Commit | Line | Data |
---|---|---|
c1d7c514 | 1 | // SPDX-License-Identifier: GPL-2.0 |
6cbd5570 | 2 | /* |
d352ac68 | 3 | * Copyright (C) 2007,2008 Oracle. All rights reserved. |
6cbd5570 CM |
4 | */ |
5 | ||
a6b6e75e | 6 | #include <linux/sched.h> |
5a0e3ad6 | 7 | #include <linux/slab.h> |
bd989ba3 | 8 | #include <linux/rbtree.h> |
adf02123 | 9 | #include <linux/mm.h> |
eb60ceac CM |
10 | #include "ctree.h" |
11 | #include "disk-io.h" | |
7f5c1516 | 12 | #include "transaction.h" |
5f39d397 | 13 | #include "print-tree.h" |
925baedd | 14 | #include "locking.h" |
de37aa51 | 15 | #include "volumes.h" |
9a8dd150 | 16 | |
e089f05c CM |
17 | static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root |
18 | *root, struct btrfs_path *path, int level); | |
310712b2 OS |
19 | static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
20 | const struct btrfs_key *ins_key, struct btrfs_path *path, | |
21 | int data_size, int extend); | |
5f39d397 | 22 | static int push_node_left(struct btrfs_trans_handle *trans, |
2ff7e61e JM |
23 | struct btrfs_fs_info *fs_info, |
24 | struct extent_buffer *dst, | |
971a1f66 | 25 | struct extent_buffer *src, int empty); |
5f39d397 | 26 | static int balance_node_right(struct btrfs_trans_handle *trans, |
2ff7e61e | 27 | struct btrfs_fs_info *fs_info, |
5f39d397 CM |
28 | struct extent_buffer *dst_buf, |
29 | struct extent_buffer *src_buf); | |
afe5fea7 TI |
30 | static void del_ptr(struct btrfs_root *root, struct btrfs_path *path, |
31 | int level, int slot); | |
d97e63b6 | 32 | |
df24a2b9 | 33 | struct btrfs_path *btrfs_alloc_path(void) |
2c90e5d6 | 34 | { |
e2c89907 | 35 | return kmem_cache_zalloc(btrfs_path_cachep, GFP_NOFS); |
2c90e5d6 CM |
36 | } |
37 | ||
b4ce94de CM |
38 | /* |
39 | * set all locked nodes in the path to blocking locks. This should | |
40 | * be done before scheduling | |
41 | */ | |
42 | noinline void btrfs_set_path_blocking(struct btrfs_path *p) | |
43 | { | |
44 | int i; | |
45 | for (i = 0; i < BTRFS_MAX_LEVEL; i++) { | |
bd681513 CM |
46 | if (!p->nodes[i] || !p->locks[i]) |
47 | continue; | |
48 | btrfs_set_lock_blocking_rw(p->nodes[i], p->locks[i]); | |
49 | if (p->locks[i] == BTRFS_READ_LOCK) | |
50 | p->locks[i] = BTRFS_READ_LOCK_BLOCKING; | |
51 | else if (p->locks[i] == BTRFS_WRITE_LOCK) | |
52 | p->locks[i] = BTRFS_WRITE_LOCK_BLOCKING; | |
b4ce94de CM |
53 | } |
54 | } | |
55 | ||
d352ac68 | 56 | /* this also releases the path */ |
df24a2b9 | 57 | void btrfs_free_path(struct btrfs_path *p) |
be0e5c09 | 58 | { |
ff175d57 JJ |
59 | if (!p) |
60 | return; | |
b3b4aa74 | 61 | btrfs_release_path(p); |
df24a2b9 | 62 | kmem_cache_free(btrfs_path_cachep, p); |
be0e5c09 CM |
63 | } |
64 | ||
d352ac68 CM |
65 | /* |
66 | * path release drops references on the extent buffers in the path | |
67 | * and it drops any locks held by this path | |
68 | * | |
69 | * It is safe to call this on paths that no locks or extent buffers held. | |
70 | */ | |
b3b4aa74 | 71 | noinline void btrfs_release_path(struct btrfs_path *p) |
eb60ceac CM |
72 | { |
73 | int i; | |
a2135011 | 74 | |
234b63a0 | 75 | for (i = 0; i < BTRFS_MAX_LEVEL; i++) { |
3f157a2f | 76 | p->slots[i] = 0; |
eb60ceac | 77 | if (!p->nodes[i]) |
925baedd CM |
78 | continue; |
79 | if (p->locks[i]) { | |
bd681513 | 80 | btrfs_tree_unlock_rw(p->nodes[i], p->locks[i]); |
925baedd CM |
81 | p->locks[i] = 0; |
82 | } | |
5f39d397 | 83 | free_extent_buffer(p->nodes[i]); |
3f157a2f | 84 | p->nodes[i] = NULL; |
eb60ceac CM |
85 | } |
86 | } | |
87 | ||
d352ac68 CM |
88 | /* |
89 | * safely gets a reference on the root node of a tree. A lock | |
90 | * is not taken, so a concurrent writer may put a different node | |
91 | * at the root of the tree. See btrfs_lock_root_node for the | |
92 | * looping required. | |
93 | * | |
94 | * The extent buffer returned by this has a reference taken, so | |
95 | * it won't disappear. It may stop being the root of the tree | |
96 | * at any time because there are no locks held. | |
97 | */ | |
925baedd CM |
98 | struct extent_buffer *btrfs_root_node(struct btrfs_root *root) |
99 | { | |
100 | struct extent_buffer *eb; | |
240f62c8 | 101 | |
3083ee2e JB |
102 | while (1) { |
103 | rcu_read_lock(); | |
104 | eb = rcu_dereference(root->node); | |
105 | ||
106 | /* | |
107 | * RCU really hurts here, we could free up the root node because | |
01327610 | 108 | * it was COWed but we may not get the new root node yet so do |
3083ee2e JB |
109 | * the inc_not_zero dance and if it doesn't work then |
110 | * synchronize_rcu and try again. | |
111 | */ | |
112 | if (atomic_inc_not_zero(&eb->refs)) { | |
113 | rcu_read_unlock(); | |
114 | break; | |
115 | } | |
116 | rcu_read_unlock(); | |
117 | synchronize_rcu(); | |
118 | } | |
925baedd CM |
119 | return eb; |
120 | } | |
121 | ||
d352ac68 CM |
122 | /* loop around taking references on and locking the root node of the |
123 | * tree until you end up with a lock on the root. A locked buffer | |
124 | * is returned, with a reference held. | |
125 | */ | |
925baedd CM |
126 | struct extent_buffer *btrfs_lock_root_node(struct btrfs_root *root) |
127 | { | |
128 | struct extent_buffer *eb; | |
129 | ||
d397712b | 130 | while (1) { |
925baedd CM |
131 | eb = btrfs_root_node(root); |
132 | btrfs_tree_lock(eb); | |
240f62c8 | 133 | if (eb == root->node) |
925baedd | 134 | break; |
925baedd CM |
135 | btrfs_tree_unlock(eb); |
136 | free_extent_buffer(eb); | |
137 | } | |
138 | return eb; | |
139 | } | |
140 | ||
bd681513 CM |
141 | /* loop around taking references on and locking the root node of the |
142 | * tree until you end up with a lock on the root. A locked buffer | |
143 | * is returned, with a reference held. | |
144 | */ | |
84f7d8e6 | 145 | struct extent_buffer *btrfs_read_lock_root_node(struct btrfs_root *root) |
bd681513 CM |
146 | { |
147 | struct extent_buffer *eb; | |
148 | ||
149 | while (1) { | |
150 | eb = btrfs_root_node(root); | |
151 | btrfs_tree_read_lock(eb); | |
152 | if (eb == root->node) | |
153 | break; | |
154 | btrfs_tree_read_unlock(eb); | |
155 | free_extent_buffer(eb); | |
156 | } | |
157 | return eb; | |
158 | } | |
159 | ||
d352ac68 CM |
160 | /* cowonly root (everything not a reference counted cow subvolume), just get |
161 | * put onto a simple dirty list. transaction.c walks this to make sure they | |
162 | * get properly updated on disk. | |
163 | */ | |
0b86a832 CM |
164 | static void add_root_to_dirty_list(struct btrfs_root *root) |
165 | { | |
0b246afa JM |
166 | struct btrfs_fs_info *fs_info = root->fs_info; |
167 | ||
e7070be1 JB |
168 | if (test_bit(BTRFS_ROOT_DIRTY, &root->state) || |
169 | !test_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state)) | |
170 | return; | |
171 | ||
0b246afa | 172 | spin_lock(&fs_info->trans_lock); |
e7070be1 JB |
173 | if (!test_and_set_bit(BTRFS_ROOT_DIRTY, &root->state)) { |
174 | /* Want the extent tree to be the last on the list */ | |
4fd786e6 | 175 | if (root->root_key.objectid == BTRFS_EXTENT_TREE_OBJECTID) |
e7070be1 | 176 | list_move_tail(&root->dirty_list, |
0b246afa | 177 | &fs_info->dirty_cowonly_roots); |
e7070be1 JB |
178 | else |
179 | list_move(&root->dirty_list, | |
0b246afa | 180 | &fs_info->dirty_cowonly_roots); |
0b86a832 | 181 | } |
0b246afa | 182 | spin_unlock(&fs_info->trans_lock); |
0b86a832 CM |
183 | } |
184 | ||
d352ac68 CM |
185 | /* |
186 | * used by snapshot creation to make a copy of a root for a tree with | |
187 | * a given objectid. The buffer with the new root node is returned in | |
188 | * cow_ret, and this func returns zero on success or a negative error code. | |
189 | */ | |
be20aa9d CM |
190 | int btrfs_copy_root(struct btrfs_trans_handle *trans, |
191 | struct btrfs_root *root, | |
192 | struct extent_buffer *buf, | |
193 | struct extent_buffer **cow_ret, u64 new_root_objectid) | |
194 | { | |
0b246afa | 195 | struct btrfs_fs_info *fs_info = root->fs_info; |
be20aa9d | 196 | struct extent_buffer *cow; |
be20aa9d CM |
197 | int ret = 0; |
198 | int level; | |
5d4f98a2 | 199 | struct btrfs_disk_key disk_key; |
be20aa9d | 200 | |
27cdeb70 | 201 | WARN_ON(test_bit(BTRFS_ROOT_REF_COWS, &root->state) && |
0b246afa | 202 | trans->transid != fs_info->running_transaction->transid); |
27cdeb70 MX |
203 | WARN_ON(test_bit(BTRFS_ROOT_REF_COWS, &root->state) && |
204 | trans->transid != root->last_trans); | |
be20aa9d CM |
205 | |
206 | level = btrfs_header_level(buf); | |
5d4f98a2 YZ |
207 | if (level == 0) |
208 | btrfs_item_key(buf, &disk_key, 0); | |
209 | else | |
210 | btrfs_node_key(buf, &disk_key, 0); | |
31840ae1 | 211 | |
4d75f8a9 DS |
212 | cow = btrfs_alloc_tree_block(trans, root, 0, new_root_objectid, |
213 | &disk_key, level, buf->start, 0); | |
5d4f98a2 | 214 | if (IS_ERR(cow)) |
be20aa9d CM |
215 | return PTR_ERR(cow); |
216 | ||
58e8012c | 217 | copy_extent_buffer_full(cow, buf); |
be20aa9d CM |
218 | btrfs_set_header_bytenr(cow, cow->start); |
219 | btrfs_set_header_generation(cow, trans->transid); | |
5d4f98a2 YZ |
220 | btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV); |
221 | btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN | | |
222 | BTRFS_HEADER_FLAG_RELOC); | |
223 | if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID) | |
224 | btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC); | |
225 | else | |
226 | btrfs_set_header_owner(cow, new_root_objectid); | |
be20aa9d | 227 | |
de37aa51 | 228 | write_extent_buffer_fsid(cow, fs_info->fs_devices->metadata_uuid); |
2b82032c | 229 | |
be20aa9d | 230 | WARN_ON(btrfs_header_generation(buf) > trans->transid); |
5d4f98a2 | 231 | if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID) |
e339a6b0 | 232 | ret = btrfs_inc_ref(trans, root, cow, 1); |
5d4f98a2 | 233 | else |
e339a6b0 | 234 | ret = btrfs_inc_ref(trans, root, cow, 0); |
4aec2b52 | 235 | |
be20aa9d CM |
236 | if (ret) |
237 | return ret; | |
238 | ||
239 | btrfs_mark_buffer_dirty(cow); | |
240 | *cow_ret = cow; | |
241 | return 0; | |
242 | } | |
243 | ||
bd989ba3 JS |
244 | enum mod_log_op { |
245 | MOD_LOG_KEY_REPLACE, | |
246 | MOD_LOG_KEY_ADD, | |
247 | MOD_LOG_KEY_REMOVE, | |
248 | MOD_LOG_KEY_REMOVE_WHILE_FREEING, | |
249 | MOD_LOG_KEY_REMOVE_WHILE_MOVING, | |
250 | MOD_LOG_MOVE_KEYS, | |
251 | MOD_LOG_ROOT_REPLACE, | |
252 | }; | |
253 | ||
bd989ba3 JS |
254 | struct tree_mod_root { |
255 | u64 logical; | |
256 | u8 level; | |
257 | }; | |
258 | ||
259 | struct tree_mod_elem { | |
260 | struct rb_node node; | |
298cfd36 | 261 | u64 logical; |
097b8a7c | 262 | u64 seq; |
bd989ba3 JS |
263 | enum mod_log_op op; |
264 | ||
265 | /* this is used for MOD_LOG_KEY_* and MOD_LOG_MOVE_KEYS operations */ | |
266 | int slot; | |
267 | ||
268 | /* this is used for MOD_LOG_KEY* and MOD_LOG_ROOT_REPLACE */ | |
269 | u64 generation; | |
270 | ||
271 | /* those are used for op == MOD_LOG_KEY_{REPLACE,REMOVE} */ | |
272 | struct btrfs_disk_key key; | |
273 | u64 blockptr; | |
274 | ||
275 | /* this is used for op == MOD_LOG_MOVE_KEYS */ | |
b6dfa35b DS |
276 | struct { |
277 | int dst_slot; | |
278 | int nr_items; | |
279 | } move; | |
bd989ba3 JS |
280 | |
281 | /* this is used for op == MOD_LOG_ROOT_REPLACE */ | |
282 | struct tree_mod_root old_root; | |
283 | }; | |
284 | ||
fc36ed7e | 285 | /* |
fcebe456 | 286 | * Pull a new tree mod seq number for our operation. |
fc36ed7e | 287 | */ |
fcebe456 | 288 | static inline u64 btrfs_inc_tree_mod_seq(struct btrfs_fs_info *fs_info) |
fc36ed7e JS |
289 | { |
290 | return atomic64_inc_return(&fs_info->tree_mod_seq); | |
291 | } | |
292 | ||
097b8a7c JS |
293 | /* |
294 | * This adds a new blocker to the tree mod log's blocker list if the @elem | |
295 | * passed does not already have a sequence number set. So when a caller expects | |
296 | * to record tree modifications, it should ensure to set elem->seq to zero | |
297 | * before calling btrfs_get_tree_mod_seq. | |
298 | * Returns a fresh, unused tree log modification sequence number, even if no new | |
299 | * blocker was added. | |
300 | */ | |
301 | u64 btrfs_get_tree_mod_seq(struct btrfs_fs_info *fs_info, | |
302 | struct seq_list *elem) | |
bd989ba3 | 303 | { |
b1a09f1e | 304 | write_lock(&fs_info->tree_mod_log_lock); |
bd989ba3 | 305 | spin_lock(&fs_info->tree_mod_seq_lock); |
097b8a7c | 306 | if (!elem->seq) { |
fcebe456 | 307 | elem->seq = btrfs_inc_tree_mod_seq(fs_info); |
097b8a7c JS |
308 | list_add_tail(&elem->list, &fs_info->tree_mod_seq_list); |
309 | } | |
bd989ba3 | 310 | spin_unlock(&fs_info->tree_mod_seq_lock); |
b1a09f1e | 311 | write_unlock(&fs_info->tree_mod_log_lock); |
097b8a7c | 312 | |
fcebe456 | 313 | return elem->seq; |
bd989ba3 JS |
314 | } |
315 | ||
316 | void btrfs_put_tree_mod_seq(struct btrfs_fs_info *fs_info, | |
317 | struct seq_list *elem) | |
318 | { | |
319 | struct rb_root *tm_root; | |
320 | struct rb_node *node; | |
321 | struct rb_node *next; | |
322 | struct seq_list *cur_elem; | |
323 | struct tree_mod_elem *tm; | |
324 | u64 min_seq = (u64)-1; | |
325 | u64 seq_putting = elem->seq; | |
326 | ||
327 | if (!seq_putting) | |
328 | return; | |
329 | ||
bd989ba3 JS |
330 | spin_lock(&fs_info->tree_mod_seq_lock); |
331 | list_del(&elem->list); | |
097b8a7c | 332 | elem->seq = 0; |
bd989ba3 JS |
333 | |
334 | list_for_each_entry(cur_elem, &fs_info->tree_mod_seq_list, list) { | |
097b8a7c | 335 | if (cur_elem->seq < min_seq) { |
bd989ba3 JS |
336 | if (seq_putting > cur_elem->seq) { |
337 | /* | |
338 | * blocker with lower sequence number exists, we | |
339 | * cannot remove anything from the log | |
340 | */ | |
097b8a7c JS |
341 | spin_unlock(&fs_info->tree_mod_seq_lock); |
342 | return; | |
bd989ba3 JS |
343 | } |
344 | min_seq = cur_elem->seq; | |
345 | } | |
346 | } | |
097b8a7c JS |
347 | spin_unlock(&fs_info->tree_mod_seq_lock); |
348 | ||
bd989ba3 JS |
349 | /* |
350 | * anything that's lower than the lowest existing (read: blocked) | |
351 | * sequence number can be removed from the tree. | |
352 | */ | |
b1a09f1e | 353 | write_lock(&fs_info->tree_mod_log_lock); |
bd989ba3 JS |
354 | tm_root = &fs_info->tree_mod_log; |
355 | for (node = rb_first(tm_root); node; node = next) { | |
356 | next = rb_next(node); | |
6b4df8b6 | 357 | tm = rb_entry(node, struct tree_mod_elem, node); |
097b8a7c | 358 | if (tm->seq > min_seq) |
bd989ba3 JS |
359 | continue; |
360 | rb_erase(node, tm_root); | |
bd989ba3 JS |
361 | kfree(tm); |
362 | } | |
b1a09f1e | 363 | write_unlock(&fs_info->tree_mod_log_lock); |
bd989ba3 JS |
364 | } |
365 | ||
366 | /* | |
367 | * key order of the log: | |
298cfd36 | 368 | * node/leaf start address -> sequence |
bd989ba3 | 369 | * |
298cfd36 CR |
370 | * The 'start address' is the logical address of the *new* root node |
371 | * for root replace operations, or the logical address of the affected | |
372 | * block for all other operations. | |
5de865ee | 373 | * |
b1a09f1e | 374 | * Note: must be called with write lock for fs_info::tree_mod_log_lock. |
bd989ba3 JS |
375 | */ |
376 | static noinline int | |
377 | __tree_mod_log_insert(struct btrfs_fs_info *fs_info, struct tree_mod_elem *tm) | |
378 | { | |
379 | struct rb_root *tm_root; | |
380 | struct rb_node **new; | |
381 | struct rb_node *parent = NULL; | |
382 | struct tree_mod_elem *cur; | |
c8cc6341 | 383 | |
fcebe456 | 384 | tm->seq = btrfs_inc_tree_mod_seq(fs_info); |
bd989ba3 | 385 | |
bd989ba3 JS |
386 | tm_root = &fs_info->tree_mod_log; |
387 | new = &tm_root->rb_node; | |
388 | while (*new) { | |
6b4df8b6 | 389 | cur = rb_entry(*new, struct tree_mod_elem, node); |
bd989ba3 | 390 | parent = *new; |
298cfd36 | 391 | if (cur->logical < tm->logical) |
bd989ba3 | 392 | new = &((*new)->rb_left); |
298cfd36 | 393 | else if (cur->logical > tm->logical) |
bd989ba3 | 394 | new = &((*new)->rb_right); |
097b8a7c | 395 | else if (cur->seq < tm->seq) |
bd989ba3 | 396 | new = &((*new)->rb_left); |
097b8a7c | 397 | else if (cur->seq > tm->seq) |
bd989ba3 | 398 | new = &((*new)->rb_right); |
5de865ee FDBM |
399 | else |
400 | return -EEXIST; | |
bd989ba3 JS |
401 | } |
402 | ||
403 | rb_link_node(&tm->node, parent, new); | |
404 | rb_insert_color(&tm->node, tm_root); | |
5de865ee | 405 | return 0; |
bd989ba3 JS |
406 | } |
407 | ||
097b8a7c JS |
408 | /* |
409 | * Determines if logging can be omitted. Returns 1 if it can. Otherwise, it | |
410 | * returns zero with the tree_mod_log_lock acquired. The caller must hold | |
411 | * this until all tree mod log insertions are recorded in the rb tree and then | |
b1a09f1e | 412 | * write unlock fs_info::tree_mod_log_lock. |
097b8a7c | 413 | */ |
e9b7fd4d JS |
414 | static inline int tree_mod_dont_log(struct btrfs_fs_info *fs_info, |
415 | struct extent_buffer *eb) { | |
416 | smp_mb(); | |
417 | if (list_empty(&(fs_info)->tree_mod_seq_list)) | |
418 | return 1; | |
097b8a7c JS |
419 | if (eb && btrfs_header_level(eb) == 0) |
420 | return 1; | |
5de865ee | 421 | |
b1a09f1e | 422 | write_lock(&fs_info->tree_mod_log_lock); |
5de865ee | 423 | if (list_empty(&(fs_info)->tree_mod_seq_list)) { |
b1a09f1e | 424 | write_unlock(&fs_info->tree_mod_log_lock); |
5de865ee FDBM |
425 | return 1; |
426 | } | |
427 | ||
e9b7fd4d JS |
428 | return 0; |
429 | } | |
430 | ||
5de865ee FDBM |
431 | /* Similar to tree_mod_dont_log, but doesn't acquire any locks. */ |
432 | static inline int tree_mod_need_log(const struct btrfs_fs_info *fs_info, | |
433 | struct extent_buffer *eb) | |
434 | { | |
435 | smp_mb(); | |
436 | if (list_empty(&(fs_info)->tree_mod_seq_list)) | |
437 | return 0; | |
438 | if (eb && btrfs_header_level(eb) == 0) | |
439 | return 0; | |
440 | ||
441 | return 1; | |
442 | } | |
443 | ||
444 | static struct tree_mod_elem * | |
445 | alloc_tree_mod_elem(struct extent_buffer *eb, int slot, | |
446 | enum mod_log_op op, gfp_t flags) | |
bd989ba3 | 447 | { |
097b8a7c | 448 | struct tree_mod_elem *tm; |
bd989ba3 | 449 | |
c8cc6341 JB |
450 | tm = kzalloc(sizeof(*tm), flags); |
451 | if (!tm) | |
5de865ee | 452 | return NULL; |
bd989ba3 | 453 | |
298cfd36 | 454 | tm->logical = eb->start; |
bd989ba3 JS |
455 | if (op != MOD_LOG_KEY_ADD) { |
456 | btrfs_node_key(eb, &tm->key, slot); | |
457 | tm->blockptr = btrfs_node_blockptr(eb, slot); | |
458 | } | |
459 | tm->op = op; | |
460 | tm->slot = slot; | |
461 | tm->generation = btrfs_node_ptr_generation(eb, slot); | |
5de865ee | 462 | RB_CLEAR_NODE(&tm->node); |
bd989ba3 | 463 | |
5de865ee | 464 | return tm; |
097b8a7c JS |
465 | } |
466 | ||
e09c2efe DS |
467 | static noinline int tree_mod_log_insert_key(struct extent_buffer *eb, int slot, |
468 | enum mod_log_op op, gfp_t flags) | |
097b8a7c | 469 | { |
5de865ee FDBM |
470 | struct tree_mod_elem *tm; |
471 | int ret; | |
472 | ||
e09c2efe | 473 | if (!tree_mod_need_log(eb->fs_info, eb)) |
5de865ee FDBM |
474 | return 0; |
475 | ||
476 | tm = alloc_tree_mod_elem(eb, slot, op, flags); | |
477 | if (!tm) | |
478 | return -ENOMEM; | |
479 | ||
e09c2efe | 480 | if (tree_mod_dont_log(eb->fs_info, eb)) { |
5de865ee | 481 | kfree(tm); |
097b8a7c | 482 | return 0; |
5de865ee FDBM |
483 | } |
484 | ||
e09c2efe | 485 | ret = __tree_mod_log_insert(eb->fs_info, tm); |
b1a09f1e | 486 | write_unlock(&eb->fs_info->tree_mod_log_lock); |
5de865ee FDBM |
487 | if (ret) |
488 | kfree(tm); | |
097b8a7c | 489 | |
5de865ee | 490 | return ret; |
097b8a7c JS |
491 | } |
492 | ||
6074d45f DS |
493 | static noinline int tree_mod_log_insert_move(struct extent_buffer *eb, |
494 | int dst_slot, int src_slot, int nr_items) | |
bd989ba3 | 495 | { |
5de865ee FDBM |
496 | struct tree_mod_elem *tm = NULL; |
497 | struct tree_mod_elem **tm_list = NULL; | |
498 | int ret = 0; | |
bd989ba3 | 499 | int i; |
5de865ee | 500 | int locked = 0; |
bd989ba3 | 501 | |
6074d45f | 502 | if (!tree_mod_need_log(eb->fs_info, eb)) |
f395694c | 503 | return 0; |
bd989ba3 | 504 | |
176ef8f5 | 505 | tm_list = kcalloc(nr_items, sizeof(struct tree_mod_elem *), GFP_NOFS); |
5de865ee FDBM |
506 | if (!tm_list) |
507 | return -ENOMEM; | |
508 | ||
176ef8f5 | 509 | tm = kzalloc(sizeof(*tm), GFP_NOFS); |
5de865ee FDBM |
510 | if (!tm) { |
511 | ret = -ENOMEM; | |
512 | goto free_tms; | |
513 | } | |
514 | ||
298cfd36 | 515 | tm->logical = eb->start; |
5de865ee FDBM |
516 | tm->slot = src_slot; |
517 | tm->move.dst_slot = dst_slot; | |
518 | tm->move.nr_items = nr_items; | |
519 | tm->op = MOD_LOG_MOVE_KEYS; | |
520 | ||
521 | for (i = 0; i + dst_slot < src_slot && i < nr_items; i++) { | |
522 | tm_list[i] = alloc_tree_mod_elem(eb, i + dst_slot, | |
176ef8f5 | 523 | MOD_LOG_KEY_REMOVE_WHILE_MOVING, GFP_NOFS); |
5de865ee FDBM |
524 | if (!tm_list[i]) { |
525 | ret = -ENOMEM; | |
526 | goto free_tms; | |
527 | } | |
528 | } | |
529 | ||
6074d45f | 530 | if (tree_mod_dont_log(eb->fs_info, eb)) |
5de865ee FDBM |
531 | goto free_tms; |
532 | locked = 1; | |
533 | ||
01763a2e JS |
534 | /* |
535 | * When we override something during the move, we log these removals. | |
536 | * This can only happen when we move towards the beginning of the | |
537 | * buffer, i.e. dst_slot < src_slot. | |
538 | */ | |
bd989ba3 | 539 | for (i = 0; i + dst_slot < src_slot && i < nr_items; i++) { |
6074d45f | 540 | ret = __tree_mod_log_insert(eb->fs_info, tm_list[i]); |
5de865ee FDBM |
541 | if (ret) |
542 | goto free_tms; | |
bd989ba3 JS |
543 | } |
544 | ||
6074d45f | 545 | ret = __tree_mod_log_insert(eb->fs_info, tm); |
5de865ee FDBM |
546 | if (ret) |
547 | goto free_tms; | |
b1a09f1e | 548 | write_unlock(&eb->fs_info->tree_mod_log_lock); |
5de865ee | 549 | kfree(tm_list); |
f395694c | 550 | |
5de865ee FDBM |
551 | return 0; |
552 | free_tms: | |
553 | for (i = 0; i < nr_items; i++) { | |
554 | if (tm_list[i] && !RB_EMPTY_NODE(&tm_list[i]->node)) | |
6074d45f | 555 | rb_erase(&tm_list[i]->node, &eb->fs_info->tree_mod_log); |
5de865ee FDBM |
556 | kfree(tm_list[i]); |
557 | } | |
558 | if (locked) | |
b1a09f1e | 559 | write_unlock(&eb->fs_info->tree_mod_log_lock); |
5de865ee FDBM |
560 | kfree(tm_list); |
561 | kfree(tm); | |
bd989ba3 | 562 | |
5de865ee | 563 | return ret; |
bd989ba3 JS |
564 | } |
565 | ||
5de865ee FDBM |
566 | static inline int |
567 | __tree_mod_log_free_eb(struct btrfs_fs_info *fs_info, | |
568 | struct tree_mod_elem **tm_list, | |
569 | int nritems) | |
097b8a7c | 570 | { |
5de865ee | 571 | int i, j; |
097b8a7c JS |
572 | int ret; |
573 | ||
097b8a7c | 574 | for (i = nritems - 1; i >= 0; i--) { |
5de865ee FDBM |
575 | ret = __tree_mod_log_insert(fs_info, tm_list[i]); |
576 | if (ret) { | |
577 | for (j = nritems - 1; j > i; j--) | |
578 | rb_erase(&tm_list[j]->node, | |
579 | &fs_info->tree_mod_log); | |
580 | return ret; | |
581 | } | |
097b8a7c | 582 | } |
5de865ee FDBM |
583 | |
584 | return 0; | |
097b8a7c JS |
585 | } |
586 | ||
95b757c1 DS |
587 | static noinline int tree_mod_log_insert_root(struct extent_buffer *old_root, |
588 | struct extent_buffer *new_root, int log_removal) | |
bd989ba3 | 589 | { |
95b757c1 | 590 | struct btrfs_fs_info *fs_info = old_root->fs_info; |
5de865ee FDBM |
591 | struct tree_mod_elem *tm = NULL; |
592 | struct tree_mod_elem **tm_list = NULL; | |
593 | int nritems = 0; | |
594 | int ret = 0; | |
595 | int i; | |
bd989ba3 | 596 | |
5de865ee | 597 | if (!tree_mod_need_log(fs_info, NULL)) |
097b8a7c JS |
598 | return 0; |
599 | ||
5de865ee FDBM |
600 | if (log_removal && btrfs_header_level(old_root) > 0) { |
601 | nritems = btrfs_header_nritems(old_root); | |
31e818fe | 602 | tm_list = kcalloc(nritems, sizeof(struct tree_mod_elem *), |
bcc8e07f | 603 | GFP_NOFS); |
5de865ee FDBM |
604 | if (!tm_list) { |
605 | ret = -ENOMEM; | |
606 | goto free_tms; | |
607 | } | |
608 | for (i = 0; i < nritems; i++) { | |
609 | tm_list[i] = alloc_tree_mod_elem(old_root, i, | |
bcc8e07f | 610 | MOD_LOG_KEY_REMOVE_WHILE_FREEING, GFP_NOFS); |
5de865ee FDBM |
611 | if (!tm_list[i]) { |
612 | ret = -ENOMEM; | |
613 | goto free_tms; | |
614 | } | |
615 | } | |
616 | } | |
d9abbf1c | 617 | |
bcc8e07f | 618 | tm = kzalloc(sizeof(*tm), GFP_NOFS); |
5de865ee FDBM |
619 | if (!tm) { |
620 | ret = -ENOMEM; | |
621 | goto free_tms; | |
622 | } | |
bd989ba3 | 623 | |
298cfd36 | 624 | tm->logical = new_root->start; |
bd989ba3 JS |
625 | tm->old_root.logical = old_root->start; |
626 | tm->old_root.level = btrfs_header_level(old_root); | |
627 | tm->generation = btrfs_header_generation(old_root); | |
628 | tm->op = MOD_LOG_ROOT_REPLACE; | |
629 | ||
5de865ee FDBM |
630 | if (tree_mod_dont_log(fs_info, NULL)) |
631 | goto free_tms; | |
632 | ||
633 | if (tm_list) | |
634 | ret = __tree_mod_log_free_eb(fs_info, tm_list, nritems); | |
635 | if (!ret) | |
636 | ret = __tree_mod_log_insert(fs_info, tm); | |
637 | ||
b1a09f1e | 638 | write_unlock(&fs_info->tree_mod_log_lock); |
5de865ee FDBM |
639 | if (ret) |
640 | goto free_tms; | |
641 | kfree(tm_list); | |
642 | ||
643 | return ret; | |
644 | ||
645 | free_tms: | |
646 | if (tm_list) { | |
647 | for (i = 0; i < nritems; i++) | |
648 | kfree(tm_list[i]); | |
649 | kfree(tm_list); | |
650 | } | |
651 | kfree(tm); | |
652 | ||
653 | return ret; | |
bd989ba3 JS |
654 | } |
655 | ||
656 | static struct tree_mod_elem * | |
657 | __tree_mod_log_search(struct btrfs_fs_info *fs_info, u64 start, u64 min_seq, | |
658 | int smallest) | |
659 | { | |
660 | struct rb_root *tm_root; | |
661 | struct rb_node *node; | |
662 | struct tree_mod_elem *cur = NULL; | |
663 | struct tree_mod_elem *found = NULL; | |
bd989ba3 | 664 | |
b1a09f1e | 665 | read_lock(&fs_info->tree_mod_log_lock); |
bd989ba3 JS |
666 | tm_root = &fs_info->tree_mod_log; |
667 | node = tm_root->rb_node; | |
668 | while (node) { | |
6b4df8b6 | 669 | cur = rb_entry(node, struct tree_mod_elem, node); |
298cfd36 | 670 | if (cur->logical < start) { |
bd989ba3 | 671 | node = node->rb_left; |
298cfd36 | 672 | } else if (cur->logical > start) { |
bd989ba3 | 673 | node = node->rb_right; |
097b8a7c | 674 | } else if (cur->seq < min_seq) { |
bd989ba3 JS |
675 | node = node->rb_left; |
676 | } else if (!smallest) { | |
677 | /* we want the node with the highest seq */ | |
678 | if (found) | |
097b8a7c | 679 | BUG_ON(found->seq > cur->seq); |
bd989ba3 JS |
680 | found = cur; |
681 | node = node->rb_left; | |
097b8a7c | 682 | } else if (cur->seq > min_seq) { |
bd989ba3 JS |
683 | /* we want the node with the smallest seq */ |
684 | if (found) | |
097b8a7c | 685 | BUG_ON(found->seq < cur->seq); |
bd989ba3 JS |
686 | found = cur; |
687 | node = node->rb_right; | |
688 | } else { | |
689 | found = cur; | |
690 | break; | |
691 | } | |
692 | } | |
b1a09f1e | 693 | read_unlock(&fs_info->tree_mod_log_lock); |
bd989ba3 JS |
694 | |
695 | return found; | |
696 | } | |
697 | ||
698 | /* | |
699 | * this returns the element from the log with the smallest time sequence | |
700 | * value that's in the log (the oldest log item). any element with a time | |
701 | * sequence lower than min_seq will be ignored. | |
702 | */ | |
703 | static struct tree_mod_elem * | |
704 | tree_mod_log_search_oldest(struct btrfs_fs_info *fs_info, u64 start, | |
705 | u64 min_seq) | |
706 | { | |
707 | return __tree_mod_log_search(fs_info, start, min_seq, 1); | |
708 | } | |
709 | ||
710 | /* | |
711 | * this returns the element from the log with the largest time sequence | |
712 | * value that's in the log (the most recent log item). any element with | |
713 | * a time sequence lower than min_seq will be ignored. | |
714 | */ | |
715 | static struct tree_mod_elem * | |
716 | tree_mod_log_search(struct btrfs_fs_info *fs_info, u64 start, u64 min_seq) | |
717 | { | |
718 | return __tree_mod_log_search(fs_info, start, min_seq, 0); | |
719 | } | |
720 | ||
5de865ee | 721 | static noinline int |
bd989ba3 JS |
722 | tree_mod_log_eb_copy(struct btrfs_fs_info *fs_info, struct extent_buffer *dst, |
723 | struct extent_buffer *src, unsigned long dst_offset, | |
90f8d62e | 724 | unsigned long src_offset, int nr_items) |
bd989ba3 | 725 | { |
5de865ee FDBM |
726 | int ret = 0; |
727 | struct tree_mod_elem **tm_list = NULL; | |
728 | struct tree_mod_elem **tm_list_add, **tm_list_rem; | |
bd989ba3 | 729 | int i; |
5de865ee | 730 | int locked = 0; |
bd989ba3 | 731 | |
5de865ee FDBM |
732 | if (!tree_mod_need_log(fs_info, NULL)) |
733 | return 0; | |
bd989ba3 | 734 | |
c8cc6341 | 735 | if (btrfs_header_level(dst) == 0 && btrfs_header_level(src) == 0) |
5de865ee FDBM |
736 | return 0; |
737 | ||
31e818fe | 738 | tm_list = kcalloc(nr_items * 2, sizeof(struct tree_mod_elem *), |
5de865ee FDBM |
739 | GFP_NOFS); |
740 | if (!tm_list) | |
741 | return -ENOMEM; | |
bd989ba3 | 742 | |
5de865ee FDBM |
743 | tm_list_add = tm_list; |
744 | tm_list_rem = tm_list + nr_items; | |
bd989ba3 | 745 | for (i = 0; i < nr_items; i++) { |
5de865ee FDBM |
746 | tm_list_rem[i] = alloc_tree_mod_elem(src, i + src_offset, |
747 | MOD_LOG_KEY_REMOVE, GFP_NOFS); | |
748 | if (!tm_list_rem[i]) { | |
749 | ret = -ENOMEM; | |
750 | goto free_tms; | |
751 | } | |
752 | ||
753 | tm_list_add[i] = alloc_tree_mod_elem(dst, i + dst_offset, | |
754 | MOD_LOG_KEY_ADD, GFP_NOFS); | |
755 | if (!tm_list_add[i]) { | |
756 | ret = -ENOMEM; | |
757 | goto free_tms; | |
758 | } | |
759 | } | |
760 | ||
761 | if (tree_mod_dont_log(fs_info, NULL)) | |
762 | goto free_tms; | |
763 | locked = 1; | |
764 | ||
765 | for (i = 0; i < nr_items; i++) { | |
766 | ret = __tree_mod_log_insert(fs_info, tm_list_rem[i]); | |
767 | if (ret) | |
768 | goto free_tms; | |
769 | ret = __tree_mod_log_insert(fs_info, tm_list_add[i]); | |
770 | if (ret) | |
771 | goto free_tms; | |
bd989ba3 | 772 | } |
5de865ee | 773 | |
b1a09f1e | 774 | write_unlock(&fs_info->tree_mod_log_lock); |
5de865ee FDBM |
775 | kfree(tm_list); |
776 | ||
777 | return 0; | |
778 | ||
779 | free_tms: | |
780 | for (i = 0; i < nr_items * 2; i++) { | |
781 | if (tm_list[i] && !RB_EMPTY_NODE(&tm_list[i]->node)) | |
782 | rb_erase(&tm_list[i]->node, &fs_info->tree_mod_log); | |
783 | kfree(tm_list[i]); | |
784 | } | |
785 | if (locked) | |
b1a09f1e | 786 | write_unlock(&fs_info->tree_mod_log_lock); |
5de865ee FDBM |
787 | kfree(tm_list); |
788 | ||
789 | return ret; | |
bd989ba3 JS |
790 | } |
791 | ||
db7279a2 | 792 | static noinline int tree_mod_log_free_eb(struct extent_buffer *eb) |
bd989ba3 | 793 | { |
5de865ee FDBM |
794 | struct tree_mod_elem **tm_list = NULL; |
795 | int nritems = 0; | |
796 | int i; | |
797 | int ret = 0; | |
798 | ||
799 | if (btrfs_header_level(eb) == 0) | |
800 | return 0; | |
801 | ||
db7279a2 | 802 | if (!tree_mod_need_log(eb->fs_info, NULL)) |
5de865ee FDBM |
803 | return 0; |
804 | ||
805 | nritems = btrfs_header_nritems(eb); | |
31e818fe | 806 | tm_list = kcalloc(nritems, sizeof(struct tree_mod_elem *), GFP_NOFS); |
5de865ee FDBM |
807 | if (!tm_list) |
808 | return -ENOMEM; | |
809 | ||
810 | for (i = 0; i < nritems; i++) { | |
811 | tm_list[i] = alloc_tree_mod_elem(eb, i, | |
812 | MOD_LOG_KEY_REMOVE_WHILE_FREEING, GFP_NOFS); | |
813 | if (!tm_list[i]) { | |
814 | ret = -ENOMEM; | |
815 | goto free_tms; | |
816 | } | |
817 | } | |
818 | ||
db7279a2 | 819 | if (tree_mod_dont_log(eb->fs_info, eb)) |
5de865ee FDBM |
820 | goto free_tms; |
821 | ||
db7279a2 | 822 | ret = __tree_mod_log_free_eb(eb->fs_info, tm_list, nritems); |
b1a09f1e | 823 | write_unlock(&eb->fs_info->tree_mod_log_lock); |
5de865ee FDBM |
824 | if (ret) |
825 | goto free_tms; | |
826 | kfree(tm_list); | |
827 | ||
828 | return 0; | |
829 | ||
830 | free_tms: | |
831 | for (i = 0; i < nritems; i++) | |
832 | kfree(tm_list[i]); | |
833 | kfree(tm_list); | |
834 | ||
835 | return ret; | |
bd989ba3 JS |
836 | } |
837 | ||
5d4f98a2 YZ |
838 | /* |
839 | * check if the tree block can be shared by multiple trees | |
840 | */ | |
841 | int btrfs_block_can_be_shared(struct btrfs_root *root, | |
842 | struct extent_buffer *buf) | |
843 | { | |
844 | /* | |
01327610 | 845 | * Tree blocks not in reference counted trees and tree roots |
5d4f98a2 YZ |
846 | * are never shared. If a block was allocated after the last |
847 | * snapshot and the block was not allocated by tree relocation, | |
848 | * we know the block is not shared. | |
849 | */ | |
27cdeb70 | 850 | if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) && |
5d4f98a2 YZ |
851 | buf != root->node && buf != root->commit_root && |
852 | (btrfs_header_generation(buf) <= | |
853 | btrfs_root_last_snapshot(&root->root_item) || | |
854 | btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC))) | |
855 | return 1; | |
a79865c6 | 856 | |
5d4f98a2 YZ |
857 | return 0; |
858 | } | |
859 | ||
860 | static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans, | |
861 | struct btrfs_root *root, | |
862 | struct extent_buffer *buf, | |
f0486c68 YZ |
863 | struct extent_buffer *cow, |
864 | int *last_ref) | |
5d4f98a2 | 865 | { |
0b246afa | 866 | struct btrfs_fs_info *fs_info = root->fs_info; |
5d4f98a2 YZ |
867 | u64 refs; |
868 | u64 owner; | |
869 | u64 flags; | |
870 | u64 new_flags = 0; | |
871 | int ret; | |
872 | ||
873 | /* | |
874 | * Backrefs update rules: | |
875 | * | |
876 | * Always use full backrefs for extent pointers in tree block | |
877 | * allocated by tree relocation. | |
878 | * | |
879 | * If a shared tree block is no longer referenced by its owner | |
880 | * tree (btrfs_header_owner(buf) == root->root_key.objectid), | |
881 | * use full backrefs for extent pointers in tree block. | |
882 | * | |
883 | * If a tree block is been relocating | |
884 | * (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID), | |
885 | * use full backrefs for extent pointers in tree block. | |
886 | * The reason for this is some operations (such as drop tree) | |
887 | * are only allowed for blocks use full backrefs. | |
888 | */ | |
889 | ||
890 | if (btrfs_block_can_be_shared(root, buf)) { | |
2ff7e61e | 891 | ret = btrfs_lookup_extent_info(trans, fs_info, buf->start, |
3173a18f JB |
892 | btrfs_header_level(buf), 1, |
893 | &refs, &flags); | |
be1a5564 MF |
894 | if (ret) |
895 | return ret; | |
e5df9573 MF |
896 | if (refs == 0) { |
897 | ret = -EROFS; | |
0b246afa | 898 | btrfs_handle_fs_error(fs_info, ret, NULL); |
e5df9573 MF |
899 | return ret; |
900 | } | |
5d4f98a2 YZ |
901 | } else { |
902 | refs = 1; | |
903 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID || | |
904 | btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) | |
905 | flags = BTRFS_BLOCK_FLAG_FULL_BACKREF; | |
906 | else | |
907 | flags = 0; | |
908 | } | |
909 | ||
910 | owner = btrfs_header_owner(buf); | |
911 | BUG_ON(owner == BTRFS_TREE_RELOC_OBJECTID && | |
912 | !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)); | |
913 | ||
914 | if (refs > 1) { | |
915 | if ((owner == root->root_key.objectid || | |
916 | root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) && | |
917 | !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)) { | |
e339a6b0 | 918 | ret = btrfs_inc_ref(trans, root, buf, 1); |
692826b2 JM |
919 | if (ret) |
920 | return ret; | |
5d4f98a2 YZ |
921 | |
922 | if (root->root_key.objectid == | |
923 | BTRFS_TREE_RELOC_OBJECTID) { | |
e339a6b0 | 924 | ret = btrfs_dec_ref(trans, root, buf, 0); |
692826b2 JM |
925 | if (ret) |
926 | return ret; | |
e339a6b0 | 927 | ret = btrfs_inc_ref(trans, root, cow, 1); |
692826b2 JM |
928 | if (ret) |
929 | return ret; | |
5d4f98a2 YZ |
930 | } |
931 | new_flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF; | |
932 | } else { | |
933 | ||
934 | if (root->root_key.objectid == | |
935 | BTRFS_TREE_RELOC_OBJECTID) | |
e339a6b0 | 936 | ret = btrfs_inc_ref(trans, root, cow, 1); |
5d4f98a2 | 937 | else |
e339a6b0 | 938 | ret = btrfs_inc_ref(trans, root, cow, 0); |
692826b2 JM |
939 | if (ret) |
940 | return ret; | |
5d4f98a2 YZ |
941 | } |
942 | if (new_flags != 0) { | |
b1c79e09 JB |
943 | int level = btrfs_header_level(buf); |
944 | ||
2ff7e61e | 945 | ret = btrfs_set_disk_extent_flags(trans, fs_info, |
5d4f98a2 YZ |
946 | buf->start, |
947 | buf->len, | |
b1c79e09 | 948 | new_flags, level, 0); |
be1a5564 MF |
949 | if (ret) |
950 | return ret; | |
5d4f98a2 YZ |
951 | } |
952 | } else { | |
953 | if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF) { | |
954 | if (root->root_key.objectid == | |
955 | BTRFS_TREE_RELOC_OBJECTID) | |
e339a6b0 | 956 | ret = btrfs_inc_ref(trans, root, cow, 1); |
5d4f98a2 | 957 | else |
e339a6b0 | 958 | ret = btrfs_inc_ref(trans, root, cow, 0); |
692826b2 JM |
959 | if (ret) |
960 | return ret; | |
e339a6b0 | 961 | ret = btrfs_dec_ref(trans, root, buf, 1); |
692826b2 JM |
962 | if (ret) |
963 | return ret; | |
5d4f98a2 | 964 | } |
7c302b49 | 965 | clean_tree_block(fs_info, buf); |
f0486c68 | 966 | *last_ref = 1; |
5d4f98a2 YZ |
967 | } |
968 | return 0; | |
969 | } | |
970 | ||
d352ac68 | 971 | /* |
d397712b CM |
972 | * does the dirty work in cow of a single block. The parent block (if |
973 | * supplied) is updated to point to the new cow copy. The new buffer is marked | |
974 | * dirty and returned locked. If you modify the block it needs to be marked | |
975 | * dirty again. | |
d352ac68 CM |
976 | * |
977 | * search_start -- an allocation hint for the new block | |
978 | * | |
d397712b CM |
979 | * empty_size -- a hint that you plan on doing more cow. This is the size in |
980 | * bytes the allocator should try to find free next to the block it returns. | |
981 | * This is just a hint and may be ignored by the allocator. | |
d352ac68 | 982 | */ |
d397712b | 983 | static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans, |
5f39d397 CM |
984 | struct btrfs_root *root, |
985 | struct extent_buffer *buf, | |
986 | struct extent_buffer *parent, int parent_slot, | |
987 | struct extent_buffer **cow_ret, | |
9fa8cfe7 | 988 | u64 search_start, u64 empty_size) |
02217ed2 | 989 | { |
0b246afa | 990 | struct btrfs_fs_info *fs_info = root->fs_info; |
5d4f98a2 | 991 | struct btrfs_disk_key disk_key; |
5f39d397 | 992 | struct extent_buffer *cow; |
be1a5564 | 993 | int level, ret; |
f0486c68 | 994 | int last_ref = 0; |
925baedd | 995 | int unlock_orig = 0; |
0f5053eb | 996 | u64 parent_start = 0; |
7bb86316 | 997 | |
925baedd CM |
998 | if (*cow_ret == buf) |
999 | unlock_orig = 1; | |
1000 | ||
b9447ef8 | 1001 | btrfs_assert_tree_locked(buf); |
925baedd | 1002 | |
27cdeb70 | 1003 | WARN_ON(test_bit(BTRFS_ROOT_REF_COWS, &root->state) && |
0b246afa | 1004 | trans->transid != fs_info->running_transaction->transid); |
27cdeb70 MX |
1005 | WARN_ON(test_bit(BTRFS_ROOT_REF_COWS, &root->state) && |
1006 | trans->transid != root->last_trans); | |
5f39d397 | 1007 | |
7bb86316 | 1008 | level = btrfs_header_level(buf); |
31840ae1 | 1009 | |
5d4f98a2 YZ |
1010 | if (level == 0) |
1011 | btrfs_item_key(buf, &disk_key, 0); | |
1012 | else | |
1013 | btrfs_node_key(buf, &disk_key, 0); | |
1014 | ||
0f5053eb GR |
1015 | if ((root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) && parent) |
1016 | parent_start = parent->start; | |
5d4f98a2 | 1017 | |
5ce55557 | 1018 | /* |
a6d8654d FM |
1019 | * If we are COWing a node/leaf from the extent, chunk, device or free |
1020 | * space trees, make sure that we do not finish block group creation of | |
1021 | * pending block groups. We do this to avoid a deadlock. | |
5ce55557 FM |
1022 | * COWing can result in allocation of a new chunk, and flushing pending |
1023 | * block groups (btrfs_create_pending_block_groups()) can be triggered | |
1024 | * when finishing allocation of a new chunk. Creation of a pending block | |
a6d8654d FM |
1025 | * group modifies the extent, chunk, device and free space trees, |
1026 | * therefore we could deadlock with ourselves since we are holding a | |
1027 | * lock on an extent buffer that btrfs_create_pending_block_groups() may | |
1028 | * try to COW later. | |
5ce55557 FM |
1029 | */ |
1030 | if (root == fs_info->extent_root || | |
1031 | root == fs_info->chunk_root || | |
a6d8654d FM |
1032 | root == fs_info->dev_root || |
1033 | root == fs_info->free_space_root) | |
5ce55557 FM |
1034 | trans->can_flush_pending_bgs = false; |
1035 | ||
4d75f8a9 DS |
1036 | cow = btrfs_alloc_tree_block(trans, root, parent_start, |
1037 | root->root_key.objectid, &disk_key, level, | |
1038 | search_start, empty_size); | |
5ce55557 | 1039 | trans->can_flush_pending_bgs = true; |
54aa1f4d CM |
1040 | if (IS_ERR(cow)) |
1041 | return PTR_ERR(cow); | |
6702ed49 | 1042 | |
b4ce94de CM |
1043 | /* cow is set to blocking by btrfs_init_new_buffer */ |
1044 | ||
58e8012c | 1045 | copy_extent_buffer_full(cow, buf); |
db94535d | 1046 | btrfs_set_header_bytenr(cow, cow->start); |
5f39d397 | 1047 | btrfs_set_header_generation(cow, trans->transid); |
5d4f98a2 YZ |
1048 | btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV); |
1049 | btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN | | |
1050 | BTRFS_HEADER_FLAG_RELOC); | |
1051 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) | |
1052 | btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC); | |
1053 | else | |
1054 | btrfs_set_header_owner(cow, root->root_key.objectid); | |
6702ed49 | 1055 | |
de37aa51 | 1056 | write_extent_buffer_fsid(cow, fs_info->fs_devices->metadata_uuid); |
2b82032c | 1057 | |
be1a5564 | 1058 | ret = update_ref_for_cow(trans, root, buf, cow, &last_ref); |
b68dc2a9 | 1059 | if (ret) { |
66642832 | 1060 | btrfs_abort_transaction(trans, ret); |
b68dc2a9 MF |
1061 | return ret; |
1062 | } | |
1a40e23b | 1063 | |
27cdeb70 | 1064 | if (test_bit(BTRFS_ROOT_REF_COWS, &root->state)) { |
83d4cfd4 | 1065 | ret = btrfs_reloc_cow_block(trans, root, buf, cow); |
93314e3b | 1066 | if (ret) { |
66642832 | 1067 | btrfs_abort_transaction(trans, ret); |
83d4cfd4 | 1068 | return ret; |
93314e3b | 1069 | } |
83d4cfd4 | 1070 | } |
3fd0a558 | 1071 | |
02217ed2 | 1072 | if (buf == root->node) { |
925baedd | 1073 | WARN_ON(parent && parent != buf); |
5d4f98a2 YZ |
1074 | if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID || |
1075 | btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) | |
1076 | parent_start = buf->start; | |
925baedd | 1077 | |
5f39d397 | 1078 | extent_buffer_get(cow); |
d9d19a01 DS |
1079 | ret = tree_mod_log_insert_root(root->node, cow, 1); |
1080 | BUG_ON(ret < 0); | |
240f62c8 | 1081 | rcu_assign_pointer(root->node, cow); |
925baedd | 1082 | |
f0486c68 | 1083 | btrfs_free_tree_block(trans, root, buf, parent_start, |
5581a51a | 1084 | last_ref); |
5f39d397 | 1085 | free_extent_buffer(buf); |
0b86a832 | 1086 | add_root_to_dirty_list(root); |
02217ed2 | 1087 | } else { |
5d4f98a2 | 1088 | WARN_ON(trans->transid != btrfs_header_generation(parent)); |
e09c2efe | 1089 | tree_mod_log_insert_key(parent, parent_slot, |
c8cc6341 | 1090 | MOD_LOG_KEY_REPLACE, GFP_NOFS); |
5f39d397 | 1091 | btrfs_set_node_blockptr(parent, parent_slot, |
db94535d | 1092 | cow->start); |
74493f7a CM |
1093 | btrfs_set_node_ptr_generation(parent, parent_slot, |
1094 | trans->transid); | |
d6025579 | 1095 | btrfs_mark_buffer_dirty(parent); |
5de865ee | 1096 | if (last_ref) { |
db7279a2 | 1097 | ret = tree_mod_log_free_eb(buf); |
5de865ee | 1098 | if (ret) { |
66642832 | 1099 | btrfs_abort_transaction(trans, ret); |
5de865ee FDBM |
1100 | return ret; |
1101 | } | |
1102 | } | |
f0486c68 | 1103 | btrfs_free_tree_block(trans, root, buf, parent_start, |
5581a51a | 1104 | last_ref); |
02217ed2 | 1105 | } |
925baedd CM |
1106 | if (unlock_orig) |
1107 | btrfs_tree_unlock(buf); | |
3083ee2e | 1108 | free_extent_buffer_stale(buf); |
ccd467d6 | 1109 | btrfs_mark_buffer_dirty(cow); |
2c90e5d6 | 1110 | *cow_ret = cow; |
02217ed2 CM |
1111 | return 0; |
1112 | } | |
1113 | ||
5d9e75c4 JS |
1114 | /* |
1115 | * returns the logical address of the oldest predecessor of the given root. | |
1116 | * entries older than time_seq are ignored. | |
1117 | */ | |
bcd24dab DS |
1118 | static struct tree_mod_elem *__tree_mod_log_oldest_root( |
1119 | struct extent_buffer *eb_root, u64 time_seq) | |
5d9e75c4 JS |
1120 | { |
1121 | struct tree_mod_elem *tm; | |
1122 | struct tree_mod_elem *found = NULL; | |
30b0463a | 1123 | u64 root_logical = eb_root->start; |
5d9e75c4 JS |
1124 | int looped = 0; |
1125 | ||
1126 | if (!time_seq) | |
35a3621b | 1127 | return NULL; |
5d9e75c4 JS |
1128 | |
1129 | /* | |
298cfd36 CR |
1130 | * the very last operation that's logged for a root is the |
1131 | * replacement operation (if it is replaced at all). this has | |
1132 | * the logical address of the *new* root, making it the very | |
1133 | * first operation that's logged for this root. | |
5d9e75c4 JS |
1134 | */ |
1135 | while (1) { | |
bcd24dab | 1136 | tm = tree_mod_log_search_oldest(eb_root->fs_info, root_logical, |
5d9e75c4 JS |
1137 | time_seq); |
1138 | if (!looped && !tm) | |
35a3621b | 1139 | return NULL; |
5d9e75c4 | 1140 | /* |
28da9fb4 JS |
1141 | * if there are no tree operation for the oldest root, we simply |
1142 | * return it. this should only happen if that (old) root is at | |
1143 | * level 0. | |
5d9e75c4 | 1144 | */ |
28da9fb4 JS |
1145 | if (!tm) |
1146 | break; | |
5d9e75c4 | 1147 | |
28da9fb4 JS |
1148 | /* |
1149 | * if there's an operation that's not a root replacement, we | |
1150 | * found the oldest version of our root. normally, we'll find a | |
1151 | * MOD_LOG_KEY_REMOVE_WHILE_FREEING operation here. | |
1152 | */ | |
5d9e75c4 JS |
1153 | if (tm->op != MOD_LOG_ROOT_REPLACE) |
1154 | break; | |
1155 | ||
1156 | found = tm; | |
1157 | root_logical = tm->old_root.logical; | |
5d9e75c4 JS |
1158 | looped = 1; |
1159 | } | |
1160 | ||
a95236d9 JS |
1161 | /* if there's no old root to return, return what we found instead */ |
1162 | if (!found) | |
1163 | found = tm; | |
1164 | ||
5d9e75c4 JS |
1165 | return found; |
1166 | } | |
1167 | ||
1168 | /* | |
1169 | * tm is a pointer to the first operation to rewind within eb. then, all | |
01327610 | 1170 | * previous operations will be rewound (until we reach something older than |
5d9e75c4 JS |
1171 | * time_seq). |
1172 | */ | |
1173 | static void | |
f1ca7e98 JB |
1174 | __tree_mod_log_rewind(struct btrfs_fs_info *fs_info, struct extent_buffer *eb, |
1175 | u64 time_seq, struct tree_mod_elem *first_tm) | |
5d9e75c4 JS |
1176 | { |
1177 | u32 n; | |
1178 | struct rb_node *next; | |
1179 | struct tree_mod_elem *tm = first_tm; | |
1180 | unsigned long o_dst; | |
1181 | unsigned long o_src; | |
1182 | unsigned long p_size = sizeof(struct btrfs_key_ptr); | |
1183 | ||
1184 | n = btrfs_header_nritems(eb); | |
b1a09f1e | 1185 | read_lock(&fs_info->tree_mod_log_lock); |
097b8a7c | 1186 | while (tm && tm->seq >= time_seq) { |
5d9e75c4 JS |
1187 | /* |
1188 | * all the operations are recorded with the operator used for | |
1189 | * the modification. as we're going backwards, we do the | |
1190 | * opposite of each operation here. | |
1191 | */ | |
1192 | switch (tm->op) { | |
1193 | case MOD_LOG_KEY_REMOVE_WHILE_FREEING: | |
1194 | BUG_ON(tm->slot < n); | |
1c697d4a | 1195 | /* Fallthrough */ |
95c80bb1 | 1196 | case MOD_LOG_KEY_REMOVE_WHILE_MOVING: |
4c3e6969 | 1197 | case MOD_LOG_KEY_REMOVE: |
5d9e75c4 JS |
1198 | btrfs_set_node_key(eb, &tm->key, tm->slot); |
1199 | btrfs_set_node_blockptr(eb, tm->slot, tm->blockptr); | |
1200 | btrfs_set_node_ptr_generation(eb, tm->slot, | |
1201 | tm->generation); | |
4c3e6969 | 1202 | n++; |
5d9e75c4 JS |
1203 | break; |
1204 | case MOD_LOG_KEY_REPLACE: | |
1205 | BUG_ON(tm->slot >= n); | |
1206 | btrfs_set_node_key(eb, &tm->key, tm->slot); | |
1207 | btrfs_set_node_blockptr(eb, tm->slot, tm->blockptr); | |
1208 | btrfs_set_node_ptr_generation(eb, tm->slot, | |
1209 | tm->generation); | |
1210 | break; | |
1211 | case MOD_LOG_KEY_ADD: | |
19956c7e | 1212 | /* if a move operation is needed it's in the log */ |
5d9e75c4 JS |
1213 | n--; |
1214 | break; | |
1215 | case MOD_LOG_MOVE_KEYS: | |
c3193108 JS |
1216 | o_dst = btrfs_node_key_ptr_offset(tm->slot); |
1217 | o_src = btrfs_node_key_ptr_offset(tm->move.dst_slot); | |
1218 | memmove_extent_buffer(eb, o_dst, o_src, | |
5d9e75c4 JS |
1219 | tm->move.nr_items * p_size); |
1220 | break; | |
1221 | case MOD_LOG_ROOT_REPLACE: | |
1222 | /* | |
1223 | * this operation is special. for roots, this must be | |
1224 | * handled explicitly before rewinding. | |
1225 | * for non-roots, this operation may exist if the node | |
1226 | * was a root: root A -> child B; then A gets empty and | |
1227 | * B is promoted to the new root. in the mod log, we'll | |
1228 | * have a root-replace operation for B, a tree block | |
1229 | * that is no root. we simply ignore that operation. | |
1230 | */ | |
1231 | break; | |
1232 | } | |
1233 | next = rb_next(&tm->node); | |
1234 | if (!next) | |
1235 | break; | |
6b4df8b6 | 1236 | tm = rb_entry(next, struct tree_mod_elem, node); |
298cfd36 | 1237 | if (tm->logical != first_tm->logical) |
5d9e75c4 JS |
1238 | break; |
1239 | } | |
b1a09f1e | 1240 | read_unlock(&fs_info->tree_mod_log_lock); |
5d9e75c4 JS |
1241 | btrfs_set_header_nritems(eb, n); |
1242 | } | |
1243 | ||
47fb091f | 1244 | /* |
01327610 | 1245 | * Called with eb read locked. If the buffer cannot be rewound, the same buffer |
47fb091f JS |
1246 | * is returned. If rewind operations happen, a fresh buffer is returned. The |
1247 | * returned buffer is always read-locked. If the returned buffer is not the | |
1248 | * input buffer, the lock on the input buffer is released and the input buffer | |
1249 | * is freed (its refcount is decremented). | |
1250 | */ | |
5d9e75c4 | 1251 | static struct extent_buffer * |
9ec72677 JB |
1252 | tree_mod_log_rewind(struct btrfs_fs_info *fs_info, struct btrfs_path *path, |
1253 | struct extent_buffer *eb, u64 time_seq) | |
5d9e75c4 JS |
1254 | { |
1255 | struct extent_buffer *eb_rewin; | |
1256 | struct tree_mod_elem *tm; | |
1257 | ||
1258 | if (!time_seq) | |
1259 | return eb; | |
1260 | ||
1261 | if (btrfs_header_level(eb) == 0) | |
1262 | return eb; | |
1263 | ||
1264 | tm = tree_mod_log_search(fs_info, eb->start, time_seq); | |
1265 | if (!tm) | |
1266 | return eb; | |
1267 | ||
9ec72677 JB |
1268 | btrfs_set_path_blocking(path); |
1269 | btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK); | |
1270 | ||
5d9e75c4 JS |
1271 | if (tm->op == MOD_LOG_KEY_REMOVE_WHILE_FREEING) { |
1272 | BUG_ON(tm->slot != 0); | |
da17066c | 1273 | eb_rewin = alloc_dummy_extent_buffer(fs_info, eb->start); |
db7f3436 | 1274 | if (!eb_rewin) { |
9ec72677 | 1275 | btrfs_tree_read_unlock_blocking(eb); |
db7f3436 JB |
1276 | free_extent_buffer(eb); |
1277 | return NULL; | |
1278 | } | |
5d9e75c4 JS |
1279 | btrfs_set_header_bytenr(eb_rewin, eb->start); |
1280 | btrfs_set_header_backref_rev(eb_rewin, | |
1281 | btrfs_header_backref_rev(eb)); | |
1282 | btrfs_set_header_owner(eb_rewin, btrfs_header_owner(eb)); | |
c3193108 | 1283 | btrfs_set_header_level(eb_rewin, btrfs_header_level(eb)); |
5d9e75c4 JS |
1284 | } else { |
1285 | eb_rewin = btrfs_clone_extent_buffer(eb); | |
db7f3436 | 1286 | if (!eb_rewin) { |
9ec72677 | 1287 | btrfs_tree_read_unlock_blocking(eb); |
db7f3436 JB |
1288 | free_extent_buffer(eb); |
1289 | return NULL; | |
1290 | } | |
5d9e75c4 JS |
1291 | } |
1292 | ||
9ec72677 | 1293 | btrfs_tree_read_unlock_blocking(eb); |
5d9e75c4 JS |
1294 | free_extent_buffer(eb); |
1295 | ||
47fb091f | 1296 | btrfs_tree_read_lock(eb_rewin); |
f1ca7e98 | 1297 | __tree_mod_log_rewind(fs_info, eb_rewin, time_seq, tm); |
57911b8b | 1298 | WARN_ON(btrfs_header_nritems(eb_rewin) > |
da17066c | 1299 | BTRFS_NODEPTRS_PER_BLOCK(fs_info)); |
5d9e75c4 JS |
1300 | |
1301 | return eb_rewin; | |
1302 | } | |
1303 | ||
8ba97a15 JS |
1304 | /* |
1305 | * get_old_root() rewinds the state of @root's root node to the given @time_seq | |
1306 | * value. If there are no changes, the current root->root_node is returned. If | |
1307 | * anything changed in between, there's a fresh buffer allocated on which the | |
1308 | * rewind operations are done. In any case, the returned buffer is read locked. | |
1309 | * Returns NULL on error (with no locks held). | |
1310 | */ | |
5d9e75c4 JS |
1311 | static inline struct extent_buffer * |
1312 | get_old_root(struct btrfs_root *root, u64 time_seq) | |
1313 | { | |
0b246afa | 1314 | struct btrfs_fs_info *fs_info = root->fs_info; |
5d9e75c4 | 1315 | struct tree_mod_elem *tm; |
30b0463a JS |
1316 | struct extent_buffer *eb = NULL; |
1317 | struct extent_buffer *eb_root; | |
7bfdcf7f | 1318 | struct extent_buffer *old; |
a95236d9 | 1319 | struct tree_mod_root *old_root = NULL; |
4325edd0 | 1320 | u64 old_generation = 0; |
a95236d9 | 1321 | u64 logical; |
581c1760 | 1322 | int level; |
5d9e75c4 | 1323 | |
30b0463a | 1324 | eb_root = btrfs_read_lock_root_node(root); |
bcd24dab | 1325 | tm = __tree_mod_log_oldest_root(eb_root, time_seq); |
5d9e75c4 | 1326 | if (!tm) |
30b0463a | 1327 | return eb_root; |
5d9e75c4 | 1328 | |
a95236d9 JS |
1329 | if (tm->op == MOD_LOG_ROOT_REPLACE) { |
1330 | old_root = &tm->old_root; | |
1331 | old_generation = tm->generation; | |
1332 | logical = old_root->logical; | |
581c1760 | 1333 | level = old_root->level; |
a95236d9 | 1334 | } else { |
30b0463a | 1335 | logical = eb_root->start; |
581c1760 | 1336 | level = btrfs_header_level(eb_root); |
a95236d9 | 1337 | } |
5d9e75c4 | 1338 | |
0b246afa | 1339 | tm = tree_mod_log_search(fs_info, logical, time_seq); |
834328a8 | 1340 | if (old_root && tm && tm->op != MOD_LOG_KEY_REMOVE_WHILE_FREEING) { |
30b0463a JS |
1341 | btrfs_tree_read_unlock(eb_root); |
1342 | free_extent_buffer(eb_root); | |
581c1760 | 1343 | old = read_tree_block(fs_info, logical, 0, level, NULL); |
64c043de LB |
1344 | if (WARN_ON(IS_ERR(old) || !extent_buffer_uptodate(old))) { |
1345 | if (!IS_ERR(old)) | |
1346 | free_extent_buffer(old); | |
0b246afa JM |
1347 | btrfs_warn(fs_info, |
1348 | "failed to read tree block %llu from get_old_root", | |
1349 | logical); | |
834328a8 | 1350 | } else { |
7bfdcf7f LB |
1351 | eb = btrfs_clone_extent_buffer(old); |
1352 | free_extent_buffer(old); | |
834328a8 JS |
1353 | } |
1354 | } else if (old_root) { | |
30b0463a JS |
1355 | btrfs_tree_read_unlock(eb_root); |
1356 | free_extent_buffer(eb_root); | |
0b246afa | 1357 | eb = alloc_dummy_extent_buffer(fs_info, logical); |
834328a8 | 1358 | } else { |
9ec72677 | 1359 | btrfs_set_lock_blocking_rw(eb_root, BTRFS_READ_LOCK); |
30b0463a | 1360 | eb = btrfs_clone_extent_buffer(eb_root); |
9ec72677 | 1361 | btrfs_tree_read_unlock_blocking(eb_root); |
30b0463a | 1362 | free_extent_buffer(eb_root); |
834328a8 JS |
1363 | } |
1364 | ||
8ba97a15 JS |
1365 | if (!eb) |
1366 | return NULL; | |
1367 | btrfs_tree_read_lock(eb); | |
a95236d9 | 1368 | if (old_root) { |
5d9e75c4 JS |
1369 | btrfs_set_header_bytenr(eb, eb->start); |
1370 | btrfs_set_header_backref_rev(eb, BTRFS_MIXED_BACKREF_REV); | |
30b0463a | 1371 | btrfs_set_header_owner(eb, btrfs_header_owner(eb_root)); |
a95236d9 JS |
1372 | btrfs_set_header_level(eb, old_root->level); |
1373 | btrfs_set_header_generation(eb, old_generation); | |
5d9e75c4 | 1374 | } |
28da9fb4 | 1375 | if (tm) |
0b246afa | 1376 | __tree_mod_log_rewind(fs_info, eb, time_seq, tm); |
28da9fb4 JS |
1377 | else |
1378 | WARN_ON(btrfs_header_level(eb) != 0); | |
0b246afa | 1379 | WARN_ON(btrfs_header_nritems(eb) > BTRFS_NODEPTRS_PER_BLOCK(fs_info)); |
5d9e75c4 JS |
1380 | |
1381 | return eb; | |
1382 | } | |
1383 | ||
5b6602e7 JS |
1384 | int btrfs_old_root_level(struct btrfs_root *root, u64 time_seq) |
1385 | { | |
1386 | struct tree_mod_elem *tm; | |
1387 | int level; | |
30b0463a | 1388 | struct extent_buffer *eb_root = btrfs_root_node(root); |
5b6602e7 | 1389 | |
bcd24dab | 1390 | tm = __tree_mod_log_oldest_root(eb_root, time_seq); |
5b6602e7 JS |
1391 | if (tm && tm->op == MOD_LOG_ROOT_REPLACE) { |
1392 | level = tm->old_root.level; | |
1393 | } else { | |
30b0463a | 1394 | level = btrfs_header_level(eb_root); |
5b6602e7 | 1395 | } |
30b0463a | 1396 | free_extent_buffer(eb_root); |
5b6602e7 JS |
1397 | |
1398 | return level; | |
1399 | } | |
1400 | ||
5d4f98a2 YZ |
1401 | static inline int should_cow_block(struct btrfs_trans_handle *trans, |
1402 | struct btrfs_root *root, | |
1403 | struct extent_buffer *buf) | |
1404 | { | |
f5ee5c9a | 1405 | if (btrfs_is_testing(root->fs_info)) |
faa2dbf0 | 1406 | return 0; |
fccb84c9 | 1407 | |
d1980131 DS |
1408 | /* Ensure we can see the FORCE_COW bit */ |
1409 | smp_mb__before_atomic(); | |
f1ebcc74 LB |
1410 | |
1411 | /* | |
1412 | * We do not need to cow a block if | |
1413 | * 1) this block is not created or changed in this transaction; | |
1414 | * 2) this block does not belong to TREE_RELOC tree; | |
1415 | * 3) the root is not forced COW. | |
1416 | * | |
1417 | * What is forced COW: | |
01327610 | 1418 | * when we create snapshot during committing the transaction, |
52042d8e | 1419 | * after we've finished copying src root, we must COW the shared |
f1ebcc74 LB |
1420 | * block to ensure the metadata consistency. |
1421 | */ | |
5d4f98a2 YZ |
1422 | if (btrfs_header_generation(buf) == trans->transid && |
1423 | !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN) && | |
1424 | !(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID && | |
f1ebcc74 | 1425 | btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC)) && |
27cdeb70 | 1426 | !test_bit(BTRFS_ROOT_FORCE_COW, &root->state)) |
5d4f98a2 YZ |
1427 | return 0; |
1428 | return 1; | |
1429 | } | |
1430 | ||
d352ac68 CM |
1431 | /* |
1432 | * cows a single block, see __btrfs_cow_block for the real work. | |
01327610 | 1433 | * This version of it has extra checks so that a block isn't COWed more than |
d352ac68 CM |
1434 | * once per transaction, as long as it hasn't been written yet |
1435 | */ | |
d397712b | 1436 | noinline int btrfs_cow_block(struct btrfs_trans_handle *trans, |
5f39d397 CM |
1437 | struct btrfs_root *root, struct extent_buffer *buf, |
1438 | struct extent_buffer *parent, int parent_slot, | |
9fa8cfe7 | 1439 | struct extent_buffer **cow_ret) |
6702ed49 | 1440 | { |
0b246afa | 1441 | struct btrfs_fs_info *fs_info = root->fs_info; |
6702ed49 | 1442 | u64 search_start; |
f510cfec | 1443 | int ret; |
dc17ff8f | 1444 | |
83354f07 JB |
1445 | if (test_bit(BTRFS_ROOT_DELETING, &root->state)) |
1446 | btrfs_err(fs_info, | |
1447 | "COW'ing blocks on a fs root that's being dropped"); | |
1448 | ||
0b246afa | 1449 | if (trans->transaction != fs_info->running_transaction) |
31b1a2bd | 1450 | WARN(1, KERN_CRIT "trans %llu running %llu\n", |
c1c9ff7c | 1451 | trans->transid, |
0b246afa | 1452 | fs_info->running_transaction->transid); |
31b1a2bd | 1453 | |
0b246afa | 1454 | if (trans->transid != fs_info->generation) |
31b1a2bd | 1455 | WARN(1, KERN_CRIT "trans %llu running %llu\n", |
0b246afa | 1456 | trans->transid, fs_info->generation); |
dc17ff8f | 1457 | |
5d4f98a2 | 1458 | if (!should_cow_block(trans, root, buf)) { |
64c12921 | 1459 | trans->dirty = true; |
6702ed49 CM |
1460 | *cow_ret = buf; |
1461 | return 0; | |
1462 | } | |
c487685d | 1463 | |
ee22184b | 1464 | search_start = buf->start & ~((u64)SZ_1G - 1); |
b4ce94de CM |
1465 | |
1466 | if (parent) | |
1467 | btrfs_set_lock_blocking(parent); | |
1468 | btrfs_set_lock_blocking(buf); | |
1469 | ||
f510cfec | 1470 | ret = __btrfs_cow_block(trans, root, buf, parent, |
9fa8cfe7 | 1471 | parent_slot, cow_ret, search_start, 0); |
1abe9b8a | 1472 | |
1473 | trace_btrfs_cow_block(root, buf, *cow_ret); | |
1474 | ||
f510cfec | 1475 | return ret; |
6702ed49 CM |
1476 | } |
1477 | ||
d352ac68 CM |
1478 | /* |
1479 | * helper function for defrag to decide if two blocks pointed to by a | |
1480 | * node are actually close by | |
1481 | */ | |
6b80053d | 1482 | static int close_blocks(u64 blocknr, u64 other, u32 blocksize) |
6702ed49 | 1483 | { |
6b80053d | 1484 | if (blocknr < other && other - (blocknr + blocksize) < 32768) |
6702ed49 | 1485 | return 1; |
6b80053d | 1486 | if (blocknr > other && blocknr - (other + blocksize) < 32768) |
6702ed49 CM |
1487 | return 1; |
1488 | return 0; | |
1489 | } | |
1490 | ||
081e9573 CM |
1491 | /* |
1492 | * compare two keys in a memcmp fashion | |
1493 | */ | |
310712b2 OS |
1494 | static int comp_keys(const struct btrfs_disk_key *disk, |
1495 | const struct btrfs_key *k2) | |
081e9573 CM |
1496 | { |
1497 | struct btrfs_key k1; | |
1498 | ||
1499 | btrfs_disk_key_to_cpu(&k1, disk); | |
1500 | ||
20736aba | 1501 | return btrfs_comp_cpu_keys(&k1, k2); |
081e9573 CM |
1502 | } |
1503 | ||
f3465ca4 JB |
1504 | /* |
1505 | * same as comp_keys only with two btrfs_key's | |
1506 | */ | |
310712b2 | 1507 | int btrfs_comp_cpu_keys(const struct btrfs_key *k1, const struct btrfs_key *k2) |
f3465ca4 JB |
1508 | { |
1509 | if (k1->objectid > k2->objectid) | |
1510 | return 1; | |
1511 | if (k1->objectid < k2->objectid) | |
1512 | return -1; | |
1513 | if (k1->type > k2->type) | |
1514 | return 1; | |
1515 | if (k1->type < k2->type) | |
1516 | return -1; | |
1517 | if (k1->offset > k2->offset) | |
1518 | return 1; | |
1519 | if (k1->offset < k2->offset) | |
1520 | return -1; | |
1521 | return 0; | |
1522 | } | |
081e9573 | 1523 | |
d352ac68 CM |
1524 | /* |
1525 | * this is used by the defrag code to go through all the | |
1526 | * leaves pointed to by a node and reallocate them so that | |
1527 | * disk order is close to key order | |
1528 | */ | |
6702ed49 | 1529 | int btrfs_realloc_node(struct btrfs_trans_handle *trans, |
5f39d397 | 1530 | struct btrfs_root *root, struct extent_buffer *parent, |
de78b51a | 1531 | int start_slot, u64 *last_ret, |
a6b6e75e | 1532 | struct btrfs_key *progress) |
6702ed49 | 1533 | { |
0b246afa | 1534 | struct btrfs_fs_info *fs_info = root->fs_info; |
6b80053d | 1535 | struct extent_buffer *cur; |
6702ed49 | 1536 | u64 blocknr; |
ca7a79ad | 1537 | u64 gen; |
e9d0b13b CM |
1538 | u64 search_start = *last_ret; |
1539 | u64 last_block = 0; | |
6702ed49 CM |
1540 | u64 other; |
1541 | u32 parent_nritems; | |
6702ed49 CM |
1542 | int end_slot; |
1543 | int i; | |
1544 | int err = 0; | |
f2183bde | 1545 | int parent_level; |
6b80053d CM |
1546 | int uptodate; |
1547 | u32 blocksize; | |
081e9573 CM |
1548 | int progress_passed = 0; |
1549 | struct btrfs_disk_key disk_key; | |
6702ed49 | 1550 | |
5708b959 | 1551 | parent_level = btrfs_header_level(parent); |
5708b959 | 1552 | |
0b246afa JM |
1553 | WARN_ON(trans->transaction != fs_info->running_transaction); |
1554 | WARN_ON(trans->transid != fs_info->generation); | |
86479a04 | 1555 | |
6b80053d | 1556 | parent_nritems = btrfs_header_nritems(parent); |
0b246afa | 1557 | blocksize = fs_info->nodesize; |
5dfe2be7 | 1558 | end_slot = parent_nritems - 1; |
6702ed49 | 1559 | |
5dfe2be7 | 1560 | if (parent_nritems <= 1) |
6702ed49 CM |
1561 | return 0; |
1562 | ||
b4ce94de CM |
1563 | btrfs_set_lock_blocking(parent); |
1564 | ||
5dfe2be7 | 1565 | for (i = start_slot; i <= end_slot; i++) { |
581c1760 | 1566 | struct btrfs_key first_key; |
6702ed49 | 1567 | int close = 1; |
a6b6e75e | 1568 | |
081e9573 CM |
1569 | btrfs_node_key(parent, &disk_key, i); |
1570 | if (!progress_passed && comp_keys(&disk_key, progress) < 0) | |
1571 | continue; | |
1572 | ||
1573 | progress_passed = 1; | |
6b80053d | 1574 | blocknr = btrfs_node_blockptr(parent, i); |
ca7a79ad | 1575 | gen = btrfs_node_ptr_generation(parent, i); |
581c1760 | 1576 | btrfs_node_key_to_cpu(parent, &first_key, i); |
e9d0b13b CM |
1577 | if (last_block == 0) |
1578 | last_block = blocknr; | |
5708b959 | 1579 | |
6702ed49 | 1580 | if (i > 0) { |
6b80053d CM |
1581 | other = btrfs_node_blockptr(parent, i - 1); |
1582 | close = close_blocks(blocknr, other, blocksize); | |
6702ed49 | 1583 | } |
5dfe2be7 | 1584 | if (!close && i < end_slot) { |
6b80053d CM |
1585 | other = btrfs_node_blockptr(parent, i + 1); |
1586 | close = close_blocks(blocknr, other, blocksize); | |
6702ed49 | 1587 | } |
e9d0b13b CM |
1588 | if (close) { |
1589 | last_block = blocknr; | |
6702ed49 | 1590 | continue; |
e9d0b13b | 1591 | } |
6702ed49 | 1592 | |
0b246afa | 1593 | cur = find_extent_buffer(fs_info, blocknr); |
6b80053d | 1594 | if (cur) |
b9fab919 | 1595 | uptodate = btrfs_buffer_uptodate(cur, gen, 0); |
6b80053d CM |
1596 | else |
1597 | uptodate = 0; | |
5708b959 | 1598 | if (!cur || !uptodate) { |
6b80053d | 1599 | if (!cur) { |
581c1760 QW |
1600 | cur = read_tree_block(fs_info, blocknr, gen, |
1601 | parent_level - 1, | |
1602 | &first_key); | |
64c043de LB |
1603 | if (IS_ERR(cur)) { |
1604 | return PTR_ERR(cur); | |
1605 | } else if (!extent_buffer_uptodate(cur)) { | |
416bc658 | 1606 | free_extent_buffer(cur); |
97d9a8a4 | 1607 | return -EIO; |
416bc658 | 1608 | } |
6b80053d | 1609 | } else if (!uptodate) { |
581c1760 QW |
1610 | err = btrfs_read_buffer(cur, gen, |
1611 | parent_level - 1,&first_key); | |
018642a1 TI |
1612 | if (err) { |
1613 | free_extent_buffer(cur); | |
1614 | return err; | |
1615 | } | |
f2183bde | 1616 | } |
6702ed49 | 1617 | } |
e9d0b13b | 1618 | if (search_start == 0) |
6b80053d | 1619 | search_start = last_block; |
e9d0b13b | 1620 | |
e7a84565 | 1621 | btrfs_tree_lock(cur); |
b4ce94de | 1622 | btrfs_set_lock_blocking(cur); |
6b80053d | 1623 | err = __btrfs_cow_block(trans, root, cur, parent, i, |
e7a84565 | 1624 | &cur, search_start, |
6b80053d | 1625 | min(16 * blocksize, |
9fa8cfe7 | 1626 | (end_slot - i) * blocksize)); |
252c38f0 | 1627 | if (err) { |
e7a84565 | 1628 | btrfs_tree_unlock(cur); |
6b80053d | 1629 | free_extent_buffer(cur); |
6702ed49 | 1630 | break; |
252c38f0 | 1631 | } |
e7a84565 CM |
1632 | search_start = cur->start; |
1633 | last_block = cur->start; | |
f2183bde | 1634 | *last_ret = search_start; |
e7a84565 CM |
1635 | btrfs_tree_unlock(cur); |
1636 | free_extent_buffer(cur); | |
6702ed49 CM |
1637 | } |
1638 | return err; | |
1639 | } | |
1640 | ||
74123bd7 | 1641 | /* |
5f39d397 CM |
1642 | * search for key in the extent_buffer. The items start at offset p, |
1643 | * and they are item_size apart. There are 'max' items in p. | |
1644 | * | |
74123bd7 CM |
1645 | * the slot in the array is returned via slot, and it points to |
1646 | * the place where you would insert key if it is not found in | |
1647 | * the array. | |
1648 | * | |
1649 | * slot may point to max if the key is bigger than all of the keys | |
1650 | */ | |
e02119d5 | 1651 | static noinline int generic_bin_search(struct extent_buffer *eb, |
310712b2 OS |
1652 | unsigned long p, int item_size, |
1653 | const struct btrfs_key *key, | |
e02119d5 | 1654 | int max, int *slot) |
be0e5c09 CM |
1655 | { |
1656 | int low = 0; | |
1657 | int high = max; | |
1658 | int mid; | |
1659 | int ret; | |
479965d6 | 1660 | struct btrfs_disk_key *tmp = NULL; |
5f39d397 CM |
1661 | struct btrfs_disk_key unaligned; |
1662 | unsigned long offset; | |
5f39d397 CM |
1663 | char *kaddr = NULL; |
1664 | unsigned long map_start = 0; | |
1665 | unsigned long map_len = 0; | |
479965d6 | 1666 | int err; |
be0e5c09 | 1667 | |
5e24e9af LB |
1668 | if (low > high) { |
1669 | btrfs_err(eb->fs_info, | |
1670 | "%s: low (%d) > high (%d) eb %llu owner %llu level %d", | |
1671 | __func__, low, high, eb->start, | |
1672 | btrfs_header_owner(eb), btrfs_header_level(eb)); | |
1673 | return -EINVAL; | |
1674 | } | |
1675 | ||
d397712b | 1676 | while (low < high) { |
be0e5c09 | 1677 | mid = (low + high) / 2; |
5f39d397 CM |
1678 | offset = p + mid * item_size; |
1679 | ||
a6591715 | 1680 | if (!kaddr || offset < map_start || |
5f39d397 CM |
1681 | (offset + sizeof(struct btrfs_disk_key)) > |
1682 | map_start + map_len) { | |
934d375b CM |
1683 | |
1684 | err = map_private_extent_buffer(eb, offset, | |
479965d6 | 1685 | sizeof(struct btrfs_disk_key), |
a6591715 | 1686 | &kaddr, &map_start, &map_len); |
479965d6 CM |
1687 | |
1688 | if (!err) { | |
1689 | tmp = (struct btrfs_disk_key *)(kaddr + offset - | |
1690 | map_start); | |
415b35a5 | 1691 | } else if (err == 1) { |
479965d6 CM |
1692 | read_extent_buffer(eb, &unaligned, |
1693 | offset, sizeof(unaligned)); | |
1694 | tmp = &unaligned; | |
415b35a5 LB |
1695 | } else { |
1696 | return err; | |
479965d6 | 1697 | } |
5f39d397 | 1698 | |
5f39d397 CM |
1699 | } else { |
1700 | tmp = (struct btrfs_disk_key *)(kaddr + offset - | |
1701 | map_start); | |
1702 | } | |
be0e5c09 CM |
1703 | ret = comp_keys(tmp, key); |
1704 | ||
1705 | if (ret < 0) | |
1706 | low = mid + 1; | |
1707 | else if (ret > 0) | |
1708 | high = mid; | |
1709 | else { | |
1710 | *slot = mid; | |
1711 | return 0; | |
1712 | } | |
1713 | } | |
1714 | *slot = low; | |
1715 | return 1; | |
1716 | } | |
1717 | ||
97571fd0 CM |
1718 | /* |
1719 | * simple bin_search frontend that does the right thing for | |
1720 | * leaves vs nodes | |
1721 | */ | |
a74b35ec NB |
1722 | int btrfs_bin_search(struct extent_buffer *eb, const struct btrfs_key *key, |
1723 | int level, int *slot) | |
be0e5c09 | 1724 | { |
f775738f | 1725 | if (level == 0) |
5f39d397 CM |
1726 | return generic_bin_search(eb, |
1727 | offsetof(struct btrfs_leaf, items), | |
0783fcfc | 1728 | sizeof(struct btrfs_item), |
5f39d397 | 1729 | key, btrfs_header_nritems(eb), |
7518a238 | 1730 | slot); |
f775738f | 1731 | else |
5f39d397 CM |
1732 | return generic_bin_search(eb, |
1733 | offsetof(struct btrfs_node, ptrs), | |
123abc88 | 1734 | sizeof(struct btrfs_key_ptr), |
5f39d397 | 1735 | key, btrfs_header_nritems(eb), |
7518a238 | 1736 | slot); |
be0e5c09 CM |
1737 | } |
1738 | ||
f0486c68 YZ |
1739 | static void root_add_used(struct btrfs_root *root, u32 size) |
1740 | { | |
1741 | spin_lock(&root->accounting_lock); | |
1742 | btrfs_set_root_used(&root->root_item, | |
1743 | btrfs_root_used(&root->root_item) + size); | |
1744 | spin_unlock(&root->accounting_lock); | |
1745 | } | |
1746 | ||
1747 | static void root_sub_used(struct btrfs_root *root, u32 size) | |
1748 | { | |
1749 | spin_lock(&root->accounting_lock); | |
1750 | btrfs_set_root_used(&root->root_item, | |
1751 | btrfs_root_used(&root->root_item) - size); | |
1752 | spin_unlock(&root->accounting_lock); | |
1753 | } | |
1754 | ||
d352ac68 CM |
1755 | /* given a node and slot number, this reads the blocks it points to. The |
1756 | * extent buffer is returned with a reference taken (but unlocked). | |
d352ac68 | 1757 | */ |
2ff7e61e JM |
1758 | static noinline struct extent_buffer * |
1759 | read_node_slot(struct btrfs_fs_info *fs_info, struct extent_buffer *parent, | |
1760 | int slot) | |
bb803951 | 1761 | { |
ca7a79ad | 1762 | int level = btrfs_header_level(parent); |
416bc658 | 1763 | struct extent_buffer *eb; |
581c1760 | 1764 | struct btrfs_key first_key; |
416bc658 | 1765 | |
fb770ae4 LB |
1766 | if (slot < 0 || slot >= btrfs_header_nritems(parent)) |
1767 | return ERR_PTR(-ENOENT); | |
ca7a79ad CM |
1768 | |
1769 | BUG_ON(level == 0); | |
1770 | ||
581c1760 | 1771 | btrfs_node_key_to_cpu(parent, &first_key, slot); |
2ff7e61e | 1772 | eb = read_tree_block(fs_info, btrfs_node_blockptr(parent, slot), |
581c1760 QW |
1773 | btrfs_node_ptr_generation(parent, slot), |
1774 | level - 1, &first_key); | |
fb770ae4 LB |
1775 | if (!IS_ERR(eb) && !extent_buffer_uptodate(eb)) { |
1776 | free_extent_buffer(eb); | |
1777 | eb = ERR_PTR(-EIO); | |
416bc658 JB |
1778 | } |
1779 | ||
1780 | return eb; | |
bb803951 CM |
1781 | } |
1782 | ||
d352ac68 CM |
1783 | /* |
1784 | * node level balancing, used to make sure nodes are in proper order for | |
1785 | * item deletion. We balance from the top down, so we have to make sure | |
1786 | * that a deletion won't leave an node completely empty later on. | |
1787 | */ | |
e02119d5 | 1788 | static noinline int balance_level(struct btrfs_trans_handle *trans, |
98ed5174 CM |
1789 | struct btrfs_root *root, |
1790 | struct btrfs_path *path, int level) | |
bb803951 | 1791 | { |
0b246afa | 1792 | struct btrfs_fs_info *fs_info = root->fs_info; |
5f39d397 CM |
1793 | struct extent_buffer *right = NULL; |
1794 | struct extent_buffer *mid; | |
1795 | struct extent_buffer *left = NULL; | |
1796 | struct extent_buffer *parent = NULL; | |
bb803951 CM |
1797 | int ret = 0; |
1798 | int wret; | |
1799 | int pslot; | |
bb803951 | 1800 | int orig_slot = path->slots[level]; |
79f95c82 | 1801 | u64 orig_ptr; |
bb803951 | 1802 | |
98e6b1eb | 1803 | ASSERT(level > 0); |
bb803951 | 1804 | |
5f39d397 | 1805 | mid = path->nodes[level]; |
b4ce94de | 1806 | |
bd681513 CM |
1807 | WARN_ON(path->locks[level] != BTRFS_WRITE_LOCK && |
1808 | path->locks[level] != BTRFS_WRITE_LOCK_BLOCKING); | |
7bb86316 CM |
1809 | WARN_ON(btrfs_header_generation(mid) != trans->transid); |
1810 | ||
1d4f8a0c | 1811 | orig_ptr = btrfs_node_blockptr(mid, orig_slot); |
79f95c82 | 1812 | |
a05a9bb1 | 1813 | if (level < BTRFS_MAX_LEVEL - 1) { |
5f39d397 | 1814 | parent = path->nodes[level + 1]; |
a05a9bb1 LZ |
1815 | pslot = path->slots[level + 1]; |
1816 | } | |
bb803951 | 1817 | |
40689478 CM |
1818 | /* |
1819 | * deal with the case where there is only one pointer in the root | |
1820 | * by promoting the node below to a root | |
1821 | */ | |
5f39d397 CM |
1822 | if (!parent) { |
1823 | struct extent_buffer *child; | |
bb803951 | 1824 | |
5f39d397 | 1825 | if (btrfs_header_nritems(mid) != 1) |
bb803951 CM |
1826 | return 0; |
1827 | ||
1828 | /* promote the child to a root */ | |
2ff7e61e | 1829 | child = read_node_slot(fs_info, mid, 0); |
fb770ae4 LB |
1830 | if (IS_ERR(child)) { |
1831 | ret = PTR_ERR(child); | |
0b246afa | 1832 | btrfs_handle_fs_error(fs_info, ret, NULL); |
305a26af MF |
1833 | goto enospc; |
1834 | } | |
1835 | ||
925baedd | 1836 | btrfs_tree_lock(child); |
b4ce94de | 1837 | btrfs_set_lock_blocking(child); |
9fa8cfe7 | 1838 | ret = btrfs_cow_block(trans, root, child, mid, 0, &child); |
f0486c68 YZ |
1839 | if (ret) { |
1840 | btrfs_tree_unlock(child); | |
1841 | free_extent_buffer(child); | |
1842 | goto enospc; | |
1843 | } | |
2f375ab9 | 1844 | |
d9d19a01 DS |
1845 | ret = tree_mod_log_insert_root(root->node, child, 1); |
1846 | BUG_ON(ret < 0); | |
240f62c8 | 1847 | rcu_assign_pointer(root->node, child); |
925baedd | 1848 | |
0b86a832 | 1849 | add_root_to_dirty_list(root); |
925baedd | 1850 | btrfs_tree_unlock(child); |
b4ce94de | 1851 | |
925baedd | 1852 | path->locks[level] = 0; |
bb803951 | 1853 | path->nodes[level] = NULL; |
7c302b49 | 1854 | clean_tree_block(fs_info, mid); |
925baedd | 1855 | btrfs_tree_unlock(mid); |
bb803951 | 1856 | /* once for the path */ |
5f39d397 | 1857 | free_extent_buffer(mid); |
f0486c68 YZ |
1858 | |
1859 | root_sub_used(root, mid->len); | |
5581a51a | 1860 | btrfs_free_tree_block(trans, root, mid, 0, 1); |
bb803951 | 1861 | /* once for the root ptr */ |
3083ee2e | 1862 | free_extent_buffer_stale(mid); |
f0486c68 | 1863 | return 0; |
bb803951 | 1864 | } |
5f39d397 | 1865 | if (btrfs_header_nritems(mid) > |
0b246afa | 1866 | BTRFS_NODEPTRS_PER_BLOCK(fs_info) / 4) |
bb803951 CM |
1867 | return 0; |
1868 | ||
2ff7e61e | 1869 | left = read_node_slot(fs_info, parent, pslot - 1); |
fb770ae4 LB |
1870 | if (IS_ERR(left)) |
1871 | left = NULL; | |
1872 | ||
5f39d397 | 1873 | if (left) { |
925baedd | 1874 | btrfs_tree_lock(left); |
b4ce94de | 1875 | btrfs_set_lock_blocking(left); |
5f39d397 | 1876 | wret = btrfs_cow_block(trans, root, left, |
9fa8cfe7 | 1877 | parent, pslot - 1, &left); |
54aa1f4d CM |
1878 | if (wret) { |
1879 | ret = wret; | |
1880 | goto enospc; | |
1881 | } | |
2cc58cf2 | 1882 | } |
fb770ae4 | 1883 | |
2ff7e61e | 1884 | right = read_node_slot(fs_info, parent, pslot + 1); |
fb770ae4 LB |
1885 | if (IS_ERR(right)) |
1886 | right = NULL; | |
1887 | ||
5f39d397 | 1888 | if (right) { |
925baedd | 1889 | btrfs_tree_lock(right); |
b4ce94de | 1890 | btrfs_set_lock_blocking(right); |
5f39d397 | 1891 | wret = btrfs_cow_block(trans, root, right, |
9fa8cfe7 | 1892 | parent, pslot + 1, &right); |
2cc58cf2 CM |
1893 | if (wret) { |
1894 | ret = wret; | |
1895 | goto enospc; | |
1896 | } | |
1897 | } | |
1898 | ||
1899 | /* first, try to make some room in the middle buffer */ | |
5f39d397 CM |
1900 | if (left) { |
1901 | orig_slot += btrfs_header_nritems(left); | |
2ff7e61e | 1902 | wret = push_node_left(trans, fs_info, left, mid, 1); |
79f95c82 CM |
1903 | if (wret < 0) |
1904 | ret = wret; | |
bb803951 | 1905 | } |
79f95c82 CM |
1906 | |
1907 | /* | |
1908 | * then try to empty the right most buffer into the middle | |
1909 | */ | |
5f39d397 | 1910 | if (right) { |
2ff7e61e | 1911 | wret = push_node_left(trans, fs_info, mid, right, 1); |
54aa1f4d | 1912 | if (wret < 0 && wret != -ENOSPC) |
79f95c82 | 1913 | ret = wret; |
5f39d397 | 1914 | if (btrfs_header_nritems(right) == 0) { |
7c302b49 | 1915 | clean_tree_block(fs_info, right); |
925baedd | 1916 | btrfs_tree_unlock(right); |
afe5fea7 | 1917 | del_ptr(root, path, level + 1, pslot + 1); |
f0486c68 | 1918 | root_sub_used(root, right->len); |
5581a51a | 1919 | btrfs_free_tree_block(trans, root, right, 0, 1); |
3083ee2e | 1920 | free_extent_buffer_stale(right); |
f0486c68 | 1921 | right = NULL; |
bb803951 | 1922 | } else { |
5f39d397 CM |
1923 | struct btrfs_disk_key right_key; |
1924 | btrfs_node_key(right, &right_key, 0); | |
0e82bcfe DS |
1925 | ret = tree_mod_log_insert_key(parent, pslot + 1, |
1926 | MOD_LOG_KEY_REPLACE, GFP_NOFS); | |
1927 | BUG_ON(ret < 0); | |
5f39d397 CM |
1928 | btrfs_set_node_key(parent, &right_key, pslot + 1); |
1929 | btrfs_mark_buffer_dirty(parent); | |
bb803951 CM |
1930 | } |
1931 | } | |
5f39d397 | 1932 | if (btrfs_header_nritems(mid) == 1) { |
79f95c82 CM |
1933 | /* |
1934 | * we're not allowed to leave a node with one item in the | |
1935 | * tree during a delete. A deletion from lower in the tree | |
1936 | * could try to delete the only pointer in this node. | |
1937 | * So, pull some keys from the left. | |
1938 | * There has to be a left pointer at this point because | |
1939 | * otherwise we would have pulled some pointers from the | |
1940 | * right | |
1941 | */ | |
305a26af MF |
1942 | if (!left) { |
1943 | ret = -EROFS; | |
0b246afa | 1944 | btrfs_handle_fs_error(fs_info, ret, NULL); |
305a26af MF |
1945 | goto enospc; |
1946 | } | |
2ff7e61e | 1947 | wret = balance_node_right(trans, fs_info, mid, left); |
54aa1f4d | 1948 | if (wret < 0) { |
79f95c82 | 1949 | ret = wret; |
54aa1f4d CM |
1950 | goto enospc; |
1951 | } | |
bce4eae9 | 1952 | if (wret == 1) { |
2ff7e61e | 1953 | wret = push_node_left(trans, fs_info, left, mid, 1); |
bce4eae9 CM |
1954 | if (wret < 0) |
1955 | ret = wret; | |
1956 | } | |
79f95c82 CM |
1957 | BUG_ON(wret == 1); |
1958 | } | |
5f39d397 | 1959 | if (btrfs_header_nritems(mid) == 0) { |
7c302b49 | 1960 | clean_tree_block(fs_info, mid); |
925baedd | 1961 | btrfs_tree_unlock(mid); |
afe5fea7 | 1962 | del_ptr(root, path, level + 1, pslot); |
f0486c68 | 1963 | root_sub_used(root, mid->len); |
5581a51a | 1964 | btrfs_free_tree_block(trans, root, mid, 0, 1); |
3083ee2e | 1965 | free_extent_buffer_stale(mid); |
f0486c68 | 1966 | mid = NULL; |
79f95c82 CM |
1967 | } else { |
1968 | /* update the parent key to reflect our changes */ | |
5f39d397 CM |
1969 | struct btrfs_disk_key mid_key; |
1970 | btrfs_node_key(mid, &mid_key, 0); | |
0e82bcfe DS |
1971 | ret = tree_mod_log_insert_key(parent, pslot, |
1972 | MOD_LOG_KEY_REPLACE, GFP_NOFS); | |
1973 | BUG_ON(ret < 0); | |
5f39d397 CM |
1974 | btrfs_set_node_key(parent, &mid_key, pslot); |
1975 | btrfs_mark_buffer_dirty(parent); | |
79f95c82 | 1976 | } |
bb803951 | 1977 | |
79f95c82 | 1978 | /* update the path */ |
5f39d397 CM |
1979 | if (left) { |
1980 | if (btrfs_header_nritems(left) > orig_slot) { | |
1981 | extent_buffer_get(left); | |
925baedd | 1982 | /* left was locked after cow */ |
5f39d397 | 1983 | path->nodes[level] = left; |
bb803951 CM |
1984 | path->slots[level + 1] -= 1; |
1985 | path->slots[level] = orig_slot; | |
925baedd CM |
1986 | if (mid) { |
1987 | btrfs_tree_unlock(mid); | |
5f39d397 | 1988 | free_extent_buffer(mid); |
925baedd | 1989 | } |
bb803951 | 1990 | } else { |
5f39d397 | 1991 | orig_slot -= btrfs_header_nritems(left); |
bb803951 CM |
1992 | path->slots[level] = orig_slot; |
1993 | } | |
1994 | } | |
79f95c82 | 1995 | /* double check we haven't messed things up */ |
e20d96d6 | 1996 | if (orig_ptr != |
5f39d397 | 1997 | btrfs_node_blockptr(path->nodes[level], path->slots[level])) |
79f95c82 | 1998 | BUG(); |
54aa1f4d | 1999 | enospc: |
925baedd CM |
2000 | if (right) { |
2001 | btrfs_tree_unlock(right); | |
5f39d397 | 2002 | free_extent_buffer(right); |
925baedd CM |
2003 | } |
2004 | if (left) { | |
2005 | if (path->nodes[level] != left) | |
2006 | btrfs_tree_unlock(left); | |
5f39d397 | 2007 | free_extent_buffer(left); |
925baedd | 2008 | } |
bb803951 CM |
2009 | return ret; |
2010 | } | |
2011 | ||
d352ac68 CM |
2012 | /* Node balancing for insertion. Here we only split or push nodes around |
2013 | * when they are completely full. This is also done top down, so we | |
2014 | * have to be pessimistic. | |
2015 | */ | |
d397712b | 2016 | static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans, |
98ed5174 CM |
2017 | struct btrfs_root *root, |
2018 | struct btrfs_path *path, int level) | |
e66f709b | 2019 | { |
0b246afa | 2020 | struct btrfs_fs_info *fs_info = root->fs_info; |
5f39d397 CM |
2021 | struct extent_buffer *right = NULL; |
2022 | struct extent_buffer *mid; | |
2023 | struct extent_buffer *left = NULL; | |
2024 | struct extent_buffer *parent = NULL; | |
e66f709b CM |
2025 | int ret = 0; |
2026 | int wret; | |
2027 | int pslot; | |
2028 | int orig_slot = path->slots[level]; | |
e66f709b CM |
2029 | |
2030 | if (level == 0) | |
2031 | return 1; | |
2032 | ||
5f39d397 | 2033 | mid = path->nodes[level]; |
7bb86316 | 2034 | WARN_ON(btrfs_header_generation(mid) != trans->transid); |
e66f709b | 2035 | |
a05a9bb1 | 2036 | if (level < BTRFS_MAX_LEVEL - 1) { |
5f39d397 | 2037 | parent = path->nodes[level + 1]; |
a05a9bb1 LZ |
2038 | pslot = path->slots[level + 1]; |
2039 | } | |
e66f709b | 2040 | |
5f39d397 | 2041 | if (!parent) |
e66f709b | 2042 | return 1; |
e66f709b | 2043 | |
2ff7e61e | 2044 | left = read_node_slot(fs_info, parent, pslot - 1); |
fb770ae4 LB |
2045 | if (IS_ERR(left)) |
2046 | left = NULL; | |
e66f709b CM |
2047 | |
2048 | /* first, try to make some room in the middle buffer */ | |
5f39d397 | 2049 | if (left) { |
e66f709b | 2050 | u32 left_nr; |
925baedd CM |
2051 | |
2052 | btrfs_tree_lock(left); | |
b4ce94de CM |
2053 | btrfs_set_lock_blocking(left); |
2054 | ||
5f39d397 | 2055 | left_nr = btrfs_header_nritems(left); |
0b246afa | 2056 | if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(fs_info) - 1) { |
33ade1f8 CM |
2057 | wret = 1; |
2058 | } else { | |
5f39d397 | 2059 | ret = btrfs_cow_block(trans, root, left, parent, |
9fa8cfe7 | 2060 | pslot - 1, &left); |
54aa1f4d CM |
2061 | if (ret) |
2062 | wret = 1; | |
2063 | else { | |
2ff7e61e | 2064 | wret = push_node_left(trans, fs_info, |
971a1f66 | 2065 | left, mid, 0); |
54aa1f4d | 2066 | } |
33ade1f8 | 2067 | } |
e66f709b CM |
2068 | if (wret < 0) |
2069 | ret = wret; | |
2070 | if (wret == 0) { | |
5f39d397 | 2071 | struct btrfs_disk_key disk_key; |
e66f709b | 2072 | orig_slot += left_nr; |
5f39d397 | 2073 | btrfs_node_key(mid, &disk_key, 0); |
0e82bcfe DS |
2074 | ret = tree_mod_log_insert_key(parent, pslot, |
2075 | MOD_LOG_KEY_REPLACE, GFP_NOFS); | |
2076 | BUG_ON(ret < 0); | |
5f39d397 CM |
2077 | btrfs_set_node_key(parent, &disk_key, pslot); |
2078 | btrfs_mark_buffer_dirty(parent); | |
2079 | if (btrfs_header_nritems(left) > orig_slot) { | |
2080 | path->nodes[level] = left; | |
e66f709b CM |
2081 | path->slots[level + 1] -= 1; |
2082 | path->slots[level] = orig_slot; | |
925baedd | 2083 | btrfs_tree_unlock(mid); |
5f39d397 | 2084 | free_extent_buffer(mid); |
e66f709b CM |
2085 | } else { |
2086 | orig_slot -= | |
5f39d397 | 2087 | btrfs_header_nritems(left); |
e66f709b | 2088 | path->slots[level] = orig_slot; |
925baedd | 2089 | btrfs_tree_unlock(left); |
5f39d397 | 2090 | free_extent_buffer(left); |
e66f709b | 2091 | } |
e66f709b CM |
2092 | return 0; |
2093 | } | |
925baedd | 2094 | btrfs_tree_unlock(left); |
5f39d397 | 2095 | free_extent_buffer(left); |
e66f709b | 2096 | } |
2ff7e61e | 2097 | right = read_node_slot(fs_info, parent, pslot + 1); |
fb770ae4 LB |
2098 | if (IS_ERR(right)) |
2099 | right = NULL; | |
e66f709b CM |
2100 | |
2101 | /* | |
2102 | * then try to empty the right most buffer into the middle | |
2103 | */ | |
5f39d397 | 2104 | if (right) { |
33ade1f8 | 2105 | u32 right_nr; |
b4ce94de | 2106 | |
925baedd | 2107 | btrfs_tree_lock(right); |
b4ce94de CM |
2108 | btrfs_set_lock_blocking(right); |
2109 | ||
5f39d397 | 2110 | right_nr = btrfs_header_nritems(right); |
0b246afa | 2111 | if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(fs_info) - 1) { |
33ade1f8 CM |
2112 | wret = 1; |
2113 | } else { | |
5f39d397 CM |
2114 | ret = btrfs_cow_block(trans, root, right, |
2115 | parent, pslot + 1, | |
9fa8cfe7 | 2116 | &right); |
54aa1f4d CM |
2117 | if (ret) |
2118 | wret = 1; | |
2119 | else { | |
2ff7e61e | 2120 | wret = balance_node_right(trans, fs_info, |
5f39d397 | 2121 | right, mid); |
54aa1f4d | 2122 | } |
33ade1f8 | 2123 | } |
e66f709b CM |
2124 | if (wret < 0) |
2125 | ret = wret; | |
2126 | if (wret == 0) { | |
5f39d397 CM |
2127 | struct btrfs_disk_key disk_key; |
2128 | ||
2129 | btrfs_node_key(right, &disk_key, 0); | |
0e82bcfe DS |
2130 | ret = tree_mod_log_insert_key(parent, pslot + 1, |
2131 | MOD_LOG_KEY_REPLACE, GFP_NOFS); | |
2132 | BUG_ON(ret < 0); | |
5f39d397 CM |
2133 | btrfs_set_node_key(parent, &disk_key, pslot + 1); |
2134 | btrfs_mark_buffer_dirty(parent); | |
2135 | ||
2136 | if (btrfs_header_nritems(mid) <= orig_slot) { | |
2137 | path->nodes[level] = right; | |
e66f709b CM |
2138 | path->slots[level + 1] += 1; |
2139 | path->slots[level] = orig_slot - | |
5f39d397 | 2140 | btrfs_header_nritems(mid); |
925baedd | 2141 | btrfs_tree_unlock(mid); |
5f39d397 | 2142 | free_extent_buffer(mid); |
e66f709b | 2143 | } else { |
925baedd | 2144 | btrfs_tree_unlock(right); |
5f39d397 | 2145 | free_extent_buffer(right); |
e66f709b | 2146 | } |
e66f709b CM |
2147 | return 0; |
2148 | } | |
925baedd | 2149 | btrfs_tree_unlock(right); |
5f39d397 | 2150 | free_extent_buffer(right); |
e66f709b | 2151 | } |
e66f709b CM |
2152 | return 1; |
2153 | } | |
2154 | ||
3c69faec | 2155 | /* |
d352ac68 CM |
2156 | * readahead one full node of leaves, finding things that are close |
2157 | * to the block in 'slot', and triggering ra on them. | |
3c69faec | 2158 | */ |
2ff7e61e | 2159 | static void reada_for_search(struct btrfs_fs_info *fs_info, |
c8c42864 CM |
2160 | struct btrfs_path *path, |
2161 | int level, int slot, u64 objectid) | |
3c69faec | 2162 | { |
5f39d397 | 2163 | struct extent_buffer *node; |
01f46658 | 2164 | struct btrfs_disk_key disk_key; |
3c69faec | 2165 | u32 nritems; |
3c69faec | 2166 | u64 search; |
a7175319 | 2167 | u64 target; |
6b80053d | 2168 | u64 nread = 0; |
5f39d397 | 2169 | struct extent_buffer *eb; |
6b80053d CM |
2170 | u32 nr; |
2171 | u32 blocksize; | |
2172 | u32 nscan = 0; | |
db94535d | 2173 | |
a6b6e75e | 2174 | if (level != 1) |
6702ed49 CM |
2175 | return; |
2176 | ||
2177 | if (!path->nodes[level]) | |
3c69faec CM |
2178 | return; |
2179 | ||
5f39d397 | 2180 | node = path->nodes[level]; |
925baedd | 2181 | |
3c69faec | 2182 | search = btrfs_node_blockptr(node, slot); |
0b246afa JM |
2183 | blocksize = fs_info->nodesize; |
2184 | eb = find_extent_buffer(fs_info, search); | |
5f39d397 CM |
2185 | if (eb) { |
2186 | free_extent_buffer(eb); | |
3c69faec CM |
2187 | return; |
2188 | } | |
2189 | ||
a7175319 | 2190 | target = search; |
6b80053d | 2191 | |
5f39d397 | 2192 | nritems = btrfs_header_nritems(node); |
6b80053d | 2193 | nr = slot; |
25b8b936 | 2194 | |
d397712b | 2195 | while (1) { |
e4058b54 | 2196 | if (path->reada == READA_BACK) { |
6b80053d CM |
2197 | if (nr == 0) |
2198 | break; | |
2199 | nr--; | |
e4058b54 | 2200 | } else if (path->reada == READA_FORWARD) { |
6b80053d CM |
2201 | nr++; |
2202 | if (nr >= nritems) | |
2203 | break; | |
3c69faec | 2204 | } |
e4058b54 | 2205 | if (path->reada == READA_BACK && objectid) { |
01f46658 CM |
2206 | btrfs_node_key(node, &disk_key, nr); |
2207 | if (btrfs_disk_key_objectid(&disk_key) != objectid) | |
2208 | break; | |
2209 | } | |
6b80053d | 2210 | search = btrfs_node_blockptr(node, nr); |
a7175319 CM |
2211 | if ((search <= target && target - search <= 65536) || |
2212 | (search > target && search - target <= 65536)) { | |
2ff7e61e | 2213 | readahead_tree_block(fs_info, search); |
6b80053d CM |
2214 | nread += blocksize; |
2215 | } | |
2216 | nscan++; | |
a7175319 | 2217 | if ((nread > 65536 || nscan > 32)) |
6b80053d | 2218 | break; |
3c69faec CM |
2219 | } |
2220 | } | |
925baedd | 2221 | |
2ff7e61e | 2222 | static noinline void reada_for_balance(struct btrfs_fs_info *fs_info, |
0b08851f | 2223 | struct btrfs_path *path, int level) |
b4ce94de CM |
2224 | { |
2225 | int slot; | |
2226 | int nritems; | |
2227 | struct extent_buffer *parent; | |
2228 | struct extent_buffer *eb; | |
2229 | u64 gen; | |
2230 | u64 block1 = 0; | |
2231 | u64 block2 = 0; | |
b4ce94de | 2232 | |
8c594ea8 | 2233 | parent = path->nodes[level + 1]; |
b4ce94de | 2234 | if (!parent) |
0b08851f | 2235 | return; |
b4ce94de CM |
2236 | |
2237 | nritems = btrfs_header_nritems(parent); | |
8c594ea8 | 2238 | slot = path->slots[level + 1]; |
b4ce94de CM |
2239 | |
2240 | if (slot > 0) { | |
2241 | block1 = btrfs_node_blockptr(parent, slot - 1); | |
2242 | gen = btrfs_node_ptr_generation(parent, slot - 1); | |
0b246afa | 2243 | eb = find_extent_buffer(fs_info, block1); |
b9fab919 CM |
2244 | /* |
2245 | * if we get -eagain from btrfs_buffer_uptodate, we | |
2246 | * don't want to return eagain here. That will loop | |
2247 | * forever | |
2248 | */ | |
2249 | if (eb && btrfs_buffer_uptodate(eb, gen, 1) != 0) | |
b4ce94de CM |
2250 | block1 = 0; |
2251 | free_extent_buffer(eb); | |
2252 | } | |
8c594ea8 | 2253 | if (slot + 1 < nritems) { |
b4ce94de CM |
2254 | block2 = btrfs_node_blockptr(parent, slot + 1); |
2255 | gen = btrfs_node_ptr_generation(parent, slot + 1); | |
0b246afa | 2256 | eb = find_extent_buffer(fs_info, block2); |
b9fab919 | 2257 | if (eb && btrfs_buffer_uptodate(eb, gen, 1) != 0) |
b4ce94de CM |
2258 | block2 = 0; |
2259 | free_extent_buffer(eb); | |
2260 | } | |
8c594ea8 | 2261 | |
0b08851f | 2262 | if (block1) |
2ff7e61e | 2263 | readahead_tree_block(fs_info, block1); |
0b08851f | 2264 | if (block2) |
2ff7e61e | 2265 | readahead_tree_block(fs_info, block2); |
b4ce94de CM |
2266 | } |
2267 | ||
2268 | ||
d352ac68 | 2269 | /* |
d397712b CM |
2270 | * when we walk down the tree, it is usually safe to unlock the higher layers |
2271 | * in the tree. The exceptions are when our path goes through slot 0, because | |
2272 | * operations on the tree might require changing key pointers higher up in the | |
2273 | * tree. | |
d352ac68 | 2274 | * |
d397712b CM |
2275 | * callers might also have set path->keep_locks, which tells this code to keep |
2276 | * the lock if the path points to the last slot in the block. This is part of | |
2277 | * walking through the tree, and selecting the next slot in the higher block. | |
d352ac68 | 2278 | * |
d397712b CM |
2279 | * lowest_unlock sets the lowest level in the tree we're allowed to unlock. so |
2280 | * if lowest_unlock is 1, level 0 won't be unlocked | |
d352ac68 | 2281 | */ |
e02119d5 | 2282 | static noinline void unlock_up(struct btrfs_path *path, int level, |
f7c79f30 CM |
2283 | int lowest_unlock, int min_write_lock_level, |
2284 | int *write_lock_level) | |
925baedd CM |
2285 | { |
2286 | int i; | |
2287 | int skip_level = level; | |
051e1b9f | 2288 | int no_skips = 0; |
925baedd CM |
2289 | struct extent_buffer *t; |
2290 | ||
2291 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { | |
2292 | if (!path->nodes[i]) | |
2293 | break; | |
2294 | if (!path->locks[i]) | |
2295 | break; | |
051e1b9f | 2296 | if (!no_skips && path->slots[i] == 0) { |
925baedd CM |
2297 | skip_level = i + 1; |
2298 | continue; | |
2299 | } | |
051e1b9f | 2300 | if (!no_skips && path->keep_locks) { |
925baedd CM |
2301 | u32 nritems; |
2302 | t = path->nodes[i]; | |
2303 | nritems = btrfs_header_nritems(t); | |
051e1b9f | 2304 | if (nritems < 1 || path->slots[i] >= nritems - 1) { |
925baedd CM |
2305 | skip_level = i + 1; |
2306 | continue; | |
2307 | } | |
2308 | } | |
051e1b9f CM |
2309 | if (skip_level < i && i >= lowest_unlock) |
2310 | no_skips = 1; | |
2311 | ||
925baedd | 2312 | t = path->nodes[i]; |
d80bb3f9 | 2313 | if (i >= lowest_unlock && i > skip_level) { |
bd681513 | 2314 | btrfs_tree_unlock_rw(t, path->locks[i]); |
925baedd | 2315 | path->locks[i] = 0; |
f7c79f30 CM |
2316 | if (write_lock_level && |
2317 | i > min_write_lock_level && | |
2318 | i <= *write_lock_level) { | |
2319 | *write_lock_level = i - 1; | |
2320 | } | |
925baedd CM |
2321 | } |
2322 | } | |
2323 | } | |
2324 | ||
b4ce94de CM |
2325 | /* |
2326 | * This releases any locks held in the path starting at level and | |
2327 | * going all the way up to the root. | |
2328 | * | |
2329 | * btrfs_search_slot will keep the lock held on higher nodes in a few | |
2330 | * corner cases, such as COW of the block at slot zero in the node. This | |
2331 | * ignores those rules, and it should only be called when there are no | |
2332 | * more updates to be done higher up in the tree. | |
2333 | */ | |
2334 | noinline void btrfs_unlock_up_safe(struct btrfs_path *path, int level) | |
2335 | { | |
2336 | int i; | |
2337 | ||
09a2a8f9 | 2338 | if (path->keep_locks) |
b4ce94de CM |
2339 | return; |
2340 | ||
2341 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { | |
2342 | if (!path->nodes[i]) | |
12f4dacc | 2343 | continue; |
b4ce94de | 2344 | if (!path->locks[i]) |
12f4dacc | 2345 | continue; |
bd681513 | 2346 | btrfs_tree_unlock_rw(path->nodes[i], path->locks[i]); |
b4ce94de CM |
2347 | path->locks[i] = 0; |
2348 | } | |
2349 | } | |
2350 | ||
c8c42864 CM |
2351 | /* |
2352 | * helper function for btrfs_search_slot. The goal is to find a block | |
2353 | * in cache without setting the path to blocking. If we find the block | |
2354 | * we return zero and the path is unchanged. | |
2355 | * | |
2356 | * If we can't find the block, we set the path blocking and do some | |
2357 | * reada. -EAGAIN is returned and the search must be repeated. | |
2358 | */ | |
2359 | static int | |
d07b8528 LB |
2360 | read_block_for_search(struct btrfs_root *root, struct btrfs_path *p, |
2361 | struct extent_buffer **eb_ret, int level, int slot, | |
cda79c54 | 2362 | const struct btrfs_key *key) |
c8c42864 | 2363 | { |
0b246afa | 2364 | struct btrfs_fs_info *fs_info = root->fs_info; |
c8c42864 CM |
2365 | u64 blocknr; |
2366 | u64 gen; | |
c8c42864 CM |
2367 | struct extent_buffer *b = *eb_ret; |
2368 | struct extent_buffer *tmp; | |
581c1760 | 2369 | struct btrfs_key first_key; |
76a05b35 | 2370 | int ret; |
581c1760 | 2371 | int parent_level; |
c8c42864 CM |
2372 | |
2373 | blocknr = btrfs_node_blockptr(b, slot); | |
2374 | gen = btrfs_node_ptr_generation(b, slot); | |
581c1760 QW |
2375 | parent_level = btrfs_header_level(b); |
2376 | btrfs_node_key_to_cpu(b, &first_key, slot); | |
c8c42864 | 2377 | |
0b246afa | 2378 | tmp = find_extent_buffer(fs_info, blocknr); |
cb44921a | 2379 | if (tmp) { |
b9fab919 | 2380 | /* first we do an atomic uptodate check */ |
bdf7c00e JB |
2381 | if (btrfs_buffer_uptodate(tmp, gen, 1) > 0) { |
2382 | *eb_ret = tmp; | |
2383 | return 0; | |
2384 | } | |
2385 | ||
2386 | /* the pages were up to date, but we failed | |
2387 | * the generation number check. Do a full | |
2388 | * read for the generation number that is correct. | |
2389 | * We must do this without dropping locks so | |
2390 | * we can trust our generation number | |
2391 | */ | |
2392 | btrfs_set_path_blocking(p); | |
2393 | ||
2394 | /* now we're allowed to do a blocking uptodate check */ | |
581c1760 | 2395 | ret = btrfs_read_buffer(tmp, gen, parent_level - 1, &first_key); |
bdf7c00e JB |
2396 | if (!ret) { |
2397 | *eb_ret = tmp; | |
2398 | return 0; | |
cb44921a | 2399 | } |
bdf7c00e JB |
2400 | free_extent_buffer(tmp); |
2401 | btrfs_release_path(p); | |
2402 | return -EIO; | |
c8c42864 CM |
2403 | } |
2404 | ||
2405 | /* | |
2406 | * reduce lock contention at high levels | |
2407 | * of the btree by dropping locks before | |
76a05b35 CM |
2408 | * we read. Don't release the lock on the current |
2409 | * level because we need to walk this node to figure | |
2410 | * out which blocks to read. | |
c8c42864 | 2411 | */ |
8c594ea8 CM |
2412 | btrfs_unlock_up_safe(p, level + 1); |
2413 | btrfs_set_path_blocking(p); | |
2414 | ||
e4058b54 | 2415 | if (p->reada != READA_NONE) |
2ff7e61e | 2416 | reada_for_search(fs_info, p, level, slot, key->objectid); |
c8c42864 | 2417 | |
76a05b35 | 2418 | ret = -EAGAIN; |
02a3307a | 2419 | tmp = read_tree_block(fs_info, blocknr, gen, parent_level - 1, |
581c1760 | 2420 | &first_key); |
64c043de | 2421 | if (!IS_ERR(tmp)) { |
76a05b35 CM |
2422 | /* |
2423 | * If the read above didn't mark this buffer up to date, | |
2424 | * it will never end up being up to date. Set ret to EIO now | |
2425 | * and give up so that our caller doesn't loop forever | |
2426 | * on our EAGAINs. | |
2427 | */ | |
e6a1d6fd | 2428 | if (!extent_buffer_uptodate(tmp)) |
76a05b35 | 2429 | ret = -EIO; |
c8c42864 | 2430 | free_extent_buffer(tmp); |
c871b0f2 LB |
2431 | } else { |
2432 | ret = PTR_ERR(tmp); | |
76a05b35 | 2433 | } |
02a3307a LB |
2434 | |
2435 | btrfs_release_path(p); | |
76a05b35 | 2436 | return ret; |
c8c42864 CM |
2437 | } |
2438 | ||
2439 | /* | |
2440 | * helper function for btrfs_search_slot. This does all of the checks | |
2441 | * for node-level blocks and does any balancing required based on | |
2442 | * the ins_len. | |
2443 | * | |
2444 | * If no extra work was required, zero is returned. If we had to | |
2445 | * drop the path, -EAGAIN is returned and btrfs_search_slot must | |
2446 | * start over | |
2447 | */ | |
2448 | static int | |
2449 | setup_nodes_for_search(struct btrfs_trans_handle *trans, | |
2450 | struct btrfs_root *root, struct btrfs_path *p, | |
bd681513 CM |
2451 | struct extent_buffer *b, int level, int ins_len, |
2452 | int *write_lock_level) | |
c8c42864 | 2453 | { |
0b246afa | 2454 | struct btrfs_fs_info *fs_info = root->fs_info; |
c8c42864 | 2455 | int ret; |
0b246afa | 2456 | |
c8c42864 | 2457 | if ((p->search_for_split || ins_len > 0) && btrfs_header_nritems(b) >= |
0b246afa | 2458 | BTRFS_NODEPTRS_PER_BLOCK(fs_info) - 3) { |
c8c42864 CM |
2459 | int sret; |
2460 | ||
bd681513 CM |
2461 | if (*write_lock_level < level + 1) { |
2462 | *write_lock_level = level + 1; | |
2463 | btrfs_release_path(p); | |
2464 | goto again; | |
2465 | } | |
2466 | ||
c8c42864 | 2467 | btrfs_set_path_blocking(p); |
2ff7e61e | 2468 | reada_for_balance(fs_info, p, level); |
c8c42864 | 2469 | sret = split_node(trans, root, p, level); |
c8c42864 CM |
2470 | |
2471 | BUG_ON(sret > 0); | |
2472 | if (sret) { | |
2473 | ret = sret; | |
2474 | goto done; | |
2475 | } | |
2476 | b = p->nodes[level]; | |
2477 | } else if (ins_len < 0 && btrfs_header_nritems(b) < | |
0b246afa | 2478 | BTRFS_NODEPTRS_PER_BLOCK(fs_info) / 2) { |
c8c42864 CM |
2479 | int sret; |
2480 | ||
bd681513 CM |
2481 | if (*write_lock_level < level + 1) { |
2482 | *write_lock_level = level + 1; | |
2483 | btrfs_release_path(p); | |
2484 | goto again; | |
2485 | } | |
2486 | ||
c8c42864 | 2487 | btrfs_set_path_blocking(p); |
2ff7e61e | 2488 | reada_for_balance(fs_info, p, level); |
c8c42864 | 2489 | sret = balance_level(trans, root, p, level); |
c8c42864 CM |
2490 | |
2491 | if (sret) { | |
2492 | ret = sret; | |
2493 | goto done; | |
2494 | } | |
2495 | b = p->nodes[level]; | |
2496 | if (!b) { | |
b3b4aa74 | 2497 | btrfs_release_path(p); |
c8c42864 CM |
2498 | goto again; |
2499 | } | |
2500 | BUG_ON(btrfs_header_nritems(b) == 1); | |
2501 | } | |
2502 | return 0; | |
2503 | ||
2504 | again: | |
2505 | ret = -EAGAIN; | |
2506 | done: | |
2507 | return ret; | |
2508 | } | |
2509 | ||
d7396f07 | 2510 | static void key_search_validate(struct extent_buffer *b, |
310712b2 | 2511 | const struct btrfs_key *key, |
d7396f07 FDBM |
2512 | int level) |
2513 | { | |
2514 | #ifdef CONFIG_BTRFS_ASSERT | |
2515 | struct btrfs_disk_key disk_key; | |
2516 | ||
2517 | btrfs_cpu_key_to_disk(&disk_key, key); | |
2518 | ||
2519 | if (level == 0) | |
2520 | ASSERT(!memcmp_extent_buffer(b, &disk_key, | |
2521 | offsetof(struct btrfs_leaf, items[0].key), | |
2522 | sizeof(disk_key))); | |
2523 | else | |
2524 | ASSERT(!memcmp_extent_buffer(b, &disk_key, | |
2525 | offsetof(struct btrfs_node, ptrs[0].key), | |
2526 | sizeof(disk_key))); | |
2527 | #endif | |
2528 | } | |
2529 | ||
310712b2 | 2530 | static int key_search(struct extent_buffer *b, const struct btrfs_key *key, |
d7396f07 FDBM |
2531 | int level, int *prev_cmp, int *slot) |
2532 | { | |
2533 | if (*prev_cmp != 0) { | |
a74b35ec | 2534 | *prev_cmp = btrfs_bin_search(b, key, level, slot); |
d7396f07 FDBM |
2535 | return *prev_cmp; |
2536 | } | |
2537 | ||
2538 | key_search_validate(b, key, level); | |
2539 | *slot = 0; | |
2540 | ||
2541 | return 0; | |
2542 | } | |
2543 | ||
381cf658 | 2544 | int btrfs_find_item(struct btrfs_root *fs_root, struct btrfs_path *path, |
e33d5c3d KN |
2545 | u64 iobjectid, u64 ioff, u8 key_type, |
2546 | struct btrfs_key *found_key) | |
2547 | { | |
2548 | int ret; | |
2549 | struct btrfs_key key; | |
2550 | struct extent_buffer *eb; | |
381cf658 DS |
2551 | |
2552 | ASSERT(path); | |
1d4c08e0 | 2553 | ASSERT(found_key); |
e33d5c3d KN |
2554 | |
2555 | key.type = key_type; | |
2556 | key.objectid = iobjectid; | |
2557 | key.offset = ioff; | |
2558 | ||
2559 | ret = btrfs_search_slot(NULL, fs_root, &key, path, 0, 0); | |
1d4c08e0 | 2560 | if (ret < 0) |
e33d5c3d KN |
2561 | return ret; |
2562 | ||
2563 | eb = path->nodes[0]; | |
2564 | if (ret && path->slots[0] >= btrfs_header_nritems(eb)) { | |
2565 | ret = btrfs_next_leaf(fs_root, path); | |
2566 | if (ret) | |
2567 | return ret; | |
2568 | eb = path->nodes[0]; | |
2569 | } | |
2570 | ||
2571 | btrfs_item_key_to_cpu(eb, found_key, path->slots[0]); | |
2572 | if (found_key->type != key.type || | |
2573 | found_key->objectid != key.objectid) | |
2574 | return 1; | |
2575 | ||
2576 | return 0; | |
2577 | } | |
2578 | ||
1fc28d8e LB |
2579 | static struct extent_buffer *btrfs_search_slot_get_root(struct btrfs_root *root, |
2580 | struct btrfs_path *p, | |
2581 | int write_lock_level) | |
2582 | { | |
2583 | struct btrfs_fs_info *fs_info = root->fs_info; | |
2584 | struct extent_buffer *b; | |
2585 | int root_lock; | |
2586 | int level = 0; | |
2587 | ||
2588 | /* We try very hard to do read locks on the root */ | |
2589 | root_lock = BTRFS_READ_LOCK; | |
2590 | ||
2591 | if (p->search_commit_root) { | |
be6821f8 FM |
2592 | /* |
2593 | * The commit roots are read only so we always do read locks, | |
2594 | * and we always must hold the commit_root_sem when doing | |
2595 | * searches on them, the only exception is send where we don't | |
2596 | * want to block transaction commits for a long time, so | |
2597 | * we need to clone the commit root in order to avoid races | |
2598 | * with transaction commits that create a snapshot of one of | |
2599 | * the roots used by a send operation. | |
2600 | */ | |
2601 | if (p->need_commit_sem) { | |
1fc28d8e | 2602 | down_read(&fs_info->commit_root_sem); |
be6821f8 | 2603 | b = btrfs_clone_extent_buffer(root->commit_root); |
1fc28d8e | 2604 | up_read(&fs_info->commit_root_sem); |
be6821f8 FM |
2605 | if (!b) |
2606 | return ERR_PTR(-ENOMEM); | |
2607 | ||
2608 | } else { | |
2609 | b = root->commit_root; | |
2610 | extent_buffer_get(b); | |
2611 | } | |
2612 | level = btrfs_header_level(b); | |
f9ddfd05 LB |
2613 | /* |
2614 | * Ensure that all callers have set skip_locking when | |
2615 | * p->search_commit_root = 1. | |
2616 | */ | |
2617 | ASSERT(p->skip_locking == 1); | |
1fc28d8e LB |
2618 | |
2619 | goto out; | |
2620 | } | |
2621 | ||
2622 | if (p->skip_locking) { | |
2623 | b = btrfs_root_node(root); | |
2624 | level = btrfs_header_level(b); | |
2625 | goto out; | |
2626 | } | |
2627 | ||
2628 | /* | |
662c653b LB |
2629 | * If the level is set to maximum, we can skip trying to get the read |
2630 | * lock. | |
1fc28d8e | 2631 | */ |
662c653b LB |
2632 | if (write_lock_level < BTRFS_MAX_LEVEL) { |
2633 | /* | |
2634 | * We don't know the level of the root node until we actually | |
2635 | * have it read locked | |
2636 | */ | |
2637 | b = btrfs_read_lock_root_node(root); | |
2638 | level = btrfs_header_level(b); | |
2639 | if (level > write_lock_level) | |
2640 | goto out; | |
2641 | ||
2642 | /* Whoops, must trade for write lock */ | |
2643 | btrfs_tree_read_unlock(b); | |
2644 | free_extent_buffer(b); | |
2645 | } | |
1fc28d8e | 2646 | |
1fc28d8e LB |
2647 | b = btrfs_lock_root_node(root); |
2648 | root_lock = BTRFS_WRITE_LOCK; | |
2649 | ||
2650 | /* The level might have changed, check again */ | |
2651 | level = btrfs_header_level(b); | |
2652 | ||
2653 | out: | |
2654 | p->nodes[level] = b; | |
2655 | if (!p->skip_locking) | |
2656 | p->locks[level] = root_lock; | |
2657 | /* | |
2658 | * Callers are responsible for dropping b's references. | |
2659 | */ | |
2660 | return b; | |
2661 | } | |
2662 | ||
2663 | ||
74123bd7 | 2664 | /* |
4271ecea NB |
2665 | * btrfs_search_slot - look for a key in a tree and perform necessary |
2666 | * modifications to preserve tree invariants. | |
74123bd7 | 2667 | * |
4271ecea NB |
2668 | * @trans: Handle of transaction, used when modifying the tree |
2669 | * @p: Holds all btree nodes along the search path | |
2670 | * @root: The root node of the tree | |
2671 | * @key: The key we are looking for | |
2672 | * @ins_len: Indicates purpose of search, for inserts it is 1, for | |
2673 | * deletions it's -1. 0 for plain searches | |
2674 | * @cow: boolean should CoW operations be performed. Must always be 1 | |
2675 | * when modifying the tree. | |
97571fd0 | 2676 | * |
4271ecea NB |
2677 | * If @ins_len > 0, nodes and leaves will be split as we walk down the tree. |
2678 | * If @ins_len < 0, nodes will be merged as we walk down the tree (if possible) | |
2679 | * | |
2680 | * If @key is found, 0 is returned and you can find the item in the leaf level | |
2681 | * of the path (level 0) | |
2682 | * | |
2683 | * If @key isn't found, 1 is returned and the leaf level of the path (level 0) | |
2684 | * points to the slot where it should be inserted | |
2685 | * | |
2686 | * If an error is encountered while searching the tree a negative error number | |
2687 | * is returned | |
74123bd7 | 2688 | */ |
310712b2 OS |
2689 | int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
2690 | const struct btrfs_key *key, struct btrfs_path *p, | |
2691 | int ins_len, int cow) | |
be0e5c09 | 2692 | { |
0b246afa | 2693 | struct btrfs_fs_info *fs_info = root->fs_info; |
5f39d397 | 2694 | struct extent_buffer *b; |
be0e5c09 CM |
2695 | int slot; |
2696 | int ret; | |
33c66f43 | 2697 | int err; |
be0e5c09 | 2698 | int level; |
925baedd | 2699 | int lowest_unlock = 1; |
bd681513 CM |
2700 | /* everything at write_lock_level or lower must be write locked */ |
2701 | int write_lock_level = 0; | |
9f3a7427 | 2702 | u8 lowest_level = 0; |
f7c79f30 | 2703 | int min_write_lock_level; |
d7396f07 | 2704 | int prev_cmp; |
9f3a7427 | 2705 | |
6702ed49 | 2706 | lowest_level = p->lowest_level; |
323ac95b | 2707 | WARN_ON(lowest_level && ins_len > 0); |
22b0ebda | 2708 | WARN_ON(p->nodes[0] != NULL); |
eb653de1 | 2709 | BUG_ON(!cow && ins_len); |
25179201 | 2710 | |
bd681513 | 2711 | if (ins_len < 0) { |
925baedd | 2712 | lowest_unlock = 2; |
65b51a00 | 2713 | |
bd681513 CM |
2714 | /* when we are removing items, we might have to go up to level |
2715 | * two as we update tree pointers Make sure we keep write | |
2716 | * for those levels as well | |
2717 | */ | |
2718 | write_lock_level = 2; | |
2719 | } else if (ins_len > 0) { | |
2720 | /* | |
2721 | * for inserting items, make sure we have a write lock on | |
2722 | * level 1 so we can update keys | |
2723 | */ | |
2724 | write_lock_level = 1; | |
2725 | } | |
2726 | ||
2727 | if (!cow) | |
2728 | write_lock_level = -1; | |
2729 | ||
09a2a8f9 | 2730 | if (cow && (p->keep_locks || p->lowest_level)) |
bd681513 CM |
2731 | write_lock_level = BTRFS_MAX_LEVEL; |
2732 | ||
f7c79f30 CM |
2733 | min_write_lock_level = write_lock_level; |
2734 | ||
bb803951 | 2735 | again: |
d7396f07 | 2736 | prev_cmp = -1; |
1fc28d8e | 2737 | b = btrfs_search_slot_get_root(root, p, write_lock_level); |
be6821f8 FM |
2738 | if (IS_ERR(b)) { |
2739 | ret = PTR_ERR(b); | |
2740 | goto done; | |
2741 | } | |
925baedd | 2742 | |
eb60ceac | 2743 | while (b) { |
5f39d397 | 2744 | level = btrfs_header_level(b); |
65b51a00 CM |
2745 | |
2746 | /* | |
2747 | * setup the path here so we can release it under lock | |
2748 | * contention with the cow code | |
2749 | */ | |
02217ed2 | 2750 | if (cow) { |
9ea2c7c9 NB |
2751 | bool last_level = (level == (BTRFS_MAX_LEVEL - 1)); |
2752 | ||
c8c42864 CM |
2753 | /* |
2754 | * if we don't really need to cow this block | |
2755 | * then we don't want to set the path blocking, | |
2756 | * so we test it here | |
2757 | */ | |
64c12921 JM |
2758 | if (!should_cow_block(trans, root, b)) { |
2759 | trans->dirty = true; | |
65b51a00 | 2760 | goto cow_done; |
64c12921 | 2761 | } |
5d4f98a2 | 2762 | |
bd681513 CM |
2763 | /* |
2764 | * must have write locks on this node and the | |
2765 | * parent | |
2766 | */ | |
5124e00e JB |
2767 | if (level > write_lock_level || |
2768 | (level + 1 > write_lock_level && | |
2769 | level + 1 < BTRFS_MAX_LEVEL && | |
2770 | p->nodes[level + 1])) { | |
bd681513 CM |
2771 | write_lock_level = level + 1; |
2772 | btrfs_release_path(p); | |
2773 | goto again; | |
2774 | } | |
2775 | ||
160f4089 | 2776 | btrfs_set_path_blocking(p); |
9ea2c7c9 NB |
2777 | if (last_level) |
2778 | err = btrfs_cow_block(trans, root, b, NULL, 0, | |
2779 | &b); | |
2780 | else | |
2781 | err = btrfs_cow_block(trans, root, b, | |
2782 | p->nodes[level + 1], | |
2783 | p->slots[level + 1], &b); | |
33c66f43 | 2784 | if (err) { |
33c66f43 | 2785 | ret = err; |
65b51a00 | 2786 | goto done; |
54aa1f4d | 2787 | } |
02217ed2 | 2788 | } |
65b51a00 | 2789 | cow_done: |
eb60ceac | 2790 | p->nodes[level] = b; |
52398340 LB |
2791 | /* |
2792 | * Leave path with blocking locks to avoid massive | |
2793 | * lock context switch, this is made on purpose. | |
2794 | */ | |
b4ce94de CM |
2795 | |
2796 | /* | |
2797 | * we have a lock on b and as long as we aren't changing | |
2798 | * the tree, there is no way to for the items in b to change. | |
2799 | * It is safe to drop the lock on our parent before we | |
2800 | * go through the expensive btree search on b. | |
2801 | * | |
eb653de1 FDBM |
2802 | * If we're inserting or deleting (ins_len != 0), then we might |
2803 | * be changing slot zero, which may require changing the parent. | |
2804 | * So, we can't drop the lock until after we know which slot | |
2805 | * we're operating on. | |
b4ce94de | 2806 | */ |
eb653de1 FDBM |
2807 | if (!ins_len && !p->keep_locks) { |
2808 | int u = level + 1; | |
2809 | ||
2810 | if (u < BTRFS_MAX_LEVEL && p->locks[u]) { | |
2811 | btrfs_tree_unlock_rw(p->nodes[u], p->locks[u]); | |
2812 | p->locks[u] = 0; | |
2813 | } | |
2814 | } | |
b4ce94de | 2815 | |
d7396f07 | 2816 | ret = key_search(b, key, level, &prev_cmp, &slot); |
415b35a5 LB |
2817 | if (ret < 0) |
2818 | goto done; | |
b4ce94de | 2819 | |
5f39d397 | 2820 | if (level != 0) { |
33c66f43 YZ |
2821 | int dec = 0; |
2822 | if (ret && slot > 0) { | |
2823 | dec = 1; | |
be0e5c09 | 2824 | slot -= 1; |
33c66f43 | 2825 | } |
be0e5c09 | 2826 | p->slots[level] = slot; |
33c66f43 | 2827 | err = setup_nodes_for_search(trans, root, p, b, level, |
bd681513 | 2828 | ins_len, &write_lock_level); |
33c66f43 | 2829 | if (err == -EAGAIN) |
c8c42864 | 2830 | goto again; |
33c66f43 YZ |
2831 | if (err) { |
2832 | ret = err; | |
c8c42864 | 2833 | goto done; |
33c66f43 | 2834 | } |
c8c42864 CM |
2835 | b = p->nodes[level]; |
2836 | slot = p->slots[level]; | |
b4ce94de | 2837 | |
bd681513 CM |
2838 | /* |
2839 | * slot 0 is special, if we change the key | |
2840 | * we have to update the parent pointer | |
2841 | * which means we must have a write lock | |
2842 | * on the parent | |
2843 | */ | |
eb653de1 | 2844 | if (slot == 0 && ins_len && |
bd681513 CM |
2845 | write_lock_level < level + 1) { |
2846 | write_lock_level = level + 1; | |
2847 | btrfs_release_path(p); | |
2848 | goto again; | |
2849 | } | |
2850 | ||
f7c79f30 CM |
2851 | unlock_up(p, level, lowest_unlock, |
2852 | min_write_lock_level, &write_lock_level); | |
f9efa9c7 | 2853 | |
925baedd | 2854 | if (level == lowest_level) { |
33c66f43 YZ |
2855 | if (dec) |
2856 | p->slots[level]++; | |
5b21f2ed | 2857 | goto done; |
925baedd | 2858 | } |
ca7a79ad | 2859 | |
d07b8528 | 2860 | err = read_block_for_search(root, p, &b, level, |
cda79c54 | 2861 | slot, key); |
33c66f43 | 2862 | if (err == -EAGAIN) |
c8c42864 | 2863 | goto again; |
33c66f43 YZ |
2864 | if (err) { |
2865 | ret = err; | |
76a05b35 | 2866 | goto done; |
33c66f43 | 2867 | } |
76a05b35 | 2868 | |
b4ce94de | 2869 | if (!p->skip_locking) { |
bd681513 CM |
2870 | level = btrfs_header_level(b); |
2871 | if (level <= write_lock_level) { | |
2872 | err = btrfs_try_tree_write_lock(b); | |
2873 | if (!err) { | |
2874 | btrfs_set_path_blocking(p); | |
2875 | btrfs_tree_lock(b); | |
bd681513 CM |
2876 | } |
2877 | p->locks[level] = BTRFS_WRITE_LOCK; | |
2878 | } else { | |
f82c458a | 2879 | err = btrfs_tree_read_lock_atomic(b); |
bd681513 CM |
2880 | if (!err) { |
2881 | btrfs_set_path_blocking(p); | |
2882 | btrfs_tree_read_lock(b); | |
bd681513 CM |
2883 | } |
2884 | p->locks[level] = BTRFS_READ_LOCK; | |
b4ce94de | 2885 | } |
bd681513 | 2886 | p->nodes[level] = b; |
b4ce94de | 2887 | } |
be0e5c09 CM |
2888 | } else { |
2889 | p->slots[level] = slot; | |
87b29b20 | 2890 | if (ins_len > 0 && |
2ff7e61e | 2891 | btrfs_leaf_free_space(fs_info, b) < ins_len) { |
bd681513 CM |
2892 | if (write_lock_level < 1) { |
2893 | write_lock_level = 1; | |
2894 | btrfs_release_path(p); | |
2895 | goto again; | |
2896 | } | |
2897 | ||
b4ce94de | 2898 | btrfs_set_path_blocking(p); |
33c66f43 YZ |
2899 | err = split_leaf(trans, root, key, |
2900 | p, ins_len, ret == 0); | |
b4ce94de | 2901 | |
33c66f43 YZ |
2902 | BUG_ON(err > 0); |
2903 | if (err) { | |
2904 | ret = err; | |
65b51a00 CM |
2905 | goto done; |
2906 | } | |
5c680ed6 | 2907 | } |
459931ec | 2908 | if (!p->search_for_split) |
f7c79f30 | 2909 | unlock_up(p, level, lowest_unlock, |
4b6f8e96 | 2910 | min_write_lock_level, NULL); |
65b51a00 | 2911 | goto done; |
be0e5c09 CM |
2912 | } |
2913 | } | |
65b51a00 CM |
2914 | ret = 1; |
2915 | done: | |
b4ce94de CM |
2916 | /* |
2917 | * we don't really know what they plan on doing with the path | |
2918 | * from here on, so for now just mark it as blocking | |
2919 | */ | |
b9473439 CM |
2920 | if (!p->leave_spinning) |
2921 | btrfs_set_path_blocking(p); | |
5f5bc6b1 | 2922 | if (ret < 0 && !p->skip_release_on_error) |
b3b4aa74 | 2923 | btrfs_release_path(p); |
65b51a00 | 2924 | return ret; |
be0e5c09 CM |
2925 | } |
2926 | ||
5d9e75c4 JS |
2927 | /* |
2928 | * Like btrfs_search_slot, this looks for a key in the given tree. It uses the | |
2929 | * current state of the tree together with the operations recorded in the tree | |
2930 | * modification log to search for the key in a previous version of this tree, as | |
2931 | * denoted by the time_seq parameter. | |
2932 | * | |
2933 | * Naturally, there is no support for insert, delete or cow operations. | |
2934 | * | |
2935 | * The resulting path and return value will be set up as if we called | |
2936 | * btrfs_search_slot at that point in time with ins_len and cow both set to 0. | |
2937 | */ | |
310712b2 | 2938 | int btrfs_search_old_slot(struct btrfs_root *root, const struct btrfs_key *key, |
5d9e75c4 JS |
2939 | struct btrfs_path *p, u64 time_seq) |
2940 | { | |
0b246afa | 2941 | struct btrfs_fs_info *fs_info = root->fs_info; |
5d9e75c4 JS |
2942 | struct extent_buffer *b; |
2943 | int slot; | |
2944 | int ret; | |
2945 | int err; | |
2946 | int level; | |
2947 | int lowest_unlock = 1; | |
2948 | u8 lowest_level = 0; | |
d4b4087c | 2949 | int prev_cmp = -1; |
5d9e75c4 JS |
2950 | |
2951 | lowest_level = p->lowest_level; | |
2952 | WARN_ON(p->nodes[0] != NULL); | |
2953 | ||
2954 | if (p->search_commit_root) { | |
2955 | BUG_ON(time_seq); | |
2956 | return btrfs_search_slot(NULL, root, key, p, 0, 0); | |
2957 | } | |
2958 | ||
2959 | again: | |
5d9e75c4 | 2960 | b = get_old_root(root, time_seq); |
315bed43 NB |
2961 | if (!b) { |
2962 | ret = -EIO; | |
2963 | goto done; | |
2964 | } | |
5d9e75c4 | 2965 | level = btrfs_header_level(b); |
5d9e75c4 JS |
2966 | p->locks[level] = BTRFS_READ_LOCK; |
2967 | ||
2968 | while (b) { | |
2969 | level = btrfs_header_level(b); | |
2970 | p->nodes[level] = b; | |
5d9e75c4 JS |
2971 | |
2972 | /* | |
2973 | * we have a lock on b and as long as we aren't changing | |
2974 | * the tree, there is no way to for the items in b to change. | |
2975 | * It is safe to drop the lock on our parent before we | |
2976 | * go through the expensive btree search on b. | |
2977 | */ | |
2978 | btrfs_unlock_up_safe(p, level + 1); | |
2979 | ||
d4b4087c | 2980 | /* |
01327610 | 2981 | * Since we can unwind ebs we want to do a real search every |
d4b4087c JB |
2982 | * time. |
2983 | */ | |
2984 | prev_cmp = -1; | |
d7396f07 | 2985 | ret = key_search(b, key, level, &prev_cmp, &slot); |
5d9e75c4 JS |
2986 | |
2987 | if (level != 0) { | |
2988 | int dec = 0; | |
2989 | if (ret && slot > 0) { | |
2990 | dec = 1; | |
2991 | slot -= 1; | |
2992 | } | |
2993 | p->slots[level] = slot; | |
2994 | unlock_up(p, level, lowest_unlock, 0, NULL); | |
2995 | ||
2996 | if (level == lowest_level) { | |
2997 | if (dec) | |
2998 | p->slots[level]++; | |
2999 | goto done; | |
3000 | } | |
3001 | ||
d07b8528 | 3002 | err = read_block_for_search(root, p, &b, level, |
cda79c54 | 3003 | slot, key); |
5d9e75c4 JS |
3004 | if (err == -EAGAIN) |
3005 | goto again; | |
3006 | if (err) { | |
3007 | ret = err; | |
3008 | goto done; | |
3009 | } | |
3010 | ||
3011 | level = btrfs_header_level(b); | |
f82c458a | 3012 | err = btrfs_tree_read_lock_atomic(b); |
5d9e75c4 JS |
3013 | if (!err) { |
3014 | btrfs_set_path_blocking(p); | |
3015 | btrfs_tree_read_lock(b); | |
5d9e75c4 | 3016 | } |
0b246afa | 3017 | b = tree_mod_log_rewind(fs_info, p, b, time_seq); |
db7f3436 JB |
3018 | if (!b) { |
3019 | ret = -ENOMEM; | |
3020 | goto done; | |
3021 | } | |
5d9e75c4 JS |
3022 | p->locks[level] = BTRFS_READ_LOCK; |
3023 | p->nodes[level] = b; | |
5d9e75c4 JS |
3024 | } else { |
3025 | p->slots[level] = slot; | |
3026 | unlock_up(p, level, lowest_unlock, 0, NULL); | |
3027 | goto done; | |
3028 | } | |
3029 | } | |
3030 | ret = 1; | |
3031 | done: | |
3032 | if (!p->leave_spinning) | |
3033 | btrfs_set_path_blocking(p); | |
3034 | if (ret < 0) | |
3035 | btrfs_release_path(p); | |
3036 | ||
3037 | return ret; | |
3038 | } | |
3039 | ||
2f38b3e1 AJ |
3040 | /* |
3041 | * helper to use instead of search slot if no exact match is needed but | |
3042 | * instead the next or previous item should be returned. | |
3043 | * When find_higher is true, the next higher item is returned, the next lower | |
3044 | * otherwise. | |
3045 | * When return_any and find_higher are both true, and no higher item is found, | |
3046 | * return the next lower instead. | |
3047 | * When return_any is true and find_higher is false, and no lower item is found, | |
3048 | * return the next higher instead. | |
3049 | * It returns 0 if any item is found, 1 if none is found (tree empty), and | |
3050 | * < 0 on error | |
3051 | */ | |
3052 | int btrfs_search_slot_for_read(struct btrfs_root *root, | |
310712b2 OS |
3053 | const struct btrfs_key *key, |
3054 | struct btrfs_path *p, int find_higher, | |
3055 | int return_any) | |
2f38b3e1 AJ |
3056 | { |
3057 | int ret; | |
3058 | struct extent_buffer *leaf; | |
3059 | ||
3060 | again: | |
3061 | ret = btrfs_search_slot(NULL, root, key, p, 0, 0); | |
3062 | if (ret <= 0) | |
3063 | return ret; | |
3064 | /* | |
3065 | * a return value of 1 means the path is at the position where the | |
3066 | * item should be inserted. Normally this is the next bigger item, | |
3067 | * but in case the previous item is the last in a leaf, path points | |
3068 | * to the first free slot in the previous leaf, i.e. at an invalid | |
3069 | * item. | |
3070 | */ | |
3071 | leaf = p->nodes[0]; | |
3072 | ||
3073 | if (find_higher) { | |
3074 | if (p->slots[0] >= btrfs_header_nritems(leaf)) { | |
3075 | ret = btrfs_next_leaf(root, p); | |
3076 | if (ret <= 0) | |
3077 | return ret; | |
3078 | if (!return_any) | |
3079 | return 1; | |
3080 | /* | |
3081 | * no higher item found, return the next | |
3082 | * lower instead | |
3083 | */ | |
3084 | return_any = 0; | |
3085 | find_higher = 0; | |
3086 | btrfs_release_path(p); | |
3087 | goto again; | |
3088 | } | |
3089 | } else { | |
e6793769 AJ |
3090 | if (p->slots[0] == 0) { |
3091 | ret = btrfs_prev_leaf(root, p); | |
3092 | if (ret < 0) | |
3093 | return ret; | |
3094 | if (!ret) { | |
23c6bf6a FDBM |
3095 | leaf = p->nodes[0]; |
3096 | if (p->slots[0] == btrfs_header_nritems(leaf)) | |
3097 | p->slots[0]--; | |
e6793769 | 3098 | return 0; |
2f38b3e1 | 3099 | } |
e6793769 AJ |
3100 | if (!return_any) |
3101 | return 1; | |
3102 | /* | |
3103 | * no lower item found, return the next | |
3104 | * higher instead | |
3105 | */ | |
3106 | return_any = 0; | |
3107 | find_higher = 1; | |
3108 | btrfs_release_path(p); | |
3109 | goto again; | |
3110 | } else { | |
2f38b3e1 AJ |
3111 | --p->slots[0]; |
3112 | } | |
3113 | } | |
3114 | return 0; | |
3115 | } | |
3116 | ||
74123bd7 CM |
3117 | /* |
3118 | * adjust the pointers going up the tree, starting at level | |
3119 | * making sure the right key of each node is points to 'key'. | |
3120 | * This is used after shifting pointers to the left, so it stops | |
3121 | * fixing up pointers when a given leaf/node is not in slot 0 of the | |
3122 | * higher levels | |
aa5d6bed | 3123 | * |
74123bd7 | 3124 | */ |
b167fa91 | 3125 | static void fixup_low_keys(struct btrfs_path *path, |
143bede5 | 3126 | struct btrfs_disk_key *key, int level) |
be0e5c09 CM |
3127 | { |
3128 | int i; | |
5f39d397 | 3129 | struct extent_buffer *t; |
0e82bcfe | 3130 | int ret; |
5f39d397 | 3131 | |
234b63a0 | 3132 | for (i = level; i < BTRFS_MAX_LEVEL; i++) { |
be0e5c09 | 3133 | int tslot = path->slots[i]; |
0e82bcfe | 3134 | |
eb60ceac | 3135 | if (!path->nodes[i]) |
be0e5c09 | 3136 | break; |
5f39d397 | 3137 | t = path->nodes[i]; |
0e82bcfe DS |
3138 | ret = tree_mod_log_insert_key(t, tslot, MOD_LOG_KEY_REPLACE, |
3139 | GFP_ATOMIC); | |
3140 | BUG_ON(ret < 0); | |
5f39d397 | 3141 | btrfs_set_node_key(t, key, tslot); |
d6025579 | 3142 | btrfs_mark_buffer_dirty(path->nodes[i]); |
be0e5c09 CM |
3143 | if (tslot != 0) |
3144 | break; | |
3145 | } | |
3146 | } | |
3147 | ||
31840ae1 ZY |
3148 | /* |
3149 | * update item key. | |
3150 | * | |
3151 | * This function isn't completely safe. It's the caller's responsibility | |
3152 | * that the new key won't break the order | |
3153 | */ | |
b7a0365e DD |
3154 | void btrfs_set_item_key_safe(struct btrfs_fs_info *fs_info, |
3155 | struct btrfs_path *path, | |
310712b2 | 3156 | const struct btrfs_key *new_key) |
31840ae1 ZY |
3157 | { |
3158 | struct btrfs_disk_key disk_key; | |
3159 | struct extent_buffer *eb; | |
3160 | int slot; | |
3161 | ||
3162 | eb = path->nodes[0]; | |
3163 | slot = path->slots[0]; | |
3164 | if (slot > 0) { | |
3165 | btrfs_item_key(eb, &disk_key, slot - 1); | |
143bede5 | 3166 | BUG_ON(comp_keys(&disk_key, new_key) >= 0); |
31840ae1 ZY |
3167 | } |
3168 | if (slot < btrfs_header_nritems(eb) - 1) { | |
3169 | btrfs_item_key(eb, &disk_key, slot + 1); | |
143bede5 | 3170 | BUG_ON(comp_keys(&disk_key, new_key) <= 0); |
31840ae1 ZY |
3171 | } |
3172 | ||
3173 | btrfs_cpu_key_to_disk(&disk_key, new_key); | |
3174 | btrfs_set_item_key(eb, &disk_key, slot); | |
3175 | btrfs_mark_buffer_dirty(eb); | |
3176 | if (slot == 0) | |
b167fa91 | 3177 | fixup_low_keys(path, &disk_key, 1); |
31840ae1 ZY |
3178 | } |
3179 | ||
74123bd7 CM |
3180 | /* |
3181 | * try to push data from one node into the next node left in the | |
79f95c82 | 3182 | * tree. |
aa5d6bed CM |
3183 | * |
3184 | * returns 0 if some ptrs were pushed left, < 0 if there was some horrible | |
3185 | * error, and > 0 if there was no room in the left hand block. | |
74123bd7 | 3186 | */ |
98ed5174 | 3187 | static int push_node_left(struct btrfs_trans_handle *trans, |
2ff7e61e JM |
3188 | struct btrfs_fs_info *fs_info, |
3189 | struct extent_buffer *dst, | |
971a1f66 | 3190 | struct extent_buffer *src, int empty) |
be0e5c09 | 3191 | { |
be0e5c09 | 3192 | int push_items = 0; |
bb803951 CM |
3193 | int src_nritems; |
3194 | int dst_nritems; | |
aa5d6bed | 3195 | int ret = 0; |
be0e5c09 | 3196 | |
5f39d397 CM |
3197 | src_nritems = btrfs_header_nritems(src); |
3198 | dst_nritems = btrfs_header_nritems(dst); | |
0b246afa | 3199 | push_items = BTRFS_NODEPTRS_PER_BLOCK(fs_info) - dst_nritems; |
7bb86316 CM |
3200 | WARN_ON(btrfs_header_generation(src) != trans->transid); |
3201 | WARN_ON(btrfs_header_generation(dst) != trans->transid); | |
54aa1f4d | 3202 | |
bce4eae9 | 3203 | if (!empty && src_nritems <= 8) |
971a1f66 CM |
3204 | return 1; |
3205 | ||
d397712b | 3206 | if (push_items <= 0) |
be0e5c09 CM |
3207 | return 1; |
3208 | ||
bce4eae9 | 3209 | if (empty) { |
971a1f66 | 3210 | push_items = min(src_nritems, push_items); |
bce4eae9 CM |
3211 | if (push_items < src_nritems) { |
3212 | /* leave at least 8 pointers in the node if | |
3213 | * we aren't going to empty it | |
3214 | */ | |
3215 | if (src_nritems - push_items < 8) { | |
3216 | if (push_items <= 8) | |
3217 | return 1; | |
3218 | push_items -= 8; | |
3219 | } | |
3220 | } | |
3221 | } else | |
3222 | push_items = min(src_nritems - 8, push_items); | |
79f95c82 | 3223 | |
0b246afa | 3224 | ret = tree_mod_log_eb_copy(fs_info, dst, src, dst_nritems, 0, |
5de865ee FDBM |
3225 | push_items); |
3226 | if (ret) { | |
66642832 | 3227 | btrfs_abort_transaction(trans, ret); |
5de865ee FDBM |
3228 | return ret; |
3229 | } | |
5f39d397 CM |
3230 | copy_extent_buffer(dst, src, |
3231 | btrfs_node_key_ptr_offset(dst_nritems), | |
3232 | btrfs_node_key_ptr_offset(0), | |
d397712b | 3233 | push_items * sizeof(struct btrfs_key_ptr)); |
5f39d397 | 3234 | |
bb803951 | 3235 | if (push_items < src_nritems) { |
57911b8b | 3236 | /* |
bf1d3425 DS |
3237 | * Don't call tree_mod_log_insert_move here, key removal was |
3238 | * already fully logged by tree_mod_log_eb_copy above. | |
57911b8b | 3239 | */ |
5f39d397 CM |
3240 | memmove_extent_buffer(src, btrfs_node_key_ptr_offset(0), |
3241 | btrfs_node_key_ptr_offset(push_items), | |
3242 | (src_nritems - push_items) * | |
3243 | sizeof(struct btrfs_key_ptr)); | |
3244 | } | |
3245 | btrfs_set_header_nritems(src, src_nritems - push_items); | |
3246 | btrfs_set_header_nritems(dst, dst_nritems + push_items); | |
3247 | btrfs_mark_buffer_dirty(src); | |
3248 | btrfs_mark_buffer_dirty(dst); | |
31840ae1 | 3249 | |
79f95c82 CM |
3250 | return ret; |
3251 | } | |
3252 | ||
3253 | /* | |
3254 | * try to push data from one node into the next node right in the | |
3255 | * tree. | |
3256 | * | |
3257 | * returns 0 if some ptrs were pushed, < 0 if there was some horrible | |
3258 | * error, and > 0 if there was no room in the right hand block. | |
3259 | * | |
3260 | * this will only push up to 1/2 the contents of the left node over | |
3261 | */ | |
5f39d397 | 3262 | static int balance_node_right(struct btrfs_trans_handle *trans, |
2ff7e61e | 3263 | struct btrfs_fs_info *fs_info, |
5f39d397 CM |
3264 | struct extent_buffer *dst, |
3265 | struct extent_buffer *src) | |
79f95c82 | 3266 | { |
79f95c82 CM |
3267 | int push_items = 0; |
3268 | int max_push; | |
3269 | int src_nritems; | |
3270 | int dst_nritems; | |
3271 | int ret = 0; | |
79f95c82 | 3272 | |
7bb86316 CM |
3273 | WARN_ON(btrfs_header_generation(src) != trans->transid); |
3274 | WARN_ON(btrfs_header_generation(dst) != trans->transid); | |
3275 | ||
5f39d397 CM |
3276 | src_nritems = btrfs_header_nritems(src); |
3277 | dst_nritems = btrfs_header_nritems(dst); | |
0b246afa | 3278 | push_items = BTRFS_NODEPTRS_PER_BLOCK(fs_info) - dst_nritems; |
d397712b | 3279 | if (push_items <= 0) |
79f95c82 | 3280 | return 1; |
bce4eae9 | 3281 | |
d397712b | 3282 | if (src_nritems < 4) |
bce4eae9 | 3283 | return 1; |
79f95c82 CM |
3284 | |
3285 | max_push = src_nritems / 2 + 1; | |
3286 | /* don't try to empty the node */ | |
d397712b | 3287 | if (max_push >= src_nritems) |
79f95c82 | 3288 | return 1; |
252c38f0 | 3289 | |
79f95c82 CM |
3290 | if (max_push < push_items) |
3291 | push_items = max_push; | |
3292 | ||
bf1d3425 DS |
3293 | ret = tree_mod_log_insert_move(dst, push_items, 0, dst_nritems); |
3294 | BUG_ON(ret < 0); | |
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 | |
0b246afa | 3300 | ret = tree_mod_log_eb_copy(fs_info, dst, src, 0, |
5de865ee FDBM |
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 | { |
0b246afa | 3331 | struct btrfs_fs_info *fs_info = root->fs_info; |
7bb86316 | 3332 | u64 lower_gen; |
5f39d397 CM |
3333 | struct extent_buffer *lower; |
3334 | struct extent_buffer *c; | |
925baedd | 3335 | struct extent_buffer *old; |
5f39d397 | 3336 | struct btrfs_disk_key lower_key; |
d9d19a01 | 3337 | int ret; |
5c680ed6 CM |
3338 | |
3339 | BUG_ON(path->nodes[level]); | |
3340 | BUG_ON(path->nodes[level-1] != root->node); | |
3341 | ||
7bb86316 CM |
3342 | lower = path->nodes[level-1]; |
3343 | if (level == 1) | |
3344 | btrfs_item_key(lower, &lower_key, 0); | |
3345 | else | |
3346 | btrfs_node_key(lower, &lower_key, 0); | |
3347 | ||
4d75f8a9 DS |
3348 | c = btrfs_alloc_tree_block(trans, root, 0, root->root_key.objectid, |
3349 | &lower_key, level, root->node->start, 0); | |
5f39d397 CM |
3350 | if (IS_ERR(c)) |
3351 | return PTR_ERR(c); | |
925baedd | 3352 | |
0b246afa | 3353 | root_add_used(root, fs_info->nodesize); |
f0486c68 | 3354 | |
5f39d397 | 3355 | btrfs_set_header_nritems(c, 1); |
5f39d397 | 3356 | btrfs_set_node_key(c, &lower_key, 0); |
db94535d | 3357 | btrfs_set_node_blockptr(c, 0, lower->start); |
7bb86316 | 3358 | lower_gen = btrfs_header_generation(lower); |
31840ae1 | 3359 | WARN_ON(lower_gen != trans->transid); |
7bb86316 CM |
3360 | |
3361 | btrfs_set_node_ptr_generation(c, 0, lower_gen); | |
d5719762 | 3362 | |
5f39d397 | 3363 | btrfs_mark_buffer_dirty(c); |
d5719762 | 3364 | |
925baedd | 3365 | old = root->node; |
d9d19a01 DS |
3366 | ret = tree_mod_log_insert_root(root->node, c, 0); |
3367 | BUG_ON(ret < 0); | |
240f62c8 | 3368 | rcu_assign_pointer(root->node, c); |
925baedd CM |
3369 | |
3370 | /* the super has an extra ref to root->node */ | |
3371 | free_extent_buffer(old); | |
3372 | ||
0b86a832 | 3373 | add_root_to_dirty_list(root); |
5f39d397 CM |
3374 | extent_buffer_get(c); |
3375 | path->nodes[level] = c; | |
95449a16 | 3376 | path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING; |
5c680ed6 CM |
3377 | path->slots[level] = 0; |
3378 | return 0; | |
3379 | } | |
3380 | ||
74123bd7 CM |
3381 | /* |
3382 | * worker function to insert a single pointer in a node. | |
3383 | * the node should have enough room for the pointer already | |
97571fd0 | 3384 | * |
74123bd7 CM |
3385 | * slot and level indicate where you want the key to go, and |
3386 | * blocknr is the block the key points to. | |
3387 | */ | |
143bede5 | 3388 | static void insert_ptr(struct btrfs_trans_handle *trans, |
2ff7e61e | 3389 | struct btrfs_fs_info *fs_info, struct btrfs_path *path, |
143bede5 | 3390 | struct btrfs_disk_key *key, u64 bytenr, |
c3e06965 | 3391 | int slot, int level) |
74123bd7 | 3392 | { |
5f39d397 | 3393 | struct extent_buffer *lower; |
74123bd7 | 3394 | int nritems; |
f3ea38da | 3395 | int ret; |
5c680ed6 CM |
3396 | |
3397 | BUG_ON(!path->nodes[level]); | |
f0486c68 | 3398 | btrfs_assert_tree_locked(path->nodes[level]); |
5f39d397 CM |
3399 | lower = path->nodes[level]; |
3400 | nritems = btrfs_header_nritems(lower); | |
c293498b | 3401 | BUG_ON(slot > nritems); |
0b246afa | 3402 | BUG_ON(nritems == BTRFS_NODEPTRS_PER_BLOCK(fs_info)); |
74123bd7 | 3403 | if (slot != nritems) { |
bf1d3425 DS |
3404 | if (level) { |
3405 | ret = tree_mod_log_insert_move(lower, slot + 1, slot, | |
a446a979 | 3406 | nritems - slot); |
bf1d3425 DS |
3407 | BUG_ON(ret < 0); |
3408 | } | |
5f39d397 CM |
3409 | memmove_extent_buffer(lower, |
3410 | btrfs_node_key_ptr_offset(slot + 1), | |
3411 | btrfs_node_key_ptr_offset(slot), | |
d6025579 | 3412 | (nritems - slot) * sizeof(struct btrfs_key_ptr)); |
74123bd7 | 3413 | } |
c3e06965 | 3414 | if (level) { |
e09c2efe DS |
3415 | ret = tree_mod_log_insert_key(lower, slot, MOD_LOG_KEY_ADD, |
3416 | GFP_NOFS); | |
f3ea38da JS |
3417 | BUG_ON(ret < 0); |
3418 | } | |
5f39d397 | 3419 | btrfs_set_node_key(lower, key, slot); |
db94535d | 3420 | btrfs_set_node_blockptr(lower, slot, bytenr); |
74493f7a CM |
3421 | WARN_ON(trans->transid == 0); |
3422 | btrfs_set_node_ptr_generation(lower, slot, trans->transid); | |
5f39d397 CM |
3423 | btrfs_set_header_nritems(lower, nritems + 1); |
3424 | btrfs_mark_buffer_dirty(lower); | |
74123bd7 CM |
3425 | } |
3426 | ||
97571fd0 CM |
3427 | /* |
3428 | * split the node at the specified level in path in two. | |
3429 | * The path is corrected to point to the appropriate node after the split | |
3430 | * | |
3431 | * Before splitting this tries to make some room in the node by pushing | |
3432 | * left and right, if either one works, it returns right away. | |
aa5d6bed CM |
3433 | * |
3434 | * returns 0 on success and < 0 on failure | |
97571fd0 | 3435 | */ |
e02119d5 CM |
3436 | static noinline int split_node(struct btrfs_trans_handle *trans, |
3437 | struct btrfs_root *root, | |
3438 | struct btrfs_path *path, int level) | |
be0e5c09 | 3439 | { |
0b246afa | 3440 | struct btrfs_fs_info *fs_info = root->fs_info; |
5f39d397 CM |
3441 | struct extent_buffer *c; |
3442 | struct extent_buffer *split; | |
3443 | struct btrfs_disk_key disk_key; | |
be0e5c09 | 3444 | int mid; |
5c680ed6 | 3445 | int ret; |
7518a238 | 3446 | u32 c_nritems; |
eb60ceac | 3447 | |
5f39d397 | 3448 | c = path->nodes[level]; |
7bb86316 | 3449 | WARN_ON(btrfs_header_generation(c) != trans->transid); |
5f39d397 | 3450 | if (c == root->node) { |
d9abbf1c | 3451 | /* |
90f8d62e JS |
3452 | * trying to split the root, lets make a new one |
3453 | * | |
fdd99c72 | 3454 | * tree mod log: We don't log_removal old root in |
90f8d62e JS |
3455 | * insert_new_root, because that root buffer will be kept as a |
3456 | * normal node. We are going to log removal of half of the | |
3457 | * elements below with tree_mod_log_eb_copy. We're holding a | |
3458 | * tree lock on the buffer, which is why we cannot race with | |
3459 | * other tree_mod_log users. | |
d9abbf1c | 3460 | */ |
fdd99c72 | 3461 | ret = insert_new_root(trans, root, path, level + 1); |
5c680ed6 CM |
3462 | if (ret) |
3463 | return ret; | |
b3612421 | 3464 | } else { |
e66f709b | 3465 | ret = push_nodes_for_insert(trans, root, path, level); |
5f39d397 CM |
3466 | c = path->nodes[level]; |
3467 | if (!ret && btrfs_header_nritems(c) < | |
0b246afa | 3468 | BTRFS_NODEPTRS_PER_BLOCK(fs_info) - 3) |
e66f709b | 3469 | return 0; |
54aa1f4d CM |
3470 | if (ret < 0) |
3471 | return ret; | |
be0e5c09 | 3472 | } |
e66f709b | 3473 | |
5f39d397 | 3474 | c_nritems = btrfs_header_nritems(c); |
5d4f98a2 YZ |
3475 | mid = (c_nritems + 1) / 2; |
3476 | btrfs_node_key(c, &disk_key, mid); | |
7bb86316 | 3477 | |
4d75f8a9 DS |
3478 | split = btrfs_alloc_tree_block(trans, root, 0, root->root_key.objectid, |
3479 | &disk_key, level, c->start, 0); | |
5f39d397 CM |
3480 | if (IS_ERR(split)) |
3481 | return PTR_ERR(split); | |
3482 | ||
0b246afa | 3483 | root_add_used(root, fs_info->nodesize); |
bc877d28 | 3484 | ASSERT(btrfs_header_level(c) == level); |
54aa1f4d | 3485 | |
0b246afa | 3486 | ret = tree_mod_log_eb_copy(fs_info, split, c, 0, mid, c_nritems - mid); |
5de865ee | 3487 | if (ret) { |
66642832 | 3488 | btrfs_abort_transaction(trans, ret); |
5de865ee FDBM |
3489 | return ret; |
3490 | } | |
5f39d397 CM |
3491 | copy_extent_buffer(split, c, |
3492 | btrfs_node_key_ptr_offset(0), | |
3493 | btrfs_node_key_ptr_offset(mid), | |
3494 | (c_nritems - mid) * sizeof(struct btrfs_key_ptr)); | |
3495 | btrfs_set_header_nritems(split, c_nritems - mid); | |
3496 | btrfs_set_header_nritems(c, mid); | |
aa5d6bed CM |
3497 | ret = 0; |
3498 | ||
5f39d397 CM |
3499 | btrfs_mark_buffer_dirty(c); |
3500 | btrfs_mark_buffer_dirty(split); | |
3501 | ||
2ff7e61e | 3502 | insert_ptr(trans, fs_info, path, &disk_key, split->start, |
c3e06965 | 3503 | path->slots[level + 1] + 1, level + 1); |
aa5d6bed | 3504 | |
5de08d7d | 3505 | if (path->slots[level] >= mid) { |
5c680ed6 | 3506 | path->slots[level] -= mid; |
925baedd | 3507 | btrfs_tree_unlock(c); |
5f39d397 CM |
3508 | free_extent_buffer(c); |
3509 | path->nodes[level] = split; | |
5c680ed6 CM |
3510 | path->slots[level + 1] += 1; |
3511 | } else { | |
925baedd | 3512 | btrfs_tree_unlock(split); |
5f39d397 | 3513 | free_extent_buffer(split); |
be0e5c09 | 3514 | } |
aa5d6bed | 3515 | return ret; |
be0e5c09 CM |
3516 | } |
3517 | ||
74123bd7 CM |
3518 | /* |
3519 | * how many bytes are required to store the items in a leaf. start | |
3520 | * and nr indicate which items in the leaf to check. This totals up the | |
3521 | * space used both by the item structs and the item data | |
3522 | */ | |
5f39d397 | 3523 | static int leaf_space_used(struct extent_buffer *l, int start, int nr) |
be0e5c09 | 3524 | { |
41be1f3b JB |
3525 | struct btrfs_item *start_item; |
3526 | struct btrfs_item *end_item; | |
3527 | struct btrfs_map_token token; | |
be0e5c09 | 3528 | int data_len; |
5f39d397 | 3529 | int nritems = btrfs_header_nritems(l); |
d4dbff95 | 3530 | int end = min(nritems, start + nr) - 1; |
be0e5c09 CM |
3531 | |
3532 | if (!nr) | |
3533 | return 0; | |
41be1f3b | 3534 | btrfs_init_map_token(&token); |
dd3cc16b RK |
3535 | start_item = btrfs_item_nr(start); |
3536 | end_item = btrfs_item_nr(end); | |
41be1f3b JB |
3537 | data_len = btrfs_token_item_offset(l, start_item, &token) + |
3538 | btrfs_token_item_size(l, start_item, &token); | |
3539 | data_len = data_len - btrfs_token_item_offset(l, end_item, &token); | |
0783fcfc | 3540 | data_len += sizeof(struct btrfs_item) * nr; |
d4dbff95 | 3541 | WARN_ON(data_len < 0); |
be0e5c09 CM |
3542 | return data_len; |
3543 | } | |
3544 | ||
d4dbff95 CM |
3545 | /* |
3546 | * The space between the end of the leaf items and | |
3547 | * the start of the leaf data. IOW, how much room | |
3548 | * the leaf has left for both items and data | |
3549 | */ | |
2ff7e61e | 3550 | noinline int btrfs_leaf_free_space(struct btrfs_fs_info *fs_info, |
e02119d5 | 3551 | struct extent_buffer *leaf) |
d4dbff95 | 3552 | { |
5f39d397 CM |
3553 | int nritems = btrfs_header_nritems(leaf); |
3554 | int ret; | |
0b246afa JM |
3555 | |
3556 | ret = BTRFS_LEAF_DATA_SIZE(fs_info) - leaf_space_used(leaf, 0, nritems); | |
5f39d397 | 3557 | if (ret < 0) { |
0b246afa JM |
3558 | btrfs_crit(fs_info, |
3559 | "leaf free space ret %d, leaf data size %lu, used %d nritems %d", | |
3560 | ret, | |
3561 | (unsigned long) BTRFS_LEAF_DATA_SIZE(fs_info), | |
3562 | leaf_space_used(leaf, 0, nritems), nritems); | |
5f39d397 CM |
3563 | } |
3564 | return ret; | |
d4dbff95 CM |
3565 | } |
3566 | ||
99d8f83c CM |
3567 | /* |
3568 | * min slot controls the lowest index we're willing to push to the | |
3569 | * right. We'll push up to and including min_slot, but no lower | |
3570 | */ | |
1e47eef2 | 3571 | static noinline int __push_leaf_right(struct btrfs_fs_info *fs_info, |
44871b1b CM |
3572 | struct btrfs_path *path, |
3573 | int data_size, int empty, | |
3574 | struct extent_buffer *right, | |
99d8f83c CM |
3575 | int free_space, u32 left_nritems, |
3576 | u32 min_slot) | |
00ec4c51 | 3577 | { |
5f39d397 | 3578 | struct extent_buffer *left = path->nodes[0]; |
44871b1b | 3579 | struct extent_buffer *upper = path->nodes[1]; |
cfed81a0 | 3580 | struct btrfs_map_token token; |
5f39d397 | 3581 | struct btrfs_disk_key disk_key; |
00ec4c51 | 3582 | int slot; |
34a38218 | 3583 | u32 i; |
00ec4c51 CM |
3584 | int push_space = 0; |
3585 | int push_items = 0; | |
0783fcfc | 3586 | struct btrfs_item *item; |
34a38218 | 3587 | u32 nr; |
7518a238 | 3588 | u32 right_nritems; |
5f39d397 | 3589 | u32 data_end; |
db94535d | 3590 | u32 this_item_size; |
00ec4c51 | 3591 | |
cfed81a0 CM |
3592 | btrfs_init_map_token(&token); |
3593 | ||
34a38218 CM |
3594 | if (empty) |
3595 | nr = 0; | |
3596 | else | |
99d8f83c | 3597 | nr = max_t(u32, 1, min_slot); |
34a38218 | 3598 | |
31840ae1 | 3599 | if (path->slots[0] >= left_nritems) |
87b29b20 | 3600 | push_space += data_size; |
31840ae1 | 3601 | |
44871b1b | 3602 | slot = path->slots[1]; |
34a38218 CM |
3603 | i = left_nritems - 1; |
3604 | while (i >= nr) { | |
dd3cc16b | 3605 | item = btrfs_item_nr(i); |
db94535d | 3606 | |
31840ae1 ZY |
3607 | if (!empty && push_items > 0) { |
3608 | if (path->slots[0] > i) | |
3609 | break; | |
3610 | if (path->slots[0] == i) { | |
2ff7e61e | 3611 | int space = btrfs_leaf_free_space(fs_info, left); |
31840ae1 ZY |
3612 | if (space + push_space * 2 > free_space) |
3613 | break; | |
3614 | } | |
3615 | } | |
3616 | ||
00ec4c51 | 3617 | if (path->slots[0] == i) |
87b29b20 | 3618 | push_space += data_size; |
db94535d | 3619 | |
db94535d CM |
3620 | this_item_size = btrfs_item_size(left, item); |
3621 | if (this_item_size + sizeof(*item) + push_space > free_space) | |
00ec4c51 | 3622 | break; |
31840ae1 | 3623 | |
00ec4c51 | 3624 | push_items++; |
db94535d | 3625 | push_space += this_item_size + sizeof(*item); |
34a38218 CM |
3626 | if (i == 0) |
3627 | break; | |
3628 | i--; | |
db94535d | 3629 | } |
5f39d397 | 3630 | |
925baedd CM |
3631 | if (push_items == 0) |
3632 | goto out_unlock; | |
5f39d397 | 3633 | |
6c1500f2 | 3634 | WARN_ON(!empty && push_items == left_nritems); |
5f39d397 | 3635 | |
00ec4c51 | 3636 | /* push left to right */ |
5f39d397 | 3637 | right_nritems = btrfs_header_nritems(right); |
34a38218 | 3638 | |
5f39d397 | 3639 | push_space = btrfs_item_end_nr(left, left_nritems - push_items); |
2ff7e61e | 3640 | push_space -= leaf_data_end(fs_info, left); |
5f39d397 | 3641 | |
00ec4c51 | 3642 | /* make room in the right data area */ |
2ff7e61e | 3643 | data_end = leaf_data_end(fs_info, right); |
5f39d397 | 3644 | memmove_extent_buffer(right, |
3d9ec8c4 NB |
3645 | BTRFS_LEAF_DATA_OFFSET + data_end - push_space, |
3646 | BTRFS_LEAF_DATA_OFFSET + data_end, | |
0b246afa | 3647 | BTRFS_LEAF_DATA_SIZE(fs_info) - data_end); |
5f39d397 | 3648 | |
00ec4c51 | 3649 | /* copy from the left data area */ |
3d9ec8c4 | 3650 | copy_extent_buffer(right, left, BTRFS_LEAF_DATA_OFFSET + |
0b246afa | 3651 | BTRFS_LEAF_DATA_SIZE(fs_info) - push_space, |
3d9ec8c4 | 3652 | BTRFS_LEAF_DATA_OFFSET + leaf_data_end(fs_info, left), |
d6025579 | 3653 | push_space); |
5f39d397 CM |
3654 | |
3655 | memmove_extent_buffer(right, btrfs_item_nr_offset(push_items), | |
3656 | btrfs_item_nr_offset(0), | |
3657 | right_nritems * sizeof(struct btrfs_item)); | |
3658 | ||
00ec4c51 | 3659 | /* copy the items from left to right */ |
5f39d397 CM |
3660 | copy_extent_buffer(right, left, btrfs_item_nr_offset(0), |
3661 | btrfs_item_nr_offset(left_nritems - push_items), | |
3662 | push_items * sizeof(struct btrfs_item)); | |
00ec4c51 CM |
3663 | |
3664 | /* update the item pointers */ | |
7518a238 | 3665 | right_nritems += push_items; |
5f39d397 | 3666 | btrfs_set_header_nritems(right, right_nritems); |
0b246afa | 3667 | push_space = BTRFS_LEAF_DATA_SIZE(fs_info); |
7518a238 | 3668 | for (i = 0; i < right_nritems; i++) { |
dd3cc16b | 3669 | item = btrfs_item_nr(i); |
cfed81a0 CM |
3670 | push_space -= btrfs_token_item_size(right, item, &token); |
3671 | btrfs_set_token_item_offset(right, item, push_space, &token); | |
db94535d CM |
3672 | } |
3673 | ||
7518a238 | 3674 | left_nritems -= push_items; |
5f39d397 | 3675 | btrfs_set_header_nritems(left, left_nritems); |
00ec4c51 | 3676 | |
34a38218 CM |
3677 | if (left_nritems) |
3678 | btrfs_mark_buffer_dirty(left); | |
f0486c68 | 3679 | else |
7c302b49 | 3680 | clean_tree_block(fs_info, left); |
f0486c68 | 3681 | |
5f39d397 | 3682 | btrfs_mark_buffer_dirty(right); |
a429e513 | 3683 | |
5f39d397 CM |
3684 | btrfs_item_key(right, &disk_key, 0); |
3685 | btrfs_set_node_key(upper, &disk_key, slot + 1); | |
d6025579 | 3686 | btrfs_mark_buffer_dirty(upper); |
02217ed2 | 3687 | |
00ec4c51 | 3688 | /* then fixup the leaf pointer in the path */ |
7518a238 CM |
3689 | if (path->slots[0] >= left_nritems) { |
3690 | path->slots[0] -= left_nritems; | |
925baedd | 3691 | if (btrfs_header_nritems(path->nodes[0]) == 0) |
7c302b49 | 3692 | clean_tree_block(fs_info, path->nodes[0]); |
925baedd | 3693 | btrfs_tree_unlock(path->nodes[0]); |
5f39d397 CM |
3694 | free_extent_buffer(path->nodes[0]); |
3695 | path->nodes[0] = right; | |
00ec4c51 CM |
3696 | path->slots[1] += 1; |
3697 | } else { | |
925baedd | 3698 | btrfs_tree_unlock(right); |
5f39d397 | 3699 | free_extent_buffer(right); |
00ec4c51 CM |
3700 | } |
3701 | return 0; | |
925baedd CM |
3702 | |
3703 | out_unlock: | |
3704 | btrfs_tree_unlock(right); | |
3705 | free_extent_buffer(right); | |
3706 | return 1; | |
00ec4c51 | 3707 | } |
925baedd | 3708 | |
44871b1b CM |
3709 | /* |
3710 | * push some data in the path leaf to the right, trying to free up at | |
3711 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
3712 | * | |
3713 | * returns 1 if the push failed because the other node didn't have enough | |
3714 | * room, 0 if everything worked out and < 0 if there were major errors. | |
99d8f83c CM |
3715 | * |
3716 | * this will push starting from min_slot to the end of the leaf. It won't | |
3717 | * push any slot lower than min_slot | |
44871b1b CM |
3718 | */ |
3719 | static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root | |
99d8f83c CM |
3720 | *root, struct btrfs_path *path, |
3721 | int min_data_size, int data_size, | |
3722 | int empty, u32 min_slot) | |
44871b1b | 3723 | { |
2ff7e61e | 3724 | struct btrfs_fs_info *fs_info = root->fs_info; |
44871b1b CM |
3725 | struct extent_buffer *left = path->nodes[0]; |
3726 | struct extent_buffer *right; | |
3727 | struct extent_buffer *upper; | |
3728 | int slot; | |
3729 | int free_space; | |
3730 | u32 left_nritems; | |
3731 | int ret; | |
3732 | ||
3733 | if (!path->nodes[1]) | |
3734 | return 1; | |
3735 | ||
3736 | slot = path->slots[1]; | |
3737 | upper = path->nodes[1]; | |
3738 | if (slot >= btrfs_header_nritems(upper) - 1) | |
3739 | return 1; | |
3740 | ||
3741 | btrfs_assert_tree_locked(path->nodes[1]); | |
3742 | ||
2ff7e61e | 3743 | right = read_node_slot(fs_info, upper, slot + 1); |
fb770ae4 LB |
3744 | /* |
3745 | * slot + 1 is not valid or we fail to read the right node, | |
3746 | * no big deal, just return. | |
3747 | */ | |
3748 | if (IS_ERR(right)) | |
91ca338d TI |
3749 | return 1; |
3750 | ||
44871b1b CM |
3751 | btrfs_tree_lock(right); |
3752 | btrfs_set_lock_blocking(right); | |
3753 | ||
2ff7e61e | 3754 | free_space = btrfs_leaf_free_space(fs_info, right); |
44871b1b CM |
3755 | if (free_space < data_size) |
3756 | goto out_unlock; | |
3757 | ||
3758 | /* cow and double check */ | |
3759 | ret = btrfs_cow_block(trans, root, right, upper, | |
3760 | slot + 1, &right); | |
3761 | if (ret) | |
3762 | goto out_unlock; | |
3763 | ||
2ff7e61e | 3764 | free_space = btrfs_leaf_free_space(fs_info, right); |
44871b1b CM |
3765 | if (free_space < data_size) |
3766 | goto out_unlock; | |
3767 | ||
3768 | left_nritems = btrfs_header_nritems(left); | |
3769 | if (left_nritems == 0) | |
3770 | goto out_unlock; | |
3771 | ||
2ef1fed2 FDBM |
3772 | if (path->slots[0] == left_nritems && !empty) { |
3773 | /* Key greater than all keys in the leaf, right neighbor has | |
3774 | * enough room for it and we're not emptying our leaf to delete | |
3775 | * it, therefore use right neighbor to insert the new item and | |
52042d8e | 3776 | * no need to touch/dirty our left leaf. */ |
2ef1fed2 FDBM |
3777 | btrfs_tree_unlock(left); |
3778 | free_extent_buffer(left); | |
3779 | path->nodes[0] = right; | |
3780 | path->slots[0] = 0; | |
3781 | path->slots[1]++; | |
3782 | return 0; | |
3783 | } | |
3784 | ||
1e47eef2 | 3785 | return __push_leaf_right(fs_info, path, min_data_size, empty, |
99d8f83c | 3786 | right, free_space, left_nritems, min_slot); |
44871b1b CM |
3787 | out_unlock: |
3788 | btrfs_tree_unlock(right); | |
3789 | free_extent_buffer(right); | |
3790 | return 1; | |
3791 | } | |
3792 | ||
74123bd7 CM |
3793 | /* |
3794 | * push some data in the path leaf to the left, trying to free up at | |
3795 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
99d8f83c CM |
3796 | * |
3797 | * max_slot can put a limit on how far into the leaf we'll push items. The | |
3798 | * item at 'max_slot' won't be touched. Use (u32)-1 to make us do all the | |
3799 | * items | |
74123bd7 | 3800 | */ |
66cb7ddb | 3801 | static noinline int __push_leaf_left(struct btrfs_fs_info *fs_info, |
44871b1b CM |
3802 | struct btrfs_path *path, int data_size, |
3803 | int empty, struct extent_buffer *left, | |
99d8f83c CM |
3804 | int free_space, u32 right_nritems, |
3805 | u32 max_slot) | |
be0e5c09 | 3806 | { |
5f39d397 CM |
3807 | struct btrfs_disk_key disk_key; |
3808 | struct extent_buffer *right = path->nodes[0]; | |
be0e5c09 | 3809 | int i; |
be0e5c09 CM |
3810 | int push_space = 0; |
3811 | int push_items = 0; | |
0783fcfc | 3812 | struct btrfs_item *item; |
7518a238 | 3813 | u32 old_left_nritems; |
34a38218 | 3814 | u32 nr; |
aa5d6bed | 3815 | int ret = 0; |
db94535d CM |
3816 | u32 this_item_size; |
3817 | u32 old_left_item_size; | |
cfed81a0 CM |
3818 | struct btrfs_map_token token; |
3819 | ||
3820 | btrfs_init_map_token(&token); | |
be0e5c09 | 3821 | |
34a38218 | 3822 | if (empty) |
99d8f83c | 3823 | nr = min(right_nritems, max_slot); |
34a38218 | 3824 | else |
99d8f83c | 3825 | nr = min(right_nritems - 1, max_slot); |
34a38218 CM |
3826 | |
3827 | for (i = 0; i < nr; i++) { | |
dd3cc16b | 3828 | item = btrfs_item_nr(i); |
db94535d | 3829 | |
31840ae1 ZY |
3830 | if (!empty && push_items > 0) { |
3831 | if (path->slots[0] < i) | |
3832 | break; | |
3833 | if (path->slots[0] == i) { | |
2ff7e61e | 3834 | int space = btrfs_leaf_free_space(fs_info, right); |
31840ae1 ZY |
3835 | if (space + push_space * 2 > free_space) |
3836 | break; | |
3837 | } | |
3838 | } | |
3839 | ||
be0e5c09 | 3840 | if (path->slots[0] == i) |
87b29b20 | 3841 | push_space += data_size; |
db94535d CM |
3842 | |
3843 | this_item_size = btrfs_item_size(right, item); | |
3844 | if (this_item_size + sizeof(*item) + push_space > free_space) | |
be0e5c09 | 3845 | break; |
db94535d | 3846 | |
be0e5c09 | 3847 | push_items++; |
db94535d CM |
3848 | push_space += this_item_size + sizeof(*item); |
3849 | } | |
3850 | ||
be0e5c09 | 3851 | if (push_items == 0) { |
925baedd CM |
3852 | ret = 1; |
3853 | goto out; | |
be0e5c09 | 3854 | } |
fae7f21c | 3855 | WARN_ON(!empty && push_items == btrfs_header_nritems(right)); |
5f39d397 | 3856 | |
be0e5c09 | 3857 | /* push data from right to left */ |
5f39d397 CM |
3858 | copy_extent_buffer(left, right, |
3859 | btrfs_item_nr_offset(btrfs_header_nritems(left)), | |
3860 | btrfs_item_nr_offset(0), | |
3861 | push_items * sizeof(struct btrfs_item)); | |
3862 | ||
0b246afa | 3863 | push_space = BTRFS_LEAF_DATA_SIZE(fs_info) - |
d397712b | 3864 | btrfs_item_offset_nr(right, push_items - 1); |
5f39d397 | 3865 | |
3d9ec8c4 | 3866 | copy_extent_buffer(left, right, BTRFS_LEAF_DATA_OFFSET + |
2ff7e61e | 3867 | leaf_data_end(fs_info, left) - push_space, |
3d9ec8c4 | 3868 | BTRFS_LEAF_DATA_OFFSET + |
5f39d397 | 3869 | btrfs_item_offset_nr(right, push_items - 1), |
d6025579 | 3870 | push_space); |
5f39d397 | 3871 | old_left_nritems = btrfs_header_nritems(left); |
87b29b20 | 3872 | BUG_ON(old_left_nritems <= 0); |
eb60ceac | 3873 | |
db94535d | 3874 | old_left_item_size = btrfs_item_offset_nr(left, old_left_nritems - 1); |
0783fcfc | 3875 | for (i = old_left_nritems; i < old_left_nritems + push_items; i++) { |
5f39d397 | 3876 | u32 ioff; |
db94535d | 3877 | |
dd3cc16b | 3878 | item = btrfs_item_nr(i); |
db94535d | 3879 | |
cfed81a0 CM |
3880 | ioff = btrfs_token_item_offset(left, item, &token); |
3881 | btrfs_set_token_item_offset(left, item, | |
0b246afa | 3882 | ioff - (BTRFS_LEAF_DATA_SIZE(fs_info) - old_left_item_size), |
cfed81a0 | 3883 | &token); |
be0e5c09 | 3884 | } |
5f39d397 | 3885 | btrfs_set_header_nritems(left, old_left_nritems + push_items); |
be0e5c09 CM |
3886 | |
3887 | /* fixup right node */ | |
31b1a2bd JL |
3888 | if (push_items > right_nritems) |
3889 | WARN(1, KERN_CRIT "push items %d nr %u\n", push_items, | |
d397712b | 3890 | right_nritems); |
34a38218 CM |
3891 | |
3892 | if (push_items < right_nritems) { | |
3893 | push_space = btrfs_item_offset_nr(right, push_items - 1) - | |
2ff7e61e | 3894 | leaf_data_end(fs_info, right); |
3d9ec8c4 | 3895 | memmove_extent_buffer(right, BTRFS_LEAF_DATA_OFFSET + |
0b246afa | 3896 | BTRFS_LEAF_DATA_SIZE(fs_info) - push_space, |
3d9ec8c4 | 3897 | BTRFS_LEAF_DATA_OFFSET + |
2ff7e61e | 3898 | leaf_data_end(fs_info, right), push_space); |
34a38218 CM |
3899 | |
3900 | memmove_extent_buffer(right, btrfs_item_nr_offset(0), | |
5f39d397 CM |
3901 | btrfs_item_nr_offset(push_items), |
3902 | (btrfs_header_nritems(right) - push_items) * | |
3903 | sizeof(struct btrfs_item)); | |
34a38218 | 3904 | } |
eef1c494 Y |
3905 | right_nritems -= push_items; |
3906 | btrfs_set_header_nritems(right, right_nritems); | |
0b246afa | 3907 | push_space = BTRFS_LEAF_DATA_SIZE(fs_info); |
5f39d397 | 3908 | for (i = 0; i < right_nritems; i++) { |
dd3cc16b | 3909 | item = btrfs_item_nr(i); |
db94535d | 3910 | |
cfed81a0 CM |
3911 | push_space = push_space - btrfs_token_item_size(right, |
3912 | item, &token); | |
3913 | btrfs_set_token_item_offset(right, item, push_space, &token); | |
db94535d | 3914 | } |
eb60ceac | 3915 | |
5f39d397 | 3916 | btrfs_mark_buffer_dirty(left); |
34a38218 CM |
3917 | if (right_nritems) |
3918 | btrfs_mark_buffer_dirty(right); | |
f0486c68 | 3919 | else |
7c302b49 | 3920 | clean_tree_block(fs_info, right); |
098f59c2 | 3921 | |
5f39d397 | 3922 | btrfs_item_key(right, &disk_key, 0); |
b167fa91 | 3923 | fixup_low_keys(path, &disk_key, 1); |
be0e5c09 CM |
3924 | |
3925 | /* then fixup the leaf pointer in the path */ | |
3926 | if (path->slots[0] < push_items) { | |
3927 | path->slots[0] += old_left_nritems; | |
925baedd | 3928 | btrfs_tree_unlock(path->nodes[0]); |
5f39d397 CM |
3929 | free_extent_buffer(path->nodes[0]); |
3930 | path->nodes[0] = left; | |
be0e5c09 CM |
3931 | path->slots[1] -= 1; |
3932 | } else { | |
925baedd | 3933 | btrfs_tree_unlock(left); |
5f39d397 | 3934 | free_extent_buffer(left); |
be0e5c09 CM |
3935 | path->slots[0] -= push_items; |
3936 | } | |
eb60ceac | 3937 | BUG_ON(path->slots[0] < 0); |
aa5d6bed | 3938 | return ret; |
925baedd CM |
3939 | out: |
3940 | btrfs_tree_unlock(left); | |
3941 | free_extent_buffer(left); | |
3942 | return ret; | |
be0e5c09 CM |
3943 | } |
3944 | ||
44871b1b CM |
3945 | /* |
3946 | * push some data in the path leaf to the left, trying to free up at | |
3947 | * least data_size bytes. returns zero if the push worked, nonzero otherwise | |
99d8f83c CM |
3948 | * |
3949 | * max_slot can put a limit on how far into the leaf we'll push items. The | |
3950 | * item at 'max_slot' won't be touched. Use (u32)-1 to make us push all the | |
3951 | * items | |
44871b1b CM |
3952 | */ |
3953 | static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root | |
99d8f83c CM |
3954 | *root, struct btrfs_path *path, int min_data_size, |
3955 | int data_size, int empty, u32 max_slot) | |
44871b1b | 3956 | { |
2ff7e61e | 3957 | struct btrfs_fs_info *fs_info = root->fs_info; |
44871b1b CM |
3958 | struct extent_buffer *right = path->nodes[0]; |
3959 | struct extent_buffer *left; | |
3960 | int slot; | |
3961 | int free_space; | |
3962 | u32 right_nritems; | |
3963 | int ret = 0; | |
3964 | ||
3965 | slot = path->slots[1]; | |
3966 | if (slot == 0) | |
3967 | return 1; | |
3968 | if (!path->nodes[1]) | |
3969 | return 1; | |
3970 | ||
3971 | right_nritems = btrfs_header_nritems(right); | |
3972 | if (right_nritems == 0) | |
3973 | return 1; | |
3974 | ||
3975 | btrfs_assert_tree_locked(path->nodes[1]); | |
3976 | ||
2ff7e61e | 3977 | left = read_node_slot(fs_info, path->nodes[1], slot - 1); |
fb770ae4 LB |
3978 | /* |
3979 | * slot - 1 is not valid or we fail to read the left node, | |
3980 | * no big deal, just return. | |
3981 | */ | |
3982 | if (IS_ERR(left)) | |
91ca338d TI |
3983 | return 1; |
3984 | ||
44871b1b CM |
3985 | btrfs_tree_lock(left); |
3986 | btrfs_set_lock_blocking(left); | |
3987 | ||
2ff7e61e | 3988 | free_space = btrfs_leaf_free_space(fs_info, left); |
44871b1b CM |
3989 | if (free_space < data_size) { |
3990 | ret = 1; | |
3991 | goto out; | |
3992 | } | |
3993 | ||
3994 | /* cow and double check */ | |
3995 | ret = btrfs_cow_block(trans, root, left, | |
3996 | path->nodes[1], slot - 1, &left); | |
3997 | if (ret) { | |
3998 | /* we hit -ENOSPC, but it isn't fatal here */ | |
79787eaa JM |
3999 | if (ret == -ENOSPC) |
4000 | ret = 1; | |
44871b1b CM |
4001 | goto out; |
4002 | } | |
4003 | ||
2ff7e61e | 4004 | free_space = btrfs_leaf_free_space(fs_info, left); |
44871b1b CM |
4005 | if (free_space < data_size) { |
4006 | ret = 1; | |
4007 | goto out; | |
4008 | } | |
4009 | ||
66cb7ddb | 4010 | return __push_leaf_left(fs_info, path, min_data_size, |
99d8f83c CM |
4011 | empty, left, free_space, right_nritems, |
4012 | max_slot); | |
44871b1b CM |
4013 | out: |
4014 | btrfs_tree_unlock(left); | |
4015 | free_extent_buffer(left); | |
4016 | return ret; | |
4017 | } | |
4018 | ||
4019 | /* | |
4020 | * split the path's leaf in two, making sure there is at least data_size | |
4021 | * available for the resulting leaf level of the path. | |
44871b1b | 4022 | */ |
143bede5 | 4023 | static noinline void copy_for_split(struct btrfs_trans_handle *trans, |
2ff7e61e | 4024 | struct btrfs_fs_info *fs_info, |
143bede5 JM |
4025 | struct btrfs_path *path, |
4026 | struct extent_buffer *l, | |
4027 | struct extent_buffer *right, | |
4028 | int slot, int mid, int nritems) | |
44871b1b CM |
4029 | { |
4030 | int data_copy_size; | |
4031 | int rt_data_off; | |
4032 | int i; | |
44871b1b | 4033 | struct btrfs_disk_key disk_key; |
cfed81a0 CM |
4034 | struct btrfs_map_token token; |
4035 | ||
4036 | btrfs_init_map_token(&token); | |
44871b1b CM |
4037 | |
4038 | nritems = nritems - mid; | |
4039 | btrfs_set_header_nritems(right, nritems); | |
2ff7e61e | 4040 | data_copy_size = btrfs_item_end_nr(l, mid) - leaf_data_end(fs_info, l); |
44871b1b CM |
4041 | |
4042 | copy_extent_buffer(right, l, btrfs_item_nr_offset(0), | |
4043 | btrfs_item_nr_offset(mid), | |
4044 | nritems * sizeof(struct btrfs_item)); | |
4045 | ||
4046 | copy_extent_buffer(right, l, | |
3d9ec8c4 NB |
4047 | BTRFS_LEAF_DATA_OFFSET + BTRFS_LEAF_DATA_SIZE(fs_info) - |
4048 | data_copy_size, BTRFS_LEAF_DATA_OFFSET + | |
2ff7e61e | 4049 | leaf_data_end(fs_info, l), data_copy_size); |
44871b1b | 4050 | |
0b246afa | 4051 | rt_data_off = BTRFS_LEAF_DATA_SIZE(fs_info) - btrfs_item_end_nr(l, mid); |
44871b1b CM |
4052 | |
4053 | for (i = 0; i < nritems; i++) { | |
dd3cc16b | 4054 | struct btrfs_item *item = btrfs_item_nr(i); |
44871b1b CM |
4055 | u32 ioff; |
4056 | ||
cfed81a0 CM |
4057 | ioff = btrfs_token_item_offset(right, item, &token); |
4058 | btrfs_set_token_item_offset(right, item, | |
4059 | ioff + rt_data_off, &token); | |
44871b1b CM |
4060 | } |
4061 | ||
44871b1b | 4062 | btrfs_set_header_nritems(l, mid); |
44871b1b | 4063 | btrfs_item_key(right, &disk_key, 0); |
2ff7e61e | 4064 | insert_ptr(trans, fs_info, path, &disk_key, right->start, |
c3e06965 | 4065 | path->slots[1] + 1, 1); |
44871b1b CM |
4066 | |
4067 | btrfs_mark_buffer_dirty(right); | |
4068 | btrfs_mark_buffer_dirty(l); | |
4069 | BUG_ON(path->slots[0] != slot); | |
4070 | ||
44871b1b CM |
4071 | if (mid <= slot) { |
4072 | btrfs_tree_unlock(path->nodes[0]); | |
4073 | free_extent_buffer(path->nodes[0]); | |
4074 | path->nodes[0] = right; | |
4075 | path->slots[0] -= mid; | |
4076 | path->slots[1] += 1; | |
4077 | } else { | |
4078 | btrfs_tree_unlock(right); | |
4079 | free_extent_buffer(right); | |
4080 | } | |
4081 | ||
4082 | BUG_ON(path->slots[0] < 0); | |
44871b1b CM |
4083 | } |
4084 | ||
99d8f83c CM |
4085 | /* |
4086 | * double splits happen when we need to insert a big item in the middle | |
4087 | * of a leaf. A double split can leave us with 3 mostly empty leaves: | |
4088 | * leaf: [ slots 0 - N] [ our target ] [ N + 1 - total in leaf ] | |
4089 | * A B C | |
4090 | * | |
4091 | * We avoid this by trying to push the items on either side of our target | |
4092 | * into the adjacent leaves. If all goes well we can avoid the double split | |
4093 | * completely. | |
4094 | */ | |
4095 | static noinline int push_for_double_split(struct btrfs_trans_handle *trans, | |
4096 | struct btrfs_root *root, | |
4097 | struct btrfs_path *path, | |
4098 | int data_size) | |
4099 | { | |
2ff7e61e | 4100 | struct btrfs_fs_info *fs_info = root->fs_info; |
99d8f83c CM |
4101 | int ret; |
4102 | int progress = 0; | |
4103 | int slot; | |
4104 | u32 nritems; | |
5a4267ca | 4105 | int space_needed = data_size; |
99d8f83c CM |
4106 | |
4107 | slot = path->slots[0]; | |
5a4267ca | 4108 | if (slot < btrfs_header_nritems(path->nodes[0])) |
2ff7e61e | 4109 | space_needed -= btrfs_leaf_free_space(fs_info, path->nodes[0]); |
99d8f83c CM |
4110 | |
4111 | /* | |
4112 | * try to push all the items after our slot into the | |
4113 | * right leaf | |
4114 | */ | |
5a4267ca | 4115 | ret = push_leaf_right(trans, root, path, 1, space_needed, 0, slot); |
99d8f83c CM |
4116 | if (ret < 0) |
4117 | return ret; | |
4118 | ||
4119 | if (ret == 0) | |
4120 | progress++; | |
4121 | ||
4122 | nritems = btrfs_header_nritems(path->nodes[0]); | |
4123 | /* | |
4124 | * our goal is to get our slot at the start or end of a leaf. If | |
4125 | * we've done so we're done | |
4126 | */ | |
4127 | if (path->slots[0] == 0 || path->slots[0] == nritems) | |
4128 | return 0; | |
4129 | ||
2ff7e61e | 4130 | if (btrfs_leaf_free_space(fs_info, path->nodes[0]) >= data_size) |
99d8f83c CM |
4131 | return 0; |
4132 | ||
4133 | /* try to push all the items before our slot into the next leaf */ | |
4134 | slot = path->slots[0]; | |
263d3995 FM |
4135 | space_needed = data_size; |
4136 | if (slot > 0) | |
4137 | space_needed -= btrfs_leaf_free_space(fs_info, path->nodes[0]); | |
5a4267ca | 4138 | ret = push_leaf_left(trans, root, path, 1, space_needed, 0, slot); |
99d8f83c CM |
4139 | if (ret < 0) |
4140 | return ret; | |
4141 | ||
4142 | if (ret == 0) | |
4143 | progress++; | |
4144 | ||
4145 | if (progress) | |
4146 | return 0; | |
4147 | return 1; | |
4148 | } | |
4149 | ||
74123bd7 CM |
4150 | /* |
4151 | * split the path's leaf in two, making sure there is at least data_size | |
4152 | * available for the resulting leaf level of the path. | |
aa5d6bed CM |
4153 | * |
4154 | * returns 0 if all went well and < 0 on failure. | |
74123bd7 | 4155 | */ |
e02119d5 CM |
4156 | static noinline int split_leaf(struct btrfs_trans_handle *trans, |
4157 | struct btrfs_root *root, | |
310712b2 | 4158 | const struct btrfs_key *ins_key, |
e02119d5 CM |
4159 | struct btrfs_path *path, int data_size, |
4160 | int extend) | |
be0e5c09 | 4161 | { |
5d4f98a2 | 4162 | struct btrfs_disk_key disk_key; |
5f39d397 | 4163 | struct extent_buffer *l; |
7518a238 | 4164 | u32 nritems; |
eb60ceac CM |
4165 | int mid; |
4166 | int slot; | |
5f39d397 | 4167 | struct extent_buffer *right; |
b7a0365e | 4168 | struct btrfs_fs_info *fs_info = root->fs_info; |
d4dbff95 | 4169 | int ret = 0; |
aa5d6bed | 4170 | int wret; |
5d4f98a2 | 4171 | int split; |
cc0c5538 | 4172 | int num_doubles = 0; |
99d8f83c | 4173 | int tried_avoid_double = 0; |
aa5d6bed | 4174 | |
a5719521 YZ |
4175 | l = path->nodes[0]; |
4176 | slot = path->slots[0]; | |
4177 | if (extend && data_size + btrfs_item_size_nr(l, slot) + | |
0b246afa | 4178 | sizeof(struct btrfs_item) > BTRFS_LEAF_DATA_SIZE(fs_info)) |
a5719521 YZ |
4179 | return -EOVERFLOW; |
4180 | ||
40689478 | 4181 | /* first try to make some room by pushing left and right */ |
33157e05 | 4182 | if (data_size && path->nodes[1]) { |
5a4267ca FDBM |
4183 | int space_needed = data_size; |
4184 | ||
4185 | if (slot < btrfs_header_nritems(l)) | |
2ff7e61e | 4186 | space_needed -= btrfs_leaf_free_space(fs_info, l); |
5a4267ca FDBM |
4187 | |
4188 | wret = push_leaf_right(trans, root, path, space_needed, | |
4189 | space_needed, 0, 0); | |
d397712b | 4190 | if (wret < 0) |
eaee50e8 | 4191 | return wret; |
3685f791 | 4192 | if (wret) { |
263d3995 FM |
4193 | space_needed = data_size; |
4194 | if (slot > 0) | |
4195 | space_needed -= btrfs_leaf_free_space(fs_info, | |
4196 | l); | |
5a4267ca FDBM |
4197 | wret = push_leaf_left(trans, root, path, space_needed, |
4198 | space_needed, 0, (u32)-1); | |
3685f791 CM |
4199 | if (wret < 0) |
4200 | return wret; | |
4201 | } | |
4202 | l = path->nodes[0]; | |
aa5d6bed | 4203 | |
3685f791 | 4204 | /* did the pushes work? */ |
2ff7e61e | 4205 | if (btrfs_leaf_free_space(fs_info, l) >= data_size) |
3685f791 | 4206 | return 0; |
3326d1b0 | 4207 | } |
aa5d6bed | 4208 | |
5c680ed6 | 4209 | if (!path->nodes[1]) { |
fdd99c72 | 4210 | ret = insert_new_root(trans, root, path, 1); |
5c680ed6 CM |
4211 | if (ret) |
4212 | return ret; | |
4213 | } | |
cc0c5538 | 4214 | again: |
5d4f98a2 | 4215 | split = 1; |
cc0c5538 | 4216 | l = path->nodes[0]; |
eb60ceac | 4217 | slot = path->slots[0]; |
5f39d397 | 4218 | nritems = btrfs_header_nritems(l); |
d397712b | 4219 | mid = (nritems + 1) / 2; |
54aa1f4d | 4220 | |
5d4f98a2 YZ |
4221 | if (mid <= slot) { |
4222 | if (nritems == 1 || | |
4223 | leaf_space_used(l, mid, nritems - mid) + data_size > | |
0b246afa | 4224 | BTRFS_LEAF_DATA_SIZE(fs_info)) { |
5d4f98a2 YZ |
4225 | if (slot >= nritems) { |
4226 | split = 0; | |
4227 | } else { | |
4228 | mid = slot; | |
4229 | if (mid != nritems && | |
4230 | leaf_space_used(l, mid, nritems - mid) + | |
0b246afa | 4231 | data_size > BTRFS_LEAF_DATA_SIZE(fs_info)) { |
99d8f83c CM |
4232 | if (data_size && !tried_avoid_double) |
4233 | goto push_for_double; | |
5d4f98a2 YZ |
4234 | split = 2; |
4235 | } | |
4236 | } | |
4237 | } | |
4238 | } else { | |
4239 | if (leaf_space_used(l, 0, mid) + data_size > | |
0b246afa | 4240 | BTRFS_LEAF_DATA_SIZE(fs_info)) { |
5d4f98a2 YZ |
4241 | if (!extend && data_size && slot == 0) { |
4242 | split = 0; | |
4243 | } else if ((extend || !data_size) && slot == 0) { | |
4244 | mid = 1; | |
4245 | } else { | |
4246 | mid = slot; | |
4247 | if (mid != nritems && | |
4248 | leaf_space_used(l, mid, nritems - mid) + | |
0b246afa | 4249 | data_size > BTRFS_LEAF_DATA_SIZE(fs_info)) { |
99d8f83c CM |
4250 | if (data_size && !tried_avoid_double) |
4251 | goto push_for_double; | |
67871254 | 4252 | split = 2; |
5d4f98a2 YZ |
4253 | } |
4254 | } | |
4255 | } | |
4256 | } | |
4257 | ||
4258 | if (split == 0) | |
4259 | btrfs_cpu_key_to_disk(&disk_key, ins_key); | |
4260 | else | |
4261 | btrfs_item_key(l, &disk_key, mid); | |
4262 | ||
4d75f8a9 DS |
4263 | right = btrfs_alloc_tree_block(trans, root, 0, root->root_key.objectid, |
4264 | &disk_key, 0, l->start, 0); | |
f0486c68 | 4265 | if (IS_ERR(right)) |
5f39d397 | 4266 | return PTR_ERR(right); |
f0486c68 | 4267 | |
0b246afa | 4268 | root_add_used(root, fs_info->nodesize); |
5f39d397 | 4269 | |
5d4f98a2 YZ |
4270 | if (split == 0) { |
4271 | if (mid <= slot) { | |
4272 | btrfs_set_header_nritems(right, 0); | |
2ff7e61e JM |
4273 | insert_ptr(trans, fs_info, path, &disk_key, |
4274 | right->start, path->slots[1] + 1, 1); | |
5d4f98a2 YZ |
4275 | btrfs_tree_unlock(path->nodes[0]); |
4276 | free_extent_buffer(path->nodes[0]); | |
4277 | path->nodes[0] = right; | |
4278 | path->slots[0] = 0; | |
4279 | path->slots[1] += 1; | |
4280 | } else { | |
4281 | btrfs_set_header_nritems(right, 0); | |
2ff7e61e JM |
4282 | insert_ptr(trans, fs_info, path, &disk_key, |
4283 | right->start, path->slots[1], 1); | |
5d4f98a2 YZ |
4284 | btrfs_tree_unlock(path->nodes[0]); |
4285 | free_extent_buffer(path->nodes[0]); | |
4286 | path->nodes[0] = right; | |
4287 | path->slots[0] = 0; | |
143bede5 | 4288 | if (path->slots[1] == 0) |
b167fa91 | 4289 | fixup_low_keys(path, &disk_key, 1); |
d4dbff95 | 4290 | } |
196e0249 LB |
4291 | /* |
4292 | * We create a new leaf 'right' for the required ins_len and | |
4293 | * we'll do btrfs_mark_buffer_dirty() on this leaf after copying | |
4294 | * the content of ins_len to 'right'. | |
4295 | */ | |
5d4f98a2 | 4296 | return ret; |
d4dbff95 | 4297 | } |
74123bd7 | 4298 | |
2ff7e61e | 4299 | copy_for_split(trans, fs_info, path, l, right, slot, mid, nritems); |
31840ae1 | 4300 | |
5d4f98a2 | 4301 | if (split == 2) { |
cc0c5538 CM |
4302 | BUG_ON(num_doubles != 0); |
4303 | num_doubles++; | |
4304 | goto again; | |
a429e513 | 4305 | } |
44871b1b | 4306 | |
143bede5 | 4307 | return 0; |
99d8f83c CM |
4308 | |
4309 | push_for_double: | |
4310 | push_for_double_split(trans, root, path, data_size); | |
4311 | tried_avoid_double = 1; | |
2ff7e61e | 4312 | if (btrfs_leaf_free_space(fs_info, path->nodes[0]) >= data_size) |
99d8f83c CM |
4313 | return 0; |
4314 | goto again; | |
be0e5c09 CM |
4315 | } |
4316 | ||
ad48fd75 YZ |
4317 | static noinline int setup_leaf_for_split(struct btrfs_trans_handle *trans, |
4318 | struct btrfs_root *root, | |
4319 | struct btrfs_path *path, int ins_len) | |
459931ec | 4320 | { |
2ff7e61e | 4321 | struct btrfs_fs_info *fs_info = root->fs_info; |
ad48fd75 | 4322 | struct btrfs_key key; |
459931ec | 4323 | struct extent_buffer *leaf; |
ad48fd75 YZ |
4324 | struct btrfs_file_extent_item *fi; |
4325 | u64 extent_len = 0; | |
4326 | u32 item_size; | |
4327 | int ret; | |
459931ec CM |
4328 | |
4329 | leaf = path->nodes[0]; | |
ad48fd75 YZ |
4330 | btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
4331 | ||
4332 | BUG_ON(key.type != BTRFS_EXTENT_DATA_KEY && | |
4333 | key.type != BTRFS_EXTENT_CSUM_KEY); | |
4334 | ||
2ff7e61e | 4335 | if (btrfs_leaf_free_space(fs_info, leaf) >= ins_len) |
ad48fd75 | 4336 | return 0; |
459931ec CM |
4337 | |
4338 | item_size = btrfs_item_size_nr(leaf, path->slots[0]); | |
ad48fd75 YZ |
4339 | if (key.type == BTRFS_EXTENT_DATA_KEY) { |
4340 | fi = btrfs_item_ptr(leaf, path->slots[0], | |
4341 | struct btrfs_file_extent_item); | |
4342 | extent_len = btrfs_file_extent_num_bytes(leaf, fi); | |
4343 | } | |
b3b4aa74 | 4344 | btrfs_release_path(path); |
459931ec | 4345 | |
459931ec | 4346 | path->keep_locks = 1; |
ad48fd75 YZ |
4347 | path->search_for_split = 1; |
4348 | ret = btrfs_search_slot(trans, root, &key, path, 0, 1); | |
459931ec | 4349 | path->search_for_split = 0; |
a8df6fe6 FM |
4350 | if (ret > 0) |
4351 | ret = -EAGAIN; | |
ad48fd75 YZ |
4352 | if (ret < 0) |
4353 | goto err; | |
459931ec | 4354 | |
ad48fd75 YZ |
4355 | ret = -EAGAIN; |
4356 | leaf = path->nodes[0]; | |
a8df6fe6 FM |
4357 | /* if our item isn't there, return now */ |
4358 | if (item_size != btrfs_item_size_nr(leaf, path->slots[0])) | |
ad48fd75 YZ |
4359 | goto err; |
4360 | ||
109f6aef | 4361 | /* the leaf has changed, it now has room. return now */ |
2ff7e61e | 4362 | if (btrfs_leaf_free_space(fs_info, path->nodes[0]) >= ins_len) |
109f6aef CM |
4363 | goto err; |
4364 | ||
ad48fd75 YZ |
4365 | if (key.type == BTRFS_EXTENT_DATA_KEY) { |
4366 | fi = btrfs_item_ptr(leaf, path->slots[0], | |
4367 | struct btrfs_file_extent_item); | |
4368 | if (extent_len != btrfs_file_extent_num_bytes(leaf, fi)) | |
4369 | goto err; | |
459931ec CM |
4370 | } |
4371 | ||
b9473439 | 4372 | btrfs_set_path_blocking(path); |
ad48fd75 | 4373 | ret = split_leaf(trans, root, &key, path, ins_len, 1); |
f0486c68 YZ |
4374 | if (ret) |
4375 | goto err; | |
459931ec | 4376 | |
ad48fd75 | 4377 | path->keep_locks = 0; |
b9473439 | 4378 | btrfs_unlock_up_safe(path, 1); |
ad48fd75 YZ |
4379 | return 0; |
4380 | err: | |
4381 | path->keep_locks = 0; | |
4382 | return ret; | |
4383 | } | |
4384 | ||
4961e293 | 4385 | static noinline int split_item(struct btrfs_fs_info *fs_info, |
ad48fd75 | 4386 | struct btrfs_path *path, |
310712b2 | 4387 | const struct btrfs_key *new_key, |
ad48fd75 YZ |
4388 | unsigned long split_offset) |
4389 | { | |
4390 | struct extent_buffer *leaf; | |
4391 | struct btrfs_item *item; | |
4392 | struct btrfs_item *new_item; | |
4393 | int slot; | |
4394 | char *buf; | |
4395 | u32 nritems; | |
4396 | u32 item_size; | |
4397 | u32 orig_offset; | |
4398 | struct btrfs_disk_key disk_key; | |
4399 | ||
b9473439 | 4400 | leaf = path->nodes[0]; |
2ff7e61e | 4401 | BUG_ON(btrfs_leaf_free_space(fs_info, leaf) < sizeof(struct btrfs_item)); |
b9473439 | 4402 | |
b4ce94de CM |
4403 | btrfs_set_path_blocking(path); |
4404 | ||
dd3cc16b | 4405 | item = btrfs_item_nr(path->slots[0]); |
459931ec CM |
4406 | orig_offset = btrfs_item_offset(leaf, item); |
4407 | item_size = btrfs_item_size(leaf, item); | |
4408 | ||
459931ec | 4409 | buf = kmalloc(item_size, GFP_NOFS); |
ad48fd75 YZ |
4410 | if (!buf) |
4411 | return -ENOMEM; | |
4412 | ||
459931ec CM |
4413 | read_extent_buffer(leaf, buf, btrfs_item_ptr_offset(leaf, |
4414 | path->slots[0]), item_size); | |
459931ec | 4415 | |
ad48fd75 | 4416 | slot = path->slots[0] + 1; |
459931ec | 4417 | nritems = btrfs_header_nritems(leaf); |
459931ec CM |
4418 | if (slot != nritems) { |
4419 | /* shift the items */ | |
4420 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + 1), | |
ad48fd75 YZ |
4421 | btrfs_item_nr_offset(slot), |
4422 | (nritems - slot) * sizeof(struct btrfs_item)); | |
459931ec CM |
4423 | } |
4424 | ||
4425 | btrfs_cpu_key_to_disk(&disk_key, new_key); | |
4426 | btrfs_set_item_key(leaf, &disk_key, slot); | |
4427 | ||
dd3cc16b | 4428 | new_item = btrfs_item_nr(slot); |
459931ec CM |
4429 | |
4430 | btrfs_set_item_offset(leaf, new_item, orig_offset); | |
4431 | btrfs_set_item_size(leaf, new_item, item_size - split_offset); | |
4432 | ||
4433 | btrfs_set_item_offset(leaf, item, | |
4434 | orig_offset + item_size - split_offset); | |
4435 | btrfs_set_item_size(leaf, item, split_offset); | |
4436 | ||
4437 | btrfs_set_header_nritems(leaf, nritems + 1); | |
4438 | ||
4439 | /* write the data for the start of the original item */ | |
4440 | write_extent_buffer(leaf, buf, | |
4441 | btrfs_item_ptr_offset(leaf, path->slots[0]), | |
4442 | split_offset); | |
4443 | ||
4444 | /* write the data for the new item */ | |
4445 | write_extent_buffer(leaf, buf + split_offset, | |
4446 | btrfs_item_ptr_offset(leaf, slot), | |
4447 | item_size - split_offset); | |
4448 | btrfs_mark_buffer_dirty(leaf); | |
4449 | ||
2ff7e61e | 4450 | BUG_ON(btrfs_leaf_free_space(fs_info, leaf) < 0); |
459931ec | 4451 | kfree(buf); |
ad48fd75 YZ |
4452 | return 0; |
4453 | } | |
4454 | ||
4455 | /* | |
4456 | * This function splits a single item into two items, | |
4457 | * giving 'new_key' to the new item and splitting the | |
4458 | * old one at split_offset (from the start of the item). | |
4459 | * | |
4460 | * The path may be released by this operation. After | |
4461 | * the split, the path is pointing to the old item. The | |
4462 | * new item is going to be in the same node as the old one. | |
4463 | * | |
4464 | * Note, the item being split must be smaller enough to live alone on | |
4465 | * a tree block with room for one extra struct btrfs_item | |
4466 | * | |
4467 | * This allows us to split the item in place, keeping a lock on the | |
4468 | * leaf the entire time. | |
4469 | */ | |
4470 | int btrfs_split_item(struct btrfs_trans_handle *trans, | |
4471 | struct btrfs_root *root, | |
4472 | struct btrfs_path *path, | |
310712b2 | 4473 | const struct btrfs_key *new_key, |
ad48fd75 YZ |
4474 | unsigned long split_offset) |
4475 | { | |
4476 | int ret; | |
4477 | ret = setup_leaf_for_split(trans, root, path, | |
4478 | sizeof(struct btrfs_item)); | |
4479 | if (ret) | |
4480 | return ret; | |
4481 | ||
4961e293 | 4482 | ret = split_item(root->fs_info, path, new_key, split_offset); |
459931ec CM |
4483 | return ret; |
4484 | } | |
4485 | ||
ad48fd75 YZ |
4486 | /* |
4487 | * This function duplicate a item, giving 'new_key' to the new item. | |
4488 | * It guarantees both items live in the same tree leaf and the new item | |
4489 | * is contiguous with the original item. | |
4490 | * | |
4491 | * This allows us to split file extent in place, keeping a lock on the | |
4492 | * leaf the entire time. | |
4493 | */ | |
4494 | int btrfs_duplicate_item(struct btrfs_trans_handle *trans, | |
4495 | struct btrfs_root *root, | |
4496 | struct btrfs_path *path, | |
310712b2 | 4497 | const struct btrfs_key *new_key) |
ad48fd75 YZ |
4498 | { |
4499 | struct extent_buffer *leaf; | |
4500 | int ret; | |
4501 | u32 item_size; | |
4502 | ||
4503 | leaf = path->nodes[0]; | |
4504 | item_size = btrfs_item_size_nr(leaf, path->slots[0]); | |
4505 | ret = setup_leaf_for_split(trans, root, path, | |
4506 | item_size + sizeof(struct btrfs_item)); | |
4507 | if (ret) | |
4508 | return ret; | |
4509 | ||
4510 | path->slots[0]++; | |
afe5fea7 | 4511 | setup_items_for_insert(root, path, new_key, &item_size, |
143bede5 JM |
4512 | item_size, item_size + |
4513 | sizeof(struct btrfs_item), 1); | |
ad48fd75 YZ |
4514 | leaf = path->nodes[0]; |
4515 | memcpy_extent_buffer(leaf, | |
4516 | btrfs_item_ptr_offset(leaf, path->slots[0]), | |
4517 | btrfs_item_ptr_offset(leaf, path->slots[0] - 1), | |
4518 | item_size); | |
4519 | return 0; | |
4520 | } | |
4521 | ||
d352ac68 CM |
4522 | /* |
4523 | * make the item pointed to by the path smaller. new_size indicates | |
4524 | * how small to make it, and from_end tells us if we just chop bytes | |
4525 | * off the end of the item or if we shift the item to chop bytes off | |
4526 | * the front. | |
4527 | */ | |
2ff7e61e JM |
4528 | void btrfs_truncate_item(struct btrfs_fs_info *fs_info, |
4529 | struct btrfs_path *path, u32 new_size, int from_end) | |
b18c6685 | 4530 | { |
b18c6685 | 4531 | int slot; |
5f39d397 CM |
4532 | struct extent_buffer *leaf; |
4533 | struct btrfs_item *item; | |
b18c6685 CM |
4534 | u32 nritems; |
4535 | unsigned int data_end; | |
4536 | unsigned int old_data_start; | |
4537 | unsigned int old_size; | |
4538 | unsigned int size_diff; | |
4539 | int i; | |
cfed81a0 CM |
4540 | struct btrfs_map_token token; |
4541 | ||
4542 | btrfs_init_map_token(&token); | |
b18c6685 | 4543 | |
5f39d397 | 4544 | leaf = path->nodes[0]; |
179e29e4 CM |
4545 | slot = path->slots[0]; |
4546 | ||
4547 | old_size = btrfs_item_size_nr(leaf, slot); | |
4548 | if (old_size == new_size) | |
143bede5 | 4549 | return; |
b18c6685 | 4550 | |
5f39d397 | 4551 | nritems = btrfs_header_nritems(leaf); |
2ff7e61e | 4552 | data_end = leaf_data_end(fs_info, leaf); |
b18c6685 | 4553 | |
5f39d397 | 4554 | old_data_start = btrfs_item_offset_nr(leaf, slot); |
179e29e4 | 4555 | |
b18c6685 CM |
4556 | size_diff = old_size - new_size; |
4557 | ||
4558 | BUG_ON(slot < 0); | |
4559 | BUG_ON(slot >= nritems); | |
4560 | ||
4561 | /* | |
4562 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
4563 | */ | |
4564 | /* first correct the data pointers */ | |
4565 | for (i = slot; i < nritems; i++) { | |
5f39d397 | 4566 | u32 ioff; |
dd3cc16b | 4567 | item = btrfs_item_nr(i); |
db94535d | 4568 | |
cfed81a0 CM |
4569 | ioff = btrfs_token_item_offset(leaf, item, &token); |
4570 | btrfs_set_token_item_offset(leaf, item, | |
4571 | ioff + size_diff, &token); | |
b18c6685 | 4572 | } |
db94535d | 4573 | |
b18c6685 | 4574 | /* shift the data */ |
179e29e4 | 4575 | if (from_end) { |
3d9ec8c4 NB |
4576 | memmove_extent_buffer(leaf, BTRFS_LEAF_DATA_OFFSET + |
4577 | data_end + size_diff, BTRFS_LEAF_DATA_OFFSET + | |
179e29e4 CM |
4578 | data_end, old_data_start + new_size - data_end); |
4579 | } else { | |
4580 | struct btrfs_disk_key disk_key; | |
4581 | u64 offset; | |
4582 | ||
4583 | btrfs_item_key(leaf, &disk_key, slot); | |
4584 | ||
4585 | if (btrfs_disk_key_type(&disk_key) == BTRFS_EXTENT_DATA_KEY) { | |
4586 | unsigned long ptr; | |
4587 | struct btrfs_file_extent_item *fi; | |
4588 | ||
4589 | fi = btrfs_item_ptr(leaf, slot, | |
4590 | struct btrfs_file_extent_item); | |
4591 | fi = (struct btrfs_file_extent_item *)( | |
4592 | (unsigned long)fi - size_diff); | |
4593 | ||
4594 | if (btrfs_file_extent_type(leaf, fi) == | |
4595 | BTRFS_FILE_EXTENT_INLINE) { | |
4596 | ptr = btrfs_item_ptr_offset(leaf, slot); | |
4597 | memmove_extent_buffer(leaf, ptr, | |
d397712b | 4598 | (unsigned long)fi, |
7ec20afb | 4599 | BTRFS_FILE_EXTENT_INLINE_DATA_START); |
179e29e4 CM |
4600 | } |
4601 | } | |
4602 | ||
3d9ec8c4 NB |
4603 | memmove_extent_buffer(leaf, BTRFS_LEAF_DATA_OFFSET + |
4604 | data_end + size_diff, BTRFS_LEAF_DATA_OFFSET + | |
179e29e4 CM |
4605 | data_end, old_data_start - data_end); |
4606 | ||
4607 | offset = btrfs_disk_key_offset(&disk_key); | |
4608 | btrfs_set_disk_key_offset(&disk_key, offset + size_diff); | |
4609 | btrfs_set_item_key(leaf, &disk_key, slot); | |
4610 | if (slot == 0) | |
b167fa91 | 4611 | fixup_low_keys(path, &disk_key, 1); |
179e29e4 | 4612 | } |
5f39d397 | 4613 | |
dd3cc16b | 4614 | item = btrfs_item_nr(slot); |
5f39d397 CM |
4615 | btrfs_set_item_size(leaf, item, new_size); |
4616 | btrfs_mark_buffer_dirty(leaf); | |
b18c6685 | 4617 | |
2ff7e61e | 4618 | if (btrfs_leaf_free_space(fs_info, leaf) < 0) { |
a4f78750 | 4619 | btrfs_print_leaf(leaf); |
b18c6685 | 4620 | BUG(); |
5f39d397 | 4621 | } |
b18c6685 CM |
4622 | } |
4623 | ||
d352ac68 | 4624 | /* |
8f69dbd2 | 4625 | * make the item pointed to by the path bigger, data_size is the added size. |
d352ac68 | 4626 | */ |
2ff7e61e | 4627 | void btrfs_extend_item(struct btrfs_fs_info *fs_info, struct btrfs_path *path, |
143bede5 | 4628 | u32 data_size) |
6567e837 | 4629 | { |
6567e837 | 4630 | int slot; |
5f39d397 CM |
4631 | struct extent_buffer *leaf; |
4632 | struct btrfs_item *item; | |
6567e837 CM |
4633 | u32 nritems; |
4634 | unsigned int data_end; | |
4635 | unsigned int old_data; | |
4636 | unsigned int old_size; | |
4637 | int i; | |
cfed81a0 CM |
4638 | struct btrfs_map_token token; |
4639 | ||
4640 | btrfs_init_map_token(&token); | |
6567e837 | 4641 | |
5f39d397 | 4642 | leaf = path->nodes[0]; |
6567e837 | 4643 | |
5f39d397 | 4644 | nritems = btrfs_header_nritems(leaf); |
2ff7e61e | 4645 | data_end = leaf_data_end(fs_info, leaf); |
6567e837 | 4646 | |
2ff7e61e | 4647 | if (btrfs_leaf_free_space(fs_info, leaf) < data_size) { |
a4f78750 | 4648 | btrfs_print_leaf(leaf); |
6567e837 | 4649 | BUG(); |
5f39d397 | 4650 | } |
6567e837 | 4651 | slot = path->slots[0]; |
5f39d397 | 4652 | old_data = btrfs_item_end_nr(leaf, slot); |
6567e837 CM |
4653 | |
4654 | BUG_ON(slot < 0); | |
3326d1b0 | 4655 | if (slot >= nritems) { |
a4f78750 | 4656 | btrfs_print_leaf(leaf); |
0b246afa JM |
4657 | btrfs_crit(fs_info, "slot %d too large, nritems %d", |
4658 | slot, nritems); | |
3326d1b0 CM |
4659 | BUG_ON(1); |
4660 | } | |
6567e837 CM |
4661 | |
4662 | /* | |
4663 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
4664 | */ | |
4665 | /* first correct the data pointers */ | |
4666 | for (i = slot; i < nritems; i++) { | |
5f39d397 | 4667 | u32 ioff; |
dd3cc16b | 4668 | item = btrfs_item_nr(i); |
db94535d | 4669 | |
cfed81a0 CM |
4670 | ioff = btrfs_token_item_offset(leaf, item, &token); |
4671 | btrfs_set_token_item_offset(leaf, item, | |
4672 | ioff - data_size, &token); | |
6567e837 | 4673 | } |
5f39d397 | 4674 | |
6567e837 | 4675 | /* shift the data */ |
3d9ec8c4 NB |
4676 | memmove_extent_buffer(leaf, BTRFS_LEAF_DATA_OFFSET + |
4677 | data_end - data_size, BTRFS_LEAF_DATA_OFFSET + | |
6567e837 | 4678 | data_end, old_data - data_end); |
5f39d397 | 4679 | |
6567e837 | 4680 | data_end = old_data; |
5f39d397 | 4681 | old_size = btrfs_item_size_nr(leaf, slot); |
dd3cc16b | 4682 | item = btrfs_item_nr(slot); |
5f39d397 CM |
4683 | btrfs_set_item_size(leaf, item, old_size + data_size); |
4684 | btrfs_mark_buffer_dirty(leaf); | |
6567e837 | 4685 | |
2ff7e61e | 4686 | if (btrfs_leaf_free_space(fs_info, leaf) < 0) { |
a4f78750 | 4687 | btrfs_print_leaf(leaf); |
6567e837 | 4688 | BUG(); |
5f39d397 | 4689 | } |
6567e837 CM |
4690 | } |
4691 | ||
74123bd7 | 4692 | /* |
44871b1b CM |
4693 | * this is a helper for btrfs_insert_empty_items, the main goal here is |
4694 | * to save stack depth by doing the bulk of the work in a function | |
4695 | * that doesn't call btrfs_search_slot | |
74123bd7 | 4696 | */ |
afe5fea7 | 4697 | void setup_items_for_insert(struct btrfs_root *root, struct btrfs_path *path, |
310712b2 | 4698 | const struct btrfs_key *cpu_key, u32 *data_size, |
143bede5 | 4699 | u32 total_data, u32 total_size, int nr) |
be0e5c09 | 4700 | { |
0b246afa | 4701 | struct btrfs_fs_info *fs_info = root->fs_info; |
5f39d397 | 4702 | struct btrfs_item *item; |
9c58309d | 4703 | int i; |
7518a238 | 4704 | u32 nritems; |
be0e5c09 | 4705 | unsigned int data_end; |
e2fa7227 | 4706 | struct btrfs_disk_key disk_key; |
44871b1b CM |
4707 | struct extent_buffer *leaf; |
4708 | int slot; | |
cfed81a0 CM |
4709 | struct btrfs_map_token token; |
4710 | ||
24cdc847 FM |
4711 | if (path->slots[0] == 0) { |
4712 | btrfs_cpu_key_to_disk(&disk_key, cpu_key); | |
b167fa91 | 4713 | fixup_low_keys(path, &disk_key, 1); |
24cdc847 FM |
4714 | } |
4715 | btrfs_unlock_up_safe(path, 1); | |
4716 | ||
cfed81a0 | 4717 | btrfs_init_map_token(&token); |
e2fa7227 | 4718 | |
5f39d397 | 4719 | leaf = path->nodes[0]; |
44871b1b | 4720 | slot = path->slots[0]; |
74123bd7 | 4721 | |
5f39d397 | 4722 | nritems = btrfs_header_nritems(leaf); |
2ff7e61e | 4723 | data_end = leaf_data_end(fs_info, leaf); |
eb60ceac | 4724 | |
2ff7e61e | 4725 | if (btrfs_leaf_free_space(fs_info, leaf) < total_size) { |
a4f78750 | 4726 | btrfs_print_leaf(leaf); |
0b246afa | 4727 | btrfs_crit(fs_info, "not enough freespace need %u have %d", |
2ff7e61e | 4728 | total_size, btrfs_leaf_free_space(fs_info, leaf)); |
be0e5c09 | 4729 | BUG(); |
d4dbff95 | 4730 | } |
5f39d397 | 4731 | |
be0e5c09 | 4732 | if (slot != nritems) { |
5f39d397 | 4733 | unsigned int old_data = btrfs_item_end_nr(leaf, slot); |
be0e5c09 | 4734 | |
5f39d397 | 4735 | if (old_data < data_end) { |
a4f78750 | 4736 | btrfs_print_leaf(leaf); |
0b246afa | 4737 | btrfs_crit(fs_info, "slot %d old_data %d data_end %d", |
5d163e0e | 4738 | slot, old_data, data_end); |
5f39d397 CM |
4739 | BUG_ON(1); |
4740 | } | |
be0e5c09 CM |
4741 | /* |
4742 | * item0..itemN ... dataN.offset..dataN.size .. data0.size | |
4743 | */ | |
4744 | /* first correct the data pointers */ | |
0783fcfc | 4745 | for (i = slot; i < nritems; i++) { |
5f39d397 | 4746 | u32 ioff; |
db94535d | 4747 | |
62e85577 | 4748 | item = btrfs_item_nr(i); |
cfed81a0 CM |
4749 | ioff = btrfs_token_item_offset(leaf, item, &token); |
4750 | btrfs_set_token_item_offset(leaf, item, | |
4751 | ioff - total_data, &token); | |
0783fcfc | 4752 | } |
be0e5c09 | 4753 | /* shift the items */ |
9c58309d | 4754 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr), |
5f39d397 | 4755 | btrfs_item_nr_offset(slot), |
d6025579 | 4756 | (nritems - slot) * sizeof(struct btrfs_item)); |
be0e5c09 CM |
4757 | |
4758 | /* shift the data */ | |
3d9ec8c4 NB |
4759 | memmove_extent_buffer(leaf, BTRFS_LEAF_DATA_OFFSET + |
4760 | data_end - total_data, BTRFS_LEAF_DATA_OFFSET + | |
d6025579 | 4761 | data_end, old_data - data_end); |
be0e5c09 CM |
4762 | data_end = old_data; |
4763 | } | |
5f39d397 | 4764 | |
62e2749e | 4765 | /* setup the item for the new data */ |
9c58309d CM |
4766 | for (i = 0; i < nr; i++) { |
4767 | btrfs_cpu_key_to_disk(&disk_key, cpu_key + i); | |
4768 | btrfs_set_item_key(leaf, &disk_key, slot + i); | |
dd3cc16b | 4769 | item = btrfs_item_nr(slot + i); |
cfed81a0 CM |
4770 | btrfs_set_token_item_offset(leaf, item, |
4771 | data_end - data_size[i], &token); | |
9c58309d | 4772 | data_end -= data_size[i]; |
cfed81a0 | 4773 | btrfs_set_token_item_size(leaf, item, data_size[i], &token); |
9c58309d | 4774 | } |
44871b1b | 4775 | |
9c58309d | 4776 | btrfs_set_header_nritems(leaf, nritems + nr); |
b9473439 | 4777 | btrfs_mark_buffer_dirty(leaf); |
aa5d6bed | 4778 | |
2ff7e61e | 4779 | if (btrfs_leaf_free_space(fs_info, leaf) < 0) { |
a4f78750 | 4780 | btrfs_print_leaf(leaf); |
be0e5c09 | 4781 | BUG(); |
5f39d397 | 4782 | } |
44871b1b CM |
4783 | } |
4784 | ||
4785 | /* | |
4786 | * Given a key and some data, insert items into the tree. | |
4787 | * This does all the path init required, making room in the tree if needed. | |
4788 | */ | |
4789 | int btrfs_insert_empty_items(struct btrfs_trans_handle *trans, | |
4790 | struct btrfs_root *root, | |
4791 | struct btrfs_path *path, | |
310712b2 | 4792 | const struct btrfs_key *cpu_key, u32 *data_size, |
44871b1b CM |
4793 | int nr) |
4794 | { | |
44871b1b CM |
4795 | int ret = 0; |
4796 | int slot; | |
4797 | int i; | |
4798 | u32 total_size = 0; | |
4799 | u32 total_data = 0; | |
4800 | ||
4801 | for (i = 0; i < nr; i++) | |
4802 | total_data += data_size[i]; | |
4803 | ||
4804 | total_size = total_data + (nr * sizeof(struct btrfs_item)); | |
4805 | ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1); | |
4806 | if (ret == 0) | |
4807 | return -EEXIST; | |
4808 | if (ret < 0) | |
143bede5 | 4809 | return ret; |
44871b1b | 4810 | |
44871b1b CM |
4811 | slot = path->slots[0]; |
4812 | BUG_ON(slot < 0); | |
4813 | ||
afe5fea7 | 4814 | setup_items_for_insert(root, path, cpu_key, data_size, |
44871b1b | 4815 | total_data, total_size, nr); |
143bede5 | 4816 | return 0; |
62e2749e CM |
4817 | } |
4818 | ||
4819 | /* | |
4820 | * Given a key and some data, insert an item into the tree. | |
4821 | * This does all the path init required, making room in the tree if needed. | |
4822 | */ | |
310712b2 OS |
4823 | int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
4824 | const struct btrfs_key *cpu_key, void *data, | |
4825 | u32 data_size) | |
62e2749e CM |
4826 | { |
4827 | int ret = 0; | |
2c90e5d6 | 4828 | struct btrfs_path *path; |
5f39d397 CM |
4829 | struct extent_buffer *leaf; |
4830 | unsigned long ptr; | |
62e2749e | 4831 | |
2c90e5d6 | 4832 | path = btrfs_alloc_path(); |
db5b493a TI |
4833 | if (!path) |
4834 | return -ENOMEM; | |
2c90e5d6 | 4835 | ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size); |
62e2749e | 4836 | if (!ret) { |
5f39d397 CM |
4837 | leaf = path->nodes[0]; |
4838 | ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); | |
4839 | write_extent_buffer(leaf, data, ptr, data_size); | |
4840 | btrfs_mark_buffer_dirty(leaf); | |
62e2749e | 4841 | } |
2c90e5d6 | 4842 | btrfs_free_path(path); |
aa5d6bed | 4843 | return ret; |
be0e5c09 CM |
4844 | } |
4845 | ||
74123bd7 | 4846 | /* |
5de08d7d | 4847 | * delete the pointer from a given node. |
74123bd7 | 4848 | * |
d352ac68 CM |
4849 | * the tree should have been previously balanced so the deletion does not |
4850 | * empty a node. | |
74123bd7 | 4851 | */ |
afe5fea7 TI |
4852 | static void del_ptr(struct btrfs_root *root, struct btrfs_path *path, |
4853 | int level, int slot) | |
be0e5c09 | 4854 | { |
5f39d397 | 4855 | struct extent_buffer *parent = path->nodes[level]; |
7518a238 | 4856 | u32 nritems; |
f3ea38da | 4857 | int ret; |
be0e5c09 | 4858 | |
5f39d397 | 4859 | nritems = btrfs_header_nritems(parent); |
d397712b | 4860 | if (slot != nritems - 1) { |
bf1d3425 DS |
4861 | if (level) { |
4862 | ret = tree_mod_log_insert_move(parent, slot, slot + 1, | |
a446a979 | 4863 | nritems - slot - 1); |
bf1d3425 DS |
4864 | BUG_ON(ret < 0); |
4865 | } | |
5f39d397 CM |
4866 | memmove_extent_buffer(parent, |
4867 | btrfs_node_key_ptr_offset(slot), | |
4868 | btrfs_node_key_ptr_offset(slot + 1), | |
d6025579 CM |
4869 | sizeof(struct btrfs_key_ptr) * |
4870 | (nritems - slot - 1)); | |
57ba86c0 | 4871 | } else if (level) { |
e09c2efe DS |
4872 | ret = tree_mod_log_insert_key(parent, slot, MOD_LOG_KEY_REMOVE, |
4873 | GFP_NOFS); | |
57ba86c0 | 4874 | BUG_ON(ret < 0); |
bb803951 | 4875 | } |
f3ea38da | 4876 | |
7518a238 | 4877 | nritems--; |
5f39d397 | 4878 | btrfs_set_header_nritems(parent, nritems); |
7518a238 | 4879 | if (nritems == 0 && parent == root->node) { |
5f39d397 | 4880 | BUG_ON(btrfs_header_level(root->node) != 1); |
bb803951 | 4881 | /* just turn the root into a leaf and break */ |
5f39d397 | 4882 | btrfs_set_header_level(root->node, 0); |
bb803951 | 4883 | } else if (slot == 0) { |
5f39d397 CM |
4884 | struct btrfs_disk_key disk_key; |
4885 | ||
4886 | btrfs_node_key(parent, &disk_key, 0); | |
b167fa91 | 4887 | fixup_low_keys(path, &disk_key, level + 1); |
be0e5c09 | 4888 | } |
d6025579 | 4889 | btrfs_mark_buffer_dirty(parent); |
be0e5c09 CM |
4890 | } |
4891 | ||
323ac95b CM |
4892 | /* |
4893 | * a helper function to delete the leaf pointed to by path->slots[1] and | |
5d4f98a2 | 4894 | * path->nodes[1]. |
323ac95b CM |
4895 | * |
4896 | * This deletes the pointer in path->nodes[1] and frees the leaf | |
4897 | * block extent. zero is returned if it all worked out, < 0 otherwise. | |
4898 | * | |
4899 | * The path must have already been setup for deleting the leaf, including | |
4900 | * all the proper balancing. path->nodes[1] must be locked. | |
4901 | */ | |
143bede5 JM |
4902 | static noinline void btrfs_del_leaf(struct btrfs_trans_handle *trans, |
4903 | struct btrfs_root *root, | |
4904 | struct btrfs_path *path, | |
4905 | struct extent_buffer *leaf) | |
323ac95b | 4906 | { |
5d4f98a2 | 4907 | WARN_ON(btrfs_header_generation(leaf) != trans->transid); |
afe5fea7 | 4908 | del_ptr(root, path, 1, path->slots[1]); |
323ac95b | 4909 | |
4d081c41 CM |
4910 | /* |
4911 | * btrfs_free_extent is expensive, we want to make sure we | |
4912 | * aren't holding any locks when we call it | |
4913 | */ | |
4914 | btrfs_unlock_up_safe(path, 0); | |
4915 | ||
f0486c68 YZ |
4916 | root_sub_used(root, leaf->len); |
4917 | ||
3083ee2e | 4918 | extent_buffer_get(leaf); |
5581a51a | 4919 | btrfs_free_tree_block(trans, root, leaf, 0, 1); |
3083ee2e | 4920 | free_extent_buffer_stale(leaf); |
323ac95b | 4921 | } |
74123bd7 CM |
4922 | /* |
4923 | * delete the item at the leaf level in path. If that empties | |
4924 | * the leaf, remove it from the tree | |
4925 | */ | |
85e21bac CM |
4926 | int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
4927 | struct btrfs_path *path, int slot, int nr) | |
be0e5c09 | 4928 | { |
0b246afa | 4929 | struct btrfs_fs_info *fs_info = root->fs_info; |
5f39d397 CM |
4930 | struct extent_buffer *leaf; |
4931 | struct btrfs_item *item; | |
ce0eac2a AM |
4932 | u32 last_off; |
4933 | u32 dsize = 0; | |
aa5d6bed CM |
4934 | int ret = 0; |
4935 | int wret; | |
85e21bac | 4936 | int i; |
7518a238 | 4937 | u32 nritems; |
cfed81a0 CM |
4938 | struct btrfs_map_token token; |
4939 | ||
4940 | btrfs_init_map_token(&token); | |
be0e5c09 | 4941 | |
5f39d397 | 4942 | leaf = path->nodes[0]; |
85e21bac CM |
4943 | last_off = btrfs_item_offset_nr(leaf, slot + nr - 1); |
4944 | ||
4945 | for (i = 0; i < nr; i++) | |
4946 | dsize += btrfs_item_size_nr(leaf, slot + i); | |
4947 | ||
5f39d397 | 4948 | nritems = btrfs_header_nritems(leaf); |
be0e5c09 | 4949 | |
85e21bac | 4950 | if (slot + nr != nritems) { |
2ff7e61e | 4951 | int data_end = leaf_data_end(fs_info, leaf); |
5f39d397 | 4952 | |
3d9ec8c4 | 4953 | memmove_extent_buffer(leaf, BTRFS_LEAF_DATA_OFFSET + |
d6025579 | 4954 | data_end + dsize, |
3d9ec8c4 | 4955 | BTRFS_LEAF_DATA_OFFSET + data_end, |
85e21bac | 4956 | last_off - data_end); |
5f39d397 | 4957 | |
85e21bac | 4958 | for (i = slot + nr; i < nritems; i++) { |
5f39d397 | 4959 | u32 ioff; |
db94535d | 4960 | |
dd3cc16b | 4961 | item = btrfs_item_nr(i); |
cfed81a0 CM |
4962 | ioff = btrfs_token_item_offset(leaf, item, &token); |
4963 | btrfs_set_token_item_offset(leaf, item, | |
4964 | ioff + dsize, &token); | |
0783fcfc | 4965 | } |
db94535d | 4966 | |
5f39d397 | 4967 | memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot), |
85e21bac | 4968 | btrfs_item_nr_offset(slot + nr), |
d6025579 | 4969 | sizeof(struct btrfs_item) * |
85e21bac | 4970 | (nritems - slot - nr)); |
be0e5c09 | 4971 | } |
85e21bac CM |
4972 | btrfs_set_header_nritems(leaf, nritems - nr); |
4973 | nritems -= nr; | |
5f39d397 | 4974 | |
74123bd7 | 4975 | /* delete the leaf if we've emptied it */ |
7518a238 | 4976 | if (nritems == 0) { |
5f39d397 CM |
4977 | if (leaf == root->node) { |
4978 | btrfs_set_header_level(leaf, 0); | |
9a8dd150 | 4979 | } else { |
f0486c68 | 4980 | btrfs_set_path_blocking(path); |
7c302b49 | 4981 | clean_tree_block(fs_info, leaf); |
143bede5 | 4982 | btrfs_del_leaf(trans, root, path, leaf); |
9a8dd150 | 4983 | } |
be0e5c09 | 4984 | } else { |
7518a238 | 4985 | int used = leaf_space_used(leaf, 0, nritems); |
aa5d6bed | 4986 | if (slot == 0) { |
5f39d397 CM |
4987 | struct btrfs_disk_key disk_key; |
4988 | ||
4989 | btrfs_item_key(leaf, &disk_key, 0); | |
b167fa91 | 4990 | fixup_low_keys(path, &disk_key, 1); |
aa5d6bed | 4991 | } |
aa5d6bed | 4992 | |
74123bd7 | 4993 | /* delete the leaf if it is mostly empty */ |
0b246afa | 4994 | if (used < BTRFS_LEAF_DATA_SIZE(fs_info) / 3) { |
be0e5c09 CM |
4995 | /* push_leaf_left fixes the path. |
4996 | * make sure the path still points to our leaf | |
4997 | * for possible call to del_ptr below | |
4998 | */ | |
4920c9ac | 4999 | slot = path->slots[1]; |
5f39d397 CM |
5000 | extent_buffer_get(leaf); |
5001 | ||
b9473439 | 5002 | btrfs_set_path_blocking(path); |
99d8f83c CM |
5003 | wret = push_leaf_left(trans, root, path, 1, 1, |
5004 | 1, (u32)-1); | |
54aa1f4d | 5005 | if (wret < 0 && wret != -ENOSPC) |
aa5d6bed | 5006 | ret = wret; |
5f39d397 CM |
5007 | |
5008 | if (path->nodes[0] == leaf && | |
5009 | btrfs_header_nritems(leaf)) { | |
99d8f83c CM |
5010 | wret = push_leaf_right(trans, root, path, 1, |
5011 | 1, 1, 0); | |
54aa1f4d | 5012 | if (wret < 0 && wret != -ENOSPC) |
aa5d6bed CM |
5013 | ret = wret; |
5014 | } | |
5f39d397 CM |
5015 | |
5016 | if (btrfs_header_nritems(leaf) == 0) { | |
323ac95b | 5017 | path->slots[1] = slot; |
143bede5 | 5018 | btrfs_del_leaf(trans, root, path, leaf); |
5f39d397 | 5019 | free_extent_buffer(leaf); |
143bede5 | 5020 | ret = 0; |
5de08d7d | 5021 | } else { |
925baedd CM |
5022 | /* if we're still in the path, make sure |
5023 | * we're dirty. Otherwise, one of the | |
5024 | * push_leaf functions must have already | |
5025 | * dirtied this buffer | |
5026 | */ | |
5027 | if (path->nodes[0] == leaf) | |
5028 | btrfs_mark_buffer_dirty(leaf); | |
5f39d397 | 5029 | free_extent_buffer(leaf); |
be0e5c09 | 5030 | } |
d5719762 | 5031 | } else { |
5f39d397 | 5032 | btrfs_mark_buffer_dirty(leaf); |
be0e5c09 CM |
5033 | } |
5034 | } | |
aa5d6bed | 5035 | return ret; |
be0e5c09 CM |
5036 | } |
5037 | ||
7bb86316 | 5038 | /* |
925baedd | 5039 | * search the tree again to find a leaf with lesser keys |
7bb86316 CM |
5040 | * returns 0 if it found something or 1 if there are no lesser leaves. |
5041 | * returns < 0 on io errors. | |
d352ac68 CM |
5042 | * |
5043 | * This may release the path, and so you may lose any locks held at the | |
5044 | * time you call it. | |
7bb86316 | 5045 | */ |
16e7549f | 5046 | int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path) |
7bb86316 | 5047 | { |
925baedd CM |
5048 | struct btrfs_key key; |
5049 | struct btrfs_disk_key found_key; | |
5050 | int ret; | |
7bb86316 | 5051 | |
925baedd | 5052 | btrfs_item_key_to_cpu(path->nodes[0], &key, 0); |
7bb86316 | 5053 | |
e8b0d724 | 5054 | if (key.offset > 0) { |
925baedd | 5055 | key.offset--; |
e8b0d724 | 5056 | } else if (key.type > 0) { |
925baedd | 5057 | key.type--; |
e8b0d724 FDBM |
5058 | key.offset = (u64)-1; |
5059 | } else if (key.objectid > 0) { | |
925baedd | 5060 | key.objectid--; |
e8b0d724 FDBM |
5061 | key.type = (u8)-1; |
5062 | key.offset = (u64)-1; | |
5063 | } else { | |
925baedd | 5064 | return 1; |
e8b0d724 | 5065 | } |
7bb86316 | 5066 | |
b3b4aa74 | 5067 | btrfs_release_path(path); |
925baedd CM |
5068 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
5069 | if (ret < 0) | |
5070 | return ret; | |
5071 | btrfs_item_key(path->nodes[0], &found_key, 0); | |
5072 | ret = comp_keys(&found_key, &key); | |
337c6f68 FM |
5073 | /* |
5074 | * We might have had an item with the previous key in the tree right | |
5075 | * before we released our path. And after we released our path, that | |
5076 | * item might have been pushed to the first slot (0) of the leaf we | |
5077 | * were holding due to a tree balance. Alternatively, an item with the | |
5078 | * previous key can exist as the only element of a leaf (big fat item). | |
5079 | * Therefore account for these 2 cases, so that our callers (like | |
5080 | * btrfs_previous_item) don't miss an existing item with a key matching | |
5081 | * the previous key we computed above. | |
5082 | */ | |
5083 | if (ret <= 0) | |
925baedd CM |
5084 | return 0; |
5085 | return 1; | |
7bb86316 CM |
5086 | } |
5087 | ||
3f157a2f CM |
5088 | /* |
5089 | * A helper function to walk down the tree starting at min_key, and looking | |
de78b51a ES |
5090 | * for nodes or leaves that are have a minimum transaction id. |
5091 | * This is used by the btree defrag code, and tree logging | |
3f157a2f CM |
5092 | * |
5093 | * This does not cow, but it does stuff the starting key it finds back | |
5094 | * into min_key, so you can call btrfs_search_slot with cow=1 on the | |
5095 | * key and get a writable path. | |
5096 | * | |
3f157a2f CM |
5097 | * This honors path->lowest_level to prevent descent past a given level |
5098 | * of the tree. | |
5099 | * | |
d352ac68 CM |
5100 | * min_trans indicates the oldest transaction that you are interested |
5101 | * in walking through. Any nodes or leaves older than min_trans are | |
5102 | * skipped over (without reading them). | |
5103 | * | |
3f157a2f CM |
5104 | * returns zero if something useful was found, < 0 on error and 1 if there |
5105 | * was nothing in the tree that matched the search criteria. | |
5106 | */ | |
5107 | int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key, | |
de78b51a | 5108 | struct btrfs_path *path, |
3f157a2f CM |
5109 | u64 min_trans) |
5110 | { | |
2ff7e61e | 5111 | struct btrfs_fs_info *fs_info = root->fs_info; |
3f157a2f CM |
5112 | struct extent_buffer *cur; |
5113 | struct btrfs_key found_key; | |
5114 | int slot; | |
9652480b | 5115 | int sret; |
3f157a2f CM |
5116 | u32 nritems; |
5117 | int level; | |
5118 | int ret = 1; | |
f98de9b9 | 5119 | int keep_locks = path->keep_locks; |
3f157a2f | 5120 | |
f98de9b9 | 5121 | path->keep_locks = 1; |
3f157a2f | 5122 | again: |
bd681513 | 5123 | cur = btrfs_read_lock_root_node(root); |
3f157a2f | 5124 | level = btrfs_header_level(cur); |
e02119d5 | 5125 | WARN_ON(path->nodes[level]); |
3f157a2f | 5126 | path->nodes[level] = cur; |
bd681513 | 5127 | path->locks[level] = BTRFS_READ_LOCK; |
3f157a2f CM |
5128 | |
5129 | if (btrfs_header_generation(cur) < min_trans) { | |
5130 | ret = 1; | |
5131 | goto out; | |
5132 | } | |
d397712b | 5133 | while (1) { |
3f157a2f CM |
5134 | nritems = btrfs_header_nritems(cur); |
5135 | level = btrfs_header_level(cur); | |
a74b35ec | 5136 | sret = btrfs_bin_search(cur, min_key, level, &slot); |
3f157a2f | 5137 | |
323ac95b CM |
5138 | /* at the lowest level, we're done, setup the path and exit */ |
5139 | if (level == path->lowest_level) { | |
e02119d5 CM |
5140 | if (slot >= nritems) |
5141 | goto find_next_key; | |
3f157a2f CM |
5142 | ret = 0; |
5143 | path->slots[level] = slot; | |
5144 | btrfs_item_key_to_cpu(cur, &found_key, slot); | |
5145 | goto out; | |
5146 | } | |
9652480b Y |
5147 | if (sret && slot > 0) |
5148 | slot--; | |
3f157a2f | 5149 | /* |
de78b51a ES |
5150 | * check this node pointer against the min_trans parameters. |
5151 | * If it is too old, old, skip to the next one. | |
3f157a2f | 5152 | */ |
d397712b | 5153 | while (slot < nritems) { |
3f157a2f | 5154 | u64 gen; |
e02119d5 | 5155 | |
3f157a2f CM |
5156 | gen = btrfs_node_ptr_generation(cur, slot); |
5157 | if (gen < min_trans) { | |
5158 | slot++; | |
5159 | continue; | |
5160 | } | |
de78b51a | 5161 | break; |
3f157a2f | 5162 | } |
e02119d5 | 5163 | find_next_key: |
3f157a2f CM |
5164 | /* |
5165 | * we didn't find a candidate key in this node, walk forward | |
5166 | * and find another one | |
5167 | */ | |
5168 | if (slot >= nritems) { | |
e02119d5 | 5169 | path->slots[level] = slot; |
b4ce94de | 5170 | btrfs_set_path_blocking(path); |
e02119d5 | 5171 | sret = btrfs_find_next_key(root, path, min_key, level, |
de78b51a | 5172 | min_trans); |
e02119d5 | 5173 | if (sret == 0) { |
b3b4aa74 | 5174 | btrfs_release_path(path); |
3f157a2f CM |
5175 | goto again; |
5176 | } else { | |
5177 | goto out; | |
5178 | } | |
5179 | } | |
5180 | /* save our key for returning back */ | |
5181 | btrfs_node_key_to_cpu(cur, &found_key, slot); | |
5182 | path->slots[level] = slot; | |
5183 | if (level == path->lowest_level) { | |
5184 | ret = 0; | |
3f157a2f CM |
5185 | goto out; |
5186 | } | |
b4ce94de | 5187 | btrfs_set_path_blocking(path); |
2ff7e61e | 5188 | cur = read_node_slot(fs_info, cur, slot); |
fb770ae4 LB |
5189 | if (IS_ERR(cur)) { |
5190 | ret = PTR_ERR(cur); | |
5191 | goto out; | |
5192 | } | |
3f157a2f | 5193 | |
bd681513 | 5194 | btrfs_tree_read_lock(cur); |
b4ce94de | 5195 | |
bd681513 | 5196 | path->locks[level - 1] = BTRFS_READ_LOCK; |
3f157a2f | 5197 | path->nodes[level - 1] = cur; |
f7c79f30 | 5198 | unlock_up(path, level, 1, 0, NULL); |
3f157a2f CM |
5199 | } |
5200 | out: | |
f98de9b9 FM |
5201 | path->keep_locks = keep_locks; |
5202 | if (ret == 0) { | |
5203 | btrfs_unlock_up_safe(path, path->lowest_level + 1); | |
5204 | btrfs_set_path_blocking(path); | |
3f157a2f | 5205 | memcpy(min_key, &found_key, sizeof(found_key)); |
f98de9b9 | 5206 | } |
3f157a2f CM |
5207 | return ret; |
5208 | } | |
5209 | ||
2ff7e61e | 5210 | static int tree_move_down(struct btrfs_fs_info *fs_info, |
7069830a | 5211 | struct btrfs_path *path, |
ab6a43e1 | 5212 | int *level) |
7069830a | 5213 | { |
fb770ae4 LB |
5214 | struct extent_buffer *eb; |
5215 | ||
74dd17fb | 5216 | BUG_ON(*level == 0); |
2ff7e61e | 5217 | eb = read_node_slot(fs_info, path->nodes[*level], path->slots[*level]); |
fb770ae4 LB |
5218 | if (IS_ERR(eb)) |
5219 | return PTR_ERR(eb); | |
5220 | ||
5221 | path->nodes[*level - 1] = eb; | |
7069830a AB |
5222 | path->slots[*level - 1] = 0; |
5223 | (*level)--; | |
fb770ae4 | 5224 | return 0; |
7069830a AB |
5225 | } |
5226 | ||
f1e30261 | 5227 | static int tree_move_next_or_upnext(struct btrfs_path *path, |
7069830a AB |
5228 | int *level, int root_level) |
5229 | { | |
5230 | int ret = 0; | |
5231 | int nritems; | |
5232 | nritems = btrfs_header_nritems(path->nodes[*level]); | |
5233 | ||
5234 | path->slots[*level]++; | |
5235 | ||
74dd17fb | 5236 | while (path->slots[*level] >= nritems) { |
7069830a AB |
5237 | if (*level == root_level) |
5238 | return -1; | |
5239 | ||
5240 | /* move upnext */ | |
5241 | path->slots[*level] = 0; | |
5242 | free_extent_buffer(path->nodes[*level]); | |
5243 | path->nodes[*level] = NULL; | |
5244 | (*level)++; | |
5245 | path->slots[*level]++; | |
5246 | ||
5247 | nritems = btrfs_header_nritems(path->nodes[*level]); | |
5248 | ret = 1; | |
5249 | } | |
5250 | return ret; | |
5251 | } | |
5252 | ||
5253 | /* | |
5254 | * Returns 1 if it had to move up and next. 0 is returned if it moved only next | |
5255 | * or down. | |
5256 | */ | |
2ff7e61e | 5257 | static int tree_advance(struct btrfs_fs_info *fs_info, |
7069830a AB |
5258 | struct btrfs_path *path, |
5259 | int *level, int root_level, | |
5260 | int allow_down, | |
5261 | struct btrfs_key *key) | |
5262 | { | |
5263 | int ret; | |
5264 | ||
5265 | if (*level == 0 || !allow_down) { | |
f1e30261 | 5266 | ret = tree_move_next_or_upnext(path, level, root_level); |
7069830a | 5267 | } else { |
ab6a43e1 | 5268 | ret = tree_move_down(fs_info, path, level); |
7069830a AB |
5269 | } |
5270 | if (ret >= 0) { | |
5271 | if (*level == 0) | |
5272 | btrfs_item_key_to_cpu(path->nodes[*level], key, | |
5273 | path->slots[*level]); | |
5274 | else | |
5275 | btrfs_node_key_to_cpu(path->nodes[*level], key, | |
5276 | path->slots[*level]); | |
5277 | } | |
5278 | return ret; | |
5279 | } | |
5280 | ||
2ff7e61e | 5281 | static int tree_compare_item(struct btrfs_path *left_path, |
7069830a AB |
5282 | struct btrfs_path *right_path, |
5283 | char *tmp_buf) | |
5284 | { | |
5285 | int cmp; | |
5286 | int len1, len2; | |
5287 | unsigned long off1, off2; | |
5288 | ||
5289 | len1 = btrfs_item_size_nr(left_path->nodes[0], left_path->slots[0]); | |
5290 | len2 = btrfs_item_size_nr(right_path->nodes[0], right_path->slots[0]); | |
5291 | if (len1 != len2) | |
5292 | return 1; | |
5293 | ||
5294 | off1 = btrfs_item_ptr_offset(left_path->nodes[0], left_path->slots[0]); | |
5295 | off2 = btrfs_item_ptr_offset(right_path->nodes[0], | |
5296 | right_path->slots[0]); | |
5297 | ||
5298 | read_extent_buffer(left_path->nodes[0], tmp_buf, off1, len1); | |
5299 | ||
5300 | cmp = memcmp_extent_buffer(right_path->nodes[0], tmp_buf, off2, len1); | |
5301 | if (cmp) | |
5302 | return 1; | |
5303 | return 0; | |
5304 | } | |
5305 | ||
5306 | #define ADVANCE 1 | |
5307 | #define ADVANCE_ONLY_NEXT -1 | |
5308 | ||
5309 | /* | |
5310 | * This function compares two trees and calls the provided callback for | |
5311 | * every changed/new/deleted item it finds. | |
5312 | * If shared tree blocks are encountered, whole subtrees are skipped, making | |
5313 | * the compare pretty fast on snapshotted subvolumes. | |
5314 | * | |
5315 | * This currently works on commit roots only. As commit roots are read only, | |
5316 | * we don't do any locking. The commit roots are protected with transactions. | |
5317 | * Transactions are ended and rejoined when a commit is tried in between. | |
5318 | * | |
5319 | * This function checks for modifications done to the trees while comparing. | |
5320 | * If it detects a change, it aborts immediately. | |
5321 | */ | |
5322 | int btrfs_compare_trees(struct btrfs_root *left_root, | |
5323 | struct btrfs_root *right_root, | |
5324 | btrfs_changed_cb_t changed_cb, void *ctx) | |
5325 | { | |
0b246afa | 5326 | struct btrfs_fs_info *fs_info = left_root->fs_info; |
7069830a AB |
5327 | int ret; |
5328 | int cmp; | |
7069830a AB |
5329 | struct btrfs_path *left_path = NULL; |
5330 | struct btrfs_path *right_path = NULL; | |
5331 | struct btrfs_key left_key; | |
5332 | struct btrfs_key right_key; | |
5333 | char *tmp_buf = NULL; | |
5334 | int left_root_level; | |
5335 | int right_root_level; | |
5336 | int left_level; | |
5337 | int right_level; | |
5338 | int left_end_reached; | |
5339 | int right_end_reached; | |
5340 | int advance_left; | |
5341 | int advance_right; | |
5342 | u64 left_blockptr; | |
5343 | u64 right_blockptr; | |
6baa4293 FM |
5344 | u64 left_gen; |
5345 | u64 right_gen; | |
7069830a AB |
5346 | |
5347 | left_path = btrfs_alloc_path(); | |
5348 | if (!left_path) { | |
5349 | ret = -ENOMEM; | |
5350 | goto out; | |
5351 | } | |
5352 | right_path = btrfs_alloc_path(); | |
5353 | if (!right_path) { | |
5354 | ret = -ENOMEM; | |
5355 | goto out; | |
5356 | } | |
5357 | ||
752ade68 | 5358 | tmp_buf = kvmalloc(fs_info->nodesize, GFP_KERNEL); |
7069830a | 5359 | if (!tmp_buf) { |
752ade68 MH |
5360 | ret = -ENOMEM; |
5361 | goto out; | |
7069830a AB |
5362 | } |
5363 | ||
5364 | left_path->search_commit_root = 1; | |
5365 | left_path->skip_locking = 1; | |
5366 | right_path->search_commit_root = 1; | |
5367 | right_path->skip_locking = 1; | |
5368 | ||
7069830a AB |
5369 | /* |
5370 | * Strategy: Go to the first items of both trees. Then do | |
5371 | * | |
5372 | * If both trees are at level 0 | |
5373 | * Compare keys of current items | |
5374 | * If left < right treat left item as new, advance left tree | |
5375 | * and repeat | |
5376 | * If left > right treat right item as deleted, advance right tree | |
5377 | * and repeat | |
5378 | * If left == right do deep compare of items, treat as changed if | |
5379 | * needed, advance both trees and repeat | |
5380 | * If both trees are at the same level but not at level 0 | |
5381 | * Compare keys of current nodes/leafs | |
5382 | * If left < right advance left tree and repeat | |
5383 | * If left > right advance right tree and repeat | |
5384 | * If left == right compare blockptrs of the next nodes/leafs | |
5385 | * If they match advance both trees but stay at the same level | |
5386 | * and repeat | |
5387 | * If they don't match advance both trees while allowing to go | |
5388 | * deeper and repeat | |
5389 | * If tree levels are different | |
5390 | * Advance the tree that needs it and repeat | |
5391 | * | |
5392 | * Advancing a tree means: | |
5393 | * If we are at level 0, try to go to the next slot. If that's not | |
5394 | * possible, go one level up and repeat. Stop when we found a level | |
5395 | * where we could go to the next slot. We may at this point be on a | |
5396 | * node or a leaf. | |
5397 | * | |
5398 | * If we are not at level 0 and not on shared tree blocks, go one | |
5399 | * level deeper. | |
5400 | * | |
5401 | * If we are not at level 0 and on shared tree blocks, go one slot to | |
5402 | * the right if possible or go up and right. | |
5403 | */ | |
5404 | ||
0b246afa | 5405 | down_read(&fs_info->commit_root_sem); |
7069830a AB |
5406 | left_level = btrfs_header_level(left_root->commit_root); |
5407 | left_root_level = left_level; | |
6f2f0b39 RK |
5408 | left_path->nodes[left_level] = |
5409 | btrfs_clone_extent_buffer(left_root->commit_root); | |
5410 | if (!left_path->nodes[left_level]) { | |
5411 | up_read(&fs_info->commit_root_sem); | |
5412 | ret = -ENOMEM; | |
5413 | goto out; | |
5414 | } | |
7069830a AB |
5415 | |
5416 | right_level = btrfs_header_level(right_root->commit_root); | |
5417 | right_root_level = right_level; | |
6f2f0b39 RK |
5418 | right_path->nodes[right_level] = |
5419 | btrfs_clone_extent_buffer(right_root->commit_root); | |
5420 | if (!right_path->nodes[right_level]) { | |
5421 | up_read(&fs_info->commit_root_sem); | |
5422 | ret = -ENOMEM; | |
5423 | goto out; | |
5424 | } | |
0b246afa | 5425 | up_read(&fs_info->commit_root_sem); |
7069830a AB |
5426 | |
5427 | if (left_level == 0) | |
5428 | btrfs_item_key_to_cpu(left_path->nodes[left_level], | |
5429 | &left_key, left_path->slots[left_level]); | |
5430 | else | |
5431 | btrfs_node_key_to_cpu(left_path->nodes[left_level], | |
5432 | &left_key, left_path->slots[left_level]); | |
5433 | if (right_level == 0) | |
5434 | btrfs_item_key_to_cpu(right_path->nodes[right_level], | |
5435 | &right_key, right_path->slots[right_level]); | |
5436 | else | |
5437 | btrfs_node_key_to_cpu(right_path->nodes[right_level], | |
5438 | &right_key, right_path->slots[right_level]); | |
5439 | ||
5440 | left_end_reached = right_end_reached = 0; | |
5441 | advance_left = advance_right = 0; | |
5442 | ||
5443 | while (1) { | |
7069830a | 5444 | if (advance_left && !left_end_reached) { |
2ff7e61e | 5445 | ret = tree_advance(fs_info, left_path, &left_level, |
7069830a AB |
5446 | left_root_level, |
5447 | advance_left != ADVANCE_ONLY_NEXT, | |
5448 | &left_key); | |
fb770ae4 | 5449 | if (ret == -1) |
7069830a | 5450 | left_end_reached = ADVANCE; |
fb770ae4 LB |
5451 | else if (ret < 0) |
5452 | goto out; | |
7069830a AB |
5453 | advance_left = 0; |
5454 | } | |
5455 | if (advance_right && !right_end_reached) { | |
2ff7e61e | 5456 | ret = tree_advance(fs_info, right_path, &right_level, |
7069830a AB |
5457 | right_root_level, |
5458 | advance_right != ADVANCE_ONLY_NEXT, | |
5459 | &right_key); | |
fb770ae4 | 5460 | if (ret == -1) |
7069830a | 5461 | right_end_reached = ADVANCE; |
fb770ae4 LB |
5462 | else if (ret < 0) |
5463 | goto out; | |
7069830a AB |
5464 | advance_right = 0; |
5465 | } | |
5466 | ||
5467 | if (left_end_reached && right_end_reached) { | |
5468 | ret = 0; | |
5469 | goto out; | |
5470 | } else if (left_end_reached) { | |
5471 | if (right_level == 0) { | |
ee8c494f | 5472 | ret = changed_cb(left_path, right_path, |
7069830a AB |
5473 | &right_key, |
5474 | BTRFS_COMPARE_TREE_DELETED, | |
5475 | ctx); | |
5476 | if (ret < 0) | |
5477 | goto out; | |
5478 | } | |
5479 | advance_right = ADVANCE; | |
5480 | continue; | |
5481 | } else if (right_end_reached) { | |
5482 | if (left_level == 0) { | |
ee8c494f | 5483 | ret = changed_cb(left_path, right_path, |
7069830a AB |
5484 | &left_key, |
5485 | BTRFS_COMPARE_TREE_NEW, | |
5486 | ctx); | |
5487 | if (ret < 0) | |
5488 | goto out; | |
5489 | } | |
5490 | advance_left = ADVANCE; | |
5491 | continue; | |
5492 | } | |
5493 | ||
5494 | if (left_level == 0 && right_level == 0) { | |
5495 | cmp = btrfs_comp_cpu_keys(&left_key, &right_key); | |
5496 | if (cmp < 0) { | |
ee8c494f | 5497 | ret = changed_cb(left_path, right_path, |
7069830a AB |
5498 | &left_key, |
5499 | BTRFS_COMPARE_TREE_NEW, | |
5500 | ctx); | |
5501 | if (ret < 0) | |
5502 | goto out; | |
5503 | advance_left = ADVANCE; | |
5504 | } else if (cmp > 0) { | |
ee8c494f | 5505 | ret = changed_cb(left_path, right_path, |
7069830a AB |
5506 | &right_key, |
5507 | BTRFS_COMPARE_TREE_DELETED, | |
5508 | ctx); | |
5509 | if (ret < 0) | |
5510 | goto out; | |
5511 | advance_right = ADVANCE; | |
5512 | } else { | |
b99d9a6a | 5513 | enum btrfs_compare_tree_result result; |
ba5e8f2e | 5514 | |
74dd17fb | 5515 | WARN_ON(!extent_buffer_uptodate(left_path->nodes[0])); |
2ff7e61e JM |
5516 | ret = tree_compare_item(left_path, right_path, |
5517 | tmp_buf); | |
ba5e8f2e | 5518 | if (ret) |
b99d9a6a | 5519 | result = BTRFS_COMPARE_TREE_CHANGED; |
ba5e8f2e | 5520 | else |
b99d9a6a | 5521 | result = BTRFS_COMPARE_TREE_SAME; |
ee8c494f | 5522 | ret = changed_cb(left_path, right_path, |
b99d9a6a | 5523 | &left_key, result, ctx); |
ba5e8f2e JB |
5524 | if (ret < 0) |
5525 | goto out; | |
7069830a AB |
5526 | advance_left = ADVANCE; |
5527 | advance_right = ADVANCE; | |
5528 | } | |
5529 | } else if (left_level == right_level) { | |
5530 | cmp = btrfs_comp_cpu_keys(&left_key, &right_key); | |
5531 | if (cmp < 0) { | |
5532 | advance_left = ADVANCE; | |
5533 | } else if (cmp > 0) { | |
5534 | advance_right = ADVANCE; | |
5535 | } else { | |
5536 | left_blockptr = btrfs_node_blockptr( | |
5537 | left_path->nodes[left_level], | |
5538 | left_path->slots[left_level]); | |
5539 | right_blockptr = btrfs_node_blockptr( | |
5540 | right_path->nodes[right_level], | |
5541 | right_path->slots[right_level]); | |
6baa4293 FM |
5542 | left_gen = btrfs_node_ptr_generation( |
5543 | left_path->nodes[left_level], | |
5544 | left_path->slots[left_level]); | |
5545 | right_gen = btrfs_node_ptr_generation( | |
5546 | right_path->nodes[right_level], | |
5547 | right_path->slots[right_level]); | |
5548 | if (left_blockptr == right_blockptr && | |
5549 | left_gen == right_gen) { | |
7069830a AB |
5550 | /* |
5551 | * As we're on a shared block, don't | |
5552 | * allow to go deeper. | |
5553 | */ | |
5554 | advance_left = ADVANCE_ONLY_NEXT; | |
5555 | advance_right = ADVANCE_ONLY_NEXT; | |
5556 | } else { | |
5557 | advance_left = ADVANCE; | |
5558 | advance_right = ADVANCE; | |
5559 | } | |
5560 | } | |
5561 | } else if (left_level < right_level) { | |
5562 | advance_right = ADVANCE; | |
5563 | } else { | |
5564 | advance_left = ADVANCE; | |
5565 | } | |
5566 | } | |
5567 | ||
5568 | out: | |
5569 | btrfs_free_path(left_path); | |
5570 | btrfs_free_path(right_path); | |
8f282f71 | 5571 | kvfree(tmp_buf); |
7069830a AB |
5572 | return ret; |
5573 | } | |
5574 | ||
3f157a2f CM |
5575 | /* |
5576 | * this is similar to btrfs_next_leaf, but does not try to preserve | |
5577 | * and fixup the path. It looks for and returns the next key in the | |
de78b51a | 5578 | * tree based on the current path and the min_trans parameters. |
3f157a2f CM |
5579 | * |
5580 | * 0 is returned if another key is found, < 0 if there are any errors | |
5581 | * and 1 is returned if there are no higher keys in the tree | |
5582 | * | |
5583 | * path->keep_locks should be set to 1 on the search made before | |
5584 | * calling this function. | |
5585 | */ | |
e7a84565 | 5586 | int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path, |
de78b51a | 5587 | struct btrfs_key *key, int level, u64 min_trans) |
e7a84565 | 5588 | { |
e7a84565 CM |
5589 | int slot; |
5590 | struct extent_buffer *c; | |
5591 | ||
934d375b | 5592 | WARN_ON(!path->keep_locks); |
d397712b | 5593 | while (level < BTRFS_MAX_LEVEL) { |
e7a84565 CM |
5594 | if (!path->nodes[level]) |
5595 | return 1; | |
5596 | ||
5597 | slot = path->slots[level] + 1; | |
5598 | c = path->nodes[level]; | |
3f157a2f | 5599 | next: |
e7a84565 | 5600 | if (slot >= btrfs_header_nritems(c)) { |
33c66f43 YZ |
5601 | int ret; |
5602 | int orig_lowest; | |
5603 | struct btrfs_key cur_key; | |
5604 | if (level + 1 >= BTRFS_MAX_LEVEL || | |
5605 | !path->nodes[level + 1]) | |
e7a84565 | 5606 | return 1; |
33c66f43 YZ |
5607 | |
5608 | if (path->locks[level + 1]) { | |
5609 | level++; | |
5610 | continue; | |
5611 | } | |
5612 | ||
5613 | slot = btrfs_header_nritems(c) - 1; | |
5614 | if (level == 0) | |
5615 | btrfs_item_key_to_cpu(c, &cur_key, slot); | |
5616 | else | |
5617 | btrfs_node_key_to_cpu(c, &cur_key, slot); | |
5618 | ||
5619 | orig_lowest = path->lowest_level; | |
b3b4aa74 | 5620 | btrfs_release_path(path); |
33c66f43 YZ |
5621 | path->lowest_level = level; |
5622 | ret = btrfs_search_slot(NULL, root, &cur_key, path, | |
5623 | 0, 0); | |
5624 | path->lowest_level = orig_lowest; | |
5625 | if (ret < 0) | |
5626 | return ret; | |
5627 | ||
5628 | c = path->nodes[level]; | |
5629 | slot = path->slots[level]; | |
5630 | if (ret == 0) | |
5631 | slot++; | |
5632 | goto next; | |
e7a84565 | 5633 | } |
33c66f43 | 5634 | |
e7a84565 CM |
5635 | if (level == 0) |
5636 | btrfs_item_key_to_cpu(c, key, slot); | |
3f157a2f | 5637 | else { |
3f157a2f CM |
5638 | u64 gen = btrfs_node_ptr_generation(c, slot); |
5639 | ||
3f157a2f CM |
5640 | if (gen < min_trans) { |
5641 | slot++; | |
5642 | goto next; | |
5643 | } | |
e7a84565 | 5644 | btrfs_node_key_to_cpu(c, key, slot); |
3f157a2f | 5645 | } |
e7a84565 CM |
5646 | return 0; |
5647 | } | |
5648 | return 1; | |
5649 | } | |
5650 | ||
97571fd0 | 5651 | /* |
925baedd | 5652 | * search the tree again to find a leaf with greater keys |
0f70abe2 CM |
5653 | * returns 0 if it found something or 1 if there are no greater leaves. |
5654 | * returns < 0 on io errors. | |
97571fd0 | 5655 | */ |
234b63a0 | 5656 | int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path) |
3d7806ec JS |
5657 | { |
5658 | return btrfs_next_old_leaf(root, path, 0); | |
5659 | } | |
5660 | ||
5661 | int btrfs_next_old_leaf(struct btrfs_root *root, struct btrfs_path *path, | |
5662 | u64 time_seq) | |
d97e63b6 CM |
5663 | { |
5664 | int slot; | |
8e73f275 | 5665 | int level; |
5f39d397 | 5666 | struct extent_buffer *c; |
8e73f275 | 5667 | struct extent_buffer *next; |
925baedd CM |
5668 | struct btrfs_key key; |
5669 | u32 nritems; | |
5670 | int ret; | |
8e73f275 | 5671 | int old_spinning = path->leave_spinning; |
bd681513 | 5672 | int next_rw_lock = 0; |
925baedd CM |
5673 | |
5674 | nritems = btrfs_header_nritems(path->nodes[0]); | |
d397712b | 5675 | if (nritems == 0) |
925baedd | 5676 | return 1; |
925baedd | 5677 | |
8e73f275 CM |
5678 | btrfs_item_key_to_cpu(path->nodes[0], &key, nritems - 1); |
5679 | again: | |
5680 | level = 1; | |
5681 | next = NULL; | |
bd681513 | 5682 | next_rw_lock = 0; |
b3b4aa74 | 5683 | btrfs_release_path(path); |
8e73f275 | 5684 | |
a2135011 | 5685 | path->keep_locks = 1; |
31533fb2 | 5686 | path->leave_spinning = 1; |
8e73f275 | 5687 | |
3d7806ec JS |
5688 | if (time_seq) |
5689 | ret = btrfs_search_old_slot(root, &key, path, time_seq); | |
5690 | else | |
5691 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); | |
925baedd CM |
5692 | path->keep_locks = 0; |
5693 | ||
5694 | if (ret < 0) | |
5695 | return ret; | |
5696 | ||
a2135011 | 5697 | nritems = btrfs_header_nritems(path->nodes[0]); |
168fd7d2 CM |
5698 | /* |
5699 | * by releasing the path above we dropped all our locks. A balance | |
5700 | * could have added more items next to the key that used to be | |
5701 | * at the very end of the block. So, check again here and | |
5702 | * advance the path if there are now more items available. | |
5703 | */ | |
a2135011 | 5704 | if (nritems > 0 && path->slots[0] < nritems - 1) { |
e457afec YZ |
5705 | if (ret == 0) |
5706 | path->slots[0]++; | |
8e73f275 | 5707 | ret = 0; |
925baedd CM |
5708 | goto done; |
5709 | } | |
0b43e04f LB |
5710 | /* |
5711 | * So the above check misses one case: | |
5712 | * - after releasing the path above, someone has removed the item that | |
5713 | * used to be at the very end of the block, and balance between leafs | |
5714 | * gets another one with bigger key.offset to replace it. | |
5715 | * | |
5716 | * This one should be returned as well, or we can get leaf corruption | |
5717 | * later(esp. in __btrfs_drop_extents()). | |
5718 | * | |
5719 | * And a bit more explanation about this check, | |
5720 | * with ret > 0, the key isn't found, the path points to the slot | |
5721 | * where it should be inserted, so the path->slots[0] item must be the | |
5722 | * bigger one. | |
5723 | */ | |
5724 | if (nritems > 0 && ret > 0 && path->slots[0] == nritems - 1) { | |
5725 | ret = 0; | |
5726 | goto done; | |
5727 | } | |
d97e63b6 | 5728 | |
d397712b | 5729 | while (level < BTRFS_MAX_LEVEL) { |
8e73f275 CM |
5730 | if (!path->nodes[level]) { |
5731 | ret = 1; | |
5732 | goto done; | |
5733 | } | |
5f39d397 | 5734 | |
d97e63b6 CM |
5735 | slot = path->slots[level] + 1; |
5736 | c = path->nodes[level]; | |
5f39d397 | 5737 | if (slot >= btrfs_header_nritems(c)) { |
d97e63b6 | 5738 | level++; |
8e73f275 CM |
5739 | if (level == BTRFS_MAX_LEVEL) { |
5740 | ret = 1; | |
5741 | goto done; | |
5742 | } | |
d97e63b6 CM |
5743 | continue; |
5744 | } | |
5f39d397 | 5745 | |
925baedd | 5746 | if (next) { |
bd681513 | 5747 | btrfs_tree_unlock_rw(next, next_rw_lock); |
5f39d397 | 5748 | free_extent_buffer(next); |
925baedd | 5749 | } |
5f39d397 | 5750 | |
8e73f275 | 5751 | next = c; |
bd681513 | 5752 | next_rw_lock = path->locks[level]; |
d07b8528 | 5753 | ret = read_block_for_search(root, path, &next, level, |
cda79c54 | 5754 | slot, &key); |
8e73f275 CM |
5755 | if (ret == -EAGAIN) |
5756 | goto again; | |
5f39d397 | 5757 | |
76a05b35 | 5758 | if (ret < 0) { |
b3b4aa74 | 5759 | btrfs_release_path(path); |
76a05b35 CM |
5760 | goto done; |
5761 | } | |
5762 | ||
5cd57b2c | 5763 | if (!path->skip_locking) { |
bd681513 | 5764 | ret = btrfs_try_tree_read_lock(next); |
d42244a0 JS |
5765 | if (!ret && time_seq) { |
5766 | /* | |
5767 | * If we don't get the lock, we may be racing | |
5768 | * with push_leaf_left, holding that lock while | |
5769 | * itself waiting for the leaf we've currently | |
5770 | * locked. To solve this situation, we give up | |
5771 | * on our lock and cycle. | |
5772 | */ | |
cf538830 | 5773 | free_extent_buffer(next); |
d42244a0 JS |
5774 | btrfs_release_path(path); |
5775 | cond_resched(); | |
5776 | goto again; | |
5777 | } | |
8e73f275 CM |
5778 | if (!ret) { |
5779 | btrfs_set_path_blocking(path); | |
bd681513 | 5780 | btrfs_tree_read_lock(next); |
8e73f275 | 5781 | } |
31533fb2 | 5782 | next_rw_lock = BTRFS_READ_LOCK; |
5cd57b2c | 5783 | } |
d97e63b6 CM |
5784 | break; |
5785 | } | |
5786 | path->slots[level] = slot; | |
d397712b | 5787 | while (1) { |
d97e63b6 CM |
5788 | level--; |
5789 | c = path->nodes[level]; | |
925baedd | 5790 | if (path->locks[level]) |
bd681513 | 5791 | btrfs_tree_unlock_rw(c, path->locks[level]); |
8e73f275 | 5792 | |
5f39d397 | 5793 | free_extent_buffer(c); |
d97e63b6 CM |
5794 | path->nodes[level] = next; |
5795 | path->slots[level] = 0; | |
a74a4b97 | 5796 | if (!path->skip_locking) |
bd681513 | 5797 | path->locks[level] = next_rw_lock; |
d97e63b6 CM |
5798 | if (!level) |
5799 | break; | |
b4ce94de | 5800 | |
d07b8528 | 5801 | ret = read_block_for_search(root, path, &next, level, |
cda79c54 | 5802 | 0, &key); |
8e73f275 CM |
5803 | if (ret == -EAGAIN) |
5804 | goto again; | |
5805 | ||
76a05b35 | 5806 | if (ret < 0) { |
b3b4aa74 | 5807 | btrfs_release_path(path); |
76a05b35 CM |
5808 | goto done; |
5809 | } | |
5810 | ||
5cd57b2c | 5811 | if (!path->skip_locking) { |
bd681513 | 5812 | ret = btrfs_try_tree_read_lock(next); |
8e73f275 CM |
5813 | if (!ret) { |
5814 | btrfs_set_path_blocking(path); | |
bd681513 | 5815 | btrfs_tree_read_lock(next); |
bd681513 | 5816 | } |
31533fb2 | 5817 | next_rw_lock = BTRFS_READ_LOCK; |
5cd57b2c | 5818 | } |
d97e63b6 | 5819 | } |
8e73f275 | 5820 | ret = 0; |
925baedd | 5821 | done: |
f7c79f30 | 5822 | unlock_up(path, 0, 1, 0, NULL); |
8e73f275 CM |
5823 | path->leave_spinning = old_spinning; |
5824 | if (!old_spinning) | |
5825 | btrfs_set_path_blocking(path); | |
5826 | ||
5827 | return ret; | |
d97e63b6 | 5828 | } |
0b86a832 | 5829 | |
3f157a2f CM |
5830 | /* |
5831 | * this uses btrfs_prev_leaf to walk backwards in the tree, and keeps | |
5832 | * searching until it gets past min_objectid or finds an item of 'type' | |
5833 | * | |
5834 | * returns 0 if something is found, 1 if nothing was found and < 0 on error | |
5835 | */ | |
0b86a832 CM |
5836 | int btrfs_previous_item(struct btrfs_root *root, |
5837 | struct btrfs_path *path, u64 min_objectid, | |
5838 | int type) | |
5839 | { | |
5840 | struct btrfs_key found_key; | |
5841 | struct extent_buffer *leaf; | |
e02119d5 | 5842 | u32 nritems; |
0b86a832 CM |
5843 | int ret; |
5844 | ||
d397712b | 5845 | while (1) { |
0b86a832 | 5846 | if (path->slots[0] == 0) { |
b4ce94de | 5847 | btrfs_set_path_blocking(path); |
0b86a832 CM |
5848 | ret = btrfs_prev_leaf(root, path); |
5849 | if (ret != 0) | |
5850 | return ret; | |
5851 | } else { | |
5852 | path->slots[0]--; | |
5853 | } | |
5854 | leaf = path->nodes[0]; | |
e02119d5 CM |
5855 | nritems = btrfs_header_nritems(leaf); |
5856 | if (nritems == 0) | |
5857 | return 1; | |
5858 | if (path->slots[0] == nritems) | |
5859 | path->slots[0]--; | |
5860 | ||
0b86a832 | 5861 | btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); |
e02119d5 CM |
5862 | if (found_key.objectid < min_objectid) |
5863 | break; | |
0a4eefbb YZ |
5864 | if (found_key.type == type) |
5865 | return 0; | |
e02119d5 CM |
5866 | if (found_key.objectid == min_objectid && |
5867 | found_key.type < type) | |
5868 | break; | |
0b86a832 CM |
5869 | } |
5870 | return 1; | |
5871 | } | |
ade2e0b3 WS |
5872 | |
5873 | /* | |
5874 | * search in extent tree to find a previous Metadata/Data extent item with | |
5875 | * min objecitd. | |
5876 | * | |
5877 | * returns 0 if something is found, 1 if nothing was found and < 0 on error | |
5878 | */ | |
5879 | int btrfs_previous_extent_item(struct btrfs_root *root, | |
5880 | struct btrfs_path *path, u64 min_objectid) | |
5881 | { | |
5882 | struct btrfs_key found_key; | |
5883 | struct extent_buffer *leaf; | |
5884 | u32 nritems; | |
5885 | int ret; | |
5886 | ||
5887 | while (1) { | |
5888 | if (path->slots[0] == 0) { | |
5889 | btrfs_set_path_blocking(path); | |
5890 | ret = btrfs_prev_leaf(root, path); | |
5891 | if (ret != 0) | |
5892 | return ret; | |
5893 | } else { | |
5894 | path->slots[0]--; | |
5895 | } | |
5896 | leaf = path->nodes[0]; | |
5897 | nritems = btrfs_header_nritems(leaf); | |
5898 | if (nritems == 0) | |
5899 | return 1; | |
5900 | if (path->slots[0] == nritems) | |
5901 | path->slots[0]--; | |
5902 | ||
5903 | btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); | |
5904 | if (found_key.objectid < min_objectid) | |
5905 | break; | |
5906 | if (found_key.type == BTRFS_EXTENT_ITEM_KEY || | |
5907 | found_key.type == BTRFS_METADATA_ITEM_KEY) | |
5908 | return 0; | |
5909 | if (found_key.objectid == min_objectid && | |
5910 | found_key.type < BTRFS_EXTENT_ITEM_KEY) | |
5911 | break; | |
5912 | } | |
5913 | return 1; | |
5914 | } |