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20c8ccb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
d208383d PL |
2 | /* |
3 | * Copyright (c) 2013 | |
4 | * Phillip Lougher <phillip@squashfs.org.uk> | |
d208383d PL |
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 | ||
22 | struct squashfs_stream { | |
23 | void *stream; | |
24 | }; | |
25 | ||
26 | void *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 | ||
49 | out: | |
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 | ||
59 | void 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 | ||
846b730e PL |
75 | int squashfs_decompress(struct squashfs_sb_info *msblk, struct buffer_head **bh, |
76 | int b, int offset, int length, struct squashfs_page_actor *output) | |
d208383d PL |
77 | { |
78 | struct squashfs_stream __percpu *percpu = | |
79 | (struct squashfs_stream __percpu *) msblk->stream; | |
80 | struct squashfs_stream *stream = get_cpu_ptr(percpu); | |
846b730e PL |
81 | int res = msblk->decompressor->decompress(msblk, stream->stream, bh, b, |
82 | offset, length, output); | |
d208383d PL |
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 | ||
92 | int squashfs_max_decompressors(void) | |
93 | { | |
94 | return num_possible_cpus(); | |
95 | } |