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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); | |
afe5fea7 TI |
40 | static void del_ptr(struct btrfs_root *root, struct btrfs_path *path, |
41 | int level, int slot); | |
5de865ee | 42 | static int tree_mod_log_free_eb(struct btrfs_fs_info *fs_info, |
f230475e | 43 | struct extent_buffer *eb); |
d97e63b6 | 44 | |
df24a2b9 | 45 | struct btrfs_path *btrfs_alloc_path(void) |
2c90e5d6 | 46 | { |
df24a2b9 | 47 | struct btrfs_path *path; |
e00f7308 | 48 | path = kmem_cache_zalloc(btrfs_path_cachep, GFP_NOFS); |
df24a2b9 | 49 | return path; |
2c90e5d6 CM |
50 | } |
51 | ||
b4ce94de CM |
52 | /* |
53 | * set all locked nodes in the path to blocking locks. This should | |
54 | * be done before scheduling | |
55 | */ | |
56 | noinline void btrfs_set_path_blocking(struct btrfs_path *p) | |
57 | { | |
58 | int i; | |
59 | for (i = 0; i < BTRFS_MAX_LEVEL; i++) { | |
bd681513 CM |
60 | if (!p->nodes[i] || !p->locks[i]) |
61 | continue; | |
62 | btrfs_set_lock_blocking_rw(p->nodes[i], p->locks[i]); | |
63 | if (p->locks[i] == BTRFS_READ_LOCK) | |
64 | p->locks[i] = BTRFS_READ_LOCK_BLOCKING; | |
65 | else if (p->locks[i] == BTRFS_WRITE_LOCK) | |
66 | p->locks[i] = BTRFS_WRITE_LOCK_BLOCKING; | |
b4ce94de CM |
67 | } |
68 | } | |
69 | ||
70 | /* | |
71 | * reset all the locked nodes in the patch to spinning locks. | |
4008c04a CM |
72 | * |
73 | * held is used to keep lockdep happy, when lockdep is enabled | |
74 | * we set held to a blocking lock before we go around and | |
75 | * retake all the spinlocks in the path. You can safely use NULL | |
76 | * for held | |
b4ce94de | 77 | */ |
4008c04a | 78 | noinline void btrfs_clear_path_blocking(struct btrfs_path *p, |
bd681513 | 79 | struct extent_buffer *held, int held_rw) |
b4ce94de CM |
80 | { |
81 | int i; | |
4008c04a | 82 | |
bd681513 CM |
83 | if (held) { |
84 | btrfs_set_lock_blocking_rw(held, held_rw); | |
85 | if (held_rw == BTRFS_WRITE_LOCK) | |
86 | held_rw = BTRFS_WRITE_LOCK_BLOCKING; | |
87 | else if (held_rw == BTRFS_READ_LOCK) | |
88 | held_rw = BTRFS_READ_LOCK_BLOCKING; | |
89 | } | |
4008c04a | 90 | btrfs_set_path_blocking(p); |
4008c04a CM |
91 | |
92 | for (i = BTRFS_MAX_LEVEL - 1; i >= 0; i--) { | |
bd681513 CM |
93 | if (p->nodes[i] && p->locks[i]) { |
94 | btrfs_clear_lock_blocking_rw(p->nodes[i], p->locks[i]); | |
95 | if (p->locks[i] == BTRFS_WRITE_LOCK_BLOCKING) | |
96 | p->locks[i] = BTRFS_WRITE_LOCK; | |
97 | else if (p->locks[i] == BTRFS_READ_LOCK_BLOCKING) | |
98 | p->locks[i] = BTRFS_READ_LOCK; | |
99 | } | |
b4ce94de | 100 | } |
4008c04a | 101 | |
4008c04a | 102 | if (held) |
bd681513 | 103 | btrfs_clear_lock_blocking_rw(held, held_rw); |
b4ce94de CM |
104 | } |
105 | ||
d352ac68 | 106 | /* this also releases the path */ |
df24a2b9 | 107 | void btrfs_free_path(struct btrfs_path *p) |
be0e5c09 | 108 | { |
ff175d57 JJ |
109 | if (!p) |
110 | return; | |
b3b4aa74 | 111 | btrfs_release_path(p); |
df24a2b9 | 112 | kmem_cache_free(btrfs_path_cachep, p); |
be0e5c09 CM |
113 | } |
114 | ||
d352ac68 CM |
115 | /* |
116 | * path release drops references on the extent buffers in the path | |
117 | * and it drops any locks held by this path | |
118 | * | |
119 | * It is safe to call this on paths that no locks or extent buffers held. | |
120 | */ | |
b3b4aa74 | 121 | noinline void btrfs_release_path(struct btrfs_path *p) |
eb60ceac CM |
122 | { |
123 | int i; | |
a2135011 | 124 | |
234b63a0 | 125 | for (i = 0; i < BTRFS_MAX_LEVEL; i++) { |
3f157a2f | 126 | p->slots[i] = 0; |
eb60ceac | 127 | if (!p->nodes[i]) |
925baedd CM |
128 | continue; |
129 | if (p->locks[i]) { | |
bd681513 | 130 | btrfs_tree_unlock_rw(p->nodes[i], p->locks[i]); |
925baedd CM |
131 | p->locks[i] = 0; |
132 | } | |
5f39d397 | 133 | free_extent_buffer(p->nodes[i]); |
3f157a2f | 134 | p->nodes[i] = NULL; |
eb60ceac CM |
135 | } |
136 | } | |
137 | ||
d352ac68 CM |
138 | /* |
139 | * safely gets a reference on the root node of a tree. A lock | |
140 | * is not taken, so a concurrent writer may put a different node | |
141 | * at the root of the tree. See btrfs_lock_root_node for the | |
142 | * looping required. | |
143 | * | |
144 | * The extent buffer returned by this has a reference taken, so | |
145 | * it won't disappear. It may stop being the root of the tree | |
146 | * at any time because there are no locks held. | |
147 | */ | |
925baedd CM |
148 | struct extent_buffer *btrfs_root_node(struct btrfs_root *root) |
149 | { | |
150 | struct extent_buffer *eb; | |
240f62c8 | 151 | |
3083ee2e JB |
152 | while (1) { |
153 | rcu_read_lock(); | |
154 | eb = rcu_dereference(root->node); | |
155 | ||
156 | /* | |
157 | * RCU really hurts here, we could free up the root node because | |
158 | * it was cow'ed but we may not get the new root node yet so do | |
159 | * the inc_not_zero dance and if it doesn't work then | |
160 | * synchronize_rcu and try again. | |
161 | */ | |
162 | if (atomic_inc_not_zero(&eb->refs)) { | |
163 | rcu_read_unlock(); | |
164 | break; | |
165 | } | |
166 | rcu_read_unlock(); | |
167 | synchronize_rcu(); | |
168 | } | |
925baedd CM |
169 | return eb; |
170 | } | |
171 | ||
d352ac68 CM |
172 | /* loop around taking references on and locking the root node of the |
173 | * tree until you end up with a lock on the root. A locked buffer | |
174 | * is returned, with a reference held. | |
175 | */ | |
925baedd CM |
176 | struct extent_buffer *btrfs_lock_root_node(struct btrfs_root *root) |
177 | { | |
178 | struct extent_buffer *eb; | |
179 | ||
d397712b | 180 | while (1) { |
925baedd CM |
181 | eb = btrfs_root_node(root); |
182 | btrfs_tree_lock(eb); | |
240f62c8 | 183 | if (eb == root->node) |
925baedd | 184 | break; |
925baedd CM |
185 | btrfs_tree_unlock(eb); |
186 | free_extent_buffer(eb); | |
187 | } | |
188 | return eb; | |
189 | } | |
190 | ||
bd681513 CM |
191 | /* loop around taking references on and locking the root node of the |
192 | * tree until you end up with a lock on the root. A locked buffer | |
193 | * is returned, with a reference held. | |
194 | */ | |
48a3b636 | 195 | static struct extent_buffer *btrfs_read_lock_root_node(struct btrfs_root *root) |
bd681513 CM |
196 | { |
197 | struct extent_buffer *eb; | |
198 | ||
199 | while (1) { | |
200 | eb = btrfs_root_node(root); | |
201 | btrfs_tree_read_lock(eb); | |
202 | if (eb == root->node) | |
203 | break; | |
204 | btrfs_tree_read_unlock(eb); | |
205 | free_extent_buffer(eb); | |
206 | } | |
207 | return eb; | |
208 | } | |
209 | ||
d352ac68 CM |
210 | /* cowonly root (everything not a reference counted cow subvolume), just get |
211 | * put onto a simple dirty list. transaction.c walks this to make sure they | |
212 | * get properly updated on disk. | |
213 | */ | |
0b86a832 CM |
214 | static void add_root_to_dirty_list(struct btrfs_root *root) |
215 | { | |
e7070be1 JB |
216 | if (test_bit(BTRFS_ROOT_DIRTY, &root->state) || |
217 | !test_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state)) | |
218 | return; | |
219 | ||
e5846fc6 | 220 | spin_lock(&root->fs_info->trans_lock); |
e7070be1 JB |
221 | if (!test_and_set_bit(BTRFS_ROOT_DIRTY, &root->state)) { |
222 | /* Want the extent tree to be the last on the list */ | |
223 | if (root->objectid == BTRFS_EXTENT_TREE_OBJECTID) | |
224 | list_move_tail(&root->dirty_list, | |
225 | &root->fs_info->dirty_cowonly_roots); | |
226 | else | |
227 | list_move(&root->dirty_list, | |
228 | &root->fs_info->dirty_cowonly_roots); | |
0b86a832 | 229 | } |
e5846fc6 | 230 | spin_unlock(&root->fs_info->trans_lock); |
0b86a832 CM |
231 | } |
232 | ||
d352ac68 CM |
233 | /* |
234 | * used by snapshot creation to make a copy of a root for a tree with | |
235 | * a given objectid. The buffer with the new root node is returned in | |
236 | * cow_ret, and this func returns zero on success or a negative error code. | |
237 | */ | |
be20aa9d CM |
238 | int btrfs_copy_root(struct btrfs_trans_handle *trans, |
239 | struct btrfs_root *root, | |
240 | struct extent_buffer *buf, | |
241 | struct extent_buffer **cow_ret, u64 new_root_objectid) | |
242 | { | |
243 | struct extent_buffer *cow; | |
be20aa9d CM |
244 | int ret = 0; |
245 | int level; | |
5d4f98a2 | 246 | struct btrfs_disk_key disk_key; |
be20aa9d | 247 | |
27cdeb70 MX |
248 | WARN_ON(test_bit(BTRFS_ROOT_REF_COWS, &root->state) && |
249 | trans->transid != root->fs_info->running_transaction->transid); | |
250 | WARN_ON(test_bit(BTRFS_ROOT_REF_COWS, &root->state) && | |
251 | trans->transid != root->last_trans); | |
be20aa9d CM |
252 | |
253 | level = btrfs_header_level(buf); | |
5d4f98a2 YZ |
254 | if (level == 0) |
255 | btrfs_item_key(buf, &disk_key, 0); | |
256 | else | |
257 | btrfs_node_key(buf, &disk_key, 0); | |
31840ae1 | 258 | |
4d75f8a9 DS |
259 | cow = btrfs_alloc_tree_block(trans, root, 0, new_root_objectid, |
260 | &disk_key, level, buf->start, 0); | |
5d4f98a2 | 261 | if (IS_ERR(cow)) |
be20aa9d CM |
262 | return PTR_ERR(cow); |
263 | ||
264 | copy_extent_buffer(cow, buf, 0, 0, cow->len); | |
265 | btrfs_set_header_bytenr(cow, cow->start); | |
266 | btrfs_set_header_generation(cow, trans->transid); | |
5d4f98a2 YZ |
267 | btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV); |
268 | btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN | | |
269 | BTRFS_HEADER_FLAG_RELOC); | |
270 | if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID) | |
271 | btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC); | |
272 | else | |
273 | btrfs_set_header_owner(cow, new_root_objectid); | |
be20aa9d | 274 | |
0a4e5586 | 275 | write_extent_buffer(cow, root->fs_info->fsid, btrfs_header_fsid(), |
2b82032c YZ |
276 | BTRFS_FSID_SIZE); |
277 | ||
be20aa9d | 278 | WARN_ON(btrfs_header_generation(buf) > trans->transid); |
5d4f98a2 | 279 | if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID) |
e339a6b0 | 280 | ret = btrfs_inc_ref(trans, root, cow, 1); |
5d4f98a2 | 281 | else |
e339a6b0 | 282 | ret = btrfs_inc_ref(trans, root, cow, 0); |
4aec2b52 | 283 | |
be20aa9d CM |
284 | if (ret) |
285 | return ret; | |
286 | ||
287 | btrfs_mark_buffer_dirty(cow); | |
288 | *cow_ret = cow; | |
289 | return 0; | |
290 | } | |
291 | ||
bd989ba3 JS |
292 | enum mod_log_op { |
293 | MOD_LOG_KEY_REPLACE, | |
294 | MOD_LOG_KEY_ADD, | |
295 | MOD_LOG_KEY_REMOVE, | |
296 | MOD_LOG_KEY_REMOVE_WHILE_FREEING, | |
297 | MOD_LOG_KEY_REMOVE_WHILE_MOVING, | |
298 | MOD_LOG_MOVE_KEYS, | |
299 | MOD_LOG_ROOT_REPLACE, | |
300 | }; | |
301 | ||
302 | struct tree_mod_move { | |
303 | int dst_slot; | |
304 | int nr_items; | |
305 | }; | |
306 | ||
307 | struct tree_mod_root { | |
308 | u64 logical; | |
309 | u8 level; | |
310 | }; | |
311 | ||
312 | struct tree_mod_elem { | |
313 | struct rb_node node; | |
314 | u64 index; /* shifted logical */ | |
097b8a7c | 315 | u64 seq; |
bd989ba3 JS |
316 | enum mod_log_op op; |
317 | ||
318 | /* this is used for MOD_LOG_KEY_* and MOD_LOG_MOVE_KEYS operations */ | |
319 | int slot; | |
320 | ||
321 | /* this is used for MOD_LOG_KEY* and MOD_LOG_ROOT_REPLACE */ | |
322 | u64 generation; | |
323 | ||
324 | /* those are used for op == MOD_LOG_KEY_{REPLACE,REMOVE} */ | |
325 | struct btrfs_disk_key key; | |
326 | u64 blockptr; | |
327 | ||
328 | /* this is used for op == MOD_LOG_MOVE_KEYS */ | |
329 | struct tree_mod_move move; | |
330 | ||
331 | /* this is used for op == MOD_LOG_ROOT_REPLACE */ | |
332 | struct tree_mod_root old_root; | |
333 | }; | |
334 | ||
097b8a7c | 335 | static inline void tree_mod_log_read_lock(struct btrfs_fs_info *fs_info) |
bd989ba3 | 336 | { |
097b8a7c | 337 | read_lock(&fs_info->tree_mod_log_lock); |
bd989ba3 JS |
338 | } |
339 | ||
097b8a7c JS |
340 | static inline void tree_mod_log_read_unlock(struct btrfs_fs_info *fs_info) |
341 | { | |
342 | read_unlock(&fs_info->tree_mod_log_lock); | |
343 | } | |
344 | ||
345 | static inline void tree_mod_log_write_lock(struct btrfs_fs_info *fs_info) | |
346 | { | |
347 | write_lock(&fs_info->tree_mod_log_lock); | |
348 | } | |
349 | ||
350 | static inline void tree_mod_log_write_unlock(struct btrfs_fs_info *fs_info) | |
351 | { | |
352 | write_unlock(&fs_info->tree_mod_log_lock); | |
353 | } | |
354 | ||
fc36ed7e | 355 | /* |
fcebe456 | 356 | * Pull a new tree mod seq number for our operation. |
fc36ed7e | 357 | */ |
fcebe456 | 358 | static inline u64 btrfs_inc_tree_mod_seq(struct btrfs_fs_info *fs_info) |
fc36ed7e JS |
359 | { |
360 | return atomic64_inc_return(&fs_info->tree_mod_seq); | |
361 | } | |
362 | ||
097b8a7c JS |
363 | /* |
364 | * This adds a new blocker to the tree mod log's blocker list if the @elem | |
365 | * passed does not already have a sequence number set. So when a caller expects | |
366 | * to record tree modifications, it should ensure to set elem->seq to zero | |
367 | * before calling btrfs_get_tree_mod_seq. | |
368 | * Returns a fresh, unused tree log modification sequence number, even if no new | |
369 | * blocker was added. | |
370 | */ | |
371 | u64 btrfs_get_tree_mod_seq(struct btrfs_fs_info *fs_info, | |
372 | struct seq_list *elem) | |
bd989ba3 | 373 | { |
097b8a7c | 374 | tree_mod_log_write_lock(fs_info); |
bd989ba3 | 375 | spin_lock(&fs_info->tree_mod_seq_lock); |
097b8a7c | 376 | if (!elem->seq) { |
fcebe456 | 377 | elem->seq = btrfs_inc_tree_mod_seq(fs_info); |
097b8a7c JS |
378 | list_add_tail(&elem->list, &fs_info->tree_mod_seq_list); |
379 | } | |
bd989ba3 | 380 | spin_unlock(&fs_info->tree_mod_seq_lock); |
097b8a7c JS |
381 | tree_mod_log_write_unlock(fs_info); |
382 | ||
fcebe456 | 383 | return elem->seq; |
bd989ba3 JS |
384 | } |
385 | ||
386 | void btrfs_put_tree_mod_seq(struct btrfs_fs_info *fs_info, | |
387 | struct seq_list *elem) | |
388 | { | |
389 | struct rb_root *tm_root; | |
390 | struct rb_node *node; | |
391 | struct rb_node *next; | |
392 | struct seq_list *cur_elem; | |
393 | struct tree_mod_elem *tm; | |
394 | u64 min_seq = (u64)-1; | |
395 | u64 seq_putting = elem->seq; | |
396 | ||
397 | if (!seq_putting) | |
398 | return; | |
399 | ||
bd989ba3 JS |
400 | spin_lock(&fs_info->tree_mod_seq_lock); |
401 | list_del(&elem->list); | |
097b8a7c | 402 | elem->seq = 0; |
bd989ba3 JS |
403 | |
404 | list_for_each_entry(cur_elem, &fs_info->tree_mod_seq_list, list) { | |
097b8a7c | 405 | if (cur_elem->seq < min_seq) { |
bd989ba3 JS |
406 | if (seq_putting > cur_elem->seq) { |
407 | /* | |
408 | * blocker with lower sequence number exists, we | |
409 | * cannot remove anything from the log | |
410 | */ | |
097b8a7c JS |
411 | spin_unlock(&fs_info->tree_mod_seq_lock); |
412 | return; | |
bd989ba3 JS |
413 | } |
414 | min_seq = cur_elem->seq; | |
415 | } | |
416 | } | |
097b8a7c JS |
417 | spin_unlock(&fs_info->tree_mod_seq_lock); |
418 | ||
bd989ba3 JS |
419 | /* |
420 | * anything that's lower than the lowest existing (read: blocked) | |
421 | * sequence number can be removed from the tree. | |
422 | */ | |
097b8a7c | 423 | tree_mod_log_write_lock(fs_info); |
bd989ba3 JS |
424 | tm_root = &fs_info->tree_mod_log; |
425 | for (node = rb_first(tm_root); node; node = next) { | |
426 | next = rb_next(node); | |
427 | tm = container_of(node, struct tree_mod_elem, node); | |
097b8a7c | 428 | if (tm->seq > min_seq) |
bd989ba3 JS |
429 | continue; |
430 | rb_erase(node, tm_root); | |
bd989ba3 JS |
431 | kfree(tm); |
432 | } | |
097b8a7c | 433 | tree_mod_log_write_unlock(fs_info); |
bd989ba3 JS |
434 | } |
435 | ||
436 | /* | |
437 | * key order of the log: | |
438 | * index -> sequence | |
439 | * | |
440 | * the index is the shifted logical of the *new* root node for root replace | |
441 | * operations, or the shifted logical of the affected block for all other | |
442 | * operations. | |
5de865ee FDBM |
443 | * |
444 | * Note: must be called with write lock (tree_mod_log_write_lock). | |
bd989ba3 JS |
445 | */ |
446 | static noinline int | |
447 | __tree_mod_log_insert(struct btrfs_fs_info *fs_info, struct tree_mod_elem *tm) | |
448 | { | |
449 | struct rb_root *tm_root; | |
450 | struct rb_node **new; | |
451 | struct rb_node *parent = NULL; | |
452 | struct tree_mod_elem *cur; | |
c8cc6341 JB |
453 | |
454 | BUG_ON(!tm); | |
455 | ||
fcebe456 | 456 | tm->seq = btrfs_inc_tree_mod_seq(fs_info); |
bd989ba3 | 457 | |
bd989ba3 JS |
458 | tm_root = &fs_info->tree_mod_log; |
459 | new = &tm_root->rb_node; | |
460 | while (*new) { | |
461 | cur = container_of(*new, struct tree_mod_elem, node); | |
462 | parent = *new; | |
463 | if (cur->index < tm->index) | |
464 | new = &((*new)->rb_left); | |
465 | else if (cur->index > tm->index) | |
466 | new = &((*new)->rb_right); | |
097b8a7c | 467 | else if (cur->seq < tm->seq) |
bd989ba3 | 468 | new = &((*new)->rb_left); |
097b8a7c | 469 | else if (cur->seq > tm->seq) |
bd989ba3 | 470 | new = &((*new)->rb_right); |
5de865ee FDBM |
471 | else |
472 | return -EEXIST; | |
bd989ba3 JS |
473 | } |
474 | ||
475 | rb_link_node(&tm->node, parent, new); | |
476 | rb_insert_color(&tm->node, tm_root); | |
5de865ee | 477 | return 0; |
bd989ba3 JS |
478 | } |
479 | ||
097b8a7c JS |
480 | /* |
481 | * Determines if logging can be omitted. Returns 1 if it can. Otherwise, it | |
482 | * returns zero with the tree_mod_log_lock acquired. The caller must hold | |
483 | * this until all tree mod log insertions are recorded in the rb tree and then | |
484 | * call tree_mod_log_write_unlock() to release. | |
485 | */ | |
e9b7fd4d JS |
486 | static inline int tree_mod_dont_log(struct btrfs_fs_info *fs_info, |
487 | struct extent_buffer *eb) { | |
488 | smp_mb(); | |
489 | if (list_empty(&(fs_info)->tree_mod_seq_list)) | |
490 | return 1; | |
097b8a7c JS |
491 | if (eb && btrfs_header_level(eb) == 0) |
492 | return 1; | |
5de865ee FDBM |
493 | |
494 | tree_mod_log_write_lock(fs_info); | |
495 | if (list_empty(&(fs_info)->tree_mod_seq_list)) { | |
496 | tree_mod_log_write_unlock(fs_info); | |
497 | return 1; | |
498 | } | |
499 | ||
e9b7fd4d JS |
500 | return 0; |
501 | } | |
502 | ||
5de865ee FDBM |
503 | /* Similar to tree_mod_dont_log, but doesn't acquire any locks. */ |
504 | static inline int tree_mod_need_log(const struct btrfs_fs_info *fs_info, | |
505 | struct extent_buffer *eb) | |
506 | { | |
507 | smp_mb(); | |
508 | if (list_empty(&(fs_info)->tree_mod_seq_list)) | |
509 | return 0; | |
510 | if (eb && btrfs_header_level(eb) == 0) | |
511 | return 0; | |
512 | ||
513 | return 1; | |
514 | } | |
515 | ||
516 | static struct tree_mod_elem * | |
517 | alloc_tree_mod_elem(struct extent_buffer *eb, int slot, | |
518 | enum mod_log_op op, gfp_t flags) | |
bd989ba3 | 519 | { |
097b8a7c | 520 | struct tree_mod_elem *tm; |
bd989ba3 | 521 | |
c8cc6341 JB |
522 | tm = kzalloc(sizeof(*tm), flags); |
523 | if (!tm) | |
5de865ee | 524 | return NULL; |
bd989ba3 JS |
525 | |
526 | tm->index = eb->start >> PAGE_CACHE_SHIFT; | |
527 | if (op != MOD_LOG_KEY_ADD) { | |
528 | btrfs_node_key(eb, &tm->key, slot); | |
529 | tm->blockptr = btrfs_node_blockptr(eb, slot); | |
530 | } | |
531 | tm->op = op; | |
532 | tm->slot = slot; | |
533 | tm->generation = btrfs_node_ptr_generation(eb, slot); | |
5de865ee | 534 | RB_CLEAR_NODE(&tm->node); |
bd989ba3 | 535 | |
5de865ee | 536 | return tm; |
097b8a7c JS |
537 | } |
538 | ||
539 | static noinline int | |
c8cc6341 JB |
540 | tree_mod_log_insert_key(struct btrfs_fs_info *fs_info, |
541 | struct extent_buffer *eb, int slot, | |
542 | enum mod_log_op op, gfp_t flags) | |
097b8a7c | 543 | { |
5de865ee FDBM |
544 | struct tree_mod_elem *tm; |
545 | int ret; | |
546 | ||
547 | if (!tree_mod_need_log(fs_info, eb)) | |
548 | return 0; | |
549 | ||
550 | tm = alloc_tree_mod_elem(eb, slot, op, flags); | |
551 | if (!tm) | |
552 | return -ENOMEM; | |
553 | ||
554 | if (tree_mod_dont_log(fs_info, eb)) { | |
555 | kfree(tm); | |
097b8a7c | 556 | return 0; |
5de865ee FDBM |
557 | } |
558 | ||
559 | ret = __tree_mod_log_insert(fs_info, tm); | |
560 | tree_mod_log_write_unlock(fs_info); | |
561 | if (ret) | |
562 | kfree(tm); | |
097b8a7c | 563 | |
5de865ee | 564 | return ret; |
097b8a7c JS |
565 | } |
566 | ||
bd989ba3 JS |
567 | static noinline int |
568 | tree_mod_log_insert_move(struct btrfs_fs_info *fs_info, | |
569 | struct extent_buffer *eb, int dst_slot, int src_slot, | |
570 | int nr_items, gfp_t flags) | |
571 | { | |
5de865ee FDBM |
572 | struct tree_mod_elem *tm = NULL; |
573 | struct tree_mod_elem **tm_list = NULL; | |
574 | int ret = 0; | |
bd989ba3 | 575 | int i; |
5de865ee | 576 | int locked = 0; |
bd989ba3 | 577 | |
5de865ee | 578 | if (!tree_mod_need_log(fs_info, eb)) |
f395694c | 579 | return 0; |
bd989ba3 | 580 | |
31e818fe | 581 | tm_list = kcalloc(nr_items, sizeof(struct tree_mod_elem *), flags); |
5de865ee FDBM |
582 | if (!tm_list) |
583 | return -ENOMEM; | |
584 | ||
585 | tm = kzalloc(sizeof(*tm), flags); | |
586 | if (!tm) { | |
587 | ret = -ENOMEM; | |
588 | goto free_tms; | |
589 | } | |
590 | ||
591 | tm->index = eb->start >> PAGE_CACHE_SHIFT; | |
592 | tm->slot = src_slot; | |
593 | tm->move.dst_slot = dst_slot; | |
594 | tm->move.nr_items = nr_items; | |
595 | tm->op = MOD_LOG_MOVE_KEYS; | |
596 | ||
597 | for (i = 0; i + dst_slot < src_slot && i < nr_items; i++) { | |
598 | tm_list[i] = alloc_tree_mod_elem(eb, i + dst_slot, | |
599 | MOD_LOG_KEY_REMOVE_WHILE_MOVING, flags); | |
600 | if (!tm_list[i]) { | |
601 | ret = -ENOMEM; | |
602 | goto free_tms; | |
603 | } | |
604 | } | |
605 | ||
606 | if (tree_mod_dont_log(fs_info, eb)) | |
607 | goto free_tms; | |
608 | locked = 1; | |
609 | ||
01763a2e JS |
610 | /* |
611 | * When we override something during the move, we log these removals. | |
612 | * This can only happen when we move towards the beginning of the | |
613 | * buffer, i.e. dst_slot < src_slot. | |
614 | */ | |
bd989ba3 | 615 | for (i = 0; i + dst_slot < src_slot && i < nr_items; i++) { |
5de865ee FDBM |
616 | ret = __tree_mod_log_insert(fs_info, tm_list[i]); |
617 | if (ret) | |
618 | goto free_tms; | |
bd989ba3 JS |
619 | } |
620 | ||
5de865ee FDBM |
621 | ret = __tree_mod_log_insert(fs_info, tm); |
622 | if (ret) | |
623 | goto free_tms; | |
624 | tree_mod_log_write_unlock(fs_info); | |
625 | kfree(tm_list); | |
f395694c | 626 | |
5de865ee FDBM |
627 | return 0; |
628 | free_tms: | |
629 | for (i = 0; i < nr_items; i++) { | |
630 | if (tm_list[i] && !RB_EMPTY_NODE(&tm_list[i]->node)) | |
631 | rb_erase(&tm_list[i]->node, &fs_info->tree_mod_log); | |
632 | kfree(tm_list[i]); | |
633 | } | |
634 | if (locked) | |
635 | tree_mod_log_write_unlock(fs_info); | |
636 | kfree(tm_list); | |
637 | kfree(tm); | |
bd989ba3 | 638 | |
5de865ee | 639 | return ret; |
bd989ba3 JS |
640 | } |
641 | ||
5de865ee FDBM |
642 | static inline int |
643 | __tree_mod_log_free_eb(struct btrfs_fs_info *fs_info, | |
644 | struct tree_mod_elem **tm_list, | |
645 | int nritems) | |
097b8a7c | 646 | { |
5de865ee | 647 | int i, j; |
097b8a7c JS |
648 | int ret; |
649 | ||
097b8a7c | 650 | for (i = nritems - 1; i >= 0; i--) { |
5de865ee FDBM |
651 | ret = __tree_mod_log_insert(fs_info, tm_list[i]); |
652 | if (ret) { | |
653 | for (j = nritems - 1; j > i; j--) | |
654 | rb_erase(&tm_list[j]->node, | |
655 | &fs_info->tree_mod_log); | |
656 | return ret; | |
657 | } | |
097b8a7c | 658 | } |
5de865ee FDBM |
659 | |
660 | return 0; | |
097b8a7c JS |
661 | } |
662 | ||
bd989ba3 JS |
663 | static noinline int |
664 | tree_mod_log_insert_root(struct btrfs_fs_info *fs_info, | |
665 | struct extent_buffer *old_root, | |
90f8d62e JS |
666 | struct extent_buffer *new_root, gfp_t flags, |
667 | int log_removal) | |
bd989ba3 | 668 | { |
5de865ee FDBM |
669 | struct tree_mod_elem *tm = NULL; |
670 | struct tree_mod_elem **tm_list = NULL; | |
671 | int nritems = 0; | |
672 | int ret = 0; | |
673 | int i; | |
bd989ba3 | 674 | |
5de865ee | 675 | if (!tree_mod_need_log(fs_info, NULL)) |
097b8a7c JS |
676 | return 0; |
677 | ||
5de865ee FDBM |
678 | if (log_removal && btrfs_header_level(old_root) > 0) { |
679 | nritems = btrfs_header_nritems(old_root); | |
31e818fe | 680 | tm_list = kcalloc(nritems, sizeof(struct tree_mod_elem *), |
5de865ee FDBM |
681 | flags); |
682 | if (!tm_list) { | |
683 | ret = -ENOMEM; | |
684 | goto free_tms; | |
685 | } | |
686 | for (i = 0; i < nritems; i++) { | |
687 | tm_list[i] = alloc_tree_mod_elem(old_root, i, | |
688 | MOD_LOG_KEY_REMOVE_WHILE_FREEING, flags); | |
689 | if (!tm_list[i]) { | |
690 | ret = -ENOMEM; | |
691 | goto free_tms; | |
692 | } | |
693 | } | |
694 | } | |
d9abbf1c | 695 | |
c8cc6341 | 696 | tm = kzalloc(sizeof(*tm), flags); |
5de865ee FDBM |
697 | if (!tm) { |
698 | ret = -ENOMEM; | |
699 | goto free_tms; | |
700 | } | |
bd989ba3 JS |
701 | |
702 | tm->index = new_root->start >> PAGE_CACHE_SHIFT; | |
703 | tm->old_root.logical = old_root->start; | |
704 | tm->old_root.level = btrfs_header_level(old_root); | |
705 | tm->generation = btrfs_header_generation(old_root); | |
706 | tm->op = MOD_LOG_ROOT_REPLACE; | |
707 | ||
5de865ee FDBM |
708 | if (tree_mod_dont_log(fs_info, NULL)) |
709 | goto free_tms; | |
710 | ||
711 | if (tm_list) | |
712 | ret = __tree_mod_log_free_eb(fs_info, tm_list, nritems); | |
713 | if (!ret) | |
714 | ret = __tree_mod_log_insert(fs_info, tm); | |
715 | ||
716 | tree_mod_log_write_unlock(fs_info); | |
717 | if (ret) | |
718 | goto free_tms; | |
719 | kfree(tm_list); | |
720 | ||
721 | return ret; | |
722 | ||
723 | free_tms: | |
724 | if (tm_list) { | |
725 | for (i = 0; i < nritems; i++) | |
726 | kfree(tm_list[i]); | |
727 | kfree(tm_list); | |
728 | } | |
729 | kfree(tm); | |
730 | ||
731 | return ret; | |
bd989ba3 JS |
732 | } |
733 | ||
734 | static struct tree_mod_elem * | |
735 | __tree_mod_log_search(struct btrfs_fs_info *fs_info, u64 start, u64 min_seq, | |
736 | int smallest) | |
737 | { | |
738 | struct rb_root *tm_root; | |
739 | struct rb_node *node; | |
740 | struct tree_mod_elem *cur = NULL; | |
741 | struct tree_mod_elem *found = NULL; | |
742 | u64 index = start >> PAGE_CACHE_SHIFT; | |
743 | ||
097b8a7c | 744 | tree_mod_log_read_lock(fs_info); |
bd989ba3 JS |
745 | tm_root = &fs_info->tree_mod_log; |
746 | node = tm_root->rb_node; | |
747 | while (node) { | |
748 | cur = container_of(node, struct tree_mod_elem, node); | |
749 | if (cur->index < index) { | |
750 | node = node->rb_left; | |
751 | } else if (cur->index > index) { | |
752 | node = node->rb_right; | |
097b8a7c | 753 | } else if (cur->seq < min_seq) { |
bd989ba3 JS |
754 | node = node->rb_left; |
755 | } else if (!smallest) { | |
756 | /* we want the node with the highest seq */ | |
757 | if (found) | |
097b8a7c | 758 | BUG_ON(found->seq > cur->seq); |
bd989ba3 JS |
759 | found = cur; |
760 | node = node->rb_left; | |
097b8a7c | 761 | } else if (cur->seq > min_seq) { |
bd989ba3 JS |
762 | /* we want the node with the smallest seq */ |
763 | if (found) | |
097b8a7c | 764 | BUG_ON(found->seq < cur->seq); |
bd989ba3 JS |
765 | found = cur; |
766 | node = node->rb_right; | |
767 | } else { | |
768 | found = cur; | |
769 | break; | |
770 | } | |
771 | } | |
097b8a7c | 772 | tree_mod_log_read_unlock(fs_info); |
bd989ba3 JS |
773 | |
774 | return found; | |
775 | } | |
776 | ||
777 | /* | |
778 | * this returns the element from the log with the smallest time sequence | |
779 | * value that's in the log (the oldest log item). any element with a time | |
780 | * sequence lower than min_seq will be ignored. | |
781 | */ | |
782 | static struct tree_mod_elem * | |
783 | tree_mod_log_search_oldest(struct btrfs_fs_info *fs_info, u64 start, | |
784 | u64 min_seq) | |
785 | { | |
786 | return __tree_mod_log_search(fs_info, start, min_seq, 1); | |
787 | } | |
788 | ||
789 | /* | |
790 | * this returns the element from the log with the largest time sequence | |
791 | * value that's in the log (the most recent log item). any element with | |
792 | * a time sequence lower than min_seq will be ignored. | |
793 | */ | |
794 | static struct tree_mod_elem * | |
795 | tree_mod_log_search(struct btrfs_fs_info *fs_info, u64 start, u64 min_seq) | |
796 | { | |
797 | return __tree_mod_log_search(fs_info, start, min_seq, 0); | |
798 | } | |
799 | ||
5de865ee | 800 | static noinline int |
bd989ba3 JS |
801 | tree_mod_log_eb_copy(struct btrfs_fs_info *fs_info, struct extent_buffer *dst, |
802 | struct extent_buffer *src, unsigned long dst_offset, | |
90f8d62e | 803 | unsigned long src_offset, int nr_items) |
bd989ba3 | 804 | { |
5de865ee FDBM |
805 | int ret = 0; |
806 | struct tree_mod_elem **tm_list = NULL; | |
807 | struct tree_mod_elem **tm_list_add, **tm_list_rem; | |
bd989ba3 | 808 | int i; |
5de865ee | 809 | int locked = 0; |
bd989ba3 | 810 | |
5de865ee FDBM |
811 | if (!tree_mod_need_log(fs_info, NULL)) |
812 | return 0; | |
bd989ba3 | 813 | |
c8cc6341 | 814 | if (btrfs_header_level(dst) == 0 && btrfs_header_level(src) == 0) |
5de865ee FDBM |
815 | return 0; |
816 | ||
31e818fe | 817 | tm_list = kcalloc(nr_items * 2, sizeof(struct tree_mod_elem *), |
5de865ee FDBM |
818 | GFP_NOFS); |
819 | if (!tm_list) | |
820 | return -ENOMEM; | |
bd989ba3 | 821 | |
5de865ee FDBM |
822 | tm_list_add = tm_list; |
823 | tm_list_rem = tm_list + nr_items; | |
bd989ba3 | 824 | for (i = 0; i < nr_items; i++) { |
5de865ee FDBM |
825 | tm_list_rem[i] = alloc_tree_mod_elem(src, i + src_offset, |
826 | MOD_LOG_KEY_REMOVE, GFP_NOFS); | |
827 | if (!tm_list_rem[i]) { | |
828 | ret = -ENOMEM; | |
829 | goto free_tms; | |
830 | } | |
831 | ||
832 | tm_list_add[i] = alloc_tree_mod_elem(dst, i + dst_offset, | |
833 | MOD_LOG_KEY_ADD, GFP_NOFS); | |
834 | if (!tm_list_add[i]) { | |
835 | ret = -ENOMEM; | |
836 | goto free_tms; | |
837 | } | |
838 | } | |
839 | ||
840 | if (tree_mod_dont_log(fs_info, NULL)) | |
841 | goto free_tms; | |
842 | locked = 1; | |
843 | ||
844 | for (i = 0; i < nr_items; i++) { | |
845 | ret = __tree_mod_log_insert(fs_info, tm_list_rem[i]); | |
846 | if (ret) | |
847 | goto free_tms; | |
848 | ret = __tree_mod_log_insert(fs_info, tm_list_add[i]); | |
849 | if (ret) | |
850 | goto free_tms; | |
bd989ba3 | 851 | } |
5de865ee FDBM |
852 | |
853 | tree_mod_log_write_unlock(fs_info); | |
854 | kfree(tm_list); | |
855 | ||
856 | return 0; | |
857 | ||
858 | free_tms: | |
859 | for (i = 0; i < nr_items * 2; i++) { | |
860 | if (tm_list[i] && !RB_EMPTY_NODE(&tm_list[i]->node)) | |
861 | rb_erase(&tm_list[i]->node, &fs_info->tree_mod_log); | |
862 | kfree(tm_list[i]); | |
863 | } | |
864 | if (locked) | |
865 | tree_mod_log_write_unlock(fs_info); | |
866 | kfree(tm_list); | |
867 | ||
868 | return ret; | |
bd989ba3 JS |
869 | } |
870 | ||
871 | static inline void | |
872 | tree_mod_log_eb_move(struct btrfs_fs_info *fs_info, struct extent_buffer *dst, | |
873 | int dst_offset, int src_offset, int nr_items) | |
874 | { | |
875 | int ret; | |
876 | ret = tree_mod_log_insert_move(fs_info, dst, dst_offset, src_offset, | |
877 | nr_items, GFP_NOFS); | |
878 | BUG_ON(ret < 0); | |
879 | } | |
880 | ||
097b8a7c | 881 | static noinline void |
bd989ba3 | 882 | tree_mod_log_set_node_key(struct btrfs_fs_info *fs_info, |
32adf090 | 883 | struct extent_buffer *eb, int slot, int atomic) |
bd989ba3 JS |
884 | { |
885 | int ret; | |
886 | ||
78357766 | 887 | ret = tree_mod_log_insert_key(fs_info, eb, slot, |
c8cc6341 JB |
888 | MOD_LOG_KEY_REPLACE, |
889 | atomic ? GFP_ATOMIC : GFP_NOFS); | |
bd989ba3 JS |
890 | BUG_ON(ret < 0); |
891 | } | |
892 | ||
5de865ee | 893 | static noinline int |
097b8a7c | 894 | tree_mod_log_free_eb(struct btrfs_fs_info *fs_info, struct extent_buffer *eb) |
bd989ba3 | 895 | { |
5de865ee FDBM |
896 | struct tree_mod_elem **tm_list = NULL; |
897 | int nritems = 0; | |
898 | int i; | |
899 | int ret = 0; | |
900 | ||
901 | if (btrfs_header_level(eb) == 0) | |
902 | return 0; | |
903 | ||
904 | if (!tree_mod_need_log(fs_info, NULL)) | |
905 | return 0; | |
906 | ||
907 | nritems = btrfs_header_nritems(eb); | |
31e818fe | 908 | tm_list = kcalloc(nritems, sizeof(struct tree_mod_elem *), GFP_NOFS); |
5de865ee FDBM |
909 | if (!tm_list) |
910 | return -ENOMEM; | |
911 | ||
912 | for (i = 0; i < nritems; i++) { | |
913 | tm_list[i] = alloc_tree_mod_elem(eb, i, | |
914 | MOD_LOG_KEY_REMOVE_WHILE_FREEING, GFP_NOFS); | |
915 | if (!tm_list[i]) { | |
916 | ret = -ENOMEM; | |
917 | goto free_tms; | |
918 | } | |
919 | } | |
920 | ||
e9b7fd4d | 921 | if (tree_mod_dont_log(fs_info, eb)) |
5de865ee FDBM |
922 | goto free_tms; |
923 | ||
924 | ret = __tree_mod_log_free_eb(fs_info, tm_list, nritems); | |
925 | tree_mod_log_write_unlock(fs_info); | |
926 | if (ret) | |
927 | goto free_tms; | |
928 | kfree(tm_list); | |
929 | ||
930 | return 0; | |
931 | ||
932 | free_tms: | |
933 | for (i = 0; i < nritems; i++) | |
934 | kfree(tm_list[i]); | |
935 | kfree(tm_list); | |
936 | ||
937 | return ret; | |
bd989ba3 JS |
938 | } |
939 | ||
097b8a7c | 940 | static noinline void |
bd989ba3 | 941 | tree_mod_log_set_root_pointer(struct btrfs_root *root, |
90f8d62e JS |
942 | struct extent_buffer *new_root_node, |
943 | int log_removal) | |
bd989ba3 JS |
944 | { |
945 | int ret; | |
bd989ba3 | 946 | ret = tree_mod_log_insert_root(root->fs_info, root->node, |
90f8d62e | 947 | new_root_node, GFP_NOFS, log_removal); |
bd989ba3 JS |
948 | BUG_ON(ret < 0); |
949 | } | |
950 | ||
5d4f98a2 YZ |
951 | /* |
952 | * check if the tree block can be shared by multiple trees | |
953 | */ | |
954 | int btrfs_block_can_be_shared(struct btrfs_root *root, | |
955 | struct extent_buffer *buf) | |
956 | { | |
957 | /* | |
958 | * Tree blocks not in refernece counted trees and tree roots | |
959 | * are never shared. If a block was allocated after the last | |
960 | * snapshot and the block was not allocated by tree relocation, | |
961 | * we know the block is not shared. | |
962 | */ | |
27cdeb70 | 963 | if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) && |
5d4f98a2 YZ |
964 | buf != root->node && buf != root->commit_root && |
965 | (btrfs_header_generation(buf) <= | |
966 | btrfs_root_last_snapshot(&root->root_item) || | |
967 | btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC))) | |
968 | return 1; | |
969 | #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 | |
27cdeb70 | 970 | if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) && |
5d4f98a2 YZ |
971 | btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) |
972 | return 1; | |
973 | #endif | |
974 | return 0; | |
975 | } | |
976 | ||
977 | static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans, | |
978 | struct btrfs_root *root, | |
979 | struct extent_buffer *buf, | |
f0486c68 YZ |
980 | struct extent_buffer *cow, |
981 | int *last_ref) | |
5d4f98a2 YZ |
982 | { |
983 | u64 refs; | |
984 | u64 owner; | |
985 | u64 flags; | |
986 | u64 new_flags = 0; | |
987 | int ret; | |
988 | ||
989 | /* | |
990 | * Backrefs update rules: | |
991 | * | |
992 | * Always use full backrefs for extent pointers in tree block | |
993 | * allocated by tree relocation. | |
994 | * | |
995 | * If a shared tree block is no longer referenced by its owner | |
996 | * tree (btrfs_header_owner(buf) == root->root_key.objectid), | |
997 | * use full backrefs for extent pointers in tree block. | |
998 | * | |
999 | * If a tree block is been relocating | |
1000 | * (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID), | |
1001 | * use full backrefs for extent pointers in tree block. | |
1002 | * The reason for this is some operations (such as drop tree) | |
1003 | * are only allowed for blocks use full backrefs. | |
1004 | */ | |
1005 | ||
1006 | if (btrfs_block_can_be_shared(root, buf)) { | |
1007 | ret = btrfs_lookup_extent_info(trans, root, buf->start, | |
3173a18f JB |
1008 | btrfs_header_level(buf), 1, |
1009 | &refs, &flags); | |
be1a5564 MF |
1010 | if (ret) |
1011 | return ret; | |
e5df9573 MF |
1012 | if (refs == 0) { |
1013 | ret = -EROFS; | |
1014 | btrfs_std_error(root->fs_info, ret); | |
1015 | return ret; | |
1016 | } | |
5d4f98a2 YZ |
1017 | } else { |
1018 | refs = 1; | |
1019 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID || | |
1020 | btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) | |
1021 | flags = BTRFS_BLOCK_FLAG_FULL_BACKREF; | |
1022 | else | |
1023 | flags = 0; | |
1024 | } | |
1025 | ||
1026 | owner = btrfs_header_owner(buf); | |
1027 | BUG_ON(owner == BTRFS_TREE_RELOC_OBJECTID && | |
1028 | !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)); | |
1029 | ||
1030 | if (refs > 1) { | |
1031 | if ((owner == root->root_key.objectid || | |
1032 | root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) && | |
1033 | !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)) { | |
e339a6b0 | 1034 | ret = btrfs_inc_ref(trans, root, buf, 1); |
79787eaa | 1035 | BUG_ON(ret); /* -ENOMEM */ |
5d4f98a2 YZ |
1036 | |
1037 | if (root->root_key.objectid == | |
1038 | BTRFS_TREE_RELOC_OBJECTID) { | |
e339a6b0 | 1039 | ret = btrfs_dec_ref(trans, root, buf, 0); |
79787eaa | 1040 | BUG_ON(ret); /* -ENOMEM */ |
e339a6b0 | 1041 | ret = btrfs_inc_ref(trans, root, cow, 1); |
79787eaa | 1042 | BUG_ON(ret); /* -ENOMEM */ |
5d4f98a2 YZ |
1043 | } |
1044 | new_flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF; | |
1045 | } else { | |
1046 | ||
1047 | if (root->root_key.objectid == | |
1048 | BTRFS_TREE_RELOC_OBJECTID) | |
e339a6b0 | 1049 | ret = btrfs_inc_ref(trans, root, cow, 1); |
5d4f98a2 | 1050 | else |
e339a6b0 | 1051 | ret = btrfs_inc_ref(trans, root, cow, 0); |
79787eaa | 1052 | BUG_ON(ret); /* -ENOMEM */ |
5d4f98a2 YZ |
1053 | } |
1054 | if (new_flags != 0) { | |
b1c79e09 JB |
1055 | int level = btrfs_header_level(buf); |
1056 | ||
5d4f98a2 YZ |
1057 | ret = btrfs_set_disk_extent_flags(trans, root, |
1058 | buf->start, | |
1059 | buf->len, | |
b1c79e09 | 1060 | new_flags, level, 0); |
be1a5564 MF |
1061 | if (ret) |
1062 | return ret; | |
5d4f98a2 YZ |
1063 | } |
1064 | } else { | |
1065 | if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF) { | |
1066 | if (root->root_key.objectid == | |
1067 | BTRFS_TREE_RELOC_OBJECTID) | |
e339a6b0 | 1068 | ret = btrfs_inc_ref(trans, root, cow, 1); |
5d4f98a2 | 1069 | else |
e339a6b0 | 1070 | ret = btrfs_inc_ref(trans, root, cow, 0); |
79787eaa | 1071 | BUG_ON(ret); /* -ENOMEM */ |
e339a6b0 | 1072 | ret = btrfs_dec_ref(trans, root, buf, 1); |
79787eaa | 1073 | BUG_ON(ret); /* -ENOMEM */ |
5d4f98a2 | 1074 | } |
01d58472 | 1075 | clean_tree_block(trans, root->fs_info, buf); |
f0486c68 | 1076 | *last_ref = 1; |
5d4f98a2 YZ |
1077 | } |
1078 | return 0; | |
1079 | } | |
1080 | ||
d352ac68 | 1081 | /* |
d397712b CM |
1082 | * does the dirty work in cow of a single block. The parent block (if |
1083 | * supplied) is updated to point to the new cow copy. The new buffer is marked | |
1084 | * dirty and returned locked. If you modify the block it needs to be marked | |
1085 | * dirty again. | |
d352ac68 CM |
1086 | * |
1087 | * search_start -- an allocation hint for the new block | |
1088 | * | |
d397712b CM |
1089 | * empty_size -- a hint that you plan on doing more cow. This is the size in |
1090 | * bytes the allocator should try to find free next to the block it returns. | |
1091 | * This is just a hint and may be ignored by the allocator. | |
d352ac68 | 1092 | */ |
d397712b | 1093 | static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans, |
5f39d397 CM |
1094 | struct btrfs_root *root, |
1095 | struct extent_buffer *buf, | |
1096 | struct extent_buffer *parent, int parent_slot, | |
1097 | struct extent_buffer **cow_ret, | |
9fa8cfe7 | 1098 | u64 search_start, u64 empty_size) |
02217ed2 | 1099 | { |
5d4f98a2 | 1100 | struct btrfs_disk_key disk_key; |
5f39d397 | 1101 | struct extent_buffer *cow; |
be1a5564 | 1102 | int level, ret; |
f0486c68 | 1103 | int last_ref = 0; |
925baedd | 1104 | int unlock_orig = 0; |
5d4f98a2 | 1105 | u64 parent_start; |
7bb86316 | 1106 | |
925baedd CM |
1107 | if (*cow_ret == buf) |
1108 | unlock_orig = 1; | |
1109 | ||
b9447ef8 | 1110 | btrfs_assert_tree_locked(buf); |
925baedd | 1111 | |
27cdeb70 MX |
1112 | WARN_ON(test_bit(BTRFS_ROOT_REF_COWS, &root->state) && |
1113 | trans->transid != root->fs_info->running_transaction->transid); | |
1114 | WARN_ON(test_bit(BTRFS_ROOT_REF_COWS, &root->state) && | |
1115 | trans->transid != root->last_trans); | |
5f39d397 | 1116 | |
7bb86316 | 1117 | level = btrfs_header_level(buf); |
31840ae1 | 1118 | |
5d4f98a2 YZ |
1119 | if (level == 0) |
1120 | btrfs_item_key(buf, &disk_key, 0); | |
1121 | else | |
1122 | btrfs_node_key(buf, &disk_key, 0); | |
1123 | ||
1124 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) { | |
1125 | if (parent) | |
1126 | parent_start = parent->start; | |
1127 | else | |
1128 | parent_start = 0; | |
1129 | } else | |
1130 | parent_start = 0; | |
1131 | ||
4d75f8a9 DS |
1132 | cow = btrfs_alloc_tree_block(trans, root, parent_start, |
1133 | root->root_key.objectid, &disk_key, level, | |
1134 | search_start, empty_size); | |
54aa1f4d CM |
1135 | if (IS_ERR(cow)) |
1136 | return PTR_ERR(cow); | |
6702ed49 | 1137 | |
b4ce94de CM |
1138 | /* cow is set to blocking by btrfs_init_new_buffer */ |
1139 | ||
5f39d397 | 1140 | copy_extent_buffer(cow, buf, 0, 0, cow->len); |
db94535d | 1141 | btrfs_set_header_bytenr(cow, cow->start); |
5f39d397 | 1142 | btrfs_set_header_generation(cow, trans->transid); |
5d4f98a2 YZ |
1143 | btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV); |
1144 | btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN | | |
1145 | BTRFS_HEADER_FLAG_RELOC); | |
1146 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) | |
1147 | btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC); | |
1148 | else | |
1149 | btrfs_set_header_owner(cow, root->root_key.objectid); | |
6702ed49 | 1150 | |
0a4e5586 | 1151 | write_extent_buffer(cow, root->fs_info->fsid, btrfs_header_fsid(), |
2b82032c YZ |
1152 | BTRFS_FSID_SIZE); |
1153 | ||
be1a5564 | 1154 | ret = update_ref_for_cow(trans, root, buf, cow, &last_ref); |
b68dc2a9 | 1155 | if (ret) { |
79787eaa | 1156 | btrfs_abort_transaction(trans, root, ret); |
b68dc2a9 MF |
1157 | return ret; |
1158 | } | |
1a40e23b | 1159 | |
27cdeb70 | 1160 | if (test_bit(BTRFS_ROOT_REF_COWS, &root->state)) { |
83d4cfd4 JB |
1161 | ret = btrfs_reloc_cow_block(trans, root, buf, cow); |
1162 | if (ret) | |
1163 | return ret; | |
1164 | } | |
3fd0a558 | 1165 | |
02217ed2 | 1166 | if (buf == root->node) { |
925baedd | 1167 | WARN_ON(parent && parent != buf); |
5d4f98a2 YZ |
1168 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID || |
1169 | btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) | |
1170 | parent_start = buf->start; | |
1171 | else | |
1172 | parent_start = 0; | |
925baedd | 1173 | |
5f39d397 | 1174 | extent_buffer_get(cow); |
90f8d62e | 1175 | tree_mod_log_set_root_pointer(root, cow, 1); |
240f62c8 | 1176 | rcu_assign_pointer(root->node, cow); |
925baedd | 1177 | |
f0486c68 | 1178 | btrfs_free_tree_block(trans, root, buf, parent_start, |
5581a51a | 1179 | last_ref); |
5f39d397 | 1180 | free_extent_buffer(buf); |
0b86a832 | 1181 | add_root_to_dirty_list(root); |
02217ed2 | 1182 | } else { |
5d4f98a2 YZ |
1183 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) |
1184 | parent_start = parent->start; | |
1185 | else | |
1186 | parent_start = 0; | |
1187 | ||
1188 | WARN_ON(trans->transid != btrfs_header_generation(parent)); | |
f230475e | 1189 | tree_mod_log_insert_key(root->fs_info, parent, parent_slot, |
c8cc6341 | 1190 | MOD_LOG_KEY_REPLACE, GFP_NOFS); |
5f39d397 | 1191 | btrfs_set_node_blockptr(parent, parent_slot, |
db94535d | 1192 | cow->start); |
74493f7a CM |
1193 | btrfs_set_node_ptr_generation(parent, parent_slot, |
1194 | trans->transid); | |
d6025579 | 1195 | btrfs_mark_buffer_dirty(parent); |
5de865ee FDBM |
1196 | if (last_ref) { |
1197 | ret = tree_mod_log_free_eb(root->fs_info, buf); | |
1198 | if (ret) { | |
1199 | btrfs_abort_transaction(trans, root, ret); | |
1200 | return ret; | |
1201 | } | |
1202 | } | |
f0486c68 | 1203 | btrfs_free_tree_block(trans, root, buf, parent_start, |
5581a51a | 1204 | last_ref); |
02217ed2 | 1205 | } |
925baedd CM |
1206 | if (unlock_orig) |
1207 | btrfs_tree_unlock(buf); | |
3083ee2e | 1208 | free_extent_buffer_stale(buf); |
ccd467d6 | 1209 | btrfs_mark_buffer_dirty(cow); |
2c90e5d6 | 1210 | *cow_ret = cow; |
02217ed2 CM |
1211 | return 0; |
1212 | } | |
1213 | ||
5d9e75c4 JS |
1214 | /* |
1215 | * returns the logical address of the oldest predecessor of the given root. | |
1216 | * entries older than time_seq are ignored. | |
1217 | */ | |
1218 | static struct tree_mod_elem * | |
1219 | __tree_mod_log_oldest_root(struct btrfs_fs_info *fs_info, | |
30b0463a | 1220 | struct extent_buffer *eb_root, u64 time_seq) |
5d9e75c4 JS |
1221 | { |
1222 | struct tree_mod_elem *tm; | |
1223 | struct tree_mod_elem *found = NULL; | |
30b0463a | 1224 | u64 root_logical = eb_root->start; |
5d9e75c4 JS |
1225 | int looped = 0; |
1226 | ||
1227 | if (!time_seq) | |
35a3621b | 1228 | return NULL; |
5d9e75c4 JS |
1229 | |
1230 | /* | |
1231 | * the very last operation that's logged for a root is the replacement | |
1232 | * operation (if it is replaced at all). this has the index of the *new* | |
1233 | * root, making it the very first operation that's logged for this root. | |
1234 | */ | |
1235 | while (1) { | |
1236 | tm = tree_mod_log_search_oldest(fs_info, root_logical, | |
1237 | time_seq); | |
1238 | if (!looped && !tm) | |
35a3621b | 1239 | return NULL; |
5d9e75c4 | 1240 | /* |
28da9fb4 JS |
1241 | * if there are no tree operation for the oldest root, we simply |
1242 | * return it. this should only happen if that (old) root is at | |
1243 | * level 0. | |
5d9e75c4 | 1244 | */ |
28da9fb4 JS |
1245 | if (!tm) |
1246 | break; | |
5d9e75c4 | 1247 | |
28da9fb4 JS |
1248 | /* |
1249 | * if there's an operation that's not a root replacement, we | |
1250 | * found the oldest version of our root. normally, we'll find a | |
1251 | * MOD_LOG_KEY_REMOVE_WHILE_FREEING operation here. | |
1252 | */ | |
5d9e75c4 JS |
1253 | if (tm->op != MOD_LOG_ROOT_REPLACE) |
1254 | break; | |
1255 | ||
1256 | found = tm; | |
1257 | root_logical = tm->old_root.logical; | |
5d9e75c4 JS |
1258 | looped = 1; |
1259 | } | |
1260 | ||
a95236d9 JS |
1261 | /* if there's no old root to return, return what we found instead */ |
1262 | if (!found) | |
1263 | found = tm; | |
1264 | ||
5d9e75c4 JS |
1265 | return found; |
1266 | } | |
1267 | ||
1268 | /* | |
1269 | * tm is a pointer to the first operation to rewind within eb. then, all | |
1270 | * previous operations will be rewinded (until we reach something older than | |
1271 | * time_seq). | |
1272 | */ | |
1273 | static void | |
f1ca7e98 JB |
1274 | __tree_mod_log_rewind(struct btrfs_fs_info *fs_info, struct extent_buffer *eb, |
1275 | u64 time_seq, struct tree_mod_elem *first_tm) | |
5d9e75c4 JS |
1276 | { |
1277 | u32 n; | |
1278 | struct rb_node *next; | |
1279 | struct tree_mod_elem *tm = first_tm; | |
1280 | unsigned long o_dst; | |
1281 | unsigned long o_src; | |
1282 | unsigned long p_size = sizeof(struct btrfs_key_ptr); | |
1283 | ||
1284 | n = btrfs_header_nritems(eb); | |
f1ca7e98 | 1285 | tree_mod_log_read_lock(fs_info); |
097b8a7c | 1286 | while (tm && tm->seq >= time_seq) { |
5d9e75c4 JS |
1287 | /* |
1288 | * all the operations are recorded with the operator used for | |
1289 | * the modification. as we're going backwards, we do the | |
1290 | * opposite of each operation here. | |
1291 | */ | |
1292 | switch (tm->op) { | |
1293 | case MOD_LOG_KEY_REMOVE_WHILE_FREEING: | |
1294 | BUG_ON(tm->slot < n); | |
1c697d4a | 1295 | /* Fallthrough */ |
95c80bb1 | 1296 | case MOD_LOG_KEY_REMOVE_WHILE_MOVING: |
4c3e6969 | 1297 | case MOD_LOG_KEY_REMOVE: |
5d9e75c4 JS |
1298 | btrfs_set_node_key(eb, &tm->key, tm->slot); |
1299 | btrfs_set_node_blockptr(eb, tm->slot, tm->blockptr); | |
1300 | btrfs_set_node_ptr_generation(eb, tm->slot, | |
1301 | tm->generation); | |
4c3e6969 | 1302 | n++; |
5d9e75c4 JS |
1303 | break; |
1304 | case MOD_LOG_KEY_REPLACE: | |
1305 | BUG_ON(tm->slot >= n); | |
1306 | btrfs_set_node_key(eb, &tm->key, tm->slot); | |
1307 | btrfs_set_node_blockptr(eb, tm->slot, tm->blockptr); | |
1308 | btrfs_set_node_ptr_generation(eb, tm->slot, | |
1309 | tm->generation); | |
1310 | break; | |
1311 | case MOD_LOG_KEY_ADD: | |
19956c7e | 1312 | /* if a move operation is needed it's in the log */ |
5d9e75c4 JS |
1313 | n--; |
1314 | break; | |
1315 | case MOD_LOG_MOVE_KEYS: | |
c3193108 JS |
1316 | o_dst = btrfs_node_key_ptr_offset(tm->slot); |
1317 | o_src = btrfs_node_key_ptr_offset(tm->move.dst_slot); | |
1318 | memmove_extent_buffer(eb, o_dst, o_src, | |
5d9e75c4 JS |
1319 | tm->move.nr_items * p_size); |
1320 | break; | |
1321 | case MOD_LOG_ROOT_REPLACE: | |
1322 | /* | |
1323 | * this operation is special. for roots, this must be | |
1324 | * handled explicitly before rewinding. | |
1325 | * for non-roots, this operation may exist if the node | |
1326 | * was a root: root A -> child B; then A gets empty and | |
1327 | * B is promoted to the new root. in the mod log, we'll | |
1328 | * have a root-replace operation for B, a tree block | |
1329 | * that is no root. we simply ignore that operation. | |
1330 | */ | |
1331 | break; | |
1332 | } | |
1333 | next = rb_next(&tm->node); | |
1334 | if (!next) | |
1335 | break; | |
1336 | tm = container_of(next, struct tree_mod_elem, node); | |
1337 | if (tm->index != first_tm->index) | |
1338 | break; | |
1339 | } | |
f1ca7e98 | 1340 | tree_mod_log_read_unlock(fs_info); |
5d9e75c4 JS |
1341 | btrfs_set_header_nritems(eb, n); |
1342 | } | |
1343 | ||
47fb091f JS |
1344 | /* |
1345 | * Called with eb read locked. If the buffer cannot be rewinded, the same buffer | |
1346 | * is returned. If rewind operations happen, a fresh buffer is returned. The | |
1347 | * returned buffer is always read-locked. If the returned buffer is not the | |
1348 | * input buffer, the lock on the input buffer is released and the input buffer | |
1349 | * is freed (its refcount is decremented). | |
1350 | */ | |
5d9e75c4 | 1351 | static struct extent_buffer * |
9ec72677 JB |
1352 | tree_mod_log_rewind(struct btrfs_fs_info *fs_info, struct btrfs_path *path, |
1353 | struct extent_buffer *eb, u64 time_seq) | |
5d9e75c4 JS |
1354 | { |
1355 | struct extent_buffer *eb_rewin; | |
1356 | struct tree_mod_elem *tm; | |
1357 | ||
1358 | if (!time_seq) | |
1359 | return eb; | |
1360 | ||
1361 | if (btrfs_header_level(eb) == 0) | |
1362 | return eb; | |
1363 | ||
1364 | tm = tree_mod_log_search(fs_info, eb->start, time_seq); | |
1365 | if (!tm) | |
1366 | return eb; | |
1367 | ||
9ec72677 JB |
1368 | btrfs_set_path_blocking(path); |
1369 | btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK); | |
1370 | ||
5d9e75c4 JS |
1371 | if (tm->op == MOD_LOG_KEY_REMOVE_WHILE_FREEING) { |
1372 | BUG_ON(tm->slot != 0); | |
3f556f78 | 1373 | eb_rewin = alloc_dummy_extent_buffer(fs_info, eb->start); |
db7f3436 | 1374 | if (!eb_rewin) { |
9ec72677 | 1375 | btrfs_tree_read_unlock_blocking(eb); |
db7f3436 JB |
1376 | free_extent_buffer(eb); |
1377 | return NULL; | |
1378 | } | |
5d9e75c4 JS |
1379 | btrfs_set_header_bytenr(eb_rewin, eb->start); |
1380 | btrfs_set_header_backref_rev(eb_rewin, | |
1381 | btrfs_header_backref_rev(eb)); | |
1382 | btrfs_set_header_owner(eb_rewin, btrfs_header_owner(eb)); | |
c3193108 | 1383 | btrfs_set_header_level(eb_rewin, btrfs_header_level(eb)); |
5d9e75c4 JS |
1384 | } else { |
1385 | eb_rewin = btrfs_clone_extent_buffer(eb); | |
db7f3436 | 1386 | if (!eb_rewin) { |
9ec72677 | 1387 | btrfs_tree_read_unlock_blocking(eb); |
db7f3436 JB |
1388 | free_extent_buffer(eb); |
1389 | return NULL; | |
1390 | } | |
5d9e75c4 JS |
1391 | } |
1392 | ||
9ec72677 JB |
1393 | btrfs_clear_path_blocking(path, NULL, BTRFS_READ_LOCK); |
1394 | btrfs_tree_read_unlock_blocking(eb); | |
5d9e75c4 JS |
1395 | free_extent_buffer(eb); |
1396 | ||
47fb091f JS |
1397 | extent_buffer_get(eb_rewin); |
1398 | btrfs_tree_read_lock(eb_rewin); | |
f1ca7e98 | 1399 | __tree_mod_log_rewind(fs_info, eb_rewin, time_seq, tm); |
57911b8b | 1400 | WARN_ON(btrfs_header_nritems(eb_rewin) > |
2a745b14 | 1401 | BTRFS_NODEPTRS_PER_BLOCK(fs_info->tree_root)); |
5d9e75c4 JS |
1402 | |
1403 | return eb_rewin; | |
1404 | } | |
1405 | ||
8ba97a15 JS |
1406 | /* |
1407 | * get_old_root() rewinds the state of @root's root node to the given @time_seq | |
1408 | * value. If there are no changes, the current root->root_node is returned. If | |
1409 | * anything changed in between, there's a fresh buffer allocated on which the | |
1410 | * rewind operations are done. In any case, the returned buffer is read locked. | |
1411 | * Returns NULL on error (with no locks held). | |
1412 | */ | |
5d9e75c4 JS |
1413 | static inline struct extent_buffer * |
1414 | get_old_root(struct btrfs_root *root, u64 time_seq) | |
1415 | { | |
1416 | struct tree_mod_elem *tm; | |
30b0463a JS |
1417 | struct extent_buffer *eb = NULL; |
1418 | struct extent_buffer *eb_root; | |
7bfdcf7f | 1419 | struct extent_buffer *old; |
a95236d9 | 1420 | struct tree_mod_root *old_root = NULL; |
4325edd0 | 1421 | u64 old_generation = 0; |
a95236d9 | 1422 | u64 logical; |
5d9e75c4 | 1423 | |
30b0463a JS |
1424 | eb_root = btrfs_read_lock_root_node(root); |
1425 | tm = __tree_mod_log_oldest_root(root->fs_info, eb_root, time_seq); | |
5d9e75c4 | 1426 | if (!tm) |
30b0463a | 1427 | return eb_root; |
5d9e75c4 | 1428 | |
a95236d9 JS |
1429 | if (tm->op == MOD_LOG_ROOT_REPLACE) { |
1430 | old_root = &tm->old_root; | |
1431 | old_generation = tm->generation; | |
1432 | logical = old_root->logical; | |
1433 | } else { | |
30b0463a | 1434 | logical = eb_root->start; |
a95236d9 | 1435 | } |
5d9e75c4 | 1436 | |
a95236d9 | 1437 | tm = tree_mod_log_search(root->fs_info, logical, time_seq); |
834328a8 | 1438 | if (old_root && tm && tm->op != MOD_LOG_KEY_REMOVE_WHILE_FREEING) { |
30b0463a JS |
1439 | btrfs_tree_read_unlock(eb_root); |
1440 | free_extent_buffer(eb_root); | |
ce86cd59 | 1441 | old = read_tree_block(root, logical, 0); |
64c043de LB |
1442 | if (WARN_ON(IS_ERR(old) || !extent_buffer_uptodate(old))) { |
1443 | if (!IS_ERR(old)) | |
1444 | free_extent_buffer(old); | |
efe120a0 FH |
1445 | btrfs_warn(root->fs_info, |
1446 | "failed to read tree block %llu from get_old_root", logical); | |
834328a8 | 1447 | } else { |
7bfdcf7f LB |
1448 | eb = btrfs_clone_extent_buffer(old); |
1449 | free_extent_buffer(old); | |
834328a8 JS |
1450 | } |
1451 | } else if (old_root) { | |
30b0463a JS |
1452 | btrfs_tree_read_unlock(eb_root); |
1453 | free_extent_buffer(eb_root); | |
3f556f78 | 1454 | eb = alloc_dummy_extent_buffer(root->fs_info, logical); |
834328a8 | 1455 | } else { |
9ec72677 | 1456 | btrfs_set_lock_blocking_rw(eb_root, BTRFS_READ_LOCK); |
30b0463a | 1457 | eb = btrfs_clone_extent_buffer(eb_root); |
9ec72677 | 1458 | btrfs_tree_read_unlock_blocking(eb_root); |
30b0463a | 1459 | free_extent_buffer(eb_root); |
834328a8 JS |
1460 | } |
1461 | ||
8ba97a15 JS |
1462 | if (!eb) |
1463 | return NULL; | |
d6381084 | 1464 | extent_buffer_get(eb); |
8ba97a15 | 1465 | btrfs_tree_read_lock(eb); |
a95236d9 | 1466 | if (old_root) { |
5d9e75c4 JS |
1467 | btrfs_set_header_bytenr(eb, eb->start); |
1468 | btrfs_set_header_backref_rev(eb, BTRFS_MIXED_BACKREF_REV); | |
30b0463a | 1469 | btrfs_set_header_owner(eb, btrfs_header_owner(eb_root)); |
a95236d9 JS |
1470 | btrfs_set_header_level(eb, old_root->level); |
1471 | btrfs_set_header_generation(eb, old_generation); | |
5d9e75c4 | 1472 | } |
28da9fb4 | 1473 | if (tm) |
f1ca7e98 | 1474 | __tree_mod_log_rewind(root->fs_info, eb, time_seq, tm); |
28da9fb4 JS |
1475 | else |
1476 | WARN_ON(btrfs_header_level(eb) != 0); | |
57911b8b | 1477 | WARN_ON(btrfs_header_nritems(eb) > BTRFS_NODEPTRS_PER_BLOCK(root)); |
5d9e75c4 JS |
1478 | |
1479 | return eb; | |
1480 | } | |
1481 | ||
5b6602e7 JS |
1482 | int btrfs_old_root_level(struct btrfs_root *root, u64 time_seq) |
1483 | { | |
1484 | struct tree_mod_elem *tm; | |
1485 | int level; | |
30b0463a | 1486 | struct extent_buffer *eb_root = btrfs_root_node(root); |
5b6602e7 | 1487 | |
30b0463a | 1488 | tm = __tree_mod_log_oldest_root(root->fs_info, eb_root, time_seq); |
5b6602e7 JS |
1489 | if (tm && tm->op == MOD_LOG_ROOT_REPLACE) { |
1490 | level = tm->old_root.level; | |
1491 | } else { | |
30b0463a | 1492 | level = btrfs_header_level(eb_root); |
5b6602e7 | 1493 | } |
30b0463a | 1494 | free_extent_buffer(eb_root); |
5b6602e7 JS |
1495 | |
1496 | return level; | |
1497 | } | |
1498 | ||
5d4f98a2 YZ |
1499 | static inline int should_cow_block(struct btrfs_trans_handle *trans, |
1500 | struct btrfs_root *root, | |
1501 | struct extent_buffer *buf) | |
1502 | { | |
fccb84c9 | 1503 | if (btrfs_test_is_dummy_root(root)) |
faa2dbf0 | 1504 | return 0; |
fccb84c9 | 1505 | |
f1ebcc74 LB |
1506 | /* ensure we can see the force_cow */ |
1507 | smp_rmb(); | |
1508 | ||
1509 | /* | |
1510 | * We do not need to cow a block if | |
1511 | * 1) this block is not created or changed in this transaction; | |
1512 | * 2) this block does not belong to TREE_RELOC tree; | |
1513 | * 3) the root is not forced COW. | |
1514 | * | |
1515 | * What is forced COW: | |
1516 | * when we create snapshot during commiting the transaction, | |
1517 | * after we've finished coping src root, we must COW the shared | |
1518 | * block to ensure the metadata consistency. | |
1519 | */ | |
5d4f98a2 YZ |
1520 | if (btrfs_header_generation(buf) == trans->transid && |
1521 | !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN) && | |
1522 | !(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID && | |
f1ebcc74 | 1523 | btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC)) && |
27cdeb70 | 1524 | !test_bit(BTRFS_ROOT_FORCE_COW, &root->state)) |
5d4f98a2 YZ |
1525 | return 0; |
1526 | return 1; | |
1527 | } | |
1528 | ||
d352ac68 CM |
1529 | /* |
1530 | * cows a single block, see __btrfs_cow_block for the real work. | |
1531 | * This version of it has extra checks so that a block isn't cow'd more than | |
1532 | * once per transaction, as long as it hasn't been written yet | |
1533 | */ | |
d397712b | 1534 | noinline int btrfs_cow_block(struct btrfs_trans_handle *trans, |
5f39d397 CM |
1535 | struct btrfs_root *root, struct extent_buffer *buf, |
1536 | struct extent_buffer *parent, int parent_slot, | |
9fa8cfe7 | 1537 | struct extent_buffer **cow_ret) |
6702ed49 CM |
1538 | { |
1539 | u64 search_start; | |
f510cfec | 1540 | int ret; |
dc17ff8f | 1541 | |
31b1a2bd JL |
1542 | if (trans->transaction != root->fs_info->running_transaction) |
1543 | WARN(1, KERN_CRIT "trans %llu running %llu\n", | |
c1c9ff7c | 1544 | trans->transid, |
6702ed49 | 1545 | root->fs_info->running_transaction->transid); |
31b1a2bd JL |
1546 | |
1547 | if (trans->transid != root->fs_info->generation) | |
1548 | WARN(1, KERN_CRIT "trans %llu running %llu\n", | |
c1c9ff7c | 1549 | trans->transid, root->fs_info->generation); |
dc17ff8f | 1550 | |
5d4f98a2 | 1551 | if (!should_cow_block(trans, root, buf)) { |
6702ed49 CM |
1552 | *cow_ret = buf; |
1553 | return 0; | |
1554 | } | |
c487685d | 1555 | |
0b86a832 | 1556 | search_start = buf->start & ~((u64)(1024 * 1024 * 1024) - 1); |
b4ce94de CM |
1557 | |
1558 | if (parent) | |
1559 | btrfs_set_lock_blocking(parent); | |
1560 | btrfs_set_lock_blocking(buf); | |
1561 | ||
f510cfec | 1562 | ret = __btrfs_cow_block(trans, root, buf, parent, |
9fa8cfe7 | 1563 | parent_slot, cow_ret, search_start, 0); |
1abe9b8a | 1564 | |
1565 | trace_btrfs_cow_block(root, buf, *cow_ret); | |
1566 | ||
f510cfec | 1567 | return ret; |
6702ed49 CM |
1568 | } |
1569 | ||
d352ac68 CM |
1570 | /* |
1571 | * helper function for defrag to decide if two blocks pointed to by a | |
1572 | * node are actually close by | |
1573 | */ | |
6b80053d | 1574 | static int close_blocks(u64 blocknr, u64 other, u32 blocksize) |
6702ed49 | 1575 | { |
6b80053d | 1576 | if (blocknr < other && other - (blocknr + blocksize) < 32768) |
6702ed49 | 1577 | return 1; |
6b80053d | 1578 | if (blocknr > other && blocknr - (other + blocksize) < 32768) |
6702ed49 CM |
1579 | return 1; |
1580 | return 0; | |
1581 | } | |
1582 | ||
081e9573 CM |
1583 | /* |
1584 | * compare two keys in a memcmp fashion | |
1585 | */ | |
1586 | static int comp_keys(struct btrfs_disk_key *disk, struct btrfs_key *k2) | |
1587 | { | |
1588 | struct btrfs_key k1; | |
1589 | ||
1590 | btrfs_disk_key_to_cpu(&k1, disk); | |
1591 | ||
20736aba | 1592 | return btrfs_comp_cpu_keys(&k1, k2); |
081e9573 CM |
1593 | } |
1594 | ||
f3465ca4 JB |
1595 | /* |
1596 | * same as comp_keys only with two btrfs_key's | |
1597 | */ | |
5d4f98a2 | 1598 | int btrfs_comp_cpu_keys(struct btrfs_key *k1, struct btrfs_key *k2) |
f3465ca4 JB |
1599 | { |
1600 | if (k1->objectid > k2->objectid) | |
1601 | return 1; | |
1602 | if (k1->objectid < k2->objectid) | |
1603 | return -1; | |
1604 | if (k1->type > k2->type) | |
1605 | return 1; | |
1606 | if (k1->type < k2->type) | |
1607 | return -1; | |
1608 | if (k1->offset > k2->offset) | |
1609 | return 1; | |
1610 | if (k1->offset < k2->offset) | |
1611 | return -1; | |
1612 | return 0; | |
1613 | } | |
081e9573 | 1614 | |
d352ac68 CM |
1615 | /* |
1616 | * this is used by the defrag code to go through all the | |
1617 | * leaves pointed to by a node and reallocate them so that | |
1618 | * disk order is close to key order | |
1619 | */ | |
6702ed49 | 1620 | int btrfs_realloc_node(struct btrfs_trans_handle *trans, |
5f39d397 | 1621 | struct btrfs_root *root, struct extent_buffer *parent, |
de78b51a | 1622 | int start_slot, u64 *last_ret, |
a6b6e75e | 1623 | struct btrfs_key *progress) |
6702ed49 | 1624 | { |
6b80053d | 1625 | struct extent_buffer *cur; |
6702ed49 | 1626 | u64 blocknr; |
ca7a79ad | 1627 | u64 gen; |
e9d0b13b CM |
1628 | u64 search_start = *last_ret; |
1629 | u64 last_block = 0; | |
6702ed49 CM |
1630 | u64 other; |
1631 | u32 parent_nritems; | |
6702ed49 CM |
1632 | int end_slot; |
1633 | int i; | |
1634 | int err = 0; | |
f2183bde | 1635 | int parent_level; |
6b80053d CM |
1636 | int uptodate; |
1637 | u32 blocksize; | |
081e9573 CM |
1638 | int progress_passed = 0; |
1639 | struct btrfs_disk_key disk_key; | |
6702ed49 | 1640 | |
5708b959 | 1641 | parent_level = btrfs_header_level(parent); |
5708b959 | 1642 | |
6c1500f2 JL |
1643 | WARN_ON(trans->transaction != root->fs_info->running_transaction); |
1644 | WARN_ON(trans->transid != root->fs_info->generation); | |
86479a04 | 1645 | |
6b80053d | 1646 | parent_nritems = btrfs_header_nritems(parent); |
707e8a07 | 1647 | blocksize = root->nodesize; |
5dfe2be7 | 1648 | end_slot = parent_nritems - 1; |
6702ed49 | 1649 | |
5dfe2be7 | 1650 | if (parent_nritems <= 1) |
6702ed49 CM |
1651 | return 0; |
1652 | ||
b4ce94de CM |
1653 | btrfs_set_lock_blocking(parent); |
1654 | ||
5dfe2be7 | 1655 | for (i = start_slot; i <= end_slot; i++) { |
6702ed49 | 1656 | int close = 1; |
a6b6e75e | 1657 | |
081e9573 CM |
1658 | btrfs_node_key(parent, &disk_key, i); |
1659 | if (!progress_passed && comp_keys(&disk_key, progress) < 0) | |
1660 | continue; | |
1661 | ||
1662 | progress_passed = 1; | |
6b80053d | 1663 | blocknr = btrfs_node_blockptr(parent, i); |
ca7a79ad | 1664 | gen = btrfs_node_ptr_generation(parent, i); |
e9d0b13b CM |
1665 | if (last_block == 0) |
1666 | last_block = blocknr; | |
5708b959 | 1667 | |
6702ed49 | 1668 | if (i > 0) { |
6b80053d CM |
1669 | other = btrfs_node_blockptr(parent, i - 1); |
1670 | close = close_blocks(blocknr, other, blocksize); | |
6702ed49 | 1671 | } |
5dfe2be7 | 1672 | if (!close && i < end_slot) { |
6b80053d CM |
1673 | other = btrfs_node_blockptr(parent, i + 1); |
1674 | close = close_blocks(blocknr, other, blocksize); | |
6702ed49 | 1675 | } |
e9d0b13b CM |
1676 | if (close) { |
1677 | last_block = blocknr; | |
6702ed49 | 1678 | continue; |
e9d0b13b | 1679 | } |
6702ed49 | 1680 | |
01d58472 | 1681 | cur = btrfs_find_tree_block(root->fs_info, blocknr); |
6b80053d | 1682 | if (cur) |
b9fab919 | 1683 | uptodate = btrfs_buffer_uptodate(cur, gen, 0); |
6b80053d CM |
1684 | else |
1685 | uptodate = 0; | |
5708b959 | 1686 | if (!cur || !uptodate) { |
6b80053d | 1687 | if (!cur) { |
ce86cd59 | 1688 | cur = read_tree_block(root, blocknr, gen); |
64c043de LB |
1689 | if (IS_ERR(cur)) { |
1690 | return PTR_ERR(cur); | |
1691 | } else if (!extent_buffer_uptodate(cur)) { | |
416bc658 | 1692 | free_extent_buffer(cur); |
97d9a8a4 | 1693 | return -EIO; |
416bc658 | 1694 | } |
6b80053d | 1695 | } else if (!uptodate) { |
018642a1 TI |
1696 | err = btrfs_read_buffer(cur, gen); |
1697 | if (err) { | |
1698 | free_extent_buffer(cur); | |
1699 | return err; | |
1700 | } | |
f2183bde | 1701 | } |
6702ed49 | 1702 | } |
e9d0b13b | 1703 | if (search_start == 0) |
6b80053d | 1704 | search_start = last_block; |
e9d0b13b | 1705 | |
e7a84565 | 1706 | btrfs_tree_lock(cur); |
b4ce94de | 1707 | btrfs_set_lock_blocking(cur); |
6b80053d | 1708 | err = __btrfs_cow_block(trans, root, cur, parent, i, |
e7a84565 | 1709 | &cur, search_start, |
6b80053d | 1710 | min(16 * blocksize, |
9fa8cfe7 | 1711 | (end_slot - i) * blocksize)); |
252c38f0 | 1712 | if (err) { |
e7a84565 | 1713 | btrfs_tree_unlock(cur); |
6b80053d | 1714 | free_extent_buffer(cur); |
6702ed49 | 1715 | break; |
252c38f0 | 1716 | } |
e7a84565 CM |
1717 | search_start = cur->start; |
1718 | last_block = cur->start; | |
f2183bde | 1719 | *last_ret = search_start; |
e7a84565 CM |
1720 | btrfs_tree_unlock(cur); |
1721 | free_extent_buffer(cur); | |
6702ed49 CM |
1722 | } |
1723 | return err; | |
1724 | } | |
1725 | ||
74123bd7 CM |
1726 | /* |
1727 | * The leaf data grows from end-to-front in the node. | |
1728 | * this returns the address of the start of the last item, | |
1729 | * which is the stop of the leaf data stack | |
1730 | */ | |
123abc88 | 1731 | static inline unsigned int leaf_data_end(struct btrfs_root *root, |
5f39d397 | 1732 | struct extent_buffer *leaf) |
be0e5c09 | 1733 | { |
5f39d397 | 1734 | u32 nr = btrfs_header_nritems(leaf); |
be0e5c09 | 1735 | if (nr == 0) |
123abc88 | 1736 | return BTRFS_LEAF_DATA_SIZE(root); |
5f39d397 | 1737 | return btrfs_item_offset_nr(leaf, nr - 1); |
be0e5c09 CM |
1738 | } |
1739 | ||
aa5d6bed | 1740 | |
74123bd7 | 1741 | /* |
5f39d397 CM |
1742 | * search for key in the extent_buffer. The items start at offset p, |
1743 | * and they are item_size apart. There are 'max' items in p. | |
1744 | * | |
74123bd7 CM |
1745 | * the slot in the array is returned via slot, and it points to |
1746 | * the place where you would insert key if it is not found in | |
1747 | * the array. | |
1748 | * | |
1749 | * slot may point to max if the key is bigger than all of the keys | |
1750 | */ | |
e02119d5 CM |
1751 | static noinline int generic_bin_search(struct extent_buffer *eb, |
1752 | unsigned long p, | |
1753 | int item_size, struct btrfs_key *key, | |
1754 | int max, int *slot) | |
be0e5c09 CM |
1755 | { |
1756 | int low = 0; | |
1757 | int high = max; | |
1758 | int mid; | |
1759 | int ret; | |
479965d6 | 1760 | struct btrfs_disk_key *tmp = NULL; |
5f39d397 CM |
1761 | struct btrfs_disk_key unaligned; |
1762 | unsigned long offset; | |
5f39d397 CM |
1763 | char *kaddr = NULL; |
1764 | unsigned long map_start = 0; | |
1765 | unsigned long map_len = 0; | |
479965d6 | 1766 | int err; |
be0e5c09 | 1767 | |
d397712b | 1768 | while (low < high) { |
be0e5c09 | 1769 | mid = (low + high) / 2; |
5f39d397 CM |
1770 | offset = p + mid * item_size; |
1771 | ||
a6591715 | 1772 | if (!kaddr || offset < map_start || |
5f39d397 CM |
1773 | (offset + sizeof(struct btrfs_disk_key)) > |
1774 | map_start + map_len) { | |
934d375b CM |
1775 | |
1776 | err = map_private_extent_buffer(eb, offset, | |
479965d6 | 1777 | sizeof(struct btrfs_disk_key), |
a6591715 | 1778 | &kaddr, &map_start, &map_len); |
479965d6 CM |
1779 | |
1780 | if (!err) { | |
1781 | tmp = (struct btrfs_disk_key *)(kaddr + offset - | |
1782 | map_start); | |
1783 | } else { | |
1784 | read_extent_buffer(eb, &unaligned, | |
1785 | offset, sizeof(unaligned)); | |
1786 | tmp = &unaligned; | |
1787 | } | |
5f39d397 | 1788 | |
5f39d397 CM |
1789 | } else { |
1790 | tmp = (struct btrfs_disk_key *)(kaddr + offset - | |
1791 | map_start); | |
1792 | } | |
be0e5c09 CM |
1793 | ret = comp_keys(tmp, key); |
1794 | ||
1795 | if (ret < 0) | |
1796 | low = mid + 1; | |
1797 | else if (ret > 0) | |
1798 | high = mid; | |
1799 | else { | |
1800 | *slot = mid; | |
1801 | return 0; | |
1802 | } | |
1803 | } | |
1804 | *slot = low; | |
1805 | return 1; | |
1806 | } | |
1807 | ||
97571fd0 CM |
1808 | /* |
1809 | * simple bin_search frontend that does the right thing for | |
1810 | * leaves vs nodes | |
1811 | */ | |
5f39d397 CM |
1812 | static int bin_search(struct extent_buffer *eb, struct btrfs_key *key, |
1813 | int level, int *slot) | |
be0e5c09 | 1814 | { |
f775738f | 1815 | if (level == 0) |
5f39d397 CM |
1816 | return generic_bin_search(eb, |
1817 | offsetof(struct btrfs_leaf, items), | |
0783fcfc | 1818 | sizeof(struct btrfs_item), |
5f39d397 | 1819 | key, btrfs_header_nritems(eb), |
7518a238 | 1820 | slot); |
f775738f | 1821 | else |
5f39d397 CM |
1822 | return generic_bin_search(eb, |
1823 | offsetof(struct btrfs_node, ptrs), | |
123abc88 | 1824 | sizeof(struct btrfs_key_ptr), |
5f39d397 | 1825 | key, btrfs_header_nritems(eb), |
7518a238 | 1826 | slot); |
be0e5c09 CM |
1827 | } |
1828 | ||
5d4f98a2 YZ |
1829 | int btrfs_bin_search(struct extent_buffer *eb, struct btrfs_key *key, |
1830 | int level, int *slot) | |
1831 | { | |
1832 | return bin_search(eb, key, level, slot); | |
1833 | } | |
1834 | ||
f0486c68 YZ |
1835 | static void root_add_used(struct btrfs_root *root, u32 size) |
1836 | { | |
1837 | spin_lock(&root->accounting_lock); | |
1838 | btrfs_set_root_used(&root->root_item, | |
1839 | btrfs_root_used(&root->root_item) + size); | |
1840 | spin_unlock(&root->accounting_lock); | |
1841 | } | |
1842 | ||
1843 | static void root_sub_used(struct btrfs_root *root, u32 size) | |
1844 | { | |
1845 | spin_lock(&root->accounting_lock); | |
1846 | btrfs_set_root_used(&root->root_item, | |
1847 | btrfs_root_used(&root->root_item) - size); | |
1848 | spin_unlock(&root->accounting_lock); | |
1849 | } | |
1850 | ||
d352ac68 CM |
1851 | /* given a node and slot number, this reads the blocks it points to. The |
1852 | * extent buffer is returned with a reference taken (but unlocked). | |
1853 | * NULL is returned on error. | |
1854 | */ | |
e02119d5 | 1855 | static noinline struct extent_buffer *read_node_slot(struct btrfs_root *root, |
5f39d397 | 1856 | struct extent_buffer *parent, int slot) |
bb803951 | 1857 | { |
ca7a79ad | 1858 | int level = btrfs_header_level(parent); |
416bc658 JB |
1859 | struct extent_buffer *eb; |
1860 | ||
bb803951 CM |
1861 | if (slot < 0) |
1862 | return NULL; | |
5f39d397 | 1863 | if (slot >= btrfs_header_nritems(parent)) |
bb803951 | 1864 | return NULL; |
ca7a79ad CM |
1865 | |
1866 | BUG_ON(level == 0); | |
1867 | ||
416bc658 | 1868 | eb = read_tree_block(root, btrfs_node_blockptr(parent, slot), |
416bc658 | 1869 | btrfs_node_ptr_generation(parent, slot)); |
64c043de LB |
1870 | if (IS_ERR(eb) || !extent_buffer_uptodate(eb)) { |
1871 | if (!IS_ERR(eb)) | |
1872 | free_extent_buffer(eb); | |
416bc658 JB |
1873 | eb = NULL; |
1874 | } | |
1875 | ||
1876 | return eb; | |
bb803951 CM |
1877 | } |
1878 | ||
d352ac68 CM |
1879 | /* |
1880 | * node level balancing, used to make sure nodes are in proper order for | |
1881 | * item deletion. We balance from the top down, so we have to make sure | |
1882 | * that a deletion won't leave an node completely empty later on. | |
1883 | */ | |
e02119d5 | 1884 | static noinline int balance_level(struct btrfs_trans_handle *trans, |
98ed5174 CM |
1885 | struct btrfs_root *root, |
1886 | struct btrfs_path *path, int level) | |
bb803951 | 1887 | { |
5f39d397 CM |
1888 | struct extent_buffer *right = NULL; |
1889 | struct extent_buffer *mid; | |
1890 | struct extent_buffer *left = NULL; | |
1891 | struct extent_buffer *parent = NULL; | |
bb803951 CM |
1892 | int ret = 0; |
1893 | int wret; | |
1894 | int pslot; | |
bb803951 | 1895 | int orig_slot = path->slots[level]; |
79f95c82 | 1896 | u64 orig_ptr; |
bb803951 CM |
1897 | |
1898 | if (level == 0) | |
1899 | return 0; | |
1900 | ||
5f39d397 | 1901 | mid = path->nodes[level]; |
b4ce94de | 1902 | |
bd681513 CM |
1903 | WARN_ON(path->locks[level] != BTRFS_WRITE_LOCK && |
1904 | path->locks[level] != BTRFS_WRITE_LOCK_BLOCKING); | |
7bb86316 CM |
1905 | WARN_ON(btrfs_header_generation(mid) != trans->transid); |
1906 | ||
1d4f8a0c | 1907 | orig_ptr = btrfs_node_blockptr(mid, orig_slot); |
79f95c82 | 1908 | |
a05a9bb1 | 1909 | if (level < BTRFS_MAX_LEVEL - 1) { |
5f39d397 | 1910 | parent = path->nodes[level + 1]; |
a05a9bb1 LZ |
1911 | pslot = path->slots[level + 1]; |
1912 | } | |
bb803951 | 1913 | |
40689478 CM |
1914 | /* |
1915 | * deal with the case where there is only one pointer in the root | |
1916 | * by promoting the node below to a root | |
1917 | */ | |
5f39d397 CM |
1918 | if (!parent) { |
1919 | struct extent_buffer *child; | |
bb803951 | 1920 | |
5f39d397 | 1921 | if (btrfs_header_nritems(mid) != 1) |
bb803951 CM |
1922 | return 0; |
1923 | ||
1924 | /* promote the child to a root */ | |
5f39d397 | 1925 | child = read_node_slot(root, mid, 0); |
305a26af MF |
1926 | if (!child) { |
1927 | ret = -EROFS; | |
1928 | btrfs_std_error(root->fs_info, ret); | |
1929 | goto enospc; | |
1930 | } | |
1931 | ||
925baedd | 1932 | btrfs_tree_lock(child); |
b4ce94de | 1933 | btrfs_set_lock_blocking(child); |
9fa8cfe7 | 1934 | ret = btrfs_cow_block(trans, root, child, mid, 0, &child); |
f0486c68 YZ |
1935 | if (ret) { |
1936 | btrfs_tree_unlock(child); | |
1937 | free_extent_buffer(child); | |
1938 | goto enospc; | |
1939 | } | |
2f375ab9 | 1940 | |
90f8d62e | 1941 | tree_mod_log_set_root_pointer(root, child, 1); |
240f62c8 | 1942 | rcu_assign_pointer(root->node, child); |
925baedd | 1943 | |
0b86a832 | 1944 | add_root_to_dirty_list(root); |
925baedd | 1945 | btrfs_tree_unlock(child); |
b4ce94de | 1946 | |
925baedd | 1947 | path->locks[level] = 0; |
bb803951 | 1948 | path->nodes[level] = NULL; |
01d58472 | 1949 | clean_tree_block(trans, root->fs_info, mid); |
925baedd | 1950 | btrfs_tree_unlock(mid); |
bb803951 | 1951 | /* once for the path */ |
5f39d397 | 1952 | free_extent_buffer(mid); |
f0486c68 YZ |
1953 | |
1954 | root_sub_used(root, mid->len); | |
5581a51a | 1955 | btrfs_free_tree_block(trans, root, mid, 0, 1); |
bb803951 | 1956 | /* once for the root ptr */ |
3083ee2e | 1957 | free_extent_buffer_stale(mid); |
f0486c68 | 1958 | return 0; |
bb803951 | 1959 | } |
5f39d397 | 1960 | if (btrfs_header_nritems(mid) > |
123abc88 | 1961 | BTRFS_NODEPTRS_PER_BLOCK(root) / 4) |
bb803951 CM |
1962 | return 0; |
1963 | ||
5f39d397 CM |
1964 | left = read_node_slot(root, parent, pslot - 1); |
1965 | if (left) { | |
925baedd | 1966 | btrfs_tree_lock(left); |
b4ce94de | 1967 | btrfs_set_lock_blocking(left); |
5f39d397 | 1968 | wret = btrfs_cow_block(trans, root, left, |
9fa8cfe7 | 1969 | parent, pslot - 1, &left); |
54aa1f4d CM |
1970 | if (wret) { |
1971 | ret = wret; | |
1972 | goto enospc; | |
1973 | } | |
2cc58cf2 | 1974 | } |
5f39d397 CM |
1975 | right = read_node_slot(root, parent, pslot + 1); |
1976 | if (right) { | |
925baedd | 1977 | btrfs_tree_lock(right); |
b4ce94de | 1978 | btrfs_set_lock_blocking(right); |
5f39d397 | 1979 | wret = btrfs_cow_block(trans, root, right, |
9fa8cfe7 | 1980 | parent, pslot + 1, &right); |
2cc58cf2 CM |
1981 | if (wret) { |
1982 | ret = wret; | |
1983 | goto enospc; | |
1984 | } | |
1985 | } | |
1986 | ||
1987 | /* first, try to make some room in the middle buffer */ | |
5f39d397 CM |
1988 | if (left) { |
1989 | orig_slot += btrfs_header_nritems(left); | |
bce4eae9 | 1990 | wret = push_node_left(trans, root, left, mid, 1); |
79f95c82 CM |
1991 | if (wret < 0) |
1992 | ret = wret; | |
bb803951 | 1993 | } |
79f95c82 CM |
1994 | |
1995 | /* | |
1996 | * then try to empty the right most buffer into the middle | |
1997 | */ | |
5f39d397 | 1998 | if (right) { |
971a1f66 | 1999 | wret = push_node_left(trans, root, mid, right, 1); |
54aa1f4d | 2000 | if (wret < 0 && wret != -ENOSPC) |
79f95c82 | 2001 | ret = wret; |
5f39d397 | 2002 | if (btrfs_header_nritems(right) == 0) { |
01d58472 | 2003 | clean_tree_block(trans, root->fs_info, right); |
925baedd | 2004 | btrfs_tree_unlock(right); |
afe5fea7 | 2005 | del_ptr(root, path, level + 1, pslot + 1); |
f0486c68 | 2006 | root_sub_used(root, right->len); |
5581a51a | 2007 | btrfs_free_tree_block(trans, root, right, 0, 1); |
3083ee2e | 2008 | free_extent_buffer_stale(right); |
f0486c68 | 2009 | right = NULL; |
bb803951 | 2010 | } else { |
5f39d397 CM |
2011 | struct btrfs_disk_key right_key; |
2012 | btrfs_node_key(right, &right_key, 0); | |
f230475e | 2013 | tree_mod_log_set_node_key(root->fs_info, parent, |
32adf090 | 2014 | pslot + 1, 0); |
5f39d397 CM |
2015 | btrfs_set_node_key(parent, &right_key, pslot + 1); |
2016 | btrfs_mark_buffer_dirty(parent); | |
bb803951 CM |
2017 | } |
2018 | } | |
5f39d397 | 2019 | if (btrfs_header_nritems(mid) == 1) { |
79f95c82 CM |
2020 | /* |
2021 | * we're not allowed to leave a node with one item in the | |
2022 | * tree during a delete. A deletion from lower in the tree | |
2023 | * could try to delete the only pointer in this node. | |
2024 | * So, pull some keys from the left. | |
2025 | * There has to be a left pointer at this point because | |
2026 | * otherwise we would have pulled some pointers from the | |
2027 | * right | |
2028 | */ | |
305a26af MF |
2029 | if (!left) { |
2030 | ret = -EROFS; | |
2031 | btrfs_std_error(root->fs_info, ret); | |
2032 | goto enospc; | |
2033 | } | |
5f39d397 | 2034 | wret = balance_node_right(trans, root, mid, left); |
54aa1f4d | 2035 | if (wret < 0) { |
79f95c82 | 2036 | ret = wret; |
54aa1f4d CM |
2037 | goto enospc; |
2038 | } | |
bce4eae9 CM |
2039 | if (wret == 1) { |
2040 | wret = push_node_left(trans, root, left, mid, 1); | |
2041 | if (wret < 0) | |
2042 | ret = wret; | |
2043 | } | |
79f95c82 CM |
2044 | BUG_ON(wret == 1); |
2045 | } | |
5f39d397 | 2046 | if (btrfs_header_nritems(mid) == 0) { |
01d58472 | 2047 | clean_tree_block(trans, root->fs_info, mid); |
925baedd | 2048 | btrfs_tree_unlock(mid); |
afe5fea7 | 2049 | del_ptr(root, path, level + 1, pslot); |
f0486c68 | 2050 | root_sub_used(root, mid->len); |
5581a51a | 2051 | btrfs_free_tree_block(trans, root, mid, 0, 1); |
3083ee2e | 2052 | free_extent_buffer_stale(mid); |
f0486c68 | 2053 | mid = NULL; |
79f95c82 CM |
2054 | } else { |
2055 | /* update the parent key to reflect our changes */ | |
5f39d397 CM |
2056 | struct btrfs_disk_key mid_key; |
2057 | btrfs_node_key(mid, &mid_key, 0); | |
32adf090 | 2058 | tree_mod_log_set_node_key(root->fs_info, parent, |
f230475e | 2059 | pslot, 0); |
5f39d397 CM |
2060 | btrfs_set_node_key(parent, &mid_key, pslot); |
2061 | btrfs_mark_buffer_dirty(parent); | |
79f95c82 | 2062 | } |
bb803951 | 2063 | |
79f95c82 | 2064 | /* update the path */ |
5f39d397 CM |
2065 | if (left) { |
2066 | if (btrfs_header_nritems(left) > orig_slot) { | |
2067 | extent_buffer_get(left); | |
925baedd | 2068 | /* left was locked after cow */ |
5f39d397 | 2069 | path->nodes[level] = left; |
bb803951 CM |
2070 | path->slots[level + 1] -= 1; |
2071 | path->slots[level] = orig_slot; | |
925baedd CM |
2072 | if (mid) { |
2073 | btrfs_tree_unlock(mid); | |
5f39d397 | 2074 | free_extent_buffer(mid); |
925baedd | 2075 | } |
bb803951 | 2076 | } else { |
5f39d397 | 2077 | orig_slot -= btrfs_header_nritems(left); |
bb803951 CM |
2078 | path->slots[level] = orig_slot; |
2079 | } | |
2080 | } | |
79f95c82 | 2081 | /* double check we haven't messed things up */ |
e20d96d6 | 2082 | if (orig_ptr != |
5f39d397 | 2083 | btrfs_node_blockptr(path->nodes[level], path->slots[level])) |
79f95c82 | 2084 | BUG(); |
54aa1f4d | 2085 | enospc: |
925baedd CM |
2086 | if (right) { |
2087 | btrfs_tree_unlock(right); | |
5f39d397 | 2088 | free_extent_buffer(right); |
925baedd CM |
2089 | } |
2090 | if (left) { | |
2091 | if (path->nodes[level] != left) | |
2092 | btrfs_tree_unlock(left); | |
5f39d397 | 2093 | free_extent_buffer(left); |
925baedd | 2094 | } |
bb803951 CM |
2095 | return ret; |
2096 | } | |
2097 | ||
d352ac68 CM |
2098 | /* Node balancing for insertion. Here we only split or push nodes around |
2099 | * when they are completely full. This is also done top down, so we | |
2100 | * have to be pessimistic. | |
2101 | */ | |
d397712b | 2102 | static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans, |
98ed5174 CM |
2103 | struct btrfs_root *root, |
2104 | struct btrfs_path *path, int level) | |
e66f709b | 2105 | { |
5f39d397 CM |
2106 | struct extent_buffer *right = NULL; |
2107 | struct extent_buffer *mid; | |
2108 | struct extent_buffer *left = NULL; | |
2109 | struct extent_buffer *parent = NULL; | |
e66f709b CM |
2110 | int ret = 0; |
2111 | int wret; | |
2112 | int pslot; | |
2113 | int orig_slot = path->slots[level]; | |
e66f709b CM |
2114 | |
2115 | if (level == 0) | |
2116 | return 1; | |
2117 | ||
5f39d397 | 2118 | mid = path->nodes[level]; |
7bb86316 | 2119 | WARN_ON(btrfs_header_generation(mid) != trans->transid); |
e66f709b | 2120 | |
a05a9bb1 | 2121 | if (level < BTRFS_MAX_LEVEL - 1) { |
5f39d397 | 2122 | parent = path->nodes[level + 1]; |
a05a9bb1 LZ |
2123 | pslot = path->slots[level + 1]; |
2124 | } | |
e66f709b | 2125 | |
5f39d397 | 2126 | if (!parent) |
e66f709b | 2127 | return 1; |
e66f709b | 2128 | |
5f39d397 | 2129 | left = read_node_slot(root, parent, pslot - 1); |
e66f709b CM |
2130 | |
2131 | /* first, try to make some room in the middle buffer */ | |
5f39d397 | 2132 | if (left) { |
e66f709b | 2133 | u32 left_nr; |
925baedd CM |
2134 | |
2135 | btrfs_tree_lock(left); | |
b4ce94de CM |
2136 | btrfs_set_lock_blocking(left); |
2137 | ||
5f39d397 | 2138 | left_nr = btrfs_header_nritems(left); |
33ade1f8 CM |
2139 | if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) { |
2140 | wret = 1; | |
2141 | } else { | |
5f39d397 | 2142 | ret = btrfs_cow_block(trans, root, left, parent, |
9fa8cfe7 | 2143 | pslot - 1, &left); |
54aa1f4d CM |
2144 | if (ret) |
2145 | wret = 1; | |
2146 | else { | |
54aa1f4d | 2147 | wret = push_node_left(trans, root, |
971a1f66 | 2148 | left, mid, 0); |
54aa1f4d | 2149 | } |
33ade1f8 | 2150 | } |
e66f709b CM |
2151 | if (wret < 0) |
2152 | ret = wret; | |
2153 | if (wret == 0) { | |
5f39d397 | 2154 | struct btrfs_disk_key disk_key; |
e66f709b | 2155 | orig_slot += left_nr; |
5f39d397 | 2156 | btrfs_node_key(mid, &disk_key, 0); |
f230475e | 2157 | tree_mod_log_set_node_key(root->fs_info, parent, |
32adf090 | 2158 | pslot, 0); |
5f39d397 CM |
2159 | btrfs_set_node_key(parent, &disk_key, pslot); |
2160 | btrfs_mark_buffer_dirty(parent); | |
2161 | if (btrfs_header_nritems(left) > orig_slot) { | |
2162 | path->nodes[level] = left; | |
e66f709b CM |
2163 | path->slots[level + 1] -= 1; |
2164 | path->slots[level] = orig_slot; | |
925baedd | 2165 | btrfs_tree_unlock(mid); |
5f39d397 | 2166 | free_extent_buffer(mid); |
e66f709b CM |
2167 | } else { |
2168 | orig_slot -= | |
5f39d397 | 2169 | btrfs_header_nritems(left); |
e66f709b | 2170 | path->slots[level] = orig_slot; |
925baedd | 2171 | btrfs_tree_unlock(left); |
5f39d397 | 2172 | free_extent_buffer(left); |
e66f709b | 2173 | } |
e66f709b CM |
2174 | return 0; |
2175 | } | |
925baedd | 2176 | btrfs_tree_unlock(left); |
5f39d397 | 2177 | free_extent_buffer(left); |
e66f709b | 2178 | } |
925baedd | 2179 | right = read_node_slot(root, parent, pslot + 1); |
e66f709b CM |
2180 | |
2181 | /* | |
2182 | * then try to empty the right most buffer into the middle | |
2183 | */ | |
5f39d397 | 2184 | if (right) { |
33ade1f8 | 2185 | u32 right_nr; |
b4ce94de | 2186 | |
925baedd | 2187 | btrfs_tree_lock(right); |
b4ce94de CM |
2188 | btrfs_set_lock_blocking(right); |
2189 | ||
5f39d397 | 2190 | right_nr = btrfs_header_nritems(right); |
33ade1f8 CM |
2191 | if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) { |
2192 | wret = 1; | |
2193 | } else { | |
5f39d397 CM |
2194 | ret = btrfs_cow_block(trans, root, right, |
2195 | parent, pslot + 1, | |
9fa8cfe7 | 2196 | &right); |
54aa1f4d CM |
2197 | if (ret) |
2198 | wret = 1; | |
2199 | else { | |
54aa1f4d | 2200 | wret = balance_node_right(trans, root, |
5f39d397 | 2201 | right, mid); |
54aa1f4d | 2202 | } |
33ade1f8 | 2203 | } |
e66f709b CM |
2204 | if (wret < 0) |
2205 | ret = wret; | |
2206 | if (wret == 0) { | |
5f39d397 CM |
2207 | struct btrfs_disk_key disk_key; |
2208 | ||
2209 | btrfs_node_key(right, &disk_key, 0); | |
f230475e | 2210 | tree_mod_log_set_node_key(root->fs_info, parent, |
32adf090 | 2211 | pslot + 1, 0); |
5f39d397 CM |
2212 | btrfs_set_node_key(parent, &disk_key, pslot + 1); |
2213 | btrfs_mark_buffer_dirty(parent); | |
2214 | ||
2215 | if (btrfs_header_nritems(mid) <= orig_slot) { | |
2216 | path->nodes[level] = right; | |
e66f709b CM |
2217 | path->slots[level + 1] += 1; |
2218 | path->slots[level] = orig_slot - | |
5f39d397 | 2219 | btrfs_header_nritems(mid); |
925baedd | 2220 | btrfs_tree_unlock(mid); |
5f39d397 | 2221 | free_extent_buffer(mid); |
e66f709b | 2222 | } else { |
925baedd | 2223 | btrfs_tree_unlock(right); |
5f39d397 | 2224 | free_extent_buffer(right); |
e66f709b | 2225 | } |
e66f709b CM |
2226 | return 0; |
2227 | } | |
925baedd | 2228 | btrfs_tree_unlock(right); |
5f39d397 | 2229 | free_extent_buffer(right); |
e66f709b | 2230 | } |
e66f709b CM |
2231 | return 1; |
2232 | } | |
2233 | ||
3c69faec | 2234 | /* |
d352ac68 CM |
2235 | * readahead one full node of leaves, finding things that are close |
2236 | * to the block in 'slot', and triggering ra on them. | |
3c69faec | 2237 | */ |
c8c42864 CM |
2238 | static void reada_for_search(struct btrfs_root *root, |
2239 | struct btrfs_path *path, | |
2240 | int level, int slot, u64 objectid) | |
3c69faec | 2241 | { |
5f39d397 | 2242 | struct extent_buffer *node; |
01f46658 | 2243 | struct btrfs_disk_key disk_key; |
3c69faec | 2244 | u32 nritems; |
3c69faec | 2245 | u64 search; |
a7175319 | 2246 | u64 target; |
6b80053d | 2247 | u64 nread = 0; |
cb25c2ea | 2248 | u64 gen; |
3c69faec | 2249 | int direction = path->reada; |
5f39d397 | 2250 | struct extent_buffer *eb; |
6b80053d CM |
2251 | u32 nr; |
2252 | u32 blocksize; | |
2253 | u32 nscan = 0; | |
db94535d | 2254 | |
a6b6e75e | 2255 | if (level != 1) |
6702ed49 CM |
2256 | return; |
2257 | ||
2258 | if (!path->nodes[level]) | |
3c69faec CM |
2259 | return; |
2260 | ||
5f39d397 | 2261 | node = path->nodes[level]; |
925baedd | 2262 | |
3c69faec | 2263 | search = btrfs_node_blockptr(node, slot); |
707e8a07 | 2264 | blocksize = root->nodesize; |
01d58472 | 2265 | eb = btrfs_find_tree_block(root->fs_info, search); |
5f39d397 CM |
2266 | if (eb) { |
2267 | free_extent_buffer(eb); | |
3c69faec CM |
2268 | return; |
2269 | } | |
2270 | ||
a7175319 | 2271 | target = search; |
6b80053d | 2272 | |
5f39d397 | 2273 | nritems = btrfs_header_nritems(node); |
6b80053d | 2274 | nr = slot; |
25b8b936 | 2275 | |
d397712b | 2276 | while (1) { |
6b80053d CM |
2277 | if (direction < 0) { |
2278 | if (nr == 0) | |
2279 | break; | |
2280 | nr--; | |
2281 | } else if (direction > 0) { | |
2282 | nr++; | |
2283 | if (nr >= nritems) | |
2284 | break; | |
3c69faec | 2285 | } |
01f46658 CM |
2286 | if (path->reada < 0 && objectid) { |
2287 | btrfs_node_key(node, &disk_key, nr); | |
2288 | if (btrfs_disk_key_objectid(&disk_key) != objectid) | |
2289 | break; | |
2290 | } | |
6b80053d | 2291 | search = btrfs_node_blockptr(node, nr); |
a7175319 CM |
2292 | if ((search <= target && target - search <= 65536) || |
2293 | (search > target && search - target <= 65536)) { | |
cb25c2ea | 2294 | gen = btrfs_node_ptr_generation(node, nr); |
d3e46fea | 2295 | readahead_tree_block(root, search); |
6b80053d CM |
2296 | nread += blocksize; |
2297 | } | |
2298 | nscan++; | |
a7175319 | 2299 | if ((nread > 65536 || nscan > 32)) |
6b80053d | 2300 | break; |
3c69faec CM |
2301 | } |
2302 | } | |
925baedd | 2303 | |
0b08851f JB |
2304 | static noinline void reada_for_balance(struct btrfs_root *root, |
2305 | struct btrfs_path *path, int level) | |
b4ce94de CM |
2306 | { |
2307 | int slot; | |
2308 | int nritems; | |
2309 | struct extent_buffer *parent; | |
2310 | struct extent_buffer *eb; | |
2311 | u64 gen; | |
2312 | u64 block1 = 0; | |
2313 | u64 block2 = 0; | |
b4ce94de | 2314 | |
8c594ea8 | 2315 | parent = path->nodes[level + 1]; |
b4ce94de | 2316 | if (!parent) |
0b08851f | 2317 | return; |
b4ce94de CM |
2318 | |
2319 | nritems = btrfs_header_nritems(parent); | |
8c594ea8 | 2320 | slot = path->slots[level + 1]; |
b4ce94de CM |
2321 | |
2322 | if (slot > 0) { | |
2323 | block1 = btrfs_node_blockptr(parent, slot - 1); | |
2324 | gen = btrfs_node_ptr_generation(parent, slot - 1); | |
01d58472 | 2325 | eb = btrfs_find_tree_block(root->fs_info, block1); |
b9fab919 CM |
2326 | /* |
2327 | * if we get -eagain from btrfs_buffer_uptodate, we | |
2328 | * don't want to return eagain here. That will loop | |
2329 | * forever | |
2330 | */ | |
2331 | if (eb && btrfs_buffer_uptodate(eb, gen, 1) != 0) | |
b4ce94de CM |
2332 | block1 = 0; |
2333 | free_extent_buffer(eb); | |
2334 | } | |
8c594ea8 | 2335 | if (slot + 1 < nritems) { |
b4ce94de CM |
2336 | block2 = btrfs_node_blockptr(parent, slot + 1); |
2337 | gen = btrfs_node_ptr_generation(parent, slot + 1); | |
01d58472 | 2338 | eb = btrfs_find_tree_block(root->fs_info, block2); |
b9fab919 | 2339 | if (eb && btrfs_buffer_uptodate(eb, gen, 1) != 0) |
b4ce94de CM |
2340 | block2 = 0; |
2341 | free_extent_buffer(eb); | |
2342 | } | |
8c594ea8 | 2343 | |
0b08851f | 2344 | if (block1) |
d3e46fea | 2345 | readahead_tree_block(root, block1); |
0b08851f | 2346 | if (block2) |
d3e46fea | 2347 | readahead_tree_block(root, block2); |
b4ce94de CM |
2348 | } |
2349 | ||
2350 | ||
d352ac68 | 2351 | /* |
d397712b CM |
2352 | * when we walk down the tree, it is usually safe to unlock the higher layers |
2353 | * in the tree. The exceptions are when our path goes through slot 0, because | |
2354 | * operations on the tree might require changing key pointers higher up in the | |
2355 | * tree. | |
d352ac68 | 2356 | * |
d397712b CM |
2357 | * callers might also have set path->keep_locks, which tells this code to keep |
2358 | * the lock if the path points to the last slot in the block. This is part of | |
2359 | * walking through the tree, and selecting the next slot in the higher block. | |
d352ac68 | 2360 | * |
d397712b CM |
2361 | * lowest_unlock sets the lowest level in the tree we're allowed to unlock. so |
2362 | * if lowest_unlock is 1, level 0 won't be unlocked | |
d352ac68 | 2363 | */ |
e02119d5 | 2364 | static noinline void unlock_up(struct btrfs_path *path, int level, |
f7c79f30 CM |
2365 | int lowest_unlock, int min_write_lock_level, |
2366 | int *write_lock_level) | |
925baedd CM |
2367 | { |
2368 | int i; | |
2369 | int skip_level = level; | |
051e1b9f | 2370 | int no_skips = 0; |
925baedd CM |
2371 | struct extent_buffer *t; |
2372 | ||
2373 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { | |
2374 | if (!path->nodes[i]) | |
2375 | break; | |
2376 | if (!path->locks[i]) | |
2377 | break; | |
051e1b9f | 2378 | if (!no_skips && path->slots[i] == 0) { |
925baedd CM |
2379 | skip_level = i + 1; |
2380 | continue; | |
2381 | } | |
051e1b9f | 2382 | if (!no_skips && path->keep_locks) { |
925baedd CM |
2383 | u32 nritems; |
2384 | t = path->nodes[i]; | |
2385 | nritems = btrfs_header_nritems(t); | |
051e1b9f | 2386 | if (nritems < 1 || path->slots[i] >= nritems - 1) { |
925baedd CM |
2387 | skip_level = i + 1; |
2388 | continue; | |
2389 | } | |
2390 | } | |
051e1b9f CM |
2391 | if (skip_level < i && i >= lowest_unlock) |
2392 | no_skips = 1; | |
2393 | ||
925baedd CM |
2394 | t = path->nodes[i]; |
2395 | if (i >= lowest_unlock && i > skip_level && path->locks[i]) { | |
bd681513 | 2396 | btrfs_tree_unlock_rw(t, path->locks[i]); |
925baedd | 2397 | path->locks[i] = 0; |
f7c79f30 CM |
2398 | if (write_lock_level && |
2399 | i > min_write_lock_level && | |
2400 | i <= *write_lock_level) { | |
2401 | *write_lock_level = i - 1; | |
2402 | } | |
925baedd CM |
2403 | } |
2404 | } | |
2405 | } | |
2406 | ||
b4ce94de CM |
2407 | /* |
2408 | * This releases any locks held in the path starting at level and | |
2409 | * going all the way up to the root. | |
2410 | * | |
2411 | * btrfs_search_slot will keep the lock held on higher nodes in a few | |
2412 | * corner cases, such as COW of the block at slot zero in the node. This | |
2413 | * ignores those rules, and it should only be called when there are no | |
2414 | * more updates to be done higher up in the tree. | |
2415 | */ | |
2416 | noinline void btrfs_unlock_up_safe(struct btrfs_path *path, int level) | |
2417 | { | |
2418 | int i; | |
2419 | ||
09a2a8f9 | 2420 | if (path->keep_locks) |
b4ce94de CM |
2421 | return; |
2422 | ||
2423 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { | |
2424 | if (!path->nodes[i]) | |
12f4dacc | 2425 | continue; |
b4ce94de | 2426 | if (!path->locks[i]) |
12f4dacc | 2427 | continue; |
bd681513 | 2428 | btrfs_tree_unlock_rw(path->nodes[i], path->locks[i]); |
b4ce94de CM |
2429 | path->locks[i] = 0; |
2430 | } | |
2431 | } | |
2432 | ||
c8c42864 CM |
2433 | /* |
2434 | * helper function for btrfs_search_slot. The goal is to find a block | |
2435 | * in cache without setting the path to blocking. If we find the block | |
2436 | * we return zero and the path is unchanged. | |
2437 | * | |
2438 | * If we can't find the block, we set the path blocking and do some | |
2439 | * reada. -EAGAIN is returned and the search must be repeated. | |
2440 | */ | |
2441 | static int | |
2442 | read_block_for_search(struct btrfs_trans_handle *trans, | |
2443 | struct btrfs_root *root, struct btrfs_path *p, | |
2444 | struct extent_buffer **eb_ret, int level, int slot, | |
5d9e75c4 | 2445 | struct btrfs_key *key, u64 time_seq) |
c8c42864 CM |
2446 | { |
2447 | u64 blocknr; | |
2448 | u64 gen; | |
c8c42864 CM |
2449 | struct extent_buffer *b = *eb_ret; |
2450 | struct extent_buffer *tmp; | |
76a05b35 | 2451 | int ret; |
c8c42864 CM |
2452 | |
2453 | blocknr = btrfs_node_blockptr(b, slot); | |
2454 | gen = btrfs_node_ptr_generation(b, slot); | |
c8c42864 | 2455 | |
01d58472 | 2456 | tmp = btrfs_find_tree_block(root->fs_info, blocknr); |
cb44921a | 2457 | if (tmp) { |
b9fab919 | 2458 | /* first we do an atomic uptodate check */ |
bdf7c00e JB |
2459 | if (btrfs_buffer_uptodate(tmp, gen, 1) > 0) { |
2460 | *eb_ret = tmp; | |
2461 | return 0; | |
2462 | } | |
2463 | ||
2464 | /* the pages were up to date, but we failed | |
2465 | * the generation number check. Do a full | |
2466 | * read for the generation number that is correct. | |
2467 | * We must do this without dropping locks so | |
2468 | * we can trust our generation number | |
2469 | */ | |
2470 | btrfs_set_path_blocking(p); | |
2471 | ||
2472 | /* now we're allowed to do a blocking uptodate check */ | |
2473 | ret = btrfs_read_buffer(tmp, gen); | |
2474 | if (!ret) { | |
2475 | *eb_ret = tmp; | |
2476 | return 0; | |
cb44921a | 2477 | } |
bdf7c00e JB |
2478 | free_extent_buffer(tmp); |
2479 | btrfs_release_path(p); | |
2480 | return -EIO; | |
c8c42864 CM |
2481 | } |
2482 | ||
2483 | /* | |
2484 | * reduce lock contention at high levels | |
2485 | * of the btree by dropping locks before | |
76a05b35 CM |
2486 | * we read. Don't release the lock on the current |
2487 | * level because we need to walk this node to figure | |
2488 | * out which blocks to read. | |
c8c42864 | 2489 | */ |
8c594ea8 CM |
2490 | btrfs_unlock_up_safe(p, level + 1); |
2491 | btrfs_set_path_blocking(p); | |
2492 | ||
cb44921a | 2493 | free_extent_buffer(tmp); |
c8c42864 CM |
2494 | if (p->reada) |
2495 | reada_for_search(root, p, level, slot, key->objectid); | |
2496 | ||
b3b4aa74 | 2497 | btrfs_release_path(p); |
76a05b35 CM |
2498 | |
2499 | ret = -EAGAIN; | |
ce86cd59 | 2500 | tmp = read_tree_block(root, blocknr, 0); |
64c043de | 2501 | if (!IS_ERR(tmp)) { |
76a05b35 CM |
2502 | /* |
2503 | * If the read above didn't mark this buffer up to date, | |
2504 | * it will never end up being up to date. Set ret to EIO now | |
2505 | * and give up so that our caller doesn't loop forever | |
2506 | * on our EAGAINs. | |
2507 | */ | |
b9fab919 | 2508 | if (!btrfs_buffer_uptodate(tmp, 0, 0)) |
76a05b35 | 2509 | ret = -EIO; |
c8c42864 | 2510 | free_extent_buffer(tmp); |
76a05b35 CM |
2511 | } |
2512 | return ret; | |
c8c42864 CM |
2513 | } |
2514 | ||
2515 | /* | |
2516 | * helper function for btrfs_search_slot. This does all of the checks | |
2517 | * for node-level blocks and does any balancing required based on | |
2518 | * the ins_len. | |
2519 | * | |
2520 | * If no extra work was required, zero is returned. If we had to | |
2521 | * drop the path, -EAGAIN is returned and btrfs_search_slot must | |
2522 | * start over | |
2523 | */ | |
2524 | static int | |
2525 | setup_nodes_for_search(struct btrfs_trans_handle *trans, | |
2526 | struct btrfs_root *root, struct btrfs_path *p, | |
bd681513 CM |
2527 | struct extent_buffer *b, int level, int ins_len, |
2528 | int *write_lock_level) | |
c8c42864 CM |
2529 | { |
2530 | int ret; | |
2531 | if ((p->search_for_split || ins_len > 0) && btrfs_header_nritems(b) >= | |
2532 | BTRFS_NODEPTRS_PER_BLOCK(root) - 3) { | |
2533 | int sret; | |
2534 | ||
bd681513 CM |
2535 | if (*write_lock_level < level + 1) { |
2536 | *write_lock_level = level + 1; | |
2537 | btrfs_release_path(p); | |
2538 | goto again; | |
2539 | } | |
2540 | ||
c8c42864 | 2541 | btrfs_set_path_blocking(p); |
0b08851f | 2542 | reada_for_balance(root, p, level); |
c8c42864 | 2543 | sret = split_node(trans, root, p, level); |
bd681513 | 2544 | btrfs_clear_path_blocking(p, NULL, 0); |
c8c42864 CM |
2545 | |
2546 | BUG_ON(sret > 0); | |
2547 | if (sret) { | |
2548 | ret = sret; | |
2549 | goto done; | |
2550 | } | |
2551 | b = p->nodes[level]; | |
2552 | } else if (ins_len < 0 && btrfs_header_nritems(b) < | |
cfbb9308 | 2553 | BTRFS_NODEPTRS_PER_BLOCK(root) / 2) { |
c8c42864 CM |
2554 | int sret; |
2555 | ||
bd681513 CM |
2556 | if (*write_lock_level < level + 1) { |
2557 | *write_lock_level = level + 1; | |
2558 | btrfs_release_path(p); | |
2559 | goto again; | |
2560 | } | |
2561 | ||
c8c42864 | 2562 | btrfs_set_path_blocking(p); |
0b08851f | 2563 | reada_for_balance(root, p, level); |
c8c42864 | 2564 | sret = balance_level(trans, root, p, level); |
bd681513 | 2565 | btrfs_clear_path_blocking(p, NULL, 0); |
c8c42864 CM |
2566 | |
2567 | if (sret) { | |
2568 | ret = sret; | |
2569 | goto done; | |
2570 | } | |
2571 | b = p->nodes[level]; | |
2572 | if (!b) { | |
b3b4aa74 | 2573 | btrfs_release_path(p); |
c8c42864 CM |
2574 | goto again; |
2575 | } | |
2576 | BUG_ON(btrfs_header_nritems(b) == 1); | |
2577 | } | |
2578 | return 0; | |
2579 | ||
2580 | again: | |
2581 | ret = -EAGAIN; | |
2582 | done: | |
2583 | return ret; | |
2584 | } | |
2585 | ||
d7396f07 FDBM |
2586 | static void key_search_validate(struct extent_buffer *b, |
2587 | struct btrfs_key *key, | |
2588 | int level) | |
2589 | { | |
2590 | #ifdef CONFIG_BTRFS_ASSERT | |
2591 | struct btrfs_disk_key disk_key; | |
2592 | ||
2593 | btrfs_cpu_key_to_disk(&disk_key, key); | |
2594 | ||
2595 | if (level == 0) | |
2596 | ASSERT(!memcmp_extent_buffer(b, &disk_key, | |
2597 | offsetof(struct btrfs_leaf, items[0].key), | |
2598 | sizeof(disk_key))); | |
2599 | else | |
2600 | ASSERT(!memcmp_extent_buffer(b, &disk_key, | |
2601 | offsetof(struct btrfs_node, ptrs[0].key), | |
2602 | sizeof(disk_key))); | |
2603 | #endif | |
2604 | } | |
2605 | ||
2606 | static int key_search(struct extent_buffer *b, struct btrfs_key *key, | |
2607 | int level, int *prev_cmp, int *slot) | |
2608 | { | |
2609 | if (*prev_cmp != 0) { | |
2610 | *prev_cmp = bin_search(b, key, level, slot); | |
2611 | return *prev_cmp; | |
2612 | } | |
2613 | ||
2614 | key_search_validate(b, key, level); | |
2615 | *slot = 0; | |
2616 | ||
2617 | return 0; | |
2618 | } | |
2619 | ||
381cf658 | 2620 | int btrfs_find_item(struct btrfs_root *fs_root, struct btrfs_path *path, |
e33d5c3d KN |
2621 | u64 iobjectid, u64 ioff, u8 key_type, |
2622 | struct btrfs_key *found_key) | |
2623 | { | |
2624 | int ret; | |
2625 | struct btrfs_key key; | |
2626 | struct extent_buffer *eb; | |
381cf658 DS |
2627 | |
2628 | ASSERT(path); | |
1d4c08e0 | 2629 | ASSERT(found_key); |
e33d5c3d KN |
2630 | |
2631 | key.type = key_type; | |
2632 | key.objectid = iobjectid; | |
2633 | key.offset = ioff; | |
2634 | ||
2635 | ret = btrfs_search_slot(NULL, fs_root, &key, path, 0, 0); | |
1d4c08e0 | 2636 | if (ret < 0) |
e33d5c3d KN |
2637 | return ret; |
2638 | ||
2639 | eb = path->nodes[0]; | |
2640 | if (ret && path->slots[0] >= btrfs_header_nritems(eb)) { | |
2641 | ret = btrfs_next_leaf(fs_root, path); | |
2642 | if (ret) | |
2643 | return ret; | |
2644 | eb = path->nodes[0]; | |
2645 | } | |
2646 | ||
2647 | btrfs_item_key_to_cpu(eb, found_key, path->slots[0]); | |
2648 | if (found_key->type != key.type || | |
2649 | found_key->objectid != key.objectid) | |
2650 | return 1; | |
2651 | ||
2652 | return 0; | |
2653 | } | |
2654 | ||
74123bd7 CM |
2655 | /* |
2656 | * look for key in the tree. path is filled in with nodes along the way | |
2657 | * if key is found, we return zero and you can find the item in the leaf | |
2658 | * level of the path (level 0) | |
2659 | * | |
2660 | * If the key isn't found, the path points to the slot where it should | |
aa5d6bed CM |
2661 | * be inserted, and 1 is returned. If there are other errors during the |
2662 | * search a negative error number is returned. | |
97571fd0 CM |
2663 | * |
2664 | * if ins_len > 0, nodes and leaves will be split as we walk down the | |
2665 | * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if | |
2666 | * possible) | |
74123bd7 | 2667 | */ |
e089f05c CM |
2668 | int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root |
2669 | *root, struct btrfs_key *key, struct btrfs_path *p, int | |
2670 | ins_len, int cow) | |
be0e5c09 | 2671 | { |
5f39d397 | 2672 | struct extent_buffer *b; |
be0e5c09 CM |
2673 | int slot; |
2674 | int ret; | |
33c66f43 | 2675 | int err; |
be0e5c09 | 2676 | int level; |
925baedd | 2677 | int lowest_unlock = 1; |
bd681513 CM |
2678 | int root_lock; |
2679 | /* everything at write_lock_level or lower must be write locked */ | |
2680 | int write_lock_level = 0; | |
9f3a7427 | 2681 | u8 lowest_level = 0; |
f7c79f30 | 2682 | int min_write_lock_level; |
d7396f07 | 2683 | int prev_cmp; |
9f3a7427 | 2684 | |
6702ed49 | 2685 | lowest_level = p->lowest_level; |
323ac95b | 2686 | WARN_ON(lowest_level && ins_len > 0); |
22b0ebda | 2687 | WARN_ON(p->nodes[0] != NULL); |
eb653de1 | 2688 | BUG_ON(!cow && ins_len); |
25179201 | 2689 | |
bd681513 | 2690 | if (ins_len < 0) { |
925baedd | 2691 | lowest_unlock = 2; |
65b51a00 | 2692 | |
bd681513 CM |
2693 | /* when we are removing items, we might have to go up to level |
2694 | * two as we update tree pointers Make sure we keep write | |
2695 | * for those levels as well | |
2696 | */ | |
2697 | write_lock_level = 2; | |
2698 | } else if (ins_len > 0) { | |
2699 | /* | |
2700 | * for inserting items, make sure we have a write lock on | |
2701 | * level 1 so we can update keys | |
2702 | */ | |
2703 | write_lock_level = 1; | |
2704 | } | |
2705 | ||
2706 | if (!cow) | |
2707 | write_lock_level = -1; | |
2708 | ||
09a2a8f9 | 2709 | if (cow && (p->keep_locks || p->lowest_level)) |
bd681513 CM |
2710 | write_lock_level = BTRFS_MAX_LEVEL; |
2711 | ||
f7c79f30 CM |
2712 | min_write_lock_level = write_lock_level; |
2713 | ||
bb803951 | 2714 | again: |
d7396f07 | 2715 | prev_cmp = -1; |
bd681513 CM |
2716 | /* |
2717 | * we try very hard to do read locks on the root | |
2718 | */ | |
2719 | root_lock = BTRFS_READ_LOCK; | |
2720 | level = 0; | |
5d4f98a2 | 2721 | if (p->search_commit_root) { |
bd681513 CM |
2722 | /* |
2723 | * the commit roots are read only | |
2724 | * so we always do read locks | |
2725 | */ | |
3f8a18cc JB |
2726 | if (p->need_commit_sem) |
2727 | down_read(&root->fs_info->commit_root_sem); | |
5d4f98a2 YZ |
2728 | b = root->commit_root; |
2729 | extent_buffer_get(b); | |
bd681513 | 2730 | level = btrfs_header_level(b); |
3f8a18cc JB |
2731 | if (p->need_commit_sem) |
2732 | up_read(&root->fs_info->commit_root_sem); | |
5d4f98a2 | 2733 | if (!p->skip_locking) |
bd681513 | 2734 | btrfs_tree_read_lock(b); |
5d4f98a2 | 2735 | } else { |
bd681513 | 2736 | if (p->skip_locking) { |
5d4f98a2 | 2737 | b = btrfs_root_node(root); |
bd681513 CM |
2738 | level = btrfs_header_level(b); |
2739 | } else { | |
2740 | /* we don't know the level of the root node | |
2741 | * until we actually have it read locked | |
2742 | */ | |
2743 | b = btrfs_read_lock_root_node(root); | |
2744 | level = btrfs_header_level(b); | |
2745 | if (level <= write_lock_level) { | |
2746 | /* whoops, must trade for write lock */ | |
2747 | btrfs_tree_read_unlock(b); | |
2748 | free_extent_buffer(b); | |
2749 | b = btrfs_lock_root_node(root); | |
2750 | root_lock = BTRFS_WRITE_LOCK; | |
2751 | ||
2752 | /* the level might have changed, check again */ | |
2753 | level = btrfs_header_level(b); | |
2754 | } | |
2755 | } | |
5d4f98a2 | 2756 | } |
bd681513 CM |
2757 | p->nodes[level] = b; |
2758 | if (!p->skip_locking) | |
2759 | p->locks[level] = root_lock; | |
925baedd | 2760 | |
eb60ceac | 2761 | while (b) { |
5f39d397 | 2762 | level = btrfs_header_level(b); |
65b51a00 CM |
2763 | |
2764 | /* | |
2765 | * setup the path here so we can release it under lock | |
2766 | * contention with the cow code | |
2767 | */ | |
02217ed2 | 2768 | if (cow) { |
c8c42864 CM |
2769 | /* |
2770 | * if we don't really need to cow this block | |
2771 | * then we don't want to set the path blocking, | |
2772 | * so we test it here | |
2773 | */ | |
5d4f98a2 | 2774 | if (!should_cow_block(trans, root, b)) |
65b51a00 | 2775 | goto cow_done; |
5d4f98a2 | 2776 | |
bd681513 CM |
2777 | /* |
2778 | * must have write locks on this node and the | |
2779 | * parent | |
2780 | */ | |
5124e00e JB |
2781 | if (level > write_lock_level || |
2782 | (level + 1 > write_lock_level && | |
2783 | level + 1 < BTRFS_MAX_LEVEL && | |
2784 | p->nodes[level + 1])) { | |
bd681513 CM |
2785 | write_lock_level = level + 1; |
2786 | btrfs_release_path(p); | |
2787 | goto again; | |
2788 | } | |
2789 | ||
160f4089 | 2790 | btrfs_set_path_blocking(p); |
33c66f43 YZ |
2791 | err = btrfs_cow_block(trans, root, b, |
2792 | p->nodes[level + 1], | |
2793 | p->slots[level + 1], &b); | |
2794 | if (err) { | |
33c66f43 | 2795 | ret = err; |
65b51a00 | 2796 | goto done; |
54aa1f4d | 2797 | } |
02217ed2 | 2798 | } |
65b51a00 | 2799 | cow_done: |
eb60ceac | 2800 | p->nodes[level] = b; |
bd681513 | 2801 | btrfs_clear_path_blocking(p, NULL, 0); |
b4ce94de CM |
2802 | |
2803 | /* | |
2804 | * we have a lock on b and as long as we aren't changing | |
2805 | * the tree, there is no way to for the items in b to change. | |
2806 | * It is safe to drop the lock on our parent before we | |
2807 | * go through the expensive btree search on b. | |
2808 | * | |
eb653de1 FDBM |
2809 | * If we're inserting or deleting (ins_len != 0), then we might |
2810 | * be changing slot zero, which may require changing the parent. | |
2811 | * So, we can't drop the lock until after we know which slot | |
2812 | * we're operating on. | |
b4ce94de | 2813 | */ |
eb653de1 FDBM |
2814 | if (!ins_len && !p->keep_locks) { |
2815 | int u = level + 1; | |
2816 | ||
2817 | if (u < BTRFS_MAX_LEVEL && p->locks[u]) { | |
2818 | btrfs_tree_unlock_rw(p->nodes[u], p->locks[u]); | |
2819 | p->locks[u] = 0; | |
2820 | } | |
2821 | } | |
b4ce94de | 2822 | |
d7396f07 | 2823 | ret = key_search(b, key, level, &prev_cmp, &slot); |
b4ce94de | 2824 | |
5f39d397 | 2825 | if (level != 0) { |
33c66f43 YZ |
2826 | int dec = 0; |
2827 | if (ret && slot > 0) { | |
2828 | dec = 1; | |
be0e5c09 | 2829 | slot -= 1; |
33c66f43 | 2830 | } |
be0e5c09 | 2831 | p->slots[level] = slot; |
33c66f43 | 2832 | err = setup_nodes_for_search(trans, root, p, b, level, |
bd681513 | 2833 | ins_len, &write_lock_level); |
33c66f43 | 2834 | if (err == -EAGAIN) |
c8c42864 | 2835 | goto again; |
33c66f43 YZ |
2836 | if (err) { |
2837 | ret = err; | |
c8c42864 | 2838 | goto done; |
33c66f43 | 2839 | } |
c8c42864 CM |
2840 | b = p->nodes[level]; |
2841 | slot = p->slots[level]; | |
b4ce94de | 2842 | |
bd681513 CM |
2843 | /* |
2844 | * slot 0 is special, if we change the key | |
2845 | * we have to update the parent pointer | |
2846 | * which means we must have a write lock | |
2847 | * on the parent | |
2848 | */ | |
eb653de1 | 2849 | if (slot == 0 && ins_len && |
bd681513 CM |
2850 | write_lock_level < level + 1) { |
2851 | write_lock_level = level + 1; | |
2852 | btrfs_release_path(p); | |
2853 | goto again; | |
2854 | } | |
2855 | ||
f7c79f30 CM |
2856 | unlock_up(p, level, lowest_unlock, |
2857 | min_write_lock_level, &write_lock_level); | |
f9efa9c7 | 2858 | |
925baedd | 2859 | if (level == lowest_level) { |
33c66f43 YZ |
2860 | if (dec) |
2861 | p->slots[level]++; | |
5b21f2ed | 2862 | goto done; |
925baedd | 2863 | } |
ca7a79ad | 2864 | |
33c66f43 | 2865 | err = read_block_for_search(trans, root, p, |
5d9e75c4 | 2866 | &b, level, slot, key, 0); |
33c66f43 | 2867 | if (err == -EAGAIN) |
c8c42864 | 2868 | goto again; |
33c66f43 YZ |
2869 | if (err) { |
2870 | ret = err; | |
76a05b35 | 2871 | goto done; |
33c66f43 | 2872 | } |
76a05b35 | 2873 | |
b4ce94de | 2874 | if (!p->skip_locking) { |
bd681513 CM |
2875 | level = btrfs_header_level(b); |
2876 | if (level <= write_lock_level) { | |
2877 | err = btrfs_try_tree_write_lock(b); | |
2878 | if (!err) { | |
2879 | btrfs_set_path_blocking(p); | |
2880 | btrfs_tree_lock(b); | |
2881 | btrfs_clear_path_blocking(p, b, | |
2882 | BTRFS_WRITE_LOCK); | |
2883 | } | |
2884 | p->locks[level] = BTRFS_WRITE_LOCK; | |
2885 | } else { | |
f82c458a | 2886 | err = btrfs_tree_read_lock_atomic(b); |
bd681513 CM |
2887 | if (!err) { |
2888 | btrfs_set_path_blocking(p); | |
2889 | btrfs_tree_read_lock(b); | |
2890 | btrfs_clear_path_blocking(p, b, | |
2891 | BTRFS_READ_LOCK); | |
2892 | } | |
2893 | p->locks[level] = BTRFS_READ_LOCK; | |
b4ce94de | 2894 | } |
bd681513 | 2895 | p->nodes[level] = b; |
b4ce94de | 2896 | } |
be0e5c09 CM |
2897 | } else { |
2898 | p->slots[level] = slot; | |
87b29b20 YZ |
2899 | if (ins_len > 0 && |
2900 | btrfs_leaf_free_space(root, b) < ins_len) { | |
bd681513 CM |
2901 | if (write_lock_level < 1) { |
2902 | write_lock_level = 1; | |
2903 | btrfs_release_path(p); | |
2904 | goto again; | |
2905 | } | |
2906 | ||
b4ce94de | 2907 | btrfs_set_path_blocking(p); |
33c66f43 YZ |
2908 | err = split_leaf(trans, root, key, |
2909 | p, ins_len, ret == 0); | |
bd681513 | 2910 | btrfs_clear_path_blocking(p, NULL, 0); |
b4ce94de | 2911 | |
33c66f43 YZ |
2912 | BUG_ON(err > 0); |
2913 | if (err) { | |
2914 | ret = err; | |
65b51a00 CM |
2915 | goto done; |
2916 | } | |
5c680ed6 | 2917 | } |
459931ec | 2918 | if (!p->search_for_split) |
f7c79f30 CM |
2919 | unlock_up(p, level, lowest_unlock, |
2920 | min_write_lock_level, &write_lock_level); | |
65b51a00 | 2921 | goto done; |
be0e5c09 CM |
2922 | } |
2923 | } | |
65b51a00 CM |
2924 | ret = 1; |
2925 | done: | |
b4ce94de CM |
2926 | /* |
2927 | * we don't really know what they plan on doing with the path | |
2928 | * from here on, so for now just mark it as blocking | |
2929 | */ | |
b9473439 CM |
2930 | if (!p->leave_spinning) |
2931 | btrfs_set_path_blocking(p); | |
5f5bc6b1 | 2932 | if (ret < 0 && !p->skip_release_on_error) |
b3b4aa74 | 2933 | btrfs_release_path(p); |
65b51a00 | 2934 | return ret; |
be0e5c09 CM |
2935 | } |
2936 | ||
5d9e75c4 JS |
2937 | /* |
2938 | * Like btrfs_search_slot, this looks for a key in the given tree. It uses the | |
2939 | * current state of the tree together with the operations recorded in the tree | |
2940 | * modification log to search for the key in a previous version of this tree, as | |
2941 | * denoted by the time_seq parameter. | |
2942 | * | |
2943 | * Naturally, there is no support for insert, delete or cow operations. | |
2944 | * | |
2945 | * The resulting path and return value will be set up as if we called | |
2946 | * btrfs_search_slot at that point in time with ins_len and cow both set to 0. | |
2947 | */ | |
2948 | int btrfs_search_old_slot(struct btrfs_root *root, struct btrfs_key *key, | |
2949 | struct btrfs_path *p, u64 time_seq) | |
2950 | { | |
2951 | struct extent_buffer *b; | |
2952 | int slot; | |
2953 | int ret; | |
2954 | int err; | |
2955 | int level; | |
2956 | int lowest_unlock = 1; | |
2957 | u8 lowest_level = 0; | |
d4b4087c | 2958 | int prev_cmp = -1; |
5d9e75c4 JS |
2959 | |
2960 | lowest_level = p->lowest_level; | |
2961 | WARN_ON(p->nodes[0] != NULL); | |
2962 | ||
2963 | if (p->search_commit_root) { | |
2964 | BUG_ON(time_seq); | |
2965 | return btrfs_search_slot(NULL, root, key, p, 0, 0); | |
2966 | } | |
2967 | ||
2968 | again: | |
5d9e75c4 | 2969 | b = get_old_root(root, time_seq); |
5d9e75c4 | 2970 | level = btrfs_header_level(b); |
5d9e75c4 JS |
2971 | p->locks[level] = BTRFS_READ_LOCK; |
2972 | ||
2973 | while (b) { | |
2974 | level = btrfs_header_level(b); | |
2975 | p->nodes[level] = b; | |
2976 | btrfs_clear_path_blocking(p, NULL, 0); | |
2977 | ||
2978 | /* | |
2979 | * we have a lock on b and as long as we aren't changing | |
2980 | * the tree, there is no way to for the items in b to change. | |
2981 | * It is safe to drop the lock on our parent before we | |
2982 | * go through the expensive btree search on b. | |
2983 | */ | |
2984 | btrfs_unlock_up_safe(p, level + 1); | |
2985 | ||
d4b4087c JB |
2986 | /* |
2987 | * Since we can unwind eb's we want to do a real search every | |
2988 | * time. | |
2989 | */ | |
2990 | prev_cmp = -1; | |
d7396f07 | 2991 | ret = key_search(b, key, level, &prev_cmp, &slot); |
5d9e75c4 JS |
2992 | |
2993 | if (level != 0) { | |
2994 | int dec = 0; | |
2995 | if (ret && slot > 0) { | |
2996 | dec = 1; | |
2997 | slot -= 1; | |
2998 | } | |
2999 | p->slots[level] = slot; | |
3000 | unlock_up(p, level, lowest_unlock, 0, NULL); | |
3001 | ||
3002 | if (level == lowest_level) { | |
3003 | if (dec) | |
3004 | p->slots[level]++; | |
3005 | goto done; | |
3006 | } | |
3007 | ||
3008 | err = read_block_for_search(NULL, root, p, &b, level, | |
3009 | slot, key, time_seq); | |
3010 | if (err == -EAGAIN) | |
3011 | goto again; | |
3012 | if (err) { | |
3013 | ret = err; | |
3014 | goto done; | |
3015 | } | |
3016 | ||
3017 | level = btrfs_header_level(b); | |
f82c458a | 3018 | err = btrfs_tree_read_lock_atomic(b); |
5d9e75c4 JS |
3019 | if (!err) { |
3020 | btrfs_set_path_blocking(p); | |
3021 | btrfs_tree_read_lock(b); | |
3022 | btrfs_clear_path_blocking(p, b, | |
3023 | BTRFS_READ_LOCK); | |
3024 | } | |
9ec72677 | 3025 | b = tree_mod_log_rewind(root->fs_info, p, b, time_seq); |
db7f3436 JB |
3026 | if (!b) { |
3027 | ret = -ENOMEM; | |
3028 | goto done; | |
3029 | } | |
5d9e75c4 JS |
3030 | p->locks[level] = BTRFS_READ_LOCK; |
3031 | p->nodes[level] = b; | |
5d9e75c4 JS |
3032 | } else { |
3033 | p->slots[level] = slot; | |
3034 | unlock_up(p, level, lowest_unlock, 0, NULL); | |
3035 | goto done; | |
3036 | } | |
3037 | } | |
3038 | ret = 1; | |
3039 | done: | |
3040 | if (!p->leave_spinning) | |
3041 | btrfs_set_path_blocking(p); | |
3042 | if (ret < 0) | |
3043 | btrfs_release_path(p); | |
3044 | ||
3045 | return ret; | |
3046 | } | |
3047 | ||
2f38b3e1 AJ |
3048 | /* |
3049 | * helper to use instead of search slot if no exact match is needed but | |
3050 | * instead the next or previous item should be returned. | |
3051 | * When find_higher is true, the next higher item is returned, the next lower | |
3052 | * otherwise. | |
3053 | * When return_any and find_higher are both true, and no higher item is found, | |
3054 | * return the next lower instead. | |
3055 | * When return_any is true and find_higher is false, and no lower item is found, | |
3056 | * return the next higher instead. | |
3057 | * It returns 0 if any item is found, 1 if none is found (tree empty), and | |
3058 | * < 0 on error | |
3059 | */ | |
3060 | int btrfs_search_slot_for_read(struct btrfs_root *root, | |
3061 | struct btrfs_key *key, struct btrfs_path *p, | |
3062 | int find_higher, int return_any) | |
3063 | { | |
3064 | int ret; | |
3065 | struct extent_buffer *leaf; | |
3066 | ||
3067 | again: | |
3068 | ret = btrfs_search_slot(NULL, root, key, p, 0, 0); | |
3069 | if (ret <= 0) | |
3070 | return ret; | |
3071 | /* | |
3072 | * a return value of 1 means the path is at the position where the | |
3073 | * item should be inserted. Normally this is the next bigger item, | |
3074 | * but in case the previous item is the last in a leaf, path points | |
3075 | * to the first free slot in the previous leaf, i.e. at an invalid | |
3076 | * item. | |
3077 | */ | |
3078 | leaf = p->nodes[0]; | |
3079 | ||
3080 | if (find_higher) { | |
3081 | if (p->slots[0] >= btrfs_header_nritems(leaf)) { | |
3082 | ret = btrfs_next_leaf(root, p); | |
3083 | if (ret <= 0) | |
3084 | return ret; | |
3085 | if (!return_any) | |
3086 | return 1; | |
3087 | /* | |
3088 | * no higher item found, return the next | |
3089 | * lower instead | |
3090 | */ | |
3091 | return_any = 0; | |
3092 | find_higher = 0; | |
3093 | btrfs_release_path(p); | |
3094 | goto again; | |
3095 | } | |
3096 | } else { | |
e6793769 AJ |
3097 | if (p->slots[0] == 0) { |
3098 | ret = btrfs_prev_leaf(root, p); | |
3099 | if (ret < 0) | |
3100 | return ret; | |
3101 | if (!ret) { | |
23c6bf6a FDBM |
3102 | leaf = p->nodes[0]; |
3103 | if (p->slots[0] == btrfs_header_nritems(leaf)) | |
3104 | p->slots[0]--; | |
e6793769 | 3105 | return 0; |
2f38b3e1 | 3106 | } |
e6793769 AJ |
3107 | if (!return_any) |
3108 | return 1; | |
3109 | /* | |
3110 | * no lower item found, return the next | |
3111 | * higher instead | |
3112 | */ | |
3113 | return_any = 0; | |
3114 | find_higher = 1; | |
3115 | btrfs_release_path(p); | |
3116 | goto again; | |
3117 | } else { | |
2f38b3e1 AJ |
3118 | --p->slots[0]; |
3119 | } | |
3120 | } | |
3121 | return 0; | |
3122 | } | |
3123 | ||
74123bd7 CM |
3124 | /* |
3125 | * adjust the pointers going up the tree, starting at level | |
3126 | * making sure the right key of each node is points to 'key'. | |
3127 | * This is used after shifting pointers to the left, so it stops | |
3128 | * fixing up pointers when a given leaf/node is not in slot 0 of the | |
3129 | * higher levels | |
aa5d6bed | 3130 | * |
74123bd7 | 3131 | */ |
b7a0365e DD |
3132 | static void fixup_low_keys(struct btrfs_fs_info *fs_info, |
3133 | struct btrfs_path *path, | |
143bede5 | 3134 | struct btrfs_disk_key *key, int level) |
be0e5c09 CM |
3135 | { |
3136 | int i; | |
5f39d397 CM |
3137 | struct extent_buffer *t; |
3138 | ||
234b63a0 | 3139 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { |
be0e5c09 | 3140 | int tslot = path->slots[i]; |
eb60ceac | 3141 | if (!path->nodes[i]) |
be0e5c09 | 3142 | break; |
5f39d397 | 3143 | t = path->nodes[i]; |
b7a0365e | 3144 | tree_mod_log_set_node_key(fs_info, t, tslot, 1); |
5f39d397 | 3145 | btrfs_set_node_key(t, key, tslot); |
d6025579 | 3146 | btrfs_mark_buffer_dirty(path->nodes[i]); |
be0e5c09 CM |
3147 | if (tslot != 0) |
3148 | break; | |
3149 | } | |
3150 | } | |
3151 | ||
31840ae1 ZY |
3152 | /* |
3153 | * update item key. | |
3154 | * | |
3155 | * This function isn't completely safe. It's the caller's responsibility | |
3156 | * that the new key won't break the order | |
3157 | */ | |
b7a0365e DD |
3158 | void btrfs_set_item_key_safe(struct btrfs_fs_info *fs_info, |
3159 | struct btrfs_path *path, | |
143bede5 | 3160 | struct btrfs_key *new_key) |
31840ae1 ZY |
3161 | { |
3162 | struct btrfs_disk_key disk_key; | |
3163 | struct extent_buffer *eb; | |
3164 | int slot; | |
3165 | ||
3166 | eb = path->nodes[0]; | |
3167 | slot = path->slots[0]; | |
3168 | if (slot > 0) { | |
3169 | btrfs_item_key(eb, &disk_key, slot - 1); | |
143bede5 | 3170 | BUG_ON(comp_keys(&disk_key, new_key) >= 0); |
31840ae1 ZY |
3171 | } |
3172 | if (slot < btrfs_header_nritems(eb) - 1) { | |
3173 | btrfs_item_key(eb, &disk_key, slot + 1); | |
143bede5 | 3174 | BUG_ON(comp_keys(&disk_key, new_key) <= 0); |
31840ae1 ZY |
3175 | } |
3176 | ||
3177 | btrfs_cpu_key_to_disk(&disk_key, new_key); | |
3178 | btrfs_set_item_key(eb, &disk_key, slot); | |
3179 | btrfs_mark_buffer_dirty(eb); | |
3180 | if (slot == 0) | |
b7a0365e | 3181 | fixup_low_keys(fs_info, path, &disk_key, 1); |
31840ae1 ZY |
3182 | } |
3183 | ||
74123bd7 CM |
3184 | /* |
3185 | * try to push data from one node into the next node left in the | |
79f95c82 | 3186 | * tree. |
aa5d6bed CM |
3187 | * |
3188 | * returns 0 if some ptrs were pushed left, < 0 if there was some horrible | |
3189 | * error, and > 0 if there was no room in the left hand block. | |
74123bd7 | 3190 | */ |
98ed5174 CM |
3191 | static int push_node_left(struct btrfs_trans_handle *trans, |
3192 | struct btrfs_root *root, struct extent_buffer *dst, | |
971a1f66 | 3193 | struct extent_buffer *src, int empty) |
be0e5c09 | 3194 | { |
be0e5c09 | 3195 | int push_items = 0; |
bb803951 CM |
3196 | int src_nritems; |
3197 | int dst_nritems; | |
aa5d6bed | 3198 | int ret = 0; |
be0e5c09 | 3199 | |
5f39d397 CM |
3200 | src_nritems = btrfs_header_nritems(src); |
3201 | dst_nritems = btrfs_header_nritems(dst); | |
123abc88 | 3202 | push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems; |
7bb86316 CM |
3203 | WARN_ON(btrfs_header_generation(src) != trans->transid); |
3204 | WARN_ON(btrfs_header_generation(dst) != trans->transid); | |
54aa1f4d | 3205 | |
bce4eae9 | 3206 | if (!empty && src_nritems <= 8) |
971a1f66 CM |
3207 | return 1; |
3208 | ||
d397712b | 3209 | if (push_items <= 0) |
be0e5c09 CM |
3210 | return 1; |
3211 | ||
bce4eae9 | 3212 | if (empty) { |
971a1f66 | 3213 | push_items = min(src_nritems, push_items); |
bce4eae9 CM |
3214 | if (push_items < src_nritems) { |
3215 | /* leave at least 8 pointers in the node if | |
3216 | * we aren't going to empty it | |
3217 | */ | |
3218 | if (src_nritems - push_items < 8) { | |
3219 | if (push_items <= 8) | |
3220 | return 1; | |
3221 | push_items -= 8; | |
3222 | } | |
3223 | } | |
3224 | } else | |
3225 | push_items = min(src_nritems - 8, push_items); | |
79f95c82 | 3226 | |
5de865ee FDBM |
3227 | ret = tree_mod_log_eb_copy(root->fs_info, dst, src, dst_nritems, 0, |
3228 | push_items); | |
3229 | if (ret) { | |
3230 | btrfs_abort_transaction(trans, root, ret); | |
3231 | return ret; | |
3232 | } | |
5f39d397 CM |
3233 | copy_extent_buffer(dst, src, |
3234 | btrfs_node_key_ptr_offset(dst_nritems), | |
3235 | btrfs_node_key_ptr_offset(0), | |
d397712b | 3236 | push_items * sizeof(struct btrfs_key_ptr)); |
5f39d397 | 3237 | |
bb803951 | 3238 | if (push_items < src_nritems) { |
57911b8b JS |
3239 | /* |
3240 | * don't call tree_mod_log_eb_move here, key removal was already | |
3241 | * fully logged by tree_mod_log_eb_copy above. | |
3242 | */ | |
5f39d397 CM |
3243 | memmove_extent_buffer(src, btrfs_node_key_ptr_offset(0), |
3244 | btrfs_node_key_ptr_offset(push_items), | |
3245 | (src_nritems - push_items) * | |
3246 | sizeof(struct btrfs_key_ptr)); | |
3247 | } | |
3248 | btrfs_set_header_nritems(src, src_nritems - push_items); | |
3249 | btrfs_set_header_nritems(dst, dst_nritems + push_items); | |
3250 | btrfs_mark_buffer_dirty(src); | |
3251 | btrfs_mark_buffer_dirty(dst); | |
31840ae1 | 3252 | |
79f95c82 CM |
3253 | return ret; |
3254 | } | |
3255 | ||
3256 | /* | |
3257 | * try to push data from one node into the next node right in the | |
3258 | * tree. | |
3259 | * | |
3260 | * returns 0 if some ptrs were pushed, < 0 if there was some horrible | |
3261 | * error, and > 0 if there was no room in the right hand block. | |
3262 | * | |
3263 | * this will only push up to 1/2 the contents of the left node over | |
3264 | */ | |
5f39d397 CM |
3265 | static int balance_node_right(struct btrfs_trans_handle *trans, |
3266 | struct btrfs_root *root, | |
3267 | struct extent_buffer *dst, | |
3268 | struct extent_buffer *src) | |
79f95c82 | 3269 | { |
79f95c82 CM |
3270 | int push_items = 0; |
3271 | int max_push; | |
3272 | int src_nritems; | |
3273 | int dst_nritems; | |
3274 | int ret = 0; | |
79f95c82 | 3275 | |
7bb86316 CM |
3276 | WARN_ON(btrfs_header_generation(src) != trans->transid); |
3277 | WARN_ON(btrfs_header_generation(dst) != trans->transid); | |
3278 | ||
5f39d397 CM |
3279 | src_nritems = btrfs_header_nritems(src); |
3280 | dst_nritems = btrfs_header_nritems(dst); | |
123abc88 | 3281 | push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems; |
d397712b | 3282 | if (push_items <= 0) |
79f95c82 | 3283 | return 1; |
bce4eae9 | 3284 | |
d397712b | 3285 | if (src_nritems < 4) |
bce4eae9 | 3286 | return 1; |
79f95c82 CM |
3287 | |
3288 | max_push = src_nritems / 2 + 1; | |
3289 | /* don't try to empty the node */ | |
d397712b | 3290 | if (max_push >= src_nritems) |
79f95c82 | 3291 | return 1; |
252c38f0 | 3292 | |
79f95c82 CM |
3293 | if (max_push < push_items) |
3294 | push_items = max_push; | |
3295 | ||
f230475e | 3296 | tree_mod_log_eb_move(root->fs_info, dst, push_items, 0, dst_nritems); |
5f39d397 CM |
3297 | memmove_extent_buffer(dst, btrfs_node_key_ptr_offset(push_items), |
3298 | btrfs_node_key_ptr_offset(0), | |
3299 | (dst_nritems) * | |
3300 | sizeof(struct btrfs_key_ptr)); | |
d6025579 | 3301 | |
5de865ee FDBM |
3302 | ret = tree_mod_log_eb_copy(root->fs_info, dst, src, 0, |
3303 | src_nritems - push_items, push_items); | |
3304 | if (ret) { | |
3305 | btrfs_abort_transaction(trans, root, ret); | |
3306 | return ret; | |
3307 | } | |
5f39d397 CM |
3308 | copy_extent_buffer(dst, src, |
3309 | btrfs_node_key_ptr_offset(0), | |
3310 | btrfs_node_key_ptr_offset(src_nritems - push_items), | |
d397712b | 3311 | push_items * sizeof(struct btrfs_key_ptr)); |
79f95c82 | 3312 | |
5f39d397 CM |
3313 | btrfs_set_header_nritems(src, src_nritems - push_items); |
3314 | btrfs_set_header_nritems(dst, dst_nritems + push_items); | |
79f95c82 | 3315 | |
5f39d397 CM |
3316 | btrfs_mark_buffer_dirty(src); |
3317 | btrfs_mark_buffer_dirty(dst); | |
31840ae1 | 3318 | |
aa5d6bed | 3319 | return ret; |
be0e5c09 CM |
3320 | } |
3321 | ||
97571fd0 CM |
3322 | /* |
3323 | * helper function to insert a new root level in the tree. | |
3324 | * A new node is allocated, and a single item is inserted to | |
3325 | * point to the existing root | |
aa5d6bed CM |
3326 | * |
3327 | * returns zero on success or < 0 on failure. | |
97571fd0 | 3328 | */ |
d397712b | 3329 | static noinline int insert_new_root(struct btrfs_trans_handle *trans, |
5f39d397 | 3330 | struct btrfs_root *root, |
fdd99c72 | 3331 | struct btrfs_path *path, int level) |
5c680ed6 | 3332 | { |
7bb86316 | 3333 | u64 lower_gen; |
5f39d397 CM |
3334 | struct extent_buffer *lower; |
3335 | struct extent_buffer *c; | |
925baedd | 3336 | struct extent_buffer *old; |
5f39d397 | 3337 | struct btrfs_disk_key lower_key; |
5c680ed6 CM |
3338 | |
3339 | BUG_ON(path->nodes[level]); | |
3340 | BUG_ON(path->nodes[level-1] != root->node); | |
3341 | ||
7bb86316 CM |
3342 | lower = path->nodes[level-1]; |
3343 | if (level == 1) | |
3344 | btrfs_item_key(lower, &lower_key, 0); | |
3345 | else | |
3346 | btrfs_node_key(lower, &lower_key, 0); | |
3347 | ||
4d75f8a9 DS |
3348 | c = btrfs_alloc_tree_block(trans, root, 0, root->root_key.objectid, |
3349 | &lower_key, level, root->node->start, 0); | |
5f39d397 CM |
3350 | if (IS_ERR(c)) |
3351 | return PTR_ERR(c); | |
925baedd | 3352 | |
f0486c68 YZ |
3353 | root_add_used(root, root->nodesize); |
3354 | ||
5d4f98a2 | 3355 | memset_extent_buffer(c, 0, 0, sizeof(struct btrfs_header)); |
5f39d397 CM |
3356 | btrfs_set_header_nritems(c, 1); |
3357 | btrfs_set_header_level(c, level); | |
db94535d | 3358 | btrfs_set_header_bytenr(c, c->start); |
5f39d397 | 3359 | btrfs_set_header_generation(c, trans->transid); |
5d4f98a2 | 3360 | btrfs_set_header_backref_rev(c, BTRFS_MIXED_BACKREF_REV); |
5f39d397 | 3361 | btrfs_set_header_owner(c, root->root_key.objectid); |
5f39d397 | 3362 | |
0a4e5586 | 3363 | write_extent_buffer(c, root->fs_info->fsid, btrfs_header_fsid(), |
5f39d397 | 3364 | BTRFS_FSID_SIZE); |
e17cade2 CM |
3365 | |
3366 | write_extent_buffer(c, root->fs_info->chunk_tree_uuid, | |
b308bc2f | 3367 | btrfs_header_chunk_tree_uuid(c), BTRFS_UUID_SIZE); |
e17cade2 | 3368 | |
5f39d397 | 3369 | btrfs_set_node_key(c, &lower_key, 0); |
db94535d | 3370 | btrfs_set_node_blockptr(c, 0, lower->start); |
7bb86316 | 3371 | lower_gen = btrfs_header_generation(lower); |
31840ae1 | 3372 | WARN_ON(lower_gen != trans->transid); |
7bb86316 CM |
3373 | |
3374 | btrfs_set_node_ptr_generation(c, 0, lower_gen); | |
d5719762 | 3375 | |
5f39d397 | 3376 | btrfs_mark_buffer_dirty(c); |
d5719762 | 3377 | |
925baedd | 3378 | old = root->node; |
fdd99c72 | 3379 | tree_mod_log_set_root_pointer(root, c, 0); |
240f62c8 | 3380 | rcu_assign_pointer(root->node, c); |
925baedd CM |
3381 | |
3382 | /* the super has an extra ref to root->node */ | |
3383 | free_extent_buffer(old); | |
3384 | ||
0b86a832 | 3385 | add_root_to_dirty_list(root); |
5f39d397 CM |
3386 | extent_buffer_get(c); |
3387 | path->nodes[level] = c; | |
95449a16 | 3388 | path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING; |
5c680ed6 CM |
3389 | path->slots[level] = 0; |
3390 | return 0; | |
3391 | } | |
3392 | ||
74123bd7 CM |
3393 | /* |
3394 | * worker function to insert a single pointer in a node. | |
3395 | * the node should have enough room for the pointer already | |
97571fd0 | 3396 | * |
74123bd7 CM |
3397 | * slot and level indicate where you want the key to go, and |
3398 | * blocknr is the block the key points to. | |
3399 | */ | |
143bede5 JM |
3400 | static void insert_ptr(struct btrfs_trans_handle *trans, |
3401 | struct btrfs_root *root, struct btrfs_path *path, | |
3402 | struct btrfs_disk_key *key, u64 bytenr, | |
c3e06965 | 3403 | int slot, int level) |
74123bd7 | 3404 | { |
5f39d397 | 3405 | struct extent_buffer *lower; |
74123bd7 | 3406 | int nritems; |
f3ea38da | 3407 | int ret; |
5c680ed6 CM |
3408 | |
3409 | BUG_ON(!path->nodes[level]); | |
f0486c68 | 3410 | btrfs_assert_tree_locked(path->nodes[level]); |
5f39d397 CM |
3411 | lower = path->nodes[level]; |
3412 | nritems = btrfs_header_nritems(lower); | |
c293498b | 3413 | BUG_ON(slot > nritems); |
143bede5 | 3414 | BUG_ON(nritems == BTRFS_NODEPTRS_PER_BLOCK(root)); |
74123bd7 | 3415 | if (slot != nritems) { |
c3e06965 | 3416 | if (level) |
f3ea38da JS |
3417 | tree_mod_log_eb_move(root->fs_info, lower, slot + 1, |
3418 | slot, nritems - slot); | |
5f39d397 CM |
3419 | memmove_extent_buffer(lower, |
3420 | btrfs_node_key_ptr_offset(slot + 1), | |
3421 | btrfs_node_key_ptr_offset(slot), | |
d6025579 | 3422 | (nritems - slot) * sizeof(struct btrfs_key_ptr)); |
74123bd7 | 3423 | } |
c3e06965 | 3424 | if (level) { |
f3ea38da | 3425 | ret = tree_mod_log_insert_key(root->fs_info, lower, slot, |
c8cc6341 | 3426 | MOD_LOG_KEY_ADD, GFP_NOFS); |
f3ea38da JS |
3427 | BUG_ON(ret < 0); |
3428 | } | |
5f39d397 | 3429 | btrfs_set_node_key(lower, key, slot); |
db94535d | 3430 | btrfs_set_node_blockptr(lower, slot, bytenr); |
74493f7a CM |
3431 | WARN_ON(trans->transid == 0); |
3432 | btrfs_set_node_ptr_generation(lower, slot, trans->transid); | |
5f39d397 CM |
3433 | btrfs_set_header_nritems(lower, nritems + 1); |
3434 | btrfs_mark_buffer_dirty(lower); | |
74123bd7 CM |
3435 | } |
3436 | ||
97571fd0 CM |
3437 | /* |
3438 | * split the node at the specified level in path in two. | |
3439 | * The path is corrected to point to the appropriate node after the split | |
3440 | * | |
3441 | * Before splitting this tries to make some room in the node by pushing | |
3442 | * left and right, if either one works, it returns right away. | |
aa5d6bed CM |
3443 | * |
3444 | * returns 0 on success and < 0 on failure | |
97571fd0 | 3445 | */ |
e02119d5 CM |
3446 | static noinline int split_node(struct btrfs_trans_handle *trans, |
3447 | struct btrfs_root *root, | |
3448 | struct btrfs_path *path, int level) | |
be0e5c09 | 3449 | { |
5f39d397 CM |
3450 | struct extent_buffer *c; |
3451 | struct extent_buffer *split; | |
3452 | struct btrfs_disk_key disk_key; | |
be0e5c09 | 3453 | int mid; |
5c680ed6 | 3454 | int ret; |
7518a238 | 3455 | u32 c_nritems; |
eb60ceac | 3456 | |
5f39d397 | 3457 | c = path->nodes[level]; |
7bb86316 | 3458 | WARN_ON(btrfs_header_generation(c) != trans->transid); |
5f39d397 | 3459 | if (c == root->node) { |
d9abbf1c | 3460 | /* |
90f8d62e JS |
3461 | * trying to split the root, lets make a new one |
3462 | * | |
fdd99c72 | 3463 | * tree mod log: We don't log_removal old root in |
90f8d62e JS |
3464 | * insert_new_root, because that root buffer will be kept as a |
3465 | * normal node. We are going to log removal of half of the | |
3466 | * elements below with tree_mod_log_eb_copy. We're holding a | |
3467 | * tree lock on the buffer, which is why we cannot race with | |
3468 | * other tree_mod_log users. | |
d9abbf1c | 3469 | */ |
fdd99c72 | 3470 | ret = insert_new_root(trans, root, path, level + 1); |
5c680ed6 CM |
3471 | if (ret) |
3472 | return ret; | |
b3612421 | 3473 | } else { |
e66f709b | 3474 | ret = push_nodes_for_insert(trans, root, path, level); |
5f39d397 CM |
3475 | c = path->nodes[level]; |
3476 | if (!ret && btrfs_header_nritems(c) < | |
c448acf0 | 3477 | BTRFS_NODEPTRS_PER_BLOCK(root) - 3) |
e66f709b | 3478 | return 0; |
54aa1f4d CM |
3479 | if (ret < 0) |
3480 | return ret; | |
be0e5c09 | 3481 | } |
e66f709b | 3482 | |
5f39d397 | 3483 | c_nritems = btrfs_header_nritems(c); |
5d4f98a2 YZ |
3484 | mid = (c_nritems + 1) / 2; |
3485 | btrfs_node_key(c, &disk_key, mid); | |
7bb86316 | 3486 | |
4d75f8a9 DS |
3487 | split = btrfs_alloc_tree_block(trans, root, 0, root->root_key.objectid, |
3488 | &disk_key, level, c->start, 0); | |
5f39d397 CM |
3489 | if (IS_ERR(split)) |
3490 | return PTR_ERR(split); | |
3491 | ||
f0486c68 YZ |
3492 | root_add_used(root, root->nodesize); |
3493 | ||
5d4f98a2 | 3494 | memset_extent_buffer(split, 0, 0, sizeof(struct btrfs_header)); |
5f39d397 | 3495 | btrfs_set_header_level(split, btrfs_header_level(c)); |
db94535d | 3496 | btrfs_set_header_bytenr(split, split->start); |
5f39d397 | 3497 | btrfs_set_header_generation(split, trans->transid); |
5d4f98a2 | 3498 | btrfs_set_header_backref_rev(split, BTRFS_MIXED_BACKREF_REV); |
5f39d397 CM |
3499 | btrfs_set_header_owner(split, root->root_key.objectid); |
3500 | write_extent_buffer(split, root->fs_info->fsid, | |
0a4e5586 | 3501 | btrfs_header_fsid(), BTRFS_FSID_SIZE); |
e17cade2 | 3502 | write_extent_buffer(split, root->fs_info->chunk_tree_uuid, |
b308bc2f | 3503 | btrfs_header_chunk_tree_uuid(split), |
e17cade2 | 3504 | BTRFS_UUID_SIZE); |
54aa1f4d | 3505 | |
5de865ee FDBM |
3506 | ret = tree_mod_log_eb_copy(root->fs_info, split, c, 0, |
3507 | mid, c_nritems - mid); | |
3508 | if (ret) { | |
3509 | btrfs_abort_transaction(trans, root, ret); | |
3510 | return ret; | |
3511 | } | |
5f39d397 CM |
3512 | copy_extent_buffer(split, c, |
3513 | btrfs_node_key_ptr_offset(0), | |
3514 | btrfs_node_key_ptr_offset(mid), | |
3515 | (c_nritems - mid) * sizeof(struct btrfs_key_ptr)); | |
3516 | btrfs_set_header_nritems(split, c_nritems - mid); | |
3517 | btrfs_set_header_nritems(c, mid); | |
aa5d6bed CM |
3518 | ret = 0; |
3519 | ||
5f39d397 CM |
3520 | btrfs_mark_buffer_dirty(c); |
3521 | btrfs_mark_buffer_dirty(split); | |
3522 | ||
143bede5 | 3523 | insert_ptr(trans, root, path, &disk_key, split->start, |
c3e06965 | 3524 | path->slots[level + 1] + 1, level + 1); |
aa5d6bed | 3525 | |
5de08d7d | 3526 | if (path->slots[level] >= mid) { |
5c680ed6 | 3527 | path->slots[level] -= mid; |
925baedd | 3528 | btrfs_tree_unlock(c); |
5f39d397 CM |
3529 | free_extent_buffer(c); |
3530 | path->nodes[level] = split; | |
5c680ed6 CM |
3531 | path->slots[level + 1] += 1; |
3532 | } else { | |
925baedd | 3533 | btrfs_tree_unlock(split); |
5f39d397 | 3534 | free_extent_buffer(split); |
be0e5c09 | 3535 | } |
aa5d6bed | 3536 | return ret; |
be0e5c09 CM |
3537 | } |
3538 | ||
74123bd7 CM |
3539 | /* |
3540 | * how many bytes are required to store the items in a leaf. start | |
3541 | * and nr indicate which items in the leaf to check. This totals up the | |
3542 | * space used both by the item structs and the item data | |
3543 | */ | |
5f39d397 | 3544 | static int leaf_space_used(struct extent_buffer *l, int start, int nr) |
be0e5c09 | 3545 | { |
41be1f3b JB |
3546 | struct btrfs_item *start_item; |
3547 | struct btrfs_item *end_item; | |
3548 | struct btrfs_map_token token; | |
be0e5c09 | 3549 | int data_len; |
5f39d397 | 3550 | int nritems = btrfs_header_nritems(l); |
d4dbff95 | 3551 | int end = min(nritems, start + nr) - 1; |
be0e5c09 CM |
3552 | |
3553 | if (!nr) | |
3554 | return 0; | |
41be1f3b | 3555 | btrfs_init_map_token(&token); |
dd3cc16b RK |
3556 | start_item = btrfs_item_nr(start); |
3557 | end_item = btrfs_item_nr(end); | |
41be1f3b JB |
3558 | data_len = btrfs_token_item_offset(l, start_item, &token) + |
3559 | btrfs_token_item_size(l, start_item, &token); | |
3560 | data_len = data_len - btrfs_token_item_offset(l, end_item, &token); | |
0783fcfc | 3561 | data_len += sizeof(struct btrfs_item) * nr; |
d4dbff95 | 3562 | WARN_ON(data_len < 0); |
be0e5c09 CM |
3563 | return data_len; |
3564 | } | |
3565 | ||
d4dbff95 CM |
3566 | /* |
3567 | * The space between the end of the leaf items and | |
3568 | * the start of the leaf data. IOW, how much room | |
3569 | * the leaf has left for both items and data | |
3570 | */ | |
d397712b | 3571 | noinline int btrfs_leaf_free_space(struct btrfs_root *root, |
e02119d5 | 3572 | struct extent_buffer *leaf) |
d4dbff95 | 3573 | { |
5f39d397 CM |
3574 | int nritems = btrfs_header_nritems(leaf); |
3575 | int ret; | |
3576 | ret = BTRFS_LEAF_DATA_SIZE(root) - leaf_space_used(leaf, 0, nritems); | |
3577 | if (ret < 0) { | |
efe120a0 FH |
3578 | btrfs_crit(root->fs_info, |
3579 | "leaf free space ret %d, leaf data size %lu, used %d nritems %d", | |
ae2f5411 | 3580 | ret, (unsigned long) BTRFS_LEAF_DATA_SIZE(root), |
5f39d397 CM |
3581 | leaf_space_used(leaf, 0, nritems), nritems); |
3582 | } | |
3583 | return ret; | |
d4dbff95 CM |
3584 | } |
3585 | ||
99d8f83c CM |
3586 | /* |
3587 | * min slot controls the lowest index we're willing to push to the | |
3588 | * right. We'll push up to and including min_slot, but no lower | |
3589 | */ | |
44871b1b CM |
3590 | static noinline int __push_leaf_right(struct btrfs_trans_handle *trans, |
3591 | struct btrfs_root *root, | |
3592 | struct btrfs_path *path, | |
3593 | int data_size, int empty, | |
3594 | struct extent_buffer *right, | |
99d8f83c CM |
3595 | int free_space, u32 left_nritems, |
3596 | u32 min_slot) | |
00ec4c51 | 3597 | { |
5f39d397 | 3598 | struct extent_buffer *left = path->nodes[0]; |
44871b1b | 3599 | struct extent_buffer *upper = path->nodes[1]; |
cfed81a0 | 3600 | struct btrfs_map_token token; |
5f39d397 | 3601 | struct btrfs_disk_key disk_key; |
00ec4c51 | 3602 | int slot; |
34a38218 | 3603 | u32 i; |
00ec4c51 CM |
3604 | int push_space = 0; |
3605 | int push_items = 0; | |
0783fcfc | 3606 | struct btrfs_item *item; |
34a38218 | 3607 | u32 nr; |
7518a238 | 3608 | u32 right_nritems; |
5f39d397 | 3609 | u32 data_end; |
db94535d | 3610 | u32 this_item_size; |
00ec4c51 | 3611 | |
cfed81a0 CM |
3612 | btrfs_init_map_token(&token); |
3613 | ||
34a38218 CM |
3614 | if (empty) |
3615 | nr = 0; | |
3616 | else | |
99d8f83c | 3617 | nr = max_t(u32, 1, min_slot); |
34a38218 | 3618 | |
31840ae1 | 3619 | if (path->slots[0] >= left_nritems) |
87b29b20 | 3620 | push_space += data_size; |
31840ae1 | 3621 | |
44871b1b | 3622 | slot = path->slots[1]; |
34a38218 CM |
3623 | i = left_nritems - 1; |
3624 | while (i >= nr) { | |
dd3cc16b | 3625 | item = btrfs_item_nr(i); |
db94535d | 3626 | |
31840ae1 ZY |
3627 | if (!empty && push_items > 0) { |
3628 | if (path->slots[0] > i) | |
3629 | break; | |
3630 | if (path->slots[0] == i) { | |
3631 | int space = btrfs_leaf_free_space(root, left); | |
3632 | if (space + push_space * 2 > free_space) | |
3633 | break; | |
3634 | } | |
3635 | } | |
3636 | ||
00ec4c51 | 3637 | if (path->slots[0] == i) |
87b29b20 | 3638 | push_space += data_size; |
db94535d | 3639 | |
db94535d CM |
3640 | this_item_size = btrfs_item_size(left, item); |
3641 | if (this_item_size + sizeof(*item) + push_space > free_space) | |
00ec4c51 | 3642 | break; |
31840ae1 | 3643 | |
00ec4c51 | 3644 | push_items++; |
db94535d | 3645 | push_space += this_item_size + sizeof(*item); |
34a38218 CM |
3646 | if (i == 0) |
3647 | break; | |
3648 | i--; | |
db94535d | 3649 | } |
5f39d397 | 3650 | |
925baedd CM |
3651 | if (push_items == 0) |
3652 | goto out_unlock; | |
5f39d397 | 3653 | |
6c1500f2 | 3654 | WARN_ON(!empty && push_items == left_nritems); |
5f39d397 | 3655 | |
00ec4c51 | 3656 | /* push left to right */ |
5f39d397 | 3657 | right_nritems = btrfs_header_nritems(right); |
34a38218 | 3658 | |
5f39d397 | 3659 | push_space = btrfs_item_end_nr(left, left_nritems - push_items); |
123abc88 | 3660 | push_space -= leaf_data_end(root, left); |
5f39d397 | 3661 | |
00ec4c51 | 3662 | /* make room in the right data area */ |
5f39d397 CM |
3663 | data_end = leaf_data_end(root, right); |
3664 | memmove_extent_buffer(right, | |
3665 | btrfs_leaf_data(right) + data_end - push_space, | |
3666 | btrfs_leaf_data(right) + data_end, | |
3667 | BTRFS_LEAF_DATA_SIZE(root) - data_end); | |
3668 | ||
00ec4c51 | 3669 | /* copy from the left data area */ |
5f39d397 | 3670 | copy_extent_buffer(right, left, btrfs_leaf_data(right) + |
d6025579 CM |
3671 | BTRFS_LEAF_DATA_SIZE(root) - push_space, |
3672 | btrfs_leaf_data(left) + leaf_data_end(root, left), | |
3673 | push_space); | |
5f39d397 CM |
3674 | |
3675 | memmove_extent_buffer(right, btrfs_item_nr_offset(push_items), | |
3676 | btrfs_item_nr_offset(0), | |
3677 | right_nritems * sizeof(struct btrfs_item)); | |
3678 | ||
00ec4c51 | 3679 | /* copy the items from left to right */ |
5f39d397 CM |
3680 | copy_extent_buffer(right, left, btrfs_item_nr_offset(0), |
3681 | btrfs_item_nr_offset(left_nritems - push_items), | |
3682 | push_items * sizeof(struct btrfs_item)); | |
00ec4c51 CM |
3683 | |
3684 | /* update the item pointers */ | |
7518a238 | 3685 | right_nritems += push_items; |
5f39d397 | 3686 | btrfs_set_header_nritems(right, right_nritems); |
123abc88 | 3687 | push_space = BTRFS_LEAF_DATA_SIZE(root); |
7518a238 | 3688 | for (i = 0; i < right_nritems; i++) { |
dd3cc16b | 3689 | item = btrfs_item_nr(i); |
cfed81a0 CM |
3690 | push_space -= btrfs_token_item_size(right, item, &token); |
3691 | btrfs_set_token_item_offset(right, item, push_space, &token); | |
db94535d CM |
3692 | } |
3693 | ||
7518a238 | 3694 | left_nritems -= push_items; |
5f39d397 | 3695 | btrfs_set_header_nritems(left, left_nritems); |
00ec4c51 | 3696 | |
34a38218 CM |
3697 | if (left_nritems) |
3698 | btrfs_mark_buffer_dirty(left); | |
f0486c68 | 3699 | else |
01d58472 | 3700 | clean_tree_block(trans, root->fs_info, left); |
f0486c68 | 3701 | |
5f39d397 | 3702 | btrfs_mark_buffer_dirty(right); |
a429e513 | 3703 | |
5f39d397 CM |
3704 | btrfs_item_key(right, &disk_key, 0); |
3705 | btrfs_set_node_key(upper, &disk_key, slot + 1); | |
d6025579 | 3706 | btrfs_mark_buffer_dirty(upper); |
02217ed2 | 3707 | |
00ec4c51 | 3708 | /* then fixup the leaf pointer in the path */ |
7518a238 CM |
3709 | if (path->slots[0] >= left_nritems) { |
3710 | path->slots[0] -= left_nritems; | |
925baedd | 3711 | if (btrfs_header_nritems(path->nodes[0]) == 0) |
01d58472 | 3712 | clean_tree_block(trans, root->fs_info, path->nodes[0]); |
925baedd | 3713 | btrfs_tree_unlock(path->nodes[0]); |
5f39d397 CM |
3714 | free_extent_buffer(path->nodes[0]); |
3715 | path->nodes[0] = right; | |
00ec4c51 CM |
3716 | path->slots[1] += 1; |
3717 | } else { | |
925baedd | 3718 | btrfs_tree_unlock(right); |
5f39d397 | 3719 | free_extent_buffer(right); |
00ec4c51 CM |
3720 | } |
3721 | return 0; | |
925baedd CM |
3722 | |
3723 | out_unlock: | |
3724 | btrfs_tree_unlock(right); | |
3725 | free_extent_buffer(right); | |
3726 | return 1; | |
00ec4c51 | 3727 | } |
925baedd | 3728 | |
44871b1b CM |
3729 | /* |
3730 | * push some data in the path leaf to the right, trying to free up at | |
3731 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
3732 | * | |
3733 | * returns 1 if the push failed because the other node didn't have enough | |
3734 | * room, 0 if everything worked out and < 0 if there were major errors. | |
99d8f83c CM |
3735 | * |
3736 | * this will push starting from min_slot to the end of the leaf. It won't | |
3737 | * push any slot lower than min_slot | |
44871b1b CM |
3738 | */ |
3739 | static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root | |
99d8f83c CM |
3740 | *root, struct btrfs_path *path, |
3741 | int min_data_size, int data_size, | |
3742 | int empty, u32 min_slot) | |
44871b1b CM |
3743 | { |
3744 | struct extent_buffer *left = path->nodes[0]; | |
3745 | struct extent_buffer *right; | |
3746 | struct extent_buffer *upper; | |
3747 | int slot; | |
3748 | int free_space; | |
3749 | u32 left_nritems; | |
3750 | int ret; | |
3751 | ||
3752 | if (!path->nodes[1]) | |
3753 | return 1; | |
3754 | ||
3755 | slot = path->slots[1]; | |
3756 | upper = path->nodes[1]; | |
3757 | if (slot >= btrfs_header_nritems(upper) - 1) | |
3758 | return 1; | |
3759 | ||
3760 | btrfs_assert_tree_locked(path->nodes[1]); | |
3761 | ||
3762 | right = read_node_slot(root, upper, slot + 1); | |
91ca338d TI |
3763 | if (right == NULL) |
3764 | return 1; | |
3765 | ||
44871b1b CM |
3766 | btrfs_tree_lock(right); |
3767 | btrfs_set_lock_blocking(right); | |
3768 | ||
3769 | free_space = btrfs_leaf_free_space(root, right); | |
3770 | if (free_space < data_size) | |
3771 | goto out_unlock; | |
3772 | ||
3773 | /* cow and double check */ | |
3774 | ret = btrfs_cow_block(trans, root, right, upper, | |
3775 | slot + 1, &right); | |
3776 | if (ret) | |
3777 | goto out_unlock; | |
3778 | ||
3779 | free_space = btrfs_leaf_free_space(root, right); | |
3780 | if (free_space < data_size) | |
3781 | goto out_unlock; | |
3782 | ||
3783 | left_nritems = btrfs_header_nritems(left); | |
3784 | if (left_nritems == 0) | |
3785 | goto out_unlock; | |
3786 | ||
2ef1fed2 FDBM |
3787 | if (path->slots[0] == left_nritems && !empty) { |
3788 | /* Key greater than all keys in the leaf, right neighbor has | |
3789 | * enough room for it and we're not emptying our leaf to delete | |
3790 | * it, therefore use right neighbor to insert the new item and | |
3791 | * no need to touch/dirty our left leaft. */ | |
3792 | btrfs_tree_unlock(left); | |
3793 | free_extent_buffer(left); | |
3794 | path->nodes[0] = right; | |
3795 | path->slots[0] = 0; | |
3796 | path->slots[1]++; | |
3797 | return 0; | |
3798 | } | |
3799 | ||
99d8f83c CM |
3800 | return __push_leaf_right(trans, root, path, min_data_size, empty, |
3801 | right, free_space, left_nritems, min_slot); | |
44871b1b CM |
3802 | out_unlock: |
3803 | btrfs_tree_unlock(right); | |
3804 | free_extent_buffer(right); | |
3805 | return 1; | |
3806 | } | |
3807 | ||
74123bd7 CM |
3808 | /* |
3809 | * push some data in the path leaf to the left, trying to free up at | |
3810 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
99d8f83c CM |
3811 | * |
3812 | * max_slot can put a limit on how far into the leaf we'll push items. The | |
3813 | * item at 'max_slot' won't be touched. Use (u32)-1 to make us do all the | |
3814 | * items | |
74123bd7 | 3815 | */ |
44871b1b CM |
3816 | static noinline int __push_leaf_left(struct btrfs_trans_handle *trans, |
3817 | struct btrfs_root *root, | |
3818 | struct btrfs_path *path, int data_size, | |
3819 | int empty, struct extent_buffer *left, | |
99d8f83c CM |
3820 | int free_space, u32 right_nritems, |
3821 | u32 max_slot) | |
be0e5c09 | 3822 | { |
5f39d397 CM |
3823 | struct btrfs_disk_key disk_key; |
3824 | struct extent_buffer *right = path->nodes[0]; | |
be0e5c09 | 3825 | int i; |
be0e5c09 CM |
3826 | int push_space = 0; |
3827 | int push_items = 0; | |
0783fcfc | 3828 | struct btrfs_item *item; |
7518a238 | 3829 | u32 old_left_nritems; |
34a38218 | 3830 | u32 nr; |
aa5d6bed | 3831 | int ret = 0; |
db94535d CM |
3832 | u32 this_item_size; |
3833 | u32 old_left_item_size; | |
cfed81a0 CM |
3834 | struct btrfs_map_token token; |
3835 | ||
3836 | btrfs_init_map_token(&token); | |
be0e5c09 | 3837 | |
34a38218 | 3838 | if (empty) |
99d8f83c | 3839 | nr = min(right_nritems, max_slot); |
34a38218 | 3840 | else |
99d8f83c | 3841 | nr = min(right_nritems - 1, max_slot); |
34a38218 CM |
3842 | |
3843 | for (i = 0; i < nr; i++) { | |
dd3cc16b | 3844 | item = btrfs_item_nr(i); |
db94535d | 3845 | |
31840ae1 ZY |
3846 | if (!empty && push_items > 0) { |
3847 | if (path->slots[0] < i) | |
3848 | break; | |
3849 | if (path->slots[0] == i) { | |
3850 | int space = btrfs_leaf_free_space(root, right); | |
3851 | if (space + push_space * 2 > free_space) | |
3852 | break; | |
3853 | } | |
3854 | } | |
3855 | ||
be0e5c09 | 3856 | if (path->slots[0] == i) |
87b29b20 | 3857 | push_space += data_size; |
db94535d CM |
3858 | |
3859 | this_item_size = btrfs_item_size(right, item); | |
3860 | if (this_item_size + sizeof(*item) + push_space > free_space) | |
be0e5c09 | 3861 | break; |
db94535d | 3862 | |
be0e5c09 | 3863 | push_items++; |
db94535d CM |
3864 | push_space += this_item_size + sizeof(*item); |
3865 | } | |
3866 | ||
be0e5c09 | 3867 | if (push_items == 0) { |
925baedd CM |
3868 | ret = 1; |
3869 | goto out; | |
be0e5c09 | 3870 | } |
fae7f21c | 3871 | WARN_ON(!empty && push_items == btrfs_header_nritems(right)); |
5f39d397 | 3872 | |
be0e5c09 | 3873 | /* push data from right to left */ |
5f39d397 CM |
3874 | copy_extent_buffer(left, right, |
3875 | btrfs_item_nr_offset(btrfs_header_nritems(left)), | |
3876 | btrfs_item_nr_offset(0), | |
3877 | push_items * sizeof(struct btrfs_item)); | |
3878 | ||
123abc88 | 3879 | push_space = BTRFS_LEAF_DATA_SIZE(root) - |
d397712b | 3880 | btrfs_item_offset_nr(right, push_items - 1); |
5f39d397 CM |
3881 | |
3882 | copy_extent_buffer(left, right, btrfs_leaf_data(left) + | |
d6025579 CM |
3883 | leaf_data_end(root, left) - push_space, |
3884 | btrfs_leaf_data(right) + | |
5f39d397 | 3885 | btrfs_item_offset_nr(right, push_items - 1), |
d6025579 | 3886 | push_space); |
5f39d397 | 3887 | old_left_nritems = btrfs_header_nritems(left); |
87b29b20 | 3888 | BUG_ON(old_left_nritems <= 0); |
eb60ceac | 3889 | |
db94535d | 3890 | old_left_item_size = btrfs_item_offset_nr(left, old_left_nritems - 1); |
0783fcfc | 3891 | for (i = old_left_nritems; i < old_left_nritems + push_items; i++) { |
5f39d397 | 3892 | u32 ioff; |
db94535d | 3893 | |
dd3cc16b | 3894 | item = btrfs_item_nr(i); |
db94535d | 3895 | |
cfed81a0 CM |
3896 | ioff = btrfs_token_item_offset(left, item, &token); |
3897 | btrfs_set_token_item_offset(left, item, | |
3898 | ioff - (BTRFS_LEAF_DATA_SIZE(root) - old_left_item_size), | |
3899 | &token); | |
be0e5c09 | 3900 | } |
5f39d397 | 3901 | btrfs_set_header_nritems(left, old_left_nritems + push_items); |
be0e5c09 CM |
3902 | |
3903 | /* fixup right node */ | |
31b1a2bd JL |
3904 | if (push_items > right_nritems) |
3905 | WARN(1, KERN_CRIT "push items %d nr %u\n", push_items, | |
d397712b | 3906 | right_nritems); |
34a38218 CM |
3907 | |
3908 | if (push_items < right_nritems) { | |
3909 | push_space = btrfs_item_offset_nr(right, push_items - 1) - | |
3910 | leaf_data_end(root, right); | |
3911 | memmove_extent_buffer(right, btrfs_leaf_data(right) + | |
3912 | BTRFS_LEAF_DATA_SIZE(root) - push_space, | |
3913 | btrfs_leaf_data(right) + | |
3914 | leaf_data_end(root, right), push_space); | |
3915 | ||
3916 | memmove_extent_buffer(right, btrfs_item_nr_offset(0), | |
5f39d397 CM |
3917 | btrfs_item_nr_offset(push_items), |
3918 | (btrfs_header_nritems(right) - push_items) * | |
3919 | sizeof(struct btrfs_item)); | |
34a38218 | 3920 | } |
eef1c494 Y |
3921 | right_nritems -= push_items; |
3922 | btrfs_set_header_nritems(right, right_nritems); | |
123abc88 | 3923 | push_space = BTRFS_LEAF_DATA_SIZE(root); |
5f39d397 | 3924 | for (i = 0; i < right_nritems; i++) { |
dd3cc16b | 3925 | item = btrfs_item_nr(i); |
db94535d | 3926 | |
cfed81a0 CM |
3927 | push_space = push_space - btrfs_token_item_size(right, |
3928 | item, &token); | |
3929 | btrfs_set_token_item_offset(right, item, push_space, &token); | |
db94535d | 3930 | } |
eb60ceac | 3931 | |
5f39d397 | 3932 | btrfs_mark_buffer_dirty(left); |
34a38218 CM |
3933 | if (right_nritems) |
3934 | btrfs_mark_buffer_dirty(right); | |
f0486c68 | 3935 | else |
01d58472 | 3936 | clean_tree_block(trans, root->fs_info, right); |
098f59c2 | 3937 | |
5f39d397 | 3938 | btrfs_item_key(right, &disk_key, 0); |
b7a0365e | 3939 | fixup_low_keys(root->fs_info, path, &disk_key, 1); |
be0e5c09 CM |
3940 | |
3941 | /* then fixup the leaf pointer in the path */ | |
3942 | if (path->slots[0] < push_items) { | |
3943 | path->slots[0] += old_left_nritems; | |
925baedd | 3944 | btrfs_tree_unlock(path->nodes[0]); |
5f39d397 CM |
3945 | free_extent_buffer(path->nodes[0]); |
3946 | path->nodes[0] = left; | |
be0e5c09 CM |
3947 | path->slots[1] -= 1; |
3948 | } else { | |
925baedd | 3949 | btrfs_tree_unlock(left); |
5f39d397 | 3950 | free_extent_buffer(left); |
be0e5c09 CM |
3951 | path->slots[0] -= push_items; |
3952 | } | |
eb60ceac | 3953 | BUG_ON(path->slots[0] < 0); |
aa5d6bed | 3954 | return ret; |
925baedd CM |
3955 | out: |
3956 | btrfs_tree_unlock(left); | |
3957 | free_extent_buffer(left); | |
3958 | return ret; | |
be0e5c09 CM |
3959 | } |
3960 | ||
44871b1b CM |
3961 | /* |
3962 | * push some data in the path leaf to the left, trying to free up at | |
3963 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
99d8f83c CM |
3964 | * |
3965 | * max_slot can put a limit on how far into the leaf we'll push items. The | |
3966 | * item at 'max_slot' won't be touched. Use (u32)-1 to make us push all the | |
3967 | * items | |
44871b1b CM |
3968 | */ |
3969 | static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root | |
99d8f83c CM |
3970 | *root, struct btrfs_path *path, int min_data_size, |
3971 | int data_size, int empty, u32 max_slot) | |
44871b1b CM |
3972 | { |
3973 | struct extent_buffer *right = path->nodes[0]; | |
3974 | struct extent_buffer *left; | |
3975 | int slot; | |
3976 | int free_space; | |
3977 | u32 right_nritems; | |
3978 | int ret = 0; | |
3979 | ||
3980 | slot = path->slots[1]; | |
3981 | if (slot == 0) | |
3982 | return 1; | |
3983 | if (!path->nodes[1]) | |
3984 | return 1; | |
3985 | ||
3986 | right_nritems = btrfs_header_nritems(right); | |
3987 | if (right_nritems == 0) | |
3988 | return 1; | |
3989 | ||
3990 | btrfs_assert_tree_locked(path->nodes[1]); | |
3991 | ||
3992 | left = read_node_slot(root, path->nodes[1], slot - 1); | |
91ca338d TI |
3993 | if (left == NULL) |
3994 | return 1; | |
3995 | ||
44871b1b CM |
3996 | btrfs_tree_lock(left); |
3997 | btrfs_set_lock_blocking(left); | |
3998 | ||
3999 | free_space = btrfs_leaf_free_space(root, left); | |
4000 | if (free_space < data_size) { | |
4001 | ret = 1; | |
4002 | goto out; | |
4003 | } | |
4004 | ||
4005 | /* cow and double check */ | |
4006 | ret = btrfs_cow_block(trans, root, left, | |
4007 | path->nodes[1], slot - 1, &left); | |
4008 | if (ret) { | |
4009 | /* we hit -ENOSPC, but it isn't fatal here */ | |
79787eaa JM |
4010 | if (ret == -ENOSPC) |
4011 | ret = 1; | |
44871b1b CM |
4012 | goto out; |
4013 | } | |
4014 | ||
4015 | free_space = btrfs_leaf_free_space(root, left); | |
4016 | if (free_space < data_size) { | |
4017 | ret = 1; | |
4018 | goto out; | |
4019 | } | |
4020 | ||
99d8f83c CM |
4021 | return __push_leaf_left(trans, root, path, min_data_size, |
4022 | empty, left, free_space, right_nritems, | |
4023 | max_slot); | |
44871b1b CM |
4024 | out: |
4025 | btrfs_tree_unlock(left); | |
4026 | free_extent_buffer(left); | |
4027 | return ret; | |
4028 | } | |
4029 | ||
4030 | /* | |
4031 | * split the path's leaf in two, making sure there is at least data_size | |
4032 | * available for the resulting leaf level of the path. | |
44871b1b | 4033 | */ |
143bede5 JM |
4034 | static noinline void copy_for_split(struct btrfs_trans_handle *trans, |
4035 | struct btrfs_root *root, | |
4036 | struct btrfs_path *path, | |
4037 | struct extent_buffer *l, | |
4038 | struct extent_buffer *right, | |
4039 | int slot, int mid, int nritems) | |
44871b1b CM |
4040 | { |
4041 | int data_copy_size; | |
4042 | int rt_data_off; | |
4043 | int i; | |
44871b1b | 4044 | struct btrfs_disk_key disk_key; |
cfed81a0 CM |
4045 | struct btrfs_map_token token; |
4046 | ||
4047 | btrfs_init_map_token(&token); | |
44871b1b CM |
4048 | |
4049 | nritems = nritems - mid; | |
4050 | btrfs_set_header_nritems(right, nritems); | |
4051 | data_copy_size = btrfs_item_end_nr(l, mid) - leaf_data_end(root, l); | |
4052 | ||
4053 | copy_extent_buffer(right, l, btrfs_item_nr_offset(0), | |
4054 | btrfs_item_nr_offset(mid), | |
4055 | nritems * sizeof(struct btrfs_item)); | |
4056 | ||
4057 | copy_extent_buffer(right, l, | |
4058 | btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) - | |
4059 | data_copy_size, btrfs_leaf_data(l) + | |
4060 | leaf_data_end(root, l), data_copy_size); | |
4061 | ||
4062 | rt_data_off = BTRFS_LEAF_DATA_SIZE(root) - | |
4063 | btrfs_item_end_nr(l, mid); | |
4064 | ||
4065 | for (i = 0; i < nritems; i++) { | |
dd3cc16b | 4066 | struct btrfs_item *item = btrfs_item_nr(i); |
44871b1b CM |
4067 | u32 ioff; |
4068 | ||
cfed81a0 CM |
4069 | ioff = btrfs_token_item_offset(right, item, &token); |
4070 | btrfs_set_token_item_offset(right, item, | |
4071 | ioff + rt_data_off, &token); | |
44871b1b CM |
4072 | } |
4073 | ||
44871b1b | 4074 | btrfs_set_header_nritems(l, mid); |
44871b1b | 4075 | btrfs_item_key(right, &disk_key, 0); |
143bede5 | 4076 | insert_ptr(trans, root, path, &disk_key, right->start, |
c3e06965 | 4077 | path->slots[1] + 1, 1); |
44871b1b CM |
4078 | |
4079 | btrfs_mark_buffer_dirty(right); | |
4080 | btrfs_mark_buffer_dirty(l); | |
4081 | BUG_ON(path->slots[0] != slot); | |
4082 | ||
44871b1b CM |
4083 | if (mid <= slot) { |
4084 | btrfs_tree_unlock(path->nodes[0]); | |
4085 | free_extent_buffer(path->nodes[0]); | |
4086 | path->nodes[0] = right; | |
4087 | path->slots[0] -= mid; | |
4088 | path->slots[1] += 1; | |
4089 | } else { | |
4090 | btrfs_tree_unlock(right); | |
4091 | free_extent_buffer(right); | |
4092 | } | |
4093 | ||
4094 | BUG_ON(path->slots[0] < 0); | |
44871b1b CM |
4095 | } |
4096 | ||
99d8f83c CM |
4097 | /* |
4098 | * double splits happen when we need to insert a big item in the middle | |
4099 | * of a leaf. A double split can leave us with 3 mostly empty leaves: | |
4100 | * leaf: [ slots 0 - N] [ our target ] [ N + 1 - total in leaf ] | |
4101 | * A B C | |
4102 | * | |
4103 | * We avoid this by trying to push the items on either side of our target | |
4104 | * into the adjacent leaves. If all goes well we can avoid the double split | |
4105 | * completely. | |
4106 | */ | |
4107 | static noinline int push_for_double_split(struct btrfs_trans_handle *trans, | |
4108 | struct btrfs_root *root, | |
4109 | struct btrfs_path *path, | |
4110 | int data_size) | |
4111 | { | |
4112 | int ret; | |
4113 | int progress = 0; | |
4114 | int slot; | |
4115 | u32 nritems; | |
5a4267ca | 4116 | int space_needed = data_size; |
99d8f83c CM |
4117 | |
4118 | slot = path->slots[0]; | |
5a4267ca FDBM |
4119 | if (slot < btrfs_header_nritems(path->nodes[0])) |
4120 | space_needed -= btrfs_leaf_free_space(root, path->nodes[0]); | |
99d8f83c CM |
4121 | |
4122 | /* | |
4123 | * try to push all the items after our slot into the | |
4124 | * right leaf | |
4125 | */ | |
5a4267ca | 4126 | ret = push_leaf_right(trans, root, path, 1, space_needed, 0, slot); |
99d8f83c CM |
4127 | if (ret < 0) |
4128 | return ret; | |
4129 | ||
4130 | if (ret == 0) | |
4131 | progress++; | |
4132 | ||
4133 | nritems = btrfs_header_nritems(path->nodes[0]); | |
4134 | /* | |
4135 | * our goal is to get our slot at the start or end of a leaf. If | |
4136 | * we've done so we're done | |
4137 | */ | |
4138 | if (path->slots[0] == 0 || path->slots[0] == nritems) | |
4139 | return 0; | |
4140 | ||
4141 | if (btrfs_leaf_free_space(root, path->nodes[0]) >= data_size) | |
4142 | return 0; | |
4143 | ||
4144 | /* try to push all the items before our slot into the next leaf */ | |
4145 | slot = path->slots[0]; | |
5a4267ca | 4146 | ret = push_leaf_left(trans, root, path, 1, space_needed, 0, slot); |
99d8f83c CM |
4147 | if (ret < 0) |
4148 | return ret; | |
4149 | ||
4150 | if (ret == 0) | |
4151 | progress++; | |
4152 | ||
4153 | if (progress) | |
4154 | return 0; | |
4155 | return 1; | |
4156 | } | |
4157 | ||
74123bd7 CM |
4158 | /* |
4159 | * split the path's leaf in two, making sure there is at least data_size | |
4160 | * available for the resulting leaf level of the path. | |
aa5d6bed CM |
4161 | * |
4162 | * returns 0 if all went well and < 0 on failure. | |
74123bd7 | 4163 | */ |
e02119d5 CM |
4164 | static noinline int split_leaf(struct btrfs_trans_handle *trans, |
4165 | struct btrfs_root *root, | |
4166 | struct btrfs_key *ins_key, | |
4167 | struct btrfs_path *path, int data_size, | |
4168 | int extend) | |
be0e5c09 | 4169 | { |
5d4f98a2 | 4170 | struct btrfs_disk_key disk_key; |
5f39d397 | 4171 | struct extent_buffer *l; |
7518a238 | 4172 | u32 nritems; |
eb60ceac CM |
4173 | int mid; |
4174 | int slot; | |
5f39d397 | 4175 | struct extent_buffer *right; |
b7a0365e | 4176 | struct btrfs_fs_info *fs_info = root->fs_info; |
d4dbff95 | 4177 | int ret = 0; |
aa5d6bed | 4178 | int wret; |
5d4f98a2 | 4179 | int split; |
cc0c5538 | 4180 | int num_doubles = 0; |
99d8f83c | 4181 | int tried_avoid_double = 0; |
aa5d6bed | 4182 | |
a5719521 YZ |
4183 | l = path->nodes[0]; |
4184 | slot = path->slots[0]; | |
4185 | if (extend && data_size + btrfs_item_size_nr(l, slot) + | |
4186 | sizeof(struct btrfs_item) > BTRFS_LEAF_DATA_SIZE(root)) | |
4187 | return -EOVERFLOW; | |
4188 | ||
40689478 | 4189 | /* first try to make some room by pushing left and right */ |
33157e05 | 4190 | if (data_size && path->nodes[1]) { |
5a4267ca FDBM |
4191 | int space_needed = data_size; |
4192 | ||
4193 | if (slot < btrfs_header_nritems(l)) | |
4194 | space_needed -= btrfs_leaf_free_space(root, l); | |
4195 | ||
4196 | wret = push_leaf_right(trans, root, path, space_needed, | |
4197 | space_needed, 0, 0); | |
d397712b | 4198 | if (wret < 0) |
eaee50e8 | 4199 | return wret; |
3685f791 | 4200 | if (wret) { |
5a4267ca FDBM |
4201 | wret = push_leaf_left(trans, root, path, space_needed, |
4202 | space_needed, 0, (u32)-1); | |
3685f791 CM |
4203 | if (wret < 0) |
4204 | return wret; | |
4205 | } | |
4206 | l = path->nodes[0]; | |
aa5d6bed | 4207 | |
3685f791 | 4208 | /* did the pushes work? */ |
87b29b20 | 4209 | if (btrfs_leaf_free_space(root, l) >= data_size) |
3685f791 | 4210 | return 0; |
3326d1b0 | 4211 | } |
aa5d6bed | 4212 | |
5c680ed6 | 4213 | if (!path->nodes[1]) { |
fdd99c72 | 4214 | ret = insert_new_root(trans, root, path, 1); |
5c680ed6 CM |
4215 | if (ret) |
4216 | return ret; | |
4217 | } | |
cc0c5538 | 4218 | again: |
5d4f98a2 | 4219 | split = 1; |
cc0c5538 | 4220 | l = path->nodes[0]; |
eb60ceac | 4221 | slot = path->slots[0]; |
5f39d397 | 4222 | nritems = btrfs_header_nritems(l); |
d397712b | 4223 | mid = (nritems + 1) / 2; |
54aa1f4d | 4224 | |
5d4f98a2 YZ |
4225 | if (mid <= slot) { |
4226 | if (nritems == 1 || | |
4227 | leaf_space_used(l, mid, nritems - mid) + data_size > | |
4228 | BTRFS_LEAF_DATA_SIZE(root)) { | |
4229 | if (slot >= nritems) { | |
4230 | split = 0; | |
4231 | } else { | |
4232 | mid = slot; | |
4233 | if (mid != nritems && | |
4234 | leaf_space_used(l, mid, nritems - mid) + | |
4235 | data_size > BTRFS_LEAF_DATA_SIZE(root)) { | |
99d8f83c CM |
4236 | if (data_size && !tried_avoid_double) |
4237 | goto push_for_double; | |
5d4f98a2 YZ |
4238 | split = 2; |
4239 | } | |
4240 | } | |
4241 | } | |
4242 | } else { | |
4243 | if (leaf_space_used(l, 0, mid) + data_size > | |
4244 | BTRFS_LEAF_DATA_SIZE(root)) { | |
4245 | if (!extend && data_size && slot == 0) { | |
4246 | split = 0; | |
4247 | } else if ((extend || !data_size) && slot == 0) { | |
4248 | mid = 1; | |
4249 | } else { | |
4250 | mid = slot; | |
4251 | if (mid != nritems && | |
4252 | leaf_space_used(l, mid, nritems - mid) + | |
4253 | data_size > BTRFS_LEAF_DATA_SIZE(root)) { | |
99d8f83c CM |
4254 | if (data_size && !tried_avoid_double) |
4255 | goto push_for_double; | |
67871254 | 4256 | split = 2; |
5d4f98a2 YZ |
4257 | } |
4258 | } | |
4259 | } | |
4260 | } | |
4261 | ||
4262 | if (split == 0) | |
4263 | btrfs_cpu_key_to_disk(&disk_key, ins_key); | |
4264 | else | |
4265 | btrfs_item_key(l, &disk_key, mid); | |
4266 | ||
4d75f8a9 DS |
4267 | right = btrfs_alloc_tree_block(trans, root, 0, root->root_key.objectid, |
4268 | &disk_key, 0, l->start, 0); | |
f0486c68 | 4269 | if (IS_ERR(right)) |
5f39d397 | 4270 | return PTR_ERR(right); |
f0486c68 | 4271 | |
707e8a07 | 4272 | root_add_used(root, root->nodesize); |
5f39d397 CM |
4273 | |
4274 | memset_extent_buffer(right, 0, 0, sizeof(struct btrfs_header)); | |
db94535d | 4275 | btrfs_set_header_bytenr(right, right->start); |
5f39d397 | 4276 | btrfs_set_header_generation(right, trans->transid); |
5d4f98a2 | 4277 | btrfs_set_header_backref_rev(right, BTRFS_MIXED_BACKREF_REV); |
5f39d397 CM |
4278 | btrfs_set_header_owner(right, root->root_key.objectid); |
4279 | btrfs_set_header_level(right, 0); | |
b7a0365e | 4280 | write_extent_buffer(right, fs_info->fsid, |
0a4e5586 | 4281 | btrfs_header_fsid(), BTRFS_FSID_SIZE); |
e17cade2 | 4282 | |
b7a0365e | 4283 | write_extent_buffer(right, fs_info->chunk_tree_uuid, |
b308bc2f | 4284 | btrfs_header_chunk_tree_uuid(right), |
e17cade2 | 4285 | BTRFS_UUID_SIZE); |
44871b1b | 4286 | |
5d4f98a2 YZ |
4287 | if (split == 0) { |
4288 | if (mid <= slot) { | |
4289 | btrfs_set_header_nritems(right, 0); | |
143bede5 | 4290 | insert_ptr(trans, root, path, &disk_key, right->start, |
c3e06965 | 4291 | path->slots[1] + 1, 1); |
5d4f98a2 YZ |
4292 | btrfs_tree_unlock(path->nodes[0]); |
4293 | free_extent_buffer(path->nodes[0]); | |
4294 | path->nodes[0] = right; | |
4295 | path->slots[0] = 0; | |
4296 | path->slots[1] += 1; | |
4297 | } else { | |
4298 | btrfs_set_header_nritems(right, 0); | |
143bede5 | 4299 | insert_ptr(trans, root, path, &disk_key, right->start, |
c3e06965 | 4300 | path->slots[1], 1); |
5d4f98a2 YZ |
4301 | btrfs_tree_unlock(path->nodes[0]); |
4302 | free_extent_buffer(path->nodes[0]); | |
4303 | path->nodes[0] = right; | |
4304 | path->slots[0] = 0; | |
143bede5 | 4305 | if (path->slots[1] == 0) |
b7a0365e | 4306 | fixup_low_keys(fs_info, path, &disk_key, 1); |
d4dbff95 | 4307 | } |
5d4f98a2 YZ |
4308 | btrfs_mark_buffer_dirty(right); |
4309 | return ret; | |
d4dbff95 | 4310 | } |
74123bd7 | 4311 | |
143bede5 | 4312 | copy_for_split(trans, root, path, l, right, slot, mid, nritems); |
31840ae1 | 4313 | |
5d4f98a2 | 4314 | if (split == 2) { |
cc0c5538 CM |
4315 | BUG_ON(num_doubles != 0); |
4316 | num_doubles++; | |
4317 | goto again; | |
a429e513 | 4318 | } |
44871b1b | 4319 | |
143bede5 | 4320 | return 0; |
99d8f83c CM |
4321 | |
4322 | push_for_double: | |
4323 | push_for_double_split(trans, root, path, data_size); | |
4324 | tried_avoid_double = 1; | |
4325 | if (btrfs_leaf_free_space(root, path->nodes[0]) >= data_size) | |
4326 | return 0; | |
4327 | goto again; | |
be0e5c09 CM |
4328 | } |
4329 | ||
ad48fd75 YZ |
4330 | static noinline int setup_leaf_for_split(struct btrfs_trans_handle *trans, |
4331 | struct btrfs_root *root, | |
4332 | struct btrfs_path *path, int ins_len) | |
459931ec | 4333 | { |
ad48fd75 | 4334 | struct btrfs_key key; |
459931ec | 4335 | struct extent_buffer *leaf; |
ad48fd75 YZ |
4336 | struct btrfs_file_extent_item *fi; |
4337 | u64 extent_len = 0; | |
4338 | u32 item_size; | |
4339 | int ret; | |
459931ec CM |
4340 | |
4341 | leaf = path->nodes[0]; | |
ad48fd75 YZ |
4342 | btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
4343 | ||
4344 | BUG_ON(key.type != BTRFS_EXTENT_DATA_KEY && | |
4345 | key.type != BTRFS_EXTENT_CSUM_KEY); | |
4346 | ||
4347 | if (btrfs_leaf_free_space(root, leaf) >= ins_len) | |
4348 | return 0; | |
459931ec CM |
4349 | |
4350 | item_size = btrfs_item_size_nr(leaf, path->slots[0]); | |
ad48fd75 YZ |
4351 | if (key.type == BTRFS_EXTENT_DATA_KEY) { |
4352 | fi = btrfs_item_ptr(leaf, path->slots[0], | |
4353 | struct btrfs_file_extent_item); | |
4354 | extent_len = btrfs_file_extent_num_bytes(leaf, fi); | |
4355 | } | |
b3b4aa74 | 4356 | btrfs_release_path(path); |
459931ec | 4357 | |
459931ec | 4358 | path->keep_locks = 1; |
ad48fd75 YZ |
4359 | path->search_for_split = 1; |
4360 | ret = btrfs_search_slot(trans, root, &key, path, 0, 1); | |
459931ec | 4361 | path->search_for_split = 0; |
a8df6fe6 FM |
4362 | if (ret > 0) |
4363 | ret = -EAGAIN; | |
ad48fd75 YZ |
4364 | if (ret < 0) |
4365 | goto err; | |
459931ec | 4366 | |
ad48fd75 YZ |
4367 | ret = -EAGAIN; |
4368 | leaf = path->nodes[0]; | |
a8df6fe6 FM |
4369 | /* if our item isn't there, return now */ |
4370 | if (item_size != btrfs_item_size_nr(leaf, path->slots[0])) | |
ad48fd75 YZ |
4371 | goto err; |
4372 | ||
109f6aef CM |
4373 | /* the leaf has changed, it now has room. return now */ |
4374 | if (btrfs_leaf_free_space(root, path->nodes[0]) >= ins_len) | |
4375 | goto err; | |
4376 | ||
ad48fd75 YZ |
4377 | if (key.type == BTRFS_EXTENT_DATA_KEY) { |
4378 | fi = btrfs_item_ptr(leaf, path->slots[0], | |
4379 | struct btrfs_file_extent_item); | |
4380 | if (extent_len != btrfs_file_extent_num_bytes(leaf, fi)) | |
4381 | goto err; | |
459931ec CM |
4382 | } |
4383 | ||
b9473439 | 4384 | btrfs_set_path_blocking(path); |
ad48fd75 | 4385 | ret = split_leaf(trans, root, &key, path, ins_len, 1); |
f0486c68 YZ |
4386 | if (ret) |
4387 | goto err; | |
459931ec | 4388 | |
ad48fd75 | 4389 | path->keep_locks = 0; |
b9473439 | 4390 | btrfs_unlock_up_safe(path, 1); |
ad48fd75 YZ |
4391 | return 0; |
4392 | err: | |
4393 | path->keep_locks = 0; | |
4394 | return ret; | |
4395 | } | |
4396 | ||
4397 | static noinline int split_item(struct btrfs_trans_handle *trans, | |
4398 | struct btrfs_root *root, | |
4399 | struct btrfs_path *path, | |
4400 | struct btrfs_key *new_key, | |
4401 | unsigned long split_offset) | |
4402 | { | |
4403 | struct extent_buffer *leaf; | |
4404 | struct btrfs_item *item; | |
4405 | struct btrfs_item *new_item; | |
4406 | int slot; | |
4407 | char *buf; | |
4408 | u32 nritems; | |
4409 | u32 item_size; | |
4410 | u32 orig_offset; | |
4411 | struct btrfs_disk_key disk_key; | |
4412 | ||
b9473439 CM |
4413 | leaf = path->nodes[0]; |
4414 | BUG_ON(btrfs_leaf_free_space(root, leaf) < sizeof(struct btrfs_item)); | |
4415 | ||
b4ce94de CM |
4416 | btrfs_set_path_blocking(path); |
4417 | ||
dd3cc16b | 4418 | item = btrfs_item_nr(path->slots[0]); |
459931ec CM |
4419 | orig_offset = btrfs_item_offset(leaf, item); |
4420 | item_size = btrfs_item_size(leaf, item); | |
4421 | ||
459931ec | 4422 | buf = kmalloc(item_size, GFP_NOFS); |
ad48fd75 YZ |
4423 | if (!buf) |
4424 | return -ENOMEM; | |
4425 | ||
459931ec CM |
4426 | read_extent_buffer(leaf, buf, btrfs_item_ptr_offset(leaf, |
4427 | path->slots[0]), item_size); | |
459931ec | 4428 | |
ad48fd75 | 4429 | slot = path->slots[0] + 1; |
459931ec | 4430 | nritems = btrfs_header_nritems(leaf); |
459931ec CM |
4431 | if (slot != nritems) { |
4432 | /* shift the items */ | |
4433 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + 1), | |
ad48fd75 YZ |
4434 | btrfs_item_nr_offset(slot), |
4435 | (nritems - slot) * sizeof(struct btrfs_item)); | |
459931ec CM |
4436 | } |
4437 | ||
4438 | btrfs_cpu_key_to_disk(&disk_key, new_key); | |
4439 | btrfs_set_item_key(leaf, &disk_key, slot); | |
4440 | ||
dd3cc16b | 4441 | new_item = btrfs_item_nr(slot); |
459931ec CM |
4442 | |
4443 | btrfs_set_item_offset(leaf, new_item, orig_offset); | |
4444 | btrfs_set_item_size(leaf, new_item, item_size - split_offset); | |
4445 | ||
4446 | btrfs_set_item_offset(leaf, item, | |
4447 | orig_offset + item_size - split_offset); | |
4448 | btrfs_set_item_size(leaf, item, split_offset); | |
4449 | ||
4450 | btrfs_set_header_nritems(leaf, nritems + 1); | |
4451 | ||
4452 | /* write the data for the start of the original item */ | |
4453 | write_extent_buffer(leaf, buf, | |
4454 | btrfs_item_ptr_offset(leaf, path->slots[0]), | |
4455 | split_offset); | |
4456 | ||
4457 | /* write the data for the new item */ | |
4458 | write_extent_buffer(leaf, buf + split_offset, | |
4459 | btrfs_item_ptr_offset(leaf, slot), | |
4460 | item_size - split_offset); | |
4461 | btrfs_mark_buffer_dirty(leaf); | |
4462 | ||
ad48fd75 | 4463 | BUG_ON(btrfs_leaf_free_space(root, leaf) < 0); |
459931ec | 4464 | kfree(buf); |
ad48fd75 YZ |
4465 | return 0; |
4466 | } | |
4467 | ||
4468 | /* | |
4469 | * This function splits a single item into two items, | |
4470 | * giving 'new_key' to the new item and splitting the | |
4471 | * old one at split_offset (from the start of the item). | |
4472 | * | |
4473 | * The path may be released by this operation. After | |
4474 | * the split, the path is pointing to the old item. The | |
4475 | * new item is going to be in the same node as the old one. | |
4476 | * | |
4477 | * Note, the item being split must be smaller enough to live alone on | |
4478 | * a tree block with room for one extra struct btrfs_item | |
4479 | * | |
4480 | * This allows us to split the item in place, keeping a lock on the | |
4481 | * leaf the entire time. | |
4482 | */ | |
4483 | int btrfs_split_item(struct btrfs_trans_handle *trans, | |
4484 | struct btrfs_root *root, | |
4485 | struct btrfs_path *path, | |
4486 | struct btrfs_key *new_key, | |
4487 | unsigned long split_offset) | |
4488 | { | |
4489 | int ret; | |
4490 | ret = setup_leaf_for_split(trans, root, path, | |
4491 | sizeof(struct btrfs_item)); | |
4492 | if (ret) | |
4493 | return ret; | |
4494 | ||
4495 | ret = split_item(trans, root, path, new_key, split_offset); | |
459931ec CM |
4496 | return ret; |
4497 | } | |
4498 | ||
ad48fd75 YZ |
4499 | /* |
4500 | * This function duplicate a item, giving 'new_key' to the new item. | |
4501 | * It guarantees both items live in the same tree leaf and the new item | |
4502 | * is contiguous with the original item. | |
4503 | * | |
4504 | * This allows us to split file extent in place, keeping a lock on the | |
4505 | * leaf the entire time. | |
4506 | */ | |
4507 | int btrfs_duplicate_item(struct btrfs_trans_handle *trans, | |
4508 | struct btrfs_root *root, | |
4509 | struct btrfs_path *path, | |
4510 | struct btrfs_key *new_key) | |
4511 | { | |
4512 | struct extent_buffer *leaf; | |
4513 | int ret; | |
4514 | u32 item_size; | |
4515 | ||
4516 | leaf = path->nodes[0]; | |
4517 | item_size = btrfs_item_size_nr(leaf, path->slots[0]); | |
4518 | ret = setup_leaf_for_split(trans, root, path, | |
4519 | item_size + sizeof(struct btrfs_item)); | |
4520 | if (ret) | |
4521 | return ret; | |
4522 | ||
4523 | path->slots[0]++; | |
afe5fea7 | 4524 | setup_items_for_insert(root, path, new_key, &item_size, |
143bede5 JM |
4525 | item_size, item_size + |
4526 | sizeof(struct btrfs_item), 1); | |
ad48fd75 YZ |
4527 | leaf = path->nodes[0]; |
4528 | memcpy_extent_buffer(leaf, | |
4529 | btrfs_item_ptr_offset(leaf, path->slots[0]), | |
4530 | btrfs_item_ptr_offset(leaf, path->slots[0] - 1), | |
4531 | item_size); | |
4532 | return 0; | |
4533 | } | |
4534 | ||
d352ac68 CM |
4535 | /* |
4536 | * make the item pointed to by the path smaller. new_size indicates | |
4537 | * how small to make it, and from_end tells us if we just chop bytes | |
4538 | * off the end of the item or if we shift the item to chop bytes off | |
4539 | * the front. | |
4540 | */ | |
afe5fea7 | 4541 | void btrfs_truncate_item(struct btrfs_root *root, struct btrfs_path *path, |
143bede5 | 4542 | u32 new_size, int from_end) |
b18c6685 | 4543 | { |
b18c6685 | 4544 | int slot; |
5f39d397 CM |
4545 | struct extent_buffer *leaf; |
4546 | struct btrfs_item *item; | |
b18c6685 CM |
4547 | u32 nritems; |
4548 | unsigned int data_end; | |
4549 | unsigned int old_data_start; | |
4550 | unsigned int old_size; | |
4551 | unsigned int size_diff; | |
4552 | int i; | |
cfed81a0 CM |
4553 | struct btrfs_map_token token; |
4554 | ||
4555 | btrfs_init_map_token(&token); | |
b18c6685 | 4556 | |
5f39d397 | 4557 | leaf = path->nodes[0]; |
179e29e4 CM |
4558 | slot = path->slots[0]; |
4559 | ||
4560 | old_size = btrfs_item_size_nr(leaf, slot); | |
4561 | if (old_size == new_size) | |
143bede5 | 4562 | return; |
b18c6685 | 4563 | |
5f39d397 | 4564 | nritems = btrfs_header_nritems(leaf); |
b18c6685 CM |
4565 | data_end = leaf_data_end(root, leaf); |
4566 | ||
5f39d397 | 4567 | old_data_start = btrfs_item_offset_nr(leaf, slot); |
179e29e4 | 4568 | |
b18c6685 CM |
4569 | size_diff = old_size - new_size; |
4570 | ||
4571 | BUG_ON(slot < 0); | |
4572 | BUG_ON(slot >= nritems); | |
4573 | ||
4574 | /* | |
4575 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
4576 | */ | |
4577 | /* first correct the data pointers */ | |
4578 | for (i = slot; i < nritems; i++) { | |
5f39d397 | 4579 | u32 ioff; |
dd3cc16b | 4580 | item = btrfs_item_nr(i); |
db94535d | 4581 | |
cfed81a0 CM |
4582 | ioff = btrfs_token_item_offset(leaf, item, &token); |
4583 | btrfs_set_token_item_offset(leaf, item, | |
4584 | ioff + size_diff, &token); | |
b18c6685 | 4585 | } |
db94535d | 4586 | |
b18c6685 | 4587 | /* shift the data */ |
179e29e4 CM |
4588 | if (from_end) { |
4589 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + | |
4590 | data_end + size_diff, btrfs_leaf_data(leaf) + | |
4591 | data_end, old_data_start + new_size - data_end); | |
4592 | } else { | |
4593 | struct btrfs_disk_key disk_key; | |
4594 | u64 offset; | |
4595 | ||
4596 | btrfs_item_key(leaf, &disk_key, slot); | |
4597 | ||
4598 | if (btrfs_disk_key_type(&disk_key) == BTRFS_EXTENT_DATA_KEY) { | |
4599 | unsigned long ptr; | |
4600 | struct btrfs_file_extent_item *fi; | |
4601 | ||
4602 | fi = btrfs_item_ptr(leaf, slot, | |
4603 | struct btrfs_file_extent_item); | |
4604 | fi = (struct btrfs_file_extent_item *)( | |
4605 | (unsigned long)fi - size_diff); | |
4606 | ||
4607 | if (btrfs_file_extent_type(leaf, fi) == | |
4608 | BTRFS_FILE_EXTENT_INLINE) { | |
4609 | ptr = btrfs_item_ptr_offset(leaf, slot); | |
4610 | memmove_extent_buffer(leaf, ptr, | |
d397712b | 4611 | (unsigned long)fi, |
7ec20afb | 4612 | BTRFS_FILE_EXTENT_INLINE_DATA_START); |
179e29e4 CM |
4613 | } |
4614 | } | |
4615 | ||
4616 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + | |
4617 | data_end + size_diff, btrfs_leaf_data(leaf) + | |
4618 | data_end, old_data_start - data_end); | |
4619 | ||
4620 | offset = btrfs_disk_key_offset(&disk_key); | |
4621 | btrfs_set_disk_key_offset(&disk_key, offset + size_diff); | |
4622 | btrfs_set_item_key(leaf, &disk_key, slot); | |
4623 | if (slot == 0) | |
b7a0365e | 4624 | fixup_low_keys(root->fs_info, path, &disk_key, 1); |
179e29e4 | 4625 | } |
5f39d397 | 4626 | |
dd3cc16b | 4627 | item = btrfs_item_nr(slot); |
5f39d397 CM |
4628 | btrfs_set_item_size(leaf, item, new_size); |
4629 | btrfs_mark_buffer_dirty(leaf); | |
b18c6685 | 4630 | |
5f39d397 CM |
4631 | if (btrfs_leaf_free_space(root, leaf) < 0) { |
4632 | btrfs_print_leaf(root, leaf); | |
b18c6685 | 4633 | BUG(); |
5f39d397 | 4634 | } |
b18c6685 CM |
4635 | } |
4636 | ||
d352ac68 | 4637 | /* |
8f69dbd2 | 4638 | * make the item pointed to by the path bigger, data_size is the added size. |
d352ac68 | 4639 | */ |
4b90c680 | 4640 | void btrfs_extend_item(struct btrfs_root *root, struct btrfs_path *path, |
143bede5 | 4641 | u32 data_size) |
6567e837 | 4642 | { |
6567e837 | 4643 | int slot; |
5f39d397 CM |
4644 | struct extent_buffer *leaf; |
4645 | struct btrfs_item *item; | |
6567e837 CM |
4646 | u32 nritems; |
4647 | unsigned int data_end; | |
4648 | unsigned int old_data; | |
4649 | unsigned int old_size; | |
4650 | int i; | |
cfed81a0 CM |
4651 | struct btrfs_map_token token; |
4652 | ||
4653 | btrfs_init_map_token(&token); | |
6567e837 | 4654 | |
5f39d397 | 4655 | leaf = path->nodes[0]; |
6567e837 | 4656 | |
5f39d397 | 4657 | nritems = btrfs_header_nritems(leaf); |
6567e837 CM |
4658 | data_end = leaf_data_end(root, leaf); |
4659 | ||
5f39d397 CM |
4660 | if (btrfs_leaf_free_space(root, leaf) < data_size) { |
4661 | btrfs_print_leaf(root, leaf); | |
6567e837 | 4662 | BUG(); |
5f39d397 | 4663 | } |
6567e837 | 4664 | slot = path->slots[0]; |
5f39d397 | 4665 | old_data = btrfs_item_end_nr(leaf, slot); |
6567e837 CM |
4666 | |
4667 | BUG_ON(slot < 0); | |
3326d1b0 CM |
4668 | if (slot >= nritems) { |
4669 | btrfs_print_leaf(root, leaf); | |
efe120a0 | 4670 | btrfs_crit(root->fs_info, "slot %d too large, nritems %d", |
d397712b | 4671 | slot, nritems); |
3326d1b0 CM |
4672 | BUG_ON(1); |
4673 | } | |
6567e837 CM |
4674 | |
4675 | /* | |
4676 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
4677 | */ | |
4678 | /* first correct the data pointers */ | |
4679 | for (i = slot; i < nritems; i++) { | |
5f39d397 | 4680 | u32 ioff; |
dd3cc16b | 4681 | item = btrfs_item_nr(i); |
db94535d | 4682 | |
cfed81a0 CM |
4683 | ioff = btrfs_token_item_offset(leaf, item, &token); |
4684 | btrfs_set_token_item_offset(leaf, item, | |
4685 | ioff - data_size, &token); | |
6567e837 | 4686 | } |
5f39d397 | 4687 | |
6567e837 | 4688 | /* shift the data */ |
5f39d397 | 4689 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + |
6567e837 CM |
4690 | data_end - data_size, btrfs_leaf_data(leaf) + |
4691 | data_end, old_data - data_end); | |
5f39d397 | 4692 | |
6567e837 | 4693 | data_end = old_data; |
5f39d397 | 4694 | old_size = btrfs_item_size_nr(leaf, slot); |
dd3cc16b | 4695 | item = btrfs_item_nr(slot); |
5f39d397 CM |
4696 | btrfs_set_item_size(leaf, item, old_size + data_size); |
4697 | btrfs_mark_buffer_dirty(leaf); | |
6567e837 | 4698 | |
5f39d397 CM |
4699 | if (btrfs_leaf_free_space(root, leaf) < 0) { |
4700 | btrfs_print_leaf(root, leaf); | |
6567e837 | 4701 | BUG(); |
5f39d397 | 4702 | } |
6567e837 CM |
4703 | } |
4704 | ||
74123bd7 | 4705 | /* |
44871b1b CM |
4706 | * this is a helper for btrfs_insert_empty_items, the main goal here is |
4707 | * to save stack depth by doing the bulk of the work in a function | |
4708 | * that doesn't call btrfs_search_slot | |
74123bd7 | 4709 | */ |
afe5fea7 | 4710 | void setup_items_for_insert(struct btrfs_root *root, struct btrfs_path *path, |
143bede5 JM |
4711 | struct btrfs_key *cpu_key, u32 *data_size, |
4712 | u32 total_data, u32 total_size, int nr) | |
be0e5c09 | 4713 | { |
5f39d397 | 4714 | struct btrfs_item *item; |
9c58309d | 4715 | int i; |
7518a238 | 4716 | u32 nritems; |
be0e5c09 | 4717 | unsigned int data_end; |
e2fa7227 | 4718 | struct btrfs_disk_key disk_key; |
44871b1b CM |
4719 | struct extent_buffer *leaf; |
4720 | int slot; | |
cfed81a0 CM |
4721 | struct btrfs_map_token token; |
4722 | ||
24cdc847 FM |
4723 | if (path->slots[0] == 0) { |
4724 | btrfs_cpu_key_to_disk(&disk_key, cpu_key); | |
b7a0365e | 4725 | fixup_low_keys(root->fs_info, path, &disk_key, 1); |
24cdc847 FM |
4726 | } |
4727 | btrfs_unlock_up_safe(path, 1); | |
4728 | ||
cfed81a0 | 4729 | btrfs_init_map_token(&token); |
e2fa7227 | 4730 | |
5f39d397 | 4731 | leaf = path->nodes[0]; |
44871b1b | 4732 | slot = path->slots[0]; |
74123bd7 | 4733 | |
5f39d397 | 4734 | nritems = btrfs_header_nritems(leaf); |
123abc88 | 4735 | data_end = leaf_data_end(root, leaf); |
eb60ceac | 4736 | |
f25956cc | 4737 | if (btrfs_leaf_free_space(root, leaf) < total_size) { |
3326d1b0 | 4738 | btrfs_print_leaf(root, leaf); |
efe120a0 | 4739 | btrfs_crit(root->fs_info, "not enough freespace need %u have %d", |
9c58309d | 4740 | total_size, btrfs_leaf_free_space(root, leaf)); |
be0e5c09 | 4741 | BUG(); |
d4dbff95 | 4742 | } |
5f39d397 | 4743 | |
be0e5c09 | 4744 | if (slot != nritems) { |
5f39d397 | 4745 | unsigned int old_data = btrfs_item_end_nr(leaf, slot); |
be0e5c09 | 4746 | |
5f39d397 CM |
4747 | if (old_data < data_end) { |
4748 | btrfs_print_leaf(root, leaf); | |
efe120a0 | 4749 | btrfs_crit(root->fs_info, "slot %d old_data %d data_end %d", |
5f39d397 CM |
4750 | slot, old_data, data_end); |
4751 | BUG_ON(1); | |
4752 | } | |
be0e5c09 CM |
4753 | /* |
4754 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
4755 | */ | |
4756 | /* first correct the data pointers */ | |
0783fcfc | 4757 | for (i = slot; i < nritems; i++) { |
5f39d397 | 4758 | u32 ioff; |
db94535d | 4759 | |
dd3cc16b | 4760 | item = btrfs_item_nr( i); |
cfed81a0 CM |
4761 | ioff = btrfs_token_item_offset(leaf, item, &token); |
4762 | btrfs_set_token_item_offset(leaf, item, | |
4763 | ioff - total_data, &token); | |
0783fcfc | 4764 | } |
be0e5c09 | 4765 | /* shift the items */ |
9c58309d | 4766 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr), |
5f39d397 | 4767 | btrfs_item_nr_offset(slot), |
d6025579 | 4768 | (nritems - slot) * sizeof(struct btrfs_item)); |
be0e5c09 CM |
4769 | |
4770 | /* shift the data */ | |
5f39d397 | 4771 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + |
9c58309d | 4772 | data_end - total_data, btrfs_leaf_data(leaf) + |
d6025579 | 4773 | data_end, old_data - data_end); |
be0e5c09 CM |
4774 | data_end = old_data; |
4775 | } | |
5f39d397 | 4776 | |
62e2749e | 4777 | /* setup the item for the new data */ |
9c58309d CM |
4778 | for (i = 0; i < nr; i++) { |
4779 | btrfs_cpu_key_to_disk(&disk_key, cpu_key + i); | |
4780 | btrfs_set_item_key(leaf, &disk_key, slot + i); | |
dd3cc16b | 4781 | item = btrfs_item_nr(slot + i); |
cfed81a0 CM |
4782 | btrfs_set_token_item_offset(leaf, item, |
4783 | data_end - data_size[i], &token); | |
9c58309d | 4784 | data_end -= data_size[i]; |
cfed81a0 | 4785 | btrfs_set_token_item_size(leaf, item, data_size[i], &token); |
9c58309d | 4786 | } |
44871b1b | 4787 | |
9c58309d | 4788 | btrfs_set_header_nritems(leaf, nritems + nr); |
b9473439 | 4789 | btrfs_mark_buffer_dirty(leaf); |
aa5d6bed | 4790 | |
5f39d397 CM |
4791 | if (btrfs_leaf_free_space(root, leaf) < 0) { |
4792 | btrfs_print_leaf(root, leaf); | |
be0e5c09 | 4793 | BUG(); |
5f39d397 | 4794 | } |
44871b1b CM |
4795 | } |
4796 | ||
4797 | /* | |
4798 | * Given a key and some data, insert items into the tree. | |
4799 | * This does all the path init required, making room in the tree if needed. | |
4800 | */ | |
4801 | int btrfs_insert_empty_items(struct btrfs_trans_handle *trans, | |
4802 | struct btrfs_root *root, | |
4803 | struct btrfs_path *path, | |
4804 | struct btrfs_key *cpu_key, u32 *data_size, | |
4805 | int nr) | |
4806 | { | |
44871b1b CM |
4807 | int ret = 0; |
4808 | int slot; | |
4809 | int i; | |
4810 | u32 total_size = 0; | |
4811 | u32 total_data = 0; | |
4812 | ||
4813 | for (i = 0; i < nr; i++) | |
4814 | total_data += data_size[i]; | |
4815 | ||
4816 | total_size = total_data + (nr * sizeof(struct btrfs_item)); | |
4817 | ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1); | |
4818 | if (ret == 0) | |
4819 | return -EEXIST; | |
4820 | if (ret < 0) | |
143bede5 | 4821 | return ret; |
44871b1b | 4822 | |
44871b1b CM |
4823 | slot = path->slots[0]; |
4824 | BUG_ON(slot < 0); | |
4825 | ||
afe5fea7 | 4826 | setup_items_for_insert(root, path, cpu_key, data_size, |
44871b1b | 4827 | total_data, total_size, nr); |
143bede5 | 4828 | return 0; |
62e2749e CM |
4829 | } |
4830 | ||
4831 | /* | |
4832 | * Given a key and some data, insert an item into the tree. | |
4833 | * This does all the path init required, making room in the tree if needed. | |
4834 | */ | |
e089f05c CM |
4835 | int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root |
4836 | *root, struct btrfs_key *cpu_key, void *data, u32 | |
4837 | data_size) | |
62e2749e CM |
4838 | { |
4839 | int ret = 0; | |
2c90e5d6 | 4840 | struct btrfs_path *path; |
5f39d397 CM |
4841 | struct extent_buffer *leaf; |
4842 | unsigned long ptr; | |
62e2749e | 4843 | |
2c90e5d6 | 4844 | path = btrfs_alloc_path(); |
db5b493a TI |
4845 | if (!path) |
4846 | return -ENOMEM; | |
2c90e5d6 | 4847 | ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size); |
62e2749e | 4848 | if (!ret) { |
5f39d397 CM |
4849 | leaf = path->nodes[0]; |
4850 | ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); | |
4851 | write_extent_buffer(leaf, data, ptr, data_size); | |
4852 | btrfs_mark_buffer_dirty(leaf); | |
62e2749e | 4853 | } |
2c90e5d6 | 4854 | btrfs_free_path(path); |
aa5d6bed | 4855 | return ret; |
be0e5c09 CM |
4856 | } |
4857 | ||
74123bd7 | 4858 | /* |
5de08d7d | 4859 | * delete the pointer from a given node. |
74123bd7 | 4860 | * |
d352ac68 CM |
4861 | * the tree should have been previously balanced so the deletion does not |
4862 | * empty a node. | |
74123bd7 | 4863 | */ |
afe5fea7 TI |
4864 | static void del_ptr(struct btrfs_root *root, struct btrfs_path *path, |
4865 | int level, int slot) | |
be0e5c09 | 4866 | { |
5f39d397 | 4867 | struct extent_buffer *parent = path->nodes[level]; |
7518a238 | 4868 | u32 nritems; |
f3ea38da | 4869 | int ret; |
be0e5c09 | 4870 | |
5f39d397 | 4871 | nritems = btrfs_header_nritems(parent); |
d397712b | 4872 | if (slot != nritems - 1) { |
0e411ece | 4873 | if (level) |
f3ea38da JS |
4874 | tree_mod_log_eb_move(root->fs_info, parent, slot, |
4875 | slot + 1, nritems - slot - 1); | |
5f39d397 CM |
4876 | memmove_extent_buffer(parent, |
4877 | btrfs_node_key_ptr_offset(slot), | |
4878 | btrfs_node_key_ptr_offset(slot + 1), | |
d6025579 CM |
4879 | sizeof(struct btrfs_key_ptr) * |
4880 | (nritems - slot - 1)); | |
57ba86c0 CM |
4881 | } else if (level) { |
4882 | ret = tree_mod_log_insert_key(root->fs_info, parent, slot, | |
c8cc6341 | 4883 | MOD_LOG_KEY_REMOVE, GFP_NOFS); |
57ba86c0 | 4884 | BUG_ON(ret < 0); |
bb803951 | 4885 | } |
f3ea38da | 4886 | |
7518a238 | 4887 | nritems--; |
5f39d397 | 4888 | btrfs_set_header_nritems(parent, nritems); |
7518a238 | 4889 | if (nritems == 0 && parent == root->node) { |
5f39d397 | 4890 | BUG_ON(btrfs_header_level(root->node) != 1); |
bb803951 | 4891 | /* just turn the root into a leaf and break */ |
5f39d397 | 4892 | btrfs_set_header_level(root->node, 0); |
bb803951 | 4893 | } else if (slot == 0) { |
5f39d397 CM |
4894 | struct btrfs_disk_key disk_key; |
4895 | ||
4896 | btrfs_node_key(parent, &disk_key, 0); | |
b7a0365e | 4897 | fixup_low_keys(root->fs_info, path, &disk_key, level + 1); |
be0e5c09 | 4898 | } |
d6025579 | 4899 | btrfs_mark_buffer_dirty(parent); |
be0e5c09 CM |
4900 | } |
4901 | ||
323ac95b CM |
4902 | /* |
4903 | * a helper function to delete the leaf pointed to by path->slots[1] and | |
5d4f98a2 | 4904 | * path->nodes[1]. |
323ac95b CM |
4905 | * |
4906 | * This deletes the pointer in path->nodes[1] and frees the leaf | |
4907 | * block extent. zero is returned if it all worked out, < 0 otherwise. | |
4908 | * | |
4909 | * The path must have already been setup for deleting the leaf, including | |
4910 | * all the proper balancing. path->nodes[1] must be locked. | |
4911 | */ | |
143bede5 JM |
4912 | static noinline void btrfs_del_leaf(struct btrfs_trans_handle *trans, |
4913 | struct btrfs_root *root, | |
4914 | struct btrfs_path *path, | |
4915 | struct extent_buffer *leaf) | |
323ac95b | 4916 | { |
5d4f98a2 | 4917 | WARN_ON(btrfs_header_generation(leaf) != trans->transid); |
afe5fea7 | 4918 | del_ptr(root, path, 1, path->slots[1]); |
323ac95b | 4919 | |
4d081c41 CM |
4920 | /* |
4921 | * btrfs_free_extent is expensive, we want to make sure we | |
4922 | * aren't holding any locks when we call it | |
4923 | */ | |
4924 | btrfs_unlock_up_safe(path, 0); | |
4925 | ||
f0486c68 YZ |
4926 | root_sub_used(root, leaf->len); |
4927 | ||
3083ee2e | 4928 | extent_buffer_get(leaf); |
5581a51a | 4929 | btrfs_free_tree_block(trans, root, leaf, 0, 1); |
3083ee2e | 4930 | free_extent_buffer_stale(leaf); |
323ac95b | 4931 | } |
74123bd7 CM |
4932 | /* |
4933 | * delete the item at the leaf level in path. If that empties | |
4934 | * the leaf, remove it from the tree | |
4935 | */ | |
85e21bac CM |
4936 | int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
4937 | struct btrfs_path *path, int slot, int nr) | |
be0e5c09 | 4938 | { |
5f39d397 CM |
4939 | struct extent_buffer *leaf; |
4940 | struct btrfs_item *item; | |
85e21bac CM |
4941 | int last_off; |
4942 | int dsize = 0; | |
aa5d6bed CM |
4943 | int ret = 0; |
4944 | int wret; | |
85e21bac | 4945 | int i; |
7518a238 | 4946 | u32 nritems; |
cfed81a0 CM |
4947 | struct btrfs_map_token token; |
4948 | ||
4949 | btrfs_init_map_token(&token); | |
be0e5c09 | 4950 | |
5f39d397 | 4951 | leaf = path->nodes[0]; |
85e21bac CM |
4952 | last_off = btrfs_item_offset_nr(leaf, slot + nr - 1); |
4953 | ||
4954 | for (i = 0; i < nr; i++) | |
4955 | dsize += btrfs_item_size_nr(leaf, slot + i); | |
4956 | ||
5f39d397 | 4957 | nritems = btrfs_header_nritems(leaf); |
be0e5c09 | 4958 | |
85e21bac | 4959 | if (slot + nr != nritems) { |
123abc88 | 4960 | int data_end = leaf_data_end(root, leaf); |
5f39d397 CM |
4961 | |
4962 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + | |
d6025579 CM |
4963 | data_end + dsize, |
4964 | btrfs_leaf_data(leaf) + data_end, | |
85e21bac | 4965 | last_off - data_end); |
5f39d397 | 4966 | |
85e21bac | 4967 | for (i = slot + nr; i < nritems; i++) { |
5f39d397 | 4968 | u32 ioff; |
db94535d | 4969 | |
dd3cc16b | 4970 | item = btrfs_item_nr(i); |
cfed81a0 CM |
4971 | ioff = btrfs_token_item_offset(leaf, item, &token); |
4972 | btrfs_set_token_item_offset(leaf, item, | |
4973 | ioff + dsize, &token); | |
0783fcfc | 4974 | } |
db94535d | 4975 | |
5f39d397 | 4976 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot), |
85e21bac | 4977 | btrfs_item_nr_offset(slot + nr), |
d6025579 | 4978 | sizeof(struct btrfs_item) * |
85e21bac | 4979 | (nritems - slot - nr)); |
be0e5c09 | 4980 | } |
85e21bac CM |
4981 | btrfs_set_header_nritems(leaf, nritems - nr); |
4982 | nritems -= nr; | |
5f39d397 | 4983 | |
74123bd7 | 4984 | /* delete the leaf if we've emptied it */ |
7518a238 | 4985 | if (nritems == 0) { |
5f39d397 CM |
4986 | if (leaf == root->node) { |
4987 | btrfs_set_header_level(leaf, 0); | |
9a8dd150 | 4988 | } else { |
f0486c68 | 4989 | btrfs_set_path_blocking(path); |
01d58472 | 4990 | clean_tree_block(trans, root->fs_info, leaf); |
143bede5 | 4991 | btrfs_del_leaf(trans, root, path, leaf); |
9a8dd150 | 4992 | } |
be0e5c09 | 4993 | } else { |
7518a238 | 4994 | int used = leaf_space_used(leaf, 0, nritems); |
aa5d6bed | 4995 | if (slot == 0) { |
5f39d397 CM |
4996 | struct btrfs_disk_key disk_key; |
4997 | ||
4998 | btrfs_item_key(leaf, &disk_key, 0); | |
b7a0365e | 4999 | fixup_low_keys(root->fs_info, path, &disk_key, 1); |
aa5d6bed | 5000 | } |
aa5d6bed | 5001 | |
74123bd7 | 5002 | /* delete the leaf if it is mostly empty */ |
d717aa1d | 5003 | if (used < BTRFS_LEAF_DATA_SIZE(root) / 3) { |
be0e5c09 CM |
5004 | /* push_leaf_left fixes the path. |
5005 | * make sure the path still points to our leaf | |
5006 | * for possible call to del_ptr below | |
5007 | */ | |
4920c9ac | 5008 | slot = path->slots[1]; |
5f39d397 CM |
5009 | extent_buffer_get(leaf); |
5010 | ||
b9473439 | 5011 | btrfs_set_path_blocking(path); |
99d8f83c CM |
5012 | wret = push_leaf_left(trans, root, path, 1, 1, |
5013 | 1, (u32)-1); | |
54aa1f4d | 5014 | if (wret < 0 && wret != -ENOSPC) |
aa5d6bed | 5015 | ret = wret; |
5f39d397 CM |
5016 | |
5017 | if (path->nodes[0] == leaf && | |
5018 | btrfs_header_nritems(leaf)) { | |
99d8f83c CM |
5019 | wret = push_leaf_right(trans, root, path, 1, |
5020 | 1, 1, 0); | |
54aa1f4d | 5021 | if (wret < 0 && wret != -ENOSPC) |
aa5d6bed CM |
5022 | ret = wret; |
5023 | } | |
5f39d397 CM |
5024 | |
5025 | if (btrfs_header_nritems(leaf) == 0) { | |
323ac95b | 5026 | path->slots[1] = slot; |
143bede5 | 5027 | btrfs_del_leaf(trans, root, path, leaf); |
5f39d397 | 5028 | free_extent_buffer(leaf); |
143bede5 | 5029 | ret = 0; |
5de08d7d | 5030 | } else { |
925baedd CM |
5031 | /* if we're still in the path, make sure |
5032 | * we're dirty. Otherwise, one of the | |
5033 | * push_leaf functions must have already | |
5034 | * dirtied this buffer | |
5035 | */ | |
5036 | if (path->nodes[0] == leaf) | |
5037 | btrfs_mark_buffer_dirty(leaf); | |
5f39d397 | 5038 | free_extent_buffer(leaf); |
be0e5c09 | 5039 | } |
d5719762 | 5040 | } else { |
5f39d397 | 5041 | btrfs_mark_buffer_dirty(leaf); |
be0e5c09 CM |
5042 | } |
5043 | } | |
aa5d6bed | 5044 | return ret; |
be0e5c09 CM |
5045 | } |
5046 | ||
7bb86316 | 5047 | /* |
925baedd | 5048 | * search the tree again to find a leaf with lesser keys |
7bb86316 CM |
5049 | * returns 0 if it found something or 1 if there are no lesser leaves. |
5050 | * returns < 0 on io errors. | |
d352ac68 CM |
5051 | * |
5052 | * This may release the path, and so you may lose any locks held at the | |
5053 | * time you call it. | |
7bb86316 | 5054 | */ |
16e7549f | 5055 | int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path) |
7bb86316 | 5056 | { |
925baedd CM |
5057 | struct btrfs_key key; |
5058 | struct btrfs_disk_key found_key; | |
5059 | int ret; | |
7bb86316 | 5060 | |
925baedd | 5061 | btrfs_item_key_to_cpu(path->nodes[0], &key, 0); |
7bb86316 | 5062 | |
e8b0d724 | 5063 | if (key.offset > 0) { |
925baedd | 5064 | key.offset--; |
e8b0d724 | 5065 | } else if (key.type > 0) { |
925baedd | 5066 | key.type--; |
e8b0d724 FDBM |
5067 | key.offset = (u64)-1; |
5068 | } else if (key.objectid > 0) { | |
925baedd | 5069 | key.objectid--; |
e8b0d724 FDBM |
5070 | key.type = (u8)-1; |
5071 | key.offset = (u64)-1; | |
5072 | } else { | |
925baedd | 5073 | return 1; |
e8b0d724 | 5074 | } |
7bb86316 | 5075 | |
b3b4aa74 | 5076 | btrfs_release_path(path); |
925baedd CM |
5077 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
5078 | if (ret < 0) | |
5079 | return ret; | |
5080 | btrfs_item_key(path->nodes[0], &found_key, 0); | |
5081 | ret = comp_keys(&found_key, &key); | |
337c6f68 FM |
5082 | /* |
5083 | * We might have had an item with the previous key in the tree right | |
5084 | * before we released our path. And after we released our path, that | |
5085 | * item might have been pushed to the first slot (0) of the leaf we | |
5086 | * were holding due to a tree balance. Alternatively, an item with the | |
5087 | * previous key can exist as the only element of a leaf (big fat item). | |
5088 | * Therefore account for these 2 cases, so that our callers (like | |
5089 | * btrfs_previous_item) don't miss an existing item with a key matching | |
5090 | * the previous key we computed above. | |
5091 | */ | |
5092 | if (ret <= 0) | |
925baedd CM |
5093 | return 0; |
5094 | return 1; | |
7bb86316 CM |
5095 | } |
5096 | ||
3f157a2f CM |
5097 | /* |
5098 | * A helper function to walk down the tree starting at min_key, and looking | |
de78b51a ES |
5099 | * for nodes or leaves that are have a minimum transaction id. |
5100 | * This is used by the btree defrag code, and tree logging | |
3f157a2f CM |
5101 | * |
5102 | * This does not cow, but it does stuff the starting key it finds back | |
5103 | * into min_key, so you can call btrfs_search_slot with cow=1 on the | |
5104 | * key and get a writable path. | |
5105 | * | |
5106 | * This does lock as it descends, and path->keep_locks should be set | |
5107 | * to 1 by the caller. | |
5108 | * | |
5109 | * This honors path->lowest_level to prevent descent past a given level | |
5110 | * of the tree. | |
5111 | * | |
d352ac68 CM |
5112 | * min_trans indicates the oldest transaction that you are interested |
5113 | * in walking through. Any nodes or leaves older than min_trans are | |
5114 | * skipped over (without reading them). | |
5115 | * | |
3f157a2f CM |
5116 | * returns zero if something useful was found, < 0 on error and 1 if there |
5117 | * was nothing in the tree that matched the search criteria. | |
5118 | */ | |
5119 | int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key, | |
de78b51a | 5120 | struct btrfs_path *path, |
3f157a2f CM |
5121 | u64 min_trans) |
5122 | { | |
5123 | struct extent_buffer *cur; | |
5124 | struct btrfs_key found_key; | |
5125 | int slot; | |
9652480b | 5126 | int sret; |
3f157a2f CM |
5127 | u32 nritems; |
5128 | int level; | |
5129 | int ret = 1; | |
f98de9b9 | 5130 | int keep_locks = path->keep_locks; |
3f157a2f | 5131 | |
f98de9b9 | 5132 | path->keep_locks = 1; |
3f157a2f | 5133 | again: |
bd681513 | 5134 | cur = btrfs_read_lock_root_node(root); |
3f157a2f | 5135 | level = btrfs_header_level(cur); |
e02119d5 | 5136 | WARN_ON(path->nodes[level]); |
3f157a2f | 5137 | path->nodes[level] = cur; |
bd681513 | 5138 | path->locks[level] = BTRFS_READ_LOCK; |
3f157a2f CM |
5139 | |
5140 | if (btrfs_header_generation(cur) < min_trans) { | |
5141 | ret = 1; | |
5142 | goto out; | |
5143 | } | |
d397712b | 5144 | while (1) { |
3f157a2f CM |
5145 | nritems = btrfs_header_nritems(cur); |
5146 | level = btrfs_header_level(cur); | |
9652480b | 5147 | sret = bin_search(cur, min_key, level, &slot); |
3f157a2f | 5148 | |
323ac95b CM |
5149 | /* at the lowest level, we're done, setup the path and exit */ |
5150 | if (level == path->lowest_level) { | |
e02119d5 CM |
5151 | if (slot >= nritems) |
5152 | goto find_next_key; | |
3f157a2f CM |
5153 | ret = 0; |
5154 | path->slots[level] = slot; | |
5155 | btrfs_item_key_to_cpu(cur, &found_key, slot); | |
5156 | goto out; | |
5157 | } | |
9652480b Y |
5158 | if (sret && slot > 0) |
5159 | slot--; | |
3f157a2f | 5160 | /* |
de78b51a ES |
5161 | * check this node pointer against the min_trans parameters. |
5162 | * If it is too old, old, skip to the next one. | |
3f157a2f | 5163 | */ |
d397712b | 5164 | while (slot < nritems) { |
3f157a2f | 5165 | u64 gen; |
e02119d5 | 5166 | |
3f157a2f CM |
5167 | gen = btrfs_node_ptr_generation(cur, slot); |
5168 | if (gen < min_trans) { | |
5169 | slot++; | |
5170 | continue; | |
5171 | } | |
de78b51a | 5172 | break; |
3f157a2f | 5173 | } |
e02119d5 | 5174 | find_next_key: |
3f157a2f CM |
5175 | /* |
5176 | * we didn't find a candidate key in this node, walk forward | |
5177 | * and find another one | |
5178 | */ | |
5179 | if (slot >= nritems) { | |
e02119d5 | 5180 | path->slots[level] = slot; |
b4ce94de | 5181 | btrfs_set_path_blocking(path); |
e02119d5 | 5182 | sret = btrfs_find_next_key(root, path, min_key, level, |
de78b51a | 5183 | min_trans); |
e02119d5 | 5184 | if (sret == 0) { |
b3b4aa74 | 5185 | btrfs_release_path(path); |
3f157a2f CM |
5186 | goto again; |
5187 | } else { | |
5188 | goto out; | |
5189 | } | |
5190 | } | |
5191 | /* save our key for returning back */ | |
5192 | btrfs_node_key_to_cpu(cur, &found_key, slot); | |
5193 | path->slots[level] = slot; | |
5194 | if (level == path->lowest_level) { | |
5195 | ret = 0; | |
3f157a2f CM |
5196 | goto out; |
5197 | } | |
b4ce94de | 5198 | btrfs_set_path_blocking(path); |
3f157a2f | 5199 | cur = read_node_slot(root, cur, slot); |
79787eaa | 5200 | BUG_ON(!cur); /* -ENOMEM */ |
3f157a2f | 5201 | |
bd681513 | 5202 | btrfs_tree_read_lock(cur); |
b4ce94de | 5203 | |
bd681513 | 5204 | path->locks[level - 1] = BTRFS_READ_LOCK; |
3f157a2f | 5205 | path->nodes[level - 1] = cur; |
f7c79f30 | 5206 | unlock_up(path, level, 1, 0, NULL); |
bd681513 | 5207 | btrfs_clear_path_blocking(path, NULL, 0); |
3f157a2f CM |
5208 | } |
5209 | out: | |
f98de9b9 FM |
5210 | path->keep_locks = keep_locks; |
5211 | if (ret == 0) { | |
5212 | btrfs_unlock_up_safe(path, path->lowest_level + 1); | |
5213 | btrfs_set_path_blocking(path); | |
3f157a2f | 5214 | memcpy(min_key, &found_key, sizeof(found_key)); |
f98de9b9 | 5215 | } |
3f157a2f CM |
5216 | return ret; |
5217 | } | |
5218 | ||
7069830a AB |
5219 | static void tree_move_down(struct btrfs_root *root, |
5220 | struct btrfs_path *path, | |
5221 | int *level, int root_level) | |
5222 | { | |
74dd17fb | 5223 | BUG_ON(*level == 0); |
7069830a AB |
5224 | path->nodes[*level - 1] = read_node_slot(root, path->nodes[*level], |
5225 | path->slots[*level]); | |
5226 | path->slots[*level - 1] = 0; | |
5227 | (*level)--; | |
5228 | } | |
5229 | ||
5230 | static int tree_move_next_or_upnext(struct btrfs_root *root, | |
5231 | struct btrfs_path *path, | |
5232 | int *level, int root_level) | |
5233 | { | |
5234 | int ret = 0; | |
5235 | int nritems; | |
5236 | nritems = btrfs_header_nritems(path->nodes[*level]); | |
5237 | ||
5238 | path->slots[*level]++; | |
5239 | ||
74dd17fb | 5240 | while (path->slots[*level] >= nritems) { |
7069830a AB |
5241 | if (*level == root_level) |
5242 | return -1; | |
5243 | ||
5244 | /* move upnext */ | |
5245 | path->slots[*level] = 0; | |
5246 | free_extent_buffer(path->nodes[*level]); | |
5247 | path->nodes[*level] = NULL; | |
5248 | (*level)++; | |
5249 | path->slots[*level]++; | |
5250 | ||
5251 | nritems = btrfs_header_nritems(path->nodes[*level]); | |
5252 | ret = 1; | |
5253 | } | |
5254 | return ret; | |
5255 | } | |
5256 | ||
5257 | /* | |
5258 | * Returns 1 if it had to move up and next. 0 is returned if it moved only next | |
5259 | * or down. | |
5260 | */ | |
5261 | static int tree_advance(struct btrfs_root *root, | |
5262 | struct btrfs_path *path, | |
5263 | int *level, int root_level, | |
5264 | int allow_down, | |
5265 | struct btrfs_key *key) | |
5266 | { | |
5267 | int ret; | |
5268 | ||
5269 | if (*level == 0 || !allow_down) { | |
5270 | ret = tree_move_next_or_upnext(root, path, level, root_level); | |
5271 | } else { | |
5272 | tree_move_down(root, path, level, root_level); | |
5273 | ret = 0; | |
5274 | } | |
5275 | if (ret >= 0) { | |
5276 | if (*level == 0) | |
5277 | btrfs_item_key_to_cpu(path->nodes[*level], key, | |
5278 | path->slots[*level]); | |
5279 | else | |
5280 | btrfs_node_key_to_cpu(path->nodes[*level], key, | |
5281 | path->slots[*level]); | |
5282 | } | |
5283 | return ret; | |
5284 | } | |
5285 | ||
5286 | static int tree_compare_item(struct btrfs_root *left_root, | |
5287 | struct btrfs_path *left_path, | |
5288 | struct btrfs_path *right_path, | |
5289 | char *tmp_buf) | |
5290 | { | |
5291 | int cmp; | |
5292 | int len1, len2; | |
5293 | unsigned long off1, off2; | |
5294 | ||
5295 | len1 = btrfs_item_size_nr(left_path->nodes[0], left_path->slots[0]); | |
5296 | len2 = btrfs_item_size_nr(right_path->nodes[0], right_path->slots[0]); | |
5297 | if (len1 != len2) | |
5298 | return 1; | |
5299 | ||
5300 | off1 = btrfs_item_ptr_offset(left_path->nodes[0], left_path->slots[0]); | |
5301 | off2 = btrfs_item_ptr_offset(right_path->nodes[0], | |
5302 | right_path->slots[0]); | |
5303 | ||
5304 | read_extent_buffer(left_path->nodes[0], tmp_buf, off1, len1); | |
5305 | ||
5306 | cmp = memcmp_extent_buffer(right_path->nodes[0], tmp_buf, off2, len1); | |
5307 | if (cmp) | |
5308 | return 1; | |
5309 | return 0; | |
5310 | } | |
5311 | ||
5312 | #define ADVANCE 1 | |
5313 | #define ADVANCE_ONLY_NEXT -1 | |
5314 | ||
5315 | /* | |
5316 | * This function compares two trees and calls the provided callback for | |
5317 | * every changed/new/deleted item it finds. | |
5318 | * If shared tree blocks are encountered, whole subtrees are skipped, making | |
5319 | * the compare pretty fast on snapshotted subvolumes. | |
5320 | * | |
5321 | * This currently works on commit roots only. As commit roots are read only, | |
5322 | * we don't do any locking. The commit roots are protected with transactions. | |
5323 | * Transactions are ended and rejoined when a commit is tried in between. | |
5324 | * | |
5325 | * This function checks for modifications done to the trees while comparing. | |
5326 | * If it detects a change, it aborts immediately. | |
5327 | */ | |
5328 | int btrfs_compare_trees(struct btrfs_root *left_root, | |
5329 | struct btrfs_root *right_root, | |
5330 | btrfs_changed_cb_t changed_cb, void *ctx) | |
5331 | { | |
5332 | int ret; | |
5333 | int cmp; | |
7069830a AB |
5334 | struct btrfs_path *left_path = NULL; |
5335 | struct btrfs_path *right_path = NULL; | |
5336 | struct btrfs_key left_key; | |
5337 | struct btrfs_key right_key; | |
5338 | char *tmp_buf = NULL; | |
5339 | int left_root_level; | |
5340 | int right_root_level; | |
5341 | int left_level; | |
5342 | int right_level; | |
5343 | int left_end_reached; | |
5344 | int right_end_reached; | |
5345 | int advance_left; | |
5346 | int advance_right; | |
5347 | u64 left_blockptr; | |
5348 | u64 right_blockptr; | |
6baa4293 FM |
5349 | u64 left_gen; |
5350 | u64 right_gen; | |
7069830a AB |
5351 | |
5352 | left_path = btrfs_alloc_path(); | |
5353 | if (!left_path) { | |
5354 | ret = -ENOMEM; | |
5355 | goto out; | |
5356 | } | |
5357 | right_path = btrfs_alloc_path(); | |
5358 | if (!right_path) { | |
5359 | ret = -ENOMEM; | |
5360 | goto out; | |
5361 | } | |
5362 | ||
707e8a07 | 5363 | tmp_buf = kmalloc(left_root->nodesize, GFP_NOFS); |
7069830a AB |
5364 | if (!tmp_buf) { |
5365 | ret = -ENOMEM; | |
5366 | goto out; | |
5367 | } | |
5368 | ||
5369 | left_path->search_commit_root = 1; | |
5370 | left_path->skip_locking = 1; | |
5371 | right_path->search_commit_root = 1; | |
5372 | right_path->skip_locking = 1; | |
5373 | ||
7069830a AB |
5374 | /* |
5375 | * Strategy: Go to the first items of both trees. Then do | |
5376 | * | |
5377 | * If both trees are at level 0 | |
5378 | * Compare keys of current items | |
5379 | * If left < right treat left item as new, advance left tree | |
5380 | * and repeat | |
5381 | * If left > right treat right item as deleted, advance right tree | |
5382 | * and repeat | |
5383 | * If left == right do deep compare of items, treat as changed if | |
5384 | * needed, advance both trees and repeat | |
5385 | * If both trees are at the same level but not at level 0 | |
5386 | * Compare keys of current nodes/leafs | |
5387 | * If left < right advance left tree and repeat | |
5388 | * If left > right advance right tree and repeat | |
5389 | * If left == right compare blockptrs of the next nodes/leafs | |
5390 | * If they match advance both trees but stay at the same level | |
5391 | * and repeat | |
5392 | * If they don't match advance both trees while allowing to go | |
5393 | * deeper and repeat | |
5394 | * If tree levels are different | |
5395 | * Advance the tree that needs it and repeat | |
5396 | * | |
5397 | * Advancing a tree means: | |
5398 | * If we are at level 0, try to go to the next slot. If that's not | |
5399 | * possible, go one level up and repeat. Stop when we found a level | |
5400 | * where we could go to the next slot. We may at this point be on a | |
5401 | * node or a leaf. | |
5402 | * | |
5403 | * If we are not at level 0 and not on shared tree blocks, go one | |
5404 | * level deeper. | |
5405 | * | |
5406 | * If we are not at level 0 and on shared tree blocks, go one slot to | |
5407 | * the right if possible or go up and right. | |
5408 | */ | |
5409 | ||
3f8a18cc | 5410 | down_read(&left_root->fs_info->commit_root_sem); |
7069830a AB |
5411 | left_level = btrfs_header_level(left_root->commit_root); |
5412 | left_root_level = left_level; | |
5413 | left_path->nodes[left_level] = left_root->commit_root; | |
5414 | extent_buffer_get(left_path->nodes[left_level]); | |
5415 | ||
5416 | right_level = btrfs_header_level(right_root->commit_root); | |
5417 | right_root_level = right_level; | |
5418 | right_path->nodes[right_level] = right_root->commit_root; | |
5419 | extent_buffer_get(right_path->nodes[right_level]); | |
3f8a18cc | 5420 | up_read(&left_root->fs_info->commit_root_sem); |
7069830a AB |
5421 | |
5422 | if (left_level == 0) | |
5423 | btrfs_item_key_to_cpu(left_path->nodes[left_level], | |
5424 | &left_key, left_path->slots[left_level]); | |
5425 | else | |
5426 | btrfs_node_key_to_cpu(left_path->nodes[left_level], | |
5427 | &left_key, left_path->slots[left_level]); | |
5428 | if (right_level == 0) | |
5429 | btrfs_item_key_to_cpu(right_path->nodes[right_level], | |
5430 | &right_key, right_path->slots[right_level]); | |
5431 | else | |
5432 | btrfs_node_key_to_cpu(right_path->nodes[right_level], | |
5433 | &right_key, right_path->slots[right_level]); | |
5434 | ||
5435 | left_end_reached = right_end_reached = 0; | |
5436 | advance_left = advance_right = 0; | |
5437 | ||
5438 | while (1) { | |
7069830a AB |
5439 | if (advance_left && !left_end_reached) { |
5440 | ret = tree_advance(left_root, left_path, &left_level, | |
5441 | left_root_level, | |
5442 | advance_left != ADVANCE_ONLY_NEXT, | |
5443 | &left_key); | |
5444 | if (ret < 0) | |
5445 | left_end_reached = ADVANCE; | |
5446 | advance_left = 0; | |
5447 | } | |
5448 | if (advance_right && !right_end_reached) { | |
5449 | ret = tree_advance(right_root, right_path, &right_level, | |
5450 | right_root_level, | |
5451 | advance_right != ADVANCE_ONLY_NEXT, | |
5452 | &right_key); | |
5453 | if (ret < 0) | |
5454 | right_end_reached = ADVANCE; | |
5455 | advance_right = 0; | |
5456 | } | |
5457 | ||
5458 | if (left_end_reached && right_end_reached) { | |
5459 | ret = 0; | |
5460 | goto out; | |
5461 | } else if (left_end_reached) { | |
5462 | if (right_level == 0) { | |
5463 | ret = changed_cb(left_root, right_root, | |
5464 | left_path, right_path, | |
5465 | &right_key, | |
5466 | BTRFS_COMPARE_TREE_DELETED, | |
5467 | ctx); | |
5468 | if (ret < 0) | |
5469 | goto out; | |
5470 | } | |
5471 | advance_right = ADVANCE; | |
5472 | continue; | |
5473 | } else if (right_end_reached) { | |
5474 | if (left_level == 0) { | |
5475 | ret = changed_cb(left_root, right_root, | |
5476 | left_path, right_path, | |
5477 | &left_key, | |
5478 | BTRFS_COMPARE_TREE_NEW, | |
5479 | ctx); | |
5480 | if (ret < 0) | |
5481 | goto out; | |
5482 | } | |
5483 | advance_left = ADVANCE; | |
5484 | continue; | |
5485 | } | |
5486 | ||
5487 | if (left_level == 0 && right_level == 0) { | |
5488 | cmp = btrfs_comp_cpu_keys(&left_key, &right_key); | |
5489 | if (cmp < 0) { | |
5490 | ret = changed_cb(left_root, right_root, | |
5491 | left_path, right_path, | |
5492 | &left_key, | |
5493 | BTRFS_COMPARE_TREE_NEW, | |
5494 | ctx); | |
5495 | if (ret < 0) | |
5496 | goto out; | |
5497 | advance_left = ADVANCE; | |
5498 | } else if (cmp > 0) { | |
5499 | ret = changed_cb(left_root, right_root, | |
5500 | left_path, right_path, | |
5501 | &right_key, | |
5502 | BTRFS_COMPARE_TREE_DELETED, | |
5503 | ctx); | |
5504 | if (ret < 0) | |
5505 | goto out; | |
5506 | advance_right = ADVANCE; | |
5507 | } else { | |
b99d9a6a | 5508 | enum btrfs_compare_tree_result result; |
ba5e8f2e | 5509 | |
74dd17fb | 5510 | WARN_ON(!extent_buffer_uptodate(left_path->nodes[0])); |
7069830a AB |
5511 | ret = tree_compare_item(left_root, left_path, |
5512 | right_path, tmp_buf); | |
ba5e8f2e | 5513 | if (ret) |
b99d9a6a | 5514 | result = BTRFS_COMPARE_TREE_CHANGED; |
ba5e8f2e | 5515 | else |
b99d9a6a | 5516 | result = BTRFS_COMPARE_TREE_SAME; |
ba5e8f2e JB |
5517 | ret = changed_cb(left_root, right_root, |
5518 | left_path, right_path, | |
b99d9a6a | 5519 | &left_key, result, ctx); |
ba5e8f2e JB |
5520 | if (ret < 0) |
5521 | goto out; | |
7069830a AB |
5522 | advance_left = ADVANCE; |
5523 | advance_right = ADVANCE; | |
5524 | } | |
5525 | } else if (left_level == right_level) { | |
5526 | cmp = btrfs_comp_cpu_keys(&left_key, &right_key); | |
5527 | if (cmp < 0) { | |
5528 | advance_left = ADVANCE; | |
5529 | } else if (cmp > 0) { | |
5530 | advance_right = ADVANCE; | |
5531 | } else { | |
5532 | left_blockptr = btrfs_node_blockptr( | |
5533 | left_path->nodes[left_level], | |
5534 | left_path->slots[left_level]); | |
5535 | right_blockptr = btrfs_node_blockptr( | |
5536 | right_path->nodes[right_level], | |
5537 | right_path->slots[right_level]); | |
6baa4293 FM |
5538 | left_gen = btrfs_node_ptr_generation( |
5539 | left_path->nodes[left_level], | |
5540 | left_path->slots[left_level]); | |
5541 | right_gen = btrfs_node_ptr_generation( | |
5542 | right_path->nodes[right_level], | |
5543 | right_path->slots[right_level]); | |
5544 | if (left_blockptr == right_blockptr && | |
5545 | left_gen == right_gen) { | |
7069830a AB |
5546 | /* |
5547 | * As we're on a shared block, don't | |
5548 | * allow to go deeper. | |
5549 | */ | |
5550 | advance_left = ADVANCE_ONLY_NEXT; | |
5551 | advance_right = ADVANCE_ONLY_NEXT; | |
5552 | } else { | |
5553 | advance_left = ADVANCE; | |
5554 | advance_right = ADVANCE; | |
5555 | } | |
5556 | } | |
5557 | } else if (left_level < right_level) { | |
5558 | advance_right = ADVANCE; | |
5559 | } else { | |
5560 | advance_left = ADVANCE; | |
5561 | } | |
5562 | } | |
5563 | ||
5564 | out: | |
5565 | btrfs_free_path(left_path); | |
5566 | btrfs_free_path(right_path); | |
5567 | kfree(tmp_buf); | |
7069830a AB |
5568 | return ret; |
5569 | } | |
5570 | ||
3f157a2f CM |
5571 | /* |
5572 | * this is similar to btrfs_next_leaf, but does not try to preserve | |
5573 | * and fixup the path. It looks for and returns the next key in the | |
de78b51a | 5574 | * tree based on the current path and the min_trans parameters. |
3f157a2f CM |
5575 | * |
5576 | * 0 is returned if another key is found, < 0 if there are any errors | |
5577 | * and 1 is returned if there are no higher keys in the tree | |
5578 | * | |
5579 | * path->keep_locks should be set to 1 on the search made before | |
5580 | * calling this function. | |
5581 | */ | |
e7a84565 | 5582 | int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path, |
de78b51a | 5583 | struct btrfs_key *key, int level, u64 min_trans) |
e7a84565 | 5584 | { |
e7a84565 CM |
5585 | int slot; |
5586 | struct extent_buffer *c; | |
5587 | ||
934d375b | 5588 | WARN_ON(!path->keep_locks); |
d397712b | 5589 | while (level < BTRFS_MAX_LEVEL) { |
e7a84565 CM |
5590 | if (!path->nodes[level]) |
5591 | return 1; | |
5592 | ||
5593 | slot = path->slots[level] + 1; | |
5594 | c = path->nodes[level]; | |
3f157a2f | 5595 | next: |
e7a84565 | 5596 | if (slot >= btrfs_header_nritems(c)) { |
33c66f43 YZ |
5597 | int ret; |
5598 | int orig_lowest; | |
5599 | struct btrfs_key cur_key; | |
5600 | if (level + 1 >= BTRFS_MAX_LEVEL || | |
5601 | !path->nodes[level + 1]) | |
e7a84565 | 5602 | return 1; |
33c66f43 YZ |
5603 | |
5604 | if (path->locks[level + 1]) { | |
5605 | level++; | |
5606 | continue; | |
5607 | } | |
5608 | ||
5609 | slot = btrfs_header_nritems(c) - 1; | |
5610 | if (level == 0) | |
5611 | btrfs_item_key_to_cpu(c, &cur_key, slot); | |
5612 | else | |
5613 | btrfs_node_key_to_cpu(c, &cur_key, slot); | |
5614 | ||
5615 | orig_lowest = path->lowest_level; | |
b3b4aa74 | 5616 | btrfs_release_path(path); |
33c66f43 YZ |
5617 | path->lowest_level = level; |
5618 | ret = btrfs_search_slot(NULL, root, &cur_key, path, | |
5619 | 0, 0); | |
5620 | path->lowest_level = orig_lowest; | |
5621 | if (ret < 0) | |
5622 | return ret; | |
5623 | ||
5624 | c = path->nodes[level]; | |
5625 | slot = path->slots[level]; | |
5626 | if (ret == 0) | |
5627 | slot++; | |
5628 | goto next; | |
e7a84565 | 5629 | } |
33c66f43 | 5630 | |
e7a84565 CM |
5631 | if (level == 0) |
5632 | btrfs_item_key_to_cpu(c, key, slot); | |
3f157a2f | 5633 | else { |
3f157a2f CM |
5634 | u64 gen = btrfs_node_ptr_generation(c, slot); |
5635 | ||
3f157a2f CM |
5636 | if (gen < min_trans) { |
5637 | slot++; | |
5638 | goto next; | |
5639 | } | |
e7a84565 | 5640 | btrfs_node_key_to_cpu(c, key, slot); |
3f157a2f | 5641 | } |
e7a84565 CM |
5642 | return 0; |
5643 | } | |
5644 | return 1; | |
5645 | } | |
5646 | ||
97571fd0 | 5647 | /* |
925baedd | 5648 | * search the tree again to find a leaf with greater keys |
0f70abe2 CM |
5649 | * returns 0 if it found something or 1 if there are no greater leaves. |
5650 | * returns < 0 on io errors. | |
97571fd0 | 5651 | */ |
234b63a0 | 5652 | int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path) |
3d7806ec JS |
5653 | { |
5654 | return btrfs_next_old_leaf(root, path, 0); | |
5655 | } | |
5656 | ||
5657 | int btrfs_next_old_leaf(struct btrfs_root *root, struct btrfs_path *path, | |
5658 | u64 time_seq) | |
d97e63b6 CM |
5659 | { |
5660 | int slot; | |
8e73f275 | 5661 | int level; |
5f39d397 | 5662 | struct extent_buffer *c; |
8e73f275 | 5663 | struct extent_buffer *next; |
925baedd CM |
5664 | struct btrfs_key key; |
5665 | u32 nritems; | |
5666 | int ret; | |
8e73f275 | 5667 | int old_spinning = path->leave_spinning; |
bd681513 | 5668 | int next_rw_lock = 0; |
925baedd CM |
5669 | |
5670 | nritems = btrfs_header_nritems(path->nodes[0]); | |
d397712b | 5671 | if (nritems == 0) |
925baedd | 5672 | return 1; |
925baedd | 5673 | |
8e73f275 CM |
5674 | btrfs_item_key_to_cpu(path->nodes[0], &key, nritems - 1); |
5675 | again: | |
5676 | level = 1; | |
5677 | next = NULL; | |
bd681513 | 5678 | next_rw_lock = 0; |
b3b4aa74 | 5679 | btrfs_release_path(path); |
8e73f275 | 5680 | |
a2135011 | 5681 | path->keep_locks = 1; |
31533fb2 | 5682 | path->leave_spinning = 1; |
8e73f275 | 5683 | |
3d7806ec JS |
5684 | if (time_seq) |
5685 | ret = btrfs_search_old_slot(root, &key, path, time_seq); | |
5686 | else | |
5687 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); | |
925baedd CM |
5688 | path->keep_locks = 0; |
5689 | ||
5690 | if (ret < 0) | |
5691 | return ret; | |
5692 | ||
a2135011 | 5693 | nritems = btrfs_header_nritems(path->nodes[0]); |
168fd7d2 CM |
5694 | /* |
5695 | * by releasing the path above we dropped all our locks. A balance | |
5696 | * could have added more items next to the key that used to be | |
5697 | * at the very end of the block. So, check again here and | |
5698 | * advance the path if there are now more items available. | |
5699 | */ | |
a2135011 | 5700 | if (nritems > 0 && path->slots[0] < nritems - 1) { |
e457afec YZ |
5701 | if (ret == 0) |
5702 | path->slots[0]++; | |
8e73f275 | 5703 | ret = 0; |
925baedd CM |
5704 | goto done; |
5705 | } | |
0b43e04f LB |
5706 | /* |
5707 | * So the above check misses one case: | |
5708 | * - after releasing the path above, someone has removed the item that | |
5709 | * used to be at the very end of the block, and balance between leafs | |
5710 | * gets another one with bigger key.offset to replace it. | |
5711 | * | |
5712 | * This one should be returned as well, or we can get leaf corruption | |
5713 | * later(esp. in __btrfs_drop_extents()). | |
5714 | * | |
5715 | * And a bit more explanation about this check, | |
5716 | * with ret > 0, the key isn't found, the path points to the slot | |
5717 | * where it should be inserted, so the path->slots[0] item must be the | |
5718 | * bigger one. | |
5719 | */ | |
5720 | if (nritems > 0 && ret > 0 && path->slots[0] == nritems - 1) { | |
5721 | ret = 0; | |
5722 | goto done; | |
5723 | } | |
d97e63b6 | 5724 | |
d397712b | 5725 | while (level < BTRFS_MAX_LEVEL) { |
8e73f275 CM |
5726 | if (!path->nodes[level]) { |
5727 | ret = 1; | |
5728 | goto done; | |
5729 | } | |
5f39d397 | 5730 | |
d97e63b6 CM |
5731 | slot = path->slots[level] + 1; |
5732 | c = path->nodes[level]; | |
5f39d397 | 5733 | if (slot >= btrfs_header_nritems(c)) { |
d97e63b6 | 5734 | level++; |
8e73f275 CM |
5735 | if (level == BTRFS_MAX_LEVEL) { |
5736 | ret = 1; | |
5737 | goto done; | |
5738 | } | |
d97e63b6 CM |
5739 | continue; |
5740 | } | |
5f39d397 | 5741 | |
925baedd | 5742 | if (next) { |
bd681513 | 5743 | btrfs_tree_unlock_rw(next, next_rw_lock); |
5f39d397 | 5744 | free_extent_buffer(next); |
925baedd | 5745 | } |
5f39d397 | 5746 | |
8e73f275 | 5747 | next = c; |
bd681513 | 5748 | next_rw_lock = path->locks[level]; |
8e73f275 | 5749 | ret = read_block_for_search(NULL, root, path, &next, level, |
5d9e75c4 | 5750 | slot, &key, 0); |
8e73f275 CM |
5751 | if (ret == -EAGAIN) |
5752 | goto again; | |
5f39d397 | 5753 | |
76a05b35 | 5754 | if (ret < 0) { |
b3b4aa74 | 5755 | btrfs_release_path(path); |
76a05b35 CM |
5756 | goto done; |
5757 | } | |
5758 | ||
5cd57b2c | 5759 | if (!path->skip_locking) { |
bd681513 | 5760 | ret = btrfs_try_tree_read_lock(next); |
d42244a0 JS |
5761 | if (!ret && time_seq) { |
5762 | /* | |
5763 | * If we don't get the lock, we may be racing | |
5764 | * with push_leaf_left, holding that lock while | |
5765 | * itself waiting for the leaf we've currently | |
5766 | * locked. To solve this situation, we give up | |
5767 | * on our lock and cycle. | |
5768 | */ | |
cf538830 | 5769 | free_extent_buffer(next); |
d42244a0 JS |
5770 | btrfs_release_path(path); |
5771 | cond_resched(); | |
5772 | goto again; | |
5773 | } | |
8e73f275 CM |
5774 | if (!ret) { |
5775 | btrfs_set_path_blocking(path); | |
bd681513 | 5776 | btrfs_tree_read_lock(next); |
31533fb2 | 5777 | btrfs_clear_path_blocking(path, next, |
bd681513 | 5778 | BTRFS_READ_LOCK); |
8e73f275 | 5779 | } |
31533fb2 | 5780 | next_rw_lock = BTRFS_READ_LOCK; |
5cd57b2c | 5781 | } |
d97e63b6 CM |
5782 | break; |
5783 | } | |
5784 | path->slots[level] = slot; | |
d397712b | 5785 | while (1) { |
d97e63b6 CM |
5786 | level--; |
5787 | c = path->nodes[level]; | |
925baedd | 5788 | if (path->locks[level]) |
bd681513 | 5789 | btrfs_tree_unlock_rw(c, path->locks[level]); |
8e73f275 | 5790 | |
5f39d397 | 5791 | free_extent_buffer(c); |
d97e63b6 CM |
5792 | path->nodes[level] = next; |
5793 | path->slots[level] = 0; | |
a74a4b97 | 5794 | if (!path->skip_locking) |
bd681513 | 5795 | path->locks[level] = next_rw_lock; |
d97e63b6 CM |
5796 | if (!level) |
5797 | break; | |
b4ce94de | 5798 | |
8e73f275 | 5799 | ret = read_block_for_search(NULL, root, path, &next, level, |
5d9e75c4 | 5800 | 0, &key, 0); |
8e73f275 CM |
5801 | if (ret == -EAGAIN) |
5802 | goto again; | |
5803 | ||
76a05b35 | 5804 | if (ret < 0) { |
b3b4aa74 | 5805 | btrfs_release_path(path); |
76a05b35 CM |
5806 | goto done; |
5807 | } | |
5808 | ||
5cd57b2c | 5809 | if (!path->skip_locking) { |
bd681513 | 5810 | ret = btrfs_try_tree_read_lock(next); |
8e73f275 CM |
5811 | if (!ret) { |
5812 | btrfs_set_path_blocking(path); | |
bd681513 | 5813 | btrfs_tree_read_lock(next); |
31533fb2 | 5814 | btrfs_clear_path_blocking(path, next, |
bd681513 CM |
5815 | BTRFS_READ_LOCK); |
5816 | } | |
31533fb2 | 5817 | next_rw_lock = BTRFS_READ_LOCK; |
5cd57b2c | 5818 | } |
d97e63b6 | 5819 | } |
8e73f275 | 5820 | ret = 0; |
925baedd | 5821 | done: |
f7c79f30 | 5822 | unlock_up(path, 0, 1, 0, NULL); |
8e73f275 CM |
5823 | path->leave_spinning = old_spinning; |
5824 | if (!old_spinning) | |
5825 | btrfs_set_path_blocking(path); | |
5826 | ||
5827 | return ret; | |
d97e63b6 | 5828 | } |
0b86a832 | 5829 | |
3f157a2f CM |
5830 | /* |
5831 | * this uses btrfs_prev_leaf to walk backwards in the tree, and keeps | |
5832 | * searching until it gets past min_objectid or finds an item of 'type' | |
5833 | * | |
5834 | * returns 0 if something is found, 1 if nothing was found and < 0 on error | |
5835 | */ | |
0b86a832 CM |
5836 | int btrfs_previous_item(struct btrfs_root *root, |
5837 | struct btrfs_path *path, u64 min_objectid, | |
5838 | int type) | |
5839 | { | |
5840 | struct btrfs_key found_key; | |
5841 | struct extent_buffer *leaf; | |
e02119d5 | 5842 | u32 nritems; |
0b86a832 CM |
5843 | int ret; |
5844 | ||
d397712b | 5845 | while (1) { |
0b86a832 | 5846 | if (path->slots[0] == 0) { |
b4ce94de | 5847 | btrfs_set_path_blocking(path); |
0b86a832 CM |
5848 | ret = btrfs_prev_leaf(root, path); |
5849 | if (ret != 0) | |
5850 | return ret; | |
5851 | } else { | |
5852 | path->slots[0]--; | |
5853 | } | |
5854 | leaf = path->nodes[0]; | |
e02119d5 CM |
5855 | nritems = btrfs_header_nritems(leaf); |
5856 | if (nritems == 0) | |
5857 | return 1; | |
5858 | if (path->slots[0] == nritems) | |
5859 | path->slots[0]--; | |
5860 | ||
0b86a832 | 5861 | btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); |
e02119d5 CM |
5862 | if (found_key.objectid < min_objectid) |
5863 | break; | |
0a4eefbb YZ |
5864 | if (found_key.type == type) |
5865 | return 0; | |
e02119d5 CM |
5866 | if (found_key.objectid == min_objectid && |
5867 | found_key.type < type) | |
5868 | break; | |
0b86a832 CM |
5869 | } |
5870 | return 1; | |
5871 | } | |
ade2e0b3 WS |
5872 | |
5873 | /* | |
5874 | * search in extent tree to find a previous Metadata/Data extent item with | |
5875 | * min objecitd. | |
5876 | * | |
5877 | * returns 0 if something is found, 1 if nothing was found and < 0 on error | |
5878 | */ | |
5879 | int btrfs_previous_extent_item(struct btrfs_root *root, | |
5880 | struct btrfs_path *path, u64 min_objectid) | |
5881 | { | |
5882 | struct btrfs_key found_key; | |
5883 | struct extent_buffer *leaf; | |
5884 | u32 nritems; | |
5885 | int ret; | |
5886 | ||
5887 | while (1) { | |
5888 | if (path->slots[0] == 0) { | |
5889 | btrfs_set_path_blocking(path); | |
5890 | ret = btrfs_prev_leaf(root, path); | |
5891 | if (ret != 0) | |
5892 | return ret; | |
5893 | } else { | |
5894 | path->slots[0]--; | |
5895 | } | |
5896 | leaf = path->nodes[0]; | |
5897 | nritems = btrfs_header_nritems(leaf); | |
5898 | if (nritems == 0) | |
5899 | return 1; | |
5900 | if (path->slots[0] == nritems) | |
5901 | path->slots[0]--; | |
5902 | ||
5903 | btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); | |
5904 | if (found_key.objectid < min_objectid) | |
5905 | break; | |
5906 | if (found_key.type == BTRFS_EXTENT_ITEM_KEY || | |
5907 | found_key.type == BTRFS_METADATA_ITEM_KEY) | |
5908 | return 0; | |
5909 | if (found_key.objectid == min_objectid && | |
5910 | found_key.type < BTRFS_EXTENT_ITEM_KEY) | |
5911 | break; | |
5912 | } | |
5913 | return 1; | |
5914 | } |