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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> | |
fd56200a | 11 | #include <linux/local_lock.h> |
d208383d PL |
12 | |
13 | #include "squashfs_fs.h" | |
14 | #include "squashfs_fs_sb.h" | |
15 | #include "decompressor.h" | |
16 | #include "squashfs.h" | |
17 | ||
18 | /* | |
19 | * This file implements multi-threaded decompression using percpu | |
20 | * variables, one thread per cpu core. | |
21 | */ | |
22 | ||
23 | struct squashfs_stream { | |
fd56200a JC |
24 | void *stream; |
25 | local_lock_t lock; | |
d208383d PL |
26 | }; |
27 | ||
80f78409 | 28 | static void *squashfs_decompressor_create(struct squashfs_sb_info *msblk, |
d208383d PL |
29 | void *comp_opts) |
30 | { | |
31 | struct squashfs_stream *stream; | |
32 | struct squashfs_stream __percpu *percpu; | |
33 | int err, cpu; | |
34 | ||
35 | percpu = alloc_percpu(struct squashfs_stream); | |
36 | if (percpu == NULL) | |
37 | return ERR_PTR(-ENOMEM); | |
38 | ||
39 | for_each_possible_cpu(cpu) { | |
40 | stream = per_cpu_ptr(percpu, cpu); | |
41 | stream->stream = msblk->decompressor->init(msblk, comp_opts); | |
42 | if (IS_ERR(stream->stream)) { | |
43 | err = PTR_ERR(stream->stream); | |
44 | goto out; | |
45 | } | |
fd56200a | 46 | local_lock_init(&stream->lock); |
d208383d PL |
47 | } |
48 | ||
49 | kfree(comp_opts); | |
50 | return (__force void *) percpu; | |
51 | ||
52 | out: | |
53 | for_each_possible_cpu(cpu) { | |
54 | stream = per_cpu_ptr(percpu, cpu); | |
55 | if (!IS_ERR_OR_NULL(stream->stream)) | |
56 | msblk->decompressor->free(stream->stream); | |
57 | } | |
58 | free_percpu(percpu); | |
59 | return ERR_PTR(err); | |
60 | } | |
61 | ||
80f78409 | 62 | static void squashfs_decompressor_destroy(struct squashfs_sb_info *msblk) |
d208383d PL |
63 | { |
64 | struct squashfs_stream __percpu *percpu = | |
65 | (struct squashfs_stream __percpu *) msblk->stream; | |
66 | struct squashfs_stream *stream; | |
67 | int cpu; | |
68 | ||
69 | if (msblk->stream) { | |
70 | for_each_possible_cpu(cpu) { | |
71 | stream = per_cpu_ptr(percpu, cpu); | |
72 | msblk->decompressor->free(stream->stream); | |
73 | } | |
74 | free_percpu(percpu); | |
75 | } | |
76 | } | |
77 | ||
80f78409 | 78 | static int squashfs_decompress(struct squashfs_sb_info *msblk, struct bio *bio, |
93e72b3c | 79 | int offset, int length, struct squashfs_page_actor *output) |
d208383d | 80 | { |
fd56200a | 81 | struct squashfs_stream *stream; |
80f78409 XN |
82 | struct squashfs_stream __percpu *percpu = |
83 | (struct squashfs_stream __percpu *) msblk->stream; | |
fd56200a JC |
84 | int res; |
85 | ||
80f78409 XN |
86 | local_lock(&percpu->lock); |
87 | stream = this_cpu_ptr(percpu); | |
fd56200a | 88 | |
93e72b3c PL |
89 | res = msblk->decompressor->decompress(msblk, stream->stream, bio, |
90 | offset, length, output); | |
fd56200a | 91 | |
80f78409 | 92 | local_unlock(&percpu->lock); |
d208383d PL |
93 | |
94 | if (res < 0) | |
95 | ERROR("%s decompression failed, data probably corrupt\n", | |
96 | msblk->decompressor->name); | |
97 | ||
98 | return res; | |
99 | } | |
100 | ||
80f78409 | 101 | static int squashfs_max_decompressors(void) |
d208383d PL |
102 | { |
103 | return num_possible_cpus(); | |
104 | } | |
80f78409 XN |
105 | |
106 | const struct squashfs_decompressor_thread_ops squashfs_decompressor_percpu = { | |
107 | .create = squashfs_decompressor_create, | |
108 | .destroy = squashfs_decompressor_destroy, | |
109 | .decompress = squashfs_decompress, | |
110 | .max_decompressors = squashfs_max_decompressors, | |
111 | }; |