diff options
Diffstat (limited to 'apt-pkg/contrib/mmap.cc')
| -rw-r--r-- | apt-pkg/contrib/mmap.cc | 70 |
1 files changed, 59 insertions, 11 deletions
diff --git a/apt-pkg/contrib/mmap.cc b/apt-pkg/contrib/mmap.cc index f440f9489..b3f29032c 100644 --- a/apt-pkg/contrib/mmap.cc +++ b/apt-pkg/contrib/mmap.cc @@ -27,6 +27,7 @@ #include <unistd.h> #include <fcntl.h> #include <stdlib.h> +#include <errno.h> #include <cstring> /*}}}*/ @@ -35,7 +36,7 @@ // --------------------------------------------------------------------- /* */ MMap::MMap(FileFd &F,unsigned long Flags) : Flags(Flags), iSize(0), - Base(0) + Base(0), SyncToFd(NULL) { if ((Flags & NoImmMap) != NoImmMap) Map(F); @@ -45,7 +46,7 @@ MMap::MMap(FileFd &F,unsigned long Flags) : Flags(Flags), iSize(0), // --------------------------------------------------------------------- /* */ MMap::MMap(unsigned long Flags) : Flags(Flags), iSize(0), - Base(0) + Base(0), SyncToFd(NULL) { } /*}}}*/ @@ -78,7 +79,24 @@ bool MMap::Map(FileFd &Fd) // Map it. Base = mmap(0,iSize,Prot,Map,Fd.Fd(),0); if (Base == (void *)-1) - return _error->Errno("mmap",_("Couldn't make mmap of %lu bytes"),iSize); + { + if (errno == ENODEV || errno == EINVAL) + { + // The filesystem doesn't support this particular kind of mmap. + // So we allocate a buffer and read the whole file into it. + int const dupped_fd = dup(Fd.Fd()); + if (dupped_fd == -1) + return _error->Errno("mmap", _("Couldn't duplicate file descriptor %i"), Fd.Fd()); + + Base = new unsigned char[iSize]; + SyncToFd = new FileFd (dupped_fd); + if (!SyncToFd->Seek(0L) || !SyncToFd->Read(Base, iSize)) + return false; + } + else + return _error->Errno("mmap",_("Couldn't make mmap of %lu bytes"), + iSize); + } return true; } @@ -93,10 +111,19 @@ bool MMap::Close(bool DoSync) if (DoSync == true) Sync(); - - if (munmap((char *)Base,iSize) != 0) - _error->Warning("Unable to munmap"); - + + if (SyncToFd != NULL) + { + delete[] (char *)Base; + delete SyncToFd; + SyncToFd = NULL; + } + else + { + if (munmap((char *)Base, iSize) != 0) + _error->WarningE("mmap", _("Unable to close mmap")); + } + iSize = 0; Base = 0; return true; @@ -113,8 +140,18 @@ bool MMap::Sync() #ifdef _POSIX_SYNCHRONIZED_IO if ((Flags & ReadOnly) != ReadOnly) - if (msync((char *)Base,iSize,MS_SYNC) < 0) - return _error->Errno("msync","Unable to write mmap"); + { + if (SyncToFd != NULL) + { + if (!SyncToFd->Seek(0) || !SyncToFd->Write(Base, iSize)) + return false; + } + else + { + if (msync((char *)Base, iSize, MS_SYNC) < 0) + return _error->Errno("msync", _("Unable to synchronize mmap")); + } + } #endif return true; } @@ -130,8 +167,19 @@ bool MMap::Sync(unsigned long Start,unsigned long Stop) #ifdef _POSIX_SYNCHRONIZED_IO unsigned long PSize = sysconf(_SC_PAGESIZE); if ((Flags & ReadOnly) != ReadOnly) - if (msync((char *)Base+(int)(Start/PSize)*PSize,Stop - Start,MS_SYNC) < 0) - return _error->Errno("msync","Unable to write mmap"); + { + if (SyncToFd != 0) + { + if (!SyncToFd->Seek(0) || + !SyncToFd->Write (((char *)Base)+Start, Stop-Start)) + return false; + } + else + { + if (msync((char *)Base+(int)(Start/PSize)*PSize,Stop - Start,MS_SYNC) < 0) + return _error->Errno("msync", _("Unable to synchronize mmap")); + } + } #endif return true; } |