1 /* 2 * Copyright (c) 2013 3 * Phillip Lougher <phillip@squashfs.org.uk> 4 * 5 * This work is licensed under the terms of the GNU GPL, version 2. See 6 * the COPYING file in the top-level directory. 7 */ 8 9 #include <linux/types.h> 10 #include <linux/mutex.h> 11 #include <linux/slab.h> 12 #include <linux/buffer_head.h> 13 14 #include "squashfs_fs.h" 15 #include "squashfs_fs_sb.h" 16 #include "decompressor.h" 17 #include "squashfs.h" 18 19 /* 20 * This file implements single-threaded decompression in the 21 * decompressor framework 22 */ 23 24 struct squashfs_stream { 25 void *stream; 26 struct mutex mutex; 27 }; 28 29 void *squashfs_decompressor_create(struct squashfs_sb_info *msblk, 30 void *comp_opts) 31 { 32 struct squashfs_stream *stream; 33 int err = -ENOMEM; 34 35 stream = kmalloc(sizeof(*stream), GFP_KERNEL); 36 if (stream == NULL) 37 goto out; 38 39 stream->stream = msblk->decompressor->init(msblk, comp_opts); 40 if (IS_ERR(stream->stream)) { 41 err = PTR_ERR(stream->stream); 42 goto out; 43 } 44 45 kfree(comp_opts); 46 mutex_init(&stream->mutex); 47 return stream; 48 49 out: 50 kfree(stream); 51 return ERR_PTR(err); 52 } 53 54 void squashfs_decompressor_destroy(struct squashfs_sb_info *msblk) 55 { 56 struct squashfs_stream *stream = msblk->stream; 57 58 if (stream) { 59 msblk->decompressor->free(stream->stream); 60 kfree(stream); 61 } 62 } 63 64 int squashfs_decompress(struct squashfs_sb_info *msblk, struct buffer_head **bh, 65 int b, int offset, int length, struct squashfs_page_actor *output) 66 { 67 int res; 68 struct squashfs_stream *stream = msblk->stream; 69 70 mutex_lock(&stream->mutex); 71 res = msblk->decompressor->decompress(msblk, stream->stream, bh, b, 72 offset, length, output); 73 mutex_unlock(&stream->mutex); 74 75 if (res < 0) 76 ERROR("%s decompression failed, data probably corrupt\n", 77 msblk->decompressor->name); 78 79 return res; 80 } 81 82 int squashfs_max_decompressors(void) 83 { 84 return 1; 85 } 86