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reactos/drivers/filesystems/fastfat/fcb.c
Hermès Bélusca-Maïto b77824a375 [FASTFAT] Improvements for volume dismount + minor bugfixing. 
- Cache the RootFcb so that its cleanup can be handled separately
  during dismounting.

- Force volume dismount at cleanup if the VCB_DISMOUNT_PENDING flag
  is set.

- Actually dismount a volume if its VCB has been flagged as not good,
  or if we force dismounting.

NOTE: In their *CheckForDismount() function, our 3rd-party FS drivers
as well as MS' fastfat, perform a comparison check of the current VCB's
VPB ReferenceCount with some sort of "dangling"/"residual" open count.
It seems to be related to the fact that the volume root directory as
well as auxiliary data stream(s) are still opened, and only these are
allowed to be opened at that moment. After analysis it appears that for
the ReactOS' fastfat, this number is equal to "3".

- On dismounting, cleanup and destroy the RootFcb, VolumeFcb and the
  FATFileObject. Then cleanup the SpareVPB or the IoVPB members, and
  finish by removing the dismounted volume from the VolumeListEntry
  and cleaning up the notify synchronization object and the resources.

- During dismounting, and on shutdown, flush the volume before
  resetting its dirty bit.

- On shutdown, after volume flushing, try to unmount it without forcing.

- Release the VCB resources only when we actually dismount the volume
  in VfatCheckForDismount().

- Initialize first the notify list and the synchronization object,
  before sending the FSRTL_VOLUME_MOUNT notification.

- If we failed at mounting a volume but its VCB's FATFileObject was
  already initialized, first call CcUninitializeCacheMap() on it
  before dereferencing it.

- Send FSRTL_VOLUME_LOCK, FSRTL_VOLUME_LOCK_FAILED and
  FSRTL_VOLUME_UNLOCK notifications during volume locking (and failure)
  and volume unlocking.

- Flush the volume before locking it, and clean its dirty bit if needed.

NOTE: In addition to checking for VCB_CLEAR_DIRTY, we also check for the
presence of the VCB_IS_DIRTY flag before cleaning up the dirty bit: this
allows us to not re-clean the bit if it has been previously cleaned.
This is needed for instance in this scenario:
- The volume is locked (it gets flushed and the dirty bit is possibly cleared);
- The volume then gets formatted with a completely different FS, that
  possibly clears up the first sector (e.g. BTRFS ignores 1st sector);
- The volume is then dismounted: if we didn't check whether VCB_IS_DIRTY
  was set prior to resetting it, we could attempt clearing it again! But
  now that the volume's filesystem has been completely changed, we would
  then try to modify the dirty bit on an erroneous position on disk!
  That's why it should not be touched in this case during dismounting.
- The volume is unlocked (same comment as above), and later can be
  detected as being BTRFS.
2018-11-25 09:00:40 +01:00

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/*
* FILE: drivers/filesystems/fastfat/fcb.c
* PURPOSE: Routines to manipulate FCBs.
* COPYRIGHT: See COPYING in the top level directory
* PROJECT: ReactOS kernel
* PROGRAMMER: Jason Filby (jasonfilby@yahoo.com)
* Rex Jolliff (rex@lvcablemodem.com)
* Herve Poussineau (reactos@poussine.freesurf.fr)
* Pierre Schweitzer (pierre@reactos.org)
*/
/* ------------------------------------------------------- INCLUDES */
#include "vfat.h"
#define NDEBUG
#include <debug.h>
#ifdef __GNUC__
#include <wctype.h> /* towlower prototype */
#endif
/* -------------------------------------------------------- DEFINES */
#ifdef KDBG
extern UNICODE_STRING DebugFile;
#endif
/* -------------------------------------------------------- PUBLICS */
static
ULONG
vfatNameHash(
ULONG hash,
PUNICODE_STRING NameU)
{
PWCHAR last;
PWCHAR curr;
register WCHAR c;
// LFN could start from "."
//ASSERT(NameU->Buffer[0] != L'.');
curr = NameU->Buffer;
last = NameU->Buffer + NameU->Length / sizeof(WCHAR);
while(curr < last)
{
c = towlower(*curr++);
hash = (hash + (c << 4) + (c >> 4)) * 11;
}
return hash;
}
VOID
vfatSplitPathName(
PUNICODE_STRING PathNameU,
PUNICODE_STRING DirNameU,
PUNICODE_STRING FileNameU)
{
PWCHAR pName;
USHORT Length = 0;
pName = PathNameU->Buffer + PathNameU->Length / sizeof(WCHAR) - 1;
while (*pName != L'\\' && pName >= PathNameU->Buffer)
{
pName--;
Length++;
}
ASSERT(*pName == L'\\' || pName < PathNameU->Buffer);
if (FileNameU)
{
FileNameU->Buffer = pName + 1;
FileNameU->Length = FileNameU->MaximumLength = Length * sizeof(WCHAR);
}
if (DirNameU)
{
DirNameU->Buffer = PathNameU->Buffer;
DirNameU->Length = (pName + 1 - PathNameU->Buffer) * sizeof(WCHAR);
DirNameU->MaximumLength = DirNameU->Length;
}
}
static
VOID
vfatInitFcb(
PVFATFCB Fcb,
PUNICODE_STRING NameU)
{
USHORT PathNameBufferLength;
if (NameU)
PathNameBufferLength = NameU->Length + sizeof(WCHAR);
else
PathNameBufferLength = 0;
Fcb->PathNameBuffer = ExAllocatePoolWithTag(NonPagedPool, PathNameBufferLength, TAG_FCB);
if (!Fcb->PathNameBuffer)
{
/* FIXME: what to do if no more memory? */
DPRINT1("Unable to initialize FCB for filename '%wZ'\n", NameU);
KeBugCheckEx(FAT_FILE_SYSTEM, (ULONG_PTR)Fcb, (ULONG_PTR)NameU, 0, 0);
}
Fcb->RFCB.NodeTypeCode = NODE_TYPE_FCB;
Fcb->RFCB.NodeByteSize = sizeof(VFATFCB);
Fcb->PathNameU.Length = 0;
Fcb->PathNameU.Buffer = Fcb->PathNameBuffer;
Fcb->PathNameU.MaximumLength = PathNameBufferLength;
Fcb->ShortNameU.Length = 0;
Fcb->ShortNameU.Buffer = Fcb->ShortNameBuffer;
Fcb->ShortNameU.MaximumLength = sizeof(Fcb->ShortNameBuffer);
Fcb->DirNameU.Buffer = Fcb->PathNameU.Buffer;
if (NameU && NameU->Length)
{
RtlCopyUnicodeString(&Fcb->PathNameU, NameU);
vfatSplitPathName(&Fcb->PathNameU, &Fcb->DirNameU, &Fcb->LongNameU);
}
else
{
Fcb->DirNameU.Buffer = Fcb->LongNameU.Buffer = NULL;
Fcb->DirNameU.MaximumLength = Fcb->DirNameU.Length = 0;
Fcb->LongNameU.MaximumLength = Fcb->LongNameU.Length = 0;
}
RtlZeroMemory(&Fcb->FCBShareAccess, sizeof(SHARE_ACCESS));
Fcb->OpenHandleCount = 0;
}
PVFATFCB
vfatNewFCB(
PDEVICE_EXTENSION pVCB,
PUNICODE_STRING pFileNameU)
{
PVFATFCB rcFCB;
DPRINT("'%wZ'\n", pFileNameU);
rcFCB = ExAllocateFromNPagedLookasideList(&VfatGlobalData->FcbLookasideList);
if (rcFCB == NULL)
{
return NULL;
}
RtlZeroMemory(rcFCB, sizeof(VFATFCB));
vfatInitFcb(rcFCB, pFileNameU);
if (vfatVolumeIsFatX(pVCB))
rcFCB->Attributes = &rcFCB->entry.FatX.Attrib;
else
rcFCB->Attributes = &rcFCB->entry.Fat.Attrib;
rcFCB->Hash.Hash = vfatNameHash(0, &rcFCB->PathNameU);
rcFCB->Hash.self = rcFCB;
rcFCB->ShortHash.self = rcFCB;
ExInitializeResourceLite(&rcFCB->PagingIoResource);
ExInitializeResourceLite(&rcFCB->MainResource);
FsRtlInitializeFileLock(&rcFCB->FileLock, NULL, NULL);
ExInitializeFastMutex(&rcFCB->LastMutex);
rcFCB->RFCB.PagingIoResource = &rcFCB->PagingIoResource;
rcFCB->RFCB.Resource = &rcFCB->MainResource;
rcFCB->RFCB.IsFastIoPossible = FastIoIsNotPossible;
InitializeListHead(&rcFCB->ParentListHead);
return rcFCB;
}
static
VOID
vfatDelFCBFromTable(
PDEVICE_EXTENSION pVCB,
PVFATFCB pFCB)
{
ULONG Index;
ULONG ShortIndex;
HASHENTRY* entry;
Index = pFCB->Hash.Hash % pVCB->HashTableSize;
ShortIndex = pFCB->ShortHash.Hash % pVCB->HashTableSize;
if (pFCB->Hash.Hash != pFCB->ShortHash.Hash)
{
entry = pVCB->FcbHashTable[ShortIndex];
if (entry->self == pFCB)
{
pVCB->FcbHashTable[ShortIndex] = entry->next;
}
else
{
while (entry->next->self != pFCB)
{
entry = entry->next;
}
entry->next = pFCB->ShortHash.next;
}
}
entry = pVCB->FcbHashTable[Index];
if (entry->self == pFCB)
{
pVCB->FcbHashTable[Index] = entry->next;
}
else
{
while (entry->next->self != pFCB)
{
entry = entry->next;
}
entry->next = pFCB->Hash.next;
}
RemoveEntryList(&pFCB->FcbListEntry);
}
static
NTSTATUS
vfatMakeFullName(
PVFATFCB directoryFCB,
PUNICODE_STRING LongNameU,
PUNICODE_STRING ShortNameU,
PUNICODE_STRING NameU)
{
PWCHAR PathNameBuffer;
USHORT PathNameLength;
PathNameLength = directoryFCB->PathNameU.Length + max(LongNameU->Length, ShortNameU->Length);
if (!vfatFCBIsRoot(directoryFCB))
{
PathNameLength += sizeof(WCHAR);
}
if (PathNameLength > LONGNAME_MAX_LENGTH * sizeof(WCHAR))
{
return STATUS_OBJECT_NAME_INVALID;
}
PathNameBuffer = ExAllocatePoolWithTag(NonPagedPool, PathNameLength + sizeof(WCHAR), TAG_FCB);
if (!PathNameBuffer)
{
return STATUS_INSUFFICIENT_RESOURCES;
}
NameU->Buffer = PathNameBuffer;
NameU->Length = 0;
NameU->MaximumLength = PathNameLength;
RtlCopyUnicodeString(NameU, &directoryFCB->PathNameU);
if (!vfatFCBIsRoot(directoryFCB))
{
RtlAppendUnicodeToString(NameU, L"\\");
}
if (LongNameU->Length > 0)
{
RtlAppendUnicodeStringToString(NameU, LongNameU);
}
else
{
RtlAppendUnicodeStringToString(NameU, ShortNameU);
}
NameU->Buffer[NameU->Length / sizeof(WCHAR)] = 0;
return STATUS_SUCCESS;
}
VOID
vfatDestroyCCB(
PVFATCCB pCcb)
{
if (pCcb->SearchPattern.Buffer)
{
ExFreePoolWithTag(pCcb->SearchPattern.Buffer, TAG_SEARCH);
}
ExFreeToNPagedLookasideList(&VfatGlobalData->CcbLookasideList, pCcb);
}
VOID
vfatDestroyFCB(
PVFATFCB pFCB)
{
#ifdef KDBG
if (DebugFile.Buffer != NULL && FsRtlIsNameInExpression(&DebugFile, &pFCB->LongNameU, FALSE, NULL))
{
DPRINT1("Destroying: %p (%wZ) %d\n", pFCB, &pFCB->PathNameU, pFCB->RefCount);
}
#endif
FsRtlUninitializeFileLock(&pFCB->FileLock);
if (!vfatFCBIsRoot(pFCB) &&
!BooleanFlagOn(pFCB->Flags, FCB_IS_FAT) && !BooleanFlagOn(pFCB->Flags, FCB_IS_VOLUME))
{
RemoveEntryList(&pFCB->ParentListEntry);
}
ExFreePool(pFCB->PathNameBuffer);
ExDeleteResourceLite(&pFCB->PagingIoResource);
ExDeleteResourceLite(&pFCB->MainResource);
ASSERT(IsListEmpty(&pFCB->ParentListHead));
ExFreeToNPagedLookasideList(&VfatGlobalData->FcbLookasideList, pFCB);
}
BOOLEAN
vfatFCBIsRoot(
PVFATFCB FCB)
{
return FCB->PathNameU.Length == sizeof(WCHAR) && FCB->PathNameU.Buffer[0] == L'\\' ? TRUE : FALSE;
}
VOID
#ifndef KDBG
vfatGrabFCB(
#else
_vfatGrabFCB(
#endif
PDEVICE_EXTENSION pVCB,
PVFATFCB pFCB
#ifdef KDBG
,
PCSTR File,
ULONG Line,
PCSTR Func
#endif
)
{
#ifdef KDBG
if (DebugFile.Buffer != NULL && FsRtlIsNameInExpression(&DebugFile, &pFCB->LongNameU, FALSE, NULL))
{
DPRINT1("Inc ref count (%d, oc: %d) for: %p (%wZ) at: %s(%d) %s\n", pFCB->RefCount, pFCB->OpenHandleCount, pFCB, &pFCB->PathNameU, File, Line, Func);
}
#else
DPRINT("Grabbing FCB at %p: %wZ, refCount:%d\n",
pFCB, &pFCB->PathNameU, pFCB->RefCount);
#endif
ASSERT(ExIsResourceAcquiredExclusive(&pVCB->DirResource));
ASSERT(!BooleanFlagOn(pFCB->Flags, FCB_IS_FAT));
ASSERT(pFCB != pVCB->VolumeFcb && !BooleanFlagOn(pFCB->Flags, FCB_IS_VOLUME));
ASSERT(pFCB->RefCount > 0);
++pFCB->RefCount;
}
VOID
#ifndef KDBG
vfatReleaseFCB(
#else
_vfatReleaseFCB(
#endif
PDEVICE_EXTENSION pVCB,
PVFATFCB pFCB
#ifdef KDBG
,
PCSTR File,
ULONG Line,
PCSTR Func
#endif
)
{
PVFATFCB tmpFcb;
#ifdef KDBG
if (DebugFile.Buffer != NULL && FsRtlIsNameInExpression(&DebugFile, &pFCB->LongNameU, FALSE, NULL))
{
DPRINT1("Dec ref count (%d, oc: %d) for: %p (%wZ) at: %s(%d) %s\n", pFCB->RefCount, pFCB->OpenHandleCount, pFCB, &pFCB->PathNameU, File, Line, Func);
}
#else
DPRINT("Releasing FCB at %p: %wZ, refCount:%d\n",
pFCB, &pFCB->PathNameU, pFCB->RefCount);
#endif
ASSERT(ExIsResourceAcquiredExclusive(&pVCB->DirResource));
while (pFCB)
{
ULONG RefCount;
ASSERT(!BooleanFlagOn(pFCB->Flags, FCB_IS_FAT));
ASSERT(pFCB != pVCB->VolumeFcb && !BooleanFlagOn(pFCB->Flags, FCB_IS_VOLUME));
ASSERT(pFCB->RefCount > 0);
RefCount = --pFCB->RefCount;
if (RefCount == 1 && BooleanFlagOn(pFCB->Flags, FCB_CACHE_INITIALIZED))
{
PFILE_OBJECT tmpFileObject;
tmpFileObject = pFCB->FileObject;
pFCB->FileObject = NULL;
CcUninitializeCacheMap(tmpFileObject, NULL, NULL);
ClearFlag(pFCB->Flags, FCB_CACHE_INITIALIZED);
ObDereferenceObject(tmpFileObject);
}
if (RefCount == 0)
{
ASSERT(pFCB->OpenHandleCount == 0);
tmpFcb = pFCB->parentFcb;
vfatDelFCBFromTable(pVCB, pFCB);
vfatDestroyFCB(pFCB);
}
else
{
tmpFcb = NULL;
}
pFCB = tmpFcb;
}
}
static
VOID
vfatAddFCBToTable(
PDEVICE_EXTENSION pVCB,
PVFATFCB pFCB)
{
ULONG Index;
ULONG ShortIndex;
ASSERT(pFCB->Hash.Hash == vfatNameHash(0, &pFCB->PathNameU));
Index = pFCB->Hash.Hash % pVCB->HashTableSize;
ShortIndex = pFCB->ShortHash.Hash % pVCB->HashTableSize;
InsertTailList(&pVCB->FcbListHead, &pFCB->FcbListEntry);
pFCB->Hash.next = pVCB->FcbHashTable[Index];
pVCB->FcbHashTable[Index] = &pFCB->Hash;
if (pFCB->Hash.Hash != pFCB->ShortHash.Hash)
{
pFCB->ShortHash.next = pVCB->FcbHashTable[ShortIndex];
pVCB->FcbHashTable[ShortIndex] = &pFCB->ShortHash;
}
if (pFCB->parentFcb)
{
vfatGrabFCB(pVCB, pFCB->parentFcb);
}
}
static
VOID
vfatInitFCBFromDirEntry(
PDEVICE_EXTENSION Vcb,
PVFATFCB Fcb,
PVFAT_DIRENTRY_CONTEXT DirContext)
{
ULONG Size;
RtlCopyMemory(&Fcb->entry, &DirContext->DirEntry, sizeof (DIR_ENTRY));
RtlCopyUnicodeString(&Fcb->ShortNameU, &DirContext->ShortNameU);
Fcb->Hash.Hash = vfatNameHash(0, &Fcb->PathNameU);
if (vfatVolumeIsFatX(Vcb))
{
Fcb->ShortHash.Hash = Fcb->Hash.Hash;
}
else
{
Fcb->ShortHash.Hash = vfatNameHash(0, &Fcb->DirNameU);
Fcb->ShortHash.Hash = vfatNameHash(Fcb->ShortHash.Hash, &Fcb->ShortNameU);
}
if (vfatFCBIsDirectory(Fcb))
{
ULONG FirstCluster, CurrentCluster;
NTSTATUS Status = STATUS_SUCCESS;
Size = 0;
FirstCluster = vfatDirEntryGetFirstCluster(Vcb, &Fcb->entry);
if (FirstCluster == 1)
{
Size = Vcb->FatInfo.rootDirectorySectors * Vcb->FatInfo.BytesPerSector;
}
else if (FirstCluster != 0)
{
CurrentCluster = FirstCluster;
while (CurrentCluster != 0xffffffff && NT_SUCCESS(Status))
{
Size += Vcb->FatInfo.BytesPerCluster;
Status = NextCluster(Vcb, FirstCluster, &CurrentCluster, FALSE);
}
}
}
else if (vfatVolumeIsFatX(Vcb))
{
Size = Fcb->entry.FatX.FileSize;
}
else
{
Size = Fcb->entry.Fat.FileSize;
}
Fcb->dirIndex = DirContext->DirIndex;
Fcb->startIndex = DirContext->StartIndex;
if (vfatVolumeIsFatX(Vcb) && !vfatFCBIsRoot(Fcb))
{
ASSERT(DirContext->DirIndex >= 2 && DirContext->StartIndex >= 2);
Fcb->dirIndex = DirContext->DirIndex-2;
Fcb->startIndex = DirContext->StartIndex-2;
}
Fcb->RFCB.FileSize.QuadPart = Size;
Fcb->RFCB.ValidDataLength.QuadPart = Size;
Fcb->RFCB.AllocationSize.QuadPart = ROUND_UP_64(Size, Vcb->FatInfo.BytesPerCluster);
}
NTSTATUS
vfatSetFCBNewDirName(
PDEVICE_EXTENSION pVCB,
PVFATFCB Fcb,
PVFATFCB ParentFcb)
{
NTSTATUS Status;
UNICODE_STRING NewNameU;
/* Get full path name */
Status = vfatMakeFullName(ParentFcb, &Fcb->LongNameU, &Fcb->ShortNameU, &NewNameU);
if (!NT_SUCCESS(Status))
{
return Status;
}
/* Delete old name */
if (Fcb->PathNameBuffer)
{
ExFreePoolWithTag(Fcb->PathNameBuffer, TAG_FCB);
}
Fcb->PathNameU = NewNameU;
/* Delete from table */
vfatDelFCBFromTable(pVCB, Fcb);
/* Split it properly */
Fcb->PathNameBuffer = Fcb->PathNameU.Buffer;
Fcb->DirNameU.Buffer = Fcb->PathNameU.Buffer;
vfatSplitPathName(&Fcb->PathNameU, &Fcb->DirNameU, &Fcb->LongNameU);
Fcb->Hash.Hash = vfatNameHash(0, &Fcb->PathNameU);
if (vfatVolumeIsFatX(pVCB))
{
Fcb->ShortHash.Hash = Fcb->Hash.Hash;
}
else
{
Fcb->ShortHash.Hash = vfatNameHash(0, &Fcb->DirNameU);
Fcb->ShortHash.Hash = vfatNameHash(Fcb->ShortHash.Hash, &Fcb->ShortNameU);
}
vfatAddFCBToTable(pVCB, Fcb);
vfatReleaseFCB(pVCB, ParentFcb);
return STATUS_SUCCESS;
}
NTSTATUS
vfatUpdateFCB(
PDEVICE_EXTENSION pVCB,
PVFATFCB Fcb,
PVFAT_DIRENTRY_CONTEXT DirContext,
PVFATFCB ParentFcb)
{
NTSTATUS Status;
PVFATFCB OldParent;
DPRINT("vfatUpdateFCB(%p, %p, %p, %p)\n", pVCB, Fcb, DirContext, ParentFcb);
/* Get full path name */
Status = vfatMakeFullName(ParentFcb, &DirContext->LongNameU, &DirContext->ShortNameU, &Fcb->PathNameU);
if (!NT_SUCCESS(Status))
{
return Status;
}
/* Delete old name */
if (Fcb->PathNameBuffer)
{
ExFreePoolWithTag(Fcb->PathNameBuffer, TAG_FCB);
}
/* Delete from table */
vfatDelFCBFromTable(pVCB, Fcb);
/* Split it properly */
Fcb->PathNameBuffer = Fcb->PathNameU.Buffer;
Fcb->DirNameU.Buffer = Fcb->PathNameU.Buffer;
vfatSplitPathName(&Fcb->PathNameU, &Fcb->DirNameU, &Fcb->LongNameU);
/* Save old parent */
OldParent = Fcb->parentFcb;
RemoveEntryList(&Fcb->ParentListEntry);
/* Reinit FCB */
vfatInitFCBFromDirEntry(pVCB, Fcb, DirContext);
if (vfatFCBIsDirectory(Fcb))
{
CcFlushCache(&Fcb->SectionObjectPointers, NULL, 0, NULL);
}
Fcb->parentFcb = ParentFcb;
InsertTailList(&ParentFcb->ParentListHead, &Fcb->ParentListEntry);
vfatAddFCBToTable(pVCB, Fcb);
/* If we moved across directories, dereference our old parent
* We also dereference in case we're just renaming since AddFCBToTable references it
*/
vfatReleaseFCB(pVCB, OldParent);
return STATUS_SUCCESS;
}
PVFATFCB
vfatGrabFCBFromTable(
PDEVICE_EXTENSION pVCB,
PUNICODE_STRING PathNameU)
{
PVFATFCB rcFCB;
ULONG Hash;
UNICODE_STRING DirNameU;
UNICODE_STRING FileNameU;
PUNICODE_STRING FcbNameU;
HASHENTRY* entry;
DPRINT("'%wZ'\n", PathNameU);
ASSERT(PathNameU->Length >= sizeof(WCHAR) && PathNameU->Buffer[0] == L'\\');
Hash = vfatNameHash(0, PathNameU);
entry = pVCB->FcbHashTable[Hash % pVCB->HashTableSize];
if (entry)
{
vfatSplitPathName(PathNameU, &DirNameU, &FileNameU);
}
while (entry)
{
if (entry->Hash == Hash)
{
rcFCB = entry->self;
DPRINT("'%wZ' '%wZ'\n", &DirNameU, &rcFCB->DirNameU);
if (RtlEqualUnicodeString(&DirNameU, &rcFCB->DirNameU, TRUE))
{
if (rcFCB->Hash.Hash == Hash)
{
FcbNameU = &rcFCB->LongNameU;
}
else
{
FcbNameU = &rcFCB->ShortNameU;
}
/* compare the file name */
DPRINT("'%wZ' '%wZ'\n", &FileNameU, FcbNameU);
if (RtlEqualUnicodeString(&FileNameU, FcbNameU, TRUE))
{
vfatGrabFCB(pVCB, rcFCB);
return rcFCB;
}
}
}
entry = entry->next;
}
return NULL;
}
PVFATFCB
vfatMakeRootFCB(
PDEVICE_EXTENSION pVCB)
{
PVFATFCB FCB;
ULONG FirstCluster, CurrentCluster, Size = 0;
NTSTATUS Status = STATUS_SUCCESS;
UNICODE_STRING NameU = RTL_CONSTANT_STRING(L"\\");
ASSERT(pVCB->RootFcb == NULL);
FCB = vfatNewFCB(pVCB, &NameU);
if (vfatVolumeIsFatX(pVCB))
{
memset(FCB->entry.FatX.Filename, ' ', 42);
FCB->entry.FatX.FileSize = pVCB->FatInfo.rootDirectorySectors * pVCB->FatInfo.BytesPerSector;
FCB->entry.FatX.Attrib = FILE_ATTRIBUTE_DIRECTORY;
FCB->entry.FatX.FirstCluster = 1;
Size = pVCB->FatInfo.rootDirectorySectors * pVCB->FatInfo.BytesPerSector;
}
else
{
memset(FCB->entry.Fat.ShortName, ' ', 11);
FCB->entry.Fat.FileSize = pVCB->FatInfo.rootDirectorySectors * pVCB->FatInfo.BytesPerSector;
FCB->entry.Fat.Attrib = FILE_ATTRIBUTE_DIRECTORY;
if (pVCB->FatInfo.FatType == FAT32)
{
CurrentCluster = FirstCluster = pVCB->FatInfo.RootCluster;
FCB->entry.Fat.FirstCluster = (unsigned short)(FirstCluster & 0xffff);
FCB->entry.Fat.FirstClusterHigh = (unsigned short)(FirstCluster >> 16);
while (CurrentCluster != 0xffffffff && NT_SUCCESS(Status))
{
Size += pVCB->FatInfo.BytesPerCluster;
Status = NextCluster (pVCB, FirstCluster, &CurrentCluster, FALSE);
}
}
else
{
FCB->entry.Fat.FirstCluster = 1;
Size = pVCB->FatInfo.rootDirectorySectors * pVCB->FatInfo.BytesPerSector;
}
}
FCB->ShortHash.Hash = FCB->Hash.Hash;
FCB->RefCount = 2;
FCB->dirIndex = 0;
FCB->RFCB.FileSize.QuadPart = Size;
FCB->RFCB.ValidDataLength.QuadPart = Size;
FCB->RFCB.AllocationSize.QuadPart = Size;
FCB->RFCB.IsFastIoPossible = FastIoIsNotPossible;
vfatFCBInitializeCacheFromVolume(pVCB, FCB);
vfatAddFCBToTable(pVCB, FCB);
/* Cache it */
pVCB->RootFcb = FCB;
return FCB;
}
PVFATFCB
vfatOpenRootFCB(
PDEVICE_EXTENSION pVCB)
{
PVFATFCB FCB;
UNICODE_STRING NameU = RTL_CONSTANT_STRING(L"\\");
FCB = vfatGrabFCBFromTable(pVCB, &NameU);
if (FCB == NULL)
{
FCB = vfatMakeRootFCB(pVCB);
}
ASSERT(FCB == pVCB->RootFcb);
return FCB;
}
NTSTATUS
vfatMakeFCBFromDirEntry(
PVCB vcb,
PVFATFCB directoryFCB,
PVFAT_DIRENTRY_CONTEXT DirContext,
PVFATFCB *fileFCB)
{
PVFATFCB rcFCB;
UNICODE_STRING NameU;
NTSTATUS Status;
Status = vfatMakeFullName(directoryFCB, &DirContext->LongNameU, &DirContext->ShortNameU, &NameU);
if (!NT_SUCCESS(Status))
{
return Status;
}
rcFCB = vfatNewFCB(vcb, &NameU);
vfatInitFCBFromDirEntry(vcb, rcFCB, DirContext);
rcFCB->RefCount = 1;
rcFCB->parentFcb = directoryFCB;
InsertTailList(&directoryFCB->ParentListHead, &rcFCB->ParentListEntry);
vfatAddFCBToTable(vcb, rcFCB);
*fileFCB = rcFCB;
ExFreePoolWithTag(NameU.Buffer, TAG_FCB);
return STATUS_SUCCESS;
}
NTSTATUS
vfatAttachFCBToFileObject(
PDEVICE_EXTENSION vcb,
PVFATFCB fcb,
PFILE_OBJECT fileObject)
{
PVFATCCB newCCB;
#ifdef KDBG
if (DebugFile.Buffer != NULL && FsRtlIsNameInExpression(&DebugFile, &fcb->LongNameU, FALSE, NULL))
{
DPRINT1("Attaching %p to %p (%d)\n", fcb, fileObject, fcb->RefCount);
}
#endif
newCCB = ExAllocateFromNPagedLookasideList(&VfatGlobalData->CcbLookasideList);
if (newCCB == NULL)
{
return STATUS_INSUFFICIENT_RESOURCES;
}
RtlZeroMemory(newCCB, sizeof (VFATCCB));
fileObject->SectionObjectPointer = &fcb->SectionObjectPointers;
fileObject->FsContext = fcb;
fileObject->FsContext2 = newCCB;
fileObject->Vpb = vcb->IoVPB;
DPRINT("file open: fcb:%p PathName:%wZ\n", fcb, &fcb->PathNameU);
#ifdef KDBG
fcb->Flags &= ~FCB_CLEANED_UP;
fcb->Flags &= ~FCB_CLOSED;
#endif
return STATUS_SUCCESS;
}
NTSTATUS
vfatDirFindFile(
PDEVICE_EXTENSION pDeviceExt,
PVFATFCB pDirectoryFCB,
PUNICODE_STRING FileToFindU,
PVFATFCB *pFoundFCB)
{
NTSTATUS status;
PVOID Context = NULL;
PVOID Page = NULL;
BOOLEAN First = TRUE;
VFAT_DIRENTRY_CONTEXT DirContext;
/* This buffer must have a size of 260 characters, because
vfatMakeFCBFromDirEntry can copy 20 name entries with 13 characters. */
WCHAR LongNameBuffer[260];
WCHAR ShortNameBuffer[13];
BOOLEAN FoundLong = FALSE;
BOOLEAN FoundShort = FALSE;
BOOLEAN IsFatX = vfatVolumeIsFatX(pDeviceExt);
ASSERT(pDeviceExt);
ASSERT(pDirectoryFCB);
ASSERT(FileToFindU);
DPRINT("vfatDirFindFile(VCB:%p, dirFCB:%p, File:%wZ)\n",
pDeviceExt, pDirectoryFCB, FileToFindU);
DPRINT("Dir Path:%wZ\n", &pDirectoryFCB->PathNameU);
DirContext.DirIndex = 0;
DirContext.LongNameU.Buffer = LongNameBuffer;
DirContext.LongNameU.Length = 0;
DirContext.LongNameU.MaximumLength = sizeof(LongNameBuffer);
DirContext.ShortNameU.Buffer = ShortNameBuffer;
DirContext.ShortNameU.Length = 0;
DirContext.ShortNameU.MaximumLength = sizeof(ShortNameBuffer);
DirContext.DeviceExt = pDeviceExt;
while (TRUE)
{
status = VfatGetNextDirEntry(pDeviceExt,
&Context,
&Page,
pDirectoryFCB,
&DirContext,
First);
First = FALSE;
if (status == STATUS_NO_MORE_ENTRIES)
{
return STATUS_OBJECT_NAME_NOT_FOUND;
}
if (!NT_SUCCESS(status))
{
return status;
}
DPRINT(" Index:%u longName:%wZ\n",
DirContext.DirIndex, &DirContext.LongNameU);
if (!ENTRY_VOLUME(IsFatX, &DirContext.DirEntry))
{
if (DirContext.LongNameU.Length == 0 ||
DirContext.ShortNameU.Length == 0)
{
DPRINT1("WARNING: File system corruption detected. You may need to run a disk repair utility.\n");
if (VfatGlobalData->Flags & VFAT_BREAK_ON_CORRUPTION)
{
ASSERT(DirContext.LongNameU.Length != 0 &&
DirContext.ShortNameU.Length != 0);
}
DirContext.DirIndex++;
continue;
}
FoundLong = RtlEqualUnicodeString(FileToFindU, &DirContext.LongNameU, TRUE);
if (FoundLong == FALSE)
{
FoundShort = RtlEqualUnicodeString(FileToFindU, &DirContext.ShortNameU, TRUE);
}
if (FoundLong || FoundShort)
{
status = vfatMakeFCBFromDirEntry(pDeviceExt,
pDirectoryFCB,
&DirContext,
pFoundFCB);
CcUnpinData(Context);
return status;
}
}
DirContext.DirIndex++;
}
return STATUS_OBJECT_NAME_NOT_FOUND;
}
NTSTATUS
vfatGetFCBForFile(
PDEVICE_EXTENSION pVCB,
PVFATFCB *pParentFCB,
PVFATFCB *pFCB,
PUNICODE_STRING pFileNameU)
{
NTSTATUS status;
PVFATFCB FCB = NULL;
PVFATFCB parentFCB;
UNICODE_STRING NameU;
UNICODE_STRING RootNameU = RTL_CONSTANT_STRING(L"\\");
UNICODE_STRING FileNameU;
WCHAR NameBuffer[260];
PWCHAR curr, prev, last;
ULONG Length;
DPRINT("vfatGetFCBForFile (%p,%p,%p,%wZ)\n",
pVCB, pParentFCB, pFCB, pFileNameU);
RtlInitEmptyUnicodeString(&FileNameU, NameBuffer, sizeof(NameBuffer));
parentFCB = *pParentFCB;
if (parentFCB == NULL)
{
/* Passed-in name is the full name */
RtlCopyUnicodeString(&FileNameU, pFileNameU);
// Trivial case, open of the root directory on volume
if (RtlEqualUnicodeString(&FileNameU, &RootNameU, FALSE))
{
DPRINT("returning root FCB\n");
FCB = vfatOpenRootFCB(pVCB);
*pFCB = FCB;
*pParentFCB = NULL;
return (FCB != NULL) ? STATUS_SUCCESS : STATUS_OBJECT_PATH_NOT_FOUND;
}
/* Check for an existing FCB */
FCB = vfatGrabFCBFromTable(pVCB, &FileNameU);
if (FCB)
{
*pFCB = FCB;
*pParentFCB = FCB->parentFcb;
vfatGrabFCB(pVCB, *pParentFCB);
return STATUS_SUCCESS;
}
last = curr = FileNameU.Buffer + FileNameU.Length / sizeof(WCHAR) - 1;
while (*curr != L'\\' && curr > FileNameU.Buffer)
{
curr--;
}
if (curr > FileNameU.Buffer)
{
NameU.Buffer = FileNameU.Buffer;
NameU.MaximumLength = NameU.Length = (curr - FileNameU.Buffer) * sizeof(WCHAR);
FCB = vfatGrabFCBFromTable(pVCB, &NameU);
if (FCB)
{
Length = (curr - FileNameU.Buffer) * sizeof(WCHAR);
if (Length != FCB->PathNameU.Length)
{
if (FileNameU.Length + FCB->PathNameU.Length - Length > FileNameU.MaximumLength)
{
vfatReleaseFCB(pVCB, FCB);
return STATUS_OBJECT_NAME_INVALID;
}
RtlMoveMemory(FileNameU.Buffer + FCB->PathNameU.Length / sizeof(WCHAR),
curr, FileNameU.Length - Length);
FileNameU.Length += (USHORT)(FCB->PathNameU.Length - Length);
curr = FileNameU.Buffer + FCB->PathNameU.Length / sizeof(WCHAR);
last = FileNameU.Buffer + FileNameU.Length / sizeof(WCHAR) - 1;
}
RtlCopyMemory(FileNameU.Buffer, FCB->PathNameU.Buffer, FCB->PathNameU.Length);
}
}
else
{
FCB = NULL;
}
if (FCB == NULL)
{
FCB = vfatOpenRootFCB(pVCB);
curr = FileNameU.Buffer;
}
parentFCB = NULL;
prev = curr;
}
else
{
/* Make absolute path */
RtlCopyUnicodeString(&FileNameU, &parentFCB->PathNameU);
curr = FileNameU.Buffer + FileNameU.Length / sizeof(WCHAR) - 1;
if (*curr != L'\\')
{
RtlAppendUnicodeToString(&FileNameU, L"\\");
curr++;
}
ASSERT(*curr == L'\\');
RtlAppendUnicodeStringToString(&FileNameU, pFileNameU);
FCB = parentFCB;
parentFCB = NULL;
prev = curr;
last = FileNameU.Buffer + FileNameU.Length / sizeof(WCHAR) - 1;
}
while (curr <= last)
{
if (parentFCB)
{
vfatReleaseFCB(pVCB, parentFCB);
parentFCB = NULL;
}
// fail if element in FCB is not a directory
if (!vfatFCBIsDirectory(FCB))
{
DPRINT ("Element in requested path is not a directory\n");
vfatReleaseFCB(pVCB, FCB);
FCB = NULL;
*pParentFCB = NULL;
*pFCB = NULL;
return STATUS_OBJECT_PATH_NOT_FOUND;
}
parentFCB = FCB;
if (prev < curr)
{
Length = (curr - prev) * sizeof(WCHAR);
if (Length != parentFCB->LongNameU.Length)
{
if (FileNameU.Length + parentFCB->LongNameU.Length - Length > FileNameU.MaximumLength)
{
vfatReleaseFCB(pVCB, parentFCB);
*pParentFCB = NULL;
*pFCB = NULL;
return STATUS_OBJECT_NAME_INVALID;
}
RtlMoveMemory(prev + parentFCB->LongNameU.Length / sizeof(WCHAR), curr,
FileNameU.Length - (curr - FileNameU.Buffer) * sizeof(WCHAR));
FileNameU.Length += (USHORT)(parentFCB->LongNameU.Length - Length);
curr = prev + parentFCB->LongNameU.Length / sizeof(WCHAR);
last = FileNameU.Buffer + FileNameU.Length / sizeof(WCHAR) - 1;
}
RtlCopyMemory(prev, parentFCB->LongNameU.Buffer, parentFCB->LongNameU.Length);
}
curr++;
prev = curr;
while (*curr != L'\\' && curr <= last)
{
curr++;
}
NameU.Buffer = FileNameU.Buffer;
NameU.Length = (curr - NameU.Buffer) * sizeof(WCHAR);
NameU.MaximumLength = FileNameU.MaximumLength;
DPRINT("%wZ\n", &NameU);
FCB = vfatGrabFCBFromTable(pVCB, &NameU);
if (FCB == NULL)
{
NameU.Buffer = prev;
NameU.MaximumLength = NameU.Length = (curr - prev) * sizeof(WCHAR);
status = vfatDirFindFile(pVCB, parentFCB, &NameU, &FCB);
if (status == STATUS_OBJECT_NAME_NOT_FOUND)
{
*pFCB = NULL;
if (curr > last)
{
*pParentFCB = parentFCB;
return STATUS_OBJECT_NAME_NOT_FOUND;
}
else
{
vfatReleaseFCB(pVCB, parentFCB);
*pParentFCB = NULL;
return STATUS_OBJECT_PATH_NOT_FOUND;
}
}
else if (!NT_SUCCESS(status))
{
vfatReleaseFCB(pVCB, parentFCB);
*pParentFCB = NULL;
*pFCB = NULL;
return status;
}
}
}
*pParentFCB = parentFCB;
*pFCB = FCB;
return STATUS_SUCCESS;
}
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