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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++) { | |
57 | if (p->nodes[i] && p->locks[i]) | |
58 | btrfs_set_lock_blocking(p->nodes[i]); | |
59 | } | |
60 | } | |
61 | ||
62 | /* | |
63 | * reset all the locked nodes in the patch to spinning locks. | |
4008c04a CM |
64 | * |
65 | * held is used to keep lockdep happy, when lockdep is enabled | |
66 | * we set held to a blocking lock before we go around and | |
67 | * retake all the spinlocks in the path. You can safely use NULL | |
68 | * for held | |
b4ce94de | 69 | */ |
4008c04a CM |
70 | noinline void btrfs_clear_path_blocking(struct btrfs_path *p, |
71 | struct extent_buffer *held) | |
b4ce94de CM |
72 | { |
73 | int i; | |
4008c04a CM |
74 | |
75 | #ifdef CONFIG_DEBUG_LOCK_ALLOC | |
76 | /* lockdep really cares that we take all of these spinlocks | |
77 | * in the right order. If any of the locks in the path are not | |
78 | * currently blocking, it is going to complain. So, make really | |
79 | * really sure by forcing the path to blocking before we clear | |
80 | * the path blocking. | |
81 | */ | |
82 | if (held) | |
83 | btrfs_set_lock_blocking(held); | |
84 | btrfs_set_path_blocking(p); | |
85 | #endif | |
86 | ||
87 | for (i = BTRFS_MAX_LEVEL - 1; i >= 0; i--) { | |
b4ce94de CM |
88 | if (p->nodes[i] && p->locks[i]) |
89 | btrfs_clear_lock_blocking(p->nodes[i]); | |
90 | } | |
4008c04a CM |
91 | |
92 | #ifdef CONFIG_DEBUG_LOCK_ALLOC | |
93 | if (held) | |
94 | btrfs_clear_lock_blocking(held); | |
95 | #endif | |
b4ce94de CM |
96 | } |
97 | ||
d352ac68 | 98 | /* this also releases the path */ |
df24a2b9 | 99 | void btrfs_free_path(struct btrfs_path *p) |
be0e5c09 | 100 | { |
ff175d57 JJ |
101 | if (!p) |
102 | return; | |
b3b4aa74 | 103 | btrfs_release_path(p); |
df24a2b9 | 104 | kmem_cache_free(btrfs_path_cachep, p); |
be0e5c09 CM |
105 | } |
106 | ||
d352ac68 CM |
107 | /* |
108 | * path release drops references on the extent buffers in the path | |
109 | * and it drops any locks held by this path | |
110 | * | |
111 | * It is safe to call this on paths that no locks or extent buffers held. | |
112 | */ | |
b3b4aa74 | 113 | noinline void btrfs_release_path(struct btrfs_path *p) |
eb60ceac CM |
114 | { |
115 | int i; | |
a2135011 | 116 | |
234b63a0 | 117 | for (i = 0; i < BTRFS_MAX_LEVEL; i++) { |
3f157a2f | 118 | p->slots[i] = 0; |
eb60ceac | 119 | if (!p->nodes[i]) |
925baedd CM |
120 | continue; |
121 | if (p->locks[i]) { | |
122 | btrfs_tree_unlock(p->nodes[i]); | |
123 | p->locks[i] = 0; | |
124 | } | |
5f39d397 | 125 | free_extent_buffer(p->nodes[i]); |
3f157a2f | 126 | p->nodes[i] = NULL; |
eb60ceac CM |
127 | } |
128 | } | |
129 | ||
d352ac68 CM |
130 | /* |
131 | * safely gets a reference on the root node of a tree. A lock | |
132 | * is not taken, so a concurrent writer may put a different node | |
133 | * at the root of the tree. See btrfs_lock_root_node for the | |
134 | * looping required. | |
135 | * | |
136 | * The extent buffer returned by this has a reference taken, so | |
137 | * it won't disappear. It may stop being the root of the tree | |
138 | * at any time because there are no locks held. | |
139 | */ | |
925baedd CM |
140 | struct extent_buffer *btrfs_root_node(struct btrfs_root *root) |
141 | { | |
142 | struct extent_buffer *eb; | |
240f62c8 CM |
143 | |
144 | rcu_read_lock(); | |
145 | eb = rcu_dereference(root->node); | |
925baedd | 146 | extent_buffer_get(eb); |
240f62c8 | 147 | rcu_read_unlock(); |
925baedd CM |
148 | return eb; |
149 | } | |
150 | ||
d352ac68 CM |
151 | /* loop around taking references on and locking the root node of the |
152 | * tree until you end up with a lock on the root. A locked buffer | |
153 | * is returned, with a reference held. | |
154 | */ | |
925baedd CM |
155 | struct extent_buffer *btrfs_lock_root_node(struct btrfs_root *root) |
156 | { | |
157 | struct extent_buffer *eb; | |
158 | ||
d397712b | 159 | while (1) { |
925baedd CM |
160 | eb = btrfs_root_node(root); |
161 | btrfs_tree_lock(eb); | |
240f62c8 | 162 | if (eb == root->node) |
925baedd | 163 | break; |
925baedd CM |
164 | btrfs_tree_unlock(eb); |
165 | free_extent_buffer(eb); | |
166 | } | |
167 | return eb; | |
168 | } | |
169 | ||
d352ac68 CM |
170 | /* cowonly root (everything not a reference counted cow subvolume), just get |
171 | * put onto a simple dirty list. transaction.c walks this to make sure they | |
172 | * get properly updated on disk. | |
173 | */ | |
0b86a832 CM |
174 | static void add_root_to_dirty_list(struct btrfs_root *root) |
175 | { | |
176 | if (root->track_dirty && list_empty(&root->dirty_list)) { | |
177 | list_add(&root->dirty_list, | |
178 | &root->fs_info->dirty_cowonly_roots); | |
179 | } | |
180 | } | |
181 | ||
d352ac68 CM |
182 | /* |
183 | * used by snapshot creation to make a copy of a root for a tree with | |
184 | * a given objectid. The buffer with the new root node is returned in | |
185 | * cow_ret, and this func returns zero on success or a negative error code. | |
186 | */ | |
be20aa9d CM |
187 | int btrfs_copy_root(struct btrfs_trans_handle *trans, |
188 | struct btrfs_root *root, | |
189 | struct extent_buffer *buf, | |
190 | struct extent_buffer **cow_ret, u64 new_root_objectid) | |
191 | { | |
192 | struct extent_buffer *cow; | |
be20aa9d CM |
193 | int ret = 0; |
194 | int level; | |
5d4f98a2 | 195 | struct btrfs_disk_key disk_key; |
be20aa9d CM |
196 | |
197 | WARN_ON(root->ref_cows && trans->transid != | |
198 | root->fs_info->running_transaction->transid); | |
199 | WARN_ON(root->ref_cows && trans->transid != root->last_trans); | |
200 | ||
201 | level = btrfs_header_level(buf); | |
5d4f98a2 YZ |
202 | if (level == 0) |
203 | btrfs_item_key(buf, &disk_key, 0); | |
204 | else | |
205 | btrfs_node_key(buf, &disk_key, 0); | |
31840ae1 | 206 | |
5d4f98a2 YZ |
207 | cow = btrfs_alloc_free_block(trans, root, buf->len, 0, |
208 | new_root_objectid, &disk_key, level, | |
209 | buf->start, 0); | |
210 | if (IS_ERR(cow)) | |
be20aa9d CM |
211 | return PTR_ERR(cow); |
212 | ||
213 | copy_extent_buffer(cow, buf, 0, 0, cow->len); | |
214 | btrfs_set_header_bytenr(cow, cow->start); | |
215 | btrfs_set_header_generation(cow, trans->transid); | |
5d4f98a2 YZ |
216 | btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV); |
217 | btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN | | |
218 | BTRFS_HEADER_FLAG_RELOC); | |
219 | if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID) | |
220 | btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC); | |
221 | else | |
222 | btrfs_set_header_owner(cow, new_root_objectid); | |
be20aa9d | 223 | |
2b82032c YZ |
224 | write_extent_buffer(cow, root->fs_info->fsid, |
225 | (unsigned long)btrfs_header_fsid(cow), | |
226 | BTRFS_FSID_SIZE); | |
227 | ||
be20aa9d | 228 | WARN_ON(btrfs_header_generation(buf) > trans->transid); |
5d4f98a2 YZ |
229 | if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID) |
230 | ret = btrfs_inc_ref(trans, root, cow, 1); | |
231 | else | |
232 | ret = btrfs_inc_ref(trans, root, cow, 0); | |
4aec2b52 | 233 | |
be20aa9d CM |
234 | if (ret) |
235 | return ret; | |
236 | ||
237 | btrfs_mark_buffer_dirty(cow); | |
238 | *cow_ret = cow; | |
239 | return 0; | |
240 | } | |
241 | ||
5d4f98a2 YZ |
242 | /* |
243 | * check if the tree block can be shared by multiple trees | |
244 | */ | |
245 | int btrfs_block_can_be_shared(struct btrfs_root *root, | |
246 | struct extent_buffer *buf) | |
247 | { | |
248 | /* | |
249 | * Tree blocks not in refernece counted trees and tree roots | |
250 | * are never shared. If a block was allocated after the last | |
251 | * snapshot and the block was not allocated by tree relocation, | |
252 | * we know the block is not shared. | |
253 | */ | |
254 | if (root->ref_cows && | |
255 | buf != root->node && buf != root->commit_root && | |
256 | (btrfs_header_generation(buf) <= | |
257 | btrfs_root_last_snapshot(&root->root_item) || | |
258 | btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC))) | |
259 | return 1; | |
260 | #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 | |
261 | if (root->ref_cows && | |
262 | btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) | |
263 | return 1; | |
264 | #endif | |
265 | return 0; | |
266 | } | |
267 | ||
268 | static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans, | |
269 | struct btrfs_root *root, | |
270 | struct extent_buffer *buf, | |
f0486c68 YZ |
271 | struct extent_buffer *cow, |
272 | int *last_ref) | |
5d4f98a2 YZ |
273 | { |
274 | u64 refs; | |
275 | u64 owner; | |
276 | u64 flags; | |
277 | u64 new_flags = 0; | |
278 | int ret; | |
279 | ||
280 | /* | |
281 | * Backrefs update rules: | |
282 | * | |
283 | * Always use full backrefs for extent pointers in tree block | |
284 | * allocated by tree relocation. | |
285 | * | |
286 | * If a shared tree block is no longer referenced by its owner | |
287 | * tree (btrfs_header_owner(buf) == root->root_key.objectid), | |
288 | * use full backrefs for extent pointers in tree block. | |
289 | * | |
290 | * If a tree block is been relocating | |
291 | * (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID), | |
292 | * use full backrefs for extent pointers in tree block. | |
293 | * The reason for this is some operations (such as drop tree) | |
294 | * are only allowed for blocks use full backrefs. | |
295 | */ | |
296 | ||
297 | if (btrfs_block_can_be_shared(root, buf)) { | |
298 | ret = btrfs_lookup_extent_info(trans, root, buf->start, | |
299 | buf->len, &refs, &flags); | |
300 | BUG_ON(ret); | |
301 | BUG_ON(refs == 0); | |
302 | } else { | |
303 | refs = 1; | |
304 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID || | |
305 | btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) | |
306 | flags = BTRFS_BLOCK_FLAG_FULL_BACKREF; | |
307 | else | |
308 | flags = 0; | |
309 | } | |
310 | ||
311 | owner = btrfs_header_owner(buf); | |
312 | BUG_ON(owner == BTRFS_TREE_RELOC_OBJECTID && | |
313 | !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)); | |
314 | ||
315 | if (refs > 1) { | |
316 | if ((owner == root->root_key.objectid || | |
317 | root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) && | |
318 | !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)) { | |
319 | ret = btrfs_inc_ref(trans, root, buf, 1); | |
320 | BUG_ON(ret); | |
321 | ||
322 | if (root->root_key.objectid == | |
323 | BTRFS_TREE_RELOC_OBJECTID) { | |
324 | ret = btrfs_dec_ref(trans, root, buf, 0); | |
325 | BUG_ON(ret); | |
326 | ret = btrfs_inc_ref(trans, root, cow, 1); | |
327 | BUG_ON(ret); | |
328 | } | |
329 | new_flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF; | |
330 | } else { | |
331 | ||
332 | if (root->root_key.objectid == | |
333 | BTRFS_TREE_RELOC_OBJECTID) | |
334 | ret = btrfs_inc_ref(trans, root, cow, 1); | |
335 | else | |
336 | ret = btrfs_inc_ref(trans, root, cow, 0); | |
337 | BUG_ON(ret); | |
338 | } | |
339 | if (new_flags != 0) { | |
340 | ret = btrfs_set_disk_extent_flags(trans, root, | |
341 | buf->start, | |
342 | buf->len, | |
343 | new_flags, 0); | |
344 | BUG_ON(ret); | |
345 | } | |
346 | } else { | |
347 | if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF) { | |
348 | if (root->root_key.objectid == | |
349 | BTRFS_TREE_RELOC_OBJECTID) | |
350 | ret = btrfs_inc_ref(trans, root, cow, 1); | |
351 | else | |
352 | ret = btrfs_inc_ref(trans, root, cow, 0); | |
353 | BUG_ON(ret); | |
354 | ret = btrfs_dec_ref(trans, root, buf, 1); | |
355 | BUG_ON(ret); | |
356 | } | |
357 | clean_tree_block(trans, root, buf); | |
f0486c68 | 358 | *last_ref = 1; |
5d4f98a2 YZ |
359 | } |
360 | return 0; | |
361 | } | |
362 | ||
d352ac68 | 363 | /* |
d397712b CM |
364 | * does the dirty work in cow of a single block. The parent block (if |
365 | * supplied) is updated to point to the new cow copy. The new buffer is marked | |
366 | * dirty and returned locked. If you modify the block it needs to be marked | |
367 | * dirty again. | |
d352ac68 CM |
368 | * |
369 | * search_start -- an allocation hint for the new block | |
370 | * | |
d397712b CM |
371 | * empty_size -- a hint that you plan on doing more cow. This is the size in |
372 | * bytes the allocator should try to find free next to the block it returns. | |
373 | * This is just a hint and may be ignored by the allocator. | |
d352ac68 | 374 | */ |
d397712b | 375 | static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans, |
5f39d397 CM |
376 | struct btrfs_root *root, |
377 | struct extent_buffer *buf, | |
378 | struct extent_buffer *parent, int parent_slot, | |
379 | struct extent_buffer **cow_ret, | |
9fa8cfe7 | 380 | u64 search_start, u64 empty_size) |
02217ed2 | 381 | { |
5d4f98a2 | 382 | struct btrfs_disk_key disk_key; |
5f39d397 | 383 | struct extent_buffer *cow; |
7bb86316 | 384 | int level; |
f0486c68 | 385 | int last_ref = 0; |
925baedd | 386 | int unlock_orig = 0; |
5d4f98a2 | 387 | u64 parent_start; |
7bb86316 | 388 | |
925baedd CM |
389 | if (*cow_ret == buf) |
390 | unlock_orig = 1; | |
391 | ||
b9447ef8 | 392 | btrfs_assert_tree_locked(buf); |
925baedd | 393 | |
7bb86316 CM |
394 | WARN_ON(root->ref_cows && trans->transid != |
395 | root->fs_info->running_transaction->transid); | |
6702ed49 | 396 | WARN_ON(root->ref_cows && trans->transid != root->last_trans); |
5f39d397 | 397 | |
7bb86316 | 398 | level = btrfs_header_level(buf); |
31840ae1 | 399 | |
5d4f98a2 YZ |
400 | if (level == 0) |
401 | btrfs_item_key(buf, &disk_key, 0); | |
402 | else | |
403 | btrfs_node_key(buf, &disk_key, 0); | |
404 | ||
405 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) { | |
406 | if (parent) | |
407 | parent_start = parent->start; | |
408 | else | |
409 | parent_start = 0; | |
410 | } else | |
411 | parent_start = 0; | |
412 | ||
413 | cow = btrfs_alloc_free_block(trans, root, buf->len, parent_start, | |
414 | root->root_key.objectid, &disk_key, | |
415 | level, search_start, empty_size); | |
54aa1f4d CM |
416 | if (IS_ERR(cow)) |
417 | return PTR_ERR(cow); | |
6702ed49 | 418 | |
b4ce94de CM |
419 | /* cow is set to blocking by btrfs_init_new_buffer */ |
420 | ||
5f39d397 | 421 | copy_extent_buffer(cow, buf, 0, 0, cow->len); |
db94535d | 422 | btrfs_set_header_bytenr(cow, cow->start); |
5f39d397 | 423 | btrfs_set_header_generation(cow, trans->transid); |
5d4f98a2 YZ |
424 | btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV); |
425 | btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN | | |
426 | BTRFS_HEADER_FLAG_RELOC); | |
427 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) | |
428 | btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC); | |
429 | else | |
430 | btrfs_set_header_owner(cow, root->root_key.objectid); | |
6702ed49 | 431 | |
2b82032c YZ |
432 | write_extent_buffer(cow, root->fs_info->fsid, |
433 | (unsigned long)btrfs_header_fsid(cow), | |
434 | BTRFS_FSID_SIZE); | |
435 | ||
f0486c68 | 436 | update_ref_for_cow(trans, root, buf, cow, &last_ref); |
1a40e23b | 437 | |
3fd0a558 YZ |
438 | if (root->ref_cows) |
439 | btrfs_reloc_cow_block(trans, root, buf, cow); | |
440 | ||
02217ed2 | 441 | if (buf == root->node) { |
925baedd | 442 | WARN_ON(parent && parent != buf); |
5d4f98a2 YZ |
443 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID || |
444 | btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) | |
445 | parent_start = buf->start; | |
446 | else | |
447 | parent_start = 0; | |
925baedd | 448 | |
5f39d397 | 449 | extent_buffer_get(cow); |
240f62c8 | 450 | rcu_assign_pointer(root->node, cow); |
925baedd | 451 | |
f0486c68 YZ |
452 | btrfs_free_tree_block(trans, root, buf, parent_start, |
453 | last_ref); | |
5f39d397 | 454 | free_extent_buffer(buf); |
0b86a832 | 455 | add_root_to_dirty_list(root); |
02217ed2 | 456 | } else { |
5d4f98a2 YZ |
457 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) |
458 | parent_start = parent->start; | |
459 | else | |
460 | parent_start = 0; | |
461 | ||
462 | WARN_ON(trans->transid != btrfs_header_generation(parent)); | |
5f39d397 | 463 | btrfs_set_node_blockptr(parent, parent_slot, |
db94535d | 464 | cow->start); |
74493f7a CM |
465 | btrfs_set_node_ptr_generation(parent, parent_slot, |
466 | trans->transid); | |
d6025579 | 467 | btrfs_mark_buffer_dirty(parent); |
f0486c68 YZ |
468 | btrfs_free_tree_block(trans, root, buf, parent_start, |
469 | last_ref); | |
02217ed2 | 470 | } |
925baedd CM |
471 | if (unlock_orig) |
472 | btrfs_tree_unlock(buf); | |
5f39d397 | 473 | free_extent_buffer(buf); |
ccd467d6 | 474 | btrfs_mark_buffer_dirty(cow); |
2c90e5d6 | 475 | *cow_ret = cow; |
02217ed2 CM |
476 | return 0; |
477 | } | |
478 | ||
5d4f98a2 YZ |
479 | static inline int should_cow_block(struct btrfs_trans_handle *trans, |
480 | struct btrfs_root *root, | |
481 | struct extent_buffer *buf) | |
482 | { | |
483 | if (btrfs_header_generation(buf) == trans->transid && | |
484 | !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN) && | |
485 | !(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID && | |
486 | btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC))) | |
487 | return 0; | |
488 | return 1; | |
489 | } | |
490 | ||
d352ac68 CM |
491 | /* |
492 | * cows a single block, see __btrfs_cow_block for the real work. | |
493 | * This version of it has extra checks so that a block isn't cow'd more than | |
494 | * once per transaction, as long as it hasn't been written yet | |
495 | */ | |
d397712b | 496 | noinline int btrfs_cow_block(struct btrfs_trans_handle *trans, |
5f39d397 CM |
497 | struct btrfs_root *root, struct extent_buffer *buf, |
498 | struct extent_buffer *parent, int parent_slot, | |
9fa8cfe7 | 499 | struct extent_buffer **cow_ret) |
6702ed49 CM |
500 | { |
501 | u64 search_start; | |
f510cfec | 502 | int ret; |
dc17ff8f | 503 | |
6702ed49 | 504 | if (trans->transaction != root->fs_info->running_transaction) { |
d397712b CM |
505 | printk(KERN_CRIT "trans %llu running %llu\n", |
506 | (unsigned long long)trans->transid, | |
507 | (unsigned long long) | |
6702ed49 CM |
508 | root->fs_info->running_transaction->transid); |
509 | WARN_ON(1); | |
510 | } | |
511 | if (trans->transid != root->fs_info->generation) { | |
d397712b CM |
512 | printk(KERN_CRIT "trans %llu running %llu\n", |
513 | (unsigned long long)trans->transid, | |
514 | (unsigned long long)root->fs_info->generation); | |
6702ed49 CM |
515 | WARN_ON(1); |
516 | } | |
dc17ff8f | 517 | |
5d4f98a2 | 518 | if (!should_cow_block(trans, root, buf)) { |
6702ed49 CM |
519 | *cow_ret = buf; |
520 | return 0; | |
521 | } | |
c487685d | 522 | |
0b86a832 | 523 | search_start = buf->start & ~((u64)(1024 * 1024 * 1024) - 1); |
b4ce94de CM |
524 | |
525 | if (parent) | |
526 | btrfs_set_lock_blocking(parent); | |
527 | btrfs_set_lock_blocking(buf); | |
528 | ||
f510cfec | 529 | ret = __btrfs_cow_block(trans, root, buf, parent, |
9fa8cfe7 | 530 | parent_slot, cow_ret, search_start, 0); |
1abe9b8a | 531 | |
532 | trace_btrfs_cow_block(root, buf, *cow_ret); | |
533 | ||
f510cfec | 534 | return ret; |
6702ed49 CM |
535 | } |
536 | ||
d352ac68 CM |
537 | /* |
538 | * helper function for defrag to decide if two blocks pointed to by a | |
539 | * node are actually close by | |
540 | */ | |
6b80053d | 541 | static int close_blocks(u64 blocknr, u64 other, u32 blocksize) |
6702ed49 | 542 | { |
6b80053d | 543 | if (blocknr < other && other - (blocknr + blocksize) < 32768) |
6702ed49 | 544 | return 1; |
6b80053d | 545 | if (blocknr > other && blocknr - (other + blocksize) < 32768) |
6702ed49 CM |
546 | return 1; |
547 | return 0; | |
548 | } | |
549 | ||
081e9573 CM |
550 | /* |
551 | * compare two keys in a memcmp fashion | |
552 | */ | |
553 | static int comp_keys(struct btrfs_disk_key *disk, struct btrfs_key *k2) | |
554 | { | |
555 | struct btrfs_key k1; | |
556 | ||
557 | btrfs_disk_key_to_cpu(&k1, disk); | |
558 | ||
20736aba | 559 | return btrfs_comp_cpu_keys(&k1, k2); |
081e9573 CM |
560 | } |
561 | ||
f3465ca4 JB |
562 | /* |
563 | * same as comp_keys only with two btrfs_key's | |
564 | */ | |
5d4f98a2 | 565 | int btrfs_comp_cpu_keys(struct btrfs_key *k1, struct btrfs_key *k2) |
f3465ca4 JB |
566 | { |
567 | if (k1->objectid > k2->objectid) | |
568 | return 1; | |
569 | if (k1->objectid < k2->objectid) | |
570 | return -1; | |
571 | if (k1->type > k2->type) | |
572 | return 1; | |
573 | if (k1->type < k2->type) | |
574 | return -1; | |
575 | if (k1->offset > k2->offset) | |
576 | return 1; | |
577 | if (k1->offset < k2->offset) | |
578 | return -1; | |
579 | return 0; | |
580 | } | |
081e9573 | 581 | |
d352ac68 CM |
582 | /* |
583 | * this is used by the defrag code to go through all the | |
584 | * leaves pointed to by a node and reallocate them so that | |
585 | * disk order is close to key order | |
586 | */ | |
6702ed49 | 587 | int btrfs_realloc_node(struct btrfs_trans_handle *trans, |
5f39d397 | 588 | struct btrfs_root *root, struct extent_buffer *parent, |
a6b6e75e CM |
589 | int start_slot, int cache_only, u64 *last_ret, |
590 | struct btrfs_key *progress) | |
6702ed49 | 591 | { |
6b80053d | 592 | struct extent_buffer *cur; |
6702ed49 | 593 | u64 blocknr; |
ca7a79ad | 594 | u64 gen; |
e9d0b13b CM |
595 | u64 search_start = *last_ret; |
596 | u64 last_block = 0; | |
6702ed49 CM |
597 | u64 other; |
598 | u32 parent_nritems; | |
6702ed49 CM |
599 | int end_slot; |
600 | int i; | |
601 | int err = 0; | |
f2183bde | 602 | int parent_level; |
6b80053d CM |
603 | int uptodate; |
604 | u32 blocksize; | |
081e9573 CM |
605 | int progress_passed = 0; |
606 | struct btrfs_disk_key disk_key; | |
6702ed49 | 607 | |
5708b959 CM |
608 | parent_level = btrfs_header_level(parent); |
609 | if (cache_only && parent_level != 1) | |
610 | return 0; | |
611 | ||
d397712b | 612 | if (trans->transaction != root->fs_info->running_transaction) |
6702ed49 | 613 | WARN_ON(1); |
d397712b | 614 | if (trans->transid != root->fs_info->generation) |
6702ed49 | 615 | WARN_ON(1); |
86479a04 | 616 | |
6b80053d | 617 | parent_nritems = btrfs_header_nritems(parent); |
6b80053d | 618 | blocksize = btrfs_level_size(root, parent_level - 1); |
6702ed49 CM |
619 | end_slot = parent_nritems; |
620 | ||
621 | if (parent_nritems == 1) | |
622 | return 0; | |
623 | ||
b4ce94de CM |
624 | btrfs_set_lock_blocking(parent); |
625 | ||
6702ed49 CM |
626 | for (i = start_slot; i < end_slot; i++) { |
627 | int close = 1; | |
a6b6e75e | 628 | |
5708b959 CM |
629 | if (!parent->map_token) { |
630 | map_extent_buffer(parent, | |
631 | btrfs_node_key_ptr_offset(i), | |
632 | sizeof(struct btrfs_key_ptr), | |
633 | &parent->map_token, &parent->kaddr, | |
634 | &parent->map_start, &parent->map_len, | |
635 | KM_USER1); | |
636 | } | |
081e9573 CM |
637 | btrfs_node_key(parent, &disk_key, i); |
638 | if (!progress_passed && comp_keys(&disk_key, progress) < 0) | |
639 | continue; | |
640 | ||
641 | progress_passed = 1; | |
6b80053d | 642 | blocknr = btrfs_node_blockptr(parent, i); |
ca7a79ad | 643 | gen = btrfs_node_ptr_generation(parent, i); |
e9d0b13b CM |
644 | if (last_block == 0) |
645 | last_block = blocknr; | |
5708b959 | 646 | |
6702ed49 | 647 | if (i > 0) { |
6b80053d CM |
648 | other = btrfs_node_blockptr(parent, i - 1); |
649 | close = close_blocks(blocknr, other, blocksize); | |
6702ed49 | 650 | } |
0ef3e66b | 651 | if (!close && i < end_slot - 2) { |
6b80053d CM |
652 | other = btrfs_node_blockptr(parent, i + 1); |
653 | close = close_blocks(blocknr, other, blocksize); | |
6702ed49 | 654 | } |
e9d0b13b CM |
655 | if (close) { |
656 | last_block = blocknr; | |
6702ed49 | 657 | continue; |
e9d0b13b | 658 | } |
5708b959 CM |
659 | if (parent->map_token) { |
660 | unmap_extent_buffer(parent, parent->map_token, | |
661 | KM_USER1); | |
662 | parent->map_token = NULL; | |
663 | } | |
6702ed49 | 664 | |
6b80053d CM |
665 | cur = btrfs_find_tree_block(root, blocknr, blocksize); |
666 | if (cur) | |
1259ab75 | 667 | uptodate = btrfs_buffer_uptodate(cur, gen); |
6b80053d CM |
668 | else |
669 | uptodate = 0; | |
5708b959 | 670 | if (!cur || !uptodate) { |
6702ed49 | 671 | if (cache_only) { |
6b80053d | 672 | free_extent_buffer(cur); |
6702ed49 CM |
673 | continue; |
674 | } | |
6b80053d CM |
675 | if (!cur) { |
676 | cur = read_tree_block(root, blocknr, | |
ca7a79ad | 677 | blocksize, gen); |
97d9a8a4 TI |
678 | if (!cur) |
679 | return -EIO; | |
6b80053d | 680 | } else if (!uptodate) { |
ca7a79ad | 681 | btrfs_read_buffer(cur, gen); |
f2183bde | 682 | } |
6702ed49 | 683 | } |
e9d0b13b | 684 | if (search_start == 0) |
6b80053d | 685 | search_start = last_block; |
e9d0b13b | 686 | |
e7a84565 | 687 | btrfs_tree_lock(cur); |
b4ce94de | 688 | btrfs_set_lock_blocking(cur); |
6b80053d | 689 | err = __btrfs_cow_block(trans, root, cur, parent, i, |
e7a84565 | 690 | &cur, search_start, |
6b80053d | 691 | min(16 * blocksize, |
9fa8cfe7 | 692 | (end_slot - i) * blocksize)); |
252c38f0 | 693 | if (err) { |
e7a84565 | 694 | btrfs_tree_unlock(cur); |
6b80053d | 695 | free_extent_buffer(cur); |
6702ed49 | 696 | break; |
252c38f0 | 697 | } |
e7a84565 CM |
698 | search_start = cur->start; |
699 | last_block = cur->start; | |
f2183bde | 700 | *last_ret = search_start; |
e7a84565 CM |
701 | btrfs_tree_unlock(cur); |
702 | free_extent_buffer(cur); | |
6702ed49 | 703 | } |
5708b959 CM |
704 | if (parent->map_token) { |
705 | unmap_extent_buffer(parent, parent->map_token, | |
706 | KM_USER1); | |
707 | parent->map_token = NULL; | |
708 | } | |
6702ed49 CM |
709 | return err; |
710 | } | |
711 | ||
74123bd7 CM |
712 | /* |
713 | * The leaf data grows from end-to-front in the node. | |
714 | * this returns the address of the start of the last item, | |
715 | * which is the stop of the leaf data stack | |
716 | */ | |
123abc88 | 717 | static inline unsigned int leaf_data_end(struct btrfs_root *root, |
5f39d397 | 718 | struct extent_buffer *leaf) |
be0e5c09 | 719 | { |
5f39d397 | 720 | u32 nr = btrfs_header_nritems(leaf); |
be0e5c09 | 721 | if (nr == 0) |
123abc88 | 722 | return BTRFS_LEAF_DATA_SIZE(root); |
5f39d397 | 723 | return btrfs_item_offset_nr(leaf, nr - 1); |
be0e5c09 CM |
724 | } |
725 | ||
aa5d6bed | 726 | |
74123bd7 | 727 | /* |
5f39d397 CM |
728 | * search for key in the extent_buffer. The items start at offset p, |
729 | * and they are item_size apart. There are 'max' items in p. | |
730 | * | |
74123bd7 CM |
731 | * the slot in the array is returned via slot, and it points to |
732 | * the place where you would insert key if it is not found in | |
733 | * the array. | |
734 | * | |
735 | * slot may point to max if the key is bigger than all of the keys | |
736 | */ | |
e02119d5 CM |
737 | static noinline int generic_bin_search(struct extent_buffer *eb, |
738 | unsigned long p, | |
739 | int item_size, struct btrfs_key *key, | |
740 | int max, int *slot) | |
be0e5c09 CM |
741 | { |
742 | int low = 0; | |
743 | int high = max; | |
744 | int mid; | |
745 | int ret; | |
479965d6 | 746 | struct btrfs_disk_key *tmp = NULL; |
5f39d397 CM |
747 | struct btrfs_disk_key unaligned; |
748 | unsigned long offset; | |
749 | char *map_token = NULL; | |
750 | char *kaddr = NULL; | |
751 | unsigned long map_start = 0; | |
752 | unsigned long map_len = 0; | |
479965d6 | 753 | int err; |
be0e5c09 | 754 | |
d397712b | 755 | while (low < high) { |
be0e5c09 | 756 | mid = (low + high) / 2; |
5f39d397 CM |
757 | offset = p + mid * item_size; |
758 | ||
759 | if (!map_token || offset < map_start || | |
760 | (offset + sizeof(struct btrfs_disk_key)) > | |
761 | map_start + map_len) { | |
479965d6 | 762 | if (map_token) { |
5f39d397 | 763 | unmap_extent_buffer(eb, map_token, KM_USER0); |
479965d6 CM |
764 | map_token = NULL; |
765 | } | |
934d375b CM |
766 | |
767 | err = map_private_extent_buffer(eb, offset, | |
479965d6 CM |
768 | sizeof(struct btrfs_disk_key), |
769 | &map_token, &kaddr, | |
770 | &map_start, &map_len, KM_USER0); | |
771 | ||
772 | if (!err) { | |
773 | tmp = (struct btrfs_disk_key *)(kaddr + offset - | |
774 | map_start); | |
775 | } else { | |
776 | read_extent_buffer(eb, &unaligned, | |
777 | offset, sizeof(unaligned)); | |
778 | tmp = &unaligned; | |
779 | } | |
5f39d397 | 780 | |
5f39d397 CM |
781 | } else { |
782 | tmp = (struct btrfs_disk_key *)(kaddr + offset - | |
783 | map_start); | |
784 | } | |
be0e5c09 CM |
785 | ret = comp_keys(tmp, key); |
786 | ||
787 | if (ret < 0) | |
788 | low = mid + 1; | |
789 | else if (ret > 0) | |
790 | high = mid; | |
791 | else { | |
792 | *slot = mid; | |
479965d6 CM |
793 | if (map_token) |
794 | unmap_extent_buffer(eb, map_token, KM_USER0); | |
be0e5c09 CM |
795 | return 0; |
796 | } | |
797 | } | |
798 | *slot = low; | |
5f39d397 CM |
799 | if (map_token) |
800 | unmap_extent_buffer(eb, map_token, KM_USER0); | |
be0e5c09 CM |
801 | return 1; |
802 | } | |
803 | ||
97571fd0 CM |
804 | /* |
805 | * simple bin_search frontend that does the right thing for | |
806 | * leaves vs nodes | |
807 | */ | |
5f39d397 CM |
808 | static int bin_search(struct extent_buffer *eb, struct btrfs_key *key, |
809 | int level, int *slot) | |
be0e5c09 | 810 | { |
5f39d397 CM |
811 | if (level == 0) { |
812 | return generic_bin_search(eb, | |
813 | offsetof(struct btrfs_leaf, items), | |
0783fcfc | 814 | sizeof(struct btrfs_item), |
5f39d397 | 815 | key, btrfs_header_nritems(eb), |
7518a238 | 816 | slot); |
be0e5c09 | 817 | } else { |
5f39d397 CM |
818 | return generic_bin_search(eb, |
819 | offsetof(struct btrfs_node, ptrs), | |
123abc88 | 820 | sizeof(struct btrfs_key_ptr), |
5f39d397 | 821 | key, btrfs_header_nritems(eb), |
7518a238 | 822 | slot); |
be0e5c09 CM |
823 | } |
824 | return -1; | |
825 | } | |
826 | ||
5d4f98a2 YZ |
827 | int btrfs_bin_search(struct extent_buffer *eb, struct btrfs_key *key, |
828 | int level, int *slot) | |
829 | { | |
830 | return bin_search(eb, key, level, slot); | |
831 | } | |
832 | ||
f0486c68 YZ |
833 | static void root_add_used(struct btrfs_root *root, u32 size) |
834 | { | |
835 | spin_lock(&root->accounting_lock); | |
836 | btrfs_set_root_used(&root->root_item, | |
837 | btrfs_root_used(&root->root_item) + size); | |
838 | spin_unlock(&root->accounting_lock); | |
839 | } | |
840 | ||
841 | static void root_sub_used(struct btrfs_root *root, u32 size) | |
842 | { | |
843 | spin_lock(&root->accounting_lock); | |
844 | btrfs_set_root_used(&root->root_item, | |
845 | btrfs_root_used(&root->root_item) - size); | |
846 | spin_unlock(&root->accounting_lock); | |
847 | } | |
848 | ||
d352ac68 CM |
849 | /* given a node and slot number, this reads the blocks it points to. The |
850 | * extent buffer is returned with a reference taken (but unlocked). | |
851 | * NULL is returned on error. | |
852 | */ | |
e02119d5 | 853 | static noinline struct extent_buffer *read_node_slot(struct btrfs_root *root, |
5f39d397 | 854 | struct extent_buffer *parent, int slot) |
bb803951 | 855 | { |
ca7a79ad | 856 | int level = btrfs_header_level(parent); |
bb803951 CM |
857 | if (slot < 0) |
858 | return NULL; | |
5f39d397 | 859 | if (slot >= btrfs_header_nritems(parent)) |
bb803951 | 860 | return NULL; |
ca7a79ad CM |
861 | |
862 | BUG_ON(level == 0); | |
863 | ||
db94535d | 864 | return read_tree_block(root, btrfs_node_blockptr(parent, slot), |
ca7a79ad CM |
865 | btrfs_level_size(root, level - 1), |
866 | btrfs_node_ptr_generation(parent, slot)); | |
bb803951 CM |
867 | } |
868 | ||
d352ac68 CM |
869 | /* |
870 | * node level balancing, used to make sure nodes are in proper order for | |
871 | * item deletion. We balance from the top down, so we have to make sure | |
872 | * that a deletion won't leave an node completely empty later on. | |
873 | */ | |
e02119d5 | 874 | static noinline int balance_level(struct btrfs_trans_handle *trans, |
98ed5174 CM |
875 | struct btrfs_root *root, |
876 | struct btrfs_path *path, int level) | |
bb803951 | 877 | { |
5f39d397 CM |
878 | struct extent_buffer *right = NULL; |
879 | struct extent_buffer *mid; | |
880 | struct extent_buffer *left = NULL; | |
881 | struct extent_buffer *parent = NULL; | |
bb803951 CM |
882 | int ret = 0; |
883 | int wret; | |
884 | int pslot; | |
bb803951 | 885 | int orig_slot = path->slots[level]; |
79f95c82 | 886 | u64 orig_ptr; |
bb803951 CM |
887 | |
888 | if (level == 0) | |
889 | return 0; | |
890 | ||
5f39d397 | 891 | mid = path->nodes[level]; |
b4ce94de | 892 | |
925baedd | 893 | WARN_ON(!path->locks[level]); |
7bb86316 CM |
894 | WARN_ON(btrfs_header_generation(mid) != trans->transid); |
895 | ||
1d4f8a0c | 896 | orig_ptr = btrfs_node_blockptr(mid, orig_slot); |
79f95c82 | 897 | |
234b63a0 | 898 | if (level < BTRFS_MAX_LEVEL - 1) |
5f39d397 | 899 | parent = path->nodes[level + 1]; |
bb803951 CM |
900 | pslot = path->slots[level + 1]; |
901 | ||
40689478 CM |
902 | /* |
903 | * deal with the case where there is only one pointer in the root | |
904 | * by promoting the node below to a root | |
905 | */ | |
5f39d397 CM |
906 | if (!parent) { |
907 | struct extent_buffer *child; | |
bb803951 | 908 | |
5f39d397 | 909 | if (btrfs_header_nritems(mid) != 1) |
bb803951 CM |
910 | return 0; |
911 | ||
912 | /* promote the child to a root */ | |
5f39d397 | 913 | child = read_node_slot(root, mid, 0); |
7951f3ce | 914 | BUG_ON(!child); |
925baedd | 915 | btrfs_tree_lock(child); |
b4ce94de | 916 | btrfs_set_lock_blocking(child); |
9fa8cfe7 | 917 | ret = btrfs_cow_block(trans, root, child, mid, 0, &child); |
f0486c68 YZ |
918 | if (ret) { |
919 | btrfs_tree_unlock(child); | |
920 | free_extent_buffer(child); | |
921 | goto enospc; | |
922 | } | |
2f375ab9 | 923 | |
240f62c8 | 924 | rcu_assign_pointer(root->node, child); |
925baedd | 925 | |
0b86a832 | 926 | add_root_to_dirty_list(root); |
925baedd | 927 | btrfs_tree_unlock(child); |
b4ce94de | 928 | |
925baedd | 929 | path->locks[level] = 0; |
bb803951 | 930 | path->nodes[level] = NULL; |
5f39d397 | 931 | clean_tree_block(trans, root, mid); |
925baedd | 932 | btrfs_tree_unlock(mid); |
bb803951 | 933 | /* once for the path */ |
5f39d397 | 934 | free_extent_buffer(mid); |
f0486c68 YZ |
935 | |
936 | root_sub_used(root, mid->len); | |
937 | btrfs_free_tree_block(trans, root, mid, 0, 1); | |
bb803951 | 938 | /* once for the root ptr */ |
5f39d397 | 939 | free_extent_buffer(mid); |
f0486c68 | 940 | return 0; |
bb803951 | 941 | } |
5f39d397 | 942 | if (btrfs_header_nritems(mid) > |
123abc88 | 943 | BTRFS_NODEPTRS_PER_BLOCK(root) / 4) |
bb803951 CM |
944 | return 0; |
945 | ||
559af821 | 946 | btrfs_header_nritems(mid); |
54aa1f4d | 947 | |
5f39d397 CM |
948 | left = read_node_slot(root, parent, pslot - 1); |
949 | if (left) { | |
925baedd | 950 | btrfs_tree_lock(left); |
b4ce94de | 951 | btrfs_set_lock_blocking(left); |
5f39d397 | 952 | wret = btrfs_cow_block(trans, root, left, |
9fa8cfe7 | 953 | parent, pslot - 1, &left); |
54aa1f4d CM |
954 | if (wret) { |
955 | ret = wret; | |
956 | goto enospc; | |
957 | } | |
2cc58cf2 | 958 | } |
5f39d397 CM |
959 | right = read_node_slot(root, parent, pslot + 1); |
960 | if (right) { | |
925baedd | 961 | btrfs_tree_lock(right); |
b4ce94de | 962 | btrfs_set_lock_blocking(right); |
5f39d397 | 963 | wret = btrfs_cow_block(trans, root, right, |
9fa8cfe7 | 964 | parent, pslot + 1, &right); |
2cc58cf2 CM |
965 | if (wret) { |
966 | ret = wret; | |
967 | goto enospc; | |
968 | } | |
969 | } | |
970 | ||
971 | /* first, try to make some room in the middle buffer */ | |
5f39d397 CM |
972 | if (left) { |
973 | orig_slot += btrfs_header_nritems(left); | |
bce4eae9 | 974 | wret = push_node_left(trans, root, left, mid, 1); |
79f95c82 CM |
975 | if (wret < 0) |
976 | ret = wret; | |
559af821 | 977 | btrfs_header_nritems(mid); |
bb803951 | 978 | } |
79f95c82 CM |
979 | |
980 | /* | |
981 | * then try to empty the right most buffer into the middle | |
982 | */ | |
5f39d397 | 983 | if (right) { |
971a1f66 | 984 | wret = push_node_left(trans, root, mid, right, 1); |
54aa1f4d | 985 | if (wret < 0 && wret != -ENOSPC) |
79f95c82 | 986 | ret = wret; |
5f39d397 | 987 | if (btrfs_header_nritems(right) == 0) { |
5f39d397 | 988 | clean_tree_block(trans, root, right); |
925baedd | 989 | btrfs_tree_unlock(right); |
e089f05c CM |
990 | wret = del_ptr(trans, root, path, level + 1, pslot + |
991 | 1); | |
bb803951 CM |
992 | if (wret) |
993 | ret = wret; | |
f0486c68 YZ |
994 | root_sub_used(root, right->len); |
995 | btrfs_free_tree_block(trans, root, right, 0, 1); | |
996 | free_extent_buffer(right); | |
997 | right = NULL; | |
bb803951 | 998 | } else { |
5f39d397 CM |
999 | struct btrfs_disk_key right_key; |
1000 | btrfs_node_key(right, &right_key, 0); | |
1001 | btrfs_set_node_key(parent, &right_key, pslot + 1); | |
1002 | btrfs_mark_buffer_dirty(parent); | |
bb803951 CM |
1003 | } |
1004 | } | |
5f39d397 | 1005 | if (btrfs_header_nritems(mid) == 1) { |
79f95c82 CM |
1006 | /* |
1007 | * we're not allowed to leave a node with one item in the | |
1008 | * tree during a delete. A deletion from lower in the tree | |
1009 | * could try to delete the only pointer in this node. | |
1010 | * So, pull some keys from the left. | |
1011 | * There has to be a left pointer at this point because | |
1012 | * otherwise we would have pulled some pointers from the | |
1013 | * right | |
1014 | */ | |
5f39d397 CM |
1015 | BUG_ON(!left); |
1016 | wret = balance_node_right(trans, root, mid, left); | |
54aa1f4d | 1017 | if (wret < 0) { |
79f95c82 | 1018 | ret = wret; |
54aa1f4d CM |
1019 | goto enospc; |
1020 | } | |
bce4eae9 CM |
1021 | if (wret == 1) { |
1022 | wret = push_node_left(trans, root, left, mid, 1); | |
1023 | if (wret < 0) | |
1024 | ret = wret; | |
1025 | } | |
79f95c82 CM |
1026 | BUG_ON(wret == 1); |
1027 | } | |
5f39d397 | 1028 | if (btrfs_header_nritems(mid) == 0) { |
5f39d397 | 1029 | clean_tree_block(trans, root, mid); |
925baedd | 1030 | btrfs_tree_unlock(mid); |
e089f05c | 1031 | wret = del_ptr(trans, root, path, level + 1, pslot); |
bb803951 CM |
1032 | if (wret) |
1033 | ret = wret; | |
f0486c68 YZ |
1034 | root_sub_used(root, mid->len); |
1035 | btrfs_free_tree_block(trans, root, mid, 0, 1); | |
1036 | free_extent_buffer(mid); | |
1037 | mid = NULL; | |
79f95c82 CM |
1038 | } else { |
1039 | /* update the parent key to reflect our changes */ | |
5f39d397 CM |
1040 | struct btrfs_disk_key mid_key; |
1041 | btrfs_node_key(mid, &mid_key, 0); | |
1042 | btrfs_set_node_key(parent, &mid_key, pslot); | |
1043 | btrfs_mark_buffer_dirty(parent); | |
79f95c82 | 1044 | } |
bb803951 | 1045 | |
79f95c82 | 1046 | /* update the path */ |
5f39d397 CM |
1047 | if (left) { |
1048 | if (btrfs_header_nritems(left) > orig_slot) { | |
1049 | extent_buffer_get(left); | |
925baedd | 1050 | /* left was locked after cow */ |
5f39d397 | 1051 | path->nodes[level] = left; |
bb803951 CM |
1052 | path->slots[level + 1] -= 1; |
1053 | path->slots[level] = orig_slot; | |
925baedd CM |
1054 | if (mid) { |
1055 | btrfs_tree_unlock(mid); | |
5f39d397 | 1056 | free_extent_buffer(mid); |
925baedd | 1057 | } |
bb803951 | 1058 | } else { |
5f39d397 | 1059 | orig_slot -= btrfs_header_nritems(left); |
bb803951 CM |
1060 | path->slots[level] = orig_slot; |
1061 | } | |
1062 | } | |
79f95c82 | 1063 | /* double check we haven't messed things up */ |
e20d96d6 | 1064 | if (orig_ptr != |
5f39d397 | 1065 | btrfs_node_blockptr(path->nodes[level], path->slots[level])) |
79f95c82 | 1066 | BUG(); |
54aa1f4d | 1067 | enospc: |
925baedd CM |
1068 | if (right) { |
1069 | btrfs_tree_unlock(right); | |
5f39d397 | 1070 | free_extent_buffer(right); |
925baedd CM |
1071 | } |
1072 | if (left) { | |
1073 | if (path->nodes[level] != left) | |
1074 | btrfs_tree_unlock(left); | |
5f39d397 | 1075 | free_extent_buffer(left); |
925baedd | 1076 | } |
bb803951 CM |
1077 | return ret; |
1078 | } | |
1079 | ||
d352ac68 CM |
1080 | /* Node balancing for insertion. Here we only split or push nodes around |
1081 | * when they are completely full. This is also done top down, so we | |
1082 | * have to be pessimistic. | |
1083 | */ | |
d397712b | 1084 | static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans, |
98ed5174 CM |
1085 | struct btrfs_root *root, |
1086 | struct btrfs_path *path, int level) | |
e66f709b | 1087 | { |
5f39d397 CM |
1088 | struct extent_buffer *right = NULL; |
1089 | struct extent_buffer *mid; | |
1090 | struct extent_buffer *left = NULL; | |
1091 | struct extent_buffer *parent = NULL; | |
e66f709b CM |
1092 | int ret = 0; |
1093 | int wret; | |
1094 | int pslot; | |
1095 | int orig_slot = path->slots[level]; | |
e66f709b CM |
1096 | |
1097 | if (level == 0) | |
1098 | return 1; | |
1099 | ||
5f39d397 | 1100 | mid = path->nodes[level]; |
7bb86316 | 1101 | WARN_ON(btrfs_header_generation(mid) != trans->transid); |
e66f709b CM |
1102 | |
1103 | if (level < BTRFS_MAX_LEVEL - 1) | |
5f39d397 | 1104 | parent = path->nodes[level + 1]; |
e66f709b CM |
1105 | pslot = path->slots[level + 1]; |
1106 | ||
5f39d397 | 1107 | if (!parent) |
e66f709b | 1108 | return 1; |
e66f709b | 1109 | |
5f39d397 | 1110 | left = read_node_slot(root, parent, pslot - 1); |
e66f709b CM |
1111 | |
1112 | /* first, try to make some room in the middle buffer */ | |
5f39d397 | 1113 | if (left) { |
e66f709b | 1114 | u32 left_nr; |
925baedd CM |
1115 | |
1116 | btrfs_tree_lock(left); | |
b4ce94de CM |
1117 | btrfs_set_lock_blocking(left); |
1118 | ||
5f39d397 | 1119 | left_nr = btrfs_header_nritems(left); |
33ade1f8 CM |
1120 | if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) { |
1121 | wret = 1; | |
1122 | } else { | |
5f39d397 | 1123 | ret = btrfs_cow_block(trans, root, left, parent, |
9fa8cfe7 | 1124 | pslot - 1, &left); |
54aa1f4d CM |
1125 | if (ret) |
1126 | wret = 1; | |
1127 | else { | |
54aa1f4d | 1128 | wret = push_node_left(trans, root, |
971a1f66 | 1129 | left, mid, 0); |
54aa1f4d | 1130 | } |
33ade1f8 | 1131 | } |
e66f709b CM |
1132 | if (wret < 0) |
1133 | ret = wret; | |
1134 | if (wret == 0) { | |
5f39d397 | 1135 | struct btrfs_disk_key disk_key; |
e66f709b | 1136 | orig_slot += left_nr; |
5f39d397 CM |
1137 | btrfs_node_key(mid, &disk_key, 0); |
1138 | btrfs_set_node_key(parent, &disk_key, pslot); | |
1139 | btrfs_mark_buffer_dirty(parent); | |
1140 | if (btrfs_header_nritems(left) > orig_slot) { | |
1141 | path->nodes[level] = left; | |
e66f709b CM |
1142 | path->slots[level + 1] -= 1; |
1143 | path->slots[level] = orig_slot; | |
925baedd | 1144 | btrfs_tree_unlock(mid); |
5f39d397 | 1145 | free_extent_buffer(mid); |
e66f709b CM |
1146 | } else { |
1147 | orig_slot -= | |
5f39d397 | 1148 | btrfs_header_nritems(left); |
e66f709b | 1149 | path->slots[level] = orig_slot; |
925baedd | 1150 | btrfs_tree_unlock(left); |
5f39d397 | 1151 | free_extent_buffer(left); |
e66f709b | 1152 | } |
e66f709b CM |
1153 | return 0; |
1154 | } | |
925baedd | 1155 | btrfs_tree_unlock(left); |
5f39d397 | 1156 | free_extent_buffer(left); |
e66f709b | 1157 | } |
925baedd | 1158 | right = read_node_slot(root, parent, pslot + 1); |
e66f709b CM |
1159 | |
1160 | /* | |
1161 | * then try to empty the right most buffer into the middle | |
1162 | */ | |
5f39d397 | 1163 | if (right) { |
33ade1f8 | 1164 | u32 right_nr; |
b4ce94de | 1165 | |
925baedd | 1166 | btrfs_tree_lock(right); |
b4ce94de CM |
1167 | btrfs_set_lock_blocking(right); |
1168 | ||
5f39d397 | 1169 | right_nr = btrfs_header_nritems(right); |
33ade1f8 CM |
1170 | if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) { |
1171 | wret = 1; | |
1172 | } else { | |
5f39d397 CM |
1173 | ret = btrfs_cow_block(trans, root, right, |
1174 | parent, pslot + 1, | |
9fa8cfe7 | 1175 | &right); |
54aa1f4d CM |
1176 | if (ret) |
1177 | wret = 1; | |
1178 | else { | |
54aa1f4d | 1179 | wret = balance_node_right(trans, root, |
5f39d397 | 1180 | right, mid); |
54aa1f4d | 1181 | } |
33ade1f8 | 1182 | } |
e66f709b CM |
1183 | if (wret < 0) |
1184 | ret = wret; | |
1185 | if (wret == 0) { | |
5f39d397 CM |
1186 | struct btrfs_disk_key disk_key; |
1187 | ||
1188 | btrfs_node_key(right, &disk_key, 0); | |
1189 | btrfs_set_node_key(parent, &disk_key, pslot + 1); | |
1190 | btrfs_mark_buffer_dirty(parent); | |
1191 | ||
1192 | if (btrfs_header_nritems(mid) <= orig_slot) { | |
1193 | path->nodes[level] = right; | |
e66f709b CM |
1194 | path->slots[level + 1] += 1; |
1195 | path->slots[level] = orig_slot - | |
5f39d397 | 1196 | btrfs_header_nritems(mid); |
925baedd | 1197 | btrfs_tree_unlock(mid); |
5f39d397 | 1198 | free_extent_buffer(mid); |
e66f709b | 1199 | } else { |
925baedd | 1200 | btrfs_tree_unlock(right); |
5f39d397 | 1201 | free_extent_buffer(right); |
e66f709b | 1202 | } |
e66f709b CM |
1203 | return 0; |
1204 | } | |
925baedd | 1205 | btrfs_tree_unlock(right); |
5f39d397 | 1206 | free_extent_buffer(right); |
e66f709b | 1207 | } |
e66f709b CM |
1208 | return 1; |
1209 | } | |
1210 | ||
3c69faec | 1211 | /* |
d352ac68 CM |
1212 | * readahead one full node of leaves, finding things that are close |
1213 | * to the block in 'slot', and triggering ra on them. | |
3c69faec | 1214 | */ |
c8c42864 CM |
1215 | static void reada_for_search(struct btrfs_root *root, |
1216 | struct btrfs_path *path, | |
1217 | int level, int slot, u64 objectid) | |
3c69faec | 1218 | { |
5f39d397 | 1219 | struct extent_buffer *node; |
01f46658 | 1220 | struct btrfs_disk_key disk_key; |
3c69faec | 1221 | u32 nritems; |
3c69faec | 1222 | u64 search; |
a7175319 | 1223 | u64 target; |
6b80053d | 1224 | u64 nread = 0; |
cb25c2ea | 1225 | u64 gen; |
3c69faec | 1226 | int direction = path->reada; |
5f39d397 | 1227 | struct extent_buffer *eb; |
6b80053d CM |
1228 | u32 nr; |
1229 | u32 blocksize; | |
1230 | u32 nscan = 0; | |
25b8b936 | 1231 | bool map = true; |
db94535d | 1232 | |
a6b6e75e | 1233 | if (level != 1) |
6702ed49 CM |
1234 | return; |
1235 | ||
1236 | if (!path->nodes[level]) | |
3c69faec CM |
1237 | return; |
1238 | ||
5f39d397 | 1239 | node = path->nodes[level]; |
925baedd | 1240 | |
3c69faec | 1241 | search = btrfs_node_blockptr(node, slot); |
6b80053d CM |
1242 | blocksize = btrfs_level_size(root, level - 1); |
1243 | eb = btrfs_find_tree_block(root, search, blocksize); | |
5f39d397 CM |
1244 | if (eb) { |
1245 | free_extent_buffer(eb); | |
3c69faec CM |
1246 | return; |
1247 | } | |
1248 | ||
a7175319 | 1249 | target = search; |
6b80053d | 1250 | |
5f39d397 | 1251 | nritems = btrfs_header_nritems(node); |
6b80053d | 1252 | nr = slot; |
25b8b936 JB |
1253 | if (node->map_token || path->skip_locking) |
1254 | map = false; | |
1255 | ||
d397712b | 1256 | while (1) { |
25b8b936 | 1257 | if (map && !node->map_token) { |
cb25c2ea JB |
1258 | unsigned long offset = btrfs_node_key_ptr_offset(nr); |
1259 | map_private_extent_buffer(node, offset, | |
1260 | sizeof(struct btrfs_key_ptr), | |
1261 | &node->map_token, | |
1262 | &node->kaddr, | |
1263 | &node->map_start, | |
1264 | &node->map_len, KM_USER1); | |
1265 | } | |
6b80053d CM |
1266 | if (direction < 0) { |
1267 | if (nr == 0) | |
1268 | break; | |
1269 | nr--; | |
1270 | } else if (direction > 0) { | |
1271 | nr++; | |
1272 | if (nr >= nritems) | |
1273 | break; | |
3c69faec | 1274 | } |
01f46658 CM |
1275 | if (path->reada < 0 && objectid) { |
1276 | btrfs_node_key(node, &disk_key, nr); | |
1277 | if (btrfs_disk_key_objectid(&disk_key) != objectid) | |
1278 | break; | |
1279 | } | |
6b80053d | 1280 | search = btrfs_node_blockptr(node, nr); |
a7175319 CM |
1281 | if ((search <= target && target - search <= 65536) || |
1282 | (search > target && search - target <= 65536)) { | |
cb25c2ea | 1283 | gen = btrfs_node_ptr_generation(node, nr); |
25b8b936 | 1284 | if (map && node->map_token) { |
cb25c2ea JB |
1285 | unmap_extent_buffer(node, node->map_token, |
1286 | KM_USER1); | |
1287 | node->map_token = NULL; | |
1288 | } | |
1289 | readahead_tree_block(root, search, blocksize, gen); | |
6b80053d CM |
1290 | nread += blocksize; |
1291 | } | |
1292 | nscan++; | |
a7175319 | 1293 | if ((nread > 65536 || nscan > 32)) |
6b80053d | 1294 | break; |
3c69faec | 1295 | } |
25b8b936 | 1296 | if (map && node->map_token) { |
cb25c2ea JB |
1297 | unmap_extent_buffer(node, node->map_token, KM_USER1); |
1298 | node->map_token = NULL; | |
1299 | } | |
3c69faec | 1300 | } |
925baedd | 1301 | |
b4ce94de CM |
1302 | /* |
1303 | * returns -EAGAIN if it had to drop the path, or zero if everything was in | |
1304 | * cache | |
1305 | */ | |
1306 | static noinline int reada_for_balance(struct btrfs_root *root, | |
1307 | struct btrfs_path *path, int level) | |
1308 | { | |
1309 | int slot; | |
1310 | int nritems; | |
1311 | struct extent_buffer *parent; | |
1312 | struct extent_buffer *eb; | |
1313 | u64 gen; | |
1314 | u64 block1 = 0; | |
1315 | u64 block2 = 0; | |
1316 | int ret = 0; | |
1317 | int blocksize; | |
1318 | ||
8c594ea8 | 1319 | parent = path->nodes[level + 1]; |
b4ce94de CM |
1320 | if (!parent) |
1321 | return 0; | |
1322 | ||
1323 | nritems = btrfs_header_nritems(parent); | |
8c594ea8 | 1324 | slot = path->slots[level + 1]; |
b4ce94de CM |
1325 | blocksize = btrfs_level_size(root, level); |
1326 | ||
1327 | if (slot > 0) { | |
1328 | block1 = btrfs_node_blockptr(parent, slot - 1); | |
1329 | gen = btrfs_node_ptr_generation(parent, slot - 1); | |
1330 | eb = btrfs_find_tree_block(root, block1, blocksize); | |
1331 | if (eb && btrfs_buffer_uptodate(eb, gen)) | |
1332 | block1 = 0; | |
1333 | free_extent_buffer(eb); | |
1334 | } | |
8c594ea8 | 1335 | if (slot + 1 < nritems) { |
b4ce94de CM |
1336 | block2 = btrfs_node_blockptr(parent, slot + 1); |
1337 | gen = btrfs_node_ptr_generation(parent, slot + 1); | |
1338 | eb = btrfs_find_tree_block(root, block2, blocksize); | |
1339 | if (eb && btrfs_buffer_uptodate(eb, gen)) | |
1340 | block2 = 0; | |
1341 | free_extent_buffer(eb); | |
1342 | } | |
1343 | if (block1 || block2) { | |
1344 | ret = -EAGAIN; | |
8c594ea8 CM |
1345 | |
1346 | /* release the whole path */ | |
b3b4aa74 | 1347 | btrfs_release_path(path); |
8c594ea8 CM |
1348 | |
1349 | /* read the blocks */ | |
b4ce94de CM |
1350 | if (block1) |
1351 | readahead_tree_block(root, block1, blocksize, 0); | |
1352 | if (block2) | |
1353 | readahead_tree_block(root, block2, blocksize, 0); | |
1354 | ||
1355 | if (block1) { | |
1356 | eb = read_tree_block(root, block1, blocksize, 0); | |
1357 | free_extent_buffer(eb); | |
1358 | } | |
8c594ea8 | 1359 | if (block2) { |
b4ce94de CM |
1360 | eb = read_tree_block(root, block2, blocksize, 0); |
1361 | free_extent_buffer(eb); | |
1362 | } | |
1363 | } | |
1364 | return ret; | |
1365 | } | |
1366 | ||
1367 | ||
d352ac68 | 1368 | /* |
d397712b CM |
1369 | * when we walk down the tree, it is usually safe to unlock the higher layers |
1370 | * in the tree. The exceptions are when our path goes through slot 0, because | |
1371 | * operations on the tree might require changing key pointers higher up in the | |
1372 | * tree. | |
d352ac68 | 1373 | * |
d397712b CM |
1374 | * callers might also have set path->keep_locks, which tells this code to keep |
1375 | * the lock if the path points to the last slot in the block. This is part of | |
1376 | * walking through the tree, and selecting the next slot in the higher block. | |
d352ac68 | 1377 | * |
d397712b CM |
1378 | * lowest_unlock sets the lowest level in the tree we're allowed to unlock. so |
1379 | * if lowest_unlock is 1, level 0 won't be unlocked | |
d352ac68 | 1380 | */ |
e02119d5 CM |
1381 | static noinline void unlock_up(struct btrfs_path *path, int level, |
1382 | int lowest_unlock) | |
925baedd CM |
1383 | { |
1384 | int i; | |
1385 | int skip_level = level; | |
051e1b9f | 1386 | int no_skips = 0; |
925baedd CM |
1387 | struct extent_buffer *t; |
1388 | ||
1389 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { | |
1390 | if (!path->nodes[i]) | |
1391 | break; | |
1392 | if (!path->locks[i]) | |
1393 | break; | |
051e1b9f | 1394 | if (!no_skips && path->slots[i] == 0) { |
925baedd CM |
1395 | skip_level = i + 1; |
1396 | continue; | |
1397 | } | |
051e1b9f | 1398 | if (!no_skips && path->keep_locks) { |
925baedd CM |
1399 | u32 nritems; |
1400 | t = path->nodes[i]; | |
1401 | nritems = btrfs_header_nritems(t); | |
051e1b9f | 1402 | if (nritems < 1 || path->slots[i] >= nritems - 1) { |
925baedd CM |
1403 | skip_level = i + 1; |
1404 | continue; | |
1405 | } | |
1406 | } | |
051e1b9f CM |
1407 | if (skip_level < i && i >= lowest_unlock) |
1408 | no_skips = 1; | |
1409 | ||
925baedd CM |
1410 | t = path->nodes[i]; |
1411 | if (i >= lowest_unlock && i > skip_level && path->locks[i]) { | |
1412 | btrfs_tree_unlock(t); | |
1413 | path->locks[i] = 0; | |
1414 | } | |
1415 | } | |
1416 | } | |
1417 | ||
b4ce94de CM |
1418 | /* |
1419 | * This releases any locks held in the path starting at level and | |
1420 | * going all the way up to the root. | |
1421 | * | |
1422 | * btrfs_search_slot will keep the lock held on higher nodes in a few | |
1423 | * corner cases, such as COW of the block at slot zero in the node. This | |
1424 | * ignores those rules, and it should only be called when there are no | |
1425 | * more updates to be done higher up in the tree. | |
1426 | */ | |
1427 | noinline void btrfs_unlock_up_safe(struct btrfs_path *path, int level) | |
1428 | { | |
1429 | int i; | |
1430 | ||
5d4f98a2 | 1431 | if (path->keep_locks) |
b4ce94de CM |
1432 | return; |
1433 | ||
1434 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { | |
1435 | if (!path->nodes[i]) | |
12f4dacc | 1436 | continue; |
b4ce94de | 1437 | if (!path->locks[i]) |
12f4dacc | 1438 | continue; |
b4ce94de CM |
1439 | btrfs_tree_unlock(path->nodes[i]); |
1440 | path->locks[i] = 0; | |
1441 | } | |
1442 | } | |
1443 | ||
c8c42864 CM |
1444 | /* |
1445 | * helper function for btrfs_search_slot. The goal is to find a block | |
1446 | * in cache without setting the path to blocking. If we find the block | |
1447 | * we return zero and the path is unchanged. | |
1448 | * | |
1449 | * If we can't find the block, we set the path blocking and do some | |
1450 | * reada. -EAGAIN is returned and the search must be repeated. | |
1451 | */ | |
1452 | static int | |
1453 | read_block_for_search(struct btrfs_trans_handle *trans, | |
1454 | struct btrfs_root *root, struct btrfs_path *p, | |
1455 | struct extent_buffer **eb_ret, int level, int slot, | |
1456 | struct btrfs_key *key) | |
1457 | { | |
1458 | u64 blocknr; | |
1459 | u64 gen; | |
1460 | u32 blocksize; | |
1461 | struct extent_buffer *b = *eb_ret; | |
1462 | struct extent_buffer *tmp; | |
76a05b35 | 1463 | int ret; |
c8c42864 CM |
1464 | |
1465 | blocknr = btrfs_node_blockptr(b, slot); | |
1466 | gen = btrfs_node_ptr_generation(b, slot); | |
1467 | blocksize = btrfs_level_size(root, level - 1); | |
1468 | ||
1469 | tmp = btrfs_find_tree_block(root, blocknr, blocksize); | |
cb44921a CM |
1470 | if (tmp) { |
1471 | if (btrfs_buffer_uptodate(tmp, 0)) { | |
1472 | if (btrfs_buffer_uptodate(tmp, gen)) { | |
1473 | /* | |
1474 | * we found an up to date block without | |
1475 | * sleeping, return | |
1476 | * right away | |
1477 | */ | |
1478 | *eb_ret = tmp; | |
1479 | return 0; | |
1480 | } | |
1481 | /* the pages were up to date, but we failed | |
1482 | * the generation number check. Do a full | |
1483 | * read for the generation number that is correct. | |
1484 | * We must do this without dropping locks so | |
1485 | * we can trust our generation number | |
1486 | */ | |
1487 | free_extent_buffer(tmp); | |
1488 | tmp = read_tree_block(root, blocknr, blocksize, gen); | |
1489 | if (tmp && btrfs_buffer_uptodate(tmp, gen)) { | |
1490 | *eb_ret = tmp; | |
1491 | return 0; | |
1492 | } | |
1493 | free_extent_buffer(tmp); | |
b3b4aa74 | 1494 | btrfs_release_path(p); |
cb44921a CM |
1495 | return -EIO; |
1496 | } | |
c8c42864 CM |
1497 | } |
1498 | ||
1499 | /* | |
1500 | * reduce lock contention at high levels | |
1501 | * of the btree by dropping locks before | |
76a05b35 CM |
1502 | * we read. Don't release the lock on the current |
1503 | * level because we need to walk this node to figure | |
1504 | * out which blocks to read. | |
c8c42864 | 1505 | */ |
8c594ea8 CM |
1506 | btrfs_unlock_up_safe(p, level + 1); |
1507 | btrfs_set_path_blocking(p); | |
1508 | ||
cb44921a | 1509 | free_extent_buffer(tmp); |
c8c42864 CM |
1510 | if (p->reada) |
1511 | reada_for_search(root, p, level, slot, key->objectid); | |
1512 | ||
b3b4aa74 | 1513 | btrfs_release_path(p); |
76a05b35 CM |
1514 | |
1515 | ret = -EAGAIN; | |
5bdd3536 | 1516 | tmp = read_tree_block(root, blocknr, blocksize, 0); |
76a05b35 CM |
1517 | if (tmp) { |
1518 | /* | |
1519 | * If the read above didn't mark this buffer up to date, | |
1520 | * it will never end up being up to date. Set ret to EIO now | |
1521 | * and give up so that our caller doesn't loop forever | |
1522 | * on our EAGAINs. | |
1523 | */ | |
1524 | if (!btrfs_buffer_uptodate(tmp, 0)) | |
1525 | ret = -EIO; | |
c8c42864 | 1526 | free_extent_buffer(tmp); |
76a05b35 CM |
1527 | } |
1528 | return ret; | |
c8c42864 CM |
1529 | } |
1530 | ||
1531 | /* | |
1532 | * helper function for btrfs_search_slot. This does all of the checks | |
1533 | * for node-level blocks and does any balancing required based on | |
1534 | * the ins_len. | |
1535 | * | |
1536 | * If no extra work was required, zero is returned. If we had to | |
1537 | * drop the path, -EAGAIN is returned and btrfs_search_slot must | |
1538 | * start over | |
1539 | */ | |
1540 | static int | |
1541 | setup_nodes_for_search(struct btrfs_trans_handle *trans, | |
1542 | struct btrfs_root *root, struct btrfs_path *p, | |
1543 | struct extent_buffer *b, int level, int ins_len) | |
1544 | { | |
1545 | int ret; | |
1546 | if ((p->search_for_split || ins_len > 0) && btrfs_header_nritems(b) >= | |
1547 | BTRFS_NODEPTRS_PER_BLOCK(root) - 3) { | |
1548 | int sret; | |
1549 | ||
1550 | sret = reada_for_balance(root, p, level); | |
1551 | if (sret) | |
1552 | goto again; | |
1553 | ||
1554 | btrfs_set_path_blocking(p); | |
1555 | sret = split_node(trans, root, p, level); | |
1556 | btrfs_clear_path_blocking(p, NULL); | |
1557 | ||
1558 | BUG_ON(sret > 0); | |
1559 | if (sret) { | |
1560 | ret = sret; | |
1561 | goto done; | |
1562 | } | |
1563 | b = p->nodes[level]; | |
1564 | } else if (ins_len < 0 && btrfs_header_nritems(b) < | |
cfbb9308 | 1565 | BTRFS_NODEPTRS_PER_BLOCK(root) / 2) { |
c8c42864 CM |
1566 | int sret; |
1567 | ||
1568 | sret = reada_for_balance(root, p, level); | |
1569 | if (sret) | |
1570 | goto again; | |
1571 | ||
1572 | btrfs_set_path_blocking(p); | |
1573 | sret = balance_level(trans, root, p, level); | |
1574 | btrfs_clear_path_blocking(p, NULL); | |
1575 | ||
1576 | if (sret) { | |
1577 | ret = sret; | |
1578 | goto done; | |
1579 | } | |
1580 | b = p->nodes[level]; | |
1581 | if (!b) { | |
b3b4aa74 | 1582 | btrfs_release_path(p); |
c8c42864 CM |
1583 | goto again; |
1584 | } | |
1585 | BUG_ON(btrfs_header_nritems(b) == 1); | |
1586 | } | |
1587 | return 0; | |
1588 | ||
1589 | again: | |
1590 | ret = -EAGAIN; | |
1591 | done: | |
1592 | return ret; | |
1593 | } | |
1594 | ||
74123bd7 CM |
1595 | /* |
1596 | * look for key in the tree. path is filled in with nodes along the way | |
1597 | * if key is found, we return zero and you can find the item in the leaf | |
1598 | * level of the path (level 0) | |
1599 | * | |
1600 | * If the key isn't found, the path points to the slot where it should | |
aa5d6bed CM |
1601 | * be inserted, and 1 is returned. If there are other errors during the |
1602 | * search a negative error number is returned. | |
97571fd0 CM |
1603 | * |
1604 | * if ins_len > 0, nodes and leaves will be split as we walk down the | |
1605 | * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if | |
1606 | * possible) | |
74123bd7 | 1607 | */ |
e089f05c CM |
1608 | int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root |
1609 | *root, struct btrfs_key *key, struct btrfs_path *p, int | |
1610 | ins_len, int cow) | |
be0e5c09 | 1611 | { |
5f39d397 | 1612 | struct extent_buffer *b; |
be0e5c09 CM |
1613 | int slot; |
1614 | int ret; | |
33c66f43 | 1615 | int err; |
be0e5c09 | 1616 | int level; |
925baedd | 1617 | int lowest_unlock = 1; |
9f3a7427 CM |
1618 | u8 lowest_level = 0; |
1619 | ||
6702ed49 | 1620 | lowest_level = p->lowest_level; |
323ac95b | 1621 | WARN_ON(lowest_level && ins_len > 0); |
22b0ebda | 1622 | WARN_ON(p->nodes[0] != NULL); |
25179201 | 1623 | |
925baedd CM |
1624 | if (ins_len < 0) |
1625 | lowest_unlock = 2; | |
65b51a00 | 1626 | |
bb803951 | 1627 | again: |
5d4f98a2 YZ |
1628 | if (p->search_commit_root) { |
1629 | b = root->commit_root; | |
1630 | extent_buffer_get(b); | |
1631 | if (!p->skip_locking) | |
1632 | btrfs_tree_lock(b); | |
1633 | } else { | |
1634 | if (p->skip_locking) | |
1635 | b = btrfs_root_node(root); | |
1636 | else | |
1637 | b = btrfs_lock_root_node(root); | |
1638 | } | |
925baedd | 1639 | |
eb60ceac | 1640 | while (b) { |
5f39d397 | 1641 | level = btrfs_header_level(b); |
65b51a00 CM |
1642 | |
1643 | /* | |
1644 | * setup the path here so we can release it under lock | |
1645 | * contention with the cow code | |
1646 | */ | |
1647 | p->nodes[level] = b; | |
1648 | if (!p->skip_locking) | |
1649 | p->locks[level] = 1; | |
1650 | ||
02217ed2 | 1651 | if (cow) { |
c8c42864 CM |
1652 | /* |
1653 | * if we don't really need to cow this block | |
1654 | * then we don't want to set the path blocking, | |
1655 | * so we test it here | |
1656 | */ | |
5d4f98a2 | 1657 | if (!should_cow_block(trans, root, b)) |
65b51a00 | 1658 | goto cow_done; |
5d4f98a2 | 1659 | |
b4ce94de CM |
1660 | btrfs_set_path_blocking(p); |
1661 | ||
33c66f43 YZ |
1662 | err = btrfs_cow_block(trans, root, b, |
1663 | p->nodes[level + 1], | |
1664 | p->slots[level + 1], &b); | |
1665 | if (err) { | |
33c66f43 | 1666 | ret = err; |
65b51a00 | 1667 | goto done; |
54aa1f4d | 1668 | } |
02217ed2 | 1669 | } |
65b51a00 | 1670 | cow_done: |
02217ed2 | 1671 | BUG_ON(!cow && ins_len); |
65b51a00 | 1672 | |
eb60ceac | 1673 | p->nodes[level] = b; |
5cd57b2c CM |
1674 | if (!p->skip_locking) |
1675 | p->locks[level] = 1; | |
65b51a00 | 1676 | |
4008c04a | 1677 | btrfs_clear_path_blocking(p, NULL); |
b4ce94de CM |
1678 | |
1679 | /* | |
1680 | * we have a lock on b and as long as we aren't changing | |
1681 | * the tree, there is no way to for the items in b to change. | |
1682 | * It is safe to drop the lock on our parent before we | |
1683 | * go through the expensive btree search on b. | |
1684 | * | |
1685 | * If cow is true, then we might be changing slot zero, | |
1686 | * which may require changing the parent. So, we can't | |
1687 | * drop the lock until after we know which slot we're | |
1688 | * operating on. | |
1689 | */ | |
1690 | if (!cow) | |
1691 | btrfs_unlock_up_safe(p, level + 1); | |
1692 | ||
5f39d397 | 1693 | ret = bin_search(b, key, level, &slot); |
b4ce94de | 1694 | |
5f39d397 | 1695 | if (level != 0) { |
33c66f43 YZ |
1696 | int dec = 0; |
1697 | if (ret && slot > 0) { | |
1698 | dec = 1; | |
be0e5c09 | 1699 | slot -= 1; |
33c66f43 | 1700 | } |
be0e5c09 | 1701 | p->slots[level] = slot; |
33c66f43 | 1702 | err = setup_nodes_for_search(trans, root, p, b, level, |
c8c42864 | 1703 | ins_len); |
33c66f43 | 1704 | if (err == -EAGAIN) |
c8c42864 | 1705 | goto again; |
33c66f43 YZ |
1706 | if (err) { |
1707 | ret = err; | |
c8c42864 | 1708 | goto done; |
33c66f43 | 1709 | } |
c8c42864 CM |
1710 | b = p->nodes[level]; |
1711 | slot = p->slots[level]; | |
b4ce94de | 1712 | |
f9efa9c7 CM |
1713 | unlock_up(p, level, lowest_unlock); |
1714 | ||
925baedd | 1715 | if (level == lowest_level) { |
33c66f43 YZ |
1716 | if (dec) |
1717 | p->slots[level]++; | |
5b21f2ed | 1718 | goto done; |
925baedd | 1719 | } |
ca7a79ad | 1720 | |
33c66f43 | 1721 | err = read_block_for_search(trans, root, p, |
c8c42864 | 1722 | &b, level, slot, key); |
33c66f43 | 1723 | if (err == -EAGAIN) |
c8c42864 | 1724 | goto again; |
33c66f43 YZ |
1725 | if (err) { |
1726 | ret = err; | |
76a05b35 | 1727 | goto done; |
33c66f43 | 1728 | } |
76a05b35 | 1729 | |
b4ce94de | 1730 | if (!p->skip_locking) { |
4008c04a | 1731 | btrfs_clear_path_blocking(p, NULL); |
33c66f43 | 1732 | err = btrfs_try_spin_lock(b); |
b4ce94de | 1733 | |
33c66f43 | 1734 | if (!err) { |
b4ce94de CM |
1735 | btrfs_set_path_blocking(p); |
1736 | btrfs_tree_lock(b); | |
4008c04a | 1737 | btrfs_clear_path_blocking(p, b); |
b4ce94de CM |
1738 | } |
1739 | } | |
be0e5c09 CM |
1740 | } else { |
1741 | p->slots[level] = slot; | |
87b29b20 YZ |
1742 | if (ins_len > 0 && |
1743 | btrfs_leaf_free_space(root, b) < ins_len) { | |
b4ce94de | 1744 | btrfs_set_path_blocking(p); |
33c66f43 YZ |
1745 | err = split_leaf(trans, root, key, |
1746 | p, ins_len, ret == 0); | |
4008c04a | 1747 | btrfs_clear_path_blocking(p, NULL); |
b4ce94de | 1748 | |
33c66f43 YZ |
1749 | BUG_ON(err > 0); |
1750 | if (err) { | |
1751 | ret = err; | |
65b51a00 CM |
1752 | goto done; |
1753 | } | |
5c680ed6 | 1754 | } |
459931ec CM |
1755 | if (!p->search_for_split) |
1756 | unlock_up(p, level, lowest_unlock); | |
65b51a00 | 1757 | goto done; |
be0e5c09 CM |
1758 | } |
1759 | } | |
65b51a00 CM |
1760 | ret = 1; |
1761 | done: | |
b4ce94de CM |
1762 | /* |
1763 | * we don't really know what they plan on doing with the path | |
1764 | * from here on, so for now just mark it as blocking | |
1765 | */ | |
b9473439 CM |
1766 | if (!p->leave_spinning) |
1767 | btrfs_set_path_blocking(p); | |
76a05b35 | 1768 | if (ret < 0) |
b3b4aa74 | 1769 | btrfs_release_path(p); |
65b51a00 | 1770 | return ret; |
be0e5c09 CM |
1771 | } |
1772 | ||
74123bd7 CM |
1773 | /* |
1774 | * adjust the pointers going up the tree, starting at level | |
1775 | * making sure the right key of each node is points to 'key'. | |
1776 | * This is used after shifting pointers to the left, so it stops | |
1777 | * fixing up pointers when a given leaf/node is not in slot 0 of the | |
1778 | * higher levels | |
aa5d6bed CM |
1779 | * |
1780 | * If this fails to write a tree block, it returns -1, but continues | |
1781 | * fixing up the blocks in ram so the tree is consistent. | |
74123bd7 | 1782 | */ |
5f39d397 CM |
1783 | static int fixup_low_keys(struct btrfs_trans_handle *trans, |
1784 | struct btrfs_root *root, struct btrfs_path *path, | |
1785 | struct btrfs_disk_key *key, int level) | |
be0e5c09 CM |
1786 | { |
1787 | int i; | |
aa5d6bed | 1788 | int ret = 0; |
5f39d397 CM |
1789 | struct extent_buffer *t; |
1790 | ||
234b63a0 | 1791 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { |
be0e5c09 | 1792 | int tslot = path->slots[i]; |
eb60ceac | 1793 | if (!path->nodes[i]) |
be0e5c09 | 1794 | break; |
5f39d397 CM |
1795 | t = path->nodes[i]; |
1796 | btrfs_set_node_key(t, key, tslot); | |
d6025579 | 1797 | btrfs_mark_buffer_dirty(path->nodes[i]); |
be0e5c09 CM |
1798 | if (tslot != 0) |
1799 | break; | |
1800 | } | |
aa5d6bed | 1801 | return ret; |
be0e5c09 CM |
1802 | } |
1803 | ||
31840ae1 ZY |
1804 | /* |
1805 | * update item key. | |
1806 | * | |
1807 | * This function isn't completely safe. It's the caller's responsibility | |
1808 | * that the new key won't break the order | |
1809 | */ | |
1810 | int btrfs_set_item_key_safe(struct btrfs_trans_handle *trans, | |
1811 | struct btrfs_root *root, struct btrfs_path *path, | |
1812 | struct btrfs_key *new_key) | |
1813 | { | |
1814 | struct btrfs_disk_key disk_key; | |
1815 | struct extent_buffer *eb; | |
1816 | int slot; | |
1817 | ||
1818 | eb = path->nodes[0]; | |
1819 | slot = path->slots[0]; | |
1820 | if (slot > 0) { | |
1821 | btrfs_item_key(eb, &disk_key, slot - 1); | |
1822 | if (comp_keys(&disk_key, new_key) >= 0) | |
1823 | return -1; | |
1824 | } | |
1825 | if (slot < btrfs_header_nritems(eb) - 1) { | |
1826 | btrfs_item_key(eb, &disk_key, slot + 1); | |
1827 | if (comp_keys(&disk_key, new_key) <= 0) | |
1828 | return -1; | |
1829 | } | |
1830 | ||
1831 | btrfs_cpu_key_to_disk(&disk_key, new_key); | |
1832 | btrfs_set_item_key(eb, &disk_key, slot); | |
1833 | btrfs_mark_buffer_dirty(eb); | |
1834 | if (slot == 0) | |
1835 | fixup_low_keys(trans, root, path, &disk_key, 1); | |
1836 | return 0; | |
1837 | } | |
1838 | ||
74123bd7 CM |
1839 | /* |
1840 | * try to push data from one node into the next node left in the | |
79f95c82 | 1841 | * tree. |
aa5d6bed CM |
1842 | * |
1843 | * returns 0 if some ptrs were pushed left, < 0 if there was some horrible | |
1844 | * error, and > 0 if there was no room in the left hand block. | |
74123bd7 | 1845 | */ |
98ed5174 CM |
1846 | static int push_node_left(struct btrfs_trans_handle *trans, |
1847 | struct btrfs_root *root, struct extent_buffer *dst, | |
971a1f66 | 1848 | struct extent_buffer *src, int empty) |
be0e5c09 | 1849 | { |
be0e5c09 | 1850 | int push_items = 0; |
bb803951 CM |
1851 | int src_nritems; |
1852 | int dst_nritems; | |
aa5d6bed | 1853 | int ret = 0; |
be0e5c09 | 1854 | |
5f39d397 CM |
1855 | src_nritems = btrfs_header_nritems(src); |
1856 | dst_nritems = btrfs_header_nritems(dst); | |
123abc88 | 1857 | push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems; |
7bb86316 CM |
1858 | WARN_ON(btrfs_header_generation(src) != trans->transid); |
1859 | WARN_ON(btrfs_header_generation(dst) != trans->transid); | |
54aa1f4d | 1860 | |
bce4eae9 | 1861 | if (!empty && src_nritems <= 8) |
971a1f66 CM |
1862 | return 1; |
1863 | ||
d397712b | 1864 | if (push_items <= 0) |
be0e5c09 CM |
1865 | return 1; |
1866 | ||
bce4eae9 | 1867 | if (empty) { |
971a1f66 | 1868 | push_items = min(src_nritems, push_items); |
bce4eae9 CM |
1869 | if (push_items < src_nritems) { |
1870 | /* leave at least 8 pointers in the node if | |
1871 | * we aren't going to empty it | |
1872 | */ | |
1873 | if (src_nritems - push_items < 8) { | |
1874 | if (push_items <= 8) | |
1875 | return 1; | |
1876 | push_items -= 8; | |
1877 | } | |
1878 | } | |
1879 | } else | |
1880 | push_items = min(src_nritems - 8, push_items); | |
79f95c82 | 1881 | |
5f39d397 CM |
1882 | copy_extent_buffer(dst, src, |
1883 | btrfs_node_key_ptr_offset(dst_nritems), | |
1884 | btrfs_node_key_ptr_offset(0), | |
d397712b | 1885 | push_items * sizeof(struct btrfs_key_ptr)); |
5f39d397 | 1886 | |
bb803951 | 1887 | if (push_items < src_nritems) { |
5f39d397 CM |
1888 | memmove_extent_buffer(src, btrfs_node_key_ptr_offset(0), |
1889 | btrfs_node_key_ptr_offset(push_items), | |
1890 | (src_nritems - push_items) * | |
1891 | sizeof(struct btrfs_key_ptr)); | |
1892 | } | |
1893 | btrfs_set_header_nritems(src, src_nritems - push_items); | |
1894 | btrfs_set_header_nritems(dst, dst_nritems + push_items); | |
1895 | btrfs_mark_buffer_dirty(src); | |
1896 | btrfs_mark_buffer_dirty(dst); | |
31840ae1 | 1897 | |
79f95c82 CM |
1898 | return ret; |
1899 | } | |
1900 | ||
1901 | /* | |
1902 | * try to push data from one node into the next node right in the | |
1903 | * tree. | |
1904 | * | |
1905 | * returns 0 if some ptrs were pushed, < 0 if there was some horrible | |
1906 | * error, and > 0 if there was no room in the right hand block. | |
1907 | * | |
1908 | * this will only push up to 1/2 the contents of the left node over | |
1909 | */ | |
5f39d397 CM |
1910 | static int balance_node_right(struct btrfs_trans_handle *trans, |
1911 | struct btrfs_root *root, | |
1912 | struct extent_buffer *dst, | |
1913 | struct extent_buffer *src) | |
79f95c82 | 1914 | { |
79f95c82 CM |
1915 | int push_items = 0; |
1916 | int max_push; | |
1917 | int src_nritems; | |
1918 | int dst_nritems; | |
1919 | int ret = 0; | |
79f95c82 | 1920 | |
7bb86316 CM |
1921 | WARN_ON(btrfs_header_generation(src) != trans->transid); |
1922 | WARN_ON(btrfs_header_generation(dst) != trans->transid); | |
1923 | ||
5f39d397 CM |
1924 | src_nritems = btrfs_header_nritems(src); |
1925 | dst_nritems = btrfs_header_nritems(dst); | |
123abc88 | 1926 | push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems; |
d397712b | 1927 | if (push_items <= 0) |
79f95c82 | 1928 | return 1; |
bce4eae9 | 1929 | |
d397712b | 1930 | if (src_nritems < 4) |
bce4eae9 | 1931 | return 1; |
79f95c82 CM |
1932 | |
1933 | max_push = src_nritems / 2 + 1; | |
1934 | /* don't try to empty the node */ | |
d397712b | 1935 | if (max_push >= src_nritems) |
79f95c82 | 1936 | return 1; |
252c38f0 | 1937 | |
79f95c82 CM |
1938 | if (max_push < push_items) |
1939 | push_items = max_push; | |
1940 | ||
5f39d397 CM |
1941 | memmove_extent_buffer(dst, btrfs_node_key_ptr_offset(push_items), |
1942 | btrfs_node_key_ptr_offset(0), | |
1943 | (dst_nritems) * | |
1944 | sizeof(struct btrfs_key_ptr)); | |
d6025579 | 1945 | |
5f39d397 CM |
1946 | copy_extent_buffer(dst, src, |
1947 | btrfs_node_key_ptr_offset(0), | |
1948 | btrfs_node_key_ptr_offset(src_nritems - push_items), | |
d397712b | 1949 | push_items * sizeof(struct btrfs_key_ptr)); |
79f95c82 | 1950 | |
5f39d397 CM |
1951 | btrfs_set_header_nritems(src, src_nritems - push_items); |
1952 | btrfs_set_header_nritems(dst, dst_nritems + push_items); | |
79f95c82 | 1953 | |
5f39d397 CM |
1954 | btrfs_mark_buffer_dirty(src); |
1955 | btrfs_mark_buffer_dirty(dst); | |
31840ae1 | 1956 | |
aa5d6bed | 1957 | return ret; |
be0e5c09 CM |
1958 | } |
1959 | ||
97571fd0 CM |
1960 | /* |
1961 | * helper function to insert a new root level in the tree. | |
1962 | * A new node is allocated, and a single item is inserted to | |
1963 | * point to the existing root | |
aa5d6bed CM |
1964 | * |
1965 | * returns zero on success or < 0 on failure. | |
97571fd0 | 1966 | */ |
d397712b | 1967 | static noinline int insert_new_root(struct btrfs_trans_handle *trans, |
5f39d397 CM |
1968 | struct btrfs_root *root, |
1969 | struct btrfs_path *path, int level) | |
5c680ed6 | 1970 | { |
7bb86316 | 1971 | u64 lower_gen; |
5f39d397 CM |
1972 | struct extent_buffer *lower; |
1973 | struct extent_buffer *c; | |
925baedd | 1974 | struct extent_buffer *old; |
5f39d397 | 1975 | struct btrfs_disk_key lower_key; |
5c680ed6 CM |
1976 | |
1977 | BUG_ON(path->nodes[level]); | |
1978 | BUG_ON(path->nodes[level-1] != root->node); | |
1979 | ||
7bb86316 CM |
1980 | lower = path->nodes[level-1]; |
1981 | if (level == 1) | |
1982 | btrfs_item_key(lower, &lower_key, 0); | |
1983 | else | |
1984 | btrfs_node_key(lower, &lower_key, 0); | |
1985 | ||
31840ae1 | 1986 | c = btrfs_alloc_free_block(trans, root, root->nodesize, 0, |
5d4f98a2 | 1987 | root->root_key.objectid, &lower_key, |
ad3d81ba | 1988 | level, root->node->start, 0); |
5f39d397 CM |
1989 | if (IS_ERR(c)) |
1990 | return PTR_ERR(c); | |
925baedd | 1991 | |
f0486c68 YZ |
1992 | root_add_used(root, root->nodesize); |
1993 | ||
5d4f98a2 | 1994 | memset_extent_buffer(c, 0, 0, sizeof(struct btrfs_header)); |
5f39d397 CM |
1995 | btrfs_set_header_nritems(c, 1); |
1996 | btrfs_set_header_level(c, level); | |
db94535d | 1997 | btrfs_set_header_bytenr(c, c->start); |
5f39d397 | 1998 | btrfs_set_header_generation(c, trans->transid); |
5d4f98a2 | 1999 | btrfs_set_header_backref_rev(c, BTRFS_MIXED_BACKREF_REV); |
5f39d397 | 2000 | btrfs_set_header_owner(c, root->root_key.objectid); |
5f39d397 CM |
2001 | |
2002 | write_extent_buffer(c, root->fs_info->fsid, | |
2003 | (unsigned long)btrfs_header_fsid(c), | |
2004 | BTRFS_FSID_SIZE); | |
e17cade2 CM |
2005 | |
2006 | write_extent_buffer(c, root->fs_info->chunk_tree_uuid, | |
2007 | (unsigned long)btrfs_header_chunk_tree_uuid(c), | |
2008 | BTRFS_UUID_SIZE); | |
2009 | ||
5f39d397 | 2010 | btrfs_set_node_key(c, &lower_key, 0); |
db94535d | 2011 | btrfs_set_node_blockptr(c, 0, lower->start); |
7bb86316 | 2012 | lower_gen = btrfs_header_generation(lower); |
31840ae1 | 2013 | WARN_ON(lower_gen != trans->transid); |
7bb86316 CM |
2014 | |
2015 | btrfs_set_node_ptr_generation(c, 0, lower_gen); | |
d5719762 | 2016 | |
5f39d397 | 2017 | btrfs_mark_buffer_dirty(c); |
d5719762 | 2018 | |
925baedd | 2019 | old = root->node; |
240f62c8 | 2020 | rcu_assign_pointer(root->node, c); |
925baedd CM |
2021 | |
2022 | /* the super has an extra ref to root->node */ | |
2023 | free_extent_buffer(old); | |
2024 | ||
0b86a832 | 2025 | add_root_to_dirty_list(root); |
5f39d397 CM |
2026 | extent_buffer_get(c); |
2027 | path->nodes[level] = c; | |
925baedd | 2028 | path->locks[level] = 1; |
5c680ed6 CM |
2029 | path->slots[level] = 0; |
2030 | return 0; | |
2031 | } | |
2032 | ||
74123bd7 CM |
2033 | /* |
2034 | * worker function to insert a single pointer in a node. | |
2035 | * the node should have enough room for the pointer already | |
97571fd0 | 2036 | * |
74123bd7 CM |
2037 | * slot and level indicate where you want the key to go, and |
2038 | * blocknr is the block the key points to. | |
aa5d6bed CM |
2039 | * |
2040 | * returns zero on success and < 0 on any error | |
74123bd7 | 2041 | */ |
e089f05c CM |
2042 | static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root |
2043 | *root, struct btrfs_path *path, struct btrfs_disk_key | |
db94535d | 2044 | *key, u64 bytenr, int slot, int level) |
74123bd7 | 2045 | { |
5f39d397 | 2046 | struct extent_buffer *lower; |
74123bd7 | 2047 | int nritems; |
5c680ed6 CM |
2048 | |
2049 | BUG_ON(!path->nodes[level]); | |
f0486c68 | 2050 | btrfs_assert_tree_locked(path->nodes[level]); |
5f39d397 CM |
2051 | lower = path->nodes[level]; |
2052 | nritems = btrfs_header_nritems(lower); | |
c293498b | 2053 | BUG_ON(slot > nritems); |
123abc88 | 2054 | if (nritems == BTRFS_NODEPTRS_PER_BLOCK(root)) |
74123bd7 CM |
2055 | BUG(); |
2056 | if (slot != nritems) { | |
5f39d397 CM |
2057 | memmove_extent_buffer(lower, |
2058 | btrfs_node_key_ptr_offset(slot + 1), | |
2059 | btrfs_node_key_ptr_offset(slot), | |
d6025579 | 2060 | (nritems - slot) * sizeof(struct btrfs_key_ptr)); |
74123bd7 | 2061 | } |
5f39d397 | 2062 | btrfs_set_node_key(lower, key, slot); |
db94535d | 2063 | btrfs_set_node_blockptr(lower, slot, bytenr); |
74493f7a CM |
2064 | WARN_ON(trans->transid == 0); |
2065 | btrfs_set_node_ptr_generation(lower, slot, trans->transid); | |
5f39d397 CM |
2066 | btrfs_set_header_nritems(lower, nritems + 1); |
2067 | btrfs_mark_buffer_dirty(lower); | |
74123bd7 CM |
2068 | return 0; |
2069 | } | |
2070 | ||
97571fd0 CM |
2071 | /* |
2072 | * split the node at the specified level in path in two. | |
2073 | * The path is corrected to point to the appropriate node after the split | |
2074 | * | |
2075 | * Before splitting this tries to make some room in the node by pushing | |
2076 | * left and right, if either one works, it returns right away. | |
aa5d6bed CM |
2077 | * |
2078 | * returns 0 on success and < 0 on failure | |
97571fd0 | 2079 | */ |
e02119d5 CM |
2080 | static noinline int split_node(struct btrfs_trans_handle *trans, |
2081 | struct btrfs_root *root, | |
2082 | struct btrfs_path *path, int level) | |
be0e5c09 | 2083 | { |
5f39d397 CM |
2084 | struct extent_buffer *c; |
2085 | struct extent_buffer *split; | |
2086 | struct btrfs_disk_key disk_key; | |
be0e5c09 | 2087 | int mid; |
5c680ed6 | 2088 | int ret; |
aa5d6bed | 2089 | int wret; |
7518a238 | 2090 | u32 c_nritems; |
eb60ceac | 2091 | |
5f39d397 | 2092 | c = path->nodes[level]; |
7bb86316 | 2093 | WARN_ON(btrfs_header_generation(c) != trans->transid); |
5f39d397 | 2094 | if (c == root->node) { |
5c680ed6 | 2095 | /* trying to split the root, lets make a new one */ |
e089f05c | 2096 | ret = insert_new_root(trans, root, path, level + 1); |
5c680ed6 CM |
2097 | if (ret) |
2098 | return ret; | |
b3612421 | 2099 | } else { |
e66f709b | 2100 | ret = push_nodes_for_insert(trans, root, path, level); |
5f39d397 CM |
2101 | c = path->nodes[level]; |
2102 | if (!ret && btrfs_header_nritems(c) < | |
c448acf0 | 2103 | BTRFS_NODEPTRS_PER_BLOCK(root) - 3) |
e66f709b | 2104 | return 0; |
54aa1f4d CM |
2105 | if (ret < 0) |
2106 | return ret; | |
be0e5c09 | 2107 | } |
e66f709b | 2108 | |
5f39d397 | 2109 | c_nritems = btrfs_header_nritems(c); |
5d4f98a2 YZ |
2110 | mid = (c_nritems + 1) / 2; |
2111 | btrfs_node_key(c, &disk_key, mid); | |
7bb86316 | 2112 | |
5d4f98a2 | 2113 | split = btrfs_alloc_free_block(trans, root, root->nodesize, 0, |
31840ae1 | 2114 | root->root_key.objectid, |
5d4f98a2 | 2115 | &disk_key, level, c->start, 0); |
5f39d397 CM |
2116 | if (IS_ERR(split)) |
2117 | return PTR_ERR(split); | |
2118 | ||
f0486c68 YZ |
2119 | root_add_used(root, root->nodesize); |
2120 | ||
5d4f98a2 | 2121 | memset_extent_buffer(split, 0, 0, sizeof(struct btrfs_header)); |
5f39d397 | 2122 | btrfs_set_header_level(split, btrfs_header_level(c)); |
db94535d | 2123 | btrfs_set_header_bytenr(split, split->start); |
5f39d397 | 2124 | btrfs_set_header_generation(split, trans->transid); |
5d4f98a2 | 2125 | btrfs_set_header_backref_rev(split, BTRFS_MIXED_BACKREF_REV); |
5f39d397 CM |
2126 | btrfs_set_header_owner(split, root->root_key.objectid); |
2127 | write_extent_buffer(split, root->fs_info->fsid, | |
2128 | (unsigned long)btrfs_header_fsid(split), | |
2129 | BTRFS_FSID_SIZE); | |
e17cade2 CM |
2130 | write_extent_buffer(split, root->fs_info->chunk_tree_uuid, |
2131 | (unsigned long)btrfs_header_chunk_tree_uuid(split), | |
2132 | BTRFS_UUID_SIZE); | |
54aa1f4d | 2133 | |
5f39d397 CM |
2134 | |
2135 | copy_extent_buffer(split, c, | |
2136 | btrfs_node_key_ptr_offset(0), | |
2137 | btrfs_node_key_ptr_offset(mid), | |
2138 | (c_nritems - mid) * sizeof(struct btrfs_key_ptr)); | |
2139 | btrfs_set_header_nritems(split, c_nritems - mid); | |
2140 | btrfs_set_header_nritems(c, mid); | |
aa5d6bed CM |
2141 | ret = 0; |
2142 | ||
5f39d397 CM |
2143 | btrfs_mark_buffer_dirty(c); |
2144 | btrfs_mark_buffer_dirty(split); | |
2145 | ||
db94535d | 2146 | wret = insert_ptr(trans, root, path, &disk_key, split->start, |
5f39d397 | 2147 | path->slots[level + 1] + 1, |
123abc88 | 2148 | level + 1); |
aa5d6bed CM |
2149 | if (wret) |
2150 | ret = wret; | |
2151 | ||
5de08d7d | 2152 | if (path->slots[level] >= mid) { |
5c680ed6 | 2153 | path->slots[level] -= mid; |
925baedd | 2154 | btrfs_tree_unlock(c); |
5f39d397 CM |
2155 | free_extent_buffer(c); |
2156 | path->nodes[level] = split; | |
5c680ed6 CM |
2157 | path->slots[level + 1] += 1; |
2158 | } else { | |
925baedd | 2159 | btrfs_tree_unlock(split); |
5f39d397 | 2160 | free_extent_buffer(split); |
be0e5c09 | 2161 | } |
aa5d6bed | 2162 | return ret; |
be0e5c09 CM |
2163 | } |
2164 | ||
74123bd7 CM |
2165 | /* |
2166 | * how many bytes are required to store the items in a leaf. start | |
2167 | * and nr indicate which items in the leaf to check. This totals up the | |
2168 | * space used both by the item structs and the item data | |
2169 | */ | |
5f39d397 | 2170 | static int leaf_space_used(struct extent_buffer *l, int start, int nr) |
be0e5c09 CM |
2171 | { |
2172 | int data_len; | |
5f39d397 | 2173 | int nritems = btrfs_header_nritems(l); |
d4dbff95 | 2174 | int end = min(nritems, start + nr) - 1; |
be0e5c09 CM |
2175 | |
2176 | if (!nr) | |
2177 | return 0; | |
5f39d397 CM |
2178 | data_len = btrfs_item_end_nr(l, start); |
2179 | data_len = data_len - btrfs_item_offset_nr(l, end); | |
0783fcfc | 2180 | data_len += sizeof(struct btrfs_item) * nr; |
d4dbff95 | 2181 | WARN_ON(data_len < 0); |
be0e5c09 CM |
2182 | return data_len; |
2183 | } | |
2184 | ||
d4dbff95 CM |
2185 | /* |
2186 | * The space between the end of the leaf items and | |
2187 | * the start of the leaf data. IOW, how much room | |
2188 | * the leaf has left for both items and data | |
2189 | */ | |
d397712b | 2190 | noinline int btrfs_leaf_free_space(struct btrfs_root *root, |
e02119d5 | 2191 | struct extent_buffer *leaf) |
d4dbff95 | 2192 | { |
5f39d397 CM |
2193 | int nritems = btrfs_header_nritems(leaf); |
2194 | int ret; | |
2195 | ret = BTRFS_LEAF_DATA_SIZE(root) - leaf_space_used(leaf, 0, nritems); | |
2196 | if (ret < 0) { | |
d397712b CM |
2197 | printk(KERN_CRIT "leaf free space ret %d, leaf data size %lu, " |
2198 | "used %d nritems %d\n", | |
ae2f5411 | 2199 | ret, (unsigned long) BTRFS_LEAF_DATA_SIZE(root), |
5f39d397 CM |
2200 | leaf_space_used(leaf, 0, nritems), nritems); |
2201 | } | |
2202 | return ret; | |
d4dbff95 CM |
2203 | } |
2204 | ||
99d8f83c CM |
2205 | /* |
2206 | * min slot controls the lowest index we're willing to push to the | |
2207 | * right. We'll push up to and including min_slot, but no lower | |
2208 | */ | |
44871b1b CM |
2209 | static noinline int __push_leaf_right(struct btrfs_trans_handle *trans, |
2210 | struct btrfs_root *root, | |
2211 | struct btrfs_path *path, | |
2212 | int data_size, int empty, | |
2213 | struct extent_buffer *right, | |
99d8f83c CM |
2214 | int free_space, u32 left_nritems, |
2215 | u32 min_slot) | |
00ec4c51 | 2216 | { |
5f39d397 | 2217 | struct extent_buffer *left = path->nodes[0]; |
44871b1b | 2218 | struct extent_buffer *upper = path->nodes[1]; |
5f39d397 | 2219 | struct btrfs_disk_key disk_key; |
00ec4c51 | 2220 | int slot; |
34a38218 | 2221 | u32 i; |
00ec4c51 CM |
2222 | int push_space = 0; |
2223 | int push_items = 0; | |
0783fcfc | 2224 | struct btrfs_item *item; |
34a38218 | 2225 | u32 nr; |
7518a238 | 2226 | u32 right_nritems; |
5f39d397 | 2227 | u32 data_end; |
db94535d | 2228 | u32 this_item_size; |
00ec4c51 | 2229 | |
34a38218 CM |
2230 | if (empty) |
2231 | nr = 0; | |
2232 | else | |
99d8f83c | 2233 | nr = max_t(u32, 1, min_slot); |
34a38218 | 2234 | |
31840ae1 | 2235 | if (path->slots[0] >= left_nritems) |
87b29b20 | 2236 | push_space += data_size; |
31840ae1 | 2237 | |
44871b1b | 2238 | slot = path->slots[1]; |
34a38218 CM |
2239 | i = left_nritems - 1; |
2240 | while (i >= nr) { | |
5f39d397 | 2241 | item = btrfs_item_nr(left, i); |
db94535d | 2242 | |
31840ae1 ZY |
2243 | if (!empty && push_items > 0) { |
2244 | if (path->slots[0] > i) | |
2245 | break; | |
2246 | if (path->slots[0] == i) { | |
2247 | int space = btrfs_leaf_free_space(root, left); | |
2248 | if (space + push_space * 2 > free_space) | |
2249 | break; | |
2250 | } | |
2251 | } | |
2252 | ||
00ec4c51 | 2253 | if (path->slots[0] == i) |
87b29b20 | 2254 | push_space += data_size; |
db94535d CM |
2255 | |
2256 | if (!left->map_token) { | |
2257 | map_extent_buffer(left, (unsigned long)item, | |
2258 | sizeof(struct btrfs_item), | |
2259 | &left->map_token, &left->kaddr, | |
2260 | &left->map_start, &left->map_len, | |
2261 | KM_USER1); | |
2262 | } | |
2263 | ||
2264 | this_item_size = btrfs_item_size(left, item); | |
2265 | if (this_item_size + sizeof(*item) + push_space > free_space) | |
00ec4c51 | 2266 | break; |
31840ae1 | 2267 | |
00ec4c51 | 2268 | push_items++; |
db94535d | 2269 | push_space += this_item_size + sizeof(*item); |
34a38218 CM |
2270 | if (i == 0) |
2271 | break; | |
2272 | i--; | |
db94535d CM |
2273 | } |
2274 | if (left->map_token) { | |
2275 | unmap_extent_buffer(left, left->map_token, KM_USER1); | |
2276 | left->map_token = NULL; | |
00ec4c51 | 2277 | } |
5f39d397 | 2278 | |
925baedd CM |
2279 | if (push_items == 0) |
2280 | goto out_unlock; | |
5f39d397 | 2281 | |
34a38218 | 2282 | if (!empty && push_items == left_nritems) |
a429e513 | 2283 | WARN_ON(1); |
5f39d397 | 2284 | |
00ec4c51 | 2285 | /* push left to right */ |
5f39d397 | 2286 | right_nritems = btrfs_header_nritems(right); |
34a38218 | 2287 | |
5f39d397 | 2288 | push_space = btrfs_item_end_nr(left, left_nritems - push_items); |
123abc88 | 2289 | push_space -= leaf_data_end(root, left); |
5f39d397 | 2290 | |
00ec4c51 | 2291 | /* make room in the right data area */ |
5f39d397 CM |
2292 | data_end = leaf_data_end(root, right); |
2293 | memmove_extent_buffer(right, | |
2294 | btrfs_leaf_data(right) + data_end - push_space, | |
2295 | btrfs_leaf_data(right) + data_end, | |
2296 | BTRFS_LEAF_DATA_SIZE(root) - data_end); | |
2297 | ||
00ec4c51 | 2298 | /* copy from the left data area */ |
5f39d397 | 2299 | copy_extent_buffer(right, left, btrfs_leaf_data(right) + |
d6025579 CM |
2300 | BTRFS_LEAF_DATA_SIZE(root) - push_space, |
2301 | btrfs_leaf_data(left) + leaf_data_end(root, left), | |
2302 | push_space); | |
5f39d397 CM |
2303 | |
2304 | memmove_extent_buffer(right, btrfs_item_nr_offset(push_items), | |
2305 | btrfs_item_nr_offset(0), | |
2306 | right_nritems * sizeof(struct btrfs_item)); | |
2307 | ||
00ec4c51 | 2308 | /* copy the items from left to right */ |
5f39d397 CM |
2309 | copy_extent_buffer(right, left, btrfs_item_nr_offset(0), |
2310 | btrfs_item_nr_offset(left_nritems - push_items), | |
2311 | push_items * sizeof(struct btrfs_item)); | |
00ec4c51 CM |
2312 | |
2313 | /* update the item pointers */ | |
7518a238 | 2314 | right_nritems += push_items; |
5f39d397 | 2315 | btrfs_set_header_nritems(right, right_nritems); |
123abc88 | 2316 | push_space = BTRFS_LEAF_DATA_SIZE(root); |
7518a238 | 2317 | for (i = 0; i < right_nritems; i++) { |
5f39d397 | 2318 | item = btrfs_item_nr(right, i); |
db94535d CM |
2319 | if (!right->map_token) { |
2320 | map_extent_buffer(right, (unsigned long)item, | |
2321 | sizeof(struct btrfs_item), | |
2322 | &right->map_token, &right->kaddr, | |
2323 | &right->map_start, &right->map_len, | |
2324 | KM_USER1); | |
2325 | } | |
2326 | push_space -= btrfs_item_size(right, item); | |
2327 | btrfs_set_item_offset(right, item, push_space); | |
2328 | } | |
2329 | ||
2330 | if (right->map_token) { | |
2331 | unmap_extent_buffer(right, right->map_token, KM_USER1); | |
2332 | right->map_token = NULL; | |
00ec4c51 | 2333 | } |
7518a238 | 2334 | left_nritems -= push_items; |
5f39d397 | 2335 | btrfs_set_header_nritems(left, left_nritems); |
00ec4c51 | 2336 | |
34a38218 CM |
2337 | if (left_nritems) |
2338 | btrfs_mark_buffer_dirty(left); | |
f0486c68 YZ |
2339 | else |
2340 | clean_tree_block(trans, root, left); | |
2341 | ||
5f39d397 | 2342 | btrfs_mark_buffer_dirty(right); |
a429e513 | 2343 | |
5f39d397 CM |
2344 | btrfs_item_key(right, &disk_key, 0); |
2345 | btrfs_set_node_key(upper, &disk_key, slot + 1); | |
d6025579 | 2346 | btrfs_mark_buffer_dirty(upper); |
02217ed2 | 2347 | |
00ec4c51 | 2348 | /* then fixup the leaf pointer in the path */ |
7518a238 CM |
2349 | if (path->slots[0] >= left_nritems) { |
2350 | path->slots[0] -= left_nritems; | |
925baedd CM |
2351 | if (btrfs_header_nritems(path->nodes[0]) == 0) |
2352 | clean_tree_block(trans, root, path->nodes[0]); | |
2353 | btrfs_tree_unlock(path->nodes[0]); | |
5f39d397 CM |
2354 | free_extent_buffer(path->nodes[0]); |
2355 | path->nodes[0] = right; | |
00ec4c51 CM |
2356 | path->slots[1] += 1; |
2357 | } else { | |
925baedd | 2358 | btrfs_tree_unlock(right); |
5f39d397 | 2359 | free_extent_buffer(right); |
00ec4c51 CM |
2360 | } |
2361 | return 0; | |
925baedd CM |
2362 | |
2363 | out_unlock: | |
2364 | btrfs_tree_unlock(right); | |
2365 | free_extent_buffer(right); | |
2366 | return 1; | |
00ec4c51 | 2367 | } |
925baedd | 2368 | |
44871b1b CM |
2369 | /* |
2370 | * push some data in the path leaf to the right, trying to free up at | |
2371 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
2372 | * | |
2373 | * returns 1 if the push failed because the other node didn't have enough | |
2374 | * room, 0 if everything worked out and < 0 if there were major errors. | |
99d8f83c CM |
2375 | * |
2376 | * this will push starting from min_slot to the end of the leaf. It won't | |
2377 | * push any slot lower than min_slot | |
44871b1b CM |
2378 | */ |
2379 | static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root | |
99d8f83c CM |
2380 | *root, struct btrfs_path *path, |
2381 | int min_data_size, int data_size, | |
2382 | int empty, u32 min_slot) | |
44871b1b CM |
2383 | { |
2384 | struct extent_buffer *left = path->nodes[0]; | |
2385 | struct extent_buffer *right; | |
2386 | struct extent_buffer *upper; | |
2387 | int slot; | |
2388 | int free_space; | |
2389 | u32 left_nritems; | |
2390 | int ret; | |
2391 | ||
2392 | if (!path->nodes[1]) | |
2393 | return 1; | |
2394 | ||
2395 | slot = path->slots[1]; | |
2396 | upper = path->nodes[1]; | |
2397 | if (slot >= btrfs_header_nritems(upper) - 1) | |
2398 | return 1; | |
2399 | ||
2400 | btrfs_assert_tree_locked(path->nodes[1]); | |
2401 | ||
2402 | right = read_node_slot(root, upper, slot + 1); | |
91ca338d TI |
2403 | if (right == NULL) |
2404 | return 1; | |
2405 | ||
44871b1b CM |
2406 | btrfs_tree_lock(right); |
2407 | btrfs_set_lock_blocking(right); | |
2408 | ||
2409 | free_space = btrfs_leaf_free_space(root, right); | |
2410 | if (free_space < data_size) | |
2411 | goto out_unlock; | |
2412 | ||
2413 | /* cow and double check */ | |
2414 | ret = btrfs_cow_block(trans, root, right, upper, | |
2415 | slot + 1, &right); | |
2416 | if (ret) | |
2417 | goto out_unlock; | |
2418 | ||
2419 | free_space = btrfs_leaf_free_space(root, right); | |
2420 | if (free_space < data_size) | |
2421 | goto out_unlock; | |
2422 | ||
2423 | left_nritems = btrfs_header_nritems(left); | |
2424 | if (left_nritems == 0) | |
2425 | goto out_unlock; | |
2426 | ||
99d8f83c CM |
2427 | return __push_leaf_right(trans, root, path, min_data_size, empty, |
2428 | right, free_space, left_nritems, min_slot); | |
44871b1b CM |
2429 | out_unlock: |
2430 | btrfs_tree_unlock(right); | |
2431 | free_extent_buffer(right); | |
2432 | return 1; | |
2433 | } | |
2434 | ||
74123bd7 CM |
2435 | /* |
2436 | * push some data in the path leaf to the left, trying to free up at | |
2437 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
99d8f83c CM |
2438 | * |
2439 | * max_slot can put a limit on how far into the leaf we'll push items. The | |
2440 | * item at 'max_slot' won't be touched. Use (u32)-1 to make us do all the | |
2441 | * items | |
74123bd7 | 2442 | */ |
44871b1b CM |
2443 | static noinline int __push_leaf_left(struct btrfs_trans_handle *trans, |
2444 | struct btrfs_root *root, | |
2445 | struct btrfs_path *path, int data_size, | |
2446 | int empty, struct extent_buffer *left, | |
99d8f83c CM |
2447 | int free_space, u32 right_nritems, |
2448 | u32 max_slot) | |
be0e5c09 | 2449 | { |
5f39d397 CM |
2450 | struct btrfs_disk_key disk_key; |
2451 | struct extent_buffer *right = path->nodes[0]; | |
be0e5c09 | 2452 | int i; |
be0e5c09 CM |
2453 | int push_space = 0; |
2454 | int push_items = 0; | |
0783fcfc | 2455 | struct btrfs_item *item; |
7518a238 | 2456 | u32 old_left_nritems; |
34a38218 | 2457 | u32 nr; |
aa5d6bed CM |
2458 | int ret = 0; |
2459 | int wret; | |
db94535d CM |
2460 | u32 this_item_size; |
2461 | u32 old_left_item_size; | |
be0e5c09 | 2462 | |
34a38218 | 2463 | if (empty) |
99d8f83c | 2464 | nr = min(right_nritems, max_slot); |
34a38218 | 2465 | else |
99d8f83c | 2466 | nr = min(right_nritems - 1, max_slot); |
34a38218 CM |
2467 | |
2468 | for (i = 0; i < nr; i++) { | |
5f39d397 | 2469 | item = btrfs_item_nr(right, i); |
db94535d CM |
2470 | if (!right->map_token) { |
2471 | map_extent_buffer(right, (unsigned long)item, | |
2472 | sizeof(struct btrfs_item), | |
2473 | &right->map_token, &right->kaddr, | |
2474 | &right->map_start, &right->map_len, | |
2475 | KM_USER1); | |
2476 | } | |
2477 | ||
31840ae1 ZY |
2478 | if (!empty && push_items > 0) { |
2479 | if (path->slots[0] < i) | |
2480 | break; | |
2481 | if (path->slots[0] == i) { | |
2482 | int space = btrfs_leaf_free_space(root, right); | |
2483 | if (space + push_space * 2 > free_space) | |
2484 | break; | |
2485 | } | |
2486 | } | |
2487 | ||
be0e5c09 | 2488 | if (path->slots[0] == i) |
87b29b20 | 2489 | push_space += data_size; |
db94535d CM |
2490 | |
2491 | this_item_size = btrfs_item_size(right, item); | |
2492 | if (this_item_size + sizeof(*item) + push_space > free_space) | |
be0e5c09 | 2493 | break; |
db94535d | 2494 | |
be0e5c09 | 2495 | push_items++; |
db94535d CM |
2496 | push_space += this_item_size + sizeof(*item); |
2497 | } | |
2498 | ||
2499 | if (right->map_token) { | |
2500 | unmap_extent_buffer(right, right->map_token, KM_USER1); | |
2501 | right->map_token = NULL; | |
be0e5c09 | 2502 | } |
db94535d | 2503 | |
be0e5c09 | 2504 | if (push_items == 0) { |
925baedd CM |
2505 | ret = 1; |
2506 | goto out; | |
be0e5c09 | 2507 | } |
34a38218 | 2508 | if (!empty && push_items == btrfs_header_nritems(right)) |
a429e513 | 2509 | WARN_ON(1); |
5f39d397 | 2510 | |
be0e5c09 | 2511 | /* push data from right to left */ |
5f39d397 CM |
2512 | copy_extent_buffer(left, right, |
2513 | btrfs_item_nr_offset(btrfs_header_nritems(left)), | |
2514 | btrfs_item_nr_offset(0), | |
2515 | push_items * sizeof(struct btrfs_item)); | |
2516 | ||
123abc88 | 2517 | push_space = BTRFS_LEAF_DATA_SIZE(root) - |
d397712b | 2518 | btrfs_item_offset_nr(right, push_items - 1); |
5f39d397 CM |
2519 | |
2520 | copy_extent_buffer(left, right, btrfs_leaf_data(left) + | |
d6025579 CM |
2521 | leaf_data_end(root, left) - push_space, |
2522 | btrfs_leaf_data(right) + | |
5f39d397 | 2523 | btrfs_item_offset_nr(right, push_items - 1), |
d6025579 | 2524 | push_space); |
5f39d397 | 2525 | old_left_nritems = btrfs_header_nritems(left); |
87b29b20 | 2526 | BUG_ON(old_left_nritems <= 0); |
eb60ceac | 2527 | |
db94535d | 2528 | old_left_item_size = btrfs_item_offset_nr(left, old_left_nritems - 1); |
0783fcfc | 2529 | for (i = old_left_nritems; i < old_left_nritems + push_items; i++) { |
5f39d397 | 2530 | u32 ioff; |
db94535d | 2531 | |
5f39d397 | 2532 | item = btrfs_item_nr(left, i); |
db94535d CM |
2533 | if (!left->map_token) { |
2534 | map_extent_buffer(left, (unsigned long)item, | |
2535 | sizeof(struct btrfs_item), | |
2536 | &left->map_token, &left->kaddr, | |
2537 | &left->map_start, &left->map_len, | |
2538 | KM_USER1); | |
2539 | } | |
2540 | ||
5f39d397 CM |
2541 | ioff = btrfs_item_offset(left, item); |
2542 | btrfs_set_item_offset(left, item, | |
db94535d | 2543 | ioff - (BTRFS_LEAF_DATA_SIZE(root) - old_left_item_size)); |
be0e5c09 | 2544 | } |
5f39d397 | 2545 | btrfs_set_header_nritems(left, old_left_nritems + push_items); |
db94535d CM |
2546 | if (left->map_token) { |
2547 | unmap_extent_buffer(left, left->map_token, KM_USER1); | |
2548 | left->map_token = NULL; | |
2549 | } | |
be0e5c09 CM |
2550 | |
2551 | /* fixup right node */ | |
34a38218 | 2552 | if (push_items > right_nritems) { |
d397712b CM |
2553 | printk(KERN_CRIT "push items %d nr %u\n", push_items, |
2554 | right_nritems); | |
34a38218 CM |
2555 | WARN_ON(1); |
2556 | } | |
2557 | ||
2558 | if (push_items < right_nritems) { | |
2559 | push_space = btrfs_item_offset_nr(right, push_items - 1) - | |
2560 | leaf_data_end(root, right); | |
2561 | memmove_extent_buffer(right, btrfs_leaf_data(right) + | |
2562 | BTRFS_LEAF_DATA_SIZE(root) - push_space, | |
2563 | btrfs_leaf_data(right) + | |
2564 | leaf_data_end(root, right), push_space); | |
2565 | ||
2566 | memmove_extent_buffer(right, btrfs_item_nr_offset(0), | |
5f39d397 CM |
2567 | btrfs_item_nr_offset(push_items), |
2568 | (btrfs_header_nritems(right) - push_items) * | |
2569 | sizeof(struct btrfs_item)); | |
34a38218 | 2570 | } |
eef1c494 Y |
2571 | right_nritems -= push_items; |
2572 | btrfs_set_header_nritems(right, right_nritems); | |
123abc88 | 2573 | push_space = BTRFS_LEAF_DATA_SIZE(root); |
5f39d397 CM |
2574 | for (i = 0; i < right_nritems; i++) { |
2575 | item = btrfs_item_nr(right, i); | |
db94535d CM |
2576 | |
2577 | if (!right->map_token) { | |
2578 | map_extent_buffer(right, (unsigned long)item, | |
2579 | sizeof(struct btrfs_item), | |
2580 | &right->map_token, &right->kaddr, | |
2581 | &right->map_start, &right->map_len, | |
2582 | KM_USER1); | |
2583 | } | |
2584 | ||
2585 | push_space = push_space - btrfs_item_size(right, item); | |
2586 | btrfs_set_item_offset(right, item, push_space); | |
2587 | } | |
2588 | if (right->map_token) { | |
2589 | unmap_extent_buffer(right, right->map_token, KM_USER1); | |
2590 | right->map_token = NULL; | |
be0e5c09 | 2591 | } |
eb60ceac | 2592 | |
5f39d397 | 2593 | btrfs_mark_buffer_dirty(left); |
34a38218 CM |
2594 | if (right_nritems) |
2595 | btrfs_mark_buffer_dirty(right); | |
f0486c68 YZ |
2596 | else |
2597 | clean_tree_block(trans, root, right); | |
098f59c2 | 2598 | |
5f39d397 CM |
2599 | btrfs_item_key(right, &disk_key, 0); |
2600 | wret = fixup_low_keys(trans, root, path, &disk_key, 1); | |
aa5d6bed CM |
2601 | if (wret) |
2602 | ret = wret; | |
be0e5c09 CM |
2603 | |
2604 | /* then fixup the leaf pointer in the path */ | |
2605 | if (path->slots[0] < push_items) { | |
2606 | path->slots[0] += old_left_nritems; | |
925baedd | 2607 | btrfs_tree_unlock(path->nodes[0]); |
5f39d397 CM |
2608 | free_extent_buffer(path->nodes[0]); |
2609 | path->nodes[0] = left; | |
be0e5c09 CM |
2610 | path->slots[1] -= 1; |
2611 | } else { | |
925baedd | 2612 | btrfs_tree_unlock(left); |
5f39d397 | 2613 | free_extent_buffer(left); |
be0e5c09 CM |
2614 | path->slots[0] -= push_items; |
2615 | } | |
eb60ceac | 2616 | BUG_ON(path->slots[0] < 0); |
aa5d6bed | 2617 | return ret; |
925baedd CM |
2618 | out: |
2619 | btrfs_tree_unlock(left); | |
2620 | free_extent_buffer(left); | |
2621 | return ret; | |
be0e5c09 CM |
2622 | } |
2623 | ||
44871b1b CM |
2624 | /* |
2625 | * push some data in the path leaf to the left, trying to free up at | |
2626 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
99d8f83c CM |
2627 | * |
2628 | * max_slot can put a limit on how far into the leaf we'll push items. The | |
2629 | * item at 'max_slot' won't be touched. Use (u32)-1 to make us push all the | |
2630 | * items | |
44871b1b CM |
2631 | */ |
2632 | static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root | |
99d8f83c CM |
2633 | *root, struct btrfs_path *path, int min_data_size, |
2634 | int data_size, int empty, u32 max_slot) | |
44871b1b CM |
2635 | { |
2636 | struct extent_buffer *right = path->nodes[0]; | |
2637 | struct extent_buffer *left; | |
2638 | int slot; | |
2639 | int free_space; | |
2640 | u32 right_nritems; | |
2641 | int ret = 0; | |
2642 | ||
2643 | slot = path->slots[1]; | |
2644 | if (slot == 0) | |
2645 | return 1; | |
2646 | if (!path->nodes[1]) | |
2647 | return 1; | |
2648 | ||
2649 | right_nritems = btrfs_header_nritems(right); | |
2650 | if (right_nritems == 0) | |
2651 | return 1; | |
2652 | ||
2653 | btrfs_assert_tree_locked(path->nodes[1]); | |
2654 | ||
2655 | left = read_node_slot(root, path->nodes[1], slot - 1); | |
91ca338d TI |
2656 | if (left == NULL) |
2657 | return 1; | |
2658 | ||
44871b1b CM |
2659 | btrfs_tree_lock(left); |
2660 | btrfs_set_lock_blocking(left); | |
2661 | ||
2662 | free_space = btrfs_leaf_free_space(root, left); | |
2663 | if (free_space < data_size) { | |
2664 | ret = 1; | |
2665 | goto out; | |
2666 | } | |
2667 | ||
2668 | /* cow and double check */ | |
2669 | ret = btrfs_cow_block(trans, root, left, | |
2670 | path->nodes[1], slot - 1, &left); | |
2671 | if (ret) { | |
2672 | /* we hit -ENOSPC, but it isn't fatal here */ | |
2673 | ret = 1; | |
2674 | goto out; | |
2675 | } | |
2676 | ||
2677 | free_space = btrfs_leaf_free_space(root, left); | |
2678 | if (free_space < data_size) { | |
2679 | ret = 1; | |
2680 | goto out; | |
2681 | } | |
2682 | ||
99d8f83c CM |
2683 | return __push_leaf_left(trans, root, path, min_data_size, |
2684 | empty, left, free_space, right_nritems, | |
2685 | max_slot); | |
44871b1b CM |
2686 | out: |
2687 | btrfs_tree_unlock(left); | |
2688 | free_extent_buffer(left); | |
2689 | return ret; | |
2690 | } | |
2691 | ||
2692 | /* | |
2693 | * split the path's leaf in two, making sure there is at least data_size | |
2694 | * available for the resulting leaf level of the path. | |
2695 | * | |
2696 | * returns 0 if all went well and < 0 on failure. | |
2697 | */ | |
2698 | static noinline int copy_for_split(struct btrfs_trans_handle *trans, | |
2699 | struct btrfs_root *root, | |
2700 | struct btrfs_path *path, | |
2701 | struct extent_buffer *l, | |
2702 | struct extent_buffer *right, | |
2703 | int slot, int mid, int nritems) | |
2704 | { | |
2705 | int data_copy_size; | |
2706 | int rt_data_off; | |
2707 | int i; | |
2708 | int ret = 0; | |
2709 | int wret; | |
2710 | struct btrfs_disk_key disk_key; | |
2711 | ||
2712 | nritems = nritems - mid; | |
2713 | btrfs_set_header_nritems(right, nritems); | |
2714 | data_copy_size = btrfs_item_end_nr(l, mid) - leaf_data_end(root, l); | |
2715 | ||
2716 | copy_extent_buffer(right, l, btrfs_item_nr_offset(0), | |
2717 | btrfs_item_nr_offset(mid), | |
2718 | nritems * sizeof(struct btrfs_item)); | |
2719 | ||
2720 | copy_extent_buffer(right, l, | |
2721 | btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) - | |
2722 | data_copy_size, btrfs_leaf_data(l) + | |
2723 | leaf_data_end(root, l), data_copy_size); | |
2724 | ||
2725 | rt_data_off = BTRFS_LEAF_DATA_SIZE(root) - | |
2726 | btrfs_item_end_nr(l, mid); | |
2727 | ||
2728 | for (i = 0; i < nritems; i++) { | |
2729 | struct btrfs_item *item = btrfs_item_nr(right, i); | |
2730 | u32 ioff; | |
2731 | ||
2732 | if (!right->map_token) { | |
2733 | map_extent_buffer(right, (unsigned long)item, | |
2734 | sizeof(struct btrfs_item), | |
2735 | &right->map_token, &right->kaddr, | |
2736 | &right->map_start, &right->map_len, | |
2737 | KM_USER1); | |
2738 | } | |
2739 | ||
2740 | ioff = btrfs_item_offset(right, item); | |
2741 | btrfs_set_item_offset(right, item, ioff + rt_data_off); | |
2742 | } | |
2743 | ||
2744 | if (right->map_token) { | |
2745 | unmap_extent_buffer(right, right->map_token, KM_USER1); | |
2746 | right->map_token = NULL; | |
2747 | } | |
2748 | ||
2749 | btrfs_set_header_nritems(l, mid); | |
2750 | ret = 0; | |
2751 | btrfs_item_key(right, &disk_key, 0); | |
2752 | wret = insert_ptr(trans, root, path, &disk_key, right->start, | |
2753 | path->slots[1] + 1, 1); | |
2754 | if (wret) | |
2755 | ret = wret; | |
2756 | ||
2757 | btrfs_mark_buffer_dirty(right); | |
2758 | btrfs_mark_buffer_dirty(l); | |
2759 | BUG_ON(path->slots[0] != slot); | |
2760 | ||
44871b1b CM |
2761 | if (mid <= slot) { |
2762 | btrfs_tree_unlock(path->nodes[0]); | |
2763 | free_extent_buffer(path->nodes[0]); | |
2764 | path->nodes[0] = right; | |
2765 | path->slots[0] -= mid; | |
2766 | path->slots[1] += 1; | |
2767 | } else { | |
2768 | btrfs_tree_unlock(right); | |
2769 | free_extent_buffer(right); | |
2770 | } | |
2771 | ||
2772 | BUG_ON(path->slots[0] < 0); | |
2773 | ||
2774 | return ret; | |
2775 | } | |
2776 | ||
99d8f83c CM |
2777 | /* |
2778 | * double splits happen when we need to insert a big item in the middle | |
2779 | * of a leaf. A double split can leave us with 3 mostly empty leaves: | |
2780 | * leaf: [ slots 0 - N] [ our target ] [ N + 1 - total in leaf ] | |
2781 | * A B C | |
2782 | * | |
2783 | * We avoid this by trying to push the items on either side of our target | |
2784 | * into the adjacent leaves. If all goes well we can avoid the double split | |
2785 | * completely. | |
2786 | */ | |
2787 | static noinline int push_for_double_split(struct btrfs_trans_handle *trans, | |
2788 | struct btrfs_root *root, | |
2789 | struct btrfs_path *path, | |
2790 | int data_size) | |
2791 | { | |
2792 | int ret; | |
2793 | int progress = 0; | |
2794 | int slot; | |
2795 | u32 nritems; | |
2796 | ||
2797 | slot = path->slots[0]; | |
2798 | ||
2799 | /* | |
2800 | * try to push all the items after our slot into the | |
2801 | * right leaf | |
2802 | */ | |
2803 | ret = push_leaf_right(trans, root, path, 1, data_size, 0, slot); | |
2804 | if (ret < 0) | |
2805 | return ret; | |
2806 | ||
2807 | if (ret == 0) | |
2808 | progress++; | |
2809 | ||
2810 | nritems = btrfs_header_nritems(path->nodes[0]); | |
2811 | /* | |
2812 | * our goal is to get our slot at the start or end of a leaf. If | |
2813 | * we've done so we're done | |
2814 | */ | |
2815 | if (path->slots[0] == 0 || path->slots[0] == nritems) | |
2816 | return 0; | |
2817 | ||
2818 | if (btrfs_leaf_free_space(root, path->nodes[0]) >= data_size) | |
2819 | return 0; | |
2820 | ||
2821 | /* try to push all the items before our slot into the next leaf */ | |
2822 | slot = path->slots[0]; | |
2823 | ret = push_leaf_left(trans, root, path, 1, data_size, 0, slot); | |
2824 | if (ret < 0) | |
2825 | return ret; | |
2826 | ||
2827 | if (ret == 0) | |
2828 | progress++; | |
2829 | ||
2830 | if (progress) | |
2831 | return 0; | |
2832 | return 1; | |
2833 | } | |
2834 | ||
74123bd7 CM |
2835 | /* |
2836 | * split the path's leaf in two, making sure there is at least data_size | |
2837 | * available for the resulting leaf level of the path. | |
aa5d6bed CM |
2838 | * |
2839 | * returns 0 if all went well and < 0 on failure. | |
74123bd7 | 2840 | */ |
e02119d5 CM |
2841 | static noinline int split_leaf(struct btrfs_trans_handle *trans, |
2842 | struct btrfs_root *root, | |
2843 | struct btrfs_key *ins_key, | |
2844 | struct btrfs_path *path, int data_size, | |
2845 | int extend) | |
be0e5c09 | 2846 | { |
5d4f98a2 | 2847 | struct btrfs_disk_key disk_key; |
5f39d397 | 2848 | struct extent_buffer *l; |
7518a238 | 2849 | u32 nritems; |
eb60ceac CM |
2850 | int mid; |
2851 | int slot; | |
5f39d397 | 2852 | struct extent_buffer *right; |
d4dbff95 | 2853 | int ret = 0; |
aa5d6bed | 2854 | int wret; |
5d4f98a2 | 2855 | int split; |
cc0c5538 | 2856 | int num_doubles = 0; |
99d8f83c | 2857 | int tried_avoid_double = 0; |
aa5d6bed | 2858 | |
a5719521 YZ |
2859 | l = path->nodes[0]; |
2860 | slot = path->slots[0]; | |
2861 | if (extend && data_size + btrfs_item_size_nr(l, slot) + | |
2862 | sizeof(struct btrfs_item) > BTRFS_LEAF_DATA_SIZE(root)) | |
2863 | return -EOVERFLOW; | |
2864 | ||
40689478 | 2865 | /* first try to make some room by pushing left and right */ |
99d8f83c CM |
2866 | if (data_size) { |
2867 | wret = push_leaf_right(trans, root, path, data_size, | |
2868 | data_size, 0, 0); | |
d397712b | 2869 | if (wret < 0) |
eaee50e8 | 2870 | return wret; |
3685f791 | 2871 | if (wret) { |
99d8f83c CM |
2872 | wret = push_leaf_left(trans, root, path, data_size, |
2873 | data_size, 0, (u32)-1); | |
3685f791 CM |
2874 | if (wret < 0) |
2875 | return wret; | |
2876 | } | |
2877 | l = path->nodes[0]; | |
aa5d6bed | 2878 | |
3685f791 | 2879 | /* did the pushes work? */ |
87b29b20 | 2880 | if (btrfs_leaf_free_space(root, l) >= data_size) |
3685f791 | 2881 | return 0; |
3326d1b0 | 2882 | } |
aa5d6bed | 2883 | |
5c680ed6 | 2884 | if (!path->nodes[1]) { |
e089f05c | 2885 | ret = insert_new_root(trans, root, path, 1); |
5c680ed6 CM |
2886 | if (ret) |
2887 | return ret; | |
2888 | } | |
cc0c5538 | 2889 | again: |
5d4f98a2 | 2890 | split = 1; |
cc0c5538 | 2891 | l = path->nodes[0]; |
eb60ceac | 2892 | slot = path->slots[0]; |
5f39d397 | 2893 | nritems = btrfs_header_nritems(l); |
d397712b | 2894 | mid = (nritems + 1) / 2; |
54aa1f4d | 2895 | |
5d4f98a2 YZ |
2896 | if (mid <= slot) { |
2897 | if (nritems == 1 || | |
2898 | leaf_space_used(l, mid, nritems - mid) + data_size > | |
2899 | BTRFS_LEAF_DATA_SIZE(root)) { | |
2900 | if (slot >= nritems) { | |
2901 | split = 0; | |
2902 | } else { | |
2903 | mid = slot; | |
2904 | if (mid != nritems && | |
2905 | leaf_space_used(l, mid, nritems - mid) + | |
2906 | data_size > BTRFS_LEAF_DATA_SIZE(root)) { | |
99d8f83c CM |
2907 | if (data_size && !tried_avoid_double) |
2908 | goto push_for_double; | |
5d4f98a2 YZ |
2909 | split = 2; |
2910 | } | |
2911 | } | |
2912 | } | |
2913 | } else { | |
2914 | if (leaf_space_used(l, 0, mid) + data_size > | |
2915 | BTRFS_LEAF_DATA_SIZE(root)) { | |
2916 | if (!extend && data_size && slot == 0) { | |
2917 | split = 0; | |
2918 | } else if ((extend || !data_size) && slot == 0) { | |
2919 | mid = 1; | |
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 | } | |
2932 | ||
2933 | if (split == 0) | |
2934 | btrfs_cpu_key_to_disk(&disk_key, ins_key); | |
2935 | else | |
2936 | btrfs_item_key(l, &disk_key, mid); | |
2937 | ||
2938 | right = btrfs_alloc_free_block(trans, root, root->leafsize, 0, | |
31840ae1 | 2939 | root->root_key.objectid, |
5d4f98a2 | 2940 | &disk_key, 0, l->start, 0); |
f0486c68 | 2941 | if (IS_ERR(right)) |
5f39d397 | 2942 | return PTR_ERR(right); |
f0486c68 YZ |
2943 | |
2944 | root_add_used(root, root->leafsize); | |
5f39d397 CM |
2945 | |
2946 | memset_extent_buffer(right, 0, 0, sizeof(struct btrfs_header)); | |
db94535d | 2947 | btrfs_set_header_bytenr(right, right->start); |
5f39d397 | 2948 | btrfs_set_header_generation(right, trans->transid); |
5d4f98a2 | 2949 | btrfs_set_header_backref_rev(right, BTRFS_MIXED_BACKREF_REV); |
5f39d397 CM |
2950 | btrfs_set_header_owner(right, root->root_key.objectid); |
2951 | btrfs_set_header_level(right, 0); | |
2952 | write_extent_buffer(right, root->fs_info->fsid, | |
2953 | (unsigned long)btrfs_header_fsid(right), | |
2954 | BTRFS_FSID_SIZE); | |
e17cade2 CM |
2955 | |
2956 | write_extent_buffer(right, root->fs_info->chunk_tree_uuid, | |
2957 | (unsigned long)btrfs_header_chunk_tree_uuid(right), | |
2958 | BTRFS_UUID_SIZE); | |
44871b1b | 2959 | |
5d4f98a2 YZ |
2960 | if (split == 0) { |
2961 | if (mid <= slot) { | |
2962 | btrfs_set_header_nritems(right, 0); | |
2963 | wret = insert_ptr(trans, root, path, | |
2964 | &disk_key, right->start, | |
2965 | path->slots[1] + 1, 1); | |
2966 | if (wret) | |
2967 | ret = wret; | |
925baedd | 2968 | |
5d4f98a2 YZ |
2969 | btrfs_tree_unlock(path->nodes[0]); |
2970 | free_extent_buffer(path->nodes[0]); | |
2971 | path->nodes[0] = right; | |
2972 | path->slots[0] = 0; | |
2973 | path->slots[1] += 1; | |
2974 | } else { | |
2975 | btrfs_set_header_nritems(right, 0); | |
2976 | wret = insert_ptr(trans, root, path, | |
2977 | &disk_key, | |
2978 | right->start, | |
2979 | path->slots[1], 1); | |
2980 | if (wret) | |
2981 | ret = wret; | |
2982 | btrfs_tree_unlock(path->nodes[0]); | |
2983 | free_extent_buffer(path->nodes[0]); | |
2984 | path->nodes[0] = right; | |
2985 | path->slots[0] = 0; | |
2986 | if (path->slots[1] == 0) { | |
2987 | wret = fixup_low_keys(trans, root, | |
2988 | path, &disk_key, 1); | |
d4dbff95 CM |
2989 | if (wret) |
2990 | ret = wret; | |
5ee78ac7 | 2991 | } |
d4dbff95 | 2992 | } |
5d4f98a2 YZ |
2993 | btrfs_mark_buffer_dirty(right); |
2994 | return ret; | |
d4dbff95 | 2995 | } |
74123bd7 | 2996 | |
44871b1b | 2997 | ret = copy_for_split(trans, root, path, l, right, slot, mid, nritems); |
31840ae1 ZY |
2998 | BUG_ON(ret); |
2999 | ||
5d4f98a2 | 3000 | if (split == 2) { |
cc0c5538 CM |
3001 | BUG_ON(num_doubles != 0); |
3002 | num_doubles++; | |
3003 | goto again; | |
a429e513 | 3004 | } |
44871b1b | 3005 | |
be0e5c09 | 3006 | return ret; |
99d8f83c CM |
3007 | |
3008 | push_for_double: | |
3009 | push_for_double_split(trans, root, path, data_size); | |
3010 | tried_avoid_double = 1; | |
3011 | if (btrfs_leaf_free_space(root, path->nodes[0]) >= data_size) | |
3012 | return 0; | |
3013 | goto again; | |
be0e5c09 CM |
3014 | } |
3015 | ||
ad48fd75 YZ |
3016 | static noinline int setup_leaf_for_split(struct btrfs_trans_handle *trans, |
3017 | struct btrfs_root *root, | |
3018 | struct btrfs_path *path, int ins_len) | |
459931ec | 3019 | { |
ad48fd75 | 3020 | struct btrfs_key key; |
459931ec | 3021 | struct extent_buffer *leaf; |
ad48fd75 YZ |
3022 | struct btrfs_file_extent_item *fi; |
3023 | u64 extent_len = 0; | |
3024 | u32 item_size; | |
3025 | int ret; | |
459931ec CM |
3026 | |
3027 | leaf = path->nodes[0]; | |
ad48fd75 YZ |
3028 | btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
3029 | ||
3030 | BUG_ON(key.type != BTRFS_EXTENT_DATA_KEY && | |
3031 | key.type != BTRFS_EXTENT_CSUM_KEY); | |
3032 | ||
3033 | if (btrfs_leaf_free_space(root, leaf) >= ins_len) | |
3034 | return 0; | |
459931ec CM |
3035 | |
3036 | item_size = btrfs_item_size_nr(leaf, path->slots[0]); | |
ad48fd75 YZ |
3037 | if (key.type == BTRFS_EXTENT_DATA_KEY) { |
3038 | fi = btrfs_item_ptr(leaf, path->slots[0], | |
3039 | struct btrfs_file_extent_item); | |
3040 | extent_len = btrfs_file_extent_num_bytes(leaf, fi); | |
3041 | } | |
b3b4aa74 | 3042 | btrfs_release_path(path); |
459931ec | 3043 | |
459931ec | 3044 | path->keep_locks = 1; |
ad48fd75 YZ |
3045 | path->search_for_split = 1; |
3046 | ret = btrfs_search_slot(trans, root, &key, path, 0, 1); | |
459931ec | 3047 | path->search_for_split = 0; |
ad48fd75 YZ |
3048 | if (ret < 0) |
3049 | goto err; | |
459931ec | 3050 | |
ad48fd75 YZ |
3051 | ret = -EAGAIN; |
3052 | leaf = path->nodes[0]; | |
459931ec | 3053 | /* if our item isn't there or got smaller, return now */ |
ad48fd75 YZ |
3054 | if (ret > 0 || item_size != btrfs_item_size_nr(leaf, path->slots[0])) |
3055 | goto err; | |
3056 | ||
109f6aef CM |
3057 | /* the leaf has changed, it now has room. return now */ |
3058 | if (btrfs_leaf_free_space(root, path->nodes[0]) >= ins_len) | |
3059 | goto err; | |
3060 | ||
ad48fd75 YZ |
3061 | if (key.type == BTRFS_EXTENT_DATA_KEY) { |
3062 | fi = btrfs_item_ptr(leaf, path->slots[0], | |
3063 | struct btrfs_file_extent_item); | |
3064 | if (extent_len != btrfs_file_extent_num_bytes(leaf, fi)) | |
3065 | goto err; | |
459931ec CM |
3066 | } |
3067 | ||
b9473439 | 3068 | btrfs_set_path_blocking(path); |
ad48fd75 | 3069 | ret = split_leaf(trans, root, &key, path, ins_len, 1); |
f0486c68 YZ |
3070 | if (ret) |
3071 | goto err; | |
459931ec | 3072 | |
ad48fd75 | 3073 | path->keep_locks = 0; |
b9473439 | 3074 | btrfs_unlock_up_safe(path, 1); |
ad48fd75 YZ |
3075 | return 0; |
3076 | err: | |
3077 | path->keep_locks = 0; | |
3078 | return ret; | |
3079 | } | |
3080 | ||
3081 | static noinline int split_item(struct btrfs_trans_handle *trans, | |
3082 | struct btrfs_root *root, | |
3083 | struct btrfs_path *path, | |
3084 | struct btrfs_key *new_key, | |
3085 | unsigned long split_offset) | |
3086 | { | |
3087 | struct extent_buffer *leaf; | |
3088 | struct btrfs_item *item; | |
3089 | struct btrfs_item *new_item; | |
3090 | int slot; | |
3091 | char *buf; | |
3092 | u32 nritems; | |
3093 | u32 item_size; | |
3094 | u32 orig_offset; | |
3095 | struct btrfs_disk_key disk_key; | |
3096 | ||
b9473439 CM |
3097 | leaf = path->nodes[0]; |
3098 | BUG_ON(btrfs_leaf_free_space(root, leaf) < sizeof(struct btrfs_item)); | |
3099 | ||
b4ce94de CM |
3100 | btrfs_set_path_blocking(path); |
3101 | ||
459931ec CM |
3102 | item = btrfs_item_nr(leaf, path->slots[0]); |
3103 | orig_offset = btrfs_item_offset(leaf, item); | |
3104 | item_size = btrfs_item_size(leaf, item); | |
3105 | ||
459931ec | 3106 | buf = kmalloc(item_size, GFP_NOFS); |
ad48fd75 YZ |
3107 | if (!buf) |
3108 | return -ENOMEM; | |
3109 | ||
459931ec CM |
3110 | read_extent_buffer(leaf, buf, btrfs_item_ptr_offset(leaf, |
3111 | path->slots[0]), item_size); | |
459931ec | 3112 | |
ad48fd75 | 3113 | slot = path->slots[0] + 1; |
459931ec | 3114 | nritems = btrfs_header_nritems(leaf); |
459931ec CM |
3115 | if (slot != nritems) { |
3116 | /* shift the items */ | |
3117 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + 1), | |
ad48fd75 YZ |
3118 | btrfs_item_nr_offset(slot), |
3119 | (nritems - slot) * sizeof(struct btrfs_item)); | |
459931ec CM |
3120 | } |
3121 | ||
3122 | btrfs_cpu_key_to_disk(&disk_key, new_key); | |
3123 | btrfs_set_item_key(leaf, &disk_key, slot); | |
3124 | ||
3125 | new_item = btrfs_item_nr(leaf, slot); | |
3126 | ||
3127 | btrfs_set_item_offset(leaf, new_item, orig_offset); | |
3128 | btrfs_set_item_size(leaf, new_item, item_size - split_offset); | |
3129 | ||
3130 | btrfs_set_item_offset(leaf, item, | |
3131 | orig_offset + item_size - split_offset); | |
3132 | btrfs_set_item_size(leaf, item, split_offset); | |
3133 | ||
3134 | btrfs_set_header_nritems(leaf, nritems + 1); | |
3135 | ||
3136 | /* write the data for the start of the original item */ | |
3137 | write_extent_buffer(leaf, buf, | |
3138 | btrfs_item_ptr_offset(leaf, path->slots[0]), | |
3139 | split_offset); | |
3140 | ||
3141 | /* write the data for the new item */ | |
3142 | write_extent_buffer(leaf, buf + split_offset, | |
3143 | btrfs_item_ptr_offset(leaf, slot), | |
3144 | item_size - split_offset); | |
3145 | btrfs_mark_buffer_dirty(leaf); | |
3146 | ||
ad48fd75 | 3147 | BUG_ON(btrfs_leaf_free_space(root, leaf) < 0); |
459931ec | 3148 | kfree(buf); |
ad48fd75 YZ |
3149 | return 0; |
3150 | } | |
3151 | ||
3152 | /* | |
3153 | * This function splits a single item into two items, | |
3154 | * giving 'new_key' to the new item and splitting the | |
3155 | * old one at split_offset (from the start of the item). | |
3156 | * | |
3157 | * The path may be released by this operation. After | |
3158 | * the split, the path is pointing to the old item. The | |
3159 | * new item is going to be in the same node as the old one. | |
3160 | * | |
3161 | * Note, the item being split must be smaller enough to live alone on | |
3162 | * a tree block with room for one extra struct btrfs_item | |
3163 | * | |
3164 | * This allows us to split the item in place, keeping a lock on the | |
3165 | * leaf the entire time. | |
3166 | */ | |
3167 | int btrfs_split_item(struct btrfs_trans_handle *trans, | |
3168 | struct btrfs_root *root, | |
3169 | struct btrfs_path *path, | |
3170 | struct btrfs_key *new_key, | |
3171 | unsigned long split_offset) | |
3172 | { | |
3173 | int ret; | |
3174 | ret = setup_leaf_for_split(trans, root, path, | |
3175 | sizeof(struct btrfs_item)); | |
3176 | if (ret) | |
3177 | return ret; | |
3178 | ||
3179 | ret = split_item(trans, root, path, new_key, split_offset); | |
459931ec CM |
3180 | return ret; |
3181 | } | |
3182 | ||
ad48fd75 YZ |
3183 | /* |
3184 | * This function duplicate a item, giving 'new_key' to the new item. | |
3185 | * It guarantees both items live in the same tree leaf and the new item | |
3186 | * is contiguous with the original item. | |
3187 | * | |
3188 | * This allows us to split file extent in place, keeping a lock on the | |
3189 | * leaf the entire time. | |
3190 | */ | |
3191 | int btrfs_duplicate_item(struct btrfs_trans_handle *trans, | |
3192 | struct btrfs_root *root, | |
3193 | struct btrfs_path *path, | |
3194 | struct btrfs_key *new_key) | |
3195 | { | |
3196 | struct extent_buffer *leaf; | |
3197 | int ret; | |
3198 | u32 item_size; | |
3199 | ||
3200 | leaf = path->nodes[0]; | |
3201 | item_size = btrfs_item_size_nr(leaf, path->slots[0]); | |
3202 | ret = setup_leaf_for_split(trans, root, path, | |
3203 | item_size + sizeof(struct btrfs_item)); | |
3204 | if (ret) | |
3205 | return ret; | |
3206 | ||
3207 | path->slots[0]++; | |
3208 | ret = setup_items_for_insert(trans, root, path, new_key, &item_size, | |
3209 | item_size, item_size + | |
3210 | sizeof(struct btrfs_item), 1); | |
3211 | BUG_ON(ret); | |
3212 | ||
3213 | leaf = path->nodes[0]; | |
3214 | memcpy_extent_buffer(leaf, | |
3215 | btrfs_item_ptr_offset(leaf, path->slots[0]), | |
3216 | btrfs_item_ptr_offset(leaf, path->slots[0] - 1), | |
3217 | item_size); | |
3218 | return 0; | |
3219 | } | |
3220 | ||
d352ac68 CM |
3221 | /* |
3222 | * make the item pointed to by the path smaller. new_size indicates | |
3223 | * how small to make it, and from_end tells us if we just chop bytes | |
3224 | * off the end of the item or if we shift the item to chop bytes off | |
3225 | * the front. | |
3226 | */ | |
b18c6685 CM |
3227 | int btrfs_truncate_item(struct btrfs_trans_handle *trans, |
3228 | struct btrfs_root *root, | |
3229 | struct btrfs_path *path, | |
179e29e4 | 3230 | u32 new_size, int from_end) |
b18c6685 | 3231 | { |
b18c6685 | 3232 | int slot; |
5f39d397 CM |
3233 | struct extent_buffer *leaf; |
3234 | struct btrfs_item *item; | |
b18c6685 CM |
3235 | u32 nritems; |
3236 | unsigned int data_end; | |
3237 | unsigned int old_data_start; | |
3238 | unsigned int old_size; | |
3239 | unsigned int size_diff; | |
3240 | int i; | |
3241 | ||
5f39d397 | 3242 | leaf = path->nodes[0]; |
179e29e4 CM |
3243 | slot = path->slots[0]; |
3244 | ||
3245 | old_size = btrfs_item_size_nr(leaf, slot); | |
3246 | if (old_size == new_size) | |
3247 | return 0; | |
b18c6685 | 3248 | |
5f39d397 | 3249 | nritems = btrfs_header_nritems(leaf); |
b18c6685 CM |
3250 | data_end = leaf_data_end(root, leaf); |
3251 | ||
5f39d397 | 3252 | old_data_start = btrfs_item_offset_nr(leaf, slot); |
179e29e4 | 3253 | |
b18c6685 CM |
3254 | size_diff = old_size - new_size; |
3255 | ||
3256 | BUG_ON(slot < 0); | |
3257 | BUG_ON(slot >= nritems); | |
3258 | ||
3259 | /* | |
3260 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
3261 | */ | |
3262 | /* first correct the data pointers */ | |
3263 | for (i = slot; i < nritems; i++) { | |
5f39d397 CM |
3264 | u32 ioff; |
3265 | item = btrfs_item_nr(leaf, i); | |
db94535d CM |
3266 | |
3267 | if (!leaf->map_token) { | |
3268 | map_extent_buffer(leaf, (unsigned long)item, | |
3269 | sizeof(struct btrfs_item), | |
3270 | &leaf->map_token, &leaf->kaddr, | |
3271 | &leaf->map_start, &leaf->map_len, | |
3272 | KM_USER1); | |
3273 | } | |
3274 | ||
5f39d397 CM |
3275 | ioff = btrfs_item_offset(leaf, item); |
3276 | btrfs_set_item_offset(leaf, item, ioff + size_diff); | |
b18c6685 | 3277 | } |
db94535d CM |
3278 | |
3279 | if (leaf->map_token) { | |
3280 | unmap_extent_buffer(leaf, leaf->map_token, KM_USER1); | |
3281 | leaf->map_token = NULL; | |
3282 | } | |
3283 | ||
b18c6685 | 3284 | /* shift the data */ |
179e29e4 CM |
3285 | if (from_end) { |
3286 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + | |
3287 | data_end + size_diff, btrfs_leaf_data(leaf) + | |
3288 | data_end, old_data_start + new_size - data_end); | |
3289 | } else { | |
3290 | struct btrfs_disk_key disk_key; | |
3291 | u64 offset; | |
3292 | ||
3293 | btrfs_item_key(leaf, &disk_key, slot); | |
3294 | ||
3295 | if (btrfs_disk_key_type(&disk_key) == BTRFS_EXTENT_DATA_KEY) { | |
3296 | unsigned long ptr; | |
3297 | struct btrfs_file_extent_item *fi; | |
3298 | ||
3299 | fi = btrfs_item_ptr(leaf, slot, | |
3300 | struct btrfs_file_extent_item); | |
3301 | fi = (struct btrfs_file_extent_item *)( | |
3302 | (unsigned long)fi - size_diff); | |
3303 | ||
3304 | if (btrfs_file_extent_type(leaf, fi) == | |
3305 | BTRFS_FILE_EXTENT_INLINE) { | |
3306 | ptr = btrfs_item_ptr_offset(leaf, slot); | |
3307 | memmove_extent_buffer(leaf, ptr, | |
d397712b CM |
3308 | (unsigned long)fi, |
3309 | offsetof(struct btrfs_file_extent_item, | |
179e29e4 CM |
3310 | disk_bytenr)); |
3311 | } | |
3312 | } | |
3313 | ||
3314 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + | |
3315 | data_end + size_diff, btrfs_leaf_data(leaf) + | |
3316 | data_end, old_data_start - data_end); | |
3317 | ||
3318 | offset = btrfs_disk_key_offset(&disk_key); | |
3319 | btrfs_set_disk_key_offset(&disk_key, offset + size_diff); | |
3320 | btrfs_set_item_key(leaf, &disk_key, slot); | |
3321 | if (slot == 0) | |
3322 | fixup_low_keys(trans, root, path, &disk_key, 1); | |
3323 | } | |
5f39d397 CM |
3324 | |
3325 | item = btrfs_item_nr(leaf, slot); | |
3326 | btrfs_set_item_size(leaf, item, new_size); | |
3327 | btrfs_mark_buffer_dirty(leaf); | |
b18c6685 | 3328 | |
5f39d397 CM |
3329 | if (btrfs_leaf_free_space(root, leaf) < 0) { |
3330 | btrfs_print_leaf(root, leaf); | |
b18c6685 | 3331 | BUG(); |
5f39d397 | 3332 | } |
1cd30799 | 3333 | return 0; |
b18c6685 CM |
3334 | } |
3335 | ||
d352ac68 CM |
3336 | /* |
3337 | * make the item pointed to by the path bigger, data_size is the new size. | |
3338 | */ | |
5f39d397 CM |
3339 | int btrfs_extend_item(struct btrfs_trans_handle *trans, |
3340 | struct btrfs_root *root, struct btrfs_path *path, | |
3341 | u32 data_size) | |
6567e837 | 3342 | { |
6567e837 | 3343 | int slot; |
5f39d397 CM |
3344 | struct extent_buffer *leaf; |
3345 | struct btrfs_item *item; | |
6567e837 CM |
3346 | u32 nritems; |
3347 | unsigned int data_end; | |
3348 | unsigned int old_data; | |
3349 | unsigned int old_size; | |
3350 | int i; | |
3351 | ||
5f39d397 | 3352 | leaf = path->nodes[0]; |
6567e837 | 3353 | |
5f39d397 | 3354 | nritems = btrfs_header_nritems(leaf); |
6567e837 CM |
3355 | data_end = leaf_data_end(root, leaf); |
3356 | ||
5f39d397 CM |
3357 | if (btrfs_leaf_free_space(root, leaf) < data_size) { |
3358 | btrfs_print_leaf(root, leaf); | |
6567e837 | 3359 | BUG(); |
5f39d397 | 3360 | } |
6567e837 | 3361 | slot = path->slots[0]; |
5f39d397 | 3362 | old_data = btrfs_item_end_nr(leaf, slot); |
6567e837 CM |
3363 | |
3364 | BUG_ON(slot < 0); | |
3326d1b0 CM |
3365 | if (slot >= nritems) { |
3366 | btrfs_print_leaf(root, leaf); | |
d397712b CM |
3367 | printk(KERN_CRIT "slot %d too large, nritems %d\n", |
3368 | slot, nritems); | |
3326d1b0 CM |
3369 | BUG_ON(1); |
3370 | } | |
6567e837 CM |
3371 | |
3372 | /* | |
3373 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
3374 | */ | |
3375 | /* first correct the data pointers */ | |
3376 | for (i = slot; i < nritems; i++) { | |
5f39d397 CM |
3377 | u32 ioff; |
3378 | item = btrfs_item_nr(leaf, i); | |
db94535d CM |
3379 | |
3380 | if (!leaf->map_token) { | |
3381 | map_extent_buffer(leaf, (unsigned long)item, | |
3382 | sizeof(struct btrfs_item), | |
3383 | &leaf->map_token, &leaf->kaddr, | |
3384 | &leaf->map_start, &leaf->map_len, | |
3385 | KM_USER1); | |
3386 | } | |
5f39d397 CM |
3387 | ioff = btrfs_item_offset(leaf, item); |
3388 | btrfs_set_item_offset(leaf, item, ioff - data_size); | |
6567e837 | 3389 | } |
5f39d397 | 3390 | |
db94535d CM |
3391 | if (leaf->map_token) { |
3392 | unmap_extent_buffer(leaf, leaf->map_token, KM_USER1); | |
3393 | leaf->map_token = NULL; | |
3394 | } | |
3395 | ||
6567e837 | 3396 | /* shift the data */ |
5f39d397 | 3397 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + |
6567e837 CM |
3398 | data_end - data_size, btrfs_leaf_data(leaf) + |
3399 | data_end, old_data - data_end); | |
5f39d397 | 3400 | |
6567e837 | 3401 | data_end = old_data; |
5f39d397 CM |
3402 | old_size = btrfs_item_size_nr(leaf, slot); |
3403 | item = btrfs_item_nr(leaf, slot); | |
3404 | btrfs_set_item_size(leaf, item, old_size + data_size); | |
3405 | btrfs_mark_buffer_dirty(leaf); | |
6567e837 | 3406 | |
5f39d397 CM |
3407 | if (btrfs_leaf_free_space(root, leaf) < 0) { |
3408 | btrfs_print_leaf(root, leaf); | |
6567e837 | 3409 | BUG(); |
5f39d397 | 3410 | } |
1cd30799 | 3411 | return 0; |
6567e837 CM |
3412 | } |
3413 | ||
f3465ca4 JB |
3414 | /* |
3415 | * Given a key and some data, insert items into the tree. | |
3416 | * This does all the path init required, making room in the tree if needed. | |
3417 | * Returns the number of keys that were inserted. | |
3418 | */ | |
3419 | int btrfs_insert_some_items(struct btrfs_trans_handle *trans, | |
3420 | struct btrfs_root *root, | |
3421 | struct btrfs_path *path, | |
3422 | struct btrfs_key *cpu_key, u32 *data_size, | |
3423 | int nr) | |
3424 | { | |
3425 | struct extent_buffer *leaf; | |
3426 | struct btrfs_item *item; | |
3427 | int ret = 0; | |
3428 | int slot; | |
f3465ca4 JB |
3429 | int i; |
3430 | u32 nritems; | |
3431 | u32 total_data = 0; | |
3432 | u32 total_size = 0; | |
3433 | unsigned int data_end; | |
3434 | struct btrfs_disk_key disk_key; | |
3435 | struct btrfs_key found_key; | |
3436 | ||
87b29b20 YZ |
3437 | for (i = 0; i < nr; i++) { |
3438 | if (total_size + data_size[i] + sizeof(struct btrfs_item) > | |
3439 | BTRFS_LEAF_DATA_SIZE(root)) { | |
3440 | break; | |
3441 | nr = i; | |
3442 | } | |
f3465ca4 | 3443 | total_data += data_size[i]; |
87b29b20 YZ |
3444 | total_size += data_size[i] + sizeof(struct btrfs_item); |
3445 | } | |
3446 | BUG_ON(nr == 0); | |
f3465ca4 | 3447 | |
f3465ca4 JB |
3448 | ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1); |
3449 | if (ret == 0) | |
3450 | return -EEXIST; | |
3451 | if (ret < 0) | |
3452 | goto out; | |
3453 | ||
f3465ca4 JB |
3454 | leaf = path->nodes[0]; |
3455 | ||
3456 | nritems = btrfs_header_nritems(leaf); | |
3457 | data_end = leaf_data_end(root, leaf); | |
3458 | ||
3459 | if (btrfs_leaf_free_space(root, leaf) < total_size) { | |
3460 | for (i = nr; i >= 0; i--) { | |
3461 | total_data -= data_size[i]; | |
3462 | total_size -= data_size[i] + sizeof(struct btrfs_item); | |
3463 | if (total_size < btrfs_leaf_free_space(root, leaf)) | |
3464 | break; | |
3465 | } | |
3466 | nr = i; | |
3467 | } | |
3468 | ||
3469 | slot = path->slots[0]; | |
3470 | BUG_ON(slot < 0); | |
3471 | ||
3472 | if (slot != nritems) { | |
3473 | unsigned int old_data = btrfs_item_end_nr(leaf, slot); | |
3474 | ||
3475 | item = btrfs_item_nr(leaf, slot); | |
3476 | btrfs_item_key_to_cpu(leaf, &found_key, slot); | |
3477 | ||
3478 | /* figure out how many keys we can insert in here */ | |
3479 | total_data = data_size[0]; | |
3480 | for (i = 1; i < nr; i++) { | |
5d4f98a2 | 3481 | if (btrfs_comp_cpu_keys(&found_key, cpu_key + i) <= 0) |
f3465ca4 JB |
3482 | break; |
3483 | total_data += data_size[i]; | |
3484 | } | |
3485 | nr = i; | |
3486 | ||
3487 | if (old_data < data_end) { | |
3488 | btrfs_print_leaf(root, leaf); | |
d397712b | 3489 | printk(KERN_CRIT "slot %d old_data %d data_end %d\n", |
f3465ca4 JB |
3490 | slot, old_data, data_end); |
3491 | BUG_ON(1); | |
3492 | } | |
3493 | /* | |
3494 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
3495 | */ | |
3496 | /* first correct the data pointers */ | |
3497 | WARN_ON(leaf->map_token); | |
3498 | for (i = slot; i < nritems; i++) { | |
3499 | u32 ioff; | |
3500 | ||
3501 | item = btrfs_item_nr(leaf, i); | |
3502 | if (!leaf->map_token) { | |
3503 | map_extent_buffer(leaf, (unsigned long)item, | |
3504 | sizeof(struct btrfs_item), | |
3505 | &leaf->map_token, &leaf->kaddr, | |
3506 | &leaf->map_start, &leaf->map_len, | |
3507 | KM_USER1); | |
3508 | } | |
3509 | ||
3510 | ioff = btrfs_item_offset(leaf, item); | |
3511 | btrfs_set_item_offset(leaf, item, ioff - total_data); | |
3512 | } | |
3513 | if (leaf->map_token) { | |
3514 | unmap_extent_buffer(leaf, leaf->map_token, KM_USER1); | |
3515 | leaf->map_token = NULL; | |
3516 | } | |
3517 | ||
3518 | /* shift the items */ | |
3519 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr), | |
3520 | btrfs_item_nr_offset(slot), | |
3521 | (nritems - slot) * sizeof(struct btrfs_item)); | |
3522 | ||
3523 | /* shift the data */ | |
3524 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + | |
3525 | data_end - total_data, btrfs_leaf_data(leaf) + | |
3526 | data_end, old_data - data_end); | |
3527 | data_end = old_data; | |
3528 | } else { | |
3529 | /* | |
3530 | * this sucks but it has to be done, if we are inserting at | |
3531 | * the end of the leaf only insert 1 of the items, since we | |
3532 | * have no way of knowing whats on the next leaf and we'd have | |
3533 | * to drop our current locks to figure it out | |
3534 | */ | |
3535 | nr = 1; | |
3536 | } | |
3537 | ||
3538 | /* setup the item for the new data */ | |
3539 | for (i = 0; i < nr; i++) { | |
3540 | btrfs_cpu_key_to_disk(&disk_key, cpu_key + i); | |
3541 | btrfs_set_item_key(leaf, &disk_key, slot + i); | |
3542 | item = btrfs_item_nr(leaf, slot + i); | |
3543 | btrfs_set_item_offset(leaf, item, data_end - data_size[i]); | |
3544 | data_end -= data_size[i]; | |
3545 | btrfs_set_item_size(leaf, item, data_size[i]); | |
3546 | } | |
3547 | btrfs_set_header_nritems(leaf, nritems + nr); | |
3548 | btrfs_mark_buffer_dirty(leaf); | |
3549 | ||
3550 | ret = 0; | |
3551 | if (slot == 0) { | |
3552 | btrfs_cpu_key_to_disk(&disk_key, cpu_key); | |
3553 | ret = fixup_low_keys(trans, root, path, &disk_key, 1); | |
3554 | } | |
3555 | ||
3556 | if (btrfs_leaf_free_space(root, leaf) < 0) { | |
3557 | btrfs_print_leaf(root, leaf); | |
3558 | BUG(); | |
3559 | } | |
3560 | out: | |
3561 | if (!ret) | |
3562 | ret = nr; | |
3563 | return ret; | |
3564 | } | |
3565 | ||
74123bd7 | 3566 | /* |
44871b1b CM |
3567 | * this is a helper for btrfs_insert_empty_items, the main goal here is |
3568 | * to save stack depth by doing the bulk of the work in a function | |
3569 | * that doesn't call btrfs_search_slot | |
74123bd7 | 3570 | */ |
16cdcec7 MX |
3571 | int setup_items_for_insert(struct btrfs_trans_handle *trans, |
3572 | struct btrfs_root *root, struct btrfs_path *path, | |
3573 | struct btrfs_key *cpu_key, u32 *data_size, | |
3574 | u32 total_data, u32 total_size, int nr) | |
be0e5c09 | 3575 | { |
5f39d397 | 3576 | struct btrfs_item *item; |
9c58309d | 3577 | int i; |
7518a238 | 3578 | u32 nritems; |
be0e5c09 | 3579 | unsigned int data_end; |
e2fa7227 | 3580 | struct btrfs_disk_key disk_key; |
44871b1b CM |
3581 | int ret; |
3582 | struct extent_buffer *leaf; | |
3583 | int slot; | |
e2fa7227 | 3584 | |
5f39d397 | 3585 | leaf = path->nodes[0]; |
44871b1b | 3586 | slot = path->slots[0]; |
74123bd7 | 3587 | |
5f39d397 | 3588 | nritems = btrfs_header_nritems(leaf); |
123abc88 | 3589 | data_end = leaf_data_end(root, leaf); |
eb60ceac | 3590 | |
f25956cc | 3591 | if (btrfs_leaf_free_space(root, leaf) < total_size) { |
3326d1b0 | 3592 | btrfs_print_leaf(root, leaf); |
d397712b | 3593 | printk(KERN_CRIT "not enough freespace need %u have %d\n", |
9c58309d | 3594 | total_size, btrfs_leaf_free_space(root, leaf)); |
be0e5c09 | 3595 | BUG(); |
d4dbff95 | 3596 | } |
5f39d397 | 3597 | |
be0e5c09 | 3598 | if (slot != nritems) { |
5f39d397 | 3599 | unsigned int old_data = btrfs_item_end_nr(leaf, slot); |
be0e5c09 | 3600 | |
5f39d397 CM |
3601 | if (old_data < data_end) { |
3602 | btrfs_print_leaf(root, leaf); | |
d397712b | 3603 | printk(KERN_CRIT "slot %d old_data %d data_end %d\n", |
5f39d397 CM |
3604 | slot, old_data, data_end); |
3605 | BUG_ON(1); | |
3606 | } | |
be0e5c09 CM |
3607 | /* |
3608 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
3609 | */ | |
3610 | /* first correct the data pointers */ | |
db94535d | 3611 | WARN_ON(leaf->map_token); |
0783fcfc | 3612 | for (i = slot; i < nritems; i++) { |
5f39d397 | 3613 | u32 ioff; |
db94535d | 3614 | |
5f39d397 | 3615 | item = btrfs_item_nr(leaf, i); |
db94535d CM |
3616 | if (!leaf->map_token) { |
3617 | map_extent_buffer(leaf, (unsigned long)item, | |
3618 | sizeof(struct btrfs_item), | |
3619 | &leaf->map_token, &leaf->kaddr, | |
3620 | &leaf->map_start, &leaf->map_len, | |
3621 | KM_USER1); | |
3622 | } | |
3623 | ||
5f39d397 | 3624 | ioff = btrfs_item_offset(leaf, item); |
9c58309d | 3625 | btrfs_set_item_offset(leaf, item, ioff - total_data); |
0783fcfc | 3626 | } |
db94535d CM |
3627 | if (leaf->map_token) { |
3628 | unmap_extent_buffer(leaf, leaf->map_token, KM_USER1); | |
3629 | leaf->map_token = NULL; | |
3630 | } | |
be0e5c09 CM |
3631 | |
3632 | /* shift the items */ | |
9c58309d | 3633 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr), |
5f39d397 | 3634 | btrfs_item_nr_offset(slot), |
d6025579 | 3635 | (nritems - slot) * sizeof(struct btrfs_item)); |
be0e5c09 CM |
3636 | |
3637 | /* shift the data */ | |
5f39d397 | 3638 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + |
9c58309d | 3639 | data_end - total_data, btrfs_leaf_data(leaf) + |
d6025579 | 3640 | data_end, old_data - data_end); |
be0e5c09 CM |
3641 | data_end = old_data; |
3642 | } | |
5f39d397 | 3643 | |
62e2749e | 3644 | /* setup the item for the new data */ |
9c58309d CM |
3645 | for (i = 0; i < nr; i++) { |
3646 | btrfs_cpu_key_to_disk(&disk_key, cpu_key + i); | |
3647 | btrfs_set_item_key(leaf, &disk_key, slot + i); | |
3648 | item = btrfs_item_nr(leaf, slot + i); | |
3649 | btrfs_set_item_offset(leaf, item, data_end - data_size[i]); | |
3650 | data_end -= data_size[i]; | |
3651 | btrfs_set_item_size(leaf, item, data_size[i]); | |
3652 | } | |
44871b1b | 3653 | |
9c58309d | 3654 | btrfs_set_header_nritems(leaf, nritems + nr); |
aa5d6bed CM |
3655 | |
3656 | ret = 0; | |
5a01a2e3 CM |
3657 | if (slot == 0) { |
3658 | btrfs_cpu_key_to_disk(&disk_key, cpu_key); | |
e089f05c | 3659 | ret = fixup_low_keys(trans, root, path, &disk_key, 1); |
5a01a2e3 | 3660 | } |
b9473439 CM |
3661 | btrfs_unlock_up_safe(path, 1); |
3662 | btrfs_mark_buffer_dirty(leaf); | |
aa5d6bed | 3663 | |
5f39d397 CM |
3664 | if (btrfs_leaf_free_space(root, leaf) < 0) { |
3665 | btrfs_print_leaf(root, leaf); | |
be0e5c09 | 3666 | BUG(); |
5f39d397 | 3667 | } |
44871b1b CM |
3668 | return ret; |
3669 | } | |
3670 | ||
3671 | /* | |
3672 | * Given a key and some data, insert items into the tree. | |
3673 | * This does all the path init required, making room in the tree if needed. | |
3674 | */ | |
3675 | int btrfs_insert_empty_items(struct btrfs_trans_handle *trans, | |
3676 | struct btrfs_root *root, | |
3677 | struct btrfs_path *path, | |
3678 | struct btrfs_key *cpu_key, u32 *data_size, | |
3679 | int nr) | |
3680 | { | |
44871b1b CM |
3681 | int ret = 0; |
3682 | int slot; | |
3683 | int i; | |
3684 | u32 total_size = 0; | |
3685 | u32 total_data = 0; | |
3686 | ||
3687 | for (i = 0; i < nr; i++) | |
3688 | total_data += data_size[i]; | |
3689 | ||
3690 | total_size = total_data + (nr * sizeof(struct btrfs_item)); | |
3691 | ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1); | |
3692 | if (ret == 0) | |
3693 | return -EEXIST; | |
3694 | if (ret < 0) | |
3695 | goto out; | |
3696 | ||
44871b1b CM |
3697 | slot = path->slots[0]; |
3698 | BUG_ON(slot < 0); | |
3699 | ||
3700 | ret = setup_items_for_insert(trans, root, path, cpu_key, data_size, | |
3701 | total_data, total_size, nr); | |
3702 | ||
ed2ff2cb | 3703 | out: |
62e2749e CM |
3704 | return ret; |
3705 | } | |
3706 | ||
3707 | /* | |
3708 | * Given a key and some data, insert an item into the tree. | |
3709 | * This does all the path init required, making room in the tree if needed. | |
3710 | */ | |
e089f05c CM |
3711 | int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root |
3712 | *root, struct btrfs_key *cpu_key, void *data, u32 | |
3713 | data_size) | |
62e2749e CM |
3714 | { |
3715 | int ret = 0; | |
2c90e5d6 | 3716 | struct btrfs_path *path; |
5f39d397 CM |
3717 | struct extent_buffer *leaf; |
3718 | unsigned long ptr; | |
62e2749e | 3719 | |
2c90e5d6 | 3720 | path = btrfs_alloc_path(); |
db5b493a TI |
3721 | if (!path) |
3722 | return -ENOMEM; | |
2c90e5d6 | 3723 | ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size); |
62e2749e | 3724 | if (!ret) { |
5f39d397 CM |
3725 | leaf = path->nodes[0]; |
3726 | ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); | |
3727 | write_extent_buffer(leaf, data, ptr, data_size); | |
3728 | btrfs_mark_buffer_dirty(leaf); | |
62e2749e | 3729 | } |
2c90e5d6 | 3730 | btrfs_free_path(path); |
aa5d6bed | 3731 | return ret; |
be0e5c09 CM |
3732 | } |
3733 | ||
74123bd7 | 3734 | /* |
5de08d7d | 3735 | * delete the pointer from a given node. |
74123bd7 | 3736 | * |
d352ac68 CM |
3737 | * the tree should have been previously balanced so the deletion does not |
3738 | * empty a node. | |
74123bd7 | 3739 | */ |
e089f05c CM |
3740 | static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
3741 | struct btrfs_path *path, int level, int slot) | |
be0e5c09 | 3742 | { |
5f39d397 | 3743 | struct extent_buffer *parent = path->nodes[level]; |
7518a238 | 3744 | u32 nritems; |
aa5d6bed | 3745 | int ret = 0; |
bb803951 | 3746 | int wret; |
be0e5c09 | 3747 | |
5f39d397 | 3748 | nritems = btrfs_header_nritems(parent); |
d397712b | 3749 | if (slot != nritems - 1) { |
5f39d397 CM |
3750 | memmove_extent_buffer(parent, |
3751 | btrfs_node_key_ptr_offset(slot), | |
3752 | btrfs_node_key_ptr_offset(slot + 1), | |
d6025579 CM |
3753 | sizeof(struct btrfs_key_ptr) * |
3754 | (nritems - slot - 1)); | |
bb803951 | 3755 | } |
7518a238 | 3756 | nritems--; |
5f39d397 | 3757 | btrfs_set_header_nritems(parent, nritems); |
7518a238 | 3758 | if (nritems == 0 && parent == root->node) { |
5f39d397 | 3759 | BUG_ON(btrfs_header_level(root->node) != 1); |
bb803951 | 3760 | /* just turn the root into a leaf and break */ |
5f39d397 | 3761 | btrfs_set_header_level(root->node, 0); |
bb803951 | 3762 | } else if (slot == 0) { |
5f39d397 CM |
3763 | struct btrfs_disk_key disk_key; |
3764 | ||
3765 | btrfs_node_key(parent, &disk_key, 0); | |
3766 | wret = fixup_low_keys(trans, root, path, &disk_key, level + 1); | |
0f70abe2 CM |
3767 | if (wret) |
3768 | ret = wret; | |
be0e5c09 | 3769 | } |
d6025579 | 3770 | btrfs_mark_buffer_dirty(parent); |
aa5d6bed | 3771 | return ret; |
be0e5c09 CM |
3772 | } |
3773 | ||
323ac95b CM |
3774 | /* |
3775 | * a helper function to delete the leaf pointed to by path->slots[1] and | |
5d4f98a2 | 3776 | * path->nodes[1]. |
323ac95b CM |
3777 | * |
3778 | * This deletes the pointer in path->nodes[1] and frees the leaf | |
3779 | * block extent. zero is returned if it all worked out, < 0 otherwise. | |
3780 | * | |
3781 | * The path must have already been setup for deleting the leaf, including | |
3782 | * all the proper balancing. path->nodes[1] must be locked. | |
3783 | */ | |
5d4f98a2 YZ |
3784 | static noinline int btrfs_del_leaf(struct btrfs_trans_handle *trans, |
3785 | struct btrfs_root *root, | |
3786 | struct btrfs_path *path, | |
3787 | struct extent_buffer *leaf) | |
323ac95b CM |
3788 | { |
3789 | int ret; | |
323ac95b | 3790 | |
5d4f98a2 | 3791 | WARN_ON(btrfs_header_generation(leaf) != trans->transid); |
323ac95b CM |
3792 | ret = del_ptr(trans, root, path, 1, path->slots[1]); |
3793 | if (ret) | |
3794 | return ret; | |
3795 | ||
4d081c41 CM |
3796 | /* |
3797 | * btrfs_free_extent is expensive, we want to make sure we | |
3798 | * aren't holding any locks when we call it | |
3799 | */ | |
3800 | btrfs_unlock_up_safe(path, 0); | |
3801 | ||
f0486c68 YZ |
3802 | root_sub_used(root, leaf->len); |
3803 | ||
3804 | btrfs_free_tree_block(trans, root, leaf, 0, 1); | |
3805 | return 0; | |
323ac95b | 3806 | } |
74123bd7 CM |
3807 | /* |
3808 | * delete the item at the leaf level in path. If that empties | |
3809 | * the leaf, remove it from the tree | |
3810 | */ | |
85e21bac CM |
3811 | int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
3812 | struct btrfs_path *path, int slot, int nr) | |
be0e5c09 | 3813 | { |
5f39d397 CM |
3814 | struct extent_buffer *leaf; |
3815 | struct btrfs_item *item; | |
85e21bac CM |
3816 | int last_off; |
3817 | int dsize = 0; | |
aa5d6bed CM |
3818 | int ret = 0; |
3819 | int wret; | |
85e21bac | 3820 | int i; |
7518a238 | 3821 | u32 nritems; |
be0e5c09 | 3822 | |
5f39d397 | 3823 | leaf = path->nodes[0]; |
85e21bac CM |
3824 | last_off = btrfs_item_offset_nr(leaf, slot + nr - 1); |
3825 | ||
3826 | for (i = 0; i < nr; i++) | |
3827 | dsize += btrfs_item_size_nr(leaf, slot + i); | |
3828 | ||
5f39d397 | 3829 | nritems = btrfs_header_nritems(leaf); |
be0e5c09 | 3830 | |
85e21bac | 3831 | if (slot + nr != nritems) { |
123abc88 | 3832 | int data_end = leaf_data_end(root, leaf); |
5f39d397 CM |
3833 | |
3834 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + | |
d6025579 CM |
3835 | data_end + dsize, |
3836 | btrfs_leaf_data(leaf) + data_end, | |
85e21bac | 3837 | last_off - data_end); |
5f39d397 | 3838 | |
85e21bac | 3839 | for (i = slot + nr; i < nritems; i++) { |
5f39d397 | 3840 | u32 ioff; |
db94535d | 3841 | |
5f39d397 | 3842 | item = btrfs_item_nr(leaf, i); |
db94535d CM |
3843 | if (!leaf->map_token) { |
3844 | map_extent_buffer(leaf, (unsigned long)item, | |
3845 | sizeof(struct btrfs_item), | |
3846 | &leaf->map_token, &leaf->kaddr, | |
3847 | &leaf->map_start, &leaf->map_len, | |
3848 | KM_USER1); | |
3849 | } | |
5f39d397 CM |
3850 | ioff = btrfs_item_offset(leaf, item); |
3851 | btrfs_set_item_offset(leaf, item, ioff + dsize); | |
0783fcfc | 3852 | } |
db94535d CM |
3853 | |
3854 | if (leaf->map_token) { | |
3855 | unmap_extent_buffer(leaf, leaf->map_token, KM_USER1); | |
3856 | leaf->map_token = NULL; | |
3857 | } | |
3858 | ||
5f39d397 | 3859 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot), |
85e21bac | 3860 | btrfs_item_nr_offset(slot + nr), |
d6025579 | 3861 | sizeof(struct btrfs_item) * |
85e21bac | 3862 | (nritems - slot - nr)); |
be0e5c09 | 3863 | } |
85e21bac CM |
3864 | btrfs_set_header_nritems(leaf, nritems - nr); |
3865 | nritems -= nr; | |
5f39d397 | 3866 | |
74123bd7 | 3867 | /* delete the leaf if we've emptied it */ |
7518a238 | 3868 | if (nritems == 0) { |
5f39d397 CM |
3869 | if (leaf == root->node) { |
3870 | btrfs_set_header_level(leaf, 0); | |
9a8dd150 | 3871 | } else { |
f0486c68 YZ |
3872 | btrfs_set_path_blocking(path); |
3873 | clean_tree_block(trans, root, leaf); | |
5d4f98a2 | 3874 | ret = btrfs_del_leaf(trans, root, path, leaf); |
323ac95b | 3875 | BUG_ON(ret); |
9a8dd150 | 3876 | } |
be0e5c09 | 3877 | } else { |
7518a238 | 3878 | int used = leaf_space_used(leaf, 0, nritems); |
aa5d6bed | 3879 | if (slot == 0) { |
5f39d397 CM |
3880 | struct btrfs_disk_key disk_key; |
3881 | ||
3882 | btrfs_item_key(leaf, &disk_key, 0); | |
e089f05c | 3883 | wret = fixup_low_keys(trans, root, path, |
5f39d397 | 3884 | &disk_key, 1); |
aa5d6bed CM |
3885 | if (wret) |
3886 | ret = wret; | |
3887 | } | |
aa5d6bed | 3888 | |
74123bd7 | 3889 | /* delete the leaf if it is mostly empty */ |
d717aa1d | 3890 | if (used < BTRFS_LEAF_DATA_SIZE(root) / 3) { |
be0e5c09 CM |
3891 | /* push_leaf_left fixes the path. |
3892 | * make sure the path still points to our leaf | |
3893 | * for possible call to del_ptr below | |
3894 | */ | |
4920c9ac | 3895 | slot = path->slots[1]; |
5f39d397 CM |
3896 | extent_buffer_get(leaf); |
3897 | ||
b9473439 | 3898 | btrfs_set_path_blocking(path); |
99d8f83c CM |
3899 | wret = push_leaf_left(trans, root, path, 1, 1, |
3900 | 1, (u32)-1); | |
54aa1f4d | 3901 | if (wret < 0 && wret != -ENOSPC) |
aa5d6bed | 3902 | ret = wret; |
5f39d397 CM |
3903 | |
3904 | if (path->nodes[0] == leaf && | |
3905 | btrfs_header_nritems(leaf)) { | |
99d8f83c CM |
3906 | wret = push_leaf_right(trans, root, path, 1, |
3907 | 1, 1, 0); | |
54aa1f4d | 3908 | if (wret < 0 && wret != -ENOSPC) |
aa5d6bed CM |
3909 | ret = wret; |
3910 | } | |
5f39d397 CM |
3911 | |
3912 | if (btrfs_header_nritems(leaf) == 0) { | |
323ac95b | 3913 | path->slots[1] = slot; |
5d4f98a2 | 3914 | ret = btrfs_del_leaf(trans, root, path, leaf); |
323ac95b | 3915 | BUG_ON(ret); |
5f39d397 | 3916 | free_extent_buffer(leaf); |
5de08d7d | 3917 | } else { |
925baedd CM |
3918 | /* if we're still in the path, make sure |
3919 | * we're dirty. Otherwise, one of the | |
3920 | * push_leaf functions must have already | |
3921 | * dirtied this buffer | |
3922 | */ | |
3923 | if (path->nodes[0] == leaf) | |
3924 | btrfs_mark_buffer_dirty(leaf); | |
5f39d397 | 3925 | free_extent_buffer(leaf); |
be0e5c09 | 3926 | } |
d5719762 | 3927 | } else { |
5f39d397 | 3928 | btrfs_mark_buffer_dirty(leaf); |
be0e5c09 CM |
3929 | } |
3930 | } | |
aa5d6bed | 3931 | return ret; |
be0e5c09 CM |
3932 | } |
3933 | ||
7bb86316 | 3934 | /* |
925baedd | 3935 | * search the tree again to find a leaf with lesser keys |
7bb86316 CM |
3936 | * returns 0 if it found something or 1 if there are no lesser leaves. |
3937 | * returns < 0 on io errors. | |
d352ac68 CM |
3938 | * |
3939 | * This may release the path, and so you may lose any locks held at the | |
3940 | * time you call it. | |
7bb86316 CM |
3941 | */ |
3942 | int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path) | |
3943 | { | |
925baedd CM |
3944 | struct btrfs_key key; |
3945 | struct btrfs_disk_key found_key; | |
3946 | int ret; | |
7bb86316 | 3947 | |
925baedd | 3948 | btrfs_item_key_to_cpu(path->nodes[0], &key, 0); |
7bb86316 | 3949 | |
925baedd CM |
3950 | if (key.offset > 0) |
3951 | key.offset--; | |
3952 | else if (key.type > 0) | |
3953 | key.type--; | |
3954 | else if (key.objectid > 0) | |
3955 | key.objectid--; | |
3956 | else | |
3957 | return 1; | |
7bb86316 | 3958 | |
b3b4aa74 | 3959 | btrfs_release_path(path); |
925baedd CM |
3960 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
3961 | if (ret < 0) | |
3962 | return ret; | |
3963 | btrfs_item_key(path->nodes[0], &found_key, 0); | |
3964 | ret = comp_keys(&found_key, &key); | |
3965 | if (ret < 0) | |
3966 | return 0; | |
3967 | return 1; | |
7bb86316 CM |
3968 | } |
3969 | ||
3f157a2f CM |
3970 | /* |
3971 | * A helper function to walk down the tree starting at min_key, and looking | |
3972 | * for nodes or leaves that are either in cache or have a minimum | |
d352ac68 | 3973 | * transaction id. This is used by the btree defrag code, and tree logging |
3f157a2f CM |
3974 | * |
3975 | * This does not cow, but it does stuff the starting key it finds back | |
3976 | * into min_key, so you can call btrfs_search_slot with cow=1 on the | |
3977 | * key and get a writable path. | |
3978 | * | |
3979 | * This does lock as it descends, and path->keep_locks should be set | |
3980 | * to 1 by the caller. | |
3981 | * | |
3982 | * This honors path->lowest_level to prevent descent past a given level | |
3983 | * of the tree. | |
3984 | * | |
d352ac68 CM |
3985 | * min_trans indicates the oldest transaction that you are interested |
3986 | * in walking through. Any nodes or leaves older than min_trans are | |
3987 | * skipped over (without reading them). | |
3988 | * | |
3f157a2f CM |
3989 | * returns zero if something useful was found, < 0 on error and 1 if there |
3990 | * was nothing in the tree that matched the search criteria. | |
3991 | */ | |
3992 | int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key, | |
e02119d5 | 3993 | struct btrfs_key *max_key, |
3f157a2f CM |
3994 | struct btrfs_path *path, int cache_only, |
3995 | u64 min_trans) | |
3996 | { | |
3997 | struct extent_buffer *cur; | |
3998 | struct btrfs_key found_key; | |
3999 | int slot; | |
9652480b | 4000 | int sret; |
3f157a2f CM |
4001 | u32 nritems; |
4002 | int level; | |
4003 | int ret = 1; | |
4004 | ||
934d375b | 4005 | WARN_ON(!path->keep_locks); |
3f157a2f CM |
4006 | again: |
4007 | cur = btrfs_lock_root_node(root); | |
4008 | level = btrfs_header_level(cur); | |
e02119d5 | 4009 | WARN_ON(path->nodes[level]); |
3f157a2f CM |
4010 | path->nodes[level] = cur; |
4011 | path->locks[level] = 1; | |
4012 | ||
4013 | if (btrfs_header_generation(cur) < min_trans) { | |
4014 | ret = 1; | |
4015 | goto out; | |
4016 | } | |
d397712b | 4017 | while (1) { |
3f157a2f CM |
4018 | nritems = btrfs_header_nritems(cur); |
4019 | level = btrfs_header_level(cur); | |
9652480b | 4020 | sret = bin_search(cur, min_key, level, &slot); |
3f157a2f | 4021 | |
323ac95b CM |
4022 | /* at the lowest level, we're done, setup the path and exit */ |
4023 | if (level == path->lowest_level) { | |
e02119d5 CM |
4024 | if (slot >= nritems) |
4025 | goto find_next_key; | |
3f157a2f CM |
4026 | ret = 0; |
4027 | path->slots[level] = slot; | |
4028 | btrfs_item_key_to_cpu(cur, &found_key, slot); | |
4029 | goto out; | |
4030 | } | |
9652480b Y |
4031 | if (sret && slot > 0) |
4032 | slot--; | |
3f157a2f CM |
4033 | /* |
4034 | * check this node pointer against the cache_only and | |
4035 | * min_trans parameters. If it isn't in cache or is too | |
4036 | * old, skip to the next one. | |
4037 | */ | |
d397712b | 4038 | while (slot < nritems) { |
3f157a2f CM |
4039 | u64 blockptr; |
4040 | u64 gen; | |
4041 | struct extent_buffer *tmp; | |
e02119d5 CM |
4042 | struct btrfs_disk_key disk_key; |
4043 | ||
3f157a2f CM |
4044 | blockptr = btrfs_node_blockptr(cur, slot); |
4045 | gen = btrfs_node_ptr_generation(cur, slot); | |
4046 | if (gen < min_trans) { | |
4047 | slot++; | |
4048 | continue; | |
4049 | } | |
4050 | if (!cache_only) | |
4051 | break; | |
4052 | ||
e02119d5 CM |
4053 | if (max_key) { |
4054 | btrfs_node_key(cur, &disk_key, slot); | |
4055 | if (comp_keys(&disk_key, max_key) >= 0) { | |
4056 | ret = 1; | |
4057 | goto out; | |
4058 | } | |
4059 | } | |
4060 | ||
3f157a2f CM |
4061 | tmp = btrfs_find_tree_block(root, blockptr, |
4062 | btrfs_level_size(root, level - 1)); | |
4063 | ||
4064 | if (tmp && btrfs_buffer_uptodate(tmp, gen)) { | |
4065 | free_extent_buffer(tmp); | |
4066 | break; | |
4067 | } | |
4068 | if (tmp) | |
4069 | free_extent_buffer(tmp); | |
4070 | slot++; | |
4071 | } | |
e02119d5 | 4072 | find_next_key: |
3f157a2f CM |
4073 | /* |
4074 | * we didn't find a candidate key in this node, walk forward | |
4075 | * and find another one | |
4076 | */ | |
4077 | if (slot >= nritems) { | |
e02119d5 | 4078 | path->slots[level] = slot; |
b4ce94de | 4079 | btrfs_set_path_blocking(path); |
e02119d5 | 4080 | sret = btrfs_find_next_key(root, path, min_key, level, |
3f157a2f | 4081 | cache_only, min_trans); |
e02119d5 | 4082 | if (sret == 0) { |
b3b4aa74 | 4083 | btrfs_release_path(path); |
3f157a2f CM |
4084 | goto again; |
4085 | } else { | |
4086 | goto out; | |
4087 | } | |
4088 | } | |
4089 | /* save our key for returning back */ | |
4090 | btrfs_node_key_to_cpu(cur, &found_key, slot); | |
4091 | path->slots[level] = slot; | |
4092 | if (level == path->lowest_level) { | |
4093 | ret = 0; | |
4094 | unlock_up(path, level, 1); | |
4095 | goto out; | |
4096 | } | |
b4ce94de | 4097 | btrfs_set_path_blocking(path); |
3f157a2f | 4098 | cur = read_node_slot(root, cur, slot); |
97d9a8a4 | 4099 | BUG_ON(!cur); |
3f157a2f CM |
4100 | |
4101 | btrfs_tree_lock(cur); | |
b4ce94de | 4102 | |
3f157a2f CM |
4103 | path->locks[level - 1] = 1; |
4104 | path->nodes[level - 1] = cur; | |
4105 | unlock_up(path, level, 1); | |
4008c04a | 4106 | btrfs_clear_path_blocking(path, NULL); |
3f157a2f CM |
4107 | } |
4108 | out: | |
4109 | if (ret == 0) | |
4110 | memcpy(min_key, &found_key, sizeof(found_key)); | |
b4ce94de | 4111 | btrfs_set_path_blocking(path); |
3f157a2f CM |
4112 | return ret; |
4113 | } | |
4114 | ||
4115 | /* | |
4116 | * this is similar to btrfs_next_leaf, but does not try to preserve | |
4117 | * and fixup the path. It looks for and returns the next key in the | |
4118 | * tree based on the current path and the cache_only and min_trans | |
4119 | * parameters. | |
4120 | * | |
4121 | * 0 is returned if another key is found, < 0 if there are any errors | |
4122 | * and 1 is returned if there are no higher keys in the tree | |
4123 | * | |
4124 | * path->keep_locks should be set to 1 on the search made before | |
4125 | * calling this function. | |
4126 | */ | |
e7a84565 | 4127 | int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path, |
33c66f43 | 4128 | struct btrfs_key *key, int level, |
3f157a2f | 4129 | int cache_only, u64 min_trans) |
e7a84565 | 4130 | { |
e7a84565 CM |
4131 | int slot; |
4132 | struct extent_buffer *c; | |
4133 | ||
934d375b | 4134 | WARN_ON(!path->keep_locks); |
d397712b | 4135 | while (level < BTRFS_MAX_LEVEL) { |
e7a84565 CM |
4136 | if (!path->nodes[level]) |
4137 | return 1; | |
4138 | ||
4139 | slot = path->slots[level] + 1; | |
4140 | c = path->nodes[level]; | |
3f157a2f | 4141 | next: |
e7a84565 | 4142 | if (slot >= btrfs_header_nritems(c)) { |
33c66f43 YZ |
4143 | int ret; |
4144 | int orig_lowest; | |
4145 | struct btrfs_key cur_key; | |
4146 | if (level + 1 >= BTRFS_MAX_LEVEL || | |
4147 | !path->nodes[level + 1]) | |
e7a84565 | 4148 | return 1; |
33c66f43 YZ |
4149 | |
4150 | if (path->locks[level + 1]) { | |
4151 | level++; | |
4152 | continue; | |
4153 | } | |
4154 | ||
4155 | slot = btrfs_header_nritems(c) - 1; | |
4156 | if (level == 0) | |
4157 | btrfs_item_key_to_cpu(c, &cur_key, slot); | |
4158 | else | |
4159 | btrfs_node_key_to_cpu(c, &cur_key, slot); | |
4160 | ||
4161 | orig_lowest = path->lowest_level; | |
b3b4aa74 | 4162 | btrfs_release_path(path); |
33c66f43 YZ |
4163 | path->lowest_level = level; |
4164 | ret = btrfs_search_slot(NULL, root, &cur_key, path, | |
4165 | 0, 0); | |
4166 | path->lowest_level = orig_lowest; | |
4167 | if (ret < 0) | |
4168 | return ret; | |
4169 | ||
4170 | c = path->nodes[level]; | |
4171 | slot = path->slots[level]; | |
4172 | if (ret == 0) | |
4173 | slot++; | |
4174 | goto next; | |
e7a84565 | 4175 | } |
33c66f43 | 4176 | |
e7a84565 CM |
4177 | if (level == 0) |
4178 | btrfs_item_key_to_cpu(c, key, slot); | |
3f157a2f CM |
4179 | else { |
4180 | u64 blockptr = btrfs_node_blockptr(c, slot); | |
4181 | u64 gen = btrfs_node_ptr_generation(c, slot); | |
4182 | ||
4183 | if (cache_only) { | |
4184 | struct extent_buffer *cur; | |
4185 | cur = btrfs_find_tree_block(root, blockptr, | |
4186 | btrfs_level_size(root, level - 1)); | |
4187 | if (!cur || !btrfs_buffer_uptodate(cur, gen)) { | |
4188 | slot++; | |
4189 | if (cur) | |
4190 | free_extent_buffer(cur); | |
4191 | goto next; | |
4192 | } | |
4193 | free_extent_buffer(cur); | |
4194 | } | |
4195 | if (gen < min_trans) { | |
4196 | slot++; | |
4197 | goto next; | |
4198 | } | |
e7a84565 | 4199 | btrfs_node_key_to_cpu(c, key, slot); |
3f157a2f | 4200 | } |
e7a84565 CM |
4201 | return 0; |
4202 | } | |
4203 | return 1; | |
4204 | } | |
4205 | ||
97571fd0 | 4206 | /* |
925baedd | 4207 | * search the tree again to find a leaf with greater keys |
0f70abe2 CM |
4208 | * returns 0 if it found something or 1 if there are no greater leaves. |
4209 | * returns < 0 on io errors. | |
97571fd0 | 4210 | */ |
234b63a0 | 4211 | int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path) |
d97e63b6 CM |
4212 | { |
4213 | int slot; | |
8e73f275 | 4214 | int level; |
5f39d397 | 4215 | struct extent_buffer *c; |
8e73f275 | 4216 | struct extent_buffer *next; |
925baedd CM |
4217 | struct btrfs_key key; |
4218 | u32 nritems; | |
4219 | int ret; | |
8e73f275 CM |
4220 | int old_spinning = path->leave_spinning; |
4221 | int force_blocking = 0; | |
925baedd CM |
4222 | |
4223 | nritems = btrfs_header_nritems(path->nodes[0]); | |
d397712b | 4224 | if (nritems == 0) |
925baedd | 4225 | return 1; |
925baedd | 4226 | |
8e73f275 CM |
4227 | /* |
4228 | * we take the blocks in an order that upsets lockdep. Using | |
4229 | * blocking mode is the only way around it. | |
4230 | */ | |
4231 | #ifdef CONFIG_DEBUG_LOCK_ALLOC | |
4232 | force_blocking = 1; | |
4233 | #endif | |
925baedd | 4234 | |
8e73f275 CM |
4235 | btrfs_item_key_to_cpu(path->nodes[0], &key, nritems - 1); |
4236 | again: | |
4237 | level = 1; | |
4238 | next = NULL; | |
b3b4aa74 | 4239 | btrfs_release_path(path); |
8e73f275 | 4240 | |
a2135011 | 4241 | path->keep_locks = 1; |
8e73f275 CM |
4242 | |
4243 | if (!force_blocking) | |
4244 | path->leave_spinning = 1; | |
4245 | ||
925baedd CM |
4246 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
4247 | path->keep_locks = 0; | |
4248 | ||
4249 | if (ret < 0) | |
4250 | return ret; | |
4251 | ||
a2135011 | 4252 | nritems = btrfs_header_nritems(path->nodes[0]); |
168fd7d2 CM |
4253 | /* |
4254 | * by releasing the path above we dropped all our locks. A balance | |
4255 | * could have added more items next to the key that used to be | |
4256 | * at the very end of the block. So, check again here and | |
4257 | * advance the path if there are now more items available. | |
4258 | */ | |
a2135011 | 4259 | if (nritems > 0 && path->slots[0] < nritems - 1) { |
e457afec YZ |
4260 | if (ret == 0) |
4261 | path->slots[0]++; | |
8e73f275 | 4262 | ret = 0; |
925baedd CM |
4263 | goto done; |
4264 | } | |
d97e63b6 | 4265 | |
d397712b | 4266 | while (level < BTRFS_MAX_LEVEL) { |
8e73f275 CM |
4267 | if (!path->nodes[level]) { |
4268 | ret = 1; | |
4269 | goto done; | |
4270 | } | |
5f39d397 | 4271 | |
d97e63b6 CM |
4272 | slot = path->slots[level] + 1; |
4273 | c = path->nodes[level]; | |
5f39d397 | 4274 | if (slot >= btrfs_header_nritems(c)) { |
d97e63b6 | 4275 | level++; |
8e73f275 CM |
4276 | if (level == BTRFS_MAX_LEVEL) { |
4277 | ret = 1; | |
4278 | goto done; | |
4279 | } | |
d97e63b6 CM |
4280 | continue; |
4281 | } | |
5f39d397 | 4282 | |
925baedd CM |
4283 | if (next) { |
4284 | btrfs_tree_unlock(next); | |
5f39d397 | 4285 | free_extent_buffer(next); |
925baedd | 4286 | } |
5f39d397 | 4287 | |
8e73f275 CM |
4288 | next = c; |
4289 | ret = read_block_for_search(NULL, root, path, &next, level, | |
4290 | slot, &key); | |
4291 | if (ret == -EAGAIN) | |
4292 | goto again; | |
5f39d397 | 4293 | |
76a05b35 | 4294 | if (ret < 0) { |
b3b4aa74 | 4295 | btrfs_release_path(path); |
76a05b35 CM |
4296 | goto done; |
4297 | } | |
4298 | ||
5cd57b2c | 4299 | if (!path->skip_locking) { |
8e73f275 CM |
4300 | ret = btrfs_try_spin_lock(next); |
4301 | if (!ret) { | |
4302 | btrfs_set_path_blocking(path); | |
4303 | btrfs_tree_lock(next); | |
4304 | if (!force_blocking) | |
4305 | btrfs_clear_path_blocking(path, next); | |
4306 | } | |
4307 | if (force_blocking) | |
4308 | btrfs_set_lock_blocking(next); | |
5cd57b2c | 4309 | } |
d97e63b6 CM |
4310 | break; |
4311 | } | |
4312 | path->slots[level] = slot; | |
d397712b | 4313 | while (1) { |
d97e63b6 CM |
4314 | level--; |
4315 | c = path->nodes[level]; | |
925baedd CM |
4316 | if (path->locks[level]) |
4317 | btrfs_tree_unlock(c); | |
8e73f275 | 4318 | |
5f39d397 | 4319 | free_extent_buffer(c); |
d97e63b6 CM |
4320 | path->nodes[level] = next; |
4321 | path->slots[level] = 0; | |
a74a4b97 CM |
4322 | if (!path->skip_locking) |
4323 | path->locks[level] = 1; | |
8e73f275 | 4324 | |
d97e63b6 CM |
4325 | if (!level) |
4326 | break; | |
b4ce94de | 4327 | |
8e73f275 CM |
4328 | ret = read_block_for_search(NULL, root, path, &next, level, |
4329 | 0, &key); | |
4330 | if (ret == -EAGAIN) | |
4331 | goto again; | |
4332 | ||
76a05b35 | 4333 | if (ret < 0) { |
b3b4aa74 | 4334 | btrfs_release_path(path); |
76a05b35 CM |
4335 | goto done; |
4336 | } | |
4337 | ||
5cd57b2c | 4338 | if (!path->skip_locking) { |
b9447ef8 | 4339 | btrfs_assert_tree_locked(path->nodes[level]); |
8e73f275 CM |
4340 | ret = btrfs_try_spin_lock(next); |
4341 | if (!ret) { | |
4342 | btrfs_set_path_blocking(path); | |
4343 | btrfs_tree_lock(next); | |
4344 | if (!force_blocking) | |
4345 | btrfs_clear_path_blocking(path, next); | |
4346 | } | |
4347 | if (force_blocking) | |
4348 | btrfs_set_lock_blocking(next); | |
5cd57b2c | 4349 | } |
d97e63b6 | 4350 | } |
8e73f275 | 4351 | ret = 0; |
925baedd CM |
4352 | done: |
4353 | unlock_up(path, 0, 1); | |
8e73f275 CM |
4354 | path->leave_spinning = old_spinning; |
4355 | if (!old_spinning) | |
4356 | btrfs_set_path_blocking(path); | |
4357 | ||
4358 | return ret; | |
d97e63b6 | 4359 | } |
0b86a832 | 4360 | |
3f157a2f CM |
4361 | /* |
4362 | * this uses btrfs_prev_leaf to walk backwards in the tree, and keeps | |
4363 | * searching until it gets past min_objectid or finds an item of 'type' | |
4364 | * | |
4365 | * returns 0 if something is found, 1 if nothing was found and < 0 on error | |
4366 | */ | |
0b86a832 CM |
4367 | int btrfs_previous_item(struct btrfs_root *root, |
4368 | struct btrfs_path *path, u64 min_objectid, | |
4369 | int type) | |
4370 | { | |
4371 | struct btrfs_key found_key; | |
4372 | struct extent_buffer *leaf; | |
e02119d5 | 4373 | u32 nritems; |
0b86a832 CM |
4374 | int ret; |
4375 | ||
d397712b | 4376 | while (1) { |
0b86a832 | 4377 | if (path->slots[0] == 0) { |
b4ce94de | 4378 | btrfs_set_path_blocking(path); |
0b86a832 CM |
4379 | ret = btrfs_prev_leaf(root, path); |
4380 | if (ret != 0) | |
4381 | return ret; | |
4382 | } else { | |
4383 | path->slots[0]--; | |
4384 | } | |
4385 | leaf = path->nodes[0]; | |
e02119d5 CM |
4386 | nritems = btrfs_header_nritems(leaf); |
4387 | if (nritems == 0) | |
4388 | return 1; | |
4389 | if (path->slots[0] == nritems) | |
4390 | path->slots[0]--; | |
4391 | ||
0b86a832 | 4392 | btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); |
e02119d5 CM |
4393 | if (found_key.objectid < min_objectid) |
4394 | break; | |
0a4eefbb YZ |
4395 | if (found_key.type == type) |
4396 | return 0; | |
e02119d5 CM |
4397 | if (found_key.objectid == min_objectid && |
4398 | found_key.type < type) | |
4399 | break; | |
0b86a832 CM |
4400 | } |
4401 | return 1; | |
4402 | } |