blob: 8fd85bfbe2dab7dd4904f4d7421e450f912d5df7 [file] [log] [blame]
Omar Sandovala5ed9182015-09-29 20:50:35 -07001/*
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
27static 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
32void 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
60static 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;
87out:
88 btrfs_release_path(path);
89 return ret;
90}
91
92struct btrfs_free_space_info *
93search_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 */
124static 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
149static 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
Omar Sandoval2fe1d552016-09-22 17:24:20 -0700154static u8 *alloc_bitmap(u32 bitmap_size)
Omar Sandovala5ed9182015-09-29 20:50:35 -0700155{
David Sterba79b134a2016-01-22 17:16:18 +0100156 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
Chris Masone1c0eba2016-01-27 06:38:45 -0800166 mem = kzalloc(bitmap_size, GFP_NOFS | __GFP_NOWARN);
David Sterba79b134a2016-01-22 17:16:18 +0100167 if (mem)
168 return mem;
169
Omar Sandovala5ed9182015-09-29 20:50:35 -0700170 return __vmalloc(bitmap_size, GFP_NOFS | __GFP_HIGHMEM | __GFP_ZERO,
171 PAGE_KERNEL);
172}
173
174int 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;
Omar Sandoval2fe1d552016-09-22 17:24:20 -0700183 u8 *bitmap, *bitmap_cursor;
Omar Sandovala5ed9182015-09-29 20:50:35 -0700184 u64 start, end;
185 u64 bitmap_range, i;
186 u32 bitmap_size, flags, expected_extent_count;
187 u32 extent_count = 0;
188 int done = 0, nr;
189 int ret;
190
191 bitmap_size = free_space_bitmap_size(block_group->key.offset,
192 block_group->sectorsize);
193 bitmap = alloc_bitmap(bitmap_size);
194 if (!bitmap) {
195 ret = -ENOMEM;
196 goto out;
197 }
198
199 start = block_group->key.objectid;
200 end = block_group->key.objectid + block_group->key.offset;
201
202 key.objectid = end - 1;
203 key.type = (u8)-1;
204 key.offset = (u64)-1;
205
206 while (!done) {
207 ret = btrfs_search_prev_slot(trans, root, &key, path, -1, 1);
208 if (ret)
209 goto out;
210
211 leaf = path->nodes[0];
212 nr = 0;
213 path->slots[0]++;
214 while (path->slots[0] > 0) {
215 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0] - 1);
216
217 if (found_key.type == BTRFS_FREE_SPACE_INFO_KEY) {
218 ASSERT(found_key.objectid == block_group->key.objectid);
219 ASSERT(found_key.offset == block_group->key.offset);
220 done = 1;
221 break;
222 } else if (found_key.type == BTRFS_FREE_SPACE_EXTENT_KEY) {
223 u64 first, last;
224
225 ASSERT(found_key.objectid >= start);
226 ASSERT(found_key.objectid < end);
227 ASSERT(found_key.objectid + found_key.offset <= end);
228
229 first = div_u64(found_key.objectid - start,
230 block_group->sectorsize);
231 last = div_u64(found_key.objectid + found_key.offset - start,
232 block_group->sectorsize);
Omar Sandoval2fe1d552016-09-22 17:24:20 -0700233 le_bitmap_set(bitmap, first, last - first);
Omar Sandovala5ed9182015-09-29 20:50:35 -0700234
235 extent_count++;
236 nr++;
237 path->slots[0]--;
238 } else {
239 ASSERT(0);
240 }
241 }
242
243 ret = btrfs_del_items(trans, root, path, path->slots[0], nr);
244 if (ret)
245 goto out;
246 btrfs_release_path(path);
247 }
248
249 info = search_free_space_info(trans, fs_info, block_group, path, 1);
250 if (IS_ERR(info)) {
251 ret = PTR_ERR(info);
252 goto out;
253 }
254 leaf = path->nodes[0];
255 flags = btrfs_free_space_flags(leaf, info);
256 flags |= BTRFS_FREE_SPACE_USING_BITMAPS;
257 btrfs_set_free_space_flags(leaf, info, flags);
258 expected_extent_count = btrfs_free_space_extent_count(leaf, info);
259 btrfs_mark_buffer_dirty(leaf);
260 btrfs_release_path(path);
261
262 if (extent_count != expected_extent_count) {
263 btrfs_err(fs_info, "incorrect extent count for %llu; counted %u, expected %u",
264 block_group->key.objectid, extent_count,
265 expected_extent_count);
266 ASSERT(0);
267 ret = -EIO;
268 goto out;
269 }
270
Omar Sandoval2fe1d552016-09-22 17:24:20 -0700271 bitmap_cursor = bitmap;
Omar Sandovala5ed9182015-09-29 20:50:35 -0700272 bitmap_range = block_group->sectorsize * BTRFS_FREE_SPACE_BITMAP_BITS;
273 i = start;
274 while (i < end) {
275 unsigned long ptr;
276 u64 extent_size;
277 u32 data_size;
278
279 extent_size = min(end - i, bitmap_range);
280 data_size = free_space_bitmap_size(extent_size,
281 block_group->sectorsize);
282
283 key.objectid = i;
284 key.type = BTRFS_FREE_SPACE_BITMAP_KEY;
285 key.offset = extent_size;
286
287 ret = btrfs_insert_empty_item(trans, root, path, &key,
288 data_size);
289 if (ret)
290 goto out;
291
292 leaf = path->nodes[0];
293 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
294 write_extent_buffer(leaf, bitmap_cursor, ptr,
295 data_size);
296 btrfs_mark_buffer_dirty(leaf);
297 btrfs_release_path(path);
298
299 i += extent_size;
300 bitmap_cursor += data_size;
301 }
302
303 ret = 0;
304out:
David Sterba79b134a2016-01-22 17:16:18 +0100305 kvfree(bitmap);
Omar Sandovala5ed9182015-09-29 20:50:35 -0700306 if (ret)
Jeff Mahoney66642832016-06-10 18:19:25 -0400307 btrfs_abort_transaction(trans, ret);
Omar Sandovala5ed9182015-09-29 20:50:35 -0700308 return ret;
309}
310
311int convert_free_space_to_extents(struct btrfs_trans_handle *trans,
312 struct btrfs_fs_info *fs_info,
313 struct btrfs_block_group_cache *block_group,
314 struct btrfs_path *path)
315{
316 struct btrfs_root *root = fs_info->free_space_root;
317 struct btrfs_free_space_info *info;
318 struct btrfs_key key, found_key;
319 struct extent_buffer *leaf;
Omar Sandoval2fe1d552016-09-22 17:24:20 -0700320 u8 *bitmap;
Omar Sandovala5ed9182015-09-29 20:50:35 -0700321 u64 start, end;
322 /* Initialize to silence GCC. */
323 u64 extent_start = 0;
324 u64 offset;
325 u32 bitmap_size, flags, expected_extent_count;
326 int prev_bit = 0, bit, bitnr;
327 u32 extent_count = 0;
328 int done = 0, nr;
329 int ret;
330
331 bitmap_size = free_space_bitmap_size(block_group->key.offset,
332 block_group->sectorsize);
333 bitmap = alloc_bitmap(bitmap_size);
334 if (!bitmap) {
335 ret = -ENOMEM;
336 goto out;
337 }
338
339 start = block_group->key.objectid;
340 end = block_group->key.objectid + block_group->key.offset;
341
342 key.objectid = end - 1;
343 key.type = (u8)-1;
344 key.offset = (u64)-1;
345
346 while (!done) {
347 ret = btrfs_search_prev_slot(trans, root, &key, path, -1, 1);
348 if (ret)
349 goto out;
350
351 leaf = path->nodes[0];
352 nr = 0;
353 path->slots[0]++;
354 while (path->slots[0] > 0) {
355 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0] - 1);
356
357 if (found_key.type == BTRFS_FREE_SPACE_INFO_KEY) {
358 ASSERT(found_key.objectid == block_group->key.objectid);
359 ASSERT(found_key.offset == block_group->key.offset);
360 done = 1;
361 break;
362 } else if (found_key.type == BTRFS_FREE_SPACE_BITMAP_KEY) {
363 unsigned long ptr;
Omar Sandoval2fe1d552016-09-22 17:24:20 -0700364 u8 *bitmap_cursor;
Omar Sandovala5ed9182015-09-29 20:50:35 -0700365 u32 bitmap_pos, data_size;
366
367 ASSERT(found_key.objectid >= start);
368 ASSERT(found_key.objectid < end);
369 ASSERT(found_key.objectid + found_key.offset <= end);
370
371 bitmap_pos = div_u64(found_key.objectid - start,
372 block_group->sectorsize *
373 BITS_PER_BYTE);
Omar Sandoval2fe1d552016-09-22 17:24:20 -0700374 bitmap_cursor = bitmap + bitmap_pos;
Omar Sandovala5ed9182015-09-29 20:50:35 -0700375 data_size = free_space_bitmap_size(found_key.offset,
376 block_group->sectorsize);
377
378 ptr = btrfs_item_ptr_offset(leaf, path->slots[0] - 1);
379 read_extent_buffer(leaf, bitmap_cursor, ptr,
380 data_size);
381
382 nr++;
383 path->slots[0]--;
384 } else {
385 ASSERT(0);
386 }
387 }
388
389 ret = btrfs_del_items(trans, root, path, path->slots[0], nr);
390 if (ret)
391 goto out;
392 btrfs_release_path(path);
393 }
394
395 info = search_free_space_info(trans, fs_info, block_group, path, 1);
396 if (IS_ERR(info)) {
397 ret = PTR_ERR(info);
398 goto out;
399 }
400 leaf = path->nodes[0];
401 flags = btrfs_free_space_flags(leaf, info);
402 flags &= ~BTRFS_FREE_SPACE_USING_BITMAPS;
403 btrfs_set_free_space_flags(leaf, info, flags);
404 expected_extent_count = btrfs_free_space_extent_count(leaf, info);
405 btrfs_mark_buffer_dirty(leaf);
406 btrfs_release_path(path);
407
408 offset = start;
409 bitnr = 0;
410 while (offset < end) {
Omar Sandoval2fe1d552016-09-22 17:24:20 -0700411 bit = !!le_test_bit(bitnr, bitmap);
Omar Sandovala5ed9182015-09-29 20:50:35 -0700412 if (prev_bit == 0 && bit == 1) {
413 extent_start = offset;
414 } else if (prev_bit == 1 && bit == 0) {
415 key.objectid = extent_start;
416 key.type = BTRFS_FREE_SPACE_EXTENT_KEY;
417 key.offset = offset - extent_start;
418
419 ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
420 if (ret)
421 goto out;
422 btrfs_release_path(path);
423
424 extent_count++;
425 }
426 prev_bit = bit;
427 offset += block_group->sectorsize;
428 bitnr++;
429 }
430 if (prev_bit == 1) {
431 key.objectid = extent_start;
432 key.type = BTRFS_FREE_SPACE_EXTENT_KEY;
433 key.offset = end - extent_start;
434
435 ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
436 if (ret)
437 goto out;
438 btrfs_release_path(path);
439
440 extent_count++;
441 }
442
443 if (extent_count != expected_extent_count) {
444 btrfs_err(fs_info, "incorrect extent count for %llu; counted %u, expected %u",
445 block_group->key.objectid, extent_count,
446 expected_extent_count);
447 ASSERT(0);
448 ret = -EIO;
449 goto out;
450 }
451
452 ret = 0;
453out:
David Sterba79b134a2016-01-22 17:16:18 +0100454 kvfree(bitmap);
Omar Sandovala5ed9182015-09-29 20:50:35 -0700455 if (ret)
Jeff Mahoney66642832016-06-10 18:19:25 -0400456 btrfs_abort_transaction(trans, ret);
Omar Sandovala5ed9182015-09-29 20:50:35 -0700457 return ret;
458}
459
460static int update_free_space_extent_count(struct btrfs_trans_handle *trans,
461 struct btrfs_fs_info *fs_info,
462 struct btrfs_block_group_cache *block_group,
463 struct btrfs_path *path,
464 int new_extents)
465{
466 struct btrfs_free_space_info *info;
467 u32 flags;
468 u32 extent_count;
469 int ret = 0;
470
471 if (new_extents == 0)
472 return 0;
473
474 info = search_free_space_info(trans, fs_info, block_group, path, 1);
475 if (IS_ERR(info)) {
476 ret = PTR_ERR(info);
477 goto out;
478 }
479 flags = btrfs_free_space_flags(path->nodes[0], info);
480 extent_count = btrfs_free_space_extent_count(path->nodes[0], info);
481
482 extent_count += new_extents;
483 btrfs_set_free_space_extent_count(path->nodes[0], info, extent_count);
484 btrfs_mark_buffer_dirty(path->nodes[0]);
485 btrfs_release_path(path);
486
487 if (!(flags & BTRFS_FREE_SPACE_USING_BITMAPS) &&
488 extent_count > block_group->bitmap_high_thresh) {
489 ret = convert_free_space_to_bitmaps(trans, fs_info, block_group,
490 path);
491 } else if ((flags & BTRFS_FREE_SPACE_USING_BITMAPS) &&
492 extent_count < block_group->bitmap_low_thresh) {
493 ret = convert_free_space_to_extents(trans, fs_info, block_group,
494 path);
495 }
496
497out:
498 return ret;
499}
500
501int free_space_test_bit(struct btrfs_block_group_cache *block_group,
502 struct btrfs_path *path, u64 offset)
503{
504 struct extent_buffer *leaf;
505 struct btrfs_key key;
506 u64 found_start, found_end;
507 unsigned long ptr, i;
508
509 leaf = path->nodes[0];
510 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
511 ASSERT(key.type == BTRFS_FREE_SPACE_BITMAP_KEY);
512
513 found_start = key.objectid;
514 found_end = key.objectid + key.offset;
515 ASSERT(offset >= found_start && offset < found_end);
516
517 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
518 i = div_u64(offset - found_start, block_group->sectorsize);
519 return !!extent_buffer_test_bit(leaf, ptr, i);
520}
521
522static void free_space_set_bits(struct btrfs_block_group_cache *block_group,
523 struct btrfs_path *path, u64 *start, u64 *size,
524 int bit)
525{
526 struct extent_buffer *leaf;
527 struct btrfs_key key;
528 u64 end = *start + *size;
529 u64 found_start, found_end;
530 unsigned long ptr, first, last;
531
532 leaf = path->nodes[0];
533 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
534 ASSERT(key.type == BTRFS_FREE_SPACE_BITMAP_KEY);
535
536 found_start = key.objectid;
537 found_end = key.objectid + key.offset;
538 ASSERT(*start >= found_start && *start < found_end);
539 ASSERT(end > found_start);
540
541 if (end > found_end)
542 end = found_end;
543
544 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
545 first = div_u64(*start - found_start, block_group->sectorsize);
546 last = div_u64(end - found_start, block_group->sectorsize);
547 if (bit)
548 extent_buffer_bitmap_set(leaf, ptr, first, last - first);
549 else
550 extent_buffer_bitmap_clear(leaf, ptr, first, last - first);
551 btrfs_mark_buffer_dirty(leaf);
552
553 *size -= end - *start;
554 *start = end;
555}
556
557/*
558 * We can't use btrfs_next_item() in modify_free_space_bitmap() because
559 * btrfs_next_leaf() doesn't get the path for writing. We can forgo the fancy
560 * tree walking in btrfs_next_leaf() anyways because we know exactly what we're
561 * looking for.
562 */
563static int free_space_next_bitmap(struct btrfs_trans_handle *trans,
564 struct btrfs_root *root, struct btrfs_path *p)
565{
566 struct btrfs_key key;
567
568 if (p->slots[0] + 1 < btrfs_header_nritems(p->nodes[0])) {
569 p->slots[0]++;
570 return 0;
571 }
572
573 btrfs_item_key_to_cpu(p->nodes[0], &key, p->slots[0]);
574 btrfs_release_path(p);
575
576 key.objectid += key.offset;
577 key.type = (u8)-1;
578 key.offset = (u64)-1;
579
580 return btrfs_search_prev_slot(trans, root, &key, p, 0, 1);
581}
582
583/*
584 * If remove is 1, then we are removing free space, thus clearing bits in the
585 * bitmap. If remove is 0, then we are adding free space, thus setting bits in
586 * the bitmap.
587 */
588static int modify_free_space_bitmap(struct btrfs_trans_handle *trans,
589 struct btrfs_fs_info *fs_info,
590 struct btrfs_block_group_cache *block_group,
591 struct btrfs_path *path,
592 u64 start, u64 size, int remove)
593{
594 struct btrfs_root *root = fs_info->free_space_root;
595 struct btrfs_key key;
596 u64 end = start + size;
597 u64 cur_start, cur_size;
598 int prev_bit, next_bit;
599 int new_extents;
600 int ret;
601
602 /*
603 * Read the bit for the block immediately before the extent of space if
604 * that block is within the block group.
605 */
606 if (start > block_group->key.objectid) {
607 u64 prev_block = start - block_group->sectorsize;
608
609 key.objectid = prev_block;
610 key.type = (u8)-1;
611 key.offset = (u64)-1;
612
613 ret = btrfs_search_prev_slot(trans, root, &key, path, 0, 1);
614 if (ret)
615 goto out;
616
617 prev_bit = free_space_test_bit(block_group, path, prev_block);
618
619 /* The previous block may have been in the previous bitmap. */
620 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
621 if (start >= key.objectid + key.offset) {
622 ret = free_space_next_bitmap(trans, root, path);
623 if (ret)
624 goto out;
625 }
626 } else {
627 key.objectid = start;
628 key.type = (u8)-1;
629 key.offset = (u64)-1;
630
631 ret = btrfs_search_prev_slot(trans, root, &key, path, 0, 1);
632 if (ret)
633 goto out;
634
635 prev_bit = -1;
636 }
637
638 /*
639 * Iterate over all of the bitmaps overlapped by the extent of space,
640 * clearing/setting bits as required.
641 */
642 cur_start = start;
643 cur_size = size;
644 while (1) {
645 free_space_set_bits(block_group, path, &cur_start, &cur_size,
646 !remove);
647 if (cur_size == 0)
648 break;
649 ret = free_space_next_bitmap(trans, root, path);
650 if (ret)
651 goto out;
652 }
653
654 /*
655 * Read the bit for the block immediately after the extent of space if
656 * that block is within the block group.
657 */
658 if (end < block_group->key.objectid + block_group->key.offset) {
659 /* The next block may be in the next bitmap. */
660 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
661 if (end >= key.objectid + key.offset) {
662 ret = free_space_next_bitmap(trans, root, path);
663 if (ret)
664 goto out;
665 }
666
667 next_bit = free_space_test_bit(block_group, path, end);
668 } else {
669 next_bit = -1;
670 }
671
672 if (remove) {
673 new_extents = -1;
674 if (prev_bit == 1) {
675 /* Leftover on the left. */
676 new_extents++;
677 }
678 if (next_bit == 1) {
679 /* Leftover on the right. */
680 new_extents++;
681 }
682 } else {
683 new_extents = 1;
684 if (prev_bit == 1) {
685 /* Merging with neighbor on the left. */
686 new_extents--;
687 }
688 if (next_bit == 1) {
689 /* Merging with neighbor on the right. */
690 new_extents--;
691 }
692 }
693
694 btrfs_release_path(path);
695 ret = update_free_space_extent_count(trans, fs_info, block_group, path,
696 new_extents);
697
698out:
699 return ret;
700}
701
702static int remove_free_space_extent(struct btrfs_trans_handle *trans,
703 struct btrfs_fs_info *fs_info,
704 struct btrfs_block_group_cache *block_group,
705 struct btrfs_path *path,
706 u64 start, u64 size)
707{
708 struct btrfs_root *root = fs_info->free_space_root;
709 struct btrfs_key key;
710 u64 found_start, found_end;
711 u64 end = start + size;
712 int new_extents = -1;
713 int ret;
714
715 key.objectid = start;
716 key.type = (u8)-1;
717 key.offset = (u64)-1;
718
719 ret = btrfs_search_prev_slot(trans, root, &key, path, -1, 1);
720 if (ret)
721 goto out;
722
723 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
724
725 ASSERT(key.type == BTRFS_FREE_SPACE_EXTENT_KEY);
726
727 found_start = key.objectid;
728 found_end = key.objectid + key.offset;
729 ASSERT(start >= found_start && end <= found_end);
730
731 /*
732 * Okay, now that we've found the free space extent which contains the
733 * free space that we are removing, there are four cases:
734 *
735 * 1. We're using the whole extent: delete the key we found and
736 * decrement the free space extent count.
737 * 2. We are using part of the extent starting at the beginning: delete
738 * the key we found and insert a new key representing the leftover at
739 * the end. There is no net change in the number of extents.
740 * 3. We are using part of the extent ending at the end: delete the key
741 * we found and insert a new key representing the leftover at the
742 * beginning. There is no net change in the number of extents.
743 * 4. We are using part of the extent in the middle: delete the key we
744 * found and insert two new keys representing the leftovers on each
745 * side. Where we used to have one extent, we now have two, so increment
746 * the extent count. We may need to convert the block group to bitmaps
747 * as a result.
748 */
749
750 /* Delete the existing key (cases 1-4). */
751 ret = btrfs_del_item(trans, root, path);
752 if (ret)
753 goto out;
754
755 /* Add a key for leftovers at the beginning (cases 3 and 4). */
756 if (start > found_start) {
757 key.objectid = found_start;
758 key.type = BTRFS_FREE_SPACE_EXTENT_KEY;
759 key.offset = start - found_start;
760
761 btrfs_release_path(path);
762 ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
763 if (ret)
764 goto out;
765 new_extents++;
766 }
767
768 /* Add a key for leftovers at the end (cases 2 and 4). */
769 if (end < found_end) {
770 key.objectid = end;
771 key.type = BTRFS_FREE_SPACE_EXTENT_KEY;
772 key.offset = found_end - end;
773
774 btrfs_release_path(path);
775 ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
776 if (ret)
777 goto out;
778 new_extents++;
779 }
780
781 btrfs_release_path(path);
782 ret = update_free_space_extent_count(trans, fs_info, block_group, path,
783 new_extents);
784
785out:
786 return ret;
787}
788
789int __remove_from_free_space_tree(struct btrfs_trans_handle *trans,
790 struct btrfs_fs_info *fs_info,
791 struct btrfs_block_group_cache *block_group,
792 struct btrfs_path *path, u64 start, u64 size)
793{
794 struct btrfs_free_space_info *info;
795 u32 flags;
796 int ret;
797
798 if (block_group->needs_free_space) {
799 ret = __add_block_group_free_space(trans, fs_info, block_group,
800 path);
801 if (ret)
802 return ret;
803 }
804
805 info = search_free_space_info(NULL, fs_info, block_group, path, 0);
806 if (IS_ERR(info))
807 return PTR_ERR(info);
808 flags = btrfs_free_space_flags(path->nodes[0], info);
809 btrfs_release_path(path);
810
811 if (flags & BTRFS_FREE_SPACE_USING_BITMAPS) {
812 return modify_free_space_bitmap(trans, fs_info, block_group,
813 path, start, size, 1);
814 } else {
815 return remove_free_space_extent(trans, fs_info, block_group,
816 path, start, size);
817 }
818}
819
820int remove_from_free_space_tree(struct btrfs_trans_handle *trans,
821 struct btrfs_fs_info *fs_info,
822 u64 start, u64 size)
823{
824 struct btrfs_block_group_cache *block_group;
825 struct btrfs_path *path;
826 int ret;
827
828 if (!btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE))
829 return 0;
830
831 path = btrfs_alloc_path();
832 if (!path) {
833 ret = -ENOMEM;
834 goto out;
835 }
836
837 block_group = btrfs_lookup_block_group(fs_info, start);
838 if (!block_group) {
839 ASSERT(0);
840 ret = -ENOENT;
841 goto out;
842 }
843
844 mutex_lock(&block_group->free_space_lock);
845 ret = __remove_from_free_space_tree(trans, fs_info, block_group, path,
846 start, size);
847 mutex_unlock(&block_group->free_space_lock);
848
849 btrfs_put_block_group(block_group);
850out:
851 btrfs_free_path(path);
852 if (ret)
Jeff Mahoney66642832016-06-10 18:19:25 -0400853 btrfs_abort_transaction(trans, ret);
Omar Sandovala5ed9182015-09-29 20:50:35 -0700854 return ret;
855}
856
857static int add_free_space_extent(struct btrfs_trans_handle *trans,
858 struct btrfs_fs_info *fs_info,
859 struct btrfs_block_group_cache *block_group,
860 struct btrfs_path *path,
861 u64 start, u64 size)
862{
863 struct btrfs_root *root = fs_info->free_space_root;
864 struct btrfs_key key, new_key;
865 u64 found_start, found_end;
866 u64 end = start + size;
867 int new_extents = 1;
868 int ret;
869
870 /*
871 * We are adding a new extent of free space, but we need to merge
872 * extents. There are four cases here:
873 *
874 * 1. The new extent does not have any immediate neighbors to merge
875 * with: add the new key and increment the free space extent count. We
876 * may need to convert the block group to bitmaps as a result.
877 * 2. The new extent has an immediate neighbor before it: remove the
878 * previous key and insert a new key combining both of them. There is no
879 * net change in the number of extents.
880 * 3. The new extent has an immediate neighbor after it: remove the next
881 * key and insert a new key combining both of them. There is no net
882 * change in the number of extents.
883 * 4. The new extent has immediate neighbors on both sides: remove both
884 * of the keys and insert a new key combining all of them. Where we used
885 * to have two extents, we now have one, so decrement the extent count.
886 */
887
888 new_key.objectid = start;
889 new_key.type = BTRFS_FREE_SPACE_EXTENT_KEY;
890 new_key.offset = size;
891
892 /* Search for a neighbor on the left. */
893 if (start == block_group->key.objectid)
894 goto right;
895 key.objectid = start - 1;
896 key.type = (u8)-1;
897 key.offset = (u64)-1;
898
899 ret = btrfs_search_prev_slot(trans, root, &key, path, -1, 1);
900 if (ret)
901 goto out;
902
903 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
904
905 if (key.type != BTRFS_FREE_SPACE_EXTENT_KEY) {
906 ASSERT(key.type == BTRFS_FREE_SPACE_INFO_KEY);
907 btrfs_release_path(path);
908 goto right;
909 }
910
911 found_start = key.objectid;
912 found_end = key.objectid + key.offset;
913 ASSERT(found_start >= block_group->key.objectid &&
914 found_end > block_group->key.objectid);
915 ASSERT(found_start < start && found_end <= start);
916
917 /*
918 * Delete the neighbor on the left and absorb it into the new key (cases
919 * 2 and 4).
920 */
921 if (found_end == start) {
922 ret = btrfs_del_item(trans, root, path);
923 if (ret)
924 goto out;
925 new_key.objectid = found_start;
926 new_key.offset += key.offset;
927 new_extents--;
928 }
929 btrfs_release_path(path);
930
931right:
932 /* Search for a neighbor on the right. */
933 if (end == block_group->key.objectid + block_group->key.offset)
934 goto insert;
935 key.objectid = end;
936 key.type = (u8)-1;
937 key.offset = (u64)-1;
938
939 ret = btrfs_search_prev_slot(trans, root, &key, path, -1, 1);
940 if (ret)
941 goto out;
942
943 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
944
945 if (key.type != BTRFS_FREE_SPACE_EXTENT_KEY) {
946 ASSERT(key.type == BTRFS_FREE_SPACE_INFO_KEY);
947 btrfs_release_path(path);
948 goto insert;
949 }
950
951 found_start = key.objectid;
952 found_end = key.objectid + key.offset;
953 ASSERT(found_start >= block_group->key.objectid &&
954 found_end > block_group->key.objectid);
955 ASSERT((found_start < start && found_end <= start) ||
956 (found_start >= end && found_end > end));
957
958 /*
959 * Delete the neighbor on the right and absorb it into the new key
960 * (cases 3 and 4).
961 */
962 if (found_start == end) {
963 ret = btrfs_del_item(trans, root, path);
964 if (ret)
965 goto out;
966 new_key.offset += key.offset;
967 new_extents--;
968 }
969 btrfs_release_path(path);
970
971insert:
972 /* Insert the new key (cases 1-4). */
973 ret = btrfs_insert_empty_item(trans, root, path, &new_key, 0);
974 if (ret)
975 goto out;
976
977 btrfs_release_path(path);
978 ret = update_free_space_extent_count(trans, fs_info, block_group, path,
979 new_extents);
980
981out:
982 return ret;
983}
984
985int __add_to_free_space_tree(struct btrfs_trans_handle *trans,
986 struct btrfs_fs_info *fs_info,
987 struct btrfs_block_group_cache *block_group,
988 struct btrfs_path *path, u64 start, u64 size)
989{
990 struct btrfs_free_space_info *info;
991 u32 flags;
992 int ret;
993
994 if (block_group->needs_free_space) {
995 ret = __add_block_group_free_space(trans, fs_info, block_group,
996 path);
997 if (ret)
998 return ret;
999 }
1000
1001 info = search_free_space_info(NULL, fs_info, block_group, path, 0);
1002 if (IS_ERR(info))
1003 return PTR_ERR(info);
1004 flags = btrfs_free_space_flags(path->nodes[0], info);
1005 btrfs_release_path(path);
1006
1007 if (flags & BTRFS_FREE_SPACE_USING_BITMAPS) {
1008 return modify_free_space_bitmap(trans, fs_info, block_group,
1009 path, start, size, 0);
1010 } else {
1011 return add_free_space_extent(trans, fs_info, block_group, path,
1012 start, size);
1013 }
1014}
1015
1016int add_to_free_space_tree(struct btrfs_trans_handle *trans,
1017 struct btrfs_fs_info *fs_info,
1018 u64 start, u64 size)
1019{
1020 struct btrfs_block_group_cache *block_group;
1021 struct btrfs_path *path;
1022 int ret;
1023
1024 if (!btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE))
1025 return 0;
1026
1027 path = btrfs_alloc_path();
1028 if (!path) {
1029 ret = -ENOMEM;
1030 goto out;
1031 }
1032
1033 block_group = btrfs_lookup_block_group(fs_info, start);
1034 if (!block_group) {
1035 ASSERT(0);
1036 ret = -ENOENT;
1037 goto out;
1038 }
1039
1040 mutex_lock(&block_group->free_space_lock);
1041 ret = __add_to_free_space_tree(trans, fs_info, block_group, path, start,
1042 size);
1043 mutex_unlock(&block_group->free_space_lock);
1044
1045 btrfs_put_block_group(block_group);
1046out:
1047 btrfs_free_path(path);
1048 if (ret)
Jeff Mahoney66642832016-06-10 18:19:25 -04001049 btrfs_abort_transaction(trans, ret);
Omar Sandovala5ed9182015-09-29 20:50:35 -07001050 return ret;
1051}
1052
1053/*
1054 * Populate the free space tree by walking the extent tree. Operations on the
1055 * extent tree that happen as a result of writes to the free space tree will go
1056 * through the normal add/remove hooks.
1057 */
1058static int populate_free_space_tree(struct btrfs_trans_handle *trans,
1059 struct btrfs_fs_info *fs_info,
1060 struct btrfs_block_group_cache *block_group)
1061{
1062 struct btrfs_root *extent_root = fs_info->extent_root;
1063 struct btrfs_path *path, *path2;
1064 struct btrfs_key key;
1065 u64 start, end;
1066 int ret;
1067
1068 path = btrfs_alloc_path();
1069 if (!path)
1070 return -ENOMEM;
1071 path->reada = 1;
1072
1073 path2 = btrfs_alloc_path();
1074 if (!path2) {
1075 btrfs_free_path(path);
1076 return -ENOMEM;
1077 }
1078
1079 ret = add_new_free_space_info(trans, fs_info, block_group, path2);
1080 if (ret)
1081 goto out;
1082
Chris Mason511711a2015-12-30 07:52:35 -08001083 mutex_lock(&block_group->free_space_lock);
1084
Omar Sandovala5ed9182015-09-29 20:50:35 -07001085 /*
1086 * Iterate through all of the extent and metadata items in this block
1087 * group, adding the free space between them and the free space at the
1088 * end. Note that EXTENT_ITEM and METADATA_ITEM are less than
1089 * BLOCK_GROUP_ITEM, so an extent may precede the block group that it's
1090 * contained in.
1091 */
1092 key.objectid = block_group->key.objectid;
1093 key.type = BTRFS_EXTENT_ITEM_KEY;
1094 key.offset = 0;
1095
1096 ret = btrfs_search_slot_for_read(extent_root, &key, path, 1, 0);
1097 if (ret < 0)
Chris Mason511711a2015-12-30 07:52:35 -08001098 goto out_locked;
Omar Sandovala5ed9182015-09-29 20:50:35 -07001099 ASSERT(ret == 0);
1100
1101 start = block_group->key.objectid;
1102 end = block_group->key.objectid + block_group->key.offset;
1103 while (1) {
1104 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1105
1106 if (key.type == BTRFS_EXTENT_ITEM_KEY ||
1107 key.type == BTRFS_METADATA_ITEM_KEY) {
1108 if (key.objectid >= end)
1109 break;
1110
1111 if (start < key.objectid) {
1112 ret = __add_to_free_space_tree(trans, fs_info,
1113 block_group,
1114 path2, start,
1115 key.objectid -
1116 start);
1117 if (ret)
Chris Mason511711a2015-12-30 07:52:35 -08001118 goto out_locked;
Omar Sandovala5ed9182015-09-29 20:50:35 -07001119 }
1120 start = key.objectid;
1121 if (key.type == BTRFS_METADATA_ITEM_KEY)
1122 start += fs_info->tree_root->nodesize;
1123 else
1124 start += key.offset;
1125 } else if (key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) {
1126 if (key.objectid != block_group->key.objectid)
1127 break;
1128 }
1129
1130 ret = btrfs_next_item(extent_root, path);
1131 if (ret < 0)
Chris Mason511711a2015-12-30 07:52:35 -08001132 goto out_locked;
Omar Sandovala5ed9182015-09-29 20:50:35 -07001133 if (ret)
1134 break;
1135 }
1136 if (start < end) {
1137 ret = __add_to_free_space_tree(trans, fs_info, block_group,
1138 path2, start, end - start);
1139 if (ret)
Chris Mason511711a2015-12-30 07:52:35 -08001140 goto out_locked;
Omar Sandovala5ed9182015-09-29 20:50:35 -07001141 }
1142
1143 ret = 0;
Chris Mason511711a2015-12-30 07:52:35 -08001144out_locked:
1145 mutex_unlock(&block_group->free_space_lock);
Omar Sandovala5ed9182015-09-29 20:50:35 -07001146out:
1147 btrfs_free_path(path2);
1148 btrfs_free_path(path);
1149 return ret;
1150}
1151
1152int btrfs_create_free_space_tree(struct btrfs_fs_info *fs_info)
1153{
1154 struct btrfs_trans_handle *trans;
1155 struct btrfs_root *tree_root = fs_info->tree_root;
1156 struct btrfs_root *free_space_root;
1157 struct btrfs_block_group_cache *block_group;
1158 struct rb_node *node;
1159 int ret;
1160
1161 trans = btrfs_start_transaction(tree_root, 0);
1162 if (IS_ERR(trans))
1163 return PTR_ERR(trans);
1164
Chris Mason511711a2015-12-30 07:52:35 -08001165 fs_info->creating_free_space_tree = 1;
Omar Sandovala5ed9182015-09-29 20:50:35 -07001166 free_space_root = btrfs_create_tree(trans, fs_info,
1167 BTRFS_FREE_SPACE_TREE_OBJECTID);
1168 if (IS_ERR(free_space_root)) {
1169 ret = PTR_ERR(free_space_root);
1170 goto abort;
1171 }
1172 fs_info->free_space_root = free_space_root;
1173
1174 node = rb_first(&fs_info->block_group_cache_tree);
1175 while (node) {
1176 block_group = rb_entry(node, struct btrfs_block_group_cache,
1177 cache_node);
1178 ret = populate_free_space_tree(trans, fs_info, block_group);
1179 if (ret)
1180 goto abort;
1181 node = rb_next(node);
1182 }
1183
1184 btrfs_set_fs_compat_ro(fs_info, FREE_SPACE_TREE);
Chris Mason511711a2015-12-30 07:52:35 -08001185 fs_info->creating_free_space_tree = 0;
Omar Sandovala5ed9182015-09-29 20:50:35 -07001186
1187 ret = btrfs_commit_transaction(trans, tree_root);
1188 if (ret)
1189 return ret;
1190
1191 return 0;
1192
1193abort:
Chris Mason511711a2015-12-30 07:52:35 -08001194 fs_info->creating_free_space_tree = 0;
Jeff Mahoney66642832016-06-10 18:19:25 -04001195 btrfs_abort_transaction(trans, ret);
Omar Sandovala5ed9182015-09-29 20:50:35 -07001196 btrfs_end_transaction(trans, tree_root);
1197 return ret;
1198}
1199
1200static int clear_free_space_tree(struct btrfs_trans_handle *trans,
1201 struct btrfs_root *root)
1202{
1203 struct btrfs_path *path;
1204 struct btrfs_key key;
1205 int nr;
1206 int ret;
1207
1208 path = btrfs_alloc_path();
1209 if (!path)
1210 return -ENOMEM;
1211
1212 path->leave_spinning = 1;
1213
1214 key.objectid = 0;
1215 key.type = 0;
1216 key.offset = 0;
1217
1218 while (1) {
1219 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1220 if (ret < 0)
1221 goto out;
1222
1223 nr = btrfs_header_nritems(path->nodes[0]);
1224 if (!nr)
1225 break;
1226
1227 path->slots[0] = 0;
1228 ret = btrfs_del_items(trans, root, path, 0, nr);
1229 if (ret)
1230 goto out;
1231
1232 btrfs_release_path(path);
1233 }
1234
1235 ret = 0;
1236out:
1237 btrfs_free_path(path);
1238 return ret;
1239}
1240
1241int btrfs_clear_free_space_tree(struct btrfs_fs_info *fs_info)
1242{
1243 struct btrfs_trans_handle *trans;
1244 struct btrfs_root *tree_root = fs_info->tree_root;
1245 struct btrfs_root *free_space_root = fs_info->free_space_root;
1246 int ret;
1247
1248 trans = btrfs_start_transaction(tree_root, 0);
1249 if (IS_ERR(trans))
1250 return PTR_ERR(trans);
1251
1252 btrfs_clear_fs_compat_ro(fs_info, FREE_SPACE_TREE);
Omar Sandovala5ed9182015-09-29 20:50:35 -07001253 fs_info->free_space_root = NULL;
1254
1255 ret = clear_free_space_tree(trans, free_space_root);
1256 if (ret)
1257 goto abort;
1258
1259 ret = btrfs_del_root(trans, tree_root, &free_space_root->root_key);
1260 if (ret)
1261 goto abort;
1262
1263 list_del(&free_space_root->dirty_list);
1264
1265 btrfs_tree_lock(free_space_root->node);
1266 clean_tree_block(trans, tree_root->fs_info, free_space_root->node);
1267 btrfs_tree_unlock(free_space_root->node);
1268 btrfs_free_tree_block(trans, free_space_root, free_space_root->node,
1269 0, 1);
1270
1271 free_extent_buffer(free_space_root->node);
1272 free_extent_buffer(free_space_root->commit_root);
1273 kfree(free_space_root);
1274
1275 ret = btrfs_commit_transaction(trans, tree_root);
1276 if (ret)
1277 return ret;
1278
1279 return 0;
1280
1281abort:
Jeff Mahoney66642832016-06-10 18:19:25 -04001282 btrfs_abort_transaction(trans, ret);
Omar Sandovala5ed9182015-09-29 20:50:35 -07001283 btrfs_end_transaction(trans, tree_root);
1284 return ret;
1285}
1286
1287static int __add_block_group_free_space(struct btrfs_trans_handle *trans,
1288 struct btrfs_fs_info *fs_info,
1289 struct btrfs_block_group_cache *block_group,
1290 struct btrfs_path *path)
1291{
1292 u64 start, end;
1293 int ret;
1294
1295 start = block_group->key.objectid;
1296 end = block_group->key.objectid + block_group->key.offset;
1297
1298 block_group->needs_free_space = 0;
1299
1300 ret = add_new_free_space_info(trans, fs_info, block_group, path);
1301 if (ret)
1302 return ret;
1303
1304 return __add_to_free_space_tree(trans, fs_info, block_group, path,
1305 block_group->key.objectid,
1306 block_group->key.offset);
1307}
1308
1309int add_block_group_free_space(struct btrfs_trans_handle *trans,
1310 struct btrfs_fs_info *fs_info,
1311 struct btrfs_block_group_cache *block_group)
1312{
1313 struct btrfs_path *path = NULL;
1314 int ret = 0;
1315
1316 if (!btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE))
1317 return 0;
1318
1319 mutex_lock(&block_group->free_space_lock);
1320 if (!block_group->needs_free_space)
1321 goto out;
1322
1323 path = btrfs_alloc_path();
1324 if (!path) {
1325 ret = -ENOMEM;
1326 goto out;
1327 }
1328
1329 ret = __add_block_group_free_space(trans, fs_info, block_group, path);
1330
1331out:
1332 btrfs_free_path(path);
1333 mutex_unlock(&block_group->free_space_lock);
1334 if (ret)
Jeff Mahoney66642832016-06-10 18:19:25 -04001335 btrfs_abort_transaction(trans, ret);
Omar Sandovala5ed9182015-09-29 20:50:35 -07001336 return ret;
1337}
1338
1339int remove_block_group_free_space(struct btrfs_trans_handle *trans,
1340 struct btrfs_fs_info *fs_info,
1341 struct btrfs_block_group_cache *block_group)
1342{
1343 struct btrfs_root *root = fs_info->free_space_root;
1344 struct btrfs_path *path;
1345 struct btrfs_key key, found_key;
1346 struct extent_buffer *leaf;
1347 u64 start, end;
1348 int done = 0, nr;
1349 int ret;
1350
1351 if (!btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE))
1352 return 0;
1353
1354 if (block_group->needs_free_space) {
1355 /* We never added this block group to the free space tree. */
1356 return 0;
1357 }
1358
1359 path = btrfs_alloc_path();
1360 if (!path) {
1361 ret = -ENOMEM;
1362 goto out;
1363 }
1364
1365 start = block_group->key.objectid;
1366 end = block_group->key.objectid + block_group->key.offset;
1367
1368 key.objectid = end - 1;
1369 key.type = (u8)-1;
1370 key.offset = (u64)-1;
1371
1372 while (!done) {
1373 ret = btrfs_search_prev_slot(trans, root, &key, path, -1, 1);
1374 if (ret)
1375 goto out;
1376
1377 leaf = path->nodes[0];
1378 nr = 0;
1379 path->slots[0]++;
1380 while (path->slots[0] > 0) {
1381 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0] - 1);
1382
1383 if (found_key.type == BTRFS_FREE_SPACE_INFO_KEY) {
1384 ASSERT(found_key.objectid == block_group->key.objectid);
1385 ASSERT(found_key.offset == block_group->key.offset);
1386 done = 1;
1387 nr++;
1388 path->slots[0]--;
1389 break;
1390 } else if (found_key.type == BTRFS_FREE_SPACE_EXTENT_KEY ||
1391 found_key.type == BTRFS_FREE_SPACE_BITMAP_KEY) {
1392 ASSERT(found_key.objectid >= start);
1393 ASSERT(found_key.objectid < end);
1394 ASSERT(found_key.objectid + found_key.offset <= end);
1395 nr++;
1396 path->slots[0]--;
1397 } else {
1398 ASSERT(0);
1399 }
1400 }
1401
1402 ret = btrfs_del_items(trans, root, path, path->slots[0], nr);
1403 if (ret)
1404 goto out;
1405 btrfs_release_path(path);
1406 }
1407
1408 ret = 0;
1409out:
1410 btrfs_free_path(path);
1411 if (ret)
Jeff Mahoney66642832016-06-10 18:19:25 -04001412 btrfs_abort_transaction(trans, ret);
Omar Sandovala5ed9182015-09-29 20:50:35 -07001413 return ret;
1414}
1415
1416static int load_free_space_bitmaps(struct btrfs_caching_control *caching_ctl,
1417 struct btrfs_path *path,
1418 u32 expected_extent_count)
1419{
1420 struct btrfs_block_group_cache *block_group;
1421 struct btrfs_fs_info *fs_info;
1422 struct btrfs_root *root;
1423 struct btrfs_key key;
1424 int prev_bit = 0, bit;
1425 /* Initialize to silence GCC. */
1426 u64 extent_start = 0;
1427 u64 end, offset;
1428 u64 total_found = 0;
1429 u32 extent_count = 0;
1430 int ret;
1431
1432 block_group = caching_ctl->block_group;
1433 fs_info = block_group->fs_info;
1434 root = fs_info->free_space_root;
1435
1436 end = block_group->key.objectid + block_group->key.offset;
1437
1438 while (1) {
1439 ret = btrfs_next_item(root, path);
1440 if (ret < 0)
1441 goto out;
1442 if (ret)
1443 break;
1444
1445 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1446
1447 if (key.type == BTRFS_FREE_SPACE_INFO_KEY)
1448 break;
1449
1450 ASSERT(key.type == BTRFS_FREE_SPACE_BITMAP_KEY);
1451 ASSERT(key.objectid < end && key.objectid + key.offset <= end);
1452
1453 caching_ctl->progress = key.objectid;
1454
1455 offset = key.objectid;
1456 while (offset < key.objectid + key.offset) {
1457 bit = free_space_test_bit(block_group, path, offset);
1458 if (prev_bit == 0 && bit == 1) {
1459 extent_start = offset;
1460 } else if (prev_bit == 1 && bit == 0) {
1461 total_found += add_new_free_space(block_group,
1462 fs_info,
1463 extent_start,
1464 offset);
1465 if (total_found > CACHING_CTL_WAKE_UP) {
1466 total_found = 0;
1467 wake_up(&caching_ctl->wait);
1468 }
1469 extent_count++;
1470 }
1471 prev_bit = bit;
1472 offset += block_group->sectorsize;
1473 }
1474 }
1475 if (prev_bit == 1) {
1476 total_found += add_new_free_space(block_group, fs_info,
1477 extent_start, end);
1478 extent_count++;
1479 }
1480
1481 if (extent_count != expected_extent_count) {
1482 btrfs_err(fs_info, "incorrect extent count for %llu; counted %u, expected %u",
1483 block_group->key.objectid, extent_count,
1484 expected_extent_count);
1485 ASSERT(0);
1486 ret = -EIO;
1487 goto out;
1488 }
1489
1490 caching_ctl->progress = (u64)-1;
1491
1492 ret = 0;
1493out:
1494 return ret;
1495}
1496
1497static int load_free_space_extents(struct btrfs_caching_control *caching_ctl,
1498 struct btrfs_path *path,
1499 u32 expected_extent_count)
1500{
1501 struct btrfs_block_group_cache *block_group;
1502 struct btrfs_fs_info *fs_info;
1503 struct btrfs_root *root;
1504 struct btrfs_key key;
1505 u64 end;
1506 u64 total_found = 0;
1507 u32 extent_count = 0;
1508 int ret;
1509
1510 block_group = caching_ctl->block_group;
1511 fs_info = block_group->fs_info;
1512 root = fs_info->free_space_root;
1513
1514 end = block_group->key.objectid + block_group->key.offset;
1515
1516 while (1) {
1517 ret = btrfs_next_item(root, path);
1518 if (ret < 0)
1519 goto out;
1520 if (ret)
1521 break;
1522
1523 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1524
1525 if (key.type == BTRFS_FREE_SPACE_INFO_KEY)
1526 break;
1527
1528 ASSERT(key.type == BTRFS_FREE_SPACE_EXTENT_KEY);
1529 ASSERT(key.objectid < end && key.objectid + key.offset <= end);
1530
1531 caching_ctl->progress = key.objectid;
1532
1533 total_found += add_new_free_space(block_group, fs_info,
1534 key.objectid,
1535 key.objectid + key.offset);
1536 if (total_found > CACHING_CTL_WAKE_UP) {
1537 total_found = 0;
1538 wake_up(&caching_ctl->wait);
1539 }
1540 extent_count++;
1541 }
1542
1543 if (extent_count != expected_extent_count) {
1544 btrfs_err(fs_info, "incorrect extent count for %llu; counted %u, expected %u",
1545 block_group->key.objectid, extent_count,
1546 expected_extent_count);
1547 ASSERT(0);
1548 ret = -EIO;
1549 goto out;
1550 }
1551
1552 caching_ctl->progress = (u64)-1;
1553
1554 ret = 0;
1555out:
1556 return ret;
1557}
1558
1559int load_free_space_tree(struct btrfs_caching_control *caching_ctl)
1560{
1561 struct btrfs_block_group_cache *block_group;
1562 struct btrfs_fs_info *fs_info;
1563 struct btrfs_free_space_info *info;
1564 struct btrfs_path *path;
1565 u32 extent_count, flags;
1566 int ret;
1567
1568 block_group = caching_ctl->block_group;
1569 fs_info = block_group->fs_info;
1570
1571 path = btrfs_alloc_path();
1572 if (!path)
1573 return -ENOMEM;
1574
1575 /*
1576 * Just like caching_thread() doesn't want to deadlock on the extent
1577 * tree, we don't want to deadlock on the free space tree.
1578 */
1579 path->skip_locking = 1;
1580 path->search_commit_root = 1;
1581 path->reada = 1;
1582
1583 info = search_free_space_info(NULL, fs_info, block_group, path, 0);
1584 if (IS_ERR(info)) {
1585 ret = PTR_ERR(info);
1586 goto out;
1587 }
1588 extent_count = btrfs_free_space_extent_count(path->nodes[0], info);
1589 flags = btrfs_free_space_flags(path->nodes[0], info);
1590
1591 /*
1592 * We left path pointing to the free space info item, so now
1593 * load_free_space_foo can just iterate through the free space tree from
1594 * there.
1595 */
1596 if (flags & BTRFS_FREE_SPACE_USING_BITMAPS)
1597 ret = load_free_space_bitmaps(caching_ctl, path, extent_count);
1598 else
1599 ret = load_free_space_extents(caching_ctl, path, extent_count);
1600
1601out:
1602 btrfs_free_path(path);
1603 return ret;
1604}