filelock.c File Reference

#include <ntoskrnl.h>
#include <debug.h>

Include dependency graph for filelock.c:

Go to the source code of this file.

Classes
union	_COMBINED_LOCK_ELEMENT
struct	_LOCK_INFORMATION
struct	_LOCK_SHARED_RANGE

Macros
#define	NDEBUG
#define	TAG_TABLE   'LTAB'
#define	TAG_RANGE   'FSRA'
#define	TAG_FLOCK   'FLCK'

Typedefs
typedef union _COMBINED_LOCK_ELEMENT	COMBINED_LOCK_ELEMENT
typedef union _COMBINED_LOCK_ELEMENT *	PCOMBINED_LOCK_ELEMENT
typedef struct _LOCK_INFORMATION	LOCK_INFORMATION
typedef struct _LOCK_INFORMATION *	PLOCK_INFORMATION
typedef struct _LOCK_SHARED_RANGE	LOCK_SHARED_RANGE
typedef struct _LOCK_SHARED_RANGE *	PLOCK_SHARED_RANGE

Functions
VOID NTAPI	FsRtlCompleteLockIrpReal (IN PCOMPLETE_LOCK_IRP_ROUTINE CompleteRoutine, IN PVOID Context, IN PIRP Irp, IN NTSTATUS Status, OUT PNTSTATUS NewStatus, IN PFILE_OBJECT FileObject OPTIONAL)
static PVOID NTAPI	LockAllocate (PRTL_GENERIC_TABLE Table, CLONG Bytes)
static VOID NTAPI	LockFree (PRTL_GENERIC_TABLE Table, PVOID Buffer)
static RTL_GENERIC_COMPARE_RESULTS NTAPI	LockCompare (PRTL_GENERIC_TABLE Table, PVOID PtrA, PVOID PtrB)
static NTSTATUS NTAPI	LockInsertIrpEx (PIO_CSQ Csq, PIRP Irp, PVOID InsertContext)
static VOID NTAPI	LockRemoveIrp (PIO_CSQ Csq, PIRP Irp)
static PIRP NTAPI	LockPeekNextIrp (PIO_CSQ Csq, PIRP Irp, PVOID PeekContext)
static VOID NTAPI	LockAcquireQueueLock (PIO_CSQ Csq, PKIRQL Irql)
static VOID NTAPI	LockReleaseQueueLock (PIO_CSQ Csq, KIRQL Irql)
static VOID NTAPI	LockCompleteCanceledIrp (PIO_CSQ Csq, PIRP Irp)
PFILE_LOCK_INFO NTAPI	FsRtlGetNextFileLock (IN PFILE_LOCK FileLock, IN BOOLEAN Restart)
VOID NTAPI	FsRtlpExpandLockElement (PCOMBINED_LOCK_ELEMENT ToExpand, PCOMBINED_LOCK_ELEMENT Conflict)
PCOMBINED_LOCK_ELEMENT NTAPI	FsRtlpRebuildSharedLockRange (PFILE_LOCK FileLock, PLOCK_INFORMATION LockInfo, PCOMBINED_LOCK_ELEMENT Conflict)
BOOLEAN NTAPI	FsRtlPrivateLock (IN PFILE_LOCK FileLock, IN PFILE_OBJECT FileObject, IN PLARGE_INTEGER FileOffset, IN PLARGE_INTEGER Length, IN PEPROCESS Process, IN ULONG Key, IN BOOLEAN FailImmediately, IN BOOLEAN ExclusiveLock, OUT PIO_STATUS_BLOCK IoStatus, IN PIRP Irp OPTIONAL, IN PVOID Context OPTIONAL, IN BOOLEAN AlreadySynchronized)
BOOLEAN NTAPI	FsRtlCheckLockForReadAccess (IN PFILE_LOCK FileLock, IN PIRP Irp)
BOOLEAN NTAPI	FsRtlCheckLockForWriteAccess (IN PFILE_LOCK FileLock, IN PIRP Irp)
BOOLEAN NTAPI	FsRtlFastCheckLockForRead (IN PFILE_LOCK FileLock, IN PLARGE_INTEGER FileOffset, IN PLARGE_INTEGER Length, IN ULONG Key, IN PFILE_OBJECT FileObject, IN PVOID Process)
BOOLEAN NTAPI	FsRtlFastCheckLockForWrite (IN PFILE_LOCK FileLock, IN PLARGE_INTEGER FileOffset, IN PLARGE_INTEGER Length, IN ULONG Key, IN PFILE_OBJECT FileObject, IN PVOID Process)
NTSTATUS NTAPI	FsRtlFastUnlockSingle (IN PFILE_LOCK FileLock, IN PFILE_OBJECT FileObject, IN PLARGE_INTEGER FileOffset, IN PLARGE_INTEGER Length, IN PEPROCESS Process, IN ULONG Key, IN PVOID Context OPTIONAL, IN BOOLEAN AlreadySynchronized)
NTSTATUS NTAPI	FsRtlFastUnlockAll (IN PFILE_LOCK FileLock, IN PFILE_OBJECT FileObject, IN PEPROCESS Process, IN PVOID Context OPTIONAL)
NTSTATUS NTAPI	FsRtlFastUnlockAllByKey (IN PFILE_LOCK FileLock, IN PFILE_OBJECT FileObject, IN PEPROCESS Process, IN ULONG Key, IN PVOID Context OPTIONAL)
NTSTATUS NTAPI	FsRtlProcessFileLock (IN PFILE_LOCK FileLock, IN PIRP Irp, IN PVOID Context OPTIONAL)
VOID NTAPI	FsRtlInitializeFileLock (IN PFILE_LOCK FileLock, IN PCOMPLETE_LOCK_IRP_ROUTINE CompleteLockIrpRoutine OPTIONAL, IN PUNLOCK_ROUTINE UnlockRoutine OPTIONAL)
VOID NTAPI	FsRtlUninitializeFileLock (IN PFILE_LOCK FileLock)
PFILE_LOCK NTAPI	FsRtlAllocateFileLock (IN PCOMPLETE_LOCK_IRP_ROUTINE CompleteLockIrpRoutine OPTIONAL, IN PUNLOCK_ROUTINE UnlockRoutine OPTIONAL)
VOID NTAPI	FsRtlFreeFileLock (IN PFILE_LOCK FileLock)

Variables
PAGED_LOOKASIDE_LIST	FsRtlFileLockLookasideList

Macro Definition Documentation

NDEBUG

#define NDEBUG

Definition at line 12 of file filelock.c.

TAG_FLOCK

#define TAG_FLOCK   'FLCK'

Definition at line 56 of file filelock.c.

TAG_RANGE

#define TAG_RANGE   'FSRA'

Definition at line 55 of file filelock.c.

TAG_TABLE

#define TAG_TABLE   'LTAB'

Definition at line 54 of file filelock.c.

Typedef Documentation

COMBINED_LOCK_ELEMENT

typedef union _COMBINED_LOCK_ELEMENT COMBINED_LOCK_ELEMENT

LOCK_INFORMATION

typedef struct _LOCK_INFORMATION LOCK_INFORMATION

LOCK_SHARED_RANGE

typedef struct _LOCK_SHARED_RANGE LOCK_SHARED_RANGE

PCOMBINED_LOCK_ELEMENT

typedef union _COMBINED_LOCK_ELEMENT * PCOMBINED_LOCK_ELEMENT

PLOCK_INFORMATION

typedef struct _LOCK_INFORMATION * PLOCK_INFORMATION

PLOCK_SHARED_RANGE

typedef struct _LOCK_SHARED_RANGE * PLOCK_SHARED_RANGE

Function Documentation

FsRtlAllocateFileLock()

PFILE_LOCK NTAPI FsRtlAllocateFileLock	(	IN PCOMPLETE_LOCK_IRP_ROUTINE CompleteLockIrpRoutine	OPTIONAL,
		IN PUNLOCK_ROUTINE UnlockRoutine	OPTIONAL
	)

Definition at line 1314 of file filelock.c.

{
    PFILE_LOCK FileLock;
    
    /* Try to allocate it */
    FileLock = ExAllocateFromPagedLookasideList(&FsRtlFileLockLookasideList);
    if (FileLock)
    {
        /* Initialize it */
        FsRtlInitializeFileLock(FileLock,
                                CompleteLockIrpRoutine,
                                UnlockRoutine);
    }
    
    /* Return the lock */
    return FileLock;
}

Referenced by _At_().

FsRtlCheckLockForReadAccess()

BOOLEAN NTAPI FsRtlCheckLockForReadAccess	(	IN PFILE_LOCK	FileLock,
		IN PIRP	Irp
	)

Definition at line 676 of file filelock.c.

{
    BOOLEAN Result;
    PIO_STACK_LOCATION IoStack = IoGetCurrentIrpStackLocation(Irp);
    COMBINED_LOCK_ELEMENT ToFind;
    PCOMBINED_LOCK_ELEMENT Found;
    DPRINT("CheckLockForReadAccess(%wZ, Offset %08x%08x, Length %x)\n", 
           &IoStack->FileObject->FileName,
           IoStack->Parameters.Read.ByteOffset.HighPart,
           IoStack->Parameters.Read.ByteOffset.LowPart,
           IoStack->Parameters.Read.Length);
    if (!FileLock->LockInformation) {
        DPRINT("CheckLockForReadAccess(%wZ) => TRUE\n", &IoStack->FileObject->FileName);
        return TRUE;
    }
    ToFind.Exclusive.FileLock.StartingByte = IoStack->Parameters.Read.ByteOffset;
    ToFind.Exclusive.FileLock.EndingByte.QuadPart = 
        ToFind.Exclusive.FileLock.StartingByte.QuadPart + 
        IoStack->Parameters.Read.Length;
    Found = RtlLookupElementGenericTable
        (FileLock->LockInformation,
         &ToFind);
    if (!Found) {
        DPRINT("CheckLockForReadAccess(%wZ) => TRUE\n", &IoStack->FileObject->FileName);
        return TRUE;
    }
    Result = !Found->Exclusive.FileLock.ExclusiveLock || 
        IoStack->Parameters.Read.Key == Found->Exclusive.FileLock.Key;
    DPRINT("CheckLockForReadAccess(%wZ) => %s\n", &IoStack->FileObject->FileName, Result ? "TRUE" : "FALSE");
    return Result;
}

Referenced by _Requires_lock_held_(), do_read(), Ext2ReadFile(), FFSReadFile(), RfsdReadFile(), RxCommonRead(), UDFCommonRead(), and VfatCommonRead().

FsRtlCheckLockForWriteAccess()

BOOLEAN NTAPI FsRtlCheckLockForWriteAccess	(	IN PFILE_LOCK	FileLock,
		IN PIRP	Irp
	)

Definition at line 714 of file filelock.c.

{
    BOOLEAN Result;
    PIO_STACK_LOCATION IoStack = IoGetCurrentIrpStackLocation(Irp);
    COMBINED_LOCK_ELEMENT ToFind;
    PCOMBINED_LOCK_ELEMENT Found;
    PEPROCESS Process = Irp->Tail.Overlay.Thread->ThreadsProcess;
    DPRINT("CheckLockForWriteAccess(%wZ, Offset %08x%08x, Length %x)\n", 
           &IoStack->FileObject->FileName,
           IoStack->Parameters.Write.ByteOffset.HighPart,
           IoStack->Parameters.Write.ByteOffset.LowPart,
           IoStack->Parameters.Write.Length);
    if (!FileLock->LockInformation) {
        DPRINT("CheckLockForWriteAccess(%wZ) => TRUE\n", &IoStack->FileObject->FileName);
        return TRUE;
    }
    ToFind.Exclusive.FileLock.StartingByte = IoStack->Parameters.Write.ByteOffset;
    ToFind.Exclusive.FileLock.EndingByte.QuadPart = 
        ToFind.Exclusive.FileLock.StartingByte.QuadPart + 
        IoStack->Parameters.Write.Length;
    Found = RtlLookupElementGenericTable
        (FileLock->LockInformation,
         &ToFind);
    if (!Found) {
        DPRINT("CheckLockForWriteAccess(%wZ) => TRUE\n", &IoStack->FileObject->FileName);
        return TRUE;
    }
    Result = Process == Found->Exclusive.FileLock.ProcessId;
    DPRINT("CheckLockForWriteAccess(%wZ) => %s\n", &IoStack->FileObject->FileName, Result ? "TRUE" : "FALSE");
    return Result;
}

Referenced by _Requires_lock_held_(), Ext2WriteFile(), FFSWriteFile(), RfsdWriteFile(), RxCommonWrite(), UDFCommonWrite(), VfatWrite(), and write_file().

FsRtlCompleteLockIrpReal()

VOID NTAPI FsRtlCompleteLockIrpReal	(	IN PCOMPLETE_LOCK_IRP_ROUTINE	CompleteRoutine,
		IN PVOID	Context,
		IN PIRP	Irp,
		IN NTSTATUS	Status,
		OUT PNTSTATUS	NewStatus,
		IN PFILE_OBJECT FileObject	OPTIONAL
	)

Definition at line 224 of file filelock.c.

{
    /* Check if we have a complete routine */
    Irp->IoStatus.Information = 0;
    if (CompleteRoutine)
    {
        /* Check if we have a file object */
        if (FileObject) FileObject->LastLock = NULL;
        
        /* Set the I/O Status and do completion */
        Irp->IoStatus.Status = Status;
        DPRINT("Calling completion routine %p Status %x\n", Irp, Status);
        *NewStatus = CompleteRoutine(Context, Irp);
    }
    else
    {
        /* Otherwise do a normal I/O complete request */
        DPRINT("Completing IRP %p Status %x\n", Irp, Status);
        FsRtlCompleteRequest(Irp, Status);
        *NewStatus = Status;
    }
}

Referenced by FsRtlPrivateLock(), FsRtlProcessFileLock(), and LockCompleteCanceledIrp().

FsRtlFastCheckLockForRead()

BOOLEAN NTAPI FsRtlFastCheckLockForRead	(	IN PFILE_LOCK	FileLock,
		IN PLARGE_INTEGER	FileOffset,
		IN PLARGE_INTEGER	Length,
		IN ULONG	Key,
		IN PFILE_OBJECT	FileObject,
		IN PVOID	Process
	)

Definition at line 752 of file filelock.c.

{
    PEPROCESS EProcess = Process;
    COMBINED_LOCK_ELEMENT ToFind;
    PCOMBINED_LOCK_ELEMENT Found;
    DPRINT("FsRtlFastCheckLockForRead(%wZ, Offset %08x%08x, Length %08x%08x, Key %x)\n", 
           &FileObject->FileName, 
           FileOffset->HighPart,
           FileOffset->LowPart, 
           Length->HighPart,
           Length->LowPart,
           Key);
    ToFind.Exclusive.FileLock.StartingByte = *FileOffset;
    ToFind.Exclusive.FileLock.EndingByte.QuadPart = 
        FileOffset->QuadPart + Length->QuadPart;
    if (!FileLock->LockInformation) return TRUE;
    Found = RtlLookupElementGenericTable
        (FileLock->LockInformation,
         &ToFind);
    if (!Found || !Found->Exclusive.FileLock.ExclusiveLock) return TRUE;
    return Found->Exclusive.FileLock.Key == Key && 
        Found->Exclusive.FileLock.ProcessId == EProcess;
}

Referenced by _Function_class_(), duplicate_extents(), Ext2FastIoCheckIfPossible(), FFSFastIoCheckIfPossible(), RfsdFastIoCheckIfPossible(), RxFastIoCheckIfPossible(), and UDFFastIoCheckIfPossible().

FsRtlFastCheckLockForWrite()

BOOLEAN NTAPI FsRtlFastCheckLockForWrite	(	IN PFILE_LOCK	FileLock,
		IN PLARGE_INTEGER	FileOffset,
		IN PLARGE_INTEGER	Length,
		IN ULONG	Key,
		IN PFILE_OBJECT	FileObject,
		IN PVOID	Process
	)

Definition at line 786 of file filelock.c.

{
    BOOLEAN Result;
    PEPROCESS EProcess = Process;
    COMBINED_LOCK_ELEMENT ToFind;
    PCOMBINED_LOCK_ELEMENT Found;
    DPRINT("FsRtlFastCheckLockForWrite(%wZ, Offset %08x%08x, Length %08x%08x, Key %x)\n", 
           &FileObject->FileName, 
           FileOffset->HighPart,
           FileOffset->LowPart, 
           Length->HighPart,
           Length->LowPart,
           Key);
    ToFind.Exclusive.FileLock.StartingByte = *FileOffset;
    ToFind.Exclusive.FileLock.EndingByte.QuadPart = 
        FileOffset->QuadPart + Length->QuadPart;
    if (!FileLock->LockInformation) {
        DPRINT("CheckForWrite(%wZ) => TRUE\n", &FileObject->FileName);
        return TRUE;
    }
    Found = RtlLookupElementGenericTable
        (FileLock->LockInformation,
         &ToFind);
    if (!Found) {
        DPRINT("CheckForWrite(%wZ) => TRUE\n", &FileObject->FileName);
        return TRUE;
    }
    Result = Found->Exclusive.FileLock.Key == Key && 
        Found->Exclusive.FileLock.ProcessId == EProcess;
    DPRINT("CheckForWrite(%wZ) => %s\n", &FileObject->FileName, Result ? "TRUE" : "FALSE");
    return Result;
}

Referenced by _Function_class_(), duplicate_extents(), Ext2FastIoCheckIfPossible(), FFSFastIoCheckIfPossible(), RfsdFastIoCheckIfPossible(), RxFastIoCheckIfPossible(), and UDFFastIoCheckIfPossible().

FsRtlFastUnlockAll()

NTSTATUS NTAPI FsRtlFastUnlockAll	(	IN PFILE_LOCK	FileLock,
		IN PFILE_OBJECT	FileObject,
		IN PEPROCESS	Process,
		IN PVOID Context	OPTIONAL
	)

Definition at line 1026 of file filelock.c.

{
    PLIST_ENTRY ListEntry;
    PCOMBINED_LOCK_ELEMENT Entry;
    PLOCK_INFORMATION InternalInfo = FileLock->LockInformation;
    DPRINT("FsRtlFastUnlockAll(%wZ)\n", &FileObject->FileName);
    // XXX Synchronize somehow
    if (!FileLock->LockInformation) {
        DPRINT("Not locked %wZ\n", &FileObject->FileName);
        return STATUS_RANGE_NOT_LOCKED; // no locks
    }
    for (ListEntry = InternalInfo->SharedLocks.Flink;
         ListEntry != &InternalInfo->SharedLocks;)
    {
        LARGE_INTEGER Length;
        PLOCK_SHARED_RANGE Range = CONTAINING_RECORD(ListEntry, LOCK_SHARED_RANGE, Entry);
        Length.QuadPart = Range->End.QuadPart - Range->Start.QuadPart;
        ListEntry = ListEntry->Flink;
        if (Range->ProcessId != Process)
            continue;
        FsRtlFastUnlockSingle
            (FileLock,
             FileObject,
             &Range->Start,
             &Length,
             Range->ProcessId,
             Range->Key,
             Context,
             TRUE);
    }
    for (Entry = RtlEnumerateGenericTable(&InternalInfo->RangeTable, TRUE);
         Entry;
         Entry = RtlEnumerateGenericTable(&InternalInfo->RangeTable, FALSE))
    {
        LARGE_INTEGER Length;
        // We'll take the first one to be the list head, and free the others first...
        Length.QuadPart = 
            Entry->Exclusive.FileLock.EndingByte.QuadPart - 
            Entry->Exclusive.FileLock.StartingByte.QuadPart;
        FsRtlFastUnlockSingle
            (FileLock, 
             Entry->Exclusive.FileLock.FileObject,
             &Entry->Exclusive.FileLock.StartingByte,
             &Length,
             Entry->Exclusive.FileLock.ProcessId,
             Entry->Exclusive.FileLock.Key,
             Context,
             TRUE);
    }
    DPRINT("Done %wZ\n", &FileObject->FileName);
    return STATUS_SUCCESS;
}

Referenced by _Function_class_(), _Requires_lock_held_(), CdFastUnlockAll(), Ext2Cleanup(), Ext2FastIoUnlockAll(), FFSCleanup(), FFSFastIoUnlockAll(), FsRtlProcessFileLock(), RfsdCleanup(), RfsdFastIoUnlockAll(), RxCommonCleanup(), UDFCommonCleanup(), UDFFastUnlockAll(), and VfatCleanupFile().

FsRtlFastUnlockAllByKey()

NTSTATUS NTAPI FsRtlFastUnlockAllByKey	(	IN PFILE_LOCK	FileLock,
		IN PFILE_OBJECT	FileObject,
		IN PEPROCESS	Process,
		IN ULONG	Key,
		IN PVOID Context	OPTIONAL
	)

Definition at line 1087 of file filelock.c.

{
    PLIST_ENTRY ListEntry;
    PCOMBINED_LOCK_ELEMENT Entry;
    PLOCK_INFORMATION InternalInfo = FileLock->LockInformation;
    
    DPRINT("FsRtlFastUnlockAllByKey(%wZ,Key %x)\n", &FileObject->FileName, Key);
    
    // XXX Synchronize somehow
    if (!FileLock->LockInformation) return STATUS_RANGE_NOT_LOCKED; // no locks
    for (ListEntry = InternalInfo->SharedLocks.Flink;
         ListEntry != &InternalInfo->SharedLocks;)
    {
        PLOCK_SHARED_RANGE Range = CONTAINING_RECORD(ListEntry, LOCK_SHARED_RANGE, Entry);
        LARGE_INTEGER Length;
        Length.QuadPart = Range->End.QuadPart - Range->Start.QuadPart;
        ListEntry = ListEntry->Flink;
        if (Range->ProcessId != Process ||
            Range->Key != Key)
            continue;
        FsRtlFastUnlockSingle
            (FileLock,
             FileObject,
             &Range->Start,
             &Length,
             Range->ProcessId,
             Range->Key,
             Context,
             TRUE);
    }
    for (Entry = RtlEnumerateGenericTable(&InternalInfo->RangeTable, TRUE);
         Entry;
         Entry = RtlEnumerateGenericTable(&InternalInfo->RangeTable, FALSE))
    {
        LARGE_INTEGER Length;
        // We'll take the first one to be the list head, and free the others first...
        Length.QuadPart = 
            Entry->Exclusive.FileLock.EndingByte.QuadPart - 
            Entry->Exclusive.FileLock.StartingByte.QuadPart;
        if (Entry->Exclusive.FileLock.Key == Key && 
            Entry->Exclusive.FileLock.ProcessId == Process)
        {
            FsRtlFastUnlockSingle
                (FileLock, 
                 Entry->Exclusive.FileLock.FileObject,
                 &Entry->Exclusive.FileLock.StartingByte,
                 &Length,
                 Entry->Exclusive.FileLock.ProcessId,
                 Entry->Exclusive.FileLock.Key,
                 Context,
                 TRUE);
        }
    }
    
    return STATUS_SUCCESS;
}

Referenced by _Function_class_(), CdFastUnlockAllByKey(), Ext2FastIoUnlockAllByKey(), FFSFastIoUnlockAllByKey(), FsRtlProcessFileLock(), RfsdFastIoUnlockAllByKey(), and UDFFastUnlockAllByKey().

FsRtlFastUnlockSingle()

NTSTATUS NTAPI FsRtlFastUnlockSingle	(	IN PFILE_LOCK	FileLock,
		IN PFILE_OBJECT	FileObject,
		IN PLARGE_INTEGER	FileOffset,
		IN PLARGE_INTEGER	Length,
		IN PEPROCESS	Process,
		IN ULONG	Key,
		IN PVOID Context	OPTIONAL,
		IN BOOLEAN	AlreadySynchronized
	)

Definition at line 829 of file filelock.c.

{
    BOOLEAN FoundShared = FALSE;
    PLIST_ENTRY SharedEntry;
    PLOCK_SHARED_RANGE SharedRange = NULL;
    COMBINED_LOCK_ELEMENT Find;
    PCOMBINED_LOCK_ELEMENT Entry;
    PIRP NextMatchingLockIrp;
    PLOCK_INFORMATION InternalInfo = FileLock->LockInformation;
    DPRINT("FsRtlFastUnlockSingle(%wZ, Offset %08x%08x (%d), Length %08x%08x (%d), Key %x)\n", 
           &FileObject->FileName, 
           FileOffset->HighPart,
           FileOffset->LowPart, 
           (int)FileOffset->QuadPart,
           Length->HighPart,
           Length->LowPart,
           (int)Length->QuadPart,
           Key);
    // The region to unlock must correspond exactly to a previously locked region
    // -- msdn
    // But Windows 2003 doesn't assert on it and simply ignores that parameter
    // ASSERT(AlreadySynchronized);
    Find.Exclusive.FileLock.StartingByte = *FileOffset;
    Find.Exclusive.FileLock.EndingByte.QuadPart = 
        FileOffset->QuadPart + Length->QuadPart;
    if (!InternalInfo) {
        DPRINT("File not previously locked (ever)\n");
        return STATUS_RANGE_NOT_LOCKED;
    }
    Entry = RtlLookupElementGenericTable(&InternalInfo->RangeTable, &Find);
    if (!Entry) {
        DPRINT("Range not locked %wZ\n", &FileObject->FileName);
        return STATUS_RANGE_NOT_LOCKED;
    }

    DPRINT("Found lock entry: Exclusive %u %08x%08x:%08x%08x %wZ\n",
           Entry->Exclusive.FileLock.ExclusiveLock,
           Entry->Exclusive.FileLock.StartingByte.HighPart,
           Entry->Exclusive.FileLock.StartingByte.LowPart,
           Entry->Exclusive.FileLock.EndingByte.HighPart,
           Entry->Exclusive.FileLock.EndingByte.LowPart,
           &FileObject->FileName);
    
    if (Entry->Exclusive.FileLock.ExclusiveLock)
    {
        if (Entry->Exclusive.FileLock.Key != Key ||
            Entry->Exclusive.FileLock.ProcessId != Process ||
            Entry->Exclusive.FileLock.StartingByte.QuadPart != FileOffset->QuadPart ||
            Entry->Exclusive.FileLock.EndingByte.QuadPart != 
            FileOffset->QuadPart + Length->QuadPart)
        {
            DPRINT("Range not locked %wZ\n", &FileObject->FileName);
            return STATUS_RANGE_NOT_LOCKED;
        }
        RtlCopyMemory(&Find, Entry, sizeof(Find));
        // Remove the old exclusive lock region
        RtlDeleteElementGenericTable(&InternalInfo->RangeTable, Entry);
    }
    else
    {
        DPRINT("Shared lock %wZ Start %08x%08x End %08x%08x\n", 
               &FileObject->FileName,
               Entry->Exclusive.FileLock.StartingByte.HighPart,
               Entry->Exclusive.FileLock.StartingByte.LowPart,
               Entry->Exclusive.FileLock.EndingByte.HighPart,
               Entry->Exclusive.FileLock.EndingByte.LowPart);
        for (SharedEntry = InternalInfo->SharedLocks.Flink;
             SharedEntry != &InternalInfo->SharedLocks;
             SharedEntry = SharedEntry->Flink)
        {
            SharedRange = CONTAINING_RECORD(SharedEntry, LOCK_SHARED_RANGE, Entry);
            if (SharedRange->Start.QuadPart == FileOffset->QuadPart &&
                SharedRange->End.QuadPart == FileOffset->QuadPart + Length->QuadPart &&
                SharedRange->Key == Key &&
                SharedRange->ProcessId == Process)
            {
                FoundShared = TRUE;
                DPRINT("Found shared element to delete %wZ Start %08x%08x End %08x%08x Key %x\n",
                       &FileObject->FileName,
                       SharedRange->Start.HighPart,
                       SharedRange->Start.LowPart,
                       SharedRange->End.HighPart,
                       SharedRange->End.LowPart,
                       SharedRange->Key);
                break;
            }
        }
        if (FoundShared)
        {
            /* Remove the found range from the shared range lists */
            RemoveEntryList(&SharedRange->Entry);
            ExFreePoolWithTag(SharedRange, TAG_RANGE);
            /* We need to rebuild the list of shared ranges. */
            DPRINT("Removing the lock entry %wZ (%08x%08x:%08x%08x)\n", 
                   &FileObject->FileName, 
                   Entry->Exclusive.FileLock.StartingByte.HighPart, 
                   Entry->Exclusive.FileLock.StartingByte.LowPart,
                   Entry->Exclusive.FileLock.EndingByte.HighPart, 
                   Entry->Exclusive.FileLock.EndingByte.LowPart);
               
            /* Remember what was in there and remove it from the table */
            Find = *Entry;
            RtlDeleteElementGenericTable(&InternalInfo->RangeTable, &Find);
            /* Put shared locks back in place */
            for (SharedEntry = InternalInfo->SharedLocks.Flink;
                 SharedEntry != &InternalInfo->SharedLocks;
                 SharedEntry = SharedEntry->Flink)
            {
                COMBINED_LOCK_ELEMENT LockElement;
                SharedRange = CONTAINING_RECORD(SharedEntry, LOCK_SHARED_RANGE, Entry);
                LockElement.Exclusive.FileLock.FileObject = FileObject;
                LockElement.Exclusive.FileLock.StartingByte = SharedRange->Start;
                LockElement.Exclusive.FileLock.EndingByte = SharedRange->End;
                LockElement.Exclusive.FileLock.ProcessId = SharedRange->ProcessId;
                LockElement.Exclusive.FileLock.Key = SharedRange->Key;
                LockElement.Exclusive.FileLock.ExclusiveLock = FALSE;
                
                if (LockCompare(&InternalInfo->RangeTable, &Find, &LockElement) != GenericEqual)
                {
                    DPRINT("Skipping range %08x%08x:%08x%08x\n",
                           LockElement.Exclusive.FileLock.StartingByte.HighPart,
                           LockElement.Exclusive.FileLock.StartingByte.LowPart,
                           LockElement.Exclusive.FileLock.EndingByte.HighPart,
                           LockElement.Exclusive.FileLock.EndingByte.LowPart);
                    continue;
                }
                DPRINT("Re-creating range %08x%08x:%08x%08x\n",
                       LockElement.Exclusive.FileLock.StartingByte.HighPart,
                       LockElement.Exclusive.FileLock.StartingByte.LowPart,
                       LockElement.Exclusive.FileLock.EndingByte.HighPart,
                       LockElement.Exclusive.FileLock.EndingByte.LowPart);
                FsRtlpRebuildSharedLockRange(FileLock, InternalInfo, &LockElement);
            }
        }
        else
        {
            return STATUS_RANGE_NOT_LOCKED;
        }
    }

#ifndef NDEBUG    
    DPRINT("Lock still has:\n");
    for (SharedEntry = InternalInfo->SharedLocks.Flink;
         SharedEntry != &InternalInfo->SharedLocks;
         SharedEntry = SharedEntry->Flink)
    {
        SharedRange = CONTAINING_RECORD(SharedEntry, LOCK_SHARED_RANGE, Entry);
        DPRINT("Shared element %wZ Offset %08x%08x Length %08x%08x Key %x\n",
               &FileObject->FileName,
               SharedRange->Start.HighPart,
               SharedRange->Start.LowPart,
               SharedRange->End.HighPart,
               SharedRange->End.LowPart,
               SharedRange->Key);
    }
#endif
    
    // this is definitely the thing we want
    InternalInfo->Generation++;
    while ((NextMatchingLockIrp = IoCsqRemoveNextIrp(&InternalInfo->Csq, &Find)))
    {
        if (NextMatchingLockIrp->IoStatus.Information == InternalInfo->Generation)
        {
            // We've already looked at this one, meaning that we looped.  
            // Put it back and exit.
            IoCsqInsertIrpEx
                (&InternalInfo->Csq,
                 NextMatchingLockIrp,
                 NULL,
                 NULL);
            break;
        }
        // Got a new lock irp... try to do the new lock operation
        // Note that we pick an operation that would succeed at the time
        // we looked, but can't guarantee that it won't just be re-queued
        // because somebody else snatched part of the range in a new thread.
        DPRINT("Locking another IRP %p for %p %wZ\n", 
               NextMatchingLockIrp, FileLock, &FileObject->FileName);
        FsRtlProcessFileLock(InternalInfo->BelongsTo, NextMatchingLockIrp, NULL);
    }
    
    DPRINT("Success %wZ\n", &FileObject->FileName);
    return STATUS_SUCCESS;
}

Referenced by _Function_class_(), CdFastUnlockSingle(), Ext2FastIoUnlockSingle(), FFSFastIoUnlockSingle(), FsRtlFastUnlockAll(), FsRtlFastUnlockAllByKey(), FsRtlProcessFileLock(), RfsdFastIoUnlockSingle(), and UDFFastUnlockSingle().

FsRtlFreeFileLock()

VOID NTAPI FsRtlFreeFileLock

(

IN PFILE_LOCK

FileLock

)

Definition at line 1338 of file filelock.c.

{
    /* Uninitialize and free the lock */
    FsRtlUninitializeFileLock(FileLock);
    ExFreeToPagedLookasideList(&FsRtlFileLockLookasideList, FileLock);
}

Referenced by CdDeleteFcb().

FsRtlGetNextFileLock()

PFILE_LOCK_INFO NTAPI FsRtlGetNextFileLock	(	IN PFILE_LOCK	FileLock,
		IN BOOLEAN	Restart
	)

Definition at line 259 of file filelock.c.

{
    PCOMBINED_LOCK_ELEMENT Entry;
    if (!FileLock->LockInformation) return NULL;
    Entry = RtlEnumerateGenericTable(FileLock->LockInformation, Restart);
    if (!Entry) return NULL;
    else return &Entry->Exclusive.FileLock;
}

Referenced by Ext2Cleanup(), FFSCleanup(), and RfsdCleanup().

FsRtlInitializeFileLock()

VOID NTAPI FsRtlInitializeFileLock	(	IN PFILE_LOCK	FileLock,
		IN PCOMPLETE_LOCK_IRP_ROUTINE CompleteLockIrpRoutine	OPTIONAL,
		IN PUNLOCK_ROUTINE UnlockRoutine	OPTIONAL
	)

Definition at line 1261 of file filelock.c.

{
    /* Setup the lock */
    RtlZeroMemory(FileLock, sizeof(*FileLock));
    FileLock->FastIoIsQuestionable = FALSE;
    FileLock->CompleteLockIrpRoutine = CompleteLockIrpRoutine;
    FileLock->UnlockRoutine = UnlockRoutine;
    FileLock->LockInformation = NULL;
}

Referenced by create_fcb(), Ext2AllocateFcb(), FatCreateFcb(), FFSv1AllocateFcb(), FFSv2AllocateFcb(), FsRtlAllocateFileLock(), RfsdAllocateFcb(), RxFinishFcbInitialization(), UDFInitializeFCB(), and vfatNewFCB().

FsRtlpExpandLockElement()

VOID NTAPI FsRtlpExpandLockElement	(	PCOMBINED_LOCK_ELEMENT	ToExpand,
		PCOMBINED_LOCK_ELEMENT	Conflict
	)

Definition at line 272 of file filelock.c.

{
    if (ToExpand->Exclusive.FileLock.StartingByte.QuadPart >
        Conflict->Exclusive.FileLock.StartingByte.QuadPart)
    {
        ToExpand->Exclusive.FileLock.StartingByte = 
            Conflict->Exclusive.FileLock.StartingByte;
    }
    if (ToExpand->Exclusive.FileLock.EndingByte.QuadPart <
        Conflict->Exclusive.FileLock.EndingByte.QuadPart)
    {
        ToExpand->Exclusive.FileLock.EndingByte =
            Conflict->Exclusive.FileLock.EndingByte;
    }
}

Referenced by FsRtlpRebuildSharedLockRange().

FsRtlpRebuildSharedLockRange()

PCOMBINED_LOCK_ELEMENT NTAPI FsRtlpRebuildSharedLockRange	(	PFILE_LOCK	FileLock,
		PLOCK_INFORMATION	LockInfo,
		PCOMBINED_LOCK_ELEMENT	Conflict
	)

Definition at line 294 of file filelock.c.

{
    /* Starting at Conflict->StartingByte and going to Conflict->EndingByte
     * capture and expand a shared range from the shared range list.
     * Finish when we've incorporated all overlapping shared regions.
     */
    BOOLEAN InsertedNew = FALSE, RemovedOld;
    COMBINED_LOCK_ELEMENT NewElement = *Conflict;
    PCOMBINED_LOCK_ELEMENT Entry;
    while ((Entry = RtlLookupElementGenericTable
            (FileLock->LockInformation, &NewElement)))
    {
        FsRtlpExpandLockElement(&NewElement, Entry);
        RemovedOld = RtlDeleteElementGenericTable
            (&LockInfo->RangeTable,
             Entry);
        ASSERT(RemovedOld);
    }
    Conflict = RtlInsertElementGenericTable
        (&LockInfo->RangeTable,
         &NewElement,
         sizeof(NewElement),
         &InsertedNew);
    ASSERT(InsertedNew);
    return Conflict;
}

Referenced by FsRtlFastUnlockSingle(), and FsRtlPrivateLock().

FsRtlPrivateLock()

BOOLEAN NTAPI FsRtlPrivateLock	(	IN PFILE_LOCK	FileLock,
		IN PFILE_OBJECT	FileObject,
		IN PLARGE_INTEGER	FileOffset,
		IN PLARGE_INTEGER	Length,
		IN PEPROCESS	Process,
		IN ULONG	Key,
		IN BOOLEAN	FailImmediately,
		IN BOOLEAN	ExclusiveLock,
		OUT PIO_STATUS_BLOCK	IoStatus,
		IN PIRP Irp	OPTIONAL,
		IN PVOID Context	OPTIONAL,
		IN BOOLEAN	AlreadySynchronized
	)

Definition at line 328 of file filelock.c.

{
    NTSTATUS Status;
    COMBINED_LOCK_ELEMENT ToInsert;
    PCOMBINED_LOCK_ELEMENT Conflict;
    PLOCK_INFORMATION LockInfo;
    PLOCK_SHARED_RANGE NewSharedRange;
    BOOLEAN InsertedNew;
    ULARGE_INTEGER UnsignedStart;
    ULARGE_INTEGER UnsignedEnd;
    
    DPRINT("FsRtlPrivateLock(%wZ, Offset %08x%08x (%d), Length %08x%08x (%d), Key %x, FailImmediately %u, Exclusive %u)\n", 
           &FileObject->FileName, 
           FileOffset->HighPart,
           FileOffset->LowPart, 
           (int)FileOffset->QuadPart,
           Length->HighPart,
           Length->LowPart, 
           (int)Length->QuadPart,
           Key,
           FailImmediately, 
           ExclusiveLock);
    
    UnsignedStart.QuadPart = FileOffset->QuadPart;
    UnsignedEnd.QuadPart = FileOffset->QuadPart + Length->QuadPart;

    if (UnsignedEnd.QuadPart < UnsignedStart.QuadPart)
    {
        DPRINT("File offset out of range\n");
        IoStatus->Status = STATUS_INVALID_PARAMETER;
        if (Irp)
        {
            DPRINT("Complete lock %p Status %x\n", Irp, IoStatus->Status);
            FsRtlCompleteLockIrpReal
                (FileLock->CompleteLockIrpRoutine,
                 Context,
                 Irp,
                 IoStatus->Status,
                 &Status,
                 FileObject);
        }
        return FALSE;
    }
    
    /* Initialize the lock, if necessary */
    if (!FileLock->LockInformation)
    {
        LockInfo = ExAllocatePoolWithTag(NonPagedPool, sizeof(LOCK_INFORMATION), TAG_FLOCK);
        if (!LockInfo)
        {
            IoStatus->Status = STATUS_NO_MEMORY;
            return FALSE;
        }
        FileLock->LockInformation = LockInfo;

        LockInfo->BelongsTo = FileLock;
        InitializeListHead(&LockInfo->SharedLocks);
        
        RtlInitializeGenericTable
            (&LockInfo->RangeTable,
             LockCompare,
             LockAllocate,
             LockFree,
             NULL);
        
        KeInitializeSpinLock(&LockInfo->CsqLock);
        InitializeListHead(&LockInfo->CsqList);
        
        IoCsqInitializeEx
            (&LockInfo->Csq, 
             LockInsertIrpEx,
             LockRemoveIrp,
             LockPeekNextIrp,
             LockAcquireQueueLock,
             LockReleaseQueueLock,
             LockCompleteCanceledIrp);
    }
    
    LockInfo = FileLock->LockInformation;
    ToInsert.Exclusive.FileLock.FileObject = FileObject;
    ToInsert.Exclusive.FileLock.StartingByte = *FileOffset;
    ToInsert.Exclusive.FileLock.EndingByte.QuadPart = FileOffset->QuadPart + Length->QuadPart;
    ToInsert.Exclusive.FileLock.ProcessId = Process;
    ToInsert.Exclusive.FileLock.Key = Key;
    ToInsert.Exclusive.FileLock.ExclusiveLock = ExclusiveLock;

    Conflict = RtlInsertElementGenericTable
        (FileLock->LockInformation,
         &ToInsert,
         sizeof(ToInsert),
         &InsertedNew);

    if (Conflict && !InsertedNew)
    {
        if (Conflict->Exclusive.FileLock.ExclusiveLock || ExclusiveLock)
        {
            DPRINT("Conflict %08x%08x:%08x%08x Exc %u (Want Exc %u)\n",
                   Conflict->Exclusive.FileLock.StartingByte.HighPart,
                   Conflict->Exclusive.FileLock.StartingByte.LowPart,
                   Conflict->Exclusive.FileLock.EndingByte.HighPart,
                   Conflict->Exclusive.FileLock.EndingByte.LowPart,
                   Conflict->Exclusive.FileLock.ExclusiveLock,
                   ExclusiveLock);
            if (FailImmediately)
            {
                DPRINT("STATUS_FILE_LOCK_CONFLICT\n");
                IoStatus->Status = STATUS_FILE_LOCK_CONFLICT;
                if (Irp)
                {
                    DPRINT("STATUS_FILE_LOCK_CONFLICT: Complete\n");
                    FsRtlCompleteLockIrpReal
                        (FileLock->CompleteLockIrpRoutine,
                         Context,
                         Irp,
                         IoStatus->Status,
                         &Status,
                         FileObject);
                }
                return FALSE;
            }
            else
            {
                IoStatus->Status = STATUS_PENDING;
                if (Irp)
                {
                    Irp->IoStatus.Information = LockInfo->Generation;
                    IoMarkIrpPending(Irp);
                    IoCsqInsertIrpEx
                        (&LockInfo->Csq,
                         Irp,
                         NULL,
                         NULL);
                }
            }
            return FALSE;
        }
        else
        {
            ULONG i;
            /* We know of at least one lock in range that's shared.  We need to
             * find out if any more exist and any are exclusive. */
            for (i = 0; i < RtlNumberGenericTableElements(&LockInfo->RangeTable); i++)
            {
                Conflict = RtlGetElementGenericTable(&LockInfo->RangeTable, i);

                /* The first argument will be inserted as a shared range */
                if (Conflict && (LockCompare(&LockInfo->RangeTable, Conflict, &ToInsert) == GenericEqual))
                {
                    if (Conflict->Exclusive.FileLock.ExclusiveLock)
                    {
                        /* Found an exclusive match */
                        if (FailImmediately)
                        {
                            IoStatus->Status = STATUS_FILE_LOCK_CONFLICT;
                            DPRINT("STATUS_FILE_LOCK_CONFLICT\n");
                            if (Irp)
                            {
                                DPRINT("STATUS_FILE_LOCK_CONFLICT: Complete\n");
                                FsRtlCompleteLockIrpReal
                                    (FileLock->CompleteLockIrpRoutine,
                                     Context,
                                     Irp,
                                     IoStatus->Status,
                                     &Status,
                                     FileObject);
                            }
                        }
                        else
                        {
                            IoStatus->Status = STATUS_PENDING;
                            if (Irp)
                            {
                                IoMarkIrpPending(Irp);
                                IoCsqInsertIrpEx
                                    (&LockInfo->Csq,
                                     Irp,
                                     NULL,
                                     NULL);
                            }
                        }
                        return FALSE;
                    }
                }
            }
            
            DPRINT("Overlapping shared lock %wZ %08x%08x %08x%08x\n",
                   &FileObject->FileName,
                   Conflict->Exclusive.FileLock.StartingByte.HighPart,
                   Conflict->Exclusive.FileLock.StartingByte.LowPart,
                   Conflict->Exclusive.FileLock.EndingByte.HighPart,
                   Conflict->Exclusive.FileLock.EndingByte.LowPart);
            Conflict = FsRtlpRebuildSharedLockRange(FileLock,
                                                    LockInfo,
                                                    &ToInsert);
            if (!Conflict)
            {
                IoStatus->Status = STATUS_NO_MEMORY;
                if (Irp)
                {
                    FsRtlCompleteLockIrpReal
                        (FileLock->CompleteLockIrpRoutine,
                         Context,
                         Irp,
                         IoStatus->Status,
                         &Status,
                         FileObject);
                }
            }

            /* We got here because there were only overlapping shared locks */
            /* A shared lock is both a range *and* a list entry.  Insert the
               entry here. */
            
            DPRINT("Adding shared lock %wZ\n", &FileObject->FileName);
            NewSharedRange = 
                ExAllocatePoolWithTag(NonPagedPool, sizeof(*NewSharedRange), TAG_RANGE);
            if (!NewSharedRange)
            {
                IoStatus->Status = STATUS_NO_MEMORY;
                if (Irp)
                {
                    FsRtlCompleteLockIrpReal
                        (FileLock->CompleteLockIrpRoutine,
                         Context,
                         Irp,
                         IoStatus->Status,
                         &Status,
                         FileObject);
                }
                return FALSE;
            }
            DPRINT("Adding shared lock %wZ\n", &FileObject->FileName);
            NewSharedRange->Start = *FileOffset;
            NewSharedRange->End.QuadPart = FileOffset->QuadPart + Length->QuadPart;
            NewSharedRange->Key = Key;
            NewSharedRange->ProcessId = ToInsert.Exclusive.FileLock.ProcessId;
            InsertTailList(&LockInfo->SharedLocks, &NewSharedRange->Entry);

            DPRINT("Acquired shared lock %wZ %08x%08x %08x%08x\n",
                   &FileObject->FileName,
                   Conflict->Exclusive.FileLock.StartingByte.HighPart,
                   Conflict->Exclusive.FileLock.StartingByte.LowPart,
                   Conflict->Exclusive.FileLock.EndingByte.HighPart,
                   Conflict->Exclusive.FileLock.EndingByte.LowPart);
            IoStatus->Status = STATUS_SUCCESS;
            if (Irp)
            {
                FsRtlCompleteLockIrpReal
                    (FileLock->CompleteLockIrpRoutine,
                     Context,
                     Irp,
                     IoStatus->Status,
                     &Status,
                     FileObject);
            }
            return TRUE;
        }
    }
    else if (!Conflict)
    {
        /* Conflict here is (or would be) the newly inserted element, but we ran
         * out of space probably. */
        IoStatus->Status = STATUS_NO_MEMORY;
        if (Irp)
        {
            FsRtlCompleteLockIrpReal
                (FileLock->CompleteLockIrpRoutine,
                 Context,
                 Irp,
                 IoStatus->Status,
                 &Status,
                 FileObject);
        }
        return FALSE;
    }
    else
    {
        DPRINT("Inserted new lock %wZ %08x%08x %08x%08x exclusive %u\n",
               &FileObject->FileName,
               Conflict->Exclusive.FileLock.StartingByte.HighPart,
               Conflict->Exclusive.FileLock.StartingByte.LowPart,
               Conflict->Exclusive.FileLock.EndingByte.HighPart,
               Conflict->Exclusive.FileLock.EndingByte.LowPart,
               Conflict->Exclusive.FileLock.ExclusiveLock);
        if (!ExclusiveLock)
        {
            NewSharedRange = 
                ExAllocatePoolWithTag(NonPagedPool, sizeof(*NewSharedRange), TAG_RANGE);
            if (!NewSharedRange)
            {
                IoStatus->Status = STATUS_NO_MEMORY;
                if (Irp)
                {
                    FsRtlCompleteLockIrpReal
                        (FileLock->CompleteLockIrpRoutine,
                         Context,
                         Irp,
                         IoStatus->Status,
                         &Status,
                         FileObject);
                }
                return FALSE;
            }
            DPRINT("Adding shared lock %wZ\n", &FileObject->FileName);
            NewSharedRange->Start = *FileOffset;
            NewSharedRange->End.QuadPart = FileOffset->QuadPart + Length->QuadPart;
            NewSharedRange->Key = Key;
            NewSharedRange->ProcessId = Process;
            InsertTailList(&LockInfo->SharedLocks, &NewSharedRange->Entry);
        }
        
        /* Assume all is cool, and lock is set */
        IoStatus->Status = STATUS_SUCCESS;
        
        if (Irp)
        {
            /* Complete the request */
            FsRtlCompleteLockIrpReal(FileLock->CompleteLockIrpRoutine,
                                     Context,
                                     Irp,
                                     IoStatus->Status,
                                     &Status,
                                     FileObject);
            
            /* Update the status */
            IoStatus->Status = Status;
        }
    }
    
    return TRUE;
}

Referenced by FsRtlProcessFileLock().

FsRtlProcessFileLock()

NTSTATUS NTAPI FsRtlProcessFileLock	(	IN PFILE_LOCK	FileLock,
		IN PIRP	Irp,
		IN PVOID Context	OPTIONAL
	)

Definition at line 1153 of file filelock.c.

{
    PIO_STACK_LOCATION IoStackLocation;
    NTSTATUS Status;
    IO_STATUS_BLOCK IoStatusBlock;
    
    /* Get the I/O Stack location */
    IoStackLocation = IoGetCurrentIrpStackLocation(Irp);
    ASSERT(IoStackLocation->MajorFunction == IRP_MJ_LOCK_CONTROL);
    
    /* Clear the I/O status block and check what function this is */
    IoStatusBlock.Information = 0;
    
    DPRINT("FsRtlProcessFileLock(%wZ, MinorFunction %x)\n", 
           &IoStackLocation->FileObject->FileName,
           IoStackLocation->MinorFunction);
    
    switch(IoStackLocation->MinorFunction)
    {
        /* A lock */
    case IRP_MN_LOCK:
        
        /* Call the private lock routine */
        FsRtlPrivateLock(FileLock,
                         IoStackLocation->FileObject,
                         &IoStackLocation->
                         Parameters.LockControl.ByteOffset,
                         IoStackLocation->Parameters.LockControl.Length,
                         IoGetRequestorProcess(Irp),
                         IoStackLocation->Parameters.LockControl.Key,
                         IoStackLocation->Flags & SL_FAIL_IMMEDIATELY,
                         IoStackLocation->Flags & SL_EXCLUSIVE_LOCK,
                         &IoStatusBlock,
                         Irp,
                         Context,
                         FALSE);
        return IoStatusBlock.Status;
        
        /* A single unlock */
    case IRP_MN_UNLOCK_SINGLE:
        
        /* Call fast unlock */
        IoStatusBlock.Status =
            FsRtlFastUnlockSingle(FileLock,
                                  IoStackLocation->FileObject,
                                  &IoStackLocation->Parameters.LockControl.
                                  ByteOffset,
                                  IoStackLocation->Parameters.LockControl.
                                  Length,
                                  IoGetRequestorProcess(Irp),
                                  IoStackLocation->Parameters.LockControl.
                                  Key,
                                  Context,
                                  FALSE);
        break;
        
        /* Total unlock */
    case IRP_MN_UNLOCK_ALL:
        
        /* Do a fast unlock */
        IoStatusBlock.Status = FsRtlFastUnlockAll(FileLock,
                                                  IoStackLocation->
                                                  FileObject,
                                                  IoGetRequestorProcess(Irp),
                                                  Context);
        break;
        
        /* Unlock by key */
    case IRP_MN_UNLOCK_ALL_BY_KEY:
        
        /* Do it */
        IoStatusBlock.Status =
            FsRtlFastUnlockAllByKey(FileLock,
                                    IoStackLocation->FileObject,
                                    IoGetRequestorProcess(Irp),
                                    IoStackLocation->Parameters.
                                    LockControl.Key,
                                    Context);
        break;
        
        /* Invalid request */
    default:
        
        /* Complete it */
        FsRtlCompleteRequest(Irp, STATUS_INVALID_DEVICE_REQUEST);
        IoStatusBlock.Status = STATUS_INVALID_DEVICE_REQUEST;
        return STATUS_INVALID_DEVICE_REQUEST;
    }
    
    /* Return the status */
    DPRINT("Lock IRP %p %x\n", Irp, IoStatusBlock.Status);
    FsRtlCompleteLockIrpReal
        (FileLock->CompleteLockIrpRoutine,
         Context,
         Irp,
         IoStatusBlock.Status,
         &Status,
         NULL);
    return IoStatusBlock.Status;
}

Referenced by _Dispatch_type_(), _Requires_lock_held_(), CdCommonLockControl(), Ext2LockControl(), FFSLockControl(), FsRtlFastUnlockSingle(), FsRtlUninitializeFileLock(), RfsdLockControl(), UDFCommonLockControl(), and VfatLockControl().

FsRtlUninitializeFileLock()

VOID NTAPI FsRtlUninitializeFileLock

(

IN PFILE_LOCK

FileLock

)

Definition at line 1278 of file filelock.c.

{
    if (FileLock->LockInformation)
    {
        PIRP Irp;
        PLOCK_INFORMATION InternalInfo = FileLock->LockInformation;
        PCOMBINED_LOCK_ELEMENT Entry;
        PLIST_ENTRY SharedEntry;
        PLOCK_SHARED_RANGE SharedRange;
        // MSDN: this completes any remaining lock IRPs
        for (SharedEntry = InternalInfo->SharedLocks.Flink;
             SharedEntry != &InternalInfo->SharedLocks;)
        {
            SharedRange = CONTAINING_RECORD(SharedEntry, LOCK_SHARED_RANGE, Entry);
            SharedEntry = SharedEntry->Flink;
            RemoveEntryList(&SharedRange->Entry);
            ExFreePoolWithTag(SharedRange, TAG_RANGE);
        }
        while ((Entry = RtlGetElementGenericTable(&InternalInfo->RangeTable, 0)) != NULL)
        {
            RtlDeleteElementGenericTable(&InternalInfo->RangeTable, Entry);
        }
        while ((Irp = IoCsqRemoveNextIrp(&InternalInfo->Csq, NULL)) != NULL)
        {
            FsRtlProcessFileLock(FileLock, Irp, NULL);
        }
        ExFreePoolWithTag(InternalInfo, TAG_FLOCK);
        FileLock->LockInformation = NULL;
    }
}

Referenced by Ext2FreeFcb(), FatCreateFcb(), FatDeleteFcb(), FFSFreeFcb(), free_fcb(), FsRtlFreeFileLock(), RfsdFreeFcb(), RxFinalizeNetFcb(), UDFCleanUpFcbChain(), UDFInitializeFCB(), and vfatDestroyFCB().

LockAcquireQueueLock()

static VOID NTAPI LockAcquireQueueLock ( PIO_CSQ  Csq, PKIRQL  Irql  )

static

Definition at line 194 of file filelock.c.

{
    PLOCK_INFORMATION LockInfo = CONTAINING_RECORD(Csq, LOCK_INFORMATION, Csq);
    KeAcquireSpinLock(&LockInfo->CsqLock, Irql);
}

Referenced by FsRtlPrivateLock().

LockAllocate()

static PVOID NTAPI LockAllocate ( PRTL_GENERIC_TABLE  Table, CLONG  Bytes  )

static

Definition at line 71 of file filelock.c.

{
    PVOID Result;
    Result = ExAllocatePoolWithTag(NonPagedPool, Bytes, TAG_TABLE);
    DPRINT("LockAllocate(%lu) => %p\n", Bytes, Result);
    return Result;
}

Referenced by FsRtlPrivateLock().

LockCompare()

static RTL_GENERIC_COMPARE_RESULTS NTAPI LockCompare ( PRTL_GENERIC_TABLE  Table, PVOID  PtrA, PVOID  PtrB  )

static

Definition at line 86 of file filelock.c.

{
    PCOMBINED_LOCK_ELEMENT A = PtrA, B = PtrB;
    RTL_GENERIC_COMPARE_RESULTS Result;
#if 0
    DPRINT("Starting to compare element %x to element %x\n", PtrA, PtrB);
#endif
    /* Match if we overlap */
    if (((A->Exclusive.FileLock.StartingByte.QuadPart <
          B->Exclusive.FileLock.EndingByte.QuadPart) &&
         (A->Exclusive.FileLock.StartingByte.QuadPart >=
          B->Exclusive.FileLock.StartingByte.QuadPart)) ||
        ((B->Exclusive.FileLock.StartingByte.QuadPart <
          A->Exclusive.FileLock.EndingByte.QuadPart) &&
         (B->Exclusive.FileLock.StartingByte.QuadPart >=
          A->Exclusive.FileLock.StartingByte.QuadPart)))
        return GenericEqual;
    /* Otherwise, key on the starting byte */
    Result =
        (A->Exclusive.FileLock.StartingByte.QuadPart < 
         B->Exclusive.FileLock.StartingByte.QuadPart) ? GenericLessThan :
        (A->Exclusive.FileLock.StartingByte.QuadPart > 
         B->Exclusive.FileLock.StartingByte.QuadPart) ? GenericGreaterThan :
        GenericEqual;
#if 0
    DPRINT("Compare(%x:%x) %x-%x to %x-%x => %d\n",
           A,B,
           A->Exclusive.FileLock.StartingByte.LowPart, 
           A->Exclusive.FileLock.EndingByte.LowPart,
           B->Exclusive.FileLock.StartingByte.LowPart, 
           B->Exclusive.FileLock.EndingByte.LowPart,
           Result);
#endif
    return Result;
}

Referenced by FsRtlFastUnlockSingle(), FsRtlPrivateLock(), and LockPeekNextIrp().

LockCompleteCanceledIrp()

static VOID NTAPI LockCompleteCanceledIrp ( PIO_CSQ  Csq, PIRP  Irp  )

static

Definition at line 208 of file filelock.c.

{
    NTSTATUS Status;
    PLOCK_INFORMATION LockInfo = CONTAINING_RECORD(Csq, LOCK_INFORMATION, Csq);
    DPRINT("Complete cancelled IRP %p Status %x\n", Irp, STATUS_CANCELLED);
    FsRtlCompleteLockIrpReal
        (LockInfo->BelongsTo->CompleteLockIrpRoutine,
         NULL,
         Irp,
         STATUS_CANCELLED,
         &Status,
         NULL);
}

Referenced by FsRtlPrivateLock().

LockFree()

static VOID NTAPI LockFree ( PRTL_GENERIC_TABLE  Table, PVOID  Buffer  )

static

Definition at line 79 of file filelock.c.

{
    DPRINT("LockFree(%p)\n", Buffer);
    ExFreePoolWithTag(Buffer, TAG_TABLE);
}

Referenced by FsRtlPrivateLock().

LockInsertIrpEx()

static NTSTATUS NTAPI LockInsertIrpEx ( PIO_CSQ  Csq, PIRP  Irp, PVOID  InsertContext  )

static

Definition at line 125 of file filelock.c.

{
    PLOCK_INFORMATION LockInfo = CONTAINING_RECORD(Csq, LOCK_INFORMATION, Csq);
    InsertTailList(&LockInfo->CsqList, &Irp->Tail.Overlay.ListEntry);
    return STATUS_SUCCESS;
}

Referenced by FsRtlPrivateLock().

LockPeekNextIrp()

static PIRP NTAPI LockPeekNextIrp ( PIO_CSQ  Csq, PIRP  Irp, PVOID  PeekContext  )

static

Definition at line 139 of file filelock.c.

{
    // Context will be a COMBINED_LOCK_ELEMENT.  We're looking for a 
    // lock that can be acquired, now that the lock matching PeekContext
    // has been removed.
    COMBINED_LOCK_ELEMENT LockElement;
    PCOMBINED_LOCK_ELEMENT WhereUnlock = PeekContext;
    PLOCK_INFORMATION LockInfo = CONTAINING_RECORD(Csq, LOCK_INFORMATION, Csq);
    PLIST_ENTRY Following;
    DPRINT("PeekNextIrp(IRP %p, Context %p)\n", Irp, PeekContext);
    if (!Irp)
    {
        Following = LockInfo->CsqList.Flink;
    }
    else
        Following = Irp->Tail.Overlay.ListEntry.Flink;
    
    DPRINT("ListEntry %p Head %p\n", Following, &LockInfo->CsqList);
    for (;
         Following != &LockInfo->CsqList;
         Following = Following->Flink)
    {
        PIO_STACK_LOCATION IoStack;
        BOOLEAN Matching;
        Irp = CONTAINING_RECORD(Following, IRP, Tail.Overlay.ListEntry);
        DPRINT("Irp %p\n", Irp);
        IoStack = IoGetCurrentIrpStackLocation(Irp);
        LockElement.Exclusive.FileLock.StartingByte = 
            IoStack->Parameters.LockControl.ByteOffset;
        LockElement.Exclusive.FileLock.EndingByte.QuadPart = 
            LockElement.Exclusive.FileLock.StartingByte.QuadPart + 
            IoStack->Parameters.LockControl.Length->QuadPart;
        /* If a context was specified, it's a range to check to unlock */
        if (WhereUnlock)
        {
            Matching = LockCompare
                (&LockInfo->RangeTable, &LockElement, WhereUnlock) != GenericEqual;
        }
        /* Else get any completable IRP */
        else
        {
            Matching = FALSE;
        }
        if (!Matching)
        {
            // This IRP is fine...
            DPRINT("Returning the IRP %p\n", Irp);
            return Irp;
        }
    }
    DPRINT("Return NULL\n");
    return NULL;
}

Referenced by FsRtlPrivateLock().

LockReleaseQueueLock()

static VOID NTAPI LockReleaseQueueLock ( PIO_CSQ  Csq, KIRQL  Irql  )

static

Definition at line 201 of file filelock.c.

{
    PLOCK_INFORMATION LockInfo = CONTAINING_RECORD(Csq, LOCK_INFORMATION, Csq);
    KeReleaseSpinLock(&LockInfo->CsqLock, Irql);
}

Referenced by FsRtlPrivateLock().

LockRemoveIrp()

static VOID NTAPI LockRemoveIrp ( PIO_CSQ  Csq, PIRP  Irp  )

static

Definition at line 134 of file filelock.c.

{
    RemoveEntryList(&Irp->Tail.Overlay.ListEntry);
}

Referenced by FsRtlPrivateLock().

Variable Documentation

FsRtlFileLockLookasideList

PAGED_LOOKASIDE_LIST FsRtlFileLockLookasideList

Definition at line 17 of file filelock.c.

Referenced by FsRtlAllocateFileLock(), FsRtlFreeFileLock(), and FsRtlInitSystem().