Phillip Lougher | 4c0f0bb | 2009-10-06 04:04:15 +0100 | [diff] [blame] | 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> |
Phillip Lougher | b7fc0ff | 2011-02-28 01:45:42 +0000 | [diff] [blame^] | 26 | #include <linux/slab.h> |
Phillip Lougher | 4c0f0bb | 2009-10-06 04:04:15 +0100 | [diff] [blame] | 27 | #include <linux/buffer_head.h> |
| 28 | |
| 29 | #include "squashfs_fs.h" |
| 30 | #include "squashfs_fs_sb.h" |
Phillip Lougher | 4c0f0bb | 2009-10-06 04:04:15 +0100 | [diff] [blame] | 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 | |
Phillip Lougher | dc32567 | 2009-10-14 03:58:11 +0100 | [diff] [blame] | 39 | static const struct squashfs_decompressor squashfs_lzma_unsupported_comp_ops = { |
| 40 | NULL, NULL, NULL, LZMA_COMPRESSION, "lzma", 0 |
| 41 | }; |
| 42 | |
Chan Jeong | 79cb8ce | 2010-08-05 02:29:59 +0100 | [diff] [blame] | 43 | #ifndef CONFIG_SQUASHFS_LZO |
Phillip Lougher | 01a678c | 2011-01-05 18:23:53 +0000 | [diff] [blame] | 44 | static const struct squashfs_decompressor squashfs_lzo_comp_ops = { |
Phillip Lougher | dc32567 | 2009-10-14 03:58:11 +0100 | [diff] [blame] | 45 | NULL, NULL, NULL, LZO_COMPRESSION, "lzo", 0 |
| 46 | }; |
Chan Jeong | 79cb8ce | 2010-08-05 02:29:59 +0100 | [diff] [blame] | 47 | #endif |
Phillip Lougher | dc32567 | 2009-10-14 03:58:11 +0100 | [diff] [blame] | 48 | |
Phillip Lougher | 7a43ae5 | 2010-12-09 02:08:31 +0000 | [diff] [blame] | 49 | #ifndef CONFIG_SQUASHFS_XZ |
| 50 | static const struct squashfs_decompressor squashfs_xz_comp_ops = { |
| 51 | NULL, NULL, NULL, XZ_COMPRESSION, "xz", 0 |
| 52 | }; |
| 53 | #endif |
| 54 | |
Phillip Lougher | 4c0f0bb | 2009-10-06 04:04:15 +0100 | [diff] [blame] | 55 | static const struct squashfs_decompressor squashfs_unknown_comp_ops = { |
| 56 | NULL, NULL, NULL, 0, "unknown", 0 |
| 57 | }; |
| 58 | |
| 59 | static const struct squashfs_decompressor *decompressor[] = { |
| 60 | &squashfs_zlib_comp_ops, |
Chan Jeong | 79cb8ce | 2010-08-05 02:29:59 +0100 | [diff] [blame] | 61 | &squashfs_lzo_comp_ops, |
Phillip Lougher | 7a43ae5 | 2010-12-09 02:08:31 +0000 | [diff] [blame] | 62 | &squashfs_xz_comp_ops, |
Phillip Lougher | 01a678c | 2011-01-05 18:23:53 +0000 | [diff] [blame] | 63 | &squashfs_lzma_unsupported_comp_ops, |
Phillip Lougher | 4c0f0bb | 2009-10-06 04:04:15 +0100 | [diff] [blame] | 64 | &squashfs_unknown_comp_ops |
| 65 | }; |
| 66 | |
| 67 | |
| 68 | const struct squashfs_decompressor *squashfs_lookup_decompressor(int id) |
| 69 | { |
| 70 | int i; |
| 71 | |
| 72 | for (i = 0; decompressor[i]->id; i++) |
| 73 | if (id == decompressor[i]->id) |
| 74 | break; |
| 75 | |
| 76 | return decompressor[i]; |
| 77 | } |
Phillip Lougher | b7fc0ff | 2011-02-28 01:45:42 +0000 | [diff] [blame^] | 78 | |
| 79 | |
| 80 | void *squashfs_decompressor_init(struct super_block *sb, unsigned short flags) |
| 81 | { |
| 82 | struct squashfs_sb_info *msblk = sb->s_fs_info; |
| 83 | void *strm, *buffer = NULL; |
| 84 | int length = 0; |
| 85 | |
| 86 | /* |
| 87 | * Read decompressor specific options from file system if present |
| 88 | */ |
| 89 | if (SQUASHFS_COMP_OPTS(flags)) { |
| 90 | buffer = kmalloc(PAGE_CACHE_SIZE, GFP_KERNEL); |
| 91 | if (buffer == NULL) |
| 92 | return ERR_PTR(-ENOMEM); |
| 93 | |
| 94 | length = squashfs_read_data(sb, &buffer, |
| 95 | sizeof(struct squashfs_super_block), 0, NULL, |
| 96 | PAGE_CACHE_SIZE, 1); |
| 97 | |
| 98 | if (length < 0) { |
| 99 | strm = ERR_PTR(length); |
| 100 | goto finished; |
| 101 | } |
| 102 | } |
| 103 | |
| 104 | strm = msblk->decompressor->init(msblk, buffer, length); |
| 105 | |
| 106 | finished: |
| 107 | kfree(buffer); |
| 108 | |
| 109 | return strm; |
| 110 | } |