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Diffstat (limited to 'module/spl/spl-zlib.c')
| -rw-r--r-- | module/spl/spl-zlib.c | 217 |
1 files changed, 217 insertions, 0 deletions
diff --git a/module/spl/spl-zlib.c b/module/spl/spl-zlib.c new file mode 100644 index 000000000..229e6a44b --- /dev/null +++ b/module/spl/spl-zlib.c @@ -0,0 +1,217 @@ +/* + * Copyright (C) 2007-2010 Lawrence Livermore National Security, LLC. + * Copyright (C) 2007 The Regents of the University of California. + * Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER). + * Written by Brian Behlendorf <[email protected]>. + * UCRL-CODE-235197 + * + * This file is part of the SPL, Solaris Porting Layer. + * For details, see <http://zfsonlinux.org/>. + * + * The SPL is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or (at your + * option) any later version. + * + * The SPL 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 the SPL. If not, see <http://www.gnu.org/licenses/>. + * + * + * z_compress_level/z_uncompress are nearly identical copies of the + * compress2/uncompress functions provided by the official zlib package + * available at http://zlib.net/. The only changes made we to slightly + * adapt the functions called to match the linux kernel implementation + * of zlib. The full zlib license follows: + * + * zlib.h -- interface of the 'zlib' general purpose compression library + * version 1.2.5, April 19th, 2010 + * + * Copyright (C) 1995-2010 Jean-loup Gailly and Mark Adler + * + * This software is provided 'as-is', without any express or implied + * warranty. In no event will the authors be held liable for any damages + * arising from the use of this software. + * + * Permission is granted to anyone to use this software for any purpose, + * including commercial applications, and to alter it and redistribute it + * freely, subject to the following restrictions: + * + * 1. The origin of this software must not be misrepresented; you must not + * claim that you wrote the original software. If you use this software + * in a product, an acknowledgment in the product documentation would be + * appreciated but is not required. + * 2. Altered source versions must be plainly marked as such, and must not be + * misrepresented as being the original software. + * 3. This notice may not be removed or altered from any source distribution. + * + * Jean-loup Gailly + * Mark Adler + */ + + +#include <sys/kmem.h> +#include <sys/kmem_cache.h> +#include <sys/zmod.h> + +static spl_kmem_cache_t *zlib_workspace_cache; + +/* + * A kmem_cache is used for the zlib workspaces to avoid having to vmalloc + * and vfree for every call. Using a kmem_cache also has the advantage + * that improves the odds that the memory used will be local to this cpu. + * To further improve things it might be wise to create a dedicated per-cpu + * workspace for use. This would take some additional care because we then + * must disable preemption around the critical section, and verify that + * zlib_deflate* and zlib_inflate* never internally call schedule(). + */ +static void * +zlib_workspace_alloc(int flags) +{ + return (kmem_cache_alloc(zlib_workspace_cache, flags & ~(__GFP_FS))); +} + +static void +zlib_workspace_free(void *workspace) +{ + kmem_cache_free(zlib_workspace_cache, workspace); +} + +/* + * Compresses the source buffer into the destination buffer. The level + * parameter has the same meaning as in deflateInit. sourceLen is the byte + * length of the source buffer. Upon entry, destLen is the total size of the + * destination buffer, which must be at least 0.1% larger than sourceLen plus + * 12 bytes. Upon exit, destLen is the actual size of the compressed buffer. + * + * compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough + * memory, Z_BUF_ERROR if there was not enough room in the output buffer, + * Z_STREAM_ERROR if the level parameter is invalid. + */ +int +z_compress_level(void *dest, size_t *destLen, const void *source, + size_t sourceLen, int level) +{ + z_stream stream; + int err; + + stream.next_in = (Byte *)source; + stream.avail_in = (uInt)sourceLen; + stream.next_out = dest; + stream.avail_out = (uInt)*destLen; + + if ((size_t)stream.avail_out != *destLen) + return (Z_BUF_ERROR); + + stream.workspace = zlib_workspace_alloc(KM_SLEEP); + if (!stream.workspace) + return (Z_MEM_ERROR); + + err = zlib_deflateInit(&stream, level); + if (err != Z_OK) { + zlib_workspace_free(stream.workspace); + return (err); + } + + err = zlib_deflate(&stream, Z_FINISH); + if (err != Z_STREAM_END) { + zlib_deflateEnd(&stream); + zlib_workspace_free(stream.workspace); + return (err == Z_OK ? Z_BUF_ERROR : err); + } + *destLen = stream.total_out; + + err = zlib_deflateEnd(&stream); + zlib_workspace_free(stream.workspace); + + return (err); +} +EXPORT_SYMBOL(z_compress_level); + +/* + * Decompresses the source buffer into the destination buffer. sourceLen is + * the byte length of the source buffer. Upon entry, destLen is the total + * size of the destination buffer, which must be large enough to hold the + * entire uncompressed data. (The size of the uncompressed data must have + * been saved previously by the compressor and transmitted to the decompressor + * by some mechanism outside the scope of this compression library.) + * Upon exit, destLen is the actual size of the compressed buffer. + * This function can be used to decompress a whole file at once if the + * input file is mmap'ed. + * + * uncompress returns Z_OK if success, Z_MEM_ERROR if there was not + * enough memory, Z_BUF_ERROR if there was not enough room in the output + * buffer, or Z_DATA_ERROR if the input data was corrupted. + */ +int +z_uncompress(void *dest, size_t *destLen, const void *source, size_t sourceLen) +{ + z_stream stream; + int err; + + stream.next_in = (Byte *)source; + stream.avail_in = (uInt)sourceLen; + stream.next_out = dest; + stream.avail_out = (uInt)*destLen; + + if ((size_t)stream.avail_out != *destLen) + return (Z_BUF_ERROR); + + stream.workspace = zlib_workspace_alloc(KM_SLEEP); + if (!stream.workspace) + return (Z_MEM_ERROR); + + err = zlib_inflateInit(&stream); + if (err != Z_OK) { + zlib_workspace_free(stream.workspace); + return (err); + } + + err = zlib_inflate(&stream, Z_FINISH); + if (err != Z_STREAM_END) { + zlib_inflateEnd(&stream); + zlib_workspace_free(stream.workspace); + + if (err == Z_NEED_DICT || + (err == Z_BUF_ERROR && stream.avail_in == 0)) + return (Z_DATA_ERROR); + + return (err); + } + *destLen = stream.total_out; + + err = zlib_inflateEnd(&stream); + zlib_workspace_free(stream.workspace); + + return (err); +} +EXPORT_SYMBOL(z_uncompress); + +int +spl_zlib_init(void) +{ + int size; + + size = MAX(spl_zlib_deflate_workspacesize(MAX_WBITS, MAX_MEM_LEVEL), + zlib_inflate_workspacesize()); + + zlib_workspace_cache = kmem_cache_create( + "spl_zlib_workspace_cache", + size, 0, NULL, NULL, NULL, NULL, NULL, + KMC_VMEM | KMC_NOEMERGENCY); + if (!zlib_workspace_cache) + return (1); + + return (0); +} + +void +spl_zlib_fini(void) +{ + kmem_cache_destroy(zlib_workspace_cache); + zlib_workspace_cache = NULL; +} |