Intravision/reactos
1
0
Fork 0
mirror of https://github.com/reactos/reactos.git synced 2025-08-06 07:52:56 +00:00
Code Issues Projects Releases Packages Wiki Activity

Feng Yuning <fengyuning1984@gmail.com>:

Browse source 
- Fix ntfs reading problem (occurs when trying to load Windows from an NTFS partition, reading always failed).

svn path=/trunk/; revision=28364
This commit is contained in:
Aleksey Bragin 2007-08-15 20:04:50 +00:00
parent 85c976b666
commit 0364357251
1 changed files with 75 additions and 46 deletions
Download patch file Download diff file Expand all files Collapse all files

121
reactos/boot/freeldr/freeldr/fs/ntfs.c
View file

@ -176,7 +176,7 @@ static ULONGLONG NtfsReadAttribute(PNTFS_ATTR_CONTEXT Context, ULONGLONG Offset,
ULONGLONG CurrentOffset; ULONGLONG CurrentOffset;
ULONGLONG ReadLength; ULONGLONG ReadLength;
ULONGLONG AlreadyRead; ULONGLONG AlreadyRead;
if (!Context->Record.IsNonResident) if (!Context->Record.IsNonResident)
{ {
if (Offset > Context->Record.Resident.ValueLength) if (Offset > Context->Record.Resident.ValueLength)
@ -186,16 +186,18 @@ static ULONGLONG NtfsReadAttribute(PNTFS_ATTR_CONTEXT Context, ULONGLONG Offset,
RtlCopyMemory(Buffer, (PCHAR)&Context->Record + Context->Record.Resident.ValueOffset + Offset, Length); RtlCopyMemory(Buffer, (PCHAR)&Context->Record + Context->Record.Resident.ValueOffset + Offset, Length);
return Length; return Length;
} }
/* /*
* Non-resident attribute * Non-resident attribute
*/ */
/* /*
* I. Find the corresponding start data run. * I. Find the corresponding start data run.
*/ */
if (Context->CacheRunOffset == Offset) AlreadyRead = 0;
if(Context->CacheRunOffset <= Offset && Offset < Context->CacheRunOffset + Context->CacheRunLength * NtfsClusterSize)
{ {
DataRun = Context->CacheRun; DataRun = Context->CacheRun;
LastLCN = Context->CacheRunLastLCN; LastLCN = Context->CacheRunLastLCN;
@ -208,7 +210,7 @@ static ULONGLONG NtfsReadAttribute(PNTFS_ATTR_CONTEXT Context, ULONGLONG Offset,
LastLCN = 0; LastLCN = 0;
DataRun = (PUCHAR)&Context->Record + Context->Record.NonResident.MappingPairsOffset; DataRun = (PUCHAR)&Context->Record + Context->Record.NonResident.MappingPairsOffset;
CurrentOffset = 0; CurrentOffset = 0;
while (1) while (1)
{ {
DataRun = NtfsDecodeRun(DataRun, &DataRunOffset, &DataRunLength); DataRun = NtfsDecodeRun(DataRun, &DataRunOffset, &DataRunLength);
@ -223,70 +225,97 @@ static ULONGLONG NtfsReadAttribute(PNTFS_ATTR_CONTEXT Context, ULONGLONG Offset,
/* Sparse data run. */ /* Sparse data run. */
DataRunStartLCN = -1; DataRunStartLCN = -1;
} }
if (Offset >= CurrentOffset && if (Offset >= CurrentOffset &&
Offset < CurrentOffset + (DataRunLength * NtfsClusterSize)) Offset < CurrentOffset + (DataRunLength * NtfsClusterSize))
{ {
break; break;
} }
if (*DataRun == 0) if (*DataRun == 0)
{ {
return 0; return AlreadyRead;
} }
CurrentOffset += DataRunLength * NtfsClusterSize; CurrentOffset += DataRunLength * NtfsClusterSize;
} }
} }
/* /*
* II. Go through the run list and read the data * II. Go through the run list and read the data
*/ */
AlreadyRead = 0; ReadLength = min(DataRunLength * NtfsClusterSize - (Offset - CurrentOffset), Length);
while (Length > 0) if (DataRunStartLCN == -1)
RtlZeroMemory(Buffer, ReadLength);
if (NtfsDiskRead(DataRunStartLCN * NtfsClusterSize + Offset - CurrentOffset, ReadLength, Buffer))
{ {
ReadLength = min(DataRunLength * NtfsClusterSize, Length); Length -= ReadLength;
if (DataRunStartLCN == -1) Buffer += ReadLength;
RtlZeroMemory(Buffer, ReadLength); AlreadyRead += ReadLength;
else if (!NtfsDiskRead(DataRunStartLCN * NtfsClusterSize + Offset - CurrentOffset, ReadLength, Buffer))
break; if (ReadLength == DataRunLength * NtfsClusterSize - (Offset - CurrentOffset))
Length -= ReadLength;
Buffer += ReadLength;
AlreadyRead += ReadLength;
/* We finished this request, but there still data in this data run. */
if (Length == 0 && ReadLength != DataRunLength * NtfsClusterSize)
break;
/*
* Go to next run in the list.
*/
if (*DataRun == 0)
break;
DataRun = NtfsDecodeRun(DataRun, &DataRunOffset, &DataRunLength);
if (DataRunOffset != -1)
{ {
/* Normal data run. */ CurrentOffset += DataRunLength * NtfsClusterSize;
DataRunStartLCN = LastLCN + DataRunOffset; DataRun = NtfsDecodeRun(DataRun, &DataRunOffset, &DataRunLength);
LastLCN = DataRunStartLCN; if (DataRunLength != -1)
{
DataRunStartLCN = LastLCN + DataRunOffset;
LastLCN = DataRunStartLCN;
}
else
DataRunStartLCN = -1;
if (*DataRun == 0)
return AlreadyRead;
} }
else
while (Length > 0)
{ {
/* Sparse data run. */ ReadLength = min(DataRunLength * NtfsClusterSize, Length);
DataRunStartLCN = -1; if (DataRunStartLCN == -1)
} RtlZeroMemory(Buffer, ReadLength);
CurrentOffset += DataRunLength * NtfsClusterSize; else if (!NtfsDiskRead(DataRunStartLCN * NtfsClusterSize, ReadLength, Buffer))
} break;
Length -= ReadLength;
Buffer += ReadLength;
AlreadyRead += ReadLength;
/* We finished this request, but there still data in this data run. */
if (Length == 0 && ReadLength != DataRunLength * NtfsClusterSize)
break;
/*
* Go to next run in the list.
*/
if (*DataRun == 0)
break;
CurrentOffset += DataRunLength * NtfsClusterSize;
DataRun = NtfsDecodeRun(DataRun, &DataRunOffset, &DataRunLength);
if (DataRunOffset != -1)
{
/* Normal data run. */
DataRunStartLCN = LastLCN + DataRunOffset;
LastLCN = DataRunStartLCN;
}
else
{
/* Sparse data run. */
DataRunStartLCN = -1;
}
} /* while */
} /* if Disk */
Context->CacheRun = DataRun; Context->CacheRun = DataRun;
Context->CacheRunOffset = Offset + AlreadyRead; Context->CacheRunOffset = Offset + AlreadyRead;
Context->CacheRunStartLCN = DataRunStartLCN; Context->CacheRunStartLCN = DataRunStartLCN;
Context->CacheRunLength = DataRunLength; Context->CacheRunLength = DataRunLength;
Context->CacheRunLastLCN = LastLCN; Context->CacheRunLastLCN = LastLCN;
Context->CacheRunCurrentOffset = CurrentOffset; Context->CacheRunCurrentOffset = CurrentOffset;
return AlreadyRead; return AlreadyRead;
} }