dev/disk_image.cc

   1 /*
   2  * Copyright (c) 2003 The Regents of The University of Michigan
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions are
   7  * met: redistributions of source code must retain the above copyright
   8  * notice, this list of conditions and the following disclaimer;
   9  * redistributions in binary form must reproduce the above copyright
  10  * notice, this list of conditions and the following disclaimer in the
  11  * documentation and/or other materials provided with the distribution;
  12  * neither the name of the copyright holders nor the names of its
  13  * contributors may be used to endorse or promote products derived from
  14  * this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  17  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  18  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  19  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  20  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  21  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  22  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  26  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 /* @file
  30  * Disk Image Definitions
  31  */
  32
  33 #include <sys/types.h>
  34 #include <sys/uio.h>
  35 #include <errno.h>
  36 #include <string.h>
  37 #include <unistd.h>
  38
  39 #include <cstdio>
  40 #include <fstream>
  41 #include <string>
  42
  43 #include "disk_image.hh"
  44 #include "misc.hh"
  45 #include "trace.hh"
  46 #include "sim_exit.hh"
  47 #include "callback.hh"
  48
  49 using namespace std;
  50
  51 ////////////////////////////////////////////////////////////////////////
  52 //
  53 // Raw Disk image
  54 //
  55 RawDiskImage::RawDiskImage(const string &name, const string &filename,
  56                            bool rd_only)
  57     : DiskImage(name), disk_size(0)
  58 { open(filename, rd_only); }
  59
  60 RawDiskImage::~RawDiskImage()
  61 { close(); }
  62
  63 void
  64 RawDiskImage::open(const string &filename, bool rd_only)
  65 {
  66     if (!filename.empty()) {
  67         initialized = true;
  68         readonly = rd_only;
  69         file = filename;
  70
  71         ios::openmode mode = ios::in | ios::binary;
  72         if (!readonly)
  73             mode |= ios::out;
  74         stream.open(file.c_str(), mode);
  75         if (!stream.is_open())
  76             panic("Error opening %s", filename);
  77     }
  78 }
  79
  80 void
  81 RawDiskImage::close()
  82 {
  83     stream.close();
  84 }
  85
  86 off_t
  87 RawDiskImage::size() const
  88 {
  89     if (disk_size == 0) {
  90         if (!stream.is_open())
  91             panic("file not open!\n");
  92         stream.seekg(0, ios::end);
  93         disk_size = stream.tellg();
  94     }
  95
  96     return disk_size / SectorSize;
  97 }
  98
  99 off_t
 100 RawDiskImage::read(uint8_t *data, off_t offset) const
 101 {
 102     if (!initialized)
 103         panic("RawDiskImage not initialized");
 104
 105     if (!stream.is_open())
 106         panic("file not open!\n");
 107
 108     if (stream.seekg(offset * SectorSize, ios::beg) < 0)
 109         panic("Could not seek to location in file");
 110
 111     off_t pos = stream.tellg();
 112     stream.read((char *)data, SectorSize);
 113
 114     DPRINTF(DiskImageRead, "read: offset=%d\n", (uint64_t)offset);
 115     DDUMP(DiskImageRead, data, SectorSize);
 116
 117     return stream.tellg() - pos;
 118 }
 119
 120 off_t
 121 RawDiskImage::write(const uint8_t *data, off_t offset)
 122 {
 123     if (!initialized)
 124         panic("RawDiskImage not initialized");
 125
 126     if (readonly)
 127         panic("Cannot write to a read only disk image");
 128
 129     if (!stream.is_open())
 130         panic("file not open!\n");
 131
 132     if (stream.seekp(offset * SectorSize, ios::beg) < 0)
 133         panic("Could not seek to location in file");
 134
 135     DPRINTF(DiskImageWrite, "write: offset=%d\n", (uint64_t)offset);
 136     DDUMP(DiskImageWrite, data, SectorSize);
 137
 138     off_t pos = stream.tellp();
 139     stream.write((const char *)data, SectorSize);
 140     return stream.tellp() - pos;
 141 }
 142
 143 DEFINE_SIM_OBJECT_CLASS_NAME("DiskImage", DiskImage)
 144
 145 BEGIN_DECLARE_SIM_OBJECT_PARAMS(RawDiskImage)
 146
 147     Param<string> image_file;
 148     Param<bool> read_only;
 149
 150 END_DECLARE_SIM_OBJECT_PARAMS(RawDiskImage)
 151
 152 BEGIN_INIT_SIM_OBJECT_PARAMS(RawDiskImage)
 153
 154     INIT_PARAM(image_file, "disk image file"),
 155     INIT_PARAM_DFLT(read_only, "read only image", false)
 156
 157 END_INIT_SIM_OBJECT_PARAMS(RawDiskImage)
 158
 159
 160 CREATE_SIM_OBJECT(RawDiskImage)
 161 {
 162     return new RawDiskImage(getInstanceName(), image_file, read_only);
 163 }
 164
 165 REGISTER_SIM_OBJECT("RawDiskImage", RawDiskImage)
 166
 167 ////////////////////////////////////////////////////////////////////////
 168 //
 169 // Copy on Write Disk image
 170 //
 171 const int CowDiskImage::VersionMajor = 1;
 172 const int CowDiskImage::VersionMinor = 0;
 173
 174 CowDiskImage::CowDiskImage(const string &name, DiskImage *kid, int hash_size)
 175     : DiskImage(name), child(kid), table(NULL)
 176 { init(hash_size); }
 177
 178 class CowDiskCallback : public Callback
 179 {
 180   private:
 181     CowDiskImage *image;
 182
 183   public:
 184     CowDiskCallback(CowDiskImage *i) : image(i) {}
 185     void process() { image->save(); delete this; }
 186 };
 187
 188 CowDiskImage::CowDiskImage(const string &name, DiskImage *kid, int hash_size,
 189                            const string &file, bool read_only)
 190     : DiskImage(name), filename(file), child(kid), table(NULL)
 191 {
 192     if (!open()) {
 193         assert(!read_only && "why have a non-existent read only file?");
 194         init(hash_size);
 195     }
 196
 197     if (!read_only)
 198         registerExitCallback(new CowDiskCallback(this));
 199 }
 200
 201 CowDiskImage::~CowDiskImage()
 202 {
 203     SectorTable::iterator i = table->begin();
 204     SectorTable::iterator end = table->end();
 205
 206     while (i != end) {
 207         delete (*i).second;
 208         ++i;
 209     }
 210 }
 211
 212 void
 213 SafeRead(ifstream &stream, void *data, int count)
 214 {
 215     stream.read((char *)data, count);
 216     if (!stream.is_open())
 217         panic("file not open");
 218
 219     if (stream.eof())
 220         panic("premature end-of-file");
 221
 222     if (stream.bad() || stream.fail())
 223         panic("error reading cowdisk image");
 224 }
 225
 226 template<class T>
 227 void
 228 SafeRead(ifstream &stream, T &data)
 229 { SafeRead(stream, &data, sizeof(data)); }
 230
 231 bool
 232 CowDiskImage::open()
 233 {
 234     ifstream stream(filename.c_str());
 235     if (!stream.is_open())
 236         return false;
 237
 238     if (stream.fail() || stream.bad())
 239         panic("Error opening %s", filename);
 240
 241     uint64_t magic;
 242     SafeRead(stream, magic);
 243
 244     if (memcmp(&magic, "COWDISK!", sizeof(magic)) != 0)
 245         panic("Could not open %s: Invalid magic", filename);
 246
 247     uint32_t major, minor;
 248     SafeRead(stream, major);
 249     SafeRead(stream, minor);
 250
 251     if (major != VersionMajor && minor != VersionMinor)
 252         panic("Could not open %s: invalid version %d.%d != %d.%d",
 253               filename, major, minor, VersionMajor, VersionMinor);
 254
 255     uint64_t sector_count;
 256     SafeRead(stream, sector_count);
 257     table = new SectorTable(sector_count);
 258
 259
 260     for (uint64_t i = 0; i < sector_count; i++) {
 261         uint64_t offset;
 262         SafeRead(stream, offset);
 263
 264         Sector *sector = new Sector;
 265         SafeRead(stream, sector, sizeof(Sector));
 266
 267         assert(table->find(offset) == table->end());
 268         (*table)[offset] = sector;
 269     }
 270
 271     stream.close();
 272
 273     initialized = true;
 274     return true;
 275 }
 276
 277 void
 278 CowDiskImage::init(int hash_size)
 279 {
 280     table = new SectorTable(hash_size);
 281
 282     initialized = true;
 283 }
 284
 285 void
 286 SafeWrite(ofstream &stream, const void *data, int count)
 287 {
 288     stream.write((const char *)data, count);
 289     if (!stream.is_open())
 290         panic("file not open");
 291
 292     if (stream.eof())
 293         panic("premature end-of-file");
 294
 295     if (stream.bad() || stream.fail())
 296         panic("error reading cowdisk image");
 297 }
 298
 299 template<class T>
 300 void
 301 SafeWrite(ofstream &stream, const T &data)
 302 { SafeWrite(stream, &data, sizeof(data)); }
 303
 304 void
 305 CowDiskImage::save()
 306 {
 307     if (!initialized)
 308         panic("RawDiskImage not initialized");
 309
 310     ofstream stream(filename.c_str());
 311     if (!stream.is_open() || stream.fail() || stream.bad())
 312         panic("Error opening %s", filename);
 313
 314     uint64_t magic;
 315     memcpy(&magic, "COWDISK!", sizeof(magic));
 316     SafeWrite(stream, magic);
 317
 318     SafeWrite(stream, (uint32_t)VersionMajor);
 319     SafeWrite(stream, (uint32_t)VersionMinor);
 320     SafeWrite(stream, (uint64_t)table->size());
 321
 322     uint64_t size = table->size();
 323     SectorTable::iterator iter = table->begin();
 324     SectorTable::iterator end = table->end();
 325
 326     for (uint64_t i = 0; i < size; i++) {
 327         if (iter == end)
 328             panic("Incorrect Table Size during save of COW disk image");
 329
 330         SafeWrite(stream, (uint64_t)(*iter).first);
 331         SafeWrite(stream, (*iter).second->data, sizeof(Sector));
 332         ++iter;
 333     }
 334
 335     stream.close();
 336 }
 337
 338 void
 339 CowDiskImage::writeback()
 340 {
 341     SectorTable::iterator i = table->begin();
 342     SectorTable::iterator end = table->end();
 343
 344     while (i != end) {
 345         child->write((*i).second->data, (*i).first);
 346         ++i;
 347     }
 348 }
 349
 350 off_t
 351 CowDiskImage::size() const
 352 { return child->size(); }
 353
 354 off_t
 355 CowDiskImage::read(uint8_t *data, off_t offset) const
 356 {
 357     if (!initialized)
 358         panic("CowDiskImage not initialized");
 359
 360     if (offset > size())
 361         panic("access out of bounds");
 362
 363     SectorTable::const_iterator i = table->find(offset);
 364     if (i == table->end())
 365         return child->read(data, offset);
 366     else {
 367         memcpy(data, (*i).second->data, SectorSize);
 368         DPRINTF(DiskImageRead, "read: offset=%d\n", (uint64_t)offset);
 369         DDUMP(DiskImageRead, data, SectorSize);
 370         return SectorSize;
 371     }
 372 }
 373
 374 off_t
 375 CowDiskImage::write(const uint8_t *data, off_t offset)
 376 {
 377     if (!initialized)
 378         panic("RawDiskImage not initialized");
 379
 380     if (offset > size())
 381         panic("access out of bounds");
 382
 383     SectorTable::iterator i = table->find(offset);
 384     if (i == table->end()) {
 385         Sector *sector = new Sector;
 386         memcpy(sector, data, SectorSize);
 387         table->insert(make_pair(offset, sector));
 388     } else {
 389         memcpy((*i).second->data, data, SectorSize);
 390     }
 391
 392     DPRINTF(DiskImageWrite, "write: offset=%d\n", (uint64_t)offset);
 393     DDUMP(DiskImageWrite, data, SectorSize);
 394
 395     return SectorSize;
 396 }
 397
 398 BEGIN_DECLARE_SIM_OBJECT_PARAMS(CowDiskImage)
 399
 400     SimObjectParam<DiskImage *> child;
 401     Param<string> image_file;
 402     Param<int> table_size;
 403     Param<bool> read_only;
 404
 405 END_DECLARE_SIM_OBJECT_PARAMS(CowDiskImage)
 406
 407 BEGIN_INIT_SIM_OBJECT_PARAMS(CowDiskImage)
 408
 409     INIT_PARAM(child, "child image"),
 410     INIT_PARAM_DFLT(image_file, "disk image file", ""),
 411     INIT_PARAM_DFLT(table_size, "initial table size", 65536),
 412     INIT_PARAM_DFLT(read_only, "don't write back to the copy-on-write file",
 413                     true)
 414
 415 END_INIT_SIM_OBJECT_PARAMS(CowDiskImage)
 416
 417
 418 CREATE_SIM_OBJECT(CowDiskImage)
 419 {
 420     if (((string)image_file).empty())
 421         return new CowDiskImage(getInstanceName(), child, table_size);
 422     else
 423         return new CowDiskImage(getInstanceName(), child, table_size,
 424                                 image_file, read_only);
 425 }
 426
 427 REGISTER_SIM_OBJECT("CowDiskImage", CowDiskImage)