1 /* 2 * Squashfs - a compressed read only filesystem for Linux 3 * 4 * Copyright (c) 2010 LG Electronics 5 * Chan Jeong <chan.jeong@lge.com> 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 * lzo_wrapper.c 22 */ 23 24 #include <linux/mutex.h> 25 #include <linux/buffer_head.h> 26 #include <linux/slab.h> 27 #include <linux/vmalloc.h> 28 #include <linux/lzo.h> 29 30 #include "squashfs_fs.h" 31 #include "squashfs_fs_sb.h" 32 #include "squashfs_fs_i.h" 33 #include "squashfs.h" 34 #include "decompressor.h" 35 36 struct squashfs_lzo { 37 void *input; 38 void *output; 39 }; 40 41 static void *lzo_init(struct squashfs_sb_info *msblk) 42 { 43 int block_size = max_t(int, msblk->block_size, SQUASHFS_METADATA_SIZE); 44 45 struct squashfs_lzo *stream = kzalloc(sizeof(*stream), GFP_KERNEL); 46 if (stream == NULL) 47 goto failed; 48 stream->input = vmalloc(block_size); 49 if (stream->input == NULL) 50 goto failed; 51 stream->output = vmalloc(block_size); 52 if (stream->output == NULL) 53 goto failed2; 54 55 return stream; 56 57 failed2: 58 vfree(stream->input); 59 failed: 60 ERROR("Failed to allocate lzo workspace\n"); 61 kfree(stream); 62 return NULL; 63 } 64 65 66 static void lzo_free(void *strm) 67 { 68 struct squashfs_lzo *stream = strm; 69 70 if (stream) { 71 vfree(stream->input); 72 vfree(stream->output); 73 } 74 kfree(stream); 75 } 76 77 78 static int lzo_uncompress(struct squashfs_sb_info *msblk, void **buffer, 79 struct buffer_head **bh, int b, int offset, int length, int srclength, 80 int pages) 81 { 82 struct squashfs_lzo *stream = msblk->stream; 83 void *buff = stream->input; 84 int avail, i, bytes = length, res; 85 size_t out_len = srclength; 86 87 mutex_lock(&msblk->read_data_mutex); 88 89 for (i = 0; i < b; i++) { 90 wait_on_buffer(bh[i]); 91 if (!buffer_uptodate(bh[i])) 92 goto block_release; 93 94 avail = min(bytes, msblk->devblksize - offset); 95 memcpy(buff, bh[i]->b_data + offset, avail); 96 buff += avail; 97 bytes -= avail; 98 offset = 0; 99 put_bh(bh[i]); 100 } 101 102 res = lzo1x_decompress_safe(stream->input, (size_t)length, 103 stream->output, &out_len); 104 if (res != LZO_E_OK) 105 goto failed; 106 107 res = bytes = (int)out_len; 108 for (i = 0, buff = stream->output; bytes && i < pages; i++) { 109 avail = min_t(int, bytes, PAGE_CACHE_SIZE); 110 memcpy(buffer[i], buff, avail); 111 buff += avail; 112 bytes -= avail; 113 } 114 115 mutex_unlock(&msblk->read_data_mutex); 116 return res; 117 118 block_release: 119 for (; i < b; i++) 120 put_bh(bh[i]); 121 122 failed: 123 mutex_unlock(&msblk->read_data_mutex); 124 125 ERROR("lzo decompression failed, data probably corrupt\n"); 126 return -EIO; 127 } 128 129 const struct squashfs_decompressor squashfs_lzo_comp_ops = { 130 .init = lzo_init, 131 .free = lzo_free, 132 .decompress = lzo_uncompress, 133 .id = LZO_COMPRESSION, 134 .name = "lzo", 135 .supported = 1 136 }; 137