| Phillip Lougher | e6a6d37 | 2009-09-22 19:25:24 +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 | * zlib_wrapper.c |
| 22 | */ |
| 23 | |
| 24 | |
| 25 | #include <linux/mutex.h> |
| 26 | #include <linux/buffer_head.h> |
| 27 | #include <linux/zlib.h> |
| 28 | |
| 29 | #include "squashfs_fs.h" |
| 30 | #include "squashfs_fs_sb.h" |
| 31 | #include "squashfs_fs_i.h" |
| 32 | #include "squashfs.h" |
| 33 | |
| 34 | int squashfs_zlib_uncompress(struct squashfs_sb_info *msblk, void **buffer, |
| 35 | struct buffer_head **bh, int b, int offset, int length, int srclength, |
| 36 | int pages) |
| 37 | { |
| 38 | int zlib_err = 0, zlib_init = 0; |
| 39 | int avail, bytes, k = 0, page = 0; |
| 40 | |
| 41 | mutex_lock(&msblk->read_data_mutex); |
| 42 | |
| 43 | msblk->stream.avail_out = 0; |
| 44 | msblk->stream.avail_in = 0; |
| 45 | |
| 46 | bytes = length; |
| 47 | do { |
| 48 | if (msblk->stream.avail_in == 0 && k < b) { |
| 49 | avail = min(bytes, msblk->devblksize - offset); |
| 50 | bytes -= avail; |
| 51 | wait_on_buffer(bh[k]); |
| 52 | if (!buffer_uptodate(bh[k])) |
| 53 | goto release_mutex; |
| 54 | |
| 55 | if (avail == 0) { |
| 56 | offset = 0; |
| 57 | put_bh(bh[k++]); |
| 58 | continue; |
| 59 | } |
| 60 | |
| 61 | msblk->stream.next_in = bh[k]->b_data + offset; |
| 62 | msblk->stream.avail_in = avail; |
| 63 | offset = 0; |
| 64 | } |
| 65 | |
| 66 | if (msblk->stream.avail_out == 0 && page < pages) { |
| 67 | msblk->stream.next_out = buffer[page++]; |
| 68 | msblk->stream.avail_out = PAGE_CACHE_SIZE; |
| 69 | } |
| 70 | |
| 71 | if (!zlib_init) { |
| 72 | zlib_err = zlib_inflateInit(&msblk->stream); |
| 73 | if (zlib_err != Z_OK) { |
| 74 | ERROR("zlib_inflateInit returned unexpected " |
| 75 | "result 0x%x, srclength %d\n", |
| 76 | zlib_err, srclength); |
| 77 | goto release_mutex; |
| 78 | } |
| 79 | zlib_init = 1; |
| 80 | } |
| 81 | |
| 82 | zlib_err = zlib_inflate(&msblk->stream, Z_SYNC_FLUSH); |
| 83 | |
| 84 | if (msblk->stream.avail_in == 0 && k < b) |
| 85 | put_bh(bh[k++]); |
| 86 | } while (zlib_err == Z_OK); |
| 87 | |
| 88 | if (zlib_err != Z_STREAM_END) { |
| 89 | ERROR("zlib_inflate error, data probably corrupt\n"); |
| 90 | goto release_mutex; |
| 91 | } |
| 92 | |
| 93 | zlib_err = zlib_inflateEnd(&msblk->stream); |
| 94 | if (zlib_err != Z_OK) { |
| 95 | ERROR("zlib_inflate error, data probably corrupt\n"); |
| 96 | goto release_mutex; |
| 97 | } |
| 98 | |
| 99 | mutex_unlock(&msblk->read_data_mutex); |
| 100 | return msblk->stream.total_out; |
| 101 | |
| 102 | release_mutex: |
| 103 | mutex_unlock(&msblk->read_data_mutex); |
| 104 | |
| 105 | for (; k < b; k++) |
| 106 | put_bh(bh[k]); |
| 107 | |
| 108 | return -EIO; |
| 109 | } |