src/dev/disk_image.cc

   1 /*
   2  * Copyright (c) 2001-2005 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  * Authors: Nathan Binkert
  29  */
  30
  31 /** @file
  32  * Disk Image Definitions
  33  */
  34
  35 #include <sys/types.h>
  36 #include <sys/uio.h>
  37 #include <errno.h>
  38 #include <unistd.h>
  39
  40 #include <cstring>
  41 #include <fstream>
  42 #include <string>
  43
  44 #include "base/callback.hh"
  45 #include "base/misc.hh"
  46 #include "base/trace.hh"
  47 #include "dev/disk_image.hh"
  48 #include "sim/builder.hh"
  49 #include "sim/sim_exit.hh"
  50 #include "sim/byteswap.hh"
  51
  52 using namespace std;
  53
  54 ////////////////////////////////////////////////////////////////////////
  55 //
  56 // Raw Disk image
  57 //
  58 RawDiskImage::RawDiskImage(const string &name, const string &filename,
  59                            bool rd_only)
  60     : DiskImage(name), disk_size(0)
  61 { open(filename, rd_only); }
  62
  63 RawDiskImage::~RawDiskImage()
  64 { close(); }
  65
  66 void
  67 RawDiskImage::open(const string &filename, bool rd_only)
  68 {
  69     if (!filename.empty()) {
  70         initialized = true;
  71         readonly = rd_only;
  72         file = filename;
  73
  74         ios::openmode mode = ios::in | ios::binary;
  75         if (!readonly)
  76             mode |= ios::out;
  77         stream.open(file.c_str(), mode);
  78         if (!stream.is_open())
  79             panic("Error opening %s", filename);
  80     }
  81 }
  82
  83 void
  84 RawDiskImage::close()
  85 {
  86     stream.close();
  87 }
  88
  89 off_t
  90 RawDiskImage::size() const
  91 {
  92     if (disk_size == 0) {
  93         if (!stream.is_open())
  94             panic("file not open!\n");
  95         stream.seekg(0, ios::end);
  96         disk_size = stream.tellg();
  97     }
  98
  99     return disk_size / SectorSize;
 100 }
 101
 102 off_t
 103 RawDiskImage::read(uint8_t *data, off_t offset) const
 104 {
 105     if (!initialized)
 106         panic("RawDiskImage not initialized");
 107
 108     if (!stream.is_open())
 109         panic("file not open!\n");
 110
 111     if (stream.seekg(offset * SectorSize, ios::beg) < 0)
 112         panic("Could not seek to location in file");
 113
 114     streampos pos = stream.tellg();
 115     stream.read((char *)data, SectorSize);
 116
 117     DPRINTF(DiskImageRead, "read: offset=%d\n", (uint64_t)offset);
 118     DDUMP(DiskImageRead, data, SectorSize);
 119
 120     return stream.tellg() - pos;
 121 }
 122
 123 off_t
 124 RawDiskImage::write(const uint8_t *data, off_t offset)
 125 {
 126     if (!initialized)
 127         panic("RawDiskImage not initialized");
 128
 129     if (readonly)
 130         panic("Cannot write to a read only disk image");
 131
 132     if (!stream.is_open())
 133         panic("file not open!\n");
 134
 135     if (stream.seekp(offset * SectorSize, ios::beg) < 0)
 136         panic("Could not seek to location in file");
 137
 138     DPRINTF(DiskImageWrite, "write: offset=%d\n", (uint64_t)offset);
 139     DDUMP(DiskImageWrite, data, SectorSize);
 140
 141     streampos pos = stream.tellp();
 142     stream.write((const char *)data, SectorSize);
 143     return stream.tellp() - pos;
 144 }
 145
 146 DEFINE_SIM_OBJECT_CLASS_NAME("DiskImage", DiskImage)
 147
 148 BEGIN_DECLARE_SIM_OBJECT_PARAMS(RawDiskImage)
 149
 150     Param<string> image_file;
 151     Param<bool> read_only;
 152
 153 END_DECLARE_SIM_OBJECT_PARAMS(RawDiskImage)
 154
 155 BEGIN_INIT_SIM_OBJECT_PARAMS(RawDiskImage)
 156
 157     INIT_PARAM(image_file, "disk image file"),
 158     INIT_PARAM_DFLT(read_only, "read only image", false)
 159
 160 END_INIT_SIM_OBJECT_PARAMS(RawDiskImage)
 161
 162
 163 CREATE_SIM_OBJECT(RawDiskImage)
 164 {
 165     return new RawDiskImage(getInstanceName(), image_file, read_only);
 166 }
 167
 168 REGISTER_SIM_OBJECT("RawDiskImage", RawDiskImage)
 169
 170 ////////////////////////////////////////////////////////////////////////
 171 //
 172 // Copy on Write Disk image
 173 //
 174 const int CowDiskImage::VersionMajor = 1;
 175 const int CowDiskImage::VersionMinor = 0;
 176
 177 CowDiskImage::CowDiskImage(const string &name, DiskImage *kid, int hash_size)
 178     : DiskImage(name), child(kid), table(NULL)
 179 { init(hash_size); }
 180
 181 class CowDiskCallback : public Callback
 182 {
 183   private:
 184     CowDiskImage *image;
 185
 186   public:
 187     CowDiskCallback(CowDiskImage *i) : image(i) {}
 188     void process() { image->save(); delete this; }
 189 };
 190
 191 CowDiskImage::CowDiskImage(const string &name, DiskImage *kid, int hash_size,
 192                            const string &file, bool read_only)
 193     : DiskImage(name), filename(file), child(kid), table(NULL)
 194 {
 195     if (!open(filename)) {
 196         assert(!read_only && "why have a non-existent read only file?");
 197         init(hash_size);
 198     }
 199
 200     if (!read_only)
 201         registerExitCallback(new CowDiskCallback(this));
 202 }
 203
 204 CowDiskImage::~CowDiskImage()
 205 {
 206     SectorTable::iterator i = table->begin();
 207     SectorTable::iterator end = table->end();
 208
 209     while (i != end) {
 210         delete (*i).second;
 211         ++i;
 212     }
 213 }
 214
 215 void
 216 SafeRead(ifstream &stream, void *data, int count)
 217 {
 218     stream.read((char *)data, count);
 219     if (!stream.is_open())
 220         panic("file not open");
 221
 222     if (stream.eof())
 223         panic("premature end-of-file");
 224
 225     if (stream.bad() || stream.fail())
 226         panic("error reading cowdisk image");
 227 }
 228
 229 template<class T>
 230 void
 231 SafeRead(ifstream &stream, T &data)
 232 {
 233     SafeRead(stream, &data, sizeof(data));
 234 }
 235
 236 template<class T>
 237 void
 238 SafeReadSwap(ifstream &stream, T &data)
 239 {
 240     SafeRead(stream, &data, sizeof(data));
 241     data = letoh(data); //is this the proper byte order conversion?
 242 }
 243
 244 bool
 245 CowDiskImage::open(const string &file)
 246 {
 247     ifstream stream(file.c_str());
 248     if (!stream.is_open())
 249         return false;
 250
 251     if (stream.fail() || stream.bad())
 252         panic("Error opening %s", file);
 253
 254     uint64_t magic;
 255     SafeRead(stream, magic);
 256
 257     if (memcmp(&magic, "COWDISK!", sizeof(magic)) != 0)
 258         panic("Could not open %s: Invalid magic", file);
 259
 260     uint32_t major, minor;
 261     SafeReadSwap(stream, major);
 262     SafeReadSwap(stream, minor);
 263
 264     if (major != VersionMajor && minor != VersionMinor)
 265         panic("Could not open %s: invalid version %d.%d != %d.%d",
 266               file, major, minor, VersionMajor, VersionMinor);
 267
 268     uint64_t sector_count;
 269     SafeReadSwap(stream, sector_count);
 270     table = new SectorTable(sector_count);
 271
 272
 273     for (uint64_t i = 0; i < sector_count; i++) {
 274         uint64_t offset;
 275         SafeReadSwap(stream, offset);
 276
 277         Sector *sector = new Sector;
 278         SafeRead(stream, sector, sizeof(Sector));
 279
 280         assert(table->find(offset) == table->end());
 281         (*table)[offset] = sector;
 282     }
 283
 284     stream.close();
 285
 286     initialized = true;
 287     return true;
 288 }
 289
 290 void
 291 CowDiskImage::init(int hash_size)
 292 {
 293     table = new SectorTable(hash_size);
 294
 295     initialized = true;
 296 }
 297
 298 void
 299 SafeWrite(ofstream &stream, const void *data, int count)
 300 {
 301     stream.write((const char *)data, count);
 302     if (!stream.is_open())
 303         panic("file not open");
 304
 305     if (stream.eof())
 306         panic("premature end-of-file");
 307
 308     if (stream.bad() || stream.fail())
 309         panic("error reading cowdisk image");
 310 }
 311
 312 template<class T>
 313 void
 314 SafeWrite(ofstream &stream, const T &data)
 315 {
 316     SafeWrite(stream, &data, sizeof(data));
 317 }
 318
 319 template<class T>
 320 void
 321 SafeWriteSwap(ofstream &stream, const T &data)
 322 {
 323     T swappeddata = letoh(data); //is this the proper byte order conversion?
 324     SafeWrite(stream, &swappeddata, sizeof(data));
 325 }
 326 void
 327 CowDiskImage::save()
 328 {
 329     save(filename);
 330 }
 331
 332 void
 333 CowDiskImage::save(const string &file)
 334 {
 335     if (!initialized)
 336         panic("RawDiskImage not initialized");
 337
 338     ofstream stream(file.c_str());
 339     if (!stream.is_open() || stream.fail() || stream.bad())
 340         panic("Error opening %s", file);
 341
 342     uint64_t magic;
 343     memcpy(&magic, "COWDISK!", sizeof(magic));
 344     SafeWrite(stream, magic);
 345
 346     SafeWriteSwap(stream, (uint32_t)VersionMajor);
 347     SafeWriteSwap(stream, (uint32_t)VersionMinor);
 348     SafeWriteSwap(stream, (uint64_t)table->size());
 349
 350     uint64_t size = table->size();
 351     SectorTable::iterator iter = table->begin();
 352     SectorTable::iterator end = table->end();
 353
 354     for (uint64_t i = 0; i < size; i++) {
 355         if (iter == end)
 356             panic("Incorrect Table Size during save of COW disk image");
 357
 358         SafeWriteSwap(stream, (uint64_t)(*iter).first);
 359         SafeWrite(stream, (*iter).second->data, sizeof(Sector));
 360         ++iter;
 361     }
 362
 363     stream.close();
 364 }
 365
 366 void
 367 CowDiskImage::writeback()
 368 {
 369     SectorTable::iterator i = table->begin();
 370     SectorTable::iterator end = table->end();
 371
 372     while (i != end) {
 373         child->write((*i).second->data, (*i).first);
 374         ++i;
 375     }
 376 }
 377
 378 off_t
 379 CowDiskImage::size() const
 380 { return child->size(); }
 381
 382 off_t
 383 CowDiskImage::read(uint8_t *data, off_t offset) const
 384 {
 385     if (!initialized)
 386         panic("CowDiskImage not initialized");
 387
 388     if (offset > size())
 389         panic("access out of bounds");
 390
 391     SectorTable::const_iterator i = table->find(offset);
 392     if (i == table->end())
 393         return child->read(data, offset);
 394     else {
 395         memcpy(data, (*i).second->data, SectorSize);
 396         DPRINTF(DiskImageRead, "read: offset=%d\n", (uint64_t)offset);
 397         DDUMP(DiskImageRead, data, SectorSize);
 398         return SectorSize;
 399     }
 400 }
 401
 402 off_t
 403 CowDiskImage::write(const uint8_t *data, off_t offset)
 404 {
 405     if (!initialized)
 406         panic("RawDiskImage not initialized");
 407
 408     if (offset > size())
 409         panic("access out of bounds");
 410
 411     SectorTable::iterator i = table->find(offset);
 412     if (i == table->end()) {
 413         Sector *sector = new Sector;
 414         memcpy(sector, data, SectorSize);
 415         table->insert(make_pair(offset, sector));
 416     } else {
 417         memcpy((*i).second->data, data, SectorSize);
 418     }
 419
 420     DPRINTF(DiskImageWrite, "write: offset=%d\n", (uint64_t)offset);
 421     DDUMP(DiskImageWrite, data, SectorSize);
 422
 423     return SectorSize;
 424 }
 425
 426 void
 427 CowDiskImage::serialize(ostream &os)
 428 {
 429     string cowFilename = name() + ".cow";
 430     SERIALIZE_SCALAR(cowFilename);
 431     save(Checkpoint::dir() + "/" + cowFilename);
 432 }
 433
 434 void
 435 CowDiskImage::unserialize(Checkpoint *cp, const string &section)
 436 {
 437     string cowFilename;
 438     UNSERIALIZE_SCALAR(cowFilename);
 439     cowFilename = cp->cptDir + "/" + cowFilename;
 440     open(cowFilename);
 441 }
 442
 443 BEGIN_DECLARE_SIM_OBJECT_PARAMS(CowDiskImage)
 444
 445     SimObjectParam<DiskImage *> child;
 446     Param<string> image_file;
 447     Param<int> table_size;
 448     Param<bool> read_only;
 449
 450 END_DECLARE_SIM_OBJECT_PARAMS(CowDiskImage)
 451
 452 BEGIN_INIT_SIM_OBJECT_PARAMS(CowDiskImage)
 453
 454     INIT_PARAM(child, "child image"),
 455     INIT_PARAM_DFLT(image_file, "disk image file", ""),
 456     INIT_PARAM_DFLT(table_size, "initial table size", 65536),
 457     INIT_PARAM_DFLT(read_only, "don't write back to the copy-on-write file",
 458                     true)
 459
 460 END_INIT_SIM_OBJECT_PARAMS(CowDiskImage)
 461
 462
 463 CREATE_SIM_OBJECT(CowDiskImage)
 464 {
 465     if (((string)image_file).empty())
 466         return new CowDiskImage(getInstanceName(), child, table_size);
 467     else
 468         return new CowDiskImage(getInstanceName(), child, table_size,
 469                                 image_file, read_only);
 470 }
 471
 472 REGISTER_SIM_OBJECT("CowDiskImage", CowDiskImage)