1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (c) 2013 4 * Phillip Lougher <phillip@squashfs.org.uk> 5 */ 6 7 #include <linux/types.h> 8 #include <linux/mutex.h> 9 #include <linux/slab.h> 10 #include <linux/bio.h> 11 12 #include "squashfs_fs.h" 13 #include "squashfs_fs_sb.h" 14 #include "decompressor.h" 15 #include "squashfs.h" 16 17 /* 18 * This file implements single-threaded decompression in the 19 * decompressor framework 20 */ 21 22 struct squashfs_stream { 23 void *stream; 24 struct mutex mutex; 25 }; 26 27 static void *squashfs_decompressor_create(struct squashfs_sb_info *msblk, 28 void *comp_opts) 29 { 30 struct squashfs_stream *stream; 31 int err = -ENOMEM; 32 33 stream = kmalloc(sizeof(*stream), GFP_KERNEL); 34 if (stream == NULL) 35 goto out; 36 37 stream->stream = msblk->decompressor->init(msblk, comp_opts); 38 if (IS_ERR(stream->stream)) { 39 err = PTR_ERR(stream->stream); 40 goto out; 41 } 42 43 kfree(comp_opts); 44 mutex_init(&stream->mutex); 45 return stream; 46 47 out: 48 kfree(stream); 49 return ERR_PTR(err); 50 } 51 52 static void squashfs_decompressor_destroy(struct squashfs_sb_info *msblk) 53 { 54 struct squashfs_stream *stream = msblk->stream; 55 56 if (stream) { 57 msblk->decompressor->free(stream->stream); 58 kfree(stream); 59 } 60 } 61 62 static int squashfs_decompress(struct squashfs_sb_info *msblk, struct bio *bio, 63 int offset, int length, 64 struct squashfs_page_actor *output) 65 { 66 int res; 67 struct squashfs_stream *stream = msblk->stream; 68 69 mutex_lock(&stream->mutex); 70 res = msblk->decompressor->decompress(msblk, stream->stream, bio, 71 offset, length, output); 72 mutex_unlock(&stream->mutex); 73 74 if (res < 0) 75 ERROR("%s decompression failed, data probably corrupt\n", 76 msblk->decompressor->name); 77 78 return res; 79 } 80 81 static int squashfs_max_decompressors(void) 82 { 83 return 1; 84 } 85 86 const struct squashfs_decompressor_thread_ops squashfs_decompressor_single = { 87 .create = squashfs_decompressor_create, 88 .destroy = squashfs_decompressor_destroy, 89 .decompress = squashfs_decompress, 90 .max_decompressors = squashfs_max_decompressors, 91 }; 92