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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 18 19 #include <linux/kernel.h> 20 #include <linux/zlib.h> 21 #include <linux/zutil.h> 22 #include "nodelist.h" 23 #include "compr.h" 24 25 /* Plan: call deflate() with avail_in == *sourcelen, 26 avail_out = *dstlen - 12 and flush == Z_FINISH. 27 If it doesn't manage to finish, call it again with 28 avail_in == 0 and avail_out set to the remaining 12 29 bytes for it to clean up. 30 Q: Is 12 bytes sufficient? 31 */ 32 #define STREAM_END_SPACE 12 33 34 static DEFINE_MUTEX(deflate_mutex); 35 static DEFINE_MUTEX(inflate_mutex); 36 static z_stream inf_strm, def_strm; 37 38 #ifdef __KERNEL__ /* Linux-only */ 39 #include <linux/vmalloc.h> 40 #include <linux/init.h> 41 #include <linux/mutex.h> 42 43 static int __init alloc_workspaces(void) 44 { 45 def_strm.workspace = vmalloc(zlib_deflate_workspacesize(MAX_WBITS, 46 MAX_MEM_LEVEL)); 47 if (!def_strm.workspace) 48 return -ENOMEM; 49 50 jffs2_dbg(1, "Allocated %d bytes for deflate workspace\n", 51 zlib_deflate_workspacesize(MAX_WBITS, MAX_MEM_LEVEL)); 52 inf_strm.workspace = vmalloc(zlib_inflate_workspacesize()); 53 if (!inf_strm.workspace) { 54 vfree(def_strm.workspace); 55 return -ENOMEM; 56 } 57 jffs2_dbg(1, "Allocated %d bytes for inflate workspace\n", 58 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 static int jffs2_zlib_compress(unsigned char *data_in, 73 unsigned char *cpage_out, 74 uint32_t *sourcelen, uint32_t *dstlen) 75 { 76 int ret; 77 78 if (*dstlen <= STREAM_END_SPACE) 79 return -1; 80 81 mutex_lock(&deflate_mutex); 82 83 if (Z_OK != zlib_deflateInit(&def_strm, 3)) { 84 pr_warn("deflateInit failed\n"); 85 mutex_unlock(&deflate_mutex); 86 return -1; 87 } 88 89 def_strm.next_in = data_in; 90 def_strm.total_in = 0; 91 92 def_strm.next_out = cpage_out; 93 def_strm.total_out = 0; 94 95 while (def_strm.total_out < *dstlen - STREAM_END_SPACE && def_strm.total_in < *sourcelen) { 96 def_strm.avail_out = *dstlen - (def_strm.total_out + STREAM_END_SPACE); 97 def_strm.avail_in = min((unsigned)(*sourcelen-def_strm.total_in), def_strm.avail_out); 98 jffs2_dbg(1, "calling deflate with avail_in %d, avail_out %d\n", 99 def_strm.avail_in, def_strm.avail_out); 100 ret = zlib_deflate(&def_strm, Z_PARTIAL_FLUSH); 101 jffs2_dbg(1, "deflate returned with avail_in %d, avail_out %d, total_in %ld, total_out %ld\n", 102 def_strm.avail_in, def_strm.avail_out, 103 def_strm.total_in, def_strm.total_out); 104 if (ret != Z_OK) { 105 jffs2_dbg(1, "deflate in loop returned %d\n", ret); 106 zlib_deflateEnd(&def_strm); 107 mutex_unlock(&deflate_mutex); 108 return -1; 109 } 110 } 111 def_strm.avail_out += STREAM_END_SPACE; 112 def_strm.avail_in = 0; 113 ret = zlib_deflate(&def_strm, Z_FINISH); 114 zlib_deflateEnd(&def_strm); 115 116 if (ret != Z_STREAM_END) { 117 jffs2_dbg(1, "final deflate returned %d\n", ret); 118 ret = -1; 119 goto out; 120 } 121 122 if (def_strm.total_out >= def_strm.total_in) { 123 jffs2_dbg(1, "zlib compressed %ld bytes into %ld; failing\n", 124 def_strm.total_in, def_strm.total_out); 125 ret = -1; 126 goto out; 127 } 128 129 jffs2_dbg(1, "zlib compressed %ld bytes into %ld\n", 130 def_strm.total_in, def_strm.total_out); 131 132 *dstlen = def_strm.total_out; 133 *sourcelen = def_strm.total_in; 134 ret = 0; 135 out: 136 mutex_unlock(&deflate_mutex); 137 return ret; 138 } 139 140 static int jffs2_zlib_decompress(unsigned char *data_in, 141 unsigned char *cpage_out, 142 uint32_t srclen, uint32_t destlen) 143 { 144 int ret; 145 int wbits = MAX_WBITS; 146 147 mutex_lock(&inflate_mutex); 148 149 inf_strm.next_in = data_in; 150 inf_strm.avail_in = srclen; 151 inf_strm.total_in = 0; 152 153 inf_strm.next_out = cpage_out; 154 inf_strm.avail_out = destlen; 155 inf_strm.total_out = 0; 156 157 /* If it's deflate, and it's got no preset dictionary, then 158 we can tell zlib to skip the adler32 check. */ 159 if (srclen > 2 && !(data_in[1] & PRESET_DICT) && 160 ((data_in[0] & 0x0f) == Z_DEFLATED) && 161 !(((data_in[0]<<8) + data_in[1]) % 31)) { 162 163 jffs2_dbg(2, "inflate skipping adler32\n"); 164 wbits = -((data_in[0] >> 4) + 8); 165 inf_strm.next_in += 2; 166 inf_strm.avail_in -= 2; 167 } else { 168 /* Let this remain D1 for now -- it should never happen */ 169 jffs2_dbg(1, "inflate not skipping adler32\n"); 170 } 171 172 173 if (Z_OK != zlib_inflateInit2(&inf_strm, wbits)) { 174 pr_warn("inflateInit failed\n"); 175 mutex_unlock(&inflate_mutex); 176 return 1; 177 } 178 179 while((ret = zlib_inflate(&inf_strm, Z_FINISH)) == Z_OK) 180 ; 181 if (ret != Z_STREAM_END) { 182 pr_notice("inflate returned %d\n", ret); 183 } 184 zlib_inflateEnd(&inf_strm); 185 mutex_unlock(&inflate_mutex); 186 return 0; 187 } 188 189 static struct jffs2_compressor jffs2_zlib_comp = { 190 .priority = JFFS2_ZLIB_PRIORITY, 191 .name = "zlib", 192 .compr = JFFS2_COMPR_ZLIB, 193 .compress = &jffs2_zlib_compress, 194 .decompress = &jffs2_zlib_decompress, 195 #ifdef JFFS2_ZLIB_DISABLED 196 .disabled = 1, 197 #else 198 .disabled = 0, 199 #endif 200 }; 201 202 int __init jffs2_zlib_init(void) 203 { 204 int ret; 205 206 ret = alloc_workspaces(); 207 if (ret) 208 return ret; 209 210 ret = jffs2_register_compressor(&jffs2_zlib_comp); 211 if (ret) 212 free_workspaces(); 213 214 return ret; 215 } 216 217 void jffs2_zlib_exit(void) 218 { 219 jffs2_unregister_compressor(&jffs2_zlib_comp); 220 free_workspaces(); 221 } 222