174 | int next_rw_lock = 0; |
925baedd CM |
4175 | |
4176 | nritems = btrfs_header_nritems(path->nodes[0]); | |
d397712b | 4177 | if (nritems == 0) |
925baedd | 4178 | return 1; |
925baedd | 4179 | |
8e73f275 CM |
4180 | btrfs_item_key_to_cpu(path->nodes[0], &key, nritems - 1); |
4181 | again: | |
4182 | level = 1; | |
4183 | next = NULL; | |
bd681513 | 4184 | next_rw_lock = 0; |
b3b4aa74 | 4185 | btrfs_release_path(path); |
8e73f275 | 4186 | |
a2135011 | 4187 | path->keep_locks = 1; |
31533fb2 | 4188 | path->leave_spinning = 1; |
8e73f275 | 4189 | |
925baedd CM |
4190 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
4191 | path->keep_locks = 0; | |
4192 | ||
4193 | if (ret < 0) | |
4194 | return ret; | |
4195 | ||
a2135011 | 4196 | nritems = btrfs_header_nritems(path->nodes[0]); |
168fd7d2 CM |
4197 | /* |
4198 | * by releasing the path above we dropped all our locks. A balance | |
4199 | * could have added more items next to the key that used to be | |
4200 | * at the very end of the block. So, check again here and | |
4201 | * advance the path if there are now more items available. | |
4202 | */ | |
a2135011 | 4203 | if (nritems > 0 && path->slots[0] < nritems - 1) { |
e457afec YZ |
4204 | if (ret == 0) |
4205 | path->slots[0]++; | |
8e73f275 | 4206 | ret = 0; |
925baedd CM |
4207 | goto done; |
4208 | } | |
d97e63b6 | 4209 | |
d397712b | 4210 | while (level < BTRFS_MAX_LEVEL) { |
8e73f275 CM |
4211 | if (!path->nodes[level]) { |
4212 | ret = 1; | |
4213 | goto done; | |
4214 | } | |
5f39d397 | 4215 | |
d97e63b6 CM |
4216 | slot = path->slots[level] + 1; |
4217 | c = path->nodes[level]; | |
5f39d397 | 4218 | if (slot >= btrfs_header_nritems(c)) { |
d97e63b6 | 4219 | level++; |
8e73f275 CM |
4220 | if (level == BTRFS_MAX_LEVEL) { |
4221 | ret = 1; | |
4222 | goto done; | |
4223 | } | |
d97e63b6 CM |
4224 | continue; |
4225 | } | |
5f39d397 | 4226 | |
925baedd | 4227 | if (next) { |
bd681513 | 4228 | btrfs_tree_unlock_rw(next, next_rw_lock); |
5f39d397 | 4229 | free_extent_buffer(next); |
925baedd | 4230 | } |
5f39d397 | 4231 | |
8e73f275 | 4232 | next = c; |
bd681513 | 4233 | next_rw_lock = path->locks[level]; |
8e73f275 CM |
4234 | ret = read_block_for_search(NULL, root, path, &next, level, |
4235 | slot, &key); | |
4236 | if (ret == -EAGAIN) | |
4237 | goto again; | |
5f39d397 | 4238 | |
76a05b35 | 4239 | if (ret < 0) { |
b3b4aa74 | 4240 | btrfs_release_path(path); |
76a05b35 CM |
4241 | goto done; |
4242 | } | |
4243 | ||
5cd57b2c | 4244 | if (!path->skip_locking) { |
bd681513 | 4245 | ret = btrfs_try_tree_read_lock(next); |
8e73f275 CM |
4246 | if (!ret) { |
4247 | btrfs_set_path_blocking(path); | |
bd681513 | 4248 | btrfs_tree_read_lock(next); |
31533fb2 | 4249 | btrfs_clear_path_blocking(path, next, |
bd681513 | 4250 | BTRFS_READ_LOCK); |
8e73f275 | 4251 | } |
31533fb2 | 4252 | next_rw_lock = BTRFS_READ_LOCK; |
5cd57b2c | 4253 | } |
d97e63b6 CM |
4254 | break; |
4255 | } | |
4256 | path->slots[level] = slot; | |
d397712b | 4257 | while (1) { |
d97e63b6 CM |
4258 | level--; |
4259 | c = path->nodes[level]; | |
925baedd | 4260 | if (path->locks[level]) |
bd681513 | 4261 | btrfs_tree_unlock_rw(c, path->locks[level]); |
8e73f275 | 4262 | |
5f39d397 | 4263 | free_extent_buffer(c); |
d97e63b6 CM |
4264 | path->nodes[level] = next; |
4265 | path->slots[level] = 0; | |
a74a4b97 | 4266 | if (!path->skip_locking) |
bd681513 | 4267 | path->locks[level] = next_rw_lock; |
d97e63b6 CM |
4268 | if (!level) |
4269 | break; | |
b4ce94de | 4270 | |
8e73f275 CM |
4271 | ret = read_block_for_search(NULL, root, path, &next, level, |
4272 | 0, &key); | |
4273 | if (ret == -EAGAIN) | |
4274 | goto again; | |
4275 | ||
76a05b35 | 4276 | if (ret < 0) { |
b3b4aa74 | 4277 | btrfs_release_path(path); |
76a05b35 CM |
4278 | goto done; |
4279 | } | |
4280 | ||
5cd57b2c | 4281 | if (!path->skip_locking) { |
bd681513 | 4282 | ret = btrfs_try_tree_read_lock(next); |
8e73f275 CM |
4283 | if (!ret) { |
4284 | btrfs_set_path_blocking(path); | |
bd681513 | 4285 | btrfs_tree_read_lock(next); |
31533fb2 | 4286 | btrfs_clear_path_blocking(path, next, |
bd681513 CM |
4287 | BTRFS_READ_LOCK); |
4288 | } | |
31533fb2 | 4289 | next_rw_lock = BTRFS_READ_LOCK; |
5cd57b2c | 4290 | } |
d97e63b6 | 4291 | } |
8e73f275 | 4292 | ret = 0; |
925baedd CM |
4293 | done: |
4294 | unlock_up(path, 0, 1); | |
8e73f275 CM |
4295 | path->leave_spinning = old_spinning; |
4296 | if (!old_spinning) | |
4297 | btrfs_set_path_blocking(path); | |
4298 | ||
4299 | return ret; | |
d97e63b6 | 4300 | } |
0b86a832 | 4301 | |
3f157a2f CM |
4302 | /* |
4303 | * this uses btrfs_prev_leaf to walk backwards in the tree, and keeps | |
4304 | * searching until it gets past min_objectid or finds an item of 'type' | |
4305 | * | |
4306 | * returns 0 if something is found, 1 if nothing was found and < 0 on error | |
4307 | */ | |
0b86a832 CM |
4308 | int btrfs_previous_item(struct btrfs_root *root, |
4309 | struct btrfs_path *path, u64 min_objectid, | |
4310 | int type) | |
4311 | { | |
4312 | struct btrfs_key found_key; | |
4313 | struct extent_buffer *leaf; | |
e02119d5 | 4314 | u32 nritems; |
0b86a832 CM |
4315 | int ret; |
4316 | ||
d397712b | 4317 | while (1) { |
0b86a832 | 4318 | if (path->slots[0] == 0) { |
b4ce94de | 4319 | btrfs_set_path_blocking(path); |
0b86a832 CM |
4320 | ret = btrfs_prev_leaf(root, path); |
4321 | if (ret != 0) | |
4322 | return ret; | |
4323 | } else { | |
4324 | path->slots[0]--; | |
4325 | } | |
4326 | leaf = path->nodes[0]; | |
e02119d5 CM |
4327 | nritems = btrfs_header_nritems(leaf); |
4328 | if (nritems == 0) | |
4329 | return 1; | |
4330 | if (path->slots[0] == nritems) | |
4331 | path->slots[0]--; | |
4332 | ||
0b86a832 | 4333 | btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); |
e02119d5 CM |
4334 | if (found_key.objectid < min_objectid) |
4335 | break; | |
0a4eefbb YZ |
4336 | if (found_key.type == type) |
4337 | return 0; | |
e02119d5 CM |
4338 | if (found_key.objectid == min_objectid && |
4339 | found_key.type < type) | |
4340 | break; | |
0b86a832 CM |
4341 | } |
4342 | return 1; | |
4343 | } |