1
2
3
4
5
6#include <linux/kernel.h>
7#include <linux/bio.h>
8#include <linux/file.h>
9#include <linux/fs.h>
10#include <linux/pagemap.h>
11#include <linux/highmem.h>
12#include <linux/time.h>
13#include <linux/init.h>
14#include <linux/string.h>
15#include <linux/backing-dev.h>
16#include <linux/writeback.h>
17#include <linux/slab.h>
18#include <linux/sched/mm.h>
19#include <linux/log2.h>
20#include <crypto/hash.h>
21#include "misc.h"
22#include "ctree.h"
23#include "disk-io.h"
24#include "transaction.h"
25#include "btrfs_inode.h"
26#include "volumes.h"
27#include "ordered-data.h"
28#include "compression.h"
29#include "extent_io.h"
30#include "extent_map.h"
31
32int zlib_compress_pages(struct list_head *ws, struct address_space *mapping,
33 u64 start, struct page **pages, unsigned long *out_pages,
34 unsigned long *total_in, unsigned long *total_out);
35int zlib_decompress_bio(struct list_head *ws, struct compressed_bio *cb);
36int zlib_decompress(struct list_head *ws, unsigned char *data_in,
37 struct page *dest_page, unsigned long start_byte, size_t srclen,
38 size_t destlen);
39struct list_head *zlib_alloc_workspace(unsigned int level);
40void zlib_free_workspace(struct list_head *ws);
41struct list_head *zlib_get_workspace(unsigned int level);
42
43int lzo_compress_pages(struct list_head *ws, struct address_space *mapping,
44 u64 start, struct page **pages, unsigned long *out_pages,
45 unsigned long *total_in, unsigned long *total_out);
46int lzo_decompress_bio(struct list_head *ws, struct compressed_bio *cb);
47int lzo_decompress(struct list_head *ws, unsigned char *data_in,
48 struct page *dest_page, unsigned long start_byte, size_t srclen,
49 size_t destlen);
50struct list_head *lzo_alloc_workspace(unsigned int level);
51void lzo_free_workspace(struct list_head *ws);
52
53int zstd_compress_pages(struct list_head *ws, struct address_space *mapping,
54 u64 start, struct page **pages, unsigned long *out_pages,
55 unsigned long *total_in, unsigned long *total_out);
56int zstd_decompress_bio(struct list_head *ws, struct compressed_bio *cb);
57int zstd_decompress(struct list_head *ws, unsigned char *data_in,
58 struct page *dest_page, unsigned long start_byte, size_t srclen,
59 size_t destlen);
60void zstd_init_workspace_manager(void);
61void zstd_cleanup_workspace_manager(void);
62struct list_head *zstd_alloc_workspace(unsigned int level);
63void zstd_free_workspace(struct list_head *ws);
64struct list_head *zstd_get_workspace(unsigned int level);
65void zstd_put_workspace(struct list_head *ws);
66
67static const char* const btrfs_compress_types[] = { "", "zlib", "lzo", "zstd" };
68
69const char* btrfs_compress_type2str(enum btrfs_compression_type type)
70{
71 switch (type) {
72 case BTRFS_COMPRESS_ZLIB:
73 case BTRFS_COMPRESS_LZO:
74 case BTRFS_COMPRESS_ZSTD:
75 case BTRFS_COMPRESS_NONE:
76 return btrfs_compress_types[type];
77 default:
78 break;
79 }
80
81 return NULL;
82}
83
84bool btrfs_compress_is_valid_type(const char *str, size_t len)
85{
86 int i;
87
88 for (i = 1; i < ARRAY_SIZE(btrfs_compress_types); i++) {
89 size_t comp_len = strlen(btrfs_compress_types[i]);
90
91 if (len < comp_len)
92 continue;
93
94 if (!strncmp(btrfs_compress_types[i], str, comp_len))
95 return true;
96 }
97 return false;
98}
99
100static int compression_compress_pages(int type, struct list_head *ws,
101 struct address_space *mapping, u64 start, struct page **pages,
102 unsigned long *out_pages, unsigned long *total_in,
103 unsigned long *total_out)
104{
105 switch (type) {
106 case BTRFS_COMPRESS_ZLIB:
107 return zlib_compress_pages(ws, mapping, start, pages,
108 out_pages, total_in, total_out);
109 case BTRFS_COMPRESS_LZO:
110 return lzo_compress_pages(ws, mapping, start, pages,
111 out_pages, total_in, total_out);
112 case BTRFS_COMPRESS_ZSTD:
113 return zstd_compress_pages(ws, mapping, start, pages,
114 out_pages, total_in, total_out);
115 case BTRFS_COMPRESS_NONE:
116 default:
117
118
119
120
121
122 return -E2BIG;
123 }
124}
125
126static int compression_decompress_bio(int type, struct list_head *ws,
127 struct compressed_bio *cb)
128{
129 switch (type) {
130 case BTRFS_COMPRESS_ZLIB: return zlib_decompress_bio(ws, cb);
131 case BTRFS_COMPRESS_LZO: return lzo_decompress_bio(ws, cb);
132 case BTRFS_COMPRESS_ZSTD: return zstd_decompress_bio(ws, cb);
133 case BTRFS_COMPRESS_NONE:
134 default:
135
136
137
138
139 BUG();
140 }
141}
142
143static int compression_decompress(int type, struct list_head *ws,
144 unsigned char *data_in, struct page *dest_page,
145 unsigned long start_byte, size_t srclen, size_t destlen)
146{
147 switch (type) {
148 case BTRFS_COMPRESS_ZLIB: return zlib_decompress(ws, data_in, dest_page,
149 start_byte, srclen, destlen);
150 case BTRFS_COMPRESS_LZO: return lzo_decompress(ws, data_in, dest_page,
151 start_byte, srclen, destlen);
152 case BTRFS_COMPRESS_ZSTD: return zstd_decompress(ws, data_in, dest_page,
153 start_byte, srclen, destlen);
154 case BTRFS_COMPRESS_NONE:
155 default:
156
157
158
159
160 BUG();
161 }
162}
163
164static int btrfs_decompress_bio(struct compressed_bio *cb);
165
166static inline int compressed_bio_size(struct btrfs_fs_info *fs_info,
167 unsigned long disk_size)
168{
169 u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
170
171 return sizeof(struct compressed_bio) +
172 (DIV_ROUND_UP(disk_size, fs_info->sectorsize)) * csum_size;
173}
174
175static int check_compressed_csum(struct btrfs_inode *inode, struct bio *bio,
176 u64 disk_start)
177{
178 struct btrfs_fs_info *fs_info = inode->root->fs_info;
179 SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
180 const u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
181 struct page *page;
182 unsigned long i;
183 char *kaddr;
184 u8 csum[BTRFS_CSUM_SIZE];
185 struct compressed_bio *cb = bio->bi_private;
186 u8 *cb_sum = cb->sums;
187
188 if (inode->flags & BTRFS_INODE_NODATASUM)
189 return 0;
190
191 shash->tfm = fs_info->csum_shash;
192
193 for (i = 0; i < cb->nr_pages; i++) {
194 page = cb->compressed_pages[i];
195
196 kaddr = kmap_atomic(page);
197 crypto_shash_digest(shash, kaddr, PAGE_SIZE, csum);
198 kunmap_atomic(kaddr);
199
200 if (memcmp(&csum, cb_sum, csum_size)) {
201 btrfs_print_data_csum_error(inode, disk_start,
202 csum, cb_sum, cb->mirror_num);
203 if (btrfs_io_bio(bio)->device)
204 btrfs_dev_stat_inc_and_print(
205 btrfs_io_bio(bio)->device,
206 BTRFS_DEV_STAT_CORRUPTION_ERRS);
207 return -EIO;
208 }
209 cb_sum += csum_size;
210 }
211 return 0;
212}
213
214
215
216
217
218
219
220
221
222
223
224static void end_compressed_bio_read(struct bio *bio)
225{
226 struct compressed_bio *cb = bio->bi_private;
227 struct inode *inode;
228 struct page *page;
229 unsigned long index;
230 unsigned int mirror = btrfs_io_bio(bio)->mirror_num;
231 int ret = 0;
232
233 if (bio->bi_status)
234 cb->errors = 1;
235
236
237
238
239 if (!refcount_dec_and_test(&cb->pending_bios))
240 goto out;
241
242
243
244
245
246 btrfs_io_bio(cb->orig_bio)->mirror_num = mirror;
247 cb->mirror_num = mirror;
248
249
250
251
252
253 if (cb->errors == 1)
254 goto csum_failed;
255
256 inode = cb->inode;
257 ret = check_compressed_csum(BTRFS_I(inode), bio,
258 (u64)bio->bi_iter.bi_sector << 9);
259 if (ret)
260 goto csum_failed;
261
262
263
264
265 ret = btrfs_decompress_bio(cb);
266
267csum_failed:
268 if (ret)
269 cb->errors = 1;
270
271
272 index = 0;
273 for (index = 0; index < cb->nr_pages; index++) {
274 page = cb->compressed_pages[index];
275 page->mapping = NULL;
276 put_page(page);
277 }
278
279
280 if (cb->errors) {
281 bio_io_error(cb->orig_bio);
282 } else {
283 struct bio_vec *bvec;
284 struct bvec_iter_all iter_all;
285
286
287
288
289
290 ASSERT(!bio_flagged(bio, BIO_CLONED));
291 bio_for_each_segment_all(bvec, cb->orig_bio, iter_all)
292 SetPageChecked(bvec->bv_page);
293
294 bio_endio(cb->orig_bio);
295 }
296
297
298 kfree(cb->compressed_pages);
299 kfree(cb);
300out:
301 bio_put(bio);
302}
303
304
305
306
307
308static noinline void end_compressed_writeback(struct inode *inode,
309 const struct compressed_bio *cb)
310{
311 unsigned long index = cb->start >> PAGE_SHIFT;
312 unsigned long end_index = (cb->start + cb->len - 1) >> PAGE_SHIFT;
313 struct page *pages[16];
314 unsigned long nr_pages = end_index - index + 1;
315 int i;
316 int ret;
317
318 if (cb->errors)
319 mapping_set_error(inode->i_mapping, -EIO);
320
321 while (nr_pages > 0) {
322 ret = find_get_pages_contig(inode->i_mapping, index,
323 min_t(unsigned long,
324 nr_pages, ARRAY_SIZE(pages)), pages);
325 if (ret == 0) {
326 nr_pages -= 1;
327 index += 1;
328 continue;
329 }
330 for (i = 0; i < ret; i++) {
331 if (cb->errors)
332 SetPageError(pages[i]);
333 end_page_writeback(pages[i]);
334 put_page(pages[i]);
335 }
336 nr_pages -= ret;
337 index += ret;
338 }
339
340}
341
342
343
344
345
346
347
348
349
350static void end_compressed_bio_write(struct bio *bio)
351{
352 struct compressed_bio *cb = bio->bi_private;
353 struct inode *inode;
354 struct page *page;
355 unsigned long index;
356
357 if (bio->bi_status)
358 cb->errors = 1;
359
360
361
362
363 if (!refcount_dec_and_test(&cb->pending_bios))
364 goto out;
365
366
367
368
369 inode = cb->inode;
370 cb->compressed_pages[0]->mapping = cb->inode->i_mapping;
371 btrfs_writepage_endio_finish_ordered(cb->compressed_pages[0],
372 cb->start, cb->start + cb->len - 1,
373 bio->bi_status == BLK_STS_OK);
374 cb->compressed_pages[0]->mapping = NULL;
375
376 end_compressed_writeback(inode, cb);
377
378
379
380
381
382
383 index = 0;
384 for (index = 0; index < cb->nr_pages; index++) {
385 page = cb->compressed_pages[index];
386 page->mapping = NULL;
387 put_page(page);
388 }
389
390
391 kfree(cb->compressed_pages);
392 kfree(cb);
393out:
394 bio_put(bio);
395}
396
397
398
399
400
401
402
403
404
405
406blk_status_t btrfs_submit_compressed_write(struct btrfs_inode *inode, u64 start,
407 unsigned long len, u64 disk_start,
408 unsigned long compressed_len,
409 struct page **compressed_pages,
410 unsigned long nr_pages,
411 unsigned int write_flags,
412 struct cgroup_subsys_state *blkcg_css)
413{
414 struct btrfs_fs_info *fs_info = inode->root->fs_info;
415 struct bio *bio = NULL;
416 struct compressed_bio *cb;
417 unsigned long bytes_left;
418 int pg_index = 0;
419 struct page *page;
420 u64 first_byte = disk_start;
421 blk_status_t ret;
422 int skip_sum = inode->flags & BTRFS_INODE_NODATASUM;
423
424 WARN_ON(!PAGE_ALIGNED(start));
425 cb = kmalloc(compressed_bio_size(fs_info, compressed_len), GFP_NOFS);
426 if (!cb)
427 return BLK_STS_RESOURCE;
428 refcount_set(&cb->pending_bios, 0);
429 cb->errors = 0;
430 cb->inode = &inode->vfs_inode;
431 cb->start = start;
432 cb->len = len;
433 cb->mirror_num = 0;
434 cb->compressed_pages = compressed_pages;
435 cb->compressed_len = compressed_len;
436 cb->orig_bio = NULL;
437 cb->nr_pages = nr_pages;
438
439 bio = btrfs_bio_alloc(first_byte);
440 bio->bi_opf = REQ_OP_WRITE | write_flags;
441 bio->bi_private = cb;
442 bio->bi_end_io = end_compressed_bio_write;
443
444 if (blkcg_css) {
445 bio->bi_opf |= REQ_CGROUP_PUNT;
446 kthread_associate_blkcg(blkcg_css);
447 }
448 refcount_set(&cb->pending_bios, 1);
449
450
451 bytes_left = compressed_len;
452 for (pg_index = 0; pg_index < cb->nr_pages; pg_index++) {
453 int submit = 0;
454
455 page = compressed_pages[pg_index];
456 page->mapping = inode->vfs_inode.i_mapping;
457 if (bio->bi_iter.bi_size)
458 submit = btrfs_bio_fits_in_stripe(page, PAGE_SIZE, bio,
459 0);
460
461 page->mapping = NULL;
462 if (submit || bio_add_page(bio, page, PAGE_SIZE, 0) <
463 PAGE_SIZE) {
464
465
466
467
468
469
470 refcount_inc(&cb->pending_bios);
471 ret = btrfs_bio_wq_end_io(fs_info, bio,
472 BTRFS_WQ_ENDIO_DATA);
473 BUG_ON(ret);
474
475 if (!skip_sum) {
476 ret = btrfs_csum_one_bio(inode, bio, start, 1);
477 BUG_ON(ret);
478 }
479
480 ret = btrfs_map_bio(fs_info, bio, 0);
481 if (ret) {
482 bio->bi_status = ret;
483 bio_endio(bio);
484 }
485
486 bio = btrfs_bio_alloc(first_byte);
487 bio->bi_opf = REQ_OP_WRITE | write_flags;
488 bio->bi_private = cb;
489 bio->bi_end_io = end_compressed_bio_write;
490 if (blkcg_css)
491 bio->bi_opf |= REQ_CGROUP_PUNT;
492 bio_add_page(bio, page, PAGE_SIZE, 0);
493 }
494 if (bytes_left < PAGE_SIZE) {
495 btrfs_info(fs_info,
496 "bytes left %lu compress len %lu nr %lu",
497 bytes_left, cb->compressed_len, cb->nr_pages);
498 }
499 bytes_left -= PAGE_SIZE;
500 first_byte += PAGE_SIZE;
501 cond_resched();
502 }
503
504 ret = btrfs_bio_wq_end_io(fs_info, bio, BTRFS_WQ_ENDIO_DATA);
505 BUG_ON(ret);
506
507 if (!skip_sum) {
508 ret = btrfs_csum_one_bio(inode, bio, start, 1);
509 BUG_ON(ret);
510 }
511
512 ret = btrfs_map_bio(fs_info, bio, 0);
513 if (ret) {
514 bio->bi_status = ret;
515 bio_endio(bio);
516 }
517
518 if (blkcg_css)
519 kthread_associate_blkcg(NULL);
520
521 return 0;
522}
523
524static u64 bio_end_offset(struct bio *bio)
525{
526 struct bio_vec *last = bio_last_bvec_all(bio);
527
528 return page_offset(last->bv_page) + last->bv_len + last->bv_offset;
529}
530
531static noinline int add_ra_bio_pages(struct inode *inode,
532 u64 compressed_end,
533 struct compressed_bio *cb)
534{
535 unsigned long end_index;
536 unsigned long pg_index;
537 u64 last_offset;
538 u64 isize = i_size_read(inode);
539 int ret;
540 struct page *page;
541 unsigned long nr_pages = 0;
542 struct extent_map *em;
543 struct address_space *mapping = inode->i_mapping;
544 struct extent_map_tree *em_tree;
545 struct extent_io_tree *tree;
546 u64 end;
547 int misses = 0;
548
549 last_offset = bio_end_offset(cb->orig_bio);
550 em_tree = &BTRFS_I(inode)->extent_tree;
551 tree = &BTRFS_I(inode)->io_tree;
552
553 if (isize == 0)
554 return 0;
555
556 end_index = (i_size_read(inode) - 1) >> PAGE_SHIFT;
557
558 while (last_offset < compressed_end) {
559 pg_index = last_offset >> PAGE_SHIFT;
560
561 if (pg_index > end_index)
562 break;
563
564 page = xa_load(&mapping->i_pages, pg_index);
565 if (page && !xa_is_value(page)) {
566 misses++;
567 if (misses > 4)
568 break;
569 goto next;
570 }
571
572 page = __page_cache_alloc(mapping_gfp_constraint(mapping,
573 ~__GFP_FS));
574 if (!page)
575 break;
576
577 if (add_to_page_cache_lru(page, mapping, pg_index, GFP_NOFS)) {
578 put_page(page);
579 goto next;
580 }
581
582 end = last_offset + PAGE_SIZE - 1;
583
584
585
586
587
588 set_page_extent_mapped(page);
589 lock_extent(tree, last_offset, end);
590 read_lock(&em_tree->lock);
591 em = lookup_extent_mapping(em_tree, last_offset,
592 PAGE_SIZE);
593 read_unlock(&em_tree->lock);
594
595 if (!em || last_offset < em->start ||
596 (last_offset + PAGE_SIZE > extent_map_end(em)) ||
597 (em->block_start >> 9) != cb->orig_bio->bi_iter.bi_sector) {
598 free_extent_map(em);
599 unlock_extent(tree, last_offset, end);
600 unlock_page(page);
601 put_page(page);
602 break;
603 }
604 free_extent_map(em);
605
606 if (page->index == end_index) {
607 char *userpage;
608 size_t zero_offset = offset_in_page(isize);
609
610 if (zero_offset) {
611 int zeros;
612 zeros = PAGE_SIZE - zero_offset;
613 userpage = kmap_atomic(page);
614 memset(userpage + zero_offset, 0, zeros);
615 flush_dcache_page(page);
616 kunmap_atomic(userpage);
617 }
618 }
619
620 ret = bio_add_page(cb->orig_bio, page,
621 PAGE_SIZE, 0);
622
623 if (ret == PAGE_SIZE) {
624 nr_pages++;
625 put_page(page);
626 } else {
627 unlock_extent(tree, last_offset, end);
628 unlock_page(page);
629 put_page(page);
630 break;
631 }
632next:
633 last_offset += PAGE_SIZE;
634 }
635 return 0;
636}
637
638
639
640
641
642
643
644
645
646
647
648
649blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
650 int mirror_num, unsigned long bio_flags)
651{
652 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
653 struct extent_map_tree *em_tree;
654 struct compressed_bio *cb;
655 unsigned long compressed_len;
656 unsigned long nr_pages;
657 unsigned long pg_index;
658 struct page *page;
659 struct bio *comp_bio;
660 u64 cur_disk_byte = (u64)bio->bi_iter.bi_sector << 9;
661 u64 em_len;
662 u64 em_start;
663 struct extent_map *em;
664 blk_status_t ret = BLK_STS_RESOURCE;
665 int faili = 0;
666 const u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
667 u8 *sums;
668
669 em_tree = &BTRFS_I(inode)->extent_tree;
670
671
672 read_lock(&em_tree->lock);
673 em = lookup_extent_mapping(em_tree,
674 page_offset(bio_first_page_all(bio)),
675 PAGE_SIZE);
676 read_unlock(&em_tree->lock);
677 if (!em)
678 return BLK_STS_IOERR;
679
680 compressed_len = em->block_len;
681 cb = kmalloc(compressed_bio_size(fs_info, compressed_len), GFP_NOFS);
682 if (!cb)
683 goto out;
684
685 refcount_set(&cb->pending_bios, 0);
686 cb->errors = 0;
687 cb->inode = inode;
688 cb->mirror_num = mirror_num;
689 sums = cb->sums;
690
691 cb->start = em->orig_start;
692 em_len = em->len;
693 em_start = em->start;
694
695 free_extent_map(em);
696 em = NULL;
697
698 cb->len = bio->bi_iter.bi_size;
699 cb->compressed_len = compressed_len;
700 cb->compress_type = extent_compress_type(bio_flags);
701 cb->orig_bio = bio;
702
703 nr_pages = DIV_ROUND_UP(compressed_len, PAGE_SIZE);
704 cb->compressed_pages = kcalloc(nr_pages, sizeof(struct page *),
705 GFP_NOFS);
706 if (!cb->compressed_pages)
707 goto fail1;
708
709 for (pg_index = 0; pg_index < nr_pages; pg_index++) {
710 cb->compressed_pages[pg_index] = alloc_page(GFP_NOFS |
711 __GFP_HIGHMEM);
712 if (!cb->compressed_pages[pg_index]) {
713 faili = pg_index - 1;
714 ret = BLK_STS_RESOURCE;
715 goto fail2;
716 }
717 }
718 faili = nr_pages - 1;
719 cb->nr_pages = nr_pages;
720
721 add_ra_bio_pages(inode, em_start + em_len, cb);
722
723
724 cb->len = bio->bi_iter.bi_size;
725
726 comp_bio = btrfs_bio_alloc(cur_disk_byte);
727 comp_bio->bi_opf = REQ_OP_READ;
728 comp_bio->bi_private = cb;
729 comp_bio->bi_end_io = end_compressed_bio_read;
730 refcount_set(&cb->pending_bios, 1);
731
732 for (pg_index = 0; pg_index < nr_pages; pg_index++) {
733 int submit = 0;
734
735 page = cb->compressed_pages[pg_index];
736 page->mapping = inode->i_mapping;
737 page->index = em_start >> PAGE_SHIFT;
738
739 if (comp_bio->bi_iter.bi_size)
740 submit = btrfs_bio_fits_in_stripe(page, PAGE_SIZE,
741 comp_bio, 0);
742
743 page->mapping = NULL;
744 if (submit || bio_add_page(comp_bio, page, PAGE_SIZE, 0) <
745 PAGE_SIZE) {
746 unsigned int nr_sectors;
747
748 ret = btrfs_bio_wq_end_io(fs_info, comp_bio,
749 BTRFS_WQ_ENDIO_DATA);
750 BUG_ON(ret);
751
752
753
754
755
756
757
758 refcount_inc(&cb->pending_bios);
759
760 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) {
761 ret = btrfs_lookup_bio_sums(inode, comp_bio,
762 (u64)-1, sums);
763 BUG_ON(ret);
764 }
765
766 nr_sectors = DIV_ROUND_UP(comp_bio->bi_iter.bi_size,
767 fs_info->sectorsize);
768 sums += csum_size * nr_sectors;
769
770 ret = btrfs_map_bio(fs_info, comp_bio, mirror_num);
771 if (ret) {
772 comp_bio->bi_status = ret;
773 bio_endio(comp_bio);
774 }
775
776 comp_bio = btrfs_bio_alloc(cur_disk_byte);
777 comp_bio->bi_opf = REQ_OP_READ;
778 comp_bio->bi_private = cb;
779 comp_bio->bi_end_io = end_compressed_bio_read;
780
781 bio_add_page(comp_bio, page, PAGE_SIZE, 0);
782 }
783 cur_disk_byte += PAGE_SIZE;
784 }
785
786 ret = btrfs_bio_wq_end_io(fs_info, comp_bio, BTRFS_WQ_ENDIO_DATA);
787 BUG_ON(ret);
788
789 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) {
790 ret = btrfs_lookup_bio_sums(inode, comp_bio, (u64)-1, sums);
791 BUG_ON(ret);
792 }
793
794 ret = btrfs_map_bio(fs_info, comp_bio, mirror_num);
795 if (ret) {
796 comp_bio->bi_status = ret;
797 bio_endio(comp_bio);
798 }
799
800 return 0;
801
802fail2:
803 while (faili >= 0) {
804 __free_page(cb->compressed_pages[faili]);
805 faili--;
806 }
807
808 kfree(cb->compressed_pages);
809fail1:
810 kfree(cb);
811out:
812 free_extent_map(em);
813 return ret;
814}
815
816
817
818
819
820
821
822
823#define SAMPLING_READ_SIZE (16)
824#define SAMPLING_INTERVAL (256)
825
826
827
828
829
830
831#define BUCKET_SIZE (256)
832
833
834
835
836
837
838
839
840
841
842
843
844
845#define MAX_SAMPLE_SIZE (BTRFS_MAX_UNCOMPRESSED * \
846 SAMPLING_READ_SIZE / SAMPLING_INTERVAL)
847
848struct bucket_item {
849 u32 count;
850};
851
852struct heuristic_ws {
853
854 u8 *sample;
855 u32 sample_size;
856
857 struct bucket_item *bucket;
858
859 struct bucket_item *bucket_b;
860 struct list_head list;
861};
862
863static struct workspace_manager heuristic_wsm;
864
865static void free_heuristic_ws(struct list_head *ws)
866{
867 struct heuristic_ws *workspace;
868
869 workspace = list_entry(ws, struct heuristic_ws, list);
870
871 kvfree(workspace->sample);
872 kfree(workspace->bucket);
873 kfree(workspace->bucket_b);
874 kfree(workspace);
875}
876
877static struct list_head *alloc_heuristic_ws(unsigned int level)
878{
879 struct heuristic_ws *ws;
880
881 ws = kzalloc(sizeof(*ws), GFP_KERNEL);
882 if (!ws)
883 return ERR_PTR(-ENOMEM);
884
885 ws->sample = kvmalloc(MAX_SAMPLE_SIZE, GFP_KERNEL);
886 if (!ws->sample)
887 goto fail;
888
889 ws->bucket = kcalloc(BUCKET_SIZE, sizeof(*ws->bucket), GFP_KERNEL);
890 if (!ws->bucket)
891 goto fail;
892
893 ws->bucket_b = kcalloc(BUCKET_SIZE, sizeof(*ws->bucket_b), GFP_KERNEL);
894 if (!ws->bucket_b)
895 goto fail;
896
897 INIT_LIST_HEAD(&ws->list);
898 return &ws->list;
899fail:
900 free_heuristic_ws(&ws->list);
901 return ERR_PTR(-ENOMEM);
902}
903
904const struct btrfs_compress_op btrfs_heuristic_compress = {
905 .workspace_manager = &heuristic_wsm,
906};
907
908static const struct btrfs_compress_op * const btrfs_compress_op[] = {
909
910 &btrfs_heuristic_compress,
911 &btrfs_zlib_compress,
912 &btrfs_lzo_compress,
913 &btrfs_zstd_compress,
914};
915
916static struct list_head *alloc_workspace(int type, unsigned int level)
917{
918 switch (type) {
919 case BTRFS_COMPRESS_NONE: return alloc_heuristic_ws(level);
920 case BTRFS_COMPRESS_ZLIB: return zlib_alloc_workspace(level);
921 case BTRFS_COMPRESS_LZO: return lzo_alloc_workspace(level);
922 case BTRFS_COMPRESS_ZSTD: return zstd_alloc_workspace(level);
923 default:
924
925
926
927
928 BUG();
929 }
930}
931
932static void free_workspace(int type, struct list_head *ws)
933{
934 switch (type) {
935 case BTRFS_COMPRESS_NONE: return free_heuristic_ws(ws);
936 case BTRFS_COMPRESS_ZLIB: return zlib_free_workspace(ws);
937 case BTRFS_COMPRESS_LZO: return lzo_free_workspace(ws);
938 case BTRFS_COMPRESS_ZSTD: return zstd_free_workspace(ws);
939 default:
940
941
942
943
944 BUG();
945 }
946}
947
948static void btrfs_init_workspace_manager(int type)
949{
950 struct workspace_manager *wsm;
951 struct list_head *workspace;
952
953 wsm = btrfs_compress_op[type]->workspace_manager;
954 INIT_LIST_HEAD(&wsm->idle_ws);
955 spin_lock_init(&wsm->ws_lock);
956 atomic_set(&wsm->total_ws, 0);
957 init_waitqueue_head(&wsm->ws_wait);
958
959
960
961
962
963 workspace = alloc_workspace(type, 0);
964 if (IS_ERR(workspace)) {
965 pr_warn(
966 "BTRFS: cannot preallocate compression workspace, will try later\n");
967 } else {
968 atomic_set(&wsm->total_ws, 1);
969 wsm->free_ws = 1;
970 list_add(workspace, &wsm->idle_ws);
971 }
972}
973
974static void btrfs_cleanup_workspace_manager(int type)
975{
976 struct workspace_manager *wsman;
977 struct list_head *ws;
978
979 wsman = btrfs_compress_op[type]->workspace_manager;
980 while (!list_empty(&wsman->idle_ws)) {
981 ws = wsman->idle_ws.next;
982 list_del(ws);
983 free_workspace(type, ws);
984 atomic_dec(&wsman->total_ws);
985 }
986}
987
988
989
990
991
992
993
994struct list_head *btrfs_get_workspace(int type, unsigned int level)
995{
996 struct workspace_manager *wsm;
997 struct list_head *workspace;
998 int cpus = num_online_cpus();
999 unsigned nofs_flag;
1000 struct list_head *idle_ws;
1001 spinlock_t *ws_lock;
1002 atomic_t *total_ws;
1003 wait_queue_head_t *ws_wait;
1004 int *free_ws;
1005
1006 wsm = btrfs_compress_op[type]->workspace_manager;
1007 idle_ws = &wsm->idle_ws;
1008 ws_lock = &wsm->ws_lock;
1009 total_ws = &wsm->total_ws;
1010 ws_wait = &wsm->ws_wait;
1011 free_ws = &wsm->free_ws;
1012
1013again:
1014 spin_lock(ws_lock);
1015 if (!list_empty(idle_ws)) {
1016 workspace = idle_ws->next;
1017 list_del(workspace);
1018 (*free_ws)--;
1019 spin_unlock(ws_lock);
1020 return workspace;
1021
1022 }
1023 if (atomic_read(total_ws) > cpus) {
1024 DEFINE_WAIT(wait);
1025
1026 spin_unlock(ws_lock);
1027 prepare_to_wait(ws_wait, &wait, TASK_UNINTERRUPTIBLE);
1028 if (atomic_read(total_ws) > cpus && !*free_ws)
1029 schedule();
1030 finish_wait(ws_wait, &wait);
1031 goto again;
1032 }
1033 atomic_inc(total_ws);
1034 spin_unlock(ws_lock);
1035
1036
1037
1038
1039
1040
1041 nofs_flag = memalloc_nofs_save();
1042 workspace = alloc_workspace(type, level);
1043 memalloc_nofs_restore(nofs_flag);
1044
1045 if (IS_ERR(workspace)) {
1046 atomic_dec(total_ws);
1047 wake_up(ws_wait);
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059 if (atomic_read(total_ws) == 0) {
1060 static DEFINE_RATELIMIT_STATE(_rs,
1061 60 * HZ,
1062 1);
1063
1064 if (__ratelimit(&_rs)) {
1065 pr_warn("BTRFS: no compression workspaces, low memory, retrying\n");
1066 }
1067 }
1068 goto again;
1069 }
1070 return workspace;
1071}
1072
1073static struct list_head *get_workspace(int type, int level)
1074{
1075 switch (type) {
1076 case BTRFS_COMPRESS_NONE: return btrfs_get_workspace(type, level);
1077 case BTRFS_COMPRESS_ZLIB: return zlib_get_workspace(level);
1078 case BTRFS_COMPRESS_LZO: return btrfs_get_workspace(type, level);
1079 case BTRFS_COMPRESS_ZSTD: return zstd_get_workspace(level);
1080 default:
1081
1082
1083
1084
1085 BUG();
1086 }
1087}
1088
1089
1090
1091
1092
1093void btrfs_put_workspace(int type, struct list_head *ws)
1094{
1095 struct workspace_manager *wsm;
1096 struct list_head *idle_ws;
1097 spinlock_t *ws_lock;
1098 atomic_t *total_ws;
1099 wait_queue_head_t *ws_wait;
1100 int *free_ws;
1101
1102 wsm = btrfs_compress_op[type]->workspace_manager;
1103 idle_ws = &wsm->idle_ws;
1104 ws_lock = &wsm->ws_lock;
1105 total_ws = &wsm->total_ws;
1106 ws_wait = &wsm->ws_wait;
1107 free_ws = &wsm->free_ws;
1108
1109 spin_lock(ws_lock);
1110 if (*free_ws <= num_online_cpus()) {
1111 list_add(ws, idle_ws);
1112 (*free_ws)++;
1113 spin_unlock(ws_lock);
1114 goto wake;
1115 }
1116 spin_unlock(ws_lock);
1117
1118 free_workspace(type, ws);
1119 atomic_dec(total_ws);
1120wake:
1121 cond_wake_up(ws_wait);
1122}
1123
1124static void put_workspace(int type, struct list_head *ws)
1125{
1126 switch (type) {
1127 case BTRFS_COMPRESS_NONE: return btrfs_put_workspace(type, ws);
1128 case BTRFS_COMPRESS_ZLIB: return btrfs_put_workspace(type, ws);
1129 case BTRFS_COMPRESS_LZO: return btrfs_put_workspace(type, ws);
1130 case BTRFS_COMPRESS_ZSTD: return zstd_put_workspace(ws);
1131 default:
1132
1133
1134
1135
1136 BUG();
1137 }
1138}
1139
1140
1141
1142
1143
1144static unsigned int btrfs_compress_set_level(int type, unsigned level)
1145{
1146 const struct btrfs_compress_op *ops = btrfs_compress_op[type];
1147
1148 if (level == 0)
1149 level = ops->default_level;
1150 else
1151 level = min(level, ops->max_level);
1152
1153 return level;
1154}
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179int btrfs_compress_pages(unsigned int type_level, struct address_space *mapping,
1180 u64 start, struct page **pages,
1181 unsigned long *out_pages,
1182 unsigned long *total_in,
1183 unsigned long *total_out)
1184{
1185 int type = btrfs_compress_type(type_level);
1186 int level = btrfs_compress_level(type_level);
1187 struct list_head *workspace;
1188 int ret;
1189
1190 level = btrfs_compress_set_level(type, level);
1191 workspace = get_workspace(type, level);
1192 ret = compression_compress_pages(type, workspace, mapping, start, pages,
1193 out_pages, total_in, total_out);
1194 put_workspace(type, workspace);
1195 return ret;
1196}
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212static int btrfs_decompress_bio(struct compressed_bio *cb)
1213{
1214 struct list_head *workspace;
1215 int ret;
1216 int type = cb->compress_type;
1217
1218 workspace = get_workspace(type, 0);
1219 ret = compression_decompress_bio(type, workspace, cb);
1220 put_workspace(type, workspace);
1221
1222 return ret;
1223}
1224
1225
1226
1227
1228
1229
1230int btrfs_decompress(int type, unsigned char *data_in, struct page *dest_page,
1231 unsigned long start_byte, size_t srclen, size_t destlen)
1232{
1233 struct list_head *workspace;
1234 int ret;
1235
1236 workspace = get_workspace(type, 0);
1237 ret = compression_decompress(type, workspace, data_in, dest_page,
1238 start_byte, srclen, destlen);
1239 put_workspace(type, workspace);
1240
1241 return ret;
1242}
1243
1244void __init btrfs_init_compress(void)
1245{
1246 btrfs_init_workspace_manager(BTRFS_COMPRESS_NONE);
1247 btrfs_init_workspace_manager(BTRFS_COMPRESS_ZLIB);
1248 btrfs_init_workspace_manager(BTRFS_COMPRESS_LZO);
1249 zstd_init_workspace_manager();
1250}
1251
1252void __cold btrfs_exit_compress(void)
1253{
1254 btrfs_cleanup_workspace_manager(BTRFS_COMPRESS_NONE);
1255 btrfs_cleanup_workspace_manager(BTRFS_COMPRESS_ZLIB);
1256 btrfs_cleanup_workspace_manager(BTRFS_COMPRESS_LZO);
1257 zstd_cleanup_workspace_manager();
1258}
1259
1260
1261
1262
1263
1264
1265
1266
1267int btrfs_decompress_buf2page(const char *buf, unsigned long buf_start,
1268 unsigned long total_out, u64 disk_start,
1269 struct bio *bio)
1270{
1271 unsigned long buf_offset;
1272 unsigned long current_buf_start;
1273 unsigned long start_byte;
1274 unsigned long prev_start_byte;
1275 unsigned long working_bytes = total_out - buf_start;
1276 unsigned long bytes;
1277 char *kaddr;
1278 struct bio_vec bvec = bio_iter_iovec(bio, bio->bi_iter);
1279
1280
1281
1282
1283
1284 start_byte = page_offset(bvec.bv_page) - disk_start;
1285
1286
1287 if (total_out <= start_byte)
1288 return 1;
1289
1290
1291
1292
1293
1294 if (total_out > start_byte && buf_start < start_byte) {
1295 buf_offset = start_byte - buf_start;
1296 working_bytes -= buf_offset;
1297 } else {
1298 buf_offset = 0;
1299 }
1300 current_buf_start = buf_start;
1301
1302
1303 while (working_bytes > 0) {
1304 bytes = min_t(unsigned long, bvec.bv_len,
1305 PAGE_SIZE - (buf_offset % PAGE_SIZE));
1306 bytes = min(bytes, working_bytes);
1307
1308 kaddr = kmap_atomic(bvec.bv_page);
1309 memcpy(kaddr + bvec.bv_offset, buf + buf_offset, bytes);
1310 kunmap_atomic(kaddr);
1311 flush_dcache_page(bvec.bv_page);
1312
1313 buf_offset += bytes;
1314 working_bytes -= bytes;
1315 current_buf_start += bytes;
1316
1317
1318 bio_advance(bio, bytes);
1319 if (!bio->bi_iter.bi_size)
1320 return 0;
1321 bvec = bio_iter_iovec(bio, bio->bi_iter);
1322 prev_start_byte = start_byte;
1323 start_byte = page_offset(bvec.bv_page) - disk_start;
1324
1325
1326
1327
1328
1329
1330
1331 if (start_byte != prev_start_byte) {
1332
1333
1334
1335
1336 if (total_out <= start_byte)
1337 return 1;
1338
1339
1340
1341
1342
1343
1344 if (total_out > start_byte &&
1345 current_buf_start < start_byte) {
1346 buf_offset = start_byte - buf_start;
1347 working_bytes = total_out - start_byte;
1348 current_buf_start = buf_start + buf_offset;
1349 }
1350 }
1351 }
1352
1353 return 1;
1354}
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373#define ENTROPY_LVL_ACEPTABLE (65)
1374#define ENTROPY_LVL_HIGH (80)
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386static inline u32 ilog2_w(u64 n)
1387{
1388 return ilog2(n * n * n * n);
1389}
1390
1391static u32 shannon_entropy(struct heuristic_ws *ws)
1392{
1393 const u32 entropy_max = 8 * ilog2_w(2);
1394 u32 entropy_sum = 0;
1395 u32 p, p_base, sz_base;
1396 u32 i;
1397
1398 sz_base = ilog2_w(ws->sample_size);
1399 for (i = 0; i < BUCKET_SIZE && ws->bucket[i].count > 0; i++) {
1400 p = ws->bucket[i].count;
1401 p_base = ilog2_w(p);
1402 entropy_sum += p * (sz_base - p_base);
1403 }
1404
1405 entropy_sum /= ws->sample_size;
1406 return entropy_sum * 100 / entropy_max;
1407}
1408
1409#define RADIX_BASE 4U
1410#define COUNTERS_SIZE (1U << RADIX_BASE)
1411
1412static u8 get4bits(u64 num, int shift) {
1413 u8 low4bits;
1414
1415 num >>= shift;
1416
1417 low4bits = (COUNTERS_SIZE - 1) - (num % COUNTERS_SIZE);
1418 return low4bits;
1419}
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430static void radix_sort(struct bucket_item *array, struct bucket_item *array_buf,
1431 int num)
1432{
1433 u64 max_num;
1434 u64 buf_num;
1435 u32 counters[COUNTERS_SIZE];
1436 u32 new_addr;
1437 u32 addr;
1438 int bitlen;
1439 int shift;
1440 int i;
1441
1442
1443
1444
1445
1446 max_num = array[0].count;
1447 for (i = 1; i < num; i++) {
1448 buf_num = array[i].count;
1449 if (buf_num > max_num)
1450 max_num = buf_num;
1451 }
1452
1453 buf_num = ilog2(max_num);
1454 bitlen = ALIGN(buf_num, RADIX_BASE * 2);
1455
1456 shift = 0;
1457 while (shift < bitlen) {
1458 memset(counters, 0, sizeof(counters));
1459
1460 for (i = 0; i < num; i++) {
1461 buf_num = array[i].count;
1462 addr = get4bits(buf_num, shift);
1463 counters[addr]++;
1464 }
1465
1466 for (i = 1; i < COUNTERS_SIZE; i++)
1467 counters[i] += counters[i - 1];
1468
1469 for (i = num - 1; i >= 0; i--) {
1470 buf_num = array[i].count;
1471 addr = get4bits(buf_num, shift);
1472 counters[addr]--;
1473 new_addr = counters[addr];
1474 array_buf[new_addr] = array[i];
1475 }
1476
1477 shift += RADIX_BASE;
1478
1479
1480
1481
1482
1483
1484
1485 memset(counters, 0, sizeof(counters));
1486
1487 for (i = 0; i < num; i ++) {
1488 buf_num = array_buf[i].count;
1489 addr = get4bits(buf_num, shift);
1490 counters[addr]++;
1491 }
1492
1493 for (i = 1; i < COUNTERS_SIZE; i++)
1494 counters[i] += counters[i - 1];
1495
1496 for (i = num - 1; i >= 0; i--) {
1497 buf_num = array_buf[i].count;
1498 addr = get4bits(buf_num, shift);
1499 counters[addr]--;
1500 new_addr = counters[addr];
1501 array[new_addr] = array_buf[i];
1502 }
1503
1504 shift += RADIX_BASE;
1505 }
1506}
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524#define BYTE_CORE_SET_LOW (64)
1525#define BYTE_CORE_SET_HIGH (200)
1526
1527static int byte_core_set_size(struct heuristic_ws *ws)
1528{
1529 u32 i;
1530 u32 coreset_sum = 0;
1531 const u32 core_set_threshold = ws->sample_size * 90 / 100;
1532 struct bucket_item *bucket = ws->bucket;
1533
1534
1535 radix_sort(ws->bucket, ws->bucket_b, BUCKET_SIZE);
1536
1537 for (i = 0; i < BYTE_CORE_SET_LOW; i++)
1538 coreset_sum += bucket[i].count;
1539
1540 if (coreset_sum > core_set_threshold)
1541 return i;
1542
1543 for (; i < BYTE_CORE_SET_HIGH && bucket[i].count > 0; i++) {
1544 coreset_sum += bucket[i].count;
1545 if (coreset_sum > core_set_threshold)
1546 break;
1547 }
1548
1549 return i;
1550}
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563#define BYTE_SET_THRESHOLD (64)
1564
1565static u32 byte_set_size(const struct heuristic_ws *ws)
1566{
1567 u32 i;
1568 u32 byte_set_size = 0;
1569
1570 for (i = 0; i < BYTE_SET_THRESHOLD; i++) {
1571 if (ws->bucket[i].count > 0)
1572 byte_set_size++;
1573 }
1574
1575
1576
1577
1578
1579
1580 for (; i < BUCKET_SIZE; i++) {
1581 if (ws->bucket[i].count > 0) {
1582 byte_set_size++;
1583 if (byte_set_size > BYTE_SET_THRESHOLD)
1584 return byte_set_size;
1585 }
1586 }
1587
1588 return byte_set_size;
1589}
1590
1591static bool sample_repeated_patterns(struct heuristic_ws *ws)
1592{
1593 const u32 half_of_sample = ws->sample_size / 2;
1594 const u8 *data = ws->sample;
1595
1596 return memcmp(&data[0], &data[half_of_sample], half_of_sample) == 0;
1597}
1598
1599static void heuristic_collect_sample(struct inode *inode, u64 start, u64 end,
1600 struct heuristic_ws *ws)
1601{
1602 struct page *page;
1603 u64 index, index_end;
1604 u32 i, curr_sample_pos;
1605 u8 *in_data;
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616 if (end - start > BTRFS_MAX_UNCOMPRESSED)
1617 end = start + BTRFS_MAX_UNCOMPRESSED;
1618
1619 index = start >> PAGE_SHIFT;
1620 index_end = end >> PAGE_SHIFT;
1621
1622
1623 if (!IS_ALIGNED(end, PAGE_SIZE))
1624 index_end++;
1625
1626 curr_sample_pos = 0;
1627 while (index < index_end) {
1628 page = find_get_page(inode->i_mapping, index);
1629 in_data = kmap(page);
1630
1631 i = start % PAGE_SIZE;
1632 while (i < PAGE_SIZE - SAMPLING_READ_SIZE) {
1633
1634 if (start > end - SAMPLING_READ_SIZE)
1635 break;
1636 memcpy(&ws->sample[curr_sample_pos], &in_data[i],
1637 SAMPLING_READ_SIZE);
1638 i += SAMPLING_INTERVAL;
1639 start += SAMPLING_INTERVAL;
1640 curr_sample_pos += SAMPLING_READ_SIZE;
1641 }
1642 kunmap(page);
1643 put_page(page);
1644
1645 index++;
1646 }
1647
1648 ws->sample_size = curr_sample_pos;
1649}
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666int btrfs_compress_heuristic(struct inode *inode, u64 start, u64 end)
1667{
1668 struct list_head *ws_list = get_workspace(0, 0);
1669 struct heuristic_ws *ws;
1670 u32 i;
1671 u8 byte;
1672 int ret = 0;
1673
1674 ws = list_entry(ws_list, struct heuristic_ws, list);
1675
1676 heuristic_collect_sample(inode, start, end, ws);
1677
1678 if (sample_repeated_patterns(ws)) {
1679 ret = 1;
1680 goto out;
1681 }
1682
1683 memset(ws->bucket, 0, sizeof(*ws->bucket)*BUCKET_SIZE);
1684
1685 for (i = 0; i < ws->sample_size; i++) {
1686 byte = ws->sample[i];
1687 ws->bucket[byte].count++;
1688 }
1689
1690 i = byte_set_size(ws);
1691 if (i < BYTE_SET_THRESHOLD) {
1692 ret = 2;
1693 goto out;
1694 }
1695
1696 i = byte_core_set_size(ws);
1697 if (i <= BYTE_CORE_SET_LOW) {
1698 ret = 3;
1699 goto out;
1700 }
1701
1702 if (i >= BYTE_CORE_SET_HIGH) {
1703 ret = 0;
1704 goto out;
1705 }
1706
1707 i = shannon_entropy(ws);
1708 if (i <= ENTROPY_LVL_ACEPTABLE) {
1709 ret = 4;
1710 goto out;
1711 }
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728 if (i < ENTROPY_LVL_HIGH) {
1729 ret = 5;
1730 goto out;
1731 } else {
1732 ret = 0;
1733 goto out;
1734 }
1735
1736out:
1737 put_workspace(0, ws_list);
1738 return ret;
1739}
1740
1741
1742
1743
1744
1745unsigned int btrfs_compress_str2level(unsigned int type, const char *str)
1746{
1747 unsigned int level = 0;
1748 int ret;
1749
1750 if (!type)
1751 return 0;
1752
1753 if (str[0] == ':') {
1754 ret = kstrtouint(str + 1, 10, &level);
1755 if (ret)
1756 level = 0;
1757 }
1758
1759 level = btrfs_compress_set_level(type, level);
1760
1761 return level;
1762}
1763