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 <unistd.h>
  38
  39 #include <cerrno>
  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 "debug/DiskImageRead.hh"
  48 #include "debug/DiskImageWrite.hh"
  49 #include "dev/disk_image.hh"
  50 #include "sim/byteswap.hh"
  51 #include "sim/sim_exit.hh"
  52
  53 using namespace std;
  54
  55 ////////////////////////////////////////////////////////////////////////
  56 //
  57 // Raw Disk image
  58 //
  59 RawDiskImage::RawDiskImage(const Params* p)
  60     : DiskImage(p), disk_size(0)
  61 { open(p->image_file, p->read_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 std::streampos
  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 std::streampos
 103 RawDiskImage::read(uint8_t *data, std::streampos 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     stream.seekg(offset * SectorSize, ios::beg);
 112     if (!stream.good())
 113         panic("Could not seek to location in file");
 114
 115     streampos pos = stream.tellg();
 116     stream.read((char *)data, SectorSize);
 117
 118     DPRINTF(DiskImageRead, "read: offset=%d\n", (uint64_t)offset);
 119     DDUMP(DiskImageRead, data, SectorSize);
 120
 121     return stream.tellg() - pos;
 122 }
 123
 124 std::streampos
 125 RawDiskImage::write(const uint8_t *data, std::streampos offset)
 126 {
 127     if (!initialized)
 128         panic("RawDiskImage not initialized");
 129
 130     if (readonly)
 131         panic("Cannot write to a read only disk image");
 132
 133     if (!stream.is_open())
 134         panic("file not open!\n");
 135
 136     stream.seekp(offset * SectorSize, ios::beg);
 137     if (!stream.good())
 138         panic("Could not seek to location in file");
 139
 140     DPRINTF(DiskImageWrite, "write: offset=%d\n", (uint64_t)offset);
 141     DDUMP(DiskImageWrite, data, SectorSize);
 142
 143     streampos pos = stream.tellp();
 144     stream.write((const char *)data, SectorSize);
 145     return stream.tellp() - pos;
 146 }
 147
 148 RawDiskImage *
 149 RawDiskImageParams::create()
 150 {
 151     return new RawDiskImage(this);
 152 }
 153
 154 ////////////////////////////////////////////////////////////////////////
 155 //
 156 // Copy on Write Disk image
 157 //
 158 const uint32_t CowDiskImage::VersionMajor = 1;
 159 const uint32_t CowDiskImage::VersionMinor = 0;
 160
 161 class CowDiskCallback : public Callback
 162 {
 163   private:
 164     CowDiskImage *image;
 165
 166   public:
 167     CowDiskCallback(CowDiskImage *i) : image(i) {}
 168     void process() { image->save(); delete this; }
 169 };
 170
 171 CowDiskImage::CowDiskImage(const Params *p)
 172     : DiskImage(p), filename(p->image_file), child(p->child), table(NULL)
 173 {
 174     if (filename.empty()) {
 175         initSectorTable(p->table_size);
 176     } else {
 177         if (!open(filename)) {
 178             if (p->read_only)
 179                 fatal("could not open read-only file");
 180             initSectorTable(p->table_size);
 181         }
 182
 183         if (!p->read_only)
 184             registerExitCallback(new CowDiskCallback(this));
 185     }
 186 }
 187
 188 CowDiskImage::~CowDiskImage()
 189 {
 190     SectorTable::iterator i = table->begin();
 191     SectorTable::iterator end = table->end();
 192
 193     while (i != end) {
 194         delete (*i).second;
 195         ++i;
 196     }
 197 }
 198
 199 void
 200 SafeRead(ifstream &stream, void *data, int count)
 201 {
 202     stream.read((char *)data, count);
 203     if (!stream.is_open())
 204         panic("file not open");
 205
 206     if (stream.eof())
 207         panic("premature end-of-file");
 208
 209     if (stream.bad() || stream.fail())
 210         panic("error reading cowdisk image");
 211 }
 212
 213 template<class T>
 214 void
 215 SafeRead(ifstream &stream, T &data)
 216 {
 217     SafeRead(stream, &data, sizeof(data));
 218 }
 219
 220 template<class T>
 221 void
 222 SafeReadSwap(ifstream &stream, T &data)
 223 {
 224     SafeRead(stream, &data, sizeof(data));
 225     data = letoh(data); //is this the proper byte order conversion?
 226 }
 227
 228 bool
 229 CowDiskImage::open(const string &file)
 230 {
 231     ifstream stream(file.c_str());
 232     if (!stream.is_open())
 233         return false;
 234
 235     if (stream.fail() || stream.bad())
 236         panic("Error opening %s", file);
 237
 238     uint64_t magic;
 239     SafeRead(stream, magic);
 240
 241     if (memcmp(&magic, "COWDISK!", sizeof(magic)) != 0)
 242         panic("Could not open %s: Invalid magic", file);
 243
 244     uint32_t major, minor;
 245     SafeReadSwap(stream, major);
 246     SafeReadSwap(stream, minor);
 247
 248     if (major != VersionMajor && minor != VersionMinor)
 249         panic("Could not open %s: invalid version %d.%d != %d.%d",
 250               file, major, minor, VersionMajor, VersionMinor);
 251
 252     uint64_t sector_count;
 253     SafeReadSwap(stream, sector_count);
 254     table = new SectorTable(sector_count);
 255
 256
 257     for (uint64_t i = 0; i < sector_count; i++) {
 258         uint64_t offset;
 259         SafeReadSwap(stream, offset);
 260
 261         Sector *sector = new Sector;
 262         SafeRead(stream, sector, sizeof(Sector));
 263
 264         assert(table->find(offset) == table->end());
 265         (*table)[offset] = sector;
 266     }
 267
 268     stream.close();
 269
 270     initialized = true;
 271     return true;
 272 }
 273
 274 void
 275 CowDiskImage::initSectorTable(int hash_size)
 276 {
 277     table = new SectorTable(hash_size);
 278
 279     initialized = true;
 280 }
 281
 282 void
 283 SafeWrite(ofstream &stream, const void *data, int count)
 284 {
 285     stream.write((const char *)data, count);
 286     if (!stream.is_open())
 287         panic("file not open");
 288
 289     if (stream.eof())
 290         panic("premature end-of-file");
 291
 292     if (stream.bad() || stream.fail())
 293         panic("error reading cowdisk image");
 294 }
 295
 296 template<class T>
 297 void
 298 SafeWrite(ofstream &stream, const T &data)
 299 {
 300     SafeWrite(stream, &data, sizeof(data));
 301 }
 302
 303 template<class T>
 304 void
 305 SafeWriteSwap(ofstream &stream, const T &data)
 306 {
 307     T swappeddata = letoh(data); //is this the proper byte order conversion?
 308     SafeWrite(stream, &swappeddata, sizeof(data));
 309 }
 310 void
 311 CowDiskImage::save() const
 312 {
 313     save(filename);
 314 }
 315
 316 void
 317 CowDiskImage::save(const string &file) const
 318 {
 319     if (!initialized)
 320         panic("RawDiskImage not initialized");
 321
 322     ofstream stream(file.c_str());
 323     if (!stream.is_open() || stream.fail() || stream.bad())
 324         panic("Error opening %s", file);
 325
 326     uint64_t magic;
 327     memcpy(&magic, "COWDISK!", sizeof(magic));
 328     SafeWrite(stream, magic);
 329
 330     SafeWriteSwap(stream, (uint32_t)VersionMajor);
 331     SafeWriteSwap(stream, (uint32_t)VersionMinor);
 332     SafeWriteSwap(stream, (uint64_t)table->size());
 333
 334     uint64_t size = table->size();
 335     SectorTable::iterator iter = table->begin();
 336     SectorTable::iterator end = table->end();
 337
 338     for (uint64_t i = 0; i < size; i++) {
 339         if (iter == end)
 340             panic("Incorrect Table Size during save of COW disk image");
 341
 342         SafeWriteSwap(stream, (uint64_t)(*iter).first);
 343         SafeWrite(stream, (*iter).second->data, sizeof(Sector));
 344         ++iter;
 345     }
 346
 347     stream.close();
 348 }
 349
 350 void
 351 CowDiskImage::writeback()
 352 {
 353     SectorTable::iterator i = table->begin();
 354     SectorTable::iterator end = table->end();
 355
 356     while (i != end) {
 357         child->write((*i).second->data, (*i).first);
 358         ++i;
 359     }
 360 }
 361
 362 std::streampos
 363 CowDiskImage::size() const
 364 { return child->size(); }
 365
 366 std::streampos
 367 CowDiskImage::read(uint8_t *data, std::streampos offset) const
 368 {
 369     if (!initialized)
 370         panic("CowDiskImage not initialized");
 371
 372     if (offset > size())
 373         panic("access out of bounds");
 374
 375     SectorTable::const_iterator i = table->find(offset);
 376     if (i == table->end())
 377         return child->read(data, offset);
 378     else {
 379         memcpy(data, (*i).second->data, SectorSize);
 380         DPRINTF(DiskImageRead, "read: offset=%d\n", (uint64_t)offset);
 381         DDUMP(DiskImageRead, data, SectorSize);
 382         return SectorSize;
 383     }
 384 }
 385
 386 std::streampos
 387 CowDiskImage::write(const uint8_t *data, std::streampos offset)
 388 {
 389     if (!initialized)
 390         panic("RawDiskImage not initialized");
 391
 392     if (offset > size())
 393         panic("access out of bounds");
 394
 395     SectorTable::iterator i = table->find(offset);
 396     if (i == table->end()) {
 397         Sector *sector = new Sector;
 398         memcpy(sector, data, SectorSize);
 399         table->insert(make_pair(offset, sector));
 400     } else {
 401         memcpy((*i).second->data, data, SectorSize);
 402     }
 403
 404     DPRINTF(DiskImageWrite, "write: offset=%d\n", (uint64_t)offset);
 405     DDUMP(DiskImageWrite, data, SectorSize);
 406
 407     return SectorSize;
 408 }
 409
 410 void
 411 CowDiskImage::serialize(CheckpointOut &cp) const
 412 {
 413     string cowFilename = name() + ".cow";
 414     SERIALIZE_SCALAR(cowFilename);
 415     save(CheckpointIn::dir() + "/" + cowFilename);
 416 }
 417
 418 void
 419 CowDiskImage::unserialize(CheckpointIn &cp)
 420 {
 421     string cowFilename;
 422     UNSERIALIZE_SCALAR(cowFilename);
 423     cowFilename = cp.cptDir + "/" + cowFilename;
 424     open(cowFilename);
 425 }
 426
 427 CowDiskImage *
 428 CowDiskImageParams::create()
 429 {
 430     return new CowDiskImage(this);
 431 }