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