xref: /linux/fs/bcachefs/compress.c (revision 5027ec19f1049a07df5b0a37b1f462514cf2724b)
1 // SPDX-License-Identifier: GPL-2.0
2 #include "bcachefs.h"
3 #include "checksum.h"
4 #include "compress.h"
5 #include "extents.h"
6 #include "super-io.h"
7 
8 #include <linux/lz4.h>
9 #include <linux/zlib.h>
10 #include <linux/zstd.h>
11 
12 /* Bounce buffer: */
13 struct bbuf {
14 	void		*b;
15 	enum {
16 		BB_NONE,
17 		BB_VMAP,
18 		BB_KMALLOC,
19 		BB_MEMPOOL,
20 	}		type;
21 	int		rw;
22 };
23 
24 static struct bbuf __bounce_alloc(struct bch_fs *c, unsigned size, int rw)
25 {
26 	void *b;
27 
28 	BUG_ON(size > c->opts.encoded_extent_max);
29 
30 	b = kmalloc(size, GFP_NOFS|__GFP_NOWARN);
31 	if (b)
32 		return (struct bbuf) { .b = b, .type = BB_KMALLOC, .rw = rw };
33 
34 	b = mempool_alloc(&c->compression_bounce[rw], GFP_NOFS);
35 	if (b)
36 		return (struct bbuf) { .b = b, .type = BB_MEMPOOL, .rw = rw };
37 
38 	BUG();
39 }
40 
41 static bool bio_phys_contig(struct bio *bio, struct bvec_iter start)
42 {
43 	struct bio_vec bv;
44 	struct bvec_iter iter;
45 	void *expected_start = NULL;
46 
47 	__bio_for_each_bvec(bv, bio, iter, start) {
48 		if (expected_start &&
49 		    expected_start != page_address(bv.bv_page) + bv.bv_offset)
50 			return false;
51 
52 		expected_start = page_address(bv.bv_page) +
53 			bv.bv_offset + bv.bv_len;
54 	}
55 
56 	return true;
57 }
58 
59 static struct bbuf __bio_map_or_bounce(struct bch_fs *c, struct bio *bio,
60 				       struct bvec_iter start, int rw)
61 {
62 	struct bbuf ret;
63 	struct bio_vec bv;
64 	struct bvec_iter iter;
65 	unsigned nr_pages = 0;
66 	struct page *stack_pages[16];
67 	struct page **pages = NULL;
68 	void *data;
69 
70 	BUG_ON(start.bi_size > c->opts.encoded_extent_max);
71 
72 	if (!PageHighMem(bio_iter_page(bio, start)) &&
73 	    bio_phys_contig(bio, start))
74 		return (struct bbuf) {
75 			.b = page_address(bio_iter_page(bio, start)) +
76 				bio_iter_offset(bio, start),
77 			.type = BB_NONE, .rw = rw
78 		};
79 
80 	/* check if we can map the pages contiguously: */
81 	__bio_for_each_segment(bv, bio, iter, start) {
82 		if (iter.bi_size != start.bi_size &&
83 		    bv.bv_offset)
84 			goto bounce;
85 
86 		if (bv.bv_len < iter.bi_size &&
87 		    bv.bv_offset + bv.bv_len < PAGE_SIZE)
88 			goto bounce;
89 
90 		nr_pages++;
91 	}
92 
93 	BUG_ON(DIV_ROUND_UP(start.bi_size, PAGE_SIZE) > nr_pages);
94 
95 	pages = nr_pages > ARRAY_SIZE(stack_pages)
96 		? kmalloc_array(nr_pages, sizeof(struct page *), GFP_NOFS)
97 		: stack_pages;
98 	if (!pages)
99 		goto bounce;
100 
101 	nr_pages = 0;
102 	__bio_for_each_segment(bv, bio, iter, start)
103 		pages[nr_pages++] = bv.bv_page;
104 
105 	data = vmap(pages, nr_pages, VM_MAP, PAGE_KERNEL);
106 	if (pages != stack_pages)
107 		kfree(pages);
108 
109 	if (data)
110 		return (struct bbuf) {
111 			.b = data + bio_iter_offset(bio, start),
112 			.type = BB_VMAP, .rw = rw
113 		};
114 bounce:
115 	ret = __bounce_alloc(c, start.bi_size, rw);
116 
117 	if (rw == READ)
118 		memcpy_from_bio(ret.b, bio, start);
119 
120 	return ret;
121 }
122 
123 static struct bbuf bio_map_or_bounce(struct bch_fs *c, struct bio *bio, int rw)
124 {
125 	return __bio_map_or_bounce(c, bio, bio->bi_iter, rw);
126 }
127 
128 static void bio_unmap_or_unbounce(struct bch_fs *c, struct bbuf buf)
129 {
130 	switch (buf.type) {
131 	case BB_NONE:
132 		break;
133 	case BB_VMAP:
134 		vunmap((void *) ((unsigned long) buf.b & PAGE_MASK));
135 		break;
136 	case BB_KMALLOC:
137 		kfree(buf.b);
138 		break;
139 	case BB_MEMPOOL:
140 		mempool_free(buf.b, &c->compression_bounce[buf.rw]);
141 		break;
142 	}
143 }
144 
145 static inline void zlib_set_workspace(z_stream *strm, void *workspace)
146 {
147 #ifdef __KERNEL__
148 	strm->workspace = workspace;
149 #endif
150 }
151 
152 static int __bio_uncompress(struct bch_fs *c, struct bio *src,
153 			    void *dst_data, struct bch_extent_crc_unpacked crc)
154 {
155 	struct bbuf src_data = { NULL };
156 	size_t src_len = src->bi_iter.bi_size;
157 	size_t dst_len = crc.uncompressed_size << 9;
158 	void *workspace;
159 	int ret;
160 
161 	src_data = bio_map_or_bounce(c, src, READ);
162 
163 	switch (crc.compression_type) {
164 	case BCH_COMPRESSION_TYPE_lz4_old:
165 	case BCH_COMPRESSION_TYPE_lz4:
166 		ret = LZ4_decompress_safe_partial(src_data.b, dst_data,
167 						  src_len, dst_len, dst_len);
168 		if (ret != dst_len)
169 			goto err;
170 		break;
171 	case BCH_COMPRESSION_TYPE_gzip: {
172 		z_stream strm = {
173 			.next_in	= src_data.b,
174 			.avail_in	= src_len,
175 			.next_out	= dst_data,
176 			.avail_out	= dst_len,
177 		};
178 
179 		workspace = mempool_alloc(&c->decompress_workspace, GFP_NOFS);
180 
181 		zlib_set_workspace(&strm, workspace);
182 		zlib_inflateInit2(&strm, -MAX_WBITS);
183 		ret = zlib_inflate(&strm, Z_FINISH);
184 
185 		mempool_free(workspace, &c->decompress_workspace);
186 
187 		if (ret != Z_STREAM_END)
188 			goto err;
189 		break;
190 	}
191 	case BCH_COMPRESSION_TYPE_zstd: {
192 		ZSTD_DCtx *ctx;
193 		size_t real_src_len = le32_to_cpup(src_data.b);
194 
195 		if (real_src_len > src_len - 4)
196 			goto err;
197 
198 		workspace = mempool_alloc(&c->decompress_workspace, GFP_NOFS);
199 		ctx = zstd_init_dctx(workspace, zstd_dctx_workspace_bound());
200 
201 		ret = zstd_decompress_dctx(ctx,
202 				dst_data,	dst_len,
203 				src_data.b + 4, real_src_len);
204 
205 		mempool_free(workspace, &c->decompress_workspace);
206 
207 		if (ret != dst_len)
208 			goto err;
209 		break;
210 	}
211 	default:
212 		BUG();
213 	}
214 	ret = 0;
215 out:
216 	bio_unmap_or_unbounce(c, src_data);
217 	return ret;
218 err:
219 	ret = -EIO;
220 	goto out;
221 }
222 
223 int bch2_bio_uncompress_inplace(struct bch_fs *c, struct bio *bio,
224 				struct bch_extent_crc_unpacked *crc)
225 {
226 	struct bbuf data = { NULL };
227 	size_t dst_len = crc->uncompressed_size << 9;
228 
229 	/* bio must own its pages: */
230 	BUG_ON(!bio->bi_vcnt);
231 	BUG_ON(DIV_ROUND_UP(crc->live_size, PAGE_SECTORS) > bio->bi_max_vecs);
232 
233 	if (crc->uncompressed_size << 9	> c->opts.encoded_extent_max ||
234 	    crc->compressed_size << 9	> c->opts.encoded_extent_max) {
235 		bch_err(c, "error rewriting existing data: extent too big");
236 		return -EIO;
237 	}
238 
239 	data = __bounce_alloc(c, dst_len, WRITE);
240 
241 	if (__bio_uncompress(c, bio, data.b, *crc)) {
242 		if (!c->opts.no_data_io)
243 			bch_err(c, "error rewriting existing data: decompression error");
244 		bio_unmap_or_unbounce(c, data);
245 		return -EIO;
246 	}
247 
248 	/*
249 	 * XXX: don't have a good way to assert that the bio was allocated with
250 	 * enough space, we depend on bch2_move_extent doing the right thing
251 	 */
252 	bio->bi_iter.bi_size = crc->live_size << 9;
253 
254 	memcpy_to_bio(bio, bio->bi_iter, data.b + (crc->offset << 9));
255 
256 	crc->csum_type		= 0;
257 	crc->compression_type	= 0;
258 	crc->compressed_size	= crc->live_size;
259 	crc->uncompressed_size	= crc->live_size;
260 	crc->offset		= 0;
261 	crc->csum		= (struct bch_csum) { 0, 0 };
262 
263 	bio_unmap_or_unbounce(c, data);
264 	return 0;
265 }
266 
267 int bch2_bio_uncompress(struct bch_fs *c, struct bio *src,
268 		       struct bio *dst, struct bvec_iter dst_iter,
269 		       struct bch_extent_crc_unpacked crc)
270 {
271 	struct bbuf dst_data = { NULL };
272 	size_t dst_len = crc.uncompressed_size << 9;
273 	int ret;
274 
275 	if (crc.uncompressed_size << 9	> c->opts.encoded_extent_max ||
276 	    crc.compressed_size << 9	> c->opts.encoded_extent_max)
277 		return -EIO;
278 
279 	dst_data = dst_len == dst_iter.bi_size
280 		? __bio_map_or_bounce(c, dst, dst_iter, WRITE)
281 		: __bounce_alloc(c, dst_len, WRITE);
282 
283 	ret = __bio_uncompress(c, src, dst_data.b, crc);
284 	if (ret)
285 		goto err;
286 
287 	if (dst_data.type != BB_NONE &&
288 	    dst_data.type != BB_VMAP)
289 		memcpy_to_bio(dst, dst_iter, dst_data.b + (crc.offset << 9));
290 err:
291 	bio_unmap_or_unbounce(c, dst_data);
292 	return ret;
293 }
294 
295 static int attempt_compress(struct bch_fs *c,
296 			    void *workspace,
297 			    void *dst, size_t dst_len,
298 			    void *src, size_t src_len,
299 			    struct bch_compression_opt compression)
300 {
301 	enum bch_compression_type compression_type =
302 		__bch2_compression_opt_to_type[compression.type];
303 
304 	switch (compression_type) {
305 	case BCH_COMPRESSION_TYPE_lz4:
306 		if (compression.level < LZ4HC_MIN_CLEVEL) {
307 			int len = src_len;
308 			int ret = LZ4_compress_destSize(
309 					src,		dst,
310 					&len,		dst_len,
311 					workspace);
312 			if (len < src_len)
313 				return -len;
314 
315 			return ret;
316 		} else {
317 			int ret = LZ4_compress_HC(
318 					src,		dst,
319 					src_len,	dst_len,
320 					compression.level,
321 					workspace);
322 
323 			return ret ?: -1;
324 		}
325 	case BCH_COMPRESSION_TYPE_gzip: {
326 		z_stream strm = {
327 			.next_in	= src,
328 			.avail_in	= src_len,
329 			.next_out	= dst,
330 			.avail_out	= dst_len,
331 		};
332 
333 		zlib_set_workspace(&strm, workspace);
334 		zlib_deflateInit2(&strm,
335 				  compression.level
336 				  ? clamp_t(unsigned, compression.level,
337 					    Z_BEST_SPEED, Z_BEST_COMPRESSION)
338 				  : Z_DEFAULT_COMPRESSION,
339 				  Z_DEFLATED, -MAX_WBITS, DEF_MEM_LEVEL,
340 				  Z_DEFAULT_STRATEGY);
341 
342 		if (zlib_deflate(&strm, Z_FINISH) != Z_STREAM_END)
343 			return 0;
344 
345 		if (zlib_deflateEnd(&strm) != Z_OK)
346 			return 0;
347 
348 		return strm.total_out;
349 	}
350 	case BCH_COMPRESSION_TYPE_zstd: {
351 		/*
352 		 * rescale:
353 		 * zstd max compression level is 22, our max level is 15
354 		 */
355 		unsigned level = min((compression.level * 3) / 2, zstd_max_clevel());
356 		ZSTD_parameters params = zstd_get_params(level, c->opts.encoded_extent_max);
357 		ZSTD_CCtx *ctx = zstd_init_cctx(workspace,
358 			zstd_cctx_workspace_bound(&params.cParams));
359 
360 		/*
361 		 * ZSTD requires that when we decompress we pass in the exact
362 		 * compressed size - rounding it up to the nearest sector
363 		 * doesn't work, so we use the first 4 bytes of the buffer for
364 		 * that.
365 		 *
366 		 * Additionally, the ZSTD code seems to have a bug where it will
367 		 * write just past the end of the buffer - so subtract a fudge
368 		 * factor (7 bytes) from the dst buffer size to account for
369 		 * that.
370 		 */
371 		size_t len = zstd_compress_cctx(ctx,
372 				dst + 4,	dst_len - 4 - 7,
373 				src,		src_len,
374 				&c->zstd_params);
375 		if (zstd_is_error(len))
376 			return 0;
377 
378 		*((__le32 *) dst) = cpu_to_le32(len);
379 		return len + 4;
380 	}
381 	default:
382 		BUG();
383 	}
384 }
385 
386 static unsigned __bio_compress(struct bch_fs *c,
387 			       struct bio *dst, size_t *dst_len,
388 			       struct bio *src, size_t *src_len,
389 			       struct bch_compression_opt compression)
390 {
391 	struct bbuf src_data = { NULL }, dst_data = { NULL };
392 	void *workspace;
393 	enum bch_compression_type compression_type =
394 		__bch2_compression_opt_to_type[compression.type];
395 	unsigned pad;
396 	int ret = 0;
397 
398 	BUG_ON(compression_type >= BCH_COMPRESSION_TYPE_NR);
399 	BUG_ON(!mempool_initialized(&c->compress_workspace[compression_type]));
400 
401 	/* If it's only one block, don't bother trying to compress: */
402 	if (src->bi_iter.bi_size <= c->opts.block_size)
403 		return BCH_COMPRESSION_TYPE_incompressible;
404 
405 	dst_data = bio_map_or_bounce(c, dst, WRITE);
406 	src_data = bio_map_or_bounce(c, src, READ);
407 
408 	workspace = mempool_alloc(&c->compress_workspace[compression_type], GFP_NOFS);
409 
410 	*src_len = src->bi_iter.bi_size;
411 	*dst_len = dst->bi_iter.bi_size;
412 
413 	/*
414 	 * XXX: this algorithm sucks when the compression code doesn't tell us
415 	 * how much would fit, like LZ4 does:
416 	 */
417 	while (1) {
418 		if (*src_len <= block_bytes(c)) {
419 			ret = -1;
420 			break;
421 		}
422 
423 		ret = attempt_compress(c, workspace,
424 				       dst_data.b,	*dst_len,
425 				       src_data.b,	*src_len,
426 				       compression);
427 		if (ret > 0) {
428 			*dst_len = ret;
429 			ret = 0;
430 			break;
431 		}
432 
433 		/* Didn't fit: should we retry with a smaller amount?  */
434 		if (*src_len <= *dst_len) {
435 			ret = -1;
436 			break;
437 		}
438 
439 		/*
440 		 * If ret is negative, it's a hint as to how much data would fit
441 		 */
442 		BUG_ON(-ret >= *src_len);
443 
444 		if (ret < 0)
445 			*src_len = -ret;
446 		else
447 			*src_len -= (*src_len - *dst_len) / 2;
448 		*src_len = round_down(*src_len, block_bytes(c));
449 	}
450 
451 	mempool_free(workspace, &c->compress_workspace[compression_type]);
452 
453 	if (ret)
454 		goto err;
455 
456 	/* Didn't get smaller: */
457 	if (round_up(*dst_len, block_bytes(c)) >= *src_len)
458 		goto err;
459 
460 	pad = round_up(*dst_len, block_bytes(c)) - *dst_len;
461 
462 	memset(dst_data.b + *dst_len, 0, pad);
463 	*dst_len += pad;
464 
465 	if (dst_data.type != BB_NONE &&
466 	    dst_data.type != BB_VMAP)
467 		memcpy_to_bio(dst, dst->bi_iter, dst_data.b);
468 
469 	BUG_ON(!*dst_len || *dst_len > dst->bi_iter.bi_size);
470 	BUG_ON(!*src_len || *src_len > src->bi_iter.bi_size);
471 	BUG_ON(*dst_len & (block_bytes(c) - 1));
472 	BUG_ON(*src_len & (block_bytes(c) - 1));
473 	ret = compression_type;
474 out:
475 	bio_unmap_or_unbounce(c, src_data);
476 	bio_unmap_or_unbounce(c, dst_data);
477 	return ret;
478 err:
479 	ret = BCH_COMPRESSION_TYPE_incompressible;
480 	goto out;
481 }
482 
483 unsigned bch2_bio_compress(struct bch_fs *c,
484 			   struct bio *dst, size_t *dst_len,
485 			   struct bio *src, size_t *src_len,
486 			   unsigned compression_opt)
487 {
488 	unsigned orig_dst = dst->bi_iter.bi_size;
489 	unsigned orig_src = src->bi_iter.bi_size;
490 	unsigned compression_type;
491 
492 	/* Don't consume more than BCH_ENCODED_EXTENT_MAX from @src: */
493 	src->bi_iter.bi_size = min_t(unsigned, src->bi_iter.bi_size,
494 				     c->opts.encoded_extent_max);
495 	/* Don't generate a bigger output than input: */
496 	dst->bi_iter.bi_size = min(dst->bi_iter.bi_size, src->bi_iter.bi_size);
497 
498 	compression_type =
499 		__bio_compress(c, dst, dst_len, src, src_len,
500 			       bch2_compression_decode(compression_opt));
501 
502 	dst->bi_iter.bi_size = orig_dst;
503 	src->bi_iter.bi_size = orig_src;
504 	return compression_type;
505 }
506 
507 static int __bch2_fs_compress_init(struct bch_fs *, u64);
508 
509 #define BCH_FEATURE_none	0
510 
511 static const unsigned bch2_compression_opt_to_feature[] = {
512 #define x(t, n) [BCH_COMPRESSION_OPT_##t] = BCH_FEATURE_##t,
513 	BCH_COMPRESSION_OPTS()
514 #undef x
515 };
516 
517 #undef BCH_FEATURE_none
518 
519 static int __bch2_check_set_has_compressed_data(struct bch_fs *c, u64 f)
520 {
521 	int ret = 0;
522 
523 	if ((c->sb.features & f) == f)
524 		return 0;
525 
526 	mutex_lock(&c->sb_lock);
527 
528 	if ((c->sb.features & f) == f) {
529 		mutex_unlock(&c->sb_lock);
530 		return 0;
531 	}
532 
533 	ret = __bch2_fs_compress_init(c, c->sb.features|f);
534 	if (ret) {
535 		mutex_unlock(&c->sb_lock);
536 		return ret;
537 	}
538 
539 	c->disk_sb.sb->features[0] |= cpu_to_le64(f);
540 	bch2_write_super(c);
541 	mutex_unlock(&c->sb_lock);
542 
543 	return 0;
544 }
545 
546 int bch2_check_set_has_compressed_data(struct bch_fs *c,
547 				       unsigned compression_opt)
548 {
549 	unsigned compression_type = bch2_compression_decode(compression_opt).type;
550 
551 	BUG_ON(compression_type >= ARRAY_SIZE(bch2_compression_opt_to_feature));
552 
553 	return compression_type
554 		? __bch2_check_set_has_compressed_data(c,
555 				1ULL << bch2_compression_opt_to_feature[compression_type])
556 		: 0;
557 }
558 
559 void bch2_fs_compress_exit(struct bch_fs *c)
560 {
561 	unsigned i;
562 
563 	mempool_exit(&c->decompress_workspace);
564 	for (i = 0; i < ARRAY_SIZE(c->compress_workspace); i++)
565 		mempool_exit(&c->compress_workspace[i]);
566 	mempool_exit(&c->compression_bounce[WRITE]);
567 	mempool_exit(&c->compression_bounce[READ]);
568 }
569 
570 static int __bch2_fs_compress_init(struct bch_fs *c, u64 features)
571 {
572 	size_t decompress_workspace_size = 0;
573 	ZSTD_parameters params = zstd_get_params(zstd_max_clevel(),
574 						 c->opts.encoded_extent_max);
575 	struct {
576 		unsigned			feature;
577 		enum bch_compression_type	type;
578 		size_t				compress_workspace;
579 		size_t				decompress_workspace;
580 	} compression_types[] = {
581 		{ BCH_FEATURE_lz4, BCH_COMPRESSION_TYPE_lz4,
582 			max_t(size_t, LZ4_MEM_COMPRESS, LZ4HC_MEM_COMPRESS),
583 			0 },
584 		{ BCH_FEATURE_gzip, BCH_COMPRESSION_TYPE_gzip,
585 			zlib_deflate_workspacesize(MAX_WBITS, DEF_MEM_LEVEL),
586 			zlib_inflate_workspacesize(), },
587 		{ BCH_FEATURE_zstd, BCH_COMPRESSION_TYPE_zstd,
588 			zstd_cctx_workspace_bound(&params.cParams),
589 			zstd_dctx_workspace_bound() },
590 	}, *i;
591 	bool have_compressed = false;
592 
593 	c->zstd_params = params;
594 
595 	for (i = compression_types;
596 	     i < compression_types + ARRAY_SIZE(compression_types);
597 	     i++)
598 		have_compressed |= (features & (1 << i->feature)) != 0;
599 
600 	if (!have_compressed)
601 		return 0;
602 
603 	if (!mempool_initialized(&c->compression_bounce[READ]) &&
604 	    mempool_init_kvpmalloc_pool(&c->compression_bounce[READ],
605 					1, c->opts.encoded_extent_max))
606 		return -BCH_ERR_ENOMEM_compression_bounce_read_init;
607 
608 	if (!mempool_initialized(&c->compression_bounce[WRITE]) &&
609 	    mempool_init_kvpmalloc_pool(&c->compression_bounce[WRITE],
610 					1, c->opts.encoded_extent_max))
611 		return -BCH_ERR_ENOMEM_compression_bounce_write_init;
612 
613 	for (i = compression_types;
614 	     i < compression_types + ARRAY_SIZE(compression_types);
615 	     i++) {
616 		decompress_workspace_size =
617 			max(decompress_workspace_size, i->decompress_workspace);
618 
619 		if (!(features & (1 << i->feature)))
620 			continue;
621 
622 		if (mempool_initialized(&c->compress_workspace[i->type]))
623 			continue;
624 
625 		if (mempool_init_kvpmalloc_pool(
626 				&c->compress_workspace[i->type],
627 				1, i->compress_workspace))
628 			return -BCH_ERR_ENOMEM_compression_workspace_init;
629 	}
630 
631 	if (!mempool_initialized(&c->decompress_workspace) &&
632 	    mempool_init_kvpmalloc_pool(&c->decompress_workspace,
633 					1, decompress_workspace_size))
634 		return -BCH_ERR_ENOMEM_decompression_workspace_init;
635 
636 	return 0;
637 }
638 
639 static u64 compression_opt_to_feature(unsigned v)
640 {
641 	unsigned type = bch2_compression_decode(v).type;
642 
643 	return BIT_ULL(bch2_compression_opt_to_feature[type]);
644 }
645 
646 int bch2_fs_compress_init(struct bch_fs *c)
647 {
648 	u64 f = c->sb.features;
649 
650 	f |= compression_opt_to_feature(c->opts.compression);
651 	f |= compression_opt_to_feature(c->opts.background_compression);
652 
653 	return __bch2_fs_compress_init(c, f);
654 }
655 
656 int bch2_opt_compression_parse(struct bch_fs *c, const char *_val, u64 *res,
657 			       struct printbuf *err)
658 {
659 	char *val = kstrdup(_val, GFP_KERNEL);
660 	char *p = val, *type_str, *level_str;
661 	struct bch_compression_opt opt = { 0 };
662 	int ret;
663 
664 	if (!val)
665 		return -ENOMEM;
666 
667 	type_str = strsep(&p, ":");
668 	level_str = p;
669 
670 	ret = match_string(bch2_compression_opts, -1, type_str);
671 	if (ret < 0 && err)
672 		prt_str(err, "invalid compression type");
673 	if (ret < 0)
674 		goto err;
675 
676 	opt.type = ret;
677 
678 	if (level_str) {
679 		unsigned level;
680 
681 		ret = kstrtouint(level_str, 10, &level);
682 		if (!ret && !opt.type && level)
683 			ret = -EINVAL;
684 		if (!ret && level > 15)
685 			ret = -EINVAL;
686 		if (ret < 0 && err)
687 			prt_str(err, "invalid compression level");
688 		if (ret < 0)
689 			goto err;
690 
691 		opt.level = level;
692 	}
693 
694 	*res = bch2_compression_encode(opt);
695 err:
696 	kfree(val);
697 	return ret;
698 }
699 
700 void bch2_compression_opt_to_text(struct printbuf *out, u64 v)
701 {
702 	struct bch_compression_opt opt = bch2_compression_decode(v);
703 
704 	if (opt.type < BCH_COMPRESSION_OPT_NR)
705 		prt_str(out, bch2_compression_opts[opt.type]);
706 	else
707 		prt_printf(out, "(unknown compression opt %u)", opt.type);
708 	if (opt.level)
709 		prt_printf(out, ":%u", opt.level);
710 }
711 
712 void bch2_opt_compression_to_text(struct printbuf *out,
713 				  struct bch_fs *c,
714 				  struct bch_sb *sb,
715 				  u64 v)
716 {
717 	return bch2_compression_opt_to_text(out, v);
718 }
719 
720 int bch2_opt_compression_validate(u64 v, struct printbuf *err)
721 {
722 	if (!bch2_compression_opt_valid(v)) {
723 		prt_printf(err, "invalid compression opt %llu", v);
724 		return -BCH_ERR_invalid_sb_opt_compression;
725 	}
726 
727 	return 0;
728 }
729