Commit | Line | Data |
---|---|---|
0f9dd46c JB |
1 | /* |
2 | * Copyright (C) 2008 Red Hat. 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 | ||
96303081 | 19 | #include <linux/pagemap.h> |
0f9dd46c | 20 | #include <linux/sched.h> |
96303081 | 21 | #include <linux/math64.h> |
0f9dd46c | 22 | #include "ctree.h" |
fa9c0d79 CM |
23 | #include "free-space-cache.h" |
24 | #include "transaction.h" | |
25 | ||
96303081 JB |
26 | #define BITS_PER_BITMAP (PAGE_CACHE_SIZE * 8) |
27 | #define MAX_CACHE_BYTES_PER_GIG (32 * 1024) | |
0f9dd46c | 28 | |
96303081 JB |
29 | static inline unsigned long offset_to_bit(u64 bitmap_start, u64 sectorsize, |
30 | u64 offset) | |
0f9dd46c | 31 | { |
96303081 JB |
32 | BUG_ON(offset < bitmap_start); |
33 | offset -= bitmap_start; | |
34 | return (unsigned long)(div64_u64(offset, sectorsize)); | |
35 | } | |
0f9dd46c | 36 | |
96303081 JB |
37 | static inline unsigned long bytes_to_bits(u64 bytes, u64 sectorsize) |
38 | { | |
39 | return (unsigned long)(div64_u64(bytes, sectorsize)); | |
40 | } | |
0f9dd46c | 41 | |
96303081 JB |
42 | static inline u64 offset_to_bitmap(struct btrfs_block_group_cache *block_group, |
43 | u64 offset) | |
44 | { | |
45 | u64 bitmap_start; | |
46 | u64 bytes_per_bitmap; | |
0f9dd46c | 47 | |
96303081 JB |
48 | bytes_per_bitmap = BITS_PER_BITMAP * block_group->sectorsize; |
49 | bitmap_start = offset - block_group->key.objectid; | |
50 | bitmap_start = div64_u64(bitmap_start, bytes_per_bitmap); | |
51 | bitmap_start *= bytes_per_bitmap; | |
52 | bitmap_start += block_group->key.objectid; | |
0f9dd46c | 53 | |
96303081 | 54 | return bitmap_start; |
0f9dd46c JB |
55 | } |
56 | ||
96303081 JB |
57 | static int tree_insert_offset(struct rb_root *root, u64 offset, |
58 | struct rb_node *node, int bitmap) | |
0f9dd46c JB |
59 | { |
60 | struct rb_node **p = &root->rb_node; | |
61 | struct rb_node *parent = NULL; | |
62 | struct btrfs_free_space *info; | |
63 | ||
64 | while (*p) { | |
65 | parent = *p; | |
96303081 | 66 | info = rb_entry(parent, struct btrfs_free_space, offset_index); |
0f9dd46c | 67 | |
96303081 | 68 | if (offset < info->offset) { |
0f9dd46c | 69 | p = &(*p)->rb_left; |
96303081 | 70 | } else if (offset > info->offset) { |
0f9dd46c | 71 | p = &(*p)->rb_right; |
96303081 JB |
72 | } else { |
73 | /* | |
74 | * we could have a bitmap entry and an extent entry | |
75 | * share the same offset. If this is the case, we want | |
76 | * the extent entry to always be found first if we do a | |
77 | * linear search through the tree, since we want to have | |
78 | * the quickest allocation time, and allocating from an | |
79 | * extent is faster than allocating from a bitmap. So | |
80 | * if we're inserting a bitmap and we find an entry at | |
81 | * this offset, we want to go right, or after this entry | |
82 | * logically. If we are inserting an extent and we've | |
83 | * found a bitmap, we want to go left, or before | |
84 | * logically. | |
85 | */ | |
86 | if (bitmap) { | |
87 | WARN_ON(info->bitmap); | |
88 | p = &(*p)->rb_right; | |
89 | } else { | |
90 | WARN_ON(!info->bitmap); | |
91 | p = &(*p)->rb_left; | |
92 | } | |
93 | } | |
0f9dd46c JB |
94 | } |
95 | ||
96 | rb_link_node(node, parent, p); | |
97 | rb_insert_color(node, root); | |
98 | ||
99 | return 0; | |
100 | } | |
101 | ||
102 | /* | |
70cb0743 JB |
103 | * searches the tree for the given offset. |
104 | * | |
96303081 JB |
105 | * fuzzy - If this is set, then we are trying to make an allocation, and we just |
106 | * want a section that has at least bytes size and comes at or after the given | |
107 | * offset. | |
0f9dd46c | 108 | */ |
96303081 JB |
109 | static struct btrfs_free_space * |
110 | tree_search_offset(struct btrfs_block_group_cache *block_group, | |
111 | u64 offset, int bitmap_only, int fuzzy) | |
0f9dd46c | 112 | { |
96303081 JB |
113 | struct rb_node *n = block_group->free_space_offset.rb_node; |
114 | struct btrfs_free_space *entry, *prev = NULL; | |
115 | ||
116 | /* find entry that is closest to the 'offset' */ | |
117 | while (1) { | |
118 | if (!n) { | |
119 | entry = NULL; | |
120 | break; | |
121 | } | |
0f9dd46c | 122 | |
0f9dd46c | 123 | entry = rb_entry(n, struct btrfs_free_space, offset_index); |
96303081 | 124 | prev = entry; |
0f9dd46c | 125 | |
96303081 | 126 | if (offset < entry->offset) |
0f9dd46c | 127 | n = n->rb_left; |
96303081 | 128 | else if (offset > entry->offset) |
0f9dd46c | 129 | n = n->rb_right; |
96303081 | 130 | else |
0f9dd46c | 131 | break; |
0f9dd46c JB |
132 | } |
133 | ||
96303081 JB |
134 | if (bitmap_only) { |
135 | if (!entry) | |
136 | return NULL; | |
137 | if (entry->bitmap) | |
138 | return entry; | |
0f9dd46c | 139 | |
96303081 JB |
140 | /* |
141 | * bitmap entry and extent entry may share same offset, | |
142 | * in that case, bitmap entry comes after extent entry. | |
143 | */ | |
144 | n = rb_next(n); | |
145 | if (!n) | |
146 | return NULL; | |
147 | entry = rb_entry(n, struct btrfs_free_space, offset_index); | |
148 | if (entry->offset != offset) | |
149 | return NULL; | |
0f9dd46c | 150 | |
96303081 JB |
151 | WARN_ON(!entry->bitmap); |
152 | return entry; | |
153 | } else if (entry) { | |
154 | if (entry->bitmap) { | |
0f9dd46c | 155 | /* |
96303081 JB |
156 | * if previous extent entry covers the offset, |
157 | * we should return it instead of the bitmap entry | |
0f9dd46c | 158 | */ |
96303081 JB |
159 | n = &entry->offset_index; |
160 | while (1) { | |
161 | n = rb_prev(n); | |
162 | if (!n) | |
163 | break; | |
164 | prev = rb_entry(n, struct btrfs_free_space, | |
165 | offset_index); | |
166 | if (!prev->bitmap) { | |
167 | if (prev->offset + prev->bytes > offset) | |
168 | entry = prev; | |
169 | break; | |
170 | } | |
0f9dd46c | 171 | } |
96303081 JB |
172 | } |
173 | return entry; | |
174 | } | |
175 | ||
176 | if (!prev) | |
177 | return NULL; | |
178 | ||
179 | /* find last entry before the 'offset' */ | |
180 | entry = prev; | |
181 | if (entry->offset > offset) { | |
182 | n = rb_prev(&entry->offset_index); | |
183 | if (n) { | |
184 | entry = rb_entry(n, struct btrfs_free_space, | |
185 | offset_index); | |
186 | BUG_ON(entry->offset > offset); | |
0f9dd46c | 187 | } else { |
96303081 JB |
188 | if (fuzzy) |
189 | return entry; | |
190 | else | |
191 | return NULL; | |
0f9dd46c JB |
192 | } |
193 | } | |
194 | ||
96303081 JB |
195 | if (entry->bitmap) { |
196 | n = &entry->offset_index; | |
197 | while (1) { | |
198 | n = rb_prev(n); | |
199 | if (!n) | |
200 | break; | |
201 | prev = rb_entry(n, struct btrfs_free_space, | |
202 | offset_index); | |
203 | if (!prev->bitmap) { | |
204 | if (prev->offset + prev->bytes > offset) | |
205 | return prev; | |
206 | break; | |
207 | } | |
208 | } | |
209 | if (entry->offset + BITS_PER_BITMAP * | |
210 | block_group->sectorsize > offset) | |
211 | return entry; | |
212 | } else if (entry->offset + entry->bytes > offset) | |
213 | return entry; | |
214 | ||
215 | if (!fuzzy) | |
216 | return NULL; | |
217 | ||
218 | while (1) { | |
219 | if (entry->bitmap) { | |
220 | if (entry->offset + BITS_PER_BITMAP * | |
221 | block_group->sectorsize > offset) | |
222 | break; | |
223 | } else { | |
224 | if (entry->offset + entry->bytes > offset) | |
225 | break; | |
226 | } | |
227 | ||
228 | n = rb_next(&entry->offset_index); | |
229 | if (!n) | |
230 | return NULL; | |
231 | entry = rb_entry(n, struct btrfs_free_space, offset_index); | |
232 | } | |
233 | return entry; | |
0f9dd46c JB |
234 | } |
235 | ||
236 | static void unlink_free_space(struct btrfs_block_group_cache *block_group, | |
237 | struct btrfs_free_space *info) | |
238 | { | |
239 | rb_erase(&info->offset_index, &block_group->free_space_offset); | |
96303081 | 240 | block_group->free_extents--; |
817d52f8 | 241 | block_group->free_space -= info->bytes; |
0f9dd46c JB |
242 | } |
243 | ||
244 | static int link_free_space(struct btrfs_block_group_cache *block_group, | |
245 | struct btrfs_free_space *info) | |
246 | { | |
247 | int ret = 0; | |
248 | ||
96303081 | 249 | BUG_ON(!info->bitmap && !info->bytes); |
0f9dd46c | 250 | ret = tree_insert_offset(&block_group->free_space_offset, info->offset, |
96303081 | 251 | &info->offset_index, (info->bitmap != NULL)); |
0f9dd46c JB |
252 | if (ret) |
253 | return ret; | |
254 | ||
817d52f8 | 255 | block_group->free_space += info->bytes; |
96303081 JB |
256 | block_group->free_extents++; |
257 | return ret; | |
258 | } | |
259 | ||
260 | static void recalculate_thresholds(struct btrfs_block_group_cache *block_group) | |
261 | { | |
25891f79 JB |
262 | u64 max_bytes; |
263 | u64 bitmap_bytes; | |
264 | u64 extent_bytes; | |
96303081 JB |
265 | |
266 | /* | |
267 | * The goal is to keep the total amount of memory used per 1gb of space | |
268 | * at or below 32k, so we need to adjust how much memory we allow to be | |
269 | * used by extent based free space tracking | |
270 | */ | |
271 | max_bytes = MAX_CACHE_BYTES_PER_GIG * | |
272 | (div64_u64(block_group->key.offset, 1024 * 1024 * 1024)); | |
273 | ||
25891f79 JB |
274 | /* |
275 | * we want to account for 1 more bitmap than what we have so we can make | |
276 | * sure we don't go over our overall goal of MAX_CACHE_BYTES_PER_GIG as | |
277 | * we add more bitmaps. | |
278 | */ | |
279 | bitmap_bytes = (block_group->total_bitmaps + 1) * PAGE_CACHE_SIZE; | |
96303081 | 280 | |
25891f79 JB |
281 | if (bitmap_bytes >= max_bytes) { |
282 | block_group->extents_thresh = 0; | |
283 | return; | |
284 | } | |
96303081 | 285 | |
25891f79 JB |
286 | /* |
287 | * we want the extent entry threshold to always be at most 1/2 the maxw | |
288 | * bytes we can have, or whatever is less than that. | |
289 | */ | |
290 | extent_bytes = max_bytes - bitmap_bytes; | |
291 | extent_bytes = min_t(u64, extent_bytes, div64_u64(max_bytes, 2)); | |
96303081 | 292 | |
25891f79 JB |
293 | block_group->extents_thresh = |
294 | div64_u64(extent_bytes, (sizeof(struct btrfs_free_space))); | |
96303081 JB |
295 | } |
296 | ||
817d52f8 JB |
297 | static void bitmap_clear_bits(struct btrfs_block_group_cache *block_group, |
298 | struct btrfs_free_space *info, u64 offset, | |
299 | u64 bytes) | |
96303081 JB |
300 | { |
301 | unsigned long start, end; | |
302 | unsigned long i; | |
303 | ||
817d52f8 JB |
304 | start = offset_to_bit(info->offset, block_group->sectorsize, offset); |
305 | end = start + bytes_to_bits(bytes, block_group->sectorsize); | |
96303081 JB |
306 | BUG_ON(end > BITS_PER_BITMAP); |
307 | ||
308 | for (i = start; i < end; i++) | |
309 | clear_bit(i, info->bitmap); | |
310 | ||
311 | info->bytes -= bytes; | |
817d52f8 | 312 | block_group->free_space -= bytes; |
96303081 JB |
313 | } |
314 | ||
817d52f8 JB |
315 | static void bitmap_set_bits(struct btrfs_block_group_cache *block_group, |
316 | struct btrfs_free_space *info, u64 offset, | |
317 | u64 bytes) | |
96303081 JB |
318 | { |
319 | unsigned long start, end; | |
320 | unsigned long i; | |
321 | ||
817d52f8 JB |
322 | start = offset_to_bit(info->offset, block_group->sectorsize, offset); |
323 | end = start + bytes_to_bits(bytes, block_group->sectorsize); | |
96303081 JB |
324 | BUG_ON(end > BITS_PER_BITMAP); |
325 | ||
326 | for (i = start; i < end; i++) | |
327 | set_bit(i, info->bitmap); | |
328 | ||
329 | info->bytes += bytes; | |
817d52f8 | 330 | block_group->free_space += bytes; |
96303081 JB |
331 | } |
332 | ||
333 | static int search_bitmap(struct btrfs_block_group_cache *block_group, | |
334 | struct btrfs_free_space *bitmap_info, u64 *offset, | |
335 | u64 *bytes) | |
336 | { | |
337 | unsigned long found_bits = 0; | |
338 | unsigned long bits, i; | |
339 | unsigned long next_zero; | |
340 | ||
341 | i = offset_to_bit(bitmap_info->offset, block_group->sectorsize, | |
342 | max_t(u64, *offset, bitmap_info->offset)); | |
343 | bits = bytes_to_bits(*bytes, block_group->sectorsize); | |
344 | ||
345 | for (i = find_next_bit(bitmap_info->bitmap, BITS_PER_BITMAP, i); | |
346 | i < BITS_PER_BITMAP; | |
347 | i = find_next_bit(bitmap_info->bitmap, BITS_PER_BITMAP, i + 1)) { | |
348 | next_zero = find_next_zero_bit(bitmap_info->bitmap, | |
349 | BITS_PER_BITMAP, i); | |
350 | if ((next_zero - i) >= bits) { | |
351 | found_bits = next_zero - i; | |
352 | break; | |
353 | } | |
354 | i = next_zero; | |
355 | } | |
356 | ||
357 | if (found_bits) { | |
358 | *offset = (u64)(i * block_group->sectorsize) + | |
359 | bitmap_info->offset; | |
360 | *bytes = (u64)(found_bits) * block_group->sectorsize; | |
361 | return 0; | |
362 | } | |
363 | ||
364 | return -1; | |
365 | } | |
366 | ||
367 | static struct btrfs_free_space *find_free_space(struct btrfs_block_group_cache | |
368 | *block_group, u64 *offset, | |
369 | u64 *bytes, int debug) | |
370 | { | |
371 | struct btrfs_free_space *entry; | |
372 | struct rb_node *node; | |
373 | int ret; | |
374 | ||
375 | if (!block_group->free_space_offset.rb_node) | |
376 | return NULL; | |
377 | ||
378 | entry = tree_search_offset(block_group, | |
379 | offset_to_bitmap(block_group, *offset), | |
380 | 0, 1); | |
381 | if (!entry) | |
382 | return NULL; | |
383 | ||
384 | for (node = &entry->offset_index; node; node = rb_next(node)) { | |
385 | entry = rb_entry(node, struct btrfs_free_space, offset_index); | |
386 | if (entry->bytes < *bytes) | |
387 | continue; | |
388 | ||
389 | if (entry->bitmap) { | |
390 | ret = search_bitmap(block_group, entry, offset, bytes); | |
391 | if (!ret) | |
392 | return entry; | |
393 | continue; | |
394 | } | |
395 | ||
396 | *offset = entry->offset; | |
397 | *bytes = entry->bytes; | |
398 | return entry; | |
399 | } | |
400 | ||
401 | return NULL; | |
402 | } | |
403 | ||
404 | static void add_new_bitmap(struct btrfs_block_group_cache *block_group, | |
405 | struct btrfs_free_space *info, u64 offset) | |
406 | { | |
407 | u64 bytes_per_bg = BITS_PER_BITMAP * block_group->sectorsize; | |
408 | int max_bitmaps = (int)div64_u64(block_group->key.offset + | |
409 | bytes_per_bg - 1, bytes_per_bg); | |
410 | BUG_ON(block_group->total_bitmaps >= max_bitmaps); | |
411 | ||
412 | info->offset = offset_to_bitmap(block_group, offset); | |
f019f426 | 413 | info->bytes = 0; |
96303081 JB |
414 | link_free_space(block_group, info); |
415 | block_group->total_bitmaps++; | |
416 | ||
417 | recalculate_thresholds(block_group); | |
418 | } | |
419 | ||
420 | static noinline int remove_from_bitmap(struct btrfs_block_group_cache *block_group, | |
421 | struct btrfs_free_space *bitmap_info, | |
422 | u64 *offset, u64 *bytes) | |
423 | { | |
424 | u64 end; | |
6606bb97 JB |
425 | u64 search_start, search_bytes; |
426 | int ret; | |
96303081 JB |
427 | |
428 | again: | |
429 | end = bitmap_info->offset + | |
430 | (u64)(BITS_PER_BITMAP * block_group->sectorsize) - 1; | |
431 | ||
6606bb97 JB |
432 | /* |
433 | * XXX - this can go away after a few releases. | |
434 | * | |
435 | * since the only user of btrfs_remove_free_space is the tree logging | |
436 | * stuff, and the only way to test that is under crash conditions, we | |
437 | * want to have this debug stuff here just in case somethings not | |
438 | * working. Search the bitmap for the space we are trying to use to | |
439 | * make sure its actually there. If its not there then we need to stop | |
440 | * because something has gone wrong. | |
441 | */ | |
442 | search_start = *offset; | |
443 | search_bytes = *bytes; | |
444 | ret = search_bitmap(block_group, bitmap_info, &search_start, | |
445 | &search_bytes); | |
446 | BUG_ON(ret < 0 || search_start != *offset); | |
447 | ||
96303081 | 448 | if (*offset > bitmap_info->offset && *offset + *bytes > end) { |
817d52f8 JB |
449 | bitmap_clear_bits(block_group, bitmap_info, *offset, |
450 | end - *offset + 1); | |
96303081 JB |
451 | *bytes -= end - *offset + 1; |
452 | *offset = end + 1; | |
453 | } else if (*offset >= bitmap_info->offset && *offset + *bytes <= end) { | |
817d52f8 | 454 | bitmap_clear_bits(block_group, bitmap_info, *offset, *bytes); |
96303081 JB |
455 | *bytes = 0; |
456 | } | |
457 | ||
458 | if (*bytes) { | |
6606bb97 | 459 | struct rb_node *next = rb_next(&bitmap_info->offset_index); |
96303081 JB |
460 | if (!bitmap_info->bytes) { |
461 | unlink_free_space(block_group, bitmap_info); | |
462 | kfree(bitmap_info->bitmap); | |
463 | kfree(bitmap_info); | |
464 | block_group->total_bitmaps--; | |
465 | recalculate_thresholds(block_group); | |
466 | } | |
467 | ||
6606bb97 JB |
468 | /* |
469 | * no entry after this bitmap, but we still have bytes to | |
470 | * remove, so something has gone wrong. | |
471 | */ | |
472 | if (!next) | |
96303081 JB |
473 | return -EINVAL; |
474 | ||
6606bb97 JB |
475 | bitmap_info = rb_entry(next, struct btrfs_free_space, |
476 | offset_index); | |
477 | ||
478 | /* | |
479 | * if the next entry isn't a bitmap we need to return to let the | |
480 | * extent stuff do its work. | |
481 | */ | |
96303081 JB |
482 | if (!bitmap_info->bitmap) |
483 | return -EAGAIN; | |
484 | ||
6606bb97 JB |
485 | /* |
486 | * Ok the next item is a bitmap, but it may not actually hold | |
487 | * the information for the rest of this free space stuff, so | |
488 | * look for it, and if we don't find it return so we can try | |
489 | * everything over again. | |
490 | */ | |
491 | search_start = *offset; | |
492 | search_bytes = *bytes; | |
493 | ret = search_bitmap(block_group, bitmap_info, &search_start, | |
494 | &search_bytes); | |
495 | if (ret < 0 || search_start != *offset) | |
496 | return -EAGAIN; | |
497 | ||
96303081 JB |
498 | goto again; |
499 | } else if (!bitmap_info->bytes) { | |
500 | unlink_free_space(block_group, bitmap_info); | |
501 | kfree(bitmap_info->bitmap); | |
502 | kfree(bitmap_info); | |
503 | block_group->total_bitmaps--; | |
504 | recalculate_thresholds(block_group); | |
505 | } | |
506 | ||
507 | return 0; | |
508 | } | |
509 | ||
510 | static int insert_into_bitmap(struct btrfs_block_group_cache *block_group, | |
511 | struct btrfs_free_space *info) | |
512 | { | |
513 | struct btrfs_free_space *bitmap_info; | |
514 | int added = 0; | |
515 | u64 bytes, offset, end; | |
516 | int ret; | |
517 | ||
518 | /* | |
519 | * If we are below the extents threshold then we can add this as an | |
520 | * extent, and don't have to deal with the bitmap | |
521 | */ | |
522 | if (block_group->free_extents < block_group->extents_thresh && | |
523 | info->bytes > block_group->sectorsize * 4) | |
524 | return 0; | |
525 | ||
526 | /* | |
527 | * some block groups are so tiny they can't be enveloped by a bitmap, so | |
528 | * don't even bother to create a bitmap for this | |
529 | */ | |
530 | if (BITS_PER_BITMAP * block_group->sectorsize > | |
531 | block_group->key.offset) | |
532 | return 0; | |
533 | ||
534 | bytes = info->bytes; | |
535 | offset = info->offset; | |
536 | ||
537 | again: | |
538 | bitmap_info = tree_search_offset(block_group, | |
539 | offset_to_bitmap(block_group, offset), | |
540 | 1, 0); | |
541 | if (!bitmap_info) { | |
542 | BUG_ON(added); | |
543 | goto new_bitmap; | |
544 | } | |
545 | ||
546 | end = bitmap_info->offset + | |
547 | (u64)(BITS_PER_BITMAP * block_group->sectorsize); | |
548 | ||
549 | if (offset >= bitmap_info->offset && offset + bytes > end) { | |
817d52f8 JB |
550 | bitmap_set_bits(block_group, bitmap_info, offset, |
551 | end - offset); | |
96303081 JB |
552 | bytes -= end - offset; |
553 | offset = end; | |
554 | added = 0; | |
555 | } else if (offset >= bitmap_info->offset && offset + bytes <= end) { | |
817d52f8 | 556 | bitmap_set_bits(block_group, bitmap_info, offset, bytes); |
96303081 JB |
557 | bytes = 0; |
558 | } else { | |
559 | BUG(); | |
560 | } | |
561 | ||
562 | if (!bytes) { | |
563 | ret = 1; | |
564 | goto out; | |
565 | } else | |
566 | goto again; | |
567 | ||
568 | new_bitmap: | |
569 | if (info && info->bitmap) { | |
570 | add_new_bitmap(block_group, info, offset); | |
571 | added = 1; | |
572 | info = NULL; | |
573 | goto again; | |
574 | } else { | |
575 | spin_unlock(&block_group->tree_lock); | |
576 | ||
577 | /* no pre-allocated info, allocate a new one */ | |
578 | if (!info) { | |
579 | info = kzalloc(sizeof(struct btrfs_free_space), | |
580 | GFP_NOFS); | |
581 | if (!info) { | |
582 | spin_lock(&block_group->tree_lock); | |
583 | ret = -ENOMEM; | |
584 | goto out; | |
585 | } | |
586 | } | |
587 | ||
588 | /* allocate the bitmap */ | |
589 | info->bitmap = kzalloc(PAGE_CACHE_SIZE, GFP_NOFS); | |
590 | spin_lock(&block_group->tree_lock); | |
591 | if (!info->bitmap) { | |
592 | ret = -ENOMEM; | |
593 | goto out; | |
594 | } | |
595 | goto again; | |
596 | } | |
597 | ||
598 | out: | |
599 | if (info) { | |
600 | if (info->bitmap) | |
601 | kfree(info->bitmap); | |
602 | kfree(info); | |
603 | } | |
0f9dd46c JB |
604 | |
605 | return ret; | |
606 | } | |
607 | ||
6226cb0a JB |
608 | int btrfs_add_free_space(struct btrfs_block_group_cache *block_group, |
609 | u64 offset, u64 bytes) | |
0f9dd46c | 610 | { |
96303081 JB |
611 | struct btrfs_free_space *right_info = NULL; |
612 | struct btrfs_free_space *left_info = NULL; | |
0f9dd46c | 613 | struct btrfs_free_space *info = NULL; |
0f9dd46c JB |
614 | int ret = 0; |
615 | ||
6226cb0a JB |
616 | info = kzalloc(sizeof(struct btrfs_free_space), GFP_NOFS); |
617 | if (!info) | |
618 | return -ENOMEM; | |
619 | ||
620 | info->offset = offset; | |
621 | info->bytes = bytes; | |
622 | ||
623 | spin_lock(&block_group->tree_lock); | |
624 | ||
0f9dd46c JB |
625 | /* |
626 | * first we want to see if there is free space adjacent to the range we | |
627 | * are adding, if there is remove that struct and add a new one to | |
628 | * cover the entire range | |
629 | */ | |
96303081 JB |
630 | right_info = tree_search_offset(block_group, offset + bytes, 0, 0); |
631 | if (right_info && rb_prev(&right_info->offset_index)) | |
632 | left_info = rb_entry(rb_prev(&right_info->offset_index), | |
633 | struct btrfs_free_space, offset_index); | |
634 | else | |
635 | left_info = tree_search_offset(block_group, offset - 1, 0, 0); | |
0f9dd46c | 636 | |
96303081 JB |
637 | /* |
638 | * If there was no extent directly to the left or right of this new | |
639 | * extent then we know we're going to have to allocate a new extent, so | |
640 | * before we do that see if we need to drop this into a bitmap | |
641 | */ | |
642 | if ((!left_info || left_info->bitmap) && | |
643 | (!right_info || right_info->bitmap)) { | |
644 | ret = insert_into_bitmap(block_group, info); | |
645 | ||
646 | if (ret < 0) { | |
647 | goto out; | |
648 | } else if (ret) { | |
649 | ret = 0; | |
650 | goto out; | |
651 | } | |
652 | } | |
653 | ||
654 | if (right_info && !right_info->bitmap) { | |
0f9dd46c | 655 | unlink_free_space(block_group, right_info); |
6226cb0a JB |
656 | info->bytes += right_info->bytes; |
657 | kfree(right_info); | |
0f9dd46c JB |
658 | } |
659 | ||
96303081 JB |
660 | if (left_info && !left_info->bitmap && |
661 | left_info->offset + left_info->bytes == offset) { | |
0f9dd46c | 662 | unlink_free_space(block_group, left_info); |
6226cb0a JB |
663 | info->offset = left_info->offset; |
664 | info->bytes += left_info->bytes; | |
665 | kfree(left_info); | |
0f9dd46c JB |
666 | } |
667 | ||
0f9dd46c JB |
668 | ret = link_free_space(block_group, info); |
669 | if (ret) | |
670 | kfree(info); | |
96303081 | 671 | out: |
6226cb0a JB |
672 | spin_unlock(&block_group->tree_lock); |
673 | ||
0f9dd46c | 674 | if (ret) { |
96303081 | 675 | printk(KERN_CRIT "btrfs: unable to add free space :%d\n", ret); |
c293498b | 676 | BUG_ON(ret == -EEXIST); |
0f9dd46c JB |
677 | } |
678 | ||
0f9dd46c JB |
679 | return ret; |
680 | } | |
681 | ||
6226cb0a JB |
682 | int btrfs_remove_free_space(struct btrfs_block_group_cache *block_group, |
683 | u64 offset, u64 bytes) | |
0f9dd46c JB |
684 | { |
685 | struct btrfs_free_space *info; | |
96303081 | 686 | struct btrfs_free_space *next_info = NULL; |
0f9dd46c JB |
687 | int ret = 0; |
688 | ||
6226cb0a JB |
689 | spin_lock(&block_group->tree_lock); |
690 | ||
96303081 JB |
691 | again: |
692 | info = tree_search_offset(block_group, offset, 0, 0); | |
693 | if (!info) { | |
6606bb97 JB |
694 | /* |
695 | * oops didn't find an extent that matched the space we wanted | |
696 | * to remove, look for a bitmap instead | |
697 | */ | |
698 | info = tree_search_offset(block_group, | |
699 | offset_to_bitmap(block_group, offset), | |
700 | 1, 0); | |
701 | if (!info) { | |
702 | WARN_ON(1); | |
703 | goto out_lock; | |
704 | } | |
96303081 JB |
705 | } |
706 | ||
707 | if (info->bytes < bytes && rb_next(&info->offset_index)) { | |
708 | u64 end; | |
709 | next_info = rb_entry(rb_next(&info->offset_index), | |
710 | struct btrfs_free_space, | |
711 | offset_index); | |
712 | ||
713 | if (next_info->bitmap) | |
714 | end = next_info->offset + BITS_PER_BITMAP * | |
715 | block_group->sectorsize - 1; | |
716 | else | |
717 | end = next_info->offset + next_info->bytes; | |
718 | ||
719 | if (next_info->bytes < bytes || | |
720 | next_info->offset > offset || offset > end) { | |
721 | printk(KERN_CRIT "Found free space at %llu, size %llu," | |
722 | " trying to use %llu\n", | |
723 | (unsigned long long)info->offset, | |
724 | (unsigned long long)info->bytes, | |
725 | (unsigned long long)bytes); | |
0f9dd46c JB |
726 | WARN_ON(1); |
727 | ret = -EINVAL; | |
96303081 | 728 | goto out_lock; |
0f9dd46c | 729 | } |
0f9dd46c | 730 | |
96303081 JB |
731 | info = next_info; |
732 | } | |
733 | ||
734 | if (info->bytes == bytes) { | |
735 | unlink_free_space(block_group, info); | |
736 | if (info->bitmap) { | |
737 | kfree(info->bitmap); | |
738 | block_group->total_bitmaps--; | |
0f9dd46c | 739 | } |
96303081 JB |
740 | kfree(info); |
741 | goto out_lock; | |
742 | } | |
0f9dd46c | 743 | |
96303081 JB |
744 | if (!info->bitmap && info->offset == offset) { |
745 | unlink_free_space(block_group, info); | |
0f9dd46c JB |
746 | info->offset += bytes; |
747 | info->bytes -= bytes; | |
96303081 JB |
748 | link_free_space(block_group, info); |
749 | goto out_lock; | |
750 | } | |
0f9dd46c | 751 | |
96303081 JB |
752 | if (!info->bitmap && info->offset <= offset && |
753 | info->offset + info->bytes >= offset + bytes) { | |
9b49c9b9 CM |
754 | u64 old_start = info->offset; |
755 | /* | |
756 | * we're freeing space in the middle of the info, | |
757 | * this can happen during tree log replay | |
758 | * | |
759 | * first unlink the old info and then | |
760 | * insert it again after the hole we're creating | |
761 | */ | |
762 | unlink_free_space(block_group, info); | |
763 | if (offset + bytes < info->offset + info->bytes) { | |
764 | u64 old_end = info->offset + info->bytes; | |
765 | ||
766 | info->offset = offset + bytes; | |
767 | info->bytes = old_end - info->offset; | |
768 | ret = link_free_space(block_group, info); | |
96303081 JB |
769 | WARN_ON(ret); |
770 | if (ret) | |
771 | goto out_lock; | |
9b49c9b9 CM |
772 | } else { |
773 | /* the hole we're creating ends at the end | |
774 | * of the info struct, just free the info | |
775 | */ | |
776 | kfree(info); | |
777 | } | |
6226cb0a | 778 | spin_unlock(&block_group->tree_lock); |
96303081 JB |
779 | |
780 | /* step two, insert a new info struct to cover | |
781 | * anything before the hole | |
9b49c9b9 | 782 | */ |
6226cb0a JB |
783 | ret = btrfs_add_free_space(block_group, old_start, |
784 | offset - old_start); | |
96303081 JB |
785 | WARN_ON(ret); |
786 | goto out; | |
0f9dd46c | 787 | } |
96303081 JB |
788 | |
789 | ret = remove_from_bitmap(block_group, info, &offset, &bytes); | |
790 | if (ret == -EAGAIN) | |
791 | goto again; | |
792 | BUG_ON(ret); | |
793 | out_lock: | |
794 | spin_unlock(&block_group->tree_lock); | |
0f9dd46c | 795 | out: |
25179201 JB |
796 | return ret; |
797 | } | |
798 | ||
0f9dd46c JB |
799 | void btrfs_dump_free_space(struct btrfs_block_group_cache *block_group, |
800 | u64 bytes) | |
801 | { | |
802 | struct btrfs_free_space *info; | |
803 | struct rb_node *n; | |
804 | int count = 0; | |
805 | ||
806 | for (n = rb_first(&block_group->free_space_offset); n; n = rb_next(n)) { | |
807 | info = rb_entry(n, struct btrfs_free_space, offset_index); | |
808 | if (info->bytes >= bytes) | |
809 | count++; | |
96303081 | 810 | printk(KERN_CRIT "entry offset %llu, bytes %llu, bitmap %s\n", |
21380931 | 811 | (unsigned long long)info->offset, |
96303081 JB |
812 | (unsigned long long)info->bytes, |
813 | (info->bitmap) ? "yes" : "no"); | |
0f9dd46c | 814 | } |
96303081 JB |
815 | printk(KERN_INFO "block group has cluster?: %s\n", |
816 | list_empty(&block_group->cluster_list) ? "no" : "yes"); | |
0f9dd46c JB |
817 | printk(KERN_INFO "%d blocks of free space at or bigger than bytes is" |
818 | "\n", count); | |
819 | } | |
820 | ||
821 | u64 btrfs_block_group_free_space(struct btrfs_block_group_cache *block_group) | |
822 | { | |
823 | struct btrfs_free_space *info; | |
824 | struct rb_node *n; | |
825 | u64 ret = 0; | |
826 | ||
827 | for (n = rb_first(&block_group->free_space_offset); n; | |
828 | n = rb_next(n)) { | |
829 | info = rb_entry(n, struct btrfs_free_space, offset_index); | |
830 | ret += info->bytes; | |
831 | } | |
832 | ||
833 | return ret; | |
834 | } | |
835 | ||
fa9c0d79 CM |
836 | /* |
837 | * for a given cluster, put all of its extents back into the free | |
838 | * space cache. If the block group passed doesn't match the block group | |
839 | * pointed to by the cluster, someone else raced in and freed the | |
840 | * cluster already. In that case, we just return without changing anything | |
841 | */ | |
842 | static int | |
843 | __btrfs_return_cluster_to_free_space( | |
844 | struct btrfs_block_group_cache *block_group, | |
845 | struct btrfs_free_cluster *cluster) | |
846 | { | |
847 | struct btrfs_free_space *entry; | |
848 | struct rb_node *node; | |
96303081 | 849 | bool bitmap; |
fa9c0d79 CM |
850 | |
851 | spin_lock(&cluster->lock); | |
852 | if (cluster->block_group != block_group) | |
853 | goto out; | |
854 | ||
96303081 JB |
855 | bitmap = cluster->points_to_bitmap; |
856 | cluster->block_group = NULL; | |
fa9c0d79 | 857 | cluster->window_start = 0; |
96303081 JB |
858 | list_del_init(&cluster->block_group_list); |
859 | cluster->points_to_bitmap = false; | |
860 | ||
861 | if (bitmap) | |
862 | goto out; | |
863 | ||
fa9c0d79 | 864 | node = rb_first(&cluster->root); |
96303081 | 865 | while (node) { |
fa9c0d79 CM |
866 | entry = rb_entry(node, struct btrfs_free_space, offset_index); |
867 | node = rb_next(&entry->offset_index); | |
868 | rb_erase(&entry->offset_index, &cluster->root); | |
96303081 JB |
869 | BUG_ON(entry->bitmap); |
870 | tree_insert_offset(&block_group->free_space_offset, | |
871 | entry->offset, &entry->offset_index, 0); | |
fa9c0d79 | 872 | } |
fa9c0d79 | 873 | cluster->root.rb_node = NULL; |
96303081 | 874 | |
fa9c0d79 CM |
875 | out: |
876 | spin_unlock(&cluster->lock); | |
96303081 | 877 | btrfs_put_block_group(block_group); |
fa9c0d79 CM |
878 | return 0; |
879 | } | |
880 | ||
0f9dd46c JB |
881 | void btrfs_remove_free_space_cache(struct btrfs_block_group_cache *block_group) |
882 | { | |
883 | struct btrfs_free_space *info; | |
884 | struct rb_node *node; | |
fa9c0d79 | 885 | struct btrfs_free_cluster *cluster; |
96303081 | 886 | struct list_head *head; |
0f9dd46c | 887 | |
6226cb0a | 888 | spin_lock(&block_group->tree_lock); |
96303081 JB |
889 | while ((head = block_group->cluster_list.next) != |
890 | &block_group->cluster_list) { | |
891 | cluster = list_entry(head, struct btrfs_free_cluster, | |
892 | block_group_list); | |
fa9c0d79 CM |
893 | |
894 | WARN_ON(cluster->block_group != block_group); | |
895 | __btrfs_return_cluster_to_free_space(block_group, cluster); | |
96303081 JB |
896 | if (need_resched()) { |
897 | spin_unlock(&block_group->tree_lock); | |
898 | cond_resched(); | |
899 | spin_lock(&block_group->tree_lock); | |
900 | } | |
fa9c0d79 CM |
901 | } |
902 | ||
96303081 JB |
903 | while ((node = rb_last(&block_group->free_space_offset)) != NULL) { |
904 | info = rb_entry(node, struct btrfs_free_space, offset_index); | |
0f9dd46c | 905 | unlink_free_space(block_group, info); |
96303081 JB |
906 | if (info->bitmap) |
907 | kfree(info->bitmap); | |
0f9dd46c JB |
908 | kfree(info); |
909 | if (need_resched()) { | |
6226cb0a | 910 | spin_unlock(&block_group->tree_lock); |
0f9dd46c | 911 | cond_resched(); |
6226cb0a | 912 | spin_lock(&block_group->tree_lock); |
0f9dd46c JB |
913 | } |
914 | } | |
96303081 | 915 | |
6226cb0a | 916 | spin_unlock(&block_group->tree_lock); |
0f9dd46c JB |
917 | } |
918 | ||
6226cb0a JB |
919 | u64 btrfs_find_space_for_alloc(struct btrfs_block_group_cache *block_group, |
920 | u64 offset, u64 bytes, u64 empty_size) | |
0f9dd46c | 921 | { |
6226cb0a | 922 | struct btrfs_free_space *entry = NULL; |
96303081 | 923 | u64 bytes_search = bytes + empty_size; |
6226cb0a | 924 | u64 ret = 0; |
0f9dd46c | 925 | |
6226cb0a | 926 | spin_lock(&block_group->tree_lock); |
96303081 | 927 | entry = find_free_space(block_group, &offset, &bytes_search, 0); |
6226cb0a | 928 | if (!entry) |
96303081 JB |
929 | goto out; |
930 | ||
931 | ret = offset; | |
932 | if (entry->bitmap) { | |
817d52f8 | 933 | bitmap_clear_bits(block_group, entry, offset, bytes); |
96303081 JB |
934 | if (!entry->bytes) { |
935 | unlink_free_space(block_group, entry); | |
936 | kfree(entry->bitmap); | |
937 | kfree(entry); | |
938 | block_group->total_bitmaps--; | |
939 | recalculate_thresholds(block_group); | |
940 | } | |
941 | } else { | |
6226cb0a | 942 | unlink_free_space(block_group, entry); |
6226cb0a JB |
943 | entry->offset += bytes; |
944 | entry->bytes -= bytes; | |
6226cb0a JB |
945 | if (!entry->bytes) |
946 | kfree(entry); | |
947 | else | |
948 | link_free_space(block_group, entry); | |
949 | } | |
0f9dd46c | 950 | |
96303081 JB |
951 | out: |
952 | spin_unlock(&block_group->tree_lock); | |
817d52f8 | 953 | |
0f9dd46c JB |
954 | return ret; |
955 | } | |
fa9c0d79 CM |
956 | |
957 | /* | |
958 | * given a cluster, put all of its extents back into the free space | |
959 | * cache. If a block group is passed, this function will only free | |
960 | * a cluster that belongs to the passed block group. | |
961 | * | |
962 | * Otherwise, it'll get a reference on the block group pointed to by the | |
963 | * cluster and remove the cluster from it. | |
964 | */ | |
965 | int btrfs_return_cluster_to_free_space( | |
966 | struct btrfs_block_group_cache *block_group, | |
967 | struct btrfs_free_cluster *cluster) | |
968 | { | |
969 | int ret; | |
970 | ||
971 | /* first, get a safe pointer to the block group */ | |
972 | spin_lock(&cluster->lock); | |
973 | if (!block_group) { | |
974 | block_group = cluster->block_group; | |
975 | if (!block_group) { | |
976 | spin_unlock(&cluster->lock); | |
977 | return 0; | |
978 | } | |
979 | } else if (cluster->block_group != block_group) { | |
980 | /* someone else has already freed it don't redo their work */ | |
981 | spin_unlock(&cluster->lock); | |
982 | return 0; | |
983 | } | |
984 | atomic_inc(&block_group->count); | |
985 | spin_unlock(&cluster->lock); | |
986 | ||
987 | /* now return any extents the cluster had on it */ | |
988 | spin_lock(&block_group->tree_lock); | |
989 | ret = __btrfs_return_cluster_to_free_space(block_group, cluster); | |
990 | spin_unlock(&block_group->tree_lock); | |
991 | ||
992 | /* finally drop our ref */ | |
993 | btrfs_put_block_group(block_group); | |
994 | return ret; | |
995 | } | |
996 | ||
96303081 JB |
997 | static u64 btrfs_alloc_from_bitmap(struct btrfs_block_group_cache *block_group, |
998 | struct btrfs_free_cluster *cluster, | |
999 | u64 bytes, u64 min_start) | |
1000 | { | |
1001 | struct btrfs_free_space *entry; | |
1002 | int err; | |
1003 | u64 search_start = cluster->window_start; | |
1004 | u64 search_bytes = bytes; | |
1005 | u64 ret = 0; | |
1006 | ||
1007 | spin_lock(&block_group->tree_lock); | |
1008 | spin_lock(&cluster->lock); | |
1009 | ||
1010 | if (!cluster->points_to_bitmap) | |
1011 | goto out; | |
1012 | ||
1013 | if (cluster->block_group != block_group) | |
1014 | goto out; | |
1015 | ||
6606bb97 JB |
1016 | /* |
1017 | * search_start is the beginning of the bitmap, but at some point it may | |
1018 | * be a good idea to point to the actual start of the free area in the | |
1019 | * bitmap, so do the offset_to_bitmap trick anyway, and set bitmap_only | |
1020 | * to 1 to make sure we get the bitmap entry | |
1021 | */ | |
1022 | entry = tree_search_offset(block_group, | |
1023 | offset_to_bitmap(block_group, search_start), | |
1024 | 1, 0); | |
96303081 JB |
1025 | if (!entry || !entry->bitmap) |
1026 | goto out; | |
1027 | ||
1028 | search_start = min_start; | |
1029 | search_bytes = bytes; | |
1030 | ||
1031 | err = search_bitmap(block_group, entry, &search_start, | |
1032 | &search_bytes); | |
1033 | if (err) | |
1034 | goto out; | |
1035 | ||
1036 | ret = search_start; | |
817d52f8 | 1037 | bitmap_clear_bits(block_group, entry, ret, bytes); |
96303081 JB |
1038 | out: |
1039 | spin_unlock(&cluster->lock); | |
1040 | spin_unlock(&block_group->tree_lock); | |
1041 | ||
1042 | return ret; | |
1043 | } | |
1044 | ||
fa9c0d79 CM |
1045 | /* |
1046 | * given a cluster, try to allocate 'bytes' from it, returns 0 | |
1047 | * if it couldn't find anything suitably large, or a logical disk offset | |
1048 | * if things worked out | |
1049 | */ | |
1050 | u64 btrfs_alloc_from_cluster(struct btrfs_block_group_cache *block_group, | |
1051 | struct btrfs_free_cluster *cluster, u64 bytes, | |
1052 | u64 min_start) | |
1053 | { | |
1054 | struct btrfs_free_space *entry = NULL; | |
1055 | struct rb_node *node; | |
1056 | u64 ret = 0; | |
1057 | ||
96303081 JB |
1058 | if (cluster->points_to_bitmap) |
1059 | return btrfs_alloc_from_bitmap(block_group, cluster, bytes, | |
1060 | min_start); | |
1061 | ||
fa9c0d79 CM |
1062 | spin_lock(&cluster->lock); |
1063 | if (bytes > cluster->max_size) | |
1064 | goto out; | |
1065 | ||
1066 | if (cluster->block_group != block_group) | |
1067 | goto out; | |
1068 | ||
1069 | node = rb_first(&cluster->root); | |
1070 | if (!node) | |
1071 | goto out; | |
1072 | ||
1073 | entry = rb_entry(node, struct btrfs_free_space, offset_index); | |
1074 | ||
1075 | while(1) { | |
1076 | if (entry->bytes < bytes || entry->offset < min_start) { | |
1077 | struct rb_node *node; | |
1078 | ||
1079 | node = rb_next(&entry->offset_index); | |
1080 | if (!node) | |
1081 | break; | |
1082 | entry = rb_entry(node, struct btrfs_free_space, | |
1083 | offset_index); | |
1084 | continue; | |
1085 | } | |
1086 | ret = entry->offset; | |
1087 | ||
1088 | entry->offset += bytes; | |
1089 | entry->bytes -= bytes; | |
1090 | ||
1091 | if (entry->bytes == 0) { | |
1092 | rb_erase(&entry->offset_index, &cluster->root); | |
1093 | kfree(entry); | |
1094 | } | |
1095 | break; | |
1096 | } | |
1097 | out: | |
1098 | spin_unlock(&cluster->lock); | |
96303081 | 1099 | |
fa9c0d79 CM |
1100 | return ret; |
1101 | } | |
1102 | ||
96303081 JB |
1103 | static int btrfs_bitmap_cluster(struct btrfs_block_group_cache *block_group, |
1104 | struct btrfs_free_space *entry, | |
1105 | struct btrfs_free_cluster *cluster, | |
1106 | u64 offset, u64 bytes, u64 min_bytes) | |
1107 | { | |
1108 | unsigned long next_zero; | |
1109 | unsigned long i; | |
1110 | unsigned long search_bits; | |
1111 | unsigned long total_bits; | |
1112 | unsigned long found_bits; | |
1113 | unsigned long start = 0; | |
1114 | unsigned long total_found = 0; | |
1115 | bool found = false; | |
1116 | ||
1117 | i = offset_to_bit(entry->offset, block_group->sectorsize, | |
1118 | max_t(u64, offset, entry->offset)); | |
1119 | search_bits = bytes_to_bits(min_bytes, block_group->sectorsize); | |
1120 | total_bits = bytes_to_bits(bytes, block_group->sectorsize); | |
1121 | ||
1122 | again: | |
1123 | found_bits = 0; | |
1124 | for (i = find_next_bit(entry->bitmap, BITS_PER_BITMAP, i); | |
1125 | i < BITS_PER_BITMAP; | |
1126 | i = find_next_bit(entry->bitmap, BITS_PER_BITMAP, i + 1)) { | |
1127 | next_zero = find_next_zero_bit(entry->bitmap, | |
1128 | BITS_PER_BITMAP, i); | |
1129 | if (next_zero - i >= search_bits) { | |
1130 | found_bits = next_zero - i; | |
1131 | break; | |
1132 | } | |
1133 | i = next_zero; | |
1134 | } | |
1135 | ||
1136 | if (!found_bits) | |
1137 | return -1; | |
1138 | ||
1139 | if (!found) { | |
1140 | start = i; | |
1141 | found = true; | |
1142 | } | |
1143 | ||
1144 | total_found += found_bits; | |
1145 | ||
1146 | if (cluster->max_size < found_bits * block_group->sectorsize) | |
1147 | cluster->max_size = found_bits * block_group->sectorsize; | |
1148 | ||
1149 | if (total_found < total_bits) { | |
1150 | i = find_next_bit(entry->bitmap, BITS_PER_BITMAP, next_zero); | |
1151 | if (i - start > total_bits * 2) { | |
1152 | total_found = 0; | |
1153 | cluster->max_size = 0; | |
1154 | found = false; | |
1155 | } | |
1156 | goto again; | |
1157 | } | |
1158 | ||
1159 | cluster->window_start = start * block_group->sectorsize + | |
1160 | entry->offset; | |
1161 | cluster->points_to_bitmap = true; | |
1162 | ||
1163 | return 0; | |
1164 | } | |
1165 | ||
fa9c0d79 CM |
1166 | /* |
1167 | * here we try to find a cluster of blocks in a block group. The goal | |
1168 | * is to find at least bytes free and up to empty_size + bytes free. | |
1169 | * We might not find them all in one contiguous area. | |
1170 | * | |
1171 | * returns zero and sets up cluster if things worked out, otherwise | |
1172 | * it returns -enospc | |
1173 | */ | |
1174 | int btrfs_find_space_cluster(struct btrfs_trans_handle *trans, | |
451d7585 | 1175 | struct btrfs_root *root, |
fa9c0d79 CM |
1176 | struct btrfs_block_group_cache *block_group, |
1177 | struct btrfs_free_cluster *cluster, | |
1178 | u64 offset, u64 bytes, u64 empty_size) | |
1179 | { | |
1180 | struct btrfs_free_space *entry = NULL; | |
1181 | struct rb_node *node; | |
1182 | struct btrfs_free_space *next; | |
96303081 | 1183 | struct btrfs_free_space *last = NULL; |
fa9c0d79 CM |
1184 | u64 min_bytes; |
1185 | u64 window_start; | |
1186 | u64 window_free; | |
1187 | u64 max_extent = 0; | |
96303081 | 1188 | bool found_bitmap = false; |
fa9c0d79 CM |
1189 | int ret; |
1190 | ||
1191 | /* for metadata, allow allocates with more holes */ | |
451d7585 CM |
1192 | if (btrfs_test_opt(root, SSD_SPREAD)) { |
1193 | min_bytes = bytes + empty_size; | |
1194 | } else if (block_group->flags & BTRFS_BLOCK_GROUP_METADATA) { | |
fa9c0d79 CM |
1195 | /* |
1196 | * we want to do larger allocations when we are | |
1197 | * flushing out the delayed refs, it helps prevent | |
1198 | * making more work as we go along. | |
1199 | */ | |
1200 | if (trans->transaction->delayed_refs.flushing) | |
1201 | min_bytes = max(bytes, (bytes + empty_size) >> 1); | |
1202 | else | |
1203 | min_bytes = max(bytes, (bytes + empty_size) >> 4); | |
1204 | } else | |
1205 | min_bytes = max(bytes, (bytes + empty_size) >> 2); | |
1206 | ||
1207 | spin_lock(&block_group->tree_lock); | |
1208 | spin_lock(&cluster->lock); | |
1209 | ||
1210 | /* someone already found a cluster, hooray */ | |
1211 | if (cluster->block_group) { | |
1212 | ret = 0; | |
1213 | goto out; | |
1214 | } | |
1215 | again: | |
96303081 | 1216 | entry = tree_search_offset(block_group, offset, found_bitmap, 1); |
fa9c0d79 CM |
1217 | if (!entry) { |
1218 | ret = -ENOSPC; | |
1219 | goto out; | |
1220 | } | |
96303081 JB |
1221 | |
1222 | /* | |
1223 | * If found_bitmap is true, we exhausted our search for extent entries, | |
1224 | * and we just want to search all of the bitmaps that we can find, and | |
1225 | * ignore any extent entries we find. | |
1226 | */ | |
1227 | while (entry->bitmap || found_bitmap || | |
1228 | (!entry->bitmap && entry->bytes < min_bytes)) { | |
1229 | struct rb_node *node = rb_next(&entry->offset_index); | |
1230 | ||
1231 | if (entry->bitmap && entry->bytes > bytes + empty_size) { | |
1232 | ret = btrfs_bitmap_cluster(block_group, entry, cluster, | |
1233 | offset, bytes + empty_size, | |
1234 | min_bytes); | |
1235 | if (!ret) | |
1236 | goto got_it; | |
1237 | } | |
1238 | ||
1239 | if (!node) { | |
1240 | ret = -ENOSPC; | |
1241 | goto out; | |
1242 | } | |
1243 | entry = rb_entry(node, struct btrfs_free_space, offset_index); | |
1244 | } | |
1245 | ||
1246 | /* | |
1247 | * We already searched all the extent entries from the passed in offset | |
1248 | * to the end and didn't find enough space for the cluster, and we also | |
1249 | * didn't find any bitmaps that met our criteria, just go ahead and exit | |
1250 | */ | |
1251 | if (found_bitmap) { | |
1252 | ret = -ENOSPC; | |
1253 | goto out; | |
1254 | } | |
1255 | ||
1256 | cluster->points_to_bitmap = false; | |
fa9c0d79 CM |
1257 | window_start = entry->offset; |
1258 | window_free = entry->bytes; | |
1259 | last = entry; | |
1260 | max_extent = entry->bytes; | |
1261 | ||
96303081 | 1262 | while (1) { |
fa9c0d79 CM |
1263 | /* out window is just right, lets fill it */ |
1264 | if (window_free >= bytes + empty_size) | |
1265 | break; | |
1266 | ||
1267 | node = rb_next(&last->offset_index); | |
1268 | if (!node) { | |
96303081 JB |
1269 | if (found_bitmap) |
1270 | goto again; | |
fa9c0d79 CM |
1271 | ret = -ENOSPC; |
1272 | goto out; | |
1273 | } | |
1274 | next = rb_entry(node, struct btrfs_free_space, offset_index); | |
1275 | ||
96303081 JB |
1276 | /* |
1277 | * we found a bitmap, so if this search doesn't result in a | |
1278 | * cluster, we know to go and search again for the bitmaps and | |
1279 | * start looking for space there | |
1280 | */ | |
1281 | if (next->bitmap) { | |
1282 | if (!found_bitmap) | |
1283 | offset = next->offset; | |
1284 | found_bitmap = true; | |
1285 | last = next; | |
1286 | continue; | |
1287 | } | |
1288 | ||
fa9c0d79 CM |
1289 | /* |
1290 | * we haven't filled the empty size and the window is | |
1291 | * very large. reset and try again | |
1292 | */ | |
c6044801 CM |
1293 | if (next->offset - (last->offset + last->bytes) > 128 * 1024 || |
1294 | next->offset - window_start > (bytes + empty_size) * 2) { | |
fa9c0d79 CM |
1295 | entry = next; |
1296 | window_start = entry->offset; | |
1297 | window_free = entry->bytes; | |
1298 | last = entry; | |
1299 | max_extent = 0; | |
fa9c0d79 CM |
1300 | } else { |
1301 | last = next; | |
1302 | window_free += next->bytes; | |
1303 | if (entry->bytes > max_extent) | |
1304 | max_extent = entry->bytes; | |
1305 | } | |
1306 | } | |
1307 | ||
1308 | cluster->window_start = entry->offset; | |
1309 | ||
1310 | /* | |
1311 | * now we've found our entries, pull them out of the free space | |
1312 | * cache and put them into the cluster rbtree | |
1313 | * | |
1314 | * The cluster includes an rbtree, but only uses the offset index | |
1315 | * of each free space cache entry. | |
1316 | */ | |
96303081 | 1317 | while (1) { |
fa9c0d79 | 1318 | node = rb_next(&entry->offset_index); |
96303081 JB |
1319 | if (entry->bitmap && node) { |
1320 | entry = rb_entry(node, struct btrfs_free_space, | |
1321 | offset_index); | |
1322 | continue; | |
1323 | } else if (entry->bitmap && !node) { | |
1324 | break; | |
1325 | } | |
1326 | ||
1327 | rb_erase(&entry->offset_index, &block_group->free_space_offset); | |
fa9c0d79 | 1328 | ret = tree_insert_offset(&cluster->root, entry->offset, |
96303081 | 1329 | &entry->offset_index, 0); |
fa9c0d79 CM |
1330 | BUG_ON(ret); |
1331 | ||
1332 | if (!node || entry == last) | |
1333 | break; | |
1334 | ||
1335 | entry = rb_entry(node, struct btrfs_free_space, offset_index); | |
1336 | } | |
96303081 | 1337 | |
fa9c0d79 | 1338 | cluster->max_size = max_extent; |
96303081 JB |
1339 | got_it: |
1340 | ret = 0; | |
fa9c0d79 CM |
1341 | atomic_inc(&block_group->count); |
1342 | list_add_tail(&cluster->block_group_list, &block_group->cluster_list); | |
1343 | cluster->block_group = block_group; | |
1344 | out: | |
1345 | spin_unlock(&cluster->lock); | |
1346 | spin_unlock(&block_group->tree_lock); | |
1347 | ||
1348 | return ret; | |
1349 | } | |
1350 | ||
1351 | /* | |
1352 | * simple code to zero out a cluster | |
1353 | */ | |
1354 | void btrfs_init_free_cluster(struct btrfs_free_cluster *cluster) | |
1355 | { | |
1356 | spin_lock_init(&cluster->lock); | |
1357 | spin_lock_init(&cluster->refill_lock); | |
1358 | cluster->root.rb_node = NULL; | |
1359 | cluster->max_size = 0; | |
96303081 | 1360 | cluster->points_to_bitmap = false; |
fa9c0d79 CM |
1361 | INIT_LIST_HEAD(&cluster->block_group_list); |
1362 | cluster->block_group = NULL; | |
1363 | } | |
1364 |