1 /* 2 * JFFS2 -- Journalling Flash File System, Version 2. 3 * 4 * Copyright (C) 2001-2003 Red Hat, Inc. 5 * 6 * Created by David Woodhouse <dwmw2@infradead.org> 7 * 8 * For licensing information, see the file 'LICENCE' in this directory. 9 * 10 * $Id: compr_zlib.c,v 1.32 2005/11/07 11:14:38 gleixner Exp $ 11 * 12 */ 13 14 #if !defined(__KERNEL__) && !defined(__ECOS) 15 #error "The userspace support got too messy and was removed. Update your mkfs.jffs2" 16 #endif 17 18 #include <linux/config.h> 19 #include <linux/kernel.h> 20 #include <linux/sched.h> 21 #include <linux/slab.h> 22 #include <linux/zlib.h> 23 #include <linux/zutil.h> 24 #include "nodelist.h" 25 #include "compr.h" 26 27 /* Plan: call deflate() with avail_in == *sourcelen, 28 avail_out = *dstlen - 12 and flush == Z_FINISH. 29 If it doesn't manage to finish, call it again with 30 avail_in == 0 and avail_out set to the remaining 12 31 bytes for it to clean up. 32 Q: Is 12 bytes sufficient? 33 */ 34 #define STREAM_END_SPACE 12 35 36 static DEFINE_MUTEX(deflate_mutex); 37 static DEFINE_MUTEX(inflate_mutex); 38 static z_stream inf_strm, def_strm; 39 40 #ifdef __KERNEL__ /* Linux-only */ 41 #include <linux/vmalloc.h> 42 #include <linux/init.h> 43 #include <linux/mutex.h> 44 45 static int __init alloc_workspaces(void) 46 { 47 def_strm.workspace = vmalloc(zlib_deflate_workspacesize()); 48 if (!def_strm.workspace) { 49 printk(KERN_WARNING "Failed to allocate %d bytes for deflate workspace\n", zlib_deflate_workspacesize()); 50 return -ENOMEM; 51 } 52 D1(printk(KERN_DEBUG "Allocated %d bytes for deflate workspace\n", zlib_deflate_workspacesize())); 53 inf_strm.workspace = vmalloc(zlib_inflate_workspacesize()); 54 if (!inf_strm.workspace) { 55 printk(KERN_WARNING "Failed to allocate %d bytes for inflate workspace\n", zlib_inflate_workspacesize()); 56 vfree(def_strm.workspace); 57 return -ENOMEM; 58 } 59 D1(printk(KERN_DEBUG "Allocated %d bytes for inflate workspace\n", zlib_inflate_workspacesize())); 60 return 0; 61 } 62 63 static void __exit free_workspaces(void) 64 { 65 vfree(def_strm.workspace); 66 vfree(inf_strm.workspace); 67 } 68 #else 69 #define alloc_workspaces() (0) 70 #define free_workspaces() do { } while(0) 71 #endif /* __KERNEL__ */ 72 73 static int jffs2_zlib_compress(unsigned char *data_in, 74 unsigned char *cpage_out, 75 uint32_t *sourcelen, uint32_t *dstlen, 76 void *model) 77 { 78 int ret; 79 80 if (*dstlen <= STREAM_END_SPACE) 81 return -1; 82 83 mutex_lock(&deflate_mutex); 84 85 if (Z_OK != zlib_deflateInit(&def_strm, 3)) { 86 printk(KERN_WARNING "deflateInit failed\n"); 87 mutex_unlock(&deflate_mutex); 88 return -1; 89 } 90 91 def_strm.next_in = data_in; 92 def_strm.total_in = 0; 93 94 def_strm.next_out = cpage_out; 95 def_strm.total_out = 0; 96 97 while (def_strm.total_out < *dstlen - STREAM_END_SPACE && def_strm.total_in < *sourcelen) { 98 def_strm.avail_out = *dstlen - (def_strm.total_out + STREAM_END_SPACE); 99 def_strm.avail_in = min((unsigned)(*sourcelen-def_strm.total_in), def_strm.avail_out); 100 D1(printk(KERN_DEBUG "calling deflate with avail_in %d, avail_out %d\n", 101 def_strm.avail_in, def_strm.avail_out)); 102 ret = zlib_deflate(&def_strm, Z_PARTIAL_FLUSH); 103 D1(printk(KERN_DEBUG "deflate returned with avail_in %d, avail_out %d, total_in %ld, total_out %ld\n", 104 def_strm.avail_in, def_strm.avail_out, def_strm.total_in, def_strm.total_out)); 105 if (ret != Z_OK) { 106 D1(printk(KERN_DEBUG "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 D1(printk(KERN_DEBUG "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 D1(printk(KERN_DEBUG "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 D1(printk(KERN_DEBUG "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 } 140 141 static int jffs2_zlib_decompress(unsigned char *data_in, 142 unsigned char *cpage_out, 143 uint32_t srclen, uint32_t destlen, 144 void *model) 145 { 146 int ret; 147 int wbits = MAX_WBITS; 148 149 mutex_lock(&inflate_mutex); 150 151 inf_strm.next_in = data_in; 152 inf_strm.avail_in = srclen; 153 inf_strm.total_in = 0; 154 155 inf_strm.next_out = cpage_out; 156 inf_strm.avail_out = destlen; 157 inf_strm.total_out = 0; 158 159 /* If it's deflate, and it's got no preset dictionary, then 160 we can tell zlib to skip the adler32 check. */ 161 if (srclen > 2 && !(data_in[1] & PRESET_DICT) && 162 ((data_in[0] & 0x0f) == Z_DEFLATED) && 163 !(((data_in[0]<<8) + data_in[1]) % 31)) { 164 165 D2(printk(KERN_DEBUG "inflate skipping adler32\n")); 166 wbits = -((data_in[0] >> 4) + 8); 167 inf_strm.next_in += 2; 168 inf_strm.avail_in -= 2; 169 } else { 170 /* Let this remain D1 for now -- it should never happen */ 171 D1(printk(KERN_DEBUG "inflate not skipping adler32\n")); 172 } 173 174 175 if (Z_OK != zlib_inflateInit2(&inf_strm, wbits)) { 176 printk(KERN_WARNING "inflateInit failed\n"); 177 mutex_unlock(&inflate_mutex); 178 return 1; 179 } 180 181 while((ret = zlib_inflate(&inf_strm, Z_FINISH)) == Z_OK) 182 ; 183 if (ret != Z_STREAM_END) { 184 printk(KERN_NOTICE "inflate returned %d\n", ret); 185 } 186 zlib_inflateEnd(&inf_strm); 187 mutex_unlock(&inflate_mutex); 188 return 0; 189 } 190 191 static struct jffs2_compressor jffs2_zlib_comp = { 192 .priority = JFFS2_ZLIB_PRIORITY, 193 .name = "zlib", 194 .compr = JFFS2_COMPR_ZLIB, 195 .compress = &jffs2_zlib_compress, 196 .decompress = &jffs2_zlib_decompress, 197 #ifdef JFFS2_ZLIB_DISABLED 198 .disabled = 1, 199 #else 200 .disabled = 0, 201 #endif 202 }; 203 204 int __init jffs2_zlib_init(void) 205 { 206 int ret; 207 208 ret = alloc_workspaces(); 209 if (ret) 210 return ret; 211 212 ret = jffs2_register_compressor(&jffs2_zlib_comp); 213 if (ret) 214 free_workspaces(); 215 216 return ret; 217 } 218 219 void __exit jffs2_zlib_exit(void) 220 { 221 jffs2_unregister_compressor(&jffs2_zlib_comp); 222 free_workspaces(); 223 } 224