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