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Commit | Line | Data |
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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> |
5a0e3ad6 | 21 | #include <linux/slab.h> |
96303081 | 22 | #include <linux/math64.h> |
0f9dd46c | 23 | #include "ctree.h" |
fa9c0d79 CM |
24 | #include "free-space-cache.h" |
25 | #include "transaction.h" | |
26 | ||
96303081 JB |
27 | #define BITS_PER_BITMAP (PAGE_CACHE_SIZE * 8) |
28 | #define MAX_CACHE_BYTES_PER_GIG (32 * 1024) | |
0f9dd46c | 29 | |
96303081 JB |
30 | static inline unsigned long offset_to_bit(u64 bitmap_start, u64 sectorsize, |
31 | u64 offset) | |
0f9dd46c | 32 | { |
96303081 JB |
33 | BUG_ON(offset < bitmap_start); |
34 | offset -= bitmap_start; | |
35 | return (unsigned long)(div64_u64(offset, sectorsize)); | |
36 | } | |
0f9dd46c | 37 | |
96303081 JB |
38 | static inline unsigned long bytes_to_bits(u64 bytes, u64 sectorsize) |
39 | { | |
40 | return (unsigned long)(div64_u64(bytes, sectorsize)); | |
41 | } | |
0f9dd46c | 42 | |
96303081 JB |
43 | static inline u64 offset_to_bitmap(struct btrfs_block_group_cache *block_group, |
44 | u64 offset) | |
45 | { | |
46 | u64 bitmap_start; | |
47 | u64 bytes_per_bitmap; | |
0f9dd46c | 48 | |
96303081 JB |
49 | bytes_per_bitmap = BITS_PER_BITMAP * block_group->sectorsize; |
50 | bitmap_start = offset - block_group->key.objectid; | |
51 | bitmap_start = div64_u64(bitmap_start, bytes_per_bitmap); | |
52 | bitmap_start *= bytes_per_bitmap; | |
53 | bitmap_start += block_group->key.objectid; | |
0f9dd46c | 54 | |
96303081 | 55 | return bitmap_start; |
0f9dd46c JB |
56 | } |
57 | ||
96303081 JB |
58 | static int tree_insert_offset(struct rb_root *root, u64 offset, |
59 | struct rb_node *node, int bitmap) | |
0f9dd46c JB |
60 | { |
61 | struct rb_node **p = &root->rb_node; | |
62 | struct rb_node *parent = NULL; | |
63 | struct btrfs_free_space *info; | |
64 | ||
65 | while (*p) { | |
66 | parent = *p; | |
96303081 | 67 | info = rb_entry(parent, struct btrfs_free_space, offset_index); |
0f9dd46c | 68 | |
96303081 | 69 | if (offset < info->offset) { |
0f9dd46c | 70 | p = &(*p)->rb_left; |
96303081 | 71 | } else if (offset > info->offset) { |
0f9dd46c | 72 | p = &(*p)->rb_right; |
96303081 JB |
73 | } else { |
74 | /* | |
75 | * we could have a bitmap entry and an extent entry | |
76 | * share the same offset. If this is the case, we want | |
77 | * the extent entry to always be found first if we do a | |
78 | * linear search through the tree, since we want to have | |
79 | * the quickest allocation time, and allocating from an | |
80 | * extent is faster than allocating from a bitmap. So | |
81 | * if we're inserting a bitmap and we find an entry at | |
82 | * this offset, we want to go right, or after this entry | |
83 | * logically. If we are inserting an extent and we've | |
84 | * found a bitmap, we want to go left, or before | |
85 | * logically. | |
86 | */ | |
87 | if (bitmap) { | |
88 | WARN_ON(info->bitmap); | |
89 | p = &(*p)->rb_right; | |
90 | } else { | |
91 | WARN_ON(!info->bitmap); | |
92 | p = &(*p)->rb_left; | |
93 | } | |
94 | } | |
0f9dd46c JB |
95 | } |
96 | ||
97 | rb_link_node(node, parent, p); | |
98 | rb_insert_color(node, root); | |
99 | ||
100 | return 0; | |
101 | } | |
102 | ||
103 | /* | |
70cb0743 JB |
104 | * searches the tree for the given offset. |
105 | * | |
96303081 JB |
106 | * fuzzy - If this is set, then we are trying to make an allocation, and we just |
107 | * want a section that has at least bytes size and comes at or after the given | |
108 | * offset. | |
0f9dd46c | 109 | */ |
96303081 JB |
110 | static struct btrfs_free_space * |
111 | tree_search_offset(struct btrfs_block_group_cache *block_group, | |
112 | u64 offset, int bitmap_only, int fuzzy) | |
0f9dd46c | 113 | { |
96303081 JB |
114 | struct rb_node *n = block_group->free_space_offset.rb_node; |
115 | struct btrfs_free_space *entry, *prev = NULL; | |
116 | ||
117 | /* find entry that is closest to the 'offset' */ | |
118 | while (1) { | |
119 | if (!n) { | |
120 | entry = NULL; | |
121 | break; | |
122 | } | |
0f9dd46c | 123 | |
0f9dd46c | 124 | entry = rb_entry(n, struct btrfs_free_space, offset_index); |
96303081 | 125 | prev = entry; |
0f9dd46c | 126 | |
96303081 | 127 | if (offset < entry->offset) |
0f9dd46c | 128 | n = n->rb_left; |
96303081 | 129 | else if (offset > entry->offset) |
0f9dd46c | 130 | n = n->rb_right; |
96303081 | 131 | else |
0f9dd46c | 132 | break; |
0f9dd46c JB |
133 | } |
134 | ||
96303081 JB |
135 | if (bitmap_only) { |
136 | if (!entry) | |
137 | return NULL; | |
138 | if (entry->bitmap) | |
139 | return entry; | |
0f9dd46c | 140 | |
96303081 JB |
141 | /* |
142 | * bitmap entry and extent entry may share same offset, | |
143 | * in that case, bitmap entry comes after extent entry. | |
144 | */ | |
145 | n = rb_next(n); | |
146 | if (!n) | |
147 | return NULL; | |
148 | entry = rb_entry(n, struct btrfs_free_space, offset_index); | |
149 | if (entry->offset != offset) | |
150 | return NULL; | |
0f9dd46c | 151 | |
96303081 JB |
152 | WARN_ON(!entry->bitmap); |
153 | return entry; | |
154 | } else if (entry) { | |
155 | if (entry->bitmap) { | |
0f9dd46c | 156 | /* |
96303081 JB |
157 | * if previous extent entry covers the offset, |
158 | * we should return it instead of the bitmap entry | |
0f9dd46c | 159 | */ |
96303081 JB |
160 | n = &entry->offset_index; |
161 | while (1) { | |
162 | n = rb_prev(n); | |
163 | if (!n) | |
164 | break; | |
165 | prev = rb_entry(n, struct btrfs_free_space, | |
166 | offset_index); | |
167 | if (!prev->bitmap) { | |
168 | if (prev->offset + prev->bytes > offset) | |
169 | entry = prev; | |
170 | break; | |
171 | } | |
0f9dd46c | 172 | } |
96303081 JB |
173 | } |
174 | return entry; | |
175 | } | |
176 | ||
177 | if (!prev) | |
178 | return NULL; | |
179 | ||
180 | /* find last entry before the 'offset' */ | |
181 | entry = prev; | |
182 | if (entry->offset > offset) { | |
183 | n = rb_prev(&entry->offset_index); | |
184 | if (n) { | |
185 | entry = rb_entry(n, struct btrfs_free_space, | |
186 | offset_index); | |
187 | BUG_ON(entry->offset > offset); | |
0f9dd46c | 188 | } else { |
96303081 JB |
189 | if (fuzzy) |
190 | return entry; | |
191 | else | |
192 | return NULL; | |
0f9dd46c JB |
193 | } |
194 | } | |
195 | ||
96303081 JB |
196 | if (entry->bitmap) { |
197 | n = &entry->offset_index; | |
198 | while (1) { | |
199 | n = rb_prev(n); | |
200 | if (!n) | |
201 | break; | |
202 | prev = rb_entry(n, struct btrfs_free_space, | |
203 | offset_index); | |
204 | if (!prev->bitmap) { | |
205 | if (prev->offset + prev->bytes > offset) | |
206 | return prev; | |
207 | break; | |
208 | } | |
209 | } | |
210 | if (entry->offset + BITS_PER_BITMAP * | |
211 | block_group->sectorsize > offset) | |
212 | return entry; | |
213 | } else if (entry->offset + entry->bytes > offset) | |
214 | return entry; | |
215 | ||
216 | if (!fuzzy) | |
217 | return NULL; | |
218 | ||
219 | while (1) { | |
220 | if (entry->bitmap) { | |
221 | if (entry->offset + BITS_PER_BITMAP * | |
222 | block_group->sectorsize > offset) | |
223 | break; | |
224 | } else { | |
225 | if (entry->offset + entry->bytes > offset) | |
226 | break; | |
227 | } | |
228 | ||
229 | n = rb_next(&entry->offset_index); | |
230 | if (!n) | |
231 | return NULL; | |
232 | entry = rb_entry(n, struct btrfs_free_space, offset_index); | |
233 | } | |
234 | return entry; | |
0f9dd46c JB |
235 | } |
236 | ||
237 | static void unlink_free_space(struct btrfs_block_group_cache *block_group, | |
238 | struct btrfs_free_space *info) | |
239 | { | |
240 | rb_erase(&info->offset_index, &block_group->free_space_offset); | |
96303081 | 241 | block_group->free_extents--; |
817d52f8 | 242 | block_group->free_space -= info->bytes; |
0f9dd46c JB |
243 | } |
244 | ||
245 | static int link_free_space(struct btrfs_block_group_cache *block_group, | |
246 | struct btrfs_free_space *info) | |
247 | { | |
248 | int ret = 0; | |
249 | ||
96303081 | 250 | BUG_ON(!info->bitmap && !info->bytes); |
0f9dd46c | 251 | ret = tree_insert_offset(&block_group->free_space_offset, info->offset, |
96303081 | 252 | &info->offset_index, (info->bitmap != NULL)); |
0f9dd46c JB |
253 | if (ret) |
254 | return ret; | |
255 | ||
817d52f8 | 256 | block_group->free_space += info->bytes; |
96303081 JB |
257 | block_group->free_extents++; |
258 | return ret; | |
259 | } | |
260 | ||
261 | static void recalculate_thresholds(struct btrfs_block_group_cache *block_group) | |
262 | { | |
25891f79 JB |
263 | u64 max_bytes; |
264 | u64 bitmap_bytes; | |
265 | u64 extent_bytes; | |
96303081 JB |
266 | |
267 | /* | |
268 | * The goal is to keep the total amount of memory used per 1gb of space | |
269 | * at or below 32k, so we need to adjust how much memory we allow to be | |
270 | * used by extent based free space tracking | |
271 | */ | |
272 | max_bytes = MAX_CACHE_BYTES_PER_GIG * | |
273 | (div64_u64(block_group->key.offset, 1024 * 1024 * 1024)); | |
274 | ||
25891f79 JB |
275 | /* |
276 | * we want to account for 1 more bitmap than what we have so we can make | |
277 | * sure we don't go over our overall goal of MAX_CACHE_BYTES_PER_GIG as | |
278 | * we add more bitmaps. | |
279 | */ | |
280 | bitmap_bytes = (block_group->total_bitmaps + 1) * PAGE_CACHE_SIZE; | |
96303081 | 281 | |
25891f79 JB |
282 | if (bitmap_bytes >= max_bytes) { |
283 | block_group->extents_thresh = 0; | |
284 | return; | |
285 | } | |
96303081 | 286 | |
25891f79 JB |
287 | /* |
288 | * we want the extent entry threshold to always be at most 1/2 the maxw | |
289 | * bytes we can have, or whatever is less than that. | |
290 | */ | |
291 | extent_bytes = max_bytes - bitmap_bytes; | |
292 | extent_bytes = min_t(u64, extent_bytes, div64_u64(max_bytes, 2)); | |
96303081 | 293 | |
25891f79 JB |
294 | block_group->extents_thresh = |
295 | div64_u64(extent_bytes, (sizeof(struct btrfs_free_space))); | |
96303081 JB |
296 | } |
297 | ||
817d52f8 JB |
298 | static void bitmap_clear_bits(struct btrfs_block_group_cache *block_group, |
299 | struct btrfs_free_space *info, u64 offset, | |
300 | u64 bytes) | |
96303081 JB |
301 | { |
302 | unsigned long start, end; | |
303 | unsigned long i; | |
304 | ||
817d52f8 JB |
305 | start = offset_to_bit(info->offset, block_group->sectorsize, offset); |
306 | end = start + bytes_to_bits(bytes, block_group->sectorsize); | |
96303081 JB |
307 | BUG_ON(end > BITS_PER_BITMAP); |
308 | ||
309 | for (i = start; i < end; i++) | |
310 | clear_bit(i, info->bitmap); | |
311 | ||
312 | info->bytes -= bytes; | |
817d52f8 | 313 | block_group->free_space -= bytes; |
96303081 JB |
314 | } |
315 | ||
817d52f8 JB |
316 | static void bitmap_set_bits(struct btrfs_block_group_cache *block_group, |
317 | struct btrfs_free_space *info, u64 offset, | |
318 | u64 bytes) | |
96303081 JB |
319 | { |
320 | unsigned long start, end; | |
321 | unsigned long i; | |
322 | ||
817d52f8 JB |
323 | start = offset_to_bit(info->offset, block_group->sectorsize, offset); |
324 | end = start + bytes_to_bits(bytes, block_group->sectorsize); | |
96303081 JB |
325 | BUG_ON(end > BITS_PER_BITMAP); |
326 | ||
327 | for (i = start; i < end; i++) | |
328 | set_bit(i, info->bitmap); | |
329 | ||
330 | info->bytes += bytes; | |
817d52f8 | 331 | block_group->free_space += bytes; |
96303081 JB |
332 | } |
333 | ||
334 | static int search_bitmap(struct btrfs_block_group_cache *block_group, | |
335 | struct btrfs_free_space *bitmap_info, u64 *offset, | |
336 | u64 *bytes) | |
337 | { | |
338 | unsigned long found_bits = 0; | |
339 | unsigned long bits, i; | |
340 | unsigned long next_zero; | |
341 | ||
342 | i = offset_to_bit(bitmap_info->offset, block_group->sectorsize, | |
343 | max_t(u64, *offset, bitmap_info->offset)); | |
344 | bits = bytes_to_bits(*bytes, block_group->sectorsize); | |
345 | ||
346 | for (i = find_next_bit(bitmap_info->bitmap, BITS_PER_BITMAP, i); | |
347 | i < BITS_PER_BITMAP; | |
348 | i = find_next_bit(bitmap_info->bitmap, BITS_PER_BITMAP, i + 1)) { | |
349 | next_zero = find_next_zero_bit(bitmap_info->bitmap, | |
350 | BITS_PER_BITMAP, i); | |
351 | if ((next_zero - i) >= bits) { | |
352 | found_bits = next_zero - i; | |
353 | break; | |
354 | } | |
355 | i = next_zero; | |
356 | } | |
357 | ||
358 | if (found_bits) { | |
359 | *offset = (u64)(i * block_group->sectorsize) + | |
360 | bitmap_info->offset; | |
361 | *bytes = (u64)(found_bits) * block_group->sectorsize; | |
362 | return 0; | |
363 | } | |
364 | ||
365 | return -1; | |
366 | } | |
367 | ||
368 | static struct btrfs_free_space *find_free_space(struct btrfs_block_group_cache | |
369 | *block_group, u64 *offset, | |
370 | u64 *bytes, int debug) | |
371 | { | |
372 | struct btrfs_free_space *entry; | |
373 | struct rb_node *node; | |
374 | int ret; | |
375 | ||
376 | if (!block_group->free_space_offset.rb_node) | |
377 | return NULL; | |
378 | ||
379 | entry = tree_search_offset(block_group, | |
380 | offset_to_bitmap(block_group, *offset), | |
381 | 0, 1); | |
382 | if (!entry) | |
383 | return NULL; | |
384 | ||
385 | for (node = &entry->offset_index; node; node = rb_next(node)) { | |
386 | entry = rb_entry(node, struct btrfs_free_space, offset_index); | |
387 | if (entry->bytes < *bytes) | |
388 | continue; | |
389 | ||
390 | if (entry->bitmap) { | |
391 | ret = search_bitmap(block_group, entry, offset, bytes); | |
392 | if (!ret) | |
393 | return entry; | |
394 | continue; | |
395 | } | |
396 | ||
397 | *offset = entry->offset; | |
398 | *bytes = entry->bytes; | |
399 | return entry; | |
400 | } | |
401 | ||
402 | return NULL; | |
403 | } | |
404 | ||
405 | static void add_new_bitmap(struct btrfs_block_group_cache *block_group, | |
406 | struct btrfs_free_space *info, u64 offset) | |
407 | { | |
408 | u64 bytes_per_bg = BITS_PER_BITMAP * block_group->sectorsize; | |
409 | int max_bitmaps = (int)div64_u64(block_group->key.offset + | |
410 | bytes_per_bg - 1, bytes_per_bg); | |
411 | BUG_ON(block_group->total_bitmaps >= max_bitmaps); | |
412 | ||
413 | info->offset = offset_to_bitmap(block_group, offset); | |
f019f426 | 414 | info->bytes = 0; |
96303081 JB |
415 | link_free_space(block_group, info); |
416 | block_group->total_bitmaps++; | |
417 | ||
418 | recalculate_thresholds(block_group); | |
419 | } | |
420 | ||
421 | static noinline int remove_from_bitmap(struct btrfs_block_group_cache *block_group, | |
422 | struct btrfs_free_space *bitmap_info, | |
423 | u64 *offset, u64 *bytes) | |
424 | { | |
425 | u64 end; | |
6606bb97 JB |
426 | u64 search_start, search_bytes; |
427 | int ret; | |
96303081 JB |
428 | |
429 | again: | |
430 | end = bitmap_info->offset + | |
431 | (u64)(BITS_PER_BITMAP * block_group->sectorsize) - 1; | |
432 | ||
6606bb97 JB |
433 | /* |
434 | * XXX - this can go away after a few releases. | |
435 | * | |
436 | * since the only user of btrfs_remove_free_space is the tree logging | |
437 | * stuff, and the only way to test that is under crash conditions, we | |
438 | * want to have this debug stuff here just in case somethings not | |
439 | * working. Search the bitmap for the space we are trying to use to | |
440 | * make sure its actually there. If its not there then we need to stop | |
441 | * because something has gone wrong. | |
442 | */ | |
443 | search_start = *offset; | |
444 | search_bytes = *bytes; | |
445 | ret = search_bitmap(block_group, bitmap_info, &search_start, | |
446 | &search_bytes); | |
447 | BUG_ON(ret < 0 || search_start != *offset); | |
448 | ||
96303081 | 449 | if (*offset > bitmap_info->offset && *offset + *bytes > end) { |
817d52f8 JB |
450 | bitmap_clear_bits(block_group, bitmap_info, *offset, |
451 | end - *offset + 1); | |
96303081 JB |
452 | *bytes -= end - *offset + 1; |
453 | *offset = end + 1; | |
454 | } else if (*offset >= bitmap_info->offset && *offset + *bytes <= end) { | |
817d52f8 | 455 | bitmap_clear_bits(block_group, bitmap_info, *offset, *bytes); |
96303081 JB |
456 | *bytes = 0; |
457 | } | |
458 | ||
459 | if (*bytes) { | |
6606bb97 | 460 | struct rb_node *next = rb_next(&bitmap_info->offset_index); |
96303081 JB |
461 | if (!bitmap_info->bytes) { |
462 | unlink_free_space(block_group, bitmap_info); | |
463 | kfree(bitmap_info->bitmap); | |
464 | kfree(bitmap_info); | |
465 | block_group->total_bitmaps--; | |
466 | recalculate_thresholds(block_group); | |
467 | } | |
468 | ||
6606bb97 JB |
469 | /* |
470 | * no entry after this bitmap, but we still have bytes to | |
471 | * remove, so something has gone wrong. | |
472 | */ | |
473 | if (!next) | |
96303081 JB |
474 | return -EINVAL; |
475 | ||
6606bb97 JB |
476 | bitmap_info = rb_entry(next, struct btrfs_free_space, |
477 | offset_index); | |
478 | ||
479 | /* | |
480 | * if the next entry isn't a bitmap we need to return to let the | |
481 | * extent stuff do its work. | |
482 | */ | |
96303081 JB |
483 | if (!bitmap_info->bitmap) |
484 | return -EAGAIN; | |
485 | ||
6606bb97 JB |
486 | /* |
487 | * Ok the next item is a bitmap, but it may not actually hold | |
488 | * the information for the rest of this free space stuff, so | |
489 | * look for it, and if we don't find it return so we can try | |
490 | * everything over again. | |
491 | */ | |
492 | search_start = *offset; | |
493 | search_bytes = *bytes; | |
494 | ret = search_bitmap(block_group, bitmap_info, &search_start, | |
495 | &search_bytes); | |
496 | if (ret < 0 || search_start != *offset) | |
497 | return -EAGAIN; | |
498 | ||
96303081 JB |
499 | goto again; |
500 | } else if (!bitmap_info->bytes) { | |
501 | unlink_free_space(block_group, bitmap_info); | |
502 | kfree(bitmap_info->bitmap); | |
503 | kfree(bitmap_info); | |
504 | block_group->total_bitmaps--; | |
505 | recalculate_thresholds(block_group); | |
506 | } | |
507 | ||
508 | return 0; | |
509 | } | |
510 | ||
511 | static int insert_into_bitmap(struct btrfs_block_group_cache *block_group, | |
512 | struct btrfs_free_space *info) | |
513 | { | |
514 | struct btrfs_free_space *bitmap_info; | |
515 | int added = 0; | |
516 | u64 bytes, offset, end; | |
517 | int ret; | |
518 | ||
519 | /* | |
520 | * If we are below the extents threshold then we can add this as an | |
521 | * extent, and don't have to deal with the bitmap | |
522 | */ | |
523 | if (block_group->free_extents < block_group->extents_thresh && | |
524 | info->bytes > block_group->sectorsize * 4) | |
525 | return 0; | |
526 | ||
527 | /* | |
528 | * some block groups are so tiny they can't be enveloped by a bitmap, so | |
529 | * don't even bother to create a bitmap for this | |
530 | */ | |
531 | if (BITS_PER_BITMAP * block_group->sectorsize > | |
532 | block_group->key.offset) | |
533 | return 0; | |
534 | ||
535 | bytes = info->bytes; | |
536 | offset = info->offset; | |
537 | ||
538 | again: | |
539 | bitmap_info = tree_search_offset(block_group, | |
540 | offset_to_bitmap(block_group, offset), | |
541 | 1, 0); | |
542 | if (!bitmap_info) { | |
543 | BUG_ON(added); | |
544 | goto new_bitmap; | |
545 | } | |
546 | ||
547 | end = bitmap_info->offset + | |
548 | (u64)(BITS_PER_BITMAP * block_group->sectorsize); | |
549 | ||
550 | if (offset >= bitmap_info->offset && offset + bytes > end) { | |
817d52f8 JB |
551 | bitmap_set_bits(block_group, bitmap_info, offset, |
552 | end - offset); | |
96303081 JB |
553 | bytes -= end - offset; |
554 | offset = end; | |
555 | added = 0; | |
556 | } else if (offset >= bitmap_info->offset && offset + bytes <= end) { | |
817d52f8 | 557 | bitmap_set_bits(block_group, bitmap_info, offset, bytes); |
96303081 JB |
558 | bytes = 0; |
559 | } else { | |
560 | BUG(); | |
561 | } | |
562 | ||
563 | if (!bytes) { | |
564 | ret = 1; | |
565 | goto out; | |
566 | } else | |
567 | goto again; | |
568 | ||
569 | new_bitmap: | |
570 | if (info && info->bitmap) { | |
571 | add_new_bitmap(block_group, info, offset); | |
572 | added = 1; | |
573 | info = NULL; | |
574 | goto again; | |
575 | } else { | |
576 | spin_unlock(&block_group->tree_lock); | |
577 | ||
578 | /* no pre-allocated info, allocate a new one */ | |
579 | if (!info) { | |
580 | info = kzalloc(sizeof(struct btrfs_free_space), | |
581 | GFP_NOFS); | |
582 | if (!info) { | |
583 | spin_lock(&block_group->tree_lock); | |
584 | ret = -ENOMEM; | |
585 | goto out; | |
586 | } | |
587 | } | |
588 | ||
589 | /* allocate the bitmap */ | |
590 | info->bitmap = kzalloc(PAGE_CACHE_SIZE, GFP_NOFS); | |
591 | spin_lock(&block_group->tree_lock); | |
592 | if (!info->bitmap) { | |
593 | ret = -ENOMEM; | |
594 | goto out; | |
595 | } | |
596 | goto again; | |
597 | } | |
598 | ||
599 | out: | |
600 | if (info) { | |
601 | if (info->bitmap) | |
602 | kfree(info->bitmap); | |
603 | kfree(info); | |
604 | } | |
0f9dd46c JB |
605 | |
606 | return ret; | |
607 | } | |
608 | ||
6226cb0a JB |
609 | int btrfs_add_free_space(struct btrfs_block_group_cache *block_group, |
610 | u64 offset, u64 bytes) | |
0f9dd46c | 611 | { |
96303081 JB |
612 | struct btrfs_free_space *right_info = NULL; |
613 | struct btrfs_free_space *left_info = NULL; | |
0f9dd46c | 614 | struct btrfs_free_space *info = NULL; |
0f9dd46c JB |
615 | int ret = 0; |
616 | ||
6226cb0a JB |
617 | info = kzalloc(sizeof(struct btrfs_free_space), GFP_NOFS); |
618 | if (!info) | |
619 | return -ENOMEM; | |
620 | ||
621 | info->offset = offset; | |
622 | info->bytes = bytes; | |
623 | ||
624 | spin_lock(&block_group->tree_lock); | |
625 | ||
0f9dd46c JB |
626 | /* |
627 | * first we want to see if there is free space adjacent to the range we | |
628 | * are adding, if there is remove that struct and add a new one to | |
629 | * cover the entire range | |
630 | */ | |
96303081 JB |
631 | right_info = tree_search_offset(block_group, offset + bytes, 0, 0); |
632 | if (right_info && rb_prev(&right_info->offset_index)) | |
633 | left_info = rb_entry(rb_prev(&right_info->offset_index), | |
634 | struct btrfs_free_space, offset_index); | |
635 | else | |
636 | left_info = tree_search_offset(block_group, offset - 1, 0, 0); | |
0f9dd46c | 637 | |
96303081 JB |
638 | /* |
639 | * If there was no extent directly to the left or right of this new | |
640 | * extent then we know we're going to have to allocate a new extent, so | |
641 | * before we do that see if we need to drop this into a bitmap | |
642 | */ | |
643 | if ((!left_info || left_info->bitmap) && | |
644 | (!right_info || right_info->bitmap)) { | |
645 | ret = insert_into_bitmap(block_group, info); | |
646 | ||
647 | if (ret < 0) { | |
648 | goto out; | |
649 | } else if (ret) { | |
650 | ret = 0; | |
651 | goto out; | |
652 | } | |
653 | } | |
654 | ||
655 | if (right_info && !right_info->bitmap) { | |
0f9dd46c | 656 | unlink_free_space(block_group, right_info); |
6226cb0a JB |
657 | info->bytes += right_info->bytes; |
658 | kfree(right_info); | |
0f9dd46c JB |
659 | } |
660 | ||
96303081 JB |
661 | if (left_info && !left_info->bitmap && |
662 | left_info->offset + left_info->bytes == offset) { | |
0f9dd46c | 663 | unlink_free_space(block_group, left_info); |
6226cb0a JB |
664 | info->offset = left_info->offset; |
665 | info->bytes += left_info->bytes; | |
666 | kfree(left_info); | |
0f9dd46c JB |
667 | } |
668 | ||
0f9dd46c JB |
669 | ret = link_free_space(block_group, info); |
670 | if (ret) | |
671 | kfree(info); | |
96303081 | 672 | out: |
6226cb0a JB |
673 | spin_unlock(&block_group->tree_lock); |
674 | ||
0f9dd46c | 675 | if (ret) { |
96303081 | 676 | printk(KERN_CRIT "btrfs: unable to add free space :%d\n", ret); |
c293498b | 677 | BUG_ON(ret == -EEXIST); |
0f9dd46c JB |
678 | } |
679 | ||
0f9dd46c JB |
680 | return ret; |
681 | } | |
682 | ||
6226cb0a JB |
683 | int btrfs_remove_free_space(struct btrfs_block_group_cache *block_group, |
684 | u64 offset, u64 bytes) | |
0f9dd46c JB |
685 | { |
686 | struct btrfs_free_space *info; | |
96303081 | 687 | struct btrfs_free_space *next_info = NULL; |
0f9dd46c JB |
688 | int ret = 0; |
689 | ||
6226cb0a JB |
690 | spin_lock(&block_group->tree_lock); |
691 | ||
96303081 JB |
692 | again: |
693 | info = tree_search_offset(block_group, offset, 0, 0); | |
694 | if (!info) { | |
6606bb97 JB |
695 | /* |
696 | * oops didn't find an extent that matched the space we wanted | |
697 | * to remove, look for a bitmap instead | |
698 | */ | |
699 | info = tree_search_offset(block_group, | |
700 | offset_to_bitmap(block_group, offset), | |
701 | 1, 0); | |
702 | if (!info) { | |
703 | WARN_ON(1); | |
704 | goto out_lock; | |
705 | } | |
96303081 JB |
706 | } |
707 | ||
708 | if (info->bytes < bytes && rb_next(&info->offset_index)) { | |
709 | u64 end; | |
710 | next_info = rb_entry(rb_next(&info->offset_index), | |
711 | struct btrfs_free_space, | |
712 | offset_index); | |
713 | ||
714 | if (next_info->bitmap) | |
715 | end = next_info->offset + BITS_PER_BITMAP * | |
716 | block_group->sectorsize - 1; | |
717 | else | |
718 | end = next_info->offset + next_info->bytes; | |
719 | ||
720 | if (next_info->bytes < bytes || | |
721 | next_info->offset > offset || offset > end) { | |
722 | printk(KERN_CRIT "Found free space at %llu, size %llu," | |
723 | " trying to use %llu\n", | |
724 | (unsigned long long)info->offset, | |
725 | (unsigned long long)info->bytes, | |
726 | (unsigned long long)bytes); | |
0f9dd46c JB |
727 | WARN_ON(1); |
728 | ret = -EINVAL; | |
96303081 | 729 | goto out_lock; |
0f9dd46c | 730 | } |
0f9dd46c | 731 | |
96303081 JB |
732 | info = next_info; |
733 | } | |
734 | ||
735 | if (info->bytes == bytes) { | |
736 | unlink_free_space(block_group, info); | |
737 | if (info->bitmap) { | |
738 | kfree(info->bitmap); | |
739 | block_group->total_bitmaps--; | |
0f9dd46c | 740 | } |
96303081 JB |
741 | kfree(info); |
742 | goto out_lock; | |
743 | } | |
0f9dd46c | 744 | |
96303081 JB |
745 | if (!info->bitmap && info->offset == offset) { |
746 | unlink_free_space(block_group, info); | |
0f9dd46c JB |
747 | info->offset += bytes; |
748 | info->bytes -= bytes; | |
96303081 JB |
749 | link_free_space(block_group, info); |
750 | goto out_lock; | |
751 | } | |
0f9dd46c | 752 | |
96303081 JB |
753 | if (!info->bitmap && info->offset <= offset && |
754 | info->offset + info->bytes >= offset + bytes) { | |
9b49c9b9 CM |
755 | u64 old_start = info->offset; |
756 | /* | |
757 | * we're freeing space in the middle of the info, | |
758 | * this can happen during tree log replay | |
759 | * | |
760 | * first unlink the old info and then | |
761 | * insert it again after the hole we're creating | |
762 | */ | |
763 | unlink_free_space(block_group, info); | |
764 | if (offset + bytes < info->offset + info->bytes) { | |
765 | u64 old_end = info->offset + info->bytes; | |
766 | ||
767 | info->offset = offset + bytes; | |
768 | info->bytes = old_end - info->offset; | |
769 | ret = link_free_space(block_group, info); | |
96303081 JB |
770 | WARN_ON(ret); |
771 | if (ret) | |
772 | goto out_lock; | |
9b49c9b9 CM |
773 | } else { |
774 | /* the hole we're creating ends at the end | |
775 | * of the info struct, just free the info | |
776 | */ | |
777 | kfree(info); | |
778 | } | |
6226cb0a | 779 | spin_unlock(&block_group->tree_lock); |
96303081 JB |
780 | |
781 | /* step two, insert a new info struct to cover | |
782 | * anything before the hole | |
9b49c9b9 | 783 | */ |
6226cb0a JB |
784 | ret = btrfs_add_free_space(block_group, old_start, |
785 | offset - old_start); | |
96303081 JB |
786 | WARN_ON(ret); |
787 | goto out; | |
0f9dd46c | 788 | } |
96303081 JB |
789 | |
790 | ret = remove_from_bitmap(block_group, info, &offset, &bytes); | |
791 | if (ret == -EAGAIN) | |
792 | goto again; | |
793 | BUG_ON(ret); | |
794 | out_lock: | |
795 | spin_unlock(&block_group->tree_lock); | |
0f9dd46c | 796 | out: |
25179201 JB |
797 | return ret; |
798 | } | |
799 | ||
0f9dd46c JB |
800 | void btrfs_dump_free_space(struct btrfs_block_group_cache *block_group, |
801 | u64 bytes) | |
802 | { | |
803 | struct btrfs_free_space *info; | |
804 | struct rb_node *n; | |
805 | int count = 0; | |
806 | ||
807 | for (n = rb_first(&block_group->free_space_offset); n; n = rb_next(n)) { | |
808 | info = rb_entry(n, struct btrfs_free_space, offset_index); | |
809 | if (info->bytes >= bytes) | |
810 | count++; | |
96303081 | 811 | printk(KERN_CRIT "entry offset %llu, bytes %llu, bitmap %s\n", |
21380931 | 812 | (unsigned long long)info->offset, |
96303081 JB |
813 | (unsigned long long)info->bytes, |
814 | (info->bitmap) ? "yes" : "no"); | |
0f9dd46c | 815 | } |
96303081 JB |
816 | printk(KERN_INFO "block group has cluster?: %s\n", |
817 | list_empty(&block_group->cluster_list) ? "no" : "yes"); | |
0f9dd46c JB |
818 | printk(KERN_INFO "%d blocks of free space at or bigger than bytes is" |
819 | "\n", count); | |
820 | } | |
821 | ||
822 | u64 btrfs_block_group_free_space(struct btrfs_block_group_cache *block_group) | |
823 | { | |
824 | struct btrfs_free_space *info; | |
825 | struct rb_node *n; | |
826 | u64 ret = 0; | |
827 | ||
828 | for (n = rb_first(&block_group->free_space_offset); n; | |
829 | n = rb_next(n)) { | |
830 | info = rb_entry(n, struct btrfs_free_space, offset_index); | |
831 | ret += info->bytes; | |
832 | } | |
833 | ||
834 | return ret; | |
835 | } | |
836 | ||
fa9c0d79 CM |
837 | /* |
838 | * for a given cluster, put all of its extents back into the free | |
839 | * space cache. If the block group passed doesn't match the block group | |
840 | * pointed to by the cluster, someone else raced in and freed the | |
841 | * cluster already. In that case, we just return without changing anything | |
842 | */ | |
843 | static int | |
844 | __btrfs_return_cluster_to_free_space( | |
845 | struct btrfs_block_group_cache *block_group, | |
846 | struct btrfs_free_cluster *cluster) | |
847 | { | |
848 | struct btrfs_free_space *entry; | |
849 | struct rb_node *node; | |
96303081 | 850 | bool bitmap; |
fa9c0d79 CM |
851 | |
852 | spin_lock(&cluster->lock); | |
853 | if (cluster->block_group != block_group) | |
854 | goto out; | |
855 | ||
96303081 JB |
856 | bitmap = cluster->points_to_bitmap; |
857 | cluster->block_group = NULL; | |
fa9c0d79 | 858 | cluster->window_start = 0; |
96303081 JB |
859 | list_del_init(&cluster->block_group_list); |
860 | cluster->points_to_bitmap = false; | |
861 | ||
862 | if (bitmap) | |
863 | goto out; | |
864 | ||
fa9c0d79 | 865 | node = rb_first(&cluster->root); |
96303081 | 866 | while (node) { |
fa9c0d79 CM |
867 | entry = rb_entry(node, struct btrfs_free_space, offset_index); |
868 | node = rb_next(&entry->offset_index); | |
869 | rb_erase(&entry->offset_index, &cluster->root); | |
96303081 JB |
870 | BUG_ON(entry->bitmap); |
871 | tree_insert_offset(&block_group->free_space_offset, | |
872 | entry->offset, &entry->offset_index, 0); | |
fa9c0d79 | 873 | } |
6bef4d31 | 874 | cluster->root = RB_ROOT; |
96303081 | 875 | |
fa9c0d79 CM |
876 | out: |
877 | spin_unlock(&cluster->lock); | |
96303081 | 878 | btrfs_put_block_group(block_group); |
fa9c0d79 CM |
879 | return 0; |
880 | } | |
881 | ||
0f9dd46c JB |
882 | void btrfs_remove_free_space_cache(struct btrfs_block_group_cache *block_group) |
883 | { | |
884 | struct btrfs_free_space *info; | |
885 | struct rb_node *node; | |
fa9c0d79 | 886 | struct btrfs_free_cluster *cluster; |
96303081 | 887 | struct list_head *head; |
0f9dd46c | 888 | |
6226cb0a | 889 | spin_lock(&block_group->tree_lock); |
96303081 JB |
890 | while ((head = block_group->cluster_list.next) != |
891 | &block_group->cluster_list) { | |
892 | cluster = list_entry(head, struct btrfs_free_cluster, | |
893 | block_group_list); | |
fa9c0d79 CM |
894 | |
895 | WARN_ON(cluster->block_group != block_group); | |
896 | __btrfs_return_cluster_to_free_space(block_group, cluster); | |
96303081 JB |
897 | if (need_resched()) { |
898 | spin_unlock(&block_group->tree_lock); | |
899 | cond_resched(); | |
900 | spin_lock(&block_group->tree_lock); | |
901 | } | |
fa9c0d79 CM |
902 | } |
903 | ||
96303081 JB |
904 | while ((node = rb_last(&block_group->free_space_offset)) != NULL) { |
905 | info = rb_entry(node, struct btrfs_free_space, offset_index); | |
0f9dd46c | 906 | unlink_free_space(block_group, info); |
96303081 JB |
907 | if (info->bitmap) |
908 | kfree(info->bitmap); | |
0f9dd46c JB |
909 | kfree(info); |
910 | if (need_resched()) { | |
6226cb0a | 911 | spin_unlock(&block_group->tree_lock); |
0f9dd46c | 912 | cond_resched(); |
6226cb0a | 913 | spin_lock(&block_group->tree_lock); |
0f9dd46c JB |
914 | } |
915 | } | |
96303081 | 916 | |
6226cb0a | 917 | spin_unlock(&block_group->tree_lock); |
0f9dd46c JB |
918 | } |
919 | ||
6226cb0a JB |
920 | u64 btrfs_find_space_for_alloc(struct btrfs_block_group_cache *block_group, |
921 | u64 offset, u64 bytes, u64 empty_size) | |
0f9dd46c | 922 | { |
6226cb0a | 923 | struct btrfs_free_space *entry = NULL; |
96303081 | 924 | u64 bytes_search = bytes + empty_size; |
6226cb0a | 925 | u64 ret = 0; |
0f9dd46c | 926 | |
6226cb0a | 927 | spin_lock(&block_group->tree_lock); |
96303081 | 928 | entry = find_free_space(block_group, &offset, &bytes_search, 0); |
6226cb0a | 929 | if (!entry) |
96303081 JB |
930 | goto out; |
931 | ||
932 | ret = offset; | |
933 | if (entry->bitmap) { | |
817d52f8 | 934 | bitmap_clear_bits(block_group, entry, offset, bytes); |
96303081 JB |
935 | if (!entry->bytes) { |
936 | unlink_free_space(block_group, entry); | |
937 | kfree(entry->bitmap); | |
938 | kfree(entry); | |
939 | block_group->total_bitmaps--; | |
940 | recalculate_thresholds(block_group); | |
941 | } | |
942 | } else { | |
6226cb0a | 943 | unlink_free_space(block_group, entry); |
6226cb0a JB |
944 | entry->offset += bytes; |
945 | entry->bytes -= bytes; | |
6226cb0a JB |
946 | if (!entry->bytes) |
947 | kfree(entry); | |
948 | else | |
949 | link_free_space(block_group, entry); | |
950 | } | |
0f9dd46c | 951 | |
96303081 JB |
952 | out: |
953 | spin_unlock(&block_group->tree_lock); | |
817d52f8 | 954 | |
0f9dd46c JB |
955 | return ret; |
956 | } | |
fa9c0d79 CM |
957 | |
958 | /* | |
959 | * given a cluster, put all of its extents back into the free space | |
960 | * cache. If a block group is passed, this function will only free | |
961 | * a cluster that belongs to the passed block group. | |
962 | * | |
963 | * Otherwise, it'll get a reference on the block group pointed to by the | |
964 | * cluster and remove the cluster from it. | |
965 | */ | |
966 | int btrfs_return_cluster_to_free_space( | |
967 | struct btrfs_block_group_cache *block_group, | |
968 | struct btrfs_free_cluster *cluster) | |
969 | { | |
970 | int ret; | |
971 | ||
972 | /* first, get a safe pointer to the block group */ | |
973 | spin_lock(&cluster->lock); | |
974 | if (!block_group) { | |
975 | block_group = cluster->block_group; | |
976 | if (!block_group) { | |
977 | spin_unlock(&cluster->lock); | |
978 | return 0; | |
979 | } | |
980 | } else if (cluster->block_group != block_group) { | |
981 | /* someone else has already freed it don't redo their work */ | |
982 | spin_unlock(&cluster->lock); | |
983 | return 0; | |
984 | } | |
985 | atomic_inc(&block_group->count); | |
986 | spin_unlock(&cluster->lock); | |
987 | ||
988 | /* now return any extents the cluster had on it */ | |
989 | spin_lock(&block_group->tree_lock); | |
990 | ret = __btrfs_return_cluster_to_free_space(block_group, cluster); | |
991 | spin_unlock(&block_group->tree_lock); | |
992 | ||
993 | /* finally drop our ref */ | |
994 | btrfs_put_block_group(block_group); | |
995 | return ret; | |
996 | } | |
997 | ||
96303081 JB |
998 | static u64 btrfs_alloc_from_bitmap(struct btrfs_block_group_cache *block_group, |
999 | struct btrfs_free_cluster *cluster, | |
1000 | u64 bytes, u64 min_start) | |
1001 | { | |
1002 | struct btrfs_free_space *entry; | |
1003 | int err; | |
1004 | u64 search_start = cluster->window_start; | |
1005 | u64 search_bytes = bytes; | |
1006 | u64 ret = 0; | |
1007 | ||
1008 | spin_lock(&block_group->tree_lock); | |
1009 | spin_lock(&cluster->lock); | |
1010 | ||
1011 | if (!cluster->points_to_bitmap) | |
1012 | goto out; | |
1013 | ||
1014 | if (cluster->block_group != block_group) | |
1015 | goto out; | |
1016 | ||
6606bb97 JB |
1017 | /* |
1018 | * search_start is the beginning of the bitmap, but at some point it may | |
1019 | * be a good idea to point to the actual start of the free area in the | |
1020 | * bitmap, so do the offset_to_bitmap trick anyway, and set bitmap_only | |
1021 | * to 1 to make sure we get the bitmap entry | |
1022 | */ | |
1023 | entry = tree_search_offset(block_group, | |
1024 | offset_to_bitmap(block_group, search_start), | |
1025 | 1, 0); | |
96303081 JB |
1026 | if (!entry || !entry->bitmap) |
1027 | goto out; | |
1028 | ||
1029 | search_start = min_start; | |
1030 | search_bytes = bytes; | |
1031 | ||
1032 | err = search_bitmap(block_group, entry, &search_start, | |
1033 | &search_bytes); | |
1034 | if (err) | |
1035 | goto out; | |
1036 | ||
1037 | ret = search_start; | |
817d52f8 | 1038 | bitmap_clear_bits(block_group, entry, ret, bytes); |
96303081 JB |
1039 | out: |
1040 | spin_unlock(&cluster->lock); | |
1041 | spin_unlock(&block_group->tree_lock); | |
1042 | ||
1043 | return ret; | |
1044 | } | |
1045 | ||
fa9c0d79 CM |
1046 | /* |
1047 | * given a cluster, try to allocate 'bytes' from it, returns 0 | |
1048 | * if it couldn't find anything suitably large, or a logical disk offset | |
1049 | * if things worked out | |
1050 | */ | |
1051 | u64 btrfs_alloc_from_cluster(struct btrfs_block_group_cache *block_group, | |
1052 | struct btrfs_free_cluster *cluster, u64 bytes, | |
1053 | u64 min_start) | |
1054 | { | |
1055 | struct btrfs_free_space *entry = NULL; | |
1056 | struct rb_node *node; | |
1057 | u64 ret = 0; | |
1058 | ||
96303081 JB |
1059 | if (cluster->points_to_bitmap) |
1060 | return btrfs_alloc_from_bitmap(block_group, cluster, bytes, | |
1061 | min_start); | |
1062 | ||
fa9c0d79 CM |
1063 | spin_lock(&cluster->lock); |
1064 | if (bytes > cluster->max_size) | |
1065 | goto out; | |
1066 | ||
1067 | if (cluster->block_group != block_group) | |
1068 | goto out; | |
1069 | ||
1070 | node = rb_first(&cluster->root); | |
1071 | if (!node) | |
1072 | goto out; | |
1073 | ||
1074 | entry = rb_entry(node, struct btrfs_free_space, offset_index); | |
1075 | ||
1076 | while(1) { | |
1077 | if (entry->bytes < bytes || entry->offset < min_start) { | |
1078 | struct rb_node *node; | |
1079 | ||
1080 | node = rb_next(&entry->offset_index); | |
1081 | if (!node) | |
1082 | break; | |
1083 | entry = rb_entry(node, struct btrfs_free_space, | |
1084 | offset_index); | |
1085 | continue; | |
1086 | } | |
1087 | ret = entry->offset; | |
1088 | ||
1089 | entry->offset += bytes; | |
1090 | entry->bytes -= bytes; | |
1091 | ||
1092 | if (entry->bytes == 0) { | |
1093 | rb_erase(&entry->offset_index, &cluster->root); | |
1094 | kfree(entry); | |
1095 | } | |
1096 | break; | |
1097 | } | |
1098 | out: | |
1099 | spin_unlock(&cluster->lock); | |
96303081 | 1100 | |
fa9c0d79 CM |
1101 | return ret; |
1102 | } | |
1103 | ||
96303081 JB |
1104 | static int btrfs_bitmap_cluster(struct btrfs_block_group_cache *block_group, |
1105 | struct btrfs_free_space *entry, | |
1106 | struct btrfs_free_cluster *cluster, | |
1107 | u64 offset, u64 bytes, u64 min_bytes) | |
1108 | { | |
1109 | unsigned long next_zero; | |
1110 | unsigned long i; | |
1111 | unsigned long search_bits; | |
1112 | unsigned long total_bits; | |
1113 | unsigned long found_bits; | |
1114 | unsigned long start = 0; | |
1115 | unsigned long total_found = 0; | |
1116 | bool found = false; | |
1117 | ||
1118 | i = offset_to_bit(entry->offset, block_group->sectorsize, | |
1119 | max_t(u64, offset, entry->offset)); | |
1120 | search_bits = bytes_to_bits(min_bytes, block_group->sectorsize); | |
1121 | total_bits = bytes_to_bits(bytes, block_group->sectorsize); | |
1122 | ||
1123 | again: | |
1124 | found_bits = 0; | |
1125 | for (i = find_next_bit(entry->bitmap, BITS_PER_BITMAP, i); | |
1126 | i < BITS_PER_BITMAP; | |
1127 | i = find_next_bit(entry->bitmap, BITS_PER_BITMAP, i + 1)) { | |
1128 | next_zero = find_next_zero_bit(entry->bitmap, | |
1129 | BITS_PER_BITMAP, i); | |
1130 | if (next_zero - i >= search_bits) { | |
1131 | found_bits = next_zero - i; | |
1132 | break; | |
1133 | } | |
1134 | i = next_zero; | |
1135 | } | |
1136 | ||
1137 | if (!found_bits) | |
1138 | return -1; | |
1139 | ||
1140 | if (!found) { | |
1141 | start = i; | |
1142 | found = true; | |
1143 | } | |
1144 | ||
1145 | total_found += found_bits; | |
1146 | ||
1147 | if (cluster->max_size < found_bits * block_group->sectorsize) | |
1148 | cluster->max_size = found_bits * block_group->sectorsize; | |
1149 | ||
1150 | if (total_found < total_bits) { | |
1151 | i = find_next_bit(entry->bitmap, BITS_PER_BITMAP, next_zero); | |
1152 | if (i - start > total_bits * 2) { | |
1153 | total_found = 0; | |
1154 | cluster->max_size = 0; | |
1155 | found = false; | |
1156 | } | |
1157 | goto again; | |
1158 | } | |
1159 | ||
1160 | cluster->window_start = start * block_group->sectorsize + | |
1161 | entry->offset; | |
1162 | cluster->points_to_bitmap = true; | |
1163 | ||
1164 | return 0; | |
1165 | } | |
1166 | ||
fa9c0d79 CM |
1167 | /* |
1168 | * here we try to find a cluster of blocks in a block group. The goal | |
1169 | * is to find at least bytes free and up to empty_size + bytes free. | |
1170 | * We might not find them all in one contiguous area. | |
1171 | * | |
1172 | * returns zero and sets up cluster if things worked out, otherwise | |
1173 | * it returns -enospc | |
1174 | */ | |
1175 | int btrfs_find_space_cluster(struct btrfs_trans_handle *trans, | |
451d7585 | 1176 | struct btrfs_root *root, |
fa9c0d79 CM |
1177 | struct btrfs_block_group_cache *block_group, |
1178 | struct btrfs_free_cluster *cluster, | |
1179 | u64 offset, u64 bytes, u64 empty_size) | |
1180 | { | |
1181 | struct btrfs_free_space *entry = NULL; | |
1182 | struct rb_node *node; | |
1183 | struct btrfs_free_space *next; | |
96303081 | 1184 | struct btrfs_free_space *last = NULL; |
fa9c0d79 CM |
1185 | u64 min_bytes; |
1186 | u64 window_start; | |
1187 | u64 window_free; | |
1188 | u64 max_extent = 0; | |
96303081 | 1189 | bool found_bitmap = false; |
fa9c0d79 CM |
1190 | int ret; |
1191 | ||
1192 | /* for metadata, allow allocates with more holes */ | |
451d7585 CM |
1193 | if (btrfs_test_opt(root, SSD_SPREAD)) { |
1194 | min_bytes = bytes + empty_size; | |
1195 | } else if (block_group->flags & BTRFS_BLOCK_GROUP_METADATA) { | |
fa9c0d79 CM |
1196 | /* |
1197 | * we want to do larger allocations when we are | |
1198 | * flushing out the delayed refs, it helps prevent | |
1199 | * making more work as we go along. | |
1200 | */ | |
1201 | if (trans->transaction->delayed_refs.flushing) | |
1202 | min_bytes = max(bytes, (bytes + empty_size) >> 1); | |
1203 | else | |
1204 | min_bytes = max(bytes, (bytes + empty_size) >> 4); | |
1205 | } else | |
1206 | min_bytes = max(bytes, (bytes + empty_size) >> 2); | |
1207 | ||
1208 | spin_lock(&block_group->tree_lock); | |
1209 | spin_lock(&cluster->lock); | |
1210 | ||
1211 | /* someone already found a cluster, hooray */ | |
1212 | if (cluster->block_group) { | |
1213 | ret = 0; | |
1214 | goto out; | |
1215 | } | |
1216 | again: | |
96303081 | 1217 | entry = tree_search_offset(block_group, offset, found_bitmap, 1); |
fa9c0d79 CM |
1218 | if (!entry) { |
1219 | ret = -ENOSPC; | |
1220 | goto out; | |
1221 | } | |
96303081 JB |
1222 | |
1223 | /* | |
1224 | * If found_bitmap is true, we exhausted our search for extent entries, | |
1225 | * and we just want to search all of the bitmaps that we can find, and | |
1226 | * ignore any extent entries we find. | |
1227 | */ | |
1228 | while (entry->bitmap || found_bitmap || | |
1229 | (!entry->bitmap && entry->bytes < min_bytes)) { | |
1230 | struct rb_node *node = rb_next(&entry->offset_index); | |
1231 | ||
1232 | if (entry->bitmap && entry->bytes > bytes + empty_size) { | |
1233 | ret = btrfs_bitmap_cluster(block_group, entry, cluster, | |
1234 | offset, bytes + empty_size, | |
1235 | min_bytes); | |
1236 | if (!ret) | |
1237 | goto got_it; | |
1238 | } | |
1239 | ||
1240 | if (!node) { | |
1241 | ret = -ENOSPC; | |
1242 | goto out; | |
1243 | } | |
1244 | entry = rb_entry(node, struct btrfs_free_space, offset_index); | |
1245 | } | |
1246 | ||
1247 | /* | |
1248 | * We already searched all the extent entries from the passed in offset | |
1249 | * to the end and didn't find enough space for the cluster, and we also | |
1250 | * didn't find any bitmaps that met our criteria, just go ahead and exit | |
1251 | */ | |
1252 | if (found_bitmap) { | |
1253 | ret = -ENOSPC; | |
1254 | goto out; | |
1255 | } | |
1256 | ||
1257 | cluster->points_to_bitmap = false; | |
fa9c0d79 CM |
1258 | window_start = entry->offset; |
1259 | window_free = entry->bytes; | |
1260 | last = entry; | |
1261 | max_extent = entry->bytes; | |
1262 | ||
96303081 | 1263 | while (1) { |
fa9c0d79 CM |
1264 | /* out window is just right, lets fill it */ |
1265 | if (window_free >= bytes + empty_size) | |
1266 | break; | |
1267 | ||
1268 | node = rb_next(&last->offset_index); | |
1269 | if (!node) { | |
96303081 JB |
1270 | if (found_bitmap) |
1271 | goto again; | |
fa9c0d79 CM |
1272 | ret = -ENOSPC; |
1273 | goto out; | |
1274 | } | |
1275 | next = rb_entry(node, struct btrfs_free_space, offset_index); | |
1276 | ||
96303081 JB |
1277 | /* |
1278 | * we found a bitmap, so if this search doesn't result in a | |
1279 | * cluster, we know to go and search again for the bitmaps and | |
1280 | * start looking for space there | |
1281 | */ | |
1282 | if (next->bitmap) { | |
1283 | if (!found_bitmap) | |
1284 | offset = next->offset; | |
1285 | found_bitmap = true; | |
1286 | last = next; | |
1287 | continue; | |
1288 | } | |
1289 | ||
fa9c0d79 CM |
1290 | /* |
1291 | * we haven't filled the empty size and the window is | |
1292 | * very large. reset and try again | |
1293 | */ | |
c6044801 CM |
1294 | if (next->offset - (last->offset + last->bytes) > 128 * 1024 || |
1295 | next->offset - window_start > (bytes + empty_size) * 2) { | |
fa9c0d79 CM |
1296 | entry = next; |
1297 | window_start = entry->offset; | |
1298 | window_free = entry->bytes; | |
1299 | last = entry; | |
01dea1ef | 1300 | max_extent = entry->bytes; |
fa9c0d79 CM |
1301 | } else { |
1302 | last = next; | |
1303 | window_free += next->bytes; | |
1304 | if (entry->bytes > max_extent) | |
1305 | max_extent = entry->bytes; | |
1306 | } | |
1307 | } | |
1308 | ||
1309 | cluster->window_start = entry->offset; | |
1310 | ||
1311 | /* | |
1312 | * now we've found our entries, pull them out of the free space | |
1313 | * cache and put them into the cluster rbtree | |
1314 | * | |
1315 | * The cluster includes an rbtree, but only uses the offset index | |
1316 | * of each free space cache entry. | |
1317 | */ | |
96303081 | 1318 | while (1) { |
fa9c0d79 | 1319 | node = rb_next(&entry->offset_index); |
96303081 JB |
1320 | if (entry->bitmap && node) { |
1321 | entry = rb_entry(node, struct btrfs_free_space, | |
1322 | offset_index); | |
1323 | continue; | |
1324 | } else if (entry->bitmap && !node) { | |
1325 | break; | |
1326 | } | |
1327 | ||
1328 | rb_erase(&entry->offset_index, &block_group->free_space_offset); | |
fa9c0d79 | 1329 | ret = tree_insert_offset(&cluster->root, entry->offset, |
96303081 | 1330 | &entry->offset_index, 0); |
fa9c0d79 CM |
1331 | BUG_ON(ret); |
1332 | ||
1333 | if (!node || entry == last) | |
1334 | break; | |
1335 | ||
1336 | entry = rb_entry(node, struct btrfs_free_space, offset_index); | |
1337 | } | |
96303081 | 1338 | |
fa9c0d79 | 1339 | cluster->max_size = max_extent; |
96303081 JB |
1340 | got_it: |
1341 | ret = 0; | |
fa9c0d79 CM |
1342 | atomic_inc(&block_group->count); |
1343 | list_add_tail(&cluster->block_group_list, &block_group->cluster_list); | |
1344 | cluster->block_group = block_group; | |
1345 | out: | |
1346 | spin_unlock(&cluster->lock); | |
1347 | spin_unlock(&block_group->tree_lock); | |
1348 | ||
1349 | return ret; | |
1350 | } | |
1351 | ||
1352 | /* | |
1353 | * simple code to zero out a cluster | |
1354 | */ | |
1355 | void btrfs_init_free_cluster(struct btrfs_free_cluster *cluster) | |
1356 | { | |
1357 | spin_lock_init(&cluster->lock); | |
1358 | spin_lock_init(&cluster->refill_lock); | |
6bef4d31 | 1359 | cluster->root = RB_ROOT; |
fa9c0d79 | 1360 | cluster->max_size = 0; |
96303081 | 1361 | cluster->points_to_bitmap = false; |
fa9c0d79 CM |
1362 | INIT_LIST_HEAD(&cluster->block_group_list); |
1363 | cluster->block_group = NULL; | |
1364 | } | |
1365 |