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c1d7c514 | 1 | // SPDX-License-Identifier: GPL-2.0 |
c8b97818 CM |
2 | /* |
3 | * Copyright (C) 2008 Oracle. All rights reserved. | |
c8b97818 CM |
4 | */ |
5 | ||
6 | #include <linux/kernel.h> | |
7 | #include <linux/bio.h> | |
c8b97818 CM |
8 | #include <linux/file.h> |
9 | #include <linux/fs.h> | |
10 | #include <linux/pagemap.h> | |
a75b81c3 | 11 | #include <linux/pagevec.h> |
c8b97818 | 12 | #include <linux/highmem.h> |
e41d12f5 | 13 | #include <linux/kthread.h> |
c8b97818 CM |
14 | #include <linux/time.h> |
15 | #include <linux/init.h> | |
16 | #include <linux/string.h> | |
c8b97818 | 17 | #include <linux/backing-dev.h> |
c8b97818 | 18 | #include <linux/writeback.h> |
4088a47e | 19 | #include <linux/psi.h> |
5a0e3ad6 | 20 | #include <linux/slab.h> |
fe308533 | 21 | #include <linux/sched/mm.h> |
19562430 | 22 | #include <linux/log2.h> |
d5178578 | 23 | #include <crypto/hash.h> |
602cbe91 | 24 | #include "misc.h" |
c8b97818 | 25 | #include "ctree.h" |
ec8eb376 | 26 | #include "fs.h" |
c8b97818 CM |
27 | #include "disk-io.h" |
28 | #include "transaction.h" | |
29 | #include "btrfs_inode.h" | |
103c1972 | 30 | #include "bio.h" |
c8b97818 | 31 | #include "ordered-data.h" |
c8b97818 CM |
32 | #include "compression.h" |
33 | #include "extent_io.h" | |
34 | #include "extent_map.h" | |
6a404910 | 35 | #include "subpage.h" |
764c7c9a | 36 | #include "zoned.h" |
7c8ede16 | 37 | #include "file-item.h" |
7f0add25 | 38 | #include "super.h" |
c8b97818 | 39 | |
544fe4a9 CH |
40 | struct bio_set btrfs_compressed_bioset; |
41 | ||
e128f9c3 DS |
42 | static const char* const btrfs_compress_types[] = { "", "zlib", "lzo", "zstd" }; |
43 | ||
44 | const char* btrfs_compress_type2str(enum btrfs_compression_type type) | |
45 | { | |
46 | switch (type) { | |
47 | case BTRFS_COMPRESS_ZLIB: | |
48 | case BTRFS_COMPRESS_LZO: | |
49 | case BTRFS_COMPRESS_ZSTD: | |
50 | case BTRFS_COMPRESS_NONE: | |
51 | return btrfs_compress_types[type]; | |
ce96b7ff CX |
52 | default: |
53 | break; | |
e128f9c3 DS |
54 | } |
55 | ||
56 | return NULL; | |
57 | } | |
58 | ||
544fe4a9 CH |
59 | static inline struct compressed_bio *to_compressed_bio(struct btrfs_bio *bbio) |
60 | { | |
61 | return container_of(bbio, struct compressed_bio, bbio); | |
62 | } | |
63 | ||
64 | static struct compressed_bio *alloc_compressed_bio(struct btrfs_inode *inode, | |
65 | u64 start, blk_opf_t op, | |
66 | btrfs_bio_end_io_t end_io) | |
67 | { | |
68 | struct btrfs_bio *bbio; | |
69 | ||
70 | bbio = btrfs_bio(bio_alloc_bioset(NULL, BTRFS_MAX_COMPRESSED_PAGES, op, | |
71 | GFP_NOFS, &btrfs_compressed_bioset)); | |
4317ff00 QW |
72 | btrfs_bio_init(bbio, inode->root->fs_info, end_io, NULL); |
73 | bbio->inode = inode; | |
544fe4a9 CH |
74 | bbio->file_offset = start; |
75 | return to_compressed_bio(bbio); | |
76 | } | |
77 | ||
aa53e3bf JT |
78 | bool btrfs_compress_is_valid_type(const char *str, size_t len) |
79 | { | |
80 | int i; | |
81 | ||
82 | for (i = 1; i < ARRAY_SIZE(btrfs_compress_types); i++) { | |
83 | size_t comp_len = strlen(btrfs_compress_types[i]); | |
84 | ||
85 | if (len < comp_len) | |
86 | continue; | |
87 | ||
88 | if (!strncmp(btrfs_compress_types[i], str, comp_len)) | |
89 | return true; | |
90 | } | |
91 | return false; | |
92 | } | |
93 | ||
1e4eb746 DS |
94 | static int compression_compress_pages(int type, struct list_head *ws, |
95 | struct address_space *mapping, u64 start, struct page **pages, | |
96 | unsigned long *out_pages, unsigned long *total_in, | |
97 | unsigned long *total_out) | |
98 | { | |
99 | switch (type) { | |
100 | case BTRFS_COMPRESS_ZLIB: | |
101 | return zlib_compress_pages(ws, mapping, start, pages, | |
102 | out_pages, total_in, total_out); | |
103 | case BTRFS_COMPRESS_LZO: | |
104 | return lzo_compress_pages(ws, mapping, start, pages, | |
105 | out_pages, total_in, total_out); | |
106 | case BTRFS_COMPRESS_ZSTD: | |
107 | return zstd_compress_pages(ws, mapping, start, pages, | |
108 | out_pages, total_in, total_out); | |
109 | case BTRFS_COMPRESS_NONE: | |
110 | default: | |
111 | /* | |
1d8ba9e7 QW |
112 | * This can happen when compression races with remount setting |
113 | * it to 'no compress', while caller doesn't call | |
114 | * inode_need_compress() to check if we really need to | |
115 | * compress. | |
116 | * | |
117 | * Not a big deal, just need to inform caller that we | |
118 | * haven't allocated any pages yet. | |
1e4eb746 | 119 | */ |
1d8ba9e7 | 120 | *out_pages = 0; |
1e4eb746 DS |
121 | return -E2BIG; |
122 | } | |
123 | } | |
124 | ||
4a9e803e SY |
125 | static int compression_decompress_bio(struct list_head *ws, |
126 | struct compressed_bio *cb) | |
1e4eb746 | 127 | { |
4a9e803e | 128 | switch (cb->compress_type) { |
1e4eb746 DS |
129 | case BTRFS_COMPRESS_ZLIB: return zlib_decompress_bio(ws, cb); |
130 | case BTRFS_COMPRESS_LZO: return lzo_decompress_bio(ws, cb); | |
131 | case BTRFS_COMPRESS_ZSTD: return zstd_decompress_bio(ws, cb); | |
132 | case BTRFS_COMPRESS_NONE: | |
133 | default: | |
134 | /* | |
135 | * This can't happen, the type is validated several times | |
136 | * before we get here. | |
137 | */ | |
138 | BUG(); | |
139 | } | |
140 | } | |
141 | ||
142 | static int compression_decompress(int type, struct list_head *ws, | |
3e09b5b2 | 143 | const u8 *data_in, struct page *dest_page, |
1e4eb746 DS |
144 | unsigned long start_byte, size_t srclen, size_t destlen) |
145 | { | |
146 | switch (type) { | |
147 | case BTRFS_COMPRESS_ZLIB: return zlib_decompress(ws, data_in, dest_page, | |
148 | start_byte, srclen, destlen); | |
149 | case BTRFS_COMPRESS_LZO: return lzo_decompress(ws, data_in, dest_page, | |
150 | start_byte, srclen, destlen); | |
151 | case BTRFS_COMPRESS_ZSTD: return zstd_decompress(ws, data_in, dest_page, | |
152 | start_byte, srclen, destlen); | |
153 | case BTRFS_COMPRESS_NONE: | |
154 | default: | |
155 | /* | |
156 | * This can't happen, the type is validated several times | |
157 | * before we get here. | |
158 | */ | |
159 | BUG(); | |
160 | } | |
161 | } | |
162 | ||
32586c5b CH |
163 | static void btrfs_free_compressed_pages(struct compressed_bio *cb) |
164 | { | |
a959a174 CH |
165 | for (unsigned int i = 0; i < cb->nr_pages; i++) |
166 | put_page(cb->compressed_pages[i]); | |
32586c5b CH |
167 | kfree(cb->compressed_pages); |
168 | } | |
169 | ||
8140dc30 | 170 | static int btrfs_decompress_bio(struct compressed_bio *cb); |
48a3b636 | 171 | |
30493ff4 | 172 | static void end_compressed_bio_read(struct btrfs_bio *bbio) |
86ccbb4d | 173 | { |
544fe4a9 CH |
174 | struct compressed_bio *cb = to_compressed_bio(bbio); |
175 | blk_status_t status = bbio->bio.bi_status; | |
86ccbb4d | 176 | |
544fe4a9 CH |
177 | if (!status) |
178 | status = errno_to_blk_status(btrfs_decompress_bio(cb)); | |
81bd9328 | 179 | |
32586c5b | 180 | btrfs_free_compressed_pages(cb); |
b7d463a1 | 181 | btrfs_bio_end_io(cb->orig_bbio, status); |
917f32a2 | 182 | bio_put(&bbio->bio); |
c8b97818 CM |
183 | } |
184 | ||
185 | /* | |
186 | * Clear the writeback bits on all of the file | |
187 | * pages for a compressed write | |
188 | */ | |
544fe4a9 | 189 | static noinline void end_compressed_writeback(const struct compressed_bio *cb) |
c8b97818 | 190 | { |
544fe4a9 | 191 | struct inode *inode = &cb->bbio.inode->vfs_inode; |
741ec653 | 192 | struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); |
09cbfeaf KS |
193 | unsigned long index = cb->start >> PAGE_SHIFT; |
194 | unsigned long end_index = (cb->start + cb->len - 1) >> PAGE_SHIFT; | |
a75b81c3 | 195 | struct folio_batch fbatch; |
544fe4a9 | 196 | const int errno = blk_status_to_errno(cb->bbio.bio.bi_status); |
c8b97818 CM |
197 | int i; |
198 | int ret; | |
199 | ||
606f82e7 JB |
200 | if (errno) |
201 | mapping_set_error(inode->i_mapping, errno); | |
7bdcefc1 | 202 | |
a75b81c3 VMO |
203 | folio_batch_init(&fbatch); |
204 | while (index <= end_index) { | |
205 | ret = filemap_get_folios(inode->i_mapping, &index, end_index, | |
206 | &fbatch); | |
207 | ||
208 | if (ret == 0) | |
209 | return; | |
210 | ||
c8b97818 | 211 | for (i = 0; i < ret; i++) { |
a75b81c3 VMO |
212 | struct folio *folio = fbatch.folios[i]; |
213 | ||
606f82e7 | 214 | if (errno) |
a75b81c3 VMO |
215 | folio_set_error(folio); |
216 | btrfs_page_clamp_clear_writeback(fs_info, &folio->page, | |
741ec653 | 217 | cb->start, cb->len); |
c8b97818 | 218 | } |
a75b81c3 | 219 | folio_batch_release(&fbatch); |
c8b97818 CM |
220 | } |
221 | /* the inode may be gone now */ | |
c8b97818 CM |
222 | } |
223 | ||
f9327a70 | 224 | static void btrfs_finish_compressed_write_work(struct work_struct *work) |
c8b97818 | 225 | { |
f9327a70 CH |
226 | struct compressed_bio *cb = |
227 | container_of(work, struct compressed_bio, write_end_work); | |
228 | ||
6853c64a QW |
229 | /* |
230 | * Ok, we're the last bio for this extent, step one is to call back | |
231 | * into the FS and do all the end_io operations. | |
c8b97818 | 232 | */ |
544fe4a9 | 233 | btrfs_writepage_endio_finish_ordered(cb->bbio.inode, NULL, |
c629732d | 234 | cb->start, cb->start + cb->len - 1, |
544fe4a9 | 235 | cb->bbio.bio.bi_status == BLK_STS_OK); |
c8b97818 | 236 | |
7c0c7269 | 237 | if (cb->writeback) |
544fe4a9 | 238 | end_compressed_writeback(cb); |
6853c64a | 239 | /* Note, our inode could be gone now */ |
c8b97818 | 240 | |
32586c5b | 241 | btrfs_free_compressed_pages(cb); |
544fe4a9 | 242 | bio_put(&cb->bbio.bio); |
6853c64a QW |
243 | } |
244 | ||
245 | /* | |
246 | * Do the cleanup once all the compressed pages hit the disk. This will clear | |
247 | * writeback on the file pages and free the compressed pages. | |
248 | * | |
249 | * This also calls the writeback end hooks for the file pages so that metadata | |
250 | * and checksums can be updated in the file. | |
251 | */ | |
917f32a2 | 252 | static void end_compressed_bio_write(struct btrfs_bio *bbio) |
6853c64a | 253 | { |
544fe4a9 CH |
254 | struct compressed_bio *cb = to_compressed_bio(bbio); |
255 | struct btrfs_fs_info *fs_info = bbio->inode->root->fs_info; | |
6853c64a | 256 | |
d5e4377d | 257 | queue_work(fs_info->compressed_write_workers, &cb->write_end_work); |
c8b97818 CM |
258 | } |
259 | ||
4513cb0c | 260 | static void btrfs_add_compressed_bio_pages(struct compressed_bio *cb) |
10e924bc | 261 | { |
10e924bc | 262 | struct bio *bio = &cb->bbio.bio; |
43fa4219 | 263 | u32 offset = 0; |
10e924bc | 264 | |
43fa4219 CH |
265 | while (offset < cb->compressed_len) { |
266 | u32 len = min_t(u32, cb->compressed_len - offset, PAGE_SIZE); | |
10e924bc | 267 | |
43fa4219 CH |
268 | /* Maximum compressed extent is smaller than bio size limit. */ |
269 | __bio_add_page(bio, cb->compressed_pages[offset >> PAGE_SHIFT], | |
270 | len, 0); | |
271 | offset += len; | |
10e924bc | 272 | } |
10e924bc CH |
273 | } |
274 | ||
c8b97818 CM |
275 | /* |
276 | * worker function to build and submit bios for previously compressed pages. | |
277 | * The corresponding pages in the inode should be marked for writeback | |
278 | * and the compressed pages should have a reference on them for dropping | |
279 | * when the IO is complete. | |
280 | * | |
281 | * This also checksums the file bytes and gets things ready for | |
282 | * the end io hooks. | |
283 | */ | |
544fe4a9 | 284 | void btrfs_submit_compressed_write(struct btrfs_inode *inode, u64 start, |
65b5355f AJ |
285 | unsigned int len, u64 disk_start, |
286 | unsigned int compressed_len, | |
c8b97818 | 287 | struct page **compressed_pages, |
65b5355f | 288 | unsigned int nr_pages, |
bf9486d6 | 289 | blk_opf_t write_flags, |
7c0c7269 | 290 | bool writeback) |
c8b97818 | 291 | { |
c7ee1819 | 292 | struct btrfs_fs_info *fs_info = inode->root->fs_info; |
c8b97818 | 293 | struct compressed_bio *cb; |
c8b97818 | 294 | |
bbbff01a QW |
295 | ASSERT(IS_ALIGNED(start, fs_info->sectorsize) && |
296 | IS_ALIGNED(len, fs_info->sectorsize)); | |
544fe4a9 | 297 | |
544fe4a9 CH |
298 | write_flags |= REQ_BTRFS_ONE_ORDERED; |
299 | ||
300 | cb = alloc_compressed_bio(inode, start, REQ_OP_WRITE | write_flags, | |
301 | end_compressed_bio_write); | |
c8b97818 CM |
302 | cb->start = start; |
303 | cb->len = len; | |
304 | cb->compressed_pages = compressed_pages; | |
305 | cb->compressed_len = compressed_len; | |
7c0c7269 | 306 | cb->writeback = writeback; |
fed8a72d | 307 | INIT_WORK(&cb->write_end_work, btrfs_finish_compressed_write_work); |
c8b97818 | 308 | cb->nr_pages = nr_pages; |
4513cb0c CH |
309 | cb->bbio.bio.bi_iter.bi_sector = disk_start >> SECTOR_SHIFT; |
310 | btrfs_add_compressed_bio_pages(cb); | |
c8b97818 | 311 | |
ae42a154 | 312 | btrfs_submit_bio(&cb->bbio, 0); |
c8b97818 CM |
313 | } |
314 | ||
6a404910 QW |
315 | /* |
316 | * Add extra pages in the same compressed file extent so that we don't need to | |
317 | * re-read the same extent again and again. | |
318 | * | |
319 | * NOTE: this won't work well for subpage, as for subpage read, we lock the | |
320 | * full page then submit bio for each compressed/regular extents. | |
321 | * | |
322 | * This means, if we have several sectors in the same page points to the same | |
323 | * on-disk compressed data, we will re-read the same extent many times and | |
324 | * this function can only help for the next page. | |
325 | */ | |
771ed689 CM |
326 | static noinline int add_ra_bio_pages(struct inode *inode, |
327 | u64 compressed_end, | |
4088a47e | 328 | struct compressed_bio *cb, |
82e60d00 | 329 | int *memstall, unsigned long *pflags) |
771ed689 | 330 | { |
6a404910 | 331 | struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); |
771ed689 | 332 | unsigned long end_index; |
b7d463a1 CH |
333 | struct bio *orig_bio = &cb->orig_bbio->bio; |
334 | u64 cur = cb->orig_bbio->file_offset + orig_bio->bi_iter.bi_size; | |
771ed689 CM |
335 | u64 isize = i_size_read(inode); |
336 | int ret; | |
337 | struct page *page; | |
771ed689 CM |
338 | struct extent_map *em; |
339 | struct address_space *mapping = inode->i_mapping; | |
771ed689 CM |
340 | struct extent_map_tree *em_tree; |
341 | struct extent_io_tree *tree; | |
6a404910 | 342 | int sectors_missed = 0; |
771ed689 | 343 | |
771ed689 CM |
344 | em_tree = &BTRFS_I(inode)->extent_tree; |
345 | tree = &BTRFS_I(inode)->io_tree; | |
346 | ||
347 | if (isize == 0) | |
348 | return 0; | |
349 | ||
ca62e85d QW |
350 | /* |
351 | * For current subpage support, we only support 64K page size, | |
352 | * which means maximum compressed extent size (128K) is just 2x page | |
353 | * size. | |
354 | * This makes readahead less effective, so here disable readahead for | |
355 | * subpage for now, until full compressed write is supported. | |
356 | */ | |
357 | if (btrfs_sb(inode->i_sb)->sectorsize < PAGE_SIZE) | |
358 | return 0; | |
359 | ||
09cbfeaf | 360 | end_index = (i_size_read(inode) - 1) >> PAGE_SHIFT; |
771ed689 | 361 | |
6a404910 QW |
362 | while (cur < compressed_end) { |
363 | u64 page_end; | |
364 | u64 pg_index = cur >> PAGE_SHIFT; | |
365 | u32 add_size; | |
771ed689 | 366 | |
306e16ce | 367 | if (pg_index > end_index) |
771ed689 CM |
368 | break; |
369 | ||
0a943c65 | 370 | page = xa_load(&mapping->i_pages, pg_index); |
3159f943 | 371 | if (page && !xa_is_value(page)) { |
6a404910 QW |
372 | sectors_missed += (PAGE_SIZE - offset_in_page(cur)) >> |
373 | fs_info->sectorsize_bits; | |
374 | ||
375 | /* Beyond threshold, no need to continue */ | |
376 | if (sectors_missed > 4) | |
771ed689 | 377 | break; |
6a404910 QW |
378 | |
379 | /* | |
380 | * Jump to next page start as we already have page for | |
381 | * current offset. | |
382 | */ | |
383 | cur = (pg_index << PAGE_SHIFT) + PAGE_SIZE; | |
384 | continue; | |
771ed689 CM |
385 | } |
386 | ||
c62d2555 MH |
387 | page = __page_cache_alloc(mapping_gfp_constraint(mapping, |
388 | ~__GFP_FS)); | |
771ed689 CM |
389 | if (!page) |
390 | break; | |
391 | ||
c62d2555 | 392 | if (add_to_page_cache_lru(page, mapping, pg_index, GFP_NOFS)) { |
09cbfeaf | 393 | put_page(page); |
6a404910 QW |
394 | /* There is already a page, skip to page end */ |
395 | cur = (pg_index << PAGE_SHIFT) + PAGE_SIZE; | |
396 | continue; | |
771ed689 CM |
397 | } |
398 | ||
82e60d00 | 399 | if (!*memstall && PageWorkingset(page)) { |
4088a47e | 400 | psi_memstall_enter(pflags); |
82e60d00 JW |
401 | *memstall = 1; |
402 | } | |
4088a47e | 403 | |
32443de3 QW |
404 | ret = set_page_extent_mapped(page); |
405 | if (ret < 0) { | |
406 | unlock_page(page); | |
407 | put_page(page); | |
408 | break; | |
409 | } | |
410 | ||
6a404910 | 411 | page_end = (pg_index << PAGE_SHIFT) + PAGE_SIZE - 1; |
570eb97b | 412 | lock_extent(tree, cur, page_end, NULL); |
890871be | 413 | read_lock(&em_tree->lock); |
6a404910 | 414 | em = lookup_extent_mapping(em_tree, cur, page_end + 1 - cur); |
890871be | 415 | read_unlock(&em_tree->lock); |
771ed689 | 416 | |
6a404910 QW |
417 | /* |
418 | * At this point, we have a locked page in the page cache for | |
419 | * these bytes in the file. But, we have to make sure they map | |
420 | * to this compressed extent on disk. | |
421 | */ | |
422 | if (!em || cur < em->start || | |
423 | (cur + fs_info->sectorsize > extent_map_end(em)) || | |
b7d463a1 | 424 | (em->block_start >> 9) != orig_bio->bi_iter.bi_sector) { |
771ed689 | 425 | free_extent_map(em); |
570eb97b | 426 | unlock_extent(tree, cur, page_end, NULL); |
771ed689 | 427 | unlock_page(page); |
09cbfeaf | 428 | put_page(page); |
771ed689 CM |
429 | break; |
430 | } | |
431 | free_extent_map(em); | |
432 | ||
433 | if (page->index == end_index) { | |
7073017a | 434 | size_t zero_offset = offset_in_page(isize); |
771ed689 CM |
435 | |
436 | if (zero_offset) { | |
437 | int zeros; | |
09cbfeaf | 438 | zeros = PAGE_SIZE - zero_offset; |
d048b9c2 | 439 | memzero_page(page, zero_offset, zeros); |
771ed689 CM |
440 | } |
441 | } | |
442 | ||
6a404910 | 443 | add_size = min(em->start + em->len, page_end + 1) - cur; |
b7d463a1 | 444 | ret = bio_add_page(orig_bio, page, add_size, offset_in_page(cur)); |
6a404910 | 445 | if (ret != add_size) { |
570eb97b | 446 | unlock_extent(tree, cur, page_end, NULL); |
771ed689 | 447 | unlock_page(page); |
09cbfeaf | 448 | put_page(page); |
771ed689 CM |
449 | break; |
450 | } | |
6a404910 QW |
451 | /* |
452 | * If it's subpage, we also need to increase its | |
453 | * subpage::readers number, as at endio we will decrease | |
454 | * subpage::readers and to unlock the page. | |
455 | */ | |
456 | if (fs_info->sectorsize < PAGE_SIZE) | |
457 | btrfs_subpage_start_reader(fs_info, page, cur, add_size); | |
458 | put_page(page); | |
459 | cur += add_size; | |
771ed689 | 460 | } |
771ed689 CM |
461 | return 0; |
462 | } | |
463 | ||
c8b97818 CM |
464 | /* |
465 | * for a compressed read, the bio we get passed has all the inode pages | |
466 | * in it. We don't actually do IO on those pages but allocate new ones | |
467 | * to hold the compressed pages on disk. | |
468 | * | |
4f024f37 | 469 | * bio->bi_iter.bi_sector points to the compressed extent on disk |
c8b97818 | 470 | * bio->bi_io_vec points to all of the inode pages |
c8b97818 CM |
471 | * |
472 | * After the compressed pages are read, we copy the bytes into the | |
473 | * bio we were passed and then call the bio end_io calls | |
474 | */ | |
690834e4 | 475 | void btrfs_submit_compressed_read(struct btrfs_bio *bbio, int mirror_num) |
c8b97818 | 476 | { |
690834e4 | 477 | struct btrfs_inode *inode = bbio->inode; |
544fe4a9 CH |
478 | struct btrfs_fs_info *fs_info = inode->root->fs_info; |
479 | struct extent_map_tree *em_tree = &inode->extent_tree; | |
c8b97818 | 480 | struct compressed_bio *cb; |
356b4a2d | 481 | unsigned int compressed_len; |
690834e4 | 482 | u64 file_offset = bbio->file_offset; |
e04ca626 CM |
483 | u64 em_len; |
484 | u64 em_start; | |
c8b97818 | 485 | struct extent_map *em; |
82e60d00 JW |
486 | unsigned long pflags; |
487 | int memstall = 0; | |
f9f15de8 | 488 | blk_status_t ret; |
dd137dd1 | 489 | int ret2; |
c8b97818 CM |
490 | |
491 | /* we need the actual starting offset of this extent in the file */ | |
890871be | 492 | read_lock(&em_tree->lock); |
557023ea | 493 | em = lookup_extent_mapping(em_tree, file_offset, fs_info->sectorsize); |
890871be | 494 | read_unlock(&em_tree->lock); |
f9f15de8 JB |
495 | if (!em) { |
496 | ret = BLK_STS_IOERR; | |
497 | goto out; | |
498 | } | |
c8b97818 | 499 | |
557023ea | 500 | ASSERT(em->compress_type != BTRFS_COMPRESS_NONE); |
d20f7043 | 501 | compressed_len = em->block_len; |
6b82ce8d | 502 | |
544fe4a9 CH |
503 | cb = alloc_compressed_bio(inode, file_offset, REQ_OP_READ, |
504 | end_compressed_bio_read); | |
c8b97818 | 505 | |
ff5b7ee3 | 506 | cb->start = em->orig_start; |
e04ca626 CM |
507 | em_len = em->len; |
508 | em_start = em->start; | |
d20f7043 | 509 | |
690834e4 | 510 | cb->len = bbio->bio.bi_iter.bi_size; |
c8b97818 | 511 | cb->compressed_len = compressed_len; |
1d8fa2e2 | 512 | cb->compress_type = em->compress_type; |
b7d463a1 | 513 | cb->orig_bbio = bbio; |
c8b97818 | 514 | |
1d8fa2e2 | 515 | free_extent_map(em); |
1d8fa2e2 | 516 | |
dd137dd1 STD |
517 | cb->nr_pages = DIV_ROUND_UP(compressed_len, PAGE_SIZE); |
518 | cb->compressed_pages = kcalloc(cb->nr_pages, sizeof(struct page *), GFP_NOFS); | |
f9f15de8 JB |
519 | if (!cb->compressed_pages) { |
520 | ret = BLK_STS_RESOURCE; | |
544fe4a9 | 521 | goto out_free_bio; |
f9f15de8 | 522 | } |
6b82ce8d | 523 | |
dd137dd1 STD |
524 | ret2 = btrfs_alloc_page_array(cb->nr_pages, cb->compressed_pages); |
525 | if (ret2) { | |
526 | ret = BLK_STS_RESOURCE; | |
544fe4a9 | 527 | goto out_free_compressed_pages; |
c8b97818 | 528 | } |
c8b97818 | 529 | |
544fe4a9 CH |
530 | add_ra_bio_pages(&inode->vfs_inode, em_start + em_len, cb, &memstall, |
531 | &pflags); | |
771ed689 | 532 | |
771ed689 | 533 | /* include any pages we added in add_ra-bio_pages */ |
690834e4 | 534 | cb->len = bbio->bio.bi_iter.bi_size; |
4513cb0c CH |
535 | cb->bbio.bio.bi_iter.bi_sector = bbio->bio.bi_iter.bi_sector; |
536 | btrfs_add_compressed_bio_pages(cb); | |
524bcd1e | 537 | |
82e60d00 | 538 | if (memstall) |
4088a47e CH |
539 | psi_memstall_leave(&pflags); |
540 | ||
ae42a154 | 541 | btrfs_submit_bio(&cb->bbio, mirror_num); |
cb4411dd | 542 | return; |
6b82ce8d | 543 | |
544fe4a9 | 544 | out_free_compressed_pages: |
6b82ce8d | 545 | kfree(cb->compressed_pages); |
544fe4a9 | 546 | out_free_bio: |
10e924bc | 547 | bio_put(&cb->bbio.bio); |
544fe4a9 | 548 | out: |
690834e4 | 549 | btrfs_bio_end_io(bbio, ret); |
c8b97818 | 550 | } |
261507a0 | 551 | |
17b5a6c1 TT |
552 | /* |
553 | * Heuristic uses systematic sampling to collect data from the input data | |
554 | * range, the logic can be tuned by the following constants: | |
555 | * | |
556 | * @SAMPLING_READ_SIZE - how many bytes will be copied from for each sample | |
557 | * @SAMPLING_INTERVAL - range from which the sampled data can be collected | |
558 | */ | |
559 | #define SAMPLING_READ_SIZE (16) | |
560 | #define SAMPLING_INTERVAL (256) | |
561 | ||
562 | /* | |
563 | * For statistical analysis of the input data we consider bytes that form a | |
564 | * Galois Field of 256 objects. Each object has an attribute count, ie. how | |
565 | * many times the object appeared in the sample. | |
566 | */ | |
567 | #define BUCKET_SIZE (256) | |
568 | ||
569 | /* | |
570 | * The size of the sample is based on a statistical sampling rule of thumb. | |
571 | * The common way is to perform sampling tests as long as the number of | |
572 | * elements in each cell is at least 5. | |
573 | * | |
574 | * Instead of 5, we choose 32 to obtain more accurate results. | |
575 | * If the data contain the maximum number of symbols, which is 256, we obtain a | |
576 | * sample size bound by 8192. | |
577 | * | |
578 | * For a sample of at most 8KB of data per data range: 16 consecutive bytes | |
579 | * from up to 512 locations. | |
580 | */ | |
581 | #define MAX_SAMPLE_SIZE (BTRFS_MAX_UNCOMPRESSED * \ | |
582 | SAMPLING_READ_SIZE / SAMPLING_INTERVAL) | |
583 | ||
584 | struct bucket_item { | |
585 | u32 count; | |
586 | }; | |
4e439a0b TT |
587 | |
588 | struct heuristic_ws { | |
17b5a6c1 TT |
589 | /* Partial copy of input data */ |
590 | u8 *sample; | |
a440d48c | 591 | u32 sample_size; |
17b5a6c1 TT |
592 | /* Buckets store counters for each byte value */ |
593 | struct bucket_item *bucket; | |
440c840c TT |
594 | /* Sorting buffer */ |
595 | struct bucket_item *bucket_b; | |
4e439a0b TT |
596 | struct list_head list; |
597 | }; | |
598 | ||
92ee5530 DZ |
599 | static struct workspace_manager heuristic_wsm; |
600 | ||
4e439a0b TT |
601 | static void free_heuristic_ws(struct list_head *ws) |
602 | { | |
603 | struct heuristic_ws *workspace; | |
604 | ||
605 | workspace = list_entry(ws, struct heuristic_ws, list); | |
606 | ||
17b5a6c1 TT |
607 | kvfree(workspace->sample); |
608 | kfree(workspace->bucket); | |
440c840c | 609 | kfree(workspace->bucket_b); |
4e439a0b TT |
610 | kfree(workspace); |
611 | } | |
612 | ||
7bf49943 | 613 | static struct list_head *alloc_heuristic_ws(unsigned int level) |
4e439a0b TT |
614 | { |
615 | struct heuristic_ws *ws; | |
616 | ||
617 | ws = kzalloc(sizeof(*ws), GFP_KERNEL); | |
618 | if (!ws) | |
619 | return ERR_PTR(-ENOMEM); | |
620 | ||
17b5a6c1 TT |
621 | ws->sample = kvmalloc(MAX_SAMPLE_SIZE, GFP_KERNEL); |
622 | if (!ws->sample) | |
623 | goto fail; | |
624 | ||
625 | ws->bucket = kcalloc(BUCKET_SIZE, sizeof(*ws->bucket), GFP_KERNEL); | |
626 | if (!ws->bucket) | |
627 | goto fail; | |
4e439a0b | 628 | |
440c840c TT |
629 | ws->bucket_b = kcalloc(BUCKET_SIZE, sizeof(*ws->bucket_b), GFP_KERNEL); |
630 | if (!ws->bucket_b) | |
631 | goto fail; | |
632 | ||
17b5a6c1 | 633 | INIT_LIST_HEAD(&ws->list); |
4e439a0b | 634 | return &ws->list; |
17b5a6c1 TT |
635 | fail: |
636 | free_heuristic_ws(&ws->list); | |
637 | return ERR_PTR(-ENOMEM); | |
4e439a0b TT |
638 | } |
639 | ||
ca4ac360 | 640 | const struct btrfs_compress_op btrfs_heuristic_compress = { |
be951045 | 641 | .workspace_manager = &heuristic_wsm, |
ca4ac360 DZ |
642 | }; |
643 | ||
e8c9f186 | 644 | static const struct btrfs_compress_op * const btrfs_compress_op[] = { |
ca4ac360 DZ |
645 | /* The heuristic is represented as compression type 0 */ |
646 | &btrfs_heuristic_compress, | |
261507a0 | 647 | &btrfs_zlib_compress, |
a6fa6fae | 648 | &btrfs_lzo_compress, |
5c1aab1d | 649 | &btrfs_zstd_compress, |
261507a0 LZ |
650 | }; |
651 | ||
c778df14 DS |
652 | static struct list_head *alloc_workspace(int type, unsigned int level) |
653 | { | |
654 | switch (type) { | |
655 | case BTRFS_COMPRESS_NONE: return alloc_heuristic_ws(level); | |
656 | case BTRFS_COMPRESS_ZLIB: return zlib_alloc_workspace(level); | |
657 | case BTRFS_COMPRESS_LZO: return lzo_alloc_workspace(level); | |
658 | case BTRFS_COMPRESS_ZSTD: return zstd_alloc_workspace(level); | |
659 | default: | |
660 | /* | |
661 | * This can't happen, the type is validated several times | |
662 | * before we get here. | |
663 | */ | |
664 | BUG(); | |
665 | } | |
666 | } | |
667 | ||
1e002351 DS |
668 | static void free_workspace(int type, struct list_head *ws) |
669 | { | |
670 | switch (type) { | |
671 | case BTRFS_COMPRESS_NONE: return free_heuristic_ws(ws); | |
672 | case BTRFS_COMPRESS_ZLIB: return zlib_free_workspace(ws); | |
673 | case BTRFS_COMPRESS_LZO: return lzo_free_workspace(ws); | |
674 | case BTRFS_COMPRESS_ZSTD: return zstd_free_workspace(ws); | |
675 | default: | |
676 | /* | |
677 | * This can't happen, the type is validated several times | |
678 | * before we get here. | |
679 | */ | |
680 | BUG(); | |
681 | } | |
682 | } | |
683 | ||
d5517033 | 684 | static void btrfs_init_workspace_manager(int type) |
261507a0 | 685 | { |
0cf25213 | 686 | struct workspace_manager *wsm; |
4e439a0b | 687 | struct list_head *workspace; |
261507a0 | 688 | |
0cf25213 | 689 | wsm = btrfs_compress_op[type]->workspace_manager; |
92ee5530 DZ |
690 | INIT_LIST_HEAD(&wsm->idle_ws); |
691 | spin_lock_init(&wsm->ws_lock); | |
692 | atomic_set(&wsm->total_ws, 0); | |
693 | init_waitqueue_head(&wsm->ws_wait); | |
f77dd0d6 | 694 | |
1666edab DZ |
695 | /* |
696 | * Preallocate one workspace for each compression type so we can | |
697 | * guarantee forward progress in the worst case | |
698 | */ | |
c778df14 | 699 | workspace = alloc_workspace(type, 0); |
1666edab DZ |
700 | if (IS_ERR(workspace)) { |
701 | pr_warn( | |
702 | "BTRFS: cannot preallocate compression workspace, will try later\n"); | |
703 | } else { | |
92ee5530 DZ |
704 | atomic_set(&wsm->total_ws, 1); |
705 | wsm->free_ws = 1; | |
706 | list_add(workspace, &wsm->idle_ws); | |
1666edab DZ |
707 | } |
708 | } | |
709 | ||
2510307e | 710 | static void btrfs_cleanup_workspace_manager(int type) |
1666edab | 711 | { |
2dba7143 | 712 | struct workspace_manager *wsman; |
1666edab DZ |
713 | struct list_head *ws; |
714 | ||
2dba7143 | 715 | wsman = btrfs_compress_op[type]->workspace_manager; |
1666edab DZ |
716 | while (!list_empty(&wsman->idle_ws)) { |
717 | ws = wsman->idle_ws.next; | |
718 | list_del(ws); | |
1e002351 | 719 | free_workspace(type, ws); |
1666edab | 720 | atomic_dec(&wsman->total_ws); |
261507a0 | 721 | } |
261507a0 LZ |
722 | } |
723 | ||
724 | /* | |
e721e49d DS |
725 | * This finds an available workspace or allocates a new one. |
726 | * If it's not possible to allocate a new one, waits until there's one. | |
727 | * Preallocation makes a forward progress guarantees and we do not return | |
728 | * errors. | |
261507a0 | 729 | */ |
5907a9bb | 730 | struct list_head *btrfs_get_workspace(int type, unsigned int level) |
261507a0 | 731 | { |
5907a9bb | 732 | struct workspace_manager *wsm; |
261507a0 LZ |
733 | struct list_head *workspace; |
734 | int cpus = num_online_cpus(); | |
fe308533 | 735 | unsigned nofs_flag; |
4e439a0b TT |
736 | struct list_head *idle_ws; |
737 | spinlock_t *ws_lock; | |
738 | atomic_t *total_ws; | |
739 | wait_queue_head_t *ws_wait; | |
740 | int *free_ws; | |
741 | ||
5907a9bb | 742 | wsm = btrfs_compress_op[type]->workspace_manager; |
92ee5530 DZ |
743 | idle_ws = &wsm->idle_ws; |
744 | ws_lock = &wsm->ws_lock; | |
745 | total_ws = &wsm->total_ws; | |
746 | ws_wait = &wsm->ws_wait; | |
747 | free_ws = &wsm->free_ws; | |
261507a0 | 748 | |
261507a0 | 749 | again: |
d9187649 BL |
750 | spin_lock(ws_lock); |
751 | if (!list_empty(idle_ws)) { | |
752 | workspace = idle_ws->next; | |
261507a0 | 753 | list_del(workspace); |
6ac10a6a | 754 | (*free_ws)--; |
d9187649 | 755 | spin_unlock(ws_lock); |
261507a0 LZ |
756 | return workspace; |
757 | ||
758 | } | |
6ac10a6a | 759 | if (atomic_read(total_ws) > cpus) { |
261507a0 LZ |
760 | DEFINE_WAIT(wait); |
761 | ||
d9187649 BL |
762 | spin_unlock(ws_lock); |
763 | prepare_to_wait(ws_wait, &wait, TASK_UNINTERRUPTIBLE); | |
6ac10a6a | 764 | if (atomic_read(total_ws) > cpus && !*free_ws) |
261507a0 | 765 | schedule(); |
d9187649 | 766 | finish_wait(ws_wait, &wait); |
261507a0 LZ |
767 | goto again; |
768 | } | |
6ac10a6a | 769 | atomic_inc(total_ws); |
d9187649 | 770 | spin_unlock(ws_lock); |
261507a0 | 771 | |
fe308533 DS |
772 | /* |
773 | * Allocation helpers call vmalloc that can't use GFP_NOFS, so we have | |
774 | * to turn it off here because we might get called from the restricted | |
775 | * context of btrfs_compress_bio/btrfs_compress_pages | |
776 | */ | |
777 | nofs_flag = memalloc_nofs_save(); | |
c778df14 | 778 | workspace = alloc_workspace(type, level); |
fe308533 DS |
779 | memalloc_nofs_restore(nofs_flag); |
780 | ||
261507a0 | 781 | if (IS_ERR(workspace)) { |
6ac10a6a | 782 | atomic_dec(total_ws); |
d9187649 | 783 | wake_up(ws_wait); |
e721e49d DS |
784 | |
785 | /* | |
786 | * Do not return the error but go back to waiting. There's a | |
787 | * workspace preallocated for each type and the compression | |
788 | * time is bounded so we get to a workspace eventually. This | |
789 | * makes our caller's life easier. | |
52356716 DS |
790 | * |
791 | * To prevent silent and low-probability deadlocks (when the | |
792 | * initial preallocation fails), check if there are any | |
793 | * workspaces at all. | |
e721e49d | 794 | */ |
52356716 DS |
795 | if (atomic_read(total_ws) == 0) { |
796 | static DEFINE_RATELIMIT_STATE(_rs, | |
797 | /* once per minute */ 60 * HZ, | |
798 | /* no burst */ 1); | |
799 | ||
800 | if (__ratelimit(&_rs)) { | |
ab8d0fc4 | 801 | pr_warn("BTRFS: no compression workspaces, low memory, retrying\n"); |
52356716 DS |
802 | } |
803 | } | |
e721e49d | 804 | goto again; |
261507a0 LZ |
805 | } |
806 | return workspace; | |
807 | } | |
808 | ||
7bf49943 | 809 | static struct list_head *get_workspace(int type, int level) |
929f4baf | 810 | { |
6a0d1272 | 811 | switch (type) { |
5907a9bb | 812 | case BTRFS_COMPRESS_NONE: return btrfs_get_workspace(type, level); |
6a0d1272 | 813 | case BTRFS_COMPRESS_ZLIB: return zlib_get_workspace(level); |
5907a9bb | 814 | case BTRFS_COMPRESS_LZO: return btrfs_get_workspace(type, level); |
6a0d1272 DS |
815 | case BTRFS_COMPRESS_ZSTD: return zstd_get_workspace(level); |
816 | default: | |
817 | /* | |
818 | * This can't happen, the type is validated several times | |
819 | * before we get here. | |
820 | */ | |
821 | BUG(); | |
822 | } | |
929f4baf DZ |
823 | } |
824 | ||
261507a0 LZ |
825 | /* |
826 | * put a workspace struct back on the list or free it if we have enough | |
827 | * idle ones sitting around | |
828 | */ | |
a3bbd2a9 | 829 | void btrfs_put_workspace(int type, struct list_head *ws) |
261507a0 | 830 | { |
a3bbd2a9 | 831 | struct workspace_manager *wsm; |
4e439a0b TT |
832 | struct list_head *idle_ws; |
833 | spinlock_t *ws_lock; | |
834 | atomic_t *total_ws; | |
835 | wait_queue_head_t *ws_wait; | |
836 | int *free_ws; | |
837 | ||
a3bbd2a9 | 838 | wsm = btrfs_compress_op[type]->workspace_manager; |
92ee5530 DZ |
839 | idle_ws = &wsm->idle_ws; |
840 | ws_lock = &wsm->ws_lock; | |
841 | total_ws = &wsm->total_ws; | |
842 | ws_wait = &wsm->ws_wait; | |
843 | free_ws = &wsm->free_ws; | |
d9187649 BL |
844 | |
845 | spin_lock(ws_lock); | |
26b28dce | 846 | if (*free_ws <= num_online_cpus()) { |
929f4baf | 847 | list_add(ws, idle_ws); |
6ac10a6a | 848 | (*free_ws)++; |
d9187649 | 849 | spin_unlock(ws_lock); |
261507a0 LZ |
850 | goto wake; |
851 | } | |
d9187649 | 852 | spin_unlock(ws_lock); |
261507a0 | 853 | |
1e002351 | 854 | free_workspace(type, ws); |
6ac10a6a | 855 | atomic_dec(total_ws); |
261507a0 | 856 | wake: |
093258e6 | 857 | cond_wake_up(ws_wait); |
261507a0 LZ |
858 | } |
859 | ||
929f4baf DZ |
860 | static void put_workspace(int type, struct list_head *ws) |
861 | { | |
bd3a5287 | 862 | switch (type) { |
a3bbd2a9 DS |
863 | case BTRFS_COMPRESS_NONE: return btrfs_put_workspace(type, ws); |
864 | case BTRFS_COMPRESS_ZLIB: return btrfs_put_workspace(type, ws); | |
865 | case BTRFS_COMPRESS_LZO: return btrfs_put_workspace(type, ws); | |
bd3a5287 DS |
866 | case BTRFS_COMPRESS_ZSTD: return zstd_put_workspace(ws); |
867 | default: | |
868 | /* | |
869 | * This can't happen, the type is validated several times | |
870 | * before we get here. | |
871 | */ | |
872 | BUG(); | |
873 | } | |
929f4baf DZ |
874 | } |
875 | ||
adbab642 AJ |
876 | /* |
877 | * Adjust @level according to the limits of the compression algorithm or | |
878 | * fallback to default | |
879 | */ | |
880 | static unsigned int btrfs_compress_set_level(int type, unsigned level) | |
881 | { | |
882 | const struct btrfs_compress_op *ops = btrfs_compress_op[type]; | |
883 | ||
884 | if (level == 0) | |
885 | level = ops->default_level; | |
886 | else | |
887 | level = min(level, ops->max_level); | |
888 | ||
889 | return level; | |
890 | } | |
891 | ||
261507a0 | 892 | /* |
38c31464 DS |
893 | * Given an address space and start and length, compress the bytes into @pages |
894 | * that are allocated on demand. | |
261507a0 | 895 | * |
f51d2b59 DS |
896 | * @type_level is encoded algorithm and level, where level 0 means whatever |
897 | * default the algorithm chooses and is opaque here; | |
898 | * - compression algo are 0-3 | |
899 | * - the level are bits 4-7 | |
900 | * | |
4d3a800e DS |
901 | * @out_pages is an in/out parameter, holds maximum number of pages to allocate |
902 | * and returns number of actually allocated pages | |
261507a0 | 903 | * |
38c31464 DS |
904 | * @total_in is used to return the number of bytes actually read. It |
905 | * may be smaller than the input length if we had to exit early because we | |
261507a0 LZ |
906 | * ran out of room in the pages array or because we cross the |
907 | * max_out threshold. | |
908 | * | |
38c31464 DS |
909 | * @total_out is an in/out parameter, must be set to the input length and will |
910 | * be also used to return the total number of compressed bytes | |
261507a0 | 911 | */ |
f51d2b59 | 912 | int btrfs_compress_pages(unsigned int type_level, struct address_space *mapping, |
38c31464 | 913 | u64 start, struct page **pages, |
261507a0 LZ |
914 | unsigned long *out_pages, |
915 | unsigned long *total_in, | |
e5d74902 | 916 | unsigned long *total_out) |
261507a0 | 917 | { |
1972708a | 918 | int type = btrfs_compress_type(type_level); |
7bf49943 | 919 | int level = btrfs_compress_level(type_level); |
261507a0 LZ |
920 | struct list_head *workspace; |
921 | int ret; | |
922 | ||
b0c1fe1e | 923 | level = btrfs_compress_set_level(type, level); |
7bf49943 | 924 | workspace = get_workspace(type, level); |
1e4eb746 DS |
925 | ret = compression_compress_pages(type, workspace, mapping, start, pages, |
926 | out_pages, total_in, total_out); | |
929f4baf | 927 | put_workspace(type, workspace); |
261507a0 LZ |
928 | return ret; |
929 | } | |
930 | ||
8140dc30 | 931 | static int btrfs_decompress_bio(struct compressed_bio *cb) |
261507a0 LZ |
932 | { |
933 | struct list_head *workspace; | |
934 | int ret; | |
8140dc30 | 935 | int type = cb->compress_type; |
261507a0 | 936 | |
7bf49943 | 937 | workspace = get_workspace(type, 0); |
4a9e803e | 938 | ret = compression_decompress_bio(workspace, cb); |
929f4baf | 939 | put_workspace(type, workspace); |
e1ddce71 | 940 | |
7edb9a3e | 941 | if (!ret) |
b7d463a1 | 942 | zero_fill_bio(&cb->orig_bbio->bio); |
261507a0 LZ |
943 | return ret; |
944 | } | |
945 | ||
946 | /* | |
947 | * a less complex decompression routine. Our compressed data fits in a | |
948 | * single page, and we want to read a single page out of it. | |
949 | * start_byte tells us the offset into the compressed data we're interested in | |
950 | */ | |
3e09b5b2 | 951 | int btrfs_decompress(int type, const u8 *data_in, struct page *dest_page, |
261507a0 LZ |
952 | unsigned long start_byte, size_t srclen, size_t destlen) |
953 | { | |
954 | struct list_head *workspace; | |
955 | int ret; | |
956 | ||
7bf49943 | 957 | workspace = get_workspace(type, 0); |
1e4eb746 DS |
958 | ret = compression_decompress(type, workspace, data_in, dest_page, |
959 | start_byte, srclen, destlen); | |
929f4baf | 960 | put_workspace(type, workspace); |
7bf49943 | 961 | |
261507a0 LZ |
962 | return ret; |
963 | } | |
964 | ||
5565b8e0 | 965 | int __init btrfs_init_compress(void) |
1666edab | 966 | { |
544fe4a9 CH |
967 | if (bioset_init(&btrfs_compressed_bioset, BIO_POOL_SIZE, |
968 | offsetof(struct compressed_bio, bbio.bio), | |
969 | BIOSET_NEED_BVECS)) | |
970 | return -ENOMEM; | |
d5517033 DS |
971 | btrfs_init_workspace_manager(BTRFS_COMPRESS_NONE); |
972 | btrfs_init_workspace_manager(BTRFS_COMPRESS_ZLIB); | |
973 | btrfs_init_workspace_manager(BTRFS_COMPRESS_LZO); | |
974 | zstd_init_workspace_manager(); | |
5565b8e0 | 975 | return 0; |
1666edab DZ |
976 | } |
977 | ||
e67c718b | 978 | void __cold btrfs_exit_compress(void) |
261507a0 | 979 | { |
2510307e DS |
980 | btrfs_cleanup_workspace_manager(BTRFS_COMPRESS_NONE); |
981 | btrfs_cleanup_workspace_manager(BTRFS_COMPRESS_ZLIB); | |
982 | btrfs_cleanup_workspace_manager(BTRFS_COMPRESS_LZO); | |
983 | zstd_cleanup_workspace_manager(); | |
544fe4a9 | 984 | bioset_exit(&btrfs_compressed_bioset); |
261507a0 | 985 | } |
3a39c18d LZ |
986 | |
987 | /* | |
1c3dc173 | 988 | * Copy decompressed data from working buffer to pages. |
3a39c18d | 989 | * |
1c3dc173 QW |
990 | * @buf: The decompressed data buffer |
991 | * @buf_len: The decompressed data length | |
992 | * @decompressed: Number of bytes that are already decompressed inside the | |
993 | * compressed extent | |
994 | * @cb: The compressed extent descriptor | |
995 | * @orig_bio: The original bio that the caller wants to read for | |
3a39c18d | 996 | * |
1c3dc173 QW |
997 | * An easier to understand graph is like below: |
998 | * | |
999 | * |<- orig_bio ->| |<- orig_bio->| | |
1000 | * |<------- full decompressed extent ----->| | |
1001 | * |<----------- @cb range ---->| | |
1002 | * | |<-- @buf_len -->| | |
1003 | * |<--- @decompressed --->| | |
1004 | * | |
1005 | * Note that, @cb can be a subpage of the full decompressed extent, but | |
1006 | * @cb->start always has the same as the orig_file_offset value of the full | |
1007 | * decompressed extent. | |
1008 | * | |
1009 | * When reading compressed extent, we have to read the full compressed extent, | |
1010 | * while @orig_bio may only want part of the range. | |
1011 | * Thus this function will ensure only data covered by @orig_bio will be copied | |
1012 | * to. | |
1013 | * | |
1014 | * Return 0 if we have copied all needed contents for @orig_bio. | |
1015 | * Return >0 if we need continue decompress. | |
3a39c18d | 1016 | */ |
1c3dc173 QW |
1017 | int btrfs_decompress_buf2page(const char *buf, u32 buf_len, |
1018 | struct compressed_bio *cb, u32 decompressed) | |
3a39c18d | 1019 | { |
b7d463a1 | 1020 | struct bio *orig_bio = &cb->orig_bbio->bio; |
1c3dc173 QW |
1021 | /* Offset inside the full decompressed extent */ |
1022 | u32 cur_offset; | |
1023 | ||
1024 | cur_offset = decompressed; | |
1025 | /* The main loop to do the copy */ | |
1026 | while (cur_offset < decompressed + buf_len) { | |
1027 | struct bio_vec bvec; | |
1028 | size_t copy_len; | |
1029 | u32 copy_start; | |
1030 | /* Offset inside the full decompressed extent */ | |
1031 | u32 bvec_offset; | |
1032 | ||
1033 | bvec = bio_iter_iovec(orig_bio, orig_bio->bi_iter); | |
1034 | /* | |
1035 | * cb->start may underflow, but subtracting that value can still | |
1036 | * give us correct offset inside the full decompressed extent. | |
1037 | */ | |
1038 | bvec_offset = page_offset(bvec.bv_page) + bvec.bv_offset - cb->start; | |
974b1adc | 1039 | |
1c3dc173 QW |
1040 | /* Haven't reached the bvec range, exit */ |
1041 | if (decompressed + buf_len <= bvec_offset) | |
1042 | return 1; | |
3a39c18d | 1043 | |
1c3dc173 QW |
1044 | copy_start = max(cur_offset, bvec_offset); |
1045 | copy_len = min(bvec_offset + bvec.bv_len, | |
1046 | decompressed + buf_len) - copy_start; | |
1047 | ASSERT(copy_len); | |
3a39c18d | 1048 | |
974b1adc | 1049 | /* |
1c3dc173 QW |
1050 | * Extra range check to ensure we didn't go beyond |
1051 | * @buf + @buf_len. | |
974b1adc | 1052 | */ |
1c3dc173 QW |
1053 | ASSERT(copy_start - decompressed < buf_len); |
1054 | memcpy_to_page(bvec.bv_page, bvec.bv_offset, | |
1055 | buf + copy_start - decompressed, copy_len); | |
1c3dc173 | 1056 | cur_offset += copy_len; |
3a39c18d | 1057 | |
1c3dc173 QW |
1058 | bio_advance(orig_bio, copy_len); |
1059 | /* Finished the bio */ | |
1060 | if (!orig_bio->bi_iter.bi_size) | |
1061 | return 0; | |
3a39c18d | 1062 | } |
3a39c18d LZ |
1063 | return 1; |
1064 | } | |
c2fcdcdf | 1065 | |
19562430 TT |
1066 | /* |
1067 | * Shannon Entropy calculation | |
1068 | * | |
52042d8e | 1069 | * Pure byte distribution analysis fails to determine compressibility of data. |
19562430 TT |
1070 | * Try calculating entropy to estimate the average minimum number of bits |
1071 | * needed to encode the sampled data. | |
1072 | * | |
1073 | * For convenience, return the percentage of needed bits, instead of amount of | |
1074 | * bits directly. | |
1075 | * | |
1076 | * @ENTROPY_LVL_ACEPTABLE - below that threshold, sample has low byte entropy | |
1077 | * and can be compressible with high probability | |
1078 | * | |
1079 | * @ENTROPY_LVL_HIGH - data are not compressible with high probability | |
1080 | * | |
1081 | * Use of ilog2() decreases precision, we lower the LVL to 5 to compensate. | |
1082 | */ | |
1083 | #define ENTROPY_LVL_ACEPTABLE (65) | |
1084 | #define ENTROPY_LVL_HIGH (80) | |
1085 | ||
1086 | /* | |
1087 | * For increasead precision in shannon_entropy calculation, | |
1088 | * let's do pow(n, M) to save more digits after comma: | |
1089 | * | |
1090 | * - maximum int bit length is 64 | |
1091 | * - ilog2(MAX_SAMPLE_SIZE) -> 13 | |
1092 | * - 13 * 4 = 52 < 64 -> M = 4 | |
1093 | * | |
1094 | * So use pow(n, 4). | |
1095 | */ | |
1096 | static inline u32 ilog2_w(u64 n) | |
1097 | { | |
1098 | return ilog2(n * n * n * n); | |
1099 | } | |
1100 | ||
1101 | static u32 shannon_entropy(struct heuristic_ws *ws) | |
1102 | { | |
1103 | const u32 entropy_max = 8 * ilog2_w(2); | |
1104 | u32 entropy_sum = 0; | |
1105 | u32 p, p_base, sz_base; | |
1106 | u32 i; | |
1107 | ||
1108 | sz_base = ilog2_w(ws->sample_size); | |
1109 | for (i = 0; i < BUCKET_SIZE && ws->bucket[i].count > 0; i++) { | |
1110 | p = ws->bucket[i].count; | |
1111 | p_base = ilog2_w(p); | |
1112 | entropy_sum += p * (sz_base - p_base); | |
1113 | } | |
1114 | ||
1115 | entropy_sum /= ws->sample_size; | |
1116 | return entropy_sum * 100 / entropy_max; | |
1117 | } | |
1118 | ||
440c840c TT |
1119 | #define RADIX_BASE 4U |
1120 | #define COUNTERS_SIZE (1U << RADIX_BASE) | |
1121 | ||
1122 | static u8 get4bits(u64 num, int shift) { | |
1123 | u8 low4bits; | |
1124 | ||
1125 | num >>= shift; | |
1126 | /* Reverse order */ | |
1127 | low4bits = (COUNTERS_SIZE - 1) - (num % COUNTERS_SIZE); | |
1128 | return low4bits; | |
1129 | } | |
1130 | ||
440c840c TT |
1131 | /* |
1132 | * Use 4 bits as radix base | |
52042d8e | 1133 | * Use 16 u32 counters for calculating new position in buf array |
440c840c TT |
1134 | * |
1135 | * @array - array that will be sorted | |
1136 | * @array_buf - buffer array to store sorting results | |
1137 | * must be equal in size to @array | |
1138 | * @num - array size | |
440c840c | 1139 | */ |
23ae8c63 | 1140 | static void radix_sort(struct bucket_item *array, struct bucket_item *array_buf, |
36243c91 | 1141 | int num) |
858177d3 | 1142 | { |
440c840c TT |
1143 | u64 max_num; |
1144 | u64 buf_num; | |
1145 | u32 counters[COUNTERS_SIZE]; | |
1146 | u32 new_addr; | |
1147 | u32 addr; | |
1148 | int bitlen; | |
1149 | int shift; | |
1150 | int i; | |
858177d3 | 1151 | |
440c840c TT |
1152 | /* |
1153 | * Try avoid useless loop iterations for small numbers stored in big | |
1154 | * counters. Example: 48 33 4 ... in 64bit array | |
1155 | */ | |
23ae8c63 | 1156 | max_num = array[0].count; |
440c840c | 1157 | for (i = 1; i < num; i++) { |
23ae8c63 | 1158 | buf_num = array[i].count; |
440c840c TT |
1159 | if (buf_num > max_num) |
1160 | max_num = buf_num; | |
1161 | } | |
1162 | ||
1163 | buf_num = ilog2(max_num); | |
1164 | bitlen = ALIGN(buf_num, RADIX_BASE * 2); | |
1165 | ||
1166 | shift = 0; | |
1167 | while (shift < bitlen) { | |
1168 | memset(counters, 0, sizeof(counters)); | |
1169 | ||
1170 | for (i = 0; i < num; i++) { | |
23ae8c63 | 1171 | buf_num = array[i].count; |
440c840c TT |
1172 | addr = get4bits(buf_num, shift); |
1173 | counters[addr]++; | |
1174 | } | |
1175 | ||
1176 | for (i = 1; i < COUNTERS_SIZE; i++) | |
1177 | counters[i] += counters[i - 1]; | |
1178 | ||
1179 | for (i = num - 1; i >= 0; i--) { | |
23ae8c63 | 1180 | buf_num = array[i].count; |
440c840c TT |
1181 | addr = get4bits(buf_num, shift); |
1182 | counters[addr]--; | |
1183 | new_addr = counters[addr]; | |
7add17be | 1184 | array_buf[new_addr] = array[i]; |
440c840c TT |
1185 | } |
1186 | ||
1187 | shift += RADIX_BASE; | |
1188 | ||
1189 | /* | |
1190 | * Normal radix expects to move data from a temporary array, to | |
1191 | * the main one. But that requires some CPU time. Avoid that | |
1192 | * by doing another sort iteration to original array instead of | |
1193 | * memcpy() | |
1194 | */ | |
1195 | memset(counters, 0, sizeof(counters)); | |
1196 | ||
1197 | for (i = 0; i < num; i ++) { | |
23ae8c63 | 1198 | buf_num = array_buf[i].count; |
440c840c TT |
1199 | addr = get4bits(buf_num, shift); |
1200 | counters[addr]++; | |
1201 | } | |
1202 | ||
1203 | for (i = 1; i < COUNTERS_SIZE; i++) | |
1204 | counters[i] += counters[i - 1]; | |
1205 | ||
1206 | for (i = num - 1; i >= 0; i--) { | |
23ae8c63 | 1207 | buf_num = array_buf[i].count; |
440c840c TT |
1208 | addr = get4bits(buf_num, shift); |
1209 | counters[addr]--; | |
1210 | new_addr = counters[addr]; | |
7add17be | 1211 | array[new_addr] = array_buf[i]; |
440c840c TT |
1212 | } |
1213 | ||
1214 | shift += RADIX_BASE; | |
1215 | } | |
858177d3 TT |
1216 | } |
1217 | ||
1218 | /* | |
1219 | * Size of the core byte set - how many bytes cover 90% of the sample | |
1220 | * | |
1221 | * There are several types of structured binary data that use nearly all byte | |
1222 | * values. The distribution can be uniform and counts in all buckets will be | |
1223 | * nearly the same (eg. encrypted data). Unlikely to be compressible. | |
1224 | * | |
1225 | * Other possibility is normal (Gaussian) distribution, where the data could | |
1226 | * be potentially compressible, but we have to take a few more steps to decide | |
1227 | * how much. | |
1228 | * | |
1229 | * @BYTE_CORE_SET_LOW - main part of byte values repeated frequently, | |
1230 | * compression algo can easy fix that | |
1231 | * @BYTE_CORE_SET_HIGH - data have uniform distribution and with high | |
1232 | * probability is not compressible | |
1233 | */ | |
1234 | #define BYTE_CORE_SET_LOW (64) | |
1235 | #define BYTE_CORE_SET_HIGH (200) | |
1236 | ||
1237 | static int byte_core_set_size(struct heuristic_ws *ws) | |
1238 | { | |
1239 | u32 i; | |
1240 | u32 coreset_sum = 0; | |
1241 | const u32 core_set_threshold = ws->sample_size * 90 / 100; | |
1242 | struct bucket_item *bucket = ws->bucket; | |
1243 | ||
1244 | /* Sort in reverse order */ | |
36243c91 | 1245 | radix_sort(ws->bucket, ws->bucket_b, BUCKET_SIZE); |
858177d3 TT |
1246 | |
1247 | for (i = 0; i < BYTE_CORE_SET_LOW; i++) | |
1248 | coreset_sum += bucket[i].count; | |
1249 | ||
1250 | if (coreset_sum > core_set_threshold) | |
1251 | return i; | |
1252 | ||
1253 | for (; i < BYTE_CORE_SET_HIGH && bucket[i].count > 0; i++) { | |
1254 | coreset_sum += bucket[i].count; | |
1255 | if (coreset_sum > core_set_threshold) | |
1256 | break; | |
1257 | } | |
1258 | ||
1259 | return i; | |
1260 | } | |
1261 | ||
a288e92c TT |
1262 | /* |
1263 | * Count byte values in buckets. | |
1264 | * This heuristic can detect textual data (configs, xml, json, html, etc). | |
1265 | * Because in most text-like data byte set is restricted to limited number of | |
1266 | * possible characters, and that restriction in most cases makes data easy to | |
1267 | * compress. | |
1268 | * | |
1269 | * @BYTE_SET_THRESHOLD - consider all data within this byte set size: | |
1270 | * less - compressible | |
1271 | * more - need additional analysis | |
1272 | */ | |
1273 | #define BYTE_SET_THRESHOLD (64) | |
1274 | ||
1275 | static u32 byte_set_size(const struct heuristic_ws *ws) | |
1276 | { | |
1277 | u32 i; | |
1278 | u32 byte_set_size = 0; | |
1279 | ||
1280 | for (i = 0; i < BYTE_SET_THRESHOLD; i++) { | |
1281 | if (ws->bucket[i].count > 0) | |
1282 | byte_set_size++; | |
1283 | } | |
1284 | ||
1285 | /* | |
1286 | * Continue collecting count of byte values in buckets. If the byte | |
1287 | * set size is bigger then the threshold, it's pointless to continue, | |
1288 | * the detection technique would fail for this type of data. | |
1289 | */ | |
1290 | for (; i < BUCKET_SIZE; i++) { | |
1291 | if (ws->bucket[i].count > 0) { | |
1292 | byte_set_size++; | |
1293 | if (byte_set_size > BYTE_SET_THRESHOLD) | |
1294 | return byte_set_size; | |
1295 | } | |
1296 | } | |
1297 | ||
1298 | return byte_set_size; | |
1299 | } | |
1300 | ||
1fe4f6fa TT |
1301 | static bool sample_repeated_patterns(struct heuristic_ws *ws) |
1302 | { | |
1303 | const u32 half_of_sample = ws->sample_size / 2; | |
1304 | const u8 *data = ws->sample; | |
1305 | ||
1306 | return memcmp(&data[0], &data[half_of_sample], half_of_sample) == 0; | |
1307 | } | |
1308 | ||
a440d48c TT |
1309 | static void heuristic_collect_sample(struct inode *inode, u64 start, u64 end, |
1310 | struct heuristic_ws *ws) | |
1311 | { | |
1312 | struct page *page; | |
1313 | u64 index, index_end; | |
1314 | u32 i, curr_sample_pos; | |
1315 | u8 *in_data; | |
1316 | ||
1317 | /* | |
1318 | * Compression handles the input data by chunks of 128KiB | |
1319 | * (defined by BTRFS_MAX_UNCOMPRESSED) | |
1320 | * | |
1321 | * We do the same for the heuristic and loop over the whole range. | |
1322 | * | |
1323 | * MAX_SAMPLE_SIZE - calculated under assumption that heuristic will | |
1324 | * process no more than BTRFS_MAX_UNCOMPRESSED at a time. | |
1325 | */ | |
1326 | if (end - start > BTRFS_MAX_UNCOMPRESSED) | |
1327 | end = start + BTRFS_MAX_UNCOMPRESSED; | |
1328 | ||
1329 | index = start >> PAGE_SHIFT; | |
1330 | index_end = end >> PAGE_SHIFT; | |
1331 | ||
1332 | /* Don't miss unaligned end */ | |
ce394a7f | 1333 | if (!PAGE_ALIGNED(end)) |
a440d48c TT |
1334 | index_end++; |
1335 | ||
1336 | curr_sample_pos = 0; | |
1337 | while (index < index_end) { | |
1338 | page = find_get_page(inode->i_mapping, index); | |
58c1a35c | 1339 | in_data = kmap_local_page(page); |
a440d48c TT |
1340 | /* Handle case where the start is not aligned to PAGE_SIZE */ |
1341 | i = start % PAGE_SIZE; | |
1342 | while (i < PAGE_SIZE - SAMPLING_READ_SIZE) { | |
1343 | /* Don't sample any garbage from the last page */ | |
1344 | if (start > end - SAMPLING_READ_SIZE) | |
1345 | break; | |
1346 | memcpy(&ws->sample[curr_sample_pos], &in_data[i], | |
1347 | SAMPLING_READ_SIZE); | |
1348 | i += SAMPLING_INTERVAL; | |
1349 | start += SAMPLING_INTERVAL; | |
1350 | curr_sample_pos += SAMPLING_READ_SIZE; | |
1351 | } | |
58c1a35c | 1352 | kunmap_local(in_data); |
a440d48c TT |
1353 | put_page(page); |
1354 | ||
1355 | index++; | |
1356 | } | |
1357 | ||
1358 | ws->sample_size = curr_sample_pos; | |
1359 | } | |
1360 | ||
c2fcdcdf TT |
1361 | /* |
1362 | * Compression heuristic. | |
1363 | * | |
1364 | * For now is's a naive and optimistic 'return true', we'll extend the logic to | |
1365 | * quickly (compared to direct compression) detect data characteristics | |
67da05b3 | 1366 | * (compressible/incompressible) to avoid wasting CPU time on incompressible |
c2fcdcdf TT |
1367 | * data. |
1368 | * | |
1369 | * The following types of analysis can be performed: | |
1370 | * - detect mostly zero data | |
1371 | * - detect data with low "byte set" size (text, etc) | |
1372 | * - detect data with low/high "core byte" set | |
1373 | * | |
1374 | * Return non-zero if the compression should be done, 0 otherwise. | |
1375 | */ | |
1376 | int btrfs_compress_heuristic(struct inode *inode, u64 start, u64 end) | |
1377 | { | |
7bf49943 | 1378 | struct list_head *ws_list = get_workspace(0, 0); |
4e439a0b | 1379 | struct heuristic_ws *ws; |
a440d48c TT |
1380 | u32 i; |
1381 | u8 byte; | |
19562430 | 1382 | int ret = 0; |
c2fcdcdf | 1383 | |
4e439a0b TT |
1384 | ws = list_entry(ws_list, struct heuristic_ws, list); |
1385 | ||
a440d48c TT |
1386 | heuristic_collect_sample(inode, start, end, ws); |
1387 | ||
1fe4f6fa TT |
1388 | if (sample_repeated_patterns(ws)) { |
1389 | ret = 1; | |
1390 | goto out; | |
1391 | } | |
1392 | ||
a440d48c TT |
1393 | memset(ws->bucket, 0, sizeof(*ws->bucket)*BUCKET_SIZE); |
1394 | ||
1395 | for (i = 0; i < ws->sample_size; i++) { | |
1396 | byte = ws->sample[i]; | |
1397 | ws->bucket[byte].count++; | |
c2fcdcdf TT |
1398 | } |
1399 | ||
a288e92c TT |
1400 | i = byte_set_size(ws); |
1401 | if (i < BYTE_SET_THRESHOLD) { | |
1402 | ret = 2; | |
1403 | goto out; | |
1404 | } | |
1405 | ||
858177d3 TT |
1406 | i = byte_core_set_size(ws); |
1407 | if (i <= BYTE_CORE_SET_LOW) { | |
1408 | ret = 3; | |
1409 | goto out; | |
1410 | } | |
1411 | ||
1412 | if (i >= BYTE_CORE_SET_HIGH) { | |
1413 | ret = 0; | |
1414 | goto out; | |
1415 | } | |
1416 | ||
19562430 TT |
1417 | i = shannon_entropy(ws); |
1418 | if (i <= ENTROPY_LVL_ACEPTABLE) { | |
1419 | ret = 4; | |
1420 | goto out; | |
1421 | } | |
1422 | ||
1423 | /* | |
1424 | * For the levels below ENTROPY_LVL_HIGH, additional analysis would be | |
1425 | * needed to give green light to compression. | |
1426 | * | |
1427 | * For now just assume that compression at that level is not worth the | |
1428 | * resources because: | |
1429 | * | |
1430 | * 1. it is possible to defrag the data later | |
1431 | * | |
1432 | * 2. the data would turn out to be hardly compressible, eg. 150 byte | |
1433 | * values, every bucket has counter at level ~54. The heuristic would | |
1434 | * be confused. This can happen when data have some internal repeated | |
1435 | * patterns like "abbacbbc...". This can be detected by analyzing | |
1436 | * pairs of bytes, which is too costly. | |
1437 | */ | |
1438 | if (i < ENTROPY_LVL_HIGH) { | |
1439 | ret = 5; | |
1440 | goto out; | |
1441 | } else { | |
1442 | ret = 0; | |
1443 | goto out; | |
1444 | } | |
1445 | ||
1fe4f6fa | 1446 | out: |
929f4baf | 1447 | put_workspace(0, ws_list); |
c2fcdcdf TT |
1448 | return ret; |
1449 | } | |
f51d2b59 | 1450 | |
d0ab62ce DZ |
1451 | /* |
1452 | * Convert the compression suffix (eg. after "zlib" starting with ":") to | |
1453 | * level, unrecognized string will set the default level | |
1454 | */ | |
1455 | unsigned int btrfs_compress_str2level(unsigned int type, const char *str) | |
f51d2b59 | 1456 | { |
d0ab62ce DZ |
1457 | unsigned int level = 0; |
1458 | int ret; | |
1459 | ||
1460 | if (!type) | |
f51d2b59 DS |
1461 | return 0; |
1462 | ||
d0ab62ce DZ |
1463 | if (str[0] == ':') { |
1464 | ret = kstrtouint(str + 1, 10, &level); | |
1465 | if (ret) | |
1466 | level = 0; | |
1467 | } | |
1468 | ||
b0c1fe1e DS |
1469 | level = btrfs_compress_set_level(type, level); |
1470 | ||
1471 | return level; | |
1472 | } |