/* * 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 . * UCRL-CODE-235197 * * This file is part of the SPL, Solaris Porting Layer. * * 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 . * * * 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 #include #include 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(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_KVMEM | KMC_RECLAIMABLE); if (!zlib_workspace_cache) return (-ENOMEM); return (0); } void spl_zlib_fini(void) { kmem_cache_destroy(zlib_workspace_cache); zlib_workspace_cache = NULL; }