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a5ed9182 OS |
1 | /* |
2 | * Copyright (C) 2015 Facebook. 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 | ||
19 | #include <linux/kernel.h> | |
20 | #include <linux/vmalloc.h> | |
21 | #include "ctree.h" | |
22 | #include "disk-io.h" | |
23 | #include "locking.h" | |
24 | #include "free-space-tree.h" | |
25 | #include "transaction.h" | |
26 | ||
27 | static int __add_block_group_free_space(struct btrfs_trans_handle *trans, | |
28 | struct btrfs_fs_info *fs_info, | |
29 | struct btrfs_block_group_cache *block_group, | |
30 | struct btrfs_path *path); | |
31 | ||
32 | void set_free_space_tree_thresholds(struct btrfs_block_group_cache *cache) | |
33 | { | |
34 | u32 bitmap_range; | |
35 | size_t bitmap_size; | |
36 | u64 num_bitmaps, total_bitmap_size; | |
37 | ||
38 | /* | |
39 | * We convert to bitmaps when the disk space required for using extents | |
40 | * exceeds that required for using bitmaps. | |
41 | */ | |
42 | bitmap_range = cache->sectorsize * BTRFS_FREE_SPACE_BITMAP_BITS; | |
43 | num_bitmaps = div_u64(cache->key.offset + bitmap_range - 1, | |
44 | bitmap_range); | |
45 | bitmap_size = sizeof(struct btrfs_item) + BTRFS_FREE_SPACE_BITMAP_SIZE; | |
46 | total_bitmap_size = num_bitmaps * bitmap_size; | |
47 | cache->bitmap_high_thresh = div_u64(total_bitmap_size, | |
48 | sizeof(struct btrfs_item)); | |
49 | ||
50 | /* | |
51 | * We allow for a small buffer between the high threshold and low | |
52 | * threshold to avoid thrashing back and forth between the two formats. | |
53 | */ | |
54 | if (cache->bitmap_high_thresh > 100) | |
55 | cache->bitmap_low_thresh = cache->bitmap_high_thresh - 100; | |
56 | else | |
57 | cache->bitmap_low_thresh = 0; | |
58 | } | |
59 | ||
60 | static int add_new_free_space_info(struct btrfs_trans_handle *trans, | |
61 | struct btrfs_fs_info *fs_info, | |
62 | struct btrfs_block_group_cache *block_group, | |
63 | struct btrfs_path *path) | |
64 | { | |
65 | struct btrfs_root *root = fs_info->free_space_root; | |
66 | struct btrfs_free_space_info *info; | |
67 | struct btrfs_key key; | |
68 | struct extent_buffer *leaf; | |
69 | int ret; | |
70 | ||
71 | key.objectid = block_group->key.objectid; | |
72 | key.type = BTRFS_FREE_SPACE_INFO_KEY; | |
73 | key.offset = block_group->key.offset; | |
74 | ||
75 | ret = btrfs_insert_empty_item(trans, root, path, &key, sizeof(*info)); | |
76 | if (ret) | |
77 | goto out; | |
78 | ||
79 | leaf = path->nodes[0]; | |
80 | info = btrfs_item_ptr(leaf, path->slots[0], | |
81 | struct btrfs_free_space_info); | |
82 | btrfs_set_free_space_extent_count(leaf, info, 0); | |
83 | btrfs_set_free_space_flags(leaf, info, 0); | |
84 | btrfs_mark_buffer_dirty(leaf); | |
85 | ||
86 | ret = 0; | |
87 | out: | |
88 | btrfs_release_path(path); | |
89 | return ret; | |
90 | } | |
91 | ||
92 | struct btrfs_free_space_info * | |
93 | search_free_space_info(struct btrfs_trans_handle *trans, | |
94 | struct btrfs_fs_info *fs_info, | |
95 | struct btrfs_block_group_cache *block_group, | |
96 | struct btrfs_path *path, int cow) | |
97 | { | |
98 | struct btrfs_root *root = fs_info->free_space_root; | |
99 | struct btrfs_key key; | |
100 | int ret; | |
101 | ||
102 | key.objectid = block_group->key.objectid; | |
103 | key.type = BTRFS_FREE_SPACE_INFO_KEY; | |
104 | key.offset = block_group->key.offset; | |
105 | ||
106 | ret = btrfs_search_slot(trans, root, &key, path, 0, cow); | |
107 | if (ret < 0) | |
108 | return ERR_PTR(ret); | |
109 | if (ret != 0) { | |
110 | btrfs_warn(fs_info, "missing free space info for %llu\n", | |
111 | block_group->key.objectid); | |
112 | ASSERT(0); | |
113 | return ERR_PTR(-ENOENT); | |
114 | } | |
115 | ||
116 | return btrfs_item_ptr(path->nodes[0], path->slots[0], | |
117 | struct btrfs_free_space_info); | |
118 | } | |
119 | ||
120 | /* | |
121 | * btrfs_search_slot() but we're looking for the greatest key less than the | |
122 | * passed key. | |
123 | */ | |
124 | static int btrfs_search_prev_slot(struct btrfs_trans_handle *trans, | |
125 | struct btrfs_root *root, | |
126 | struct btrfs_key *key, struct btrfs_path *p, | |
127 | int ins_len, int cow) | |
128 | { | |
129 | int ret; | |
130 | ||
131 | ret = btrfs_search_slot(trans, root, key, p, ins_len, cow); | |
132 | if (ret < 0) | |
133 | return ret; | |
134 | ||
135 | if (ret == 0) { | |
136 | ASSERT(0); | |
137 | return -EIO; | |
138 | } | |
139 | ||
140 | if (p->slots[0] == 0) { | |
141 | ASSERT(0); | |
142 | return -EIO; | |
143 | } | |
144 | p->slots[0]--; | |
145 | ||
146 | return 0; | |
147 | } | |
148 | ||
149 | static inline u32 free_space_bitmap_size(u64 size, u32 sectorsize) | |
150 | { | |
151 | return DIV_ROUND_UP((u32)div_u64(size, sectorsize), BITS_PER_BYTE); | |
152 | } | |
153 | ||
154 | static unsigned long *alloc_bitmap(u32 bitmap_size) | |
155 | { | |
79b134a2 DS |
156 | void *mem; |
157 | ||
158 | /* | |
159 | * The allocation size varies, observed numbers were < 4K up to 16K. | |
160 | * Using vmalloc unconditionally would be too heavy, we'll try | |
161 | * contiguous allocations first. | |
162 | */ | |
163 | if (bitmap_size <= PAGE_SIZE) | |
164 | return kzalloc(bitmap_size, GFP_NOFS); | |
165 | ||
e1c0ebad | 166 | mem = kzalloc(bitmap_size, GFP_NOFS | __GFP_NOWARN); |
79b134a2 DS |
167 | if (mem) |
168 | return mem; | |
169 | ||
a5ed9182 OS |
170 | return __vmalloc(bitmap_size, GFP_NOFS | __GFP_HIGHMEM | __GFP_ZERO, |
171 | PAGE_KERNEL); | |
172 | } | |
173 | ||
174 | int convert_free_space_to_bitmaps(struct btrfs_trans_handle *trans, | |
175 | struct btrfs_fs_info *fs_info, | |
176 | struct btrfs_block_group_cache *block_group, | |
177 | struct btrfs_path *path) | |
178 | { | |
179 | struct btrfs_root *root = fs_info->free_space_root; | |
180 | struct btrfs_free_space_info *info; | |
181 | struct btrfs_key key, found_key; | |
182 | struct extent_buffer *leaf; | |
183 | unsigned long *bitmap; | |
184 | char *bitmap_cursor; | |
185 | u64 start, end; | |
186 | u64 bitmap_range, i; | |
187 | u32 bitmap_size, flags, expected_extent_count; | |
188 | u32 extent_count = 0; | |
189 | int done = 0, nr; | |
190 | int ret; | |
191 | ||
192 | bitmap_size = free_space_bitmap_size(block_group->key.offset, | |
193 | block_group->sectorsize); | |
194 | bitmap = alloc_bitmap(bitmap_size); | |
195 | if (!bitmap) { | |
196 | ret = -ENOMEM; | |
197 | goto out; | |
198 | } | |
199 | ||
200 | start = block_group->key.objectid; | |
201 | end = block_group->key.objectid + block_group->key.offset; | |
202 | ||
203 | key.objectid = end - 1; | |
204 | key.type = (u8)-1; | |
205 | key.offset = (u64)-1; | |
206 | ||
207 | while (!done) { | |
208 | ret = btrfs_search_prev_slot(trans, root, &key, path, -1, 1); | |
209 | if (ret) | |
210 | goto out; | |
211 | ||
212 | leaf = path->nodes[0]; | |
213 | nr = 0; | |
214 | path->slots[0]++; | |
215 | while (path->slots[0] > 0) { | |
216 | btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0] - 1); | |
217 | ||
218 | if (found_key.type == BTRFS_FREE_SPACE_INFO_KEY) { | |
219 | ASSERT(found_key.objectid == block_group->key.objectid); | |
220 | ASSERT(found_key.offset == block_group->key.offset); | |
221 | done = 1; | |
222 | break; | |
223 | } else if (found_key.type == BTRFS_FREE_SPACE_EXTENT_KEY) { | |
224 | u64 first, last; | |
225 | ||
226 | ASSERT(found_key.objectid >= start); | |
227 | ASSERT(found_key.objectid < end); | |
228 | ASSERT(found_key.objectid + found_key.offset <= end); | |
229 | ||
230 | first = div_u64(found_key.objectid - start, | |
231 | block_group->sectorsize); | |
232 | last = div_u64(found_key.objectid + found_key.offset - start, | |
233 | block_group->sectorsize); | |
234 | bitmap_set(bitmap, first, last - first); | |
235 | ||
236 | extent_count++; | |
237 | nr++; | |
238 | path->slots[0]--; | |
239 | } else { | |
240 | ASSERT(0); | |
241 | } | |
242 | } | |
243 | ||
244 | ret = btrfs_del_items(trans, root, path, path->slots[0], nr); | |
245 | if (ret) | |
246 | goto out; | |
247 | btrfs_release_path(path); | |
248 | } | |
249 | ||
250 | info = search_free_space_info(trans, fs_info, block_group, path, 1); | |
251 | if (IS_ERR(info)) { | |
252 | ret = PTR_ERR(info); | |
253 | goto out; | |
254 | } | |
255 | leaf = path->nodes[0]; | |
256 | flags = btrfs_free_space_flags(leaf, info); | |
257 | flags |= BTRFS_FREE_SPACE_USING_BITMAPS; | |
258 | btrfs_set_free_space_flags(leaf, info, flags); | |
259 | expected_extent_count = btrfs_free_space_extent_count(leaf, info); | |
260 | btrfs_mark_buffer_dirty(leaf); | |
261 | btrfs_release_path(path); | |
262 | ||
263 | if (extent_count != expected_extent_count) { | |
264 | btrfs_err(fs_info, "incorrect extent count for %llu; counted %u, expected %u", | |
265 | block_group->key.objectid, extent_count, | |
266 | expected_extent_count); | |
267 | ASSERT(0); | |
268 | ret = -EIO; | |
269 | goto out; | |
270 | } | |
271 | ||
272 | bitmap_cursor = (char *)bitmap; | |
273 | bitmap_range = block_group->sectorsize * BTRFS_FREE_SPACE_BITMAP_BITS; | |
274 | i = start; | |
275 | while (i < end) { | |
276 | unsigned long ptr; | |
277 | u64 extent_size; | |
278 | u32 data_size; | |
279 | ||
280 | extent_size = min(end - i, bitmap_range); | |
281 | data_size = free_space_bitmap_size(extent_size, | |
282 | block_group->sectorsize); | |
283 | ||
284 | key.objectid = i; | |
285 | key.type = BTRFS_FREE_SPACE_BITMAP_KEY; | |
286 | key.offset = extent_size; | |
287 | ||
288 | ret = btrfs_insert_empty_item(trans, root, path, &key, | |
289 | data_size); | |
290 | if (ret) | |
291 | goto out; | |
292 | ||
293 | leaf = path->nodes[0]; | |
294 | ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); | |
295 | write_extent_buffer(leaf, bitmap_cursor, ptr, | |
296 | data_size); | |
297 | btrfs_mark_buffer_dirty(leaf); | |
298 | btrfs_release_path(path); | |
299 | ||
300 | i += extent_size; | |
301 | bitmap_cursor += data_size; | |
302 | } | |
303 | ||
304 | ret = 0; | |
305 | out: | |
79b134a2 | 306 | kvfree(bitmap); |
a5ed9182 OS |
307 | if (ret) |
308 | btrfs_abort_transaction(trans, root, ret); | |
309 | return ret; | |
310 | } | |
311 | ||
312 | int convert_free_space_to_extents(struct btrfs_trans_handle *trans, | |
313 | struct btrfs_fs_info *fs_info, | |
314 | struct btrfs_block_group_cache *block_group, | |
315 | struct btrfs_path *path) | |
316 | { | |
317 | struct btrfs_root *root = fs_info->free_space_root; | |
318 | struct btrfs_free_space_info *info; | |
319 | struct btrfs_key key, found_key; | |
320 | struct extent_buffer *leaf; | |
321 | unsigned long *bitmap; | |
322 | u64 start, end; | |
323 | /* Initialize to silence GCC. */ | |
324 | u64 extent_start = 0; | |
325 | u64 offset; | |
326 | u32 bitmap_size, flags, expected_extent_count; | |
327 | int prev_bit = 0, bit, bitnr; | |
328 | u32 extent_count = 0; | |
329 | int done = 0, nr; | |
330 | int ret; | |
331 | ||
332 | bitmap_size = free_space_bitmap_size(block_group->key.offset, | |
333 | block_group->sectorsize); | |
334 | bitmap = alloc_bitmap(bitmap_size); | |
335 | if (!bitmap) { | |
336 | ret = -ENOMEM; | |
337 | goto out; | |
338 | } | |
339 | ||
340 | start = block_group->key.objectid; | |
341 | end = block_group->key.objectid + block_group->key.offset; | |
342 | ||
343 | key.objectid = end - 1; | |
344 | key.type = (u8)-1; | |
345 | key.offset = (u64)-1; | |
346 | ||
347 | while (!done) { | |
348 | ret = btrfs_search_prev_slot(trans, root, &key, path, -1, 1); | |
349 | if (ret) | |
350 | goto out; | |
351 | ||
352 | leaf = path->nodes[0]; | |
353 | nr = 0; | |
354 | path->slots[0]++; | |
355 | while (path->slots[0] > 0) { | |
356 | btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0] - 1); | |
357 | ||
358 | if (found_key.type == BTRFS_FREE_SPACE_INFO_KEY) { | |
359 | ASSERT(found_key.objectid == block_group->key.objectid); | |
360 | ASSERT(found_key.offset == block_group->key.offset); | |
361 | done = 1; | |
362 | break; | |
363 | } else if (found_key.type == BTRFS_FREE_SPACE_BITMAP_KEY) { | |
364 | unsigned long ptr; | |
365 | char *bitmap_cursor; | |
366 | u32 bitmap_pos, data_size; | |
367 | ||
368 | ASSERT(found_key.objectid >= start); | |
369 | ASSERT(found_key.objectid < end); | |
370 | ASSERT(found_key.objectid + found_key.offset <= end); | |
371 | ||
372 | bitmap_pos = div_u64(found_key.objectid - start, | |
373 | block_group->sectorsize * | |
374 | BITS_PER_BYTE); | |
375 | bitmap_cursor = ((char *)bitmap) + bitmap_pos; | |
376 | data_size = free_space_bitmap_size(found_key.offset, | |
377 | block_group->sectorsize); | |
378 | ||
379 | ptr = btrfs_item_ptr_offset(leaf, path->slots[0] - 1); | |
380 | read_extent_buffer(leaf, bitmap_cursor, ptr, | |
381 | data_size); | |
382 | ||
383 | nr++; | |
384 | path->slots[0]--; | |
385 | } else { | |
386 | ASSERT(0); | |
387 | } | |
388 | } | |
389 | ||
390 | ret = btrfs_del_items(trans, root, path, path->slots[0], nr); | |
391 | if (ret) | |
392 | goto out; | |
393 | btrfs_release_path(path); | |
394 | } | |
395 | ||
396 | info = search_free_space_info(trans, fs_info, block_group, path, 1); | |
397 | if (IS_ERR(info)) { | |
398 | ret = PTR_ERR(info); | |
399 | goto out; | |
400 | } | |
401 | leaf = path->nodes[0]; | |
402 | flags = btrfs_free_space_flags(leaf, info); | |
403 | flags &= ~BTRFS_FREE_SPACE_USING_BITMAPS; | |
404 | btrfs_set_free_space_flags(leaf, info, flags); | |
405 | expected_extent_count = btrfs_free_space_extent_count(leaf, info); | |
406 | btrfs_mark_buffer_dirty(leaf); | |
407 | btrfs_release_path(path); | |
408 | ||
409 | offset = start; | |
410 | bitnr = 0; | |
411 | while (offset < end) { | |
412 | bit = !!test_bit(bitnr, bitmap); | |
413 | if (prev_bit == 0 && bit == 1) { | |
414 | extent_start = offset; | |
415 | } else if (prev_bit == 1 && bit == 0) { | |
416 | key.objectid = extent_start; | |
417 | key.type = BTRFS_FREE_SPACE_EXTENT_KEY; | |
418 | key.offset = offset - extent_start; | |
419 | ||
420 | ret = btrfs_insert_empty_item(trans, root, path, &key, 0); | |
421 | if (ret) | |
422 | goto out; | |
423 | btrfs_release_path(path); | |
424 | ||
425 | extent_count++; | |
426 | } | |
427 | prev_bit = bit; | |
428 | offset += block_group->sectorsize; | |
429 | bitnr++; | |
430 | } | |
431 | if (prev_bit == 1) { | |
432 | key.objectid = extent_start; | |
433 | key.type = BTRFS_FREE_SPACE_EXTENT_KEY; | |
434 | key.offset = end - extent_start; | |
435 | ||
436 | ret = btrfs_insert_empty_item(trans, root, path, &key, 0); | |
437 | if (ret) | |
438 | goto out; | |
439 | btrfs_release_path(path); | |
440 | ||
441 | extent_count++; | |
442 | } | |
443 | ||
444 | if (extent_count != expected_extent_count) { | |
445 | btrfs_err(fs_info, "incorrect extent count for %llu; counted %u, expected %u", | |
446 | block_group->key.objectid, extent_count, | |
447 | expected_extent_count); | |
448 | ASSERT(0); | |
449 | ret = -EIO; | |
450 | goto out; | |
451 | } | |
452 | ||
453 | ret = 0; | |
454 | out: | |
79b134a2 | 455 | kvfree(bitmap); |
a5ed9182 OS |
456 | if (ret) |
457 | btrfs_abort_transaction(trans, root, ret); | |
458 | return ret; | |
459 | } | |
460 | ||
461 | static int update_free_space_extent_count(struct btrfs_trans_handle *trans, | |
462 | struct btrfs_fs_info *fs_info, | |
463 | struct btrfs_block_group_cache *block_group, | |
464 | struct btrfs_path *path, | |
465 | int new_extents) | |
466 | { | |
467 | struct btrfs_free_space_info *info; | |
468 | u32 flags; | |
469 | u32 extent_count; | |
470 | int ret = 0; | |
471 | ||
472 | if (new_extents == 0) | |
473 | return 0; | |
474 | ||
475 | info = search_free_space_info(trans, fs_info, block_group, path, 1); | |
476 | if (IS_ERR(info)) { | |
477 | ret = PTR_ERR(info); | |
478 | goto out; | |
479 | } | |
480 | flags = btrfs_free_space_flags(path->nodes[0], info); | |
481 | extent_count = btrfs_free_space_extent_count(path->nodes[0], info); | |
482 | ||
483 | extent_count += new_extents; | |
484 | btrfs_set_free_space_extent_count(path->nodes[0], info, extent_count); | |
485 | btrfs_mark_buffer_dirty(path->nodes[0]); | |
486 | btrfs_release_path(path); | |
487 | ||
488 | if (!(flags & BTRFS_FREE_SPACE_USING_BITMAPS) && | |
489 | extent_count > block_group->bitmap_high_thresh) { | |
490 | ret = convert_free_space_to_bitmaps(trans, fs_info, block_group, | |
491 | path); | |
492 | } else if ((flags & BTRFS_FREE_SPACE_USING_BITMAPS) && | |
493 | extent_count < block_group->bitmap_low_thresh) { | |
494 | ret = convert_free_space_to_extents(trans, fs_info, block_group, | |
495 | path); | |
496 | } | |
497 | ||
498 | out: | |
499 | return ret; | |
500 | } | |
501 | ||
502 | int free_space_test_bit(struct btrfs_block_group_cache *block_group, | |
503 | struct btrfs_path *path, u64 offset) | |
504 | { | |
505 | struct extent_buffer *leaf; | |
506 | struct btrfs_key key; | |
507 | u64 found_start, found_end; | |
508 | unsigned long ptr, i; | |
509 | ||
510 | leaf = path->nodes[0]; | |
511 | btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); | |
512 | ASSERT(key.type == BTRFS_FREE_SPACE_BITMAP_KEY); | |
513 | ||
514 | found_start = key.objectid; | |
515 | found_end = key.objectid + key.offset; | |
516 | ASSERT(offset >= found_start && offset < found_end); | |
517 | ||
518 | ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); | |
519 | i = div_u64(offset - found_start, block_group->sectorsize); | |
520 | return !!extent_buffer_test_bit(leaf, ptr, i); | |
521 | } | |
522 | ||
523 | static void free_space_set_bits(struct btrfs_block_group_cache *block_group, | |
524 | struct btrfs_path *path, u64 *start, u64 *size, | |
525 | int bit) | |
526 | { | |
527 | struct extent_buffer *leaf; | |
528 | struct btrfs_key key; | |
529 | u64 end = *start + *size; | |
530 | u64 found_start, found_end; | |
531 | unsigned long ptr, first, last; | |
532 | ||
533 | leaf = path->nodes[0]; | |
534 | btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); | |
535 | ASSERT(key.type == BTRFS_FREE_SPACE_BITMAP_KEY); | |
536 | ||
537 | found_start = key.objectid; | |
538 | found_end = key.objectid + key.offset; | |
539 | ASSERT(*start >= found_start && *start < found_end); | |
540 | ASSERT(end > found_start); | |
541 | ||
542 | if (end > found_end) | |
543 | end = found_end; | |
544 | ||
545 | ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); | |
546 | first = div_u64(*start - found_start, block_group->sectorsize); | |
547 | last = div_u64(end - found_start, block_group->sectorsize); | |
548 | if (bit) | |
549 | extent_buffer_bitmap_set(leaf, ptr, first, last - first); | |
550 | else | |
551 | extent_buffer_bitmap_clear(leaf, ptr, first, last - first); | |
552 | btrfs_mark_buffer_dirty(leaf); | |
553 | ||
554 | *size -= end - *start; | |
555 | *start = end; | |
556 | } | |
557 | ||
558 | /* | |
559 | * We can't use btrfs_next_item() in modify_free_space_bitmap() because | |
560 | * btrfs_next_leaf() doesn't get the path for writing. We can forgo the fancy | |
561 | * tree walking in btrfs_next_leaf() anyways because we know exactly what we're | |
562 | * looking for. | |
563 | */ | |
564 | static int free_space_next_bitmap(struct btrfs_trans_handle *trans, | |
565 | struct btrfs_root *root, struct btrfs_path *p) | |
566 | { | |
567 | struct btrfs_key key; | |
568 | ||
569 | if (p->slots[0] + 1 < btrfs_header_nritems(p->nodes[0])) { | |
570 | p->slots[0]++; | |
571 | return 0; | |
572 | } | |
573 | ||
574 | btrfs_item_key_to_cpu(p->nodes[0], &key, p->slots[0]); | |
575 | btrfs_release_path(p); | |
576 | ||
577 | key.objectid += key.offset; | |
578 | key.type = (u8)-1; | |
579 | key.offset = (u64)-1; | |
580 | ||
581 | return btrfs_search_prev_slot(trans, root, &key, p, 0, 1); | |
582 | } | |
583 | ||
584 | /* | |
585 | * If remove is 1, then we are removing free space, thus clearing bits in the | |
586 | * bitmap. If remove is 0, then we are adding free space, thus setting bits in | |
587 | * the bitmap. | |
588 | */ | |
589 | static int modify_free_space_bitmap(struct btrfs_trans_handle *trans, | |
590 | struct btrfs_fs_info *fs_info, | |
591 | struct btrfs_block_group_cache *block_group, | |
592 | struct btrfs_path *path, | |
593 | u64 start, u64 size, int remove) | |
594 | { | |
595 | struct btrfs_root *root = fs_info->free_space_root; | |
596 | struct btrfs_key key; | |
597 | u64 end = start + size; | |
598 | u64 cur_start, cur_size; | |
599 | int prev_bit, next_bit; | |
600 | int new_extents; | |
601 | int ret; | |
602 | ||
603 | /* | |
604 | * Read the bit for the block immediately before the extent of space if | |
605 | * that block is within the block group. | |
606 | */ | |
607 | if (start > block_group->key.objectid) { | |
608 | u64 prev_block = start - block_group->sectorsize; | |
609 | ||
610 | key.objectid = prev_block; | |
611 | key.type = (u8)-1; | |
612 | key.offset = (u64)-1; | |
613 | ||
614 | ret = btrfs_search_prev_slot(trans, root, &key, path, 0, 1); | |
615 | if (ret) | |
616 | goto out; | |
617 | ||
618 | prev_bit = free_space_test_bit(block_group, path, prev_block); | |
619 | ||
620 | /* The previous block may have been in the previous bitmap. */ | |
621 | btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); | |
622 | if (start >= key.objectid + key.offset) { | |
623 | ret = free_space_next_bitmap(trans, root, path); | |
624 | if (ret) | |
625 | goto out; | |
626 | } | |
627 | } else { | |
628 | key.objectid = start; | |
629 | key.type = (u8)-1; | |
630 | key.offset = (u64)-1; | |
631 | ||
632 | ret = btrfs_search_prev_slot(trans, root, &key, path, 0, 1); | |
633 | if (ret) | |
634 | goto out; | |
635 | ||
636 | prev_bit = -1; | |
637 | } | |
638 | ||
639 | /* | |
640 | * Iterate over all of the bitmaps overlapped by the extent of space, | |
641 | * clearing/setting bits as required. | |
642 | */ | |
643 | cur_start = start; | |
644 | cur_size = size; | |
645 | while (1) { | |
646 | free_space_set_bits(block_group, path, &cur_start, &cur_size, | |
647 | !remove); | |
648 | if (cur_size == 0) | |
649 | break; | |
650 | ret = free_space_next_bitmap(trans, root, path); | |
651 | if (ret) | |
652 | goto out; | |
653 | } | |
654 | ||
655 | /* | |
656 | * Read the bit for the block immediately after the extent of space if | |
657 | * that block is within the block group. | |
658 | */ | |
659 | if (end < block_group->key.objectid + block_group->key.offset) { | |
660 | /* The next block may be in the next bitmap. */ | |
661 | btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); | |
662 | if (end >= key.objectid + key.offset) { | |
663 | ret = free_space_next_bitmap(trans, root, path); | |
664 | if (ret) | |
665 | goto out; | |
666 | } | |
667 | ||
668 | next_bit = free_space_test_bit(block_group, path, end); | |
669 | } else { | |
670 | next_bit = -1; | |
671 | } | |
672 | ||
673 | if (remove) { | |
674 | new_extents = -1; | |
675 | if (prev_bit == 1) { | |
676 | /* Leftover on the left. */ | |
677 | new_extents++; | |
678 | } | |
679 | if (next_bit == 1) { | |
680 | /* Leftover on the right. */ | |
681 | new_extents++; | |
682 | } | |
683 | } else { | |
684 | new_extents = 1; | |
685 | if (prev_bit == 1) { | |
686 | /* Merging with neighbor on the left. */ | |
687 | new_extents--; | |
688 | } | |
689 | if (next_bit == 1) { | |
690 | /* Merging with neighbor on the right. */ | |
691 | new_extents--; | |
692 | } | |
693 | } | |
694 | ||
695 | btrfs_release_path(path); | |
696 | ret = update_free_space_extent_count(trans, fs_info, block_group, path, | |
697 | new_extents); | |
698 | ||
699 | out: | |
700 | return ret; | |
701 | } | |
702 | ||
703 | static int remove_free_space_extent(struct btrfs_trans_handle *trans, | |
704 | struct btrfs_fs_info *fs_info, | |
705 | struct btrfs_block_group_cache *block_group, | |
706 | struct btrfs_path *path, | |
707 | u64 start, u64 size) | |
708 | { | |
709 | struct btrfs_root *root = fs_info->free_space_root; | |
710 | struct btrfs_key key; | |
711 | u64 found_start, found_end; | |
712 | u64 end = start + size; | |
713 | int new_extents = -1; | |
714 | int ret; | |
715 | ||
716 | key.objectid = start; | |
717 | key.type = (u8)-1; | |
718 | key.offset = (u64)-1; | |
719 | ||
720 | ret = btrfs_search_prev_slot(trans, root, &key, path, -1, 1); | |
721 | if (ret) | |
722 | goto out; | |
723 | ||
724 | btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); | |
725 | ||
726 | ASSERT(key.type == BTRFS_FREE_SPACE_EXTENT_KEY); | |
727 | ||
728 | found_start = key.objectid; | |
729 | found_end = key.objectid + key.offset; | |
730 | ASSERT(start >= found_start && end <= found_end); | |
731 | ||
732 | /* | |
733 | * Okay, now that we've found the free space extent which contains the | |
734 | * free space that we are removing, there are four cases: | |
735 | * | |
736 | * 1. We're using the whole extent: delete the key we found and | |
737 | * decrement the free space extent count. | |
738 | * 2. We are using part of the extent starting at the beginning: delete | |
739 | * the key we found and insert a new key representing the leftover at | |
740 | * the end. There is no net change in the number of extents. | |
741 | * 3. We are using part of the extent ending at the end: delete the key | |
742 | * we found and insert a new key representing the leftover at the | |
743 | * beginning. There is no net change in the number of extents. | |
744 | * 4. We are using part of the extent in the middle: delete the key we | |
745 | * found and insert two new keys representing the leftovers on each | |
746 | * side. Where we used to have one extent, we now have two, so increment | |
747 | * the extent count. We may need to convert the block group to bitmaps | |
748 | * as a result. | |
749 | */ | |
750 | ||
751 | /* Delete the existing key (cases 1-4). */ | |
752 | ret = btrfs_del_item(trans, root, path); | |
753 | if (ret) | |
754 | goto out; | |
755 | ||
756 | /* Add a key for leftovers at the beginning (cases 3 and 4). */ | |
757 | if (start > found_start) { | |
758 | key.objectid = found_start; | |
759 | key.type = BTRFS_FREE_SPACE_EXTENT_KEY; | |
760 | key.offset = start - found_start; | |
761 | ||
762 | btrfs_release_path(path); | |
763 | ret = btrfs_insert_empty_item(trans, root, path, &key, 0); | |
764 | if (ret) | |
765 | goto out; | |
766 | new_extents++; | |
767 | } | |
768 | ||
769 | /* Add a key for leftovers at the end (cases 2 and 4). */ | |
770 | if (end < found_end) { | |
771 | key.objectid = end; | |
772 | key.type = BTRFS_FREE_SPACE_EXTENT_KEY; | |
773 | key.offset = found_end - end; | |
774 | ||
775 | btrfs_release_path(path); | |
776 | ret = btrfs_insert_empty_item(trans, root, path, &key, 0); | |
777 | if (ret) | |
778 | goto out; | |
779 | new_extents++; | |
780 | } | |
781 | ||
782 | btrfs_release_path(path); | |
783 | ret = update_free_space_extent_count(trans, fs_info, block_group, path, | |
784 | new_extents); | |
785 | ||
786 | out: | |
787 | return ret; | |
788 | } | |
789 | ||
790 | int __remove_from_free_space_tree(struct btrfs_trans_handle *trans, | |
791 | struct btrfs_fs_info *fs_info, | |
792 | struct btrfs_block_group_cache *block_group, | |
793 | struct btrfs_path *path, u64 start, u64 size) | |
794 | { | |
795 | struct btrfs_free_space_info *info; | |
796 | u32 flags; | |
797 | int ret; | |
798 | ||
799 | if (block_group->needs_free_space) { | |
800 | ret = __add_block_group_free_space(trans, fs_info, block_group, | |
801 | path); | |
802 | if (ret) | |
803 | return ret; | |
804 | } | |
805 | ||
806 | info = search_free_space_info(NULL, fs_info, block_group, path, 0); | |
807 | if (IS_ERR(info)) | |
808 | return PTR_ERR(info); | |
809 | flags = btrfs_free_space_flags(path->nodes[0], info); | |
810 | btrfs_release_path(path); | |
811 | ||
812 | if (flags & BTRFS_FREE_SPACE_USING_BITMAPS) { | |
813 | return modify_free_space_bitmap(trans, fs_info, block_group, | |
814 | path, start, size, 1); | |
815 | } else { | |
816 | return remove_free_space_extent(trans, fs_info, block_group, | |
817 | path, start, size); | |
818 | } | |
819 | } | |
820 | ||
821 | int remove_from_free_space_tree(struct btrfs_trans_handle *trans, | |
822 | struct btrfs_fs_info *fs_info, | |
823 | u64 start, u64 size) | |
824 | { | |
825 | struct btrfs_block_group_cache *block_group; | |
826 | struct btrfs_path *path; | |
827 | int ret; | |
828 | ||
829 | if (!btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) | |
830 | return 0; | |
831 | ||
832 | path = btrfs_alloc_path(); | |
833 | if (!path) { | |
834 | ret = -ENOMEM; | |
835 | goto out; | |
836 | } | |
837 | ||
838 | block_group = btrfs_lookup_block_group(fs_info, start); | |
839 | if (!block_group) { | |
840 | ASSERT(0); | |
841 | ret = -ENOENT; | |
842 | goto out; | |
843 | } | |
844 | ||
845 | mutex_lock(&block_group->free_space_lock); | |
846 | ret = __remove_from_free_space_tree(trans, fs_info, block_group, path, | |
847 | start, size); | |
848 | mutex_unlock(&block_group->free_space_lock); | |
849 | ||
850 | btrfs_put_block_group(block_group); | |
851 | out: | |
852 | btrfs_free_path(path); | |
853 | if (ret) | |
854 | btrfs_abort_transaction(trans, fs_info->free_space_root, ret); | |
855 | return ret; | |
856 | } | |
857 | ||
858 | static int add_free_space_extent(struct btrfs_trans_handle *trans, | |
859 | struct btrfs_fs_info *fs_info, | |
860 | struct btrfs_block_group_cache *block_group, | |
861 | struct btrfs_path *path, | |
862 | u64 start, u64 size) | |
863 | { | |
864 | struct btrfs_root *root = fs_info->free_space_root; | |
865 | struct btrfs_key key, new_key; | |
866 | u64 found_start, found_end; | |
867 | u64 end = start + size; | |
868 | int new_extents = 1; | |
869 | int ret; | |
870 | ||
871 | /* | |
872 | * We are adding a new extent of free space, but we need to merge | |
873 | * extents. There are four cases here: | |
874 | * | |
875 | * 1. The new extent does not have any immediate neighbors to merge | |
876 | * with: add the new key and increment the free space extent count. We | |
877 | * may need to convert the block group to bitmaps as a result. | |
878 | * 2. The new extent has an immediate neighbor before it: remove the | |
879 | * previous key and insert a new key combining both of them. There is no | |
880 | * net change in the number of extents. | |
881 | * 3. The new extent has an immediate neighbor after it: remove the next | |
882 | * key and insert a new key combining both of them. There is no net | |
883 | * change in the number of extents. | |
884 | * 4. The new extent has immediate neighbors on both sides: remove both | |
885 | * of the keys and insert a new key combining all of them. Where we used | |
886 | * to have two extents, we now have one, so decrement the extent count. | |
887 | */ | |
888 | ||
889 | new_key.objectid = start; | |
890 | new_key.type = BTRFS_FREE_SPACE_EXTENT_KEY; | |
891 | new_key.offset = size; | |
892 | ||
893 | /* Search for a neighbor on the left. */ | |
894 | if (start == block_group->key.objectid) | |
895 | goto right; | |
896 | key.objectid = start - 1; | |
897 | key.type = (u8)-1; | |
898 | key.offset = (u64)-1; | |
899 | ||
900 | ret = btrfs_search_prev_slot(trans, root, &key, path, -1, 1); | |
901 | if (ret) | |
902 | goto out; | |
903 | ||
904 | btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); | |
905 | ||
906 | if (key.type != BTRFS_FREE_SPACE_EXTENT_KEY) { | |
907 | ASSERT(key.type == BTRFS_FREE_SPACE_INFO_KEY); | |
908 | btrfs_release_path(path); | |
909 | goto right; | |
910 | } | |
911 | ||
912 | found_start = key.objectid; | |
913 | found_end = key.objectid + key.offset; | |
914 | ASSERT(found_start >= block_group->key.objectid && | |
915 | found_end > block_group->key.objectid); | |
916 | ASSERT(found_start < start && found_end <= start); | |
917 | ||
918 | /* | |
919 | * Delete the neighbor on the left and absorb it into the new key (cases | |
920 | * 2 and 4). | |
921 | */ | |
922 | if (found_end == start) { | |
923 | ret = btrfs_del_item(trans, root, path); | |
924 | if (ret) | |
925 | goto out; | |
926 | new_key.objectid = found_start; | |
927 | new_key.offset += key.offset; | |
928 | new_extents--; | |
929 | } | |
930 | btrfs_release_path(path); | |
931 | ||
932 | right: | |
933 | /* Search for a neighbor on the right. */ | |
934 | if (end == block_group->key.objectid + block_group->key.offset) | |
935 | goto insert; | |
936 | key.objectid = end; | |
937 | key.type = (u8)-1; | |
938 | key.offset = (u64)-1; | |
939 | ||
940 | ret = btrfs_search_prev_slot(trans, root, &key, path, -1, 1); | |
941 | if (ret) | |
942 | goto out; | |
943 | ||
944 | btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); | |
945 | ||
946 | if (key.type != BTRFS_FREE_SPACE_EXTENT_KEY) { | |
947 | ASSERT(key.type == BTRFS_FREE_SPACE_INFO_KEY); | |
948 | btrfs_release_path(path); | |
949 | goto insert; | |
950 | } | |
951 | ||
952 | found_start = key.objectid; | |
953 | found_end = key.objectid + key.offset; | |
954 | ASSERT(found_start >= block_group->key.objectid && | |
955 | found_end > block_group->key.objectid); | |
956 | ASSERT((found_start < start && found_end <= start) || | |
957 | (found_start >= end && found_end > end)); | |
958 | ||
959 | /* | |
960 | * Delete the neighbor on the right and absorb it into the new key | |
961 | * (cases 3 and 4). | |
962 | */ | |
963 | if (found_start == end) { | |
964 | ret = btrfs_del_item(trans, root, path); | |
965 | if (ret) | |
966 | goto out; | |
967 | new_key.offset += key.offset; | |
968 | new_extents--; | |
969 | } | |
970 | btrfs_release_path(path); | |
971 | ||
972 | insert: | |
973 | /* Insert the new key (cases 1-4). */ | |
974 | ret = btrfs_insert_empty_item(trans, root, path, &new_key, 0); | |
975 | if (ret) | |
976 | goto out; | |
977 | ||
978 | btrfs_release_path(path); | |
979 | ret = update_free_space_extent_count(trans, fs_info, block_group, path, | |
980 | new_extents); | |
981 | ||
982 | out: | |
983 | return ret; | |
984 | } | |
985 | ||
986 | int __add_to_free_space_tree(struct btrfs_trans_handle *trans, | |
987 | struct btrfs_fs_info *fs_info, | |
988 | struct btrfs_block_group_cache *block_group, | |
989 | struct btrfs_path *path, u64 start, u64 size) | |
990 | { | |
991 | struct btrfs_free_space_info *info; | |
992 | u32 flags; | |
993 | int ret; | |
994 | ||
995 | if (block_group->needs_free_space) { | |
996 | ret = __add_block_group_free_space(trans, fs_info, block_group, | |
997 | path); | |
998 | if (ret) | |
999 | return ret; | |
1000 | } | |
1001 | ||
1002 | info = search_free_space_info(NULL, fs_info, block_group, path, 0); | |
1003 | if (IS_ERR(info)) | |
1004 | return PTR_ERR(info); | |
1005 | flags = btrfs_free_space_flags(path->nodes[0], info); | |
1006 | btrfs_release_path(path); | |
1007 | ||
1008 | if (flags & BTRFS_FREE_SPACE_USING_BITMAPS) { | |
1009 | return modify_free_space_bitmap(trans, fs_info, block_group, | |
1010 | path, start, size, 0); | |
1011 | } else { | |
1012 | return add_free_space_extent(trans, fs_info, block_group, path, | |
1013 | start, size); | |
1014 | } | |
1015 | } | |
1016 | ||
1017 | int add_to_free_space_tree(struct btrfs_trans_handle *trans, | |
1018 | struct btrfs_fs_info *fs_info, | |
1019 | u64 start, u64 size) | |
1020 | { | |
1021 | struct btrfs_block_group_cache *block_group; | |
1022 | struct btrfs_path *path; | |
1023 | int ret; | |
1024 | ||
1025 | if (!btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) | |
1026 | return 0; | |
1027 | ||
1028 | path = btrfs_alloc_path(); | |
1029 | if (!path) { | |
1030 | ret = -ENOMEM; | |
1031 | goto out; | |
1032 | } | |
1033 | ||
1034 | block_group = btrfs_lookup_block_group(fs_info, start); | |
1035 | if (!block_group) { | |
1036 | ASSERT(0); | |
1037 | ret = -ENOENT; | |
1038 | goto out; | |
1039 | } | |
1040 | ||
1041 | mutex_lock(&block_group->free_space_lock); | |
1042 | ret = __add_to_free_space_tree(trans, fs_info, block_group, path, start, | |
1043 | size); | |
1044 | mutex_unlock(&block_group->free_space_lock); | |
1045 | ||
1046 | btrfs_put_block_group(block_group); | |
1047 | out: | |
1048 | btrfs_free_path(path); | |
1049 | if (ret) | |
1050 | btrfs_abort_transaction(trans, fs_info->free_space_root, ret); | |
1051 | return ret; | |
1052 | } | |
1053 | ||
1054 | /* | |
1055 | * Populate the free space tree by walking the extent tree. Operations on the | |
1056 | * extent tree that happen as a result of writes to the free space tree will go | |
1057 | * through the normal add/remove hooks. | |
1058 | */ | |
1059 | static int populate_free_space_tree(struct btrfs_trans_handle *trans, | |
1060 | struct btrfs_fs_info *fs_info, | |
1061 | struct btrfs_block_group_cache *block_group) | |
1062 | { | |
1063 | struct btrfs_root *extent_root = fs_info->extent_root; | |
1064 | struct btrfs_path *path, *path2; | |
1065 | struct btrfs_key key; | |
1066 | u64 start, end; | |
1067 | int ret; | |
1068 | ||
1069 | path = btrfs_alloc_path(); | |
1070 | if (!path) | |
1071 | return -ENOMEM; | |
1072 | path->reada = 1; | |
1073 | ||
1074 | path2 = btrfs_alloc_path(); | |
1075 | if (!path2) { | |
1076 | btrfs_free_path(path); | |
1077 | return -ENOMEM; | |
1078 | } | |
1079 | ||
1080 | ret = add_new_free_space_info(trans, fs_info, block_group, path2); | |
1081 | if (ret) | |
1082 | goto out; | |
1083 | ||
511711af CM |
1084 | mutex_lock(&block_group->free_space_lock); |
1085 | ||
a5ed9182 OS |
1086 | /* |
1087 | * Iterate through all of the extent and metadata items in this block | |
1088 | * group, adding the free space between them and the free space at the | |
1089 | * end. Note that EXTENT_ITEM and METADATA_ITEM are less than | |
1090 | * BLOCK_GROUP_ITEM, so an extent may precede the block group that it's | |
1091 | * contained in. | |
1092 | */ | |
1093 | key.objectid = block_group->key.objectid; | |
1094 | key.type = BTRFS_EXTENT_ITEM_KEY; | |
1095 | key.offset = 0; | |
1096 | ||
1097 | ret = btrfs_search_slot_for_read(extent_root, &key, path, 1, 0); | |
1098 | if (ret < 0) | |
511711af | 1099 | goto out_locked; |
a5ed9182 OS |
1100 | ASSERT(ret == 0); |
1101 | ||
1102 | start = block_group->key.objectid; | |
1103 | end = block_group->key.objectid + block_group->key.offset; | |
1104 | while (1) { | |
1105 | btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); | |
1106 | ||
1107 | if (key.type == BTRFS_EXTENT_ITEM_KEY || | |
1108 | key.type == BTRFS_METADATA_ITEM_KEY) { | |
1109 | if (key.objectid >= end) | |
1110 | break; | |
1111 | ||
1112 | if (start < key.objectid) { | |
1113 | ret = __add_to_free_space_tree(trans, fs_info, | |
1114 | block_group, | |
1115 | path2, start, | |
1116 | key.objectid - | |
1117 | start); | |
1118 | if (ret) | |
511711af | 1119 | goto out_locked; |
a5ed9182 OS |
1120 | } |
1121 | start = key.objectid; | |
1122 | if (key.type == BTRFS_METADATA_ITEM_KEY) | |
1123 | start += fs_info->tree_root->nodesize; | |
1124 | else | |
1125 | start += key.offset; | |
1126 | } else if (key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) { | |
1127 | if (key.objectid != block_group->key.objectid) | |
1128 | break; | |
1129 | } | |
1130 | ||
1131 | ret = btrfs_next_item(extent_root, path); | |
1132 | if (ret < 0) | |
511711af | 1133 | goto out_locked; |
a5ed9182 OS |
1134 | if (ret) |
1135 | break; | |
1136 | } | |
1137 | if (start < end) { | |
1138 | ret = __add_to_free_space_tree(trans, fs_info, block_group, | |
1139 | path2, start, end - start); | |
1140 | if (ret) | |
511711af | 1141 | goto out_locked; |
a5ed9182 OS |
1142 | } |
1143 | ||
1144 | ret = 0; | |
511711af CM |
1145 | out_locked: |
1146 | mutex_unlock(&block_group->free_space_lock); | |
a5ed9182 OS |
1147 | out: |
1148 | btrfs_free_path(path2); | |
1149 | btrfs_free_path(path); | |
1150 | return ret; | |
1151 | } | |
1152 | ||
1153 | int btrfs_create_free_space_tree(struct btrfs_fs_info *fs_info) | |
1154 | { | |
1155 | struct btrfs_trans_handle *trans; | |
1156 | struct btrfs_root *tree_root = fs_info->tree_root; | |
1157 | struct btrfs_root *free_space_root; | |
1158 | struct btrfs_block_group_cache *block_group; | |
1159 | struct rb_node *node; | |
1160 | int ret; | |
1161 | ||
1162 | trans = btrfs_start_transaction(tree_root, 0); | |
1163 | if (IS_ERR(trans)) | |
1164 | return PTR_ERR(trans); | |
1165 | ||
511711af | 1166 | fs_info->creating_free_space_tree = 1; |
a5ed9182 OS |
1167 | free_space_root = btrfs_create_tree(trans, fs_info, |
1168 | BTRFS_FREE_SPACE_TREE_OBJECTID); | |
1169 | if (IS_ERR(free_space_root)) { | |
1170 | ret = PTR_ERR(free_space_root); | |
1171 | goto abort; | |
1172 | } | |
1173 | fs_info->free_space_root = free_space_root; | |
1174 | ||
1175 | node = rb_first(&fs_info->block_group_cache_tree); | |
1176 | while (node) { | |
1177 | block_group = rb_entry(node, struct btrfs_block_group_cache, | |
1178 | cache_node); | |
1179 | ret = populate_free_space_tree(trans, fs_info, block_group); | |
1180 | if (ret) | |
1181 | goto abort; | |
1182 | node = rb_next(node); | |
1183 | } | |
1184 | ||
1185 | btrfs_set_fs_compat_ro(fs_info, FREE_SPACE_TREE); | |
511711af | 1186 | fs_info->creating_free_space_tree = 0; |
a5ed9182 OS |
1187 | |
1188 | ret = btrfs_commit_transaction(trans, tree_root); | |
1189 | if (ret) | |
1190 | return ret; | |
1191 | ||
1192 | return 0; | |
1193 | ||
1194 | abort: | |
511711af | 1195 | fs_info->creating_free_space_tree = 0; |
a5ed9182 OS |
1196 | btrfs_abort_transaction(trans, tree_root, ret); |
1197 | btrfs_end_transaction(trans, tree_root); | |
1198 | return ret; | |
1199 | } | |
1200 | ||
1201 | static int clear_free_space_tree(struct btrfs_trans_handle *trans, | |
1202 | struct btrfs_root *root) | |
1203 | { | |
1204 | struct btrfs_path *path; | |
1205 | struct btrfs_key key; | |
1206 | int nr; | |
1207 | int ret; | |
1208 | ||
1209 | path = btrfs_alloc_path(); | |
1210 | if (!path) | |
1211 | return -ENOMEM; | |
1212 | ||
1213 | path->leave_spinning = 1; | |
1214 | ||
1215 | key.objectid = 0; | |
1216 | key.type = 0; | |
1217 | key.offset = 0; | |
1218 | ||
1219 | while (1) { | |
1220 | ret = btrfs_search_slot(trans, root, &key, path, -1, 1); | |
1221 | if (ret < 0) | |
1222 | goto out; | |
1223 | ||
1224 | nr = btrfs_header_nritems(path->nodes[0]); | |
1225 | if (!nr) | |
1226 | break; | |
1227 | ||
1228 | path->slots[0] = 0; | |
1229 | ret = btrfs_del_items(trans, root, path, 0, nr); | |
1230 | if (ret) | |
1231 | goto out; | |
1232 | ||
1233 | btrfs_release_path(path); | |
1234 | } | |
1235 | ||
1236 | ret = 0; | |
1237 | out: | |
1238 | btrfs_free_path(path); | |
1239 | return ret; | |
1240 | } | |
1241 | ||
1242 | int btrfs_clear_free_space_tree(struct btrfs_fs_info *fs_info) | |
1243 | { | |
1244 | struct btrfs_trans_handle *trans; | |
1245 | struct btrfs_root *tree_root = fs_info->tree_root; | |
1246 | struct btrfs_root *free_space_root = fs_info->free_space_root; | |
1247 | int ret; | |
1248 | ||
1249 | trans = btrfs_start_transaction(tree_root, 0); | |
1250 | if (IS_ERR(trans)) | |
1251 | return PTR_ERR(trans); | |
1252 | ||
1253 | btrfs_clear_fs_compat_ro(fs_info, FREE_SPACE_TREE); | |
1254 | fs_info->free_space_root = NULL; | |
1255 | ||
1256 | ret = clear_free_space_tree(trans, free_space_root); | |
1257 | if (ret) | |
1258 | goto abort; | |
1259 | ||
1260 | ret = btrfs_del_root(trans, tree_root, &free_space_root->root_key); | |
1261 | if (ret) | |
1262 | goto abort; | |
1263 | ||
1264 | list_del(&free_space_root->dirty_list); | |
1265 | ||
1266 | btrfs_tree_lock(free_space_root->node); | |
1267 | clean_tree_block(trans, tree_root->fs_info, free_space_root->node); | |
1268 | btrfs_tree_unlock(free_space_root->node); | |
1269 | btrfs_free_tree_block(trans, free_space_root, free_space_root->node, | |
1270 | 0, 1); | |
1271 | ||
1272 | free_extent_buffer(free_space_root->node); | |
1273 | free_extent_buffer(free_space_root->commit_root); | |
1274 | kfree(free_space_root); | |
1275 | ||
1276 | ret = btrfs_commit_transaction(trans, tree_root); | |
1277 | if (ret) | |
1278 | return ret; | |
1279 | ||
1280 | return 0; | |
1281 | ||
1282 | abort: | |
1283 | btrfs_abort_transaction(trans, tree_root, ret); | |
1284 | btrfs_end_transaction(trans, tree_root); | |
1285 | return ret; | |
1286 | } | |
1287 | ||
1288 | static int __add_block_group_free_space(struct btrfs_trans_handle *trans, | |
1289 | struct btrfs_fs_info *fs_info, | |
1290 | struct btrfs_block_group_cache *block_group, | |
1291 | struct btrfs_path *path) | |
1292 | { | |
1293 | u64 start, end; | |
1294 | int ret; | |
1295 | ||
1296 | start = block_group->key.objectid; | |
1297 | end = block_group->key.objectid + block_group->key.offset; | |
1298 | ||
1299 | block_group->needs_free_space = 0; | |
1300 | ||
1301 | ret = add_new_free_space_info(trans, fs_info, block_group, path); | |
1302 | if (ret) | |
1303 | return ret; | |
1304 | ||
1305 | return __add_to_free_space_tree(trans, fs_info, block_group, path, | |
1306 | block_group->key.objectid, | |
1307 | block_group->key.offset); | |
1308 | } | |
1309 | ||
1310 | int add_block_group_free_space(struct btrfs_trans_handle *trans, | |
1311 | struct btrfs_fs_info *fs_info, | |
1312 | struct btrfs_block_group_cache *block_group) | |
1313 | { | |
1314 | struct btrfs_path *path = NULL; | |
1315 | int ret = 0; | |
1316 | ||
1317 | if (!btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) | |
1318 | return 0; | |
1319 | ||
1320 | mutex_lock(&block_group->free_space_lock); | |
1321 | if (!block_group->needs_free_space) | |
1322 | goto out; | |
1323 | ||
1324 | path = btrfs_alloc_path(); | |
1325 | if (!path) { | |
1326 | ret = -ENOMEM; | |
1327 | goto out; | |
1328 | } | |
1329 | ||
1330 | ret = __add_block_group_free_space(trans, fs_info, block_group, path); | |
1331 | ||
1332 | out: | |
1333 | btrfs_free_path(path); | |
1334 | mutex_unlock(&block_group->free_space_lock); | |
1335 | if (ret) | |
1336 | btrfs_abort_transaction(trans, fs_info->free_space_root, ret); | |
1337 | return ret; | |
1338 | } | |
1339 | ||
1340 | int remove_block_group_free_space(struct btrfs_trans_handle *trans, | |
1341 | struct btrfs_fs_info *fs_info, | |
1342 | struct btrfs_block_group_cache *block_group) | |
1343 | { | |
1344 | struct btrfs_root *root = fs_info->free_space_root; | |
1345 | struct btrfs_path *path; | |
1346 | struct btrfs_key key, found_key; | |
1347 | struct extent_buffer *leaf; | |
1348 | u64 start, end; | |
1349 | int done = 0, nr; | |
1350 | int ret; | |
1351 | ||
1352 | if (!btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) | |
1353 | return 0; | |
1354 | ||
1355 | if (block_group->needs_free_space) { | |
1356 | /* We never added this block group to the free space tree. */ | |
1357 | return 0; | |
1358 | } | |
1359 | ||
1360 | path = btrfs_alloc_path(); | |
1361 | if (!path) { | |
1362 | ret = -ENOMEM; | |
1363 | goto out; | |
1364 | } | |
1365 | ||
1366 | start = block_group->key.objectid; | |
1367 | end = block_group->key.objectid + block_group->key.offset; | |
1368 | ||
1369 | key.objectid = end - 1; | |
1370 | key.type = (u8)-1; | |
1371 | key.offset = (u64)-1; | |
1372 | ||
1373 | while (!done) { | |
1374 | ret = btrfs_search_prev_slot(trans, root, &key, path, -1, 1); | |
1375 | if (ret) | |
1376 | goto out; | |
1377 | ||
1378 | leaf = path->nodes[0]; | |
1379 | nr = 0; | |
1380 | path->slots[0]++; | |
1381 | while (path->slots[0] > 0) { | |
1382 | btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0] - 1); | |
1383 | ||
1384 | if (found_key.type == BTRFS_FREE_SPACE_INFO_KEY) { | |
1385 | ASSERT(found_key.objectid == block_group->key.objectid); | |
1386 | ASSERT(found_key.offset == block_group->key.offset); | |
1387 | done = 1; | |
1388 | nr++; | |
1389 | path->slots[0]--; | |
1390 | break; | |
1391 | } else if (found_key.type == BTRFS_FREE_SPACE_EXTENT_KEY || | |
1392 | found_key.type == BTRFS_FREE_SPACE_BITMAP_KEY) { | |
1393 | ASSERT(found_key.objectid >= start); | |
1394 | ASSERT(found_key.objectid < end); | |
1395 | ASSERT(found_key.objectid + found_key.offset <= end); | |
1396 | nr++; | |
1397 | path->slots[0]--; | |
1398 | } else { | |
1399 | ASSERT(0); | |
1400 | } | |
1401 | } | |
1402 | ||
1403 | ret = btrfs_del_items(trans, root, path, path->slots[0], nr); | |
1404 | if (ret) | |
1405 | goto out; | |
1406 | btrfs_release_path(path); | |
1407 | } | |
1408 | ||
1409 | ret = 0; | |
1410 | out: | |
1411 | btrfs_free_path(path); | |
1412 | if (ret) | |
1413 | btrfs_abort_transaction(trans, root, ret); | |
1414 | return ret; | |
1415 | } | |
1416 | ||
1417 | static int load_free_space_bitmaps(struct btrfs_caching_control *caching_ctl, | |
1418 | struct btrfs_path *path, | |
1419 | u32 expected_extent_count) | |
1420 | { | |
1421 | struct btrfs_block_group_cache *block_group; | |
1422 | struct btrfs_fs_info *fs_info; | |
1423 | struct btrfs_root *root; | |
1424 | struct btrfs_key key; | |
1425 | int prev_bit = 0, bit; | |
1426 | /* Initialize to silence GCC. */ | |
1427 | u64 extent_start = 0; | |
1428 | u64 end, offset; | |
1429 | u64 total_found = 0; | |
1430 | u32 extent_count = 0; | |
1431 | int ret; | |
1432 | ||
1433 | block_group = caching_ctl->block_group; | |
1434 | fs_info = block_group->fs_info; | |
1435 | root = fs_info->free_space_root; | |
1436 | ||
1437 | end = block_group->key.objectid + block_group->key.offset; | |
1438 | ||
1439 | while (1) { | |
1440 | ret = btrfs_next_item(root, path); | |
1441 | if (ret < 0) | |
1442 | goto out; | |
1443 | if (ret) | |
1444 | break; | |
1445 | ||
1446 | btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); | |
1447 | ||
1448 | if (key.type == BTRFS_FREE_SPACE_INFO_KEY) | |
1449 | break; | |
1450 | ||
1451 | ASSERT(key.type == BTRFS_FREE_SPACE_BITMAP_KEY); | |
1452 | ASSERT(key.objectid < end && key.objectid + key.offset <= end); | |
1453 | ||
1454 | caching_ctl->progress = key.objectid; | |
1455 | ||
1456 | offset = key.objectid; | |
1457 | while (offset < key.objectid + key.offset) { | |
1458 | bit = free_space_test_bit(block_group, path, offset); | |
1459 | if (prev_bit == 0 && bit == 1) { | |
1460 | extent_start = offset; | |
1461 | } else if (prev_bit == 1 && bit == 0) { | |
1462 | total_found += add_new_free_space(block_group, | |
1463 | fs_info, | |
1464 | extent_start, | |
1465 | offset); | |
1466 | if (total_found > CACHING_CTL_WAKE_UP) { | |
1467 | total_found = 0; | |
1468 | wake_up(&caching_ctl->wait); | |
1469 | } | |
1470 | extent_count++; | |
1471 | } | |
1472 | prev_bit = bit; | |
1473 | offset += block_group->sectorsize; | |
1474 | } | |
1475 | } | |
1476 | if (prev_bit == 1) { | |
1477 | total_found += add_new_free_space(block_group, fs_info, | |
1478 | extent_start, end); | |
1479 | extent_count++; | |
1480 | } | |
1481 | ||
1482 | if (extent_count != expected_extent_count) { | |
1483 | btrfs_err(fs_info, "incorrect extent count for %llu; counted %u, expected %u", | |
1484 | block_group->key.objectid, extent_count, | |
1485 | expected_extent_count); | |
1486 | ASSERT(0); | |
1487 | ret = -EIO; | |
1488 | goto out; | |
1489 | } | |
1490 | ||
1491 | caching_ctl->progress = (u64)-1; | |
1492 | ||
1493 | ret = 0; | |
1494 | out: | |
1495 | return ret; | |
1496 | } | |
1497 | ||
1498 | static int load_free_space_extents(struct btrfs_caching_control *caching_ctl, | |
1499 | struct btrfs_path *path, | |
1500 | u32 expected_extent_count) | |
1501 | { | |
1502 | struct btrfs_block_group_cache *block_group; | |
1503 | struct btrfs_fs_info *fs_info; | |
1504 | struct btrfs_root *root; | |
1505 | struct btrfs_key key; | |
1506 | u64 end; | |
1507 | u64 total_found = 0; | |
1508 | u32 extent_count = 0; | |
1509 | int ret; | |
1510 | ||
1511 | block_group = caching_ctl->block_group; | |
1512 | fs_info = block_group->fs_info; | |
1513 | root = fs_info->free_space_root; | |
1514 | ||
1515 | end = block_group->key.objectid + block_group->key.offset; | |
1516 | ||
1517 | while (1) { | |
1518 | ret = btrfs_next_item(root, path); | |
1519 | if (ret < 0) | |
1520 | goto out; | |
1521 | if (ret) | |
1522 | break; | |
1523 | ||
1524 | btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); | |
1525 | ||
1526 | if (key.type == BTRFS_FREE_SPACE_INFO_KEY) | |
1527 | break; | |
1528 | ||
1529 | ASSERT(key.type == BTRFS_FREE_SPACE_EXTENT_KEY); | |
1530 | ASSERT(key.objectid < end && key.objectid + key.offset <= end); | |
1531 | ||
1532 | caching_ctl->progress = key.objectid; | |
1533 | ||
1534 | total_found += add_new_free_space(block_group, fs_info, | |
1535 | key.objectid, | |
1536 | key.objectid + key.offset); | |
1537 | if (total_found > CACHING_CTL_WAKE_UP) { | |
1538 | total_found = 0; | |
1539 | wake_up(&caching_ctl->wait); | |
1540 | } | |
1541 | extent_count++; | |
1542 | } | |
1543 | ||
1544 | if (extent_count != expected_extent_count) { | |
1545 | btrfs_err(fs_info, "incorrect extent count for %llu; counted %u, expected %u", | |
1546 | block_group->key.objectid, extent_count, | |
1547 | expected_extent_count); | |
1548 | ASSERT(0); | |
1549 | ret = -EIO; | |
1550 | goto out; | |
1551 | } | |
1552 | ||
1553 | caching_ctl->progress = (u64)-1; | |
1554 | ||
1555 | ret = 0; | |
1556 | out: | |
1557 | return ret; | |
1558 | } | |
1559 | ||
1560 | int load_free_space_tree(struct btrfs_caching_control *caching_ctl) | |
1561 | { | |
1562 | struct btrfs_block_group_cache *block_group; | |
1563 | struct btrfs_fs_info *fs_info; | |
1564 | struct btrfs_free_space_info *info; | |
1565 | struct btrfs_path *path; | |
1566 | u32 extent_count, flags; | |
1567 | int ret; | |
1568 | ||
1569 | block_group = caching_ctl->block_group; | |
1570 | fs_info = block_group->fs_info; | |
1571 | ||
1572 | path = btrfs_alloc_path(); | |
1573 | if (!path) | |
1574 | return -ENOMEM; | |
1575 | ||
1576 | /* | |
1577 | * Just like caching_thread() doesn't want to deadlock on the extent | |
1578 | * tree, we don't want to deadlock on the free space tree. | |
1579 | */ | |
1580 | path->skip_locking = 1; | |
1581 | path->search_commit_root = 1; | |
1582 | path->reada = 1; | |
1583 | ||
1584 | info = search_free_space_info(NULL, fs_info, block_group, path, 0); | |
1585 | if (IS_ERR(info)) { | |
1586 | ret = PTR_ERR(info); | |
1587 | goto out; | |
1588 | } | |
1589 | extent_count = btrfs_free_space_extent_count(path->nodes[0], info); | |
1590 | flags = btrfs_free_space_flags(path->nodes[0], info); | |
1591 | ||
1592 | /* | |
1593 | * We left path pointing to the free space info item, so now | |
1594 | * load_free_space_foo can just iterate through the free space tree from | |
1595 | * there. | |
1596 | */ | |
1597 | if (flags & BTRFS_FREE_SPACE_USING_BITMAPS) | |
1598 | ret = load_free_space_bitmaps(caching_ctl, path, extent_count); | |
1599 | else | |
1600 | ret = load_free_space_extents(caching_ctl, path, extent_count); | |
1601 | ||
1602 | out: | |
1603 | btrfs_free_path(path); | |
1604 | return ret; | |
1605 | } |