1/* 2 * JFFS2 -- Journalling Flash File System, Version 2. 3 * 4 * Copyright �� 2001-2007 Red Hat, Inc. 5 * Copyright �� 2004-2010 David Woodhouse <dwmw2@infradead.org> 6 * 7 * Created by David Woodhouse <dwmw2@infradead.org> 8 * 9 * For licensing information, see the file 'LICENCE' in this directory. 10 * 11 */ 12 13#if !defined(__KERNEL__) && !defined(__ECOS) 14#error "The userspace support got too messy and was removed. Update your mkfs.jffs2" 15#endif 16 17#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 18 19#include <linux/kernel.h> 20#include <linux/zlib.h> 21#include <linux/zutil.h> 22#include "nodelist.h" 23#include "compr.h" 24 25 /* Plan: call deflate() with avail_in == *sourcelen, 26 avail_out = *dstlen - 12 and flush == Z_FINISH. 27 If it doesn't manage to finish, call it again with 28 avail_in == 0 and avail_out set to the remaining 12 29 bytes for it to clean up. 30 Q: Is 12 bytes sufficient? 31 */ 32#define STREAM_END_SPACE 12 33 34static DEFINE_MUTEX(deflate_mutex); 35static DEFINE_MUTEX(inflate_mutex); 36static z_stream inf_strm, def_strm; 37 38#ifdef __KERNEL__ /* Linux-only */ 39#include <linux/vmalloc.h> 40#include <linux/init.h> 41#include <linux/mutex.h> 42 43static int __init alloc_workspaces(void) 44{ 45 def_strm.workspace = vmalloc(zlib_deflate_workspacesize(MAX_WBITS, 46 MAX_MEM_LEVEL)); 47 if (!def_strm.workspace) 48 return -ENOMEM; 49 50 jffs2_dbg(1, "Allocated %d bytes for deflate workspace\n", 51 zlib_deflate_workspacesize(MAX_WBITS, MAX_MEM_LEVEL)); 52 inf_strm.workspace = vmalloc(zlib_inflate_workspacesize()); 53 if (!inf_strm.workspace) { 54 vfree(def_strm.workspace); 55 return -ENOMEM; 56 } 57 jffs2_dbg(1, "Allocated %d bytes for inflate workspace\n", 58 zlib_inflate_workspacesize()); 59 return 0; 60} 61 62static void free_workspaces(void) 63{ 64 vfree(def_strm.workspace); 65 vfree(inf_strm.workspace); 66} 67#else 68#define alloc_workspaces() (0) 69#define free_workspaces() do { } while(0) 70#endif /* __KERNEL__ */ 71 72static int jffs2_zlib_compress(unsigned char *data_in, 73 unsigned char *cpage_out, 74 uint32_t *sourcelen, uint32_t *dstlen) 75{ 76 int ret; 77 78 if (*dstlen <= STREAM_END_SPACE) 79 return -1; 80 81 mutex_lock(&deflate_mutex); 82 83 if (Z_OK != zlib_deflateInit(&def_strm, 3)) { 84 pr_warn("deflateInit failed\n"); 85 mutex_unlock(&deflate_mutex); 86 return -1; 87 } 88 89 def_strm.next_in = data_in; 90 def_strm.total_in = 0; 91 92 def_strm.next_out = cpage_out; 93 def_strm.total_out = 0; 94 95 while (def_strm.total_out < *dstlen - STREAM_END_SPACE && def_strm.total_in < *sourcelen) { 96 def_strm.avail_out = *dstlen - (def_strm.total_out + STREAM_END_SPACE); 97 def_strm.avail_in = min_t(unsigned long, 98 (*sourcelen-def_strm.total_in), def_strm.avail_out); 99 jffs2_dbg(1, "calling deflate with avail_in %ld, avail_out %ld\n", 100 def_strm.avail_in, def_strm.avail_out); 101 ret = zlib_deflate(&def_strm, Z_PARTIAL_FLUSH); 102 jffs2_dbg(1, "deflate returned with avail_in %ld, avail_out %ld, total_in %ld, total_out %ld\n", 103 def_strm.avail_in, def_strm.avail_out, 104 def_strm.total_in, def_strm.total_out); 105 if (ret != Z_OK) { 106 jffs2_dbg(1, "deflate in loop returned %d\n", ret); 107 zlib_deflateEnd(&def_strm); 108 mutex_unlock(&deflate_mutex); 109 return -1; 110 } 111 } 112 def_strm.avail_out += STREAM_END_SPACE; 113 def_strm.avail_in = 0; 114 ret = zlib_deflate(&def_strm, Z_FINISH); 115 zlib_deflateEnd(&def_strm); 116 117 if (ret != Z_STREAM_END) { 118 jffs2_dbg(1, "final deflate returned %d\n", ret); 119 ret = -1; 120 goto out; 121 } 122 123 if (def_strm.total_out >= def_strm.total_in) { 124 jffs2_dbg(1, "zlib compressed %ld bytes into %ld; failing\n", 125 def_strm.total_in, def_strm.total_out); 126 ret = -1; 127 goto out; 128 } 129 130 jffs2_dbg(1, "zlib compressed %ld bytes into %ld\n", 131 def_strm.total_in, def_strm.total_out); 132 133 *dstlen = def_strm.total_out; 134 *sourcelen = def_strm.total_in; 135 ret = 0; 136 out: 137 mutex_unlock(&deflate_mutex); 138 return ret; 139} 140 141static int jffs2_zlib_decompress(unsigned char *data_in, 142 unsigned char *cpage_out, 143 uint32_t srclen, uint32_t destlen) 144{ 145 int ret; 146 int wbits = MAX_WBITS; 147 148 mutex_lock(&inflate_mutex); 149 150 inf_strm.next_in = data_in; 151 inf_strm.avail_in = srclen; 152 inf_strm.total_in = 0; 153 154 inf_strm.next_out = cpage_out; 155 inf_strm.avail_out = destlen; 156 inf_strm.total_out = 0; 157 158 /* If it's deflate, and it's got no preset dictionary, then 159 we can tell zlib to skip the adler32 check. */ 160 if (srclen > 2 && !(data_in[1] & PRESET_DICT) && 161 ((data_in[0] & 0x0f) == Z_DEFLATED) && 162 !(((data_in[0]<<8) + data_in[1]) % 31)) { 163 164 jffs2_dbg(2, "inflate skipping adler32\n"); 165 wbits = -((data_in[0] >> 4) + 8); 166 inf_strm.next_in += 2; 167 inf_strm.avail_in -= 2; 168 } else { 169 /* Let this remain D1 for now -- it should never happen */ 170 jffs2_dbg(1, "inflate not skipping adler32\n"); 171 } 172 173 174 if (Z_OK != zlib_inflateInit2(&inf_strm, wbits)) { 175 pr_warn("inflateInit failed\n"); 176 mutex_unlock(&inflate_mutex); 177 return 1; 178 } 179 180 while((ret = zlib_inflate(&inf_strm, Z_FINISH)) == Z_OK) 181 ; 182 if (ret != Z_STREAM_END) { 183 pr_notice("inflate returned %d\n", ret); 184 } 185 zlib_inflateEnd(&inf_strm); 186 mutex_unlock(&inflate_mutex); 187 return 0; 188} 189 190static struct jffs2_compressor jffs2_zlib_comp = { 191 .priority = JFFS2_ZLIB_PRIORITY, 192 .name = "zlib", 193 .compr = JFFS2_COMPR_ZLIB, 194 .compress = &jffs2_zlib_compress, 195 .decompress = &jffs2_zlib_decompress, 196#ifdef JFFS2_ZLIB_DISABLED 197 .disabled = 1, 198#else 199 .disabled = 0, 200#endif 201}; 202 203int __init jffs2_zlib_init(void) 204{ 205 int ret; 206 207 ret = alloc_workspaces(); 208 if (ret) 209 return ret; 210 211 ret = jffs2_register_compressor(&jffs2_zlib_comp); 212 if (ret) 213 free_workspaces(); 214 215 return ret; 216} 217 218void jffs2_zlib_exit(void) 219{ 220 jffs2_unregister_compressor(&jffs2_zlib_comp); 221 free_workspaces(); 222} 223