1e6a6d379SPhillip Lougher /* 2e6a6d379SPhillip Lougher * Squashfs - a compressed read only filesystem for Linux 3e6a6d379SPhillip Lougher * 4e6a6d379SPhillip Lougher * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 5d7f2ff67SPhillip Lougher * Phillip Lougher <phillip@squashfs.org.uk> 6e6a6d379SPhillip Lougher * 7e6a6d379SPhillip Lougher * This program is free software; you can redistribute it and/or 8e6a6d379SPhillip Lougher * modify it under the terms of the GNU General Public License 9e6a6d379SPhillip Lougher * as published by the Free Software Foundation; either version 2, 10e6a6d379SPhillip Lougher * or (at your option) any later version. 11e6a6d379SPhillip Lougher * 12e6a6d379SPhillip Lougher * This program is distributed in the hope that it will be useful, 13e6a6d379SPhillip Lougher * but WITHOUT ANY WARRANTY; without even the implied warranty of 14e6a6d379SPhillip Lougher * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15e6a6d379SPhillip Lougher * GNU General Public License for more details. 16e6a6d379SPhillip Lougher * 17e6a6d379SPhillip Lougher * You should have received a copy of the GNU General Public License 18e6a6d379SPhillip Lougher * along with this program; if not, write to the Free Software 19e6a6d379SPhillip Lougher * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. 20e6a6d379SPhillip Lougher * 21e6a6d379SPhillip Lougher * zlib_wrapper.c 22e6a6d379SPhillip Lougher */ 23e6a6d379SPhillip Lougher 24e6a6d379SPhillip Lougher 25e6a6d379SPhillip Lougher #include <linux/mutex.h> 26e6a6d379SPhillip Lougher #include <linux/buffer_head.h> 275a0e3ad6STejun Heo #include <linux/slab.h> 28e6a6d379SPhillip Lougher #include <linux/zlib.h> 29117a91e0SPhillip Lougher #include <linux/vmalloc.h> 30e6a6d379SPhillip Lougher 31e6a6d379SPhillip Lougher #include "squashfs_fs.h" 32e6a6d379SPhillip Lougher #include "squashfs_fs_sb.h" 33e6a6d379SPhillip Lougher #include "squashfs.h" 344c0f0bb2SPhillip Lougher #include "decompressor.h" 35846b730eSPhillip Lougher #include "page_actor.h" 36e6a6d379SPhillip Lougher 379508c6b9SPhillip Lougher static void *zlib_init(struct squashfs_sb_info *dummy, void *buff) 38f1a40359SPhillip Lougher { 39f1a40359SPhillip Lougher z_stream *stream = kmalloc(sizeof(z_stream), GFP_KERNEL); 40f1a40359SPhillip Lougher if (stream == NULL) 41f1a40359SPhillip Lougher goto failed; 42117a91e0SPhillip Lougher stream->workspace = vmalloc(zlib_inflate_workspacesize()); 43f1a40359SPhillip Lougher if (stream->workspace == NULL) 44f1a40359SPhillip Lougher goto failed; 45f1a40359SPhillip Lougher 46f1a40359SPhillip Lougher return stream; 47f1a40359SPhillip Lougher 48f1a40359SPhillip Lougher failed: 49f1a40359SPhillip Lougher ERROR("Failed to allocate zlib workspace\n"); 50f1a40359SPhillip Lougher kfree(stream); 51b7fc0ff0SPhillip Lougher return ERR_PTR(-ENOMEM); 52f1a40359SPhillip Lougher } 53f1a40359SPhillip Lougher 54f1a40359SPhillip Lougher 554c0f0bb2SPhillip Lougher static void zlib_free(void *strm) 56f1a40359SPhillip Lougher { 57f1a40359SPhillip Lougher z_stream *stream = strm; 58f1a40359SPhillip Lougher 59f1a40359SPhillip Lougher if (stream) 60117a91e0SPhillip Lougher vfree(stream->workspace); 61f1a40359SPhillip Lougher kfree(stream); 62f1a40359SPhillip Lougher } 63f1a40359SPhillip Lougher 64f1a40359SPhillip Lougher 659508c6b9SPhillip Lougher static int zlib_uncompress(struct squashfs_sb_info *msblk, void *strm, 66846b730eSPhillip Lougher struct buffer_head **bh, int b, int offset, int length, 67846b730eSPhillip Lougher struct squashfs_page_actor *output) 68e6a6d379SPhillip Lougher { 69846b730eSPhillip Lougher int zlib_err, zlib_init = 0, k = 0; 709508c6b9SPhillip Lougher z_stream *stream = strm; 71e6a6d379SPhillip Lougher 72846b730eSPhillip Lougher stream->avail_out = PAGE_CACHE_SIZE; 73846b730eSPhillip Lougher stream->next_out = squashfs_first_page(output); 74f1a40359SPhillip Lougher stream->avail_in = 0; 75e6a6d379SPhillip Lougher 76e6a6d379SPhillip Lougher do { 77f1a40359SPhillip Lougher if (stream->avail_in == 0 && k < b) { 78170cf021SPhillip Lougher int avail = min(length, msblk->devblksize - offset); 79170cf021SPhillip Lougher length -= avail; 80f1a40359SPhillip Lougher stream->next_in = bh[k]->b_data + offset; 81f1a40359SPhillip Lougher stream->avail_in = avail; 82e6a6d379SPhillip Lougher offset = 0; 83e6a6d379SPhillip Lougher } 84e6a6d379SPhillip Lougher 85846b730eSPhillip Lougher if (stream->avail_out == 0) { 86846b730eSPhillip Lougher stream->next_out = squashfs_next_page(output); 87846b730eSPhillip Lougher if (stream->next_out != NULL) 88f1a40359SPhillip Lougher stream->avail_out = PAGE_CACHE_SIZE; 89e6a6d379SPhillip Lougher } 90e6a6d379SPhillip Lougher 91e6a6d379SPhillip Lougher if (!zlib_init) { 92f1a40359SPhillip Lougher zlib_err = zlib_inflateInit(stream); 93846b730eSPhillip Lougher if (zlib_err != Z_OK) { 94846b730eSPhillip Lougher squashfs_finish_page(output); 959508c6b9SPhillip Lougher goto out; 96846b730eSPhillip Lougher } 97e6a6d379SPhillip Lougher zlib_init = 1; 98e6a6d379SPhillip Lougher } 99e6a6d379SPhillip Lougher 100f1a40359SPhillip Lougher zlib_err = zlib_inflate(stream, Z_SYNC_FLUSH); 101e6a6d379SPhillip Lougher 102f1a40359SPhillip Lougher if (stream->avail_in == 0 && k < b) 103e6a6d379SPhillip Lougher put_bh(bh[k++]); 104e6a6d379SPhillip Lougher } while (zlib_err == Z_OK); 105e6a6d379SPhillip Lougher 106846b730eSPhillip Lougher squashfs_finish_page(output); 107846b730eSPhillip Lougher 1089508c6b9SPhillip Lougher if (zlib_err != Z_STREAM_END) 1099508c6b9SPhillip Lougher goto out; 110e6a6d379SPhillip Lougher 111f1a40359SPhillip Lougher zlib_err = zlib_inflateEnd(stream); 1129508c6b9SPhillip Lougher if (zlib_err != Z_OK) 1139508c6b9SPhillip Lougher goto out; 114e6a6d379SPhillip Lougher 1159508c6b9SPhillip Lougher if (k < b) 1169508c6b9SPhillip Lougher goto out; 117e7ee11f0SPhillip Lougher 1189508c6b9SPhillip Lougher return stream->total_out; 119e6a6d379SPhillip Lougher 1209508c6b9SPhillip Lougher out: 121e6a6d379SPhillip Lougher for (; k < b; k++) 122e6a6d379SPhillip Lougher put_bh(bh[k]); 123e6a6d379SPhillip Lougher 124e6a6d379SPhillip Lougher return -EIO; 125e6a6d379SPhillip Lougher } 1264c0f0bb2SPhillip Lougher 1274c0f0bb2SPhillip Lougher const struct squashfs_decompressor squashfs_zlib_comp_ops = { 1284c0f0bb2SPhillip Lougher .init = zlib_init, 1294c0f0bb2SPhillip Lougher .free = zlib_free, 1304c0f0bb2SPhillip Lougher .decompress = zlib_uncompress, 1314c0f0bb2SPhillip Lougher .id = ZLIB_COMPRESSION, 1324c0f0bb2SPhillip Lougher .name = "zlib", 1334c0f0bb2SPhillip Lougher .supported = 1 1344c0f0bb2SPhillip Lougher }; 1354c0f0bb2SPhillip Lougher 136