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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> |
bd989ba3 | 21 | #include <linux/rbtree.h> |
eb60ceac CM |
22 | #include "ctree.h" |
23 | #include "disk-io.h" | |
7f5c1516 | 24 | #include "transaction.h" |
5f39d397 | 25 | #include "print-tree.h" |
925baedd | 26 | #include "locking.h" |
9a8dd150 | 27 | |
e089f05c CM |
28 | static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root |
29 | *root, struct btrfs_path *path, int level); | |
30 | static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root | |
d4dbff95 | 31 | *root, struct btrfs_key *ins_key, |
cc0c5538 | 32 | struct btrfs_path *path, int data_size, int extend); |
5f39d397 CM |
33 | static int push_node_left(struct btrfs_trans_handle *trans, |
34 | struct btrfs_root *root, struct extent_buffer *dst, | |
971a1f66 | 35 | struct extent_buffer *src, int empty); |
5f39d397 CM |
36 | static int balance_node_right(struct btrfs_trans_handle *trans, |
37 | struct btrfs_root *root, | |
38 | struct extent_buffer *dst_buf, | |
39 | struct extent_buffer *src_buf); | |
143bede5 | 40 | static void del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
0e411ece | 41 | struct btrfs_path *path, int level, int slot); |
f230475e JS |
42 | static void tree_mod_log_free_eb(struct btrfs_fs_info *fs_info, |
43 | struct extent_buffer *eb); | |
44 | struct extent_buffer *read_old_tree_block(struct btrfs_root *root, u64 bytenr, | |
45 | u32 blocksize, u64 parent_transid, | |
46 | u64 time_seq); | |
47 | struct extent_buffer *btrfs_find_old_tree_block(struct btrfs_root *root, | |
48 | u64 bytenr, u32 blocksize, | |
49 | u64 time_seq); | |
d97e63b6 | 50 | |
df24a2b9 | 51 | struct btrfs_path *btrfs_alloc_path(void) |
2c90e5d6 | 52 | { |
df24a2b9 | 53 | struct btrfs_path *path; |
e00f7308 | 54 | path = kmem_cache_zalloc(btrfs_path_cachep, GFP_NOFS); |
df24a2b9 | 55 | return path; |
2c90e5d6 CM |
56 | } |
57 | ||
b4ce94de CM |
58 | /* |
59 | * set all locked nodes in the path to blocking locks. This should | |
60 | * be done before scheduling | |
61 | */ | |
62 | noinline void btrfs_set_path_blocking(struct btrfs_path *p) | |
63 | { | |
64 | int i; | |
65 | for (i = 0; i < BTRFS_MAX_LEVEL; i++) { | |
bd681513 CM |
66 | if (!p->nodes[i] || !p->locks[i]) |
67 | continue; | |
68 | btrfs_set_lock_blocking_rw(p->nodes[i], p->locks[i]); | |
69 | if (p->locks[i] == BTRFS_READ_LOCK) | |
70 | p->locks[i] = BTRFS_READ_LOCK_BLOCKING; | |
71 | else if (p->locks[i] == BTRFS_WRITE_LOCK) | |
72 | p->locks[i] = BTRFS_WRITE_LOCK_BLOCKING; | |
b4ce94de CM |
73 | } |
74 | } | |
75 | ||
76 | /* | |
77 | * reset all the locked nodes in the patch to spinning locks. | |
4008c04a CM |
78 | * |
79 | * held is used to keep lockdep happy, when lockdep is enabled | |
80 | * we set held to a blocking lock before we go around and | |
81 | * retake all the spinlocks in the path. You can safely use NULL | |
82 | * for held | |
b4ce94de | 83 | */ |
4008c04a | 84 | noinline void btrfs_clear_path_blocking(struct btrfs_path *p, |
bd681513 | 85 | struct extent_buffer *held, int held_rw) |
b4ce94de CM |
86 | { |
87 | int i; | |
4008c04a CM |
88 | |
89 | #ifdef CONFIG_DEBUG_LOCK_ALLOC | |
90 | /* lockdep really cares that we take all of these spinlocks | |
91 | * in the right order. If any of the locks in the path are not | |
92 | * currently blocking, it is going to complain. So, make really | |
93 | * really sure by forcing the path to blocking before we clear | |
94 | * the path blocking. | |
95 | */ | |
bd681513 CM |
96 | if (held) { |
97 | btrfs_set_lock_blocking_rw(held, held_rw); | |
98 | if (held_rw == BTRFS_WRITE_LOCK) | |
99 | held_rw = BTRFS_WRITE_LOCK_BLOCKING; | |
100 | else if (held_rw == BTRFS_READ_LOCK) | |
101 | held_rw = BTRFS_READ_LOCK_BLOCKING; | |
102 | } | |
4008c04a CM |
103 | btrfs_set_path_blocking(p); |
104 | #endif | |
105 | ||
106 | for (i = BTRFS_MAX_LEVEL - 1; i >= 0; i--) { | |
bd681513 CM |
107 | if (p->nodes[i] && p->locks[i]) { |
108 | btrfs_clear_lock_blocking_rw(p->nodes[i], p->locks[i]); | |
109 | if (p->locks[i] == BTRFS_WRITE_LOCK_BLOCKING) | |
110 | p->locks[i] = BTRFS_WRITE_LOCK; | |
111 | else if (p->locks[i] == BTRFS_READ_LOCK_BLOCKING) | |
112 | p->locks[i] = BTRFS_READ_LOCK; | |
113 | } | |
b4ce94de | 114 | } |
4008c04a CM |
115 | |
116 | #ifdef CONFIG_DEBUG_LOCK_ALLOC | |
117 | if (held) | |
bd681513 | 118 | btrfs_clear_lock_blocking_rw(held, held_rw); |
4008c04a | 119 | #endif |
b4ce94de CM |
120 | } |
121 | ||
d352ac68 | 122 | /* this also releases the path */ |
df24a2b9 | 123 | void btrfs_free_path(struct btrfs_path *p) |
be0e5c09 | 124 | { |
ff175d57 JJ |
125 | if (!p) |
126 | return; | |
b3b4aa74 | 127 | btrfs_release_path(p); |
df24a2b9 | 128 | kmem_cache_free(btrfs_path_cachep, p); |
be0e5c09 CM |
129 | } |
130 | ||
d352ac68 CM |
131 | /* |
132 | * path release drops references on the extent buffers in the path | |
133 | * and it drops any locks held by this path | |
134 | * | |
135 | * It is safe to call this on paths that no locks or extent buffers held. | |
136 | */ | |
b3b4aa74 | 137 | noinline void btrfs_release_path(struct btrfs_path *p) |
eb60ceac CM |
138 | { |
139 | int i; | |
a2135011 | 140 | |
234b63a0 | 141 | for (i = 0; i < BTRFS_MAX_LEVEL; i++) { |
3f157a2f | 142 | p->slots[i] = 0; |
eb60ceac | 143 | if (!p->nodes[i]) |
925baedd CM |
144 | continue; |
145 | if (p->locks[i]) { | |
bd681513 | 146 | btrfs_tree_unlock_rw(p->nodes[i], p->locks[i]); |
925baedd CM |
147 | p->locks[i] = 0; |
148 | } | |
5f39d397 | 149 | free_extent_buffer(p->nodes[i]); |
3f157a2f | 150 | p->nodes[i] = NULL; |
eb60ceac CM |
151 | } |
152 | } | |
153 | ||
d352ac68 CM |
154 | /* |
155 | * safely gets a reference on the root node of a tree. A lock | |
156 | * is not taken, so a concurrent writer may put a different node | |
157 | * at the root of the tree. See btrfs_lock_root_node for the | |
158 | * looping required. | |
159 | * | |
160 | * The extent buffer returned by this has a reference taken, so | |
161 | * it won't disappear. It may stop being the root of the tree | |
162 | * at any time because there are no locks held. | |
163 | */ | |
925baedd CM |
164 | struct extent_buffer *btrfs_root_node(struct btrfs_root *root) |
165 | { | |
166 | struct extent_buffer *eb; | |
240f62c8 | 167 | |
3083ee2e JB |
168 | while (1) { |
169 | rcu_read_lock(); | |
170 | eb = rcu_dereference(root->node); | |
171 | ||
172 | /* | |
173 | * RCU really hurts here, we could free up the root node because | |
174 | * it was cow'ed but we may not get the new root node yet so do | |
175 | * the inc_not_zero dance and if it doesn't work then | |
176 | * synchronize_rcu and try again. | |
177 | */ | |
178 | if (atomic_inc_not_zero(&eb->refs)) { | |
179 | rcu_read_unlock(); | |
180 | break; | |
181 | } | |
182 | rcu_read_unlock(); | |
183 | synchronize_rcu(); | |
184 | } | |
925baedd CM |
185 | return eb; |
186 | } | |
187 | ||
d352ac68 CM |
188 | /* loop around taking references on and locking the root node of the |
189 | * tree until you end up with a lock on the root. A locked buffer | |
190 | * is returned, with a reference held. | |
191 | */ | |
925baedd CM |
192 | struct extent_buffer *btrfs_lock_root_node(struct btrfs_root *root) |
193 | { | |
194 | struct extent_buffer *eb; | |
195 | ||
d397712b | 196 | while (1) { |
925baedd CM |
197 | eb = btrfs_root_node(root); |
198 | btrfs_tree_lock(eb); | |
240f62c8 | 199 | if (eb == root->node) |
925baedd | 200 | break; |
925baedd CM |
201 | btrfs_tree_unlock(eb); |
202 | free_extent_buffer(eb); | |
203 | } | |
204 | return eb; | |
205 | } | |
206 | ||
bd681513 CM |
207 | /* loop around taking references on and locking the root node of the |
208 | * tree until you end up with a lock on the root. A locked buffer | |
209 | * is returned, with a reference held. | |
210 | */ | |
211 | struct extent_buffer *btrfs_read_lock_root_node(struct btrfs_root *root) | |
212 | { | |
213 | struct extent_buffer *eb; | |
214 | ||
215 | while (1) { | |
216 | eb = btrfs_root_node(root); | |
217 | btrfs_tree_read_lock(eb); | |
218 | if (eb == root->node) | |
219 | break; | |
220 | btrfs_tree_read_unlock(eb); | |
221 | free_extent_buffer(eb); | |
222 | } | |
223 | return eb; | |
224 | } | |
225 | ||
d352ac68 CM |
226 | /* cowonly root (everything not a reference counted cow subvolume), just get |
227 | * put onto a simple dirty list. transaction.c walks this to make sure they | |
228 | * get properly updated on disk. | |
229 | */ | |
0b86a832 CM |
230 | static void add_root_to_dirty_list(struct btrfs_root *root) |
231 | { | |
e5846fc6 | 232 | spin_lock(&root->fs_info->trans_lock); |
0b86a832 CM |
233 | if (root->track_dirty && list_empty(&root->dirty_list)) { |
234 | list_add(&root->dirty_list, | |
235 | &root->fs_info->dirty_cowonly_roots); | |
236 | } | |
e5846fc6 | 237 | spin_unlock(&root->fs_info->trans_lock); |
0b86a832 CM |
238 | } |
239 | ||
d352ac68 CM |
240 | /* |
241 | * used by snapshot creation to make a copy of a root for a tree with | |
242 | * a given objectid. The buffer with the new root node is returned in | |
243 | * cow_ret, and this func returns zero on success or a negative error code. | |
244 | */ | |
be20aa9d CM |
245 | int btrfs_copy_root(struct btrfs_trans_handle *trans, |
246 | struct btrfs_root *root, | |
247 | struct extent_buffer *buf, | |
248 | struct extent_buffer **cow_ret, u64 new_root_objectid) | |
249 | { | |
250 | struct extent_buffer *cow; | |
be20aa9d CM |
251 | int ret = 0; |
252 | int level; | |
5d4f98a2 | 253 | struct btrfs_disk_key disk_key; |
be20aa9d CM |
254 | |
255 | WARN_ON(root->ref_cows && trans->transid != | |
256 | root->fs_info->running_transaction->transid); | |
257 | WARN_ON(root->ref_cows && trans->transid != root->last_trans); | |
258 | ||
259 | level = btrfs_header_level(buf); | |
5d4f98a2 YZ |
260 | if (level == 0) |
261 | btrfs_item_key(buf, &disk_key, 0); | |
262 | else | |
263 | btrfs_node_key(buf, &disk_key, 0); | |
31840ae1 | 264 | |
5d4f98a2 YZ |
265 | cow = btrfs_alloc_free_block(trans, root, buf->len, 0, |
266 | new_root_objectid, &disk_key, level, | |
5581a51a | 267 | buf->start, 0); |
5d4f98a2 | 268 | if (IS_ERR(cow)) |
be20aa9d CM |
269 | return PTR_ERR(cow); |
270 | ||
271 | copy_extent_buffer(cow, buf, 0, 0, cow->len); | |
272 | btrfs_set_header_bytenr(cow, cow->start); | |
273 | btrfs_set_header_generation(cow, trans->transid); | |
5d4f98a2 YZ |
274 | btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV); |
275 | btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN | | |
276 | BTRFS_HEADER_FLAG_RELOC); | |
277 | if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID) | |
278 | btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC); | |
279 | else | |
280 | btrfs_set_header_owner(cow, new_root_objectid); | |
be20aa9d | 281 | |
2b82032c YZ |
282 | write_extent_buffer(cow, root->fs_info->fsid, |
283 | (unsigned long)btrfs_header_fsid(cow), | |
284 | BTRFS_FSID_SIZE); | |
285 | ||
be20aa9d | 286 | WARN_ON(btrfs_header_generation(buf) > trans->transid); |
5d4f98a2 | 287 | if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID) |
66d7e7f0 | 288 | ret = btrfs_inc_ref(trans, root, cow, 1, 1); |
5d4f98a2 | 289 | else |
66d7e7f0 | 290 | ret = btrfs_inc_ref(trans, root, cow, 0, 1); |
4aec2b52 | 291 | |
be20aa9d CM |
292 | if (ret) |
293 | return ret; | |
294 | ||
295 | btrfs_mark_buffer_dirty(cow); | |
296 | *cow_ret = cow; | |
297 | return 0; | |
298 | } | |
299 | ||
bd989ba3 JS |
300 | enum mod_log_op { |
301 | MOD_LOG_KEY_REPLACE, | |
302 | MOD_LOG_KEY_ADD, | |
303 | MOD_LOG_KEY_REMOVE, | |
304 | MOD_LOG_KEY_REMOVE_WHILE_FREEING, | |
305 | MOD_LOG_KEY_REMOVE_WHILE_MOVING, | |
306 | MOD_LOG_MOVE_KEYS, | |
307 | MOD_LOG_ROOT_REPLACE, | |
308 | }; | |
309 | ||
310 | struct tree_mod_move { | |
311 | int dst_slot; | |
312 | int nr_items; | |
313 | }; | |
314 | ||
315 | struct tree_mod_root { | |
316 | u64 logical; | |
317 | u8 level; | |
318 | }; | |
319 | ||
320 | struct tree_mod_elem { | |
321 | struct rb_node node; | |
322 | u64 index; /* shifted logical */ | |
097b8a7c | 323 | u64 seq; |
bd989ba3 JS |
324 | enum mod_log_op op; |
325 | ||
326 | /* this is used for MOD_LOG_KEY_* and MOD_LOG_MOVE_KEYS operations */ | |
327 | int slot; | |
328 | ||
329 | /* this is used for MOD_LOG_KEY* and MOD_LOG_ROOT_REPLACE */ | |
330 | u64 generation; | |
331 | ||
332 | /* those are used for op == MOD_LOG_KEY_{REPLACE,REMOVE} */ | |
333 | struct btrfs_disk_key key; | |
334 | u64 blockptr; | |
335 | ||
336 | /* this is used for op == MOD_LOG_MOVE_KEYS */ | |
337 | struct tree_mod_move move; | |
338 | ||
339 | /* this is used for op == MOD_LOG_ROOT_REPLACE */ | |
340 | struct tree_mod_root old_root; | |
341 | }; | |
342 | ||
097b8a7c | 343 | static inline void tree_mod_log_read_lock(struct btrfs_fs_info *fs_info) |
bd989ba3 | 344 | { |
097b8a7c | 345 | read_lock(&fs_info->tree_mod_log_lock); |
bd989ba3 JS |
346 | } |
347 | ||
097b8a7c JS |
348 | static inline void tree_mod_log_read_unlock(struct btrfs_fs_info *fs_info) |
349 | { | |
350 | read_unlock(&fs_info->tree_mod_log_lock); | |
351 | } | |
352 | ||
353 | static inline void tree_mod_log_write_lock(struct btrfs_fs_info *fs_info) | |
354 | { | |
355 | write_lock(&fs_info->tree_mod_log_lock); | |
356 | } | |
357 | ||
358 | static inline void tree_mod_log_write_unlock(struct btrfs_fs_info *fs_info) | |
359 | { | |
360 | write_unlock(&fs_info->tree_mod_log_lock); | |
361 | } | |
362 | ||
363 | /* | |
364 | * This adds a new blocker to the tree mod log's blocker list if the @elem | |
365 | * passed does not already have a sequence number set. So when a caller expects | |
366 | * to record tree modifications, it should ensure to set elem->seq to zero | |
367 | * before calling btrfs_get_tree_mod_seq. | |
368 | * Returns a fresh, unused tree log modification sequence number, even if no new | |
369 | * blocker was added. | |
370 | */ | |
371 | u64 btrfs_get_tree_mod_seq(struct btrfs_fs_info *fs_info, | |
372 | struct seq_list *elem) | |
bd989ba3 | 373 | { |
097b8a7c JS |
374 | u64 seq; |
375 | ||
376 | tree_mod_log_write_lock(fs_info); | |
bd989ba3 | 377 | spin_lock(&fs_info->tree_mod_seq_lock); |
097b8a7c JS |
378 | if (!elem->seq) { |
379 | elem->seq = btrfs_inc_tree_mod_seq(fs_info); | |
380 | list_add_tail(&elem->list, &fs_info->tree_mod_seq_list); | |
381 | } | |
382 | seq = btrfs_inc_tree_mod_seq(fs_info); | |
bd989ba3 | 383 | spin_unlock(&fs_info->tree_mod_seq_lock); |
097b8a7c JS |
384 | tree_mod_log_write_unlock(fs_info); |
385 | ||
386 | return seq; | |
bd989ba3 JS |
387 | } |
388 | ||
389 | void btrfs_put_tree_mod_seq(struct btrfs_fs_info *fs_info, | |
390 | struct seq_list *elem) | |
391 | { | |
392 | struct rb_root *tm_root; | |
393 | struct rb_node *node; | |
394 | struct rb_node *next; | |
395 | struct seq_list *cur_elem; | |
396 | struct tree_mod_elem *tm; | |
397 | u64 min_seq = (u64)-1; | |
398 | u64 seq_putting = elem->seq; | |
399 | ||
400 | if (!seq_putting) | |
401 | return; | |
402 | ||
bd989ba3 JS |
403 | spin_lock(&fs_info->tree_mod_seq_lock); |
404 | list_del(&elem->list); | |
097b8a7c | 405 | elem->seq = 0; |
bd989ba3 JS |
406 | |
407 | list_for_each_entry(cur_elem, &fs_info->tree_mod_seq_list, list) { | |
097b8a7c | 408 | if (cur_elem->seq < min_seq) { |
bd989ba3 JS |
409 | if (seq_putting > cur_elem->seq) { |
410 | /* | |
411 | * blocker with lower sequence number exists, we | |
412 | * cannot remove anything from the log | |
413 | */ | |
097b8a7c JS |
414 | spin_unlock(&fs_info->tree_mod_seq_lock); |
415 | return; | |
bd989ba3 JS |
416 | } |
417 | min_seq = cur_elem->seq; | |
418 | } | |
419 | } | |
097b8a7c JS |
420 | spin_unlock(&fs_info->tree_mod_seq_lock); |
421 | ||
bd989ba3 JS |
422 | /* |
423 | * anything that's lower than the lowest existing (read: blocked) | |
424 | * sequence number can be removed from the tree. | |
425 | */ | |
097b8a7c | 426 | tree_mod_log_write_lock(fs_info); |
bd989ba3 JS |
427 | tm_root = &fs_info->tree_mod_log; |
428 | for (node = rb_first(tm_root); node; node = next) { | |
429 | next = rb_next(node); | |
430 | tm = container_of(node, struct tree_mod_elem, node); | |
097b8a7c | 431 | if (tm->seq > min_seq) |
bd989ba3 JS |
432 | continue; |
433 | rb_erase(node, tm_root); | |
bd989ba3 JS |
434 | kfree(tm); |
435 | } | |
097b8a7c | 436 | tree_mod_log_write_unlock(fs_info); |
bd989ba3 JS |
437 | } |
438 | ||
439 | /* | |
440 | * key order of the log: | |
441 | * index -> sequence | |
442 | * | |
443 | * the index is the shifted logical of the *new* root node for root replace | |
444 | * operations, or the shifted logical of the affected block for all other | |
445 | * operations. | |
446 | */ | |
447 | static noinline int | |
448 | __tree_mod_log_insert(struct btrfs_fs_info *fs_info, struct tree_mod_elem *tm) | |
449 | { | |
450 | struct rb_root *tm_root; | |
451 | struct rb_node **new; | |
452 | struct rb_node *parent = NULL; | |
453 | struct tree_mod_elem *cur; | |
bd989ba3 | 454 | |
097b8a7c | 455 | BUG_ON(!tm || !tm->seq); |
bd989ba3 | 456 | |
bd989ba3 JS |
457 | tm_root = &fs_info->tree_mod_log; |
458 | new = &tm_root->rb_node; | |
459 | while (*new) { | |
460 | cur = container_of(*new, struct tree_mod_elem, node); | |
461 | parent = *new; | |
462 | if (cur->index < tm->index) | |
463 | new = &((*new)->rb_left); | |
464 | else if (cur->index > tm->index) | |
465 | new = &((*new)->rb_right); | |
097b8a7c | 466 | else if (cur->seq < tm->seq) |
bd989ba3 | 467 | new = &((*new)->rb_left); |
097b8a7c | 468 | else if (cur->seq > tm->seq) |
bd989ba3 JS |
469 | new = &((*new)->rb_right); |
470 | else { | |
471 | kfree(tm); | |
097b8a7c | 472 | return -EEXIST; |
bd989ba3 JS |
473 | } |
474 | } | |
475 | ||
476 | rb_link_node(&tm->node, parent, new); | |
477 | rb_insert_color(&tm->node, tm_root); | |
097b8a7c | 478 | return 0; |
bd989ba3 JS |
479 | } |
480 | ||
097b8a7c JS |
481 | /* |
482 | * Determines if logging can be omitted. Returns 1 if it can. Otherwise, it | |
483 | * returns zero with the tree_mod_log_lock acquired. The caller must hold | |
484 | * this until all tree mod log insertions are recorded in the rb tree and then | |
485 | * call tree_mod_log_write_unlock() to release. | |
486 | */ | |
e9b7fd4d JS |
487 | static inline int tree_mod_dont_log(struct btrfs_fs_info *fs_info, |
488 | struct extent_buffer *eb) { | |
489 | smp_mb(); | |
490 | if (list_empty(&(fs_info)->tree_mod_seq_list)) | |
491 | return 1; | |
097b8a7c JS |
492 | if (eb && btrfs_header_level(eb) == 0) |
493 | return 1; | |
494 | ||
495 | tree_mod_log_write_lock(fs_info); | |
496 | if (list_empty(&fs_info->tree_mod_seq_list)) { | |
497 | /* | |
498 | * someone emptied the list while we were waiting for the lock. | |
499 | * we must not add to the list when no blocker exists. | |
500 | */ | |
501 | tree_mod_log_write_unlock(fs_info); | |
e9b7fd4d | 502 | return 1; |
097b8a7c JS |
503 | } |
504 | ||
e9b7fd4d JS |
505 | return 0; |
506 | } | |
507 | ||
3310c36e | 508 | /* |
097b8a7c | 509 | * This allocates memory and gets a tree modification sequence number. |
3310c36e | 510 | * |
097b8a7c JS |
511 | * Returns <0 on error. |
512 | * Returns >0 (the added sequence number) on success. | |
3310c36e | 513 | */ |
926dd8a6 JS |
514 | static inline int tree_mod_alloc(struct btrfs_fs_info *fs_info, gfp_t flags, |
515 | struct tree_mod_elem **tm_ret) | |
bd989ba3 JS |
516 | { |
517 | struct tree_mod_elem *tm; | |
bd989ba3 | 518 | |
097b8a7c JS |
519 | /* |
520 | * once we switch from spin locks to something different, we should | |
521 | * honor the flags parameter here. | |
522 | */ | |
523 | tm = *tm_ret = kzalloc(sizeof(*tm), GFP_ATOMIC); | |
bd989ba3 JS |
524 | if (!tm) |
525 | return -ENOMEM; | |
526 | ||
097b8a7c JS |
527 | tm->seq = btrfs_inc_tree_mod_seq(fs_info); |
528 | return tm->seq; | |
bd989ba3 JS |
529 | } |
530 | ||
097b8a7c JS |
531 | static inline int |
532 | __tree_mod_log_insert_key(struct btrfs_fs_info *fs_info, | |
533 | struct extent_buffer *eb, int slot, | |
534 | enum mod_log_op op, gfp_t flags) | |
bd989ba3 | 535 | { |
bd989ba3 | 536 | int ret; |
097b8a7c | 537 | struct tree_mod_elem *tm; |
bd989ba3 JS |
538 | |
539 | ret = tree_mod_alloc(fs_info, flags, &tm); | |
097b8a7c | 540 | if (ret < 0) |
bd989ba3 JS |
541 | return ret; |
542 | ||
543 | tm->index = eb->start >> PAGE_CACHE_SHIFT; | |
544 | if (op != MOD_LOG_KEY_ADD) { | |
545 | btrfs_node_key(eb, &tm->key, slot); | |
546 | tm->blockptr = btrfs_node_blockptr(eb, slot); | |
547 | } | |
548 | tm->op = op; | |
549 | tm->slot = slot; | |
550 | tm->generation = btrfs_node_ptr_generation(eb, slot); | |
551 | ||
097b8a7c JS |
552 | return __tree_mod_log_insert(fs_info, tm); |
553 | } | |
554 | ||
555 | static noinline int | |
556 | tree_mod_log_insert_key_mask(struct btrfs_fs_info *fs_info, | |
557 | struct extent_buffer *eb, int slot, | |
558 | enum mod_log_op op, gfp_t flags) | |
559 | { | |
560 | int ret; | |
561 | ||
562 | if (tree_mod_dont_log(fs_info, eb)) | |
563 | return 0; | |
564 | ||
565 | ret = __tree_mod_log_insert_key(fs_info, eb, slot, op, flags); | |
566 | ||
567 | tree_mod_log_write_unlock(fs_info); | |
3310c36e | 568 | return ret; |
bd989ba3 JS |
569 | } |
570 | ||
571 | static noinline int | |
572 | tree_mod_log_insert_key(struct btrfs_fs_info *fs_info, struct extent_buffer *eb, | |
573 | int slot, enum mod_log_op op) | |
574 | { | |
575 | return tree_mod_log_insert_key_mask(fs_info, eb, slot, op, GFP_NOFS); | |
576 | } | |
577 | ||
097b8a7c JS |
578 | static noinline int |
579 | tree_mod_log_insert_key_locked(struct btrfs_fs_info *fs_info, | |
580 | struct extent_buffer *eb, int slot, | |
581 | enum mod_log_op op) | |
582 | { | |
583 | return __tree_mod_log_insert_key(fs_info, eb, slot, op, GFP_NOFS); | |
584 | } | |
585 | ||
bd989ba3 JS |
586 | static noinline int |
587 | tree_mod_log_insert_move(struct btrfs_fs_info *fs_info, | |
588 | struct extent_buffer *eb, int dst_slot, int src_slot, | |
589 | int nr_items, gfp_t flags) | |
590 | { | |
591 | struct tree_mod_elem *tm; | |
592 | int ret; | |
593 | int i; | |
594 | ||
f395694c JS |
595 | if (tree_mod_dont_log(fs_info, eb)) |
596 | return 0; | |
bd989ba3 | 597 | |
01763a2e JS |
598 | /* |
599 | * When we override something during the move, we log these removals. | |
600 | * This can only happen when we move towards the beginning of the | |
601 | * buffer, i.e. dst_slot < src_slot. | |
602 | */ | |
bd989ba3 | 603 | for (i = 0; i + dst_slot < src_slot && i < nr_items; i++) { |
097b8a7c | 604 | ret = tree_mod_log_insert_key_locked(fs_info, eb, i + dst_slot, |
bd989ba3 JS |
605 | MOD_LOG_KEY_REMOVE_WHILE_MOVING); |
606 | BUG_ON(ret < 0); | |
607 | } | |
608 | ||
f395694c | 609 | ret = tree_mod_alloc(fs_info, flags, &tm); |
097b8a7c JS |
610 | if (ret < 0) |
611 | goto out; | |
f395694c | 612 | |
bd989ba3 JS |
613 | tm->index = eb->start >> PAGE_CACHE_SHIFT; |
614 | tm->slot = src_slot; | |
615 | tm->move.dst_slot = dst_slot; | |
616 | tm->move.nr_items = nr_items; | |
617 | tm->op = MOD_LOG_MOVE_KEYS; | |
618 | ||
3310c36e | 619 | ret = __tree_mod_log_insert(fs_info, tm); |
097b8a7c JS |
620 | out: |
621 | tree_mod_log_write_unlock(fs_info); | |
3310c36e | 622 | return ret; |
bd989ba3 JS |
623 | } |
624 | ||
097b8a7c JS |
625 | static inline void |
626 | __tree_mod_log_free_eb(struct btrfs_fs_info *fs_info, struct extent_buffer *eb) | |
627 | { | |
628 | int i; | |
629 | u32 nritems; | |
630 | int ret; | |
631 | ||
b12a3b1e CM |
632 | if (btrfs_header_level(eb) == 0) |
633 | return; | |
634 | ||
097b8a7c JS |
635 | nritems = btrfs_header_nritems(eb); |
636 | for (i = nritems - 1; i >= 0; i--) { | |
637 | ret = tree_mod_log_insert_key_locked(fs_info, eb, i, | |
638 | MOD_LOG_KEY_REMOVE_WHILE_FREEING); | |
639 | BUG_ON(ret < 0); | |
640 | } | |
641 | } | |
642 | ||
bd989ba3 JS |
643 | static noinline int |
644 | tree_mod_log_insert_root(struct btrfs_fs_info *fs_info, | |
645 | struct extent_buffer *old_root, | |
646 | struct extent_buffer *new_root, gfp_t flags) | |
647 | { | |
648 | struct tree_mod_elem *tm; | |
649 | int ret; | |
650 | ||
097b8a7c JS |
651 | if (tree_mod_dont_log(fs_info, NULL)) |
652 | return 0; | |
653 | ||
bd989ba3 | 654 | ret = tree_mod_alloc(fs_info, flags, &tm); |
097b8a7c JS |
655 | if (ret < 0) |
656 | goto out; | |
bd989ba3 JS |
657 | |
658 | tm->index = new_root->start >> PAGE_CACHE_SHIFT; | |
659 | tm->old_root.logical = old_root->start; | |
660 | tm->old_root.level = btrfs_header_level(old_root); | |
661 | tm->generation = btrfs_header_generation(old_root); | |
662 | tm->op = MOD_LOG_ROOT_REPLACE; | |
663 | ||
3310c36e | 664 | ret = __tree_mod_log_insert(fs_info, tm); |
097b8a7c JS |
665 | out: |
666 | tree_mod_log_write_unlock(fs_info); | |
3310c36e | 667 | return ret; |
bd989ba3 JS |
668 | } |
669 | ||
670 | static struct tree_mod_elem * | |
671 | __tree_mod_log_search(struct btrfs_fs_info *fs_info, u64 start, u64 min_seq, | |
672 | int smallest) | |
673 | { | |
674 | struct rb_root *tm_root; | |
675 | struct rb_node *node; | |
676 | struct tree_mod_elem *cur = NULL; | |
677 | struct tree_mod_elem *found = NULL; | |
678 | u64 index = start >> PAGE_CACHE_SHIFT; | |
679 | ||
097b8a7c | 680 | tree_mod_log_read_lock(fs_info); |
bd989ba3 JS |
681 | tm_root = &fs_info->tree_mod_log; |
682 | node = tm_root->rb_node; | |
683 | while (node) { | |
684 | cur = container_of(node, struct tree_mod_elem, node); | |
685 | if (cur->index < index) { | |
686 | node = node->rb_left; | |
687 | } else if (cur->index > index) { | |
688 | node = node->rb_right; | |
097b8a7c | 689 | } else if (cur->seq < min_seq) { |
bd989ba3 JS |
690 | node = node->rb_left; |
691 | } else if (!smallest) { | |
692 | /* we want the node with the highest seq */ | |
693 | if (found) | |
097b8a7c | 694 | BUG_ON(found->seq > cur->seq); |
bd989ba3 JS |
695 | found = cur; |
696 | node = node->rb_left; | |
097b8a7c | 697 | } else if (cur->seq > min_seq) { |
bd989ba3 JS |
698 | /* we want the node with the smallest seq */ |
699 | if (found) | |
097b8a7c | 700 | BUG_ON(found->seq < cur->seq); |
bd989ba3 JS |
701 | found = cur; |
702 | node = node->rb_right; | |
703 | } else { | |
704 | found = cur; | |
705 | break; | |
706 | } | |
707 | } | |
097b8a7c | 708 | tree_mod_log_read_unlock(fs_info); |
bd989ba3 JS |
709 | |
710 | return found; | |
711 | } | |
712 | ||
713 | /* | |
714 | * this returns the element from the log with the smallest time sequence | |
715 | * value that's in the log (the oldest log item). any element with a time | |
716 | * sequence lower than min_seq will be ignored. | |
717 | */ | |
718 | static struct tree_mod_elem * | |
719 | tree_mod_log_search_oldest(struct btrfs_fs_info *fs_info, u64 start, | |
720 | u64 min_seq) | |
721 | { | |
722 | return __tree_mod_log_search(fs_info, start, min_seq, 1); | |
723 | } | |
724 | ||
725 | /* | |
726 | * this returns the element from the log with the largest time sequence | |
727 | * value that's in the log (the most recent log item). any element with | |
728 | * a time sequence lower than min_seq will be ignored. | |
729 | */ | |
730 | static struct tree_mod_elem * | |
731 | tree_mod_log_search(struct btrfs_fs_info *fs_info, u64 start, u64 min_seq) | |
732 | { | |
733 | return __tree_mod_log_search(fs_info, start, min_seq, 0); | |
734 | } | |
735 | ||
097b8a7c | 736 | static noinline void |
bd989ba3 JS |
737 | tree_mod_log_eb_copy(struct btrfs_fs_info *fs_info, struct extent_buffer *dst, |
738 | struct extent_buffer *src, unsigned long dst_offset, | |
739 | unsigned long src_offset, int nr_items) | |
740 | { | |
741 | int ret; | |
742 | int i; | |
743 | ||
e9b7fd4d | 744 | if (tree_mod_dont_log(fs_info, NULL)) |
bd989ba3 JS |
745 | return; |
746 | ||
097b8a7c JS |
747 | if (btrfs_header_level(dst) == 0 && btrfs_header_level(src) == 0) { |
748 | tree_mod_log_write_unlock(fs_info); | |
bd989ba3 | 749 | return; |
097b8a7c | 750 | } |
bd989ba3 | 751 | |
bd989ba3 | 752 | for (i = 0; i < nr_items; i++) { |
097b8a7c JS |
753 | ret = tree_mod_log_insert_key_locked(fs_info, src, |
754 | i + src_offset, | |
755 | MOD_LOG_KEY_REMOVE); | |
bd989ba3 | 756 | BUG_ON(ret < 0); |
097b8a7c JS |
757 | ret = tree_mod_log_insert_key_locked(fs_info, dst, |
758 | i + dst_offset, | |
759 | MOD_LOG_KEY_ADD); | |
bd989ba3 JS |
760 | BUG_ON(ret < 0); |
761 | } | |
097b8a7c JS |
762 | |
763 | tree_mod_log_write_unlock(fs_info); | |
bd989ba3 JS |
764 | } |
765 | ||
766 | static inline void | |
767 | tree_mod_log_eb_move(struct btrfs_fs_info *fs_info, struct extent_buffer *dst, | |
768 | int dst_offset, int src_offset, int nr_items) | |
769 | { | |
770 | int ret; | |
771 | ret = tree_mod_log_insert_move(fs_info, dst, dst_offset, src_offset, | |
772 | nr_items, GFP_NOFS); | |
773 | BUG_ON(ret < 0); | |
774 | } | |
775 | ||
097b8a7c | 776 | static noinline void |
bd989ba3 | 777 | tree_mod_log_set_node_key(struct btrfs_fs_info *fs_info, |
32adf090 | 778 | struct extent_buffer *eb, int slot, int atomic) |
bd989ba3 JS |
779 | { |
780 | int ret; | |
781 | ||
782 | ret = tree_mod_log_insert_key_mask(fs_info, eb, slot, | |
783 | MOD_LOG_KEY_REPLACE, | |
784 | atomic ? GFP_ATOMIC : GFP_NOFS); | |
785 | BUG_ON(ret < 0); | |
786 | } | |
787 | ||
097b8a7c JS |
788 | static noinline void |
789 | tree_mod_log_free_eb(struct btrfs_fs_info *fs_info, struct extent_buffer *eb) | |
bd989ba3 | 790 | { |
e9b7fd4d | 791 | if (tree_mod_dont_log(fs_info, eb)) |
bd989ba3 JS |
792 | return; |
793 | ||
097b8a7c JS |
794 | __tree_mod_log_free_eb(fs_info, eb); |
795 | ||
796 | tree_mod_log_write_unlock(fs_info); | |
bd989ba3 JS |
797 | } |
798 | ||
097b8a7c | 799 | static noinline void |
bd989ba3 JS |
800 | tree_mod_log_set_root_pointer(struct btrfs_root *root, |
801 | struct extent_buffer *new_root_node) | |
802 | { | |
803 | int ret; | |
bd989ba3 JS |
804 | ret = tree_mod_log_insert_root(root->fs_info, root->node, |
805 | new_root_node, GFP_NOFS); | |
806 | BUG_ON(ret < 0); | |
807 | } | |
808 | ||
5d4f98a2 YZ |
809 | /* |
810 | * check if the tree block can be shared by multiple trees | |
811 | */ | |
812 | int btrfs_block_can_be_shared(struct btrfs_root *root, | |
813 | struct extent_buffer *buf) | |
814 | { | |
815 | /* | |
816 | * Tree blocks not in refernece counted trees and tree roots | |
817 | * are never shared. If a block was allocated after the last | |
818 | * snapshot and the block was not allocated by tree relocation, | |
819 | * we know the block is not shared. | |
820 | */ | |
821 | if (root->ref_cows && | |
822 | buf != root->node && buf != root->commit_root && | |
823 | (btrfs_header_generation(buf) <= | |
824 | btrfs_root_last_snapshot(&root->root_item) || | |
825 | btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC))) | |
826 | return 1; | |
827 | #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 | |
828 | if (root->ref_cows && | |
829 | btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) | |
830 | return 1; | |
831 | #endif | |
832 | return 0; | |
833 | } | |
834 | ||
835 | static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans, | |
836 | struct btrfs_root *root, | |
837 | struct extent_buffer *buf, | |
f0486c68 YZ |
838 | struct extent_buffer *cow, |
839 | int *last_ref) | |
5d4f98a2 YZ |
840 | { |
841 | u64 refs; | |
842 | u64 owner; | |
843 | u64 flags; | |
844 | u64 new_flags = 0; | |
845 | int ret; | |
846 | ||
847 | /* | |
848 | * Backrefs update rules: | |
849 | * | |
850 | * Always use full backrefs for extent pointers in tree block | |
851 | * allocated by tree relocation. | |
852 | * | |
853 | * If a shared tree block is no longer referenced by its owner | |
854 | * tree (btrfs_header_owner(buf) == root->root_key.objectid), | |
855 | * use full backrefs for extent pointers in tree block. | |
856 | * | |
857 | * If a tree block is been relocating | |
858 | * (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID), | |
859 | * use full backrefs for extent pointers in tree block. | |
860 | * The reason for this is some operations (such as drop tree) | |
861 | * are only allowed for blocks use full backrefs. | |
862 | */ | |
863 | ||
864 | if (btrfs_block_can_be_shared(root, buf)) { | |
865 | ret = btrfs_lookup_extent_info(trans, root, buf->start, | |
866 | buf->len, &refs, &flags); | |
be1a5564 MF |
867 | if (ret) |
868 | return ret; | |
e5df9573 MF |
869 | if (refs == 0) { |
870 | ret = -EROFS; | |
871 | btrfs_std_error(root->fs_info, ret); | |
872 | return ret; | |
873 | } | |
5d4f98a2 YZ |
874 | } else { |
875 | refs = 1; | |
876 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID || | |
877 | btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) | |
878 | flags = BTRFS_BLOCK_FLAG_FULL_BACKREF; | |
879 | else | |
880 | flags = 0; | |
881 | } | |
882 | ||
883 | owner = btrfs_header_owner(buf); | |
884 | BUG_ON(owner == BTRFS_TREE_RELOC_OBJECTID && | |
885 | !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)); | |
886 | ||
887 | if (refs > 1) { | |
888 | if ((owner == root->root_key.objectid || | |
889 | root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) && | |
890 | !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)) { | |
66d7e7f0 | 891 | ret = btrfs_inc_ref(trans, root, buf, 1, 1); |
79787eaa | 892 | BUG_ON(ret); /* -ENOMEM */ |
5d4f98a2 YZ |
893 | |
894 | if (root->root_key.objectid == | |
895 | BTRFS_TREE_RELOC_OBJECTID) { | |
66d7e7f0 | 896 | ret = btrfs_dec_ref(trans, root, buf, 0, 1); |
79787eaa | 897 | BUG_ON(ret); /* -ENOMEM */ |
66d7e7f0 | 898 | ret = btrfs_inc_ref(trans, root, cow, 1, 1); |
79787eaa | 899 | BUG_ON(ret); /* -ENOMEM */ |
5d4f98a2 YZ |
900 | } |
901 | new_flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF; | |
902 | } else { | |
903 | ||
904 | if (root->root_key.objectid == | |
905 | BTRFS_TREE_RELOC_OBJECTID) | |
66d7e7f0 | 906 | ret = btrfs_inc_ref(trans, root, cow, 1, 1); |
5d4f98a2 | 907 | else |
66d7e7f0 | 908 | ret = btrfs_inc_ref(trans, root, cow, 0, 1); |
79787eaa | 909 | BUG_ON(ret); /* -ENOMEM */ |
5d4f98a2 YZ |
910 | } |
911 | if (new_flags != 0) { | |
912 | ret = btrfs_set_disk_extent_flags(trans, root, | |
913 | buf->start, | |
914 | buf->len, | |
915 | new_flags, 0); | |
be1a5564 MF |
916 | if (ret) |
917 | return ret; | |
5d4f98a2 YZ |
918 | } |
919 | } else { | |
920 | if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF) { | |
921 | if (root->root_key.objectid == | |
922 | BTRFS_TREE_RELOC_OBJECTID) | |
66d7e7f0 | 923 | ret = btrfs_inc_ref(trans, root, cow, 1, 1); |
5d4f98a2 | 924 | else |
66d7e7f0 | 925 | ret = btrfs_inc_ref(trans, root, cow, 0, 1); |
79787eaa | 926 | BUG_ON(ret); /* -ENOMEM */ |
66d7e7f0 | 927 | ret = btrfs_dec_ref(trans, root, buf, 1, 1); |
79787eaa | 928 | BUG_ON(ret); /* -ENOMEM */ |
5d4f98a2 | 929 | } |
ba1bfbd5 | 930 | tree_mod_log_free_eb(root->fs_info, buf); |
5d4f98a2 | 931 | clean_tree_block(trans, root, buf); |
f0486c68 | 932 | *last_ref = 1; |
5d4f98a2 YZ |
933 | } |
934 | return 0; | |
935 | } | |
936 | ||
d352ac68 | 937 | /* |
d397712b CM |
938 | * does the dirty work in cow of a single block. The parent block (if |
939 | * supplied) is updated to point to the new cow copy. The new buffer is marked | |
940 | * dirty and returned locked. If you modify the block it needs to be marked | |
941 | * dirty again. | |
d352ac68 CM |
942 | * |
943 | * search_start -- an allocation hint for the new block | |
944 | * | |
d397712b CM |
945 | * empty_size -- a hint that you plan on doing more cow. This is the size in |
946 | * bytes the allocator should try to find free next to the block it returns. | |
947 | * This is just a hint and may be ignored by the allocator. | |
d352ac68 | 948 | */ |
d397712b | 949 | static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans, |
5f39d397 CM |
950 | struct btrfs_root *root, |
951 | struct extent_buffer *buf, | |
952 | struct extent_buffer *parent, int parent_slot, | |
953 | struct extent_buffer **cow_ret, | |
9fa8cfe7 | 954 | u64 search_start, u64 empty_size) |
02217ed2 | 955 | { |
5d4f98a2 | 956 | struct btrfs_disk_key disk_key; |
5f39d397 | 957 | struct extent_buffer *cow; |
be1a5564 | 958 | int level, ret; |
f0486c68 | 959 | int last_ref = 0; |
925baedd | 960 | int unlock_orig = 0; |
5d4f98a2 | 961 | u64 parent_start; |
7bb86316 | 962 | |
925baedd CM |
963 | if (*cow_ret == buf) |
964 | unlock_orig = 1; | |
965 | ||
b9447ef8 | 966 | btrfs_assert_tree_locked(buf); |
925baedd | 967 | |
7bb86316 CM |
968 | WARN_ON(root->ref_cows && trans->transid != |
969 | root->fs_info->running_transaction->transid); | |
6702ed49 | 970 | WARN_ON(root->ref_cows && trans->transid != root->last_trans); |
5f39d397 | 971 | |
7bb86316 | 972 | level = btrfs_header_level(buf); |
31840ae1 | 973 | |
5d4f98a2 YZ |
974 | if (level == 0) |
975 | btrfs_item_key(buf, &disk_key, 0); | |
976 | else | |
977 | btrfs_node_key(buf, &disk_key, 0); | |
978 | ||
979 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) { | |
980 | if (parent) | |
981 | parent_start = parent->start; | |
982 | else | |
983 | parent_start = 0; | |
984 | } else | |
985 | parent_start = 0; | |
986 | ||
987 | cow = btrfs_alloc_free_block(trans, root, buf->len, parent_start, | |
988 | root->root_key.objectid, &disk_key, | |
5581a51a | 989 | level, search_start, empty_size); |
54aa1f4d CM |
990 | if (IS_ERR(cow)) |
991 | return PTR_ERR(cow); | |
6702ed49 | 992 | |
b4ce94de CM |
993 | /* cow is set to blocking by btrfs_init_new_buffer */ |
994 | ||
5f39d397 | 995 | copy_extent_buffer(cow, buf, 0, 0, cow->len); |
db94535d | 996 | btrfs_set_header_bytenr(cow, cow->start); |
5f39d397 | 997 | btrfs_set_header_generation(cow, trans->transid); |
5d4f98a2 YZ |
998 | btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV); |
999 | btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN | | |
1000 | BTRFS_HEADER_FLAG_RELOC); | |
1001 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) | |
1002 | btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC); | |
1003 | else | |
1004 | btrfs_set_header_owner(cow, root->root_key.objectid); | |
6702ed49 | 1005 | |
2b82032c YZ |
1006 | write_extent_buffer(cow, root->fs_info->fsid, |
1007 | (unsigned long)btrfs_header_fsid(cow), | |
1008 | BTRFS_FSID_SIZE); | |
1009 | ||
be1a5564 | 1010 | ret = update_ref_for_cow(trans, root, buf, cow, &last_ref); |
b68dc2a9 | 1011 | if (ret) { |
79787eaa | 1012 | btrfs_abort_transaction(trans, root, ret); |
b68dc2a9 MF |
1013 | return ret; |
1014 | } | |
1a40e23b | 1015 | |
3fd0a558 YZ |
1016 | if (root->ref_cows) |
1017 | btrfs_reloc_cow_block(trans, root, buf, cow); | |
1018 | ||
02217ed2 | 1019 | if (buf == root->node) { |
925baedd | 1020 | WARN_ON(parent && parent != buf); |
5d4f98a2 YZ |
1021 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID || |
1022 | btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) | |
1023 | parent_start = buf->start; | |
1024 | else | |
1025 | parent_start = 0; | |
925baedd | 1026 | |
5f39d397 | 1027 | extent_buffer_get(cow); |
f230475e | 1028 | tree_mod_log_set_root_pointer(root, cow); |
240f62c8 | 1029 | rcu_assign_pointer(root->node, cow); |
925baedd | 1030 | |
f0486c68 | 1031 | btrfs_free_tree_block(trans, root, buf, parent_start, |
5581a51a | 1032 | last_ref); |
5f39d397 | 1033 | free_extent_buffer(buf); |
0b86a832 | 1034 | add_root_to_dirty_list(root); |
02217ed2 | 1035 | } else { |
5d4f98a2 YZ |
1036 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) |
1037 | parent_start = parent->start; | |
1038 | else | |
1039 | parent_start = 0; | |
1040 | ||
1041 | WARN_ON(trans->transid != btrfs_header_generation(parent)); | |
f230475e JS |
1042 | tree_mod_log_insert_key(root->fs_info, parent, parent_slot, |
1043 | MOD_LOG_KEY_REPLACE); | |
5f39d397 | 1044 | btrfs_set_node_blockptr(parent, parent_slot, |
db94535d | 1045 | cow->start); |
74493f7a CM |
1046 | btrfs_set_node_ptr_generation(parent, parent_slot, |
1047 | trans->transid); | |
d6025579 | 1048 | btrfs_mark_buffer_dirty(parent); |
f0486c68 | 1049 | btrfs_free_tree_block(trans, root, buf, parent_start, |
5581a51a | 1050 | last_ref); |
02217ed2 | 1051 | } |
925baedd CM |
1052 | if (unlock_orig) |
1053 | btrfs_tree_unlock(buf); | |
3083ee2e | 1054 | free_extent_buffer_stale(buf); |
ccd467d6 | 1055 | btrfs_mark_buffer_dirty(cow); |
2c90e5d6 | 1056 | *cow_ret = cow; |
02217ed2 CM |
1057 | return 0; |
1058 | } | |
1059 | ||
5d9e75c4 JS |
1060 | /* |
1061 | * returns the logical address of the oldest predecessor of the given root. | |
1062 | * entries older than time_seq are ignored. | |
1063 | */ | |
1064 | static struct tree_mod_elem * | |
1065 | __tree_mod_log_oldest_root(struct btrfs_fs_info *fs_info, | |
1066 | struct btrfs_root *root, u64 time_seq) | |
1067 | { | |
1068 | struct tree_mod_elem *tm; | |
1069 | struct tree_mod_elem *found = NULL; | |
1070 | u64 root_logical = root->node->start; | |
1071 | int looped = 0; | |
1072 | ||
1073 | if (!time_seq) | |
1074 | return 0; | |
1075 | ||
1076 | /* | |
1077 | * the very last operation that's logged for a root is the replacement | |
1078 | * operation (if it is replaced at all). this has the index of the *new* | |
1079 | * root, making it the very first operation that's logged for this root. | |
1080 | */ | |
1081 | while (1) { | |
1082 | tm = tree_mod_log_search_oldest(fs_info, root_logical, | |
1083 | time_seq); | |
1084 | if (!looped && !tm) | |
1085 | return 0; | |
1086 | /* | |
28da9fb4 JS |
1087 | * if there are no tree operation for the oldest root, we simply |
1088 | * return it. this should only happen if that (old) root is at | |
1089 | * level 0. | |
5d9e75c4 | 1090 | */ |
28da9fb4 JS |
1091 | if (!tm) |
1092 | break; | |
5d9e75c4 | 1093 | |
28da9fb4 JS |
1094 | /* |
1095 | * if there's an operation that's not a root replacement, we | |
1096 | * found the oldest version of our root. normally, we'll find a | |
1097 | * MOD_LOG_KEY_REMOVE_WHILE_FREEING operation here. | |
1098 | */ | |
5d9e75c4 JS |
1099 | if (tm->op != MOD_LOG_ROOT_REPLACE) |
1100 | break; | |
1101 | ||
1102 | found = tm; | |
1103 | root_logical = tm->old_root.logical; | |
1104 | BUG_ON(root_logical == root->node->start); | |
1105 | looped = 1; | |
1106 | } | |
1107 | ||
a95236d9 JS |
1108 | /* if there's no old root to return, return what we found instead */ |
1109 | if (!found) | |
1110 | found = tm; | |
1111 | ||
5d9e75c4 JS |
1112 | return found; |
1113 | } | |
1114 | ||
1115 | /* | |
1116 | * tm is a pointer to the first operation to rewind within eb. then, all | |
1117 | * previous operations will be rewinded (until we reach something older than | |
1118 | * time_seq). | |
1119 | */ | |
1120 | static void | |
1121 | __tree_mod_log_rewind(struct extent_buffer *eb, u64 time_seq, | |
1122 | struct tree_mod_elem *first_tm) | |
1123 | { | |
1124 | u32 n; | |
1125 | struct rb_node *next; | |
1126 | struct tree_mod_elem *tm = first_tm; | |
1127 | unsigned long o_dst; | |
1128 | unsigned long o_src; | |
1129 | unsigned long p_size = sizeof(struct btrfs_key_ptr); | |
1130 | ||
1131 | n = btrfs_header_nritems(eb); | |
097b8a7c | 1132 | while (tm && tm->seq >= time_seq) { |
5d9e75c4 JS |
1133 | /* |
1134 | * all the operations are recorded with the operator used for | |
1135 | * the modification. as we're going backwards, we do the | |
1136 | * opposite of each operation here. | |
1137 | */ | |
1138 | switch (tm->op) { | |
1139 | case MOD_LOG_KEY_REMOVE_WHILE_FREEING: | |
1140 | BUG_ON(tm->slot < n); | |
1c697d4a | 1141 | /* Fallthrough */ |
95c80bb1 | 1142 | case MOD_LOG_KEY_REMOVE_WHILE_MOVING: |
4c3e6969 | 1143 | case MOD_LOG_KEY_REMOVE: |
5d9e75c4 JS |
1144 | btrfs_set_node_key(eb, &tm->key, tm->slot); |
1145 | btrfs_set_node_blockptr(eb, tm->slot, tm->blockptr); | |
1146 | btrfs_set_node_ptr_generation(eb, tm->slot, | |
1147 | tm->generation); | |
4c3e6969 | 1148 | n++; |
5d9e75c4 JS |
1149 | break; |
1150 | case MOD_LOG_KEY_REPLACE: | |
1151 | BUG_ON(tm->slot >= n); | |
1152 | btrfs_set_node_key(eb, &tm->key, tm->slot); | |
1153 | btrfs_set_node_blockptr(eb, tm->slot, tm->blockptr); | |
1154 | btrfs_set_node_ptr_generation(eb, tm->slot, | |
1155 | tm->generation); | |
1156 | break; | |
1157 | case MOD_LOG_KEY_ADD: | |
19956c7e | 1158 | /* if a move operation is needed it's in the log */ |
5d9e75c4 JS |
1159 | n--; |
1160 | break; | |
1161 | case MOD_LOG_MOVE_KEYS: | |
c3193108 JS |
1162 | o_dst = btrfs_node_key_ptr_offset(tm->slot); |
1163 | o_src = btrfs_node_key_ptr_offset(tm->move.dst_slot); | |
1164 | memmove_extent_buffer(eb, o_dst, o_src, | |
5d9e75c4 JS |
1165 | tm->move.nr_items * p_size); |
1166 | break; | |
1167 | case MOD_LOG_ROOT_REPLACE: | |
1168 | /* | |
1169 | * this operation is special. for roots, this must be | |
1170 | * handled explicitly before rewinding. | |
1171 | * for non-roots, this operation may exist if the node | |
1172 | * was a root: root A -> child B; then A gets empty and | |
1173 | * B is promoted to the new root. in the mod log, we'll | |
1174 | * have a root-replace operation for B, a tree block | |
1175 | * that is no root. we simply ignore that operation. | |
1176 | */ | |
1177 | break; | |
1178 | } | |
1179 | next = rb_next(&tm->node); | |
1180 | if (!next) | |
1181 | break; | |
1182 | tm = container_of(next, struct tree_mod_elem, node); | |
1183 | if (tm->index != first_tm->index) | |
1184 | break; | |
1185 | } | |
1186 | btrfs_set_header_nritems(eb, n); | |
1187 | } | |
1188 | ||
1189 | static struct extent_buffer * | |
1190 | tree_mod_log_rewind(struct btrfs_fs_info *fs_info, struct extent_buffer *eb, | |
1191 | u64 time_seq) | |
1192 | { | |
1193 | struct extent_buffer *eb_rewin; | |
1194 | struct tree_mod_elem *tm; | |
1195 | ||
1196 | if (!time_seq) | |
1197 | return eb; | |
1198 | ||
1199 | if (btrfs_header_level(eb) == 0) | |
1200 | return eb; | |
1201 | ||
1202 | tm = tree_mod_log_search(fs_info, eb->start, time_seq); | |
1203 | if (!tm) | |
1204 | return eb; | |
1205 | ||
1206 | if (tm->op == MOD_LOG_KEY_REMOVE_WHILE_FREEING) { | |
1207 | BUG_ON(tm->slot != 0); | |
1208 | eb_rewin = alloc_dummy_extent_buffer(eb->start, | |
1209 | fs_info->tree_root->nodesize); | |
1210 | BUG_ON(!eb_rewin); | |
1211 | btrfs_set_header_bytenr(eb_rewin, eb->start); | |
1212 | btrfs_set_header_backref_rev(eb_rewin, | |
1213 | btrfs_header_backref_rev(eb)); | |
1214 | btrfs_set_header_owner(eb_rewin, btrfs_header_owner(eb)); | |
c3193108 | 1215 | btrfs_set_header_level(eb_rewin, btrfs_header_level(eb)); |
5d9e75c4 JS |
1216 | } else { |
1217 | eb_rewin = btrfs_clone_extent_buffer(eb); | |
1218 | BUG_ON(!eb_rewin); | |
1219 | } | |
1220 | ||
1221 | extent_buffer_get(eb_rewin); | |
1222 | free_extent_buffer(eb); | |
1223 | ||
1224 | __tree_mod_log_rewind(eb_rewin, time_seq, tm); | |
57911b8b | 1225 | WARN_ON(btrfs_header_nritems(eb_rewin) > |
2a745b14 | 1226 | BTRFS_NODEPTRS_PER_BLOCK(fs_info->tree_root)); |
5d9e75c4 JS |
1227 | |
1228 | return eb_rewin; | |
1229 | } | |
1230 | ||
8ba97a15 JS |
1231 | /* |
1232 | * get_old_root() rewinds the state of @root's root node to the given @time_seq | |
1233 | * value. If there are no changes, the current root->root_node is returned. If | |
1234 | * anything changed in between, there's a fresh buffer allocated on which the | |
1235 | * rewind operations are done. In any case, the returned buffer is read locked. | |
1236 | * Returns NULL on error (with no locks held). | |
1237 | */ | |
5d9e75c4 JS |
1238 | static inline struct extent_buffer * |
1239 | get_old_root(struct btrfs_root *root, u64 time_seq) | |
1240 | { | |
1241 | struct tree_mod_elem *tm; | |
1242 | struct extent_buffer *eb; | |
7bfdcf7f | 1243 | struct extent_buffer *old; |
a95236d9 | 1244 | struct tree_mod_root *old_root = NULL; |
4325edd0 | 1245 | u64 old_generation = 0; |
a95236d9 | 1246 | u64 logical; |
834328a8 | 1247 | u32 blocksize; |
5d9e75c4 | 1248 | |
8ba97a15 | 1249 | eb = btrfs_read_lock_root_node(root); |
5d9e75c4 JS |
1250 | tm = __tree_mod_log_oldest_root(root->fs_info, root, time_seq); |
1251 | if (!tm) | |
1252 | return root->node; | |
1253 | ||
a95236d9 JS |
1254 | if (tm->op == MOD_LOG_ROOT_REPLACE) { |
1255 | old_root = &tm->old_root; | |
1256 | old_generation = tm->generation; | |
1257 | logical = old_root->logical; | |
1258 | } else { | |
1259 | logical = root->node->start; | |
1260 | } | |
5d9e75c4 | 1261 | |
a95236d9 | 1262 | tm = tree_mod_log_search(root->fs_info, logical, time_seq); |
834328a8 JS |
1263 | if (old_root && tm && tm->op != MOD_LOG_KEY_REMOVE_WHILE_FREEING) { |
1264 | btrfs_tree_read_unlock(root->node); | |
1265 | free_extent_buffer(root->node); | |
1266 | blocksize = btrfs_level_size(root, old_root->level); | |
7bfdcf7f LB |
1267 | old = read_tree_block(root, logical, blocksize, 0); |
1268 | if (!old) { | |
834328a8 JS |
1269 | pr_warn("btrfs: failed to read tree block %llu from get_old_root\n", |
1270 | logical); | |
1271 | WARN_ON(1); | |
1272 | } else { | |
7bfdcf7f LB |
1273 | eb = btrfs_clone_extent_buffer(old); |
1274 | free_extent_buffer(old); | |
834328a8 JS |
1275 | } |
1276 | } else if (old_root) { | |
1277 | btrfs_tree_read_unlock(root->node); | |
1278 | free_extent_buffer(root->node); | |
28da9fb4 | 1279 | eb = alloc_dummy_extent_buffer(logical, root->nodesize); |
834328a8 | 1280 | } else { |
a95236d9 | 1281 | eb = btrfs_clone_extent_buffer(root->node); |
834328a8 JS |
1282 | btrfs_tree_read_unlock(root->node); |
1283 | free_extent_buffer(root->node); | |
1284 | } | |
1285 | ||
8ba97a15 JS |
1286 | if (!eb) |
1287 | return NULL; | |
d6381084 | 1288 | extent_buffer_get(eb); |
8ba97a15 | 1289 | btrfs_tree_read_lock(eb); |
a95236d9 | 1290 | if (old_root) { |
5d9e75c4 JS |
1291 | btrfs_set_header_bytenr(eb, eb->start); |
1292 | btrfs_set_header_backref_rev(eb, BTRFS_MIXED_BACKREF_REV); | |
1293 | btrfs_set_header_owner(eb, root->root_key.objectid); | |
a95236d9 JS |
1294 | btrfs_set_header_level(eb, old_root->level); |
1295 | btrfs_set_header_generation(eb, old_generation); | |
5d9e75c4 | 1296 | } |
28da9fb4 JS |
1297 | if (tm) |
1298 | __tree_mod_log_rewind(eb, time_seq, tm); | |
1299 | else | |
1300 | WARN_ON(btrfs_header_level(eb) != 0); | |
57911b8b | 1301 | WARN_ON(btrfs_header_nritems(eb) > BTRFS_NODEPTRS_PER_BLOCK(root)); |
5d9e75c4 JS |
1302 | |
1303 | return eb; | |
1304 | } | |
1305 | ||
5b6602e7 JS |
1306 | int btrfs_old_root_level(struct btrfs_root *root, u64 time_seq) |
1307 | { | |
1308 | struct tree_mod_elem *tm; | |
1309 | int level; | |
1310 | ||
1311 | tm = __tree_mod_log_oldest_root(root->fs_info, root, time_seq); | |
1312 | if (tm && tm->op == MOD_LOG_ROOT_REPLACE) { | |
1313 | level = tm->old_root.level; | |
1314 | } else { | |
1315 | rcu_read_lock(); | |
1316 | level = btrfs_header_level(root->node); | |
1317 | rcu_read_unlock(); | |
1318 | } | |
1319 | ||
1320 | return level; | |
1321 | } | |
1322 | ||
5d4f98a2 YZ |
1323 | static inline int should_cow_block(struct btrfs_trans_handle *trans, |
1324 | struct btrfs_root *root, | |
1325 | struct extent_buffer *buf) | |
1326 | { | |
f1ebcc74 LB |
1327 | /* ensure we can see the force_cow */ |
1328 | smp_rmb(); | |
1329 | ||
1330 | /* | |
1331 | * We do not need to cow a block if | |
1332 | * 1) this block is not created or changed in this transaction; | |
1333 | * 2) this block does not belong to TREE_RELOC tree; | |
1334 | * 3) the root is not forced COW. | |
1335 | * | |
1336 | * What is forced COW: | |
1337 | * when we create snapshot during commiting the transaction, | |
1338 | * after we've finished coping src root, we must COW the shared | |
1339 | * block to ensure the metadata consistency. | |
1340 | */ | |
5d4f98a2 YZ |
1341 | if (btrfs_header_generation(buf) == trans->transid && |
1342 | !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN) && | |
1343 | !(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID && | |
f1ebcc74 LB |
1344 | btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC)) && |
1345 | !root->force_cow) | |
5d4f98a2 YZ |
1346 | return 0; |
1347 | return 1; | |
1348 | } | |
1349 | ||
d352ac68 CM |
1350 | /* |
1351 | * cows a single block, see __btrfs_cow_block for the real work. | |
1352 | * This version of it has extra checks so that a block isn't cow'd more than | |
1353 | * once per transaction, as long as it hasn't been written yet | |
1354 | */ | |
d397712b | 1355 | noinline int btrfs_cow_block(struct btrfs_trans_handle *trans, |
5f39d397 CM |
1356 | struct btrfs_root *root, struct extent_buffer *buf, |
1357 | struct extent_buffer *parent, int parent_slot, | |
9fa8cfe7 | 1358 | struct extent_buffer **cow_ret) |
6702ed49 CM |
1359 | { |
1360 | u64 search_start; | |
f510cfec | 1361 | int ret; |
dc17ff8f | 1362 | |
31b1a2bd JL |
1363 | if (trans->transaction != root->fs_info->running_transaction) |
1364 | WARN(1, KERN_CRIT "trans %llu running %llu\n", | |
d397712b CM |
1365 | (unsigned long long)trans->transid, |
1366 | (unsigned long long) | |
6702ed49 | 1367 | root->fs_info->running_transaction->transid); |
31b1a2bd JL |
1368 | |
1369 | if (trans->transid != root->fs_info->generation) | |
1370 | WARN(1, KERN_CRIT "trans %llu running %llu\n", | |
d397712b CM |
1371 | (unsigned long long)trans->transid, |
1372 | (unsigned long long)root->fs_info->generation); | |
dc17ff8f | 1373 | |
5d4f98a2 | 1374 | if (!should_cow_block(trans, root, buf)) { |
6702ed49 CM |
1375 | *cow_ret = buf; |
1376 | return 0; | |
1377 | } | |
c487685d | 1378 | |
0b86a832 | 1379 | search_start = buf->start & ~((u64)(1024 * 1024 * 1024) - 1); |
b4ce94de CM |
1380 | |
1381 | if (parent) | |
1382 | btrfs_set_lock_blocking(parent); | |
1383 | btrfs_set_lock_blocking(buf); | |
1384 | ||
f510cfec | 1385 | ret = __btrfs_cow_block(trans, root, buf, parent, |
9fa8cfe7 | 1386 | parent_slot, cow_ret, search_start, 0); |
1abe9b8a | 1387 | |
1388 | trace_btrfs_cow_block(root, buf, *cow_ret); | |
1389 | ||
f510cfec | 1390 | return ret; |
6702ed49 CM |
1391 | } |
1392 | ||
d352ac68 CM |
1393 | /* |
1394 | * helper function for defrag to decide if two blocks pointed to by a | |
1395 | * node are actually close by | |
1396 | */ | |
6b80053d | 1397 | static int close_blocks(u64 blocknr, u64 other, u32 blocksize) |
6702ed49 | 1398 | { |
6b80053d | 1399 | if (blocknr < other && other - (blocknr + blocksize) < 32768) |
6702ed49 | 1400 | return 1; |
6b80053d | 1401 | if (blocknr > other && blocknr - (other + blocksize) < 32768) |
6702ed49 CM |
1402 | return 1; |
1403 | return 0; | |
1404 | } | |
1405 | ||
081e9573 CM |
1406 | /* |
1407 | * compare two keys in a memcmp fashion | |
1408 | */ | |
1409 | static int comp_keys(struct btrfs_disk_key *disk, struct btrfs_key *k2) | |
1410 | { | |
1411 | struct btrfs_key k1; | |
1412 | ||
1413 | btrfs_disk_key_to_cpu(&k1, disk); | |
1414 | ||
20736aba | 1415 | return btrfs_comp_cpu_keys(&k1, k2); |
081e9573 CM |
1416 | } |
1417 | ||
f3465ca4 JB |
1418 | /* |
1419 | * same as comp_keys only with two btrfs_key's | |
1420 | */ | |
5d4f98a2 | 1421 | int btrfs_comp_cpu_keys(struct btrfs_key *k1, struct btrfs_key *k2) |
f3465ca4 JB |
1422 | { |
1423 | if (k1->objectid > k2->objectid) | |
1424 | return 1; | |
1425 | if (k1->objectid < k2->objectid) | |
1426 | return -1; | |
1427 | if (k1->type > k2->type) | |
1428 | return 1; | |
1429 | if (k1->type < k2->type) | |
1430 | return -1; | |
1431 | if (k1->offset > k2->offset) | |
1432 | return 1; | |
1433 | if (k1->offset < k2->offset) | |
1434 | return -1; | |
1435 | return 0; | |
1436 | } | |
081e9573 | 1437 | |
d352ac68 CM |
1438 | /* |
1439 | * this is used by the defrag code to go through all the | |
1440 | * leaves pointed to by a node and reallocate them so that | |
1441 | * disk order is close to key order | |
1442 | */ | |
6702ed49 | 1443 | int btrfs_realloc_node(struct btrfs_trans_handle *trans, |
5f39d397 | 1444 | struct btrfs_root *root, struct extent_buffer *parent, |
a6b6e75e CM |
1445 | int start_slot, int cache_only, u64 *last_ret, |
1446 | struct btrfs_key *progress) | |
6702ed49 | 1447 | { |
6b80053d | 1448 | struct extent_buffer *cur; |
6702ed49 | 1449 | u64 blocknr; |
ca7a79ad | 1450 | u64 gen; |
e9d0b13b CM |
1451 | u64 search_start = *last_ret; |
1452 | u64 last_block = 0; | |
6702ed49 CM |
1453 | u64 other; |
1454 | u32 parent_nritems; | |
6702ed49 CM |
1455 | int end_slot; |
1456 | int i; | |
1457 | int err = 0; | |
f2183bde | 1458 | int parent_level; |
6b80053d CM |
1459 | int uptodate; |
1460 | u32 blocksize; | |
081e9573 CM |
1461 | int progress_passed = 0; |
1462 | struct btrfs_disk_key disk_key; | |
6702ed49 | 1463 | |
5708b959 CM |
1464 | parent_level = btrfs_header_level(parent); |
1465 | if (cache_only && parent_level != 1) | |
1466 | return 0; | |
1467 | ||
6c1500f2 JL |
1468 | WARN_ON(trans->transaction != root->fs_info->running_transaction); |
1469 | WARN_ON(trans->transid != root->fs_info->generation); | |
86479a04 | 1470 | |
6b80053d | 1471 | parent_nritems = btrfs_header_nritems(parent); |
6b80053d | 1472 | blocksize = btrfs_level_size(root, parent_level - 1); |
6702ed49 CM |
1473 | end_slot = parent_nritems; |
1474 | ||
1475 | if (parent_nritems == 1) | |
1476 | return 0; | |
1477 | ||
b4ce94de CM |
1478 | btrfs_set_lock_blocking(parent); |
1479 | ||
6702ed49 CM |
1480 | for (i = start_slot; i < end_slot; i++) { |
1481 | int close = 1; | |
a6b6e75e | 1482 | |
081e9573 CM |
1483 | btrfs_node_key(parent, &disk_key, i); |
1484 | if (!progress_passed && comp_keys(&disk_key, progress) < 0) | |
1485 | continue; | |
1486 | ||
1487 | progress_passed = 1; | |
6b80053d | 1488 | blocknr = btrfs_node_blockptr(parent, i); |
ca7a79ad | 1489 | gen = btrfs_node_ptr_generation(parent, i); |
e9d0b13b CM |
1490 | if (last_block == 0) |
1491 | last_block = blocknr; | |
5708b959 | 1492 | |
6702ed49 | 1493 | if (i > 0) { |
6b80053d CM |
1494 | other = btrfs_node_blockptr(parent, i - 1); |
1495 | close = close_blocks(blocknr, other, blocksize); | |
6702ed49 | 1496 | } |
0ef3e66b | 1497 | if (!close && i < end_slot - 2) { |
6b80053d CM |
1498 | other = btrfs_node_blockptr(parent, i + 1); |
1499 | close = close_blocks(blocknr, other, blocksize); | |
6702ed49 | 1500 | } |
e9d0b13b CM |
1501 | if (close) { |
1502 | last_block = blocknr; | |
6702ed49 | 1503 | continue; |
e9d0b13b | 1504 | } |
6702ed49 | 1505 | |
6b80053d CM |
1506 | cur = btrfs_find_tree_block(root, blocknr, blocksize); |
1507 | if (cur) | |
b9fab919 | 1508 | uptodate = btrfs_buffer_uptodate(cur, gen, 0); |
6b80053d CM |
1509 | else |
1510 | uptodate = 0; | |
5708b959 | 1511 | if (!cur || !uptodate) { |
6702ed49 | 1512 | if (cache_only) { |
6b80053d | 1513 | free_extent_buffer(cur); |
6702ed49 CM |
1514 | continue; |
1515 | } | |
6b80053d CM |
1516 | if (!cur) { |
1517 | cur = read_tree_block(root, blocknr, | |
ca7a79ad | 1518 | blocksize, gen); |
97d9a8a4 TI |
1519 | if (!cur) |
1520 | return -EIO; | |
6b80053d | 1521 | } else if (!uptodate) { |
018642a1 TI |
1522 | err = btrfs_read_buffer(cur, gen); |
1523 | if (err) { | |
1524 | free_extent_buffer(cur); | |
1525 | return err; | |
1526 | } | |
f2183bde | 1527 | } |
6702ed49 | 1528 | } |
e9d0b13b | 1529 | if (search_start == 0) |
6b80053d | 1530 | search_start = last_block; |
e9d0b13b | 1531 | |
e7a84565 | 1532 | btrfs_tree_lock(cur); |
b4ce94de | 1533 | btrfs_set_lock_blocking(cur); |
6b80053d | 1534 | err = __btrfs_cow_block(trans, root, cur, parent, i, |
e7a84565 | 1535 | &cur, search_start, |
6b80053d | 1536 | min(16 * blocksize, |
9fa8cfe7 | 1537 | (end_slot - i) * blocksize)); |
252c38f0 | 1538 | if (err) { |
e7a84565 | 1539 | btrfs_tree_unlock(cur); |
6b80053d | 1540 | free_extent_buffer(cur); |
6702ed49 | 1541 | break; |
252c38f0 | 1542 | } |
e7a84565 CM |
1543 | search_start = cur->start; |
1544 | last_block = cur->start; | |
f2183bde | 1545 | *last_ret = search_start; |
e7a84565 CM |
1546 | btrfs_tree_unlock(cur); |
1547 | free_extent_buffer(cur); | |
6702ed49 CM |
1548 | } |
1549 | return err; | |
1550 | } | |
1551 | ||
74123bd7 CM |
1552 | /* |
1553 | * The leaf data grows from end-to-front in the node. | |
1554 | * this returns the address of the start of the last item, | |
1555 | * which is the stop of the leaf data stack | |
1556 | */ | |
123abc88 | 1557 | static inline unsigned int leaf_data_end(struct btrfs_root *root, |
5f39d397 | 1558 | struct extent_buffer *leaf) |
be0e5c09 | 1559 | { |
5f39d397 | 1560 | u32 nr = btrfs_header_nritems(leaf); |
be0e5c09 | 1561 | if (nr == 0) |
123abc88 | 1562 | return BTRFS_LEAF_DATA_SIZE(root); |
5f39d397 | 1563 | return btrfs_item_offset_nr(leaf, nr - 1); |
be0e5c09 CM |
1564 | } |
1565 | ||
aa5d6bed | 1566 | |
74123bd7 | 1567 | /* |
5f39d397 CM |
1568 | * search for key in the extent_buffer. The items start at offset p, |
1569 | * and they are item_size apart. There are 'max' items in p. | |
1570 | * | |
74123bd7 CM |
1571 | * the slot in the array is returned via slot, and it points to |
1572 | * the place where you would insert key if it is not found in | |
1573 | * the array. | |
1574 | * | |
1575 | * slot may point to max if the key is bigger than all of the keys | |
1576 | */ | |
e02119d5 CM |
1577 | static noinline int generic_bin_search(struct extent_buffer *eb, |
1578 | unsigned long p, | |
1579 | int item_size, struct btrfs_key *key, | |
1580 | int max, int *slot) | |
be0e5c09 CM |
1581 | { |
1582 | int low = 0; | |
1583 | int high = max; | |
1584 | int mid; | |
1585 | int ret; | |
479965d6 | 1586 | struct btrfs_disk_key *tmp = NULL; |
5f39d397 CM |
1587 | struct btrfs_disk_key unaligned; |
1588 | unsigned long offset; | |
5f39d397 CM |
1589 | char *kaddr = NULL; |
1590 | unsigned long map_start = 0; | |
1591 | unsigned long map_len = 0; | |
479965d6 | 1592 | int err; |
be0e5c09 | 1593 | |
d397712b | 1594 | while (low < high) { |
be0e5c09 | 1595 | mid = (low + high) / 2; |
5f39d397 CM |
1596 | offset = p + mid * item_size; |
1597 | ||
a6591715 | 1598 | if (!kaddr || offset < map_start || |
5f39d397 CM |
1599 | (offset + sizeof(struct btrfs_disk_key)) > |
1600 | map_start + map_len) { | |
934d375b CM |
1601 | |
1602 | err = map_private_extent_buffer(eb, offset, | |
479965d6 | 1603 | sizeof(struct btrfs_disk_key), |
a6591715 | 1604 | &kaddr, &map_start, &map_len); |
479965d6 CM |
1605 | |
1606 | if (!err) { | |
1607 | tmp = (struct btrfs_disk_key *)(kaddr + offset - | |
1608 | map_start); | |
1609 | } else { | |
1610 | read_extent_buffer(eb, &unaligned, | |
1611 | offset, sizeof(unaligned)); | |
1612 | tmp = &unaligned; | |
1613 | } | |
5f39d397 | 1614 | |
5f39d397 CM |
1615 | } else { |
1616 | tmp = (struct btrfs_disk_key *)(kaddr + offset - | |
1617 | map_start); | |
1618 | } | |
be0e5c09 CM |
1619 | ret = comp_keys(tmp, key); |
1620 | ||
1621 | if (ret < 0) | |
1622 | low = mid + 1; | |
1623 | else if (ret > 0) | |
1624 | high = mid; | |
1625 | else { | |
1626 | *slot = mid; | |
1627 | return 0; | |
1628 | } | |
1629 | } | |
1630 | *slot = low; | |
1631 | return 1; | |
1632 | } | |
1633 | ||
97571fd0 CM |
1634 | /* |
1635 | * simple bin_search frontend that does the right thing for | |
1636 | * leaves vs nodes | |
1637 | */ | |
5f39d397 CM |
1638 | static int bin_search(struct extent_buffer *eb, struct btrfs_key *key, |
1639 | int level, int *slot) | |
be0e5c09 | 1640 | { |
f775738f | 1641 | if (level == 0) |
5f39d397 CM |
1642 | return generic_bin_search(eb, |
1643 | offsetof(struct btrfs_leaf, items), | |
0783fcfc | 1644 | sizeof(struct btrfs_item), |
5f39d397 | 1645 | key, btrfs_header_nritems(eb), |
7518a238 | 1646 | slot); |
f775738f | 1647 | else |
5f39d397 CM |
1648 | return generic_bin_search(eb, |
1649 | offsetof(struct btrfs_node, ptrs), | |
123abc88 | 1650 | sizeof(struct btrfs_key_ptr), |
5f39d397 | 1651 | key, btrfs_header_nritems(eb), |
7518a238 | 1652 | slot); |
be0e5c09 CM |
1653 | } |
1654 | ||
5d4f98a2 YZ |
1655 | int btrfs_bin_search(struct extent_buffer *eb, struct btrfs_key *key, |
1656 | int level, int *slot) | |
1657 | { | |
1658 | return bin_search(eb, key, level, slot); | |
1659 | } | |
1660 | ||
f0486c68 YZ |
1661 | static void root_add_used(struct btrfs_root *root, u32 size) |
1662 | { | |
1663 | spin_lock(&root->accounting_lock); | |
1664 | btrfs_set_root_used(&root->root_item, | |
1665 | btrfs_root_used(&root->root_item) + size); | |
1666 | spin_unlock(&root->accounting_lock); | |
1667 | } | |
1668 | ||
1669 | static void root_sub_used(struct btrfs_root *root, u32 size) | |
1670 | { | |
1671 | spin_lock(&root->accounting_lock); | |
1672 | btrfs_set_root_used(&root->root_item, | |
1673 | btrfs_root_used(&root->root_item) - size); | |
1674 | spin_unlock(&root->accounting_lock); | |
1675 | } | |
1676 | ||
d352ac68 CM |
1677 | /* given a node and slot number, this reads the blocks it points to. The |
1678 | * extent buffer is returned with a reference taken (but unlocked). | |
1679 | * NULL is returned on error. | |
1680 | */ | |
e02119d5 | 1681 | static noinline struct extent_buffer *read_node_slot(struct btrfs_root *root, |
5f39d397 | 1682 | struct extent_buffer *parent, int slot) |
bb803951 | 1683 | { |
ca7a79ad | 1684 | int level = btrfs_header_level(parent); |
bb803951 CM |
1685 | if (slot < 0) |
1686 | return NULL; | |
5f39d397 | 1687 | if (slot >= btrfs_header_nritems(parent)) |
bb803951 | 1688 | return NULL; |
ca7a79ad CM |
1689 | |
1690 | BUG_ON(level == 0); | |
1691 | ||
db94535d | 1692 | return read_tree_block(root, btrfs_node_blockptr(parent, slot), |
ca7a79ad CM |
1693 | btrfs_level_size(root, level - 1), |
1694 | btrfs_node_ptr_generation(parent, slot)); | |
bb803951 CM |
1695 | } |
1696 | ||
d352ac68 CM |
1697 | /* |
1698 | * node level balancing, used to make sure nodes are in proper order for | |
1699 | * item deletion. We balance from the top down, so we have to make sure | |
1700 | * that a deletion won't leave an node completely empty later on. | |
1701 | */ | |
e02119d5 | 1702 | static noinline int balance_level(struct btrfs_trans_handle *trans, |
98ed5174 CM |
1703 | struct btrfs_root *root, |
1704 | struct btrfs_path *path, int level) | |
bb803951 | 1705 | { |
5f39d397 CM |
1706 | struct extent_buffer *right = NULL; |
1707 | struct extent_buffer *mid; | |
1708 | struct extent_buffer *left = NULL; | |
1709 | struct extent_buffer *parent = NULL; | |
bb803951 CM |
1710 | int ret = 0; |
1711 | int wret; | |
1712 | int pslot; | |
bb803951 | 1713 | int orig_slot = path->slots[level]; |
79f95c82 | 1714 | u64 orig_ptr; |
bb803951 CM |
1715 | |
1716 | if (level == 0) | |
1717 | return 0; | |
1718 | ||
5f39d397 | 1719 | mid = path->nodes[level]; |
b4ce94de | 1720 | |
bd681513 CM |
1721 | WARN_ON(path->locks[level] != BTRFS_WRITE_LOCK && |
1722 | path->locks[level] != BTRFS_WRITE_LOCK_BLOCKING); | |
7bb86316 CM |
1723 | WARN_ON(btrfs_header_generation(mid) != trans->transid); |
1724 | ||
1d4f8a0c | 1725 | orig_ptr = btrfs_node_blockptr(mid, orig_slot); |
79f95c82 | 1726 | |
a05a9bb1 | 1727 | if (level < BTRFS_MAX_LEVEL - 1) { |
5f39d397 | 1728 | parent = path->nodes[level + 1]; |
a05a9bb1 LZ |
1729 | pslot = path->slots[level + 1]; |
1730 | } | |
bb803951 | 1731 | |
40689478 CM |
1732 | /* |
1733 | * deal with the case where there is only one pointer in the root | |
1734 | * by promoting the node below to a root | |
1735 | */ | |
5f39d397 CM |
1736 | if (!parent) { |
1737 | struct extent_buffer *child; | |
bb803951 | 1738 | |
5f39d397 | 1739 | if (btrfs_header_nritems(mid) != 1) |
bb803951 CM |
1740 | return 0; |
1741 | ||
1742 | /* promote the child to a root */ | |
5f39d397 | 1743 | child = read_node_slot(root, mid, 0); |
305a26af MF |
1744 | if (!child) { |
1745 | ret = -EROFS; | |
1746 | btrfs_std_error(root->fs_info, ret); | |
1747 | goto enospc; | |
1748 | } | |
1749 | ||
925baedd | 1750 | btrfs_tree_lock(child); |
b4ce94de | 1751 | btrfs_set_lock_blocking(child); |
9fa8cfe7 | 1752 | ret = btrfs_cow_block(trans, root, child, mid, 0, &child); |
f0486c68 YZ |
1753 | if (ret) { |
1754 | btrfs_tree_unlock(child); | |
1755 | free_extent_buffer(child); | |
1756 | goto enospc; | |
1757 | } | |
2f375ab9 | 1758 | |
ba1bfbd5 | 1759 | tree_mod_log_free_eb(root->fs_info, root->node); |
f230475e | 1760 | tree_mod_log_set_root_pointer(root, child); |
240f62c8 | 1761 | rcu_assign_pointer(root->node, child); |
925baedd | 1762 | |
0b86a832 | 1763 | add_root_to_dirty_list(root); |
925baedd | 1764 | btrfs_tree_unlock(child); |
b4ce94de | 1765 | |
925baedd | 1766 | path->locks[level] = 0; |
bb803951 | 1767 | path->nodes[level] = NULL; |
5f39d397 | 1768 | clean_tree_block(trans, root, mid); |
925baedd | 1769 | btrfs_tree_unlock(mid); |
bb803951 | 1770 | /* once for the path */ |
5f39d397 | 1771 | free_extent_buffer(mid); |
f0486c68 YZ |
1772 | |
1773 | root_sub_used(root, mid->len); | |
5581a51a | 1774 | btrfs_free_tree_block(trans, root, mid, 0, 1); |
bb803951 | 1775 | /* once for the root ptr */ |
3083ee2e | 1776 | free_extent_buffer_stale(mid); |
f0486c68 | 1777 | return 0; |
bb803951 | 1778 | } |
5f39d397 | 1779 | if (btrfs_header_nritems(mid) > |
123abc88 | 1780 | BTRFS_NODEPTRS_PER_BLOCK(root) / 4) |
bb803951 CM |
1781 | return 0; |
1782 | ||
5f39d397 CM |
1783 | left = read_node_slot(root, parent, pslot - 1); |
1784 | if (left) { | |
925baedd | 1785 | btrfs_tree_lock(left); |
b4ce94de | 1786 | btrfs_set_lock_blocking(left); |
5f39d397 | 1787 | wret = btrfs_cow_block(trans, root, left, |
9fa8cfe7 | 1788 | parent, pslot - 1, &left); |
54aa1f4d CM |
1789 | if (wret) { |
1790 | ret = wret; | |
1791 | goto enospc; | |
1792 | } | |
2cc58cf2 | 1793 | } |
5f39d397 CM |
1794 | right = read_node_slot(root, parent, pslot + 1); |
1795 | if (right) { | |
925baedd | 1796 | btrfs_tree_lock(right); |
b4ce94de | 1797 | btrfs_set_lock_blocking(right); |
5f39d397 | 1798 | wret = btrfs_cow_block(trans, root, right, |
9fa8cfe7 | 1799 | parent, pslot + 1, &right); |
2cc58cf2 CM |
1800 | if (wret) { |
1801 | ret = wret; | |
1802 | goto enospc; | |
1803 | } | |
1804 | } | |
1805 | ||
1806 | /* first, try to make some room in the middle buffer */ | |
5f39d397 CM |
1807 | if (left) { |
1808 | orig_slot += btrfs_header_nritems(left); | |
bce4eae9 | 1809 | wret = push_node_left(trans, root, left, mid, 1); |
79f95c82 CM |
1810 | if (wret < 0) |
1811 | ret = wret; | |
bb803951 | 1812 | } |
79f95c82 CM |
1813 | |
1814 | /* | |
1815 | * then try to empty the right most buffer into the middle | |
1816 | */ | |
5f39d397 | 1817 | if (right) { |
971a1f66 | 1818 | wret = push_node_left(trans, root, mid, right, 1); |
54aa1f4d | 1819 | if (wret < 0 && wret != -ENOSPC) |
79f95c82 | 1820 | ret = wret; |
5f39d397 | 1821 | if (btrfs_header_nritems(right) == 0) { |
5f39d397 | 1822 | clean_tree_block(trans, root, right); |
925baedd | 1823 | btrfs_tree_unlock(right); |
0e411ece | 1824 | del_ptr(trans, root, path, level + 1, pslot + 1); |
f0486c68 | 1825 | root_sub_used(root, right->len); |
5581a51a | 1826 | btrfs_free_tree_block(trans, root, right, 0, 1); |
3083ee2e | 1827 | free_extent_buffer_stale(right); |
f0486c68 | 1828 | right = NULL; |
bb803951 | 1829 | } else { |
5f39d397 CM |
1830 | struct btrfs_disk_key right_key; |
1831 | btrfs_node_key(right, &right_key, 0); | |
f230475e | 1832 | tree_mod_log_set_node_key(root->fs_info, parent, |
32adf090 | 1833 | pslot + 1, 0); |
5f39d397 CM |
1834 | btrfs_set_node_key(parent, &right_key, pslot + 1); |
1835 | btrfs_mark_buffer_dirty(parent); | |
bb803951 CM |
1836 | } |
1837 | } | |
5f39d397 | 1838 | if (btrfs_header_nritems(mid) == 1) { |
79f95c82 CM |
1839 | /* |
1840 | * we're not allowed to leave a node with one item in the | |
1841 | * tree during a delete. A deletion from lower in the tree | |
1842 | * could try to delete the only pointer in this node. | |
1843 | * So, pull some keys from the left. | |
1844 | * There has to be a left pointer at this point because | |
1845 | * otherwise we would have pulled some pointers from the | |
1846 | * right | |
1847 | */ | |
305a26af MF |
1848 | if (!left) { |
1849 | ret = -EROFS; | |
1850 | btrfs_std_error(root->fs_info, ret); | |
1851 | goto enospc; | |
1852 | } | |
5f39d397 | 1853 | wret = balance_node_right(trans, root, mid, left); |
54aa1f4d | 1854 | if (wret < 0) { |
79f95c82 | 1855 | ret = wret; |
54aa1f4d CM |
1856 | goto enospc; |
1857 | } | |
bce4eae9 CM |
1858 | if (wret == 1) { |
1859 | wret = push_node_left(trans, root, left, mid, 1); | |
1860 | if (wret < 0) | |
1861 | ret = wret; | |
1862 | } | |
79f95c82 CM |
1863 | BUG_ON(wret == 1); |
1864 | } | |
5f39d397 | 1865 | if (btrfs_header_nritems(mid) == 0) { |
5f39d397 | 1866 | clean_tree_block(trans, root, mid); |
925baedd | 1867 | btrfs_tree_unlock(mid); |
0e411ece | 1868 | del_ptr(trans, root, path, level + 1, pslot); |
f0486c68 | 1869 | root_sub_used(root, mid->len); |
5581a51a | 1870 | btrfs_free_tree_block(trans, root, mid, 0, 1); |
3083ee2e | 1871 | free_extent_buffer_stale(mid); |
f0486c68 | 1872 | mid = NULL; |
79f95c82 CM |
1873 | } else { |
1874 | /* update the parent key to reflect our changes */ | |
5f39d397 CM |
1875 | struct btrfs_disk_key mid_key; |
1876 | btrfs_node_key(mid, &mid_key, 0); | |
32adf090 | 1877 | tree_mod_log_set_node_key(root->fs_info, parent, |
f230475e | 1878 | pslot, 0); |
5f39d397 CM |
1879 | btrfs_set_node_key(parent, &mid_key, pslot); |
1880 | btrfs_mark_buffer_dirty(parent); | |
79f95c82 | 1881 | } |
bb803951 | 1882 | |
79f95c82 | 1883 | /* update the path */ |
5f39d397 CM |
1884 | if (left) { |
1885 | if (btrfs_header_nritems(left) > orig_slot) { | |
1886 | extent_buffer_get(left); | |
925baedd | 1887 | /* left was locked after cow */ |
5f39d397 | 1888 | path->nodes[level] = left; |
bb803951 CM |
1889 | path->slots[level + 1] -= 1; |
1890 | path->slots[level] = orig_slot; | |
925baedd CM |
1891 | if (mid) { |
1892 | btrfs_tree_unlock(mid); | |
5f39d397 | 1893 | free_extent_buffer(mid); |
925baedd | 1894 | } |
bb803951 | 1895 | } else { |
5f39d397 | 1896 | orig_slot -= btrfs_header_nritems(left); |
bb803951 CM |
1897 | path->slots[level] = orig_slot; |
1898 | } | |
1899 | } | |
79f95c82 | 1900 | /* double check we haven't messed things up */ |
e20d96d6 | 1901 | if (orig_ptr != |
5f39d397 | 1902 | btrfs_node_blockptr(path->nodes[level], path->slots[level])) |
79f95c82 | 1903 | BUG(); |
54aa1f4d | 1904 | enospc: |
925baedd CM |
1905 | if (right) { |
1906 | btrfs_tree_unlock(right); | |
5f39d397 | 1907 | free_extent_buffer(right); |
925baedd CM |
1908 | } |
1909 | if (left) { | |
1910 | if (path->nodes[level] != left) | |
1911 | btrfs_tree_unlock(left); | |
5f39d397 | 1912 | free_extent_buffer(left); |
925baedd | 1913 | } |
bb803951 CM |
1914 | return ret; |
1915 | } | |
1916 | ||
d352ac68 CM |
1917 | /* Node balancing for insertion. Here we only split or push nodes around |
1918 | * when they are completely full. This is also done top down, so we | |
1919 | * have to be pessimistic. | |
1920 | */ | |
d397712b | 1921 | static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans, |
98ed5174 CM |
1922 | struct btrfs_root *root, |
1923 | struct btrfs_path *path, int level) | |
e66f709b | 1924 | { |
5f39d397 CM |
1925 | struct extent_buffer *right = NULL; |
1926 | struct extent_buffer *mid; | |
1927 | struct extent_buffer *left = NULL; | |
1928 | struct extent_buffer *parent = NULL; | |
e66f709b CM |
1929 | int ret = 0; |
1930 | int wret; | |
1931 | int pslot; | |
1932 | int orig_slot = path->slots[level]; | |
e66f709b CM |
1933 | |
1934 | if (level == 0) | |
1935 | return 1; | |
1936 | ||
5f39d397 | 1937 | mid = path->nodes[level]; |
7bb86316 | 1938 | WARN_ON(btrfs_header_generation(mid) != trans->transid); |
e66f709b | 1939 | |
a05a9bb1 | 1940 | if (level < BTRFS_MAX_LEVEL - 1) { |
5f39d397 | 1941 | parent = path->nodes[level + 1]; |
a05a9bb1 LZ |
1942 | pslot = path->slots[level + 1]; |
1943 | } | |
e66f709b | 1944 | |
5f39d397 | 1945 | if (!parent) |
e66f709b | 1946 | return 1; |
e66f709b | 1947 | |
5f39d397 | 1948 | left = read_node_slot(root, parent, pslot - 1); |
e66f709b CM |
1949 | |
1950 | /* first, try to make some room in the middle buffer */ | |
5f39d397 | 1951 | if (left) { |
e66f709b | 1952 | u32 left_nr; |
925baedd CM |
1953 | |
1954 | btrfs_tree_lock(left); | |
b4ce94de CM |
1955 | btrfs_set_lock_blocking(left); |
1956 | ||
5f39d397 | 1957 | left_nr = btrfs_header_nritems(left); |
33ade1f8 CM |
1958 | if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) { |
1959 | wret = 1; | |
1960 | } else { | |
5f39d397 | 1961 | ret = btrfs_cow_block(trans, root, left, parent, |
9fa8cfe7 | 1962 | pslot - 1, &left); |
54aa1f4d CM |
1963 | if (ret) |
1964 | wret = 1; | |
1965 | else { | |
54aa1f4d | 1966 | wret = push_node_left(trans, root, |
971a1f66 | 1967 | left, mid, 0); |
54aa1f4d | 1968 | } |
33ade1f8 | 1969 | } |
e66f709b CM |
1970 | if (wret < 0) |
1971 | ret = wret; | |
1972 | if (wret == 0) { | |
5f39d397 | 1973 | struct btrfs_disk_key disk_key; |
e66f709b | 1974 | orig_slot += left_nr; |
5f39d397 | 1975 | btrfs_node_key(mid, &disk_key, 0); |
f230475e | 1976 | tree_mod_log_set_node_key(root->fs_info, parent, |
32adf090 | 1977 | pslot, 0); |
5f39d397 CM |
1978 | btrfs_set_node_key(parent, &disk_key, pslot); |
1979 | btrfs_mark_buffer_dirty(parent); | |
1980 | if (btrfs_header_nritems(left) > orig_slot) { | |
1981 | path->nodes[level] = left; | |
e66f709b CM |
1982 | path->slots[level + 1] -= 1; |
1983 | path->slots[level] = orig_slot; | |
925baedd | 1984 | btrfs_tree_unlock(mid); |
5f39d397 | 1985 | free_extent_buffer(mid); |
e66f709b CM |
1986 | } else { |
1987 | orig_slot -= | |
5f39d397 | 1988 | btrfs_header_nritems(left); |
e66f709b | 1989 | path->slots[level] = orig_slot; |
925baedd | 1990 | btrfs_tree_unlock(left); |
5f39d397 | 1991 | free_extent_buffer(left); |
e66f709b | 1992 | } |
e66f709b CM |
1993 | return 0; |
1994 | } | |
925baedd | 1995 | btrfs_tree_unlock(left); |
5f39d397 | 1996 | free_extent_buffer(left); |
e66f709b | 1997 | } |
925baedd | 1998 | right = read_node_slot(root, parent, pslot + 1); |
e66f709b CM |
1999 | |
2000 | /* | |
2001 | * then try to empty the right most buffer into the middle | |
2002 | */ | |
5f39d397 | 2003 | if (right) { |
33ade1f8 | 2004 | u32 right_nr; |
b4ce94de | 2005 | |
925baedd | 2006 | btrfs_tree_lock(right); |
b4ce94de CM |
2007 | btrfs_set_lock_blocking(right); |
2008 | ||
5f39d397 | 2009 | right_nr = btrfs_header_nritems(right); |
33ade1f8 CM |
2010 | if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) { |
2011 | wret = 1; | |
2012 | } else { | |
5f39d397 CM |
2013 | ret = btrfs_cow_block(trans, root, right, |
2014 | parent, pslot + 1, | |
9fa8cfe7 | 2015 | &right); |
54aa1f4d CM |
2016 | if (ret) |
2017 | wret = 1; | |
2018 | else { | |
54aa1f4d | 2019 | wret = balance_node_right(trans, root, |
5f39d397 | 2020 | right, mid); |
54aa1f4d | 2021 | } |
33ade1f8 | 2022 | } |
e66f709b CM |
2023 | if (wret < 0) |
2024 | ret = wret; | |
2025 | if (wret == 0) { | |
5f39d397 CM |
2026 | struct btrfs_disk_key disk_key; |
2027 | ||
2028 | btrfs_node_key(right, &disk_key, 0); | |
f230475e | 2029 | tree_mod_log_set_node_key(root->fs_info, parent, |
32adf090 | 2030 | pslot + 1, 0); |
5f39d397 CM |
2031 | btrfs_set_node_key(parent, &disk_key, pslot + 1); |
2032 | btrfs_mark_buffer_dirty(parent); | |
2033 | ||
2034 | if (btrfs_header_nritems(mid) <= orig_slot) { | |
2035 | path->nodes[level] = right; | |
e66f709b CM |
2036 | path->slots[level + 1] += 1; |
2037 | path->slots[level] = orig_slot - | |
5f39d397 | 2038 | btrfs_header_nritems(mid); |
925baedd | 2039 | btrfs_tree_unlock(mid); |
5f39d397 | 2040 | free_extent_buffer(mid); |
e66f709b | 2041 | } else { |
925baedd | 2042 | btrfs_tree_unlock(right); |
5f39d397 | 2043 | free_extent_buffer(right); |
e66f709b | 2044 | } |
e66f709b CM |
2045 | return 0; |
2046 | } | |
925baedd | 2047 | btrfs_tree_unlock(right); |
5f39d397 | 2048 | free_extent_buffer(right); |
e66f709b | 2049 | } |
e66f709b CM |
2050 | return 1; |
2051 | } | |
2052 | ||
3c69faec | 2053 | /* |
d352ac68 CM |
2054 | * readahead one full node of leaves, finding things that are close |
2055 | * to the block in 'slot', and triggering ra on them. | |
3c69faec | 2056 | */ |
c8c42864 CM |
2057 | static void reada_for_search(struct btrfs_root *root, |
2058 | struct btrfs_path *path, | |
2059 | int level, int slot, u64 objectid) | |
3c69faec | 2060 | { |
5f39d397 | 2061 | struct extent_buffer *node; |
01f46658 | 2062 | struct btrfs_disk_key disk_key; |
3c69faec | 2063 | u32 nritems; |
3c69faec | 2064 | u64 search; |
a7175319 | 2065 | u64 target; |
6b80053d | 2066 | u64 nread = 0; |
cb25c2ea | 2067 | u64 gen; |
3c69faec | 2068 | int direction = path->reada; |
5f39d397 | 2069 | struct extent_buffer *eb; |
6b80053d CM |
2070 | u32 nr; |
2071 | u32 blocksize; | |
2072 | u32 nscan = 0; | |
db94535d | 2073 | |
a6b6e75e | 2074 | if (level != 1) |
6702ed49 CM |
2075 | return; |
2076 | ||
2077 | if (!path->nodes[level]) | |
3c69faec CM |
2078 | return; |
2079 | ||
5f39d397 | 2080 | node = path->nodes[level]; |
925baedd | 2081 | |
3c69faec | 2082 | search = btrfs_node_blockptr(node, slot); |
6b80053d CM |
2083 | blocksize = btrfs_level_size(root, level - 1); |
2084 | eb = btrfs_find_tree_block(root, search, blocksize); | |
5f39d397 CM |
2085 | if (eb) { |
2086 | free_extent_buffer(eb); | |
3c69faec CM |
2087 | return; |
2088 | } | |
2089 | ||
a7175319 | 2090 | target = search; |
6b80053d | 2091 | |
5f39d397 | 2092 | nritems = btrfs_header_nritems(node); |
6b80053d | 2093 | nr = slot; |
25b8b936 | 2094 | |
d397712b | 2095 | while (1) { |
6b80053d CM |
2096 | if (direction < 0) { |
2097 | if (nr == 0) | |
2098 | break; | |
2099 | nr--; | |
2100 | } else if (direction > 0) { | |
2101 | nr++; | |
2102 | if (nr >= nritems) | |
2103 | break; | |
3c69faec | 2104 | } |
01f46658 CM |
2105 | if (path->reada < 0 && objectid) { |
2106 | btrfs_node_key(node, &disk_key, nr); | |
2107 | if (btrfs_disk_key_objectid(&disk_key) != objectid) | |
2108 | break; | |
2109 | } | |
6b80053d | 2110 | search = btrfs_node_blockptr(node, nr); |
a7175319 CM |
2111 | if ((search <= target && target - search <= 65536) || |
2112 | (search > target && search - target <= 65536)) { | |
cb25c2ea | 2113 | gen = btrfs_node_ptr_generation(node, nr); |
cb25c2ea | 2114 | readahead_tree_block(root, search, blocksize, gen); |
6b80053d CM |
2115 | nread += blocksize; |
2116 | } | |
2117 | nscan++; | |
a7175319 | 2118 | if ((nread > 65536 || nscan > 32)) |
6b80053d | 2119 | break; |
3c69faec CM |
2120 | } |
2121 | } | |
925baedd | 2122 | |
b4ce94de CM |
2123 | /* |
2124 | * returns -EAGAIN if it had to drop the path, or zero if everything was in | |
2125 | * cache | |
2126 | */ | |
2127 | static noinline int reada_for_balance(struct btrfs_root *root, | |
2128 | struct btrfs_path *path, int level) | |
2129 | { | |
2130 | int slot; | |
2131 | int nritems; | |
2132 | struct extent_buffer *parent; | |
2133 | struct extent_buffer *eb; | |
2134 | u64 gen; | |
2135 | u64 block1 = 0; | |
2136 | u64 block2 = 0; | |
2137 | int ret = 0; | |
2138 | int blocksize; | |
2139 | ||
8c594ea8 | 2140 | parent = path->nodes[level + 1]; |
b4ce94de CM |
2141 | if (!parent) |
2142 | return 0; | |
2143 | ||
2144 | nritems = btrfs_header_nritems(parent); | |
8c594ea8 | 2145 | slot = path->slots[level + 1]; |
b4ce94de CM |
2146 | blocksize = btrfs_level_size(root, level); |
2147 | ||
2148 | if (slot > 0) { | |
2149 | block1 = btrfs_node_blockptr(parent, slot - 1); | |
2150 | gen = btrfs_node_ptr_generation(parent, slot - 1); | |
2151 | eb = btrfs_find_tree_block(root, block1, blocksize); | |
b9fab919 CM |
2152 | /* |
2153 | * if we get -eagain from btrfs_buffer_uptodate, we | |
2154 | * don't want to return eagain here. That will loop | |
2155 | * forever | |
2156 | */ | |
2157 | if (eb && btrfs_buffer_uptodate(eb, gen, 1) != 0) | |
b4ce94de CM |
2158 | block1 = 0; |
2159 | free_extent_buffer(eb); | |
2160 | } | |
8c594ea8 | 2161 | if (slot + 1 < nritems) { |
b4ce94de CM |
2162 | block2 = btrfs_node_blockptr(parent, slot + 1); |
2163 | gen = btrfs_node_ptr_generation(parent, slot + 1); | |
2164 | eb = btrfs_find_tree_block(root, block2, blocksize); | |
b9fab919 | 2165 | if (eb && btrfs_buffer_uptodate(eb, gen, 1) != 0) |
b4ce94de CM |
2166 | block2 = 0; |
2167 | free_extent_buffer(eb); | |
2168 | } | |
2169 | if (block1 || block2) { | |
2170 | ret = -EAGAIN; | |
8c594ea8 CM |
2171 | |
2172 | /* release the whole path */ | |
b3b4aa74 | 2173 | btrfs_release_path(path); |
8c594ea8 CM |
2174 | |
2175 | /* read the blocks */ | |
b4ce94de CM |
2176 | if (block1) |
2177 | readahead_tree_block(root, block1, blocksize, 0); | |
2178 | if (block2) | |
2179 | readahead_tree_block(root, block2, blocksize, 0); | |
2180 | ||
2181 | if (block1) { | |
2182 | eb = read_tree_block(root, block1, blocksize, 0); | |
2183 | free_extent_buffer(eb); | |
2184 | } | |
8c594ea8 | 2185 | if (block2) { |
b4ce94de CM |
2186 | eb = read_tree_block(root, block2, blocksize, 0); |
2187 | free_extent_buffer(eb); | |
2188 | } | |
2189 | } | |
2190 | return ret; | |
2191 | } | |
2192 | ||
2193 | ||
d352ac68 | 2194 | /* |
d397712b CM |
2195 | * when we walk down the tree, it is usually safe to unlock the higher layers |
2196 | * in the tree. The exceptions are when our path goes through slot 0, because | |
2197 | * operations on the tree might require changing key pointers higher up in the | |
2198 | * tree. | |
d352ac68 | 2199 | * |
d397712b CM |
2200 | * callers might also have set path->keep_locks, which tells this code to keep |
2201 | * the lock if the path points to the last slot in the block. This is part of | |
2202 | * walking through the tree, and selecting the next slot in the higher block. | |
d352ac68 | 2203 | * |
d397712b CM |
2204 | * lowest_unlock sets the lowest level in the tree we're allowed to unlock. so |
2205 | * if lowest_unlock is 1, level 0 won't be unlocked | |
d352ac68 | 2206 | */ |
e02119d5 | 2207 | static noinline void unlock_up(struct btrfs_path *path, int level, |
f7c79f30 CM |
2208 | int lowest_unlock, int min_write_lock_level, |
2209 | int *write_lock_level) | |
925baedd CM |
2210 | { |
2211 | int i; | |
2212 | int skip_level = level; | |
051e1b9f | 2213 | int no_skips = 0; |
925baedd CM |
2214 | struct extent_buffer *t; |
2215 | ||
d6393786 JB |
2216 | if (path->really_keep_locks) |
2217 | return; | |
2218 | ||
925baedd CM |
2219 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { |
2220 | if (!path->nodes[i]) | |
2221 | break; | |
2222 | if (!path->locks[i]) | |
2223 | break; | |
051e1b9f | 2224 | if (!no_skips && path->slots[i] == 0) { |
925baedd CM |
2225 | skip_level = i + 1; |
2226 | continue; | |
2227 | } | |
051e1b9f | 2228 | if (!no_skips && path->keep_locks) { |
925baedd CM |
2229 | u32 nritems; |
2230 | t = path->nodes[i]; | |
2231 | nritems = btrfs_header_nritems(t); | |
051e1b9f | 2232 | if (nritems < 1 || path->slots[i] >= nritems - 1) { |
925baedd CM |
2233 | skip_level = i + 1; |
2234 | continue; | |
2235 | } | |
2236 | } | |
051e1b9f CM |
2237 | if (skip_level < i && i >= lowest_unlock) |
2238 | no_skips = 1; | |
2239 | ||
925baedd CM |
2240 | t = path->nodes[i]; |
2241 | if (i >= lowest_unlock && i > skip_level && path->locks[i]) { | |
bd681513 | 2242 | btrfs_tree_unlock_rw(t, path->locks[i]); |
925baedd | 2243 | path->locks[i] = 0; |
f7c79f30 CM |
2244 | if (write_lock_level && |
2245 | i > min_write_lock_level && | |
2246 | i <= *write_lock_level) { | |
2247 | *write_lock_level = i - 1; | |
2248 | } | |
925baedd CM |
2249 | } |
2250 | } | |
2251 | } | |
2252 | ||
b4ce94de CM |
2253 | /* |
2254 | * This releases any locks held in the path starting at level and | |
2255 | * going all the way up to the root. | |
2256 | * | |
2257 | * btrfs_search_slot will keep the lock held on higher nodes in a few | |
2258 | * corner cases, such as COW of the block at slot zero in the node. This | |
2259 | * ignores those rules, and it should only be called when there are no | |
2260 | * more updates to be done higher up in the tree. | |
2261 | */ | |
2262 | noinline void btrfs_unlock_up_safe(struct btrfs_path *path, int level) | |
2263 | { | |
2264 | int i; | |
2265 | ||
d6393786 | 2266 | if (path->keep_locks || path->really_keep_locks) |
b4ce94de CM |
2267 | return; |
2268 | ||
2269 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { | |
2270 | if (!path->nodes[i]) | |
12f4dacc | 2271 | continue; |
b4ce94de | 2272 | if (!path->locks[i]) |
12f4dacc | 2273 | continue; |
bd681513 | 2274 | btrfs_tree_unlock_rw(path->nodes[i], path->locks[i]); |
b4ce94de CM |
2275 | path->locks[i] = 0; |
2276 | } | |
2277 | } | |
2278 | ||
c8c42864 CM |
2279 | /* |
2280 | * helper function for btrfs_search_slot. The goal is to find a block | |
2281 | * in cache without setting the path to blocking. If we find the block | |
2282 | * we return zero and the path is unchanged. | |
2283 | * | |
2284 | * If we can't find the block, we set the path blocking and do some | |
2285 | * reada. -EAGAIN is returned and the search must be repeated. | |
2286 | */ | |
2287 | static int | |
2288 | read_block_for_search(struct btrfs_trans_handle *trans, | |
2289 | struct btrfs_root *root, struct btrfs_path *p, | |
2290 | struct extent_buffer **eb_ret, int level, int slot, | |
5d9e75c4 | 2291 | struct btrfs_key *key, u64 time_seq) |
c8c42864 CM |
2292 | { |
2293 | u64 blocknr; | |
2294 | u64 gen; | |
2295 | u32 blocksize; | |
2296 | struct extent_buffer *b = *eb_ret; | |
2297 | struct extent_buffer *tmp; | |
76a05b35 | 2298 | int ret; |
c8c42864 CM |
2299 | |
2300 | blocknr = btrfs_node_blockptr(b, slot); | |
2301 | gen = btrfs_node_ptr_generation(b, slot); | |
2302 | blocksize = btrfs_level_size(root, level - 1); | |
2303 | ||
2304 | tmp = btrfs_find_tree_block(root, blocknr, blocksize); | |
cb44921a | 2305 | if (tmp) { |
b9fab919 CM |
2306 | /* first we do an atomic uptodate check */ |
2307 | if (btrfs_buffer_uptodate(tmp, 0, 1) > 0) { | |
2308 | if (btrfs_buffer_uptodate(tmp, gen, 1) > 0) { | |
cb44921a CM |
2309 | /* |
2310 | * we found an up to date block without | |
2311 | * sleeping, return | |
2312 | * right away | |
2313 | */ | |
2314 | *eb_ret = tmp; | |
2315 | return 0; | |
2316 | } | |
2317 | /* the pages were up to date, but we failed | |
2318 | * the generation number check. Do a full | |
2319 | * read for the generation number that is correct. | |
2320 | * We must do this without dropping locks so | |
2321 | * we can trust our generation number | |
2322 | */ | |
2323 | free_extent_buffer(tmp); | |
bd681513 CM |
2324 | btrfs_set_path_blocking(p); |
2325 | ||
b9fab919 | 2326 | /* now we're allowed to do a blocking uptodate check */ |
cb44921a | 2327 | tmp = read_tree_block(root, blocknr, blocksize, gen); |
b9fab919 | 2328 | if (tmp && btrfs_buffer_uptodate(tmp, gen, 0) > 0) { |
cb44921a CM |
2329 | *eb_ret = tmp; |
2330 | return 0; | |
2331 | } | |
2332 | free_extent_buffer(tmp); | |
b3b4aa74 | 2333 | btrfs_release_path(p); |
cb44921a CM |
2334 | return -EIO; |
2335 | } | |
c8c42864 CM |
2336 | } |
2337 | ||
2338 | /* | |
2339 | * reduce lock contention at high levels | |
2340 | * of the btree by dropping locks before | |
76a05b35 CM |
2341 | * we read. Don't release the lock on the current |
2342 | * level because we need to walk this node to figure | |
2343 | * out which blocks to read. | |
c8c42864 | 2344 | */ |
8c594ea8 CM |
2345 | btrfs_unlock_up_safe(p, level + 1); |
2346 | btrfs_set_path_blocking(p); | |
2347 | ||
cb44921a | 2348 | free_extent_buffer(tmp); |
c8c42864 CM |
2349 | if (p->reada) |
2350 | reada_for_search(root, p, level, slot, key->objectid); | |
2351 | ||
b3b4aa74 | 2352 | btrfs_release_path(p); |
76a05b35 CM |
2353 | |
2354 | ret = -EAGAIN; | |
5bdd3536 | 2355 | tmp = read_tree_block(root, blocknr, blocksize, 0); |
76a05b35 CM |
2356 | if (tmp) { |
2357 | /* | |
2358 | * If the read above didn't mark this buffer up to date, | |
2359 | * it will never end up being up to date. Set ret to EIO now | |
2360 | * and give up so that our caller doesn't loop forever | |
2361 | * on our EAGAINs. | |
2362 | */ | |
b9fab919 | 2363 | if (!btrfs_buffer_uptodate(tmp, 0, 0)) |
76a05b35 | 2364 | ret = -EIO; |
c8c42864 | 2365 | free_extent_buffer(tmp); |
76a05b35 CM |
2366 | } |
2367 | return ret; | |
c8c42864 CM |
2368 | } |
2369 | ||
2370 | /* | |
2371 | * helper function for btrfs_search_slot. This does all of the checks | |
2372 | * for node-level blocks and does any balancing required based on | |
2373 | * the ins_len. | |
2374 | * | |
2375 | * If no extra work was required, zero is returned. If we had to | |
2376 | * drop the path, -EAGAIN is returned and btrfs_search_slot must | |
2377 | * start over | |
2378 | */ | |
2379 | static int | |
2380 | setup_nodes_for_search(struct btrfs_trans_handle *trans, | |
2381 | struct btrfs_root *root, struct btrfs_path *p, | |
bd681513 CM |
2382 | struct extent_buffer *b, int level, int ins_len, |
2383 | int *write_lock_level) | |
c8c42864 CM |
2384 | { |
2385 | int ret; | |
2386 | if ((p->search_for_split || ins_len > 0) && btrfs_header_nritems(b) >= | |
2387 | BTRFS_NODEPTRS_PER_BLOCK(root) - 3) { | |
2388 | int sret; | |
2389 | ||
bd681513 CM |
2390 | if (*write_lock_level < level + 1) { |
2391 | *write_lock_level = level + 1; | |
2392 | btrfs_release_path(p); | |
2393 | goto again; | |
2394 | } | |
2395 | ||
c8c42864 CM |
2396 | sret = reada_for_balance(root, p, level); |
2397 | if (sret) | |
2398 | goto again; | |
2399 | ||
2400 | btrfs_set_path_blocking(p); | |
2401 | sret = split_node(trans, root, p, level); | |
bd681513 | 2402 | btrfs_clear_path_blocking(p, NULL, 0); |
c8c42864 CM |
2403 | |
2404 | BUG_ON(sret > 0); | |
2405 | if (sret) { | |
2406 | ret = sret; | |
2407 | goto done; | |
2408 | } | |
2409 | b = p->nodes[level]; | |
2410 | } else if (ins_len < 0 && btrfs_header_nritems(b) < | |
cfbb9308 | 2411 | BTRFS_NODEPTRS_PER_BLOCK(root) / 2) { |
c8c42864 CM |
2412 | int sret; |
2413 | ||
bd681513 CM |
2414 | if (*write_lock_level < level + 1) { |
2415 | *write_lock_level = level + 1; | |
2416 | btrfs_release_path(p); | |
2417 | goto again; | |
2418 | } | |
2419 | ||
c8c42864 CM |
2420 | sret = reada_for_balance(root, p, level); |
2421 | if (sret) | |
2422 | goto again; | |
2423 | ||
2424 | btrfs_set_path_blocking(p); | |
2425 | sret = balance_level(trans, root, p, level); | |
bd681513 | 2426 | btrfs_clear_path_blocking(p, NULL, 0); |
c8c42864 CM |
2427 | |
2428 | if (sret) { | |
2429 | ret = sret; | |
2430 | goto done; | |
2431 | } | |
2432 | b = p->nodes[level]; | |
2433 | if (!b) { | |
b3b4aa74 | 2434 | btrfs_release_path(p); |
c8c42864 CM |
2435 | goto again; |
2436 | } | |
2437 | BUG_ON(btrfs_header_nritems(b) == 1); | |
2438 | } | |
2439 | return 0; | |
2440 | ||
2441 | again: | |
2442 | ret = -EAGAIN; | |
2443 | done: | |
2444 | return ret; | |
2445 | } | |
2446 | ||
74123bd7 CM |
2447 | /* |
2448 | * look for key in the tree. path is filled in with nodes along the way | |
2449 | * if key is found, we return zero and you can find the item in the leaf | |
2450 | * level of the path (level 0) | |
2451 | * | |
2452 | * If the key isn't found, the path points to the slot where it should | |
aa5d6bed CM |
2453 | * be inserted, and 1 is returned. If there are other errors during the |
2454 | * search a negative error number is returned. | |
97571fd0 CM |
2455 | * |
2456 | * if ins_len > 0, nodes and leaves will be split as we walk down the | |
2457 | * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if | |
2458 | * possible) | |
74123bd7 | 2459 | */ |
e089f05c CM |
2460 | int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root |
2461 | *root, struct btrfs_key *key, struct btrfs_path *p, int | |
2462 | ins_len, int cow) | |
be0e5c09 | 2463 | { |
5f39d397 | 2464 | struct extent_buffer *b; |
be0e5c09 CM |
2465 | int slot; |
2466 | int ret; | |
33c66f43 | 2467 | int err; |
be0e5c09 | 2468 | int level; |
925baedd | 2469 | int lowest_unlock = 1; |
bd681513 CM |
2470 | int root_lock; |
2471 | /* everything at write_lock_level or lower must be write locked */ | |
2472 | int write_lock_level = 0; | |
9f3a7427 | 2473 | u8 lowest_level = 0; |
f7c79f30 | 2474 | int min_write_lock_level; |
9f3a7427 | 2475 | |
6702ed49 | 2476 | lowest_level = p->lowest_level; |
323ac95b | 2477 | WARN_ON(lowest_level && ins_len > 0); |
22b0ebda | 2478 | WARN_ON(p->nodes[0] != NULL); |
25179201 | 2479 | |
bd681513 | 2480 | if (ins_len < 0) { |
925baedd | 2481 | lowest_unlock = 2; |
65b51a00 | 2482 | |
bd681513 CM |
2483 | /* when we are removing items, we might have to go up to level |
2484 | * two as we update tree pointers Make sure we keep write | |
2485 | * for those levels as well | |
2486 | */ | |
2487 | write_lock_level = 2; | |
2488 | } else if (ins_len > 0) { | |
2489 | /* | |
2490 | * for inserting items, make sure we have a write lock on | |
2491 | * level 1 so we can update keys | |
2492 | */ | |
2493 | write_lock_level = 1; | |
2494 | } | |
2495 | ||
2496 | if (!cow) | |
2497 | write_lock_level = -1; | |
2498 | ||
d6393786 | 2499 | if (cow && (p->really_keep_locks || p->keep_locks || p->lowest_level)) |
bd681513 CM |
2500 | write_lock_level = BTRFS_MAX_LEVEL; |
2501 | ||
f7c79f30 CM |
2502 | min_write_lock_level = write_lock_level; |
2503 | ||
bb803951 | 2504 | again: |
bd681513 CM |
2505 | /* |
2506 | * we try very hard to do read locks on the root | |
2507 | */ | |
2508 | root_lock = BTRFS_READ_LOCK; | |
2509 | level = 0; | |
5d4f98a2 | 2510 | if (p->search_commit_root) { |
bd681513 CM |
2511 | /* |
2512 | * the commit roots are read only | |
2513 | * so we always do read locks | |
2514 | */ | |
5d4f98a2 YZ |
2515 | b = root->commit_root; |
2516 | extent_buffer_get(b); | |
bd681513 | 2517 | level = btrfs_header_level(b); |
5d4f98a2 | 2518 | if (!p->skip_locking) |
bd681513 | 2519 | btrfs_tree_read_lock(b); |
5d4f98a2 | 2520 | } else { |
bd681513 | 2521 | if (p->skip_locking) { |
5d4f98a2 | 2522 | b = btrfs_root_node(root); |
bd681513 CM |
2523 | level = btrfs_header_level(b); |
2524 | } else { | |
2525 | /* we don't know the level of the root node | |
2526 | * until we actually have it read locked | |
2527 | */ | |
2528 | b = btrfs_read_lock_root_node(root); | |
2529 | level = btrfs_header_level(b); | |
2530 | if (level <= write_lock_level) { | |
2531 | /* whoops, must trade for write lock */ | |
2532 | btrfs_tree_read_unlock(b); | |
2533 | free_extent_buffer(b); | |
2534 | b = btrfs_lock_root_node(root); | |
2535 | root_lock = BTRFS_WRITE_LOCK; | |
2536 | ||
2537 | /* the level might have changed, check again */ | |
2538 | level = btrfs_header_level(b); | |
2539 | } | |
2540 | } | |
5d4f98a2 | 2541 | } |
bd681513 CM |
2542 | p->nodes[level] = b; |
2543 | if (!p->skip_locking) | |
2544 | p->locks[level] = root_lock; | |
925baedd | 2545 | |
eb60ceac | 2546 | while (b) { |
5f39d397 | 2547 | level = btrfs_header_level(b); |
65b51a00 CM |
2548 | |
2549 | /* | |
2550 | * setup the path here so we can release it under lock | |
2551 | * contention with the cow code | |
2552 | */ | |
02217ed2 | 2553 | if (cow) { |
c8c42864 CM |
2554 | /* |
2555 | * if we don't really need to cow this block | |
2556 | * then we don't want to set the path blocking, | |
2557 | * so we test it here | |
2558 | */ | |
5d4f98a2 | 2559 | if (!should_cow_block(trans, root, b)) |
65b51a00 | 2560 | goto cow_done; |
5d4f98a2 | 2561 | |
b4ce94de CM |
2562 | btrfs_set_path_blocking(p); |
2563 | ||
bd681513 CM |
2564 | /* |
2565 | * must have write locks on this node and the | |
2566 | * parent | |
2567 | */ | |
5124e00e JB |
2568 | if (level > write_lock_level || |
2569 | (level + 1 > write_lock_level && | |
2570 | level + 1 < BTRFS_MAX_LEVEL && | |
2571 | p->nodes[level + 1])) { | |
bd681513 CM |
2572 | write_lock_level = level + 1; |
2573 | btrfs_release_path(p); | |
2574 | goto again; | |
2575 | } | |
2576 | ||
33c66f43 YZ |
2577 | err = btrfs_cow_block(trans, root, b, |
2578 | p->nodes[level + 1], | |
2579 | p->slots[level + 1], &b); | |
2580 | if (err) { | |
33c66f43 | 2581 | ret = err; |
65b51a00 | 2582 | goto done; |
54aa1f4d | 2583 | } |
02217ed2 | 2584 | } |
65b51a00 | 2585 | cow_done: |
02217ed2 | 2586 | BUG_ON(!cow && ins_len); |
65b51a00 | 2587 | |
eb60ceac | 2588 | p->nodes[level] = b; |
bd681513 | 2589 | btrfs_clear_path_blocking(p, NULL, 0); |
b4ce94de CM |
2590 | |
2591 | /* | |
2592 | * we have a lock on b and as long as we aren't changing | |
2593 | * the tree, there is no way to for the items in b to change. | |
2594 | * It is safe to drop the lock on our parent before we | |
2595 | * go through the expensive btree search on b. | |
2596 | * | |
2597 | * If cow is true, then we might be changing slot zero, | |
2598 | * which may require changing the parent. So, we can't | |
2599 | * drop the lock until after we know which slot we're | |
2600 | * operating on. | |
2601 | */ | |
2602 | if (!cow) | |
2603 | btrfs_unlock_up_safe(p, level + 1); | |
2604 | ||
5f39d397 | 2605 | ret = bin_search(b, key, level, &slot); |
b4ce94de | 2606 | |
5f39d397 | 2607 | if (level != 0) { |
33c66f43 YZ |
2608 | int dec = 0; |
2609 | if (ret && slot > 0) { | |
2610 | dec = 1; | |
be0e5c09 | 2611 | slot -= 1; |
33c66f43 | 2612 | } |
be0e5c09 | 2613 | p->slots[level] = slot; |
33c66f43 | 2614 | err = setup_nodes_for_search(trans, root, p, b, level, |
bd681513 | 2615 | ins_len, &write_lock_level); |
33c66f43 | 2616 | if (err == -EAGAIN) |
c8c42864 | 2617 | goto again; |
33c66f43 YZ |
2618 | if (err) { |
2619 | ret = err; | |
c8c42864 | 2620 | goto done; |
33c66f43 | 2621 | } |
c8c42864 CM |
2622 | b = p->nodes[level]; |
2623 | slot = p->slots[level]; | |
b4ce94de | 2624 | |
bd681513 CM |
2625 | /* |
2626 | * slot 0 is special, if we change the key | |
2627 | * we have to update the parent pointer | |
2628 | * which means we must have a write lock | |
2629 | * on the parent | |
2630 | */ | |
2631 | if (slot == 0 && cow && | |
2632 | write_lock_level < level + 1) { | |
2633 | write_lock_level = level + 1; | |
2634 | btrfs_release_path(p); | |
2635 | goto again; | |
2636 | } | |
2637 | ||
f7c79f30 CM |
2638 | unlock_up(p, level, lowest_unlock, |
2639 | min_write_lock_level, &write_lock_level); | |
f9efa9c7 | 2640 | |
925baedd | 2641 | if (level == lowest_level) { |
33c66f43 YZ |
2642 | if (dec) |
2643 | p->slots[level]++; | |
5b21f2ed | 2644 | goto done; |
925baedd | 2645 | } |
ca7a79ad | 2646 | |
33c66f43 | 2647 | err = read_block_for_search(trans, root, p, |
5d9e75c4 | 2648 | &b, level, slot, key, 0); |
33c66f43 | 2649 | if (err == -EAGAIN) |
c8c42864 | 2650 | goto again; |
33c66f43 YZ |
2651 | if (err) { |
2652 | ret = err; | |
76a05b35 | 2653 | goto done; |
33c66f43 | 2654 | } |
76a05b35 | 2655 | |
b4ce94de | 2656 | if (!p->skip_locking) { |
bd681513 CM |
2657 | level = btrfs_header_level(b); |
2658 | if (level <= write_lock_level) { | |
2659 | err = btrfs_try_tree_write_lock(b); | |
2660 | if (!err) { | |
2661 | btrfs_set_path_blocking(p); | |
2662 | btrfs_tree_lock(b); | |
2663 | btrfs_clear_path_blocking(p, b, | |
2664 | BTRFS_WRITE_LOCK); | |
2665 | } | |
2666 | p->locks[level] = BTRFS_WRITE_LOCK; | |
2667 | } else { | |
2668 | err = btrfs_try_tree_read_lock(b); | |
2669 | if (!err) { | |
2670 | btrfs_set_path_blocking(p); | |
2671 | btrfs_tree_read_lock(b); | |
2672 | btrfs_clear_path_blocking(p, b, | |
2673 | BTRFS_READ_LOCK); | |
2674 | } | |
2675 | p->locks[level] = BTRFS_READ_LOCK; | |
b4ce94de | 2676 | } |
bd681513 | 2677 | p->nodes[level] = b; |
b4ce94de | 2678 | } |
be0e5c09 CM |
2679 | } else { |
2680 | p->slots[level] = slot; | |
87b29b20 YZ |
2681 | if (ins_len > 0 && |
2682 | btrfs_leaf_free_space(root, b) < ins_len) { | |
bd681513 CM |
2683 | if (write_lock_level < 1) { |
2684 | write_lock_level = 1; | |
2685 | btrfs_release_path(p); | |
2686 | goto again; | |
2687 | } | |
2688 | ||
b4ce94de | 2689 | btrfs_set_path_blocking(p); |
33c66f43 YZ |
2690 | err = split_leaf(trans, root, key, |
2691 | p, ins_len, ret == 0); | |
bd681513 | 2692 | btrfs_clear_path_blocking(p, NULL, 0); |
b4ce94de | 2693 | |
33c66f43 YZ |
2694 | BUG_ON(err > 0); |
2695 | if (err) { | |
2696 | ret = err; | |
65b51a00 CM |
2697 | goto done; |
2698 | } | |
5c680ed6 | 2699 | } |
459931ec | 2700 | if (!p->search_for_split) |
f7c79f30 CM |
2701 | unlock_up(p, level, lowest_unlock, |
2702 | min_write_lock_level, &write_lock_level); | |
65b51a00 | 2703 | goto done; |
be0e5c09 CM |
2704 | } |
2705 | } | |
65b51a00 CM |
2706 | ret = 1; |
2707 | done: | |
b4ce94de CM |
2708 | /* |
2709 | * we don't really know what they plan on doing with the path | |
2710 | * from here on, so for now just mark it as blocking | |
2711 | */ | |
b9473439 CM |
2712 | if (!p->leave_spinning) |
2713 | btrfs_set_path_blocking(p); | |
76a05b35 | 2714 | if (ret < 0) |
b3b4aa74 | 2715 | btrfs_release_path(p); |
65b51a00 | 2716 | return ret; |
be0e5c09 CM |
2717 | } |
2718 | ||
5d9e75c4 JS |
2719 | /* |
2720 | * Like btrfs_search_slot, this looks for a key in the given tree. It uses the | |
2721 | * current state of the tree together with the operations recorded in the tree | |
2722 | * modification log to search for the key in a previous version of this tree, as | |
2723 | * denoted by the time_seq parameter. | |
2724 | * | |
2725 | * Naturally, there is no support for insert, delete or cow operations. | |
2726 | * | |
2727 | * The resulting path and return value will be set up as if we called | |
2728 | * btrfs_search_slot at that point in time with ins_len and cow both set to 0. | |
2729 | */ | |
2730 | int btrfs_search_old_slot(struct btrfs_root *root, struct btrfs_key *key, | |
2731 | struct btrfs_path *p, u64 time_seq) | |
2732 | { | |
2733 | struct extent_buffer *b; | |
2734 | int slot; | |
2735 | int ret; | |
2736 | int err; | |
2737 | int level; | |
2738 | int lowest_unlock = 1; | |
2739 | u8 lowest_level = 0; | |
2740 | ||
2741 | lowest_level = p->lowest_level; | |
2742 | WARN_ON(p->nodes[0] != NULL); | |
2743 | ||
2744 | if (p->search_commit_root) { | |
2745 | BUG_ON(time_seq); | |
2746 | return btrfs_search_slot(NULL, root, key, p, 0, 0); | |
2747 | } | |
2748 | ||
2749 | again: | |
5d9e75c4 | 2750 | b = get_old_root(root, time_seq); |
5d9e75c4 | 2751 | level = btrfs_header_level(b); |
5d9e75c4 JS |
2752 | p->locks[level] = BTRFS_READ_LOCK; |
2753 | ||
2754 | while (b) { | |
2755 | level = btrfs_header_level(b); | |
2756 | p->nodes[level] = b; | |
2757 | btrfs_clear_path_blocking(p, NULL, 0); | |
2758 | ||
2759 | /* | |
2760 | * we have a lock on b and as long as we aren't changing | |
2761 | * the tree, there is no way to for the items in b to change. | |
2762 | * It is safe to drop the lock on our parent before we | |
2763 | * go through the expensive btree search on b. | |
2764 | */ | |
2765 | btrfs_unlock_up_safe(p, level + 1); | |
2766 | ||
2767 | ret = bin_search(b, key, level, &slot); | |
2768 | ||
2769 | if (level != 0) { | |
2770 | int dec = 0; | |
2771 | if (ret && slot > 0) { | |
2772 | dec = 1; | |
2773 | slot -= 1; | |
2774 | } | |
2775 | p->slots[level] = slot; | |
2776 | unlock_up(p, level, lowest_unlock, 0, NULL); | |
2777 | ||
2778 | if (level == lowest_level) { | |
2779 | if (dec) | |
2780 | p->slots[level]++; | |
2781 | goto done; | |
2782 | } | |
2783 | ||
2784 | err = read_block_for_search(NULL, root, p, &b, level, | |
2785 | slot, key, time_seq); | |
2786 | if (err == -EAGAIN) | |
2787 | goto again; | |
2788 | if (err) { | |
2789 | ret = err; | |
2790 | goto done; | |
2791 | } | |
2792 | ||
2793 | level = btrfs_header_level(b); | |
2794 | err = btrfs_try_tree_read_lock(b); | |
2795 | if (!err) { | |
2796 | btrfs_set_path_blocking(p); | |
2797 | btrfs_tree_read_lock(b); | |
2798 | btrfs_clear_path_blocking(p, b, | |
2799 | BTRFS_READ_LOCK); | |
2800 | } | |
2801 | p->locks[level] = BTRFS_READ_LOCK; | |
2802 | p->nodes[level] = b; | |
2803 | b = tree_mod_log_rewind(root->fs_info, b, time_seq); | |
2804 | if (b != p->nodes[level]) { | |
2805 | btrfs_tree_unlock_rw(p->nodes[level], | |
2806 | p->locks[level]); | |
2807 | p->locks[level] = 0; | |
2808 | p->nodes[level] = b; | |
2809 | } | |
2810 | } else { | |
2811 | p->slots[level] = slot; | |
2812 | unlock_up(p, level, lowest_unlock, 0, NULL); | |
2813 | goto done; | |
2814 | } | |
2815 | } | |
2816 | ret = 1; | |
2817 | done: | |
2818 | if (!p->leave_spinning) | |
2819 | btrfs_set_path_blocking(p); | |
2820 | if (ret < 0) | |
2821 | btrfs_release_path(p); | |
2822 | ||
2823 | return ret; | |
2824 | } | |
2825 | ||
2f38b3e1 AJ |
2826 | /* |
2827 | * helper to use instead of search slot if no exact match is needed but | |
2828 | * instead the next or previous item should be returned. | |
2829 | * When find_higher is true, the next higher item is returned, the next lower | |
2830 | * otherwise. | |
2831 | * When return_any and find_higher are both true, and no higher item is found, | |
2832 | * return the next lower instead. | |
2833 | * When return_any is true and find_higher is false, and no lower item is found, | |
2834 | * return the next higher instead. | |
2835 | * It returns 0 if any item is found, 1 if none is found (tree empty), and | |
2836 | * < 0 on error | |
2837 | */ | |
2838 | int btrfs_search_slot_for_read(struct btrfs_root *root, | |
2839 | struct btrfs_key *key, struct btrfs_path *p, | |
2840 | int find_higher, int return_any) | |
2841 | { | |
2842 | int ret; | |
2843 | struct extent_buffer *leaf; | |
2844 | ||
2845 | again: | |
2846 | ret = btrfs_search_slot(NULL, root, key, p, 0, 0); | |
2847 | if (ret <= 0) | |
2848 | return ret; | |
2849 | /* | |
2850 | * a return value of 1 means the path is at the position where the | |
2851 | * item should be inserted. Normally this is the next bigger item, | |
2852 | * but in case the previous item is the last in a leaf, path points | |
2853 | * to the first free slot in the previous leaf, i.e. at an invalid | |
2854 | * item. | |
2855 | */ | |
2856 | leaf = p->nodes[0]; | |
2857 | ||
2858 | if (find_higher) { | |
2859 | if (p->slots[0] >= btrfs_header_nritems(leaf)) { | |
2860 | ret = btrfs_next_leaf(root, p); | |
2861 | if (ret <= 0) | |
2862 | return ret; | |
2863 | if (!return_any) | |
2864 | return 1; | |
2865 | /* | |
2866 | * no higher item found, return the next | |
2867 | * lower instead | |
2868 | */ | |
2869 | return_any = 0; | |
2870 | find_higher = 0; | |
2871 | btrfs_release_path(p); | |
2872 | goto again; | |
2873 | } | |
2874 | } else { | |
e6793769 AJ |
2875 | if (p->slots[0] == 0) { |
2876 | ret = btrfs_prev_leaf(root, p); | |
2877 | if (ret < 0) | |
2878 | return ret; | |
2879 | if (!ret) { | |
2880 | p->slots[0] = btrfs_header_nritems(leaf) - 1; | |
2881 | return 0; | |
2f38b3e1 | 2882 | } |
e6793769 AJ |
2883 | if (!return_any) |
2884 | return 1; | |
2885 | /* | |
2886 | * no lower item found, return the next | |
2887 | * higher instead | |
2888 | */ | |
2889 | return_any = 0; | |
2890 | find_higher = 1; | |
2891 | btrfs_release_path(p); | |
2892 | goto again; | |
2893 | } else { | |
2f38b3e1 AJ |
2894 | --p->slots[0]; |
2895 | } | |
2896 | } | |
2897 | return 0; | |
2898 | } | |
2899 | ||
74123bd7 CM |
2900 | /* |
2901 | * adjust the pointers going up the tree, starting at level | |
2902 | * making sure the right key of each node is points to 'key'. | |
2903 | * This is used after shifting pointers to the left, so it stops | |
2904 | * fixing up pointers when a given leaf/node is not in slot 0 of the | |
2905 | * higher levels | |
aa5d6bed | 2906 | * |
74123bd7 | 2907 | */ |
143bede5 JM |
2908 | static void fixup_low_keys(struct btrfs_trans_handle *trans, |
2909 | struct btrfs_root *root, struct btrfs_path *path, | |
2910 | struct btrfs_disk_key *key, int level) | |
be0e5c09 CM |
2911 | { |
2912 | int i; | |
5f39d397 CM |
2913 | struct extent_buffer *t; |
2914 | ||
234b63a0 | 2915 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { |
be0e5c09 | 2916 | int tslot = path->slots[i]; |
eb60ceac | 2917 | if (!path->nodes[i]) |
be0e5c09 | 2918 | break; |
5f39d397 | 2919 | t = path->nodes[i]; |
32adf090 | 2920 | tree_mod_log_set_node_key(root->fs_info, t, tslot, 1); |
5f39d397 | 2921 | btrfs_set_node_key(t, key, tslot); |
d6025579 | 2922 | btrfs_mark_buffer_dirty(path->nodes[i]); |
be0e5c09 CM |
2923 | if (tslot != 0) |
2924 | break; | |
2925 | } | |
2926 | } | |
2927 | ||
31840ae1 ZY |
2928 | /* |
2929 | * update item key. | |
2930 | * | |
2931 | * This function isn't completely safe. It's the caller's responsibility | |
2932 | * that the new key won't break the order | |
2933 | */ | |
143bede5 JM |
2934 | void btrfs_set_item_key_safe(struct btrfs_trans_handle *trans, |
2935 | struct btrfs_root *root, struct btrfs_path *path, | |
2936 | struct btrfs_key *new_key) | |
31840ae1 ZY |
2937 | { |
2938 | struct btrfs_disk_key disk_key; | |
2939 | struct extent_buffer *eb; | |
2940 | int slot; | |
2941 | ||
2942 | eb = path->nodes[0]; | |
2943 | slot = path->slots[0]; | |
2944 | if (slot > 0) { | |
2945 | btrfs_item_key(eb, &disk_key, slot - 1); | |
143bede5 | 2946 | BUG_ON(comp_keys(&disk_key, new_key) >= 0); |
31840ae1 ZY |
2947 | } |
2948 | if (slot < btrfs_header_nritems(eb) - 1) { | |
2949 | btrfs_item_key(eb, &disk_key, slot + 1); | |
143bede5 | 2950 | BUG_ON(comp_keys(&disk_key, new_key) <= 0); |
31840ae1 ZY |
2951 | } |
2952 | ||
2953 | btrfs_cpu_key_to_disk(&disk_key, new_key); | |
2954 | btrfs_set_item_key(eb, &disk_key, slot); | |
2955 | btrfs_mark_buffer_dirty(eb); | |
2956 | if (slot == 0) | |
2957 | fixup_low_keys(trans, root, path, &disk_key, 1); | |
31840ae1 ZY |
2958 | } |
2959 | ||
74123bd7 CM |
2960 | /* |
2961 | * try to push data from one node into the next node left in the | |
79f95c82 | 2962 | * tree. |
aa5d6bed CM |
2963 | * |
2964 | * returns 0 if some ptrs were pushed left, < 0 if there was some horrible | |
2965 | * error, and > 0 if there was no room in the left hand block. | |
74123bd7 | 2966 | */ |
98ed5174 CM |
2967 | static int push_node_left(struct btrfs_trans_handle *trans, |
2968 | struct btrfs_root *root, struct extent_buffer *dst, | |
971a1f66 | 2969 | struct extent_buffer *src, int empty) |
be0e5c09 | 2970 | { |
be0e5c09 | 2971 | int push_items = 0; |
bb803951 CM |
2972 | int src_nritems; |
2973 | int dst_nritems; | |
aa5d6bed | 2974 | int ret = 0; |
be0e5c09 | 2975 | |
5f39d397 CM |
2976 | src_nritems = btrfs_header_nritems(src); |
2977 | dst_nritems = btrfs_header_nritems(dst); | |
123abc88 | 2978 | push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems; |
7bb86316 CM |
2979 | WARN_ON(btrfs_header_generation(src) != trans->transid); |
2980 | WARN_ON(btrfs_header_generation(dst) != trans->transid); | |
54aa1f4d | 2981 | |
bce4eae9 | 2982 | if (!empty && src_nritems <= 8) |
971a1f66 CM |
2983 | return 1; |
2984 | ||
d397712b | 2985 | if (push_items <= 0) |
be0e5c09 CM |
2986 | return 1; |
2987 | ||
bce4eae9 | 2988 | if (empty) { |
971a1f66 | 2989 | push_items = min(src_nritems, push_items); |
bce4eae9 CM |
2990 | if (push_items < src_nritems) { |
2991 | /* leave at least 8 pointers in the node if | |
2992 | * we aren't going to empty it | |
2993 | */ | |
2994 | if (src_nritems - push_items < 8) { | |
2995 | if (push_items <= 8) | |
2996 | return 1; | |
2997 | push_items -= 8; | |
2998 | } | |
2999 | } | |
3000 | } else | |
3001 | push_items = min(src_nritems - 8, push_items); | |
79f95c82 | 3002 | |
f230475e JS |
3003 | tree_mod_log_eb_copy(root->fs_info, dst, src, dst_nritems, 0, |
3004 | push_items); | |
5f39d397 CM |
3005 | copy_extent_buffer(dst, src, |
3006 | btrfs_node_key_ptr_offset(dst_nritems), | |
3007 | btrfs_node_key_ptr_offset(0), | |
d397712b | 3008 | push_items * sizeof(struct btrfs_key_ptr)); |
5f39d397 | 3009 | |
bb803951 | 3010 | if (push_items < src_nritems) { |
57911b8b JS |
3011 | /* |
3012 | * don't call tree_mod_log_eb_move here, key removal was already | |
3013 | * fully logged by tree_mod_log_eb_copy above. | |
3014 | */ | |
5f39d397 CM |
3015 | memmove_extent_buffer(src, btrfs_node_key_ptr_offset(0), |
3016 | btrfs_node_key_ptr_offset(push_items), | |
3017 | (src_nritems - push_items) * | |
3018 | sizeof(struct btrfs_key_ptr)); | |
3019 | } | |
3020 | btrfs_set_header_nritems(src, src_nritems - push_items); | |
3021 | btrfs_set_header_nritems(dst, dst_nritems + push_items); | |
3022 | btrfs_mark_buffer_dirty(src); | |
3023 | btrfs_mark_buffer_dirty(dst); | |
31840ae1 | 3024 | |
79f95c82 CM |
3025 | return ret; |
3026 | } | |
3027 | ||
3028 | /* | |
3029 | * try to push data from one node into the next node right in the | |
3030 | * tree. | |
3031 | * | |
3032 | * returns 0 if some ptrs were pushed, < 0 if there was some horrible | |
3033 | * error, and > 0 if there was no room in the right hand block. | |
3034 | * | |
3035 | * this will only push up to 1/2 the contents of the left node over | |
3036 | */ | |
5f39d397 CM |
3037 | static int balance_node_right(struct btrfs_trans_handle *trans, |
3038 | struct btrfs_root *root, | |
3039 | struct extent_buffer *dst, | |
3040 | struct extent_buffer *src) | |
79f95c82 | 3041 | { |
79f95c82 CM |
3042 | int push_items = 0; |
3043 | int max_push; | |
3044 | int src_nritems; | |
3045 | int dst_nritems; | |
3046 | int ret = 0; | |
79f95c82 | 3047 | |
7bb86316 CM |
3048 | WARN_ON(btrfs_header_generation(src) != trans->transid); |
3049 | WARN_ON(btrfs_header_generation(dst) != trans->transid); | |
3050 | ||
5f39d397 CM |
3051 | src_nritems = btrfs_header_nritems(src); |
3052 | dst_nritems = btrfs_header_nritems(dst); | |
123abc88 | 3053 | push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems; |
d397712b | 3054 | if (push_items <= 0) |
79f95c82 | 3055 | return 1; |
bce4eae9 | 3056 | |
d397712b | 3057 | if (src_nritems < 4) |
bce4eae9 | 3058 | return 1; |
79f95c82 CM |
3059 | |
3060 | max_push = src_nritems / 2 + 1; | |
3061 | /* don't try to empty the node */ | |
d397712b | 3062 | if (max_push >= src_nritems) |
79f95c82 | 3063 | return 1; |
252c38f0 | 3064 | |
79f95c82 CM |
3065 | if (max_push < push_items) |
3066 | push_items = max_push; | |
3067 | ||
f230475e | 3068 | tree_mod_log_eb_move(root->fs_info, dst, push_items, 0, dst_nritems); |
5f39d397 CM |
3069 | memmove_extent_buffer(dst, btrfs_node_key_ptr_offset(push_items), |
3070 | btrfs_node_key_ptr_offset(0), | |
3071 | (dst_nritems) * | |
3072 | sizeof(struct btrfs_key_ptr)); | |
d6025579 | 3073 | |
f230475e JS |
3074 | tree_mod_log_eb_copy(root->fs_info, dst, src, 0, |
3075 | src_nritems - push_items, push_items); | |
5f39d397 CM |
3076 | copy_extent_buffer(dst, src, |
3077 | btrfs_node_key_ptr_offset(0), | |
3078 | btrfs_node_key_ptr_offset(src_nritems - push_items), | |
d397712b | 3079 | push_items * sizeof(struct btrfs_key_ptr)); |
79f95c82 | 3080 | |
5f39d397 CM |
3081 | btrfs_set_header_nritems(src, src_nritems - push_items); |
3082 | btrfs_set_header_nritems(dst, dst_nritems + push_items); | |
79f95c82 | 3083 | |
5f39d397 CM |
3084 | btrfs_mark_buffer_dirty(src); |
3085 | btrfs_mark_buffer_dirty(dst); | |
31840ae1 | 3086 | |
aa5d6bed | 3087 | return ret; |
be0e5c09 CM |
3088 | } |
3089 | ||
97571fd0 CM |
3090 | /* |
3091 | * helper function to insert a new root level in the tree. | |
3092 | * A new node is allocated, and a single item is inserted to | |
3093 | * point to the existing root | |
aa5d6bed CM |
3094 | * |
3095 | * returns zero on success or < 0 on failure. | |
97571fd0 | 3096 | */ |
d397712b | 3097 | static noinline int insert_new_root(struct btrfs_trans_handle *trans, |
5f39d397 CM |
3098 | struct btrfs_root *root, |
3099 | struct btrfs_path *path, int level) | |
5c680ed6 | 3100 | { |
7bb86316 | 3101 | u64 lower_gen; |
5f39d397 CM |
3102 | struct extent_buffer *lower; |
3103 | struct extent_buffer *c; | |
925baedd | 3104 | struct extent_buffer *old; |
5f39d397 | 3105 | struct btrfs_disk_key lower_key; |
5c680ed6 CM |
3106 | |
3107 | BUG_ON(path->nodes[level]); | |
3108 | BUG_ON(path->nodes[level-1] != root->node); | |
3109 | ||
7bb86316 CM |
3110 | lower = path->nodes[level-1]; |
3111 | if (level == 1) | |
3112 | btrfs_item_key(lower, &lower_key, 0); | |
3113 | else | |
3114 | btrfs_node_key(lower, &lower_key, 0); | |
3115 | ||
31840ae1 | 3116 | c = btrfs_alloc_free_block(trans, root, root->nodesize, 0, |
5d4f98a2 | 3117 | root->root_key.objectid, &lower_key, |
5581a51a | 3118 | level, root->node->start, 0); |
5f39d397 CM |
3119 | if (IS_ERR(c)) |
3120 | return PTR_ERR(c); | |
925baedd | 3121 | |
f0486c68 YZ |
3122 | root_add_used(root, root->nodesize); |
3123 | ||
5d4f98a2 | 3124 | memset_extent_buffer(c, 0, 0, sizeof(struct btrfs_header)); |
5f39d397 CM |
3125 | btrfs_set_header_nritems(c, 1); |
3126 | btrfs_set_header_level(c, level); | |
db94535d | 3127 | btrfs_set_header_bytenr(c, c->start); |
5f39d397 | 3128 | btrfs_set_header_generation(c, trans->transid); |
5d4f98a2 | 3129 | btrfs_set_header_backref_rev(c, BTRFS_MIXED_BACKREF_REV); |
5f39d397 | 3130 | btrfs_set_header_owner(c, root->root_key.objectid); |
5f39d397 CM |
3131 | |
3132 | write_extent_buffer(c, root->fs_info->fsid, | |
3133 | (unsigned long)btrfs_header_fsid(c), | |
3134 | BTRFS_FSID_SIZE); | |
e17cade2 CM |
3135 | |
3136 | write_extent_buffer(c, root->fs_info->chunk_tree_uuid, | |
3137 | (unsigned long)btrfs_header_chunk_tree_uuid(c), | |
3138 | BTRFS_UUID_SIZE); | |
3139 | ||
5f39d397 | 3140 | btrfs_set_node_key(c, &lower_key, 0); |
db94535d | 3141 | btrfs_set_node_blockptr(c, 0, lower->start); |
7bb86316 | 3142 | lower_gen = btrfs_header_generation(lower); |
31840ae1 | 3143 | WARN_ON(lower_gen != trans->transid); |
7bb86316 CM |
3144 | |
3145 | btrfs_set_node_ptr_generation(c, 0, lower_gen); | |
d5719762 | 3146 | |
5f39d397 | 3147 | btrfs_mark_buffer_dirty(c); |
d5719762 | 3148 | |
925baedd | 3149 | old = root->node; |
f230475e | 3150 | tree_mod_log_set_root_pointer(root, c); |
240f62c8 | 3151 | rcu_assign_pointer(root->node, c); |
925baedd CM |
3152 | |
3153 | /* the super has an extra ref to root->node */ | |
3154 | free_extent_buffer(old); | |
3155 | ||
0b86a832 | 3156 | add_root_to_dirty_list(root); |
5f39d397 CM |
3157 | extent_buffer_get(c); |
3158 | path->nodes[level] = c; | |
bd681513 | 3159 | path->locks[level] = BTRFS_WRITE_LOCK; |
5c680ed6 CM |
3160 | path->slots[level] = 0; |
3161 | return 0; | |
3162 | } | |
3163 | ||
74123bd7 CM |
3164 | /* |
3165 | * worker function to insert a single pointer in a node. | |
3166 | * the node should have enough room for the pointer already | |
97571fd0 | 3167 | * |
74123bd7 CM |
3168 | * slot and level indicate where you want the key to go, and |
3169 | * blocknr is the block the key points to. | |
3170 | */ | |
143bede5 JM |
3171 | static void insert_ptr(struct btrfs_trans_handle *trans, |
3172 | struct btrfs_root *root, struct btrfs_path *path, | |
3173 | struct btrfs_disk_key *key, u64 bytenr, | |
c3e06965 | 3174 | int slot, int level) |
74123bd7 | 3175 | { |
5f39d397 | 3176 | struct extent_buffer *lower; |
74123bd7 | 3177 | int nritems; |
f3ea38da | 3178 | int ret; |
5c680ed6 CM |
3179 | |
3180 | BUG_ON(!path->nodes[level]); | |
f0486c68 | 3181 | btrfs_assert_tree_locked(path->nodes[level]); |
5f39d397 CM |
3182 | lower = path->nodes[level]; |
3183 | nritems = btrfs_header_nritems(lower); | |
c293498b | 3184 | BUG_ON(slot > nritems); |
143bede5 | 3185 | BUG_ON(nritems == BTRFS_NODEPTRS_PER_BLOCK(root)); |
74123bd7 | 3186 | if (slot != nritems) { |
c3e06965 | 3187 | if (level) |
f3ea38da JS |
3188 | tree_mod_log_eb_move(root->fs_info, lower, slot + 1, |
3189 | slot, nritems - slot); | |
5f39d397 CM |
3190 | memmove_extent_buffer(lower, |
3191 | btrfs_node_key_ptr_offset(slot + 1), | |
3192 | btrfs_node_key_ptr_offset(slot), | |
d6025579 | 3193 | (nritems - slot) * sizeof(struct btrfs_key_ptr)); |
74123bd7 | 3194 | } |
c3e06965 | 3195 | if (level) { |
f3ea38da JS |
3196 | ret = tree_mod_log_insert_key(root->fs_info, lower, slot, |
3197 | MOD_LOG_KEY_ADD); | |
3198 | BUG_ON(ret < 0); | |
3199 | } | |
5f39d397 | 3200 | btrfs_set_node_key(lower, key, slot); |
db94535d | 3201 | btrfs_set_node_blockptr(lower, slot, bytenr); |
74493f7a CM |
3202 | WARN_ON(trans->transid == 0); |
3203 | btrfs_set_node_ptr_generation(lower, slot, trans->transid); | |
5f39d397 CM |
3204 | btrfs_set_header_nritems(lower, nritems + 1); |
3205 | btrfs_mark_buffer_dirty(lower); | |
74123bd7 CM |
3206 | } |
3207 | ||
97571fd0 CM |
3208 | /* |
3209 | * split the node at the specified level in path in two. | |
3210 | * The path is corrected to point to the appropriate node after the split | |
3211 | * | |
3212 | * Before splitting this tries to make some room in the node by pushing | |
3213 | * left and right, if either one works, it returns right away. | |
aa5d6bed CM |
3214 | * |
3215 | * returns 0 on success and < 0 on failure | |
97571fd0 | 3216 | */ |
e02119d5 CM |
3217 | static noinline int split_node(struct btrfs_trans_handle *trans, |
3218 | struct btrfs_root *root, | |
3219 | struct btrfs_path *path, int level) | |
be0e5c09 | 3220 | { |
5f39d397 CM |
3221 | struct extent_buffer *c; |
3222 | struct extent_buffer *split; | |
3223 | struct btrfs_disk_key disk_key; | |
be0e5c09 | 3224 | int mid; |
5c680ed6 | 3225 | int ret; |
7518a238 | 3226 | u32 c_nritems; |
eb60ceac | 3227 | |
5f39d397 | 3228 | c = path->nodes[level]; |
7bb86316 | 3229 | WARN_ON(btrfs_header_generation(c) != trans->transid); |
5f39d397 | 3230 | if (c == root->node) { |
5c680ed6 | 3231 | /* trying to split the root, lets make a new one */ |
e089f05c | 3232 | ret = insert_new_root(trans, root, path, level + 1); |
5c680ed6 CM |
3233 | if (ret) |
3234 | return ret; | |
b3612421 | 3235 | } else { |
e66f709b | 3236 | ret = push_nodes_for_insert(trans, root, path, level); |
5f39d397 CM |
3237 | c = path->nodes[level]; |
3238 | if (!ret && btrfs_header_nritems(c) < | |
c448acf0 | 3239 | BTRFS_NODEPTRS_PER_BLOCK(root) - 3) |
e66f709b | 3240 | return 0; |
54aa1f4d CM |
3241 | if (ret < 0) |
3242 | return ret; | |
be0e5c09 | 3243 | } |
e66f709b | 3244 | |
5f39d397 | 3245 | c_nritems = btrfs_header_nritems(c); |
5d4f98a2 YZ |
3246 | mid = (c_nritems + 1) / 2; |
3247 | btrfs_node_key(c, &disk_key, mid); | |
7bb86316 | 3248 | |
5d4f98a2 | 3249 | split = btrfs_alloc_free_block(trans, root, root->nodesize, 0, |
31840ae1 | 3250 | root->root_key.objectid, |
5581a51a | 3251 | &disk_key, level, c->start, 0); |
5f39d397 CM |
3252 | if (IS_ERR(split)) |
3253 | return PTR_ERR(split); | |
3254 | ||
f0486c68 YZ |
3255 | root_add_used(root, root->nodesize); |
3256 | ||
5d4f98a2 | 3257 | memset_extent_buffer(split, 0, 0, sizeof(struct btrfs_header)); |
5f39d397 | 3258 | btrfs_set_header_level(split, btrfs_header_level(c)); |
db94535d | 3259 | btrfs_set_header_bytenr(split, split->start); |
5f39d397 | 3260 | btrfs_set_header_generation(split, trans->transid); |
5d4f98a2 | 3261 | btrfs_set_header_backref_rev(split, BTRFS_MIXED_BACKREF_REV); |
5f39d397 CM |
3262 | btrfs_set_header_owner(split, root->root_key.objectid); |
3263 | write_extent_buffer(split, root->fs_info->fsid, | |
3264 | (unsigned long)btrfs_header_fsid(split), | |
3265 | BTRFS_FSID_SIZE); | |
e17cade2 CM |
3266 | write_extent_buffer(split, root->fs_info->chunk_tree_uuid, |
3267 | (unsigned long)btrfs_header_chunk_tree_uuid(split), | |
3268 | BTRFS_UUID_SIZE); | |
54aa1f4d | 3269 | |
f230475e | 3270 | tree_mod_log_eb_copy(root->fs_info, split, c, 0, mid, c_nritems - mid); |
5f39d397 CM |
3271 | copy_extent_buffer(split, c, |
3272 | btrfs_node_key_ptr_offset(0), | |
3273 | btrfs_node_key_ptr_offset(mid), | |
3274 | (c_nritems - mid) * sizeof(struct btrfs_key_ptr)); | |
3275 | btrfs_set_header_nritems(split, c_nritems - mid); | |
3276 | btrfs_set_header_nritems(c, mid); | |
aa5d6bed CM |
3277 | ret = 0; |
3278 | ||
5f39d397 CM |
3279 | btrfs_mark_buffer_dirty(c); |
3280 | btrfs_mark_buffer_dirty(split); | |
3281 | ||
143bede5 | 3282 | insert_ptr(trans, root, path, &disk_key, split->start, |
c3e06965 | 3283 | path->slots[level + 1] + 1, level + 1); |
aa5d6bed | 3284 | |
5de08d7d | 3285 | if (path->slots[level] >= mid) { |
5c680ed6 | 3286 | path->slots[level] -= mid; |
925baedd | 3287 | btrfs_tree_unlock(c); |
5f39d397 CM |
3288 | free_extent_buffer(c); |
3289 | path->nodes[level] = split; | |
5c680ed6 CM |
3290 | path->slots[level + 1] += 1; |
3291 | } else { | |
925baedd | 3292 | btrfs_tree_unlock(split); |
5f39d397 | 3293 | free_extent_buffer(split); |
be0e5c09 | 3294 | } |
aa5d6bed | 3295 | return ret; |
be0e5c09 CM |
3296 | } |
3297 | ||
74123bd7 CM |
3298 | /* |
3299 | * how many bytes are required to store the items in a leaf. start | |
3300 | * and nr indicate which items in the leaf to check. This totals up the | |
3301 | * space used both by the item structs and the item data | |
3302 | */ | |
5f39d397 | 3303 | static int leaf_space_used(struct extent_buffer *l, int start, int nr) |
be0e5c09 | 3304 | { |
41be1f3b JB |
3305 | struct btrfs_item *start_item; |
3306 | struct btrfs_item *end_item; | |
3307 | struct btrfs_map_token token; | |
be0e5c09 | 3308 | int data_len; |
5f39d397 | 3309 | int nritems = btrfs_header_nritems(l); |
d4dbff95 | 3310 | int end = min(nritems, start + nr) - 1; |
be0e5c09 CM |
3311 | |
3312 | if (!nr) | |
3313 | return 0; | |
41be1f3b JB |
3314 | btrfs_init_map_token(&token); |
3315 | start_item = btrfs_item_nr(l, start); | |
3316 | end_item = btrfs_item_nr(l, end); | |
3317 | data_len = btrfs_token_item_offset(l, start_item, &token) + | |
3318 | btrfs_token_item_size(l, start_item, &token); | |
3319 | data_len = data_len - btrfs_token_item_offset(l, end_item, &token); | |
0783fcfc | 3320 | data_len += sizeof(struct btrfs_item) * nr; |
d4dbff95 | 3321 | WARN_ON(data_len < 0); |
be0e5c09 CM |
3322 | return data_len; |
3323 | } | |
3324 | ||
d4dbff95 CM |
3325 | /* |
3326 | * The space between the end of the leaf items and | |
3327 | * the start of the leaf data. IOW, how much room | |
3328 | * the leaf has left for both items and data | |
3329 | */ | |
d397712b | 3330 | noinline int btrfs_leaf_free_space(struct btrfs_root *root, |
e02119d5 | 3331 | struct extent_buffer *leaf) |
d4dbff95 | 3332 | { |
5f39d397 CM |
3333 | int nritems = btrfs_header_nritems(leaf); |
3334 | int ret; | |
3335 | ret = BTRFS_LEAF_DATA_SIZE(root) - leaf_space_used(leaf, 0, nritems); | |
3336 | if (ret < 0) { | |
d397712b CM |
3337 | printk(KERN_CRIT "leaf free space ret %d, leaf data size %lu, " |
3338 | "used %d nritems %d\n", | |
ae2f5411 | 3339 | ret, (unsigned long) BTRFS_LEAF_DATA_SIZE(root), |
5f39d397 CM |
3340 | leaf_space_used(leaf, 0, nritems), nritems); |
3341 | } | |
3342 | return ret; | |
d4dbff95 CM |
3343 | } |
3344 | ||
99d8f83c CM |
3345 | /* |
3346 | * min slot controls the lowest index we're willing to push to the | |
3347 | * right. We'll push up to and including min_slot, but no lower | |
3348 | */ | |
44871b1b CM |
3349 | static noinline int __push_leaf_right(struct btrfs_trans_handle *trans, |
3350 | struct btrfs_root *root, | |
3351 | struct btrfs_path *path, | |
3352 | int data_size, int empty, | |
3353 | struct extent_buffer *right, | |
99d8f83c CM |
3354 | int free_space, u32 left_nritems, |
3355 | u32 min_slot) | |
00ec4c51 | 3356 | { |
5f39d397 | 3357 | struct extent_buffer *left = path->nodes[0]; |
44871b1b | 3358 | struct extent_buffer *upper = path->nodes[1]; |
cfed81a0 | 3359 | struct btrfs_map_token token; |
5f39d397 | 3360 | struct btrfs_disk_key disk_key; |
00ec4c51 | 3361 | int slot; |
34a38218 | 3362 | u32 i; |
00ec4c51 CM |
3363 | int push_space = 0; |
3364 | int push_items = 0; | |
0783fcfc | 3365 | struct btrfs_item *item; |
34a38218 | 3366 | u32 nr; |
7518a238 | 3367 | u32 right_nritems; |
5f39d397 | 3368 | u32 data_end; |
db94535d | 3369 | u32 this_item_size; |
00ec4c51 | 3370 | |
cfed81a0 CM |
3371 | btrfs_init_map_token(&token); |
3372 | ||
34a38218 CM |
3373 | if (empty) |
3374 | nr = 0; | |
3375 | else | |
99d8f83c | 3376 | nr = max_t(u32, 1, min_slot); |
34a38218 | 3377 | |
31840ae1 | 3378 | if (path->slots[0] >= left_nritems) |
87b29b20 | 3379 | push_space += data_size; |
31840ae1 | 3380 | |
44871b1b | 3381 | slot = path->slots[1]; |
34a38218 CM |
3382 | i = left_nritems - 1; |
3383 | while (i >= nr) { | |
5f39d397 | 3384 | item = btrfs_item_nr(left, i); |
db94535d | 3385 | |
31840ae1 ZY |
3386 | if (!empty && push_items > 0) { |
3387 | if (path->slots[0] > i) | |
3388 | break; | |
3389 | if (path->slots[0] == i) { | |
3390 | int space = btrfs_leaf_free_space(root, left); | |
3391 | if (space + push_space * 2 > free_space) | |
3392 | break; | |
3393 | } | |
3394 | } | |
3395 | ||
00ec4c51 | 3396 | if (path->slots[0] == i) |
87b29b20 | 3397 | push_space += data_size; |
db94535d | 3398 | |
db94535d CM |
3399 | this_item_size = btrfs_item_size(left, item); |
3400 | if (this_item_size + sizeof(*item) + push_space > free_space) | |
00ec4c51 | 3401 | break; |
31840ae1 | 3402 | |
00ec4c51 | 3403 | push_items++; |
db94535d | 3404 | push_space += this_item_size + sizeof(*item); |
34a38218 CM |
3405 | if (i == 0) |
3406 | break; | |
3407 | i--; | |
db94535d | 3408 | } |
5f39d397 | 3409 | |
925baedd CM |
3410 | if (push_items == 0) |
3411 | goto out_unlock; | |
5f39d397 | 3412 | |
6c1500f2 | 3413 | WARN_ON(!empty && push_items == left_nritems); |
5f39d397 | 3414 | |
00ec4c51 | 3415 | /* push left to right */ |
5f39d397 | 3416 | right_nritems = btrfs_header_nritems(right); |
34a38218 | 3417 | |
5f39d397 | 3418 | push_space = btrfs_item_end_nr(left, left_nritems - push_items); |
123abc88 | 3419 | push_space -= leaf_data_end(root, left); |
5f39d397 | 3420 | |
00ec4c51 | 3421 | /* make room in the right data area */ |
5f39d397 CM |
3422 | data_end = leaf_data_end(root, right); |
3423 | memmove_extent_buffer(right, | |
3424 | btrfs_leaf_data(right) + data_end - push_space, | |
3425 | btrfs_leaf_data(right) + data_end, | |
3426 | BTRFS_LEAF_DATA_SIZE(root) - data_end); | |
3427 | ||
00ec4c51 | 3428 | /* copy from the left data area */ |
5f39d397 | 3429 | copy_extent_buffer(right, left, btrfs_leaf_data(right) + |
d6025579 CM |
3430 | BTRFS_LEAF_DATA_SIZE(root) - push_space, |
3431 | btrfs_leaf_data(left) + leaf_data_end(root, left), | |
3432 | push_space); | |
5f39d397 CM |
3433 | |
3434 | memmove_extent_buffer(right, btrfs_item_nr_offset(push_items), | |
3435 | btrfs_item_nr_offset(0), | |
3436 | right_nritems * sizeof(struct btrfs_item)); | |
3437 | ||
00ec4c51 | 3438 | /* copy the items from left to right */ |
5f39d397 CM |
3439 | copy_extent_buffer(right, left, btrfs_item_nr_offset(0), |
3440 | btrfs_item_nr_offset(left_nritems - push_items), | |
3441 | push_items * sizeof(struct btrfs_item)); | |
00ec4c51 CM |
3442 | |
3443 | /* update the item pointers */ | |
7518a238 | 3444 | right_nritems += push_items; |
5f39d397 | 3445 | btrfs_set_header_nritems(right, right_nritems); |
123abc88 | 3446 | push_space = BTRFS_LEAF_DATA_SIZE(root); |
7518a238 | 3447 | for (i = 0; i < right_nritems; i++) { |
5f39d397 | 3448 | item = btrfs_item_nr(right, i); |
cfed81a0 CM |
3449 | push_space -= btrfs_token_item_size(right, item, &token); |
3450 | btrfs_set_token_item_offset(right, item, push_space, &token); | |
db94535d CM |
3451 | } |
3452 | ||
7518a238 | 3453 | left_nritems -= push_items; |
5f39d397 | 3454 | btrfs_set_header_nritems(left, left_nritems); |
00ec4c51 | 3455 | |
34a38218 CM |
3456 | if (left_nritems) |
3457 | btrfs_mark_buffer_dirty(left); | |
f0486c68 YZ |
3458 | else |
3459 | clean_tree_block(trans, root, left); | |
3460 | ||
5f39d397 | 3461 | btrfs_mark_buffer_dirty(right); |
a429e513 | 3462 | |
5f39d397 CM |
3463 | btrfs_item_key(right, &disk_key, 0); |
3464 | btrfs_set_node_key(upper, &disk_key, slot + 1); | |
d6025579 | 3465 | btrfs_mark_buffer_dirty(upper); |
02217ed2 | 3466 | |
00ec4c51 | 3467 | /* then fixup the leaf pointer in the path */ |
7518a238 CM |
3468 | if (path->slots[0] >= left_nritems) { |
3469 | path->slots[0] -= left_nritems; | |
925baedd CM |
3470 | if (btrfs_header_nritems(path->nodes[0]) == 0) |
3471 | clean_tree_block(trans, root, path->nodes[0]); | |
3472 | btrfs_tree_unlock(path->nodes[0]); | |
5f39d397 CM |
3473 | free_extent_buffer(path->nodes[0]); |
3474 | path->nodes[0] = right; | |
00ec4c51 CM |
3475 | path->slots[1] += 1; |
3476 | } else { | |
925baedd | 3477 | btrfs_tree_unlock(right); |
5f39d397 | 3478 | free_extent_buffer(right); |
00ec4c51 CM |
3479 | } |
3480 | return 0; | |
925baedd CM |
3481 | |
3482 | out_unlock: | |
3483 | btrfs_tree_unlock(right); | |
3484 | free_extent_buffer(right); | |
3485 | return 1; | |
00ec4c51 | 3486 | } |
925baedd | 3487 | |
44871b1b CM |
3488 | /* |
3489 | * push some data in the path leaf to the right, trying to free up at | |
3490 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
3491 | * | |
3492 | * returns 1 if the push failed because the other node didn't have enough | |
3493 | * room, 0 if everything worked out and < 0 if there were major errors. | |
99d8f83c CM |
3494 | * |
3495 | * this will push starting from min_slot to the end of the leaf. It won't | |
3496 | * push any slot lower than min_slot | |
44871b1b CM |
3497 | */ |
3498 | static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root | |
99d8f83c CM |
3499 | *root, struct btrfs_path *path, |
3500 | int min_data_size, int data_size, | |
3501 | int empty, u32 min_slot) | |
44871b1b CM |
3502 | { |
3503 | struct extent_buffer *left = path->nodes[0]; | |
3504 | struct extent_buffer *right; | |
3505 | struct extent_buffer *upper; | |
3506 | int slot; | |
3507 | int free_space; | |
3508 | u32 left_nritems; | |
3509 | int ret; | |
3510 | ||
3511 | if (!path->nodes[1]) | |
3512 | return 1; | |
3513 | ||
3514 | slot = path->slots[1]; | |
3515 | upper = path->nodes[1]; | |
3516 | if (slot >= btrfs_header_nritems(upper) - 1) | |
3517 | return 1; | |
3518 | ||
3519 | btrfs_assert_tree_locked(path->nodes[1]); | |
3520 | ||
3521 | right = read_node_slot(root, upper, slot + 1); | |
91ca338d TI |
3522 | if (right == NULL) |
3523 | return 1; | |
3524 | ||
44871b1b CM |
3525 | btrfs_tree_lock(right); |
3526 | btrfs_set_lock_blocking(right); | |
3527 | ||
3528 | free_space = btrfs_leaf_free_space(root, right); | |
3529 | if (free_space < data_size) | |
3530 | goto out_unlock; | |
3531 | ||
3532 | /* cow and double check */ | |
3533 | ret = btrfs_cow_block(trans, root, right, upper, | |
3534 | slot + 1, &right); | |
3535 | if (ret) | |
3536 | goto out_unlock; | |
3537 | ||
3538 | free_space = btrfs_leaf_free_space(root, right); | |
3539 | if (free_space < data_size) | |
3540 | goto out_unlock; | |
3541 | ||
3542 | left_nritems = btrfs_header_nritems(left); | |
3543 | if (left_nritems == 0) | |
3544 | goto out_unlock; | |
3545 | ||
99d8f83c CM |
3546 | return __push_leaf_right(trans, root, path, min_data_size, empty, |
3547 | right, free_space, left_nritems, min_slot); | |
44871b1b CM |
3548 | out_unlock: |
3549 | btrfs_tree_unlock(right); | |
3550 | free_extent_buffer(right); | |
3551 | return 1; | |
3552 | } | |
3553 | ||
74123bd7 CM |
3554 | /* |
3555 | * push some data in the path leaf to the left, trying to free up at | |
3556 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
99d8f83c CM |
3557 | * |
3558 | * max_slot can put a limit on how far into the leaf we'll push items. The | |
3559 | * item at 'max_slot' won't be touched. Use (u32)-1 to make us do all the | |
3560 | * items | |
74123bd7 | 3561 | */ |
44871b1b CM |
3562 | static noinline int __push_leaf_left(struct btrfs_trans_handle *trans, |
3563 | struct btrfs_root *root, | |
3564 | struct btrfs_path *path, int data_size, | |
3565 | int empty, struct extent_buffer *left, | |
99d8f83c CM |
3566 | int free_space, u32 right_nritems, |
3567 | u32 max_slot) | |
be0e5c09 | 3568 | { |
5f39d397 CM |
3569 | struct btrfs_disk_key disk_key; |
3570 | struct extent_buffer *right = path->nodes[0]; | |
be0e5c09 | 3571 | int i; |
be0e5c09 CM |
3572 | int push_space = 0; |
3573 | int push_items = 0; | |
0783fcfc | 3574 | struct btrfs_item *item; |
7518a238 | 3575 | u32 old_left_nritems; |
34a38218 | 3576 | u32 nr; |
aa5d6bed | 3577 | int ret = 0; |
db94535d CM |
3578 | u32 this_item_size; |
3579 | u32 old_left_item_size; | |
cfed81a0 CM |
3580 | struct btrfs_map_token token; |
3581 | ||
3582 | btrfs_init_map_token(&token); | |
be0e5c09 | 3583 | |
34a38218 | 3584 | if (empty) |
99d8f83c | 3585 | nr = min(right_nritems, max_slot); |
34a38218 | 3586 | else |
99d8f83c | 3587 | nr = min(right_nritems - 1, max_slot); |
34a38218 CM |
3588 | |
3589 | for (i = 0; i < nr; i++) { | |
5f39d397 | 3590 | item = btrfs_item_nr(right, i); |
db94535d | 3591 | |
31840ae1 ZY |
3592 | if (!empty && push_items > 0) { |
3593 | if (path->slots[0] < i) | |
3594 | break; | |
3595 | if (path->slots[0] == i) { | |
3596 | int space = btrfs_leaf_free_space(root, right); | |
3597 | if (space + push_space * 2 > free_space) | |
3598 | break; | |
3599 | } | |
3600 | } | |
3601 | ||
be0e5c09 | 3602 | if (path->slots[0] == i) |
87b29b20 | 3603 | push_space += data_size; |
db94535d CM |
3604 | |
3605 | this_item_size = btrfs_item_size(right, item); | |
3606 | if (this_item_size + sizeof(*item) + push_space > free_space) | |
be0e5c09 | 3607 | break; |
db94535d | 3608 | |
be0e5c09 | 3609 | push_items++; |
db94535d CM |
3610 | push_space += this_item_size + sizeof(*item); |
3611 | } | |
3612 | ||
be0e5c09 | 3613 | if (push_items == 0) { |
925baedd CM |
3614 | ret = 1; |
3615 | goto out; | |
be0e5c09 | 3616 | } |
34a38218 | 3617 | if (!empty && push_items == btrfs_header_nritems(right)) |
a429e513 | 3618 | WARN_ON(1); |
5f39d397 | 3619 | |
be0e5c09 | 3620 | /* push data from right to left */ |
5f39d397 CM |
3621 | copy_extent_buffer(left, right, |
3622 | btrfs_item_nr_offset(btrfs_header_nritems(left)), | |
3623 | btrfs_item_nr_offset(0), | |
3624 | push_items * sizeof(struct btrfs_item)); | |
3625 | ||
123abc88 | 3626 | push_space = BTRFS_LEAF_DATA_SIZE(root) - |
d397712b | 3627 | btrfs_item_offset_nr(right, push_items - 1); |
5f39d397 CM |
3628 | |
3629 | copy_extent_buffer(left, right, btrfs_leaf_data(left) + | |
d6025579 CM |
3630 | leaf_data_end(root, left) - push_space, |
3631 | btrfs_leaf_data(right) + | |
5f39d397 | 3632 | btrfs_item_offset_nr(right, push_items - 1), |
d6025579 | 3633 | push_space); |
5f39d397 | 3634 | old_left_nritems = btrfs_header_nritems(left); |
87b29b20 | 3635 | BUG_ON(old_left_nritems <= 0); |
eb60ceac | 3636 | |
db94535d | 3637 | old_left_item_size = btrfs_item_offset_nr(left, old_left_nritems - 1); |
0783fcfc | 3638 | for (i = old_left_nritems; i < old_left_nritems + push_items; i++) { |
5f39d397 | 3639 | u32 ioff; |
db94535d | 3640 | |
5f39d397 | 3641 | item = btrfs_item_nr(left, i); |
db94535d | 3642 | |
cfed81a0 CM |
3643 | ioff = btrfs_token_item_offset(left, item, &token); |
3644 | btrfs_set_token_item_offset(left, item, | |
3645 | ioff - (BTRFS_LEAF_DATA_SIZE(root) - old_left_item_size), | |
3646 | &token); | |
be0e5c09 | 3647 | } |
5f39d397 | 3648 | btrfs_set_header_nritems(left, old_left_nritems + push_items); |
be0e5c09 CM |
3649 | |
3650 | /* fixup right node */ | |
31b1a2bd JL |
3651 | if (push_items > right_nritems) |
3652 | WARN(1, KERN_CRIT "push items %d nr %u\n", push_items, | |
d397712b | 3653 | right_nritems); |
34a38218 CM |
3654 | |
3655 | if (push_items < right_nritems) { | |
3656 | push_space = btrfs_item_offset_nr(right, push_items - 1) - | |
3657 | leaf_data_end(root, right); | |
3658 | memmove_extent_buffer(right, btrfs_leaf_data(right) + | |
3659 | BTRFS_LEAF_DATA_SIZE(root) - push_space, | |
3660 | btrfs_leaf_data(right) + | |
3661 | leaf_data_end(root, right), push_space); | |
3662 | ||
3663 | memmove_extent_buffer(right, btrfs_item_nr_offset(0), | |
5f39d397 CM |
3664 | btrfs_item_nr_offset(push_items), |
3665 | (btrfs_header_nritems(right) - push_items) * | |
3666 | sizeof(struct btrfs_item)); | |
34a38218 | 3667 | } |
eef1c494 Y |
3668 | right_nritems -= push_items; |
3669 | btrfs_set_header_nritems(right, right_nritems); | |
123abc88 | 3670 | push_space = BTRFS_LEAF_DATA_SIZE(root); |
5f39d397 CM |
3671 | for (i = 0; i < right_nritems; i++) { |
3672 | item = btrfs_item_nr(right, i); | |
db94535d | 3673 | |
cfed81a0 CM |
3674 | push_space = push_space - btrfs_token_item_size(right, |
3675 | item, &token); | |
3676 | btrfs_set_token_item_offset(right, item, push_space, &token); | |
db94535d | 3677 | } |
eb60ceac | 3678 | |
5f39d397 | 3679 | btrfs_mark_buffer_dirty(left); |
34a38218 CM |
3680 | if (right_nritems) |
3681 | btrfs_mark_buffer_dirty(right); | |
f0486c68 YZ |
3682 | else |
3683 | clean_tree_block(trans, root, right); | |
098f59c2 | 3684 | |
5f39d397 | 3685 | btrfs_item_key(right, &disk_key, 0); |
143bede5 | 3686 | fixup_low_keys(trans, root, path, &disk_key, 1); |
be0e5c09 CM |
3687 | |
3688 | /* then fixup the leaf pointer in the path */ | |
3689 | if (path->slots[0] < push_items) { | |
3690 | path->slots[0] += old_left_nritems; | |
925baedd | 3691 | btrfs_tree_unlock(path->nodes[0]); |
5f39d397 CM |
3692 | free_extent_buffer(path->nodes[0]); |
3693 | path->nodes[0] = left; | |
be0e5c09 CM |
3694 | path->slots[1] -= 1; |
3695 | } else { | |
925baedd | 3696 | btrfs_tree_unlock(left); |
5f39d397 | 3697 | free_extent_buffer(left); |
be0e5c09 CM |
3698 | path->slots[0] -= push_items; |
3699 | } | |
eb60ceac | 3700 | BUG_ON(path->slots[0] < 0); |
aa5d6bed | 3701 | return ret; |
925baedd CM |
3702 | out: |
3703 | btrfs_tree_unlock(left); | |
3704 | free_extent_buffer(left); | |
3705 | return ret; | |
be0e5c09 CM |
3706 | } |
3707 | ||
44871b1b CM |
3708 | /* |
3709 | * push some data in the path leaf to the left, trying to free up at | |
3710 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
99d8f83c CM |
3711 | * |
3712 | * max_slot can put a limit on how far into the leaf we'll push items. The | |
3713 | * item at 'max_slot' won't be touched. Use (u32)-1 to make us push all the | |
3714 | * items | |
44871b1b CM |
3715 | */ |
3716 | static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root | |
99d8f83c CM |
3717 | *root, struct btrfs_path *path, int min_data_size, |
3718 | int data_size, int empty, u32 max_slot) | |
44871b1b CM |
3719 | { |
3720 | struct extent_buffer *right = path->nodes[0]; | |
3721 | struct extent_buffer *left; | |
3722 | int slot; | |
3723 | int free_space; | |
3724 | u32 right_nritems; | |
3725 | int ret = 0; | |
3726 | ||
3727 | slot = path->slots[1]; | |
3728 | if (slot == 0) | |
3729 | return 1; | |
3730 | if (!path->nodes[1]) | |
3731 | return 1; | |
3732 | ||
3733 | right_nritems = btrfs_header_nritems(right); | |
3734 | if (right_nritems == 0) | |
3735 | return 1; | |
3736 | ||
3737 | btrfs_assert_tree_locked(path->nodes[1]); | |
3738 | ||
3739 | left = read_node_slot(root, path->nodes[1], slot - 1); | |
91ca338d TI |
3740 | if (left == NULL) |
3741 | return 1; | |
3742 | ||
44871b1b CM |
3743 | btrfs_tree_lock(left); |
3744 | btrfs_set_lock_blocking(left); | |
3745 | ||
3746 | free_space = btrfs_leaf_free_space(root, left); | |
3747 | if (free_space < data_size) { | |
3748 | ret = 1; | |
3749 | goto out; | |
3750 | } | |
3751 | ||
3752 | /* cow and double check */ | |
3753 | ret = btrfs_cow_block(trans, root, left, | |
3754 | path->nodes[1], slot - 1, &left); | |
3755 | if (ret) { | |
3756 | /* we hit -ENOSPC, but it isn't fatal here */ | |
79787eaa JM |
3757 | if (ret == -ENOSPC) |
3758 | ret = 1; | |
44871b1b CM |
3759 | goto out; |
3760 | } | |
3761 | ||
3762 | free_space = btrfs_leaf_free_space(root, left); | |
3763 | if (free_space < data_size) { | |
3764 | ret = 1; | |
3765 | goto out; | |
3766 | } | |
3767 | ||
99d8f83c CM |
3768 | return __push_leaf_left(trans, root, path, min_data_size, |
3769 | empty, left, free_space, right_nritems, | |
3770 | max_slot); | |
44871b1b CM |
3771 | out: |
3772 | btrfs_tree_unlock(left); | |
3773 | free_extent_buffer(left); | |
3774 | return ret; | |
3775 | } | |
3776 | ||
3777 | /* | |
3778 | * split the path's leaf in two, making sure there is at least data_size | |
3779 | * available for the resulting leaf level of the path. | |
44871b1b | 3780 | */ |
143bede5 JM |
3781 | static noinline void copy_for_split(struct btrfs_trans_handle *trans, |
3782 | struct btrfs_root *root, | |
3783 | struct btrfs_path *path, | |
3784 | struct extent_buffer *l, | |
3785 | struct extent_buffer *right, | |
3786 | int slot, int mid, int nritems) | |
44871b1b CM |
3787 | { |
3788 | int data_copy_size; | |
3789 | int rt_data_off; | |
3790 | int i; | |
44871b1b | 3791 | struct btrfs_disk_key disk_key; |
cfed81a0 CM |
3792 | struct btrfs_map_token token; |
3793 | ||
3794 | btrfs_init_map_token(&token); | |
44871b1b CM |
3795 | |
3796 | nritems = nritems - mid; | |
3797 | btrfs_set_header_nritems(right, nritems); | |
3798 | data_copy_size = btrfs_item_end_nr(l, mid) - leaf_data_end(root, l); | |
3799 | ||
3800 | copy_extent_buffer(right, l, btrfs_item_nr_offset(0), | |
3801 | btrfs_item_nr_offset(mid), | |
3802 | nritems * sizeof(struct btrfs_item)); | |
3803 | ||
3804 | copy_extent_buffer(right, l, | |
3805 | btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) - | |
3806 | data_copy_size, btrfs_leaf_data(l) + | |
3807 | leaf_data_end(root, l), data_copy_size); | |
3808 | ||
3809 | rt_data_off = BTRFS_LEAF_DATA_SIZE(root) - | |
3810 | btrfs_item_end_nr(l, mid); | |
3811 | ||
3812 | for (i = 0; i < nritems; i++) { | |
3813 | struct btrfs_item *item = btrfs_item_nr(right, i); | |
3814 | u32 ioff; | |
3815 | ||
cfed81a0 CM |
3816 | ioff = btrfs_token_item_offset(right, item, &token); |
3817 | btrfs_set_token_item_offset(right, item, | |
3818 | ioff + rt_data_off, &token); | |
44871b1b CM |
3819 | } |
3820 | ||
44871b1b | 3821 | btrfs_set_header_nritems(l, mid); |
44871b1b | 3822 | btrfs_item_key(right, &disk_key, 0); |
143bede5 | 3823 | insert_ptr(trans, root, path, &disk_key, right->start, |
c3e06965 | 3824 | path->slots[1] + 1, 1); |
44871b1b CM |
3825 | |
3826 | btrfs_mark_buffer_dirty(right); | |
3827 | btrfs_mark_buffer_dirty(l); | |
3828 | BUG_ON(path->slots[0] != slot); | |
3829 | ||
44871b1b CM |
3830 | if (mid <= slot) { |
3831 | btrfs_tree_unlock(path->nodes[0]); | |
3832 | free_extent_buffer(path->nodes[0]); | |
3833 | path->nodes[0] = right; | |
3834 | path->slots[0] -= mid; | |
3835 | path->slots[1] += 1; | |
3836 | } else { | |
3837 | btrfs_tree_unlock(right); | |
3838 | free_extent_buffer(right); | |
3839 | } | |
3840 | ||
3841 | BUG_ON(path->slots[0] < 0); | |
44871b1b CM |
3842 | } |
3843 | ||
99d8f83c CM |
3844 | /* |
3845 | * double splits happen when we need to insert a big item in the middle | |
3846 | * of a leaf. A double split can leave us with 3 mostly empty leaves: | |
3847 | * leaf: [ slots 0 - N] [ our target ] [ N + 1 - total in leaf ] | |
3848 | * A B C | |
3849 | * | |
3850 | * We avoid this by trying to push the items on either side of our target | |
3851 | * into the adjacent leaves. If all goes well we can avoid the double split | |
3852 | * completely. | |
3853 | */ | |
3854 | static noinline int push_for_double_split(struct btrfs_trans_handle *trans, | |
3855 | struct btrfs_root *root, | |
3856 | struct btrfs_path *path, | |
3857 | int data_size) | |
3858 | { | |
3859 | int ret; | |
3860 | int progress = 0; | |
3861 | int slot; | |
3862 | u32 nritems; | |
3863 | ||
3864 | slot = path->slots[0]; | |
3865 | ||
3866 | /* | |
3867 | * try to push all the items after our slot into the | |
3868 | * right leaf | |
3869 | */ | |
3870 | ret = push_leaf_right(trans, root, path, 1, data_size, 0, slot); | |
3871 | if (ret < 0) | |
3872 | return ret; | |
3873 | ||
3874 | if (ret == 0) | |
3875 | progress++; | |
3876 | ||
3877 | nritems = btrfs_header_nritems(path->nodes[0]); | |
3878 | /* | |
3879 | * our goal is to get our slot at the start or end of a leaf. If | |
3880 | * we've done so we're done | |
3881 | */ | |
3882 | if (path->slots[0] == 0 || path->slots[0] == nritems) | |
3883 | return 0; | |
3884 | ||
3885 | if (btrfs_leaf_free_space(root, path->nodes[0]) >= data_size) | |
3886 | return 0; | |
3887 | ||
3888 | /* try to push all the items before our slot into the next leaf */ | |
3889 | slot = path->slots[0]; | |
3890 | ret = push_leaf_left(trans, root, path, 1, data_size, 0, slot); | |
3891 | if (ret < 0) | |
3892 | return ret; | |
3893 | ||
3894 | if (ret == 0) | |
3895 | progress++; | |
3896 | ||
3897 | if (progress) | |
3898 | return 0; | |
3899 | return 1; | |
3900 | } | |
3901 | ||
74123bd7 CM |
3902 | /* |
3903 | * split the path's leaf in two, making sure there is at least data_size | |
3904 | * available for the resulting leaf level of the path. | |
aa5d6bed CM |
3905 | * |
3906 | * returns 0 if all went well and < 0 on failure. | |
74123bd7 | 3907 | */ |
e02119d5 CM |
3908 | static noinline int split_leaf(struct btrfs_trans_handle *trans, |
3909 | struct btrfs_root *root, | |
3910 | struct btrfs_key *ins_key, | |
3911 | struct btrfs_path *path, int data_size, | |
3912 | int extend) | |
be0e5c09 | 3913 | { |
5d4f98a2 | 3914 | struct btrfs_disk_key disk_key; |
5f39d397 | 3915 | struct extent_buffer *l; |
7518a238 | 3916 | u32 nritems; |
eb60ceac CM |
3917 | int mid; |
3918 | int slot; | |
5f39d397 | 3919 | struct extent_buffer *right; |
d4dbff95 | 3920 | int ret = 0; |
aa5d6bed | 3921 | int wret; |
5d4f98a2 | 3922 | int split; |
cc0c5538 | 3923 | int num_doubles = 0; |
99d8f83c | 3924 | int tried_avoid_double = 0; |
aa5d6bed | 3925 | |
a5719521 YZ |
3926 | l = path->nodes[0]; |
3927 | slot = path->slots[0]; | |
3928 | if (extend && data_size + btrfs_item_size_nr(l, slot) + | |
3929 | sizeof(struct btrfs_item) > BTRFS_LEAF_DATA_SIZE(root)) | |
3930 | return -EOVERFLOW; | |
3931 | ||
40689478 | 3932 | /* first try to make some room by pushing left and right */ |
99d8f83c CM |
3933 | if (data_size) { |
3934 | wret = push_leaf_right(trans, root, path, data_size, | |
3935 | data_size, 0, 0); | |
d397712b | 3936 | if (wret < 0) |
eaee50e8 | 3937 | return wret; |
3685f791 | 3938 | if (wret) { |
99d8f83c CM |
3939 | wret = push_leaf_left(trans, root, path, data_size, |
3940 | data_size, 0, (u32)-1); | |
3685f791 CM |
3941 | if (wret < 0) |
3942 | return wret; | |
3943 | } | |
3944 | l = path->nodes[0]; | |
aa5d6bed | 3945 | |
3685f791 | 3946 | /* did the pushes work? */ |
87b29b20 | 3947 | if (btrfs_leaf_free_space(root, l) >= data_size) |
3685f791 | 3948 | return 0; |
3326d1b0 | 3949 | } |
aa5d6bed | 3950 | |
5c680ed6 | 3951 | if (!path->nodes[1]) { |
e089f05c | 3952 | ret = insert_new_root(trans, root, path, 1); |
5c680ed6 CM |
3953 | if (ret) |
3954 | return ret; | |
3955 | } | |
cc0c5538 | 3956 | again: |
5d4f98a2 | 3957 | split = 1; |
cc0c5538 | 3958 | l = path->nodes[0]; |
eb60ceac | 3959 | slot = path->slots[0]; |
5f39d397 | 3960 | nritems = btrfs_header_nritems(l); |
d397712b | 3961 | mid = (nritems + 1) / 2; |
54aa1f4d | 3962 | |
5d4f98a2 YZ |
3963 | if (mid <= slot) { |
3964 | if (nritems == 1 || | |
3965 | leaf_space_used(l, mid, nritems - mid) + data_size > | |
3966 | BTRFS_LEAF_DATA_SIZE(root)) { | |
3967 | if (slot >= nritems) { | |
3968 | split = 0; | |
3969 | } else { | |
3970 | mid = slot; | |
3971 | if (mid != nritems && | |
3972 | leaf_space_used(l, mid, nritems - mid) + | |
3973 | data_size > BTRFS_LEAF_DATA_SIZE(root)) { | |
99d8f83c CM |
3974 | if (data_size && !tried_avoid_double) |
3975 | goto push_for_double; | |
5d4f98a2 YZ |
3976 | split = 2; |
3977 | } | |
3978 | } | |
3979 | } | |
3980 | } else { | |
3981 | if (leaf_space_used(l, 0, mid) + data_size > | |
3982 | BTRFS_LEAF_DATA_SIZE(root)) { | |
3983 | if (!extend && data_size && slot == 0) { | |
3984 | split = 0; | |
3985 | } else if ((extend || !data_size) && slot == 0) { | |
3986 | mid = 1; | |
3987 | } else { | |
3988 | mid = slot; | |
3989 | if (mid != nritems && | |
3990 | leaf_space_used(l, mid, nritems - mid) + | |
3991 | data_size > BTRFS_LEAF_DATA_SIZE(root)) { | |
99d8f83c CM |
3992 | if (data_size && !tried_avoid_double) |
3993 | goto push_for_double; | |
5d4f98a2 YZ |
3994 | split = 2 ; |
3995 | } | |
3996 | } | |
3997 | } | |
3998 | } | |
3999 | ||
4000 | if (split == 0) | |
4001 | btrfs_cpu_key_to_disk(&disk_key, ins_key); | |
4002 | else | |
4003 | btrfs_item_key(l, &disk_key, mid); | |
4004 | ||
4005 | right = btrfs_alloc_free_block(trans, root, root->leafsize, 0, | |
31840ae1 | 4006 | root->root_key.objectid, |
5581a51a | 4007 | &disk_key, 0, l->start, 0); |
f0486c68 | 4008 | if (IS_ERR(right)) |
5f39d397 | 4009 | return PTR_ERR(right); |
f0486c68 YZ |
4010 | |
4011 | root_add_used(root, root->leafsize); | |
5f39d397 CM |
4012 | |
4013 | memset_extent_buffer(right, 0, 0, sizeof(struct btrfs_header)); | |
db94535d | 4014 | btrfs_set_header_bytenr(right, right->start); |
5f39d397 | 4015 | btrfs_set_header_generation(right, trans->transid); |
5d4f98a2 | 4016 | btrfs_set_header_backref_rev(right, BTRFS_MIXED_BACKREF_REV); |
5f39d397 CM |
4017 | btrfs_set_header_owner(right, root->root_key.objectid); |
4018 | btrfs_set_header_level(right, 0); | |
4019 | write_extent_buffer(right, root->fs_info->fsid, | |
4020 | (unsigned long)btrfs_header_fsid(right), | |
4021 | BTRFS_FSID_SIZE); | |
e17cade2 CM |
4022 | |
4023 | write_extent_buffer(right, root->fs_info->chunk_tree_uuid, | |
4024 | (unsigned long)btrfs_header_chunk_tree_uuid(right), | |
4025 | BTRFS_UUID_SIZE); | |
44871b1b | 4026 | |
5d4f98a2 YZ |
4027 | if (split == 0) { |
4028 | if (mid <= slot) { | |
4029 | btrfs_set_header_nritems(right, 0); | |
143bede5 | 4030 | insert_ptr(trans, root, path, &disk_key, right->start, |
c3e06965 | 4031 | path->slots[1] + 1, 1); |
5d4f98a2 YZ |
4032 | btrfs_tree_unlock(path->nodes[0]); |
4033 | free_extent_buffer(path->nodes[0]); | |
4034 | path->nodes[0] = right; | |
4035 | path->slots[0] = 0; | |
4036 | path->slots[1] += 1; | |
4037 | } else { | |
4038 | btrfs_set_header_nritems(right, 0); | |
143bede5 | 4039 | insert_ptr(trans, root, path, &disk_key, right->start, |
c3e06965 | 4040 | path->slots[1], 1); |
5d4f98a2 YZ |
4041 | btrfs_tree_unlock(path->nodes[0]); |
4042 | free_extent_buffer(path->nodes[0]); | |
4043 | path->nodes[0] = right; | |
4044 | path->slots[0] = 0; | |
143bede5 JM |
4045 | if (path->slots[1] == 0) |
4046 | fixup_low_keys(trans, root, path, | |
4047 | &disk_key, 1); | |
d4dbff95 | 4048 | } |
5d4f98a2 YZ |
4049 | btrfs_mark_buffer_dirty(right); |
4050 | return ret; | |
d4dbff95 | 4051 | } |
74123bd7 | 4052 | |
143bede5 | 4053 | copy_for_split(trans, root, path, l, right, slot, mid, nritems); |
31840ae1 | 4054 | |
5d4f98a2 | 4055 | if (split == 2) { |
cc0c5538 CM |
4056 | BUG_ON(num_doubles != 0); |
4057 | num_doubles++; | |
4058 | goto again; | |
a429e513 | 4059 | } |
44871b1b | 4060 | |
143bede5 | 4061 | return 0; |
99d8f83c CM |
4062 | |
4063 | push_for_double: | |
4064 | push_for_double_split(trans, root, path, data_size); | |
4065 | tried_avoid_double = 1; | |
4066 | if (btrfs_leaf_free_space(root, path->nodes[0]) >= data_size) | |
4067 | return 0; | |
4068 | goto again; | |
be0e5c09 CM |
4069 | } |
4070 | ||
ad48fd75 YZ |
4071 | static noinline int setup_leaf_for_split(struct btrfs_trans_handle *trans, |
4072 | struct btrfs_root *root, | |
4073 | struct btrfs_path *path, int ins_len) | |
459931ec | 4074 | { |
ad48fd75 | 4075 | struct btrfs_key key; |
459931ec | 4076 | struct extent_buffer *leaf; |
ad48fd75 YZ |
4077 | struct btrfs_file_extent_item *fi; |
4078 | u64 extent_len = 0; | |
4079 | u32 item_size; | |
4080 | int ret; | |
459931ec CM |
4081 | |
4082 | leaf = path->nodes[0]; | |
ad48fd75 YZ |
4083 | btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
4084 | ||
4085 | BUG_ON(key.type != BTRFS_EXTENT_DATA_KEY && | |
4086 | key.type != BTRFS_EXTENT_CSUM_KEY); | |
4087 | ||
4088 | if (btrfs_leaf_free_space(root, leaf) >= ins_len) | |
4089 | return 0; | |
459931ec CM |
4090 | |
4091 | item_size = btrfs_item_size_nr(leaf, path->slots[0]); | |
ad48fd75 YZ |
4092 | if (key.type == BTRFS_EXTENT_DATA_KEY) { |
4093 | fi = btrfs_item_ptr(leaf, path->slots[0], | |
4094 | struct btrfs_file_extent_item); | |
4095 | extent_len = btrfs_file_extent_num_bytes(leaf, fi); | |
4096 | } | |
b3b4aa74 | 4097 | btrfs_release_path(path); |
459931ec | 4098 | |
459931ec | 4099 | path->keep_locks = 1; |
ad48fd75 YZ |
4100 | path->search_for_split = 1; |
4101 | ret = btrfs_search_slot(trans, root, &key, path, 0, 1); | |
459931ec | 4102 | path->search_for_split = 0; |
ad48fd75 YZ |
4103 | if (ret < 0) |
4104 | goto err; | |
459931ec | 4105 | |
ad48fd75 YZ |
4106 | ret = -EAGAIN; |
4107 | leaf = path->nodes[0]; | |
459931ec | 4108 | /* if our item isn't there or got smaller, return now */ |
ad48fd75 YZ |
4109 | if (ret > 0 || item_size != btrfs_item_size_nr(leaf, path->slots[0])) |
4110 | goto err; | |
4111 | ||
109f6aef CM |
4112 | /* the leaf has changed, it now has room. return now */ |
4113 | if (btrfs_leaf_free_space(root, path->nodes[0]) >= ins_len) | |
4114 | goto err; | |
4115 | ||
ad48fd75 YZ |
4116 | if (key.type == BTRFS_EXTENT_DATA_KEY) { |
4117 | fi = btrfs_item_ptr(leaf, path->slots[0], | |
4118 | struct btrfs_file_extent_item); | |
4119 | if (extent_len != btrfs_file_extent_num_bytes(leaf, fi)) | |
4120 | goto err; | |
459931ec CM |
4121 | } |
4122 | ||
b9473439 | 4123 | btrfs_set_path_blocking(path); |
ad48fd75 | 4124 | ret = split_leaf(trans, root, &key, path, ins_len, 1); |
f0486c68 YZ |
4125 | if (ret) |
4126 | goto err; | |
459931ec | 4127 | |
ad48fd75 | 4128 | path->keep_locks = 0; |
b9473439 | 4129 | btrfs_unlock_up_safe(path, 1); |
ad48fd75 YZ |
4130 | return 0; |
4131 | err: | |
4132 | path->keep_locks = 0; | |
4133 | return ret; | |
4134 | } | |
4135 | ||
4136 | static noinline int split_item(struct btrfs_trans_handle *trans, | |
4137 | struct btrfs_root *root, | |
4138 | struct btrfs_path *path, | |
4139 | struct btrfs_key *new_key, | |
4140 | unsigned long split_offset) | |
4141 | { | |
4142 | struct extent_buffer *leaf; | |
4143 | struct btrfs_item *item; | |
4144 | struct btrfs_item *new_item; | |
4145 | int slot; | |
4146 | char *buf; | |
4147 | u32 nritems; | |
4148 | u32 item_size; | |
4149 | u32 orig_offset; | |
4150 | struct btrfs_disk_key disk_key; | |
4151 | ||
b9473439 CM |
4152 | leaf = path->nodes[0]; |
4153 | BUG_ON(btrfs_leaf_free_space(root, leaf) < sizeof(struct btrfs_item)); | |
4154 | ||
b4ce94de CM |
4155 | btrfs_set_path_blocking(path); |
4156 | ||
459931ec CM |
4157 | item = btrfs_item_nr(leaf, path->slots[0]); |
4158 | orig_offset = btrfs_item_offset(leaf, item); | |
4159 | item_size = btrfs_item_size(leaf, item); | |
4160 | ||
459931ec | 4161 | buf = kmalloc(item_size, GFP_NOFS); |
ad48fd75 YZ |
4162 | if (!buf) |
4163 | return -ENOMEM; | |
4164 | ||
459931ec CM |
4165 | read_extent_buffer(leaf, buf, btrfs_item_ptr_offset(leaf, |
4166 | path->slots[0]), item_size); | |
459931ec | 4167 | |
ad48fd75 | 4168 | slot = path->slots[0] + 1; |
459931ec | 4169 | nritems = btrfs_header_nritems(leaf); |
459931ec CM |
4170 | if (slot != nritems) { |
4171 | /* shift the items */ | |
4172 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + 1), | |
ad48fd75 YZ |
4173 | btrfs_item_nr_offset(slot), |
4174 | (nritems - slot) * sizeof(struct btrfs_item)); | |
459931ec CM |
4175 | } |
4176 | ||
4177 | btrfs_cpu_key_to_disk(&disk_key, new_key); | |
4178 | btrfs_set_item_key(leaf, &disk_key, slot); | |
4179 | ||
4180 | new_item = btrfs_item_nr(leaf, slot); | |
4181 | ||
4182 | btrfs_set_item_offset(leaf, new_item, orig_offset); | |
4183 | btrfs_set_item_size(leaf, new_item, item_size - split_offset); | |
4184 | ||
4185 | btrfs_set_item_offset(leaf, item, | |
4186 | orig_offset + item_size - split_offset); | |
4187 | btrfs_set_item_size(leaf, item, split_offset); | |
4188 | ||
4189 | btrfs_set_header_nritems(leaf, nritems + 1); | |
4190 | ||
4191 | /* write the data for the start of the original item */ | |
4192 | write_extent_buffer(leaf, buf, | |
4193 | btrfs_item_ptr_offset(leaf, path->slots[0]), | |
4194 | split_offset); | |
4195 | ||
4196 | /* write the data for the new item */ | |
4197 | write_extent_buffer(leaf, buf + split_offset, | |
4198 | btrfs_item_ptr_offset(leaf, slot), | |
4199 | item_size - split_offset); | |
4200 | btrfs_mark_buffer_dirty(leaf); | |
4201 | ||
ad48fd75 | 4202 | BUG_ON(btrfs_leaf_free_space(root, leaf) < 0); |
459931ec | 4203 | kfree(buf); |
ad48fd75 YZ |
4204 | return 0; |
4205 | } | |
4206 | ||
4207 | /* | |
4208 | * This function splits a single item into two items, | |
4209 | * giving 'new_key' to the new item and splitting the | |
4210 | * old one at split_offset (from the start of the item). | |
4211 | * | |
4212 | * The path may be released by this operation. After | |
4213 | * the split, the path is pointing to the old item. The | |
4214 | * new item is going to be in the same node as the old one. | |
4215 | * | |
4216 | * Note, the item being split must be smaller enough to live alone on | |
4217 | * a tree block with room for one extra struct btrfs_item | |
4218 | * | |
4219 | * This allows us to split the item in place, keeping a lock on the | |
4220 | * leaf the entire time. | |
4221 | */ | |
4222 | int btrfs_split_item(struct btrfs_trans_handle *trans, | |
4223 | struct btrfs_root *root, | |
4224 | struct btrfs_path *path, | |
4225 | struct btrfs_key *new_key, | |
4226 | unsigned long split_offset) | |
4227 | { | |
4228 | int ret; | |
4229 | ret = setup_leaf_for_split(trans, root, path, | |
4230 | sizeof(struct btrfs_item)); | |
4231 | if (ret) | |
4232 | return ret; | |
4233 | ||
4234 | ret = split_item(trans, root, path, new_key, split_offset); | |
459931ec CM |
4235 | return ret; |
4236 | } | |
4237 | ||
ad48fd75 YZ |
4238 | /* |
4239 | * This function duplicate a item, giving 'new_key' to the new item. | |
4240 | * It guarantees both items live in the same tree leaf and the new item | |
4241 | * is contiguous with the original item. | |
4242 | * | |
4243 | * This allows us to split file extent in place, keeping a lock on the | |
4244 | * leaf the entire time. | |
4245 | */ | |
4246 | int btrfs_duplicate_item(struct btrfs_trans_handle *trans, | |
4247 | struct btrfs_root *root, | |
4248 | struct btrfs_path *path, | |
4249 | struct btrfs_key *new_key) | |
4250 | { | |
4251 | struct extent_buffer *leaf; | |
4252 | int ret; | |
4253 | u32 item_size; | |
4254 | ||
4255 | leaf = path->nodes[0]; | |
4256 | item_size = btrfs_item_size_nr(leaf, path->slots[0]); | |
4257 | ret = setup_leaf_for_split(trans, root, path, | |
4258 | item_size + sizeof(struct btrfs_item)); | |
4259 | if (ret) | |
4260 | return ret; | |
4261 | ||
4262 | path->slots[0]++; | |
143bede5 JM |
4263 | setup_items_for_insert(trans, root, path, new_key, &item_size, |
4264 | item_size, item_size + | |
4265 | sizeof(struct btrfs_item), 1); | |
ad48fd75 YZ |
4266 | leaf = path->nodes[0]; |
4267 | memcpy_extent_buffer(leaf, | |
4268 | btrfs_item_ptr_offset(leaf, path->slots[0]), | |
4269 | btrfs_item_ptr_offset(leaf, path->slots[0] - 1), | |
4270 | item_size); | |
4271 | return 0; | |
4272 | } | |
4273 | ||
d352ac68 CM |
4274 | /* |
4275 | * make the item pointed to by the path smaller. new_size indicates | |
4276 | * how small to make it, and from_end tells us if we just chop bytes | |
4277 | * off the end of the item or if we shift the item to chop bytes off | |
4278 | * the front. | |
4279 | */ | |
143bede5 JM |
4280 | void btrfs_truncate_item(struct btrfs_trans_handle *trans, |
4281 | struct btrfs_root *root, | |
4282 | struct btrfs_path *path, | |
4283 | u32 new_size, int from_end) | |
b18c6685 | 4284 | { |
b18c6685 | 4285 | int slot; |
5f39d397 CM |
4286 | struct extent_buffer *leaf; |
4287 | struct btrfs_item *item; | |
b18c6685 CM |
4288 | u32 nritems; |
4289 | unsigned int data_end; | |
4290 | unsigned int old_data_start; | |
4291 | unsigned int old_size; | |
4292 | unsigned int size_diff; | |
4293 | int i; | |
cfed81a0 CM |
4294 | struct btrfs_map_token token; |
4295 | ||
4296 | btrfs_init_map_token(&token); | |
b18c6685 | 4297 | |
5f39d397 | 4298 | leaf = path->nodes[0]; |
179e29e4 CM |
4299 | slot = path->slots[0]; |
4300 | ||
4301 | old_size = btrfs_item_size_nr(leaf, slot); | |
4302 | if (old_size == new_size) | |
143bede5 | 4303 | return; |
b18c6685 | 4304 | |
5f39d397 | 4305 | nritems = btrfs_header_nritems(leaf); |
b18c6685 CM |
4306 | data_end = leaf_data_end(root, leaf); |
4307 | ||
5f39d397 | 4308 | old_data_start = btrfs_item_offset_nr(leaf, slot); |
179e29e4 | 4309 | |
b18c6685 CM |
4310 | size_diff = old_size - new_size; |
4311 | ||
4312 | BUG_ON(slot < 0); | |
4313 | BUG_ON(slot >= nritems); | |
4314 | ||
4315 | /* | |
4316 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
4317 | */ | |
4318 | /* first correct the data pointers */ | |
4319 | for (i = slot; i < nritems; i++) { | |
5f39d397 CM |
4320 | u32 ioff; |
4321 | item = btrfs_item_nr(leaf, i); | |
db94535d | 4322 | |
cfed81a0 CM |
4323 | ioff = btrfs_token_item_offset(leaf, item, &token); |
4324 | btrfs_set_token_item_offset(leaf, item, | |
4325 | ioff + size_diff, &token); | |
b18c6685 | 4326 | } |
db94535d | 4327 | |
b18c6685 | 4328 | /* shift the data */ |
179e29e4 CM |
4329 | if (from_end) { |
4330 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + | |
4331 | data_end + size_diff, btrfs_leaf_data(leaf) + | |
4332 | data_end, old_data_start + new_size - data_end); | |
4333 | } else { | |
4334 | struct btrfs_disk_key disk_key; | |
4335 | u64 offset; | |
4336 | ||
4337 | btrfs_item_key(leaf, &disk_key, slot); | |
4338 | ||
4339 | if (btrfs_disk_key_type(&disk_key) == BTRFS_EXTENT_DATA_KEY) { | |
4340 | unsigned long ptr; | |
4341 | struct btrfs_file_extent_item *fi; | |
4342 | ||
4343 | fi = btrfs_item_ptr(leaf, slot, | |
4344 | struct btrfs_file_extent_item); | |
4345 | fi = (struct btrfs_file_extent_item *)( | |
4346 | (unsigned long)fi - size_diff); | |
4347 | ||
4348 | if (btrfs_file_extent_type(leaf, fi) == | |
4349 | BTRFS_FILE_EXTENT_INLINE) { | |
4350 | ptr = btrfs_item_ptr_offset(leaf, slot); | |
4351 | memmove_extent_buffer(leaf, ptr, | |
d397712b CM |
4352 | (unsigned long)fi, |
4353 | offsetof(struct btrfs_file_extent_item, | |
179e29e4 CM |
4354 | disk_bytenr)); |
4355 | } | |
4356 | } | |
4357 | ||
4358 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + | |
4359 | data_end + size_diff, btrfs_leaf_data(leaf) + | |
4360 | data_end, old_data_start - data_end); | |
4361 | ||
4362 | offset = btrfs_disk_key_offset(&disk_key); | |
4363 | btrfs_set_disk_key_offset(&disk_key, offset + size_diff); | |
4364 | btrfs_set_item_key(leaf, &disk_key, slot); | |
4365 | if (slot == 0) | |
4366 | fixup_low_keys(trans, root, path, &disk_key, 1); | |
4367 | } | |
5f39d397 CM |
4368 | |
4369 | item = btrfs_item_nr(leaf, slot); | |
4370 | btrfs_set_item_size(leaf, item, new_size); | |
4371 | btrfs_mark_buffer_dirty(leaf); | |
b18c6685 | 4372 | |
5f39d397 CM |
4373 | if (btrfs_leaf_free_space(root, leaf) < 0) { |
4374 | btrfs_print_leaf(root, leaf); | |
b18c6685 | 4375 | BUG(); |
5f39d397 | 4376 | } |
b18c6685 CM |
4377 | } |
4378 | ||
d352ac68 CM |
4379 | /* |
4380 | * make the item pointed to by the path bigger, data_size is the new size. | |
4381 | */ | |
143bede5 JM |
4382 | void btrfs_extend_item(struct btrfs_trans_handle *trans, |
4383 | struct btrfs_root *root, struct btrfs_path *path, | |
4384 | u32 data_size) | |
6567e837 | 4385 | { |
6567e837 | 4386 | int slot; |
5f39d397 CM |
4387 | struct extent_buffer *leaf; |
4388 | struct btrfs_item *item; | |
6567e837 CM |
4389 | u32 nritems; |
4390 | unsigned int data_end; | |
4391 | unsigned int old_data; | |
4392 | unsigned int old_size; | |
4393 | int i; | |
cfed81a0 CM |
4394 | struct btrfs_map_token token; |
4395 | ||
4396 | btrfs_init_map_token(&token); | |
6567e837 | 4397 | |
5f39d397 | 4398 | leaf = path->nodes[0]; |
6567e837 | 4399 | |
5f39d397 | 4400 | nritems = btrfs_header_nritems(leaf); |
6567e837 CM |
4401 | data_end = leaf_data_end(root, leaf); |
4402 | ||
5f39d397 CM |
4403 | if (btrfs_leaf_free_space(root, leaf) < data_size) { |
4404 | btrfs_print_leaf(root, leaf); | |
6567e837 | 4405 | BUG(); |
5f39d397 | 4406 | } |
6567e837 | 4407 | slot = path->slots[0]; |
5f39d397 | 4408 | old_data = btrfs_item_end_nr(leaf, slot); |
6567e837 CM |
4409 | |
4410 | BUG_ON(slot < 0); | |
3326d1b0 CM |
4411 | if (slot >= nritems) { |
4412 | btrfs_print_leaf(root, leaf); | |
d397712b CM |
4413 | printk(KERN_CRIT "slot %d too large, nritems %d\n", |
4414 | slot, nritems); | |
3326d1b0 CM |
4415 | BUG_ON(1); |
4416 | } | |
6567e837 CM |
4417 | |
4418 | /* | |
4419 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
4420 | */ | |
4421 | /* first correct the data pointers */ | |
4422 | for (i = slot; i < nritems; i++) { | |
5f39d397 CM |
4423 | u32 ioff; |
4424 | item = btrfs_item_nr(leaf, i); | |
db94535d | 4425 | |
cfed81a0 CM |
4426 | ioff = btrfs_token_item_offset(leaf, item, &token); |
4427 | btrfs_set_token_item_offset(leaf, item, | |
4428 | ioff - data_size, &token); | |
6567e837 | 4429 | } |
5f39d397 | 4430 | |
6567e837 | 4431 | /* shift the data */ |
5f39d397 | 4432 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + |
6567e837 CM |
4433 | data_end - data_size, btrfs_leaf_data(leaf) + |
4434 | data_end, old_data - data_end); | |
5f39d397 | 4435 | |
6567e837 | 4436 | data_end = old_data; |
5f39d397 CM |
4437 | old_size = btrfs_item_size_nr(leaf, slot); |
4438 | item = btrfs_item_nr(leaf, slot); | |
4439 | btrfs_set_item_size(leaf, item, old_size + data_size); | |
4440 | btrfs_mark_buffer_dirty(leaf); | |
6567e837 | 4441 | |
5f39d397 CM |
4442 | if (btrfs_leaf_free_space(root, leaf) < 0) { |
4443 | btrfs_print_leaf(root, leaf); | |
6567e837 | 4444 | BUG(); |
5f39d397 | 4445 | } |
6567e837 CM |
4446 | } |
4447 | ||
74123bd7 | 4448 | /* |
44871b1b CM |
4449 | * this is a helper for btrfs_insert_empty_items, the main goal here is |
4450 | * to save stack depth by doing the bulk of the work in a function | |
4451 | * that doesn't call btrfs_search_slot | |
74123bd7 | 4452 | */ |
143bede5 JM |
4453 | void setup_items_for_insert(struct btrfs_trans_handle *trans, |
4454 | struct btrfs_root *root, struct btrfs_path *path, | |
4455 | struct btrfs_key *cpu_key, u32 *data_size, | |
4456 | u32 total_data, u32 total_size, int nr) | |
be0e5c09 | 4457 | { |
5f39d397 | 4458 | struct btrfs_item *item; |
9c58309d | 4459 | int i; |
7518a238 | 4460 | u32 nritems; |
be0e5c09 | 4461 | unsigned int data_end; |
e2fa7227 | 4462 | struct btrfs_disk_key disk_key; |
44871b1b CM |
4463 | struct extent_buffer *leaf; |
4464 | int slot; | |
cfed81a0 CM |
4465 | struct btrfs_map_token token; |
4466 | ||
4467 | btrfs_init_map_token(&token); | |
e2fa7227 | 4468 | |
5f39d397 | 4469 | leaf = path->nodes[0]; |
44871b1b | 4470 | slot = path->slots[0]; |
74123bd7 | 4471 | |
5f39d397 | 4472 | nritems = btrfs_header_nritems(leaf); |
123abc88 | 4473 | data_end = leaf_data_end(root, leaf); |
eb60ceac | 4474 | |
f25956cc | 4475 | if (btrfs_leaf_free_space(root, leaf) < total_size) { |
3326d1b0 | 4476 | btrfs_print_leaf(root, leaf); |
d397712b | 4477 | printk(KERN_CRIT "not enough freespace need %u have %d\n", |
9c58309d | 4478 | total_size, btrfs_leaf_free_space(root, leaf)); |
be0e5c09 | 4479 | BUG(); |
d4dbff95 | 4480 | } |
5f39d397 | 4481 | |
be0e5c09 | 4482 | if (slot != nritems) { |
5f39d397 | 4483 | unsigned int old_data = btrfs_item_end_nr(leaf, slot); |
be0e5c09 | 4484 | |
5f39d397 CM |
4485 | if (old_data < data_end) { |
4486 | btrfs_print_leaf(root, leaf); | |
d397712b | 4487 | printk(KERN_CRIT "slot %d old_data %d data_end %d\n", |
5f39d397 CM |
4488 | slot, old_data, data_end); |
4489 | BUG_ON(1); | |
4490 | } | |
be0e5c09 CM |
4491 | /* |
4492 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
4493 | */ | |
4494 | /* first correct the data pointers */ | |
0783fcfc | 4495 | for (i = slot; i < nritems; i++) { |
5f39d397 | 4496 | u32 ioff; |
db94535d | 4497 | |
5f39d397 | 4498 | item = btrfs_item_nr(leaf, i); |
cfed81a0 CM |
4499 | ioff = btrfs_token_item_offset(leaf, item, &token); |
4500 | btrfs_set_token_item_offset(leaf, item, | |
4501 | ioff - total_data, &token); | |
0783fcfc | 4502 | } |
be0e5c09 | 4503 | /* shift the items */ |
9c58309d | 4504 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr), |
5f39d397 | 4505 | btrfs_item_nr_offset(slot), |
d6025579 | 4506 | (nritems - slot) * sizeof(struct btrfs_item)); |
be0e5c09 CM |
4507 | |
4508 | /* shift the data */ | |
5f39d397 | 4509 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + |
9c58309d | 4510 | data_end - total_data, btrfs_leaf_data(leaf) + |
d6025579 | 4511 | data_end, old_data - data_end); |
be0e5c09 CM |
4512 | data_end = old_data; |
4513 | } | |
5f39d397 | 4514 | |
62e2749e | 4515 | /* setup the item for the new data */ |
9c58309d CM |
4516 | for (i = 0; i < nr; i++) { |
4517 | btrfs_cpu_key_to_disk(&disk_key, cpu_key + i); | |
4518 | btrfs_set_item_key(leaf, &disk_key, slot + i); | |
4519 | item = btrfs_item_nr(leaf, slot + i); | |
cfed81a0 CM |
4520 | btrfs_set_token_item_offset(leaf, item, |
4521 | data_end - data_size[i], &token); | |
9c58309d | 4522 | data_end -= data_size[i]; |
cfed81a0 | 4523 | btrfs_set_token_item_size(leaf, item, data_size[i], &token); |
9c58309d | 4524 | } |
44871b1b | 4525 | |
9c58309d | 4526 | btrfs_set_header_nritems(leaf, nritems + nr); |
aa5d6bed | 4527 | |
5a01a2e3 CM |
4528 | if (slot == 0) { |
4529 | btrfs_cpu_key_to_disk(&disk_key, cpu_key); | |
143bede5 | 4530 | fixup_low_keys(trans, root, path, &disk_key, 1); |
5a01a2e3 | 4531 | } |
b9473439 CM |
4532 | btrfs_unlock_up_safe(path, 1); |
4533 | btrfs_mark_buffer_dirty(leaf); | |
aa5d6bed | 4534 | |
5f39d397 CM |
4535 | if (btrfs_leaf_free_space(root, leaf) < 0) { |
4536 | btrfs_print_leaf(root, leaf); | |
be0e5c09 | 4537 | BUG(); |
5f39d397 | 4538 | } |
44871b1b CM |
4539 | } |
4540 | ||
4541 | /* | |
4542 | * Given a key and some data, insert items into the tree. | |
4543 | * This does all the path init required, making room in the tree if needed. | |
4544 | */ | |
4545 | int btrfs_insert_empty_items(struct btrfs_trans_handle *trans, | |
4546 | struct btrfs_root *root, | |
4547 | struct btrfs_path *path, | |
4548 | struct btrfs_key *cpu_key, u32 *data_size, | |
4549 | int nr) | |
4550 | { | |
44871b1b CM |
4551 | int ret = 0; |
4552 | int slot; | |
4553 | int i; | |
4554 | u32 total_size = 0; | |
4555 | u32 total_data = 0; | |
4556 | ||
4557 | for (i = 0; i < nr; i++) | |
4558 | total_data += data_size[i]; | |
4559 | ||
4560 | total_size = total_data + (nr * sizeof(struct btrfs_item)); | |
4561 | ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1); | |
4562 | if (ret == 0) | |
4563 | return -EEXIST; | |
4564 | if (ret < 0) | |
143bede5 | 4565 | return ret; |
44871b1b | 4566 | |
44871b1b CM |
4567 | slot = path->slots[0]; |
4568 | BUG_ON(slot < 0); | |
4569 | ||
143bede5 | 4570 | setup_items_for_insert(trans, root, path, cpu_key, data_size, |
44871b1b | 4571 | total_data, total_size, nr); |
143bede5 | 4572 | return 0; |
62e2749e CM |
4573 | } |
4574 | ||
4575 | /* | |
4576 | * Given a key and some data, insert an item into the tree. | |
4577 | * This does all the path init required, making room in the tree if needed. | |
4578 | */ | |
e089f05c CM |
4579 | int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root |
4580 | *root, struct btrfs_key *cpu_key, void *data, u32 | |
4581 | data_size) | |
62e2749e CM |
4582 | { |
4583 | int ret = 0; | |
2c90e5d6 | 4584 | struct btrfs_path *path; |
5f39d397 CM |
4585 | struct extent_buffer *leaf; |
4586 | unsigned long ptr; | |
62e2749e | 4587 | |
2c90e5d6 | 4588 | path = btrfs_alloc_path(); |
db5b493a TI |
4589 | if (!path) |
4590 | return -ENOMEM; | |
2c90e5d6 | 4591 | ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size); |
62e2749e | 4592 | if (!ret) { |
5f39d397 CM |
4593 | leaf = path->nodes[0]; |
4594 | ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); | |
4595 | write_extent_buffer(leaf, data, ptr, data_size); | |
4596 | btrfs_mark_buffer_dirty(leaf); | |
62e2749e | 4597 | } |
2c90e5d6 | 4598 | btrfs_free_path(path); |
aa5d6bed | 4599 | return ret; |
be0e5c09 CM |
4600 | } |
4601 | ||
74123bd7 | 4602 | /* |
5de08d7d | 4603 | * delete the pointer from a given node. |
74123bd7 | 4604 | * |
d352ac68 CM |
4605 | * the tree should have been previously balanced so the deletion does not |
4606 | * empty a node. | |
74123bd7 | 4607 | */ |
143bede5 | 4608 | static void del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
0e411ece | 4609 | struct btrfs_path *path, int level, int slot) |
be0e5c09 | 4610 | { |
5f39d397 | 4611 | struct extent_buffer *parent = path->nodes[level]; |
7518a238 | 4612 | u32 nritems; |
f3ea38da | 4613 | int ret; |
be0e5c09 | 4614 | |
5f39d397 | 4615 | nritems = btrfs_header_nritems(parent); |
d397712b | 4616 | if (slot != nritems - 1) { |
0e411ece | 4617 | if (level) |
f3ea38da JS |
4618 | tree_mod_log_eb_move(root->fs_info, parent, slot, |
4619 | slot + 1, nritems - slot - 1); | |
5f39d397 CM |
4620 | memmove_extent_buffer(parent, |
4621 | btrfs_node_key_ptr_offset(slot), | |
4622 | btrfs_node_key_ptr_offset(slot + 1), | |
d6025579 CM |
4623 | sizeof(struct btrfs_key_ptr) * |
4624 | (nritems - slot - 1)); | |
57ba86c0 CM |
4625 | } else if (level) { |
4626 | ret = tree_mod_log_insert_key(root->fs_info, parent, slot, | |
4627 | MOD_LOG_KEY_REMOVE); | |
4628 | BUG_ON(ret < 0); | |
bb803951 | 4629 | } |
f3ea38da | 4630 | |
7518a238 | 4631 | nritems--; |
5f39d397 | 4632 | btrfs_set_header_nritems(parent, nritems); |
7518a238 | 4633 | if (nritems == 0 && parent == root->node) { |
5f39d397 | 4634 | BUG_ON(btrfs_header_level(root->node) != 1); |
bb803951 | 4635 | /* just turn the root into a leaf and break */ |
5f39d397 | 4636 | btrfs_set_header_level(root->node, 0); |
bb803951 | 4637 | } else if (slot == 0) { |
5f39d397 CM |
4638 | struct btrfs_disk_key disk_key; |
4639 | ||
4640 | btrfs_node_key(parent, &disk_key, 0); | |
143bede5 | 4641 | fixup_low_keys(trans, root, path, &disk_key, level + 1); |
be0e5c09 | 4642 | } |
d6025579 | 4643 | btrfs_mark_buffer_dirty(parent); |
be0e5c09 CM |
4644 | } |
4645 | ||
323ac95b CM |
4646 | /* |
4647 | * a helper function to delete the leaf pointed to by path->slots[1] and | |
5d4f98a2 | 4648 | * path->nodes[1]. |
323ac95b CM |
4649 | * |
4650 | * This deletes the pointer in path->nodes[1] and frees the leaf | |
4651 | * block extent. zero is returned if it all worked out, < 0 otherwise. | |
4652 | * | |
4653 | * The path must have already been setup for deleting the leaf, including | |
4654 | * all the proper balancing. path->nodes[1] must be locked. | |
4655 | */ | |
143bede5 JM |
4656 | static noinline void btrfs_del_leaf(struct btrfs_trans_handle *trans, |
4657 | struct btrfs_root *root, | |
4658 | struct btrfs_path *path, | |
4659 | struct extent_buffer *leaf) | |
323ac95b | 4660 | { |
5d4f98a2 | 4661 | WARN_ON(btrfs_header_generation(leaf) != trans->transid); |
0e411ece | 4662 | del_ptr(trans, root, path, 1, path->slots[1]); |
323ac95b | 4663 | |
4d081c41 CM |
4664 | /* |
4665 | * btrfs_free_extent is expensive, we want to make sure we | |
4666 | * aren't holding any locks when we call it | |
4667 | */ | |
4668 | btrfs_unlock_up_safe(path, 0); | |
4669 | ||
f0486c68 YZ |
4670 | root_sub_used(root, leaf->len); |
4671 | ||
3083ee2e | 4672 | extent_buffer_get(leaf); |
5581a51a | 4673 | btrfs_free_tree_block(trans, root, leaf, 0, 1); |
3083ee2e | 4674 | free_extent_buffer_stale(leaf); |
323ac95b | 4675 | } |
74123bd7 CM |
4676 | /* |
4677 | * delete the item at the leaf level in path. If that empties | |
4678 | * the leaf, remove it from the tree | |
4679 | */ | |
85e21bac CM |
4680 | int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
4681 | struct btrfs_path *path, int slot, int nr) | |
be0e5c09 | 4682 | { |
5f39d397 CM |
4683 | struct extent_buffer *leaf; |
4684 | struct btrfs_item *item; | |
85e21bac CM |
4685 | int last_off; |
4686 | int dsize = 0; | |
aa5d6bed CM |
4687 | int ret = 0; |
4688 | int wret; | |
85e21bac | 4689 | int i; |
7518a238 | 4690 | u32 nritems; |
cfed81a0 CM |
4691 | struct btrfs_map_token token; |
4692 | ||
4693 | btrfs_init_map_token(&token); | |
be0e5c09 | 4694 | |
5f39d397 | 4695 | leaf = path->nodes[0]; |
85e21bac CM |
4696 | last_off = btrfs_item_offset_nr(leaf, slot + nr - 1); |
4697 | ||
4698 | for (i = 0; i < nr; i++) | |
4699 | dsize += btrfs_item_size_nr(leaf, slot + i); | |
4700 | ||
5f39d397 | 4701 | nritems = btrfs_header_nritems(leaf); |
be0e5c09 | 4702 | |
85e21bac | 4703 | if (slot + nr != nritems) { |
123abc88 | 4704 | int data_end = leaf_data_end(root, leaf); |
5f39d397 CM |
4705 | |
4706 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + | |
d6025579 CM |
4707 | data_end + dsize, |
4708 | btrfs_leaf_data(leaf) + data_end, | |
85e21bac | 4709 | last_off - data_end); |
5f39d397 | 4710 | |
85e21bac | 4711 | for (i = slot + nr; i < nritems; i++) { |
5f39d397 | 4712 | u32 ioff; |
db94535d | 4713 | |
5f39d397 | 4714 | item = btrfs_item_nr(leaf, i); |
cfed81a0 CM |
4715 | ioff = btrfs_token_item_offset(leaf, item, &token); |
4716 | btrfs_set_token_item_offset(leaf, item, | |
4717 | ioff + dsize, &token); | |
0783fcfc | 4718 | } |
db94535d | 4719 | |
5f39d397 | 4720 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot), |
85e21bac | 4721 | btrfs_item_nr_offset(slot + nr), |
d6025579 | 4722 | sizeof(struct btrfs_item) * |
85e21bac | 4723 | (nritems - slot - nr)); |
be0e5c09 | 4724 | } |
85e21bac CM |
4725 | btrfs_set_header_nritems(leaf, nritems - nr); |
4726 | nritems -= nr; | |
5f39d397 | 4727 | |
74123bd7 | 4728 | /* delete the leaf if we've emptied it */ |
7518a238 | 4729 | if (nritems == 0) { |
5f39d397 CM |
4730 | if (leaf == root->node) { |
4731 | btrfs_set_header_level(leaf, 0); | |
9a8dd150 | 4732 | } else { |
f0486c68 YZ |
4733 | btrfs_set_path_blocking(path); |
4734 | clean_tree_block(trans, root, leaf); | |
143bede5 | 4735 | btrfs_del_leaf(trans, root, path, leaf); |
9a8dd150 | 4736 | } |
be0e5c09 | 4737 | } else { |
7518a238 | 4738 | int used = leaf_space_used(leaf, 0, nritems); |
aa5d6bed | 4739 | if (slot == 0) { |
5f39d397 CM |
4740 | struct btrfs_disk_key disk_key; |
4741 | ||
4742 | btrfs_item_key(leaf, &disk_key, 0); | |
143bede5 | 4743 | fixup_low_keys(trans, root, path, &disk_key, 1); |
aa5d6bed | 4744 | } |
aa5d6bed | 4745 | |
74123bd7 | 4746 | /* delete the leaf if it is mostly empty */ |
d717aa1d | 4747 | if (used < BTRFS_LEAF_DATA_SIZE(root) / 3) { |
be0e5c09 CM |
4748 | /* push_leaf_left fixes the path. |
4749 | * make sure the path still points to our leaf | |
4750 | * for possible call to del_ptr below | |
4751 | */ | |
4920c9ac | 4752 | slot = path->slots[1]; |
5f39d397 CM |
4753 | extent_buffer_get(leaf); |
4754 | ||
b9473439 | 4755 | btrfs_set_path_blocking(path); |
99d8f83c CM |
4756 | wret = push_leaf_left(trans, root, path, 1, 1, |
4757 | 1, (u32)-1); | |
54aa1f4d | 4758 | if (wret < 0 && wret != -ENOSPC) |
aa5d6bed | 4759 | ret = wret; |
5f39d397 CM |
4760 | |
4761 | if (path->nodes[0] == leaf && | |
4762 | btrfs_header_nritems(leaf)) { | |
99d8f83c CM |
4763 | wret = push_leaf_right(trans, root, path, 1, |
4764 | 1, 1, 0); | |
54aa1f4d | 4765 | if (wret < 0 && wret != -ENOSPC) |
aa5d6bed CM |
4766 | ret = wret; |
4767 | } | |
5f39d397 CM |
4768 | |
4769 | if (btrfs_header_nritems(leaf) == 0) { | |
323ac95b | 4770 | path->slots[1] = slot; |
143bede5 | 4771 | btrfs_del_leaf(trans, root, path, leaf); |
5f39d397 | 4772 | free_extent_buffer(leaf); |
143bede5 | 4773 | ret = 0; |
5de08d7d | 4774 | } else { |
925baedd CM |
4775 | /* if we're still in the path, make sure |
4776 | * we're dirty. Otherwise, one of the | |
4777 | * push_leaf functions must have already | |
4778 | * dirtied this buffer | |
4779 | */ | |
4780 | if (path->nodes[0] == leaf) | |
4781 | btrfs_mark_buffer_dirty(leaf); | |
5f39d397 | 4782 | free_extent_buffer(leaf); |
be0e5c09 | 4783 | } |
d5719762 | 4784 | } else { |
5f39d397 | 4785 | btrfs_mark_buffer_dirty(leaf); |
be0e5c09 CM |
4786 | } |
4787 | } | |
aa5d6bed | 4788 | return ret; |
be0e5c09 CM |
4789 | } |
4790 | ||
7bb86316 | 4791 | /* |
925baedd | 4792 | * search the tree again to find a leaf with lesser keys |
7bb86316 CM |
4793 | * returns 0 if it found something or 1 if there are no lesser leaves. |
4794 | * returns < 0 on io errors. | |
d352ac68 CM |
4795 | * |
4796 | * This may release the path, and so you may lose any locks held at the | |
4797 | * time you call it. | |
7bb86316 CM |
4798 | */ |
4799 | int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path) | |
4800 | { | |
925baedd CM |
4801 | struct btrfs_key key; |
4802 | struct btrfs_disk_key found_key; | |
4803 | int ret; | |
7bb86316 | 4804 | |
925baedd | 4805 | btrfs_item_key_to_cpu(path->nodes[0], &key, 0); |
7bb86316 | 4806 | |
925baedd CM |
4807 | if (key.offset > 0) |
4808 | key.offset--; | |
4809 | else if (key.type > 0) | |
4810 | key.type--; | |
4811 | else if (key.objectid > 0) | |
4812 | key.objectid--; | |
4813 | else | |
4814 | return 1; | |
7bb86316 | 4815 | |
b3b4aa74 | 4816 | btrfs_release_path(path); |
925baedd CM |
4817 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
4818 | if (ret < 0) | |
4819 | return ret; | |
4820 | btrfs_item_key(path->nodes[0], &found_key, 0); | |
4821 | ret = comp_keys(&found_key, &key); | |
4822 | if (ret < 0) | |
4823 | return 0; | |
4824 | return 1; | |
7bb86316 CM |
4825 | } |
4826 | ||
3f157a2f CM |
4827 | /* |
4828 | * A helper function to walk down the tree starting at min_key, and looking | |
4829 | * for nodes or leaves that are either in cache or have a minimum | |
d352ac68 | 4830 | * transaction id. This is used by the btree defrag code, and tree logging |
3f157a2f CM |
4831 | * |
4832 | * This does not cow, but it does stuff the starting key it finds back | |
4833 | * into min_key, so you can call btrfs_search_slot with cow=1 on the | |
4834 | * key and get a writable path. | |
4835 | * | |
4836 | * This does lock as it descends, and path->keep_locks should be set | |
4837 | * to 1 by the caller. | |
4838 | * | |
4839 | * This honors path->lowest_level to prevent descent past a given level | |
4840 | * of the tree. | |
4841 | * | |
d352ac68 CM |
4842 | * min_trans indicates the oldest transaction that you are interested |
4843 | * in walking through. Any nodes or leaves older than min_trans are | |
4844 | * skipped over (without reading them). | |
4845 | * | |
3f157a2f CM |
4846 | * returns zero if something useful was found, < 0 on error and 1 if there |
4847 | * was nothing in the tree that matched the search criteria. | |
4848 | */ | |
4849 | int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key, | |
e02119d5 | 4850 | struct btrfs_key *max_key, |
3f157a2f CM |
4851 | struct btrfs_path *path, int cache_only, |
4852 | u64 min_trans) | |
4853 | { | |
4854 | struct extent_buffer *cur; | |
4855 | struct btrfs_key found_key; | |
4856 | int slot; | |
9652480b | 4857 | int sret; |
3f157a2f CM |
4858 | u32 nritems; |
4859 | int level; | |
4860 | int ret = 1; | |
4861 | ||
934d375b | 4862 | WARN_ON(!path->keep_locks); |
3f157a2f | 4863 | again: |
bd681513 | 4864 | cur = btrfs_read_lock_root_node(root); |
3f157a2f | 4865 | level = btrfs_header_level(cur); |
e02119d5 | 4866 | WARN_ON(path->nodes[level]); |
3f157a2f | 4867 | path->nodes[level] = cur; |
bd681513 | 4868 | path->locks[level] = BTRFS_READ_LOCK; |
3f157a2f CM |
4869 | |
4870 | if (btrfs_header_generation(cur) < min_trans) { | |
4871 | ret = 1; | |
4872 | goto out; | |
4873 | } | |
d397712b | 4874 | while (1) { |
3f157a2f CM |
4875 | nritems = btrfs_header_nritems(cur); |
4876 | level = btrfs_header_level(cur); | |
9652480b | 4877 | sret = bin_search(cur, min_key, level, &slot); |
3f157a2f | 4878 | |
323ac95b CM |
4879 | /* at the lowest level, we're done, setup the path and exit */ |
4880 | if (level == path->lowest_level) { | |
e02119d5 CM |
4881 | if (slot >= nritems) |
4882 | goto find_next_key; | |
3f157a2f CM |
4883 | ret = 0; |
4884 | path->slots[level] = slot; | |
4885 | btrfs_item_key_to_cpu(cur, &found_key, slot); | |
4886 | goto out; | |
4887 | } | |
9652480b Y |
4888 | if (sret && slot > 0) |
4889 | slot--; | |
3f157a2f CM |
4890 | /* |
4891 | * check this node pointer against the cache_only and | |
4892 | * min_trans parameters. If it isn't in cache or is too | |
4893 | * old, skip to the next one. | |
4894 | */ | |
d397712b | 4895 | while (slot < nritems) { |
3f157a2f CM |
4896 | u64 blockptr; |
4897 | u64 gen; | |
4898 | struct extent_buffer *tmp; | |
e02119d5 CM |
4899 | struct btrfs_disk_key disk_key; |
4900 | ||
3f157a2f CM |
4901 | blockptr = btrfs_node_blockptr(cur, slot); |
4902 | gen = btrfs_node_ptr_generation(cur, slot); | |
4903 | if (gen < min_trans) { | |
4904 | slot++; | |
4905 | continue; | |
4906 | } | |
4907 | if (!cache_only) | |
4908 | break; | |
4909 | ||
e02119d5 CM |
4910 | if (max_key) { |
4911 | btrfs_node_key(cur, &disk_key, slot); | |
4912 | if (comp_keys(&disk_key, max_key) >= 0) { | |
4913 | ret = 1; | |
4914 | goto out; | |
4915 | } | |
4916 | } | |
4917 | ||
3f157a2f CM |
4918 | tmp = btrfs_find_tree_block(root, blockptr, |
4919 | btrfs_level_size(root, level - 1)); | |
4920 | ||
b9fab919 | 4921 | if (tmp && btrfs_buffer_uptodate(tmp, gen, 1) > 0) { |
3f157a2f CM |
4922 | free_extent_buffer(tmp); |
4923 | break; | |
4924 | } | |
4925 | if (tmp) | |
4926 | free_extent_buffer(tmp); | |
4927 | slot++; | |
4928 | } | |
e02119d5 | 4929 | find_next_key: |
3f157a2f CM |
4930 | /* |
4931 | * we didn't find a candidate key in this node, walk forward | |
4932 | * and find another one | |
4933 | */ | |
4934 | if (slot >= nritems) { | |
e02119d5 | 4935 | path->slots[level] = slot; |
b4ce94de | 4936 | btrfs_set_path_blocking(path); |
e02119d5 | 4937 | sret = btrfs_find_next_key(root, path, min_key, level, |
3f157a2f | 4938 | cache_only, min_trans); |
e02119d5 | 4939 | if (sret == 0) { |
b3b4aa74 | 4940 | btrfs_release_path(path); |
3f157a2f CM |
4941 | goto again; |
4942 | } else { | |
4943 | goto out; | |
4944 | } | |
4945 | } | |
4946 | /* save our key for returning back */ | |
4947 | btrfs_node_key_to_cpu(cur, &found_key, slot); | |
4948 | path->slots[level] = slot; | |
4949 | if (level == path->lowest_level) { | |
4950 | ret = 0; | |
f7c79f30 | 4951 | unlock_up(path, level, 1, 0, NULL); |
3f157a2f CM |
4952 | goto out; |
4953 | } | |
b4ce94de | 4954 | btrfs_set_path_blocking(path); |
3f157a2f | 4955 | cur = read_node_slot(root, cur, slot); |
79787eaa | 4956 | BUG_ON(!cur); /* -ENOMEM */ |
3f157a2f | 4957 | |
bd681513 | 4958 | btrfs_tree_read_lock(cur); |
b4ce94de | 4959 | |
bd681513 | 4960 | path->locks[level - 1] = BTRFS_READ_LOCK; |
3f157a2f | 4961 | path->nodes[level - 1] = cur; |
f7c79f30 | 4962 | unlock_up(path, level, 1, 0, NULL); |
bd681513 | 4963 | btrfs_clear_path_blocking(path, NULL, 0); |
3f157a2f CM |
4964 | } |
4965 | out: | |
4966 | if (ret == 0) | |
4967 | memcpy(min_key, &found_key, sizeof(found_key)); | |
b4ce94de | 4968 | btrfs_set_path_blocking(path); |
3f157a2f CM |
4969 | return ret; |
4970 | } | |
4971 | ||
7069830a AB |
4972 | static void tree_move_down(struct btrfs_root *root, |
4973 | struct btrfs_path *path, | |
4974 | int *level, int root_level) | |
4975 | { | |
74dd17fb | 4976 | BUG_ON(*level == 0); |
7069830a AB |
4977 | path->nodes[*level - 1] = read_node_slot(root, path->nodes[*level], |
4978 | path->slots[*level]); | |
4979 | path->slots[*level - 1] = 0; | |
4980 | (*level)--; | |
4981 | } | |
4982 | ||
4983 | static int tree_move_next_or_upnext(struct btrfs_root *root, | |
4984 | struct btrfs_path *path, | |
4985 | int *level, int root_level) | |
4986 | { | |
4987 | int ret = 0; | |
4988 | int nritems; | |
4989 | nritems = btrfs_header_nritems(path->nodes[*level]); | |
4990 | ||
4991 | path->slots[*level]++; | |
4992 | ||
74dd17fb | 4993 | while (path->slots[*level] >= nritems) { |
7069830a AB |
4994 | if (*level == root_level) |
4995 | return -1; | |
4996 | ||
4997 | /* move upnext */ | |
4998 | path->slots[*level] = 0; | |
4999 | free_extent_buffer(path->nodes[*level]); | |
5000 | path->nodes[*level] = NULL; | |
5001 | (*level)++; | |
5002 | path->slots[*level]++; | |
5003 | ||
5004 | nritems = btrfs_header_nritems(path->nodes[*level]); | |
5005 | ret = 1; | |
5006 | } | |
5007 | return ret; | |
5008 | } | |
5009 | ||
5010 | /* | |
5011 | * Returns 1 if it had to move up and next. 0 is returned if it moved only next | |
5012 | * or down. | |
5013 | */ | |
5014 | static int tree_advance(struct btrfs_root *root, | |
5015 | struct btrfs_path *path, | |
5016 | int *level, int root_level, | |
5017 | int allow_down, | |
5018 | struct btrfs_key *key) | |
5019 | { | |
5020 | int ret; | |
5021 | ||
5022 | if (*level == 0 || !allow_down) { | |
5023 | ret = tree_move_next_or_upnext(root, path, level, root_level); | |
5024 | } else { | |
5025 | tree_move_down(root, path, level, root_level); | |
5026 | ret = 0; | |
5027 | } | |
5028 | if (ret >= 0) { | |
5029 | if (*level == 0) | |
5030 | btrfs_item_key_to_cpu(path->nodes[*level], key, | |
5031 | path->slots[*level]); | |
5032 | else | |
5033 | btrfs_node_key_to_cpu(path->nodes[*level], key, | |
5034 | path->slots[*level]); | |
5035 | } | |
5036 | return ret; | |
5037 | } | |
5038 | ||
5039 | static int tree_compare_item(struct btrfs_root *left_root, | |
5040 | struct btrfs_path *left_path, | |
5041 | struct btrfs_path *right_path, | |
5042 | char *tmp_buf) | |
5043 | { | |
5044 | int cmp; | |
5045 | int len1, len2; | |
5046 | unsigned long off1, off2; | |
5047 | ||
5048 | len1 = btrfs_item_size_nr(left_path->nodes[0], left_path->slots[0]); | |
5049 | len2 = btrfs_item_size_nr(right_path->nodes[0], right_path->slots[0]); | |
5050 | if (len1 != len2) | |
5051 | return 1; | |
5052 | ||
5053 | off1 = btrfs_item_ptr_offset(left_path->nodes[0], left_path->slots[0]); | |
5054 | off2 = btrfs_item_ptr_offset(right_path->nodes[0], | |
5055 | right_path->slots[0]); | |
5056 | ||
5057 | read_extent_buffer(left_path->nodes[0], tmp_buf, off1, len1); | |
5058 | ||
5059 | cmp = memcmp_extent_buffer(right_path->nodes[0], tmp_buf, off2, len1); | |
5060 | if (cmp) | |
5061 | return 1; | |
5062 | return 0; | |
5063 | } | |
5064 | ||
5065 | #define ADVANCE 1 | |
5066 | #define ADVANCE_ONLY_NEXT -1 | |
5067 | ||
5068 | /* | |
5069 | * This function compares two trees and calls the provided callback for | |
5070 | * every changed/new/deleted item it finds. | |
5071 | * If shared tree blocks are encountered, whole subtrees are skipped, making | |
5072 | * the compare pretty fast on snapshotted subvolumes. | |
5073 | * | |
5074 | * This currently works on commit roots only. As commit roots are read only, | |
5075 | * we don't do any locking. The commit roots are protected with transactions. | |
5076 | * Transactions are ended and rejoined when a commit is tried in between. | |
5077 | * | |
5078 | * This function checks for modifications done to the trees while comparing. | |
5079 | * If it detects a change, it aborts immediately. | |
5080 | */ | |
5081 | int btrfs_compare_trees(struct btrfs_root *left_root, | |
5082 | struct btrfs_root *right_root, | |
5083 | btrfs_changed_cb_t changed_cb, void *ctx) | |
5084 | { | |
5085 | int ret; | |
5086 | int cmp; | |
5087 | struct btrfs_trans_handle *trans = NULL; | |
5088 | struct btrfs_path *left_path = NULL; | |
5089 | struct btrfs_path *right_path = NULL; | |
5090 | struct btrfs_key left_key; | |
5091 | struct btrfs_key right_key; | |
5092 | char *tmp_buf = NULL; | |
5093 | int left_root_level; | |
5094 | int right_root_level; | |
5095 | int left_level; | |
5096 | int right_level; | |
5097 | int left_end_reached; | |
5098 | int right_end_reached; | |
5099 | int advance_left; | |
5100 | int advance_right; | |
5101 | u64 left_blockptr; | |
5102 | u64 right_blockptr; | |
5103 | u64 left_start_ctransid; | |
5104 | u64 right_start_ctransid; | |
5105 | u64 ctransid; | |
5106 | ||
5107 | left_path = btrfs_alloc_path(); | |
5108 | if (!left_path) { | |
5109 | ret = -ENOMEM; | |
5110 | goto out; | |
5111 | } | |
5112 | right_path = btrfs_alloc_path(); | |
5113 | if (!right_path) { | |
5114 | ret = -ENOMEM; | |
5115 | goto out; | |
5116 | } | |
5117 | ||
5118 | tmp_buf = kmalloc(left_root->leafsize, GFP_NOFS); | |
5119 | if (!tmp_buf) { | |
5120 | ret = -ENOMEM; | |
5121 | goto out; | |
5122 | } | |
5123 | ||
5124 | left_path->search_commit_root = 1; | |
5125 | left_path->skip_locking = 1; | |
5126 | right_path->search_commit_root = 1; | |
5127 | right_path->skip_locking = 1; | |
5128 | ||
5f3ab90a | 5129 | spin_lock(&left_root->root_item_lock); |
7069830a | 5130 | left_start_ctransid = btrfs_root_ctransid(&left_root->root_item); |
5f3ab90a | 5131 | spin_unlock(&left_root->root_item_lock); |
7069830a | 5132 | |
5f3ab90a | 5133 | spin_lock(&right_root->root_item_lock); |
7069830a | 5134 | right_start_ctransid = btrfs_root_ctransid(&right_root->root_item); |
5f3ab90a | 5135 | spin_unlock(&right_root->root_item_lock); |
7069830a AB |
5136 | |
5137 | trans = btrfs_join_transaction(left_root); | |
5138 | if (IS_ERR(trans)) { | |
5139 | ret = PTR_ERR(trans); | |
5140 | trans = NULL; | |
5141 | goto out; | |
5142 | } | |
5143 | ||
5144 | /* | |
5145 | * Strategy: Go to the first items of both trees. Then do | |
5146 | * | |
5147 | * If both trees are at level 0 | |
5148 | * Compare keys of current items | |
5149 | * If left < right treat left item as new, advance left tree | |
5150 | * and repeat | |
5151 | * If left > right treat right item as deleted, advance right tree | |
5152 | * and repeat | |
5153 | * If left == right do deep compare of items, treat as changed if | |
5154 | * needed, advance both trees and repeat | |
5155 | * If both trees are at the same level but not at level 0 | |
5156 | * Compare keys of current nodes/leafs | |
5157 | * If left < right advance left tree and repeat | |
5158 | * If left > right advance right tree and repeat | |
5159 | * If left == right compare blockptrs of the next nodes/leafs | |
5160 | * If they match advance both trees but stay at the same level | |
5161 | * and repeat | |
5162 | * If they don't match advance both trees while allowing to go | |
5163 | * deeper and repeat | |
5164 | * If tree levels are different | |
5165 | * Advance the tree that needs it and repeat | |
5166 | * | |
5167 | * Advancing a tree means: | |
5168 | * If we are at level 0, try to go to the next slot. If that's not | |
5169 | * possible, go one level up and repeat. Stop when we found a level | |
5170 | * where we could go to the next slot. We may at this point be on a | |
5171 | * node or a leaf. | |
5172 | * | |
5173 | * If we are not at level 0 and not on shared tree blocks, go one | |
5174 | * level deeper. | |
5175 | * | |
5176 | * If we are not at level 0 and on shared tree blocks, go one slot to | |
5177 | * the right if possible or go up and right. | |
5178 | */ | |
5179 | ||
5180 | left_level = btrfs_header_level(left_root->commit_root); | |
5181 | left_root_level = left_level; | |
5182 | left_path->nodes[left_level] = left_root->commit_root; | |
5183 | extent_buffer_get(left_path->nodes[left_level]); | |
5184 | ||
5185 | right_level = btrfs_header_level(right_root->commit_root); | |
5186 | right_root_level = right_level; | |
5187 | right_path->nodes[right_level] = right_root->commit_root; | |
5188 | extent_buffer_get(right_path->nodes[right_level]); | |
5189 | ||
5190 | if (left_level == 0) | |
5191 | btrfs_item_key_to_cpu(left_path->nodes[left_level], | |
5192 | &left_key, left_path->slots[left_level]); | |
5193 | else | |
5194 | btrfs_node_key_to_cpu(left_path->nodes[left_level], | |
5195 | &left_key, left_path->slots[left_level]); | |
5196 | if (right_level == 0) | |
5197 | btrfs_item_key_to_cpu(right_path->nodes[right_level], | |
5198 | &right_key, right_path->slots[right_level]); | |
5199 | else | |
5200 | btrfs_node_key_to_cpu(right_path->nodes[right_level], | |
5201 | &right_key, right_path->slots[right_level]); | |
5202 | ||
5203 | left_end_reached = right_end_reached = 0; | |
5204 | advance_left = advance_right = 0; | |
5205 | ||
5206 | while (1) { | |
5207 | /* | |
5208 | * We need to make sure the transaction does not get committed | |
5209 | * while we do anything on commit roots. This means, we need to | |
5210 | * join and leave transactions for every item that we process. | |
5211 | */ | |
5212 | if (trans && btrfs_should_end_transaction(trans, left_root)) { | |
5213 | btrfs_release_path(left_path); | |
5214 | btrfs_release_path(right_path); | |
5215 | ||
5216 | ret = btrfs_end_transaction(trans, left_root); | |
5217 | trans = NULL; | |
5218 | if (ret < 0) | |
5219 | goto out; | |
5220 | } | |
5221 | /* now rejoin the transaction */ | |
5222 | if (!trans) { | |
5223 | trans = btrfs_join_transaction(left_root); | |
5224 | if (IS_ERR(trans)) { | |
5225 | ret = PTR_ERR(trans); | |
5226 | trans = NULL; | |
5227 | goto out; | |
5228 | } | |
5229 | ||
5f3ab90a | 5230 | spin_lock(&left_root->root_item_lock); |
7069830a | 5231 | ctransid = btrfs_root_ctransid(&left_root->root_item); |
5f3ab90a | 5232 | spin_unlock(&left_root->root_item_lock); |
7069830a AB |
5233 | if (ctransid != left_start_ctransid) |
5234 | left_start_ctransid = 0; | |
5235 | ||
5f3ab90a | 5236 | spin_lock(&right_root->root_item_lock); |
7069830a | 5237 | ctransid = btrfs_root_ctransid(&right_root->root_item); |
5f3ab90a | 5238 | spin_unlock(&right_root->root_item_lock); |
7069830a AB |
5239 | if (ctransid != right_start_ctransid) |
5240 | right_start_ctransid = 0; | |
5241 | ||
5242 | if (!left_start_ctransid || !right_start_ctransid) { | |
5243 | WARN(1, KERN_WARNING | |
5244 | "btrfs: btrfs_compare_tree detected " | |
5245 | "a change in one of the trees while " | |
5246 | "iterating. This is probably a " | |
5247 | "bug.\n"); | |
5248 | ret = -EIO; | |
5249 | goto out; | |
5250 | } | |
5251 | ||
5252 | /* | |
5253 | * the commit root may have changed, so start again | |
5254 | * where we stopped | |
5255 | */ | |
5256 | left_path->lowest_level = left_level; | |
5257 | right_path->lowest_level = right_level; | |
5258 | ret = btrfs_search_slot(NULL, left_root, | |
5259 | &left_key, left_path, 0, 0); | |
5260 | if (ret < 0) | |
5261 | goto out; | |
5262 | ret = btrfs_search_slot(NULL, right_root, | |
5263 | &right_key, right_path, 0, 0); | |
5264 | if (ret < 0) | |
5265 | goto out; | |
5266 | } | |
5267 | ||
5268 | if (advance_left && !left_end_reached) { | |
5269 | ret = tree_advance(left_root, left_path, &left_level, | |
5270 | left_root_level, | |
5271 | advance_left != ADVANCE_ONLY_NEXT, | |
5272 | &left_key); | |
5273 | if (ret < 0) | |
5274 | left_end_reached = ADVANCE; | |
5275 | advance_left = 0; | |
5276 | } | |
5277 | if (advance_right && !right_end_reached) { | |
5278 | ret = tree_advance(right_root, right_path, &right_level, | |
5279 | right_root_level, | |
5280 | advance_right != ADVANCE_ONLY_NEXT, | |
5281 | &right_key); | |
5282 | if (ret < 0) | |
5283 | right_end_reached = ADVANCE; | |
5284 | advance_right = 0; | |
5285 | } | |
5286 | ||
5287 | if (left_end_reached && right_end_reached) { | |
5288 | ret = 0; | |
5289 | goto out; | |
5290 | } else if (left_end_reached) { | |
5291 | if (right_level == 0) { | |
5292 | ret = changed_cb(left_root, right_root, | |
5293 | left_path, right_path, | |
5294 | &right_key, | |
5295 | BTRFS_COMPARE_TREE_DELETED, | |
5296 | ctx); | |
5297 | if (ret < 0) | |
5298 | goto out; | |
5299 | } | |
5300 | advance_right = ADVANCE; | |
5301 | continue; | |
5302 | } else if (right_end_reached) { | |
5303 | if (left_level == 0) { | |
5304 | ret = changed_cb(left_root, right_root, | |
5305 | left_path, right_path, | |
5306 | &left_key, | |
5307 | BTRFS_COMPARE_TREE_NEW, | |
5308 | ctx); | |
5309 | if (ret < 0) | |
5310 | goto out; | |
5311 | } | |
5312 | advance_left = ADVANCE; | |
5313 | continue; | |
5314 | } | |
5315 | ||
5316 | if (left_level == 0 && right_level == 0) { | |
5317 | cmp = btrfs_comp_cpu_keys(&left_key, &right_key); | |
5318 | if (cmp < 0) { | |
5319 | ret = changed_cb(left_root, right_root, | |
5320 | left_path, right_path, | |
5321 | &left_key, | |
5322 | BTRFS_COMPARE_TREE_NEW, | |
5323 | ctx); | |
5324 | if (ret < 0) | |
5325 | goto out; | |
5326 | advance_left = ADVANCE; | |
5327 | } else if (cmp > 0) { | |
5328 | ret = changed_cb(left_root, right_root, | |
5329 | left_path, right_path, | |
5330 | &right_key, | |
5331 | BTRFS_COMPARE_TREE_DELETED, | |
5332 | ctx); | |
5333 | if (ret < 0) | |
5334 | goto out; | |
5335 | advance_right = ADVANCE; | |
5336 | } else { | |
74dd17fb | 5337 | WARN_ON(!extent_buffer_uptodate(left_path->nodes[0])); |
7069830a AB |
5338 | ret = tree_compare_item(left_root, left_path, |
5339 | right_path, tmp_buf); | |
5340 | if (ret) { | |
74dd17fb | 5341 | WARN_ON(!extent_buffer_uptodate(left_path->nodes[0])); |
7069830a AB |
5342 | ret = changed_cb(left_root, right_root, |
5343 | left_path, right_path, | |
5344 | &left_key, | |
5345 | BTRFS_COMPARE_TREE_CHANGED, | |
5346 | ctx); | |
5347 | if (ret < 0) | |
5348 | goto out; | |
5349 | } | |
5350 | advance_left = ADVANCE; | |
5351 | advance_right = ADVANCE; | |
5352 | } | |
5353 | } else if (left_level == right_level) { | |
5354 | cmp = btrfs_comp_cpu_keys(&left_key, &right_key); | |
5355 | if (cmp < 0) { | |
5356 | advance_left = ADVANCE; | |
5357 | } else if (cmp > 0) { | |
5358 | advance_right = ADVANCE; | |
5359 | } else { | |
5360 | left_blockptr = btrfs_node_blockptr( | |
5361 | left_path->nodes[left_level], | |
5362 | left_path->slots[left_level]); | |
5363 | right_blockptr = btrfs_node_blockptr( | |
5364 | right_path->nodes[right_level], | |
5365 | right_path->slots[right_level]); | |
5366 | if (left_blockptr == right_blockptr) { | |
5367 | /* | |
5368 | * As we're on a shared block, don't | |
5369 | * allow to go deeper. | |
5370 | */ | |
5371 | advance_left = ADVANCE_ONLY_NEXT; | |
5372 | advance_right = ADVANCE_ONLY_NEXT; | |
5373 | } else { | |
5374 | advance_left = ADVANCE; | |
5375 | advance_right = ADVANCE; | |
5376 | } | |
5377 | } | |
5378 | } else if (left_level < right_level) { | |
5379 | advance_right = ADVANCE; | |
5380 | } else { | |
5381 | advance_left = ADVANCE; | |
5382 | } | |
5383 | } | |
5384 | ||
5385 | out: | |
5386 | btrfs_free_path(left_path); | |
5387 | btrfs_free_path(right_path); | |
5388 | kfree(tmp_buf); | |
5389 | ||
5390 | if (trans) { | |
5391 | if (!ret) | |
5392 | ret = btrfs_end_transaction(trans, left_root); | |
5393 | else | |
5394 | btrfs_end_transaction(trans, left_root); | |
5395 | } | |
5396 | ||
5397 | return ret; | |
5398 | } | |
5399 | ||
3f157a2f CM |
5400 | /* |
5401 | * this is similar to btrfs_next_leaf, but does not try to preserve | |
5402 | * and fixup the path. It looks for and returns the next key in the | |
5403 | * tree based on the current path and the cache_only and min_trans | |
5404 | * parameters. | |
5405 | * | |
5406 | * 0 is returned if another key is found, < 0 if there are any errors | |
5407 | * and 1 is returned if there are no higher keys in the tree | |
5408 | * | |
5409 | * path->keep_locks should be set to 1 on the search made before | |
5410 | * calling this function. | |
5411 | */ | |
e7a84565 | 5412 | int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path, |
33c66f43 | 5413 | struct btrfs_key *key, int level, |
3f157a2f | 5414 | int cache_only, u64 min_trans) |
e7a84565 | 5415 | { |
e7a84565 CM |
5416 | int slot; |
5417 | struct extent_buffer *c; | |
5418 | ||
934d375b | 5419 | WARN_ON(!path->keep_locks); |
d397712b | 5420 | while (level < BTRFS_MAX_LEVEL) { |
e7a84565 CM |
5421 | if (!path->nodes[level]) |
5422 | return 1; | |
5423 | ||
5424 | slot = path->slots[level] + 1; | |
5425 | c = path->nodes[level]; | |
3f157a2f | 5426 | next: |
e7a84565 | 5427 | if (slot >= btrfs_header_nritems(c)) { |
33c66f43 YZ |
5428 | int ret; |
5429 | int orig_lowest; | |
5430 | struct btrfs_key cur_key; | |
5431 | if (level + 1 >= BTRFS_MAX_LEVEL || | |
5432 | !path->nodes[level + 1]) | |
e7a84565 | 5433 | return 1; |
33c66f43 YZ |
5434 | |
5435 | if (path->locks[level + 1]) { | |
5436 | level++; | |
5437 | continue; | |
5438 | } | |
5439 | ||
5440 | slot = btrfs_header_nritems(c) - 1; | |
5441 | if (level == 0) | |
5442 | btrfs_item_key_to_cpu(c, &cur_key, slot); | |
5443 | else | |
5444 | btrfs_node_key_to_cpu(c, &cur_key, slot); | |
5445 | ||
5446 | orig_lowest = path->lowest_level; | |
b3b4aa74 | 5447 | btrfs_release_path(path); |
33c66f43 YZ |
5448 | path->lowest_level = level; |
5449 | ret = btrfs_search_slot(NULL, root, &cur_key, path, | |
5450 | 0, 0); | |
5451 | path->lowest_level = orig_lowest; | |
5452 | if (ret < 0) | |
5453 | return ret; | |
5454 | ||
5455 | c = path->nodes[level]; | |
5456 | slot = path->slots[level]; | |
5457 | if (ret == 0) | |
5458 | slot++; | |
5459 | goto next; | |
e7a84565 | 5460 | } |
33c66f43 | 5461 | |
e7a84565 CM |
5462 | if (level == 0) |
5463 | btrfs_item_key_to_cpu(c, key, slot); | |
3f157a2f CM |
5464 | else { |
5465 | u64 blockptr = btrfs_node_blockptr(c, slot); | |
5466 | u64 gen = btrfs_node_ptr_generation(c, slot); | |
5467 | ||
5468 | if (cache_only) { | |
5469 | struct extent_buffer *cur; | |
5470 | cur = btrfs_find_tree_block(root, blockptr, | |
5471 | btrfs_level_size(root, level - 1)); | |
b9fab919 CM |
5472 | if (!cur || |
5473 | btrfs_buffer_uptodate(cur, gen, 1) <= 0) { | |
3f157a2f CM |
5474 | slot++; |
5475 | if (cur) | |
5476 | free_extent_buffer(cur); | |
5477 | goto next; | |
5478 | } | |
5479 | free_extent_buffer(cur); | |
5480 | } | |
5481 | if (gen < min_trans) { | |
5482 | slot++; | |
5483 | goto next; | |
5484 | } | |
e7a84565 | 5485 | btrfs_node_key_to_cpu(c, key, slot); |
3f157a2f | 5486 | } |
e7a84565 CM |
5487 | return 0; |
5488 | } | |
5489 | return 1; | |
5490 | } | |
5491 | ||
97571fd0 | 5492 | /* |
925baedd | 5493 | * search the tree again to find a leaf with greater keys |
0f70abe2 CM |
5494 | * returns 0 if it found something or 1 if there are no greater leaves. |
5495 | * returns < 0 on io errors. | |
97571fd0 | 5496 | */ |
234b63a0 | 5497 | int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path) |
3d7806ec JS |
5498 | { |
5499 | return btrfs_next_old_leaf(root, path, 0); | |
5500 | } | |
5501 | ||
70c8a91c JB |
5502 | /* Release the path up to but not including the given level */ |
5503 | static void btrfs_release_level(struct btrfs_path *path, int level) | |
5504 | { | |
5505 | int i; | |
5506 | ||
5507 | for (i = 0; i < level; i++) { | |
5508 | path->slots[i] = 0; | |
5509 | if (!path->nodes[i]) | |
5510 | continue; | |
5511 | if (path->locks[i]) { | |
5512 | btrfs_tree_unlock_rw(path->nodes[i], path->locks[i]); | |
5513 | path->locks[i] = 0; | |
5514 | } | |
5515 | free_extent_buffer(path->nodes[i]); | |
5516 | path->nodes[i] = NULL; | |
5517 | } | |
5518 | } | |
5519 | ||
5520 | /* | |
5521 | * This function assumes 2 things | |
5522 | * | |
5523 | * 1) You are using path->keep_locks | |
5524 | * 2) You are not inserting items. | |
5525 | * | |
5526 | * If either of these are not true do not use this function. If you need a next | |
5527 | * leaf with either of these not being true then this function can be easily | |
5528 | * adapted to do that, but at the moment these are the limitations. | |
5529 | */ | |
5530 | int btrfs_next_leaf_write(struct btrfs_trans_handle *trans, | |
5531 | struct btrfs_root *root, struct btrfs_path *path, | |
5532 | int del) | |
5533 | { | |
5534 | struct extent_buffer *b; | |
5535 | struct btrfs_key key; | |
5536 | u32 nritems; | |
5537 | int level = 1; | |
5538 | int slot; | |
5539 | int ret = 1; | |
5540 | int write_lock_level = BTRFS_MAX_LEVEL; | |
5541 | int ins_len = del ? -1 : 0; | |
5542 | ||
5543 | WARN_ON(!(path->keep_locks || path->really_keep_locks)); | |
5544 | ||
5545 | nritems = btrfs_header_nritems(path->nodes[0]); | |
5546 | btrfs_item_key_to_cpu(path->nodes[0], &key, nritems - 1); | |
5547 | ||
5548 | while (path->nodes[level]) { | |
5549 | nritems = btrfs_header_nritems(path->nodes[level]); | |
5550 | if (!(path->locks[level] & BTRFS_WRITE_LOCK)) { | |
5551 | search: | |
5552 | btrfs_release_path(path); | |
5553 | ret = btrfs_search_slot(trans, root, &key, path, | |
5554 | ins_len, 1); | |
5555 | if (ret < 0) | |
5556 | goto out; | |
5557 | level = 1; | |
5558 | continue; | |
5559 | } | |
5560 | ||
5561 | if (path->slots[level] >= nritems - 1) { | |
5562 | level++; | |
5563 | continue; | |
5564 | } | |
5565 | ||
5566 | btrfs_release_level(path, level); | |
5567 | break; | |
5568 | } | |
5569 | ||
5570 | if (!path->nodes[level]) { | |
5571 | ret = 1; | |
5572 | goto out; | |
5573 | } | |
5574 | ||
5575 | path->slots[level]++; | |
5576 | b = path->nodes[level]; | |
5577 | ||
5578 | while (b) { | |
5579 | level = btrfs_header_level(b); | |
5580 | ||
5581 | if (!should_cow_block(trans, root, b)) | |
5582 | goto cow_done; | |
5583 | ||
5584 | btrfs_set_path_blocking(path); | |
5585 | ret = btrfs_cow_block(trans, root, b, | |
5586 | path->nodes[level + 1], | |
5587 | path->slots[level + 1], &b); | |
5588 | if (ret) | |
5589 | goto out; | |
5590 | cow_done: | |
5591 | path->nodes[level] = b; | |
5592 | btrfs_clear_path_blocking(path, NULL, 0); | |
5593 | if (level != 0) { | |
5594 | ret = setup_nodes_for_search(trans, root, path, b, | |
5595 | level, ins_len, | |
5596 | &write_lock_level); | |
5597 | if (ret == -EAGAIN) | |
5598 | goto search; | |
5599 | if (ret) | |
5600 | goto out; | |
5601 | ||
5602 | b = path->nodes[level]; | |
5603 | slot = path->slots[level]; | |
5604 | ||
5605 | ret = read_block_for_search(trans, root, path, | |
5606 | &b, level, slot, &key, 0); | |
5607 | if (ret == -EAGAIN) | |
5608 | goto search; | |
5609 | if (ret) | |
5610 | goto out; | |
5611 | level = btrfs_header_level(b); | |
5612 | if (!btrfs_try_tree_write_lock(b)) { | |
5613 | btrfs_set_path_blocking(path); | |
5614 | btrfs_tree_lock(b); | |
5615 | btrfs_clear_path_blocking(path, b, | |
5616 | BTRFS_WRITE_LOCK); | |
5617 | } | |
5618 | path->locks[level] = BTRFS_WRITE_LOCK; | |
5619 | path->nodes[level] = b; | |
5620 | path->slots[level] = 0; | |
5621 | } else { | |
5622 | path->slots[level] = 0; | |
5623 | ret = 0; | |
5624 | break; | |
5625 | } | |
5626 | } | |
5627 | ||
5628 | out: | |
5629 | if (ret) | |
5630 | btrfs_release_path(path); | |
5631 | ||
5632 | return ret; | |
5633 | } | |
5634 | ||
3d7806ec JS |
5635 | int btrfs_next_old_leaf(struct btrfs_root *root, struct btrfs_path *path, |
5636 | u64 time_seq) | |
d97e63b6 CM |
5637 | { |
5638 | int slot; | |
8e73f275 | 5639 | int level; |
5f39d397 | 5640 | struct extent_buffer *c; |
8e73f275 | 5641 | struct extent_buffer *next; |
925baedd CM |
5642 | struct btrfs_key key; |
5643 | u32 nritems; | |
5644 | int ret; | |
8e73f275 | 5645 | int old_spinning = path->leave_spinning; |
bd681513 | 5646 | int next_rw_lock = 0; |
925baedd CM |
5647 | |
5648 | nritems = btrfs_header_nritems(path->nodes[0]); | |
d397712b | 5649 | if (nritems == 0) |
925baedd | 5650 | return 1; |
925baedd | 5651 | |
8e73f275 CM |
5652 | btrfs_item_key_to_cpu(path->nodes[0], &key, nritems - 1); |
5653 | again: | |
5654 | level = 1; | |
5655 | next = NULL; | |
bd681513 | 5656 | next_rw_lock = 0; |
b3b4aa74 | 5657 | btrfs_release_path(path); |
8e73f275 | 5658 | |
a2135011 | 5659 | path->keep_locks = 1; |
31533fb2 | 5660 | path->leave_spinning = 1; |
8e73f275 | 5661 | |
3d7806ec JS |
5662 | if (time_seq) |
5663 | ret = btrfs_search_old_slot(root, &key, path, time_seq); | |
5664 | else | |
5665 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); | |
925baedd CM |
5666 | path->keep_locks = 0; |
5667 | ||
5668 | if (ret < 0) | |
5669 | return ret; | |
5670 | ||
a2135011 | 5671 | nritems = btrfs_header_nritems(path->nodes[0]); |
168fd7d2 CM |
5672 | /* |
5673 | * by releasing the path above we dropped all our locks. A balance | |
5674 | * could have added more items next to the key that used to be | |
5675 | * at the very end of the block. So, check again here and | |
5676 | * advance the path if there are now more items available. | |
5677 | */ | |
a2135011 | 5678 | if (nritems > 0 && path->slots[0] < nritems - 1) { |
e457afec YZ |
5679 | if (ret == 0) |
5680 | path->slots[0]++; | |
8e73f275 | 5681 | ret = 0; |
925baedd CM |
5682 | goto done; |
5683 | } | |
d97e63b6 | 5684 | |
d397712b | 5685 | while (level < BTRFS_MAX_LEVEL) { |
8e73f275 CM |
5686 | if (!path->nodes[level]) { |
5687 | ret = 1; | |
5688 | goto done; | |
5689 | } | |
5f39d397 | 5690 | |
d97e63b6 CM |
5691 | slot = path->slots[level] + 1; |
5692 | c = path->nodes[level]; | |
5f39d397 | 5693 | if (slot >= btrfs_header_nritems(c)) { |
d97e63b6 | 5694 | level++; |
8e73f275 CM |
5695 | if (level == BTRFS_MAX_LEVEL) { |
5696 | ret = 1; | |
5697 | goto done; | |
5698 | } | |
d97e63b6 CM |
5699 | continue; |
5700 | } | |
5f39d397 | 5701 | |
925baedd | 5702 | if (next) { |
bd681513 | 5703 | btrfs_tree_unlock_rw(next, next_rw_lock); |
5f39d397 | 5704 | free_extent_buffer(next); |
925baedd | 5705 | } |
5f39d397 | 5706 | |
8e73f275 | 5707 | next = c; |
bd681513 | 5708 | next_rw_lock = path->locks[level]; |
8e73f275 | 5709 | ret = read_block_for_search(NULL, root, path, &next, level, |
5d9e75c4 | 5710 | slot, &key, 0); |
8e73f275 CM |
5711 | if (ret == -EAGAIN) |
5712 | goto again; | |
5f39d397 | 5713 | |
76a05b35 | 5714 | if (ret < 0) { |
b3b4aa74 | 5715 | btrfs_release_path(path); |
76a05b35 CM |
5716 | goto done; |
5717 | } | |
5718 | ||
5cd57b2c | 5719 | if (!path->skip_locking) { |
bd681513 | 5720 | ret = btrfs_try_tree_read_lock(next); |
d42244a0 JS |
5721 | if (!ret && time_seq) { |
5722 | /* | |
5723 | * If we don't get the lock, we may be racing | |
5724 | * with push_leaf_left, holding that lock while | |
5725 | * itself waiting for the leaf we've currently | |
5726 | * locked. To solve this situation, we give up | |
5727 | * on our lock and cycle. | |
5728 | */ | |
cf538830 | 5729 | free_extent_buffer(next); |
d42244a0 JS |
5730 | btrfs_release_path(path); |
5731 | cond_resched(); | |
5732 | goto again; | |
5733 | } | |
8e73f275 CM |
5734 | if (!ret) { |
5735 | btrfs_set_path_blocking(path); | |
bd681513 | 5736 | btrfs_tree_read_lock(next); |
31533fb2 | 5737 | btrfs_clear_path_blocking(path, next, |
bd681513 | 5738 | BTRFS_READ_LOCK); |
8e73f275 | 5739 | } |
31533fb2 | 5740 | next_rw_lock = BTRFS_READ_LOCK; |
5cd57b2c | 5741 | } |
d97e63b6 CM |
5742 | break; |
5743 | } | |
5744 | path->slots[level] = slot; | |
d397712b | 5745 | while (1) { |
d97e63b6 CM |
5746 | level--; |
5747 | c = path->nodes[level]; | |
925baedd | 5748 | if (path->locks[level]) |
bd681513 | 5749 | btrfs_tree_unlock_rw(c, path->locks[level]); |
8e73f275 | 5750 | |
5f39d397 | 5751 | free_extent_buffer(c); |
d97e63b6 CM |
5752 | path->nodes[level] = next; |
5753 | path->slots[level] = 0; | |
a74a4b97 | 5754 | if (!path->skip_locking) |
bd681513 | 5755 | path->locks[level] = next_rw_lock; |
d97e63b6 CM |
5756 | if (!level) |
5757 | break; | |
b4ce94de | 5758 | |
8e73f275 | 5759 | ret = read_block_for_search(NULL, root, path, &next, level, |
5d9e75c4 | 5760 | 0, &key, 0); |
8e73f275 CM |
5761 | if (ret == -EAGAIN) |
5762 | goto again; | |
5763 | ||
76a05b35 | 5764 | if (ret < 0) { |
b3b4aa74 | 5765 | btrfs_release_path(path); |
76a05b35 CM |
5766 | goto done; |
5767 | } | |
5768 | ||
5cd57b2c | 5769 | if (!path->skip_locking) { |
bd681513 | 5770 | ret = btrfs_try_tree_read_lock(next); |
8e73f275 CM |
5771 | if (!ret) { |
5772 | btrfs_set_path_blocking(path); | |
bd681513 | 5773 | btrfs_tree_read_lock(next); |
31533fb2 | 5774 | btrfs_clear_path_blocking(path, next, |
bd681513 CM |
5775 | BTRFS_READ_LOCK); |
5776 | } | |
31533fb2 | 5777 | next_rw_lock = BTRFS_READ_LOCK; |
5cd57b2c | 5778 | } |
d97e63b6 | 5779 | } |
8e73f275 | 5780 | ret = 0; |
925baedd | 5781 | done: |
f7c79f30 | 5782 | unlock_up(path, 0, 1, 0, NULL); |
8e73f275 CM |
5783 | path->leave_spinning = old_spinning; |
5784 | if (!old_spinning) | |
5785 | btrfs_set_path_blocking(path); | |
5786 | ||
5787 | return ret; | |
d97e63b6 | 5788 | } |
0b86a832 | 5789 | |
3f157a2f CM |
5790 | /* |
5791 | * this uses btrfs_prev_leaf to walk backwards in the tree, and keeps | |
5792 | * searching until it gets past min_objectid or finds an item of 'type' | |
5793 | * | |
5794 | * returns 0 if something is found, 1 if nothing was found and < 0 on error | |
5795 | */ | |
0b86a832 CM |
5796 | int btrfs_previous_item(struct btrfs_root *root, |
5797 | struct btrfs_path *path, u64 min_objectid, | |
5798 | int type) | |
5799 | { | |
5800 | struct btrfs_key found_key; | |
5801 | struct extent_buffer *leaf; | |
e02119d5 | 5802 | u32 nritems; |
0b86a832 CM |
5803 | int ret; |
5804 | ||
d397712b | 5805 | while (1) { |
0b86a832 | 5806 | if (path->slots[0] == 0) { |
b4ce94de | 5807 | btrfs_set_path_blocking(path); |
0b86a832 CM |
5808 | ret = btrfs_prev_leaf(root, path); |
5809 | if (ret != 0) | |
5810 | return ret; | |
5811 | } else { | |
5812 | path->slots[0]--; | |
5813 | } | |
5814 | leaf = path->nodes[0]; | |
e02119d5 CM |
5815 | nritems = btrfs_header_nritems(leaf); |
5816 | if (nritems == 0) | |
5817 | return 1; | |
5818 | if (path->slots[0] == nritems) | |
5819 | path->slots[0]--; | |
5820 | ||
0b86a832 | 5821 | btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); |
e02119d5 CM |
5822 | if (found_key.objectid < min_objectid) |
5823 | break; | |
0a4eefbb YZ |
5824 | if (found_key.type == type) |
5825 | return 0; | |
e02119d5 CM |
5826 | if (found_key.objectid == min_objectid && |
5827 | found_key.type < type) | |
5828 | break; | |
0b86a832 CM |
5829 | } |
5830 | return 1; | |
5831 | } |