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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> |
8f282f71 | 22 | #include <linux/vmalloc.h> |
eb60ceac CM |
23 | #include "ctree.h" |
24 | #include "disk-io.h" | |
7f5c1516 | 25 | #include "transaction.h" |
5f39d397 | 26 | #include "print-tree.h" |
925baedd | 27 | #include "locking.h" |
9a8dd150 | 28 | |
e089f05c CM |
29 | static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root |
30 | *root, struct btrfs_path *path, int level); | |
31 | static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root | |
d4dbff95 | 32 | *root, struct btrfs_key *ins_key, |
cc0c5538 | 33 | struct btrfs_path *path, int data_size, int extend); |
5f39d397 CM |
34 | static int push_node_left(struct btrfs_trans_handle *trans, |
35 | struct btrfs_root *root, struct extent_buffer *dst, | |
971a1f66 | 36 | struct extent_buffer *src, int empty); |
5f39d397 CM |
37 | static int balance_node_right(struct btrfs_trans_handle *trans, |
38 | struct btrfs_root *root, | |
39 | struct extent_buffer *dst_buf, | |
40 | struct extent_buffer *src_buf); | |
afe5fea7 TI |
41 | static void del_ptr(struct btrfs_root *root, struct btrfs_path *path, |
42 | int level, int slot); | |
5de865ee | 43 | static int tree_mod_log_free_eb(struct btrfs_fs_info *fs_info, |
f230475e | 44 | struct extent_buffer *eb); |
d97e63b6 | 45 | |
df24a2b9 | 46 | struct btrfs_path *btrfs_alloc_path(void) |
2c90e5d6 | 47 | { |
e2c89907 | 48 | return kmem_cache_zalloc(btrfs_path_cachep, GFP_NOFS); |
2c90e5d6 CM |
49 | } |
50 | ||
b4ce94de CM |
51 | /* |
52 | * set all locked nodes in the path to blocking locks. This should | |
53 | * be done before scheduling | |
54 | */ | |
55 | noinline void btrfs_set_path_blocking(struct btrfs_path *p) | |
56 | { | |
57 | int i; | |
58 | for (i = 0; i < BTRFS_MAX_LEVEL; i++) { | |
bd681513 CM |
59 | if (!p->nodes[i] || !p->locks[i]) |
60 | continue; | |
61 | btrfs_set_lock_blocking_rw(p->nodes[i], p->locks[i]); | |
62 | if (p->locks[i] == BTRFS_READ_LOCK) | |
63 | p->locks[i] = BTRFS_READ_LOCK_BLOCKING; | |
64 | else if (p->locks[i] == BTRFS_WRITE_LOCK) | |
65 | p->locks[i] = BTRFS_WRITE_LOCK_BLOCKING; | |
b4ce94de CM |
66 | } |
67 | } | |
68 | ||
69 | /* | |
70 | * reset all the locked nodes in the patch to spinning locks. | |
4008c04a CM |
71 | * |
72 | * held is used to keep lockdep happy, when lockdep is enabled | |
73 | * we set held to a blocking lock before we go around and | |
74 | * retake all the spinlocks in the path. You can safely use NULL | |
75 | * for held | |
b4ce94de | 76 | */ |
4008c04a | 77 | noinline void btrfs_clear_path_blocking(struct btrfs_path *p, |
bd681513 | 78 | struct extent_buffer *held, int held_rw) |
b4ce94de CM |
79 | { |
80 | int i; | |
4008c04a | 81 | |
bd681513 CM |
82 | if (held) { |
83 | btrfs_set_lock_blocking_rw(held, held_rw); | |
84 | if (held_rw == BTRFS_WRITE_LOCK) | |
85 | held_rw = BTRFS_WRITE_LOCK_BLOCKING; | |
86 | else if (held_rw == BTRFS_READ_LOCK) | |
87 | held_rw = BTRFS_READ_LOCK_BLOCKING; | |
88 | } | |
4008c04a | 89 | btrfs_set_path_blocking(p); |
4008c04a CM |
90 | |
91 | for (i = BTRFS_MAX_LEVEL - 1; i >= 0; i--) { | |
bd681513 CM |
92 | if (p->nodes[i] && p->locks[i]) { |
93 | btrfs_clear_lock_blocking_rw(p->nodes[i], p->locks[i]); | |
94 | if (p->locks[i] == BTRFS_WRITE_LOCK_BLOCKING) | |
95 | p->locks[i] = BTRFS_WRITE_LOCK; | |
96 | else if (p->locks[i] == BTRFS_READ_LOCK_BLOCKING) | |
97 | p->locks[i] = BTRFS_READ_LOCK; | |
98 | } | |
b4ce94de | 99 | } |
4008c04a | 100 | |
4008c04a | 101 | if (held) |
bd681513 | 102 | btrfs_clear_lock_blocking_rw(held, held_rw); |
b4ce94de CM |
103 | } |
104 | ||
d352ac68 | 105 | /* this also releases the path */ |
df24a2b9 | 106 | void btrfs_free_path(struct btrfs_path *p) |
be0e5c09 | 107 | { |
ff175d57 JJ |
108 | if (!p) |
109 | return; | |
b3b4aa74 | 110 | btrfs_release_path(p); |
df24a2b9 | 111 | kmem_cache_free(btrfs_path_cachep, p); |
be0e5c09 CM |
112 | } |
113 | ||
d352ac68 CM |
114 | /* |
115 | * path release drops references on the extent buffers in the path | |
116 | * and it drops any locks held by this path | |
117 | * | |
118 | * It is safe to call this on paths that no locks or extent buffers held. | |
119 | */ | |
b3b4aa74 | 120 | noinline void btrfs_release_path(struct btrfs_path *p) |
eb60ceac CM |
121 | { |
122 | int i; | |
a2135011 | 123 | |
234b63a0 | 124 | for (i = 0; i < BTRFS_MAX_LEVEL; i++) { |
3f157a2f | 125 | p->slots[i] = 0; |
eb60ceac | 126 | if (!p->nodes[i]) |
925baedd CM |
127 | continue; |
128 | if (p->locks[i]) { | |
bd681513 | 129 | btrfs_tree_unlock_rw(p->nodes[i], p->locks[i]); |
925baedd CM |
130 | p->locks[i] = 0; |
131 | } | |
5f39d397 | 132 | free_extent_buffer(p->nodes[i]); |
3f157a2f | 133 | p->nodes[i] = NULL; |
eb60ceac CM |
134 | } |
135 | } | |
136 | ||
d352ac68 CM |
137 | /* |
138 | * safely gets a reference on the root node of a tree. A lock | |
139 | * is not taken, so a concurrent writer may put a different node | |
140 | * at the root of the tree. See btrfs_lock_root_node for the | |
141 | * looping required. | |
142 | * | |
143 | * The extent buffer returned by this has a reference taken, so | |
144 | * it won't disappear. It may stop being the root of the tree | |
145 | * at any time because there are no locks held. | |
146 | */ | |
925baedd CM |
147 | struct extent_buffer *btrfs_root_node(struct btrfs_root *root) |
148 | { | |
149 | struct extent_buffer *eb; | |
240f62c8 | 150 | |
3083ee2e JB |
151 | while (1) { |
152 | rcu_read_lock(); | |
153 | eb = rcu_dereference(root->node); | |
154 | ||
155 | /* | |
156 | * RCU really hurts here, we could free up the root node because | |
01327610 | 157 | * it was COWed but we may not get the new root node yet so do |
3083ee2e JB |
158 | * the inc_not_zero dance and if it doesn't work then |
159 | * synchronize_rcu and try again. | |
160 | */ | |
161 | if (atomic_inc_not_zero(&eb->refs)) { | |
162 | rcu_read_unlock(); | |
163 | break; | |
164 | } | |
165 | rcu_read_unlock(); | |
166 | synchronize_rcu(); | |
167 | } | |
925baedd CM |
168 | return eb; |
169 | } | |
170 | ||
d352ac68 CM |
171 | /* loop around taking references on and locking the root node of the |
172 | * tree until you end up with a lock on the root. A locked buffer | |
173 | * is returned, with a reference held. | |
174 | */ | |
925baedd CM |
175 | struct extent_buffer *btrfs_lock_root_node(struct btrfs_root *root) |
176 | { | |
177 | struct extent_buffer *eb; | |
178 | ||
d397712b | 179 | while (1) { |
925baedd CM |
180 | eb = btrfs_root_node(root); |
181 | btrfs_tree_lock(eb); | |
240f62c8 | 182 | if (eb == root->node) |
925baedd | 183 | break; |
925baedd CM |
184 | btrfs_tree_unlock(eb); |
185 | free_extent_buffer(eb); | |
186 | } | |
187 | return eb; | |
188 | } | |
189 | ||
bd681513 CM |
190 | /* loop around taking references on and locking the root node of the |
191 | * tree until you end up with a lock on the root. A locked buffer | |
192 | * is returned, with a reference held. | |
193 | */ | |
48a3b636 | 194 | static struct extent_buffer *btrfs_read_lock_root_node(struct btrfs_root *root) |
bd681513 CM |
195 | { |
196 | struct extent_buffer *eb; | |
197 | ||
198 | while (1) { | |
199 | eb = btrfs_root_node(root); | |
200 | btrfs_tree_read_lock(eb); | |
201 | if (eb == root->node) | |
202 | break; | |
203 | btrfs_tree_read_unlock(eb); | |
204 | free_extent_buffer(eb); | |
205 | } | |
206 | return eb; | |
207 | } | |
208 | ||
d352ac68 CM |
209 | /* cowonly root (everything not a reference counted cow subvolume), just get |
210 | * put onto a simple dirty list. transaction.c walks this to make sure they | |
211 | * get properly updated on disk. | |
212 | */ | |
0b86a832 CM |
213 | static void add_root_to_dirty_list(struct btrfs_root *root) |
214 | { | |
e7070be1 JB |
215 | if (test_bit(BTRFS_ROOT_DIRTY, &root->state) || |
216 | !test_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state)) | |
217 | return; | |
218 | ||
e5846fc6 | 219 | spin_lock(&root->fs_info->trans_lock); |
e7070be1 JB |
220 | if (!test_and_set_bit(BTRFS_ROOT_DIRTY, &root->state)) { |
221 | /* Want the extent tree to be the last on the list */ | |
222 | if (root->objectid == BTRFS_EXTENT_TREE_OBJECTID) | |
223 | list_move_tail(&root->dirty_list, | |
224 | &root->fs_info->dirty_cowonly_roots); | |
225 | else | |
226 | list_move(&root->dirty_list, | |
227 | &root->fs_info->dirty_cowonly_roots); | |
0b86a832 | 228 | } |
e5846fc6 | 229 | spin_unlock(&root->fs_info->trans_lock); |
0b86a832 CM |
230 | } |
231 | ||
d352ac68 CM |
232 | /* |
233 | * used by snapshot creation to make a copy of a root for a tree with | |
234 | * a given objectid. The buffer with the new root node is returned in | |
235 | * cow_ret, and this func returns zero on success or a negative error code. | |
236 | */ | |
be20aa9d CM |
237 | int btrfs_copy_root(struct btrfs_trans_handle *trans, |
238 | struct btrfs_root *root, | |
239 | struct extent_buffer *buf, | |
240 | struct extent_buffer **cow_ret, u64 new_root_objectid) | |
241 | { | |
242 | struct extent_buffer *cow; | |
be20aa9d CM |
243 | int ret = 0; |
244 | int level; | |
5d4f98a2 | 245 | struct btrfs_disk_key disk_key; |
be20aa9d | 246 | |
27cdeb70 MX |
247 | WARN_ON(test_bit(BTRFS_ROOT_REF_COWS, &root->state) && |
248 | trans->transid != root->fs_info->running_transaction->transid); | |
249 | WARN_ON(test_bit(BTRFS_ROOT_REF_COWS, &root->state) && | |
250 | trans->transid != root->last_trans); | |
be20aa9d CM |
251 | |
252 | level = btrfs_header_level(buf); | |
5d4f98a2 YZ |
253 | if (level == 0) |
254 | btrfs_item_key(buf, &disk_key, 0); | |
255 | else | |
256 | btrfs_node_key(buf, &disk_key, 0); | |
31840ae1 | 257 | |
4d75f8a9 DS |
258 | cow = btrfs_alloc_tree_block(trans, root, 0, new_root_objectid, |
259 | &disk_key, level, buf->start, 0); | |
5d4f98a2 | 260 | if (IS_ERR(cow)) |
be20aa9d CM |
261 | return PTR_ERR(cow); |
262 | ||
263 | copy_extent_buffer(cow, buf, 0, 0, cow->len); | |
264 | btrfs_set_header_bytenr(cow, cow->start); | |
265 | btrfs_set_header_generation(cow, trans->transid); | |
5d4f98a2 YZ |
266 | btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV); |
267 | btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN | | |
268 | BTRFS_HEADER_FLAG_RELOC); | |
269 | if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID) | |
270 | btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC); | |
271 | else | |
272 | btrfs_set_header_owner(cow, new_root_objectid); | |
be20aa9d | 273 | |
0a4e5586 | 274 | write_extent_buffer(cow, root->fs_info->fsid, btrfs_header_fsid(), |
2b82032c YZ |
275 | BTRFS_FSID_SIZE); |
276 | ||
be20aa9d | 277 | WARN_ON(btrfs_header_generation(buf) > trans->transid); |
5d4f98a2 | 278 | if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID) |
e339a6b0 | 279 | ret = btrfs_inc_ref(trans, root, cow, 1); |
5d4f98a2 | 280 | else |
e339a6b0 | 281 | ret = btrfs_inc_ref(trans, root, cow, 0); |
4aec2b52 | 282 | |
be20aa9d CM |
283 | if (ret) |
284 | return ret; | |
285 | ||
286 | btrfs_mark_buffer_dirty(cow); | |
287 | *cow_ret = cow; | |
288 | return 0; | |
289 | } | |
290 | ||
bd989ba3 JS |
291 | enum mod_log_op { |
292 | MOD_LOG_KEY_REPLACE, | |
293 | MOD_LOG_KEY_ADD, | |
294 | MOD_LOG_KEY_REMOVE, | |
295 | MOD_LOG_KEY_REMOVE_WHILE_FREEING, | |
296 | MOD_LOG_KEY_REMOVE_WHILE_MOVING, | |
297 | MOD_LOG_MOVE_KEYS, | |
298 | MOD_LOG_ROOT_REPLACE, | |
299 | }; | |
300 | ||
301 | struct tree_mod_move { | |
302 | int dst_slot; | |
303 | int nr_items; | |
304 | }; | |
305 | ||
306 | struct tree_mod_root { | |
307 | u64 logical; | |
308 | u8 level; | |
309 | }; | |
310 | ||
311 | struct tree_mod_elem { | |
312 | struct rb_node node; | |
298cfd36 | 313 | u64 logical; |
097b8a7c | 314 | u64 seq; |
bd989ba3 JS |
315 | enum mod_log_op op; |
316 | ||
317 | /* this is used for MOD_LOG_KEY_* and MOD_LOG_MOVE_KEYS operations */ | |
318 | int slot; | |
319 | ||
320 | /* this is used for MOD_LOG_KEY* and MOD_LOG_ROOT_REPLACE */ | |
321 | u64 generation; | |
322 | ||
323 | /* those are used for op == MOD_LOG_KEY_{REPLACE,REMOVE} */ | |
324 | struct btrfs_disk_key key; | |
325 | u64 blockptr; | |
326 | ||
327 | /* this is used for op == MOD_LOG_MOVE_KEYS */ | |
328 | struct tree_mod_move move; | |
329 | ||
330 | /* this is used for op == MOD_LOG_ROOT_REPLACE */ | |
331 | struct tree_mod_root old_root; | |
332 | }; | |
333 | ||
097b8a7c | 334 | static inline void tree_mod_log_read_lock(struct btrfs_fs_info *fs_info) |
bd989ba3 | 335 | { |
097b8a7c | 336 | read_lock(&fs_info->tree_mod_log_lock); |
bd989ba3 JS |
337 | } |
338 | ||
097b8a7c JS |
339 | static inline void tree_mod_log_read_unlock(struct btrfs_fs_info *fs_info) |
340 | { | |
341 | read_unlock(&fs_info->tree_mod_log_lock); | |
342 | } | |
343 | ||
344 | static inline void tree_mod_log_write_lock(struct btrfs_fs_info *fs_info) | |
345 | { | |
346 | write_lock(&fs_info->tree_mod_log_lock); | |
347 | } | |
348 | ||
349 | static inline void tree_mod_log_write_unlock(struct btrfs_fs_info *fs_info) | |
350 | { | |
351 | write_unlock(&fs_info->tree_mod_log_lock); | |
352 | } | |
353 | ||
fc36ed7e | 354 | /* |
fcebe456 | 355 | * Pull a new tree mod seq number for our operation. |
fc36ed7e | 356 | */ |
fcebe456 | 357 | static inline u64 btrfs_inc_tree_mod_seq(struct btrfs_fs_info *fs_info) |
fc36ed7e JS |
358 | { |
359 | return atomic64_inc_return(&fs_info->tree_mod_seq); | |
360 | } | |
361 | ||
097b8a7c JS |
362 | /* |
363 | * This adds a new blocker to the tree mod log's blocker list if the @elem | |
364 | * passed does not already have a sequence number set. So when a caller expects | |
365 | * to record tree modifications, it should ensure to set elem->seq to zero | |
366 | * before calling btrfs_get_tree_mod_seq. | |
367 | * Returns a fresh, unused tree log modification sequence number, even if no new | |
368 | * blocker was added. | |
369 | */ | |
370 | u64 btrfs_get_tree_mod_seq(struct btrfs_fs_info *fs_info, | |
371 | struct seq_list *elem) | |
bd989ba3 | 372 | { |
097b8a7c | 373 | tree_mod_log_write_lock(fs_info); |
bd989ba3 | 374 | spin_lock(&fs_info->tree_mod_seq_lock); |
097b8a7c | 375 | if (!elem->seq) { |
fcebe456 | 376 | elem->seq = btrfs_inc_tree_mod_seq(fs_info); |
097b8a7c JS |
377 | list_add_tail(&elem->list, &fs_info->tree_mod_seq_list); |
378 | } | |
bd989ba3 | 379 | spin_unlock(&fs_info->tree_mod_seq_lock); |
097b8a7c JS |
380 | tree_mod_log_write_unlock(fs_info); |
381 | ||
fcebe456 | 382 | return elem->seq; |
bd989ba3 JS |
383 | } |
384 | ||
385 | void btrfs_put_tree_mod_seq(struct btrfs_fs_info *fs_info, | |
386 | struct seq_list *elem) | |
387 | { | |
388 | struct rb_root *tm_root; | |
389 | struct rb_node *node; | |
390 | struct rb_node *next; | |
391 | struct seq_list *cur_elem; | |
392 | struct tree_mod_elem *tm; | |
393 | u64 min_seq = (u64)-1; | |
394 | u64 seq_putting = elem->seq; | |
395 | ||
396 | if (!seq_putting) | |
397 | return; | |
398 | ||
bd989ba3 JS |
399 | spin_lock(&fs_info->tree_mod_seq_lock); |
400 | list_del(&elem->list); | |
097b8a7c | 401 | elem->seq = 0; |
bd989ba3 JS |
402 | |
403 | list_for_each_entry(cur_elem, &fs_info->tree_mod_seq_list, list) { | |
097b8a7c | 404 | if (cur_elem->seq < min_seq) { |
bd989ba3 JS |
405 | if (seq_putting > cur_elem->seq) { |
406 | /* | |
407 | * blocker with lower sequence number exists, we | |
408 | * cannot remove anything from the log | |
409 | */ | |
097b8a7c JS |
410 | spin_unlock(&fs_info->tree_mod_seq_lock); |
411 | return; | |
bd989ba3 JS |
412 | } |
413 | min_seq = cur_elem->seq; | |
414 | } | |
415 | } | |
097b8a7c JS |
416 | spin_unlock(&fs_info->tree_mod_seq_lock); |
417 | ||
bd989ba3 JS |
418 | /* |
419 | * anything that's lower than the lowest existing (read: blocked) | |
420 | * sequence number can be removed from the tree. | |
421 | */ | |
097b8a7c | 422 | tree_mod_log_write_lock(fs_info); |
bd989ba3 JS |
423 | tm_root = &fs_info->tree_mod_log; |
424 | for (node = rb_first(tm_root); node; node = next) { | |
425 | next = rb_next(node); | |
426 | tm = container_of(node, struct tree_mod_elem, node); | |
097b8a7c | 427 | if (tm->seq > min_seq) |
bd989ba3 JS |
428 | continue; |
429 | rb_erase(node, tm_root); | |
bd989ba3 JS |
430 | kfree(tm); |
431 | } | |
097b8a7c | 432 | tree_mod_log_write_unlock(fs_info); |
bd989ba3 JS |
433 | } |
434 | ||
435 | /* | |
436 | * key order of the log: | |
298cfd36 | 437 | * node/leaf start address -> sequence |
bd989ba3 | 438 | * |
298cfd36 CR |
439 | * The 'start address' is the logical address of the *new* root node |
440 | * for root replace operations, or the logical address of the affected | |
441 | * block for all other operations. | |
5de865ee FDBM |
442 | * |
443 | * Note: must be called with write lock (tree_mod_log_write_lock). | |
bd989ba3 JS |
444 | */ |
445 | static noinline int | |
446 | __tree_mod_log_insert(struct btrfs_fs_info *fs_info, struct tree_mod_elem *tm) | |
447 | { | |
448 | struct rb_root *tm_root; | |
449 | struct rb_node **new; | |
450 | struct rb_node *parent = NULL; | |
451 | struct tree_mod_elem *cur; | |
c8cc6341 JB |
452 | |
453 | BUG_ON(!tm); | |
454 | ||
fcebe456 | 455 | tm->seq = btrfs_inc_tree_mod_seq(fs_info); |
bd989ba3 | 456 | |
bd989ba3 JS |
457 | tm_root = &fs_info->tree_mod_log; |
458 | new = &tm_root->rb_node; | |
459 | while (*new) { | |
460 | cur = container_of(*new, struct tree_mod_elem, node); | |
461 | parent = *new; | |
298cfd36 | 462 | if (cur->logical < tm->logical) |
bd989ba3 | 463 | new = &((*new)->rb_left); |
298cfd36 | 464 | else if (cur->logical > tm->logical) |
bd989ba3 | 465 | new = &((*new)->rb_right); |
097b8a7c | 466 | else if (cur->seq < tm->seq) |
bd989ba3 | 467 | new = &((*new)->rb_left); |
097b8a7c | 468 | else if (cur->seq > tm->seq) |
bd989ba3 | 469 | new = &((*new)->rb_right); |
5de865ee FDBM |
470 | else |
471 | return -EEXIST; | |
bd989ba3 JS |
472 | } |
473 | ||
474 | rb_link_node(&tm->node, parent, new); | |
475 | rb_insert_color(&tm->node, tm_root); | |
5de865ee | 476 | return 0; |
bd989ba3 JS |
477 | } |
478 | ||
097b8a7c JS |
479 | /* |
480 | * Determines if logging can be omitted. Returns 1 if it can. Otherwise, it | |
481 | * returns zero with the tree_mod_log_lock acquired. The caller must hold | |
482 | * this until all tree mod log insertions are recorded in the rb tree and then | |
483 | * call tree_mod_log_write_unlock() to release. | |
484 | */ | |
e9b7fd4d JS |
485 | static inline int tree_mod_dont_log(struct btrfs_fs_info *fs_info, |
486 | struct extent_buffer *eb) { | |
487 | smp_mb(); | |
488 | if (list_empty(&(fs_info)->tree_mod_seq_list)) | |
489 | return 1; | |
097b8a7c JS |
490 | if (eb && btrfs_header_level(eb) == 0) |
491 | return 1; | |
5de865ee FDBM |
492 | |
493 | tree_mod_log_write_lock(fs_info); | |
494 | if (list_empty(&(fs_info)->tree_mod_seq_list)) { | |
495 | tree_mod_log_write_unlock(fs_info); | |
496 | return 1; | |
497 | } | |
498 | ||
e9b7fd4d JS |
499 | return 0; |
500 | } | |
501 | ||
5de865ee FDBM |
502 | /* Similar to tree_mod_dont_log, but doesn't acquire any locks. */ |
503 | static inline int tree_mod_need_log(const struct btrfs_fs_info *fs_info, | |
504 | struct extent_buffer *eb) | |
505 | { | |
506 | smp_mb(); | |
507 | if (list_empty(&(fs_info)->tree_mod_seq_list)) | |
508 | return 0; | |
509 | if (eb && btrfs_header_level(eb) == 0) | |
510 | return 0; | |
511 | ||
512 | return 1; | |
513 | } | |
514 | ||
515 | static struct tree_mod_elem * | |
516 | alloc_tree_mod_elem(struct extent_buffer *eb, int slot, | |
517 | enum mod_log_op op, gfp_t flags) | |
bd989ba3 | 518 | { |
097b8a7c | 519 | struct tree_mod_elem *tm; |
bd989ba3 | 520 | |
c8cc6341 JB |
521 | tm = kzalloc(sizeof(*tm), flags); |
522 | if (!tm) | |
5de865ee | 523 | return NULL; |
bd989ba3 | 524 | |
298cfd36 | 525 | tm->logical = eb->start; |
bd989ba3 JS |
526 | if (op != MOD_LOG_KEY_ADD) { |
527 | btrfs_node_key(eb, &tm->key, slot); | |
528 | tm->blockptr = btrfs_node_blockptr(eb, slot); | |
529 | } | |
530 | tm->op = op; | |
531 | tm->slot = slot; | |
532 | tm->generation = btrfs_node_ptr_generation(eb, slot); | |
5de865ee | 533 | RB_CLEAR_NODE(&tm->node); |
bd989ba3 | 534 | |
5de865ee | 535 | return tm; |
097b8a7c JS |
536 | } |
537 | ||
538 | static noinline int | |
c8cc6341 JB |
539 | tree_mod_log_insert_key(struct btrfs_fs_info *fs_info, |
540 | struct extent_buffer *eb, int slot, | |
541 | enum mod_log_op op, gfp_t flags) | |
097b8a7c | 542 | { |
5de865ee FDBM |
543 | struct tree_mod_elem *tm; |
544 | int ret; | |
545 | ||
546 | if (!tree_mod_need_log(fs_info, eb)) | |
547 | return 0; | |
548 | ||
549 | tm = alloc_tree_mod_elem(eb, slot, op, flags); | |
550 | if (!tm) | |
551 | return -ENOMEM; | |
552 | ||
553 | if (tree_mod_dont_log(fs_info, eb)) { | |
554 | kfree(tm); | |
097b8a7c | 555 | return 0; |
5de865ee FDBM |
556 | } |
557 | ||
558 | ret = __tree_mod_log_insert(fs_info, tm); | |
559 | tree_mod_log_write_unlock(fs_info); | |
560 | if (ret) | |
561 | kfree(tm); | |
097b8a7c | 562 | |
5de865ee | 563 | return ret; |
097b8a7c JS |
564 | } |
565 | ||
bd989ba3 JS |
566 | static noinline int |
567 | tree_mod_log_insert_move(struct btrfs_fs_info *fs_info, | |
568 | struct extent_buffer *eb, int dst_slot, int src_slot, | |
569 | int nr_items, gfp_t flags) | |
570 | { | |
5de865ee FDBM |
571 | struct tree_mod_elem *tm = NULL; |
572 | struct tree_mod_elem **tm_list = NULL; | |
573 | int ret = 0; | |
bd989ba3 | 574 | int i; |
5de865ee | 575 | int locked = 0; |
bd989ba3 | 576 | |
5de865ee | 577 | if (!tree_mod_need_log(fs_info, eb)) |
f395694c | 578 | return 0; |
bd989ba3 | 579 | |
31e818fe | 580 | tm_list = kcalloc(nr_items, sizeof(struct tree_mod_elem *), flags); |
5de865ee FDBM |
581 | if (!tm_list) |
582 | return -ENOMEM; | |
583 | ||
584 | tm = kzalloc(sizeof(*tm), flags); | |
585 | if (!tm) { | |
586 | ret = -ENOMEM; | |
587 | goto free_tms; | |
588 | } | |
589 | ||
298cfd36 | 590 | tm->logical = eb->start; |
5de865ee FDBM |
591 | tm->slot = src_slot; |
592 | tm->move.dst_slot = dst_slot; | |
593 | tm->move.nr_items = nr_items; | |
594 | tm->op = MOD_LOG_MOVE_KEYS; | |
595 | ||
596 | for (i = 0; i + dst_slot < src_slot && i < nr_items; i++) { | |
597 | tm_list[i] = alloc_tree_mod_elem(eb, i + dst_slot, | |
598 | MOD_LOG_KEY_REMOVE_WHILE_MOVING, flags); | |
599 | if (!tm_list[i]) { | |
600 | ret = -ENOMEM; | |
601 | goto free_tms; | |
602 | } | |
603 | } | |
604 | ||
605 | if (tree_mod_dont_log(fs_info, eb)) | |
606 | goto free_tms; | |
607 | locked = 1; | |
608 | ||
01763a2e JS |
609 | /* |
610 | * When we override something during the move, we log these removals. | |
611 | * This can only happen when we move towards the beginning of the | |
612 | * buffer, i.e. dst_slot < src_slot. | |
613 | */ | |
bd989ba3 | 614 | for (i = 0; i + dst_slot < src_slot && i < nr_items; i++) { |
5de865ee FDBM |
615 | ret = __tree_mod_log_insert(fs_info, tm_list[i]); |
616 | if (ret) | |
617 | goto free_tms; | |
bd989ba3 JS |
618 | } |
619 | ||
5de865ee FDBM |
620 | ret = __tree_mod_log_insert(fs_info, tm); |
621 | if (ret) | |
622 | goto free_tms; | |
623 | tree_mod_log_write_unlock(fs_info); | |
624 | kfree(tm_list); | |
f395694c | 625 | |
5de865ee FDBM |
626 | return 0; |
627 | free_tms: | |
628 | for (i = 0; i < nr_items; i++) { | |
629 | if (tm_list[i] && !RB_EMPTY_NODE(&tm_list[i]->node)) | |
630 | rb_erase(&tm_list[i]->node, &fs_info->tree_mod_log); | |
631 | kfree(tm_list[i]); | |
632 | } | |
633 | if (locked) | |
634 | tree_mod_log_write_unlock(fs_info); | |
635 | kfree(tm_list); | |
636 | kfree(tm); | |
bd989ba3 | 637 | |
5de865ee | 638 | return ret; |
bd989ba3 JS |
639 | } |
640 | ||
5de865ee FDBM |
641 | static inline int |
642 | __tree_mod_log_free_eb(struct btrfs_fs_info *fs_info, | |
643 | struct tree_mod_elem **tm_list, | |
644 | int nritems) | |
097b8a7c | 645 | { |
5de865ee | 646 | int i, j; |
097b8a7c JS |
647 | int ret; |
648 | ||
097b8a7c | 649 | for (i = nritems - 1; i >= 0; i--) { |
5de865ee FDBM |
650 | ret = __tree_mod_log_insert(fs_info, tm_list[i]); |
651 | if (ret) { | |
652 | for (j = nritems - 1; j > i; j--) | |
653 | rb_erase(&tm_list[j]->node, | |
654 | &fs_info->tree_mod_log); | |
655 | return ret; | |
656 | } | |
097b8a7c | 657 | } |
5de865ee FDBM |
658 | |
659 | return 0; | |
097b8a7c JS |
660 | } |
661 | ||
bd989ba3 JS |
662 | static noinline int |
663 | tree_mod_log_insert_root(struct btrfs_fs_info *fs_info, | |
664 | struct extent_buffer *old_root, | |
90f8d62e JS |
665 | struct extent_buffer *new_root, gfp_t flags, |
666 | int log_removal) | |
bd989ba3 | 667 | { |
5de865ee FDBM |
668 | struct tree_mod_elem *tm = NULL; |
669 | struct tree_mod_elem **tm_list = NULL; | |
670 | int nritems = 0; | |
671 | int ret = 0; | |
672 | int i; | |
bd989ba3 | 673 | |
5de865ee | 674 | if (!tree_mod_need_log(fs_info, NULL)) |
097b8a7c JS |
675 | return 0; |
676 | ||
5de865ee FDBM |
677 | if (log_removal && btrfs_header_level(old_root) > 0) { |
678 | nritems = btrfs_header_nritems(old_root); | |
31e818fe | 679 | tm_list = kcalloc(nritems, sizeof(struct tree_mod_elem *), |
5de865ee FDBM |
680 | flags); |
681 | if (!tm_list) { | |
682 | ret = -ENOMEM; | |
683 | goto free_tms; | |
684 | } | |
685 | for (i = 0; i < nritems; i++) { | |
686 | tm_list[i] = alloc_tree_mod_elem(old_root, i, | |
687 | MOD_LOG_KEY_REMOVE_WHILE_FREEING, flags); | |
688 | if (!tm_list[i]) { | |
689 | ret = -ENOMEM; | |
690 | goto free_tms; | |
691 | } | |
692 | } | |
693 | } | |
d9abbf1c | 694 | |
c8cc6341 | 695 | tm = kzalloc(sizeof(*tm), flags); |
5de865ee FDBM |
696 | if (!tm) { |
697 | ret = -ENOMEM; | |
698 | goto free_tms; | |
699 | } | |
bd989ba3 | 700 | |
298cfd36 | 701 | tm->logical = new_root->start; |
bd989ba3 JS |
702 | tm->old_root.logical = old_root->start; |
703 | tm->old_root.level = btrfs_header_level(old_root); | |
704 | tm->generation = btrfs_header_generation(old_root); | |
705 | tm->op = MOD_LOG_ROOT_REPLACE; | |
706 | ||
5de865ee FDBM |
707 | if (tree_mod_dont_log(fs_info, NULL)) |
708 | goto free_tms; | |
709 | ||
710 | if (tm_list) | |
711 | ret = __tree_mod_log_free_eb(fs_info, tm_list, nritems); | |
712 | if (!ret) | |
713 | ret = __tree_mod_log_insert(fs_info, tm); | |
714 | ||
715 | tree_mod_log_write_unlock(fs_info); | |
716 | if (ret) | |
717 | goto free_tms; | |
718 | kfree(tm_list); | |
719 | ||
720 | return ret; | |
721 | ||
722 | free_tms: | |
723 | if (tm_list) { | |
724 | for (i = 0; i < nritems; i++) | |
725 | kfree(tm_list[i]); | |
726 | kfree(tm_list); | |
727 | } | |
728 | kfree(tm); | |
729 | ||
730 | return ret; | |
bd989ba3 JS |
731 | } |
732 | ||
733 | static struct tree_mod_elem * | |
734 | __tree_mod_log_search(struct btrfs_fs_info *fs_info, u64 start, u64 min_seq, | |
735 | int smallest) | |
736 | { | |
737 | struct rb_root *tm_root; | |
738 | struct rb_node *node; | |
739 | struct tree_mod_elem *cur = NULL; | |
740 | struct tree_mod_elem *found = NULL; | |
bd989ba3 | 741 | |
097b8a7c | 742 | tree_mod_log_read_lock(fs_info); |
bd989ba3 JS |
743 | tm_root = &fs_info->tree_mod_log; |
744 | node = tm_root->rb_node; | |
745 | while (node) { | |
746 | cur = container_of(node, struct tree_mod_elem, node); | |
298cfd36 | 747 | if (cur->logical < start) { |
bd989ba3 | 748 | node = node->rb_left; |
298cfd36 | 749 | } else if (cur->logical > start) { |
bd989ba3 | 750 | node = node->rb_right; |
097b8a7c | 751 | } else if (cur->seq < min_seq) { |
bd989ba3 JS |
752 | node = node->rb_left; |
753 | } else if (!smallest) { | |
754 | /* we want the node with the highest seq */ | |
755 | if (found) | |
097b8a7c | 756 | BUG_ON(found->seq > cur->seq); |
bd989ba3 JS |
757 | found = cur; |
758 | node = node->rb_left; | |
097b8a7c | 759 | } else if (cur->seq > min_seq) { |
bd989ba3 JS |
760 | /* we want the node with the smallest seq */ |
761 | if (found) | |
097b8a7c | 762 | BUG_ON(found->seq < cur->seq); |
bd989ba3 JS |
763 | found = cur; |
764 | node = node->rb_right; | |
765 | } else { | |
766 | found = cur; | |
767 | break; | |
768 | } | |
769 | } | |
097b8a7c | 770 | tree_mod_log_read_unlock(fs_info); |
bd989ba3 JS |
771 | |
772 | return found; | |
773 | } | |
774 | ||
775 | /* | |
776 | * this returns the element from the log with the smallest time sequence | |
777 | * value that's in the log (the oldest log item). any element with a time | |
778 | * sequence lower than min_seq will be ignored. | |
779 | */ | |
780 | static struct tree_mod_elem * | |
781 | tree_mod_log_search_oldest(struct btrfs_fs_info *fs_info, u64 start, | |
782 | u64 min_seq) | |
783 | { | |
784 | return __tree_mod_log_search(fs_info, start, min_seq, 1); | |
785 | } | |
786 | ||
787 | /* | |
788 | * this returns the element from the log with the largest time sequence | |
789 | * value that's in the log (the most recent log item). any element with | |
790 | * a time sequence lower than min_seq will be ignored. | |
791 | */ | |
792 | static struct tree_mod_elem * | |
793 | tree_mod_log_search(struct btrfs_fs_info *fs_info, u64 start, u64 min_seq) | |
794 | { | |
795 | return __tree_mod_log_search(fs_info, start, min_seq, 0); | |
796 | } | |
797 | ||
5de865ee | 798 | static noinline int |
bd989ba3 JS |
799 | tree_mod_log_eb_copy(struct btrfs_fs_info *fs_info, struct extent_buffer *dst, |
800 | struct extent_buffer *src, unsigned long dst_offset, | |
90f8d62e | 801 | unsigned long src_offset, int nr_items) |
bd989ba3 | 802 | { |
5de865ee FDBM |
803 | int ret = 0; |
804 | struct tree_mod_elem **tm_list = NULL; | |
805 | struct tree_mod_elem **tm_list_add, **tm_list_rem; | |
bd989ba3 | 806 | int i; |
5de865ee | 807 | int locked = 0; |
bd989ba3 | 808 | |
5de865ee FDBM |
809 | if (!tree_mod_need_log(fs_info, NULL)) |
810 | return 0; | |
bd989ba3 | 811 | |
c8cc6341 | 812 | if (btrfs_header_level(dst) == 0 && btrfs_header_level(src) == 0) |
5de865ee FDBM |
813 | return 0; |
814 | ||
31e818fe | 815 | tm_list = kcalloc(nr_items * 2, sizeof(struct tree_mod_elem *), |
5de865ee FDBM |
816 | GFP_NOFS); |
817 | if (!tm_list) | |
818 | return -ENOMEM; | |
bd989ba3 | 819 | |
5de865ee FDBM |
820 | tm_list_add = tm_list; |
821 | tm_list_rem = tm_list + nr_items; | |
bd989ba3 | 822 | for (i = 0; i < nr_items; i++) { |
5de865ee FDBM |
823 | tm_list_rem[i] = alloc_tree_mod_elem(src, i + src_offset, |
824 | MOD_LOG_KEY_REMOVE, GFP_NOFS); | |
825 | if (!tm_list_rem[i]) { | |
826 | ret = -ENOMEM; | |
827 | goto free_tms; | |
828 | } | |
829 | ||
830 | tm_list_add[i] = alloc_tree_mod_elem(dst, i + dst_offset, | |
831 | MOD_LOG_KEY_ADD, GFP_NOFS); | |
832 | if (!tm_list_add[i]) { | |
833 | ret = -ENOMEM; | |
834 | goto free_tms; | |
835 | } | |
836 | } | |
837 | ||
838 | if (tree_mod_dont_log(fs_info, NULL)) | |
839 | goto free_tms; | |
840 | locked = 1; | |
841 | ||
842 | for (i = 0; i < nr_items; i++) { | |
843 | ret = __tree_mod_log_insert(fs_info, tm_list_rem[i]); | |
844 | if (ret) | |
845 | goto free_tms; | |
846 | ret = __tree_mod_log_insert(fs_info, tm_list_add[i]); | |
847 | if (ret) | |
848 | goto free_tms; | |
bd989ba3 | 849 | } |
5de865ee FDBM |
850 | |
851 | tree_mod_log_write_unlock(fs_info); | |
852 | kfree(tm_list); | |
853 | ||
854 | return 0; | |
855 | ||
856 | free_tms: | |
857 | for (i = 0; i < nr_items * 2; i++) { | |
858 | if (tm_list[i] && !RB_EMPTY_NODE(&tm_list[i]->node)) | |
859 | rb_erase(&tm_list[i]->node, &fs_info->tree_mod_log); | |
860 | kfree(tm_list[i]); | |
861 | } | |
862 | if (locked) | |
863 | tree_mod_log_write_unlock(fs_info); | |
864 | kfree(tm_list); | |
865 | ||
866 | return ret; | |
bd989ba3 JS |
867 | } |
868 | ||
869 | static inline void | |
870 | tree_mod_log_eb_move(struct btrfs_fs_info *fs_info, struct extent_buffer *dst, | |
871 | int dst_offset, int src_offset, int nr_items) | |
872 | { | |
873 | int ret; | |
874 | ret = tree_mod_log_insert_move(fs_info, dst, dst_offset, src_offset, | |
875 | nr_items, GFP_NOFS); | |
876 | BUG_ON(ret < 0); | |
877 | } | |
878 | ||
097b8a7c | 879 | static noinline void |
bd989ba3 | 880 | tree_mod_log_set_node_key(struct btrfs_fs_info *fs_info, |
32adf090 | 881 | struct extent_buffer *eb, int slot, int atomic) |
bd989ba3 JS |
882 | { |
883 | int ret; | |
884 | ||
78357766 | 885 | ret = tree_mod_log_insert_key(fs_info, eb, slot, |
c8cc6341 JB |
886 | MOD_LOG_KEY_REPLACE, |
887 | atomic ? GFP_ATOMIC : GFP_NOFS); | |
bd989ba3 JS |
888 | BUG_ON(ret < 0); |
889 | } | |
890 | ||
5de865ee | 891 | static noinline int |
097b8a7c | 892 | tree_mod_log_free_eb(struct btrfs_fs_info *fs_info, struct extent_buffer *eb) |
bd989ba3 | 893 | { |
5de865ee FDBM |
894 | struct tree_mod_elem **tm_list = NULL; |
895 | int nritems = 0; | |
896 | int i; | |
897 | int ret = 0; | |
898 | ||
899 | if (btrfs_header_level(eb) == 0) | |
900 | return 0; | |
901 | ||
902 | if (!tree_mod_need_log(fs_info, NULL)) | |
903 | return 0; | |
904 | ||
905 | nritems = btrfs_header_nritems(eb); | |
31e818fe | 906 | tm_list = kcalloc(nritems, sizeof(struct tree_mod_elem *), GFP_NOFS); |
5de865ee FDBM |
907 | if (!tm_list) |
908 | return -ENOMEM; | |
909 | ||
910 | for (i = 0; i < nritems; i++) { | |
911 | tm_list[i] = alloc_tree_mod_elem(eb, i, | |
912 | MOD_LOG_KEY_REMOVE_WHILE_FREEING, GFP_NOFS); | |
913 | if (!tm_list[i]) { | |
914 | ret = -ENOMEM; | |
915 | goto free_tms; | |
916 | } | |
917 | } | |
918 | ||
e9b7fd4d | 919 | if (tree_mod_dont_log(fs_info, eb)) |
5de865ee FDBM |
920 | goto free_tms; |
921 | ||
922 | ret = __tree_mod_log_free_eb(fs_info, tm_list, nritems); | |
923 | tree_mod_log_write_unlock(fs_info); | |
924 | if (ret) | |
925 | goto free_tms; | |
926 | kfree(tm_list); | |
927 | ||
928 | return 0; | |
929 | ||
930 | free_tms: | |
931 | for (i = 0; i < nritems; i++) | |
932 | kfree(tm_list[i]); | |
933 | kfree(tm_list); | |
934 | ||
935 | return ret; | |
bd989ba3 JS |
936 | } |
937 | ||
097b8a7c | 938 | static noinline void |
bd989ba3 | 939 | tree_mod_log_set_root_pointer(struct btrfs_root *root, |
90f8d62e JS |
940 | struct extent_buffer *new_root_node, |
941 | int log_removal) | |
bd989ba3 JS |
942 | { |
943 | int ret; | |
bd989ba3 | 944 | ret = tree_mod_log_insert_root(root->fs_info, root->node, |
90f8d62e | 945 | new_root_node, GFP_NOFS, log_removal); |
bd989ba3 JS |
946 | BUG_ON(ret < 0); |
947 | } | |
948 | ||
5d4f98a2 YZ |
949 | /* |
950 | * check if the tree block can be shared by multiple trees | |
951 | */ | |
952 | int btrfs_block_can_be_shared(struct btrfs_root *root, | |
953 | struct extent_buffer *buf) | |
954 | { | |
955 | /* | |
01327610 | 956 | * Tree blocks not in reference counted trees and tree roots |
5d4f98a2 YZ |
957 | * are never shared. If a block was allocated after the last |
958 | * snapshot and the block was not allocated by tree relocation, | |
959 | * we know the block is not shared. | |
960 | */ | |
27cdeb70 | 961 | if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) && |
5d4f98a2 YZ |
962 | buf != root->node && buf != root->commit_root && |
963 | (btrfs_header_generation(buf) <= | |
964 | btrfs_root_last_snapshot(&root->root_item) || | |
965 | btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC))) | |
966 | return 1; | |
967 | #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 | |
27cdeb70 | 968 | if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) && |
5d4f98a2 YZ |
969 | btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) |
970 | return 1; | |
971 | #endif | |
972 | return 0; | |
973 | } | |
974 | ||
975 | static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans, | |
976 | struct btrfs_root *root, | |
977 | struct extent_buffer *buf, | |
f0486c68 YZ |
978 | struct extent_buffer *cow, |
979 | int *last_ref) | |
5d4f98a2 YZ |
980 | { |
981 | u64 refs; | |
982 | u64 owner; | |
983 | u64 flags; | |
984 | u64 new_flags = 0; | |
985 | int ret; | |
986 | ||
987 | /* | |
988 | * Backrefs update rules: | |
989 | * | |
990 | * Always use full backrefs for extent pointers in tree block | |
991 | * allocated by tree relocation. | |
992 | * | |
993 | * If a shared tree block is no longer referenced by its owner | |
994 | * tree (btrfs_header_owner(buf) == root->root_key.objectid), | |
995 | * use full backrefs for extent pointers in tree block. | |
996 | * | |
997 | * If a tree block is been relocating | |
998 | * (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID), | |
999 | * use full backrefs for extent pointers in tree block. | |
1000 | * The reason for this is some operations (such as drop tree) | |
1001 | * are only allowed for blocks use full backrefs. | |
1002 | */ | |
1003 | ||
1004 | if (btrfs_block_can_be_shared(root, buf)) { | |
1005 | ret = btrfs_lookup_extent_info(trans, root, buf->start, | |
3173a18f JB |
1006 | btrfs_header_level(buf), 1, |
1007 | &refs, &flags); | |
be1a5564 MF |
1008 | if (ret) |
1009 | return ret; | |
e5df9573 MF |
1010 | if (refs == 0) { |
1011 | ret = -EROFS; | |
34d97007 | 1012 | btrfs_handle_fs_error(root->fs_info, ret, NULL); |
e5df9573 MF |
1013 | return ret; |
1014 | } | |
5d4f98a2 YZ |
1015 | } else { |
1016 | refs = 1; | |
1017 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID || | |
1018 | btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) | |
1019 | flags = BTRFS_BLOCK_FLAG_FULL_BACKREF; | |
1020 | else | |
1021 | flags = 0; | |
1022 | } | |
1023 | ||
1024 | owner = btrfs_header_owner(buf); | |
1025 | BUG_ON(owner == BTRFS_TREE_RELOC_OBJECTID && | |
1026 | !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)); | |
1027 | ||
1028 | if (refs > 1) { | |
1029 | if ((owner == root->root_key.objectid || | |
1030 | root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) && | |
1031 | !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)) { | |
e339a6b0 | 1032 | ret = btrfs_inc_ref(trans, root, buf, 1); |
79787eaa | 1033 | BUG_ON(ret); /* -ENOMEM */ |
5d4f98a2 YZ |
1034 | |
1035 | if (root->root_key.objectid == | |
1036 | BTRFS_TREE_RELOC_OBJECTID) { | |
e339a6b0 | 1037 | ret = btrfs_dec_ref(trans, root, buf, 0); |
79787eaa | 1038 | BUG_ON(ret); /* -ENOMEM */ |
e339a6b0 | 1039 | ret = btrfs_inc_ref(trans, root, cow, 1); |
79787eaa | 1040 | BUG_ON(ret); /* -ENOMEM */ |
5d4f98a2 YZ |
1041 | } |
1042 | new_flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF; | |
1043 | } else { | |
1044 | ||
1045 | if (root->root_key.objectid == | |
1046 | BTRFS_TREE_RELOC_OBJECTID) | |
e339a6b0 | 1047 | ret = btrfs_inc_ref(trans, root, cow, 1); |
5d4f98a2 | 1048 | else |
e339a6b0 | 1049 | ret = btrfs_inc_ref(trans, root, cow, 0); |
79787eaa | 1050 | BUG_ON(ret); /* -ENOMEM */ |
5d4f98a2 YZ |
1051 | } |
1052 | if (new_flags != 0) { | |
b1c79e09 JB |
1053 | int level = btrfs_header_level(buf); |
1054 | ||
5d4f98a2 YZ |
1055 | ret = btrfs_set_disk_extent_flags(trans, root, |
1056 | buf->start, | |
1057 | buf->len, | |
b1c79e09 | 1058 | new_flags, level, 0); |
be1a5564 MF |
1059 | if (ret) |
1060 | return ret; | |
5d4f98a2 YZ |
1061 | } |
1062 | } else { | |
1063 | if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF) { | |
1064 | if (root->root_key.objectid == | |
1065 | BTRFS_TREE_RELOC_OBJECTID) | |
e339a6b0 | 1066 | ret = btrfs_inc_ref(trans, root, cow, 1); |
5d4f98a2 | 1067 | else |
e339a6b0 | 1068 | ret = btrfs_inc_ref(trans, root, cow, 0); |
79787eaa | 1069 | BUG_ON(ret); /* -ENOMEM */ |
e339a6b0 | 1070 | ret = btrfs_dec_ref(trans, root, buf, 1); |
79787eaa | 1071 | BUG_ON(ret); /* -ENOMEM */ |
5d4f98a2 | 1072 | } |
01d58472 | 1073 | clean_tree_block(trans, root->fs_info, buf); |
f0486c68 | 1074 | *last_ref = 1; |
5d4f98a2 YZ |
1075 | } |
1076 | return 0; | |
1077 | } | |
1078 | ||
d352ac68 | 1079 | /* |
d397712b CM |
1080 | * does the dirty work in cow of a single block. The parent block (if |
1081 | * supplied) is updated to point to the new cow copy. The new buffer is marked | |
1082 | * dirty and returned locked. If you modify the block it needs to be marked | |
1083 | * dirty again. | |
d352ac68 CM |
1084 | * |
1085 | * search_start -- an allocation hint for the new block | |
1086 | * | |
d397712b CM |
1087 | * empty_size -- a hint that you plan on doing more cow. This is the size in |
1088 | * bytes the allocator should try to find free next to the block it returns. | |
1089 | * This is just a hint and may be ignored by the allocator. | |
d352ac68 | 1090 | */ |
d397712b | 1091 | static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans, |
5f39d397 CM |
1092 | struct btrfs_root *root, |
1093 | struct extent_buffer *buf, | |
1094 | struct extent_buffer *parent, int parent_slot, | |
1095 | struct extent_buffer **cow_ret, | |
9fa8cfe7 | 1096 | u64 search_start, u64 empty_size) |
02217ed2 | 1097 | { |
5d4f98a2 | 1098 | struct btrfs_disk_key disk_key; |
5f39d397 | 1099 | struct extent_buffer *cow; |
be1a5564 | 1100 | int level, ret; |
f0486c68 | 1101 | int last_ref = 0; |
925baedd | 1102 | int unlock_orig = 0; |
0f5053eb | 1103 | u64 parent_start = 0; |
7bb86316 | 1104 | |
925baedd CM |
1105 | if (*cow_ret == buf) |
1106 | unlock_orig = 1; | |
1107 | ||
b9447ef8 | 1108 | btrfs_assert_tree_locked(buf); |
925baedd | 1109 | |
27cdeb70 MX |
1110 | WARN_ON(test_bit(BTRFS_ROOT_REF_COWS, &root->state) && |
1111 | trans->transid != root->fs_info->running_transaction->transid); | |
1112 | WARN_ON(test_bit(BTRFS_ROOT_REF_COWS, &root->state) && | |
1113 | trans->transid != root->last_trans); | |
5f39d397 | 1114 | |
7bb86316 | 1115 | level = btrfs_header_level(buf); |
31840ae1 | 1116 | |
5d4f98a2 YZ |
1117 | if (level == 0) |
1118 | btrfs_item_key(buf, &disk_key, 0); | |
1119 | else | |
1120 | btrfs_node_key(buf, &disk_key, 0); | |
1121 | ||
0f5053eb GR |
1122 | if ((root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) && parent) |
1123 | parent_start = parent->start; | |
5d4f98a2 | 1124 | |
4d75f8a9 DS |
1125 | cow = btrfs_alloc_tree_block(trans, root, parent_start, |
1126 | root->root_key.objectid, &disk_key, level, | |
1127 | search_start, empty_size); | |
54aa1f4d CM |
1128 | if (IS_ERR(cow)) |
1129 | return PTR_ERR(cow); | |
6702ed49 | 1130 | |
b4ce94de CM |
1131 | /* cow is set to blocking by btrfs_init_new_buffer */ |
1132 | ||
5f39d397 | 1133 | copy_extent_buffer(cow, buf, 0, 0, cow->len); |
db94535d | 1134 | btrfs_set_header_bytenr(cow, cow->start); |
5f39d397 | 1135 | btrfs_set_header_generation(cow, trans->transid); |
5d4f98a2 YZ |
1136 | btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV); |
1137 | btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN | | |
1138 | BTRFS_HEADER_FLAG_RELOC); | |
1139 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) | |
1140 | btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC); | |
1141 | else | |
1142 | btrfs_set_header_owner(cow, root->root_key.objectid); | |
6702ed49 | 1143 | |
0a4e5586 | 1144 | write_extent_buffer(cow, root->fs_info->fsid, btrfs_header_fsid(), |
2b82032c YZ |
1145 | BTRFS_FSID_SIZE); |
1146 | ||
be1a5564 | 1147 | ret = update_ref_for_cow(trans, root, buf, cow, &last_ref); |
b68dc2a9 | 1148 | if (ret) { |
66642832 | 1149 | btrfs_abort_transaction(trans, ret); |
b68dc2a9 MF |
1150 | return ret; |
1151 | } | |
1a40e23b | 1152 | |
27cdeb70 | 1153 | if (test_bit(BTRFS_ROOT_REF_COWS, &root->state)) { |
83d4cfd4 | 1154 | ret = btrfs_reloc_cow_block(trans, root, buf, cow); |
93314e3b | 1155 | if (ret) { |
66642832 | 1156 | btrfs_abort_transaction(trans, ret); |
83d4cfd4 | 1157 | return ret; |
93314e3b | 1158 | } |
83d4cfd4 | 1159 | } |
3fd0a558 | 1160 | |
02217ed2 | 1161 | if (buf == root->node) { |
925baedd | 1162 | WARN_ON(parent && parent != buf); |
5d4f98a2 YZ |
1163 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID || |
1164 | btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) | |
1165 | parent_start = buf->start; | |
925baedd | 1166 | |
5f39d397 | 1167 | extent_buffer_get(cow); |
90f8d62e | 1168 | tree_mod_log_set_root_pointer(root, cow, 1); |
240f62c8 | 1169 | rcu_assign_pointer(root->node, cow); |
925baedd | 1170 | |
f0486c68 | 1171 | btrfs_free_tree_block(trans, root, buf, parent_start, |
5581a51a | 1172 | last_ref); |
5f39d397 | 1173 | free_extent_buffer(buf); |
0b86a832 | 1174 | add_root_to_dirty_list(root); |
02217ed2 | 1175 | } else { |
5d4f98a2 | 1176 | WARN_ON(trans->transid != btrfs_header_generation(parent)); |
f230475e | 1177 | tree_mod_log_insert_key(root->fs_info, parent, parent_slot, |
c8cc6341 | 1178 | MOD_LOG_KEY_REPLACE, GFP_NOFS); |
5f39d397 | 1179 | btrfs_set_node_blockptr(parent, parent_slot, |
db94535d | 1180 | cow->start); |
74493f7a CM |
1181 | btrfs_set_node_ptr_generation(parent, parent_slot, |
1182 | trans->transid); | |
d6025579 | 1183 | btrfs_mark_buffer_dirty(parent); |
5de865ee FDBM |
1184 | if (last_ref) { |
1185 | ret = tree_mod_log_free_eb(root->fs_info, buf); | |
1186 | if (ret) { | |
66642832 | 1187 | btrfs_abort_transaction(trans, ret); |
5de865ee FDBM |
1188 | return ret; |
1189 | } | |
1190 | } | |
f0486c68 | 1191 | btrfs_free_tree_block(trans, root, buf, parent_start, |
5581a51a | 1192 | last_ref); |
02217ed2 | 1193 | } |
925baedd CM |
1194 | if (unlock_orig) |
1195 | btrfs_tree_unlock(buf); | |
3083ee2e | 1196 | free_extent_buffer_stale(buf); |
ccd467d6 | 1197 | btrfs_mark_buffer_dirty(cow); |
2c90e5d6 | 1198 | *cow_ret = cow; |
02217ed2 CM |
1199 | return 0; |
1200 | } | |
1201 | ||
5d9e75c4 JS |
1202 | /* |
1203 | * returns the logical address of the oldest predecessor of the given root. | |
1204 | * entries older than time_seq are ignored. | |
1205 | */ | |
1206 | static struct tree_mod_elem * | |
1207 | __tree_mod_log_oldest_root(struct btrfs_fs_info *fs_info, | |
30b0463a | 1208 | struct extent_buffer *eb_root, u64 time_seq) |
5d9e75c4 JS |
1209 | { |
1210 | struct tree_mod_elem *tm; | |
1211 | struct tree_mod_elem *found = NULL; | |
30b0463a | 1212 | u64 root_logical = eb_root->start; |
5d9e75c4 JS |
1213 | int looped = 0; |
1214 | ||
1215 | if (!time_seq) | |
35a3621b | 1216 | return NULL; |
5d9e75c4 JS |
1217 | |
1218 | /* | |
298cfd36 CR |
1219 | * the very last operation that's logged for a root is the |
1220 | * replacement operation (if it is replaced at all). this has | |
1221 | * the logical address of the *new* root, making it the very | |
1222 | * first operation that's logged for this root. | |
5d9e75c4 JS |
1223 | */ |
1224 | while (1) { | |
1225 | tm = tree_mod_log_search_oldest(fs_info, root_logical, | |
1226 | time_seq); | |
1227 | if (!looped && !tm) | |
35a3621b | 1228 | return NULL; |
5d9e75c4 | 1229 | /* |
28da9fb4 JS |
1230 | * if there are no tree operation for the oldest root, we simply |
1231 | * return it. this should only happen if that (old) root is at | |
1232 | * level 0. | |
5d9e75c4 | 1233 | */ |
28da9fb4 JS |
1234 | if (!tm) |
1235 | break; | |
5d9e75c4 | 1236 | |
28da9fb4 JS |
1237 | /* |
1238 | * if there's an operation that's not a root replacement, we | |
1239 | * found the oldest version of our root. normally, we'll find a | |
1240 | * MOD_LOG_KEY_REMOVE_WHILE_FREEING operation here. | |
1241 | */ | |
5d9e75c4 JS |
1242 | if (tm->op != MOD_LOG_ROOT_REPLACE) |
1243 | break; | |
1244 | ||
1245 | found = tm; | |
1246 | root_logical = tm->old_root.logical; | |
5d9e75c4 JS |
1247 | looped = 1; |
1248 | } | |
1249 | ||
a95236d9 JS |
1250 | /* if there's no old root to return, return what we found instead */ |
1251 | if (!found) | |
1252 | found = tm; | |
1253 | ||
5d9e75c4 JS |
1254 | return found; |
1255 | } | |
1256 | ||
1257 | /* | |
1258 | * tm is a pointer to the first operation to rewind within eb. then, all | |
01327610 | 1259 | * previous operations will be rewound (until we reach something older than |
5d9e75c4 JS |
1260 | * time_seq). |
1261 | */ | |
1262 | static void | |
f1ca7e98 JB |
1263 | __tree_mod_log_rewind(struct btrfs_fs_info *fs_info, struct extent_buffer *eb, |
1264 | u64 time_seq, struct tree_mod_elem *first_tm) | |
5d9e75c4 JS |
1265 | { |
1266 | u32 n; | |
1267 | struct rb_node *next; | |
1268 | struct tree_mod_elem *tm = first_tm; | |
1269 | unsigned long o_dst; | |
1270 | unsigned long o_src; | |
1271 | unsigned long p_size = sizeof(struct btrfs_key_ptr); | |
1272 | ||
1273 | n = btrfs_header_nritems(eb); | |
f1ca7e98 | 1274 | tree_mod_log_read_lock(fs_info); |
097b8a7c | 1275 | while (tm && tm->seq >= time_seq) { |
5d9e75c4 JS |
1276 | /* |
1277 | * all the operations are recorded with the operator used for | |
1278 | * the modification. as we're going backwards, we do the | |
1279 | * opposite of each operation here. | |
1280 | */ | |
1281 | switch (tm->op) { | |
1282 | case MOD_LOG_KEY_REMOVE_WHILE_FREEING: | |
1283 | BUG_ON(tm->slot < n); | |
1c697d4a | 1284 | /* Fallthrough */ |
95c80bb1 | 1285 | case MOD_LOG_KEY_REMOVE_WHILE_MOVING: |
4c3e6969 | 1286 | case MOD_LOG_KEY_REMOVE: |
5d9e75c4 JS |
1287 | btrfs_set_node_key(eb, &tm->key, tm->slot); |
1288 | btrfs_set_node_blockptr(eb, tm->slot, tm->blockptr); | |
1289 | btrfs_set_node_ptr_generation(eb, tm->slot, | |
1290 | tm->generation); | |
4c3e6969 | 1291 | n++; |
5d9e75c4 JS |
1292 | break; |
1293 | case MOD_LOG_KEY_REPLACE: | |
1294 | BUG_ON(tm->slot >= n); | |
1295 | btrfs_set_node_key(eb, &tm->key, tm->slot); | |
1296 | btrfs_set_node_blockptr(eb, tm->slot, tm->blockptr); | |
1297 | btrfs_set_node_ptr_generation(eb, tm->slot, | |
1298 | tm->generation); | |
1299 | break; | |
1300 | case MOD_LOG_KEY_ADD: | |
19956c7e | 1301 | /* if a move operation is needed it's in the log */ |
5d9e75c4 JS |
1302 | n--; |
1303 | break; | |
1304 | case MOD_LOG_MOVE_KEYS: | |
c3193108 JS |
1305 | o_dst = btrfs_node_key_ptr_offset(tm->slot); |
1306 | o_src = btrfs_node_key_ptr_offset(tm->move.dst_slot); | |
1307 | memmove_extent_buffer(eb, o_dst, o_src, | |
5d9e75c4 JS |
1308 | tm->move.nr_items * p_size); |
1309 | break; | |
1310 | case MOD_LOG_ROOT_REPLACE: | |
1311 | /* | |
1312 | * this operation is special. for roots, this must be | |
1313 | * handled explicitly before rewinding. | |
1314 | * for non-roots, this operation may exist if the node | |
1315 | * was a root: root A -> child B; then A gets empty and | |
1316 | * B is promoted to the new root. in the mod log, we'll | |
1317 | * have a root-replace operation for B, a tree block | |
1318 | * that is no root. we simply ignore that operation. | |
1319 | */ | |
1320 | break; | |
1321 | } | |
1322 | next = rb_next(&tm->node); | |
1323 | if (!next) | |
1324 | break; | |
1325 | tm = container_of(next, struct tree_mod_elem, node); | |
298cfd36 | 1326 | if (tm->logical != first_tm->logical) |
5d9e75c4 JS |
1327 | break; |
1328 | } | |
f1ca7e98 | 1329 | tree_mod_log_read_unlock(fs_info); |
5d9e75c4 JS |
1330 | btrfs_set_header_nritems(eb, n); |
1331 | } | |
1332 | ||
47fb091f | 1333 | /* |
01327610 | 1334 | * Called with eb read locked. If the buffer cannot be rewound, the same buffer |
47fb091f JS |
1335 | * is returned. If rewind operations happen, a fresh buffer is returned. The |
1336 | * returned buffer is always read-locked. If the returned buffer is not the | |
1337 | * input buffer, the lock on the input buffer is released and the input buffer | |
1338 | * is freed (its refcount is decremented). | |
1339 | */ | |
5d9e75c4 | 1340 | static struct extent_buffer * |
9ec72677 JB |
1341 | tree_mod_log_rewind(struct btrfs_fs_info *fs_info, struct btrfs_path *path, |
1342 | struct extent_buffer *eb, u64 time_seq) | |
5d9e75c4 JS |
1343 | { |
1344 | struct extent_buffer *eb_rewin; | |
1345 | struct tree_mod_elem *tm; | |
1346 | ||
1347 | if (!time_seq) | |
1348 | return eb; | |
1349 | ||
1350 | if (btrfs_header_level(eb) == 0) | |
1351 | return eb; | |
1352 | ||
1353 | tm = tree_mod_log_search(fs_info, eb->start, time_seq); | |
1354 | if (!tm) | |
1355 | return eb; | |
1356 | ||
9ec72677 JB |
1357 | btrfs_set_path_blocking(path); |
1358 | btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK); | |
1359 | ||
5d9e75c4 JS |
1360 | if (tm->op == MOD_LOG_KEY_REMOVE_WHILE_FREEING) { |
1361 | BUG_ON(tm->slot != 0); | |
b9ef22de FX |
1362 | eb_rewin = alloc_dummy_extent_buffer(fs_info, eb->start, |
1363 | eb->len); | |
db7f3436 | 1364 | if (!eb_rewin) { |
9ec72677 | 1365 | btrfs_tree_read_unlock_blocking(eb); |
db7f3436 JB |
1366 | free_extent_buffer(eb); |
1367 | return NULL; | |
1368 | } | |
5d9e75c4 JS |
1369 | btrfs_set_header_bytenr(eb_rewin, eb->start); |
1370 | btrfs_set_header_backref_rev(eb_rewin, | |
1371 | btrfs_header_backref_rev(eb)); | |
1372 | btrfs_set_header_owner(eb_rewin, btrfs_header_owner(eb)); | |
c3193108 | 1373 | btrfs_set_header_level(eb_rewin, btrfs_header_level(eb)); |
5d9e75c4 JS |
1374 | } else { |
1375 | eb_rewin = btrfs_clone_extent_buffer(eb); | |
db7f3436 | 1376 | if (!eb_rewin) { |
9ec72677 | 1377 | btrfs_tree_read_unlock_blocking(eb); |
db7f3436 JB |
1378 | free_extent_buffer(eb); |
1379 | return NULL; | |
1380 | } | |
5d9e75c4 JS |
1381 | } |
1382 | ||
9ec72677 JB |
1383 | btrfs_clear_path_blocking(path, NULL, BTRFS_READ_LOCK); |
1384 | btrfs_tree_read_unlock_blocking(eb); | |
5d9e75c4 JS |
1385 | free_extent_buffer(eb); |
1386 | ||
47fb091f JS |
1387 | extent_buffer_get(eb_rewin); |
1388 | btrfs_tree_read_lock(eb_rewin); | |
f1ca7e98 | 1389 | __tree_mod_log_rewind(fs_info, eb_rewin, time_seq, tm); |
57911b8b | 1390 | WARN_ON(btrfs_header_nritems(eb_rewin) > |
2a745b14 | 1391 | BTRFS_NODEPTRS_PER_BLOCK(fs_info->tree_root)); |
5d9e75c4 JS |
1392 | |
1393 | return eb_rewin; | |
1394 | } | |
1395 | ||
8ba97a15 JS |
1396 | /* |
1397 | * get_old_root() rewinds the state of @root's root node to the given @time_seq | |
1398 | * value. If there are no changes, the current root->root_node is returned. If | |
1399 | * anything changed in between, there's a fresh buffer allocated on which the | |
1400 | * rewind operations are done. In any case, the returned buffer is read locked. | |
1401 | * Returns NULL on error (with no locks held). | |
1402 | */ | |
5d9e75c4 JS |
1403 | static inline struct extent_buffer * |
1404 | get_old_root(struct btrfs_root *root, u64 time_seq) | |
1405 | { | |
1406 | struct tree_mod_elem *tm; | |
30b0463a JS |
1407 | struct extent_buffer *eb = NULL; |
1408 | struct extent_buffer *eb_root; | |
7bfdcf7f | 1409 | struct extent_buffer *old; |
a95236d9 | 1410 | struct tree_mod_root *old_root = NULL; |
4325edd0 | 1411 | u64 old_generation = 0; |
a95236d9 | 1412 | u64 logical; |
5d9e75c4 | 1413 | |
30b0463a JS |
1414 | eb_root = btrfs_read_lock_root_node(root); |
1415 | tm = __tree_mod_log_oldest_root(root->fs_info, eb_root, time_seq); | |
5d9e75c4 | 1416 | if (!tm) |
30b0463a | 1417 | return eb_root; |
5d9e75c4 | 1418 | |
a95236d9 JS |
1419 | if (tm->op == MOD_LOG_ROOT_REPLACE) { |
1420 | old_root = &tm->old_root; | |
1421 | old_generation = tm->generation; | |
1422 | logical = old_root->logical; | |
1423 | } else { | |
30b0463a | 1424 | logical = eb_root->start; |
a95236d9 | 1425 | } |
5d9e75c4 | 1426 | |
a95236d9 | 1427 | tm = tree_mod_log_search(root->fs_info, logical, time_seq); |
834328a8 | 1428 | if (old_root && tm && tm->op != MOD_LOG_KEY_REMOVE_WHILE_FREEING) { |
30b0463a JS |
1429 | btrfs_tree_read_unlock(eb_root); |
1430 | free_extent_buffer(eb_root); | |
ce86cd59 | 1431 | old = read_tree_block(root, logical, 0); |
64c043de LB |
1432 | if (WARN_ON(IS_ERR(old) || !extent_buffer_uptodate(old))) { |
1433 | if (!IS_ERR(old)) | |
1434 | free_extent_buffer(old); | |
efe120a0 FH |
1435 | btrfs_warn(root->fs_info, |
1436 | "failed to read tree block %llu from get_old_root", logical); | |
834328a8 | 1437 | } else { |
7bfdcf7f LB |
1438 | eb = btrfs_clone_extent_buffer(old); |
1439 | free_extent_buffer(old); | |
834328a8 JS |
1440 | } |
1441 | } else if (old_root) { | |
30b0463a JS |
1442 | btrfs_tree_read_unlock(eb_root); |
1443 | free_extent_buffer(eb_root); | |
b9ef22de FX |
1444 | eb = alloc_dummy_extent_buffer(root->fs_info, logical, |
1445 | root->nodesize); | |
834328a8 | 1446 | } else { |
9ec72677 | 1447 | btrfs_set_lock_blocking_rw(eb_root, BTRFS_READ_LOCK); |
30b0463a | 1448 | eb = btrfs_clone_extent_buffer(eb_root); |
9ec72677 | 1449 | btrfs_tree_read_unlock_blocking(eb_root); |
30b0463a | 1450 | free_extent_buffer(eb_root); |
834328a8 JS |
1451 | } |
1452 | ||
8ba97a15 JS |
1453 | if (!eb) |
1454 | return NULL; | |
d6381084 | 1455 | extent_buffer_get(eb); |
8ba97a15 | 1456 | btrfs_tree_read_lock(eb); |
a95236d9 | 1457 | if (old_root) { |
5d9e75c4 JS |
1458 | btrfs_set_header_bytenr(eb, eb->start); |
1459 | btrfs_set_header_backref_rev(eb, BTRFS_MIXED_BACKREF_REV); | |
30b0463a | 1460 | btrfs_set_header_owner(eb, btrfs_header_owner(eb_root)); |
a95236d9 JS |
1461 | btrfs_set_header_level(eb, old_root->level); |
1462 | btrfs_set_header_generation(eb, old_generation); | |
5d9e75c4 | 1463 | } |
28da9fb4 | 1464 | if (tm) |
f1ca7e98 | 1465 | __tree_mod_log_rewind(root->fs_info, eb, time_seq, tm); |
28da9fb4 JS |
1466 | else |
1467 | WARN_ON(btrfs_header_level(eb) != 0); | |
57911b8b | 1468 | WARN_ON(btrfs_header_nritems(eb) > BTRFS_NODEPTRS_PER_BLOCK(root)); |
5d9e75c4 JS |
1469 | |
1470 | return eb; | |
1471 | } | |
1472 | ||
5b6602e7 JS |
1473 | int btrfs_old_root_level(struct btrfs_root *root, u64 time_seq) |
1474 | { | |
1475 | struct tree_mod_elem *tm; | |
1476 | int level; | |
30b0463a | 1477 | struct extent_buffer *eb_root = btrfs_root_node(root); |
5b6602e7 | 1478 | |
30b0463a | 1479 | tm = __tree_mod_log_oldest_root(root->fs_info, eb_root, time_seq); |
5b6602e7 JS |
1480 | if (tm && tm->op == MOD_LOG_ROOT_REPLACE) { |
1481 | level = tm->old_root.level; | |
1482 | } else { | |
30b0463a | 1483 | level = btrfs_header_level(eb_root); |
5b6602e7 | 1484 | } |
30b0463a | 1485 | free_extent_buffer(eb_root); |
5b6602e7 JS |
1486 | |
1487 | return level; | |
1488 | } | |
1489 | ||
5d4f98a2 YZ |
1490 | static inline int should_cow_block(struct btrfs_trans_handle *trans, |
1491 | struct btrfs_root *root, | |
1492 | struct extent_buffer *buf) | |
1493 | { | |
f5ee5c9a | 1494 | if (btrfs_is_testing(root->fs_info)) |
faa2dbf0 | 1495 | return 0; |
fccb84c9 | 1496 | |
f1ebcc74 LB |
1497 | /* ensure we can see the force_cow */ |
1498 | smp_rmb(); | |
1499 | ||
1500 | /* | |
1501 | * We do not need to cow a block if | |
1502 | * 1) this block is not created or changed in this transaction; | |
1503 | * 2) this block does not belong to TREE_RELOC tree; | |
1504 | * 3) the root is not forced COW. | |
1505 | * | |
1506 | * What is forced COW: | |
01327610 | 1507 | * when we create snapshot during committing the transaction, |
f1ebcc74 LB |
1508 | * after we've finished coping src root, we must COW the shared |
1509 | * block to ensure the metadata consistency. | |
1510 | */ | |
5d4f98a2 YZ |
1511 | if (btrfs_header_generation(buf) == trans->transid && |
1512 | !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN) && | |
1513 | !(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID && | |
f1ebcc74 | 1514 | btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC)) && |
27cdeb70 | 1515 | !test_bit(BTRFS_ROOT_FORCE_COW, &root->state)) |
5d4f98a2 YZ |
1516 | return 0; |
1517 | return 1; | |
1518 | } | |
1519 | ||
d352ac68 CM |
1520 | /* |
1521 | * cows a single block, see __btrfs_cow_block for the real work. | |
01327610 | 1522 | * This version of it has extra checks so that a block isn't COWed more than |
d352ac68 CM |
1523 | * once per transaction, as long as it hasn't been written yet |
1524 | */ | |
d397712b | 1525 | noinline int btrfs_cow_block(struct btrfs_trans_handle *trans, |
5f39d397 CM |
1526 | struct btrfs_root *root, struct extent_buffer *buf, |
1527 | struct extent_buffer *parent, int parent_slot, | |
9fa8cfe7 | 1528 | struct extent_buffer **cow_ret) |
6702ed49 CM |
1529 | { |
1530 | u64 search_start; | |
f510cfec | 1531 | int ret; |
dc17ff8f | 1532 | |
31b1a2bd JL |
1533 | if (trans->transaction != root->fs_info->running_transaction) |
1534 | WARN(1, KERN_CRIT "trans %llu running %llu\n", | |
c1c9ff7c | 1535 | trans->transid, |
6702ed49 | 1536 | root->fs_info->running_transaction->transid); |
31b1a2bd JL |
1537 | |
1538 | if (trans->transid != root->fs_info->generation) | |
1539 | WARN(1, KERN_CRIT "trans %llu running %llu\n", | |
c1c9ff7c | 1540 | trans->transid, root->fs_info->generation); |
dc17ff8f | 1541 | |
5d4f98a2 | 1542 | if (!should_cow_block(trans, root, buf)) { |
64c12921 | 1543 | trans->dirty = true; |
6702ed49 CM |
1544 | *cow_ret = buf; |
1545 | return 0; | |
1546 | } | |
c487685d | 1547 | |
ee22184b | 1548 | search_start = buf->start & ~((u64)SZ_1G - 1); |
b4ce94de CM |
1549 | |
1550 | if (parent) | |
1551 | btrfs_set_lock_blocking(parent); | |
1552 | btrfs_set_lock_blocking(buf); | |
1553 | ||
f510cfec | 1554 | ret = __btrfs_cow_block(trans, root, buf, parent, |
9fa8cfe7 | 1555 | parent_slot, cow_ret, search_start, 0); |
1abe9b8a | 1556 | |
1557 | trace_btrfs_cow_block(root, buf, *cow_ret); | |
1558 | ||
f510cfec | 1559 | return ret; |
6702ed49 CM |
1560 | } |
1561 | ||
d352ac68 CM |
1562 | /* |
1563 | * helper function for defrag to decide if two blocks pointed to by a | |
1564 | * node are actually close by | |
1565 | */ | |
6b80053d | 1566 | static int close_blocks(u64 blocknr, u64 other, u32 blocksize) |
6702ed49 | 1567 | { |
6b80053d | 1568 | if (blocknr < other && other - (blocknr + blocksize) < 32768) |
6702ed49 | 1569 | return 1; |
6b80053d | 1570 | if (blocknr > other && blocknr - (other + blocksize) < 32768) |
6702ed49 CM |
1571 | return 1; |
1572 | return 0; | |
1573 | } | |
1574 | ||
081e9573 CM |
1575 | /* |
1576 | * compare two keys in a memcmp fashion | |
1577 | */ | |
1578 | static int comp_keys(struct btrfs_disk_key *disk, struct btrfs_key *k2) | |
1579 | { | |
1580 | struct btrfs_key k1; | |
1581 | ||
1582 | btrfs_disk_key_to_cpu(&k1, disk); | |
1583 | ||
20736aba | 1584 | return btrfs_comp_cpu_keys(&k1, k2); |
081e9573 CM |
1585 | } |
1586 | ||
f3465ca4 JB |
1587 | /* |
1588 | * same as comp_keys only with two btrfs_key's | |
1589 | */ | |
5d4f98a2 | 1590 | int btrfs_comp_cpu_keys(struct btrfs_key *k1, struct btrfs_key *k2) |
f3465ca4 JB |
1591 | { |
1592 | if (k1->objectid > k2->objectid) | |
1593 | return 1; | |
1594 | if (k1->objectid < k2->objectid) | |
1595 | return -1; | |
1596 | if (k1->type > k2->type) | |
1597 | return 1; | |
1598 | if (k1->type < k2->type) | |
1599 | return -1; | |
1600 | if (k1->offset > k2->offset) | |
1601 | return 1; | |
1602 | if (k1->offset < k2->offset) | |
1603 | return -1; | |
1604 | return 0; | |
1605 | } | |
081e9573 | 1606 | |
d352ac68 CM |
1607 | /* |
1608 | * this is used by the defrag code to go through all the | |
1609 | * leaves pointed to by a node and reallocate them so that | |
1610 | * disk order is close to key order | |
1611 | */ | |
6702ed49 | 1612 | int btrfs_realloc_node(struct btrfs_trans_handle *trans, |
5f39d397 | 1613 | struct btrfs_root *root, struct extent_buffer *parent, |
de78b51a | 1614 | int start_slot, u64 *last_ret, |
a6b6e75e | 1615 | struct btrfs_key *progress) |
6702ed49 | 1616 | { |
6b80053d | 1617 | struct extent_buffer *cur; |
6702ed49 | 1618 | u64 blocknr; |
ca7a79ad | 1619 | u64 gen; |
e9d0b13b CM |
1620 | u64 search_start = *last_ret; |
1621 | u64 last_block = 0; | |
6702ed49 CM |
1622 | u64 other; |
1623 | u32 parent_nritems; | |
6702ed49 CM |
1624 | int end_slot; |
1625 | int i; | |
1626 | int err = 0; | |
f2183bde | 1627 | int parent_level; |
6b80053d CM |
1628 | int uptodate; |
1629 | u32 blocksize; | |
081e9573 CM |
1630 | int progress_passed = 0; |
1631 | struct btrfs_disk_key disk_key; | |
6702ed49 | 1632 | |
5708b959 | 1633 | parent_level = btrfs_header_level(parent); |
5708b959 | 1634 | |
6c1500f2 JL |
1635 | WARN_ON(trans->transaction != root->fs_info->running_transaction); |
1636 | WARN_ON(trans->transid != root->fs_info->generation); | |
86479a04 | 1637 | |
6b80053d | 1638 | parent_nritems = btrfs_header_nritems(parent); |
707e8a07 | 1639 | blocksize = root->nodesize; |
5dfe2be7 | 1640 | end_slot = parent_nritems - 1; |
6702ed49 | 1641 | |
5dfe2be7 | 1642 | if (parent_nritems <= 1) |
6702ed49 CM |
1643 | return 0; |
1644 | ||
b4ce94de CM |
1645 | btrfs_set_lock_blocking(parent); |
1646 | ||
5dfe2be7 | 1647 | for (i = start_slot; i <= end_slot; i++) { |
6702ed49 | 1648 | int close = 1; |
a6b6e75e | 1649 | |
081e9573 CM |
1650 | btrfs_node_key(parent, &disk_key, i); |
1651 | if (!progress_passed && comp_keys(&disk_key, progress) < 0) | |
1652 | continue; | |
1653 | ||
1654 | progress_passed = 1; | |
6b80053d | 1655 | blocknr = btrfs_node_blockptr(parent, i); |
ca7a79ad | 1656 | gen = btrfs_node_ptr_generation(parent, i); |
e9d0b13b CM |
1657 | if (last_block == 0) |
1658 | last_block = blocknr; | |
5708b959 | 1659 | |
6702ed49 | 1660 | if (i > 0) { |
6b80053d CM |
1661 | other = btrfs_node_blockptr(parent, i - 1); |
1662 | close = close_blocks(blocknr, other, blocksize); | |
6702ed49 | 1663 | } |
5dfe2be7 | 1664 | if (!close && i < end_slot) { |
6b80053d CM |
1665 | other = btrfs_node_blockptr(parent, i + 1); |
1666 | close = close_blocks(blocknr, other, blocksize); | |
6702ed49 | 1667 | } |
e9d0b13b CM |
1668 | if (close) { |
1669 | last_block = blocknr; | |
6702ed49 | 1670 | continue; |
e9d0b13b | 1671 | } |
6702ed49 | 1672 | |
62d1f9fe | 1673 | cur = find_extent_buffer(root->fs_info, blocknr); |
6b80053d | 1674 | if (cur) |
b9fab919 | 1675 | uptodate = btrfs_buffer_uptodate(cur, gen, 0); |
6b80053d CM |
1676 | else |
1677 | uptodate = 0; | |
5708b959 | 1678 | if (!cur || !uptodate) { |
6b80053d | 1679 | if (!cur) { |
ce86cd59 | 1680 | cur = read_tree_block(root, blocknr, gen); |
64c043de LB |
1681 | if (IS_ERR(cur)) { |
1682 | return PTR_ERR(cur); | |
1683 | } else if (!extent_buffer_uptodate(cur)) { | |
416bc658 | 1684 | free_extent_buffer(cur); |
97d9a8a4 | 1685 | return -EIO; |
416bc658 | 1686 | } |
6b80053d | 1687 | } else if (!uptodate) { |
018642a1 TI |
1688 | err = btrfs_read_buffer(cur, gen); |
1689 | if (err) { | |
1690 | free_extent_buffer(cur); | |
1691 | return err; | |
1692 | } | |
f2183bde | 1693 | } |
6702ed49 | 1694 | } |
e9d0b13b | 1695 | if (search_start == 0) |
6b80053d | 1696 | search_start = last_block; |
e9d0b13b | 1697 | |
e7a84565 | 1698 | btrfs_tree_lock(cur); |
b4ce94de | 1699 | btrfs_set_lock_blocking(cur); |
6b80053d | 1700 | err = __btrfs_cow_block(trans, root, cur, parent, i, |
e7a84565 | 1701 | &cur, search_start, |
6b80053d | 1702 | min(16 * blocksize, |
9fa8cfe7 | 1703 | (end_slot - i) * blocksize)); |
252c38f0 | 1704 | if (err) { |
e7a84565 | 1705 | btrfs_tree_unlock(cur); |
6b80053d | 1706 | free_extent_buffer(cur); |
6702ed49 | 1707 | break; |
252c38f0 | 1708 | } |
e7a84565 CM |
1709 | search_start = cur->start; |
1710 | last_block = cur->start; | |
f2183bde | 1711 | *last_ret = search_start; |
e7a84565 CM |
1712 | btrfs_tree_unlock(cur); |
1713 | free_extent_buffer(cur); | |
6702ed49 CM |
1714 | } |
1715 | return err; | |
1716 | } | |
1717 | ||
aa5d6bed | 1718 | |
74123bd7 | 1719 | /* |
5f39d397 CM |
1720 | * search for key in the extent_buffer. The items start at offset p, |
1721 | * and they are item_size apart. There are 'max' items in p. | |
1722 | * | |
74123bd7 CM |
1723 | * the slot in the array is returned via slot, and it points to |
1724 | * the place where you would insert key if it is not found in | |
1725 | * the array. | |
1726 | * | |
1727 | * slot may point to max if the key is bigger than all of the keys | |
1728 | */ | |
e02119d5 CM |
1729 | static noinline int generic_bin_search(struct extent_buffer *eb, |
1730 | unsigned long p, | |
1731 | int item_size, struct btrfs_key *key, | |
1732 | int max, int *slot) | |
be0e5c09 CM |
1733 | { |
1734 | int low = 0; | |
1735 | int high = max; | |
1736 | int mid; | |
1737 | int ret; | |
479965d6 | 1738 | struct btrfs_disk_key *tmp = NULL; |
5f39d397 CM |
1739 | struct btrfs_disk_key unaligned; |
1740 | unsigned long offset; | |
5f39d397 CM |
1741 | char *kaddr = NULL; |
1742 | unsigned long map_start = 0; | |
1743 | unsigned long map_len = 0; | |
479965d6 | 1744 | int err; |
be0e5c09 | 1745 | |
5e24e9af LB |
1746 | if (low > high) { |
1747 | btrfs_err(eb->fs_info, | |
1748 | "%s: low (%d) > high (%d) eb %llu owner %llu level %d", | |
1749 | __func__, low, high, eb->start, | |
1750 | btrfs_header_owner(eb), btrfs_header_level(eb)); | |
1751 | return -EINVAL; | |
1752 | } | |
1753 | ||
d397712b | 1754 | while (low < high) { |
be0e5c09 | 1755 | mid = (low + high) / 2; |
5f39d397 CM |
1756 | offset = p + mid * item_size; |
1757 | ||
a6591715 | 1758 | if (!kaddr || offset < map_start || |
5f39d397 CM |
1759 | (offset + sizeof(struct btrfs_disk_key)) > |
1760 | map_start + map_len) { | |
934d375b CM |
1761 | |
1762 | err = map_private_extent_buffer(eb, offset, | |
479965d6 | 1763 | sizeof(struct btrfs_disk_key), |
a6591715 | 1764 | &kaddr, &map_start, &map_len); |
479965d6 CM |
1765 | |
1766 | if (!err) { | |
1767 | tmp = (struct btrfs_disk_key *)(kaddr + offset - | |
1768 | map_start); | |
415b35a5 | 1769 | } else if (err == 1) { |
479965d6 CM |
1770 | read_extent_buffer(eb, &unaligned, |
1771 | offset, sizeof(unaligned)); | |
1772 | tmp = &unaligned; | |
415b35a5 LB |
1773 | } else { |
1774 | return err; | |
479965d6 | 1775 | } |
5f39d397 | 1776 | |
5f39d397 CM |
1777 | } else { |
1778 | tmp = (struct btrfs_disk_key *)(kaddr + offset - | |
1779 | map_start); | |
1780 | } | |
be0e5c09 CM |
1781 | ret = comp_keys(tmp, key); |
1782 | ||
1783 | if (ret < 0) | |
1784 | low = mid + 1; | |
1785 | else if (ret > 0) | |
1786 | high = mid; | |
1787 | else { | |
1788 | *slot = mid; | |
1789 | return 0; | |
1790 | } | |
1791 | } | |
1792 | *slot = low; | |
1793 | return 1; | |
1794 | } | |
1795 | ||
97571fd0 CM |
1796 | /* |
1797 | * simple bin_search frontend that does the right thing for | |
1798 | * leaves vs nodes | |
1799 | */ | |
5f39d397 CM |
1800 | static int bin_search(struct extent_buffer *eb, struct btrfs_key *key, |
1801 | int level, int *slot) | |
be0e5c09 | 1802 | { |
f775738f | 1803 | if (level == 0) |
5f39d397 CM |
1804 | return generic_bin_search(eb, |
1805 | offsetof(struct btrfs_leaf, items), | |
0783fcfc | 1806 | sizeof(struct btrfs_item), |
5f39d397 | 1807 | key, btrfs_header_nritems(eb), |
7518a238 | 1808 | slot); |
f775738f | 1809 | else |
5f39d397 CM |
1810 | return generic_bin_search(eb, |
1811 | offsetof(struct btrfs_node, ptrs), | |
123abc88 | 1812 | sizeof(struct btrfs_key_ptr), |
5f39d397 | 1813 | key, btrfs_header_nritems(eb), |
7518a238 | 1814 | slot); |
be0e5c09 CM |
1815 | } |
1816 | ||
5d4f98a2 YZ |
1817 | int btrfs_bin_search(struct extent_buffer *eb, struct btrfs_key *key, |
1818 | int level, int *slot) | |
1819 | { | |
1820 | return bin_search(eb, key, level, slot); | |
1821 | } | |
1822 | ||
f0486c68 YZ |
1823 | static void root_add_used(struct btrfs_root *root, u32 size) |
1824 | { | |
1825 | spin_lock(&root->accounting_lock); | |
1826 | btrfs_set_root_used(&root->root_item, | |
1827 | btrfs_root_used(&root->root_item) + size); | |
1828 | spin_unlock(&root->accounting_lock); | |
1829 | } | |
1830 | ||
1831 | static void root_sub_used(struct btrfs_root *root, u32 size) | |
1832 | { | |
1833 | spin_lock(&root->accounting_lock); | |
1834 | btrfs_set_root_used(&root->root_item, | |
1835 | btrfs_root_used(&root->root_item) - size); | |
1836 | spin_unlock(&root->accounting_lock); | |
1837 | } | |
1838 | ||
d352ac68 CM |
1839 | /* given a node and slot number, this reads the blocks it points to. The |
1840 | * extent buffer is returned with a reference taken (but unlocked). | |
d352ac68 | 1841 | */ |
e02119d5 | 1842 | static noinline struct extent_buffer *read_node_slot(struct btrfs_root *root, |
5f39d397 | 1843 | struct extent_buffer *parent, int slot) |
bb803951 | 1844 | { |
ca7a79ad | 1845 | int level = btrfs_header_level(parent); |
416bc658 JB |
1846 | struct extent_buffer *eb; |
1847 | ||
fb770ae4 LB |
1848 | if (slot < 0 || slot >= btrfs_header_nritems(parent)) |
1849 | return ERR_PTR(-ENOENT); | |
ca7a79ad CM |
1850 | |
1851 | BUG_ON(level == 0); | |
1852 | ||
416bc658 | 1853 | eb = read_tree_block(root, btrfs_node_blockptr(parent, slot), |
416bc658 | 1854 | btrfs_node_ptr_generation(parent, slot)); |
fb770ae4 LB |
1855 | if (!IS_ERR(eb) && !extent_buffer_uptodate(eb)) { |
1856 | free_extent_buffer(eb); | |
1857 | eb = ERR_PTR(-EIO); | |
416bc658 JB |
1858 | } |
1859 | ||
1860 | return eb; | |
bb803951 CM |
1861 | } |
1862 | ||
d352ac68 CM |
1863 | /* |
1864 | * node level balancing, used to make sure nodes are in proper order for | |
1865 | * item deletion. We balance from the top down, so we have to make sure | |
1866 | * that a deletion won't leave an node completely empty later on. | |
1867 | */ | |
e02119d5 | 1868 | static noinline int balance_level(struct btrfs_trans_handle *trans, |
98ed5174 CM |
1869 | struct btrfs_root *root, |
1870 | struct btrfs_path *path, int level) | |
bb803951 | 1871 | { |
5f39d397 CM |
1872 | struct extent_buffer *right = NULL; |
1873 | struct extent_buffer *mid; | |
1874 | struct extent_buffer *left = NULL; | |
1875 | struct extent_buffer *parent = NULL; | |
bb803951 CM |
1876 | int ret = 0; |
1877 | int wret; | |
1878 | int pslot; | |
bb803951 | 1879 | int orig_slot = path->slots[level]; |
79f95c82 | 1880 | u64 orig_ptr; |
bb803951 CM |
1881 | |
1882 | if (level == 0) | |
1883 | return 0; | |
1884 | ||
5f39d397 | 1885 | mid = path->nodes[level]; |
b4ce94de | 1886 | |
bd681513 CM |
1887 | WARN_ON(path->locks[level] != BTRFS_WRITE_LOCK && |
1888 | path->locks[level] != BTRFS_WRITE_LOCK_BLOCKING); | |
7bb86316 CM |
1889 | WARN_ON(btrfs_header_generation(mid) != trans->transid); |
1890 | ||
1d4f8a0c | 1891 | orig_ptr = btrfs_node_blockptr(mid, orig_slot); |
79f95c82 | 1892 | |
a05a9bb1 | 1893 | if (level < BTRFS_MAX_LEVEL - 1) { |
5f39d397 | 1894 | parent = path->nodes[level + 1]; |
a05a9bb1 LZ |
1895 | pslot = path->slots[level + 1]; |
1896 | } | |
bb803951 | 1897 | |
40689478 CM |
1898 | /* |
1899 | * deal with the case where there is only one pointer in the root | |
1900 | * by promoting the node below to a root | |
1901 | */ | |
5f39d397 CM |
1902 | if (!parent) { |
1903 | struct extent_buffer *child; | |
bb803951 | 1904 | |
5f39d397 | 1905 | if (btrfs_header_nritems(mid) != 1) |
bb803951 CM |
1906 | return 0; |
1907 | ||
1908 | /* promote the child to a root */ | |
5f39d397 | 1909 | child = read_node_slot(root, mid, 0); |
fb770ae4 LB |
1910 | if (IS_ERR(child)) { |
1911 | ret = PTR_ERR(child); | |
34d97007 | 1912 | btrfs_handle_fs_error(root->fs_info, ret, NULL); |
305a26af MF |
1913 | goto enospc; |
1914 | } | |
1915 | ||
925baedd | 1916 | btrfs_tree_lock(child); |
b4ce94de | 1917 | btrfs_set_lock_blocking(child); |
9fa8cfe7 | 1918 | ret = btrfs_cow_block(trans, root, child, mid, 0, &child); |
f0486c68 YZ |
1919 | if (ret) { |
1920 | btrfs_tree_unlock(child); | |
1921 | free_extent_buffer(child); | |
1922 | goto enospc; | |
1923 | } | |
2f375ab9 | 1924 | |
90f8d62e | 1925 | tree_mod_log_set_root_pointer(root, child, 1); |
240f62c8 | 1926 | rcu_assign_pointer(root->node, child); |
925baedd | 1927 | |
0b86a832 | 1928 | add_root_to_dirty_list(root); |
925baedd | 1929 | btrfs_tree_unlock(child); |
b4ce94de | 1930 | |
925baedd | 1931 | path->locks[level] = 0; |
bb803951 | 1932 | path->nodes[level] = NULL; |
01d58472 | 1933 | clean_tree_block(trans, root->fs_info, mid); |
925baedd | 1934 | btrfs_tree_unlock(mid); |
bb803951 | 1935 | /* once for the path */ |
5f39d397 | 1936 | free_extent_buffer(mid); |
f0486c68 YZ |
1937 | |
1938 | root_sub_used(root, mid->len); | |
5581a51a | 1939 | btrfs_free_tree_block(trans, root, mid, 0, 1); |
bb803951 | 1940 | /* once for the root ptr */ |
3083ee2e | 1941 | free_extent_buffer_stale(mid); |
f0486c68 | 1942 | return 0; |
bb803951 | 1943 | } |
5f39d397 | 1944 | if (btrfs_header_nritems(mid) > |
123abc88 | 1945 | BTRFS_NODEPTRS_PER_BLOCK(root) / 4) |
bb803951 CM |
1946 | return 0; |
1947 | ||
5f39d397 | 1948 | left = read_node_slot(root, parent, pslot - 1); |
fb770ae4 LB |
1949 | if (IS_ERR(left)) |
1950 | left = NULL; | |
1951 | ||
5f39d397 | 1952 | if (left) { |
925baedd | 1953 | btrfs_tree_lock(left); |
b4ce94de | 1954 | btrfs_set_lock_blocking(left); |
5f39d397 | 1955 | wret = btrfs_cow_block(trans, root, left, |
9fa8cfe7 | 1956 | parent, pslot - 1, &left); |
54aa1f4d CM |
1957 | if (wret) { |
1958 | ret = wret; | |
1959 | goto enospc; | |
1960 | } | |
2cc58cf2 | 1961 | } |
fb770ae4 | 1962 | |
5f39d397 | 1963 | right = read_node_slot(root, parent, pslot + 1); |
fb770ae4 LB |
1964 | if (IS_ERR(right)) |
1965 | right = NULL; | |
1966 | ||
5f39d397 | 1967 | if (right) { |
925baedd | 1968 | btrfs_tree_lock(right); |
b4ce94de | 1969 | btrfs_set_lock_blocking(right); |
5f39d397 | 1970 | wret = btrfs_cow_block(trans, root, right, |
9fa8cfe7 | 1971 | parent, pslot + 1, &right); |
2cc58cf2 CM |
1972 | if (wret) { |
1973 | ret = wret; | |
1974 | goto enospc; | |
1975 | } | |
1976 | } | |
1977 | ||
1978 | /* first, try to make some room in the middle buffer */ | |
5f39d397 CM |
1979 | if (left) { |
1980 | orig_slot += btrfs_header_nritems(left); | |
bce4eae9 | 1981 | wret = push_node_left(trans, root, left, mid, 1); |
79f95c82 CM |
1982 | if (wret < 0) |
1983 | ret = wret; | |
bb803951 | 1984 | } |
79f95c82 CM |
1985 | |
1986 | /* | |
1987 | * then try to empty the right most buffer into the middle | |
1988 | */ | |
5f39d397 | 1989 | if (right) { |
971a1f66 | 1990 | wret = push_node_left(trans, root, mid, right, 1); |
54aa1f4d | 1991 | if (wret < 0 && wret != -ENOSPC) |
79f95c82 | 1992 | ret = wret; |
5f39d397 | 1993 | if (btrfs_header_nritems(right) == 0) { |
01d58472 | 1994 | clean_tree_block(trans, root->fs_info, right); |
925baedd | 1995 | btrfs_tree_unlock(right); |
afe5fea7 | 1996 | del_ptr(root, path, level + 1, pslot + 1); |
f0486c68 | 1997 | root_sub_used(root, right->len); |
5581a51a | 1998 | btrfs_free_tree_block(trans, root, right, 0, 1); |
3083ee2e | 1999 | free_extent_buffer_stale(right); |
f0486c68 | 2000 | right = NULL; |
bb803951 | 2001 | } else { |
5f39d397 CM |
2002 | struct btrfs_disk_key right_key; |
2003 | btrfs_node_key(right, &right_key, 0); | |
f230475e | 2004 | tree_mod_log_set_node_key(root->fs_info, parent, |
32adf090 | 2005 | pslot + 1, 0); |
5f39d397 CM |
2006 | btrfs_set_node_key(parent, &right_key, pslot + 1); |
2007 | btrfs_mark_buffer_dirty(parent); | |
bb803951 CM |
2008 | } |
2009 | } | |
5f39d397 | 2010 | if (btrfs_header_nritems(mid) == 1) { |
79f95c82 CM |
2011 | /* |
2012 | * we're not allowed to leave a node with one item in the | |
2013 | * tree during a delete. A deletion from lower in the tree | |
2014 | * could try to delete the only pointer in this node. | |
2015 | * So, pull some keys from the left. | |
2016 | * There has to be a left pointer at this point because | |
2017 | * otherwise we would have pulled some pointers from the | |
2018 | * right | |
2019 | */ | |
305a26af MF |
2020 | if (!left) { |
2021 | ret = -EROFS; | |
34d97007 | 2022 | btrfs_handle_fs_error(root->fs_info, ret, NULL); |
305a26af MF |
2023 | goto enospc; |
2024 | } | |
5f39d397 | 2025 | wret = balance_node_right(trans, root, mid, left); |
54aa1f4d | 2026 | if (wret < 0) { |
79f95c82 | 2027 | ret = wret; |
54aa1f4d CM |
2028 | goto enospc; |
2029 | } | |
bce4eae9 CM |
2030 | if (wret == 1) { |
2031 | wret = push_node_left(trans, root, left, mid, 1); | |
2032 | if (wret < 0) | |
2033 | ret = wret; | |
2034 | } | |
79f95c82 CM |
2035 | BUG_ON(wret == 1); |
2036 | } | |
5f39d397 | 2037 | if (btrfs_header_nritems(mid) == 0) { |
01d58472 | 2038 | clean_tree_block(trans, root->fs_info, mid); |
925baedd | 2039 | btrfs_tree_unlock(mid); |
afe5fea7 | 2040 | del_ptr(root, path, level + 1, pslot); |
f0486c68 | 2041 | root_sub_used(root, mid->len); |
5581a51a | 2042 | btrfs_free_tree_block(trans, root, mid, 0, 1); |
3083ee2e | 2043 | free_extent_buffer_stale(mid); |
f0486c68 | 2044 | mid = NULL; |
79f95c82 CM |
2045 | } else { |
2046 | /* update the parent key to reflect our changes */ | |
5f39d397 CM |
2047 | struct btrfs_disk_key mid_key; |
2048 | btrfs_node_key(mid, &mid_key, 0); | |
32adf090 | 2049 | tree_mod_log_set_node_key(root->fs_info, parent, |
f230475e | 2050 | pslot, 0); |
5f39d397 CM |
2051 | btrfs_set_node_key(parent, &mid_key, pslot); |
2052 | btrfs_mark_buffer_dirty(parent); | |
79f95c82 | 2053 | } |
bb803951 | 2054 | |
79f95c82 | 2055 | /* update the path */ |
5f39d397 CM |
2056 | if (left) { |
2057 | if (btrfs_header_nritems(left) > orig_slot) { | |
2058 | extent_buffer_get(left); | |
925baedd | 2059 | /* left was locked after cow */ |
5f39d397 | 2060 | path->nodes[level] = left; |
bb803951 CM |
2061 | path->slots[level + 1] -= 1; |
2062 | path->slots[level] = orig_slot; | |
925baedd CM |
2063 | if (mid) { |
2064 | btrfs_tree_unlock(mid); | |
5f39d397 | 2065 | free_extent_buffer(mid); |
925baedd | 2066 | } |
bb803951 | 2067 | } else { |
5f39d397 | 2068 | orig_slot -= btrfs_header_nritems(left); |
bb803951 CM |
2069 | path->slots[level] = orig_slot; |
2070 | } | |
2071 | } | |
79f95c82 | 2072 | /* double check we haven't messed things up */ |
e20d96d6 | 2073 | if (orig_ptr != |
5f39d397 | 2074 | btrfs_node_blockptr(path->nodes[level], path->slots[level])) |
79f95c82 | 2075 | BUG(); |
54aa1f4d | 2076 | enospc: |
925baedd CM |
2077 | if (right) { |
2078 | btrfs_tree_unlock(right); | |
5f39d397 | 2079 | free_extent_buffer(right); |
925baedd CM |
2080 | } |
2081 | if (left) { | |
2082 | if (path->nodes[level] != left) | |
2083 | btrfs_tree_unlock(left); | |
5f39d397 | 2084 | free_extent_buffer(left); |
925baedd | 2085 | } |
bb803951 CM |
2086 | return ret; |
2087 | } | |
2088 | ||
d352ac68 CM |
2089 | /* Node balancing for insertion. Here we only split or push nodes around |
2090 | * when they are completely full. This is also done top down, so we | |
2091 | * have to be pessimistic. | |
2092 | */ | |
d397712b | 2093 | static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans, |
98ed5174 CM |
2094 | struct btrfs_root *root, |
2095 | struct btrfs_path *path, int level) | |
e66f709b | 2096 | { |
5f39d397 CM |
2097 | struct extent_buffer *right = NULL; |
2098 | struct extent_buffer *mid; | |
2099 | struct extent_buffer *left = NULL; | |
2100 | struct extent_buffer *parent = NULL; | |
e66f709b CM |
2101 | int ret = 0; |
2102 | int wret; | |
2103 | int pslot; | |
2104 | int orig_slot = path->slots[level]; | |
e66f709b CM |
2105 | |
2106 | if (level == 0) | |
2107 | return 1; | |
2108 | ||
5f39d397 | 2109 | mid = path->nodes[level]; |
7bb86316 | 2110 | WARN_ON(btrfs_header_generation(mid) != trans->transid); |
e66f709b | 2111 | |
a05a9bb1 | 2112 | if (level < BTRFS_MAX_LEVEL - 1) { |
5f39d397 | 2113 | parent = path->nodes[level + 1]; |
a05a9bb1 LZ |
2114 | pslot = path->slots[level + 1]; |
2115 | } | |
e66f709b | 2116 | |
5f39d397 | 2117 | if (!parent) |
e66f709b | 2118 | return 1; |
e66f709b | 2119 | |
5f39d397 | 2120 | left = read_node_slot(root, parent, pslot - 1); |
fb770ae4 LB |
2121 | if (IS_ERR(left)) |
2122 | left = NULL; | |
e66f709b CM |
2123 | |
2124 | /* first, try to make some room in the middle buffer */ | |
5f39d397 | 2125 | if (left) { |
e66f709b | 2126 | u32 left_nr; |
925baedd CM |
2127 | |
2128 | btrfs_tree_lock(left); | |
b4ce94de CM |
2129 | btrfs_set_lock_blocking(left); |
2130 | ||
5f39d397 | 2131 | left_nr = btrfs_header_nritems(left); |
33ade1f8 CM |
2132 | if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) { |
2133 | wret = 1; | |
2134 | } else { | |
5f39d397 | 2135 | ret = btrfs_cow_block(trans, root, left, parent, |
9fa8cfe7 | 2136 | pslot - 1, &left); |
54aa1f4d CM |
2137 | if (ret) |
2138 | wret = 1; | |
2139 | else { | |
54aa1f4d | 2140 | wret = push_node_left(trans, root, |
971a1f66 | 2141 | left, mid, 0); |
54aa1f4d | 2142 | } |
33ade1f8 | 2143 | } |
e66f709b CM |
2144 | if (wret < 0) |
2145 | ret = wret; | |
2146 | if (wret == 0) { | |
5f39d397 | 2147 | struct btrfs_disk_key disk_key; |
e66f709b | 2148 | orig_slot += left_nr; |
5f39d397 | 2149 | btrfs_node_key(mid, &disk_key, 0); |
f230475e | 2150 | tree_mod_log_set_node_key(root->fs_info, parent, |
32adf090 | 2151 | pslot, 0); |
5f39d397 CM |
2152 | btrfs_set_node_key(parent, &disk_key, pslot); |
2153 | btrfs_mark_buffer_dirty(parent); | |
2154 | if (btrfs_header_nritems(left) > orig_slot) { | |
2155 | path->nodes[level] = left; | |
e66f709b CM |
2156 | path->slots[level + 1] -= 1; |
2157 | path->slots[level] = orig_slot; | |
925baedd | 2158 | btrfs_tree_unlock(mid); |
5f39d397 | 2159 | free_extent_buffer(mid); |
e66f709b CM |
2160 | } else { |
2161 | orig_slot -= | |
5f39d397 | 2162 | btrfs_header_nritems(left); |
e66f709b | 2163 | path->slots[level] = orig_slot; |
925baedd | 2164 | btrfs_tree_unlock(left); |
5f39d397 | 2165 | free_extent_buffer(left); |
e66f709b | 2166 | } |
e66f709b CM |
2167 | return 0; |
2168 | } | |
925baedd | 2169 | btrfs_tree_unlock(left); |
5f39d397 | 2170 | free_extent_buffer(left); |
e66f709b | 2171 | } |
925baedd | 2172 | right = read_node_slot(root, parent, pslot + 1); |
fb770ae4 LB |
2173 | if (IS_ERR(right)) |
2174 | right = NULL; | |
e66f709b CM |
2175 | |
2176 | /* | |
2177 | * then try to empty the right most buffer into the middle | |
2178 | */ | |
5f39d397 | 2179 | if (right) { |
33ade1f8 | 2180 | u32 right_nr; |
b4ce94de | 2181 | |
925baedd | 2182 | btrfs_tree_lock(right); |
b4ce94de CM |
2183 | btrfs_set_lock_blocking(right); |
2184 | ||
5f39d397 | 2185 | right_nr = btrfs_header_nritems(right); |
33ade1f8 CM |
2186 | if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) { |
2187 | wret = 1; | |
2188 | } else { | |
5f39d397 CM |
2189 | ret = btrfs_cow_block(trans, root, right, |
2190 | parent, pslot + 1, | |
9fa8cfe7 | 2191 | &right); |
54aa1f4d CM |
2192 | if (ret) |
2193 | wret = 1; | |
2194 | else { | |
54aa1f4d | 2195 | wret = balance_node_right(trans, root, |
5f39d397 | 2196 | right, mid); |
54aa1f4d | 2197 | } |
33ade1f8 | 2198 | } |
e66f709b CM |
2199 | if (wret < 0) |
2200 | ret = wret; | |
2201 | if (wret == 0) { | |
5f39d397 CM |
2202 | struct btrfs_disk_key disk_key; |
2203 | ||
2204 | btrfs_node_key(right, &disk_key, 0); | |
f230475e | 2205 | tree_mod_log_set_node_key(root->fs_info, parent, |
32adf090 | 2206 | pslot + 1, 0); |
5f39d397 CM |
2207 | btrfs_set_node_key(parent, &disk_key, pslot + 1); |
2208 | btrfs_mark_buffer_dirty(parent); | |
2209 | ||
2210 | if (btrfs_header_nritems(mid) <= orig_slot) { | |
2211 | path->nodes[level] = right; | |
e66f709b CM |
2212 | path->slots[level + 1] += 1; |
2213 | path->slots[level] = orig_slot - | |
5f39d397 | 2214 | btrfs_header_nritems(mid); |
925baedd | 2215 | btrfs_tree_unlock(mid); |
5f39d397 | 2216 | free_extent_buffer(mid); |
e66f709b | 2217 | } else { |
925baedd | 2218 | btrfs_tree_unlock(right); |
5f39d397 | 2219 | free_extent_buffer(right); |
e66f709b | 2220 | } |
e66f709b CM |
2221 | return 0; |
2222 | } | |
925baedd | 2223 | btrfs_tree_unlock(right); |
5f39d397 | 2224 | free_extent_buffer(right); |
e66f709b | 2225 | } |
e66f709b CM |
2226 | return 1; |
2227 | } | |
2228 | ||
3c69faec | 2229 | /* |
d352ac68 CM |
2230 | * readahead one full node of leaves, finding things that are close |
2231 | * to the block in 'slot', and triggering ra on them. | |
3c69faec | 2232 | */ |
c8c42864 CM |
2233 | static void reada_for_search(struct btrfs_root *root, |
2234 | struct btrfs_path *path, | |
2235 | int level, int slot, u64 objectid) | |
3c69faec | 2236 | { |
5f39d397 | 2237 | struct extent_buffer *node; |
01f46658 | 2238 | struct btrfs_disk_key disk_key; |
3c69faec | 2239 | u32 nritems; |
3c69faec | 2240 | u64 search; |
a7175319 | 2241 | u64 target; |
6b80053d | 2242 | u64 nread = 0; |
5f39d397 | 2243 | struct extent_buffer *eb; |
6b80053d CM |
2244 | u32 nr; |
2245 | u32 blocksize; | |
2246 | u32 nscan = 0; | |
db94535d | 2247 | |
a6b6e75e | 2248 | if (level != 1) |
6702ed49 CM |
2249 | return; |
2250 | ||
2251 | if (!path->nodes[level]) | |
3c69faec CM |
2252 | return; |
2253 | ||
5f39d397 | 2254 | node = path->nodes[level]; |
925baedd | 2255 | |
3c69faec | 2256 | search = btrfs_node_blockptr(node, slot); |
707e8a07 | 2257 | blocksize = root->nodesize; |
62d1f9fe | 2258 | eb = find_extent_buffer(root->fs_info, search); |
5f39d397 CM |
2259 | if (eb) { |
2260 | free_extent_buffer(eb); | |
3c69faec CM |
2261 | return; |
2262 | } | |
2263 | ||
a7175319 | 2264 | target = search; |
6b80053d | 2265 | |
5f39d397 | 2266 | nritems = btrfs_header_nritems(node); |
6b80053d | 2267 | nr = slot; |
25b8b936 | 2268 | |
d397712b | 2269 | while (1) { |
e4058b54 | 2270 | if (path->reada == READA_BACK) { |
6b80053d CM |
2271 | if (nr == 0) |
2272 | break; | |
2273 | nr--; | |
e4058b54 | 2274 | } else if (path->reada == READA_FORWARD) { |
6b80053d CM |
2275 | nr++; |
2276 | if (nr >= nritems) | |
2277 | break; | |
3c69faec | 2278 | } |
e4058b54 | 2279 | if (path->reada == READA_BACK && objectid) { |
01f46658 CM |
2280 | btrfs_node_key(node, &disk_key, nr); |
2281 | if (btrfs_disk_key_objectid(&disk_key) != objectid) | |
2282 | break; | |
2283 | } | |
6b80053d | 2284 | search = btrfs_node_blockptr(node, nr); |
a7175319 CM |
2285 | if ((search <= target && target - search <= 65536) || |
2286 | (search > target && search - target <= 65536)) { | |
d3e46fea | 2287 | readahead_tree_block(root, search); |
6b80053d CM |
2288 | nread += blocksize; |
2289 | } | |
2290 | nscan++; | |
a7175319 | 2291 | if ((nread > 65536 || nscan > 32)) |
6b80053d | 2292 | break; |
3c69faec CM |
2293 | } |
2294 | } | |
925baedd | 2295 | |
0b08851f JB |
2296 | static noinline void reada_for_balance(struct btrfs_root *root, |
2297 | struct btrfs_path *path, int level) | |
b4ce94de CM |
2298 | { |
2299 | int slot; | |
2300 | int nritems; | |
2301 | struct extent_buffer *parent; | |
2302 | struct extent_buffer *eb; | |
2303 | u64 gen; | |
2304 | u64 block1 = 0; | |
2305 | u64 block2 = 0; | |
b4ce94de | 2306 | |
8c594ea8 | 2307 | parent = path->nodes[level + 1]; |
b4ce94de | 2308 | if (!parent) |
0b08851f | 2309 | return; |
b4ce94de CM |
2310 | |
2311 | nritems = btrfs_header_nritems(parent); | |
8c594ea8 | 2312 | slot = path->slots[level + 1]; |
b4ce94de CM |
2313 | |
2314 | if (slot > 0) { | |
2315 | block1 = btrfs_node_blockptr(parent, slot - 1); | |
2316 | gen = btrfs_node_ptr_generation(parent, slot - 1); | |
62d1f9fe | 2317 | eb = find_extent_buffer(root->fs_info, block1); |
b9fab919 CM |
2318 | /* |
2319 | * if we get -eagain from btrfs_buffer_uptodate, we | |
2320 | * don't want to return eagain here. That will loop | |
2321 | * forever | |
2322 | */ | |
2323 | if (eb && btrfs_buffer_uptodate(eb, gen, 1) != 0) | |
b4ce94de CM |
2324 | block1 = 0; |
2325 | free_extent_buffer(eb); | |
2326 | } | |
8c594ea8 | 2327 | if (slot + 1 < nritems) { |
b4ce94de CM |
2328 | block2 = btrfs_node_blockptr(parent, slot + 1); |
2329 | gen = btrfs_node_ptr_generation(parent, slot + 1); | |
62d1f9fe | 2330 | eb = find_extent_buffer(root->fs_info, block2); |
b9fab919 | 2331 | if (eb && btrfs_buffer_uptodate(eb, gen, 1) != 0) |
b4ce94de CM |
2332 | block2 = 0; |
2333 | free_extent_buffer(eb); | |
2334 | } | |
8c594ea8 | 2335 | |
0b08851f | 2336 | if (block1) |
d3e46fea | 2337 | readahead_tree_block(root, block1); |
0b08851f | 2338 | if (block2) |
d3e46fea | 2339 | readahead_tree_block(root, block2); |
b4ce94de CM |
2340 | } |
2341 | ||
2342 | ||
d352ac68 | 2343 | /* |
d397712b CM |
2344 | * when we walk down the tree, it is usually safe to unlock the higher layers |
2345 | * in the tree. The exceptions are when our path goes through slot 0, because | |
2346 | * operations on the tree might require changing key pointers higher up in the | |
2347 | * tree. | |
d352ac68 | 2348 | * |
d397712b CM |
2349 | * callers might also have set path->keep_locks, which tells this code to keep |
2350 | * the lock if the path points to the last slot in the block. This is part of | |
2351 | * walking through the tree, and selecting the next slot in the higher block. | |
d352ac68 | 2352 | * |
d397712b CM |
2353 | * lowest_unlock sets the lowest level in the tree we're allowed to unlock. so |
2354 | * if lowest_unlock is 1, level 0 won't be unlocked | |
d352ac68 | 2355 | */ |
e02119d5 | 2356 | static noinline void unlock_up(struct btrfs_path *path, int level, |
f7c79f30 CM |
2357 | int lowest_unlock, int min_write_lock_level, |
2358 | int *write_lock_level) | |
925baedd CM |
2359 | { |
2360 | int i; | |
2361 | int skip_level = level; | |
051e1b9f | 2362 | int no_skips = 0; |
925baedd CM |
2363 | struct extent_buffer *t; |
2364 | ||
2365 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { | |
2366 | if (!path->nodes[i]) | |
2367 | break; | |
2368 | if (!path->locks[i]) | |
2369 | break; | |
051e1b9f | 2370 | if (!no_skips && path->slots[i] == 0) { |
925baedd CM |
2371 | skip_level = i + 1; |
2372 | continue; | |
2373 | } | |
051e1b9f | 2374 | if (!no_skips && path->keep_locks) { |
925baedd CM |
2375 | u32 nritems; |
2376 | t = path->nodes[i]; | |
2377 | nritems = btrfs_header_nritems(t); | |
051e1b9f | 2378 | if (nritems < 1 || path->slots[i] >= nritems - 1) { |
925baedd CM |
2379 | skip_level = i + 1; |
2380 | continue; | |
2381 | } | |
2382 | } | |
051e1b9f CM |
2383 | if (skip_level < i && i >= lowest_unlock) |
2384 | no_skips = 1; | |
2385 | ||
925baedd CM |
2386 | t = path->nodes[i]; |
2387 | if (i >= lowest_unlock && i > skip_level && path->locks[i]) { | |
bd681513 | 2388 | btrfs_tree_unlock_rw(t, path->locks[i]); |
925baedd | 2389 | path->locks[i] = 0; |
f7c79f30 CM |
2390 | if (write_lock_level && |
2391 | i > min_write_lock_level && | |
2392 | i <= *write_lock_level) { | |
2393 | *write_lock_level = i - 1; | |
2394 | } | |
925baedd CM |
2395 | } |
2396 | } | |
2397 | } | |
2398 | ||
b4ce94de CM |
2399 | /* |
2400 | * This releases any locks held in the path starting at level and | |
2401 | * going all the way up to the root. | |
2402 | * | |
2403 | * btrfs_search_slot will keep the lock held on higher nodes in a few | |
2404 | * corner cases, such as COW of the block at slot zero in the node. This | |
2405 | * ignores those rules, and it should only be called when there are no | |
2406 | * more updates to be done higher up in the tree. | |
2407 | */ | |
2408 | noinline void btrfs_unlock_up_safe(struct btrfs_path *path, int level) | |
2409 | { | |
2410 | int i; | |
2411 | ||
09a2a8f9 | 2412 | if (path->keep_locks) |
b4ce94de CM |
2413 | return; |
2414 | ||
2415 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { | |
2416 | if (!path->nodes[i]) | |
12f4dacc | 2417 | continue; |
b4ce94de | 2418 | if (!path->locks[i]) |
12f4dacc | 2419 | continue; |
bd681513 | 2420 | btrfs_tree_unlock_rw(path->nodes[i], path->locks[i]); |
b4ce94de CM |
2421 | path->locks[i] = 0; |
2422 | } | |
2423 | } | |
2424 | ||
c8c42864 CM |
2425 | /* |
2426 | * helper function for btrfs_search_slot. The goal is to find a block | |
2427 | * in cache without setting the path to blocking. If we find the block | |
2428 | * we return zero and the path is unchanged. | |
2429 | * | |
2430 | * If we can't find the block, we set the path blocking and do some | |
2431 | * reada. -EAGAIN is returned and the search must be repeated. | |
2432 | */ | |
2433 | static int | |
2434 | read_block_for_search(struct btrfs_trans_handle *trans, | |
2435 | struct btrfs_root *root, struct btrfs_path *p, | |
2436 | struct extent_buffer **eb_ret, int level, int slot, | |
5d9e75c4 | 2437 | struct btrfs_key *key, u64 time_seq) |
c8c42864 CM |
2438 | { |
2439 | u64 blocknr; | |
2440 | u64 gen; | |
c8c42864 CM |
2441 | struct extent_buffer *b = *eb_ret; |
2442 | struct extent_buffer *tmp; | |
76a05b35 | 2443 | int ret; |
c8c42864 CM |
2444 | |
2445 | blocknr = btrfs_node_blockptr(b, slot); | |
2446 | gen = btrfs_node_ptr_generation(b, slot); | |
c8c42864 | 2447 | |
62d1f9fe | 2448 | tmp = find_extent_buffer(root->fs_info, blocknr); |
cb44921a | 2449 | if (tmp) { |
b9fab919 | 2450 | /* first we do an atomic uptodate check */ |
bdf7c00e JB |
2451 | if (btrfs_buffer_uptodate(tmp, gen, 1) > 0) { |
2452 | *eb_ret = tmp; | |
2453 | return 0; | |
2454 | } | |
2455 | ||
2456 | /* the pages were up to date, but we failed | |
2457 | * the generation number check. Do a full | |
2458 | * read for the generation number that is correct. | |
2459 | * We must do this without dropping locks so | |
2460 | * we can trust our generation number | |
2461 | */ | |
2462 | btrfs_set_path_blocking(p); | |
2463 | ||
2464 | /* now we're allowed to do a blocking uptodate check */ | |
2465 | ret = btrfs_read_buffer(tmp, gen); | |
2466 | if (!ret) { | |
2467 | *eb_ret = tmp; | |
2468 | return 0; | |
cb44921a | 2469 | } |
bdf7c00e JB |
2470 | free_extent_buffer(tmp); |
2471 | btrfs_release_path(p); | |
2472 | return -EIO; | |
c8c42864 CM |
2473 | } |
2474 | ||
2475 | /* | |
2476 | * reduce lock contention at high levels | |
2477 | * of the btree by dropping locks before | |
76a05b35 CM |
2478 | * we read. Don't release the lock on the current |
2479 | * level because we need to walk this node to figure | |
2480 | * out which blocks to read. | |
c8c42864 | 2481 | */ |
8c594ea8 CM |
2482 | btrfs_unlock_up_safe(p, level + 1); |
2483 | btrfs_set_path_blocking(p); | |
2484 | ||
cb44921a | 2485 | free_extent_buffer(tmp); |
e4058b54 | 2486 | if (p->reada != READA_NONE) |
c8c42864 CM |
2487 | reada_for_search(root, p, level, slot, key->objectid); |
2488 | ||
b3b4aa74 | 2489 | btrfs_release_path(p); |
76a05b35 CM |
2490 | |
2491 | ret = -EAGAIN; | |
ce86cd59 | 2492 | tmp = read_tree_block(root, blocknr, 0); |
64c043de | 2493 | if (!IS_ERR(tmp)) { |
76a05b35 CM |
2494 | /* |
2495 | * If the read above didn't mark this buffer up to date, | |
2496 | * it will never end up being up to date. Set ret to EIO now | |
2497 | * and give up so that our caller doesn't loop forever | |
2498 | * on our EAGAINs. | |
2499 | */ | |
b9fab919 | 2500 | if (!btrfs_buffer_uptodate(tmp, 0, 0)) |
76a05b35 | 2501 | ret = -EIO; |
c8c42864 | 2502 | free_extent_buffer(tmp); |
c871b0f2 LB |
2503 | } else { |
2504 | ret = PTR_ERR(tmp); | |
76a05b35 CM |
2505 | } |
2506 | return ret; | |
c8c42864 CM |
2507 | } |
2508 | ||
2509 | /* | |
2510 | * helper function for btrfs_search_slot. This does all of the checks | |
2511 | * for node-level blocks and does any balancing required based on | |
2512 | * the ins_len. | |
2513 | * | |
2514 | * If no extra work was required, zero is returned. If we had to | |
2515 | * drop the path, -EAGAIN is returned and btrfs_search_slot must | |
2516 | * start over | |
2517 | */ | |
2518 | static int | |
2519 | setup_nodes_for_search(struct btrfs_trans_handle *trans, | |
2520 | struct btrfs_root *root, struct btrfs_path *p, | |
bd681513 CM |
2521 | struct extent_buffer *b, int level, int ins_len, |
2522 | int *write_lock_level) | |
c8c42864 CM |
2523 | { |
2524 | int ret; | |
2525 | if ((p->search_for_split || ins_len > 0) && btrfs_header_nritems(b) >= | |
2526 | BTRFS_NODEPTRS_PER_BLOCK(root) - 3) { | |
2527 | int sret; | |
2528 | ||
bd681513 CM |
2529 | if (*write_lock_level < level + 1) { |
2530 | *write_lock_level = level + 1; | |
2531 | btrfs_release_path(p); | |
2532 | goto again; | |
2533 | } | |
2534 | ||
c8c42864 | 2535 | btrfs_set_path_blocking(p); |
0b08851f | 2536 | reada_for_balance(root, p, level); |
c8c42864 | 2537 | sret = split_node(trans, root, p, level); |
bd681513 | 2538 | btrfs_clear_path_blocking(p, NULL, 0); |
c8c42864 CM |
2539 | |
2540 | BUG_ON(sret > 0); | |
2541 | if (sret) { | |
2542 | ret = sret; | |
2543 | goto done; | |
2544 | } | |
2545 | b = p->nodes[level]; | |
2546 | } else if (ins_len < 0 && btrfs_header_nritems(b) < | |
cfbb9308 | 2547 | BTRFS_NODEPTRS_PER_BLOCK(root) / 2) { |
c8c42864 CM |
2548 | int sret; |
2549 | ||
bd681513 CM |
2550 | if (*write_lock_level < level + 1) { |
2551 | *write_lock_level = level + 1; | |
2552 | btrfs_release_path(p); | |
2553 | goto again; | |
2554 | } | |
2555 | ||
c8c42864 | 2556 | btrfs_set_path_blocking(p); |
0b08851f | 2557 | reada_for_balance(root, p, level); |
c8c42864 | 2558 | sret = balance_level(trans, root, p, level); |
bd681513 | 2559 | btrfs_clear_path_blocking(p, NULL, 0); |
c8c42864 CM |
2560 | |
2561 | if (sret) { | |
2562 | ret = sret; | |
2563 | goto done; | |
2564 | } | |
2565 | b = p->nodes[level]; | |
2566 | if (!b) { | |
b3b4aa74 | 2567 | btrfs_release_path(p); |
c8c42864 CM |
2568 | goto again; |
2569 | } | |
2570 | BUG_ON(btrfs_header_nritems(b) == 1); | |
2571 | } | |
2572 | return 0; | |
2573 | ||
2574 | again: | |
2575 | ret = -EAGAIN; | |
2576 | done: | |
2577 | return ret; | |
2578 | } | |
2579 | ||
d7396f07 FDBM |
2580 | static void key_search_validate(struct extent_buffer *b, |
2581 | struct btrfs_key *key, | |
2582 | int level) | |
2583 | { | |
2584 | #ifdef CONFIG_BTRFS_ASSERT | |
2585 | struct btrfs_disk_key disk_key; | |
2586 | ||
2587 | btrfs_cpu_key_to_disk(&disk_key, key); | |
2588 | ||
2589 | if (level == 0) | |
2590 | ASSERT(!memcmp_extent_buffer(b, &disk_key, | |
2591 | offsetof(struct btrfs_leaf, items[0].key), | |
2592 | sizeof(disk_key))); | |
2593 | else | |
2594 | ASSERT(!memcmp_extent_buffer(b, &disk_key, | |
2595 | offsetof(struct btrfs_node, ptrs[0].key), | |
2596 | sizeof(disk_key))); | |
2597 | #endif | |
2598 | } | |
2599 | ||
2600 | static int key_search(struct extent_buffer *b, struct btrfs_key *key, | |
2601 | int level, int *prev_cmp, int *slot) | |
2602 | { | |
2603 | if (*prev_cmp != 0) { | |
2604 | *prev_cmp = bin_search(b, key, level, slot); | |
2605 | return *prev_cmp; | |
2606 | } | |
2607 | ||
2608 | key_search_validate(b, key, level); | |
2609 | *slot = 0; | |
2610 | ||
2611 | return 0; | |
2612 | } | |
2613 | ||
381cf658 | 2614 | int btrfs_find_item(struct btrfs_root *fs_root, struct btrfs_path *path, |
e33d5c3d KN |
2615 | u64 iobjectid, u64 ioff, u8 key_type, |
2616 | struct btrfs_key *found_key) | |
2617 | { | |
2618 | int ret; | |
2619 | struct btrfs_key key; | |
2620 | struct extent_buffer *eb; | |
381cf658 DS |
2621 | |
2622 | ASSERT(path); | |
1d4c08e0 | 2623 | ASSERT(found_key); |
e33d5c3d KN |
2624 | |
2625 | key.type = key_type; | |
2626 | key.objectid = iobjectid; | |
2627 | key.offset = ioff; | |
2628 | ||
2629 | ret = btrfs_search_slot(NULL, fs_root, &key, path, 0, 0); | |
1d4c08e0 | 2630 | if (ret < 0) |
e33d5c3d KN |
2631 | return ret; |
2632 | ||
2633 | eb = path->nodes[0]; | |
2634 | if (ret && path->slots[0] >= btrfs_header_nritems(eb)) { | |
2635 | ret = btrfs_next_leaf(fs_root, path); | |
2636 | if (ret) | |
2637 | return ret; | |
2638 | eb = path->nodes[0]; | |
2639 | } | |
2640 | ||
2641 | btrfs_item_key_to_cpu(eb, found_key, path->slots[0]); | |
2642 | if (found_key->type != key.type || | |
2643 | found_key->objectid != key.objectid) | |
2644 | return 1; | |
2645 | ||
2646 | return 0; | |
2647 | } | |
2648 | ||
74123bd7 CM |
2649 | /* |
2650 | * look for key in the tree. path is filled in with nodes along the way | |
2651 | * if key is found, we return zero and you can find the item in the leaf | |
2652 | * level of the path (level 0) | |
2653 | * | |
2654 | * If the key isn't found, the path points to the slot where it should | |
aa5d6bed CM |
2655 | * be inserted, and 1 is returned. If there are other errors during the |
2656 | * search a negative error number is returned. | |
97571fd0 CM |
2657 | * |
2658 | * if ins_len > 0, nodes and leaves will be split as we walk down the | |
2659 | * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if | |
2660 | * possible) | |
74123bd7 | 2661 | */ |
e089f05c CM |
2662 | int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root |
2663 | *root, struct btrfs_key *key, struct btrfs_path *p, int | |
2664 | ins_len, int cow) | |
be0e5c09 | 2665 | { |
5f39d397 | 2666 | struct extent_buffer *b; |
be0e5c09 CM |
2667 | int slot; |
2668 | int ret; | |
33c66f43 | 2669 | int err; |
be0e5c09 | 2670 | int level; |
925baedd | 2671 | int lowest_unlock = 1; |
bd681513 CM |
2672 | int root_lock; |
2673 | /* everything at write_lock_level or lower must be write locked */ | |
2674 | int write_lock_level = 0; | |
9f3a7427 | 2675 | u8 lowest_level = 0; |
f7c79f30 | 2676 | int min_write_lock_level; |
d7396f07 | 2677 | int prev_cmp; |
9f3a7427 | 2678 | |
6702ed49 | 2679 | lowest_level = p->lowest_level; |
323ac95b | 2680 | WARN_ON(lowest_level && ins_len > 0); |
22b0ebda | 2681 | WARN_ON(p->nodes[0] != NULL); |
eb653de1 | 2682 | BUG_ON(!cow && ins_len); |
25179201 | 2683 | |
bd681513 | 2684 | if (ins_len < 0) { |
925baedd | 2685 | lowest_unlock = 2; |
65b51a00 | 2686 | |
bd681513 CM |
2687 | /* when we are removing items, we might have to go up to level |
2688 | * two as we update tree pointers Make sure we keep write | |
2689 | * for those levels as well | |
2690 | */ | |
2691 | write_lock_level = 2; | |
2692 | } else if (ins_len > 0) { | |
2693 | /* | |
2694 | * for inserting items, make sure we have a write lock on | |
2695 | * level 1 so we can update keys | |
2696 | */ | |
2697 | write_lock_level = 1; | |
2698 | } | |
2699 | ||
2700 | if (!cow) | |
2701 | write_lock_level = -1; | |
2702 | ||
09a2a8f9 | 2703 | if (cow && (p->keep_locks || p->lowest_level)) |
bd681513 CM |
2704 | write_lock_level = BTRFS_MAX_LEVEL; |
2705 | ||
f7c79f30 CM |
2706 | min_write_lock_level = write_lock_level; |
2707 | ||
bb803951 | 2708 | again: |
d7396f07 | 2709 | prev_cmp = -1; |
bd681513 CM |
2710 | /* |
2711 | * we try very hard to do read locks on the root | |
2712 | */ | |
2713 | root_lock = BTRFS_READ_LOCK; | |
2714 | level = 0; | |
5d4f98a2 | 2715 | if (p->search_commit_root) { |
bd681513 CM |
2716 | /* |
2717 | * the commit roots are read only | |
2718 | * so we always do read locks | |
2719 | */ | |
3f8a18cc JB |
2720 | if (p->need_commit_sem) |
2721 | down_read(&root->fs_info->commit_root_sem); | |
5d4f98a2 YZ |
2722 | b = root->commit_root; |
2723 | extent_buffer_get(b); | |
bd681513 | 2724 | level = btrfs_header_level(b); |
3f8a18cc JB |
2725 | if (p->need_commit_sem) |
2726 | up_read(&root->fs_info->commit_root_sem); | |
5d4f98a2 | 2727 | if (!p->skip_locking) |
bd681513 | 2728 | btrfs_tree_read_lock(b); |
5d4f98a2 | 2729 | } else { |
bd681513 | 2730 | if (p->skip_locking) { |
5d4f98a2 | 2731 | b = btrfs_root_node(root); |
bd681513 CM |
2732 | level = btrfs_header_level(b); |
2733 | } else { | |
2734 | /* we don't know the level of the root node | |
2735 | * until we actually have it read locked | |
2736 | */ | |
2737 | b = btrfs_read_lock_root_node(root); | |
2738 | level = btrfs_header_level(b); | |
2739 | if (level <= write_lock_level) { | |
2740 | /* whoops, must trade for write lock */ | |
2741 | btrfs_tree_read_unlock(b); | |
2742 | free_extent_buffer(b); | |
2743 | b = btrfs_lock_root_node(root); | |
2744 | root_lock = BTRFS_WRITE_LOCK; | |
2745 | ||
2746 | /* the level might have changed, check again */ | |
2747 | level = btrfs_header_level(b); | |
2748 | } | |
2749 | } | |
5d4f98a2 | 2750 | } |
bd681513 CM |
2751 | p->nodes[level] = b; |
2752 | if (!p->skip_locking) | |
2753 | p->locks[level] = root_lock; | |
925baedd | 2754 | |
eb60ceac | 2755 | while (b) { |
5f39d397 | 2756 | level = btrfs_header_level(b); |
65b51a00 CM |
2757 | |
2758 | /* | |
2759 | * setup the path here so we can release it under lock | |
2760 | * contention with the cow code | |
2761 | */ | |
02217ed2 | 2762 | if (cow) { |
c8c42864 CM |
2763 | /* |
2764 | * if we don't really need to cow this block | |
2765 | * then we don't want to set the path blocking, | |
2766 | * so we test it here | |
2767 | */ | |
64c12921 JM |
2768 | if (!should_cow_block(trans, root, b)) { |
2769 | trans->dirty = true; | |
65b51a00 | 2770 | goto cow_done; |
64c12921 | 2771 | } |
5d4f98a2 | 2772 | |
bd681513 CM |
2773 | /* |
2774 | * must have write locks on this node and the | |
2775 | * parent | |
2776 | */ | |
5124e00e JB |
2777 | if (level > write_lock_level || |
2778 | (level + 1 > write_lock_level && | |
2779 | level + 1 < BTRFS_MAX_LEVEL && | |
2780 | p->nodes[level + 1])) { | |
bd681513 CM |
2781 | write_lock_level = level + 1; |
2782 | btrfs_release_path(p); | |
2783 | goto again; | |
2784 | } | |
2785 | ||
160f4089 | 2786 | btrfs_set_path_blocking(p); |
33c66f43 YZ |
2787 | err = btrfs_cow_block(trans, root, b, |
2788 | p->nodes[level + 1], | |
2789 | p->slots[level + 1], &b); | |
2790 | if (err) { | |
33c66f43 | 2791 | ret = err; |
65b51a00 | 2792 | goto done; |
54aa1f4d | 2793 | } |
02217ed2 | 2794 | } |
65b51a00 | 2795 | cow_done: |
eb60ceac | 2796 | p->nodes[level] = b; |
bd681513 | 2797 | btrfs_clear_path_blocking(p, NULL, 0); |
b4ce94de CM |
2798 | |
2799 | /* | |
2800 | * we have a lock on b and as long as we aren't changing | |
2801 | * the tree, there is no way to for the items in b to change. | |
2802 | * It is safe to drop the lock on our parent before we | |
2803 | * go through the expensive btree search on b. | |
2804 | * | |
eb653de1 FDBM |
2805 | * If we're inserting or deleting (ins_len != 0), then we might |
2806 | * be changing slot zero, which may require changing the parent. | |
2807 | * So, we can't drop the lock until after we know which slot | |
2808 | * we're operating on. | |
b4ce94de | 2809 | */ |
eb653de1 FDBM |
2810 | if (!ins_len && !p->keep_locks) { |
2811 | int u = level + 1; | |
2812 | ||
2813 | if (u < BTRFS_MAX_LEVEL && p->locks[u]) { | |
2814 | btrfs_tree_unlock_rw(p->nodes[u], p->locks[u]); | |
2815 | p->locks[u] = 0; | |
2816 | } | |
2817 | } | |
b4ce94de | 2818 | |
d7396f07 | 2819 | ret = key_search(b, key, level, &prev_cmp, &slot); |
415b35a5 LB |
2820 | if (ret < 0) |
2821 | goto done; | |
b4ce94de | 2822 | |
5f39d397 | 2823 | if (level != 0) { |
33c66f43 YZ |
2824 | int dec = 0; |
2825 | if (ret && slot > 0) { | |
2826 | dec = 1; | |
be0e5c09 | 2827 | slot -= 1; |
33c66f43 | 2828 | } |
be0e5c09 | 2829 | p->slots[level] = slot; |
33c66f43 | 2830 | err = setup_nodes_for_search(trans, root, p, b, level, |
bd681513 | 2831 | ins_len, &write_lock_level); |
33c66f43 | 2832 | if (err == -EAGAIN) |
c8c42864 | 2833 | goto again; |
33c66f43 YZ |
2834 | if (err) { |
2835 | ret = err; | |
c8c42864 | 2836 | goto done; |
33c66f43 | 2837 | } |
c8c42864 CM |
2838 | b = p->nodes[level]; |
2839 | slot = p->slots[level]; | |
b4ce94de | 2840 | |
bd681513 CM |
2841 | /* |
2842 | * slot 0 is special, if we change the key | |
2843 | * we have to update the parent pointer | |
2844 | * which means we must have a write lock | |
2845 | * on the parent | |
2846 | */ | |
eb653de1 | 2847 | if (slot == 0 && ins_len && |
bd681513 CM |
2848 | write_lock_level < level + 1) { |
2849 | write_lock_level = level + 1; | |
2850 | btrfs_release_path(p); | |
2851 | goto again; | |
2852 | } | |
2853 | ||
f7c79f30 CM |
2854 | unlock_up(p, level, lowest_unlock, |
2855 | min_write_lock_level, &write_lock_level); | |
f9efa9c7 | 2856 | |
925baedd | 2857 | if (level == lowest_level) { |
33c66f43 YZ |
2858 | if (dec) |
2859 | p->slots[level]++; | |
5b21f2ed | 2860 | goto done; |
925baedd | 2861 | } |
ca7a79ad | 2862 | |
33c66f43 | 2863 | err = read_block_for_search(trans, root, p, |
5d9e75c4 | 2864 | &b, level, slot, key, 0); |
33c66f43 | 2865 | if (err == -EAGAIN) |
c8c42864 | 2866 | goto again; |
33c66f43 YZ |
2867 | if (err) { |
2868 | ret = err; | |
76a05b35 | 2869 | goto done; |
33c66f43 | 2870 | } |
76a05b35 | 2871 | |
b4ce94de | 2872 | if (!p->skip_locking) { |
bd681513 CM |
2873 | level = btrfs_header_level(b); |
2874 | if (level <= write_lock_level) { | |
2875 | err = btrfs_try_tree_write_lock(b); | |
2876 | if (!err) { | |
2877 | btrfs_set_path_blocking(p); | |
2878 | btrfs_tree_lock(b); | |
2879 | btrfs_clear_path_blocking(p, b, | |
2880 | BTRFS_WRITE_LOCK); | |
2881 | } | |
2882 | p->locks[level] = BTRFS_WRITE_LOCK; | |
2883 | } else { | |
f82c458a | 2884 | err = btrfs_tree_read_lock_atomic(b); |
bd681513 CM |
2885 | if (!err) { |
2886 | btrfs_set_path_blocking(p); | |
2887 | btrfs_tree_read_lock(b); | |
2888 | btrfs_clear_path_blocking(p, b, | |
2889 | BTRFS_READ_LOCK); | |
2890 | } | |
2891 | p->locks[level] = BTRFS_READ_LOCK; | |
b4ce94de | 2892 | } |
bd681513 | 2893 | p->nodes[level] = b; |
b4ce94de | 2894 | } |
be0e5c09 CM |
2895 | } else { |
2896 | p->slots[level] = slot; | |
87b29b20 YZ |
2897 | if (ins_len > 0 && |
2898 | btrfs_leaf_free_space(root, b) < ins_len) { | |
bd681513 CM |
2899 | if (write_lock_level < 1) { |
2900 | write_lock_level = 1; | |
2901 | btrfs_release_path(p); | |
2902 | goto again; | |
2903 | } | |
2904 | ||
b4ce94de | 2905 | btrfs_set_path_blocking(p); |
33c66f43 YZ |
2906 | err = split_leaf(trans, root, key, |
2907 | p, ins_len, ret == 0); | |
bd681513 | 2908 | btrfs_clear_path_blocking(p, NULL, 0); |
b4ce94de | 2909 | |
33c66f43 YZ |
2910 | BUG_ON(err > 0); |
2911 | if (err) { | |
2912 | ret = err; | |
65b51a00 CM |
2913 | goto done; |
2914 | } | |
5c680ed6 | 2915 | } |
459931ec | 2916 | if (!p->search_for_split) |
f7c79f30 CM |
2917 | unlock_up(p, level, lowest_unlock, |
2918 | min_write_lock_level, &write_lock_level); | |
65b51a00 | 2919 | goto done; |
be0e5c09 CM |
2920 | } |
2921 | } | |
65b51a00 CM |
2922 | ret = 1; |
2923 | done: | |
b4ce94de CM |
2924 | /* |
2925 | * we don't really know what they plan on doing with the path | |
2926 | * from here on, so for now just mark it as blocking | |
2927 | */ | |
b9473439 CM |
2928 | if (!p->leave_spinning) |
2929 | btrfs_set_path_blocking(p); | |
5f5bc6b1 | 2930 | if (ret < 0 && !p->skip_release_on_error) |
b3b4aa74 | 2931 | btrfs_release_path(p); |
65b51a00 | 2932 | return ret; |
be0e5c09 CM |
2933 | } |
2934 | ||
5d9e75c4 JS |
2935 | /* |
2936 | * Like btrfs_search_slot, this looks for a key in the given tree. It uses the | |
2937 | * current state of the tree together with the operations recorded in the tree | |
2938 | * modification log to search for the key in a previous version of this tree, as | |
2939 | * denoted by the time_seq parameter. | |
2940 | * | |
2941 | * Naturally, there is no support for insert, delete or cow operations. | |
2942 | * | |
2943 | * The resulting path and return value will be set up as if we called | |
2944 | * btrfs_search_slot at that point in time with ins_len and cow both set to 0. | |
2945 | */ | |
2946 | int btrfs_search_old_slot(struct btrfs_root *root, struct btrfs_key *key, | |
2947 | struct btrfs_path *p, u64 time_seq) | |
2948 | { | |
2949 | struct extent_buffer *b; | |
2950 | int slot; | |
2951 | int ret; | |
2952 | int err; | |
2953 | int level; | |
2954 | int lowest_unlock = 1; | |
2955 | u8 lowest_level = 0; | |
d4b4087c | 2956 | int prev_cmp = -1; |
5d9e75c4 JS |
2957 | |
2958 | lowest_level = p->lowest_level; | |
2959 | WARN_ON(p->nodes[0] != NULL); | |
2960 | ||
2961 | if (p->search_commit_root) { | |
2962 | BUG_ON(time_seq); | |
2963 | return btrfs_search_slot(NULL, root, key, p, 0, 0); | |
2964 | } | |
2965 | ||
2966 | again: | |
5d9e75c4 | 2967 | b = get_old_root(root, time_seq); |
5d9e75c4 | 2968 | level = btrfs_header_level(b); |
5d9e75c4 JS |
2969 | p->locks[level] = BTRFS_READ_LOCK; |
2970 | ||
2971 | while (b) { | |
2972 | level = btrfs_header_level(b); | |
2973 | p->nodes[level] = b; | |
2974 | btrfs_clear_path_blocking(p, NULL, 0); | |
2975 | ||
2976 | /* | |
2977 | * we have a lock on b and as long as we aren't changing | |
2978 | * the tree, there is no way to for the items in b to change. | |
2979 | * It is safe to drop the lock on our parent before we | |
2980 | * go through the expensive btree search on b. | |
2981 | */ | |
2982 | btrfs_unlock_up_safe(p, level + 1); | |
2983 | ||
d4b4087c | 2984 | /* |
01327610 | 2985 | * Since we can unwind ebs we want to do a real search every |
d4b4087c JB |
2986 | * time. |
2987 | */ | |
2988 | prev_cmp = -1; | |
d7396f07 | 2989 | ret = key_search(b, key, level, &prev_cmp, &slot); |
5d9e75c4 JS |
2990 | |
2991 | if (level != 0) { | |
2992 | int dec = 0; | |
2993 | if (ret && slot > 0) { | |
2994 | dec = 1; | |
2995 | slot -= 1; | |
2996 | } | |
2997 | p->slots[level] = slot; | |
2998 | unlock_up(p, level, lowest_unlock, 0, NULL); | |
2999 | ||
3000 | if (level == lowest_level) { | |
3001 | if (dec) | |
3002 | p->slots[level]++; | |
3003 | goto done; | |
3004 | } | |
3005 | ||
3006 | err = read_block_for_search(NULL, root, p, &b, level, | |
3007 | slot, key, time_seq); | |
3008 | if (err == -EAGAIN) | |
3009 | goto again; | |
3010 | if (err) { | |
3011 | ret = err; | |
3012 | goto done; | |
3013 | } | |
3014 | ||
3015 | level = btrfs_header_level(b); | |
f82c458a | 3016 | err = btrfs_tree_read_lock_atomic(b); |
5d9e75c4 JS |
3017 | if (!err) { |
3018 | btrfs_set_path_blocking(p); | |
3019 | btrfs_tree_read_lock(b); | |
3020 | btrfs_clear_path_blocking(p, b, | |
3021 | BTRFS_READ_LOCK); | |
3022 | } | |
9ec72677 | 3023 | b = tree_mod_log_rewind(root->fs_info, p, b, time_seq); |
db7f3436 JB |
3024 | if (!b) { |
3025 | ret = -ENOMEM; | |
3026 | goto done; | |
3027 | } | |
5d9e75c4 JS |
3028 | p->locks[level] = BTRFS_READ_LOCK; |
3029 | p->nodes[level] = b; | |
5d9e75c4 JS |
3030 | } else { |
3031 | p->slots[level] = slot; | |
3032 | unlock_up(p, level, lowest_unlock, 0, NULL); | |
3033 | goto done; | |
3034 | } | |
3035 | } | |
3036 | ret = 1; | |
3037 | done: | |
3038 | if (!p->leave_spinning) | |
3039 | btrfs_set_path_blocking(p); | |
3040 | if (ret < 0) | |
3041 | btrfs_release_path(p); | |
3042 | ||
3043 | return ret; | |
3044 | } | |
3045 | ||
2f38b3e1 AJ |
3046 | /* |
3047 | * helper to use instead of search slot if no exact match is needed but | |
3048 | * instead the next or previous item should be returned. | |
3049 | * When find_higher is true, the next higher item is returned, the next lower | |
3050 | * otherwise. | |
3051 | * When return_any and find_higher are both true, and no higher item is found, | |
3052 | * return the next lower instead. | |
3053 | * When return_any is true and find_higher is false, and no lower item is found, | |
3054 | * return the next higher instead. | |
3055 | * It returns 0 if any item is found, 1 if none is found (tree empty), and | |
3056 | * < 0 on error | |
3057 | */ | |
3058 | int btrfs_search_slot_for_read(struct btrfs_root *root, | |
3059 | struct btrfs_key *key, struct btrfs_path *p, | |
3060 | int find_higher, int return_any) | |
3061 | { | |
3062 | int ret; | |
3063 | struct extent_buffer *leaf; | |
3064 | ||
3065 | again: | |
3066 | ret = btrfs_search_slot(NULL, root, key, p, 0, 0); | |
3067 | if (ret <= 0) | |
3068 | return ret; | |
3069 | /* | |
3070 | * a return value of 1 means the path is at the position where the | |
3071 | * item should be inserted. Normally this is the next bigger item, | |
3072 | * but in case the previous item is the last in a leaf, path points | |
3073 | * to the first free slot in the previous leaf, i.e. at an invalid | |
3074 | * item. | |
3075 | */ | |
3076 | leaf = p->nodes[0]; | |
3077 | ||
3078 | if (find_higher) { | |
3079 | if (p->slots[0] >= btrfs_header_nritems(leaf)) { | |
3080 | ret = btrfs_next_leaf(root, p); | |
3081 | if (ret <= 0) | |
3082 | return ret; | |
3083 | if (!return_any) | |
3084 | return 1; | |
3085 | /* | |
3086 | * no higher item found, return the next | |
3087 | * lower instead | |
3088 | */ | |
3089 | return_any = 0; | |
3090 | find_higher = 0; | |
3091 | btrfs_release_path(p); | |
3092 | goto again; | |
3093 | } | |
3094 | } else { | |
e6793769 AJ |
3095 | if (p->slots[0] == 0) { |
3096 | ret = btrfs_prev_leaf(root, p); | |
3097 | if (ret < 0) | |
3098 | return ret; | |
3099 | if (!ret) { | |
23c6bf6a FDBM |
3100 | leaf = p->nodes[0]; |
3101 | if (p->slots[0] == btrfs_header_nritems(leaf)) | |
3102 | p->slots[0]--; | |
e6793769 | 3103 | return 0; |
2f38b3e1 | 3104 | } |
e6793769 AJ |
3105 | if (!return_any) |
3106 | return 1; | |
3107 | /* | |
3108 | * no lower item found, return the next | |
3109 | * higher instead | |
3110 | */ | |
3111 | return_any = 0; | |
3112 | find_higher = 1; | |
3113 | btrfs_release_path(p); | |
3114 | goto again; | |
3115 | } else { | |
2f38b3e1 AJ |
3116 | --p->slots[0]; |
3117 | } | |
3118 | } | |
3119 | return 0; | |
3120 | } | |
3121 | ||
74123bd7 CM |
3122 | /* |
3123 | * adjust the pointers going up the tree, starting at level | |
3124 | * making sure the right key of each node is points to 'key'. | |
3125 | * This is used after shifting pointers to the left, so it stops | |
3126 | * fixing up pointers when a given leaf/node is not in slot 0 of the | |
3127 | * higher levels | |
aa5d6bed | 3128 | * |
74123bd7 | 3129 | */ |
b7a0365e DD |
3130 | static void fixup_low_keys(struct btrfs_fs_info *fs_info, |
3131 | struct btrfs_path *path, | |
143bede5 | 3132 | struct btrfs_disk_key *key, int level) |
be0e5c09 CM |
3133 | { |
3134 | int i; | |
5f39d397 CM |
3135 | struct extent_buffer *t; |
3136 | ||
234b63a0 | 3137 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { |
be0e5c09 | 3138 | int tslot = path->slots[i]; |
eb60ceac | 3139 | if (!path->nodes[i]) |
be0e5c09 | 3140 | break; |
5f39d397 | 3141 | t = path->nodes[i]; |
b7a0365e | 3142 | tree_mod_log_set_node_key(fs_info, t, tslot, 1); |
5f39d397 | 3143 | btrfs_set_node_key(t, key, tslot); |
d6025579 | 3144 | btrfs_mark_buffer_dirty(path->nodes[i]); |
be0e5c09 CM |
3145 | if (tslot != 0) |
3146 | break; | |
3147 | } | |
3148 | } | |
3149 | ||
31840ae1 ZY |
3150 | /* |
3151 | * update item key. | |
3152 | * | |
3153 | * This function isn't completely safe. It's the caller's responsibility | |
3154 | * that the new key won't break the order | |
3155 | */ | |
b7a0365e DD |
3156 | void btrfs_set_item_key_safe(struct btrfs_fs_info *fs_info, |
3157 | struct btrfs_path *path, | |
143bede5 | 3158 | struct btrfs_key *new_key) |
31840ae1 ZY |
3159 | { |
3160 | struct btrfs_disk_key disk_key; | |
3161 | struct extent_buffer *eb; | |
3162 | int slot; | |
3163 | ||
3164 | eb = path->nodes[0]; | |
3165 | slot = path->slots[0]; | |
3166 | if (slot > 0) { | |
3167 | btrfs_item_key(eb, &disk_key, slot - 1); | |
143bede5 | 3168 | BUG_ON(comp_keys(&disk_key, new_key) >= 0); |
31840ae1 ZY |
3169 | } |
3170 | if (slot < btrfs_header_nritems(eb) - 1) { | |
3171 | btrfs_item_key(eb, &disk_key, slot + 1); | |
143bede5 | 3172 | BUG_ON(comp_keys(&disk_key, new_key) <= 0); |
31840ae1 ZY |
3173 | } |
3174 | ||
3175 | btrfs_cpu_key_to_disk(&disk_key, new_key); | |
3176 | btrfs_set_item_key(eb, &disk_key, slot); | |
3177 | btrfs_mark_buffer_dirty(eb); | |
3178 | if (slot == 0) | |
b7a0365e | 3179 | fixup_low_keys(fs_info, path, &disk_key, 1); |
31840ae1 ZY |
3180 | } |
3181 | ||
74123bd7 CM |
3182 | /* |
3183 | * try to push data from one node into the next node left in the | |
79f95c82 | 3184 | * tree. |
aa5d6bed CM |
3185 | * |
3186 | * returns 0 if some ptrs were pushed left, < 0 if there was some horrible | |
3187 | * error, and > 0 if there was no room in the left hand block. | |
74123bd7 | 3188 | */ |
98ed5174 CM |
3189 | static int push_node_left(struct btrfs_trans_handle *trans, |
3190 | struct btrfs_root *root, struct extent_buffer *dst, | |
971a1f66 | 3191 | struct extent_buffer *src, int empty) |
be0e5c09 | 3192 | { |
be0e5c09 | 3193 | int push_items = 0; |
bb803951 CM |
3194 | int src_nritems; |
3195 | int dst_nritems; | |
aa5d6bed | 3196 | int ret = 0; |
be0e5c09 | 3197 | |
5f39d397 CM |
3198 | src_nritems = btrfs_header_nritems(src); |
3199 | dst_nritems = btrfs_header_nritems(dst); | |
123abc88 | 3200 | push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems; |
7bb86316 CM |
3201 | WARN_ON(btrfs_header_generation(src) != trans->transid); |
3202 | WARN_ON(btrfs_header_generation(dst) != trans->transid); | |
54aa1f4d | 3203 | |
bce4eae9 | 3204 | if (!empty && src_nritems <= 8) |
971a1f66 CM |
3205 | return 1; |
3206 | ||
d397712b | 3207 | if (push_items <= 0) |
be0e5c09 CM |
3208 | return 1; |
3209 | ||
bce4eae9 | 3210 | if (empty) { |
971a1f66 | 3211 | push_items = min(src_nritems, push_items); |
bce4eae9 CM |
3212 | if (push_items < src_nritems) { |
3213 | /* leave at least 8 pointers in the node if | |
3214 | * we aren't going to empty it | |
3215 | */ | |
3216 | if (src_nritems - push_items < 8) { | |
3217 | if (push_items <= 8) | |
3218 | return 1; | |
3219 | push_items -= 8; | |
3220 | } | |
3221 | } | |
3222 | } else | |
3223 | push_items = min(src_nritems - 8, push_items); | |
79f95c82 | 3224 | |
5de865ee FDBM |
3225 | ret = tree_mod_log_eb_copy(root->fs_info, dst, src, dst_nritems, 0, |
3226 | push_items); | |
3227 | if (ret) { | |
66642832 | 3228 | btrfs_abort_transaction(trans, ret); |
5de865ee FDBM |
3229 | return ret; |
3230 | } | |
5f39d397 CM |
3231 | copy_extent_buffer(dst, src, |
3232 | btrfs_node_key_ptr_offset(dst_nritems), | |
3233 | btrfs_node_key_ptr_offset(0), | |
d397712b | 3234 | push_items * sizeof(struct btrfs_key_ptr)); |
5f39d397 | 3235 | |
bb803951 | 3236 | if (push_items < src_nritems) { |
57911b8b JS |
3237 | /* |
3238 | * don't call tree_mod_log_eb_move here, key removal was already | |
3239 | * fully logged by tree_mod_log_eb_copy above. | |
3240 | */ | |
5f39d397 CM |
3241 | memmove_extent_buffer(src, btrfs_node_key_ptr_offset(0), |
3242 | btrfs_node_key_ptr_offset(push_items), | |
3243 | (src_nritems - push_items) * | |
3244 | sizeof(struct btrfs_key_ptr)); | |
3245 | } | |
3246 | btrfs_set_header_nritems(src, src_nritems - push_items); | |
3247 | btrfs_set_header_nritems(dst, dst_nritems + push_items); | |
3248 | btrfs_mark_buffer_dirty(src); | |
3249 | btrfs_mark_buffer_dirty(dst); | |
31840ae1 | 3250 | |
79f95c82 CM |
3251 | return ret; |
3252 | } | |
3253 | ||
3254 | /* | |
3255 | * try to push data from one node into the next node right in the | |
3256 | * tree. | |
3257 | * | |
3258 | * returns 0 if some ptrs were pushed, < 0 if there was some horrible | |
3259 | * error, and > 0 if there was no room in the right hand block. | |
3260 | * | |
3261 | * this will only push up to 1/2 the contents of the left node over | |
3262 | */ | |
5f39d397 CM |
3263 | static int balance_node_right(struct btrfs_trans_handle *trans, |
3264 | struct btrfs_root *root, | |
3265 | struct extent_buffer *dst, | |
3266 | struct extent_buffer *src) | |
79f95c82 | 3267 | { |
79f95c82 CM |
3268 | int push_items = 0; |
3269 | int max_push; | |
3270 | int src_nritems; | |
3271 | int dst_nritems; | |
3272 | int ret = 0; | |
79f95c82 | 3273 | |
7bb86316 CM |
3274 | WARN_ON(btrfs_header_generation(src) != trans->transid); |
3275 | WARN_ON(btrfs_header_generation(dst) != trans->transid); | |
3276 | ||
5f39d397 CM |
3277 | src_nritems = btrfs_header_nritems(src); |
3278 | dst_nritems = btrfs_header_nritems(dst); | |
123abc88 | 3279 | push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems; |
d397712b | 3280 | if (push_items <= 0) |
79f95c82 | 3281 | return 1; |
bce4eae9 | 3282 | |
d397712b | 3283 | if (src_nritems < 4) |
bce4eae9 | 3284 | return 1; |
79f95c82 CM |
3285 | |
3286 | max_push = src_nritems / 2 + 1; | |
3287 | /* don't try to empty the node */ | |
d397712b | 3288 | if (max_push >= src_nritems) |
79f95c82 | 3289 | return 1; |
252c38f0 | 3290 | |
79f95c82 CM |
3291 | if (max_push < push_items) |
3292 | push_items = max_push; | |
3293 | ||
f230475e | 3294 | tree_mod_log_eb_move(root->fs_info, dst, push_items, 0, dst_nritems); |
5f39d397 CM |
3295 | memmove_extent_buffer(dst, btrfs_node_key_ptr_offset(push_items), |
3296 | btrfs_node_key_ptr_offset(0), | |
3297 | (dst_nritems) * | |
3298 | sizeof(struct btrfs_key_ptr)); | |
d6025579 | 3299 | |
5de865ee FDBM |
3300 | ret = tree_mod_log_eb_copy(root->fs_info, dst, src, 0, |
3301 | src_nritems - push_items, push_items); | |
3302 | if (ret) { | |
66642832 | 3303 | btrfs_abort_transaction(trans, ret); |
5de865ee FDBM |
3304 | return ret; |
3305 | } | |
5f39d397 CM |
3306 | copy_extent_buffer(dst, src, |
3307 | btrfs_node_key_ptr_offset(0), | |
3308 | btrfs_node_key_ptr_offset(src_nritems - push_items), | |
d397712b | 3309 | push_items * sizeof(struct btrfs_key_ptr)); |
79f95c82 | 3310 | |
5f39d397 CM |
3311 | btrfs_set_header_nritems(src, src_nritems - push_items); |
3312 | btrfs_set_header_nritems(dst, dst_nritems + push_items); | |
79f95c82 | 3313 | |
5f39d397 CM |
3314 | btrfs_mark_buffer_dirty(src); |
3315 | btrfs_mark_buffer_dirty(dst); | |
31840ae1 | 3316 | |
aa5d6bed | 3317 | return ret; |
be0e5c09 CM |
3318 | } |
3319 | ||
97571fd0 CM |
3320 | /* |
3321 | * helper function to insert a new root level in the tree. | |
3322 | * A new node is allocated, and a single item is inserted to | |
3323 | * point to the existing root | |
aa5d6bed CM |
3324 | * |
3325 | * returns zero on success or < 0 on failure. | |
97571fd0 | 3326 | */ |
d397712b | 3327 | static noinline int insert_new_root(struct btrfs_trans_handle *trans, |
5f39d397 | 3328 | struct btrfs_root *root, |
fdd99c72 | 3329 | struct btrfs_path *path, int level) |
5c680ed6 | 3330 | { |
7bb86316 | 3331 | u64 lower_gen; |
5f39d397 CM |
3332 | struct extent_buffer *lower; |
3333 | struct extent_buffer *c; | |
925baedd | 3334 | struct extent_buffer *old; |
5f39d397 | 3335 | struct btrfs_disk_key lower_key; |
5c680ed6 CM |
3336 | |
3337 | BUG_ON(path->nodes[level]); | |
3338 | BUG_ON(path->nodes[level-1] != root->node); | |
3339 | ||
7bb86316 CM |
3340 | lower = path->nodes[level-1]; |
3341 | if (level == 1) | |
3342 | btrfs_item_key(lower, &lower_key, 0); | |
3343 | else | |
3344 | btrfs_node_key(lower, &lower_key, 0); | |
3345 | ||
4d75f8a9 DS |
3346 | c = btrfs_alloc_tree_block(trans, root, 0, root->root_key.objectid, |
3347 | &lower_key, level, root->node->start, 0); | |
5f39d397 CM |
3348 | if (IS_ERR(c)) |
3349 | return PTR_ERR(c); | |
925baedd | 3350 | |
f0486c68 YZ |
3351 | root_add_used(root, root->nodesize); |
3352 | ||
5d4f98a2 | 3353 | memset_extent_buffer(c, 0, 0, sizeof(struct btrfs_header)); |
5f39d397 CM |
3354 | btrfs_set_header_nritems(c, 1); |
3355 | btrfs_set_header_level(c, level); | |
db94535d | 3356 | btrfs_set_header_bytenr(c, c->start); |
5f39d397 | 3357 | btrfs_set_header_generation(c, trans->transid); |
5d4f98a2 | 3358 | btrfs_set_header_backref_rev(c, BTRFS_MIXED_BACKREF_REV); |
5f39d397 | 3359 | btrfs_set_header_owner(c, root->root_key.objectid); |
5f39d397 | 3360 | |
0a4e5586 | 3361 | write_extent_buffer(c, root->fs_info->fsid, btrfs_header_fsid(), |
5f39d397 | 3362 | BTRFS_FSID_SIZE); |
e17cade2 CM |
3363 | |
3364 | write_extent_buffer(c, root->fs_info->chunk_tree_uuid, | |
b308bc2f | 3365 | btrfs_header_chunk_tree_uuid(c), BTRFS_UUID_SIZE); |
e17cade2 | 3366 | |
5f39d397 | 3367 | btrfs_set_node_key(c, &lower_key, 0); |
db94535d | 3368 | btrfs_set_node_blockptr(c, 0, lower->start); |
7bb86316 | 3369 | lower_gen = btrfs_header_generation(lower); |
31840ae1 | 3370 | WARN_ON(lower_gen != trans->transid); |
7bb86316 CM |
3371 | |
3372 | btrfs_set_node_ptr_generation(c, 0, lower_gen); | |
d5719762 | 3373 | |
5f39d397 | 3374 | btrfs_mark_buffer_dirty(c); |
d5719762 | 3375 | |
925baedd | 3376 | old = root->node; |
fdd99c72 | 3377 | tree_mod_log_set_root_pointer(root, c, 0); |
240f62c8 | 3378 | rcu_assign_pointer(root->node, c); |
925baedd CM |
3379 | |
3380 | /* the super has an extra ref to root->node */ | |
3381 | free_extent_buffer(old); | |
3382 | ||
0b86a832 | 3383 | add_root_to_dirty_list(root); |
5f39d397 CM |
3384 | extent_buffer_get(c); |
3385 | path->nodes[level] = c; | |
95449a16 | 3386 | path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING; |
5c680ed6 CM |
3387 | path->slots[level] = 0; |
3388 | return 0; | |
3389 | } | |
3390 | ||
74123bd7 CM |
3391 | /* |
3392 | * worker function to insert a single pointer in a node. | |
3393 | * the node should have enough room for the pointer already | |
97571fd0 | 3394 | * |
74123bd7 CM |
3395 | * slot and level indicate where you want the key to go, and |
3396 | * blocknr is the block the key points to. | |
3397 | */ | |
143bede5 JM |
3398 | static void insert_ptr(struct btrfs_trans_handle *trans, |
3399 | struct btrfs_root *root, struct btrfs_path *path, | |
3400 | struct btrfs_disk_key *key, u64 bytenr, | |
c3e06965 | 3401 | int slot, int level) |
74123bd7 | 3402 | { |
5f39d397 | 3403 | struct extent_buffer *lower; |
74123bd7 | 3404 | int nritems; |
f3ea38da | 3405 | int ret; |
5c680ed6 CM |
3406 | |
3407 | BUG_ON(!path->nodes[level]); | |
f0486c68 | 3408 | btrfs_assert_tree_locked(path->nodes[level]); |
5f39d397 CM |
3409 | lower = path->nodes[level]; |
3410 | nritems = btrfs_header_nritems(lower); | |
c293498b | 3411 | BUG_ON(slot > nritems); |
143bede5 | 3412 | BUG_ON(nritems == BTRFS_NODEPTRS_PER_BLOCK(root)); |
74123bd7 | 3413 | if (slot != nritems) { |
c3e06965 | 3414 | if (level) |
f3ea38da JS |
3415 | tree_mod_log_eb_move(root->fs_info, lower, slot + 1, |
3416 | slot, nritems - slot); | |
5f39d397 CM |
3417 | memmove_extent_buffer(lower, |
3418 | btrfs_node_key_ptr_offset(slot + 1), | |
3419 | btrfs_node_key_ptr_offset(slot), | |
d6025579 | 3420 | (nritems - slot) * sizeof(struct btrfs_key_ptr)); |
74123bd7 | 3421 | } |
c3e06965 | 3422 | if (level) { |
f3ea38da | 3423 | ret = tree_mod_log_insert_key(root->fs_info, lower, slot, |
c8cc6341 | 3424 | MOD_LOG_KEY_ADD, GFP_NOFS); |
f3ea38da JS |
3425 | BUG_ON(ret < 0); |
3426 | } | |
5f39d397 | 3427 | btrfs_set_node_key(lower, key, slot); |
db94535d | 3428 | btrfs_set_node_blockptr(lower, slot, bytenr); |
74493f7a CM |
3429 | WARN_ON(trans->transid == 0); |
3430 | btrfs_set_node_ptr_generation(lower, slot, trans->transid); | |
5f39d397 CM |
3431 | btrfs_set_header_nritems(lower, nritems + 1); |
3432 | btrfs_mark_buffer_dirty(lower); | |
74123bd7 CM |
3433 | } |
3434 | ||
97571fd0 CM |
3435 | /* |
3436 | * split the node at the specified level in path in two. | |
3437 | * The path is corrected to point to the appropriate node after the split | |
3438 | * | |
3439 | * Before splitting this tries to make some room in the node by pushing | |
3440 | * left and right, if either one works, it returns right away. | |
aa5d6bed CM |
3441 | * |
3442 | * returns 0 on success and < 0 on failure | |
97571fd0 | 3443 | */ |
e02119d5 CM |
3444 | static noinline int split_node(struct btrfs_trans_handle *trans, |
3445 | struct btrfs_root *root, | |
3446 | struct btrfs_path *path, int level) | |
be0e5c09 | 3447 | { |
5f39d397 CM |
3448 | struct extent_buffer *c; |
3449 | struct extent_buffer *split; | |
3450 | struct btrfs_disk_key disk_key; | |
be0e5c09 | 3451 | int mid; |
5c680ed6 | 3452 | int ret; |
7518a238 | 3453 | u32 c_nritems; |
eb60ceac | 3454 | |
5f39d397 | 3455 | c = path->nodes[level]; |
7bb86316 | 3456 | WARN_ON(btrfs_header_generation(c) != trans->transid); |
5f39d397 | 3457 | if (c == root->node) { |
d9abbf1c | 3458 | /* |
90f8d62e JS |
3459 | * trying to split the root, lets make a new one |
3460 | * | |
fdd99c72 | 3461 | * tree mod log: We don't log_removal old root in |
90f8d62e JS |
3462 | * insert_new_root, because that root buffer will be kept as a |
3463 | * normal node. We are going to log removal of half of the | |
3464 | * elements below with tree_mod_log_eb_copy. We're holding a | |
3465 | * tree lock on the buffer, which is why we cannot race with | |
3466 | * other tree_mod_log users. | |
d9abbf1c | 3467 | */ |
fdd99c72 | 3468 | ret = insert_new_root(trans, root, path, level + 1); |
5c680ed6 CM |
3469 | if (ret) |
3470 | return ret; | |
b3612421 | 3471 | } else { |
e66f709b | 3472 | ret = push_nodes_for_insert(trans, root, path, level); |
5f39d397 CM |
3473 | c = path->nodes[level]; |
3474 | if (!ret && btrfs_header_nritems(c) < | |
c448acf0 | 3475 | BTRFS_NODEPTRS_PER_BLOCK(root) - 3) |
e66f709b | 3476 | return 0; |
54aa1f4d CM |
3477 | if (ret < 0) |
3478 | return ret; | |
be0e5c09 | 3479 | } |
e66f709b | 3480 | |
5f39d397 | 3481 | c_nritems = btrfs_header_nritems(c); |
5d4f98a2 YZ |
3482 | mid = (c_nritems + 1) / 2; |
3483 | btrfs_node_key(c, &disk_key, mid); | |
7bb86316 | 3484 | |
4d75f8a9 DS |
3485 | split = btrfs_alloc_tree_block(trans, root, 0, root->root_key.objectid, |
3486 | &disk_key, level, c->start, 0); | |
5f39d397 CM |
3487 | if (IS_ERR(split)) |
3488 | return PTR_ERR(split); | |
3489 | ||
f0486c68 YZ |
3490 | root_add_used(root, root->nodesize); |
3491 | ||
5d4f98a2 | 3492 | memset_extent_buffer(split, 0, 0, sizeof(struct btrfs_header)); |
5f39d397 | 3493 | btrfs_set_header_level(split, btrfs_header_level(c)); |
db94535d | 3494 | btrfs_set_header_bytenr(split, split->start); |
5f39d397 | 3495 | btrfs_set_header_generation(split, trans->transid); |
5d4f98a2 | 3496 | btrfs_set_header_backref_rev(split, BTRFS_MIXED_BACKREF_REV); |
5f39d397 CM |
3497 | btrfs_set_header_owner(split, root->root_key.objectid); |
3498 | write_extent_buffer(split, root->fs_info->fsid, | |
0a4e5586 | 3499 | btrfs_header_fsid(), BTRFS_FSID_SIZE); |
e17cade2 | 3500 | write_extent_buffer(split, root->fs_info->chunk_tree_uuid, |
b308bc2f | 3501 | btrfs_header_chunk_tree_uuid(split), |
e17cade2 | 3502 | BTRFS_UUID_SIZE); |
54aa1f4d | 3503 | |
5de865ee FDBM |
3504 | ret = tree_mod_log_eb_copy(root->fs_info, split, c, 0, |
3505 | mid, c_nritems - mid); | |
3506 | if (ret) { | |
66642832 | 3507 | btrfs_abort_transaction(trans, ret); |
5de865ee FDBM |
3508 | return ret; |
3509 | } | |
5f39d397 CM |
3510 | copy_extent_buffer(split, c, |
3511 | btrfs_node_key_ptr_offset(0), | |
3512 | btrfs_node_key_ptr_offset(mid), | |
3513 | (c_nritems - mid) * sizeof(struct btrfs_key_ptr)); | |
3514 | btrfs_set_header_nritems(split, c_nritems - mid); | |
3515 | btrfs_set_header_nritems(c, mid); | |
aa5d6bed CM |
3516 | ret = 0; |
3517 | ||
5f39d397 CM |
3518 | btrfs_mark_buffer_dirty(c); |
3519 | btrfs_mark_buffer_dirty(split); | |
3520 | ||
143bede5 | 3521 | insert_ptr(trans, root, path, &disk_key, split->start, |
c3e06965 | 3522 | path->slots[level + 1] + 1, level + 1); |
aa5d6bed | 3523 | |
5de08d7d | 3524 | if (path->slots[level] >= mid) { |
5c680ed6 | 3525 | path->slots[level] -= mid; |
925baedd | 3526 | btrfs_tree_unlock(c); |
5f39d397 CM |
3527 | free_extent_buffer(c); |
3528 | path->nodes[level] = split; | |
5c680ed6 CM |
3529 | path->slots[level + 1] += 1; |
3530 | } else { | |
925baedd | 3531 | btrfs_tree_unlock(split); |
5f39d397 | 3532 | free_extent_buffer(split); |
be0e5c09 | 3533 | } |
aa5d6bed | 3534 | return ret; |
be0e5c09 CM |
3535 | } |
3536 | ||
74123bd7 CM |
3537 | /* |
3538 | * how many bytes are required to store the items in a leaf. start | |
3539 | * and nr indicate which items in the leaf to check. This totals up the | |
3540 | * space used both by the item structs and the item data | |
3541 | */ | |
5f39d397 | 3542 | static int leaf_space_used(struct extent_buffer *l, int start, int nr) |
be0e5c09 | 3543 | { |
41be1f3b JB |
3544 | struct btrfs_item *start_item; |
3545 | struct btrfs_item *end_item; | |
3546 | struct btrfs_map_token token; | |
be0e5c09 | 3547 | int data_len; |
5f39d397 | 3548 | int nritems = btrfs_header_nritems(l); |
d4dbff95 | 3549 | int end = min(nritems, start + nr) - 1; |
be0e5c09 CM |
3550 | |
3551 | if (!nr) | |
3552 | return 0; | |
41be1f3b | 3553 | btrfs_init_map_token(&token); |
dd3cc16b RK |
3554 | start_item = btrfs_item_nr(start); |
3555 | end_item = btrfs_item_nr(end); | |
41be1f3b JB |
3556 | data_len = btrfs_token_item_offset(l, start_item, &token) + |
3557 | btrfs_token_item_size(l, start_item, &token); | |
3558 | data_len = data_len - btrfs_token_item_offset(l, end_item, &token); | |
0783fcfc | 3559 | data_len += sizeof(struct btrfs_item) * nr; |
d4dbff95 | 3560 | WARN_ON(data_len < 0); |
be0e5c09 CM |
3561 | return data_len; |
3562 | } | |
3563 | ||
d4dbff95 CM |
3564 | /* |
3565 | * The space between the end of the leaf items and | |
3566 | * the start of the leaf data. IOW, how much room | |
3567 | * the leaf has left for both items and data | |
3568 | */ | |
d397712b | 3569 | noinline int btrfs_leaf_free_space(struct btrfs_root *root, |
e02119d5 | 3570 | struct extent_buffer *leaf) |
d4dbff95 | 3571 | { |
5f39d397 CM |
3572 | int nritems = btrfs_header_nritems(leaf); |
3573 | int ret; | |
3574 | ret = BTRFS_LEAF_DATA_SIZE(root) - leaf_space_used(leaf, 0, nritems); | |
3575 | if (ret < 0) { | |
efe120a0 FH |
3576 | btrfs_crit(root->fs_info, |
3577 | "leaf free space ret %d, leaf data size %lu, used %d nritems %d", | |
ae2f5411 | 3578 | ret, (unsigned long) BTRFS_LEAF_DATA_SIZE(root), |
5f39d397 CM |
3579 | leaf_space_used(leaf, 0, nritems), nritems); |
3580 | } | |
3581 | return ret; | |
d4dbff95 CM |
3582 | } |
3583 | ||
99d8f83c CM |
3584 | /* |
3585 | * min slot controls the lowest index we're willing to push to the | |
3586 | * right. We'll push up to and including min_slot, but no lower | |
3587 | */ | |
44871b1b CM |
3588 | static noinline int __push_leaf_right(struct btrfs_trans_handle *trans, |
3589 | struct btrfs_root *root, | |
3590 | struct btrfs_path *path, | |
3591 | int data_size, int empty, | |
3592 | struct extent_buffer *right, | |
99d8f83c CM |
3593 | int free_space, u32 left_nritems, |
3594 | u32 min_slot) | |
00ec4c51 | 3595 | { |
5f39d397 | 3596 | struct extent_buffer *left = path->nodes[0]; |
44871b1b | 3597 | struct extent_buffer *upper = path->nodes[1]; |
cfed81a0 | 3598 | struct btrfs_map_token token; |
5f39d397 | 3599 | struct btrfs_disk_key disk_key; |
00ec4c51 | 3600 | int slot; |
34a38218 | 3601 | u32 i; |
00ec4c51 CM |
3602 | int push_space = 0; |
3603 | int push_items = 0; | |
0783fcfc | 3604 | struct btrfs_item *item; |
34a38218 | 3605 | u32 nr; |
7518a238 | 3606 | u32 right_nritems; |
5f39d397 | 3607 | u32 data_end; |
db94535d | 3608 | u32 this_item_size; |
00ec4c51 | 3609 | |
cfed81a0 CM |
3610 | btrfs_init_map_token(&token); |
3611 | ||
34a38218 CM |
3612 | if (empty) |
3613 | nr = 0; | |
3614 | else | |
99d8f83c | 3615 | nr = max_t(u32, 1, min_slot); |
34a38218 | 3616 | |
31840ae1 | 3617 | if (path->slots[0] >= left_nritems) |
87b29b20 | 3618 | push_space += data_size; |
31840ae1 | 3619 | |
44871b1b | 3620 | slot = path->slots[1]; |
34a38218 CM |
3621 | i = left_nritems - 1; |
3622 | while (i >= nr) { | |
dd3cc16b | 3623 | item = btrfs_item_nr(i); |
db94535d | 3624 | |
31840ae1 ZY |
3625 | if (!empty && push_items > 0) { |
3626 | if (path->slots[0] > i) | |
3627 | break; | |
3628 | if (path->slots[0] == i) { | |
3629 | int space = btrfs_leaf_free_space(root, left); | |
3630 | if (space + push_space * 2 > free_space) | |
3631 | break; | |
3632 | } | |
3633 | } | |
3634 | ||
00ec4c51 | 3635 | if (path->slots[0] == i) |
87b29b20 | 3636 | push_space += data_size; |
db94535d | 3637 | |
db94535d CM |
3638 | this_item_size = btrfs_item_size(left, item); |
3639 | if (this_item_size + sizeof(*item) + push_space > free_space) | |
00ec4c51 | 3640 | break; |
31840ae1 | 3641 | |
00ec4c51 | 3642 | push_items++; |
db94535d | 3643 | push_space += this_item_size + sizeof(*item); |
34a38218 CM |
3644 | if (i == 0) |
3645 | break; | |
3646 | i--; | |
db94535d | 3647 | } |
5f39d397 | 3648 | |
925baedd CM |
3649 | if (push_items == 0) |
3650 | goto out_unlock; | |
5f39d397 | 3651 | |
6c1500f2 | 3652 | WARN_ON(!empty && push_items == left_nritems); |
5f39d397 | 3653 | |
00ec4c51 | 3654 | /* push left to right */ |
5f39d397 | 3655 | right_nritems = btrfs_header_nritems(right); |
34a38218 | 3656 | |
5f39d397 | 3657 | push_space = btrfs_item_end_nr(left, left_nritems - push_items); |
123abc88 | 3658 | push_space -= leaf_data_end(root, left); |
5f39d397 | 3659 | |
00ec4c51 | 3660 | /* make room in the right data area */ |
5f39d397 CM |
3661 | data_end = leaf_data_end(root, right); |
3662 | memmove_extent_buffer(right, | |
3663 | btrfs_leaf_data(right) + data_end - push_space, | |
3664 | btrfs_leaf_data(right) + data_end, | |
3665 | BTRFS_LEAF_DATA_SIZE(root) - data_end); | |
3666 | ||
00ec4c51 | 3667 | /* copy from the left data area */ |
5f39d397 | 3668 | copy_extent_buffer(right, left, btrfs_leaf_data(right) + |
d6025579 CM |
3669 | BTRFS_LEAF_DATA_SIZE(root) - push_space, |
3670 | btrfs_leaf_data(left) + leaf_data_end(root, left), | |
3671 | push_space); | |
5f39d397 CM |
3672 | |
3673 | memmove_extent_buffer(right, btrfs_item_nr_offset(push_items), | |
3674 | btrfs_item_nr_offset(0), | |
3675 | right_nritems * sizeof(struct btrfs_item)); | |
3676 | ||
00ec4c51 | 3677 | /* copy the items from left to right */ |
5f39d397 CM |
3678 | copy_extent_buffer(right, left, btrfs_item_nr_offset(0), |
3679 | btrfs_item_nr_offset(left_nritems - push_items), | |
3680 | push_items * sizeof(struct btrfs_item)); | |
00ec4c51 CM |
3681 | |
3682 | /* update the item pointers */ | |
7518a238 | 3683 | right_nritems += push_items; |
5f39d397 | 3684 | btrfs_set_header_nritems(right, right_nritems); |
123abc88 | 3685 | push_space = BTRFS_LEAF_DATA_SIZE(root); |
7518a238 | 3686 | for (i = 0; i < right_nritems; i++) { |
dd3cc16b | 3687 | item = btrfs_item_nr(i); |
cfed81a0 CM |
3688 | push_space -= btrfs_token_item_size(right, item, &token); |
3689 | btrfs_set_token_item_offset(right, item, push_space, &token); | |
db94535d CM |
3690 | } |
3691 | ||
7518a238 | 3692 | left_nritems -= push_items; |
5f39d397 | 3693 | btrfs_set_header_nritems(left, left_nritems); |
00ec4c51 | 3694 | |
34a38218 CM |
3695 | if (left_nritems) |
3696 | btrfs_mark_buffer_dirty(left); | |
f0486c68 | 3697 | else |
01d58472 | 3698 | clean_tree_block(trans, root->fs_info, left); |
f0486c68 | 3699 | |
5f39d397 | 3700 | btrfs_mark_buffer_dirty(right); |
a429e513 | 3701 | |
5f39d397 CM |
3702 | btrfs_item_key(right, &disk_key, 0); |
3703 | btrfs_set_node_key(upper, &disk_key, slot + 1); | |
d6025579 | 3704 | btrfs_mark_buffer_dirty(upper); |
02217ed2 | 3705 | |
00ec4c51 | 3706 | /* then fixup the leaf pointer in the path */ |
7518a238 CM |
3707 | if (path->slots[0] >= left_nritems) { |
3708 | path->slots[0] -= left_nritems; | |
925baedd | 3709 | if (btrfs_header_nritems(path->nodes[0]) == 0) |
01d58472 | 3710 | clean_tree_block(trans, root->fs_info, path->nodes[0]); |
925baedd | 3711 | btrfs_tree_unlock(path->nodes[0]); |
5f39d397 CM |
3712 | free_extent_buffer(path->nodes[0]); |
3713 | path->nodes[0] = right; | |
00ec4c51 CM |
3714 | path->slots[1] += 1; |
3715 | } else { | |
925baedd | 3716 | btrfs_tree_unlock(right); |
5f39d397 | 3717 | free_extent_buffer(right); |
00ec4c51 CM |
3718 | } |
3719 | return 0; | |
925baedd CM |
3720 | |
3721 | out_unlock: | |
3722 | btrfs_tree_unlock(right); | |
3723 | free_extent_buffer(right); | |
3724 | return 1; | |
00ec4c51 | 3725 | } |
925baedd | 3726 | |
44871b1b CM |
3727 | /* |
3728 | * push some data in the path leaf to the right, trying to free up at | |
3729 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
3730 | * | |
3731 | * returns 1 if the push failed because the other node didn't have enough | |
3732 | * room, 0 if everything worked out and < 0 if there were major errors. | |
99d8f83c CM |
3733 | * |
3734 | * this will push starting from min_slot to the end of the leaf. It won't | |
3735 | * push any slot lower than min_slot | |
44871b1b CM |
3736 | */ |
3737 | static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root | |
99d8f83c CM |
3738 | *root, struct btrfs_path *path, |
3739 | int min_data_size, int data_size, | |
3740 | int empty, u32 min_slot) | |
44871b1b CM |
3741 | { |
3742 | struct extent_buffer *left = path->nodes[0]; | |
3743 | struct extent_buffer *right; | |
3744 | struct extent_buffer *upper; | |
3745 | int slot; | |
3746 | int free_space; | |
3747 | u32 left_nritems; | |
3748 | int ret; | |
3749 | ||
3750 | if (!path->nodes[1]) | |
3751 | return 1; | |
3752 | ||
3753 | slot = path->slots[1]; | |
3754 | upper = path->nodes[1]; | |
3755 | if (slot >= btrfs_header_nritems(upper) - 1) | |
3756 | return 1; | |
3757 | ||
3758 | btrfs_assert_tree_locked(path->nodes[1]); | |
3759 | ||
3760 | right = read_node_slot(root, upper, slot + 1); | |
fb770ae4 LB |
3761 | /* |
3762 | * slot + 1 is not valid or we fail to read the right node, | |
3763 | * no big deal, just return. | |
3764 | */ | |
3765 | if (IS_ERR(right)) | |
91ca338d TI |
3766 | return 1; |
3767 | ||
44871b1b CM |
3768 | btrfs_tree_lock(right); |
3769 | btrfs_set_lock_blocking(right); | |
3770 | ||
3771 | free_space = btrfs_leaf_free_space(root, right); | |
3772 | if (free_space < data_size) | |
3773 | goto out_unlock; | |
3774 | ||
3775 | /* cow and double check */ | |
3776 | ret = btrfs_cow_block(trans, root, right, upper, | |
3777 | slot + 1, &right); | |
3778 | if (ret) | |
3779 | goto out_unlock; | |
3780 | ||
3781 | free_space = btrfs_leaf_free_space(root, right); | |
3782 | if (free_space < data_size) | |
3783 | goto out_unlock; | |
3784 | ||
3785 | left_nritems = btrfs_header_nritems(left); | |
3786 | if (left_nritems == 0) | |
3787 | goto out_unlock; | |
3788 | ||
2ef1fed2 FDBM |
3789 | if (path->slots[0] == left_nritems && !empty) { |
3790 | /* Key greater than all keys in the leaf, right neighbor has | |
3791 | * enough room for it and we're not emptying our leaf to delete | |
3792 | * it, therefore use right neighbor to insert the new item and | |
3793 | * no need to touch/dirty our left leaft. */ | |
3794 | btrfs_tree_unlock(left); | |
3795 | free_extent_buffer(left); | |
3796 | path->nodes[0] = right; | |
3797 | path->slots[0] = 0; | |
3798 | path->slots[1]++; | |
3799 | return 0; | |
3800 | } | |
3801 | ||
99d8f83c CM |
3802 | return __push_leaf_right(trans, root, path, min_data_size, empty, |
3803 | right, free_space, left_nritems, min_slot); | |
44871b1b CM |
3804 | out_unlock: |
3805 | btrfs_tree_unlock(right); | |
3806 | free_extent_buffer(right); | |
3807 | return 1; | |
3808 | } | |
3809 | ||
74123bd7 CM |
3810 | /* |
3811 | * push some data in the path leaf to the left, trying to free up at | |
3812 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
99d8f83c CM |
3813 | * |
3814 | * max_slot can put a limit on how far into the leaf we'll push items. The | |
3815 | * item at 'max_slot' won't be touched. Use (u32)-1 to make us do all the | |
3816 | * items | |
74123bd7 | 3817 | */ |
44871b1b CM |
3818 | static noinline int __push_leaf_left(struct btrfs_trans_handle *trans, |
3819 | struct btrfs_root *root, | |
3820 | struct btrfs_path *path, int data_size, | |
3821 | int empty, struct extent_buffer *left, | |
99d8f83c CM |
3822 | int free_space, u32 right_nritems, |
3823 | u32 max_slot) | |
be0e5c09 | 3824 | { |
5f39d397 CM |
3825 | struct btrfs_disk_key disk_key; |
3826 | struct extent_buffer *right = path->nodes[0]; | |
be0e5c09 | 3827 | int i; |
be0e5c09 CM |
3828 | int push_space = 0; |
3829 | int push_items = 0; | |
0783fcfc | 3830 | struct btrfs_item *item; |
7518a238 | 3831 | u32 old_left_nritems; |
34a38218 | 3832 | u32 nr; |
aa5d6bed | 3833 | int ret = 0; |
db94535d CM |
3834 | u32 this_item_size; |
3835 | u32 old_left_item_size; | |
cfed81a0 CM |
3836 | struct btrfs_map_token token; |
3837 | ||
3838 | btrfs_init_map_token(&token); | |
be0e5c09 | 3839 | |
34a38218 | 3840 | if (empty) |
99d8f83c | 3841 | nr = min(right_nritems, max_slot); |
34a38218 | 3842 | else |
99d8f83c | 3843 | nr = min(right_nritems - 1, max_slot); |
34a38218 CM |
3844 | |
3845 | for (i = 0; i < nr; i++) { | |
dd3cc16b | 3846 | item = btrfs_item_nr(i); |
db94535d | 3847 | |
31840ae1 ZY |
3848 | if (!empty && push_items > 0) { |
3849 | if (path->slots[0] < i) | |
3850 | break; | |
3851 | if (path->slots[0] == i) { | |
3852 | int space = btrfs_leaf_free_space(root, right); | |
3853 | if (space + push_space * 2 > free_space) | |
3854 | break; | |
3855 | } | |
3856 | } | |
3857 | ||
be0e5c09 | 3858 | if (path->slots[0] == i) |
87b29b20 | 3859 | push_space += data_size; |
db94535d CM |
3860 | |
3861 | this_item_size = btrfs_item_size(right, item); | |
3862 | if (this_item_size + sizeof(*item) + push_space > free_space) | |
be0e5c09 | 3863 | break; |
db94535d | 3864 | |
be0e5c09 | 3865 | push_items++; |
db94535d CM |
3866 | push_space += this_item_size + sizeof(*item); |
3867 | } | |
3868 | ||
be0e5c09 | 3869 | if (push_items == 0) { |
925baedd CM |
3870 | ret = 1; |
3871 | goto out; | |
be0e5c09 | 3872 | } |
fae7f21c | 3873 | WARN_ON(!empty && push_items == btrfs_header_nritems(right)); |
5f39d397 | 3874 | |
be0e5c09 | 3875 | /* push data from right to left */ |
5f39d397 CM |
3876 | copy_extent_buffer(left, right, |
3877 | btrfs_item_nr_offset(btrfs_header_nritems(left)), | |
3878 | btrfs_item_nr_offset(0), | |
3879 | push_items * sizeof(struct btrfs_item)); | |
3880 | ||
123abc88 | 3881 | push_space = BTRFS_LEAF_DATA_SIZE(root) - |
d397712b | 3882 | btrfs_item_offset_nr(right, push_items - 1); |
5f39d397 CM |
3883 | |
3884 | copy_extent_buffer(left, right, btrfs_leaf_data(left) + | |
d6025579 CM |
3885 | leaf_data_end(root, left) - push_space, |
3886 | btrfs_leaf_data(right) + | |
5f39d397 | 3887 | btrfs_item_offset_nr(right, push_items - 1), |
d6025579 | 3888 | push_space); |
5f39d397 | 3889 | old_left_nritems = btrfs_header_nritems(left); |
87b29b20 | 3890 | BUG_ON(old_left_nritems <= 0); |
eb60ceac | 3891 | |
db94535d | 3892 | old_left_item_size = btrfs_item_offset_nr(left, old_left_nritems - 1); |
0783fcfc | 3893 | for (i = old_left_nritems; i < old_left_nritems + push_items; i++) { |
5f39d397 | 3894 | u32 ioff; |
db94535d | 3895 | |
dd3cc16b | 3896 | item = btrfs_item_nr(i); |
db94535d | 3897 | |
cfed81a0 CM |
3898 | ioff = btrfs_token_item_offset(left, item, &token); |
3899 | btrfs_set_token_item_offset(left, item, | |
3900 | ioff - (BTRFS_LEAF_DATA_SIZE(root) - old_left_item_size), | |
3901 | &token); | |
be0e5c09 | 3902 | } |
5f39d397 | 3903 | btrfs_set_header_nritems(left, old_left_nritems + push_items); |
be0e5c09 CM |
3904 | |
3905 | /* fixup right node */ | |
31b1a2bd JL |
3906 | if (push_items > right_nritems) |
3907 | WARN(1, KERN_CRIT "push items %d nr %u\n", push_items, | |
d397712b | 3908 | right_nritems); |
34a38218 CM |
3909 | |
3910 | if (push_items < right_nritems) { | |
3911 | push_space = btrfs_item_offset_nr(right, push_items - 1) - | |
3912 | leaf_data_end(root, right); | |
3913 | memmove_extent_buffer(right, btrfs_leaf_data(right) + | |
3914 | BTRFS_LEAF_DATA_SIZE(root) - push_space, | |
3915 | btrfs_leaf_data(right) + | |
3916 | leaf_data_end(root, right), push_space); | |
3917 | ||
3918 | memmove_extent_buffer(right, btrfs_item_nr_offset(0), | |
5f39d397 CM |
3919 | btrfs_item_nr_offset(push_items), |
3920 | (btrfs_header_nritems(right) - push_items) * | |
3921 | sizeof(struct btrfs_item)); | |
34a38218 | 3922 | } |
eef1c494 Y |
3923 | right_nritems -= push_items; |
3924 | btrfs_set_header_nritems(right, right_nritems); | |
123abc88 | 3925 | push_space = BTRFS_LEAF_DATA_SIZE(root); |
5f39d397 | 3926 | for (i = 0; i < right_nritems; i++) { |
dd3cc16b | 3927 | item = btrfs_item_nr(i); |
db94535d | 3928 | |
cfed81a0 CM |
3929 | push_space = push_space - btrfs_token_item_size(right, |
3930 | item, &token); | |
3931 | btrfs_set_token_item_offset(right, item, push_space, &token); | |
db94535d | 3932 | } |
eb60ceac | 3933 | |
5f39d397 | 3934 | btrfs_mark_buffer_dirty(left); |
34a38218 CM |
3935 | if (right_nritems) |
3936 | btrfs_mark_buffer_dirty(right); | |
f0486c68 | 3937 | else |
01d58472 | 3938 | clean_tree_block(trans, root->fs_info, right); |
098f59c2 | 3939 | |
5f39d397 | 3940 | btrfs_item_key(right, &disk_key, 0); |
b7a0365e | 3941 | fixup_low_keys(root->fs_info, path, &disk_key, 1); |
be0e5c09 CM |
3942 | |
3943 | /* then fixup the leaf pointer in the path */ | |
3944 | if (path->slots[0] < push_items) { | |
3945 | path->slots[0] += old_left_nritems; | |
925baedd | 3946 | btrfs_tree_unlock(path->nodes[0]); |
5f39d397 CM |
3947 | free_extent_buffer(path->nodes[0]); |
3948 | path->nodes[0] = left; | |
be0e5c09 CM |
3949 | path->slots[1] -= 1; |
3950 | } else { | |
925baedd | 3951 | btrfs_tree_unlock(left); |
5f39d397 | 3952 | free_extent_buffer(left); |
be0e5c09 CM |
3953 | path->slots[0] -= push_items; |
3954 | } | |
eb60ceac | 3955 | BUG_ON(path->slots[0] < 0); |
aa5d6bed | 3956 | return ret; |
925baedd CM |
3957 | out: |
3958 | btrfs_tree_unlock(left); | |
3959 | free_extent_buffer(left); | |
3960 | return ret; | |
be0e5c09 CM |
3961 | } |
3962 | ||
44871b1b CM |
3963 | /* |
3964 | * push some data in the path leaf to the left, trying to free up at | |
3965 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
99d8f83c CM |
3966 | * |
3967 | * max_slot can put a limit on how far into the leaf we'll push items. The | |
3968 | * item at 'max_slot' won't be touched. Use (u32)-1 to make us push all the | |
3969 | * items | |
44871b1b CM |
3970 | */ |
3971 | static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root | |
99d8f83c CM |
3972 | *root, struct btrfs_path *path, int min_data_size, |
3973 | int data_size, int empty, u32 max_slot) | |
44871b1b CM |
3974 | { |
3975 | struct extent_buffer *right = path->nodes[0]; | |
3976 | struct extent_buffer *left; | |
3977 | int slot; | |
3978 | int free_space; | |
3979 | u32 right_nritems; | |
3980 | int ret = 0; | |
3981 | ||
3982 | slot = path->slots[1]; | |
3983 | if (slot == 0) | |
3984 | return 1; | |
3985 | if (!path->nodes[1]) | |
3986 | return 1; | |
3987 | ||
3988 | right_nritems = btrfs_header_nritems(right); | |
3989 | if (right_nritems == 0) | |
3990 | return 1; | |
3991 | ||
3992 | btrfs_assert_tree_locked(path->nodes[1]); | |
3993 | ||
3994 | left = read_node_slot(root, path->nodes[1], slot - 1); | |
fb770ae4 LB |
3995 | /* |
3996 | * slot - 1 is not valid or we fail to read the left node, | |
3997 | * no big deal, just return. | |
3998 | */ | |
3999 | if (IS_ERR(left)) | |
91ca338d TI |
4000 | return 1; |
4001 | ||
44871b1b CM |
4002 | btrfs_tree_lock(left); |
4003 | btrfs_set_lock_blocking(left); | |
4004 | ||
4005 | free_space = btrfs_leaf_free_space(root, left); | |
4006 | if (free_space < data_size) { | |
4007 | ret = 1; | |
4008 | goto out; | |
4009 | } | |
4010 | ||
4011 | /* cow and double check */ | |
4012 | ret = btrfs_cow_block(trans, root, left, | |
4013 | path->nodes[1], slot - 1, &left); | |
4014 | if (ret) { | |
4015 | /* we hit -ENOSPC, but it isn't fatal here */ | |
79787eaa JM |
4016 | if (ret == -ENOSPC) |
4017 | ret = 1; | |
44871b1b CM |
4018 | goto out; |
4019 | } | |
4020 | ||
4021 | free_space = btrfs_leaf_free_space(root, left); | |
4022 | if (free_space < data_size) { | |
4023 | ret = 1; | |
4024 | goto out; | |
4025 | } | |
4026 | ||
99d8f83c CM |
4027 | return __push_leaf_left(trans, root, path, min_data_size, |
4028 | empty, left, free_space, right_nritems, | |
4029 | max_slot); | |
44871b1b CM |
4030 | out: |
4031 | btrfs_tree_unlock(left); | |
4032 | free_extent_buffer(left); | |
4033 | return ret; | |
4034 | } | |
4035 | ||
4036 | /* | |
4037 | * split the path's leaf in two, making sure there is at least data_size | |
4038 | * available for the resulting leaf level of the path. | |
44871b1b | 4039 | */ |
143bede5 JM |
4040 | static noinline void copy_for_split(struct btrfs_trans_handle *trans, |
4041 | struct btrfs_root *root, | |
4042 | struct btrfs_path *path, | |
4043 | struct extent_buffer *l, | |
4044 | struct extent_buffer *right, | |
4045 | int slot, int mid, int nritems) | |
44871b1b CM |
4046 | { |
4047 | int data_copy_size; | |
4048 | int rt_data_off; | |
4049 | int i; | |
44871b1b | 4050 | struct btrfs_disk_key disk_key; |
cfed81a0 CM |
4051 | struct btrfs_map_token token; |
4052 | ||
4053 | btrfs_init_map_token(&token); | |
44871b1b CM |
4054 | |
4055 | nritems = nritems - mid; | |
4056 | btrfs_set_header_nritems(right, nritems); | |
4057 | data_copy_size = btrfs_item_end_nr(l, mid) - leaf_data_end(root, l); | |
4058 | ||
4059 | copy_extent_buffer(right, l, btrfs_item_nr_offset(0), | |
4060 | btrfs_item_nr_offset(mid), | |
4061 | nritems * sizeof(struct btrfs_item)); | |
4062 | ||
4063 | copy_extent_buffer(right, l, | |
4064 | btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) - | |
4065 | data_copy_size, btrfs_leaf_data(l) + | |
4066 | leaf_data_end(root, l), data_copy_size); | |
4067 | ||
4068 | rt_data_off = BTRFS_LEAF_DATA_SIZE(root) - | |
4069 | btrfs_item_end_nr(l, mid); | |
4070 | ||
4071 | for (i = 0; i < nritems; i++) { | |
dd3cc16b | 4072 | struct btrfs_item *item = btrfs_item_nr(i); |
44871b1b CM |
4073 | u32 ioff; |
4074 | ||
cfed81a0 CM |
4075 | ioff = btrfs_token_item_offset(right, item, &token); |
4076 | btrfs_set_token_item_offset(right, item, | |
4077 | ioff + rt_data_off, &token); | |
44871b1b CM |
4078 | } |
4079 | ||
44871b1b | 4080 | btrfs_set_header_nritems(l, mid); |
44871b1b | 4081 | btrfs_item_key(right, &disk_key, 0); |
143bede5 | 4082 | insert_ptr(trans, root, path, &disk_key, right->start, |
c3e06965 | 4083 | path->slots[1] + 1, 1); |
44871b1b CM |
4084 | |
4085 | btrfs_mark_buffer_dirty(right); | |
4086 | btrfs_mark_buffer_dirty(l); | |
4087 | BUG_ON(path->slots[0] != slot); | |
4088 | ||
44871b1b CM |
4089 | if (mid <= slot) { |
4090 | btrfs_tree_unlock(path->nodes[0]); | |
4091 | free_extent_buffer(path->nodes[0]); | |
4092 | path->nodes[0] = right; | |
4093 | path->slots[0] -= mid; | |
4094 | path->slots[1] += 1; | |
4095 | } else { | |
4096 | btrfs_tree_unlock(right); | |
4097 | free_extent_buffer(right); | |
4098 | } | |
4099 | ||
4100 | BUG_ON(path->slots[0] < 0); | |
44871b1b CM |
4101 | } |
4102 | ||
99d8f83c CM |
4103 | /* |
4104 | * double splits happen when we need to insert a big item in the middle | |
4105 | * of a leaf. A double split can leave us with 3 mostly empty leaves: | |
4106 | * leaf: [ slots 0 - N] [ our target ] [ N + 1 - total in leaf ] | |
4107 | * A B C | |
4108 | * | |
4109 | * We avoid this by trying to push the items on either side of our target | |
4110 | * into the adjacent leaves. If all goes well we can avoid the double split | |
4111 | * completely. | |
4112 | */ | |
4113 | static noinline int push_for_double_split(struct btrfs_trans_handle *trans, | |
4114 | struct btrfs_root *root, | |
4115 | struct btrfs_path *path, | |
4116 | int data_size) | |
4117 | { | |
4118 | int ret; | |
4119 | int progress = 0; | |
4120 | int slot; | |
4121 | u32 nritems; | |
5a4267ca | 4122 | int space_needed = data_size; |
99d8f83c CM |
4123 | |
4124 | slot = path->slots[0]; | |
5a4267ca FDBM |
4125 | if (slot < btrfs_header_nritems(path->nodes[0])) |
4126 | space_needed -= btrfs_leaf_free_space(root, path->nodes[0]); | |
99d8f83c CM |
4127 | |
4128 | /* | |
4129 | * try to push all the items after our slot into the | |
4130 | * right leaf | |
4131 | */ | |
5a4267ca | 4132 | ret = push_leaf_right(trans, root, path, 1, space_needed, 0, slot); |
99d8f83c CM |
4133 | if (ret < 0) |
4134 | return ret; | |
4135 | ||
4136 | if (ret == 0) | |
4137 | progress++; | |
4138 | ||
4139 | nritems = btrfs_header_nritems(path->nodes[0]); | |
4140 | /* | |
4141 | * our goal is to get our slot at the start or end of a leaf. If | |
4142 | * we've done so we're done | |
4143 | */ | |
4144 | if (path->slots[0] == 0 || path->slots[0] == nritems) | |
4145 | return 0; | |
4146 | ||
4147 | if (btrfs_leaf_free_space(root, path->nodes[0]) >= data_size) | |
4148 | return 0; | |
4149 | ||
4150 | /* try to push all the items before our slot into the next leaf */ | |
4151 | slot = path->slots[0]; | |
5a4267ca | 4152 | ret = push_leaf_left(trans, root, path, 1, space_needed, 0, slot); |
99d8f83c CM |
4153 | if (ret < 0) |
4154 | return ret; | |
4155 | ||
4156 | if (ret == 0) | |
4157 | progress++; | |
4158 | ||
4159 | if (progress) | |
4160 | return 0; | |
4161 | return 1; | |
4162 | } | |
4163 | ||
74123bd7 CM |
4164 | /* |
4165 | * split the path's leaf in two, making sure there is at least data_size | |
4166 | * available for the resulting leaf level of the path. | |
aa5d6bed CM |
4167 | * |
4168 | * returns 0 if all went well and < 0 on failure. | |
74123bd7 | 4169 | */ |
e02119d5 CM |
4170 | static noinline int split_leaf(struct btrfs_trans_handle *trans, |
4171 | struct btrfs_root *root, | |
4172 | struct btrfs_key *ins_key, | |
4173 | struct btrfs_path *path, int data_size, | |
4174 | int extend) | |
be0e5c09 | 4175 | { |
5d4f98a2 | 4176 | struct btrfs_disk_key disk_key; |
5f39d397 | 4177 | struct extent_buffer *l; |
7518a238 | 4178 | u32 nritems; |
eb60ceac CM |
4179 | int mid; |
4180 | int slot; | |
5f39d397 | 4181 | struct extent_buffer *right; |
b7a0365e | 4182 | struct btrfs_fs_info *fs_info = root->fs_info; |
d4dbff95 | 4183 | int ret = 0; |
aa5d6bed | 4184 | int wret; |
5d4f98a2 | 4185 | int split; |
cc0c5538 | 4186 | int num_doubles = 0; |
99d8f83c | 4187 | int tried_avoid_double = 0; |
aa5d6bed | 4188 | |
a5719521 YZ |
4189 | l = path->nodes[0]; |
4190 | slot = path->slots[0]; | |
4191 | if (extend && data_size + btrfs_item_size_nr(l, slot) + | |
4192 | sizeof(struct btrfs_item) > BTRFS_LEAF_DATA_SIZE(root)) | |
4193 | return -EOVERFLOW; | |
4194 | ||
40689478 | 4195 | /* first try to make some room by pushing left and right */ |
33157e05 | 4196 | if (data_size && path->nodes[1]) { |
5a4267ca FDBM |
4197 | int space_needed = data_size; |
4198 | ||
4199 | if (slot < btrfs_header_nritems(l)) | |
4200 | space_needed -= btrfs_leaf_free_space(root, l); | |
4201 | ||
4202 | wret = push_leaf_right(trans, root, path, space_needed, | |
4203 | space_needed, 0, 0); | |
d397712b | 4204 | if (wret < 0) |
eaee50e8 | 4205 | return wret; |
3685f791 | 4206 | if (wret) { |
5a4267ca FDBM |
4207 | wret = push_leaf_left(trans, root, path, space_needed, |
4208 | space_needed, 0, (u32)-1); | |
3685f791 CM |
4209 | if (wret < 0) |
4210 | return wret; | |
4211 | } | |
4212 | l = path->nodes[0]; | |
aa5d6bed | 4213 | |
3685f791 | 4214 | /* did the pushes work? */ |
87b29b20 | 4215 | if (btrfs_leaf_free_space(root, l) >= data_size) |
3685f791 | 4216 | return 0; |
3326d1b0 | 4217 | } |
aa5d6bed | 4218 | |
5c680ed6 | 4219 | if (!path->nodes[1]) { |
fdd99c72 | 4220 | ret = insert_new_root(trans, root, path, 1); |
5c680ed6 CM |
4221 | if (ret) |
4222 | return ret; | |
4223 | } | |
cc0c5538 | 4224 | again: |
5d4f98a2 | 4225 | split = 1; |
cc0c5538 | 4226 | l = path->nodes[0]; |
eb60ceac | 4227 | slot = path->slots[0]; |
5f39d397 | 4228 | nritems = btrfs_header_nritems(l); |
d397712b | 4229 | mid = (nritems + 1) / 2; |
54aa1f4d | 4230 | |
5d4f98a2 YZ |
4231 | if (mid <= slot) { |
4232 | if (nritems == 1 || | |
4233 | leaf_space_used(l, mid, nritems - mid) + data_size > | |
4234 | BTRFS_LEAF_DATA_SIZE(root)) { | |
4235 | if (slot >= nritems) { | |
4236 | split = 0; | |
4237 | } else { | |
4238 | mid = slot; | |
4239 | if (mid != nritems && | |
4240 | leaf_space_used(l, mid, nritems - mid) + | |
4241 | data_size > BTRFS_LEAF_DATA_SIZE(root)) { | |
99d8f83c CM |
4242 | if (data_size && !tried_avoid_double) |
4243 | goto push_for_double; | |
5d4f98a2 YZ |
4244 | split = 2; |
4245 | } | |
4246 | } | |
4247 | } | |
4248 | } else { | |
4249 | if (leaf_space_used(l, 0, mid) + data_size > | |
4250 | BTRFS_LEAF_DATA_SIZE(root)) { | |
4251 | if (!extend && data_size && slot == 0) { | |
4252 | split = 0; | |
4253 | } else if ((extend || !data_size) && slot == 0) { | |
4254 | mid = 1; | |
4255 | } else { | |
4256 | mid = slot; | |
4257 | if (mid != nritems && | |
4258 | leaf_space_used(l, mid, nritems - mid) + | |
4259 | data_size > BTRFS_LEAF_DATA_SIZE(root)) { | |
99d8f83c CM |
4260 | if (data_size && !tried_avoid_double) |
4261 | goto push_for_double; | |
67871254 | 4262 | split = 2; |
5d4f98a2 YZ |
4263 | } |
4264 | } | |
4265 | } | |
4266 | } | |
4267 | ||
4268 | if (split == 0) | |
4269 | btrfs_cpu_key_to_disk(&disk_key, ins_key); | |
4270 | else | |
4271 | btrfs_item_key(l, &disk_key, mid); | |
4272 | ||
4d75f8a9 DS |
4273 | right = btrfs_alloc_tree_block(trans, root, 0, root->root_key.objectid, |
4274 | &disk_key, 0, l->start, 0); | |
f0486c68 | 4275 | if (IS_ERR(right)) |
5f39d397 | 4276 | return PTR_ERR(right); |
f0486c68 | 4277 | |
707e8a07 | 4278 | root_add_used(root, root->nodesize); |
5f39d397 CM |
4279 | |
4280 | memset_extent_buffer(right, 0, 0, sizeof(struct btrfs_header)); | |
db94535d | 4281 | btrfs_set_header_bytenr(right, right->start); |
5f39d397 | 4282 | btrfs_set_header_generation(right, trans->transid); |
5d4f98a2 | 4283 | btrfs_set_header_backref_rev(right, BTRFS_MIXED_BACKREF_REV); |
5f39d397 CM |
4284 | btrfs_set_header_owner(right, root->root_key.objectid); |
4285 | btrfs_set_header_level(right, 0); | |
b7a0365e | 4286 | write_extent_buffer(right, fs_info->fsid, |
0a4e5586 | 4287 | btrfs_header_fsid(), BTRFS_FSID_SIZE); |
e17cade2 | 4288 | |
b7a0365e | 4289 | write_extent_buffer(right, fs_info->chunk_tree_uuid, |
b308bc2f | 4290 | btrfs_header_chunk_tree_uuid(right), |
e17cade2 | 4291 | BTRFS_UUID_SIZE); |
44871b1b | 4292 | |
5d4f98a2 YZ |
4293 | if (split == 0) { |
4294 | if (mid <= slot) { | |
4295 | btrfs_set_header_nritems(right, 0); | |
143bede5 | 4296 | insert_ptr(trans, root, path, &disk_key, right->start, |
c3e06965 | 4297 | path->slots[1] + 1, 1); |
5d4f98a2 YZ |
4298 | btrfs_tree_unlock(path->nodes[0]); |
4299 | free_extent_buffer(path->nodes[0]); | |
4300 | path->nodes[0] = right; | |
4301 | path->slots[0] = 0; | |
4302 | path->slots[1] += 1; | |
4303 | } else { | |
4304 | btrfs_set_header_nritems(right, 0); | |
143bede5 | 4305 | insert_ptr(trans, root, path, &disk_key, right->start, |
c3e06965 | 4306 | path->slots[1], 1); |
5d4f98a2 YZ |
4307 | btrfs_tree_unlock(path->nodes[0]); |
4308 | free_extent_buffer(path->nodes[0]); | |
4309 | path->nodes[0] = right; | |
4310 | path->slots[0] = 0; | |
143bede5 | 4311 | if (path->slots[1] == 0) |
b7a0365e | 4312 | fixup_low_keys(fs_info, path, &disk_key, 1); |
d4dbff95 | 4313 | } |
196e0249 LB |
4314 | /* |
4315 | * We create a new leaf 'right' for the required ins_len and | |
4316 | * we'll do btrfs_mark_buffer_dirty() on this leaf after copying | |
4317 | * the content of ins_len to 'right'. | |
4318 | */ | |
5d4f98a2 | 4319 | return ret; |
d4dbff95 | 4320 | } |
74123bd7 | 4321 | |
143bede5 | 4322 | copy_for_split(trans, root, path, l, right, slot, mid, nritems); |
31840ae1 | 4323 | |
5d4f98a2 | 4324 | if (split == 2) { |
cc0c5538 CM |
4325 | BUG_ON(num_doubles != 0); |
4326 | num_doubles++; | |
4327 | goto again; | |
a429e513 | 4328 | } |
44871b1b | 4329 | |
143bede5 | 4330 | return 0; |
99d8f83c CM |
4331 | |
4332 | push_for_double: | |
4333 | push_for_double_split(trans, root, path, data_size); | |
4334 | tried_avoid_double = 1; | |
4335 | if (btrfs_leaf_free_space(root, path->nodes[0]) >= data_size) | |
4336 | return 0; | |
4337 | goto again; | |
be0e5c09 CM |
4338 | } |
4339 | ||
ad48fd75 YZ |
4340 | static noinline int setup_leaf_for_split(struct btrfs_trans_handle *trans, |
4341 | struct btrfs_root *root, | |
4342 | struct btrfs_path *path, int ins_len) | |
459931ec | 4343 | { |
ad48fd75 | 4344 | struct btrfs_key key; |
459931ec | 4345 | struct extent_buffer *leaf; |
ad48fd75 YZ |
4346 | struct btrfs_file_extent_item *fi; |
4347 | u64 extent_len = 0; | |
4348 | u32 item_size; | |
4349 | int ret; | |
459931ec CM |
4350 | |
4351 | leaf = path->nodes[0]; | |
ad48fd75 YZ |
4352 | btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
4353 | ||
4354 | BUG_ON(key.type != BTRFS_EXTENT_DATA_KEY && | |
4355 | key.type != BTRFS_EXTENT_CSUM_KEY); | |
4356 | ||
4357 | if (btrfs_leaf_free_space(root, leaf) >= ins_len) | |
4358 | return 0; | |
459931ec CM |
4359 | |
4360 | item_size = btrfs_item_size_nr(leaf, path->slots[0]); | |
ad48fd75 YZ |
4361 | if (key.type == BTRFS_EXTENT_DATA_KEY) { |
4362 | fi = btrfs_item_ptr(leaf, path->slots[0], | |
4363 | struct btrfs_file_extent_item); | |
4364 | extent_len = btrfs_file_extent_num_bytes(leaf, fi); | |
4365 | } | |
b3b4aa74 | 4366 | btrfs_release_path(path); |
459931ec | 4367 | |
459931ec | 4368 | path->keep_locks = 1; |
ad48fd75 YZ |
4369 | path->search_for_split = 1; |
4370 | ret = btrfs_search_slot(trans, root, &key, path, 0, 1); | |
459931ec | 4371 | path->search_for_split = 0; |
a8df6fe6 FM |
4372 | if (ret > 0) |
4373 | ret = -EAGAIN; | |
ad48fd75 YZ |
4374 | if (ret < 0) |
4375 | goto err; | |
459931ec | 4376 | |
ad48fd75 YZ |
4377 | ret = -EAGAIN; |
4378 | leaf = path->nodes[0]; | |
a8df6fe6 FM |
4379 | /* if our item isn't there, return now */ |
4380 | if (item_size != btrfs_item_size_nr(leaf, path->slots[0])) | |
ad48fd75 YZ |
4381 | goto err; |
4382 | ||
109f6aef CM |
4383 | /* the leaf has changed, it now has room. return now */ |
4384 | if (btrfs_leaf_free_space(root, path->nodes[0]) >= ins_len) | |
4385 | goto err; | |
4386 | ||
ad48fd75 YZ |
4387 | if (key.type == BTRFS_EXTENT_DATA_KEY) { |
4388 | fi = btrfs_item_ptr(leaf, path->slots[0], | |
4389 | struct btrfs_file_extent_item); | |
4390 | if (extent_len != btrfs_file_extent_num_bytes(leaf, fi)) | |
4391 | goto err; | |
459931ec CM |
4392 | } |
4393 | ||
b9473439 | 4394 | btrfs_set_path_blocking(path); |
ad48fd75 | 4395 | ret = split_leaf(trans, root, &key, path, ins_len, 1); |
f0486c68 YZ |
4396 | if (ret) |
4397 | goto err; | |
459931ec | 4398 | |
ad48fd75 | 4399 | path->keep_locks = 0; |
b9473439 | 4400 | btrfs_unlock_up_safe(path, 1); |
ad48fd75 YZ |
4401 | return 0; |
4402 | err: | |
4403 | path->keep_locks = 0; | |
4404 | return ret; | |
4405 | } | |
4406 | ||
4407 | static noinline int split_item(struct btrfs_trans_handle *trans, | |
4408 | struct btrfs_root *root, | |
4409 | struct btrfs_path *path, | |
4410 | struct btrfs_key *new_key, | |
4411 | unsigned long split_offset) | |
4412 | { | |
4413 | struct extent_buffer *leaf; | |
4414 | struct btrfs_item *item; | |
4415 | struct btrfs_item *new_item; | |
4416 | int slot; | |
4417 | char *buf; | |
4418 | u32 nritems; | |
4419 | u32 item_size; | |
4420 | u32 orig_offset; | |
4421 | struct btrfs_disk_key disk_key; | |
4422 | ||
b9473439 CM |
4423 | leaf = path->nodes[0]; |
4424 | BUG_ON(btrfs_leaf_free_space(root, leaf) < sizeof(struct btrfs_item)); | |
4425 | ||
b4ce94de CM |
4426 | btrfs_set_path_blocking(path); |
4427 | ||
dd3cc16b | 4428 | item = btrfs_item_nr(path->slots[0]); |
459931ec CM |
4429 | orig_offset = btrfs_item_offset(leaf, item); |
4430 | item_size = btrfs_item_size(leaf, item); | |
4431 | ||
459931ec | 4432 | buf = kmalloc(item_size, GFP_NOFS); |
ad48fd75 YZ |
4433 | if (!buf) |
4434 | return -ENOMEM; | |
4435 | ||
459931ec CM |
4436 | read_extent_buffer(leaf, buf, btrfs_item_ptr_offset(leaf, |
4437 | path->slots[0]), item_size); | |
459931ec | 4438 | |
ad48fd75 | 4439 | slot = path->slots[0] + 1; |
459931ec | 4440 | nritems = btrfs_header_nritems(leaf); |
459931ec CM |
4441 | if (slot != nritems) { |
4442 | /* shift the items */ | |
4443 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + 1), | |
ad48fd75 YZ |
4444 | btrfs_item_nr_offset(slot), |
4445 | (nritems - slot) * sizeof(struct btrfs_item)); | |
459931ec CM |
4446 | } |
4447 | ||
4448 | btrfs_cpu_key_to_disk(&disk_key, new_key); | |
4449 | btrfs_set_item_key(leaf, &disk_key, slot); | |
4450 | ||
dd3cc16b | 4451 | new_item = btrfs_item_nr(slot); |
459931ec CM |
4452 | |
4453 | btrfs_set_item_offset(leaf, new_item, orig_offset); | |
4454 | btrfs_set_item_size(leaf, new_item, item_size - split_offset); | |
4455 | ||
4456 | btrfs_set_item_offset(leaf, item, | |
4457 | orig_offset + item_size - split_offset); | |
4458 | btrfs_set_item_size(leaf, item, split_offset); | |
4459 | ||
4460 | btrfs_set_header_nritems(leaf, nritems + 1); | |
4461 | ||
4462 | /* write the data for the start of the original item */ | |
4463 | write_extent_buffer(leaf, buf, | |
4464 | btrfs_item_ptr_offset(leaf, path->slots[0]), | |
4465 | split_offset); | |
4466 | ||
4467 | /* write the data for the new item */ | |
4468 | write_extent_buffer(leaf, buf + split_offset, | |
4469 | btrfs_item_ptr_offset(leaf, slot), | |
4470 | item_size - split_offset); | |
4471 | btrfs_mark_buffer_dirty(leaf); | |
4472 | ||
ad48fd75 | 4473 | BUG_ON(btrfs_leaf_free_space(root, leaf) < 0); |
459931ec | 4474 | kfree(buf); |
ad48fd75 YZ |
4475 | return 0; |
4476 | } | |
4477 | ||
4478 | /* | |
4479 | * This function splits a single item into two items, | |
4480 | * giving 'new_key' to the new item and splitting the | |
4481 | * old one at split_offset (from the start of the item). | |
4482 | * | |
4483 | * The path may be released by this operation. After | |
4484 | * the split, the path is pointing to the old item. The | |
4485 | * new item is going to be in the same node as the old one. | |
4486 | * | |
4487 | * Note, the item being split must be smaller enough to live alone on | |
4488 | * a tree block with room for one extra struct btrfs_item | |
4489 | * | |
4490 | * This allows us to split the item in place, keeping a lock on the | |
4491 | * leaf the entire time. | |
4492 | */ | |
4493 | int btrfs_split_item(struct btrfs_trans_handle *trans, | |
4494 | struct btrfs_root *root, | |
4495 | struct btrfs_path *path, | |
4496 | struct btrfs_key *new_key, | |
4497 | unsigned long split_offset) | |
4498 | { | |
4499 | int ret; | |
4500 | ret = setup_leaf_for_split(trans, root, path, | |
4501 | sizeof(struct btrfs_item)); | |
4502 | if (ret) | |
4503 | return ret; | |
4504 | ||
4505 | ret = split_item(trans, root, path, new_key, split_offset); | |
459931ec CM |
4506 | return ret; |
4507 | } | |
4508 | ||
ad48fd75 YZ |
4509 | /* |
4510 | * This function duplicate a item, giving 'new_key' to the new item. | |
4511 | * It guarantees both items live in the same tree leaf and the new item | |
4512 | * is contiguous with the original item. | |
4513 | * | |
4514 | * This allows us to split file extent in place, keeping a lock on the | |
4515 | * leaf the entire time. | |
4516 | */ | |
4517 | int btrfs_duplicate_item(struct btrfs_trans_handle *trans, | |
4518 | struct btrfs_root *root, | |
4519 | struct btrfs_path *path, | |
4520 | struct btrfs_key *new_key) | |
4521 | { | |
4522 | struct extent_buffer *leaf; | |
4523 | int ret; | |
4524 | u32 item_size; | |
4525 | ||
4526 | leaf = path->nodes[0]; | |
4527 | item_size = btrfs_item_size_nr(leaf, path->slots[0]); | |
4528 | ret = setup_leaf_for_split(trans, root, path, | |
4529 | item_size + sizeof(struct btrfs_item)); | |
4530 | if (ret) | |
4531 | return ret; | |
4532 | ||
4533 | path->slots[0]++; | |
afe5fea7 | 4534 | setup_items_for_insert(root, path, new_key, &item_size, |
143bede5 JM |
4535 | item_size, item_size + |
4536 | sizeof(struct btrfs_item), 1); | |
ad48fd75 YZ |
4537 | leaf = path->nodes[0]; |
4538 | memcpy_extent_buffer(leaf, | |
4539 | btrfs_item_ptr_offset(leaf, path->slots[0]), | |
4540 | btrfs_item_ptr_offset(leaf, path->slots[0] - 1), | |
4541 | item_size); | |
4542 | return 0; | |
4543 | } | |
4544 | ||
d352ac68 CM |
4545 | /* |
4546 | * make the item pointed to by the path smaller. new_size indicates | |
4547 | * how small to make it, and from_end tells us if we just chop bytes | |
4548 | * off the end of the item or if we shift the item to chop bytes off | |
4549 | * the front. | |
4550 | */ | |
afe5fea7 | 4551 | void btrfs_truncate_item(struct btrfs_root *root, struct btrfs_path *path, |
143bede5 | 4552 | u32 new_size, int from_end) |
b18c6685 | 4553 | { |
b18c6685 | 4554 | int slot; |
5f39d397 CM |
4555 | struct extent_buffer *leaf; |
4556 | struct btrfs_item *item; | |
b18c6685 CM |
4557 | u32 nritems; |
4558 | unsigned int data_end; | |
4559 | unsigned int old_data_start; | |
4560 | unsigned int old_size; | |
4561 | unsigned int size_diff; | |
4562 | int i; | |
cfed81a0 CM |
4563 | struct btrfs_map_token token; |
4564 | ||
4565 | btrfs_init_map_token(&token); | |
b18c6685 | 4566 | |
5f39d397 | 4567 | leaf = path->nodes[0]; |
179e29e4 CM |
4568 | slot = path->slots[0]; |
4569 | ||
4570 | old_size = btrfs_item_size_nr(leaf, slot); | |
4571 | if (old_size == new_size) | |
143bede5 | 4572 | return; |
b18c6685 | 4573 | |
5f39d397 | 4574 | nritems = btrfs_header_nritems(leaf); |
b18c6685 CM |
4575 | data_end = leaf_data_end(root, leaf); |
4576 | ||
5f39d397 | 4577 | old_data_start = btrfs_item_offset_nr(leaf, slot); |
179e29e4 | 4578 | |
b18c6685 CM |
4579 | size_diff = old_size - new_size; |
4580 | ||
4581 | BUG_ON(slot < 0); | |
4582 | BUG_ON(slot >= nritems); | |
4583 | ||
4584 | /* | |
4585 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
4586 | */ | |
4587 | /* first correct the data pointers */ | |
4588 | for (i = slot; i < nritems; i++) { | |
5f39d397 | 4589 | u32 ioff; |
dd3cc16b | 4590 | item = btrfs_item_nr(i); |
db94535d | 4591 | |
cfed81a0 CM |
4592 | ioff = btrfs_token_item_offset(leaf, item, &token); |
4593 | btrfs_set_token_item_offset(leaf, item, | |
4594 | ioff + size_diff, &token); | |
b18c6685 | 4595 | } |
db94535d | 4596 | |
b18c6685 | 4597 | /* shift the data */ |
179e29e4 CM |
4598 | if (from_end) { |
4599 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + | |
4600 | data_end + size_diff, btrfs_leaf_data(leaf) + | |
4601 | data_end, old_data_start + new_size - data_end); | |
4602 | } else { | |
4603 | struct btrfs_disk_key disk_key; | |
4604 | u64 offset; | |
4605 | ||
4606 | btrfs_item_key(leaf, &disk_key, slot); | |
4607 | ||
4608 | if (btrfs_disk_key_type(&disk_key) == BTRFS_EXTENT_DATA_KEY) { | |
4609 | unsigned long ptr; | |
4610 | struct btrfs_file_extent_item *fi; | |
4611 | ||
4612 | fi = btrfs_item_ptr(leaf, slot, | |
4613 | struct btrfs_file_extent_item); | |
4614 | fi = (struct btrfs_file_extent_item *)( | |
4615 | (unsigned long)fi - size_diff); | |
4616 | ||
4617 | if (btrfs_file_extent_type(leaf, fi) == | |
4618 | BTRFS_FILE_EXTENT_INLINE) { | |
4619 | ptr = btrfs_item_ptr_offset(leaf, slot); | |
4620 | memmove_extent_buffer(leaf, ptr, | |
d397712b | 4621 | (unsigned long)fi, |
7ec20afb | 4622 | BTRFS_FILE_EXTENT_INLINE_DATA_START); |
179e29e4 CM |
4623 | } |
4624 | } | |
4625 | ||
4626 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + | |
4627 | data_end + size_diff, btrfs_leaf_data(leaf) + | |
4628 | data_end, old_data_start - data_end); | |
4629 | ||
4630 | offset = btrfs_disk_key_offset(&disk_key); | |
4631 | btrfs_set_disk_key_offset(&disk_key, offset + size_diff); | |
4632 | btrfs_set_item_key(leaf, &disk_key, slot); | |
4633 | if (slot == 0) | |
b7a0365e | 4634 | fixup_low_keys(root->fs_info, path, &disk_key, 1); |
179e29e4 | 4635 | } |
5f39d397 | 4636 | |
dd3cc16b | 4637 | item = btrfs_item_nr(slot); |
5f39d397 CM |
4638 | btrfs_set_item_size(leaf, item, new_size); |
4639 | btrfs_mark_buffer_dirty(leaf); | |
b18c6685 | 4640 | |
5f39d397 CM |
4641 | if (btrfs_leaf_free_space(root, leaf) < 0) { |
4642 | btrfs_print_leaf(root, leaf); | |
b18c6685 | 4643 | BUG(); |
5f39d397 | 4644 | } |
b18c6685 CM |
4645 | } |
4646 | ||
d352ac68 | 4647 | /* |
8f69dbd2 | 4648 | * make the item pointed to by the path bigger, data_size is the added size. |
d352ac68 | 4649 | */ |
4b90c680 | 4650 | void btrfs_extend_item(struct btrfs_root *root, struct btrfs_path *path, |
143bede5 | 4651 | u32 data_size) |
6567e837 | 4652 | { |
6567e837 | 4653 | int slot; |
5f39d397 CM |
4654 | struct extent_buffer *leaf; |
4655 | struct btrfs_item *item; | |
6567e837 CM |
4656 | u32 nritems; |
4657 | unsigned int data_end; | |
4658 | unsigned int old_data; | |
4659 | unsigned int old_size; | |
4660 | int i; | |
cfed81a0 CM |
4661 | struct btrfs_map_token token; |
4662 | ||
4663 | btrfs_init_map_token(&token); | |
6567e837 | 4664 | |
5f39d397 | 4665 | leaf = path->nodes[0]; |
6567e837 | 4666 | |
5f39d397 | 4667 | nritems = btrfs_header_nritems(leaf); |
6567e837 CM |
4668 | data_end = leaf_data_end(root, leaf); |
4669 | ||
5f39d397 CM |
4670 | if (btrfs_leaf_free_space(root, leaf) < data_size) { |
4671 | btrfs_print_leaf(root, leaf); | |
6567e837 | 4672 | BUG(); |
5f39d397 | 4673 | } |
6567e837 | 4674 | slot = path->slots[0]; |
5f39d397 | 4675 | old_data = btrfs_item_end_nr(leaf, slot); |
6567e837 CM |
4676 | |
4677 | BUG_ON(slot < 0); | |
3326d1b0 CM |
4678 | if (slot >= nritems) { |
4679 | btrfs_print_leaf(root, leaf); | |
efe120a0 | 4680 | btrfs_crit(root->fs_info, "slot %d too large, nritems %d", |
d397712b | 4681 | slot, nritems); |
3326d1b0 CM |
4682 | BUG_ON(1); |
4683 | } | |
6567e837 CM |
4684 | |
4685 | /* | |
4686 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
4687 | */ | |
4688 | /* first correct the data pointers */ | |
4689 | for (i = slot; i < nritems; i++) { | |
5f39d397 | 4690 | u32 ioff; |
dd3cc16b | 4691 | item = btrfs_item_nr(i); |
db94535d | 4692 | |
cfed81a0 CM |
4693 | ioff = btrfs_token_item_offset(leaf, item, &token); |
4694 | btrfs_set_token_item_offset(leaf, item, | |
4695 | ioff - data_size, &token); | |
6567e837 | 4696 | } |
5f39d397 | 4697 | |
6567e837 | 4698 | /* shift the data */ |
5f39d397 | 4699 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + |
6567e837 CM |
4700 | data_end - data_size, btrfs_leaf_data(leaf) + |
4701 | data_end, old_data - data_end); | |
5f39d397 | 4702 | |
6567e837 | 4703 | data_end = old_data; |
5f39d397 | 4704 | old_size = btrfs_item_size_nr(leaf, slot); |
dd3cc16b | 4705 | item = btrfs_item_nr(slot); |
5f39d397 CM |
4706 | btrfs_set_item_size(leaf, item, old_size + data_size); |
4707 | btrfs_mark_buffer_dirty(leaf); | |
6567e837 | 4708 | |
5f39d397 CM |
4709 | if (btrfs_leaf_free_space(root, leaf) < 0) { |
4710 | btrfs_print_leaf(root, leaf); | |
6567e837 | 4711 | BUG(); |
5f39d397 | 4712 | } |
6567e837 CM |
4713 | } |
4714 | ||
74123bd7 | 4715 | /* |
44871b1b CM |
4716 | * this is a helper for btrfs_insert_empty_items, the main goal here is |
4717 | * to save stack depth by doing the bulk of the work in a function | |
4718 | * that doesn't call btrfs_search_slot | |
74123bd7 | 4719 | */ |
afe5fea7 | 4720 | void setup_items_for_insert(struct btrfs_root *root, struct btrfs_path *path, |
143bede5 JM |
4721 | struct btrfs_key *cpu_key, u32 *data_size, |
4722 | u32 total_data, u32 total_size, int nr) | |
be0e5c09 | 4723 | { |
5f39d397 | 4724 | struct btrfs_item *item; |
9c58309d | 4725 | int i; |
7518a238 | 4726 | u32 nritems; |
be0e5c09 | 4727 | unsigned int data_end; |
e2fa7227 | 4728 | struct btrfs_disk_key disk_key; |
44871b1b CM |
4729 | struct extent_buffer *leaf; |
4730 | int slot; | |
cfed81a0 CM |
4731 | struct btrfs_map_token token; |
4732 | ||
24cdc847 FM |
4733 | if (path->slots[0] == 0) { |
4734 | btrfs_cpu_key_to_disk(&disk_key, cpu_key); | |
b7a0365e | 4735 | fixup_low_keys(root->fs_info, path, &disk_key, 1); |
24cdc847 FM |
4736 | } |
4737 | btrfs_unlock_up_safe(path, 1); | |
4738 | ||
cfed81a0 | 4739 | btrfs_init_map_token(&token); |
e2fa7227 | 4740 | |
5f39d397 | 4741 | leaf = path->nodes[0]; |
44871b1b | 4742 | slot = path->slots[0]; |
74123bd7 | 4743 | |
5f39d397 | 4744 | nritems = btrfs_header_nritems(leaf); |
123abc88 | 4745 | data_end = leaf_data_end(root, leaf); |
eb60ceac | 4746 | |
f25956cc | 4747 | if (btrfs_leaf_free_space(root, leaf) < total_size) { |
3326d1b0 | 4748 | btrfs_print_leaf(root, leaf); |
5d163e0e JM |
4749 | btrfs_crit(root->fs_info, |
4750 | "not enough freespace need %u have %d", | |
4751 | total_size, btrfs_leaf_free_space(root, leaf)); | |
be0e5c09 | 4752 | BUG(); |
d4dbff95 | 4753 | } |
5f39d397 | 4754 | |
be0e5c09 | 4755 | if (slot != nritems) { |
5f39d397 | 4756 | unsigned int old_data = btrfs_item_end_nr(leaf, slot); |
be0e5c09 | 4757 | |
5f39d397 CM |
4758 | if (old_data < data_end) { |
4759 | btrfs_print_leaf(root, leaf); | |
5d163e0e JM |
4760 | btrfs_crit(root->fs_info, |
4761 | "slot %d old_data %d data_end %d", | |
4762 | slot, old_data, data_end); | |
5f39d397 CM |
4763 | BUG_ON(1); |
4764 | } | |
be0e5c09 CM |
4765 | /* |
4766 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
4767 | */ | |
4768 | /* first correct the data pointers */ | |
0783fcfc | 4769 | for (i = slot; i < nritems; i++) { |
5f39d397 | 4770 | u32 ioff; |
db94535d | 4771 | |
62e85577 | 4772 | item = btrfs_item_nr(i); |
cfed81a0 CM |
4773 | ioff = btrfs_token_item_offset(leaf, item, &token); |
4774 | btrfs_set_token_item_offset(leaf, item, | |
4775 | ioff - total_data, &token); | |
0783fcfc | 4776 | } |
be0e5c09 | 4777 | /* shift the items */ |
9c58309d | 4778 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr), |
5f39d397 | 4779 | btrfs_item_nr_offset(slot), |
d6025579 | 4780 | (nritems - slot) * sizeof(struct btrfs_item)); |
be0e5c09 CM |
4781 | |
4782 | /* shift the data */ | |
5f39d397 | 4783 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + |
9c58309d | 4784 | data_end - total_data, btrfs_leaf_data(leaf) + |
d6025579 | 4785 | data_end, old_data - data_end); |
be0e5c09 CM |
4786 | data_end = old_data; |
4787 | } | |
5f39d397 | 4788 | |
62e2749e | 4789 | /* setup the item for the new data */ |
9c58309d CM |
4790 | for (i = 0; i < nr; i++) { |
4791 | btrfs_cpu_key_to_disk(&disk_key, cpu_key + i); | |
4792 | btrfs_set_item_key(leaf, &disk_key, slot + i); | |
dd3cc16b | 4793 | item = btrfs_item_nr(slot + i); |
cfed81a0 CM |
4794 | btrfs_set_token_item_offset(leaf, item, |
4795 | data_end - data_size[i], &token); | |
9c58309d | 4796 | data_end -= data_size[i]; |
cfed81a0 | 4797 | btrfs_set_token_item_size(leaf, item, data_size[i], &token); |
9c58309d | 4798 | } |
44871b1b | 4799 | |
9c58309d | 4800 | btrfs_set_header_nritems(leaf, nritems + nr); |
b9473439 | 4801 | btrfs_mark_buffer_dirty(leaf); |
aa5d6bed | 4802 | |
5f39d397 CM |
4803 | if (btrfs_leaf_free_space(root, leaf) < 0) { |
4804 | btrfs_print_leaf(root, leaf); | |
be0e5c09 | 4805 | BUG(); |
5f39d397 | 4806 | } |
44871b1b CM |
4807 | } |
4808 | ||
4809 | /* | |
4810 | * Given a key and some data, insert items into the tree. | |
4811 | * This does all the path init required, making room in the tree if needed. | |
4812 | */ | |
4813 | int btrfs_insert_empty_items(struct btrfs_trans_handle *trans, | |
4814 | struct btrfs_root *root, | |
4815 | struct btrfs_path *path, | |
4816 | struct btrfs_key *cpu_key, u32 *data_size, | |
4817 | int nr) | |
4818 | { | |
44871b1b CM |
4819 | int ret = 0; |
4820 | int slot; | |
4821 | int i; | |
4822 | u32 total_size = 0; | |
4823 | u32 total_data = 0; | |
4824 | ||
4825 | for (i = 0; i < nr; i++) | |
4826 | total_data += data_size[i]; | |
4827 | ||
4828 | total_size = total_data + (nr * sizeof(struct btrfs_item)); | |
4829 | ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1); | |
4830 | if (ret == 0) | |
4831 | return -EEXIST; | |
4832 | if (ret < 0) | |
143bede5 | 4833 | return ret; |
44871b1b | 4834 | |
44871b1b CM |
4835 | slot = path->slots[0]; |
4836 | BUG_ON(slot < 0); | |
4837 | ||
afe5fea7 | 4838 | setup_items_for_insert(root, path, cpu_key, data_size, |
44871b1b | 4839 | total_data, total_size, nr); |
143bede5 | 4840 | return 0; |
62e2749e CM |
4841 | } |
4842 | ||
4843 | /* | |
4844 | * Given a key and some data, insert an item into the tree. | |
4845 | * This does all the path init required, making room in the tree if needed. | |
4846 | */ | |
e089f05c CM |
4847 | int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root |
4848 | *root, struct btrfs_key *cpu_key, void *data, u32 | |
4849 | data_size) | |
62e2749e CM |
4850 | { |
4851 | int ret = 0; | |
2c90e5d6 | 4852 | struct btrfs_path *path; |
5f39d397 CM |
4853 | struct extent_buffer *leaf; |
4854 | unsigned long ptr; | |
62e2749e | 4855 | |
2c90e5d6 | 4856 | path = btrfs_alloc_path(); |
db5b493a TI |
4857 | if (!path) |
4858 | return -ENOMEM; | |
2c90e5d6 | 4859 | ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size); |
62e2749e | 4860 | if (!ret) { |
5f39d397 CM |
4861 | leaf = path->nodes[0]; |
4862 | ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); | |
4863 | write_extent_buffer(leaf, data, ptr, data_size); | |
4864 | btrfs_mark_buffer_dirty(leaf); | |
62e2749e | 4865 | } |
2c90e5d6 | 4866 | btrfs_free_path(path); |
aa5d6bed | 4867 | return ret; |
be0e5c09 CM |
4868 | } |
4869 | ||
74123bd7 | 4870 | /* |
5de08d7d | 4871 | * delete the pointer from a given node. |
74123bd7 | 4872 | * |
d352ac68 CM |
4873 | * the tree should have been previously balanced so the deletion does not |
4874 | * empty a node. | |
74123bd7 | 4875 | */ |
afe5fea7 TI |
4876 | static void del_ptr(struct btrfs_root *root, struct btrfs_path *path, |
4877 | int level, int slot) | |
be0e5c09 | 4878 | { |
5f39d397 | 4879 | struct extent_buffer *parent = path->nodes[level]; |
7518a238 | 4880 | u32 nritems; |
f3ea38da | 4881 | int ret; |
be0e5c09 | 4882 | |
5f39d397 | 4883 | nritems = btrfs_header_nritems(parent); |
d397712b | 4884 | if (slot != nritems - 1) { |
0e411ece | 4885 | if (level) |
f3ea38da JS |
4886 | tree_mod_log_eb_move(root->fs_info, parent, slot, |
4887 | slot + 1, nritems - slot - 1); | |
5f39d397 CM |
4888 | memmove_extent_buffer(parent, |
4889 | btrfs_node_key_ptr_offset(slot), | |
4890 | btrfs_node_key_ptr_offset(slot + 1), | |
d6025579 CM |
4891 | sizeof(struct btrfs_key_ptr) * |
4892 | (nritems - slot - 1)); | |
57ba86c0 CM |
4893 | } else if (level) { |
4894 | ret = tree_mod_log_insert_key(root->fs_info, parent, slot, | |
c8cc6341 | 4895 | MOD_LOG_KEY_REMOVE, GFP_NOFS); |
57ba86c0 | 4896 | BUG_ON(ret < 0); |
bb803951 | 4897 | } |
f3ea38da | 4898 | |
7518a238 | 4899 | nritems--; |
5f39d397 | 4900 | btrfs_set_header_nritems(parent, nritems); |
7518a238 | 4901 | if (nritems == 0 && parent == root->node) { |
5f39d397 | 4902 | BUG_ON(btrfs_header_level(root->node) != 1); |
bb803951 | 4903 | /* just turn the root into a leaf and break */ |
5f39d397 | 4904 | btrfs_set_header_level(root->node, 0); |
bb803951 | 4905 | } else if (slot == 0) { |
5f39d397 CM |
4906 | struct btrfs_disk_key disk_key; |
4907 | ||
4908 | btrfs_node_key(parent, &disk_key, 0); | |
b7a0365e | 4909 | fixup_low_keys(root->fs_info, path, &disk_key, level + 1); |
be0e5c09 | 4910 | } |
d6025579 | 4911 | btrfs_mark_buffer_dirty(parent); |
be0e5c09 CM |
4912 | } |
4913 | ||
323ac95b CM |
4914 | /* |
4915 | * a helper function to delete the leaf pointed to by path->slots[1] and | |
5d4f98a2 | 4916 | * path->nodes[1]. |
323ac95b CM |
4917 | * |
4918 | * This deletes the pointer in path->nodes[1] and frees the leaf | |
4919 | * block extent. zero is returned if it all worked out, < 0 otherwise. | |
4920 | * | |
4921 | * The path must have already been setup for deleting the leaf, including | |
4922 | * all the proper balancing. path->nodes[1] must be locked. | |
4923 | */ | |
143bede5 JM |
4924 | static noinline void btrfs_del_leaf(struct btrfs_trans_handle *trans, |
4925 | struct btrfs_root *root, | |
4926 | struct btrfs_path *path, | |
4927 | struct extent_buffer *leaf) | |
323ac95b | 4928 | { |
5d4f98a2 | 4929 | WARN_ON(btrfs_header_generation(leaf) != trans->transid); |
afe5fea7 | 4930 | del_ptr(root, path, 1, path->slots[1]); |
323ac95b | 4931 | |
4d081c41 CM |
4932 | /* |
4933 | * btrfs_free_extent is expensive, we want to make sure we | |
4934 | * aren't holding any locks when we call it | |
4935 | */ | |
4936 | btrfs_unlock_up_safe(path, 0); | |
4937 | ||
f0486c68 YZ |
4938 | root_sub_used(root, leaf->len); |
4939 | ||
3083ee2e | 4940 | extent_buffer_get(leaf); |
5581a51a | 4941 | btrfs_free_tree_block(trans, root, leaf, 0, 1); |
3083ee2e | 4942 | free_extent_buffer_stale(leaf); |
323ac95b | 4943 | } |
74123bd7 CM |
4944 | /* |
4945 | * delete the item at the leaf level in path. If that empties | |
4946 | * the leaf, remove it from the tree | |
4947 | */ | |
85e21bac CM |
4948 | int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
4949 | struct btrfs_path *path, int slot, int nr) | |
be0e5c09 | 4950 | { |
5f39d397 CM |
4951 | struct extent_buffer *leaf; |
4952 | struct btrfs_item *item; | |
ce0eac2a AM |
4953 | u32 last_off; |
4954 | u32 dsize = 0; | |
aa5d6bed CM |
4955 | int ret = 0; |
4956 | int wret; | |
85e21bac | 4957 | int i; |
7518a238 | 4958 | u32 nritems; |
cfed81a0 CM |
4959 | struct btrfs_map_token token; |
4960 | ||
4961 | btrfs_init_map_token(&token); | |
be0e5c09 | 4962 | |
5f39d397 | 4963 | leaf = path->nodes[0]; |
85e21bac CM |
4964 | last_off = btrfs_item_offset_nr(leaf, slot + nr - 1); |
4965 | ||
4966 | for (i = 0; i < nr; i++) | |
4967 | dsize += btrfs_item_size_nr(leaf, slot + i); | |
4968 | ||
5f39d397 | 4969 | nritems = btrfs_header_nritems(leaf); |
be0e5c09 | 4970 | |
85e21bac | 4971 | if (slot + nr != nritems) { |
123abc88 | 4972 | int data_end = leaf_data_end(root, leaf); |
5f39d397 CM |
4973 | |
4974 | memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + | |
d6025579 CM |
4975 | data_end + dsize, |
4976 | btrfs_leaf_data(leaf) + data_end, | |
85e21bac | 4977 | last_off - data_end); |
5f39d397 | 4978 | |
85e21bac | 4979 | for (i = slot + nr; i < nritems; i++) { |
5f39d397 | 4980 | u32 ioff; |
db94535d | 4981 | |
dd3cc16b | 4982 | item = btrfs_item_nr(i); |
cfed81a0 CM |
4983 | ioff = btrfs_token_item_offset(leaf, item, &token); |
4984 | btrfs_set_token_item_offset(leaf, item, | |
4985 | ioff + dsize, &token); | |
0783fcfc | 4986 | } |
db94535d | 4987 | |
5f39d397 | 4988 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot), |
85e21bac | 4989 | btrfs_item_nr_offset(slot + nr), |
d6025579 | 4990 | sizeof(struct btrfs_item) * |
85e21bac | 4991 | (nritems - slot - nr)); |
be0e5c09 | 4992 | } |
85e21bac CM |
4993 | btrfs_set_header_nritems(leaf, nritems - nr); |
4994 | nritems -= nr; | |
5f39d397 | 4995 | |
74123bd7 | 4996 | /* delete the leaf if we've emptied it */ |
7518a238 | 4997 | if (nritems == 0) { |
5f39d397 CM |
4998 | if (leaf == root->node) { |
4999 | btrfs_set_header_level(leaf, 0); | |
9a8dd150 | 5000 | } else { |
f0486c68 | 5001 | btrfs_set_path_blocking(path); |
01d58472 | 5002 | clean_tree_block(trans, root->fs_info, leaf); |
143bede5 | 5003 | btrfs_del_leaf(trans, root, path, leaf); |
9a8dd150 | 5004 | } |
be0e5c09 | 5005 | } else { |
7518a238 | 5006 | int used = leaf_space_used(leaf, 0, nritems); |
aa5d6bed | 5007 | if (slot == 0) { |
5f39d397 CM |
5008 | struct btrfs_disk_key disk_key; |
5009 | ||
5010 | btrfs_item_key(leaf, &disk_key, 0); | |
b7a0365e | 5011 | fixup_low_keys(root->fs_info, path, &disk_key, 1); |
aa5d6bed | 5012 | } |
aa5d6bed | 5013 | |
74123bd7 | 5014 | /* delete the leaf if it is mostly empty */ |
d717aa1d | 5015 | if (used < BTRFS_LEAF_DATA_SIZE(root) / 3) { |
be0e5c09 CM |
5016 | /* push_leaf_left fixes the path. |
5017 | * make sure the path still points to our leaf | |
5018 | * for possible call to del_ptr below | |
5019 | */ | |
4920c9ac | 5020 | slot = path->slots[1]; |
5f39d397 CM |
5021 | extent_buffer_get(leaf); |
5022 | ||
b9473439 | 5023 | btrfs_set_path_blocking(path); |
99d8f83c CM |
5024 | wret = push_leaf_left(trans, root, path, 1, 1, |
5025 | 1, (u32)-1); | |
54aa1f4d | 5026 | if (wret < 0 && wret != -ENOSPC) |
aa5d6bed | 5027 | ret = wret; |
5f39d397 CM |
5028 | |
5029 | if (path->nodes[0] == leaf && | |
5030 | btrfs_header_nritems(leaf)) { | |
99d8f83c CM |
5031 | wret = push_leaf_right(trans, root, path, 1, |
5032 | 1, 1, 0); | |
54aa1f4d | 5033 | if (wret < 0 && wret != -ENOSPC) |
aa5d6bed CM |
5034 | ret = wret; |
5035 | } | |
5f39d397 CM |
5036 | |
5037 | if (btrfs_header_nritems(leaf) == 0) { | |
323ac95b | 5038 | path->slots[1] = slot; |
143bede5 | 5039 | btrfs_del_leaf(trans, root, path, leaf); |
5f39d397 | 5040 | free_extent_buffer(leaf); |
143bede5 | 5041 | ret = 0; |
5de08d7d | 5042 | } else { |
925baedd CM |
5043 | /* if we're still in the path, make sure |
5044 | * we're dirty. Otherwise, one of the | |
5045 | * push_leaf functions must have already | |
5046 | * dirtied this buffer | |
5047 | */ | |
5048 | if (path->nodes[0] == leaf) | |
5049 | btrfs_mark_buffer_dirty(leaf); | |
5f39d397 | 5050 | free_extent_buffer(leaf); |
be0e5c09 | 5051 | } |
d5719762 | 5052 | } else { |
5f39d397 | 5053 | btrfs_mark_buffer_dirty(leaf); |
be0e5c09 CM |
5054 | } |
5055 | } | |
aa5d6bed | 5056 | return ret; |
be0e5c09 CM |
5057 | } |
5058 | ||
7bb86316 | 5059 | /* |
925baedd | 5060 | * search the tree again to find a leaf with lesser keys |
7bb86316 CM |
5061 | * returns 0 if it found something or 1 if there are no lesser leaves. |
5062 | * returns < 0 on io errors. | |
d352ac68 CM |
5063 | * |
5064 | * This may release the path, and so you may lose any locks held at the | |
5065 | * time you call it. | |
7bb86316 | 5066 | */ |
16e7549f | 5067 | int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path) |
7bb86316 | 5068 | { |
925baedd CM |
5069 | struct btrfs_key key; |
5070 | struct btrfs_disk_key found_key; | |
5071 | int ret; | |
7bb86316 | 5072 | |
925baedd | 5073 | btrfs_item_key_to_cpu(path->nodes[0], &key, 0); |
7bb86316 | 5074 | |
e8b0d724 | 5075 | if (key.offset > 0) { |
925baedd | 5076 | key.offset--; |
e8b0d724 | 5077 | } else if (key.type > 0) { |
925baedd | 5078 | key.type--; |
e8b0d724 FDBM |
5079 | key.offset = (u64)-1; |
5080 | } else if (key.objectid > 0) { | |
925baedd | 5081 | key.objectid--; |
e8b0d724 FDBM |
5082 | key.type = (u8)-1; |
5083 | key.offset = (u64)-1; | |
5084 | } else { | |
925baedd | 5085 | return 1; |
e8b0d724 | 5086 | } |
7bb86316 | 5087 | |
b3b4aa74 | 5088 | btrfs_release_path(path); |
925baedd CM |
5089 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
5090 | if (ret < 0) | |
5091 | return ret; | |
5092 | btrfs_item_key(path->nodes[0], &found_key, 0); | |
5093 | ret = comp_keys(&found_key, &key); | |
337c6f68 FM |
5094 | /* |
5095 | * We might have had an item with the previous key in the tree right | |
5096 | * before we released our path. And after we released our path, that | |
5097 | * item might have been pushed to the first slot (0) of the leaf we | |
5098 | * were holding due to a tree balance. Alternatively, an item with the | |
5099 | * previous key can exist as the only element of a leaf (big fat item). | |
5100 | * Therefore account for these 2 cases, so that our callers (like | |
5101 | * btrfs_previous_item) don't miss an existing item with a key matching | |
5102 | * the previous key we computed above. | |
5103 | */ | |
5104 | if (ret <= 0) | |
925baedd CM |
5105 | return 0; |
5106 | return 1; | |
7bb86316 CM |
5107 | } |
5108 | ||
3f157a2f CM |
5109 | /* |
5110 | * A helper function to walk down the tree starting at min_key, and looking | |
de78b51a ES |
5111 | * for nodes or leaves that are have a minimum transaction id. |
5112 | * This is used by the btree defrag code, and tree logging | |
3f157a2f CM |
5113 | * |
5114 | * This does not cow, but it does stuff the starting key it finds back | |
5115 | * into min_key, so you can call btrfs_search_slot with cow=1 on the | |
5116 | * key and get a writable path. | |
5117 | * | |
5118 | * This does lock as it descends, and path->keep_locks should be set | |
5119 | * to 1 by the caller. | |
5120 | * | |
5121 | * This honors path->lowest_level to prevent descent past a given level | |
5122 | * of the tree. | |
5123 | * | |
d352ac68 CM |
5124 | * min_trans indicates the oldest transaction that you are interested |
5125 | * in walking through. Any nodes or leaves older than min_trans are | |
5126 | * skipped over (without reading them). | |
5127 | * | |
3f157a2f CM |
5128 | * returns zero if something useful was found, < 0 on error and 1 if there |
5129 | * was nothing in the tree that matched the search criteria. | |
5130 | */ | |
5131 | int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key, | |
de78b51a | 5132 | struct btrfs_path *path, |
3f157a2f CM |
5133 | u64 min_trans) |
5134 | { | |
5135 | struct extent_buffer *cur; | |
5136 | struct btrfs_key found_key; | |
5137 | int slot; | |
9652480b | 5138 | int sret; |
3f157a2f CM |
5139 | u32 nritems; |
5140 | int level; | |
5141 | int ret = 1; | |
f98de9b9 | 5142 | int keep_locks = path->keep_locks; |
3f157a2f | 5143 | |
f98de9b9 | 5144 | path->keep_locks = 1; |
3f157a2f | 5145 | again: |
bd681513 | 5146 | cur = btrfs_read_lock_root_node(root); |
3f157a2f | 5147 | level = btrfs_header_level(cur); |
e02119d5 | 5148 | WARN_ON(path->nodes[level]); |
3f157a2f | 5149 | path->nodes[level] = cur; |
bd681513 | 5150 | path->locks[level] = BTRFS_READ_LOCK; |
3f157a2f CM |
5151 | |
5152 | if (btrfs_header_generation(cur) < min_trans) { | |
5153 | ret = 1; | |
5154 | goto out; | |
5155 | } | |
d397712b | 5156 | while (1) { |
3f157a2f CM |
5157 | nritems = btrfs_header_nritems(cur); |
5158 | level = btrfs_header_level(cur); | |
9652480b | 5159 | sret = bin_search(cur, min_key, level, &slot); |
3f157a2f | 5160 | |
323ac95b CM |
5161 | /* at the lowest level, we're done, setup the path and exit */ |
5162 | if (level == path->lowest_level) { | |
e02119d5 CM |
5163 | if (slot >= nritems) |
5164 | goto find_next_key; | |
3f157a2f CM |
5165 | ret = 0; |
5166 | path->slots[level] = slot; | |
5167 | btrfs_item_key_to_cpu(cur, &found_key, slot); | |
5168 | goto out; | |
5169 | } | |
9652480b Y |
5170 | if (sret && slot > 0) |
5171 | slot--; | |
3f157a2f | 5172 | /* |
de78b51a ES |
5173 | * check this node pointer against the min_trans parameters. |
5174 | * If it is too old, old, skip to the next one. | |
3f157a2f | 5175 | */ |
d397712b | 5176 | while (slot < nritems) { |
3f157a2f | 5177 | u64 gen; |
e02119d5 | 5178 | |
3f157a2f CM |
5179 | gen = btrfs_node_ptr_generation(cur, slot); |
5180 | if (gen < min_trans) { | |
5181 | slot++; | |
5182 | continue; | |
5183 | } | |
de78b51a | 5184 | break; |
3f157a2f | 5185 | } |
e02119d5 | 5186 | find_next_key: |
3f157a2f CM |
5187 | /* |
5188 | * we didn't find a candidate key in this node, walk forward | |
5189 | * and find another one | |
5190 | */ | |
5191 | if (slot >= nritems) { | |
e02119d5 | 5192 | path->slots[level] = slot; |
b4ce94de | 5193 | btrfs_set_path_blocking(path); |
e02119d5 | 5194 | sret = btrfs_find_next_key(root, path, min_key, level, |
de78b51a | 5195 | min_trans); |
e02119d5 | 5196 | if (sret == 0) { |
b3b4aa74 | 5197 | btrfs_release_path(path); |
3f157a2f CM |
5198 | goto again; |
5199 | } else { | |
5200 | goto out; | |
5201 | } | |
5202 | } | |
5203 | /* save our key for returning back */ | |
5204 | btrfs_node_key_to_cpu(cur, &found_key, slot); | |
5205 | path->slots[level] = slot; | |
5206 | if (level == path->lowest_level) { | |
5207 | ret = 0; | |
3f157a2f CM |
5208 | goto out; |
5209 | } | |
b4ce94de | 5210 | btrfs_set_path_blocking(path); |
3f157a2f | 5211 | cur = read_node_slot(root, cur, slot); |
fb770ae4 LB |
5212 | if (IS_ERR(cur)) { |
5213 | ret = PTR_ERR(cur); | |
5214 | goto out; | |
5215 | } | |
3f157a2f | 5216 | |
bd681513 | 5217 | btrfs_tree_read_lock(cur); |
b4ce94de | 5218 | |
bd681513 | 5219 | path->locks[level - 1] = BTRFS_READ_LOCK; |
3f157a2f | 5220 | path->nodes[level - 1] = cur; |
f7c79f30 | 5221 | unlock_up(path, level, 1, 0, NULL); |
bd681513 | 5222 | btrfs_clear_path_blocking(path, NULL, 0); |
3f157a2f CM |
5223 | } |
5224 | out: | |
f98de9b9 FM |
5225 | path->keep_locks = keep_locks; |
5226 | if (ret == 0) { | |
5227 | btrfs_unlock_up_safe(path, path->lowest_level + 1); | |
5228 | btrfs_set_path_blocking(path); | |
3f157a2f | 5229 | memcpy(min_key, &found_key, sizeof(found_key)); |
f98de9b9 | 5230 | } |
3f157a2f CM |
5231 | return ret; |
5232 | } | |
5233 | ||
fb770ae4 | 5234 | static int tree_move_down(struct btrfs_root *root, |
7069830a AB |
5235 | struct btrfs_path *path, |
5236 | int *level, int root_level) | |
5237 | { | |
fb770ae4 LB |
5238 | struct extent_buffer *eb; |
5239 | ||
74dd17fb | 5240 | BUG_ON(*level == 0); |
fb770ae4 LB |
5241 | eb = read_node_slot(root, path->nodes[*level], path->slots[*level]); |
5242 | if (IS_ERR(eb)) | |
5243 | return PTR_ERR(eb); | |
5244 | ||
5245 | path->nodes[*level - 1] = eb; | |
7069830a AB |
5246 | path->slots[*level - 1] = 0; |
5247 | (*level)--; | |
fb770ae4 | 5248 | return 0; |
7069830a AB |
5249 | } |
5250 | ||
5251 | static int tree_move_next_or_upnext(struct btrfs_root *root, | |
5252 | struct btrfs_path *path, | |
5253 | int *level, int root_level) | |
5254 | { | |
5255 | int ret = 0; | |
5256 | int nritems; | |
5257 | nritems = btrfs_header_nritems(path->nodes[*level]); | |
5258 | ||
5259 | path->slots[*level]++; | |
5260 | ||
74dd17fb | 5261 | while (path->slots[*level] >= nritems) { |
7069830a AB |
5262 | if (*level == root_level) |
5263 | return -1; | |
5264 | ||
5265 | /* move upnext */ | |
5266 | path->slots[*level] = 0; | |
5267 | free_extent_buffer(path->nodes[*level]); | |
5268 | path->nodes[*level] = NULL; | |
5269 | (*level)++; | |
5270 | path->slots[*level]++; | |
5271 | ||
5272 | nritems = btrfs_header_nritems(path->nodes[*level]); | |
5273 | ret = 1; | |
5274 | } | |
5275 | return ret; | |
5276 | } | |
5277 | ||
5278 | /* | |
5279 | * Returns 1 if it had to move up and next. 0 is returned if it moved only next | |
5280 | * or down. | |
5281 | */ | |
5282 | static int tree_advance(struct btrfs_root *root, | |
5283 | struct btrfs_path *path, | |
5284 | int *level, int root_level, | |
5285 | int allow_down, | |
5286 | struct btrfs_key *key) | |
5287 | { | |
5288 | int ret; | |
5289 | ||
5290 | if (*level == 0 || !allow_down) { | |
5291 | ret = tree_move_next_or_upnext(root, path, level, root_level); | |
5292 | } else { | |
fb770ae4 | 5293 | ret = tree_move_down(root, path, level, root_level); |
7069830a AB |
5294 | } |
5295 | if (ret >= 0) { | |
5296 | if (*level == 0) | |
5297 | btrfs_item_key_to_cpu(path->nodes[*level], key, | |
5298 | path->slots[*level]); | |
5299 | else | |
5300 | btrfs_node_key_to_cpu(path->nodes[*level], key, | |
5301 | path->slots[*level]); | |
5302 | } | |
5303 | return ret; | |
5304 | } | |
5305 | ||
5306 | static int tree_compare_item(struct btrfs_root *left_root, | |
5307 | struct btrfs_path *left_path, | |
5308 | struct btrfs_path *right_path, | |
5309 | char *tmp_buf) | |
5310 | { | |
5311 | int cmp; | |
5312 | int len1, len2; | |
5313 | unsigned long off1, off2; | |
5314 | ||
5315 | len1 = btrfs_item_size_nr(left_path->nodes[0], left_path->slots[0]); | |
5316 | len2 = btrfs_item_size_nr(right_path->nodes[0], right_path->slots[0]); | |
5317 | if (len1 != len2) | |
5318 | return 1; | |
5319 | ||
5320 | off1 = btrfs_item_ptr_offset(left_path->nodes[0], left_path->slots[0]); | |
5321 | off2 = btrfs_item_ptr_offset(right_path->nodes[0], | |
5322 | right_path->slots[0]); | |
5323 | ||
5324 | read_extent_buffer(left_path->nodes[0], tmp_buf, off1, len1); | |
5325 | ||
5326 | cmp = memcmp_extent_buffer(right_path->nodes[0], tmp_buf, off2, len1); | |
5327 | if (cmp) | |
5328 | return 1; | |
5329 | return 0; | |
5330 | } | |
5331 | ||
5332 | #define ADVANCE 1 | |
5333 | #define ADVANCE_ONLY_NEXT -1 | |
5334 | ||
5335 | /* | |
5336 | * This function compares two trees and calls the provided callback for | |
5337 | * every changed/new/deleted item it finds. | |
5338 | * If shared tree blocks are encountered, whole subtrees are skipped, making | |
5339 | * the compare pretty fast on snapshotted subvolumes. | |
5340 | * | |
5341 | * This currently works on commit roots only. As commit roots are read only, | |
5342 | * we don't do any locking. The commit roots are protected with transactions. | |
5343 | * Transactions are ended and rejoined when a commit is tried in between. | |
5344 | * | |
5345 | * This function checks for modifications done to the trees while comparing. | |
5346 | * If it detects a change, it aborts immediately. | |
5347 | */ | |
5348 | int btrfs_compare_trees(struct btrfs_root *left_root, | |
5349 | struct btrfs_root *right_root, | |
5350 | btrfs_changed_cb_t changed_cb, void *ctx) | |
5351 | { | |
5352 | int ret; | |
5353 | int cmp; | |
7069830a AB |
5354 | struct btrfs_path *left_path = NULL; |
5355 | struct btrfs_path *right_path = NULL; | |
5356 | struct btrfs_key left_key; | |
5357 | struct btrfs_key right_key; | |
5358 | char *tmp_buf = NULL; | |
5359 | int left_root_level; | |
5360 | int right_root_level; | |
5361 | int left_level; | |
5362 | int right_level; | |
5363 | int left_end_reached; | |
5364 | int right_end_reached; | |
5365 | int advance_left; | |
5366 | int advance_right; | |
5367 | u64 left_blockptr; | |
5368 | u64 right_blockptr; | |
6baa4293 FM |
5369 | u64 left_gen; |
5370 | u64 right_gen; | |
7069830a AB |
5371 | |
5372 | left_path = btrfs_alloc_path(); | |
5373 | if (!left_path) { | |
5374 | ret = -ENOMEM; | |
5375 | goto out; | |
5376 | } | |
5377 | right_path = btrfs_alloc_path(); | |
5378 | if (!right_path) { | |
5379 | ret = -ENOMEM; | |
5380 | goto out; | |
5381 | } | |
5382 | ||
8f282f71 | 5383 | tmp_buf = kmalloc(left_root->nodesize, GFP_KERNEL | __GFP_NOWARN); |
7069830a | 5384 | if (!tmp_buf) { |
8f282f71 DS |
5385 | tmp_buf = vmalloc(left_root->nodesize); |
5386 | if (!tmp_buf) { | |
5387 | ret = -ENOMEM; | |
5388 | goto out; | |
5389 | } | |
7069830a AB |
5390 | } |
5391 | ||
5392 | left_path->search_commit_root = 1; | |
5393 | left_path->skip_locking = 1; | |
5394 | right_path->search_commit_root = 1; | |
5395 | right_path->skip_locking = 1; | |
5396 | ||
7069830a AB |
5397 | /* |
5398 | * Strategy: Go to the first items of both trees. Then do | |
5399 | * | |
5400 | * If both trees are at level 0 | |
5401 | * Compare keys of current items | |
5402 | * If left < right treat left item as new, advance left tree | |
5403 | * and repeat | |
5404 | * If left > right treat right item as deleted, advance right tree | |
5405 | * and repeat | |
5406 | * If left == right do deep compare of items, treat as changed if | |
5407 | * needed, advance both trees and repeat | |
5408 | * If both trees are at the same level but not at level 0 | |
5409 | * Compare keys of current nodes/leafs | |
5410 | * If left < right advance left tree and repeat | |
5411 | * If left > right advance right tree and repeat | |
5412 | * If left == right compare blockptrs of the next nodes/leafs | |
5413 | * If they match advance both trees but stay at the same level | |
5414 | * and repeat | |
5415 | * If they don't match advance both trees while allowing to go | |
5416 | * deeper and repeat | |
5417 | * If tree levels are different | |
5418 | * Advance the tree that needs it and repeat | |
5419 | * | |
5420 | * Advancing a tree means: | |
5421 | * If we are at level 0, try to go to the next slot. If that's not | |
5422 | * possible, go one level up and repeat. Stop when we found a level | |
5423 | * where we could go to the next slot. We may at this point be on a | |
5424 | * node or a leaf. | |
5425 | * | |
5426 | * If we are not at level 0 and not on shared tree blocks, go one | |
5427 | * level deeper. | |
5428 | * | |
5429 | * If we are not at level 0 and on shared tree blocks, go one slot to | |
5430 | * the right if possible or go up and right. | |
5431 | */ | |
5432 | ||
3f8a18cc | 5433 | down_read(&left_root->fs_info->commit_root_sem); |
7069830a AB |
5434 | left_level = btrfs_header_level(left_root->commit_root); |
5435 | left_root_level = left_level; | |
5436 | left_path->nodes[left_level] = left_root->commit_root; | |
5437 | extent_buffer_get(left_path->nodes[left_level]); | |
5438 | ||
5439 | right_level = btrfs_header_level(right_root->commit_root); | |
5440 | right_root_level = right_level; | |
5441 | right_path->nodes[right_level] = right_root->commit_root; | |
5442 | extent_buffer_get(right_path->nodes[right_level]); | |
3f8a18cc | 5443 | up_read(&left_root->fs_info->commit_root_sem); |
7069830a AB |
5444 | |
5445 | if (left_level == 0) | |
5446 | btrfs_item_key_to_cpu(left_path->nodes[left_level], | |
5447 | &left_key, left_path->slots[left_level]); | |
5448 | else | |
5449 | btrfs_node_key_to_cpu(left_path->nodes[left_level], | |
5450 | &left_key, left_path->slots[left_level]); | |
5451 | if (right_level == 0) | |
5452 | btrfs_item_key_to_cpu(right_path->nodes[right_level], | |
5453 | &right_key, right_path->slots[right_level]); | |
5454 | else | |
5455 | btrfs_node_key_to_cpu(right_path->nodes[right_level], | |
5456 | &right_key, right_path->slots[right_level]); | |
5457 | ||
5458 | left_end_reached = right_end_reached = 0; | |
5459 | advance_left = advance_right = 0; | |
5460 | ||
5461 | while (1) { | |
7069830a AB |
5462 | if (advance_left && !left_end_reached) { |
5463 | ret = tree_advance(left_root, left_path, &left_level, | |
5464 | left_root_level, | |
5465 | advance_left != ADVANCE_ONLY_NEXT, | |
5466 | &left_key); | |
fb770ae4 | 5467 | if (ret == -1) |
7069830a | 5468 | left_end_reached = ADVANCE; |
fb770ae4 LB |
5469 | else if (ret < 0) |
5470 | goto out; | |
7069830a AB |
5471 | advance_left = 0; |
5472 | } | |
5473 | if (advance_right && !right_end_reached) { | |
5474 | ret = tree_advance(right_root, right_path, &right_level, | |
5475 | right_root_level, | |
5476 | advance_right != ADVANCE_ONLY_NEXT, | |
5477 | &right_key); | |
fb770ae4 | 5478 | if (ret == -1) |
7069830a | 5479 | right_end_reached = ADVANCE; |
fb770ae4 LB |
5480 | else if (ret < 0) |
5481 | goto out; | |
7069830a AB |
5482 | advance_right = 0; |
5483 | } | |
5484 | ||
5485 | if (left_end_reached && right_end_reached) { | |
5486 | ret = 0; | |
5487 | goto out; | |
5488 | } else if (left_end_reached) { | |
5489 | if (right_level == 0) { | |
5490 | ret = changed_cb(left_root, right_root, | |
5491 | left_path, right_path, | |
5492 | &right_key, | |
5493 | BTRFS_COMPARE_TREE_DELETED, | |
5494 | ctx); | |
5495 | if (ret < 0) | |
5496 | goto out; | |
5497 | } | |
5498 | advance_right = ADVANCE; | |
5499 | continue; | |
5500 | } else if (right_end_reached) { | |
5501 | if (left_level == 0) { | |
5502 | ret = changed_cb(left_root, right_root, | |
5503 | left_path, right_path, | |
5504 | &left_key, | |
5505 | BTRFS_COMPARE_TREE_NEW, | |
5506 | ctx); | |
5507 | if (ret < 0) | |
5508 | goto out; | |
5509 | } | |
5510 | advance_left = ADVANCE; | |
5511 | continue; | |
5512 | } | |
5513 | ||
5514 | if (left_level == 0 && right_level == 0) { | |
5515 | cmp = btrfs_comp_cpu_keys(&left_key, &right_key); | |
5516 | if (cmp < 0) { | |
5517 | ret = changed_cb(left_root, right_root, | |
5518 | left_path, right_path, | |
5519 | &left_key, | |
5520 | BTRFS_COMPARE_TREE_NEW, | |
5521 | ctx); | |
5522 | if (ret < 0) | |
5523 | goto out; | |
5524 | advance_left = ADVANCE; | |
5525 | } else if (cmp > 0) { | |
5526 | ret = changed_cb(left_root, right_root, | |
5527 | left_path, right_path, | |
5528 | &right_key, | |
5529 | BTRFS_COMPARE_TREE_DELETED, | |
5530 | ctx); | |
5531 | if (ret < 0) | |
5532 | goto out; | |
5533 | advance_right = ADVANCE; | |
5534 | } else { | |
b99d9a6a | 5535 | enum btrfs_compare_tree_result result; |
ba5e8f2e | 5536 | |
74dd17fb | 5537 | WARN_ON(!extent_buffer_uptodate(left_path->nodes[0])); |
7069830a AB |
5538 | ret = tree_compare_item(left_root, left_path, |
5539 | right_path, tmp_buf); | |
ba5e8f2e | 5540 | if (ret) |
b99d9a6a | 5541 | result = BTRFS_COMPARE_TREE_CHANGED; |
ba5e8f2e | 5542 | else |
b99d9a6a | 5543 | result = BTRFS_COMPARE_TREE_SAME; |
ba5e8f2e JB |
5544 | ret = changed_cb(left_root, right_root, |
5545 | left_path, right_path, | |
b99d9a6a | 5546 | &left_key, result, ctx); |
ba5e8f2e JB |
5547 | if (ret < 0) |
5548 | goto out; | |
7069830a AB |
5549 | advance_left = ADVANCE; |
5550 | advance_right = ADVANCE; | |
5551 | } | |
5552 | } else if (left_level == right_level) { | |
5553 | cmp = btrfs_comp_cpu_keys(&left_key, &right_key); | |
5554 | if (cmp < 0) { | |
5555 | advance_left = ADVANCE; | |
5556 | } else if (cmp > 0) { | |
5557 | advance_right = ADVANCE; | |
5558 | } else { | |
5559 | left_blockptr = btrfs_node_blockptr( | |
5560 | left_path->nodes[left_level], | |
5561 | left_path->slots[left_level]); | |
5562 | right_blockptr = btrfs_node_blockptr( | |
5563 | right_path->nodes[right_level], | |
5564 | right_path->slots[right_level]); | |
6baa4293 FM |
5565 | left_gen = btrfs_node_ptr_generation( |
5566 | left_path->nodes[left_level], | |
5567 | left_path->slots[left_level]); | |
5568 | right_gen = btrfs_node_ptr_generation( | |
5569 | right_path->nodes[right_level], | |
5570 | right_path->slots[right_level]); | |
5571 | if (left_blockptr == right_blockptr && | |
5572 | left_gen == right_gen) { | |
7069830a AB |
5573 | /* |
5574 | * As we're on a shared block, don't | |
5575 | * allow to go deeper. | |
5576 | */ | |
5577 | advance_left = ADVANCE_ONLY_NEXT; | |
5578 | advance_right = ADVANCE_ONLY_NEXT; | |
5579 | } else { | |
5580 | advance_left = ADVANCE; | |
5581 | advance_right = ADVANCE; | |
5582 | } | |
5583 | } | |
5584 | } else if (left_level < right_level) { | |
5585 | advance_right = ADVANCE; | |
5586 | } else { | |
5587 | advance_left = ADVANCE; | |
5588 | } | |
5589 | } | |
5590 | ||
5591 | out: | |
5592 | btrfs_free_path(left_path); | |
5593 | btrfs_free_path(right_path); | |
8f282f71 | 5594 | kvfree(tmp_buf); |
7069830a AB |
5595 | return ret; |
5596 | } | |
5597 | ||
3f157a2f CM |
5598 | /* |
5599 | * this is similar to btrfs_next_leaf, but does not try to preserve | |
5600 | * and fixup the path. It looks for and returns the next key in the | |
de78b51a | 5601 | * tree based on the current path and the min_trans parameters. |
3f157a2f CM |
5602 | * |
5603 | * 0 is returned if another key is found, < 0 if there are any errors | |
5604 | * and 1 is returned if there are no higher keys in the tree | |
5605 | * | |
5606 | * path->keep_locks should be set to 1 on the search made before | |
5607 | * calling this function. | |
5608 | */ | |
e7a84565 | 5609 | int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path, |
de78b51a | 5610 | struct btrfs_key *key, int level, u64 min_trans) |
e7a84565 | 5611 | { |
e7a84565 CM |
5612 | int slot; |
5613 | struct extent_buffer *c; | |
5614 | ||
934d375b | 5615 | WARN_ON(!path->keep_locks); |
d397712b | 5616 | while (level < BTRFS_MAX_LEVEL) { |
e7a84565 CM |
5617 | if (!path->nodes[level]) |
5618 | return 1; | |
5619 | ||
5620 | slot = path->slots[level] + 1; | |
5621 | c = path->nodes[level]; | |
3f157a2f | 5622 | next: |
e7a84565 | 5623 | if (slot >= btrfs_header_nritems(c)) { |
33c66f43 YZ |
5624 | int ret; |
5625 | int orig_lowest; | |
5626 | struct btrfs_key cur_key; | |
5627 | if (level + 1 >= BTRFS_MAX_LEVEL || | |
5628 | !path->nodes[level + 1]) | |
e7a84565 | 5629 | return 1; |
33c66f43 YZ |
5630 | |
5631 | if (path->locks[level + 1]) { | |
5632 | level++; | |
5633 | continue; | |
5634 | } | |
5635 | ||
5636 | slot = btrfs_header_nritems(c) - 1; | |
5637 | if (level == 0) | |
5638 | btrfs_item_key_to_cpu(c, &cur_key, slot); | |
5639 | else | |
5640 | btrfs_node_key_to_cpu(c, &cur_key, slot); | |
5641 | ||
5642 | orig_lowest = path->lowest_level; | |
b3b4aa74 | 5643 | btrfs_release_path(path); |
33c66f43 YZ |
5644 | path->lowest_level = level; |
5645 | ret = btrfs_search_slot(NULL, root, &cur_key, path, | |
5646 | 0, 0); | |
5647 | path->lowest_level = orig_lowest; | |
5648 | if (ret < 0) | |
5649 | return ret; | |
5650 | ||
5651 | c = path->nodes[level]; | |
5652 | slot = path->slots[level]; | |
5653 | if (ret == 0) | |
5654 | slot++; | |
5655 | goto next; | |
e7a84565 | 5656 | } |
33c66f43 | 5657 | |
e7a84565 CM |
5658 | if (level == 0) |
5659 | btrfs_item_key_to_cpu(c, key, slot); | |
3f157a2f | 5660 | else { |
3f157a2f CM |
5661 | u64 gen = btrfs_node_ptr_generation(c, slot); |
5662 | ||
3f157a2f CM |
5663 | if (gen < min_trans) { |
5664 | slot++; | |
5665 | goto next; | |
5666 | } | |
e7a84565 | 5667 | btrfs_node_key_to_cpu(c, key, slot); |
3f157a2f | 5668 | } |
e7a84565 CM |
5669 | return 0; |
5670 | } | |
5671 | return 1; | |
5672 | } | |
5673 | ||
97571fd0 | 5674 | /* |
925baedd | 5675 | * search the tree again to find a leaf with greater keys |
0f70abe2 CM |
5676 | * returns 0 if it found something or 1 if there are no greater leaves. |
5677 | * returns < 0 on io errors. | |
97571fd0 | 5678 | */ |
234b63a0 | 5679 | int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path) |
3d7806ec JS |
5680 | { |
5681 | return btrfs_next_old_leaf(root, path, 0); | |
5682 | } | |
5683 | ||
5684 | int btrfs_next_old_leaf(struct btrfs_root *root, struct btrfs_path *path, | |
5685 | u64 time_seq) | |
d97e63b6 CM |
5686 | { |
5687 | int slot; | |
8e73f275 | 5688 | int level; |
5f39d397 | 5689 | struct extent_buffer *c; |
8e73f275 | 5690 | struct extent_buffer *next; |
925baedd CM |
5691 | struct btrfs_key key; |
5692 | u32 nritems; | |
5693 | int ret; | |
8e73f275 | 5694 | int old_spinning = path->leave_spinning; |
bd681513 | 5695 | int next_rw_lock = 0; |
925baedd CM |
5696 | |
5697 | nritems = btrfs_header_nritems(path->nodes[0]); | |
d397712b | 5698 | if (nritems == 0) |
925baedd | 5699 | return 1; |
925baedd | 5700 | |
8e73f275 CM |
5701 | btrfs_item_key_to_cpu(path->nodes[0], &key, nritems - 1); |
5702 | again: | |
5703 | level = 1; | |
5704 | next = NULL; | |
bd681513 | 5705 | next_rw_lock = 0; |
b3b4aa74 | 5706 | btrfs_release_path(path); |
8e73f275 | 5707 | |
a2135011 | 5708 | path->keep_locks = 1; |
31533fb2 | 5709 | path->leave_spinning = 1; |
8e73f275 | 5710 | |
3d7806ec JS |
5711 | if (time_seq) |
5712 | ret = btrfs_search_old_slot(root, &key, path, time_seq); | |
5713 | else | |
5714 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); | |
925baedd CM |
5715 | path->keep_locks = 0; |
5716 | ||
5717 | if (ret < 0) | |
5718 | return ret; | |
5719 | ||
a2135011 | 5720 | nritems = btrfs_header_nritems(path->nodes[0]); |
168fd7d2 CM |
5721 | /* |
5722 | * by releasing the path above we dropped all our locks. A balance | |
5723 | * could have added more items next to the key that used to be | |
5724 | * at the very end of the block. So, check again here and | |
5725 | * advance the path if there are now more items available. | |
5726 | */ | |
a2135011 | 5727 | if (nritems > 0 && path->slots[0] < nritems - 1) { |
e457afec YZ |
5728 | if (ret == 0) |
5729 | path->slots[0]++; | |
8e73f275 | 5730 | ret = 0; |
925baedd CM |
5731 | goto done; |
5732 | } | |
0b43e04f LB |
5733 | /* |
5734 | * So the above check misses one case: | |
5735 | * - after releasing the path above, someone has removed the item that | |
5736 | * used to be at the very end of the block, and balance between leafs | |
5737 | * gets another one with bigger key.offset to replace it. | |
5738 | * | |
5739 | * This one should be returned as well, or we can get leaf corruption | |
5740 | * later(esp. in __btrfs_drop_extents()). | |
5741 | * | |
5742 | * And a bit more explanation about this check, | |
5743 | * with ret > 0, the key isn't found, the path points to the slot | |
5744 | * where it should be inserted, so the path->slots[0] item must be the | |
5745 | * bigger one. | |
5746 | */ | |
5747 | if (nritems > 0 && ret > 0 && path->slots[0] == nritems - 1) { | |
5748 | ret = 0; | |
5749 | goto done; | |
5750 | } | |
d97e63b6 | 5751 | |
d397712b | 5752 | while (level < BTRFS_MAX_LEVEL) { |
8e73f275 CM |
5753 | if (!path->nodes[level]) { |
5754 | ret = 1; | |
5755 | goto done; | |
5756 | } | |
5f39d397 | 5757 | |
d97e63b6 CM |
5758 | slot = path->slots[level] + 1; |
5759 | c = path->nodes[level]; | |
5f39d397 | 5760 | if (slot >= btrfs_header_nritems(c)) { |
d97e63b6 | 5761 | level++; |
8e73f275 CM |
5762 | if (level == BTRFS_MAX_LEVEL) { |
5763 | ret = 1; | |
5764 | goto done; | |
5765 | } | |
d97e63b6 CM |
5766 | continue; |
5767 | } | |
5f39d397 | 5768 | |
925baedd | 5769 | if (next) { |
bd681513 | 5770 | btrfs_tree_unlock_rw(next, next_rw_lock); |
5f39d397 | 5771 | free_extent_buffer(next); |
925baedd | 5772 | } |
5f39d397 | 5773 | |
8e73f275 | 5774 | next = c; |
bd681513 | 5775 | next_rw_lock = path->locks[level]; |
8e73f275 | 5776 | ret = read_block_for_search(NULL, root, path, &next, level, |
5d9e75c4 | 5777 | slot, &key, 0); |
8e73f275 CM |
5778 | if (ret == -EAGAIN) |
5779 | goto again; | |
5f39d397 | 5780 | |
76a05b35 | 5781 | if (ret < 0) { |
b3b4aa74 | 5782 | btrfs_release_path(path); |
76a05b35 CM |
5783 | goto done; |
5784 | } | |
5785 | ||
5cd57b2c | 5786 | if (!path->skip_locking) { |
bd681513 | 5787 | ret = btrfs_try_tree_read_lock(next); |
d42244a0 JS |
5788 | if (!ret && time_seq) { |
5789 | /* | |
5790 | * If we don't get the lock, we may be racing | |
5791 | * with push_leaf_left, holding that lock while | |
5792 | * itself waiting for the leaf we've currently | |
5793 | * locked. To solve this situation, we give up | |
5794 | * on our lock and cycle. | |
5795 | */ | |
cf538830 | 5796 | free_extent_buffer(next); |
d42244a0 JS |
5797 | btrfs_release_path(path); |
5798 | cond_resched(); | |
5799 | goto again; | |
5800 | } | |
8e73f275 CM |
5801 | if (!ret) { |
5802 | btrfs_set_path_blocking(path); | |
bd681513 | 5803 | btrfs_tree_read_lock(next); |
31533fb2 | 5804 | btrfs_clear_path_blocking(path, next, |
bd681513 | 5805 | BTRFS_READ_LOCK); |
8e73f275 | 5806 | } |
31533fb2 | 5807 | next_rw_lock = BTRFS_READ_LOCK; |
5cd57b2c | 5808 | } |
d97e63b6 CM |
5809 | break; |
5810 | } | |
5811 | path->slots[level] = slot; | |
d397712b | 5812 | while (1) { |
d97e63b6 CM |
5813 | level--; |
5814 | c = path->nodes[level]; | |
925baedd | 5815 | if (path->locks[level]) |
bd681513 | 5816 | btrfs_tree_unlock_rw(c, path->locks[level]); |
8e73f275 | 5817 | |
5f39d397 | 5818 | free_extent_buffer(c); |
d97e63b6 CM |
5819 | path->nodes[level] = next; |
5820 | path->slots[level] = 0; | |
a74a4b97 | 5821 | if (!path->skip_locking) |
bd681513 | 5822 | path->locks[level] = next_rw_lock; |
d97e63b6 CM |
5823 | if (!level) |
5824 | break; | |
b4ce94de | 5825 | |
8e73f275 | 5826 | ret = read_block_for_search(NULL, root, path, &next, level, |
5d9e75c4 | 5827 | 0, &key, 0); |
8e73f275 CM |
5828 | if (ret == -EAGAIN) |
5829 | goto again; | |
5830 | ||
76a05b35 | 5831 | if (ret < 0) { |
b3b4aa74 | 5832 | btrfs_release_path(path); |
76a05b35 CM |
5833 | goto done; |
5834 | } | |
5835 | ||
5cd57b2c | 5836 | if (!path->skip_locking) { |
bd681513 | 5837 | ret = btrfs_try_tree_read_lock(next); |
8e73f275 CM |
5838 | if (!ret) { |
5839 | btrfs_set_path_blocking(path); | |
bd681513 | 5840 | btrfs_tree_read_lock(next); |
31533fb2 | 5841 | btrfs_clear_path_blocking(path, next, |
bd681513 CM |
5842 | BTRFS_READ_LOCK); |
5843 | } | |
31533fb2 | 5844 | next_rw_lock = BTRFS_READ_LOCK; |
5cd57b2c | 5845 | } |
d97e63b6 | 5846 | } |
8e73f275 | 5847 | ret = 0; |
925baedd | 5848 | done: |
f7c79f30 | 5849 | unlock_up(path, 0, 1, 0, NULL); |
8e73f275 CM |
5850 | path->leave_spinning = old_spinning; |
5851 | if (!old_spinning) | |
5852 | btrfs_set_path_blocking(path); | |
5853 | ||
5854 | return ret; | |
d97e63b6 | 5855 | } |
0b86a832 | 5856 | |
3f157a2f CM |
5857 | /* |
5858 | * this uses btrfs_prev_leaf to walk backwards in the tree, and keeps | |
5859 | * searching until it gets past min_objectid or finds an item of 'type' | |
5860 | * | |
5861 | * returns 0 if something is found, 1 if nothing was found and < 0 on error | |
5862 | */ | |
0b86a832 CM |
5863 | int btrfs_previous_item(struct btrfs_root *root, |
5864 | struct btrfs_path *path, u64 min_objectid, | |
5865 | int type) | |
5866 | { | |
5867 | struct btrfs_key found_key; | |
5868 | struct extent_buffer *leaf; | |
e02119d5 | 5869 | u32 nritems; |
0b86a832 CM |
5870 | int ret; |
5871 | ||
d397712b | 5872 | while (1) { |
0b86a832 | 5873 | if (path->slots[0] == 0) { |
b4ce94de | 5874 | btrfs_set_path_blocking(path); |
0b86a832 CM |
5875 | ret = btrfs_prev_leaf(root, path); |
5876 | if (ret != 0) | |
5877 | return ret; | |
5878 | } else { | |
5879 | path->slots[0]--; | |
5880 | } | |
5881 | leaf = path->nodes[0]; | |
e02119d5 CM |
5882 | nritems = btrfs_header_nritems(leaf); |
5883 | if (nritems == 0) | |
5884 | return 1; | |
5885 | if (path->slots[0] == nritems) | |
5886 | path->slots[0]--; | |
5887 | ||
0b86a832 | 5888 | btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); |
e02119d5 CM |
5889 | if (found_key.objectid < min_objectid) |
5890 | break; | |
0a4eefbb YZ |
5891 | if (found_key.type == type) |
5892 | return 0; | |
e02119d5 CM |
5893 | if (found_key.objectid == min_objectid && |
5894 | found_key.type < type) | |
5895 | break; | |
0b86a832 CM |
5896 | } |
5897 | return 1; | |
5898 | } | |
ade2e0b3 WS |
5899 | |
5900 | /* | |
5901 | * search in extent tree to find a previous Metadata/Data extent item with | |
5902 | * min objecitd. | |
5903 | * | |
5904 | * returns 0 if something is found, 1 if nothing was found and < 0 on error | |
5905 | */ | |
5906 | int btrfs_previous_extent_item(struct btrfs_root *root, | |
5907 | struct btrfs_path *path, u64 min_objectid) | |
5908 | { | |
5909 | struct btrfs_key found_key; | |
5910 | struct extent_buffer *leaf; | |
5911 | u32 nritems; | |
5912 | int ret; | |
5913 | ||
5914 | while (1) { | |
5915 | if (path->slots[0] == 0) { | |
5916 | btrfs_set_path_blocking(path); | |
5917 | ret = btrfs_prev_leaf(root, path); | |
5918 | if (ret != 0) | |
5919 | return ret; | |
5920 | } else { | |
5921 | path->slots[0]--; | |
5922 | } | |
5923 | leaf = path->nodes[0]; | |
5924 | nritems = btrfs_header_nritems(leaf); | |
5925 | if (nritems == 0) | |
5926 | return 1; | |
5927 | if (path->slots[0] == nritems) | |
5928 | path->slots[0]--; | |
5929 | ||
5930 | btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); | |
5931 | if (found_key.objectid < min_objectid) | |
5932 | break; | |
5933 | if (found_key.type == BTRFS_EXTENT_ITEM_KEY || | |
5934 | found_key.type == BTRFS_METADATA_ITEM_KEY) | |
5935 | return 0; | |
5936 | if (found_key.objectid == min_objectid && | |
5937 | found_key.type < BTRFS_EXTENT_ITEM_KEY) | |
5938 | break; | |
5939 | } | |
5940 | return 1; | |
5941 | } |