Commit | Line | Data |
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c1d7c514 | 1 | // SPDX-License-Identifier: GPL-2.0 |
a5ed9182 OS |
2 | /* |
3 | * Copyright (C) 2015 Facebook. All rights reserved. | |
a5ed9182 OS |
4 | */ |
5 | ||
6 | #include <linux/kernel.h> | |
25ff17e8 | 7 | #include <linux/sched/mm.h> |
a5ed9182 OS |
8 | #include "ctree.h" |
9 | #include "disk-io.h" | |
10 | #include "locking.h" | |
11 | #include "free-space-tree.h" | |
12 | #include "transaction.h" | |
13 | ||
14 | static int __add_block_group_free_space(struct btrfs_trans_handle *trans, | |
15 | struct btrfs_fs_info *fs_info, | |
16 | struct btrfs_block_group_cache *block_group, | |
17 | struct btrfs_path *path); | |
18 | ||
19 | void set_free_space_tree_thresholds(struct btrfs_block_group_cache *cache) | |
20 | { | |
21 | u32 bitmap_range; | |
22 | size_t bitmap_size; | |
23 | u64 num_bitmaps, total_bitmap_size; | |
24 | ||
25 | /* | |
26 | * We convert to bitmaps when the disk space required for using extents | |
27 | * exceeds that required for using bitmaps. | |
28 | */ | |
da17066c | 29 | bitmap_range = cache->fs_info->sectorsize * BTRFS_FREE_SPACE_BITMAP_BITS; |
a5ed9182 OS |
30 | num_bitmaps = div_u64(cache->key.offset + bitmap_range - 1, |
31 | bitmap_range); | |
32 | bitmap_size = sizeof(struct btrfs_item) + BTRFS_FREE_SPACE_BITMAP_SIZE; | |
33 | total_bitmap_size = num_bitmaps * bitmap_size; | |
34 | cache->bitmap_high_thresh = div_u64(total_bitmap_size, | |
35 | sizeof(struct btrfs_item)); | |
36 | ||
37 | /* | |
38 | * We allow for a small buffer between the high threshold and low | |
39 | * threshold to avoid thrashing back and forth between the two formats. | |
40 | */ | |
41 | if (cache->bitmap_high_thresh > 100) | |
42 | cache->bitmap_low_thresh = cache->bitmap_high_thresh - 100; | |
43 | else | |
44 | cache->bitmap_low_thresh = 0; | |
45 | } | |
46 | ||
47 | static int add_new_free_space_info(struct btrfs_trans_handle *trans, | |
48 | struct btrfs_fs_info *fs_info, | |
49 | struct btrfs_block_group_cache *block_group, | |
50 | struct btrfs_path *path) | |
51 | { | |
52 | struct btrfs_root *root = fs_info->free_space_root; | |
53 | struct btrfs_free_space_info *info; | |
54 | struct btrfs_key key; | |
55 | struct extent_buffer *leaf; | |
56 | int ret; | |
57 | ||
58 | key.objectid = block_group->key.objectid; | |
59 | key.type = BTRFS_FREE_SPACE_INFO_KEY; | |
60 | key.offset = block_group->key.offset; | |
61 | ||
62 | ret = btrfs_insert_empty_item(trans, root, path, &key, sizeof(*info)); | |
63 | if (ret) | |
64 | goto out; | |
65 | ||
66 | leaf = path->nodes[0]; | |
67 | info = btrfs_item_ptr(leaf, path->slots[0], | |
68 | struct btrfs_free_space_info); | |
69 | btrfs_set_free_space_extent_count(leaf, info, 0); | |
70 | btrfs_set_free_space_flags(leaf, info, 0); | |
71 | btrfs_mark_buffer_dirty(leaf); | |
72 | ||
73 | ret = 0; | |
74 | out: | |
75 | btrfs_release_path(path); | |
76 | return ret; | |
77 | } | |
78 | ||
79 | struct btrfs_free_space_info * | |
80 | search_free_space_info(struct btrfs_trans_handle *trans, | |
81 | struct btrfs_fs_info *fs_info, | |
82 | struct btrfs_block_group_cache *block_group, | |
83 | struct btrfs_path *path, int cow) | |
84 | { | |
85 | struct btrfs_root *root = fs_info->free_space_root; | |
86 | struct btrfs_key key; | |
87 | int ret; | |
88 | ||
89 | key.objectid = block_group->key.objectid; | |
90 | key.type = BTRFS_FREE_SPACE_INFO_KEY; | |
91 | key.offset = block_group->key.offset; | |
92 | ||
93 | ret = btrfs_search_slot(trans, root, &key, path, 0, cow); | |
94 | if (ret < 0) | |
95 | return ERR_PTR(ret); | |
96 | if (ret != 0) { | |
ab8d0fc4 | 97 | btrfs_warn(fs_info, "missing free space info for %llu", |
a5ed9182 OS |
98 | block_group->key.objectid); |
99 | ASSERT(0); | |
100 | return ERR_PTR(-ENOENT); | |
101 | } | |
102 | ||
103 | return btrfs_item_ptr(path->nodes[0], path->slots[0], | |
104 | struct btrfs_free_space_info); | |
105 | } | |
106 | ||
107 | /* | |
108 | * btrfs_search_slot() but we're looking for the greatest key less than the | |
109 | * passed key. | |
110 | */ | |
111 | static int btrfs_search_prev_slot(struct btrfs_trans_handle *trans, | |
112 | struct btrfs_root *root, | |
113 | struct btrfs_key *key, struct btrfs_path *p, | |
114 | int ins_len, int cow) | |
115 | { | |
116 | int ret; | |
117 | ||
118 | ret = btrfs_search_slot(trans, root, key, p, ins_len, cow); | |
119 | if (ret < 0) | |
120 | return ret; | |
121 | ||
122 | if (ret == 0) { | |
123 | ASSERT(0); | |
124 | return -EIO; | |
125 | } | |
126 | ||
127 | if (p->slots[0] == 0) { | |
128 | ASSERT(0); | |
129 | return -EIO; | |
130 | } | |
131 | p->slots[0]--; | |
132 | ||
133 | return 0; | |
134 | } | |
135 | ||
136 | static inline u32 free_space_bitmap_size(u64 size, u32 sectorsize) | |
137 | { | |
138 | return DIV_ROUND_UP((u32)div_u64(size, sectorsize), BITS_PER_BYTE); | |
139 | } | |
140 | ||
2fe1d551 | 141 | static u8 *alloc_bitmap(u32 bitmap_size) |
a5ed9182 | 142 | { |
25ff17e8 OS |
143 | u8 *ret; |
144 | unsigned int nofs_flag; | |
79b134a2 DS |
145 | |
146 | /* | |
25ff17e8 OS |
147 | * GFP_NOFS doesn't work with kvmalloc(), but we really can't recurse |
148 | * into the filesystem as the free space bitmap can be modified in the | |
149 | * critical section of a transaction commit. | |
150 | * | |
151 | * TODO: push the memalloc_nofs_{save,restore}() to the caller where we | |
152 | * know that recursion is unsafe. | |
79b134a2 | 153 | */ |
25ff17e8 OS |
154 | nofs_flag = memalloc_nofs_save(); |
155 | ret = kvzalloc(bitmap_size, GFP_KERNEL); | |
156 | memalloc_nofs_restore(nofs_flag); | |
157 | return ret; | |
a5ed9182 OS |
158 | } |
159 | ||
160 | int convert_free_space_to_bitmaps(struct btrfs_trans_handle *trans, | |
161 | struct btrfs_fs_info *fs_info, | |
162 | struct btrfs_block_group_cache *block_group, | |
163 | struct btrfs_path *path) | |
164 | { | |
165 | struct btrfs_root *root = fs_info->free_space_root; | |
166 | struct btrfs_free_space_info *info; | |
167 | struct btrfs_key key, found_key; | |
168 | struct extent_buffer *leaf; | |
2fe1d551 | 169 | u8 *bitmap, *bitmap_cursor; |
a5ed9182 OS |
170 | u64 start, end; |
171 | u64 bitmap_range, i; | |
172 | u32 bitmap_size, flags, expected_extent_count; | |
173 | u32 extent_count = 0; | |
174 | int done = 0, nr; | |
175 | int ret; | |
176 | ||
177 | bitmap_size = free_space_bitmap_size(block_group->key.offset, | |
0b246afa | 178 | fs_info->sectorsize); |
a5ed9182 OS |
179 | bitmap = alloc_bitmap(bitmap_size); |
180 | if (!bitmap) { | |
181 | ret = -ENOMEM; | |
182 | goto out; | |
183 | } | |
184 | ||
185 | start = block_group->key.objectid; | |
186 | end = block_group->key.objectid + block_group->key.offset; | |
187 | ||
188 | key.objectid = end - 1; | |
189 | key.type = (u8)-1; | |
190 | key.offset = (u64)-1; | |
191 | ||
192 | while (!done) { | |
193 | ret = btrfs_search_prev_slot(trans, root, &key, path, -1, 1); | |
194 | if (ret) | |
195 | goto out; | |
196 | ||
197 | leaf = path->nodes[0]; | |
198 | nr = 0; | |
199 | path->slots[0]++; | |
200 | while (path->slots[0] > 0) { | |
201 | btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0] - 1); | |
202 | ||
203 | if (found_key.type == BTRFS_FREE_SPACE_INFO_KEY) { | |
204 | ASSERT(found_key.objectid == block_group->key.objectid); | |
205 | ASSERT(found_key.offset == block_group->key.offset); | |
206 | done = 1; | |
207 | break; | |
208 | } else if (found_key.type == BTRFS_FREE_SPACE_EXTENT_KEY) { | |
209 | u64 first, last; | |
210 | ||
211 | ASSERT(found_key.objectid >= start); | |
212 | ASSERT(found_key.objectid < end); | |
213 | ASSERT(found_key.objectid + found_key.offset <= end); | |
214 | ||
215 | first = div_u64(found_key.objectid - start, | |
0b246afa | 216 | fs_info->sectorsize); |
a5ed9182 | 217 | last = div_u64(found_key.objectid + found_key.offset - start, |
0b246afa | 218 | fs_info->sectorsize); |
2fe1d551 | 219 | le_bitmap_set(bitmap, first, last - first); |
a5ed9182 OS |
220 | |
221 | extent_count++; | |
222 | nr++; | |
223 | path->slots[0]--; | |
224 | } else { | |
225 | ASSERT(0); | |
226 | } | |
227 | } | |
228 | ||
229 | ret = btrfs_del_items(trans, root, path, path->slots[0], nr); | |
230 | if (ret) | |
231 | goto out; | |
232 | btrfs_release_path(path); | |
233 | } | |
234 | ||
235 | info = search_free_space_info(trans, fs_info, block_group, path, 1); | |
236 | if (IS_ERR(info)) { | |
237 | ret = PTR_ERR(info); | |
238 | goto out; | |
239 | } | |
240 | leaf = path->nodes[0]; | |
241 | flags = btrfs_free_space_flags(leaf, info); | |
242 | flags |= BTRFS_FREE_SPACE_USING_BITMAPS; | |
243 | btrfs_set_free_space_flags(leaf, info, flags); | |
244 | expected_extent_count = btrfs_free_space_extent_count(leaf, info); | |
245 | btrfs_mark_buffer_dirty(leaf); | |
246 | btrfs_release_path(path); | |
247 | ||
248 | if (extent_count != expected_extent_count) { | |
5d163e0e JM |
249 | btrfs_err(fs_info, |
250 | "incorrect extent count for %llu; counted %u, expected %u", | |
a5ed9182 OS |
251 | block_group->key.objectid, extent_count, |
252 | expected_extent_count); | |
253 | ASSERT(0); | |
254 | ret = -EIO; | |
255 | goto out; | |
256 | } | |
257 | ||
2fe1d551 | 258 | bitmap_cursor = bitmap; |
0b246afa | 259 | bitmap_range = fs_info->sectorsize * BTRFS_FREE_SPACE_BITMAP_BITS; |
a5ed9182 OS |
260 | i = start; |
261 | while (i < end) { | |
262 | unsigned long ptr; | |
263 | u64 extent_size; | |
264 | u32 data_size; | |
265 | ||
266 | extent_size = min(end - i, bitmap_range); | |
267 | data_size = free_space_bitmap_size(extent_size, | |
0b246afa | 268 | fs_info->sectorsize); |
a5ed9182 OS |
269 | |
270 | key.objectid = i; | |
271 | key.type = BTRFS_FREE_SPACE_BITMAP_KEY; | |
272 | key.offset = extent_size; | |
273 | ||
274 | ret = btrfs_insert_empty_item(trans, root, path, &key, | |
275 | data_size); | |
276 | if (ret) | |
277 | goto out; | |
278 | ||
279 | leaf = path->nodes[0]; | |
280 | ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); | |
281 | write_extent_buffer(leaf, bitmap_cursor, ptr, | |
282 | data_size); | |
283 | btrfs_mark_buffer_dirty(leaf); | |
284 | btrfs_release_path(path); | |
285 | ||
286 | i += extent_size; | |
287 | bitmap_cursor += data_size; | |
288 | } | |
289 | ||
290 | ret = 0; | |
291 | out: | |
79b134a2 | 292 | kvfree(bitmap); |
a5ed9182 | 293 | if (ret) |
66642832 | 294 | btrfs_abort_transaction(trans, ret); |
a5ed9182 OS |
295 | return ret; |
296 | } | |
297 | ||
298 | int convert_free_space_to_extents(struct btrfs_trans_handle *trans, | |
299 | struct btrfs_fs_info *fs_info, | |
300 | struct btrfs_block_group_cache *block_group, | |
301 | struct btrfs_path *path) | |
302 | { | |
303 | struct btrfs_root *root = fs_info->free_space_root; | |
304 | struct btrfs_free_space_info *info; | |
305 | struct btrfs_key key, found_key; | |
306 | struct extent_buffer *leaf; | |
2fe1d551 | 307 | u8 *bitmap; |
a5ed9182 OS |
308 | u64 start, end; |
309 | /* Initialize to silence GCC. */ | |
310 | u64 extent_start = 0; | |
311 | u64 offset; | |
312 | u32 bitmap_size, flags, expected_extent_count; | |
313 | int prev_bit = 0, bit, bitnr; | |
314 | u32 extent_count = 0; | |
315 | int done = 0, nr; | |
316 | int ret; | |
317 | ||
318 | bitmap_size = free_space_bitmap_size(block_group->key.offset, | |
0b246afa | 319 | fs_info->sectorsize); |
a5ed9182 OS |
320 | bitmap = alloc_bitmap(bitmap_size); |
321 | if (!bitmap) { | |
322 | ret = -ENOMEM; | |
323 | goto out; | |
324 | } | |
325 | ||
326 | start = block_group->key.objectid; | |
327 | end = block_group->key.objectid + block_group->key.offset; | |
328 | ||
329 | key.objectid = end - 1; | |
330 | key.type = (u8)-1; | |
331 | key.offset = (u64)-1; | |
332 | ||
333 | while (!done) { | |
334 | ret = btrfs_search_prev_slot(trans, root, &key, path, -1, 1); | |
335 | if (ret) | |
336 | goto out; | |
337 | ||
338 | leaf = path->nodes[0]; | |
339 | nr = 0; | |
340 | path->slots[0]++; | |
341 | while (path->slots[0] > 0) { | |
342 | btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0] - 1); | |
343 | ||
344 | if (found_key.type == BTRFS_FREE_SPACE_INFO_KEY) { | |
345 | ASSERT(found_key.objectid == block_group->key.objectid); | |
346 | ASSERT(found_key.offset == block_group->key.offset); | |
347 | done = 1; | |
348 | break; | |
349 | } else if (found_key.type == BTRFS_FREE_SPACE_BITMAP_KEY) { | |
350 | unsigned long ptr; | |
2fe1d551 | 351 | u8 *bitmap_cursor; |
a5ed9182 OS |
352 | u32 bitmap_pos, data_size; |
353 | ||
354 | ASSERT(found_key.objectid >= start); | |
355 | ASSERT(found_key.objectid < end); | |
356 | ASSERT(found_key.objectid + found_key.offset <= end); | |
357 | ||
358 | bitmap_pos = div_u64(found_key.objectid - start, | |
0b246afa | 359 | fs_info->sectorsize * |
a5ed9182 | 360 | BITS_PER_BYTE); |
2fe1d551 | 361 | bitmap_cursor = bitmap + bitmap_pos; |
a5ed9182 | 362 | data_size = free_space_bitmap_size(found_key.offset, |
0b246afa | 363 | fs_info->sectorsize); |
a5ed9182 OS |
364 | |
365 | ptr = btrfs_item_ptr_offset(leaf, path->slots[0] - 1); | |
366 | read_extent_buffer(leaf, bitmap_cursor, ptr, | |
367 | data_size); | |
368 | ||
369 | nr++; | |
370 | path->slots[0]--; | |
371 | } else { | |
372 | ASSERT(0); | |
373 | } | |
374 | } | |
375 | ||
376 | ret = btrfs_del_items(trans, root, path, path->slots[0], nr); | |
377 | if (ret) | |
378 | goto out; | |
379 | btrfs_release_path(path); | |
380 | } | |
381 | ||
382 | info = search_free_space_info(trans, fs_info, block_group, path, 1); | |
383 | if (IS_ERR(info)) { | |
384 | ret = PTR_ERR(info); | |
385 | goto out; | |
386 | } | |
387 | leaf = path->nodes[0]; | |
388 | flags = btrfs_free_space_flags(leaf, info); | |
389 | flags &= ~BTRFS_FREE_SPACE_USING_BITMAPS; | |
390 | btrfs_set_free_space_flags(leaf, info, flags); | |
391 | expected_extent_count = btrfs_free_space_extent_count(leaf, info); | |
392 | btrfs_mark_buffer_dirty(leaf); | |
393 | btrfs_release_path(path); | |
394 | ||
395 | offset = start; | |
396 | bitnr = 0; | |
397 | while (offset < end) { | |
2fe1d551 | 398 | bit = !!le_test_bit(bitnr, bitmap); |
a5ed9182 OS |
399 | if (prev_bit == 0 && bit == 1) { |
400 | extent_start = offset; | |
401 | } else if (prev_bit == 1 && bit == 0) { | |
402 | key.objectid = extent_start; | |
403 | key.type = BTRFS_FREE_SPACE_EXTENT_KEY; | |
404 | key.offset = offset - extent_start; | |
405 | ||
406 | ret = btrfs_insert_empty_item(trans, root, path, &key, 0); | |
407 | if (ret) | |
408 | goto out; | |
409 | btrfs_release_path(path); | |
410 | ||
411 | extent_count++; | |
412 | } | |
413 | prev_bit = bit; | |
0b246afa | 414 | offset += fs_info->sectorsize; |
a5ed9182 OS |
415 | bitnr++; |
416 | } | |
417 | if (prev_bit == 1) { | |
418 | key.objectid = extent_start; | |
419 | key.type = BTRFS_FREE_SPACE_EXTENT_KEY; | |
420 | key.offset = end - extent_start; | |
421 | ||
422 | ret = btrfs_insert_empty_item(trans, root, path, &key, 0); | |
423 | if (ret) | |
424 | goto out; | |
425 | btrfs_release_path(path); | |
426 | ||
427 | extent_count++; | |
428 | } | |
429 | ||
430 | if (extent_count != expected_extent_count) { | |
5d163e0e JM |
431 | btrfs_err(fs_info, |
432 | "incorrect extent count for %llu; counted %u, expected %u", | |
a5ed9182 OS |
433 | block_group->key.objectid, extent_count, |
434 | expected_extent_count); | |
435 | ASSERT(0); | |
436 | ret = -EIO; | |
437 | goto out; | |
438 | } | |
439 | ||
440 | ret = 0; | |
441 | out: | |
79b134a2 | 442 | kvfree(bitmap); |
a5ed9182 | 443 | if (ret) |
66642832 | 444 | btrfs_abort_transaction(trans, ret); |
a5ed9182 OS |
445 | return ret; |
446 | } | |
447 | ||
448 | static int update_free_space_extent_count(struct btrfs_trans_handle *trans, | |
449 | struct btrfs_fs_info *fs_info, | |
450 | struct btrfs_block_group_cache *block_group, | |
451 | struct btrfs_path *path, | |
452 | int new_extents) | |
453 | { | |
454 | struct btrfs_free_space_info *info; | |
455 | u32 flags; | |
456 | u32 extent_count; | |
457 | int ret = 0; | |
458 | ||
459 | if (new_extents == 0) | |
460 | return 0; | |
461 | ||
462 | info = search_free_space_info(trans, fs_info, block_group, path, 1); | |
463 | if (IS_ERR(info)) { | |
464 | ret = PTR_ERR(info); | |
465 | goto out; | |
466 | } | |
467 | flags = btrfs_free_space_flags(path->nodes[0], info); | |
468 | extent_count = btrfs_free_space_extent_count(path->nodes[0], info); | |
469 | ||
470 | extent_count += new_extents; | |
471 | btrfs_set_free_space_extent_count(path->nodes[0], info, extent_count); | |
472 | btrfs_mark_buffer_dirty(path->nodes[0]); | |
473 | btrfs_release_path(path); | |
474 | ||
475 | if (!(flags & BTRFS_FREE_SPACE_USING_BITMAPS) && | |
476 | extent_count > block_group->bitmap_high_thresh) { | |
477 | ret = convert_free_space_to_bitmaps(trans, fs_info, block_group, | |
478 | path); | |
479 | } else if ((flags & BTRFS_FREE_SPACE_USING_BITMAPS) && | |
480 | extent_count < block_group->bitmap_low_thresh) { | |
481 | ret = convert_free_space_to_extents(trans, fs_info, block_group, | |
482 | path); | |
483 | } | |
484 | ||
485 | out: | |
486 | return ret; | |
487 | } | |
488 | ||
489 | int free_space_test_bit(struct btrfs_block_group_cache *block_group, | |
490 | struct btrfs_path *path, u64 offset) | |
491 | { | |
492 | struct extent_buffer *leaf; | |
493 | struct btrfs_key key; | |
494 | u64 found_start, found_end; | |
495 | unsigned long ptr, i; | |
496 | ||
497 | leaf = path->nodes[0]; | |
498 | btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); | |
499 | ASSERT(key.type == BTRFS_FREE_SPACE_BITMAP_KEY); | |
500 | ||
501 | found_start = key.objectid; | |
502 | found_end = key.objectid + key.offset; | |
503 | ASSERT(offset >= found_start && offset < found_end); | |
504 | ||
505 | ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); | |
da17066c JM |
506 | i = div_u64(offset - found_start, |
507 | block_group->fs_info->sectorsize); | |
a5ed9182 OS |
508 | return !!extent_buffer_test_bit(leaf, ptr, i); |
509 | } | |
510 | ||
511 | static void free_space_set_bits(struct btrfs_block_group_cache *block_group, | |
512 | struct btrfs_path *path, u64 *start, u64 *size, | |
513 | int bit) | |
514 | { | |
0b246afa | 515 | struct btrfs_fs_info *fs_info = block_group->fs_info; |
a5ed9182 OS |
516 | struct extent_buffer *leaf; |
517 | struct btrfs_key key; | |
518 | u64 end = *start + *size; | |
519 | u64 found_start, found_end; | |
520 | unsigned long ptr, first, last; | |
521 | ||
522 | leaf = path->nodes[0]; | |
523 | btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); | |
524 | ASSERT(key.type == BTRFS_FREE_SPACE_BITMAP_KEY); | |
525 | ||
526 | found_start = key.objectid; | |
527 | found_end = key.objectid + key.offset; | |
528 | ASSERT(*start >= found_start && *start < found_end); | |
529 | ASSERT(end > found_start); | |
530 | ||
531 | if (end > found_end) | |
532 | end = found_end; | |
533 | ||
534 | ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); | |
0b246afa JM |
535 | first = div_u64(*start - found_start, fs_info->sectorsize); |
536 | last = div_u64(end - found_start, fs_info->sectorsize); | |
a5ed9182 OS |
537 | if (bit) |
538 | extent_buffer_bitmap_set(leaf, ptr, first, last - first); | |
539 | else | |
540 | extent_buffer_bitmap_clear(leaf, ptr, first, last - first); | |
541 | btrfs_mark_buffer_dirty(leaf); | |
542 | ||
543 | *size -= end - *start; | |
544 | *start = end; | |
545 | } | |
546 | ||
547 | /* | |
548 | * We can't use btrfs_next_item() in modify_free_space_bitmap() because | |
549 | * btrfs_next_leaf() doesn't get the path for writing. We can forgo the fancy | |
550 | * tree walking in btrfs_next_leaf() anyways because we know exactly what we're | |
551 | * looking for. | |
552 | */ | |
553 | static int free_space_next_bitmap(struct btrfs_trans_handle *trans, | |
554 | struct btrfs_root *root, struct btrfs_path *p) | |
555 | { | |
556 | struct btrfs_key key; | |
557 | ||
558 | if (p->slots[0] + 1 < btrfs_header_nritems(p->nodes[0])) { | |
559 | p->slots[0]++; | |
560 | return 0; | |
561 | } | |
562 | ||
563 | btrfs_item_key_to_cpu(p->nodes[0], &key, p->slots[0]); | |
564 | btrfs_release_path(p); | |
565 | ||
566 | key.objectid += key.offset; | |
567 | key.type = (u8)-1; | |
568 | key.offset = (u64)-1; | |
569 | ||
570 | return btrfs_search_prev_slot(trans, root, &key, p, 0, 1); | |
571 | } | |
572 | ||
573 | /* | |
574 | * If remove is 1, then we are removing free space, thus clearing bits in the | |
575 | * bitmap. If remove is 0, then we are adding free space, thus setting bits in | |
576 | * the bitmap. | |
577 | */ | |
578 | static int modify_free_space_bitmap(struct btrfs_trans_handle *trans, | |
579 | struct btrfs_fs_info *fs_info, | |
580 | struct btrfs_block_group_cache *block_group, | |
581 | struct btrfs_path *path, | |
582 | u64 start, u64 size, int remove) | |
583 | { | |
584 | struct btrfs_root *root = fs_info->free_space_root; | |
585 | struct btrfs_key key; | |
586 | u64 end = start + size; | |
587 | u64 cur_start, cur_size; | |
588 | int prev_bit, next_bit; | |
589 | int new_extents; | |
590 | int ret; | |
591 | ||
592 | /* | |
593 | * Read the bit for the block immediately before the extent of space if | |
594 | * that block is within the block group. | |
595 | */ | |
596 | if (start > block_group->key.objectid) { | |
da17066c | 597 | u64 prev_block = start - block_group->fs_info->sectorsize; |
a5ed9182 OS |
598 | |
599 | key.objectid = prev_block; | |
600 | key.type = (u8)-1; | |
601 | key.offset = (u64)-1; | |
602 | ||
603 | ret = btrfs_search_prev_slot(trans, root, &key, path, 0, 1); | |
604 | if (ret) | |
605 | goto out; | |
606 | ||
607 | prev_bit = free_space_test_bit(block_group, path, prev_block); | |
608 | ||
609 | /* The previous block may have been in the previous bitmap. */ | |
610 | btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); | |
611 | if (start >= key.objectid + key.offset) { | |
612 | ret = free_space_next_bitmap(trans, root, path); | |
613 | if (ret) | |
614 | goto out; | |
615 | } | |
616 | } else { | |
617 | key.objectid = start; | |
618 | key.type = (u8)-1; | |
619 | key.offset = (u64)-1; | |
620 | ||
621 | ret = btrfs_search_prev_slot(trans, root, &key, path, 0, 1); | |
622 | if (ret) | |
623 | goto out; | |
624 | ||
625 | prev_bit = -1; | |
626 | } | |
627 | ||
628 | /* | |
629 | * Iterate over all of the bitmaps overlapped by the extent of space, | |
630 | * clearing/setting bits as required. | |
631 | */ | |
632 | cur_start = start; | |
633 | cur_size = size; | |
634 | while (1) { | |
635 | free_space_set_bits(block_group, path, &cur_start, &cur_size, | |
636 | !remove); | |
637 | if (cur_size == 0) | |
638 | break; | |
639 | ret = free_space_next_bitmap(trans, root, path); | |
640 | if (ret) | |
641 | goto out; | |
642 | } | |
643 | ||
644 | /* | |
645 | * Read the bit for the block immediately after the extent of space if | |
646 | * that block is within the block group. | |
647 | */ | |
648 | if (end < block_group->key.objectid + block_group->key.offset) { | |
649 | /* The next block may be in the next bitmap. */ | |
650 | btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); | |
651 | if (end >= key.objectid + key.offset) { | |
652 | ret = free_space_next_bitmap(trans, root, path); | |
653 | if (ret) | |
654 | goto out; | |
655 | } | |
656 | ||
657 | next_bit = free_space_test_bit(block_group, path, end); | |
658 | } else { | |
659 | next_bit = -1; | |
660 | } | |
661 | ||
662 | if (remove) { | |
663 | new_extents = -1; | |
664 | if (prev_bit == 1) { | |
665 | /* Leftover on the left. */ | |
666 | new_extents++; | |
667 | } | |
668 | if (next_bit == 1) { | |
669 | /* Leftover on the right. */ | |
670 | new_extents++; | |
671 | } | |
672 | } else { | |
673 | new_extents = 1; | |
674 | if (prev_bit == 1) { | |
675 | /* Merging with neighbor on the left. */ | |
676 | new_extents--; | |
677 | } | |
678 | if (next_bit == 1) { | |
679 | /* Merging with neighbor on the right. */ | |
680 | new_extents--; | |
681 | } | |
682 | } | |
683 | ||
684 | btrfs_release_path(path); | |
685 | ret = update_free_space_extent_count(trans, fs_info, block_group, path, | |
686 | new_extents); | |
687 | ||
688 | out: | |
689 | return ret; | |
690 | } | |
691 | ||
692 | static int remove_free_space_extent(struct btrfs_trans_handle *trans, | |
693 | struct btrfs_fs_info *fs_info, | |
694 | struct btrfs_block_group_cache *block_group, | |
695 | struct btrfs_path *path, | |
696 | u64 start, u64 size) | |
697 | { | |
698 | struct btrfs_root *root = fs_info->free_space_root; | |
699 | struct btrfs_key key; | |
700 | u64 found_start, found_end; | |
701 | u64 end = start + size; | |
702 | int new_extents = -1; | |
703 | int ret; | |
704 | ||
705 | key.objectid = start; | |
706 | key.type = (u8)-1; | |
707 | key.offset = (u64)-1; | |
708 | ||
709 | ret = btrfs_search_prev_slot(trans, root, &key, path, -1, 1); | |
710 | if (ret) | |
711 | goto out; | |
712 | ||
713 | btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); | |
714 | ||
715 | ASSERT(key.type == BTRFS_FREE_SPACE_EXTENT_KEY); | |
716 | ||
717 | found_start = key.objectid; | |
718 | found_end = key.objectid + key.offset; | |
719 | ASSERT(start >= found_start && end <= found_end); | |
720 | ||
721 | /* | |
722 | * Okay, now that we've found the free space extent which contains the | |
723 | * free space that we are removing, there are four cases: | |
724 | * | |
725 | * 1. We're using the whole extent: delete the key we found and | |
726 | * decrement the free space extent count. | |
727 | * 2. We are using part of the extent starting at the beginning: delete | |
728 | * the key we found and insert a new key representing the leftover at | |
729 | * the end. There is no net change in the number of extents. | |
730 | * 3. We are using part of the extent ending at the end: delete the key | |
731 | * we found and insert a new key representing the leftover at the | |
732 | * beginning. There is no net change in the number of extents. | |
733 | * 4. We are using part of the extent in the middle: delete the key we | |
734 | * found and insert two new keys representing the leftovers on each | |
735 | * side. Where we used to have one extent, we now have two, so increment | |
736 | * the extent count. We may need to convert the block group to bitmaps | |
737 | * as a result. | |
738 | */ | |
739 | ||
740 | /* Delete the existing key (cases 1-4). */ | |
741 | ret = btrfs_del_item(trans, root, path); | |
742 | if (ret) | |
743 | goto out; | |
744 | ||
745 | /* Add a key for leftovers at the beginning (cases 3 and 4). */ | |
746 | if (start > found_start) { | |
747 | key.objectid = found_start; | |
748 | key.type = BTRFS_FREE_SPACE_EXTENT_KEY; | |
749 | key.offset = start - found_start; | |
750 | ||
751 | btrfs_release_path(path); | |
752 | ret = btrfs_insert_empty_item(trans, root, path, &key, 0); | |
753 | if (ret) | |
754 | goto out; | |
755 | new_extents++; | |
756 | } | |
757 | ||
758 | /* Add a key for leftovers at the end (cases 2 and 4). */ | |
759 | if (end < found_end) { | |
760 | key.objectid = end; | |
761 | key.type = BTRFS_FREE_SPACE_EXTENT_KEY; | |
762 | key.offset = found_end - end; | |
763 | ||
764 | btrfs_release_path(path); | |
765 | ret = btrfs_insert_empty_item(trans, root, path, &key, 0); | |
766 | if (ret) | |
767 | goto out; | |
768 | new_extents++; | |
769 | } | |
770 | ||
771 | btrfs_release_path(path); | |
772 | ret = update_free_space_extent_count(trans, fs_info, block_group, path, | |
773 | new_extents); | |
774 | ||
775 | out: | |
776 | return ret; | |
777 | } | |
778 | ||
779 | int __remove_from_free_space_tree(struct btrfs_trans_handle *trans, | |
780 | struct btrfs_fs_info *fs_info, | |
781 | struct btrfs_block_group_cache *block_group, | |
782 | struct btrfs_path *path, u64 start, u64 size) | |
783 | { | |
784 | struct btrfs_free_space_info *info; | |
785 | u32 flags; | |
786 | int ret; | |
787 | ||
788 | if (block_group->needs_free_space) { | |
789 | ret = __add_block_group_free_space(trans, fs_info, block_group, | |
790 | path); | |
791 | if (ret) | |
792 | return ret; | |
793 | } | |
794 | ||
795 | info = search_free_space_info(NULL, fs_info, block_group, path, 0); | |
796 | if (IS_ERR(info)) | |
797 | return PTR_ERR(info); | |
798 | flags = btrfs_free_space_flags(path->nodes[0], info); | |
799 | btrfs_release_path(path); | |
800 | ||
801 | if (flags & BTRFS_FREE_SPACE_USING_BITMAPS) { | |
802 | return modify_free_space_bitmap(trans, fs_info, block_group, | |
803 | path, start, size, 1); | |
804 | } else { | |
805 | return remove_free_space_extent(trans, fs_info, block_group, | |
806 | path, start, size); | |
807 | } | |
808 | } | |
809 | ||
810 | int remove_from_free_space_tree(struct btrfs_trans_handle *trans, | |
811 | struct btrfs_fs_info *fs_info, | |
812 | u64 start, u64 size) | |
813 | { | |
814 | struct btrfs_block_group_cache *block_group; | |
815 | struct btrfs_path *path; | |
816 | int ret; | |
817 | ||
818 | if (!btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) | |
819 | return 0; | |
820 | ||
821 | path = btrfs_alloc_path(); | |
822 | if (!path) { | |
823 | ret = -ENOMEM; | |
824 | goto out; | |
825 | } | |
826 | ||
827 | block_group = btrfs_lookup_block_group(fs_info, start); | |
828 | if (!block_group) { | |
829 | ASSERT(0); | |
830 | ret = -ENOENT; | |
831 | goto out; | |
832 | } | |
833 | ||
834 | mutex_lock(&block_group->free_space_lock); | |
835 | ret = __remove_from_free_space_tree(trans, fs_info, block_group, path, | |
836 | start, size); | |
837 | mutex_unlock(&block_group->free_space_lock); | |
838 | ||
839 | btrfs_put_block_group(block_group); | |
840 | out: | |
841 | btrfs_free_path(path); | |
842 | if (ret) | |
66642832 | 843 | btrfs_abort_transaction(trans, ret); |
a5ed9182 OS |
844 | return ret; |
845 | } | |
846 | ||
847 | static int add_free_space_extent(struct btrfs_trans_handle *trans, | |
848 | struct btrfs_fs_info *fs_info, | |
849 | struct btrfs_block_group_cache *block_group, | |
850 | struct btrfs_path *path, | |
851 | u64 start, u64 size) | |
852 | { | |
853 | struct btrfs_root *root = fs_info->free_space_root; | |
854 | struct btrfs_key key, new_key; | |
855 | u64 found_start, found_end; | |
856 | u64 end = start + size; | |
857 | int new_extents = 1; | |
858 | int ret; | |
859 | ||
860 | /* | |
861 | * We are adding a new extent of free space, but we need to merge | |
862 | * extents. There are four cases here: | |
863 | * | |
864 | * 1. The new extent does not have any immediate neighbors to merge | |
865 | * with: add the new key and increment the free space extent count. We | |
866 | * may need to convert the block group to bitmaps as a result. | |
867 | * 2. The new extent has an immediate neighbor before it: remove the | |
868 | * previous key and insert a new key combining both of them. There is no | |
869 | * net change in the number of extents. | |
870 | * 3. The new extent has an immediate neighbor after it: remove the next | |
871 | * key and insert a new key combining both of them. There is no net | |
872 | * change in the number of extents. | |
873 | * 4. The new extent has immediate neighbors on both sides: remove both | |
874 | * of the keys and insert a new key combining all of them. Where we used | |
875 | * to have two extents, we now have one, so decrement the extent count. | |
876 | */ | |
877 | ||
878 | new_key.objectid = start; | |
879 | new_key.type = BTRFS_FREE_SPACE_EXTENT_KEY; | |
880 | new_key.offset = size; | |
881 | ||
882 | /* Search for a neighbor on the left. */ | |
883 | if (start == block_group->key.objectid) | |
884 | goto right; | |
885 | key.objectid = start - 1; | |
886 | key.type = (u8)-1; | |
887 | key.offset = (u64)-1; | |
888 | ||
889 | ret = btrfs_search_prev_slot(trans, root, &key, path, -1, 1); | |
890 | if (ret) | |
891 | goto out; | |
892 | ||
893 | btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); | |
894 | ||
895 | if (key.type != BTRFS_FREE_SPACE_EXTENT_KEY) { | |
896 | ASSERT(key.type == BTRFS_FREE_SPACE_INFO_KEY); | |
897 | btrfs_release_path(path); | |
898 | goto right; | |
899 | } | |
900 | ||
901 | found_start = key.objectid; | |
902 | found_end = key.objectid + key.offset; | |
903 | ASSERT(found_start >= block_group->key.objectid && | |
904 | found_end > block_group->key.objectid); | |
905 | ASSERT(found_start < start && found_end <= start); | |
906 | ||
907 | /* | |
908 | * Delete the neighbor on the left and absorb it into the new key (cases | |
909 | * 2 and 4). | |
910 | */ | |
911 | if (found_end == start) { | |
912 | ret = btrfs_del_item(trans, root, path); | |
913 | if (ret) | |
914 | goto out; | |
915 | new_key.objectid = found_start; | |
916 | new_key.offset += key.offset; | |
917 | new_extents--; | |
918 | } | |
919 | btrfs_release_path(path); | |
920 | ||
921 | right: | |
922 | /* Search for a neighbor on the right. */ | |
923 | if (end == block_group->key.objectid + block_group->key.offset) | |
924 | goto insert; | |
925 | key.objectid = end; | |
926 | key.type = (u8)-1; | |
927 | key.offset = (u64)-1; | |
928 | ||
929 | ret = btrfs_search_prev_slot(trans, root, &key, path, -1, 1); | |
930 | if (ret) | |
931 | goto out; | |
932 | ||
933 | btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); | |
934 | ||
935 | if (key.type != BTRFS_FREE_SPACE_EXTENT_KEY) { | |
936 | ASSERT(key.type == BTRFS_FREE_SPACE_INFO_KEY); | |
937 | btrfs_release_path(path); | |
938 | goto insert; | |
939 | } | |
940 | ||
941 | found_start = key.objectid; | |
942 | found_end = key.objectid + key.offset; | |
943 | ASSERT(found_start >= block_group->key.objectid && | |
944 | found_end > block_group->key.objectid); | |
945 | ASSERT((found_start < start && found_end <= start) || | |
946 | (found_start >= end && found_end > end)); | |
947 | ||
948 | /* | |
949 | * Delete the neighbor on the right and absorb it into the new key | |
950 | * (cases 3 and 4). | |
951 | */ | |
952 | if (found_start == end) { | |
953 | ret = btrfs_del_item(trans, root, path); | |
954 | if (ret) | |
955 | goto out; | |
956 | new_key.offset += key.offset; | |
957 | new_extents--; | |
958 | } | |
959 | btrfs_release_path(path); | |
960 | ||
961 | insert: | |
962 | /* Insert the new key (cases 1-4). */ | |
963 | ret = btrfs_insert_empty_item(trans, root, path, &new_key, 0); | |
964 | if (ret) | |
965 | goto out; | |
966 | ||
967 | btrfs_release_path(path); | |
968 | ret = update_free_space_extent_count(trans, fs_info, block_group, path, | |
969 | new_extents); | |
970 | ||
971 | out: | |
972 | return ret; | |
973 | } | |
974 | ||
975 | int __add_to_free_space_tree(struct btrfs_trans_handle *trans, | |
976 | struct btrfs_fs_info *fs_info, | |
977 | struct btrfs_block_group_cache *block_group, | |
978 | struct btrfs_path *path, u64 start, u64 size) | |
979 | { | |
980 | struct btrfs_free_space_info *info; | |
981 | u32 flags; | |
982 | int ret; | |
983 | ||
984 | if (block_group->needs_free_space) { | |
985 | ret = __add_block_group_free_space(trans, fs_info, block_group, | |
986 | path); | |
987 | if (ret) | |
988 | return ret; | |
989 | } | |
990 | ||
991 | info = search_free_space_info(NULL, fs_info, block_group, path, 0); | |
992 | if (IS_ERR(info)) | |
993 | return PTR_ERR(info); | |
994 | flags = btrfs_free_space_flags(path->nodes[0], info); | |
995 | btrfs_release_path(path); | |
996 | ||
997 | if (flags & BTRFS_FREE_SPACE_USING_BITMAPS) { | |
998 | return modify_free_space_bitmap(trans, fs_info, block_group, | |
999 | path, start, size, 0); | |
1000 | } else { | |
1001 | return add_free_space_extent(trans, fs_info, block_group, path, | |
1002 | start, size); | |
1003 | } | |
1004 | } | |
1005 | ||
1006 | int add_to_free_space_tree(struct btrfs_trans_handle *trans, | |
1007 | struct btrfs_fs_info *fs_info, | |
1008 | u64 start, u64 size) | |
1009 | { | |
1010 | struct btrfs_block_group_cache *block_group; | |
1011 | struct btrfs_path *path; | |
1012 | int ret; | |
1013 | ||
1014 | if (!btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) | |
1015 | return 0; | |
1016 | ||
1017 | path = btrfs_alloc_path(); | |
1018 | if (!path) { | |
1019 | ret = -ENOMEM; | |
1020 | goto out; | |
1021 | } | |
1022 | ||
1023 | block_group = btrfs_lookup_block_group(fs_info, start); | |
1024 | if (!block_group) { | |
1025 | ASSERT(0); | |
1026 | ret = -ENOENT; | |
1027 | goto out; | |
1028 | } | |
1029 | ||
1030 | mutex_lock(&block_group->free_space_lock); | |
1031 | ret = __add_to_free_space_tree(trans, fs_info, block_group, path, start, | |
1032 | size); | |
1033 | mutex_unlock(&block_group->free_space_lock); | |
1034 | ||
1035 | btrfs_put_block_group(block_group); | |
1036 | out: | |
1037 | btrfs_free_path(path); | |
1038 | if (ret) | |
66642832 | 1039 | btrfs_abort_transaction(trans, ret); |
a5ed9182 OS |
1040 | return ret; |
1041 | } | |
1042 | ||
1043 | /* | |
1044 | * Populate the free space tree by walking the extent tree. Operations on the | |
1045 | * extent tree that happen as a result of writes to the free space tree will go | |
1046 | * through the normal add/remove hooks. | |
1047 | */ | |
1048 | static int populate_free_space_tree(struct btrfs_trans_handle *trans, | |
1049 | struct btrfs_fs_info *fs_info, | |
1050 | struct btrfs_block_group_cache *block_group) | |
1051 | { | |
1052 | struct btrfs_root *extent_root = fs_info->extent_root; | |
1053 | struct btrfs_path *path, *path2; | |
1054 | struct btrfs_key key; | |
1055 | u64 start, end; | |
1056 | int ret; | |
1057 | ||
1058 | path = btrfs_alloc_path(); | |
1059 | if (!path) | |
1060 | return -ENOMEM; | |
019599ad | 1061 | path->reada = READA_FORWARD; |
a5ed9182 OS |
1062 | |
1063 | path2 = btrfs_alloc_path(); | |
1064 | if (!path2) { | |
1065 | btrfs_free_path(path); | |
1066 | return -ENOMEM; | |
1067 | } | |
1068 | ||
1069 | ret = add_new_free_space_info(trans, fs_info, block_group, path2); | |
1070 | if (ret) | |
1071 | goto out; | |
1072 | ||
511711af CM |
1073 | mutex_lock(&block_group->free_space_lock); |
1074 | ||
a5ed9182 OS |
1075 | /* |
1076 | * Iterate through all of the extent and metadata items in this block | |
1077 | * group, adding the free space between them and the free space at the | |
1078 | * end. Note that EXTENT_ITEM and METADATA_ITEM are less than | |
1079 | * BLOCK_GROUP_ITEM, so an extent may precede the block group that it's | |
1080 | * contained in. | |
1081 | */ | |
1082 | key.objectid = block_group->key.objectid; | |
1083 | key.type = BTRFS_EXTENT_ITEM_KEY; | |
1084 | key.offset = 0; | |
1085 | ||
1086 | ret = btrfs_search_slot_for_read(extent_root, &key, path, 1, 0); | |
1087 | if (ret < 0) | |
511711af | 1088 | goto out_locked; |
a5ed9182 OS |
1089 | ASSERT(ret == 0); |
1090 | ||
1091 | start = block_group->key.objectid; | |
1092 | end = block_group->key.objectid + block_group->key.offset; | |
1093 | while (1) { | |
1094 | btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); | |
1095 | ||
1096 | if (key.type == BTRFS_EXTENT_ITEM_KEY || | |
1097 | key.type == BTRFS_METADATA_ITEM_KEY) { | |
1098 | if (key.objectid >= end) | |
1099 | break; | |
1100 | ||
1101 | if (start < key.objectid) { | |
1102 | ret = __add_to_free_space_tree(trans, fs_info, | |
1103 | block_group, | |
1104 | path2, start, | |
1105 | key.objectid - | |
1106 | start); | |
1107 | if (ret) | |
511711af | 1108 | goto out_locked; |
a5ed9182 OS |
1109 | } |
1110 | start = key.objectid; | |
1111 | if (key.type == BTRFS_METADATA_ITEM_KEY) | |
da17066c | 1112 | start += fs_info->nodesize; |
a5ed9182 OS |
1113 | else |
1114 | start += key.offset; | |
1115 | } else if (key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) { | |
1116 | if (key.objectid != block_group->key.objectid) | |
1117 | break; | |
1118 | } | |
1119 | ||
1120 | ret = btrfs_next_item(extent_root, path); | |
1121 | if (ret < 0) | |
511711af | 1122 | goto out_locked; |
a5ed9182 OS |
1123 | if (ret) |
1124 | break; | |
1125 | } | |
1126 | if (start < end) { | |
1127 | ret = __add_to_free_space_tree(trans, fs_info, block_group, | |
1128 | path2, start, end - start); | |
1129 | if (ret) | |
511711af | 1130 | goto out_locked; |
a5ed9182 OS |
1131 | } |
1132 | ||
1133 | ret = 0; | |
511711af CM |
1134 | out_locked: |
1135 | mutex_unlock(&block_group->free_space_lock); | |
a5ed9182 OS |
1136 | out: |
1137 | btrfs_free_path(path2); | |
1138 | btrfs_free_path(path); | |
1139 | return ret; | |
1140 | } | |
1141 | ||
1142 | int btrfs_create_free_space_tree(struct btrfs_fs_info *fs_info) | |
1143 | { | |
1144 | struct btrfs_trans_handle *trans; | |
1145 | struct btrfs_root *tree_root = fs_info->tree_root; | |
1146 | struct btrfs_root *free_space_root; | |
1147 | struct btrfs_block_group_cache *block_group; | |
1148 | struct rb_node *node; | |
1149 | int ret; | |
1150 | ||
1151 | trans = btrfs_start_transaction(tree_root, 0); | |
1152 | if (IS_ERR(trans)) | |
1153 | return PTR_ERR(trans); | |
1154 | ||
afcdd129 | 1155 | set_bit(BTRFS_FS_CREATING_FREE_SPACE_TREE, &fs_info->flags); |
a5ed9182 OS |
1156 | free_space_root = btrfs_create_tree(trans, fs_info, |
1157 | BTRFS_FREE_SPACE_TREE_OBJECTID); | |
1158 | if (IS_ERR(free_space_root)) { | |
1159 | ret = PTR_ERR(free_space_root); | |
1160 | goto abort; | |
1161 | } | |
1162 | fs_info->free_space_root = free_space_root; | |
1163 | ||
1164 | node = rb_first(&fs_info->block_group_cache_tree); | |
1165 | while (node) { | |
1166 | block_group = rb_entry(node, struct btrfs_block_group_cache, | |
1167 | cache_node); | |
1168 | ret = populate_free_space_tree(trans, fs_info, block_group); | |
1169 | if (ret) | |
1170 | goto abort; | |
1171 | node = rb_next(node); | |
1172 | } | |
1173 | ||
1174 | btrfs_set_fs_compat_ro(fs_info, FREE_SPACE_TREE); | |
6675df31 | 1175 | btrfs_set_fs_compat_ro(fs_info, FREE_SPACE_TREE_VALID); |
afcdd129 | 1176 | clear_bit(BTRFS_FS_CREATING_FREE_SPACE_TREE, &fs_info->flags); |
a5ed9182 | 1177 | |
0bef7109 | 1178 | return btrfs_commit_transaction(trans); |
a5ed9182 OS |
1179 | |
1180 | abort: | |
afcdd129 | 1181 | clear_bit(BTRFS_FS_CREATING_FREE_SPACE_TREE, &fs_info->flags); |
66642832 | 1182 | btrfs_abort_transaction(trans, ret); |
3a45bb20 | 1183 | btrfs_end_transaction(trans); |
a5ed9182 OS |
1184 | return ret; |
1185 | } | |
1186 | ||
1187 | static int clear_free_space_tree(struct btrfs_trans_handle *trans, | |
1188 | struct btrfs_root *root) | |
1189 | { | |
1190 | struct btrfs_path *path; | |
1191 | struct btrfs_key key; | |
1192 | int nr; | |
1193 | int ret; | |
1194 | ||
1195 | path = btrfs_alloc_path(); | |
1196 | if (!path) | |
1197 | return -ENOMEM; | |
1198 | ||
1199 | path->leave_spinning = 1; | |
1200 | ||
1201 | key.objectid = 0; | |
1202 | key.type = 0; | |
1203 | key.offset = 0; | |
1204 | ||
1205 | while (1) { | |
1206 | ret = btrfs_search_slot(trans, root, &key, path, -1, 1); | |
1207 | if (ret < 0) | |
1208 | goto out; | |
1209 | ||
1210 | nr = btrfs_header_nritems(path->nodes[0]); | |
1211 | if (!nr) | |
1212 | break; | |
1213 | ||
1214 | path->slots[0] = 0; | |
1215 | ret = btrfs_del_items(trans, root, path, 0, nr); | |
1216 | if (ret) | |
1217 | goto out; | |
1218 | ||
1219 | btrfs_release_path(path); | |
1220 | } | |
1221 | ||
1222 | ret = 0; | |
1223 | out: | |
1224 | btrfs_free_path(path); | |
1225 | return ret; | |
1226 | } | |
1227 | ||
1228 | int btrfs_clear_free_space_tree(struct btrfs_fs_info *fs_info) | |
1229 | { | |
1230 | struct btrfs_trans_handle *trans; | |
1231 | struct btrfs_root *tree_root = fs_info->tree_root; | |
1232 | struct btrfs_root *free_space_root = fs_info->free_space_root; | |
1233 | int ret; | |
1234 | ||
1235 | trans = btrfs_start_transaction(tree_root, 0); | |
1236 | if (IS_ERR(trans)) | |
1237 | return PTR_ERR(trans); | |
1238 | ||
1239 | btrfs_clear_fs_compat_ro(fs_info, FREE_SPACE_TREE); | |
6675df31 | 1240 | btrfs_clear_fs_compat_ro(fs_info, FREE_SPACE_TREE_VALID); |
a5ed9182 OS |
1241 | fs_info->free_space_root = NULL; |
1242 | ||
1243 | ret = clear_free_space_tree(trans, free_space_root); | |
1244 | if (ret) | |
1245 | goto abort; | |
1246 | ||
1cd5447e | 1247 | ret = btrfs_del_root(trans, fs_info, &free_space_root->root_key); |
a5ed9182 OS |
1248 | if (ret) |
1249 | goto abort; | |
1250 | ||
1251 | list_del(&free_space_root->dirty_list); | |
1252 | ||
1253 | btrfs_tree_lock(free_space_root->node); | |
7c302b49 | 1254 | clean_tree_block(fs_info, free_space_root->node); |
a5ed9182 OS |
1255 | btrfs_tree_unlock(free_space_root->node); |
1256 | btrfs_free_tree_block(trans, free_space_root, free_space_root->node, | |
1257 | 0, 1); | |
1258 | ||
1259 | free_extent_buffer(free_space_root->node); | |
1260 | free_extent_buffer(free_space_root->commit_root); | |
1261 | kfree(free_space_root); | |
1262 | ||
0bef7109 | 1263 | return btrfs_commit_transaction(trans); |
a5ed9182 OS |
1264 | |
1265 | abort: | |
66642832 | 1266 | btrfs_abort_transaction(trans, ret); |
3a45bb20 | 1267 | btrfs_end_transaction(trans); |
a5ed9182 OS |
1268 | return ret; |
1269 | } | |
1270 | ||
1271 | static int __add_block_group_free_space(struct btrfs_trans_handle *trans, | |
1272 | struct btrfs_fs_info *fs_info, | |
1273 | struct btrfs_block_group_cache *block_group, | |
1274 | struct btrfs_path *path) | |
1275 | { | |
a5ed9182 OS |
1276 | int ret; |
1277 | ||
a5ed9182 OS |
1278 | block_group->needs_free_space = 0; |
1279 | ||
1280 | ret = add_new_free_space_info(trans, fs_info, block_group, path); | |
1281 | if (ret) | |
1282 | return ret; | |
1283 | ||
1284 | return __add_to_free_space_tree(trans, fs_info, block_group, path, | |
1285 | block_group->key.objectid, | |
1286 | block_group->key.offset); | |
1287 | } | |
1288 | ||
1289 | int add_block_group_free_space(struct btrfs_trans_handle *trans, | |
1290 | struct btrfs_fs_info *fs_info, | |
1291 | struct btrfs_block_group_cache *block_group) | |
1292 | { | |
1293 | struct btrfs_path *path = NULL; | |
1294 | int ret = 0; | |
1295 | ||
1296 | if (!btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) | |
1297 | return 0; | |
1298 | ||
1299 | mutex_lock(&block_group->free_space_lock); | |
1300 | if (!block_group->needs_free_space) | |
1301 | goto out; | |
1302 | ||
1303 | path = btrfs_alloc_path(); | |
1304 | if (!path) { | |
1305 | ret = -ENOMEM; | |
1306 | goto out; | |
1307 | } | |
1308 | ||
1309 | ret = __add_block_group_free_space(trans, fs_info, block_group, path); | |
1310 | ||
1311 | out: | |
1312 | btrfs_free_path(path); | |
1313 | mutex_unlock(&block_group->free_space_lock); | |
1314 | if (ret) | |
66642832 | 1315 | btrfs_abort_transaction(trans, ret); |
a5ed9182 OS |
1316 | return ret; |
1317 | } | |
1318 | ||
1319 | int remove_block_group_free_space(struct btrfs_trans_handle *trans, | |
1320 | struct btrfs_fs_info *fs_info, | |
1321 | struct btrfs_block_group_cache *block_group) | |
1322 | { | |
1323 | struct btrfs_root *root = fs_info->free_space_root; | |
1324 | struct btrfs_path *path; | |
1325 | struct btrfs_key key, found_key; | |
1326 | struct extent_buffer *leaf; | |
1327 | u64 start, end; | |
1328 | int done = 0, nr; | |
1329 | int ret; | |
1330 | ||
1331 | if (!btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) | |
1332 | return 0; | |
1333 | ||
1334 | if (block_group->needs_free_space) { | |
1335 | /* We never added this block group to the free space tree. */ | |
1336 | return 0; | |
1337 | } | |
1338 | ||
1339 | path = btrfs_alloc_path(); | |
1340 | if (!path) { | |
1341 | ret = -ENOMEM; | |
1342 | goto out; | |
1343 | } | |
1344 | ||
1345 | start = block_group->key.objectid; | |
1346 | end = block_group->key.objectid + block_group->key.offset; | |
1347 | ||
1348 | key.objectid = end - 1; | |
1349 | key.type = (u8)-1; | |
1350 | key.offset = (u64)-1; | |
1351 | ||
1352 | while (!done) { | |
1353 | ret = btrfs_search_prev_slot(trans, root, &key, path, -1, 1); | |
1354 | if (ret) | |
1355 | goto out; | |
1356 | ||
1357 | leaf = path->nodes[0]; | |
1358 | nr = 0; | |
1359 | path->slots[0]++; | |
1360 | while (path->slots[0] > 0) { | |
1361 | btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0] - 1); | |
1362 | ||
1363 | if (found_key.type == BTRFS_FREE_SPACE_INFO_KEY) { | |
1364 | ASSERT(found_key.objectid == block_group->key.objectid); | |
1365 | ASSERT(found_key.offset == block_group->key.offset); | |
1366 | done = 1; | |
1367 | nr++; | |
1368 | path->slots[0]--; | |
1369 | break; | |
1370 | } else if (found_key.type == BTRFS_FREE_SPACE_EXTENT_KEY || | |
1371 | found_key.type == BTRFS_FREE_SPACE_BITMAP_KEY) { | |
1372 | ASSERT(found_key.objectid >= start); | |
1373 | ASSERT(found_key.objectid < end); | |
1374 | ASSERT(found_key.objectid + found_key.offset <= end); | |
1375 | nr++; | |
1376 | path->slots[0]--; | |
1377 | } else { | |
1378 | ASSERT(0); | |
1379 | } | |
1380 | } | |
1381 | ||
1382 | ret = btrfs_del_items(trans, root, path, path->slots[0], nr); | |
1383 | if (ret) | |
1384 | goto out; | |
1385 | btrfs_release_path(path); | |
1386 | } | |
1387 | ||
1388 | ret = 0; | |
1389 | out: | |
1390 | btrfs_free_path(path); | |
1391 | if (ret) | |
66642832 | 1392 | btrfs_abort_transaction(trans, ret); |
a5ed9182 OS |
1393 | return ret; |
1394 | } | |
1395 | ||
1396 | static int load_free_space_bitmaps(struct btrfs_caching_control *caching_ctl, | |
1397 | struct btrfs_path *path, | |
1398 | u32 expected_extent_count) | |
1399 | { | |
1400 | struct btrfs_block_group_cache *block_group; | |
1401 | struct btrfs_fs_info *fs_info; | |
1402 | struct btrfs_root *root; | |
1403 | struct btrfs_key key; | |
1404 | int prev_bit = 0, bit; | |
1405 | /* Initialize to silence GCC. */ | |
1406 | u64 extent_start = 0; | |
1407 | u64 end, offset; | |
1408 | u64 total_found = 0; | |
1409 | u32 extent_count = 0; | |
1410 | int ret; | |
1411 | ||
1412 | block_group = caching_ctl->block_group; | |
1413 | fs_info = block_group->fs_info; | |
1414 | root = fs_info->free_space_root; | |
1415 | ||
1416 | end = block_group->key.objectid + block_group->key.offset; | |
1417 | ||
1418 | while (1) { | |
1419 | ret = btrfs_next_item(root, path); | |
1420 | if (ret < 0) | |
1421 | goto out; | |
1422 | if (ret) | |
1423 | break; | |
1424 | ||
1425 | btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); | |
1426 | ||
1427 | if (key.type == BTRFS_FREE_SPACE_INFO_KEY) | |
1428 | break; | |
1429 | ||
1430 | ASSERT(key.type == BTRFS_FREE_SPACE_BITMAP_KEY); | |
1431 | ASSERT(key.objectid < end && key.objectid + key.offset <= end); | |
1432 | ||
1433 | caching_ctl->progress = key.objectid; | |
1434 | ||
1435 | offset = key.objectid; | |
1436 | while (offset < key.objectid + key.offset) { | |
1437 | bit = free_space_test_bit(block_group, path, offset); | |
1438 | if (prev_bit == 0 && bit == 1) { | |
1439 | extent_start = offset; | |
1440 | } else if (prev_bit == 1 && bit == 0) { | |
1441 | total_found += add_new_free_space(block_group, | |
1442 | fs_info, | |
1443 | extent_start, | |
1444 | offset); | |
1445 | if (total_found > CACHING_CTL_WAKE_UP) { | |
1446 | total_found = 0; | |
1447 | wake_up(&caching_ctl->wait); | |
1448 | } | |
1449 | extent_count++; | |
1450 | } | |
1451 | prev_bit = bit; | |
0b246afa | 1452 | offset += fs_info->sectorsize; |
a5ed9182 OS |
1453 | } |
1454 | } | |
1455 | if (prev_bit == 1) { | |
1456 | total_found += add_new_free_space(block_group, fs_info, | |
1457 | extent_start, end); | |
1458 | extent_count++; | |
1459 | } | |
1460 | ||
1461 | if (extent_count != expected_extent_count) { | |
5d163e0e JM |
1462 | btrfs_err(fs_info, |
1463 | "incorrect extent count for %llu; counted %u, expected %u", | |
a5ed9182 OS |
1464 | block_group->key.objectid, extent_count, |
1465 | expected_extent_count); | |
1466 | ASSERT(0); | |
1467 | ret = -EIO; | |
1468 | goto out; | |
1469 | } | |
1470 | ||
1471 | caching_ctl->progress = (u64)-1; | |
1472 | ||
1473 | ret = 0; | |
1474 | out: | |
1475 | return ret; | |
1476 | } | |
1477 | ||
1478 | static int load_free_space_extents(struct btrfs_caching_control *caching_ctl, | |
1479 | struct btrfs_path *path, | |
1480 | u32 expected_extent_count) | |
1481 | { | |
1482 | struct btrfs_block_group_cache *block_group; | |
1483 | struct btrfs_fs_info *fs_info; | |
1484 | struct btrfs_root *root; | |
1485 | struct btrfs_key key; | |
1486 | u64 end; | |
1487 | u64 total_found = 0; | |
1488 | u32 extent_count = 0; | |
1489 | int ret; | |
1490 | ||
1491 | block_group = caching_ctl->block_group; | |
1492 | fs_info = block_group->fs_info; | |
1493 | root = fs_info->free_space_root; | |
1494 | ||
1495 | end = block_group->key.objectid + block_group->key.offset; | |
1496 | ||
1497 | while (1) { | |
1498 | ret = btrfs_next_item(root, path); | |
1499 | if (ret < 0) | |
1500 | goto out; | |
1501 | if (ret) | |
1502 | break; | |
1503 | ||
1504 | btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); | |
1505 | ||
1506 | if (key.type == BTRFS_FREE_SPACE_INFO_KEY) | |
1507 | break; | |
1508 | ||
1509 | ASSERT(key.type == BTRFS_FREE_SPACE_EXTENT_KEY); | |
1510 | ASSERT(key.objectid < end && key.objectid + key.offset <= end); | |
1511 | ||
1512 | caching_ctl->progress = key.objectid; | |
1513 | ||
1514 | total_found += add_new_free_space(block_group, fs_info, | |
1515 | key.objectid, | |
1516 | key.objectid + key.offset); | |
1517 | if (total_found > CACHING_CTL_WAKE_UP) { | |
1518 | total_found = 0; | |
1519 | wake_up(&caching_ctl->wait); | |
1520 | } | |
1521 | extent_count++; | |
1522 | } | |
1523 | ||
1524 | if (extent_count != expected_extent_count) { | |
5d163e0e JM |
1525 | btrfs_err(fs_info, |
1526 | "incorrect extent count for %llu; counted %u, expected %u", | |
a5ed9182 OS |
1527 | block_group->key.objectid, extent_count, |
1528 | expected_extent_count); | |
1529 | ASSERT(0); | |
1530 | ret = -EIO; | |
1531 | goto out; | |
1532 | } | |
1533 | ||
1534 | caching_ctl->progress = (u64)-1; | |
1535 | ||
1536 | ret = 0; | |
1537 | out: | |
1538 | return ret; | |
1539 | } | |
1540 | ||
1541 | int load_free_space_tree(struct btrfs_caching_control *caching_ctl) | |
1542 | { | |
1543 | struct btrfs_block_group_cache *block_group; | |
1544 | struct btrfs_fs_info *fs_info; | |
1545 | struct btrfs_free_space_info *info; | |
1546 | struct btrfs_path *path; | |
1547 | u32 extent_count, flags; | |
1548 | int ret; | |
1549 | ||
1550 | block_group = caching_ctl->block_group; | |
1551 | fs_info = block_group->fs_info; | |
1552 | ||
1553 | path = btrfs_alloc_path(); | |
1554 | if (!path) | |
1555 | return -ENOMEM; | |
1556 | ||
1557 | /* | |
1558 | * Just like caching_thread() doesn't want to deadlock on the extent | |
1559 | * tree, we don't want to deadlock on the free space tree. | |
1560 | */ | |
1561 | path->skip_locking = 1; | |
1562 | path->search_commit_root = 1; | |
7ce311d5 | 1563 | path->reada = READA_FORWARD; |
a5ed9182 OS |
1564 | |
1565 | info = search_free_space_info(NULL, fs_info, block_group, path, 0); | |
1566 | if (IS_ERR(info)) { | |
1567 | ret = PTR_ERR(info); | |
1568 | goto out; | |
1569 | } | |
1570 | extent_count = btrfs_free_space_extent_count(path->nodes[0], info); | |
1571 | flags = btrfs_free_space_flags(path->nodes[0], info); | |
1572 | ||
1573 | /* | |
1574 | * We left path pointing to the free space info item, so now | |
1575 | * load_free_space_foo can just iterate through the free space tree from | |
1576 | * there. | |
1577 | */ | |
1578 | if (flags & BTRFS_FREE_SPACE_USING_BITMAPS) | |
1579 | ret = load_free_space_bitmaps(caching_ctl, path, extent_count); | |
1580 | else | |
1581 | ret = load_free_space_extents(caching_ctl, path, extent_count); | |
1582 | ||
1583 | out: | |
1584 | btrfs_free_path(path); | |
1585 | return ret; | |
1586 | } |