compress.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * This file is part of UBIFS.
  4 *
  5 * Copyright (C) 2006-2008 Nokia Corporation.
  6 * Copyright (C) 2006, 2007 University of Szeged, Hungary
  7 *
  8 * Authors: Adrian Hunter
  9 *          Artem Bityutskiy (Битюцкий Артём)
 10 *          Zoltan Sogor
 11 */
 12
 13/*
 14 * This file provides a single place to access to compression and
 15 * decompression.
 16 */
 17
 18#include <crypto/acompress.h>
 19#include <linux/highmem.h>
 20#include "ubifs.h"
 21
 22union ubifs_in_ptr {
 23	const void *buf;
 24	struct folio *folio;
 25};
 26
 27/* Fake description object for the "none" compressor */
 28static struct ubifs_compressor none_compr = {
 29	.compr_type = UBIFS_COMPR_NONE,
 30	.name = "none",
 31	.capi_name = "",
 32};
 33
 34#ifdef CONFIG_UBIFS_FS_LZO
 35static struct ubifs_compressor lzo_compr = {
 36	.compr_type = UBIFS_COMPR_LZO,
 37	.name = "lzo",
 38	.capi_name = "lzo",
 39};
 40#else
 41static struct ubifs_compressor lzo_compr = {
 42	.compr_type = UBIFS_COMPR_LZO,
 43	.name = "lzo",
 44};
 45#endif
 46
 47#ifdef CONFIG_UBIFS_FS_ZLIB
 48static struct ubifs_compressor zlib_compr = {
 49	.compr_type = UBIFS_COMPR_ZLIB,
 50	.name = "zlib",
 51	.capi_name = "deflate",
 52};
 53#else
 54static struct ubifs_compressor zlib_compr = {
 55	.compr_type = UBIFS_COMPR_ZLIB,
 56	.name = "zlib",
 57};
 58#endif
 59
 60#ifdef CONFIG_UBIFS_FS_ZSTD
 61static struct ubifs_compressor zstd_compr = {
 62	.compr_type = UBIFS_COMPR_ZSTD,
 63	.name = "zstd",
 64	.capi_name = "zstd",
 65};
 66#else
 67static struct ubifs_compressor zstd_compr = {
 68	.compr_type = UBIFS_COMPR_ZSTD,
 69	.name = "zstd",
 70};
 71#endif
 72
 73/* All UBIFS compressors */
 74struct ubifs_compressor *ubifs_compressors[UBIFS_COMPR_TYPES_CNT];
 75
 76static void ubifs_compress_common(int *compr_type, union ubifs_in_ptr in_ptr,
 77				  size_t in_offset, int in_len, bool in_folio,
 78				  void *out_buf, int *out_len)
 79{
 80	struct ubifs_compressor *compr = ubifs_compressors[*compr_type];
 81	int dlen = *out_len;
 82	int err;
 83
 84	if (*compr_type == UBIFS_COMPR_NONE)
 85		goto no_compr;
 86
 87	/* If the input data is small, do not even try to compress it */
 88	if (in_len < UBIFS_MIN_COMPR_LEN)
 89		goto no_compr;
 90
 91	dlen = min(dlen, in_len - UBIFS_MIN_COMPRESS_DIFF);
 92
 93	do {
 94		ACOMP_REQUEST_ON_STACK(req, compr->cc);
 95		DECLARE_CRYPTO_WAIT(wait);
 96
 97		acomp_request_set_callback(req, 0, NULL, NULL);
 98		if (in_folio)
 99			acomp_request_set_src_folio(req, in_ptr.folio,
100						    in_offset, in_len);
101		else
102			acomp_request_set_src_dma(req, in_ptr.buf, in_len);
103		acomp_request_set_dst_dma(req, out_buf, dlen);
104		err = crypto_acomp_compress(req);
105		dlen = req->dlen;
106		if (err != -EAGAIN)
107			break;
108
109		req = ACOMP_REQUEST_CLONE(req, GFP_NOFS | __GFP_NOWARN);
110		acomp_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
111					   crypto_req_done, &wait);
112		err = crypto_acomp_compress(req);
113		err = crypto_wait_req(err, &wait);
114		dlen = req->dlen;
115		acomp_request_free(req);
116	} while (0);
117
118	*out_len = dlen;
119	if (err)
120		goto no_compr;
121
122	return;
123
124no_compr:
125	if (in_folio)
126		memcpy_from_folio(out_buf, in_ptr.folio, in_offset, in_len);
127	else
128		memcpy(out_buf, in_ptr.buf, in_len);
129	*out_len = in_len;
130	*compr_type = UBIFS_COMPR_NONE;
131}
132
133/**
134 * ubifs_compress - compress data.
135 * @c: UBIFS file-system description object
136 * @in_buf: data to compress
137 * @in_len: length of the data to compress
138 * @out_buf: output buffer where compressed data should be stored
139 * @out_len: output buffer length is returned here
140 * @compr_type: type of compression to use on enter, actually used compression
141 *              type on exit
142 *
143 * This function compresses input buffer @in_buf of length @in_len and stores
144 * the result in the output buffer @out_buf and the resulting length in
145 * @out_len. If the input buffer does not compress, it is just copied to the
146 * @out_buf. The same happens if @compr_type is %UBIFS_COMPR_NONE or if
147 * compression error occurred.
148 *
149 * Note, if the input buffer was not compressed, it is copied to the output
150 * buffer and %UBIFS_COMPR_NONE is returned in @compr_type.
151 */
152void ubifs_compress(const struct ubifs_info *c, const void *in_buf,
153		    int in_len, void *out_buf, int *out_len, int *compr_type)
154{
155	union ubifs_in_ptr in_ptr = { .buf = in_buf };
156
157	ubifs_compress_common(compr_type, in_ptr, 0, in_len, false,
158			      out_buf, out_len);
159}
160
161/**
162 * ubifs_compress_folio - compress folio.
163 * @c: UBIFS file-system description object
164 * @in_folio: data to compress
165 * @in_offset: offset into @in_folio
166 * @in_len: length of the data to compress
167 * @out_buf: output buffer where compressed data should be stored
168 * @out_len: output buffer length is returned here
169 * @compr_type: type of compression to use on enter, actually used compression
170 *              type on exit
171 *
172 * This function compresses input folio @in_folio of length @in_len and
173 * stores the result in the output buffer @out_buf and the resulting length
174 * in @out_len. If the input buffer does not compress, it is just copied
175 * to the @out_buf. The same happens if @compr_type is %UBIFS_COMPR_NONE
176 * or if compression error occurred.
177 *
178 * Note, if the input buffer was not compressed, it is copied to the output
179 * buffer and %UBIFS_COMPR_NONE is returned in @compr_type.
180 */
181void ubifs_compress_folio(const struct ubifs_info *c, struct folio *in_folio,
182			  size_t in_offset, int in_len, void *out_buf,
183			  int *out_len, int *compr_type)
184{
185	union ubifs_in_ptr in_ptr = { .folio = in_folio };
186
187	ubifs_compress_common(compr_type, in_ptr, in_offset, in_len, true,
188			      out_buf, out_len);
189}
190
191static int ubifs_decompress_common(const struct ubifs_info *c,
192				   const void *in_buf, int in_len,
193				   void *out_ptr, size_t out_offset,
194				   int *out_len, bool out_folio,
195				   int compr_type)
196{
197	struct ubifs_compressor *compr;
198	int dlen = *out_len;
199	int err;
200
201	if (unlikely(compr_type < 0 || compr_type >= UBIFS_COMPR_TYPES_CNT)) {
202		ubifs_err(c, "invalid compression type %d", compr_type);
203		return -EINVAL;
204	}
205
206	compr = ubifs_compressors[compr_type];
207
208	if (unlikely(!compr->capi_name)) {
209		ubifs_err(c, "%s compression is not compiled in", compr->name);
210		return -EINVAL;
211	}
212
213	if (compr_type == UBIFS_COMPR_NONE) {
214		if (out_folio)
215			memcpy_to_folio(out_ptr, out_offset, in_buf, in_len);
216		else
217			memcpy(out_ptr, in_buf, in_len);
218		*out_len = in_len;
219		return 0;
220	}
221
222	do {
223		ACOMP_REQUEST_ON_STACK(req, compr->cc);
224		DECLARE_CRYPTO_WAIT(wait);
225
226		acomp_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
227					   crypto_req_done, &wait);
228		acomp_request_set_src_dma(req, in_buf, in_len);
229		if (out_folio)
230			acomp_request_set_dst_folio(req, out_ptr, out_offset,
231						    dlen);
232		else
233			acomp_request_set_dst_dma(req, out_ptr, dlen);
234		err = crypto_acomp_decompress(req);
235		dlen = req->dlen;
236		if (err != -EAGAIN)
237			break;
238
239		req = ACOMP_REQUEST_CLONE(req, GFP_NOFS | __GFP_NOWARN);
240		err = crypto_acomp_decompress(req);
241		err = crypto_wait_req(err, &wait);
242		dlen = req->dlen;
243		acomp_request_free(req);
244	} while (0);
245
246	*out_len = dlen;
247	if (err)
248		ubifs_err(c, "cannot decompress %d bytes, compressor %s, error %d",
249			  in_len, compr->name, err);
250
251	return err;
252}
253
254/**
255 * ubifs_decompress - decompress data.
256 * @c: UBIFS file-system description object
257 * @in_buf: data to decompress
258 * @in_len: length of the data to decompress
259 * @out_buf: output buffer where decompressed data should
260 * @out_len: output length is returned here
261 * @compr_type: type of compression
262 *
263 * This function decompresses data from buffer @in_buf into buffer @out_buf.
264 * The length of the uncompressed data is returned in @out_len. This functions
265 * returns %0 on success or a negative error code on failure.
266 */
267int ubifs_decompress(const struct ubifs_info *c, const void *in_buf,
268		     int in_len, void *out_buf, int *out_len, int compr_type)
269{
270	return ubifs_decompress_common(c, in_buf, in_len, out_buf, 0, out_len,
271				       false, compr_type);
272}
273
274/**
275 * ubifs_decompress_folio - decompress folio.
276 * @c: UBIFS file-system description object
277 * @in_buf: data to decompress
278 * @in_len: length of the data to decompress
279 * @out_folio: output folio where decompressed data should
280 * @out_offset: offset into @out_folio
281 * @out_len: output length is returned here
282 * @compr_type: type of compression
283 *
284 * This function decompresses data from buffer @in_buf into folio
285 * @out_folio.  The length of the uncompressed data is returned in
286 * @out_len.  This functions returns %0 on success or a negative error
287 * code on failure.
288 */
289int ubifs_decompress_folio(const struct ubifs_info *c, const void *in_buf,
290			   int in_len, struct folio *out_folio,
291			   size_t out_offset, int *out_len, int compr_type)
292{
293	return ubifs_decompress_common(c, in_buf, in_len, out_folio,
294				       out_offset, out_len, true, compr_type);
295}
296
297/**
298 * compr_init - initialize a compressor.
299 * @compr: compressor description object
300 *
301 * This function initializes the requested compressor and returns zero in case
302 * of success or a negative error code in case of failure.
303 */
304static int __init compr_init(struct ubifs_compressor *compr)
305{
306	if (compr->capi_name) {
307		compr->cc = crypto_alloc_acomp(compr->capi_name, 0, 0);
308		if (IS_ERR(compr->cc)) {
309			pr_err("UBIFS error (pid %d): cannot initialize compressor %s, error %ld",
310			       current->pid, compr->name, PTR_ERR(compr->cc));
311			return PTR_ERR(compr->cc);
312		}
313	}
314
315	ubifs_compressors[compr->compr_type] = compr;
316	return 0;
317}
318
319/**
320 * compr_exit - de-initialize a compressor.
321 * @compr: compressor description object
322 */
323static void compr_exit(struct ubifs_compressor *compr)
324{
325	if (compr->capi_name)
326		crypto_free_acomp(compr->cc);
327}
328
329/**
330 * ubifs_compressors_init - initialize UBIFS compressors.
331 *
332 * This function initializes the compressor which were compiled in. Returns
333 * zero in case of success and a negative error code in case of failure.
334 */
335int __init ubifs_compressors_init(void)
336{
337	int err;
338
339	err = compr_init(&lzo_compr);
340	if (err)
341		return err;
342
343	err = compr_init(&zstd_compr);
344	if (err)
345		goto out_lzo;
346
347	err = compr_init(&zlib_compr);
348	if (err)
349		goto out_zstd;
350
351	ubifs_compressors[UBIFS_COMPR_NONE] = &none_compr;
352	return 0;
353
354out_zstd:
355	compr_exit(&zstd_compr);
356out_lzo:
357	compr_exit(&lzo_compr);
358	return err;
359}
360
361/**
362 * ubifs_compressors_exit - de-initialize UBIFS compressors.
363 */
364void ubifs_compressors_exit(void)
365{
366	compr_exit(&lzo_compr);
367	compr_exit(&zlib_compr);
368	compr_exit(&zstd_compr);
369}