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6cbd5570 | 1 | /* |
d352ac68 | 2 | * Copyright (C) 2007,2008 Oracle. All rights reserved. |
6cbd5570 CM |
3 | * |
4 | * This program is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU General Public | |
6 | * License v2 as published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, | |
9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
11 | * General Public License for more details. | |
12 | * | |
13 | * You should have received a copy of the GNU General Public | |
14 | * License along with this program; if not, write to the | |
15 | * Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
16 | * Boston, MA 021110-1307, USA. | |
17 | */ | |
18 | ||
a6b6e75e | 19 | #include <linux/sched.h> |
5a0e3ad6 | 20 | #include <linux/slab.h> |
eb60ceac CM |
21 | #include "ctree.h" |
22 | #include "disk-io.h" | |
7f5c1516 | 23 | #include "transaction.h" |
5f39d397 | 24 | #include "print-tree.h" |
925baedd | 25 | #include "locking.h" |
9a8dd150 | 26 | |
e089f05c CM |
27 | static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root |
28 | *root, struct btrfs_path *path, int level); | |
29 | static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root | |
d4dbff95 | 30 | *root, struct btrfs_key *ins_key, |
cc0c5538 | 31 | struct btrfs_path *path, int data_size, int extend); |
5f39d397 CM |
32 | static int push_node_left(struct btrfs_trans_handle *trans, |
33 | struct btrfs_root *root, struct extent_buffer *dst, | |
971a1f66 | 34 | struct extent_buffer *src, int empty); |
5f39d397 CM |
35 | static int balance_node_right(struct btrfs_trans_handle *trans, |
36 | struct btrfs_root *root, | |
37 | struct extent_buffer *dst_buf, | |
38 | struct extent_buffer *src_buf); | |
e089f05c CM |
39 | static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
40 | struct btrfs_path *path, int level, int slot); | |
d97e63b6 | 41 | |
df24a2b9 | 42 | struct btrfs_path *btrfs_alloc_path(void) |
2c90e5d6 | 43 | { |
df24a2b9 | 44 | struct btrfs_path *path; |
e00f7308 | 45 | path = kmem_cache_zalloc(btrfs_path_cachep, GFP_NOFS); |
df24a2b9 | 46 | return path; |
2c90e5d6 CM |
47 | } |
48 | ||
b4ce94de CM |
49 | /* |
50 | * set all locked nodes in the path to blocking locks. This should | |
51 | * be done before scheduling | |
52 | */ | |
53 | noinline void btrfs_set_path_blocking(struct btrfs_path *p) | |
54 | { | |
55 | int i; | |
56 | for (i = 0; i < BTRFS_MAX_LEVEL; i++) { | |
bd681513 CM |
57 | if (!p->nodes[i] || !p->locks[i]) |
58 | continue; | |
59 | btrfs_set_lock_blocking_rw(p->nodes[i], p->locks[i]); | |
60 | if (p->locks[i] == BTRFS_READ_LOCK) | |
61 | p->locks[i] = BTRFS_READ_LOCK_BLOCKING; | |
62 | else if (p->locks[i] == BTRFS_WRITE_LOCK) | |
63 | p->locks[i] = BTRFS_WRITE_LOCK_BLOCKING; | |
b4ce94de CM |
64 | } |
65 | } | |
66 | ||
67 | /* | |
68 | * reset all the locked nodes in the patch to spinning locks. | |
4008c04a CM |
69 | * |
70 | * held is used to keep lockdep happy, when lockdep is enabled | |
71 | * we set held to a blocking lock before we go around and | |
72 | * retake all the spinlocks in the path. You can safely use NULL | |
73 | * for held | |
b4ce94de | 74 | */ |
4008c04a | 75 | noinline void btrfs_clear_path_blocking(struct btrfs_path *p, |
bd681513 | 76 | struct extent_buffer *held, int held_rw) |
b4ce94de CM |
77 | { |
78 | int i; | |
4008c04a CM |
79 | |
80 | #ifdef CONFIG_DEBUG_LOCK_ALLOC | |
81 | /* lockdep really cares that we take all of these spinlocks | |
82 | * in the right order. If any of the locks in the path are not | |
83 | * currently blocking, it is going to complain. So, make really | |
84 | * really sure by forcing the path to blocking before we clear | |
85 | * the path blocking. | |
86 | */ | |
bd681513 CM |
87 | if (held) { |
88 | btrfs_set_lock_blocking_rw(held, held_rw); | |
89 | if (held_rw == BTRFS_WRITE_LOCK) | |
90 | held_rw = BTRFS_WRITE_LOCK_BLOCKING; | |
91 | else if (held_rw == BTRFS_READ_LOCK) | |
92 | held_rw = BTRFS_READ_LOCK_BLOCKING; | |
93 | } | |
4008c04a CM |
94 | btrfs_set_path_blocking(p); |
95 | #endif | |
96 | ||
97 | for (i = BTRFS_MAX_LEVEL - 1; i >= 0; i--) { | |
bd681513 CM |
98 | if (p->nodes[i] && p->locks[i]) { |
99 | btrfs_clear_lock_blocking_rw(p->nodes[i], p->locks[i]); | |
100 | if (p->locks[i] == BTRFS_WRITE_LOCK_BLOCKING) | |
101 | p->locks[i] = BTRFS_WRITE_LOCK; | |
102 | else if (p->locks[i] == BTRFS_READ_LOCK_BLOCKING) | |
103 | p->locks[i] = BTRFS_READ_LOCK; | |
104 | } | |
b4ce94de | 105 | } |
4008c04a CM |
106 | |
107 | #ifdef CONFIG_DEBUG_LOCK_ALLOC | |
108 | if (held) | |
bd681513 | 109 | btrfs_clear_lock_blocking_rw(held, held_rw); |
4008c04a | 110 | #endif |
b4ce94de CM |
111 | } |
112 | ||
d352ac68 | 113 | /* this also releases the path */ |
df24a2b9 | 114 | void btrfs_free_path(struct btrfs_path *p) |
be0e5c09 | 115 | { |
ff175d57 JJ |
116 | if (!p) |
117 | return; | |
b3b4aa74 | 118 | btrfs_release_path(p); |
df24a2b9 | 119 | kmem_cache_free(btrfs_path_cachep, p); |
be0e5c09 CM |
120 | } |
121 | ||
d352ac68 CM |
122 | /* |
123 | * path release drops references on the extent buffers in the path | |
124 | * and it drops any locks held by this path | |
125 | * | |
126 | * It is safe to call this on paths that no locks or extent buffers held. | |
127 | */ | |
b3b4aa74 | 128 | noinline void btrfs_release_path(struct btrfs_path *p) |
eb60ceac CM |
129 | { |
130 | int i; | |
a2135011 | 131 | |
234b63a0 | 132 | for (i = 0; i < BTRFS_MAX_LEVEL; i++) { |
3f157a2f | 133 | p->slots[i] = 0; |
eb60ceac | 134 | if (!p->nodes[i]) |
925baedd CM |
135 | continue; |
136 | if (p->locks[i]) { | |
bd681513 | 137 | btrfs_tree_unlock_rw(p->nodes[i], p->locks[i]); |
925baedd CM |
138 | p->locks[i] = 0; |
139 | } | |
5f39d397 | 140 | free_extent_buffer(p->nodes[i]); |
3f157a2f | 141 | p->nodes[i] = NULL; |
eb60ceac CM |
142 | } |
143 | } | |
144 | ||
d352ac68 CM |
145 | /* |
146 | * safely gets a reference on the root node of a tree. A lock | |
147 | * is not taken, so a concurrent writer may put a different node | |
148 | * at the root of the tree. See btrfs_lock_root_node for the | |
149 | * looping required. | |
150 | * | |
151 | * The extent buffer returned by this has a reference taken, so | |
152 | * it won't disappear. It may stop being the root of the tree | |
153 | * at any time because there are no locks held. | |
154 | */ | |
925baedd CM |
155 | struct extent_buffer *btrfs_root_node(struct btrfs_root *root) |
156 | { | |
157 | struct extent_buffer *eb; | |
240f62c8 | 158 | |
3083ee2e JB |
159 | while (1) { |
160 | rcu_read_lock(); | |
161 | eb = rcu_dereference(root->node); | |
162 | ||
163 | /* | |
164 | * RCU really hurts here, we could free up the root node because | |
165 | * it was cow'ed but we may not get the new root node yet so do | |
166 | * the inc_not_zero dance and if it doesn't work then | |
167 | * synchronize_rcu and try again. | |
168 | */ | |
169 | if (atomic_inc_not_zero(&eb->refs)) { | |
170 | rcu_read_unlock(); | |
171 | break; | |
172 | } | |
173 | rcu_read_unlock(); | |
174 | synchronize_rcu(); | |
175 | } | |
925baedd CM |
176 | return eb; |
177 | } | |
178 | ||
d352ac68 CM |
179 | /* loop around taking references on and locking the root node of the |
180 | * tree until you end up with a lock on the root. A locked buffer | |
181 | * is returned, with a reference held. | |
182 | */ | |
925baedd CM |
183 | struct extent_buffer *btrfs_lock_root_node(struct btrfs_root *root) |
184 | { | |
185 | struct extent_buffer *eb; | |
186 | ||
d397712b | 187 | while (1) { |
925baedd CM |
188 | eb = btrfs_root_node(root); |
189 | btrfs_tree_lock(eb); | |
240f62c8 | 190 | if (eb == root->node) |
925baedd | 191 | break; |
925baedd CM |
192 | btrfs_tree_unlock(eb); |
193 | free_extent_buffer(eb); | |
194 | } | |
195 | return eb; | |
196 | } | |
197 | ||
bd681513 CM |
198 | /* loop around taking references on and locking the root node of the |
199 | * tree until you end up with a lock on the root. A locked buffer | |
200 | * is returned, with a reference held. | |
201 | */ | |
202 | struct extent_buffer *btrfs_read_lock_root_node(struct btrfs_root *root) | |
203 | { | |
204 | struct extent_buffer *eb; | |
205 | ||
206 | while (1) { | |
207 | eb = btrfs_root_node(root); | |
208 | btrfs_tree_read_lock(eb); | |
209 | if (eb == root->node) | |
210 | break; | |
211 | btrfs_tree_read_unlock(eb); | |
212 | free_extent_buffer(eb); | |
213 | } | |
214 | return eb; | |
215 | } | |
216 | ||
d352ac68 CM |
217 | /* cowonly root (everything not a reference counted cow subvolume), just get |
218 | * put onto a simple dirty list. transaction.c walks this to make sure they | |
219 | * get properly updated on disk. | |
220 | */ | |
0b86a832 CM |
221 | static void add_root_to_dirty_list(struct btrfs_root *root) |
222 | { | |
223 | if (root->track_dirty && list_empty(&root->dirty_list)) { | |
224 | list_add(&root->dirty_list, | |
225 | &root->fs_info->dirty_cowonly_roots); | |
226 | } | |
227 | } | |
228 | ||
d352ac68 CM |
229 | /* |
230 | * used by snapshot creation to make a copy of a root for a tree with | |
231 | * a given objectid. The buffer with the new root node is returned in | |
232 | * cow_ret, and this func returns zero on success or a negative error code. | |
233 | */ | |
be20aa9d CM |
234 | int btrfs_copy_root(struct btrfs_trans_handle *trans, |
235 | struct btrfs_root *root, | |
236 | struct extent_buffer *buf, | |
237 | struct extent_buffer **cow_ret, u64 new_root_objectid) | |
238 | { | |
239 | struct extent_buffer *cow; | |
be20aa9d CM |
240 | int ret = 0; |
241 | int level; | |
5d4f98a2 | 242 | struct btrfs_disk_key disk_key; |
be20aa9d CM |
243 | |
244 | WARN_ON(root->ref_cows && trans->transid != | |
245 | root->fs_info->running_transaction->transid); | |
246 | WARN_ON(root->ref_cows && trans->transid != root->last_trans); | |
247 | ||
248 | level = btrfs_header_level(buf); | |
5d4f98a2 YZ |
249 | if (level == 0) |
250 | btrfs_item_key(buf, &disk_key, 0); | |
251 | else | |
252 | btrfs_node_key(buf, &disk_key, 0); | |
31840ae1 | 253 | |
5d4f98a2 YZ |
254 | cow = btrfs_alloc_free_block(trans, root, buf->len, 0, |
255 | new_root_objectid, &disk_key, level, | |
66d7e7f0 | 256 | buf->start, 0, 1); |
5d4f98a2 | 257 | if (IS_ERR(cow)) |
be20aa9d CM |
258 | return PTR_ERR(cow); |
259 | ||
260 | copy_extent_buffer(cow, buf, 0, 0, cow->len); | |
261 | btrfs_set_header_bytenr(cow, cow->start); | |
262 | btrfs_set_header_generation(cow, trans->transid); | |
5d4f98a2 YZ |
263 | btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV); |
264 | btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN | | |
265 | BTRFS_HEADER_FLAG_RELOC); | |
266 | if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID) | |
267 | btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC); | |
268 | else | |
269 | btrfs_set_header_owner(cow, new_root_objectid); | |
be20aa9d | 270 | |
2b82032c YZ |
271 | write_extent_buffer(cow, root->fs_info->fsid, |
272 | (unsigned long)btrfs_header_fsid(cow), | |
273 | BTRFS_FSID_SIZE); | |
274 | ||
be20aa9d | 275 | WARN_ON(btrfs_header_generation(buf) > trans->transid); |
5d4f98a2 | 276 | if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID) |
66d7e7f0 | 277 | ret = btrfs_inc_ref(trans, root, cow, 1, 1); |
5d4f98a2 | 278 | else |
66d7e7f0 | 279 | ret = btrfs_inc_ref(trans, root, cow, 0, 1); |
4aec2b52 | 280 | |
be20aa9d CM |
281 | if (ret) |
282 | return ret; | |
283 | ||
284 | btrfs_mark_buffer_dirty(cow); | |
285 | *cow_ret = cow; | |
286 | return 0; | |
287 | } | |
288 | ||
5d4f98a2 YZ |
289 | /* |
290 | * check if the tree block can be shared by multiple trees | |
291 | */ | |
292 | int btrfs_block_can_be_shared(struct btrfs_root *root, | |
293 | struct extent_buffer *buf) | |
294 | { | |
295 | /* | |
296 | * Tree blocks not in refernece counted trees and tree roots | |
297 | * are never shared. If a block was allocated after the last | |
298 | * snapshot and the block was not allocated by tree relocation, | |
299 | * we know the block is not shared. | |
300 | */ | |
301 | if (root->ref_cows && | |
302 | buf != root->node && buf != root->commit_root && | |
303 | (btrfs_header_generation(buf) <= | |
304 | btrfs_root_last_snapshot(&root->root_item) || | |
305 | btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC))) | |
306 | return 1; | |
307 | #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 | |
308 | if (root->ref_cows && | |
309 | btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) | |
310 | return 1; | |
311 | #endif | |
312 | return 0; | |
313 | } | |
314 | ||
315 | static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans, | |
316 | struct btrfs_root *root, | |
317 | struct extent_buffer *buf, | |
f0486c68 YZ |
318 | struct extent_buffer *cow, |
319 | int *last_ref) | |
5d4f98a2 YZ |
320 | { |
321 | u64 refs; | |
322 | u64 owner; | |
323 | u64 flags; | |
324 | u64 new_flags = 0; | |
325 | int ret; | |
326 | ||
327 | /* | |
328 | * Backrefs update rules: | |
329 | * | |
330 | * Always use full backrefs for extent pointers in tree block | |
331 | * allocated by tree relocation. | |
332 | * | |
333 | * If a shared tree block is no longer referenced by its owner | |
334 | * tree (btrfs_header_owner(buf) == root->root_key.objectid), | |
335 | * use full backrefs for extent pointers in tree block. | |
336 | * | |
337 | * If a tree block is been relocating | |
338 | * (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID), | |
339 | * use full backrefs for extent pointers in tree block. | |
340 | * The reason for this is some operations (such as drop tree) | |
341 | * are only allowed for blocks use full backrefs. | |
342 | */ | |
343 | ||
344 | if (btrfs_block_can_be_shared(root, buf)) { | |
345 | ret = btrfs_lookup_extent_info(trans, root, buf->start, | |
346 | buf->len, &refs, &flags); | |
347 | BUG_ON(ret); | |
348 | BUG_ON(refs == 0); | |
349 | } else { | |
350 | refs = 1; | |
351 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID || | |
352 | btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) | |
353 | flags = BTRFS_BLOCK_FLAG_FULL_BACKREF; | |
354 | else | |
355 | flags = 0; | |
356 | } | |
357 | ||
358 | owner = btrfs_header_owner(buf); | |
359 | BUG_ON(owner == BTRFS_TREE_RELOC_OBJECTID && | |
360 | !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)); | |
361 | ||
362 | if (refs > 1) { | |
363 | if ((owner == root->root_key.objectid || | |
364 | root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) && | |
365 | !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)) { | |
66d7e7f0 | 366 | ret = btrfs_inc_ref(trans, root, buf, 1, 1); |
5d4f98a2 YZ |
367 | BUG_ON(ret); |
368 | ||
369 | if (root->root_key.objectid == | |
370 | BTRFS_TREE_RELOC_OBJECTID) { | |
66d7e7f0 | 371 | ret = btrfs_dec_ref(trans, root, buf, 0, 1); |
5d4f98a2 | 372 | BUG_ON(ret); |
66d7e7f0 | 373 | ret = btrfs_inc_ref(trans, root, cow, 1, 1); |
5d4f98a2 YZ |
374 | BUG_ON(ret); |
375 | } | |
376 | new_flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF; | |
377 | } else { | |
378 | ||
379 | if (root->root_key.objectid == | |
380 | BTRFS_TREE_RELOC_OBJECTID) | |
66d7e7f0 | 381 | ret = btrfs_inc_ref(trans, root, cow, 1, 1); |
5d4f98a2 | 382 | else |
66d7e7f0 | 383 | ret = btrfs_inc_ref(trans, root, cow, 0, 1); |
5d4f98a2 YZ |
384 | BUG_ON(ret); |
385 | } | |
386 | if (new_flags != 0) { | |
387 | ret = btrfs_set_disk_extent_flags(trans, root, | |
388 | buf->start, | |
389 | buf->len, | |
390 | new_flags, 0); | |
391 | BUG_ON(ret); | |
392 | } | |
393 | } else { | |
394 | if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF) { | |
395 | if (root->root_key.objectid == | |
396 | BTRFS_TREE_RELOC_OBJECTID) | |
66d7e7f0 | 397 | ret = btrfs_inc_ref(trans, root, cow, 1, 1); |
5d4f98a2 | 398 | else |
66d7e7f0 | 399 | ret = btrfs_inc_ref(trans, root, cow, 0, 1); |
5d4f98a2 | 400 | BUG_ON(ret); |
66d7e7f0 | 401 | ret = btrfs_dec_ref(trans, root, buf, 1, 1); |
5d4f98a2 YZ |
402 | BUG_ON(ret); |
403 | } | |
404 | clean_tree_block(trans, root, buf); | |
f0486c68 | 405 | *last_ref = 1; |
5d4f98a2 YZ |
406 | } |
407 | return 0; | |
408 | } | |
409 | ||
d352ac68 | 410 | /* |
d397712b CM |
411 | * does the dirty work in cow of a single block. The parent block (if |
412 | * supplied) is updated to point to the new cow copy. The new buffer is marked | |
413 | * dirty and returned locked. If you modify the block it needs to be marked | |
414 | * dirty again. | |
d352ac68 CM |
415 | * |
416 | * search_start -- an allocation hint for the new block | |
417 | * | |
d397712b CM |
418 | * empty_size -- a hint that you plan on doing more cow. This is the size in |
419 | * bytes the allocator should try to find free next to the block it returns. | |
420 | * This is just a hint and may be ignored by the allocator. | |
d352ac68 | 421 | */ |
d397712b | 422 | static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans, |
5f39d397 CM |
423 | struct btrfs_root *root, |
424 | struct extent_buffer *buf, | |
425 | struct extent_buffer *parent, int parent_slot, | |
426 | struct extent_buffer **cow_ret, | |
9fa8cfe7 | 427 | u64 search_start, u64 empty_size) |
02217ed2 | 428 | { |
5d4f98a2 | 429 | struct btrfs_disk_key disk_key; |
5f39d397 | 430 | struct extent_buffer *cow; |
7bb86316 | 431 | int level; |
f0486c68 | 432 | int last_ref = 0; |
925baedd | 433 | int unlock_orig = 0; |
5d4f98a2 | 434 | u64 parent_start; |
7bb86316 | 435 | |
925baedd CM |
436 | if (*cow_ret == buf) |
437 | unlock_orig = 1; | |
438 | ||
b9447ef8 | 439 | btrfs_assert_tree_locked(buf); |
925baedd | 440 | |
7bb86316 CM |
441 | WARN_ON(root->ref_cows && trans->transid != |
442 | root->fs_info->running_transaction->transid); | |
6702ed49 | 443 | WARN_ON(root->ref_cows && trans->transid != root->last_trans); |
5f39d397 | 444 | |
7bb86316 | 445 | level = btrfs_header_level(buf); |
31840ae1 | 446 | |
5d4f98a2 YZ |
447 | if (level == 0) |
448 | btrfs_item_key(buf, &disk_key, 0); | |
449 | else | |
450 | btrfs_node_key(buf, &disk_key, 0); | |
451 | ||
452 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) { | |
453 | if (parent) | |
454 | parent_start = parent->start; | |
455 | else | |
456 | parent_start = 0; | |
457 | } else | |
458 | parent_start = 0; | |
459 | ||
460 | cow = btrfs_alloc_free_block(trans, root, buf->len, parent_start, | |
461 | root->root_key.objectid, &disk_key, | |
66d7e7f0 | 462 | level, search_start, empty_size, 1); |
54aa1f4d CM |
463 | if (IS_ERR(cow)) |
464 | return PTR_ERR(cow); | |
6702ed49 | 465 | |
b4ce94de CM |
466 | /* cow is set to blocking by btrfs_init_new_buffer */ |
467 | ||
5f39d397 | 468 | copy_extent_buffer(cow, buf, 0, 0, cow->len); |
db94535d | 469 | btrfs_set_header_bytenr(cow, cow->start); |
5f39d397 | 470 | btrfs_set_header_generation(cow, trans->transid); |
5d4f98a2 YZ |
471 | btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV); |
472 | btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN | | |
473 | BTRFS_HEADER_FLAG_RELOC); | |
474 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) | |
475 | btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC); | |
476 | else | |
477 | btrfs_set_header_owner(cow, root->root_key.objectid); | |
6702ed49 | 478 | |
2b82032c YZ |
479 | write_extent_buffer(cow, root->fs_info->fsid, |
480 | (unsigned long)btrfs_header_fsid(cow), | |
481 | BTRFS_FSID_SIZE); | |
482 | ||
f0486c68 | 483 | update_ref_for_cow(trans, root, buf, cow, &last_ref); |
1a40e23b | 484 | |
3fd0a558 YZ |
485 | if (root->ref_cows) |
486 | btrfs_reloc_cow_block(trans, root, buf, cow); | |
487 | ||
02217ed2 | 488 | if (buf == root->node) { |
925baedd | 489 | WARN_ON(parent && parent != buf); |
5d4f98a2 YZ |
490 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID || |
491 | btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) | |
492 | parent_start = buf->start; | |
493 | else | |
494 | parent_start = 0; | |
925baedd | 495 | |
5f39d397 | 496 | extent_buffer_get(cow); |
240f62c8 | 497 | rcu_assign_pointer(root->node, cow); |
925baedd | 498 | |
f0486c68 | 499 | btrfs_free_tree_block(trans, root, buf, parent_start, |
66d7e7f0 | 500 | last_ref, 1); |
5f39d397 | 501 | free_extent_buffer(buf); |
0b86a832 | 502 | add_root_to_dirty_list(root); |
02217ed2 | 503 | } else { |
5d4f98a2 YZ |
504 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) |
505 | parent_start = parent->start; | |
506 | else | |
507 | parent_start = 0; | |
508 | ||
509 | WARN_ON(trans->transid != btrfs_header_generation(parent)); | |
5f39d397 | 510 | btrfs_set_node_blockptr(parent, parent_slot, |
db94535d | 511 | cow->start); |
74493f7a CM |
512 | btrfs_set_node_ptr_generation(parent, parent_slot, |
513 | trans->transid); | |
d6025579 | 514 | btrfs_mark_buffer_dirty(parent); |
f0486c68 | 515 | btrfs_free_tree_block(trans, root, buf, parent_start, |
66d7e7f0 | 516 | last_ref, 1); |
02217ed2 | 517 | } |
925baedd CM |
518 | if (unlock_orig) |
519 | btrfs_tree_unlock(buf); | |
3083ee2e | 520 | free_extent_buffer_stale(buf); |
ccd467d6 | 521 | btrfs_mark_buffer_dirty(cow); |
2c90e5d6 | 522 | *cow_ret = cow; |
02217ed2 CM |
523 | return 0; |
524 | } | |
525 | ||
5d4f98a2 YZ |
526 | static inline int should_cow_block(struct btrfs_trans_handle *trans, |
527 | struct btrfs_root *root, | |
528 | struct extent_buffer *buf) | |
529 | { | |
f1ebcc74 LB |
530 | /* ensure we can see the force_cow */ |
531 | smp_rmb(); | |
532 | ||
533 | /* | |
534 | * We do not need to cow a block if | |
535 | * 1) this block is not created or changed in this transaction; | |
536 | * 2) this block does not belong to TREE_RELOC tree; | |
537 | * 3) the root is not forced COW. | |
538 | * | |
539 | * What is forced COW: | |
540 | * when we create snapshot during commiting the transaction, | |
541 | * after we've finished coping src root, we must COW the shared | |
542 | * block to ensure the metadata consistency. | |
543 | */ | |
5d4f98a2 YZ |
544 | if (btrfs_header_generation(buf) == trans->transid && |
545 | !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN) && | |
546 | !(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID && | |
f1ebcc74 LB |
547 | btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC)) && |
548 | !root->force_cow) | |
5d4f98a2 YZ |
549 | return 0; |
550 | return 1; | |
551 | } | |
552 | ||
d352ac68 CM |
553 | /* |
554 | * cows a single block, see __btrfs_cow_block for the real work. | |
555 | * This version of it has extra checks so that a block isn't cow'd more than | |
556 | * once per transaction, as long as it hasn't been written yet | |
557 | */ | |
d397712b | 558 | noinline int btrfs_cow_block(struct btrfs_trans_handle *trans, |
5f39d397 CM |
559 | struct btrfs_root *root, struct extent_buffer *buf, |
560 | struct extent_buffer *parent, int parent_slot, | |
9fa8cfe7 | 561 | struct extent_buffer **cow_ret) |
6702ed49 CM |
562 | { |
563 | u64 search_start; | |
f510cfec | 564 | int ret; |
dc17ff8f | 565 | |
6702ed49 | 566 | if (trans->transaction != root->fs_info->running_transaction) { |
d397712b CM |
567 | printk(KERN_CRIT "trans %llu running %llu\n", |
568 | (unsigned long long)trans->transid, | |
569 | (unsigned long long) | |
6702ed49 CM |
570 | root->fs_info->running_transaction->transid); |
571 | WARN_ON(1); | |
572 | } | |
573 | if (trans->transid != root->fs_info->generation) { | |
d397712b CM |
574 | printk(KERN_CRIT "trans %llu running %llu\n", |
575 | (unsigned long long)trans->transid, | |
576 | (unsigned long long)root->fs_info->generation); | |
6702ed49 CM |
577 | WARN_ON(1); |
578 | } | |
dc17ff8f | 579 | |
5d4f98a2 | 580 | if (!should_cow_block(trans, root, buf)) { |
6702ed49 CM |
581 | *cow_ret = buf; |
582 | return 0; | |
583 | } | |
c487685d | 584 | |
0b86a832 | 585 | search_start = buf->start & ~((u64)(1024 * 1024 * 1024) - 1); |
b4ce94de CM |
586 | |
587 | if (parent) | |
588 | btrfs_set_lock_blocking(parent); | |
589 | btrfs_set_lock_blocking(buf); | |
590 | ||
f510cfec | 591 | ret = __btrfs_cow_block(trans, root, buf, parent, |
9fa8cfe7 | 592 | parent_slot, cow_ret, search_start, 0); |
1abe9b8a | 593 | |
594 | trace_btrfs_cow_block(root, buf, *cow_ret); | |
595 | ||
f510cfec | 596 | return ret; |
6702ed49 CM |
597 | } |
598 | ||
d352ac68 CM |
599 | /* |
600 | * helper function for defrag to decide if two blocks pointed to by a | |
601 | * node are actually close by | |
602 | */ | |
6b80053d | 603 | static int close_blocks(u64 blocknr, u64 other, u32 blocksize) |
6702ed49 | 604 | { |
6b80053d | 605 | if (blocknr < other && other - (blocknr + blocksize) < 32768) |
6702ed49 | 606 | return 1; |
6b80053d | 607 | if (blocknr > other && blocknr - (other + blocksize) < 32768) |
6702ed49 CM |
608 | return 1; |
609 | return 0; | |
610 | } | |
611 | ||
081e9573 CM |
612 | /* |
613 | * compare two keys in a memcmp fashion | |
614 | */ | |
615 | static int comp_keys(struct btrfs_disk_key *disk, struct btrfs_key *k2) | |
616 | { | |
617 | struct btrfs_key k1; | |
618 | ||
619 | btrfs_disk_key_to_cpu(&k1, disk); | |
620 | ||
20736aba | 621 | return btrfs_comp_cpu_keys(&k1, k2); |
081e9573 CM |
622 | } |
623 | ||
f3465ca4 JB |
624 | /* |
625 | * same as comp_keys only with two btrfs_key's | |
626 | */ | |
5d4f98a2 | 627 | int btrfs_comp_cpu_keys(struct btrfs_key *k1, struct btrfs_key *k2) |
f3465ca4 JB |
628 | { |
629 | if (k1->objectid > k2->objectid) | |
630 | return 1; | |
631 | if (k1->objectid < k2->objectid) | |
632 | return -1; | |
633 | if (k1->type > k2->type) | |
634 | return 1; | |
635 | if (k1->type < k2->type) | |
636 | return -1; | |
637 | if (k1->offset > k2->offset) | |
638 | return 1; | |
639 | if (k1->offset < k2->offset) | |
640 | return -1; | |
641 | return 0; | |
642 | } | |
081e9573 | 643 | |
d352ac68 CM |
644 | /* |
645 | * this is used by the defrag code to go through all the | |
646 | * leaves pointed to by a node and reallocate them so that | |
647 | * disk order is close to key order | |
648 | */ | |
6702ed49 | 649 | int btrfs_realloc_node(struct btrfs_trans_handle *trans, |
5f39d397 | 650 | struct btrfs_root *root, struct extent_buffer *parent, |
a6b6e75e CM |
651 | int start_slot, int cache_only, u64 *last_ret, |
652 | struct btrfs_key *progress) | |
6702ed49 | 653 | { |
6b80053d | 654 | struct extent_buffer *cur; |
6702ed49 | 655 | u64 blocknr; |
ca7a79ad | 656 | u64 gen; |
e9d0b13b CM |
657 | u64 search_start = *last_ret; |
658 | u64 last_block = 0; | |
6702ed49 CM |
659 | u64 other; |
660 | u32 parent_nritems; | |
6702ed49 CM |
661 | int end_slot; |
662 | int i; | |
663 | int err = 0; | |
f2183bde | 664 | int parent_level; |
6b80053d CM |
665 | int uptodate; |
666 | u32 blocksize; | |
081e9573 CM |
667 | int progress_passed = 0; |
668 | struct btrfs_disk_key disk_key; | |
6702ed49 | 669 | |
5708b959 CM |
670 | parent_level = btrfs_header_level(parent); |
671 | if (cache_only && parent_level != 1) | |
672 | return 0; | |
673 | ||
d397712b | 674 | if (trans->transaction != root->fs_info->running_transaction) |
6702ed49 | 675 | WARN_ON(1); |
d397712b | 676 | if (trans->transid != root->fs_info->generation) |
6702ed49 | 677 | WARN_ON(1); |
86479a04 | 678 | |
6b80053d | 679 | parent_nritems = btrfs_header_nritems(parent); |
6b80053d | 680 | blocksize = btrfs_level_size(root, parent_level - 1); |
6702ed49 CM |
681 | end_slot = parent_nritems; |
682 | ||
683 | if (parent_nritems == 1) | |
684 | return 0; | |
685 | ||
b4ce94de CM |
686 | btrfs_set_lock_blocking(parent); |
687 | ||
6702ed49 CM |
688 | for (i = start_slot; i < end_slot; i++) { |
689 | int close = 1; | |
a6b6e75e | 690 | |
081e9573 CM |
691 | btrfs_node_key(parent, &disk_key, i); |
692 | if (!progress_passed && comp_keys(&disk_key, progress) < 0) | |
693 | continue; | |
694 | ||
695 | progress_passed = 1; | |
6b80053d | 696 | blocknr = btrfs_node_blockptr(parent, i); |
ca7a79ad | 697 | gen = btrfs_node_ptr_generation(parent, i); |
e9d0b13b CM |
698 | if (last_block == 0) |
699 | last_block = blocknr; | |
5708b959 | 700 | |
6702ed49 | 701 | if (i > 0) { |
6b80053d CM |
702 | other = btrfs_node_blockptr(parent, i - 1); |
703 | close = close_blocks(blocknr, other, blocksize); | |
6702ed49 | 704 | } |
0ef3e66b | 705 | if (!close && i < end_slot - 2) { |
6b80053d CM |
706 | other = btrfs_node_blockptr(parent, i + 1); |
707 | close = close_blocks(blocknr, other, blocksize); | |
6702ed49 | 708 | } |
e9d0b13b CM |
709 | if (close) { |
710 | last_block = blocknr; | |
6702ed49 | 711 | continue; |
e9d0b13b | 712 | } |
6702ed49 | 713 | |
6b80053d CM |
714 | cur = btrfs_find_tree_block(root, blocknr, blocksize); |
715 | if (cur) | |
1259ab75 | 716 | uptodate = btrfs_buffer_uptodate(cur, gen); |
6b80053d CM |
717 | else |
718 | uptodate = 0; | |
5708b959 | 719 | if (!cur || !uptodate) { |
6702ed49 | 720 | if (cache_only) { |
6b80053d | 721 | free_extent_buffer(cur); |
6702ed49 CM |
722 | continue; |
723 | } | |
6b80053d CM |
724 | if (!cur) { |
725 | cur = read_tree_block(root, blocknr, | |
ca7a79ad | 726 | blocksize, gen); |
97d9a8a4 TI |
727 | if (!cur) |
728 | return -EIO; | |
6b80053d | 729 | } else if (!uptodate) { |
ca7a79ad | 730 | btrfs_read_buffer(cur, gen); |
f2183bde | 731 | } |
6702ed49 | 732 | } |
e9d0b13b | 733 | if (search_start == 0) |
6b80053d | 734 | search_start = last_block; |
e9d0b13b | 735 | |
e7a84565 | 736 | btrfs_tree_lock(cur); |
b4ce94de | 737 | btrfs_set_lock_blocking(cur); |
6b80053d | 738 | err = __btrfs_cow_block(trans, root, cur, parent, i, |
e7a84565 | 739 | &cur, search_start, |
6b80053d | 740 | min(16 * blocksize, |
9fa8cfe7 | 741 | (end_slot - i) * blocksize)); |
252c38f0 | 742 | if (err) { |
e7a84565 | 743 | btrfs_tree_unlock(cur); |
6b80053d | 744 | free_extent_buffer(cur); |
6702ed49 | 745 | break; |
252c38f0 | 746 | } |
e7a84565 CM |
747 | search_start = cur->start; |
748 | last_block = cur->start; | |
f2183bde | 749 | *last_ret = search_start; |
e7a84565 CM |
750 | btrfs_tree_unlock(cur); |
751 | free_extent_buffer(cur); | |
6702ed49 CM |
752 | } |
753 | return err; | |
754 | } | |
755 | ||
74123bd7 CM |
756 | /* |
757 | * The leaf data grows from end-to-front in the node. | |
758 | * this returns the address of the start of the last item, | |
759 | * which is the stop of the leaf data stack | |
760 | */ | |
123abc88 | 761 | static inline unsigned int leaf_data_end(struct btrfs_root *root, |
5f39d397 | 762 | struct extent_buffer *leaf) |
be0e5c09 | 763 | { |
5f39d397 | 764 | u32 nr = btrfs_header_nritems(leaf); |
be0e5c09 | 765 | if (nr == 0) |
123abc88 | 766 | return BTRFS_LEAF_DATA_SIZE(root); |
5f39d397 | 767 | return btrfs_item_offset_nr(leaf, nr - 1); |
be0e5c09 CM |
768 | } |
769 | ||
aa5d6bed | 770 | |
74123bd7 | 771 | /* |
5f39d397 CM |
772 | * search for key in the extent_buffer. The items start at offset p, |
773 | * and they are item_size apart. There are 'max' items in p. | |
774 | * | |
74123bd7 CM |
775 | * the slot in the array is returned via slot, and it points to |
776 | * the place where you would insert key if it is not found in | |
777 | * the array. | |
778 | * | |
779 | * slot may point to max if the key is bigger than all of the keys | |
780 | */ | |
e02119d5 CM |
781 | static noinline int generic_bin_search(struct extent_buffer *eb, |
782 | unsigned long p, | |
783 | int item_size, struct btrfs_key *key, | |
784 | int max, int *slot) | |
be0e5c09 CM |
785 | { |
786 | int low = 0; | |
787 | int high = max; | |
788 | int mid; | |
789 | int ret; | |
479965d6 | 790 | struct btrfs_disk_key *tmp = NULL; |
5f39d397 CM |
791 | struct btrfs_disk_key unaligned; |
792 | unsigned long offset; | |
5f39d397 CM |
793 | char *kaddr = NULL; |
794 | unsigned long map_start = 0; | |
795 | unsigned long map_len = 0; | |
479965d6 | 796 | int err; |
be0e5c09 | 797 | |
d397712b | 798 | while (low < high) { |
be0e5c09 | 799 | mid = (low + high) / 2; |
5f39d397 CM |
800 | offset = p + mid * item_size; |
801 | ||
a6591715 | 802 | if (!kaddr || offset < map_start || |
5f39d397 CM |
803 | (offset + sizeof(struct btrfs_disk_key)) > |
804 | map_start + map_len) { | |
934d375b CM |
805 | |
806 | err = map_private_extent_buffer(eb, offset, | |
479965d6 | 807 | sizeof(struct btrfs_disk_key), |
a6591715 | 808 | &kaddr, &map_start, &map_len); |
479965d6 CM |
809 | |
810 | if (!err) { | |
811 | tmp = (struct btrfs_disk_key *)(kaddr + offset - | |
812 | map_start); | |
813 | } else { | |
814 | read_extent_buffer(eb, &unaligned, | |
815 | offset, sizeof(unaligned)); | |
816 | tmp = &unaligned; | |
817 | } | |
5f39d397 | 818 | |
5f39d397 CM |
819 | } else { |
820 | tmp = (struct btrfs_disk_key *)(kaddr + offset - | |
821 | map_start); | |
822 | } | |
be0e5c09 CM |
823 | ret = comp_keys(tmp, key); |
824 | ||
825 | if (ret < 0) | |
826 | low = mid + 1; | |
827 | else if (ret > 0) | |
828 | high = mid; | |
829 | else { | |
830 | *slot = mid; | |
831 | return 0; | |
832 | } | |
833 | } | |
834 | *slot = low; | |
835 | return 1; | |
836 | } | |
837 | ||
97571fd0 CM |
838 | /* |
839 | * simple bin_search frontend that does the right thing for | |
840 | * leaves vs nodes | |
841 | */ | |
5f39d397 CM |
842 | static int bin_search(struct extent_buffer *eb, struct btrfs_key *key, |
843 | int level, int *slot) | |
be0e5c09 | 844 | { |
5f39d397 CM |
845 | if (level == 0) { |
846 | return generic_bin_search(eb, | |
847 | offsetof(struct btrfs_leaf, items), | |
0783fcfc | 848 | sizeof(struct btrfs_item), |
5f39d397 | 849 | key, btrfs_header_nritems(eb), |
7518a238 | 850 | slot); |
be0e5c09 | 851 | } else { |
5f39d397 CM |
852 | return generic_bin_search(eb, |
853 | offsetof(struct btrfs_node, ptrs), | |
123abc88 | 854 | sizeof(struct btrfs_key_ptr), |
5f39d397 | 855 | key, btrfs_header_nritems(eb), |
7518a238 | 856 | slot); |
be0e5c09 CM |
857 | } |
858 | return -1; | |
859 | } | |
860 | ||
5d4f98a2 YZ |
861 | int btrfs_bin_search(struct extent_buffer *eb, struct btrfs_key *key, |
862 | int level, int *slot) | |
863 | { | |
864 | return bin_search(eb, key, level, slot); | |
865 | } | |
866 | ||
f0486c68 YZ |
867 | static void root_add_used(struct btrfs_root *root, u32 size) |
868 | { | |
869 | spin_lock(&root->accounting_lock); | |
870 | btrfs_set_root_used(&root->root_item, | |
871 | btrfs_root_used(&root->root_item) + size); | |
872 | spin_unlock(&root->accounting_lock); | |
873 | } | |
874 | ||
875 | static void root_sub_used(struct btrfs_root *root, u32 size) | |
876 | { | |
877 | spin_lock(&root->accounting_lock); | |
878 | btrfs_set_root_used(&root->root_item, | |
879 | btrfs_root_used(&root->root_item) - size); | |
880 | spin_unlock(&root->accounting_lock); | |
881 | } | |
882 | ||
d352ac68 CM |
883 | /* given a node and slot number, this reads the blocks it points to. The |
884 | * extent buffer is returned with a reference taken (but unlocked). | |
885 | * NULL is returned on error. | |
886 | */ | |
e02119d5 | 887 | static noinline struct extent_buffer *read_node_slot(struct btrfs_root *root, |
5f39d397 | 888 | struct extent_buffer *parent, int slot) |
bb803951 | 889 | { |
ca7a79ad | 890 | int level = btrfs_header_level(parent); |
bb803951 CM |
891 | if (slot < 0) |
892 | return NULL; | |
5f39d397 | 893 | if (slot >= btrfs_header_nritems(parent)) |
bb803951 | 894 | return NULL; |
ca7a79ad CM |
895 | |
896 | BUG_ON(level == 0); | |
897 | ||
db94535d | 898 | return read_tree_block(root, btrfs_node_blockptr(parent, slot), |
ca7a79ad CM |
899 | btrfs_level_size(root, level - 1), |
900 | btrfs_node_ptr_generation(parent, slot)); | |
bb803951 CM |
901 | } |
902 | ||
d352ac68 CM |
903 | /* |
904 | * node level balancing, used to make sure nodes are in proper order for | |
905 | * item deletion. We balance from the top down, so we have to make sure | |
906 | * that a deletion won't leave an node completely empty later on. | |
907 | */ | |
e02119d5 | 908 | static noinline int balance_level(struct btrfs_trans_handle *trans, |
98ed5174 CM |
909 | struct btrfs_root *root, |
910 | struct btrfs_path *path, int level) | |
bb803951 | 911 | { |
5f39d397 CM |
912 | struct extent_buffer *right = NULL; |
913 | struct extent_buffer *mid; | |
914 | struct extent_buffer *left = NULL; | |
915 | struct extent_buffer *parent = NULL; | |
bb803951 CM |
916 | int ret = 0; |
917 | int wret; | |
918 | int pslot; | |
bb803951 | 919 | int orig_slot = path->slots[level]; |
79f95c82 | 920 | u64 orig_ptr; |
bb803951 CM |
921 | |
922 | if (level == 0) | |
923 | return 0; | |
924 | ||
5f39d397 | 925 | mid = path->nodes[level]; |
b4ce94de | 926 | |
bd681513 CM |
927 | WARN_ON(path->locks[level] != BTRFS_WRITE_LOCK && |
928 | path->locks[level] != BTRFS_WRITE_LOCK_BLOCKING); | |
7bb86316 CM |
929 | WARN_ON(btrfs_header_generation(mid) != trans->transid); |
930 | ||
1d4f8a0c | 931 | orig_ptr = btrfs_node_blockptr(mid, orig_slot); |
79f95c82 | 932 | |
a05a9bb1 | 933 | if (level < BTRFS_MAX_LEVEL - 1) { |
5f39d397 | 934 | parent = path->nodes[level + 1]; |
a05a9bb1 LZ |
935 | pslot = path->slots[level + 1]; |
936 | } | |
bb803951 | 937 | |
40689478 CM |
938 | /* |
939 | * deal with the case where there is only one pointer in the root | |
940 | * by promoting the node below to a root | |
941 | */ | |
5f39d397 CM |
942 | if (!parent) { |
943 | struct extent_buffer *child; | |
bb803951 | 944 | |
5f39d397 | 945 | if (btrfs_header_nritems(mid) != 1) |
bb803951 CM |
946 | return 0; |
947 | ||
948 | /* promote the child to a root */ | |
5f39d397 | 949 | child = read_node_slot(root, mid, 0); |
7951f3ce | 950 | BUG_ON(!child); |
925baedd | 951 | btrfs_tree_lock(child); |
b4ce94de | 952 | btrfs_set_lock_blocking(child); |
9fa8cfe7 | 953 | ret = btrfs_cow_block(trans, root, child, mid, 0, &child); |
f0486c68 YZ |
954 | if (ret) { |
955 | btrfs_tree_unlock(child); | |
956 | free_extent_buffer(child); | |
957 | goto enospc; | |
958 | } | |
2f375ab9 | 959 | |
240f62c8 | 960 | rcu_assign_pointer(root->node, child); |
925baedd | 961 | |
0b86a832 | 962 | add_root_to_dirty_list(root); |
925baedd | 963 | btrfs_tree_unlock(child); |
b4ce94de | 964 | |
925baedd | 965 | path->locks[level] = 0; |
bb803951 | 966 | path->nodes[level] = NULL; |
5f39d397 | 967 | clean_tree_block(trans, root, mid); |
925baedd | 968 | btrfs_tree_unlock(mid); |
bb803951 | 969 | /* once for the path */ |
5f39d397 | 970 | free_extent_buffer(mid); |
f0486c68 YZ |
971 | |
972 | root_sub_used(root, mid->len); | |
66d7e7f0 | 973 | btrfs_free_tree_block(trans, root, mid, 0, 1, 0); |
bb803951 | 974 | /* once for the root ptr */ |
3083ee2e | 975 | free_extent_buffer_stale(mid); |
f0486c68 | 976 | return 0; |
bb803951 | 977 | } |
5f39d397 | 978 | if (btrfs_header_nritems(mid) > |
123abc88 | 979 | BTRFS_NODEPTRS_PER_BLOCK(root) / 4) |
bb803951 CM |
980 | return 0; |
981 | ||
559af821 | 982 | btrfs_header_nritems(mid); |
54aa1f4d | 983 | |
5f39d397 CM |
984 | left = read_node_slot(root, parent, pslot - 1); |
985 | if (left) { | |
925baedd | 986 | btrfs_tree_lock(left); |
b4ce94de | 987 | btrfs_set_lock_blocking(left); |
5f39d397 | 988 | wret = btrfs_cow_block(trans, root, left, |
9fa8cfe7 | 989 | parent, pslot - 1, &left); |
54aa1f4d CM |
990 | if (wret) { |
991 | ret = wret; | |
992 | goto enospc; | |
993 | } | |
2cc58cf2 | 994 | } |
5f39d397 CM |
995 | right = read_node_slot(root, parent, pslot + 1); |
996 | if (right) { | |
925baedd | 997 | btrfs_tree_lock(right); |
b4ce94de | 998 | btrfs_set_lock_blocking(right); |
5f39d397 | 999 | wret = btrfs_cow_block(trans, root, right, |
9fa8cfe7 | 1000 | parent, pslot + 1, &right); |
2cc58cf2 CM |
1001 | if (wret) { |
1002 | ret = wret; | |
1003 | goto enospc; | |
1004 | } | |
1005 | } | |
1006 | ||
1007 | /* first, try to make some room in the middle buffer */ | |
5f39d397 CM |
1008 | if (left) { |
1009 | orig_slot += btrfs_header_nritems(left); | |
bce4eae9 | 1010 | wret = push_node_left(trans, root, left, mid, 1); |
79f95c82 CM |
1011 | if (wret < 0) |
1012 | ret = wret; | |
559af821 | 1013 | btrfs_header_nritems(mid); |
bb803951 | 1014 | } |
79f95c82 CM |
1015 | |
1016 | /* | |
1017 | * then try to empty the right most buffer into the middle | |
1018 | */ | |
5f39d397 | 1019 | if (right) { |
971a1f66 | 1020 | wret = push_node_left(trans, root, mid, right, 1); |
54aa1f4d | 1021 | if (wret < 0 && wret != -ENOSPC) |
79f95c82 | 1022 | ret = wret; |
5f39d397 | 1023 | if (btrfs_header_nritems(right) == 0) { |
5f39d397 | 1024 | clean_tree_block(trans, root, right); |
925baedd | 1025 | btrfs_tree_unlock(right); |
e089f05c CM |
1026 | wret = del_ptr(trans, root, path, level + 1, pslot + |
1027 | 1); | |
bb803951 CM |
1028 | if (wret) |
1029 | ret = wret; | |
f0486c68 | 1030 | root_sub_used(root, right->len); |
66d7e7f0 | 1031 | btrfs_free_tree_block(trans, root, right, 0, 1, 0); |
3083ee2e | 1032 | free_extent_buffer_stale(right); |
f0486c68 | 1033 | right = NULL; |
bb803951 | 1034 | } else { |
5f39d397 CM |
1035 | struct btrfs_disk_key right_key; |
1036 | btrfs_node_key(right, &right_key, 0); | |
1037 | btrfs_set_node_key(parent, &right_key, pslot + 1); | |
1038 | btrfs_mark_buffer_dirty(parent); | |
bb803951 CM |
1039 | } |
1040 | } | |
5f39d397 | 1041 | if (btrfs_header_nritems(mid) == 1) { |
79f95c82 CM |
1042 | /* |
1043 | * we're not allowed to leave a node with one item in the | |
1044 | * tree during a delete. A deletion from lower in the tree | |
1045 | * could try to delete the only pointer in this node. | |
1046 | * So, pull some keys from the left. | |
1047 | * There has to be a left pointer at this point because | |
1048 | * otherwise we would have pulled some pointers from the | |
1049 | * right | |
1050 | */ | |
5f39d397 CM |
1051 | BUG_ON(!left); |
1052 | wret = balance_node_right(trans, root, mid, left); | |
54aa1f4d | 1053 | if (wret < 0) { |
79f95c82 | 1054 | ret = wret; |
54aa1f4d CM |
1055 | goto enospc; |
1056 | } | |
bce4eae9 CM |
1057 | if (wret == 1) { |
1058 | wret = push_node_left(trans, root, left, mid, 1); | |
1059 | if (wret < 0) | |
1060 | ret = wret; | |
1061 | } | |
79f95c82 CM |
1062 | BUG_ON(wret == 1); |
1063 | } | |
5f39d397 | 1064 | if (btrfs_header_nritems(mid) == 0) { |
5f39d397 | 1065 | clean_tree_block(trans, root, mid); |
925baedd | 1066 | btrfs_tree_unlock(mid); |
e089f05c | 1067 | wret = del_ptr(trans, root, path, level + 1, pslot); |
bb803951 CM |
1068 | if (wret) |
1069 | ret = wret; | |
f0486c68 | 1070 | root_sub_used(root, mid->len); |
66d7e7f0 | 1071 | btrfs_free_tree_block(trans, root, mid, 0, 1, 0); |
3083ee2e | 1072 | free_extent_buffer_stale(mid); |
f0486c68 | 1073 | mid = NULL; |
79f95c82 CM |
1074 | } else { |
1075 | /* update the parent key to reflect our changes */ | |
5f39d397 CM |
1076 | struct btrfs_disk_key mid_key; |
1077 | btrfs_node_key(mid, &mid_key, 0); | |
1078 | btrfs_set_node_key(parent, &mid_key, pslot); | |
1079 | btrfs_mark_buffer_dirty(parent); | |
79f95c82 | 1080 | } |
bb803951 | 1081 | |
79f95c82 | 1082 | /* update the path */ |
5f39d397 CM |
1083 | if (left) { |
1084 | if (btrfs_header_nritems(left) > orig_slot) { | |
1085 | extent_buffer_get(left); | |
925baedd | 1086 | /* left was locked after cow */ |
5f39d397 | 1087 | path->nodes[level] = left; |
bb803951 CM |
1088 | path->slots[level + 1] -= 1; |
1089 | path->slots[level] = orig_slot; | |
925baedd CM |
1090 | if (mid) { |
1091 | btrfs_tree_unlock(mid); | |
5f39d397 | 1092 | free_extent_buffer(mid); |
925baedd | 1093 | } |
bb803951 | 1094 | } else { |
5f39d397 | 1095 | orig_slot -= btrfs_header_nritems(left); |
bb803951 CM |
1096 | path->slots[level] = orig_slot; |
1097 | } | |
1098 | } | |
79f95c82 | 1099 | /* double check we haven't messed things up */ |
e20d96d6 | 1100 | if (orig_ptr != |
5f39d397 | 1101 | btrfs_node_blockptr(path->nodes[level], path->slots[level])) |
79f95c82 | 1102 | BUG(); |
54aa1f4d | 1103 | enospc: |
925baedd CM |
1104 | if (right) { |
1105 | btrfs_tree_unlock(right); | |
5f39d397 | 1106 | free_extent_buffer(right); |
925baedd CM |
1107 | } |
1108 | if (left) { | |
1109 | if (path->nodes[level] != left) | |
1110 | btrfs_tree_unlock(left); | |
5f39d397 | 1111 | free_extent_buffer(left); |
925baedd | 1112 | } |
bb803951 CM |
1113 | return ret; |
1114 | } | |
1115 | ||
d352ac68 CM |
1116 | /* Node balancing for insertion. Here we only split or push nodes around |
1117 | * when they are completely full. This is also done top down, so we | |
1118 | * have to be pessimistic. | |
1119 | */ | |
d397712b | 1120 | static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans, |
98ed5174 CM |
1121 | struct btrfs_root *root, |
1122 | struct btrfs_path *path, int level) | |
e66f709b | 1123 | { |
5f39d397 CM |
1124 | struct extent_buffer *right = NULL; |
1125 | struct extent_buffer *mid; | |
1126 | struct extent_buffer *left = NULL; | |
1127 | struct extent_buffer *parent = NULL; | |
e66f709b CM |
1128 | int ret = 0; |
1129 | int wret; | |
1130 | int pslot; | |
1131 | int orig_slot = path->slots[level]; | |
e66f709b CM |
1132 | |
1133 | if (level == 0) | |
1134 | return 1; | |
1135 | ||
5f39d397 | 1136 | mid = path->nodes[level]; |
7bb86316 | 1137 | WARN_ON(btrfs_header_generation(mid) != trans->transid); |
e66f709b | 1138 | |
a05a9bb1 | 1139 | if (level < BTRFS_MAX_LEVEL - 1) { |
5f39d397 | 1140 | parent = path->nodes[level + 1]; |
a05a9bb1 LZ |
1141 | pslot = path->slots[level + 1]; |
1142 | } | |
e66f709b | 1143 | |
5f39d397 | 1144 | if (!parent) |
e66f709b | 1145 | return 1; |
e66f709b | 1146 | |
5f39d397 | 1147 | left = read_node_slot(root, parent, pslot - 1); |
e66f709b CM |
1148 | |
1149 | /* first, try to make some room in the middle buffer */ | |
5f39d397 | 1150 | if (left) { |
e66f709b | 1151 | u32 left_nr; |
925baedd CM |
1152 | |
1153 | btrfs_tree_lock(left); | |
b4ce94de CM |
1154 | btrfs_set_lock_blocking(left); |
1155 | ||
5f39d397 | 1156 | left_nr = btrfs_header_nritems(left); |
33ade1f8 CM |
1157 | if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) { |
1158 | wret = 1; | |
1159 | } else { | |
5f39d397 | 1160 | ret = btrfs_cow_block(trans, root, left, parent, |
9fa8cfe7 | 1161 | pslot - 1, &left); |
54aa1f4d CM |
1162 | if (ret) |
1163 | wret = 1; | |
1164 | else { | |
54aa1f4d | 1165 | wret = push_node_left(trans, root, |
971a1f66 | 1166 | left, mid, 0); |
54aa1f4d | 1167 | } |
33ade1f8 | 1168 | } |
e66f709b CM |
1169 | if (wret < 0) |
1170 | ret = wret; | |
1171 | if (wret == 0) { | |
5f39d397 | 1172 | struct btrfs_disk_key disk_key; |
e66f709b | 1173 | orig_slot += left_nr; |
5f39d397 CM |
1174 | btrfs_node_key(mid, &disk_key, 0); |
1175 | btrfs_set_node_key(parent, &disk_key, pslot); | |
1176 | btrfs_mark_buffer_dirty(parent); | |
1177 | if (btrfs_header_nritems(left) > orig_slot) { | |
1178 | path->nodes[level] = left; | |
e66f709b CM |
1179 | path->slots[level + 1] -= 1; |
1180 | path->slots[level] = orig_slot; | |
925baedd | 1181 | btrfs_tree_unlock(mid); |
5f39d397 | 1182 | free_extent_buffer(mid); |
e66f709b CM |
1183 | } else { |
1184 | orig_slot -= | |
5f39d397 | 1185 | btrfs_header_nritems(left); |
e66f709b | 1186 | path->slots[level] = orig_slot; |
925baedd | 1187 | btrfs_tree_unlock(left); |
5f39d397 | 1188 | free_extent_buffer(left); |
e66f709b | 1189 | } |
e66f709b CM |
1190 | return 0; |
1191 | } | |
925baedd | 1192 | btrfs_tree_unlock(left); |
5f39d397 | 1193 | free_extent_buffer(left); |
e66f709b | 1194 | } |
925baedd | 1195 | right = read_node_slot(root, parent, pslot + 1); |
e66f709b CM |
1196 | |
1197 | /* | |
1198 | * then try to empty the right most buffer into the middle | |
1199 | */ | |
5f39d397 | 1200 | if (right) { |
33ade1f8 | 1201 | u32 right_nr; |
b4ce94de | 1202 | |
925baedd | 1203 | btrfs_tree_lock(right); |
b4ce94de CM |
1204 | btrfs_set_lock_blocking(right); |
1205 | ||
5f39d397 | 1206 | right_nr = btrfs_header_nritems(right); |
33ade1f8 CM |
1207 | if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) { |
1208 | wret = 1; | |
1209 | } else { | |
5f39d397 CM |
1210 | ret = btrfs_cow_block(trans, root, right, |
1211 | parent, pslot + 1, | |
9fa8cfe7 | 1212 | &right); |
54aa1f4d CM |
1213 | if (ret) |
1214 | wret = 1; | |
1215 | else { | |
54aa1f4d | 1216 | wret = balance_node_right(trans, root, |
5f39d397 | 1217 | right, mid); |
54aa1f4d | 1218 | } |
33ade1f8 | 1219 | } |
e66f709b CM |
1220 | if (wret < 0) |
1221 | ret = wret; | |
1222 | if (wret == 0) { | |
5f39d397 CM |
1223 | struct btrfs_disk_key disk_key; |
1224 | ||
1225 | btrfs_node_key(right, &disk_key, 0); | |
1226 | btrfs_set_node_key(parent, &disk_key, pslot + 1); | |
1227 | btrfs_mark_buffer_dirty(parent); | |
1228 | ||
1229 | if (btrfs_header_nritems(mid) <= orig_slot) { | |
1230 | path->nodes[level] = right; | |
e66f709b CM |
1231 | path->slots[level + 1] += 1; |
1232 | path->slots[level] = orig_slot - | |
5f39d397 | 1233 | btrfs_header_nritems(mid); |
925baedd | 1234 | btrfs_tree_unlock(mid); |
5f39d397 | 1235 | free_extent_buffer(mid); |
e66f709b | 1236 | } else { |
925baedd | 1237 | btrfs_tree_unlock(right); |
5f39d397 | 1238 | free_extent_buffer(right); |
e66f709b | 1239 | } |
e66f709b CM |
1240 | return 0; |
1241 | } | |
925baedd | 1242 | btrfs_tree_unlock(right); |
5f39d397 | 1243 | free_extent_buffer(right); |
e66f709b | 1244 | } |
e66f709b CM |
1245 | return 1; |
1246 | } | |
1247 | ||
3c69faec | 1248 | /* |
d352ac68 CM |
1249 | * readahead one full node of leaves, finding things that are close |
1250 | * to the block in 'slot', and triggering ra on them. | |
3c69faec | 1251 | */ |
c8c42864 CM |
1252 | static void reada_for_search(struct btrfs_root *root, |
1253 | struct btrfs_path *path, | |
1254 | int level, int slot, u64 objectid) | |
3c69faec | 1255 | { |
5f39d397 | 1256 | struct extent_buffer *node; |
01f46658 | 1257 | struct btrfs_disk_key disk_key; |
3c69faec | 1258 | u32 nritems; |
3c69faec | 1259 | u64 search; |
a7175319 | 1260 | u64 target; |
6b80053d | 1261 | u64 nread = 0; |
cb25c2ea | 1262 | u64 gen; |
3c69faec | 1263 | int direction = path->reada; |
5f39d397 | 1264 | struct extent_buffer *eb; |
6b80053d CM |
1265 | u32 nr; |
1266 | u32 blocksize; | |
1267 | u32 nscan = 0; | |
db94535d | 1268 | |
a6b6e75e | 1269 | if (level != 1) |
6702ed49 CM |
1270 | return; |
1271 | ||
1272 | if (!path->nodes[level]) | |
3c69faec CM |
1273 | return; |
1274 | ||
5f39d397 | 1275 | node = path->nodes[level]; |
925baedd | 1276 | |
3c69faec | 1277 | search = btrfs_node_blockptr(node, slot); |
6b80053d CM |
1278 | blocksize = btrfs_level_size(root, level - 1); |
1279 | eb = btrfs_find_tree_block(root, search, blocksize); | |
5f39d397 CM |
1280 | if (eb) { |
1281 | free_extent_buffer(eb); | |
3c69faec CM |
1282 | return; |
1283 | } | |
1284 | ||
a7175319 | 1285 | target = search; |
6b80053d | 1286 | |
5f39d397 | 1287 | nritems = btrfs_header_nritems(node); |
6b80053d | 1288 | nr = slot; |
25b8b936 | 1289 | |
d397712b | 1290 | while (1) { |
6b80053d CM |
1291 | if (direction < 0) { |
1292 | if (nr == 0) | |
1293 | break; | |
1294 | nr--; | |
1295 | } else if (direction > 0) { | |
1296 | nr++; | |
1297 | if (nr >= nritems) | |
1298 | break; | |
3c69faec | 1299 | } |
01f46658 CM |
1300 | if (path->reada < 0 && objectid) { |
1301 | btrfs_node_key(node, &disk_key, nr); | |
1302 | if (btrfs_disk_key_objectid(&disk_key) != objectid) | |
1303 | break; | |
1304 | } | |
6b80053d | 1305 | search = btrfs_node_blockptr(node, nr); |
a7175319 CM |
1306 | if ((search <= target && target - search <= 65536) || |
1307 | (search > target && search - target <= 65536)) { | |
cb25c2ea | 1308 | gen = btrfs_node_ptr_generation(node, nr); |
cb25c2ea | 1309 | readahead_tree_block(root, search, blocksize, gen); |
6b80053d CM |
1310 | nread += blocksize; |
1311 | } | |
1312 | nscan++; | |
a7175319 | 1313 | if ((nread > 65536 || nscan > 32)) |
6b80053d | 1314 | break; |
3c69faec CM |
1315 | } |
1316 | } | |
925baedd | 1317 | |
b4ce94de CM |
1318 | /* |
1319 | * returns -EAGAIN if it had to drop the path, or zero if everything was in | |
1320 | * cache | |
1321 | */ | |
1322 | static noinline int reada_for_balance(struct btrfs_root *root, | |
1323 | struct btrfs_path *path, int level) | |
1324 | { | |
1325 | int slot; | |
1326 | int nritems; | |
1327 | struct extent_buffer *parent; | |
1328 | struct extent_buffer *eb; | |
1329 | u64 gen; | |
1330 | u64 block1 = 0; | |
1331 | u64 block2 = 0; | |
1332 | int ret = 0; | |
1333 | int blocksize; | |
1334 | ||
8c594ea8 | 1335 | parent = path->nodes[level + 1]; |
b4ce94de CM |
1336 | if (!parent) |
1337 | return 0; | |
1338 | ||
1339 | nritems = btrfs_header_nritems(parent); | |
8c594ea8 | 1340 | slot = path->slots[level + 1]; |
b4ce94de CM |
1341 | blocksize = btrfs_level_size(root, level); |
1342 | ||
1343 | if (slot > 0) { | |
1344 | block1 = btrfs_node_blockptr(parent, slot - 1); | |
1345 | gen = btrfs_node_ptr_generation(parent, slot - 1); | |
1346 | eb = btrfs_find_tree_block(root, block1, blocksize); | |
1347 | if (eb && btrfs_buffer_uptodate(eb, gen)) | |
1348 | block1 = 0; | |
1349 | free_extent_buffer(eb); | |
1350 | } | |
8c594ea8 | 1351 | if (slot + 1 < nritems) { |
b4ce94de CM |
1352 | block2 = btrfs_node_blockptr(parent, slot + 1); |
1353 | gen = btrfs_node_ptr_generation(parent, slot + 1); | |
1354 | eb = btrfs_find_tree_block(root, block2, blocksize); | |
1355 | if (eb && btrfs_buffer_uptodate(eb, gen)) | |
1356 | block2 = 0; | |
1357 | free_extent_buffer(eb); | |
1358 | } | |
1359 | if (block1 || block2) { | |
1360 | ret = -EAGAIN; | |
8c594ea8 CM |
1361 | |
1362 | /* release the whole path */ | |
b3b4aa74 | 1363 | btrfs_release_path(path); |
8c594ea8 CM |
1364 | |
1365 | /* read the blocks */ | |
b4ce94de CM |
1366 | if (block1) |
1367 | readahead_tree_block(root, block1, blocksize, 0); | |
1368 | if (block2) | |
1369 | readahead_tree_block(root, block2, blocksize, 0); | |
1370 | ||
1371 | if (block1) { | |
1372 | eb = read_tree_block(root, block1, blocksize, 0); | |
1373 | free_extent_buffer(eb); | |
1374 | } | |
8c594ea8 | 1375 | if (block2) { |
b4ce94de CM |
1376 | eb = read_tree_block(root, block2, blocksize, 0); |
1377 | free_extent_buffer(eb); | |
1378 | } | |
1379 | } | |
1380 | return ret; | |
1381 | } | |
1382 | ||
1383 | ||
d352ac68 | 1384 | /* |
d397712b CM |
1385 | * when we walk down the tree, it is usually safe to unlock the higher layers |
1386 | * in the tree. The exceptions are when our path goes through slot 0, because | |
1387 | * operations on the tree might require changing key pointers higher up in the | |
1388 | * tree. | |
d352ac68 | 1389 | * |
d397712b CM |
1390 | * callers might also have set path->keep_locks, which tells this code to keep |
1391 | * the lock if the path points to the last slot in the block. This is part of | |
1392 | * walking through the tree, and selecting the next slot in the higher block. | |
d352ac68 | 1393 | * |
d397712b CM |
1394 | * lowest_unlock sets the lowest level in the tree we're allowed to unlock. so |
1395 | * if lowest_unlock is 1, level 0 won't be unlocked | |
d352ac68 | 1396 | */ |
e02119d5 | 1397 | static noinline void unlock_up(struct btrfs_path *path, int level, |
f7c79f30 CM |
1398 | int lowest_unlock, int min_write_lock_level, |
1399 | int *write_lock_level) | |
925baedd CM |
1400 | { |
1401 | int i; | |
1402 | int skip_level = level; | |
051e1b9f | 1403 | int no_skips = 0; |
925baedd CM |
1404 | struct extent_buffer *t; |
1405 | ||
1406 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { | |
1407 | if (!path->nodes[i]) | |
1408 | break; | |
1409 | if (!path->locks[i]) | |
1410 | break; | |
051e1b9f | 1411 | if (!no_skips && path->slots[i] == 0) { |
925baedd CM |
1412 | skip_level = i + 1; |
1413 | continue; | |
1414 | } | |
051e1b9f | 1415 | if (!no_skips && path->keep_locks) { |
925baedd CM |
1416 | u32 nritems; |
1417 | t = path->nodes[i]; | |
1418 | nritems = btrfs_header_nritems(t); | |
051e1b9f | 1419 | if (nritems < 1 || path->slots[i] >= nritems - 1) { |
925baedd CM |
1420 | skip_level = i + 1; |
1421 | continue; | |
1422 | } | |
1423 | } | |
051e1b9f CM |
1424 | if (skip_level < i && i >= lowest_unlock) |
1425 | no_skips = 1; | |
1426 | ||
925baedd CM |
1427 | t = path->nodes[i]; |
1428 | if (i >= lowest_unlock && i > skip_level && path->locks[i]) { | |
bd681513 | 1429 | btrfs_tree_unlock_rw(t, path->locks[i]); |
925baedd | 1430 | path->locks[i] = 0; |
f7c79f30 CM |
1431 | if (write_lock_level && |
1432 | i > min_write_lock_level && | |
1433 | i <= *write_lock_level) { | |
1434 | *write_lock_level = i - 1; | |
1435 | } | |
925baedd CM |
1436 | } |
1437 | } | |
1438 | } | |
1439 | ||
b4ce94de CM |
1440 | /* |
1441 | * This releases any locks held in the path starting at level and | |
1442 | * going all the way up to the root. | |
1443 | * | |
1444 | * btrfs_search_slot will keep the lock held on higher nodes in a few | |
1445 | * corner cases, such as COW of the block at slot zero in the node. This | |
1446 | * ignores those rules, and it should only be called when there are no | |
1447 | * more updates to be done higher up in the tree. | |
1448 | */ | |
1449 | noinline void btrfs_unlock_up_safe(struct btrfs_path *path, int level) | |
1450 | { | |
1451 | int i; | |
1452 | ||
5d4f98a2 | 1453 | if (path->keep_locks) |
b4ce94de CM |
1454 | return; |
1455 | ||
1456 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { | |
1457 | if (!path->nodes[i]) | |
12f4dacc | 1458 | continue; |
b4ce94de | 1459 | if (!path->locks[i]) |
12f4dacc | 1460 | continue; |
bd681513 | 1461 | btrfs_tree_unlock_rw(path->nodes[i], path->locks[i]); |
b4ce94de CM |
1462 | path->locks[i] = 0; |
1463 | } | |
1464 | } | |
1465 | ||
c8c42864 CM |
1466 | /* |
1467 | * helper function for btrfs_search_slot. The goal is to find a block | |
1468 | * in cache without setting the path to blocking. If we find the block | |
1469 | * we return zero and the path is unchanged. | |
1470 | * | |
1471 | * If we can't find the block, we set the path blocking and do some | |
1472 | * reada. -EAGAIN is returned and the search must be repeated. | |
1473 | */ | |
1474 | static int | |
1475 | read_block_for_search(struct btrfs_trans_handle *trans, | |
1476 | struct btrfs_root *root, struct btrfs_path *p, | |
1477 | struct extent_buffer **eb_ret, int level, int slot, | |
1478 | struct btrfs_key *key) | |
1479 | { | |
1480 | u64 blocknr; | |
1481 | u64 gen; | |
1482 | u32 blocksize; | |
1483 | struct extent_buffer *b = *eb_ret; | |
1484 | struct extent_buffer *tmp; | |
76a05b35 | 1485 | int ret; |
c8c42864 CM |
1486 | |
1487 | blocknr = btrfs_node_blockptr(b, slot); | |
1488 | gen = btrfs_node_ptr_generation(b, slot); | |
1489 | blocksize = btrfs_level_size(root, level - 1); | |
1490 | ||
1491 | tmp = btrfs_find_tree_block(root, blocknr, blocksize); | |
cb44921a CM |
1492 | if (tmp) { |
1493 | if (btrfs_buffer_uptodate(tmp, 0)) { | |
1494 | if (btrfs_buffer_uptodate(tmp, gen)) { | |
1495 | /* | |
1496 | * we found an up to date block without | |
1497 | * sleeping, return | |
1498 | * right away | |
1499 | */ | |
1500 | *eb_ret = tmp; | |
1501 | return 0; | |
1502 | } | |
1503 | /* the pages were up to date, but we failed | |
1504 | * the generation number check. Do a full | |
1505 | * read for the generation number that is correct. | |
1506 | * We must do this without dropping locks so | |
1507 | * we can trust our generation number | |
1508 | */ | |
1509 | free_extent_buffer(tmp); | |
bd681513 CM |
1510 | btrfs_set_path_blocking(p); |
1511 | ||
cb44921a CM |
1512 | tmp = read_tree_block(root, blocknr, blocksize, gen); |
1513 | if (tmp && btrfs_buffer_uptodate(tmp, gen)) { | |
1514 | *eb_ret = tmp; | |
1515 | return 0; | |
1516 | } | |
1517 | free_extent_buffer(tmp); | |
b3b4aa74 | 1518 | btrfs_release_path(p); |
cb44921a CM |
1519 | return -EIO; |
1520 | } | |
c8c42864 CM |
1521 | } |
1522 | ||
1523 | /* | |
1524 | * reduce lock contention at high levels | |
1525 | * of the btree by dropping locks before | |
76a05b35 CM |
1526 | * we read. Don't release the lock on the current |
1527 | * level because we need to walk this node to figure | |
1528 | * out which blocks to read. | |
c8c42864 | 1529 | */ |
8c594ea8 CM |
1530 | btrfs_unlock_up_safe(p, level + 1); |
1531 | btrfs_set_path_blocking(p); | |
1532 | ||
cb44921a | 1533 | free_extent_buffer(tmp); |
c8c42864 CM |
1534 | if (p->reada) |
1535 | reada_for_search(root, p, level, slot, key->objectid); | |
1536 | ||
b3b4aa74 | 1537 | btrfs_release_path(p); |
76a05b35 CM |
1538 | |
1539 | ret = -EAGAIN; | |
5bdd3536 | 1540 | tmp = read_tree_block(root, blocknr, blocksize, 0); |
76a05b35 CM |
1541 | if (tmp) { |
1542 | /* | |
1543 | * If the read above didn't mark this buffer up to date, | |
1544 | * it will never end up being up to date. Set ret to EIO now | |
1545 | * and give up so that our caller doesn't loop forever | |
1546 | * on our EAGAINs. | |
1547 | */ | |
1548 | if (!btrfs_buffer_uptodate(tmp, 0)) | |
1549 | ret = -EIO; | |
c8c42864 | 1550 | free_extent_buffer(tmp); |
76a05b35 CM |
1551 | } |
1552 | return ret; | |
c8c42864 CM |
1553 | } |
1554 | ||
1555 | /* | |
1556 | * helper function for btrfs_search_slot. This does all of the checks | |
1557 | * for node-level blocks and does any balancing required based on | |
1558 | * the ins_len. | |
1559 | * | |
1560 | * If no extra work was required, zero is returned. If we had to | |
1561 | * drop the path, -EAGAIN is returned and btrfs_search_slot must | |
1562 | * start over | |
1563 | */ | |
1564 | static int | |
1565 | setup_nodes_for_search(struct btrfs_trans_handle *trans, | |
1566 | struct btrfs_root *root, struct btrfs_path *p, | |
bd681513 CM |
1567 | struct extent_buffer *b, int level, int ins_len, |
1568 | int *write_lock_level) | |
c8c42864 CM |
1569 | { |
1570 | int ret; | |
1571 | if ((p->search_for_split || ins_len > 0) && btrfs_header_nritems(b) >= | |
1572 | BTRFS_NODEPTRS_PER_BLOCK(root) - 3) { | |
1573 | int sret; | |
1574 | ||
bd681513 CM |
1575 | if (*write_lock_level < level + 1) { |
1576 | *write_lock_level = level + 1; | |
1577 | btrfs_release_path(p); | |
1578 | goto again; | |
1579 | } | |
1580 | ||
c8c42864 CM |
1581 | sret = reada_for_balance(root, p, level); |
1582 | if (sret) | |
1583 | goto again; | |
1584 | ||
1585 | btrfs_set_path_blocking(p); | |
1586 | sret = split_node(trans, root, p, level); | |
bd681513 | 1587 | btrfs_clear_path_blocking(p, NULL, 0); |
c8c42864 CM |
1588 | |
1589 | BUG_ON(sret > 0); | |
1590 | if (sret) { | |
1591 | ret = sret; | |
1592 | goto done; | |
1593 | } | |
1594 | b = p->nodes[level]; | |
1595 | } else if (ins_len < 0 && btrfs_header_nritems(b) < | |
cfbb9308 | 1596 | BTRFS_NODEPTRS_PER_BLOCK(root) / 2) { |
c8c42864 CM |
1597 | int sret; |
1598 | ||
bd681513 CM |
1599 | if (*write_lock_level < level + 1) { |
1600 | *write_lock_level = level + 1; | |
1601 | btrfs_release_path(p); | |
1602 | goto again; | |
1603 | } | |
1604 | ||
c8c42864 CM |
1605 | sret = reada_for_balance(root, p, level); |
1606 | if (sret) | |
1607 | goto again; | |
1608 | ||
1609 | btrfs_set_path_blocking(p); | |
1610 | sret = balance_level(trans, root, p, level); | |
bd681513 | 1611 | btrfs_clear_path_blocking(p, NULL, 0); |
c8c42864 CM |
1612 | |
1613 | if (sret) { | |
1614 | ret = sret; | |
1615 | goto done; | |
1616 | } | |
1617 | b = p->nodes[level]; | |
1618 | if (!b) { | |
b3b4aa74 | 1619 | btrfs_release_path(p); |
c8c42864 CM |
1620 | goto again; |
1621 | } | |
1622 | BUG_ON(btrfs_header_nritems(b) == 1); | |
1623 | } | |
1624 | return 0; | |
1625 | ||
1626 | again: | |
1627 | ret = -EAGAIN; | |
1628 | done: | |
1629 | return ret; | |
1630 | } | |
1631 | ||
74123bd7 CM |
1632 | /* |
1633 | * look for key in the tree. path is filled in with nodes along the way | |
1634 | * if key is found, we return zero and you can find the item in the leaf | |
1635 | * level of the path (level 0) | |
1636 | * | |
1637 | * If the key isn't found, the path points to the slot where it should | |
aa5d6bed CM |
1638 | * be inserted, and 1 is returned. If there are other errors during the |
1639 | * search a negative error number is returned. | |
97571fd0 CM |
1640 | * |
1641 | * if ins_len > 0, nodes and leaves will be split as we walk down the | |
1642 | * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if | |
1643 | * possible) | |
74123bd7 | 1644 | */ |
e089f05c CM |
1645 | int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root |
1646 | *root, struct btrfs_key *key, struct btrfs_path *p, int | |
1647 | ins_len, int cow) | |
be0e5c09 | 1648 | { |
5f39d397 | 1649 | struct extent_buffer *b; |
be0e5c09 CM |
1650 | int slot; |
1651 | int ret; | |
33c66f43 | 1652 | int err; |
be0e5c09 | 1653 | int level; |
925baedd | 1654 | int lowest_unlock = 1; |
bd681513 CM |
1655 | int root_lock; |
1656 | /* everything at write_lock_level or lower must be write locked */ | |
1657 | int write_lock_level = 0; | |
9f3a7427 | 1658 | u8 lowest_level = 0; |
f7c79f30 | 1659 | int min_write_lock_level; |
9f3a7427 | 1660 | |
6702ed49 | 1661 | lowest_level = p->lowest_level; |
323ac95b | 1662 | WARN_ON(lowest_level && ins_len > 0); |
22b0ebda | 1663 | WARN_ON(p->nodes[0] != NULL); |
25179201 | 1664 | |
bd681513 | 1665 | if (ins_len < 0) { |
925baedd | 1666 | lowest_unlock = 2; |
65b51a00 | 1667 | |
bd681513 CM |
1668 | /* when we are removing items, we might have to go up to level |
1669 | * two as we update tree pointers Make sure we keep write | |
1670 | * for those levels as well | |
1671 | */ | |
1672 | write_lock_level = 2; | |
1673 | } else if (ins_len > 0) { | |
1674 | /* | |
1675 | * for inserting items, make sure we have a write lock on | |
1676 | * level 1 so we can update keys | |
1677 | */ | |
1678 | write_lock_level = 1; | |
1679 | } | |
1680 | ||
1681 | if (!cow) | |
1682 | write_lock_level = -1; | |
1683 | ||
1684 | if (cow && (p->keep_locks || p->lowest_level)) | |
1685 | write_lock_level = BTRFS_MAX_LEVEL; | |
1686 | ||
f7c79f30 CM |
1687 | min_write_lock_level = write_lock_level; |
1688 | ||
bb803951 | 1689 | again: |
bd681513 CM |
1690 | /* |
1691 | * we try very hard to do read locks on the root | |
1692 | */ | |
1693 | root_lock = BTRFS_READ_LOCK; | |
1694 | level = 0; | |
5d4f98a2 | 1695 | if (p->search_commit_root) { |
bd681513 CM |
1696 | /* |
1697 | * the commit roots are read only | |
1698 | * so we always do read locks | |
1699 | */ | |
5d4f98a2 YZ |
1700 | b = root->commit_root; |
1701 | extent_buffer_get(b); | |
bd681513 | 1702 | level = btrfs_header_level(b); |
5d4f98a2 | 1703 | if (!p->skip_locking) |
bd681513 | 1704 | btrfs_tree_read_lock(b); |
5d4f98a2 | 1705 | } else { |
bd681513 | 1706 | if (p->skip_locking) { |
5d4f98a2 | 1707 | b = btrfs_root_node(root); |
bd681513 CM |
1708 | level = btrfs_header_level(b); |
1709 | } else { | |
1710 | /* we don't know the level of the root node | |
1711 | * until we actually have it read locked | |
1712 | */ | |
1713 | b = btrfs_read_lock_root_node(root); | |
1714 | level = btrfs_header_level(b); | |
1715 | if (level <= write_lock_level) { | |
1716 | /* whoops, must trade for write lock */ | |
1717 | btrfs_tree_read_unlock(b); | |
1718 | free_extent_buffer(b); | |
1719 | b = btrfs_lock_root_node(root); | |
1720 | root_lock = BTRFS_WRITE_LOCK; | |
1721 | ||
1722 | /* the level might have changed, check again */ | |
1723 | level = btrfs_header_level(b); | |
1724 | } | |
1725 | } | |
5d4f98a2 | 1726 | } |
bd681513 CM |
1727 | p->nodes[level] = b; |
1728 | if (!p->skip_locking) | |
1729 | p->locks[level] = root_lock; | |
925baedd | 1730 | |
eb60ceac | 1731 | while (b) { |
5f39d397 | 1732 | level = btrfs_header_level(b); |
65b51a00 CM |
1733 | |
1734 | /* | |
1735 | * setup the path here so we can release it under lock | |
1736 | * contention with the cow code | |
1737 | */ | |
02217ed2 | 1738 | if (cow) { |
c8c42864 CM |
1739 | /* |
1740 | * if we don't really need to cow this block | |
1741 | * then we don't want to set the path blocking, | |
1742 | * so we test it here | |
1743 | */ | |
5d4f98a2 | 1744 | if (!should_cow_block(trans, root, b)) |
65b51a00 | 1745 | goto cow_done; |
5d4f98a2 | 1746 | |
b4ce94de CM |
1747 | btrfs_set_path_blocking(p); |
1748 | ||
bd681513 CM |
1749 | /* |
1750 | * must have write locks on this node and the | |
1751 | * parent | |
1752 | */ | |
1753 | if (level + 1 > write_lock_level) { | |
1754 | write_lock_level = level + 1; | |
1755 | btrfs_release_path(p); | |
1756 | goto again; | |
1757 | } | |
1758 | ||
33c66f43 YZ |
1759 | err = btrfs_cow_block(trans, root, b, |
1760 | p->nodes[level + 1], | |
1761 | p->slots[level + 1], &b); | |
1762 | if (err) { | |
33c66f43 | 1763 | ret = err; |
65b51a00 | 1764 | goto done; |
54aa1f4d | 1765 | } |
02217ed2 | 1766 | } |
65b51a00 | 1767 | cow_done: |
02217ed2 | 1768 | BUG_ON(!cow && ins_len); |
65b51a00 | 1769 | |
eb60ceac | 1770 | p->nodes[level] = b; |
bd681513 | 1771 | btrfs_clear_path_blocking(p, NULL, 0); |
b4ce94de CM |
1772 | |
1773 | /* | |
1774 | * we have a lock on b and as long as we aren't changing | |
1775 | * the tree, there is no way to for the items in b to change. | |
1776 | * It is safe to drop the lock on our parent before we | |
1777 | * go through the expensive btree search on b. | |
1778 | * | |
1779 | * If cow is true, then we might be changing slot zero, | |
1780 | * which may require changing the parent. So, we can't | |
1781 | * drop the lock until after we know which slot we're | |
1782 | * operating on. | |
1783 | */ | |
1784 | if (!cow) | |
1785 | btrfs_unlock_up_safe(p, level + 1); | |
1786 | ||
5f39d397 | 1787 | ret = bin_search(b, key, level, &slot); |
b4ce94de | 1788 | |
5f39d397 | 1789 | if (level != 0) { |
33c66f43 YZ |
1790 | int dec = 0; |
1791 | if (ret && slot > 0) { | |
1792 | dec = 1; | |
be0e5c09 | 1793 | slot -= 1; |
33c66f43 | 1794 | } |
be0e5c09 | 1795 | p->slots[level] = slot; |
33c66f43 | 1796 | err = setup_nodes_for_search(trans, root, p, b, level, |
bd681513 | 1797 | ins_len, &write_lock_level); |
33c66f43 | 1798 | if (err == -EAGAIN) |
c8c42864 | 1799 | goto again; |
33c66f43 YZ |
1800 | if (err) { |
1801 | ret = err; | |
c8c42864 | 1802 | goto done; |
33c66f43 | 1803 | } |
c8c42864 CM |
1804 | b = p->nodes[level]; |
1805 | slot = p->slots[level]; | |
b4ce94de | 1806 | |
bd681513 CM |
1807 | /* |
1808 | * slot 0 is special, if we change the key | |
1809 | * we have to update the parent pointer | |
1810 | * which means we must have a write lock | |
1811 | * on the parent | |
1812 | */ | |
1813 | if (slot == 0 && cow && | |
1814 | write_lock_level < level + 1) { | |
1815 | write_lock_level = level + 1; | |
1816 | btrfs_release_path(p); | |
1817 | goto again; | |
1818 | } | |
1819 | ||
f7c79f30 CM |
1820 | unlock_up(p, level, lowest_unlock, |
1821 | min_write_lock_level, &write_lock_level); | |
f9efa9c7 | 1822 | |
925baedd | 1823 | if (level == lowest_level) { |
33c66f43 YZ |
1824 | if (dec) |
1825 | p->slots[level]++; | |
5b21f2ed | 1826 | goto done; |
925baedd | 1827 | } |
ca7a79ad | 1828 | |
33c66f43 | 1829 | err = read_block_for_search(trans, root, p, |
c8c42864 | 1830 | &b, level, slot, key); |
33c66f43 | 1831 | if (err == -EAGAIN) |
c8c42864 | 1832 | goto again; |
33c66f43 YZ |
1833 | if (err) { |
1834 | ret = err; | |
76a05b35 | 1835 | goto done; |
33c66f43 | 1836 | } |
76a05b35 | 1837 | |
b4ce94de | 1838 | if (!p->skip_locking) { |
bd681513 CM |
1839 | level = btrfs_header_level(b); |
1840 | if (level <= write_lock_level) { | |
1841 | err = btrfs_try_tree_write_lock(b); | |
1842 | if (!err) { | |
1843 | btrfs_set_path_blocking(p); | |
1844 | btrfs_tree_lock(b); | |
1845 | btrfs_clear_path_blocking(p, b, | |
1846 | BTRFS_WRITE_LOCK); | |
1847 | } | |
1848 | p->locks[level] = BTRFS_WRITE_LOCK; | |
1849 | } else { | |
1850 | err = btrfs_try_tree_read_lock(b); | |
1851 | if (!err) { | |
1852 | btrfs_set_path_blocking(p); | |
1853 | btrfs_tree_read_lock(b); | |
1854 | btrfs_clear_path_blocking(p, b, | |
1855 | BTRFS_READ_LOCK); | |
1856 | } | |
1857 | p->locks[level] = BTRFS_READ_LOCK; | |
b4ce94de | 1858 | } |
bd681513 | 1859 | p->nodes[level] = b; |
b4ce94de | 1860 | } |
be0e5c09 CM |
1861 | } else { |
1862 | p->slots[level] = slot; | |
87b29b20 YZ |
1863 | if (ins_len > 0 && |
1864 | btrfs_leaf_free_space(root, b) < ins_len) { | |
bd681513 CM |
1865 | if (write_lock_level < 1) { |
1866 | write_lock_level = 1; | |
1867 | btrfs_release_path(p); | |
1868 | goto again; | |
1869 | } | |
1870 | ||
b4ce94de | 1871 | btrfs_set_path_blocking(p); |
33c66f43 YZ |
1872 | err = split_leaf(trans, root, key, |
1873 | p, ins_len, ret == 0); | |
bd681513 | 1874 | btrfs_clear_path_blocking(p, NULL, 0); |
b4ce94de | 1875 | |
33c66f43 YZ |
1876 | BUG_ON(err > 0); |
1877 | if (err) { | |
1878 | ret = err; | |
65b51a00 CM |
1879 | goto done; |
1880 | } | |
5c680ed6 | 1881 | } |
459931ec | 1882 | if (!p->search_for_split) |
f7c79f30 CM |
1883 | unlock_up(p, level, lowest_unlock, |
1884 | min_write_lock_level, &write_lock_level); | |
65b51a00 | 1885 | goto done; |
be0e5c09 CM |
1886 | } |
1887 | } | |
65b51a00 CM |
1888 | ret = 1; |
1889 | done: | |
b4ce94de CM |
1890 | /* |
1891 | * we don't really know what they plan on doing with the path | |
1892 | * from here on, so for now just mark it as blocking | |
1893 | */ | |
b9473439 CM |
1894 | if (!p->leave_spinning) |
1895 | btrfs_set_path_blocking(p); | |
76a05b35 | 1896 | if (ret < 0) |
b3b4aa74 | 1897 | btrfs_release_path(p); |
65b51a00 | 1898 | return ret; |
be0e5c09 CM |
1899 | } |
1900 | ||
74123bd7 CM |
1901 | /* |
1902 | * adjust the pointers going up the tree, starting at level | |
1903 | * making sure the right key of each node is points to 'key'. | |
1904 | * This is used after shifting pointers to the left, so it stops | |
1905 | * fixing up pointers when a given leaf/node is not in slot 0 of the | |
1906 | * higher levels | |
aa5d6bed CM |
1907 | * |
1908 | * If this fails to write a tree block, it returns -1, but continues | |
1909 | * fixing up the blocks in ram so the tree is consistent. | |
74123bd7 | 1910 | */ |
5f39d397 CM |
1911 | static int fixup_low_keys(struct btrfs_trans_handle *trans, |
1912 | struct btrfs_root *root, struct btrfs_path *path, | |
1913 | struct btrfs_disk_key *key, int level) | |
be0e5c09 CM |
1914 | { |
1915 | int i; | |
aa5d6bed | 1916 | int ret = 0; |
5f39d397 CM |
1917 | struct extent_buffer *t; |
1918 | ||
234b63a0 | 1919 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { |
be0e5c09 | 1920 | int tslot = path->slots[i]; |
eb60ceac | 1921 | if (!path->nodes[i]) |
be0e5c09 | 1922 | break; |
5f39d397 CM |
1923 | t = path->nodes[i]; |
1924 | btrfs_set_node_key(t, key, tslot); | |
d6025579 | 1925 | btrfs_mark_buffer_dirty(path->nodes[i]); |
be0e5c09 CM |
1926 | if (tslot != 0) |
1927 | break; | |
1928 | } | |
aa5d6bed | 1929 | return ret; |
be0e5c09 CM |
1930 | } |
1931 | ||
31840ae1 ZY |
1932 | /* |
1933 | * update item key. | |
1934 | * | |
1935 | * This function isn't completely safe. It's the caller's responsibility | |
1936 | * that the new key won't break the order | |
1937 | */ | |
1938 | int btrfs_set_item_key_safe(struct btrfs_trans_handle *trans, | |
1939 | struct btrfs_root *root, struct btrfs_path *path, | |
1940 | struct btrfs_key *new_key) | |
1941 | { | |
1942 | struct btrfs_disk_key disk_key; | |
1943 | struct extent_buffer *eb; | |
1944 | int slot; | |
1945 | ||
1946 | eb = path->nodes[0]; | |
1947 | slot = path->slots[0]; | |
1948 | if (slot > 0) { | |
1949 | btrfs_item_key(eb, &disk_key, slot - 1); | |
1950 | if (comp_keys(&disk_key, new_key) >= 0) | |
1951 | return -1; | |
1952 | } | |
1953 | if (slot < btrfs_header_nritems(eb) - 1) { | |
1954 | btrfs_item_key(eb, &disk_key, slot + 1); | |
1955 | if (comp_keys(&disk_key, new_key) <= 0) | |
1956 | return -1; | |
1957 | } | |
1958 | ||
1959 | btrfs_cpu_key_to_disk(&disk_key, new_key); | |
1960 | btrfs_set_item_key(eb, &disk_key, slot); | |
1961 | btrfs_mark_buffer_dirty(eb); | |
1962 | if (slot == 0) | |
1963 | fixup_low_keys(trans, root, path, &disk_key, 1); | |
1964 | return 0; | |
1965 | } | |
1966 | ||
74123bd7 CM |
1967 | /* |
1968 | * try to push data from one node into the next node left in the | |
79f95c82 | 1969 | * tree. |
aa5d6bed CM |
1970 | * |
1971 | * returns 0 if some ptrs were pushed left, < 0 if there was some horrible | |
1972 | * error, and > 0 if there was no room in the left hand block. | |
74123bd7 | 1973 | */ |
98ed5174 CM |
1974 | static int push_node_left(struct btrfs_trans_handle *trans, |
1975 | struct btrfs_root *root, struct extent_buffer *dst, | |
971a1f66 | 1976 | struct extent_buffer *src, int empty) |
be0e5c09 | 1977 | { |
be0e5c09 | 1978 | int push_items = 0; |
bb803951 CM |
1979 | int src_nritems; |
1980 | int dst_nritems; | |
aa5d6bed | 1981 | int ret = 0; |
be0e5c09 | 1982 | |
5f39d397 CM |
1983 | src_nritems = btrfs_header_nritems(src); |
1984 | dst_nritems = btrfs_header_nritems(dst); | |
123abc88 | 1985 | push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems; |
7bb86316 CM |
1986 | WARN_ON(btrfs_header_generation(src) != trans->transid); |
1987 | WARN_ON(btrfs_header_generation(dst) != trans->transid); | |
54aa1f4d | 1988 | |
bce4eae9 | 1989 | if (!empty && src_nritems <= 8) |
971a1f66 CM |
1990 | return 1; |
1991 | ||
d397712b | 1992 | if (push_items <= 0) |
be0e5c09 CM |
1993 | return 1; |
1994 | ||
bce4eae9 | 1995 | if (empty) { |
971a1f66 | 1996 | push_items = min(src_nritems, push_items); |
bce4eae9 CM |
1997 | if (push_items < src_nritems) { |
1998 | /* leave at least 8 pointers in the node if | |
1999 | * we aren't going to empty it | |
2000 | */ | |
2001 | if (src_nritems - push_items < 8) { | |
2002 | if (push_items <= 8) | |
2003 | return 1; | |
2004 | push_items -= 8; | |
2005 | } | |
2006 | } | |
2007 | } else | |
2008 | push_items = min(src_nritems - 8, push_items); | |
79f95c82 | 2009 | |
5f39d397 CM |
2010 | copy_extent_buffer(dst, src, |
2011 | btrfs_node_key_ptr_offset(dst_nritems), | |
2012 | btrfs_node_key_ptr_offset(0), | |
d397712b | 2013 | push_items * sizeof(struct btrfs_key_ptr)); |
5f39d397 | 2014 | |
bb803951 | 2015 | if (push_items < src_nritems) { |
5f39d397 CM |
2016 | memmove_extent_buffer(src, btrfs_node_key_ptr_offset(0), |
2017 | btrfs_node_key_ptr_offset(push_items), | |
2018 | (src_nritems - push_items) * | |
2019 | sizeof(struct btrfs_key_ptr)); | |
2020 | } | |
2021 | btrfs_set_header_nritems(src, src_nritems - push_items); | |
2022 | btrfs_set_header_nritems(dst, dst_nritems + push_items); | |
2023 | btrfs_mark_buffer_dirty(src); | |
2024 | btrfs_mark_buffer_dirty(dst); | |
31840ae1 | 2025 | |
79f95c82 CM |
2026 | return ret; |
2027 | } | |
2028 | ||
2029 | /* | |
2030 | * try to push data from one node into the next node right in the | |
2031 | * tree. | |
2032 | * | |
2033 | * returns 0 if some ptrs were pushed, < 0 if there was some horrible | |
2034 | * error, and > 0 if there was no room in the right hand block. | |
2035 | * | |
2036 | * this will only push up to 1/2 the contents of the left node over | |
2037 | */ | |
5f39d397 CM |
2038 | static int balance_node_right(struct btrfs_trans_handle *trans, |
2039 | struct btrfs_root *root, | |
2040 | struct extent_buffer *dst, | |
2041 | struct extent_buffer *src) | |
79f95c82 | 2042 | { |
79f95c82 CM |
2043 | int push_items = 0; |
2044 | int max_push; | |
2045 | int src_nritems; | |
2046 | int dst_nritems; | |
2047 | int ret = 0; | |
79f95c82 | 2048 | |
7bb86316 CM |
2049 | WARN_ON(btrfs_header_generation(src) != trans->transid); |
2050 | WARN_ON(btrfs_header_generation(dst) != trans->transid); | |
2051 | ||
5f39d397 CM |
2052 | src_nritems = btrfs_header_nritems(src); |
2053 | dst_nritems = btrfs_header_nritems(dst); | |
123abc88 | 2054 | push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems; |
d397712b | 2055 | if (push_items <= 0) |
79f95c82 | 2056 | return 1; |
bce4eae9 | 2057 | |
d397712b | 2058 | if (src_nritems < 4) |
bce4eae9 | 2059 | return 1; |
79f95c82 CM |
2060 | |
2061 | max_push = src_nritems / 2 + 1; | |
2062 | /* don't try to empty the node */ | |
d397712b | 2063 | if (max_push >= src_nritems) |
79f95c82 | 2064 | return 1; |
252c38f0 | 2065 | |
79f95c82 CM |
2066 | if (max_push < push_items) |
2067 | push_items = max_push; | |
2068 | ||
5f39d397 CM |
2069 | memmove_extent_buffer(dst, btrfs_node_key_ptr_offset(push_items), |
2070 | btrfs_node_key_ptr_offset(0), | |
2071 | (dst_nritems) * | |
2072 | sizeof(struct btrfs_key_ptr)); | |
d6025579 | 2073 | |
5f39d397 CM |
2074 | copy_extent_buffer(dst, src, |
2075 | btrfs_node_key_ptr_offset(0), | |
2076 | btrfs_node_key_ptr_offset(src_nritems - push_items), | |
d397712b | 2077 | push_items * sizeof(struct btrfs_key_ptr)); |
79f95c82 | 2078 | |
5f39d397 CM |
2079 | btrfs_set_header_nritems(src, src_nritems - push_items); |
2080 | btrfs_set_header_nritems(dst, dst_nritems + push_items); | |
79f95c82 | 2081 | |
5f39d397 CM |
2082 | btrfs_mark_buffer_dirty(src); |
2083 | btrfs_mark_buffer_dirty(dst); | |
31840ae1 | 2084 | |
aa5d6bed | 2085 | return ret; |
be0e5c09 CM |
2086 | } |
2087 | ||
97571fd0 CM |
2088 | /* |
2089 | * helper function to insert a new root level in the tree. | |
2090 | * A new node is allocated, and a single item is inserted to | |
2091 | * point to the existing root | |
aa5d6bed CM |
2092 | * |
2093 | * returns zero on success or < 0 on failure. | |
97571fd0 | 2094 | */ |
d397712b | 2095 | static noinline int insert_new_root(struct btrfs_trans_handle *trans, |
5f39d397 CM |
2096 | struct btrfs_root *root, |
2097 | struct btrfs_path *path, int level) | |
5c680ed6 | 2098 | { |
7bb86316 | 2099 | u64 lower_gen; |
5f39d397 CM |
2100 | struct extent_buffer *lower; |
2101 | struct extent_buffer *c; | |
925baedd | 2102 | struct extent_buffer *old; |
5f39d397 | 2103 | struct btrfs_disk_key lower_key; |
5c680ed6 CM |
2104 | |
2105 | BUG_ON(path->nodes[level]); | |
2106 | BUG_ON(path->nodes[level-1] != root->node); | |
2107 | ||
7bb86316 CM |
2108 | lower = path->nodes[level-1]; |
2109 | if (level == 1) | |
2110 | btrfs_item_key(lower, &lower_key, 0); | |
2111 | else | |
2112 | btrfs_node_key(lower, &lower_key, 0); | |
2113 | ||
31840ae1 | 2114 | c = btrfs_alloc_free_block(trans, root, root->nodesize, 0, |
5d4f98a2 | 2115 | root->root_key.objectid, &lower_key, |
66d7e7f0 | 2116 | level, root->node->start, 0, 0); |
5f39d397 CM |
2117 | if (IS_ERR(c)) |
2118 | return PTR_ERR(c); | |
925baedd | 2119 | |
f0486c68 YZ |
2120 | root_add_used(root, root->nodesize); |
2121 | ||
5d4f98a2 | 2122 | memset_extent_buffer(c, 0, 0, sizeof(struct btrfs_header)); |
5f39d397 CM |
2123 | btrfs_set_header_nritems(c, 1); |
2124 | btrfs_set_header_level(c, level); | |
db94535d | 2125 | btrfs_set_header_bytenr(c, c->start); |
5f39d397 | 2126 | btrfs_set_header_generation(c, trans->transid); |
5d4f98a2 | 2127 | btrfs_set_header_backref_rev(c, BTRFS_MIXED_BACKREF_REV); |
5f39d397 | 2128 | btrfs_set_header_owner(c, root->root_key.objectid); |
5f39d397 CM |
2129 | |
2130 | write_extent_buffer(c, root->fs_info->fsid, | |
2131 | (unsigned long)btrfs_header_fsid(c), | |
2132 | BTRFS_FSID_SIZE); | |
e17cade2 CM |
2133 | |
2134 | write_extent_buffer(c, root->fs_info->chunk_tree_uuid, | |
2135 | (unsigned long)btrfs_header_chunk_tree_uuid(c), | |
2136 | BTRFS_UUID_SIZE); | |
2137 | ||
5f39d397 | 2138 | btrfs_set_node_key(c, &lower_key, 0); |
db94535d | 2139 | btrfs_set_node_blockptr(c, 0, lower->start); |
7bb86316 | 2140 | lower_gen = btrfs_header_generation(lower); |
31840ae1 | 2141 | WARN_ON(lower_gen != trans->transid); |
7bb86316 CM |
2142 | |
2143 | btrfs_set_node_ptr_generation(c, 0, lower_gen); | |
d5719762 | 2144 | |
5f39d397 | 2145 | btrfs_mark_buffer_dirty(c); |
d5719762 | 2146 | |
925baedd | 2147 | old = root->node; |
240f62c8 | 2148 | rcu_assign_pointer(root->node, c); |
925baedd CM |
2149 | |
2150 | /* the super has an extra ref to root->node */ | |
2151 | free_extent_buffer(old); | |
2152 | ||
0b86a832 | 2153 | add_root_to_dirty_list(root); |
5f39d397 CM |
2154 | extent_buffer_get(c); |
2155 | path->nodes[level] = c; | |
bd681513 | 2156 | path->locks[level] = BTRFS_WRITE_LOCK; |
5c680ed6 CM |
2157 | path->slots[level] = 0; |
2158 | return 0; | |
2159 | } | |
2160 | ||
74123bd7 CM |
2161 | /* |
2162 | * worker function to insert a single pointer in a node. | |
2163 | * the node should have enough room for the pointer already | |
97571fd0 | 2164 | * |
74123bd7 CM |
2165 | * slot and level indicate where you want the key to go, and |
2166 | * blocknr is the block the key points to. | |
aa5d6bed CM |
2167 | * |
2168 | * returns zero on success and < 0 on any error | |
74123bd7 | 2169 | */ |
e089f05c CM |
2170 | static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root |
2171 | *root, struct btrfs_path *path, struct btrfs_disk_key | |
db94535d | 2172 | *key, u64 bytenr, int slot, int level) |
74123bd7 | 2173 | { |
5f39d397 | 2174 | struct extent_buffer *lower; |
74123bd7 | 2175 | int nritems; |
5c680ed6 CM |
2176 | |
2177 | BUG_ON(!path->nodes[level]); | |
f0486c68 | 2178 | btrfs_assert_tree_locked(path->nodes[level]); |
5f39d397 CM |
2179 | lower = path->nodes[level]; |
2180 | nritems = btrfs_header_nritems(lower); | |
c293498b | 2181 | BUG_ON(slot > nritems); |
123abc88 | 2182 | if (nritems == BTRFS_NODEPTRS_PER_BLOCK(root)) |
74123bd7 CM |
2183 | BUG(); |
2184 | if (slot != nritems) { | |
5f39d397 CM |
2185 | memmove_extent_buffer(lower, |
2186 | btrfs_node_key_ptr_offset(slot + 1), | |
2187 | btrfs_node_key_ptr_offset(slot), | |
d6025579 | 2188 | (nritems - slot) * sizeof(struct btrfs_key_ptr)); |
74123bd7 | 2189 | } |
5f39d397 | 2190 | btrfs_set_node_key(lower, key, slot); |
db94535d | 2191 | btrfs_set_node_blockptr(lower, slot, bytenr); |
74493f7a CM |
2192 | WARN_ON(trans->transid == 0); |
2193 | btrfs_set_node_ptr_generation(lower, slot, trans->transid); | |
5f39d397 CM |
2194 | btrfs_set_header_nritems(lower, nritems + 1); |
2195 | btrfs_mark_buffer_dirty(lower); | |
74123bd7 CM |
2196 | return 0; |
2197 | } | |
2198 | ||
97571fd0 CM |
2199 | /* |
2200 | * split the node at the specified level in path in two. | |
2201 | * The path is corrected to point to the appropriate node after the split | |
2202 | * | |
2203 | * Before splitting this tries to make some room in the node by pushing | |
2204 | * left and right, if either one works, it returns right away. | |
aa5d6bed CM |
2205 | * |
2206 | * returns 0 on success and < 0 on failure | |
97571fd0 | 2207 | */ |
e02119d5 CM |
2208 | static noinline int split_node(struct btrfs_trans_handle *trans, |
2209 | struct btrfs_root *root, | |
2210 | struct btrfs_path *path, int level) | |
be0e5c09 | 2211 | { |
5f39d397 CM |
2212 | struct extent_buffer *c; |
2213 | struct extent_buffer *split; | |
2214 | struct btrfs_disk_key disk_key; | |
be0e5c09 | 2215 | int mid; |
5c680ed6 | 2216 | int ret; |
aa5d6bed | 2217 | int wret; |
7518a238 | 2218 | u32 c_nritems; |
eb60ceac | 2219 | |
5f39d397 | 2220 | c = path->nodes[level]; |
7bb86316 | 2221 | WARN_ON(btrfs_header_generation(c) != trans->transid); |
5f39d397 | 2222 | if (c == root->node) { |
5c680ed6 | 2223 | /* trying to split the root, lets make a new one */ |
e089f05c | 2224 | ret = insert_new_root(trans, root, path, level + 1); |
5c680ed6 CM |
2225 | if (ret) |
2226 | return ret; | |
b3612421 | 2227 | } else { |
e66f709b | 2228 | ret = push_nodes_for_insert(trans, root, path, level); |
5f39d397 CM |
2229 | c = path->nodes[level]; |
2230 | if (!ret && btrfs_header_nritems(c) < | |
c448acf0 | 2231 | BTRFS_NODEPTRS_PER_BLOCK(root) - 3) |
e66f709b | 2232 | return 0; |
54aa1f4d CM |
2233 | if (ret < 0) |
2234 | return ret; | |
be0e5c09 | 2235 | } |
e66f709b | 2236 | |
5f39d397 | 2237 | c_nritems = btrfs_header_nritems(c); |
5d4f98a2 YZ |
2238 | mid = (c_nritems + 1) / 2; |
2239 | btrfs_node_key(c, &disk_key, mid); | |
7bb86316 | 2240 | |
5d4f98a2 | 2241 | split = btrfs_alloc_free_block(trans, root, root->nodesize, 0, |
31840ae1 | 2242 | root->root_key.objectid, |
66d7e7f0 | 2243 | &disk_key, level, c->start, 0, 0); |
5f39d397 CM |
2244 | if (IS_ERR(split)) |
2245 | return PTR_ERR(split); | |
2246 | ||
f0486c68 YZ |
2247 | root_add_used(root, root->nodesize); |
2248 | ||
5d4f98a2 | 2249 | memset_extent_buffer(split, 0, 0, sizeof(struct btrfs_header)); |
5f39d397 | 2250 | btrfs_set_header_level(split, btrfs_header_level(c)); |
db94535d | 2251 | btrfs_set_header_bytenr(split, split->start); |
5f39d397 | 2252 | btrfs_set_header_generation(split, trans->transid); |
5d4f98a2 | 2253 | btrfs_set_header_backref_rev(split, BTRFS_MIXED_BACKREF_REV); |
5f39d397 CM |
2254 | btrfs_set_header_owner(split, root->root_key.objectid); |
2255 | write_extent_buffer(split, root->fs_info->fsid, | |
2256 | (unsigned long)btrfs_header_fsid(split), | |
2257 | BTRFS_FSID_SIZE); | |
e17cade2 CM |
2258 | write_extent_buffer(split, root->fs_info->chunk_tree_uuid, |
2259 | (unsigned long)btrfs_header_chunk_tree_uuid(split), | |
2260 | BTRFS_UUID_SIZE); | |
54aa1f4d | 2261 | |
5f39d397 CM |
2262 | |
2263 | copy_extent_buffer(split, c, | |
2264 | btrfs_node_key_ptr_offset(0), | |
2265 | btrfs_node_key_ptr_offset(mid), | |
2266 | (c_nritems - mid) * sizeof(struct btrfs_key_ptr)); | |
2267 | btrfs_set_header_nritems(split, c_nritems - mid); | |
2268 | btrfs_set_header_nritems(c, mid); | |
aa5d6bed CM |
2269 | ret = 0; |
2270 | ||
5f39d397 CM |
2271 | btrfs_mark_buffer_dirty(c); |
2272 | btrfs_mark_buffer_dirty(split); | |
2273 | ||
db94535d | 2274 | wret = insert_ptr(trans, root, path, &disk_key, split->start, |
5f39d397 | 2275 | path->slots[level + 1] + 1, |
123abc88 | 2276 | level + 1); |
aa5d6bed CM |
2277 | if (wret) |
2278 | ret = wret; | |
2279 | ||
5de08d7d | 2280 | if (path->slots[level] >= mid) { |
5c680ed6 | 2281 | path->slots[level] -= mid; |
925baedd | 2282 | btrfs_tree_unlock(c); |
5f39d397 CM |
2283 | free_extent_buffer(c); |
2284 | path->nodes[level] = split; | |
5c680ed6 CM |
2285 | path->slots[level + 1] += 1; |
2286 | } else { | |
925baedd | 2287 | btrfs_tree_unlock(split); |
5f39d397 | 2288 | free_extent_buffer(split); |
be0e5c09 | 2289 | } |
aa5d6bed | 2290 | return ret; |
be0e5c09 CM |
2291 | } |
2292 | ||
74123bd7 CM |
2293 | /* |
2294 | * how many bytes are required to store the items in a leaf. start | |
2295 | * and nr indicate which items in the leaf to check. This totals up the | |
2296 | * space used both by the item structs and the item data | |
2297 | */ | |
5f39d397 | 2298 | static int leaf_space_used(struct extent_buffer *l, int start, int nr) |
be0e5c09 CM |
2299 | { |
2300 | int data_len; | |
5f39d397 | 2301 | int nritems = btrfs_header_nritems(l); |
d4dbff95 | 2302 | int end = min(nritems, start + nr) - 1; |
be0e5c09 CM |
2303 | |
2304 | if (!nr) | |
2305 | return 0; | |
5f39d397 CM |
2306 | data_len = btrfs_item_end_nr(l, start); |
2307 | data_len = data_len - btrfs_item_offset_nr(l, end); | |
0783fcfc | 2308 | data_len += sizeof(struct btrfs_item) * nr; |
d4dbff95 | 2309 | WARN_ON(data_len < 0); |
be0e5c09 CM |
2310 | return data_len; |
2311 | } | |
2312 | ||
d4dbff95 CM |
2313 | /* |
2314 | * The space between the end of the leaf items and | |
2315 | * the start of the leaf data. IOW, how much room | |
2316 | * the leaf has left for both items and data | |
2317 | */ | |
d397712b | 2318 | noinline int btrfs_leaf_free_space(struct btrfs_root *root, |
e02119d5 | 2319 | struct extent_buffer *leaf) |
d4dbff95 | 2320 | { |
5f39d397 CM |
2321 | int nritems = btrfs_header_nritems(leaf); |
2322 | int ret; | |
2323 | ret = BTRFS_LEAF_DATA_SIZE(root) - leaf_space_used(leaf, 0, nritems); | |
2324 | if (ret < 0) { | |
d397712b CM |
2325 | printk(KERN_CRIT "leaf free space ret %d, leaf data size %lu, " |
2326 | "used %d nritems %d\n", | |
ae2f5411 | 2327 | ret, (unsigned long) BTRFS_LEAF_DATA_SIZE(root), |
5f39d397 CM |
2328 | leaf_space_used(leaf, 0, nritems), nritems); |
2329 | } | |
2330 | return ret; | |
d4dbff95 CM |
2331 | } |
2332 | ||
99d8f83c CM |
2333 | /* |
2334 | * min slot controls the lowest index we're willing to push to the | |
2335 | * right. We'll push up to and including min_slot, but no lower | |
2336 | */ | |
44871b1b CM |
2337 | static noinline int __push_leaf_right(struct btrfs_trans_handle *trans, |
2338 | struct btrfs_root *root, | |
2339 | struct btrfs_path *path, | |
2340 | int data_size, int empty, | |
2341 | struct extent_buffer *right, | |
99d8f83c CM |
2342 | int free_space, u32 left_nritems, |
2343 | u32 min_slot) | |
00ec4c51 | 2344 | { |
5f39d397 | 2345 | struct extent_buffer *left = path->nodes[0]; |
44871b1b | 2346 | struct extent_buffer *upper = path->nodes[1]; |
cfed81a0 | 2347 | struct btrfs_map_token token; |
5f39d397 | 2348 | struct btrfs_disk_key disk_key; |
00ec4c51 | 2349 | int slot; |
34a38218 | 2350 | u32 i; |
00ec4c51 CM |
2351 | int push_space = 0; |
2352 | int push_items = 0; | |
0783fcfc | 2353 | struct btrfs_item *item; |
34a38218 | 2354 | u32 nr; |
7518a238 | 2355 | u32 right_nritems; |
5f39d397 | 2356 | u32 data_end; |
db94535d | 2357 | u32 this_item_size; |
00ec4c51 | 2358 | |
cfed81a0 CM |
2359 | btrfs_init_map_token(&token); |
2360 | ||
34a38218 CM |
2361 | if (empty) |
2362 | nr = 0; | |
2363 | else | |
99d8f83c | 2364 | nr = max_t(u32, 1, min_slot); |
34a38218 | 2365 | |
31840ae1 | 2366 | if (path->slots[0] >= left_nritems) |
87b29b20 | 2367 | push_space += data_size; |
31840ae1 | 2368 | |
44871b1b | 2369 | slot = path->slots[1]; |
34a38218 CM |
2370 | i = left_nritems - 1; |
2371 | while (i >= nr) { | |
5f39d397 | 2372 | item = btrfs_item_nr(left, i); |
db94535d | 2373 | |
31840ae1 ZY |
2374 | if (!empty && push_items > 0) { |
2375 | if (path->slots[0] > i) | |
2376 | break; | |
2377 | if (path->slots[0] == i) { | |
2378 | int space = btrfs_leaf_free_space(root, left); | |
2379 | if (space + push_space * 2 > free_space) | |
2380 | break; | |
2381 | } | |
2382 | } | |
2383 | ||
00ec4c51 | 2384 | if (path->slots[0] == i) |
87b29b20 | 2385 | push_space += data_size; |
db94535d | 2386 | |
db94535d CM |
2387 | this_item_size = btrfs_item_size(left, item); |
2388 | if (this_item_size + sizeof(*item) + push_space > free_space) | |
00ec4c51 | 2389 | break; |
31840ae1 | 2390 | |
00ec4c51 | 2391 | push_items++; |
db94535d | 2392 | push_space += this_item_size + sizeof(*item); |
34a38218 CM |
2393 | if (i == 0) |
2394 | break; | |
2395 | i--; | |
db94535d | 2396 | } |
5f39d397 | 2397 | |
925baedd CM |
2398 | if (push_items == 0) |
2399 | goto out_unlock; | |
5f39d397 | 2400 | |
34a38218 | 2401 | if (!empty && push_items == left_nritems) |
a429e513 | 2402 | WARN_ON(1); |
5f39d397 | 2403 | |
00ec4c51 | 2404 | /* push left to right */ |
5f39d397 | 2405 | right_nritems = btrfs_header_nritems(right); |
34a38218 | 2406 | |
5f39d397 | 2407 | push_space = btrfs_item_end_nr(left, left_nritems - push_items); |
123abc88 | 2408 | push_space -= leaf_data_end(root, left); |
5f39d397 | 2409 | |
00ec4c51 | 2410 | /* make room in the right data area */ |
5f39d397 CM |
2411 | data_end = leaf_data_end(root, right); |
2412 | memmove_extent_buffer(right, | |
2413 | btrfs_leaf_data(right) + data_end - push_space, | |
2414 | btrfs_leaf_data(right) + data_end, | |
2415 | BTRFS_LEAF_DATA_SIZE(root) - data_end); | |
2416 | ||
00ec4c51 | 2417 | /* copy from the left data area */ |
5f39d397 | 2418 | copy_extent_buffer(right, left, btrfs_leaf_data(right) + |
d6025579 CM |
2419 | BTRFS_LEAF_DATA_SIZE(root) - push_space, |
2420 | btrfs_leaf_data(left) + leaf_data_end(root, left), | |
2421 | push_space); | |
5f39d397 CM |
2422 | |
2423 | memmove_extent_buffer(right, btrfs_item_nr_offset(push_items), | |
2424 | btrfs_item_nr_offset(0), | |
2425 | right_nritems * sizeof(struct btrfs_item)); | |
2426 | ||
00ec4c51 | 2427 | /* copy the items from left to right */ |
5f39d397 CM |
2428 | copy_extent_buffer(right, left, btrfs_item_nr_offset(0), |
2429 | btrfs_item_nr_offset(left_nritems - push_items), | |
2430 | push_items * sizeof(struct btrfs_item)); | |
00ec4c51 CM |
2431 | |
2432 | /* update the item pointers */ | |
7518a238 | 2433 | right_nritems += push_items; |
5f39d397 | 2434 | btrfs_set_header_nritems(right, right_nritems); |
123abc88 | 2435 | push_space = BTRFS_LEAF_DATA_SIZE(root); |
7518a238 | 2436 | for (i = 0; i < right_nritems; i++) { |
5f39d397 | 2437 | item = btrfs_item_nr(right, i); |
cfed81a0 CM |
2438 | push_space -= btrfs_token_item_size(right, item, &token); |
2439 | btrfs_set_token_item_offset(right, item, push_space, &token); | |
db94535d CM |
2440 | } |
2441 | ||
7518a238 | 2442 | left_nritems -= push_items; |
5f39d397 | 2443 | btrfs_set_header_nritems(left, left_nritems); |
00ec4c51 | 2444 | |
34a38218 CM |
2445 | if (left_nritems) |
2446 | btrfs_mark_buffer_dirty(left); | |
f0486c68 YZ |
2447 | else |
2448 | clean_tree_block(trans, root, left); | |
2449 | ||
5f39d397 | 2450 | btrfs_mark_buffer_dirty(right); |
a429e513 | 2451 | |
5f39d397 CM |
2452 | btrfs_item_key(right, &disk_key, 0); |
2453 | btrfs_set_node_key(upper, &disk_key, slot + 1); | |
d6025579 | 2454 | btrfs_mark_buffer_dirty(upper); |
02217ed2 | 2455 | |
00ec4c51 | 2456 | /* then fixup the leaf pointer in the path */ |
7518a238 CM |
2457 | if (path->slots[0] >= left_nritems) { |
2458 | path->slots[0] -= left_nritems; | |
925baedd CM |
2459 | if (btrfs_header_nritems(path->nodes[0]) == 0) |
2460 | clean_tree_block(trans, root, path->nodes[0]); | |
2461 | btrfs_tree_unlock(path->nodes[0]); | |
5f39d397 CM |
2462 | free_extent_buffer(path->nodes[0]); |
2463 | path->nodes[0] = right; | |
00ec4c51 CM |
2464 | path->slots[1] += 1; |
2465 | } else { | |
925baedd | 2466 | btrfs_tree_unlock(right); |
5f39d397 | 2467 | free_extent_buffer(right); |
00ec4c51 CM |
2468 | } |
2469 | return 0; | |
925baedd CM |
2470 | |
2471 | out_unlock: | |
2472 | btrfs_tree_unlock(right); | |
2473 | free_extent_buffer(right); | |
2474 | return 1; | |
00ec4c51 | 2475 | } |
925baedd | 2476 | |
44871b1b CM |
2477 | /* |
2478 | * push some data in the path leaf to the right, trying to free up at | |
2479 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
2480 | * | |
2481 | * returns 1 if the push failed because the other node didn't have enough | |
2482 | * room, 0 if everything worked out and < 0 if there were major errors. | |
99d8f83c CM |
2483 | * |
2484 | * this will push starting from min_slot to the end of the leaf. It won't | |
2485 | * push any slot lower than min_slot | |
44871b1b CM |
2486 | */ |
2487 | static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root | |
99d8f83c CM |
2488 | *root, struct btrfs_path *path, |
2489 | int min_data_size, int data_size, | |
2490 | int empty, u32 min_slot) | |
44871b1b CM |
2491 | { |
2492 | struct extent_buffer *left = path->nodes[0]; | |
2493 | struct extent_buffer *right; | |
2494 | struct extent_buffer *upper; | |
2495 | int slot; | |
2496 | int free_space; | |
2497 | u32 left_nritems; | |
2498 | int ret; | |
2499 | ||
2500 | if (!path->nodes[1]) | |
2501 | return 1; | |
2502 | ||
2503 | slot = path->slots[1]; | |
2504 | upper = path->nodes[1]; | |
2505 | if (slot >= btrfs_header_nritems(upper) - 1) | |
2506 | return 1; | |
2507 | ||
2508 | btrfs_assert_tree_locked(path->nodes[1]); | |
2509 | ||
2510 | right = read_node_slot(root, upper, slot + 1); | |
91ca338d TI |
2511 | if (right == NULL) |
2512 | return 1; | |
2513 | ||
44871b1b CM |
2514 | btrfs_tree_lock(right); |
2515 | btrfs_set_lock_blocking(right); | |
2516 | ||
2517 | free_space = btrfs_leaf_free_space(root, right); | |
2518 | if (free_space < data_size) | |
2519 | goto out_unlock; | |
2520 | ||
2521 | /* cow and double check */ | |
2522 | ret = btrfs_cow_block(trans, root, right, upper, | |
2523 | slot + 1, &right); | |
2524 | if (ret) | |
2525 | goto out_unlock; | |
2526 | ||
2527 | free_space = btrfs_leaf_free_space(root, right); | |
2528 | if (free_space < data_size) | |
2529 | goto out_unlock; | |
2530 | ||
2531 | left_nritems = btrfs_header_nritems(left); | |
2532 | if (left_nritems == 0) | |
2533 | goto out_unlock; | |
2534 | ||
99d8f83c CM |
2535 | return __push_leaf_right(trans, root, path, min_data_size, empty, |
2536 | right, free_space, left_nritems, min_slot); | |
44871b1b CM |
2537 | out_unlock: |
2538 | btrfs_tree_unlock(right); | |
2539 | free_extent_buffer(right); | |
2540 | return 1; | |
2541 | } | |
2542 | ||
74123bd7 CM |
2543 | /* |
2544 | * push some data in the path leaf to the left, trying to free up at | |
2545 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
99d8f83c CM |
2546 | * |
2547 | * max_slot can put a limit on how far into the leaf we'll push items. The | |
2548 | * item at 'max_slot' won't be touched. Use (u32)-1 to make us do all the | |
2549 | * items | |
74123bd7 | 2550 | */ |
44871b1b CM |
2551 | static noinline int __push_leaf_left(struct btrfs_trans_handle *trans, |
2552 | struct btrfs_root *root, | |
2553 | struct btrfs_path *path, int data_size, | |
2554 | int empty, struct extent_buffer *left, | |
99d8f83c CM |
2555 | int free_space, u32 right_nritems, |
2556 | u32 max_slot) | |
be0e5c09 | 2557 | { |
5f39d397 CM |
2558 | struct btrfs_disk_key disk_key; |
2559 | struct extent_buffer *right = path->nodes[0]; | |
be0e5c09 | 2560 | int i; |
be0e5c09 CM |
2561 | int push_space = 0; |
2562 | int push_items = 0; | |
0783fcfc | 2563 | struct btrfs_item *item; |
7518a238 | 2564 | u32 old_left_nritems; |
34a38218 | 2565 | u32 nr; |
aa5d6bed CM |
2566 | int ret = 0; |
2567 | int wret; | |
db94535d CM |
2568 | u32 this_item_size; |
2569 | u32 old_left_item_size; | |
cfed81a0 CM |
2570 | struct btrfs_map_token token; |
2571 | ||
2572 | btrfs_init_map_token(&token); | |
be0e5c09 | 2573 | |
34a38218 | 2574 | if (empty) |
99d8f83c | 2575 | nr = min(right_nritems, max_slot); |
34a38218 | 2576 | else |
99d8f83c | 2577 | nr = min(right_nritems - 1, max_slot); |
34a38218 CM |
2578 | |
2579 | for (i = 0; i < nr; i++) { | |
5f39d397 | 2580 | item = btrfs_item_nr(right, i); |
db94535d | 2581 | |
31840ae1 ZY |
2582 | if (!empty && push_items > 0) { |
2583 | if (path->slots[0] < i) | |
2584 | break; | |
2585 | if (path->slots[0] == i) { | |
2586 | int space = btrfs_leaf_free_space(root, right); | |
2587 | if (space + push_space * 2 > free_space) | |
2588 | break; | |
2589 | } | |
2590 | } | |
2591 | ||
be0e5c09 | 2592 | if (path->slots[0] == i) |
87b29b20 | 2593 | push_space += data_size; |
db94535d CM |
2594 | |
2595 | this_item_size = btrfs_item_size(right, item); | |
2596 | if (this_item_size + sizeof(*item) + push_space > free_space) | |
be0e5c09 | 2597 | break; |
db94535d | 2598 | |
be0e5c09 | 2599 | push_items++; |
db94535d CM |
2600 | push_space += this_item_size + sizeof(*item); |
2601 | } | |
2602 | ||
be0e5c09 | 2603 | if (push_items == 0) { |
925baedd CM |
2604 | ret = 1; |
2605 | goto out; | |
be0e5c09 | 2606 | } |
34a38218 | 2607 | if (!empty && push_items == btrfs_header_nritems(right)) |
a429e513 | 2608 | WARN_ON(1); |
5f39d397 | 2609 | |
be0e5c09 | 2610 | /* push data from right to left */ |
5f39d397 CM |
2611 | copy_extent_buffer(left, right, |
2612 | btrfs_item_nr_offset(btrfs_header_nritems(left)), | |
2613 | btrfs_item_nr_offset(0), | |
2614 | push_items * sizeof(struct btrfs_item)); | |
2615 | ||
123abc88 | 2616 | push_space = BTRFS_LEAF_DATA_SIZE(root) - |
d397712b | 2617 | btrfs_item_offset_nr(right, push_items - 1); |
5f39d397 CM |
2618 | |
2619 | copy_extent_buffer(left, right, btrfs_leaf_data(left) + | |
d6025579 CM |
2620 | leaf_data_end(root, left) - push_space, |
2621 | btrfs_leaf_data(right) + | |
5f39d397 | 2622 | btrfs_item_offset_nr(right, push_items - 1), |
d6025579 | 2623 | push_space); |
5f39d397 | 2624 | old_left_nritems = btrfs_header_nritems(left); |
87b29b20 | 2625 | BUG_ON(old_left_nritems <= 0); |
eb60ceac | 2626 | |
db94535d | 2627 | old_left_item_size = btrfs_item_offset_nr(left, old_left_nritems - 1); |
0783fcfc | 2628 | for (i = old_left_nritems; i < old_left_nritems + push_items; i++) { |
5f39d397 | 2629 | u32 ioff; |
db94535d | 2630 | |
5f39d397 | 2631 | item = btrfs_item_nr(left, i); |
db94535d | 2632 | |
cfed81a0 CM |
2633 | ioff = btrfs_token_item_offset(left, item, &token); |
2634 | btrfs_set_token_item_offset(left, item, | |
2635 | ioff - (BTRFS_LEAF_DATA_SIZE(root) - old_left_item_size), | |
2636 | &token); | |
be0e5c09 | 2637 | } |
5f39d397 | 2638 | btrfs_set_header_nritems(left, old_left_nritems + push_items); |
be0e5c09 CM |
2639 | |
2640 | /* fixup right node */ | |
34a38218 | 2641 | if (push_items > right_nritems) { |
d397712b CM |
2642 | printk(KERN_CRIT "push items %d nr %u\n", push_items, |
2643 | right_nritems); | |
34a38218 CM |
2644 | WARN_ON(1); |
2645 | } | |
2646 | ||
2647 | if (push_items < right_nritems) { | |
2648 | push_space = btrfs_item_offset_nr(right, push_items - 1) - | |
2649 | leaf_data_end(root, right); | |
2650 | memmove_extent_buffer(right, btrfs_leaf_data(right) + | |
2651 | BTRFS_LEAF_DATA_SIZE(root) - push_space, | |
2652 | btrfs_leaf_data(right) + | |
2653 | leaf_data_end(root, right), push_space); | |
2654 | ||
2655 | memmove_extent_buffer(right, btrfs_item_nr_offset(0), | |
5f39d397 CM |
2656 | btrfs_item_nr_offset(push_items), |
2657 | (btrfs_header_nritems(right) - push_items) * | |
2658 | sizeof(struct btrfs_item)); | |
34a38218 | 2659 | } |
eef1c494 Y |
2660 | right_nritems -= push_items; |
2661 | btrfs_set_header_nritems(right, right_nritems); | |
123abc88 | 2662 | push_space = BTRFS_LEAF_DATA_SIZE(root); |
5f39d397 CM |
2663 | for (i = 0; i < right_nritems; i++) { |
2664 | item = btrfs_item_nr(right, i); | |
db94535d | 2665 | |
cfed81a0 CM |
2666 | push_space = push_space - btrfs_token_item_size(right, |
2667 | item, &token); | |
2668 | btrfs_set_token_item_offset(right, item, push_space, &token); | |
db94535d | 2669 | } |
eb60ceac | 2670 | |
5f39d397 | 2671 | btrfs_mark_buffer_dirty(left); |
34a38218 CM |
2672 | if (right_nritems) |
2673 | btrfs_mark_buffer_dirty(right); | |
f0486c68 YZ |
2674 | else |
2675 | clean_tree_block(trans, root, right); | |
098f59c2 | 2676 | |
5f39d397 CM |
2677 | btrfs_item_key(right, &disk_key, 0); |
2678 | wret = fixup_low_keys(trans, root, path, &disk_key, 1); | |
aa5d6bed CM |
2679 | if (wret) |
2680 | ret = wret; | |
be0e5c09 CM |
2681 | |
2682 | /* then fixup the leaf pointer in the path */ | |
2683 | if (path->slots[0] < push_items) { | |
2684 | path->slots[0] += old_left_nritems; | |
925baedd | 2685 | btrfs_tree_unlock(path->nodes[0]); |
5f39d397 CM |
2686 | free_extent_buffer(path->nodes[0]); |
2687 | path->nodes[0] = left; | |
be0e5c09 CM |
2688 | path->slots[1] -= 1; |
2689 | } else { | |
925baedd | 2690 | btrfs_tree_unlock(left); |
5f39d397 | 2691 | free_extent_buffer(left); |
be0e5c09 CM |
2692 | path->slots[0] -= push_items; |
2693 | } | |
eb60ceac | 2694 | BUG_ON(path->slots[0] < 0); |
aa5d6bed | 2695 | return ret; |
925baedd CM |
2696 | out: |
2697 | btrfs_tree_unlock(left); | |
2698 | free_extent_buffer(left); | |
2699 | return ret; | |
be0e5c09 CM |
2700 | } |
2701 | ||
44871b1b CM |
2702 | /* |
2703 | * push some data in the path leaf to the left, trying to free up at | |
2704 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
99d8f83c CM |
2705 | * |
2706 | * max_slot can put a limit on how far into the leaf we'll push items. The | |
2707 | * item at 'max_slot' won't be touched. Use (u32)-1 to make us push all the | |
2708 | * items | |
44871b1b CM |
2709 | */ |
2710 | static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root | |
99d8f83c CM |
2711 | *root, struct btrfs_path *path, int min_data_size, |
2712 | int data_size, int empty, u32 max_slot) | |
44871b1b CM |
2713 | { |
2714 | struct extent_buffer *right = path->nodes[0]; | |
2715 | struct extent_buffer *left; | |
2716 | int slot; | |
2717 | int free_space; | |
2718 | u32 right_nritems; | |
2719 | int ret = 0; | |
2720 | ||
2721 | slot = path->slots[1]; | |
2722 | if (slot == 0) | |
2723 | return 1; | |
2724 | if (!path->nodes[1]) | |
2725 | return 1; | |
2726 | ||
2727 | right_nritems = btrfs_header_nritems(right); | |
2728 | if (right_nritems == 0) | |
2729 | return 1; | |
2730 | ||
2731 | btrfs_assert_tree_locked(path->nodes[1]); | |
2732 | ||
2733 | left = read_node_slot(root, path->nodes[1], slot - 1); | |
91ca338d TI |
2734 | if (left == NULL) |
2735 | return 1; | |
2736 | ||
44871b1b CM |
2737 | btrfs_tree_lock(left); |
2738 | btrfs_set_lock_blocking(left); | |
2739 | ||
2740 | free_space = btrfs_leaf_free_space(root, left); | |
2741 | if (free_space < data_size) { | |
2742 | ret = 1; | |
2743 | goto out; | |
2744 | } | |
2745 | ||
2746 | /* cow and double check */ | |
2747 | ret = btrfs_cow_block(trans, root, left, | |
2748 | path->nodes[1], slot - 1, &left); | |
2749 | if (ret) { | |
2750 | /* we hit -ENOSPC, but it isn't fatal here */ | |
2751 | ret = 1; | |
2752 | goto out; | |
2753 | } | |
2754 | ||
2755 | free_space = btrfs_leaf_free_space(root, left); | |
2756 | if (free_space < data_size) { | |
2757 | ret = 1; | |
2758 | goto out; | |
2759 | } | |
2760 | ||
99d8f83c CM |
2761 | return __push_leaf_left(trans, root, path, min_data_size, |
2762 | empty, left, free_space, right_nritems, | |
2763 | max_slot); | |
44871b1b CM |
2764 | out: |
2765 | btrfs_tree_unlock(left); | |
2766 | free_extent_buffer(left); | |
2767 | return ret; | |
2768 | } | |
2769 | ||
2770 | /* | |
2771 | * split the path's leaf in two, making sure there is at least data_size | |
2772 | * available for the resulting leaf level of the path. | |
2773 | * | |
2774 | * returns 0 if all went well and < 0 on failure. | |
2775 | */ | |
2776 | static noinline int copy_for_split(struct btrfs_trans_handle *trans, | |
2777 | struct btrfs_root *root, | |
2778 | struct btrfs_path *path, | |
2779 | struct extent_buffer *l, | |
2780 | struct extent_buffer *right, | |
2781 | int slot, int mid, int nritems) | |
2782 | { | |
2783 | int data_copy_size; | |
2784 | int rt_data_off; | |
2785 | int i; | |
2786 | int ret = 0; | |
2787 | int wret; | |
2788 | struct btrfs_disk_key disk_key; | |
cfed81a0 CM |
2789 | struct btrfs_map_token token; |
2790 | ||
2791 | btrfs_init_map_token(&token); | |
44871b1b CM |
2792 | |
2793 | nritems = nritems - mid; | |
2794 | btrfs_set_header_nritems(right, nritems); | |
2795 | data_copy_size = btrfs_item_end_nr(l, mid) - leaf_data_end(root, l); | |
2796 | ||
2797 | copy_extent_buffer(right, l, btrfs_item_nr_offset(0), | |
2798 | btrfs_item_nr_offset(mid), | |
2799 | nritems * sizeof(struct btrfs_item)); | |
2800 | ||
2801 | copy_extent_buffer(right, l, | |
2802 | btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) - | |
2803 | data_copy_size, btrfs_leaf_data(l) + | |
2804 | leaf_data_end(root, l), data_copy_size); | |
2805 | ||
2806 | rt_data_off = BTRFS_LEAF_DATA_SIZE(root) - | |
2807 | btrfs_item_end_nr(l, mid); | |
2808 | ||
2809 | for (i = 0; i < nritems; i++) { | |
2810 | struct btrfs_item *item = btrfs_item_nr(right, i); | |
2811 | u32 ioff; | |
2812 | ||
cfed81a0 CM |
2813 | ioff = btrfs_token_item_offset(right, item, &token); |
2814 | btrfs_set_token_item_offset(right, item, | |
2815 | ioff + rt_data_off, &token); | |
44871b1b CM |
2816 | } |
2817 | ||
44871b1b CM |
2818 | btrfs_set_header_nritems(l, mid); |
2819 | ret = 0; | |
2820 | btrfs_item_key(right, &disk_key, 0); | |
2821 | wret = insert_ptr(trans, root, path, &disk_key, right->start, | |
2822 | path->slots[1] + 1, 1); | |
2823 | if (wret) | |
2824 | ret = wret; | |
2825 | ||
2826 | btrfs_mark_buffer_dirty(right); | |
2827 | btrfs_mark_buffer_dirty(l); | |
2828 | BUG_ON(path->slots[0] != slot); | |
2829 | ||
44871b1b CM |
2830 | if (mid <= slot) { |
2831 | btrfs_tree_unlock(path->nodes[0]); | |
2832 | free_extent_buffer(path->nodes[0]); | |
2833 | path->nodes[0] = right; | |
2834 | path->slots[0] -= mid; | |
2835 | path->slots[1] += 1; | |
2836 | } else { | |
2837 | btrfs_tree_unlock(right); | |
2838 | free_extent_buffer(right); | |
2839 | } | |
2840 | ||
2841 | BUG_ON(path->slots[0] < 0); | |
2842 | ||
2843 | return ret; | |
2844 | } | |
2845 | ||
99d8f83c CM |
2846 | /* |
2847 | * double splits happen when we need to insert a big item in the middle | |
2848 | * of a leaf. A double split can leave us with 3 mostly empty leaves: | |
2849 | * leaf: [ slots 0 - N] [ our target ] [ N + 1 - total in leaf ] | |
2850 | * A B C | |
2851 | * | |
2852 | * We avoid this by trying to push the items on either side of our target | |
2853 | * into the adjacent leaves. If all goes well we can avoid the double split | |
2854 | * completely. | |
2855 | */ | |
2856 | static noinline int push_for_double_split(struct btrfs_trans_handle *trans, | |
2857 | struct btrfs_root *root, | |
2858 | struct btrfs_path *path, | |
2859 | int data_size) | |
2860 | { | |
2861 | int ret; | |
2862 | int progress = 0; | |
2863 | int slot; | |
2864 | u32 nritems; | |
2865 | ||
2866 | slot = path->slots[0]; | |
2867 | ||
2868 | /* | |
2869 | * try to push all the items after our slot into the | |
2870 | * right leaf | |
2871 | */ | |
2872 | ret = push_leaf_right(trans, root, path, 1, data_size, 0, slot); | |
2873 | if (ret < 0) | |
2874 | return ret; | |
2875 | ||
2876 | if (ret == 0) | |
2877 | progress++; | |
2878 | ||
2879 | nritems = btrfs_header_nritems(path->nodes[0]); | |
2880 | /* | |
2881 | * our goal is to get our slot at the start or end of a leaf. If | |
2882 | * we've done so we're done | |
2883 | */ | |
2884 | if (path->slots[0] == 0 || path->slots[0] == nritems) | |
2885 | return 0; | |
2886 | ||
2887 | if (btrfs_leaf_free_space(root, path->nodes[0]) >= data_size) | |
2888 | return 0; | |
2889 | ||
2890 | /* try to push all the items before our slot into the next leaf */ | |
2891 | slot = path->slots[0]; | |
2892 | ret = push_leaf_left(trans, root, path, 1, data_size, 0, slot); | |
2893 | if (ret < 0) | |
2894 | return ret; | |
2895 | ||
2896 | if (ret == 0) | |
2897 | progress++; | |
2898 | ||
2899 | if (progress) | |
2900 | return 0; | |
2901 | return 1; | |
2902 | } | |
2903 | ||
74123bd7 CM |
2904 | /* |
2905 | * split the path's leaf in two, making sure there is at least data_size | |
2906 | * available for the resulting leaf level of the path. | |
aa5d6bed CM |
2907 | * |
2908 | * returns 0 if all went well and < 0 on failure. | |
74123bd7 | 2909 | */ |
e02119d5 CM |
2910 | static noinline int split_leaf(struct btrfs_trans_handle *trans, |
2911 | struct btrfs_root *root, | |
2912 | struct btrfs_key *ins_key, | |
2913 | struct btrfs_path *path, int data_size, | |
2914 | int extend) | |
be0e5c09 | 2915 | { |
5d4f98a2 | 2916 | struct btrfs_disk_key disk_key; |
5f39d397 | 2917 | struct extent_buffer *l; |
7518a238 | 2918 | u32 nritems; |
eb60ceac CM |
2919 | int mid; |
2920 | int slot; | |
5f39d397 | 2921 | struct extent_buffer *right; |
d4dbff95 | 2922 | int ret = 0; |
aa5d6bed | 2923 | int wret; |
5d4f98a2 | 2924 | int split; |
cc0c5538 | 2925 | int num_doubles = 0; |
99d8f83c | 2926 | int tried_avoid_double = 0; |
aa5d6bed | 2927 | |
a5719521 YZ |
2928 | l = path->nodes[0]; |
2929 | slot = path->slots[0]; | |
2930 | if (extend && data_size + btrfs_item_size_nr(l, slot) + | |
2931 | sizeof(struct btrfs_item) > BTRFS_LEAF_DATA_SIZE(root)) | |
2932 | return -EOVERFLOW; | |
2933 | ||
40689478 | 2934 | /* first try to make some room by pushing left and right */ |
99d8f83c CM |
2935 | if (data_size) { |
2936 | wret = push_leaf_right(trans, root, path, data_size, | |
2937 | data_size, 0, 0); | |
d397712b | 2938 | if (wret < 0) |
eaee50e8 | 2939 | return wret; |
3685f791 | 2940 | if (wret) { |
99d8f83c CM |
2941 | wret = push_leaf_left(trans, root, path, data_size, |
2942 | data_size, 0, (u32)-1); | |
3685f791 CM |
2943 | if (wret < 0) |
2944 | return wret; | |
2945 | } | |
2946 | l = path->nodes[0]; | |
aa5d6bed | 2947 | |
3685f791 | 2948 | /* did the pushes work? */ |
87b29b20 | 2949 | if (btrfs_leaf_free_space(root, l) >= data_size) |
3685f791 | 2950 | return 0; |
3326d1b0 | 2951 | } |
aa5d6bed | 2952 | |
5c680ed6 | 2953 | if (!path->nodes[1]) { |
e089f05c | 2954 | ret = insert_new_root(trans, root, path, 1); |
5c680ed6 CM |
2955 | if (ret) |
2956 | return ret; | |
2957 | } | |
cc0c5538 | 2958 | again: |
5d4f98a2 | 2959 | split = 1; |
cc0c5538 | 2960 | l = path->nodes[0]; |
eb60ceac | 2961 | slot = path->slots[0]; |
5f39d397 | 2962 | nritems = btrfs_header_nritems(l); |
d397712b | 2963 | mid = (nritems + 1) / 2; |
54aa1f4d | 2964 | |
5d4f98a2 YZ |
2965 | if (mid <= slot) { |
2966 | if (nritems == 1 || | |
2967 | leaf_space_used(l, mid, nritems - mid) + data_size > | |
2968 | BTRFS_LEAF_DATA_SIZE(root)) { | |
2969 | if (slot >= nritems) { | |
2970 | split = 0; | |
2971 | } else { | |
2972 | mid = slot; | |
2973 | if (mid != nritems && | |
2974 | leaf_space_used(l, mid, nritems - mid) + | |
2975 | data_size > BTRFS_LEAF_DATA_SIZE(root)) { | |
99d8f83c CM |
2976 | if (data_size && !tried_avoid_double) |
2977 | goto push_for_double; | |
5d4f98a2 YZ |
2978 | split = 2; |
2979 | } | |
2980 | } | |
2981 | } | |
2982 | } else { | |
2983 | if (leaf_space_used(l, 0, mid) + data_size > | |
2984 | BTRFS_LEAF_DATA_SIZE(root)) { | |
2985 | if (!extend && data_size && slot == 0) { | |
2986 | split = 0; | |
2987 | } else if ((extend || !data_size) && slot == 0) { | |
2988 | mid = 1; | |
2989 | } else { | |
2990 | mid = slot; | |
2991 | if (mid != nritems && | |
2992 | leaf_space_used(l, mid, nritems - mid) + | |
2993 | data_size > BTRFS_LEAF_DATA_SIZE(root)) { | |
99d8f83c CM |
2994 | if (data_size && !tried_avoid_double) |
2995 | goto push_for_double; | |
5d4f98a2 YZ |
2996 | split = 2 ; |
2997 | } | |
2998 | } | |
2999 | } | |
3000 | } | |
3001 | ||
3002 | if (split == 0) | |
3003 | btrfs_cpu_key_to_disk(&disk_key, ins_key); | |
3004 | else | |
3005 | btrfs_item_key(l, &disk_key, mid); | |
3006 | ||
3007 | right = btrfs_alloc_free_block(trans, root, root->leafsize, 0, | |
31840ae1 | 3008 | root->root_key.objectid, |
66d7e7f0 | 3009 | &disk_key, 0, l->start, 0, 0); |
f0486c68 | 3010 | if (IS_ERR(right)) |
5f39d397 | 3011 | return PTR_ERR(right); |
f0486c68 YZ |
3012 | |
3013 | root_add_used(root, root->leafsize); | |
5f39d397 CM |
3014 | |
3015 | memset_extent_buffer(right, 0, 0, sizeof(struct btrfs_header)); | |
db94535d | 3016 | btrfs_set_header_bytenr(right, right->start); |
5f39d397 | 3017 | btrfs_set_header_generation(right, trans->transid); |
5d4f98a2 | 3018 | btrfs_set_header_backref_rev(right, BTRFS_MIXED_BACKREF_REV); |
5f39d397 CM |
3019 | btrfs_set_header_owner(right, root->root_key.objectid); |
3020 | btrfs_set_header_level(right, 0); | |
3021 | write_extent_buffer(right, root->fs_info->fsid, | |
3022 | (unsigned long)btrfs_header_fsid(right), | |
3023 | BTRFS_FSID_SIZE); | |
e17cade2 CM |
3024 | |
3025 | write_extent_buffer(right, root->fs_info->chunk_tree_uuid, | |
3026 | (unsigned long)btrfs_header_chunk_tree_uuid(right), | |
3027 | BTRFS_UUID_SIZE); | |
44871b1b | 3028 | |
5d4f98a2 YZ |
3029 | if (split == 0) { |
3030 | if (mid <= slot) { | |
3031 | btrfs_set_header_nritems(right, 0); | |
3032 | wret = insert_ptr(trans, root, path, | |
3033 | &disk_key, right->start, | |
3034 | path->slots[1] + 1, 1); | |
3035 | if (wret) | |
3036 | ret = wret; | |
925baedd | 3037 | |
5d4f98a2 YZ |
3038 | btrfs_tree_unlock(path->nodes[0]); |
3039 | free_extent_buffer(path->nodes[0]); | |
3040 | path->nodes[0] = right; | |
3041 | path->slots[0] = 0; | |
3042 | path->slots[1] += 1; | |
3043 | } else { | |
3044 | btrfs_set_header_nritems(right, 0); | |
3045 | wret = insert_ptr(trans, root, path, | |
3046 | &disk_key, | |
3047 | right->start, | |
3048 | path->slots[1], 1); | |
3049 | if (wret) | |
3050 | ret = wret; | |
3051 | btrfs_tree_unlock(path->nodes[0]); | |
3052 | free_extent_buffer(path->nodes[0]); | |
3053 | path->nodes[0] = right; | |
3054 | path->slots[0] = 0; | |
3055 | if (path->slots[1] == 0) { | |
3056 | wret = fixup_low_keys(trans, root, | |
3057 | path, &disk_key, 1); | |
d4dbff95 CM |
3058 | if (wret) |
3059 | ret = wret; | |
5ee78ac7 | 3060 | } |
d4dbff95 | 3061 | } |
5d4f98a2 YZ |
3062 | btrfs_mark_buffer_dirty(right); |
3063 | return ret; | |
d4dbff95 | 3064 | } |
74123bd7 | 3065 | |
44871b1b | 3066 | ret = copy_for_split(trans, root, path, l, right, slot, mid, nritems); |
31840ae1 ZY |
3067 | BUG_ON(ret); |
3068 | ||
5d4f98a2 | 3069 | if (split == 2) { |
cc0c5538 CM |
3070 | BUG_ON(num_doubles != 0); |
3071 | num_doubles++; | |
3072 | goto again; | |
a429e513 | 3073 | } |
44871b1b | 3074 | |
be0e5c09 | 3075 | return ret; |
99d8f83c CM |
3076 | |
3077 | push_for_double: | |
3078 | push_for_double_split(trans, root, path, data_size); | |
3079 | tried_avoid_double = 1; | |
3080 | if (btrfs_leaf_free_space(root, path->nodes[0]) >= data_size) | |
3081 | return 0; | |
3082 | goto again; | |
be0e5c09 CM |
3083 | } |
3084 | ||
ad48fd75 YZ |
3085 | static noinline int setup_leaf_for_split(struct btrfs_trans_handle *trans, |
3086 | struct btrfs_root *root, | |
3087 | struct btrfs_path *path, int ins_len) | |
459931ec | 3088 | { |
ad48fd75 | 3089 | struct btrfs_key key; |
459931ec | 3090 | struct extent_buffer *leaf; |
ad48fd75 YZ |
3091 | struct btrfs_file_extent_item *fi; |
3092 | u64 extent_len = 0; | |
3093 | u32 item_size; | |
3094 | int ret; | |
459931ec CM |
3095 | |
3096 | leaf = path->nodes[0]; | |
ad48fd75 YZ |
3097 | btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
3098 | ||
3099 | BUG_ON(key.type != BTRFS_EXTENT_DATA_KEY && | |
3100 | key.type != BTRFS_EXTENT_CSUM_KEY); | |
3101 | ||
3102 | if (btrfs_leaf_free_space(root, leaf) >= ins_len) | |
3103 | return 0; | |
459931ec CM |
3104 | |
3105 | item_size = btrfs_item_size_nr(leaf, path->slots[0]); | |
ad48fd75 YZ |
3106 | if (key.type == BTRFS_EXTENT_DATA_KEY) { |
3107 | fi = btrfs_item_ptr(leaf, path->slots[0], | |
3108 | struct btrfs_file_extent_item); | |
3109 | extent_len = btrfs_file_extent_num_bytes(leaf, fi); | |
3110 | } | |
b3b4aa74 | 3111 | btrfs_release_path(path); |
459931ec | 3112 | |
459931ec | 3113 | path->keep_locks = 1; |
ad48fd75 YZ |
3114 | path->search_for_split = 1; |
3115 | ret = btrfs_search_slot(trans, root, &key, path, 0, 1); | |
459931ec | 3116 | path->search_for_split = 0; |
ad48fd75 YZ |
3117 | if (ret < 0) |
3118 | goto err; | |
459931ec | 3119 | |
ad48fd75 YZ |
3120 | ret = -EAGAIN; |
3121 | leaf = path->nodes[0]; | |
459931ec | 3122 | /* if our item isn't there or got smaller, return now */ |
ad48fd75 YZ |
3123 | if (ret > 0 || item_size != btrfs_item_size_nr(leaf, path->slots[0])) |
3124 | goto err; | |
3125 | ||
109f6aef CM |
3126 | /* the leaf has changed, it now has room. return now */ |
3127 | if (btrfs_leaf_free_space(root, path->nodes[0]) >= ins_len) | |
3128 | goto err; | |
3129 | ||
ad48fd75 YZ |
3130 | if (key.type == BTRFS_EXTENT_DATA_KEY) { |
3131 | fi = btrfs_item_ptr(leaf, path->slots[0], | |
3132 | struct btrfs_file_extent_item); | |
3133 | if (extent_len != btrfs_file_extent_num_bytes(leaf, fi)) | |
3134 | goto err; | |
459931ec CM |
3135 | } |
3136 | ||
b9473439 | 3137 | btrfs_set_path_blocking(path); |
ad48fd75 | 3138 | ret = split_leaf(trans, root, &key, path, ins_len, 1); |
f0486c68 YZ |
3139 | if (ret) |
3140 | goto err; | |
459931ec | 3141 | |
ad48fd75 | 3142 | path->keep_locks = 0; |
b9473439 | 3143 | btrfs_unlock_up_safe(path, 1); |
ad48fd75 YZ |
3144 | return 0; |
3145 | err: | |
3146 | path->keep_locks = 0; | |
3147 | return ret; | |
3148 | } | |
3149 | ||
3150 | static noinline int split_item(struct btrfs_trans_handle *trans, | |
3151 | struct btrfs_root *root, | |
3152 | struct btrfs_path *path, | |
3153 | struct btrfs_key *new_key, | |
3154 | unsigned long split_offset) | |
3155 | { | |
3156 | struct extent_buffer *leaf; | |
3157 | struct btrfs_item *item; | |
3158 | struct btrfs_item *new_item; | |
3159 | int slot; | |
3160 | char *buf; | |
3161 | u32 nritems; | |
3162 | u32 item_size; | |
3163 | u32 orig_offset; | |
3164 | struct btrfs_disk_key disk_key; | |
3165 | ||
b9473439 CM |
3166 | leaf = path->nodes[0]; |
3167 | BUG_ON(btrfs_leaf_free_space(root, leaf) < sizeof(struct btrfs_item)); | |
3168 | ||
b4ce94de CM |
3169 | btrfs_set_path_blocking(path); |
3170 | ||
459931ec CM |
3171 | item = btrfs_item_nr(leaf, path->slots[0]); |
3172 | orig_offset = btrfs_item_offset(leaf, item); | |
3173 | item_size = btrfs_item_size(leaf, item); | |
3174 | ||
459931ec | 3175 | buf = kmalloc(item_size, GFP_NOFS); |
ad48fd75 YZ |
3176 | if (!buf) |
3177 | return -ENOMEM; | |
3178 | ||
459931ec CM |
3179 | read_extent_buffer(leaf, buf, btrfs_item_ptr_offset(leaf, |
3180 | path->slots[0]), item_size); | |
459931ec | 3181 | |
ad48fd75 | 3182 | slot = path->slots[0] + 1; |
459931ec | 3183 | nritems = btrfs_header_nritems(leaf); |
459931ec CM |
3184 | if (slot != nritems) { |
3185 | /* shift the items */ | |
3186 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + 1), | |
ad48fd75 YZ |
3187 | btrfs_item_nr_offset(slot), |
3188 | (nritems - slot) * sizeof(struct btrfs_item)); | |
459931ec CM |
3189 | } |
3190 | ||
3191 | btrfs_cpu_key_to_disk(&disk_key, new_key); | |
3192 | btrfs_set_item_key(leaf, &disk_key, slot); | |
3193 | ||
3194 | new_item = btrfs_item_nr(leaf, slot); | |
3195 | ||
3196 | btrfs_set_item_offset(leaf, new_item, orig_offset); | |
3197 | btrfs_set_item_size(leaf, new_item, item_size - split_offset); | |
3198 | ||
3199 | btrfs_set_item_offset(leaf, item, | |
3200 | orig_offset + item_size - split_offset); | |
3201 | btrfs_set_item_size(leaf, item, split_offset); | |
3202 | ||
3203 | btrfs_set_header_nritems(leaf, nritems + 1); | |
3204 | ||
3205 | /* write the data for the start of the original item */ | |
3206 | write_extent_buffer(leaf, buf, | |
3207 | btrfs_item_ptr_offset(leaf, path->slots[0]), | |
3208 | split_offset); | |
3209 | ||
3210 | /* write the data for the new item */ | |
3211 | write_extent_buffer(leaf, buf + split_offset, | |
3212 | btrfs_item_ptr_offset(leaf, slot), | |
3213 | item_size - split_offset); | |
3214 | btrfs_mark_buffer_dirty(leaf); | |
3215 | ||
ad48fd75 | 3216 | BUG_ON(btrfs_leaf_free_space(root, leaf) < 0); |
459931ec | 3217 | kfree(buf); |
ad48fd75 YZ |
3218 | return 0; |
3219 | } | |
3220 | ||
3221 | /* | |
3222 | * This function splits a single item into two items, | |
3223 | * giving 'new_key' to the new item and splitting the | |
3224 | * old one at split_offset (from the start of the item). | |
3225 | * | |
3226 | * The path may be released by this operation. After | |
3227 | * the split, the path is pointing to the old item. The | |
3228 | * new item is going to be in the same node as the old one. | |
3229 | * | |
3230 | * Note, the item being split must be smaller enough to live alone on | |
3231 | * a tree block with room for one extra struct btrfs_item | |
3232 | * | |
3233 | * This allows us to split the item in place, keeping a lock on the | |
3234 | * leaf the entire time. | |
3235 | */ | |
3236 | int btrfs_split_item(struct btrfs_trans_handle *trans, | |
3237 | struct btrfs_root *root, | |
3238 | struct btrfs_path *path, | |
3239 | struct btrfs_key *new_key, | |
3240 | unsigned long split_offset) | |
3241 | { | |
3242 | int ret; | |
3243 | ret = setup_leaf_for_split(trans, root, path, | |
3244 | sizeof(struct btrfs_item)); | |
3245 | if (ret) | |
3246 | return ret; | |
3247 | ||
3248 | ret = split_item(trans, root, path, new_key, split_offset); | |
459931ec CM |
3249 | return ret; |
3250 | } | |
3251 | ||
ad48fd75 YZ |
3252 | /* |
3253 | * This function duplicate a item, giving 'new_key' to the new item. | |
3254 | * It guarantees both items live in the same tree leaf and the new item | |
3255 | * is contiguous with the original item. | |
3256 | * | |
3257 | * This allows us to split file extent in place, keeping a lock on the | |
3258 | * leaf the entire time. | |
3259 | */ | |
3260 | int btrfs_duplicate_item(struct btrfs_trans_handle *trans, | |
3261 | struct btrfs_root *root, | |
3262 | struct btrfs_path *path, | |
3263 | struct btrfs_key *new_key) | |
3264 | { | |
3265 | struct extent_buffer *leaf; | |
3266 | int ret; | |
3267 | u32 item_size; | |
3268 | ||
3269 | leaf = path->nodes[0]; | |
3270 | item_size = btrfs_item_size_nr(leaf, path->slots[0]); | |
3271 | ret = setup_leaf_for_split(trans, root, path, | |
3272 | item_size + sizeof(struct btrfs_item)); | |
3273 | if (ret) | |
3274 | return ret; | |
3275 | ||
3276 | path->slots[0]++; | |
3277 | ret = setup_items_for_insert(trans, root, path, new_key, &item_size, | |
3278 | item_size, item_size + | |
3279 | sizeof(struct btrfs_item), 1); | |
3280 | BUG_ON(ret); | |
3281 | ||
3282 | leaf = path->nodes[0]; | |
3283 | memcpy_extent_buffer(leaf, | |
3284 | btrfs_item_ptr_offset(leaf, path->slots[0]), | |
3285 | btrfs_item_ptr_offset(leaf, path->slots[0] - 1), | |
3286 | item_size); | |
3287 | return 0; | |
3288 | } | |
3289 | ||
d352ac68 CM |
3290 | /* |
3291 | * make the item pointed to by the path smaller. new_size indicates | |
3292 | * how small to make it, and from_end tells us if we just chop bytes | |
3293 | * off the end of the item or if we shift the item to chop bytes off | |
3294 | * the front. | |
3295 | */ | |
b18c6685 CM |
3296 | int btrfs_truncate_item(struct btrfs_trans_handle *trans, |
3297 | struct btrfs_root *root, | |
3298 | struct btrfs_path *path, | |
179e29e4 | 3299 | u32 new_size, int from_end) |
b18c6685 | 3300 | { |
b18c6685 | 3301 | int slot; |
5f39d397 CM |
3302 | struct extent_buffer *leaf; |
3303 | struct btrfs_item *item; | |
b18c6685 CM |
3304 | u32 nritems; |
3305 | unsigned int data_end; | |
3306 | unsigned int old_data_start; | |
3307 | unsigned int old_size; | |
3308 | unsigned int size_diff; | |
3309 | int i; | |
cfed81a0 CM |
3310 | struct btrfs_map_token token; |
3311 | ||
3312 | btrfs_init_map_token(&token); | |
b18c6685 | 3313 | |
5f39d397 | 3314 | leaf = path->nodes[0]; |
179e29e4 CM |
3315 | slot = path->slots[0]; |
3316 | ||
3317 | old_size = btrfs_item_size_nr(leaf, slot); | |
3318 | if (old_size == new_size) | |
3319 | return 0; | |
b18c6685 | 3320 | |
5f39d397 | 3321 | nritems = btrfs_header_nritems(leaf); |
b18c6685 CM |
3322 | data_end = leaf_data_end(root, leaf); |
3323 | ||
5f39d397 | 3324 | old_data_start = btrfs_item_offset_nr(leaf, slot); |
179e29e4 | 3325 | |
b18c6685 CM |
3326 | size_diff = old_size - new_size; |
3327 | ||
3328 | BUG_ON(slot < 0); | |
3329 | BUG_ON(slot >= nritems); | |
3330 | ||
3331 | /* | |
3332 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
3333 | */ | |
3334 | /* first correct the data pointers */ | |
3335 | for (i = slot; i < nritems; i++) { | |
5f39d397 CM |
3336 | u32 ioff; |
3337 | item = btrfs_item_nr(leaf, i); | |
db94535d | 3338 | |
cfed81a0 CM |
3339 | ioff = btrfs_token_item_offset(leaf, item, &token); |
3340 | btrfs_set_token_item_offset(leaf, item, | |
3341 | ioff + size_diff, &token); | |
b18c6685 | 3342 | } |
db94535d | 3343 | |
b18c6685 | 3344 | /* shift the data */ |
179e29e4 CM |
3345 | if (from_end) { |
3346 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + | |
3347 | data_end + size_diff, btrfs_leaf_data(leaf) + | |
3348 | data_end, old_data_start + new_size - data_end); | |
3349 | } else { | |
3350 | struct btrfs_disk_key disk_key; | |
3351 | u64 offset; | |
3352 | ||
3353 | btrfs_item_key(leaf, &disk_key, slot); | |
3354 | ||
3355 | if (btrfs_disk_key_type(&disk_key) == BTRFS_EXTENT_DATA_KEY) { | |
3356 | unsigned long ptr; | |
3357 | struct btrfs_file_extent_item *fi; | |
3358 | ||
3359 | fi = btrfs_item_ptr(leaf, slot, | |
3360 | struct btrfs_file_extent_item); | |
3361 | fi = (struct btrfs_file_extent_item *)( | |
3362 | (unsigned long)fi - size_diff); | |
3363 | ||
3364 | if (btrfs_file_extent_type(leaf, fi) == | |
3365 | BTRFS_FILE_EXTENT_INLINE) { | |
3366 | ptr = btrfs_item_ptr_offset(leaf, slot); | |
3367 | memmove_extent_buffer(leaf, ptr, | |
d397712b CM |
3368 | (unsigned long)fi, |
3369 | offsetof(struct btrfs_file_extent_item, | |
179e29e4 CM |
3370 | disk_bytenr)); |
3371 | } | |
3372 | } | |
3373 | ||
3374 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + | |
3375 | data_end + size_diff, btrfs_leaf_data(leaf) + | |
3376 | data_end, old_data_start - data_end); | |
3377 | ||
3378 | offset = btrfs_disk_key_offset(&disk_key); | |
3379 | btrfs_set_disk_key_offset(&disk_key, offset + size_diff); | |
3380 | btrfs_set_item_key(leaf, &disk_key, slot); | |
3381 | if (slot == 0) | |
3382 | fixup_low_keys(trans, root, path, &disk_key, 1); | |
3383 | } | |
5f39d397 CM |
3384 | |
3385 | item = btrfs_item_nr(leaf, slot); | |
3386 | btrfs_set_item_size(leaf, item, new_size); | |
3387 | btrfs_mark_buffer_dirty(leaf); | |
b18c6685 | 3388 | |
5f39d397 CM |
3389 | if (btrfs_leaf_free_space(root, leaf) < 0) { |
3390 | btrfs_print_leaf(root, leaf); | |
b18c6685 | 3391 | BUG(); |
5f39d397 | 3392 | } |
1cd30799 | 3393 | return 0; |
b18c6685 CM |
3394 | } |
3395 | ||
d352ac68 CM |
3396 | /* |
3397 | * make the item pointed to by the path bigger, data_size is the new size. | |
3398 | */ | |
5f39d397 CM |
3399 | int btrfs_extend_item(struct btrfs_trans_handle *trans, |
3400 | struct btrfs_root *root, struct btrfs_path *path, | |
3401 | u32 data_size) | |
6567e837 | 3402 | { |
6567e837 | 3403 | int slot; |
5f39d397 CM |
3404 | struct extent_buffer *leaf; |
3405 | struct btrfs_item *item; | |
6567e837 CM |
3406 | u32 nritems; |
3407 | unsigned int data_end; | |
3408 | unsigned int old_data; | |
3409 | unsigned int old_size; | |
3410 | int i; | |
cfed81a0 CM |
3411 | struct btrfs_map_token token; |
3412 | ||
3413 | btrfs_init_map_token(&token); | |
6567e837 | 3414 | |
5f39d397 | 3415 | leaf = path->nodes[0]; |
6567e837 | 3416 | |
5f39d397 | 3417 | nritems = btrfs_header_nritems(leaf); |
6567e837 CM |
3418 | data_end = leaf_data_end(root, leaf); |
3419 | ||
5f39d397 CM |
3420 | if (btrfs_leaf_free_space(root, leaf) < data_size) { |
3421 | btrfs_print_leaf(root, leaf); | |
6567e837 | 3422 | BUG(); |
5f39d397 | 3423 | } |
6567e837 | 3424 | slot = path->slots[0]; |
5f39d397 | 3425 | old_data = btrfs_item_end_nr(leaf, slot); |
6567e837 CM |
3426 | |
3427 | BUG_ON(slot < 0); | |
3326d1b0 CM |
3428 | if (slot >= nritems) { |
3429 | btrfs_print_leaf(root, leaf); | |
d397712b CM |
3430 | printk(KERN_CRIT "slot %d too large, nritems %d\n", |
3431 | slot, nritems); | |
3326d1b0 CM |
3432 | BUG_ON(1); |
3433 | } | |
6567e837 CM |
3434 | |
3435 | /* | |
3436 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
3437 | */ | |
3438 | /* first correct the data pointers */ | |
3439 | for (i = slot; i < nritems; i++) { | |
5f39d397 CM |
3440 | u32 ioff; |
3441 | item = btrfs_item_nr(leaf, i); | |
db94535d | 3442 | |
cfed81a0 CM |
3443 | ioff = btrfs_token_item_offset(leaf, item, &token); |
3444 | btrfs_set_token_item_offset(leaf, item, | |
3445 | ioff - data_size, &token); | |
6567e837 | 3446 | } |
5f39d397 | 3447 | |
6567e837 | 3448 | /* shift the data */ |
5f39d397 | 3449 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + |
6567e837 CM |
3450 | data_end - data_size, btrfs_leaf_data(leaf) + |
3451 | data_end, old_data - data_end); | |
5f39d397 | 3452 | |
6567e837 | 3453 | data_end = old_data; |
5f39d397 CM |
3454 | old_size = btrfs_item_size_nr(leaf, slot); |
3455 | item = btrfs_item_nr(leaf, slot); | |
3456 | btrfs_set_item_size(leaf, item, old_size + data_size); | |
3457 | btrfs_mark_buffer_dirty(leaf); | |
6567e837 | 3458 | |
5f39d397 CM |
3459 | if (btrfs_leaf_free_space(root, leaf) < 0) { |
3460 | btrfs_print_leaf(root, leaf); | |
6567e837 | 3461 | BUG(); |
5f39d397 | 3462 | } |
1cd30799 | 3463 | return 0; |
6567e837 CM |
3464 | } |
3465 | ||
f3465ca4 JB |
3466 | /* |
3467 | * Given a key and some data, insert items into the tree. | |
3468 | * This does all the path init required, making room in the tree if needed. | |
3469 | * Returns the number of keys that were inserted. | |
3470 | */ | |
3471 | int btrfs_insert_some_items(struct btrfs_trans_handle *trans, | |
3472 | struct btrfs_root *root, | |
3473 | struct btrfs_path *path, | |
3474 | struct btrfs_key *cpu_key, u32 *data_size, | |
3475 | int nr) | |
3476 | { | |
3477 | struct extent_buffer *leaf; | |
3478 | struct btrfs_item *item; | |
3479 | int ret = 0; | |
3480 | int slot; | |
f3465ca4 JB |
3481 | int i; |
3482 | u32 nritems; | |
3483 | u32 total_data = 0; | |
3484 | u32 total_size = 0; | |
3485 | unsigned int data_end; | |
3486 | struct btrfs_disk_key disk_key; | |
3487 | struct btrfs_key found_key; | |
cfed81a0 CM |
3488 | struct btrfs_map_token token; |
3489 | ||
3490 | btrfs_init_map_token(&token); | |
f3465ca4 | 3491 | |
87b29b20 YZ |
3492 | for (i = 0; i < nr; i++) { |
3493 | if (total_size + data_size[i] + sizeof(struct btrfs_item) > | |
3494 | BTRFS_LEAF_DATA_SIZE(root)) { | |
3495 | break; | |
3496 | nr = i; | |
3497 | } | |
f3465ca4 | 3498 | total_data += data_size[i]; |
87b29b20 YZ |
3499 | total_size += data_size[i] + sizeof(struct btrfs_item); |
3500 | } | |
3501 | BUG_ON(nr == 0); | |
f3465ca4 | 3502 | |
f3465ca4 JB |
3503 | ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1); |
3504 | if (ret == 0) | |
3505 | return -EEXIST; | |
3506 | if (ret < 0) | |
3507 | goto out; | |
3508 | ||
f3465ca4 JB |
3509 | leaf = path->nodes[0]; |
3510 | ||
3511 | nritems = btrfs_header_nritems(leaf); | |
3512 | data_end = leaf_data_end(root, leaf); | |
3513 | ||
3514 | if (btrfs_leaf_free_space(root, leaf) < total_size) { | |
3515 | for (i = nr; i >= 0; i--) { | |
3516 | total_data -= data_size[i]; | |
3517 | total_size -= data_size[i] + sizeof(struct btrfs_item); | |
3518 | if (total_size < btrfs_leaf_free_space(root, leaf)) | |
3519 | break; | |
3520 | } | |
3521 | nr = i; | |
3522 | } | |
3523 | ||
3524 | slot = path->slots[0]; | |
3525 | BUG_ON(slot < 0); | |
3526 | ||
3527 | if (slot != nritems) { | |
3528 | unsigned int old_data = btrfs_item_end_nr(leaf, slot); | |
3529 | ||
3530 | item = btrfs_item_nr(leaf, slot); | |
3531 | btrfs_item_key_to_cpu(leaf, &found_key, slot); | |
3532 | ||
3533 | /* figure out how many keys we can insert in here */ | |
3534 | total_data = data_size[0]; | |
3535 | for (i = 1; i < nr; i++) { | |
5d4f98a2 | 3536 | if (btrfs_comp_cpu_keys(&found_key, cpu_key + i) <= 0) |
f3465ca4 JB |
3537 | break; |
3538 | total_data += data_size[i]; | |
3539 | } | |
3540 | nr = i; | |
3541 | ||
3542 | if (old_data < data_end) { | |
3543 | btrfs_print_leaf(root, leaf); | |
d397712b | 3544 | printk(KERN_CRIT "slot %d old_data %d data_end %d\n", |
f3465ca4 JB |
3545 | slot, old_data, data_end); |
3546 | BUG_ON(1); | |
3547 | } | |
3548 | /* | |
3549 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
3550 | */ | |
3551 | /* first correct the data pointers */ | |
f3465ca4 JB |
3552 | for (i = slot; i < nritems; i++) { |
3553 | u32 ioff; | |
3554 | ||
3555 | item = btrfs_item_nr(leaf, i); | |
cfed81a0 CM |
3556 | ioff = btrfs_token_item_offset(leaf, item, &token); |
3557 | btrfs_set_token_item_offset(leaf, item, | |
3558 | ioff - total_data, &token); | |
f3465ca4 | 3559 | } |
f3465ca4 JB |
3560 | /* shift the items */ |
3561 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr), | |
3562 | btrfs_item_nr_offset(slot), | |
3563 | (nritems - slot) * sizeof(struct btrfs_item)); | |
3564 | ||
3565 | /* shift the data */ | |
3566 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + | |
3567 | data_end - total_data, btrfs_leaf_data(leaf) + | |
3568 | data_end, old_data - data_end); | |
3569 | data_end = old_data; | |
3570 | } else { | |
3571 | /* | |
3572 | * this sucks but it has to be done, if we are inserting at | |
3573 | * the end of the leaf only insert 1 of the items, since we | |
3574 | * have no way of knowing whats on the next leaf and we'd have | |
3575 | * to drop our current locks to figure it out | |
3576 | */ | |
3577 | nr = 1; | |
3578 | } | |
3579 | ||
3580 | /* setup the item for the new data */ | |
3581 | for (i = 0; i < nr; i++) { | |
3582 | btrfs_cpu_key_to_disk(&disk_key, cpu_key + i); | |
3583 | btrfs_set_item_key(leaf, &disk_key, slot + i); | |
3584 | item = btrfs_item_nr(leaf, slot + i); | |
cfed81a0 CM |
3585 | btrfs_set_token_item_offset(leaf, item, |
3586 | data_end - data_size[i], &token); | |
f3465ca4 | 3587 | data_end -= data_size[i]; |
cfed81a0 | 3588 | btrfs_set_token_item_size(leaf, item, data_size[i], &token); |
f3465ca4 JB |
3589 | } |
3590 | btrfs_set_header_nritems(leaf, nritems + nr); | |
3591 | btrfs_mark_buffer_dirty(leaf); | |
3592 | ||
3593 | ret = 0; | |
3594 | if (slot == 0) { | |
3595 | btrfs_cpu_key_to_disk(&disk_key, cpu_key); | |
3596 | ret = fixup_low_keys(trans, root, path, &disk_key, 1); | |
3597 | } | |
3598 | ||
3599 | if (btrfs_leaf_free_space(root, leaf) < 0) { | |
3600 | btrfs_print_leaf(root, leaf); | |
3601 | BUG(); | |
3602 | } | |
3603 | out: | |
3604 | if (!ret) | |
3605 | ret = nr; | |
3606 | return ret; | |
3607 | } | |
3608 | ||
74123bd7 | 3609 | /* |
44871b1b CM |
3610 | * this is a helper for btrfs_insert_empty_items, the main goal here is |
3611 | * to save stack depth by doing the bulk of the work in a function | |
3612 | * that doesn't call btrfs_search_slot | |
74123bd7 | 3613 | */ |
16cdcec7 MX |
3614 | int setup_items_for_insert(struct btrfs_trans_handle *trans, |
3615 | struct btrfs_root *root, struct btrfs_path *path, | |
3616 | struct btrfs_key *cpu_key, u32 *data_size, | |
3617 | u32 total_data, u32 total_size, int nr) | |
be0e5c09 | 3618 | { |
5f39d397 | 3619 | struct btrfs_item *item; |
9c58309d | 3620 | int i; |
7518a238 | 3621 | u32 nritems; |
be0e5c09 | 3622 | unsigned int data_end; |
e2fa7227 | 3623 | struct btrfs_disk_key disk_key; |
44871b1b CM |
3624 | int ret; |
3625 | struct extent_buffer *leaf; | |
3626 | int slot; | |
cfed81a0 CM |
3627 | struct btrfs_map_token token; |
3628 | ||
3629 | btrfs_init_map_token(&token); | |
e2fa7227 | 3630 | |
5f39d397 | 3631 | leaf = path->nodes[0]; |
44871b1b | 3632 | slot = path->slots[0]; |
74123bd7 | 3633 | |
5f39d397 | 3634 | nritems = btrfs_header_nritems(leaf); |
123abc88 | 3635 | data_end = leaf_data_end(root, leaf); |
eb60ceac | 3636 | |
f25956cc | 3637 | if (btrfs_leaf_free_space(root, leaf) < total_size) { |
3326d1b0 | 3638 | btrfs_print_leaf(root, leaf); |
d397712b | 3639 | printk(KERN_CRIT "not enough freespace need %u have %d\n", |
9c58309d | 3640 | total_size, btrfs_leaf_free_space(root, leaf)); |
be0e5c09 | 3641 | BUG(); |
d4dbff95 | 3642 | } |
5f39d397 | 3643 | |
be0e5c09 | 3644 | if (slot != nritems) { |
5f39d397 | 3645 | unsigned int old_data = btrfs_item_end_nr(leaf, slot); |
be0e5c09 | 3646 | |
5f39d397 CM |
3647 | if (old_data < data_end) { |
3648 | btrfs_print_leaf(root, leaf); | |
d397712b | 3649 | printk(KERN_CRIT "slot %d old_data %d data_end %d\n", |
5f39d397 CM |
3650 | slot, old_data, data_end); |
3651 | BUG_ON(1); | |
3652 | } | |
be0e5c09 CM |
3653 | /* |
3654 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
3655 | */ | |
3656 | /* first correct the data pointers */ | |
0783fcfc | 3657 | for (i = slot; i < nritems; i++) { |
5f39d397 | 3658 | u32 ioff; |
db94535d | 3659 | |
5f39d397 | 3660 | item = btrfs_item_nr(leaf, i); |
cfed81a0 CM |
3661 | ioff = btrfs_token_item_offset(leaf, item, &token); |
3662 | btrfs_set_token_item_offset(leaf, item, | |
3663 | ioff - total_data, &token); | |
0783fcfc | 3664 | } |
be0e5c09 | 3665 | /* shift the items */ |
9c58309d | 3666 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr), |
5f39d397 | 3667 | btrfs_item_nr_offset(slot), |
d6025579 | 3668 | (nritems - slot) * sizeof(struct btrfs_item)); |
be0e5c09 CM |
3669 | |
3670 | /* shift the data */ | |
5f39d397 | 3671 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + |
9c58309d | 3672 | data_end - total_data, btrfs_leaf_data(leaf) + |
d6025579 | 3673 | data_end, old_data - data_end); |
be0e5c09 CM |
3674 | data_end = old_data; |
3675 | } | |
5f39d397 | 3676 | |
62e2749e | 3677 | /* setup the item for the new data */ |
9c58309d CM |
3678 | for (i = 0; i < nr; i++) { |
3679 | btrfs_cpu_key_to_disk(&disk_key, cpu_key + i); | |
3680 | btrfs_set_item_key(leaf, &disk_key, slot + i); | |
3681 | item = btrfs_item_nr(leaf, slot + i); | |
cfed81a0 CM |
3682 | btrfs_set_token_item_offset(leaf, item, |
3683 | data_end - data_size[i], &token); | |
9c58309d | 3684 | data_end -= data_size[i]; |
cfed81a0 | 3685 | btrfs_set_token_item_size(leaf, item, data_size[i], &token); |
9c58309d | 3686 | } |
44871b1b | 3687 | |
9c58309d | 3688 | btrfs_set_header_nritems(leaf, nritems + nr); |
aa5d6bed CM |
3689 | |
3690 | ret = 0; | |
5a01a2e3 CM |
3691 | if (slot == 0) { |
3692 | btrfs_cpu_key_to_disk(&disk_key, cpu_key); | |
e089f05c | 3693 | ret = fixup_low_keys(trans, root, path, &disk_key, 1); |
5a01a2e3 | 3694 | } |
b9473439 CM |
3695 | btrfs_unlock_up_safe(path, 1); |
3696 | btrfs_mark_buffer_dirty(leaf); | |
aa5d6bed | 3697 | |
5f39d397 CM |
3698 | if (btrfs_leaf_free_space(root, leaf) < 0) { |
3699 | btrfs_print_leaf(root, leaf); | |
be0e5c09 | 3700 | BUG(); |
5f39d397 | 3701 | } |
44871b1b CM |
3702 | return ret; |
3703 | } | |
3704 | ||
3705 | /* | |
3706 | * Given a key and some data, insert items into the tree. | |
3707 | * This does all the path init required, making room in the tree if needed. | |
3708 | */ | |
3709 | int btrfs_insert_empty_items(struct btrfs_trans_handle *trans, | |
3710 | struct btrfs_root *root, | |
3711 | struct btrfs_path *path, | |
3712 | struct btrfs_key *cpu_key, u32 *data_size, | |
3713 | int nr) | |
3714 | { | |
44871b1b CM |
3715 | int ret = 0; |
3716 | int slot; | |
3717 | int i; | |
3718 | u32 total_size = 0; | |
3719 | u32 total_data = 0; | |
3720 | ||
3721 | for (i = 0; i < nr; i++) | |
3722 | total_data += data_size[i]; | |
3723 | ||
3724 | total_size = total_data + (nr * sizeof(struct btrfs_item)); | |
3725 | ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1); | |
3726 | if (ret == 0) | |
3727 | return -EEXIST; | |
3728 | if (ret < 0) | |
3729 | goto out; | |
3730 | ||
44871b1b CM |
3731 | slot = path->slots[0]; |
3732 | BUG_ON(slot < 0); | |
3733 | ||
3734 | ret = setup_items_for_insert(trans, root, path, cpu_key, data_size, | |
3735 | total_data, total_size, nr); | |
3736 | ||
ed2ff2cb | 3737 | out: |
62e2749e CM |
3738 | return ret; |
3739 | } | |
3740 | ||
3741 | /* | |
3742 | * Given a key and some data, insert an item into the tree. | |
3743 | * This does all the path init required, making room in the tree if needed. | |
3744 | */ | |
e089f05c CM |
3745 | int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root |
3746 | *root, struct btrfs_key *cpu_key, void *data, u32 | |
3747 | data_size) | |
62e2749e CM |
3748 | { |
3749 | int ret = 0; | |
2c90e5d6 | 3750 | struct btrfs_path *path; |
5f39d397 CM |
3751 | struct extent_buffer *leaf; |
3752 | unsigned long ptr; | |
62e2749e | 3753 | |
2c90e5d6 | 3754 | path = btrfs_alloc_path(); |
db5b493a TI |
3755 | if (!path) |
3756 | return -ENOMEM; | |
2c90e5d6 | 3757 | ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size); |
62e2749e | 3758 | if (!ret) { |
5f39d397 CM |
3759 | leaf = path->nodes[0]; |
3760 | ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); | |
3761 | write_extent_buffer(leaf, data, ptr, data_size); | |
3762 | btrfs_mark_buffer_dirty(leaf); | |
62e2749e | 3763 | } |
2c90e5d6 | 3764 | btrfs_free_path(path); |
aa5d6bed | 3765 | return ret; |
be0e5c09 CM |
3766 | } |
3767 | ||
74123bd7 | 3768 | /* |
5de08d7d | 3769 | * delete the pointer from a given node. |
74123bd7 | 3770 | * |
d352ac68 CM |
3771 | * the tree should have been previously balanced so the deletion does not |
3772 | * empty a node. | |
74123bd7 | 3773 | */ |
e089f05c CM |
3774 | static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
3775 | struct btrfs_path *path, int level, int slot) | |
be0e5c09 | 3776 | { |
5f39d397 | 3777 | struct extent_buffer *parent = path->nodes[level]; |
7518a238 | 3778 | u32 nritems; |
aa5d6bed | 3779 | int ret = 0; |
bb803951 | 3780 | int wret; |
be0e5c09 | 3781 | |
5f39d397 | 3782 | nritems = btrfs_header_nritems(parent); |
d397712b | 3783 | if (slot != nritems - 1) { |
5f39d397 CM |
3784 | memmove_extent_buffer(parent, |
3785 | btrfs_node_key_ptr_offset(slot), | |
3786 | btrfs_node_key_ptr_offset(slot + 1), | |
d6025579 CM |
3787 | sizeof(struct btrfs_key_ptr) * |
3788 | (nritems - slot - 1)); | |
bb803951 | 3789 | } |
7518a238 | 3790 | nritems--; |
5f39d397 | 3791 | btrfs_set_header_nritems(parent, nritems); |
7518a238 | 3792 | if (nritems == 0 && parent == root->node) { |
5f39d397 | 3793 | BUG_ON(btrfs_header_level(root->node) != 1); |
bb803951 | 3794 | /* just turn the root into a leaf and break */ |
5f39d397 | 3795 | btrfs_set_header_level(root->node, 0); |
bb803951 | 3796 | } else if (slot == 0) { |
5f39d397 CM |
3797 | struct btrfs_disk_key disk_key; |
3798 | ||
3799 | btrfs_node_key(parent, &disk_key, 0); | |
3800 | wret = fixup_low_keys(trans, root, path, &disk_key, level + 1); | |
0f70abe2 CM |
3801 | if (wret) |
3802 | ret = wret; | |
be0e5c09 | 3803 | } |
d6025579 | 3804 | btrfs_mark_buffer_dirty(parent); |
aa5d6bed | 3805 | return ret; |
be0e5c09 CM |
3806 | } |
3807 | ||
323ac95b CM |
3808 | /* |
3809 | * a helper function to delete the leaf pointed to by path->slots[1] and | |
5d4f98a2 | 3810 | * path->nodes[1]. |
323ac95b CM |
3811 | * |
3812 | * This deletes the pointer in path->nodes[1] and frees the leaf | |
3813 | * block extent. zero is returned if it all worked out, < 0 otherwise. | |
3814 | * | |
3815 | * The path must have already been setup for deleting the leaf, including | |
3816 | * all the proper balancing. path->nodes[1] must be locked. | |
3817 | */ | |
5d4f98a2 YZ |
3818 | static noinline int btrfs_del_leaf(struct btrfs_trans_handle *trans, |
3819 | struct btrfs_root *root, | |
3820 | struct btrfs_path *path, | |
3821 | struct extent_buffer *leaf) | |
323ac95b CM |
3822 | { |
3823 | int ret; | |
323ac95b | 3824 | |
5d4f98a2 | 3825 | WARN_ON(btrfs_header_generation(leaf) != trans->transid); |
323ac95b CM |
3826 | ret = del_ptr(trans, root, path, 1, path->slots[1]); |
3827 | if (ret) | |
3828 | return ret; | |
3829 | ||
4d081c41 CM |
3830 | /* |
3831 | * btrfs_free_extent is expensive, we want to make sure we | |
3832 | * aren't holding any locks when we call it | |
3833 | */ | |
3834 | btrfs_unlock_up_safe(path, 0); | |
3835 | ||
f0486c68 YZ |
3836 | root_sub_used(root, leaf->len); |
3837 | ||
3083ee2e | 3838 | extent_buffer_get(leaf); |
66d7e7f0 | 3839 | btrfs_free_tree_block(trans, root, leaf, 0, 1, 0); |
3083ee2e | 3840 | free_extent_buffer_stale(leaf); |
f0486c68 | 3841 | return 0; |
323ac95b | 3842 | } |
74123bd7 CM |
3843 | /* |
3844 | * delete the item at the leaf level in path. If that empties | |
3845 | * the leaf, remove it from the tree | |
3846 | */ | |
85e21bac CM |
3847 | int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
3848 | struct btrfs_path *path, int slot, int nr) | |
be0e5c09 | 3849 | { |
5f39d397 CM |
3850 | struct extent_buffer *leaf; |
3851 | struct btrfs_item *item; | |
85e21bac CM |
3852 | int last_off; |
3853 | int dsize = 0; | |
aa5d6bed CM |
3854 | int ret = 0; |
3855 | int wret; | |
85e21bac | 3856 | int i; |
7518a238 | 3857 | u32 nritems; |
cfed81a0 CM |
3858 | struct btrfs_map_token token; |
3859 | ||
3860 | btrfs_init_map_token(&token); | |
be0e5c09 | 3861 | |
5f39d397 | 3862 | leaf = path->nodes[0]; |
85e21bac CM |
3863 | last_off = btrfs_item_offset_nr(leaf, slot + nr - 1); |
3864 | ||
3865 | for (i = 0; i < nr; i++) | |
3866 | dsize += btrfs_item_size_nr(leaf, slot + i); | |
3867 | ||
5f39d397 | 3868 | nritems = btrfs_header_nritems(leaf); |
be0e5c09 | 3869 | |
85e21bac | 3870 | if (slot + nr != nritems) { |
123abc88 | 3871 | int data_end = leaf_data_end(root, leaf); |
5f39d397 CM |
3872 | |
3873 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + | |
d6025579 CM |
3874 | data_end + dsize, |
3875 | btrfs_leaf_data(leaf) + data_end, | |
85e21bac | 3876 | last_off - data_end); |
5f39d397 | 3877 | |
85e21bac | 3878 | for (i = slot + nr; i < nritems; i++) { |
5f39d397 | 3879 | u32 ioff; |
db94535d | 3880 | |
5f39d397 | 3881 | item = btrfs_item_nr(leaf, i); |
cfed81a0 CM |
3882 | ioff = btrfs_token_item_offset(leaf, item, &token); |
3883 | btrfs_set_token_item_offset(leaf, item, | |
3884 | ioff + dsize, &token); | |
0783fcfc | 3885 | } |
db94535d | 3886 | |
5f39d397 | 3887 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot), |
85e21bac | 3888 | btrfs_item_nr_offset(slot + nr), |
d6025579 | 3889 | sizeof(struct btrfs_item) * |
85e21bac | 3890 | (nritems - slot - nr)); |
be0e5c09 | 3891 | } |
85e21bac CM |
3892 | btrfs_set_header_nritems(leaf, nritems - nr); |
3893 | nritems -= nr; | |
5f39d397 | 3894 | |
74123bd7 | 3895 | /* delete the leaf if we've emptied it */ |
7518a238 | 3896 | if (nritems == 0) { |
5f39d397 CM |
3897 | if (leaf == root->node) { |
3898 | btrfs_set_header_level(leaf, 0); | |
9a8dd150 | 3899 | } else { |
f0486c68 YZ |
3900 | btrfs_set_path_blocking(path); |
3901 | clean_tree_block(trans, root, leaf); | |
5d4f98a2 | 3902 | ret = btrfs_del_leaf(trans, root, path, leaf); |
323ac95b | 3903 | BUG_ON(ret); |
9a8dd150 | 3904 | } |
be0e5c09 | 3905 | } else { |
7518a238 | 3906 | int used = leaf_space_used(leaf, 0, nritems); |
aa5d6bed | 3907 | if (slot == 0) { |
5f39d397 CM |
3908 | struct btrfs_disk_key disk_key; |
3909 | ||
3910 | btrfs_item_key(leaf, &disk_key, 0); | |
e089f05c | 3911 | wret = fixup_low_keys(trans, root, path, |
5f39d397 | 3912 | &disk_key, 1); |
aa5d6bed CM |
3913 | if (wret) |
3914 | ret = wret; | |
3915 | } | |
aa5d6bed | 3916 | |
74123bd7 | 3917 | /* delete the leaf if it is mostly empty */ |
d717aa1d | 3918 | if (used < BTRFS_LEAF_DATA_SIZE(root) / 3) { |
be0e5c09 CM |
3919 | /* push_leaf_left fixes the path. |
3920 | * make sure the path still points to our leaf | |
3921 | * for possible call to del_ptr below | |
3922 | */ | |
4920c9ac | 3923 | slot = path->slots[1]; |
5f39d397 CM |
3924 | extent_buffer_get(leaf); |
3925 | ||
b9473439 | 3926 | btrfs_set_path_blocking(path); |
99d8f83c CM |
3927 | wret = push_leaf_left(trans, root, path, 1, 1, |
3928 | 1, (u32)-1); | |
54aa1f4d | 3929 | if (wret < 0 && wret != -ENOSPC) |
aa5d6bed | 3930 | ret = wret; |
5f39d397 CM |
3931 | |
3932 | if (path->nodes[0] == leaf && | |
3933 | btrfs_header_nritems(leaf)) { | |
99d8f83c CM |
3934 | wret = push_leaf_right(trans, root, path, 1, |
3935 | 1, 1, 0); | |
54aa1f4d | 3936 | if (wret < 0 && wret != -ENOSPC) |
aa5d6bed CM |
3937 | ret = wret; |
3938 | } | |
5f39d397 CM |
3939 | |
3940 | if (btrfs_header_nritems(leaf) == 0) { | |
323ac95b | 3941 | path->slots[1] = slot; |
5d4f98a2 | 3942 | ret = btrfs_del_leaf(trans, root, path, leaf); |
323ac95b | 3943 | BUG_ON(ret); |
5f39d397 | 3944 | free_extent_buffer(leaf); |
5de08d7d | 3945 | } else { |
925baedd CM |
3946 | /* if we're still in the path, make sure |
3947 | * we're dirty. Otherwise, one of the | |
3948 | * push_leaf functions must have already | |
3949 | * dirtied this buffer | |
3950 | */ | |
3951 | if (path->nodes[0] == leaf) | |
3952 | btrfs_mark_buffer_dirty(leaf); | |
5f39d397 | 3953 | free_extent_buffer(leaf); |
be0e5c09 | 3954 | } |
d5719762 | 3955 | } else { |
5f39d397 | 3956 | btrfs_mark_buffer_dirty(leaf); |
be0e5c09 CM |
3957 | } |
3958 | } | |
aa5d6bed | 3959 | return ret; |
be0e5c09 CM |
3960 | } |
3961 | ||
7bb86316 | 3962 | /* |
925baedd | 3963 | * search the tree again to find a leaf with lesser keys |
7bb86316 CM |
3964 | * returns 0 if it found something or 1 if there are no lesser leaves. |
3965 | * returns < 0 on io errors. | |
d352ac68 CM |
3966 | * |
3967 | * This may release the path, and so you may lose any locks held at the | |
3968 | * time you call it. | |
7bb86316 CM |
3969 | */ |
3970 | int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path) | |
3971 | { | |
925baedd CM |
3972 | struct btrfs_key key; |
3973 | struct btrfs_disk_key found_key; | |
3974 | int ret; | |
7bb86316 | 3975 | |
925baedd | 3976 | btrfs_item_key_to_cpu(path->nodes[0], &key, 0); |
7bb86316 | 3977 | |
925baedd CM |
3978 | if (key.offset > 0) |
3979 | key.offset--; | |
3980 | else if (key.type > 0) | |
3981 | key.type--; | |
3982 | else if (key.objectid > 0) | |
3983 | key.objectid--; | |
3984 | else | |
3985 | return 1; | |
7bb86316 | 3986 | |
b3b4aa74 | 3987 | btrfs_release_path(path); |
925baedd CM |
3988 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
3989 | if (ret < 0) | |
3990 | return ret; | |
3991 | btrfs_item_key(path->nodes[0], &found_key, 0); | |
3992 | ret = comp_keys(&found_key, &key); | |
3993 | if (ret < 0) | |
3994 | return 0; | |
3995 | return 1; | |
7bb86316 CM |
3996 | } |
3997 | ||
3f157a2f CM |
3998 | /* |
3999 | * A helper function to walk down the tree starting at min_key, and looking | |
4000 | * for nodes or leaves that are either in cache or have a minimum | |
d352ac68 | 4001 | * transaction id. This is used by the btree defrag code, and tree logging |
3f157a2f CM |
4002 | * |
4003 | * This does not cow, but it does stuff the starting key it finds back | |
4004 | * into min_key, so you can call btrfs_search_slot with cow=1 on the | |
4005 | * key and get a writable path. | |
4006 | * | |
4007 | * This does lock as it descends, and path->keep_locks should be set | |
4008 | * to 1 by the caller. | |
4009 | * | |
4010 | * This honors path->lowest_level to prevent descent past a given level | |
4011 | * of the tree. | |
4012 | * | |
d352ac68 CM |
4013 | * min_trans indicates the oldest transaction that you are interested |
4014 | * in walking through. Any nodes or leaves older than min_trans are | |
4015 | * skipped over (without reading them). | |
4016 | * | |
3f157a2f CM |
4017 | * returns zero if something useful was found, < 0 on error and 1 if there |
4018 | * was nothing in the tree that matched the search criteria. | |
4019 | */ | |
4020 | int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key, | |
e02119d5 | 4021 | struct btrfs_key *max_key, |
3f157a2f CM |
4022 | struct btrfs_path *path, int cache_only, |
4023 | u64 min_trans) | |
4024 | { | |
4025 | struct extent_buffer *cur; | |
4026 | struct btrfs_key found_key; | |
4027 | int slot; | |
9652480b | 4028 | int sret; |
3f157a2f CM |
4029 | u32 nritems; |
4030 | int level; | |
4031 | int ret = 1; | |
4032 | ||
934d375b | 4033 | WARN_ON(!path->keep_locks); |
3f157a2f | 4034 | again: |
bd681513 | 4035 | cur = btrfs_read_lock_root_node(root); |
3f157a2f | 4036 | level = btrfs_header_level(cur); |
e02119d5 | 4037 | WARN_ON(path->nodes[level]); |
3f157a2f | 4038 | path->nodes[level] = cur; |
bd681513 | 4039 | path->locks[level] = BTRFS_READ_LOCK; |
3f157a2f CM |
4040 | |
4041 | if (btrfs_header_generation(cur) < min_trans) { | |
4042 | ret = 1; | |
4043 | goto out; | |
4044 | } | |
d397712b | 4045 | while (1) { |
3f157a2f CM |
4046 | nritems = btrfs_header_nritems(cur); |
4047 | level = btrfs_header_level(cur); | |
9652480b | 4048 | sret = bin_search(cur, min_key, level, &slot); |
3f157a2f | 4049 | |
323ac95b CM |
4050 | /* at the lowest level, we're done, setup the path and exit */ |
4051 | if (level == path->lowest_level) { | |
e02119d5 CM |
4052 | if (slot >= nritems) |
4053 | goto find_next_key; | |
3f157a2f CM |
4054 | ret = 0; |
4055 | path->slots[level] = slot; | |
4056 | btrfs_item_key_to_cpu(cur, &found_key, slot); | |
4057 | goto out; | |
4058 | } | |
9652480b Y |
4059 | if (sret && slot > 0) |
4060 | slot--; | |
3f157a2f CM |
4061 | /* |
4062 | * check this node pointer against the cache_only and | |
4063 | * min_trans parameters. If it isn't in cache or is too | |
4064 | * old, skip to the next one. | |
4065 | */ | |
d397712b | 4066 | while (slot < nritems) { |
3f157a2f CM |
4067 | u64 blockptr; |
4068 | u64 gen; | |
4069 | struct extent_buffer *tmp; | |
e02119d5 CM |
4070 | struct btrfs_disk_key disk_key; |
4071 | ||
3f157a2f CM |
4072 | blockptr = btrfs_node_blockptr(cur, slot); |
4073 | gen = btrfs_node_ptr_generation(cur, slot); | |
4074 | if (gen < min_trans) { | |
4075 | slot++; | |
4076 | continue; | |
4077 | } | |
4078 | if (!cache_only) | |
4079 | break; | |
4080 | ||
e02119d5 CM |
4081 | if (max_key) { |
4082 | btrfs_node_key(cur, &disk_key, slot); | |
4083 | if (comp_keys(&disk_key, max_key) >= 0) { | |
4084 | ret = 1; | |
4085 | goto out; | |
4086 | } | |
4087 | } | |
4088 | ||
3f157a2f CM |
4089 | tmp = btrfs_find_tree_block(root, blockptr, |
4090 | btrfs_level_size(root, level - 1)); | |
4091 | ||
4092 | if (tmp && btrfs_buffer_uptodate(tmp, gen)) { | |
4093 | free_extent_buffer(tmp); | |
4094 | break; | |
4095 | } | |
4096 | if (tmp) | |
4097 | free_extent_buffer(tmp); | |
4098 | slot++; | |
4099 | } | |
e02119d5 | 4100 | find_next_key: |
3f157a2f CM |
4101 | /* |
4102 | * we didn't find a candidate key in this node, walk forward | |
4103 | * and find another one | |
4104 | */ | |
4105 | if (slot >= nritems) { | |
e02119d5 | 4106 | path->slots[level] = slot; |
b4ce94de | 4107 | btrfs_set_path_blocking(path); |
e02119d5 | 4108 | sret = btrfs_find_next_key(root, path, min_key, level, |
3f157a2f | 4109 | cache_only, min_trans); |
e02119d5 | 4110 | if (sret == 0) { |
b3b4aa74 | 4111 | btrfs_release_path(path); |
3f157a2f CM |
4112 | goto again; |
4113 | } else { | |
4114 | goto out; | |
4115 | } | |
4116 | } | |
4117 | /* save our key for returning back */ | |
4118 | btrfs_node_key_to_cpu(cur, &found_key, slot); | |
4119 | path->slots[level] = slot; | |
4120 | if (level == path->lowest_level) { | |
4121 | ret = 0; | |
f7c79f30 | 4122 | unlock_up(path, level, 1, 0, NULL); |
3f157a2f CM |
4123 | goto out; |
4124 | } | |
b4ce94de | 4125 | btrfs_set_path_blocking(path); |
3f157a2f | 4126 | cur = read_node_slot(root, cur, slot); |
97d9a8a4 | 4127 | BUG_ON(!cur); |
3f157a2f | 4128 | |
bd681513 | 4129 | btrfs_tree_read_lock(cur); |
b4ce94de | 4130 | |
bd681513 | 4131 | path->locks[level - 1] = BTRFS_READ_LOCK; |
3f157a2f | 4132 | path->nodes[level - 1] = cur; |
f7c79f30 | 4133 | unlock_up(path, level, 1, 0, NULL); |
bd681513 | 4134 | btrfs_clear_path_blocking(path, NULL, 0); |
3f157a2f CM |
4135 | } |
4136 | out: | |
4137 | if (ret == 0) | |
4138 | memcpy(min_key, &found_key, sizeof(found_key)); | |
b4ce94de | 4139 | btrfs_set_path_blocking(path); |
3f157a2f CM |
4140 | return ret; |
4141 | } | |
4142 | ||
4143 | /* | |
4144 | * this is similar to btrfs_next_leaf, but does not try to preserve | |
4145 | * and fixup the path. It looks for and returns the next key in the | |
4146 | * tree based on the current path and the cache_only and min_trans | |
4147 | * parameters. | |
4148 | * | |
4149 | * 0 is returned if another key is found, < 0 if there are any errors | |
4150 | * and 1 is returned if there are no higher keys in the tree | |
4151 | * | |
4152 | * path->keep_locks should be set to 1 on the search made before | |
4153 | * calling this function. | |
4154 | */ | |
e7a84565 | 4155 | int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path, |
33c66f43 | 4156 | struct btrfs_key *key, int level, |
3f157a2f | 4157 | int cache_only, u64 min_trans) |
e7a84565 | 4158 | { |
e7a84565 CM |
4159 | int slot; |
4160 | struct extent_buffer *c; | |
4161 | ||
934d375b | 4162 | WARN_ON(!path->keep_locks); |
d397712b | 4163 | while (level < BTRFS_MAX_LEVEL) { |
e7a84565 CM |
4164 | if (!path->nodes[level]) |
4165 | return 1; | |
4166 | ||
4167 | slot = path->slots[level] + 1; | |
4168 | c = path->nodes[level]; | |
3f157a2f | 4169 | next: |
e7a84565 | 4170 | if (slot >= btrfs_header_nritems(c)) { |
33c66f43 YZ |
4171 | int ret; |
4172 | int orig_lowest; | |
4173 | struct btrfs_key cur_key; | |
4174 | if (level + 1 >= BTRFS_MAX_LEVEL || | |
4175 | !path->nodes[level + 1]) | |
e7a84565 | 4176 | return 1; |
33c66f43 YZ |
4177 | |
4178 | if (path->locks[level + 1]) { | |
4179 | level++; | |
4180 | continue; | |
4181 | } | |
4182 | ||
4183 | slot = btrfs_header_nritems(c) - 1; | |
4184 | if (level == 0) | |
4185 | btrfs_item_key_to_cpu(c, &cur_key, slot); | |
4186 | else | |
4187 | btrfs_node_key_to_cpu(c, &cur_key, slot); | |
4188 | ||
4189 | orig_lowest = path->lowest_level; | |
b3b4aa74 | 4190 | btrfs_release_path(path); |
33c66f43 YZ |
4191 | path->lowest_level = level; |
4192 | ret = btrfs_search_slot(NULL, root, &cur_key, path, | |
4193 | 0, 0); | |
4194 | path->lowest_level = orig_lowest; | |
4195 | if (ret < 0) | |
4196 | return ret; | |
4197 | ||
4198 | c = path->nodes[level]; | |
4199 | slot = path->slots[level]; | |
4200 | if (ret == 0) | |
4201 | slot++; | |
4202 | goto next; | |
e7a84565 | 4203 | } |
33c66f43 | 4204 | |
e7a84565 CM |
4205 | if (level == 0) |
4206 | btrfs_item_key_to_cpu(c, key, slot); | |
3f157a2f CM |
4207 | else { |
4208 | u64 blockptr = btrfs_node_blockptr(c, slot); | |
4209 | u64 gen = btrfs_node_ptr_generation(c, slot); | |
4210 | ||
4211 | if (cache_only) { | |
4212 | struct extent_buffer *cur; | |
4213 | cur = btrfs_find_tree_block(root, blockptr, | |
4214 | btrfs_level_size(root, level - 1)); | |
4215 | if (!cur || !btrfs_buffer_uptodate(cur, gen)) { | |
4216 | slot++; | |
4217 | if (cur) | |
4218 | free_extent_buffer(cur); | |
4219 | goto next; | |
4220 | } | |
4221 | free_extent_buffer(cur); | |
4222 | } | |
4223 | if (gen < min_trans) { | |
4224 | slot++; | |
4225 | goto next; | |
4226 | } | |
e7a84565 | 4227 | btrfs_node_key_to_cpu(c, key, slot); |
3f157a2f | 4228 | } |
e7a84565 CM |
4229 | return 0; |
4230 | } | |
4231 | return 1; | |
4232 | } | |
4233 | ||
97571fd0 | 4234 | /* |
925baedd | 4235 | * search the tree again to find a leaf with greater keys |
0f70abe2 CM |
4236 | * returns 0 if it found something or 1 if there are no greater leaves. |
4237 | * returns < 0 on io errors. | |
97571fd0 | 4238 | */ |
234b63a0 | 4239 | int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path) |
d97e63b6 CM |
4240 | { |
4241 | int slot; | |
8e73f275 | 4242 | int level; |
5f39d397 | 4243 | struct extent_buffer *c; |
8e73f275 | 4244 | struct extent_buffer *next; |
925baedd CM |
4245 | struct btrfs_key key; |
4246 | u32 nritems; | |
4247 | int ret; | |
8e73f275 | 4248 | int old_spinning = path->leave_spinning; |
bd681513 | 4249 | int next_rw_lock = 0; |
925baedd CM |
4250 | |
4251 | nritems = btrfs_header_nritems(path->nodes[0]); | |
d397712b | 4252 | if (nritems == 0) |
925baedd | 4253 | return 1; |
925baedd | 4254 | |
8e73f275 CM |
4255 | btrfs_item_key_to_cpu(path->nodes[0], &key, nritems - 1); |
4256 | again: | |
4257 | level = 1; | |
4258 | next = NULL; | |
bd681513 | 4259 | next_rw_lock = 0; |
b3b4aa74 | 4260 | btrfs_release_path(path); |
8e73f275 | 4261 | |
a2135011 | 4262 | path->keep_locks = 1; |
31533fb2 | 4263 | path->leave_spinning = 1; |
8e73f275 | 4264 | |
925baedd CM |
4265 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
4266 | path->keep_locks = 0; | |
4267 | ||
4268 | if (ret < 0) | |
4269 | return ret; | |
4270 | ||
a2135011 | 4271 | nritems = btrfs_header_nritems(path->nodes[0]); |
168fd7d2 CM |
4272 | /* |
4273 | * by releasing the path above we dropped all our locks. A balance | |
4274 | * could have added more items next to the key that used to be | |
4275 | * at the very end of the block. So, check again here and | |
4276 | * advance the path if there are now more items available. | |
4277 | */ | |
a2135011 | 4278 | if (nritems > 0 && path->slots[0] < nritems - 1) { |
e457afec YZ |
4279 | if (ret == 0) |
4280 | path->slots[0]++; | |
8e73f275 | 4281 | ret = 0; |
925baedd CM |
4282 | goto done; |
4283 | } | |
d97e63b6 | 4284 | |
d397712b | 4285 | while (level < BTRFS_MAX_LEVEL) { |
8e73f275 CM |
4286 | if (!path->nodes[level]) { |
4287 | ret = 1; | |
4288 | goto done; | |
4289 | } | |
5f39d397 | 4290 | |
d97e63b6 CM |
4291 | slot = path->slots[level] + 1; |
4292 | c = path->nodes[level]; | |
5f39d397 | 4293 | if (slot >= btrfs_header_nritems(c)) { |
d97e63b6 | 4294 | level++; |
8e73f275 CM |
4295 | if (level == BTRFS_MAX_LEVEL) { |
4296 | ret = 1; | |
4297 | goto done; | |
4298 | } | |
d97e63b6 CM |
4299 | continue; |
4300 | } | |
5f39d397 | 4301 | |
925baedd | 4302 | if (next) { |
bd681513 | 4303 | btrfs_tree_unlock_rw(next, next_rw_lock); |
5f39d397 | 4304 | free_extent_buffer(next); |
925baedd | 4305 | } |
5f39d397 | 4306 | |
8e73f275 | 4307 | next = c; |
bd681513 | 4308 | next_rw_lock = path->locks[level]; |
8e73f275 CM |
4309 | ret = read_block_for_search(NULL, root, path, &next, level, |
4310 | slot, &key); | |
4311 | if (ret == -EAGAIN) | |
4312 | goto again; | |
5f39d397 | 4313 | |
76a05b35 | 4314 | if (ret < 0) { |
b3b4aa74 | 4315 | btrfs_release_path(path); |
76a05b35 CM |
4316 | goto done; |
4317 | } | |
4318 | ||
5cd57b2c | 4319 | if (!path->skip_locking) { |
bd681513 | 4320 | ret = btrfs_try_tree_read_lock(next); |
8e73f275 CM |
4321 | if (!ret) { |
4322 | btrfs_set_path_blocking(path); | |
bd681513 | 4323 | btrfs_tree_read_lock(next); |
31533fb2 | 4324 | btrfs_clear_path_blocking(path, next, |
bd681513 | 4325 | BTRFS_READ_LOCK); |
8e73f275 | 4326 | } |
31533fb2 | 4327 | next_rw_lock = BTRFS_READ_LOCK; |
5cd57b2c | 4328 | } |
d97e63b6 CM |
4329 | break; |
4330 | } | |
4331 | path->slots[level] = slot; | |
d397712b | 4332 | while (1) { |
d97e63b6 CM |
4333 | level--; |
4334 | c = path->nodes[level]; | |
925baedd | 4335 | if (path->locks[level]) |
bd681513 | 4336 | btrfs_tree_unlock_rw(c, path->locks[level]); |
8e73f275 | 4337 | |
5f39d397 | 4338 | free_extent_buffer(c); |
d97e63b6 CM |
4339 | path->nodes[level] = next; |
4340 | path->slots[level] = 0; | |
a74a4b97 | 4341 | if (!path->skip_locking) |
bd681513 | 4342 | path->locks[level] = next_rw_lock; |
d97e63b6 CM |
4343 | if (!level) |
4344 | break; | |
b4ce94de | 4345 | |
8e73f275 CM |
4346 | ret = read_block_for_search(NULL, root, path, &next, level, |
4347 | 0, &key); | |
4348 | if (ret == -EAGAIN) | |
4349 | goto again; | |
4350 | ||
76a05b35 | 4351 | if (ret < 0) { |
b3b4aa74 | 4352 | btrfs_release_path(path); |
76a05b35 CM |
4353 | goto done; |
4354 | } | |
4355 | ||
5cd57b2c | 4356 | if (!path->skip_locking) { |
bd681513 | 4357 | ret = btrfs_try_tree_read_lock(next); |
8e73f275 CM |
4358 | if (!ret) { |
4359 | btrfs_set_path_blocking(path); | |
bd681513 | 4360 | btrfs_tree_read_lock(next); |
31533fb2 | 4361 | btrfs_clear_path_blocking(path, next, |
bd681513 CM |
4362 | BTRFS_READ_LOCK); |
4363 | } | |
31533fb2 | 4364 | next_rw_lock = BTRFS_READ_LOCK; |
5cd57b2c | 4365 | } |
d97e63b6 | 4366 | } |
8e73f275 | 4367 | ret = 0; |
925baedd | 4368 | done: |
f7c79f30 | 4369 | unlock_up(path, 0, 1, 0, NULL); |
8e73f275 CM |
4370 | path->leave_spinning = old_spinning; |
4371 | if (!old_spinning) | |
4372 | btrfs_set_path_blocking(path); | |
4373 | ||
4374 | return ret; | |
d97e63b6 | 4375 | } |
0b86a832 | 4376 | |
3f157a2f CM |
4377 | /* |
4378 | * this uses btrfs_prev_leaf to walk backwards in the tree, and keeps | |
4379 | * searching until it gets past min_objectid or finds an item of 'type' | |
4380 | * | |
4381 | * returns 0 if something is found, 1 if nothing was found and < 0 on error | |
4382 | */ | |
0b86a832 CM |
4383 | int btrfs_previous_item(struct btrfs_root *root, |
4384 | struct btrfs_path *path, u64 min_objectid, | |
4385 | int type) | |
4386 | { | |
4387 | struct btrfs_key found_key; | |
4388 | struct extent_buffer *leaf; | |
e02119d5 | 4389 | u32 nritems; |
0b86a832 CM |
4390 | int ret; |
4391 | ||
d397712b | 4392 | while (1) { |
0b86a832 | 4393 | if (path->slots[0] == 0) { |
b4ce94de | 4394 | btrfs_set_path_blocking(path); |
0b86a832 CM |
4395 | ret = btrfs_prev_leaf(root, path); |
4396 | if (ret != 0) | |
4397 | return ret; | |
4398 | } else { | |
4399 | path->slots[0]--; | |
4400 | } | |
4401 | leaf = path->nodes[0]; | |
e02119d5 CM |
4402 | nritems = btrfs_header_nritems(leaf); |
4403 | if (nritems == 0) | |
4404 | return 1; | |
4405 | if (path->slots[0] == nritems) | |
4406 | path->slots[0]--; | |
4407 | ||
0b86a832 | 4408 | btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); |
e02119d5 CM |
4409 | if (found_key.objectid < min_objectid) |
4410 | break; | |
0a4eefbb YZ |
4411 | if (found_key.type == type) |
4412 | return 0; | |
e02119d5 CM |
4413 | if (found_key.objectid == min_objectid && |
4414 | found_key.type < type) | |
4415 | break; | |
0b86a832 CM |
4416 | } |
4417 | return 1; | |
4418 | } |