1 /* 2 * JFFS2 -- Journalling Flash File System, Version 2. 3 * 4 * Copyright © 2001-2007 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 */ 11 12 #if !defined(__KERNEL__) && !defined(__ECOS) 13 #error "The userspace support got too messy and was removed. Update your mkfs.jffs2" 14 #endif 15 16 #include <linux/kernel.h> 17 #include <linux/slab.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()); 44 if (!def_strm.workspace) { 45 printk(KERN_WARNING "Failed to allocate %d bytes for deflate workspace\n", zlib_deflate_workspacesize()); 46 return -ENOMEM; 47 } 48 D1(printk(KERN_DEBUG "Allocated %d bytes for deflate workspace\n", zlib_deflate_workspacesize())); 49 inf_strm.workspace = vmalloc(zlib_inflate_workspacesize()); 50 if (!inf_strm.workspace) { 51 printk(KERN_WARNING "Failed to allocate %d bytes for inflate workspace\n", zlib_inflate_workspacesize()); 52 vfree(def_strm.workspace); 53 return -ENOMEM; 54 } 55 D1(printk(KERN_DEBUG "Allocated %d bytes for inflate workspace\n", zlib_inflate_workspacesize())); 56 return 0; 57 } 58 59 static void free_workspaces(void) 60 { 61 vfree(def_strm.workspace); 62 vfree(inf_strm.workspace); 63 } 64 #else 65 #define alloc_workspaces() (0) 66 #define free_workspaces() do { } while(0) 67 #endif /* __KERNEL__ */ 68 69 static int jffs2_zlib_compress(unsigned char *data_in, 70 unsigned char *cpage_out, 71 uint32_t *sourcelen, uint32_t *dstlen, 72 void *model) 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 void *model) 141 { 142 int ret; 143 int wbits = MAX_WBITS; 144 145 mutex_lock(&inflate_mutex); 146 147 inf_strm.next_in = data_in; 148 inf_strm.avail_in = srclen; 149 inf_strm.total_in = 0; 150 151 inf_strm.next_out = cpage_out; 152 inf_strm.avail_out = destlen; 153 inf_strm.total_out = 0; 154 155 /* If it's deflate, and it's got no preset dictionary, then 156 we can tell zlib to skip the adler32 check. */ 157 if (srclen > 2 && !(data_in[1] & PRESET_DICT) && 158 ((data_in[0] & 0x0f) == Z_DEFLATED) && 159 !(((data_in[0]<<8) + data_in[1]) % 31)) { 160 161 D2(printk(KERN_DEBUG "inflate skipping adler32\n")); 162 wbits = -((data_in[0] >> 4) + 8); 163 inf_strm.next_in += 2; 164 inf_strm.avail_in -= 2; 165 } else { 166 /* Let this remain D1 for now -- it should never happen */ 167 D1(printk(KERN_DEBUG "inflate not skipping adler32\n")); 168 } 169 170 171 if (Z_OK != zlib_inflateInit2(&inf_strm, wbits)) { 172 printk(KERN_WARNING "inflateInit failed\n"); 173 mutex_unlock(&inflate_mutex); 174 return 1; 175 } 176 177 while((ret = zlib_inflate(&inf_strm, Z_FINISH)) == Z_OK) 178 ; 179 if (ret != Z_STREAM_END) { 180 printk(KERN_NOTICE "inflate returned %d\n", ret); 181 } 182 zlib_inflateEnd(&inf_strm); 183 mutex_unlock(&inflate_mutex); 184 return 0; 185 } 186 187 static struct jffs2_compressor jffs2_zlib_comp = { 188 .priority = JFFS2_ZLIB_PRIORITY, 189 .name = "zlib", 190 .compr = JFFS2_COMPR_ZLIB, 191 .compress = &jffs2_zlib_compress, 192 .decompress = &jffs2_zlib_decompress, 193 #ifdef JFFS2_ZLIB_DISABLED 194 .disabled = 1, 195 #else 196 .disabled = 0, 197 #endif 198 }; 199 200 int __init jffs2_zlib_init(void) 201 { 202 int ret; 203 204 ret = alloc_workspaces(); 205 if (ret) 206 return ret; 207 208 ret = jffs2_register_compressor(&jffs2_zlib_comp); 209 if (ret) 210 free_workspaces(); 211 212 return ret; 213 } 214 215 void jffs2_zlib_exit(void) 216 { 217 jffs2_unregister_compressor(&jffs2_zlib_comp); 218 free_workspaces(); 219 } 220