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 } 96