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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 | ||
41 | path = btrfs_alloc_path(); | |
42 | if (!path) | |
43 | return -ENOMEM; | |
44 | ||
45 | /* Since the commit root is read-only, we can safely skip locking. */ | |
46 | path->skip_locking = 1; | |
47 | path->search_commit_root = 1; | |
48 | path->reada = 2; | |
49 | ||
50 | key.objectid = BTRFS_FIRST_FREE_OBJECTID; | |
51 | key.offset = 0; | |
52 | key.type = BTRFS_INODE_ITEM_KEY; | |
53 | again: | |
54 | /* need to make sure the commit_root doesn't disappear */ | |
55 | mutex_lock(&root->fs_commit_mutex); | |
56 | ||
57 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); | |
58 | if (ret < 0) | |
59 | goto out; | |
60 | ||
61 | while (1) { | |
62 | smp_mb(); | |
a47d6b70 | 63 | if (fs_info->closing) |
581bb050 LZ |
64 | goto out; |
65 | ||
66 | leaf = path->nodes[0]; | |
67 | slot = path->slots[0]; | |
a47d6b70 | 68 | if (slot >= btrfs_header_nritems(leaf)) { |
581bb050 LZ |
69 | ret = btrfs_next_leaf(root, path); |
70 | if (ret < 0) | |
71 | goto out; | |
72 | else if (ret > 0) | |
73 | break; | |
74 | ||
75 | if (need_resched() || | |
76 | btrfs_transaction_in_commit(fs_info)) { | |
77 | leaf = path->nodes[0]; | |
78 | ||
79 | if (btrfs_header_nritems(leaf) == 0) { | |
80 | WARN_ON(1); | |
81 | break; | |
82 | } | |
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); |
581bb050 LZ |
90 | root->cache_progress = last; |
91 | mutex_unlock(&root->fs_commit_mutex); | |
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); | |
109 | wake_up(&root->cache_wait); | |
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 | ||
122 | spin_lock(&root->cache_lock); | |
123 | root->cached = BTRFS_CACHE_FINISHED; | |
124 | spin_unlock(&root->cache_lock); | |
125 | ||
126 | root->cache_progress = (u64)-1; | |
127 | btrfs_unpin_free_ino(root); | |
128 | out: | |
129 | wake_up(&root->cache_wait); | |
130 | mutex_unlock(&root->fs_commit_mutex); | |
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 LZ |
143 | |
144 | spin_lock(&root->cache_lock); | |
145 | if (root->cached != BTRFS_CACHE_NO) { | |
146 | spin_unlock(&root->cache_lock); | |
147 | return; | |
148 | } | |
149 | ||
150 | root->cached = BTRFS_CACHE_STARTED; | |
151 | spin_unlock(&root->cache_lock); | |
152 | ||
82d5902d LZ |
153 | ret = load_free_ino_cache(root->fs_info, root); |
154 | if (ret == 1) { | |
155 | spin_lock(&root->cache_lock); | |
156 | root->cached = BTRFS_CACHE_FINISHED; | |
157 | spin_unlock(&root->cache_lock); | |
158 | return; | |
159 | } | |
160 | ||
a47d6b70 LZ |
161 | /* |
162 | * It can be quite time-consuming to fill the cache by searching | |
163 | * through the extent tree, and this can keep ino allocation path | |
164 | * waiting. Therefore at start we quickly find out the highest | |
165 | * inode number and we know we can use inode numbers which fall in | |
166 | * [highest_ino + 1, BTRFS_LAST_FREE_OBJECTID]. | |
167 | */ | |
168 | ret = btrfs_find_free_objectid(root, &objectid); | |
169 | if (!ret && objectid <= BTRFS_LAST_FREE_OBJECTID) { | |
170 | __btrfs_add_free_space(ctl, objectid, | |
171 | BTRFS_LAST_FREE_OBJECTID - objectid + 1); | |
172 | } | |
173 | ||
581bb050 LZ |
174 | tsk = kthread_run(caching_kthread, root, "btrfs-ino-cache-%llu\n", |
175 | root->root_key.objectid); | |
176 | BUG_ON(IS_ERR(tsk)); | |
177 | } | |
178 | ||
179 | int btrfs_find_free_ino(struct btrfs_root *root, u64 *objectid) | |
180 | { | |
181 | again: | |
182 | *objectid = btrfs_find_ino_for_alloc(root); | |
183 | ||
184 | if (*objectid != 0) | |
185 | return 0; | |
186 | ||
187 | start_caching(root); | |
188 | ||
189 | wait_event(root->cache_wait, | |
190 | root->cached == BTRFS_CACHE_FINISHED || | |
191 | root->free_ino_ctl->free_space > 0); | |
192 | ||
193 | if (root->cached == BTRFS_CACHE_FINISHED && | |
194 | root->free_ino_ctl->free_space == 0) | |
195 | return -ENOSPC; | |
196 | else | |
197 | goto again; | |
198 | } | |
199 | ||
200 | void btrfs_return_ino(struct btrfs_root *root, u64 objectid) | |
201 | { | |
202 | struct btrfs_free_space_ctl *ctl = root->free_ino_ctl; | |
203 | struct btrfs_free_space_ctl *pinned = root->free_ino_pinned; | |
204 | again: | |
205 | if (root->cached == BTRFS_CACHE_FINISHED) { | |
206 | __btrfs_add_free_space(ctl, objectid, 1); | |
207 | } else { | |
208 | /* | |
209 | * If we are in the process of caching free ino chunks, | |
210 | * to avoid adding the same inode number to the free_ino | |
211 | * tree twice due to cross transaction, we'll leave it | |
212 | * in the pinned tree until a transaction is committed | |
213 | * or the caching work is done. | |
214 | */ | |
215 | ||
216 | mutex_lock(&root->fs_commit_mutex); | |
217 | spin_lock(&root->cache_lock); | |
218 | if (root->cached == BTRFS_CACHE_FINISHED) { | |
219 | spin_unlock(&root->cache_lock); | |
220 | mutex_unlock(&root->fs_commit_mutex); | |
221 | goto again; | |
222 | } | |
223 | spin_unlock(&root->cache_lock); | |
224 | ||
225 | start_caching(root); | |
226 | ||
a47d6b70 LZ |
227 | if (objectid <= root->cache_progress || |
228 | objectid > root->highest_objectid) | |
581bb050 LZ |
229 | __btrfs_add_free_space(ctl, objectid, 1); |
230 | else | |
231 | __btrfs_add_free_space(pinned, objectid, 1); | |
232 | ||
233 | mutex_unlock(&root->fs_commit_mutex); | |
234 | } | |
235 | } | |
236 | ||
237 | /* | |
238 | * When a transaction is committed, we'll move those inode numbers which | |
239 | * are smaller than root->cache_progress from pinned tree to free_ino tree, | |
240 | * and others will just be dropped, because the commit root we were | |
241 | * searching has changed. | |
242 | * | |
243 | * Must be called with root->fs_commit_mutex held | |
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 | ||
253 | while (1) { | |
254 | n = rb_first(rbroot); | |
255 | if (!n) | |
256 | break; | |
257 | ||
258 | info = rb_entry(n, struct btrfs_free_space, offset_index); | |
259 | BUG_ON(info->bitmap); | |
260 | ||
261 | if (info->offset > root->cache_progress) | |
262 | goto free; | |
263 | else if (info->offset + info->bytes > root->cache_progress) | |
264 | count = root->cache_progress - info->offset + 1; | |
265 | else | |
266 | count = info->bytes; | |
267 | ||
268 | __btrfs_add_free_space(ctl, info->offset, count); | |
269 | free: | |
270 | rb_erase(&info->offset_index, rbroot); | |
271 | kfree(info); | |
272 | } | |
273 | } | |
274 | ||
275 | #define INIT_THRESHOLD (((1024 * 32) / 2) / sizeof(struct btrfs_free_space)) | |
276 | #define INODES_PER_BITMAP (PAGE_CACHE_SIZE * 8) | |
277 | ||
278 | /* | |
279 | * The goal is to keep the memory used by the free_ino tree won't | |
280 | * exceed the memory if we use bitmaps only. | |
281 | */ | |
282 | static void recalculate_thresholds(struct btrfs_free_space_ctl *ctl) | |
283 | { | |
284 | struct btrfs_free_space *info; | |
285 | struct rb_node *n; | |
286 | int max_ino; | |
287 | int max_bitmaps; | |
288 | ||
289 | n = rb_last(&ctl->free_space_offset); | |
290 | if (!n) { | |
291 | ctl->extents_thresh = INIT_THRESHOLD; | |
292 | return; | |
293 | } | |
294 | info = rb_entry(n, struct btrfs_free_space, offset_index); | |
295 | ||
296 | /* | |
297 | * Find the maximum inode number in the filesystem. Note we | |
298 | * ignore the fact that this can be a bitmap, because we are | |
299 | * not doing precise calculation. | |
300 | */ | |
301 | max_ino = info->bytes - 1; | |
302 | ||
303 | max_bitmaps = ALIGN(max_ino, INODES_PER_BITMAP) / INODES_PER_BITMAP; | |
304 | if (max_bitmaps <= ctl->total_bitmaps) { | |
305 | ctl->extents_thresh = 0; | |
306 | return; | |
307 | } | |
308 | ||
309 | ctl->extents_thresh = (max_bitmaps - ctl->total_bitmaps) * | |
310 | PAGE_CACHE_SIZE / sizeof(*info); | |
311 | } | |
312 | ||
313 | /* | |
314 | * We don't fall back to bitmap, if we are below the extents threshold | |
315 | * or this chunk of inode numbers is a big one. | |
316 | */ | |
317 | static bool use_bitmap(struct btrfs_free_space_ctl *ctl, | |
318 | struct btrfs_free_space *info) | |
319 | { | |
320 | if (ctl->free_extents < ctl->extents_thresh || | |
321 | info->bytes > INODES_PER_BITMAP / 10) | |
322 | return false; | |
323 | ||
324 | return true; | |
325 | } | |
326 | ||
327 | static struct btrfs_free_space_op free_ino_op = { | |
328 | .recalc_thresholds = recalculate_thresholds, | |
329 | .use_bitmap = use_bitmap, | |
330 | }; | |
331 | ||
332 | static void pinned_recalc_thresholds(struct btrfs_free_space_ctl *ctl) | |
333 | { | |
334 | } | |
335 | ||
336 | static bool pinned_use_bitmap(struct btrfs_free_space_ctl *ctl, | |
337 | struct btrfs_free_space *info) | |
338 | { | |
339 | /* | |
340 | * We always use extents for two reasons: | |
341 | * | |
342 | * - The pinned tree is only used during the process of caching | |
343 | * work. | |
344 | * - Make code simpler. See btrfs_unpin_free_ino(). | |
345 | */ | |
346 | return false; | |
347 | } | |
348 | ||
349 | static struct btrfs_free_space_op pinned_free_ino_op = { | |
350 | .recalc_thresholds = pinned_recalc_thresholds, | |
351 | .use_bitmap = pinned_use_bitmap, | |
352 | }; | |
353 | ||
354 | void btrfs_init_free_ino_ctl(struct btrfs_root *root) | |
355 | { | |
356 | struct btrfs_free_space_ctl *ctl = root->free_ino_ctl; | |
357 | struct btrfs_free_space_ctl *pinned = root->free_ino_pinned; | |
358 | ||
359 | spin_lock_init(&ctl->tree_lock); | |
360 | ctl->unit = 1; | |
361 | ctl->start = 0; | |
362 | ctl->private = NULL; | |
363 | ctl->op = &free_ino_op; | |
364 | ||
365 | /* | |
366 | * Initially we allow to use 16K of ram to cache chunks of | |
367 | * inode numbers before we resort to bitmaps. This is somewhat | |
368 | * arbitrary, but it will be adjusted in runtime. | |
369 | */ | |
370 | ctl->extents_thresh = INIT_THRESHOLD; | |
371 | ||
372 | spin_lock_init(&pinned->tree_lock); | |
373 | pinned->unit = 1; | |
374 | pinned->start = 0; | |
375 | pinned->private = NULL; | |
376 | pinned->extents_thresh = 0; | |
377 | pinned->op = &pinned_free_ino_op; | |
378 | } | |
379 | ||
82d5902d LZ |
380 | int btrfs_save_ino_cache(struct btrfs_root *root, |
381 | struct btrfs_trans_handle *trans) | |
382 | { | |
383 | struct btrfs_free_space_ctl *ctl = root->free_ino_ctl; | |
384 | struct btrfs_path *path; | |
385 | struct inode *inode; | |
386 | u64 alloc_hint = 0; | |
387 | int ret; | |
388 | int prealloc; | |
389 | bool retry = false; | |
390 | ||
391 | path = btrfs_alloc_path(); | |
392 | if (!path) | |
393 | return -ENOMEM; | |
394 | again: | |
395 | inode = lookup_free_ino_inode(root, path); | |
396 | if (IS_ERR(inode) && PTR_ERR(inode) != -ENOENT) { | |
397 | ret = PTR_ERR(inode); | |
398 | goto out; | |
399 | } | |
400 | ||
401 | if (IS_ERR(inode)) { | |
402 | BUG_ON(retry); | |
403 | retry = true; | |
404 | ||
405 | ret = create_free_ino_inode(root, trans, path); | |
406 | if (ret) | |
407 | goto out; | |
408 | goto again; | |
409 | } | |
410 | ||
411 | BTRFS_I(inode)->generation = 0; | |
412 | ret = btrfs_update_inode(trans, root, inode); | |
413 | WARN_ON(ret); | |
414 | ||
415 | if (i_size_read(inode) > 0) { | |
416 | ret = btrfs_truncate_free_space_cache(root, trans, path, inode); | |
417 | if (ret) | |
418 | goto out_put; | |
419 | } | |
420 | ||
421 | spin_lock(&root->cache_lock); | |
422 | if (root->cached != BTRFS_CACHE_FINISHED) { | |
423 | ret = -1; | |
424 | spin_unlock(&root->cache_lock); | |
425 | goto out_put; | |
426 | } | |
427 | spin_unlock(&root->cache_lock); | |
428 | ||
429 | spin_lock(&ctl->tree_lock); | |
430 | prealloc = sizeof(struct btrfs_free_space) * ctl->free_extents; | |
431 | prealloc = ALIGN(prealloc, PAGE_CACHE_SIZE); | |
432 | prealloc += ctl->total_bitmaps * PAGE_CACHE_SIZE; | |
433 | spin_unlock(&ctl->tree_lock); | |
434 | ||
435 | /* Just to make sure we have enough space */ | |
436 | prealloc += 8 * PAGE_CACHE_SIZE; | |
437 | ||
438 | ret = btrfs_check_data_free_space(inode, prealloc); | |
439 | if (ret) | |
440 | goto out_put; | |
441 | ||
442 | ret = btrfs_prealloc_file_range_trans(inode, trans, 0, 0, prealloc, | |
443 | prealloc, prealloc, &alloc_hint); | |
444 | if (ret) | |
445 | goto out_put; | |
446 | btrfs_free_reserved_data_space(inode, prealloc); | |
447 | ||
448 | out_put: | |
449 | iput(inode); | |
450 | out: | |
451 | if (ret == 0) | |
452 | ret = btrfs_write_out_ino_cache(root, trans, path); | |
453 | ||
454 | btrfs_free_path(path); | |
455 | return ret; | |
456 | } | |
457 | ||
581bb050 | 458 | static int btrfs_find_highest_objectid(struct btrfs_root *root, u64 *objectid) |
5be6f7f1 CM |
459 | { |
460 | struct btrfs_path *path; | |
461 | int ret; | |
5f39d397 | 462 | struct extent_buffer *l; |
5be6f7f1 | 463 | struct btrfs_key search_key; |
5f39d397 | 464 | struct btrfs_key found_key; |
5be6f7f1 CM |
465 | int slot; |
466 | ||
467 | path = btrfs_alloc_path(); | |
db5b493a TI |
468 | if (!path) |
469 | return -ENOMEM; | |
5be6f7f1 | 470 | |
6527cdbe ZY |
471 | search_key.objectid = BTRFS_LAST_FREE_OBJECTID; |
472 | search_key.type = -1; | |
5be6f7f1 CM |
473 | search_key.offset = (u64)-1; |
474 | ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0); | |
475 | if (ret < 0) | |
476 | goto error; | |
477 | BUG_ON(ret == 0); | |
478 | if (path->slots[0] > 0) { | |
479 | slot = path->slots[0] - 1; | |
5f39d397 CM |
480 | l = path->nodes[0]; |
481 | btrfs_item_key_to_cpu(l, &found_key, slot); | |
13a8a7c8 YZ |
482 | *objectid = max_t(u64, found_key.objectid, |
483 | BTRFS_FIRST_FREE_OBJECTID - 1); | |
5be6f7f1 | 484 | } else { |
13a8a7c8 | 485 | *objectid = BTRFS_FIRST_FREE_OBJECTID - 1; |
5be6f7f1 CM |
486 | } |
487 | ret = 0; | |
488 | error: | |
489 | btrfs_free_path(path); | |
490 | return ret; | |
491 | } | |
492 | ||
581bb050 | 493 | int btrfs_find_free_objectid(struct btrfs_root *root, u64 *objectid) |
9f5fae2f | 494 | { |
9f5fae2f | 495 | int ret; |
a2135011 | 496 | mutex_lock(&root->objectid_mutex); |
9f5fae2f | 497 | |
13a8a7c8 | 498 | if (unlikely(root->highest_objectid < BTRFS_FIRST_FREE_OBJECTID)) { |
581bb050 LZ |
499 | ret = btrfs_find_highest_objectid(root, |
500 | &root->highest_objectid); | |
13a8a7c8 YZ |
501 | if (ret) |
502 | goto out; | |
503 | } | |
5b21f2ed | 504 | |
13a8a7c8 YZ |
505 | if (unlikely(root->highest_objectid >= BTRFS_LAST_FREE_OBJECTID)) { |
506 | ret = -ENOSPC; | |
507 | goto out; | |
9f5fae2f | 508 | } |
13a8a7c8 YZ |
509 | |
510 | *objectid = ++root->highest_objectid; | |
511 | ret = 0; | |
512 | out: | |
a2135011 | 513 | mutex_unlock(&root->objectid_mutex); |
9f5fae2f CM |
514 | return ret; |
515 | } |