Commit | Line | Data |
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6cbd5570 CM |
1 | /* |
2 | * Copyright (C) 2007 Oracle. All rights reserved. | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU General Public | |
6 | * License v2 as published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, | |
9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
11 | * General Public License for more details. | |
12 | * | |
13 | * You should have received a copy of the GNU General Public | |
14 | * License along with this program; if not, write to the | |
15 | * Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
16 | * Boston, MA 021110-1307, USA. | |
17 | */ | |
18 | ||
581bb050 LZ |
19 | #include <linux/delay.h> |
20 | #include <linux/kthread.h> | |
21 | #include <linux/pagemap.h> | |
22 | ||
9f5fae2f CM |
23 | #include "ctree.h" |
24 | #include "disk-io.h" | |
581bb050 LZ |
25 | #include "free-space-cache.h" |
26 | #include "inode-map.h" | |
9f5fae2f CM |
27 | #include "transaction.h" |
28 | ||
581bb050 LZ |
29 | static int caching_kthread(void *data) |
30 | { | |
31 | struct btrfs_root *root = data; | |
32 | struct btrfs_fs_info *fs_info = root->fs_info; | |
33 | struct btrfs_free_space_ctl *ctl = root->free_ino_ctl; | |
34 | struct btrfs_key key; | |
35 | struct btrfs_path *path; | |
36 | struct extent_buffer *leaf; | |
37 | u64 last = (u64)-1; | |
38 | int slot; | |
39 | int ret; | |
40 | ||
4b9465cb CM |
41 | if (!btrfs_test_opt(root, INODE_MAP_CACHE)) |
42 | return 0; | |
43 | ||
581bb050 LZ |
44 | path = btrfs_alloc_path(); |
45 | if (!path) | |
46 | return -ENOMEM; | |
47 | ||
48 | /* Since the commit root is read-only, we can safely skip locking. */ | |
49 | path->skip_locking = 1; | |
50 | path->search_commit_root = 1; | |
51 | path->reada = 2; | |
52 | ||
53 | key.objectid = BTRFS_FIRST_FREE_OBJECTID; | |
54 | key.offset = 0; | |
55 | key.type = BTRFS_INODE_ITEM_KEY; | |
56 | again: | |
57 | /* need to make sure the commit_root doesn't disappear */ | |
9e351cc8 | 58 | down_read(&fs_info->commit_root_sem); |
581bb050 LZ |
59 | |
60 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); | |
61 | if (ret < 0) | |
62 | goto out; | |
63 | ||
64 | while (1) { | |
7841cb28 | 65 | if (btrfs_fs_closing(fs_info)) |
581bb050 LZ |
66 | goto out; |
67 | ||
68 | leaf = path->nodes[0]; | |
69 | slot = path->slots[0]; | |
a47d6b70 | 70 | if (slot >= btrfs_header_nritems(leaf)) { |
581bb050 LZ |
71 | ret = btrfs_next_leaf(root, path); |
72 | if (ret < 0) | |
73 | goto out; | |
74 | else if (ret > 0) | |
75 | break; | |
76 | ||
77 | if (need_resched() || | |
78 | btrfs_transaction_in_commit(fs_info)) { | |
79 | leaf = path->nodes[0]; | |
80 | ||
fae7f21c | 81 | if (WARN_ON(btrfs_header_nritems(leaf) == 0)) |
581bb050 | 82 | break; |
581bb050 LZ |
83 | |
84 | /* | |
85 | * Save the key so we can advances forward | |
86 | * in the next search. | |
87 | */ | |
88 | btrfs_item_key_to_cpu(leaf, &key, 0); | |
945d8962 | 89 | btrfs_release_path(path); |
57cdc8db | 90 | root->ino_cache_progress = last; |
9e351cc8 | 91 | up_read(&fs_info->commit_root_sem); |
581bb050 LZ |
92 | schedule_timeout(1); |
93 | goto again; | |
94 | } else | |
95 | continue; | |
96 | } | |
97 | ||
98 | btrfs_item_key_to_cpu(leaf, &key, slot); | |
99 | ||
100 | if (key.type != BTRFS_INODE_ITEM_KEY) | |
101 | goto next; | |
102 | ||
a47d6b70 | 103 | if (key.objectid >= root->highest_objectid) |
581bb050 LZ |
104 | break; |
105 | ||
106 | if (last != (u64)-1 && last + 1 != key.objectid) { | |
107 | __btrfs_add_free_space(ctl, last + 1, | |
108 | key.objectid - last - 1); | |
57cdc8db | 109 | wake_up(&root->ino_cache_wait); |
581bb050 LZ |
110 | } |
111 | ||
112 | last = key.objectid; | |
113 | next: | |
114 | path->slots[0]++; | |
115 | } | |
116 | ||
a47d6b70 | 117 | if (last < root->highest_objectid - 1) { |
581bb050 | 118 | __btrfs_add_free_space(ctl, last + 1, |
a47d6b70 | 119 | root->highest_objectid - last - 1); |
581bb050 LZ |
120 | } |
121 | ||
57cdc8db DS |
122 | spin_lock(&root->ino_cache_lock); |
123 | root->ino_cache_state = BTRFS_CACHE_FINISHED; | |
124 | spin_unlock(&root->ino_cache_lock); | |
581bb050 | 125 | |
57cdc8db | 126 | root->ino_cache_progress = (u64)-1; |
581bb050 LZ |
127 | btrfs_unpin_free_ino(root); |
128 | out: | |
57cdc8db | 129 | wake_up(&root->ino_cache_wait); |
9e351cc8 | 130 | up_read(&fs_info->commit_root_sem); |
581bb050 LZ |
131 | |
132 | btrfs_free_path(path); | |
133 | ||
134 | return ret; | |
135 | } | |
136 | ||
137 | static void start_caching(struct btrfs_root *root) | |
138 | { | |
a47d6b70 | 139 | struct btrfs_free_space_ctl *ctl = root->free_ino_ctl; |
581bb050 | 140 | struct task_struct *tsk; |
82d5902d | 141 | int ret; |
a47d6b70 | 142 | u64 objectid; |
581bb050 | 143 | |
4b9465cb CM |
144 | if (!btrfs_test_opt(root, INODE_MAP_CACHE)) |
145 | return; | |
146 | ||
57cdc8db DS |
147 | spin_lock(&root->ino_cache_lock); |
148 | if (root->ino_cache_state != BTRFS_CACHE_NO) { | |
149 | spin_unlock(&root->ino_cache_lock); | |
581bb050 LZ |
150 | return; |
151 | } | |
152 | ||
57cdc8db DS |
153 | root->ino_cache_state = BTRFS_CACHE_STARTED; |
154 | spin_unlock(&root->ino_cache_lock); | |
581bb050 | 155 | |
82d5902d LZ |
156 | ret = load_free_ino_cache(root->fs_info, root); |
157 | if (ret == 1) { | |
57cdc8db DS |
158 | spin_lock(&root->ino_cache_lock); |
159 | root->ino_cache_state = BTRFS_CACHE_FINISHED; | |
160 | spin_unlock(&root->ino_cache_lock); | |
82d5902d LZ |
161 | return; |
162 | } | |
163 | ||
a47d6b70 LZ |
164 | /* |
165 | * It can be quite time-consuming to fill the cache by searching | |
166 | * through the extent tree, and this can keep ino allocation path | |
167 | * waiting. Therefore at start we quickly find out the highest | |
168 | * inode number and we know we can use inode numbers which fall in | |
169 | * [highest_ino + 1, BTRFS_LAST_FREE_OBJECTID]. | |
170 | */ | |
171 | ret = btrfs_find_free_objectid(root, &objectid); | |
172 | if (!ret && objectid <= BTRFS_LAST_FREE_OBJECTID) { | |
173 | __btrfs_add_free_space(ctl, objectid, | |
174 | BTRFS_LAST_FREE_OBJECTID - objectid + 1); | |
175 | } | |
176 | ||
67a77eb1 | 177 | tsk = kthread_run(caching_kthread, root, "btrfs-ino-cache-%llu", |
581bb050 | 178 | root->root_key.objectid); |
e60efa84 WS |
179 | if (IS_ERR(tsk)) { |
180 | btrfs_warn(root->fs_info, "failed to start inode caching task"); | |
7e1876ac | 181 | btrfs_clear_pending_and_info(root->fs_info, INODE_MAP_CACHE, |
e60efa84 WS |
182 | "disabling inode map caching"); |
183 | } | |
581bb050 LZ |
184 | } |
185 | ||
186 | int btrfs_find_free_ino(struct btrfs_root *root, u64 *objectid) | |
187 | { | |
4b9465cb CM |
188 | if (!btrfs_test_opt(root, INODE_MAP_CACHE)) |
189 | return btrfs_find_free_objectid(root, objectid); | |
190 | ||
581bb050 LZ |
191 | again: |
192 | *objectid = btrfs_find_ino_for_alloc(root); | |
193 | ||
194 | if (*objectid != 0) | |
195 | return 0; | |
196 | ||
197 | start_caching(root); | |
198 | ||
57cdc8db DS |
199 | wait_event(root->ino_cache_wait, |
200 | root->ino_cache_state == BTRFS_CACHE_FINISHED || | |
581bb050 LZ |
201 | root->free_ino_ctl->free_space > 0); |
202 | ||
57cdc8db | 203 | if (root->ino_cache_state == BTRFS_CACHE_FINISHED && |
581bb050 LZ |
204 | root->free_ino_ctl->free_space == 0) |
205 | return -ENOSPC; | |
206 | else | |
207 | goto again; | |
208 | } | |
209 | ||
210 | void btrfs_return_ino(struct btrfs_root *root, u64 objectid) | |
211 | { | |
581bb050 | 212 | struct btrfs_free_space_ctl *pinned = root->free_ino_pinned; |
4b9465cb CM |
213 | |
214 | if (!btrfs_test_opt(root, INODE_MAP_CACHE)) | |
215 | return; | |
581bb050 | 216 | again: |
57cdc8db | 217 | if (root->ino_cache_state == BTRFS_CACHE_FINISHED) { |
1c70d8fb | 218 | __btrfs_add_free_space(pinned, objectid, 1); |
581bb050 | 219 | } else { |
9e351cc8 | 220 | down_write(&root->fs_info->commit_root_sem); |
57cdc8db DS |
221 | spin_lock(&root->ino_cache_lock); |
222 | if (root->ino_cache_state == BTRFS_CACHE_FINISHED) { | |
223 | spin_unlock(&root->ino_cache_lock); | |
9e351cc8 | 224 | up_write(&root->fs_info->commit_root_sem); |
581bb050 LZ |
225 | goto again; |
226 | } | |
57cdc8db | 227 | spin_unlock(&root->ino_cache_lock); |
581bb050 LZ |
228 | |
229 | start_caching(root); | |
230 | ||
1c70d8fb | 231 | __btrfs_add_free_space(pinned, objectid, 1); |
581bb050 | 232 | |
9e351cc8 | 233 | up_write(&root->fs_info->commit_root_sem); |
581bb050 LZ |
234 | } |
235 | } | |
236 | ||
237 | /* | |
57cdc8db DS |
238 | * When a transaction is committed, we'll move those inode numbers which are |
239 | * smaller than root->ino_cache_progress from pinned tree to free_ino tree, and | |
240 | * others will just be dropped, because the commit root we were searching has | |
241 | * changed. | |
581bb050 | 242 | * |
9e351cc8 | 243 | * Must be called with root->fs_info->commit_root_sem held |
581bb050 LZ |
244 | */ |
245 | void btrfs_unpin_free_ino(struct btrfs_root *root) | |
246 | { | |
247 | struct btrfs_free_space_ctl *ctl = root->free_ino_ctl; | |
248 | struct rb_root *rbroot = &root->free_ino_pinned->free_space_offset; | |
249 | struct btrfs_free_space *info; | |
250 | struct rb_node *n; | |
251 | u64 count; | |
252 | ||
4b9465cb CM |
253 | if (!btrfs_test_opt(root, INODE_MAP_CACHE)) |
254 | return; | |
255 | ||
581bb050 LZ |
256 | while (1) { |
257 | n = rb_first(rbroot); | |
258 | if (!n) | |
259 | break; | |
260 | ||
261 | info = rb_entry(n, struct btrfs_free_space, offset_index); | |
79787eaa | 262 | BUG_ON(info->bitmap); /* Logic error */ |
581bb050 | 263 | |
57cdc8db | 264 | if (info->offset > root->ino_cache_progress) |
581bb050 | 265 | goto free; |
57cdc8db DS |
266 | else if (info->offset + info->bytes > root->ino_cache_progress) |
267 | count = root->ino_cache_progress - info->offset + 1; | |
581bb050 LZ |
268 | else |
269 | count = info->bytes; | |
270 | ||
271 | __btrfs_add_free_space(ctl, info->offset, count); | |
272 | free: | |
273 | rb_erase(&info->offset_index, rbroot); | |
274 | kfree(info); | |
275 | } | |
276 | } | |
277 | ||
278 | #define INIT_THRESHOLD (((1024 * 32) / 2) / sizeof(struct btrfs_free_space)) | |
279 | #define INODES_PER_BITMAP (PAGE_CACHE_SIZE * 8) | |
280 | ||
281 | /* | |
282 | * The goal is to keep the memory used by the free_ino tree won't | |
283 | * exceed the memory if we use bitmaps only. | |
284 | */ | |
285 | static void recalculate_thresholds(struct btrfs_free_space_ctl *ctl) | |
286 | { | |
287 | struct btrfs_free_space *info; | |
288 | struct rb_node *n; | |
289 | int max_ino; | |
290 | int max_bitmaps; | |
291 | ||
292 | n = rb_last(&ctl->free_space_offset); | |
293 | if (!n) { | |
294 | ctl->extents_thresh = INIT_THRESHOLD; | |
295 | return; | |
296 | } | |
297 | info = rb_entry(n, struct btrfs_free_space, offset_index); | |
298 | ||
299 | /* | |
300 | * Find the maximum inode number in the filesystem. Note we | |
301 | * ignore the fact that this can be a bitmap, because we are | |
302 | * not doing precise calculation. | |
303 | */ | |
304 | max_ino = info->bytes - 1; | |
305 | ||
306 | max_bitmaps = ALIGN(max_ino, INODES_PER_BITMAP) / INODES_PER_BITMAP; | |
307 | if (max_bitmaps <= ctl->total_bitmaps) { | |
308 | ctl->extents_thresh = 0; | |
309 | return; | |
310 | } | |
311 | ||
312 | ctl->extents_thresh = (max_bitmaps - ctl->total_bitmaps) * | |
313 | PAGE_CACHE_SIZE / sizeof(*info); | |
314 | } | |
315 | ||
316 | /* | |
317 | * We don't fall back to bitmap, if we are below the extents threshold | |
318 | * or this chunk of inode numbers is a big one. | |
319 | */ | |
320 | static bool use_bitmap(struct btrfs_free_space_ctl *ctl, | |
321 | struct btrfs_free_space *info) | |
322 | { | |
323 | if (ctl->free_extents < ctl->extents_thresh || | |
324 | info->bytes > INODES_PER_BITMAP / 10) | |
325 | return false; | |
326 | ||
327 | return true; | |
328 | } | |
329 | ||
330 | static struct btrfs_free_space_op free_ino_op = { | |
331 | .recalc_thresholds = recalculate_thresholds, | |
332 | .use_bitmap = use_bitmap, | |
333 | }; | |
334 | ||
335 | static void pinned_recalc_thresholds(struct btrfs_free_space_ctl *ctl) | |
336 | { | |
337 | } | |
338 | ||
339 | static bool pinned_use_bitmap(struct btrfs_free_space_ctl *ctl, | |
340 | struct btrfs_free_space *info) | |
341 | { | |
342 | /* | |
343 | * We always use extents for two reasons: | |
344 | * | |
345 | * - The pinned tree is only used during the process of caching | |
346 | * work. | |
347 | * - Make code simpler. See btrfs_unpin_free_ino(). | |
348 | */ | |
349 | return false; | |
350 | } | |
351 | ||
352 | static struct btrfs_free_space_op pinned_free_ino_op = { | |
353 | .recalc_thresholds = pinned_recalc_thresholds, | |
354 | .use_bitmap = pinned_use_bitmap, | |
355 | }; | |
356 | ||
357 | void btrfs_init_free_ino_ctl(struct btrfs_root *root) | |
358 | { | |
359 | struct btrfs_free_space_ctl *ctl = root->free_ino_ctl; | |
360 | struct btrfs_free_space_ctl *pinned = root->free_ino_pinned; | |
361 | ||
362 | spin_lock_init(&ctl->tree_lock); | |
363 | ctl->unit = 1; | |
364 | ctl->start = 0; | |
365 | ctl->private = NULL; | |
366 | ctl->op = &free_ino_op; | |
55507ce3 FM |
367 | INIT_LIST_HEAD(&ctl->trimming_ranges); |
368 | mutex_init(&ctl->cache_writeout_mutex); | |
581bb050 LZ |
369 | |
370 | /* | |
371 | * Initially we allow to use 16K of ram to cache chunks of | |
372 | * inode numbers before we resort to bitmaps. This is somewhat | |
373 | * arbitrary, but it will be adjusted in runtime. | |
374 | */ | |
375 | ctl->extents_thresh = INIT_THRESHOLD; | |
376 | ||
377 | spin_lock_init(&pinned->tree_lock); | |
378 | pinned->unit = 1; | |
379 | pinned->start = 0; | |
380 | pinned->private = NULL; | |
381 | pinned->extents_thresh = 0; | |
382 | pinned->op = &pinned_free_ino_op; | |
383 | } | |
384 | ||
82d5902d LZ |
385 | int btrfs_save_ino_cache(struct btrfs_root *root, |
386 | struct btrfs_trans_handle *trans) | |
387 | { | |
388 | struct btrfs_free_space_ctl *ctl = root->free_ino_ctl; | |
389 | struct btrfs_path *path; | |
390 | struct inode *inode; | |
ba38eb4d MX |
391 | struct btrfs_block_rsv *rsv; |
392 | u64 num_bytes; | |
82d5902d LZ |
393 | u64 alloc_hint = 0; |
394 | int ret; | |
395 | int prealloc; | |
396 | bool retry = false; | |
397 | ||
ca456ae2 | 398 | /* only fs tree and subvol/snap needs ino cache */ |
399 | if (root->root_key.objectid != BTRFS_FS_TREE_OBJECTID && | |
400 | (root->root_key.objectid < BTRFS_FIRST_FREE_OBJECTID || | |
401 | root->root_key.objectid > BTRFS_LAST_FREE_OBJECTID)) | |
402 | return 0; | |
403 | ||
d132a538 | 404 | /* Don't save inode cache if we are deleting this root */ |
69e9c6c6 | 405 | if (btrfs_root_refs(&root->root_item) == 0) |
d132a538 JB |
406 | return 0; |
407 | ||
4b9465cb CM |
408 | if (!btrfs_test_opt(root, INODE_MAP_CACHE)) |
409 | return 0; | |
410 | ||
82d5902d LZ |
411 | path = btrfs_alloc_path(); |
412 | if (!path) | |
413 | return -ENOMEM; | |
4b9465cb | 414 | |
ba38eb4d MX |
415 | rsv = trans->block_rsv; |
416 | trans->block_rsv = &root->fs_info->trans_block_rsv; | |
417 | ||
418 | num_bytes = trans->bytes_reserved; | |
419 | /* | |
420 | * 1 item for inode item insertion if need | |
7b61cd92 MX |
421 | * 4 items for inode item update (in the worst case) |
422 | * 1 items for slack space if we need do truncation | |
ba38eb4d MX |
423 | * 1 item for free space object |
424 | * 3 items for pre-allocation | |
425 | */ | |
7b61cd92 | 426 | trans->bytes_reserved = btrfs_calc_trans_metadata_size(root, 10); |
08e007d2 MX |
427 | ret = btrfs_block_rsv_add(root, trans->block_rsv, |
428 | trans->bytes_reserved, | |
429 | BTRFS_RESERVE_NO_FLUSH); | |
ba38eb4d MX |
430 | if (ret) |
431 | goto out; | |
e77266e4 | 432 | trace_btrfs_space_reservation(root->fs_info, "ino_cache", |
2bcc0328 | 433 | trans->transid, trans->bytes_reserved, 1); |
82d5902d LZ |
434 | again: |
435 | inode = lookup_free_ino_inode(root, path); | |
79787eaa | 436 | if (IS_ERR(inode) && (PTR_ERR(inode) != -ENOENT || retry)) { |
82d5902d | 437 | ret = PTR_ERR(inode); |
ba38eb4d | 438 | goto out_release; |
82d5902d LZ |
439 | } |
440 | ||
441 | if (IS_ERR(inode)) { | |
79787eaa | 442 | BUG_ON(retry); /* Logic error */ |
82d5902d LZ |
443 | retry = true; |
444 | ||
445 | ret = create_free_ino_inode(root, trans, path); | |
446 | if (ret) | |
ba38eb4d | 447 | goto out_release; |
82d5902d LZ |
448 | goto again; |
449 | } | |
450 | ||
451 | BTRFS_I(inode)->generation = 0; | |
452 | ret = btrfs_update_inode(trans, root, inode); | |
79787eaa JM |
453 | if (ret) { |
454 | btrfs_abort_transaction(trans, root, ret); | |
455 | goto out_put; | |
456 | } | |
82d5902d LZ |
457 | |
458 | if (i_size_read(inode) > 0) { | |
74514323 | 459 | ret = btrfs_truncate_free_space_cache(root, trans, inode); |
79787eaa | 460 | if (ret) { |
7cfa9e51 MX |
461 | if (ret != -ENOSPC) |
462 | btrfs_abort_transaction(trans, root, ret); | |
82d5902d | 463 | goto out_put; |
79787eaa | 464 | } |
82d5902d LZ |
465 | } |
466 | ||
57cdc8db DS |
467 | spin_lock(&root->ino_cache_lock); |
468 | if (root->ino_cache_state != BTRFS_CACHE_FINISHED) { | |
82d5902d | 469 | ret = -1; |
57cdc8db | 470 | spin_unlock(&root->ino_cache_lock); |
82d5902d LZ |
471 | goto out_put; |
472 | } | |
57cdc8db | 473 | spin_unlock(&root->ino_cache_lock); |
82d5902d LZ |
474 | |
475 | spin_lock(&ctl->tree_lock); | |
476 | prealloc = sizeof(struct btrfs_free_space) * ctl->free_extents; | |
477 | prealloc = ALIGN(prealloc, PAGE_CACHE_SIZE); | |
478 | prealloc += ctl->total_bitmaps * PAGE_CACHE_SIZE; | |
479 | spin_unlock(&ctl->tree_lock); | |
480 | ||
481 | /* Just to make sure we have enough space */ | |
482 | prealloc += 8 * PAGE_CACHE_SIZE; | |
483 | ||
c09544e0 | 484 | ret = btrfs_delalloc_reserve_space(inode, prealloc); |
82d5902d LZ |
485 | if (ret) |
486 | goto out_put; | |
487 | ||
488 | ret = btrfs_prealloc_file_range_trans(inode, trans, 0, 0, prealloc, | |
489 | prealloc, prealloc, &alloc_hint); | |
c09544e0 JB |
490 | if (ret) { |
491 | btrfs_delalloc_release_space(inode, prealloc); | |
82d5902d | 492 | goto out_put; |
c09544e0 | 493 | } |
82d5902d LZ |
494 | btrfs_free_reserved_data_space(inode, prealloc); |
495 | ||
53645a91 | 496 | ret = btrfs_write_out_ino_cache(root, trans, path, inode); |
82d5902d LZ |
497 | out_put: |
498 | iput(inode); | |
ba38eb4d | 499 | out_release: |
e77266e4 | 500 | trace_btrfs_space_reservation(root->fs_info, "ino_cache", |
2bcc0328 | 501 | trans->transid, trans->bytes_reserved, 0); |
ba38eb4d | 502 | btrfs_block_rsv_release(root, trans->block_rsv, trans->bytes_reserved); |
82d5902d | 503 | out: |
ba38eb4d MX |
504 | trans->block_rsv = rsv; |
505 | trans->bytes_reserved = num_bytes; | |
82d5902d LZ |
506 | |
507 | btrfs_free_path(path); | |
508 | return ret; | |
509 | } | |
510 | ||
581bb050 | 511 | static int btrfs_find_highest_objectid(struct btrfs_root *root, u64 *objectid) |
5be6f7f1 CM |
512 | { |
513 | struct btrfs_path *path; | |
514 | int ret; | |
5f39d397 | 515 | struct extent_buffer *l; |
5be6f7f1 | 516 | struct btrfs_key search_key; |
5f39d397 | 517 | struct btrfs_key found_key; |
5be6f7f1 CM |
518 | int slot; |
519 | ||
520 | path = btrfs_alloc_path(); | |
db5b493a TI |
521 | if (!path) |
522 | return -ENOMEM; | |
5be6f7f1 | 523 | |
6527cdbe ZY |
524 | search_key.objectid = BTRFS_LAST_FREE_OBJECTID; |
525 | search_key.type = -1; | |
5be6f7f1 CM |
526 | search_key.offset = (u64)-1; |
527 | ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0); | |
528 | if (ret < 0) | |
529 | goto error; | |
79787eaa | 530 | BUG_ON(ret == 0); /* Corruption */ |
5be6f7f1 CM |
531 | if (path->slots[0] > 0) { |
532 | slot = path->slots[0] - 1; | |
5f39d397 CM |
533 | l = path->nodes[0]; |
534 | btrfs_item_key_to_cpu(l, &found_key, slot); | |
13a8a7c8 YZ |
535 | *objectid = max_t(u64, found_key.objectid, |
536 | BTRFS_FIRST_FREE_OBJECTID - 1); | |
5be6f7f1 | 537 | } else { |
13a8a7c8 | 538 | *objectid = BTRFS_FIRST_FREE_OBJECTID - 1; |
5be6f7f1 CM |
539 | } |
540 | ret = 0; | |
541 | error: | |
542 | btrfs_free_path(path); | |
543 | return ret; | |
544 | } | |
545 | ||
581bb050 | 546 | int btrfs_find_free_objectid(struct btrfs_root *root, u64 *objectid) |
9f5fae2f | 547 | { |
9f5fae2f | 548 | int ret; |
a2135011 | 549 | mutex_lock(&root->objectid_mutex); |
9f5fae2f | 550 | |
13a8a7c8 | 551 | if (unlikely(root->highest_objectid < BTRFS_FIRST_FREE_OBJECTID)) { |
581bb050 LZ |
552 | ret = btrfs_find_highest_objectid(root, |
553 | &root->highest_objectid); | |
13a8a7c8 YZ |
554 | if (ret) |
555 | goto out; | |
556 | } | |
5b21f2ed | 557 | |
13a8a7c8 YZ |
558 | if (unlikely(root->highest_objectid >= BTRFS_LAST_FREE_OBJECTID)) { |
559 | ret = -ENOSPC; | |
560 | goto out; | |
9f5fae2f | 561 | } |
13a8a7c8 YZ |
562 | |
563 | *objectid = ++root->highest_objectid; | |
564 | ret = 0; | |
565 | out: | |
a2135011 | 566 | mutex_unlock(&root->objectid_mutex); |
9f5fae2f CM |
567 | return ret; |
568 | } |