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 #include <linux/kernel.h> 18 #include <linux/zlib.h> 19 #include <linux/zutil.h> 20 #include "nodelist.h" 21 #include "compr.h" 22 23 /* Plan: call deflate() with avail_in == *sourcelen, 24 avail_out = *dstlen - 12 and flush == Z_FINISH. 25 If it doesn't manage to finish, call it again with 26 avail_in == 0 and avail_out set to the remaining 12 27 bytes for it to clean up. 28 Q: Is 12 bytes sufficient? 29 */ 30 #define STREAM_END_SPACE 12 31 32 static DEFINE_MUTEX(deflate_mutex); 33 static DEFINE_MUTEX(inflate_mutex); 34 static z_stream inf_strm, def_strm; 35 36 #ifdef __KERNEL__ /* Linux-only */ 37 #include <linux/vmalloc.h> 38 #include <linux/init.h> 39 #include <linux/mutex.h> 40 41 static int __init alloc_workspaces(void) 42 { 43 def_strm.workspace = vmalloc(zlib_deflate_workspacesize(MAX_WBITS, 44 MAX_MEM_LEVEL)); 45 if (!def_strm.workspace) 46 return -ENOMEM; 47 48 D1(printk(KERN_DEBUG "Allocated %d bytes for deflate workspace\n", zlib_deflate_workspacesize(MAX_WBITS, MAX_MEM_LEVEL))); 49 inf_strm.workspace = vmalloc(zlib_inflate_workspacesize()); 50 if (!inf_strm.workspace) { 51 vfree(def_strm.workspace); 52 return -ENOMEM; 53 } 54 D1(printk(KERN_DEBUG "Allocated %d bytes for inflate workspace\n", zlib_inflate_workspacesize())); 55 return 0; 56 } 57 58 static void free_workspaces(void) 59 { 60 vfree(def_strm.workspace); 61 vfree(inf_strm.workspace); 62 } 63 #else 64 #define alloc_workspaces() (0) 65 #define free_workspaces() do { } while(0) 66 #endif /* __KERNEL__ */ 67 68 static int jffs2_zlib_compress(unsigned char *data_in, 69 unsigned char *cpage_out, 70 uint32_t *sourcelen, uint32_t *dstlen) 71 { 72 int ret; 73 74 if (*dstlen <= STREAM_END_SPACE) 75 return -1; 76 77 mutex_lock(&deflate_mutex); 78 79 if (Z_OK != zlib_deflateInit(&def_strm, 3)) { 80 printk(KERN_WARNING "deflateInit failed\n"); 81 mutex_unlock(&deflate_mutex); 82 return -1; 83 } 84 85 def_strm.next_in = data_in; 86 def_strm.total_in = 0; 87 88 def_strm.next_out = cpage_out; 89 def_strm.total_out = 0; 90 91 while (def_strm.total_out < *dstlen - STREAM_END_SPACE && def_strm.total_in < *sourcelen) { 92 def_strm.avail_out = *dstlen - (def_strm.total_out + STREAM_END_SPACE); 93 def_strm.avail_in = min((unsigned)(*sourcelen-def_strm.total_in), def_strm.avail_out); 94 D1(printk(KERN_DEBUG "calling deflate with avail_in %d, avail_out %d\n", 95 def_strm.avail_in, def_strm.avail_out)); 96 ret = zlib_deflate(&def_strm, Z_PARTIAL_FLUSH); 97 D1(printk(KERN_DEBUG "deflate returned with avail_in %d, avail_out %d, total_in %ld, total_out %ld\n", 98 def_strm.avail_in, def_strm.avail_out, def_strm.total_in, def_strm.total_out)); 99 if (ret != Z_OK) { 100 D1(printk(KERN_DEBUG "deflate in loop returned %d\n", ret)); 101 zlib_deflateEnd(&def_strm); 102 mutex_unlock(&deflate_mutex); 103 return -1; 104 } 105 } 106 def_strm.avail_out += STREAM_END_SPACE; 107 def_strm.avail_in = 0; 108 ret = zlib_deflate(&def_strm, Z_FINISH); 109 zlib_deflateEnd(&def_strm); 110 111 if (ret != Z_STREAM_END) { 112 D1(printk(KERN_DEBUG "final deflate returned %d\n", ret)); 113 ret = -1; 114 goto out; 115 } 116 117 if (def_strm.total_out >= def_strm.total_in) { 118 D1(printk(KERN_DEBUG "zlib compressed %ld bytes into %ld; failing\n", 119 def_strm.total_in, def_strm.total_out)); 120 ret = -1; 121 goto out; 122 } 123 124 D1(printk(KERN_DEBUG "zlib compressed %ld bytes into %ld\n", 125 def_strm.total_in, def_strm.total_out)); 126 127 *dstlen = def_strm.total_out; 128 *sourcelen = def_strm.total_in; 129 ret = 0; 130 out: 131 mutex_unlock(&deflate_mutex); 132 return ret; 133 } 134 135 static int jffs2_zlib_decompress(unsigned char *data_in, 136 unsigned char *cpage_out, 137 uint32_t srclen, uint32_t destlen) 138 { 139 int ret; 140 int wbits = MAX_WBITS; 141 142 mutex_lock(&inflate_mutex); 143 144 inf_strm.next_in = data_in; 145 inf_strm.avail_in = srclen; 146 inf_strm.total_in = 0; 147 148 inf_strm.next_out = cpage_out; 149 inf_strm.avail_out = destlen; 150 inf_strm.total_out = 0; 151 152 /* If it's deflate, and it's got no preset dictionary, then 153 we can tell zlib to skip the adler32 check. */ 154 if (srclen > 2 && !(data_in[1] & PRESET_DICT) && 155 ((data_in[0] & 0x0f) == Z_DEFLATED) && 156 !(((data_in[0]<<8) + data_in[1]) % 31)) { 157 158 D2(printk(KERN_DEBUG "inflate skipping adler32\n")); 159 wbits = -((data_in[0] >> 4) + 8); 160 inf_strm.next_in += 2; 161 inf_strm.avail_in -= 2; 162 } else { 163 /* Let this remain D1 for now -- it should never happen */ 164 D1(printk(KERN_DEBUG "inflate not skipping adler32\n")); 165 } 166 167 168 if (Z_OK != zlib_inflateInit2(&inf_strm, wbits)) { 169 printk(KERN_WARNING "inflateInit failed\n"); 170 mutex_unlock(&inflate_mutex); 171 return 1; 172 } 173 174 while((ret = zlib_inflate(&inf_strm, Z_FINISH)) == Z_OK) 175 ; 176 if (ret != Z_STREAM_END) { 177 printk(KERN_NOTICE "inflate returned %d\n", ret); 178 } 179 zlib_inflateEnd(&inf_strm); 180 mutex_unlock(&inflate_mutex); 181 return 0; 182 } 183 184 static struct jffs2_compressor jffs2_zlib_comp = { 185 .priority = JFFS2_ZLIB_PRIORITY, 186 .name = "zlib", 187 .compr = JFFS2_COMPR_ZLIB, 188 .compress = &jffs2_zlib_compress, 189 .decompress = &jffs2_zlib_decompress, 190 #ifdef JFFS2_ZLIB_DISABLED 191 .disabled = 1, 192 #else 193 .disabled = 0, 194 #endif 195 }; 196 197 int __init jffs2_zlib_init(void) 198 { 199 int ret; 200 201 ret = alloc_workspaces(); 202 if (ret) 203 return ret; 204 205 ret = jffs2_register_compressor(&jffs2_zlib_comp); 206 if (ret) 207 free_workspaces(); 208 209 return ret; 210 } 211 212 void jffs2_zlib_exit(void) 213 { 214 jffs2_unregister_compressor(&jffs2_zlib_comp); 215 free_workspaces(); 216 } 217