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