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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 | // SPDX-License-Identifier: GPL-2.0-or-later /* * Squashfs - a compressed read only filesystem for Linux * * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 * Phillip Lougher <phillip@squashfs.org.uk> * * decompressor.c */ #include <linux/types.h> #include <linux/mutex.h> #include <linux/slab.h> #include "squashfs_fs.h" #include "squashfs_fs_sb.h" #include "decompressor.h" #include "squashfs.h" #include "page_actor.h" /* * This file (and decompressor.h) implements a decompressor framework for * Squashfs, allowing multiple decompressors to be easily supported */ static const struct squashfs_decompressor squashfs_lzma_unsupported_comp_ops = { NULL, NULL, NULL, NULL, LZMA_COMPRESSION, "lzma", 0 }; #ifndef CONFIG_SQUASHFS_LZ4 static const struct squashfs_decompressor squashfs_lz4_comp_ops = { NULL, NULL, NULL, NULL, LZ4_COMPRESSION, "lz4", 0 }; #endif #ifndef CONFIG_SQUASHFS_LZO static const struct squashfs_decompressor squashfs_lzo_comp_ops = { NULL, NULL, NULL, NULL, LZO_COMPRESSION, "lzo", 0 }; #endif #ifndef CONFIG_SQUASHFS_XZ static const struct squashfs_decompressor squashfs_xz_comp_ops = { NULL, NULL, NULL, NULL, XZ_COMPRESSION, "xz", 0 }; #endif #ifndef CONFIG_SQUASHFS_ZLIB static const struct squashfs_decompressor squashfs_zlib_comp_ops = { NULL, NULL, NULL, NULL, ZLIB_COMPRESSION, "zlib", 0 }; #endif #ifndef CONFIG_SQUASHFS_ZSTD static const struct squashfs_decompressor squashfs_zstd_comp_ops = { NULL, NULL, NULL, NULL, ZSTD_COMPRESSION, "zstd", 0 }; #endif static const struct squashfs_decompressor squashfs_unknown_comp_ops = { NULL, NULL, NULL, NULL, 0, "unknown", 0 }; static const struct squashfs_decompressor *decompressor[] = { &squashfs_zlib_comp_ops, &squashfs_lz4_comp_ops, &squashfs_lzo_comp_ops, &squashfs_xz_comp_ops, &squashfs_lzma_unsupported_comp_ops, &squashfs_zstd_comp_ops, &squashfs_unknown_comp_ops }; const struct squashfs_decompressor *squashfs_lookup_decompressor(int id) { int i; for (i = 0; decompressor[i]->id; i++) if (id == decompressor[i]->id) break; return decompressor[i]; } static void *get_comp_opts(struct super_block *sb, unsigned short flags) { struct squashfs_sb_info *msblk = sb->s_fs_info; void *buffer = NULL, *comp_opts; struct squashfs_page_actor *actor = NULL; int length = 0; /* * Read decompressor specific options from file system if present */ if (SQUASHFS_COMP_OPTS(flags)) { buffer = kmalloc(PAGE_SIZE, GFP_KERNEL); if (buffer == NULL) { comp_opts = ERR_PTR(-ENOMEM); goto out; } actor = squashfs_page_actor_init(&buffer, 1, 0); if (actor == NULL) { comp_opts = ERR_PTR(-ENOMEM); goto out; } length = squashfs_read_data(sb, sizeof(struct squashfs_super_block), 0, NULL, actor); if (length < 0) { comp_opts = ERR_PTR(length); goto out; } } comp_opts = squashfs_comp_opts(msblk, buffer, length); out: kfree(actor); kfree(buffer); return comp_opts; } void *squashfs_decompressor_setup(struct super_block *sb, unsigned short flags) { struct squashfs_sb_info *msblk = sb->s_fs_info; void *stream, *comp_opts = get_comp_opts(sb, flags); if (IS_ERR(comp_opts)) return comp_opts; stream = msblk->thread_ops->create(msblk, comp_opts); if (IS_ERR(stream)) kfree(comp_opts); return stream; } |