/* * Copyright (c) 2013 * Phillip Lougher <phillip@squashfs.org.uk> * * This work is licensed under the terms of the GNU GPL, version 2. See * the COPYING file in the top-level directory. */ #include <linux/types.h>#include <linux/slab.h>#include <linux/percpu.h>#include <linux/buffer_head.h> #include "squashfs_fs.h"#include "squashfs_fs_sb.h"#include "decompressor.h"#include "squashfs.h" /* * This file implements multi-threaded decompression using percpu * variables, one thread per cpu core. */ struct squashfs_stream {	void		*stream;}; void *squashfs_decompressor_create(struct squashfs_sb_info *msblk,						void *comp_opts){	struct squashfs_stream *stream;	struct squashfs_stream __percpu *percpu;	int err, cpu; 	percpu = alloc_percpu(struct squashfs_stream);	if (percpu == NULL)		return ERR_PTR(-ENOMEM); 	for_each_possible_cpu(cpu) {		stream = per_cpu_ptr(percpu, cpu);		stream->stream = msblk->decompressor->init(msblk, comp_opts);		if (IS_ERR(stream->stream)) {			err = PTR_ERR(stream->stream);			goto out;		}	} 	kfree(comp_opts);	return (__force void *) percpu; out:	for_each_possible_cpu(cpu) {		stream = per_cpu_ptr(percpu, cpu);		if (!IS_ERR_OR_NULL(stream->stream))			msblk->decompressor->free(stream->stream);	}	free_percpu(percpu);	return ERR_PTR(err);} void squashfs_decompressor_destroy(struct squashfs_sb_info *msblk){	struct squashfs_stream __percpu *percpu =			(struct squashfs_stream __percpu *) msblk->stream;	struct squashfs_stream *stream;	int cpu; 	if (msblk->stream) {		for_each_possible_cpu(cpu) {			stream = per_cpu_ptr(percpu, cpu);			msblk->decompressor->free(stream->stream);		}		free_percpu(percpu);	}} int squashfs_decompress(struct squashfs_sb_info *msblk, struct buffer_head **bh,	int b, int offset, int length, struct squashfs_page_actor *output){	struct squashfs_stream __percpu *percpu =			(struct squashfs_stream __percpu *) msblk->stream;	struct squashfs_stream *stream = get_cpu_ptr(percpu);	int res = msblk->decompressor->decompress(msblk, stream->stream, bh, b,		offset, length, output);	put_cpu_ptr(stream); 	if (res < 0)		ERROR("%s decompression failed, data probably corrupt\n",			msblk->decompressor->name); 	return res;} int squashfs_max_decompressors(void){	return num_possible_cpus();}