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 1.29 2004/11/16 20:36:11 dwmw2 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/slab.h> 21 #include <linux/zlib.h> 22 #include <linux/zutil.h> 23 #include <asm/semaphore.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 DECLARE_MUTEX(deflate_sem); 37 static DECLARE_MUTEX(inflate_sem); 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 44 static int __init alloc_workspaces(void) 45 { 46 def_strm.workspace = vmalloc(zlib_deflate_workspacesize()); 47 if (!def_strm.workspace) { 48 printk(KERN_WARNING "Failed to allocate %d bytes for deflate workspace\n", zlib_deflate_workspacesize()); 49 return -ENOMEM; 50 } 51 D1(printk(KERN_DEBUG "Allocated %d bytes for deflate workspace\n", zlib_deflate_workspacesize())); 52 inf_strm.workspace = vmalloc(zlib_inflate_workspacesize()); 53 if (!inf_strm.workspace) { 54 printk(KERN_WARNING "Failed to allocate %d bytes for inflate workspace\n", zlib_inflate_workspacesize()); 55 vfree(def_strm.workspace); 56 return -ENOMEM; 57 } 58 D1(printk(KERN_DEBUG "Allocated %d bytes for inflate workspace\n", zlib_inflate_workspacesize())); 59 return 0; 60 } 61 62 static 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 72 int jffs2_zlib_compress(unsigned char *data_in, unsigned char *cpage_out, 73 uint32_t *sourcelen, uint32_t *dstlen, void *model) 74 { 75 int ret; 76 77 if (*dstlen <= STREAM_END_SPACE) 78 return -1; 79 80 down(&deflate_sem); 81 82 if (Z_OK != zlib_deflateInit(&def_strm, 3)) { 83 printk(KERN_WARNING "deflateInit failed\n"); 84 up(&deflate_sem); 85 return -1; 86 } 87 88 def_strm.next_in = data_in; 89 def_strm.total_in = 0; 90 91 def_strm.next_out = cpage_out; 92 def_strm.total_out = 0; 93 94 while (def_strm.total_out < *dstlen - STREAM_END_SPACE && def_strm.total_in < *sourcelen) { 95 def_strm.avail_out = *dstlen - (def_strm.total_out + STREAM_END_SPACE); 96 def_strm.avail_in = min((unsigned)(*sourcelen-def_strm.total_in), def_strm.avail_out); 97 D1(printk(KERN_DEBUG "calling deflate with avail_in %d, avail_out %d\n", 98 def_strm.avail_in, def_strm.avail_out)); 99 ret = zlib_deflate(&def_strm, Z_PARTIAL_FLUSH); 100 D1(printk(KERN_DEBUG "deflate returned with avail_in %d, avail_out %d, total_in %ld, total_out %ld\n", 101 def_strm.avail_in, def_strm.avail_out, def_strm.total_in, def_strm.total_out)); 102 if (ret != Z_OK) { 103 D1(printk(KERN_DEBUG "deflate in loop returned %d\n", ret)); 104 zlib_deflateEnd(&def_strm); 105 up(&deflate_sem); 106 return -1; 107 } 108 } 109 def_strm.avail_out += STREAM_END_SPACE; 110 def_strm.avail_in = 0; 111 ret = zlib_deflate(&def_strm, Z_FINISH); 112 zlib_deflateEnd(&def_strm); 113 114 if (ret != Z_STREAM_END) { 115 D1(printk(KERN_DEBUG "final deflate returned %d\n", ret)); 116 ret = -1; 117 goto out; 118 } 119 120 if (def_strm.total_out >= def_strm.total_in) { 121 D1(printk(KERN_DEBUG "zlib compressed %ld bytes into %ld; failing\n", 122 def_strm.total_in, def_strm.total_out)); 123 ret = -1; 124 goto out; 125 } 126 127 D1(printk(KERN_DEBUG "zlib compressed %ld bytes into %ld\n", 128 def_strm.total_in, def_strm.total_out)); 129 130 *dstlen = def_strm.total_out; 131 *sourcelen = def_strm.total_in; 132 ret = 0; 133 out: 134 up(&deflate_sem); 135 return ret; 136 } 137 138 int jffs2_zlib_decompress(unsigned char *data_in, unsigned char *cpage_out, 139 uint32_t srclen, uint32_t destlen, void *model) 140 { 141 int ret; 142 int wbits = MAX_WBITS; 143 144 down(&inflate_sem); 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 up(&inflate_sem); 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 up(&inflate_sem); 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