Linux kernel mirror (for testing)
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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/slab.h>
9#include <linux/percpu.h>
10#include <linux/buffer_head.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 multi-threaded decompression using percpu
19 * variables, one thread per cpu core.
20 */
21
22struct squashfs_stream {
23 void *stream;
24};
25
26void *squashfs_decompressor_create(struct squashfs_sb_info *msblk,
27 void *comp_opts)
28{
29 struct squashfs_stream *stream;
30 struct squashfs_stream __percpu *percpu;
31 int err, cpu;
32
33 percpu = alloc_percpu(struct squashfs_stream);
34 if (percpu == NULL)
35 return ERR_PTR(-ENOMEM);
36
37 for_each_possible_cpu(cpu) {
38 stream = per_cpu_ptr(percpu, cpu);
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
46 kfree(comp_opts);
47 return (__force void *) percpu;
48
49out:
50 for_each_possible_cpu(cpu) {
51 stream = per_cpu_ptr(percpu, cpu);
52 if (!IS_ERR_OR_NULL(stream->stream))
53 msblk->decompressor->free(stream->stream);
54 }
55 free_percpu(percpu);
56 return ERR_PTR(err);
57}
58
59void squashfs_decompressor_destroy(struct squashfs_sb_info *msblk)
60{
61 struct squashfs_stream __percpu *percpu =
62 (struct squashfs_stream __percpu *) msblk->stream;
63 struct squashfs_stream *stream;
64 int cpu;
65
66 if (msblk->stream) {
67 for_each_possible_cpu(cpu) {
68 stream = per_cpu_ptr(percpu, cpu);
69 msblk->decompressor->free(stream->stream);
70 }
71 free_percpu(percpu);
72 }
73}
74
75int squashfs_decompress(struct squashfs_sb_info *msblk, struct buffer_head **bh,
76 int b, int offset, int length, struct squashfs_page_actor *output)
77{
78 struct squashfs_stream __percpu *percpu =
79 (struct squashfs_stream __percpu *) msblk->stream;
80 struct squashfs_stream *stream = get_cpu_ptr(percpu);
81 int res = msblk->decompressor->decompress(msblk, stream->stream, bh, b,
82 offset, length, output);
83 put_cpu_ptr(stream);
84
85 if (res < 0)
86 ERROR("%s decompression failed, data probably corrupt\n",
87 msblk->decompressor->name);
88
89 return res;
90}
91
92int squashfs_max_decompressors(void)
93{
94 return num_possible_cpus();
95}