1 /* 2 * Squashfs - a compressed read only filesystem for Linux 3 * 4 * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 5 * Phillip Lougher <phillip@lougher.demon.co.uk> 6 * 7 * This program is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU General Public License 9 * as published by the Free Software Foundation; either version 2, 10 * or (at your option) any later version. 11 * 12 * This program is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 * GNU General Public License for more details. 16 * 17 * You should have received a copy of the GNU General Public License 18 * along with this program; if not, write to the Free Software 19 * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. 20 * 21 * decompressor.c 22 */ 23 24 #include <linux/types.h> 25 #include <linux/mutex.h> 26 #include <linux/buffer_head.h> 27 28 #include "squashfs_fs.h" 29 #include "squashfs_fs_sb.h" 30 #include "squashfs_fs_i.h" 31 #include "decompressor.h" 32 #include "squashfs.h" 33 34 /* 35 * This file (and decompressor.h) implements a decompressor framework for 36 * Squashfs, allowing multiple decompressors to be easily supported 37 */ 38 39 static const struct squashfs_decompressor squashfs_lzma_unsupported_comp_ops = { 40 NULL, NULL, NULL, LZMA_COMPRESSION, "lzma", 0 41 }; 42 43 #ifndef CONFIG_SQUASHFS_LZO 44 static const struct squashfs_decompressor squashfs_lzo_unsupported_comp_ops = { 45 NULL, NULL, NULL, LZO_COMPRESSION, "lzo", 0 46 }; 47 #endif 48 49 static const struct squashfs_decompressor squashfs_unknown_comp_ops = { 50 NULL, NULL, NULL, 0, "unknown", 0 51 }; 52 53 static const struct squashfs_decompressor *decompressor[] = { 54 &squashfs_zlib_comp_ops, 55 &squashfs_lzma_unsupported_comp_ops, 56 #ifdef CONFIG_SQUASHFS_LZO 57 &squashfs_lzo_comp_ops, 58 #else 59 &squashfs_lzo_unsupported_comp_ops, 60 #endif 61 &squashfs_unknown_comp_ops 62 }; 63 64 65 const struct squashfs_decompressor *squashfs_lookup_decompressor(int id) 66 { 67 int i; 68 69 for (i = 0; decompressor[i]->id; i++) 70 if (id == decompressor[i]->id) 71 break; 72 73 return decompressor[i]; 74 } 75