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 printk(KERN_WARNING "Failed to allocate %d bytes for deflate workspace\n", zlib_deflate_workspacesize(MAX_WBITS, MAX_MEM_LEVEL)); 47 return -ENOMEM; 48 } 49 D1(printk(KERN_DEBUG "Allocated %d bytes for deflate workspace\n", zlib_deflate_workspacesize(MAX_WBITS, MAX_MEM_LEVEL))); 50 inf_strm.workspace = vmalloc(zlib_inflate_workspacesize()); 51 if (!inf_strm.workspace) { 52 printk(KERN_WARNING "Failed to allocate %d bytes for inflate workspace\n", zlib_inflate_workspacesize()); 53 vfree(def_strm.workspace); 54 return -ENOMEM; 55 } 56 D1(printk(KERN_DEBUG "Allocated %d bytes for inflate workspace\n", zlib_inflate_workspacesize())); 57 return 0; 58 } 59 60 static void free_workspaces(void) 61 { 62 vfree(def_strm.workspace); 63 vfree(inf_strm.workspace); 64 } 65 #else 66 #define alloc_workspaces() (0) 67 #define free_workspaces() do { } while(0) 68 #endif /* __KERNEL__ */ 69 70 static int jffs2_zlib_compress(unsigned char *data_in, 71 unsigned char *cpage_out, 72 uint32_t *sourcelen, uint32_t *dstlen) 73 { 74 int ret; 75 76 if (*dstlen <= STREAM_END_SPACE) 77 return -1; 78 79 mutex_lock(&deflate_mutex); 80 81 if (Z_OK != zlib_deflateInit(&def_strm, 3)) { 82 printk(KERN_WARNING "deflateInit failed\n"); 83 mutex_unlock(&deflate_mutex); 84 return -1; 85 } 86 87 def_strm.next_in = data_in; 88 def_strm.total_in = 0; 89 90 def_strm.next_out = cpage_out; 91 def_strm.total_out = 0; 92 93 while (def_strm.total_out < *dstlen - STREAM_END_SPACE && def_strm.total_in < *sourcelen) { 94 def_strm.avail_out = *dstlen - (def_strm.total_out + STREAM_END_SPACE); 95 def_strm.avail_in = min((unsigned)(*sourcelen-def_strm.total_in), def_strm.avail_out); 96 D1(printk(KERN_DEBUG "calling deflate with avail_in %d, avail_out %d\n", 97 def_strm.avail_in, def_strm.avail_out)); 98 ret = zlib_deflate(&def_strm, Z_PARTIAL_FLUSH); 99 D1(printk(KERN_DEBUG "deflate returned with avail_in %d, avail_out %d, total_in %ld, total_out %ld\n", 100 def_strm.avail_in, def_strm.avail_out, def_strm.total_in, def_strm.total_out)); 101 if (ret != Z_OK) { 102 D1(printk(KERN_DEBUG "deflate in loop returned %d\n", ret)); 103 zlib_deflateEnd(&def_strm); 104 mutex_unlock(&deflate_mutex); 105 return -1; 106 } 107 } 108 def_strm.avail_out += STREAM_END_SPACE; 109 def_strm.avail_in = 0; 110 ret = zlib_deflate(&def_strm, Z_FINISH); 111 zlib_deflateEnd(&def_strm); 112 113 if (ret != Z_STREAM_END) { 114 D1(printk(KERN_DEBUG "final deflate returned %d\n", ret)); 115 ret = -1; 116 goto out; 117 } 118 119 if (def_strm.total_out >= def_strm.total_in) { 120 D1(printk(KERN_DEBUG "zlib compressed %ld bytes into %ld; failing\n", 121 def_strm.total_in, def_strm.total_out)); 122 ret = -1; 123 goto out; 124 } 125 126 D1(printk(KERN_DEBUG "zlib compressed %ld bytes into %ld\n", 127 def_strm.total_in, def_strm.total_out)); 128 129 *dstlen = def_strm.total_out; 130 *sourcelen = def_strm.total_in; 131 ret = 0; 132 out: 133 mutex_unlock(&deflate_mutex); 134 return ret; 135 } 136 137 static int jffs2_zlib_decompress(unsigned char *data_in, 138 unsigned char *cpage_out, 139 uint32_t srclen, uint32_t destlen) 140 { 141 int ret; 142 int wbits = MAX_WBITS; 143 144 mutex_lock(&inflate_mutex); 145 146 inf_strm.next_in = data_in; 147 inf_strm.avail_in = srclen; 148 inf_strm.total_in = 0; 149 150 inf_strm.next_out = cpage_out; 151 inf_strm.avail_out = destlen; 152 inf_strm.total_out = 0; 153 154 /* If it's deflate, and it's got no preset dictionary, then 155 we can tell zlib to skip the adler32 check. */ 156 if (srclen > 2 && !(data_in[1] & PRESET_DICT) && 157 ((data_in[0] & 0x0f) == Z_DEFLATED) && 158 !(((data_in[0]<<8) + data_in[1]) % 31)) { 159 160 D2(printk(KERN_DEBUG "inflate skipping adler32\n")); 161 wbits = -((data_in[0] >> 4) + 8); 162 inf_strm.next_in += 2; 163 inf_strm.avail_in -= 2; 164 } else { 165 /* Let this remain D1 for now -- it should never happen */ 166 D1(printk(KERN_DEBUG "inflate not skipping adler32\n")); 167 } 168 169 170 if (Z_OK != zlib_inflateInit2(&inf_strm, wbits)) { 171 printk(KERN_WARNING "inflateInit failed\n"); 172 mutex_unlock(&inflate_mutex); 173 return 1; 174 } 175 176 while((ret = zlib_inflate(&inf_strm, Z_FINISH)) == Z_OK) 177 ; 178 if (ret != Z_STREAM_END) { 179 printk(KERN_NOTICE "inflate returned %d\n", ret); 180 } 181 zlib_inflateEnd(&inf_strm); 182 mutex_unlock(&inflate_mutex); 183 return 0; 184 } 185 186 static struct jffs2_compressor jffs2_zlib_comp = { 187 .priority = JFFS2_ZLIB_PRIORITY, 188 .name = "zlib", 189 .compr = JFFS2_COMPR_ZLIB, 190 .compress = &jffs2_zlib_compress, 191 .decompress = &jffs2_zlib_decompress, 192 #ifdef JFFS2_ZLIB_DISABLED 193 .disabled = 1, 194 #else 195 .disabled = 0, 196 #endif 197 }; 198 199 int __init jffs2_zlib_init(void) 200 { 201 int ret; 202 203 ret = alloc_workspaces(); 204 if (ret) 205 return ret; 206 207 ret = jffs2_register_compressor(&jffs2_zlib_comp); 208 if (ret) 209 free_workspaces(); 210 211 return ret; 212 } 213 214 void jffs2_zlib_exit(void) 215 { 216 jffs2_unregister_compressor(&jffs2_zlib_comp); 217 free_workspaces(); 218 } 219