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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, |
f3ea38da JS |
41 | struct btrfs_path *path, int level, int slot, |
42 | int tree_mod_log); | |
f230475e JS |
43 | static void tree_mod_log_free_eb(struct btrfs_fs_info *fs_info, |
44 | struct extent_buffer *eb); | |
45 | struct extent_buffer *read_old_tree_block(struct btrfs_root *root, u64 bytenr, | |
46 | u32 blocksize, u64 parent_transid, | |
47 | u64 time_seq); | |
48 | struct extent_buffer *btrfs_find_old_tree_block(struct btrfs_root *root, | |
49 | u64 bytenr, u32 blocksize, | |
50 | u64 time_seq); | |
d97e63b6 | 51 | |
df24a2b9 | 52 | struct btrfs_path *btrfs_alloc_path(void) |
2c90e5d6 | 53 | { |
df24a2b9 | 54 | struct btrfs_path *path; |
e00f7308 | 55 | path = kmem_cache_zalloc(btrfs_path_cachep, GFP_NOFS); |
df24a2b9 | 56 | return path; |
2c90e5d6 CM |
57 | } |
58 | ||
b4ce94de CM |
59 | /* |
60 | * set all locked nodes in the path to blocking locks. This should | |
61 | * be done before scheduling | |
62 | */ | |
63 | noinline void btrfs_set_path_blocking(struct btrfs_path *p) | |
64 | { | |
65 | int i; | |
66 | for (i = 0; i < BTRFS_MAX_LEVEL; i++) { | |
bd681513 CM |
67 | if (!p->nodes[i] || !p->locks[i]) |
68 | continue; | |
69 | btrfs_set_lock_blocking_rw(p->nodes[i], p->locks[i]); | |
70 | if (p->locks[i] == BTRFS_READ_LOCK) | |
71 | p->locks[i] = BTRFS_READ_LOCK_BLOCKING; | |
72 | else if (p->locks[i] == BTRFS_WRITE_LOCK) | |
73 | p->locks[i] = BTRFS_WRITE_LOCK_BLOCKING; | |
b4ce94de CM |
74 | } |
75 | } | |
76 | ||
77 | /* | |
78 | * reset all the locked nodes in the patch to spinning locks. | |
4008c04a CM |
79 | * |
80 | * held is used to keep lockdep happy, when lockdep is enabled | |
81 | * we set held to a blocking lock before we go around and | |
82 | * retake all the spinlocks in the path. You can safely use NULL | |
83 | * for held | |
b4ce94de | 84 | */ |
4008c04a | 85 | noinline void btrfs_clear_path_blocking(struct btrfs_path *p, |
bd681513 | 86 | struct extent_buffer *held, int held_rw) |
b4ce94de CM |
87 | { |
88 | int i; | |
4008c04a CM |
89 | |
90 | #ifdef CONFIG_DEBUG_LOCK_ALLOC | |
91 | /* lockdep really cares that we take all of these spinlocks | |
92 | * in the right order. If any of the locks in the path are not | |
93 | * currently blocking, it is going to complain. So, make really | |
94 | * really sure by forcing the path to blocking before we clear | |
95 | * the path blocking. | |
96 | */ | |
bd681513 CM |
97 | if (held) { |
98 | btrfs_set_lock_blocking_rw(held, held_rw); | |
99 | if (held_rw == BTRFS_WRITE_LOCK) | |
100 | held_rw = BTRFS_WRITE_LOCK_BLOCKING; | |
101 | else if (held_rw == BTRFS_READ_LOCK) | |
102 | held_rw = BTRFS_READ_LOCK_BLOCKING; | |
103 | } | |
4008c04a CM |
104 | btrfs_set_path_blocking(p); |
105 | #endif | |
106 | ||
107 | for (i = BTRFS_MAX_LEVEL - 1; i >= 0; i--) { | |
bd681513 CM |
108 | if (p->nodes[i] && p->locks[i]) { |
109 | btrfs_clear_lock_blocking_rw(p->nodes[i], p->locks[i]); | |
110 | if (p->locks[i] == BTRFS_WRITE_LOCK_BLOCKING) | |
111 | p->locks[i] = BTRFS_WRITE_LOCK; | |
112 | else if (p->locks[i] == BTRFS_READ_LOCK_BLOCKING) | |
113 | p->locks[i] = BTRFS_READ_LOCK; | |
114 | } | |
b4ce94de | 115 | } |
4008c04a CM |
116 | |
117 | #ifdef CONFIG_DEBUG_LOCK_ALLOC | |
118 | if (held) | |
bd681513 | 119 | btrfs_clear_lock_blocking_rw(held, held_rw); |
4008c04a | 120 | #endif |
b4ce94de CM |
121 | } |
122 | ||
d352ac68 | 123 | /* this also releases the path */ |
df24a2b9 | 124 | void btrfs_free_path(struct btrfs_path *p) |
be0e5c09 | 125 | { |
ff175d57 JJ |
126 | if (!p) |
127 | return; | |
b3b4aa74 | 128 | btrfs_release_path(p); |
df24a2b9 | 129 | kmem_cache_free(btrfs_path_cachep, p); |
be0e5c09 CM |
130 | } |
131 | ||
d352ac68 CM |
132 | /* |
133 | * path release drops references on the extent buffers in the path | |
134 | * and it drops any locks held by this path | |
135 | * | |
136 | * It is safe to call this on paths that no locks or extent buffers held. | |
137 | */ | |
b3b4aa74 | 138 | noinline void btrfs_release_path(struct btrfs_path *p) |
eb60ceac CM |
139 | { |
140 | int i; | |
a2135011 | 141 | |
234b63a0 | 142 | for (i = 0; i < BTRFS_MAX_LEVEL; i++) { |
3f157a2f | 143 | p->slots[i] = 0; |
eb60ceac | 144 | if (!p->nodes[i]) |
925baedd CM |
145 | continue; |
146 | if (p->locks[i]) { | |
bd681513 | 147 | btrfs_tree_unlock_rw(p->nodes[i], p->locks[i]); |
925baedd CM |
148 | p->locks[i] = 0; |
149 | } | |
5f39d397 | 150 | free_extent_buffer(p->nodes[i]); |
3f157a2f | 151 | p->nodes[i] = NULL; |
eb60ceac CM |
152 | } |
153 | } | |
154 | ||
d352ac68 CM |
155 | /* |
156 | * safely gets a reference on the root node of a tree. A lock | |
157 | * is not taken, so a concurrent writer may put a different node | |
158 | * at the root of the tree. See btrfs_lock_root_node for the | |
159 | * looping required. | |
160 | * | |
161 | * The extent buffer returned by this has a reference taken, so | |
162 | * it won't disappear. It may stop being the root of the tree | |
163 | * at any time because there are no locks held. | |
164 | */ | |
925baedd CM |
165 | struct extent_buffer *btrfs_root_node(struct btrfs_root *root) |
166 | { | |
167 | struct extent_buffer *eb; | |
240f62c8 | 168 | |
3083ee2e JB |
169 | while (1) { |
170 | rcu_read_lock(); | |
171 | eb = rcu_dereference(root->node); | |
172 | ||
173 | /* | |
174 | * RCU really hurts here, we could free up the root node because | |
175 | * it was cow'ed but we may not get the new root node yet so do | |
176 | * the inc_not_zero dance and if it doesn't work then | |
177 | * synchronize_rcu and try again. | |
178 | */ | |
179 | if (atomic_inc_not_zero(&eb->refs)) { | |
180 | rcu_read_unlock(); | |
181 | break; | |
182 | } | |
183 | rcu_read_unlock(); | |
184 | synchronize_rcu(); | |
185 | } | |
925baedd CM |
186 | return eb; |
187 | } | |
188 | ||
d352ac68 CM |
189 | /* loop around taking references on and locking the root node of the |
190 | * tree until you end up with a lock on the root. A locked buffer | |
191 | * is returned, with a reference held. | |
192 | */ | |
925baedd CM |
193 | struct extent_buffer *btrfs_lock_root_node(struct btrfs_root *root) |
194 | { | |
195 | struct extent_buffer *eb; | |
196 | ||
d397712b | 197 | while (1) { |
925baedd CM |
198 | eb = btrfs_root_node(root); |
199 | btrfs_tree_lock(eb); | |
240f62c8 | 200 | if (eb == root->node) |
925baedd | 201 | break; |
925baedd CM |
202 | btrfs_tree_unlock(eb); |
203 | free_extent_buffer(eb); | |
204 | } | |
205 | return eb; | |
206 | } | |
207 | ||
bd681513 CM |
208 | /* loop around taking references on and locking the root node of the |
209 | * tree until you end up with a lock on the root. A locked buffer | |
210 | * is returned, with a reference held. | |
211 | */ | |
212 | struct extent_buffer *btrfs_read_lock_root_node(struct btrfs_root *root) | |
213 | { | |
214 | struct extent_buffer *eb; | |
215 | ||
216 | while (1) { | |
217 | eb = btrfs_root_node(root); | |
218 | btrfs_tree_read_lock(eb); | |
219 | if (eb == root->node) | |
220 | break; | |
221 | btrfs_tree_read_unlock(eb); | |
222 | free_extent_buffer(eb); | |
223 | } | |
224 | return eb; | |
225 | } | |
226 | ||
d352ac68 CM |
227 | /* cowonly root (everything not a reference counted cow subvolume), just get |
228 | * put onto a simple dirty list. transaction.c walks this to make sure they | |
229 | * get properly updated on disk. | |
230 | */ | |
0b86a832 CM |
231 | static void add_root_to_dirty_list(struct btrfs_root *root) |
232 | { | |
e5846fc6 | 233 | spin_lock(&root->fs_info->trans_lock); |
0b86a832 CM |
234 | if (root->track_dirty && list_empty(&root->dirty_list)) { |
235 | list_add(&root->dirty_list, | |
236 | &root->fs_info->dirty_cowonly_roots); | |
237 | } | |
e5846fc6 | 238 | spin_unlock(&root->fs_info->trans_lock); |
0b86a832 CM |
239 | } |
240 | ||
d352ac68 CM |
241 | /* |
242 | * used by snapshot creation to make a copy of a root for a tree with | |
243 | * a given objectid. The buffer with the new root node is returned in | |
244 | * cow_ret, and this func returns zero on success or a negative error code. | |
245 | */ | |
be20aa9d CM |
246 | int btrfs_copy_root(struct btrfs_trans_handle *trans, |
247 | struct btrfs_root *root, | |
248 | struct extent_buffer *buf, | |
249 | struct extent_buffer **cow_ret, u64 new_root_objectid) | |
250 | { | |
251 | struct extent_buffer *cow; | |
be20aa9d CM |
252 | int ret = 0; |
253 | int level; | |
5d4f98a2 | 254 | struct btrfs_disk_key disk_key; |
be20aa9d CM |
255 | |
256 | WARN_ON(root->ref_cows && trans->transid != | |
257 | root->fs_info->running_transaction->transid); | |
258 | WARN_ON(root->ref_cows && trans->transid != root->last_trans); | |
259 | ||
260 | level = btrfs_header_level(buf); | |
5d4f98a2 YZ |
261 | if (level == 0) |
262 | btrfs_item_key(buf, &disk_key, 0); | |
263 | else | |
264 | btrfs_node_key(buf, &disk_key, 0); | |
31840ae1 | 265 | |
5d4f98a2 YZ |
266 | cow = btrfs_alloc_free_block(trans, root, buf->len, 0, |
267 | new_root_objectid, &disk_key, level, | |
5581a51a | 268 | buf->start, 0); |
5d4f98a2 | 269 | if (IS_ERR(cow)) |
be20aa9d CM |
270 | return PTR_ERR(cow); |
271 | ||
272 | copy_extent_buffer(cow, buf, 0, 0, cow->len); | |
273 | btrfs_set_header_bytenr(cow, cow->start); | |
274 | btrfs_set_header_generation(cow, trans->transid); | |
5d4f98a2 YZ |
275 | btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV); |
276 | btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN | | |
277 | BTRFS_HEADER_FLAG_RELOC); | |
278 | if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID) | |
279 | btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC); | |
280 | else | |
281 | btrfs_set_header_owner(cow, new_root_objectid); | |
be20aa9d | 282 | |
2b82032c YZ |
283 | write_extent_buffer(cow, root->fs_info->fsid, |
284 | (unsigned long)btrfs_header_fsid(cow), | |
285 | BTRFS_FSID_SIZE); | |
286 | ||
be20aa9d | 287 | WARN_ON(btrfs_header_generation(buf) > trans->transid); |
5d4f98a2 | 288 | if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID) |
66d7e7f0 | 289 | ret = btrfs_inc_ref(trans, root, cow, 1, 1); |
5d4f98a2 | 290 | else |
66d7e7f0 | 291 | ret = btrfs_inc_ref(trans, root, cow, 0, 1); |
4aec2b52 | 292 | |
be20aa9d CM |
293 | if (ret) |
294 | return ret; | |
295 | ||
296 | btrfs_mark_buffer_dirty(cow); | |
297 | *cow_ret = cow; | |
298 | return 0; | |
299 | } | |
300 | ||
bd989ba3 JS |
301 | enum mod_log_op { |
302 | MOD_LOG_KEY_REPLACE, | |
303 | MOD_LOG_KEY_ADD, | |
304 | MOD_LOG_KEY_REMOVE, | |
305 | MOD_LOG_KEY_REMOVE_WHILE_FREEING, | |
306 | MOD_LOG_KEY_REMOVE_WHILE_MOVING, | |
307 | MOD_LOG_MOVE_KEYS, | |
308 | MOD_LOG_ROOT_REPLACE, | |
309 | }; | |
310 | ||
311 | struct tree_mod_move { | |
312 | int dst_slot; | |
313 | int nr_items; | |
314 | }; | |
315 | ||
316 | struct tree_mod_root { | |
317 | u64 logical; | |
318 | u8 level; | |
319 | }; | |
320 | ||
321 | struct tree_mod_elem { | |
322 | struct rb_node node; | |
323 | u64 index; /* shifted logical */ | |
324 | struct seq_list elem; | |
325 | enum mod_log_op op; | |
326 | ||
327 | /* this is used for MOD_LOG_KEY_* and MOD_LOG_MOVE_KEYS operations */ | |
328 | int slot; | |
329 | ||
330 | /* this is used for MOD_LOG_KEY* and MOD_LOG_ROOT_REPLACE */ | |
331 | u64 generation; | |
332 | ||
333 | /* those are used for op == MOD_LOG_KEY_{REPLACE,REMOVE} */ | |
334 | struct btrfs_disk_key key; | |
335 | u64 blockptr; | |
336 | ||
337 | /* this is used for op == MOD_LOG_MOVE_KEYS */ | |
338 | struct tree_mod_move move; | |
339 | ||
340 | /* this is used for op == MOD_LOG_ROOT_REPLACE */ | |
341 | struct tree_mod_root old_root; | |
342 | }; | |
343 | ||
344 | static inline void | |
345 | __get_tree_mod_seq(struct btrfs_fs_info *fs_info, struct seq_list *elem) | |
346 | { | |
347 | elem->seq = atomic_inc_return(&fs_info->tree_mod_seq); | |
348 | list_add_tail(&elem->list, &fs_info->tree_mod_seq_list); | |
349 | } | |
350 | ||
351 | void btrfs_get_tree_mod_seq(struct btrfs_fs_info *fs_info, | |
352 | struct seq_list *elem) | |
353 | { | |
354 | elem->flags = 1; | |
355 | spin_lock(&fs_info->tree_mod_seq_lock); | |
356 | __get_tree_mod_seq(fs_info, elem); | |
357 | spin_unlock(&fs_info->tree_mod_seq_lock); | |
358 | } | |
359 | ||
360 | void btrfs_put_tree_mod_seq(struct btrfs_fs_info *fs_info, | |
361 | struct seq_list *elem) | |
362 | { | |
363 | struct rb_root *tm_root; | |
364 | struct rb_node *node; | |
365 | struct rb_node *next; | |
366 | struct seq_list *cur_elem; | |
367 | struct tree_mod_elem *tm; | |
368 | u64 min_seq = (u64)-1; | |
369 | u64 seq_putting = elem->seq; | |
370 | ||
371 | if (!seq_putting) | |
372 | return; | |
373 | ||
374 | BUG_ON(!(elem->flags & 1)); | |
375 | spin_lock(&fs_info->tree_mod_seq_lock); | |
376 | list_del(&elem->list); | |
377 | ||
378 | list_for_each_entry(cur_elem, &fs_info->tree_mod_seq_list, list) { | |
379 | if ((cur_elem->flags & 1) && cur_elem->seq < min_seq) { | |
380 | if (seq_putting > cur_elem->seq) { | |
381 | /* | |
382 | * blocker with lower sequence number exists, we | |
383 | * cannot remove anything from the log | |
384 | */ | |
385 | goto out; | |
386 | } | |
387 | min_seq = cur_elem->seq; | |
388 | } | |
389 | } | |
390 | ||
391 | /* | |
392 | * anything that's lower than the lowest existing (read: blocked) | |
393 | * sequence number can be removed from the tree. | |
394 | */ | |
395 | write_lock(&fs_info->tree_mod_log_lock); | |
396 | tm_root = &fs_info->tree_mod_log; | |
397 | for (node = rb_first(tm_root); node; node = next) { | |
398 | next = rb_next(node); | |
399 | tm = container_of(node, struct tree_mod_elem, node); | |
400 | if (tm->elem.seq > min_seq) | |
401 | continue; | |
402 | rb_erase(node, tm_root); | |
403 | list_del(&tm->elem.list); | |
404 | kfree(tm); | |
405 | } | |
406 | write_unlock(&fs_info->tree_mod_log_lock); | |
407 | out: | |
408 | spin_unlock(&fs_info->tree_mod_seq_lock); | |
409 | } | |
410 | ||
411 | /* | |
412 | * key order of the log: | |
413 | * index -> sequence | |
414 | * | |
415 | * the index is the shifted logical of the *new* root node for root replace | |
416 | * operations, or the shifted logical of the affected block for all other | |
417 | * operations. | |
418 | */ | |
419 | static noinline int | |
420 | __tree_mod_log_insert(struct btrfs_fs_info *fs_info, struct tree_mod_elem *tm) | |
421 | { | |
422 | struct rb_root *tm_root; | |
423 | struct rb_node **new; | |
424 | struct rb_node *parent = NULL; | |
425 | struct tree_mod_elem *cur; | |
426 | int ret = 0; | |
427 | ||
428 | BUG_ON(!tm || !tm->elem.seq); | |
429 | ||
430 | write_lock(&fs_info->tree_mod_log_lock); | |
431 | tm_root = &fs_info->tree_mod_log; | |
432 | new = &tm_root->rb_node; | |
433 | while (*new) { | |
434 | cur = container_of(*new, struct tree_mod_elem, node); | |
435 | parent = *new; | |
436 | if (cur->index < tm->index) | |
437 | new = &((*new)->rb_left); | |
438 | else if (cur->index > tm->index) | |
439 | new = &((*new)->rb_right); | |
440 | else if (cur->elem.seq < tm->elem.seq) | |
441 | new = &((*new)->rb_left); | |
442 | else if (cur->elem.seq > tm->elem.seq) | |
443 | new = &((*new)->rb_right); | |
444 | else { | |
445 | kfree(tm); | |
446 | ret = -EEXIST; | |
447 | goto unlock; | |
448 | } | |
449 | } | |
450 | ||
451 | rb_link_node(&tm->node, parent, new); | |
452 | rb_insert_color(&tm->node, tm_root); | |
453 | unlock: | |
454 | write_unlock(&fs_info->tree_mod_log_lock); | |
455 | return ret; | |
456 | } | |
457 | ||
926dd8a6 JS |
458 | static inline int tree_mod_alloc(struct btrfs_fs_info *fs_info, gfp_t flags, |
459 | struct tree_mod_elem **tm_ret) | |
bd989ba3 JS |
460 | { |
461 | struct tree_mod_elem *tm; | |
926dd8a6 | 462 | int seq; |
bd989ba3 JS |
463 | |
464 | smp_mb(); | |
465 | if (list_empty(&fs_info->tree_mod_seq_list)) | |
466 | return 0; | |
467 | ||
468 | tm = *tm_ret = kzalloc(sizeof(*tm), flags); | |
469 | if (!tm) | |
470 | return -ENOMEM; | |
471 | ||
bd989ba3 | 472 | tm->elem.flags = 0; |
926dd8a6 JS |
473 | spin_lock(&fs_info->tree_mod_seq_lock); |
474 | if (list_empty(&fs_info->tree_mod_seq_list)) { | |
475 | /* | |
476 | * someone emptied the list while we were waiting for the lock. | |
477 | * we must not add to the list, because no blocker exists. items | |
478 | * are removed from the list only when the existing blocker is | |
479 | * removed from the list. | |
480 | */ | |
481 | kfree(tm); | |
482 | seq = 0; | |
483 | } else { | |
484 | __get_tree_mod_seq(fs_info, &tm->elem); | |
485 | seq = tm->elem.seq; | |
486 | } | |
487 | spin_unlock(&fs_info->tree_mod_seq_lock); | |
bd989ba3 JS |
488 | |
489 | return seq; | |
490 | } | |
491 | ||
492 | static noinline int | |
493 | tree_mod_log_insert_key_mask(struct btrfs_fs_info *fs_info, | |
494 | struct extent_buffer *eb, int slot, | |
495 | enum mod_log_op op, gfp_t flags) | |
496 | { | |
497 | struct tree_mod_elem *tm; | |
498 | int ret; | |
499 | ||
500 | ret = tree_mod_alloc(fs_info, flags, &tm); | |
501 | if (ret <= 0) | |
502 | return ret; | |
503 | ||
504 | tm->index = eb->start >> PAGE_CACHE_SHIFT; | |
505 | if (op != MOD_LOG_KEY_ADD) { | |
506 | btrfs_node_key(eb, &tm->key, slot); | |
507 | tm->blockptr = btrfs_node_blockptr(eb, slot); | |
508 | } | |
509 | tm->op = op; | |
510 | tm->slot = slot; | |
511 | tm->generation = btrfs_node_ptr_generation(eb, slot); | |
512 | ||
513 | return __tree_mod_log_insert(fs_info, tm); | |
514 | } | |
515 | ||
516 | static noinline int | |
517 | tree_mod_log_insert_key(struct btrfs_fs_info *fs_info, struct extent_buffer *eb, | |
518 | int slot, enum mod_log_op op) | |
519 | { | |
520 | return tree_mod_log_insert_key_mask(fs_info, eb, slot, op, GFP_NOFS); | |
521 | } | |
522 | ||
523 | static noinline int | |
524 | tree_mod_log_insert_move(struct btrfs_fs_info *fs_info, | |
525 | struct extent_buffer *eb, int dst_slot, int src_slot, | |
526 | int nr_items, gfp_t flags) | |
527 | { | |
528 | struct tree_mod_elem *tm; | |
529 | int ret; | |
530 | int i; | |
531 | ||
532 | ret = tree_mod_alloc(fs_info, flags, &tm); | |
533 | if (ret <= 0) | |
534 | return ret; | |
535 | ||
536 | for (i = 0; i + dst_slot < src_slot && i < nr_items; i++) { | |
537 | ret = tree_mod_log_insert_key(fs_info, eb, i + dst_slot, | |
538 | MOD_LOG_KEY_REMOVE_WHILE_MOVING); | |
539 | BUG_ON(ret < 0); | |
540 | } | |
541 | ||
542 | tm->index = eb->start >> PAGE_CACHE_SHIFT; | |
543 | tm->slot = src_slot; | |
544 | tm->move.dst_slot = dst_slot; | |
545 | tm->move.nr_items = nr_items; | |
546 | tm->op = MOD_LOG_MOVE_KEYS; | |
547 | ||
548 | return __tree_mod_log_insert(fs_info, tm); | |
549 | } | |
550 | ||
551 | static noinline int | |
552 | tree_mod_log_insert_root(struct btrfs_fs_info *fs_info, | |
553 | struct extent_buffer *old_root, | |
554 | struct extent_buffer *new_root, gfp_t flags) | |
555 | { | |
556 | struct tree_mod_elem *tm; | |
557 | int ret; | |
558 | ||
559 | ret = tree_mod_alloc(fs_info, flags, &tm); | |
560 | if (ret <= 0) | |
561 | return ret; | |
562 | ||
563 | tm->index = new_root->start >> PAGE_CACHE_SHIFT; | |
564 | tm->old_root.logical = old_root->start; | |
565 | tm->old_root.level = btrfs_header_level(old_root); | |
566 | tm->generation = btrfs_header_generation(old_root); | |
567 | tm->op = MOD_LOG_ROOT_REPLACE; | |
568 | ||
569 | return __tree_mod_log_insert(fs_info, tm); | |
570 | } | |
571 | ||
572 | static struct tree_mod_elem * | |
573 | __tree_mod_log_search(struct btrfs_fs_info *fs_info, u64 start, u64 min_seq, | |
574 | int smallest) | |
575 | { | |
576 | struct rb_root *tm_root; | |
577 | struct rb_node *node; | |
578 | struct tree_mod_elem *cur = NULL; | |
579 | struct tree_mod_elem *found = NULL; | |
580 | u64 index = start >> PAGE_CACHE_SHIFT; | |
581 | ||
582 | read_lock(&fs_info->tree_mod_log_lock); | |
583 | tm_root = &fs_info->tree_mod_log; | |
584 | node = tm_root->rb_node; | |
585 | while (node) { | |
586 | cur = container_of(node, struct tree_mod_elem, node); | |
587 | if (cur->index < index) { | |
588 | node = node->rb_left; | |
589 | } else if (cur->index > index) { | |
590 | node = node->rb_right; | |
591 | } else if (cur->elem.seq < min_seq) { | |
592 | node = node->rb_left; | |
593 | } else if (!smallest) { | |
594 | /* we want the node with the highest seq */ | |
595 | if (found) | |
596 | BUG_ON(found->elem.seq > cur->elem.seq); | |
597 | found = cur; | |
598 | node = node->rb_left; | |
599 | } else if (cur->elem.seq > min_seq) { | |
600 | /* we want the node with the smallest seq */ | |
601 | if (found) | |
602 | BUG_ON(found->elem.seq < cur->elem.seq); | |
603 | found = cur; | |
604 | node = node->rb_right; | |
605 | } else { | |
606 | found = cur; | |
607 | break; | |
608 | } | |
609 | } | |
610 | read_unlock(&fs_info->tree_mod_log_lock); | |
611 | ||
612 | return found; | |
613 | } | |
614 | ||
615 | /* | |
616 | * this returns the element from the log with the smallest time sequence | |
617 | * value that's in the log (the oldest log item). any element with a time | |
618 | * sequence lower than min_seq will be ignored. | |
619 | */ | |
620 | static struct tree_mod_elem * | |
621 | tree_mod_log_search_oldest(struct btrfs_fs_info *fs_info, u64 start, | |
622 | u64 min_seq) | |
623 | { | |
624 | return __tree_mod_log_search(fs_info, start, min_seq, 1); | |
625 | } | |
626 | ||
627 | /* | |
628 | * this returns the element from the log with the largest time sequence | |
629 | * value that's in the log (the most recent log item). any element with | |
630 | * a time sequence lower than min_seq will be ignored. | |
631 | */ | |
632 | static struct tree_mod_elem * | |
633 | tree_mod_log_search(struct btrfs_fs_info *fs_info, u64 start, u64 min_seq) | |
634 | { | |
635 | return __tree_mod_log_search(fs_info, start, min_seq, 0); | |
636 | } | |
637 | ||
638 | static inline void | |
639 | tree_mod_log_eb_copy(struct btrfs_fs_info *fs_info, struct extent_buffer *dst, | |
640 | struct extent_buffer *src, unsigned long dst_offset, | |
641 | unsigned long src_offset, int nr_items) | |
642 | { | |
643 | int ret; | |
644 | int i; | |
645 | ||
646 | smp_mb(); | |
647 | if (list_empty(&fs_info->tree_mod_seq_list)) | |
648 | return; | |
649 | ||
650 | if (btrfs_header_level(dst) == 0 && btrfs_header_level(src) == 0) | |
651 | return; | |
652 | ||
653 | /* speed this up by single seq for all operations? */ | |
654 | for (i = 0; i < nr_items; i++) { | |
655 | ret = tree_mod_log_insert_key(fs_info, src, i + src_offset, | |
656 | MOD_LOG_KEY_REMOVE); | |
657 | BUG_ON(ret < 0); | |
658 | ret = tree_mod_log_insert_key(fs_info, dst, i + dst_offset, | |
659 | MOD_LOG_KEY_ADD); | |
660 | BUG_ON(ret < 0); | |
661 | } | |
662 | } | |
663 | ||
664 | static inline void | |
665 | tree_mod_log_eb_move(struct btrfs_fs_info *fs_info, struct extent_buffer *dst, | |
666 | int dst_offset, int src_offset, int nr_items) | |
667 | { | |
668 | int ret; | |
669 | ret = tree_mod_log_insert_move(fs_info, dst, dst_offset, src_offset, | |
670 | nr_items, GFP_NOFS); | |
671 | BUG_ON(ret < 0); | |
672 | } | |
673 | ||
674 | static inline void | |
675 | tree_mod_log_set_node_key(struct btrfs_fs_info *fs_info, | |
676 | struct extent_buffer *eb, | |
677 | struct btrfs_disk_key *disk_key, int slot, int atomic) | |
678 | { | |
679 | int ret; | |
680 | ||
681 | ret = tree_mod_log_insert_key_mask(fs_info, eb, slot, | |
682 | MOD_LOG_KEY_REPLACE, | |
683 | atomic ? GFP_ATOMIC : GFP_NOFS); | |
684 | BUG_ON(ret < 0); | |
685 | } | |
686 | ||
687 | static void tree_mod_log_free_eb(struct btrfs_fs_info *fs_info, | |
688 | struct extent_buffer *eb) | |
689 | { | |
690 | int i; | |
691 | int ret; | |
692 | u32 nritems; | |
693 | ||
694 | smp_mb(); | |
695 | if (list_empty(&fs_info->tree_mod_seq_list)) | |
696 | return; | |
697 | ||
698 | if (btrfs_header_level(eb) == 0) | |
699 | return; | |
700 | ||
701 | nritems = btrfs_header_nritems(eb); | |
702 | for (i = nritems - 1; i >= 0; i--) { | |
703 | ret = tree_mod_log_insert_key(fs_info, eb, i, | |
704 | MOD_LOG_KEY_REMOVE_WHILE_FREEING); | |
705 | BUG_ON(ret < 0); | |
706 | } | |
707 | } | |
708 | ||
709 | static inline void | |
710 | tree_mod_log_set_root_pointer(struct btrfs_root *root, | |
711 | struct extent_buffer *new_root_node) | |
712 | { | |
713 | int ret; | |
714 | tree_mod_log_free_eb(root->fs_info, root->node); | |
715 | ret = tree_mod_log_insert_root(root->fs_info, root->node, | |
716 | new_root_node, GFP_NOFS); | |
717 | BUG_ON(ret < 0); | |
718 | } | |
719 | ||
5d4f98a2 YZ |
720 | /* |
721 | * check if the tree block can be shared by multiple trees | |
722 | */ | |
723 | int btrfs_block_can_be_shared(struct btrfs_root *root, | |
724 | struct extent_buffer *buf) | |
725 | { | |
726 | /* | |
727 | * Tree blocks not in refernece counted trees and tree roots | |
728 | * are never shared. If a block was allocated after the last | |
729 | * snapshot and the block was not allocated by tree relocation, | |
730 | * we know the block is not shared. | |
731 | */ | |
732 | if (root->ref_cows && | |
733 | buf != root->node && buf != root->commit_root && | |
734 | (btrfs_header_generation(buf) <= | |
735 | btrfs_root_last_snapshot(&root->root_item) || | |
736 | btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC))) | |
737 | return 1; | |
738 | #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 | |
739 | if (root->ref_cows && | |
740 | btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) | |
741 | return 1; | |
742 | #endif | |
743 | return 0; | |
744 | } | |
745 | ||
746 | static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans, | |
747 | struct btrfs_root *root, | |
748 | struct extent_buffer *buf, | |
f0486c68 YZ |
749 | struct extent_buffer *cow, |
750 | int *last_ref) | |
5d4f98a2 YZ |
751 | { |
752 | u64 refs; | |
753 | u64 owner; | |
754 | u64 flags; | |
755 | u64 new_flags = 0; | |
756 | int ret; | |
757 | ||
758 | /* | |
759 | * Backrefs update rules: | |
760 | * | |
761 | * Always use full backrefs for extent pointers in tree block | |
762 | * allocated by tree relocation. | |
763 | * | |
764 | * If a shared tree block is no longer referenced by its owner | |
765 | * tree (btrfs_header_owner(buf) == root->root_key.objectid), | |
766 | * use full backrefs for extent pointers in tree block. | |
767 | * | |
768 | * If a tree block is been relocating | |
769 | * (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID), | |
770 | * use full backrefs for extent pointers in tree block. | |
771 | * The reason for this is some operations (such as drop tree) | |
772 | * are only allowed for blocks use full backrefs. | |
773 | */ | |
774 | ||
775 | if (btrfs_block_can_be_shared(root, buf)) { | |
776 | ret = btrfs_lookup_extent_info(trans, root, buf->start, | |
777 | buf->len, &refs, &flags); | |
be1a5564 MF |
778 | if (ret) |
779 | return ret; | |
e5df9573 MF |
780 | if (refs == 0) { |
781 | ret = -EROFS; | |
782 | btrfs_std_error(root->fs_info, ret); | |
783 | return ret; | |
784 | } | |
5d4f98a2 YZ |
785 | } else { |
786 | refs = 1; | |
787 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID || | |
788 | btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) | |
789 | flags = BTRFS_BLOCK_FLAG_FULL_BACKREF; | |
790 | else | |
791 | flags = 0; | |
792 | } | |
793 | ||
794 | owner = btrfs_header_owner(buf); | |
795 | BUG_ON(owner == BTRFS_TREE_RELOC_OBJECTID && | |
796 | !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)); | |
797 | ||
798 | if (refs > 1) { | |
799 | if ((owner == root->root_key.objectid || | |
800 | root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) && | |
801 | !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)) { | |
66d7e7f0 | 802 | ret = btrfs_inc_ref(trans, root, buf, 1, 1); |
79787eaa | 803 | BUG_ON(ret); /* -ENOMEM */ |
5d4f98a2 YZ |
804 | |
805 | if (root->root_key.objectid == | |
806 | BTRFS_TREE_RELOC_OBJECTID) { | |
66d7e7f0 | 807 | ret = btrfs_dec_ref(trans, root, buf, 0, 1); |
79787eaa | 808 | BUG_ON(ret); /* -ENOMEM */ |
66d7e7f0 | 809 | ret = btrfs_inc_ref(trans, root, cow, 1, 1); |
79787eaa | 810 | BUG_ON(ret); /* -ENOMEM */ |
5d4f98a2 YZ |
811 | } |
812 | new_flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF; | |
813 | } else { | |
814 | ||
815 | if (root->root_key.objectid == | |
816 | BTRFS_TREE_RELOC_OBJECTID) | |
66d7e7f0 | 817 | ret = btrfs_inc_ref(trans, root, cow, 1, 1); |
5d4f98a2 | 818 | else |
66d7e7f0 | 819 | ret = btrfs_inc_ref(trans, root, cow, 0, 1); |
79787eaa | 820 | BUG_ON(ret); /* -ENOMEM */ |
5d4f98a2 YZ |
821 | } |
822 | if (new_flags != 0) { | |
823 | ret = btrfs_set_disk_extent_flags(trans, root, | |
824 | buf->start, | |
825 | buf->len, | |
826 | new_flags, 0); | |
be1a5564 MF |
827 | if (ret) |
828 | return ret; | |
5d4f98a2 YZ |
829 | } |
830 | } else { | |
831 | if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF) { | |
832 | if (root->root_key.objectid == | |
833 | BTRFS_TREE_RELOC_OBJECTID) | |
66d7e7f0 | 834 | ret = btrfs_inc_ref(trans, root, cow, 1, 1); |
5d4f98a2 | 835 | else |
66d7e7f0 | 836 | ret = btrfs_inc_ref(trans, root, cow, 0, 1); |
79787eaa | 837 | BUG_ON(ret); /* -ENOMEM */ |
66d7e7f0 | 838 | ret = btrfs_dec_ref(trans, root, buf, 1, 1); |
79787eaa | 839 | BUG_ON(ret); /* -ENOMEM */ |
5d4f98a2 | 840 | } |
f230475e JS |
841 | /* |
842 | * don't log freeing in case we're freeing the root node, this | |
843 | * is done by tree_mod_log_set_root_pointer later | |
844 | */ | |
845 | if (buf != root->node && btrfs_header_level(buf) != 0) | |
846 | tree_mod_log_free_eb(root->fs_info, buf); | |
5d4f98a2 | 847 | clean_tree_block(trans, root, buf); |
f0486c68 | 848 | *last_ref = 1; |
5d4f98a2 YZ |
849 | } |
850 | return 0; | |
851 | } | |
852 | ||
d352ac68 | 853 | /* |
d397712b CM |
854 | * does the dirty work in cow of a single block. The parent block (if |
855 | * supplied) is updated to point to the new cow copy. The new buffer is marked | |
856 | * dirty and returned locked. If you modify the block it needs to be marked | |
857 | * dirty again. | |
d352ac68 CM |
858 | * |
859 | * search_start -- an allocation hint for the new block | |
860 | * | |
d397712b CM |
861 | * empty_size -- a hint that you plan on doing more cow. This is the size in |
862 | * bytes the allocator should try to find free next to the block it returns. | |
863 | * This is just a hint and may be ignored by the allocator. | |
d352ac68 | 864 | */ |
d397712b | 865 | static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans, |
5f39d397 CM |
866 | struct btrfs_root *root, |
867 | struct extent_buffer *buf, | |
868 | struct extent_buffer *parent, int parent_slot, | |
869 | struct extent_buffer **cow_ret, | |
9fa8cfe7 | 870 | u64 search_start, u64 empty_size) |
02217ed2 | 871 | { |
5d4f98a2 | 872 | struct btrfs_disk_key disk_key; |
5f39d397 | 873 | struct extent_buffer *cow; |
be1a5564 | 874 | int level, ret; |
f0486c68 | 875 | int last_ref = 0; |
925baedd | 876 | int unlock_orig = 0; |
5d4f98a2 | 877 | u64 parent_start; |
7bb86316 | 878 | |
925baedd CM |
879 | if (*cow_ret == buf) |
880 | unlock_orig = 1; | |
881 | ||
b9447ef8 | 882 | btrfs_assert_tree_locked(buf); |
925baedd | 883 | |
7bb86316 CM |
884 | WARN_ON(root->ref_cows && trans->transid != |
885 | root->fs_info->running_transaction->transid); | |
6702ed49 | 886 | WARN_ON(root->ref_cows && trans->transid != root->last_trans); |
5f39d397 | 887 | |
7bb86316 | 888 | level = btrfs_header_level(buf); |
31840ae1 | 889 | |
5d4f98a2 YZ |
890 | if (level == 0) |
891 | btrfs_item_key(buf, &disk_key, 0); | |
892 | else | |
893 | btrfs_node_key(buf, &disk_key, 0); | |
894 | ||
895 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) { | |
896 | if (parent) | |
897 | parent_start = parent->start; | |
898 | else | |
899 | parent_start = 0; | |
900 | } else | |
901 | parent_start = 0; | |
902 | ||
903 | cow = btrfs_alloc_free_block(trans, root, buf->len, parent_start, | |
904 | root->root_key.objectid, &disk_key, | |
5581a51a | 905 | level, search_start, empty_size); |
54aa1f4d CM |
906 | if (IS_ERR(cow)) |
907 | return PTR_ERR(cow); | |
6702ed49 | 908 | |
b4ce94de CM |
909 | /* cow is set to blocking by btrfs_init_new_buffer */ |
910 | ||
5f39d397 | 911 | copy_extent_buffer(cow, buf, 0, 0, cow->len); |
db94535d | 912 | btrfs_set_header_bytenr(cow, cow->start); |
5f39d397 | 913 | btrfs_set_header_generation(cow, trans->transid); |
5d4f98a2 YZ |
914 | btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV); |
915 | btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN | | |
916 | BTRFS_HEADER_FLAG_RELOC); | |
917 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) | |
918 | btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC); | |
919 | else | |
920 | btrfs_set_header_owner(cow, root->root_key.objectid); | |
6702ed49 | 921 | |
2b82032c YZ |
922 | write_extent_buffer(cow, root->fs_info->fsid, |
923 | (unsigned long)btrfs_header_fsid(cow), | |
924 | BTRFS_FSID_SIZE); | |
925 | ||
be1a5564 | 926 | ret = update_ref_for_cow(trans, root, buf, cow, &last_ref); |
b68dc2a9 | 927 | if (ret) { |
79787eaa | 928 | btrfs_abort_transaction(trans, root, ret); |
b68dc2a9 MF |
929 | return ret; |
930 | } | |
1a40e23b | 931 | |
3fd0a558 YZ |
932 | if (root->ref_cows) |
933 | btrfs_reloc_cow_block(trans, root, buf, cow); | |
934 | ||
02217ed2 | 935 | if (buf == root->node) { |
925baedd | 936 | WARN_ON(parent && parent != buf); |
5d4f98a2 YZ |
937 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID || |
938 | btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) | |
939 | parent_start = buf->start; | |
940 | else | |
941 | parent_start = 0; | |
925baedd | 942 | |
5f39d397 | 943 | extent_buffer_get(cow); |
f230475e | 944 | tree_mod_log_set_root_pointer(root, cow); |
240f62c8 | 945 | rcu_assign_pointer(root->node, cow); |
925baedd | 946 | |
f0486c68 | 947 | btrfs_free_tree_block(trans, root, buf, parent_start, |
5581a51a | 948 | last_ref); |
5f39d397 | 949 | free_extent_buffer(buf); |
0b86a832 | 950 | add_root_to_dirty_list(root); |
02217ed2 | 951 | } else { |
5d4f98a2 YZ |
952 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) |
953 | parent_start = parent->start; | |
954 | else | |
955 | parent_start = 0; | |
956 | ||
957 | WARN_ON(trans->transid != btrfs_header_generation(parent)); | |
f230475e JS |
958 | tree_mod_log_insert_key(root->fs_info, parent, parent_slot, |
959 | MOD_LOG_KEY_REPLACE); | |
5f39d397 | 960 | btrfs_set_node_blockptr(parent, parent_slot, |
db94535d | 961 | cow->start); |
74493f7a CM |
962 | btrfs_set_node_ptr_generation(parent, parent_slot, |
963 | trans->transid); | |
d6025579 | 964 | btrfs_mark_buffer_dirty(parent); |
f0486c68 | 965 | btrfs_free_tree_block(trans, root, buf, parent_start, |
5581a51a | 966 | last_ref); |
02217ed2 | 967 | } |
925baedd CM |
968 | if (unlock_orig) |
969 | btrfs_tree_unlock(buf); | |
3083ee2e | 970 | free_extent_buffer_stale(buf); |
ccd467d6 | 971 | btrfs_mark_buffer_dirty(cow); |
2c90e5d6 | 972 | *cow_ret = cow; |
02217ed2 CM |
973 | return 0; |
974 | } | |
975 | ||
5d9e75c4 JS |
976 | /* |
977 | * returns the logical address of the oldest predecessor of the given root. | |
978 | * entries older than time_seq are ignored. | |
979 | */ | |
980 | static struct tree_mod_elem * | |
981 | __tree_mod_log_oldest_root(struct btrfs_fs_info *fs_info, | |
982 | struct btrfs_root *root, u64 time_seq) | |
983 | { | |
984 | struct tree_mod_elem *tm; | |
985 | struct tree_mod_elem *found = NULL; | |
986 | u64 root_logical = root->node->start; | |
987 | int looped = 0; | |
988 | ||
989 | if (!time_seq) | |
990 | return 0; | |
991 | ||
992 | /* | |
993 | * the very last operation that's logged for a root is the replacement | |
994 | * operation (if it is replaced at all). this has the index of the *new* | |
995 | * root, making it the very first operation that's logged for this root. | |
996 | */ | |
997 | while (1) { | |
998 | tm = tree_mod_log_search_oldest(fs_info, root_logical, | |
999 | time_seq); | |
1000 | if (!looped && !tm) | |
1001 | return 0; | |
1002 | /* | |
1003 | * we must have key remove operations in the log before the | |
1004 | * replace operation. | |
1005 | */ | |
1006 | BUG_ON(!tm); | |
1007 | ||
1008 | if (tm->op != MOD_LOG_ROOT_REPLACE) | |
1009 | break; | |
1010 | ||
1011 | found = tm; | |
1012 | root_logical = tm->old_root.logical; | |
1013 | BUG_ON(root_logical == root->node->start); | |
1014 | looped = 1; | |
1015 | } | |
1016 | ||
1017 | return found; | |
1018 | } | |
1019 | ||
1020 | /* | |
1021 | * tm is a pointer to the first operation to rewind within eb. then, all | |
1022 | * previous operations will be rewinded (until we reach something older than | |
1023 | * time_seq). | |
1024 | */ | |
1025 | static void | |
1026 | __tree_mod_log_rewind(struct extent_buffer *eb, u64 time_seq, | |
1027 | struct tree_mod_elem *first_tm) | |
1028 | { | |
1029 | u32 n; | |
1030 | struct rb_node *next; | |
1031 | struct tree_mod_elem *tm = first_tm; | |
1032 | unsigned long o_dst; | |
1033 | unsigned long o_src; | |
1034 | unsigned long p_size = sizeof(struct btrfs_key_ptr); | |
1035 | ||
1036 | n = btrfs_header_nritems(eb); | |
1037 | while (tm && tm->elem.seq >= time_seq) { | |
1038 | /* | |
1039 | * all the operations are recorded with the operator used for | |
1040 | * the modification. as we're going backwards, we do the | |
1041 | * opposite of each operation here. | |
1042 | */ | |
1043 | switch (tm->op) { | |
1044 | case MOD_LOG_KEY_REMOVE_WHILE_FREEING: | |
1045 | BUG_ON(tm->slot < n); | |
1046 | case MOD_LOG_KEY_REMOVE_WHILE_MOVING: | |
1047 | case MOD_LOG_KEY_REMOVE: | |
1048 | btrfs_set_node_key(eb, &tm->key, tm->slot); | |
1049 | btrfs_set_node_blockptr(eb, tm->slot, tm->blockptr); | |
1050 | btrfs_set_node_ptr_generation(eb, tm->slot, | |
1051 | tm->generation); | |
1052 | n++; | |
1053 | break; | |
1054 | case MOD_LOG_KEY_REPLACE: | |
1055 | BUG_ON(tm->slot >= n); | |
1056 | btrfs_set_node_key(eb, &tm->key, tm->slot); | |
1057 | btrfs_set_node_blockptr(eb, tm->slot, tm->blockptr); | |
1058 | btrfs_set_node_ptr_generation(eb, tm->slot, | |
1059 | tm->generation); | |
1060 | break; | |
1061 | case MOD_LOG_KEY_ADD: | |
1062 | if (tm->slot != n - 1) { | |
1063 | o_dst = btrfs_node_key_ptr_offset(tm->slot); | |
1064 | o_src = btrfs_node_key_ptr_offset(tm->slot + 1); | |
1065 | memmove_extent_buffer(eb, o_dst, o_src, p_size); | |
1066 | } | |
1067 | n--; | |
1068 | break; | |
1069 | case MOD_LOG_MOVE_KEYS: | |
1070 | memmove_extent_buffer(eb, tm->slot, tm->move.dst_slot, | |
1071 | tm->move.nr_items * p_size); | |
1072 | break; | |
1073 | case MOD_LOG_ROOT_REPLACE: | |
1074 | /* | |
1075 | * this operation is special. for roots, this must be | |
1076 | * handled explicitly before rewinding. | |
1077 | * for non-roots, this operation may exist if the node | |
1078 | * was a root: root A -> child B; then A gets empty and | |
1079 | * B is promoted to the new root. in the mod log, we'll | |
1080 | * have a root-replace operation for B, a tree block | |
1081 | * that is no root. we simply ignore that operation. | |
1082 | */ | |
1083 | break; | |
1084 | } | |
1085 | next = rb_next(&tm->node); | |
1086 | if (!next) | |
1087 | break; | |
1088 | tm = container_of(next, struct tree_mod_elem, node); | |
1089 | if (tm->index != first_tm->index) | |
1090 | break; | |
1091 | } | |
1092 | btrfs_set_header_nritems(eb, n); | |
1093 | } | |
1094 | ||
1095 | static struct extent_buffer * | |
1096 | tree_mod_log_rewind(struct btrfs_fs_info *fs_info, struct extent_buffer *eb, | |
1097 | u64 time_seq) | |
1098 | { | |
1099 | struct extent_buffer *eb_rewin; | |
1100 | struct tree_mod_elem *tm; | |
1101 | ||
1102 | if (!time_seq) | |
1103 | return eb; | |
1104 | ||
1105 | if (btrfs_header_level(eb) == 0) | |
1106 | return eb; | |
1107 | ||
1108 | tm = tree_mod_log_search(fs_info, eb->start, time_seq); | |
1109 | if (!tm) | |
1110 | return eb; | |
1111 | ||
1112 | if (tm->op == MOD_LOG_KEY_REMOVE_WHILE_FREEING) { | |
1113 | BUG_ON(tm->slot != 0); | |
1114 | eb_rewin = alloc_dummy_extent_buffer(eb->start, | |
1115 | fs_info->tree_root->nodesize); | |
1116 | BUG_ON(!eb_rewin); | |
1117 | btrfs_set_header_bytenr(eb_rewin, eb->start); | |
1118 | btrfs_set_header_backref_rev(eb_rewin, | |
1119 | btrfs_header_backref_rev(eb)); | |
1120 | btrfs_set_header_owner(eb_rewin, btrfs_header_owner(eb)); | |
1121 | } else { | |
1122 | eb_rewin = btrfs_clone_extent_buffer(eb); | |
1123 | BUG_ON(!eb_rewin); | |
1124 | } | |
1125 | ||
1126 | extent_buffer_get(eb_rewin); | |
1127 | free_extent_buffer(eb); | |
1128 | ||
1129 | __tree_mod_log_rewind(eb_rewin, time_seq, tm); | |
1130 | ||
1131 | return eb_rewin; | |
1132 | } | |
1133 | ||
1134 | static inline struct extent_buffer * | |
1135 | get_old_root(struct btrfs_root *root, u64 time_seq) | |
1136 | { | |
1137 | struct tree_mod_elem *tm; | |
1138 | struct extent_buffer *eb; | |
1139 | struct tree_mod_root *old_root; | |
1140 | u64 old_generation; | |
1141 | ||
1142 | tm = __tree_mod_log_oldest_root(root->fs_info, root, time_seq); | |
1143 | if (!tm) | |
1144 | return root->node; | |
1145 | ||
1146 | old_root = &tm->old_root; | |
1147 | old_generation = tm->generation; | |
1148 | ||
1149 | tm = tree_mod_log_search(root->fs_info, old_root->logical, time_seq); | |
1150 | /* | |
1151 | * there was an item in the log when __tree_mod_log_oldest_root | |
1152 | * returned. this one must not go away, because the time_seq passed to | |
1153 | * us must be blocking its removal. | |
1154 | */ | |
1155 | BUG_ON(!tm); | |
1156 | ||
1157 | if (old_root->logical == root->node->start) { | |
1158 | /* there are logged operations for the current root */ | |
1159 | eb = btrfs_clone_extent_buffer(root->node); | |
1160 | } else { | |
1161 | /* there's a root replace operation for the current root */ | |
1162 | eb = alloc_dummy_extent_buffer(tm->index << PAGE_CACHE_SHIFT, | |
1163 | root->nodesize); | |
1164 | btrfs_set_header_bytenr(eb, eb->start); | |
1165 | btrfs_set_header_backref_rev(eb, BTRFS_MIXED_BACKREF_REV); | |
1166 | btrfs_set_header_owner(eb, root->root_key.objectid); | |
1167 | } | |
1168 | if (!eb) | |
1169 | return NULL; | |
1170 | btrfs_set_header_level(eb, old_root->level); | |
1171 | btrfs_set_header_generation(eb, old_generation); | |
1172 | __tree_mod_log_rewind(eb, time_seq, tm); | |
1173 | ||
1174 | return eb; | |
1175 | } | |
1176 | ||
5d4f98a2 YZ |
1177 | static inline int should_cow_block(struct btrfs_trans_handle *trans, |
1178 | struct btrfs_root *root, | |
1179 | struct extent_buffer *buf) | |
1180 | { | |
f1ebcc74 LB |
1181 | /* ensure we can see the force_cow */ |
1182 | smp_rmb(); | |
1183 | ||
1184 | /* | |
1185 | * We do not need to cow a block if | |
1186 | * 1) this block is not created or changed in this transaction; | |
1187 | * 2) this block does not belong to TREE_RELOC tree; | |
1188 | * 3) the root is not forced COW. | |
1189 | * | |
1190 | * What is forced COW: | |
1191 | * when we create snapshot during commiting the transaction, | |
1192 | * after we've finished coping src root, we must COW the shared | |
1193 | * block to ensure the metadata consistency. | |
1194 | */ | |
5d4f98a2 YZ |
1195 | if (btrfs_header_generation(buf) == trans->transid && |
1196 | !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN) && | |
1197 | !(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID && | |
f1ebcc74 LB |
1198 | btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC)) && |
1199 | !root->force_cow) | |
5d4f98a2 YZ |
1200 | return 0; |
1201 | return 1; | |
1202 | } | |
1203 | ||
d352ac68 CM |
1204 | /* |
1205 | * cows a single block, see __btrfs_cow_block for the real work. | |
1206 | * This version of it has extra checks so that a block isn't cow'd more than | |
1207 | * once per transaction, as long as it hasn't been written yet | |
1208 | */ | |
d397712b | 1209 | noinline int btrfs_cow_block(struct btrfs_trans_handle *trans, |
5f39d397 CM |
1210 | struct btrfs_root *root, struct extent_buffer *buf, |
1211 | struct extent_buffer *parent, int parent_slot, | |
9fa8cfe7 | 1212 | struct extent_buffer **cow_ret) |
6702ed49 CM |
1213 | { |
1214 | u64 search_start; | |
f510cfec | 1215 | int ret; |
dc17ff8f | 1216 | |
6702ed49 | 1217 | if (trans->transaction != root->fs_info->running_transaction) { |
d397712b CM |
1218 | printk(KERN_CRIT "trans %llu running %llu\n", |
1219 | (unsigned long long)trans->transid, | |
1220 | (unsigned long long) | |
6702ed49 CM |
1221 | root->fs_info->running_transaction->transid); |
1222 | WARN_ON(1); | |
1223 | } | |
1224 | if (trans->transid != root->fs_info->generation) { | |
d397712b CM |
1225 | printk(KERN_CRIT "trans %llu running %llu\n", |
1226 | (unsigned long long)trans->transid, | |
1227 | (unsigned long long)root->fs_info->generation); | |
6702ed49 CM |
1228 | WARN_ON(1); |
1229 | } | |
dc17ff8f | 1230 | |
5d4f98a2 | 1231 | if (!should_cow_block(trans, root, buf)) { |
6702ed49 CM |
1232 | *cow_ret = buf; |
1233 | return 0; | |
1234 | } | |
c487685d | 1235 | |
0b86a832 | 1236 | search_start = buf->start & ~((u64)(1024 * 1024 * 1024) - 1); |
b4ce94de CM |
1237 | |
1238 | if (parent) | |
1239 | btrfs_set_lock_blocking(parent); | |
1240 | btrfs_set_lock_blocking(buf); | |
1241 | ||
f510cfec | 1242 | ret = __btrfs_cow_block(trans, root, buf, parent, |
9fa8cfe7 | 1243 | parent_slot, cow_ret, search_start, 0); |
1abe9b8a | 1244 | |
1245 | trace_btrfs_cow_block(root, buf, *cow_ret); | |
1246 | ||
f510cfec | 1247 | return ret; |
6702ed49 CM |
1248 | } |
1249 | ||
d352ac68 CM |
1250 | /* |
1251 | * helper function for defrag to decide if two blocks pointed to by a | |
1252 | * node are actually close by | |
1253 | */ | |
6b80053d | 1254 | static int close_blocks(u64 blocknr, u64 other, u32 blocksize) |
6702ed49 | 1255 | { |
6b80053d | 1256 | if (blocknr < other && other - (blocknr + blocksize) < 32768) |
6702ed49 | 1257 | return 1; |
6b80053d | 1258 | if (blocknr > other && blocknr - (other + blocksize) < 32768) |
6702ed49 CM |
1259 | return 1; |
1260 | return 0; | |
1261 | } | |
1262 | ||
081e9573 CM |
1263 | /* |
1264 | * compare two keys in a memcmp fashion | |
1265 | */ | |
1266 | static int comp_keys(struct btrfs_disk_key *disk, struct btrfs_key *k2) | |
1267 | { | |
1268 | struct btrfs_key k1; | |
1269 | ||
1270 | btrfs_disk_key_to_cpu(&k1, disk); | |
1271 | ||
20736aba | 1272 | return btrfs_comp_cpu_keys(&k1, k2); |
081e9573 CM |
1273 | } |
1274 | ||
f3465ca4 JB |
1275 | /* |
1276 | * same as comp_keys only with two btrfs_key's | |
1277 | */ | |
5d4f98a2 | 1278 | int btrfs_comp_cpu_keys(struct btrfs_key *k1, struct btrfs_key *k2) |
f3465ca4 JB |
1279 | { |
1280 | if (k1->objectid > k2->objectid) | |
1281 | return 1; | |
1282 | if (k1->objectid < k2->objectid) | |
1283 | return -1; | |
1284 | if (k1->type > k2->type) | |
1285 | return 1; | |
1286 | if (k1->type < k2->type) | |
1287 | return -1; | |
1288 | if (k1->offset > k2->offset) | |
1289 | return 1; | |
1290 | if (k1->offset < k2->offset) | |
1291 | return -1; | |
1292 | return 0; | |
1293 | } | |
081e9573 | 1294 | |
d352ac68 CM |
1295 | /* |
1296 | * this is used by the defrag code to go through all the | |
1297 | * leaves pointed to by a node and reallocate them so that | |
1298 | * disk order is close to key order | |
1299 | */ | |
6702ed49 | 1300 | int btrfs_realloc_node(struct btrfs_trans_handle *trans, |
5f39d397 | 1301 | struct btrfs_root *root, struct extent_buffer *parent, |
a6b6e75e CM |
1302 | int start_slot, int cache_only, u64 *last_ret, |
1303 | struct btrfs_key *progress) | |
6702ed49 | 1304 | { |
6b80053d | 1305 | struct extent_buffer *cur; |
6702ed49 | 1306 | u64 blocknr; |
ca7a79ad | 1307 | u64 gen; |
e9d0b13b CM |
1308 | u64 search_start = *last_ret; |
1309 | u64 last_block = 0; | |
6702ed49 CM |
1310 | u64 other; |
1311 | u32 parent_nritems; | |
6702ed49 CM |
1312 | int end_slot; |
1313 | int i; | |
1314 | int err = 0; | |
f2183bde | 1315 | int parent_level; |
6b80053d CM |
1316 | int uptodate; |
1317 | u32 blocksize; | |
081e9573 CM |
1318 | int progress_passed = 0; |
1319 | struct btrfs_disk_key disk_key; | |
6702ed49 | 1320 | |
5708b959 CM |
1321 | parent_level = btrfs_header_level(parent); |
1322 | if (cache_only && parent_level != 1) | |
1323 | return 0; | |
1324 | ||
d397712b | 1325 | if (trans->transaction != root->fs_info->running_transaction) |
6702ed49 | 1326 | WARN_ON(1); |
d397712b | 1327 | if (trans->transid != root->fs_info->generation) |
6702ed49 | 1328 | WARN_ON(1); |
86479a04 | 1329 | |
6b80053d | 1330 | parent_nritems = btrfs_header_nritems(parent); |
6b80053d | 1331 | blocksize = btrfs_level_size(root, parent_level - 1); |
6702ed49 CM |
1332 | end_slot = parent_nritems; |
1333 | ||
1334 | if (parent_nritems == 1) | |
1335 | return 0; | |
1336 | ||
b4ce94de CM |
1337 | btrfs_set_lock_blocking(parent); |
1338 | ||
6702ed49 CM |
1339 | for (i = start_slot; i < end_slot; i++) { |
1340 | int close = 1; | |
a6b6e75e | 1341 | |
081e9573 CM |
1342 | btrfs_node_key(parent, &disk_key, i); |
1343 | if (!progress_passed && comp_keys(&disk_key, progress) < 0) | |
1344 | continue; | |
1345 | ||
1346 | progress_passed = 1; | |
6b80053d | 1347 | blocknr = btrfs_node_blockptr(parent, i); |
ca7a79ad | 1348 | gen = btrfs_node_ptr_generation(parent, i); |
e9d0b13b CM |
1349 | if (last_block == 0) |
1350 | last_block = blocknr; | |
5708b959 | 1351 | |
6702ed49 | 1352 | if (i > 0) { |
6b80053d CM |
1353 | other = btrfs_node_blockptr(parent, i - 1); |
1354 | close = close_blocks(blocknr, other, blocksize); | |
6702ed49 | 1355 | } |
0ef3e66b | 1356 | if (!close && i < end_slot - 2) { |
6b80053d CM |
1357 | other = btrfs_node_blockptr(parent, i + 1); |
1358 | close = close_blocks(blocknr, other, blocksize); | |
6702ed49 | 1359 | } |
e9d0b13b CM |
1360 | if (close) { |
1361 | last_block = blocknr; | |
6702ed49 | 1362 | continue; |
e9d0b13b | 1363 | } |
6702ed49 | 1364 | |
6b80053d CM |
1365 | cur = btrfs_find_tree_block(root, blocknr, blocksize); |
1366 | if (cur) | |
b9fab919 | 1367 | uptodate = btrfs_buffer_uptodate(cur, gen, 0); |
6b80053d CM |
1368 | else |
1369 | uptodate = 0; | |
5708b959 | 1370 | if (!cur || !uptodate) { |
6702ed49 | 1371 | if (cache_only) { |
6b80053d | 1372 | free_extent_buffer(cur); |
6702ed49 CM |
1373 | continue; |
1374 | } | |
6b80053d CM |
1375 | if (!cur) { |
1376 | cur = read_tree_block(root, blocknr, | |
ca7a79ad | 1377 | blocksize, gen); |
97d9a8a4 TI |
1378 | if (!cur) |
1379 | return -EIO; | |
6b80053d | 1380 | } else if (!uptodate) { |
ca7a79ad | 1381 | btrfs_read_buffer(cur, gen); |
f2183bde | 1382 | } |
6702ed49 | 1383 | } |
e9d0b13b | 1384 | if (search_start == 0) |
6b80053d | 1385 | search_start = last_block; |
e9d0b13b | 1386 | |
e7a84565 | 1387 | btrfs_tree_lock(cur); |
b4ce94de | 1388 | btrfs_set_lock_blocking(cur); |
6b80053d | 1389 | err = __btrfs_cow_block(trans, root, cur, parent, i, |
e7a84565 | 1390 | &cur, search_start, |
6b80053d | 1391 | min(16 * blocksize, |
9fa8cfe7 | 1392 | (end_slot - i) * blocksize)); |
252c38f0 | 1393 | if (err) { |
e7a84565 | 1394 | btrfs_tree_unlock(cur); |
6b80053d | 1395 | free_extent_buffer(cur); |
6702ed49 | 1396 | break; |
252c38f0 | 1397 | } |
e7a84565 CM |
1398 | search_start = cur->start; |
1399 | last_block = cur->start; | |
f2183bde | 1400 | *last_ret = search_start; |
e7a84565 CM |
1401 | btrfs_tree_unlock(cur); |
1402 | free_extent_buffer(cur); | |
6702ed49 CM |
1403 | } |
1404 | return err; | |
1405 | } | |
1406 | ||
74123bd7 CM |
1407 | /* |
1408 | * The leaf data grows from end-to-front in the node. | |
1409 | * this returns the address of the start of the last item, | |
1410 | * which is the stop of the leaf data stack | |
1411 | */ | |
123abc88 | 1412 | static inline unsigned int leaf_data_end(struct btrfs_root *root, |
5f39d397 | 1413 | struct extent_buffer *leaf) |
be0e5c09 | 1414 | { |
5f39d397 | 1415 | u32 nr = btrfs_header_nritems(leaf); |
be0e5c09 | 1416 | if (nr == 0) |
123abc88 | 1417 | return BTRFS_LEAF_DATA_SIZE(root); |
5f39d397 | 1418 | return btrfs_item_offset_nr(leaf, nr - 1); |
be0e5c09 CM |
1419 | } |
1420 | ||
aa5d6bed | 1421 | |
74123bd7 | 1422 | /* |
5f39d397 CM |
1423 | * search for key in the extent_buffer. The items start at offset p, |
1424 | * and they are item_size apart. There are 'max' items in p. | |
1425 | * | |
74123bd7 CM |
1426 | * the slot in the array is returned via slot, and it points to |
1427 | * the place where you would insert key if it is not found in | |
1428 | * the array. | |
1429 | * | |
1430 | * slot may point to max if the key is bigger than all of the keys | |
1431 | */ | |
e02119d5 CM |
1432 | static noinline int generic_bin_search(struct extent_buffer *eb, |
1433 | unsigned long p, | |
1434 | int item_size, struct btrfs_key *key, | |
1435 | int max, int *slot) | |
be0e5c09 CM |
1436 | { |
1437 | int low = 0; | |
1438 | int high = max; | |
1439 | int mid; | |
1440 | int ret; | |
479965d6 | 1441 | struct btrfs_disk_key *tmp = NULL; |
5f39d397 CM |
1442 | struct btrfs_disk_key unaligned; |
1443 | unsigned long offset; | |
5f39d397 CM |
1444 | char *kaddr = NULL; |
1445 | unsigned long map_start = 0; | |
1446 | unsigned long map_len = 0; | |
479965d6 | 1447 | int err; |
be0e5c09 | 1448 | |
d397712b | 1449 | while (low < high) { |
be0e5c09 | 1450 | mid = (low + high) / 2; |
5f39d397 CM |
1451 | offset = p + mid * item_size; |
1452 | ||
a6591715 | 1453 | if (!kaddr || offset < map_start || |
5f39d397 CM |
1454 | (offset + sizeof(struct btrfs_disk_key)) > |
1455 | map_start + map_len) { | |
934d375b CM |
1456 | |
1457 | err = map_private_extent_buffer(eb, offset, | |
479965d6 | 1458 | sizeof(struct btrfs_disk_key), |
a6591715 | 1459 | &kaddr, &map_start, &map_len); |
479965d6 CM |
1460 | |
1461 | if (!err) { | |
1462 | tmp = (struct btrfs_disk_key *)(kaddr + offset - | |
1463 | map_start); | |
1464 | } else { | |
1465 | read_extent_buffer(eb, &unaligned, | |
1466 | offset, sizeof(unaligned)); | |
1467 | tmp = &unaligned; | |
1468 | } | |
5f39d397 | 1469 | |
5f39d397 CM |
1470 | } else { |
1471 | tmp = (struct btrfs_disk_key *)(kaddr + offset - | |
1472 | map_start); | |
1473 | } | |
be0e5c09 CM |
1474 | ret = comp_keys(tmp, key); |
1475 | ||
1476 | if (ret < 0) | |
1477 | low = mid + 1; | |
1478 | else if (ret > 0) | |
1479 | high = mid; | |
1480 | else { | |
1481 | *slot = mid; | |
1482 | return 0; | |
1483 | } | |
1484 | } | |
1485 | *slot = low; | |
1486 | return 1; | |
1487 | } | |
1488 | ||
97571fd0 CM |
1489 | /* |
1490 | * simple bin_search frontend that does the right thing for | |
1491 | * leaves vs nodes | |
1492 | */ | |
5f39d397 CM |
1493 | static int bin_search(struct extent_buffer *eb, struct btrfs_key *key, |
1494 | int level, int *slot) | |
be0e5c09 | 1495 | { |
5f39d397 CM |
1496 | if (level == 0) { |
1497 | return generic_bin_search(eb, | |
1498 | offsetof(struct btrfs_leaf, items), | |
0783fcfc | 1499 | sizeof(struct btrfs_item), |
5f39d397 | 1500 | key, btrfs_header_nritems(eb), |
7518a238 | 1501 | slot); |
be0e5c09 | 1502 | } else { |
5f39d397 CM |
1503 | return generic_bin_search(eb, |
1504 | offsetof(struct btrfs_node, ptrs), | |
123abc88 | 1505 | sizeof(struct btrfs_key_ptr), |
5f39d397 | 1506 | key, btrfs_header_nritems(eb), |
7518a238 | 1507 | slot); |
be0e5c09 CM |
1508 | } |
1509 | return -1; | |
1510 | } | |
1511 | ||
5d4f98a2 YZ |
1512 | int btrfs_bin_search(struct extent_buffer *eb, struct btrfs_key *key, |
1513 | int level, int *slot) | |
1514 | { | |
1515 | return bin_search(eb, key, level, slot); | |
1516 | } | |
1517 | ||
f0486c68 YZ |
1518 | static void root_add_used(struct btrfs_root *root, u32 size) |
1519 | { | |
1520 | spin_lock(&root->accounting_lock); | |
1521 | btrfs_set_root_used(&root->root_item, | |
1522 | btrfs_root_used(&root->root_item) + size); | |
1523 | spin_unlock(&root->accounting_lock); | |
1524 | } | |
1525 | ||
1526 | static void root_sub_used(struct btrfs_root *root, u32 size) | |
1527 | { | |
1528 | spin_lock(&root->accounting_lock); | |
1529 | btrfs_set_root_used(&root->root_item, | |
1530 | btrfs_root_used(&root->root_item) - size); | |
1531 | spin_unlock(&root->accounting_lock); | |
1532 | } | |
1533 | ||
d352ac68 CM |
1534 | /* given a node and slot number, this reads the blocks it points to. The |
1535 | * extent buffer is returned with a reference taken (but unlocked). | |
1536 | * NULL is returned on error. | |
1537 | */ | |
e02119d5 | 1538 | static noinline struct extent_buffer *read_node_slot(struct btrfs_root *root, |
5f39d397 | 1539 | struct extent_buffer *parent, int slot) |
bb803951 | 1540 | { |
ca7a79ad | 1541 | int level = btrfs_header_level(parent); |
bb803951 CM |
1542 | if (slot < 0) |
1543 | return NULL; | |
5f39d397 | 1544 | if (slot >= btrfs_header_nritems(parent)) |
bb803951 | 1545 | return NULL; |
ca7a79ad CM |
1546 | |
1547 | BUG_ON(level == 0); | |
1548 | ||
db94535d | 1549 | return read_tree_block(root, btrfs_node_blockptr(parent, slot), |
ca7a79ad CM |
1550 | btrfs_level_size(root, level - 1), |
1551 | btrfs_node_ptr_generation(parent, slot)); | |
bb803951 CM |
1552 | } |
1553 | ||
d352ac68 CM |
1554 | /* |
1555 | * node level balancing, used to make sure nodes are in proper order for | |
1556 | * item deletion. We balance from the top down, so we have to make sure | |
1557 | * that a deletion won't leave an node completely empty later on. | |
1558 | */ | |
e02119d5 | 1559 | static noinline int balance_level(struct btrfs_trans_handle *trans, |
98ed5174 CM |
1560 | struct btrfs_root *root, |
1561 | struct btrfs_path *path, int level) | |
bb803951 | 1562 | { |
5f39d397 CM |
1563 | struct extent_buffer *right = NULL; |
1564 | struct extent_buffer *mid; | |
1565 | struct extent_buffer *left = NULL; | |
1566 | struct extent_buffer *parent = NULL; | |
bb803951 CM |
1567 | int ret = 0; |
1568 | int wret; | |
1569 | int pslot; | |
bb803951 | 1570 | int orig_slot = path->slots[level]; |
79f95c82 | 1571 | u64 orig_ptr; |
bb803951 CM |
1572 | |
1573 | if (level == 0) | |
1574 | return 0; | |
1575 | ||
5f39d397 | 1576 | mid = path->nodes[level]; |
b4ce94de | 1577 | |
bd681513 CM |
1578 | WARN_ON(path->locks[level] != BTRFS_WRITE_LOCK && |
1579 | path->locks[level] != BTRFS_WRITE_LOCK_BLOCKING); | |
7bb86316 CM |
1580 | WARN_ON(btrfs_header_generation(mid) != trans->transid); |
1581 | ||
1d4f8a0c | 1582 | orig_ptr = btrfs_node_blockptr(mid, orig_slot); |
79f95c82 | 1583 | |
a05a9bb1 | 1584 | if (level < BTRFS_MAX_LEVEL - 1) { |
5f39d397 | 1585 | parent = path->nodes[level + 1]; |
a05a9bb1 LZ |
1586 | pslot = path->slots[level + 1]; |
1587 | } | |
bb803951 | 1588 | |
40689478 CM |
1589 | /* |
1590 | * deal with the case where there is only one pointer in the root | |
1591 | * by promoting the node below to a root | |
1592 | */ | |
5f39d397 CM |
1593 | if (!parent) { |
1594 | struct extent_buffer *child; | |
bb803951 | 1595 | |
5f39d397 | 1596 | if (btrfs_header_nritems(mid) != 1) |
bb803951 CM |
1597 | return 0; |
1598 | ||
1599 | /* promote the child to a root */ | |
5f39d397 | 1600 | child = read_node_slot(root, mid, 0); |
305a26af MF |
1601 | if (!child) { |
1602 | ret = -EROFS; | |
1603 | btrfs_std_error(root->fs_info, ret); | |
1604 | goto enospc; | |
1605 | } | |
1606 | ||
925baedd | 1607 | btrfs_tree_lock(child); |
b4ce94de | 1608 | btrfs_set_lock_blocking(child); |
9fa8cfe7 | 1609 | ret = btrfs_cow_block(trans, root, child, mid, 0, &child); |
f0486c68 YZ |
1610 | if (ret) { |
1611 | btrfs_tree_unlock(child); | |
1612 | free_extent_buffer(child); | |
1613 | goto enospc; | |
1614 | } | |
2f375ab9 | 1615 | |
f230475e | 1616 | tree_mod_log_set_root_pointer(root, child); |
240f62c8 | 1617 | rcu_assign_pointer(root->node, child); |
925baedd | 1618 | |
0b86a832 | 1619 | add_root_to_dirty_list(root); |
925baedd | 1620 | btrfs_tree_unlock(child); |
b4ce94de | 1621 | |
925baedd | 1622 | path->locks[level] = 0; |
bb803951 | 1623 | path->nodes[level] = NULL; |
5f39d397 | 1624 | clean_tree_block(trans, root, mid); |
925baedd | 1625 | btrfs_tree_unlock(mid); |
bb803951 | 1626 | /* once for the path */ |
5f39d397 | 1627 | free_extent_buffer(mid); |
f0486c68 YZ |
1628 | |
1629 | root_sub_used(root, mid->len); | |
5581a51a | 1630 | btrfs_free_tree_block(trans, root, mid, 0, 1); |
bb803951 | 1631 | /* once for the root ptr */ |
3083ee2e | 1632 | free_extent_buffer_stale(mid); |
f0486c68 | 1633 | return 0; |
bb803951 | 1634 | } |
5f39d397 | 1635 | if (btrfs_header_nritems(mid) > |
123abc88 | 1636 | BTRFS_NODEPTRS_PER_BLOCK(root) / 4) |
bb803951 CM |
1637 | return 0; |
1638 | ||
559af821 | 1639 | btrfs_header_nritems(mid); |
54aa1f4d | 1640 | |
5f39d397 CM |
1641 | left = read_node_slot(root, parent, pslot - 1); |
1642 | if (left) { | |
925baedd | 1643 | btrfs_tree_lock(left); |
b4ce94de | 1644 | btrfs_set_lock_blocking(left); |
5f39d397 | 1645 | wret = btrfs_cow_block(trans, root, left, |
9fa8cfe7 | 1646 | parent, pslot - 1, &left); |
54aa1f4d CM |
1647 | if (wret) { |
1648 | ret = wret; | |
1649 | goto enospc; | |
1650 | } | |
2cc58cf2 | 1651 | } |
5f39d397 CM |
1652 | right = read_node_slot(root, parent, pslot + 1); |
1653 | if (right) { | |
925baedd | 1654 | btrfs_tree_lock(right); |
b4ce94de | 1655 | btrfs_set_lock_blocking(right); |
5f39d397 | 1656 | wret = btrfs_cow_block(trans, root, right, |
9fa8cfe7 | 1657 | parent, pslot + 1, &right); |
2cc58cf2 CM |
1658 | if (wret) { |
1659 | ret = wret; | |
1660 | goto enospc; | |
1661 | } | |
1662 | } | |
1663 | ||
1664 | /* first, try to make some room in the middle buffer */ | |
5f39d397 CM |
1665 | if (left) { |
1666 | orig_slot += btrfs_header_nritems(left); | |
bce4eae9 | 1667 | wret = push_node_left(trans, root, left, mid, 1); |
79f95c82 CM |
1668 | if (wret < 0) |
1669 | ret = wret; | |
559af821 | 1670 | btrfs_header_nritems(mid); |
bb803951 | 1671 | } |
79f95c82 CM |
1672 | |
1673 | /* | |
1674 | * then try to empty the right most buffer into the middle | |
1675 | */ | |
5f39d397 | 1676 | if (right) { |
971a1f66 | 1677 | wret = push_node_left(trans, root, mid, right, 1); |
54aa1f4d | 1678 | if (wret < 0 && wret != -ENOSPC) |
79f95c82 | 1679 | ret = wret; |
5f39d397 | 1680 | if (btrfs_header_nritems(right) == 0) { |
5f39d397 | 1681 | clean_tree_block(trans, root, right); |
925baedd | 1682 | btrfs_tree_unlock(right); |
f3ea38da | 1683 | del_ptr(trans, root, path, level + 1, pslot + 1, 1); |
f0486c68 | 1684 | root_sub_used(root, right->len); |
5581a51a | 1685 | btrfs_free_tree_block(trans, root, right, 0, 1); |
3083ee2e | 1686 | free_extent_buffer_stale(right); |
f0486c68 | 1687 | right = NULL; |
bb803951 | 1688 | } else { |
5f39d397 CM |
1689 | struct btrfs_disk_key right_key; |
1690 | btrfs_node_key(right, &right_key, 0); | |
f230475e JS |
1691 | tree_mod_log_set_node_key(root->fs_info, parent, |
1692 | &right_key, pslot + 1, 0); | |
5f39d397 CM |
1693 | btrfs_set_node_key(parent, &right_key, pslot + 1); |
1694 | btrfs_mark_buffer_dirty(parent); | |
bb803951 CM |
1695 | } |
1696 | } | |
5f39d397 | 1697 | if (btrfs_header_nritems(mid) == 1) { |
79f95c82 CM |
1698 | /* |
1699 | * we're not allowed to leave a node with one item in the | |
1700 | * tree during a delete. A deletion from lower in the tree | |
1701 | * could try to delete the only pointer in this node. | |
1702 | * So, pull some keys from the left. | |
1703 | * There has to be a left pointer at this point because | |
1704 | * otherwise we would have pulled some pointers from the | |
1705 | * right | |
1706 | */ | |
305a26af MF |
1707 | if (!left) { |
1708 | ret = -EROFS; | |
1709 | btrfs_std_error(root->fs_info, ret); | |
1710 | goto enospc; | |
1711 | } | |
5f39d397 | 1712 | wret = balance_node_right(trans, root, mid, left); |
54aa1f4d | 1713 | if (wret < 0) { |
79f95c82 | 1714 | ret = wret; |
54aa1f4d CM |
1715 | goto enospc; |
1716 | } | |
bce4eae9 CM |
1717 | if (wret == 1) { |
1718 | wret = push_node_left(trans, root, left, mid, 1); | |
1719 | if (wret < 0) | |
1720 | ret = wret; | |
1721 | } | |
79f95c82 CM |
1722 | BUG_ON(wret == 1); |
1723 | } | |
5f39d397 | 1724 | if (btrfs_header_nritems(mid) == 0) { |
5f39d397 | 1725 | clean_tree_block(trans, root, mid); |
925baedd | 1726 | btrfs_tree_unlock(mid); |
f3ea38da | 1727 | del_ptr(trans, root, path, level + 1, pslot, 1); |
f0486c68 | 1728 | root_sub_used(root, mid->len); |
5581a51a | 1729 | btrfs_free_tree_block(trans, root, mid, 0, 1); |
3083ee2e | 1730 | free_extent_buffer_stale(mid); |
f0486c68 | 1731 | mid = NULL; |
79f95c82 CM |
1732 | } else { |
1733 | /* update the parent key to reflect our changes */ | |
5f39d397 CM |
1734 | struct btrfs_disk_key mid_key; |
1735 | btrfs_node_key(mid, &mid_key, 0); | |
f230475e JS |
1736 | tree_mod_log_set_node_key(root->fs_info, parent, &mid_key, |
1737 | pslot, 0); | |
5f39d397 CM |
1738 | btrfs_set_node_key(parent, &mid_key, pslot); |
1739 | btrfs_mark_buffer_dirty(parent); | |
79f95c82 | 1740 | } |
bb803951 | 1741 | |
79f95c82 | 1742 | /* update the path */ |
5f39d397 CM |
1743 | if (left) { |
1744 | if (btrfs_header_nritems(left) > orig_slot) { | |
1745 | extent_buffer_get(left); | |
925baedd | 1746 | /* left was locked after cow */ |
5f39d397 | 1747 | path->nodes[level] = left; |
bb803951 CM |
1748 | path->slots[level + 1] -= 1; |
1749 | path->slots[level] = orig_slot; | |
925baedd CM |
1750 | if (mid) { |
1751 | btrfs_tree_unlock(mid); | |
5f39d397 | 1752 | free_extent_buffer(mid); |
925baedd | 1753 | } |
bb803951 | 1754 | } else { |
5f39d397 | 1755 | orig_slot -= btrfs_header_nritems(left); |
bb803951 CM |
1756 | path->slots[level] = orig_slot; |
1757 | } | |
1758 | } | |
79f95c82 | 1759 | /* double check we haven't messed things up */ |
e20d96d6 | 1760 | if (orig_ptr != |
5f39d397 | 1761 | btrfs_node_blockptr(path->nodes[level], path->slots[level])) |
79f95c82 | 1762 | BUG(); |
54aa1f4d | 1763 | enospc: |
925baedd CM |
1764 | if (right) { |
1765 | btrfs_tree_unlock(right); | |
5f39d397 | 1766 | free_extent_buffer(right); |
925baedd CM |
1767 | } |
1768 | if (left) { | |
1769 | if (path->nodes[level] != left) | |
1770 | btrfs_tree_unlock(left); | |
5f39d397 | 1771 | free_extent_buffer(left); |
925baedd | 1772 | } |
bb803951 CM |
1773 | return ret; |
1774 | } | |
1775 | ||
d352ac68 CM |
1776 | /* Node balancing for insertion. Here we only split or push nodes around |
1777 | * when they are completely full. This is also done top down, so we | |
1778 | * have to be pessimistic. | |
1779 | */ | |
d397712b | 1780 | static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans, |
98ed5174 CM |
1781 | struct btrfs_root *root, |
1782 | struct btrfs_path *path, int level) | |
e66f709b | 1783 | { |
5f39d397 CM |
1784 | struct extent_buffer *right = NULL; |
1785 | struct extent_buffer *mid; | |
1786 | struct extent_buffer *left = NULL; | |
1787 | struct extent_buffer *parent = NULL; | |
e66f709b CM |
1788 | int ret = 0; |
1789 | int wret; | |
1790 | int pslot; | |
1791 | int orig_slot = path->slots[level]; | |
e66f709b CM |
1792 | |
1793 | if (level == 0) | |
1794 | return 1; | |
1795 | ||
5f39d397 | 1796 | mid = path->nodes[level]; |
7bb86316 | 1797 | WARN_ON(btrfs_header_generation(mid) != trans->transid); |
e66f709b | 1798 | |
a05a9bb1 | 1799 | if (level < BTRFS_MAX_LEVEL - 1) { |
5f39d397 | 1800 | parent = path->nodes[level + 1]; |
a05a9bb1 LZ |
1801 | pslot = path->slots[level + 1]; |
1802 | } | |
e66f709b | 1803 | |
5f39d397 | 1804 | if (!parent) |
e66f709b | 1805 | return 1; |
e66f709b | 1806 | |
5f39d397 | 1807 | left = read_node_slot(root, parent, pslot - 1); |
e66f709b CM |
1808 | |
1809 | /* first, try to make some room in the middle buffer */ | |
5f39d397 | 1810 | if (left) { |
e66f709b | 1811 | u32 left_nr; |
925baedd CM |
1812 | |
1813 | btrfs_tree_lock(left); | |
b4ce94de CM |
1814 | btrfs_set_lock_blocking(left); |
1815 | ||
5f39d397 | 1816 | left_nr = btrfs_header_nritems(left); |
33ade1f8 CM |
1817 | if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) { |
1818 | wret = 1; | |
1819 | } else { | |
5f39d397 | 1820 | ret = btrfs_cow_block(trans, root, left, parent, |
9fa8cfe7 | 1821 | pslot - 1, &left); |
54aa1f4d CM |
1822 | if (ret) |
1823 | wret = 1; | |
1824 | else { | |
54aa1f4d | 1825 | wret = push_node_left(trans, root, |
971a1f66 | 1826 | left, mid, 0); |
54aa1f4d | 1827 | } |
33ade1f8 | 1828 | } |
e66f709b CM |
1829 | if (wret < 0) |
1830 | ret = wret; | |
1831 | if (wret == 0) { | |
5f39d397 | 1832 | struct btrfs_disk_key disk_key; |
e66f709b | 1833 | orig_slot += left_nr; |
5f39d397 | 1834 | btrfs_node_key(mid, &disk_key, 0); |
f230475e JS |
1835 | tree_mod_log_set_node_key(root->fs_info, parent, |
1836 | &disk_key, pslot, 0); | |
5f39d397 CM |
1837 | btrfs_set_node_key(parent, &disk_key, pslot); |
1838 | btrfs_mark_buffer_dirty(parent); | |
1839 | if (btrfs_header_nritems(left) > orig_slot) { | |
1840 | path->nodes[level] = left; | |
e66f709b CM |
1841 | path->slots[level + 1] -= 1; |
1842 | path->slots[level] = orig_slot; | |
925baedd | 1843 | btrfs_tree_unlock(mid); |
5f39d397 | 1844 | free_extent_buffer(mid); |
e66f709b CM |
1845 | } else { |
1846 | orig_slot -= | |
5f39d397 | 1847 | btrfs_header_nritems(left); |
e66f709b | 1848 | path->slots[level] = orig_slot; |
925baedd | 1849 | btrfs_tree_unlock(left); |
5f39d397 | 1850 | free_extent_buffer(left); |
e66f709b | 1851 | } |
e66f709b CM |
1852 | return 0; |
1853 | } | |
925baedd | 1854 | btrfs_tree_unlock(left); |
5f39d397 | 1855 | free_extent_buffer(left); |
e66f709b | 1856 | } |
925baedd | 1857 | right = read_node_slot(root, parent, pslot + 1); |
e66f709b CM |
1858 | |
1859 | /* | |
1860 | * then try to empty the right most buffer into the middle | |
1861 | */ | |
5f39d397 | 1862 | if (right) { |
33ade1f8 | 1863 | u32 right_nr; |
b4ce94de | 1864 | |
925baedd | 1865 | btrfs_tree_lock(right); |
b4ce94de CM |
1866 | btrfs_set_lock_blocking(right); |
1867 | ||
5f39d397 | 1868 | right_nr = btrfs_header_nritems(right); |
33ade1f8 CM |
1869 | if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) { |
1870 | wret = 1; | |
1871 | } else { | |
5f39d397 CM |
1872 | ret = btrfs_cow_block(trans, root, right, |
1873 | parent, pslot + 1, | |
9fa8cfe7 | 1874 | &right); |
54aa1f4d CM |
1875 | if (ret) |
1876 | wret = 1; | |
1877 | else { | |
54aa1f4d | 1878 | wret = balance_node_right(trans, root, |
5f39d397 | 1879 | right, mid); |
54aa1f4d | 1880 | } |
33ade1f8 | 1881 | } |
e66f709b CM |
1882 | if (wret < 0) |
1883 | ret = wret; | |
1884 | if (wret == 0) { | |
5f39d397 CM |
1885 | struct btrfs_disk_key disk_key; |
1886 | ||
1887 | btrfs_node_key(right, &disk_key, 0); | |
f230475e JS |
1888 | tree_mod_log_set_node_key(root->fs_info, parent, |
1889 | &disk_key, pslot + 1, 0); | |
5f39d397 CM |
1890 | btrfs_set_node_key(parent, &disk_key, pslot + 1); |
1891 | btrfs_mark_buffer_dirty(parent); | |
1892 | ||
1893 | if (btrfs_header_nritems(mid) <= orig_slot) { | |
1894 | path->nodes[level] = right; | |
e66f709b CM |
1895 | path->slots[level + 1] += 1; |
1896 | path->slots[level] = orig_slot - | |
5f39d397 | 1897 | btrfs_header_nritems(mid); |
925baedd | 1898 | btrfs_tree_unlock(mid); |
5f39d397 | 1899 | free_extent_buffer(mid); |
e66f709b | 1900 | } else { |
925baedd | 1901 | btrfs_tree_unlock(right); |
5f39d397 | 1902 | free_extent_buffer(right); |
e66f709b | 1903 | } |
e66f709b CM |
1904 | return 0; |
1905 | } | |
925baedd | 1906 | btrfs_tree_unlock(right); |
5f39d397 | 1907 | free_extent_buffer(right); |
e66f709b | 1908 | } |
e66f709b CM |
1909 | return 1; |
1910 | } | |
1911 | ||
3c69faec | 1912 | /* |
d352ac68 CM |
1913 | * readahead one full node of leaves, finding things that are close |
1914 | * to the block in 'slot', and triggering ra on them. | |
3c69faec | 1915 | */ |
c8c42864 CM |
1916 | static void reada_for_search(struct btrfs_root *root, |
1917 | struct btrfs_path *path, | |
1918 | int level, int slot, u64 objectid) | |
3c69faec | 1919 | { |
5f39d397 | 1920 | struct extent_buffer *node; |
01f46658 | 1921 | struct btrfs_disk_key disk_key; |
3c69faec | 1922 | u32 nritems; |
3c69faec | 1923 | u64 search; |
a7175319 | 1924 | u64 target; |
6b80053d | 1925 | u64 nread = 0; |
cb25c2ea | 1926 | u64 gen; |
3c69faec | 1927 | int direction = path->reada; |
5f39d397 | 1928 | struct extent_buffer *eb; |
6b80053d CM |
1929 | u32 nr; |
1930 | u32 blocksize; | |
1931 | u32 nscan = 0; | |
db94535d | 1932 | |
a6b6e75e | 1933 | if (level != 1) |
6702ed49 CM |
1934 | return; |
1935 | ||
1936 | if (!path->nodes[level]) | |
3c69faec CM |
1937 | return; |
1938 | ||
5f39d397 | 1939 | node = path->nodes[level]; |
925baedd | 1940 | |
3c69faec | 1941 | search = btrfs_node_blockptr(node, slot); |
6b80053d CM |
1942 | blocksize = btrfs_level_size(root, level - 1); |
1943 | eb = btrfs_find_tree_block(root, search, blocksize); | |
5f39d397 CM |
1944 | if (eb) { |
1945 | free_extent_buffer(eb); | |
3c69faec CM |
1946 | return; |
1947 | } | |
1948 | ||
a7175319 | 1949 | target = search; |
6b80053d | 1950 | |
5f39d397 | 1951 | nritems = btrfs_header_nritems(node); |
6b80053d | 1952 | nr = slot; |
25b8b936 | 1953 | |
d397712b | 1954 | while (1) { |
6b80053d CM |
1955 | if (direction < 0) { |
1956 | if (nr == 0) | |
1957 | break; | |
1958 | nr--; | |
1959 | } else if (direction > 0) { | |
1960 | nr++; | |
1961 | if (nr >= nritems) | |
1962 | break; | |
3c69faec | 1963 | } |
01f46658 CM |
1964 | if (path->reada < 0 && objectid) { |
1965 | btrfs_node_key(node, &disk_key, nr); | |
1966 | if (btrfs_disk_key_objectid(&disk_key) != objectid) | |
1967 | break; | |
1968 | } | |
6b80053d | 1969 | search = btrfs_node_blockptr(node, nr); |
a7175319 CM |
1970 | if ((search <= target && target - search <= 65536) || |
1971 | (search > target && search - target <= 65536)) { | |
cb25c2ea | 1972 | gen = btrfs_node_ptr_generation(node, nr); |
cb25c2ea | 1973 | readahead_tree_block(root, search, blocksize, gen); |
6b80053d CM |
1974 | nread += blocksize; |
1975 | } | |
1976 | nscan++; | |
a7175319 | 1977 | if ((nread > 65536 || nscan > 32)) |
6b80053d | 1978 | break; |
3c69faec CM |
1979 | } |
1980 | } | |
925baedd | 1981 | |
b4ce94de CM |
1982 | /* |
1983 | * returns -EAGAIN if it had to drop the path, or zero if everything was in | |
1984 | * cache | |
1985 | */ | |
1986 | static noinline int reada_for_balance(struct btrfs_root *root, | |
1987 | struct btrfs_path *path, int level) | |
1988 | { | |
1989 | int slot; | |
1990 | int nritems; | |
1991 | struct extent_buffer *parent; | |
1992 | struct extent_buffer *eb; | |
1993 | u64 gen; | |
1994 | u64 block1 = 0; | |
1995 | u64 block2 = 0; | |
1996 | int ret = 0; | |
1997 | int blocksize; | |
1998 | ||
8c594ea8 | 1999 | parent = path->nodes[level + 1]; |
b4ce94de CM |
2000 | if (!parent) |
2001 | return 0; | |
2002 | ||
2003 | nritems = btrfs_header_nritems(parent); | |
8c594ea8 | 2004 | slot = path->slots[level + 1]; |
b4ce94de CM |
2005 | blocksize = btrfs_level_size(root, level); |
2006 | ||
2007 | if (slot > 0) { | |
2008 | block1 = btrfs_node_blockptr(parent, slot - 1); | |
2009 | gen = btrfs_node_ptr_generation(parent, slot - 1); | |
2010 | eb = btrfs_find_tree_block(root, block1, blocksize); | |
b9fab919 CM |
2011 | /* |
2012 | * if we get -eagain from btrfs_buffer_uptodate, we | |
2013 | * don't want to return eagain here. That will loop | |
2014 | * forever | |
2015 | */ | |
2016 | if (eb && btrfs_buffer_uptodate(eb, gen, 1) != 0) | |
b4ce94de CM |
2017 | block1 = 0; |
2018 | free_extent_buffer(eb); | |
2019 | } | |
8c594ea8 | 2020 | if (slot + 1 < nritems) { |
b4ce94de CM |
2021 | block2 = btrfs_node_blockptr(parent, slot + 1); |
2022 | gen = btrfs_node_ptr_generation(parent, slot + 1); | |
2023 | eb = btrfs_find_tree_block(root, block2, blocksize); | |
b9fab919 | 2024 | if (eb && btrfs_buffer_uptodate(eb, gen, 1) != 0) |
b4ce94de CM |
2025 | block2 = 0; |
2026 | free_extent_buffer(eb); | |
2027 | } | |
2028 | if (block1 || block2) { | |
2029 | ret = -EAGAIN; | |
8c594ea8 CM |
2030 | |
2031 | /* release the whole path */ | |
b3b4aa74 | 2032 | btrfs_release_path(path); |
8c594ea8 CM |
2033 | |
2034 | /* read the blocks */ | |
b4ce94de CM |
2035 | if (block1) |
2036 | readahead_tree_block(root, block1, blocksize, 0); | |
2037 | if (block2) | |
2038 | readahead_tree_block(root, block2, blocksize, 0); | |
2039 | ||
2040 | if (block1) { | |
2041 | eb = read_tree_block(root, block1, blocksize, 0); | |
2042 | free_extent_buffer(eb); | |
2043 | } | |
8c594ea8 | 2044 | if (block2) { |
b4ce94de CM |
2045 | eb = read_tree_block(root, block2, blocksize, 0); |
2046 | free_extent_buffer(eb); | |
2047 | } | |
2048 | } | |
2049 | return ret; | |
2050 | } | |
2051 | ||
2052 | ||
d352ac68 | 2053 | /* |
d397712b CM |
2054 | * when we walk down the tree, it is usually safe to unlock the higher layers |
2055 | * in the tree. The exceptions are when our path goes through slot 0, because | |
2056 | * operations on the tree might require changing key pointers higher up in the | |
2057 | * tree. | |
d352ac68 | 2058 | * |
d397712b CM |
2059 | * callers might also have set path->keep_locks, which tells this code to keep |
2060 | * the lock if the path points to the last slot in the block. This is part of | |
2061 | * walking through the tree, and selecting the next slot in the higher block. | |
d352ac68 | 2062 | * |
d397712b CM |
2063 | * lowest_unlock sets the lowest level in the tree we're allowed to unlock. so |
2064 | * if lowest_unlock is 1, level 0 won't be unlocked | |
d352ac68 | 2065 | */ |
e02119d5 | 2066 | static noinline void unlock_up(struct btrfs_path *path, int level, |
f7c79f30 CM |
2067 | int lowest_unlock, int min_write_lock_level, |
2068 | int *write_lock_level) | |
925baedd CM |
2069 | { |
2070 | int i; | |
2071 | int skip_level = level; | |
051e1b9f | 2072 | int no_skips = 0; |
925baedd CM |
2073 | struct extent_buffer *t; |
2074 | ||
2075 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { | |
2076 | if (!path->nodes[i]) | |
2077 | break; | |
2078 | if (!path->locks[i]) | |
2079 | break; | |
051e1b9f | 2080 | if (!no_skips && path->slots[i] == 0) { |
925baedd CM |
2081 | skip_level = i + 1; |
2082 | continue; | |
2083 | } | |
051e1b9f | 2084 | if (!no_skips && path->keep_locks) { |
925baedd CM |
2085 | u32 nritems; |
2086 | t = path->nodes[i]; | |
2087 | nritems = btrfs_header_nritems(t); | |
051e1b9f | 2088 | if (nritems < 1 || path->slots[i] >= nritems - 1) { |
925baedd CM |
2089 | skip_level = i + 1; |
2090 | continue; | |
2091 | } | |
2092 | } | |
051e1b9f CM |
2093 | if (skip_level < i && i >= lowest_unlock) |
2094 | no_skips = 1; | |
2095 | ||
925baedd CM |
2096 | t = path->nodes[i]; |
2097 | if (i >= lowest_unlock && i > skip_level && path->locks[i]) { | |
bd681513 | 2098 | btrfs_tree_unlock_rw(t, path->locks[i]); |
925baedd | 2099 | path->locks[i] = 0; |
f7c79f30 CM |
2100 | if (write_lock_level && |
2101 | i > min_write_lock_level && | |
2102 | i <= *write_lock_level) { | |
2103 | *write_lock_level = i - 1; | |
2104 | } | |
925baedd CM |
2105 | } |
2106 | } | |
2107 | } | |
2108 | ||
b4ce94de CM |
2109 | /* |
2110 | * This releases any locks held in the path starting at level and | |
2111 | * going all the way up to the root. | |
2112 | * | |
2113 | * btrfs_search_slot will keep the lock held on higher nodes in a few | |
2114 | * corner cases, such as COW of the block at slot zero in the node. This | |
2115 | * ignores those rules, and it should only be called when there are no | |
2116 | * more updates to be done higher up in the tree. | |
2117 | */ | |
2118 | noinline void btrfs_unlock_up_safe(struct btrfs_path *path, int level) | |
2119 | { | |
2120 | int i; | |
2121 | ||
5d4f98a2 | 2122 | if (path->keep_locks) |
b4ce94de CM |
2123 | return; |
2124 | ||
2125 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { | |
2126 | if (!path->nodes[i]) | |
12f4dacc | 2127 | continue; |
b4ce94de | 2128 | if (!path->locks[i]) |
12f4dacc | 2129 | continue; |
bd681513 | 2130 | btrfs_tree_unlock_rw(path->nodes[i], path->locks[i]); |
b4ce94de CM |
2131 | path->locks[i] = 0; |
2132 | } | |
2133 | } | |
2134 | ||
c8c42864 CM |
2135 | /* |
2136 | * helper function for btrfs_search_slot. The goal is to find a block | |
2137 | * in cache without setting the path to blocking. If we find the block | |
2138 | * we return zero and the path is unchanged. | |
2139 | * | |
2140 | * If we can't find the block, we set the path blocking and do some | |
2141 | * reada. -EAGAIN is returned and the search must be repeated. | |
2142 | */ | |
2143 | static int | |
2144 | read_block_for_search(struct btrfs_trans_handle *trans, | |
2145 | struct btrfs_root *root, struct btrfs_path *p, | |
2146 | struct extent_buffer **eb_ret, int level, int slot, | |
5d9e75c4 | 2147 | struct btrfs_key *key, u64 time_seq) |
c8c42864 CM |
2148 | { |
2149 | u64 blocknr; | |
2150 | u64 gen; | |
2151 | u32 blocksize; | |
2152 | struct extent_buffer *b = *eb_ret; | |
2153 | struct extent_buffer *tmp; | |
76a05b35 | 2154 | int ret; |
c8c42864 CM |
2155 | |
2156 | blocknr = btrfs_node_blockptr(b, slot); | |
2157 | gen = btrfs_node_ptr_generation(b, slot); | |
2158 | blocksize = btrfs_level_size(root, level - 1); | |
2159 | ||
2160 | tmp = btrfs_find_tree_block(root, blocknr, blocksize); | |
cb44921a | 2161 | if (tmp) { |
b9fab919 CM |
2162 | /* first we do an atomic uptodate check */ |
2163 | if (btrfs_buffer_uptodate(tmp, 0, 1) > 0) { | |
2164 | if (btrfs_buffer_uptodate(tmp, gen, 1) > 0) { | |
cb44921a CM |
2165 | /* |
2166 | * we found an up to date block without | |
2167 | * sleeping, return | |
2168 | * right away | |
2169 | */ | |
2170 | *eb_ret = tmp; | |
2171 | return 0; | |
2172 | } | |
2173 | /* the pages were up to date, but we failed | |
2174 | * the generation number check. Do a full | |
2175 | * read for the generation number that is correct. | |
2176 | * We must do this without dropping locks so | |
2177 | * we can trust our generation number | |
2178 | */ | |
2179 | free_extent_buffer(tmp); | |
bd681513 CM |
2180 | btrfs_set_path_blocking(p); |
2181 | ||
b9fab919 | 2182 | /* now we're allowed to do a blocking uptodate check */ |
cb44921a | 2183 | tmp = read_tree_block(root, blocknr, blocksize, gen); |
b9fab919 | 2184 | if (tmp && btrfs_buffer_uptodate(tmp, gen, 0) > 0) { |
cb44921a CM |
2185 | *eb_ret = tmp; |
2186 | return 0; | |
2187 | } | |
2188 | free_extent_buffer(tmp); | |
b3b4aa74 | 2189 | btrfs_release_path(p); |
cb44921a CM |
2190 | return -EIO; |
2191 | } | |
c8c42864 CM |
2192 | } |
2193 | ||
2194 | /* | |
2195 | * reduce lock contention at high levels | |
2196 | * of the btree by dropping locks before | |
76a05b35 CM |
2197 | * we read. Don't release the lock on the current |
2198 | * level because we need to walk this node to figure | |
2199 | * out which blocks to read. | |
c8c42864 | 2200 | */ |
8c594ea8 CM |
2201 | btrfs_unlock_up_safe(p, level + 1); |
2202 | btrfs_set_path_blocking(p); | |
2203 | ||
cb44921a | 2204 | free_extent_buffer(tmp); |
c8c42864 CM |
2205 | if (p->reada) |
2206 | reada_for_search(root, p, level, slot, key->objectid); | |
2207 | ||
b3b4aa74 | 2208 | btrfs_release_path(p); |
76a05b35 CM |
2209 | |
2210 | ret = -EAGAIN; | |
5bdd3536 | 2211 | tmp = read_tree_block(root, blocknr, blocksize, 0); |
76a05b35 CM |
2212 | if (tmp) { |
2213 | /* | |
2214 | * If the read above didn't mark this buffer up to date, | |
2215 | * it will never end up being up to date. Set ret to EIO now | |
2216 | * and give up so that our caller doesn't loop forever | |
2217 | * on our EAGAINs. | |
2218 | */ | |
b9fab919 | 2219 | if (!btrfs_buffer_uptodate(tmp, 0, 0)) |
76a05b35 | 2220 | ret = -EIO; |
c8c42864 | 2221 | free_extent_buffer(tmp); |
76a05b35 CM |
2222 | } |
2223 | return ret; | |
c8c42864 CM |
2224 | } |
2225 | ||
2226 | /* | |
2227 | * helper function for btrfs_search_slot. This does all of the checks | |
2228 | * for node-level blocks and does any balancing required based on | |
2229 | * the ins_len. | |
2230 | * | |
2231 | * If no extra work was required, zero is returned. If we had to | |
2232 | * drop the path, -EAGAIN is returned and btrfs_search_slot must | |
2233 | * start over | |
2234 | */ | |
2235 | static int | |
2236 | setup_nodes_for_search(struct btrfs_trans_handle *trans, | |
2237 | struct btrfs_root *root, struct btrfs_path *p, | |
bd681513 CM |
2238 | struct extent_buffer *b, int level, int ins_len, |
2239 | int *write_lock_level) | |
c8c42864 CM |
2240 | { |
2241 | int ret; | |
2242 | if ((p->search_for_split || ins_len > 0) && btrfs_header_nritems(b) >= | |
2243 | BTRFS_NODEPTRS_PER_BLOCK(root) - 3) { | |
2244 | int sret; | |
2245 | ||
bd681513 CM |
2246 | if (*write_lock_level < level + 1) { |
2247 | *write_lock_level = level + 1; | |
2248 | btrfs_release_path(p); | |
2249 | goto again; | |
2250 | } | |
2251 | ||
c8c42864 CM |
2252 | sret = reada_for_balance(root, p, level); |
2253 | if (sret) | |
2254 | goto again; | |
2255 | ||
2256 | btrfs_set_path_blocking(p); | |
2257 | sret = split_node(trans, root, p, level); | |
bd681513 | 2258 | btrfs_clear_path_blocking(p, NULL, 0); |
c8c42864 CM |
2259 | |
2260 | BUG_ON(sret > 0); | |
2261 | if (sret) { | |
2262 | ret = sret; | |
2263 | goto done; | |
2264 | } | |
2265 | b = p->nodes[level]; | |
2266 | } else if (ins_len < 0 && btrfs_header_nritems(b) < | |
cfbb9308 | 2267 | BTRFS_NODEPTRS_PER_BLOCK(root) / 2) { |
c8c42864 CM |
2268 | int sret; |
2269 | ||
bd681513 CM |
2270 | if (*write_lock_level < level + 1) { |
2271 | *write_lock_level = level + 1; | |
2272 | btrfs_release_path(p); | |
2273 | goto again; | |
2274 | } | |
2275 | ||
c8c42864 CM |
2276 | sret = reada_for_balance(root, p, level); |
2277 | if (sret) | |
2278 | goto again; | |
2279 | ||
2280 | btrfs_set_path_blocking(p); | |
2281 | sret = balance_level(trans, root, p, level); | |
bd681513 | 2282 | btrfs_clear_path_blocking(p, NULL, 0); |
c8c42864 CM |
2283 | |
2284 | if (sret) { | |
2285 | ret = sret; | |
2286 | goto done; | |
2287 | } | |
2288 | b = p->nodes[level]; | |
2289 | if (!b) { | |
b3b4aa74 | 2290 | btrfs_release_path(p); |
c8c42864 CM |
2291 | goto again; |
2292 | } | |
2293 | BUG_ON(btrfs_header_nritems(b) == 1); | |
2294 | } | |
2295 | return 0; | |
2296 | ||
2297 | again: | |
2298 | ret = -EAGAIN; | |
2299 | done: | |
2300 | return ret; | |
2301 | } | |
2302 | ||
74123bd7 CM |
2303 | /* |
2304 | * look for key in the tree. path is filled in with nodes along the way | |
2305 | * if key is found, we return zero and you can find the item in the leaf | |
2306 | * level of the path (level 0) | |
2307 | * | |
2308 | * If the key isn't found, the path points to the slot where it should | |
aa5d6bed CM |
2309 | * be inserted, and 1 is returned. If there are other errors during the |
2310 | * search a negative error number is returned. | |
97571fd0 CM |
2311 | * |
2312 | * if ins_len > 0, nodes and leaves will be split as we walk down the | |
2313 | * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if | |
2314 | * possible) | |
74123bd7 | 2315 | */ |
e089f05c CM |
2316 | int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root |
2317 | *root, struct btrfs_key *key, struct btrfs_path *p, int | |
2318 | ins_len, int cow) | |
be0e5c09 | 2319 | { |
5f39d397 | 2320 | struct extent_buffer *b; |
be0e5c09 CM |
2321 | int slot; |
2322 | int ret; | |
33c66f43 | 2323 | int err; |
be0e5c09 | 2324 | int level; |
925baedd | 2325 | int lowest_unlock = 1; |
bd681513 CM |
2326 | int root_lock; |
2327 | /* everything at write_lock_level or lower must be write locked */ | |
2328 | int write_lock_level = 0; | |
9f3a7427 | 2329 | u8 lowest_level = 0; |
f7c79f30 | 2330 | int min_write_lock_level; |
9f3a7427 | 2331 | |
6702ed49 | 2332 | lowest_level = p->lowest_level; |
323ac95b | 2333 | WARN_ON(lowest_level && ins_len > 0); |
22b0ebda | 2334 | WARN_ON(p->nodes[0] != NULL); |
25179201 | 2335 | |
bd681513 | 2336 | if (ins_len < 0) { |
925baedd | 2337 | lowest_unlock = 2; |
65b51a00 | 2338 | |
bd681513 CM |
2339 | /* when we are removing items, we might have to go up to level |
2340 | * two as we update tree pointers Make sure we keep write | |
2341 | * for those levels as well | |
2342 | */ | |
2343 | write_lock_level = 2; | |
2344 | } else if (ins_len > 0) { | |
2345 | /* | |
2346 | * for inserting items, make sure we have a write lock on | |
2347 | * level 1 so we can update keys | |
2348 | */ | |
2349 | write_lock_level = 1; | |
2350 | } | |
2351 | ||
2352 | if (!cow) | |
2353 | write_lock_level = -1; | |
2354 | ||
2355 | if (cow && (p->keep_locks || p->lowest_level)) | |
2356 | write_lock_level = BTRFS_MAX_LEVEL; | |
2357 | ||
f7c79f30 CM |
2358 | min_write_lock_level = write_lock_level; |
2359 | ||
bb803951 | 2360 | again: |
bd681513 CM |
2361 | /* |
2362 | * we try very hard to do read locks on the root | |
2363 | */ | |
2364 | root_lock = BTRFS_READ_LOCK; | |
2365 | level = 0; | |
5d4f98a2 | 2366 | if (p->search_commit_root) { |
bd681513 CM |
2367 | /* |
2368 | * the commit roots are read only | |
2369 | * so we always do read locks | |
2370 | */ | |
5d4f98a2 YZ |
2371 | b = root->commit_root; |
2372 | extent_buffer_get(b); | |
bd681513 | 2373 | level = btrfs_header_level(b); |
5d4f98a2 | 2374 | if (!p->skip_locking) |
bd681513 | 2375 | btrfs_tree_read_lock(b); |
5d4f98a2 | 2376 | } else { |
bd681513 | 2377 | if (p->skip_locking) { |
5d4f98a2 | 2378 | b = btrfs_root_node(root); |
bd681513 CM |
2379 | level = btrfs_header_level(b); |
2380 | } else { | |
2381 | /* we don't know the level of the root node | |
2382 | * until we actually have it read locked | |
2383 | */ | |
2384 | b = btrfs_read_lock_root_node(root); | |
2385 | level = btrfs_header_level(b); | |
2386 | if (level <= write_lock_level) { | |
2387 | /* whoops, must trade for write lock */ | |
2388 | btrfs_tree_read_unlock(b); | |
2389 | free_extent_buffer(b); | |
2390 | b = btrfs_lock_root_node(root); | |
2391 | root_lock = BTRFS_WRITE_LOCK; | |
2392 | ||
2393 | /* the level might have changed, check again */ | |
2394 | level = btrfs_header_level(b); | |
2395 | } | |
2396 | } | |
5d4f98a2 | 2397 | } |
bd681513 CM |
2398 | p->nodes[level] = b; |
2399 | if (!p->skip_locking) | |
2400 | p->locks[level] = root_lock; | |
925baedd | 2401 | |
eb60ceac | 2402 | while (b) { |
5f39d397 | 2403 | level = btrfs_header_level(b); |
65b51a00 CM |
2404 | |
2405 | /* | |
2406 | * setup the path here so we can release it under lock | |
2407 | * contention with the cow code | |
2408 | */ | |
02217ed2 | 2409 | if (cow) { |
c8c42864 CM |
2410 | /* |
2411 | * if we don't really need to cow this block | |
2412 | * then we don't want to set the path blocking, | |
2413 | * so we test it here | |
2414 | */ | |
5d4f98a2 | 2415 | if (!should_cow_block(trans, root, b)) |
65b51a00 | 2416 | goto cow_done; |
5d4f98a2 | 2417 | |
b4ce94de CM |
2418 | btrfs_set_path_blocking(p); |
2419 | ||
bd681513 CM |
2420 | /* |
2421 | * must have write locks on this node and the | |
2422 | * parent | |
2423 | */ | |
2424 | if (level + 1 > write_lock_level) { | |
2425 | write_lock_level = level + 1; | |
2426 | btrfs_release_path(p); | |
2427 | goto again; | |
2428 | } | |
2429 | ||
33c66f43 YZ |
2430 | err = btrfs_cow_block(trans, root, b, |
2431 | p->nodes[level + 1], | |
2432 | p->slots[level + 1], &b); | |
2433 | if (err) { | |
33c66f43 | 2434 | ret = err; |
65b51a00 | 2435 | goto done; |
54aa1f4d | 2436 | } |
02217ed2 | 2437 | } |
65b51a00 | 2438 | cow_done: |
02217ed2 | 2439 | BUG_ON(!cow && ins_len); |
65b51a00 | 2440 | |
eb60ceac | 2441 | p->nodes[level] = b; |
bd681513 | 2442 | btrfs_clear_path_blocking(p, NULL, 0); |
b4ce94de CM |
2443 | |
2444 | /* | |
2445 | * we have a lock on b and as long as we aren't changing | |
2446 | * the tree, there is no way to for the items in b to change. | |
2447 | * It is safe to drop the lock on our parent before we | |
2448 | * go through the expensive btree search on b. | |
2449 | * | |
2450 | * If cow is true, then we might be changing slot zero, | |
2451 | * which may require changing the parent. So, we can't | |
2452 | * drop the lock until after we know which slot we're | |
2453 | * operating on. | |
2454 | */ | |
2455 | if (!cow) | |
2456 | btrfs_unlock_up_safe(p, level + 1); | |
2457 | ||
5f39d397 | 2458 | ret = bin_search(b, key, level, &slot); |
b4ce94de | 2459 | |
5f39d397 | 2460 | if (level != 0) { |
33c66f43 YZ |
2461 | int dec = 0; |
2462 | if (ret && slot > 0) { | |
2463 | dec = 1; | |
be0e5c09 | 2464 | slot -= 1; |
33c66f43 | 2465 | } |
be0e5c09 | 2466 | p->slots[level] = slot; |
33c66f43 | 2467 | err = setup_nodes_for_search(trans, root, p, b, level, |
bd681513 | 2468 | ins_len, &write_lock_level); |
33c66f43 | 2469 | if (err == -EAGAIN) |
c8c42864 | 2470 | goto again; |
33c66f43 YZ |
2471 | if (err) { |
2472 | ret = err; | |
c8c42864 | 2473 | goto done; |
33c66f43 | 2474 | } |
c8c42864 CM |
2475 | b = p->nodes[level]; |
2476 | slot = p->slots[level]; | |
b4ce94de | 2477 | |
bd681513 CM |
2478 | /* |
2479 | * slot 0 is special, if we change the key | |
2480 | * we have to update the parent pointer | |
2481 | * which means we must have a write lock | |
2482 | * on the parent | |
2483 | */ | |
2484 | if (slot == 0 && cow && | |
2485 | write_lock_level < level + 1) { | |
2486 | write_lock_level = level + 1; | |
2487 | btrfs_release_path(p); | |
2488 | goto again; | |
2489 | } | |
2490 | ||
f7c79f30 CM |
2491 | unlock_up(p, level, lowest_unlock, |
2492 | min_write_lock_level, &write_lock_level); | |
f9efa9c7 | 2493 | |
925baedd | 2494 | if (level == lowest_level) { |
33c66f43 YZ |
2495 | if (dec) |
2496 | p->slots[level]++; | |
5b21f2ed | 2497 | goto done; |
925baedd | 2498 | } |
ca7a79ad | 2499 | |
33c66f43 | 2500 | err = read_block_for_search(trans, root, p, |
5d9e75c4 | 2501 | &b, level, slot, key, 0); |
33c66f43 | 2502 | if (err == -EAGAIN) |
c8c42864 | 2503 | goto again; |
33c66f43 YZ |
2504 | if (err) { |
2505 | ret = err; | |
76a05b35 | 2506 | goto done; |
33c66f43 | 2507 | } |
76a05b35 | 2508 | |
b4ce94de | 2509 | if (!p->skip_locking) { |
bd681513 CM |
2510 | level = btrfs_header_level(b); |
2511 | if (level <= write_lock_level) { | |
2512 | err = btrfs_try_tree_write_lock(b); | |
2513 | if (!err) { | |
2514 | btrfs_set_path_blocking(p); | |
2515 | btrfs_tree_lock(b); | |
2516 | btrfs_clear_path_blocking(p, b, | |
2517 | BTRFS_WRITE_LOCK); | |
2518 | } | |
2519 | p->locks[level] = BTRFS_WRITE_LOCK; | |
2520 | } else { | |
2521 | err = btrfs_try_tree_read_lock(b); | |
2522 | if (!err) { | |
2523 | btrfs_set_path_blocking(p); | |
2524 | btrfs_tree_read_lock(b); | |
2525 | btrfs_clear_path_blocking(p, b, | |
2526 | BTRFS_READ_LOCK); | |
2527 | } | |
2528 | p->locks[level] = BTRFS_READ_LOCK; | |
b4ce94de | 2529 | } |
bd681513 | 2530 | p->nodes[level] = b; |
b4ce94de | 2531 | } |
be0e5c09 CM |
2532 | } else { |
2533 | p->slots[level] = slot; | |
87b29b20 YZ |
2534 | if (ins_len > 0 && |
2535 | btrfs_leaf_free_space(root, b) < ins_len) { | |
bd681513 CM |
2536 | if (write_lock_level < 1) { |
2537 | write_lock_level = 1; | |
2538 | btrfs_release_path(p); | |
2539 | goto again; | |
2540 | } | |
2541 | ||
b4ce94de | 2542 | btrfs_set_path_blocking(p); |
33c66f43 YZ |
2543 | err = split_leaf(trans, root, key, |
2544 | p, ins_len, ret == 0); | |
bd681513 | 2545 | btrfs_clear_path_blocking(p, NULL, 0); |
b4ce94de | 2546 | |
33c66f43 YZ |
2547 | BUG_ON(err > 0); |
2548 | if (err) { | |
2549 | ret = err; | |
65b51a00 CM |
2550 | goto done; |
2551 | } | |
5c680ed6 | 2552 | } |
459931ec | 2553 | if (!p->search_for_split) |
f7c79f30 CM |
2554 | unlock_up(p, level, lowest_unlock, |
2555 | min_write_lock_level, &write_lock_level); | |
65b51a00 | 2556 | goto done; |
be0e5c09 CM |
2557 | } |
2558 | } | |
65b51a00 CM |
2559 | ret = 1; |
2560 | done: | |
b4ce94de CM |
2561 | /* |
2562 | * we don't really know what they plan on doing with the path | |
2563 | * from here on, so for now just mark it as blocking | |
2564 | */ | |
b9473439 CM |
2565 | if (!p->leave_spinning) |
2566 | btrfs_set_path_blocking(p); | |
76a05b35 | 2567 | if (ret < 0) |
b3b4aa74 | 2568 | btrfs_release_path(p); |
65b51a00 | 2569 | return ret; |
be0e5c09 CM |
2570 | } |
2571 | ||
5d9e75c4 JS |
2572 | /* |
2573 | * Like btrfs_search_slot, this looks for a key in the given tree. It uses the | |
2574 | * current state of the tree together with the operations recorded in the tree | |
2575 | * modification log to search for the key in a previous version of this tree, as | |
2576 | * denoted by the time_seq parameter. | |
2577 | * | |
2578 | * Naturally, there is no support for insert, delete or cow operations. | |
2579 | * | |
2580 | * The resulting path and return value will be set up as if we called | |
2581 | * btrfs_search_slot at that point in time with ins_len and cow both set to 0. | |
2582 | */ | |
2583 | int btrfs_search_old_slot(struct btrfs_root *root, struct btrfs_key *key, | |
2584 | struct btrfs_path *p, u64 time_seq) | |
2585 | { | |
2586 | struct extent_buffer *b; | |
2587 | int slot; | |
2588 | int ret; | |
2589 | int err; | |
2590 | int level; | |
2591 | int lowest_unlock = 1; | |
2592 | u8 lowest_level = 0; | |
2593 | ||
2594 | lowest_level = p->lowest_level; | |
2595 | WARN_ON(p->nodes[0] != NULL); | |
2596 | ||
2597 | if (p->search_commit_root) { | |
2598 | BUG_ON(time_seq); | |
2599 | return btrfs_search_slot(NULL, root, key, p, 0, 0); | |
2600 | } | |
2601 | ||
2602 | again: | |
2603 | level = 0; | |
2604 | b = get_old_root(root, time_seq); | |
2605 | extent_buffer_get(b); | |
2606 | level = btrfs_header_level(b); | |
2607 | btrfs_tree_read_lock(b); | |
2608 | p->locks[level] = BTRFS_READ_LOCK; | |
2609 | ||
2610 | while (b) { | |
2611 | level = btrfs_header_level(b); | |
2612 | p->nodes[level] = b; | |
2613 | btrfs_clear_path_blocking(p, NULL, 0); | |
2614 | ||
2615 | /* | |
2616 | * we have a lock on b and as long as we aren't changing | |
2617 | * the tree, there is no way to for the items in b to change. | |
2618 | * It is safe to drop the lock on our parent before we | |
2619 | * go through the expensive btree search on b. | |
2620 | */ | |
2621 | btrfs_unlock_up_safe(p, level + 1); | |
2622 | ||
2623 | ret = bin_search(b, key, level, &slot); | |
2624 | ||
2625 | if (level != 0) { | |
2626 | int dec = 0; | |
2627 | if (ret && slot > 0) { | |
2628 | dec = 1; | |
2629 | slot -= 1; | |
2630 | } | |
2631 | p->slots[level] = slot; | |
2632 | unlock_up(p, level, lowest_unlock, 0, NULL); | |
2633 | ||
2634 | if (level == lowest_level) { | |
2635 | if (dec) | |
2636 | p->slots[level]++; | |
2637 | goto done; | |
2638 | } | |
2639 | ||
2640 | err = read_block_for_search(NULL, root, p, &b, level, | |
2641 | slot, key, time_seq); | |
2642 | if (err == -EAGAIN) | |
2643 | goto again; | |
2644 | if (err) { | |
2645 | ret = err; | |
2646 | goto done; | |
2647 | } | |
2648 | ||
2649 | level = btrfs_header_level(b); | |
2650 | err = btrfs_try_tree_read_lock(b); | |
2651 | if (!err) { | |
2652 | btrfs_set_path_blocking(p); | |
2653 | btrfs_tree_read_lock(b); | |
2654 | btrfs_clear_path_blocking(p, b, | |
2655 | BTRFS_READ_LOCK); | |
2656 | } | |
2657 | p->locks[level] = BTRFS_READ_LOCK; | |
2658 | p->nodes[level] = b; | |
2659 | b = tree_mod_log_rewind(root->fs_info, b, time_seq); | |
2660 | if (b != p->nodes[level]) { | |
2661 | btrfs_tree_unlock_rw(p->nodes[level], | |
2662 | p->locks[level]); | |
2663 | p->locks[level] = 0; | |
2664 | p->nodes[level] = b; | |
2665 | } | |
2666 | } else { | |
2667 | p->slots[level] = slot; | |
2668 | unlock_up(p, level, lowest_unlock, 0, NULL); | |
2669 | goto done; | |
2670 | } | |
2671 | } | |
2672 | ret = 1; | |
2673 | done: | |
2674 | if (!p->leave_spinning) | |
2675 | btrfs_set_path_blocking(p); | |
2676 | if (ret < 0) | |
2677 | btrfs_release_path(p); | |
2678 | ||
2679 | return ret; | |
2680 | } | |
2681 | ||
74123bd7 CM |
2682 | /* |
2683 | * adjust the pointers going up the tree, starting at level | |
2684 | * making sure the right key of each node is points to 'key'. | |
2685 | * This is used after shifting pointers to the left, so it stops | |
2686 | * fixing up pointers when a given leaf/node is not in slot 0 of the | |
2687 | * higher levels | |
aa5d6bed | 2688 | * |
74123bd7 | 2689 | */ |
143bede5 JM |
2690 | static void fixup_low_keys(struct btrfs_trans_handle *trans, |
2691 | struct btrfs_root *root, struct btrfs_path *path, | |
2692 | struct btrfs_disk_key *key, int level) | |
be0e5c09 CM |
2693 | { |
2694 | int i; | |
5f39d397 CM |
2695 | struct extent_buffer *t; |
2696 | ||
234b63a0 | 2697 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { |
be0e5c09 | 2698 | int tslot = path->slots[i]; |
eb60ceac | 2699 | if (!path->nodes[i]) |
be0e5c09 | 2700 | break; |
5f39d397 | 2701 | t = path->nodes[i]; |
f230475e | 2702 | tree_mod_log_set_node_key(root->fs_info, t, key, tslot, 1); |
5f39d397 | 2703 | btrfs_set_node_key(t, key, tslot); |
d6025579 | 2704 | btrfs_mark_buffer_dirty(path->nodes[i]); |
be0e5c09 CM |
2705 | if (tslot != 0) |
2706 | break; | |
2707 | } | |
2708 | } | |
2709 | ||
31840ae1 ZY |
2710 | /* |
2711 | * update item key. | |
2712 | * | |
2713 | * This function isn't completely safe. It's the caller's responsibility | |
2714 | * that the new key won't break the order | |
2715 | */ | |
143bede5 JM |
2716 | void btrfs_set_item_key_safe(struct btrfs_trans_handle *trans, |
2717 | struct btrfs_root *root, struct btrfs_path *path, | |
2718 | struct btrfs_key *new_key) | |
31840ae1 ZY |
2719 | { |
2720 | struct btrfs_disk_key disk_key; | |
2721 | struct extent_buffer *eb; | |
2722 | int slot; | |
2723 | ||
2724 | eb = path->nodes[0]; | |
2725 | slot = path->slots[0]; | |
2726 | if (slot > 0) { | |
2727 | btrfs_item_key(eb, &disk_key, slot - 1); | |
143bede5 | 2728 | BUG_ON(comp_keys(&disk_key, new_key) >= 0); |
31840ae1 ZY |
2729 | } |
2730 | if (slot < btrfs_header_nritems(eb) - 1) { | |
2731 | btrfs_item_key(eb, &disk_key, slot + 1); | |
143bede5 | 2732 | BUG_ON(comp_keys(&disk_key, new_key) <= 0); |
31840ae1 ZY |
2733 | } |
2734 | ||
2735 | btrfs_cpu_key_to_disk(&disk_key, new_key); | |
2736 | btrfs_set_item_key(eb, &disk_key, slot); | |
2737 | btrfs_mark_buffer_dirty(eb); | |
2738 | if (slot == 0) | |
2739 | fixup_low_keys(trans, root, path, &disk_key, 1); | |
31840ae1 ZY |
2740 | } |
2741 | ||
74123bd7 CM |
2742 | /* |
2743 | * try to push data from one node into the next node left in the | |
79f95c82 | 2744 | * tree. |
aa5d6bed CM |
2745 | * |
2746 | * returns 0 if some ptrs were pushed left, < 0 if there was some horrible | |
2747 | * error, and > 0 if there was no room in the left hand block. | |
74123bd7 | 2748 | */ |
98ed5174 CM |
2749 | static int push_node_left(struct btrfs_trans_handle *trans, |
2750 | struct btrfs_root *root, struct extent_buffer *dst, | |
971a1f66 | 2751 | struct extent_buffer *src, int empty) |
be0e5c09 | 2752 | { |
be0e5c09 | 2753 | int push_items = 0; |
bb803951 CM |
2754 | int src_nritems; |
2755 | int dst_nritems; | |
aa5d6bed | 2756 | int ret = 0; |
be0e5c09 | 2757 | |
5f39d397 CM |
2758 | src_nritems = btrfs_header_nritems(src); |
2759 | dst_nritems = btrfs_header_nritems(dst); | |
123abc88 | 2760 | push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems; |
7bb86316 CM |
2761 | WARN_ON(btrfs_header_generation(src) != trans->transid); |
2762 | WARN_ON(btrfs_header_generation(dst) != trans->transid); | |
54aa1f4d | 2763 | |
bce4eae9 | 2764 | if (!empty && src_nritems <= 8) |
971a1f66 CM |
2765 | return 1; |
2766 | ||
d397712b | 2767 | if (push_items <= 0) |
be0e5c09 CM |
2768 | return 1; |
2769 | ||
bce4eae9 | 2770 | if (empty) { |
971a1f66 | 2771 | push_items = min(src_nritems, push_items); |
bce4eae9 CM |
2772 | if (push_items < src_nritems) { |
2773 | /* leave at least 8 pointers in the node if | |
2774 | * we aren't going to empty it | |
2775 | */ | |
2776 | if (src_nritems - push_items < 8) { | |
2777 | if (push_items <= 8) | |
2778 | return 1; | |
2779 | push_items -= 8; | |
2780 | } | |
2781 | } | |
2782 | } else | |
2783 | push_items = min(src_nritems - 8, push_items); | |
79f95c82 | 2784 | |
f230475e JS |
2785 | tree_mod_log_eb_copy(root->fs_info, dst, src, dst_nritems, 0, |
2786 | push_items); | |
5f39d397 CM |
2787 | copy_extent_buffer(dst, src, |
2788 | btrfs_node_key_ptr_offset(dst_nritems), | |
2789 | btrfs_node_key_ptr_offset(0), | |
d397712b | 2790 | push_items * sizeof(struct btrfs_key_ptr)); |
5f39d397 | 2791 | |
bb803951 | 2792 | if (push_items < src_nritems) { |
f230475e JS |
2793 | tree_mod_log_eb_move(root->fs_info, src, 0, push_items, |
2794 | src_nritems - push_items); | |
5f39d397 CM |
2795 | memmove_extent_buffer(src, btrfs_node_key_ptr_offset(0), |
2796 | btrfs_node_key_ptr_offset(push_items), | |
2797 | (src_nritems - push_items) * | |
2798 | sizeof(struct btrfs_key_ptr)); | |
2799 | } | |
2800 | btrfs_set_header_nritems(src, src_nritems - push_items); | |
2801 | btrfs_set_header_nritems(dst, dst_nritems + push_items); | |
2802 | btrfs_mark_buffer_dirty(src); | |
2803 | btrfs_mark_buffer_dirty(dst); | |
31840ae1 | 2804 | |
79f95c82 CM |
2805 | return ret; |
2806 | } | |
2807 | ||
2808 | /* | |
2809 | * try to push data from one node into the next node right in the | |
2810 | * tree. | |
2811 | * | |
2812 | * returns 0 if some ptrs were pushed, < 0 if there was some horrible | |
2813 | * error, and > 0 if there was no room in the right hand block. | |
2814 | * | |
2815 | * this will only push up to 1/2 the contents of the left node over | |
2816 | */ | |
5f39d397 CM |
2817 | static int balance_node_right(struct btrfs_trans_handle *trans, |
2818 | struct btrfs_root *root, | |
2819 | struct extent_buffer *dst, | |
2820 | struct extent_buffer *src) | |
79f95c82 | 2821 | { |
79f95c82 CM |
2822 | int push_items = 0; |
2823 | int max_push; | |
2824 | int src_nritems; | |
2825 | int dst_nritems; | |
2826 | int ret = 0; | |
79f95c82 | 2827 | |
7bb86316 CM |
2828 | WARN_ON(btrfs_header_generation(src) != trans->transid); |
2829 | WARN_ON(btrfs_header_generation(dst) != trans->transid); | |
2830 | ||
5f39d397 CM |
2831 | src_nritems = btrfs_header_nritems(src); |
2832 | dst_nritems = btrfs_header_nritems(dst); | |
123abc88 | 2833 | push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems; |
d397712b | 2834 | if (push_items <= 0) |
79f95c82 | 2835 | return 1; |
bce4eae9 | 2836 | |
d397712b | 2837 | if (src_nritems < 4) |
bce4eae9 | 2838 | return 1; |
79f95c82 CM |
2839 | |
2840 | max_push = src_nritems / 2 + 1; | |
2841 | /* don't try to empty the node */ | |
d397712b | 2842 | if (max_push >= src_nritems) |
79f95c82 | 2843 | return 1; |
252c38f0 | 2844 | |
79f95c82 CM |
2845 | if (max_push < push_items) |
2846 | push_items = max_push; | |
2847 | ||
f230475e | 2848 | tree_mod_log_eb_move(root->fs_info, dst, push_items, 0, dst_nritems); |
5f39d397 CM |
2849 | memmove_extent_buffer(dst, btrfs_node_key_ptr_offset(push_items), |
2850 | btrfs_node_key_ptr_offset(0), | |
2851 | (dst_nritems) * | |
2852 | sizeof(struct btrfs_key_ptr)); | |
d6025579 | 2853 | |
f230475e JS |
2854 | tree_mod_log_eb_copy(root->fs_info, dst, src, 0, |
2855 | src_nritems - push_items, push_items); | |
5f39d397 CM |
2856 | copy_extent_buffer(dst, src, |
2857 | btrfs_node_key_ptr_offset(0), | |
2858 | btrfs_node_key_ptr_offset(src_nritems - push_items), | |
d397712b | 2859 | push_items * sizeof(struct btrfs_key_ptr)); |
79f95c82 | 2860 | |
5f39d397 CM |
2861 | btrfs_set_header_nritems(src, src_nritems - push_items); |
2862 | btrfs_set_header_nritems(dst, dst_nritems + push_items); | |
79f95c82 | 2863 | |
5f39d397 CM |
2864 | btrfs_mark_buffer_dirty(src); |
2865 | btrfs_mark_buffer_dirty(dst); | |
31840ae1 | 2866 | |
aa5d6bed | 2867 | return ret; |
be0e5c09 CM |
2868 | } |
2869 | ||
97571fd0 CM |
2870 | /* |
2871 | * helper function to insert a new root level in the tree. | |
2872 | * A new node is allocated, and a single item is inserted to | |
2873 | * point to the existing root | |
aa5d6bed CM |
2874 | * |
2875 | * returns zero on success or < 0 on failure. | |
97571fd0 | 2876 | */ |
d397712b | 2877 | static noinline int insert_new_root(struct btrfs_trans_handle *trans, |
5f39d397 CM |
2878 | struct btrfs_root *root, |
2879 | struct btrfs_path *path, int level) | |
5c680ed6 | 2880 | { |
7bb86316 | 2881 | u64 lower_gen; |
5f39d397 CM |
2882 | struct extent_buffer *lower; |
2883 | struct extent_buffer *c; | |
925baedd | 2884 | struct extent_buffer *old; |
5f39d397 | 2885 | struct btrfs_disk_key lower_key; |
5c680ed6 CM |
2886 | |
2887 | BUG_ON(path->nodes[level]); | |
2888 | BUG_ON(path->nodes[level-1] != root->node); | |
2889 | ||
7bb86316 CM |
2890 | lower = path->nodes[level-1]; |
2891 | if (level == 1) | |
2892 | btrfs_item_key(lower, &lower_key, 0); | |
2893 | else | |
2894 | btrfs_node_key(lower, &lower_key, 0); | |
2895 | ||
31840ae1 | 2896 | c = btrfs_alloc_free_block(trans, root, root->nodesize, 0, |
5d4f98a2 | 2897 | root->root_key.objectid, &lower_key, |
5581a51a | 2898 | level, root->node->start, 0); |
5f39d397 CM |
2899 | if (IS_ERR(c)) |
2900 | return PTR_ERR(c); | |
925baedd | 2901 | |
f0486c68 YZ |
2902 | root_add_used(root, root->nodesize); |
2903 | ||
5d4f98a2 | 2904 | memset_extent_buffer(c, 0, 0, sizeof(struct btrfs_header)); |
5f39d397 CM |
2905 | btrfs_set_header_nritems(c, 1); |
2906 | btrfs_set_header_level(c, level); | |
db94535d | 2907 | btrfs_set_header_bytenr(c, c->start); |
5f39d397 | 2908 | btrfs_set_header_generation(c, trans->transid); |
5d4f98a2 | 2909 | btrfs_set_header_backref_rev(c, BTRFS_MIXED_BACKREF_REV); |
5f39d397 | 2910 | btrfs_set_header_owner(c, root->root_key.objectid); |
5f39d397 CM |
2911 | |
2912 | write_extent_buffer(c, root->fs_info->fsid, | |
2913 | (unsigned long)btrfs_header_fsid(c), | |
2914 | BTRFS_FSID_SIZE); | |
e17cade2 CM |
2915 | |
2916 | write_extent_buffer(c, root->fs_info->chunk_tree_uuid, | |
2917 | (unsigned long)btrfs_header_chunk_tree_uuid(c), | |
2918 | BTRFS_UUID_SIZE); | |
2919 | ||
5f39d397 | 2920 | btrfs_set_node_key(c, &lower_key, 0); |
db94535d | 2921 | btrfs_set_node_blockptr(c, 0, lower->start); |
7bb86316 | 2922 | lower_gen = btrfs_header_generation(lower); |
31840ae1 | 2923 | WARN_ON(lower_gen != trans->transid); |
7bb86316 CM |
2924 | |
2925 | btrfs_set_node_ptr_generation(c, 0, lower_gen); | |
d5719762 | 2926 | |
5f39d397 | 2927 | btrfs_mark_buffer_dirty(c); |
d5719762 | 2928 | |
925baedd | 2929 | old = root->node; |
f230475e | 2930 | tree_mod_log_set_root_pointer(root, c); |
240f62c8 | 2931 | rcu_assign_pointer(root->node, c); |
925baedd CM |
2932 | |
2933 | /* the super has an extra ref to root->node */ | |
2934 | free_extent_buffer(old); | |
2935 | ||
0b86a832 | 2936 | add_root_to_dirty_list(root); |
5f39d397 CM |
2937 | extent_buffer_get(c); |
2938 | path->nodes[level] = c; | |
bd681513 | 2939 | path->locks[level] = BTRFS_WRITE_LOCK; |
5c680ed6 CM |
2940 | path->slots[level] = 0; |
2941 | return 0; | |
2942 | } | |
2943 | ||
74123bd7 CM |
2944 | /* |
2945 | * worker function to insert a single pointer in a node. | |
2946 | * the node should have enough room for the pointer already | |
97571fd0 | 2947 | * |
74123bd7 CM |
2948 | * slot and level indicate where you want the key to go, and |
2949 | * blocknr is the block the key points to. | |
2950 | */ | |
143bede5 JM |
2951 | static void insert_ptr(struct btrfs_trans_handle *trans, |
2952 | struct btrfs_root *root, struct btrfs_path *path, | |
2953 | struct btrfs_disk_key *key, u64 bytenr, | |
f3ea38da | 2954 | int slot, int level, int tree_mod_log) |
74123bd7 | 2955 | { |
5f39d397 | 2956 | struct extent_buffer *lower; |
74123bd7 | 2957 | int nritems; |
f3ea38da | 2958 | int ret; |
5c680ed6 CM |
2959 | |
2960 | BUG_ON(!path->nodes[level]); | |
f0486c68 | 2961 | btrfs_assert_tree_locked(path->nodes[level]); |
5f39d397 CM |
2962 | lower = path->nodes[level]; |
2963 | nritems = btrfs_header_nritems(lower); | |
c293498b | 2964 | BUG_ON(slot > nritems); |
143bede5 | 2965 | BUG_ON(nritems == BTRFS_NODEPTRS_PER_BLOCK(root)); |
74123bd7 | 2966 | if (slot != nritems) { |
f3ea38da JS |
2967 | if (tree_mod_log && level) |
2968 | tree_mod_log_eb_move(root->fs_info, lower, slot + 1, | |
2969 | slot, nritems - slot); | |
5f39d397 CM |
2970 | memmove_extent_buffer(lower, |
2971 | btrfs_node_key_ptr_offset(slot + 1), | |
2972 | btrfs_node_key_ptr_offset(slot), | |
d6025579 | 2973 | (nritems - slot) * sizeof(struct btrfs_key_ptr)); |
74123bd7 | 2974 | } |
f3ea38da JS |
2975 | if (tree_mod_log && level) { |
2976 | ret = tree_mod_log_insert_key(root->fs_info, lower, slot, | |
2977 | MOD_LOG_KEY_ADD); | |
2978 | BUG_ON(ret < 0); | |
2979 | } | |
5f39d397 | 2980 | btrfs_set_node_key(lower, key, slot); |
db94535d | 2981 | btrfs_set_node_blockptr(lower, slot, bytenr); |
74493f7a CM |
2982 | WARN_ON(trans->transid == 0); |
2983 | btrfs_set_node_ptr_generation(lower, slot, trans->transid); | |
5f39d397 CM |
2984 | btrfs_set_header_nritems(lower, nritems + 1); |
2985 | btrfs_mark_buffer_dirty(lower); | |
74123bd7 CM |
2986 | } |
2987 | ||
97571fd0 CM |
2988 | /* |
2989 | * split the node at the specified level in path in two. | |
2990 | * The path is corrected to point to the appropriate node after the split | |
2991 | * | |
2992 | * Before splitting this tries to make some room in the node by pushing | |
2993 | * left and right, if either one works, it returns right away. | |
aa5d6bed CM |
2994 | * |
2995 | * returns 0 on success and < 0 on failure | |
97571fd0 | 2996 | */ |
e02119d5 CM |
2997 | static noinline int split_node(struct btrfs_trans_handle *trans, |
2998 | struct btrfs_root *root, | |
2999 | struct btrfs_path *path, int level) | |
be0e5c09 | 3000 | { |
5f39d397 CM |
3001 | struct extent_buffer *c; |
3002 | struct extent_buffer *split; | |
3003 | struct btrfs_disk_key disk_key; | |
be0e5c09 | 3004 | int mid; |
5c680ed6 | 3005 | int ret; |
7518a238 | 3006 | u32 c_nritems; |
eb60ceac | 3007 | |
5f39d397 | 3008 | c = path->nodes[level]; |
7bb86316 | 3009 | WARN_ON(btrfs_header_generation(c) != trans->transid); |
5f39d397 | 3010 | if (c == root->node) { |
5c680ed6 | 3011 | /* trying to split the root, lets make a new one */ |
e089f05c | 3012 | ret = insert_new_root(trans, root, path, level + 1); |
5c680ed6 CM |
3013 | if (ret) |
3014 | return ret; | |
b3612421 | 3015 | } else { |
e66f709b | 3016 | ret = push_nodes_for_insert(trans, root, path, level); |
5f39d397 CM |
3017 | c = path->nodes[level]; |
3018 | if (!ret && btrfs_header_nritems(c) < | |
c448acf0 | 3019 | BTRFS_NODEPTRS_PER_BLOCK(root) - 3) |
e66f709b | 3020 | return 0; |
54aa1f4d CM |
3021 | if (ret < 0) |
3022 | return ret; | |
be0e5c09 | 3023 | } |
e66f709b | 3024 | |
5f39d397 | 3025 | c_nritems = btrfs_header_nritems(c); |
5d4f98a2 YZ |
3026 | mid = (c_nritems + 1) / 2; |
3027 | btrfs_node_key(c, &disk_key, mid); | |
7bb86316 | 3028 | |
5d4f98a2 | 3029 | split = btrfs_alloc_free_block(trans, root, root->nodesize, 0, |
31840ae1 | 3030 | root->root_key.objectid, |
5581a51a | 3031 | &disk_key, level, c->start, 0); |
5f39d397 CM |
3032 | if (IS_ERR(split)) |
3033 | return PTR_ERR(split); | |
3034 | ||
f0486c68 YZ |
3035 | root_add_used(root, root->nodesize); |
3036 | ||
5d4f98a2 | 3037 | memset_extent_buffer(split, 0, 0, sizeof(struct btrfs_header)); |
5f39d397 | 3038 | btrfs_set_header_level(split, btrfs_header_level(c)); |
db94535d | 3039 | btrfs_set_header_bytenr(split, split->start); |
5f39d397 | 3040 | btrfs_set_header_generation(split, trans->transid); |
5d4f98a2 | 3041 | btrfs_set_header_backref_rev(split, BTRFS_MIXED_BACKREF_REV); |
5f39d397 CM |
3042 | btrfs_set_header_owner(split, root->root_key.objectid); |
3043 | write_extent_buffer(split, root->fs_info->fsid, | |
3044 | (unsigned long)btrfs_header_fsid(split), | |
3045 | BTRFS_FSID_SIZE); | |
e17cade2 CM |
3046 | write_extent_buffer(split, root->fs_info->chunk_tree_uuid, |
3047 | (unsigned long)btrfs_header_chunk_tree_uuid(split), | |
3048 | BTRFS_UUID_SIZE); | |
54aa1f4d | 3049 | |
f230475e | 3050 | tree_mod_log_eb_copy(root->fs_info, split, c, 0, mid, c_nritems - mid); |
5f39d397 CM |
3051 | copy_extent_buffer(split, c, |
3052 | btrfs_node_key_ptr_offset(0), | |
3053 | btrfs_node_key_ptr_offset(mid), | |
3054 | (c_nritems - mid) * sizeof(struct btrfs_key_ptr)); | |
3055 | btrfs_set_header_nritems(split, c_nritems - mid); | |
3056 | btrfs_set_header_nritems(c, mid); | |
aa5d6bed CM |
3057 | ret = 0; |
3058 | ||
5f39d397 CM |
3059 | btrfs_mark_buffer_dirty(c); |
3060 | btrfs_mark_buffer_dirty(split); | |
3061 | ||
143bede5 | 3062 | insert_ptr(trans, root, path, &disk_key, split->start, |
f3ea38da | 3063 | path->slots[level + 1] + 1, level + 1, 1); |
aa5d6bed | 3064 | |
5de08d7d | 3065 | if (path->slots[level] >= mid) { |
5c680ed6 | 3066 | path->slots[level] -= mid; |
925baedd | 3067 | btrfs_tree_unlock(c); |
5f39d397 CM |
3068 | free_extent_buffer(c); |
3069 | path->nodes[level] = split; | |
5c680ed6 CM |
3070 | path->slots[level + 1] += 1; |
3071 | } else { | |
925baedd | 3072 | btrfs_tree_unlock(split); |
5f39d397 | 3073 | free_extent_buffer(split); |
be0e5c09 | 3074 | } |
aa5d6bed | 3075 | return ret; |
be0e5c09 CM |
3076 | } |
3077 | ||
74123bd7 CM |
3078 | /* |
3079 | * how many bytes are required to store the items in a leaf. start | |
3080 | * and nr indicate which items in the leaf to check. This totals up the | |
3081 | * space used both by the item structs and the item data | |
3082 | */ | |
5f39d397 | 3083 | static int leaf_space_used(struct extent_buffer *l, int start, int nr) |
be0e5c09 CM |
3084 | { |
3085 | int data_len; | |
5f39d397 | 3086 | int nritems = btrfs_header_nritems(l); |
d4dbff95 | 3087 | int end = min(nritems, start + nr) - 1; |
be0e5c09 CM |
3088 | |
3089 | if (!nr) | |
3090 | return 0; | |
5f39d397 CM |
3091 | data_len = btrfs_item_end_nr(l, start); |
3092 | data_len = data_len - btrfs_item_offset_nr(l, end); | |
0783fcfc | 3093 | data_len += sizeof(struct btrfs_item) * nr; |
d4dbff95 | 3094 | WARN_ON(data_len < 0); |
be0e5c09 CM |
3095 | return data_len; |
3096 | } | |
3097 | ||
d4dbff95 CM |
3098 | /* |
3099 | * The space between the end of the leaf items and | |
3100 | * the start of the leaf data. IOW, how much room | |
3101 | * the leaf has left for both items and data | |
3102 | */ | |
d397712b | 3103 | noinline int btrfs_leaf_free_space(struct btrfs_root *root, |
e02119d5 | 3104 | struct extent_buffer *leaf) |
d4dbff95 | 3105 | { |
5f39d397 CM |
3106 | int nritems = btrfs_header_nritems(leaf); |
3107 | int ret; | |
3108 | ret = BTRFS_LEAF_DATA_SIZE(root) - leaf_space_used(leaf, 0, nritems); | |
3109 | if (ret < 0) { | |
d397712b CM |
3110 | printk(KERN_CRIT "leaf free space ret %d, leaf data size %lu, " |
3111 | "used %d nritems %d\n", | |
ae2f5411 | 3112 | ret, (unsigned long) BTRFS_LEAF_DATA_SIZE(root), |
5f39d397 CM |
3113 | leaf_space_used(leaf, 0, nritems), nritems); |
3114 | } | |
3115 | return ret; | |
d4dbff95 CM |
3116 | } |
3117 | ||
99d8f83c CM |
3118 | /* |
3119 | * min slot controls the lowest index we're willing to push to the | |
3120 | * right. We'll push up to and including min_slot, but no lower | |
3121 | */ | |
44871b1b CM |
3122 | static noinline int __push_leaf_right(struct btrfs_trans_handle *trans, |
3123 | struct btrfs_root *root, | |
3124 | struct btrfs_path *path, | |
3125 | int data_size, int empty, | |
3126 | struct extent_buffer *right, | |
99d8f83c CM |
3127 | int free_space, u32 left_nritems, |
3128 | u32 min_slot) | |
00ec4c51 | 3129 | { |
5f39d397 | 3130 | struct extent_buffer *left = path->nodes[0]; |
44871b1b | 3131 | struct extent_buffer *upper = path->nodes[1]; |
cfed81a0 | 3132 | struct btrfs_map_token token; |
5f39d397 | 3133 | struct btrfs_disk_key disk_key; |
00ec4c51 | 3134 | int slot; |
34a38218 | 3135 | u32 i; |
00ec4c51 CM |
3136 | int push_space = 0; |
3137 | int push_items = 0; | |
0783fcfc | 3138 | struct btrfs_item *item; |
34a38218 | 3139 | u32 nr; |
7518a238 | 3140 | u32 right_nritems; |
5f39d397 | 3141 | u32 data_end; |
db94535d | 3142 | u32 this_item_size; |
00ec4c51 | 3143 | |
cfed81a0 CM |
3144 | btrfs_init_map_token(&token); |
3145 | ||
34a38218 CM |
3146 | if (empty) |
3147 | nr = 0; | |
3148 | else | |
99d8f83c | 3149 | nr = max_t(u32, 1, min_slot); |
34a38218 | 3150 | |
31840ae1 | 3151 | if (path->slots[0] >= left_nritems) |
87b29b20 | 3152 | push_space += data_size; |
31840ae1 | 3153 | |
44871b1b | 3154 | slot = path->slots[1]; |
34a38218 CM |
3155 | i = left_nritems - 1; |
3156 | while (i >= nr) { | |
5f39d397 | 3157 | item = btrfs_item_nr(left, i); |
db94535d | 3158 | |
31840ae1 ZY |
3159 | if (!empty && push_items > 0) { |
3160 | if (path->slots[0] > i) | |
3161 | break; | |
3162 | if (path->slots[0] == i) { | |
3163 | int space = btrfs_leaf_free_space(root, left); | |
3164 | if (space + push_space * 2 > free_space) | |
3165 | break; | |
3166 | } | |
3167 | } | |
3168 | ||
00ec4c51 | 3169 | if (path->slots[0] == i) |
87b29b20 | 3170 | push_space += data_size; |
db94535d | 3171 | |
db94535d CM |
3172 | this_item_size = btrfs_item_size(left, item); |
3173 | if (this_item_size + sizeof(*item) + push_space > free_space) | |
00ec4c51 | 3174 | break; |
31840ae1 | 3175 | |
00ec4c51 | 3176 | push_items++; |
db94535d | 3177 | push_space += this_item_size + sizeof(*item); |
34a38218 CM |
3178 | if (i == 0) |
3179 | break; | |
3180 | i--; | |
db94535d | 3181 | } |
5f39d397 | 3182 | |
925baedd CM |
3183 | if (push_items == 0) |
3184 | goto out_unlock; | |
5f39d397 | 3185 | |
34a38218 | 3186 | if (!empty && push_items == left_nritems) |
a429e513 | 3187 | WARN_ON(1); |
5f39d397 | 3188 | |
00ec4c51 | 3189 | /* push left to right */ |
5f39d397 | 3190 | right_nritems = btrfs_header_nritems(right); |
34a38218 | 3191 | |
5f39d397 | 3192 | push_space = btrfs_item_end_nr(left, left_nritems - push_items); |
123abc88 | 3193 | push_space -= leaf_data_end(root, left); |
5f39d397 | 3194 | |
00ec4c51 | 3195 | /* make room in the right data area */ |
5f39d397 CM |
3196 | data_end = leaf_data_end(root, right); |
3197 | memmove_extent_buffer(right, | |
3198 | btrfs_leaf_data(right) + data_end - push_space, | |
3199 | btrfs_leaf_data(right) + data_end, | |
3200 | BTRFS_LEAF_DATA_SIZE(root) - data_end); | |
3201 | ||
00ec4c51 | 3202 | /* copy from the left data area */ |
5f39d397 | 3203 | copy_extent_buffer(right, left, btrfs_leaf_data(right) + |
d6025579 CM |
3204 | BTRFS_LEAF_DATA_SIZE(root) - push_space, |
3205 | btrfs_leaf_data(left) + leaf_data_end(root, left), | |
3206 | push_space); | |
5f39d397 CM |
3207 | |
3208 | memmove_extent_buffer(right, btrfs_item_nr_offset(push_items), | |
3209 | btrfs_item_nr_offset(0), | |
3210 | right_nritems * sizeof(struct btrfs_item)); | |
3211 | ||
00ec4c51 | 3212 | /* copy the items from left to right */ |
5f39d397 CM |
3213 | copy_extent_buffer(right, left, btrfs_item_nr_offset(0), |
3214 | btrfs_item_nr_offset(left_nritems - push_items), | |
3215 | push_items * sizeof(struct btrfs_item)); | |
00ec4c51 CM |
3216 | |
3217 | /* update the item pointers */ | |
7518a238 | 3218 | right_nritems += push_items; |
5f39d397 | 3219 | btrfs_set_header_nritems(right, right_nritems); |
123abc88 | 3220 | push_space = BTRFS_LEAF_DATA_SIZE(root); |
7518a238 | 3221 | for (i = 0; i < right_nritems; i++) { |
5f39d397 | 3222 | item = btrfs_item_nr(right, i); |
cfed81a0 CM |
3223 | push_space -= btrfs_token_item_size(right, item, &token); |
3224 | btrfs_set_token_item_offset(right, item, push_space, &token); | |
db94535d CM |
3225 | } |
3226 | ||
7518a238 | 3227 | left_nritems -= push_items; |
5f39d397 | 3228 | btrfs_set_header_nritems(left, left_nritems); |
00ec4c51 | 3229 | |
34a38218 CM |
3230 | if (left_nritems) |
3231 | btrfs_mark_buffer_dirty(left); | |
f0486c68 YZ |
3232 | else |
3233 | clean_tree_block(trans, root, left); | |
3234 | ||
5f39d397 | 3235 | btrfs_mark_buffer_dirty(right); |
a429e513 | 3236 | |
5f39d397 CM |
3237 | btrfs_item_key(right, &disk_key, 0); |
3238 | btrfs_set_node_key(upper, &disk_key, slot + 1); | |
d6025579 | 3239 | btrfs_mark_buffer_dirty(upper); |
02217ed2 | 3240 | |
00ec4c51 | 3241 | /* then fixup the leaf pointer in the path */ |
7518a238 CM |
3242 | if (path->slots[0] >= left_nritems) { |
3243 | path->slots[0] -= left_nritems; | |
925baedd CM |
3244 | if (btrfs_header_nritems(path->nodes[0]) == 0) |
3245 | clean_tree_block(trans, root, path->nodes[0]); | |
3246 | btrfs_tree_unlock(path->nodes[0]); | |
5f39d397 CM |
3247 | free_extent_buffer(path->nodes[0]); |
3248 | path->nodes[0] = right; | |
00ec4c51 CM |
3249 | path->slots[1] += 1; |
3250 | } else { | |
925baedd | 3251 | btrfs_tree_unlock(right); |
5f39d397 | 3252 | free_extent_buffer(right); |
00ec4c51 CM |
3253 | } |
3254 | return 0; | |
925baedd CM |
3255 | |
3256 | out_unlock: | |
3257 | btrfs_tree_unlock(right); | |
3258 | free_extent_buffer(right); | |
3259 | return 1; | |
00ec4c51 | 3260 | } |
925baedd | 3261 | |
44871b1b CM |
3262 | /* |
3263 | * push some data in the path leaf to the right, trying to free up at | |
3264 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
3265 | * | |
3266 | * returns 1 if the push failed because the other node didn't have enough | |
3267 | * room, 0 if everything worked out and < 0 if there were major errors. | |
99d8f83c CM |
3268 | * |
3269 | * this will push starting from min_slot to the end of the leaf. It won't | |
3270 | * push any slot lower than min_slot | |
44871b1b CM |
3271 | */ |
3272 | static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root | |
99d8f83c CM |
3273 | *root, struct btrfs_path *path, |
3274 | int min_data_size, int data_size, | |
3275 | int empty, u32 min_slot) | |
44871b1b CM |
3276 | { |
3277 | struct extent_buffer *left = path->nodes[0]; | |
3278 | struct extent_buffer *right; | |
3279 | struct extent_buffer *upper; | |
3280 | int slot; | |
3281 | int free_space; | |
3282 | u32 left_nritems; | |
3283 | int ret; | |
3284 | ||
3285 | if (!path->nodes[1]) | |
3286 | return 1; | |
3287 | ||
3288 | slot = path->slots[1]; | |
3289 | upper = path->nodes[1]; | |
3290 | if (slot >= btrfs_header_nritems(upper) - 1) | |
3291 | return 1; | |
3292 | ||
3293 | btrfs_assert_tree_locked(path->nodes[1]); | |
3294 | ||
3295 | right = read_node_slot(root, upper, slot + 1); | |
91ca338d TI |
3296 | if (right == NULL) |
3297 | return 1; | |
3298 | ||
44871b1b CM |
3299 | btrfs_tree_lock(right); |
3300 | btrfs_set_lock_blocking(right); | |
3301 | ||
3302 | free_space = btrfs_leaf_free_space(root, right); | |
3303 | if (free_space < data_size) | |
3304 | goto out_unlock; | |
3305 | ||
3306 | /* cow and double check */ | |
3307 | ret = btrfs_cow_block(trans, root, right, upper, | |
3308 | slot + 1, &right); | |
3309 | if (ret) | |
3310 | goto out_unlock; | |
3311 | ||
3312 | free_space = btrfs_leaf_free_space(root, right); | |
3313 | if (free_space < data_size) | |
3314 | goto out_unlock; | |
3315 | ||
3316 | left_nritems = btrfs_header_nritems(left); | |
3317 | if (left_nritems == 0) | |
3318 | goto out_unlock; | |
3319 | ||
99d8f83c CM |
3320 | return __push_leaf_right(trans, root, path, min_data_size, empty, |
3321 | right, free_space, left_nritems, min_slot); | |
44871b1b CM |
3322 | out_unlock: |
3323 | btrfs_tree_unlock(right); | |
3324 | free_extent_buffer(right); | |
3325 | return 1; | |
3326 | } | |
3327 | ||
74123bd7 CM |
3328 | /* |
3329 | * push some data in the path leaf to the left, trying to free up at | |
3330 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
99d8f83c CM |
3331 | * |
3332 | * max_slot can put a limit on how far into the leaf we'll push items. The | |
3333 | * item at 'max_slot' won't be touched. Use (u32)-1 to make us do all the | |
3334 | * items | |
74123bd7 | 3335 | */ |
44871b1b CM |
3336 | static noinline int __push_leaf_left(struct btrfs_trans_handle *trans, |
3337 | struct btrfs_root *root, | |
3338 | struct btrfs_path *path, int data_size, | |
3339 | int empty, struct extent_buffer *left, | |
99d8f83c CM |
3340 | int free_space, u32 right_nritems, |
3341 | u32 max_slot) | |
be0e5c09 | 3342 | { |
5f39d397 CM |
3343 | struct btrfs_disk_key disk_key; |
3344 | struct extent_buffer *right = path->nodes[0]; | |
be0e5c09 | 3345 | int i; |
be0e5c09 CM |
3346 | int push_space = 0; |
3347 | int push_items = 0; | |
0783fcfc | 3348 | struct btrfs_item *item; |
7518a238 | 3349 | u32 old_left_nritems; |
34a38218 | 3350 | u32 nr; |
aa5d6bed | 3351 | int ret = 0; |
db94535d CM |
3352 | u32 this_item_size; |
3353 | u32 old_left_item_size; | |
cfed81a0 CM |
3354 | struct btrfs_map_token token; |
3355 | ||
3356 | btrfs_init_map_token(&token); | |
be0e5c09 | 3357 | |
34a38218 | 3358 | if (empty) |
99d8f83c | 3359 | nr = min(right_nritems, max_slot); |
34a38218 | 3360 | else |
99d8f83c | 3361 | nr = min(right_nritems - 1, max_slot); |
34a38218 CM |
3362 | |
3363 | for (i = 0; i < nr; i++) { | |
5f39d397 | 3364 | item = btrfs_item_nr(right, i); |
db94535d | 3365 | |
31840ae1 ZY |
3366 | if (!empty && push_items > 0) { |
3367 | if (path->slots[0] < i) | |
3368 | break; | |
3369 | if (path->slots[0] == i) { | |
3370 | int space = btrfs_leaf_free_space(root, right); | |
3371 | if (space + push_space * 2 > free_space) | |
3372 | break; | |
3373 | } | |
3374 | } | |
3375 | ||
be0e5c09 | 3376 | if (path->slots[0] == i) |
87b29b20 | 3377 | push_space += data_size; |
db94535d CM |
3378 | |
3379 | this_item_size = btrfs_item_size(right, item); | |
3380 | if (this_item_size + sizeof(*item) + push_space > free_space) | |
be0e5c09 | 3381 | break; |
db94535d | 3382 | |
be0e5c09 | 3383 | push_items++; |
db94535d CM |
3384 | push_space += this_item_size + sizeof(*item); |
3385 | } | |
3386 | ||
be0e5c09 | 3387 | if (push_items == 0) { |
925baedd CM |
3388 | ret = 1; |
3389 | goto out; | |
be0e5c09 | 3390 | } |
34a38218 | 3391 | if (!empty && push_items == btrfs_header_nritems(right)) |
a429e513 | 3392 | WARN_ON(1); |
5f39d397 | 3393 | |
be0e5c09 | 3394 | /* push data from right to left */ |
5f39d397 CM |
3395 | copy_extent_buffer(left, right, |
3396 | btrfs_item_nr_offset(btrfs_header_nritems(left)), | |
3397 | btrfs_item_nr_offset(0), | |
3398 | push_items * sizeof(struct btrfs_item)); | |
3399 | ||
123abc88 | 3400 | push_space = BTRFS_LEAF_DATA_SIZE(root) - |
d397712b | 3401 | btrfs_item_offset_nr(right, push_items - 1); |
5f39d397 CM |
3402 | |
3403 | copy_extent_buffer(left, right, btrfs_leaf_data(left) + | |
d6025579 CM |
3404 | leaf_data_end(root, left) - push_space, |
3405 | btrfs_leaf_data(right) + | |
5f39d397 | 3406 | btrfs_item_offset_nr(right, push_items - 1), |
d6025579 | 3407 | push_space); |
5f39d397 | 3408 | old_left_nritems = btrfs_header_nritems(left); |
87b29b20 | 3409 | BUG_ON(old_left_nritems <= 0); |
eb60ceac | 3410 | |
db94535d | 3411 | old_left_item_size = btrfs_item_offset_nr(left, old_left_nritems - 1); |
0783fcfc | 3412 | for (i = old_left_nritems; i < old_left_nritems + push_items; i++) { |
5f39d397 | 3413 | u32 ioff; |
db94535d | 3414 | |
5f39d397 | 3415 | item = btrfs_item_nr(left, i); |
db94535d | 3416 | |
cfed81a0 CM |
3417 | ioff = btrfs_token_item_offset(left, item, &token); |
3418 | btrfs_set_token_item_offset(left, item, | |
3419 | ioff - (BTRFS_LEAF_DATA_SIZE(root) - old_left_item_size), | |
3420 | &token); | |
be0e5c09 | 3421 | } |
5f39d397 | 3422 | btrfs_set_header_nritems(left, old_left_nritems + push_items); |
be0e5c09 CM |
3423 | |
3424 | /* fixup right node */ | |
34a38218 | 3425 | if (push_items > right_nritems) { |
d397712b CM |
3426 | printk(KERN_CRIT "push items %d nr %u\n", push_items, |
3427 | right_nritems); | |
34a38218 CM |
3428 | WARN_ON(1); |
3429 | } | |
3430 | ||
3431 | if (push_items < right_nritems) { | |
3432 | push_space = btrfs_item_offset_nr(right, push_items - 1) - | |
3433 | leaf_data_end(root, right); | |
3434 | memmove_extent_buffer(right, btrfs_leaf_data(right) + | |
3435 | BTRFS_LEAF_DATA_SIZE(root) - push_space, | |
3436 | btrfs_leaf_data(right) + | |
3437 | leaf_data_end(root, right), push_space); | |
3438 | ||
3439 | memmove_extent_buffer(right, btrfs_item_nr_offset(0), | |
5f39d397 CM |
3440 | btrfs_item_nr_offset(push_items), |
3441 | (btrfs_header_nritems(right) - push_items) * | |
3442 | sizeof(struct btrfs_item)); | |
34a38218 | 3443 | } |
eef1c494 Y |
3444 | right_nritems -= push_items; |
3445 | btrfs_set_header_nritems(right, right_nritems); | |
123abc88 | 3446 | push_space = BTRFS_LEAF_DATA_SIZE(root); |
5f39d397 CM |
3447 | for (i = 0; i < right_nritems; i++) { |
3448 | item = btrfs_item_nr(right, i); | |
db94535d | 3449 | |
cfed81a0 CM |
3450 | push_space = push_space - btrfs_token_item_size(right, |
3451 | item, &token); | |
3452 | btrfs_set_token_item_offset(right, item, push_space, &token); | |
db94535d | 3453 | } |
eb60ceac | 3454 | |
5f39d397 | 3455 | btrfs_mark_buffer_dirty(left); |
34a38218 CM |
3456 | if (right_nritems) |
3457 | btrfs_mark_buffer_dirty(right); | |
f0486c68 YZ |
3458 | else |
3459 | clean_tree_block(trans, root, right); | |
098f59c2 | 3460 | |
5f39d397 | 3461 | btrfs_item_key(right, &disk_key, 0); |
143bede5 | 3462 | fixup_low_keys(trans, root, path, &disk_key, 1); |
be0e5c09 CM |
3463 | |
3464 | /* then fixup the leaf pointer in the path */ | |
3465 | if (path->slots[0] < push_items) { | |
3466 | path->slots[0] += old_left_nritems; | |
925baedd | 3467 | btrfs_tree_unlock(path->nodes[0]); |
5f39d397 CM |
3468 | free_extent_buffer(path->nodes[0]); |
3469 | path->nodes[0] = left; | |
be0e5c09 CM |
3470 | path->slots[1] -= 1; |
3471 | } else { | |
925baedd | 3472 | btrfs_tree_unlock(left); |
5f39d397 | 3473 | free_extent_buffer(left); |
be0e5c09 CM |
3474 | path->slots[0] -= push_items; |
3475 | } | |
eb60ceac | 3476 | BUG_ON(path->slots[0] < 0); |
aa5d6bed | 3477 | return ret; |
925baedd CM |
3478 | out: |
3479 | btrfs_tree_unlock(left); | |
3480 | free_extent_buffer(left); | |
3481 | return ret; | |
be0e5c09 CM |
3482 | } |
3483 | ||
44871b1b CM |
3484 | /* |
3485 | * push some data in the path leaf to the left, trying to free up at | |
3486 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
99d8f83c CM |
3487 | * |
3488 | * max_slot can put a limit on how far into the leaf we'll push items. The | |
3489 | * item at 'max_slot' won't be touched. Use (u32)-1 to make us push all the | |
3490 | * items | |
44871b1b CM |
3491 | */ |
3492 | static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root | |
99d8f83c CM |
3493 | *root, struct btrfs_path *path, int min_data_size, |
3494 | int data_size, int empty, u32 max_slot) | |
44871b1b CM |
3495 | { |
3496 | struct extent_buffer *right = path->nodes[0]; | |
3497 | struct extent_buffer *left; | |
3498 | int slot; | |
3499 | int free_space; | |
3500 | u32 right_nritems; | |
3501 | int ret = 0; | |
3502 | ||
3503 | slot = path->slots[1]; | |
3504 | if (slot == 0) | |
3505 | return 1; | |
3506 | if (!path->nodes[1]) | |
3507 | return 1; | |
3508 | ||
3509 | right_nritems = btrfs_header_nritems(right); | |
3510 | if (right_nritems == 0) | |
3511 | return 1; | |
3512 | ||
3513 | btrfs_assert_tree_locked(path->nodes[1]); | |
3514 | ||
3515 | left = read_node_slot(root, path->nodes[1], slot - 1); | |
91ca338d TI |
3516 | if (left == NULL) |
3517 | return 1; | |
3518 | ||
44871b1b CM |
3519 | btrfs_tree_lock(left); |
3520 | btrfs_set_lock_blocking(left); | |
3521 | ||
3522 | free_space = btrfs_leaf_free_space(root, left); | |
3523 | if (free_space < data_size) { | |
3524 | ret = 1; | |
3525 | goto out; | |
3526 | } | |
3527 | ||
3528 | /* cow and double check */ | |
3529 | ret = btrfs_cow_block(trans, root, left, | |
3530 | path->nodes[1], slot - 1, &left); | |
3531 | if (ret) { | |
3532 | /* we hit -ENOSPC, but it isn't fatal here */ | |
79787eaa JM |
3533 | if (ret == -ENOSPC) |
3534 | ret = 1; | |
44871b1b CM |
3535 | goto out; |
3536 | } | |
3537 | ||
3538 | free_space = btrfs_leaf_free_space(root, left); | |
3539 | if (free_space < data_size) { | |
3540 | ret = 1; | |
3541 | goto out; | |
3542 | } | |
3543 | ||
99d8f83c CM |
3544 | return __push_leaf_left(trans, root, path, min_data_size, |
3545 | empty, left, free_space, right_nritems, | |
3546 | max_slot); | |
44871b1b CM |
3547 | out: |
3548 | btrfs_tree_unlock(left); | |
3549 | free_extent_buffer(left); | |
3550 | return ret; | |
3551 | } | |
3552 | ||
3553 | /* | |
3554 | * split the path's leaf in two, making sure there is at least data_size | |
3555 | * available for the resulting leaf level of the path. | |
44871b1b | 3556 | */ |
143bede5 JM |
3557 | static noinline void copy_for_split(struct btrfs_trans_handle *trans, |
3558 | struct btrfs_root *root, | |
3559 | struct btrfs_path *path, | |
3560 | struct extent_buffer *l, | |
3561 | struct extent_buffer *right, | |
3562 | int slot, int mid, int nritems) | |
44871b1b CM |
3563 | { |
3564 | int data_copy_size; | |
3565 | int rt_data_off; | |
3566 | int i; | |
44871b1b | 3567 | struct btrfs_disk_key disk_key; |
cfed81a0 CM |
3568 | struct btrfs_map_token token; |
3569 | ||
3570 | btrfs_init_map_token(&token); | |
44871b1b CM |
3571 | |
3572 | nritems = nritems - mid; | |
3573 | btrfs_set_header_nritems(right, nritems); | |
3574 | data_copy_size = btrfs_item_end_nr(l, mid) - leaf_data_end(root, l); | |
3575 | ||
3576 | copy_extent_buffer(right, l, btrfs_item_nr_offset(0), | |
3577 | btrfs_item_nr_offset(mid), | |
3578 | nritems * sizeof(struct btrfs_item)); | |
3579 | ||
3580 | copy_extent_buffer(right, l, | |
3581 | btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) - | |
3582 | data_copy_size, btrfs_leaf_data(l) + | |
3583 | leaf_data_end(root, l), data_copy_size); | |
3584 | ||
3585 | rt_data_off = BTRFS_LEAF_DATA_SIZE(root) - | |
3586 | btrfs_item_end_nr(l, mid); | |
3587 | ||
3588 | for (i = 0; i < nritems; i++) { | |
3589 | struct btrfs_item *item = btrfs_item_nr(right, i); | |
3590 | u32 ioff; | |
3591 | ||
cfed81a0 CM |
3592 | ioff = btrfs_token_item_offset(right, item, &token); |
3593 | btrfs_set_token_item_offset(right, item, | |
3594 | ioff + rt_data_off, &token); | |
44871b1b CM |
3595 | } |
3596 | ||
44871b1b | 3597 | btrfs_set_header_nritems(l, mid); |
44871b1b | 3598 | btrfs_item_key(right, &disk_key, 0); |
143bede5 | 3599 | insert_ptr(trans, root, path, &disk_key, right->start, |
f3ea38da | 3600 | path->slots[1] + 1, 1, 0); |
44871b1b CM |
3601 | |
3602 | btrfs_mark_buffer_dirty(right); | |
3603 | btrfs_mark_buffer_dirty(l); | |
3604 | BUG_ON(path->slots[0] != slot); | |
3605 | ||
44871b1b CM |
3606 | if (mid <= slot) { |
3607 | btrfs_tree_unlock(path->nodes[0]); | |
3608 | free_extent_buffer(path->nodes[0]); | |
3609 | path->nodes[0] = right; | |
3610 | path->slots[0] -= mid; | |
3611 | path->slots[1] += 1; | |
3612 | } else { | |
3613 | btrfs_tree_unlock(right); | |
3614 | free_extent_buffer(right); | |
3615 | } | |
3616 | ||
3617 | BUG_ON(path->slots[0] < 0); | |
44871b1b CM |
3618 | } |
3619 | ||
99d8f83c CM |
3620 | /* |
3621 | * double splits happen when we need to insert a big item in the middle | |
3622 | * of a leaf. A double split can leave us with 3 mostly empty leaves: | |
3623 | * leaf: [ slots 0 - N] [ our target ] [ N + 1 - total in leaf ] | |
3624 | * A B C | |
3625 | * | |
3626 | * We avoid this by trying to push the items on either side of our target | |
3627 | * into the adjacent leaves. If all goes well we can avoid the double split | |
3628 | * completely. | |
3629 | */ | |
3630 | static noinline int push_for_double_split(struct btrfs_trans_handle *trans, | |
3631 | struct btrfs_root *root, | |
3632 | struct btrfs_path *path, | |
3633 | int data_size) | |
3634 | { | |
3635 | int ret; | |
3636 | int progress = 0; | |
3637 | int slot; | |
3638 | u32 nritems; | |
3639 | ||
3640 | slot = path->slots[0]; | |
3641 | ||
3642 | /* | |
3643 | * try to push all the items after our slot into the | |
3644 | * right leaf | |
3645 | */ | |
3646 | ret = push_leaf_right(trans, root, path, 1, data_size, 0, slot); | |
3647 | if (ret < 0) | |
3648 | return ret; | |
3649 | ||
3650 | if (ret == 0) | |
3651 | progress++; | |
3652 | ||
3653 | nritems = btrfs_header_nritems(path->nodes[0]); | |
3654 | /* | |
3655 | * our goal is to get our slot at the start or end of a leaf. If | |
3656 | * we've done so we're done | |
3657 | */ | |
3658 | if (path->slots[0] == 0 || path->slots[0] == nritems) | |
3659 | return 0; | |
3660 | ||
3661 | if (btrfs_leaf_free_space(root, path->nodes[0]) >= data_size) | |
3662 | return 0; | |
3663 | ||
3664 | /* try to push all the items before our slot into the next leaf */ | |
3665 | slot = path->slots[0]; | |
3666 | ret = push_leaf_left(trans, root, path, 1, data_size, 0, slot); | |
3667 | if (ret < 0) | |
3668 | return ret; | |
3669 | ||
3670 | if (ret == 0) | |
3671 | progress++; | |
3672 | ||
3673 | if (progress) | |
3674 | return 0; | |
3675 | return 1; | |
3676 | } | |
3677 | ||
74123bd7 CM |
3678 | /* |
3679 | * split the path's leaf in two, making sure there is at least data_size | |
3680 | * available for the resulting leaf level of the path. | |
aa5d6bed CM |
3681 | * |
3682 | * returns 0 if all went well and < 0 on failure. | |
74123bd7 | 3683 | */ |
e02119d5 CM |
3684 | static noinline int split_leaf(struct btrfs_trans_handle *trans, |
3685 | struct btrfs_root *root, | |
3686 | struct btrfs_key *ins_key, | |
3687 | struct btrfs_path *path, int data_size, | |
3688 | int extend) | |
be0e5c09 | 3689 | { |
5d4f98a2 | 3690 | struct btrfs_disk_key disk_key; |
5f39d397 | 3691 | struct extent_buffer *l; |
7518a238 | 3692 | u32 nritems; |
eb60ceac CM |
3693 | int mid; |
3694 | int slot; | |
5f39d397 | 3695 | struct extent_buffer *right; |
d4dbff95 | 3696 | int ret = 0; |
aa5d6bed | 3697 | int wret; |
5d4f98a2 | 3698 | int split; |
cc0c5538 | 3699 | int num_doubles = 0; |
99d8f83c | 3700 | int tried_avoid_double = 0; |
aa5d6bed | 3701 | |
a5719521 YZ |
3702 | l = path->nodes[0]; |
3703 | slot = path->slots[0]; | |
3704 | if (extend && data_size + btrfs_item_size_nr(l, slot) + | |
3705 | sizeof(struct btrfs_item) > BTRFS_LEAF_DATA_SIZE(root)) | |
3706 | return -EOVERFLOW; | |
3707 | ||
40689478 | 3708 | /* first try to make some room by pushing left and right */ |
99d8f83c CM |
3709 | if (data_size) { |
3710 | wret = push_leaf_right(trans, root, path, data_size, | |
3711 | data_size, 0, 0); | |
d397712b | 3712 | if (wret < 0) |
eaee50e8 | 3713 | return wret; |
3685f791 | 3714 | if (wret) { |
99d8f83c CM |
3715 | wret = push_leaf_left(trans, root, path, data_size, |
3716 | data_size, 0, (u32)-1); | |
3685f791 CM |
3717 | if (wret < 0) |
3718 | return wret; | |
3719 | } | |
3720 | l = path->nodes[0]; | |
aa5d6bed | 3721 | |
3685f791 | 3722 | /* did the pushes work? */ |
87b29b20 | 3723 | if (btrfs_leaf_free_space(root, l) >= data_size) |
3685f791 | 3724 | return 0; |
3326d1b0 | 3725 | } |
aa5d6bed | 3726 | |
5c680ed6 | 3727 | if (!path->nodes[1]) { |
e089f05c | 3728 | ret = insert_new_root(trans, root, path, 1); |
5c680ed6 CM |
3729 | if (ret) |
3730 | return ret; | |
3731 | } | |
cc0c5538 | 3732 | again: |
5d4f98a2 | 3733 | split = 1; |
cc0c5538 | 3734 | l = path->nodes[0]; |
eb60ceac | 3735 | slot = path->slots[0]; |
5f39d397 | 3736 | nritems = btrfs_header_nritems(l); |
d397712b | 3737 | mid = (nritems + 1) / 2; |
54aa1f4d | 3738 | |
5d4f98a2 YZ |
3739 | if (mid <= slot) { |
3740 | if (nritems == 1 || | |
3741 | leaf_space_used(l, mid, nritems - mid) + data_size > | |
3742 | BTRFS_LEAF_DATA_SIZE(root)) { | |
3743 | if (slot >= nritems) { | |
3744 | split = 0; | |
3745 | } else { | |
3746 | mid = slot; | |
3747 | if (mid != nritems && | |
3748 | leaf_space_used(l, mid, nritems - mid) + | |
3749 | data_size > BTRFS_LEAF_DATA_SIZE(root)) { | |
99d8f83c CM |
3750 | if (data_size && !tried_avoid_double) |
3751 | goto push_for_double; | |
5d4f98a2 YZ |
3752 | split = 2; |
3753 | } | |
3754 | } | |
3755 | } | |
3756 | } else { | |
3757 | if (leaf_space_used(l, 0, mid) + data_size > | |
3758 | BTRFS_LEAF_DATA_SIZE(root)) { | |
3759 | if (!extend && data_size && slot == 0) { | |
3760 | split = 0; | |
3761 | } else if ((extend || !data_size) && slot == 0) { | |
3762 | mid = 1; | |
3763 | } else { | |
3764 | mid = slot; | |
3765 | if (mid != nritems && | |
3766 | leaf_space_used(l, mid, nritems - mid) + | |
3767 | data_size > BTRFS_LEAF_DATA_SIZE(root)) { | |
99d8f83c CM |
3768 | if (data_size && !tried_avoid_double) |
3769 | goto push_for_double; | |
5d4f98a2 YZ |
3770 | split = 2 ; |
3771 | } | |
3772 | } | |
3773 | } | |
3774 | } | |
3775 | ||
3776 | if (split == 0) | |
3777 | btrfs_cpu_key_to_disk(&disk_key, ins_key); | |
3778 | else | |
3779 | btrfs_item_key(l, &disk_key, mid); | |
3780 | ||
3781 | right = btrfs_alloc_free_block(trans, root, root->leafsize, 0, | |
31840ae1 | 3782 | root->root_key.objectid, |
5581a51a | 3783 | &disk_key, 0, l->start, 0); |
f0486c68 | 3784 | if (IS_ERR(right)) |
5f39d397 | 3785 | return PTR_ERR(right); |
f0486c68 YZ |
3786 | |
3787 | root_add_used(root, root->leafsize); | |
5f39d397 CM |
3788 | |
3789 | memset_extent_buffer(right, 0, 0, sizeof(struct btrfs_header)); | |
db94535d | 3790 | btrfs_set_header_bytenr(right, right->start); |
5f39d397 | 3791 | btrfs_set_header_generation(right, trans->transid); |
5d4f98a2 | 3792 | btrfs_set_header_backref_rev(right, BTRFS_MIXED_BACKREF_REV); |
5f39d397 CM |
3793 | btrfs_set_header_owner(right, root->root_key.objectid); |
3794 | btrfs_set_header_level(right, 0); | |
3795 | write_extent_buffer(right, root->fs_info->fsid, | |
3796 | (unsigned long)btrfs_header_fsid(right), | |
3797 | BTRFS_FSID_SIZE); | |
e17cade2 CM |
3798 | |
3799 | write_extent_buffer(right, root->fs_info->chunk_tree_uuid, | |
3800 | (unsigned long)btrfs_header_chunk_tree_uuid(right), | |
3801 | BTRFS_UUID_SIZE); | |
44871b1b | 3802 | |
5d4f98a2 YZ |
3803 | if (split == 0) { |
3804 | if (mid <= slot) { | |
3805 | btrfs_set_header_nritems(right, 0); | |
143bede5 | 3806 | insert_ptr(trans, root, path, &disk_key, right->start, |
f3ea38da | 3807 | path->slots[1] + 1, 1, 0); |
5d4f98a2 YZ |
3808 | btrfs_tree_unlock(path->nodes[0]); |
3809 | free_extent_buffer(path->nodes[0]); | |
3810 | path->nodes[0] = right; | |
3811 | path->slots[0] = 0; | |
3812 | path->slots[1] += 1; | |
3813 | } else { | |
3814 | btrfs_set_header_nritems(right, 0); | |
143bede5 | 3815 | insert_ptr(trans, root, path, &disk_key, right->start, |
f3ea38da | 3816 | path->slots[1], 1, 0); |
5d4f98a2 YZ |
3817 | btrfs_tree_unlock(path->nodes[0]); |
3818 | free_extent_buffer(path->nodes[0]); | |
3819 | path->nodes[0] = right; | |
3820 | path->slots[0] = 0; | |
143bede5 JM |
3821 | if (path->slots[1] == 0) |
3822 | fixup_low_keys(trans, root, path, | |
3823 | &disk_key, 1); | |
d4dbff95 | 3824 | } |
5d4f98a2 YZ |
3825 | btrfs_mark_buffer_dirty(right); |
3826 | return ret; | |
d4dbff95 | 3827 | } |
74123bd7 | 3828 | |
143bede5 | 3829 | copy_for_split(trans, root, path, l, right, slot, mid, nritems); |
31840ae1 | 3830 | |
5d4f98a2 | 3831 | if (split == 2) { |
cc0c5538 CM |
3832 | BUG_ON(num_doubles != 0); |
3833 | num_doubles++; | |
3834 | goto again; | |
a429e513 | 3835 | } |
44871b1b | 3836 | |
143bede5 | 3837 | return 0; |
99d8f83c CM |
3838 | |
3839 | push_for_double: | |
3840 | push_for_double_split(trans, root, path, data_size); | |
3841 | tried_avoid_double = 1; | |
3842 | if (btrfs_leaf_free_space(root, path->nodes[0]) >= data_size) | |
3843 | return 0; | |
3844 | goto again; | |
be0e5c09 CM |
3845 | } |
3846 | ||
ad48fd75 YZ |
3847 | static noinline int setup_leaf_for_split(struct btrfs_trans_handle *trans, |
3848 | struct btrfs_root *root, | |
3849 | struct btrfs_path *path, int ins_len) | |
459931ec | 3850 | { |
ad48fd75 | 3851 | struct btrfs_key key; |
459931ec | 3852 | struct extent_buffer *leaf; |
ad48fd75 YZ |
3853 | struct btrfs_file_extent_item *fi; |
3854 | u64 extent_len = 0; | |
3855 | u32 item_size; | |
3856 | int ret; | |
459931ec CM |
3857 | |
3858 | leaf = path->nodes[0]; | |
ad48fd75 YZ |
3859 | btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
3860 | ||
3861 | BUG_ON(key.type != BTRFS_EXTENT_DATA_KEY && | |
3862 | key.type != BTRFS_EXTENT_CSUM_KEY); | |
3863 | ||
3864 | if (btrfs_leaf_free_space(root, leaf) >= ins_len) | |
3865 | return 0; | |
459931ec CM |
3866 | |
3867 | item_size = btrfs_item_size_nr(leaf, path->slots[0]); | |
ad48fd75 YZ |
3868 | if (key.type == BTRFS_EXTENT_DATA_KEY) { |
3869 | fi = btrfs_item_ptr(leaf, path->slots[0], | |
3870 | struct btrfs_file_extent_item); | |
3871 | extent_len = btrfs_file_extent_num_bytes(leaf, fi); | |
3872 | } | |
b3b4aa74 | 3873 | btrfs_release_path(path); |
459931ec | 3874 | |
459931ec | 3875 | path->keep_locks = 1; |
ad48fd75 YZ |
3876 | path->search_for_split = 1; |
3877 | ret = btrfs_search_slot(trans, root, &key, path, 0, 1); | |
459931ec | 3878 | path->search_for_split = 0; |
ad48fd75 YZ |
3879 | if (ret < 0) |
3880 | goto err; | |
459931ec | 3881 | |
ad48fd75 YZ |
3882 | ret = -EAGAIN; |
3883 | leaf = path->nodes[0]; | |
459931ec | 3884 | /* if our item isn't there or got smaller, return now */ |
ad48fd75 YZ |
3885 | if (ret > 0 || item_size != btrfs_item_size_nr(leaf, path->slots[0])) |
3886 | goto err; | |
3887 | ||
109f6aef CM |
3888 | /* the leaf has changed, it now has room. return now */ |
3889 | if (btrfs_leaf_free_space(root, path->nodes[0]) >= ins_len) | |
3890 | goto err; | |
3891 | ||
ad48fd75 YZ |
3892 | if (key.type == BTRFS_EXTENT_DATA_KEY) { |
3893 | fi = btrfs_item_ptr(leaf, path->slots[0], | |
3894 | struct btrfs_file_extent_item); | |
3895 | if (extent_len != btrfs_file_extent_num_bytes(leaf, fi)) | |
3896 | goto err; | |
459931ec CM |
3897 | } |
3898 | ||
b9473439 | 3899 | btrfs_set_path_blocking(path); |
ad48fd75 | 3900 | ret = split_leaf(trans, root, &key, path, ins_len, 1); |
f0486c68 YZ |
3901 | if (ret) |
3902 | goto err; | |
459931ec | 3903 | |
ad48fd75 | 3904 | path->keep_locks = 0; |
b9473439 | 3905 | btrfs_unlock_up_safe(path, 1); |
ad48fd75 YZ |
3906 | return 0; |
3907 | err: | |
3908 | path->keep_locks = 0; | |
3909 | return ret; | |
3910 | } | |
3911 | ||
3912 | static noinline int split_item(struct btrfs_trans_handle *trans, | |
3913 | struct btrfs_root *root, | |
3914 | struct btrfs_path *path, | |
3915 | struct btrfs_key *new_key, | |
3916 | unsigned long split_offset) | |
3917 | { | |
3918 | struct extent_buffer *leaf; | |
3919 | struct btrfs_item *item; | |
3920 | struct btrfs_item *new_item; | |
3921 | int slot; | |
3922 | char *buf; | |
3923 | u32 nritems; | |
3924 | u32 item_size; | |
3925 | u32 orig_offset; | |
3926 | struct btrfs_disk_key disk_key; | |
3927 | ||
b9473439 CM |
3928 | leaf = path->nodes[0]; |
3929 | BUG_ON(btrfs_leaf_free_space(root, leaf) < sizeof(struct btrfs_item)); | |
3930 | ||
b4ce94de CM |
3931 | btrfs_set_path_blocking(path); |
3932 | ||
459931ec CM |
3933 | item = btrfs_item_nr(leaf, path->slots[0]); |
3934 | orig_offset = btrfs_item_offset(leaf, item); | |
3935 | item_size = btrfs_item_size(leaf, item); | |
3936 | ||
459931ec | 3937 | buf = kmalloc(item_size, GFP_NOFS); |
ad48fd75 YZ |
3938 | if (!buf) |
3939 | return -ENOMEM; | |
3940 | ||
459931ec CM |
3941 | read_extent_buffer(leaf, buf, btrfs_item_ptr_offset(leaf, |
3942 | path->slots[0]), item_size); | |
459931ec | 3943 | |
ad48fd75 | 3944 | slot = path->slots[0] + 1; |
459931ec | 3945 | nritems = btrfs_header_nritems(leaf); |
459931ec CM |
3946 | if (slot != nritems) { |
3947 | /* shift the items */ | |
3948 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + 1), | |
ad48fd75 YZ |
3949 | btrfs_item_nr_offset(slot), |
3950 | (nritems - slot) * sizeof(struct btrfs_item)); | |
459931ec CM |
3951 | } |
3952 | ||
3953 | btrfs_cpu_key_to_disk(&disk_key, new_key); | |
3954 | btrfs_set_item_key(leaf, &disk_key, slot); | |
3955 | ||
3956 | new_item = btrfs_item_nr(leaf, slot); | |
3957 | ||
3958 | btrfs_set_item_offset(leaf, new_item, orig_offset); | |
3959 | btrfs_set_item_size(leaf, new_item, item_size - split_offset); | |
3960 | ||
3961 | btrfs_set_item_offset(leaf, item, | |
3962 | orig_offset + item_size - split_offset); | |
3963 | btrfs_set_item_size(leaf, item, split_offset); | |
3964 | ||
3965 | btrfs_set_header_nritems(leaf, nritems + 1); | |
3966 | ||
3967 | /* write the data for the start of the original item */ | |
3968 | write_extent_buffer(leaf, buf, | |
3969 | btrfs_item_ptr_offset(leaf, path->slots[0]), | |
3970 | split_offset); | |
3971 | ||
3972 | /* write the data for the new item */ | |
3973 | write_extent_buffer(leaf, buf + split_offset, | |
3974 | btrfs_item_ptr_offset(leaf, slot), | |
3975 | item_size - split_offset); | |
3976 | btrfs_mark_buffer_dirty(leaf); | |
3977 | ||
ad48fd75 | 3978 | BUG_ON(btrfs_leaf_free_space(root, leaf) < 0); |
459931ec | 3979 | kfree(buf); |
ad48fd75 YZ |
3980 | return 0; |
3981 | } | |
3982 | ||
3983 | /* | |
3984 | * This function splits a single item into two items, | |
3985 | * giving 'new_key' to the new item and splitting the | |
3986 | * old one at split_offset (from the start of the item). | |
3987 | * | |
3988 | * The path may be released by this operation. After | |
3989 | * the split, the path is pointing to the old item. The | |
3990 | * new item is going to be in the same node as the old one. | |
3991 | * | |
3992 | * Note, the item being split must be smaller enough to live alone on | |
3993 | * a tree block with room for one extra struct btrfs_item | |
3994 | * | |
3995 | * This allows us to split the item in place, keeping a lock on the | |
3996 | * leaf the entire time. | |
3997 | */ | |
3998 | int btrfs_split_item(struct btrfs_trans_handle *trans, | |
3999 | struct btrfs_root *root, | |
4000 | struct btrfs_path *path, | |
4001 | struct btrfs_key *new_key, | |
4002 | unsigned long split_offset) | |
4003 | { | |
4004 | int ret; | |
4005 | ret = setup_leaf_for_split(trans, root, path, | |
4006 | sizeof(struct btrfs_item)); | |
4007 | if (ret) | |
4008 | return ret; | |
4009 | ||
4010 | ret = split_item(trans, root, path, new_key, split_offset); | |
459931ec CM |
4011 | return ret; |
4012 | } | |
4013 | ||
ad48fd75 YZ |
4014 | /* |
4015 | * This function duplicate a item, giving 'new_key' to the new item. | |
4016 | * It guarantees both items live in the same tree leaf and the new item | |
4017 | * is contiguous with the original item. | |
4018 | * | |
4019 | * This allows us to split file extent in place, keeping a lock on the | |
4020 | * leaf the entire time. | |
4021 | */ | |
4022 | int btrfs_duplicate_item(struct btrfs_trans_handle *trans, | |
4023 | struct btrfs_root *root, | |
4024 | struct btrfs_path *path, | |
4025 | struct btrfs_key *new_key) | |
4026 | { | |
4027 | struct extent_buffer *leaf; | |
4028 | int ret; | |
4029 | u32 item_size; | |
4030 | ||
4031 | leaf = path->nodes[0]; | |
4032 | item_size = btrfs_item_size_nr(leaf, path->slots[0]); | |
4033 | ret = setup_leaf_for_split(trans, root, path, | |
4034 | item_size + sizeof(struct btrfs_item)); | |
4035 | if (ret) | |
4036 | return ret; | |
4037 | ||
4038 | path->slots[0]++; | |
143bede5 JM |
4039 | setup_items_for_insert(trans, root, path, new_key, &item_size, |
4040 | item_size, item_size + | |
4041 | sizeof(struct btrfs_item), 1); | |
ad48fd75 YZ |
4042 | leaf = path->nodes[0]; |
4043 | memcpy_extent_buffer(leaf, | |
4044 | btrfs_item_ptr_offset(leaf, path->slots[0]), | |
4045 | btrfs_item_ptr_offset(leaf, path->slots[0] - 1), | |
4046 | item_size); | |
4047 | return 0; | |
4048 | } | |
4049 | ||
d352ac68 CM |
4050 | /* |
4051 | * make the item pointed to by the path smaller. new_size indicates | |
4052 | * how small to make it, and from_end tells us if we just chop bytes | |
4053 | * off the end of the item or if we shift the item to chop bytes off | |
4054 | * the front. | |
4055 | */ | |
143bede5 JM |
4056 | void btrfs_truncate_item(struct btrfs_trans_handle *trans, |
4057 | struct btrfs_root *root, | |
4058 | struct btrfs_path *path, | |
4059 | u32 new_size, int from_end) | |
b18c6685 | 4060 | { |
b18c6685 | 4061 | int slot; |
5f39d397 CM |
4062 | struct extent_buffer *leaf; |
4063 | struct btrfs_item *item; | |
b18c6685 CM |
4064 | u32 nritems; |
4065 | unsigned int data_end; | |
4066 | unsigned int old_data_start; | |
4067 | unsigned int old_size; | |
4068 | unsigned int size_diff; | |
4069 | int i; | |
cfed81a0 CM |
4070 | struct btrfs_map_token token; |
4071 | ||
4072 | btrfs_init_map_token(&token); | |
b18c6685 | 4073 | |
5f39d397 | 4074 | leaf = path->nodes[0]; |
179e29e4 CM |
4075 | slot = path->slots[0]; |
4076 | ||
4077 | old_size = btrfs_item_size_nr(leaf, slot); | |
4078 | if (old_size == new_size) | |
143bede5 | 4079 | return; |
b18c6685 | 4080 | |
5f39d397 | 4081 | nritems = btrfs_header_nritems(leaf); |
b18c6685 CM |
4082 | data_end = leaf_data_end(root, leaf); |
4083 | ||
5f39d397 | 4084 | old_data_start = btrfs_item_offset_nr(leaf, slot); |
179e29e4 | 4085 | |
b18c6685 CM |
4086 | size_diff = old_size - new_size; |
4087 | ||
4088 | BUG_ON(slot < 0); | |
4089 | BUG_ON(slot >= nritems); | |
4090 | ||
4091 | /* | |
4092 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
4093 | */ | |
4094 | /* first correct the data pointers */ | |
4095 | for (i = slot; i < nritems; i++) { | |
5f39d397 CM |
4096 | u32 ioff; |
4097 | item = btrfs_item_nr(leaf, i); | |
db94535d | 4098 | |
cfed81a0 CM |
4099 | ioff = btrfs_token_item_offset(leaf, item, &token); |
4100 | btrfs_set_token_item_offset(leaf, item, | |
4101 | ioff + size_diff, &token); | |
b18c6685 | 4102 | } |
db94535d | 4103 | |
b18c6685 | 4104 | /* shift the data */ |
179e29e4 CM |
4105 | if (from_end) { |
4106 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + | |
4107 | data_end + size_diff, btrfs_leaf_data(leaf) + | |
4108 | data_end, old_data_start + new_size - data_end); | |
4109 | } else { | |
4110 | struct btrfs_disk_key disk_key; | |
4111 | u64 offset; | |
4112 | ||
4113 | btrfs_item_key(leaf, &disk_key, slot); | |
4114 | ||
4115 | if (btrfs_disk_key_type(&disk_key) == BTRFS_EXTENT_DATA_KEY) { | |
4116 | unsigned long ptr; | |
4117 | struct btrfs_file_extent_item *fi; | |
4118 | ||
4119 | fi = btrfs_item_ptr(leaf, slot, | |
4120 | struct btrfs_file_extent_item); | |
4121 | fi = (struct btrfs_file_extent_item *)( | |
4122 | (unsigned long)fi - size_diff); | |
4123 | ||
4124 | if (btrfs_file_extent_type(leaf, fi) == | |
4125 | BTRFS_FILE_EXTENT_INLINE) { | |
4126 | ptr = btrfs_item_ptr_offset(leaf, slot); | |
4127 | memmove_extent_buffer(leaf, ptr, | |
d397712b CM |
4128 | (unsigned long)fi, |
4129 | offsetof(struct btrfs_file_extent_item, | |
179e29e4 CM |
4130 | disk_bytenr)); |
4131 | } | |
4132 | } | |
4133 | ||
4134 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + | |
4135 | data_end + size_diff, btrfs_leaf_data(leaf) + | |
4136 | data_end, old_data_start - data_end); | |
4137 | ||
4138 | offset = btrfs_disk_key_offset(&disk_key); | |
4139 | btrfs_set_disk_key_offset(&disk_key, offset + size_diff); | |
4140 | btrfs_set_item_key(leaf, &disk_key, slot); | |
4141 | if (slot == 0) | |
4142 | fixup_low_keys(trans, root, path, &disk_key, 1); | |
4143 | } | |
5f39d397 CM |
4144 | |
4145 | item = btrfs_item_nr(leaf, slot); | |
4146 | btrfs_set_item_size(leaf, item, new_size); | |
4147 | btrfs_mark_buffer_dirty(leaf); | |
b18c6685 | 4148 | |
5f39d397 CM |
4149 | if (btrfs_leaf_free_space(root, leaf) < 0) { |
4150 | btrfs_print_leaf(root, leaf); | |
b18c6685 | 4151 | BUG(); |
5f39d397 | 4152 | } |
b18c6685 CM |
4153 | } |
4154 | ||
d352ac68 CM |
4155 | /* |
4156 | * make the item pointed to by the path bigger, data_size is the new size. | |
4157 | */ | |
143bede5 JM |
4158 | void btrfs_extend_item(struct btrfs_trans_handle *trans, |
4159 | struct btrfs_root *root, struct btrfs_path *path, | |
4160 | u32 data_size) | |
6567e837 | 4161 | { |
6567e837 | 4162 | int slot; |
5f39d397 CM |
4163 | struct extent_buffer *leaf; |
4164 | struct btrfs_item *item; | |
6567e837 CM |
4165 | u32 nritems; |
4166 | unsigned int data_end; | |
4167 | unsigned int old_data; | |
4168 | unsigned int old_size; | |
4169 | int i; | |
cfed81a0 CM |
4170 | struct btrfs_map_token token; |
4171 | ||
4172 | btrfs_init_map_token(&token); | |
6567e837 | 4173 | |
5f39d397 | 4174 | leaf = path->nodes[0]; |
6567e837 | 4175 | |
5f39d397 | 4176 | nritems = btrfs_header_nritems(leaf); |
6567e837 CM |
4177 | data_end = leaf_data_end(root, leaf); |
4178 | ||
5f39d397 CM |
4179 | if (btrfs_leaf_free_space(root, leaf) < data_size) { |
4180 | btrfs_print_leaf(root, leaf); | |
6567e837 | 4181 | BUG(); |
5f39d397 | 4182 | } |
6567e837 | 4183 | slot = path->slots[0]; |
5f39d397 | 4184 | old_data = btrfs_item_end_nr(leaf, slot); |
6567e837 CM |
4185 | |
4186 | BUG_ON(slot < 0); | |
3326d1b0 CM |
4187 | if (slot >= nritems) { |
4188 | btrfs_print_leaf(root, leaf); | |
d397712b CM |
4189 | printk(KERN_CRIT "slot %d too large, nritems %d\n", |
4190 | slot, nritems); | |
3326d1b0 CM |
4191 | BUG_ON(1); |
4192 | } | |
6567e837 CM |
4193 | |
4194 | /* | |
4195 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
4196 | */ | |
4197 | /* first correct the data pointers */ | |
4198 | for (i = slot; i < nritems; i++) { | |
5f39d397 CM |
4199 | u32 ioff; |
4200 | item = btrfs_item_nr(leaf, i); | |
db94535d | 4201 | |
cfed81a0 CM |
4202 | ioff = btrfs_token_item_offset(leaf, item, &token); |
4203 | btrfs_set_token_item_offset(leaf, item, | |
4204 | ioff - data_size, &token); | |
6567e837 | 4205 | } |
5f39d397 | 4206 | |
6567e837 | 4207 | /* shift the data */ |
5f39d397 | 4208 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + |
6567e837 CM |
4209 | data_end - data_size, btrfs_leaf_data(leaf) + |
4210 | data_end, old_data - data_end); | |
5f39d397 | 4211 | |
6567e837 | 4212 | data_end = old_data; |
5f39d397 CM |
4213 | old_size = btrfs_item_size_nr(leaf, slot); |
4214 | item = btrfs_item_nr(leaf, slot); | |
4215 | btrfs_set_item_size(leaf, item, old_size + data_size); | |
4216 | btrfs_mark_buffer_dirty(leaf); | |
6567e837 | 4217 | |
5f39d397 CM |
4218 | if (btrfs_leaf_free_space(root, leaf) < 0) { |
4219 | btrfs_print_leaf(root, leaf); | |
6567e837 | 4220 | BUG(); |
5f39d397 | 4221 | } |
6567e837 CM |
4222 | } |
4223 | ||
f3465ca4 JB |
4224 | /* |
4225 | * Given a key and some data, insert items into the tree. | |
4226 | * This does all the path init required, making room in the tree if needed. | |
4227 | * Returns the number of keys that were inserted. | |
4228 | */ | |
4229 | int btrfs_insert_some_items(struct btrfs_trans_handle *trans, | |
4230 | struct btrfs_root *root, | |
4231 | struct btrfs_path *path, | |
4232 | struct btrfs_key *cpu_key, u32 *data_size, | |
4233 | int nr) | |
4234 | { | |
4235 | struct extent_buffer *leaf; | |
4236 | struct btrfs_item *item; | |
4237 | int ret = 0; | |
4238 | int slot; | |
f3465ca4 JB |
4239 | int i; |
4240 | u32 nritems; | |
4241 | u32 total_data = 0; | |
4242 | u32 total_size = 0; | |
4243 | unsigned int data_end; | |
4244 | struct btrfs_disk_key disk_key; | |
4245 | struct btrfs_key found_key; | |
cfed81a0 CM |
4246 | struct btrfs_map_token token; |
4247 | ||
4248 | btrfs_init_map_token(&token); | |
f3465ca4 | 4249 | |
87b29b20 YZ |
4250 | for (i = 0; i < nr; i++) { |
4251 | if (total_size + data_size[i] + sizeof(struct btrfs_item) > | |
4252 | BTRFS_LEAF_DATA_SIZE(root)) { | |
4253 | break; | |
4254 | nr = i; | |
4255 | } | |
f3465ca4 | 4256 | total_data += data_size[i]; |
87b29b20 YZ |
4257 | total_size += data_size[i] + sizeof(struct btrfs_item); |
4258 | } | |
4259 | BUG_ON(nr == 0); | |
f3465ca4 | 4260 | |
f3465ca4 JB |
4261 | ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1); |
4262 | if (ret == 0) | |
4263 | return -EEXIST; | |
4264 | if (ret < 0) | |
4265 | goto out; | |
4266 | ||
f3465ca4 JB |
4267 | leaf = path->nodes[0]; |
4268 | ||
4269 | nritems = btrfs_header_nritems(leaf); | |
4270 | data_end = leaf_data_end(root, leaf); | |
4271 | ||
4272 | if (btrfs_leaf_free_space(root, leaf) < total_size) { | |
4273 | for (i = nr; i >= 0; i--) { | |
4274 | total_data -= data_size[i]; | |
4275 | total_size -= data_size[i] + sizeof(struct btrfs_item); | |
4276 | if (total_size < btrfs_leaf_free_space(root, leaf)) | |
4277 | break; | |
4278 | } | |
4279 | nr = i; | |
4280 | } | |
4281 | ||
4282 | slot = path->slots[0]; | |
4283 | BUG_ON(slot < 0); | |
4284 | ||
4285 | if (slot != nritems) { | |
4286 | unsigned int old_data = btrfs_item_end_nr(leaf, slot); | |
4287 | ||
4288 | item = btrfs_item_nr(leaf, slot); | |
4289 | btrfs_item_key_to_cpu(leaf, &found_key, slot); | |
4290 | ||
4291 | /* figure out how many keys we can insert in here */ | |
4292 | total_data = data_size[0]; | |
4293 | for (i = 1; i < nr; i++) { | |
5d4f98a2 | 4294 | if (btrfs_comp_cpu_keys(&found_key, cpu_key + i) <= 0) |
f3465ca4 JB |
4295 | break; |
4296 | total_data += data_size[i]; | |
4297 | } | |
4298 | nr = i; | |
4299 | ||
4300 | if (old_data < data_end) { | |
4301 | btrfs_print_leaf(root, leaf); | |
d397712b | 4302 | printk(KERN_CRIT "slot %d old_data %d data_end %d\n", |
f3465ca4 JB |
4303 | slot, old_data, data_end); |
4304 | BUG_ON(1); | |
4305 | } | |
4306 | /* | |
4307 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
4308 | */ | |
4309 | /* first correct the data pointers */ | |
f3465ca4 JB |
4310 | for (i = slot; i < nritems; i++) { |
4311 | u32 ioff; | |
4312 | ||
4313 | item = btrfs_item_nr(leaf, i); | |
cfed81a0 CM |
4314 | ioff = btrfs_token_item_offset(leaf, item, &token); |
4315 | btrfs_set_token_item_offset(leaf, item, | |
4316 | ioff - total_data, &token); | |
f3465ca4 | 4317 | } |
f3465ca4 JB |
4318 | /* shift the items */ |
4319 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr), | |
4320 | btrfs_item_nr_offset(slot), | |
4321 | (nritems - slot) * sizeof(struct btrfs_item)); | |
4322 | ||
4323 | /* shift the data */ | |
4324 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + | |
4325 | data_end - total_data, btrfs_leaf_data(leaf) + | |
4326 | data_end, old_data - data_end); | |
4327 | data_end = old_data; | |
4328 | } else { | |
4329 | /* | |
4330 | * this sucks but it has to be done, if we are inserting at | |
4331 | * the end of the leaf only insert 1 of the items, since we | |
4332 | * have no way of knowing whats on the next leaf and we'd have | |
4333 | * to drop our current locks to figure it out | |
4334 | */ | |
4335 | nr = 1; | |
4336 | } | |
4337 | ||
4338 | /* setup the item for the new data */ | |
4339 | for (i = 0; i < nr; i++) { | |
4340 | btrfs_cpu_key_to_disk(&disk_key, cpu_key + i); | |
4341 | btrfs_set_item_key(leaf, &disk_key, slot + i); | |
4342 | item = btrfs_item_nr(leaf, slot + i); | |
cfed81a0 CM |
4343 | btrfs_set_token_item_offset(leaf, item, |
4344 | data_end - data_size[i], &token); | |
f3465ca4 | 4345 | data_end -= data_size[i]; |
cfed81a0 | 4346 | btrfs_set_token_item_size(leaf, item, data_size[i], &token); |
f3465ca4 JB |
4347 | } |
4348 | btrfs_set_header_nritems(leaf, nritems + nr); | |
4349 | btrfs_mark_buffer_dirty(leaf); | |
4350 | ||
4351 | ret = 0; | |
4352 | if (slot == 0) { | |
4353 | btrfs_cpu_key_to_disk(&disk_key, cpu_key); | |
143bede5 | 4354 | fixup_low_keys(trans, root, path, &disk_key, 1); |
f3465ca4 JB |
4355 | } |
4356 | ||
4357 | if (btrfs_leaf_free_space(root, leaf) < 0) { | |
4358 | btrfs_print_leaf(root, leaf); | |
4359 | BUG(); | |
4360 | } | |
4361 | out: | |
4362 | if (!ret) | |
4363 | ret = nr; | |
4364 | return ret; | |
4365 | } | |
4366 | ||
74123bd7 | 4367 | /* |
44871b1b CM |
4368 | * this is a helper for btrfs_insert_empty_items, the main goal here is |
4369 | * to save stack depth by doing the bulk of the work in a function | |
4370 | * that doesn't call btrfs_search_slot | |
74123bd7 | 4371 | */ |
143bede5 JM |
4372 | void setup_items_for_insert(struct btrfs_trans_handle *trans, |
4373 | struct btrfs_root *root, struct btrfs_path *path, | |
4374 | struct btrfs_key *cpu_key, u32 *data_size, | |
4375 | u32 total_data, u32 total_size, int nr) | |
be0e5c09 | 4376 | { |
5f39d397 | 4377 | struct btrfs_item *item; |
9c58309d | 4378 | int i; |
7518a238 | 4379 | u32 nritems; |
be0e5c09 | 4380 | unsigned int data_end; |
e2fa7227 | 4381 | struct btrfs_disk_key disk_key; |
44871b1b CM |
4382 | struct extent_buffer *leaf; |
4383 | int slot; | |
cfed81a0 CM |
4384 | struct btrfs_map_token token; |
4385 | ||
4386 | btrfs_init_map_token(&token); | |
e2fa7227 | 4387 | |
5f39d397 | 4388 | leaf = path->nodes[0]; |
44871b1b | 4389 | slot = path->slots[0]; |
74123bd7 | 4390 | |
5f39d397 | 4391 | nritems = btrfs_header_nritems(leaf); |
123abc88 | 4392 | data_end = leaf_data_end(root, leaf); |
eb60ceac | 4393 | |
f25956cc | 4394 | if (btrfs_leaf_free_space(root, leaf) < total_size) { |
3326d1b0 | 4395 | btrfs_print_leaf(root, leaf); |
d397712b | 4396 | printk(KERN_CRIT "not enough freespace need %u have %d\n", |
9c58309d | 4397 | total_size, btrfs_leaf_free_space(root, leaf)); |
be0e5c09 | 4398 | BUG(); |
d4dbff95 | 4399 | } |
5f39d397 | 4400 | |
be0e5c09 | 4401 | if (slot != nritems) { |
5f39d397 | 4402 | unsigned int old_data = btrfs_item_end_nr(leaf, slot); |
be0e5c09 | 4403 | |
5f39d397 CM |
4404 | if (old_data < data_end) { |
4405 | btrfs_print_leaf(root, leaf); | |
d397712b | 4406 | printk(KERN_CRIT "slot %d old_data %d data_end %d\n", |
5f39d397 CM |
4407 | slot, old_data, data_end); |
4408 | BUG_ON(1); | |
4409 | } | |
be0e5c09 CM |
4410 | /* |
4411 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
4412 | */ | |
4413 | /* first correct the data pointers */ | |
0783fcfc | 4414 | for (i = slot; i < nritems; i++) { |
5f39d397 | 4415 | u32 ioff; |
db94535d | 4416 | |
5f39d397 | 4417 | item = btrfs_item_nr(leaf, i); |
cfed81a0 CM |
4418 | ioff = btrfs_token_item_offset(leaf, item, &token); |
4419 | btrfs_set_token_item_offset(leaf, item, | |
4420 | ioff - total_data, &token); | |
0783fcfc | 4421 | } |
be0e5c09 | 4422 | /* shift the items */ |
9c58309d | 4423 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr), |
5f39d397 | 4424 | btrfs_item_nr_offset(slot), |
d6025579 | 4425 | (nritems - slot) * sizeof(struct btrfs_item)); |
be0e5c09 CM |
4426 | |
4427 | /* shift the data */ | |
5f39d397 | 4428 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + |
9c58309d | 4429 | data_end - total_data, btrfs_leaf_data(leaf) + |
d6025579 | 4430 | data_end, old_data - data_end); |
be0e5c09 CM |
4431 | data_end = old_data; |
4432 | } | |
5f39d397 | 4433 | |
62e2749e | 4434 | /* setup the item for the new data */ |
9c58309d CM |
4435 | for (i = 0; i < nr; i++) { |
4436 | btrfs_cpu_key_to_disk(&disk_key, cpu_key + i); | |
4437 | btrfs_set_item_key(leaf, &disk_key, slot + i); | |
4438 | item = btrfs_item_nr(leaf, slot + i); | |
cfed81a0 CM |
4439 | btrfs_set_token_item_offset(leaf, item, |
4440 | data_end - data_size[i], &token); | |
9c58309d | 4441 | data_end -= data_size[i]; |
cfed81a0 | 4442 | btrfs_set_token_item_size(leaf, item, data_size[i], &token); |
9c58309d | 4443 | } |
44871b1b | 4444 | |
9c58309d | 4445 | btrfs_set_header_nritems(leaf, nritems + nr); |
aa5d6bed | 4446 | |
5a01a2e3 CM |
4447 | if (slot == 0) { |
4448 | btrfs_cpu_key_to_disk(&disk_key, cpu_key); | |
143bede5 | 4449 | fixup_low_keys(trans, root, path, &disk_key, 1); |
5a01a2e3 | 4450 | } |
b9473439 CM |
4451 | btrfs_unlock_up_safe(path, 1); |
4452 | btrfs_mark_buffer_dirty(leaf); | |
aa5d6bed | 4453 | |
5f39d397 CM |
4454 | if (btrfs_leaf_free_space(root, leaf) < 0) { |
4455 | btrfs_print_leaf(root, leaf); | |
be0e5c09 | 4456 | BUG(); |
5f39d397 | 4457 | } |
44871b1b CM |
4458 | } |
4459 | ||
4460 | /* | |
4461 | * Given a key and some data, insert items into the tree. | |
4462 | * This does all the path init required, making room in the tree if needed. | |
4463 | */ | |
4464 | int btrfs_insert_empty_items(struct btrfs_trans_handle *trans, | |
4465 | struct btrfs_root *root, | |
4466 | struct btrfs_path *path, | |
4467 | struct btrfs_key *cpu_key, u32 *data_size, | |
4468 | int nr) | |
4469 | { | |
44871b1b CM |
4470 | int ret = 0; |
4471 | int slot; | |
4472 | int i; | |
4473 | u32 total_size = 0; | |
4474 | u32 total_data = 0; | |
4475 | ||
4476 | for (i = 0; i < nr; i++) | |
4477 | total_data += data_size[i]; | |
4478 | ||
4479 | total_size = total_data + (nr * sizeof(struct btrfs_item)); | |
4480 | ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1); | |
4481 | if (ret == 0) | |
4482 | return -EEXIST; | |
4483 | if (ret < 0) | |
143bede5 | 4484 | return ret; |
44871b1b | 4485 | |
44871b1b CM |
4486 | slot = path->slots[0]; |
4487 | BUG_ON(slot < 0); | |
4488 | ||
143bede5 | 4489 | setup_items_for_insert(trans, root, path, cpu_key, data_size, |
44871b1b | 4490 | total_data, total_size, nr); |
143bede5 | 4491 | return 0; |
62e2749e CM |
4492 | } |
4493 | ||
4494 | /* | |
4495 | * Given a key and some data, insert an item into the tree. | |
4496 | * This does all the path init required, making room in the tree if needed. | |
4497 | */ | |
e089f05c CM |
4498 | int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root |
4499 | *root, struct btrfs_key *cpu_key, void *data, u32 | |
4500 | data_size) | |
62e2749e CM |
4501 | { |
4502 | int ret = 0; | |
2c90e5d6 | 4503 | struct btrfs_path *path; |
5f39d397 CM |
4504 | struct extent_buffer *leaf; |
4505 | unsigned long ptr; | |
62e2749e | 4506 | |
2c90e5d6 | 4507 | path = btrfs_alloc_path(); |
db5b493a TI |
4508 | if (!path) |
4509 | return -ENOMEM; | |
2c90e5d6 | 4510 | ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size); |
62e2749e | 4511 | if (!ret) { |
5f39d397 CM |
4512 | leaf = path->nodes[0]; |
4513 | ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); | |
4514 | write_extent_buffer(leaf, data, ptr, data_size); | |
4515 | btrfs_mark_buffer_dirty(leaf); | |
62e2749e | 4516 | } |
2c90e5d6 | 4517 | btrfs_free_path(path); |
aa5d6bed | 4518 | return ret; |
be0e5c09 CM |
4519 | } |
4520 | ||
74123bd7 | 4521 | /* |
5de08d7d | 4522 | * delete the pointer from a given node. |
74123bd7 | 4523 | * |
d352ac68 CM |
4524 | * the tree should have been previously balanced so the deletion does not |
4525 | * empty a node. | |
74123bd7 | 4526 | */ |
143bede5 | 4527 | static void del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
f3ea38da JS |
4528 | struct btrfs_path *path, int level, int slot, |
4529 | int tree_mod_log) | |
be0e5c09 | 4530 | { |
5f39d397 | 4531 | struct extent_buffer *parent = path->nodes[level]; |
7518a238 | 4532 | u32 nritems; |
f3ea38da | 4533 | int ret; |
be0e5c09 | 4534 | |
5f39d397 | 4535 | nritems = btrfs_header_nritems(parent); |
d397712b | 4536 | if (slot != nritems - 1) { |
f3ea38da JS |
4537 | if (tree_mod_log && level) |
4538 | tree_mod_log_eb_move(root->fs_info, parent, slot, | |
4539 | slot + 1, nritems - slot - 1); | |
5f39d397 CM |
4540 | memmove_extent_buffer(parent, |
4541 | btrfs_node_key_ptr_offset(slot), | |
4542 | btrfs_node_key_ptr_offset(slot + 1), | |
d6025579 CM |
4543 | sizeof(struct btrfs_key_ptr) * |
4544 | (nritems - slot - 1)); | |
bb803951 | 4545 | } |
f3ea38da JS |
4546 | |
4547 | if (tree_mod_log && level) { | |
4548 | ret = tree_mod_log_insert_key(root->fs_info, parent, slot, | |
4549 | MOD_LOG_KEY_REMOVE); | |
4550 | BUG_ON(ret < 0); | |
4551 | } | |
4552 | ||
7518a238 | 4553 | nritems--; |
5f39d397 | 4554 | btrfs_set_header_nritems(parent, nritems); |
7518a238 | 4555 | if (nritems == 0 && parent == root->node) { |
5f39d397 | 4556 | BUG_ON(btrfs_header_level(root->node) != 1); |
bb803951 | 4557 | /* just turn the root into a leaf and break */ |
5f39d397 | 4558 | btrfs_set_header_level(root->node, 0); |
bb803951 | 4559 | } else if (slot == 0) { |
5f39d397 CM |
4560 | struct btrfs_disk_key disk_key; |
4561 | ||
4562 | btrfs_node_key(parent, &disk_key, 0); | |
143bede5 | 4563 | fixup_low_keys(trans, root, path, &disk_key, level + 1); |
be0e5c09 | 4564 | } |
d6025579 | 4565 | btrfs_mark_buffer_dirty(parent); |
be0e5c09 CM |
4566 | } |
4567 | ||
323ac95b CM |
4568 | /* |
4569 | * a helper function to delete the leaf pointed to by path->slots[1] and | |
5d4f98a2 | 4570 | * path->nodes[1]. |
323ac95b CM |
4571 | * |
4572 | * This deletes the pointer in path->nodes[1] and frees the leaf | |
4573 | * block extent. zero is returned if it all worked out, < 0 otherwise. | |
4574 | * | |
4575 | * The path must have already been setup for deleting the leaf, including | |
4576 | * all the proper balancing. path->nodes[1] must be locked. | |
4577 | */ | |
143bede5 JM |
4578 | static noinline void btrfs_del_leaf(struct btrfs_trans_handle *trans, |
4579 | struct btrfs_root *root, | |
4580 | struct btrfs_path *path, | |
4581 | struct extent_buffer *leaf) | |
323ac95b | 4582 | { |
5d4f98a2 | 4583 | WARN_ON(btrfs_header_generation(leaf) != trans->transid); |
f3ea38da | 4584 | del_ptr(trans, root, path, 1, path->slots[1], 1); |
323ac95b | 4585 | |
4d081c41 CM |
4586 | /* |
4587 | * btrfs_free_extent is expensive, we want to make sure we | |
4588 | * aren't holding any locks when we call it | |
4589 | */ | |
4590 | btrfs_unlock_up_safe(path, 0); | |
4591 | ||
f0486c68 YZ |
4592 | root_sub_used(root, leaf->len); |
4593 | ||
3083ee2e | 4594 | extent_buffer_get(leaf); |
5581a51a | 4595 | btrfs_free_tree_block(trans, root, leaf, 0, 1); |
3083ee2e | 4596 | free_extent_buffer_stale(leaf); |
323ac95b | 4597 | } |
74123bd7 CM |
4598 | /* |
4599 | * delete the item at the leaf level in path. If that empties | |
4600 | * the leaf, remove it from the tree | |
4601 | */ | |
85e21bac CM |
4602 | int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
4603 | struct btrfs_path *path, int slot, int nr) | |
be0e5c09 | 4604 | { |
5f39d397 CM |
4605 | struct extent_buffer *leaf; |
4606 | struct btrfs_item *item; | |
85e21bac CM |
4607 | int last_off; |
4608 | int dsize = 0; | |
aa5d6bed CM |
4609 | int ret = 0; |
4610 | int wret; | |
85e21bac | 4611 | int i; |
7518a238 | 4612 | u32 nritems; |
cfed81a0 CM |
4613 | struct btrfs_map_token token; |
4614 | ||
4615 | btrfs_init_map_token(&token); | |
be0e5c09 | 4616 | |
5f39d397 | 4617 | leaf = path->nodes[0]; |
85e21bac CM |
4618 | last_off = btrfs_item_offset_nr(leaf, slot + nr - 1); |
4619 | ||
4620 | for (i = 0; i < nr; i++) | |
4621 | dsize += btrfs_item_size_nr(leaf, slot + i); | |
4622 | ||
5f39d397 | 4623 | nritems = btrfs_header_nritems(leaf); |
be0e5c09 | 4624 | |
85e21bac | 4625 | if (slot + nr != nritems) { |
123abc88 | 4626 | int data_end = leaf_data_end(root, leaf); |
5f39d397 CM |
4627 | |
4628 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + | |
d6025579 CM |
4629 | data_end + dsize, |
4630 | btrfs_leaf_data(leaf) + data_end, | |
85e21bac | 4631 | last_off - data_end); |
5f39d397 | 4632 | |
85e21bac | 4633 | for (i = slot + nr; i < nritems; i++) { |
5f39d397 | 4634 | u32 ioff; |
db94535d | 4635 | |
5f39d397 | 4636 | item = btrfs_item_nr(leaf, i); |
cfed81a0 CM |
4637 | ioff = btrfs_token_item_offset(leaf, item, &token); |
4638 | btrfs_set_token_item_offset(leaf, item, | |
4639 | ioff + dsize, &token); | |
0783fcfc | 4640 | } |
db94535d | 4641 | |
5f39d397 | 4642 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot), |
85e21bac | 4643 | btrfs_item_nr_offset(slot + nr), |
d6025579 | 4644 | sizeof(struct btrfs_item) * |
85e21bac | 4645 | (nritems - slot - nr)); |
be0e5c09 | 4646 | } |
85e21bac CM |
4647 | btrfs_set_header_nritems(leaf, nritems - nr); |
4648 | nritems -= nr; | |
5f39d397 | 4649 | |
74123bd7 | 4650 | /* delete the leaf if we've emptied it */ |
7518a238 | 4651 | if (nritems == 0) { |
5f39d397 CM |
4652 | if (leaf == root->node) { |
4653 | btrfs_set_header_level(leaf, 0); | |
9a8dd150 | 4654 | } else { |
f0486c68 YZ |
4655 | btrfs_set_path_blocking(path); |
4656 | clean_tree_block(trans, root, leaf); | |
143bede5 | 4657 | btrfs_del_leaf(trans, root, path, leaf); |
9a8dd150 | 4658 | } |
be0e5c09 | 4659 | } else { |
7518a238 | 4660 | int used = leaf_space_used(leaf, 0, nritems); |
aa5d6bed | 4661 | if (slot == 0) { |
5f39d397 CM |
4662 | struct btrfs_disk_key disk_key; |
4663 | ||
4664 | btrfs_item_key(leaf, &disk_key, 0); | |
143bede5 | 4665 | fixup_low_keys(trans, root, path, &disk_key, 1); |
aa5d6bed | 4666 | } |
aa5d6bed | 4667 | |
74123bd7 | 4668 | /* delete the leaf if it is mostly empty */ |
d717aa1d | 4669 | if (used < BTRFS_LEAF_DATA_SIZE(root) / 3) { |
be0e5c09 CM |
4670 | /* push_leaf_left fixes the path. |
4671 | * make sure the path still points to our leaf | |
4672 | * for possible call to del_ptr below | |
4673 | */ | |
4920c9ac | 4674 | slot = path->slots[1]; |
5f39d397 CM |
4675 | extent_buffer_get(leaf); |
4676 | ||
b9473439 | 4677 | btrfs_set_path_blocking(path); |
99d8f83c CM |
4678 | wret = push_leaf_left(trans, root, path, 1, 1, |
4679 | 1, (u32)-1); | |
54aa1f4d | 4680 | if (wret < 0 && wret != -ENOSPC) |
aa5d6bed | 4681 | ret = wret; |
5f39d397 CM |
4682 | |
4683 | if (path->nodes[0] == leaf && | |
4684 | btrfs_header_nritems(leaf)) { | |
99d8f83c CM |
4685 | wret = push_leaf_right(trans, root, path, 1, |
4686 | 1, 1, 0); | |
54aa1f4d | 4687 | if (wret < 0 && wret != -ENOSPC) |
aa5d6bed CM |
4688 | ret = wret; |
4689 | } | |
5f39d397 CM |
4690 | |
4691 | if (btrfs_header_nritems(leaf) == 0) { | |
323ac95b | 4692 | path->slots[1] = slot; |
143bede5 | 4693 | btrfs_del_leaf(trans, root, path, leaf); |
5f39d397 | 4694 | free_extent_buffer(leaf); |
143bede5 | 4695 | ret = 0; |
5de08d7d | 4696 | } else { |
925baedd CM |
4697 | /* if we're still in the path, make sure |
4698 | * we're dirty. Otherwise, one of the | |
4699 | * push_leaf functions must have already | |
4700 | * dirtied this buffer | |
4701 | */ | |
4702 | if (path->nodes[0] == leaf) | |
4703 | btrfs_mark_buffer_dirty(leaf); | |
5f39d397 | 4704 | free_extent_buffer(leaf); |
be0e5c09 | 4705 | } |
d5719762 | 4706 | } else { |
5f39d397 | 4707 | btrfs_mark_buffer_dirty(leaf); |
be0e5c09 CM |
4708 | } |
4709 | } | |
aa5d6bed | 4710 | return ret; |
be0e5c09 CM |
4711 | } |
4712 | ||
7bb86316 | 4713 | /* |
925baedd | 4714 | * search the tree again to find a leaf with lesser keys |
7bb86316 CM |
4715 | * returns 0 if it found something or 1 if there are no lesser leaves. |
4716 | * returns < 0 on io errors. | |
d352ac68 CM |
4717 | * |
4718 | * This may release the path, and so you may lose any locks held at the | |
4719 | * time you call it. | |
7bb86316 CM |
4720 | */ |
4721 | int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path) | |
4722 | { | |
925baedd CM |
4723 | struct btrfs_key key; |
4724 | struct btrfs_disk_key found_key; | |
4725 | int ret; | |
7bb86316 | 4726 | |
925baedd | 4727 | btrfs_item_key_to_cpu(path->nodes[0], &key, 0); |
7bb86316 | 4728 | |
925baedd CM |
4729 | if (key.offset > 0) |
4730 | key.offset--; | |
4731 | else if (key.type > 0) | |
4732 | key.type--; | |
4733 | else if (key.objectid > 0) | |
4734 | key.objectid--; | |
4735 | else | |
4736 | return 1; | |
7bb86316 | 4737 | |
b3b4aa74 | 4738 | btrfs_release_path(path); |
925baedd CM |
4739 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
4740 | if (ret < 0) | |
4741 | return ret; | |
4742 | btrfs_item_key(path->nodes[0], &found_key, 0); | |
4743 | ret = comp_keys(&found_key, &key); | |
4744 | if (ret < 0) | |
4745 | return 0; | |
4746 | return 1; | |
7bb86316 CM |
4747 | } |
4748 | ||
3f157a2f CM |
4749 | /* |
4750 | * A helper function to walk down the tree starting at min_key, and looking | |
4751 | * for nodes or leaves that are either in cache or have a minimum | |
d352ac68 | 4752 | * transaction id. This is used by the btree defrag code, and tree logging |
3f157a2f CM |
4753 | * |
4754 | * This does not cow, but it does stuff the starting key it finds back | |
4755 | * into min_key, so you can call btrfs_search_slot with cow=1 on the | |
4756 | * key and get a writable path. | |
4757 | * | |
4758 | * This does lock as it descends, and path->keep_locks should be set | |
4759 | * to 1 by the caller. | |
4760 | * | |
4761 | * This honors path->lowest_level to prevent descent past a given level | |
4762 | * of the tree. | |
4763 | * | |
d352ac68 CM |
4764 | * min_trans indicates the oldest transaction that you are interested |
4765 | * in walking through. Any nodes or leaves older than min_trans are | |
4766 | * skipped over (without reading them). | |
4767 | * | |
3f157a2f CM |
4768 | * returns zero if something useful was found, < 0 on error and 1 if there |
4769 | * was nothing in the tree that matched the search criteria. | |
4770 | */ | |
4771 | int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key, | |
e02119d5 | 4772 | struct btrfs_key *max_key, |
3f157a2f CM |
4773 | struct btrfs_path *path, int cache_only, |
4774 | u64 min_trans) | |
4775 | { | |
4776 | struct extent_buffer *cur; | |
4777 | struct btrfs_key found_key; | |
4778 | int slot; | |
9652480b | 4779 | int sret; |
3f157a2f CM |
4780 | u32 nritems; |
4781 | int level; | |
4782 | int ret = 1; | |
4783 | ||
934d375b | 4784 | WARN_ON(!path->keep_locks); |
3f157a2f | 4785 | again: |
bd681513 | 4786 | cur = btrfs_read_lock_root_node(root); |
3f157a2f | 4787 | level = btrfs_header_level(cur); |
e02119d5 | 4788 | WARN_ON(path->nodes[level]); |
3f157a2f | 4789 | path->nodes[level] = cur; |
bd681513 | 4790 | path->locks[level] = BTRFS_READ_LOCK; |
3f157a2f CM |
4791 | |
4792 | if (btrfs_header_generation(cur) < min_trans) { | |
4793 | ret = 1; | |
4794 | goto out; | |
4795 | } | |
d397712b | 4796 | while (1) { |
3f157a2f CM |
4797 | nritems = btrfs_header_nritems(cur); |
4798 | level = btrfs_header_level(cur); | |
9652480b | 4799 | sret = bin_search(cur, min_key, level, &slot); |
3f157a2f | 4800 | |
323ac95b CM |
4801 | /* at the lowest level, we're done, setup the path and exit */ |
4802 | if (level == path->lowest_level) { | |
e02119d5 CM |
4803 | if (slot >= nritems) |
4804 | goto find_next_key; | |
3f157a2f CM |
4805 | ret = 0; |
4806 | path->slots[level] = slot; | |
4807 | btrfs_item_key_to_cpu(cur, &found_key, slot); | |
4808 | goto out; | |
4809 | } | |
9652480b Y |
4810 | if (sret && slot > 0) |
4811 | slot--; | |
3f157a2f CM |
4812 | /* |
4813 | * check this node pointer against the cache_only and | |
4814 | * min_trans parameters. If it isn't in cache or is too | |
4815 | * old, skip to the next one. | |
4816 | */ | |
d397712b | 4817 | while (slot < nritems) { |
3f157a2f CM |
4818 | u64 blockptr; |
4819 | u64 gen; | |
4820 | struct extent_buffer *tmp; | |
e02119d5 CM |
4821 | struct btrfs_disk_key disk_key; |
4822 | ||
3f157a2f CM |
4823 | blockptr = btrfs_node_blockptr(cur, slot); |
4824 | gen = btrfs_node_ptr_generation(cur, slot); | |
4825 | if (gen < min_trans) { | |
4826 | slot++; | |
4827 | continue; | |
4828 | } | |
4829 | if (!cache_only) | |
4830 | break; | |
4831 | ||
e02119d5 CM |
4832 | if (max_key) { |
4833 | btrfs_node_key(cur, &disk_key, slot); | |
4834 | if (comp_keys(&disk_key, max_key) >= 0) { | |
4835 | ret = 1; | |
4836 | goto out; | |
4837 | } | |
4838 | } | |
4839 | ||
3f157a2f CM |
4840 | tmp = btrfs_find_tree_block(root, blockptr, |
4841 | btrfs_level_size(root, level - 1)); | |
4842 | ||
b9fab919 | 4843 | if (tmp && btrfs_buffer_uptodate(tmp, gen, 1) > 0) { |
3f157a2f CM |
4844 | free_extent_buffer(tmp); |
4845 | break; | |
4846 | } | |
4847 | if (tmp) | |
4848 | free_extent_buffer(tmp); | |
4849 | slot++; | |
4850 | } | |
e02119d5 | 4851 | find_next_key: |
3f157a2f CM |
4852 | /* |
4853 | * we didn't find a candidate key in this node, walk forward | |
4854 | * and find another one | |
4855 | */ | |
4856 | if (slot >= nritems) { | |
e02119d5 | 4857 | path->slots[level] = slot; |
b4ce94de | 4858 | btrfs_set_path_blocking(path); |
e02119d5 | 4859 | sret = btrfs_find_next_key(root, path, min_key, level, |
3f157a2f | 4860 | cache_only, min_trans); |
e02119d5 | 4861 | if (sret == 0) { |
b3b4aa74 | 4862 | btrfs_release_path(path); |
3f157a2f CM |
4863 | goto again; |
4864 | } else { | |
4865 | goto out; | |
4866 | } | |
4867 | } | |
4868 | /* save our key for returning back */ | |
4869 | btrfs_node_key_to_cpu(cur, &found_key, slot); | |
4870 | path->slots[level] = slot; | |
4871 | if (level == path->lowest_level) { | |
4872 | ret = 0; | |
f7c79f30 | 4873 | unlock_up(path, level, 1, 0, NULL); |
3f157a2f CM |
4874 | goto out; |
4875 | } | |
b4ce94de | 4876 | btrfs_set_path_blocking(path); |
3f157a2f | 4877 | cur = read_node_slot(root, cur, slot); |
79787eaa | 4878 | BUG_ON(!cur); /* -ENOMEM */ |
3f157a2f | 4879 | |
bd681513 | 4880 | btrfs_tree_read_lock(cur); |
b4ce94de | 4881 | |
bd681513 | 4882 | path->locks[level - 1] = BTRFS_READ_LOCK; |
3f157a2f | 4883 | path->nodes[level - 1] = cur; |
f7c79f30 | 4884 | unlock_up(path, level, 1, 0, NULL); |
bd681513 | 4885 | btrfs_clear_path_blocking(path, NULL, 0); |
3f157a2f CM |
4886 | } |
4887 | out: | |
4888 | if (ret == 0) | |
4889 | memcpy(min_key, &found_key, sizeof(found_key)); | |
b4ce94de | 4890 | btrfs_set_path_blocking(path); |
3f157a2f CM |
4891 | return ret; |
4892 | } | |
4893 | ||
4894 | /* | |
4895 | * this is similar to btrfs_next_leaf, but does not try to preserve | |
4896 | * and fixup the path. It looks for and returns the next key in the | |
4897 | * tree based on the current path and the cache_only and min_trans | |
4898 | * parameters. | |
4899 | * | |
4900 | * 0 is returned if another key is found, < 0 if there are any errors | |
4901 | * and 1 is returned if there are no higher keys in the tree | |
4902 | * | |
4903 | * path->keep_locks should be set to 1 on the search made before | |
4904 | * calling this function. | |
4905 | */ | |
e7a84565 | 4906 | int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path, |
33c66f43 | 4907 | struct btrfs_key *key, int level, |
3f157a2f | 4908 | int cache_only, u64 min_trans) |
e7a84565 | 4909 | { |
e7a84565 CM |
4910 | int slot; |
4911 | struct extent_buffer *c; | |
4912 | ||
934d375b | 4913 | WARN_ON(!path->keep_locks); |
d397712b | 4914 | while (level < BTRFS_MAX_LEVEL) { |
e7a84565 CM |
4915 | if (!path->nodes[level]) |
4916 | return 1; | |
4917 | ||
4918 | slot = path->slots[level] + 1; | |
4919 | c = path->nodes[level]; | |
3f157a2f | 4920 | next: |
e7a84565 | 4921 | if (slot >= btrfs_header_nritems(c)) { |
33c66f43 YZ |
4922 | int ret; |
4923 | int orig_lowest; | |
4924 | struct btrfs_key cur_key; | |
4925 | if (level + 1 >= BTRFS_MAX_LEVEL || | |
4926 | !path->nodes[level + 1]) | |
e7a84565 | 4927 | return 1; |
33c66f43 YZ |
4928 | |
4929 | if (path->locks[level + 1]) { | |
4930 | level++; | |
4931 | continue; | |
4932 | } | |
4933 | ||
4934 | slot = btrfs_header_nritems(c) - 1; | |
4935 | if (level == 0) | |
4936 | btrfs_item_key_to_cpu(c, &cur_key, slot); | |
4937 | else | |
4938 | btrfs_node_key_to_cpu(c, &cur_key, slot); | |
4939 | ||
4940 | orig_lowest = path->lowest_level; | |
b3b4aa74 | 4941 | btrfs_release_path(path); |
33c66f43 YZ |
4942 | path->lowest_level = level; |
4943 | ret = btrfs_search_slot(NULL, root, &cur_key, path, | |
4944 | 0, 0); | |
4945 | path->lowest_level = orig_lowest; | |
4946 | if (ret < 0) | |
4947 | return ret; | |
4948 | ||
4949 | c = path->nodes[level]; | |
4950 | slot = path->slots[level]; | |
4951 | if (ret == 0) | |
4952 | slot++; | |
4953 | goto next; | |
e7a84565 | 4954 | } |
33c66f43 | 4955 | |
e7a84565 CM |
4956 | if (level == 0) |
4957 | btrfs_item_key_to_cpu(c, key, slot); | |
3f157a2f CM |
4958 | else { |
4959 | u64 blockptr = btrfs_node_blockptr(c, slot); | |
4960 | u64 gen = btrfs_node_ptr_generation(c, slot); | |
4961 | ||
4962 | if (cache_only) { | |
4963 | struct extent_buffer *cur; | |
4964 | cur = btrfs_find_tree_block(root, blockptr, | |
4965 | btrfs_level_size(root, level - 1)); | |
b9fab919 CM |
4966 | if (!cur || |
4967 | btrfs_buffer_uptodate(cur, gen, 1) <= 0) { | |
3f157a2f CM |
4968 | slot++; |
4969 | if (cur) | |
4970 | free_extent_buffer(cur); | |
4971 | goto next; | |
4972 | } | |
4973 | free_extent_buffer(cur); | |
4974 | } | |
4975 | if (gen < min_trans) { | |
4976 | slot++; | |
4977 | goto next; | |
4978 | } | |
e7a84565 | 4979 | btrfs_node_key_to_cpu(c, key, slot); |
3f157a2f | 4980 | } |
e7a84565 CM |
4981 | return 0; |
4982 | } | |
4983 | return 1; | |
4984 | } | |
4985 | ||
97571fd0 | 4986 | /* |
925baedd | 4987 | * search the tree again to find a leaf with greater keys |
0f70abe2 CM |
4988 | * returns 0 if it found something or 1 if there are no greater leaves. |
4989 | * returns < 0 on io errors. | |
97571fd0 | 4990 | */ |
234b63a0 | 4991 | int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path) |
d97e63b6 CM |
4992 | { |
4993 | int slot; | |
8e73f275 | 4994 | int level; |
5f39d397 | 4995 | struct extent_buffer *c; |
8e73f275 | 4996 | struct extent_buffer *next; |
925baedd CM |
4997 | struct btrfs_key key; |
4998 | u32 nritems; | |
4999 | int ret; | |
8e73f275 | 5000 | int old_spinning = path->leave_spinning; |
bd681513 | 5001 | int next_rw_lock = 0; |
925baedd CM |
5002 | |
5003 | nritems = btrfs_header_nritems(path->nodes[0]); | |
d397712b | 5004 | if (nritems == 0) |
925baedd | 5005 | return 1; |
925baedd | 5006 | |
8e73f275 CM |
5007 | btrfs_item_key_to_cpu(path->nodes[0], &key, nritems - 1); |
5008 | again: | |
5009 | level = 1; | |
5010 | next = NULL; | |
bd681513 | 5011 | next_rw_lock = 0; |
b3b4aa74 | 5012 | btrfs_release_path(path); |
8e73f275 | 5013 | |
a2135011 | 5014 | path->keep_locks = 1; |
31533fb2 | 5015 | path->leave_spinning = 1; |
8e73f275 | 5016 | |
925baedd CM |
5017 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
5018 | path->keep_locks = 0; | |
5019 | ||
5020 | if (ret < 0) | |
5021 | return ret; | |
5022 | ||
a2135011 | 5023 | nritems = btrfs_header_nritems(path->nodes[0]); |
168fd7d2 CM |
5024 | /* |
5025 | * by releasing the path above we dropped all our locks. A balance | |
5026 | * could have added more items next to the key that used to be | |
5027 | * at the very end of the block. So, check again here and | |
5028 | * advance the path if there are now more items available. | |
5029 | */ | |
a2135011 | 5030 | if (nritems > 0 && path->slots[0] < nritems - 1) { |
e457afec YZ |
5031 | if (ret == 0) |
5032 | path->slots[0]++; | |
8e73f275 | 5033 | ret = 0; |
925baedd CM |
5034 | goto done; |
5035 | } | |
d97e63b6 | 5036 | |
d397712b | 5037 | while (level < BTRFS_MAX_LEVEL) { |
8e73f275 CM |
5038 | if (!path->nodes[level]) { |
5039 | ret = 1; | |
5040 | goto done; | |
5041 | } | |
5f39d397 | 5042 | |
d97e63b6 CM |
5043 | slot = path->slots[level] + 1; |
5044 | c = path->nodes[level]; | |
5f39d397 | 5045 | if (slot >= btrfs_header_nritems(c)) { |
d97e63b6 | 5046 | level++; |
8e73f275 CM |
5047 | if (level == BTRFS_MAX_LEVEL) { |
5048 | ret = 1; | |
5049 | goto done; | |
5050 | } | |
d97e63b6 CM |
5051 | continue; |
5052 | } | |
5f39d397 | 5053 | |
925baedd | 5054 | if (next) { |
bd681513 | 5055 | btrfs_tree_unlock_rw(next, next_rw_lock); |
5f39d397 | 5056 | free_extent_buffer(next); |
925baedd | 5057 | } |
5f39d397 | 5058 | |
8e73f275 | 5059 | next = c; |
bd681513 | 5060 | next_rw_lock = path->locks[level]; |
8e73f275 | 5061 | ret = read_block_for_search(NULL, root, path, &next, level, |
5d9e75c4 | 5062 | slot, &key, 0); |
8e73f275 CM |
5063 | if (ret == -EAGAIN) |
5064 | goto again; | |
5f39d397 | 5065 | |
76a05b35 | 5066 | if (ret < 0) { |
b3b4aa74 | 5067 | btrfs_release_path(path); |
76a05b35 CM |
5068 | goto done; |
5069 | } | |
5070 | ||
5cd57b2c | 5071 | if (!path->skip_locking) { |
bd681513 | 5072 | ret = btrfs_try_tree_read_lock(next); |
8e73f275 CM |
5073 | if (!ret) { |
5074 | btrfs_set_path_blocking(path); | |
bd681513 | 5075 | btrfs_tree_read_lock(next); |
31533fb2 | 5076 | btrfs_clear_path_blocking(path, next, |
bd681513 | 5077 | BTRFS_READ_LOCK); |
8e73f275 | 5078 | } |
31533fb2 | 5079 | next_rw_lock = BTRFS_READ_LOCK; |
5cd57b2c | 5080 | } |
d97e63b6 CM |
5081 | break; |
5082 | } | |
5083 | path->slots[level] = slot; | |
d397712b | 5084 | while (1) { |
d97e63b6 CM |
5085 | level--; |
5086 | c = path->nodes[level]; | |
925baedd | 5087 | if (path->locks[level]) |
bd681513 | 5088 | btrfs_tree_unlock_rw(c, path->locks[level]); |
8e73f275 | 5089 | |
5f39d397 | 5090 | free_extent_buffer(c); |
d97e63b6 CM |
5091 | path->nodes[level] = next; |
5092 | path->slots[level] = 0; | |
a74a4b97 | 5093 | if (!path->skip_locking) |
bd681513 | 5094 | path->locks[level] = next_rw_lock; |
d97e63b6 CM |
5095 | if (!level) |
5096 | break; | |
b4ce94de | 5097 | |
8e73f275 | 5098 | ret = read_block_for_search(NULL, root, path, &next, level, |
5d9e75c4 | 5099 | 0, &key, 0); |
8e73f275 CM |
5100 | if (ret == -EAGAIN) |
5101 | goto again; | |
5102 | ||
76a05b35 | 5103 | if (ret < 0) { |
b3b4aa74 | 5104 | btrfs_release_path(path); |
76a05b35 CM |
5105 | goto done; |
5106 | } | |
5107 | ||
5cd57b2c | 5108 | if (!path->skip_locking) { |
bd681513 | 5109 | ret = btrfs_try_tree_read_lock(next); |
8e73f275 CM |
5110 | if (!ret) { |
5111 | btrfs_set_path_blocking(path); | |
bd681513 | 5112 | btrfs_tree_read_lock(next); |
31533fb2 | 5113 | btrfs_clear_path_blocking(path, next, |
bd681513 CM |
5114 | BTRFS_READ_LOCK); |
5115 | } | |
31533fb2 | 5116 | next_rw_lock = BTRFS_READ_LOCK; |
5cd57b2c | 5117 | } |
d97e63b6 | 5118 | } |
8e73f275 | 5119 | ret = 0; |
925baedd | 5120 | done: |
f7c79f30 | 5121 | unlock_up(path, 0, 1, 0, NULL); |
8e73f275 CM |
5122 | path->leave_spinning = old_spinning; |
5123 | if (!old_spinning) | |
5124 | btrfs_set_path_blocking(path); | |
5125 | ||
5126 | return ret; | |
d97e63b6 | 5127 | } |
0b86a832 | 5128 | |
3f157a2f CM |
5129 | /* |
5130 | * this uses btrfs_prev_leaf to walk backwards in the tree, and keeps | |
5131 | * searching until it gets past min_objectid or finds an item of 'type' | |
5132 | * | |
5133 | * returns 0 if something is found, 1 if nothing was found and < 0 on error | |
5134 | */ | |
0b86a832 CM |
5135 | int btrfs_previous_item(struct btrfs_root *root, |
5136 | struct btrfs_path *path, u64 min_objectid, | |
5137 | int type) | |
5138 | { | |
5139 | struct btrfs_key found_key; | |
5140 | struct extent_buffer *leaf; | |
e02119d5 | 5141 | u32 nritems; |
0b86a832 CM |
5142 | int ret; |
5143 | ||
d397712b | 5144 | while (1) { |
0b86a832 | 5145 | if (path->slots[0] == 0) { |
b4ce94de | 5146 | btrfs_set_path_blocking(path); |
0b86a832 CM |
5147 | ret = btrfs_prev_leaf(root, path); |
5148 | if (ret != 0) | |
5149 | return ret; | |
5150 | } else { | |
5151 | path->slots[0]--; | |
5152 | } | |
5153 | leaf = path->nodes[0]; | |
e02119d5 CM |
5154 | nritems = btrfs_header_nritems(leaf); |
5155 | if (nritems == 0) | |
5156 | return 1; | |
5157 | if (path->slots[0] == nritems) | |
5158 | path->slots[0]--; | |
5159 | ||
0b86a832 | 5160 | btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); |
e02119d5 CM |
5161 | if (found_key.objectid < min_objectid) |
5162 | break; | |
0a4eefbb YZ |
5163 | if (found_key.type == type) |
5164 | return 0; | |
e02119d5 CM |
5165 | if (found_key.objectid == min_objectid && |
5166 | found_key.type < type) | |
5167 | break; | |
0b86a832 CM |
5168 | } |
5169 | return 1; | |
5170 | } |