cregit-Linux how code gets into the kernel

Release 4.10 fs/ubifs/compress.c

Directory: fs/ubifs
/*
 * This file is part of UBIFS.
 *
 * Copyright (C) 2006-2008 Nokia Corporation.
 * Copyright (C) 2006, 2007 University of Szeged, Hungary
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc., 51
 * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 *
 * Authors: Adrian Hunter
 *          Artem Bityutskiy (Битюцкий Артём)
 *          Zoltan Sogor
 */

/*
 * This file provides a single place to access to compression and
 * decompression.
 */

#include <linux/crypto.h>
#include "ubifs.h"

/* Fake description object for the "none" compressor */

static struct ubifs_compressor none_compr = {
	.compr_type = UBIFS_COMPR_NONE,
	.name = "none",
	.capi_name = "",
};

#ifdef CONFIG_UBIFS_FS_LZO
static DEFINE_MUTEX(lzo_mutex);


static struct ubifs_compressor lzo_compr = {
	.compr_type = UBIFS_COMPR_LZO,
	.comp_mutex = &lzo_mutex,
	.name = "lzo",
	.capi_name = "lzo",
};
#else

static struct ubifs_compressor lzo_compr = {
	.compr_type = UBIFS_COMPR_LZO,
	.name = "lzo",
};
#endif

#ifdef CONFIG_UBIFS_FS_ZLIB
static DEFINE_MUTEX(deflate_mutex);
static DEFINE_MUTEX(inflate_mutex);


static struct ubifs_compressor zlib_compr = {
	.compr_type = UBIFS_COMPR_ZLIB,
	.comp_mutex = &deflate_mutex,
	.decomp_mutex = &inflate_mutex,
	.name = "zlib",
	.capi_name = "deflate",
};
#else

static struct ubifs_compressor zlib_compr = {
	.compr_type = UBIFS_COMPR_ZLIB,
	.name = "zlib",
};
#endif

/* All UBIFS compressors */

struct ubifs_compressor *ubifs_compressors[UBIFS_COMPR_TYPES_CNT];

/**
 * ubifs_compress - compress data.
 * @in_buf: data to compress
 * @in_len: length of the data to compress
 * @out_buf: output buffer where compressed data should be stored
 * @out_len: output buffer length is returned here
 * @compr_type: type of compression to use on enter, actually used compression
 *              type on exit
 *
 * This function compresses input buffer @in_buf of length @in_len and stores
 * the result in the output buffer @out_buf and the resulting length in
 * @out_len. If the input buffer does not compress, it is just copied to the
 * @out_buf. The same happens if @compr_type is %UBIFS_COMPR_NONE or if
 * compression error occurred.
 *
 * Note, if the input buffer was not compressed, it is copied to the output
 * buffer and %UBIFS_COMPR_NONE is returned in @compr_type.
 */

void ubifs_compress(const struct ubifs_info *c, const void *in_buf, int in_len, void *out_buf, int *out_len, int *compr_type) { int err; struct ubifs_compressor *compr = ubifs_compressors[*compr_type]; if (*compr_type == UBIFS_COMPR_NONE) goto no_compr; /* If the input data is small, do not even try to compress it */ if (in_len < UBIFS_MIN_COMPR_LEN) goto no_compr; if (compr->comp_mutex) mutex_lock(compr->comp_mutex); err = crypto_comp_compress(compr->cc, in_buf, in_len, out_buf, (unsigned int *)out_len); if (compr->comp_mutex) mutex_unlock(compr->comp_mutex); if (unlikely(err)) { ubifs_warn(c, "cannot compress %d bytes, compressor %s, error %d, leave data uncompressed", in_len, compr->name, err); goto no_compr; } /* * If the data compressed only slightly, it is better to leave it * uncompressed to improve read speed. */ if (in_len - *out_len < UBIFS_MIN_COMPRESS_DIFF) goto no_compr; return; no_compr: memcpy(out_buf, in_buf, in_len); *out_len = in_len; *compr_type = UBIFS_COMPR_NONE; }

Contributors

PersonTokensPropCommitsCommitProp
artem bityutskiyartem bityutskiy16795.43%480.00%
sheng yongsheng yong84.57%120.00%
Total175100.00%5100.00%

/** * ubifs_decompress - decompress data. * @in_buf: data to decompress * @in_len: length of the data to decompress * @out_buf: output buffer where decompressed data should * @out_len: output length is returned here * @compr_type: type of compression * * This function decompresses data from buffer @in_buf into buffer @out_buf. * The length of the uncompressed data is returned in @out_len. This functions * returns %0 on success or a negative error code on failure. */
int ubifs_decompress(const struct ubifs_info *c, const void *in_buf, int in_len, void *out_buf, int *out_len, int compr_type) { int err; struct ubifs_compressor *compr; if (unlikely(compr_type < 0 || compr_type >= UBIFS_COMPR_TYPES_CNT)) { ubifs_err(c, "invalid compression type %d", compr_type); return -EINVAL; } compr = ubifs_compressors[compr_type]; if (unlikely(!compr->capi_name)) { ubifs_err(c, "%s compression is not compiled in", compr->name); return -EINVAL; } if (compr_type == UBIFS_COMPR_NONE) { memcpy(out_buf, in_buf, in_len); *out_len = in_len; return 0; } if (compr->decomp_mutex) mutex_lock(compr->decomp_mutex); err = crypto_comp_decompress(compr->cc, in_buf, in_len, out_buf, (unsigned int *)out_len); if (compr->decomp_mutex) mutex_unlock(compr->decomp_mutex); if (err) ubifs_err(c, "cannot decompress %d bytes, compressor %s, error %d", in_len, compr->name, err); return err; }

Contributors

PersonTokensPropCommitsCommitProp
artem bityutskiyartem bityutskiy18393.85%375.00%
sheng yongsheng yong126.15%125.00%
Total195100.00%4100.00%

/** * compr_init - initialize a compressor. * @compr: compressor description object * * This function initializes the requested compressor and returns zero in case * of success or a negative error code in case of failure. */
static int __init compr_init(struct ubifs_compressor *compr) { if (compr->capi_name) { compr->cc = crypto_alloc_comp(compr->capi_name, 0, 0); if (IS_ERR(compr->cc)) { pr_err("UBIFS error (pid %d): cannot initialize compressor %s, error %ld", current->pid, compr->name, PTR_ERR(compr->cc)); return PTR_ERR(compr->cc); } } ubifs_compressors[compr->compr_type] = compr; return 0; }

Contributors

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artem bityutskiyartem bityutskiy8093.02%150.00%
sheng yongsheng yong66.98%150.00%
Total86100.00%2100.00%

/** * compr_exit - de-initialize a compressor. * @compr: compressor description object */
static void compr_exit(struct ubifs_compressor *compr) { if (compr->capi_name) crypto_free_comp(compr->cc); return; }

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artem bityutskiyartem bityutskiy25100.00%1100.00%
Total25100.00%1100.00%

/** * ubifs_compressors_init - initialize UBIFS compressors. * * This function initializes the compressor which were compiled in. Returns * zero in case of success and a negative error code in case of failure. */
int __init ubifs_compressors_init(void) { int err; err = compr_init(&lzo_compr); if (err) return err; err = compr_init(&zlib_compr); if (err) goto out_lzo; ubifs_compressors[UBIFS_COMPR_NONE] = &none_compr; return 0; out_lzo: compr_exit(&lzo_compr); return err; }

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artem bityutskiyartem bityutskiy63100.00%1100.00%
Total63100.00%1100.00%

/** * ubifs_compressors_exit - de-initialize UBIFS compressors. */
void ubifs_compressors_exit(void) { compr_exit(&lzo_compr); compr_exit(&zlib_compr); }

Contributors

PersonTokensPropCommitsCommitProp
artem bityutskiyartem bityutskiy19100.00%1100.00%
Total19100.00%1100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
artem bityutskiyartem bityutskiy71096.34%571.43%
sheng yongsheng yong263.53%114.29%
geert uytterhoevengeert uytterhoeven10.14%114.29%
Total737100.00%7100.00%
Directory: fs/ubifs
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