| b.liu | e958203 | 2025-04-17 19:18:16 +0800 | [diff] [blame^] | 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 | |
| 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 | |
| 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) |
| 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 | |
| 92 | int squashfs_max_decompressors(void) |
| 93 | { |
| 94 | return num_possible_cpus(); |
| 95 | } |