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