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	Squashfs has stopped using buffers heads in 93e72b3c61
("squashfs: migrate from ll_rw_block usage to BIO").
Link: https://lkml.kernel.org/r/20230517071622.245151-1-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Pankaj Raghav <p.raghav@samsung.com>
Reviewed-by: Phillip Lougher <phillip@squashfs.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
		
	
			
		
			
				
	
	
		
			110 lines
		
	
	
	
		
			2.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			110 lines
		
	
	
	
		
			2.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
// SPDX-License-Identifier: GPL-2.0-only
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/*
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 * Copyright (c) 2013
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 * Phillip Lougher <phillip@squashfs.org.uk>
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 */
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#include <linux/types.h>
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#include <linux/slab.h>
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#include <linux/percpu.h>
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#include <linux/local_lock.h>
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#include "squashfs_fs.h"
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#include "squashfs_fs_sb.h"
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#include "decompressor.h"
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#include "squashfs.h"
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/*
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 * This file implements multi-threaded decompression using percpu
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 * variables, one thread per cpu core.
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 */
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struct squashfs_stream {
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	void			*stream;
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	local_lock_t	lock;
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};
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static void *squashfs_decompressor_create(struct squashfs_sb_info *msblk,
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						void *comp_opts)
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{
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	struct squashfs_stream *stream;
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	struct squashfs_stream __percpu *percpu;
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	int err, cpu;
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	percpu = alloc_percpu(struct squashfs_stream);
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	if (percpu == NULL)
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		return ERR_PTR(-ENOMEM);
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	for_each_possible_cpu(cpu) {
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		stream = per_cpu_ptr(percpu, cpu);
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		stream->stream = msblk->decompressor->init(msblk, comp_opts);
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		if (IS_ERR(stream->stream)) {
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			err = PTR_ERR(stream->stream);
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			goto out;
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		}
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		local_lock_init(&stream->lock);
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	}
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	kfree(comp_opts);
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	return (__force void *) percpu;
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out:
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	for_each_possible_cpu(cpu) {
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		stream = per_cpu_ptr(percpu, cpu);
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		if (!IS_ERR_OR_NULL(stream->stream))
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			msblk->decompressor->free(stream->stream);
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	}
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	free_percpu(percpu);
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	return ERR_PTR(err);
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}
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static void squashfs_decompressor_destroy(struct squashfs_sb_info *msblk)
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{
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	struct squashfs_stream __percpu *percpu =
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			(struct squashfs_stream __percpu *) msblk->stream;
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	struct squashfs_stream *stream;
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	int cpu;
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	if (msblk->stream) {
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		for_each_possible_cpu(cpu) {
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			stream = per_cpu_ptr(percpu, cpu);
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			msblk->decompressor->free(stream->stream);
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		}
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		free_percpu(percpu);
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	}
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}
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static int squashfs_decompress(struct squashfs_sb_info *msblk, struct bio *bio,
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	int offset, int length, struct squashfs_page_actor *output)
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{
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	struct squashfs_stream *stream;
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	struct squashfs_stream __percpu *percpu =
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			(struct squashfs_stream __percpu *) msblk->stream;
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	int res;
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	local_lock(&percpu->lock);
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	stream = this_cpu_ptr(percpu);
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	res = msblk->decompressor->decompress(msblk, stream->stream, bio,
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					      offset, length, output);
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	local_unlock(&percpu->lock);
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	if (res < 0)
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		ERROR("%s decompression failed, data probably corrupt\n",
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			msblk->decompressor->name);
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	return res;
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}
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static int squashfs_max_decompressors(void)
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{
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	return num_possible_cpus();
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}
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const struct squashfs_decompressor_thread_ops squashfs_decompressor_percpu = {
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	.create = squashfs_decompressor_create,
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	.destroy = squashfs_decompressor_destroy,
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	.decompress = squashfs_decompress,
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	.max_decompressors = squashfs_max_decompressors,
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};
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